PR tree-optimization/85699
[official-gcc.git] / gcc / ada / sem_ch3.adb
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1 ------------------------------------------------------------------------------
2 -- --
3 -- GNAT COMPILER COMPONENTS --
4 -- --
5 -- S E M _ C H 3 --
6 -- --
7 -- B o d y --
8 -- --
9 -- Copyright (C) 1992-2018, Free Software Foundation, Inc. --
10 -- --
11 -- GNAT is free software; you can redistribute it and/or modify it under --
12 -- terms of the GNU General Public License as published by the Free Soft- --
13 -- ware Foundation; either version 3, or (at your option) any later ver- --
14 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
15 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
16 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
17 -- for more details. You should have received a copy of the GNU General --
18 -- Public License distributed with GNAT; see file COPYING3. If not, go to --
19 -- http://www.gnu.org/licenses for a complete copy of the license. --
20 -- --
21 -- GNAT was originally developed by the GNAT team at New York University. --
22 -- Extensive contributions were provided by Ada Core Technologies Inc. --
23 -- --
24 ------------------------------------------------------------------------------
26 with Aspects; use Aspects;
27 with Atree; use Atree;
28 with Checks; use Checks;
29 with Contracts; use Contracts;
30 with Debug; use Debug;
31 with Elists; use Elists;
32 with Einfo; use Einfo;
33 with Errout; use Errout;
34 with Eval_Fat; use Eval_Fat;
35 with Exp_Ch3; use Exp_Ch3;
36 with Exp_Ch9; use Exp_Ch9;
37 with Exp_Disp; use Exp_Disp;
38 with Exp_Dist; use Exp_Dist;
39 with Exp_Tss; use Exp_Tss;
40 with Exp_Util; use Exp_Util;
41 with Freeze; use Freeze;
42 with Ghost; use Ghost;
43 with Itypes; use Itypes;
44 with Layout; use Layout;
45 with Lib; use Lib;
46 with Lib.Xref; use Lib.Xref;
47 with Namet; use Namet;
48 with Nmake; use Nmake;
49 with Opt; use Opt;
50 with Restrict; use Restrict;
51 with Rident; use Rident;
52 with Rtsfind; use Rtsfind;
53 with Sem; use Sem;
54 with Sem_Aux; use Sem_Aux;
55 with Sem_Case; use Sem_Case;
56 with Sem_Cat; use Sem_Cat;
57 with Sem_Ch6; use Sem_Ch6;
58 with Sem_Ch7; use Sem_Ch7;
59 with Sem_Ch8; use Sem_Ch8;
60 with Sem_Ch13; use Sem_Ch13;
61 with Sem_Dim; use Sem_Dim;
62 with Sem_Disp; use Sem_Disp;
63 with Sem_Dist; use Sem_Dist;
64 with Sem_Elab; use Sem_Elab;
65 with Sem_Elim; use Sem_Elim;
66 with Sem_Eval; use Sem_Eval;
67 with Sem_Mech; use Sem_Mech;
68 with Sem_Res; use Sem_Res;
69 with Sem_Smem; use Sem_Smem;
70 with Sem_Type; use Sem_Type;
71 with Sem_Util; use Sem_Util;
72 with Sem_Warn; use Sem_Warn;
73 with Stand; use Stand;
74 with Sinfo; use Sinfo;
75 with Sinput; use Sinput;
76 with Snames; use Snames;
77 with Targparm; use Targparm;
78 with Tbuild; use Tbuild;
79 with Ttypes; use Ttypes;
80 with Uintp; use Uintp;
81 with Urealp; use Urealp;
83 package body Sem_Ch3 is
85 -----------------------
86 -- Local Subprograms --
87 -----------------------
89 procedure Add_Interface_Tag_Components (N : Node_Id; Typ : Entity_Id);
90 -- Ada 2005 (AI-251): Add the tag components corresponding to all the
91 -- abstract interface types implemented by a record type or a derived
92 -- record type.
94 procedure Build_Derived_Type
95 (N : Node_Id;
96 Parent_Type : Entity_Id;
97 Derived_Type : Entity_Id;
98 Is_Completion : Boolean;
99 Derive_Subps : Boolean := True);
100 -- Create and decorate a Derived_Type given the Parent_Type entity. N is
101 -- the N_Full_Type_Declaration node containing the derived type definition.
102 -- Parent_Type is the entity for the parent type in the derived type
103 -- definition and Derived_Type the actual derived type. Is_Completion must
104 -- be set to False if Derived_Type is the N_Defining_Identifier node in N
105 -- (i.e. Derived_Type = Defining_Identifier (N)). In this case N is not the
106 -- completion of a private type declaration. If Is_Completion is set to
107 -- True, N is the completion of a private type declaration and Derived_Type
108 -- is different from the defining identifier inside N (i.e. Derived_Type /=
109 -- Defining_Identifier (N)). Derive_Subps indicates whether the parent
110 -- subprograms should be derived. The only case where this parameter is
111 -- False is when Build_Derived_Type is recursively called to process an
112 -- implicit derived full type for a type derived from a private type (in
113 -- that case the subprograms must only be derived for the private view of
114 -- the type).
116 -- ??? These flags need a bit of re-examination and re-documentation:
117 -- ??? are they both necessary (both seem related to the recursion)?
119 procedure Build_Derived_Access_Type
120 (N : Node_Id;
121 Parent_Type : Entity_Id;
122 Derived_Type : Entity_Id);
123 -- Subsidiary procedure to Build_Derived_Type. For a derived access type,
124 -- create an implicit base if the parent type is constrained or if the
125 -- subtype indication has a constraint.
127 procedure Build_Derived_Array_Type
128 (N : Node_Id;
129 Parent_Type : Entity_Id;
130 Derived_Type : Entity_Id);
131 -- Subsidiary procedure to Build_Derived_Type. For a derived array type,
132 -- create an implicit base if the parent type is constrained or if the
133 -- subtype indication has a constraint.
135 procedure Build_Derived_Concurrent_Type
136 (N : Node_Id;
137 Parent_Type : Entity_Id;
138 Derived_Type : Entity_Id);
139 -- Subsidiary procedure to Build_Derived_Type. For a derived task or
140 -- protected type, inherit entries and protected subprograms, check
141 -- legality of discriminant constraints if any.
143 procedure Build_Derived_Enumeration_Type
144 (N : Node_Id;
145 Parent_Type : Entity_Id;
146 Derived_Type : Entity_Id);
147 -- Subsidiary procedure to Build_Derived_Type. For a derived enumeration
148 -- type, we must create a new list of literals. Types derived from
149 -- Character and [Wide_]Wide_Character are special-cased.
151 procedure Build_Derived_Numeric_Type
152 (N : Node_Id;
153 Parent_Type : Entity_Id;
154 Derived_Type : Entity_Id);
155 -- Subsidiary procedure to Build_Derived_Type. For numeric types, create
156 -- an anonymous base type, and propagate constraint to subtype if needed.
158 procedure Build_Derived_Private_Type
159 (N : Node_Id;
160 Parent_Type : Entity_Id;
161 Derived_Type : Entity_Id;
162 Is_Completion : Boolean;
163 Derive_Subps : Boolean := True);
164 -- Subsidiary procedure to Build_Derived_Type. This procedure is complex
165 -- because the parent may or may not have a completion, and the derivation
166 -- may itself be a completion.
168 procedure Build_Derived_Record_Type
169 (N : Node_Id;
170 Parent_Type : Entity_Id;
171 Derived_Type : Entity_Id;
172 Derive_Subps : Boolean := True);
173 -- Subsidiary procedure used for tagged and untagged record types
174 -- by Build_Derived_Type and Analyze_Private_Extension_Declaration.
175 -- All parameters are as in Build_Derived_Type except that N, in
176 -- addition to being an N_Full_Type_Declaration node, can also be an
177 -- N_Private_Extension_Declaration node. See the definition of this routine
178 -- for much more info. Derive_Subps indicates whether subprograms should be
179 -- derived from the parent type. The only case where Derive_Subps is False
180 -- is for an implicit derived full type for a type derived from a private
181 -- type (see Build_Derived_Type).
183 procedure Build_Discriminal (Discrim : Entity_Id);
184 -- Create the discriminal corresponding to discriminant Discrim, that is
185 -- the parameter corresponding to Discrim to be used in initialization
186 -- procedures for the type where Discrim is a discriminant. Discriminals
187 -- are not used during semantic analysis, and are not fully defined
188 -- entities until expansion. Thus they are not given a scope until
189 -- initialization procedures are built.
191 function Build_Discriminant_Constraints
192 (T : Entity_Id;
193 Def : Node_Id;
194 Derived_Def : Boolean := False) return Elist_Id;
195 -- Validate discriminant constraints and return the list of the constraints
196 -- in order of discriminant declarations, where T is the discriminated
197 -- unconstrained type. Def is the N_Subtype_Indication node where the
198 -- discriminants constraints for T are specified. Derived_Def is True
199 -- when building the discriminant constraints in a derived type definition
200 -- of the form "type D (...) is new T (xxx)". In this case T is the parent
201 -- type and Def is the constraint "(xxx)" on T and this routine sets the
202 -- Corresponding_Discriminant field of the discriminants in the derived
203 -- type D to point to the corresponding discriminants in the parent type T.
205 procedure Build_Discriminated_Subtype
206 (T : Entity_Id;
207 Def_Id : Entity_Id;
208 Elist : Elist_Id;
209 Related_Nod : Node_Id;
210 For_Access : Boolean := False);
211 -- Subsidiary procedure to Constrain_Discriminated_Type and to
212 -- Process_Incomplete_Dependents. Given
214 -- T (a possibly discriminated base type)
215 -- Def_Id (a very partially built subtype for T),
217 -- the call completes Def_Id to be the appropriate E_*_Subtype.
219 -- The Elist is the list of discriminant constraints if any (it is set
220 -- to No_Elist if T is not a discriminated type, and to an empty list if
221 -- T has discriminants but there are no discriminant constraints). The
222 -- Related_Nod is the same as Decl_Node in Create_Constrained_Components.
223 -- The For_Access says whether or not this subtype is really constraining
224 -- an access type. That is its sole purpose is the designated type of an
225 -- access type -- in which case a Private_Subtype Is_For_Access_Subtype
226 -- is built to avoid freezing T when the access subtype is frozen.
228 function Build_Scalar_Bound
229 (Bound : Node_Id;
230 Par_T : Entity_Id;
231 Der_T : Entity_Id) return Node_Id;
232 -- The bounds of a derived scalar type are conversions of the bounds of
233 -- the parent type. Optimize the representation if the bounds are literals.
234 -- Needs a more complete spec--what are the parameters exactly, and what
235 -- exactly is the returned value, and how is Bound affected???
237 procedure Build_Underlying_Full_View
238 (N : Node_Id;
239 Typ : Entity_Id;
240 Par : Entity_Id);
241 -- If the completion of a private type is itself derived from a private
242 -- type, or if the full view of a private subtype is itself private, the
243 -- back-end has no way to compute the actual size of this type. We build
244 -- an internal subtype declaration of the proper parent type to convey
245 -- this information. This extra mechanism is needed because a full
246 -- view cannot itself have a full view (it would get clobbered during
247 -- view exchanges).
249 procedure Check_Access_Discriminant_Requires_Limited
250 (D : Node_Id;
251 Loc : Node_Id);
252 -- Check the restriction that the type to which an access discriminant
253 -- belongs must be a concurrent type or a descendant of a type with
254 -- the reserved word 'limited' in its declaration.
256 procedure Check_Anonymous_Access_Components
257 (Typ_Decl : Node_Id;
258 Typ : Entity_Id;
259 Prev : Entity_Id;
260 Comp_List : Node_Id);
261 -- Ada 2005 AI-382: an access component in a record definition can refer to
262 -- the enclosing record, in which case it denotes the type itself, and not
263 -- the current instance of the type. We create an anonymous access type for
264 -- the component, and flag it as an access to a component, so accessibility
265 -- checks are properly performed on it. The declaration of the access type
266 -- is placed ahead of that of the record to prevent order-of-elaboration
267 -- circularity issues in Gigi. We create an incomplete type for the record
268 -- declaration, which is the designated type of the anonymous access.
270 procedure Check_Delta_Expression (E : Node_Id);
271 -- Check that the expression represented by E is suitable for use as a
272 -- delta expression, i.e. it is of real type and is static.
274 procedure Check_Digits_Expression (E : Node_Id);
275 -- Check that the expression represented by E is suitable for use as a
276 -- digits expression, i.e. it is of integer type, positive and static.
278 procedure Check_Initialization (T : Entity_Id; Exp : Node_Id);
279 -- Validate the initialization of an object declaration. T is the required
280 -- type, and Exp is the initialization expression.
282 procedure Check_Interfaces (N : Node_Id; Def : Node_Id);
283 -- Check ARM rules 3.9.4 (15/2), 9.1 (9.d/2) and 9.4 (11.d/2)
285 procedure Check_Or_Process_Discriminants
286 (N : Node_Id;
287 T : Entity_Id;
288 Prev : Entity_Id := Empty);
289 -- If N is the full declaration of the completion T of an incomplete or
290 -- private type, check its discriminants (which are already known to be
291 -- conformant with those of the partial view, see Find_Type_Name),
292 -- otherwise process them. Prev is the entity of the partial declaration,
293 -- if any.
295 procedure Check_Real_Bound (Bound : Node_Id);
296 -- Check given bound for being of real type and static. If not, post an
297 -- appropriate message, and rewrite the bound with the real literal zero.
299 procedure Constant_Redeclaration
300 (Id : Entity_Id;
301 N : Node_Id;
302 T : out Entity_Id);
303 -- Various checks on legality of full declaration of deferred constant.
304 -- Id is the entity for the redeclaration, N is the N_Object_Declaration,
305 -- node. The caller has not yet set any attributes of this entity.
307 function Contain_Interface
308 (Iface : Entity_Id;
309 Ifaces : Elist_Id) return Boolean;
310 -- Ada 2005: Determine whether Iface is present in the list Ifaces
312 procedure Convert_Scalar_Bounds
313 (N : Node_Id;
314 Parent_Type : Entity_Id;
315 Derived_Type : Entity_Id;
316 Loc : Source_Ptr);
317 -- For derived scalar types, convert the bounds in the type definition to
318 -- the derived type, and complete their analysis. Given a constraint of the
319 -- form ".. new T range Lo .. Hi", Lo and Hi are analyzed and resolved with
320 -- T'Base, the parent_type. The bounds of the derived type (the anonymous
321 -- base) are copies of Lo and Hi. Finally, the bounds of the derived
322 -- subtype are conversions of those bounds to the derived_type, so that
323 -- their typing is consistent.
325 procedure Copy_Array_Base_Type_Attributes (T1, T2 : Entity_Id);
326 -- Copies attributes from array base type T2 to array base type T1. Copies
327 -- only attributes that apply to base types, but not subtypes.
329 procedure Copy_Array_Subtype_Attributes (T1, T2 : Entity_Id);
330 -- Copies attributes from array subtype T2 to array subtype T1. Copies
331 -- attributes that apply to both subtypes and base types.
333 procedure Create_Constrained_Components
334 (Subt : Entity_Id;
335 Decl_Node : Node_Id;
336 Typ : Entity_Id;
337 Constraints : Elist_Id);
338 -- Build the list of entities for a constrained discriminated record
339 -- subtype. If a component depends on a discriminant, replace its subtype
340 -- using the discriminant values in the discriminant constraint. Subt
341 -- is the defining identifier for the subtype whose list of constrained
342 -- entities we will create. Decl_Node is the type declaration node where
343 -- we will attach all the itypes created. Typ is the base discriminated
344 -- type for the subtype Subt. Constraints is the list of discriminant
345 -- constraints for Typ.
347 function Constrain_Component_Type
348 (Comp : Entity_Id;
349 Constrained_Typ : Entity_Id;
350 Related_Node : Node_Id;
351 Typ : Entity_Id;
352 Constraints : Elist_Id) return Entity_Id;
353 -- Given a discriminated base type Typ, a list of discriminant constraints,
354 -- Constraints, for Typ and a component Comp of Typ, create and return the
355 -- type corresponding to Etype (Comp) where all discriminant references
356 -- are replaced with the corresponding constraint. If Etype (Comp) contains
357 -- no discriminant references then it is returned as-is. Constrained_Typ
358 -- is the final constrained subtype to which the constrained component
359 -- belongs. Related_Node is the node where we attach all created itypes.
361 procedure Constrain_Access
362 (Def_Id : in out Entity_Id;
363 S : Node_Id;
364 Related_Nod : Node_Id);
365 -- Apply a list of constraints to an access type. If Def_Id is empty, it is
366 -- an anonymous type created for a subtype indication. In that case it is
367 -- created in the procedure and attached to Related_Nod.
369 procedure Constrain_Array
370 (Def_Id : in out Entity_Id;
371 SI : Node_Id;
372 Related_Nod : Node_Id;
373 Related_Id : Entity_Id;
374 Suffix : Character);
375 -- Apply a list of index constraints to an unconstrained array type. The
376 -- first parameter is the entity for the resulting subtype. A value of
377 -- Empty for Def_Id indicates that an implicit type must be created, but
378 -- creation is delayed (and must be done by this procedure) because other
379 -- subsidiary implicit types must be created first (which is why Def_Id
380 -- is an in/out parameter). The second parameter is a subtype indication
381 -- node for the constrained array to be created (e.g. something of the
382 -- form string (1 .. 10)). Related_Nod gives the place where this type
383 -- has to be inserted in the tree. The Related_Id and Suffix parameters
384 -- are used to build the associated Implicit type name.
386 procedure Constrain_Concurrent
387 (Def_Id : in out Entity_Id;
388 SI : Node_Id;
389 Related_Nod : Node_Id;
390 Related_Id : Entity_Id;
391 Suffix : Character);
392 -- Apply list of discriminant constraints to an unconstrained concurrent
393 -- type.
395 -- SI is the N_Subtype_Indication node containing the constraint and
396 -- the unconstrained type to constrain.
398 -- Def_Id is the entity for the resulting constrained subtype. A value
399 -- of Empty for Def_Id indicates that an implicit type must be created,
400 -- but creation is delayed (and must be done by this procedure) because
401 -- other subsidiary implicit types must be created first (which is why
402 -- Def_Id is an in/out parameter).
404 -- Related_Nod gives the place where this type has to be inserted
405 -- in the tree.
407 -- The last two arguments are used to create its external name if needed.
409 function Constrain_Corresponding_Record
410 (Prot_Subt : Entity_Id;
411 Corr_Rec : Entity_Id;
412 Related_Nod : Node_Id) return Entity_Id;
413 -- When constraining a protected type or task type with discriminants,
414 -- constrain the corresponding record with the same discriminant values.
416 procedure Constrain_Decimal (Def_Id : Node_Id; S : Node_Id);
417 -- Constrain a decimal fixed point type with a digits constraint and/or a
418 -- range constraint, and build E_Decimal_Fixed_Point_Subtype entity.
420 procedure Constrain_Discriminated_Type
421 (Def_Id : Entity_Id;
422 S : Node_Id;
423 Related_Nod : Node_Id;
424 For_Access : Boolean := False);
425 -- Process discriminant constraints of composite type. Verify that values
426 -- have been provided for all discriminants, that the original type is
427 -- unconstrained, and that the types of the supplied expressions match
428 -- the discriminant types. The first three parameters are like in routine
429 -- Constrain_Concurrent. See Build_Discriminated_Subtype for an explanation
430 -- of For_Access.
432 procedure Constrain_Enumeration (Def_Id : Node_Id; S : Node_Id);
433 -- Constrain an enumeration type with a range constraint. This is identical
434 -- to Constrain_Integer, but for the Ekind of the resulting subtype.
436 procedure Constrain_Float (Def_Id : Node_Id; S : Node_Id);
437 -- Constrain a floating point type with either a digits constraint
438 -- and/or a range constraint, building a E_Floating_Point_Subtype.
440 procedure Constrain_Index
441 (Index : Node_Id;
442 S : Node_Id;
443 Related_Nod : Node_Id;
444 Related_Id : Entity_Id;
445 Suffix : Character;
446 Suffix_Index : Nat);
447 -- Process an index constraint S in a constrained array declaration. The
448 -- constraint can be a subtype name, or a range with or without an explicit
449 -- subtype mark. The index is the corresponding index of the unconstrained
450 -- array. The Related_Id and Suffix parameters are used to build the
451 -- associated Implicit type name.
453 procedure Constrain_Integer (Def_Id : Node_Id; S : Node_Id);
454 -- Build subtype of a signed or modular integer type
456 procedure Constrain_Ordinary_Fixed (Def_Id : Node_Id; S : Node_Id);
457 -- Constrain an ordinary fixed point type with a range constraint, and
458 -- build an E_Ordinary_Fixed_Point_Subtype entity.
460 procedure Copy_And_Swap (Priv, Full : Entity_Id);
461 -- Copy the Priv entity into the entity of its full declaration then swap
462 -- the two entities in such a manner that the former private type is now
463 -- seen as a full type.
465 procedure Decimal_Fixed_Point_Type_Declaration
466 (T : Entity_Id;
467 Def : Node_Id);
468 -- Create a new decimal fixed point type, and apply the constraint to
469 -- obtain a subtype of this new type.
471 procedure Complete_Private_Subtype
472 (Priv : Entity_Id;
473 Full : Entity_Id;
474 Full_Base : Entity_Id;
475 Related_Nod : Node_Id);
476 -- Complete the implicit full view of a private subtype by setting the
477 -- appropriate semantic fields. If the full view of the parent is a record
478 -- type, build constrained components of subtype.
480 procedure Derive_Progenitor_Subprograms
481 (Parent_Type : Entity_Id;
482 Tagged_Type : Entity_Id);
483 -- Ada 2005 (AI-251): To complete type derivation, collect the primitive
484 -- operations of progenitors of Tagged_Type, and replace the subsidiary
485 -- subtypes with Tagged_Type, to build the specs of the inherited interface
486 -- primitives. The derived primitives are aliased to those of the
487 -- interface. This routine takes care also of transferring to the full view
488 -- subprograms associated with the partial view of Tagged_Type that cover
489 -- interface primitives.
491 procedure Derived_Standard_Character
492 (N : Node_Id;
493 Parent_Type : Entity_Id;
494 Derived_Type : Entity_Id);
495 -- Subsidiary procedure to Build_Derived_Enumeration_Type which handles
496 -- derivations from types Standard.Character and Standard.Wide_Character.
498 procedure Derived_Type_Declaration
499 (T : Entity_Id;
500 N : Node_Id;
501 Is_Completion : Boolean);
502 -- Process a derived type declaration. Build_Derived_Type is invoked
503 -- to process the actual derived type definition. Parameters N and
504 -- Is_Completion have the same meaning as in Build_Derived_Type.
505 -- T is the N_Defining_Identifier for the entity defined in the
506 -- N_Full_Type_Declaration node N, that is T is the derived type.
508 procedure Enumeration_Type_Declaration (T : Entity_Id; Def : Node_Id);
509 -- Insert each literal in symbol table, as an overloadable identifier. Each
510 -- enumeration type is mapped into a sequence of integers, and each literal
511 -- is defined as a constant with integer value. If any of the literals are
512 -- character literals, the type is a character type, which means that
513 -- strings are legal aggregates for arrays of components of the type.
515 function Expand_To_Stored_Constraint
516 (Typ : Entity_Id;
517 Constraint : Elist_Id) return Elist_Id;
518 -- Given a constraint (i.e. a list of expressions) on the discriminants of
519 -- Typ, expand it into a constraint on the stored discriminants and return
520 -- the new list of expressions constraining the stored discriminants.
522 function Find_Type_Of_Object
523 (Obj_Def : Node_Id;
524 Related_Nod : Node_Id) return Entity_Id;
525 -- Get type entity for object referenced by Obj_Def, attaching the implicit
526 -- types generated to Related_Nod.
528 procedure Floating_Point_Type_Declaration (T : Entity_Id; Def : Node_Id);
529 -- Create a new float and apply the constraint to obtain subtype of it
531 function Has_Range_Constraint (N : Node_Id) return Boolean;
532 -- Given an N_Subtype_Indication node N, return True if a range constraint
533 -- is present, either directly, or as part of a digits or delta constraint.
534 -- In addition, a digits constraint in the decimal case returns True, since
535 -- it establishes a default range if no explicit range is present.
537 function Inherit_Components
538 (N : Node_Id;
539 Parent_Base : Entity_Id;
540 Derived_Base : Entity_Id;
541 Is_Tagged : Boolean;
542 Inherit_Discr : Boolean;
543 Discs : Elist_Id) return Elist_Id;
544 -- Called from Build_Derived_Record_Type to inherit the components of
545 -- Parent_Base (a base type) into the Derived_Base (the derived base type).
546 -- For more information on derived types and component inheritance please
547 -- consult the comment above the body of Build_Derived_Record_Type.
549 -- N is the original derived type declaration
551 -- Is_Tagged is set if we are dealing with tagged types
553 -- If Inherit_Discr is set, Derived_Base inherits its discriminants from
554 -- Parent_Base, otherwise no discriminants are inherited.
556 -- Discs gives the list of constraints that apply to Parent_Base in the
557 -- derived type declaration. If Discs is set to No_Elist, then we have
558 -- the following situation:
560 -- type Parent (D1..Dn : ..) is [tagged] record ...;
561 -- type Derived is new Parent [with ...];
563 -- which gets treated as
565 -- type Derived (D1..Dn : ..) is new Parent (D1,..,Dn) [with ...];
567 -- For untagged types the returned value is an association list. The list
568 -- starts from the association (Parent_Base => Derived_Base), and then it
569 -- contains a sequence of the associations of the form
571 -- (Old_Component => New_Component),
573 -- where Old_Component is the Entity_Id of a component in Parent_Base and
574 -- New_Component is the Entity_Id of the corresponding component in
575 -- Derived_Base. For untagged records, this association list is needed when
576 -- copying the record declaration for the derived base. In the tagged case
577 -- the value returned is irrelevant.
579 procedure Inherit_Predicate_Flags (Subt, Par : Entity_Id);
580 -- Propagate static and dynamic predicate flags from a parent to the
581 -- subtype in a subtype declaration with and without constraints.
583 function Is_EVF_Procedure (Subp : Entity_Id) return Boolean;
584 -- Subsidiary to Check_Abstract_Overriding and Derive_Subprogram.
585 -- Determine whether subprogram Subp is a procedure subject to pragma
586 -- Extensions_Visible with value False and has at least one controlling
587 -- parameter of mode OUT.
589 function Is_Valid_Constraint_Kind
590 (T_Kind : Type_Kind;
591 Constraint_Kind : Node_Kind) return Boolean;
592 -- Returns True if it is legal to apply the given kind of constraint to the
593 -- given kind of type (index constraint to an array type, for example).
595 procedure Modular_Type_Declaration (T : Entity_Id; Def : Node_Id);
596 -- Create new modular type. Verify that modulus is in bounds
598 procedure New_Concatenation_Op (Typ : Entity_Id);
599 -- Create an abbreviated declaration for an operator in order to
600 -- materialize concatenation on array types.
602 procedure Ordinary_Fixed_Point_Type_Declaration
603 (T : Entity_Id;
604 Def : Node_Id);
605 -- Create a new ordinary fixed point type, and apply the constraint to
606 -- obtain subtype of it.
608 procedure Prepare_Private_Subtype_Completion
609 (Id : Entity_Id;
610 Related_Nod : Node_Id);
611 -- Id is a subtype of some private type. Creates the full declaration
612 -- associated with Id whenever possible, i.e. when the full declaration
613 -- of the base type is already known. Records each subtype into
614 -- Private_Dependents of the base type.
616 procedure Process_Incomplete_Dependents
617 (N : Node_Id;
618 Full_T : Entity_Id;
619 Inc_T : Entity_Id);
620 -- Process all entities that depend on an incomplete type. There include
621 -- subtypes, subprogram types that mention the incomplete type in their
622 -- profiles, and subprogram with access parameters that designate the
623 -- incomplete type.
625 -- Inc_T is the defining identifier of an incomplete type declaration, its
626 -- Ekind is E_Incomplete_Type.
628 -- N is the corresponding N_Full_Type_Declaration for Inc_T.
630 -- Full_T is N's defining identifier.
632 -- Subtypes of incomplete types with discriminants are completed when the
633 -- parent type is. This is simpler than private subtypes, because they can
634 -- only appear in the same scope, and there is no need to exchange views.
635 -- Similarly, access_to_subprogram types may have a parameter or a return
636 -- type that is an incomplete type, and that must be replaced with the
637 -- full type.
639 -- If the full type is tagged, subprogram with access parameters that
640 -- designated the incomplete may be primitive operations of the full type,
641 -- and have to be processed accordingly.
643 procedure Process_Real_Range_Specification (Def : Node_Id);
644 -- Given the type definition for a real type, this procedure processes and
645 -- checks the real range specification of this type definition if one is
646 -- present. If errors are found, error messages are posted, and the
647 -- Real_Range_Specification of Def is reset to Empty.
649 procedure Record_Type_Declaration
650 (T : Entity_Id;
651 N : Node_Id;
652 Prev : Entity_Id);
653 -- Process a record type declaration (for both untagged and tagged
654 -- records). Parameters T and N are exactly like in procedure
655 -- Derived_Type_Declaration, except that no flag Is_Completion is needed
656 -- for this routine. If this is the completion of an incomplete type
657 -- declaration, Prev is the entity of the incomplete declaration, used for
658 -- cross-referencing. Otherwise Prev = T.
660 procedure Record_Type_Definition (Def : Node_Id; Prev_T : Entity_Id);
661 -- This routine is used to process the actual record type definition (both
662 -- for untagged and tagged records). Def is a record type definition node.
663 -- This procedure analyzes the components in this record type definition.
664 -- Prev_T is the entity for the enclosing record type. It is provided so
665 -- that its Has_Task flag can be set if any of the component have Has_Task
666 -- set. If the declaration is the completion of an incomplete type
667 -- declaration, Prev_T is the original incomplete type, whose full view is
668 -- the record type.
670 procedure Replace_Components (Typ : Entity_Id; Decl : Node_Id);
671 -- Subsidiary to Build_Derived_Record_Type. For untagged records, we
672 -- build a copy of the declaration tree of the parent, and we create
673 -- independently the list of components for the derived type. Semantic
674 -- information uses the component entities, but record representation
675 -- clauses are validated on the declaration tree. This procedure replaces
676 -- discriminants and components in the declaration with those that have
677 -- been created by Inherit_Components.
679 procedure Set_Fixed_Range
680 (E : Entity_Id;
681 Loc : Source_Ptr;
682 Lo : Ureal;
683 Hi : Ureal);
684 -- Build a range node with the given bounds and set it as the Scalar_Range
685 -- of the given fixed-point type entity. Loc is the source location used
686 -- for the constructed range. See body for further details.
688 procedure Set_Scalar_Range_For_Subtype
689 (Def_Id : Entity_Id;
690 R : Node_Id;
691 Subt : Entity_Id);
692 -- This routine is used to set the scalar range field for a subtype given
693 -- Def_Id, the entity for the subtype, and R, the range expression for the
694 -- scalar range. Subt provides the parent subtype to be used to analyze,
695 -- resolve, and check the given range.
697 procedure Set_Default_SSO (T : Entity_Id);
698 -- T is the entity for an array or record being declared. This procedure
699 -- sets the flags SSO_Set_Low_By_Default/SSO_Set_High_By_Default according
700 -- to the setting of Opt.Default_SSO.
702 procedure Signed_Integer_Type_Declaration (T : Entity_Id; Def : Node_Id);
703 -- Create a new signed integer entity, and apply the constraint to obtain
704 -- the required first named subtype of this type.
706 procedure Set_Stored_Constraint_From_Discriminant_Constraint
707 (E : Entity_Id);
708 -- E is some record type. This routine computes E's Stored_Constraint
709 -- from its Discriminant_Constraint.
711 procedure Diagnose_Interface (N : Node_Id; E : Entity_Id);
712 -- Check that an entity in a list of progenitors is an interface,
713 -- emit error otherwise.
715 -----------------------
716 -- Access_Definition --
717 -----------------------
719 function Access_Definition
720 (Related_Nod : Node_Id;
721 N : Node_Id) return Entity_Id
723 Anon_Type : Entity_Id;
724 Anon_Scope : Entity_Id;
725 Desig_Type : Entity_Id;
726 Enclosing_Prot_Type : Entity_Id := Empty;
728 begin
729 Check_SPARK_05_Restriction ("access type is not allowed", N);
731 if Is_Entry (Current_Scope)
732 and then Is_Task_Type (Etype (Scope (Current_Scope)))
733 then
734 Error_Msg_N ("task entries cannot have access parameters", N);
735 return Empty;
736 end if;
738 -- Ada 2005: For an object declaration the corresponding anonymous
739 -- type is declared in the current scope.
741 -- If the access definition is the return type of another access to
742 -- function, scope is the current one, because it is the one of the
743 -- current type declaration, except for the pathological case below.
745 if Nkind_In (Related_Nod, N_Object_Declaration,
746 N_Access_Function_Definition)
747 then
748 Anon_Scope := Current_Scope;
750 -- A pathological case: function returning access functions that
751 -- return access functions, etc. Each anonymous access type created
752 -- is in the enclosing scope of the outermost function.
754 declare
755 Par : Node_Id;
757 begin
758 Par := Related_Nod;
759 while Nkind_In (Par, N_Access_Function_Definition,
760 N_Access_Definition)
761 loop
762 Par := Parent (Par);
763 end loop;
765 if Nkind (Par) = N_Function_Specification then
766 Anon_Scope := Scope (Defining_Entity (Par));
767 end if;
768 end;
770 -- For the anonymous function result case, retrieve the scope of the
771 -- function specification's associated entity rather than using the
772 -- current scope. The current scope will be the function itself if the
773 -- formal part is currently being analyzed, but will be the parent scope
774 -- in the case of a parameterless function, and we always want to use
775 -- the function's parent scope. Finally, if the function is a child
776 -- unit, we must traverse the tree to retrieve the proper entity.
778 elsif Nkind (Related_Nod) = N_Function_Specification
779 and then Nkind (Parent (N)) /= N_Parameter_Specification
780 then
781 -- If the current scope is a protected type, the anonymous access
782 -- is associated with one of the protected operations, and must
783 -- be available in the scope that encloses the protected declaration.
784 -- Otherwise the type is in the scope enclosing the subprogram.
786 -- If the function has formals, The return type of a subprogram
787 -- declaration is analyzed in the scope of the subprogram (see
788 -- Process_Formals) and thus the protected type, if present, is
789 -- the scope of the current function scope.
791 if Ekind (Current_Scope) = E_Protected_Type then
792 Enclosing_Prot_Type := Current_Scope;
794 elsif Ekind (Current_Scope) = E_Function
795 and then Ekind (Scope (Current_Scope)) = E_Protected_Type
796 then
797 Enclosing_Prot_Type := Scope (Current_Scope);
798 end if;
800 if Present (Enclosing_Prot_Type) then
801 Anon_Scope := Scope (Enclosing_Prot_Type);
803 else
804 Anon_Scope := Scope (Defining_Entity (Related_Nod));
805 end if;
807 -- For an access type definition, if the current scope is a child
808 -- unit it is the scope of the type.
810 elsif Is_Compilation_Unit (Current_Scope) then
811 Anon_Scope := Current_Scope;
813 -- For access formals, access components, and access discriminants, the
814 -- scope is that of the enclosing declaration,
816 else
817 Anon_Scope := Scope (Current_Scope);
818 end if;
820 Anon_Type :=
821 Create_Itype
822 (E_Anonymous_Access_Type, Related_Nod, Scope_Id => Anon_Scope);
824 if All_Present (N)
825 and then Ada_Version >= Ada_2005
826 then
827 Error_Msg_N ("ALL is not permitted for anonymous access types", N);
828 end if;
830 -- Ada 2005 (AI-254): In case of anonymous access to subprograms call
831 -- the corresponding semantic routine
833 if Present (Access_To_Subprogram_Definition (N)) then
835 -- Compiler runtime units are compiled in Ada 2005 mode when building
836 -- the runtime library but must also be compilable in Ada 95 mode
837 -- (when bootstrapping the compiler).
839 Check_Compiler_Unit ("anonymous access to subprogram", N);
841 Access_Subprogram_Declaration
842 (T_Name => Anon_Type,
843 T_Def => Access_To_Subprogram_Definition (N));
845 if Ekind (Anon_Type) = E_Access_Protected_Subprogram_Type then
846 Set_Ekind
847 (Anon_Type, E_Anonymous_Access_Protected_Subprogram_Type);
848 else
849 Set_Ekind (Anon_Type, E_Anonymous_Access_Subprogram_Type);
850 end if;
852 Set_Can_Use_Internal_Rep
853 (Anon_Type, not Always_Compatible_Rep_On_Target);
855 -- If the anonymous access is associated with a protected operation,
856 -- create a reference to it after the enclosing protected definition
857 -- because the itype will be used in the subsequent bodies.
859 -- If the anonymous access itself is protected, a full type
860 -- declaratiton will be created for it, so that the equivalent
861 -- record type can be constructed. For further details, see
862 -- Replace_Anonymous_Access_To_Protected-Subprogram.
864 if Ekind (Current_Scope) = E_Protected_Type
865 and then not Protected_Present (Access_To_Subprogram_Definition (N))
866 then
867 Build_Itype_Reference (Anon_Type, Parent (Current_Scope));
868 end if;
870 return Anon_Type;
871 end if;
873 Find_Type (Subtype_Mark (N));
874 Desig_Type := Entity (Subtype_Mark (N));
876 Set_Directly_Designated_Type (Anon_Type, Desig_Type);
877 Set_Etype (Anon_Type, Anon_Type);
879 -- Make sure the anonymous access type has size and alignment fields
880 -- set, as required by gigi. This is necessary in the case of the
881 -- Task_Body_Procedure.
883 if not Has_Private_Component (Desig_Type) then
884 Layout_Type (Anon_Type);
885 end if;
887 -- Ada 2005 (AI-231): Ada 2005 semantics for anonymous access differs
888 -- from Ada 95 semantics. In Ada 2005, anonymous access must specify if
889 -- the null value is allowed. In Ada 95 the null value is never allowed.
891 if Ada_Version >= Ada_2005 then
892 Set_Can_Never_Be_Null (Anon_Type, Null_Exclusion_Present (N));
893 else
894 Set_Can_Never_Be_Null (Anon_Type, True);
895 end if;
897 -- The anonymous access type is as public as the discriminated type or
898 -- subprogram that defines it. It is imported (for back-end purposes)
899 -- if the designated type is.
901 Set_Is_Public (Anon_Type, Is_Public (Scope (Anon_Type)));
903 -- Ada 2005 (AI-231): Propagate the access-constant attribute
905 Set_Is_Access_Constant (Anon_Type, Constant_Present (N));
907 -- The context is either a subprogram declaration, object declaration,
908 -- or an access discriminant, in a private or a full type declaration.
909 -- In the case of a subprogram, if the designated type is incomplete,
910 -- the operation will be a primitive operation of the full type, to be
911 -- updated subsequently. If the type is imported through a limited_with
912 -- clause, the subprogram is not a primitive operation of the type
913 -- (which is declared elsewhere in some other scope).
915 if Ekind (Desig_Type) = E_Incomplete_Type
916 and then not From_Limited_With (Desig_Type)
917 and then Is_Overloadable (Current_Scope)
918 then
919 Append_Elmt (Current_Scope, Private_Dependents (Desig_Type));
920 Set_Has_Delayed_Freeze (Current_Scope);
921 end if;
923 -- Ada 2005: If the designated type is an interface that may contain
924 -- tasks, create a Master entity for the declaration. This must be done
925 -- before expansion of the full declaration, because the declaration may
926 -- include an expression that is an allocator, whose expansion needs the
927 -- proper Master for the created tasks.
929 if Nkind (Related_Nod) = N_Object_Declaration and then Expander_Active
930 then
931 if Is_Interface (Desig_Type) and then Is_Limited_Record (Desig_Type)
932 then
933 Build_Class_Wide_Master (Anon_Type);
935 -- Similarly, if the type is an anonymous access that designates
936 -- tasks, create a master entity for it in the current context.
938 elsif Has_Task (Desig_Type) and then Comes_From_Source (Related_Nod)
939 then
940 Build_Master_Entity (Defining_Identifier (Related_Nod));
941 Build_Master_Renaming (Anon_Type);
942 end if;
943 end if;
945 -- For a private component of a protected type, it is imperative that
946 -- the back-end elaborate the type immediately after the protected
947 -- declaration, because this type will be used in the declarations
948 -- created for the component within each protected body, so we must
949 -- create an itype reference for it now.
951 if Nkind (Parent (Related_Nod)) = N_Protected_Definition then
952 Build_Itype_Reference (Anon_Type, Parent (Parent (Related_Nod)));
954 -- Similarly, if the access definition is the return result of a
955 -- function, create an itype reference for it because it will be used
956 -- within the function body. For a regular function that is not a
957 -- compilation unit, insert reference after the declaration. For a
958 -- protected operation, insert it after the enclosing protected type
959 -- declaration. In either case, do not create a reference for a type
960 -- obtained through a limited_with clause, because this would introduce
961 -- semantic dependencies.
963 -- Similarly, do not create a reference if the designated type is a
964 -- generic formal, because no use of it will reach the backend.
966 elsif Nkind (Related_Nod) = N_Function_Specification
967 and then not From_Limited_With (Desig_Type)
968 and then not Is_Generic_Type (Desig_Type)
969 then
970 if Present (Enclosing_Prot_Type) then
971 Build_Itype_Reference (Anon_Type, Parent (Enclosing_Prot_Type));
973 elsif Is_List_Member (Parent (Related_Nod))
974 and then Nkind (Parent (N)) /= N_Parameter_Specification
975 then
976 Build_Itype_Reference (Anon_Type, Parent (Related_Nod));
977 end if;
979 -- Finally, create an itype reference for an object declaration of an
980 -- anonymous access type. This is strictly necessary only for deferred
981 -- constants, but in any case will avoid out-of-scope problems in the
982 -- back-end.
984 elsif Nkind (Related_Nod) = N_Object_Declaration then
985 Build_Itype_Reference (Anon_Type, Related_Nod);
986 end if;
988 return Anon_Type;
989 end Access_Definition;
991 -----------------------------------
992 -- Access_Subprogram_Declaration --
993 -----------------------------------
995 procedure Access_Subprogram_Declaration
996 (T_Name : Entity_Id;
997 T_Def : Node_Id)
999 procedure Check_For_Premature_Usage (Def : Node_Id);
1000 -- Check that type T_Name is not used, directly or recursively, as a
1001 -- parameter or a return type in Def. Def is either a subtype, an
1002 -- access_definition, or an access_to_subprogram_definition.
1004 -------------------------------
1005 -- Check_For_Premature_Usage --
1006 -------------------------------
1008 procedure Check_For_Premature_Usage (Def : Node_Id) is
1009 Param : Node_Id;
1011 begin
1012 -- Check for a subtype mark
1014 if Nkind (Def) in N_Has_Etype then
1015 if Etype (Def) = T_Name then
1016 Error_Msg_N
1017 ("type& cannot be used before end of its declaration", Def);
1018 end if;
1020 -- If this is not a subtype, then this is an access_definition
1022 elsif Nkind (Def) = N_Access_Definition then
1023 if Present (Access_To_Subprogram_Definition (Def)) then
1024 Check_For_Premature_Usage
1025 (Access_To_Subprogram_Definition (Def));
1026 else
1027 Check_For_Premature_Usage (Subtype_Mark (Def));
1028 end if;
1030 -- The only cases left are N_Access_Function_Definition and
1031 -- N_Access_Procedure_Definition.
1033 else
1034 if Present (Parameter_Specifications (Def)) then
1035 Param := First (Parameter_Specifications (Def));
1036 while Present (Param) loop
1037 Check_For_Premature_Usage (Parameter_Type (Param));
1038 Param := Next (Param);
1039 end loop;
1040 end if;
1042 if Nkind (Def) = N_Access_Function_Definition then
1043 Check_For_Premature_Usage (Result_Definition (Def));
1044 end if;
1045 end if;
1046 end Check_For_Premature_Usage;
1048 -- Local variables
1050 Formals : constant List_Id := Parameter_Specifications (T_Def);
1051 Formal : Entity_Id;
1052 D_Ityp : Node_Id;
1053 Desig_Type : constant Entity_Id :=
1054 Create_Itype (E_Subprogram_Type, Parent (T_Def));
1056 -- Start of processing for Access_Subprogram_Declaration
1058 begin
1059 Check_SPARK_05_Restriction ("access type is not allowed", T_Def);
1061 -- Associate the Itype node with the inner full-type declaration or
1062 -- subprogram spec or entry body. This is required to handle nested
1063 -- anonymous declarations. For example:
1065 -- procedure P
1066 -- (X : access procedure
1067 -- (Y : access procedure
1068 -- (Z : access T)))
1070 D_Ityp := Associated_Node_For_Itype (Desig_Type);
1071 while not (Nkind_In (D_Ityp, N_Full_Type_Declaration,
1072 N_Private_Type_Declaration,
1073 N_Private_Extension_Declaration,
1074 N_Procedure_Specification,
1075 N_Function_Specification,
1076 N_Entry_Body)
1078 or else
1079 Nkind_In (D_Ityp, N_Object_Declaration,
1080 N_Object_Renaming_Declaration,
1081 N_Formal_Object_Declaration,
1082 N_Formal_Type_Declaration,
1083 N_Task_Type_Declaration,
1084 N_Protected_Type_Declaration))
1085 loop
1086 D_Ityp := Parent (D_Ityp);
1087 pragma Assert (D_Ityp /= Empty);
1088 end loop;
1090 Set_Associated_Node_For_Itype (Desig_Type, D_Ityp);
1092 if Nkind_In (D_Ityp, N_Procedure_Specification,
1093 N_Function_Specification)
1094 then
1095 Set_Scope (Desig_Type, Scope (Defining_Entity (D_Ityp)));
1097 elsif Nkind_In (D_Ityp, N_Full_Type_Declaration,
1098 N_Object_Declaration,
1099 N_Object_Renaming_Declaration,
1100 N_Formal_Type_Declaration)
1101 then
1102 Set_Scope (Desig_Type, Scope (Defining_Identifier (D_Ityp)));
1103 end if;
1105 if Nkind (T_Def) = N_Access_Function_Definition then
1106 if Nkind (Result_Definition (T_Def)) = N_Access_Definition then
1107 declare
1108 Acc : constant Node_Id := Result_Definition (T_Def);
1110 begin
1111 if Present (Access_To_Subprogram_Definition (Acc))
1112 and then
1113 Protected_Present (Access_To_Subprogram_Definition (Acc))
1114 then
1115 Set_Etype
1116 (Desig_Type,
1117 Replace_Anonymous_Access_To_Protected_Subprogram
1118 (T_Def));
1120 else
1121 Set_Etype
1122 (Desig_Type,
1123 Access_Definition (T_Def, Result_Definition (T_Def)));
1124 end if;
1125 end;
1127 else
1128 Analyze (Result_Definition (T_Def));
1130 declare
1131 Typ : constant Entity_Id := Entity (Result_Definition (T_Def));
1133 begin
1134 -- If a null exclusion is imposed on the result type, then
1135 -- create a null-excluding itype (an access subtype) and use
1136 -- it as the function's Etype.
1138 if Is_Access_Type (Typ)
1139 and then Null_Exclusion_In_Return_Present (T_Def)
1140 then
1141 Set_Etype (Desig_Type,
1142 Create_Null_Excluding_Itype
1143 (T => Typ,
1144 Related_Nod => T_Def,
1145 Scope_Id => Current_Scope));
1147 else
1148 if From_Limited_With (Typ) then
1150 -- AI05-151: Incomplete types are allowed in all basic
1151 -- declarations, including access to subprograms.
1153 if Ada_Version >= Ada_2012 then
1154 null;
1156 else
1157 Error_Msg_NE
1158 ("illegal use of incomplete type&",
1159 Result_Definition (T_Def), Typ);
1160 end if;
1162 elsif Ekind (Current_Scope) = E_Package
1163 and then In_Private_Part (Current_Scope)
1164 then
1165 if Ekind (Typ) = E_Incomplete_Type then
1166 Append_Elmt (Desig_Type, Private_Dependents (Typ));
1168 elsif Is_Class_Wide_Type (Typ)
1169 and then Ekind (Etype (Typ)) = E_Incomplete_Type
1170 then
1171 Append_Elmt
1172 (Desig_Type, Private_Dependents (Etype (Typ)));
1173 end if;
1174 end if;
1176 Set_Etype (Desig_Type, Typ);
1177 end if;
1178 end;
1179 end if;
1181 if not (Is_Type (Etype (Desig_Type))) then
1182 Error_Msg_N
1183 ("expect type in function specification",
1184 Result_Definition (T_Def));
1185 end if;
1187 else
1188 Set_Etype (Desig_Type, Standard_Void_Type);
1189 end if;
1191 if Present (Formals) then
1192 Push_Scope (Desig_Type);
1194 -- Some special tests here. These special tests can be removed
1195 -- if and when Itypes always have proper parent pointers to their
1196 -- declarations???
1198 -- Special test 1) Link defining_identifier of formals. Required by
1199 -- First_Formal to provide its functionality.
1201 declare
1202 F : Node_Id;
1204 begin
1205 F := First (Formals);
1207 -- In ASIS mode, the access_to_subprogram may be analyzed twice,
1208 -- when it is part of an unconstrained type and subtype expansion
1209 -- is disabled. To avoid back-end problems with shared profiles,
1210 -- use previous subprogram type as the designated type, and then
1211 -- remove scope added above.
1213 if ASIS_Mode and then Present (Scope (Defining_Identifier (F)))
1214 then
1215 Set_Etype (T_Name, T_Name);
1216 Init_Size_Align (T_Name);
1217 Set_Directly_Designated_Type (T_Name,
1218 Scope (Defining_Identifier (F)));
1219 End_Scope;
1220 return;
1221 end if;
1223 while Present (F) loop
1224 if No (Parent (Defining_Identifier (F))) then
1225 Set_Parent (Defining_Identifier (F), F);
1226 end if;
1228 Next (F);
1229 end loop;
1230 end;
1232 Process_Formals (Formals, Parent (T_Def));
1234 -- Special test 2) End_Scope requires that the parent pointer be set
1235 -- to something reasonable, but Itypes don't have parent pointers. So
1236 -- we set it and then unset it ???
1238 Set_Parent (Desig_Type, T_Name);
1239 End_Scope;
1240 Set_Parent (Desig_Type, Empty);
1241 end if;
1243 -- Check for premature usage of the type being defined
1245 Check_For_Premature_Usage (T_Def);
1247 -- The return type and/or any parameter type may be incomplete. Mark the
1248 -- subprogram_type as depending on the incomplete type, so that it can
1249 -- be updated when the full type declaration is seen. This only applies
1250 -- to incomplete types declared in some enclosing scope, not to limited
1251 -- views from other packages.
1253 -- Prior to Ada 2012, access to functions can only have in_parameters.
1255 if Present (Formals) then
1256 Formal := First_Formal (Desig_Type);
1257 while Present (Formal) loop
1258 if Ekind (Formal) /= E_In_Parameter
1259 and then Nkind (T_Def) = N_Access_Function_Definition
1260 and then Ada_Version < Ada_2012
1261 then
1262 Error_Msg_N ("functions can only have IN parameters", Formal);
1263 end if;
1265 if Ekind (Etype (Formal)) = E_Incomplete_Type
1266 and then In_Open_Scopes (Scope (Etype (Formal)))
1267 then
1268 Append_Elmt (Desig_Type, Private_Dependents (Etype (Formal)));
1269 Set_Has_Delayed_Freeze (Desig_Type);
1270 end if;
1272 Next_Formal (Formal);
1273 end loop;
1274 end if;
1276 -- Check whether an indirect call without actuals may be possible. This
1277 -- is used when resolving calls whose result is then indexed.
1279 May_Need_Actuals (Desig_Type);
1281 -- If the return type is incomplete, this is legal as long as the type
1282 -- is declared in the current scope and will be completed in it (rather
1283 -- than being part of limited view).
1285 if Ekind (Etype (Desig_Type)) = E_Incomplete_Type
1286 and then not Has_Delayed_Freeze (Desig_Type)
1287 and then In_Open_Scopes (Scope (Etype (Desig_Type)))
1288 then
1289 Append_Elmt (Desig_Type, Private_Dependents (Etype (Desig_Type)));
1290 Set_Has_Delayed_Freeze (Desig_Type);
1291 end if;
1293 Check_Delayed_Subprogram (Desig_Type);
1295 if Protected_Present (T_Def) then
1296 Set_Ekind (T_Name, E_Access_Protected_Subprogram_Type);
1297 Set_Convention (Desig_Type, Convention_Protected);
1298 else
1299 Set_Ekind (T_Name, E_Access_Subprogram_Type);
1300 end if;
1302 Set_Can_Use_Internal_Rep (T_Name, not Always_Compatible_Rep_On_Target);
1304 Set_Etype (T_Name, T_Name);
1305 Init_Size_Align (T_Name);
1306 Set_Directly_Designated_Type (T_Name, Desig_Type);
1308 Generate_Reference_To_Formals (T_Name);
1310 -- Ada 2005 (AI-231): Propagate the null-excluding attribute
1312 Set_Can_Never_Be_Null (T_Name, Null_Exclusion_Present (T_Def));
1314 Check_Restriction (No_Access_Subprograms, T_Def);
1315 end Access_Subprogram_Declaration;
1317 ----------------------------
1318 -- Access_Type_Declaration --
1319 ----------------------------
1321 procedure Access_Type_Declaration (T : Entity_Id; Def : Node_Id) is
1322 P : constant Node_Id := Parent (Def);
1323 S : constant Node_Id := Subtype_Indication (Def);
1325 Full_Desig : Entity_Id;
1327 begin
1328 Check_SPARK_05_Restriction ("access type is not allowed", Def);
1330 -- Check for permissible use of incomplete type
1332 if Nkind (S) /= N_Subtype_Indication then
1333 Analyze (S);
1335 if Present (Entity (S))
1336 and then Ekind (Root_Type (Entity (S))) = E_Incomplete_Type
1337 then
1338 Set_Directly_Designated_Type (T, Entity (S));
1340 -- If the designated type is a limited view, we cannot tell if
1341 -- the full view contains tasks, and there is no way to handle
1342 -- that full view in a client. We create a master entity for the
1343 -- scope, which will be used when a client determines that one
1344 -- is needed.
1346 if From_Limited_With (Entity (S))
1347 and then not Is_Class_Wide_Type (Entity (S))
1348 then
1349 Set_Ekind (T, E_Access_Type);
1350 Build_Master_Entity (T);
1351 Build_Master_Renaming (T);
1352 end if;
1354 else
1355 Set_Directly_Designated_Type (T, Process_Subtype (S, P, T, 'P'));
1356 end if;
1358 -- If the access definition is of the form: ACCESS NOT NULL ..
1359 -- the subtype indication must be of an access type. Create
1360 -- a null-excluding subtype of it.
1362 if Null_Excluding_Subtype (Def) then
1363 if not Is_Access_Type (Entity (S)) then
1364 Error_Msg_N ("null exclusion must apply to access type", Def);
1366 else
1367 declare
1368 Loc : constant Source_Ptr := Sloc (S);
1369 Decl : Node_Id;
1370 Nam : constant Entity_Id := Make_Temporary (Loc, 'S');
1372 begin
1373 Decl :=
1374 Make_Subtype_Declaration (Loc,
1375 Defining_Identifier => Nam,
1376 Subtype_Indication =>
1377 New_Occurrence_Of (Entity (S), Loc));
1378 Set_Null_Exclusion_Present (Decl);
1379 Insert_Before (Parent (Def), Decl);
1380 Analyze (Decl);
1381 Set_Entity (S, Nam);
1382 end;
1383 end if;
1384 end if;
1386 else
1387 Set_Directly_Designated_Type (T,
1388 Process_Subtype (S, P, T, 'P'));
1389 end if;
1391 if All_Present (Def) or Constant_Present (Def) then
1392 Set_Ekind (T, E_General_Access_Type);
1393 else
1394 Set_Ekind (T, E_Access_Type);
1395 end if;
1397 Full_Desig := Designated_Type (T);
1399 if Base_Type (Full_Desig) = T then
1400 Error_Msg_N ("access type cannot designate itself", S);
1402 -- In Ada 2005, the type may have a limited view through some unit in
1403 -- its own context, allowing the following circularity that cannot be
1404 -- detected earlier.
1406 elsif Is_Class_Wide_Type (Full_Desig) and then Etype (Full_Desig) = T
1407 then
1408 Error_Msg_N
1409 ("access type cannot designate its own class-wide type", S);
1411 -- Clean up indication of tagged status to prevent cascaded errors
1413 Set_Is_Tagged_Type (T, False);
1414 end if;
1416 Set_Etype (T, T);
1418 -- If the type has appeared already in a with_type clause, it is frozen
1419 -- and the pointer size is already set. Else, initialize.
1421 if not From_Limited_With (T) then
1422 Init_Size_Align (T);
1423 end if;
1425 -- Note that Has_Task is always false, since the access type itself
1426 -- is not a task type. See Einfo for more description on this point.
1427 -- Exactly the same consideration applies to Has_Controlled_Component
1428 -- and to Has_Protected.
1430 Set_Has_Task (T, False);
1431 Set_Has_Protected (T, False);
1432 Set_Has_Timing_Event (T, False);
1433 Set_Has_Controlled_Component (T, False);
1435 -- Initialize field Finalization_Master explicitly to Empty, to avoid
1436 -- problems where an incomplete view of this entity has been previously
1437 -- established by a limited with and an overlaid version of this field
1438 -- (Stored_Constraint) was initialized for the incomplete view.
1440 -- This reset is performed in most cases except where the access type
1441 -- has been created for the purposes of allocating or deallocating a
1442 -- build-in-place object. Such access types have explicitly set pools
1443 -- and finalization masters.
1445 if No (Associated_Storage_Pool (T)) then
1446 Set_Finalization_Master (T, Empty);
1447 end if;
1449 -- Ada 2005 (AI-231): Propagate the null-excluding and access-constant
1450 -- attributes
1452 Set_Can_Never_Be_Null (T, Null_Exclusion_Present (Def));
1453 Set_Is_Access_Constant (T, Constant_Present (Def));
1454 end Access_Type_Declaration;
1456 ----------------------------------
1457 -- Add_Interface_Tag_Components --
1458 ----------------------------------
1460 procedure Add_Interface_Tag_Components (N : Node_Id; Typ : Entity_Id) is
1461 Loc : constant Source_Ptr := Sloc (N);
1462 L : List_Id;
1463 Last_Tag : Node_Id;
1465 procedure Add_Tag (Iface : Entity_Id);
1466 -- Add tag for one of the progenitor interfaces
1468 -------------
1469 -- Add_Tag --
1470 -------------
1472 procedure Add_Tag (Iface : Entity_Id) is
1473 Decl : Node_Id;
1474 Def : Node_Id;
1475 Tag : Entity_Id;
1476 Offset : Entity_Id;
1478 begin
1479 pragma Assert (Is_Tagged_Type (Iface) and then Is_Interface (Iface));
1481 -- This is a reasonable place to propagate predicates
1483 if Has_Predicates (Iface) then
1484 Set_Has_Predicates (Typ);
1485 end if;
1487 Def :=
1488 Make_Component_Definition (Loc,
1489 Aliased_Present => True,
1490 Subtype_Indication =>
1491 New_Occurrence_Of (RTE (RE_Interface_Tag), Loc));
1493 Tag := Make_Temporary (Loc, 'V');
1495 Decl :=
1496 Make_Component_Declaration (Loc,
1497 Defining_Identifier => Tag,
1498 Component_Definition => Def);
1500 Analyze_Component_Declaration (Decl);
1502 Set_Analyzed (Decl);
1503 Set_Ekind (Tag, E_Component);
1504 Set_Is_Tag (Tag);
1505 Set_Is_Aliased (Tag);
1506 Set_Related_Type (Tag, Iface);
1507 Init_Component_Location (Tag);
1509 pragma Assert (Is_Frozen (Iface));
1511 Set_DT_Entry_Count (Tag,
1512 DT_Entry_Count (First_Entity (Iface)));
1514 if No (Last_Tag) then
1515 Prepend (Decl, L);
1516 else
1517 Insert_After (Last_Tag, Decl);
1518 end if;
1520 Last_Tag := Decl;
1522 -- If the ancestor has discriminants we need to give special support
1523 -- to store the offset_to_top value of the secondary dispatch tables.
1524 -- For this purpose we add a supplementary component just after the
1525 -- field that contains the tag associated with each secondary DT.
1527 if Typ /= Etype (Typ) and then Has_Discriminants (Etype (Typ)) then
1528 Def :=
1529 Make_Component_Definition (Loc,
1530 Subtype_Indication =>
1531 New_Occurrence_Of (RTE (RE_Storage_Offset), Loc));
1533 Offset := Make_Temporary (Loc, 'V');
1535 Decl :=
1536 Make_Component_Declaration (Loc,
1537 Defining_Identifier => Offset,
1538 Component_Definition => Def);
1540 Analyze_Component_Declaration (Decl);
1542 Set_Analyzed (Decl);
1543 Set_Ekind (Offset, E_Component);
1544 Set_Is_Aliased (Offset);
1545 Set_Related_Type (Offset, Iface);
1546 Init_Component_Location (Offset);
1547 Insert_After (Last_Tag, Decl);
1548 Last_Tag := Decl;
1549 end if;
1550 end Add_Tag;
1552 -- Local variables
1554 Elmt : Elmt_Id;
1555 Ext : Node_Id;
1556 Comp : Node_Id;
1558 -- Start of processing for Add_Interface_Tag_Components
1560 begin
1561 if not RTE_Available (RE_Interface_Tag) then
1562 Error_Msg
1563 ("(Ada 2005) interface types not supported by this run-time!",
1564 Sloc (N));
1565 return;
1566 end if;
1568 if Ekind (Typ) /= E_Record_Type
1569 or else (Is_Concurrent_Record_Type (Typ)
1570 and then Is_Empty_List (Abstract_Interface_List (Typ)))
1571 or else (not Is_Concurrent_Record_Type (Typ)
1572 and then No (Interfaces (Typ))
1573 and then Is_Empty_Elmt_List (Interfaces (Typ)))
1574 then
1575 return;
1576 end if;
1578 -- Find the current last tag
1580 if Nkind (Type_Definition (N)) = N_Derived_Type_Definition then
1581 Ext := Record_Extension_Part (Type_Definition (N));
1582 else
1583 pragma Assert (Nkind (Type_Definition (N)) = N_Record_Definition);
1584 Ext := Type_Definition (N);
1585 end if;
1587 Last_Tag := Empty;
1589 if not (Present (Component_List (Ext))) then
1590 Set_Null_Present (Ext, False);
1591 L := New_List;
1592 Set_Component_List (Ext,
1593 Make_Component_List (Loc,
1594 Component_Items => L,
1595 Null_Present => False));
1596 else
1597 if Nkind (Type_Definition (N)) = N_Derived_Type_Definition then
1598 L := Component_Items
1599 (Component_List
1600 (Record_Extension_Part
1601 (Type_Definition (N))));
1602 else
1603 L := Component_Items
1604 (Component_List
1605 (Type_Definition (N)));
1606 end if;
1608 -- Find the last tag component
1610 Comp := First (L);
1611 while Present (Comp) loop
1612 if Nkind (Comp) = N_Component_Declaration
1613 and then Is_Tag (Defining_Identifier (Comp))
1614 then
1615 Last_Tag := Comp;
1616 end if;
1618 Next (Comp);
1619 end loop;
1620 end if;
1622 -- At this point L references the list of components and Last_Tag
1623 -- references the current last tag (if any). Now we add the tag
1624 -- corresponding with all the interfaces that are not implemented
1625 -- by the parent.
1627 if Present (Interfaces (Typ)) then
1628 Elmt := First_Elmt (Interfaces (Typ));
1629 while Present (Elmt) loop
1630 Add_Tag (Node (Elmt));
1631 Next_Elmt (Elmt);
1632 end loop;
1633 end if;
1634 end Add_Interface_Tag_Components;
1636 -------------------------------------
1637 -- Add_Internal_Interface_Entities --
1638 -------------------------------------
1640 procedure Add_Internal_Interface_Entities (Tagged_Type : Entity_Id) is
1641 Elmt : Elmt_Id;
1642 Iface : Entity_Id;
1643 Iface_Elmt : Elmt_Id;
1644 Iface_Prim : Entity_Id;
1645 Ifaces_List : Elist_Id;
1646 New_Subp : Entity_Id := Empty;
1647 Prim : Entity_Id;
1648 Restore_Scope : Boolean := False;
1650 begin
1651 pragma Assert (Ada_Version >= Ada_2005
1652 and then Is_Record_Type (Tagged_Type)
1653 and then Is_Tagged_Type (Tagged_Type)
1654 and then Has_Interfaces (Tagged_Type)
1655 and then not Is_Interface (Tagged_Type));
1657 -- Ensure that the internal entities are added to the scope of the type
1659 if Scope (Tagged_Type) /= Current_Scope then
1660 Push_Scope (Scope (Tagged_Type));
1661 Restore_Scope := True;
1662 end if;
1664 Collect_Interfaces (Tagged_Type, Ifaces_List);
1666 Iface_Elmt := First_Elmt (Ifaces_List);
1667 while Present (Iface_Elmt) loop
1668 Iface := Node (Iface_Elmt);
1670 -- Originally we excluded here from this processing interfaces that
1671 -- are parents of Tagged_Type because their primitives are located
1672 -- in the primary dispatch table (and hence no auxiliary internal
1673 -- entities are required to handle secondary dispatch tables in such
1674 -- case). However, these auxiliary entities are also required to
1675 -- handle derivations of interfaces in formals of generics (see
1676 -- Derive_Subprograms).
1678 Elmt := First_Elmt (Primitive_Operations (Iface));
1679 while Present (Elmt) loop
1680 Iface_Prim := Node (Elmt);
1682 if not Is_Predefined_Dispatching_Operation (Iface_Prim) then
1683 Prim :=
1684 Find_Primitive_Covering_Interface
1685 (Tagged_Type => Tagged_Type,
1686 Iface_Prim => Iface_Prim);
1688 if No (Prim) and then Serious_Errors_Detected > 0 then
1689 goto Continue;
1690 end if;
1692 pragma Assert (Present (Prim));
1694 -- Ada 2012 (AI05-0197): If the name of the covering primitive
1695 -- differs from the name of the interface primitive then it is
1696 -- a private primitive inherited from a parent type. In such
1697 -- case, given that Tagged_Type covers the interface, the
1698 -- inherited private primitive becomes visible. For such
1699 -- purpose we add a new entity that renames the inherited
1700 -- private primitive.
1702 if Chars (Prim) /= Chars (Iface_Prim) then
1703 pragma Assert (Has_Suffix (Prim, 'P'));
1704 Derive_Subprogram
1705 (New_Subp => New_Subp,
1706 Parent_Subp => Iface_Prim,
1707 Derived_Type => Tagged_Type,
1708 Parent_Type => Iface);
1709 Set_Alias (New_Subp, Prim);
1710 Set_Is_Abstract_Subprogram
1711 (New_Subp, Is_Abstract_Subprogram (Prim));
1712 end if;
1714 Derive_Subprogram
1715 (New_Subp => New_Subp,
1716 Parent_Subp => Iface_Prim,
1717 Derived_Type => Tagged_Type,
1718 Parent_Type => Iface);
1720 declare
1721 Anc : Entity_Id;
1722 begin
1723 if Is_Inherited_Operation (Prim)
1724 and then Present (Alias (Prim))
1725 then
1726 Anc := Alias (Prim);
1727 else
1728 Anc := Overridden_Operation (Prim);
1729 end if;
1731 -- Apply legality checks in RM 6.1.1 (10-13) concerning
1732 -- nonconforming preconditions in both an ancestor and
1733 -- a progenitor operation.
1735 -- If the operation is a primitive wrapper it is an explicit
1736 -- (overriding) operqtion and all is fine.
1738 if Present (Anc)
1739 and then Has_Non_Trivial_Precondition (Anc)
1740 and then Has_Non_Trivial_Precondition (Iface_Prim)
1741 then
1742 if Is_Abstract_Subprogram (Prim)
1743 or else
1744 (Ekind (Prim) = E_Procedure
1745 and then Nkind (Parent (Prim)) =
1746 N_Procedure_Specification
1747 and then Null_Present (Parent (Prim)))
1748 or else Is_Primitive_Wrapper (Prim)
1749 then
1750 null;
1752 -- The operation is inherited and must be overridden
1754 elsif not Comes_From_Source (Prim) then
1755 Error_Msg_NE
1756 ("&inherits non-conforming preconditions and must "
1757 & "be overridden (RM 6.1.1 (10-16)",
1758 Parent (Tagged_Type), Prim);
1759 end if;
1760 end if;
1761 end;
1763 -- Ada 2005 (AI-251): Decorate internal entity Iface_Subp
1764 -- associated with interface types. These entities are
1765 -- only registered in the list of primitives of its
1766 -- corresponding tagged type because they are only used
1767 -- to fill the contents of the secondary dispatch tables.
1768 -- Therefore they are removed from the homonym chains.
1770 Set_Is_Hidden (New_Subp);
1771 Set_Is_Internal (New_Subp);
1772 Set_Alias (New_Subp, Prim);
1773 Set_Is_Abstract_Subprogram
1774 (New_Subp, Is_Abstract_Subprogram (Prim));
1775 Set_Interface_Alias (New_Subp, Iface_Prim);
1777 -- If the returned type is an interface then propagate it to
1778 -- the returned type. Needed by the thunk to generate the code
1779 -- which displaces "this" to reference the corresponding
1780 -- secondary dispatch table in the returned object.
1782 if Is_Interface (Etype (Iface_Prim)) then
1783 Set_Etype (New_Subp, Etype (Iface_Prim));
1784 end if;
1786 -- Internal entities associated with interface types are only
1787 -- registered in the list of primitives of the tagged type.
1788 -- They are only used to fill the contents of the secondary
1789 -- dispatch tables. Therefore they are not needed in the
1790 -- homonym chains.
1792 Remove_Homonym (New_Subp);
1794 -- Hidden entities associated with interfaces must have set
1795 -- the Has_Delay_Freeze attribute to ensure that, in case
1796 -- of locally defined tagged types (or compiling with static
1797 -- dispatch tables generation disabled) the corresponding
1798 -- entry of the secondary dispatch table is filled when such
1799 -- an entity is frozen. This is an expansion activity that must
1800 -- be suppressed for ASIS because it leads to gigi elaboration
1801 -- issues in annotate mode.
1803 if not ASIS_Mode then
1804 Set_Has_Delayed_Freeze (New_Subp);
1805 end if;
1806 end if;
1808 <<Continue>>
1809 Next_Elmt (Elmt);
1810 end loop;
1812 Next_Elmt (Iface_Elmt);
1813 end loop;
1815 if Restore_Scope then
1816 Pop_Scope;
1817 end if;
1818 end Add_Internal_Interface_Entities;
1820 -----------------------------------
1821 -- Analyze_Component_Declaration --
1822 -----------------------------------
1824 procedure Analyze_Component_Declaration (N : Node_Id) is
1825 Loc : constant Source_Ptr := Sloc (Component_Definition (N));
1826 Id : constant Entity_Id := Defining_Identifier (N);
1827 E : constant Node_Id := Expression (N);
1828 Typ : constant Node_Id :=
1829 Subtype_Indication (Component_Definition (N));
1830 T : Entity_Id;
1831 P : Entity_Id;
1833 function Contains_POC (Constr : Node_Id) return Boolean;
1834 -- Determines whether a constraint uses the discriminant of a record
1835 -- type thus becoming a per-object constraint (POC).
1837 function Is_Known_Limited (Typ : Entity_Id) return Boolean;
1838 -- Typ is the type of the current component, check whether this type is
1839 -- a limited type. Used to validate declaration against that of
1840 -- enclosing record.
1842 ------------------
1843 -- Contains_POC --
1844 ------------------
1846 function Contains_POC (Constr : Node_Id) return Boolean is
1847 begin
1848 -- Prevent cascaded errors
1850 if Error_Posted (Constr) then
1851 return False;
1852 end if;
1854 case Nkind (Constr) is
1855 when N_Attribute_Reference =>
1856 return Attribute_Name (Constr) = Name_Access
1857 and then Prefix (Constr) = Scope (Entity (Prefix (Constr)));
1859 when N_Discriminant_Association =>
1860 return Denotes_Discriminant (Expression (Constr));
1862 when N_Identifier =>
1863 return Denotes_Discriminant (Constr);
1865 when N_Index_Or_Discriminant_Constraint =>
1866 declare
1867 IDC : Node_Id;
1869 begin
1870 IDC := First (Constraints (Constr));
1871 while Present (IDC) loop
1873 -- One per-object constraint is sufficient
1875 if Contains_POC (IDC) then
1876 return True;
1877 end if;
1879 Next (IDC);
1880 end loop;
1882 return False;
1883 end;
1885 when N_Range =>
1886 return Denotes_Discriminant (Low_Bound (Constr))
1887 or else
1888 Denotes_Discriminant (High_Bound (Constr));
1890 when N_Range_Constraint =>
1891 return Denotes_Discriminant (Range_Expression (Constr));
1893 when others =>
1894 return False;
1895 end case;
1896 end Contains_POC;
1898 ----------------------
1899 -- Is_Known_Limited --
1900 ----------------------
1902 function Is_Known_Limited (Typ : Entity_Id) return Boolean is
1903 P : constant Entity_Id := Etype (Typ);
1904 R : constant Entity_Id := Root_Type (Typ);
1906 begin
1907 if Is_Limited_Record (Typ) then
1908 return True;
1910 -- If the root type is limited (and not a limited interface)
1911 -- so is the current type
1913 elsif Is_Limited_Record (R)
1914 and then (not Is_Interface (R) or else not Is_Limited_Interface (R))
1915 then
1916 return True;
1918 -- Else the type may have a limited interface progenitor, but a
1919 -- limited record parent.
1921 elsif R /= P and then Is_Limited_Record (P) then
1922 return True;
1924 else
1925 return False;
1926 end if;
1927 end Is_Known_Limited;
1929 -- Start of processing for Analyze_Component_Declaration
1931 begin
1932 Generate_Definition (Id);
1933 Enter_Name (Id);
1935 if Present (Typ) then
1936 T := Find_Type_Of_Object
1937 (Subtype_Indication (Component_Definition (N)), N);
1939 if not Nkind_In (Typ, N_Identifier, N_Expanded_Name) then
1940 Check_SPARK_05_Restriction ("subtype mark required", Typ);
1941 end if;
1943 -- Ada 2005 (AI-230): Access Definition case
1945 else
1946 pragma Assert (Present
1947 (Access_Definition (Component_Definition (N))));
1949 T := Access_Definition
1950 (Related_Nod => N,
1951 N => Access_Definition (Component_Definition (N)));
1952 Set_Is_Local_Anonymous_Access (T);
1954 -- Ada 2005 (AI-254)
1956 if Present (Access_To_Subprogram_Definition
1957 (Access_Definition (Component_Definition (N))))
1958 and then Protected_Present (Access_To_Subprogram_Definition
1959 (Access_Definition
1960 (Component_Definition (N))))
1961 then
1962 T := Replace_Anonymous_Access_To_Protected_Subprogram (N);
1963 end if;
1964 end if;
1966 -- If the subtype is a constrained subtype of the enclosing record,
1967 -- (which must have a partial view) the back-end does not properly
1968 -- handle the recursion. Rewrite the component declaration with an
1969 -- explicit subtype indication, which is acceptable to Gigi. We can copy
1970 -- the tree directly because side effects have already been removed from
1971 -- discriminant constraints.
1973 if Ekind (T) = E_Access_Subtype
1974 and then Is_Entity_Name (Subtype_Indication (Component_Definition (N)))
1975 and then Comes_From_Source (T)
1976 and then Nkind (Parent (T)) = N_Subtype_Declaration
1977 and then Etype (Directly_Designated_Type (T)) = Current_Scope
1978 then
1979 Rewrite
1980 (Subtype_Indication (Component_Definition (N)),
1981 New_Copy_Tree (Subtype_Indication (Parent (T))));
1982 T := Find_Type_Of_Object
1983 (Subtype_Indication (Component_Definition (N)), N);
1984 end if;
1986 -- If the component declaration includes a default expression, then we
1987 -- check that the component is not of a limited type (RM 3.7(5)),
1988 -- and do the special preanalysis of the expression (see section on
1989 -- "Handling of Default and Per-Object Expressions" in the spec of
1990 -- package Sem).
1992 if Present (E) then
1993 Check_SPARK_05_Restriction ("default expression is not allowed", E);
1994 Preanalyze_Default_Expression (E, T);
1995 Check_Initialization (T, E);
1997 if Ada_Version >= Ada_2005
1998 and then Ekind (T) = E_Anonymous_Access_Type
1999 and then Etype (E) /= Any_Type
2000 then
2001 -- Check RM 3.9.2(9): "if the expected type for an expression is
2002 -- an anonymous access-to-specific tagged type, then the object
2003 -- designated by the expression shall not be dynamically tagged
2004 -- unless it is a controlling operand in a call on a dispatching
2005 -- operation"
2007 if Is_Tagged_Type (Directly_Designated_Type (T))
2008 and then
2009 Ekind (Directly_Designated_Type (T)) /= E_Class_Wide_Type
2010 and then
2011 Ekind (Directly_Designated_Type (Etype (E))) =
2012 E_Class_Wide_Type
2013 then
2014 Error_Msg_N
2015 ("access to specific tagged type required (RM 3.9.2(9))", E);
2016 end if;
2018 -- (Ada 2005: AI-230): Accessibility check for anonymous
2019 -- components
2021 if Type_Access_Level (Etype (E)) >
2022 Deepest_Type_Access_Level (T)
2023 then
2024 Error_Msg_N
2025 ("expression has deeper access level than component " &
2026 "(RM 3.10.2 (12.2))", E);
2027 end if;
2029 -- The initialization expression is a reference to an access
2030 -- discriminant. The type of the discriminant is always deeper
2031 -- than any access type.
2033 if Ekind (Etype (E)) = E_Anonymous_Access_Type
2034 and then Is_Entity_Name (E)
2035 and then Ekind (Entity (E)) = E_In_Parameter
2036 and then Present (Discriminal_Link (Entity (E)))
2037 then
2038 Error_Msg_N
2039 ("discriminant has deeper accessibility level than target",
2041 end if;
2042 end if;
2043 end if;
2045 -- The parent type may be a private view with unknown discriminants,
2046 -- and thus unconstrained. Regular components must be constrained.
2048 if not Is_Definite_Subtype (T) and then Chars (Id) /= Name_uParent then
2049 if Is_Class_Wide_Type (T) then
2050 Error_Msg_N
2051 ("class-wide subtype with unknown discriminants" &
2052 " in component declaration",
2053 Subtype_Indication (Component_Definition (N)));
2054 else
2055 Error_Msg_N
2056 ("unconstrained subtype in component declaration",
2057 Subtype_Indication (Component_Definition (N)));
2058 end if;
2060 -- Components cannot be abstract, except for the special case of
2061 -- the _Parent field (case of extending an abstract tagged type)
2063 elsif Is_Abstract_Type (T) and then Chars (Id) /= Name_uParent then
2064 Error_Msg_N ("type of a component cannot be abstract", N);
2065 end if;
2067 Set_Etype (Id, T);
2068 Set_Is_Aliased (Id, Aliased_Present (Component_Definition (N)));
2070 -- The component declaration may have a per-object constraint, set
2071 -- the appropriate flag in the defining identifier of the subtype.
2073 if Present (Subtype_Indication (Component_Definition (N))) then
2074 declare
2075 Sindic : constant Node_Id :=
2076 Subtype_Indication (Component_Definition (N));
2077 begin
2078 if Nkind (Sindic) = N_Subtype_Indication
2079 and then Present (Constraint (Sindic))
2080 and then Contains_POC (Constraint (Sindic))
2081 then
2082 Set_Has_Per_Object_Constraint (Id);
2083 end if;
2084 end;
2085 end if;
2087 -- Ada 2005 (AI-231): Propagate the null-excluding attribute and carry
2088 -- out some static checks.
2090 if Ada_Version >= Ada_2005 and then Can_Never_Be_Null (T) then
2091 Null_Exclusion_Static_Checks (N);
2092 end if;
2094 -- If this component is private (or depends on a private type), flag the
2095 -- record type to indicate that some operations are not available.
2097 P := Private_Component (T);
2099 if Present (P) then
2101 -- Check for circular definitions
2103 if P = Any_Type then
2104 Set_Etype (Id, Any_Type);
2106 -- There is a gap in the visibility of operations only if the
2107 -- component type is not defined in the scope of the record type.
2109 elsif Scope (P) = Scope (Current_Scope) then
2110 null;
2112 elsif Is_Limited_Type (P) then
2113 Set_Is_Limited_Composite (Current_Scope);
2115 else
2116 Set_Is_Private_Composite (Current_Scope);
2117 end if;
2118 end if;
2120 if P /= Any_Type
2121 and then Is_Limited_Type (T)
2122 and then Chars (Id) /= Name_uParent
2123 and then Is_Tagged_Type (Current_Scope)
2124 then
2125 if Is_Derived_Type (Current_Scope)
2126 and then not Is_Known_Limited (Current_Scope)
2127 then
2128 Error_Msg_N
2129 ("extension of nonlimited type cannot have limited components",
2132 if Is_Interface (Root_Type (Current_Scope)) then
2133 Error_Msg_N
2134 ("\limitedness is not inherited from limited interface", N);
2135 Error_Msg_N ("\add LIMITED to type indication", N);
2136 end if;
2138 Explain_Limited_Type (T, N);
2139 Set_Etype (Id, Any_Type);
2140 Set_Is_Limited_Composite (Current_Scope, False);
2142 elsif not Is_Derived_Type (Current_Scope)
2143 and then not Is_Limited_Record (Current_Scope)
2144 and then not Is_Concurrent_Type (Current_Scope)
2145 then
2146 Error_Msg_N
2147 ("nonlimited tagged type cannot have limited components", N);
2148 Explain_Limited_Type (T, N);
2149 Set_Etype (Id, Any_Type);
2150 Set_Is_Limited_Composite (Current_Scope, False);
2151 end if;
2152 end if;
2154 -- If the component is an unconstrained task or protected type with
2155 -- discriminants, the component and the enclosing record are limited
2156 -- and the component is constrained by its default values. Compute
2157 -- its actual subtype, else it may be allocated the maximum size by
2158 -- the backend, and possibly overflow.
2160 if Is_Concurrent_Type (T)
2161 and then not Is_Constrained (T)
2162 and then Has_Discriminants (T)
2163 and then not Has_Discriminants (Current_Scope)
2164 then
2165 declare
2166 Act_T : constant Entity_Id := Build_Default_Subtype (T, N);
2168 begin
2169 Set_Etype (Id, Act_T);
2171 -- Rewrite component definition to use the constrained subtype
2173 Rewrite (Component_Definition (N),
2174 Make_Component_Definition (Loc,
2175 Subtype_Indication => New_Occurrence_Of (Act_T, Loc)));
2176 end;
2177 end if;
2179 Set_Original_Record_Component (Id, Id);
2181 if Has_Aspects (N) then
2182 Analyze_Aspect_Specifications (N, Id);
2183 end if;
2185 Analyze_Dimension (N);
2186 end Analyze_Component_Declaration;
2188 --------------------------
2189 -- Analyze_Declarations --
2190 --------------------------
2192 procedure Analyze_Declarations (L : List_Id) is
2193 Decl : Node_Id;
2195 procedure Adjust_Decl;
2196 -- Adjust Decl not to include implicit label declarations, since these
2197 -- have strange Sloc values that result in elaboration check problems.
2198 -- (They have the sloc of the label as found in the source, and that
2199 -- is ahead of the current declarative part).
2201 procedure Build_Assertion_Bodies (Decls : List_Id; Context : Node_Id);
2202 -- Create the subprogram bodies which verify the run-time semantics of
2203 -- the pragmas listed below for each elibigle type found in declarative
2204 -- list Decls. The pragmas are:
2206 -- Default_Initial_Condition
2207 -- Invariant
2208 -- Type_Invariant
2210 -- Context denotes the owner of the declarative list.
2212 procedure Check_Entry_Contracts;
2213 -- Perform a pre-analysis of the pre- and postconditions of an entry
2214 -- declaration. This must be done before full resolution and creation
2215 -- of the parameter block, etc. to catch illegal uses within the
2216 -- contract expression. Full analysis of the expression is done when
2217 -- the contract is processed.
2219 function Contains_Lib_Incomplete_Type (Pkg : Entity_Id) return Boolean;
2220 -- Check if a nested package has entities within it that rely on library
2221 -- level private types where the full view has not been completed for
2222 -- the purposes of checking if it is acceptable to freeze an expression
2223 -- function at the point of declaration.
2225 procedure Handle_Late_Controlled_Primitive (Body_Decl : Node_Id);
2226 -- Determine whether Body_Decl denotes the body of a late controlled
2227 -- primitive (either Initialize, Adjust or Finalize). If this is the
2228 -- case, add a proper spec if the body lacks one. The spec is inserted
2229 -- before Body_Decl and immediately analyzed.
2231 procedure Remove_Partial_Visible_Refinements (Spec_Id : Entity_Id);
2232 -- Spec_Id is the entity of a package that may define abstract states,
2233 -- and in the case of a child unit, whose ancestors may define abstract
2234 -- states. If the states have partial visible refinement, remove the
2235 -- partial visibility of each constituent at the end of the package
2236 -- spec and body declarations.
2238 procedure Remove_Visible_Refinements (Spec_Id : Entity_Id);
2239 -- Spec_Id is the entity of a package that may define abstract states.
2240 -- If the states have visible refinement, remove the visibility of each
2241 -- constituent at the end of the package body declaration.
2243 procedure Resolve_Aspects;
2244 -- Utility to resolve the expressions of aspects at the end of a list of
2245 -- declarations, or before a declaration that freezes previous entities,
2246 -- such as in a subprogram body.
2248 -----------------
2249 -- Adjust_Decl --
2250 -----------------
2252 procedure Adjust_Decl is
2253 begin
2254 while Present (Prev (Decl))
2255 and then Nkind (Decl) = N_Implicit_Label_Declaration
2256 loop
2257 Prev (Decl);
2258 end loop;
2259 end Adjust_Decl;
2261 ----------------------------
2262 -- Build_Assertion_Bodies --
2263 ----------------------------
2265 procedure Build_Assertion_Bodies (Decls : List_Id; Context : Node_Id) is
2266 procedure Build_Assertion_Bodies_For_Type (Typ : Entity_Id);
2267 -- Create the subprogram bodies which verify the run-time semantics
2268 -- of the pragmas listed below for type Typ. The pragmas are:
2270 -- Default_Initial_Condition
2271 -- Invariant
2272 -- Type_Invariant
2274 -------------------------------------
2275 -- Build_Assertion_Bodies_For_Type --
2276 -------------------------------------
2278 procedure Build_Assertion_Bodies_For_Type (Typ : Entity_Id) is
2279 begin
2280 -- Preanalyze and resolve the Default_Initial_Condition assertion
2281 -- expression at the end of the declarations to catch any errors.
2283 if Has_DIC (Typ) then
2284 Build_DIC_Procedure_Body (Typ);
2285 end if;
2287 if Nkind (Context) = N_Package_Specification then
2289 -- Preanalyze and resolve the class-wide invariants of an
2290 -- interface at the end of whichever declarative part has the
2291 -- interface type. Note that an interface may be declared in
2292 -- any non-package declarative part, but reaching the end of
2293 -- such a declarative part will always freeze the type and
2294 -- generate the invariant procedure (see Freeze_Type).
2296 if Is_Interface (Typ) then
2298 -- Interfaces are treated as the partial view of a private
2299 -- type, in order to achieve uniformity with the general
2300 -- case. As a result, an interface receives only a "partial"
2301 -- invariant procedure, which is never called.
2303 if Has_Own_Invariants (Typ) then
2304 Build_Invariant_Procedure_Body
2305 (Typ => Typ,
2306 Partial_Invariant => True);
2307 end if;
2309 -- Preanalyze and resolve the invariants of a private type
2310 -- at the end of the visible declarations to catch potential
2311 -- errors. Inherited class-wide invariants are not included
2312 -- because they have already been resolved.
2314 elsif Decls = Visible_Declarations (Context)
2315 and then Ekind_In (Typ, E_Limited_Private_Type,
2316 E_Private_Type,
2317 E_Record_Type_With_Private)
2318 and then Has_Own_Invariants (Typ)
2319 then
2320 Build_Invariant_Procedure_Body
2321 (Typ => Typ,
2322 Partial_Invariant => True);
2324 -- Preanalyze and resolve the invariants of a private type's
2325 -- full view at the end of the private declarations to catch
2326 -- potential errors.
2328 elsif Decls = Private_Declarations (Context)
2329 and then not Is_Private_Type (Typ)
2330 and then Has_Private_Declaration (Typ)
2331 and then Has_Invariants (Typ)
2332 then
2333 Build_Invariant_Procedure_Body (Typ);
2334 end if;
2335 end if;
2336 end Build_Assertion_Bodies_For_Type;
2338 -- Local variables
2340 Decl : Node_Id;
2341 Decl_Id : Entity_Id;
2343 -- Start of processing for Build_Assertion_Bodies
2345 begin
2346 Decl := First (Decls);
2347 while Present (Decl) loop
2348 if Is_Declaration (Decl) then
2349 Decl_Id := Defining_Entity (Decl);
2351 if Is_Type (Decl_Id) then
2352 Build_Assertion_Bodies_For_Type (Decl_Id);
2353 end if;
2354 end if;
2356 Next (Decl);
2357 end loop;
2358 end Build_Assertion_Bodies;
2360 ---------------------------
2361 -- Check_Entry_Contracts --
2362 ---------------------------
2364 procedure Check_Entry_Contracts is
2365 ASN : Node_Id;
2366 Ent : Entity_Id;
2367 Exp : Node_Id;
2369 begin
2370 Ent := First_Entity (Current_Scope);
2371 while Present (Ent) loop
2373 -- This only concerns entries with pre/postconditions
2375 if Ekind (Ent) = E_Entry
2376 and then Present (Contract (Ent))
2377 and then Present (Pre_Post_Conditions (Contract (Ent)))
2378 then
2379 ASN := Pre_Post_Conditions (Contract (Ent));
2380 Push_Scope (Ent);
2381 Install_Formals (Ent);
2383 -- Pre/postconditions are rewritten as Check pragmas. Analysis
2384 -- is performed on a copy of the pragma expression, to prevent
2385 -- modifying the original expression.
2387 while Present (ASN) loop
2388 if Nkind (ASN) = N_Pragma then
2389 Exp :=
2390 New_Copy_Tree
2391 (Expression
2392 (First (Pragma_Argument_Associations (ASN))));
2393 Set_Parent (Exp, ASN);
2395 Preanalyze_Assert_Expression (Exp, Standard_Boolean);
2396 end if;
2398 ASN := Next_Pragma (ASN);
2399 end loop;
2401 End_Scope;
2402 end if;
2404 Next_Entity (Ent);
2405 end loop;
2406 end Check_Entry_Contracts;
2408 ----------------------------------
2409 -- Contains_Lib_Incomplete_Type --
2410 ----------------------------------
2412 function Contains_Lib_Incomplete_Type (Pkg : Entity_Id) return Boolean is
2413 Curr : Entity_Id;
2415 begin
2416 -- Avoid looking through scopes that do not meet the precondition of
2417 -- Pkg not being within a library unit spec.
2419 if not Is_Compilation_Unit (Pkg)
2420 and then not Is_Generic_Instance (Pkg)
2421 and then not In_Package_Body (Enclosing_Lib_Unit_Entity (Pkg))
2422 then
2423 -- Loop through all entities in the current scope to identify
2424 -- an entity that depends on a private type.
2426 Curr := First_Entity (Pkg);
2427 loop
2428 if Nkind (Curr) in N_Entity
2429 and then Depends_On_Private (Curr)
2430 then
2431 return True;
2432 end if;
2434 exit when Last_Entity (Current_Scope) = Curr;
2435 Curr := Next_Entity (Curr);
2436 end loop;
2437 end if;
2439 return False;
2440 end Contains_Lib_Incomplete_Type;
2442 --------------------------------------
2443 -- Handle_Late_Controlled_Primitive --
2444 --------------------------------------
2446 procedure Handle_Late_Controlled_Primitive (Body_Decl : Node_Id) is
2447 Body_Spec : constant Node_Id := Specification (Body_Decl);
2448 Body_Id : constant Entity_Id := Defining_Entity (Body_Spec);
2449 Loc : constant Source_Ptr := Sloc (Body_Id);
2450 Params : constant List_Id :=
2451 Parameter_Specifications (Body_Spec);
2452 Spec : Node_Id;
2453 Spec_Id : Entity_Id;
2454 Typ : Node_Id;
2456 begin
2457 -- Consider only procedure bodies whose name matches one of the three
2458 -- controlled primitives.
2460 if Nkind (Body_Spec) /= N_Procedure_Specification
2461 or else not Nam_In (Chars (Body_Id), Name_Adjust,
2462 Name_Finalize,
2463 Name_Initialize)
2464 then
2465 return;
2467 -- A controlled primitive must have exactly one formal which is not
2468 -- an anonymous access type.
2470 elsif List_Length (Params) /= 1 then
2471 return;
2472 end if;
2474 Typ := Parameter_Type (First (Params));
2476 if Nkind (Typ) = N_Access_Definition then
2477 return;
2478 end if;
2480 Find_Type (Typ);
2482 -- The type of the formal must be derived from [Limited_]Controlled
2484 if not Is_Controlled (Entity (Typ)) then
2485 return;
2486 end if;
2488 -- Check whether a specification exists for this body. We do not
2489 -- analyze the spec of the body in full, because it will be analyzed
2490 -- again when the body is properly analyzed, and we cannot create
2491 -- duplicate entries in the formals chain. We look for an explicit
2492 -- specification because the body may be an overriding operation and
2493 -- an inherited spec may be present.
2495 Spec_Id := Current_Entity (Body_Id);
2497 while Present (Spec_Id) loop
2498 if Ekind_In (Spec_Id, E_Procedure, E_Generic_Procedure)
2499 and then Scope (Spec_Id) = Current_Scope
2500 and then Present (First_Formal (Spec_Id))
2501 and then No (Next_Formal (First_Formal (Spec_Id)))
2502 and then Etype (First_Formal (Spec_Id)) = Entity (Typ)
2503 and then Comes_From_Source (Spec_Id)
2504 then
2505 return;
2506 end if;
2508 Spec_Id := Homonym (Spec_Id);
2509 end loop;
2511 -- At this point the body is known to be a late controlled primitive.
2512 -- Generate a matching spec and insert it before the body. Note the
2513 -- use of Copy_Separate_Tree - we want an entirely separate semantic
2514 -- tree in this case.
2516 Spec := Copy_Separate_Tree (Body_Spec);
2518 -- Ensure that the subprogram declaration does not inherit the null
2519 -- indicator from the body as we now have a proper spec/body pair.
2521 Set_Null_Present (Spec, False);
2523 -- Ensure that the freeze node is inserted after the declaration of
2524 -- the primitive since its expansion will freeze the primitive.
2526 Decl := Make_Subprogram_Declaration (Loc, Specification => Spec);
2528 Insert_Before_And_Analyze (Body_Decl, Decl);
2529 end Handle_Late_Controlled_Primitive;
2531 ----------------------------------------
2532 -- Remove_Partial_Visible_Refinements --
2533 ----------------------------------------
2535 procedure Remove_Partial_Visible_Refinements (Spec_Id : Entity_Id) is
2536 State_Elmt : Elmt_Id;
2537 begin
2538 if Present (Abstract_States (Spec_Id)) then
2539 State_Elmt := First_Elmt (Abstract_States (Spec_Id));
2540 while Present (State_Elmt) loop
2541 Set_Has_Partial_Visible_Refinement (Node (State_Elmt), False);
2542 Next_Elmt (State_Elmt);
2543 end loop;
2544 end if;
2546 -- For a child unit, also hide the partial state refinement from
2547 -- ancestor packages.
2549 if Is_Child_Unit (Spec_Id) then
2550 Remove_Partial_Visible_Refinements (Scope (Spec_Id));
2551 end if;
2552 end Remove_Partial_Visible_Refinements;
2554 --------------------------------
2555 -- Remove_Visible_Refinements --
2556 --------------------------------
2558 procedure Remove_Visible_Refinements (Spec_Id : Entity_Id) is
2559 State_Elmt : Elmt_Id;
2560 begin
2561 if Present (Abstract_States (Spec_Id)) then
2562 State_Elmt := First_Elmt (Abstract_States (Spec_Id));
2563 while Present (State_Elmt) loop
2564 Set_Has_Visible_Refinement (Node (State_Elmt), False);
2565 Next_Elmt (State_Elmt);
2566 end loop;
2567 end if;
2568 end Remove_Visible_Refinements;
2570 ---------------------
2571 -- Resolve_Aspects --
2572 ---------------------
2574 procedure Resolve_Aspects is
2575 E : Entity_Id;
2577 begin
2578 E := First_Entity (Current_Scope);
2579 while Present (E) loop
2580 Resolve_Aspect_Expressions (E);
2581 Next_Entity (E);
2582 end loop;
2583 end Resolve_Aspects;
2585 -- Local variables
2587 Context : Node_Id := Empty;
2588 Freeze_From : Entity_Id := Empty;
2589 Next_Decl : Node_Id;
2591 Body_Seen : Boolean := False;
2592 -- Flag set when the first body [stub] is encountered
2594 -- Start of processing for Analyze_Declarations
2596 begin
2597 if Restriction_Check_Required (SPARK_05) then
2598 Check_Later_Vs_Basic_Declarations (L, During_Parsing => False);
2599 end if;
2601 Decl := First (L);
2602 while Present (Decl) loop
2604 -- Package spec cannot contain a package declaration in SPARK
2606 if Nkind (Decl) = N_Package_Declaration
2607 and then Nkind (Parent (L)) = N_Package_Specification
2608 then
2609 Check_SPARK_05_Restriction
2610 ("package specification cannot contain a package declaration",
2611 Decl);
2612 end if;
2614 -- Complete analysis of declaration
2616 Analyze (Decl);
2617 Next_Decl := Next (Decl);
2619 if No (Freeze_From) then
2620 Freeze_From := First_Entity (Current_Scope);
2621 end if;
2623 -- At the end of a declarative part, freeze remaining entities
2624 -- declared in it. The end of the visible declarations of package
2625 -- specification is not the end of a declarative part if private
2626 -- declarations are present. The end of a package declaration is a
2627 -- freezing point only if it a library package. A task definition or
2628 -- protected type definition is not a freeze point either. Finally,
2629 -- we do not freeze entities in generic scopes, because there is no
2630 -- code generated for them and freeze nodes will be generated for
2631 -- the instance.
2633 -- The end of a package instantiation is not a freeze point, but
2634 -- for now we make it one, because the generic body is inserted
2635 -- (currently) immediately after. Generic instantiations will not
2636 -- be a freeze point once delayed freezing of bodies is implemented.
2637 -- (This is needed in any case for early instantiations ???).
2639 if No (Next_Decl) then
2640 if Nkind (Parent (L)) = N_Component_List then
2641 null;
2643 elsif Nkind_In (Parent (L), N_Protected_Definition,
2644 N_Task_Definition)
2645 then
2646 Check_Entry_Contracts;
2648 elsif Nkind (Parent (L)) /= N_Package_Specification then
2649 if Nkind (Parent (L)) = N_Package_Body then
2650 Freeze_From := First_Entity (Current_Scope);
2651 end if;
2653 -- There may have been several freezing points previously,
2654 -- for example object declarations or subprogram bodies, but
2655 -- at the end of a declarative part we check freezing from
2656 -- the beginning, even though entities may already be frozen,
2657 -- in order to perform visibility checks on delayed aspects.
2659 Adjust_Decl;
2661 -- If the current scope is a generic subprogram body. Skip the
2662 -- generic formal parameters that are not frozen here.
2664 if Is_Subprogram (Current_Scope)
2665 and then Nkind (Unit_Declaration_Node (Current_Scope)) =
2666 N_Generic_Subprogram_Declaration
2667 and then Present (First_Entity (Current_Scope))
2668 then
2669 while Is_Generic_Formal (Freeze_From) loop
2670 Freeze_From := Next_Entity (Freeze_From);
2671 end loop;
2673 Freeze_All (Freeze_From, Decl);
2674 Freeze_From := Last_Entity (Current_Scope);
2676 else
2677 -- For declarations in a subprogram body there is no issue
2678 -- with name resolution in aspect specifications, but in
2679 -- ASIS mode we need to preanalyze aspect specifications
2680 -- that may otherwise only be analyzed during expansion
2681 -- (e.g. during generation of a related subprogram).
2683 if ASIS_Mode then
2684 Resolve_Aspects;
2685 end if;
2687 Freeze_All (First_Entity (Current_Scope), Decl);
2688 Freeze_From := Last_Entity (Current_Scope);
2689 end if;
2691 -- Current scope is a package specification
2693 elsif Scope (Current_Scope) /= Standard_Standard
2694 and then not Is_Child_Unit (Current_Scope)
2695 and then No (Generic_Parent (Parent (L)))
2696 then
2697 -- ARM rule 13.1.1(11/3): usage names in aspect definitions are
2698 -- resolved at the end of the immediately enclosing declaration
2699 -- list (AI05-0183-1).
2701 Resolve_Aspects;
2703 elsif L /= Visible_Declarations (Parent (L))
2704 or else No (Private_Declarations (Parent (L)))
2705 or else Is_Empty_List (Private_Declarations (Parent (L)))
2706 then
2707 Adjust_Decl;
2709 -- End of a package declaration
2711 -- In compilation mode the expansion of freeze node takes care
2712 -- of resolving expressions of all aspects in the list. In ASIS
2713 -- mode this must be done explicitly.
2715 if ASIS_Mode
2716 and then Scope (Current_Scope) = Standard_Standard
2717 then
2718 Resolve_Aspects;
2719 end if;
2721 -- This is a freeze point because it is the end of a
2722 -- compilation unit.
2724 Freeze_All (First_Entity (Current_Scope), Decl);
2725 Freeze_From := Last_Entity (Current_Scope);
2727 -- At the end of the visible declarations the expressions in
2728 -- aspects of all entities declared so far must be resolved.
2729 -- The entities themselves might be frozen later, and the
2730 -- generated pragmas and attribute definition clauses analyzed
2731 -- in full at that point, but name resolution must take place
2732 -- now.
2733 -- In addition to being the proper semantics, this is mandatory
2734 -- within generic units, because global name capture requires
2735 -- those expressions to be analyzed, given that the generated
2736 -- pragmas do not appear in the original generic tree.
2738 elsif Serious_Errors_Detected = 0 then
2739 Resolve_Aspects;
2740 end if;
2742 -- If next node is a body then freeze all types before the body.
2743 -- An exception occurs for some expander-generated bodies. If these
2744 -- are generated at places where in general language rules would not
2745 -- allow a freeze point, then we assume that the expander has
2746 -- explicitly checked that all required types are properly frozen,
2747 -- and we do not cause general freezing here. This special circuit
2748 -- is used when the encountered body is marked as having already
2749 -- been analyzed.
2751 -- In all other cases (bodies that come from source, and expander
2752 -- generated bodies that have not been analyzed yet), freeze all
2753 -- types now. Note that in the latter case, the expander must take
2754 -- care to attach the bodies at a proper place in the tree so as to
2755 -- not cause unwanted freezing at that point.
2757 -- It is also necessary to check for a case where both an expression
2758 -- function is used and the current scope depends on an incomplete
2759 -- private type from a library unit, otherwise premature freezing of
2760 -- the private type will occur.
2762 elsif not Analyzed (Next_Decl) and then Is_Body (Next_Decl)
2763 and then ((Nkind (Next_Decl) /= N_Subprogram_Body
2764 or else not Was_Expression_Function (Next_Decl))
2765 or else (not Is_Ignored_Ghost_Entity (Current_Scope)
2766 and then not Contains_Lib_Incomplete_Type
2767 (Current_Scope)))
2768 then
2769 -- When a controlled type is frozen, the expander generates stream
2770 -- and controlled-type support routines. If the freeze is caused
2771 -- by the stand-alone body of Initialize, Adjust, or Finalize, the
2772 -- expander will end up using the wrong version of these routines,
2773 -- as the body has not been processed yet. To remedy this, detect
2774 -- a late controlled primitive and create a proper spec for it.
2775 -- This ensures that the primitive will override its inherited
2776 -- counterpart before the freeze takes place.
2778 -- If the declaration we just processed is a body, do not attempt
2779 -- to examine Next_Decl as the late primitive idiom can only apply
2780 -- to the first encountered body.
2782 -- The spec of the late primitive is not generated in ASIS mode to
2783 -- ensure a consistent list of primitives that indicates the true
2784 -- semantic structure of the program (which is not relevant when
2785 -- generating executable code).
2787 -- ??? A cleaner approach may be possible and/or this solution
2788 -- could be extended to general-purpose late primitives, TBD.
2790 if not ASIS_Mode
2791 and then not Body_Seen
2792 and then not Is_Body (Decl)
2793 then
2794 Body_Seen := True;
2796 if Nkind (Next_Decl) = N_Subprogram_Body then
2797 Handle_Late_Controlled_Primitive (Next_Decl);
2798 end if;
2800 else
2801 -- In ASIS mode, if the next declaration is a body, complete
2802 -- the analysis of declarations so far.
2804 Resolve_Aspects;
2805 end if;
2807 Adjust_Decl;
2809 -- The generated body of an expression function does not freeze,
2810 -- unless it is a completion, in which case only the expression
2811 -- itself freezes. This is handled when the body itself is
2812 -- analyzed (see Freeze_Expr_Types, sem_ch6.adb).
2814 Freeze_All (Freeze_From, Decl);
2815 Freeze_From := Last_Entity (Current_Scope);
2816 end if;
2818 Decl := Next_Decl;
2819 end loop;
2821 -- Post-freezing actions
2823 if Present (L) then
2824 Context := Parent (L);
2826 -- Certain contract annocations have forward visibility semantics and
2827 -- must be analyzed after all declarative items have been processed.
2828 -- This timing ensures that entities referenced by such contracts are
2829 -- visible.
2831 -- Analyze the contract of an immediately enclosing package spec or
2832 -- body first because other contracts may depend on its information.
2834 if Nkind (Context) = N_Package_Body then
2835 Analyze_Package_Body_Contract (Defining_Entity (Context));
2837 elsif Nkind (Context) = N_Package_Specification then
2838 Analyze_Package_Contract (Defining_Entity (Context));
2839 end if;
2841 -- Analyze the contracts of various constructs in the declarative
2842 -- list.
2844 Analyze_Contracts (L);
2846 if Nkind (Context) = N_Package_Body then
2848 -- Ensure that all abstract states and objects declared in the
2849 -- state space of a package body are utilized as constituents.
2851 Check_Unused_Body_States (Defining_Entity (Context));
2853 -- State refinements are visible up to the end of the package body
2854 -- declarations. Hide the state refinements from visibility to
2855 -- restore the original state conditions.
2857 Remove_Visible_Refinements (Corresponding_Spec (Context));
2858 Remove_Partial_Visible_Refinements (Corresponding_Spec (Context));
2860 elsif Nkind (Context) = N_Package_Specification then
2862 -- Partial state refinements are visible up to the end of the
2863 -- package spec declarations. Hide the partial state refinements
2864 -- from visibility to restore the original state conditions.
2866 Remove_Partial_Visible_Refinements (Defining_Entity (Context));
2867 end if;
2869 -- Verify that all abstract states found in any package declared in
2870 -- the input declarative list have proper refinements. The check is
2871 -- performed only when the context denotes a block, entry, package,
2872 -- protected, subprogram, or task body (SPARK RM 7.2.2(3)).
2874 Check_State_Refinements (Context);
2876 -- Create the subprogram bodies which verify the run-time semantics
2877 -- of pragmas Default_Initial_Condition and [Type_]Invariant for all
2878 -- types within the current declarative list. This ensures that all
2879 -- assertion expressions are preanalyzed and resolved at the end of
2880 -- the declarative part. Note that the resolution happens even when
2881 -- freezing does not take place.
2883 Build_Assertion_Bodies (L, Context);
2884 end if;
2885 end Analyze_Declarations;
2887 -----------------------------------
2888 -- Analyze_Full_Type_Declaration --
2889 -----------------------------------
2891 procedure Analyze_Full_Type_Declaration (N : Node_Id) is
2892 Def : constant Node_Id := Type_Definition (N);
2893 Def_Id : constant Entity_Id := Defining_Identifier (N);
2894 T : Entity_Id;
2895 Prev : Entity_Id;
2897 Is_Remote : constant Boolean :=
2898 (Is_Remote_Types (Current_Scope)
2899 or else Is_Remote_Call_Interface (Current_Scope))
2900 and then not (In_Private_Part (Current_Scope)
2901 or else In_Package_Body (Current_Scope));
2903 procedure Check_Nonoverridable_Aspects;
2904 -- Apply the rule in RM 13.1.1(18.4/4) on iterator aspects that cannot
2905 -- be overridden, and can only be confirmed on derivation.
2907 procedure Check_Ops_From_Incomplete_Type;
2908 -- If there is a tagged incomplete partial view of the type, traverse
2909 -- the primitives of the incomplete view and change the type of any
2910 -- controlling formals and result to indicate the full view. The
2911 -- primitives will be added to the full type's primitive operations
2912 -- list later in Sem_Disp.Check_Operation_From_Incomplete_Type (which
2913 -- is called from Process_Incomplete_Dependents).
2915 ----------------------------------
2916 -- Check_Nonoverridable_Aspects --
2917 ----------------------------------
2919 procedure Check_Nonoverridable_Aspects is
2920 function Get_Aspect_Spec
2921 (Specs : List_Id;
2922 Aspect_Name : Name_Id) return Node_Id;
2923 -- Check whether a list of aspect specifications includes an entry
2924 -- for a specific aspect. The list is either that of a partial or
2925 -- a full view.
2927 ---------------------
2928 -- Get_Aspect_Spec --
2929 ---------------------
2931 function Get_Aspect_Spec
2932 (Specs : List_Id;
2933 Aspect_Name : Name_Id) return Node_Id
2935 Spec : Node_Id;
2937 begin
2938 Spec := First (Specs);
2939 while Present (Spec) loop
2940 if Chars (Identifier (Spec)) = Aspect_Name then
2941 return Spec;
2942 end if;
2943 Next (Spec);
2944 end loop;
2946 return Empty;
2947 end Get_Aspect_Spec;
2949 -- Local variables
2951 Prev_Aspects : constant List_Id :=
2952 Aspect_Specifications (Parent (Def_Id));
2953 Par_Type : Entity_Id;
2954 Prev_Aspect : Node_Id;
2956 -- Start of processing for Check_Nonoverridable_Aspects
2958 begin
2959 -- Get parent type of derived type. Note that Prev is the entity in
2960 -- the partial declaration, but its contents are now those of full
2961 -- view, while Def_Id reflects the partial view.
2963 if Is_Private_Type (Def_Id) then
2964 Par_Type := Etype (Full_View (Def_Id));
2965 else
2966 Par_Type := Etype (Def_Id);
2967 end if;
2969 -- If there is an inherited Implicit_Dereference, verify that it is
2970 -- made explicit in the partial view.
2972 if Has_Discriminants (Base_Type (Par_Type))
2973 and then Nkind (Parent (Prev)) = N_Full_Type_Declaration
2974 and then Present (Discriminant_Specifications (Parent (Prev)))
2975 and then Present (Get_Reference_Discriminant (Par_Type))
2976 then
2977 Prev_Aspect :=
2978 Get_Aspect_Spec (Prev_Aspects, Name_Implicit_Dereference);
2980 if No (Prev_Aspect)
2981 and then Present
2982 (Discriminant_Specifications
2983 (Original_Node (Parent (Prev))))
2984 then
2985 Error_Msg_N
2986 ("type does not inherit implicit dereference", Prev);
2988 else
2989 -- If one of the views has the aspect specified, verify that it
2990 -- is consistent with that of the parent.
2992 declare
2993 Par_Discr : constant Entity_Id :=
2994 Get_Reference_Discriminant (Par_Type);
2995 Cur_Discr : constant Entity_Id :=
2996 Get_Reference_Discriminant (Prev);
2998 begin
2999 if Corresponding_Discriminant (Cur_Discr) /= Par_Discr then
3000 Error_Msg_N ("aspect incosistent with that of parent", N);
3001 end if;
3003 -- Check that specification in partial view matches the
3004 -- inherited aspect. Compare names directly because aspect
3005 -- expression may not be analyzed.
3007 if Present (Prev_Aspect)
3008 and then Nkind (Expression (Prev_Aspect)) = N_Identifier
3009 and then Chars (Expression (Prev_Aspect)) /=
3010 Chars (Cur_Discr)
3011 then
3012 Error_Msg_N
3013 ("aspect incosistent with that of parent", N);
3014 end if;
3015 end;
3016 end if;
3017 end if;
3019 -- TBD : other nonoverridable aspects.
3020 end Check_Nonoverridable_Aspects;
3022 ------------------------------------
3023 -- Check_Ops_From_Incomplete_Type --
3024 ------------------------------------
3026 procedure Check_Ops_From_Incomplete_Type is
3027 Elmt : Elmt_Id;
3028 Formal : Entity_Id;
3029 Op : Entity_Id;
3031 begin
3032 if Prev /= T
3033 and then Ekind (Prev) = E_Incomplete_Type
3034 and then Is_Tagged_Type (Prev)
3035 and then Is_Tagged_Type (T)
3036 then
3037 Elmt := First_Elmt (Primitive_Operations (Prev));
3038 while Present (Elmt) loop
3039 Op := Node (Elmt);
3041 Formal := First_Formal (Op);
3042 while Present (Formal) loop
3043 if Etype (Formal) = Prev then
3044 Set_Etype (Formal, T);
3045 end if;
3047 Next_Formal (Formal);
3048 end loop;
3050 if Etype (Op) = Prev then
3051 Set_Etype (Op, T);
3052 end if;
3054 Next_Elmt (Elmt);
3055 end loop;
3056 end if;
3057 end Check_Ops_From_Incomplete_Type;
3059 -- Start of processing for Analyze_Full_Type_Declaration
3061 begin
3062 Prev := Find_Type_Name (N);
3064 -- The full view, if present, now points to the current type. If there
3065 -- is an incomplete partial view, set a link to it, to simplify the
3066 -- retrieval of primitive operations of the type.
3068 -- Ada 2005 (AI-50217): If the type was previously decorated when
3069 -- imported through a LIMITED WITH clause, it appears as incomplete
3070 -- but has no full view.
3072 if Ekind (Prev) = E_Incomplete_Type
3073 and then Present (Full_View (Prev))
3074 then
3075 T := Full_View (Prev);
3076 Set_Incomplete_View (N, Parent (Prev));
3077 else
3078 T := Prev;
3079 end if;
3081 Set_Is_Pure (T, Is_Pure (Current_Scope));
3083 -- We set the flag Is_First_Subtype here. It is needed to set the
3084 -- corresponding flag for the Implicit class-wide-type created
3085 -- during tagged types processing.
3087 Set_Is_First_Subtype (T, True);
3089 -- Only composite types other than array types are allowed to have
3090 -- discriminants.
3092 case Nkind (Def) is
3094 -- For derived types, the rule will be checked once we've figured
3095 -- out the parent type.
3097 when N_Derived_Type_Definition =>
3098 null;
3100 -- For record types, discriminants are allowed, unless we are in
3101 -- SPARK.
3103 when N_Record_Definition =>
3104 if Present (Discriminant_Specifications (N)) then
3105 Check_SPARK_05_Restriction
3106 ("discriminant type is not allowed",
3107 Defining_Identifier
3108 (First (Discriminant_Specifications (N))));
3109 end if;
3111 when others =>
3112 if Present (Discriminant_Specifications (N)) then
3113 Error_Msg_N
3114 ("elementary or array type cannot have discriminants",
3115 Defining_Identifier
3116 (First (Discriminant_Specifications (N))));
3117 end if;
3118 end case;
3120 -- Elaborate the type definition according to kind, and generate
3121 -- subsidiary (implicit) subtypes where needed. We skip this if it was
3122 -- already done (this happens during the reanalysis that follows a call
3123 -- to the high level optimizer).
3125 if not Analyzed (T) then
3126 Set_Analyzed (T);
3128 -- Set the SPARK mode from the current context
3130 Set_SPARK_Pragma (T, SPARK_Mode_Pragma);
3131 Set_SPARK_Pragma_Inherited (T);
3133 case Nkind (Def) is
3134 when N_Access_To_Subprogram_Definition =>
3135 Access_Subprogram_Declaration (T, Def);
3137 -- If this is a remote access to subprogram, we must create the
3138 -- equivalent fat pointer type, and related subprograms.
3140 if Is_Remote then
3141 Process_Remote_AST_Declaration (N);
3142 end if;
3144 -- Validate categorization rule against access type declaration
3145 -- usually a violation in Pure unit, Shared_Passive unit.
3147 Validate_Access_Type_Declaration (T, N);
3149 when N_Access_To_Object_Definition =>
3150 Access_Type_Declaration (T, Def);
3152 -- Validate categorization rule against access type declaration
3153 -- usually a violation in Pure unit, Shared_Passive unit.
3155 Validate_Access_Type_Declaration (T, N);
3157 -- If we are in a Remote_Call_Interface package and define a
3158 -- RACW, then calling stubs and specific stream attributes
3159 -- must be added.
3161 if Is_Remote
3162 and then Is_Remote_Access_To_Class_Wide_Type (Def_Id)
3163 then
3164 Add_RACW_Features (Def_Id);
3165 end if;
3167 when N_Array_Type_Definition =>
3168 Array_Type_Declaration (T, Def);
3170 when N_Derived_Type_Definition =>
3171 Derived_Type_Declaration (T, N, T /= Def_Id);
3173 -- Inherit predicates from parent, and protect against illegal
3174 -- derivations.
3176 if Is_Type (T) and then Has_Predicates (T) then
3177 Set_Has_Predicates (Def_Id);
3178 end if;
3180 -- Save the scenario for examination by the ABE Processing
3181 -- phase.
3183 Record_Elaboration_Scenario (N);
3185 when N_Enumeration_Type_Definition =>
3186 Enumeration_Type_Declaration (T, Def);
3188 when N_Floating_Point_Definition =>
3189 Floating_Point_Type_Declaration (T, Def);
3191 when N_Decimal_Fixed_Point_Definition =>
3192 Decimal_Fixed_Point_Type_Declaration (T, Def);
3194 when N_Ordinary_Fixed_Point_Definition =>
3195 Ordinary_Fixed_Point_Type_Declaration (T, Def);
3197 when N_Signed_Integer_Type_Definition =>
3198 Signed_Integer_Type_Declaration (T, Def);
3200 when N_Modular_Type_Definition =>
3201 Modular_Type_Declaration (T, Def);
3203 when N_Record_Definition =>
3204 Record_Type_Declaration (T, N, Prev);
3206 -- If declaration has a parse error, nothing to elaborate.
3208 when N_Error =>
3209 null;
3211 when others =>
3212 raise Program_Error;
3213 end case;
3214 end if;
3216 if Etype (T) = Any_Type then
3217 return;
3218 end if;
3220 -- Controlled type is not allowed in SPARK
3222 if Is_Visibly_Controlled (T) then
3223 Check_SPARK_05_Restriction ("controlled type is not allowed", N);
3224 end if;
3226 -- Some common processing for all types
3228 Set_Depends_On_Private (T, Has_Private_Component (T));
3229 Check_Ops_From_Incomplete_Type;
3231 -- Both the declared entity, and its anonymous base type if one was
3232 -- created, need freeze nodes allocated.
3234 declare
3235 B : constant Entity_Id := Base_Type (T);
3237 begin
3238 -- In the case where the base type differs from the first subtype, we
3239 -- pre-allocate a freeze node, and set the proper link to the first
3240 -- subtype. Freeze_Entity will use this preallocated freeze node when
3241 -- it freezes the entity.
3243 -- This does not apply if the base type is a generic type, whose
3244 -- declaration is independent of the current derived definition.
3246 if B /= T and then not Is_Generic_Type (B) then
3247 Ensure_Freeze_Node (B);
3248 Set_First_Subtype_Link (Freeze_Node (B), T);
3249 end if;
3251 -- A type that is imported through a limited_with clause cannot
3252 -- generate any code, and thus need not be frozen. However, an access
3253 -- type with an imported designated type needs a finalization list,
3254 -- which may be referenced in some other package that has non-limited
3255 -- visibility on the designated type. Thus we must create the
3256 -- finalization list at the point the access type is frozen, to
3257 -- prevent unsatisfied references at link time.
3259 if not From_Limited_With (T) or else Is_Access_Type (T) then
3260 Set_Has_Delayed_Freeze (T);
3261 end if;
3262 end;
3264 -- Case where T is the full declaration of some private type which has
3265 -- been swapped in Defining_Identifier (N).
3267 if T /= Def_Id and then Is_Private_Type (Def_Id) then
3268 Process_Full_View (N, T, Def_Id);
3270 -- Record the reference. The form of this is a little strange, since
3271 -- the full declaration has been swapped in. So the first parameter
3272 -- here represents the entity to which a reference is made which is
3273 -- the "real" entity, i.e. the one swapped in, and the second
3274 -- parameter provides the reference location.
3276 -- Also, we want to kill Has_Pragma_Unreferenced temporarily here
3277 -- since we don't want a complaint about the full type being an
3278 -- unwanted reference to the private type
3280 declare
3281 B : constant Boolean := Has_Pragma_Unreferenced (T);
3282 begin
3283 Set_Has_Pragma_Unreferenced (T, False);
3284 Generate_Reference (T, T, 'c');
3285 Set_Has_Pragma_Unreferenced (T, B);
3286 end;
3288 Set_Completion_Referenced (Def_Id);
3290 -- For completion of incomplete type, process incomplete dependents
3291 -- and always mark the full type as referenced (it is the incomplete
3292 -- type that we get for any real reference).
3294 elsif Ekind (Prev) = E_Incomplete_Type then
3295 Process_Incomplete_Dependents (N, T, Prev);
3296 Generate_Reference (Prev, Def_Id, 'c');
3297 Set_Completion_Referenced (Def_Id);
3299 -- If not private type or incomplete type completion, this is a real
3300 -- definition of a new entity, so record it.
3302 else
3303 Generate_Definition (Def_Id);
3304 end if;
3306 -- Propagate any pending access types whose finalization masters need to
3307 -- be fully initialized from the partial to the full view. Guard against
3308 -- an illegal full view that remains unanalyzed.
3310 if Is_Type (Def_Id) and then Is_Incomplete_Or_Private_Type (Prev) then
3311 Set_Pending_Access_Types (Def_Id, Pending_Access_Types (Prev));
3312 end if;
3314 if Chars (Scope (Def_Id)) = Name_System
3315 and then Chars (Def_Id) = Name_Address
3316 and then In_Predefined_Unit (N)
3317 then
3318 Set_Is_Descendant_Of_Address (Def_Id);
3319 Set_Is_Descendant_Of_Address (Base_Type (Def_Id));
3320 Set_Is_Descendant_Of_Address (Prev);
3321 end if;
3323 Set_Optimize_Alignment_Flags (Def_Id);
3324 Check_Eliminated (Def_Id);
3326 -- If the declaration is a completion and aspects are present, apply
3327 -- them to the entity for the type which is currently the partial
3328 -- view, but which is the one that will be frozen.
3330 if Has_Aspects (N) then
3332 -- In most cases the partial view is a private type, and both views
3333 -- appear in different declarative parts. In the unusual case where
3334 -- the partial view is incomplete, perform the analysis on the
3335 -- full view, to prevent freezing anomalies with the corresponding
3336 -- class-wide type, which otherwise might be frozen before the
3337 -- dispatch table is built.
3339 if Prev /= Def_Id
3340 and then Ekind (Prev) /= E_Incomplete_Type
3341 then
3342 Analyze_Aspect_Specifications (N, Prev);
3344 -- Normal case
3346 else
3347 Analyze_Aspect_Specifications (N, Def_Id);
3348 end if;
3349 end if;
3351 if Is_Derived_Type (Prev)
3352 and then Def_Id /= Prev
3353 then
3354 Check_Nonoverridable_Aspects;
3355 end if;
3356 end Analyze_Full_Type_Declaration;
3358 ----------------------------------
3359 -- Analyze_Incomplete_Type_Decl --
3360 ----------------------------------
3362 procedure Analyze_Incomplete_Type_Decl (N : Node_Id) is
3363 F : constant Boolean := Is_Pure (Current_Scope);
3364 T : Entity_Id;
3366 begin
3367 Check_SPARK_05_Restriction ("incomplete type is not allowed", N);
3369 Generate_Definition (Defining_Identifier (N));
3371 -- Process an incomplete declaration. The identifier must not have been
3372 -- declared already in the scope. However, an incomplete declaration may
3373 -- appear in the private part of a package, for a private type that has
3374 -- already been declared.
3376 -- In this case, the discriminants (if any) must match
3378 T := Find_Type_Name (N);
3380 Set_Ekind (T, E_Incomplete_Type);
3381 Set_Etype (T, T);
3382 Set_Is_First_Subtype (T);
3383 Init_Size_Align (T);
3385 -- Set the SPARK mode from the current context
3387 Set_SPARK_Pragma (T, SPARK_Mode_Pragma);
3388 Set_SPARK_Pragma_Inherited (T);
3390 -- Ada 2005 (AI-326): Minimum decoration to give support to tagged
3391 -- incomplete types.
3393 if Tagged_Present (N) then
3394 Set_Is_Tagged_Type (T, True);
3395 Set_No_Tagged_Streams_Pragma (T, No_Tagged_Streams);
3396 Make_Class_Wide_Type (T);
3397 Set_Direct_Primitive_Operations (T, New_Elmt_List);
3398 end if;
3400 Set_Stored_Constraint (T, No_Elist);
3402 if Present (Discriminant_Specifications (N)) then
3403 Push_Scope (T);
3404 Process_Discriminants (N);
3405 End_Scope;
3406 end if;
3408 -- If the type has discriminants, nontrivial subtypes may be declared
3409 -- before the full view of the type. The full views of those subtypes
3410 -- will be built after the full view of the type.
3412 Set_Private_Dependents (T, New_Elmt_List);
3413 Set_Is_Pure (T, F);
3414 end Analyze_Incomplete_Type_Decl;
3416 -----------------------------------
3417 -- Analyze_Interface_Declaration --
3418 -----------------------------------
3420 procedure Analyze_Interface_Declaration (T : Entity_Id; Def : Node_Id) is
3421 CW : constant Entity_Id := Class_Wide_Type (T);
3423 begin
3424 Set_Is_Tagged_Type (T);
3425 Set_No_Tagged_Streams_Pragma (T, No_Tagged_Streams);
3427 Set_Is_Limited_Record (T, Limited_Present (Def)
3428 or else Task_Present (Def)
3429 or else Protected_Present (Def)
3430 or else Synchronized_Present (Def));
3432 -- Type is abstract if full declaration carries keyword, or if previous
3433 -- partial view did.
3435 Set_Is_Abstract_Type (T);
3436 Set_Is_Interface (T);
3438 -- Type is a limited interface if it includes the keyword limited, task,
3439 -- protected, or synchronized.
3441 Set_Is_Limited_Interface
3442 (T, Limited_Present (Def)
3443 or else Protected_Present (Def)
3444 or else Synchronized_Present (Def)
3445 or else Task_Present (Def));
3447 Set_Interfaces (T, New_Elmt_List);
3448 Set_Direct_Primitive_Operations (T, New_Elmt_List);
3450 -- Complete the decoration of the class-wide entity if it was already
3451 -- built (i.e. during the creation of the limited view)
3453 if Present (CW) then
3454 Set_Is_Interface (CW);
3455 Set_Is_Limited_Interface (CW, Is_Limited_Interface (T));
3456 end if;
3458 -- Check runtime support for synchronized interfaces
3460 if (Is_Task_Interface (T)
3461 or else Is_Protected_Interface (T)
3462 or else Is_Synchronized_Interface (T))
3463 and then not RTE_Available (RE_Select_Specific_Data)
3464 then
3465 Error_Msg_CRT ("synchronized interfaces", T);
3466 end if;
3467 end Analyze_Interface_Declaration;
3469 -----------------------------
3470 -- Analyze_Itype_Reference --
3471 -----------------------------
3473 -- Nothing to do. This node is placed in the tree only for the benefit of
3474 -- back end processing, and has no effect on the semantic processing.
3476 procedure Analyze_Itype_Reference (N : Node_Id) is
3477 begin
3478 pragma Assert (Is_Itype (Itype (N)));
3479 null;
3480 end Analyze_Itype_Reference;
3482 --------------------------------
3483 -- Analyze_Number_Declaration --
3484 --------------------------------
3486 procedure Analyze_Number_Declaration (N : Node_Id) is
3487 E : constant Node_Id := Expression (N);
3488 Id : constant Entity_Id := Defining_Identifier (N);
3489 Index : Interp_Index;
3490 It : Interp;
3491 T : Entity_Id;
3493 begin
3494 Generate_Definition (Id);
3495 Enter_Name (Id);
3497 -- This is an optimization of a common case of an integer literal
3499 if Nkind (E) = N_Integer_Literal then
3500 Set_Is_Static_Expression (E, True);
3501 Set_Etype (E, Universal_Integer);
3503 Set_Etype (Id, Universal_Integer);
3504 Set_Ekind (Id, E_Named_Integer);
3505 Set_Is_Frozen (Id, True);
3506 return;
3507 end if;
3509 Set_Is_Pure (Id, Is_Pure (Current_Scope));
3511 -- Process expression, replacing error by integer zero, to avoid
3512 -- cascaded errors or aborts further along in the processing
3514 -- Replace Error by integer zero, which seems least likely to cause
3515 -- cascaded errors.
3517 if E = Error then
3518 Rewrite (E, Make_Integer_Literal (Sloc (E), Uint_0));
3519 Set_Error_Posted (E);
3520 end if;
3522 Analyze (E);
3524 -- Verify that the expression is static and numeric. If
3525 -- the expression is overloaded, we apply the preference
3526 -- rule that favors root numeric types.
3528 if not Is_Overloaded (E) then
3529 T := Etype (E);
3530 if Has_Dynamic_Predicate_Aspect (T) then
3531 Error_Msg_N
3532 ("subtype has dynamic predicate, "
3533 & "not allowed in number declaration", N);
3534 end if;
3536 else
3537 T := Any_Type;
3539 Get_First_Interp (E, Index, It);
3540 while Present (It.Typ) loop
3541 if (Is_Integer_Type (It.Typ) or else Is_Real_Type (It.Typ))
3542 and then (Scope (Base_Type (It.Typ))) = Standard_Standard
3543 then
3544 if T = Any_Type then
3545 T := It.Typ;
3547 elsif It.Typ = Universal_Real
3548 or else
3549 It.Typ = Universal_Integer
3550 then
3551 -- Choose universal interpretation over any other
3553 T := It.Typ;
3554 exit;
3555 end if;
3556 end if;
3558 Get_Next_Interp (Index, It);
3559 end loop;
3560 end if;
3562 if Is_Integer_Type (T) then
3563 Resolve (E, T);
3564 Set_Etype (Id, Universal_Integer);
3565 Set_Ekind (Id, E_Named_Integer);
3567 elsif Is_Real_Type (T) then
3569 -- Because the real value is converted to universal_real, this is a
3570 -- legal context for a universal fixed expression.
3572 if T = Universal_Fixed then
3573 declare
3574 Loc : constant Source_Ptr := Sloc (N);
3575 Conv : constant Node_Id := Make_Type_Conversion (Loc,
3576 Subtype_Mark =>
3577 New_Occurrence_Of (Universal_Real, Loc),
3578 Expression => Relocate_Node (E));
3580 begin
3581 Rewrite (E, Conv);
3582 Analyze (E);
3583 end;
3585 elsif T = Any_Fixed then
3586 Error_Msg_N ("illegal context for mixed mode operation", E);
3588 -- Expression is of the form : universal_fixed * integer. Try to
3589 -- resolve as universal_real.
3591 T := Universal_Real;
3592 Set_Etype (E, T);
3593 end if;
3595 Resolve (E, T);
3596 Set_Etype (Id, Universal_Real);
3597 Set_Ekind (Id, E_Named_Real);
3599 else
3600 Wrong_Type (E, Any_Numeric);
3601 Resolve (E, T);
3603 Set_Etype (Id, T);
3604 Set_Ekind (Id, E_Constant);
3605 Set_Never_Set_In_Source (Id, True);
3606 Set_Is_True_Constant (Id, True);
3607 return;
3608 end if;
3610 if Nkind_In (E, N_Integer_Literal, N_Real_Literal) then
3611 Set_Etype (E, Etype (Id));
3612 end if;
3614 if not Is_OK_Static_Expression (E) then
3615 Flag_Non_Static_Expr
3616 ("non-static expression used in number declaration!", E);
3617 Rewrite (E, Make_Integer_Literal (Sloc (N), 1));
3618 Set_Etype (E, Any_Type);
3619 end if;
3621 Analyze_Dimension (N);
3622 end Analyze_Number_Declaration;
3624 --------------------------------
3625 -- Analyze_Object_Declaration --
3626 --------------------------------
3628 -- WARNING: This routine manages Ghost regions. Return statements must be
3629 -- replaced by gotos which jump to the end of the routine and restore the
3630 -- Ghost mode.
3632 procedure Analyze_Object_Declaration (N : Node_Id) is
3633 Loc : constant Source_Ptr := Sloc (N);
3634 Id : constant Entity_Id := Defining_Identifier (N);
3635 Act_T : Entity_Id;
3636 T : Entity_Id;
3638 E : Node_Id := Expression (N);
3639 -- E is set to Expression (N) throughout this routine. When Expression
3640 -- (N) is modified, E is changed accordingly.
3642 Prev_Entity : Entity_Id := Empty;
3644 procedure Check_Dynamic_Object (Typ : Entity_Id);
3645 -- A library-level object with non-static discriminant constraints may
3646 -- require dynamic allocation. The declaration is illegal if the
3647 -- profile includes the restriction No_Implicit_Heap_Allocations.
3649 procedure Check_For_Null_Excluding_Components
3650 (Obj_Typ : Entity_Id;
3651 Obj_Decl : Node_Id);
3652 -- Verify that each null-excluding component of object declaration
3653 -- Obj_Decl carrying type Obj_Typ has explicit initialization. Emit
3654 -- a compile-time warning if this is not the case.
3656 function Count_Tasks (T : Entity_Id) return Uint;
3657 -- This function is called when a non-generic library level object of a
3658 -- task type is declared. Its function is to count the static number of
3659 -- tasks declared within the type (it is only called if Has_Task is set
3660 -- for T). As a side effect, if an array of tasks with non-static bounds
3661 -- or a variant record type is encountered, Check_Restriction is called
3662 -- indicating the count is unknown.
3664 function Delayed_Aspect_Present return Boolean;
3665 -- If the declaration has an expression that is an aggregate, and it
3666 -- has aspects that require delayed analysis, the resolution of the
3667 -- aggregate must be deferred to the freeze point of the objet. This
3668 -- special processing was created for address clauses, but it must
3669 -- also apply to Alignment. This must be done before the aspect
3670 -- specifications are analyzed because we must handle the aggregate
3671 -- before the analysis of the object declaration is complete.
3673 -- Any other relevant delayed aspects on object declarations ???
3675 --------------------------
3676 -- Check_Dynamic_Object --
3677 --------------------------
3679 procedure Check_Dynamic_Object (Typ : Entity_Id) is
3680 Comp : Entity_Id;
3681 Obj_Type : Entity_Id;
3683 begin
3684 Obj_Type := Typ;
3686 if Is_Private_Type (Obj_Type)
3687 and then Present (Full_View (Obj_Type))
3688 then
3689 Obj_Type := Full_View (Obj_Type);
3690 end if;
3692 if Known_Static_Esize (Obj_Type) then
3693 return;
3694 end if;
3696 if Restriction_Active (No_Implicit_Heap_Allocations)
3697 and then Expander_Active
3698 and then Has_Discriminants (Obj_Type)
3699 then
3700 Comp := First_Component (Obj_Type);
3701 while Present (Comp) loop
3702 if Known_Static_Esize (Etype (Comp))
3703 or else Size_Known_At_Compile_Time (Etype (Comp))
3704 then
3705 null;
3707 elsif not Discriminated_Size (Comp)
3708 and then Comes_From_Source (Comp)
3709 then
3710 Error_Msg_NE
3711 ("component& of non-static size will violate restriction "
3712 & "No_Implicit_Heap_Allocation?", N, Comp);
3714 elsif Is_Record_Type (Etype (Comp)) then
3715 Check_Dynamic_Object (Etype (Comp));
3716 end if;
3718 Next_Component (Comp);
3719 end loop;
3720 end if;
3721 end Check_Dynamic_Object;
3723 -----------------------------------------
3724 -- Check_For_Null_Excluding_Components --
3725 -----------------------------------------
3727 procedure Check_For_Null_Excluding_Components
3728 (Obj_Typ : Entity_Id;
3729 Obj_Decl : Node_Id)
3731 procedure Check_Component
3732 (Comp_Typ : Entity_Id;
3733 Comp_Decl : Node_Id := Empty;
3734 Array_Comp : Boolean := False);
3735 -- Apply a compile-time null-exclusion check on a component denoted
3736 -- by its declaration Comp_Decl and type Comp_Typ, and all of its
3737 -- subcomponents (if any).
3739 ---------------------
3740 -- Check_Component --
3741 ---------------------
3743 procedure Check_Component
3744 (Comp_Typ : Entity_Id;
3745 Comp_Decl : Node_Id := Empty;
3746 Array_Comp : Boolean := False)
3748 Comp : Entity_Id;
3749 T : Entity_Id;
3751 begin
3752 -- Do not consider internally-generated components or those that
3753 -- are already initialized.
3755 if Present (Comp_Decl)
3756 and then (not Comes_From_Source (Comp_Decl)
3757 or else Present (Expression (Comp_Decl)))
3758 then
3759 return;
3760 end if;
3762 if Is_Incomplete_Or_Private_Type (Comp_Typ)
3763 and then Present (Full_View (Comp_Typ))
3764 then
3765 T := Full_View (Comp_Typ);
3766 else
3767 T := Comp_Typ;
3768 end if;
3770 -- Verify a component of a null-excluding access type
3772 if Is_Access_Type (T)
3773 and then Can_Never_Be_Null (T)
3774 then
3775 if Comp_Decl = Obj_Decl then
3776 Null_Exclusion_Static_Checks
3777 (N => Obj_Decl,
3778 Comp => Empty,
3779 Array_Comp => Array_Comp);
3781 else
3782 Null_Exclusion_Static_Checks
3783 (N => Obj_Decl,
3784 Comp => Comp_Decl,
3785 Array_Comp => Array_Comp);
3786 end if;
3788 -- Check array components
3790 elsif Is_Array_Type (T) then
3792 -- There is no suitable component when the object is of an
3793 -- array type. However, a namable component may appear at some
3794 -- point during the recursive inspection, but not at the top
3795 -- level. At the top level just indicate array component case.
3797 if Comp_Decl = Obj_Decl then
3798 Check_Component (Component_Type (T), Array_Comp => True);
3799 else
3800 Check_Component (Component_Type (T), Comp_Decl);
3801 end if;
3803 -- Verify all components of type T
3805 -- Note: No checks are performed on types with discriminants due
3806 -- to complexities involving variants. ???
3808 elsif (Is_Concurrent_Type (T)
3809 or else Is_Incomplete_Or_Private_Type (T)
3810 or else Is_Record_Type (T))
3811 and then not Has_Discriminants (T)
3812 then
3813 Comp := First_Component (T);
3814 while Present (Comp) loop
3815 Check_Component (Etype (Comp), Parent (Comp));
3817 Comp := Next_Component (Comp);
3818 end loop;
3819 end if;
3820 end Check_Component;
3822 -- Start processing for Check_For_Null_Excluding_Components
3824 begin
3825 Check_Component (Obj_Typ, Obj_Decl);
3826 end Check_For_Null_Excluding_Components;
3828 -----------------
3829 -- Count_Tasks --
3830 -----------------
3832 function Count_Tasks (T : Entity_Id) return Uint is
3833 C : Entity_Id;
3834 X : Node_Id;
3835 V : Uint;
3837 begin
3838 if Is_Task_Type (T) then
3839 return Uint_1;
3841 elsif Is_Record_Type (T) then
3842 if Has_Discriminants (T) then
3843 Check_Restriction (Max_Tasks, N);
3844 return Uint_0;
3846 else
3847 V := Uint_0;
3848 C := First_Component (T);
3849 while Present (C) loop
3850 V := V + Count_Tasks (Etype (C));
3851 Next_Component (C);
3852 end loop;
3854 return V;
3855 end if;
3857 elsif Is_Array_Type (T) then
3858 X := First_Index (T);
3859 V := Count_Tasks (Component_Type (T));
3860 while Present (X) loop
3861 C := Etype (X);
3863 if not Is_OK_Static_Subtype (C) then
3864 Check_Restriction (Max_Tasks, N);
3865 return Uint_0;
3866 else
3867 V := V * (UI_Max (Uint_0,
3868 Expr_Value (Type_High_Bound (C)) -
3869 Expr_Value (Type_Low_Bound (C)) + Uint_1));
3870 end if;
3872 Next_Index (X);
3873 end loop;
3875 return V;
3877 else
3878 return Uint_0;
3879 end if;
3880 end Count_Tasks;
3882 ----------------------------
3883 -- Delayed_Aspect_Present --
3884 ----------------------------
3886 function Delayed_Aspect_Present return Boolean is
3887 A : Node_Id;
3888 A_Id : Aspect_Id;
3890 begin
3891 if Present (Aspect_Specifications (N)) then
3892 A := First (Aspect_Specifications (N));
3893 A_Id := Get_Aspect_Id (Chars (Identifier (A)));
3894 while Present (A) loop
3895 if A_Id = Aspect_Alignment or else A_Id = Aspect_Address then
3896 return True;
3897 end if;
3899 Next (A);
3900 end loop;
3901 end if;
3903 return False;
3904 end Delayed_Aspect_Present;
3906 -- Local variables
3908 Saved_GM : constant Ghost_Mode_Type := Ghost_Mode;
3909 -- Save the Ghost mode to restore on exit
3911 Related_Id : Entity_Id;
3913 -- Start of processing for Analyze_Object_Declaration
3915 begin
3916 -- There are three kinds of implicit types generated by an
3917 -- object declaration:
3919 -- 1. Those generated by the original Object Definition
3921 -- 2. Those generated by the Expression
3923 -- 3. Those used to constrain the Object Definition with the
3924 -- expression constraints when the definition is unconstrained.
3926 -- They must be generated in this order to avoid order of elaboration
3927 -- issues. Thus the first step (after entering the name) is to analyze
3928 -- the object definition.
3930 if Constant_Present (N) then
3931 Prev_Entity := Current_Entity_In_Scope (Id);
3933 if Present (Prev_Entity)
3934 and then
3935 -- If the homograph is an implicit subprogram, it is overridden
3936 -- by the current declaration.
3938 ((Is_Overloadable (Prev_Entity)
3939 and then Is_Inherited_Operation (Prev_Entity))
3941 -- The current object is a discriminal generated for an entry
3942 -- family index. Even though the index is a constant, in this
3943 -- particular context there is no true constant redeclaration.
3944 -- Enter_Name will handle the visibility.
3946 or else
3947 (Is_Discriminal (Id)
3948 and then Ekind (Discriminal_Link (Id)) =
3949 E_Entry_Index_Parameter)
3951 -- The current object is the renaming for a generic declared
3952 -- within the instance.
3954 or else
3955 (Ekind (Prev_Entity) = E_Package
3956 and then Nkind (Parent (Prev_Entity)) =
3957 N_Package_Renaming_Declaration
3958 and then not Comes_From_Source (Prev_Entity)
3959 and then
3960 Is_Generic_Instance (Renamed_Entity (Prev_Entity)))
3962 -- The entity may be a homonym of a private component of the
3963 -- enclosing protected object, for which we create a local
3964 -- renaming declaration. The declaration is legal, even if
3965 -- useless when it just captures that component.
3967 or else
3968 (Ekind (Scope (Current_Scope)) = E_Protected_Type
3969 and then Nkind (Parent (Prev_Entity)) =
3970 N_Object_Renaming_Declaration))
3971 then
3972 Prev_Entity := Empty;
3973 end if;
3974 end if;
3976 if Present (Prev_Entity) then
3978 -- The object declaration is Ghost when it completes a deferred Ghost
3979 -- constant.
3981 Mark_And_Set_Ghost_Completion (N, Prev_Entity);
3983 Constant_Redeclaration (Id, N, T);
3985 Generate_Reference (Prev_Entity, Id, 'c');
3986 Set_Completion_Referenced (Id);
3988 if Error_Posted (N) then
3990 -- Type mismatch or illegal redeclaration; do not analyze
3991 -- expression to avoid cascaded errors.
3993 T := Find_Type_Of_Object (Object_Definition (N), N);
3994 Set_Etype (Id, T);
3995 Set_Ekind (Id, E_Variable);
3996 goto Leave;
3997 end if;
3999 -- In the normal case, enter identifier at the start to catch premature
4000 -- usage in the initialization expression.
4002 else
4003 Generate_Definition (Id);
4004 Enter_Name (Id);
4006 Mark_Coextensions (N, Object_Definition (N));
4008 T := Find_Type_Of_Object (Object_Definition (N), N);
4010 if Nkind (Object_Definition (N)) = N_Access_Definition
4011 and then Present
4012 (Access_To_Subprogram_Definition (Object_Definition (N)))
4013 and then Protected_Present
4014 (Access_To_Subprogram_Definition (Object_Definition (N)))
4015 then
4016 T := Replace_Anonymous_Access_To_Protected_Subprogram (N);
4017 end if;
4019 if Error_Posted (Id) then
4020 Set_Etype (Id, T);
4021 Set_Ekind (Id, E_Variable);
4022 goto Leave;
4023 end if;
4024 end if;
4026 -- Ada 2005 (AI-231): Propagate the null-excluding attribute and carry
4027 -- out some static checks.
4029 if Ada_Version >= Ada_2005 then
4031 -- In case of aggregates we must also take care of the correct
4032 -- initialization of nested aggregates bug this is done at the
4033 -- point of the analysis of the aggregate (see sem_aggr.adb) ???
4035 if Can_Never_Be_Null (T) then
4036 if Present (Expression (N))
4037 and then Nkind (Expression (N)) = N_Aggregate
4038 then
4039 null;
4041 else
4042 declare
4043 Save_Typ : constant Entity_Id := Etype (Id);
4044 begin
4045 Set_Etype (Id, T); -- Temp. decoration for static checks
4046 Null_Exclusion_Static_Checks (N);
4047 Set_Etype (Id, Save_Typ);
4048 end;
4049 end if;
4051 -- We might be dealing with an object of a composite type containing
4052 -- null-excluding components without an aggregate, so we must verify
4053 -- that such components have default initialization.
4055 else
4056 Check_For_Null_Excluding_Components (T, N);
4057 end if;
4058 end if;
4060 -- Object is marked pure if it is in a pure scope
4062 Set_Is_Pure (Id, Is_Pure (Current_Scope));
4064 -- If deferred constant, make sure context is appropriate. We detect
4065 -- a deferred constant as a constant declaration with no expression.
4066 -- A deferred constant can appear in a package body if its completion
4067 -- is by means of an interface pragma.
4069 if Constant_Present (N) and then No (E) then
4071 -- A deferred constant may appear in the declarative part of the
4072 -- following constructs:
4074 -- blocks
4075 -- entry bodies
4076 -- extended return statements
4077 -- package specs
4078 -- package bodies
4079 -- subprogram bodies
4080 -- task bodies
4082 -- When declared inside a package spec, a deferred constant must be
4083 -- completed by a full constant declaration or pragma Import. In all
4084 -- other cases, the only proper completion is pragma Import. Extended
4085 -- return statements are flagged as invalid contexts because they do
4086 -- not have a declarative part and so cannot accommodate the pragma.
4088 if Ekind (Current_Scope) = E_Return_Statement then
4089 Error_Msg_N
4090 ("invalid context for deferred constant declaration (RM 7.4)",
4092 Error_Msg_N
4093 ("\declaration requires an initialization expression",
4095 Set_Constant_Present (N, False);
4097 -- In Ada 83, deferred constant must be of private type
4099 elsif not Is_Private_Type (T) then
4100 if Ada_Version = Ada_83 and then Comes_From_Source (N) then
4101 Error_Msg_N
4102 ("(Ada 83) deferred constant must be private type", N);
4103 end if;
4104 end if;
4106 -- If not a deferred constant, then the object declaration freezes
4107 -- its type, unless the object is of an anonymous type and has delayed
4108 -- aspects. In that case the type is frozen when the object itself is.
4110 else
4111 Check_Fully_Declared (T, N);
4113 if Has_Delayed_Aspects (Id)
4114 and then Is_Array_Type (T)
4115 and then Is_Itype (T)
4116 then
4117 Set_Has_Delayed_Freeze (T);
4118 else
4119 Freeze_Before (N, T);
4120 end if;
4121 end if;
4123 -- If the object was created by a constrained array definition, then
4124 -- set the link in both the anonymous base type and anonymous subtype
4125 -- that are built to represent the array type to point to the object.
4127 if Nkind (Object_Definition (Declaration_Node (Id))) =
4128 N_Constrained_Array_Definition
4129 then
4130 Set_Related_Array_Object (T, Id);
4131 Set_Related_Array_Object (Base_Type (T), Id);
4132 end if;
4134 -- Special checks for protected objects not at library level
4136 if Has_Protected (T) and then not Is_Library_Level_Entity (Id) then
4137 Check_Restriction (No_Local_Protected_Objects, Id);
4139 -- Protected objects with interrupt handlers must be at library level
4141 -- Ada 2005: This test is not needed (and the corresponding clause
4142 -- in the RM is removed) because accessibility checks are sufficient
4143 -- to make handlers not at the library level illegal.
4145 -- AI05-0303: The AI is in fact a binding interpretation, and thus
4146 -- applies to the '95 version of the language as well.
4148 if Is_Protected_Type (T)
4149 and then Has_Interrupt_Handler (T)
4150 and then Ada_Version < Ada_95
4151 then
4152 Error_Msg_N
4153 ("interrupt object can only be declared at library level", Id);
4154 end if;
4155 end if;
4157 -- Check for violation of No_Local_Timing_Events
4159 if Has_Timing_Event (T) and then not Is_Library_Level_Entity (Id) then
4160 Check_Restriction (No_Local_Timing_Events, Id);
4161 end if;
4163 -- The actual subtype of the object is the nominal subtype, unless
4164 -- the nominal one is unconstrained and obtained from the expression.
4166 Act_T := T;
4168 -- These checks should be performed before the initialization expression
4169 -- is considered, so that the Object_Definition node is still the same
4170 -- as in source code.
4172 -- In SPARK, the nominal subtype is always given by a subtype mark
4173 -- and must not be unconstrained. (The only exception to this is the
4174 -- acceptance of declarations of constants of type String.)
4176 if not Nkind_In (Object_Definition (N), N_Expanded_Name, N_Identifier)
4177 then
4178 Check_SPARK_05_Restriction
4179 ("subtype mark required", Object_Definition (N));
4181 elsif Is_Array_Type (T)
4182 and then not Is_Constrained (T)
4183 and then T /= Standard_String
4184 then
4185 Check_SPARK_05_Restriction
4186 ("subtype mark of constrained type expected",
4187 Object_Definition (N));
4188 end if;
4190 if Is_Library_Level_Entity (Id) then
4191 Check_Dynamic_Object (T);
4192 end if;
4194 -- There are no aliased objects in SPARK
4196 if Aliased_Present (N) then
4197 Check_SPARK_05_Restriction ("aliased object is not allowed", N);
4198 end if;
4200 -- Process initialization expression if present and not in error
4202 if Present (E) and then E /= Error then
4204 -- Generate an error in case of CPP class-wide object initialization.
4205 -- Required because otherwise the expansion of the class-wide
4206 -- assignment would try to use 'size to initialize the object
4207 -- (primitive that is not available in CPP tagged types).
4209 if Is_Class_Wide_Type (Act_T)
4210 and then
4211 (Is_CPP_Class (Root_Type (Etype (Act_T)))
4212 or else
4213 (Present (Full_View (Root_Type (Etype (Act_T))))
4214 and then
4215 Is_CPP_Class (Full_View (Root_Type (Etype (Act_T))))))
4216 then
4217 Error_Msg_N
4218 ("predefined assignment not available for 'C'P'P tagged types",
4220 end if;
4222 Mark_Coextensions (N, E);
4223 Analyze (E);
4225 -- In case of errors detected in the analysis of the expression,
4226 -- decorate it with the expected type to avoid cascaded errors
4228 if No (Etype (E)) then
4229 Set_Etype (E, T);
4230 end if;
4232 -- If an initialization expression is present, then we set the
4233 -- Is_True_Constant flag. It will be reset if this is a variable
4234 -- and it is indeed modified.
4236 Set_Is_True_Constant (Id, True);
4238 -- If we are analyzing a constant declaration, set its completion
4239 -- flag after analyzing and resolving the expression.
4241 if Constant_Present (N) then
4242 Set_Has_Completion (Id);
4243 end if;
4245 -- Set type and resolve (type may be overridden later on). Note:
4246 -- Ekind (Id) must still be E_Void at this point so that incorrect
4247 -- early usage within E is properly diagnosed.
4249 Set_Etype (Id, T);
4251 -- If the expression is an aggregate we must look ahead to detect
4252 -- the possible presence of an address clause, and defer resolution
4253 -- and expansion of the aggregate to the freeze point of the entity.
4255 -- This is not always legal because the aggregate may contain other
4256 -- references that need freezing, e.g. references to other entities
4257 -- with address clauses. In any case, when compiling with -gnatI the
4258 -- presence of the address clause must be ignored.
4260 if Comes_From_Source (N)
4261 and then Expander_Active
4262 and then Nkind (E) = N_Aggregate
4263 and then
4264 ((Present (Following_Address_Clause (N))
4265 and then not Ignore_Rep_Clauses)
4266 or else Delayed_Aspect_Present)
4267 then
4268 Set_Etype (E, T);
4270 else
4271 Resolve (E, T);
4272 end if;
4274 -- No further action needed if E is a call to an inlined function
4275 -- which returns an unconstrained type and it has been expanded into
4276 -- a procedure call. In that case N has been replaced by an object
4277 -- declaration without initializing expression and it has been
4278 -- analyzed (see Expand_Inlined_Call).
4280 if Back_End_Inlining
4281 and then Expander_Active
4282 and then Nkind (E) = N_Function_Call
4283 and then Nkind (Name (E)) in N_Has_Entity
4284 and then Is_Inlined (Entity (Name (E)))
4285 and then not Is_Constrained (Etype (E))
4286 and then Analyzed (N)
4287 and then No (Expression (N))
4288 then
4289 goto Leave;
4290 end if;
4292 -- If E is null and has been replaced by an N_Raise_Constraint_Error
4293 -- node (which was marked already-analyzed), we need to set the type
4294 -- to something other than Any_Access in order to keep gigi happy.
4296 if Etype (E) = Any_Access then
4297 Set_Etype (E, T);
4298 end if;
4300 -- If the object is an access to variable, the initialization
4301 -- expression cannot be an access to constant.
4303 if Is_Access_Type (T)
4304 and then not Is_Access_Constant (T)
4305 and then Is_Access_Type (Etype (E))
4306 and then Is_Access_Constant (Etype (E))
4307 then
4308 Error_Msg_N
4309 ("access to variable cannot be initialized with an "
4310 & "access-to-constant expression", E);
4311 end if;
4313 if not Assignment_OK (N) then
4314 Check_Initialization (T, E);
4315 end if;
4317 Check_Unset_Reference (E);
4319 -- If this is a variable, then set current value. If this is a
4320 -- declared constant of a scalar type with a static expression,
4321 -- indicate that it is always valid.
4323 if not Constant_Present (N) then
4324 if Compile_Time_Known_Value (E) then
4325 Set_Current_Value (Id, E);
4326 end if;
4328 elsif Is_Scalar_Type (T) and then Is_OK_Static_Expression (E) then
4329 Set_Is_Known_Valid (Id);
4330 end if;
4332 -- Deal with setting of null flags
4334 if Is_Access_Type (T) then
4335 if Known_Non_Null (E) then
4336 Set_Is_Known_Non_Null (Id, True);
4337 elsif Known_Null (E) and then not Can_Never_Be_Null (Id) then
4338 Set_Is_Known_Null (Id, True);
4339 end if;
4340 end if;
4342 -- Check incorrect use of dynamically tagged expressions
4344 if Is_Tagged_Type (T) then
4345 Check_Dynamically_Tagged_Expression
4346 (Expr => E,
4347 Typ => T,
4348 Related_Nod => N);
4349 end if;
4351 Apply_Scalar_Range_Check (E, T);
4352 Apply_Static_Length_Check (E, T);
4354 if Nkind (Original_Node (N)) = N_Object_Declaration
4355 and then Comes_From_Source (Original_Node (N))
4357 -- Only call test if needed
4359 and then Restriction_Check_Required (SPARK_05)
4360 and then not Is_SPARK_05_Initialization_Expr (Original_Node (E))
4361 then
4362 Check_SPARK_05_Restriction
4363 ("initialization expression is not appropriate", E);
4364 end if;
4366 -- A formal parameter of a specific tagged type whose related
4367 -- subprogram is subject to pragma Extensions_Visible with value
4368 -- "False" cannot be implicitly converted to a class-wide type by
4369 -- means of an initialization expression (SPARK RM 6.1.7(3)). Do
4370 -- not consider internally generated expressions.
4372 if Is_Class_Wide_Type (T)
4373 and then Comes_From_Source (E)
4374 and then Is_EVF_Expression (E)
4375 then
4376 Error_Msg_N
4377 ("formal parameter cannot be implicitly converted to "
4378 & "class-wide type when Extensions_Visible is False", E);
4379 end if;
4380 end if;
4382 -- If the No_Streams restriction is set, check that the type of the
4383 -- object is not, and does not contain, any subtype derived from
4384 -- Ada.Streams.Root_Stream_Type. Note that we guard the call to
4385 -- Has_Stream just for efficiency reasons. There is no point in
4386 -- spending time on a Has_Stream check if the restriction is not set.
4388 if Restriction_Check_Required (No_Streams) then
4389 if Has_Stream (T) then
4390 Check_Restriction (No_Streams, N);
4391 end if;
4392 end if;
4394 -- Deal with predicate check before we start to do major rewriting. It
4395 -- is OK to initialize and then check the initialized value, since the
4396 -- object goes out of scope if we get a predicate failure. Note that we
4397 -- do this in the analyzer and not the expander because the analyzer
4398 -- does some substantial rewriting in some cases.
4400 -- We need a predicate check if the type has predicates that are not
4401 -- ignored, and if either there is an initializing expression, or for
4402 -- default initialization when we have at least one case of an explicit
4403 -- default initial value and then this is not an internal declaration
4404 -- whose initialization comes later (as for an aggregate expansion).
4406 if not Suppress_Assignment_Checks (N)
4407 and then Present (Predicate_Function (T))
4408 and then not Predicates_Ignored (T)
4409 and then not No_Initialization (N)
4410 and then
4411 (Present (E)
4412 or else
4413 Is_Partially_Initialized_Type (T, Include_Implicit => False))
4414 then
4415 -- If the type has a static predicate and the expression is known at
4416 -- compile time, see if the expression satisfies the predicate.
4418 if Present (E) then
4419 Check_Expression_Against_Static_Predicate (E, T);
4420 end if;
4422 -- If the type is a null record and there is no explicit initial
4423 -- expression, no predicate check applies.
4425 if No (E) and then Is_Null_Record_Type (T) then
4426 null;
4428 -- Do not generate a predicate check if the initialization expression
4429 -- is a type conversion because the conversion has been subjected to
4430 -- the same check. This is a small optimization which avoid redundant
4431 -- checks.
4433 elsif Present (E) and then Nkind (E) = N_Type_Conversion then
4434 null;
4436 else
4437 Insert_After (N,
4438 Make_Predicate_Check (T, New_Occurrence_Of (Id, Loc)));
4439 end if;
4440 end if;
4442 -- Case of unconstrained type
4444 if not Is_Definite_Subtype (T) then
4446 -- In SPARK, a declaration of unconstrained type is allowed
4447 -- only for constants of type string.
4449 if Is_String_Type (T) and then not Constant_Present (N) then
4450 Check_SPARK_05_Restriction
4451 ("declaration of object of unconstrained type not allowed", N);
4452 end if;
4454 -- Nothing to do in deferred constant case
4456 if Constant_Present (N) and then No (E) then
4457 null;
4459 -- Case of no initialization present
4461 elsif No (E) then
4462 if No_Initialization (N) then
4463 null;
4465 elsif Is_Class_Wide_Type (T) then
4466 Error_Msg_N
4467 ("initialization required in class-wide declaration ", N);
4469 else
4470 Error_Msg_N
4471 ("unconstrained subtype not allowed (need initialization)",
4472 Object_Definition (N));
4474 if Is_Record_Type (T) and then Has_Discriminants (T) then
4475 Error_Msg_N
4476 ("\provide initial value or explicit discriminant values",
4477 Object_Definition (N));
4479 Error_Msg_NE
4480 ("\or give default discriminant values for type&",
4481 Object_Definition (N), T);
4483 elsif Is_Array_Type (T) then
4484 Error_Msg_N
4485 ("\provide initial value or explicit array bounds",
4486 Object_Definition (N));
4487 end if;
4488 end if;
4490 -- Case of initialization present but in error. Set initial
4491 -- expression as absent (but do not make above complaints)
4493 elsif E = Error then
4494 Set_Expression (N, Empty);
4495 E := Empty;
4497 -- Case of initialization present
4499 else
4500 -- Check restrictions in Ada 83
4502 if not Constant_Present (N) then
4504 -- Unconstrained variables not allowed in Ada 83 mode
4506 if Ada_Version = Ada_83
4507 and then Comes_From_Source (Object_Definition (N))
4508 then
4509 Error_Msg_N
4510 ("(Ada 83) unconstrained variable not allowed",
4511 Object_Definition (N));
4512 end if;
4513 end if;
4515 -- Now we constrain the variable from the initializing expression
4517 -- If the expression is an aggregate, it has been expanded into
4518 -- individual assignments. Retrieve the actual type from the
4519 -- expanded construct.
4521 if Is_Array_Type (T)
4522 and then No_Initialization (N)
4523 and then Nkind (Original_Node (E)) = N_Aggregate
4524 then
4525 Act_T := Etype (E);
4527 -- In case of class-wide interface object declarations we delay
4528 -- the generation of the equivalent record type declarations until
4529 -- its expansion because there are cases in they are not required.
4531 elsif Is_Interface (T) then
4532 null;
4534 -- In GNATprove mode, Expand_Subtype_From_Expr does nothing. Thus,
4535 -- we should prevent the generation of another Itype with the
4536 -- same name as the one already generated, or we end up with
4537 -- two identical types in GNATprove.
4539 elsif GNATprove_Mode then
4540 null;
4542 -- If the type is an unchecked union, no subtype can be built from
4543 -- the expression. Rewrite declaration as a renaming, which the
4544 -- back-end can handle properly. This is a rather unusual case,
4545 -- because most unchecked_union declarations have default values
4546 -- for discriminants and are thus not indefinite.
4548 elsif Is_Unchecked_Union (T) then
4549 if Constant_Present (N) or else Nkind (E) = N_Function_Call then
4550 Set_Ekind (Id, E_Constant);
4551 else
4552 Set_Ekind (Id, E_Variable);
4553 end if;
4555 Rewrite (N,
4556 Make_Object_Renaming_Declaration (Loc,
4557 Defining_Identifier => Id,
4558 Subtype_Mark => New_Occurrence_Of (T, Loc),
4559 Name => E));
4561 Set_Renamed_Object (Id, E);
4562 Freeze_Before (N, T);
4563 Set_Is_Frozen (Id);
4564 goto Leave;
4566 else
4567 -- Ensure that the generated subtype has a unique external name
4568 -- when the related object is public. This guarantees that the
4569 -- subtype and its bounds will not be affected by switches or
4570 -- pragmas that may offset the internal counter due to extra
4571 -- generated code.
4573 if Is_Public (Id) then
4574 Related_Id := Id;
4575 else
4576 Related_Id := Empty;
4577 end if;
4579 Expand_Subtype_From_Expr
4580 (N => N,
4581 Unc_Type => T,
4582 Subtype_Indic => Object_Definition (N),
4583 Exp => E,
4584 Related_Id => Related_Id);
4586 Act_T := Find_Type_Of_Object (Object_Definition (N), N);
4587 end if;
4589 Set_Is_Constr_Subt_For_U_Nominal (Act_T);
4591 if Aliased_Present (N) then
4592 Set_Is_Constr_Subt_For_UN_Aliased (Act_T);
4593 end if;
4595 Freeze_Before (N, Act_T);
4596 Freeze_Before (N, T);
4597 end if;
4599 elsif Is_Array_Type (T)
4600 and then No_Initialization (N)
4601 and then (Nkind (Original_Node (E)) = N_Aggregate
4602 or else (Nkind (Original_Node (E)) = N_Qualified_Expression
4603 and then Nkind (Original_Node (Expression
4604 (Original_Node (E)))) = N_Aggregate))
4605 then
4606 if not Is_Entity_Name (Object_Definition (N)) then
4607 Act_T := Etype (E);
4608 Check_Compile_Time_Size (Act_T);
4610 if Aliased_Present (N) then
4611 Set_Is_Constr_Subt_For_UN_Aliased (Act_T);
4612 end if;
4613 end if;
4615 -- When the given object definition and the aggregate are specified
4616 -- independently, and their lengths might differ do a length check.
4617 -- This cannot happen if the aggregate is of the form (others =>...)
4619 if not Is_Constrained (T) then
4620 null;
4622 elsif Nkind (E) = N_Raise_Constraint_Error then
4624 -- Aggregate is statically illegal. Place back in declaration
4626 Set_Expression (N, E);
4627 Set_No_Initialization (N, False);
4629 elsif T = Etype (E) then
4630 null;
4632 elsif Nkind (E) = N_Aggregate
4633 and then Present (Component_Associations (E))
4634 and then Present (Choice_List (First (Component_Associations (E))))
4635 and then
4636 Nkind (First (Choice_List (First (Component_Associations (E))))) =
4637 N_Others_Choice
4638 then
4639 null;
4641 else
4642 Apply_Length_Check (E, T);
4643 end if;
4645 -- If the type is limited unconstrained with defaulted discriminants and
4646 -- there is no expression, then the object is constrained by the
4647 -- defaults, so it is worthwhile building the corresponding subtype.
4649 elsif (Is_Limited_Record (T) or else Is_Concurrent_Type (T))
4650 and then not Is_Constrained (T)
4651 and then Has_Discriminants (T)
4652 then
4653 if No (E) then
4654 Act_T := Build_Default_Subtype (T, N);
4655 else
4656 -- Ada 2005: A limited object may be initialized by means of an
4657 -- aggregate. If the type has default discriminants it has an
4658 -- unconstrained nominal type, Its actual subtype will be obtained
4659 -- from the aggregate, and not from the default discriminants.
4661 Act_T := Etype (E);
4662 end if;
4664 Rewrite (Object_Definition (N), New_Occurrence_Of (Act_T, Loc));
4666 elsif Nkind (E) = N_Function_Call
4667 and then Constant_Present (N)
4668 and then Has_Unconstrained_Elements (Etype (E))
4669 then
4670 -- The back-end has problems with constants of a discriminated type
4671 -- with defaults, if the initial value is a function call. We
4672 -- generate an intermediate temporary that will receive a reference
4673 -- to the result of the call. The initialization expression then
4674 -- becomes a dereference of that temporary.
4676 Remove_Side_Effects (E);
4678 -- If this is a constant declaration of an unconstrained type and
4679 -- the initialization is an aggregate, we can use the subtype of the
4680 -- aggregate for the declared entity because it is immutable.
4682 elsif not Is_Constrained (T)
4683 and then Has_Discriminants (T)
4684 and then Constant_Present (N)
4685 and then not Has_Unchecked_Union (T)
4686 and then Nkind (E) = N_Aggregate
4687 then
4688 Act_T := Etype (E);
4689 end if;
4691 -- Check No_Wide_Characters restriction
4693 Check_Wide_Character_Restriction (T, Object_Definition (N));
4695 -- Indicate this is not set in source. Certainly true for constants, and
4696 -- true for variables so far (will be reset for a variable if and when
4697 -- we encounter a modification in the source).
4699 Set_Never_Set_In_Source (Id);
4701 -- Now establish the proper kind and type of the object
4703 if Constant_Present (N) then
4704 Set_Ekind (Id, E_Constant);
4705 Set_Is_True_Constant (Id);
4707 else
4708 Set_Ekind (Id, E_Variable);
4710 -- A variable is set as shared passive if it appears in a shared
4711 -- passive package, and is at the outer level. This is not done for
4712 -- entities generated during expansion, because those are always
4713 -- manipulated locally.
4715 if Is_Shared_Passive (Current_Scope)
4716 and then Is_Library_Level_Entity (Id)
4717 and then Comes_From_Source (Id)
4718 then
4719 Set_Is_Shared_Passive (Id);
4720 Check_Shared_Var (Id, T, N);
4721 end if;
4723 -- Set Has_Initial_Value if initializing expression present. Note
4724 -- that if there is no initializing expression, we leave the state
4725 -- of this flag unchanged (usually it will be False, but notably in
4726 -- the case of exception choice variables, it will already be true).
4728 if Present (E) then
4729 Set_Has_Initial_Value (Id);
4730 end if;
4731 end if;
4733 -- Set the SPARK mode from the current context (may be overwritten later
4734 -- with explicit pragma).
4736 Set_SPARK_Pragma (Id, SPARK_Mode_Pragma);
4737 Set_SPARK_Pragma_Inherited (Id);
4739 -- Preserve relevant elaboration-related attributes of the context which
4740 -- are no longer available or very expensive to recompute once analysis,
4741 -- resolution, and expansion are over.
4743 Mark_Elaboration_Attributes
4744 (N_Id => Id,
4745 Checks => True);
4747 -- Initialize alignment and size and capture alignment setting
4749 Init_Alignment (Id);
4750 Init_Esize (Id);
4751 Set_Optimize_Alignment_Flags (Id);
4753 -- Deal with aliased case
4755 if Aliased_Present (N) then
4756 Set_Is_Aliased (Id);
4758 -- If the object is aliased and the type is unconstrained with
4759 -- defaulted discriminants and there is no expression, then the
4760 -- object is constrained by the defaults, so it is worthwhile
4761 -- building the corresponding subtype.
4763 -- Ada 2005 (AI-363): If the aliased object is discriminated and
4764 -- unconstrained, then only establish an actual subtype if the
4765 -- nominal subtype is indefinite. In definite cases the object is
4766 -- unconstrained in Ada 2005.
4768 if No (E)
4769 and then Is_Record_Type (T)
4770 and then not Is_Constrained (T)
4771 and then Has_Discriminants (T)
4772 and then (Ada_Version < Ada_2005
4773 or else not Is_Definite_Subtype (T))
4774 then
4775 Set_Actual_Subtype (Id, Build_Default_Subtype (T, N));
4776 end if;
4777 end if;
4779 -- Now we can set the type of the object
4781 Set_Etype (Id, Act_T);
4783 -- Non-constant object is marked to be treated as volatile if type is
4784 -- volatile and we clear the Current_Value setting that may have been
4785 -- set above. Doing so for constants isn't required and might interfere
4786 -- with possible uses of the object as a static expression in contexts
4787 -- incompatible with volatility (e.g. as a case-statement alternative).
4789 if Ekind (Id) /= E_Constant and then Treat_As_Volatile (Etype (Id)) then
4790 Set_Treat_As_Volatile (Id);
4791 Set_Current_Value (Id, Empty);
4792 end if;
4794 -- Deal with controlled types
4796 if Has_Controlled_Component (Etype (Id))
4797 or else Is_Controlled (Etype (Id))
4798 then
4799 if not Is_Library_Level_Entity (Id) then
4800 Check_Restriction (No_Nested_Finalization, N);
4801 else
4802 Validate_Controlled_Object (Id);
4803 end if;
4804 end if;
4806 if Has_Task (Etype (Id)) then
4807 Check_Restriction (No_Tasking, N);
4809 -- Deal with counting max tasks
4811 -- Nothing to do if inside a generic
4813 if Inside_A_Generic then
4814 null;
4816 -- If library level entity, then count tasks
4818 elsif Is_Library_Level_Entity (Id) then
4819 Check_Restriction (Max_Tasks, N, Count_Tasks (Etype (Id)));
4821 -- If not library level entity, then indicate we don't know max
4822 -- tasks and also check task hierarchy restriction and blocking
4823 -- operation (since starting a task is definitely blocking).
4825 else
4826 Check_Restriction (Max_Tasks, N);
4827 Check_Restriction (No_Task_Hierarchy, N);
4828 Check_Potentially_Blocking_Operation (N);
4829 end if;
4831 -- A rather specialized test. If we see two tasks being declared
4832 -- of the same type in the same object declaration, and the task
4833 -- has an entry with an address clause, we know that program error
4834 -- will be raised at run time since we can't have two tasks with
4835 -- entries at the same address.
4837 if Is_Task_Type (Etype (Id)) and then More_Ids (N) then
4838 declare
4839 E : Entity_Id;
4841 begin
4842 E := First_Entity (Etype (Id));
4843 while Present (E) loop
4844 if Ekind (E) = E_Entry
4845 and then Present (Get_Attribute_Definition_Clause
4846 (E, Attribute_Address))
4847 then
4848 Error_Msg_Warn := SPARK_Mode /= On;
4849 Error_Msg_N
4850 ("more than one task with same entry address<<", N);
4851 Error_Msg_N ("\Program_Error [<<", N);
4852 Insert_Action (N,
4853 Make_Raise_Program_Error (Loc,
4854 Reason => PE_Duplicated_Entry_Address));
4855 exit;
4856 end if;
4858 Next_Entity (E);
4859 end loop;
4860 end;
4861 end if;
4862 end if;
4864 -- Some simple constant-propagation: if the expression is a constant
4865 -- string initialized with a literal, share the literal. This avoids
4866 -- a run-time copy.
4868 if Present (E)
4869 and then Is_Entity_Name (E)
4870 and then Ekind (Entity (E)) = E_Constant
4871 and then Base_Type (Etype (E)) = Standard_String
4872 then
4873 declare
4874 Val : constant Node_Id := Constant_Value (Entity (E));
4875 begin
4876 if Present (Val) and then Nkind (Val) = N_String_Literal then
4877 Rewrite (E, New_Copy (Val));
4878 end if;
4879 end;
4880 end if;
4882 -- Another optimization: if the nominal subtype is unconstrained and
4883 -- the expression is a function call that returns an unconstrained
4884 -- type, rewrite the declaration as a renaming of the result of the
4885 -- call. The exceptions below are cases where the copy is expected,
4886 -- either by the back end (Aliased case) or by the semantics, as for
4887 -- initializing controlled types or copying tags for class-wide types.
4889 if Present (E)
4890 and then Nkind (E) = N_Explicit_Dereference
4891 and then Nkind (Original_Node (E)) = N_Function_Call
4892 and then not Is_Library_Level_Entity (Id)
4893 and then not Is_Constrained (Underlying_Type (T))
4894 and then not Is_Aliased (Id)
4895 and then not Is_Class_Wide_Type (T)
4896 and then not Is_Controlled (T)
4897 and then not Has_Controlled_Component (Base_Type (T))
4898 and then Expander_Active
4899 then
4900 Rewrite (N,
4901 Make_Object_Renaming_Declaration (Loc,
4902 Defining_Identifier => Id,
4903 Access_Definition => Empty,
4904 Subtype_Mark => New_Occurrence_Of
4905 (Base_Type (Etype (Id)), Loc),
4906 Name => E));
4908 Set_Renamed_Object (Id, E);
4910 -- Force generation of debugging information for the constant and for
4911 -- the renamed function call.
4913 Set_Debug_Info_Needed (Id);
4914 Set_Debug_Info_Needed (Entity (Prefix (E)));
4915 end if;
4917 if Present (Prev_Entity)
4918 and then Is_Frozen (Prev_Entity)
4919 and then not Error_Posted (Id)
4920 then
4921 Error_Msg_N ("full constant declaration appears too late", N);
4922 end if;
4924 Check_Eliminated (Id);
4926 -- Deal with setting In_Private_Part flag if in private part
4928 if Ekind (Scope (Id)) = E_Package
4929 and then In_Private_Part (Scope (Id))
4930 then
4931 Set_In_Private_Part (Id);
4932 end if;
4934 <<Leave>>
4935 -- Initialize the refined state of a variable here because this is a
4936 -- common destination for legal and illegal object declarations.
4938 if Ekind (Id) = E_Variable then
4939 Set_Encapsulating_State (Id, Empty);
4940 end if;
4942 if Has_Aspects (N) then
4943 Analyze_Aspect_Specifications (N, Id);
4944 end if;
4946 Analyze_Dimension (N);
4948 -- Verify whether the object declaration introduces an illegal hidden
4949 -- state within a package subject to a null abstract state.
4951 if Ekind (Id) = E_Variable then
4952 Check_No_Hidden_State (Id);
4953 end if;
4955 Restore_Ghost_Mode (Saved_GM);
4956 end Analyze_Object_Declaration;
4958 ---------------------------
4959 -- Analyze_Others_Choice --
4960 ---------------------------
4962 -- Nothing to do for the others choice node itself, the semantic analysis
4963 -- of the others choice will occur as part of the processing of the parent
4965 procedure Analyze_Others_Choice (N : Node_Id) is
4966 pragma Warnings (Off, N);
4967 begin
4968 null;
4969 end Analyze_Others_Choice;
4971 -------------------------------------------
4972 -- Analyze_Private_Extension_Declaration --
4973 -------------------------------------------
4975 procedure Analyze_Private_Extension_Declaration (N : Node_Id) is
4976 Indic : constant Node_Id := Subtype_Indication (N);
4977 T : constant Entity_Id := Defining_Identifier (N);
4978 Iface : Entity_Id;
4979 Iface_Elmt : Elmt_Id;
4980 Parent_Base : Entity_Id;
4981 Parent_Type : Entity_Id;
4983 begin
4984 -- Ada 2005 (AI-251): Decorate all names in list of ancestor interfaces
4986 if Is_Non_Empty_List (Interface_List (N)) then
4987 declare
4988 Intf : Node_Id;
4989 T : Entity_Id;
4991 begin
4992 Intf := First (Interface_List (N));
4993 while Present (Intf) loop
4994 T := Find_Type_Of_Subtype_Indic (Intf);
4996 Diagnose_Interface (Intf, T);
4997 Next (Intf);
4998 end loop;
4999 end;
5000 end if;
5002 Generate_Definition (T);
5004 -- For other than Ada 2012, just enter the name in the current scope
5006 if Ada_Version < Ada_2012 then
5007 Enter_Name (T);
5009 -- Ada 2012 (AI05-0162): Enter the name in the current scope handling
5010 -- case of private type that completes an incomplete type.
5012 else
5013 declare
5014 Prev : Entity_Id;
5016 begin
5017 Prev := Find_Type_Name (N);
5019 pragma Assert (Prev = T
5020 or else (Ekind (Prev) = E_Incomplete_Type
5021 and then Present (Full_View (Prev))
5022 and then Full_View (Prev) = T));
5023 end;
5024 end if;
5026 Parent_Type := Find_Type_Of_Subtype_Indic (Indic);
5027 Parent_Base := Base_Type (Parent_Type);
5029 if Parent_Type = Any_Type or else Etype (Parent_Type) = Any_Type then
5030 Set_Ekind (T, Ekind (Parent_Type));
5031 Set_Etype (T, Any_Type);
5032 goto Leave;
5034 elsif not Is_Tagged_Type (Parent_Type) then
5035 Error_Msg_N
5036 ("parent of type extension must be a tagged type ", Indic);
5037 goto Leave;
5039 elsif Ekind_In (Parent_Type, E_Void, E_Incomplete_Type) then
5040 Error_Msg_N ("premature derivation of incomplete type", Indic);
5041 goto Leave;
5043 elsif Is_Concurrent_Type (Parent_Type) then
5044 Error_Msg_N
5045 ("parent type of a private extension cannot be a synchronized "
5046 & "tagged type (RM 3.9.1 (3/1))", N);
5048 Set_Etype (T, Any_Type);
5049 Set_Ekind (T, E_Limited_Private_Type);
5050 Set_Private_Dependents (T, New_Elmt_List);
5051 Set_Error_Posted (T);
5052 goto Leave;
5053 end if;
5055 -- Perhaps the parent type should be changed to the class-wide type's
5056 -- specific type in this case to prevent cascading errors ???
5058 if Is_Class_Wide_Type (Parent_Type) then
5059 Error_Msg_N
5060 ("parent of type extension must not be a class-wide type", Indic);
5061 goto Leave;
5062 end if;
5064 if (not Is_Package_Or_Generic_Package (Current_Scope)
5065 and then Nkind (Parent (N)) /= N_Generic_Subprogram_Declaration)
5066 or else In_Private_Part (Current_Scope)
5067 then
5068 Error_Msg_N ("invalid context for private extension", N);
5069 end if;
5071 -- Set common attributes
5073 Set_Is_Pure (T, Is_Pure (Current_Scope));
5074 Set_Scope (T, Current_Scope);
5075 Set_Ekind (T, E_Record_Type_With_Private);
5076 Init_Size_Align (T);
5077 Set_Default_SSO (T);
5078 Set_No_Reordering (T, No_Component_Reordering);
5080 Set_Etype (T, Parent_Base);
5081 Propagate_Concurrent_Flags (T, Parent_Base);
5083 Set_Convention (T, Convention (Parent_Type));
5084 Set_First_Rep_Item (T, First_Rep_Item (Parent_Type));
5085 Set_Is_First_Subtype (T);
5086 Make_Class_Wide_Type (T);
5088 -- Set the SPARK mode from the current context
5090 Set_SPARK_Pragma (T, SPARK_Mode_Pragma);
5091 Set_SPARK_Pragma_Inherited (T);
5093 if Unknown_Discriminants_Present (N) then
5094 Set_Discriminant_Constraint (T, No_Elist);
5095 end if;
5097 Build_Derived_Record_Type (N, Parent_Type, T);
5099 -- A private extension inherits the Default_Initial_Condition pragma
5100 -- coming from any parent type within the derivation chain.
5102 if Has_DIC (Parent_Type) then
5103 Set_Has_Inherited_DIC (T);
5104 end if;
5106 -- A private extension inherits any class-wide invariants coming from a
5107 -- parent type or an interface. Note that the invariant procedure of the
5108 -- parent type should not be inherited because the private extension may
5109 -- define invariants of its own.
5111 if Has_Inherited_Invariants (Parent_Type)
5112 or else Has_Inheritable_Invariants (Parent_Type)
5113 then
5114 Set_Has_Inherited_Invariants (T);
5116 elsif Present (Interfaces (T)) then
5117 Iface_Elmt := First_Elmt (Interfaces (T));
5118 while Present (Iface_Elmt) loop
5119 Iface := Node (Iface_Elmt);
5121 if Has_Inheritable_Invariants (Iface) then
5122 Set_Has_Inherited_Invariants (T);
5123 exit;
5124 end if;
5126 Next_Elmt (Iface_Elmt);
5127 end loop;
5128 end if;
5130 -- Ada 2005 (AI-443): Synchronized private extension or a rewritten
5131 -- synchronized formal derived type.
5133 if Ada_Version >= Ada_2005 and then Synchronized_Present (N) then
5134 Set_Is_Limited_Record (T);
5136 -- Formal derived type case
5138 if Is_Generic_Type (T) then
5140 -- The parent must be a tagged limited type or a synchronized
5141 -- interface.
5143 if (not Is_Tagged_Type (Parent_Type)
5144 or else not Is_Limited_Type (Parent_Type))
5145 and then
5146 (not Is_Interface (Parent_Type)
5147 or else not Is_Synchronized_Interface (Parent_Type))
5148 then
5149 Error_Msg_NE
5150 ("parent type of & must be tagged limited or synchronized",
5151 N, T);
5152 end if;
5154 -- The progenitors (if any) must be limited or synchronized
5155 -- interfaces.
5157 if Present (Interfaces (T)) then
5158 Iface_Elmt := First_Elmt (Interfaces (T));
5159 while Present (Iface_Elmt) loop
5160 Iface := Node (Iface_Elmt);
5162 if not Is_Limited_Interface (Iface)
5163 and then not Is_Synchronized_Interface (Iface)
5164 then
5165 Error_Msg_NE
5166 ("progenitor & must be limited or synchronized",
5167 N, Iface);
5168 end if;
5170 Next_Elmt (Iface_Elmt);
5171 end loop;
5172 end if;
5174 -- Regular derived extension, the parent must be a limited or
5175 -- synchronized interface.
5177 else
5178 if not Is_Interface (Parent_Type)
5179 or else (not Is_Limited_Interface (Parent_Type)
5180 and then not Is_Synchronized_Interface (Parent_Type))
5181 then
5182 Error_Msg_NE
5183 ("parent type of & must be limited interface", N, T);
5184 end if;
5185 end if;
5187 -- A consequence of 3.9.4 (6/2) and 7.3 (7.2/2) is that a private
5188 -- extension with a synchronized parent must be explicitly declared
5189 -- synchronized, because the full view will be a synchronized type.
5190 -- This must be checked before the check for limited types below,
5191 -- to ensure that types declared limited are not allowed to extend
5192 -- synchronized interfaces.
5194 elsif Is_Interface (Parent_Type)
5195 and then Is_Synchronized_Interface (Parent_Type)
5196 and then not Synchronized_Present (N)
5197 then
5198 Error_Msg_NE
5199 ("private extension of& must be explicitly synchronized",
5200 N, Parent_Type);
5202 elsif Limited_Present (N) then
5203 Set_Is_Limited_Record (T);
5205 if not Is_Limited_Type (Parent_Type)
5206 and then
5207 (not Is_Interface (Parent_Type)
5208 or else not Is_Limited_Interface (Parent_Type))
5209 then
5210 Error_Msg_NE ("parent type& of limited extension must be limited",
5211 N, Parent_Type);
5212 end if;
5213 end if;
5215 -- Remember that its parent type has a private extension. Used to warn
5216 -- on public primitives of the parent type defined after its private
5217 -- extensions (see Check_Dispatching_Operation).
5219 Set_Has_Private_Extension (Parent_Type);
5221 <<Leave>>
5222 if Has_Aspects (N) then
5223 Analyze_Aspect_Specifications (N, T);
5224 end if;
5225 end Analyze_Private_Extension_Declaration;
5227 ---------------------------------
5228 -- Analyze_Subtype_Declaration --
5229 ---------------------------------
5231 procedure Analyze_Subtype_Declaration
5232 (N : Node_Id;
5233 Skip : Boolean := False)
5235 Id : constant Entity_Id := Defining_Identifier (N);
5236 R_Checks : Check_Result;
5237 T : Entity_Id;
5239 begin
5240 Generate_Definition (Id);
5241 Set_Is_Pure (Id, Is_Pure (Current_Scope));
5242 Init_Size_Align (Id);
5244 -- The following guard condition on Enter_Name is to handle cases where
5245 -- the defining identifier has already been entered into the scope but
5246 -- the declaration as a whole needs to be analyzed.
5248 -- This case in particular happens for derived enumeration types. The
5249 -- derived enumeration type is processed as an inserted enumeration type
5250 -- declaration followed by a rewritten subtype declaration. The defining
5251 -- identifier, however, is entered into the name scope very early in the
5252 -- processing of the original type declaration and therefore needs to be
5253 -- avoided here, when the created subtype declaration is analyzed. (See
5254 -- Build_Derived_Types)
5256 -- This also happens when the full view of a private type is derived
5257 -- type with constraints. In this case the entity has been introduced
5258 -- in the private declaration.
5260 -- Finally this happens in some complex cases when validity checks are
5261 -- enabled, where the same subtype declaration may be analyzed twice.
5262 -- This can happen if the subtype is created by the pre-analysis of
5263 -- an attribute tht gives the range of a loop statement, and the loop
5264 -- itself appears within an if_statement that will be rewritten during
5265 -- expansion.
5267 if Skip
5268 or else (Present (Etype (Id))
5269 and then (Is_Private_Type (Etype (Id))
5270 or else Is_Task_Type (Etype (Id))
5271 or else Is_Rewrite_Substitution (N)))
5272 then
5273 null;
5275 elsif Current_Entity (Id) = Id then
5276 null;
5278 else
5279 Enter_Name (Id);
5280 end if;
5282 T := Process_Subtype (Subtype_Indication (N), N, Id, 'P');
5284 -- Class-wide equivalent types of records with unknown discriminants
5285 -- involve the generation of an itype which serves as the private view
5286 -- of a constrained record subtype. In such cases the base type of the
5287 -- current subtype we are processing is the private itype. Use the full
5288 -- of the private itype when decorating various attributes.
5290 if Is_Itype (T)
5291 and then Is_Private_Type (T)
5292 and then Present (Full_View (T))
5293 then
5294 T := Full_View (T);
5295 end if;
5297 -- Inherit common attributes
5299 Set_Is_Volatile (Id, Is_Volatile (T));
5300 Set_Treat_As_Volatile (Id, Treat_As_Volatile (T));
5301 Set_Is_Generic_Type (Id, Is_Generic_Type (Base_Type (T)));
5302 Set_Convention (Id, Convention (T));
5304 -- If ancestor has predicates then so does the subtype, and in addition
5305 -- we must delay the freeze to properly arrange predicate inheritance.
5307 -- The Ancestor_Type test is really unpleasant, there seem to be cases
5308 -- in which T = ID, so the above tests and assignments do nothing???
5310 if Has_Predicates (T)
5311 or else (Present (Ancestor_Subtype (T))
5312 and then Has_Predicates (Ancestor_Subtype (T)))
5313 then
5314 Set_Has_Predicates (Id);
5315 Set_Has_Delayed_Freeze (Id);
5317 -- Generated subtypes inherit the predicate function from the parent
5318 -- (no aspects to examine on the generated declaration).
5320 if not Comes_From_Source (N) then
5321 Set_Ekind (Id, Ekind (T));
5323 if Present (Predicate_Function (T)) then
5324 Set_Predicate_Function (Id, Predicate_Function (T));
5326 elsif Present (Ancestor_Subtype (T))
5327 and then Has_Predicates (Ancestor_Subtype (T))
5328 and then Present (Predicate_Function (Ancestor_Subtype (T)))
5329 then
5330 Set_Predicate_Function (Id,
5331 Predicate_Function (Ancestor_Subtype (T)));
5332 end if;
5333 end if;
5334 end if;
5336 -- Subtype of Boolean cannot have a constraint in SPARK
5338 if Is_Boolean_Type (T)
5339 and then Nkind (Subtype_Indication (N)) = N_Subtype_Indication
5340 then
5341 Check_SPARK_05_Restriction
5342 ("subtype of Boolean cannot have constraint", N);
5343 end if;
5345 if Nkind (Subtype_Indication (N)) = N_Subtype_Indication then
5346 declare
5347 Cstr : constant Node_Id := Constraint (Subtype_Indication (N));
5348 One_Cstr : Node_Id;
5349 Low : Node_Id;
5350 High : Node_Id;
5352 begin
5353 if Nkind (Cstr) = N_Index_Or_Discriminant_Constraint then
5354 One_Cstr := First (Constraints (Cstr));
5355 while Present (One_Cstr) loop
5357 -- Index or discriminant constraint in SPARK must be a
5358 -- subtype mark.
5360 if not
5361 Nkind_In (One_Cstr, N_Identifier, N_Expanded_Name)
5362 then
5363 Check_SPARK_05_Restriction
5364 ("subtype mark required", One_Cstr);
5366 -- String subtype must have a lower bound of 1 in SPARK.
5367 -- Note that we do not need to test for the non-static case
5368 -- here, since that was already taken care of in
5369 -- Process_Range_Expr_In_Decl.
5371 elsif Base_Type (T) = Standard_String then
5372 Get_Index_Bounds (One_Cstr, Low, High);
5374 if Is_OK_Static_Expression (Low)
5375 and then Expr_Value (Low) /= 1
5376 then
5377 Check_SPARK_05_Restriction
5378 ("String subtype must have lower bound of 1", N);
5379 end if;
5380 end if;
5382 Next (One_Cstr);
5383 end loop;
5384 end if;
5385 end;
5386 end if;
5388 -- In the case where there is no constraint given in the subtype
5389 -- indication, Process_Subtype just returns the Subtype_Mark, so its
5390 -- semantic attributes must be established here.
5392 if Nkind (Subtype_Indication (N)) /= N_Subtype_Indication then
5393 Set_Etype (Id, Base_Type (T));
5395 -- Subtype of unconstrained array without constraint is not allowed
5396 -- in SPARK.
5398 if Is_Array_Type (T) and then not Is_Constrained (T) then
5399 Check_SPARK_05_Restriction
5400 ("subtype of unconstrained array must have constraint", N);
5401 end if;
5403 case Ekind (T) is
5404 when Array_Kind =>
5405 Set_Ekind (Id, E_Array_Subtype);
5406 Copy_Array_Subtype_Attributes (Id, T);
5408 when Decimal_Fixed_Point_Kind =>
5409 Set_Ekind (Id, E_Decimal_Fixed_Point_Subtype);
5410 Set_Digits_Value (Id, Digits_Value (T));
5411 Set_Delta_Value (Id, Delta_Value (T));
5412 Set_Scale_Value (Id, Scale_Value (T));
5413 Set_Small_Value (Id, Small_Value (T));
5414 Set_Scalar_Range (Id, Scalar_Range (T));
5415 Set_Machine_Radix_10 (Id, Machine_Radix_10 (T));
5416 Set_Is_Constrained (Id, Is_Constrained (T));
5417 Set_Is_Known_Valid (Id, Is_Known_Valid (T));
5418 Set_RM_Size (Id, RM_Size (T));
5420 when Enumeration_Kind =>
5421 Set_Ekind (Id, E_Enumeration_Subtype);
5422 Set_First_Literal (Id, First_Literal (Base_Type (T)));
5423 Set_Scalar_Range (Id, Scalar_Range (T));
5424 Set_Is_Character_Type (Id, Is_Character_Type (T));
5425 Set_Is_Constrained (Id, Is_Constrained (T));
5426 Set_Is_Known_Valid (Id, Is_Known_Valid (T));
5427 Set_RM_Size (Id, RM_Size (T));
5428 Inherit_Predicate_Flags (Id, T);
5430 when Ordinary_Fixed_Point_Kind =>
5431 Set_Ekind (Id, E_Ordinary_Fixed_Point_Subtype);
5432 Set_Scalar_Range (Id, Scalar_Range (T));
5433 Set_Small_Value (Id, Small_Value (T));
5434 Set_Delta_Value (Id, Delta_Value (T));
5435 Set_Is_Constrained (Id, Is_Constrained (T));
5436 Set_Is_Known_Valid (Id, Is_Known_Valid (T));
5437 Set_RM_Size (Id, RM_Size (T));
5439 when Float_Kind =>
5440 Set_Ekind (Id, E_Floating_Point_Subtype);
5441 Set_Scalar_Range (Id, Scalar_Range (T));
5442 Set_Digits_Value (Id, Digits_Value (T));
5443 Set_Is_Constrained (Id, Is_Constrained (T));
5445 -- If the floating point type has dimensions, these will be
5446 -- inherited subsequently when Analyze_Dimensions is called.
5448 when Signed_Integer_Kind =>
5449 Set_Ekind (Id, E_Signed_Integer_Subtype);
5450 Set_Scalar_Range (Id, Scalar_Range (T));
5451 Set_Is_Constrained (Id, Is_Constrained (T));
5452 Set_Is_Known_Valid (Id, Is_Known_Valid (T));
5453 Set_RM_Size (Id, RM_Size (T));
5454 Inherit_Predicate_Flags (Id, T);
5456 when Modular_Integer_Kind =>
5457 Set_Ekind (Id, E_Modular_Integer_Subtype);
5458 Set_Scalar_Range (Id, Scalar_Range (T));
5459 Set_Is_Constrained (Id, Is_Constrained (T));
5460 Set_Is_Known_Valid (Id, Is_Known_Valid (T));
5461 Set_RM_Size (Id, RM_Size (T));
5462 Inherit_Predicate_Flags (Id, T);
5464 when Class_Wide_Kind =>
5465 Set_Ekind (Id, E_Class_Wide_Subtype);
5466 Set_Class_Wide_Type (Id, Class_Wide_Type (T));
5467 Set_Cloned_Subtype (Id, T);
5468 Set_Is_Tagged_Type (Id, True);
5469 Set_Has_Unknown_Discriminants
5470 (Id, True);
5471 Set_No_Tagged_Streams_Pragma
5472 (Id, No_Tagged_Streams_Pragma (T));
5474 if Ekind (T) = E_Class_Wide_Subtype then
5475 Set_Equivalent_Type (Id, Equivalent_Type (T));
5476 end if;
5478 when E_Record_Subtype
5479 | E_Record_Type
5481 Set_Ekind (Id, E_Record_Subtype);
5483 if Ekind (T) = E_Record_Subtype
5484 and then Present (Cloned_Subtype (T))
5485 then
5486 Set_Cloned_Subtype (Id, Cloned_Subtype (T));
5487 else
5488 Set_Cloned_Subtype (Id, T);
5489 end if;
5491 Set_First_Entity (Id, First_Entity (T));
5492 Set_Last_Entity (Id, Last_Entity (T));
5493 Set_Has_Discriminants (Id, Has_Discriminants (T));
5494 Set_Is_Constrained (Id, Is_Constrained (T));
5495 Set_Is_Limited_Record (Id, Is_Limited_Record (T));
5496 Set_Has_Implicit_Dereference
5497 (Id, Has_Implicit_Dereference (T));
5498 Set_Has_Unknown_Discriminants
5499 (Id, Has_Unknown_Discriminants (T));
5501 if Has_Discriminants (T) then
5502 Set_Discriminant_Constraint
5503 (Id, Discriminant_Constraint (T));
5504 Set_Stored_Constraint_From_Discriminant_Constraint (Id);
5506 elsif Has_Unknown_Discriminants (Id) then
5507 Set_Discriminant_Constraint (Id, No_Elist);
5508 end if;
5510 if Is_Tagged_Type (T) then
5511 Set_Is_Tagged_Type (Id, True);
5512 Set_No_Tagged_Streams_Pragma
5513 (Id, No_Tagged_Streams_Pragma (T));
5514 Set_Is_Abstract_Type (Id, Is_Abstract_Type (T));
5515 Set_Direct_Primitive_Operations
5516 (Id, Direct_Primitive_Operations (T));
5517 Set_Class_Wide_Type (Id, Class_Wide_Type (T));
5519 if Is_Interface (T) then
5520 Set_Is_Interface (Id);
5521 Set_Is_Limited_Interface (Id, Is_Limited_Interface (T));
5522 end if;
5523 end if;
5525 when Private_Kind =>
5526 Set_Ekind (Id, Subtype_Kind (Ekind (T)));
5527 Set_Has_Discriminants (Id, Has_Discriminants (T));
5528 Set_Is_Constrained (Id, Is_Constrained (T));
5529 Set_First_Entity (Id, First_Entity (T));
5530 Set_Last_Entity (Id, Last_Entity (T));
5531 Set_Private_Dependents (Id, New_Elmt_List);
5532 Set_Is_Limited_Record (Id, Is_Limited_Record (T));
5533 Set_Has_Implicit_Dereference
5534 (Id, Has_Implicit_Dereference (T));
5535 Set_Has_Unknown_Discriminants
5536 (Id, Has_Unknown_Discriminants (T));
5537 Set_Known_To_Have_Preelab_Init
5538 (Id, Known_To_Have_Preelab_Init (T));
5540 if Is_Tagged_Type (T) then
5541 Set_Is_Tagged_Type (Id);
5542 Set_No_Tagged_Streams_Pragma (Id,
5543 No_Tagged_Streams_Pragma (T));
5544 Set_Is_Abstract_Type (Id, Is_Abstract_Type (T));
5545 Set_Class_Wide_Type (Id, Class_Wide_Type (T));
5546 Set_Direct_Primitive_Operations (Id,
5547 Direct_Primitive_Operations (T));
5548 end if;
5550 -- In general the attributes of the subtype of a private type
5551 -- are the attributes of the partial view of parent. However,
5552 -- the full view may be a discriminated type, and the subtype
5553 -- must share the discriminant constraint to generate correct
5554 -- calls to initialization procedures.
5556 if Has_Discriminants (T) then
5557 Set_Discriminant_Constraint
5558 (Id, Discriminant_Constraint (T));
5559 Set_Stored_Constraint_From_Discriminant_Constraint (Id);
5561 elsif Present (Full_View (T))
5562 and then Has_Discriminants (Full_View (T))
5563 then
5564 Set_Discriminant_Constraint
5565 (Id, Discriminant_Constraint (Full_View (T)));
5566 Set_Stored_Constraint_From_Discriminant_Constraint (Id);
5568 -- This would seem semantically correct, but apparently
5569 -- generates spurious errors about missing components ???
5571 -- Set_Has_Discriminants (Id);
5572 end if;
5574 Prepare_Private_Subtype_Completion (Id, N);
5576 -- If this is the subtype of a constrained private type with
5577 -- discriminants that has got a full view and we also have
5578 -- built a completion just above, show that the completion
5579 -- is a clone of the full view to the back-end.
5581 if Has_Discriminants (T)
5582 and then not Has_Unknown_Discriminants (T)
5583 and then not Is_Empty_Elmt_List (Discriminant_Constraint (T))
5584 and then Present (Full_View (T))
5585 and then Present (Full_View (Id))
5586 then
5587 Set_Cloned_Subtype (Full_View (Id), Full_View (T));
5588 end if;
5590 when Access_Kind =>
5591 Set_Ekind (Id, E_Access_Subtype);
5592 Set_Is_Constrained (Id, Is_Constrained (T));
5593 Set_Is_Access_Constant
5594 (Id, Is_Access_Constant (T));
5595 Set_Directly_Designated_Type
5596 (Id, Designated_Type (T));
5597 Set_Can_Never_Be_Null (Id, Can_Never_Be_Null (T));
5599 -- A Pure library_item must not contain the declaration of a
5600 -- named access type, except within a subprogram, generic
5601 -- subprogram, task unit, or protected unit, or if it has
5602 -- a specified Storage_Size of zero (RM05-10.2.1(15.4-15.5)).
5604 if Comes_From_Source (Id)
5605 and then In_Pure_Unit
5606 and then not In_Subprogram_Task_Protected_Unit
5607 and then not No_Pool_Assigned (Id)
5608 then
5609 Error_Msg_N
5610 ("named access types not allowed in pure unit", N);
5611 end if;
5613 when Concurrent_Kind =>
5614 Set_Ekind (Id, Subtype_Kind (Ekind (T)));
5615 Set_Corresponding_Record_Type (Id,
5616 Corresponding_Record_Type (T));
5617 Set_First_Entity (Id, First_Entity (T));
5618 Set_First_Private_Entity (Id, First_Private_Entity (T));
5619 Set_Has_Discriminants (Id, Has_Discriminants (T));
5620 Set_Is_Constrained (Id, Is_Constrained (T));
5621 Set_Is_Tagged_Type (Id, Is_Tagged_Type (T));
5622 Set_Last_Entity (Id, Last_Entity (T));
5624 if Is_Tagged_Type (T) then
5625 Set_No_Tagged_Streams_Pragma
5626 (Id, No_Tagged_Streams_Pragma (T));
5627 end if;
5629 if Has_Discriminants (T) then
5630 Set_Discriminant_Constraint
5631 (Id, Discriminant_Constraint (T));
5632 Set_Stored_Constraint_From_Discriminant_Constraint (Id);
5633 end if;
5635 when Incomplete_Kind =>
5636 if Ada_Version >= Ada_2005 then
5638 -- In Ada 2005 an incomplete type can be explicitly tagged:
5639 -- propagate indication. Note that we also have to include
5640 -- subtypes for Ada 2012 extended use of incomplete types.
5642 Set_Ekind (Id, E_Incomplete_Subtype);
5643 Set_Is_Tagged_Type (Id, Is_Tagged_Type (T));
5644 Set_Private_Dependents (Id, New_Elmt_List);
5646 if Is_Tagged_Type (Id) then
5647 Set_No_Tagged_Streams_Pragma
5648 (Id, No_Tagged_Streams_Pragma (T));
5649 Set_Direct_Primitive_Operations (Id, New_Elmt_List);
5650 end if;
5652 -- Ada 2005 (AI-412): Decorate an incomplete subtype of an
5653 -- incomplete type visible through a limited with clause.
5655 if From_Limited_With (T)
5656 and then Present (Non_Limited_View (T))
5657 then
5658 Set_From_Limited_With (Id);
5659 Set_Non_Limited_View (Id, Non_Limited_View (T));
5661 -- Ada 2005 (AI-412): Add the regular incomplete subtype
5662 -- to the private dependents of the original incomplete
5663 -- type for future transformation.
5665 else
5666 Append_Elmt (Id, Private_Dependents (T));
5667 end if;
5669 -- If the subtype name denotes an incomplete type an error
5670 -- was already reported by Process_Subtype.
5672 else
5673 Set_Etype (Id, Any_Type);
5674 end if;
5676 when others =>
5677 raise Program_Error;
5678 end case;
5679 end if;
5681 if Etype (Id) = Any_Type then
5682 goto Leave;
5683 end if;
5685 -- Some common processing on all types
5687 Set_Size_Info (Id, T);
5688 Set_First_Rep_Item (Id, First_Rep_Item (T));
5690 -- If the parent type is a generic actual, so is the subtype. This may
5691 -- happen in a nested instance. Why Comes_From_Source test???
5693 if not Comes_From_Source (N) then
5694 Set_Is_Generic_Actual_Type (Id, Is_Generic_Actual_Type (T));
5695 end if;
5697 -- If this is a subtype declaration for an actual in an instance,
5698 -- inherit static and dynamic predicates if any.
5700 -- If declaration has no aspect specifications, inherit predicate
5701 -- info as well. Unclear how to handle the case of both specified
5702 -- and inherited predicates ??? Other inherited aspects, such as
5703 -- invariants, should be OK, but the combination with later pragmas
5704 -- may also require special merging.
5706 if Has_Predicates (T)
5707 and then Present (Predicate_Function (T))
5708 and then
5709 ((In_Instance and then not Comes_From_Source (N))
5710 or else No (Aspect_Specifications (N)))
5711 then
5712 Set_Subprograms_For_Type (Id, Subprograms_For_Type (T));
5714 if Has_Static_Predicate (T) then
5715 Set_Has_Static_Predicate (Id);
5716 Set_Static_Discrete_Predicate (Id, Static_Discrete_Predicate (T));
5717 end if;
5718 end if;
5720 -- Remaining processing depends on characteristics of base type
5722 T := Etype (Id);
5724 Set_Is_Immediately_Visible (Id, True);
5725 Set_Depends_On_Private (Id, Has_Private_Component (T));
5726 Set_Is_Descendant_Of_Address (Id, Is_Descendant_Of_Address (T));
5728 if Is_Interface (T) then
5729 Set_Is_Interface (Id);
5730 end if;
5732 if Present (Generic_Parent_Type (N))
5733 and then
5734 (Nkind (Parent (Generic_Parent_Type (N))) /=
5735 N_Formal_Type_Declaration
5736 or else Nkind (Formal_Type_Definition
5737 (Parent (Generic_Parent_Type (N)))) /=
5738 N_Formal_Private_Type_Definition)
5739 then
5740 if Is_Tagged_Type (Id) then
5742 -- If this is a generic actual subtype for a synchronized type,
5743 -- the primitive operations are those of the corresponding record
5744 -- for which there is a separate subtype declaration.
5746 if Is_Concurrent_Type (Id) then
5747 null;
5748 elsif Is_Class_Wide_Type (Id) then
5749 Derive_Subprograms (Generic_Parent_Type (N), Id, Etype (T));
5750 else
5751 Derive_Subprograms (Generic_Parent_Type (N), Id, T);
5752 end if;
5754 elsif Scope (Etype (Id)) /= Standard_Standard then
5755 Derive_Subprograms (Generic_Parent_Type (N), Id);
5756 end if;
5757 end if;
5759 if Is_Private_Type (T) and then Present (Full_View (T)) then
5760 Conditional_Delay (Id, Full_View (T));
5762 -- The subtypes of components or subcomponents of protected types
5763 -- do not need freeze nodes, which would otherwise appear in the
5764 -- wrong scope (before the freeze node for the protected type). The
5765 -- proper subtypes are those of the subcomponents of the corresponding
5766 -- record.
5768 elsif Ekind (Scope (Id)) /= E_Protected_Type
5769 and then Present (Scope (Scope (Id))) -- error defense
5770 and then Ekind (Scope (Scope (Id))) /= E_Protected_Type
5771 then
5772 Conditional_Delay (Id, T);
5773 end if;
5775 -- If we have a subtype of an incomplete type whose full type is a
5776 -- derived numeric type, we need to have a freeze node for the subtype.
5777 -- Otherwise gigi will complain while computing the (static) bounds of
5778 -- the subtype.
5780 if Is_Itype (T)
5781 and then Is_Elementary_Type (Id)
5782 and then Etype (Id) /= Id
5783 then
5784 declare
5785 Partial : constant Entity_Id :=
5786 Incomplete_Or_Partial_View (First_Subtype (Id));
5787 begin
5788 if Present (Partial)
5789 and then Ekind (Partial) = E_Incomplete_Type
5790 then
5791 Set_Has_Delayed_Freeze (Id);
5792 end if;
5793 end;
5794 end if;
5796 -- Check that Constraint_Error is raised for a scalar subtype indication
5797 -- when the lower or upper bound of a non-null range lies outside the
5798 -- range of the type mark.
5800 if Nkind (Subtype_Indication (N)) = N_Subtype_Indication then
5801 if Is_Scalar_Type (Etype (Id))
5802 and then Scalar_Range (Id) /=
5803 Scalar_Range
5804 (Etype (Subtype_Mark (Subtype_Indication (N))))
5805 then
5806 Apply_Range_Check
5807 (Scalar_Range (Id),
5808 Etype (Subtype_Mark (Subtype_Indication (N))));
5810 -- In the array case, check compatibility for each index
5812 elsif Is_Array_Type (Etype (Id)) and then Present (First_Index (Id))
5813 then
5814 -- This really should be a subprogram that finds the indications
5815 -- to check???
5817 declare
5818 Subt_Index : Node_Id := First_Index (Id);
5819 Target_Index : Node_Id :=
5820 First_Index (Etype
5821 (Subtype_Mark (Subtype_Indication (N))));
5822 Has_Dyn_Chk : Boolean := Has_Dynamic_Range_Check (N);
5824 begin
5825 while Present (Subt_Index) loop
5826 if ((Nkind (Subt_Index) = N_Identifier
5827 and then Ekind (Entity (Subt_Index)) in Scalar_Kind)
5828 or else Nkind (Subt_Index) = N_Subtype_Indication)
5829 and then
5830 Nkind (Scalar_Range (Etype (Subt_Index))) = N_Range
5831 then
5832 declare
5833 Target_Typ : constant Entity_Id :=
5834 Etype (Target_Index);
5835 begin
5836 R_Checks :=
5837 Get_Range_Checks
5838 (Scalar_Range (Etype (Subt_Index)),
5839 Target_Typ,
5840 Etype (Subt_Index),
5841 Defining_Identifier (N));
5843 -- Reset Has_Dynamic_Range_Check on the subtype to
5844 -- prevent elision of the index check due to a dynamic
5845 -- check generated for a preceding index (needed since
5846 -- Insert_Range_Checks tries to avoid generating
5847 -- redundant checks on a given declaration).
5849 Set_Has_Dynamic_Range_Check (N, False);
5851 Insert_Range_Checks
5852 (R_Checks,
5854 Target_Typ,
5855 Sloc (Defining_Identifier (N)));
5857 -- Record whether this index involved a dynamic check
5859 Has_Dyn_Chk :=
5860 Has_Dyn_Chk or else Has_Dynamic_Range_Check (N);
5861 end;
5862 end if;
5864 Next_Index (Subt_Index);
5865 Next_Index (Target_Index);
5866 end loop;
5868 -- Finally, mark whether the subtype involves dynamic checks
5870 Set_Has_Dynamic_Range_Check (N, Has_Dyn_Chk);
5871 end;
5872 end if;
5873 end if;
5875 Set_Optimize_Alignment_Flags (Id);
5876 Check_Eliminated (Id);
5878 <<Leave>>
5879 if Has_Aspects (N) then
5880 Analyze_Aspect_Specifications (N, Id);
5881 end if;
5883 Analyze_Dimension (N);
5885 -- Check No_Dynamic_Sized_Objects restriction, which disallows subtype
5886 -- indications on composite types where the constraints are dynamic.
5887 -- Note that object declarations and aggregates generate implicit
5888 -- subtype declarations, which this covers. One special case is that the
5889 -- implicitly generated "=" for discriminated types includes an
5890 -- offending subtype declaration, which is harmless, so we ignore it
5891 -- here.
5893 if Nkind (Subtype_Indication (N)) = N_Subtype_Indication then
5894 declare
5895 Cstr : constant Node_Id := Constraint (Subtype_Indication (N));
5896 begin
5897 if Nkind (Cstr) = N_Index_Or_Discriminant_Constraint
5898 and then not (Is_Internal (Id)
5899 and then Is_TSS (Scope (Id),
5900 TSS_Composite_Equality))
5901 and then not Within_Init_Proc
5902 and then not All_Composite_Constraints_Static (Cstr)
5903 then
5904 Check_Restriction (No_Dynamic_Sized_Objects, Cstr);
5905 end if;
5906 end;
5907 end if;
5908 end Analyze_Subtype_Declaration;
5910 --------------------------------
5911 -- Analyze_Subtype_Indication --
5912 --------------------------------
5914 procedure Analyze_Subtype_Indication (N : Node_Id) is
5915 T : constant Entity_Id := Subtype_Mark (N);
5916 R : constant Node_Id := Range_Expression (Constraint (N));
5918 begin
5919 Analyze (T);
5921 if R /= Error then
5922 Analyze (R);
5923 Set_Etype (N, Etype (R));
5924 Resolve (R, Entity (T));
5925 else
5926 Set_Error_Posted (R);
5927 Set_Error_Posted (T);
5928 end if;
5929 end Analyze_Subtype_Indication;
5931 --------------------------
5932 -- Analyze_Variant_Part --
5933 --------------------------
5935 procedure Analyze_Variant_Part (N : Node_Id) is
5936 Discr_Name : Node_Id;
5937 Discr_Type : Entity_Id;
5939 procedure Process_Variant (A : Node_Id);
5940 -- Analyze declarations for a single variant
5942 package Analyze_Variant_Choices is
5943 new Generic_Analyze_Choices (Process_Variant);
5944 use Analyze_Variant_Choices;
5946 ---------------------
5947 -- Process_Variant --
5948 ---------------------
5950 procedure Process_Variant (A : Node_Id) is
5951 CL : constant Node_Id := Component_List (A);
5952 begin
5953 if not Null_Present (CL) then
5954 Analyze_Declarations (Component_Items (CL));
5956 if Present (Variant_Part (CL)) then
5957 Analyze (Variant_Part (CL));
5958 end if;
5959 end if;
5960 end Process_Variant;
5962 -- Start of processing for Analyze_Variant_Part
5964 begin
5965 Discr_Name := Name (N);
5966 Analyze (Discr_Name);
5968 -- If Discr_Name bad, get out (prevent cascaded errors)
5970 if Etype (Discr_Name) = Any_Type then
5971 return;
5972 end if;
5974 -- Check invalid discriminant in variant part
5976 if Ekind (Entity (Discr_Name)) /= E_Discriminant then
5977 Error_Msg_N ("invalid discriminant name in variant part", Discr_Name);
5978 end if;
5980 Discr_Type := Etype (Entity (Discr_Name));
5982 if not Is_Discrete_Type (Discr_Type) then
5983 Error_Msg_N
5984 ("discriminant in a variant part must be of a discrete type",
5985 Name (N));
5986 return;
5987 end if;
5989 -- Now analyze the choices, which also analyzes the declarations that
5990 -- are associated with each choice.
5992 Analyze_Choices (Variants (N), Discr_Type);
5994 -- Note: we used to instantiate and call Check_Choices here to check
5995 -- that the choices covered the discriminant, but it's too early to do
5996 -- that because of statically predicated subtypes, whose analysis may
5997 -- be deferred to their freeze point which may be as late as the freeze
5998 -- point of the containing record. So this call is now to be found in
5999 -- Freeze_Record_Declaration.
6001 end Analyze_Variant_Part;
6003 ----------------------------
6004 -- Array_Type_Declaration --
6005 ----------------------------
6007 procedure Array_Type_Declaration (T : in out Entity_Id; Def : Node_Id) is
6008 Component_Def : constant Node_Id := Component_Definition (Def);
6009 Component_Typ : constant Node_Id := Subtype_Indication (Component_Def);
6010 P : constant Node_Id := Parent (Def);
6011 Element_Type : Entity_Id;
6012 Implicit_Base : Entity_Id;
6013 Index : Node_Id;
6014 Nb_Index : Nat;
6015 Priv : Entity_Id;
6016 Related_Id : Entity_Id := Empty;
6018 begin
6019 if Nkind (Def) = N_Constrained_Array_Definition then
6020 Index := First (Discrete_Subtype_Definitions (Def));
6021 else
6022 Index := First (Subtype_Marks (Def));
6023 end if;
6025 -- Find proper names for the implicit types which may be public. In case
6026 -- of anonymous arrays we use the name of the first object of that type
6027 -- as prefix.
6029 if No (T) then
6030 Related_Id := Defining_Identifier (P);
6031 else
6032 Related_Id := T;
6033 end if;
6035 Nb_Index := 1;
6036 while Present (Index) loop
6037 Analyze (Index);
6039 -- Test for odd case of trying to index a type by the type itself
6041 if Is_Entity_Name (Index) and then Entity (Index) = T then
6042 Error_Msg_N ("type& cannot be indexed by itself", Index);
6043 Set_Entity (Index, Standard_Boolean);
6044 Set_Etype (Index, Standard_Boolean);
6045 end if;
6047 -- Check SPARK restriction requiring a subtype mark
6049 if not Nkind_In (Index, N_Identifier, N_Expanded_Name) then
6050 Check_SPARK_05_Restriction ("subtype mark required", Index);
6051 end if;
6053 -- Add a subtype declaration for each index of private array type
6054 -- declaration whose etype is also private. For example:
6056 -- package Pkg is
6057 -- type Index is private;
6058 -- private
6059 -- type Table is array (Index) of ...
6060 -- end;
6062 -- This is currently required by the expander for the internally
6063 -- generated equality subprogram of records with variant parts in
6064 -- which the etype of some component is such private type.
6066 if Ekind (Current_Scope) = E_Package
6067 and then In_Private_Part (Current_Scope)
6068 and then Has_Private_Declaration (Etype (Index))
6069 then
6070 declare
6071 Loc : constant Source_Ptr := Sloc (Def);
6072 Decl : Entity_Id;
6073 New_E : Entity_Id;
6075 begin
6076 New_E := Make_Temporary (Loc, 'T');
6077 Set_Is_Internal (New_E);
6079 Decl :=
6080 Make_Subtype_Declaration (Loc,
6081 Defining_Identifier => New_E,
6082 Subtype_Indication =>
6083 New_Occurrence_Of (Etype (Index), Loc));
6085 Insert_Before (Parent (Def), Decl);
6086 Analyze (Decl);
6087 Set_Etype (Index, New_E);
6089 -- If the index is a range or a subtype indication it carries
6090 -- no entity. Example:
6092 -- package Pkg is
6093 -- type T is private;
6094 -- private
6095 -- type T is new Natural;
6096 -- Table : array (T(1) .. T(10)) of Boolean;
6097 -- end Pkg;
6099 -- Otherwise the type of the reference is its entity.
6101 if Is_Entity_Name (Index) then
6102 Set_Entity (Index, New_E);
6103 end if;
6104 end;
6105 end if;
6107 Make_Index (Index, P, Related_Id, Nb_Index);
6109 -- Check error of subtype with predicate for index type
6111 Bad_Predicated_Subtype_Use
6112 ("subtype& has predicate, not allowed as index subtype",
6113 Index, Etype (Index));
6115 -- Move to next index
6117 Next_Index (Index);
6118 Nb_Index := Nb_Index + 1;
6119 end loop;
6121 -- Process subtype indication if one is present
6123 if Present (Component_Typ) then
6124 Element_Type := Process_Subtype (Component_Typ, P, Related_Id, 'C');
6126 Set_Etype (Component_Typ, Element_Type);
6128 if not Nkind_In (Component_Typ, N_Identifier, N_Expanded_Name) then
6129 Check_SPARK_05_Restriction
6130 ("subtype mark required", Component_Typ);
6131 end if;
6133 -- Ada 2005 (AI-230): Access Definition case
6135 else pragma Assert (Present (Access_Definition (Component_Def)));
6137 -- Indicate that the anonymous access type is created by the
6138 -- array type declaration.
6140 Element_Type := Access_Definition
6141 (Related_Nod => P,
6142 N => Access_Definition (Component_Def));
6143 Set_Is_Local_Anonymous_Access (Element_Type);
6145 -- Propagate the parent. This field is needed if we have to generate
6146 -- the master_id associated with an anonymous access to task type
6147 -- component (see Expand_N_Full_Type_Declaration.Build_Master)
6149 Set_Parent (Element_Type, Parent (T));
6151 -- Ada 2005 (AI-230): In case of components that are anonymous access
6152 -- types the level of accessibility depends on the enclosing type
6153 -- declaration
6155 Set_Scope (Element_Type, Current_Scope); -- Ada 2005 (AI-230)
6157 -- Ada 2005 (AI-254)
6159 declare
6160 CD : constant Node_Id :=
6161 Access_To_Subprogram_Definition
6162 (Access_Definition (Component_Def));
6163 begin
6164 if Present (CD) and then Protected_Present (CD) then
6165 Element_Type :=
6166 Replace_Anonymous_Access_To_Protected_Subprogram (Def);
6167 end if;
6168 end;
6169 end if;
6171 -- Constrained array case
6173 if No (T) then
6174 T := Create_Itype (E_Void, P, Related_Id, 'T');
6175 end if;
6177 if Nkind (Def) = N_Constrained_Array_Definition then
6179 -- Establish Implicit_Base as unconstrained base type
6181 Implicit_Base := Create_Itype (E_Array_Type, P, Related_Id, 'B');
6183 Set_Etype (Implicit_Base, Implicit_Base);
6184 Set_Scope (Implicit_Base, Current_Scope);
6185 Set_Has_Delayed_Freeze (Implicit_Base);
6186 Set_Default_SSO (Implicit_Base);
6188 -- The constrained array type is a subtype of the unconstrained one
6190 Set_Ekind (T, E_Array_Subtype);
6191 Init_Size_Align (T);
6192 Set_Etype (T, Implicit_Base);
6193 Set_Scope (T, Current_Scope);
6194 Set_Is_Constrained (T);
6195 Set_First_Index (T,
6196 First (Discrete_Subtype_Definitions (Def)));
6197 Set_Has_Delayed_Freeze (T);
6199 -- Complete setup of implicit base type
6201 Set_Component_Size (Implicit_Base, Uint_0);
6202 Set_Component_Type (Implicit_Base, Element_Type);
6203 Set_Finalize_Storage_Only
6204 (Implicit_Base,
6205 Finalize_Storage_Only (Element_Type));
6206 Set_First_Index (Implicit_Base, First_Index (T));
6207 Set_Has_Controlled_Component
6208 (Implicit_Base,
6209 Has_Controlled_Component (Element_Type)
6210 or else Is_Controlled (Element_Type));
6211 Set_Packed_Array_Impl_Type
6212 (Implicit_Base, Empty);
6214 Propagate_Concurrent_Flags (Implicit_Base, Element_Type);
6216 -- Unconstrained array case
6218 else
6219 Set_Ekind (T, E_Array_Type);
6220 Init_Size_Align (T);
6221 Set_Etype (T, T);
6222 Set_Scope (T, Current_Scope);
6223 Set_Component_Size (T, Uint_0);
6224 Set_Is_Constrained (T, False);
6225 Set_First_Index (T, First (Subtype_Marks (Def)));
6226 Set_Has_Delayed_Freeze (T, True);
6227 Propagate_Concurrent_Flags (T, Element_Type);
6228 Set_Has_Controlled_Component (T, Has_Controlled_Component
6229 (Element_Type)
6230 or else
6231 Is_Controlled (Element_Type));
6232 Set_Finalize_Storage_Only (T, Finalize_Storage_Only
6233 (Element_Type));
6234 Set_Default_SSO (T);
6235 end if;
6237 -- Common attributes for both cases
6239 Set_Component_Type (Base_Type (T), Element_Type);
6240 Set_Packed_Array_Impl_Type (T, Empty);
6242 if Aliased_Present (Component_Definition (Def)) then
6243 Check_SPARK_05_Restriction
6244 ("aliased is not allowed", Component_Definition (Def));
6245 Set_Has_Aliased_Components (Etype (T));
6246 end if;
6248 -- Ada 2005 (AI-231): Propagate the null-excluding attribute to the
6249 -- array type to ensure that objects of this type are initialized.
6251 if Ada_Version >= Ada_2005 and then Can_Never_Be_Null (Element_Type) then
6252 Set_Can_Never_Be_Null (T);
6254 if Null_Exclusion_Present (Component_Definition (Def))
6256 -- No need to check itypes because in their case this check was
6257 -- done at their point of creation
6259 and then not Is_Itype (Element_Type)
6260 then
6261 Error_Msg_N
6262 ("`NOT NULL` not allowed (null already excluded)",
6263 Subtype_Indication (Component_Definition (Def)));
6264 end if;
6265 end if;
6267 Priv := Private_Component (Element_Type);
6269 if Present (Priv) then
6271 -- Check for circular definitions
6273 if Priv = Any_Type then
6274 Set_Component_Type (Etype (T), Any_Type);
6276 -- There is a gap in the visibility of operations on the composite
6277 -- type only if the component type is defined in a different scope.
6279 elsif Scope (Priv) = Current_Scope then
6280 null;
6282 elsif Is_Limited_Type (Priv) then
6283 Set_Is_Limited_Composite (Etype (T));
6284 Set_Is_Limited_Composite (T);
6285 else
6286 Set_Is_Private_Composite (Etype (T));
6287 Set_Is_Private_Composite (T);
6288 end if;
6289 end if;
6291 -- A syntax error in the declaration itself may lead to an empty index
6292 -- list, in which case do a minimal patch.
6294 if No (First_Index (T)) then
6295 Error_Msg_N ("missing index definition in array type declaration", T);
6297 declare
6298 Indexes : constant List_Id :=
6299 New_List (New_Occurrence_Of (Any_Id, Sloc (T)));
6300 begin
6301 Set_Discrete_Subtype_Definitions (Def, Indexes);
6302 Set_First_Index (T, First (Indexes));
6303 return;
6304 end;
6305 end if;
6307 -- Create a concatenation operator for the new type. Internal array
6308 -- types created for packed entities do not need such, they are
6309 -- compatible with the user-defined type.
6311 if Number_Dimensions (T) = 1
6312 and then not Is_Packed_Array_Impl_Type (T)
6313 then
6314 New_Concatenation_Op (T);
6315 end if;
6317 -- In the case of an unconstrained array the parser has already verified
6318 -- that all the indexes are unconstrained but we still need to make sure
6319 -- that the element type is constrained.
6321 if not Is_Definite_Subtype (Element_Type) then
6322 Error_Msg_N
6323 ("unconstrained element type in array declaration",
6324 Subtype_Indication (Component_Def));
6326 elsif Is_Abstract_Type (Element_Type) then
6327 Error_Msg_N
6328 ("the type of a component cannot be abstract",
6329 Subtype_Indication (Component_Def));
6330 end if;
6332 -- There may be an invariant declared for the component type, but
6333 -- the construction of the component invariant checking procedure
6334 -- takes place during expansion.
6335 end Array_Type_Declaration;
6337 ------------------------------------------------------
6338 -- Replace_Anonymous_Access_To_Protected_Subprogram --
6339 ------------------------------------------------------
6341 function Replace_Anonymous_Access_To_Protected_Subprogram
6342 (N : Node_Id) return Entity_Id
6344 Loc : constant Source_Ptr := Sloc (N);
6346 Curr_Scope : constant Scope_Stack_Entry :=
6347 Scope_Stack.Table (Scope_Stack.Last);
6349 Anon : constant Entity_Id := Make_Temporary (Loc, 'S');
6351 Acc : Node_Id;
6352 -- Access definition in declaration
6354 Comp : Node_Id;
6355 -- Object definition or formal definition with an access definition
6357 Decl : Node_Id;
6358 -- Declaration of anonymous access to subprogram type
6360 Spec : Node_Id;
6361 -- Original specification in access to subprogram
6363 P : Node_Id;
6365 begin
6366 Set_Is_Internal (Anon);
6368 case Nkind (N) is
6369 when N_Constrained_Array_Definition
6370 | N_Component_Declaration
6371 | N_Unconstrained_Array_Definition
6373 Comp := Component_Definition (N);
6374 Acc := Access_Definition (Comp);
6376 when N_Discriminant_Specification =>
6377 Comp := Discriminant_Type (N);
6378 Acc := Comp;
6380 when N_Parameter_Specification =>
6381 Comp := Parameter_Type (N);
6382 Acc := Comp;
6384 when N_Access_Function_Definition =>
6385 Comp := Result_Definition (N);
6386 Acc := Comp;
6388 when N_Object_Declaration =>
6389 Comp := Object_Definition (N);
6390 Acc := Comp;
6392 when N_Function_Specification =>
6393 Comp := Result_Definition (N);
6394 Acc := Comp;
6396 when others =>
6397 raise Program_Error;
6398 end case;
6400 Spec := Access_To_Subprogram_Definition (Acc);
6402 Decl :=
6403 Make_Full_Type_Declaration (Loc,
6404 Defining_Identifier => Anon,
6405 Type_Definition => Copy_Separate_Tree (Spec));
6407 Mark_Rewrite_Insertion (Decl);
6409 -- In ASIS mode, analyze the profile on the original node, because
6410 -- the separate copy does not provide enough links to recover the
6411 -- original tree. Analysis is limited to type annotations, within
6412 -- a temporary scope that serves as an anonymous subprogram to collect
6413 -- otherwise useless temporaries and itypes.
6415 if ASIS_Mode then
6416 declare
6417 Typ : constant Entity_Id := Make_Temporary (Loc, 'S');
6419 begin
6420 if Nkind (Spec) = N_Access_Function_Definition then
6421 Set_Ekind (Typ, E_Function);
6422 else
6423 Set_Ekind (Typ, E_Procedure);
6424 end if;
6426 Set_Parent (Typ, N);
6427 Set_Scope (Typ, Current_Scope);
6428 Push_Scope (Typ);
6430 -- Nothing to do if procedure is parameterless
6432 if Present (Parameter_Specifications (Spec)) then
6433 Process_Formals (Parameter_Specifications (Spec), Spec);
6434 end if;
6436 if Nkind (Spec) = N_Access_Function_Definition then
6437 declare
6438 Def : constant Node_Id := Result_Definition (Spec);
6440 begin
6441 -- The result might itself be an anonymous access type, so
6442 -- have to recurse.
6444 if Nkind (Def) = N_Access_Definition then
6445 if Present (Access_To_Subprogram_Definition (Def)) then
6446 Set_Etype
6447 (Def,
6448 Replace_Anonymous_Access_To_Protected_Subprogram
6449 (Spec));
6450 else
6451 Find_Type (Subtype_Mark (Def));
6452 end if;
6454 else
6455 Find_Type (Def);
6456 end if;
6457 end;
6458 end if;
6460 End_Scope;
6461 end;
6462 end if;
6464 -- Insert the new declaration in the nearest enclosing scope. If the
6465 -- parent is a body and N is its return type, the declaration belongs
6466 -- in the enclosing scope. Likewise if N is the type of a parameter.
6468 P := Parent (N);
6470 if Nkind (N) = N_Function_Specification
6471 and then Nkind (P) = N_Subprogram_Body
6472 then
6473 P := Parent (P);
6474 elsif Nkind (N) = N_Parameter_Specification
6475 and then Nkind (P) in N_Subprogram_Specification
6476 and then Nkind (Parent (P)) = N_Subprogram_Body
6477 then
6478 P := Parent (Parent (P));
6479 end if;
6481 while Present (P) and then not Has_Declarations (P) loop
6482 P := Parent (P);
6483 end loop;
6485 pragma Assert (Present (P));
6487 if Nkind (P) = N_Package_Specification then
6488 Prepend (Decl, Visible_Declarations (P));
6489 else
6490 Prepend (Decl, Declarations (P));
6491 end if;
6493 -- Replace the anonymous type with an occurrence of the new declaration.
6494 -- In all cases the rewritten node does not have the null-exclusion
6495 -- attribute because (if present) it was already inherited by the
6496 -- anonymous entity (Anon). Thus, in case of components we do not
6497 -- inherit this attribute.
6499 if Nkind (N) = N_Parameter_Specification then
6500 Rewrite (Comp, New_Occurrence_Of (Anon, Loc));
6501 Set_Etype (Defining_Identifier (N), Anon);
6502 Set_Null_Exclusion_Present (N, False);
6504 elsif Nkind (N) = N_Object_Declaration then
6505 Rewrite (Comp, New_Occurrence_Of (Anon, Loc));
6506 Set_Etype (Defining_Identifier (N), Anon);
6508 elsif Nkind (N) = N_Access_Function_Definition then
6509 Rewrite (Comp, New_Occurrence_Of (Anon, Loc));
6511 elsif Nkind (N) = N_Function_Specification then
6512 Rewrite (Comp, New_Occurrence_Of (Anon, Loc));
6513 Set_Etype (Defining_Unit_Name (N), Anon);
6515 else
6516 Rewrite (Comp,
6517 Make_Component_Definition (Loc,
6518 Subtype_Indication => New_Occurrence_Of (Anon, Loc)));
6519 end if;
6521 Mark_Rewrite_Insertion (Comp);
6523 if Nkind_In (N, N_Object_Declaration, N_Access_Function_Definition)
6524 or else (Nkind (Parent (N)) = N_Full_Type_Declaration
6525 and then not Is_Type (Current_Scope))
6526 then
6528 -- Declaration can be analyzed in the current scope.
6530 Analyze (Decl);
6532 else
6533 -- Temporarily remove the current scope (record or subprogram) from
6534 -- the stack to add the new declarations to the enclosing scope.
6535 -- The anonymous entity is an Itype with the proper attributes.
6537 Scope_Stack.Decrement_Last;
6538 Analyze (Decl);
6539 Set_Is_Itype (Anon);
6540 Set_Associated_Node_For_Itype (Anon, N);
6541 Scope_Stack.Append (Curr_Scope);
6542 end if;
6544 Set_Ekind (Anon, E_Anonymous_Access_Protected_Subprogram_Type);
6545 Set_Can_Use_Internal_Rep (Anon, not Always_Compatible_Rep_On_Target);
6546 return Anon;
6547 end Replace_Anonymous_Access_To_Protected_Subprogram;
6549 -------------------------------
6550 -- Build_Derived_Access_Type --
6551 -------------------------------
6553 procedure Build_Derived_Access_Type
6554 (N : Node_Id;
6555 Parent_Type : Entity_Id;
6556 Derived_Type : Entity_Id)
6558 S : constant Node_Id := Subtype_Indication (Type_Definition (N));
6560 Desig_Type : Entity_Id;
6561 Discr : Entity_Id;
6562 Discr_Con_Elist : Elist_Id;
6563 Discr_Con_El : Elmt_Id;
6564 Subt : Entity_Id;
6566 begin
6567 -- Set the designated type so it is available in case this is an access
6568 -- to a self-referential type, e.g. a standard list type with a next
6569 -- pointer. Will be reset after subtype is built.
6571 Set_Directly_Designated_Type
6572 (Derived_Type, Designated_Type (Parent_Type));
6574 Subt := Process_Subtype (S, N);
6576 if Nkind (S) /= N_Subtype_Indication
6577 and then Subt /= Base_Type (Subt)
6578 then
6579 Set_Ekind (Derived_Type, E_Access_Subtype);
6580 end if;
6582 if Ekind (Derived_Type) = E_Access_Subtype then
6583 declare
6584 Pbase : constant Entity_Id := Base_Type (Parent_Type);
6585 Ibase : constant Entity_Id :=
6586 Create_Itype (Ekind (Pbase), N, Derived_Type, 'B');
6587 Svg_Chars : constant Name_Id := Chars (Ibase);
6588 Svg_Next_E : constant Entity_Id := Next_Entity (Ibase);
6590 begin
6591 Copy_Node (Pbase, Ibase);
6593 -- Restore Itype status after Copy_Node
6595 Set_Is_Itype (Ibase);
6596 Set_Associated_Node_For_Itype (Ibase, N);
6598 Set_Chars (Ibase, Svg_Chars);
6599 Set_Next_Entity (Ibase, Svg_Next_E);
6600 Set_Sloc (Ibase, Sloc (Derived_Type));
6601 Set_Scope (Ibase, Scope (Derived_Type));
6602 Set_Freeze_Node (Ibase, Empty);
6603 Set_Is_Frozen (Ibase, False);
6604 Set_Comes_From_Source (Ibase, False);
6605 Set_Is_First_Subtype (Ibase, False);
6607 Set_Etype (Ibase, Pbase);
6608 Set_Etype (Derived_Type, Ibase);
6609 end;
6610 end if;
6612 Set_Directly_Designated_Type
6613 (Derived_Type, Designated_Type (Subt));
6615 Set_Is_Constrained (Derived_Type, Is_Constrained (Subt));
6616 Set_Is_Access_Constant (Derived_Type, Is_Access_Constant (Parent_Type));
6617 Set_Size_Info (Derived_Type, Parent_Type);
6618 Set_RM_Size (Derived_Type, RM_Size (Parent_Type));
6619 Set_Depends_On_Private (Derived_Type,
6620 Has_Private_Component (Derived_Type));
6621 Conditional_Delay (Derived_Type, Subt);
6623 -- Ada 2005 (AI-231): Set the null-exclusion attribute, and verify
6624 -- that it is not redundant.
6626 if Null_Exclusion_Present (Type_Definition (N)) then
6627 Set_Can_Never_Be_Null (Derived_Type);
6629 elsif Can_Never_Be_Null (Parent_Type) then
6630 Set_Can_Never_Be_Null (Derived_Type);
6631 end if;
6633 -- Note: we do not copy the Storage_Size_Variable, since we always go to
6634 -- the root type for this information.
6636 -- Apply range checks to discriminants for derived record case
6637 -- ??? THIS CODE SHOULD NOT BE HERE REALLY.
6639 Desig_Type := Designated_Type (Derived_Type);
6641 if Is_Composite_Type (Desig_Type)
6642 and then (not Is_Array_Type (Desig_Type))
6643 and then Has_Discriminants (Desig_Type)
6644 and then Base_Type (Desig_Type) /= Desig_Type
6645 then
6646 Discr_Con_Elist := Discriminant_Constraint (Desig_Type);
6647 Discr_Con_El := First_Elmt (Discr_Con_Elist);
6649 Discr := First_Discriminant (Base_Type (Desig_Type));
6650 while Present (Discr_Con_El) loop
6651 Apply_Range_Check (Node (Discr_Con_El), Etype (Discr));
6652 Next_Elmt (Discr_Con_El);
6653 Next_Discriminant (Discr);
6654 end loop;
6655 end if;
6656 end Build_Derived_Access_Type;
6658 ------------------------------
6659 -- Build_Derived_Array_Type --
6660 ------------------------------
6662 procedure Build_Derived_Array_Type
6663 (N : Node_Id;
6664 Parent_Type : Entity_Id;
6665 Derived_Type : Entity_Id)
6667 Loc : constant Source_Ptr := Sloc (N);
6668 Tdef : constant Node_Id := Type_Definition (N);
6669 Indic : constant Node_Id := Subtype_Indication (Tdef);
6670 Parent_Base : constant Entity_Id := Base_Type (Parent_Type);
6671 Implicit_Base : Entity_Id := Empty;
6672 New_Indic : Node_Id;
6674 procedure Make_Implicit_Base;
6675 -- If the parent subtype is constrained, the derived type is a subtype
6676 -- of an implicit base type derived from the parent base.
6678 ------------------------
6679 -- Make_Implicit_Base --
6680 ------------------------
6682 procedure Make_Implicit_Base is
6683 begin
6684 Implicit_Base :=
6685 Create_Itype (Ekind (Parent_Base), N, Derived_Type, 'B');
6687 Set_Ekind (Implicit_Base, Ekind (Parent_Base));
6688 Set_Etype (Implicit_Base, Parent_Base);
6690 Copy_Array_Subtype_Attributes (Implicit_Base, Parent_Base);
6691 Copy_Array_Base_Type_Attributes (Implicit_Base, Parent_Base);
6693 Set_Has_Delayed_Freeze (Implicit_Base, True);
6694 end Make_Implicit_Base;
6696 -- Start of processing for Build_Derived_Array_Type
6698 begin
6699 if not Is_Constrained (Parent_Type) then
6700 if Nkind (Indic) /= N_Subtype_Indication then
6701 Set_Ekind (Derived_Type, E_Array_Type);
6703 Copy_Array_Subtype_Attributes (Derived_Type, Parent_Type);
6704 Copy_Array_Base_Type_Attributes (Derived_Type, Parent_Type);
6706 Set_Has_Delayed_Freeze (Derived_Type, True);
6708 else
6709 Make_Implicit_Base;
6710 Set_Etype (Derived_Type, Implicit_Base);
6712 New_Indic :=
6713 Make_Subtype_Declaration (Loc,
6714 Defining_Identifier => Derived_Type,
6715 Subtype_Indication =>
6716 Make_Subtype_Indication (Loc,
6717 Subtype_Mark => New_Occurrence_Of (Implicit_Base, Loc),
6718 Constraint => Constraint (Indic)));
6720 Rewrite (N, New_Indic);
6721 Analyze (N);
6722 end if;
6724 else
6725 if Nkind (Indic) /= N_Subtype_Indication then
6726 Make_Implicit_Base;
6728 Set_Ekind (Derived_Type, Ekind (Parent_Type));
6729 Set_Etype (Derived_Type, Implicit_Base);
6730 Copy_Array_Subtype_Attributes (Derived_Type, Parent_Type);
6732 else
6733 Error_Msg_N ("illegal constraint on constrained type", Indic);
6734 end if;
6735 end if;
6737 -- If parent type is not a derived type itself, and is declared in
6738 -- closed scope (e.g. a subprogram), then we must explicitly introduce
6739 -- the new type's concatenation operator since Derive_Subprograms
6740 -- will not inherit the parent's operator. If the parent type is
6741 -- unconstrained, the operator is of the unconstrained base type.
6743 if Number_Dimensions (Parent_Type) = 1
6744 and then not Is_Limited_Type (Parent_Type)
6745 and then not Is_Derived_Type (Parent_Type)
6746 and then not Is_Package_Or_Generic_Package
6747 (Scope (Base_Type (Parent_Type)))
6748 then
6749 if not Is_Constrained (Parent_Type)
6750 and then Is_Constrained (Derived_Type)
6751 then
6752 New_Concatenation_Op (Implicit_Base);
6753 else
6754 New_Concatenation_Op (Derived_Type);
6755 end if;
6756 end if;
6757 end Build_Derived_Array_Type;
6759 -----------------------------------
6760 -- Build_Derived_Concurrent_Type --
6761 -----------------------------------
6763 procedure Build_Derived_Concurrent_Type
6764 (N : Node_Id;
6765 Parent_Type : Entity_Id;
6766 Derived_Type : Entity_Id)
6768 Loc : constant Source_Ptr := Sloc (N);
6770 Corr_Record : constant Entity_Id := Make_Temporary (Loc, 'C');
6771 Corr_Decl : Node_Id;
6772 Corr_Decl_Needed : Boolean;
6773 -- If the derived type has fewer discriminants than its parent, the
6774 -- corresponding record is also a derived type, in order to account for
6775 -- the bound discriminants. We create a full type declaration for it in
6776 -- this case.
6778 Constraint_Present : constant Boolean :=
6779 Nkind (Subtype_Indication (Type_Definition (N))) =
6780 N_Subtype_Indication;
6782 D_Constraint : Node_Id;
6783 New_Constraint : Elist_Id := No_Elist;
6784 Old_Disc : Entity_Id;
6785 New_Disc : Entity_Id;
6786 New_N : Node_Id;
6788 begin
6789 Set_Stored_Constraint (Derived_Type, No_Elist);
6790 Corr_Decl_Needed := False;
6791 Old_Disc := Empty;
6793 if Present (Discriminant_Specifications (N))
6794 and then Constraint_Present
6795 then
6796 Old_Disc := First_Discriminant (Parent_Type);
6797 New_Disc := First (Discriminant_Specifications (N));
6798 while Present (New_Disc) and then Present (Old_Disc) loop
6799 Next_Discriminant (Old_Disc);
6800 Next (New_Disc);
6801 end loop;
6802 end if;
6804 if Present (Old_Disc) and then Expander_Active then
6806 -- The new type has fewer discriminants, so we need to create a new
6807 -- corresponding record, which is derived from the corresponding
6808 -- record of the parent, and has a stored constraint that captures
6809 -- the values of the discriminant constraints. The corresponding
6810 -- record is needed only if expander is active and code generation is
6811 -- enabled.
6813 -- The type declaration for the derived corresponding record has the
6814 -- same discriminant part and constraints as the current declaration.
6815 -- Copy the unanalyzed tree to build declaration.
6817 Corr_Decl_Needed := True;
6818 New_N := Copy_Separate_Tree (N);
6820 Corr_Decl :=
6821 Make_Full_Type_Declaration (Loc,
6822 Defining_Identifier => Corr_Record,
6823 Discriminant_Specifications =>
6824 Discriminant_Specifications (New_N),
6825 Type_Definition =>
6826 Make_Derived_Type_Definition (Loc,
6827 Subtype_Indication =>
6828 Make_Subtype_Indication (Loc,
6829 Subtype_Mark =>
6830 New_Occurrence_Of
6831 (Corresponding_Record_Type (Parent_Type), Loc),
6832 Constraint =>
6833 Constraint
6834 (Subtype_Indication (Type_Definition (New_N))))));
6835 end if;
6837 -- Copy Storage_Size and Relative_Deadline variables if task case
6839 if Is_Task_Type (Parent_Type) then
6840 Set_Storage_Size_Variable (Derived_Type,
6841 Storage_Size_Variable (Parent_Type));
6842 Set_Relative_Deadline_Variable (Derived_Type,
6843 Relative_Deadline_Variable (Parent_Type));
6844 end if;
6846 if Present (Discriminant_Specifications (N)) then
6847 Push_Scope (Derived_Type);
6848 Check_Or_Process_Discriminants (N, Derived_Type);
6850 if Constraint_Present then
6851 New_Constraint :=
6852 Expand_To_Stored_Constraint
6853 (Parent_Type,
6854 Build_Discriminant_Constraints
6855 (Parent_Type,
6856 Subtype_Indication (Type_Definition (N)), True));
6857 end if;
6859 End_Scope;
6861 elsif Constraint_Present then
6863 -- Build constrained subtype, copying the constraint, and derive
6864 -- from it to create a derived constrained type.
6866 declare
6867 Loc : constant Source_Ptr := Sloc (N);
6868 Anon : constant Entity_Id :=
6869 Make_Defining_Identifier (Loc,
6870 Chars => New_External_Name (Chars (Derived_Type), 'T'));
6871 Decl : Node_Id;
6873 begin
6874 Decl :=
6875 Make_Subtype_Declaration (Loc,
6876 Defining_Identifier => Anon,
6877 Subtype_Indication =>
6878 New_Copy_Tree (Subtype_Indication (Type_Definition (N))));
6879 Insert_Before (N, Decl);
6880 Analyze (Decl);
6882 Rewrite (Subtype_Indication (Type_Definition (N)),
6883 New_Occurrence_Of (Anon, Loc));
6884 Set_Analyzed (Derived_Type, False);
6885 Analyze (N);
6886 return;
6887 end;
6888 end if;
6890 -- By default, operations and private data are inherited from parent.
6891 -- However, in the presence of bound discriminants, a new corresponding
6892 -- record will be created, see below.
6894 Set_Has_Discriminants
6895 (Derived_Type, Has_Discriminants (Parent_Type));
6896 Set_Corresponding_Record_Type
6897 (Derived_Type, Corresponding_Record_Type (Parent_Type));
6899 -- Is_Constrained is set according the parent subtype, but is set to
6900 -- False if the derived type is declared with new discriminants.
6902 Set_Is_Constrained
6903 (Derived_Type,
6904 (Is_Constrained (Parent_Type) or else Constraint_Present)
6905 and then not Present (Discriminant_Specifications (N)));
6907 if Constraint_Present then
6908 if not Has_Discriminants (Parent_Type) then
6909 Error_Msg_N ("untagged parent must have discriminants", N);
6911 elsif Present (Discriminant_Specifications (N)) then
6913 -- Verify that new discriminants are used to constrain old ones
6915 D_Constraint :=
6916 First
6917 (Constraints
6918 (Constraint (Subtype_Indication (Type_Definition (N)))));
6920 Old_Disc := First_Discriminant (Parent_Type);
6922 while Present (D_Constraint) loop
6923 if Nkind (D_Constraint) /= N_Discriminant_Association then
6925 -- Positional constraint. If it is a reference to a new
6926 -- discriminant, it constrains the corresponding old one.
6928 if Nkind (D_Constraint) = N_Identifier then
6929 New_Disc := First_Discriminant (Derived_Type);
6930 while Present (New_Disc) loop
6931 exit when Chars (New_Disc) = Chars (D_Constraint);
6932 Next_Discriminant (New_Disc);
6933 end loop;
6935 if Present (New_Disc) then
6936 Set_Corresponding_Discriminant (New_Disc, Old_Disc);
6937 end if;
6938 end if;
6940 Next_Discriminant (Old_Disc);
6942 -- if this is a named constraint, search by name for the old
6943 -- discriminants constrained by the new one.
6945 elsif Nkind (Expression (D_Constraint)) = N_Identifier then
6947 -- Find new discriminant with that name
6949 New_Disc := First_Discriminant (Derived_Type);
6950 while Present (New_Disc) loop
6951 exit when
6952 Chars (New_Disc) = Chars (Expression (D_Constraint));
6953 Next_Discriminant (New_Disc);
6954 end loop;
6956 if Present (New_Disc) then
6958 -- Verify that new discriminant renames some discriminant
6959 -- of the parent type, and associate the new discriminant
6960 -- with one or more old ones that it renames.
6962 declare
6963 Selector : Node_Id;
6965 begin
6966 Selector := First (Selector_Names (D_Constraint));
6967 while Present (Selector) loop
6968 Old_Disc := First_Discriminant (Parent_Type);
6969 while Present (Old_Disc) loop
6970 exit when Chars (Old_Disc) = Chars (Selector);
6971 Next_Discriminant (Old_Disc);
6972 end loop;
6974 if Present (Old_Disc) then
6975 Set_Corresponding_Discriminant
6976 (New_Disc, Old_Disc);
6977 end if;
6979 Next (Selector);
6980 end loop;
6981 end;
6982 end if;
6983 end if;
6985 Next (D_Constraint);
6986 end loop;
6988 New_Disc := First_Discriminant (Derived_Type);
6989 while Present (New_Disc) loop
6990 if No (Corresponding_Discriminant (New_Disc)) then
6991 Error_Msg_NE
6992 ("new discriminant& must constrain old one", N, New_Disc);
6994 elsif not
6995 Subtypes_Statically_Compatible
6996 (Etype (New_Disc),
6997 Etype (Corresponding_Discriminant (New_Disc)))
6998 then
6999 Error_Msg_NE
7000 ("& not statically compatible with parent discriminant",
7001 N, New_Disc);
7002 end if;
7004 Next_Discriminant (New_Disc);
7005 end loop;
7006 end if;
7008 elsif Present (Discriminant_Specifications (N)) then
7009 Error_Msg_N
7010 ("missing discriminant constraint in untagged derivation", N);
7011 end if;
7013 -- The entity chain of the derived type includes the new discriminants
7014 -- but shares operations with the parent.
7016 if Present (Discriminant_Specifications (N)) then
7017 Old_Disc := First_Discriminant (Parent_Type);
7018 while Present (Old_Disc) loop
7019 if No (Next_Entity (Old_Disc))
7020 or else Ekind (Next_Entity (Old_Disc)) /= E_Discriminant
7021 then
7022 Set_Next_Entity
7023 (Last_Entity (Derived_Type), Next_Entity (Old_Disc));
7024 exit;
7025 end if;
7027 Next_Discriminant (Old_Disc);
7028 end loop;
7030 else
7031 Set_First_Entity (Derived_Type, First_Entity (Parent_Type));
7032 if Has_Discriminants (Parent_Type) then
7033 Set_Is_Constrained (Derived_Type, Is_Constrained (Parent_Type));
7034 Set_Discriminant_Constraint (
7035 Derived_Type, Discriminant_Constraint (Parent_Type));
7036 end if;
7037 end if;
7039 Set_Last_Entity (Derived_Type, Last_Entity (Parent_Type));
7041 Set_Has_Completion (Derived_Type);
7043 if Corr_Decl_Needed then
7044 Set_Stored_Constraint (Derived_Type, New_Constraint);
7045 Insert_After (N, Corr_Decl);
7046 Analyze (Corr_Decl);
7047 Set_Corresponding_Record_Type (Derived_Type, Corr_Record);
7048 end if;
7049 end Build_Derived_Concurrent_Type;
7051 ------------------------------------
7052 -- Build_Derived_Enumeration_Type --
7053 ------------------------------------
7055 procedure Build_Derived_Enumeration_Type
7056 (N : Node_Id;
7057 Parent_Type : Entity_Id;
7058 Derived_Type : Entity_Id)
7060 Loc : constant Source_Ptr := Sloc (N);
7061 Def : constant Node_Id := Type_Definition (N);
7062 Indic : constant Node_Id := Subtype_Indication (Def);
7063 Implicit_Base : Entity_Id;
7064 Literal : Entity_Id;
7065 New_Lit : Entity_Id;
7066 Literals_List : List_Id;
7067 Type_Decl : Node_Id;
7068 Hi, Lo : Node_Id;
7069 Rang_Expr : Node_Id;
7071 begin
7072 -- Since types Standard.Character and Standard.[Wide_]Wide_Character do
7073 -- not have explicit literals lists we need to process types derived
7074 -- from them specially. This is handled by Derived_Standard_Character.
7075 -- If the parent type is a generic type, there are no literals either,
7076 -- and we construct the same skeletal representation as for the generic
7077 -- parent type.
7079 if Is_Standard_Character_Type (Parent_Type) then
7080 Derived_Standard_Character (N, Parent_Type, Derived_Type);
7082 elsif Is_Generic_Type (Root_Type (Parent_Type)) then
7083 declare
7084 Lo : Node_Id;
7085 Hi : Node_Id;
7087 begin
7088 if Nkind (Indic) /= N_Subtype_Indication then
7089 Lo :=
7090 Make_Attribute_Reference (Loc,
7091 Attribute_Name => Name_First,
7092 Prefix => New_Occurrence_Of (Derived_Type, Loc));
7093 Set_Etype (Lo, Derived_Type);
7095 Hi :=
7096 Make_Attribute_Reference (Loc,
7097 Attribute_Name => Name_Last,
7098 Prefix => New_Occurrence_Of (Derived_Type, Loc));
7099 Set_Etype (Hi, Derived_Type);
7101 Set_Scalar_Range (Derived_Type,
7102 Make_Range (Loc,
7103 Low_Bound => Lo,
7104 High_Bound => Hi));
7105 else
7107 -- Analyze subtype indication and verify compatibility
7108 -- with parent type.
7110 if Base_Type (Process_Subtype (Indic, N)) /=
7111 Base_Type (Parent_Type)
7112 then
7113 Error_Msg_N
7114 ("illegal constraint for formal discrete type", N);
7115 end if;
7116 end if;
7117 end;
7119 else
7120 -- If a constraint is present, analyze the bounds to catch
7121 -- premature usage of the derived literals.
7123 if Nkind (Indic) = N_Subtype_Indication
7124 and then Nkind (Range_Expression (Constraint (Indic))) = N_Range
7125 then
7126 Analyze (Low_Bound (Range_Expression (Constraint (Indic))));
7127 Analyze (High_Bound (Range_Expression (Constraint (Indic))));
7128 end if;
7130 -- Introduce an implicit base type for the derived type even if there
7131 -- is no constraint attached to it, since this seems closer to the
7132 -- Ada semantics. Build a full type declaration tree for the derived
7133 -- type using the implicit base type as the defining identifier. The
7134 -- build a subtype declaration tree which applies the constraint (if
7135 -- any) have it replace the derived type declaration.
7137 Literal := First_Literal (Parent_Type);
7138 Literals_List := New_List;
7139 while Present (Literal)
7140 and then Ekind (Literal) = E_Enumeration_Literal
7141 loop
7142 -- Literals of the derived type have the same representation as
7143 -- those of the parent type, but this representation can be
7144 -- overridden by an explicit representation clause. Indicate
7145 -- that there is no explicit representation given yet. These
7146 -- derived literals are implicit operations of the new type,
7147 -- and can be overridden by explicit ones.
7149 if Nkind (Literal) = N_Defining_Character_Literal then
7150 New_Lit :=
7151 Make_Defining_Character_Literal (Loc, Chars (Literal));
7152 else
7153 New_Lit := Make_Defining_Identifier (Loc, Chars (Literal));
7154 end if;
7156 Set_Ekind (New_Lit, E_Enumeration_Literal);
7157 Set_Enumeration_Pos (New_Lit, Enumeration_Pos (Literal));
7158 Set_Enumeration_Rep (New_Lit, Enumeration_Rep (Literal));
7159 Set_Enumeration_Rep_Expr (New_Lit, Empty);
7160 Set_Alias (New_Lit, Literal);
7161 Set_Is_Known_Valid (New_Lit, True);
7163 Append (New_Lit, Literals_List);
7164 Next_Literal (Literal);
7165 end loop;
7167 Implicit_Base :=
7168 Make_Defining_Identifier (Sloc (Derived_Type),
7169 Chars => New_External_Name (Chars (Derived_Type), 'B'));
7171 -- Indicate the proper nature of the derived type. This must be done
7172 -- before analysis of the literals, to recognize cases when a literal
7173 -- may be hidden by a previous explicit function definition (cf.
7174 -- c83031a).
7176 Set_Ekind (Derived_Type, E_Enumeration_Subtype);
7177 Set_Etype (Derived_Type, Implicit_Base);
7179 Type_Decl :=
7180 Make_Full_Type_Declaration (Loc,
7181 Defining_Identifier => Implicit_Base,
7182 Discriminant_Specifications => No_List,
7183 Type_Definition =>
7184 Make_Enumeration_Type_Definition (Loc, Literals_List));
7186 Mark_Rewrite_Insertion (Type_Decl);
7187 Insert_Before (N, Type_Decl);
7188 Analyze (Type_Decl);
7190 -- The anonymous base now has a full declaration, but this base
7191 -- is not a first subtype.
7193 Set_Is_First_Subtype (Implicit_Base, False);
7195 -- After the implicit base is analyzed its Etype needs to be changed
7196 -- to reflect the fact that it is derived from the parent type which
7197 -- was ignored during analysis. We also set the size at this point.
7199 Set_Etype (Implicit_Base, Parent_Type);
7201 Set_Size_Info (Implicit_Base, Parent_Type);
7202 Set_RM_Size (Implicit_Base, RM_Size (Parent_Type));
7203 Set_First_Rep_Item (Implicit_Base, First_Rep_Item (Parent_Type));
7205 -- Copy other flags from parent type
7207 Set_Has_Non_Standard_Rep
7208 (Implicit_Base, Has_Non_Standard_Rep
7209 (Parent_Type));
7210 Set_Has_Pragma_Ordered
7211 (Implicit_Base, Has_Pragma_Ordered
7212 (Parent_Type));
7213 Set_Has_Delayed_Freeze (Implicit_Base);
7215 -- Process the subtype indication including a validation check on the
7216 -- constraint, if any. If a constraint is given, its bounds must be
7217 -- implicitly converted to the new type.
7219 if Nkind (Indic) = N_Subtype_Indication then
7220 declare
7221 R : constant Node_Id :=
7222 Range_Expression (Constraint (Indic));
7224 begin
7225 if Nkind (R) = N_Range then
7226 Hi := Build_Scalar_Bound
7227 (High_Bound (R), Parent_Type, Implicit_Base);
7228 Lo := Build_Scalar_Bound
7229 (Low_Bound (R), Parent_Type, Implicit_Base);
7231 else
7232 -- Constraint is a Range attribute. Replace with explicit
7233 -- mention of the bounds of the prefix, which must be a
7234 -- subtype.
7236 Analyze (Prefix (R));
7237 Hi :=
7238 Convert_To (Implicit_Base,
7239 Make_Attribute_Reference (Loc,
7240 Attribute_Name => Name_Last,
7241 Prefix =>
7242 New_Occurrence_Of (Entity (Prefix (R)), Loc)));
7244 Lo :=
7245 Convert_To (Implicit_Base,
7246 Make_Attribute_Reference (Loc,
7247 Attribute_Name => Name_First,
7248 Prefix =>
7249 New_Occurrence_Of (Entity (Prefix (R)), Loc)));
7250 end if;
7251 end;
7253 else
7254 Hi :=
7255 Build_Scalar_Bound
7256 (Type_High_Bound (Parent_Type),
7257 Parent_Type, Implicit_Base);
7258 Lo :=
7259 Build_Scalar_Bound
7260 (Type_Low_Bound (Parent_Type),
7261 Parent_Type, Implicit_Base);
7262 end if;
7264 Rang_Expr :=
7265 Make_Range (Loc,
7266 Low_Bound => Lo,
7267 High_Bound => Hi);
7269 -- If we constructed a default range for the case where no range
7270 -- was given, then the expressions in the range must not freeze
7271 -- since they do not correspond to expressions in the source.
7272 -- However, if the type inherits predicates the expressions will
7273 -- be elaborated earlier and must freeze.
7275 if Nkind (Indic) /= N_Subtype_Indication
7276 and then not Has_Predicates (Derived_Type)
7277 then
7278 Set_Must_Not_Freeze (Lo);
7279 Set_Must_Not_Freeze (Hi);
7280 Set_Must_Not_Freeze (Rang_Expr);
7281 end if;
7283 Rewrite (N,
7284 Make_Subtype_Declaration (Loc,
7285 Defining_Identifier => Derived_Type,
7286 Subtype_Indication =>
7287 Make_Subtype_Indication (Loc,
7288 Subtype_Mark => New_Occurrence_Of (Implicit_Base, Loc),
7289 Constraint =>
7290 Make_Range_Constraint (Loc,
7291 Range_Expression => Rang_Expr))));
7293 Analyze (N);
7295 -- Propagate the aspects from the original type declaration to the
7296 -- declaration of the implicit base.
7298 Move_Aspects (From => Original_Node (N), To => Type_Decl);
7300 -- Apply a range check. Since this range expression doesn't have an
7301 -- Etype, we have to specifically pass the Source_Typ parameter. Is
7302 -- this right???
7304 if Nkind (Indic) = N_Subtype_Indication then
7305 Apply_Range_Check
7306 (Range_Expression (Constraint (Indic)), Parent_Type,
7307 Source_Typ => Entity (Subtype_Mark (Indic)));
7308 end if;
7309 end if;
7310 end Build_Derived_Enumeration_Type;
7312 --------------------------------
7313 -- Build_Derived_Numeric_Type --
7314 --------------------------------
7316 procedure Build_Derived_Numeric_Type
7317 (N : Node_Id;
7318 Parent_Type : Entity_Id;
7319 Derived_Type : Entity_Id)
7321 Loc : constant Source_Ptr := Sloc (N);
7322 Tdef : constant Node_Id := Type_Definition (N);
7323 Indic : constant Node_Id := Subtype_Indication (Tdef);
7324 Parent_Base : constant Entity_Id := Base_Type (Parent_Type);
7325 No_Constraint : constant Boolean := Nkind (Indic) /=
7326 N_Subtype_Indication;
7327 Implicit_Base : Entity_Id;
7329 Lo : Node_Id;
7330 Hi : Node_Id;
7332 begin
7333 -- Process the subtype indication including a validation check on
7334 -- the constraint if any.
7336 Discard_Node (Process_Subtype (Indic, N));
7338 -- Introduce an implicit base type for the derived type even if there
7339 -- is no constraint attached to it, since this seems closer to the Ada
7340 -- semantics.
7342 Implicit_Base :=
7343 Create_Itype (Ekind (Parent_Base), N, Derived_Type, 'B');
7345 Set_Etype (Implicit_Base, Parent_Base);
7346 Set_Ekind (Implicit_Base, Ekind (Parent_Base));
7347 Set_Size_Info (Implicit_Base, Parent_Base);
7348 Set_First_Rep_Item (Implicit_Base, First_Rep_Item (Parent_Base));
7349 Set_Parent (Implicit_Base, Parent (Derived_Type));
7350 Set_Is_Known_Valid (Implicit_Base, Is_Known_Valid (Parent_Base));
7352 -- Set RM Size for discrete type or decimal fixed-point type
7353 -- Ordinary fixed-point is excluded, why???
7355 if Is_Discrete_Type (Parent_Base)
7356 or else Is_Decimal_Fixed_Point_Type (Parent_Base)
7357 then
7358 Set_RM_Size (Implicit_Base, RM_Size (Parent_Base));
7359 end if;
7361 Set_Has_Delayed_Freeze (Implicit_Base);
7363 Lo := New_Copy_Tree (Type_Low_Bound (Parent_Base));
7364 Hi := New_Copy_Tree (Type_High_Bound (Parent_Base));
7366 Set_Scalar_Range (Implicit_Base,
7367 Make_Range (Loc,
7368 Low_Bound => Lo,
7369 High_Bound => Hi));
7371 if Has_Infinities (Parent_Base) then
7372 Set_Includes_Infinities (Scalar_Range (Implicit_Base));
7373 end if;
7375 -- The Derived_Type, which is the entity of the declaration, is a
7376 -- subtype of the implicit base. Its Ekind is a subtype, even in the
7377 -- absence of an explicit constraint.
7379 Set_Etype (Derived_Type, Implicit_Base);
7381 -- If we did not have a constraint, then the Ekind is set from the
7382 -- parent type (otherwise Process_Subtype has set the bounds)
7384 if No_Constraint then
7385 Set_Ekind (Derived_Type, Subtype_Kind (Ekind (Parent_Type)));
7386 end if;
7388 -- If we did not have a range constraint, then set the range from the
7389 -- parent type. Otherwise, the Process_Subtype call has set the bounds.
7391 if No_Constraint or else not Has_Range_Constraint (Indic) then
7392 Set_Scalar_Range (Derived_Type,
7393 Make_Range (Loc,
7394 Low_Bound => New_Copy_Tree (Type_Low_Bound (Parent_Type)),
7395 High_Bound => New_Copy_Tree (Type_High_Bound (Parent_Type))));
7396 Set_Is_Constrained (Derived_Type, Is_Constrained (Parent_Type));
7398 if Has_Infinities (Parent_Type) then
7399 Set_Includes_Infinities (Scalar_Range (Derived_Type));
7400 end if;
7402 Set_Is_Known_Valid (Derived_Type, Is_Known_Valid (Parent_Type));
7403 end if;
7405 Set_Is_Descendant_Of_Address (Derived_Type,
7406 Is_Descendant_Of_Address (Parent_Type));
7407 Set_Is_Descendant_Of_Address (Implicit_Base,
7408 Is_Descendant_Of_Address (Parent_Type));
7410 -- Set remaining type-specific fields, depending on numeric type
7412 if Is_Modular_Integer_Type (Parent_Type) then
7413 Set_Modulus (Implicit_Base, Modulus (Parent_Base));
7415 Set_Non_Binary_Modulus
7416 (Implicit_Base, Non_Binary_Modulus (Parent_Base));
7418 Set_Is_Known_Valid
7419 (Implicit_Base, Is_Known_Valid (Parent_Base));
7421 elsif Is_Floating_Point_Type (Parent_Type) then
7423 -- Digits of base type is always copied from the digits value of
7424 -- the parent base type, but the digits of the derived type will
7425 -- already have been set if there was a constraint present.
7427 Set_Digits_Value (Implicit_Base, Digits_Value (Parent_Base));
7428 Set_Float_Rep (Implicit_Base, Float_Rep (Parent_Base));
7430 if No_Constraint then
7431 Set_Digits_Value (Derived_Type, Digits_Value (Parent_Type));
7432 end if;
7434 elsif Is_Fixed_Point_Type (Parent_Type) then
7436 -- Small of base type and derived type are always copied from the
7437 -- parent base type, since smalls never change. The delta of the
7438 -- base type is also copied from the parent base type. However the
7439 -- delta of the derived type will have been set already if a
7440 -- constraint was present.
7442 Set_Small_Value (Derived_Type, Small_Value (Parent_Base));
7443 Set_Small_Value (Implicit_Base, Small_Value (Parent_Base));
7444 Set_Delta_Value (Implicit_Base, Delta_Value (Parent_Base));
7446 if No_Constraint then
7447 Set_Delta_Value (Derived_Type, Delta_Value (Parent_Type));
7448 end if;
7450 -- The scale and machine radix in the decimal case are always
7451 -- copied from the parent base type.
7453 if Is_Decimal_Fixed_Point_Type (Parent_Type) then
7454 Set_Scale_Value (Derived_Type, Scale_Value (Parent_Base));
7455 Set_Scale_Value (Implicit_Base, Scale_Value (Parent_Base));
7457 Set_Machine_Radix_10
7458 (Derived_Type, Machine_Radix_10 (Parent_Base));
7459 Set_Machine_Radix_10
7460 (Implicit_Base, Machine_Radix_10 (Parent_Base));
7462 Set_Digits_Value (Implicit_Base, Digits_Value (Parent_Base));
7464 if No_Constraint then
7465 Set_Digits_Value (Derived_Type, Digits_Value (Parent_Base));
7467 else
7468 -- the analysis of the subtype_indication sets the
7469 -- digits value of the derived type.
7471 null;
7472 end if;
7473 end if;
7474 end if;
7476 if Is_Integer_Type (Parent_Type) then
7477 Set_Has_Shift_Operator
7478 (Implicit_Base, Has_Shift_Operator (Parent_Type));
7479 end if;
7481 -- The type of the bounds is that of the parent type, and they
7482 -- must be converted to the derived type.
7484 Convert_Scalar_Bounds (N, Parent_Type, Derived_Type, Loc);
7486 -- The implicit_base should be frozen when the derived type is frozen,
7487 -- but note that it is used in the conversions of the bounds. For fixed
7488 -- types we delay the determination of the bounds until the proper
7489 -- freezing point. For other numeric types this is rejected by GCC, for
7490 -- reasons that are currently unclear (???), so we choose to freeze the
7491 -- implicit base now. In the case of integers and floating point types
7492 -- this is harmless because subsequent representation clauses cannot
7493 -- affect anything, but it is still baffling that we cannot use the
7494 -- same mechanism for all derived numeric types.
7496 -- There is a further complication: actually some representation
7497 -- clauses can affect the implicit base type. For example, attribute
7498 -- definition clauses for stream-oriented attributes need to set the
7499 -- corresponding TSS entries on the base type, and this normally
7500 -- cannot be done after the base type is frozen, so the circuitry in
7501 -- Sem_Ch13.New_Stream_Subprogram must account for this possibility
7502 -- and not use Set_TSS in this case.
7504 -- There are also consequences for the case of delayed representation
7505 -- aspects for some cases. For example, a Size aspect is delayed and
7506 -- should not be evaluated to the freeze point. This early freezing
7507 -- means that the size attribute evaluation happens too early???
7509 if Is_Fixed_Point_Type (Parent_Type) then
7510 Conditional_Delay (Implicit_Base, Parent_Type);
7511 else
7512 Freeze_Before (N, Implicit_Base);
7513 end if;
7514 end Build_Derived_Numeric_Type;
7516 --------------------------------
7517 -- Build_Derived_Private_Type --
7518 --------------------------------
7520 procedure Build_Derived_Private_Type
7521 (N : Node_Id;
7522 Parent_Type : Entity_Id;
7523 Derived_Type : Entity_Id;
7524 Is_Completion : Boolean;
7525 Derive_Subps : Boolean := True)
7527 Loc : constant Source_Ptr := Sloc (N);
7528 Par_Base : constant Entity_Id := Base_Type (Parent_Type);
7529 Par_Scope : constant Entity_Id := Scope (Par_Base);
7530 Full_N : constant Node_Id := New_Copy_Tree (N);
7531 Full_Der : Entity_Id := New_Copy (Derived_Type);
7532 Full_P : Entity_Id;
7534 procedure Build_Full_Derivation;
7535 -- Build full derivation, i.e. derive from the full view
7537 procedure Copy_And_Build;
7538 -- Copy derived type declaration, replace parent with its full view,
7539 -- and build derivation
7541 ---------------------------
7542 -- Build_Full_Derivation --
7543 ---------------------------
7545 procedure Build_Full_Derivation is
7546 begin
7547 -- If parent scope is not open, install the declarations
7549 if not In_Open_Scopes (Par_Scope) then
7550 Install_Private_Declarations (Par_Scope);
7551 Install_Visible_Declarations (Par_Scope);
7552 Copy_And_Build;
7553 Uninstall_Declarations (Par_Scope);
7555 -- If parent scope is open and in another unit, and parent has a
7556 -- completion, then the derivation is taking place in the visible
7557 -- part of a child unit. In that case retrieve the full view of
7558 -- the parent momentarily.
7560 elsif not In_Same_Source_Unit (N, Parent_Type) then
7561 Full_P := Full_View (Parent_Type);
7562 Exchange_Declarations (Parent_Type);
7563 Copy_And_Build;
7564 Exchange_Declarations (Full_P);
7566 -- Otherwise it is a local derivation
7568 else
7569 Copy_And_Build;
7570 end if;
7571 end Build_Full_Derivation;
7573 --------------------
7574 -- Copy_And_Build --
7575 --------------------
7577 procedure Copy_And_Build is
7578 Full_Parent : Entity_Id := Parent_Type;
7580 begin
7581 -- If the parent is itself derived from another private type,
7582 -- installing the private declarations has not affected its
7583 -- privacy status, so use its own full view explicitly.
7585 if Is_Private_Type (Full_Parent)
7586 and then Present (Full_View (Full_Parent))
7587 then
7588 Full_Parent := Full_View (Full_Parent);
7589 end if;
7591 -- And its underlying full view if necessary
7593 if Is_Private_Type (Full_Parent)
7594 and then Present (Underlying_Full_View (Full_Parent))
7595 then
7596 Full_Parent := Underlying_Full_View (Full_Parent);
7597 end if;
7599 -- For record, access and most enumeration types, derivation from
7600 -- the full view requires a fully-fledged declaration. In the other
7601 -- cases, just use an itype.
7603 if Ekind (Full_Parent) in Record_Kind
7604 or else Ekind (Full_Parent) in Access_Kind
7605 or else
7606 (Ekind (Full_Parent) in Enumeration_Kind
7607 and then not Is_Standard_Character_Type (Full_Parent)
7608 and then not Is_Generic_Type (Root_Type (Full_Parent)))
7609 then
7610 -- Copy and adjust declaration to provide a completion for what
7611 -- is originally a private declaration. Indicate that full view
7612 -- is internally generated.
7614 Set_Comes_From_Source (Full_N, False);
7615 Set_Comes_From_Source (Full_Der, False);
7616 Set_Parent (Full_Der, Full_N);
7617 Set_Defining_Identifier (Full_N, Full_Der);
7619 -- If there are no constraints, adjust the subtype mark
7621 if Nkind (Subtype_Indication (Type_Definition (Full_N))) /=
7622 N_Subtype_Indication
7623 then
7624 Set_Subtype_Indication
7625 (Type_Definition (Full_N),
7626 New_Occurrence_Of (Full_Parent, Sloc (Full_N)));
7627 end if;
7629 Insert_After (N, Full_N);
7631 -- Build full view of derived type from full view of parent which
7632 -- is now installed. Subprograms have been derived on the partial
7633 -- view, the completion does not derive them anew.
7635 if Ekind (Full_Parent) in Record_Kind then
7637 -- If parent type is tagged, the completion inherits the proper
7638 -- primitive operations.
7640 if Is_Tagged_Type (Parent_Type) then
7641 Build_Derived_Record_Type
7642 (Full_N, Full_Parent, Full_Der, Derive_Subps);
7643 else
7644 Build_Derived_Record_Type
7645 (Full_N, Full_Parent, Full_Der, Derive_Subps => False);
7646 end if;
7648 else
7649 Build_Derived_Type
7650 (Full_N, Full_Parent, Full_Der,
7651 Is_Completion => False, Derive_Subps => False);
7652 end if;
7654 -- The full declaration has been introduced into the tree and
7655 -- processed in the step above. It should not be analyzed again
7656 -- (when encountered later in the current list of declarations)
7657 -- to prevent spurious name conflicts. The full entity remains
7658 -- invisible.
7660 Set_Analyzed (Full_N);
7662 else
7663 Full_Der :=
7664 Make_Defining_Identifier (Sloc (Derived_Type),
7665 Chars => Chars (Derived_Type));
7666 Set_Is_Itype (Full_Der);
7667 Set_Associated_Node_For_Itype (Full_Der, N);
7668 Set_Parent (Full_Der, N);
7669 Build_Derived_Type
7670 (N, Full_Parent, Full_Der,
7671 Is_Completion => False, Derive_Subps => False);
7672 end if;
7674 Set_Has_Private_Declaration (Full_Der);
7675 Set_Has_Private_Declaration (Derived_Type);
7677 Set_Scope (Full_Der, Scope (Derived_Type));
7678 Set_Is_First_Subtype (Full_Der, Is_First_Subtype (Derived_Type));
7679 Set_Has_Size_Clause (Full_Der, False);
7680 Set_Has_Alignment_Clause (Full_Der, False);
7681 Set_Has_Delayed_Freeze (Full_Der);
7682 Set_Is_Frozen (Full_Der, False);
7683 Set_Freeze_Node (Full_Der, Empty);
7684 Set_Depends_On_Private (Full_Der, Has_Private_Component (Full_Der));
7685 Set_Is_Public (Full_Der, Is_Public (Derived_Type));
7687 -- The convention on the base type may be set in the private part
7688 -- and not propagated to the subtype until later, so we obtain the
7689 -- convention from the base type of the parent.
7691 Set_Convention (Full_Der, Convention (Base_Type (Full_Parent)));
7692 end Copy_And_Build;
7694 -- Start of processing for Build_Derived_Private_Type
7696 begin
7697 if Is_Tagged_Type (Parent_Type) then
7698 Full_P := Full_View (Parent_Type);
7700 -- A type extension of a type with unknown discriminants is an
7701 -- indefinite type that the back-end cannot handle directly.
7702 -- We treat it as a private type, and build a completion that is
7703 -- derived from the full view of the parent, and hopefully has
7704 -- known discriminants.
7706 -- If the full view of the parent type has an underlying record view,
7707 -- use it to generate the underlying record view of this derived type
7708 -- (required for chains of derivations with unknown discriminants).
7710 -- Minor optimization: we avoid the generation of useless underlying
7711 -- record view entities if the private type declaration has unknown
7712 -- discriminants but its corresponding full view has no
7713 -- discriminants.
7715 if Has_Unknown_Discriminants (Parent_Type)
7716 and then Present (Full_P)
7717 and then (Has_Discriminants (Full_P)
7718 or else Present (Underlying_Record_View (Full_P)))
7719 and then not In_Open_Scopes (Par_Scope)
7720 and then Expander_Active
7721 then
7722 declare
7723 Full_Der : constant Entity_Id := Make_Temporary (Loc, 'T');
7724 New_Ext : constant Node_Id :=
7725 Copy_Separate_Tree
7726 (Record_Extension_Part (Type_Definition (N)));
7727 Decl : Node_Id;
7729 begin
7730 Build_Derived_Record_Type
7731 (N, Parent_Type, Derived_Type, Derive_Subps);
7733 -- Build anonymous completion, as a derivation from the full
7734 -- view of the parent. This is not a completion in the usual
7735 -- sense, because the current type is not private.
7737 Decl :=
7738 Make_Full_Type_Declaration (Loc,
7739 Defining_Identifier => Full_Der,
7740 Type_Definition =>
7741 Make_Derived_Type_Definition (Loc,
7742 Subtype_Indication =>
7743 New_Copy_Tree
7744 (Subtype_Indication (Type_Definition (N))),
7745 Record_Extension_Part => New_Ext));
7747 -- If the parent type has an underlying record view, use it
7748 -- here to build the new underlying record view.
7750 if Present (Underlying_Record_View (Full_P)) then
7751 pragma Assert
7752 (Nkind (Subtype_Indication (Type_Definition (Decl)))
7753 = N_Identifier);
7754 Set_Entity (Subtype_Indication (Type_Definition (Decl)),
7755 Underlying_Record_View (Full_P));
7756 end if;
7758 Install_Private_Declarations (Par_Scope);
7759 Install_Visible_Declarations (Par_Scope);
7760 Insert_Before (N, Decl);
7762 -- Mark entity as an underlying record view before analysis,
7763 -- to avoid generating the list of its primitive operations
7764 -- (which is not really required for this entity) and thus
7765 -- prevent spurious errors associated with missing overriding
7766 -- of abstract primitives (overridden only for Derived_Type).
7768 Set_Ekind (Full_Der, E_Record_Type);
7769 Set_Is_Underlying_Record_View (Full_Der);
7770 Set_Default_SSO (Full_Der);
7771 Set_No_Reordering (Full_Der, No_Component_Reordering);
7773 Analyze (Decl);
7775 pragma Assert (Has_Discriminants (Full_Der)
7776 and then not Has_Unknown_Discriminants (Full_Der));
7778 Uninstall_Declarations (Par_Scope);
7780 -- Freeze the underlying record view, to prevent generation of
7781 -- useless dispatching information, which is simply shared with
7782 -- the real derived type.
7784 Set_Is_Frozen (Full_Der);
7786 -- If the derived type has access discriminants, create
7787 -- references to their anonymous types now, to prevent
7788 -- back-end problems when their first use is in generated
7789 -- bodies of primitives.
7791 declare
7792 E : Entity_Id;
7794 begin
7795 E := First_Entity (Full_Der);
7797 while Present (E) loop
7798 if Ekind (E) = E_Discriminant
7799 and then Ekind (Etype (E)) = E_Anonymous_Access_Type
7800 then
7801 Build_Itype_Reference (Etype (E), Decl);
7802 end if;
7804 Next_Entity (E);
7805 end loop;
7806 end;
7808 -- Set up links between real entity and underlying record view
7810 Set_Underlying_Record_View (Derived_Type, Base_Type (Full_Der));
7811 Set_Underlying_Record_View (Base_Type (Full_Der), Derived_Type);
7812 end;
7814 -- If discriminants are known, build derived record
7816 else
7817 Build_Derived_Record_Type
7818 (N, Parent_Type, Derived_Type, Derive_Subps);
7819 end if;
7821 return;
7823 elsif Has_Discriminants (Parent_Type) then
7825 -- Build partial view of derived type from partial view of parent.
7826 -- This must be done before building the full derivation because the
7827 -- second derivation will modify the discriminants of the first and
7828 -- the discriminants are chained with the rest of the components in
7829 -- the full derivation.
7831 Build_Derived_Record_Type
7832 (N, Parent_Type, Derived_Type, Derive_Subps);
7834 -- Build the full derivation if this is not the anonymous derived
7835 -- base type created by Build_Derived_Record_Type in the constrained
7836 -- case (see point 5. of its head comment) since we build it for the
7837 -- derived subtype. And skip it for protected types altogether, as
7838 -- gigi does not use these types directly.
7840 if Present (Full_View (Parent_Type))
7841 and then not Is_Itype (Derived_Type)
7842 and then not (Ekind (Full_View (Parent_Type)) in Protected_Kind)
7843 then
7844 declare
7845 Der_Base : constant Entity_Id := Base_Type (Derived_Type);
7846 Discr : Entity_Id;
7847 Last_Discr : Entity_Id;
7849 begin
7850 -- If this is not a completion, construct the implicit full
7851 -- view by deriving from the full view of the parent type.
7852 -- But if this is a completion, the derived private type
7853 -- being built is a full view and the full derivation can
7854 -- only be its underlying full view.
7856 Build_Full_Derivation;
7858 if not Is_Completion then
7859 Set_Full_View (Derived_Type, Full_Der);
7860 else
7861 Set_Underlying_Full_View (Derived_Type, Full_Der);
7862 Set_Is_Underlying_Full_View (Full_Der);
7863 end if;
7865 if not Is_Base_Type (Derived_Type) then
7866 Set_Full_View (Der_Base, Base_Type (Full_Der));
7867 end if;
7869 -- Copy the discriminant list from full view to the partial
7870 -- view (base type and its subtype). Gigi requires that the
7871 -- partial and full views have the same discriminants.
7873 -- Note that since the partial view points to discriminants
7874 -- in the full view, their scope will be that of the full
7875 -- view. This might cause some front end problems and need
7876 -- adjustment???
7878 Discr := First_Discriminant (Base_Type (Full_Der));
7879 Set_First_Entity (Der_Base, Discr);
7881 loop
7882 Last_Discr := Discr;
7883 Next_Discriminant (Discr);
7884 exit when No (Discr);
7885 end loop;
7887 Set_Last_Entity (Der_Base, Last_Discr);
7888 Set_First_Entity (Derived_Type, First_Entity (Der_Base));
7889 Set_Last_Entity (Derived_Type, Last_Entity (Der_Base));
7890 end;
7891 end if;
7893 elsif Present (Full_View (Parent_Type))
7894 and then Has_Discriminants (Full_View (Parent_Type))
7895 then
7896 if Has_Unknown_Discriminants (Parent_Type)
7897 and then Nkind (Subtype_Indication (Type_Definition (N))) =
7898 N_Subtype_Indication
7899 then
7900 Error_Msg_N
7901 ("cannot constrain type with unknown discriminants",
7902 Subtype_Indication (Type_Definition (N)));
7903 return;
7904 end if;
7906 -- If this is not a completion, construct the implicit full view by
7907 -- deriving from the full view of the parent type. But if this is a
7908 -- completion, the derived private type being built is a full view
7909 -- and the full derivation can only be its underlying full view.
7911 Build_Full_Derivation;
7913 if not Is_Completion then
7914 Set_Full_View (Derived_Type, Full_Der);
7915 else
7916 Set_Underlying_Full_View (Derived_Type, Full_Der);
7917 Set_Is_Underlying_Full_View (Full_Der);
7918 end if;
7920 -- In any case, the primitive operations are inherited from the
7921 -- parent type, not from the internal full view.
7923 Set_Etype (Base_Type (Derived_Type), Base_Type (Parent_Type));
7925 if Derive_Subps then
7926 Derive_Subprograms (Parent_Type, Derived_Type);
7927 end if;
7929 Set_Stored_Constraint (Derived_Type, No_Elist);
7930 Set_Is_Constrained
7931 (Derived_Type, Is_Constrained (Full_View (Parent_Type)));
7933 else
7934 -- Untagged type, No discriminants on either view
7936 if Nkind (Subtype_Indication (Type_Definition (N))) =
7937 N_Subtype_Indication
7938 then
7939 Error_Msg_N
7940 ("illegal constraint on type without discriminants", N);
7941 end if;
7943 if Present (Discriminant_Specifications (N))
7944 and then Present (Full_View (Parent_Type))
7945 and then not Is_Tagged_Type (Full_View (Parent_Type))
7946 then
7947 Error_Msg_N ("cannot add discriminants to untagged type", N);
7948 end if;
7950 Set_Stored_Constraint (Derived_Type, No_Elist);
7951 Set_Is_Constrained (Derived_Type, Is_Constrained (Parent_Type));
7953 Set_Is_Controlled_Active
7954 (Derived_Type, Is_Controlled_Active (Parent_Type));
7956 Set_Disable_Controlled
7957 (Derived_Type, Disable_Controlled (Parent_Type));
7959 Set_Has_Controlled_Component
7960 (Derived_Type, Has_Controlled_Component (Parent_Type));
7962 -- Direct controlled types do not inherit Finalize_Storage_Only flag
7964 if not Is_Controlled (Parent_Type) then
7965 Set_Finalize_Storage_Only
7966 (Base_Type (Derived_Type), Finalize_Storage_Only (Parent_Type));
7967 end if;
7969 -- If this is not a completion, construct the implicit full view by
7970 -- deriving from the full view of the parent type.
7972 -- ??? If the parent is untagged private and its completion is
7973 -- tagged, this mechanism will not work because we cannot derive from
7974 -- the tagged full view unless we have an extension.
7976 if Present (Full_View (Parent_Type))
7977 and then not Is_Tagged_Type (Full_View (Parent_Type))
7978 and then not Is_Completion
7979 then
7980 Build_Full_Derivation;
7981 Set_Full_View (Derived_Type, Full_Der);
7982 end if;
7983 end if;
7985 Set_Has_Unknown_Discriminants (Derived_Type,
7986 Has_Unknown_Discriminants (Parent_Type));
7988 if Is_Private_Type (Derived_Type) then
7989 Set_Private_Dependents (Derived_Type, New_Elmt_List);
7990 end if;
7992 -- If the parent base type is in scope, add the derived type to its
7993 -- list of private dependents, because its full view may become
7994 -- visible subsequently (in a nested private part, a body, or in a
7995 -- further child unit).
7997 if Is_Private_Type (Par_Base) and then In_Open_Scopes (Par_Scope) then
7998 Append_Elmt (Derived_Type, Private_Dependents (Parent_Type));
8000 -- Check for unusual case where a type completed by a private
8001 -- derivation occurs within a package nested in a child unit, and
8002 -- the parent is declared in an ancestor.
8004 if Is_Child_Unit (Scope (Current_Scope))
8005 and then Is_Completion
8006 and then In_Private_Part (Current_Scope)
8007 and then Scope (Parent_Type) /= Current_Scope
8009 -- Note that if the parent has a completion in the private part,
8010 -- (which is itself a derivation from some other private type)
8011 -- it is that completion that is visible, there is no full view
8012 -- available, and no special processing is needed.
8014 and then Present (Full_View (Parent_Type))
8015 then
8016 -- In this case, the full view of the parent type will become
8017 -- visible in the body of the enclosing child, and only then will
8018 -- the current type be possibly non-private. Build an underlying
8019 -- full view that will be installed when the enclosing child body
8020 -- is compiled.
8022 if Present (Underlying_Full_View (Derived_Type)) then
8023 Full_Der := Underlying_Full_View (Derived_Type);
8024 else
8025 Build_Full_Derivation;
8026 Set_Underlying_Full_View (Derived_Type, Full_Der);
8027 Set_Is_Underlying_Full_View (Full_Der);
8028 end if;
8030 -- The full view will be used to swap entities on entry/exit to
8031 -- the body, and must appear in the entity list for the package.
8033 Append_Entity (Full_Der, Scope (Derived_Type));
8034 end if;
8035 end if;
8036 end Build_Derived_Private_Type;
8038 -------------------------------
8039 -- Build_Derived_Record_Type --
8040 -------------------------------
8042 -- 1. INTRODUCTION
8044 -- Ideally we would like to use the same model of type derivation for
8045 -- tagged and untagged record types. Unfortunately this is not quite
8046 -- possible because the semantics of representation clauses is different
8047 -- for tagged and untagged records under inheritance. Consider the
8048 -- following:
8050 -- type R (...) is [tagged] record ... end record;
8051 -- type T (...) is new R (...) [with ...];
8053 -- The representation clauses for T can specify a completely different
8054 -- record layout from R's. Hence the same component can be placed in two
8055 -- very different positions in objects of type T and R. If R and T are
8056 -- tagged types, representation clauses for T can only specify the layout
8057 -- of non inherited components, thus components that are common in R and T
8058 -- have the same position in objects of type R and T.
8060 -- This has two implications. The first is that the entire tree for R's
8061 -- declaration needs to be copied for T in the untagged case, so that T
8062 -- can be viewed as a record type of its own with its own representation
8063 -- clauses. The second implication is the way we handle discriminants.
8064 -- Specifically, in the untagged case we need a way to communicate to Gigi
8065 -- what are the real discriminants in the record, while for the semantics
8066 -- we need to consider those introduced by the user to rename the
8067 -- discriminants in the parent type. This is handled by introducing the
8068 -- notion of stored discriminants. See below for more.
8070 -- Fortunately the way regular components are inherited can be handled in
8071 -- the same way in tagged and untagged types.
8073 -- To complicate things a bit more the private view of a private extension
8074 -- cannot be handled in the same way as the full view (for one thing the
8075 -- semantic rules are somewhat different). We will explain what differs
8076 -- below.
8078 -- 2. DISCRIMINANTS UNDER INHERITANCE
8080 -- The semantic rules governing the discriminants of derived types are
8081 -- quite subtle.
8083 -- type Derived_Type_Name [KNOWN_DISCRIMINANT_PART] is new
8084 -- [abstract] Parent_Type_Name [CONSTRAINT] [RECORD_EXTENSION_PART]
8086 -- If parent type has discriminants, then the discriminants that are
8087 -- declared in the derived type are [3.4 (11)]:
8089 -- o The discriminants specified by a new KNOWN_DISCRIMINANT_PART, if
8090 -- there is one;
8092 -- o Otherwise, each discriminant of the parent type (implicitly declared
8093 -- in the same order with the same specifications). In this case, the
8094 -- discriminants are said to be "inherited", or if unknown in the parent
8095 -- are also unknown in the derived type.
8097 -- Furthermore if a KNOWN_DISCRIMINANT_PART is provided, then [3.7(13-18)]:
8099 -- o The parent subtype must be constrained;
8101 -- o If the parent type is not a tagged type, then each discriminant of
8102 -- the derived type must be used in the constraint defining a parent
8103 -- subtype. [Implementation note: This ensures that the new discriminant
8104 -- can share storage with an existing discriminant.]
8106 -- For the derived type each discriminant of the parent type is either
8107 -- inherited, constrained to equal some new discriminant of the derived
8108 -- type, or constrained to the value of an expression.
8110 -- When inherited or constrained to equal some new discriminant, the
8111 -- parent discriminant and the discriminant of the derived type are said
8112 -- to "correspond".
8114 -- If a discriminant of the parent type is constrained to a specific value
8115 -- in the derived type definition, then the discriminant is said to be
8116 -- "specified" by that derived type definition.
8118 -- 3. DISCRIMINANTS IN DERIVED UNTAGGED RECORD TYPES
8120 -- We have spoken about stored discriminants in point 1 (introduction)
8121 -- above. There are two sorts of stored discriminants: implicit and
8122 -- explicit. As long as the derived type inherits the same discriminants as
8123 -- the root record type, stored discriminants are the same as regular
8124 -- discriminants, and are said to be implicit. However, if any discriminant
8125 -- in the root type was renamed in the derived type, then the derived
8126 -- type will contain explicit stored discriminants. Explicit stored
8127 -- discriminants are discriminants in addition to the semantically visible
8128 -- discriminants defined for the derived type. Stored discriminants are
8129 -- used by Gigi to figure out what are the physical discriminants in
8130 -- objects of the derived type (see precise definition in einfo.ads).
8131 -- As an example, consider the following:
8133 -- type R (D1, D2, D3 : Int) is record ... end record;
8134 -- type T1 is new R;
8135 -- type T2 (X1, X2: Int) is new T1 (X2, 88, X1);
8136 -- type T3 is new T2;
8137 -- type T4 (Y : Int) is new T3 (Y, 99);
8139 -- The following table summarizes the discriminants and stored
8140 -- discriminants in R and T1 through T4:
8142 -- Type Discrim Stored Discrim Comment
8143 -- R (D1, D2, D3) (D1, D2, D3) Girder discrims implicit in R
8144 -- T1 (D1, D2, D3) (D1, D2, D3) Girder discrims implicit in T1
8145 -- T2 (X1, X2) (D1, D2, D3) Girder discrims EXPLICIT in T2
8146 -- T3 (X1, X2) (D1, D2, D3) Girder discrims EXPLICIT in T3
8147 -- T4 (Y) (D1, D2, D3) Girder discrims EXPLICIT in T4
8149 -- Field Corresponding_Discriminant (abbreviated CD below) allows us to
8150 -- find the corresponding discriminant in the parent type, while
8151 -- Original_Record_Component (abbreviated ORC below) the actual physical
8152 -- component that is renamed. Finally the field Is_Completely_Hidden
8153 -- (abbreviated ICH below) is set for all explicit stored discriminants
8154 -- (see einfo.ads for more info). For the above example this gives:
8156 -- Discrim CD ORC ICH
8157 -- ^^^^^^^ ^^ ^^^ ^^^
8158 -- D1 in R empty itself no
8159 -- D2 in R empty itself no
8160 -- D3 in R empty itself no
8162 -- D1 in T1 D1 in R itself no
8163 -- D2 in T1 D2 in R itself no
8164 -- D3 in T1 D3 in R itself no
8166 -- X1 in T2 D3 in T1 D3 in T2 no
8167 -- X2 in T2 D1 in T1 D1 in T2 no
8168 -- D1 in T2 empty itself yes
8169 -- D2 in T2 empty itself yes
8170 -- D3 in T2 empty itself yes
8172 -- X1 in T3 X1 in T2 D3 in T3 no
8173 -- X2 in T3 X2 in T2 D1 in T3 no
8174 -- D1 in T3 empty itself yes
8175 -- D2 in T3 empty itself yes
8176 -- D3 in T3 empty itself yes
8178 -- Y in T4 X1 in T3 D3 in T4 no
8179 -- D1 in T4 empty itself yes
8180 -- D2 in T4 empty itself yes
8181 -- D3 in T4 empty itself yes
8183 -- 4. DISCRIMINANTS IN DERIVED TAGGED RECORD TYPES
8185 -- Type derivation for tagged types is fairly straightforward. If no
8186 -- discriminants are specified by the derived type, these are inherited
8187 -- from the parent. No explicit stored discriminants are ever necessary.
8188 -- The only manipulation that is done to the tree is that of adding a
8189 -- _parent field with parent type and constrained to the same constraint
8190 -- specified for the parent in the derived type definition. For instance:
8192 -- type R (D1, D2, D3 : Int) is tagged record ... end record;
8193 -- type T1 is new R with null record;
8194 -- type T2 (X1, X2: Int) is new T1 (X2, 88, X1) with null record;
8196 -- are changed into:
8198 -- type T1 (D1, D2, D3 : Int) is new R (D1, D2, D3) with record
8199 -- _parent : R (D1, D2, D3);
8200 -- end record;
8202 -- type T2 (X1, X2: Int) is new T1 (X2, 88, X1) with record
8203 -- _parent : T1 (X2, 88, X1);
8204 -- end record;
8206 -- The discriminants actually present in R, T1 and T2 as well as their CD,
8207 -- ORC and ICH fields are:
8209 -- Discrim CD ORC ICH
8210 -- ^^^^^^^ ^^ ^^^ ^^^
8211 -- D1 in R empty itself no
8212 -- D2 in R empty itself no
8213 -- D3 in R empty itself no
8215 -- D1 in T1 D1 in R D1 in R no
8216 -- D2 in T1 D2 in R D2 in R no
8217 -- D3 in T1 D3 in R D3 in R no
8219 -- X1 in T2 D3 in T1 D3 in R no
8220 -- X2 in T2 D1 in T1 D1 in R no
8222 -- 5. FIRST TRANSFORMATION FOR DERIVED RECORDS
8224 -- Regardless of whether we dealing with a tagged or untagged type
8225 -- we will transform all derived type declarations of the form
8227 -- type T is new R (...) [with ...];
8228 -- or
8229 -- subtype S is R (...);
8230 -- type T is new S [with ...];
8231 -- into
8232 -- type BT is new R [with ...];
8233 -- subtype T is BT (...);
8235 -- That is, the base derived type is constrained only if it has no
8236 -- discriminants. The reason for doing this is that GNAT's semantic model
8237 -- assumes that a base type with discriminants is unconstrained.
8239 -- Note that, strictly speaking, the above transformation is not always
8240 -- correct. Consider for instance the following excerpt from ACVC b34011a:
8242 -- procedure B34011A is
8243 -- type REC (D : integer := 0) is record
8244 -- I : Integer;
8245 -- end record;
8247 -- package P is
8248 -- type T6 is new Rec;
8249 -- function F return T6;
8250 -- end P;
8252 -- use P;
8253 -- package Q6 is
8254 -- type U is new T6 (Q6.F.I); -- ERROR: Q6.F.
8255 -- end Q6;
8257 -- The definition of Q6.U is illegal. However transforming Q6.U into
8259 -- type BaseU is new T6;
8260 -- subtype U is BaseU (Q6.F.I)
8262 -- turns U into a legal subtype, which is incorrect. To avoid this problem
8263 -- we always analyze the constraint (in this case (Q6.F.I)) before applying
8264 -- the transformation described above.
8266 -- There is another instance where the above transformation is incorrect.
8267 -- Consider:
8269 -- package Pack is
8270 -- type Base (D : Integer) is tagged null record;
8271 -- procedure P (X : Base);
8273 -- type Der is new Base (2) with null record;
8274 -- procedure P (X : Der);
8275 -- end Pack;
8277 -- Then the above transformation turns this into
8279 -- type Der_Base is new Base with null record;
8280 -- -- procedure P (X : Base) is implicitly inherited here
8281 -- -- as procedure P (X : Der_Base).
8283 -- subtype Der is Der_Base (2);
8284 -- procedure P (X : Der);
8285 -- -- The overriding of P (X : Der_Base) is illegal since we
8286 -- -- have a parameter conformance problem.
8288 -- To get around this problem, after having semantically processed Der_Base
8289 -- and the rewritten subtype declaration for Der, we copy Der_Base field
8290 -- Discriminant_Constraint from Der so that when parameter conformance is
8291 -- checked when P is overridden, no semantic errors are flagged.
8293 -- 6. SECOND TRANSFORMATION FOR DERIVED RECORDS
8295 -- Regardless of whether we are dealing with a tagged or untagged type
8296 -- we will transform all derived type declarations of the form
8298 -- type R (D1, .., Dn : ...) is [tagged] record ...;
8299 -- type T is new R [with ...];
8300 -- into
8301 -- type T (D1, .., Dn : ...) is new R (D1, .., Dn) [with ...];
8303 -- The reason for such transformation is that it allows us to implement a
8304 -- very clean form of component inheritance as explained below.
8306 -- Note that this transformation is not achieved by direct tree rewriting
8307 -- and manipulation, but rather by redoing the semantic actions that the
8308 -- above transformation will entail. This is done directly in routine
8309 -- Inherit_Components.
8311 -- 7. TYPE DERIVATION AND COMPONENT INHERITANCE
8313 -- In both tagged and untagged derived types, regular non discriminant
8314 -- components are inherited in the derived type from the parent type. In
8315 -- the absence of discriminants component, inheritance is straightforward
8316 -- as components can simply be copied from the parent.
8318 -- If the parent has discriminants, inheriting components constrained with
8319 -- these discriminants requires caution. Consider the following example:
8321 -- type R (D1, D2 : Positive) is [tagged] record
8322 -- S : String (D1 .. D2);
8323 -- end record;
8325 -- type T1 is new R [with null record];
8326 -- type T2 (X : positive) is new R (1, X) [with null record];
8328 -- As explained in 6. above, T1 is rewritten as
8329 -- type T1 (D1, D2 : Positive) is new R (D1, D2) [with null record];
8330 -- which makes the treatment for T1 and T2 identical.
8332 -- What we want when inheriting S, is that references to D1 and D2 in R are
8333 -- replaced with references to their correct constraints, i.e. D1 and D2 in
8334 -- T1 and 1 and X in T2. So all R's discriminant references are replaced
8335 -- with either discriminant references in the derived type or expressions.
8336 -- This replacement is achieved as follows: before inheriting R's
8337 -- components, a subtype R (D1, D2) for T1 (resp. R (1, X) for T2) is
8338 -- created in the scope of T1 (resp. scope of T2) so that discriminants D1
8339 -- and D2 of T1 are visible (resp. discriminant X of T2 is visible).
8340 -- For T2, for instance, this has the effect of replacing String (D1 .. D2)
8341 -- by String (1 .. X).
8343 -- 8. TYPE DERIVATION IN PRIVATE TYPE EXTENSIONS
8345 -- We explain here the rules governing private type extensions relevant to
8346 -- type derivation. These rules are explained on the following example:
8348 -- type D [(...)] is new A [(...)] with private; <-- partial view
8349 -- type D [(...)] is new P [(...)] with null record; <-- full view
8351 -- Type A is called the ancestor subtype of the private extension.
8352 -- Type P is the parent type of the full view of the private extension. It
8353 -- must be A or a type derived from A.
8355 -- The rules concerning the discriminants of private type extensions are
8356 -- [7.3(10-13)]:
8358 -- o If a private extension inherits known discriminants from the ancestor
8359 -- subtype, then the full view must also inherit its discriminants from
8360 -- the ancestor subtype and the parent subtype of the full view must be
8361 -- constrained if and only if the ancestor subtype is constrained.
8363 -- o If a partial view has unknown discriminants, then the full view may
8364 -- define a definite or an indefinite subtype, with or without
8365 -- discriminants.
8367 -- o If a partial view has neither known nor unknown discriminants, then
8368 -- the full view must define a definite subtype.
8370 -- o If the ancestor subtype of a private extension has constrained
8371 -- discriminants, then the parent subtype of the full view must impose a
8372 -- statically matching constraint on those discriminants.
8374 -- This means that only the following forms of private extensions are
8375 -- allowed:
8377 -- type D is new A with private; <-- partial view
8378 -- type D is new P with null record; <-- full view
8380 -- If A has no discriminants than P has no discriminants, otherwise P must
8381 -- inherit A's discriminants.
8383 -- type D is new A (...) with private; <-- partial view
8384 -- type D is new P (:::) with null record; <-- full view
8386 -- P must inherit A's discriminants and (...) and (:::) must statically
8387 -- match.
8389 -- subtype A is R (...);
8390 -- type D is new A with private; <-- partial view
8391 -- type D is new P with null record; <-- full view
8393 -- P must have inherited R's discriminants and must be derived from A or
8394 -- any of its subtypes.
8396 -- type D (..) is new A with private; <-- partial view
8397 -- type D (..) is new P [(:::)] with null record; <-- full view
8399 -- No specific constraints on P's discriminants or constraint (:::).
8400 -- Note that A can be unconstrained, but the parent subtype P must either
8401 -- be constrained or (:::) must be present.
8403 -- type D (..) is new A [(...)] with private; <-- partial view
8404 -- type D (..) is new P [(:::)] with null record; <-- full view
8406 -- P's constraints on A's discriminants must statically match those
8407 -- imposed by (...).
8409 -- 9. IMPLEMENTATION OF TYPE DERIVATION FOR PRIVATE EXTENSIONS
8411 -- The full view of a private extension is handled exactly as described
8412 -- above. The model chose for the private view of a private extension is
8413 -- the same for what concerns discriminants (i.e. they receive the same
8414 -- treatment as in the tagged case). However, the private view of the
8415 -- private extension always inherits the components of the parent base,
8416 -- without replacing any discriminant reference. Strictly speaking this is
8417 -- incorrect. However, Gigi never uses this view to generate code so this
8418 -- is a purely semantic issue. In theory, a set of transformations similar
8419 -- to those given in 5. and 6. above could be applied to private views of
8420 -- private extensions to have the same model of component inheritance as
8421 -- for non private extensions. However, this is not done because it would
8422 -- further complicate private type processing. Semantically speaking, this
8423 -- leaves us in an uncomfortable situation. As an example consider:
8425 -- package Pack is
8426 -- type R (D : integer) is tagged record
8427 -- S : String (1 .. D);
8428 -- end record;
8429 -- procedure P (X : R);
8430 -- type T is new R (1) with private;
8431 -- private
8432 -- type T is new R (1) with null record;
8433 -- end;
8435 -- This is transformed into:
8437 -- package Pack is
8438 -- type R (D : integer) is tagged record
8439 -- S : String (1 .. D);
8440 -- end record;
8441 -- procedure P (X : R);
8442 -- type T is new R (1) with private;
8443 -- private
8444 -- type BaseT is new R with null record;
8445 -- subtype T is BaseT (1);
8446 -- end;
8448 -- (strictly speaking the above is incorrect Ada)
8450 -- From the semantic standpoint the private view of private extension T
8451 -- should be flagged as constrained since one can clearly have
8453 -- Obj : T;
8455 -- in a unit withing Pack. However, when deriving subprograms for the
8456 -- private view of private extension T, T must be seen as unconstrained
8457 -- since T has discriminants (this is a constraint of the current
8458 -- subprogram derivation model). Thus, when processing the private view of
8459 -- a private extension such as T, we first mark T as unconstrained, we
8460 -- process it, we perform program derivation and just before returning from
8461 -- Build_Derived_Record_Type we mark T as constrained.
8463 -- ??? Are there are other uncomfortable cases that we will have to
8464 -- deal with.
8466 -- 10. RECORD_TYPE_WITH_PRIVATE complications
8468 -- Types that are derived from a visible record type and have a private
8469 -- extension present other peculiarities. They behave mostly like private
8470 -- types, but if they have primitive operations defined, these will not
8471 -- have the proper signatures for further inheritance, because other
8472 -- primitive operations will use the implicit base that we define for
8473 -- private derivations below. This affect subprogram inheritance (see
8474 -- Derive_Subprograms for details). We also derive the implicit base from
8475 -- the base type of the full view, so that the implicit base is a record
8476 -- type and not another private type, This avoids infinite loops.
8478 procedure Build_Derived_Record_Type
8479 (N : Node_Id;
8480 Parent_Type : Entity_Id;
8481 Derived_Type : Entity_Id;
8482 Derive_Subps : Boolean := True)
8484 Discriminant_Specs : constant Boolean :=
8485 Present (Discriminant_Specifications (N));
8486 Is_Tagged : constant Boolean := Is_Tagged_Type (Parent_Type);
8487 Loc : constant Source_Ptr := Sloc (N);
8488 Private_Extension : constant Boolean :=
8489 Nkind (N) = N_Private_Extension_Declaration;
8490 Assoc_List : Elist_Id;
8491 Constraint_Present : Boolean;
8492 Constrs : Elist_Id;
8493 Discrim : Entity_Id;
8494 Indic : Node_Id;
8495 Inherit_Discrims : Boolean := False;
8496 Last_Discrim : Entity_Id;
8497 New_Base : Entity_Id;
8498 New_Decl : Node_Id;
8499 New_Discrs : Elist_Id;
8500 New_Indic : Node_Id;
8501 Parent_Base : Entity_Id;
8502 Save_Etype : Entity_Id;
8503 Save_Discr_Constr : Elist_Id;
8504 Save_Next_Entity : Entity_Id;
8505 Type_Def : Node_Id;
8507 Discs : Elist_Id := New_Elmt_List;
8508 -- An empty Discs list means that there were no constraints in the
8509 -- subtype indication or that there was an error processing it.
8511 begin
8512 if Ekind (Parent_Type) = E_Record_Type_With_Private
8513 and then Present (Full_View (Parent_Type))
8514 and then Has_Discriminants (Parent_Type)
8515 then
8516 Parent_Base := Base_Type (Full_View (Parent_Type));
8517 else
8518 Parent_Base := Base_Type (Parent_Type);
8519 end if;
8521 -- AI05-0115: if this is a derivation from a private type in some
8522 -- other scope that may lead to invisible components for the derived
8523 -- type, mark it accordingly.
8525 if Is_Private_Type (Parent_Type) then
8526 if Scope (Parent_Base) = Scope (Derived_Type) then
8527 null;
8529 elsif In_Open_Scopes (Scope (Parent_Base))
8530 and then In_Private_Part (Scope (Parent_Base))
8531 then
8532 null;
8534 else
8535 Set_Has_Private_Ancestor (Derived_Type);
8536 end if;
8538 else
8539 Set_Has_Private_Ancestor
8540 (Derived_Type, Has_Private_Ancestor (Parent_Type));
8541 end if;
8543 -- Before we start the previously documented transformations, here is
8544 -- little fix for size and alignment of tagged types. Normally when we
8545 -- derive type D from type P, we copy the size and alignment of P as the
8546 -- default for D, and in the absence of explicit representation clauses
8547 -- for D, the size and alignment are indeed the same as the parent.
8549 -- But this is wrong for tagged types, since fields may be added, and
8550 -- the default size may need to be larger, and the default alignment may
8551 -- need to be larger.
8553 -- We therefore reset the size and alignment fields in the tagged case.
8554 -- Note that the size and alignment will in any case be at least as
8555 -- large as the parent type (since the derived type has a copy of the
8556 -- parent type in the _parent field)
8558 -- The type is also marked as being tagged here, which is needed when
8559 -- processing components with a self-referential anonymous access type
8560 -- in the call to Check_Anonymous_Access_Components below. Note that
8561 -- this flag is also set later on for completeness.
8563 if Is_Tagged then
8564 Set_Is_Tagged_Type (Derived_Type);
8565 Init_Size_Align (Derived_Type);
8566 end if;
8568 -- STEP 0a: figure out what kind of derived type declaration we have
8570 if Private_Extension then
8571 Type_Def := N;
8572 Set_Ekind (Derived_Type, E_Record_Type_With_Private);
8573 Set_Default_SSO (Derived_Type);
8574 Set_No_Reordering (Derived_Type, No_Component_Reordering);
8576 else
8577 Type_Def := Type_Definition (N);
8579 -- Ekind (Parent_Base) is not necessarily E_Record_Type since
8580 -- Parent_Base can be a private type or private extension. However,
8581 -- for tagged types with an extension the newly added fields are
8582 -- visible and hence the Derived_Type is always an E_Record_Type.
8583 -- (except that the parent may have its own private fields).
8584 -- For untagged types we preserve the Ekind of the Parent_Base.
8586 if Present (Record_Extension_Part (Type_Def)) then
8587 Set_Ekind (Derived_Type, E_Record_Type);
8588 Set_Default_SSO (Derived_Type);
8589 Set_No_Reordering (Derived_Type, No_Component_Reordering);
8591 -- Create internal access types for components with anonymous
8592 -- access types.
8594 if Ada_Version >= Ada_2005 then
8595 Check_Anonymous_Access_Components
8596 (N, Derived_Type, Derived_Type,
8597 Component_List (Record_Extension_Part (Type_Def)));
8598 end if;
8600 else
8601 Set_Ekind (Derived_Type, Ekind (Parent_Base));
8602 end if;
8603 end if;
8605 -- Indic can either be an N_Identifier if the subtype indication
8606 -- contains no constraint or an N_Subtype_Indication if the subtype
8607 -- indication has a constraint.
8609 Indic := Subtype_Indication (Type_Def);
8610 Constraint_Present := (Nkind (Indic) = N_Subtype_Indication);
8612 -- Check that the type has visible discriminants. The type may be
8613 -- a private type with unknown discriminants whose full view has
8614 -- discriminants which are invisible.
8616 if Constraint_Present then
8617 if not Has_Discriminants (Parent_Base)
8618 or else
8619 (Has_Unknown_Discriminants (Parent_Base)
8620 and then Is_Private_Type (Parent_Base))
8621 then
8622 Error_Msg_N
8623 ("invalid constraint: type has no discriminant",
8624 Constraint (Indic));
8626 Constraint_Present := False;
8627 Rewrite (Indic, New_Copy_Tree (Subtype_Mark (Indic)));
8629 elsif Is_Constrained (Parent_Type) then
8630 Error_Msg_N
8631 ("invalid constraint: parent type is already constrained",
8632 Constraint (Indic));
8634 Constraint_Present := False;
8635 Rewrite (Indic, New_Copy_Tree (Subtype_Mark (Indic)));
8636 end if;
8637 end if;
8639 -- STEP 0b: If needed, apply transformation given in point 5. above
8641 if not Private_Extension
8642 and then Has_Discriminants (Parent_Type)
8643 and then not Discriminant_Specs
8644 and then (Is_Constrained (Parent_Type) or else Constraint_Present)
8645 then
8646 -- First, we must analyze the constraint (see comment in point 5.)
8647 -- The constraint may come from the subtype indication of the full
8648 -- declaration.
8650 if Constraint_Present then
8651 New_Discrs := Build_Discriminant_Constraints (Parent_Type, Indic);
8653 -- If there is no explicit constraint, there might be one that is
8654 -- inherited from a constrained parent type. In that case verify that
8655 -- it conforms to the constraint in the partial view. In perverse
8656 -- cases the parent subtypes of the partial and full view can have
8657 -- different constraints.
8659 elsif Present (Stored_Constraint (Parent_Type)) then
8660 New_Discrs := Stored_Constraint (Parent_Type);
8662 else
8663 New_Discrs := No_Elist;
8664 end if;
8666 if Has_Discriminants (Derived_Type)
8667 and then Has_Private_Declaration (Derived_Type)
8668 and then Present (Discriminant_Constraint (Derived_Type))
8669 and then Present (New_Discrs)
8670 then
8671 -- Verify that constraints of the full view statically match
8672 -- those given in the partial view.
8674 declare
8675 C1, C2 : Elmt_Id;
8677 begin
8678 C1 := First_Elmt (New_Discrs);
8679 C2 := First_Elmt (Discriminant_Constraint (Derived_Type));
8680 while Present (C1) and then Present (C2) loop
8681 if Fully_Conformant_Expressions (Node (C1), Node (C2))
8682 or else
8683 (Is_OK_Static_Expression (Node (C1))
8684 and then Is_OK_Static_Expression (Node (C2))
8685 and then
8686 Expr_Value (Node (C1)) = Expr_Value (Node (C2)))
8687 then
8688 null;
8690 else
8691 if Constraint_Present then
8692 Error_Msg_N
8693 ("constraint not conformant to previous declaration",
8694 Node (C1));
8695 else
8696 Error_Msg_N
8697 ("constraint of full view is incompatible "
8698 & "with partial view", N);
8699 end if;
8700 end if;
8702 Next_Elmt (C1);
8703 Next_Elmt (C2);
8704 end loop;
8705 end;
8706 end if;
8708 -- Insert and analyze the declaration for the unconstrained base type
8710 New_Base := Create_Itype (Ekind (Derived_Type), N, Derived_Type, 'B');
8712 New_Decl :=
8713 Make_Full_Type_Declaration (Loc,
8714 Defining_Identifier => New_Base,
8715 Type_Definition =>
8716 Make_Derived_Type_Definition (Loc,
8717 Abstract_Present => Abstract_Present (Type_Def),
8718 Limited_Present => Limited_Present (Type_Def),
8719 Subtype_Indication =>
8720 New_Occurrence_Of (Parent_Base, Loc),
8721 Record_Extension_Part =>
8722 Relocate_Node (Record_Extension_Part (Type_Def)),
8723 Interface_List => Interface_List (Type_Def)));
8725 Set_Parent (New_Decl, Parent (N));
8726 Mark_Rewrite_Insertion (New_Decl);
8727 Insert_Before (N, New_Decl);
8729 -- In the extension case, make sure ancestor is frozen appropriately
8730 -- (see also non-discriminated case below).
8732 if Present (Record_Extension_Part (Type_Def))
8733 or else Is_Interface (Parent_Base)
8734 then
8735 Freeze_Before (New_Decl, Parent_Type);
8736 end if;
8738 -- Note that this call passes False for the Derive_Subps parameter
8739 -- because subprogram derivation is deferred until after creating
8740 -- the subtype (see below).
8742 Build_Derived_Type
8743 (New_Decl, Parent_Base, New_Base,
8744 Is_Completion => False, Derive_Subps => False);
8746 -- ??? This needs re-examination to determine whether the
8747 -- above call can simply be replaced by a call to Analyze.
8749 Set_Analyzed (New_Decl);
8751 -- Insert and analyze the declaration for the constrained subtype
8753 if Constraint_Present then
8754 New_Indic :=
8755 Make_Subtype_Indication (Loc,
8756 Subtype_Mark => New_Occurrence_Of (New_Base, Loc),
8757 Constraint => Relocate_Node (Constraint (Indic)));
8759 else
8760 declare
8761 Constr_List : constant List_Id := New_List;
8762 C : Elmt_Id;
8763 Expr : Node_Id;
8765 begin
8766 C := First_Elmt (Discriminant_Constraint (Parent_Type));
8767 while Present (C) loop
8768 Expr := Node (C);
8770 -- It is safe here to call New_Copy_Tree since we called
8771 -- Force_Evaluation on each constraint previously
8772 -- in Build_Discriminant_Constraints.
8774 Append (New_Copy_Tree (Expr), To => Constr_List);
8776 Next_Elmt (C);
8777 end loop;
8779 New_Indic :=
8780 Make_Subtype_Indication (Loc,
8781 Subtype_Mark => New_Occurrence_Of (New_Base, Loc),
8782 Constraint =>
8783 Make_Index_Or_Discriminant_Constraint (Loc, Constr_List));
8784 end;
8785 end if;
8787 Rewrite (N,
8788 Make_Subtype_Declaration (Loc,
8789 Defining_Identifier => Derived_Type,
8790 Subtype_Indication => New_Indic));
8792 Analyze (N);
8794 -- Derivation of subprograms must be delayed until the full subtype
8795 -- has been established, to ensure proper overriding of subprograms
8796 -- inherited by full types. If the derivations occurred as part of
8797 -- the call to Build_Derived_Type above, then the check for type
8798 -- conformance would fail because earlier primitive subprograms
8799 -- could still refer to the full type prior the change to the new
8800 -- subtype and hence would not match the new base type created here.
8801 -- Subprograms are not derived, however, when Derive_Subps is False
8802 -- (since otherwise there could be redundant derivations).
8804 if Derive_Subps then
8805 Derive_Subprograms (Parent_Type, Derived_Type);
8806 end if;
8808 -- For tagged types the Discriminant_Constraint of the new base itype
8809 -- is inherited from the first subtype so that no subtype conformance
8810 -- problem arise when the first subtype overrides primitive
8811 -- operations inherited by the implicit base type.
8813 if Is_Tagged then
8814 Set_Discriminant_Constraint
8815 (New_Base, Discriminant_Constraint (Derived_Type));
8816 end if;
8818 return;
8819 end if;
8821 -- If we get here Derived_Type will have no discriminants or it will be
8822 -- a discriminated unconstrained base type.
8824 -- STEP 1a: perform preliminary actions/checks for derived tagged types
8826 if Is_Tagged then
8828 -- The parent type is frozen for non-private extensions (RM 13.14(7))
8829 -- The declaration of a specific descendant of an interface type
8830 -- freezes the interface type (RM 13.14).
8832 if not Private_Extension or else Is_Interface (Parent_Base) then
8833 Freeze_Before (N, Parent_Type);
8834 end if;
8836 -- In Ada 2005 (AI-344), the restriction that a derived tagged type
8837 -- cannot be declared at a deeper level than its parent type is
8838 -- removed. The check on derivation within a generic body is also
8839 -- relaxed, but there's a restriction that a derived tagged type
8840 -- cannot be declared in a generic body if it's derived directly
8841 -- or indirectly from a formal type of that generic.
8843 if Ada_Version >= Ada_2005 then
8844 if Present (Enclosing_Generic_Body (Derived_Type)) then
8845 declare
8846 Ancestor_Type : Entity_Id;
8848 begin
8849 -- Check to see if any ancestor of the derived type is a
8850 -- formal type.
8852 Ancestor_Type := Parent_Type;
8853 while not Is_Generic_Type (Ancestor_Type)
8854 and then Etype (Ancestor_Type) /= Ancestor_Type
8855 loop
8856 Ancestor_Type := Etype (Ancestor_Type);
8857 end loop;
8859 -- If the derived type does have a formal type as an
8860 -- ancestor, then it's an error if the derived type is
8861 -- declared within the body of the generic unit that
8862 -- declares the formal type in its generic formal part. It's
8863 -- sufficient to check whether the ancestor type is declared
8864 -- inside the same generic body as the derived type (such as
8865 -- within a nested generic spec), in which case the
8866 -- derivation is legal. If the formal type is declared
8867 -- outside of that generic body, then it's guaranteed that
8868 -- the derived type is declared within the generic body of
8869 -- the generic unit declaring the formal type.
8871 if Is_Generic_Type (Ancestor_Type)
8872 and then Enclosing_Generic_Body (Ancestor_Type) /=
8873 Enclosing_Generic_Body (Derived_Type)
8874 then
8875 Error_Msg_NE
8876 ("parent type of& must not be descendant of formal type"
8877 & " of an enclosing generic body",
8878 Indic, Derived_Type);
8879 end if;
8880 end;
8881 end if;
8883 elsif Type_Access_Level (Derived_Type) /=
8884 Type_Access_Level (Parent_Type)
8885 and then not Is_Generic_Type (Derived_Type)
8886 then
8887 if Is_Controlled (Parent_Type) then
8888 Error_Msg_N
8889 ("controlled type must be declared at the library level",
8890 Indic);
8891 else
8892 Error_Msg_N
8893 ("type extension at deeper accessibility level than parent",
8894 Indic);
8895 end if;
8897 else
8898 declare
8899 GB : constant Node_Id := Enclosing_Generic_Body (Derived_Type);
8900 begin
8901 if Present (GB)
8902 and then GB /= Enclosing_Generic_Body (Parent_Base)
8903 then
8904 Error_Msg_NE
8905 ("parent type of& must not be outside generic body"
8906 & " (RM 3.9.1(4))",
8907 Indic, Derived_Type);
8908 end if;
8909 end;
8910 end if;
8911 end if;
8913 -- Ada 2005 (AI-251)
8915 if Ada_Version >= Ada_2005 and then Is_Tagged then
8917 -- "The declaration of a specific descendant of an interface type
8918 -- freezes the interface type" (RM 13.14).
8920 declare
8921 Iface : Node_Id;
8922 begin
8923 if Is_Non_Empty_List (Interface_List (Type_Def)) then
8924 Iface := First (Interface_List (Type_Def));
8925 while Present (Iface) loop
8926 Freeze_Before (N, Etype (Iface));
8927 Next (Iface);
8928 end loop;
8929 end if;
8930 end;
8931 end if;
8933 -- STEP 1b : preliminary cleanup of the full view of private types
8935 -- If the type is already marked as having discriminants, then it's the
8936 -- completion of a private type or private extension and we need to
8937 -- retain the discriminants from the partial view if the current
8938 -- declaration has Discriminant_Specifications so that we can verify
8939 -- conformance. However, we must remove any existing components that
8940 -- were inherited from the parent (and attached in Copy_And_Swap)
8941 -- because the full type inherits all appropriate components anyway, and
8942 -- we do not want the partial view's components interfering.
8944 if Has_Discriminants (Derived_Type) and then Discriminant_Specs then
8945 Discrim := First_Discriminant (Derived_Type);
8946 loop
8947 Last_Discrim := Discrim;
8948 Next_Discriminant (Discrim);
8949 exit when No (Discrim);
8950 end loop;
8952 Set_Last_Entity (Derived_Type, Last_Discrim);
8954 -- In all other cases wipe out the list of inherited components (even
8955 -- inherited discriminants), it will be properly rebuilt here.
8957 else
8958 Set_First_Entity (Derived_Type, Empty);
8959 Set_Last_Entity (Derived_Type, Empty);
8960 end if;
8962 -- STEP 1c: Initialize some flags for the Derived_Type
8964 -- The following flags must be initialized here so that
8965 -- Process_Discriminants can check that discriminants of tagged types do
8966 -- not have a default initial value and that access discriminants are
8967 -- only specified for limited records. For completeness, these flags are
8968 -- also initialized along with all the other flags below.
8970 -- AI-419: Limitedness is not inherited from an interface parent, so to
8971 -- be limited in that case the type must be explicitly declared as
8972 -- limited. However, task and protected interfaces are always limited.
8974 if Limited_Present (Type_Def) then
8975 Set_Is_Limited_Record (Derived_Type);
8977 elsif Is_Limited_Record (Parent_Type)
8978 or else (Present (Full_View (Parent_Type))
8979 and then Is_Limited_Record (Full_View (Parent_Type)))
8980 then
8981 if not Is_Interface (Parent_Type)
8982 or else Is_Synchronized_Interface (Parent_Type)
8983 or else Is_Protected_Interface (Parent_Type)
8984 or else Is_Task_Interface (Parent_Type)
8985 then
8986 Set_Is_Limited_Record (Derived_Type);
8987 end if;
8988 end if;
8990 -- STEP 2a: process discriminants of derived type if any
8992 Push_Scope (Derived_Type);
8994 if Discriminant_Specs then
8995 Set_Has_Unknown_Discriminants (Derived_Type, False);
8997 -- The following call initializes fields Has_Discriminants and
8998 -- Discriminant_Constraint, unless we are processing the completion
8999 -- of a private type declaration.
9001 Check_Or_Process_Discriminants (N, Derived_Type);
9003 -- For untagged types, the constraint on the Parent_Type must be
9004 -- present and is used to rename the discriminants.
9006 if not Is_Tagged and then not Has_Discriminants (Parent_Type) then
9007 Error_Msg_N ("untagged parent must have discriminants", Indic);
9009 elsif not Is_Tagged and then not Constraint_Present then
9010 Error_Msg_N
9011 ("discriminant constraint needed for derived untagged records",
9012 Indic);
9014 -- Otherwise the parent subtype must be constrained unless we have a
9015 -- private extension.
9017 elsif not Constraint_Present
9018 and then not Private_Extension
9019 and then not Is_Constrained (Parent_Type)
9020 then
9021 Error_Msg_N
9022 ("unconstrained type not allowed in this context", Indic);
9024 elsif Constraint_Present then
9025 -- The following call sets the field Corresponding_Discriminant
9026 -- for the discriminants in the Derived_Type.
9028 Discs := Build_Discriminant_Constraints (Parent_Type, Indic, True);
9030 -- For untagged types all new discriminants must rename
9031 -- discriminants in the parent. For private extensions new
9032 -- discriminants cannot rename old ones (implied by [7.3(13)]).
9034 Discrim := First_Discriminant (Derived_Type);
9035 while Present (Discrim) loop
9036 if not Is_Tagged
9037 and then No (Corresponding_Discriminant (Discrim))
9038 then
9039 Error_Msg_N
9040 ("new discriminants must constrain old ones", Discrim);
9042 elsif Private_Extension
9043 and then Present (Corresponding_Discriminant (Discrim))
9044 then
9045 Error_Msg_N
9046 ("only static constraints allowed for parent"
9047 & " discriminants in the partial view", Indic);
9048 exit;
9049 end if;
9051 -- If a new discriminant is used in the constraint, then its
9052 -- subtype must be statically compatible with the parent
9053 -- discriminant's subtype (3.7(15)).
9055 -- However, if the record contains an array constrained by
9056 -- the discriminant but with some different bound, the compiler
9057 -- tries to create a smaller range for the discriminant type.
9058 -- (See exp_ch3.Adjust_Discriminants). In this case, where
9059 -- the discriminant type is a scalar type, the check must use
9060 -- the original discriminant type in the parent declaration.
9062 declare
9063 Corr_Disc : constant Entity_Id :=
9064 Corresponding_Discriminant (Discrim);
9065 Disc_Type : constant Entity_Id := Etype (Discrim);
9066 Corr_Type : Entity_Id;
9068 begin
9069 if Present (Corr_Disc) then
9070 if Is_Scalar_Type (Disc_Type) then
9071 Corr_Type :=
9072 Entity (Discriminant_Type (Parent (Corr_Disc)));
9073 else
9074 Corr_Type := Etype (Corr_Disc);
9075 end if;
9077 if not
9078 Subtypes_Statically_Compatible (Disc_Type, Corr_Type)
9079 then
9080 Error_Msg_N
9081 ("subtype must be compatible "
9082 & "with parent discriminant",
9083 Discrim);
9084 end if;
9085 end if;
9086 end;
9088 Next_Discriminant (Discrim);
9089 end loop;
9091 -- Check whether the constraints of the full view statically
9092 -- match those imposed by the parent subtype [7.3(13)].
9094 if Present (Stored_Constraint (Derived_Type)) then
9095 declare
9096 C1, C2 : Elmt_Id;
9098 begin
9099 C1 := First_Elmt (Discs);
9100 C2 := First_Elmt (Stored_Constraint (Derived_Type));
9101 while Present (C1) and then Present (C2) loop
9102 if not
9103 Fully_Conformant_Expressions (Node (C1), Node (C2))
9104 then
9105 Error_Msg_N
9106 ("not conformant with previous declaration",
9107 Node (C1));
9108 end if;
9110 Next_Elmt (C1);
9111 Next_Elmt (C2);
9112 end loop;
9113 end;
9114 end if;
9115 end if;
9117 -- STEP 2b: No new discriminants, inherit discriminants if any
9119 else
9120 if Private_Extension then
9121 Set_Has_Unknown_Discriminants
9122 (Derived_Type,
9123 Has_Unknown_Discriminants (Parent_Type)
9124 or else Unknown_Discriminants_Present (N));
9126 -- The partial view of the parent may have unknown discriminants,
9127 -- but if the full view has discriminants and the parent type is
9128 -- in scope they must be inherited.
9130 elsif Has_Unknown_Discriminants (Parent_Type)
9131 and then
9132 (not Has_Discriminants (Parent_Type)
9133 or else not In_Open_Scopes (Scope (Parent_Base)))
9134 then
9135 Set_Has_Unknown_Discriminants (Derived_Type);
9136 end if;
9138 if not Has_Unknown_Discriminants (Derived_Type)
9139 and then not Has_Unknown_Discriminants (Parent_Base)
9140 and then Has_Discriminants (Parent_Type)
9141 then
9142 Inherit_Discrims := True;
9143 Set_Has_Discriminants
9144 (Derived_Type, True);
9145 Set_Discriminant_Constraint
9146 (Derived_Type, Discriminant_Constraint (Parent_Base));
9147 end if;
9149 -- The following test is true for private types (remember
9150 -- transformation 5. is not applied to those) and in an error
9151 -- situation.
9153 if Constraint_Present then
9154 Discs := Build_Discriminant_Constraints (Parent_Type, Indic);
9155 end if;
9157 -- For now mark a new derived type as constrained only if it has no
9158 -- discriminants. At the end of Build_Derived_Record_Type we properly
9159 -- set this flag in the case of private extensions. See comments in
9160 -- point 9. just before body of Build_Derived_Record_Type.
9162 Set_Is_Constrained
9163 (Derived_Type,
9164 not (Inherit_Discrims
9165 or else Has_Unknown_Discriminants (Derived_Type)));
9166 end if;
9168 -- STEP 3: initialize fields of derived type
9170 Set_Is_Tagged_Type (Derived_Type, Is_Tagged);
9171 Set_Stored_Constraint (Derived_Type, No_Elist);
9173 -- Ada 2005 (AI-251): Private type-declarations can implement interfaces
9174 -- but cannot be interfaces
9176 if not Private_Extension
9177 and then Ekind (Derived_Type) /= E_Private_Type
9178 and then Ekind (Derived_Type) /= E_Limited_Private_Type
9179 then
9180 if Interface_Present (Type_Def) then
9181 Analyze_Interface_Declaration (Derived_Type, Type_Def);
9182 end if;
9184 Set_Interfaces (Derived_Type, No_Elist);
9185 end if;
9187 -- Fields inherited from the Parent_Type
9189 Set_Has_Specified_Layout
9190 (Derived_Type, Has_Specified_Layout (Parent_Type));
9191 Set_Is_Limited_Composite
9192 (Derived_Type, Is_Limited_Composite (Parent_Type));
9193 Set_Is_Private_Composite
9194 (Derived_Type, Is_Private_Composite (Parent_Type));
9196 if Is_Tagged_Type (Parent_Type) then
9197 Set_No_Tagged_Streams_Pragma
9198 (Derived_Type, No_Tagged_Streams_Pragma (Parent_Type));
9199 end if;
9201 -- Fields inherited from the Parent_Base
9203 Set_Has_Controlled_Component
9204 (Derived_Type, Has_Controlled_Component (Parent_Base));
9205 Set_Has_Non_Standard_Rep
9206 (Derived_Type, Has_Non_Standard_Rep (Parent_Base));
9207 Set_Has_Primitive_Operations
9208 (Derived_Type, Has_Primitive_Operations (Parent_Base));
9210 -- Set fields for private derived types
9212 if Is_Private_Type (Derived_Type) then
9213 Set_Depends_On_Private (Derived_Type, True);
9214 Set_Private_Dependents (Derived_Type, New_Elmt_List);
9215 end if;
9217 -- Inherit fields for non-private types. If this is the completion of a
9218 -- derivation from a private type, the parent itself is private and the
9219 -- attributes come from its full view, which must be present.
9221 if Is_Record_Type (Derived_Type) then
9222 declare
9223 Parent_Full : Entity_Id;
9225 begin
9226 if Is_Private_Type (Parent_Base)
9227 and then not Is_Record_Type (Parent_Base)
9228 then
9229 Parent_Full := Full_View (Parent_Base);
9230 else
9231 Parent_Full := Parent_Base;
9232 end if;
9234 Set_Component_Alignment
9235 (Derived_Type, Component_Alignment (Parent_Full));
9236 Set_C_Pass_By_Copy
9237 (Derived_Type, C_Pass_By_Copy (Parent_Full));
9238 Set_Has_Complex_Representation
9239 (Derived_Type, Has_Complex_Representation (Parent_Full));
9241 -- For untagged types, inherit the layout by default to avoid
9242 -- costly changes of representation for type conversions.
9244 if not Is_Tagged then
9245 Set_Is_Packed (Derived_Type, Is_Packed (Parent_Full));
9246 Set_No_Reordering (Derived_Type, No_Reordering (Parent_Full));
9247 end if;
9248 end;
9249 end if;
9251 -- Set fields for tagged types
9253 if Is_Tagged then
9254 Set_Direct_Primitive_Operations (Derived_Type, New_Elmt_List);
9256 -- All tagged types defined in Ada.Finalization are controlled
9258 if Chars (Scope (Derived_Type)) = Name_Finalization
9259 and then Chars (Scope (Scope (Derived_Type))) = Name_Ada
9260 and then Scope (Scope (Scope (Derived_Type))) = Standard_Standard
9261 then
9262 Set_Is_Controlled_Active (Derived_Type);
9263 else
9264 Set_Is_Controlled_Active
9265 (Derived_Type, Is_Controlled_Active (Parent_Base));
9266 end if;
9268 -- Minor optimization: there is no need to generate the class-wide
9269 -- entity associated with an underlying record view.
9271 if not Is_Underlying_Record_View (Derived_Type) then
9272 Make_Class_Wide_Type (Derived_Type);
9273 end if;
9275 Set_Is_Abstract_Type (Derived_Type, Abstract_Present (Type_Def));
9277 if Has_Discriminants (Derived_Type)
9278 and then Constraint_Present
9279 then
9280 Set_Stored_Constraint
9281 (Derived_Type, Expand_To_Stored_Constraint (Parent_Base, Discs));
9282 end if;
9284 if Ada_Version >= Ada_2005 then
9285 declare
9286 Ifaces_List : Elist_Id;
9288 begin
9289 -- Checks rules 3.9.4 (13/2 and 14/2)
9291 if Comes_From_Source (Derived_Type)
9292 and then not Is_Private_Type (Derived_Type)
9293 and then Is_Interface (Parent_Type)
9294 and then not Is_Interface (Derived_Type)
9295 then
9296 if Is_Task_Interface (Parent_Type) then
9297 Error_Msg_N
9298 ("(Ada 2005) task type required (RM 3.9.4 (13.2))",
9299 Derived_Type);
9301 elsif Is_Protected_Interface (Parent_Type) then
9302 Error_Msg_N
9303 ("(Ada 2005) protected type required (RM 3.9.4 (14.2))",
9304 Derived_Type);
9305 end if;
9306 end if;
9308 -- Check ARM rules 3.9.4 (15/2), 9.1 (9.d/2) and 9.4 (11.d/2)
9310 Check_Interfaces (N, Type_Def);
9312 -- Ada 2005 (AI-251): Collect the list of progenitors that are
9313 -- not already in the parents.
9315 Collect_Interfaces
9316 (T => Derived_Type,
9317 Ifaces_List => Ifaces_List,
9318 Exclude_Parents => True);
9320 Set_Interfaces (Derived_Type, Ifaces_List);
9322 -- If the derived type is the anonymous type created for
9323 -- a declaration whose parent has a constraint, propagate
9324 -- the interface list to the source type. This must be done
9325 -- prior to the completion of the analysis of the source type
9326 -- because the components in the extension may contain current
9327 -- instances whose legality depends on some ancestor.
9329 if Is_Itype (Derived_Type) then
9330 declare
9331 Def : constant Node_Id :=
9332 Associated_Node_For_Itype (Derived_Type);
9333 begin
9334 if Present (Def)
9335 and then Nkind (Def) = N_Full_Type_Declaration
9336 then
9337 Set_Interfaces
9338 (Defining_Identifier (Def), Ifaces_List);
9339 end if;
9340 end;
9341 end if;
9343 -- A type extension is automatically Ghost when one of its
9344 -- progenitors is Ghost (SPARK RM 6.9(9)). This property is
9345 -- also inherited when the parent type is Ghost, but this is
9346 -- done in Build_Derived_Type as the mechanism also handles
9347 -- untagged derivations.
9349 if Implements_Ghost_Interface (Derived_Type) then
9350 Set_Is_Ghost_Entity (Derived_Type);
9351 end if;
9352 end;
9353 end if;
9354 end if;
9356 -- STEP 4: Inherit components from the parent base and constrain them.
9357 -- Apply the second transformation described in point 6. above.
9359 if (not Is_Empty_Elmt_List (Discs) or else Inherit_Discrims)
9360 or else not Has_Discriminants (Parent_Type)
9361 or else not Is_Constrained (Parent_Type)
9362 then
9363 Constrs := Discs;
9364 else
9365 Constrs := Discriminant_Constraint (Parent_Type);
9366 end if;
9368 Assoc_List :=
9369 Inherit_Components
9370 (N, Parent_Base, Derived_Type, Is_Tagged, Inherit_Discrims, Constrs);
9372 -- STEP 5a: Copy the parent record declaration for untagged types
9374 Set_Has_Implicit_Dereference
9375 (Derived_Type, Has_Implicit_Dereference (Parent_Type));
9377 if not Is_Tagged then
9379 -- Discriminant_Constraint (Derived_Type) has been properly
9380 -- constructed. Save it and temporarily set it to Empty because we
9381 -- do not want the call to New_Copy_Tree below to mess this list.
9383 if Has_Discriminants (Derived_Type) then
9384 Save_Discr_Constr := Discriminant_Constraint (Derived_Type);
9385 Set_Discriminant_Constraint (Derived_Type, No_Elist);
9386 else
9387 Save_Discr_Constr := No_Elist;
9388 end if;
9390 -- Save the Etype field of Derived_Type. It is correctly set now,
9391 -- but the call to New_Copy tree may remap it to point to itself,
9392 -- which is not what we want. Ditto for the Next_Entity field.
9394 Save_Etype := Etype (Derived_Type);
9395 Save_Next_Entity := Next_Entity (Derived_Type);
9397 -- Assoc_List maps all stored discriminants in the Parent_Base to
9398 -- stored discriminants in the Derived_Type. It is fundamental that
9399 -- no types or itypes with discriminants other than the stored
9400 -- discriminants appear in the entities declared inside
9401 -- Derived_Type, since the back end cannot deal with it.
9403 New_Decl :=
9404 New_Copy_Tree
9405 (Parent (Parent_Base), Map => Assoc_List, New_Sloc => Loc);
9406 Copy_Dimensions_Of_Components (Derived_Type);
9408 -- Restore the fields saved prior to the New_Copy_Tree call
9409 -- and compute the stored constraint.
9411 Set_Etype (Derived_Type, Save_Etype);
9412 Set_Next_Entity (Derived_Type, Save_Next_Entity);
9414 if Has_Discriminants (Derived_Type) then
9415 Set_Discriminant_Constraint
9416 (Derived_Type, Save_Discr_Constr);
9417 Set_Stored_Constraint
9418 (Derived_Type, Expand_To_Stored_Constraint (Parent_Type, Discs));
9419 Replace_Components (Derived_Type, New_Decl);
9420 end if;
9422 -- Insert the new derived type declaration
9424 Rewrite (N, New_Decl);
9426 -- STEP 5b: Complete the processing for record extensions in generics
9428 -- There is no completion for record extensions declared in the
9429 -- parameter part of a generic, so we need to complete processing for
9430 -- these generic record extensions here. The Record_Type_Definition call
9431 -- will change the Ekind of the components from E_Void to E_Component.
9433 elsif Private_Extension and then Is_Generic_Type (Derived_Type) then
9434 Record_Type_Definition (Empty, Derived_Type);
9436 -- STEP 5c: Process the record extension for non private tagged types
9438 elsif not Private_Extension then
9439 Expand_Record_Extension (Derived_Type, Type_Def);
9441 -- Note : previously in ASIS mode we set the Parent_Subtype of the
9442 -- derived type to propagate some semantic information. This led
9443 -- to other ASIS failures and has been removed.
9445 -- Ada 2005 (AI-251): Addition of the Tag corresponding to all the
9446 -- implemented interfaces if we are in expansion mode
9448 if Expander_Active
9449 and then Has_Interfaces (Derived_Type)
9450 then
9451 Add_Interface_Tag_Components (N, Derived_Type);
9452 end if;
9454 -- Analyze the record extension
9456 Record_Type_Definition
9457 (Record_Extension_Part (Type_Def), Derived_Type);
9458 end if;
9460 End_Scope;
9462 -- Nothing else to do if there is an error in the derivation.
9463 -- An unusual case: the full view may be derived from a type in an
9464 -- instance, when the partial view was used illegally as an actual
9465 -- in that instance, leading to a circular definition.
9467 if Etype (Derived_Type) = Any_Type
9468 or else Etype (Parent_Type) = Derived_Type
9469 then
9470 return;
9471 end if;
9473 -- Set delayed freeze and then derive subprograms, we need to do
9474 -- this in this order so that derived subprograms inherit the
9475 -- derived freeze if necessary.
9477 Set_Has_Delayed_Freeze (Derived_Type);
9479 if Derive_Subps then
9480 Derive_Subprograms (Parent_Type, Derived_Type);
9481 end if;
9483 -- If we have a private extension which defines a constrained derived
9484 -- type mark as constrained here after we have derived subprograms. See
9485 -- comment on point 9. just above the body of Build_Derived_Record_Type.
9487 if Private_Extension and then Inherit_Discrims then
9488 if Constraint_Present and then not Is_Empty_Elmt_List (Discs) then
9489 Set_Is_Constrained (Derived_Type, True);
9490 Set_Discriminant_Constraint (Derived_Type, Discs);
9492 elsif Is_Constrained (Parent_Type) then
9493 Set_Is_Constrained
9494 (Derived_Type, True);
9495 Set_Discriminant_Constraint
9496 (Derived_Type, Discriminant_Constraint (Parent_Type));
9497 end if;
9498 end if;
9500 -- Update the class-wide type, which shares the now-completed entity
9501 -- list with its specific type. In case of underlying record views,
9502 -- we do not generate the corresponding class wide entity.
9504 if Is_Tagged
9505 and then not Is_Underlying_Record_View (Derived_Type)
9506 then
9507 Set_First_Entity
9508 (Class_Wide_Type (Derived_Type), First_Entity (Derived_Type));
9509 Set_Last_Entity
9510 (Class_Wide_Type (Derived_Type), Last_Entity (Derived_Type));
9511 end if;
9513 Check_Function_Writable_Actuals (N);
9514 end Build_Derived_Record_Type;
9516 ------------------------
9517 -- Build_Derived_Type --
9518 ------------------------
9520 procedure Build_Derived_Type
9521 (N : Node_Id;
9522 Parent_Type : Entity_Id;
9523 Derived_Type : Entity_Id;
9524 Is_Completion : Boolean;
9525 Derive_Subps : Boolean := True)
9527 Parent_Base : constant Entity_Id := Base_Type (Parent_Type);
9529 begin
9530 -- Set common attributes
9532 Set_Scope (Derived_Type, Current_Scope);
9533 Set_Etype (Derived_Type, Parent_Base);
9534 Set_Ekind (Derived_Type, Ekind (Parent_Base));
9535 Propagate_Concurrent_Flags (Derived_Type, Parent_Base);
9537 Set_Size_Info (Derived_Type, Parent_Type);
9538 Set_RM_Size (Derived_Type, RM_Size (Parent_Type));
9540 Set_Is_Controlled_Active
9541 (Derived_Type, Is_Controlled_Active (Parent_Type));
9543 Set_Disable_Controlled (Derived_Type, Disable_Controlled (Parent_Type));
9544 Set_Is_Tagged_Type (Derived_Type, Is_Tagged_Type (Parent_Type));
9545 Set_Is_Volatile (Derived_Type, Is_Volatile (Parent_Type));
9547 if Is_Tagged_Type (Derived_Type) then
9548 Set_No_Tagged_Streams_Pragma
9549 (Derived_Type, No_Tagged_Streams_Pragma (Parent_Type));
9550 end if;
9552 -- If the parent has primitive routines, set the derived type link
9554 if Has_Primitive_Operations (Parent_Type) then
9555 Set_Derived_Type_Link (Parent_Base, Derived_Type);
9556 end if;
9558 -- If the parent type is a private subtype, the convention on the base
9559 -- type may be set in the private part, and not propagated to the
9560 -- subtype until later, so we obtain the convention from the base type.
9562 Set_Convention (Derived_Type, Convention (Parent_Base));
9564 -- Set SSO default for record or array type
9566 if (Is_Array_Type (Derived_Type) or else Is_Record_Type (Derived_Type))
9567 and then Is_Base_Type (Derived_Type)
9568 then
9569 Set_Default_SSO (Derived_Type);
9570 end if;
9572 -- A derived type inherits the Default_Initial_Condition pragma coming
9573 -- from any parent type within the derivation chain.
9575 if Has_DIC (Parent_Type) then
9576 Set_Has_Inherited_DIC (Derived_Type);
9577 end if;
9579 -- A derived type inherits any class-wide invariants coming from a
9580 -- parent type or an interface. Note that the invariant procedure of
9581 -- the parent type should not be inherited because the derived type may
9582 -- define invariants of its own.
9584 if not Is_Interface (Derived_Type) then
9585 if Has_Inherited_Invariants (Parent_Type)
9586 or else Has_Inheritable_Invariants (Parent_Type)
9587 then
9588 Set_Has_Inherited_Invariants (Derived_Type);
9590 elsif Is_Concurrent_Type (Derived_Type)
9591 or else Is_Tagged_Type (Derived_Type)
9592 then
9593 declare
9594 Iface : Entity_Id;
9595 Ifaces : Elist_Id;
9596 Iface_Elmt : Elmt_Id;
9598 begin
9599 Collect_Interfaces
9600 (T => Derived_Type,
9601 Ifaces_List => Ifaces,
9602 Exclude_Parents => True);
9604 if Present (Ifaces) then
9605 Iface_Elmt := First_Elmt (Ifaces);
9606 while Present (Iface_Elmt) loop
9607 Iface := Node (Iface_Elmt);
9609 if Has_Inheritable_Invariants (Iface) then
9610 Set_Has_Inherited_Invariants (Derived_Type);
9611 exit;
9612 end if;
9614 Next_Elmt (Iface_Elmt);
9615 end loop;
9616 end if;
9617 end;
9618 end if;
9619 end if;
9621 -- We similarly inherit predicates. Note that for scalar derived types
9622 -- the predicate is inherited from the first subtype, and not from its
9623 -- (anonymous) base type.
9625 if Has_Predicates (Parent_Type)
9626 or else Has_Predicates (First_Subtype (Parent_Type))
9627 then
9628 Set_Has_Predicates (Derived_Type);
9629 end if;
9631 -- The derived type inherits representation clauses from the parent
9632 -- type, and from any interfaces.
9634 Inherit_Rep_Item_Chain (Derived_Type, Parent_Type);
9636 declare
9637 Iface : Node_Id := First (Abstract_Interface_List (Derived_Type));
9638 begin
9639 while Present (Iface) loop
9640 Inherit_Rep_Item_Chain (Derived_Type, Entity (Iface));
9641 Next (Iface);
9642 end loop;
9643 end;
9645 -- If the parent type has delayed rep aspects, then mark the derived
9646 -- type as possibly inheriting a delayed rep aspect.
9648 if Has_Delayed_Rep_Aspects (Parent_Type) then
9649 Set_May_Inherit_Delayed_Rep_Aspects (Derived_Type);
9650 end if;
9652 -- A derived type becomes Ghost when its parent type is also Ghost
9653 -- (SPARK RM 6.9(9)). Note that the Ghost-related attributes are not
9654 -- directly inherited because the Ghost policy in effect may differ.
9656 if Is_Ghost_Entity (Parent_Type) then
9657 Set_Is_Ghost_Entity (Derived_Type);
9658 end if;
9660 -- Type dependent processing
9662 case Ekind (Parent_Type) is
9663 when Numeric_Kind =>
9664 Build_Derived_Numeric_Type (N, Parent_Type, Derived_Type);
9666 when Array_Kind =>
9667 Build_Derived_Array_Type (N, Parent_Type, Derived_Type);
9669 when Class_Wide_Kind
9670 | E_Record_Subtype
9671 | E_Record_Type
9673 Build_Derived_Record_Type
9674 (N, Parent_Type, Derived_Type, Derive_Subps);
9675 return;
9677 when Enumeration_Kind =>
9678 Build_Derived_Enumeration_Type (N, Parent_Type, Derived_Type);
9680 when Access_Kind =>
9681 Build_Derived_Access_Type (N, Parent_Type, Derived_Type);
9683 when Incomplete_Or_Private_Kind =>
9684 Build_Derived_Private_Type
9685 (N, Parent_Type, Derived_Type, Is_Completion, Derive_Subps);
9687 -- For discriminated types, the derivation includes deriving
9688 -- primitive operations. For others it is done below.
9690 if Is_Tagged_Type (Parent_Type)
9691 or else Has_Discriminants (Parent_Type)
9692 or else (Present (Full_View (Parent_Type))
9693 and then Has_Discriminants (Full_View (Parent_Type)))
9694 then
9695 return;
9696 end if;
9698 when Concurrent_Kind =>
9699 Build_Derived_Concurrent_Type (N, Parent_Type, Derived_Type);
9701 when others =>
9702 raise Program_Error;
9703 end case;
9705 -- Nothing more to do if some error occurred
9707 if Etype (Derived_Type) = Any_Type then
9708 return;
9709 end if;
9711 -- Set delayed freeze and then derive subprograms, we need to do this
9712 -- in this order so that derived subprograms inherit the derived freeze
9713 -- if necessary.
9715 Set_Has_Delayed_Freeze (Derived_Type);
9717 if Derive_Subps then
9718 Derive_Subprograms (Parent_Type, Derived_Type);
9719 end if;
9721 Set_Has_Primitive_Operations
9722 (Base_Type (Derived_Type), Has_Primitive_Operations (Parent_Type));
9723 end Build_Derived_Type;
9725 -----------------------
9726 -- Build_Discriminal --
9727 -----------------------
9729 procedure Build_Discriminal (Discrim : Entity_Id) is
9730 D_Minal : Entity_Id;
9731 CR_Disc : Entity_Id;
9733 begin
9734 -- A discriminal has the same name as the discriminant
9736 D_Minal := Make_Defining_Identifier (Sloc (Discrim), Chars (Discrim));
9738 Set_Ekind (D_Minal, E_In_Parameter);
9739 Set_Mechanism (D_Minal, Default_Mechanism);
9740 Set_Etype (D_Minal, Etype (Discrim));
9741 Set_Scope (D_Minal, Current_Scope);
9742 Set_Parent (D_Minal, Parent (Discrim));
9744 Set_Discriminal (Discrim, D_Minal);
9745 Set_Discriminal_Link (D_Minal, Discrim);
9747 -- For task types, build at once the discriminants of the corresponding
9748 -- record, which are needed if discriminants are used in entry defaults
9749 -- and in family bounds.
9751 if Is_Concurrent_Type (Current_Scope)
9752 or else
9753 Is_Limited_Type (Current_Scope)
9754 then
9755 CR_Disc := Make_Defining_Identifier (Sloc (Discrim), Chars (Discrim));
9757 Set_Ekind (CR_Disc, E_In_Parameter);
9758 Set_Mechanism (CR_Disc, Default_Mechanism);
9759 Set_Etype (CR_Disc, Etype (Discrim));
9760 Set_Scope (CR_Disc, Current_Scope);
9761 Set_Discriminal_Link (CR_Disc, Discrim);
9762 Set_CR_Discriminant (Discrim, CR_Disc);
9763 end if;
9764 end Build_Discriminal;
9766 ------------------------------------
9767 -- Build_Discriminant_Constraints --
9768 ------------------------------------
9770 function Build_Discriminant_Constraints
9771 (T : Entity_Id;
9772 Def : Node_Id;
9773 Derived_Def : Boolean := False) return Elist_Id
9775 C : constant Node_Id := Constraint (Def);
9776 Nb_Discr : constant Nat := Number_Discriminants (T);
9778 Discr_Expr : array (1 .. Nb_Discr) of Node_Id := (others => Empty);
9779 -- Saves the expression corresponding to a given discriminant in T
9781 function Pos_Of_Discr (T : Entity_Id; D : Entity_Id) return Nat;
9782 -- Return the Position number within array Discr_Expr of a discriminant
9783 -- D within the discriminant list of the discriminated type T.
9785 procedure Process_Discriminant_Expression
9786 (Expr : Node_Id;
9787 D : Entity_Id);
9788 -- If this is a discriminant constraint on a partial view, do not
9789 -- generate an overflow check on the discriminant expression. The check
9790 -- will be generated when constraining the full view. Otherwise the
9791 -- backend creates duplicate symbols for the temporaries corresponding
9792 -- to the expressions to be checked, causing spurious assembler errors.
9794 ------------------
9795 -- Pos_Of_Discr --
9796 ------------------
9798 function Pos_Of_Discr (T : Entity_Id; D : Entity_Id) return Nat is
9799 Disc : Entity_Id;
9801 begin
9802 Disc := First_Discriminant (T);
9803 for J in Discr_Expr'Range loop
9804 if Disc = D then
9805 return J;
9806 end if;
9808 Next_Discriminant (Disc);
9809 end loop;
9811 -- Note: Since this function is called on discriminants that are
9812 -- known to belong to the discriminated type, falling through the
9813 -- loop with no match signals an internal compiler error.
9815 raise Program_Error;
9816 end Pos_Of_Discr;
9818 -------------------------------------
9819 -- Process_Discriminant_Expression --
9820 -------------------------------------
9822 procedure Process_Discriminant_Expression
9823 (Expr : Node_Id;
9824 D : Entity_Id)
9826 BDT : constant Entity_Id := Base_Type (Etype (D));
9828 begin
9829 -- If this is a discriminant constraint on a partial view, do
9830 -- not generate an overflow on the discriminant expression. The
9831 -- check will be generated when constraining the full view.
9833 if Is_Private_Type (T)
9834 and then Present (Full_View (T))
9835 then
9836 Analyze_And_Resolve (Expr, BDT, Suppress => Overflow_Check);
9837 else
9838 Analyze_And_Resolve (Expr, BDT);
9839 end if;
9840 end Process_Discriminant_Expression;
9842 -- Declarations local to Build_Discriminant_Constraints
9844 Discr : Entity_Id;
9845 E : Entity_Id;
9846 Elist : constant Elist_Id := New_Elmt_List;
9848 Constr : Node_Id;
9849 Expr : Node_Id;
9850 Id : Node_Id;
9851 Position : Nat;
9852 Found : Boolean;
9854 Discrim_Present : Boolean := False;
9856 -- Start of processing for Build_Discriminant_Constraints
9858 begin
9859 -- The following loop will process positional associations only.
9860 -- For a positional association, the (single) discriminant is
9861 -- implicitly specified by position, in textual order (RM 3.7.2).
9863 Discr := First_Discriminant (T);
9864 Constr := First (Constraints (C));
9865 for D in Discr_Expr'Range loop
9866 exit when Nkind (Constr) = N_Discriminant_Association;
9868 if No (Constr) then
9869 Error_Msg_N ("too few discriminants given in constraint", C);
9870 return New_Elmt_List;
9872 elsif Nkind (Constr) = N_Range
9873 or else (Nkind (Constr) = N_Attribute_Reference
9874 and then Attribute_Name (Constr) = Name_Range)
9875 then
9876 Error_Msg_N
9877 ("a range is not a valid discriminant constraint", Constr);
9878 Discr_Expr (D) := Error;
9880 else
9881 Process_Discriminant_Expression (Constr, Discr);
9882 Discr_Expr (D) := Constr;
9883 end if;
9885 Next_Discriminant (Discr);
9886 Next (Constr);
9887 end loop;
9889 if No (Discr) and then Present (Constr) then
9890 Error_Msg_N ("too many discriminants given in constraint", Constr);
9891 return New_Elmt_List;
9892 end if;
9894 -- Named associations can be given in any order, but if both positional
9895 -- and named associations are used in the same discriminant constraint,
9896 -- then positional associations must occur first, at their normal
9897 -- position. Hence once a named association is used, the rest of the
9898 -- discriminant constraint must use only named associations.
9900 while Present (Constr) loop
9902 -- Positional association forbidden after a named association
9904 if Nkind (Constr) /= N_Discriminant_Association then
9905 Error_Msg_N ("positional association follows named one", Constr);
9906 return New_Elmt_List;
9908 -- Otherwise it is a named association
9910 else
9911 -- E records the type of the discriminants in the named
9912 -- association. All the discriminants specified in the same name
9913 -- association must have the same type.
9915 E := Empty;
9917 -- Search the list of discriminants in T to see if the simple name
9918 -- given in the constraint matches any of them.
9920 Id := First (Selector_Names (Constr));
9921 while Present (Id) loop
9922 Found := False;
9924 -- If Original_Discriminant is present, we are processing a
9925 -- generic instantiation and this is an instance node. We need
9926 -- to find the name of the corresponding discriminant in the
9927 -- actual record type T and not the name of the discriminant in
9928 -- the generic formal. Example:
9930 -- generic
9931 -- type G (D : int) is private;
9932 -- package P is
9933 -- subtype W is G (D => 1);
9934 -- end package;
9935 -- type Rec (X : int) is record ... end record;
9936 -- package Q is new P (G => Rec);
9938 -- At the point of the instantiation, formal type G is Rec
9939 -- and therefore when reanalyzing "subtype W is G (D => 1);"
9940 -- which really looks like "subtype W is Rec (D => 1);" at
9941 -- the point of instantiation, we want to find the discriminant
9942 -- that corresponds to D in Rec, i.e. X.
9944 if Present (Original_Discriminant (Id))
9945 and then In_Instance
9946 then
9947 Discr := Find_Corresponding_Discriminant (Id, T);
9948 Found := True;
9950 else
9951 Discr := First_Discriminant (T);
9952 while Present (Discr) loop
9953 if Chars (Discr) = Chars (Id) then
9954 Found := True;
9955 exit;
9956 end if;
9958 Next_Discriminant (Discr);
9959 end loop;
9961 if not Found then
9962 Error_Msg_N ("& does not match any discriminant", Id);
9963 return New_Elmt_List;
9965 -- If the parent type is a generic formal, preserve the
9966 -- name of the discriminant for subsequent instances.
9967 -- see comment at the beginning of this if statement.
9969 elsif Is_Generic_Type (Root_Type (T)) then
9970 Set_Original_Discriminant (Id, Discr);
9971 end if;
9972 end if;
9974 Position := Pos_Of_Discr (T, Discr);
9976 if Present (Discr_Expr (Position)) then
9977 Error_Msg_N ("duplicate constraint for discriminant&", Id);
9979 else
9980 -- Each discriminant specified in the same named association
9981 -- must be associated with a separate copy of the
9982 -- corresponding expression.
9984 if Present (Next (Id)) then
9985 Expr := New_Copy_Tree (Expression (Constr));
9986 Set_Parent (Expr, Parent (Expression (Constr)));
9987 else
9988 Expr := Expression (Constr);
9989 end if;
9991 Discr_Expr (Position) := Expr;
9992 Process_Discriminant_Expression (Expr, Discr);
9993 end if;
9995 -- A discriminant association with more than one discriminant
9996 -- name is only allowed if the named discriminants are all of
9997 -- the same type (RM 3.7.1(8)).
9999 if E = Empty then
10000 E := Base_Type (Etype (Discr));
10002 elsif Base_Type (Etype (Discr)) /= E then
10003 Error_Msg_N
10004 ("all discriminants in an association " &
10005 "must have the same type", Id);
10006 end if;
10008 Next (Id);
10009 end loop;
10010 end if;
10012 Next (Constr);
10013 end loop;
10015 -- A discriminant constraint must provide exactly one value for each
10016 -- discriminant of the type (RM 3.7.1(8)).
10018 for J in Discr_Expr'Range loop
10019 if No (Discr_Expr (J)) then
10020 Error_Msg_N ("too few discriminants given in constraint", C);
10021 return New_Elmt_List;
10022 end if;
10023 end loop;
10025 -- Determine if there are discriminant expressions in the constraint
10027 for J in Discr_Expr'Range loop
10028 if Denotes_Discriminant
10029 (Discr_Expr (J), Check_Concurrent => True)
10030 then
10031 Discrim_Present := True;
10032 end if;
10033 end loop;
10035 -- Build an element list consisting of the expressions given in the
10036 -- discriminant constraint and apply the appropriate checks. The list
10037 -- is constructed after resolving any named discriminant associations
10038 -- and therefore the expressions appear in the textual order of the
10039 -- discriminants.
10041 Discr := First_Discriminant (T);
10042 for J in Discr_Expr'Range loop
10043 if Discr_Expr (J) /= Error then
10044 Append_Elmt (Discr_Expr (J), Elist);
10046 -- If any of the discriminant constraints is given by a
10047 -- discriminant and we are in a derived type declaration we
10048 -- have a discriminant renaming. Establish link between new
10049 -- and old discriminant. The new discriminant has an implicit
10050 -- dereference if the old one does.
10052 if Denotes_Discriminant (Discr_Expr (J)) then
10053 if Derived_Def then
10054 declare
10055 New_Discr : constant Entity_Id := Entity (Discr_Expr (J));
10057 begin
10058 Set_Corresponding_Discriminant (New_Discr, Discr);
10059 Set_Has_Implicit_Dereference (New_Discr,
10060 Has_Implicit_Dereference (Discr));
10061 end;
10062 end if;
10064 -- Force the evaluation of non-discriminant expressions.
10065 -- If we have found a discriminant in the constraint 3.4(26)
10066 -- and 3.8(18) demand that no range checks are performed are
10067 -- after evaluation. If the constraint is for a component
10068 -- definition that has a per-object constraint, expressions are
10069 -- evaluated but not checked either. In all other cases perform
10070 -- a range check.
10072 else
10073 if Discrim_Present then
10074 null;
10076 elsif Nkind (Parent (Parent (Def))) = N_Component_Declaration
10077 and then Has_Per_Object_Constraint
10078 (Defining_Identifier (Parent (Parent (Def))))
10079 then
10080 null;
10082 elsif Is_Access_Type (Etype (Discr)) then
10083 Apply_Constraint_Check (Discr_Expr (J), Etype (Discr));
10085 else
10086 Apply_Range_Check (Discr_Expr (J), Etype (Discr));
10087 end if;
10089 Force_Evaluation (Discr_Expr (J));
10090 end if;
10092 -- Check that the designated type of an access discriminant's
10093 -- expression is not a class-wide type unless the discriminant's
10094 -- designated type is also class-wide.
10096 if Ekind (Etype (Discr)) = E_Anonymous_Access_Type
10097 and then not Is_Class_Wide_Type
10098 (Designated_Type (Etype (Discr)))
10099 and then Etype (Discr_Expr (J)) /= Any_Type
10100 and then Is_Class_Wide_Type
10101 (Designated_Type (Etype (Discr_Expr (J))))
10102 then
10103 Wrong_Type (Discr_Expr (J), Etype (Discr));
10105 elsif Is_Access_Type (Etype (Discr))
10106 and then not Is_Access_Constant (Etype (Discr))
10107 and then Is_Access_Type (Etype (Discr_Expr (J)))
10108 and then Is_Access_Constant (Etype (Discr_Expr (J)))
10109 then
10110 Error_Msg_NE
10111 ("constraint for discriminant& must be access to variable",
10112 Def, Discr);
10113 end if;
10114 end if;
10116 Next_Discriminant (Discr);
10117 end loop;
10119 return Elist;
10120 end Build_Discriminant_Constraints;
10122 ---------------------------------
10123 -- Build_Discriminated_Subtype --
10124 ---------------------------------
10126 procedure Build_Discriminated_Subtype
10127 (T : Entity_Id;
10128 Def_Id : Entity_Id;
10129 Elist : Elist_Id;
10130 Related_Nod : Node_Id;
10131 For_Access : Boolean := False)
10133 Has_Discrs : constant Boolean := Has_Discriminants (T);
10134 Constrained : constant Boolean :=
10135 (Has_Discrs
10136 and then not Is_Empty_Elmt_List (Elist)
10137 and then not Is_Class_Wide_Type (T))
10138 or else Is_Constrained (T);
10140 begin
10141 if Ekind (T) = E_Record_Type then
10142 if For_Access then
10143 Set_Ekind (Def_Id, E_Private_Subtype);
10144 Set_Is_For_Access_Subtype (Def_Id, True);
10145 else
10146 Set_Ekind (Def_Id, E_Record_Subtype);
10147 end if;
10149 -- Inherit preelaboration flag from base, for types for which it
10150 -- may have been set: records, private types, protected types.
10152 Set_Known_To_Have_Preelab_Init
10153 (Def_Id, Known_To_Have_Preelab_Init (T));
10155 elsif Ekind (T) = E_Task_Type then
10156 Set_Ekind (Def_Id, E_Task_Subtype);
10158 elsif Ekind (T) = E_Protected_Type then
10159 Set_Ekind (Def_Id, E_Protected_Subtype);
10160 Set_Known_To_Have_Preelab_Init
10161 (Def_Id, Known_To_Have_Preelab_Init (T));
10163 elsif Is_Private_Type (T) then
10164 Set_Ekind (Def_Id, Subtype_Kind (Ekind (T)));
10165 Set_Known_To_Have_Preelab_Init
10166 (Def_Id, Known_To_Have_Preelab_Init (T));
10168 -- Private subtypes may have private dependents
10170 Set_Private_Dependents (Def_Id, New_Elmt_List);
10172 elsif Is_Class_Wide_Type (T) then
10173 Set_Ekind (Def_Id, E_Class_Wide_Subtype);
10175 else
10176 -- Incomplete type. Attach subtype to list of dependents, to be
10177 -- completed with full view of parent type, unless is it the
10178 -- designated subtype of a record component within an init_proc.
10179 -- This last case arises for a component of an access type whose
10180 -- designated type is incomplete (e.g. a Taft Amendment type).
10181 -- The designated subtype is within an inner scope, and needs no
10182 -- elaboration, because only the access type is needed in the
10183 -- initialization procedure.
10185 if Ekind (T) = E_Incomplete_Type then
10186 Set_Ekind (Def_Id, E_Incomplete_Subtype);
10187 else
10188 Set_Ekind (Def_Id, Ekind (T));
10189 end if;
10191 if For_Access and then Within_Init_Proc then
10192 null;
10193 else
10194 Append_Elmt (Def_Id, Private_Dependents (T));
10195 end if;
10196 end if;
10198 Set_Etype (Def_Id, T);
10199 Init_Size_Align (Def_Id);
10200 Set_Has_Discriminants (Def_Id, Has_Discrs);
10201 Set_Is_Constrained (Def_Id, Constrained);
10203 Set_First_Entity (Def_Id, First_Entity (T));
10204 Set_Last_Entity (Def_Id, Last_Entity (T));
10205 Set_Has_Implicit_Dereference
10206 (Def_Id, Has_Implicit_Dereference (T));
10207 Set_Has_Pragma_Unreferenced_Objects
10208 (Def_Id, Has_Pragma_Unreferenced_Objects (T));
10210 -- If the subtype is the completion of a private declaration, there may
10211 -- have been representation clauses for the partial view, and they must
10212 -- be preserved. Build_Derived_Type chains the inherited clauses with
10213 -- the ones appearing on the extension. If this comes from a subtype
10214 -- declaration, all clauses are inherited.
10216 if No (First_Rep_Item (Def_Id)) then
10217 Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
10218 end if;
10220 if Is_Tagged_Type (T) then
10221 Set_Is_Tagged_Type (Def_Id);
10222 Set_No_Tagged_Streams_Pragma (Def_Id, No_Tagged_Streams_Pragma (T));
10223 Make_Class_Wide_Type (Def_Id);
10224 end if;
10226 Set_Stored_Constraint (Def_Id, No_Elist);
10228 if Has_Discrs then
10229 Set_Discriminant_Constraint (Def_Id, Elist);
10230 Set_Stored_Constraint_From_Discriminant_Constraint (Def_Id);
10231 end if;
10233 if Is_Tagged_Type (T) then
10235 -- Ada 2005 (AI-251): In case of concurrent types we inherit the
10236 -- concurrent record type (which has the list of primitive
10237 -- operations).
10239 if Ada_Version >= Ada_2005
10240 and then Is_Concurrent_Type (T)
10241 then
10242 Set_Corresponding_Record_Type (Def_Id,
10243 Corresponding_Record_Type (T));
10244 else
10245 Set_Direct_Primitive_Operations (Def_Id,
10246 Direct_Primitive_Operations (T));
10247 end if;
10249 Set_Is_Abstract_Type (Def_Id, Is_Abstract_Type (T));
10250 end if;
10252 -- Subtypes introduced by component declarations do not need to be
10253 -- marked as delayed, and do not get freeze nodes, because the semantics
10254 -- verifies that the parents of the subtypes are frozen before the
10255 -- enclosing record is frozen.
10257 if not Is_Type (Scope (Def_Id)) then
10258 Set_Depends_On_Private (Def_Id, Depends_On_Private (T));
10260 if Is_Private_Type (T)
10261 and then Present (Full_View (T))
10262 then
10263 Conditional_Delay (Def_Id, Full_View (T));
10264 else
10265 Conditional_Delay (Def_Id, T);
10266 end if;
10267 end if;
10269 if Is_Record_Type (T) then
10270 Set_Is_Limited_Record (Def_Id, Is_Limited_Record (T));
10272 if Has_Discrs
10273 and then not Is_Empty_Elmt_List (Elist)
10274 and then not For_Access
10275 then
10276 Create_Constrained_Components (Def_Id, Related_Nod, T, Elist);
10278 elsif not For_Access then
10279 Set_Cloned_Subtype (Def_Id, T);
10280 end if;
10281 end if;
10282 end Build_Discriminated_Subtype;
10284 ---------------------------
10285 -- Build_Itype_Reference --
10286 ---------------------------
10288 procedure Build_Itype_Reference
10289 (Ityp : Entity_Id;
10290 Nod : Node_Id)
10292 IR : constant Node_Id := Make_Itype_Reference (Sloc (Nod));
10293 begin
10295 -- Itype references are only created for use by the back-end
10297 if Inside_A_Generic then
10298 return;
10299 else
10300 Set_Itype (IR, Ityp);
10302 -- If Nod is a library unit entity, then Insert_After won't work,
10303 -- because Nod is not a member of any list. Therefore, we use
10304 -- Add_Global_Declaration in this case. This can happen if we have a
10305 -- build-in-place library function.
10307 if (Nkind (Nod) in N_Entity and then Is_Compilation_Unit (Nod))
10308 or else
10309 (Nkind (Nod) = N_Defining_Program_Unit_Name
10310 and then Is_Compilation_Unit (Defining_Identifier (Nod)))
10311 then
10312 Add_Global_Declaration (IR);
10313 else
10314 Insert_After (Nod, IR);
10315 end if;
10316 end if;
10317 end Build_Itype_Reference;
10319 ------------------------
10320 -- Build_Scalar_Bound --
10321 ------------------------
10323 function Build_Scalar_Bound
10324 (Bound : Node_Id;
10325 Par_T : Entity_Id;
10326 Der_T : Entity_Id) return Node_Id
10328 New_Bound : Entity_Id;
10330 begin
10331 -- Note: not clear why this is needed, how can the original bound
10332 -- be unanalyzed at this point? and if it is, what business do we
10333 -- have messing around with it? and why is the base type of the
10334 -- parent type the right type for the resolution. It probably is
10335 -- not. It is OK for the new bound we are creating, but not for
10336 -- the old one??? Still if it never happens, no problem.
10338 Analyze_And_Resolve (Bound, Base_Type (Par_T));
10340 if Nkind_In (Bound, N_Integer_Literal, N_Real_Literal) then
10341 New_Bound := New_Copy (Bound);
10342 Set_Etype (New_Bound, Der_T);
10343 Set_Analyzed (New_Bound);
10345 elsif Is_Entity_Name (Bound) then
10346 New_Bound := OK_Convert_To (Der_T, New_Copy (Bound));
10348 -- The following is almost certainly wrong. What business do we have
10349 -- relocating a node (Bound) that is presumably still attached to
10350 -- the tree elsewhere???
10352 else
10353 New_Bound := OK_Convert_To (Der_T, Relocate_Node (Bound));
10354 end if;
10356 Set_Etype (New_Bound, Der_T);
10357 return New_Bound;
10358 end Build_Scalar_Bound;
10360 --------------------------------
10361 -- Build_Underlying_Full_View --
10362 --------------------------------
10364 procedure Build_Underlying_Full_View
10365 (N : Node_Id;
10366 Typ : Entity_Id;
10367 Par : Entity_Id)
10369 Loc : constant Source_Ptr := Sloc (N);
10370 Subt : constant Entity_Id :=
10371 Make_Defining_Identifier
10372 (Loc, New_External_Name (Chars (Typ), 'S'));
10374 Constr : Node_Id;
10375 Indic : Node_Id;
10376 C : Node_Id;
10377 Id : Node_Id;
10379 procedure Set_Discriminant_Name (Id : Node_Id);
10380 -- If the derived type has discriminants, they may rename discriminants
10381 -- of the parent. When building the full view of the parent, we need to
10382 -- recover the names of the original discriminants if the constraint is
10383 -- given by named associations.
10385 ---------------------------
10386 -- Set_Discriminant_Name --
10387 ---------------------------
10389 procedure Set_Discriminant_Name (Id : Node_Id) is
10390 Disc : Entity_Id;
10392 begin
10393 Set_Original_Discriminant (Id, Empty);
10395 if Has_Discriminants (Typ) then
10396 Disc := First_Discriminant (Typ);
10397 while Present (Disc) loop
10398 if Chars (Disc) = Chars (Id)
10399 and then Present (Corresponding_Discriminant (Disc))
10400 then
10401 Set_Chars (Id, Chars (Corresponding_Discriminant (Disc)));
10402 end if;
10403 Next_Discriminant (Disc);
10404 end loop;
10405 end if;
10406 end Set_Discriminant_Name;
10408 -- Start of processing for Build_Underlying_Full_View
10410 begin
10411 if Nkind (N) = N_Full_Type_Declaration then
10412 Constr := Constraint (Subtype_Indication (Type_Definition (N)));
10414 elsif Nkind (N) = N_Subtype_Declaration then
10415 Constr := New_Copy_Tree (Constraint (Subtype_Indication (N)));
10417 elsif Nkind (N) = N_Component_Declaration then
10418 Constr :=
10419 New_Copy_Tree
10420 (Constraint (Subtype_Indication (Component_Definition (N))));
10422 else
10423 raise Program_Error;
10424 end if;
10426 C := First (Constraints (Constr));
10427 while Present (C) loop
10428 if Nkind (C) = N_Discriminant_Association then
10429 Id := First (Selector_Names (C));
10430 while Present (Id) loop
10431 Set_Discriminant_Name (Id);
10432 Next (Id);
10433 end loop;
10434 end if;
10436 Next (C);
10437 end loop;
10439 Indic :=
10440 Make_Subtype_Declaration (Loc,
10441 Defining_Identifier => Subt,
10442 Subtype_Indication =>
10443 Make_Subtype_Indication (Loc,
10444 Subtype_Mark => New_Occurrence_Of (Par, Loc),
10445 Constraint => New_Copy_Tree (Constr)));
10447 -- If this is a component subtype for an outer itype, it is not
10448 -- a list member, so simply set the parent link for analysis: if
10449 -- the enclosing type does not need to be in a declarative list,
10450 -- neither do the components.
10452 if Is_List_Member (N)
10453 and then Nkind (N) /= N_Component_Declaration
10454 then
10455 Insert_Before (N, Indic);
10456 else
10457 Set_Parent (Indic, Parent (N));
10458 end if;
10460 Analyze (Indic);
10461 Set_Underlying_Full_View (Typ, Full_View (Subt));
10462 Set_Is_Underlying_Full_View (Full_View (Subt));
10463 end Build_Underlying_Full_View;
10465 -------------------------------
10466 -- Check_Abstract_Overriding --
10467 -------------------------------
10469 procedure Check_Abstract_Overriding (T : Entity_Id) is
10470 Alias_Subp : Entity_Id;
10471 Elmt : Elmt_Id;
10472 Op_List : Elist_Id;
10473 Subp : Entity_Id;
10474 Type_Def : Node_Id;
10476 procedure Check_Pragma_Implemented (Subp : Entity_Id);
10477 -- Ada 2012 (AI05-0030): Subprogram Subp overrides an interface routine
10478 -- which has pragma Implemented already set. Check whether Subp's entity
10479 -- kind conforms to the implementation kind of the overridden routine.
10481 procedure Check_Pragma_Implemented
10482 (Subp : Entity_Id;
10483 Iface_Subp : Entity_Id);
10484 -- Ada 2012 (AI05-0030): Subprogram Subp overrides interface routine
10485 -- Iface_Subp and both entities have pragma Implemented already set on
10486 -- them. Check whether the two implementation kinds are conforming.
10488 procedure Inherit_Pragma_Implemented
10489 (Subp : Entity_Id;
10490 Iface_Subp : Entity_Id);
10491 -- Ada 2012 (AI05-0030): Interface primitive Subp overrides interface
10492 -- subprogram Iface_Subp which has been marked by pragma Implemented.
10493 -- Propagate the implementation kind of Iface_Subp to Subp.
10495 ------------------------------
10496 -- Check_Pragma_Implemented --
10497 ------------------------------
10499 procedure Check_Pragma_Implemented (Subp : Entity_Id) is
10500 Iface_Alias : constant Entity_Id := Interface_Alias (Subp);
10501 Impl_Kind : constant Name_Id := Implementation_Kind (Iface_Alias);
10502 Subp_Alias : constant Entity_Id := Alias (Subp);
10503 Contr_Typ : Entity_Id;
10504 Impl_Subp : Entity_Id;
10506 begin
10507 -- Subp must have an alias since it is a hidden entity used to link
10508 -- an interface subprogram to its overriding counterpart.
10510 pragma Assert (Present (Subp_Alias));
10512 -- Handle aliases to synchronized wrappers
10514 Impl_Subp := Subp_Alias;
10516 if Is_Primitive_Wrapper (Impl_Subp) then
10517 Impl_Subp := Wrapped_Entity (Impl_Subp);
10518 end if;
10520 -- Extract the type of the controlling formal
10522 Contr_Typ := Etype (First_Formal (Subp_Alias));
10524 if Is_Concurrent_Record_Type (Contr_Typ) then
10525 Contr_Typ := Corresponding_Concurrent_Type (Contr_Typ);
10526 end if;
10528 -- An interface subprogram whose implementation kind is By_Entry must
10529 -- be implemented by an entry.
10531 if Impl_Kind = Name_By_Entry
10532 and then Ekind (Impl_Subp) /= E_Entry
10533 then
10534 Error_Msg_Node_2 := Iface_Alias;
10535 Error_Msg_NE
10536 ("type & must implement abstract subprogram & with an entry",
10537 Subp_Alias, Contr_Typ);
10539 elsif Impl_Kind = Name_By_Protected_Procedure then
10541 -- An interface subprogram whose implementation kind is By_
10542 -- Protected_Procedure cannot be implemented by a primitive
10543 -- procedure of a task type.
10545 if Ekind (Contr_Typ) /= E_Protected_Type then
10546 Error_Msg_Node_2 := Contr_Typ;
10547 Error_Msg_NE
10548 ("interface subprogram & cannot be implemented by a " &
10549 "primitive procedure of task type &", Subp_Alias,
10550 Iface_Alias);
10552 -- An interface subprogram whose implementation kind is By_
10553 -- Protected_Procedure must be implemented by a procedure.
10555 elsif Ekind (Impl_Subp) /= E_Procedure then
10556 Error_Msg_Node_2 := Iface_Alias;
10557 Error_Msg_NE
10558 ("type & must implement abstract subprogram & with a " &
10559 "procedure", Subp_Alias, Contr_Typ);
10561 elsif Present (Get_Rep_Pragma (Impl_Subp, Name_Implemented))
10562 and then Implementation_Kind (Impl_Subp) /= Impl_Kind
10563 then
10564 Error_Msg_Name_1 := Impl_Kind;
10565 Error_Msg_N
10566 ("overriding operation& must have synchronization%",
10567 Subp_Alias);
10568 end if;
10570 -- If primitive has Optional synchronization, overriding operation
10571 -- must match if it has an explicit synchronization..
10573 elsif Present (Get_Rep_Pragma (Impl_Subp, Name_Implemented))
10574 and then Implementation_Kind (Impl_Subp) /= Impl_Kind
10575 then
10576 Error_Msg_Name_1 := Impl_Kind;
10577 Error_Msg_N
10578 ("overriding operation& must have syncrhonization%",
10579 Subp_Alias);
10580 end if;
10581 end Check_Pragma_Implemented;
10583 ------------------------------
10584 -- Check_Pragma_Implemented --
10585 ------------------------------
10587 procedure Check_Pragma_Implemented
10588 (Subp : Entity_Id;
10589 Iface_Subp : Entity_Id)
10591 Iface_Kind : constant Name_Id := Implementation_Kind (Iface_Subp);
10592 Subp_Kind : constant Name_Id := Implementation_Kind (Subp);
10594 begin
10595 -- Ada 2012 (AI05-0030): The implementation kinds of an overridden
10596 -- and overriding subprogram are different. In general this is an
10597 -- error except when the implementation kind of the overridden
10598 -- subprograms is By_Any or Optional.
10600 if Iface_Kind /= Subp_Kind
10601 and then Iface_Kind /= Name_By_Any
10602 and then Iface_Kind /= Name_Optional
10603 then
10604 if Iface_Kind = Name_By_Entry then
10605 Error_Msg_N
10606 ("incompatible implementation kind, overridden subprogram " &
10607 "is marked By_Entry", Subp);
10608 else
10609 Error_Msg_N
10610 ("incompatible implementation kind, overridden subprogram " &
10611 "is marked By_Protected_Procedure", Subp);
10612 end if;
10613 end if;
10614 end Check_Pragma_Implemented;
10616 --------------------------------
10617 -- Inherit_Pragma_Implemented --
10618 --------------------------------
10620 procedure Inherit_Pragma_Implemented
10621 (Subp : Entity_Id;
10622 Iface_Subp : Entity_Id)
10624 Iface_Kind : constant Name_Id := Implementation_Kind (Iface_Subp);
10625 Loc : constant Source_Ptr := Sloc (Subp);
10626 Impl_Prag : Node_Id;
10628 begin
10629 -- Since the implementation kind is stored as a representation item
10630 -- rather than a flag, create a pragma node.
10632 Impl_Prag :=
10633 Make_Pragma (Loc,
10634 Chars => Name_Implemented,
10635 Pragma_Argument_Associations => New_List (
10636 Make_Pragma_Argument_Association (Loc,
10637 Expression => New_Occurrence_Of (Subp, Loc)),
10639 Make_Pragma_Argument_Association (Loc,
10640 Expression => Make_Identifier (Loc, Iface_Kind))));
10642 -- The pragma doesn't need to be analyzed because it is internally
10643 -- built. It is safe to directly register it as a rep item since we
10644 -- are only interested in the characters of the implementation kind.
10646 Record_Rep_Item (Subp, Impl_Prag);
10647 end Inherit_Pragma_Implemented;
10649 -- Start of processing for Check_Abstract_Overriding
10651 begin
10652 Op_List := Primitive_Operations (T);
10654 -- Loop to check primitive operations
10656 Elmt := First_Elmt (Op_List);
10657 while Present (Elmt) loop
10658 Subp := Node (Elmt);
10659 Alias_Subp := Alias (Subp);
10661 -- Inherited subprograms are identified by the fact that they do not
10662 -- come from source, and the associated source location is the
10663 -- location of the first subtype of the derived type.
10665 -- Ada 2005 (AI-228): Apply the rules of RM-3.9.3(6/2) for
10666 -- subprograms that "require overriding".
10668 -- Special exception, do not complain about failure to override the
10669 -- stream routines _Input and _Output, as well as the primitive
10670 -- operations used in dispatching selects since we always provide
10671 -- automatic overridings for these subprograms.
10673 -- The partial view of T may have been a private extension, for
10674 -- which inherited functions dispatching on result are abstract.
10675 -- If the full view is a null extension, there is no need for
10676 -- overriding in Ada 2005, but wrappers need to be built for them
10677 -- (see exp_ch3, Build_Controlling_Function_Wrappers).
10679 if Is_Null_Extension (T)
10680 and then Has_Controlling_Result (Subp)
10681 and then Ada_Version >= Ada_2005
10682 and then Present (Alias_Subp)
10683 and then not Comes_From_Source (Subp)
10684 and then not Is_Abstract_Subprogram (Alias_Subp)
10685 and then not Is_Access_Type (Etype (Subp))
10686 then
10687 null;
10689 -- Ada 2005 (AI-251): Internal entities of interfaces need no
10690 -- processing because this check is done with the aliased
10691 -- entity
10693 elsif Present (Interface_Alias (Subp)) then
10694 null;
10696 elsif (Is_Abstract_Subprogram (Subp)
10697 or else Requires_Overriding (Subp)
10698 or else
10699 (Has_Controlling_Result (Subp)
10700 and then Present (Alias_Subp)
10701 and then not Comes_From_Source (Subp)
10702 and then Sloc (Subp) = Sloc (First_Subtype (T))))
10703 and then not Is_TSS (Subp, TSS_Stream_Input)
10704 and then not Is_TSS (Subp, TSS_Stream_Output)
10705 and then not Is_Abstract_Type (T)
10706 and then not Is_Predefined_Interface_Primitive (Subp)
10708 -- Ada 2005 (AI-251): Do not consider hidden entities associated
10709 -- with abstract interface types because the check will be done
10710 -- with the aliased entity (otherwise we generate a duplicated
10711 -- error message).
10713 and then not Present (Interface_Alias (Subp))
10714 then
10715 if Present (Alias_Subp) then
10717 -- Only perform the check for a derived subprogram when the
10718 -- type has an explicit record extension. This avoids incorrect
10719 -- flagging of abstract subprograms for the case of a type
10720 -- without an extension that is derived from a formal type
10721 -- with a tagged actual (can occur within a private part).
10723 -- Ada 2005 (AI-391): In the case of an inherited function with
10724 -- a controlling result of the type, the rule does not apply if
10725 -- the type is a null extension (unless the parent function
10726 -- itself is abstract, in which case the function must still be
10727 -- be overridden). The expander will generate an overriding
10728 -- wrapper function calling the parent subprogram (see
10729 -- Exp_Ch3.Make_Controlling_Wrapper_Functions).
10731 Type_Def := Type_Definition (Parent (T));
10733 if Nkind (Type_Def) = N_Derived_Type_Definition
10734 and then Present (Record_Extension_Part (Type_Def))
10735 and then
10736 (Ada_Version < Ada_2005
10737 or else not Is_Null_Extension (T)
10738 or else Ekind (Subp) = E_Procedure
10739 or else not Has_Controlling_Result (Subp)
10740 or else Is_Abstract_Subprogram (Alias_Subp)
10741 or else Requires_Overriding (Subp)
10742 or else Is_Access_Type (Etype (Subp)))
10743 then
10744 -- Avoid reporting error in case of abstract predefined
10745 -- primitive inherited from interface type because the
10746 -- body of internally generated predefined primitives
10747 -- of tagged types are generated later by Freeze_Type
10749 if Is_Interface (Root_Type (T))
10750 and then Is_Abstract_Subprogram (Subp)
10751 and then Is_Predefined_Dispatching_Operation (Subp)
10752 and then not Comes_From_Source (Ultimate_Alias (Subp))
10753 then
10754 null;
10756 -- A null extension is not obliged to override an inherited
10757 -- procedure subject to pragma Extensions_Visible with value
10758 -- False and at least one controlling OUT parameter
10759 -- (SPARK RM 6.1.7(6)).
10761 elsif Is_Null_Extension (T)
10762 and then Is_EVF_Procedure (Subp)
10763 then
10764 null;
10766 else
10767 Error_Msg_NE
10768 ("type must be declared abstract or & overridden",
10769 T, Subp);
10771 -- Traverse the whole chain of aliased subprograms to
10772 -- complete the error notification. This is especially
10773 -- useful for traceability of the chain of entities when
10774 -- the subprogram corresponds with an interface
10775 -- subprogram (which may be defined in another package).
10777 if Present (Alias_Subp) then
10778 declare
10779 E : Entity_Id;
10781 begin
10782 E := Subp;
10783 while Present (Alias (E)) loop
10785 -- Avoid reporting redundant errors on entities
10786 -- inherited from interfaces
10788 if Sloc (E) /= Sloc (T) then
10789 Error_Msg_Sloc := Sloc (E);
10790 Error_Msg_NE
10791 ("\& has been inherited #", T, Subp);
10792 end if;
10794 E := Alias (E);
10795 end loop;
10797 Error_Msg_Sloc := Sloc (E);
10799 -- AI05-0068: report if there is an overriding
10800 -- non-abstract subprogram that is invisible.
10802 if Is_Hidden (E)
10803 and then not Is_Abstract_Subprogram (E)
10804 then
10805 Error_Msg_NE
10806 ("\& subprogram# is not visible",
10807 T, Subp);
10809 -- Clarify the case where a non-null extension must
10810 -- override inherited procedure subject to pragma
10811 -- Extensions_Visible with value False and at least
10812 -- one controlling OUT param.
10814 elsif Is_EVF_Procedure (E) then
10815 Error_Msg_NE
10816 ("\& # is subject to Extensions_Visible False",
10817 T, Subp);
10819 else
10820 Error_Msg_NE
10821 ("\& has been inherited from subprogram #",
10822 T, Subp);
10823 end if;
10824 end;
10825 end if;
10826 end if;
10828 -- Ada 2005 (AI-345): Protected or task type implementing
10829 -- abstract interfaces.
10831 elsif Is_Concurrent_Record_Type (T)
10832 and then Present (Interfaces (T))
10833 then
10834 -- There is no need to check here RM 9.4(11.9/3) since we
10835 -- are processing the corresponding record type and the
10836 -- mode of the overriding subprograms was verified by
10837 -- Check_Conformance when the corresponding concurrent
10838 -- type declaration was analyzed.
10840 Error_Msg_NE
10841 ("interface subprogram & must be overridden", T, Subp);
10843 -- Examine primitive operations of synchronized type to find
10844 -- homonyms that have the wrong profile.
10846 declare
10847 Prim : Entity_Id;
10849 begin
10850 Prim := First_Entity (Corresponding_Concurrent_Type (T));
10851 while Present (Prim) loop
10852 if Chars (Prim) = Chars (Subp) then
10853 Error_Msg_NE
10854 ("profile is not type conformant with prefixed "
10855 & "view profile of inherited operation&",
10856 Prim, Subp);
10857 end if;
10859 Next_Entity (Prim);
10860 end loop;
10861 end;
10862 end if;
10864 else
10865 Error_Msg_Node_2 := T;
10866 Error_Msg_N
10867 ("abstract subprogram& not allowed for type&", Subp);
10869 -- Also post unconditional warning on the type (unconditional
10870 -- so that if there are more than one of these cases, we get
10871 -- them all, and not just the first one).
10873 Error_Msg_Node_2 := Subp;
10874 Error_Msg_N ("nonabstract type& has abstract subprogram&!", T);
10875 end if;
10877 -- A subprogram subject to pragma Extensions_Visible with value
10878 -- "True" cannot override a subprogram subject to the same pragma
10879 -- with value "False" (SPARK RM 6.1.7(5)).
10881 elsif Extensions_Visible_Status (Subp) = Extensions_Visible_True
10882 and then Present (Overridden_Operation (Subp))
10883 and then Extensions_Visible_Status (Overridden_Operation (Subp)) =
10884 Extensions_Visible_False
10885 then
10886 Error_Msg_Sloc := Sloc (Overridden_Operation (Subp));
10887 Error_Msg_N
10888 ("subprogram & with Extensions_Visible True cannot override "
10889 & "subprogram # with Extensions_Visible False", Subp);
10890 end if;
10892 -- Ada 2012 (AI05-0030): Perform checks related to pragma Implemented
10894 -- Subp is an expander-generated procedure which maps an interface
10895 -- alias to a protected wrapper. The interface alias is flagged by
10896 -- pragma Implemented. Ensure that Subp is a procedure when the
10897 -- implementation kind is By_Protected_Procedure or an entry when
10898 -- By_Entry.
10900 if Ada_Version >= Ada_2012
10901 and then Is_Hidden (Subp)
10902 and then Present (Interface_Alias (Subp))
10903 and then Has_Rep_Pragma (Interface_Alias (Subp), Name_Implemented)
10904 then
10905 Check_Pragma_Implemented (Subp);
10906 end if;
10908 -- Subp is an interface primitive which overrides another interface
10909 -- primitive marked with pragma Implemented.
10911 if Ada_Version >= Ada_2012
10912 and then Present (Overridden_Operation (Subp))
10913 and then Has_Rep_Pragma
10914 (Overridden_Operation (Subp), Name_Implemented)
10915 then
10916 -- If the overriding routine is also marked by Implemented, check
10917 -- that the two implementation kinds are conforming.
10919 if Has_Rep_Pragma (Subp, Name_Implemented) then
10920 Check_Pragma_Implemented
10921 (Subp => Subp,
10922 Iface_Subp => Overridden_Operation (Subp));
10924 -- Otherwise the overriding routine inherits the implementation
10925 -- kind from the overridden subprogram.
10927 else
10928 Inherit_Pragma_Implemented
10929 (Subp => Subp,
10930 Iface_Subp => Overridden_Operation (Subp));
10931 end if;
10932 end if;
10934 -- If the operation is a wrapper for a synchronized primitive, it
10935 -- may be called indirectly through a dispatching select. We assume
10936 -- that it will be referenced elsewhere indirectly, and suppress
10937 -- warnings about an unused entity.
10939 if Is_Primitive_Wrapper (Subp)
10940 and then Present (Wrapped_Entity (Subp))
10941 then
10942 Set_Referenced (Wrapped_Entity (Subp));
10943 end if;
10945 Next_Elmt (Elmt);
10946 end loop;
10947 end Check_Abstract_Overriding;
10949 ------------------------------------------------
10950 -- Check_Access_Discriminant_Requires_Limited --
10951 ------------------------------------------------
10953 procedure Check_Access_Discriminant_Requires_Limited
10954 (D : Node_Id;
10955 Loc : Node_Id)
10957 begin
10958 -- A discriminant_specification for an access discriminant shall appear
10959 -- only in the declaration for a task or protected type, or for a type
10960 -- with the reserved word 'limited' in its definition or in one of its
10961 -- ancestors (RM 3.7(10)).
10963 -- AI-0063: The proper condition is that type must be immutably limited,
10964 -- or else be a partial view.
10966 if Nkind (Discriminant_Type (D)) = N_Access_Definition then
10967 if Is_Limited_View (Current_Scope)
10968 or else
10969 (Nkind (Parent (Current_Scope)) = N_Private_Type_Declaration
10970 and then Limited_Present (Parent (Current_Scope)))
10971 then
10972 null;
10974 else
10975 Error_Msg_N
10976 ("access discriminants allowed only for limited types", Loc);
10977 end if;
10978 end if;
10979 end Check_Access_Discriminant_Requires_Limited;
10981 -----------------------------------
10982 -- Check_Aliased_Component_Types --
10983 -----------------------------------
10985 procedure Check_Aliased_Component_Types (T : Entity_Id) is
10986 C : Entity_Id;
10988 begin
10989 -- ??? Also need to check components of record extensions, but not
10990 -- components of protected types (which are always limited).
10992 -- Ada 2005: AI-363 relaxes this rule, to allow heap objects of such
10993 -- types to be unconstrained. This is safe because it is illegal to
10994 -- create access subtypes to such types with explicit discriminant
10995 -- constraints.
10997 if not Is_Limited_Type (T) then
10998 if Ekind (T) = E_Record_Type then
10999 C := First_Component (T);
11000 while Present (C) loop
11001 if Is_Aliased (C)
11002 and then Has_Discriminants (Etype (C))
11003 and then not Is_Constrained (Etype (C))
11004 and then not In_Instance_Body
11005 and then Ada_Version < Ada_2005
11006 then
11007 Error_Msg_N
11008 ("aliased component must be constrained (RM 3.6(11))",
11010 end if;
11012 Next_Component (C);
11013 end loop;
11015 elsif Ekind (T) = E_Array_Type then
11016 if Has_Aliased_Components (T)
11017 and then Has_Discriminants (Component_Type (T))
11018 and then not Is_Constrained (Component_Type (T))
11019 and then not In_Instance_Body
11020 and then Ada_Version < Ada_2005
11021 then
11022 Error_Msg_N
11023 ("aliased component type must be constrained (RM 3.6(11))",
11025 end if;
11026 end if;
11027 end if;
11028 end Check_Aliased_Component_Types;
11030 ---------------------------------------
11031 -- Check_Anonymous_Access_Components --
11032 ---------------------------------------
11034 procedure Check_Anonymous_Access_Components
11035 (Typ_Decl : Node_Id;
11036 Typ : Entity_Id;
11037 Prev : Entity_Id;
11038 Comp_List : Node_Id)
11040 Loc : constant Source_Ptr := Sloc (Typ_Decl);
11041 Anon_Access : Entity_Id;
11042 Acc_Def : Node_Id;
11043 Comp : Node_Id;
11044 Comp_Def : Node_Id;
11045 Decl : Node_Id;
11046 Type_Def : Node_Id;
11048 procedure Build_Incomplete_Type_Declaration;
11049 -- If the record type contains components that include an access to the
11050 -- current record, then create an incomplete type declaration for the
11051 -- record, to be used as the designated type of the anonymous access.
11052 -- This is done only once, and only if there is no previous partial
11053 -- view of the type.
11055 function Designates_T (Subt : Node_Id) return Boolean;
11056 -- Check whether a node designates the enclosing record type, or 'Class
11057 -- of that type
11059 function Mentions_T (Acc_Def : Node_Id) return Boolean;
11060 -- Check whether an access definition includes a reference to
11061 -- the enclosing record type. The reference can be a subtype mark
11062 -- in the access definition itself, a 'Class attribute reference, or
11063 -- recursively a reference appearing in a parameter specification
11064 -- or result definition of an access_to_subprogram definition.
11066 --------------------------------------
11067 -- Build_Incomplete_Type_Declaration --
11068 --------------------------------------
11070 procedure Build_Incomplete_Type_Declaration is
11071 Decl : Node_Id;
11072 Inc_T : Entity_Id;
11073 H : Entity_Id;
11075 -- Is_Tagged indicates whether the type is tagged. It is tagged if
11076 -- it's "is new ... with record" or else "is tagged record ...".
11078 Is_Tagged : constant Boolean :=
11079 (Nkind (Type_Definition (Typ_Decl)) = N_Derived_Type_Definition
11080 and then
11081 Present (Record_Extension_Part (Type_Definition (Typ_Decl))))
11082 or else
11083 (Nkind (Type_Definition (Typ_Decl)) = N_Record_Definition
11084 and then Tagged_Present (Type_Definition (Typ_Decl)));
11086 begin
11087 -- If there is a previous partial view, no need to create a new one
11088 -- If the partial view, given by Prev, is incomplete, If Prev is
11089 -- a private declaration, full declaration is flagged accordingly.
11091 if Prev /= Typ then
11092 if Is_Tagged then
11093 Make_Class_Wide_Type (Prev);
11094 Set_Class_Wide_Type (Typ, Class_Wide_Type (Prev));
11095 Set_Etype (Class_Wide_Type (Typ), Typ);
11096 end if;
11098 return;
11100 elsif Has_Private_Declaration (Typ) then
11102 -- If we refer to T'Class inside T, and T is the completion of a
11103 -- private type, then make sure the class-wide type exists.
11105 if Is_Tagged then
11106 Make_Class_Wide_Type (Typ);
11107 end if;
11109 return;
11111 -- If there was a previous anonymous access type, the incomplete
11112 -- type declaration will have been created already.
11114 elsif Present (Current_Entity (Typ))
11115 and then Ekind (Current_Entity (Typ)) = E_Incomplete_Type
11116 and then Full_View (Current_Entity (Typ)) = Typ
11117 then
11118 if Is_Tagged
11119 and then Comes_From_Source (Current_Entity (Typ))
11120 and then not Is_Tagged_Type (Current_Entity (Typ))
11121 then
11122 Make_Class_Wide_Type (Typ);
11123 Error_Msg_N
11124 ("incomplete view of tagged type should be declared tagged??",
11125 Parent (Current_Entity (Typ)));
11126 end if;
11127 return;
11129 else
11130 Inc_T := Make_Defining_Identifier (Loc, Chars (Typ));
11131 Decl := Make_Incomplete_Type_Declaration (Loc, Inc_T);
11133 -- Type has already been inserted into the current scope. Remove
11134 -- it, and add incomplete declaration for type, so that subsequent
11135 -- anonymous access types can use it. The entity is unchained from
11136 -- the homonym list and from immediate visibility. After analysis,
11137 -- the entity in the incomplete declaration becomes immediately
11138 -- visible in the record declaration that follows.
11140 H := Current_Entity (Typ);
11142 if H = Typ then
11143 Set_Name_Entity_Id (Chars (Typ), Homonym (Typ));
11144 else
11145 while Present (H)
11146 and then Homonym (H) /= Typ
11147 loop
11148 H := Homonym (Typ);
11149 end loop;
11151 Set_Homonym (H, Homonym (Typ));
11152 end if;
11154 Insert_Before (Typ_Decl, Decl);
11155 Analyze (Decl);
11156 Set_Full_View (Inc_T, Typ);
11158 if Is_Tagged then
11160 -- Create a common class-wide type for both views, and set the
11161 -- Etype of the class-wide type to the full view.
11163 Make_Class_Wide_Type (Inc_T);
11164 Set_Class_Wide_Type (Typ, Class_Wide_Type (Inc_T));
11165 Set_Etype (Class_Wide_Type (Typ), Typ);
11166 end if;
11167 end if;
11168 end Build_Incomplete_Type_Declaration;
11170 ------------------
11171 -- Designates_T --
11172 ------------------
11174 function Designates_T (Subt : Node_Id) return Boolean is
11175 Type_Id : constant Name_Id := Chars (Typ);
11177 function Names_T (Nam : Node_Id) return Boolean;
11178 -- The record type has not been introduced in the current scope
11179 -- yet, so we must examine the name of the type itself, either
11180 -- an identifier T, or an expanded name of the form P.T, where
11181 -- P denotes the current scope.
11183 -------------
11184 -- Names_T --
11185 -------------
11187 function Names_T (Nam : Node_Id) return Boolean is
11188 begin
11189 if Nkind (Nam) = N_Identifier then
11190 return Chars (Nam) = Type_Id;
11192 elsif Nkind (Nam) = N_Selected_Component then
11193 if Chars (Selector_Name (Nam)) = Type_Id then
11194 if Nkind (Prefix (Nam)) = N_Identifier then
11195 return Chars (Prefix (Nam)) = Chars (Current_Scope);
11197 elsif Nkind (Prefix (Nam)) = N_Selected_Component then
11198 return Chars (Selector_Name (Prefix (Nam))) =
11199 Chars (Current_Scope);
11200 else
11201 return False;
11202 end if;
11204 else
11205 return False;
11206 end if;
11208 else
11209 return False;
11210 end if;
11211 end Names_T;
11213 -- Start of processing for Designates_T
11215 begin
11216 if Nkind (Subt) = N_Identifier then
11217 return Chars (Subt) = Type_Id;
11219 -- Reference can be through an expanded name which has not been
11220 -- analyzed yet, and which designates enclosing scopes.
11222 elsif Nkind (Subt) = N_Selected_Component then
11223 if Names_T (Subt) then
11224 return True;
11226 -- Otherwise it must denote an entity that is already visible.
11227 -- The access definition may name a subtype of the enclosing
11228 -- type, if there is a previous incomplete declaration for it.
11230 else
11231 Find_Selected_Component (Subt);
11232 return
11233 Is_Entity_Name (Subt)
11234 and then Scope (Entity (Subt)) = Current_Scope
11235 and then
11236 (Chars (Base_Type (Entity (Subt))) = Type_Id
11237 or else
11238 (Is_Class_Wide_Type (Entity (Subt))
11239 and then
11240 Chars (Etype (Base_Type (Entity (Subt)))) =
11241 Type_Id));
11242 end if;
11244 -- A reference to the current type may appear as the prefix of
11245 -- a 'Class attribute.
11247 elsif Nkind (Subt) = N_Attribute_Reference
11248 and then Attribute_Name (Subt) = Name_Class
11249 then
11250 return Names_T (Prefix (Subt));
11252 else
11253 return False;
11254 end if;
11255 end Designates_T;
11257 ----------------
11258 -- Mentions_T --
11259 ----------------
11261 function Mentions_T (Acc_Def : Node_Id) return Boolean is
11262 Param_Spec : Node_Id;
11264 Acc_Subprg : constant Node_Id :=
11265 Access_To_Subprogram_Definition (Acc_Def);
11267 begin
11268 if No (Acc_Subprg) then
11269 return Designates_T (Subtype_Mark (Acc_Def));
11270 end if;
11272 -- Component is an access_to_subprogram: examine its formals,
11273 -- and result definition in the case of an access_to_function.
11275 Param_Spec := First (Parameter_Specifications (Acc_Subprg));
11276 while Present (Param_Spec) loop
11277 if Nkind (Parameter_Type (Param_Spec)) = N_Access_Definition
11278 and then Mentions_T (Parameter_Type (Param_Spec))
11279 then
11280 return True;
11282 elsif Designates_T (Parameter_Type (Param_Spec)) then
11283 return True;
11284 end if;
11286 Next (Param_Spec);
11287 end loop;
11289 if Nkind (Acc_Subprg) = N_Access_Function_Definition then
11290 if Nkind (Result_Definition (Acc_Subprg)) =
11291 N_Access_Definition
11292 then
11293 return Mentions_T (Result_Definition (Acc_Subprg));
11294 else
11295 return Designates_T (Result_Definition (Acc_Subprg));
11296 end if;
11297 end if;
11299 return False;
11300 end Mentions_T;
11302 -- Start of processing for Check_Anonymous_Access_Components
11304 begin
11305 if No (Comp_List) then
11306 return;
11307 end if;
11309 Comp := First (Component_Items (Comp_List));
11310 while Present (Comp) loop
11311 if Nkind (Comp) = N_Component_Declaration
11312 and then Present
11313 (Access_Definition (Component_Definition (Comp)))
11314 and then
11315 Mentions_T (Access_Definition (Component_Definition (Comp)))
11316 then
11317 Comp_Def := Component_Definition (Comp);
11318 Acc_Def :=
11319 Access_To_Subprogram_Definition (Access_Definition (Comp_Def));
11321 Build_Incomplete_Type_Declaration;
11322 Anon_Access := Make_Temporary (Loc, 'S');
11324 -- Create a declaration for the anonymous access type: either
11325 -- an access_to_object or an access_to_subprogram.
11327 if Present (Acc_Def) then
11328 if Nkind (Acc_Def) = N_Access_Function_Definition then
11329 Type_Def :=
11330 Make_Access_Function_Definition (Loc,
11331 Parameter_Specifications =>
11332 Parameter_Specifications (Acc_Def),
11333 Result_Definition => Result_Definition (Acc_Def));
11334 else
11335 Type_Def :=
11336 Make_Access_Procedure_Definition (Loc,
11337 Parameter_Specifications =>
11338 Parameter_Specifications (Acc_Def));
11339 end if;
11341 else
11342 Type_Def :=
11343 Make_Access_To_Object_Definition (Loc,
11344 Subtype_Indication =>
11345 Relocate_Node
11346 (Subtype_Mark (Access_Definition (Comp_Def))));
11348 Set_Constant_Present
11349 (Type_Def, Constant_Present (Access_Definition (Comp_Def)));
11350 Set_All_Present
11351 (Type_Def, All_Present (Access_Definition (Comp_Def)));
11352 end if;
11354 Set_Null_Exclusion_Present
11355 (Type_Def,
11356 Null_Exclusion_Present (Access_Definition (Comp_Def)));
11358 Decl :=
11359 Make_Full_Type_Declaration (Loc,
11360 Defining_Identifier => Anon_Access,
11361 Type_Definition => Type_Def);
11363 Insert_Before (Typ_Decl, Decl);
11364 Analyze (Decl);
11366 -- If an access to subprogram, create the extra formals
11368 if Present (Acc_Def) then
11369 Create_Extra_Formals (Designated_Type (Anon_Access));
11371 -- If an access to object, preserve entity of designated type,
11372 -- for ASIS use, before rewriting the component definition.
11374 else
11375 declare
11376 Desig : Entity_Id;
11378 begin
11379 Desig := Entity (Subtype_Indication (Type_Def));
11381 -- If the access definition is to the current record,
11382 -- the visible entity at this point is an incomplete
11383 -- type. Retrieve the full view to simplify ASIS queries
11385 if Ekind (Desig) = E_Incomplete_Type then
11386 Desig := Full_View (Desig);
11387 end if;
11389 Set_Entity
11390 (Subtype_Mark (Access_Definition (Comp_Def)), Desig);
11391 end;
11392 end if;
11394 Rewrite (Comp_Def,
11395 Make_Component_Definition (Loc,
11396 Subtype_Indication =>
11397 New_Occurrence_Of (Anon_Access, Loc)));
11399 if Ekind (Designated_Type (Anon_Access)) = E_Subprogram_Type then
11400 Set_Ekind (Anon_Access, E_Anonymous_Access_Subprogram_Type);
11401 else
11402 Set_Ekind (Anon_Access, E_Anonymous_Access_Type);
11403 end if;
11405 Set_Is_Local_Anonymous_Access (Anon_Access);
11406 end if;
11408 Next (Comp);
11409 end loop;
11411 if Present (Variant_Part (Comp_List)) then
11412 declare
11413 V : Node_Id;
11414 begin
11415 V := First_Non_Pragma (Variants (Variant_Part (Comp_List)));
11416 while Present (V) loop
11417 Check_Anonymous_Access_Components
11418 (Typ_Decl, Typ, Prev, Component_List (V));
11419 Next_Non_Pragma (V);
11420 end loop;
11421 end;
11422 end if;
11423 end Check_Anonymous_Access_Components;
11425 ----------------------
11426 -- Check_Completion --
11427 ----------------------
11429 procedure Check_Completion (Body_Id : Node_Id := Empty) is
11430 E : Entity_Id;
11432 procedure Post_Error;
11433 -- Post error message for lack of completion for entity E
11435 ----------------
11436 -- Post_Error --
11437 ----------------
11439 procedure Post_Error is
11440 procedure Missing_Body;
11441 -- Output missing body message
11443 ------------------
11444 -- Missing_Body --
11445 ------------------
11447 procedure Missing_Body is
11448 begin
11449 -- Spec is in same unit, so we can post on spec
11451 if In_Same_Source_Unit (Body_Id, E) then
11452 Error_Msg_N ("missing body for &", E);
11454 -- Spec is in a separate unit, so we have to post on the body
11456 else
11457 Error_Msg_NE ("missing body for & declared#!", Body_Id, E);
11458 end if;
11459 end Missing_Body;
11461 -- Start of processing for Post_Error
11463 begin
11464 if not Comes_From_Source (E) then
11465 if Ekind_In (E, E_Task_Type, E_Protected_Type) then
11467 -- It may be an anonymous protected type created for a
11468 -- single variable. Post error on variable, if present.
11470 declare
11471 Var : Entity_Id;
11473 begin
11474 Var := First_Entity (Current_Scope);
11475 while Present (Var) loop
11476 exit when Etype (Var) = E
11477 and then Comes_From_Source (Var);
11479 Next_Entity (Var);
11480 end loop;
11482 if Present (Var) then
11483 E := Var;
11484 end if;
11485 end;
11486 end if;
11487 end if;
11489 -- If a generated entity has no completion, then either previous
11490 -- semantic errors have disabled the expansion phase, or else we had
11491 -- missing subunits, or else we are compiling without expansion,
11492 -- or else something is very wrong.
11494 if not Comes_From_Source (E) then
11495 pragma Assert
11496 (Serious_Errors_Detected > 0
11497 or else Configurable_Run_Time_Violations > 0
11498 or else Subunits_Missing
11499 or else not Expander_Active);
11500 return;
11502 -- Here for source entity
11504 else
11505 -- Here if no body to post the error message, so we post the error
11506 -- on the declaration that has no completion. This is not really
11507 -- the right place to post it, think about this later ???
11509 if No (Body_Id) then
11510 if Is_Type (E) then
11511 Error_Msg_NE
11512 ("missing full declaration for }", Parent (E), E);
11513 else
11514 Error_Msg_NE ("missing body for &", Parent (E), E);
11515 end if;
11517 -- Package body has no completion for a declaration that appears
11518 -- in the corresponding spec. Post error on the body, with a
11519 -- reference to the non-completed declaration.
11521 else
11522 Error_Msg_Sloc := Sloc (E);
11524 if Is_Type (E) then
11525 Error_Msg_NE ("missing full declaration for }!", Body_Id, E);
11527 elsif Is_Overloadable (E)
11528 and then Current_Entity_In_Scope (E) /= E
11529 then
11530 -- It may be that the completion is mistyped and appears as
11531 -- a distinct overloading of the entity.
11533 declare
11534 Candidate : constant Entity_Id :=
11535 Current_Entity_In_Scope (E);
11536 Decl : constant Node_Id :=
11537 Unit_Declaration_Node (Candidate);
11539 begin
11540 if Is_Overloadable (Candidate)
11541 and then Ekind (Candidate) = Ekind (E)
11542 and then Nkind (Decl) = N_Subprogram_Body
11543 and then Acts_As_Spec (Decl)
11544 then
11545 Check_Type_Conformant (Candidate, E);
11547 else
11548 Missing_Body;
11549 end if;
11550 end;
11552 else
11553 Missing_Body;
11554 end if;
11555 end if;
11556 end if;
11557 end Post_Error;
11559 -- Local variables
11561 Pack_Id : constant Entity_Id := Current_Scope;
11563 -- Start of processing for Check_Completion
11565 begin
11566 E := First_Entity (Pack_Id);
11567 while Present (E) loop
11568 if Is_Intrinsic_Subprogram (E) then
11569 null;
11571 -- The following situation requires special handling: a child unit
11572 -- that appears in the context clause of the body of its parent:
11574 -- procedure Parent.Child (...);
11576 -- with Parent.Child;
11577 -- package body Parent is
11579 -- Here Parent.Child appears as a local entity, but should not be
11580 -- flagged as requiring completion, because it is a compilation
11581 -- unit.
11583 -- Ignore missing completion for a subprogram that does not come from
11584 -- source (including the _Call primitive operation of RAS types,
11585 -- which has to have the flag Comes_From_Source for other purposes):
11586 -- we assume that the expander will provide the missing completion.
11587 -- In case of previous errors, other expansion actions that provide
11588 -- bodies for null procedures with not be invoked, so inhibit message
11589 -- in those cases.
11591 -- Note that E_Operator is not in the list that follows, because
11592 -- this kind is reserved for predefined operators, that are
11593 -- intrinsic and do not need completion.
11595 elsif Ekind_In (E, E_Function,
11596 E_Procedure,
11597 E_Generic_Function,
11598 E_Generic_Procedure)
11599 then
11600 if Has_Completion (E) then
11601 null;
11603 elsif Is_Subprogram (E) and then Is_Abstract_Subprogram (E) then
11604 null;
11606 elsif Is_Subprogram (E)
11607 and then (not Comes_From_Source (E)
11608 or else Chars (E) = Name_uCall)
11609 then
11610 null;
11612 elsif
11613 Nkind (Parent (Unit_Declaration_Node (E))) = N_Compilation_Unit
11614 then
11615 null;
11617 elsif Nkind (Parent (E)) = N_Procedure_Specification
11618 and then Null_Present (Parent (E))
11619 and then Serious_Errors_Detected > 0
11620 then
11621 null;
11623 else
11624 Post_Error;
11625 end if;
11627 elsif Is_Entry (E) then
11628 if not Has_Completion (E) and then
11629 (Ekind (Scope (E)) = E_Protected_Object
11630 or else Ekind (Scope (E)) = E_Protected_Type)
11631 then
11632 Post_Error;
11633 end if;
11635 elsif Is_Package_Or_Generic_Package (E) then
11636 if Unit_Requires_Body (E) then
11637 if not Has_Completion (E)
11638 and then Nkind (Parent (Unit_Declaration_Node (E))) /=
11639 N_Compilation_Unit
11640 then
11641 Post_Error;
11642 end if;
11644 elsif not Is_Child_Unit (E) then
11645 May_Need_Implicit_Body (E);
11646 end if;
11648 -- A formal incomplete type (Ada 2012) does not require a completion;
11649 -- other incomplete type declarations do.
11651 elsif Ekind (E) = E_Incomplete_Type
11652 and then No (Underlying_Type (E))
11653 and then not Is_Generic_Type (E)
11654 then
11655 Post_Error;
11657 elsif Ekind_In (E, E_Task_Type, E_Protected_Type)
11658 and then not Has_Completion (E)
11659 then
11660 Post_Error;
11662 -- A single task declared in the current scope is a constant, verify
11663 -- that the body of its anonymous type is in the same scope. If the
11664 -- task is defined elsewhere, this may be a renaming declaration for
11665 -- which no completion is needed.
11667 elsif Ekind (E) = E_Constant
11668 and then Ekind (Etype (E)) = E_Task_Type
11669 and then not Has_Completion (Etype (E))
11670 and then Scope (Etype (E)) = Current_Scope
11671 then
11672 Post_Error;
11674 elsif Ekind (E) = E_Protected_Object
11675 and then not Has_Completion (Etype (E))
11676 then
11677 Post_Error;
11679 elsif Ekind (E) = E_Record_Type then
11680 if Is_Tagged_Type (E) then
11681 Check_Abstract_Overriding (E);
11682 Check_Conventions (E);
11683 end if;
11685 Check_Aliased_Component_Types (E);
11687 elsif Ekind (E) = E_Array_Type then
11688 Check_Aliased_Component_Types (E);
11690 end if;
11692 Next_Entity (E);
11693 end loop;
11694 end Check_Completion;
11696 ------------------------------------
11697 -- Check_CPP_Type_Has_No_Defaults --
11698 ------------------------------------
11700 procedure Check_CPP_Type_Has_No_Defaults (T : Entity_Id) is
11701 Tdef : constant Node_Id := Type_Definition (Declaration_Node (T));
11702 Clist : Node_Id;
11703 Comp : Node_Id;
11705 begin
11706 -- Obtain the component list
11708 if Nkind (Tdef) = N_Record_Definition then
11709 Clist := Component_List (Tdef);
11710 else pragma Assert (Nkind (Tdef) = N_Derived_Type_Definition);
11711 Clist := Component_List (Record_Extension_Part (Tdef));
11712 end if;
11714 -- Check all components to ensure no default expressions
11716 if Present (Clist) then
11717 Comp := First (Component_Items (Clist));
11718 while Present (Comp) loop
11719 if Present (Expression (Comp)) then
11720 Error_Msg_N
11721 ("component of imported 'C'P'P type cannot have "
11722 & "default expression", Expression (Comp));
11723 end if;
11725 Next (Comp);
11726 end loop;
11727 end if;
11728 end Check_CPP_Type_Has_No_Defaults;
11730 ----------------------------
11731 -- Check_Delta_Expression --
11732 ----------------------------
11734 procedure Check_Delta_Expression (E : Node_Id) is
11735 begin
11736 if not (Is_Real_Type (Etype (E))) then
11737 Wrong_Type (E, Any_Real);
11739 elsif not Is_OK_Static_Expression (E) then
11740 Flag_Non_Static_Expr
11741 ("non-static expression used for delta value!", E);
11743 elsif not UR_Is_Positive (Expr_Value_R (E)) then
11744 Error_Msg_N ("delta expression must be positive", E);
11746 else
11747 return;
11748 end if;
11750 -- If any of above errors occurred, then replace the incorrect
11751 -- expression by the real 0.1, which should prevent further errors.
11753 Rewrite (E,
11754 Make_Real_Literal (Sloc (E), Ureal_Tenth));
11755 Analyze_And_Resolve (E, Standard_Float);
11756 end Check_Delta_Expression;
11758 -----------------------------
11759 -- Check_Digits_Expression --
11760 -----------------------------
11762 procedure Check_Digits_Expression (E : Node_Id) is
11763 begin
11764 if not (Is_Integer_Type (Etype (E))) then
11765 Wrong_Type (E, Any_Integer);
11767 elsif not Is_OK_Static_Expression (E) then
11768 Flag_Non_Static_Expr
11769 ("non-static expression used for digits value!", E);
11771 elsif Expr_Value (E) <= 0 then
11772 Error_Msg_N ("digits value must be greater than zero", E);
11774 else
11775 return;
11776 end if;
11778 -- If any of above errors occurred, then replace the incorrect
11779 -- expression by the integer 1, which should prevent further errors.
11781 Rewrite (E, Make_Integer_Literal (Sloc (E), 1));
11782 Analyze_And_Resolve (E, Standard_Integer);
11784 end Check_Digits_Expression;
11786 --------------------------
11787 -- Check_Initialization --
11788 --------------------------
11790 procedure Check_Initialization (T : Entity_Id; Exp : Node_Id) is
11791 begin
11792 -- Special processing for limited types
11794 if Is_Limited_Type (T)
11795 and then not In_Instance
11796 and then not In_Inlined_Body
11797 then
11798 if not OK_For_Limited_Init (T, Exp) then
11800 -- In GNAT mode, this is just a warning, to allow it to be evilly
11801 -- turned off. Otherwise it is a real error.
11803 if GNAT_Mode then
11804 Error_Msg_N
11805 ("??cannot initialize entities of limited type!", Exp);
11807 elsif Ada_Version < Ada_2005 then
11809 -- The side effect removal machinery may generate illegal Ada
11810 -- code to avoid the usage of access types and 'reference in
11811 -- SPARK mode. Since this is legal code with respect to theorem
11812 -- proving, do not emit the error.
11814 if GNATprove_Mode
11815 and then Nkind (Exp) = N_Function_Call
11816 and then Nkind (Parent (Exp)) = N_Object_Declaration
11817 and then not Comes_From_Source
11818 (Defining_Identifier (Parent (Exp)))
11819 then
11820 null;
11822 else
11823 Error_Msg_N
11824 ("cannot initialize entities of limited type", Exp);
11825 Explain_Limited_Type (T, Exp);
11826 end if;
11828 else
11829 -- Specialize error message according to kind of illegal
11830 -- initial expression.
11832 if Nkind (Exp) = N_Type_Conversion
11833 and then Nkind (Expression (Exp)) = N_Function_Call
11834 then
11835 -- No error for internally-generated object declarations,
11836 -- which can come from build-in-place assignment statements.
11838 if Nkind (Parent (Exp)) = N_Object_Declaration
11839 and then not Comes_From_Source
11840 (Defining_Identifier (Parent (Exp)))
11841 then
11842 null;
11844 else
11845 Error_Msg_N
11846 ("illegal context for call to function with limited "
11847 & "result", Exp);
11848 end if;
11850 else
11851 Error_Msg_N
11852 ("initialization of limited object requires aggregate or "
11853 & "function call", Exp);
11854 end if;
11855 end if;
11856 end if;
11857 end if;
11859 -- In gnatc or gnatprove mode, make sure set Do_Range_Check flag gets
11860 -- set unless we can be sure that no range check is required.
11862 if (GNATprove_Mode or not Expander_Active)
11863 and then Is_Scalar_Type (T)
11864 and then not Is_In_Range (Exp, T, Assume_Valid => True)
11865 then
11866 Set_Do_Range_Check (Exp);
11867 end if;
11868 end Check_Initialization;
11870 ----------------------
11871 -- Check_Interfaces --
11872 ----------------------
11874 procedure Check_Interfaces (N : Node_Id; Def : Node_Id) is
11875 Parent_Type : constant Entity_Id := Etype (Defining_Identifier (N));
11877 Iface : Node_Id;
11878 Iface_Def : Node_Id;
11879 Iface_Typ : Entity_Id;
11880 Parent_Node : Node_Id;
11882 Is_Task : Boolean := False;
11883 -- Set True if parent type or any progenitor is a task interface
11885 Is_Protected : Boolean := False;
11886 -- Set True if parent type or any progenitor is a protected interface
11888 procedure Check_Ifaces (Iface_Def : Node_Id; Error_Node : Node_Id);
11889 -- Check that a progenitor is compatible with declaration. If an error
11890 -- message is output, it is posted on Error_Node.
11892 ------------------
11893 -- Check_Ifaces --
11894 ------------------
11896 procedure Check_Ifaces (Iface_Def : Node_Id; Error_Node : Node_Id) is
11897 Iface_Id : constant Entity_Id :=
11898 Defining_Identifier (Parent (Iface_Def));
11899 Type_Def : Node_Id;
11901 begin
11902 if Nkind (N) = N_Private_Extension_Declaration then
11903 Type_Def := N;
11904 else
11905 Type_Def := Type_Definition (N);
11906 end if;
11908 if Is_Task_Interface (Iface_Id) then
11909 Is_Task := True;
11911 elsif Is_Protected_Interface (Iface_Id) then
11912 Is_Protected := True;
11913 end if;
11915 if Is_Synchronized_Interface (Iface_Id) then
11917 -- A consequence of 3.9.4 (6/2) and 7.3 (7.2/2) is that a private
11918 -- extension derived from a synchronized interface must explicitly
11919 -- be declared synchronized, because the full view will be a
11920 -- synchronized type.
11922 if Nkind (N) = N_Private_Extension_Declaration then
11923 if not Synchronized_Present (N) then
11924 Error_Msg_NE
11925 ("private extension of& must be explicitly synchronized",
11926 N, Iface_Id);
11927 end if;
11929 -- However, by 3.9.4(16/2), a full type that is a record extension
11930 -- is never allowed to derive from a synchronized interface (note
11931 -- that interfaces must be excluded from this check, because those
11932 -- are represented by derived type definitions in some cases).
11934 elsif Nkind (Type_Definition (N)) = N_Derived_Type_Definition
11935 and then not Interface_Present (Type_Definition (N))
11936 then
11937 Error_Msg_N ("record extension cannot derive from synchronized "
11938 & "interface", Error_Node);
11939 end if;
11940 end if;
11942 -- Check that the characteristics of the progenitor are compatible
11943 -- with the explicit qualifier in the declaration.
11944 -- The check only applies to qualifiers that come from source.
11945 -- Limited_Present also appears in the declaration of corresponding
11946 -- records, and the check does not apply to them.
11948 if Limited_Present (Type_Def)
11949 and then not
11950 Is_Concurrent_Record_Type (Defining_Identifier (N))
11951 then
11952 if Is_Limited_Interface (Parent_Type)
11953 and then not Is_Limited_Interface (Iface_Id)
11954 then
11955 Error_Msg_NE
11956 ("progenitor & must be limited interface",
11957 Error_Node, Iface_Id);
11959 elsif
11960 (Task_Present (Iface_Def)
11961 or else Protected_Present (Iface_Def)
11962 or else Synchronized_Present (Iface_Def))
11963 and then Nkind (N) /= N_Private_Extension_Declaration
11964 and then not Error_Posted (N)
11965 then
11966 Error_Msg_NE
11967 ("progenitor & must be limited interface",
11968 Error_Node, Iface_Id);
11969 end if;
11971 -- Protected interfaces can only inherit from limited, synchronized
11972 -- or protected interfaces.
11974 elsif Nkind (N) = N_Full_Type_Declaration
11975 and then Protected_Present (Type_Def)
11976 then
11977 if Limited_Present (Iface_Def)
11978 or else Synchronized_Present (Iface_Def)
11979 or else Protected_Present (Iface_Def)
11980 then
11981 null;
11983 elsif Task_Present (Iface_Def) then
11984 Error_Msg_N ("(Ada 2005) protected interface cannot inherit "
11985 & "from task interface", Error_Node);
11987 else
11988 Error_Msg_N ("(Ada 2005) protected interface cannot inherit "
11989 & "from non-limited interface", Error_Node);
11990 end if;
11992 -- Ada 2005 (AI-345): Synchronized interfaces can only inherit from
11993 -- limited and synchronized.
11995 elsif Synchronized_Present (Type_Def) then
11996 if Limited_Present (Iface_Def)
11997 or else Synchronized_Present (Iface_Def)
11998 then
11999 null;
12001 elsif Protected_Present (Iface_Def)
12002 and then Nkind (N) /= N_Private_Extension_Declaration
12003 then
12004 Error_Msg_N ("(Ada 2005) synchronized interface cannot inherit "
12005 & "from protected interface", Error_Node);
12007 elsif Task_Present (Iface_Def)
12008 and then Nkind (N) /= N_Private_Extension_Declaration
12009 then
12010 Error_Msg_N ("(Ada 2005) synchronized interface cannot inherit "
12011 & "from task interface", Error_Node);
12013 elsif not Is_Limited_Interface (Iface_Id) then
12014 Error_Msg_N ("(Ada 2005) synchronized interface cannot inherit "
12015 & "from non-limited interface", Error_Node);
12016 end if;
12018 -- Ada 2005 (AI-345): Task interfaces can only inherit from limited,
12019 -- synchronized or task interfaces.
12021 elsif Nkind (N) = N_Full_Type_Declaration
12022 and then Task_Present (Type_Def)
12023 then
12024 if Limited_Present (Iface_Def)
12025 or else Synchronized_Present (Iface_Def)
12026 or else Task_Present (Iface_Def)
12027 then
12028 null;
12030 elsif Protected_Present (Iface_Def) then
12031 Error_Msg_N ("(Ada 2005) task interface cannot inherit from "
12032 & "protected interface", Error_Node);
12034 else
12035 Error_Msg_N ("(Ada 2005) task interface cannot inherit from "
12036 & "non-limited interface", Error_Node);
12037 end if;
12038 end if;
12039 end Check_Ifaces;
12041 -- Start of processing for Check_Interfaces
12043 begin
12044 if Is_Interface (Parent_Type) then
12045 if Is_Task_Interface (Parent_Type) then
12046 Is_Task := True;
12048 elsif Is_Protected_Interface (Parent_Type) then
12049 Is_Protected := True;
12050 end if;
12051 end if;
12053 if Nkind (N) = N_Private_Extension_Declaration then
12055 -- Check that progenitors are compatible with declaration
12057 Iface := First (Interface_List (Def));
12058 while Present (Iface) loop
12059 Iface_Typ := Find_Type_Of_Subtype_Indic (Iface);
12061 Parent_Node := Parent (Base_Type (Iface_Typ));
12062 Iface_Def := Type_Definition (Parent_Node);
12064 if not Is_Interface (Iface_Typ) then
12065 Diagnose_Interface (Iface, Iface_Typ);
12066 else
12067 Check_Ifaces (Iface_Def, Iface);
12068 end if;
12070 Next (Iface);
12071 end loop;
12073 if Is_Task and Is_Protected then
12074 Error_Msg_N
12075 ("type cannot derive from task and protected interface", N);
12076 end if;
12078 return;
12079 end if;
12081 -- Full type declaration of derived type.
12082 -- Check compatibility with parent if it is interface type
12084 if Nkind (Type_Definition (N)) = N_Derived_Type_Definition
12085 and then Is_Interface (Parent_Type)
12086 then
12087 Parent_Node := Parent (Parent_Type);
12089 -- More detailed checks for interface varieties
12091 Check_Ifaces
12092 (Iface_Def => Type_Definition (Parent_Node),
12093 Error_Node => Subtype_Indication (Type_Definition (N)));
12094 end if;
12096 Iface := First (Interface_List (Def));
12097 while Present (Iface) loop
12098 Iface_Typ := Find_Type_Of_Subtype_Indic (Iface);
12100 Parent_Node := Parent (Base_Type (Iface_Typ));
12101 Iface_Def := Type_Definition (Parent_Node);
12103 if not Is_Interface (Iface_Typ) then
12104 Diagnose_Interface (Iface, Iface_Typ);
12106 else
12107 -- "The declaration of a specific descendant of an interface
12108 -- type freezes the interface type" RM 13.14
12110 Freeze_Before (N, Iface_Typ);
12111 Check_Ifaces (Iface_Def, Error_Node => Iface);
12112 end if;
12114 Next (Iface);
12115 end loop;
12117 if Is_Task and Is_Protected then
12118 Error_Msg_N
12119 ("type cannot derive from task and protected interface", N);
12120 end if;
12121 end Check_Interfaces;
12123 ------------------------------------
12124 -- Check_Or_Process_Discriminants --
12125 ------------------------------------
12127 -- If an incomplete or private type declaration was already given for the
12128 -- type, the discriminants may have already been processed if they were
12129 -- present on the incomplete declaration. In this case a full conformance
12130 -- check has been performed in Find_Type_Name, and we then recheck here
12131 -- some properties that can't be checked on the partial view alone.
12132 -- Otherwise we call Process_Discriminants.
12134 procedure Check_Or_Process_Discriminants
12135 (N : Node_Id;
12136 T : Entity_Id;
12137 Prev : Entity_Id := Empty)
12139 begin
12140 if Has_Discriminants (T) then
12142 -- Discriminants are already set on T if they were already present
12143 -- on the partial view. Make them visible to component declarations.
12145 declare
12146 D : Entity_Id;
12147 -- Discriminant on T (full view) referencing expr on partial view
12149 Prev_D : Entity_Id;
12150 -- Entity of corresponding discriminant on partial view
12152 New_D : Node_Id;
12153 -- Discriminant specification for full view, expression is
12154 -- the syntactic copy on full view (which has been checked for
12155 -- conformance with partial view), only used here to post error
12156 -- message.
12158 begin
12159 D := First_Discriminant (T);
12160 New_D := First (Discriminant_Specifications (N));
12161 while Present (D) loop
12162 Prev_D := Current_Entity (D);
12163 Set_Current_Entity (D);
12164 Set_Is_Immediately_Visible (D);
12165 Set_Homonym (D, Prev_D);
12167 -- Handle the case where there is an untagged partial view and
12168 -- the full view is tagged: must disallow discriminants with
12169 -- defaults, unless compiling for Ada 2012, which allows a
12170 -- limited tagged type to have defaulted discriminants (see
12171 -- AI05-0214). However, suppress error here if it was already
12172 -- reported on the default expression of the partial view.
12174 if Is_Tagged_Type (T)
12175 and then Present (Expression (Parent (D)))
12176 and then (not Is_Limited_Type (Current_Scope)
12177 or else Ada_Version < Ada_2012)
12178 and then not Error_Posted (Expression (Parent (D)))
12179 then
12180 if Ada_Version >= Ada_2012 then
12181 Error_Msg_N
12182 ("discriminants of nonlimited tagged type cannot have "
12183 & "defaults",
12184 Expression (New_D));
12185 else
12186 Error_Msg_N
12187 ("discriminants of tagged type cannot have defaults",
12188 Expression (New_D));
12189 end if;
12190 end if;
12192 -- Ada 2005 (AI-230): Access discriminant allowed in
12193 -- non-limited record types.
12195 if Ada_Version < Ada_2005 then
12197 -- This restriction gets applied to the full type here. It
12198 -- has already been applied earlier to the partial view.
12200 Check_Access_Discriminant_Requires_Limited (Parent (D), N);
12201 end if;
12203 Next_Discriminant (D);
12204 Next (New_D);
12205 end loop;
12206 end;
12208 elsif Present (Discriminant_Specifications (N)) then
12209 Process_Discriminants (N, Prev);
12210 end if;
12211 end Check_Or_Process_Discriminants;
12213 ----------------------
12214 -- Check_Real_Bound --
12215 ----------------------
12217 procedure Check_Real_Bound (Bound : Node_Id) is
12218 begin
12219 if not Is_Real_Type (Etype (Bound)) then
12220 Error_Msg_N
12221 ("bound in real type definition must be of real type", Bound);
12223 elsif not Is_OK_Static_Expression (Bound) then
12224 Flag_Non_Static_Expr
12225 ("non-static expression used for real type bound!", Bound);
12227 else
12228 return;
12229 end if;
12231 Rewrite
12232 (Bound, Make_Real_Literal (Sloc (Bound), Ureal_0));
12233 Analyze (Bound);
12234 Resolve (Bound, Standard_Float);
12235 end Check_Real_Bound;
12237 ------------------------------
12238 -- Complete_Private_Subtype --
12239 ------------------------------
12241 procedure Complete_Private_Subtype
12242 (Priv : Entity_Id;
12243 Full : Entity_Id;
12244 Full_Base : Entity_Id;
12245 Related_Nod : Node_Id)
12247 Save_Next_Entity : Entity_Id;
12248 Save_Homonym : Entity_Id;
12250 begin
12251 -- Set semantic attributes for (implicit) private subtype completion.
12252 -- If the full type has no discriminants, then it is a copy of the
12253 -- full view of the base. Otherwise, it is a subtype of the base with
12254 -- a possible discriminant constraint. Save and restore the original
12255 -- Next_Entity field of full to ensure that the calls to Copy_Node do
12256 -- not corrupt the entity chain.
12258 -- Note that the type of the full view is the same entity as the type
12259 -- of the partial view. In this fashion, the subtype has access to the
12260 -- correct view of the parent.
12262 Save_Next_Entity := Next_Entity (Full);
12263 Save_Homonym := Homonym (Priv);
12265 case Ekind (Full_Base) is
12266 when Class_Wide_Kind
12267 | Private_Kind
12268 | Protected_Kind
12269 | Task_Kind
12270 | E_Record_Subtype
12271 | E_Record_Type
12273 Copy_Node (Priv, Full);
12275 Set_Has_Discriminants
12276 (Full, Has_Discriminants (Full_Base));
12277 Set_Has_Unknown_Discriminants
12278 (Full, Has_Unknown_Discriminants (Full_Base));
12279 Set_First_Entity (Full, First_Entity (Full_Base));
12280 Set_Last_Entity (Full, Last_Entity (Full_Base));
12282 -- If the underlying base type is constrained, we know that the
12283 -- full view of the subtype is constrained as well (the converse
12284 -- is not necessarily true).
12286 if Is_Constrained (Full_Base) then
12287 Set_Is_Constrained (Full);
12288 end if;
12290 when others =>
12291 Copy_Node (Full_Base, Full);
12293 Set_Chars (Full, Chars (Priv));
12294 Conditional_Delay (Full, Priv);
12295 Set_Sloc (Full, Sloc (Priv));
12296 end case;
12298 Set_Next_Entity (Full, Save_Next_Entity);
12299 Set_Homonym (Full, Save_Homonym);
12300 Set_Associated_Node_For_Itype (Full, Related_Nod);
12302 -- Set common attributes for all subtypes: kind, convention, etc.
12304 Set_Ekind (Full, Subtype_Kind (Ekind (Full_Base)));
12305 Set_Convention (Full, Convention (Full_Base));
12307 -- The Etype of the full view is inconsistent. Gigi needs to see the
12308 -- structural full view, which is what the current scheme gives: the
12309 -- Etype of the full view is the etype of the full base. However, if the
12310 -- full base is a derived type, the full view then looks like a subtype
12311 -- of the parent, not a subtype of the full base. If instead we write:
12313 -- Set_Etype (Full, Full_Base);
12315 -- then we get inconsistencies in the front-end (confusion between
12316 -- views). Several outstanding bugs are related to this ???
12318 Set_Is_First_Subtype (Full, False);
12319 Set_Scope (Full, Scope (Priv));
12320 Set_Size_Info (Full, Full_Base);
12321 Set_RM_Size (Full, RM_Size (Full_Base));
12322 Set_Is_Itype (Full);
12324 -- A subtype of a private-type-without-discriminants, whose full-view
12325 -- has discriminants with default expressions, is not constrained.
12327 if not Has_Discriminants (Priv) then
12328 Set_Is_Constrained (Full, Is_Constrained (Full_Base));
12330 if Has_Discriminants (Full_Base) then
12331 Set_Discriminant_Constraint
12332 (Full, Discriminant_Constraint (Full_Base));
12334 -- The partial view may have been indefinite, the full view
12335 -- might not be.
12337 Set_Has_Unknown_Discriminants
12338 (Full, Has_Unknown_Discriminants (Full_Base));
12339 end if;
12340 end if;
12342 Set_First_Rep_Item (Full, First_Rep_Item (Full_Base));
12343 Set_Depends_On_Private (Full, Has_Private_Component (Full));
12345 -- Freeze the private subtype entity if its parent is delayed, and not
12346 -- already frozen. We skip this processing if the type is an anonymous
12347 -- subtype of a record component, or is the corresponding record of a
12348 -- protected type, since these are processed when the enclosing type
12349 -- is frozen. If the parent type is declared in a nested package then
12350 -- the freezing of the private and full views also happens later.
12352 if not Is_Type (Scope (Full)) then
12353 if Is_Itype (Priv)
12354 and then In_Same_Source_Unit (Full, Full_Base)
12355 and then Scope (Full_Base) /= Scope (Full)
12356 then
12357 Set_Has_Delayed_Freeze (Full);
12358 Set_Has_Delayed_Freeze (Priv);
12360 else
12361 Set_Has_Delayed_Freeze (Full,
12362 Has_Delayed_Freeze (Full_Base)
12363 and then not Is_Frozen (Full_Base));
12364 end if;
12365 end if;
12367 Set_Freeze_Node (Full, Empty);
12368 Set_Is_Frozen (Full, False);
12369 Set_Full_View (Priv, Full);
12371 if Has_Discriminants (Full) then
12372 Set_Stored_Constraint_From_Discriminant_Constraint (Full);
12373 Set_Stored_Constraint (Priv, Stored_Constraint (Full));
12375 if Has_Unknown_Discriminants (Full) then
12376 Set_Discriminant_Constraint (Full, No_Elist);
12377 end if;
12378 end if;
12380 if Ekind (Full_Base) = E_Record_Type
12381 and then Has_Discriminants (Full_Base)
12382 and then Has_Discriminants (Priv) -- might not, if errors
12383 and then not Has_Unknown_Discriminants (Priv)
12384 and then not Is_Empty_Elmt_List (Discriminant_Constraint (Priv))
12385 then
12386 Create_Constrained_Components
12387 (Full, Related_Nod, Full_Base, Discriminant_Constraint (Priv));
12389 -- If the full base is itself derived from private, build a congruent
12390 -- subtype of its underlying type, for use by the back end. For a
12391 -- constrained record component, the declaration cannot be placed on
12392 -- the component list, but it must nevertheless be built an analyzed, to
12393 -- supply enough information for Gigi to compute the size of component.
12395 elsif Ekind (Full_Base) in Private_Kind
12396 and then Is_Derived_Type (Full_Base)
12397 and then Has_Discriminants (Full_Base)
12398 and then (Ekind (Current_Scope) /= E_Record_Subtype)
12399 then
12400 if not Is_Itype (Priv)
12401 and then
12402 Nkind (Subtype_Indication (Parent (Priv))) = N_Subtype_Indication
12403 then
12404 Build_Underlying_Full_View
12405 (Parent (Priv), Full, Etype (Full_Base));
12407 elsif Nkind (Related_Nod) = N_Component_Declaration then
12408 Build_Underlying_Full_View (Related_Nod, Full, Etype (Full_Base));
12409 end if;
12411 elsif Is_Record_Type (Full_Base) then
12413 -- Show Full is simply a renaming of Full_Base
12415 Set_Cloned_Subtype (Full, Full_Base);
12416 end if;
12418 -- It is unsafe to share the bounds of a scalar type, because the Itype
12419 -- is elaborated on demand, and if a bound is non-static then different
12420 -- orders of elaboration in different units will lead to different
12421 -- external symbols.
12423 if Is_Scalar_Type (Full_Base) then
12424 Set_Scalar_Range (Full,
12425 Make_Range (Sloc (Related_Nod),
12426 Low_Bound =>
12427 Duplicate_Subexpr_No_Checks (Type_Low_Bound (Full_Base)),
12428 High_Bound =>
12429 Duplicate_Subexpr_No_Checks (Type_High_Bound (Full_Base))));
12431 -- This completion inherits the bounds of the full parent, but if
12432 -- the parent is an unconstrained floating point type, so is the
12433 -- completion.
12435 if Is_Floating_Point_Type (Full_Base) then
12436 Set_Includes_Infinities
12437 (Scalar_Range (Full), Has_Infinities (Full_Base));
12438 end if;
12439 end if;
12441 -- ??? It seems that a lot of fields are missing that should be copied
12442 -- from Full_Base to Full. Here are some that are introduced in a
12443 -- non-disruptive way but a cleanup is necessary.
12445 if Is_Tagged_Type (Full_Base) then
12446 Set_Is_Tagged_Type (Full);
12447 Set_Direct_Primitive_Operations
12448 (Full, Direct_Primitive_Operations (Full_Base));
12449 Set_No_Tagged_Streams_Pragma
12450 (Full, No_Tagged_Streams_Pragma (Full_Base));
12452 -- Inherit class_wide type of full_base in case the partial view was
12453 -- not tagged. Otherwise it has already been created when the private
12454 -- subtype was analyzed.
12456 if No (Class_Wide_Type (Full)) then
12457 Set_Class_Wide_Type (Full, Class_Wide_Type (Full_Base));
12458 end if;
12460 -- If this is a subtype of a protected or task type, constrain its
12461 -- corresponding record, unless this is a subtype without constraints,
12462 -- i.e. a simple renaming as with an actual subtype in an instance.
12464 elsif Is_Concurrent_Type (Full_Base) then
12465 if Has_Discriminants (Full)
12466 and then Present (Corresponding_Record_Type (Full_Base))
12467 and then
12468 not Is_Empty_Elmt_List (Discriminant_Constraint (Full))
12469 then
12470 Set_Corresponding_Record_Type (Full,
12471 Constrain_Corresponding_Record
12472 (Full, Corresponding_Record_Type (Full_Base), Related_Nod));
12474 else
12475 Set_Corresponding_Record_Type (Full,
12476 Corresponding_Record_Type (Full_Base));
12477 end if;
12478 end if;
12480 -- Link rep item chain, and also setting of Has_Predicates from private
12481 -- subtype to full subtype, since we will need these on the full subtype
12482 -- to create the predicate function. Note that the full subtype may
12483 -- already have rep items, inherited from the full view of the base
12484 -- type, so we must be sure not to overwrite these entries.
12486 declare
12487 Append : Boolean;
12488 Item : Node_Id;
12489 Next_Item : Node_Id;
12490 Priv_Item : Node_Id;
12492 begin
12493 Item := First_Rep_Item (Full);
12494 Priv_Item := First_Rep_Item (Priv);
12496 -- If no existing rep items on full type, we can just link directly
12497 -- to the list of items on the private type, if any exist.. Same if
12498 -- the rep items are only those inherited from the base
12500 if (No (Item)
12501 or else Nkind (Item) /= N_Aspect_Specification
12502 or else Entity (Item) = Full_Base)
12503 and then Present (First_Rep_Item (Priv))
12504 then
12505 Set_First_Rep_Item (Full, Priv_Item);
12507 -- Otherwise, search to the end of items currently linked to the full
12508 -- subtype and append the private items to the end. However, if Priv
12509 -- and Full already have the same list of rep items, then the append
12510 -- is not done, as that would create a circularity.
12512 -- The partial view may have a predicate and the rep item lists of
12513 -- both views agree when inherited from the same ancestor. In that
12514 -- case, simply propagate the list from one view to the other.
12515 -- A more complex analysis needed here ???
12517 elsif Present (Priv_Item)
12518 and then Item = Next_Rep_Item (Priv_Item)
12519 then
12520 Set_First_Rep_Item (Full, Priv_Item);
12522 elsif Item /= Priv_Item then
12523 Append := True;
12524 loop
12525 Next_Item := Next_Rep_Item (Item);
12526 exit when No (Next_Item);
12527 Item := Next_Item;
12529 -- If the private view has aspect specifications, the full view
12530 -- inherits them. Since these aspects may already have been
12531 -- attached to the full view during derivation, do not append
12532 -- them if already present.
12534 if Item = First_Rep_Item (Priv) then
12535 Append := False;
12536 exit;
12537 end if;
12538 end loop;
12540 -- And link the private type items at the end of the chain
12542 if Append then
12543 Set_Next_Rep_Item (Item, First_Rep_Item (Priv));
12544 end if;
12545 end if;
12546 end;
12548 -- Make sure Has_Predicates is set on full type if it is set on the
12549 -- private type. Note that it may already be set on the full type and
12550 -- if so, we don't want to unset it. Similarly, propagate information
12551 -- about delayed aspects, because the corresponding pragmas must be
12552 -- analyzed when one of the views is frozen. This last step is needed
12553 -- in particular when the full type is a scalar type for which an
12554 -- anonymous base type is constructed.
12556 -- The predicate functions are generated either at the freeze point
12557 -- of the type or at the end of the visible part, and we must avoid
12558 -- generating them twice.
12560 if Has_Predicates (Priv) then
12561 Set_Has_Predicates (Full);
12563 if Present (Predicate_Function (Priv))
12564 and then No (Predicate_Function (Full))
12565 then
12566 Set_Predicate_Function (Full, Predicate_Function (Priv));
12567 end if;
12568 end if;
12570 if Has_Delayed_Aspects (Priv) then
12571 Set_Has_Delayed_Aspects (Full);
12572 end if;
12573 end Complete_Private_Subtype;
12575 ----------------------------
12576 -- Constant_Redeclaration --
12577 ----------------------------
12579 procedure Constant_Redeclaration
12580 (Id : Entity_Id;
12581 N : Node_Id;
12582 T : out Entity_Id)
12584 Prev : constant Entity_Id := Current_Entity_In_Scope (Id);
12585 Obj_Def : constant Node_Id := Object_Definition (N);
12586 New_T : Entity_Id;
12588 procedure Check_Possible_Deferred_Completion
12589 (Prev_Id : Entity_Id;
12590 Prev_Obj_Def : Node_Id;
12591 Curr_Obj_Def : Node_Id);
12592 -- Determine whether the two object definitions describe the partial
12593 -- and the full view of a constrained deferred constant. Generate
12594 -- a subtype for the full view and verify that it statically matches
12595 -- the subtype of the partial view.
12597 procedure Check_Recursive_Declaration (Typ : Entity_Id);
12598 -- If deferred constant is an access type initialized with an allocator,
12599 -- check whether there is an illegal recursion in the definition,
12600 -- through a default value of some record subcomponent. This is normally
12601 -- detected when generating init procs, but requires this additional
12602 -- mechanism when expansion is disabled.
12604 ----------------------------------------
12605 -- Check_Possible_Deferred_Completion --
12606 ----------------------------------------
12608 procedure Check_Possible_Deferred_Completion
12609 (Prev_Id : Entity_Id;
12610 Prev_Obj_Def : Node_Id;
12611 Curr_Obj_Def : Node_Id)
12613 begin
12614 if Nkind (Prev_Obj_Def) = N_Subtype_Indication
12615 and then Present (Constraint (Prev_Obj_Def))
12616 and then Nkind (Curr_Obj_Def) = N_Subtype_Indication
12617 and then Present (Constraint (Curr_Obj_Def))
12618 then
12619 declare
12620 Loc : constant Source_Ptr := Sloc (N);
12621 Def_Id : constant Entity_Id := Make_Temporary (Loc, 'S');
12622 Decl : constant Node_Id :=
12623 Make_Subtype_Declaration (Loc,
12624 Defining_Identifier => Def_Id,
12625 Subtype_Indication =>
12626 Relocate_Node (Curr_Obj_Def));
12628 begin
12629 Insert_Before_And_Analyze (N, Decl);
12630 Set_Etype (Id, Def_Id);
12632 if not Subtypes_Statically_Match (Etype (Prev_Id), Def_Id) then
12633 Error_Msg_Sloc := Sloc (Prev_Id);
12634 Error_Msg_N ("subtype does not statically match deferred "
12635 & "declaration #", N);
12636 end if;
12637 end;
12638 end if;
12639 end Check_Possible_Deferred_Completion;
12641 ---------------------------------
12642 -- Check_Recursive_Declaration --
12643 ---------------------------------
12645 procedure Check_Recursive_Declaration (Typ : Entity_Id) is
12646 Comp : Entity_Id;
12648 begin
12649 if Is_Record_Type (Typ) then
12650 Comp := First_Component (Typ);
12651 while Present (Comp) loop
12652 if Comes_From_Source (Comp) then
12653 if Present (Expression (Parent (Comp)))
12654 and then Is_Entity_Name (Expression (Parent (Comp)))
12655 and then Entity (Expression (Parent (Comp))) = Prev
12656 then
12657 Error_Msg_Sloc := Sloc (Parent (Comp));
12658 Error_Msg_NE
12659 ("illegal circularity with declaration for & #",
12660 N, Comp);
12661 return;
12663 elsif Is_Record_Type (Etype (Comp)) then
12664 Check_Recursive_Declaration (Etype (Comp));
12665 end if;
12666 end if;
12668 Next_Component (Comp);
12669 end loop;
12670 end if;
12671 end Check_Recursive_Declaration;
12673 -- Start of processing for Constant_Redeclaration
12675 begin
12676 if Nkind (Parent (Prev)) = N_Object_Declaration then
12677 if Nkind (Object_Definition
12678 (Parent (Prev))) = N_Subtype_Indication
12679 then
12680 -- Find type of new declaration. The constraints of the two
12681 -- views must match statically, but there is no point in
12682 -- creating an itype for the full view.
12684 if Nkind (Obj_Def) = N_Subtype_Indication then
12685 Find_Type (Subtype_Mark (Obj_Def));
12686 New_T := Entity (Subtype_Mark (Obj_Def));
12688 else
12689 Find_Type (Obj_Def);
12690 New_T := Entity (Obj_Def);
12691 end if;
12693 T := Etype (Prev);
12695 else
12696 -- The full view may impose a constraint, even if the partial
12697 -- view does not, so construct the subtype.
12699 New_T := Find_Type_Of_Object (Obj_Def, N);
12700 T := New_T;
12701 end if;
12703 else
12704 -- Current declaration is illegal, diagnosed below in Enter_Name
12706 T := Empty;
12707 New_T := Any_Type;
12708 end if;
12710 -- If previous full declaration or a renaming declaration exists, or if
12711 -- a homograph is present, let Enter_Name handle it, either with an
12712 -- error or with the removal of an overridden implicit subprogram.
12713 -- The previous one is a full declaration if it has an expression
12714 -- (which in the case of an aggregate is indicated by the Init flag).
12716 if Ekind (Prev) /= E_Constant
12717 or else Nkind (Parent (Prev)) = N_Object_Renaming_Declaration
12718 or else Present (Expression (Parent (Prev)))
12719 or else Has_Init_Expression (Parent (Prev))
12720 or else Present (Full_View (Prev))
12721 then
12722 Enter_Name (Id);
12724 -- Verify that types of both declarations match, or else that both types
12725 -- are anonymous access types whose designated subtypes statically match
12726 -- (as allowed in Ada 2005 by AI-385).
12728 elsif Base_Type (Etype (Prev)) /= Base_Type (New_T)
12729 and then
12730 (Ekind (Etype (Prev)) /= E_Anonymous_Access_Type
12731 or else Ekind (Etype (New_T)) /= E_Anonymous_Access_Type
12732 or else Is_Access_Constant (Etype (New_T)) /=
12733 Is_Access_Constant (Etype (Prev))
12734 or else Can_Never_Be_Null (Etype (New_T)) /=
12735 Can_Never_Be_Null (Etype (Prev))
12736 or else Null_Exclusion_Present (Parent (Prev)) /=
12737 Null_Exclusion_Present (Parent (Id))
12738 or else not Subtypes_Statically_Match
12739 (Designated_Type (Etype (Prev)),
12740 Designated_Type (Etype (New_T))))
12741 then
12742 Error_Msg_Sloc := Sloc (Prev);
12743 Error_Msg_N ("type does not match declaration#", N);
12744 Set_Full_View (Prev, Id);
12745 Set_Etype (Id, Any_Type);
12747 -- A deferred constant whose type is an anonymous array is always
12748 -- illegal (unless imported). A detailed error message might be
12749 -- helpful for Ada beginners.
12751 if Nkind (Object_Definition (Parent (Prev)))
12752 = N_Constrained_Array_Definition
12753 and then Nkind (Object_Definition (N))
12754 = N_Constrained_Array_Definition
12755 then
12756 Error_Msg_N ("\each anonymous array is a distinct type", N);
12757 Error_Msg_N ("a deferred constant must have a named type",
12758 Object_Definition (Parent (Prev)));
12759 end if;
12761 elsif
12762 Null_Exclusion_Present (Parent (Prev))
12763 and then not Null_Exclusion_Present (N)
12764 then
12765 Error_Msg_Sloc := Sloc (Prev);
12766 Error_Msg_N ("null-exclusion does not match declaration#", N);
12767 Set_Full_View (Prev, Id);
12768 Set_Etype (Id, Any_Type);
12770 -- If so, process the full constant declaration
12772 else
12773 -- RM 7.4 (6): If the subtype defined by the subtype_indication in
12774 -- the deferred declaration is constrained, then the subtype defined
12775 -- by the subtype_indication in the full declaration shall match it
12776 -- statically.
12778 Check_Possible_Deferred_Completion
12779 (Prev_Id => Prev,
12780 Prev_Obj_Def => Object_Definition (Parent (Prev)),
12781 Curr_Obj_Def => Obj_Def);
12783 Set_Full_View (Prev, Id);
12784 Set_Is_Public (Id, Is_Public (Prev));
12785 Set_Is_Internal (Id);
12786 Append_Entity (Id, Current_Scope);
12788 -- Check ALIASED present if present before (RM 7.4(7))
12790 if Is_Aliased (Prev)
12791 and then not Aliased_Present (N)
12792 then
12793 Error_Msg_Sloc := Sloc (Prev);
12794 Error_Msg_N ("ALIASED required (see declaration #)", N);
12795 end if;
12797 -- Check that placement is in private part and that the incomplete
12798 -- declaration appeared in the visible part.
12800 if Ekind (Current_Scope) = E_Package
12801 and then not In_Private_Part (Current_Scope)
12802 then
12803 Error_Msg_Sloc := Sloc (Prev);
12804 Error_Msg_N
12805 ("full constant for declaration # must be in private part", N);
12807 elsif Ekind (Current_Scope) = E_Package
12808 and then
12809 List_Containing (Parent (Prev)) /=
12810 Visible_Declarations (Package_Specification (Current_Scope))
12811 then
12812 Error_Msg_N
12813 ("deferred constant must be declared in visible part",
12814 Parent (Prev));
12815 end if;
12817 if Is_Access_Type (T)
12818 and then Nkind (Expression (N)) = N_Allocator
12819 then
12820 Check_Recursive_Declaration (Designated_Type (T));
12821 end if;
12823 -- A deferred constant is a visible entity. If type has invariants,
12824 -- verify that the initial value satisfies them. This is not done in
12825 -- GNATprove mode, as GNATprove handles invariant checks itself.
12827 if Has_Invariants (T)
12828 and then Present (Invariant_Procedure (T))
12829 and then not GNATprove_Mode
12830 then
12831 Insert_After (N,
12832 Make_Invariant_Call (New_Occurrence_Of (Prev, Sloc (N))));
12833 end if;
12834 end if;
12835 end Constant_Redeclaration;
12837 ----------------------
12838 -- Constrain_Access --
12839 ----------------------
12841 procedure Constrain_Access
12842 (Def_Id : in out Entity_Id;
12843 S : Node_Id;
12844 Related_Nod : Node_Id)
12846 T : constant Entity_Id := Entity (Subtype_Mark (S));
12847 Desig_Type : constant Entity_Id := Designated_Type (T);
12848 Desig_Subtype : Entity_Id := Create_Itype (E_Void, Related_Nod);
12849 Constraint_OK : Boolean := True;
12851 begin
12852 if Is_Array_Type (Desig_Type) then
12853 Constrain_Array (Desig_Subtype, S, Related_Nod, Def_Id, 'P');
12855 elsif (Is_Record_Type (Desig_Type)
12856 or else Is_Incomplete_Or_Private_Type (Desig_Type))
12857 and then not Is_Constrained (Desig_Type)
12858 then
12859 -- ??? The following code is a temporary bypass to ignore a
12860 -- discriminant constraint on access type if it is constraining
12861 -- the current record. Avoid creating the implicit subtype of the
12862 -- record we are currently compiling since right now, we cannot
12863 -- handle these. For now, just return the access type itself.
12865 if Desig_Type = Current_Scope
12866 and then No (Def_Id)
12867 then
12868 Set_Ekind (Desig_Subtype, E_Record_Subtype);
12869 Def_Id := Entity (Subtype_Mark (S));
12871 -- This call added to ensure that the constraint is analyzed
12872 -- (needed for a B test). Note that we still return early from
12873 -- this procedure to avoid recursive processing. ???
12875 Constrain_Discriminated_Type
12876 (Desig_Subtype, S, Related_Nod, For_Access => True);
12877 return;
12878 end if;
12880 -- Enforce rule that the constraint is illegal if there is an
12881 -- unconstrained view of the designated type. This means that the
12882 -- partial view (either a private type declaration or a derivation
12883 -- from a private type) has no discriminants. (Defect Report
12884 -- 8652/0008, Technical Corrigendum 1, checked by ACATS B371001).
12886 -- Rule updated for Ada 2005: The private type is said to have
12887 -- a constrained partial view, given that objects of the type
12888 -- can be declared. Furthermore, the rule applies to all access
12889 -- types, unlike the rule concerning default discriminants (see
12890 -- RM 3.7.1(7/3))
12892 if (Ekind (T) = E_General_Access_Type or else Ada_Version >= Ada_2005)
12893 and then Has_Private_Declaration (Desig_Type)
12894 and then In_Open_Scopes (Scope (Desig_Type))
12895 and then Has_Discriminants (Desig_Type)
12896 then
12897 declare
12898 Pack : constant Node_Id :=
12899 Unit_Declaration_Node (Scope (Desig_Type));
12900 Decls : List_Id;
12901 Decl : Node_Id;
12903 begin
12904 if Nkind (Pack) = N_Package_Declaration then
12905 Decls := Visible_Declarations (Specification (Pack));
12906 Decl := First (Decls);
12907 while Present (Decl) loop
12908 if (Nkind (Decl) = N_Private_Type_Declaration
12909 and then Chars (Defining_Identifier (Decl)) =
12910 Chars (Desig_Type))
12912 or else
12913 (Nkind (Decl) = N_Full_Type_Declaration
12914 and then
12915 Chars (Defining_Identifier (Decl)) =
12916 Chars (Desig_Type)
12917 and then Is_Derived_Type (Desig_Type)
12918 and then
12919 Has_Private_Declaration (Etype (Desig_Type)))
12920 then
12921 if No (Discriminant_Specifications (Decl)) then
12922 Error_Msg_N
12923 ("cannot constrain access type if designated "
12924 & "type has constrained partial view", S);
12925 end if;
12927 exit;
12928 end if;
12930 Next (Decl);
12931 end loop;
12932 end if;
12933 end;
12934 end if;
12936 Constrain_Discriminated_Type (Desig_Subtype, S, Related_Nod,
12937 For_Access => True);
12939 elsif Is_Concurrent_Type (Desig_Type)
12940 and then not Is_Constrained (Desig_Type)
12941 then
12942 Constrain_Concurrent (Desig_Subtype, S, Related_Nod, Desig_Type, ' ');
12944 else
12945 Error_Msg_N ("invalid constraint on access type", S);
12947 -- We simply ignore an invalid constraint
12949 Desig_Subtype := Desig_Type;
12950 Constraint_OK := False;
12951 end if;
12953 if No (Def_Id) then
12954 Def_Id := Create_Itype (E_Access_Subtype, Related_Nod);
12955 else
12956 Set_Ekind (Def_Id, E_Access_Subtype);
12957 end if;
12959 if Constraint_OK then
12960 Set_Etype (Def_Id, Base_Type (T));
12962 if Is_Private_Type (Desig_Type) then
12963 Prepare_Private_Subtype_Completion (Desig_Subtype, Related_Nod);
12964 end if;
12965 else
12966 Set_Etype (Def_Id, Any_Type);
12967 end if;
12969 Set_Size_Info (Def_Id, T);
12970 Set_Is_Constrained (Def_Id, Constraint_OK);
12971 Set_Directly_Designated_Type (Def_Id, Desig_Subtype);
12972 Set_Depends_On_Private (Def_Id, Has_Private_Component (Def_Id));
12973 Set_Is_Access_Constant (Def_Id, Is_Access_Constant (T));
12975 Conditional_Delay (Def_Id, T);
12977 -- AI-363 : Subtypes of general access types whose designated types have
12978 -- default discriminants are disallowed. In instances, the rule has to
12979 -- be checked against the actual, of which T is the subtype. In a
12980 -- generic body, the rule is checked assuming that the actual type has
12981 -- defaulted discriminants.
12983 if Ada_Version >= Ada_2005 or else Warn_On_Ada_2005_Compatibility then
12984 if Ekind (Base_Type (T)) = E_General_Access_Type
12985 and then Has_Defaulted_Discriminants (Desig_Type)
12986 then
12987 if Ada_Version < Ada_2005 then
12988 Error_Msg_N
12989 ("access subtype of general access type would not " &
12990 "be allowed in Ada 2005?y?", S);
12991 else
12992 Error_Msg_N
12993 ("access subtype of general access type not allowed", S);
12994 end if;
12996 Error_Msg_N ("\discriminants have defaults", S);
12998 elsif Is_Access_Type (T)
12999 and then Is_Generic_Type (Desig_Type)
13000 and then Has_Discriminants (Desig_Type)
13001 and then In_Package_Body (Current_Scope)
13002 then
13003 if Ada_Version < Ada_2005 then
13004 Error_Msg_N
13005 ("access subtype would not be allowed in generic body "
13006 & "in Ada 2005?y?", S);
13007 else
13008 Error_Msg_N
13009 ("access subtype not allowed in generic body", S);
13010 end if;
13012 Error_Msg_N
13013 ("\designated type is a discriminated formal", S);
13014 end if;
13015 end if;
13016 end Constrain_Access;
13018 ---------------------
13019 -- Constrain_Array --
13020 ---------------------
13022 procedure Constrain_Array
13023 (Def_Id : in out Entity_Id;
13024 SI : Node_Id;
13025 Related_Nod : Node_Id;
13026 Related_Id : Entity_Id;
13027 Suffix : Character)
13029 C : constant Node_Id := Constraint (SI);
13030 Number_Of_Constraints : Nat := 0;
13031 Index : Node_Id;
13032 S, T : Entity_Id;
13033 Constraint_OK : Boolean := True;
13035 begin
13036 T := Entity (Subtype_Mark (SI));
13038 if Is_Access_Type (T) then
13039 T := Designated_Type (T);
13040 end if;
13042 -- If an index constraint follows a subtype mark in a subtype indication
13043 -- then the type or subtype denoted by the subtype mark must not already
13044 -- impose an index constraint. The subtype mark must denote either an
13045 -- unconstrained array type or an access type whose designated type
13046 -- is such an array type... (RM 3.6.1)
13048 if Is_Constrained (T) then
13049 Error_Msg_N ("array type is already constrained", Subtype_Mark (SI));
13050 Constraint_OK := False;
13052 else
13053 S := First (Constraints (C));
13054 while Present (S) loop
13055 Number_Of_Constraints := Number_Of_Constraints + 1;
13056 Next (S);
13057 end loop;
13059 -- In either case, the index constraint must provide a discrete
13060 -- range for each index of the array type and the type of each
13061 -- discrete range must be the same as that of the corresponding
13062 -- index. (RM 3.6.1)
13064 if Number_Of_Constraints /= Number_Dimensions (T) then
13065 Error_Msg_NE ("incorrect number of index constraints for }", C, T);
13066 Constraint_OK := False;
13068 else
13069 S := First (Constraints (C));
13070 Index := First_Index (T);
13071 Analyze (Index);
13073 -- Apply constraints to each index type
13075 for J in 1 .. Number_Of_Constraints loop
13076 Constrain_Index (Index, S, Related_Nod, Related_Id, Suffix, J);
13077 Next (Index);
13078 Next (S);
13079 end loop;
13081 end if;
13082 end if;
13084 if No (Def_Id) then
13085 Def_Id :=
13086 Create_Itype (E_Array_Subtype, Related_Nod, Related_Id, Suffix);
13087 Set_Parent (Def_Id, Related_Nod);
13089 else
13090 Set_Ekind (Def_Id, E_Array_Subtype);
13091 end if;
13093 Set_Size_Info (Def_Id, (T));
13094 Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
13095 Set_Etype (Def_Id, Base_Type (T));
13097 if Constraint_OK then
13098 Set_First_Index (Def_Id, First (Constraints (C)));
13099 else
13100 Set_First_Index (Def_Id, First_Index (T));
13101 end if;
13103 Set_Is_Constrained (Def_Id, True);
13104 Set_Is_Aliased (Def_Id, Is_Aliased (T));
13105 Set_Depends_On_Private (Def_Id, Has_Private_Component (Def_Id));
13107 Set_Is_Private_Composite (Def_Id, Is_Private_Composite (T));
13108 Set_Is_Limited_Composite (Def_Id, Is_Limited_Composite (T));
13110 -- A subtype does not inherit the Packed_Array_Impl_Type of is parent.
13111 -- We need to initialize the attribute because if Def_Id is previously
13112 -- analyzed through a limited_with clause, it will have the attributes
13113 -- of an incomplete type, one of which is an Elist that overlaps the
13114 -- Packed_Array_Impl_Type field.
13116 Set_Packed_Array_Impl_Type (Def_Id, Empty);
13118 -- Build a freeze node if parent still needs one. Also make sure that
13119 -- the Depends_On_Private status is set because the subtype will need
13120 -- reprocessing at the time the base type does, and also we must set a
13121 -- conditional delay.
13123 Set_Depends_On_Private (Def_Id, Depends_On_Private (T));
13124 Conditional_Delay (Def_Id, T);
13125 end Constrain_Array;
13127 ------------------------------
13128 -- Constrain_Component_Type --
13129 ------------------------------
13131 function Constrain_Component_Type
13132 (Comp : Entity_Id;
13133 Constrained_Typ : Entity_Id;
13134 Related_Node : Node_Id;
13135 Typ : Entity_Id;
13136 Constraints : Elist_Id) return Entity_Id
13138 Loc : constant Source_Ptr := Sloc (Constrained_Typ);
13139 Compon_Type : constant Entity_Id := Etype (Comp);
13141 function Build_Constrained_Array_Type
13142 (Old_Type : Entity_Id) return Entity_Id;
13143 -- If Old_Type is an array type, one of whose indexes is constrained
13144 -- by a discriminant, build an Itype whose constraint replaces the
13145 -- discriminant with its value in the constraint.
13147 function Build_Constrained_Discriminated_Type
13148 (Old_Type : Entity_Id) return Entity_Id;
13149 -- Ditto for record components
13151 function Build_Constrained_Access_Type
13152 (Old_Type : Entity_Id) return Entity_Id;
13153 -- Ditto for access types. Makes use of previous two functions, to
13154 -- constrain designated type.
13156 function Build_Subtype (T : Entity_Id; C : List_Id) return Entity_Id;
13157 -- T is an array or discriminated type, C is a list of constraints
13158 -- that apply to T. This routine builds the constrained subtype.
13160 function Is_Discriminant (Expr : Node_Id) return Boolean;
13161 -- Returns True if Expr is a discriminant
13163 function Get_Discr_Value (Discrim : Entity_Id) return Node_Id;
13164 -- Find the value of discriminant Discrim in Constraint
13166 -----------------------------------
13167 -- Build_Constrained_Access_Type --
13168 -----------------------------------
13170 function Build_Constrained_Access_Type
13171 (Old_Type : Entity_Id) return Entity_Id
13173 Desig_Type : constant Entity_Id := Designated_Type (Old_Type);
13174 Itype : Entity_Id;
13175 Desig_Subtype : Entity_Id;
13176 Scop : Entity_Id;
13178 begin
13179 -- if the original access type was not embedded in the enclosing
13180 -- type definition, there is no need to produce a new access
13181 -- subtype. In fact every access type with an explicit constraint
13182 -- generates an itype whose scope is the enclosing record.
13184 if not Is_Type (Scope (Old_Type)) then
13185 return Old_Type;
13187 elsif Is_Array_Type (Desig_Type) then
13188 Desig_Subtype := Build_Constrained_Array_Type (Desig_Type);
13190 elsif Has_Discriminants (Desig_Type) then
13192 -- This may be an access type to an enclosing record type for
13193 -- which we are constructing the constrained components. Return
13194 -- the enclosing record subtype. This is not always correct,
13195 -- but avoids infinite recursion. ???
13197 Desig_Subtype := Any_Type;
13199 for J in reverse 0 .. Scope_Stack.Last loop
13200 Scop := Scope_Stack.Table (J).Entity;
13202 if Is_Type (Scop)
13203 and then Base_Type (Scop) = Base_Type (Desig_Type)
13204 then
13205 Desig_Subtype := Scop;
13206 end if;
13208 exit when not Is_Type (Scop);
13209 end loop;
13211 if Desig_Subtype = Any_Type then
13212 Desig_Subtype :=
13213 Build_Constrained_Discriminated_Type (Desig_Type);
13214 end if;
13216 else
13217 return Old_Type;
13218 end if;
13220 if Desig_Subtype /= Desig_Type then
13222 -- The Related_Node better be here or else we won't be able
13223 -- to attach new itypes to a node in the tree.
13225 pragma Assert (Present (Related_Node));
13227 Itype := Create_Itype (E_Access_Subtype, Related_Node);
13229 Set_Etype (Itype, Base_Type (Old_Type));
13230 Set_Size_Info (Itype, (Old_Type));
13231 Set_Directly_Designated_Type (Itype, Desig_Subtype);
13232 Set_Depends_On_Private (Itype, Has_Private_Component
13233 (Old_Type));
13234 Set_Is_Access_Constant (Itype, Is_Access_Constant
13235 (Old_Type));
13237 -- The new itype needs freezing when it depends on a not frozen
13238 -- type and the enclosing subtype needs freezing.
13240 if Has_Delayed_Freeze (Constrained_Typ)
13241 and then not Is_Frozen (Constrained_Typ)
13242 then
13243 Conditional_Delay (Itype, Base_Type (Old_Type));
13244 end if;
13246 return Itype;
13248 else
13249 return Old_Type;
13250 end if;
13251 end Build_Constrained_Access_Type;
13253 ----------------------------------
13254 -- Build_Constrained_Array_Type --
13255 ----------------------------------
13257 function Build_Constrained_Array_Type
13258 (Old_Type : Entity_Id) return Entity_Id
13260 Lo_Expr : Node_Id;
13261 Hi_Expr : Node_Id;
13262 Old_Index : Node_Id;
13263 Range_Node : Node_Id;
13264 Constr_List : List_Id;
13266 Need_To_Create_Itype : Boolean := False;
13268 begin
13269 Old_Index := First_Index (Old_Type);
13270 while Present (Old_Index) loop
13271 Get_Index_Bounds (Old_Index, Lo_Expr, Hi_Expr);
13273 if Is_Discriminant (Lo_Expr)
13274 or else
13275 Is_Discriminant (Hi_Expr)
13276 then
13277 Need_To_Create_Itype := True;
13278 end if;
13280 Next_Index (Old_Index);
13281 end loop;
13283 if Need_To_Create_Itype then
13284 Constr_List := New_List;
13286 Old_Index := First_Index (Old_Type);
13287 while Present (Old_Index) loop
13288 Get_Index_Bounds (Old_Index, Lo_Expr, Hi_Expr);
13290 if Is_Discriminant (Lo_Expr) then
13291 Lo_Expr := Get_Discr_Value (Lo_Expr);
13292 end if;
13294 if Is_Discriminant (Hi_Expr) then
13295 Hi_Expr := Get_Discr_Value (Hi_Expr);
13296 end if;
13298 Range_Node :=
13299 Make_Range
13300 (Loc, New_Copy_Tree (Lo_Expr), New_Copy_Tree (Hi_Expr));
13302 Append (Range_Node, To => Constr_List);
13304 Next_Index (Old_Index);
13305 end loop;
13307 return Build_Subtype (Old_Type, Constr_List);
13309 else
13310 return Old_Type;
13311 end if;
13312 end Build_Constrained_Array_Type;
13314 ------------------------------------------
13315 -- Build_Constrained_Discriminated_Type --
13316 ------------------------------------------
13318 function Build_Constrained_Discriminated_Type
13319 (Old_Type : Entity_Id) return Entity_Id
13321 Expr : Node_Id;
13322 Constr_List : List_Id;
13323 Old_Constraint : Elmt_Id;
13325 Need_To_Create_Itype : Boolean := False;
13327 begin
13328 Old_Constraint := First_Elmt (Discriminant_Constraint (Old_Type));
13329 while Present (Old_Constraint) loop
13330 Expr := Node (Old_Constraint);
13332 if Is_Discriminant (Expr) then
13333 Need_To_Create_Itype := True;
13334 end if;
13336 Next_Elmt (Old_Constraint);
13337 end loop;
13339 if Need_To_Create_Itype then
13340 Constr_List := New_List;
13342 Old_Constraint := First_Elmt (Discriminant_Constraint (Old_Type));
13343 while Present (Old_Constraint) loop
13344 Expr := Node (Old_Constraint);
13346 if Is_Discriminant (Expr) then
13347 Expr := Get_Discr_Value (Expr);
13348 end if;
13350 Append (New_Copy_Tree (Expr), To => Constr_List);
13352 Next_Elmt (Old_Constraint);
13353 end loop;
13355 return Build_Subtype (Old_Type, Constr_List);
13357 else
13358 return Old_Type;
13359 end if;
13360 end Build_Constrained_Discriminated_Type;
13362 -------------------
13363 -- Build_Subtype --
13364 -------------------
13366 function Build_Subtype (T : Entity_Id; C : List_Id) return Entity_Id is
13367 Indic : Node_Id;
13368 Subtyp_Decl : Node_Id;
13369 Def_Id : Entity_Id;
13370 Btyp : Entity_Id := Base_Type (T);
13372 begin
13373 -- The Related_Node better be here or else we won't be able to
13374 -- attach new itypes to a node in the tree.
13376 pragma Assert (Present (Related_Node));
13378 -- If the view of the component's type is incomplete or private
13379 -- with unknown discriminants, then the constraint must be applied
13380 -- to the full type.
13382 if Has_Unknown_Discriminants (Btyp)
13383 and then Present (Underlying_Type (Btyp))
13384 then
13385 Btyp := Underlying_Type (Btyp);
13386 end if;
13388 Indic :=
13389 Make_Subtype_Indication (Loc,
13390 Subtype_Mark => New_Occurrence_Of (Btyp, Loc),
13391 Constraint => Make_Index_Or_Discriminant_Constraint (Loc, C));
13393 Def_Id := Create_Itype (Ekind (T), Related_Node);
13395 Subtyp_Decl :=
13396 Make_Subtype_Declaration (Loc,
13397 Defining_Identifier => Def_Id,
13398 Subtype_Indication => Indic);
13400 Set_Parent (Subtyp_Decl, Parent (Related_Node));
13402 -- Itypes must be analyzed with checks off (see package Itypes)
13404 Analyze (Subtyp_Decl, Suppress => All_Checks);
13406 return Def_Id;
13407 end Build_Subtype;
13409 ---------------------
13410 -- Get_Discr_Value --
13411 ---------------------
13413 function Get_Discr_Value (Discrim : Entity_Id) return Node_Id is
13414 D : Entity_Id;
13415 E : Elmt_Id;
13417 begin
13418 -- The discriminant may be declared for the type, in which case we
13419 -- find it by iterating over the list of discriminants. If the
13420 -- discriminant is inherited from a parent type, it appears as the
13421 -- corresponding discriminant of the current type. This will be the
13422 -- case when constraining an inherited component whose constraint is
13423 -- given by a discriminant of the parent.
13425 D := First_Discriminant (Typ);
13426 E := First_Elmt (Constraints);
13428 while Present (D) loop
13429 if D = Entity (Discrim)
13430 or else D = CR_Discriminant (Entity (Discrim))
13431 or else Corresponding_Discriminant (D) = Entity (Discrim)
13432 then
13433 return Node (E);
13434 end if;
13436 Next_Discriminant (D);
13437 Next_Elmt (E);
13438 end loop;
13440 -- The Corresponding_Discriminant mechanism is incomplete, because
13441 -- the correspondence between new and old discriminants is not one
13442 -- to one: one new discriminant can constrain several old ones. In
13443 -- that case, scan sequentially the stored_constraint, the list of
13444 -- discriminants of the parents, and the constraints.
13446 -- Previous code checked for the present of the Stored_Constraint
13447 -- list for the derived type, but did not use it at all. Should it
13448 -- be present when the component is a discriminated task type?
13450 if Is_Derived_Type (Typ)
13451 and then Scope (Entity (Discrim)) = Etype (Typ)
13452 then
13453 D := First_Discriminant (Etype (Typ));
13454 E := First_Elmt (Constraints);
13455 while Present (D) loop
13456 if D = Entity (Discrim) then
13457 return Node (E);
13458 end if;
13460 Next_Discriminant (D);
13461 Next_Elmt (E);
13462 end loop;
13463 end if;
13465 -- Something is wrong if we did not find the value
13467 raise Program_Error;
13468 end Get_Discr_Value;
13470 ---------------------
13471 -- Is_Discriminant --
13472 ---------------------
13474 function Is_Discriminant (Expr : Node_Id) return Boolean is
13475 Discrim_Scope : Entity_Id;
13477 begin
13478 if Denotes_Discriminant (Expr) then
13479 Discrim_Scope := Scope (Entity (Expr));
13481 -- Either we have a reference to one of Typ's discriminants,
13483 pragma Assert (Discrim_Scope = Typ
13485 -- or to the discriminants of the parent type, in the case
13486 -- of a derivation of a tagged type with variants.
13488 or else Discrim_Scope = Etype (Typ)
13489 or else Full_View (Discrim_Scope) = Etype (Typ)
13491 -- or same as above for the case where the discriminants
13492 -- were declared in Typ's private view.
13494 or else (Is_Private_Type (Discrim_Scope)
13495 and then Chars (Discrim_Scope) = Chars (Typ))
13497 -- or else we are deriving from the full view and the
13498 -- discriminant is declared in the private entity.
13500 or else (Is_Private_Type (Typ)
13501 and then Chars (Discrim_Scope) = Chars (Typ))
13503 -- Or we are constrained the corresponding record of a
13504 -- synchronized type that completes a private declaration.
13506 or else (Is_Concurrent_Record_Type (Typ)
13507 and then
13508 Corresponding_Concurrent_Type (Typ) = Discrim_Scope)
13510 -- or we have a class-wide type, in which case make sure the
13511 -- discriminant found belongs to the root type.
13513 or else (Is_Class_Wide_Type (Typ)
13514 and then Etype (Typ) = Discrim_Scope));
13516 return True;
13517 end if;
13519 -- In all other cases we have something wrong
13521 return False;
13522 end Is_Discriminant;
13524 -- Start of processing for Constrain_Component_Type
13526 begin
13527 if Nkind (Parent (Comp)) = N_Component_Declaration
13528 and then Comes_From_Source (Parent (Comp))
13529 and then Comes_From_Source
13530 (Subtype_Indication (Component_Definition (Parent (Comp))))
13531 and then
13532 Is_Entity_Name
13533 (Subtype_Indication (Component_Definition (Parent (Comp))))
13534 then
13535 return Compon_Type;
13537 elsif Is_Array_Type (Compon_Type) then
13538 return Build_Constrained_Array_Type (Compon_Type);
13540 elsif Has_Discriminants (Compon_Type) then
13541 return Build_Constrained_Discriminated_Type (Compon_Type);
13543 elsif Is_Access_Type (Compon_Type) then
13544 return Build_Constrained_Access_Type (Compon_Type);
13546 else
13547 return Compon_Type;
13548 end if;
13549 end Constrain_Component_Type;
13551 --------------------------
13552 -- Constrain_Concurrent --
13553 --------------------------
13555 -- For concurrent types, the associated record value type carries the same
13556 -- discriminants, so when we constrain a concurrent type, we must constrain
13557 -- the corresponding record type as well.
13559 procedure Constrain_Concurrent
13560 (Def_Id : in out Entity_Id;
13561 SI : Node_Id;
13562 Related_Nod : Node_Id;
13563 Related_Id : Entity_Id;
13564 Suffix : Character)
13566 -- Retrieve Base_Type to ensure getting to the concurrent type in the
13567 -- case of a private subtype (needed when only doing semantic analysis).
13569 T_Ent : Entity_Id := Base_Type (Entity (Subtype_Mark (SI)));
13570 T_Val : Entity_Id;
13572 begin
13573 if Is_Access_Type (T_Ent) then
13574 T_Ent := Designated_Type (T_Ent);
13575 end if;
13577 T_Val := Corresponding_Record_Type (T_Ent);
13579 if Present (T_Val) then
13581 if No (Def_Id) then
13582 Def_Id := Create_Itype (E_Void, Related_Nod, Related_Id, Suffix);
13584 -- Elaborate itype now, as it may be used in a subsequent
13585 -- synchronized operation in another scope.
13587 if Nkind (Related_Nod) = N_Full_Type_Declaration then
13588 Build_Itype_Reference (Def_Id, Related_Nod);
13589 end if;
13590 end if;
13592 Constrain_Discriminated_Type (Def_Id, SI, Related_Nod);
13593 Set_First_Private_Entity (Def_Id, First_Private_Entity (T_Ent));
13595 Set_Depends_On_Private (Def_Id, Has_Private_Component (Def_Id));
13596 Set_Corresponding_Record_Type (Def_Id,
13597 Constrain_Corresponding_Record (Def_Id, T_Val, Related_Nod));
13599 else
13600 -- If there is no associated record, expansion is disabled and this
13601 -- is a generic context. Create a subtype in any case, so that
13602 -- semantic analysis can proceed.
13604 if No (Def_Id) then
13605 Def_Id := Create_Itype (E_Void, Related_Nod, Related_Id, Suffix);
13606 end if;
13608 Constrain_Discriminated_Type (Def_Id, SI, Related_Nod);
13609 end if;
13610 end Constrain_Concurrent;
13612 ------------------------------------
13613 -- Constrain_Corresponding_Record --
13614 ------------------------------------
13616 function Constrain_Corresponding_Record
13617 (Prot_Subt : Entity_Id;
13618 Corr_Rec : Entity_Id;
13619 Related_Nod : Node_Id) return Entity_Id
13621 T_Sub : constant Entity_Id :=
13622 Create_Itype (E_Record_Subtype, Related_Nod, Corr_Rec, 'C');
13624 begin
13625 Set_Etype (T_Sub, Corr_Rec);
13626 Set_Has_Discriminants (T_Sub, Has_Discriminants (Prot_Subt));
13627 Set_Is_Constrained (T_Sub, True);
13628 Set_First_Entity (T_Sub, First_Entity (Corr_Rec));
13629 Set_Last_Entity (T_Sub, Last_Entity (Corr_Rec));
13631 if Has_Discriminants (Prot_Subt) then -- False only if errors.
13632 Set_Discriminant_Constraint
13633 (T_Sub, Discriminant_Constraint (Prot_Subt));
13634 Set_Stored_Constraint_From_Discriminant_Constraint (T_Sub);
13635 Create_Constrained_Components
13636 (T_Sub, Related_Nod, Corr_Rec, Discriminant_Constraint (T_Sub));
13637 end if;
13639 Set_Depends_On_Private (T_Sub, Has_Private_Component (T_Sub));
13641 if Ekind (Scope (Prot_Subt)) /= E_Record_Type then
13642 Conditional_Delay (T_Sub, Corr_Rec);
13644 else
13645 -- This is a component subtype: it will be frozen in the context of
13646 -- the enclosing record's init_proc, so that discriminant references
13647 -- are resolved to discriminals. (Note: we used to skip freezing
13648 -- altogether in that case, which caused errors downstream for
13649 -- components of a bit packed array type).
13651 Set_Has_Delayed_Freeze (T_Sub);
13652 end if;
13654 return T_Sub;
13655 end Constrain_Corresponding_Record;
13657 -----------------------
13658 -- Constrain_Decimal --
13659 -----------------------
13661 procedure Constrain_Decimal (Def_Id : Node_Id; S : Node_Id) is
13662 T : constant Entity_Id := Entity (Subtype_Mark (S));
13663 C : constant Node_Id := Constraint (S);
13664 Loc : constant Source_Ptr := Sloc (C);
13665 Range_Expr : Node_Id;
13666 Digits_Expr : Node_Id;
13667 Digits_Val : Uint;
13668 Bound_Val : Ureal;
13670 begin
13671 Set_Ekind (Def_Id, E_Decimal_Fixed_Point_Subtype);
13673 if Nkind (C) = N_Range_Constraint then
13674 Range_Expr := Range_Expression (C);
13675 Digits_Val := Digits_Value (T);
13677 else
13678 pragma Assert (Nkind (C) = N_Digits_Constraint);
13680 Check_SPARK_05_Restriction ("digits constraint is not allowed", S);
13682 Digits_Expr := Digits_Expression (C);
13683 Analyze_And_Resolve (Digits_Expr, Any_Integer);
13685 Check_Digits_Expression (Digits_Expr);
13686 Digits_Val := Expr_Value (Digits_Expr);
13688 if Digits_Val > Digits_Value (T) then
13689 Error_Msg_N
13690 ("digits expression is incompatible with subtype", C);
13691 Digits_Val := Digits_Value (T);
13692 end if;
13694 if Present (Range_Constraint (C)) then
13695 Range_Expr := Range_Expression (Range_Constraint (C));
13696 else
13697 Range_Expr := Empty;
13698 end if;
13699 end if;
13701 Set_Etype (Def_Id, Base_Type (T));
13702 Set_Size_Info (Def_Id, (T));
13703 Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
13704 Set_Delta_Value (Def_Id, Delta_Value (T));
13705 Set_Scale_Value (Def_Id, Scale_Value (T));
13706 Set_Small_Value (Def_Id, Small_Value (T));
13707 Set_Machine_Radix_10 (Def_Id, Machine_Radix_10 (T));
13708 Set_Digits_Value (Def_Id, Digits_Val);
13710 -- Manufacture range from given digits value if no range present
13712 if No (Range_Expr) then
13713 Bound_Val := (Ureal_10 ** Digits_Val - Ureal_1) * Small_Value (T);
13714 Range_Expr :=
13715 Make_Range (Loc,
13716 Low_Bound =>
13717 Convert_To (T, Make_Real_Literal (Loc, (-Bound_Val))),
13718 High_Bound =>
13719 Convert_To (T, Make_Real_Literal (Loc, Bound_Val)));
13720 end if;
13722 Set_Scalar_Range_For_Subtype (Def_Id, Range_Expr, T);
13723 Set_Discrete_RM_Size (Def_Id);
13725 -- Unconditionally delay the freeze, since we cannot set size
13726 -- information in all cases correctly until the freeze point.
13728 Set_Has_Delayed_Freeze (Def_Id);
13729 end Constrain_Decimal;
13731 ----------------------------------
13732 -- Constrain_Discriminated_Type --
13733 ----------------------------------
13735 procedure Constrain_Discriminated_Type
13736 (Def_Id : Entity_Id;
13737 S : Node_Id;
13738 Related_Nod : Node_Id;
13739 For_Access : Boolean := False)
13741 E : Entity_Id := Entity (Subtype_Mark (S));
13742 T : Entity_Id;
13744 procedure Fixup_Bad_Constraint;
13745 -- Called after finding a bad constraint, and after having posted an
13746 -- appropriate error message. The goal is to leave type Def_Id in as
13747 -- reasonable state as possible.
13749 --------------------------
13750 -- Fixup_Bad_Constraint --
13751 --------------------------
13753 procedure Fixup_Bad_Constraint is
13754 begin
13755 -- Set a reasonable Ekind for the entity, including incomplete types.
13757 Set_Ekind (Def_Id, Subtype_Kind (Ekind (T)));
13759 -- Set Etype to the known type, to reduce chances of cascaded errors
13761 Set_Etype (Def_Id, E);
13762 Set_Error_Posted (Def_Id);
13763 end Fixup_Bad_Constraint;
13765 -- Local variables
13767 C : Node_Id;
13768 Constr : Elist_Id := New_Elmt_List;
13770 -- Start of processing for Constrain_Discriminated_Type
13772 begin
13773 C := Constraint (S);
13775 -- A discriminant constraint is only allowed in a subtype indication,
13776 -- after a subtype mark. This subtype mark must denote either a type
13777 -- with discriminants, or an access type whose designated type is a
13778 -- type with discriminants. A discriminant constraint specifies the
13779 -- values of these discriminants (RM 3.7.2(5)).
13781 T := Base_Type (Entity (Subtype_Mark (S)));
13783 if Is_Access_Type (T) then
13784 T := Designated_Type (T);
13785 end if;
13787 -- In an instance it may be necessary to retrieve the full view of a
13788 -- type with unknown discriminants, or a full view with defaulted
13789 -- discriminants. In other contexts the constraint is illegal.
13791 if In_Instance
13792 and then Is_Private_Type (T)
13793 and then Present (Full_View (T))
13794 and then
13795 (Has_Unknown_Discriminants (T)
13796 or else
13797 (not Has_Discriminants (T)
13798 and then Has_Discriminants (Full_View (T))
13799 and then Present (Discriminant_Default_Value
13800 (First_Discriminant (Full_View (T))))))
13801 then
13802 T := Full_View (T);
13803 E := Full_View (E);
13804 end if;
13806 -- Ada 2005 (AI-412): Constrained incomplete subtypes are illegal. Avoid
13807 -- generating an error for access-to-incomplete subtypes.
13809 if Ada_Version >= Ada_2005
13810 and then Ekind (T) = E_Incomplete_Type
13811 and then Nkind (Parent (S)) = N_Subtype_Declaration
13812 and then not Is_Itype (Def_Id)
13813 then
13814 -- A little sanity check: emit an error message if the type has
13815 -- discriminants to begin with. Type T may be a regular incomplete
13816 -- type or imported via a limited with clause.
13818 if Has_Discriminants (T)
13819 or else (From_Limited_With (T)
13820 and then Present (Non_Limited_View (T))
13821 and then Nkind (Parent (Non_Limited_View (T))) =
13822 N_Full_Type_Declaration
13823 and then Present (Discriminant_Specifications
13824 (Parent (Non_Limited_View (T)))))
13825 then
13826 Error_Msg_N
13827 ("(Ada 2005) incomplete subtype may not be constrained", C);
13828 else
13829 Error_Msg_N ("invalid constraint: type has no discriminant", C);
13830 end if;
13832 Fixup_Bad_Constraint;
13833 return;
13835 -- Check that the type has visible discriminants. The type may be
13836 -- a private type with unknown discriminants whose full view has
13837 -- discriminants which are invisible.
13839 elsif not Has_Discriminants (T)
13840 or else
13841 (Has_Unknown_Discriminants (T)
13842 and then Is_Private_Type (T))
13843 then
13844 Error_Msg_N ("invalid constraint: type has no discriminant", C);
13845 Fixup_Bad_Constraint;
13846 return;
13848 elsif Is_Constrained (E)
13849 or else (Ekind (E) = E_Class_Wide_Subtype
13850 and then Present (Discriminant_Constraint (E)))
13851 then
13852 Error_Msg_N ("type is already constrained", Subtype_Mark (S));
13853 Fixup_Bad_Constraint;
13854 return;
13855 end if;
13857 -- T may be an unconstrained subtype (e.g. a generic actual). Constraint
13858 -- applies to the base type.
13860 T := Base_Type (T);
13862 Constr := Build_Discriminant_Constraints (T, S);
13864 -- If the list returned was empty we had an error in building the
13865 -- discriminant constraint. We have also already signalled an error
13866 -- in the incomplete type case
13868 if Is_Empty_Elmt_List (Constr) then
13869 Fixup_Bad_Constraint;
13870 return;
13871 end if;
13873 Build_Discriminated_Subtype (T, Def_Id, Constr, Related_Nod, For_Access);
13874 end Constrain_Discriminated_Type;
13876 ---------------------------
13877 -- Constrain_Enumeration --
13878 ---------------------------
13880 procedure Constrain_Enumeration (Def_Id : Node_Id; S : Node_Id) is
13881 T : constant Entity_Id := Entity (Subtype_Mark (S));
13882 C : constant Node_Id := Constraint (S);
13884 begin
13885 Set_Ekind (Def_Id, E_Enumeration_Subtype);
13887 Set_First_Literal (Def_Id, First_Literal (Base_Type (T)));
13889 Set_Etype (Def_Id, Base_Type (T));
13890 Set_Size_Info (Def_Id, (T));
13891 Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
13892 Set_Is_Character_Type (Def_Id, Is_Character_Type (T));
13894 Set_Scalar_Range_For_Subtype (Def_Id, Range_Expression (C), T);
13896 Set_Discrete_RM_Size (Def_Id);
13897 end Constrain_Enumeration;
13899 ----------------------
13900 -- Constrain_Float --
13901 ----------------------
13903 procedure Constrain_Float (Def_Id : Node_Id; S : Node_Id) is
13904 T : constant Entity_Id := Entity (Subtype_Mark (S));
13905 C : Node_Id;
13906 D : Node_Id;
13907 Rais : Node_Id;
13909 begin
13910 Set_Ekind (Def_Id, E_Floating_Point_Subtype);
13912 Set_Etype (Def_Id, Base_Type (T));
13913 Set_Size_Info (Def_Id, (T));
13914 Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
13916 -- Process the constraint
13918 C := Constraint (S);
13920 -- Digits constraint present
13922 if Nkind (C) = N_Digits_Constraint then
13924 Check_SPARK_05_Restriction ("digits constraint is not allowed", S);
13925 Check_Restriction (No_Obsolescent_Features, C);
13927 if Warn_On_Obsolescent_Feature then
13928 Error_Msg_N
13929 ("subtype digits constraint is an " &
13930 "obsolescent feature (RM J.3(8))?j?", C);
13931 end if;
13933 D := Digits_Expression (C);
13934 Analyze_And_Resolve (D, Any_Integer);
13935 Check_Digits_Expression (D);
13936 Set_Digits_Value (Def_Id, Expr_Value (D));
13938 -- Check that digits value is in range. Obviously we can do this
13939 -- at compile time, but it is strictly a runtime check, and of
13940 -- course there is an ACVC test that checks this.
13942 if Digits_Value (Def_Id) > Digits_Value (T) then
13943 Error_Msg_Uint_1 := Digits_Value (T);
13944 Error_Msg_N ("??digits value is too large, maximum is ^", D);
13945 Rais :=
13946 Make_Raise_Constraint_Error (Sloc (D),
13947 Reason => CE_Range_Check_Failed);
13948 Insert_Action (Declaration_Node (Def_Id), Rais);
13949 end if;
13951 C := Range_Constraint (C);
13953 -- No digits constraint present
13955 else
13956 Set_Digits_Value (Def_Id, Digits_Value (T));
13957 end if;
13959 -- Range constraint present
13961 if Nkind (C) = N_Range_Constraint then
13962 Set_Scalar_Range_For_Subtype (Def_Id, Range_Expression (C), T);
13964 -- No range constraint present
13966 else
13967 pragma Assert (No (C));
13968 Set_Scalar_Range (Def_Id, Scalar_Range (T));
13969 end if;
13971 Set_Is_Constrained (Def_Id);
13972 end Constrain_Float;
13974 ---------------------
13975 -- Constrain_Index --
13976 ---------------------
13978 procedure Constrain_Index
13979 (Index : Node_Id;
13980 S : Node_Id;
13981 Related_Nod : Node_Id;
13982 Related_Id : Entity_Id;
13983 Suffix : Character;
13984 Suffix_Index : Nat)
13986 Def_Id : Entity_Id;
13987 R : Node_Id := Empty;
13988 T : constant Entity_Id := Etype (Index);
13990 begin
13991 Def_Id :=
13992 Create_Itype (E_Void, Related_Nod, Related_Id, Suffix, Suffix_Index);
13993 Set_Etype (Def_Id, Base_Type (T));
13995 if Nkind (S) = N_Range
13996 or else
13997 (Nkind (S) = N_Attribute_Reference
13998 and then Attribute_Name (S) = Name_Range)
13999 then
14000 -- A Range attribute will be transformed into N_Range by Resolve
14002 Analyze (S);
14003 Set_Etype (S, T);
14004 R := S;
14006 Process_Range_Expr_In_Decl (R, T);
14008 if not Error_Posted (S)
14009 and then
14010 (Nkind (S) /= N_Range
14011 or else not Covers (T, (Etype (Low_Bound (S))))
14012 or else not Covers (T, (Etype (High_Bound (S)))))
14013 then
14014 if Base_Type (T) /= Any_Type
14015 and then Etype (Low_Bound (S)) /= Any_Type
14016 and then Etype (High_Bound (S)) /= Any_Type
14017 then
14018 Error_Msg_N ("range expected", S);
14019 end if;
14020 end if;
14022 elsif Nkind (S) = N_Subtype_Indication then
14024 -- The parser has verified that this is a discrete indication
14026 Resolve_Discrete_Subtype_Indication (S, T);
14027 Bad_Predicated_Subtype_Use
14028 ("subtype& has predicate, not allowed in index constraint",
14029 S, Entity (Subtype_Mark (S)));
14031 R := Range_Expression (Constraint (S));
14033 -- Capture values of bounds and generate temporaries for them if
14034 -- needed, since checks may cause duplication of the expressions
14035 -- which must not be reevaluated.
14037 -- The forced evaluation removes side effects from expressions, which
14038 -- should occur also in GNATprove mode. Otherwise, we end up with
14039 -- unexpected insertions of actions at places where this is not
14040 -- supposed to occur, e.g. on default parameters of a call.
14042 if Expander_Active or GNATprove_Mode then
14043 Force_Evaluation
14044 (Low_Bound (R), Related_Id => Def_Id, Is_Low_Bound => True);
14045 Force_Evaluation
14046 (High_Bound (R), Related_Id => Def_Id, Is_High_Bound => True);
14047 end if;
14049 elsif Nkind (S) = N_Discriminant_Association then
14051 -- Syntactically valid in subtype indication
14053 Error_Msg_N ("invalid index constraint", S);
14054 Rewrite (S, New_Occurrence_Of (T, Sloc (S)));
14055 return;
14057 -- Subtype_Mark case, no anonymous subtypes to construct
14059 else
14060 Analyze (S);
14062 if Is_Entity_Name (S) then
14063 if not Is_Type (Entity (S)) then
14064 Error_Msg_N ("expect subtype mark for index constraint", S);
14066 elsif Base_Type (Entity (S)) /= Base_Type (T) then
14067 Wrong_Type (S, Base_Type (T));
14069 -- Check error of subtype with predicate in index constraint
14071 else
14072 Bad_Predicated_Subtype_Use
14073 ("subtype& has predicate, not allowed in index constraint",
14074 S, Entity (S));
14075 end if;
14077 return;
14079 else
14080 Error_Msg_N ("invalid index constraint", S);
14081 Rewrite (S, New_Occurrence_Of (T, Sloc (S)));
14082 return;
14083 end if;
14084 end if;
14086 -- Complete construction of the Itype
14088 if Is_Modular_Integer_Type (T) then
14089 Set_Ekind (Def_Id, E_Modular_Integer_Subtype);
14091 elsif Is_Integer_Type (T) then
14092 Set_Ekind (Def_Id, E_Signed_Integer_Subtype);
14094 else
14095 Set_Ekind (Def_Id, E_Enumeration_Subtype);
14096 Set_Is_Character_Type (Def_Id, Is_Character_Type (T));
14097 Set_First_Literal (Def_Id, First_Literal (T));
14098 end if;
14100 Set_Size_Info (Def_Id, (T));
14101 Set_RM_Size (Def_Id, RM_Size (T));
14102 Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
14104 Set_Scalar_Range (Def_Id, R);
14106 Set_Etype (S, Def_Id);
14107 Set_Discrete_RM_Size (Def_Id);
14108 end Constrain_Index;
14110 -----------------------
14111 -- Constrain_Integer --
14112 -----------------------
14114 procedure Constrain_Integer (Def_Id : Node_Id; S : Node_Id) is
14115 T : constant Entity_Id := Entity (Subtype_Mark (S));
14116 C : constant Node_Id := Constraint (S);
14118 begin
14119 Set_Scalar_Range_For_Subtype (Def_Id, Range_Expression (C), T);
14121 if Is_Modular_Integer_Type (T) then
14122 Set_Ekind (Def_Id, E_Modular_Integer_Subtype);
14123 else
14124 Set_Ekind (Def_Id, E_Signed_Integer_Subtype);
14125 end if;
14127 Set_Etype (Def_Id, Base_Type (T));
14128 Set_Size_Info (Def_Id, (T));
14129 Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
14130 Set_Discrete_RM_Size (Def_Id);
14131 end Constrain_Integer;
14133 ------------------------------
14134 -- Constrain_Ordinary_Fixed --
14135 ------------------------------
14137 procedure Constrain_Ordinary_Fixed (Def_Id : Node_Id; S : Node_Id) is
14138 T : constant Entity_Id := Entity (Subtype_Mark (S));
14139 C : Node_Id;
14140 D : Node_Id;
14141 Rais : Node_Id;
14143 begin
14144 Set_Ekind (Def_Id, E_Ordinary_Fixed_Point_Subtype);
14145 Set_Etype (Def_Id, Base_Type (T));
14146 Set_Size_Info (Def_Id, (T));
14147 Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
14148 Set_Small_Value (Def_Id, Small_Value (T));
14150 -- Process the constraint
14152 C := Constraint (S);
14154 -- Delta constraint present
14156 if Nkind (C) = N_Delta_Constraint then
14158 Check_SPARK_05_Restriction ("delta constraint is not allowed", S);
14159 Check_Restriction (No_Obsolescent_Features, C);
14161 if Warn_On_Obsolescent_Feature then
14162 Error_Msg_S
14163 ("subtype delta constraint is an " &
14164 "obsolescent feature (RM J.3(7))?j?");
14165 end if;
14167 D := Delta_Expression (C);
14168 Analyze_And_Resolve (D, Any_Real);
14169 Check_Delta_Expression (D);
14170 Set_Delta_Value (Def_Id, Expr_Value_R (D));
14172 -- Check that delta value is in range. Obviously we can do this
14173 -- at compile time, but it is strictly a runtime check, and of
14174 -- course there is an ACVC test that checks this.
14176 if Delta_Value (Def_Id) < Delta_Value (T) then
14177 Error_Msg_N ("??delta value is too small", D);
14178 Rais :=
14179 Make_Raise_Constraint_Error (Sloc (D),
14180 Reason => CE_Range_Check_Failed);
14181 Insert_Action (Declaration_Node (Def_Id), Rais);
14182 end if;
14184 C := Range_Constraint (C);
14186 -- No delta constraint present
14188 else
14189 Set_Delta_Value (Def_Id, Delta_Value (T));
14190 end if;
14192 -- Range constraint present
14194 if Nkind (C) = N_Range_Constraint then
14195 Set_Scalar_Range_For_Subtype (Def_Id, Range_Expression (C), T);
14197 -- No range constraint present
14199 else
14200 pragma Assert (No (C));
14201 Set_Scalar_Range (Def_Id, Scalar_Range (T));
14202 end if;
14204 Set_Discrete_RM_Size (Def_Id);
14206 -- Unconditionally delay the freeze, since we cannot set size
14207 -- information in all cases correctly until the freeze point.
14209 Set_Has_Delayed_Freeze (Def_Id);
14210 end Constrain_Ordinary_Fixed;
14212 -----------------------
14213 -- Contain_Interface --
14214 -----------------------
14216 function Contain_Interface
14217 (Iface : Entity_Id;
14218 Ifaces : Elist_Id) return Boolean
14220 Iface_Elmt : Elmt_Id;
14222 begin
14223 if Present (Ifaces) then
14224 Iface_Elmt := First_Elmt (Ifaces);
14225 while Present (Iface_Elmt) loop
14226 if Node (Iface_Elmt) = Iface then
14227 return True;
14228 end if;
14230 Next_Elmt (Iface_Elmt);
14231 end loop;
14232 end if;
14234 return False;
14235 end Contain_Interface;
14237 ---------------------------
14238 -- Convert_Scalar_Bounds --
14239 ---------------------------
14241 procedure Convert_Scalar_Bounds
14242 (N : Node_Id;
14243 Parent_Type : Entity_Id;
14244 Derived_Type : Entity_Id;
14245 Loc : Source_Ptr)
14247 Implicit_Base : constant Entity_Id := Base_Type (Derived_Type);
14249 Lo : Node_Id;
14250 Hi : Node_Id;
14251 Rng : Node_Id;
14253 begin
14254 -- Defend against previous errors
14256 if No (Scalar_Range (Derived_Type)) then
14257 Check_Error_Detected;
14258 return;
14259 end if;
14261 Lo := Build_Scalar_Bound
14262 (Type_Low_Bound (Derived_Type),
14263 Parent_Type, Implicit_Base);
14265 Hi := Build_Scalar_Bound
14266 (Type_High_Bound (Derived_Type),
14267 Parent_Type, Implicit_Base);
14269 Rng :=
14270 Make_Range (Loc,
14271 Low_Bound => Lo,
14272 High_Bound => Hi);
14274 Set_Includes_Infinities (Rng, Has_Infinities (Derived_Type));
14276 Set_Parent (Rng, N);
14277 Set_Scalar_Range (Derived_Type, Rng);
14279 -- Analyze the bounds
14281 Analyze_And_Resolve (Lo, Implicit_Base);
14282 Analyze_And_Resolve (Hi, Implicit_Base);
14284 -- Analyze the range itself, except that we do not analyze it if
14285 -- the bounds are real literals, and we have a fixed-point type.
14286 -- The reason for this is that we delay setting the bounds in this
14287 -- case till we know the final Small and Size values (see circuit
14288 -- in Freeze.Freeze_Fixed_Point_Type for further details).
14290 if Is_Fixed_Point_Type (Parent_Type)
14291 and then Nkind (Lo) = N_Real_Literal
14292 and then Nkind (Hi) = N_Real_Literal
14293 then
14294 return;
14296 -- Here we do the analysis of the range
14298 -- Note: we do this manually, since if we do a normal Analyze and
14299 -- Resolve call, there are problems with the conversions used for
14300 -- the derived type range.
14302 else
14303 Set_Etype (Rng, Implicit_Base);
14304 Set_Analyzed (Rng, True);
14305 end if;
14306 end Convert_Scalar_Bounds;
14308 -------------------
14309 -- Copy_And_Swap --
14310 -------------------
14312 procedure Copy_And_Swap (Priv, Full : Entity_Id) is
14313 begin
14314 -- Initialize new full declaration entity by copying the pertinent
14315 -- fields of the corresponding private declaration entity.
14317 -- We temporarily set Ekind to a value appropriate for a type to
14318 -- avoid assert failures in Einfo from checking for setting type
14319 -- attributes on something that is not a type. Ekind (Priv) is an
14320 -- appropriate choice, since it allowed the attributes to be set
14321 -- in the first place. This Ekind value will be modified later.
14323 Set_Ekind (Full, Ekind (Priv));
14325 -- Also set Etype temporarily to Any_Type, again, in the absence
14326 -- of errors, it will be properly reset, and if there are errors,
14327 -- then we want a value of Any_Type to remain.
14329 Set_Etype (Full, Any_Type);
14331 -- Now start copying attributes
14333 Set_Has_Discriminants (Full, Has_Discriminants (Priv));
14335 if Has_Discriminants (Full) then
14336 Set_Discriminant_Constraint (Full, Discriminant_Constraint (Priv));
14337 Set_Stored_Constraint (Full, Stored_Constraint (Priv));
14338 end if;
14340 Set_First_Rep_Item (Full, First_Rep_Item (Priv));
14341 Set_Homonym (Full, Homonym (Priv));
14342 Set_Is_Immediately_Visible (Full, Is_Immediately_Visible (Priv));
14343 Set_Is_Public (Full, Is_Public (Priv));
14344 Set_Is_Pure (Full, Is_Pure (Priv));
14345 Set_Is_Tagged_Type (Full, Is_Tagged_Type (Priv));
14346 Set_Has_Pragma_Unmodified (Full, Has_Pragma_Unmodified (Priv));
14347 Set_Has_Pragma_Unreferenced (Full, Has_Pragma_Unreferenced (Priv));
14348 Set_Has_Pragma_Unreferenced_Objects
14349 (Full, Has_Pragma_Unreferenced_Objects
14350 (Priv));
14352 Conditional_Delay (Full, Priv);
14354 if Is_Tagged_Type (Full) then
14355 Set_Direct_Primitive_Operations
14356 (Full, Direct_Primitive_Operations (Priv));
14357 Set_No_Tagged_Streams_Pragma
14358 (Full, No_Tagged_Streams_Pragma (Priv));
14360 if Is_Base_Type (Priv) then
14361 Set_Class_Wide_Type (Full, Class_Wide_Type (Priv));
14362 end if;
14363 end if;
14365 Set_Is_Volatile (Full, Is_Volatile (Priv));
14366 Set_Treat_As_Volatile (Full, Treat_As_Volatile (Priv));
14367 Set_Scope (Full, Scope (Priv));
14368 Set_Next_Entity (Full, Next_Entity (Priv));
14369 Set_First_Entity (Full, First_Entity (Priv));
14370 Set_Last_Entity (Full, Last_Entity (Priv));
14372 -- If access types have been recorded for later handling, keep them in
14373 -- the full view so that they get handled when the full view freeze
14374 -- node is expanded.
14376 if Present (Freeze_Node (Priv))
14377 and then Present (Access_Types_To_Process (Freeze_Node (Priv)))
14378 then
14379 Ensure_Freeze_Node (Full);
14380 Set_Access_Types_To_Process
14381 (Freeze_Node (Full),
14382 Access_Types_To_Process (Freeze_Node (Priv)));
14383 end if;
14385 -- Swap the two entities. Now Private is the full type entity and Full
14386 -- is the private one. They will be swapped back at the end of the
14387 -- private part. This swapping ensures that the entity that is visible
14388 -- in the private part is the full declaration.
14390 Exchange_Entities (Priv, Full);
14391 Append_Entity (Full, Scope (Full));
14392 end Copy_And_Swap;
14394 -------------------------------------
14395 -- Copy_Array_Base_Type_Attributes --
14396 -------------------------------------
14398 procedure Copy_Array_Base_Type_Attributes (T1, T2 : Entity_Id) is
14399 begin
14400 Set_Component_Alignment (T1, Component_Alignment (T2));
14401 Set_Component_Type (T1, Component_Type (T2));
14402 Set_Component_Size (T1, Component_Size (T2));
14403 Set_Has_Controlled_Component (T1, Has_Controlled_Component (T2));
14404 Set_Has_Non_Standard_Rep (T1, Has_Non_Standard_Rep (T2));
14405 Propagate_Concurrent_Flags (T1, T2);
14406 Set_Is_Packed (T1, Is_Packed (T2));
14407 Set_Has_Aliased_Components (T1, Has_Aliased_Components (T2));
14408 Set_Has_Atomic_Components (T1, Has_Atomic_Components (T2));
14409 Set_Has_Volatile_Components (T1, Has_Volatile_Components (T2));
14410 end Copy_Array_Base_Type_Attributes;
14412 -----------------------------------
14413 -- Copy_Array_Subtype_Attributes --
14414 -----------------------------------
14416 procedure Copy_Array_Subtype_Attributes (T1, T2 : Entity_Id) is
14417 begin
14418 Set_Size_Info (T1, T2);
14420 Set_First_Index (T1, First_Index (T2));
14421 Set_Is_Aliased (T1, Is_Aliased (T2));
14422 Set_Is_Volatile (T1, Is_Volatile (T2));
14423 Set_Treat_As_Volatile (T1, Treat_As_Volatile (T2));
14424 Set_Is_Constrained (T1, Is_Constrained (T2));
14425 Set_Depends_On_Private (T1, Has_Private_Component (T2));
14426 Inherit_Rep_Item_Chain (T1, T2);
14427 Set_Convention (T1, Convention (T2));
14428 Set_Is_Limited_Composite (T1, Is_Limited_Composite (T2));
14429 Set_Is_Private_Composite (T1, Is_Private_Composite (T2));
14430 Set_Packed_Array_Impl_Type (T1, Packed_Array_Impl_Type (T2));
14431 end Copy_Array_Subtype_Attributes;
14433 -----------------------------------
14434 -- Create_Constrained_Components --
14435 -----------------------------------
14437 procedure Create_Constrained_Components
14438 (Subt : Entity_Id;
14439 Decl_Node : Node_Id;
14440 Typ : Entity_Id;
14441 Constraints : Elist_Id)
14443 Loc : constant Source_Ptr := Sloc (Subt);
14444 Comp_List : constant Elist_Id := New_Elmt_List;
14445 Parent_Type : constant Entity_Id := Etype (Typ);
14446 Assoc_List : constant List_Id := New_List;
14447 Discr_Val : Elmt_Id;
14448 Errors : Boolean;
14449 New_C : Entity_Id;
14450 Old_C : Entity_Id;
14451 Is_Static : Boolean := True;
14453 procedure Collect_Fixed_Components (Typ : Entity_Id);
14454 -- Collect parent type components that do not appear in a variant part
14456 procedure Create_All_Components;
14457 -- Iterate over Comp_List to create the components of the subtype
14459 function Create_Component (Old_Compon : Entity_Id) return Entity_Id;
14460 -- Creates a new component from Old_Compon, copying all the fields from
14461 -- it, including its Etype, inserts the new component in the Subt entity
14462 -- chain and returns the new component.
14464 function Is_Variant_Record (T : Entity_Id) return Boolean;
14465 -- If true, and discriminants are static, collect only components from
14466 -- variants selected by discriminant values.
14468 ------------------------------
14469 -- Collect_Fixed_Components --
14470 ------------------------------
14472 procedure Collect_Fixed_Components (Typ : Entity_Id) is
14473 begin
14474 -- Build association list for discriminants, and find components of the
14475 -- variant part selected by the values of the discriminants.
14477 Old_C := First_Discriminant (Typ);
14478 Discr_Val := First_Elmt (Constraints);
14479 while Present (Old_C) loop
14480 Append_To (Assoc_List,
14481 Make_Component_Association (Loc,
14482 Choices => New_List (New_Occurrence_Of (Old_C, Loc)),
14483 Expression => New_Copy (Node (Discr_Val))));
14485 Next_Elmt (Discr_Val);
14486 Next_Discriminant (Old_C);
14487 end loop;
14489 -- The tag and the possible parent component are unconditionally in
14490 -- the subtype.
14492 if Is_Tagged_Type (Typ) or else Has_Controlled_Component (Typ) then
14493 Old_C := First_Component (Typ);
14494 while Present (Old_C) loop
14495 if Nam_In (Chars (Old_C), Name_uTag, Name_uParent) then
14496 Append_Elmt (Old_C, Comp_List);
14497 end if;
14499 Next_Component (Old_C);
14500 end loop;
14501 end if;
14502 end Collect_Fixed_Components;
14504 ---------------------------
14505 -- Create_All_Components --
14506 ---------------------------
14508 procedure Create_All_Components is
14509 Comp : Elmt_Id;
14511 begin
14512 Comp := First_Elmt (Comp_List);
14513 while Present (Comp) loop
14514 Old_C := Node (Comp);
14515 New_C := Create_Component (Old_C);
14517 Set_Etype
14518 (New_C,
14519 Constrain_Component_Type
14520 (Old_C, Subt, Decl_Node, Typ, Constraints));
14521 Set_Is_Public (New_C, Is_Public (Subt));
14523 Next_Elmt (Comp);
14524 end loop;
14525 end Create_All_Components;
14527 ----------------------
14528 -- Create_Component --
14529 ----------------------
14531 function Create_Component (Old_Compon : Entity_Id) return Entity_Id is
14532 New_Compon : constant Entity_Id := New_Copy (Old_Compon);
14534 begin
14535 if Ekind (Old_Compon) = E_Discriminant
14536 and then Is_Completely_Hidden (Old_Compon)
14537 then
14538 -- This is a shadow discriminant created for a discriminant of
14539 -- the parent type, which needs to be present in the subtype.
14540 -- Give the shadow discriminant an internal name that cannot
14541 -- conflict with that of visible components.
14543 Set_Chars (New_Compon, New_Internal_Name ('C'));
14544 end if;
14546 -- Set the parent so we have a proper link for freezing etc. This is
14547 -- not a real parent pointer, since of course our parent does not own
14548 -- up to us and reference us, we are an illegitimate child of the
14549 -- original parent.
14551 Set_Parent (New_Compon, Parent (Old_Compon));
14553 -- We do not want this node marked as Comes_From_Source, since
14554 -- otherwise it would get first class status and a separate cross-
14555 -- reference line would be generated. Illegitimate children do not
14556 -- rate such recognition.
14558 Set_Comes_From_Source (New_Compon, False);
14560 -- But it is a real entity, and a birth certificate must be properly
14561 -- registered by entering it into the entity list.
14563 Enter_Name (New_Compon);
14565 return New_Compon;
14566 end Create_Component;
14568 -----------------------
14569 -- Is_Variant_Record --
14570 -----------------------
14572 function Is_Variant_Record (T : Entity_Id) return Boolean is
14573 begin
14574 return Nkind (Parent (T)) = N_Full_Type_Declaration
14575 and then Nkind (Type_Definition (Parent (T))) = N_Record_Definition
14576 and then Present (Component_List (Type_Definition (Parent (T))))
14577 and then
14578 Present
14579 (Variant_Part (Component_List (Type_Definition (Parent (T)))));
14580 end Is_Variant_Record;
14582 -- Start of processing for Create_Constrained_Components
14584 begin
14585 pragma Assert (Subt /= Base_Type (Subt));
14586 pragma Assert (Typ = Base_Type (Typ));
14588 Set_First_Entity (Subt, Empty);
14589 Set_Last_Entity (Subt, Empty);
14591 -- Check whether constraint is fully static, in which case we can
14592 -- optimize the list of components.
14594 Discr_Val := First_Elmt (Constraints);
14595 while Present (Discr_Val) loop
14596 if not Is_OK_Static_Expression (Node (Discr_Val)) then
14597 Is_Static := False;
14598 exit;
14599 end if;
14601 Next_Elmt (Discr_Val);
14602 end loop;
14604 Set_Has_Static_Discriminants (Subt, Is_Static);
14606 Push_Scope (Subt);
14608 -- Inherit the discriminants of the parent type
14610 Add_Discriminants : declare
14611 Num_Disc : Nat;
14612 Num_Gird : Nat;
14614 begin
14615 Num_Disc := 0;
14616 Old_C := First_Discriminant (Typ);
14618 while Present (Old_C) loop
14619 Num_Disc := Num_Disc + 1;
14620 New_C := Create_Component (Old_C);
14621 Set_Is_Public (New_C, Is_Public (Subt));
14622 Next_Discriminant (Old_C);
14623 end loop;
14625 -- For an untagged derived subtype, the number of discriminants may
14626 -- be smaller than the number of inherited discriminants, because
14627 -- several of them may be renamed by a single new discriminant or
14628 -- constrained. In this case, add the hidden discriminants back into
14629 -- the subtype, because they need to be present if the optimizer of
14630 -- the GCC 4.x back-end decides to break apart assignments between
14631 -- objects using the parent view into member-wise assignments.
14633 Num_Gird := 0;
14635 if Is_Derived_Type (Typ)
14636 and then not Is_Tagged_Type (Typ)
14637 then
14638 Old_C := First_Stored_Discriminant (Typ);
14640 while Present (Old_C) loop
14641 Num_Gird := Num_Gird + 1;
14642 Next_Stored_Discriminant (Old_C);
14643 end loop;
14644 end if;
14646 if Num_Gird > Num_Disc then
14648 -- Find out multiple uses of new discriminants, and add hidden
14649 -- components for the extra renamed discriminants. We recognize
14650 -- multiple uses through the Corresponding_Discriminant of a
14651 -- new discriminant: if it constrains several old discriminants,
14652 -- this field points to the last one in the parent type. The
14653 -- stored discriminants of the derived type have the same name
14654 -- as those of the parent.
14656 declare
14657 Constr : Elmt_Id;
14658 New_Discr : Entity_Id;
14659 Old_Discr : Entity_Id;
14661 begin
14662 Constr := First_Elmt (Stored_Constraint (Typ));
14663 Old_Discr := First_Stored_Discriminant (Typ);
14664 while Present (Constr) loop
14665 if Is_Entity_Name (Node (Constr))
14666 and then Ekind (Entity (Node (Constr))) = E_Discriminant
14667 then
14668 New_Discr := Entity (Node (Constr));
14670 if Chars (Corresponding_Discriminant (New_Discr)) /=
14671 Chars (Old_Discr)
14672 then
14673 -- The new discriminant has been used to rename a
14674 -- subsequent old discriminant. Introduce a shadow
14675 -- component for the current old discriminant.
14677 New_C := Create_Component (Old_Discr);
14678 Set_Original_Record_Component (New_C, Old_Discr);
14679 end if;
14681 else
14682 -- The constraint has eliminated the old discriminant.
14683 -- Introduce a shadow component.
14685 New_C := Create_Component (Old_Discr);
14686 Set_Original_Record_Component (New_C, Old_Discr);
14687 end if;
14689 Next_Elmt (Constr);
14690 Next_Stored_Discriminant (Old_Discr);
14691 end loop;
14692 end;
14693 end if;
14694 end Add_Discriminants;
14696 if Is_Static
14697 and then Is_Variant_Record (Typ)
14698 then
14699 Collect_Fixed_Components (Typ);
14701 Gather_Components (
14702 Typ,
14703 Component_List (Type_Definition (Parent (Typ))),
14704 Governed_By => Assoc_List,
14705 Into => Comp_List,
14706 Report_Errors => Errors);
14707 pragma Assert (not Errors
14708 or else Serious_Errors_Detected > 0);
14710 Create_All_Components;
14712 -- If the subtype declaration is created for a tagged type derivation
14713 -- with constraints, we retrieve the record definition of the parent
14714 -- type to select the components of the proper variant.
14716 elsif Is_Static
14717 and then Is_Tagged_Type (Typ)
14718 and then Nkind (Parent (Typ)) = N_Full_Type_Declaration
14719 and then
14720 Nkind (Type_Definition (Parent (Typ))) = N_Derived_Type_Definition
14721 and then Is_Variant_Record (Parent_Type)
14722 then
14723 Collect_Fixed_Components (Typ);
14725 Gather_Components
14726 (Typ,
14727 Component_List (Type_Definition (Parent (Parent_Type))),
14728 Governed_By => Assoc_List,
14729 Into => Comp_List,
14730 Report_Errors => Errors);
14732 -- Note: previously there was a check at this point that no errors
14733 -- were detected. As a consequence of AI05-220 there may be an error
14734 -- if an inherited discriminant that controls a variant has a non-
14735 -- static constraint.
14737 -- If the tagged derivation has a type extension, collect all the
14738 -- new components therein.
14740 if Present (Record_Extension_Part (Type_Definition (Parent (Typ))))
14741 then
14742 Old_C := First_Component (Typ);
14743 while Present (Old_C) loop
14744 if Original_Record_Component (Old_C) = Old_C
14745 and then Chars (Old_C) /= Name_uTag
14746 and then Chars (Old_C) /= Name_uParent
14747 then
14748 Append_Elmt (Old_C, Comp_List);
14749 end if;
14751 Next_Component (Old_C);
14752 end loop;
14753 end if;
14755 Create_All_Components;
14757 else
14758 -- If discriminants are not static, or if this is a multi-level type
14759 -- extension, we have to include all components of the parent type.
14761 Old_C := First_Component (Typ);
14762 while Present (Old_C) loop
14763 New_C := Create_Component (Old_C);
14765 Set_Etype
14766 (New_C,
14767 Constrain_Component_Type
14768 (Old_C, Subt, Decl_Node, Typ, Constraints));
14769 Set_Is_Public (New_C, Is_Public (Subt));
14771 Next_Component (Old_C);
14772 end loop;
14773 end if;
14775 End_Scope;
14776 end Create_Constrained_Components;
14778 ------------------------------------------
14779 -- Decimal_Fixed_Point_Type_Declaration --
14780 ------------------------------------------
14782 procedure Decimal_Fixed_Point_Type_Declaration
14783 (T : Entity_Id;
14784 Def : Node_Id)
14786 Loc : constant Source_Ptr := Sloc (Def);
14787 Digs_Expr : constant Node_Id := Digits_Expression (Def);
14788 Delta_Expr : constant Node_Id := Delta_Expression (Def);
14789 Implicit_Base : Entity_Id;
14790 Digs_Val : Uint;
14791 Delta_Val : Ureal;
14792 Scale_Val : Uint;
14793 Bound_Val : Ureal;
14795 begin
14796 Check_SPARK_05_Restriction
14797 ("decimal fixed point type is not allowed", Def);
14798 Check_Restriction (No_Fixed_Point, Def);
14800 -- Create implicit base type
14802 Implicit_Base :=
14803 Create_Itype (E_Decimal_Fixed_Point_Type, Parent (Def), T, 'B');
14804 Set_Etype (Implicit_Base, Implicit_Base);
14806 -- Analyze and process delta expression
14808 Analyze_And_Resolve (Delta_Expr, Universal_Real);
14810 Check_Delta_Expression (Delta_Expr);
14811 Delta_Val := Expr_Value_R (Delta_Expr);
14813 -- Check delta is power of 10, and determine scale value from it
14815 declare
14816 Val : Ureal;
14818 begin
14819 Scale_Val := Uint_0;
14820 Val := Delta_Val;
14822 if Val < Ureal_1 then
14823 while Val < Ureal_1 loop
14824 Val := Val * Ureal_10;
14825 Scale_Val := Scale_Val + 1;
14826 end loop;
14828 if Scale_Val > 18 then
14829 Error_Msg_N ("scale exceeds maximum value of 18", Def);
14830 Scale_Val := UI_From_Int (+18);
14831 end if;
14833 else
14834 while Val > Ureal_1 loop
14835 Val := Val / Ureal_10;
14836 Scale_Val := Scale_Val - 1;
14837 end loop;
14839 if Scale_Val < -18 then
14840 Error_Msg_N ("scale is less than minimum value of -18", Def);
14841 Scale_Val := UI_From_Int (-18);
14842 end if;
14843 end if;
14845 if Val /= Ureal_1 then
14846 Error_Msg_N ("delta expression must be a power of 10", Def);
14847 Delta_Val := Ureal_10 ** (-Scale_Val);
14848 end if;
14849 end;
14851 -- Set delta, scale and small (small = delta for decimal type)
14853 Set_Delta_Value (Implicit_Base, Delta_Val);
14854 Set_Scale_Value (Implicit_Base, Scale_Val);
14855 Set_Small_Value (Implicit_Base, Delta_Val);
14857 -- Analyze and process digits expression
14859 Analyze_And_Resolve (Digs_Expr, Any_Integer);
14860 Check_Digits_Expression (Digs_Expr);
14861 Digs_Val := Expr_Value (Digs_Expr);
14863 if Digs_Val > 18 then
14864 Digs_Val := UI_From_Int (+18);
14865 Error_Msg_N ("digits value out of range, maximum is 18", Digs_Expr);
14866 end if;
14868 Set_Digits_Value (Implicit_Base, Digs_Val);
14869 Bound_Val := UR_From_Uint (10 ** Digs_Val - 1) * Delta_Val;
14871 -- Set range of base type from digits value for now. This will be
14872 -- expanded to represent the true underlying base range by Freeze.
14874 Set_Fixed_Range (Implicit_Base, Loc, -Bound_Val, Bound_Val);
14876 -- Note: We leave size as zero for now, size will be set at freeze
14877 -- time. We have to do this for ordinary fixed-point, because the size
14878 -- depends on the specified small, and we might as well do the same for
14879 -- decimal fixed-point.
14881 pragma Assert (Esize (Implicit_Base) = Uint_0);
14883 -- If there are bounds given in the declaration use them as the
14884 -- bounds of the first named subtype.
14886 if Present (Real_Range_Specification (Def)) then
14887 declare
14888 RRS : constant Node_Id := Real_Range_Specification (Def);
14889 Low : constant Node_Id := Low_Bound (RRS);
14890 High : constant Node_Id := High_Bound (RRS);
14891 Low_Val : Ureal;
14892 High_Val : Ureal;
14894 begin
14895 Analyze_And_Resolve (Low, Any_Real);
14896 Analyze_And_Resolve (High, Any_Real);
14897 Check_Real_Bound (Low);
14898 Check_Real_Bound (High);
14899 Low_Val := Expr_Value_R (Low);
14900 High_Val := Expr_Value_R (High);
14902 if Low_Val < (-Bound_Val) then
14903 Error_Msg_N
14904 ("range low bound too small for digits value", Low);
14905 Low_Val := -Bound_Val;
14906 end if;
14908 if High_Val > Bound_Val then
14909 Error_Msg_N
14910 ("range high bound too large for digits value", High);
14911 High_Val := Bound_Val;
14912 end if;
14914 Set_Fixed_Range (T, Loc, Low_Val, High_Val);
14915 end;
14917 -- If no explicit range, use range that corresponds to given
14918 -- digits value. This will end up as the final range for the
14919 -- first subtype.
14921 else
14922 Set_Fixed_Range (T, Loc, -Bound_Val, Bound_Val);
14923 end if;
14925 -- Complete entity for first subtype. The inheritance of the rep item
14926 -- chain ensures that SPARK-related pragmas are not clobbered when the
14927 -- decimal fixed point type acts as a full view of a private type.
14929 Set_Ekind (T, E_Decimal_Fixed_Point_Subtype);
14930 Set_Etype (T, Implicit_Base);
14931 Set_Size_Info (T, Implicit_Base);
14932 Inherit_Rep_Item_Chain (T, Implicit_Base);
14933 Set_Digits_Value (T, Digs_Val);
14934 Set_Delta_Value (T, Delta_Val);
14935 Set_Small_Value (T, Delta_Val);
14936 Set_Scale_Value (T, Scale_Val);
14937 Set_Is_Constrained (T);
14938 end Decimal_Fixed_Point_Type_Declaration;
14940 -----------------------------------
14941 -- Derive_Progenitor_Subprograms --
14942 -----------------------------------
14944 procedure Derive_Progenitor_Subprograms
14945 (Parent_Type : Entity_Id;
14946 Tagged_Type : Entity_Id)
14948 E : Entity_Id;
14949 Elmt : Elmt_Id;
14950 Iface : Entity_Id;
14951 Iface_Elmt : Elmt_Id;
14952 Iface_Subp : Entity_Id;
14953 New_Subp : Entity_Id := Empty;
14954 Prim_Elmt : Elmt_Id;
14955 Subp : Entity_Id;
14956 Typ : Entity_Id;
14958 begin
14959 pragma Assert (Ada_Version >= Ada_2005
14960 and then Is_Record_Type (Tagged_Type)
14961 and then Is_Tagged_Type (Tagged_Type)
14962 and then Has_Interfaces (Tagged_Type));
14964 -- Step 1: Transfer to the full-view primitives associated with the
14965 -- partial-view that cover interface primitives. Conceptually this
14966 -- work should be done later by Process_Full_View; done here to
14967 -- simplify its implementation at later stages. It can be safely
14968 -- done here because interfaces must be visible in the partial and
14969 -- private view (RM 7.3(7.3/2)).
14971 -- Small optimization: This work is only required if the parent may
14972 -- have entities whose Alias attribute reference an interface primitive.
14973 -- Such a situation may occur if the parent is an abstract type and the
14974 -- primitive has not been yet overridden or if the parent is a generic
14975 -- formal type covering interfaces.
14977 -- If the tagged type is not abstract, it cannot have abstract
14978 -- primitives (the only entities in the list of primitives of
14979 -- non-abstract tagged types that can reference abstract primitives
14980 -- through its Alias attribute are the internal entities that have
14981 -- attribute Interface_Alias, and these entities are generated later
14982 -- by Add_Internal_Interface_Entities).
14984 if In_Private_Part (Current_Scope)
14985 and then (Is_Abstract_Type (Parent_Type)
14986 or else
14987 Is_Generic_Type (Parent_Type))
14988 then
14989 Elmt := First_Elmt (Primitive_Operations (Tagged_Type));
14990 while Present (Elmt) loop
14991 Subp := Node (Elmt);
14993 -- At this stage it is not possible to have entities in the list
14994 -- of primitives that have attribute Interface_Alias.
14996 pragma Assert (No (Interface_Alias (Subp)));
14998 Typ := Find_Dispatching_Type (Ultimate_Alias (Subp));
15000 if Is_Interface (Typ) then
15001 E := Find_Primitive_Covering_Interface
15002 (Tagged_Type => Tagged_Type,
15003 Iface_Prim => Subp);
15005 if Present (E)
15006 and then Find_Dispatching_Type (Ultimate_Alias (E)) /= Typ
15007 then
15008 Replace_Elmt (Elmt, E);
15009 Remove_Homonym (Subp);
15010 end if;
15011 end if;
15013 Next_Elmt (Elmt);
15014 end loop;
15015 end if;
15017 -- Step 2: Add primitives of progenitors that are not implemented by
15018 -- parents of Tagged_Type.
15020 if Present (Interfaces (Base_Type (Tagged_Type))) then
15021 Iface_Elmt := First_Elmt (Interfaces (Base_Type (Tagged_Type)));
15022 while Present (Iface_Elmt) loop
15023 Iface := Node (Iface_Elmt);
15025 Prim_Elmt := First_Elmt (Primitive_Operations (Iface));
15026 while Present (Prim_Elmt) loop
15027 Iface_Subp := Node (Prim_Elmt);
15029 -- Exclude derivation of predefined primitives except those
15030 -- that come from source, or are inherited from one that comes
15031 -- from source. Required to catch declarations of equality
15032 -- operators of interfaces. For example:
15034 -- type Iface is interface;
15035 -- function "=" (Left, Right : Iface) return Boolean;
15037 if not Is_Predefined_Dispatching_Operation (Iface_Subp)
15038 or else Comes_From_Source (Ultimate_Alias (Iface_Subp))
15039 then
15040 E := Find_Primitive_Covering_Interface
15041 (Tagged_Type => Tagged_Type,
15042 Iface_Prim => Iface_Subp);
15044 -- If not found we derive a new primitive leaving its alias
15045 -- attribute referencing the interface primitive.
15047 if No (E) then
15048 Derive_Subprogram
15049 (New_Subp, Iface_Subp, Tagged_Type, Iface);
15051 -- Ada 2012 (AI05-0197): If the covering primitive's name
15052 -- differs from the name of the interface primitive then it
15053 -- is a private primitive inherited from a parent type. In
15054 -- such case, given that Tagged_Type covers the interface,
15055 -- the inherited private primitive becomes visible. For such
15056 -- purpose we add a new entity that renames the inherited
15057 -- private primitive.
15059 elsif Chars (E) /= Chars (Iface_Subp) then
15060 pragma Assert (Has_Suffix (E, 'P'));
15061 Derive_Subprogram
15062 (New_Subp, Iface_Subp, Tagged_Type, Iface);
15063 Set_Alias (New_Subp, E);
15064 Set_Is_Abstract_Subprogram (New_Subp,
15065 Is_Abstract_Subprogram (E));
15067 -- Propagate to the full view interface entities associated
15068 -- with the partial view.
15070 elsif In_Private_Part (Current_Scope)
15071 and then Present (Alias (E))
15072 and then Alias (E) = Iface_Subp
15073 and then
15074 List_Containing (Parent (E)) /=
15075 Private_Declarations
15076 (Specification
15077 (Unit_Declaration_Node (Current_Scope)))
15078 then
15079 Append_Elmt (E, Primitive_Operations (Tagged_Type));
15080 end if;
15081 end if;
15083 Next_Elmt (Prim_Elmt);
15084 end loop;
15086 Next_Elmt (Iface_Elmt);
15087 end loop;
15088 end if;
15089 end Derive_Progenitor_Subprograms;
15091 -----------------------
15092 -- Derive_Subprogram --
15093 -----------------------
15095 procedure Derive_Subprogram
15096 (New_Subp : out Entity_Id;
15097 Parent_Subp : Entity_Id;
15098 Derived_Type : Entity_Id;
15099 Parent_Type : Entity_Id;
15100 Actual_Subp : Entity_Id := Empty)
15102 Formal : Entity_Id;
15103 -- Formal parameter of parent primitive operation
15105 Formal_Of_Actual : Entity_Id;
15106 -- Formal parameter of actual operation, when the derivation is to
15107 -- create a renaming for a primitive operation of an actual in an
15108 -- instantiation.
15110 New_Formal : Entity_Id;
15111 -- Formal of inherited operation
15113 Visible_Subp : Entity_Id := Parent_Subp;
15115 function Is_Private_Overriding return Boolean;
15116 -- If Subp is a private overriding of a visible operation, the inherited
15117 -- operation derives from the overridden op (even though its body is the
15118 -- overriding one) and the inherited operation is visible now. See
15119 -- sem_disp to see the full details of the handling of the overridden
15120 -- subprogram, which is removed from the list of primitive operations of
15121 -- the type. The overridden subprogram is saved locally in Visible_Subp,
15122 -- and used to diagnose abstract operations that need overriding in the
15123 -- derived type.
15125 procedure Replace_Type (Id, New_Id : Entity_Id);
15126 -- When the type is an anonymous access type, create a new access type
15127 -- designating the derived type.
15129 procedure Set_Derived_Name;
15130 -- This procedure sets the appropriate Chars name for New_Subp. This
15131 -- is normally just a copy of the parent name. An exception arises for
15132 -- type support subprograms, where the name is changed to reflect the
15133 -- name of the derived type, e.g. if type foo is derived from type bar,
15134 -- then a procedure barDA is derived with a name fooDA.
15136 ---------------------------
15137 -- Is_Private_Overriding --
15138 ---------------------------
15140 function Is_Private_Overriding return Boolean is
15141 Prev : Entity_Id;
15143 begin
15144 -- If the parent is not a dispatching operation there is no
15145 -- need to investigate overridings
15147 if not Is_Dispatching_Operation (Parent_Subp) then
15148 return False;
15149 end if;
15151 -- The visible operation that is overridden is a homonym of the
15152 -- parent subprogram. We scan the homonym chain to find the one
15153 -- whose alias is the subprogram we are deriving.
15155 Prev := Current_Entity (Parent_Subp);
15156 while Present (Prev) loop
15157 if Ekind (Prev) = Ekind (Parent_Subp)
15158 and then Alias (Prev) = Parent_Subp
15159 and then Scope (Parent_Subp) = Scope (Prev)
15160 and then not Is_Hidden (Prev)
15161 then
15162 Visible_Subp := Prev;
15163 return True;
15164 end if;
15166 Prev := Homonym (Prev);
15167 end loop;
15169 return False;
15170 end Is_Private_Overriding;
15172 ------------------
15173 -- Replace_Type --
15174 ------------------
15176 procedure Replace_Type (Id, New_Id : Entity_Id) is
15177 Id_Type : constant Entity_Id := Etype (Id);
15178 Acc_Type : Entity_Id;
15179 Par : constant Node_Id := Parent (Derived_Type);
15181 begin
15182 -- When the type is an anonymous access type, create a new access
15183 -- type designating the derived type. This itype must be elaborated
15184 -- at the point of the derivation, not on subsequent calls that may
15185 -- be out of the proper scope for Gigi, so we insert a reference to
15186 -- it after the derivation.
15188 if Ekind (Id_Type) = E_Anonymous_Access_Type then
15189 declare
15190 Desig_Typ : Entity_Id := Designated_Type (Id_Type);
15192 begin
15193 if Ekind (Desig_Typ) = E_Record_Type_With_Private
15194 and then Present (Full_View (Desig_Typ))
15195 and then not Is_Private_Type (Parent_Type)
15196 then
15197 Desig_Typ := Full_View (Desig_Typ);
15198 end if;
15200 if Base_Type (Desig_Typ) = Base_Type (Parent_Type)
15202 -- Ada 2005 (AI-251): Handle also derivations of abstract
15203 -- interface primitives.
15205 or else (Is_Interface (Desig_Typ)
15206 and then not Is_Class_Wide_Type (Desig_Typ))
15207 then
15208 Acc_Type := New_Copy (Id_Type);
15209 Set_Etype (Acc_Type, Acc_Type);
15210 Set_Scope (Acc_Type, New_Subp);
15212 -- Set size of anonymous access type. If we have an access
15213 -- to an unconstrained array, this is a fat pointer, so it
15214 -- is sizes at twice addtress size.
15216 if Is_Array_Type (Desig_Typ)
15217 and then not Is_Constrained (Desig_Typ)
15218 then
15219 Init_Size (Acc_Type, 2 * System_Address_Size);
15221 -- Other cases use a thin pointer
15223 else
15224 Init_Size (Acc_Type, System_Address_Size);
15225 end if;
15227 -- Set remaining characterstics of anonymous access type
15229 Init_Alignment (Acc_Type);
15230 Set_Directly_Designated_Type (Acc_Type, Derived_Type);
15232 Set_Etype (New_Id, Acc_Type);
15233 Set_Scope (New_Id, New_Subp);
15235 -- Create a reference to it
15237 Build_Itype_Reference (Acc_Type, Parent (Derived_Type));
15239 else
15240 Set_Etype (New_Id, Id_Type);
15241 end if;
15242 end;
15244 -- In Ada2012, a formal may have an incomplete type but the type
15245 -- derivation that inherits the primitive follows the full view.
15247 elsif Base_Type (Id_Type) = Base_Type (Parent_Type)
15248 or else
15249 (Ekind (Id_Type) = E_Record_Type_With_Private
15250 and then Present (Full_View (Id_Type))
15251 and then
15252 Base_Type (Full_View (Id_Type)) = Base_Type (Parent_Type))
15253 or else
15254 (Ada_Version >= Ada_2012
15255 and then Ekind (Id_Type) = E_Incomplete_Type
15256 and then Full_View (Id_Type) = Parent_Type)
15257 then
15258 -- Constraint checks on formals are generated during expansion,
15259 -- based on the signature of the original subprogram. The bounds
15260 -- of the derived type are not relevant, and thus we can use
15261 -- the base type for the formals. However, the return type may be
15262 -- used in a context that requires that the proper static bounds
15263 -- be used (a case statement, for example) and for those cases
15264 -- we must use the derived type (first subtype), not its base.
15266 -- If the derived_type_definition has no constraints, we know that
15267 -- the derived type has the same constraints as the first subtype
15268 -- of the parent, and we can also use it rather than its base,
15269 -- which can lead to more efficient code.
15271 if Etype (Id) = Parent_Type then
15272 if Is_Scalar_Type (Parent_Type)
15273 and then
15274 Subtypes_Statically_Compatible (Parent_Type, Derived_Type)
15275 then
15276 Set_Etype (New_Id, Derived_Type);
15278 elsif Nkind (Par) = N_Full_Type_Declaration
15279 and then
15280 Nkind (Type_Definition (Par)) = N_Derived_Type_Definition
15281 and then
15282 Is_Entity_Name
15283 (Subtype_Indication (Type_Definition (Par)))
15284 then
15285 Set_Etype (New_Id, Derived_Type);
15287 else
15288 Set_Etype (New_Id, Base_Type (Derived_Type));
15289 end if;
15291 else
15292 Set_Etype (New_Id, Base_Type (Derived_Type));
15293 end if;
15295 else
15296 Set_Etype (New_Id, Etype (Id));
15297 end if;
15298 end Replace_Type;
15300 ----------------------
15301 -- Set_Derived_Name --
15302 ----------------------
15304 procedure Set_Derived_Name is
15305 Nm : constant TSS_Name_Type := Get_TSS_Name (Parent_Subp);
15306 begin
15307 if Nm = TSS_Null then
15308 Set_Chars (New_Subp, Chars (Parent_Subp));
15309 else
15310 Set_Chars (New_Subp, Make_TSS_Name (Base_Type (Derived_Type), Nm));
15311 end if;
15312 end Set_Derived_Name;
15314 -- Start of processing for Derive_Subprogram
15316 begin
15317 New_Subp := New_Entity (Nkind (Parent_Subp), Sloc (Derived_Type));
15318 Set_Ekind (New_Subp, Ekind (Parent_Subp));
15320 -- Check whether the inherited subprogram is a private operation that
15321 -- should be inherited but not yet made visible. Such subprograms can
15322 -- become visible at a later point (e.g., the private part of a public
15323 -- child unit) via Declare_Inherited_Private_Subprograms. If the
15324 -- following predicate is true, then this is not such a private
15325 -- operation and the subprogram simply inherits the name of the parent
15326 -- subprogram. Note the special check for the names of controlled
15327 -- operations, which are currently exempted from being inherited with
15328 -- a hidden name because they must be findable for generation of
15329 -- implicit run-time calls.
15331 if not Is_Hidden (Parent_Subp)
15332 or else Is_Internal (Parent_Subp)
15333 or else Is_Private_Overriding
15334 or else Is_Internal_Name (Chars (Parent_Subp))
15335 or else (Is_Controlled (Parent_Type)
15336 and then Nam_In (Chars (Parent_Subp), Name_Adjust,
15337 Name_Finalize,
15338 Name_Initialize))
15339 then
15340 Set_Derived_Name;
15342 -- An inherited dispatching equality will be overridden by an internally
15343 -- generated one, or by an explicit one, so preserve its name and thus
15344 -- its entry in the dispatch table. Otherwise, if Parent_Subp is a
15345 -- private operation it may become invisible if the full view has
15346 -- progenitors, and the dispatch table will be malformed.
15347 -- We check that the type is limited to handle the anomalous declaration
15348 -- of Limited_Controlled, which is derived from a non-limited type, and
15349 -- which is handled specially elsewhere as well.
15351 elsif Chars (Parent_Subp) = Name_Op_Eq
15352 and then Is_Dispatching_Operation (Parent_Subp)
15353 and then Etype (Parent_Subp) = Standard_Boolean
15354 and then not Is_Limited_Type (Etype (First_Formal (Parent_Subp)))
15355 and then
15356 Etype (First_Formal (Parent_Subp)) =
15357 Etype (Next_Formal (First_Formal (Parent_Subp)))
15358 then
15359 Set_Derived_Name;
15361 -- If parent is hidden, this can be a regular derivation if the
15362 -- parent is immediately visible in a non-instantiating context,
15363 -- or if we are in the private part of an instance. This test
15364 -- should still be refined ???
15366 -- The test for In_Instance_Not_Visible avoids inheriting the derived
15367 -- operation as a non-visible operation in cases where the parent
15368 -- subprogram might not be visible now, but was visible within the
15369 -- original generic, so it would be wrong to make the inherited
15370 -- subprogram non-visible now. (Not clear if this test is fully
15371 -- correct; are there any cases where we should declare the inherited
15372 -- operation as not visible to avoid it being overridden, e.g., when
15373 -- the parent type is a generic actual with private primitives ???)
15375 -- (they should be treated the same as other private inherited
15376 -- subprograms, but it's not clear how to do this cleanly). ???
15378 elsif (In_Open_Scopes (Scope (Base_Type (Parent_Type)))
15379 and then Is_Immediately_Visible (Parent_Subp)
15380 and then not In_Instance)
15381 or else In_Instance_Not_Visible
15382 then
15383 Set_Derived_Name;
15385 -- Ada 2005 (AI-251): Regular derivation if the parent subprogram
15386 -- overrides an interface primitive because interface primitives
15387 -- must be visible in the partial view of the parent (RM 7.3 (7.3/2))
15389 elsif Ada_Version >= Ada_2005
15390 and then Is_Dispatching_Operation (Parent_Subp)
15391 and then Present (Covered_Interface_Op (Parent_Subp))
15392 then
15393 Set_Derived_Name;
15395 -- Otherwise, the type is inheriting a private operation, so enter it
15396 -- with a special name so it can't be overridden.
15398 else
15399 Set_Chars (New_Subp, New_External_Name (Chars (Parent_Subp), 'P'));
15400 end if;
15402 Set_Parent (New_Subp, Parent (Derived_Type));
15404 if Present (Actual_Subp) then
15405 Replace_Type (Actual_Subp, New_Subp);
15406 else
15407 Replace_Type (Parent_Subp, New_Subp);
15408 end if;
15410 Conditional_Delay (New_Subp, Parent_Subp);
15412 -- If we are creating a renaming for a primitive operation of an
15413 -- actual of a generic derived type, we must examine the signature
15414 -- of the actual primitive, not that of the generic formal, which for
15415 -- example may be an interface. However the name and initial value
15416 -- of the inherited operation are those of the formal primitive.
15418 Formal := First_Formal (Parent_Subp);
15420 if Present (Actual_Subp) then
15421 Formal_Of_Actual := First_Formal (Actual_Subp);
15422 else
15423 Formal_Of_Actual := Empty;
15424 end if;
15426 while Present (Formal) loop
15427 New_Formal := New_Copy (Formal);
15429 -- Normally we do not go copying parents, but in the case of
15430 -- formals, we need to link up to the declaration (which is the
15431 -- parameter specification), and it is fine to link up to the
15432 -- original formal's parameter specification in this case.
15434 Set_Parent (New_Formal, Parent (Formal));
15435 Append_Entity (New_Formal, New_Subp);
15437 if Present (Formal_Of_Actual) then
15438 Replace_Type (Formal_Of_Actual, New_Formal);
15439 Next_Formal (Formal_Of_Actual);
15440 else
15441 Replace_Type (Formal, New_Formal);
15442 end if;
15444 Next_Formal (Formal);
15445 end loop;
15447 -- If this derivation corresponds to a tagged generic actual, then
15448 -- primitive operations rename those of the actual. Otherwise the
15449 -- primitive operations rename those of the parent type, If the parent
15450 -- renames an intrinsic operator, so does the new subprogram. We except
15451 -- concatenation, which is always properly typed, and does not get
15452 -- expanded as other intrinsic operations.
15454 if No (Actual_Subp) then
15455 if Is_Intrinsic_Subprogram (Parent_Subp) then
15456 Set_Is_Intrinsic_Subprogram (New_Subp);
15458 if Present (Alias (Parent_Subp))
15459 and then Chars (Parent_Subp) /= Name_Op_Concat
15460 then
15461 Set_Alias (New_Subp, Alias (Parent_Subp));
15462 else
15463 Set_Alias (New_Subp, Parent_Subp);
15464 end if;
15466 else
15467 Set_Alias (New_Subp, Parent_Subp);
15468 end if;
15470 else
15471 Set_Alias (New_Subp, Actual_Subp);
15472 end if;
15474 -- Derived subprograms of a tagged type must inherit the convention
15475 -- of the parent subprogram (a requirement of AI-117). Derived
15476 -- subprograms of untagged types simply get convention Ada by default.
15478 -- If the derived type is a tagged generic formal type with unknown
15479 -- discriminants, its convention is intrinsic (RM 6.3.1 (8)).
15481 -- However, if the type is derived from a generic formal, the further
15482 -- inherited subprogram has the convention of the non-generic ancestor.
15483 -- Otherwise there would be no way to override the operation.
15484 -- (This is subject to forthcoming ARG discussions).
15486 if Is_Tagged_Type (Derived_Type) then
15487 if Is_Generic_Type (Derived_Type)
15488 and then Has_Unknown_Discriminants (Derived_Type)
15489 then
15490 Set_Convention (New_Subp, Convention_Intrinsic);
15492 else
15493 if Is_Generic_Type (Parent_Type)
15494 and then Has_Unknown_Discriminants (Parent_Type)
15495 then
15496 Set_Convention (New_Subp, Convention (Alias (Parent_Subp)));
15497 else
15498 Set_Convention (New_Subp, Convention (Parent_Subp));
15499 end if;
15500 end if;
15501 end if;
15503 -- Predefined controlled operations retain their name even if the parent
15504 -- is hidden (see above), but they are not primitive operations if the
15505 -- ancestor is not visible, for example if the parent is a private
15506 -- extension completed with a controlled extension. Note that a full
15507 -- type that is controlled can break privacy: the flag Is_Controlled is
15508 -- set on both views of the type.
15510 if Is_Controlled (Parent_Type)
15511 and then Nam_In (Chars (Parent_Subp), Name_Initialize,
15512 Name_Adjust,
15513 Name_Finalize)
15514 and then Is_Hidden (Parent_Subp)
15515 and then not Is_Visibly_Controlled (Parent_Type)
15516 then
15517 Set_Is_Hidden (New_Subp);
15518 end if;
15520 Set_Is_Imported (New_Subp, Is_Imported (Parent_Subp));
15521 Set_Is_Exported (New_Subp, Is_Exported (Parent_Subp));
15523 if Ekind (Parent_Subp) = E_Procedure then
15524 Set_Is_Valued_Procedure
15525 (New_Subp, Is_Valued_Procedure (Parent_Subp));
15526 else
15527 Set_Has_Controlling_Result
15528 (New_Subp, Has_Controlling_Result (Parent_Subp));
15529 end if;
15531 -- No_Return must be inherited properly. If this is overridden in the
15532 -- case of a dispatching operation, then a check is made in Sem_Disp
15533 -- that the overriding operation is also No_Return (no such check is
15534 -- required for the case of non-dispatching operation.
15536 Set_No_Return (New_Subp, No_Return (Parent_Subp));
15538 -- A derived function with a controlling result is abstract. If the
15539 -- Derived_Type is a nonabstract formal generic derived type, then
15540 -- inherited operations are not abstract: the required check is done at
15541 -- instantiation time. If the derivation is for a generic actual, the
15542 -- function is not abstract unless the actual is.
15544 if Is_Generic_Type (Derived_Type)
15545 and then not Is_Abstract_Type (Derived_Type)
15546 then
15547 null;
15549 -- Ada 2005 (AI-228): Calculate the "require overriding" and "abstract"
15550 -- properties of the subprogram, as defined in RM-3.9.3(4/2-6/2).
15552 -- A subprogram subject to pragma Extensions_Visible with value False
15553 -- requires overriding if the subprogram has at least one controlling
15554 -- OUT parameter (SPARK RM 6.1.7(6)).
15556 elsif Ada_Version >= Ada_2005
15557 and then (Is_Abstract_Subprogram (Alias (New_Subp))
15558 or else (Is_Tagged_Type (Derived_Type)
15559 and then Etype (New_Subp) = Derived_Type
15560 and then not Is_Null_Extension (Derived_Type))
15561 or else (Is_Tagged_Type (Derived_Type)
15562 and then Ekind (Etype (New_Subp)) =
15563 E_Anonymous_Access_Type
15564 and then Designated_Type (Etype (New_Subp)) =
15565 Derived_Type
15566 and then not Is_Null_Extension (Derived_Type))
15567 or else (Comes_From_Source (Alias (New_Subp))
15568 and then Is_EVF_Procedure (Alias (New_Subp))))
15569 and then No (Actual_Subp)
15570 then
15571 if not Is_Tagged_Type (Derived_Type)
15572 or else Is_Abstract_Type (Derived_Type)
15573 or else Is_Abstract_Subprogram (Alias (New_Subp))
15574 then
15575 Set_Is_Abstract_Subprogram (New_Subp);
15576 else
15577 Set_Requires_Overriding (New_Subp);
15578 end if;
15580 elsif Ada_Version < Ada_2005
15581 and then (Is_Abstract_Subprogram (Alias (New_Subp))
15582 or else (Is_Tagged_Type (Derived_Type)
15583 and then Etype (New_Subp) = Derived_Type
15584 and then No (Actual_Subp)))
15585 then
15586 Set_Is_Abstract_Subprogram (New_Subp);
15588 -- AI05-0097 : an inherited operation that dispatches on result is
15589 -- abstract if the derived type is abstract, even if the parent type
15590 -- is concrete and the derived type is a null extension.
15592 elsif Has_Controlling_Result (Alias (New_Subp))
15593 and then Is_Abstract_Type (Etype (New_Subp))
15594 then
15595 Set_Is_Abstract_Subprogram (New_Subp);
15597 -- Finally, if the parent type is abstract we must verify that all
15598 -- inherited operations are either non-abstract or overridden, or that
15599 -- the derived type itself is abstract (this check is performed at the
15600 -- end of a package declaration, in Check_Abstract_Overriding). A
15601 -- private overriding in the parent type will not be visible in the
15602 -- derivation if we are not in an inner package or in a child unit of
15603 -- the parent type, in which case the abstractness of the inherited
15604 -- operation is carried to the new subprogram.
15606 elsif Is_Abstract_Type (Parent_Type)
15607 and then not In_Open_Scopes (Scope (Parent_Type))
15608 and then Is_Private_Overriding
15609 and then Is_Abstract_Subprogram (Visible_Subp)
15610 then
15611 if No (Actual_Subp) then
15612 Set_Alias (New_Subp, Visible_Subp);
15613 Set_Is_Abstract_Subprogram (New_Subp, True);
15615 else
15616 -- If this is a derivation for an instance of a formal derived
15617 -- type, abstractness comes from the primitive operation of the
15618 -- actual, not from the operation inherited from the ancestor.
15620 Set_Is_Abstract_Subprogram
15621 (New_Subp, Is_Abstract_Subprogram (Actual_Subp));
15622 end if;
15623 end if;
15625 New_Overloaded_Entity (New_Subp, Derived_Type);
15627 -- Ada RM 6.1.1 (15): If a subprogram inherits nonconforming class-wide
15628 -- preconditions and the derived type is abstract, the derived operation
15629 -- is abstract as well if parent subprogram is not abstract or null.
15631 if Is_Abstract_Type (Derived_Type)
15632 and then Has_Non_Trivial_Precondition (Parent_Subp)
15633 and then Present (Interfaces (Derived_Type))
15634 then
15636 -- Add useful attributes of subprogram before the freeze point,
15637 -- in case freezing is delayed or there are previous errors.
15639 Set_Is_Dispatching_Operation (New_Subp);
15641 declare
15642 Iface_Prim : constant Entity_Id := Covered_Interface_Op (New_Subp);
15644 begin
15645 if Present (Iface_Prim)
15646 and then Has_Non_Trivial_Precondition (Iface_Prim)
15647 then
15648 Set_Is_Abstract_Subprogram (New_Subp);
15649 end if;
15650 end;
15651 end if;
15653 -- Check for case of a derived subprogram for the instantiation of a
15654 -- formal derived tagged type, if so mark the subprogram as dispatching
15655 -- and inherit the dispatching attributes of the actual subprogram. The
15656 -- derived subprogram is effectively renaming of the actual subprogram,
15657 -- so it needs to have the same attributes as the actual.
15659 if Present (Actual_Subp)
15660 and then Is_Dispatching_Operation (Actual_Subp)
15661 then
15662 Set_Is_Dispatching_Operation (New_Subp);
15664 if Present (DTC_Entity (Actual_Subp)) then
15665 Set_DTC_Entity (New_Subp, DTC_Entity (Actual_Subp));
15666 Set_DT_Position_Value (New_Subp, DT_Position (Actual_Subp));
15667 end if;
15668 end if;
15670 -- Indicate that a derived subprogram does not require a body and that
15671 -- it does not require processing of default expressions.
15673 Set_Has_Completion (New_Subp);
15674 Set_Default_Expressions_Processed (New_Subp);
15676 if Ekind (New_Subp) = E_Function then
15677 Set_Mechanism (New_Subp, Mechanism (Parent_Subp));
15678 end if;
15679 end Derive_Subprogram;
15681 ------------------------
15682 -- Derive_Subprograms --
15683 ------------------------
15685 procedure Derive_Subprograms
15686 (Parent_Type : Entity_Id;
15687 Derived_Type : Entity_Id;
15688 Generic_Actual : Entity_Id := Empty)
15690 Op_List : constant Elist_Id :=
15691 Collect_Primitive_Operations (Parent_Type);
15693 function Check_Derived_Type return Boolean;
15694 -- Check that all the entities derived from Parent_Type are found in
15695 -- the list of primitives of Derived_Type exactly in the same order.
15697 procedure Derive_Interface_Subprogram
15698 (New_Subp : out Entity_Id;
15699 Subp : Entity_Id;
15700 Actual_Subp : Entity_Id);
15701 -- Derive New_Subp from the ultimate alias of the parent subprogram Subp
15702 -- (which is an interface primitive). If Generic_Actual is present then
15703 -- Actual_Subp is the actual subprogram corresponding with the generic
15704 -- subprogram Subp.
15706 ------------------------
15707 -- Check_Derived_Type --
15708 ------------------------
15710 function Check_Derived_Type return Boolean is
15711 E : Entity_Id;
15712 Elmt : Elmt_Id;
15713 List : Elist_Id;
15714 New_Subp : Entity_Id;
15715 Op_Elmt : Elmt_Id;
15716 Subp : Entity_Id;
15718 begin
15719 -- Traverse list of entities in the current scope searching for
15720 -- an incomplete type whose full-view is derived type.
15722 E := First_Entity (Scope (Derived_Type));
15723 while Present (E) and then E /= Derived_Type loop
15724 if Ekind (E) = E_Incomplete_Type
15725 and then Present (Full_View (E))
15726 and then Full_View (E) = Derived_Type
15727 then
15728 -- Disable this test if Derived_Type completes an incomplete
15729 -- type because in such case more primitives can be added
15730 -- later to the list of primitives of Derived_Type by routine
15731 -- Process_Incomplete_Dependents
15733 return True;
15734 end if;
15736 E := Next_Entity (E);
15737 end loop;
15739 List := Collect_Primitive_Operations (Derived_Type);
15740 Elmt := First_Elmt (List);
15742 Op_Elmt := First_Elmt (Op_List);
15743 while Present (Op_Elmt) loop
15744 Subp := Node (Op_Elmt);
15745 New_Subp := Node (Elmt);
15747 -- At this early stage Derived_Type has no entities with attribute
15748 -- Interface_Alias. In addition, such primitives are always
15749 -- located at the end of the list of primitives of Parent_Type.
15750 -- Therefore, if found we can safely stop processing pending
15751 -- entities.
15753 exit when Present (Interface_Alias (Subp));
15755 -- Handle hidden entities
15757 if not Is_Predefined_Dispatching_Operation (Subp)
15758 and then Is_Hidden (Subp)
15759 then
15760 if Present (New_Subp)
15761 and then Primitive_Names_Match (Subp, New_Subp)
15762 then
15763 Next_Elmt (Elmt);
15764 end if;
15766 else
15767 if not Present (New_Subp)
15768 or else Ekind (Subp) /= Ekind (New_Subp)
15769 or else not Primitive_Names_Match (Subp, New_Subp)
15770 then
15771 return False;
15772 end if;
15774 Next_Elmt (Elmt);
15775 end if;
15777 Next_Elmt (Op_Elmt);
15778 end loop;
15780 return True;
15781 end Check_Derived_Type;
15783 ---------------------------------
15784 -- Derive_Interface_Subprogram --
15785 ---------------------------------
15787 procedure Derive_Interface_Subprogram
15788 (New_Subp : out Entity_Id;
15789 Subp : Entity_Id;
15790 Actual_Subp : Entity_Id)
15792 Iface_Subp : constant Entity_Id := Ultimate_Alias (Subp);
15793 Iface_Type : constant Entity_Id := Find_Dispatching_Type (Iface_Subp);
15795 begin
15796 pragma Assert (Is_Interface (Iface_Type));
15798 Derive_Subprogram
15799 (New_Subp => New_Subp,
15800 Parent_Subp => Iface_Subp,
15801 Derived_Type => Derived_Type,
15802 Parent_Type => Iface_Type,
15803 Actual_Subp => Actual_Subp);
15805 -- Given that this new interface entity corresponds with a primitive
15806 -- of the parent that was not overridden we must leave it associated
15807 -- with its parent primitive to ensure that it will share the same
15808 -- dispatch table slot when overridden. We must set the Alias to Subp
15809 -- (instead of Iface_Subp), and we must fix Is_Abstract_Subprogram
15810 -- (in case we inherited Subp from Iface_Type via a nonabstract
15811 -- generic formal type).
15813 if No (Actual_Subp) then
15814 Set_Alias (New_Subp, Subp);
15816 declare
15817 T : Entity_Id := Find_Dispatching_Type (Subp);
15818 begin
15819 while Etype (T) /= T loop
15820 if Is_Generic_Type (T) and then not Is_Abstract_Type (T) then
15821 Set_Is_Abstract_Subprogram (New_Subp, False);
15822 exit;
15823 end if;
15825 T := Etype (T);
15826 end loop;
15827 end;
15829 -- For instantiations this is not needed since the previous call to
15830 -- Derive_Subprogram leaves the entity well decorated.
15832 else
15833 pragma Assert (Alias (New_Subp) = Actual_Subp);
15834 null;
15835 end if;
15836 end Derive_Interface_Subprogram;
15838 -- Local variables
15840 Alias_Subp : Entity_Id;
15841 Act_List : Elist_Id;
15842 Act_Elmt : Elmt_Id;
15843 Act_Subp : Entity_Id := Empty;
15844 Elmt : Elmt_Id;
15845 Need_Search : Boolean := False;
15846 New_Subp : Entity_Id := Empty;
15847 Parent_Base : Entity_Id;
15848 Subp : Entity_Id;
15850 -- Start of processing for Derive_Subprograms
15852 begin
15853 if Ekind (Parent_Type) = E_Record_Type_With_Private
15854 and then Has_Discriminants (Parent_Type)
15855 and then Present (Full_View (Parent_Type))
15856 then
15857 Parent_Base := Full_View (Parent_Type);
15858 else
15859 Parent_Base := Parent_Type;
15860 end if;
15862 if Present (Generic_Actual) then
15863 Act_List := Collect_Primitive_Operations (Generic_Actual);
15864 Act_Elmt := First_Elmt (Act_List);
15865 else
15866 Act_List := No_Elist;
15867 Act_Elmt := No_Elmt;
15868 end if;
15870 -- Derive primitives inherited from the parent. Note that if the generic
15871 -- actual is present, this is not really a type derivation, it is a
15872 -- completion within an instance.
15874 -- Case 1: Derived_Type does not implement interfaces
15876 if not Is_Tagged_Type (Derived_Type)
15877 or else (not Has_Interfaces (Derived_Type)
15878 and then not (Present (Generic_Actual)
15879 and then Has_Interfaces (Generic_Actual)))
15880 then
15881 Elmt := First_Elmt (Op_List);
15882 while Present (Elmt) loop
15883 Subp := Node (Elmt);
15885 -- Literals are derived earlier in the process of building the
15886 -- derived type, and are skipped here.
15888 if Ekind (Subp) = E_Enumeration_Literal then
15889 null;
15891 -- The actual is a direct descendant and the common primitive
15892 -- operations appear in the same order.
15894 -- If the generic parent type is present, the derived type is an
15895 -- instance of a formal derived type, and within the instance its
15896 -- operations are those of the actual. We derive from the formal
15897 -- type but make the inherited operations aliases of the
15898 -- corresponding operations of the actual.
15900 else
15901 pragma Assert (No (Node (Act_Elmt))
15902 or else (Primitive_Names_Match (Subp, Node (Act_Elmt))
15903 and then
15904 Type_Conformant
15905 (Subp, Node (Act_Elmt),
15906 Skip_Controlling_Formals => True)));
15908 Derive_Subprogram
15909 (New_Subp, Subp, Derived_Type, Parent_Base, Node (Act_Elmt));
15911 if Present (Act_Elmt) then
15912 Next_Elmt (Act_Elmt);
15913 end if;
15914 end if;
15916 Next_Elmt (Elmt);
15917 end loop;
15919 -- Case 2: Derived_Type implements interfaces
15921 else
15922 -- If the parent type has no predefined primitives we remove
15923 -- predefined primitives from the list of primitives of generic
15924 -- actual to simplify the complexity of this algorithm.
15926 if Present (Generic_Actual) then
15927 declare
15928 Has_Predefined_Primitives : Boolean := False;
15930 begin
15931 -- Check if the parent type has predefined primitives
15933 Elmt := First_Elmt (Op_List);
15934 while Present (Elmt) loop
15935 Subp := Node (Elmt);
15937 if Is_Predefined_Dispatching_Operation (Subp)
15938 and then not Comes_From_Source (Ultimate_Alias (Subp))
15939 then
15940 Has_Predefined_Primitives := True;
15941 exit;
15942 end if;
15944 Next_Elmt (Elmt);
15945 end loop;
15947 -- Remove predefined primitives of Generic_Actual. We must use
15948 -- an auxiliary list because in case of tagged types the value
15949 -- returned by Collect_Primitive_Operations is the value stored
15950 -- in its Primitive_Operations attribute (and we don't want to
15951 -- modify its current contents).
15953 if not Has_Predefined_Primitives then
15954 declare
15955 Aux_List : constant Elist_Id := New_Elmt_List;
15957 begin
15958 Elmt := First_Elmt (Act_List);
15959 while Present (Elmt) loop
15960 Subp := Node (Elmt);
15962 if not Is_Predefined_Dispatching_Operation (Subp)
15963 or else Comes_From_Source (Subp)
15964 then
15965 Append_Elmt (Subp, Aux_List);
15966 end if;
15968 Next_Elmt (Elmt);
15969 end loop;
15971 Act_List := Aux_List;
15972 end;
15973 end if;
15975 Act_Elmt := First_Elmt (Act_List);
15976 Act_Subp := Node (Act_Elmt);
15977 end;
15978 end if;
15980 -- Stage 1: If the generic actual is not present we derive the
15981 -- primitives inherited from the parent type. If the generic parent
15982 -- type is present, the derived type is an instance of a formal
15983 -- derived type, and within the instance its operations are those of
15984 -- the actual. We derive from the formal type but make the inherited
15985 -- operations aliases of the corresponding operations of the actual.
15987 Elmt := First_Elmt (Op_List);
15988 while Present (Elmt) loop
15989 Subp := Node (Elmt);
15990 Alias_Subp := Ultimate_Alias (Subp);
15992 -- Do not derive internal entities of the parent that link
15993 -- interface primitives with their covering primitive. These
15994 -- entities will be added to this type when frozen.
15996 if Present (Interface_Alias (Subp)) then
15997 goto Continue;
15998 end if;
16000 -- If the generic actual is present find the corresponding
16001 -- operation in the generic actual. If the parent type is a
16002 -- direct ancestor of the derived type then, even if it is an
16003 -- interface, the operations are inherited from the primary
16004 -- dispatch table and are in the proper order. If we detect here
16005 -- that primitives are not in the same order we traverse the list
16006 -- of primitive operations of the actual to find the one that
16007 -- implements the interface primitive.
16009 if Need_Search
16010 or else
16011 (Present (Generic_Actual)
16012 and then Present (Act_Subp)
16013 and then not
16014 (Primitive_Names_Match (Subp, Act_Subp)
16015 and then
16016 Type_Conformant (Subp, Act_Subp,
16017 Skip_Controlling_Formals => True)))
16018 then
16019 pragma Assert (not Is_Ancestor (Parent_Base, Generic_Actual,
16020 Use_Full_View => True));
16022 -- Remember that we need searching for all pending primitives
16024 Need_Search := True;
16026 -- Handle entities associated with interface primitives
16028 if Present (Alias_Subp)
16029 and then Is_Interface (Find_Dispatching_Type (Alias_Subp))
16030 and then not Is_Predefined_Dispatching_Operation (Subp)
16031 then
16032 -- Search for the primitive in the homonym chain
16034 Act_Subp :=
16035 Find_Primitive_Covering_Interface
16036 (Tagged_Type => Generic_Actual,
16037 Iface_Prim => Alias_Subp);
16039 -- Previous search may not locate primitives covering
16040 -- interfaces defined in generics units or instantiations.
16041 -- (it fails if the covering primitive has formals whose
16042 -- type is also defined in generics or instantiations).
16043 -- In such case we search in the list of primitives of the
16044 -- generic actual for the internal entity that links the
16045 -- interface primitive and the covering primitive.
16047 if No (Act_Subp)
16048 and then Is_Generic_Type (Parent_Type)
16049 then
16050 -- This code has been designed to handle only generic
16051 -- formals that implement interfaces that are defined
16052 -- in a generic unit or instantiation. If this code is
16053 -- needed for other cases we must review it because
16054 -- (given that it relies on Original_Location to locate
16055 -- the primitive of Generic_Actual that covers the
16056 -- interface) it could leave linked through attribute
16057 -- Alias entities of unrelated instantiations).
16059 pragma Assert
16060 (Is_Generic_Unit
16061 (Scope (Find_Dispatching_Type (Alias_Subp)))
16062 or else
16063 Instantiation_Depth
16064 (Sloc (Find_Dispatching_Type (Alias_Subp))) > 0);
16066 declare
16067 Iface_Prim_Loc : constant Source_Ptr :=
16068 Original_Location (Sloc (Alias_Subp));
16070 Elmt : Elmt_Id;
16071 Prim : Entity_Id;
16073 begin
16074 Elmt :=
16075 First_Elmt (Primitive_Operations (Generic_Actual));
16077 Search : while Present (Elmt) loop
16078 Prim := Node (Elmt);
16080 if Present (Interface_Alias (Prim))
16081 and then Original_Location
16082 (Sloc (Interface_Alias (Prim))) =
16083 Iface_Prim_Loc
16084 then
16085 Act_Subp := Alias (Prim);
16086 exit Search;
16087 end if;
16089 Next_Elmt (Elmt);
16090 end loop Search;
16091 end;
16092 end if;
16094 pragma Assert (Present (Act_Subp)
16095 or else Is_Abstract_Type (Generic_Actual)
16096 or else Serious_Errors_Detected > 0);
16098 -- Handle predefined primitives plus the rest of user-defined
16099 -- primitives
16101 else
16102 Act_Elmt := First_Elmt (Act_List);
16103 while Present (Act_Elmt) loop
16104 Act_Subp := Node (Act_Elmt);
16106 exit when Primitive_Names_Match (Subp, Act_Subp)
16107 and then Type_Conformant
16108 (Subp, Act_Subp,
16109 Skip_Controlling_Formals => True)
16110 and then No (Interface_Alias (Act_Subp));
16112 Next_Elmt (Act_Elmt);
16113 end loop;
16115 if No (Act_Elmt) then
16116 Act_Subp := Empty;
16117 end if;
16118 end if;
16119 end if;
16121 -- Case 1: If the parent is a limited interface then it has the
16122 -- predefined primitives of synchronized interfaces. However, the
16123 -- actual type may be a non-limited type and hence it does not
16124 -- have such primitives.
16126 if Present (Generic_Actual)
16127 and then not Present (Act_Subp)
16128 and then Is_Limited_Interface (Parent_Base)
16129 and then Is_Predefined_Interface_Primitive (Subp)
16130 then
16131 null;
16133 -- Case 2: Inherit entities associated with interfaces that were
16134 -- not covered by the parent type. We exclude here null interface
16135 -- primitives because they do not need special management.
16137 -- We also exclude interface operations that are renamings. If the
16138 -- subprogram is an explicit renaming of an interface primitive,
16139 -- it is a regular primitive operation, and the presence of its
16140 -- alias is not relevant: it has to be derived like any other
16141 -- primitive.
16143 elsif Present (Alias (Subp))
16144 and then Nkind (Unit_Declaration_Node (Subp)) /=
16145 N_Subprogram_Renaming_Declaration
16146 and then Is_Interface (Find_Dispatching_Type (Alias_Subp))
16147 and then not
16148 (Nkind (Parent (Alias_Subp)) = N_Procedure_Specification
16149 and then Null_Present (Parent (Alias_Subp)))
16150 then
16151 -- If this is an abstract private type then we transfer the
16152 -- derivation of the interface primitive from the partial view
16153 -- to the full view. This is safe because all the interfaces
16154 -- must be visible in the partial view. Done to avoid adding
16155 -- a new interface derivation to the private part of the
16156 -- enclosing package; otherwise this new derivation would be
16157 -- decorated as hidden when the analysis of the enclosing
16158 -- package completes.
16160 if Is_Abstract_Type (Derived_Type)
16161 and then In_Private_Part (Current_Scope)
16162 and then Has_Private_Declaration (Derived_Type)
16163 then
16164 declare
16165 Partial_View : Entity_Id;
16166 Elmt : Elmt_Id;
16167 Ent : Entity_Id;
16169 begin
16170 Partial_View := First_Entity (Current_Scope);
16171 loop
16172 exit when No (Partial_View)
16173 or else (Has_Private_Declaration (Partial_View)
16174 and then
16175 Full_View (Partial_View) = Derived_Type);
16177 Next_Entity (Partial_View);
16178 end loop;
16180 -- If the partial view was not found then the source code
16181 -- has errors and the derivation is not needed.
16183 if Present (Partial_View) then
16184 Elmt :=
16185 First_Elmt (Primitive_Operations (Partial_View));
16186 while Present (Elmt) loop
16187 Ent := Node (Elmt);
16189 if Present (Alias (Ent))
16190 and then Ultimate_Alias (Ent) = Alias (Subp)
16191 then
16192 Append_Elmt
16193 (Ent, Primitive_Operations (Derived_Type));
16194 exit;
16195 end if;
16197 Next_Elmt (Elmt);
16198 end loop;
16200 -- If the interface primitive was not found in the
16201 -- partial view then this interface primitive was
16202 -- overridden. We add a derivation to activate in
16203 -- Derive_Progenitor_Subprograms the machinery to
16204 -- search for it.
16206 if No (Elmt) then
16207 Derive_Interface_Subprogram
16208 (New_Subp => New_Subp,
16209 Subp => Subp,
16210 Actual_Subp => Act_Subp);
16211 end if;
16212 end if;
16213 end;
16214 else
16215 Derive_Interface_Subprogram
16216 (New_Subp => New_Subp,
16217 Subp => Subp,
16218 Actual_Subp => Act_Subp);
16219 end if;
16221 -- Case 3: Common derivation
16223 else
16224 Derive_Subprogram
16225 (New_Subp => New_Subp,
16226 Parent_Subp => Subp,
16227 Derived_Type => Derived_Type,
16228 Parent_Type => Parent_Base,
16229 Actual_Subp => Act_Subp);
16230 end if;
16232 -- No need to update Act_Elm if we must search for the
16233 -- corresponding operation in the generic actual
16235 if not Need_Search
16236 and then Present (Act_Elmt)
16237 then
16238 Next_Elmt (Act_Elmt);
16239 Act_Subp := Node (Act_Elmt);
16240 end if;
16242 <<Continue>>
16243 Next_Elmt (Elmt);
16244 end loop;
16246 -- Inherit additional operations from progenitors. If the derived
16247 -- type is a generic actual, there are not new primitive operations
16248 -- for the type because it has those of the actual, and therefore
16249 -- nothing needs to be done. The renamings generated above are not
16250 -- primitive operations, and their purpose is simply to make the
16251 -- proper operations visible within an instantiation.
16253 if No (Generic_Actual) then
16254 Derive_Progenitor_Subprograms (Parent_Base, Derived_Type);
16255 end if;
16256 end if;
16258 -- Final check: Direct descendants must have their primitives in the
16259 -- same order. We exclude from this test untagged types and instances
16260 -- of formal derived types. We skip this test if we have already
16261 -- reported serious errors in the sources.
16263 pragma Assert (not Is_Tagged_Type (Derived_Type)
16264 or else Present (Generic_Actual)
16265 or else Serious_Errors_Detected > 0
16266 or else Check_Derived_Type);
16267 end Derive_Subprograms;
16269 --------------------------------
16270 -- Derived_Standard_Character --
16271 --------------------------------
16273 procedure Derived_Standard_Character
16274 (N : Node_Id;
16275 Parent_Type : Entity_Id;
16276 Derived_Type : Entity_Id)
16278 Loc : constant Source_Ptr := Sloc (N);
16279 Def : constant Node_Id := Type_Definition (N);
16280 Indic : constant Node_Id := Subtype_Indication (Def);
16281 Parent_Base : constant Entity_Id := Base_Type (Parent_Type);
16282 Implicit_Base : constant Entity_Id :=
16283 Create_Itype
16284 (E_Enumeration_Type, N, Derived_Type, 'B');
16286 Lo : Node_Id;
16287 Hi : Node_Id;
16289 begin
16290 Discard_Node (Process_Subtype (Indic, N));
16292 Set_Etype (Implicit_Base, Parent_Base);
16293 Set_Size_Info (Implicit_Base, Root_Type (Parent_Type));
16294 Set_RM_Size (Implicit_Base, RM_Size (Root_Type (Parent_Type)));
16296 Set_Is_Character_Type (Implicit_Base, True);
16297 Set_Has_Delayed_Freeze (Implicit_Base);
16299 -- The bounds of the implicit base are the bounds of the parent base.
16300 -- Note that their type is the parent base.
16302 Lo := New_Copy_Tree (Type_Low_Bound (Parent_Base));
16303 Hi := New_Copy_Tree (Type_High_Bound (Parent_Base));
16305 Set_Scalar_Range (Implicit_Base,
16306 Make_Range (Loc,
16307 Low_Bound => Lo,
16308 High_Bound => Hi));
16310 Conditional_Delay (Derived_Type, Parent_Type);
16312 Set_Ekind (Derived_Type, E_Enumeration_Subtype);
16313 Set_Etype (Derived_Type, Implicit_Base);
16314 Set_Size_Info (Derived_Type, Parent_Type);
16316 if Unknown_RM_Size (Derived_Type) then
16317 Set_RM_Size (Derived_Type, RM_Size (Parent_Type));
16318 end if;
16320 Set_Is_Character_Type (Derived_Type, True);
16322 if Nkind (Indic) /= N_Subtype_Indication then
16324 -- If no explicit constraint, the bounds are those
16325 -- of the parent type.
16327 Lo := New_Copy_Tree (Type_Low_Bound (Parent_Type));
16328 Hi := New_Copy_Tree (Type_High_Bound (Parent_Type));
16329 Set_Scalar_Range (Derived_Type, Make_Range (Loc, Lo, Hi));
16330 end if;
16332 Convert_Scalar_Bounds (N, Parent_Type, Derived_Type, Loc);
16334 -- Because the implicit base is used in the conversion of the bounds, we
16335 -- have to freeze it now. This is similar to what is done for numeric
16336 -- types, and it equally suspicious, but otherwise a non-static bound
16337 -- will have a reference to an unfrozen type, which is rejected by Gigi
16338 -- (???). This requires specific care for definition of stream
16339 -- attributes. For details, see comments at the end of
16340 -- Build_Derived_Numeric_Type.
16342 Freeze_Before (N, Implicit_Base);
16343 end Derived_Standard_Character;
16345 ------------------------------
16346 -- Derived_Type_Declaration --
16347 ------------------------------
16349 procedure Derived_Type_Declaration
16350 (T : Entity_Id;
16351 N : Node_Id;
16352 Is_Completion : Boolean)
16354 Parent_Type : Entity_Id;
16356 function Comes_From_Generic (Typ : Entity_Id) return Boolean;
16357 -- Check whether the parent type is a generic formal, or derives
16358 -- directly or indirectly from one.
16360 ------------------------
16361 -- Comes_From_Generic --
16362 ------------------------
16364 function Comes_From_Generic (Typ : Entity_Id) return Boolean is
16365 begin
16366 if Is_Generic_Type (Typ) then
16367 return True;
16369 elsif Is_Generic_Type (Root_Type (Parent_Type)) then
16370 return True;
16372 elsif Is_Private_Type (Typ)
16373 and then Present (Full_View (Typ))
16374 and then Is_Generic_Type (Root_Type (Full_View (Typ)))
16375 then
16376 return True;
16378 elsif Is_Generic_Actual_Type (Typ) then
16379 return True;
16381 else
16382 return False;
16383 end if;
16384 end Comes_From_Generic;
16386 -- Local variables
16388 Def : constant Node_Id := Type_Definition (N);
16389 Iface_Def : Node_Id;
16390 Indic : constant Node_Id := Subtype_Indication (Def);
16391 Extension : constant Node_Id := Record_Extension_Part (Def);
16392 Parent_Node : Node_Id;
16393 Taggd : Boolean;
16395 -- Start of processing for Derived_Type_Declaration
16397 begin
16398 Parent_Type := Find_Type_Of_Subtype_Indic (Indic);
16400 if SPARK_Mode = On
16401 and then Is_Tagged_Type (Parent_Type)
16402 then
16403 declare
16404 Partial_View : constant Entity_Id :=
16405 Incomplete_Or_Partial_View (Parent_Type);
16407 begin
16408 -- If the partial view was not found then the parent type is not
16409 -- a private type. Otherwise check if the partial view is a tagged
16410 -- private type.
16412 if Present (Partial_View)
16413 and then Is_Private_Type (Partial_View)
16414 and then not Is_Tagged_Type (Partial_View)
16415 then
16416 Error_Msg_NE
16417 ("cannot derive from & declared as untagged private "
16418 & "(SPARK RM 3.4(1))", N, Partial_View);
16419 end if;
16420 end;
16421 end if;
16423 -- Ada 2005 (AI-251): In case of interface derivation check that the
16424 -- parent is also an interface.
16426 if Interface_Present (Def) then
16427 Check_SPARK_05_Restriction ("interface is not allowed", Def);
16429 if not Is_Interface (Parent_Type) then
16430 Diagnose_Interface (Indic, Parent_Type);
16432 else
16433 Parent_Node := Parent (Base_Type (Parent_Type));
16434 Iface_Def := Type_Definition (Parent_Node);
16436 -- Ada 2005 (AI-251): Limited interfaces can only inherit from
16437 -- other limited interfaces.
16439 if Limited_Present (Def) then
16440 if Limited_Present (Iface_Def) then
16441 null;
16443 elsif Protected_Present (Iface_Def) then
16444 Error_Msg_NE
16445 ("descendant of & must be declared as a protected "
16446 & "interface", N, Parent_Type);
16448 elsif Synchronized_Present (Iface_Def) then
16449 Error_Msg_NE
16450 ("descendant of & must be declared as a synchronized "
16451 & "interface", N, Parent_Type);
16453 elsif Task_Present (Iface_Def) then
16454 Error_Msg_NE
16455 ("descendant of & must be declared as a task interface",
16456 N, Parent_Type);
16458 else
16459 Error_Msg_N
16460 ("(Ada 2005) limited interface cannot inherit from "
16461 & "non-limited interface", Indic);
16462 end if;
16464 -- Ada 2005 (AI-345): Non-limited interfaces can only inherit
16465 -- from non-limited or limited interfaces.
16467 elsif not Protected_Present (Def)
16468 and then not Synchronized_Present (Def)
16469 and then not Task_Present (Def)
16470 then
16471 if Limited_Present (Iface_Def) then
16472 null;
16474 elsif Protected_Present (Iface_Def) then
16475 Error_Msg_NE
16476 ("descendant of & must be declared as a protected "
16477 & "interface", N, Parent_Type);
16479 elsif Synchronized_Present (Iface_Def) then
16480 Error_Msg_NE
16481 ("descendant of & must be declared as a synchronized "
16482 & "interface", N, Parent_Type);
16484 elsif Task_Present (Iface_Def) then
16485 Error_Msg_NE
16486 ("descendant of & must be declared as a task interface",
16487 N, Parent_Type);
16488 else
16489 null;
16490 end if;
16491 end if;
16492 end if;
16493 end if;
16495 if Is_Tagged_Type (Parent_Type)
16496 and then Is_Concurrent_Type (Parent_Type)
16497 and then not Is_Interface (Parent_Type)
16498 then
16499 Error_Msg_N
16500 ("parent type of a record extension cannot be a synchronized "
16501 & "tagged type (RM 3.9.1 (3/1))", N);
16502 Set_Etype (T, Any_Type);
16503 return;
16504 end if;
16506 -- Ada 2005 (AI-251): Decorate all the names in the list of ancestor
16507 -- interfaces
16509 if Is_Tagged_Type (Parent_Type)
16510 and then Is_Non_Empty_List (Interface_List (Def))
16511 then
16512 declare
16513 Intf : Node_Id;
16514 T : Entity_Id;
16516 begin
16517 Intf := First (Interface_List (Def));
16518 while Present (Intf) loop
16519 T := Find_Type_Of_Subtype_Indic (Intf);
16521 if not Is_Interface (T) then
16522 Diagnose_Interface (Intf, T);
16524 -- Check the rules of 3.9.4(12/2) and 7.5(2/2) that disallow
16525 -- a limited type from having a nonlimited progenitor.
16527 elsif (Limited_Present (Def)
16528 or else (not Is_Interface (Parent_Type)
16529 and then Is_Limited_Type (Parent_Type)))
16530 and then not Is_Limited_Interface (T)
16531 then
16532 Error_Msg_NE
16533 ("progenitor interface& of limited type must be limited",
16534 N, T);
16535 end if;
16537 Next (Intf);
16538 end loop;
16539 end;
16540 end if;
16542 if Parent_Type = Any_Type
16543 or else Etype (Parent_Type) = Any_Type
16544 or else (Is_Class_Wide_Type (Parent_Type)
16545 and then Etype (Parent_Type) = T)
16546 then
16547 -- If Parent_Type is undefined or illegal, make new type into a
16548 -- subtype of Any_Type, and set a few attributes to prevent cascaded
16549 -- errors. If this is a self-definition, emit error now.
16551 if T = Parent_Type or else T = Etype (Parent_Type) then
16552 Error_Msg_N ("type cannot be used in its own definition", Indic);
16553 end if;
16555 Set_Ekind (T, Ekind (Parent_Type));
16556 Set_Etype (T, Any_Type);
16557 Set_Scalar_Range (T, Scalar_Range (Any_Type));
16559 if Is_Tagged_Type (T)
16560 and then Is_Record_Type (T)
16561 then
16562 Set_Direct_Primitive_Operations (T, New_Elmt_List);
16563 end if;
16565 return;
16566 end if;
16568 -- Ada 2005 (AI-251): The case in which the parent of the full-view is
16569 -- an interface is special because the list of interfaces in the full
16570 -- view can be given in any order. For example:
16572 -- type A is interface;
16573 -- type B is interface and A;
16574 -- type D is new B with private;
16575 -- private
16576 -- type D is new A and B with null record; -- 1 --
16578 -- In this case we perform the following transformation of -1-:
16580 -- type D is new B and A with null record;
16582 -- If the parent of the full-view covers the parent of the partial-view
16583 -- we have two possible cases:
16585 -- 1) They have the same parent
16586 -- 2) The parent of the full-view implements some further interfaces
16588 -- In both cases we do not need to perform the transformation. In the
16589 -- first case the source program is correct and the transformation is
16590 -- not needed; in the second case the source program does not fulfill
16591 -- the no-hidden interfaces rule (AI-396) and the error will be reported
16592 -- later.
16594 -- This transformation not only simplifies the rest of the analysis of
16595 -- this type declaration but also simplifies the correct generation of
16596 -- the object layout to the expander.
16598 if In_Private_Part (Current_Scope)
16599 and then Is_Interface (Parent_Type)
16600 then
16601 declare
16602 Iface : Node_Id;
16603 Partial_View : Entity_Id;
16604 Partial_View_Parent : Entity_Id;
16605 New_Iface : Node_Id;
16607 begin
16608 -- Look for the associated private type declaration
16610 Partial_View := Incomplete_Or_Partial_View (T);
16612 -- If the partial view was not found then the source code has
16613 -- errors and the transformation is not needed.
16615 if Present (Partial_View) then
16616 Partial_View_Parent := Etype (Partial_View);
16618 -- If the parent of the full-view covers the parent of the
16619 -- partial-view we have nothing else to do.
16621 if Interface_Present_In_Ancestor
16622 (Parent_Type, Partial_View_Parent)
16623 then
16624 null;
16626 -- Traverse the list of interfaces of the full-view to look
16627 -- for the parent of the partial-view and perform the tree
16628 -- transformation.
16630 else
16631 Iface := First (Interface_List (Def));
16632 while Present (Iface) loop
16633 if Etype (Iface) = Etype (Partial_View) then
16634 Rewrite (Subtype_Indication (Def),
16635 New_Copy (Subtype_Indication
16636 (Parent (Partial_View))));
16638 New_Iface :=
16639 Make_Identifier (Sloc (N), Chars (Parent_Type));
16640 Append (New_Iface, Interface_List (Def));
16642 -- Analyze the transformed code
16644 Derived_Type_Declaration (T, N, Is_Completion);
16645 return;
16646 end if;
16648 Next (Iface);
16649 end loop;
16650 end if;
16651 end if;
16652 end;
16653 end if;
16655 -- Only composite types other than array types are allowed to have
16656 -- discriminants.
16658 if Present (Discriminant_Specifications (N)) then
16659 if (Is_Elementary_Type (Parent_Type)
16660 or else
16661 Is_Array_Type (Parent_Type))
16662 and then not Error_Posted (N)
16663 then
16664 Error_Msg_N
16665 ("elementary or array type cannot have discriminants",
16666 Defining_Identifier (First (Discriminant_Specifications (N))));
16667 Set_Has_Discriminants (T, False);
16669 -- The type is allowed to have discriminants
16671 else
16672 Check_SPARK_05_Restriction ("discriminant type is not allowed", N);
16673 end if;
16674 end if;
16676 -- In Ada 83, a derived type defined in a package specification cannot
16677 -- be used for further derivation until the end of its visible part.
16678 -- Note that derivation in the private part of the package is allowed.
16680 if Ada_Version = Ada_83
16681 and then Is_Derived_Type (Parent_Type)
16682 and then In_Visible_Part (Scope (Parent_Type))
16683 then
16684 if Ada_Version = Ada_83 and then Comes_From_Source (Indic) then
16685 Error_Msg_N
16686 ("(Ada 83): premature use of type for derivation", Indic);
16687 end if;
16688 end if;
16690 -- Check for early use of incomplete or private type
16692 if Ekind_In (Parent_Type, E_Void, E_Incomplete_Type) then
16693 Error_Msg_N ("premature derivation of incomplete type", Indic);
16694 return;
16696 elsif (Is_Incomplete_Or_Private_Type (Parent_Type)
16697 and then not Comes_From_Generic (Parent_Type))
16698 or else Has_Private_Component (Parent_Type)
16699 then
16700 -- The ancestor type of a formal type can be incomplete, in which
16701 -- case only the operations of the partial view are available in the
16702 -- generic. Subsequent checks may be required when the full view is
16703 -- analyzed to verify that a derivation from a tagged type has an
16704 -- extension.
16706 if Nkind (Original_Node (N)) = N_Formal_Type_Declaration then
16707 null;
16709 elsif No (Underlying_Type (Parent_Type))
16710 or else Has_Private_Component (Parent_Type)
16711 then
16712 Error_Msg_N
16713 ("premature derivation of derived or private type", Indic);
16715 -- Flag the type itself as being in error, this prevents some
16716 -- nasty problems with subsequent uses of the malformed type.
16718 Set_Error_Posted (T);
16720 -- Check that within the immediate scope of an untagged partial
16721 -- view it's illegal to derive from the partial view if the
16722 -- full view is tagged. (7.3(7))
16724 -- We verify that the Parent_Type is a partial view by checking
16725 -- that it is not a Full_Type_Declaration (i.e. a private type or
16726 -- private extension declaration), to distinguish a partial view
16727 -- from a derivation from a private type which also appears as
16728 -- E_Private_Type. If the parent base type is not declared in an
16729 -- enclosing scope there is no need to check.
16731 elsif Present (Full_View (Parent_Type))
16732 and then Nkind (Parent (Parent_Type)) /= N_Full_Type_Declaration
16733 and then not Is_Tagged_Type (Parent_Type)
16734 and then Is_Tagged_Type (Full_View (Parent_Type))
16735 and then In_Open_Scopes (Scope (Base_Type (Parent_Type)))
16736 then
16737 Error_Msg_N
16738 ("premature derivation from type with tagged full view",
16739 Indic);
16740 end if;
16741 end if;
16743 -- Check that form of derivation is appropriate
16745 Taggd := Is_Tagged_Type (Parent_Type);
16747 -- Set the parent type to the class-wide type's specific type in this
16748 -- case to prevent cascading errors
16750 if Present (Extension) and then Is_Class_Wide_Type (Parent_Type) then
16751 Error_Msg_N ("parent type must not be a class-wide type", Indic);
16752 Set_Etype (T, Etype (Parent_Type));
16753 return;
16754 end if;
16756 if Present (Extension) and then not Taggd then
16757 Error_Msg_N
16758 ("type derived from untagged type cannot have extension", Indic);
16760 elsif No (Extension) and then Taggd then
16762 -- If this declaration is within a private part (or body) of a
16763 -- generic instantiation then the derivation is allowed (the parent
16764 -- type can only appear tagged in this case if it's a generic actual
16765 -- type, since it would otherwise have been rejected in the analysis
16766 -- of the generic template).
16768 if not Is_Generic_Actual_Type (Parent_Type)
16769 or else In_Visible_Part (Scope (Parent_Type))
16770 then
16771 if Is_Class_Wide_Type (Parent_Type) then
16772 Error_Msg_N
16773 ("parent type must not be a class-wide type", Indic);
16775 -- Use specific type to prevent cascaded errors.
16777 Parent_Type := Etype (Parent_Type);
16779 else
16780 Error_Msg_N
16781 ("type derived from tagged type must have extension", Indic);
16782 end if;
16783 end if;
16784 end if;
16786 -- AI-443: Synchronized formal derived types require a private
16787 -- extension. There is no point in checking the ancestor type or
16788 -- the progenitors since the construct is wrong to begin with.
16790 if Ada_Version >= Ada_2005
16791 and then Is_Generic_Type (T)
16792 and then Present (Original_Node (N))
16793 then
16794 declare
16795 Decl : constant Node_Id := Original_Node (N);
16797 begin
16798 if Nkind (Decl) = N_Formal_Type_Declaration
16799 and then Nkind (Formal_Type_Definition (Decl)) =
16800 N_Formal_Derived_Type_Definition
16801 and then Synchronized_Present (Formal_Type_Definition (Decl))
16802 and then No (Extension)
16804 -- Avoid emitting a duplicate error message
16806 and then not Error_Posted (Indic)
16807 then
16808 Error_Msg_N
16809 ("synchronized derived type must have extension", N);
16810 end if;
16811 end;
16812 end if;
16814 if Null_Exclusion_Present (Def)
16815 and then not Is_Access_Type (Parent_Type)
16816 then
16817 Error_Msg_N ("null exclusion can only apply to an access type", N);
16818 end if;
16820 -- Avoid deriving parent primitives of underlying record views
16822 Build_Derived_Type (N, Parent_Type, T, Is_Completion,
16823 Derive_Subps => not Is_Underlying_Record_View (T));
16825 -- AI-419: The parent type of an explicitly limited derived type must
16826 -- be a limited type or a limited interface.
16828 if Limited_Present (Def) then
16829 Set_Is_Limited_Record (T);
16831 if Is_Interface (T) then
16832 Set_Is_Limited_Interface (T);
16833 end if;
16835 if not Is_Limited_Type (Parent_Type)
16836 and then
16837 (not Is_Interface (Parent_Type)
16838 or else not Is_Limited_Interface (Parent_Type))
16839 then
16840 -- AI05-0096: a derivation in the private part of an instance is
16841 -- legal if the generic formal is untagged limited, and the actual
16842 -- is non-limited.
16844 if Is_Generic_Actual_Type (Parent_Type)
16845 and then In_Private_Part (Current_Scope)
16846 and then
16847 not Is_Tagged_Type
16848 (Generic_Parent_Type (Parent (Parent_Type)))
16849 then
16850 null;
16852 else
16853 Error_Msg_NE
16854 ("parent type& of limited type must be limited",
16855 N, Parent_Type);
16856 end if;
16857 end if;
16858 end if;
16860 -- In SPARK, there are no derived type definitions other than type
16861 -- extensions of tagged record types.
16863 if No (Extension) then
16864 Check_SPARK_05_Restriction
16865 ("derived type is not allowed", Original_Node (N));
16866 end if;
16867 end Derived_Type_Declaration;
16869 ------------------------
16870 -- Diagnose_Interface --
16871 ------------------------
16873 procedure Diagnose_Interface (N : Node_Id; E : Entity_Id) is
16874 begin
16875 if not Is_Interface (E) and then E /= Any_Type then
16876 Error_Msg_NE ("(Ada 2005) & must be an interface", N, E);
16877 end if;
16878 end Diagnose_Interface;
16880 ----------------------------------
16881 -- Enumeration_Type_Declaration --
16882 ----------------------------------
16884 procedure Enumeration_Type_Declaration (T : Entity_Id; Def : Node_Id) is
16885 Ev : Uint;
16886 L : Node_Id;
16887 R_Node : Node_Id;
16888 B_Node : Node_Id;
16890 begin
16891 -- Create identifier node representing lower bound
16893 B_Node := New_Node (N_Identifier, Sloc (Def));
16894 L := First (Literals (Def));
16895 Set_Chars (B_Node, Chars (L));
16896 Set_Entity (B_Node, L);
16897 Set_Etype (B_Node, T);
16898 Set_Is_Static_Expression (B_Node, True);
16900 R_Node := New_Node (N_Range, Sloc (Def));
16901 Set_Low_Bound (R_Node, B_Node);
16903 Set_Ekind (T, E_Enumeration_Type);
16904 Set_First_Literal (T, L);
16905 Set_Etype (T, T);
16906 Set_Is_Constrained (T);
16908 Ev := Uint_0;
16910 -- Loop through literals of enumeration type setting pos and rep values
16911 -- except that if the Ekind is already set, then it means the literal
16912 -- was already constructed (case of a derived type declaration and we
16913 -- should not disturb the Pos and Rep values.
16915 while Present (L) loop
16916 if Ekind (L) /= E_Enumeration_Literal then
16917 Set_Ekind (L, E_Enumeration_Literal);
16918 Set_Enumeration_Pos (L, Ev);
16919 Set_Enumeration_Rep (L, Ev);
16920 Set_Is_Known_Valid (L, True);
16921 end if;
16923 Set_Etype (L, T);
16924 New_Overloaded_Entity (L);
16925 Generate_Definition (L);
16926 Set_Convention (L, Convention_Intrinsic);
16928 -- Case of character literal
16930 if Nkind (L) = N_Defining_Character_Literal then
16931 Set_Is_Character_Type (T, True);
16933 -- Check violation of No_Wide_Characters
16935 if Restriction_Check_Required (No_Wide_Characters) then
16936 Get_Name_String (Chars (L));
16938 if Name_Len >= 3 and then Name_Buffer (1 .. 2) = "QW" then
16939 Check_Restriction (No_Wide_Characters, L);
16940 end if;
16941 end if;
16942 end if;
16944 Ev := Ev + 1;
16945 Next (L);
16946 end loop;
16948 -- Now create a node representing upper bound
16950 B_Node := New_Node (N_Identifier, Sloc (Def));
16951 Set_Chars (B_Node, Chars (Last (Literals (Def))));
16952 Set_Entity (B_Node, Last (Literals (Def)));
16953 Set_Etype (B_Node, T);
16954 Set_Is_Static_Expression (B_Node, True);
16956 Set_High_Bound (R_Node, B_Node);
16958 -- Initialize various fields of the type. Some of this information
16959 -- may be overwritten later through rep.clauses.
16961 Set_Scalar_Range (T, R_Node);
16962 Set_RM_Size (T, UI_From_Int (Minimum_Size (T)));
16963 Set_Enum_Esize (T);
16964 Set_Enum_Pos_To_Rep (T, Empty);
16966 -- Set Discard_Names if configuration pragma set, or if there is
16967 -- a parameterless pragma in the current declarative region
16969 if Global_Discard_Names or else Discard_Names (Scope (T)) then
16970 Set_Discard_Names (T);
16971 end if;
16973 -- Process end label if there is one
16975 if Present (Def) then
16976 Process_End_Label (Def, 'e', T);
16977 end if;
16978 end Enumeration_Type_Declaration;
16980 ---------------------------------
16981 -- Expand_To_Stored_Constraint --
16982 ---------------------------------
16984 function Expand_To_Stored_Constraint
16985 (Typ : Entity_Id;
16986 Constraint : Elist_Id) return Elist_Id
16988 Explicitly_Discriminated_Type : Entity_Id;
16989 Expansion : Elist_Id;
16990 Discriminant : Entity_Id;
16992 function Type_With_Explicit_Discrims (Id : Entity_Id) return Entity_Id;
16993 -- Find the nearest type that actually specifies discriminants
16995 ---------------------------------
16996 -- Type_With_Explicit_Discrims --
16997 ---------------------------------
16999 function Type_With_Explicit_Discrims (Id : Entity_Id) return Entity_Id is
17000 Typ : constant E := Base_Type (Id);
17002 begin
17003 if Ekind (Typ) in Incomplete_Or_Private_Kind then
17004 if Present (Full_View (Typ)) then
17005 return Type_With_Explicit_Discrims (Full_View (Typ));
17006 end if;
17008 else
17009 if Has_Discriminants (Typ) then
17010 return Typ;
17011 end if;
17012 end if;
17014 if Etype (Typ) = Typ then
17015 return Empty;
17016 elsif Has_Discriminants (Typ) then
17017 return Typ;
17018 else
17019 return Type_With_Explicit_Discrims (Etype (Typ));
17020 end if;
17022 end Type_With_Explicit_Discrims;
17024 -- Start of processing for Expand_To_Stored_Constraint
17026 begin
17027 if No (Constraint) or else Is_Empty_Elmt_List (Constraint) then
17028 return No_Elist;
17029 end if;
17031 Explicitly_Discriminated_Type := Type_With_Explicit_Discrims (Typ);
17033 if No (Explicitly_Discriminated_Type) then
17034 return No_Elist;
17035 end if;
17037 Expansion := New_Elmt_List;
17039 Discriminant :=
17040 First_Stored_Discriminant (Explicitly_Discriminated_Type);
17041 while Present (Discriminant) loop
17042 Append_Elmt
17043 (Get_Discriminant_Value
17044 (Discriminant, Explicitly_Discriminated_Type, Constraint),
17045 To => Expansion);
17046 Next_Stored_Discriminant (Discriminant);
17047 end loop;
17049 return Expansion;
17050 end Expand_To_Stored_Constraint;
17052 ---------------------------
17053 -- Find_Hidden_Interface --
17054 ---------------------------
17056 function Find_Hidden_Interface
17057 (Src : Elist_Id;
17058 Dest : Elist_Id) return Entity_Id
17060 Iface : Entity_Id;
17061 Iface_Elmt : Elmt_Id;
17063 begin
17064 if Present (Src) and then Present (Dest) then
17065 Iface_Elmt := First_Elmt (Src);
17066 while Present (Iface_Elmt) loop
17067 Iface := Node (Iface_Elmt);
17069 if Is_Interface (Iface)
17070 and then not Contain_Interface (Iface, Dest)
17071 then
17072 return Iface;
17073 end if;
17075 Next_Elmt (Iface_Elmt);
17076 end loop;
17077 end if;
17079 return Empty;
17080 end Find_Hidden_Interface;
17082 --------------------
17083 -- Find_Type_Name --
17084 --------------------
17086 function Find_Type_Name (N : Node_Id) return Entity_Id is
17087 Id : constant Entity_Id := Defining_Identifier (N);
17088 New_Id : Entity_Id;
17089 Prev : Entity_Id;
17090 Prev_Par : Node_Id;
17092 procedure Check_Duplicate_Aspects;
17093 -- Check that aspects specified in a completion have not been specified
17094 -- already in the partial view.
17096 procedure Tag_Mismatch;
17097 -- Diagnose a tagged partial view whose full view is untagged. We post
17098 -- the message on the full view, with a reference to the previous
17099 -- partial view. The partial view can be private or incomplete, and
17100 -- these are handled in a different manner, so we determine the position
17101 -- of the error message from the respective slocs of both.
17103 -----------------------------
17104 -- Check_Duplicate_Aspects --
17105 -----------------------------
17107 procedure Check_Duplicate_Aspects is
17108 function Get_Partial_View_Aspect (Asp : Node_Id) return Node_Id;
17109 -- Return the corresponding aspect of the partial view which matches
17110 -- the aspect id of Asp. Return Empty is no such aspect exists.
17112 -----------------------------
17113 -- Get_Partial_View_Aspect --
17114 -----------------------------
17116 function Get_Partial_View_Aspect (Asp : Node_Id) return Node_Id is
17117 Asp_Id : constant Aspect_Id := Get_Aspect_Id (Asp);
17118 Prev_Asps : constant List_Id := Aspect_Specifications (Prev_Par);
17119 Prev_Asp : Node_Id;
17121 begin
17122 if Present (Prev_Asps) then
17123 Prev_Asp := First (Prev_Asps);
17124 while Present (Prev_Asp) loop
17125 if Get_Aspect_Id (Prev_Asp) = Asp_Id then
17126 return Prev_Asp;
17127 end if;
17129 Next (Prev_Asp);
17130 end loop;
17131 end if;
17133 return Empty;
17134 end Get_Partial_View_Aspect;
17136 -- Local variables
17138 Full_Asps : constant List_Id := Aspect_Specifications (N);
17139 Full_Asp : Node_Id;
17140 Part_Asp : Node_Id;
17142 -- Start of processing for Check_Duplicate_Aspects
17144 begin
17145 if Present (Full_Asps) then
17146 Full_Asp := First (Full_Asps);
17147 while Present (Full_Asp) loop
17148 Part_Asp := Get_Partial_View_Aspect (Full_Asp);
17150 -- An aspect and its class-wide counterpart are two distinct
17151 -- aspects and may apply to both views of an entity.
17153 if Present (Part_Asp)
17154 and then Class_Present (Part_Asp) = Class_Present (Full_Asp)
17155 then
17156 Error_Msg_N
17157 ("aspect already specified in private declaration",
17158 Full_Asp);
17160 Remove (Full_Asp);
17161 return;
17162 end if;
17164 if Has_Discriminants (Prev)
17165 and then not Has_Unknown_Discriminants (Prev)
17166 and then Get_Aspect_Id (Full_Asp) =
17167 Aspect_Implicit_Dereference
17168 then
17169 Error_Msg_N
17170 ("cannot specify aspect if partial view has known "
17171 & "discriminants", Full_Asp);
17172 end if;
17174 Next (Full_Asp);
17175 end loop;
17176 end if;
17177 end Check_Duplicate_Aspects;
17179 ------------------
17180 -- Tag_Mismatch --
17181 ------------------
17183 procedure Tag_Mismatch is
17184 begin
17185 if Sloc (Prev) < Sloc (Id) then
17186 if Ada_Version >= Ada_2012
17187 and then Nkind (N) = N_Private_Type_Declaration
17188 then
17189 Error_Msg_NE
17190 ("declaration of private } must be a tagged type ", Id, Prev);
17191 else
17192 Error_Msg_NE
17193 ("full declaration of } must be a tagged type ", Id, Prev);
17194 end if;
17196 else
17197 if Ada_Version >= Ada_2012
17198 and then Nkind (N) = N_Private_Type_Declaration
17199 then
17200 Error_Msg_NE
17201 ("declaration of private } must be a tagged type ", Prev, Id);
17202 else
17203 Error_Msg_NE
17204 ("full declaration of } must be a tagged type ", Prev, Id);
17205 end if;
17206 end if;
17207 end Tag_Mismatch;
17209 -- Start of processing for Find_Type_Name
17211 begin
17212 -- Find incomplete declaration, if one was given
17214 Prev := Current_Entity_In_Scope (Id);
17216 -- New type declaration
17218 if No (Prev) then
17219 Enter_Name (Id);
17220 return Id;
17222 -- Previous declaration exists
17224 else
17225 Prev_Par := Parent (Prev);
17227 -- Error if not incomplete/private case except if previous
17228 -- declaration is implicit, etc. Enter_Name will emit error if
17229 -- appropriate.
17231 if not Is_Incomplete_Or_Private_Type (Prev) then
17232 Enter_Name (Id);
17233 New_Id := Id;
17235 -- Check invalid completion of private or incomplete type
17237 elsif not Nkind_In (N, N_Full_Type_Declaration,
17238 N_Task_Type_Declaration,
17239 N_Protected_Type_Declaration)
17240 and then
17241 (Ada_Version < Ada_2012
17242 or else not Is_Incomplete_Type (Prev)
17243 or else not Nkind_In (N, N_Private_Type_Declaration,
17244 N_Private_Extension_Declaration))
17245 then
17246 -- Completion must be a full type declarations (RM 7.3(4))
17248 Error_Msg_Sloc := Sloc (Prev);
17249 Error_Msg_NE ("invalid completion of }", Id, Prev);
17251 -- Set scope of Id to avoid cascaded errors. Entity is never
17252 -- examined again, except when saving globals in generics.
17254 Set_Scope (Id, Current_Scope);
17255 New_Id := Id;
17257 -- If this is a repeated incomplete declaration, no further
17258 -- checks are possible.
17260 if Nkind (N) = N_Incomplete_Type_Declaration then
17261 return Prev;
17262 end if;
17264 -- Case of full declaration of incomplete type
17266 elsif Ekind (Prev) = E_Incomplete_Type
17267 and then (Ada_Version < Ada_2012
17268 or else No (Full_View (Prev))
17269 or else not Is_Private_Type (Full_View (Prev)))
17270 then
17271 -- Indicate that the incomplete declaration has a matching full
17272 -- declaration. The defining occurrence of the incomplete
17273 -- declaration remains the visible one, and the procedure
17274 -- Get_Full_View dereferences it whenever the type is used.
17276 if Present (Full_View (Prev)) then
17277 Error_Msg_NE ("invalid redeclaration of }", Id, Prev);
17278 end if;
17280 Set_Full_View (Prev, Id);
17281 Append_Entity (Id, Current_Scope);
17282 Set_Is_Public (Id, Is_Public (Prev));
17283 Set_Is_Internal (Id);
17284 New_Id := Prev;
17286 -- If the incomplete view is tagged, a class_wide type has been
17287 -- created already. Use it for the private type as well, in order
17288 -- to prevent multiple incompatible class-wide types that may be
17289 -- created for self-referential anonymous access components.
17291 if Is_Tagged_Type (Prev)
17292 and then Present (Class_Wide_Type (Prev))
17293 then
17294 Set_Ekind (Id, Ekind (Prev)); -- will be reset later
17295 Set_Class_Wide_Type (Id, Class_Wide_Type (Prev));
17297 -- Type of the class-wide type is the current Id. Previously
17298 -- this was not done for private declarations because of order-
17299 -- of-elaboration issues in the back end, but gigi now handles
17300 -- this properly.
17302 Set_Etype (Class_Wide_Type (Id), Id);
17303 end if;
17305 -- Case of full declaration of private type
17307 else
17308 -- If the private type was a completion of an incomplete type then
17309 -- update Prev to reference the private type
17311 if Ada_Version >= Ada_2012
17312 and then Ekind (Prev) = E_Incomplete_Type
17313 and then Present (Full_View (Prev))
17314 and then Is_Private_Type (Full_View (Prev))
17315 then
17316 Prev := Full_View (Prev);
17317 Prev_Par := Parent (Prev);
17318 end if;
17320 if Nkind (N) = N_Full_Type_Declaration
17321 and then Nkind_In
17322 (Type_Definition (N), N_Record_Definition,
17323 N_Derived_Type_Definition)
17324 and then Interface_Present (Type_Definition (N))
17325 then
17326 Error_Msg_N
17327 ("completion of private type cannot be an interface", N);
17328 end if;
17330 if Nkind (Parent (Prev)) /= N_Private_Extension_Declaration then
17331 if Etype (Prev) /= Prev then
17333 -- Prev is a private subtype or a derived type, and needs
17334 -- no completion.
17336 Error_Msg_NE ("invalid redeclaration of }", Id, Prev);
17337 New_Id := Id;
17339 elsif Ekind (Prev) = E_Private_Type
17340 and then Nkind_In (N, N_Task_Type_Declaration,
17341 N_Protected_Type_Declaration)
17342 then
17343 Error_Msg_N
17344 ("completion of nonlimited type cannot be limited", N);
17346 elsif Ekind (Prev) = E_Record_Type_With_Private
17347 and then Nkind_In (N, N_Task_Type_Declaration,
17348 N_Protected_Type_Declaration)
17349 then
17350 if not Is_Limited_Record (Prev) then
17351 Error_Msg_N
17352 ("completion of nonlimited type cannot be limited", N);
17354 elsif No (Interface_List (N)) then
17355 Error_Msg_N
17356 ("completion of tagged private type must be tagged",
17358 end if;
17359 end if;
17361 -- Ada 2005 (AI-251): Private extension declaration of a task
17362 -- type or a protected type. This case arises when covering
17363 -- interface types.
17365 elsif Nkind_In (N, N_Task_Type_Declaration,
17366 N_Protected_Type_Declaration)
17367 then
17368 null;
17370 elsif Nkind (N) /= N_Full_Type_Declaration
17371 or else Nkind (Type_Definition (N)) /= N_Derived_Type_Definition
17372 then
17373 Error_Msg_N
17374 ("full view of private extension must be an extension", N);
17376 elsif not (Abstract_Present (Parent (Prev)))
17377 and then Abstract_Present (Type_Definition (N))
17378 then
17379 Error_Msg_N
17380 ("full view of non-abstract extension cannot be abstract", N);
17381 end if;
17383 if not In_Private_Part (Current_Scope) then
17384 Error_Msg_N
17385 ("declaration of full view must appear in private part", N);
17386 end if;
17388 if Ada_Version >= Ada_2012 then
17389 Check_Duplicate_Aspects;
17390 end if;
17392 Copy_And_Swap (Prev, Id);
17393 Set_Has_Private_Declaration (Prev);
17394 Set_Has_Private_Declaration (Id);
17396 -- AI12-0133: Indicate whether we have a partial view with
17397 -- unknown discriminants, in which case initialization of objects
17398 -- of the type do not receive an invariant check.
17400 Set_Partial_View_Has_Unknown_Discr
17401 (Prev, Has_Unknown_Discriminants (Id));
17403 -- Preserve aspect and iterator flags that may have been set on
17404 -- the partial view.
17406 Set_Has_Delayed_Aspects (Prev, Has_Delayed_Aspects (Id));
17407 Set_Has_Implicit_Dereference (Prev, Has_Implicit_Dereference (Id));
17409 -- If no error, propagate freeze_node from private to full view.
17410 -- It may have been generated for an early operational item.
17412 if Present (Freeze_Node (Id))
17413 and then Serious_Errors_Detected = 0
17414 and then No (Full_View (Id))
17415 then
17416 Set_Freeze_Node (Prev, Freeze_Node (Id));
17417 Set_Freeze_Node (Id, Empty);
17418 Set_First_Rep_Item (Prev, First_Rep_Item (Id));
17419 end if;
17421 Set_Full_View (Id, Prev);
17422 New_Id := Prev;
17423 end if;
17425 -- Verify that full declaration conforms to partial one
17427 if Is_Incomplete_Or_Private_Type (Prev)
17428 and then Present (Discriminant_Specifications (Prev_Par))
17429 then
17430 if Present (Discriminant_Specifications (N)) then
17431 if Ekind (Prev) = E_Incomplete_Type then
17432 Check_Discriminant_Conformance (N, Prev, Prev);
17433 else
17434 Check_Discriminant_Conformance (N, Prev, Id);
17435 end if;
17437 else
17438 Error_Msg_N
17439 ("missing discriminants in full type declaration", N);
17441 -- To avoid cascaded errors on subsequent use, share the
17442 -- discriminants of the partial view.
17444 Set_Discriminant_Specifications (N,
17445 Discriminant_Specifications (Prev_Par));
17446 end if;
17447 end if;
17449 -- A prior untagged partial view can have an associated class-wide
17450 -- type due to use of the class attribute, and in this case the full
17451 -- type must also be tagged. This Ada 95 usage is deprecated in favor
17452 -- of incomplete tagged declarations, but we check for it.
17454 if Is_Type (Prev)
17455 and then (Is_Tagged_Type (Prev)
17456 or else Present (Class_Wide_Type (Prev)))
17457 then
17458 -- Ada 2012 (AI05-0162): A private type may be the completion of
17459 -- an incomplete type.
17461 if Ada_Version >= Ada_2012
17462 and then Is_Incomplete_Type (Prev)
17463 and then Nkind_In (N, N_Private_Type_Declaration,
17464 N_Private_Extension_Declaration)
17465 then
17466 -- No need to check private extensions since they are tagged
17468 if Nkind (N) = N_Private_Type_Declaration
17469 and then not Tagged_Present (N)
17470 then
17471 Tag_Mismatch;
17472 end if;
17474 -- The full declaration is either a tagged type (including
17475 -- a synchronized type that implements interfaces) or a
17476 -- type extension, otherwise this is an error.
17478 elsif Nkind_In (N, N_Task_Type_Declaration,
17479 N_Protected_Type_Declaration)
17480 then
17481 if No (Interface_List (N)) and then not Error_Posted (N) then
17482 Tag_Mismatch;
17483 end if;
17485 elsif Nkind (Type_Definition (N)) = N_Record_Definition then
17487 -- Indicate that the previous declaration (tagged incomplete
17488 -- or private declaration) requires the same on the full one.
17490 if not Tagged_Present (Type_Definition (N)) then
17491 Tag_Mismatch;
17492 Set_Is_Tagged_Type (Id);
17493 end if;
17495 elsif Nkind (Type_Definition (N)) = N_Derived_Type_Definition then
17496 if No (Record_Extension_Part (Type_Definition (N))) then
17497 Error_Msg_NE
17498 ("full declaration of } must be a record extension",
17499 Prev, Id);
17501 -- Set some attributes to produce a usable full view
17503 Set_Is_Tagged_Type (Id);
17504 end if;
17506 else
17507 Tag_Mismatch;
17508 end if;
17509 end if;
17511 if Present (Prev)
17512 and then Nkind (Parent (Prev)) = N_Incomplete_Type_Declaration
17513 and then Present (Premature_Use (Parent (Prev)))
17514 then
17515 Error_Msg_Sloc := Sloc (N);
17516 Error_Msg_N
17517 ("\full declaration #", Premature_Use (Parent (Prev)));
17518 end if;
17520 return New_Id;
17521 end if;
17522 end Find_Type_Name;
17524 -------------------------
17525 -- Find_Type_Of_Object --
17526 -------------------------
17528 function Find_Type_Of_Object
17529 (Obj_Def : Node_Id;
17530 Related_Nod : Node_Id) return Entity_Id
17532 Def_Kind : constant Node_Kind := Nkind (Obj_Def);
17533 P : Node_Id := Parent (Obj_Def);
17534 T : Entity_Id;
17535 Nam : Name_Id;
17537 begin
17538 -- If the parent is a component_definition node we climb to the
17539 -- component_declaration node
17541 if Nkind (P) = N_Component_Definition then
17542 P := Parent (P);
17543 end if;
17545 -- Case of an anonymous array subtype
17547 if Nkind_In (Def_Kind, N_Constrained_Array_Definition,
17548 N_Unconstrained_Array_Definition)
17549 then
17550 T := Empty;
17551 Array_Type_Declaration (T, Obj_Def);
17553 -- Create an explicit subtype whenever possible
17555 elsif Nkind (P) /= N_Component_Declaration
17556 and then Def_Kind = N_Subtype_Indication
17557 then
17558 -- Base name of subtype on object name, which will be unique in
17559 -- the current scope.
17561 -- If this is a duplicate declaration, return base type, to avoid
17562 -- generating duplicate anonymous types.
17564 if Error_Posted (P) then
17565 Analyze (Subtype_Mark (Obj_Def));
17566 return Entity (Subtype_Mark (Obj_Def));
17567 end if;
17569 Nam :=
17570 New_External_Name
17571 (Chars (Defining_Identifier (Related_Nod)), 'S', 0, 'T');
17573 T := Make_Defining_Identifier (Sloc (P), Nam);
17575 Insert_Action (Obj_Def,
17576 Make_Subtype_Declaration (Sloc (P),
17577 Defining_Identifier => T,
17578 Subtype_Indication => Relocate_Node (Obj_Def)));
17580 -- This subtype may need freezing, and this will not be done
17581 -- automatically if the object declaration is not in declarative
17582 -- part. Since this is an object declaration, the type cannot always
17583 -- be frozen here. Deferred constants do not freeze their type
17584 -- (which often enough will be private).
17586 if Nkind (P) = N_Object_Declaration
17587 and then Constant_Present (P)
17588 and then No (Expression (P))
17589 then
17590 null;
17592 -- Here we freeze the base type of object type to catch premature use
17593 -- of discriminated private type without a full view.
17595 else
17596 Insert_Actions (Obj_Def, Freeze_Entity (Base_Type (T), P));
17597 end if;
17599 -- Ada 2005 AI-406: the object definition in an object declaration
17600 -- can be an access definition.
17602 elsif Def_Kind = N_Access_Definition then
17603 T := Access_Definition (Related_Nod, Obj_Def);
17605 Set_Is_Local_Anonymous_Access
17607 V => (Ada_Version < Ada_2012)
17608 or else (Nkind (P) /= N_Object_Declaration)
17609 or else Is_Library_Level_Entity (Defining_Identifier (P)));
17611 -- Otherwise, the object definition is just a subtype_mark
17613 else
17614 T := Process_Subtype (Obj_Def, Related_Nod);
17616 -- If expansion is disabled an object definition that is an aggregate
17617 -- will not get expanded and may lead to scoping problems in the back
17618 -- end, if the object is referenced in an inner scope. In that case
17619 -- create an itype reference for the object definition now. This
17620 -- may be redundant in some cases, but harmless.
17622 if Is_Itype (T)
17623 and then Nkind (Related_Nod) = N_Object_Declaration
17624 and then ASIS_Mode
17625 then
17626 Build_Itype_Reference (T, Related_Nod);
17627 end if;
17628 end if;
17630 return T;
17631 end Find_Type_Of_Object;
17633 --------------------------------
17634 -- Find_Type_Of_Subtype_Indic --
17635 --------------------------------
17637 function Find_Type_Of_Subtype_Indic (S : Node_Id) return Entity_Id is
17638 Typ : Entity_Id;
17640 begin
17641 -- Case of subtype mark with a constraint
17643 if Nkind (S) = N_Subtype_Indication then
17644 Find_Type (Subtype_Mark (S));
17645 Typ := Entity (Subtype_Mark (S));
17647 if not
17648 Is_Valid_Constraint_Kind (Ekind (Typ), Nkind (Constraint (S)))
17649 then
17650 Error_Msg_N
17651 ("incorrect constraint for this kind of type", Constraint (S));
17652 Rewrite (S, New_Copy_Tree (Subtype_Mark (S)));
17653 end if;
17655 -- Otherwise we have a subtype mark without a constraint
17657 elsif Error_Posted (S) then
17658 Rewrite (S, New_Occurrence_Of (Any_Id, Sloc (S)));
17659 return Any_Type;
17661 else
17662 Find_Type (S);
17663 Typ := Entity (S);
17664 end if;
17666 -- Check No_Wide_Characters restriction
17668 Check_Wide_Character_Restriction (Typ, S);
17670 return Typ;
17671 end Find_Type_Of_Subtype_Indic;
17673 -------------------------------------
17674 -- Floating_Point_Type_Declaration --
17675 -------------------------------------
17677 procedure Floating_Point_Type_Declaration (T : Entity_Id; Def : Node_Id) is
17678 Digs : constant Node_Id := Digits_Expression (Def);
17679 Max_Digs_Val : constant Uint := Digits_Value (Standard_Long_Long_Float);
17680 Digs_Val : Uint;
17681 Base_Typ : Entity_Id;
17682 Implicit_Base : Entity_Id;
17683 Bound : Node_Id;
17685 function Can_Derive_From (E : Entity_Id) return Boolean;
17686 -- Find if given digits value, and possibly a specified range, allows
17687 -- derivation from specified type
17689 function Find_Base_Type return Entity_Id;
17690 -- Find a predefined base type that Def can derive from, or generate
17691 -- an error and substitute Long_Long_Float if none exists.
17693 ---------------------
17694 -- Can_Derive_From --
17695 ---------------------
17697 function Can_Derive_From (E : Entity_Id) return Boolean is
17698 Spec : constant Entity_Id := Real_Range_Specification (Def);
17700 begin
17701 -- Check specified "digits" constraint
17703 if Digs_Val > Digits_Value (E) then
17704 return False;
17705 end if;
17707 -- Check for matching range, if specified
17709 if Present (Spec) then
17710 if Expr_Value_R (Type_Low_Bound (E)) >
17711 Expr_Value_R (Low_Bound (Spec))
17712 then
17713 return False;
17714 end if;
17716 if Expr_Value_R (Type_High_Bound (E)) <
17717 Expr_Value_R (High_Bound (Spec))
17718 then
17719 return False;
17720 end if;
17721 end if;
17723 return True;
17724 end Can_Derive_From;
17726 --------------------
17727 -- Find_Base_Type --
17728 --------------------
17730 function Find_Base_Type return Entity_Id is
17731 Choice : Elmt_Id := First_Elmt (Predefined_Float_Types);
17733 begin
17734 -- Iterate over the predefined types in order, returning the first
17735 -- one that Def can derive from.
17737 while Present (Choice) loop
17738 if Can_Derive_From (Node (Choice)) then
17739 return Node (Choice);
17740 end if;
17742 Next_Elmt (Choice);
17743 end loop;
17745 -- If we can't derive from any existing type, use Long_Long_Float
17746 -- and give appropriate message explaining the problem.
17748 if Digs_Val > Max_Digs_Val then
17749 -- It might be the case that there is a type with the requested
17750 -- range, just not the combination of digits and range.
17752 Error_Msg_N
17753 ("no predefined type has requested range and precision",
17754 Real_Range_Specification (Def));
17756 else
17757 Error_Msg_N
17758 ("range too large for any predefined type",
17759 Real_Range_Specification (Def));
17760 end if;
17762 return Standard_Long_Long_Float;
17763 end Find_Base_Type;
17765 -- Start of processing for Floating_Point_Type_Declaration
17767 begin
17768 Check_Restriction (No_Floating_Point, Def);
17770 -- Create an implicit base type
17772 Implicit_Base :=
17773 Create_Itype (E_Floating_Point_Type, Parent (Def), T, 'B');
17775 -- Analyze and verify digits value
17777 Analyze_And_Resolve (Digs, Any_Integer);
17778 Check_Digits_Expression (Digs);
17779 Digs_Val := Expr_Value (Digs);
17781 -- Process possible range spec and find correct type to derive from
17783 Process_Real_Range_Specification (Def);
17785 -- Check that requested number of digits is not too high.
17787 if Digs_Val > Max_Digs_Val then
17789 -- The check for Max_Base_Digits may be somewhat expensive, as it
17790 -- requires reading System, so only do it when necessary.
17792 declare
17793 Max_Base_Digits : constant Uint :=
17794 Expr_Value
17795 (Expression
17796 (Parent (RTE (RE_Max_Base_Digits))));
17798 begin
17799 if Digs_Val > Max_Base_Digits then
17800 Error_Msg_Uint_1 := Max_Base_Digits;
17801 Error_Msg_N ("digits value out of range, maximum is ^", Digs);
17803 elsif No (Real_Range_Specification (Def)) then
17804 Error_Msg_Uint_1 := Max_Digs_Val;
17805 Error_Msg_N ("types with more than ^ digits need range spec "
17806 & "(RM 3.5.7(6))", Digs);
17807 end if;
17808 end;
17809 end if;
17811 -- Find a suitable type to derive from or complain and use a substitute
17813 Base_Typ := Find_Base_Type;
17815 -- If there are bounds given in the declaration use them as the bounds
17816 -- of the type, otherwise use the bounds of the predefined base type
17817 -- that was chosen based on the Digits value.
17819 if Present (Real_Range_Specification (Def)) then
17820 Set_Scalar_Range (T, Real_Range_Specification (Def));
17821 Set_Is_Constrained (T);
17823 -- The bounds of this range must be converted to machine numbers
17824 -- in accordance with RM 4.9(38).
17826 Bound := Type_Low_Bound (T);
17828 if Nkind (Bound) = N_Real_Literal then
17829 Set_Realval
17830 (Bound, Machine (Base_Typ, Realval (Bound), Round, Bound));
17831 Set_Is_Machine_Number (Bound);
17832 end if;
17834 Bound := Type_High_Bound (T);
17836 if Nkind (Bound) = N_Real_Literal then
17837 Set_Realval
17838 (Bound, Machine (Base_Typ, Realval (Bound), Round, Bound));
17839 Set_Is_Machine_Number (Bound);
17840 end if;
17842 else
17843 Set_Scalar_Range (T, Scalar_Range (Base_Typ));
17844 end if;
17846 -- Complete definition of implicit base and declared first subtype. The
17847 -- inheritance of the rep item chain ensures that SPARK-related pragmas
17848 -- are not clobbered when the floating point type acts as a full view of
17849 -- a private type.
17851 Set_Etype (Implicit_Base, Base_Typ);
17852 Set_Scalar_Range (Implicit_Base, Scalar_Range (Base_Typ));
17853 Set_Size_Info (Implicit_Base, Base_Typ);
17854 Set_RM_Size (Implicit_Base, RM_Size (Base_Typ));
17855 Set_First_Rep_Item (Implicit_Base, First_Rep_Item (Base_Typ));
17856 Set_Digits_Value (Implicit_Base, Digits_Value (Base_Typ));
17857 Set_Float_Rep (Implicit_Base, Float_Rep (Base_Typ));
17859 Set_Ekind (T, E_Floating_Point_Subtype);
17860 Set_Etype (T, Implicit_Base);
17861 Set_Size_Info (T, Implicit_Base);
17862 Set_RM_Size (T, RM_Size (Implicit_Base));
17863 Inherit_Rep_Item_Chain (T, Implicit_Base);
17864 Set_Digits_Value (T, Digs_Val);
17865 end Floating_Point_Type_Declaration;
17867 ----------------------------
17868 -- Get_Discriminant_Value --
17869 ----------------------------
17871 -- This is the situation:
17873 -- There is a non-derived type
17875 -- type T0 (Dx, Dy, Dz...)
17877 -- There are zero or more levels of derivation, with each derivation
17878 -- either purely inheriting the discriminants, or defining its own.
17880 -- type Ti is new Ti-1
17881 -- or
17882 -- type Ti (Dw) is new Ti-1(Dw, 1, X+Y)
17883 -- or
17884 -- subtype Ti is ...
17886 -- The subtype issue is avoided by the use of Original_Record_Component,
17887 -- and the fact that derived subtypes also derive the constraints.
17889 -- This chain leads back from
17891 -- Typ_For_Constraint
17893 -- Typ_For_Constraint has discriminants, and the value for each
17894 -- discriminant is given by its corresponding Elmt of Constraints.
17896 -- Discriminant is some discriminant in this hierarchy
17898 -- We need to return its value
17900 -- We do this by recursively searching each level, and looking for
17901 -- Discriminant. Once we get to the bottom, we start backing up
17902 -- returning the value for it which may in turn be a discriminant
17903 -- further up, so on the backup we continue the substitution.
17905 function Get_Discriminant_Value
17906 (Discriminant : Entity_Id;
17907 Typ_For_Constraint : Entity_Id;
17908 Constraint : Elist_Id) return Node_Id
17910 function Root_Corresponding_Discriminant
17911 (Discr : Entity_Id) return Entity_Id;
17912 -- Given a discriminant, traverse the chain of inherited discriminants
17913 -- and return the topmost discriminant.
17915 function Search_Derivation_Levels
17916 (Ti : Entity_Id;
17917 Discrim_Values : Elist_Id;
17918 Stored_Discrim_Values : Boolean) return Node_Or_Entity_Id;
17919 -- This is the routine that performs the recursive search of levels
17920 -- as described above.
17922 -------------------------------------
17923 -- Root_Corresponding_Discriminant --
17924 -------------------------------------
17926 function Root_Corresponding_Discriminant
17927 (Discr : Entity_Id) return Entity_Id
17929 D : Entity_Id;
17931 begin
17932 D := Discr;
17933 while Present (Corresponding_Discriminant (D)) loop
17934 D := Corresponding_Discriminant (D);
17935 end loop;
17937 return D;
17938 end Root_Corresponding_Discriminant;
17940 ------------------------------
17941 -- Search_Derivation_Levels --
17942 ------------------------------
17944 function Search_Derivation_Levels
17945 (Ti : Entity_Id;
17946 Discrim_Values : Elist_Id;
17947 Stored_Discrim_Values : Boolean) return Node_Or_Entity_Id
17949 Assoc : Elmt_Id;
17950 Disc : Entity_Id;
17951 Result : Node_Or_Entity_Id;
17952 Result_Entity : Node_Id;
17954 begin
17955 -- If inappropriate type, return Error, this happens only in
17956 -- cascaded error situations, and we want to avoid a blow up.
17958 if not Is_Composite_Type (Ti) or else Is_Array_Type (Ti) then
17959 return Error;
17960 end if;
17962 -- Look deeper if possible. Use Stored_Constraints only for
17963 -- untagged types. For tagged types use the given constraint.
17964 -- This asymmetry needs explanation???
17966 if not Stored_Discrim_Values
17967 and then Present (Stored_Constraint (Ti))
17968 and then not Is_Tagged_Type (Ti)
17969 then
17970 Result :=
17971 Search_Derivation_Levels (Ti, Stored_Constraint (Ti), True);
17972 else
17973 declare
17974 Td : constant Entity_Id := Etype (Ti);
17976 begin
17977 if Td = Ti then
17978 Result := Discriminant;
17980 else
17981 if Present (Stored_Constraint (Ti)) then
17982 Result :=
17983 Search_Derivation_Levels
17984 (Td, Stored_Constraint (Ti), True);
17985 else
17986 Result :=
17987 Search_Derivation_Levels
17988 (Td, Discrim_Values, Stored_Discrim_Values);
17989 end if;
17990 end if;
17991 end;
17992 end if;
17994 -- Extra underlying places to search, if not found above. For
17995 -- concurrent types, the relevant discriminant appears in the
17996 -- corresponding record. For a type derived from a private type
17997 -- without discriminant, the full view inherits the discriminants
17998 -- of the full view of the parent.
18000 if Result = Discriminant then
18001 if Is_Concurrent_Type (Ti)
18002 and then Present (Corresponding_Record_Type (Ti))
18003 then
18004 Result :=
18005 Search_Derivation_Levels (
18006 Corresponding_Record_Type (Ti),
18007 Discrim_Values,
18008 Stored_Discrim_Values);
18010 elsif Is_Private_Type (Ti)
18011 and then not Has_Discriminants (Ti)
18012 and then Present (Full_View (Ti))
18013 and then Etype (Full_View (Ti)) /= Ti
18014 then
18015 Result :=
18016 Search_Derivation_Levels (
18017 Full_View (Ti),
18018 Discrim_Values,
18019 Stored_Discrim_Values);
18020 end if;
18021 end if;
18023 -- If Result is not a (reference to a) discriminant, return it,
18024 -- otherwise set Result_Entity to the discriminant.
18026 if Nkind (Result) = N_Defining_Identifier then
18027 pragma Assert (Result = Discriminant);
18028 Result_Entity := Result;
18030 else
18031 if not Denotes_Discriminant (Result) then
18032 return Result;
18033 end if;
18035 Result_Entity := Entity (Result);
18036 end if;
18038 -- See if this level of derivation actually has discriminants because
18039 -- tagged derivations can add them, hence the lower levels need not
18040 -- have any.
18042 if not Has_Discriminants (Ti) then
18043 return Result;
18044 end if;
18046 -- Scan Ti's discriminants for Result_Entity, and return its
18047 -- corresponding value, if any.
18049 Result_Entity := Original_Record_Component (Result_Entity);
18051 Assoc := First_Elmt (Discrim_Values);
18053 if Stored_Discrim_Values then
18054 Disc := First_Stored_Discriminant (Ti);
18055 else
18056 Disc := First_Discriminant (Ti);
18057 end if;
18059 while Present (Disc) loop
18061 -- If no further associations return the discriminant, value will
18062 -- be found on the second pass.
18064 if No (Assoc) then
18065 return Result;
18066 end if;
18068 if Original_Record_Component (Disc) = Result_Entity then
18069 return Node (Assoc);
18070 end if;
18072 Next_Elmt (Assoc);
18074 if Stored_Discrim_Values then
18075 Next_Stored_Discriminant (Disc);
18076 else
18077 Next_Discriminant (Disc);
18078 end if;
18079 end loop;
18081 -- Could not find it
18083 return Result;
18084 end Search_Derivation_Levels;
18086 -- Local Variables
18088 Result : Node_Or_Entity_Id;
18090 -- Start of processing for Get_Discriminant_Value
18092 begin
18093 -- ??? This routine is a gigantic mess and will be deleted. For the
18094 -- time being just test for the trivial case before calling recurse.
18096 -- We are now celebrating the 20th anniversary of this comment!
18098 if Base_Type (Scope (Discriminant)) = Base_Type (Typ_For_Constraint) then
18099 declare
18100 D : Entity_Id;
18101 E : Elmt_Id;
18103 begin
18104 D := First_Discriminant (Typ_For_Constraint);
18105 E := First_Elmt (Constraint);
18106 while Present (D) loop
18107 if Chars (D) = Chars (Discriminant) then
18108 return Node (E);
18109 end if;
18111 Next_Discriminant (D);
18112 Next_Elmt (E);
18113 end loop;
18114 end;
18115 end if;
18117 Result := Search_Derivation_Levels
18118 (Typ_For_Constraint, Constraint, False);
18120 -- ??? hack to disappear when this routine is gone
18122 if Nkind (Result) = N_Defining_Identifier then
18123 declare
18124 D : Entity_Id;
18125 E : Elmt_Id;
18127 begin
18128 D := First_Discriminant (Typ_For_Constraint);
18129 E := First_Elmt (Constraint);
18130 while Present (D) loop
18131 if Root_Corresponding_Discriminant (D) = Discriminant then
18132 return Node (E);
18133 end if;
18135 Next_Discriminant (D);
18136 Next_Elmt (E);
18137 end loop;
18138 end;
18139 end if;
18141 pragma Assert (Nkind (Result) /= N_Defining_Identifier);
18142 return Result;
18143 end Get_Discriminant_Value;
18145 --------------------------
18146 -- Has_Range_Constraint --
18147 --------------------------
18149 function Has_Range_Constraint (N : Node_Id) return Boolean is
18150 C : constant Node_Id := Constraint (N);
18152 begin
18153 if Nkind (C) = N_Range_Constraint then
18154 return True;
18156 elsif Nkind (C) = N_Digits_Constraint then
18157 return
18158 Is_Decimal_Fixed_Point_Type (Entity (Subtype_Mark (N)))
18159 or else Present (Range_Constraint (C));
18161 elsif Nkind (C) = N_Delta_Constraint then
18162 return Present (Range_Constraint (C));
18164 else
18165 return False;
18166 end if;
18167 end Has_Range_Constraint;
18169 ------------------------
18170 -- Inherit_Components --
18171 ------------------------
18173 function Inherit_Components
18174 (N : Node_Id;
18175 Parent_Base : Entity_Id;
18176 Derived_Base : Entity_Id;
18177 Is_Tagged : Boolean;
18178 Inherit_Discr : Boolean;
18179 Discs : Elist_Id) return Elist_Id
18181 Assoc_List : constant Elist_Id := New_Elmt_List;
18183 procedure Inherit_Component
18184 (Old_C : Entity_Id;
18185 Plain_Discrim : Boolean := False;
18186 Stored_Discrim : Boolean := False);
18187 -- Inherits component Old_C from Parent_Base to the Derived_Base. If
18188 -- Plain_Discrim is True, Old_C is a discriminant. If Stored_Discrim is
18189 -- True, Old_C is a stored discriminant. If they are both false then
18190 -- Old_C is a regular component.
18192 -----------------------
18193 -- Inherit_Component --
18194 -----------------------
18196 procedure Inherit_Component
18197 (Old_C : Entity_Id;
18198 Plain_Discrim : Boolean := False;
18199 Stored_Discrim : Boolean := False)
18201 procedure Set_Anonymous_Type (Id : Entity_Id);
18202 -- Id denotes the entity of an access discriminant or anonymous
18203 -- access component. Set the type of Id to either the same type of
18204 -- Old_C or create a new one depending on whether the parent and
18205 -- the child types are in the same scope.
18207 ------------------------
18208 -- Set_Anonymous_Type --
18209 ------------------------
18211 procedure Set_Anonymous_Type (Id : Entity_Id) is
18212 Old_Typ : constant Entity_Id := Etype (Old_C);
18214 begin
18215 if Scope (Parent_Base) = Scope (Derived_Base) then
18216 Set_Etype (Id, Old_Typ);
18218 -- The parent and the derived type are in two different scopes.
18219 -- Reuse the type of the original discriminant / component by
18220 -- copying it in order to preserve all attributes.
18222 else
18223 declare
18224 Typ : constant Entity_Id := New_Copy (Old_Typ);
18226 begin
18227 Set_Etype (Id, Typ);
18229 -- Since we do not generate component declarations for
18230 -- inherited components, associate the itype with the
18231 -- derived type.
18233 Set_Associated_Node_For_Itype (Typ, Parent (Derived_Base));
18234 Set_Scope (Typ, Derived_Base);
18235 end;
18236 end if;
18237 end Set_Anonymous_Type;
18239 -- Local variables and constants
18241 New_C : constant Entity_Id := New_Copy (Old_C);
18243 Corr_Discrim : Entity_Id;
18244 Discrim : Entity_Id;
18246 -- Start of processing for Inherit_Component
18248 begin
18249 pragma Assert (not Is_Tagged or not Stored_Discrim);
18251 Set_Parent (New_C, Parent (Old_C));
18253 -- Regular discriminants and components must be inserted in the scope
18254 -- of the Derived_Base. Do it here.
18256 if not Stored_Discrim then
18257 Enter_Name (New_C);
18258 end if;
18260 -- For tagged types the Original_Record_Component must point to
18261 -- whatever this field was pointing to in the parent type. This has
18262 -- already been achieved by the call to New_Copy above.
18264 if not Is_Tagged then
18265 Set_Original_Record_Component (New_C, New_C);
18266 Set_Corresponding_Record_Component (New_C, Old_C);
18267 end if;
18269 -- Set the proper type of an access discriminant
18271 if Ekind (New_C) = E_Discriminant
18272 and then Ekind (Etype (New_C)) = E_Anonymous_Access_Type
18273 then
18274 Set_Anonymous_Type (New_C);
18275 end if;
18277 -- If we have inherited a component then see if its Etype contains
18278 -- references to Parent_Base discriminants. In this case, replace
18279 -- these references with the constraints given in Discs. We do not
18280 -- do this for the partial view of private types because this is
18281 -- not needed (only the components of the full view will be used
18282 -- for code generation) and cause problem. We also avoid this
18283 -- transformation in some error situations.
18285 if Ekind (New_C) = E_Component then
18287 -- Set the proper type of an anonymous access component
18289 if Ekind (Etype (New_C)) = E_Anonymous_Access_Type then
18290 Set_Anonymous_Type (New_C);
18292 elsif (Is_Private_Type (Derived_Base)
18293 and then not Is_Generic_Type (Derived_Base))
18294 or else (Is_Empty_Elmt_List (Discs)
18295 and then not Expander_Active)
18296 then
18297 Set_Etype (New_C, Etype (Old_C));
18299 else
18300 -- The current component introduces a circularity of the
18301 -- following kind:
18303 -- limited with Pack_2;
18304 -- package Pack_1 is
18305 -- type T_1 is tagged record
18306 -- Comp : access Pack_2.T_2;
18307 -- ...
18308 -- end record;
18309 -- end Pack_1;
18311 -- with Pack_1;
18312 -- package Pack_2 is
18313 -- type T_2 is new Pack_1.T_1 with ...;
18314 -- end Pack_2;
18316 Set_Etype
18317 (New_C,
18318 Constrain_Component_Type
18319 (Old_C, Derived_Base, N, Parent_Base, Discs));
18320 end if;
18321 end if;
18323 -- In derived tagged types it is illegal to reference a non
18324 -- discriminant component in the parent type. To catch this, mark
18325 -- these components with an Ekind of E_Void. This will be reset in
18326 -- Record_Type_Definition after processing the record extension of
18327 -- the derived type.
18329 -- If the declaration is a private extension, there is no further
18330 -- record extension to process, and the components retain their
18331 -- current kind, because they are visible at this point.
18333 if Is_Tagged and then Ekind (New_C) = E_Component
18334 and then Nkind (N) /= N_Private_Extension_Declaration
18335 then
18336 Set_Ekind (New_C, E_Void);
18337 end if;
18339 if Plain_Discrim then
18340 Set_Corresponding_Discriminant (New_C, Old_C);
18341 Build_Discriminal (New_C);
18343 -- If we are explicitly inheriting a stored discriminant it will be
18344 -- completely hidden.
18346 elsif Stored_Discrim then
18347 Set_Corresponding_Discriminant (New_C, Empty);
18348 Set_Discriminal (New_C, Empty);
18349 Set_Is_Completely_Hidden (New_C);
18351 -- Set the Original_Record_Component of each discriminant in the
18352 -- derived base to point to the corresponding stored that we just
18353 -- created.
18355 Discrim := First_Discriminant (Derived_Base);
18356 while Present (Discrim) loop
18357 Corr_Discrim := Corresponding_Discriminant (Discrim);
18359 -- Corr_Discrim could be missing in an error situation
18361 if Present (Corr_Discrim)
18362 and then Original_Record_Component (Corr_Discrim) = Old_C
18363 then
18364 Set_Original_Record_Component (Discrim, New_C);
18365 Set_Corresponding_Record_Component (Discrim, Empty);
18366 end if;
18368 Next_Discriminant (Discrim);
18369 end loop;
18371 Append_Entity (New_C, Derived_Base);
18372 end if;
18374 if not Is_Tagged then
18375 Append_Elmt (Old_C, Assoc_List);
18376 Append_Elmt (New_C, Assoc_List);
18377 end if;
18378 end Inherit_Component;
18380 -- Variables local to Inherit_Component
18382 Loc : constant Source_Ptr := Sloc (N);
18384 Parent_Discrim : Entity_Id;
18385 Stored_Discrim : Entity_Id;
18386 D : Entity_Id;
18387 Component : Entity_Id;
18389 -- Start of processing for Inherit_Components
18391 begin
18392 if not Is_Tagged then
18393 Append_Elmt (Parent_Base, Assoc_List);
18394 Append_Elmt (Derived_Base, Assoc_List);
18395 end if;
18397 -- Inherit parent discriminants if needed
18399 if Inherit_Discr then
18400 Parent_Discrim := First_Discriminant (Parent_Base);
18401 while Present (Parent_Discrim) loop
18402 Inherit_Component (Parent_Discrim, Plain_Discrim => True);
18403 Next_Discriminant (Parent_Discrim);
18404 end loop;
18405 end if;
18407 -- Create explicit stored discrims for untagged types when necessary
18409 if not Has_Unknown_Discriminants (Derived_Base)
18410 and then Has_Discriminants (Parent_Base)
18411 and then not Is_Tagged
18412 and then
18413 (not Inherit_Discr
18414 or else First_Discriminant (Parent_Base) /=
18415 First_Stored_Discriminant (Parent_Base))
18416 then
18417 Stored_Discrim := First_Stored_Discriminant (Parent_Base);
18418 while Present (Stored_Discrim) loop
18419 Inherit_Component (Stored_Discrim, Stored_Discrim => True);
18420 Next_Stored_Discriminant (Stored_Discrim);
18421 end loop;
18422 end if;
18424 -- See if we can apply the second transformation for derived types, as
18425 -- explained in point 6. in the comments above Build_Derived_Record_Type
18426 -- This is achieved by appending Derived_Base discriminants into Discs,
18427 -- which has the side effect of returning a non empty Discs list to the
18428 -- caller of Inherit_Components, which is what we want. This must be
18429 -- done for private derived types if there are explicit stored
18430 -- discriminants, to ensure that we can retrieve the values of the
18431 -- constraints provided in the ancestors.
18433 if Inherit_Discr
18434 and then Is_Empty_Elmt_List (Discs)
18435 and then Present (First_Discriminant (Derived_Base))
18436 and then
18437 (not Is_Private_Type (Derived_Base)
18438 or else Is_Completely_Hidden
18439 (First_Stored_Discriminant (Derived_Base))
18440 or else Is_Generic_Type (Derived_Base))
18441 then
18442 D := First_Discriminant (Derived_Base);
18443 while Present (D) loop
18444 Append_Elmt (New_Occurrence_Of (D, Loc), Discs);
18445 Next_Discriminant (D);
18446 end loop;
18447 end if;
18449 -- Finally, inherit non-discriminant components unless they are not
18450 -- visible because defined or inherited from the full view of the
18451 -- parent. Don't inherit the _parent field of the parent type.
18453 Component := First_Entity (Parent_Base);
18454 while Present (Component) loop
18456 -- Ada 2005 (AI-251): Do not inherit components associated with
18457 -- secondary tags of the parent.
18459 if Ekind (Component) = E_Component
18460 and then Present (Related_Type (Component))
18461 then
18462 null;
18464 elsif Ekind (Component) /= E_Component
18465 or else Chars (Component) = Name_uParent
18466 then
18467 null;
18469 -- If the derived type is within the parent type's declarative
18470 -- region, then the components can still be inherited even though
18471 -- they aren't visible at this point. This can occur for cases
18472 -- such as within public child units where the components must
18473 -- become visible upon entering the child unit's private part.
18475 elsif not Is_Visible_Component (Component)
18476 and then not In_Open_Scopes (Scope (Parent_Base))
18477 then
18478 null;
18480 elsif Ekind_In (Derived_Base, E_Private_Type,
18481 E_Limited_Private_Type)
18482 then
18483 null;
18485 else
18486 Inherit_Component (Component);
18487 end if;
18489 Next_Entity (Component);
18490 end loop;
18492 -- For tagged derived types, inherited discriminants cannot be used in
18493 -- component declarations of the record extension part. To achieve this
18494 -- we mark the inherited discriminants as not visible.
18496 if Is_Tagged and then Inherit_Discr then
18497 D := First_Discriminant (Derived_Base);
18498 while Present (D) loop
18499 Set_Is_Immediately_Visible (D, False);
18500 Next_Discriminant (D);
18501 end loop;
18502 end if;
18504 return Assoc_List;
18505 end Inherit_Components;
18507 -----------------------------
18508 -- Inherit_Predicate_Flags --
18509 -----------------------------
18511 procedure Inherit_Predicate_Flags (Subt, Par : Entity_Id) is
18512 begin
18513 Set_Has_Predicates (Subt, Has_Predicates (Par));
18514 Set_Has_Static_Predicate_Aspect
18515 (Subt, Has_Static_Predicate_Aspect (Par));
18516 Set_Has_Dynamic_Predicate_Aspect
18517 (Subt, Has_Dynamic_Predicate_Aspect (Par));
18519 -- A named subtype does not inherit the predicate function of its
18520 -- parent but an itype declared for a loop index needs the discrete
18521 -- predicate information of its parent to execute the loop properly.
18523 if Is_Itype (Subt) and then Present (Predicate_Function (Par)) then
18524 Set_Subprograms_For_Type (Subt, Subprograms_For_Type (Par));
18526 if Has_Static_Predicate (Par) then
18527 Set_Static_Discrete_Predicate
18528 (Subt, Static_Discrete_Predicate (Par));
18529 end if;
18530 end if;
18531 end Inherit_Predicate_Flags;
18533 ----------------------
18534 -- Is_EVF_Procedure --
18535 ----------------------
18537 function Is_EVF_Procedure (Subp : Entity_Id) return Boolean is
18538 Formal : Entity_Id;
18540 begin
18541 -- Examine the formals of an Extensions_Visible False procedure looking
18542 -- for a controlling OUT parameter.
18544 if Ekind (Subp) = E_Procedure
18545 and then Extensions_Visible_Status (Subp) = Extensions_Visible_False
18546 then
18547 Formal := First_Formal (Subp);
18548 while Present (Formal) loop
18549 if Ekind (Formal) = E_Out_Parameter
18550 and then Is_Controlling_Formal (Formal)
18551 then
18552 return True;
18553 end if;
18555 Next_Formal (Formal);
18556 end loop;
18557 end if;
18559 return False;
18560 end Is_EVF_Procedure;
18562 -----------------------
18563 -- Is_Null_Extension --
18564 -----------------------
18566 function Is_Null_Extension (T : Entity_Id) return Boolean is
18567 Type_Decl : constant Node_Id := Parent (Base_Type (T));
18568 Comp_List : Node_Id;
18569 Comp : Node_Id;
18571 begin
18572 if Nkind (Type_Decl) /= N_Full_Type_Declaration
18573 or else not Is_Tagged_Type (T)
18574 or else Nkind (Type_Definition (Type_Decl)) /=
18575 N_Derived_Type_Definition
18576 or else No (Record_Extension_Part (Type_Definition (Type_Decl)))
18577 then
18578 return False;
18579 end if;
18581 Comp_List :=
18582 Component_List (Record_Extension_Part (Type_Definition (Type_Decl)));
18584 if Present (Discriminant_Specifications (Type_Decl)) then
18585 return False;
18587 elsif Present (Comp_List)
18588 and then Is_Non_Empty_List (Component_Items (Comp_List))
18589 then
18590 Comp := First (Component_Items (Comp_List));
18592 -- Only user-defined components are relevant. The component list
18593 -- may also contain a parent component and internal components
18594 -- corresponding to secondary tags, but these do not determine
18595 -- whether this is a null extension.
18597 while Present (Comp) loop
18598 if Comes_From_Source (Comp) then
18599 return False;
18600 end if;
18602 Next (Comp);
18603 end loop;
18605 return True;
18607 else
18608 return True;
18609 end if;
18610 end Is_Null_Extension;
18612 ------------------------------
18613 -- Is_Valid_Constraint_Kind --
18614 ------------------------------
18616 function Is_Valid_Constraint_Kind
18617 (T_Kind : Type_Kind;
18618 Constraint_Kind : Node_Kind) return Boolean
18620 begin
18621 case T_Kind is
18622 when Enumeration_Kind
18623 | Integer_Kind
18625 return Constraint_Kind = N_Range_Constraint;
18627 when Decimal_Fixed_Point_Kind =>
18628 return Nkind_In (Constraint_Kind, N_Digits_Constraint,
18629 N_Range_Constraint);
18631 when Ordinary_Fixed_Point_Kind =>
18632 return Nkind_In (Constraint_Kind, N_Delta_Constraint,
18633 N_Range_Constraint);
18635 when Float_Kind =>
18636 return Nkind_In (Constraint_Kind, N_Digits_Constraint,
18637 N_Range_Constraint);
18639 when Access_Kind
18640 | Array_Kind
18641 | Class_Wide_Kind
18642 | Concurrent_Kind
18643 | Private_Kind
18644 | E_Incomplete_Type
18645 | E_Record_Subtype
18646 | E_Record_Type
18648 return Constraint_Kind = N_Index_Or_Discriminant_Constraint;
18650 when others =>
18651 return True; -- Error will be detected later
18652 end case;
18653 end Is_Valid_Constraint_Kind;
18655 --------------------------
18656 -- Is_Visible_Component --
18657 --------------------------
18659 function Is_Visible_Component
18660 (C : Entity_Id;
18661 N : Node_Id := Empty) return Boolean
18663 Original_Comp : Entity_Id := Empty;
18664 Original_Type : Entity_Id;
18665 Type_Scope : Entity_Id;
18667 function Is_Local_Type (Typ : Entity_Id) return Boolean;
18668 -- Check whether parent type of inherited component is declared locally,
18669 -- possibly within a nested package or instance. The current scope is
18670 -- the derived record itself.
18672 -------------------
18673 -- Is_Local_Type --
18674 -------------------
18676 function Is_Local_Type (Typ : Entity_Id) return Boolean is
18677 Scop : Entity_Id;
18679 begin
18680 Scop := Scope (Typ);
18681 while Present (Scop)
18682 and then Scop /= Standard_Standard
18683 loop
18684 if Scop = Scope (Current_Scope) then
18685 return True;
18686 end if;
18688 Scop := Scope (Scop);
18689 end loop;
18691 return False;
18692 end Is_Local_Type;
18694 -- Start of processing for Is_Visible_Component
18696 begin
18697 if Ekind_In (C, E_Component, E_Discriminant) then
18698 Original_Comp := Original_Record_Component (C);
18699 end if;
18701 if No (Original_Comp) then
18703 -- Premature usage, or previous error
18705 return False;
18707 else
18708 Original_Type := Scope (Original_Comp);
18709 Type_Scope := Scope (Base_Type (Scope (C)));
18710 end if;
18712 -- This test only concerns tagged types
18714 if not Is_Tagged_Type (Original_Type) then
18715 return True;
18717 -- If it is _Parent or _Tag, there is no visibility issue
18719 elsif not Comes_From_Source (Original_Comp) then
18720 return True;
18722 -- Discriminants are visible unless the (private) type has unknown
18723 -- discriminants. If the discriminant reference is inserted for a
18724 -- discriminant check on a full view it is also visible.
18726 elsif Ekind (Original_Comp) = E_Discriminant
18727 and then
18728 (not Has_Unknown_Discriminants (Original_Type)
18729 or else (Present (N)
18730 and then Nkind (N) = N_Selected_Component
18731 and then Nkind (Prefix (N)) = N_Type_Conversion
18732 and then not Comes_From_Source (Prefix (N))))
18733 then
18734 return True;
18736 -- In the body of an instantiation, check the visibility of a component
18737 -- in case it has a homograph that is a primitive operation of a private
18738 -- type which was not visible in the generic unit.
18740 -- Should Is_Prefixed_Call be propagated from template to instance???
18742 elsif In_Instance_Body then
18743 if not Is_Tagged_Type (Original_Type)
18744 or else not Is_Private_Type (Original_Type)
18745 then
18746 return True;
18748 else
18749 declare
18750 Subp_Elmt : Elmt_Id;
18752 begin
18753 Subp_Elmt := First_Elmt (Primitive_Operations (Original_Type));
18754 while Present (Subp_Elmt) loop
18756 -- The component is hidden by a primitive operation
18758 if Chars (Node (Subp_Elmt)) = Chars (C) then
18759 return False;
18760 end if;
18762 Next_Elmt (Subp_Elmt);
18763 end loop;
18765 return True;
18766 end;
18767 end if;
18769 -- If the component has been declared in an ancestor which is currently
18770 -- a private type, then it is not visible. The same applies if the
18771 -- component's containing type is not in an open scope and the original
18772 -- component's enclosing type is a visible full view of a private type
18773 -- (which can occur in cases where an attempt is being made to reference
18774 -- a component in a sibling package that is inherited from a visible
18775 -- component of a type in an ancestor package; the component in the
18776 -- sibling package should not be visible even though the component it
18777 -- inherited from is visible). This does not apply however in the case
18778 -- where the scope of the type is a private child unit, or when the
18779 -- parent comes from a local package in which the ancestor is currently
18780 -- visible. The latter suppression of visibility is needed for cases
18781 -- that are tested in B730006.
18783 elsif Is_Private_Type (Original_Type)
18784 or else
18785 (not Is_Private_Descendant (Type_Scope)
18786 and then not In_Open_Scopes (Type_Scope)
18787 and then Has_Private_Declaration (Original_Type))
18788 then
18789 -- If the type derives from an entity in a formal package, there
18790 -- are no additional visible components.
18792 if Nkind (Original_Node (Unit_Declaration_Node (Type_Scope))) =
18793 N_Formal_Package_Declaration
18794 then
18795 return False;
18797 -- if we are not in the private part of the current package, there
18798 -- are no additional visible components.
18800 elsif Ekind (Scope (Current_Scope)) = E_Package
18801 and then not In_Private_Part (Scope (Current_Scope))
18802 then
18803 return False;
18804 else
18805 return
18806 Is_Child_Unit (Cunit_Entity (Current_Sem_Unit))
18807 and then In_Open_Scopes (Scope (Original_Type))
18808 and then Is_Local_Type (Type_Scope);
18809 end if;
18811 -- There is another weird way in which a component may be invisible when
18812 -- the private and the full view are not derived from the same ancestor.
18813 -- Here is an example :
18815 -- type A1 is tagged record F1 : integer; end record;
18816 -- type A2 is new A1 with record F2 : integer; end record;
18817 -- type T is new A1 with private;
18818 -- private
18819 -- type T is new A2 with null record;
18821 -- In this case, the full view of T inherits F1 and F2 but the private
18822 -- view inherits only F1
18824 else
18825 declare
18826 Ancestor : Entity_Id := Scope (C);
18828 begin
18829 loop
18830 if Ancestor = Original_Type then
18831 return True;
18833 -- The ancestor may have a partial view of the original type,
18834 -- but if the full view is in scope, as in a child body, the
18835 -- component is visible.
18837 elsif In_Private_Part (Scope (Original_Type))
18838 and then Full_View (Ancestor) = Original_Type
18839 then
18840 return True;
18842 elsif Ancestor = Etype (Ancestor) then
18844 -- No further ancestors to examine
18846 return False;
18847 end if;
18849 Ancestor := Etype (Ancestor);
18850 end loop;
18851 end;
18852 end if;
18853 end Is_Visible_Component;
18855 --------------------------
18856 -- Make_Class_Wide_Type --
18857 --------------------------
18859 procedure Make_Class_Wide_Type (T : Entity_Id) is
18860 CW_Type : Entity_Id;
18861 CW_Name : Name_Id;
18862 Next_E : Entity_Id;
18864 begin
18865 if Present (Class_Wide_Type (T)) then
18867 -- The class-wide type is a partially decorated entity created for a
18868 -- unanalyzed tagged type referenced through a limited with clause.
18869 -- When the tagged type is analyzed, its class-wide type needs to be
18870 -- redecorated. Note that we reuse the entity created by Decorate_
18871 -- Tagged_Type in order to preserve all links.
18873 if Materialize_Entity (Class_Wide_Type (T)) then
18874 CW_Type := Class_Wide_Type (T);
18875 Set_Materialize_Entity (CW_Type, False);
18877 -- The class wide type can have been defined by the partial view, in
18878 -- which case everything is already done.
18880 else
18881 return;
18882 end if;
18884 -- Default case, we need to create a new class-wide type
18886 else
18887 CW_Type :=
18888 New_External_Entity (E_Void, Scope (T), Sloc (T), T, 'C', 0, 'T');
18889 end if;
18891 -- Inherit root type characteristics
18893 CW_Name := Chars (CW_Type);
18894 Next_E := Next_Entity (CW_Type);
18895 Copy_Node (T, CW_Type);
18896 Set_Comes_From_Source (CW_Type, False);
18897 Set_Chars (CW_Type, CW_Name);
18898 Set_Parent (CW_Type, Parent (T));
18899 Set_Next_Entity (CW_Type, Next_E);
18901 -- Ensure we have a new freeze node for the class-wide type. The partial
18902 -- view may have freeze action of its own, requiring a proper freeze
18903 -- node, and the same freeze node cannot be shared between the two
18904 -- types.
18906 Set_Has_Delayed_Freeze (CW_Type);
18907 Set_Freeze_Node (CW_Type, Empty);
18909 -- Customize the class-wide type: It has no prim. op., it cannot be
18910 -- abstract, its Etype points back to the specific root type, and it
18911 -- cannot have any invariants.
18913 Set_Ekind (CW_Type, E_Class_Wide_Type);
18914 Set_Is_Tagged_Type (CW_Type, True);
18915 Set_Direct_Primitive_Operations (CW_Type, New_Elmt_List);
18916 Set_Is_Abstract_Type (CW_Type, False);
18917 Set_Is_Constrained (CW_Type, False);
18918 Set_Is_First_Subtype (CW_Type, Is_First_Subtype (T));
18919 Set_Default_SSO (CW_Type);
18920 Set_Has_Inheritable_Invariants (CW_Type, False);
18921 Set_Has_Inherited_Invariants (CW_Type, False);
18922 Set_Has_Own_Invariants (CW_Type, False);
18924 if Ekind (T) = E_Class_Wide_Subtype then
18925 Set_Etype (CW_Type, Etype (Base_Type (T)));
18926 else
18927 Set_Etype (CW_Type, T);
18928 end if;
18930 Set_No_Tagged_Streams_Pragma (CW_Type, No_Tagged_Streams);
18932 -- If this is the class_wide type of a constrained subtype, it does
18933 -- not have discriminants.
18935 Set_Has_Discriminants (CW_Type,
18936 Has_Discriminants (T) and then not Is_Constrained (T));
18938 Set_Has_Unknown_Discriminants (CW_Type, True);
18939 Set_Class_Wide_Type (T, CW_Type);
18940 Set_Equivalent_Type (CW_Type, Empty);
18942 -- The class-wide type of a class-wide type is itself (RM 3.9(14))
18944 Set_Class_Wide_Type (CW_Type, CW_Type);
18945 end Make_Class_Wide_Type;
18947 ----------------
18948 -- Make_Index --
18949 ----------------
18951 procedure Make_Index
18952 (N : Node_Id;
18953 Related_Nod : Node_Id;
18954 Related_Id : Entity_Id := Empty;
18955 Suffix_Index : Nat := 1;
18956 In_Iter_Schm : Boolean := False)
18958 R : Node_Id;
18959 T : Entity_Id;
18960 Def_Id : Entity_Id := Empty;
18961 Found : Boolean := False;
18963 begin
18964 -- For a discrete range used in a constrained array definition and
18965 -- defined by a range, an implicit conversion to the predefined type
18966 -- INTEGER is assumed if each bound is either a numeric literal, a named
18967 -- number, or an attribute, and the type of both bounds (prior to the
18968 -- implicit conversion) is the type universal_integer. Otherwise, both
18969 -- bounds must be of the same discrete type, other than universal
18970 -- integer; this type must be determinable independently of the
18971 -- context, but using the fact that the type must be discrete and that
18972 -- both bounds must have the same type.
18974 -- Character literals also have a universal type in the absence of
18975 -- of additional context, and are resolved to Standard_Character.
18977 if Nkind (N) = N_Range then
18979 -- The index is given by a range constraint. The bounds are known
18980 -- to be of a consistent type.
18982 if not Is_Overloaded (N) then
18983 T := Etype (N);
18985 -- For universal bounds, choose the specific predefined type
18987 if T = Universal_Integer then
18988 T := Standard_Integer;
18990 elsif T = Any_Character then
18991 Ambiguous_Character (Low_Bound (N));
18993 T := Standard_Character;
18994 end if;
18996 -- The node may be overloaded because some user-defined operators
18997 -- are available, but if a universal interpretation exists it is
18998 -- also the selected one.
19000 elsif Universal_Interpretation (N) = Universal_Integer then
19001 T := Standard_Integer;
19003 else
19004 T := Any_Type;
19006 declare
19007 Ind : Interp_Index;
19008 It : Interp;
19010 begin
19011 Get_First_Interp (N, Ind, It);
19012 while Present (It.Typ) loop
19013 if Is_Discrete_Type (It.Typ) then
19015 if Found
19016 and then not Covers (It.Typ, T)
19017 and then not Covers (T, It.Typ)
19018 then
19019 Error_Msg_N ("ambiguous bounds in discrete range", N);
19020 exit;
19021 else
19022 T := It.Typ;
19023 Found := True;
19024 end if;
19025 end if;
19027 Get_Next_Interp (Ind, It);
19028 end loop;
19030 if T = Any_Type then
19031 Error_Msg_N ("discrete type required for range", N);
19032 Set_Etype (N, Any_Type);
19033 return;
19035 elsif T = Universal_Integer then
19036 T := Standard_Integer;
19037 end if;
19038 end;
19039 end if;
19041 if not Is_Discrete_Type (T) then
19042 Error_Msg_N ("discrete type required for range", N);
19043 Set_Etype (N, Any_Type);
19044 return;
19045 end if;
19047 if Nkind (Low_Bound (N)) = N_Attribute_Reference
19048 and then Attribute_Name (Low_Bound (N)) = Name_First
19049 and then Is_Entity_Name (Prefix (Low_Bound (N)))
19050 and then Is_Type (Entity (Prefix (Low_Bound (N))))
19051 and then Is_Discrete_Type (Entity (Prefix (Low_Bound (N))))
19052 then
19053 -- The type of the index will be the type of the prefix, as long
19054 -- as the upper bound is 'Last of the same type.
19056 Def_Id := Entity (Prefix (Low_Bound (N)));
19058 if Nkind (High_Bound (N)) /= N_Attribute_Reference
19059 or else Attribute_Name (High_Bound (N)) /= Name_Last
19060 or else not Is_Entity_Name (Prefix (High_Bound (N)))
19061 or else Entity (Prefix (High_Bound (N))) /= Def_Id
19062 then
19063 Def_Id := Empty;
19064 end if;
19065 end if;
19067 R := N;
19068 Process_Range_Expr_In_Decl (R, T, In_Iter_Schm => In_Iter_Schm);
19070 elsif Nkind (N) = N_Subtype_Indication then
19072 -- The index is given by a subtype with a range constraint
19074 T := Base_Type (Entity (Subtype_Mark (N)));
19076 if not Is_Discrete_Type (T) then
19077 Error_Msg_N ("discrete type required for range", N);
19078 Set_Etype (N, Any_Type);
19079 return;
19080 end if;
19082 R := Range_Expression (Constraint (N));
19084 Resolve (R, T);
19085 Process_Range_Expr_In_Decl
19086 (R, Entity (Subtype_Mark (N)), In_Iter_Schm => In_Iter_Schm);
19088 elsif Nkind (N) = N_Attribute_Reference then
19090 -- Catch beginner's error (use of attribute other than 'Range)
19092 if Attribute_Name (N) /= Name_Range then
19093 Error_Msg_N ("expect attribute ''Range", N);
19094 Set_Etype (N, Any_Type);
19095 return;
19096 end if;
19098 -- If the node denotes the range of a type mark, that is also the
19099 -- resulting type, and we do not need to create an Itype for it.
19101 if Is_Entity_Name (Prefix (N))
19102 and then Comes_From_Source (N)
19103 and then Is_Type (Entity (Prefix (N)))
19104 and then Is_Discrete_Type (Entity (Prefix (N)))
19105 then
19106 Def_Id := Entity (Prefix (N));
19107 end if;
19109 Analyze_And_Resolve (N);
19110 T := Etype (N);
19111 R := N;
19113 -- If none of the above, must be a subtype. We convert this to a
19114 -- range attribute reference because in the case of declared first
19115 -- named subtypes, the types in the range reference can be different
19116 -- from the type of the entity. A range attribute normalizes the
19117 -- reference and obtains the correct types for the bounds.
19119 -- This transformation is in the nature of an expansion, is only
19120 -- done if expansion is active. In particular, it is not done on
19121 -- formal generic types, because we need to retain the name of the
19122 -- original index for instantiation purposes.
19124 else
19125 if not Is_Entity_Name (N) or else not Is_Type (Entity (N)) then
19126 Error_Msg_N ("invalid subtype mark in discrete range ", N);
19127 Set_Etype (N, Any_Integer);
19128 return;
19130 else
19131 -- The type mark may be that of an incomplete type. It is only
19132 -- now that we can get the full view, previous analysis does
19133 -- not look specifically for a type mark.
19135 Set_Entity (N, Get_Full_View (Entity (N)));
19136 Set_Etype (N, Entity (N));
19137 Def_Id := Entity (N);
19139 if not Is_Discrete_Type (Def_Id) then
19140 Error_Msg_N ("discrete type required for index", N);
19141 Set_Etype (N, Any_Type);
19142 return;
19143 end if;
19144 end if;
19146 if Expander_Active then
19147 Rewrite (N,
19148 Make_Attribute_Reference (Sloc (N),
19149 Attribute_Name => Name_Range,
19150 Prefix => Relocate_Node (N)));
19152 -- The original was a subtype mark that does not freeze. This
19153 -- means that the rewritten version must not freeze either.
19155 Set_Must_Not_Freeze (N);
19156 Set_Must_Not_Freeze (Prefix (N));
19157 Analyze_And_Resolve (N);
19158 T := Etype (N);
19159 R := N;
19161 -- If expander is inactive, type is legal, nothing else to construct
19163 else
19164 return;
19165 end if;
19166 end if;
19168 if not Is_Discrete_Type (T) then
19169 Error_Msg_N ("discrete type required for range", N);
19170 Set_Etype (N, Any_Type);
19171 return;
19173 elsif T = Any_Type then
19174 Set_Etype (N, Any_Type);
19175 return;
19176 end if;
19178 -- We will now create the appropriate Itype to describe the range, but
19179 -- first a check. If we originally had a subtype, then we just label
19180 -- the range with this subtype. Not only is there no need to construct
19181 -- a new subtype, but it is wrong to do so for two reasons:
19183 -- 1. A legality concern, if we have a subtype, it must not freeze,
19184 -- and the Itype would cause freezing incorrectly
19186 -- 2. An efficiency concern, if we created an Itype, it would not be
19187 -- recognized as the same type for the purposes of eliminating
19188 -- checks in some circumstances.
19190 -- We signal this case by setting the subtype entity in Def_Id
19192 if No (Def_Id) then
19193 Def_Id :=
19194 Create_Itype (E_Void, Related_Nod, Related_Id, 'D', Suffix_Index);
19195 Set_Etype (Def_Id, Base_Type (T));
19197 if Is_Signed_Integer_Type (T) then
19198 Set_Ekind (Def_Id, E_Signed_Integer_Subtype);
19200 elsif Is_Modular_Integer_Type (T) then
19201 Set_Ekind (Def_Id, E_Modular_Integer_Subtype);
19203 else
19204 Set_Ekind (Def_Id, E_Enumeration_Subtype);
19205 Set_Is_Character_Type (Def_Id, Is_Character_Type (T));
19206 Set_First_Literal (Def_Id, First_Literal (T));
19207 end if;
19209 Set_Size_Info (Def_Id, (T));
19210 Set_RM_Size (Def_Id, RM_Size (T));
19211 Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
19213 Set_Scalar_Range (Def_Id, R);
19214 Conditional_Delay (Def_Id, T);
19216 if Nkind (N) = N_Subtype_Indication then
19217 Inherit_Predicate_Flags (Def_Id, Entity (Subtype_Mark (N)));
19218 end if;
19220 -- In the subtype indication case, if the immediate parent of the
19221 -- new subtype is non-static, then the subtype we create is non-
19222 -- static, even if its bounds are static.
19224 if Nkind (N) = N_Subtype_Indication
19225 and then not Is_OK_Static_Subtype (Entity (Subtype_Mark (N)))
19226 then
19227 Set_Is_Non_Static_Subtype (Def_Id);
19228 end if;
19229 end if;
19231 -- Final step is to label the index with this constructed type
19233 Set_Etype (N, Def_Id);
19234 end Make_Index;
19236 ------------------------------
19237 -- Modular_Type_Declaration --
19238 ------------------------------
19240 procedure Modular_Type_Declaration (T : Entity_Id; Def : Node_Id) is
19241 Mod_Expr : constant Node_Id := Expression (Def);
19242 M_Val : Uint;
19244 procedure Set_Modular_Size (Bits : Int);
19245 -- Sets RM_Size to Bits, and Esize to normal word size above this
19247 ----------------------
19248 -- Set_Modular_Size --
19249 ----------------------
19251 procedure Set_Modular_Size (Bits : Int) is
19252 begin
19253 Set_RM_Size (T, UI_From_Int (Bits));
19255 if Bits <= 8 then
19256 Init_Esize (T, 8);
19258 elsif Bits <= 16 then
19259 Init_Esize (T, 16);
19261 elsif Bits <= 32 then
19262 Init_Esize (T, 32);
19264 else
19265 Init_Esize (T, System_Max_Binary_Modulus_Power);
19266 end if;
19268 if not Non_Binary_Modulus (T) and then Esize (T) = RM_Size (T) then
19269 Set_Is_Known_Valid (T);
19270 end if;
19271 end Set_Modular_Size;
19273 -- Start of processing for Modular_Type_Declaration
19275 begin
19276 -- If the mod expression is (exactly) 2 * literal, where literal is
19277 -- 64 or less,then almost certainly the * was meant to be **. Warn.
19279 if Warn_On_Suspicious_Modulus_Value
19280 and then Nkind (Mod_Expr) = N_Op_Multiply
19281 and then Nkind (Left_Opnd (Mod_Expr)) = N_Integer_Literal
19282 and then Intval (Left_Opnd (Mod_Expr)) = Uint_2
19283 and then Nkind (Right_Opnd (Mod_Expr)) = N_Integer_Literal
19284 and then Intval (Right_Opnd (Mod_Expr)) <= Uint_64
19285 then
19286 Error_Msg_N
19287 ("suspicious MOD value, was '*'* intended'??M?", Mod_Expr);
19288 end if;
19290 -- Proceed with analysis of mod expression
19292 Analyze_And_Resolve (Mod_Expr, Any_Integer);
19293 Set_Etype (T, T);
19294 Set_Ekind (T, E_Modular_Integer_Type);
19295 Init_Alignment (T);
19296 Set_Is_Constrained (T);
19298 if not Is_OK_Static_Expression (Mod_Expr) then
19299 Flag_Non_Static_Expr
19300 ("non-static expression used for modular type bound!", Mod_Expr);
19301 M_Val := 2 ** System_Max_Binary_Modulus_Power;
19302 else
19303 M_Val := Expr_Value (Mod_Expr);
19304 end if;
19306 if M_Val < 1 then
19307 Error_Msg_N ("modulus value must be positive", Mod_Expr);
19308 M_Val := 2 ** System_Max_Binary_Modulus_Power;
19309 end if;
19311 if M_Val > 2 ** Standard_Long_Integer_Size then
19312 Check_Restriction (No_Long_Long_Integers, Mod_Expr);
19313 end if;
19315 Set_Modulus (T, M_Val);
19317 -- Create bounds for the modular type based on the modulus given in
19318 -- the type declaration and then analyze and resolve those bounds.
19320 Set_Scalar_Range (T,
19321 Make_Range (Sloc (Mod_Expr),
19322 Low_Bound => Make_Integer_Literal (Sloc (Mod_Expr), 0),
19323 High_Bound => Make_Integer_Literal (Sloc (Mod_Expr), M_Val - 1)));
19325 -- Properly analyze the literals for the range. We do this manually
19326 -- because we can't go calling Resolve, since we are resolving these
19327 -- bounds with the type, and this type is certainly not complete yet.
19329 Set_Etype (Low_Bound (Scalar_Range (T)), T);
19330 Set_Etype (High_Bound (Scalar_Range (T)), T);
19331 Set_Is_Static_Expression (Low_Bound (Scalar_Range (T)));
19332 Set_Is_Static_Expression (High_Bound (Scalar_Range (T)));
19334 -- Loop through powers of two to find number of bits required
19336 for Bits in Int range 0 .. System_Max_Binary_Modulus_Power loop
19338 -- Binary case
19340 if M_Val = 2 ** Bits then
19341 Set_Modular_Size (Bits);
19342 return;
19344 -- Nonbinary case
19346 elsif M_Val < 2 ** Bits then
19347 Check_SPARK_05_Restriction ("modulus should be a power of 2", T);
19348 Set_Non_Binary_Modulus (T);
19350 if Bits > System_Max_Nonbinary_Modulus_Power then
19351 Error_Msg_Uint_1 :=
19352 UI_From_Int (System_Max_Nonbinary_Modulus_Power);
19353 Error_Msg_F
19354 ("nonbinary modulus exceeds limit (2 '*'*^ - 1)", Mod_Expr);
19355 Set_Modular_Size (System_Max_Binary_Modulus_Power);
19356 return;
19358 else
19359 -- In the nonbinary case, set size as per RM 13.3(55)
19361 Set_Modular_Size (Bits);
19362 return;
19363 end if;
19364 end if;
19366 end loop;
19368 -- If we fall through, then the size exceed System.Max_Binary_Modulus
19369 -- so we just signal an error and set the maximum size.
19371 Error_Msg_Uint_1 := UI_From_Int (System_Max_Binary_Modulus_Power);
19372 Error_Msg_F ("modulus exceeds limit (2 '*'*^)", Mod_Expr);
19374 Set_Modular_Size (System_Max_Binary_Modulus_Power);
19375 Init_Alignment (T);
19377 end Modular_Type_Declaration;
19379 --------------------------
19380 -- New_Concatenation_Op --
19381 --------------------------
19383 procedure New_Concatenation_Op (Typ : Entity_Id) is
19384 Loc : constant Source_Ptr := Sloc (Typ);
19385 Op : Entity_Id;
19387 function Make_Op_Formal (Typ, Op : Entity_Id) return Entity_Id;
19388 -- Create abbreviated declaration for the formal of a predefined
19389 -- Operator 'Op' of type 'Typ'
19391 --------------------
19392 -- Make_Op_Formal --
19393 --------------------
19395 function Make_Op_Formal (Typ, Op : Entity_Id) return Entity_Id is
19396 Formal : Entity_Id;
19397 begin
19398 Formal := New_Internal_Entity (E_In_Parameter, Op, Loc, 'P');
19399 Set_Etype (Formal, Typ);
19400 Set_Mechanism (Formal, Default_Mechanism);
19401 return Formal;
19402 end Make_Op_Formal;
19404 -- Start of processing for New_Concatenation_Op
19406 begin
19407 Op := Make_Defining_Operator_Symbol (Loc, Name_Op_Concat);
19409 Set_Ekind (Op, E_Operator);
19410 Set_Scope (Op, Current_Scope);
19411 Set_Etype (Op, Typ);
19412 Set_Homonym (Op, Get_Name_Entity_Id (Name_Op_Concat));
19413 Set_Is_Immediately_Visible (Op);
19414 Set_Is_Intrinsic_Subprogram (Op);
19415 Set_Has_Completion (Op);
19416 Append_Entity (Op, Current_Scope);
19418 Set_Name_Entity_Id (Name_Op_Concat, Op);
19420 Append_Entity (Make_Op_Formal (Typ, Op), Op);
19421 Append_Entity (Make_Op_Formal (Typ, Op), Op);
19422 end New_Concatenation_Op;
19424 -------------------------
19425 -- OK_For_Limited_Init --
19426 -------------------------
19428 -- ???Check all calls of this, and compare the conditions under which it's
19429 -- called.
19431 function OK_For_Limited_Init
19432 (Typ : Entity_Id;
19433 Exp : Node_Id) return Boolean
19435 begin
19436 return Is_CPP_Constructor_Call (Exp)
19437 or else (Ada_Version >= Ada_2005
19438 and then not Debug_Flag_Dot_L
19439 and then OK_For_Limited_Init_In_05 (Typ, Exp));
19440 end OK_For_Limited_Init;
19442 -------------------------------
19443 -- OK_For_Limited_Init_In_05 --
19444 -------------------------------
19446 function OK_For_Limited_Init_In_05
19447 (Typ : Entity_Id;
19448 Exp : Node_Id) return Boolean
19450 begin
19451 -- An object of a limited interface type can be initialized with any
19452 -- expression of a nonlimited descendant type. However this does not
19453 -- apply if this is a view conversion of some other expression. This
19454 -- is checked below.
19456 if Is_Class_Wide_Type (Typ)
19457 and then Is_Limited_Interface (Typ)
19458 and then not Is_Limited_Type (Etype (Exp))
19459 and then Nkind (Exp) /= N_Type_Conversion
19460 then
19461 return True;
19462 end if;
19464 -- Ada 2005 (AI-287, AI-318): Relax the strictness of the front end in
19465 -- case of limited aggregates (including extension aggregates), and
19466 -- function calls. The function call may have been given in prefixed
19467 -- notation, in which case the original node is an indexed component.
19468 -- If the function is parameterless, the original node was an explicit
19469 -- dereference. The function may also be parameterless, in which case
19470 -- the source node is just an identifier.
19472 -- A branch of a conditional expression may have been removed if the
19473 -- condition is statically known. This happens during expansion, and
19474 -- thus will not happen if previous errors were encountered. The check
19475 -- will have been performed on the chosen branch, which replaces the
19476 -- original conditional expression.
19478 if No (Exp) then
19479 return True;
19480 end if;
19482 case Nkind (Original_Node (Exp)) is
19483 when N_Aggregate
19484 | N_Extension_Aggregate
19485 | N_Function_Call
19486 | N_Op
19488 return True;
19490 when N_Identifier =>
19491 return Present (Entity (Original_Node (Exp)))
19492 and then Ekind (Entity (Original_Node (Exp))) = E_Function;
19494 when N_Qualified_Expression =>
19495 return
19496 OK_For_Limited_Init_In_05
19497 (Typ, Expression (Original_Node (Exp)));
19499 -- Ada 2005 (AI-251): If a class-wide interface object is initialized
19500 -- with a function call, the expander has rewritten the call into an
19501 -- N_Type_Conversion node to force displacement of the pointer to
19502 -- reference the component containing the secondary dispatch table.
19503 -- Otherwise a type conversion is not a legal context.
19504 -- A return statement for a build-in-place function returning a
19505 -- synchronized type also introduces an unchecked conversion.
19507 when N_Type_Conversion
19508 | N_Unchecked_Type_Conversion
19510 return not Comes_From_Source (Exp)
19511 and then
19512 OK_For_Limited_Init_In_05
19513 (Typ, Expression (Original_Node (Exp)));
19515 when N_Explicit_Dereference
19516 | N_Indexed_Component
19517 | N_Selected_Component
19519 return Nkind (Exp) = N_Function_Call;
19521 -- A use of 'Input is a function call, hence allowed. Normally the
19522 -- attribute will be changed to a call, but the attribute by itself
19523 -- can occur with -gnatc.
19525 when N_Attribute_Reference =>
19526 return Attribute_Name (Original_Node (Exp)) = Name_Input;
19528 -- "return raise ..." is OK
19530 when N_Raise_Expression =>
19531 return True;
19533 -- For a case expression, all dependent expressions must be legal
19535 when N_Case_Expression =>
19536 declare
19537 Alt : Node_Id;
19539 begin
19540 Alt := First (Alternatives (Original_Node (Exp)));
19541 while Present (Alt) loop
19542 if not OK_For_Limited_Init_In_05 (Typ, Expression (Alt)) then
19543 return False;
19544 end if;
19546 Next (Alt);
19547 end loop;
19549 return True;
19550 end;
19552 -- For an if expression, all dependent expressions must be legal
19554 when N_If_Expression =>
19555 declare
19556 Then_Expr : constant Node_Id :=
19557 Next (First (Expressions (Original_Node (Exp))));
19558 Else_Expr : constant Node_Id := Next (Then_Expr);
19559 begin
19560 return OK_For_Limited_Init_In_05 (Typ, Then_Expr)
19561 and then
19562 OK_For_Limited_Init_In_05 (Typ, Else_Expr);
19563 end;
19565 when others =>
19566 return False;
19567 end case;
19568 end OK_For_Limited_Init_In_05;
19570 -------------------------------------------
19571 -- Ordinary_Fixed_Point_Type_Declaration --
19572 -------------------------------------------
19574 procedure Ordinary_Fixed_Point_Type_Declaration
19575 (T : Entity_Id;
19576 Def : Node_Id)
19578 Loc : constant Source_Ptr := Sloc (Def);
19579 Delta_Expr : constant Node_Id := Delta_Expression (Def);
19580 RRS : constant Node_Id := Real_Range_Specification (Def);
19581 Implicit_Base : Entity_Id;
19582 Delta_Val : Ureal;
19583 Small_Val : Ureal;
19584 Low_Val : Ureal;
19585 High_Val : Ureal;
19587 begin
19588 Check_Restriction (No_Fixed_Point, Def);
19590 -- Create implicit base type
19592 Implicit_Base :=
19593 Create_Itype (E_Ordinary_Fixed_Point_Type, Parent (Def), T, 'B');
19594 Set_Etype (Implicit_Base, Implicit_Base);
19596 -- Analyze and process delta expression
19598 Analyze_And_Resolve (Delta_Expr, Any_Real);
19600 Check_Delta_Expression (Delta_Expr);
19601 Delta_Val := Expr_Value_R (Delta_Expr);
19603 Set_Delta_Value (Implicit_Base, Delta_Val);
19605 -- Compute default small from given delta, which is the largest power
19606 -- of two that does not exceed the given delta value.
19608 declare
19609 Tmp : Ureal;
19610 Scale : Int;
19612 begin
19613 Tmp := Ureal_1;
19614 Scale := 0;
19616 if Delta_Val < Ureal_1 then
19617 while Delta_Val < Tmp loop
19618 Tmp := Tmp / Ureal_2;
19619 Scale := Scale + 1;
19620 end loop;
19622 else
19623 loop
19624 Tmp := Tmp * Ureal_2;
19625 exit when Tmp > Delta_Val;
19626 Scale := Scale - 1;
19627 end loop;
19628 end if;
19630 Small_Val := UR_From_Components (Uint_1, UI_From_Int (Scale), 2);
19631 end;
19633 Set_Small_Value (Implicit_Base, Small_Val);
19635 -- If no range was given, set a dummy range
19637 if RRS <= Empty_Or_Error then
19638 Low_Val := -Small_Val;
19639 High_Val := Small_Val;
19641 -- Otherwise analyze and process given range
19643 else
19644 declare
19645 Low : constant Node_Id := Low_Bound (RRS);
19646 High : constant Node_Id := High_Bound (RRS);
19648 begin
19649 Analyze_And_Resolve (Low, Any_Real);
19650 Analyze_And_Resolve (High, Any_Real);
19651 Check_Real_Bound (Low);
19652 Check_Real_Bound (High);
19654 -- Obtain and set the range
19656 Low_Val := Expr_Value_R (Low);
19657 High_Val := Expr_Value_R (High);
19659 if Low_Val > High_Val then
19660 Error_Msg_NE ("??fixed point type& has null range", Def, T);
19661 end if;
19662 end;
19663 end if;
19665 -- The range for both the implicit base and the declared first subtype
19666 -- cannot be set yet, so we use the special routine Set_Fixed_Range to
19667 -- set a temporary range in place. Note that the bounds of the base
19668 -- type will be widened to be symmetrical and to fill the available
19669 -- bits when the type is frozen.
19671 -- We could do this with all discrete types, and probably should, but
19672 -- we absolutely have to do it for fixed-point, since the end-points
19673 -- of the range and the size are determined by the small value, which
19674 -- could be reset before the freeze point.
19676 Set_Fixed_Range (Implicit_Base, Loc, Low_Val, High_Val);
19677 Set_Fixed_Range (T, Loc, Low_Val, High_Val);
19679 -- Complete definition of first subtype. The inheritance of the rep item
19680 -- chain ensures that SPARK-related pragmas are not clobbered when the
19681 -- ordinary fixed point type acts as a full view of a private type.
19683 Set_Ekind (T, E_Ordinary_Fixed_Point_Subtype);
19684 Set_Etype (T, Implicit_Base);
19685 Init_Size_Align (T);
19686 Inherit_Rep_Item_Chain (T, Implicit_Base);
19687 Set_Small_Value (T, Small_Val);
19688 Set_Delta_Value (T, Delta_Val);
19689 Set_Is_Constrained (T);
19690 end Ordinary_Fixed_Point_Type_Declaration;
19692 ----------------------------------
19693 -- Preanalyze_Assert_Expression --
19694 ----------------------------------
19696 procedure Preanalyze_Assert_Expression (N : Node_Id; T : Entity_Id) is
19697 begin
19698 In_Assertion_Expr := In_Assertion_Expr + 1;
19699 Preanalyze_Spec_Expression (N, T);
19700 In_Assertion_Expr := In_Assertion_Expr - 1;
19701 end Preanalyze_Assert_Expression;
19703 -----------------------------------
19704 -- Preanalyze_Default_Expression --
19705 -----------------------------------
19707 procedure Preanalyze_Default_Expression (N : Node_Id; T : Entity_Id) is
19708 Save_In_Default_Expr : constant Boolean := In_Default_Expr;
19709 begin
19710 In_Default_Expr := True;
19711 Preanalyze_Spec_Expression (N, T);
19712 In_Default_Expr := Save_In_Default_Expr;
19713 end Preanalyze_Default_Expression;
19715 --------------------------------
19716 -- Preanalyze_Spec_Expression --
19717 --------------------------------
19719 procedure Preanalyze_Spec_Expression (N : Node_Id; T : Entity_Id) is
19720 Save_In_Spec_Expression : constant Boolean := In_Spec_Expression;
19721 begin
19722 In_Spec_Expression := True;
19723 Preanalyze_And_Resolve (N, T);
19724 In_Spec_Expression := Save_In_Spec_Expression;
19725 end Preanalyze_Spec_Expression;
19727 ----------------------------------------
19728 -- Prepare_Private_Subtype_Completion --
19729 ----------------------------------------
19731 procedure Prepare_Private_Subtype_Completion
19732 (Id : Entity_Id;
19733 Related_Nod : Node_Id)
19735 Id_B : constant Entity_Id := Base_Type (Id);
19736 Full_B : Entity_Id := Full_View (Id_B);
19737 Full : Entity_Id;
19739 begin
19740 if Present (Full_B) then
19742 -- Get to the underlying full view if necessary
19744 if Is_Private_Type (Full_B)
19745 and then Present (Underlying_Full_View (Full_B))
19746 then
19747 Full_B := Underlying_Full_View (Full_B);
19748 end if;
19750 -- The Base_Type is already completed, we can complete the subtype
19751 -- now. We have to create a new entity with the same name, Thus we
19752 -- can't use Create_Itype.
19754 Full := Make_Defining_Identifier (Sloc (Id), Chars (Id));
19755 Set_Is_Itype (Full);
19756 Set_Associated_Node_For_Itype (Full, Related_Nod);
19757 Complete_Private_Subtype (Id, Full, Full_B, Related_Nod);
19758 end if;
19760 -- The parent subtype may be private, but the base might not, in some
19761 -- nested instances. In that case, the subtype does not need to be
19762 -- exchanged. It would still be nice to make private subtypes and their
19763 -- bases consistent at all times ???
19765 if Is_Private_Type (Id_B) then
19766 Append_Elmt (Id, Private_Dependents (Id_B));
19767 end if;
19768 end Prepare_Private_Subtype_Completion;
19770 ---------------------------
19771 -- Process_Discriminants --
19772 ---------------------------
19774 procedure Process_Discriminants
19775 (N : Node_Id;
19776 Prev : Entity_Id := Empty)
19778 Elist : constant Elist_Id := New_Elmt_List;
19779 Id : Node_Id;
19780 Discr : Node_Id;
19781 Discr_Number : Uint;
19782 Discr_Type : Entity_Id;
19783 Default_Present : Boolean := False;
19784 Default_Not_Present : Boolean := False;
19786 begin
19787 -- A composite type other than an array type can have discriminants.
19788 -- On entry, the current scope is the composite type.
19790 -- The discriminants are initially entered into the scope of the type
19791 -- via Enter_Name with the default Ekind of E_Void to prevent premature
19792 -- use, as explained at the end of this procedure.
19794 Discr := First (Discriminant_Specifications (N));
19795 while Present (Discr) loop
19796 Enter_Name (Defining_Identifier (Discr));
19798 -- For navigation purposes we add a reference to the discriminant
19799 -- in the entity for the type. If the current declaration is a
19800 -- completion, place references on the partial view. Otherwise the
19801 -- type is the current scope.
19803 if Present (Prev) then
19805 -- The references go on the partial view, if present. If the
19806 -- partial view has discriminants, the references have been
19807 -- generated already.
19809 if not Has_Discriminants (Prev) then
19810 Generate_Reference (Prev, Defining_Identifier (Discr), 'd');
19811 end if;
19812 else
19813 Generate_Reference
19814 (Current_Scope, Defining_Identifier (Discr), 'd');
19815 end if;
19817 if Nkind (Discriminant_Type (Discr)) = N_Access_Definition then
19818 Discr_Type := Access_Definition (Discr, Discriminant_Type (Discr));
19820 -- Ada 2005 (AI-254)
19822 if Present (Access_To_Subprogram_Definition
19823 (Discriminant_Type (Discr)))
19824 and then Protected_Present (Access_To_Subprogram_Definition
19825 (Discriminant_Type (Discr)))
19826 then
19827 Discr_Type :=
19828 Replace_Anonymous_Access_To_Protected_Subprogram (Discr);
19829 end if;
19831 else
19832 Find_Type (Discriminant_Type (Discr));
19833 Discr_Type := Etype (Discriminant_Type (Discr));
19835 if Error_Posted (Discriminant_Type (Discr)) then
19836 Discr_Type := Any_Type;
19837 end if;
19838 end if;
19840 -- Handling of discriminants that are access types
19842 if Is_Access_Type (Discr_Type) then
19844 -- Ada 2005 (AI-230): Access discriminant allowed in non-
19845 -- limited record types
19847 if Ada_Version < Ada_2005 then
19848 Check_Access_Discriminant_Requires_Limited
19849 (Discr, Discriminant_Type (Discr));
19850 end if;
19852 if Ada_Version = Ada_83 and then Comes_From_Source (Discr) then
19853 Error_Msg_N
19854 ("(Ada 83) access discriminant not allowed", Discr);
19855 end if;
19857 -- If not access type, must be a discrete type
19859 elsif not Is_Discrete_Type (Discr_Type) then
19860 Error_Msg_N
19861 ("discriminants must have a discrete or access type",
19862 Discriminant_Type (Discr));
19863 end if;
19865 Set_Etype (Defining_Identifier (Discr), Discr_Type);
19867 -- If a discriminant specification includes the assignment compound
19868 -- delimiter followed by an expression, the expression is the default
19869 -- expression of the discriminant; the default expression must be of
19870 -- the type of the discriminant. (RM 3.7.1) Since this expression is
19871 -- a default expression, we do the special preanalysis, since this
19872 -- expression does not freeze (see section "Handling of Default and
19873 -- Per-Object Expressions" in spec of package Sem).
19875 if Present (Expression (Discr)) then
19876 Preanalyze_Spec_Expression (Expression (Discr), Discr_Type);
19878 -- Legaity checks
19880 if Nkind (N) = N_Formal_Type_Declaration then
19881 Error_Msg_N
19882 ("discriminant defaults not allowed for formal type",
19883 Expression (Discr));
19885 -- Flag an error for a tagged type with defaulted discriminants,
19886 -- excluding limited tagged types when compiling for Ada 2012
19887 -- (see AI05-0214).
19889 elsif Is_Tagged_Type (Current_Scope)
19890 and then (not Is_Limited_Type (Current_Scope)
19891 or else Ada_Version < Ada_2012)
19892 and then Comes_From_Source (N)
19893 then
19894 -- Note: see similar test in Check_Or_Process_Discriminants, to
19895 -- handle the (illegal) case of the completion of an untagged
19896 -- view with discriminants with defaults by a tagged full view.
19897 -- We skip the check if Discr does not come from source, to
19898 -- account for the case of an untagged derived type providing
19899 -- defaults for a renamed discriminant from a private untagged
19900 -- ancestor with a tagged full view (ACATS B460006).
19902 if Ada_Version >= Ada_2012 then
19903 Error_Msg_N
19904 ("discriminants of nonlimited tagged type cannot have"
19905 & " defaults",
19906 Expression (Discr));
19907 else
19908 Error_Msg_N
19909 ("discriminants of tagged type cannot have defaults",
19910 Expression (Discr));
19911 end if;
19913 else
19914 Default_Present := True;
19915 Append_Elmt (Expression (Discr), Elist);
19917 -- Tag the defining identifiers for the discriminants with
19918 -- their corresponding default expressions from the tree.
19920 Set_Discriminant_Default_Value
19921 (Defining_Identifier (Discr), Expression (Discr));
19922 end if;
19924 -- In gnatc or gnatprove mode, make sure set Do_Range_Check flag
19925 -- gets set unless we can be sure that no range check is required.
19927 if (GNATprove_Mode or not Expander_Active)
19928 and then not
19929 Is_In_Range
19930 (Expression (Discr), Discr_Type, Assume_Valid => True)
19931 then
19932 Set_Do_Range_Check (Expression (Discr));
19933 end if;
19935 -- No default discriminant value given
19937 else
19938 Default_Not_Present := True;
19939 end if;
19941 -- Ada 2005 (AI-231): Create an Itype that is a duplicate of
19942 -- Discr_Type but with the null-exclusion attribute
19944 if Ada_Version >= Ada_2005 then
19946 -- Ada 2005 (AI-231): Static checks
19948 if Can_Never_Be_Null (Discr_Type) then
19949 Null_Exclusion_Static_Checks (Discr);
19951 elsif Is_Access_Type (Discr_Type)
19952 and then Null_Exclusion_Present (Discr)
19954 -- No need to check itypes because in their case this check
19955 -- was done at their point of creation
19957 and then not Is_Itype (Discr_Type)
19958 then
19959 if Can_Never_Be_Null (Discr_Type) then
19960 Error_Msg_NE
19961 ("`NOT NULL` not allowed (& already excludes null)",
19962 Discr,
19963 Discr_Type);
19964 end if;
19966 Set_Etype (Defining_Identifier (Discr),
19967 Create_Null_Excluding_Itype
19968 (T => Discr_Type,
19969 Related_Nod => Discr));
19971 -- Check for improper null exclusion if the type is otherwise
19972 -- legal for a discriminant.
19974 elsif Null_Exclusion_Present (Discr)
19975 and then Is_Discrete_Type (Discr_Type)
19976 then
19977 Error_Msg_N
19978 ("null exclusion can only apply to an access type", Discr);
19979 end if;
19981 -- Ada 2005 (AI-402): access discriminants of nonlimited types
19982 -- can't have defaults. Synchronized types, or types that are
19983 -- explicitly limited are fine, but special tests apply to derived
19984 -- types in generics: in a generic body we have to assume the
19985 -- worst, and therefore defaults are not allowed if the parent is
19986 -- a generic formal private type (see ACATS B370001).
19988 if Is_Access_Type (Discr_Type) and then Default_Present then
19989 if Ekind (Discr_Type) /= E_Anonymous_Access_Type
19990 or else Is_Limited_Record (Current_Scope)
19991 or else Is_Concurrent_Type (Current_Scope)
19992 or else Is_Concurrent_Record_Type (Current_Scope)
19993 or else Ekind (Current_Scope) = E_Limited_Private_Type
19994 then
19995 if not Is_Derived_Type (Current_Scope)
19996 or else not Is_Generic_Type (Etype (Current_Scope))
19997 or else not In_Package_Body (Scope (Etype (Current_Scope)))
19998 or else Limited_Present
19999 (Type_Definition (Parent (Current_Scope)))
20000 then
20001 null;
20003 else
20004 Error_Msg_N
20005 ("access discriminants of nonlimited types cannot "
20006 & "have defaults", Expression (Discr));
20007 end if;
20009 elsif Present (Expression (Discr)) then
20010 Error_Msg_N
20011 ("(Ada 2005) access discriminants of nonlimited types "
20012 & "cannot have defaults", Expression (Discr));
20013 end if;
20014 end if;
20015 end if;
20017 -- A discriminant cannot be effectively volatile (SPARK RM 7.1.3(6)).
20018 -- This check is relevant only when SPARK_Mode is on as it is not a
20019 -- standard Ada legality rule.
20021 if SPARK_Mode = On
20022 and then Is_Effectively_Volatile (Defining_Identifier (Discr))
20023 then
20024 Error_Msg_N ("discriminant cannot be volatile", Discr);
20025 end if;
20027 Next (Discr);
20028 end loop;
20030 -- An element list consisting of the default expressions of the
20031 -- discriminants is constructed in the above loop and used to set
20032 -- the Discriminant_Constraint attribute for the type. If an object
20033 -- is declared of this (record or task) type without any explicit
20034 -- discriminant constraint given, this element list will form the
20035 -- actual parameters for the corresponding initialization procedure
20036 -- for the type.
20038 Set_Discriminant_Constraint (Current_Scope, Elist);
20039 Set_Stored_Constraint (Current_Scope, No_Elist);
20041 -- Default expressions must be provided either for all or for none
20042 -- of the discriminants of a discriminant part. (RM 3.7.1)
20044 if Default_Present and then Default_Not_Present then
20045 Error_Msg_N
20046 ("incomplete specification of defaults for discriminants", N);
20047 end if;
20049 -- The use of the name of a discriminant is not allowed in default
20050 -- expressions of a discriminant part if the specification of the
20051 -- discriminant is itself given in the discriminant part. (RM 3.7.1)
20053 -- To detect this, the discriminant names are entered initially with an
20054 -- Ekind of E_Void (which is the default Ekind given by Enter_Name). Any
20055 -- attempt to use a void entity (for example in an expression that is
20056 -- type-checked) produces the error message: premature usage. Now after
20057 -- completing the semantic analysis of the discriminant part, we can set
20058 -- the Ekind of all the discriminants appropriately.
20060 Discr := First (Discriminant_Specifications (N));
20061 Discr_Number := Uint_1;
20062 while Present (Discr) loop
20063 Id := Defining_Identifier (Discr);
20064 Set_Ekind (Id, E_Discriminant);
20065 Init_Component_Location (Id);
20066 Init_Esize (Id);
20067 Set_Discriminant_Number (Id, Discr_Number);
20069 -- Make sure this is always set, even in illegal programs
20071 Set_Corresponding_Discriminant (Id, Empty);
20073 -- Initialize the Original_Record_Component to the entity itself.
20074 -- Inherit_Components will propagate the right value to
20075 -- discriminants in derived record types.
20077 Set_Original_Record_Component (Id, Id);
20079 -- Create the discriminal for the discriminant
20081 Build_Discriminal (Id);
20083 Next (Discr);
20084 Discr_Number := Discr_Number + 1;
20085 end loop;
20087 Set_Has_Discriminants (Current_Scope);
20088 end Process_Discriminants;
20090 -----------------------
20091 -- Process_Full_View --
20092 -----------------------
20094 -- WARNING: This routine manages Ghost regions. Return statements must be
20095 -- replaced by gotos which jump to the end of the routine and restore the
20096 -- Ghost mode.
20098 procedure Process_Full_View (N : Node_Id; Full_T, Priv_T : Entity_Id) is
20099 procedure Collect_Implemented_Interfaces
20100 (Typ : Entity_Id;
20101 Ifaces : Elist_Id);
20102 -- Ada 2005: Gather all the interfaces that Typ directly or
20103 -- inherently implements. Duplicate entries are not added to
20104 -- the list Ifaces.
20106 ------------------------------------
20107 -- Collect_Implemented_Interfaces --
20108 ------------------------------------
20110 procedure Collect_Implemented_Interfaces
20111 (Typ : Entity_Id;
20112 Ifaces : Elist_Id)
20114 Iface : Entity_Id;
20115 Iface_Elmt : Elmt_Id;
20117 begin
20118 -- Abstract interfaces are only associated with tagged record types
20120 if not Is_Tagged_Type (Typ) or else not Is_Record_Type (Typ) then
20121 return;
20122 end if;
20124 -- Recursively climb to the ancestors
20126 if Etype (Typ) /= Typ
20128 -- Protect the frontend against wrong cyclic declarations like:
20130 -- type B is new A with private;
20131 -- type C is new A with private;
20132 -- private
20133 -- type B is new C with null record;
20134 -- type C is new B with null record;
20136 and then Etype (Typ) /= Priv_T
20137 and then Etype (Typ) /= Full_T
20138 then
20139 -- Keep separate the management of private type declarations
20141 if Ekind (Typ) = E_Record_Type_With_Private then
20143 -- Handle the following illegal usage:
20144 -- type Private_Type is tagged private;
20145 -- private
20146 -- type Private_Type is new Type_Implementing_Iface;
20148 if Present (Full_View (Typ))
20149 and then Etype (Typ) /= Full_View (Typ)
20150 then
20151 if Is_Interface (Etype (Typ)) then
20152 Append_Unique_Elmt (Etype (Typ), Ifaces);
20153 end if;
20155 Collect_Implemented_Interfaces (Etype (Typ), Ifaces);
20156 end if;
20158 -- Non-private types
20160 else
20161 if Is_Interface (Etype (Typ)) then
20162 Append_Unique_Elmt (Etype (Typ), Ifaces);
20163 end if;
20165 Collect_Implemented_Interfaces (Etype (Typ), Ifaces);
20166 end if;
20167 end if;
20169 -- Handle entities in the list of abstract interfaces
20171 if Present (Interfaces (Typ)) then
20172 Iface_Elmt := First_Elmt (Interfaces (Typ));
20173 while Present (Iface_Elmt) loop
20174 Iface := Node (Iface_Elmt);
20176 pragma Assert (Is_Interface (Iface));
20178 if not Contain_Interface (Iface, Ifaces) then
20179 Append_Elmt (Iface, Ifaces);
20180 Collect_Implemented_Interfaces (Iface, Ifaces);
20181 end if;
20183 Next_Elmt (Iface_Elmt);
20184 end loop;
20185 end if;
20186 end Collect_Implemented_Interfaces;
20188 -- Local variables
20190 Saved_GM : constant Ghost_Mode_Type := Ghost_Mode;
20192 Full_Indic : Node_Id;
20193 Full_Parent : Entity_Id;
20194 Priv_Parent : Entity_Id;
20196 -- Start of processing for Process_Full_View
20198 begin
20199 Mark_And_Set_Ghost_Completion (N, Priv_T);
20201 -- First some sanity checks that must be done after semantic
20202 -- decoration of the full view and thus cannot be placed with other
20203 -- similar checks in Find_Type_Name
20205 if not Is_Limited_Type (Priv_T)
20206 and then (Is_Limited_Type (Full_T)
20207 or else Is_Limited_Composite (Full_T))
20208 then
20209 if In_Instance then
20210 null;
20211 else
20212 Error_Msg_N
20213 ("completion of nonlimited type cannot be limited", Full_T);
20214 Explain_Limited_Type (Full_T, Full_T);
20215 end if;
20217 elsif Is_Abstract_Type (Full_T)
20218 and then not Is_Abstract_Type (Priv_T)
20219 then
20220 Error_Msg_N
20221 ("completion of nonabstract type cannot be abstract", Full_T);
20223 elsif Is_Tagged_Type (Priv_T)
20224 and then Is_Limited_Type (Priv_T)
20225 and then not Is_Limited_Type (Full_T)
20226 then
20227 -- If pragma CPP_Class was applied to the private declaration
20228 -- propagate the limitedness to the full-view
20230 if Is_CPP_Class (Priv_T) then
20231 Set_Is_Limited_Record (Full_T);
20233 -- GNAT allow its own definition of Limited_Controlled to disobey
20234 -- this rule in order in ease the implementation. This test is safe
20235 -- because Root_Controlled is defined in a child of System that
20236 -- normal programs are not supposed to use.
20238 elsif Is_RTE (Etype (Full_T), RE_Root_Controlled) then
20239 Set_Is_Limited_Composite (Full_T);
20240 else
20241 Error_Msg_N
20242 ("completion of limited tagged type must be limited", Full_T);
20243 end if;
20245 elsif Is_Generic_Type (Priv_T) then
20246 Error_Msg_N ("generic type cannot have a completion", Full_T);
20247 end if;
20249 -- Check that ancestor interfaces of private and full views are
20250 -- consistent. We omit this check for synchronized types because
20251 -- they are performed on the corresponding record type when frozen.
20253 if Ada_Version >= Ada_2005
20254 and then Is_Tagged_Type (Priv_T)
20255 and then Is_Tagged_Type (Full_T)
20256 and then not Is_Concurrent_Type (Full_T)
20257 then
20258 declare
20259 Iface : Entity_Id;
20260 Priv_T_Ifaces : constant Elist_Id := New_Elmt_List;
20261 Full_T_Ifaces : constant Elist_Id := New_Elmt_List;
20263 begin
20264 Collect_Implemented_Interfaces (Priv_T, Priv_T_Ifaces);
20265 Collect_Implemented_Interfaces (Full_T, Full_T_Ifaces);
20267 -- Ada 2005 (AI-251): The partial view shall be a descendant of
20268 -- an interface type if and only if the full type is descendant
20269 -- of the interface type (AARM 7.3 (7.3/2)).
20271 Iface := Find_Hidden_Interface (Priv_T_Ifaces, Full_T_Ifaces);
20273 if Present (Iface) then
20274 Error_Msg_NE
20275 ("interface in partial view& not implemented by full type "
20276 & "(RM-2005 7.3 (7.3/2))", Full_T, Iface);
20277 end if;
20279 Iface := Find_Hidden_Interface (Full_T_Ifaces, Priv_T_Ifaces);
20281 if Present (Iface) then
20282 Error_Msg_NE
20283 ("interface & not implemented by partial view "
20284 & "(RM-2005 7.3 (7.3/2))", Full_T, Iface);
20285 end if;
20286 end;
20287 end if;
20289 if Is_Tagged_Type (Priv_T)
20290 and then Nkind (Parent (Priv_T)) = N_Private_Extension_Declaration
20291 and then Is_Derived_Type (Full_T)
20292 then
20293 Priv_Parent := Etype (Priv_T);
20295 -- The full view of a private extension may have been transformed
20296 -- into an unconstrained derived type declaration and a subtype
20297 -- declaration (see build_derived_record_type for details).
20299 if Nkind (N) = N_Subtype_Declaration then
20300 Full_Indic := Subtype_Indication (N);
20301 Full_Parent := Etype (Base_Type (Full_T));
20302 else
20303 Full_Indic := Subtype_Indication (Type_Definition (N));
20304 Full_Parent := Etype (Full_T);
20305 end if;
20307 -- Check that the parent type of the full type is a descendant of
20308 -- the ancestor subtype given in the private extension. If either
20309 -- entity has an Etype equal to Any_Type then we had some previous
20310 -- error situation [7.3(8)].
20312 if Priv_Parent = Any_Type or else Full_Parent = Any_Type then
20313 goto Leave;
20315 -- Ada 2005 (AI-251): Interfaces in the full type can be given in
20316 -- any order. Therefore we don't have to check that its parent must
20317 -- be a descendant of the parent of the private type declaration.
20319 elsif Is_Interface (Priv_Parent)
20320 and then Is_Interface (Full_Parent)
20321 then
20322 null;
20324 -- Ada 2005 (AI-251): If the parent of the private type declaration
20325 -- is an interface there is no need to check that it is an ancestor
20326 -- of the associated full type declaration. The required tests for
20327 -- this case are performed by Build_Derived_Record_Type.
20329 elsif not Is_Interface (Base_Type (Priv_Parent))
20330 and then not Is_Ancestor (Base_Type (Priv_Parent), Full_Parent)
20331 then
20332 Error_Msg_N
20333 ("parent of full type must descend from parent of private "
20334 & "extension", Full_Indic);
20336 -- First check a formal restriction, and then proceed with checking
20337 -- Ada rules. Since the formal restriction is not a serious error, we
20338 -- don't prevent further error detection for this check, hence the
20339 -- ELSE.
20341 else
20342 -- In formal mode, when completing a private extension the type
20343 -- named in the private part must be exactly the same as that
20344 -- named in the visible part.
20346 if Priv_Parent /= Full_Parent then
20347 Error_Msg_Name_1 := Chars (Priv_Parent);
20348 Check_SPARK_05_Restriction ("% expected", Full_Indic);
20349 end if;
20351 -- Check the rules of 7.3(10): if the private extension inherits
20352 -- known discriminants, then the full type must also inherit those
20353 -- discriminants from the same (ancestor) type, and the parent
20354 -- subtype of the full type must be constrained if and only if
20355 -- the ancestor subtype of the private extension is constrained.
20357 if No (Discriminant_Specifications (Parent (Priv_T)))
20358 and then not Has_Unknown_Discriminants (Priv_T)
20359 and then Has_Discriminants (Base_Type (Priv_Parent))
20360 then
20361 declare
20362 Priv_Indic : constant Node_Id :=
20363 Subtype_Indication (Parent (Priv_T));
20365 Priv_Constr : constant Boolean :=
20366 Is_Constrained (Priv_Parent)
20367 or else
20368 Nkind (Priv_Indic) = N_Subtype_Indication
20369 or else
20370 Is_Constrained (Entity (Priv_Indic));
20372 Full_Constr : constant Boolean :=
20373 Is_Constrained (Full_Parent)
20374 or else
20375 Nkind (Full_Indic) = N_Subtype_Indication
20376 or else
20377 Is_Constrained (Entity (Full_Indic));
20379 Priv_Discr : Entity_Id;
20380 Full_Discr : Entity_Id;
20382 begin
20383 Priv_Discr := First_Discriminant (Priv_Parent);
20384 Full_Discr := First_Discriminant (Full_Parent);
20385 while Present (Priv_Discr) and then Present (Full_Discr) loop
20386 if Original_Record_Component (Priv_Discr) =
20387 Original_Record_Component (Full_Discr)
20388 or else
20389 Corresponding_Discriminant (Priv_Discr) =
20390 Corresponding_Discriminant (Full_Discr)
20391 then
20392 null;
20393 else
20394 exit;
20395 end if;
20397 Next_Discriminant (Priv_Discr);
20398 Next_Discriminant (Full_Discr);
20399 end loop;
20401 if Present (Priv_Discr) or else Present (Full_Discr) then
20402 Error_Msg_N
20403 ("full view must inherit discriminants of the parent "
20404 & "type used in the private extension", Full_Indic);
20406 elsif Priv_Constr and then not Full_Constr then
20407 Error_Msg_N
20408 ("parent subtype of full type must be constrained",
20409 Full_Indic);
20411 elsif Full_Constr and then not Priv_Constr then
20412 Error_Msg_N
20413 ("parent subtype of full type must be unconstrained",
20414 Full_Indic);
20415 end if;
20416 end;
20418 -- Check the rules of 7.3(12): if a partial view has neither
20419 -- known or unknown discriminants, then the full type
20420 -- declaration shall define a definite subtype.
20422 elsif not Has_Unknown_Discriminants (Priv_T)
20423 and then not Has_Discriminants (Priv_T)
20424 and then not Is_Constrained (Full_T)
20425 then
20426 Error_Msg_N
20427 ("full view must define a constrained type if partial view "
20428 & "has no discriminants", Full_T);
20429 end if;
20431 -- ??????? Do we implement the following properly ?????
20432 -- If the ancestor subtype of a private extension has constrained
20433 -- discriminants, then the parent subtype of the full view shall
20434 -- impose a statically matching constraint on those discriminants
20435 -- [7.3(13)].
20436 end if;
20438 else
20439 -- For untagged types, verify that a type without discriminants is
20440 -- not completed with an unconstrained type. A separate error message
20441 -- is produced if the full type has defaulted discriminants.
20443 if Is_Definite_Subtype (Priv_T)
20444 and then not Is_Definite_Subtype (Full_T)
20445 then
20446 Error_Msg_Sloc := Sloc (Parent (Priv_T));
20447 Error_Msg_NE
20448 ("full view of& not compatible with declaration#",
20449 Full_T, Priv_T);
20451 if not Is_Tagged_Type (Full_T) then
20452 Error_Msg_N
20453 ("\one is constrained, the other unconstrained", Full_T);
20454 end if;
20455 end if;
20456 end if;
20458 -- AI-419: verify that the use of "limited" is consistent
20460 declare
20461 Orig_Decl : constant Node_Id := Original_Node (N);
20463 begin
20464 if Nkind (Parent (Priv_T)) = N_Private_Extension_Declaration
20465 and then Nkind (Orig_Decl) = N_Full_Type_Declaration
20466 and then Nkind
20467 (Type_Definition (Orig_Decl)) = N_Derived_Type_Definition
20468 then
20469 if not Limited_Present (Parent (Priv_T))
20470 and then not Synchronized_Present (Parent (Priv_T))
20471 and then Limited_Present (Type_Definition (Orig_Decl))
20472 then
20473 Error_Msg_N
20474 ("full view of non-limited extension cannot be limited", N);
20476 -- Conversely, if the partial view carries the limited keyword,
20477 -- the full view must as well, even if it may be redundant.
20479 elsif Limited_Present (Parent (Priv_T))
20480 and then not Limited_Present (Type_Definition (Orig_Decl))
20481 then
20482 Error_Msg_N
20483 ("full view of limited extension must be explicitly limited",
20485 end if;
20486 end if;
20487 end;
20489 -- Ada 2005 (AI-443): A synchronized private extension must be
20490 -- completed by a task or protected type.
20492 if Ada_Version >= Ada_2005
20493 and then Nkind (Parent (Priv_T)) = N_Private_Extension_Declaration
20494 and then Synchronized_Present (Parent (Priv_T))
20495 and then not Is_Concurrent_Type (Full_T)
20496 then
20497 Error_Msg_N ("full view of synchronized extension must " &
20498 "be synchronized type", N);
20499 end if;
20501 -- Ada 2005 AI-363: if the full view has discriminants with
20502 -- defaults, it is illegal to declare constrained access subtypes
20503 -- whose designated type is the current type. This allows objects
20504 -- of the type that are declared in the heap to be unconstrained.
20506 if not Has_Unknown_Discriminants (Priv_T)
20507 and then not Has_Discriminants (Priv_T)
20508 and then Has_Discriminants (Full_T)
20509 and then
20510 Present (Discriminant_Default_Value (First_Discriminant (Full_T)))
20511 then
20512 Set_Has_Constrained_Partial_View (Full_T);
20513 Set_Has_Constrained_Partial_View (Priv_T);
20514 end if;
20516 -- Create a full declaration for all its subtypes recorded in
20517 -- Private_Dependents and swap them similarly to the base type. These
20518 -- are subtypes that have been define before the full declaration of
20519 -- the private type. We also swap the entry in Private_Dependents list
20520 -- so we can properly restore the private view on exit from the scope.
20522 declare
20523 Priv_Elmt : Elmt_Id;
20524 Priv_Scop : Entity_Id;
20525 Priv : Entity_Id;
20526 Full : Entity_Id;
20528 begin
20529 Priv_Elmt := First_Elmt (Private_Dependents (Priv_T));
20530 while Present (Priv_Elmt) loop
20531 Priv := Node (Priv_Elmt);
20532 Priv_Scop := Scope (Priv);
20534 if Ekind_In (Priv, E_Private_Subtype,
20535 E_Limited_Private_Subtype,
20536 E_Record_Subtype_With_Private)
20537 then
20538 Full := Make_Defining_Identifier (Sloc (Priv), Chars (Priv));
20539 Set_Is_Itype (Full);
20540 Set_Parent (Full, Parent (Priv));
20541 Set_Associated_Node_For_Itype (Full, N);
20543 -- Now we need to complete the private subtype, but since the
20544 -- base type has already been swapped, we must also swap the
20545 -- subtypes (and thus, reverse the arguments in the call to
20546 -- Complete_Private_Subtype). Also note that we may need to
20547 -- re-establish the scope of the private subtype.
20549 Copy_And_Swap (Priv, Full);
20551 if not In_Open_Scopes (Priv_Scop) then
20552 Push_Scope (Priv_Scop);
20554 else
20555 -- Reset Priv_Scop to Empty to indicate no scope was pushed
20557 Priv_Scop := Empty;
20558 end if;
20560 Complete_Private_Subtype (Full, Priv, Full_T, N);
20562 if Present (Priv_Scop) then
20563 Pop_Scope;
20564 end if;
20566 Replace_Elmt (Priv_Elmt, Full);
20567 end if;
20569 Next_Elmt (Priv_Elmt);
20570 end loop;
20571 end;
20573 -- If the private view was tagged, copy the new primitive operations
20574 -- from the private view to the full view.
20576 if Is_Tagged_Type (Full_T) then
20577 declare
20578 Disp_Typ : Entity_Id;
20579 Full_List : Elist_Id;
20580 Prim : Entity_Id;
20581 Prim_Elmt : Elmt_Id;
20582 Priv_List : Elist_Id;
20584 function Contains
20585 (E : Entity_Id;
20586 L : Elist_Id) return Boolean;
20587 -- Determine whether list L contains element E
20589 --------------
20590 -- Contains --
20591 --------------
20593 function Contains
20594 (E : Entity_Id;
20595 L : Elist_Id) return Boolean
20597 List_Elmt : Elmt_Id;
20599 begin
20600 List_Elmt := First_Elmt (L);
20601 while Present (List_Elmt) loop
20602 if Node (List_Elmt) = E then
20603 return True;
20604 end if;
20606 Next_Elmt (List_Elmt);
20607 end loop;
20609 return False;
20610 end Contains;
20612 -- Start of processing
20614 begin
20615 if Is_Tagged_Type (Priv_T) then
20616 Priv_List := Primitive_Operations (Priv_T);
20617 Prim_Elmt := First_Elmt (Priv_List);
20619 -- In the case of a concurrent type completing a private tagged
20620 -- type, primitives may have been declared in between the two
20621 -- views. These subprograms need to be wrapped the same way
20622 -- entries and protected procedures are handled because they
20623 -- cannot be directly shared by the two views.
20625 if Is_Concurrent_Type (Full_T) then
20626 declare
20627 Conc_Typ : constant Entity_Id :=
20628 Corresponding_Record_Type (Full_T);
20629 Curr_Nod : Node_Id := Parent (Conc_Typ);
20630 Wrap_Spec : Node_Id;
20632 begin
20633 while Present (Prim_Elmt) loop
20634 Prim := Node (Prim_Elmt);
20636 if Comes_From_Source (Prim)
20637 and then not Is_Abstract_Subprogram (Prim)
20638 then
20639 Wrap_Spec :=
20640 Make_Subprogram_Declaration (Sloc (Prim),
20641 Specification =>
20642 Build_Wrapper_Spec
20643 (Subp_Id => Prim,
20644 Obj_Typ => Conc_Typ,
20645 Formals =>
20646 Parameter_Specifications
20647 (Parent (Prim))));
20649 Insert_After (Curr_Nod, Wrap_Spec);
20650 Curr_Nod := Wrap_Spec;
20652 Analyze (Wrap_Spec);
20654 -- Remove the wrapper from visibility to avoid
20655 -- spurious conflict with the wrapped entity.
20657 Set_Is_Immediately_Visible
20658 (Defining_Entity (Specification (Wrap_Spec)),
20659 False);
20660 end if;
20662 Next_Elmt (Prim_Elmt);
20663 end loop;
20665 goto Leave;
20666 end;
20668 -- For non-concurrent types, transfer explicit primitives, but
20669 -- omit those inherited from the parent of the private view
20670 -- since they will be re-inherited later on.
20672 else
20673 Full_List := Primitive_Operations (Full_T);
20675 while Present (Prim_Elmt) loop
20676 Prim := Node (Prim_Elmt);
20678 if Comes_From_Source (Prim)
20679 and then not Contains (Prim, Full_List)
20680 then
20681 Append_Elmt (Prim, Full_List);
20682 end if;
20684 Next_Elmt (Prim_Elmt);
20685 end loop;
20686 end if;
20688 -- Untagged private view
20690 else
20691 Full_List := Primitive_Operations (Full_T);
20693 -- In this case the partial view is untagged, so here we locate
20694 -- all of the earlier primitives that need to be treated as
20695 -- dispatching (those that appear between the two views). Note
20696 -- that these additional operations must all be new operations
20697 -- (any earlier operations that override inherited operations
20698 -- of the full view will already have been inserted in the
20699 -- primitives list, marked by Check_Operation_From_Private_View
20700 -- as dispatching. Note that implicit "/=" operators are
20701 -- excluded from being added to the primitives list since they
20702 -- shouldn't be treated as dispatching (tagged "/=" is handled
20703 -- specially).
20705 Prim := Next_Entity (Full_T);
20706 while Present (Prim) and then Prim /= Priv_T loop
20707 if Ekind_In (Prim, E_Procedure, E_Function) then
20708 Disp_Typ := Find_Dispatching_Type (Prim);
20710 if Disp_Typ = Full_T
20711 and then (Chars (Prim) /= Name_Op_Ne
20712 or else Comes_From_Source (Prim))
20713 then
20714 Check_Controlling_Formals (Full_T, Prim);
20716 if not Is_Dispatching_Operation (Prim) then
20717 Append_Elmt (Prim, Full_List);
20718 Set_Is_Dispatching_Operation (Prim, True);
20719 Set_DT_Position_Value (Prim, No_Uint);
20720 end if;
20722 elsif Is_Dispatching_Operation (Prim)
20723 and then Disp_Typ /= Full_T
20724 then
20726 -- Verify that it is not otherwise controlled by a
20727 -- formal or a return value of type T.
20729 Check_Controlling_Formals (Disp_Typ, Prim);
20730 end if;
20731 end if;
20733 Next_Entity (Prim);
20734 end loop;
20735 end if;
20737 -- For the tagged case, the two views can share the same primitive
20738 -- operations list and the same class-wide type. Update attributes
20739 -- of the class-wide type which depend on the full declaration.
20741 if Is_Tagged_Type (Priv_T) then
20742 Set_Direct_Primitive_Operations (Priv_T, Full_List);
20743 Set_Class_Wide_Type
20744 (Base_Type (Full_T), Class_Wide_Type (Priv_T));
20746 Propagate_Concurrent_Flags (Class_Wide_Type (Priv_T), Full_T);
20747 end if;
20748 end;
20749 end if;
20751 -- Ada 2005 AI 161: Check preelaborable initialization consistency
20753 if Known_To_Have_Preelab_Init (Priv_T) then
20755 -- Case where there is a pragma Preelaborable_Initialization. We
20756 -- always allow this in predefined units, which is cheating a bit,
20757 -- but it means we don't have to struggle to meet the requirements in
20758 -- the RM for having Preelaborable Initialization. Otherwise we
20759 -- require that the type meets the RM rules. But we can't check that
20760 -- yet, because of the rule about overriding Initialize, so we simply
20761 -- set a flag that will be checked at freeze time.
20763 if not In_Predefined_Unit (Full_T) then
20764 Set_Must_Have_Preelab_Init (Full_T);
20765 end if;
20766 end if;
20768 -- If pragma CPP_Class was applied to the private type declaration,
20769 -- propagate it now to the full type declaration.
20771 if Is_CPP_Class (Priv_T) then
20772 Set_Is_CPP_Class (Full_T);
20773 Set_Convention (Full_T, Convention_CPP);
20775 -- Check that components of imported CPP types do not have default
20776 -- expressions.
20778 Check_CPP_Type_Has_No_Defaults (Full_T);
20779 end if;
20781 -- If the private view has user specified stream attributes, then so has
20782 -- the full view.
20784 -- Why the test, how could these flags be already set in Full_T ???
20786 if Has_Specified_Stream_Read (Priv_T) then
20787 Set_Has_Specified_Stream_Read (Full_T);
20788 end if;
20790 if Has_Specified_Stream_Write (Priv_T) then
20791 Set_Has_Specified_Stream_Write (Full_T);
20792 end if;
20794 if Has_Specified_Stream_Input (Priv_T) then
20795 Set_Has_Specified_Stream_Input (Full_T);
20796 end if;
20798 if Has_Specified_Stream_Output (Priv_T) then
20799 Set_Has_Specified_Stream_Output (Full_T);
20800 end if;
20802 -- Propagate Default_Initial_Condition-related attributes from the
20803 -- partial view to the full view and its base type.
20805 Propagate_DIC_Attributes (Full_T, From_Typ => Priv_T);
20806 Propagate_DIC_Attributes (Base_Type (Full_T), From_Typ => Priv_T);
20808 -- Propagate invariant-related attributes from the partial view to the
20809 -- full view and its base type.
20811 Propagate_Invariant_Attributes (Full_T, From_Typ => Priv_T);
20812 Propagate_Invariant_Attributes (Base_Type (Full_T), From_Typ => Priv_T);
20814 -- AI12-0041: Detect an attempt to inherit a class-wide type invariant
20815 -- in the full view without advertising the inheritance in the partial
20816 -- view. This can only occur when the partial view has no parent type
20817 -- and the full view has an interface as a parent. Any other scenarios
20818 -- are illegal because implemented interfaces must match between the
20819 -- two views.
20821 if Is_Tagged_Type (Priv_T) and then Is_Tagged_Type (Full_T) then
20822 declare
20823 Full_Par : constant Entity_Id := Etype (Full_T);
20824 Priv_Par : constant Entity_Id := Etype (Priv_T);
20826 begin
20827 if not Is_Interface (Priv_Par)
20828 and then Is_Interface (Full_Par)
20829 and then Has_Inheritable_Invariants (Full_Par)
20830 then
20831 Error_Msg_N
20832 ("hidden inheritance of class-wide type invariants not "
20833 & "allowed", N);
20834 end if;
20835 end;
20836 end if;
20838 -- Propagate predicates to full type, and predicate function if already
20839 -- defined. It is not clear that this can actually happen? the partial
20840 -- view cannot be frozen yet, and the predicate function has not been
20841 -- built. Still it is a cheap check and seems safer to make it.
20843 if Has_Predicates (Priv_T) then
20844 Set_Has_Predicates (Full_T);
20846 if Present (Predicate_Function (Priv_T)) then
20847 Set_Predicate_Function (Full_T, Predicate_Function (Priv_T));
20848 end if;
20849 end if;
20851 <<Leave>>
20852 Restore_Ghost_Mode (Saved_GM);
20853 end Process_Full_View;
20855 -----------------------------------
20856 -- Process_Incomplete_Dependents --
20857 -----------------------------------
20859 procedure Process_Incomplete_Dependents
20860 (N : Node_Id;
20861 Full_T : Entity_Id;
20862 Inc_T : Entity_Id)
20864 Inc_Elmt : Elmt_Id;
20865 Priv_Dep : Entity_Id;
20866 New_Subt : Entity_Id;
20868 Disc_Constraint : Elist_Id;
20870 begin
20871 if No (Private_Dependents (Inc_T)) then
20872 return;
20873 end if;
20875 -- Itypes that may be generated by the completion of an incomplete
20876 -- subtype are not used by the back-end and not attached to the tree.
20877 -- They are created only for constraint-checking purposes.
20879 Inc_Elmt := First_Elmt (Private_Dependents (Inc_T));
20880 while Present (Inc_Elmt) loop
20881 Priv_Dep := Node (Inc_Elmt);
20883 if Ekind (Priv_Dep) = E_Subprogram_Type then
20885 -- An Access_To_Subprogram type may have a return type or a
20886 -- parameter type that is incomplete. Replace with the full view.
20888 if Etype (Priv_Dep) = Inc_T then
20889 Set_Etype (Priv_Dep, Full_T);
20890 end if;
20892 declare
20893 Formal : Entity_Id;
20895 begin
20896 Formal := First_Formal (Priv_Dep);
20897 while Present (Formal) loop
20898 if Etype (Formal) = Inc_T then
20899 Set_Etype (Formal, Full_T);
20900 end if;
20902 Next_Formal (Formal);
20903 end loop;
20904 end;
20906 elsif Is_Overloadable (Priv_Dep) then
20908 -- If a subprogram in the incomplete dependents list is primitive
20909 -- for a tagged full type then mark it as a dispatching operation,
20910 -- check whether it overrides an inherited subprogram, and check
20911 -- restrictions on its controlling formals. Note that a protected
20912 -- operation is never dispatching: only its wrapper operation
20913 -- (which has convention Ada) is.
20915 if Is_Tagged_Type (Full_T)
20916 and then Is_Primitive (Priv_Dep)
20917 and then Convention (Priv_Dep) /= Convention_Protected
20918 then
20919 Check_Operation_From_Incomplete_Type (Priv_Dep, Inc_T);
20920 Set_Is_Dispatching_Operation (Priv_Dep);
20921 Check_Controlling_Formals (Full_T, Priv_Dep);
20922 end if;
20924 elsif Ekind (Priv_Dep) = E_Subprogram_Body then
20926 -- Can happen during processing of a body before the completion
20927 -- of a TA type. Ignore, because spec is also on dependent list.
20929 return;
20931 -- Ada 2005 (AI-412): Transform a regular incomplete subtype into a
20932 -- corresponding subtype of the full view.
20934 elsif Ekind (Priv_Dep) = E_Incomplete_Subtype
20935 and then Comes_From_Source (Priv_Dep)
20936 then
20937 Set_Subtype_Indication
20938 (Parent (Priv_Dep), New_Occurrence_Of (Full_T, Sloc (Priv_Dep)));
20939 Set_Etype (Priv_Dep, Full_T);
20940 Set_Ekind (Priv_Dep, Subtype_Kind (Ekind (Full_T)));
20941 Set_Analyzed (Parent (Priv_Dep), False);
20943 -- Reanalyze the declaration, suppressing the call to Enter_Name
20944 -- to avoid duplicate names.
20946 Analyze_Subtype_Declaration
20947 (N => Parent (Priv_Dep),
20948 Skip => True);
20950 -- Dependent is a subtype
20952 else
20953 -- We build a new subtype indication using the full view of the
20954 -- incomplete parent. The discriminant constraints have been
20955 -- elaborated already at the point of the subtype declaration.
20957 New_Subt := Create_Itype (E_Void, N);
20959 if Has_Discriminants (Full_T) then
20960 Disc_Constraint := Discriminant_Constraint (Priv_Dep);
20961 else
20962 Disc_Constraint := No_Elist;
20963 end if;
20965 Build_Discriminated_Subtype (Full_T, New_Subt, Disc_Constraint, N);
20966 Set_Full_View (Priv_Dep, New_Subt);
20967 end if;
20969 Next_Elmt (Inc_Elmt);
20970 end loop;
20971 end Process_Incomplete_Dependents;
20973 --------------------------------
20974 -- Process_Range_Expr_In_Decl --
20975 --------------------------------
20977 procedure Process_Range_Expr_In_Decl
20978 (R : Node_Id;
20979 T : Entity_Id;
20980 Subtyp : Entity_Id := Empty;
20981 Check_List : List_Id := Empty_List;
20982 R_Check_Off : Boolean := False;
20983 In_Iter_Schm : Boolean := False)
20985 Lo, Hi : Node_Id;
20986 R_Checks : Check_Result;
20987 Insert_Node : Node_Id;
20988 Def_Id : Entity_Id;
20990 begin
20991 Analyze_And_Resolve (R, Base_Type (T));
20993 if Nkind (R) = N_Range then
20995 -- In SPARK, all ranges should be static, with the exception of the
20996 -- discrete type definition of a loop parameter specification.
20998 if not In_Iter_Schm
20999 and then not Is_OK_Static_Range (R)
21000 then
21001 Check_SPARK_05_Restriction ("range should be static", R);
21002 end if;
21004 Lo := Low_Bound (R);
21005 Hi := High_Bound (R);
21007 -- Validity checks on the range of a quantified expression are
21008 -- delayed until the construct is transformed into a loop.
21010 if Nkind (Parent (R)) = N_Loop_Parameter_Specification
21011 and then Nkind (Parent (Parent (R))) = N_Quantified_Expression
21012 then
21013 null;
21015 -- We need to ensure validity of the bounds here, because if we
21016 -- go ahead and do the expansion, then the expanded code will get
21017 -- analyzed with range checks suppressed and we miss the check.
21019 -- WARNING: The capture of the range bounds with xxx_FIRST/_LAST and
21020 -- the temporaries generated by routine Remove_Side_Effects by means
21021 -- of validity checks must use the same names. When a range appears
21022 -- in the parent of a generic, the range is processed with checks
21023 -- disabled as part of the generic context and with checks enabled
21024 -- for code generation purposes. This leads to link issues as the
21025 -- generic contains references to xxx_FIRST/_LAST, but the inlined
21026 -- template sees the temporaries generated by Remove_Side_Effects.
21028 else
21029 Validity_Check_Range (R, Subtyp);
21030 end if;
21032 -- If there were errors in the declaration, try and patch up some
21033 -- common mistakes in the bounds. The cases handled are literals
21034 -- which are Integer where the expected type is Real and vice versa.
21035 -- These corrections allow the compilation process to proceed further
21036 -- along since some basic assumptions of the format of the bounds
21037 -- are guaranteed.
21039 if Etype (R) = Any_Type then
21040 if Nkind (Lo) = N_Integer_Literal and then Is_Real_Type (T) then
21041 Rewrite (Lo,
21042 Make_Real_Literal (Sloc (Lo), UR_From_Uint (Intval (Lo))));
21044 elsif Nkind (Hi) = N_Integer_Literal and then Is_Real_Type (T) then
21045 Rewrite (Hi,
21046 Make_Real_Literal (Sloc (Hi), UR_From_Uint (Intval (Hi))));
21048 elsif Nkind (Lo) = N_Real_Literal and then Is_Integer_Type (T) then
21049 Rewrite (Lo,
21050 Make_Integer_Literal (Sloc (Lo), UR_To_Uint (Realval (Lo))));
21052 elsif Nkind (Hi) = N_Real_Literal and then Is_Integer_Type (T) then
21053 Rewrite (Hi,
21054 Make_Integer_Literal (Sloc (Hi), UR_To_Uint (Realval (Hi))));
21055 end if;
21057 Set_Etype (Lo, T);
21058 Set_Etype (Hi, T);
21059 end if;
21061 -- If the bounds of the range have been mistakenly given as string
21062 -- literals (perhaps in place of character literals), then an error
21063 -- has already been reported, but we rewrite the string literal as a
21064 -- bound of the range's type to avoid blowups in later processing
21065 -- that looks at static values.
21067 if Nkind (Lo) = N_String_Literal then
21068 Rewrite (Lo,
21069 Make_Attribute_Reference (Sloc (Lo),
21070 Prefix => New_Occurrence_Of (T, Sloc (Lo)),
21071 Attribute_Name => Name_First));
21072 Analyze_And_Resolve (Lo);
21073 end if;
21075 if Nkind (Hi) = N_String_Literal then
21076 Rewrite (Hi,
21077 Make_Attribute_Reference (Sloc (Hi),
21078 Prefix => New_Occurrence_Of (T, Sloc (Hi)),
21079 Attribute_Name => Name_First));
21080 Analyze_And_Resolve (Hi);
21081 end if;
21083 -- If bounds aren't scalar at this point then exit, avoiding
21084 -- problems with further processing of the range in this procedure.
21086 if not Is_Scalar_Type (Etype (Lo)) then
21087 return;
21088 end if;
21090 -- Resolve (actually Sem_Eval) has checked that the bounds are in
21091 -- then range of the base type. Here we check whether the bounds
21092 -- are in the range of the subtype itself. Note that if the bounds
21093 -- represent the null range the Constraint_Error exception should
21094 -- not be raised.
21096 -- ??? The following code should be cleaned up as follows
21098 -- 1. The Is_Null_Range (Lo, Hi) test should disappear since it
21099 -- is done in the call to Range_Check (R, T); below
21101 -- 2. The use of R_Check_Off should be investigated and possibly
21102 -- removed, this would clean up things a bit.
21104 if Is_Null_Range (Lo, Hi) then
21105 null;
21107 else
21108 -- Capture values of bounds and generate temporaries for them
21109 -- if needed, before applying checks, since checks may cause
21110 -- duplication of the expression without forcing evaluation.
21112 -- The forced evaluation removes side effects from expressions,
21113 -- which should occur also in GNATprove mode. Otherwise, we end up
21114 -- with unexpected insertions of actions at places where this is
21115 -- not supposed to occur, e.g. on default parameters of a call.
21117 if Expander_Active or GNATprove_Mode then
21119 -- Call Force_Evaluation to create declarations as needed to
21120 -- deal with side effects, and also create typ_FIRST/LAST
21121 -- entities for bounds if we have a subtype name.
21123 -- Note: we do this transformation even if expansion is not
21124 -- active if we are in GNATprove_Mode since the transformation
21125 -- is in general required to ensure that the resulting tree has
21126 -- proper Ada semantics.
21128 Force_Evaluation
21129 (Lo, Related_Id => Subtyp, Is_Low_Bound => True);
21130 Force_Evaluation
21131 (Hi, Related_Id => Subtyp, Is_High_Bound => True);
21132 end if;
21134 -- We use a flag here instead of suppressing checks on the type
21135 -- because the type we check against isn't necessarily the place
21136 -- where we put the check.
21138 if not R_Check_Off then
21139 R_Checks := Get_Range_Checks (R, T);
21141 -- Look up tree to find an appropriate insertion point. We
21142 -- can't just use insert_actions because later processing
21143 -- depends on the insertion node. Prior to Ada 2012 the
21144 -- insertion point could only be a declaration or a loop, but
21145 -- quantified expressions can appear within any context in an
21146 -- expression, and the insertion point can be any statement,
21147 -- pragma, or declaration.
21149 Insert_Node := Parent (R);
21150 while Present (Insert_Node) loop
21151 exit when
21152 Nkind (Insert_Node) in N_Declaration
21153 and then
21154 not Nkind_In
21155 (Insert_Node, N_Component_Declaration,
21156 N_Loop_Parameter_Specification,
21157 N_Function_Specification,
21158 N_Procedure_Specification);
21160 exit when Nkind (Insert_Node) in N_Later_Decl_Item
21161 or else Nkind (Insert_Node) in
21162 N_Statement_Other_Than_Procedure_Call
21163 or else Nkind_In (Insert_Node, N_Procedure_Call_Statement,
21164 N_Pragma);
21166 Insert_Node := Parent (Insert_Node);
21167 end loop;
21169 -- Why would Type_Decl not be present??? Without this test,
21170 -- short regression tests fail.
21172 if Present (Insert_Node) then
21174 -- Case of loop statement. Verify that the range is part
21175 -- of the subtype indication of the iteration scheme.
21177 if Nkind (Insert_Node) = N_Loop_Statement then
21178 declare
21179 Indic : Node_Id;
21181 begin
21182 Indic := Parent (R);
21183 while Present (Indic)
21184 and then Nkind (Indic) /= N_Subtype_Indication
21185 loop
21186 Indic := Parent (Indic);
21187 end loop;
21189 if Present (Indic) then
21190 Def_Id := Etype (Subtype_Mark (Indic));
21192 Insert_Range_Checks
21193 (R_Checks,
21194 Insert_Node,
21195 Def_Id,
21196 Sloc (Insert_Node),
21198 Do_Before => True);
21199 end if;
21200 end;
21202 -- Insertion before a declaration. If the declaration
21203 -- includes discriminants, the list of applicable checks
21204 -- is given by the caller.
21206 elsif Nkind (Insert_Node) in N_Declaration then
21207 Def_Id := Defining_Identifier (Insert_Node);
21209 if (Ekind (Def_Id) = E_Record_Type
21210 and then Depends_On_Discriminant (R))
21211 or else
21212 (Ekind (Def_Id) = E_Protected_Type
21213 and then Has_Discriminants (Def_Id))
21214 then
21215 Append_Range_Checks
21216 (R_Checks,
21217 Check_List, Def_Id, Sloc (Insert_Node), R);
21219 else
21220 Insert_Range_Checks
21221 (R_Checks,
21222 Insert_Node, Def_Id, Sloc (Insert_Node), R);
21224 end if;
21226 -- Insertion before a statement. Range appears in the
21227 -- context of a quantified expression. Insertion will
21228 -- take place when expression is expanded.
21230 else
21231 null;
21232 end if;
21233 end if;
21234 end if;
21235 end if;
21237 -- Case of other than an explicit N_Range node
21239 -- The forced evaluation removes side effects from expressions, which
21240 -- should occur also in GNATprove mode. Otherwise, we end up with
21241 -- unexpected insertions of actions at places where this is not
21242 -- supposed to occur, e.g. on default parameters of a call.
21244 elsif Expander_Active or GNATprove_Mode then
21245 Get_Index_Bounds (R, Lo, Hi);
21246 Force_Evaluation (Lo);
21247 Force_Evaluation (Hi);
21248 end if;
21249 end Process_Range_Expr_In_Decl;
21251 --------------------------------------
21252 -- Process_Real_Range_Specification --
21253 --------------------------------------
21255 procedure Process_Real_Range_Specification (Def : Node_Id) is
21256 Spec : constant Node_Id := Real_Range_Specification (Def);
21257 Lo : Node_Id;
21258 Hi : Node_Id;
21259 Err : Boolean := False;
21261 procedure Analyze_Bound (N : Node_Id);
21262 -- Analyze and check one bound
21264 -------------------
21265 -- Analyze_Bound --
21266 -------------------
21268 procedure Analyze_Bound (N : Node_Id) is
21269 begin
21270 Analyze_And_Resolve (N, Any_Real);
21272 if not Is_OK_Static_Expression (N) then
21273 Flag_Non_Static_Expr
21274 ("bound in real type definition is not static!", N);
21275 Err := True;
21276 end if;
21277 end Analyze_Bound;
21279 -- Start of processing for Process_Real_Range_Specification
21281 begin
21282 if Present (Spec) then
21283 Lo := Low_Bound (Spec);
21284 Hi := High_Bound (Spec);
21285 Analyze_Bound (Lo);
21286 Analyze_Bound (Hi);
21288 -- If error, clear away junk range specification
21290 if Err then
21291 Set_Real_Range_Specification (Def, Empty);
21292 end if;
21293 end if;
21294 end Process_Real_Range_Specification;
21296 ---------------------
21297 -- Process_Subtype --
21298 ---------------------
21300 function Process_Subtype
21301 (S : Node_Id;
21302 Related_Nod : Node_Id;
21303 Related_Id : Entity_Id := Empty;
21304 Suffix : Character := ' ') return Entity_Id
21306 P : Node_Id;
21307 Def_Id : Entity_Id;
21308 Error_Node : Node_Id;
21309 Full_View_Id : Entity_Id;
21310 Subtype_Mark_Id : Entity_Id;
21312 May_Have_Null_Exclusion : Boolean;
21314 procedure Check_Incomplete (T : Node_Id);
21315 -- Called to verify that an incomplete type is not used prematurely
21317 ----------------------
21318 -- Check_Incomplete --
21319 ----------------------
21321 procedure Check_Incomplete (T : Node_Id) is
21322 begin
21323 -- Ada 2005 (AI-412): Incomplete subtypes are legal
21325 if Ekind (Root_Type (Entity (T))) = E_Incomplete_Type
21326 and then
21327 not (Ada_Version >= Ada_2005
21328 and then
21329 (Nkind (Parent (T)) = N_Subtype_Declaration
21330 or else (Nkind (Parent (T)) = N_Subtype_Indication
21331 and then Nkind (Parent (Parent (T))) =
21332 N_Subtype_Declaration)))
21333 then
21334 Error_Msg_N ("invalid use of type before its full declaration", T);
21335 end if;
21336 end Check_Incomplete;
21338 -- Start of processing for Process_Subtype
21340 begin
21341 -- Case of no constraints present
21343 if Nkind (S) /= N_Subtype_Indication then
21344 Find_Type (S);
21346 -- No way to proceed if the subtype indication is malformed. This
21347 -- will happen for example when the subtype indication in an object
21348 -- declaration is missing altogether and the expression is analyzed
21349 -- as if it were that indication.
21351 if not Is_Entity_Name (S) then
21352 return Any_Type;
21353 end if;
21355 Check_Incomplete (S);
21356 P := Parent (S);
21358 -- Ada 2005 (AI-231): Static check
21360 if Ada_Version >= Ada_2005
21361 and then Present (P)
21362 and then Null_Exclusion_Present (P)
21363 and then Nkind (P) /= N_Access_To_Object_Definition
21364 and then not Is_Access_Type (Entity (S))
21365 then
21366 Error_Msg_N ("`NOT NULL` only allowed for an access type", S);
21367 end if;
21369 -- The following is ugly, can't we have a range or even a flag???
21371 May_Have_Null_Exclusion :=
21372 Nkind_In (P, N_Access_Definition,
21373 N_Access_Function_Definition,
21374 N_Access_Procedure_Definition,
21375 N_Access_To_Object_Definition,
21376 N_Allocator,
21377 N_Component_Definition)
21378 or else
21379 Nkind_In (P, N_Derived_Type_Definition,
21380 N_Discriminant_Specification,
21381 N_Formal_Object_Declaration,
21382 N_Object_Declaration,
21383 N_Object_Renaming_Declaration,
21384 N_Parameter_Specification,
21385 N_Subtype_Declaration);
21387 -- Create an Itype that is a duplicate of Entity (S) but with the
21388 -- null-exclusion attribute.
21390 if May_Have_Null_Exclusion
21391 and then Is_Access_Type (Entity (S))
21392 and then Null_Exclusion_Present (P)
21394 -- No need to check the case of an access to object definition.
21395 -- It is correct to define double not-null pointers.
21397 -- Example:
21398 -- type Not_Null_Int_Ptr is not null access Integer;
21399 -- type Acc is not null access Not_Null_Int_Ptr;
21401 and then Nkind (P) /= N_Access_To_Object_Definition
21402 then
21403 if Can_Never_Be_Null (Entity (S)) then
21404 case Nkind (Related_Nod) is
21405 when N_Full_Type_Declaration =>
21406 if Nkind (Type_Definition (Related_Nod))
21407 in N_Array_Type_Definition
21408 then
21409 Error_Node :=
21410 Subtype_Indication
21411 (Component_Definition
21412 (Type_Definition (Related_Nod)));
21413 else
21414 Error_Node :=
21415 Subtype_Indication (Type_Definition (Related_Nod));
21416 end if;
21418 when N_Subtype_Declaration =>
21419 Error_Node := Subtype_Indication (Related_Nod);
21421 when N_Object_Declaration =>
21422 Error_Node := Object_Definition (Related_Nod);
21424 when N_Component_Declaration =>
21425 Error_Node :=
21426 Subtype_Indication (Component_Definition (Related_Nod));
21428 when N_Allocator =>
21429 Error_Node := Expression (Related_Nod);
21431 when others =>
21432 pragma Assert (False);
21433 Error_Node := Related_Nod;
21434 end case;
21436 Error_Msg_NE
21437 ("`NOT NULL` not allowed (& already excludes null)",
21438 Error_Node,
21439 Entity (S));
21440 end if;
21442 Set_Etype (S,
21443 Create_Null_Excluding_Itype
21444 (T => Entity (S),
21445 Related_Nod => P));
21446 Set_Entity (S, Etype (S));
21447 end if;
21449 return Entity (S);
21451 -- Case of constraint present, so that we have an N_Subtype_Indication
21452 -- node (this node is created only if constraints are present).
21454 else
21455 Find_Type (Subtype_Mark (S));
21457 if Nkind (Parent (S)) /= N_Access_To_Object_Definition
21458 and then not
21459 (Nkind (Parent (S)) = N_Subtype_Declaration
21460 and then Is_Itype (Defining_Identifier (Parent (S))))
21461 then
21462 Check_Incomplete (Subtype_Mark (S));
21463 end if;
21465 P := Parent (S);
21466 Subtype_Mark_Id := Entity (Subtype_Mark (S));
21468 -- Explicit subtype declaration case
21470 if Nkind (P) = N_Subtype_Declaration then
21471 Def_Id := Defining_Identifier (P);
21473 -- Explicit derived type definition case
21475 elsif Nkind (P) = N_Derived_Type_Definition then
21476 Def_Id := Defining_Identifier (Parent (P));
21478 -- Implicit case, the Def_Id must be created as an implicit type.
21479 -- The one exception arises in the case of concurrent types, array
21480 -- and access types, where other subsidiary implicit types may be
21481 -- created and must appear before the main implicit type. In these
21482 -- cases we leave Def_Id set to Empty as a signal that Create_Itype
21483 -- has not yet been called to create Def_Id.
21485 else
21486 if Is_Array_Type (Subtype_Mark_Id)
21487 or else Is_Concurrent_Type (Subtype_Mark_Id)
21488 or else Is_Access_Type (Subtype_Mark_Id)
21489 then
21490 Def_Id := Empty;
21492 -- For the other cases, we create a new unattached Itype,
21493 -- and set the indication to ensure it gets attached later.
21495 else
21496 Def_Id :=
21497 Create_Itype (E_Void, Related_Nod, Related_Id, Suffix);
21498 end if;
21499 end if;
21501 -- If the kind of constraint is invalid for this kind of type,
21502 -- then give an error, and then pretend no constraint was given.
21504 if not Is_Valid_Constraint_Kind
21505 (Ekind (Subtype_Mark_Id), Nkind (Constraint (S)))
21506 then
21507 Error_Msg_N
21508 ("incorrect constraint for this kind of type", Constraint (S));
21510 Rewrite (S, New_Copy_Tree (Subtype_Mark (S)));
21512 -- Set Ekind of orphan itype, to prevent cascaded errors
21514 if Present (Def_Id) then
21515 Set_Ekind (Def_Id, Ekind (Any_Type));
21516 end if;
21518 -- Make recursive call, having got rid of the bogus constraint
21520 return Process_Subtype (S, Related_Nod, Related_Id, Suffix);
21521 end if;
21523 -- Remaining processing depends on type. Select on Base_Type kind to
21524 -- ensure getting to the concrete type kind in the case of a private
21525 -- subtype (needed when only doing semantic analysis).
21527 case Ekind (Base_Type (Subtype_Mark_Id)) is
21528 when Access_Kind =>
21530 -- If this is a constraint on a class-wide type, discard it.
21531 -- There is currently no way to express a partial discriminant
21532 -- constraint on a type with unknown discriminants. This is
21533 -- a pathology that the ACATS wisely decides not to test.
21535 if Is_Class_Wide_Type (Designated_Type (Subtype_Mark_Id)) then
21536 if Comes_From_Source (S) then
21537 Error_Msg_N
21538 ("constraint on class-wide type ignored??",
21539 Constraint (S));
21540 end if;
21542 if Nkind (P) = N_Subtype_Declaration then
21543 Set_Subtype_Indication (P,
21544 New_Occurrence_Of (Subtype_Mark_Id, Sloc (S)));
21545 end if;
21547 return Subtype_Mark_Id;
21548 end if;
21550 Constrain_Access (Def_Id, S, Related_Nod);
21552 if Expander_Active
21553 and then Is_Itype (Designated_Type (Def_Id))
21554 and then Nkind (Related_Nod) = N_Subtype_Declaration
21555 and then not Is_Incomplete_Type (Designated_Type (Def_Id))
21556 then
21557 Build_Itype_Reference
21558 (Designated_Type (Def_Id), Related_Nod);
21559 end if;
21561 when Array_Kind =>
21562 Constrain_Array (Def_Id, S, Related_Nod, Related_Id, Suffix);
21564 when Decimal_Fixed_Point_Kind =>
21565 Constrain_Decimal (Def_Id, S);
21567 when Enumeration_Kind =>
21568 Constrain_Enumeration (Def_Id, S);
21569 Inherit_Predicate_Flags (Def_Id, Subtype_Mark_Id);
21571 when Ordinary_Fixed_Point_Kind =>
21572 Constrain_Ordinary_Fixed (Def_Id, S);
21574 when Float_Kind =>
21575 Constrain_Float (Def_Id, S);
21577 when Integer_Kind =>
21578 Constrain_Integer (Def_Id, S);
21579 Inherit_Predicate_Flags (Def_Id, Subtype_Mark_Id);
21581 when Class_Wide_Kind
21582 | E_Incomplete_Type
21583 | E_Record_Subtype
21584 | E_Record_Type
21586 Constrain_Discriminated_Type (Def_Id, S, Related_Nod);
21588 if Ekind (Def_Id) = E_Incomplete_Type then
21589 Set_Private_Dependents (Def_Id, New_Elmt_List);
21590 end if;
21592 when Private_Kind =>
21593 Constrain_Discriminated_Type (Def_Id, S, Related_Nod);
21595 -- The base type may be private but Def_Id may be a full view
21596 -- in an instance.
21598 if Is_Private_Type (Def_Id) then
21599 Set_Private_Dependents (Def_Id, New_Elmt_List);
21600 end if;
21602 -- In case of an invalid constraint prevent further processing
21603 -- since the type constructed is missing expected fields.
21605 if Etype (Def_Id) = Any_Type then
21606 return Def_Id;
21607 end if;
21609 -- If the full view is that of a task with discriminants,
21610 -- we must constrain both the concurrent type and its
21611 -- corresponding record type. Otherwise we will just propagate
21612 -- the constraint to the full view, if available.
21614 if Present (Full_View (Subtype_Mark_Id))
21615 and then Has_Discriminants (Subtype_Mark_Id)
21616 and then Is_Concurrent_Type (Full_View (Subtype_Mark_Id))
21617 then
21618 Full_View_Id :=
21619 Create_Itype (E_Void, Related_Nod, Related_Id, Suffix);
21621 Set_Entity (Subtype_Mark (S), Full_View (Subtype_Mark_Id));
21622 Constrain_Concurrent (Full_View_Id, S,
21623 Related_Nod, Related_Id, Suffix);
21624 Set_Entity (Subtype_Mark (S), Subtype_Mark_Id);
21625 Set_Full_View (Def_Id, Full_View_Id);
21627 -- Introduce an explicit reference to the private subtype,
21628 -- to prevent scope anomalies in gigi if first use appears
21629 -- in a nested context, e.g. a later function body.
21630 -- Should this be generated in other contexts than a full
21631 -- type declaration?
21633 if Is_Itype (Def_Id)
21634 and then
21635 Nkind (Parent (P)) = N_Full_Type_Declaration
21636 then
21637 Build_Itype_Reference (Def_Id, Parent (P));
21638 end if;
21640 else
21641 Prepare_Private_Subtype_Completion (Def_Id, Related_Nod);
21642 end if;
21644 when Concurrent_Kind =>
21645 Constrain_Concurrent (Def_Id, S,
21646 Related_Nod, Related_Id, Suffix);
21648 when others =>
21649 Error_Msg_N ("invalid subtype mark in subtype indication", S);
21650 end case;
21652 -- Size, Alignment, Representation aspects and Convention are always
21653 -- inherited from the base type.
21655 Set_Size_Info (Def_Id, (Subtype_Mark_Id));
21656 Set_Rep_Info (Def_Id, (Subtype_Mark_Id));
21657 Set_Convention (Def_Id, Convention (Subtype_Mark_Id));
21659 return Def_Id;
21660 end if;
21661 end Process_Subtype;
21663 -----------------------------
21664 -- Record_Type_Declaration --
21665 -----------------------------
21667 procedure Record_Type_Declaration
21668 (T : Entity_Id;
21669 N : Node_Id;
21670 Prev : Entity_Id)
21672 Def : constant Node_Id := Type_Definition (N);
21673 Is_Tagged : Boolean;
21674 Tag_Comp : Entity_Id;
21676 begin
21677 -- These flags must be initialized before calling Process_Discriminants
21678 -- because this routine makes use of them.
21680 Set_Ekind (T, E_Record_Type);
21681 Set_Etype (T, T);
21682 Init_Size_Align (T);
21683 Set_Interfaces (T, No_Elist);
21684 Set_Stored_Constraint (T, No_Elist);
21685 Set_Default_SSO (T);
21686 Set_No_Reordering (T, No_Component_Reordering);
21688 -- Normal case
21690 if Ada_Version < Ada_2005 or else not Interface_Present (Def) then
21691 if Limited_Present (Def) then
21692 Check_SPARK_05_Restriction ("limited is not allowed", N);
21693 end if;
21695 if Abstract_Present (Def) then
21696 Check_SPARK_05_Restriction ("abstract is not allowed", N);
21697 end if;
21699 -- The flag Is_Tagged_Type might have already been set by
21700 -- Find_Type_Name if it detected an error for declaration T. This
21701 -- arises in the case of private tagged types where the full view
21702 -- omits the word tagged.
21704 Is_Tagged :=
21705 Tagged_Present (Def)
21706 or else (Serious_Errors_Detected > 0 and then Is_Tagged_Type (T));
21708 Set_Is_Limited_Record (T, Limited_Present (Def));
21710 if Is_Tagged then
21711 Set_Is_Tagged_Type (T, True);
21712 Set_No_Tagged_Streams_Pragma (T, No_Tagged_Streams);
21713 end if;
21715 -- Type is abstract if full declaration carries keyword, or if
21716 -- previous partial view did.
21718 Set_Is_Abstract_Type (T, Is_Abstract_Type (T)
21719 or else Abstract_Present (Def));
21721 else
21722 Check_SPARK_05_Restriction ("interface is not allowed", N);
21724 Is_Tagged := True;
21725 Analyze_Interface_Declaration (T, Def);
21727 if Present (Discriminant_Specifications (N)) then
21728 Error_Msg_N
21729 ("interface types cannot have discriminants",
21730 Defining_Identifier
21731 (First (Discriminant_Specifications (N))));
21732 end if;
21733 end if;
21735 -- First pass: if there are self-referential access components,
21736 -- create the required anonymous access type declarations, and if
21737 -- need be an incomplete type declaration for T itself.
21739 Check_Anonymous_Access_Components (N, T, Prev, Component_List (Def));
21741 if Ada_Version >= Ada_2005
21742 and then Present (Interface_List (Def))
21743 then
21744 Check_Interfaces (N, Def);
21746 declare
21747 Ifaces_List : Elist_Id;
21749 begin
21750 -- Ada 2005 (AI-251): Collect the list of progenitors that are not
21751 -- already in the parents.
21753 Collect_Interfaces
21754 (T => T,
21755 Ifaces_List => Ifaces_List,
21756 Exclude_Parents => True);
21758 Set_Interfaces (T, Ifaces_List);
21759 end;
21760 end if;
21762 -- Records constitute a scope for the component declarations within.
21763 -- The scope is created prior to the processing of these declarations.
21764 -- Discriminants are processed first, so that they are visible when
21765 -- processing the other components. The Ekind of the record type itself
21766 -- is set to E_Record_Type (subtypes appear as E_Record_Subtype).
21768 -- Enter record scope
21770 Push_Scope (T);
21772 -- If an incomplete or private type declaration was already given for
21773 -- the type, then this scope already exists, and the discriminants have
21774 -- been declared within. We must verify that the full declaration
21775 -- matches the incomplete one.
21777 Check_Or_Process_Discriminants (N, T, Prev);
21779 Set_Is_Constrained (T, not Has_Discriminants (T));
21780 Set_Has_Delayed_Freeze (T, True);
21782 -- For tagged types add a manually analyzed component corresponding
21783 -- to the component _tag, the corresponding piece of tree will be
21784 -- expanded as part of the freezing actions if it is not a CPP_Class.
21786 if Is_Tagged then
21788 -- Do not add the tag unless we are in expansion mode
21790 if Expander_Active then
21791 Tag_Comp := Make_Defining_Identifier (Sloc (Def), Name_uTag);
21792 Enter_Name (Tag_Comp);
21794 Set_Ekind (Tag_Comp, E_Component);
21795 Set_Is_Tag (Tag_Comp);
21796 Set_Is_Aliased (Tag_Comp);
21797 Set_Etype (Tag_Comp, RTE (RE_Tag));
21798 Set_DT_Entry_Count (Tag_Comp, No_Uint);
21799 Set_Original_Record_Component (Tag_Comp, Tag_Comp);
21800 Init_Component_Location (Tag_Comp);
21802 -- Ada 2005 (AI-251): Addition of the Tag corresponding to all the
21803 -- implemented interfaces.
21805 if Has_Interfaces (T) then
21806 Add_Interface_Tag_Components (N, T);
21807 end if;
21808 end if;
21810 Make_Class_Wide_Type (T);
21811 Set_Direct_Primitive_Operations (T, New_Elmt_List);
21812 end if;
21814 -- We must suppress range checks when processing record components in
21815 -- the presence of discriminants, since we don't want spurious checks to
21816 -- be generated during their analysis, but Suppress_Range_Checks flags
21817 -- must be reset the after processing the record definition.
21819 -- Note: this is the only use of Kill_Range_Checks, and is a bit odd,
21820 -- couldn't we just use the normal range check suppression method here.
21821 -- That would seem cleaner ???
21823 if Has_Discriminants (T) and then not Range_Checks_Suppressed (T) then
21824 Set_Kill_Range_Checks (T, True);
21825 Record_Type_Definition (Def, Prev);
21826 Set_Kill_Range_Checks (T, False);
21827 else
21828 Record_Type_Definition (Def, Prev);
21829 end if;
21831 -- Exit from record scope
21833 End_Scope;
21835 -- Ada 2005 (AI-251 and AI-345): Derive the interface subprograms of all
21836 -- the implemented interfaces and associate them an aliased entity.
21838 if Is_Tagged
21839 and then not Is_Empty_List (Interface_List (Def))
21840 then
21841 Derive_Progenitor_Subprograms (T, T);
21842 end if;
21844 Check_Function_Writable_Actuals (N);
21845 end Record_Type_Declaration;
21847 ----------------------------
21848 -- Record_Type_Definition --
21849 ----------------------------
21851 procedure Record_Type_Definition (Def : Node_Id; Prev_T : Entity_Id) is
21852 Component : Entity_Id;
21853 Ctrl_Components : Boolean := False;
21854 Final_Storage_Only : Boolean;
21855 T : Entity_Id;
21857 begin
21858 if Ekind (Prev_T) = E_Incomplete_Type then
21859 T := Full_View (Prev_T);
21860 else
21861 T := Prev_T;
21862 end if;
21864 -- In SPARK, tagged types and type extensions may only be declared in
21865 -- the specification of library unit packages.
21867 if Present (Def) and then Is_Tagged_Type (T) then
21868 declare
21869 Typ : Node_Id;
21870 Ctxt : Node_Id;
21872 begin
21873 if Nkind (Parent (Def)) = N_Full_Type_Declaration then
21874 Typ := Parent (Def);
21875 else
21876 pragma Assert
21877 (Nkind (Parent (Def)) = N_Derived_Type_Definition);
21878 Typ := Parent (Parent (Def));
21879 end if;
21881 Ctxt := Parent (Typ);
21883 if Nkind (Ctxt) = N_Package_Body
21884 and then Nkind (Parent (Ctxt)) = N_Compilation_Unit
21885 then
21886 Check_SPARK_05_Restriction
21887 ("type should be defined in package specification", Typ);
21889 elsif Nkind (Ctxt) /= N_Package_Specification
21890 or else Nkind (Parent (Parent (Ctxt))) /= N_Compilation_Unit
21891 then
21892 Check_SPARK_05_Restriction
21893 ("type should be defined in library unit package", Typ);
21894 end if;
21895 end;
21896 end if;
21898 Final_Storage_Only := not Is_Controlled (T);
21900 -- Ada 2005: Check whether an explicit Limited is present in a derived
21901 -- type declaration.
21903 if Nkind (Parent (Def)) = N_Derived_Type_Definition
21904 and then Limited_Present (Parent (Def))
21905 then
21906 Set_Is_Limited_Record (T);
21907 end if;
21909 -- If the component list of a record type is defined by the reserved
21910 -- word null and there is no discriminant part, then the record type has
21911 -- no components and all records of the type are null records (RM 3.7)
21912 -- This procedure is also called to process the extension part of a
21913 -- record extension, in which case the current scope may have inherited
21914 -- components.
21916 if No (Def)
21917 or else No (Component_List (Def))
21918 or else Null_Present (Component_List (Def))
21919 then
21920 if not Is_Tagged_Type (T) then
21921 Check_SPARK_05_Restriction ("untagged record cannot be null", Def);
21922 end if;
21924 else
21925 Analyze_Declarations (Component_Items (Component_List (Def)));
21927 if Present (Variant_Part (Component_List (Def))) then
21928 Check_SPARK_05_Restriction ("variant part is not allowed", Def);
21929 Analyze (Variant_Part (Component_List (Def)));
21930 end if;
21931 end if;
21933 -- After completing the semantic analysis of the record definition,
21934 -- record components, both new and inherited, are accessible. Set their
21935 -- kind accordingly. Exclude malformed itypes from illegal declarations,
21936 -- whose Ekind may be void.
21938 Component := First_Entity (Current_Scope);
21939 while Present (Component) loop
21940 if Ekind (Component) = E_Void
21941 and then not Is_Itype (Component)
21942 then
21943 Set_Ekind (Component, E_Component);
21944 Init_Component_Location (Component);
21945 end if;
21947 Propagate_Concurrent_Flags (T, Etype (Component));
21949 if Ekind (Component) /= E_Component then
21950 null;
21952 -- Do not set Has_Controlled_Component on a class-wide equivalent
21953 -- type. See Make_CW_Equivalent_Type.
21955 elsif not Is_Class_Wide_Equivalent_Type (T)
21956 and then (Has_Controlled_Component (Etype (Component))
21957 or else (Chars (Component) /= Name_uParent
21958 and then Is_Controlled (Etype (Component))))
21959 then
21960 Set_Has_Controlled_Component (T, True);
21961 Final_Storage_Only :=
21962 Final_Storage_Only
21963 and then Finalize_Storage_Only (Etype (Component));
21964 Ctrl_Components := True;
21965 end if;
21967 Next_Entity (Component);
21968 end loop;
21970 -- A Type is Finalize_Storage_Only only if all its controlled components
21971 -- are also.
21973 if Ctrl_Components then
21974 Set_Finalize_Storage_Only (T, Final_Storage_Only);
21975 end if;
21977 -- Place reference to end record on the proper entity, which may
21978 -- be a partial view.
21980 if Present (Def) then
21981 Process_End_Label (Def, 'e', Prev_T);
21982 end if;
21983 end Record_Type_Definition;
21985 ------------------------
21986 -- Replace_Components --
21987 ------------------------
21989 procedure Replace_Components (Typ : Entity_Id; Decl : Node_Id) is
21990 function Process (N : Node_Id) return Traverse_Result;
21992 -------------
21993 -- Process --
21994 -------------
21996 function Process (N : Node_Id) return Traverse_Result is
21997 Comp : Entity_Id;
21999 begin
22000 if Nkind (N) = N_Discriminant_Specification then
22001 Comp := First_Discriminant (Typ);
22002 while Present (Comp) loop
22003 if Chars (Comp) = Chars (Defining_Identifier (N)) then
22004 Set_Defining_Identifier (N, Comp);
22005 exit;
22006 end if;
22008 Next_Discriminant (Comp);
22009 end loop;
22011 elsif Nkind (N) = N_Variant_Part then
22012 Comp := First_Discriminant (Typ);
22013 while Present (Comp) loop
22014 if Chars (Comp) = Chars (Name (N)) then
22015 Set_Entity (Name (N), Comp);
22016 exit;
22017 end if;
22019 Next_Discriminant (Comp);
22020 end loop;
22022 elsif Nkind (N) = N_Component_Declaration then
22023 Comp := First_Component (Typ);
22024 while Present (Comp) loop
22025 if Chars (Comp) = Chars (Defining_Identifier (N)) then
22026 Set_Defining_Identifier (N, Comp);
22027 exit;
22028 end if;
22030 Next_Component (Comp);
22031 end loop;
22032 end if;
22034 return OK;
22035 end Process;
22037 procedure Replace is new Traverse_Proc (Process);
22039 -- Start of processing for Replace_Components
22041 begin
22042 Replace (Decl);
22043 end Replace_Components;
22045 -------------------------------
22046 -- Set_Completion_Referenced --
22047 -------------------------------
22049 procedure Set_Completion_Referenced (E : Entity_Id) is
22050 begin
22051 -- If in main unit, mark entity that is a completion as referenced,
22052 -- warnings go on the partial view when needed.
22054 if In_Extended_Main_Source_Unit (E) then
22055 Set_Referenced (E);
22056 end if;
22057 end Set_Completion_Referenced;
22059 ---------------------
22060 -- Set_Default_SSO --
22061 ---------------------
22063 procedure Set_Default_SSO (T : Entity_Id) is
22064 begin
22065 case Opt.Default_SSO is
22066 when ' ' =>
22067 null;
22068 when 'L' =>
22069 Set_SSO_Set_Low_By_Default (T, True);
22070 when 'H' =>
22071 Set_SSO_Set_High_By_Default (T, True);
22072 when others =>
22073 raise Program_Error;
22074 end case;
22075 end Set_Default_SSO;
22077 ---------------------
22078 -- Set_Fixed_Range --
22079 ---------------------
22081 -- The range for fixed-point types is complicated by the fact that we
22082 -- do not know the exact end points at the time of the declaration. This
22083 -- is true for three reasons:
22085 -- A size clause may affect the fudging of the end-points.
22086 -- A small clause may affect the values of the end-points.
22087 -- We try to include the end-points if it does not affect the size.
22089 -- This means that the actual end-points must be established at the
22090 -- point when the type is frozen. Meanwhile, we first narrow the range
22091 -- as permitted (so that it will fit if necessary in a small specified
22092 -- size), and then build a range subtree with these narrowed bounds.
22093 -- Set_Fixed_Range constructs the range from real literal values, and
22094 -- sets the range as the Scalar_Range of the given fixed-point type entity.
22096 -- The parent of this range is set to point to the entity so that it is
22097 -- properly hooked into the tree (unlike normal Scalar_Range entries for
22098 -- other scalar types, which are just pointers to the range in the
22099 -- original tree, this would otherwise be an orphan).
22101 -- The tree is left unanalyzed. When the type is frozen, the processing
22102 -- in Freeze.Freeze_Fixed_Point_Type notices that the range is not
22103 -- analyzed, and uses this as an indication that it should complete
22104 -- work on the range (it will know the final small and size values).
22106 procedure Set_Fixed_Range
22107 (E : Entity_Id;
22108 Loc : Source_Ptr;
22109 Lo : Ureal;
22110 Hi : Ureal)
22112 S : constant Node_Id :=
22113 Make_Range (Loc,
22114 Low_Bound => Make_Real_Literal (Loc, Lo),
22115 High_Bound => Make_Real_Literal (Loc, Hi));
22116 begin
22117 Set_Scalar_Range (E, S);
22118 Set_Parent (S, E);
22120 -- Before the freeze point, the bounds of a fixed point are universal
22121 -- and carry the corresponding type.
22123 Set_Etype (Low_Bound (S), Universal_Real);
22124 Set_Etype (High_Bound (S), Universal_Real);
22125 end Set_Fixed_Range;
22127 ----------------------------------
22128 -- Set_Scalar_Range_For_Subtype --
22129 ----------------------------------
22131 procedure Set_Scalar_Range_For_Subtype
22132 (Def_Id : Entity_Id;
22133 R : Node_Id;
22134 Subt : Entity_Id)
22136 Kind : constant Entity_Kind := Ekind (Def_Id);
22138 begin
22139 -- Defend against previous error
22141 if Nkind (R) = N_Error then
22142 return;
22143 end if;
22145 Set_Scalar_Range (Def_Id, R);
22147 -- We need to link the range into the tree before resolving it so
22148 -- that types that are referenced, including importantly the subtype
22149 -- itself, are properly frozen (Freeze_Expression requires that the
22150 -- expression be properly linked into the tree). Of course if it is
22151 -- already linked in, then we do not disturb the current link.
22153 if No (Parent (R)) then
22154 Set_Parent (R, Def_Id);
22155 end if;
22157 -- Reset the kind of the subtype during analysis of the range, to
22158 -- catch possible premature use in the bounds themselves.
22160 Set_Ekind (Def_Id, E_Void);
22161 Process_Range_Expr_In_Decl (R, Subt, Subtyp => Def_Id);
22162 Set_Ekind (Def_Id, Kind);
22163 end Set_Scalar_Range_For_Subtype;
22165 --------------------------------------------------------
22166 -- Set_Stored_Constraint_From_Discriminant_Constraint --
22167 --------------------------------------------------------
22169 procedure Set_Stored_Constraint_From_Discriminant_Constraint
22170 (E : Entity_Id)
22172 begin
22173 -- Make sure set if encountered during Expand_To_Stored_Constraint
22175 Set_Stored_Constraint (E, No_Elist);
22177 -- Give it the right value
22179 if Is_Constrained (E) and then Has_Discriminants (E) then
22180 Set_Stored_Constraint (E,
22181 Expand_To_Stored_Constraint (E, Discriminant_Constraint (E)));
22182 end if;
22183 end Set_Stored_Constraint_From_Discriminant_Constraint;
22185 -------------------------------------
22186 -- Signed_Integer_Type_Declaration --
22187 -------------------------------------
22189 procedure Signed_Integer_Type_Declaration (T : Entity_Id; Def : Node_Id) is
22190 Implicit_Base : Entity_Id;
22191 Base_Typ : Entity_Id;
22192 Lo_Val : Uint;
22193 Hi_Val : Uint;
22194 Errs : Boolean := False;
22195 Lo : Node_Id;
22196 Hi : Node_Id;
22198 function Can_Derive_From (E : Entity_Id) return Boolean;
22199 -- Determine whether given bounds allow derivation from specified type
22201 procedure Check_Bound (Expr : Node_Id);
22202 -- Check bound to make sure it is integral and static. If not, post
22203 -- appropriate error message and set Errs flag
22205 ---------------------
22206 -- Can_Derive_From --
22207 ---------------------
22209 -- Note we check both bounds against both end values, to deal with
22210 -- strange types like ones with a range of 0 .. -12341234.
22212 function Can_Derive_From (E : Entity_Id) return Boolean is
22213 Lo : constant Uint := Expr_Value (Type_Low_Bound (E));
22214 Hi : constant Uint := Expr_Value (Type_High_Bound (E));
22215 begin
22216 return Lo <= Lo_Val and then Lo_Val <= Hi
22217 and then
22218 Lo <= Hi_Val and then Hi_Val <= Hi;
22219 end Can_Derive_From;
22221 -----------------
22222 -- Check_Bound --
22223 -----------------
22225 procedure Check_Bound (Expr : Node_Id) is
22226 begin
22227 -- If a range constraint is used as an integer type definition, each
22228 -- bound of the range must be defined by a static expression of some
22229 -- integer type, but the two bounds need not have the same integer
22230 -- type (Negative bounds are allowed.) (RM 3.5.4)
22232 if not Is_Integer_Type (Etype (Expr)) then
22233 Error_Msg_N
22234 ("integer type definition bounds must be of integer type", Expr);
22235 Errs := True;
22237 elsif not Is_OK_Static_Expression (Expr) then
22238 Flag_Non_Static_Expr
22239 ("non-static expression used for integer type bound!", Expr);
22240 Errs := True;
22242 -- The bounds are folded into literals, and we set their type to be
22243 -- universal, to avoid typing difficulties: we cannot set the type
22244 -- of the literal to the new type, because this would be a forward
22245 -- reference for the back end, and if the original type is user-
22246 -- defined this can lead to spurious semantic errors (e.g. 2928-003).
22248 else
22249 if Is_Entity_Name (Expr) then
22250 Fold_Uint (Expr, Expr_Value (Expr), True);
22251 end if;
22253 Set_Etype (Expr, Universal_Integer);
22254 end if;
22255 end Check_Bound;
22257 -- Start of processing for Signed_Integer_Type_Declaration
22259 begin
22260 -- Create an anonymous base type
22262 Implicit_Base :=
22263 Create_Itype (E_Signed_Integer_Type, Parent (Def), T, 'B');
22265 -- Analyze and check the bounds, they can be of any integer type
22267 Lo := Low_Bound (Def);
22268 Hi := High_Bound (Def);
22270 -- Arbitrarily use Integer as the type if either bound had an error
22272 if Hi = Error or else Lo = Error then
22273 Base_Typ := Any_Integer;
22274 Set_Error_Posted (T, True);
22276 -- Here both bounds are OK expressions
22278 else
22279 Analyze_And_Resolve (Lo, Any_Integer);
22280 Analyze_And_Resolve (Hi, Any_Integer);
22282 Check_Bound (Lo);
22283 Check_Bound (Hi);
22285 if Errs then
22286 Hi := Type_High_Bound (Standard_Long_Long_Integer);
22287 Lo := Type_Low_Bound (Standard_Long_Long_Integer);
22288 end if;
22290 -- Find type to derive from
22292 Lo_Val := Expr_Value (Lo);
22293 Hi_Val := Expr_Value (Hi);
22295 if Can_Derive_From (Standard_Short_Short_Integer) then
22296 Base_Typ := Base_Type (Standard_Short_Short_Integer);
22298 elsif Can_Derive_From (Standard_Short_Integer) then
22299 Base_Typ := Base_Type (Standard_Short_Integer);
22301 elsif Can_Derive_From (Standard_Integer) then
22302 Base_Typ := Base_Type (Standard_Integer);
22304 elsif Can_Derive_From (Standard_Long_Integer) then
22305 Base_Typ := Base_Type (Standard_Long_Integer);
22307 elsif Can_Derive_From (Standard_Long_Long_Integer) then
22308 Check_Restriction (No_Long_Long_Integers, Def);
22309 Base_Typ := Base_Type (Standard_Long_Long_Integer);
22311 else
22312 Base_Typ := Base_Type (Standard_Long_Long_Integer);
22313 Error_Msg_N ("integer type definition bounds out of range", Def);
22314 Hi := Type_High_Bound (Standard_Long_Long_Integer);
22315 Lo := Type_Low_Bound (Standard_Long_Long_Integer);
22316 end if;
22317 end if;
22319 -- Complete both implicit base and declared first subtype entities. The
22320 -- inheritance of the rep item chain ensures that SPARK-related pragmas
22321 -- are not clobbered when the signed integer type acts as a full view of
22322 -- a private type.
22324 Set_Etype (Implicit_Base, Base_Typ);
22325 Set_Size_Info (Implicit_Base, Base_Typ);
22326 Set_RM_Size (Implicit_Base, RM_Size (Base_Typ));
22327 Set_First_Rep_Item (Implicit_Base, First_Rep_Item (Base_Typ));
22328 Set_Scalar_Range (Implicit_Base, Scalar_Range (Base_Typ));
22330 Set_Ekind (T, E_Signed_Integer_Subtype);
22331 Set_Etype (T, Implicit_Base);
22332 Set_Size_Info (T, Implicit_Base);
22333 Inherit_Rep_Item_Chain (T, Implicit_Base);
22334 Set_Scalar_Range (T, Def);
22335 Set_RM_Size (T, UI_From_Int (Minimum_Size (T)));
22336 Set_Is_Constrained (T);
22337 end Signed_Integer_Type_Declaration;
22339 end Sem_Ch3;