2014-12-12 Richard Biener <rguenther@suse.de>
[official-gcc.git] / gcc / ada / sem_res.adb
blob8b0f6585f882bdc80207e0758a25068a7bb8a396
1 ------------------------------------------------------------------------------
2 -- --
3 -- GNAT COMPILER COMPONENTS --
4 -- --
5 -- S E M _ R E S --
6 -- --
7 -- B o d y --
8 -- --
9 -- Copyright (C) 1992-2014, 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 Atree; use Atree;
27 with Checks; use Checks;
28 with Debug; use Debug;
29 with Debug_A; use Debug_A;
30 with Einfo; use Einfo;
31 with Errout; use Errout;
32 with Expander; use Expander;
33 with Exp_Disp; use Exp_Disp;
34 with Exp_Ch6; use Exp_Ch6;
35 with Exp_Ch7; use Exp_Ch7;
36 with Exp_Tss; use Exp_Tss;
37 with Exp_Util; use Exp_Util;
38 with Fname; use Fname;
39 with Freeze; use Freeze;
40 with Inline; use Inline;
41 with Itypes; use Itypes;
42 with Lib; use Lib;
43 with Lib.Xref; use Lib.Xref;
44 with Namet; use Namet;
45 with Nmake; use Nmake;
46 with Nlists; use Nlists;
47 with Opt; use Opt;
48 with Output; use Output;
49 with Restrict; use Restrict;
50 with Rident; use Rident;
51 with Rtsfind; use Rtsfind;
52 with Sem; use Sem;
53 with Sem_Aux; use Sem_Aux;
54 with Sem_Aggr; use Sem_Aggr;
55 with Sem_Attr; use Sem_Attr;
56 with Sem_Cat; use Sem_Cat;
57 with Sem_Ch4; use Sem_Ch4;
58 with Sem_Ch6; use Sem_Ch6;
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_Elim; use Sem_Elim;
65 with Sem_Elab; use Sem_Elab;
66 with Sem_Eval; use Sem_Eval;
67 with Sem_Intr; use Sem_Intr;
68 with Sem_Util; use Sem_Util;
69 with Targparm; use Targparm;
70 with Sem_Type; use Sem_Type;
71 with Sem_Warn; use Sem_Warn;
72 with Sinfo; use Sinfo;
73 with Sinfo.CN; use Sinfo.CN;
74 with Snames; use Snames;
75 with Stand; use Stand;
76 with Stringt; use Stringt;
77 with Style; use Style;
78 with Tbuild; use Tbuild;
79 with Uintp; use Uintp;
80 with Urealp; use Urealp;
82 package body Sem_Res is
84 -----------------------
85 -- Local Subprograms --
86 -----------------------
88 -- Second pass (top-down) type checking and overload resolution procedures
89 -- Typ is the type required by context. These procedures propagate the type
90 -- information recursively to the descendants of N. If the node is not
91 -- overloaded, its Etype is established in the first pass. If overloaded,
92 -- the Resolve routines set the correct type. For arith. operators, the
93 -- Etype is the base type of the context.
95 -- Note that Resolve_Attribute is separated off in Sem_Attr
97 procedure Check_Discriminant_Use (N : Node_Id);
98 -- Enforce the restrictions on the use of discriminants when constraining
99 -- a component of a discriminated type (record or concurrent type).
101 procedure Check_For_Visible_Operator (N : Node_Id; T : Entity_Id);
102 -- Given a node for an operator associated with type T, check that
103 -- the operator is visible. Operators all of whose operands are
104 -- universal must be checked for visibility during resolution
105 -- because their type is not determinable based on their operands.
107 procedure Check_Fully_Declared_Prefix
108 (Typ : Entity_Id;
109 Pref : Node_Id);
110 -- Check that the type of the prefix of a dereference is not incomplete
112 procedure Check_Ghost_Context (Ghost_Id : Entity_Id; Ghost_Ref : Node_Id);
113 -- Determine whether node Ghost_Ref appears within a Ghost-friendly context
114 -- where Ghost entity Ghost_Id can safely reside.
116 function Check_Infinite_Recursion (N : Node_Id) return Boolean;
117 -- Given a call node, N, which is known to occur immediately within the
118 -- subprogram being called, determines whether it is a detectable case of
119 -- an infinite recursion, and if so, outputs appropriate messages. Returns
120 -- True if an infinite recursion is detected, and False otherwise.
122 procedure Check_Initialization_Call (N : Entity_Id; Nam : Entity_Id);
123 -- If the type of the object being initialized uses the secondary stack
124 -- directly or indirectly, create a transient scope for the call to the
125 -- init proc. This is because we do not create transient scopes for the
126 -- initialization of individual components within the init proc itself.
127 -- Could be optimized away perhaps?
129 procedure Check_No_Direct_Boolean_Operators (N : Node_Id);
130 -- N is the node for a logical operator. If the operator is predefined, and
131 -- the root type of the operands is Standard.Boolean, then a check is made
132 -- for restriction No_Direct_Boolean_Operators. This procedure also handles
133 -- the style check for Style_Check_Boolean_And_Or.
135 function Is_Atomic_Ref_With_Address (N : Node_Id) return Boolean;
136 -- N is either an indexed component or a selected component. This function
137 -- returns true if the prefix refers to an object that has an address
138 -- clause (the case in which we may want to issue a warning).
140 function Is_Definite_Access_Type (E : Entity_Id) return Boolean;
141 -- Determine whether E is an access type declared by an access declaration,
142 -- and not an (anonymous) allocator type.
144 function Is_Predefined_Op (Nam : Entity_Id) return Boolean;
145 -- Utility to check whether the entity for an operator is a predefined
146 -- operator, in which case the expression is left as an operator in the
147 -- tree (else it is rewritten into a call). An instance of an intrinsic
148 -- conversion operation may be given an operator name, but is not treated
149 -- like an operator. Note that an operator that is an imported back-end
150 -- builtin has convention Intrinsic, but is expected to be rewritten into
151 -- a call, so such an operator is not treated as predefined by this
152 -- predicate.
154 procedure Replace_Actual_Discriminants (N : Node_Id; Default : Node_Id);
155 -- If a default expression in entry call N depends on the discriminants
156 -- of the task, it must be replaced with a reference to the discriminant
157 -- of the task being called.
159 procedure Resolve_Op_Concat_Arg
160 (N : Node_Id;
161 Arg : Node_Id;
162 Typ : Entity_Id;
163 Is_Comp : Boolean);
164 -- Internal procedure for Resolve_Op_Concat to resolve one operand of
165 -- concatenation operator. The operand is either of the array type or of
166 -- the component type. If the operand is an aggregate, and the component
167 -- type is composite, this is ambiguous if component type has aggregates.
169 procedure Resolve_Op_Concat_First (N : Node_Id; Typ : Entity_Id);
170 -- Does the first part of the work of Resolve_Op_Concat
172 procedure Resolve_Op_Concat_Rest (N : Node_Id; Typ : Entity_Id);
173 -- Does the "rest" of the work of Resolve_Op_Concat, after the left operand
174 -- has been resolved. See Resolve_Op_Concat for details.
176 procedure Resolve_Allocator (N : Node_Id; Typ : Entity_Id);
177 procedure Resolve_Arithmetic_Op (N : Node_Id; Typ : Entity_Id);
178 procedure Resolve_Call (N : Node_Id; Typ : Entity_Id);
179 procedure Resolve_Case_Expression (N : Node_Id; Typ : Entity_Id);
180 procedure Resolve_Character_Literal (N : Node_Id; Typ : Entity_Id);
181 procedure Resolve_Comparison_Op (N : Node_Id; Typ : Entity_Id);
182 procedure Resolve_Entity_Name (N : Node_Id; Typ : Entity_Id);
183 procedure Resolve_Equality_Op (N : Node_Id; Typ : Entity_Id);
184 procedure Resolve_Explicit_Dereference (N : Node_Id; Typ : Entity_Id);
185 procedure Resolve_Expression_With_Actions (N : Node_Id; Typ : Entity_Id);
186 procedure Resolve_If_Expression (N : Node_Id; Typ : Entity_Id);
187 procedure Resolve_Generalized_Indexing (N : Node_Id; Typ : Entity_Id);
188 procedure Resolve_Indexed_Component (N : Node_Id; Typ : Entity_Id);
189 procedure Resolve_Integer_Literal (N : Node_Id; Typ : Entity_Id);
190 procedure Resolve_Logical_Op (N : Node_Id; Typ : Entity_Id);
191 procedure Resolve_Membership_Op (N : Node_Id; Typ : Entity_Id);
192 procedure Resolve_Null (N : Node_Id; Typ : Entity_Id);
193 procedure Resolve_Operator_Symbol (N : Node_Id; Typ : Entity_Id);
194 procedure Resolve_Op_Concat (N : Node_Id; Typ : Entity_Id);
195 procedure Resolve_Op_Expon (N : Node_Id; Typ : Entity_Id);
196 procedure Resolve_Op_Not (N : Node_Id; Typ : Entity_Id);
197 procedure Resolve_Qualified_Expression (N : Node_Id; Typ : Entity_Id);
198 procedure Resolve_Raise_Expression (N : Node_Id; Typ : Entity_Id);
199 procedure Resolve_Range (N : Node_Id; Typ : Entity_Id);
200 procedure Resolve_Real_Literal (N : Node_Id; Typ : Entity_Id);
201 procedure Resolve_Reference (N : Node_Id; Typ : Entity_Id);
202 procedure Resolve_Selected_Component (N : Node_Id; Typ : Entity_Id);
203 procedure Resolve_Shift (N : Node_Id; Typ : Entity_Id);
204 procedure Resolve_Short_Circuit (N : Node_Id; Typ : Entity_Id);
205 procedure Resolve_Slice (N : Node_Id; Typ : Entity_Id);
206 procedure Resolve_String_Literal (N : Node_Id; Typ : Entity_Id);
207 procedure Resolve_Type_Conversion (N : Node_Id; Typ : Entity_Id);
208 procedure Resolve_Unary_Op (N : Node_Id; Typ : Entity_Id);
209 procedure Resolve_Unchecked_Expression (N : Node_Id; Typ : Entity_Id);
210 procedure Resolve_Unchecked_Type_Conversion (N : Node_Id; Typ : Entity_Id);
212 function Operator_Kind
213 (Op_Name : Name_Id;
214 Is_Binary : Boolean) return Node_Kind;
215 -- Utility to map the name of an operator into the corresponding Node. Used
216 -- by other node rewriting procedures.
218 procedure Resolve_Actuals (N : Node_Id; Nam : Entity_Id);
219 -- Resolve actuals of call, and add default expressions for missing ones.
220 -- N is the Node_Id for the subprogram call, and Nam is the entity of the
221 -- called subprogram.
223 procedure Resolve_Entry_Call (N : Node_Id; Typ : Entity_Id);
224 -- Called from Resolve_Call, when the prefix denotes an entry or element
225 -- of entry family. Actuals are resolved as for subprograms, and the node
226 -- is rebuilt as an entry call. Also called for protected operations. Typ
227 -- is the context type, which is used when the operation is a protected
228 -- function with no arguments, and the return value is indexed.
230 procedure Resolve_Intrinsic_Operator (N : Node_Id; Typ : Entity_Id);
231 -- A call to a user-defined intrinsic operator is rewritten as a call to
232 -- the corresponding predefined operator, with suitable conversions. Note
233 -- that this applies only for intrinsic operators that denote predefined
234 -- operators, not ones that are intrinsic imports of back-end builtins.
236 procedure Resolve_Intrinsic_Unary_Operator (N : Node_Id; Typ : Entity_Id);
237 -- Ditto, for arithmetic unary operators
239 procedure Rewrite_Operator_As_Call (N : Node_Id; Nam : Entity_Id);
240 -- If an operator node resolves to a call to a user-defined operator,
241 -- rewrite the node as a function call.
243 procedure Make_Call_Into_Operator
244 (N : Node_Id;
245 Typ : Entity_Id;
246 Op_Id : Entity_Id);
247 -- Inverse transformation: if an operator is given in functional notation,
248 -- then after resolving the node, transform into an operator node, so
249 -- that operands are resolved properly. Recall that predefined operators
250 -- do not have a full signature and special resolution rules apply.
252 procedure Rewrite_Renamed_Operator
253 (N : Node_Id;
254 Op : Entity_Id;
255 Typ : Entity_Id);
256 -- An operator can rename another, e.g. in an instantiation. In that
257 -- case, the proper operator node must be constructed and resolved.
259 procedure Set_String_Literal_Subtype (N : Node_Id; Typ : Entity_Id);
260 -- The String_Literal_Subtype is built for all strings that are not
261 -- operands of a static concatenation operation. If the argument is
262 -- not a N_String_Literal node, then the call has no effect.
264 procedure Set_Slice_Subtype (N : Node_Id);
265 -- Build subtype of array type, with the range specified by the slice
267 procedure Simplify_Type_Conversion (N : Node_Id);
268 -- Called after N has been resolved and evaluated, but before range checks
269 -- have been applied. Currently simplifies a combination of floating-point
270 -- to integer conversion and Rounding or Truncation attribute.
272 function Unique_Fixed_Point_Type (N : Node_Id) return Entity_Id;
273 -- A universal_fixed expression in an universal context is unambiguous if
274 -- there is only one applicable fixed point type. Determining whether there
275 -- is only one requires a search over all visible entities, and happens
276 -- only in very pathological cases (see 6115-006).
278 -------------------------
279 -- Ambiguous_Character --
280 -------------------------
282 procedure Ambiguous_Character (C : Node_Id) is
283 E : Entity_Id;
285 begin
286 if Nkind (C) = N_Character_Literal then
287 Error_Msg_N ("ambiguous character literal", C);
289 -- First the ones in Standard
291 Error_Msg_N ("\\possible interpretation: Character!", C);
292 Error_Msg_N ("\\possible interpretation: Wide_Character!", C);
294 -- Include Wide_Wide_Character in Ada 2005 mode
296 if Ada_Version >= Ada_2005 then
297 Error_Msg_N ("\\possible interpretation: Wide_Wide_Character!", C);
298 end if;
300 -- Now any other types that match
302 E := Current_Entity (C);
303 while Present (E) loop
304 Error_Msg_NE ("\\possible interpretation:}!", C, Etype (E));
305 E := Homonym (E);
306 end loop;
307 end if;
308 end Ambiguous_Character;
310 -------------------------
311 -- Analyze_And_Resolve --
312 -------------------------
314 procedure Analyze_And_Resolve (N : Node_Id) is
315 begin
316 Analyze (N);
317 Resolve (N);
318 end Analyze_And_Resolve;
320 procedure Analyze_And_Resolve (N : Node_Id; Typ : Entity_Id) is
321 begin
322 Analyze (N);
323 Resolve (N, Typ);
324 end Analyze_And_Resolve;
326 -- Versions with check(s) suppressed
328 procedure Analyze_And_Resolve
329 (N : Node_Id;
330 Typ : Entity_Id;
331 Suppress : Check_Id)
333 Scop : constant Entity_Id := Current_Scope;
335 begin
336 if Suppress = All_Checks then
337 declare
338 Sva : constant Suppress_Array := Scope_Suppress.Suppress;
339 begin
340 Scope_Suppress.Suppress := (others => True);
341 Analyze_And_Resolve (N, Typ);
342 Scope_Suppress.Suppress := Sva;
343 end;
345 else
346 declare
347 Svg : constant Boolean := Scope_Suppress.Suppress (Suppress);
348 begin
349 Scope_Suppress.Suppress (Suppress) := True;
350 Analyze_And_Resolve (N, Typ);
351 Scope_Suppress.Suppress (Suppress) := Svg;
352 end;
353 end if;
355 if Current_Scope /= Scop
356 and then Scope_Is_Transient
357 then
358 -- This can only happen if a transient scope was created for an inner
359 -- expression, which will be removed upon completion of the analysis
360 -- of an enclosing construct. The transient scope must have the
361 -- suppress status of the enclosing environment, not of this Analyze
362 -- call.
364 Scope_Stack.Table (Scope_Stack.Last).Save_Scope_Suppress :=
365 Scope_Suppress;
366 end if;
367 end Analyze_And_Resolve;
369 procedure Analyze_And_Resolve
370 (N : Node_Id;
371 Suppress : Check_Id)
373 Scop : constant Entity_Id := Current_Scope;
375 begin
376 if Suppress = All_Checks then
377 declare
378 Sva : constant Suppress_Array := Scope_Suppress.Suppress;
379 begin
380 Scope_Suppress.Suppress := (others => True);
381 Analyze_And_Resolve (N);
382 Scope_Suppress.Suppress := Sva;
383 end;
385 else
386 declare
387 Svg : constant Boolean := Scope_Suppress.Suppress (Suppress);
388 begin
389 Scope_Suppress.Suppress (Suppress) := True;
390 Analyze_And_Resolve (N);
391 Scope_Suppress.Suppress (Suppress) := Svg;
392 end;
393 end if;
395 if Current_Scope /= Scop and then Scope_Is_Transient then
396 Scope_Stack.Table (Scope_Stack.Last).Save_Scope_Suppress :=
397 Scope_Suppress;
398 end if;
399 end Analyze_And_Resolve;
401 ----------------------------
402 -- Check_Discriminant_Use --
403 ----------------------------
405 procedure Check_Discriminant_Use (N : Node_Id) is
406 PN : constant Node_Id := Parent (N);
407 Disc : constant Entity_Id := Entity (N);
408 P : Node_Id;
409 D : Node_Id;
411 begin
412 -- Any use in a spec-expression is legal
414 if In_Spec_Expression then
415 null;
417 elsif Nkind (PN) = N_Range then
419 -- Discriminant cannot be used to constrain a scalar type
421 P := Parent (PN);
423 if Nkind (P) = N_Range_Constraint
424 and then Nkind (Parent (P)) = N_Subtype_Indication
425 and then Nkind (Parent (Parent (P))) = N_Component_Definition
426 then
427 Error_Msg_N ("discriminant cannot constrain scalar type", N);
429 elsif Nkind (P) = N_Index_Or_Discriminant_Constraint then
431 -- The following check catches the unusual case where a
432 -- discriminant appears within an index constraint that is part of
433 -- a larger expression within a constraint on a component, e.g. "C
434 -- : Int range 1 .. F (new A(1 .. D))". For now we only check case
435 -- of record components, and note that a similar check should also
436 -- apply in the case of discriminant constraints below. ???
438 -- Note that the check for N_Subtype_Declaration below is to
439 -- detect the valid use of discriminants in the constraints of a
440 -- subtype declaration when this subtype declaration appears
441 -- inside the scope of a record type (which is syntactically
442 -- illegal, but which may be created as part of derived type
443 -- processing for records). See Sem_Ch3.Build_Derived_Record_Type
444 -- for more info.
446 if Ekind (Current_Scope) = E_Record_Type
447 and then Scope (Disc) = Current_Scope
448 and then not
449 (Nkind (Parent (P)) = N_Subtype_Indication
450 and then
451 Nkind_In (Parent (Parent (P)), N_Component_Definition,
452 N_Subtype_Declaration)
453 and then Paren_Count (N) = 0)
454 then
455 Error_Msg_N
456 ("discriminant must appear alone in component constraint", N);
457 return;
458 end if;
460 -- Detect a common error:
462 -- type R (D : Positive := 100) is record
463 -- Name : String (1 .. D);
464 -- end record;
466 -- The default value causes an object of type R to be allocated
467 -- with room for Positive'Last characters. The RM does not mandate
468 -- the allocation of the maximum size, but that is what GNAT does
469 -- so we should warn the programmer that there is a problem.
471 Check_Large : declare
472 SI : Node_Id;
473 T : Entity_Id;
474 TB : Node_Id;
475 CB : Entity_Id;
477 function Large_Storage_Type (T : Entity_Id) return Boolean;
478 -- Return True if type T has a large enough range that any
479 -- array whose index type covered the whole range of the type
480 -- would likely raise Storage_Error.
482 ------------------------
483 -- Large_Storage_Type --
484 ------------------------
486 function Large_Storage_Type (T : Entity_Id) return Boolean is
487 begin
488 -- The type is considered large if its bounds are known at
489 -- compile time and if it requires at least as many bits as
490 -- a Positive to store the possible values.
492 return Compile_Time_Known_Value (Type_Low_Bound (T))
493 and then Compile_Time_Known_Value (Type_High_Bound (T))
494 and then
495 Minimum_Size (T, Biased => True) >=
496 RM_Size (Standard_Positive);
497 end Large_Storage_Type;
499 -- Start of processing for Check_Large
501 begin
502 -- Check that the Disc has a large range
504 if not Large_Storage_Type (Etype (Disc)) then
505 goto No_Danger;
506 end if;
508 -- If the enclosing type is limited, we allocate only the
509 -- default value, not the maximum, and there is no need for
510 -- a warning.
512 if Is_Limited_Type (Scope (Disc)) then
513 goto No_Danger;
514 end if;
516 -- Check that it is the high bound
518 if N /= High_Bound (PN)
519 or else No (Discriminant_Default_Value (Disc))
520 then
521 goto No_Danger;
522 end if;
524 -- Check the array allows a large range at this bound. First
525 -- find the array
527 SI := Parent (P);
529 if Nkind (SI) /= N_Subtype_Indication then
530 goto No_Danger;
531 end if;
533 T := Entity (Subtype_Mark (SI));
535 if not Is_Array_Type (T) then
536 goto No_Danger;
537 end if;
539 -- Next, find the dimension
541 TB := First_Index (T);
542 CB := First (Constraints (P));
543 while True
544 and then Present (TB)
545 and then Present (CB)
546 and then CB /= PN
547 loop
548 Next_Index (TB);
549 Next (CB);
550 end loop;
552 if CB /= PN then
553 goto No_Danger;
554 end if;
556 -- Now, check the dimension has a large range
558 if not Large_Storage_Type (Etype (TB)) then
559 goto No_Danger;
560 end if;
562 -- Warn about the danger
564 Error_Msg_N
565 ("??creation of & object may raise Storage_Error!",
566 Scope (Disc));
568 <<No_Danger>>
569 null;
571 end Check_Large;
572 end if;
574 -- Legal case is in index or discriminant constraint
576 elsif Nkind_In (PN, N_Index_Or_Discriminant_Constraint,
577 N_Discriminant_Association)
578 then
579 if Paren_Count (N) > 0 then
580 Error_Msg_N
581 ("discriminant in constraint must appear alone", N);
583 elsif Nkind (N) = N_Expanded_Name
584 and then Comes_From_Source (N)
585 then
586 Error_Msg_N
587 ("discriminant must appear alone as a direct name", N);
588 end if;
590 return;
592 -- Otherwise, context is an expression. It should not be within (i.e. a
593 -- subexpression of) a constraint for a component.
595 else
596 D := PN;
597 P := Parent (PN);
598 while not Nkind_In (P, N_Component_Declaration,
599 N_Subtype_Indication,
600 N_Entry_Declaration)
601 loop
602 D := P;
603 P := Parent (P);
604 exit when No (P);
605 end loop;
607 -- If the discriminant is used in an expression that is a bound of a
608 -- scalar type, an Itype is created and the bounds are attached to
609 -- its range, not to the original subtype indication. Such use is of
610 -- course a double fault.
612 if (Nkind (P) = N_Subtype_Indication
613 and then Nkind_In (Parent (P), N_Component_Definition,
614 N_Derived_Type_Definition)
615 and then D = Constraint (P))
617 -- The constraint itself may be given by a subtype indication,
618 -- rather than by a more common discrete range.
620 or else (Nkind (P) = N_Subtype_Indication
621 and then
622 Nkind (Parent (P)) = N_Index_Or_Discriminant_Constraint)
623 or else Nkind (P) = N_Entry_Declaration
624 or else Nkind (D) = N_Defining_Identifier
625 then
626 Error_Msg_N
627 ("discriminant in constraint must appear alone", N);
628 end if;
629 end if;
630 end Check_Discriminant_Use;
632 --------------------------------
633 -- Check_For_Visible_Operator --
634 --------------------------------
636 procedure Check_For_Visible_Operator (N : Node_Id; T : Entity_Id) is
637 begin
638 if Is_Invisible_Operator (N, T) then
639 Error_Msg_NE -- CODEFIX
640 ("operator for} is not directly visible!", N, First_Subtype (T));
641 Error_Msg_N -- CODEFIX
642 ("use clause would make operation legal!", N);
643 end if;
644 end Check_For_Visible_Operator;
646 ----------------------------------
647 -- Check_Fully_Declared_Prefix --
648 ----------------------------------
650 procedure Check_Fully_Declared_Prefix
651 (Typ : Entity_Id;
652 Pref : Node_Id)
654 begin
655 -- Check that the designated type of the prefix of a dereference is
656 -- not an incomplete type. This cannot be done unconditionally, because
657 -- dereferences of private types are legal in default expressions. This
658 -- case is taken care of in Check_Fully_Declared, called below. There
659 -- are also 2005 cases where it is legal for the prefix to be unfrozen.
661 -- This consideration also applies to similar checks for allocators,
662 -- qualified expressions, and type conversions.
664 -- An additional exception concerns other per-object expressions that
665 -- are not directly related to component declarations, in particular
666 -- representation pragmas for tasks. These will be per-object
667 -- expressions if they depend on discriminants or some global entity.
668 -- If the task has access discriminants, the designated type may be
669 -- incomplete at the point the expression is resolved. This resolution
670 -- takes place within the body of the initialization procedure, where
671 -- the discriminant is replaced by its discriminal.
673 if Is_Entity_Name (Pref)
674 and then Ekind (Entity (Pref)) = E_In_Parameter
675 then
676 null;
678 -- Ada 2005 (AI-326): Tagged incomplete types allowed. The wrong usages
679 -- are handled by Analyze_Access_Attribute, Analyze_Assignment,
680 -- Analyze_Object_Renaming, and Freeze_Entity.
682 elsif Ada_Version >= Ada_2005
683 and then Is_Entity_Name (Pref)
684 and then Is_Access_Type (Etype (Pref))
685 and then Ekind (Directly_Designated_Type (Etype (Pref))) =
686 E_Incomplete_Type
687 and then Is_Tagged_Type (Directly_Designated_Type (Etype (Pref)))
688 then
689 null;
690 else
691 Check_Fully_Declared (Typ, Parent (Pref));
692 end if;
693 end Check_Fully_Declared_Prefix;
695 -------------------------
696 -- Check_Ghost_Context --
697 -------------------------
699 procedure Check_Ghost_Context (Ghost_Id : Entity_Id; Ghost_Ref : Node_Id) is
700 procedure Check_Ghost_Policy (Id : Entity_Id; Err_N : Node_Id);
701 -- Verify that the Ghost policy at the point of declaration of entity Id
702 -- matches the policy at the point of reference. If this is not the case
703 -- emit an error at Err_N.
705 function Is_OK_Ghost_Context (Context : Node_Id) return Boolean;
706 -- Determine whether node Context denotes a Ghost-friendly context where
707 -- a Ghost entity can safely reside.
709 -------------------------
710 -- Is_OK_Ghost_Context --
711 -------------------------
713 function Is_OK_Ghost_Context (Context : Node_Id) return Boolean is
714 function Is_Ghost_Declaration (Decl : Node_Id) return Boolean;
715 -- Determine whether node Decl is a Ghost declaration or appears
716 -- within a Ghost declaration.
718 --------------------------
719 -- Is_Ghost_Declaration --
720 --------------------------
722 function Is_Ghost_Declaration (Decl : Node_Id) return Boolean is
723 Par : Node_Id;
724 Subp_Decl : Node_Id;
725 Subp_Id : Entity_Id;
727 begin
728 -- Climb the parent chain looking for an object declaration
730 Par := Decl;
731 while Present (Par) loop
732 case Nkind (Par) is
733 when N_Abstract_Subprogram_Declaration |
734 N_Exception_Declaration |
735 N_Exception_Renaming_Declaration |
736 N_Full_Type_Declaration |
737 N_Generic_Function_Renaming_Declaration |
738 N_Generic_Package_Declaration |
739 N_Generic_Package_Renaming_Declaration |
740 N_Generic_Procedure_Renaming_Declaration |
741 N_Generic_Subprogram_Declaration |
742 N_Number_Declaration |
743 N_Object_Declaration |
744 N_Object_Renaming_Declaration |
745 N_Package_Declaration |
746 N_Package_Renaming_Declaration |
747 N_Private_Extension_Declaration |
748 N_Private_Type_Declaration |
749 N_Subprogram_Declaration |
750 N_Subprogram_Renaming_Declaration |
751 N_Subtype_Declaration =>
752 return Is_Subject_To_Ghost (Par);
754 when others =>
755 null;
756 end case;
758 -- Special cases
760 -- A reference to a Ghost entity may appear as the default
761 -- expression of a formal parameter of a subprogram body. This
762 -- context must be treated as suitable because the relation
763 -- between the spec and the body has not been established and
764 -- the body is not marked as Ghost yet. The real check was
765 -- performed on the spec.
767 if Nkind (Par) = N_Parameter_Specification
768 and then Nkind (Parent (Parent (Par))) = N_Subprogram_Body
769 then
770 return True;
772 -- References to Ghost entities may be relocated in internally
773 -- generated bodies.
775 elsif Nkind (Par) = N_Subprogram_Body
776 and then not Comes_From_Source (Par)
777 then
778 Subp_Id := Corresponding_Spec (Par);
780 -- The original context is an expression function that has
781 -- been split into a spec and a body. The context is OK as
782 -- long as the the initial declaration is Ghost.
784 if Present (Subp_Id) then
785 Subp_Decl :=
786 Original_Node (Unit_Declaration_Node (Subp_Id));
788 if Nkind (Subp_Decl) = N_Expression_Function then
789 return Is_Subject_To_Ghost (Subp_Decl);
790 end if;
791 end if;
793 -- Otherwise this is either an internal body or an internal
794 -- completion. Both are OK because the real check was done
795 -- before expansion activities.
797 return True;
798 end if;
800 -- Prevent the search from going too far
802 if Is_Body_Or_Package_Declaration (Par) then
803 return False;
804 end if;
806 Par := Parent (Par);
807 end loop;
809 return False;
810 end Is_Ghost_Declaration;
812 -- Start of processing for Is_OK_Ghost_Context
814 begin
815 -- The Ghost entity appears within an assertion expression
817 if In_Assertion_Expr > 0 then
818 return True;
820 -- The Ghost entity is part of a declaration or its completion
822 elsif Is_Ghost_Declaration (Context) then
823 return True;
825 -- The Ghost entity is referenced within a Ghost statement
827 elsif Is_Ghost_Statement_Or_Pragma (Context) then
828 return True;
830 else
831 return False;
832 end if;
833 end Is_OK_Ghost_Context;
835 ------------------------
836 -- Check_Ghost_Policy --
837 ------------------------
839 procedure Check_Ghost_Policy (Id : Entity_Id; Err_N : Node_Id) is
840 Policy : constant Name_Id := Policy_In_Effect (Name_Ghost);
842 begin
843 -- The Ghost policy in effect a the point of declaration and at the
844 -- point of use must match (SPARK RM 6.9(14)).
846 if Is_Checked_Ghost_Entity (Id) and then Policy = Name_Ignore then
847 Error_Msg_Sloc := Sloc (Err_N);
849 Error_Msg_N ("incompatible ghost policies in effect", Err_N);
850 Error_Msg_NE ("\& declared with ghost policy Check", Err_N, Id);
851 Error_Msg_NE ("\& used # with ghost policy Ignore", Err_N, Id);
853 elsif Is_Ignored_Ghost_Entity (Id) and then Policy = Name_Check then
854 Error_Msg_Sloc := Sloc (Err_N);
856 Error_Msg_N ("incompatible ghost policies in effect", Err_N);
857 Error_Msg_NE ("\& declared with ghost policy Ignore", Err_N, Id);
858 Error_Msg_NE ("\& used # with ghost policy Check", Err_N, Id);
859 end if;
860 end Check_Ghost_Policy;
862 -- Start of processing for Check_Ghost_Context
864 begin
865 -- Once it has been established that the reference to the Ghost entity
866 -- is within a suitable context, ensure that the policy at the point of
867 -- declaration and at the point of use match.
869 if Is_OK_Ghost_Context (Ghost_Ref) then
870 Check_Ghost_Policy (Ghost_Id, Ghost_Ref);
872 -- Otherwise the Ghost entity appears in a non-Ghost context and affects
873 -- its behavior or value.
875 else
876 Error_Msg_N
877 ("ghost entity cannot appear in this context (SPARK RM 6.9(12))",
878 Ghost_Ref);
879 end if;
880 end Check_Ghost_Context;
882 ------------------------------
883 -- Check_Infinite_Recursion --
884 ------------------------------
886 function Check_Infinite_Recursion (N : Node_Id) return Boolean is
887 P : Node_Id;
888 C : Node_Id;
890 function Same_Argument_List return Boolean;
891 -- Check whether list of actuals is identical to list of formals of
892 -- called function (which is also the enclosing scope).
894 ------------------------
895 -- Same_Argument_List --
896 ------------------------
898 function Same_Argument_List return Boolean is
899 A : Node_Id;
900 F : Entity_Id;
901 Subp : Entity_Id;
903 begin
904 if not Is_Entity_Name (Name (N)) then
905 return False;
906 else
907 Subp := Entity (Name (N));
908 end if;
910 F := First_Formal (Subp);
911 A := First_Actual (N);
912 while Present (F) and then Present (A) loop
913 if not Is_Entity_Name (A)
914 or else Entity (A) /= F
915 then
916 return False;
917 end if;
919 Next_Actual (A);
920 Next_Formal (F);
921 end loop;
923 return True;
924 end Same_Argument_List;
926 -- Start of processing for Check_Infinite_Recursion
928 begin
929 -- Special case, if this is a procedure call and is a call to the
930 -- current procedure with the same argument list, then this is for
931 -- sure an infinite recursion and we insert a call to raise SE.
933 if Is_List_Member (N)
934 and then List_Length (List_Containing (N)) = 1
935 and then Same_Argument_List
936 then
937 declare
938 P : constant Node_Id := Parent (N);
939 begin
940 if Nkind (P) = N_Handled_Sequence_Of_Statements
941 and then Nkind (Parent (P)) = N_Subprogram_Body
942 and then Is_Empty_List (Declarations (Parent (P)))
943 then
944 Error_Msg_Warn := SPARK_Mode /= On;
945 Error_Msg_N ("!infinite recursion<<", N);
946 Error_Msg_N ("\!Storage_Error [<<", N);
947 Insert_Action (N,
948 Make_Raise_Storage_Error (Sloc (N),
949 Reason => SE_Infinite_Recursion));
950 return True;
951 end if;
952 end;
953 end if;
955 -- If not that special case, search up tree, quitting if we reach a
956 -- construct (e.g. a conditional) that tells us that this is not a
957 -- case for an infinite recursion warning.
959 C := N;
960 loop
961 P := Parent (C);
963 -- If no parent, then we were not inside a subprogram, this can for
964 -- example happen when processing certain pragmas in a spec. Just
965 -- return False in this case.
967 if No (P) then
968 return False;
969 end if;
971 -- Done if we get to subprogram body, this is definitely an infinite
972 -- recursion case if we did not find anything to stop us.
974 exit when Nkind (P) = N_Subprogram_Body;
976 -- If appearing in conditional, result is false
978 if Nkind_In (P, N_Or_Else,
979 N_And_Then,
980 N_Case_Expression,
981 N_Case_Statement,
982 N_If_Expression,
983 N_If_Statement)
984 then
985 return False;
987 elsif Nkind (P) = N_Handled_Sequence_Of_Statements
988 and then C /= First (Statements (P))
989 then
990 -- If the call is the expression of a return statement and the
991 -- actuals are identical to the formals, it's worth a warning.
992 -- However, we skip this if there is an immediately preceding
993 -- raise statement, since the call is never executed.
995 -- Furthermore, this corresponds to a common idiom:
997 -- function F (L : Thing) return Boolean is
998 -- begin
999 -- raise Program_Error;
1000 -- return F (L);
1001 -- end F;
1003 -- for generating a stub function
1005 if Nkind (Parent (N)) = N_Simple_Return_Statement
1006 and then Same_Argument_List
1007 then
1008 exit when not Is_List_Member (Parent (N));
1010 -- OK, return statement is in a statement list, look for raise
1012 declare
1013 Nod : Node_Id;
1015 begin
1016 -- Skip past N_Freeze_Entity nodes generated by expansion
1018 Nod := Prev (Parent (N));
1019 while Present (Nod)
1020 and then Nkind (Nod) = N_Freeze_Entity
1021 loop
1022 Prev (Nod);
1023 end loop;
1025 -- If no raise statement, give warning. We look at the
1026 -- original node, because in the case of "raise ... with
1027 -- ...", the node has been transformed into a call.
1029 exit when Nkind (Original_Node (Nod)) /= N_Raise_Statement
1030 and then
1031 (Nkind (Nod) not in N_Raise_xxx_Error
1032 or else Present (Condition (Nod)));
1033 end;
1034 end if;
1036 return False;
1038 else
1039 C := P;
1040 end if;
1041 end loop;
1043 Error_Msg_Warn := SPARK_Mode /= On;
1044 Error_Msg_N ("!possible infinite recursion<<", N);
1045 Error_Msg_N ("\!??Storage_Error ]<<", N);
1047 return True;
1048 end Check_Infinite_Recursion;
1050 -------------------------------
1051 -- Check_Initialization_Call --
1052 -------------------------------
1054 procedure Check_Initialization_Call (N : Entity_Id; Nam : Entity_Id) is
1055 Typ : constant Entity_Id := Etype (First_Formal (Nam));
1057 function Uses_SS (T : Entity_Id) return Boolean;
1058 -- Check whether the creation of an object of the type will involve
1059 -- use of the secondary stack. If T is a record type, this is true
1060 -- if the expression for some component uses the secondary stack, e.g.
1061 -- through a call to a function that returns an unconstrained value.
1062 -- False if T is controlled, because cleanups occur elsewhere.
1064 -------------
1065 -- Uses_SS --
1066 -------------
1068 function Uses_SS (T : Entity_Id) return Boolean is
1069 Comp : Entity_Id;
1070 Expr : Node_Id;
1071 Full_Type : Entity_Id := Underlying_Type (T);
1073 begin
1074 -- Normally we want to use the underlying type, but if it's not set
1075 -- then continue with T.
1077 if not Present (Full_Type) then
1078 Full_Type := T;
1079 end if;
1081 if Is_Controlled (Full_Type) then
1082 return False;
1084 elsif Is_Array_Type (Full_Type) then
1085 return Uses_SS (Component_Type (Full_Type));
1087 elsif Is_Record_Type (Full_Type) then
1088 Comp := First_Component (Full_Type);
1089 while Present (Comp) loop
1090 if Ekind (Comp) = E_Component
1091 and then Nkind (Parent (Comp)) = N_Component_Declaration
1092 then
1093 -- The expression for a dynamic component may be rewritten
1094 -- as a dereference, so retrieve original node.
1096 Expr := Original_Node (Expression (Parent (Comp)));
1098 -- Return True if the expression is a call to a function
1099 -- (including an attribute function such as Image, or a
1100 -- user-defined operator) with a result that requires a
1101 -- transient scope.
1103 if (Nkind (Expr) = N_Function_Call
1104 or else Nkind (Expr) in N_Op
1105 or else (Nkind (Expr) = N_Attribute_Reference
1106 and then Present (Expressions (Expr))))
1107 and then Requires_Transient_Scope (Etype (Expr))
1108 then
1109 return True;
1111 elsif Uses_SS (Etype (Comp)) then
1112 return True;
1113 end if;
1114 end if;
1116 Next_Component (Comp);
1117 end loop;
1119 return False;
1121 else
1122 return False;
1123 end if;
1124 end Uses_SS;
1126 -- Start of processing for Check_Initialization_Call
1128 begin
1129 -- Establish a transient scope if the type needs it
1131 if Uses_SS (Typ) then
1132 Establish_Transient_Scope (First_Actual (N), Sec_Stack => True);
1133 end if;
1134 end Check_Initialization_Call;
1136 ---------------------------------------
1137 -- Check_No_Direct_Boolean_Operators --
1138 ---------------------------------------
1140 procedure Check_No_Direct_Boolean_Operators (N : Node_Id) is
1141 begin
1142 if Scope (Entity (N)) = Standard_Standard
1143 and then Root_Type (Etype (Left_Opnd (N))) = Standard_Boolean
1144 then
1145 -- Restriction only applies to original source code
1147 if Comes_From_Source (N) then
1148 Check_Restriction (No_Direct_Boolean_Operators, N);
1149 end if;
1150 end if;
1152 -- Do style check (but skip if in instance, error is on template)
1154 if Style_Check then
1155 if not In_Instance then
1156 Check_Boolean_Operator (N);
1157 end if;
1158 end if;
1159 end Check_No_Direct_Boolean_Operators;
1161 ------------------------------
1162 -- Check_Parameterless_Call --
1163 ------------------------------
1165 procedure Check_Parameterless_Call (N : Node_Id) is
1166 Nam : Node_Id;
1168 function Prefix_Is_Access_Subp return Boolean;
1169 -- If the prefix is of an access_to_subprogram type, the node must be
1170 -- rewritten as a call. Ditto if the prefix is overloaded and all its
1171 -- interpretations are access to subprograms.
1173 ---------------------------
1174 -- Prefix_Is_Access_Subp --
1175 ---------------------------
1177 function Prefix_Is_Access_Subp return Boolean is
1178 I : Interp_Index;
1179 It : Interp;
1181 begin
1182 -- If the context is an attribute reference that can apply to
1183 -- functions, this is never a parameterless call (RM 4.1.4(6)).
1185 if Nkind (Parent (N)) = N_Attribute_Reference
1186 and then Nam_In (Attribute_Name (Parent (N)), Name_Address,
1187 Name_Code_Address,
1188 Name_Access)
1189 then
1190 return False;
1191 end if;
1193 if not Is_Overloaded (N) then
1194 return
1195 Ekind (Etype (N)) = E_Subprogram_Type
1196 and then Base_Type (Etype (Etype (N))) /= Standard_Void_Type;
1197 else
1198 Get_First_Interp (N, I, It);
1199 while Present (It.Typ) loop
1200 if Ekind (It.Typ) /= E_Subprogram_Type
1201 or else Base_Type (Etype (It.Typ)) = Standard_Void_Type
1202 then
1203 return False;
1204 end if;
1206 Get_Next_Interp (I, It);
1207 end loop;
1209 return True;
1210 end if;
1211 end Prefix_Is_Access_Subp;
1213 -- Start of processing for Check_Parameterless_Call
1215 begin
1216 -- Defend against junk stuff if errors already detected
1218 if Total_Errors_Detected /= 0 then
1219 if Nkind (N) in N_Has_Etype and then Etype (N) = Any_Type then
1220 return;
1221 elsif Nkind (N) in N_Has_Chars
1222 and then Chars (N) in Error_Name_Or_No_Name
1223 then
1224 return;
1225 end if;
1227 Require_Entity (N);
1228 end if;
1230 -- If the context expects a value, and the name is a procedure, this is
1231 -- most likely a missing 'Access. Don't try to resolve the parameterless
1232 -- call, error will be caught when the outer call is analyzed.
1234 if Is_Entity_Name (N)
1235 and then Ekind (Entity (N)) = E_Procedure
1236 and then not Is_Overloaded (N)
1237 and then
1238 Nkind_In (Parent (N), N_Parameter_Association,
1239 N_Function_Call,
1240 N_Procedure_Call_Statement)
1241 then
1242 return;
1243 end if;
1245 -- Rewrite as call if overloadable entity that is (or could be, in the
1246 -- overloaded case) a function call. If we know for sure that the entity
1247 -- is an enumeration literal, we do not rewrite it.
1249 -- If the entity is the name of an operator, it cannot be a call because
1250 -- operators cannot have default parameters. In this case, this must be
1251 -- a string whose contents coincide with an operator name. Set the kind
1252 -- of the node appropriately.
1254 if (Is_Entity_Name (N)
1255 and then Nkind (N) /= N_Operator_Symbol
1256 and then Is_Overloadable (Entity (N))
1257 and then (Ekind (Entity (N)) /= E_Enumeration_Literal
1258 or else Is_Overloaded (N)))
1260 -- Rewrite as call if it is an explicit dereference of an expression of
1261 -- a subprogram access type, and the subprogram type is not that of a
1262 -- procedure or entry.
1264 or else
1265 (Nkind (N) = N_Explicit_Dereference and then Prefix_Is_Access_Subp)
1267 -- Rewrite as call if it is a selected component which is a function,
1268 -- this is the case of a call to a protected function (which may be
1269 -- overloaded with other protected operations).
1271 or else
1272 (Nkind (N) = N_Selected_Component
1273 and then (Ekind (Entity (Selector_Name (N))) = E_Function
1274 or else
1275 (Ekind_In (Entity (Selector_Name (N)), E_Entry,
1276 E_Procedure)
1277 and then Is_Overloaded (Selector_Name (N)))))
1279 -- If one of the above three conditions is met, rewrite as call. Apply
1280 -- the rewriting only once.
1282 then
1283 if Nkind (Parent (N)) /= N_Function_Call
1284 or else N /= Name (Parent (N))
1285 then
1287 -- This may be a prefixed call that was not fully analyzed, e.g.
1288 -- an actual in an instance.
1290 if Ada_Version >= Ada_2005
1291 and then Nkind (N) = N_Selected_Component
1292 and then Is_Dispatching_Operation (Entity (Selector_Name (N)))
1293 then
1294 Analyze_Selected_Component (N);
1296 if Nkind (N) /= N_Selected_Component then
1297 return;
1298 end if;
1299 end if;
1301 -- The node is the name of the parameterless call. Preserve its
1302 -- descendants, which may be complex expressions.
1304 Nam := Relocate_Node (N);
1306 -- If overloaded, overload set belongs to new copy
1308 Save_Interps (N, Nam);
1310 -- Change node to parameterless function call (note that the
1311 -- Parameter_Associations associations field is left set to Empty,
1312 -- its normal default value since there are no parameters)
1314 Change_Node (N, N_Function_Call);
1315 Set_Name (N, Nam);
1316 Set_Sloc (N, Sloc (Nam));
1317 Analyze_Call (N);
1318 end if;
1320 elsif Nkind (N) = N_Parameter_Association then
1321 Check_Parameterless_Call (Explicit_Actual_Parameter (N));
1323 elsif Nkind (N) = N_Operator_Symbol then
1324 Change_Operator_Symbol_To_String_Literal (N);
1325 Set_Is_Overloaded (N, False);
1326 Set_Etype (N, Any_String);
1327 end if;
1328 end Check_Parameterless_Call;
1330 --------------------------------
1331 -- Is_Atomic_Ref_With_Address --
1332 --------------------------------
1334 function Is_Atomic_Ref_With_Address (N : Node_Id) return Boolean is
1335 Pref : constant Node_Id := Prefix (N);
1337 begin
1338 if not Is_Entity_Name (Pref) then
1339 return False;
1341 else
1342 declare
1343 Pent : constant Entity_Id := Entity (Pref);
1344 Ptyp : constant Entity_Id := Etype (Pent);
1345 begin
1346 return not Is_Access_Type (Ptyp)
1347 and then (Is_Atomic (Ptyp) or else Is_Atomic (Pent))
1348 and then Present (Address_Clause (Pent));
1349 end;
1350 end if;
1351 end Is_Atomic_Ref_With_Address;
1353 -----------------------------
1354 -- Is_Definite_Access_Type --
1355 -----------------------------
1357 function Is_Definite_Access_Type (E : Entity_Id) return Boolean is
1358 Btyp : constant Entity_Id := Base_Type (E);
1359 begin
1360 return Ekind (Btyp) = E_Access_Type
1361 or else (Ekind (Btyp) = E_Access_Subprogram_Type
1362 and then Comes_From_Source (Btyp));
1363 end Is_Definite_Access_Type;
1365 ----------------------
1366 -- Is_Predefined_Op --
1367 ----------------------
1369 function Is_Predefined_Op (Nam : Entity_Id) return Boolean is
1370 begin
1371 -- Predefined operators are intrinsic subprograms
1373 if not Is_Intrinsic_Subprogram (Nam) then
1374 return False;
1375 end if;
1377 -- A call to a back-end builtin is never a predefined operator
1379 if Is_Imported (Nam) and then Present (Interface_Name (Nam)) then
1380 return False;
1381 end if;
1383 return not Is_Generic_Instance (Nam)
1384 and then Chars (Nam) in Any_Operator_Name
1385 and then (No (Alias (Nam)) or else Is_Predefined_Op (Alias (Nam)));
1386 end Is_Predefined_Op;
1388 -----------------------------
1389 -- Make_Call_Into_Operator --
1390 -----------------------------
1392 procedure Make_Call_Into_Operator
1393 (N : Node_Id;
1394 Typ : Entity_Id;
1395 Op_Id : Entity_Id)
1397 Op_Name : constant Name_Id := Chars (Op_Id);
1398 Act1 : Node_Id := First_Actual (N);
1399 Act2 : Node_Id := Next_Actual (Act1);
1400 Error : Boolean := False;
1401 Func : constant Entity_Id := Entity (Name (N));
1402 Is_Binary : constant Boolean := Present (Act2);
1403 Op_Node : Node_Id;
1404 Opnd_Type : Entity_Id;
1405 Orig_Type : Entity_Id := Empty;
1406 Pack : Entity_Id;
1408 type Kind_Test is access function (E : Entity_Id) return Boolean;
1410 function Operand_Type_In_Scope (S : Entity_Id) return Boolean;
1411 -- If the operand is not universal, and the operator is given by an
1412 -- expanded name, verify that the operand has an interpretation with a
1413 -- type defined in the given scope of the operator.
1415 function Type_In_P (Test : Kind_Test) return Entity_Id;
1416 -- Find a type of the given class in package Pack that contains the
1417 -- operator.
1419 ---------------------------
1420 -- Operand_Type_In_Scope --
1421 ---------------------------
1423 function Operand_Type_In_Scope (S : Entity_Id) return Boolean is
1424 Nod : constant Node_Id := Right_Opnd (Op_Node);
1425 I : Interp_Index;
1426 It : Interp;
1428 begin
1429 if not Is_Overloaded (Nod) then
1430 return Scope (Base_Type (Etype (Nod))) = S;
1432 else
1433 Get_First_Interp (Nod, I, It);
1434 while Present (It.Typ) loop
1435 if Scope (Base_Type (It.Typ)) = S then
1436 return True;
1437 end if;
1439 Get_Next_Interp (I, It);
1440 end loop;
1442 return False;
1443 end if;
1444 end Operand_Type_In_Scope;
1446 ---------------
1447 -- Type_In_P --
1448 ---------------
1450 function Type_In_P (Test : Kind_Test) return Entity_Id is
1451 E : Entity_Id;
1453 function In_Decl return Boolean;
1454 -- Verify that node is not part of the type declaration for the
1455 -- candidate type, which would otherwise be invisible.
1457 -------------
1458 -- In_Decl --
1459 -------------
1461 function In_Decl return Boolean is
1462 Decl_Node : constant Node_Id := Parent (E);
1463 N2 : Node_Id;
1465 begin
1466 N2 := N;
1468 if Etype (E) = Any_Type then
1469 return True;
1471 elsif No (Decl_Node) then
1472 return False;
1474 else
1475 while Present (N2)
1476 and then Nkind (N2) /= N_Compilation_Unit
1477 loop
1478 if N2 = Decl_Node then
1479 return True;
1480 else
1481 N2 := Parent (N2);
1482 end if;
1483 end loop;
1485 return False;
1486 end if;
1487 end In_Decl;
1489 -- Start of processing for Type_In_P
1491 begin
1492 -- If the context type is declared in the prefix package, this is the
1493 -- desired base type.
1495 if Scope (Base_Type (Typ)) = Pack and then Test (Typ) then
1496 return Base_Type (Typ);
1498 else
1499 E := First_Entity (Pack);
1500 while Present (E) loop
1501 if Test (E)
1502 and then not In_Decl
1503 then
1504 return E;
1505 end if;
1507 Next_Entity (E);
1508 end loop;
1510 return Empty;
1511 end if;
1512 end Type_In_P;
1514 -- Start of processing for Make_Call_Into_Operator
1516 begin
1517 Op_Node := New_Node (Operator_Kind (Op_Name, Is_Binary), Sloc (N));
1519 -- Binary operator
1521 if Is_Binary then
1522 Set_Left_Opnd (Op_Node, Relocate_Node (Act1));
1523 Set_Right_Opnd (Op_Node, Relocate_Node (Act2));
1524 Save_Interps (Act1, Left_Opnd (Op_Node));
1525 Save_Interps (Act2, Right_Opnd (Op_Node));
1526 Act1 := Left_Opnd (Op_Node);
1527 Act2 := Right_Opnd (Op_Node);
1529 -- Unary operator
1531 else
1532 Set_Right_Opnd (Op_Node, Relocate_Node (Act1));
1533 Save_Interps (Act1, Right_Opnd (Op_Node));
1534 Act1 := Right_Opnd (Op_Node);
1535 end if;
1537 -- If the operator is denoted by an expanded name, and the prefix is
1538 -- not Standard, but the operator is a predefined one whose scope is
1539 -- Standard, then this is an implicit_operator, inserted as an
1540 -- interpretation by the procedure of the same name. This procedure
1541 -- overestimates the presence of implicit operators, because it does
1542 -- not examine the type of the operands. Verify now that the operand
1543 -- type appears in the given scope. If right operand is universal,
1544 -- check the other operand. In the case of concatenation, either
1545 -- argument can be the component type, so check the type of the result.
1546 -- If both arguments are literals, look for a type of the right kind
1547 -- defined in the given scope. This elaborate nonsense is brought to
1548 -- you courtesy of b33302a. The type itself must be frozen, so we must
1549 -- find the type of the proper class in the given scope.
1551 -- A final wrinkle is the multiplication operator for fixed point types,
1552 -- which is defined in Standard only, and not in the scope of the
1553 -- fixed point type itself.
1555 if Nkind (Name (N)) = N_Expanded_Name then
1556 Pack := Entity (Prefix (Name (N)));
1558 -- If this is a package renaming, get renamed entity, which will be
1559 -- the scope of the operands if operaton is type-correct.
1561 if Present (Renamed_Entity (Pack)) then
1562 Pack := Renamed_Entity (Pack);
1563 end if;
1565 -- If the entity being called is defined in the given package, it is
1566 -- a renaming of a predefined operator, and known to be legal.
1568 if Scope (Entity (Name (N))) = Pack
1569 and then Pack /= Standard_Standard
1570 then
1571 null;
1573 -- Visibility does not need to be checked in an instance: if the
1574 -- operator was not visible in the generic it has been diagnosed
1575 -- already, else there is an implicit copy of it in the instance.
1577 elsif In_Instance then
1578 null;
1580 elsif Nam_In (Op_Name, Name_Op_Multiply, Name_Op_Divide)
1581 and then Is_Fixed_Point_Type (Etype (Left_Opnd (Op_Node)))
1582 and then Is_Fixed_Point_Type (Etype (Right_Opnd (Op_Node)))
1583 then
1584 if Pack /= Standard_Standard then
1585 Error := True;
1586 end if;
1588 -- Ada 2005 AI-420: Predefined equality on Universal_Access is
1589 -- available.
1591 elsif Ada_Version >= Ada_2005
1592 and then Nam_In (Op_Name, Name_Op_Eq, Name_Op_Ne)
1593 and then Ekind (Etype (Act1)) = E_Anonymous_Access_Type
1594 then
1595 null;
1597 else
1598 Opnd_Type := Base_Type (Etype (Right_Opnd (Op_Node)));
1600 if Op_Name = Name_Op_Concat then
1601 Opnd_Type := Base_Type (Typ);
1603 elsif (Scope (Opnd_Type) = Standard_Standard
1604 and then Is_Binary)
1605 or else (Nkind (Right_Opnd (Op_Node)) = N_Attribute_Reference
1606 and then Is_Binary
1607 and then not Comes_From_Source (Opnd_Type))
1608 then
1609 Opnd_Type := Base_Type (Etype (Left_Opnd (Op_Node)));
1610 end if;
1612 if Scope (Opnd_Type) = Standard_Standard then
1614 -- Verify that the scope contains a type that corresponds to
1615 -- the given literal. Optimize the case where Pack is Standard.
1617 if Pack /= Standard_Standard then
1619 if Opnd_Type = Universal_Integer then
1620 Orig_Type := Type_In_P (Is_Integer_Type'Access);
1622 elsif Opnd_Type = Universal_Real then
1623 Orig_Type := Type_In_P (Is_Real_Type'Access);
1625 elsif Opnd_Type = Any_String then
1626 Orig_Type := Type_In_P (Is_String_Type'Access);
1628 elsif Opnd_Type = Any_Access then
1629 Orig_Type := Type_In_P (Is_Definite_Access_Type'Access);
1631 elsif Opnd_Type = Any_Composite then
1632 Orig_Type := Type_In_P (Is_Composite_Type'Access);
1634 if Present (Orig_Type) then
1635 if Has_Private_Component (Orig_Type) then
1636 Orig_Type := Empty;
1637 else
1638 Set_Etype (Act1, Orig_Type);
1640 if Is_Binary then
1641 Set_Etype (Act2, Orig_Type);
1642 end if;
1643 end if;
1644 end if;
1646 else
1647 Orig_Type := Empty;
1648 end if;
1650 Error := No (Orig_Type);
1651 end if;
1653 elsif Ekind (Opnd_Type) = E_Allocator_Type
1654 and then No (Type_In_P (Is_Definite_Access_Type'Access))
1655 then
1656 Error := True;
1658 -- If the type is defined elsewhere, and the operator is not
1659 -- defined in the given scope (by a renaming declaration, e.g.)
1660 -- then this is an error as well. If an extension of System is
1661 -- present, and the type may be defined there, Pack must be
1662 -- System itself.
1664 elsif Scope (Opnd_Type) /= Pack
1665 and then Scope (Op_Id) /= Pack
1666 and then (No (System_Aux_Id)
1667 or else Scope (Opnd_Type) /= System_Aux_Id
1668 or else Pack /= Scope (System_Aux_Id))
1669 then
1670 if not Is_Overloaded (Right_Opnd (Op_Node)) then
1671 Error := True;
1672 else
1673 Error := not Operand_Type_In_Scope (Pack);
1674 end if;
1676 elsif Pack = Standard_Standard
1677 and then not Operand_Type_In_Scope (Standard_Standard)
1678 then
1679 Error := True;
1680 end if;
1681 end if;
1683 if Error then
1684 Error_Msg_Node_2 := Pack;
1685 Error_Msg_NE
1686 ("& not declared in&", N, Selector_Name (Name (N)));
1687 Set_Etype (N, Any_Type);
1688 return;
1690 -- Detect a mismatch between the context type and the result type
1691 -- in the named package, which is otherwise not detected if the
1692 -- operands are universal. Check is only needed if source entity is
1693 -- an operator, not a function that renames an operator.
1695 elsif Nkind (Parent (N)) /= N_Type_Conversion
1696 and then Ekind (Entity (Name (N))) = E_Operator
1697 and then Is_Numeric_Type (Typ)
1698 and then not Is_Universal_Numeric_Type (Typ)
1699 and then Scope (Base_Type (Typ)) /= Pack
1700 and then not In_Instance
1701 then
1702 if Is_Fixed_Point_Type (Typ)
1703 and then Nam_In (Op_Name, Name_Op_Multiply, Name_Op_Divide)
1704 then
1705 -- Already checked above
1707 null;
1709 -- Operator may be defined in an extension of System
1711 elsif Present (System_Aux_Id)
1712 and then Scope (Opnd_Type) = System_Aux_Id
1713 then
1714 null;
1716 else
1717 -- Could we use Wrong_Type here??? (this would require setting
1718 -- Etype (N) to the actual type found where Typ was expected).
1720 Error_Msg_NE ("expect }", N, Typ);
1721 end if;
1722 end if;
1723 end if;
1725 Set_Chars (Op_Node, Op_Name);
1727 if not Is_Private_Type (Etype (N)) then
1728 Set_Etype (Op_Node, Base_Type (Etype (N)));
1729 else
1730 Set_Etype (Op_Node, Etype (N));
1731 end if;
1733 -- If this is a call to a function that renames a predefined equality,
1734 -- the renaming declaration provides a type that must be used to
1735 -- resolve the operands. This must be done now because resolution of
1736 -- the equality node will not resolve any remaining ambiguity, and it
1737 -- assumes that the first operand is not overloaded.
1739 if Nam_In (Op_Name, Name_Op_Eq, Name_Op_Ne)
1740 and then Ekind (Func) = E_Function
1741 and then Is_Overloaded (Act1)
1742 then
1743 Resolve (Act1, Base_Type (Etype (First_Formal (Func))));
1744 Resolve (Act2, Base_Type (Etype (First_Formal (Func))));
1745 end if;
1747 Set_Entity (Op_Node, Op_Id);
1748 Generate_Reference (Op_Id, N, ' ');
1750 -- Do rewrite setting Comes_From_Source on the result if the original
1751 -- call came from source. Although it is not strictly the case that the
1752 -- operator as such comes from the source, logically it corresponds
1753 -- exactly to the function call in the source, so it should be marked
1754 -- this way (e.g. to make sure that validity checks work fine).
1756 declare
1757 CS : constant Boolean := Comes_From_Source (N);
1758 begin
1759 Rewrite (N, Op_Node);
1760 Set_Comes_From_Source (N, CS);
1761 end;
1763 -- If this is an arithmetic operator and the result type is private,
1764 -- the operands and the result must be wrapped in conversion to
1765 -- expose the underlying numeric type and expand the proper checks,
1766 -- e.g. on division.
1768 if Is_Private_Type (Typ) then
1769 case Nkind (N) is
1770 when N_Op_Add | N_Op_Subtract | N_Op_Multiply | N_Op_Divide |
1771 N_Op_Expon | N_Op_Mod | N_Op_Rem =>
1772 Resolve_Intrinsic_Operator (N, Typ);
1774 when N_Op_Plus | N_Op_Minus | N_Op_Abs =>
1775 Resolve_Intrinsic_Unary_Operator (N, Typ);
1777 when others =>
1778 Resolve (N, Typ);
1779 end case;
1780 else
1781 Resolve (N, Typ);
1782 end if;
1784 -- If in ASIS_Mode, propagate operand types to original actuals of
1785 -- function call, which would otherwise not be fully resolved. If
1786 -- the call has already been constant-folded, nothing to do. We
1787 -- relocate the operand nodes rather than copy them, to preserve
1788 -- original_node pointers, given that the operands themselves may
1789 -- have been rewritten. If the call was itself a rewriting of an
1790 -- operator node, nothing to do.
1792 if ASIS_Mode
1793 and then Nkind (N) in N_Op
1794 and then Nkind (Original_Node (N)) = N_Function_Call
1795 then
1796 declare
1797 L : Node_Id;
1798 R : constant Node_Id := Right_Opnd (N);
1800 Old_First : constant Node_Id :=
1801 First (Parameter_Associations (Original_Node (N)));
1802 Old_Sec : Node_Id;
1804 begin
1805 if Is_Binary then
1806 L := Left_Opnd (N);
1807 Old_Sec := Next (Old_First);
1809 -- If the original call has named associations, replace the
1810 -- explicit actual parameter in the association with the proper
1811 -- resolved operand.
1813 if Nkind (Old_First) = N_Parameter_Association then
1814 if Chars (Selector_Name (Old_First)) =
1815 Chars (First_Entity (Op_Id))
1816 then
1817 Rewrite (Explicit_Actual_Parameter (Old_First),
1818 Relocate_Node (L));
1819 else
1820 Rewrite (Explicit_Actual_Parameter (Old_First),
1821 Relocate_Node (R));
1822 end if;
1824 else
1825 Rewrite (Old_First, Relocate_Node (L));
1826 end if;
1828 if Nkind (Old_Sec) = N_Parameter_Association then
1829 if Chars (Selector_Name (Old_Sec)) =
1830 Chars (First_Entity (Op_Id))
1831 then
1832 Rewrite (Explicit_Actual_Parameter (Old_Sec),
1833 Relocate_Node (L));
1834 else
1835 Rewrite (Explicit_Actual_Parameter (Old_Sec),
1836 Relocate_Node (R));
1837 end if;
1839 else
1840 Rewrite (Old_Sec, Relocate_Node (R));
1841 end if;
1843 else
1844 if Nkind (Old_First) = N_Parameter_Association then
1845 Rewrite (Explicit_Actual_Parameter (Old_First),
1846 Relocate_Node (R));
1847 else
1848 Rewrite (Old_First, Relocate_Node (R));
1849 end if;
1850 end if;
1851 end;
1853 Set_Parent (Original_Node (N), Parent (N));
1854 end if;
1855 end Make_Call_Into_Operator;
1857 -------------------
1858 -- Operator_Kind --
1859 -------------------
1861 function Operator_Kind
1862 (Op_Name : Name_Id;
1863 Is_Binary : Boolean) return Node_Kind
1865 Kind : Node_Kind;
1867 begin
1868 -- Use CASE statement or array???
1870 if Is_Binary then
1871 if Op_Name = Name_Op_And then
1872 Kind := N_Op_And;
1873 elsif Op_Name = Name_Op_Or then
1874 Kind := N_Op_Or;
1875 elsif Op_Name = Name_Op_Xor then
1876 Kind := N_Op_Xor;
1877 elsif Op_Name = Name_Op_Eq then
1878 Kind := N_Op_Eq;
1879 elsif Op_Name = Name_Op_Ne then
1880 Kind := N_Op_Ne;
1881 elsif Op_Name = Name_Op_Lt then
1882 Kind := N_Op_Lt;
1883 elsif Op_Name = Name_Op_Le then
1884 Kind := N_Op_Le;
1885 elsif Op_Name = Name_Op_Gt then
1886 Kind := N_Op_Gt;
1887 elsif Op_Name = Name_Op_Ge then
1888 Kind := N_Op_Ge;
1889 elsif Op_Name = Name_Op_Add then
1890 Kind := N_Op_Add;
1891 elsif Op_Name = Name_Op_Subtract then
1892 Kind := N_Op_Subtract;
1893 elsif Op_Name = Name_Op_Concat then
1894 Kind := N_Op_Concat;
1895 elsif Op_Name = Name_Op_Multiply then
1896 Kind := N_Op_Multiply;
1897 elsif Op_Name = Name_Op_Divide then
1898 Kind := N_Op_Divide;
1899 elsif Op_Name = Name_Op_Mod then
1900 Kind := N_Op_Mod;
1901 elsif Op_Name = Name_Op_Rem then
1902 Kind := N_Op_Rem;
1903 elsif Op_Name = Name_Op_Expon then
1904 Kind := N_Op_Expon;
1905 else
1906 raise Program_Error;
1907 end if;
1909 -- Unary operators
1911 else
1912 if Op_Name = Name_Op_Add then
1913 Kind := N_Op_Plus;
1914 elsif Op_Name = Name_Op_Subtract then
1915 Kind := N_Op_Minus;
1916 elsif Op_Name = Name_Op_Abs then
1917 Kind := N_Op_Abs;
1918 elsif Op_Name = Name_Op_Not then
1919 Kind := N_Op_Not;
1920 else
1921 raise Program_Error;
1922 end if;
1923 end if;
1925 return Kind;
1926 end Operator_Kind;
1928 ----------------------------
1929 -- Preanalyze_And_Resolve --
1930 ----------------------------
1932 procedure Preanalyze_And_Resolve (N : Node_Id; T : Entity_Id) is
1933 Save_Full_Analysis : constant Boolean := Full_Analysis;
1935 begin
1936 Full_Analysis := False;
1937 Expander_Mode_Save_And_Set (False);
1939 -- Normally, we suppress all checks for this preanalysis. There is no
1940 -- point in processing them now, since they will be applied properly
1941 -- and in the proper location when the default expressions reanalyzed
1942 -- and reexpanded later on. We will also have more information at that
1943 -- point for possible suppression of individual checks.
1945 -- However, in SPARK mode, most expansion is suppressed, and this
1946 -- later reanalysis and reexpansion may not occur. SPARK mode does
1947 -- require the setting of checking flags for proof purposes, so we
1948 -- do the SPARK preanalysis without suppressing checks.
1950 -- This special handling for SPARK mode is required for example in the
1951 -- case of Ada 2012 constructs such as quantified expressions, which are
1952 -- expanded in two separate steps.
1954 if GNATprove_Mode then
1955 Analyze_And_Resolve (N, T);
1956 else
1957 Analyze_And_Resolve (N, T, Suppress => All_Checks);
1958 end if;
1960 Expander_Mode_Restore;
1961 Full_Analysis := Save_Full_Analysis;
1962 end Preanalyze_And_Resolve;
1964 -- Version without context type
1966 procedure Preanalyze_And_Resolve (N : Node_Id) is
1967 Save_Full_Analysis : constant Boolean := Full_Analysis;
1969 begin
1970 Full_Analysis := False;
1971 Expander_Mode_Save_And_Set (False);
1973 Analyze (N);
1974 Resolve (N, Etype (N), Suppress => All_Checks);
1976 Expander_Mode_Restore;
1977 Full_Analysis := Save_Full_Analysis;
1978 end Preanalyze_And_Resolve;
1980 ----------------------------------
1981 -- Replace_Actual_Discriminants --
1982 ----------------------------------
1984 procedure Replace_Actual_Discriminants (N : Node_Id; Default : Node_Id) is
1985 Loc : constant Source_Ptr := Sloc (N);
1986 Tsk : Node_Id := Empty;
1988 function Process_Discr (Nod : Node_Id) return Traverse_Result;
1989 -- Comment needed???
1991 -------------------
1992 -- Process_Discr --
1993 -------------------
1995 function Process_Discr (Nod : Node_Id) return Traverse_Result is
1996 Ent : Entity_Id;
1998 begin
1999 if Nkind (Nod) = N_Identifier then
2000 Ent := Entity (Nod);
2002 if Present (Ent)
2003 and then Ekind (Ent) = E_Discriminant
2004 then
2005 Rewrite (Nod,
2006 Make_Selected_Component (Loc,
2007 Prefix => New_Copy_Tree (Tsk, New_Sloc => Loc),
2008 Selector_Name => Make_Identifier (Loc, Chars (Ent))));
2010 Set_Etype (Nod, Etype (Ent));
2011 end if;
2013 end if;
2015 return OK;
2016 end Process_Discr;
2018 procedure Replace_Discrs is new Traverse_Proc (Process_Discr);
2020 -- Start of processing for Replace_Actual_Discriminants
2022 begin
2023 if not Expander_Active then
2024 return;
2025 end if;
2027 if Nkind (Name (N)) = N_Selected_Component then
2028 Tsk := Prefix (Name (N));
2030 elsif Nkind (Name (N)) = N_Indexed_Component then
2031 Tsk := Prefix (Prefix (Name (N)));
2032 end if;
2034 if No (Tsk) then
2035 return;
2036 else
2037 Replace_Discrs (Default);
2038 end if;
2039 end Replace_Actual_Discriminants;
2041 -------------
2042 -- Resolve --
2043 -------------
2045 procedure Resolve (N : Node_Id; Typ : Entity_Id) is
2046 Ambiguous : Boolean := False;
2047 Ctx_Type : Entity_Id := Typ;
2048 Expr_Type : Entity_Id := Empty; -- prevent junk warning
2049 Err_Type : Entity_Id := Empty;
2050 Found : Boolean := False;
2051 From_Lib : Boolean;
2052 I : Interp_Index;
2053 I1 : Interp_Index := 0; -- prevent junk warning
2054 It : Interp;
2055 It1 : Interp;
2056 Seen : Entity_Id := Empty; -- prevent junk warning
2058 function Comes_From_Predefined_Lib_Unit (Nod : Node_Id) return Boolean;
2059 -- Determine whether a node comes from a predefined library unit or
2060 -- Standard.
2062 procedure Patch_Up_Value (N : Node_Id; Typ : Entity_Id);
2063 -- Try and fix up a literal so that it matches its expected type. New
2064 -- literals are manufactured if necessary to avoid cascaded errors.
2066 procedure Report_Ambiguous_Argument;
2067 -- Additional diagnostics when an ambiguous call has an ambiguous
2068 -- argument (typically a controlling actual).
2070 procedure Resolution_Failed;
2071 -- Called when attempt at resolving current expression fails
2073 ------------------------------------
2074 -- Comes_From_Predefined_Lib_Unit --
2075 -------------------------------------
2077 function Comes_From_Predefined_Lib_Unit (Nod : Node_Id) return Boolean is
2078 begin
2079 return
2080 Sloc (Nod) = Standard_Location
2081 or else Is_Predefined_File_Name
2082 (Unit_File_Name (Get_Source_Unit (Sloc (Nod))));
2083 end Comes_From_Predefined_Lib_Unit;
2085 --------------------
2086 -- Patch_Up_Value --
2087 --------------------
2089 procedure Patch_Up_Value (N : Node_Id; Typ : Entity_Id) is
2090 begin
2091 if Nkind (N) = N_Integer_Literal and then Is_Real_Type (Typ) then
2092 Rewrite (N,
2093 Make_Real_Literal (Sloc (N),
2094 Realval => UR_From_Uint (Intval (N))));
2095 Set_Etype (N, Universal_Real);
2096 Set_Is_Static_Expression (N);
2098 elsif Nkind (N) = N_Real_Literal and then Is_Integer_Type (Typ) then
2099 Rewrite (N,
2100 Make_Integer_Literal (Sloc (N),
2101 Intval => UR_To_Uint (Realval (N))));
2102 Set_Etype (N, Universal_Integer);
2103 Set_Is_Static_Expression (N);
2105 elsif Nkind (N) = N_String_Literal
2106 and then Is_Character_Type (Typ)
2107 then
2108 Set_Character_Literal_Name (Char_Code (Character'Pos ('A')));
2109 Rewrite (N,
2110 Make_Character_Literal (Sloc (N),
2111 Chars => Name_Find,
2112 Char_Literal_Value =>
2113 UI_From_Int (Character'Pos ('A'))));
2114 Set_Etype (N, Any_Character);
2115 Set_Is_Static_Expression (N);
2117 elsif Nkind (N) /= N_String_Literal and then Is_String_Type (Typ) then
2118 Rewrite (N,
2119 Make_String_Literal (Sloc (N),
2120 Strval => End_String));
2122 elsif Nkind (N) = N_Range then
2123 Patch_Up_Value (Low_Bound (N), Typ);
2124 Patch_Up_Value (High_Bound (N), Typ);
2125 end if;
2126 end Patch_Up_Value;
2128 -------------------------------
2129 -- Report_Ambiguous_Argument --
2130 -------------------------------
2132 procedure Report_Ambiguous_Argument is
2133 Arg : constant Node_Id := First (Parameter_Associations (N));
2134 I : Interp_Index;
2135 It : Interp;
2137 begin
2138 if Nkind (Arg) = N_Function_Call
2139 and then Is_Entity_Name (Name (Arg))
2140 and then Is_Overloaded (Name (Arg))
2141 then
2142 Error_Msg_NE ("ambiguous call to&", Arg, Name (Arg));
2144 -- Could use comments on what is going on here???
2146 Get_First_Interp (Name (Arg), I, It);
2147 while Present (It.Nam) loop
2148 Error_Msg_Sloc := Sloc (It.Nam);
2150 if Nkind (Parent (It.Nam)) = N_Full_Type_Declaration then
2151 Error_Msg_N ("interpretation (inherited) #!", Arg);
2152 else
2153 Error_Msg_N ("interpretation #!", Arg);
2154 end if;
2156 Get_Next_Interp (I, It);
2157 end loop;
2158 end if;
2159 end Report_Ambiguous_Argument;
2161 -----------------------
2162 -- Resolution_Failed --
2163 -----------------------
2165 procedure Resolution_Failed is
2166 begin
2167 Patch_Up_Value (N, Typ);
2168 Set_Etype (N, Typ);
2169 Debug_A_Exit ("resolving ", N, " (done, resolution failed)");
2170 Set_Is_Overloaded (N, False);
2172 -- The caller will return without calling the expander, so we need
2173 -- to set the analyzed flag. Note that it is fine to set Analyzed
2174 -- to True even if we are in the middle of a shallow analysis,
2175 -- (see the spec of sem for more details) since this is an error
2176 -- situation anyway, and there is no point in repeating the
2177 -- analysis later (indeed it won't work to repeat it later, since
2178 -- we haven't got a clear resolution of which entity is being
2179 -- referenced.)
2181 Set_Analyzed (N, True);
2182 return;
2183 end Resolution_Failed;
2185 -- Start of processing for Resolve
2187 begin
2188 if N = Error then
2189 return;
2190 end if;
2192 -- Access attribute on remote subprogram cannot be used for a non-remote
2193 -- access-to-subprogram type.
2195 if Nkind (N) = N_Attribute_Reference
2196 and then Nam_In (Attribute_Name (N), Name_Access,
2197 Name_Unrestricted_Access,
2198 Name_Unchecked_Access)
2199 and then Comes_From_Source (N)
2200 and then Is_Entity_Name (Prefix (N))
2201 and then Is_Subprogram (Entity (Prefix (N)))
2202 and then Is_Remote_Call_Interface (Entity (Prefix (N)))
2203 and then not Is_Remote_Access_To_Subprogram_Type (Typ)
2204 then
2205 Error_Msg_N
2206 ("prefix must statically denote a non-remote subprogram", N);
2207 end if;
2209 From_Lib := Comes_From_Predefined_Lib_Unit (N);
2211 -- If the context is a Remote_Access_To_Subprogram, access attributes
2212 -- must be resolved with the corresponding fat pointer. There is no need
2213 -- to check for the attribute name since the return type of an
2214 -- attribute is never a remote type.
2216 if Nkind (N) = N_Attribute_Reference
2217 and then Comes_From_Source (N)
2218 and then (Is_Remote_Call_Interface (Typ) or else Is_Remote_Types (Typ))
2219 then
2220 declare
2221 Attr : constant Attribute_Id :=
2222 Get_Attribute_Id (Attribute_Name (N));
2223 Pref : constant Node_Id := Prefix (N);
2224 Decl : Node_Id;
2225 Spec : Node_Id;
2226 Is_Remote : Boolean := True;
2228 begin
2229 -- Check that Typ is a remote access-to-subprogram type
2231 if Is_Remote_Access_To_Subprogram_Type (Typ) then
2233 -- Prefix (N) must statically denote a remote subprogram
2234 -- declared in a package specification.
2236 if Attr = Attribute_Access or else
2237 Attr = Attribute_Unchecked_Access or else
2238 Attr = Attribute_Unrestricted_Access
2239 then
2240 Decl := Unit_Declaration_Node (Entity (Pref));
2242 if Nkind (Decl) = N_Subprogram_Body then
2243 Spec := Corresponding_Spec (Decl);
2245 if Present (Spec) then
2246 Decl := Unit_Declaration_Node (Spec);
2247 end if;
2248 end if;
2250 Spec := Parent (Decl);
2252 if not Is_Entity_Name (Prefix (N))
2253 or else Nkind (Spec) /= N_Package_Specification
2254 or else
2255 not Is_Remote_Call_Interface (Defining_Entity (Spec))
2256 then
2257 Is_Remote := False;
2258 Error_Msg_N
2259 ("prefix must statically denote a remote subprogram ",
2261 end if;
2263 -- If we are generating code in distributed mode, perform
2264 -- semantic checks against corresponding remote entities.
2266 if Expander_Active
2267 and then Get_PCS_Name /= Name_No_DSA
2268 then
2269 Check_Subtype_Conformant
2270 (New_Id => Entity (Prefix (N)),
2271 Old_Id => Designated_Type
2272 (Corresponding_Remote_Type (Typ)),
2273 Err_Loc => N);
2275 if Is_Remote then
2276 Process_Remote_AST_Attribute (N, Typ);
2277 end if;
2278 end if;
2279 end if;
2280 end if;
2281 end;
2282 end if;
2284 Debug_A_Entry ("resolving ", N);
2286 if Debug_Flag_V then
2287 Write_Overloads (N);
2288 end if;
2290 if Comes_From_Source (N) then
2291 if Is_Fixed_Point_Type (Typ) then
2292 Check_Restriction (No_Fixed_Point, N);
2294 elsif Is_Floating_Point_Type (Typ)
2295 and then Typ /= Universal_Real
2296 and then Typ /= Any_Real
2297 then
2298 Check_Restriction (No_Floating_Point, N);
2299 end if;
2300 end if;
2302 -- Return if already analyzed
2304 if Analyzed (N) then
2305 Debug_A_Exit ("resolving ", N, " (done, already analyzed)");
2306 Analyze_Dimension (N);
2307 return;
2309 -- Any case of Any_Type as the Etype value means that we had a
2310 -- previous error.
2312 elsif Etype (N) = Any_Type then
2313 Debug_A_Exit ("resolving ", N, " (done, Etype = Any_Type)");
2314 return;
2315 end if;
2317 Check_Parameterless_Call (N);
2319 -- The resolution of an Expression_With_Actions is determined by
2320 -- its Expression.
2322 if Nkind (N) = N_Expression_With_Actions then
2323 Resolve (Expression (N), Typ);
2325 Found := True;
2326 Expr_Type := Etype (Expression (N));
2328 -- If not overloaded, then we know the type, and all that needs doing
2329 -- is to check that this type is compatible with the context.
2331 elsif not Is_Overloaded (N) then
2332 Found := Covers (Typ, Etype (N));
2333 Expr_Type := Etype (N);
2335 -- In the overloaded case, we must select the interpretation that
2336 -- is compatible with the context (i.e. the type passed to Resolve)
2338 else
2339 -- Loop through possible interpretations
2341 Get_First_Interp (N, I, It);
2342 Interp_Loop : while Present (It.Typ) loop
2344 if Debug_Flag_V then
2345 Write_Str ("Interp: ");
2346 Write_Interp (It);
2347 end if;
2349 -- We are only interested in interpretations that are compatible
2350 -- with the expected type, any other interpretations are ignored.
2352 if not Covers (Typ, It.Typ) then
2353 if Debug_Flag_V then
2354 Write_Str (" interpretation incompatible with context");
2355 Write_Eol;
2356 end if;
2358 else
2359 -- Skip the current interpretation if it is disabled by an
2360 -- abstract operator. This action is performed only when the
2361 -- type against which we are resolving is the same as the
2362 -- type of the interpretation.
2364 if Ada_Version >= Ada_2005
2365 and then It.Typ = Typ
2366 and then Typ /= Universal_Integer
2367 and then Typ /= Universal_Real
2368 and then Present (It.Abstract_Op)
2369 then
2370 if Debug_Flag_V then
2371 Write_Line ("Skip.");
2372 end if;
2374 goto Continue;
2375 end if;
2377 -- First matching interpretation
2379 if not Found then
2380 Found := True;
2381 I1 := I;
2382 Seen := It.Nam;
2383 Expr_Type := It.Typ;
2385 -- Matching interpretation that is not the first, maybe an
2386 -- error, but there are some cases where preference rules are
2387 -- used to choose between the two possibilities. These and
2388 -- some more obscure cases are handled in Disambiguate.
2390 else
2391 -- If the current statement is part of a predefined library
2392 -- unit, then all interpretations which come from user level
2393 -- packages should not be considered. Check previous and
2394 -- current one.
2396 if From_Lib then
2397 if not Comes_From_Predefined_Lib_Unit (It.Nam) then
2398 goto Continue;
2400 elsif not Comes_From_Predefined_Lib_Unit (Seen) then
2402 -- Previous interpretation must be discarded
2404 I1 := I;
2405 Seen := It.Nam;
2406 Expr_Type := It.Typ;
2407 Set_Entity (N, Seen);
2408 goto Continue;
2409 end if;
2410 end if;
2412 -- Otherwise apply further disambiguation steps
2414 Error_Msg_Sloc := Sloc (Seen);
2415 It1 := Disambiguate (N, I1, I, Typ);
2417 -- Disambiguation has succeeded. Skip the remaining
2418 -- interpretations.
2420 if It1 /= No_Interp then
2421 Seen := It1.Nam;
2422 Expr_Type := It1.Typ;
2424 while Present (It.Typ) loop
2425 Get_Next_Interp (I, It);
2426 end loop;
2428 else
2429 -- Before we issue an ambiguity complaint, check for
2430 -- the case of a subprogram call where at least one
2431 -- of the arguments is Any_Type, and if so, suppress
2432 -- the message, since it is a cascaded error.
2434 if Nkind (N) in N_Subprogram_Call then
2435 declare
2436 A : Node_Id;
2437 E : Node_Id;
2439 begin
2440 A := First_Actual (N);
2441 while Present (A) loop
2442 E := A;
2444 if Nkind (E) = N_Parameter_Association then
2445 E := Explicit_Actual_Parameter (E);
2446 end if;
2448 if Etype (E) = Any_Type then
2449 if Debug_Flag_V then
2450 Write_Str ("Any_Type in call");
2451 Write_Eol;
2452 end if;
2454 exit Interp_Loop;
2455 end if;
2457 Next_Actual (A);
2458 end loop;
2459 end;
2461 elsif Nkind (N) in N_Binary_Op
2462 and then (Etype (Left_Opnd (N)) = Any_Type
2463 or else Etype (Right_Opnd (N)) = Any_Type)
2464 then
2465 exit Interp_Loop;
2467 elsif Nkind (N) in N_Unary_Op
2468 and then Etype (Right_Opnd (N)) = Any_Type
2469 then
2470 exit Interp_Loop;
2471 end if;
2473 -- Not that special case, so issue message using the
2474 -- flag Ambiguous to control printing of the header
2475 -- message only at the start of an ambiguous set.
2477 if not Ambiguous then
2478 if Nkind (N) = N_Function_Call
2479 and then Nkind (Name (N)) = N_Explicit_Dereference
2480 then
2481 Error_Msg_N
2482 ("ambiguous expression "
2483 & "(cannot resolve indirect call)!", N);
2484 else
2485 Error_Msg_NE -- CODEFIX
2486 ("ambiguous expression (cannot resolve&)!",
2487 N, It.Nam);
2488 end if;
2490 Ambiguous := True;
2492 if Nkind (Parent (Seen)) = N_Full_Type_Declaration then
2493 Error_Msg_N
2494 ("\\possible interpretation (inherited)#!", N);
2495 else
2496 Error_Msg_N -- CODEFIX
2497 ("\\possible interpretation#!", N);
2498 end if;
2500 if Nkind (N) in N_Subprogram_Call
2501 and then Present (Parameter_Associations (N))
2502 then
2503 Report_Ambiguous_Argument;
2504 end if;
2505 end if;
2507 Error_Msg_Sloc := Sloc (It.Nam);
2509 -- By default, the error message refers to the candidate
2510 -- interpretation. But if it is a predefined operator, it
2511 -- is implicitly declared at the declaration of the type
2512 -- of the operand. Recover the sloc of that declaration
2513 -- for the error message.
2515 if Nkind (N) in N_Op
2516 and then Scope (It.Nam) = Standard_Standard
2517 and then not Is_Overloaded (Right_Opnd (N))
2518 and then Scope (Base_Type (Etype (Right_Opnd (N)))) /=
2519 Standard_Standard
2520 then
2521 Err_Type := First_Subtype (Etype (Right_Opnd (N)));
2523 if Comes_From_Source (Err_Type)
2524 and then Present (Parent (Err_Type))
2525 then
2526 Error_Msg_Sloc := Sloc (Parent (Err_Type));
2527 end if;
2529 elsif Nkind (N) in N_Binary_Op
2530 and then Scope (It.Nam) = Standard_Standard
2531 and then not Is_Overloaded (Left_Opnd (N))
2532 and then Scope (Base_Type (Etype (Left_Opnd (N)))) /=
2533 Standard_Standard
2534 then
2535 Err_Type := First_Subtype (Etype (Left_Opnd (N)));
2537 if Comes_From_Source (Err_Type)
2538 and then Present (Parent (Err_Type))
2539 then
2540 Error_Msg_Sloc := Sloc (Parent (Err_Type));
2541 end if;
2543 -- If this is an indirect call, use the subprogram_type
2544 -- in the message, to have a meaningful location. Also
2545 -- indicate if this is an inherited operation, created
2546 -- by a type declaration.
2548 elsif Nkind (N) = N_Function_Call
2549 and then Nkind (Name (N)) = N_Explicit_Dereference
2550 and then Is_Type (It.Nam)
2551 then
2552 Err_Type := It.Nam;
2553 Error_Msg_Sloc :=
2554 Sloc (Associated_Node_For_Itype (Err_Type));
2555 else
2556 Err_Type := Empty;
2557 end if;
2559 if Nkind (N) in N_Op
2560 and then Scope (It.Nam) = Standard_Standard
2561 and then Present (Err_Type)
2562 then
2563 -- Special-case the message for universal_fixed
2564 -- operators, which are not declared with the type
2565 -- of the operand, but appear forever in Standard.
2567 if It.Typ = Universal_Fixed
2568 and then Scope (It.Nam) = Standard_Standard
2569 then
2570 Error_Msg_N
2571 ("\\possible interpretation as universal_fixed "
2572 & "operation (RM 4.5.5 (19))", N);
2573 else
2574 Error_Msg_N
2575 ("\\possible interpretation (predefined)#!", N);
2576 end if;
2578 elsif
2579 Nkind (Parent (It.Nam)) = N_Full_Type_Declaration
2580 then
2581 Error_Msg_N
2582 ("\\possible interpretation (inherited)#!", N);
2583 else
2584 Error_Msg_N -- CODEFIX
2585 ("\\possible interpretation#!", N);
2586 end if;
2588 end if;
2589 end if;
2591 -- We have a matching interpretation, Expr_Type is the type
2592 -- from this interpretation, and Seen is the entity.
2594 -- For an operator, just set the entity name. The type will be
2595 -- set by the specific operator resolution routine.
2597 if Nkind (N) in N_Op then
2598 Set_Entity (N, Seen);
2599 Generate_Reference (Seen, N);
2601 elsif Nkind (N) = N_Case_Expression then
2602 Set_Etype (N, Expr_Type);
2604 elsif Nkind (N) = N_Character_Literal then
2605 Set_Etype (N, Expr_Type);
2607 elsif Nkind (N) = N_If_Expression then
2608 Set_Etype (N, Expr_Type);
2610 -- AI05-0139-2: Expression is overloaded because type has
2611 -- implicit dereference. If type matches context, no implicit
2612 -- dereference is involved.
2614 elsif Has_Implicit_Dereference (Expr_Type) then
2615 Set_Etype (N, Expr_Type);
2616 Set_Is_Overloaded (N, False);
2617 exit Interp_Loop;
2619 elsif Is_Overloaded (N)
2620 and then Present (It.Nam)
2621 and then Ekind (It.Nam) = E_Discriminant
2622 and then Has_Implicit_Dereference (It.Nam)
2623 then
2624 -- If the node is a general indexing, the dereference is
2625 -- is inserted when resolving the rewritten form, else
2626 -- insert it now.
2628 if Nkind (N) /= N_Indexed_Component
2629 or else No (Generalized_Indexing (N))
2630 then
2631 Build_Explicit_Dereference (N, It.Nam);
2632 end if;
2634 -- For an explicit dereference, attribute reference, range,
2635 -- short-circuit form (which is not an operator node), or call
2636 -- with a name that is an explicit dereference, there is
2637 -- nothing to be done at this point.
2639 elsif Nkind_In (N, N_Explicit_Dereference,
2640 N_Attribute_Reference,
2641 N_And_Then,
2642 N_Indexed_Component,
2643 N_Or_Else,
2644 N_Range,
2645 N_Selected_Component,
2646 N_Slice)
2647 or else Nkind (Name (N)) = N_Explicit_Dereference
2648 then
2649 null;
2651 -- For procedure or function calls, set the type of the name,
2652 -- and also the entity pointer for the prefix.
2654 elsif Nkind (N) in N_Subprogram_Call
2655 and then Is_Entity_Name (Name (N))
2656 then
2657 Set_Etype (Name (N), Expr_Type);
2658 Set_Entity (Name (N), Seen);
2659 Generate_Reference (Seen, Name (N));
2661 elsif Nkind (N) = N_Function_Call
2662 and then Nkind (Name (N)) = N_Selected_Component
2663 then
2664 Set_Etype (Name (N), Expr_Type);
2665 Set_Entity (Selector_Name (Name (N)), Seen);
2666 Generate_Reference (Seen, Selector_Name (Name (N)));
2668 -- For all other cases, just set the type of the Name
2670 else
2671 Set_Etype (Name (N), Expr_Type);
2672 end if;
2674 end if;
2676 <<Continue>>
2678 -- Move to next interpretation
2680 exit Interp_Loop when No (It.Typ);
2682 Get_Next_Interp (I, It);
2683 end loop Interp_Loop;
2684 end if;
2686 -- At this stage Found indicates whether or not an acceptable
2687 -- interpretation exists. If not, then we have an error, except that if
2688 -- the context is Any_Type as a result of some other error, then we
2689 -- suppress the error report.
2691 if not Found then
2692 if Typ /= Any_Type then
2694 -- If type we are looking for is Void, then this is the procedure
2695 -- call case, and the error is simply that what we gave is not a
2696 -- procedure name (we think of procedure calls as expressions with
2697 -- types internally, but the user doesn't think of them this way).
2699 if Typ = Standard_Void_Type then
2701 -- Special case message if function used as a procedure
2703 if Nkind (N) = N_Procedure_Call_Statement
2704 and then Is_Entity_Name (Name (N))
2705 and then Ekind (Entity (Name (N))) = E_Function
2706 then
2707 Error_Msg_NE
2708 ("cannot use function & in a procedure call",
2709 Name (N), Entity (Name (N)));
2711 -- Otherwise give general message (not clear what cases this
2712 -- covers, but no harm in providing for them).
2714 else
2715 Error_Msg_N ("expect procedure name in procedure call", N);
2716 end if;
2718 Found := True;
2720 -- Otherwise we do have a subexpression with the wrong type
2722 -- Check for the case of an allocator which uses an access type
2723 -- instead of the designated type. This is a common error and we
2724 -- specialize the message, posting an error on the operand of the
2725 -- allocator, complaining that we expected the designated type of
2726 -- the allocator.
2728 elsif Nkind (N) = N_Allocator
2729 and then Is_Access_Type (Typ)
2730 and then Is_Access_Type (Etype (N))
2731 and then Designated_Type (Etype (N)) = Typ
2732 then
2733 Wrong_Type (Expression (N), Designated_Type (Typ));
2734 Found := True;
2736 -- Check for view mismatch on Null in instances, for which the
2737 -- view-swapping mechanism has no identifier.
2739 elsif (In_Instance or else In_Inlined_Body)
2740 and then (Nkind (N) = N_Null)
2741 and then Is_Private_Type (Typ)
2742 and then Is_Access_Type (Full_View (Typ))
2743 then
2744 Resolve (N, Full_View (Typ));
2745 Set_Etype (N, Typ);
2746 return;
2748 -- Check for an aggregate. Sometimes we can get bogus aggregates
2749 -- from misuse of parentheses, and we are about to complain about
2750 -- the aggregate without even looking inside it.
2752 -- Instead, if we have an aggregate of type Any_Composite, then
2753 -- analyze and resolve the component fields, and then only issue
2754 -- another message if we get no errors doing this (otherwise
2755 -- assume that the errors in the aggregate caused the problem).
2757 elsif Nkind (N) = N_Aggregate
2758 and then Etype (N) = Any_Composite
2759 then
2760 -- Disable expansion in any case. If there is a type mismatch
2761 -- it may be fatal to try to expand the aggregate. The flag
2762 -- would otherwise be set to false when the error is posted.
2764 Expander_Active := False;
2766 declare
2767 procedure Check_Aggr (Aggr : Node_Id);
2768 -- Check one aggregate, and set Found to True if we have a
2769 -- definite error in any of its elements
2771 procedure Check_Elmt (Aelmt : Node_Id);
2772 -- Check one element of aggregate and set Found to True if
2773 -- we definitely have an error in the element.
2775 ----------------
2776 -- Check_Aggr --
2777 ----------------
2779 procedure Check_Aggr (Aggr : Node_Id) is
2780 Elmt : Node_Id;
2782 begin
2783 if Present (Expressions (Aggr)) then
2784 Elmt := First (Expressions (Aggr));
2785 while Present (Elmt) loop
2786 Check_Elmt (Elmt);
2787 Next (Elmt);
2788 end loop;
2789 end if;
2791 if Present (Component_Associations (Aggr)) then
2792 Elmt := First (Component_Associations (Aggr));
2793 while Present (Elmt) loop
2795 -- If this is a default-initialized component, then
2796 -- there is nothing to check. The box will be
2797 -- replaced by the appropriate call during late
2798 -- expansion.
2800 if not Box_Present (Elmt) then
2801 Check_Elmt (Expression (Elmt));
2802 end if;
2804 Next (Elmt);
2805 end loop;
2806 end if;
2807 end Check_Aggr;
2809 ----------------
2810 -- Check_Elmt --
2811 ----------------
2813 procedure Check_Elmt (Aelmt : Node_Id) is
2814 begin
2815 -- If we have a nested aggregate, go inside it (to
2816 -- attempt a naked analyze-resolve of the aggregate can
2817 -- cause undesirable cascaded errors). Do not resolve
2818 -- expression if it needs a type from context, as for
2819 -- integer * fixed expression.
2821 if Nkind (Aelmt) = N_Aggregate then
2822 Check_Aggr (Aelmt);
2824 else
2825 Analyze (Aelmt);
2827 if not Is_Overloaded (Aelmt)
2828 and then Etype (Aelmt) /= Any_Fixed
2829 then
2830 Resolve (Aelmt);
2831 end if;
2833 if Etype (Aelmt) = Any_Type then
2834 Found := True;
2835 end if;
2836 end if;
2837 end Check_Elmt;
2839 begin
2840 Check_Aggr (N);
2841 end;
2842 end if;
2844 -- Looks like we have a type error, but check for special case
2845 -- of Address wanted, integer found, with the configuration pragma
2846 -- Allow_Integer_Address active. If we have this case, introduce
2847 -- an unchecked conversion to allow the integer expression to be
2848 -- treated as an Address. The reverse case of integer wanted,
2849 -- Address found, is treated in an analogous manner.
2851 if Address_Integer_Convert_OK (Typ, Etype (N)) then
2852 Rewrite (N, Unchecked_Convert_To (Typ, Relocate_Node (N)));
2853 Analyze_And_Resolve (N, Typ);
2854 return;
2855 end if;
2857 -- That special Allow_Integer_Address check did not appply, so we
2858 -- have a real type error. If an error message was issued already,
2859 -- Found got reset to True, so if it's still False, issue standard
2860 -- Wrong_Type message.
2862 if not Found then
2863 if Is_Overloaded (N) and then Nkind (N) = N_Function_Call then
2864 declare
2865 Subp_Name : Node_Id;
2867 begin
2868 if Is_Entity_Name (Name (N)) then
2869 Subp_Name := Name (N);
2871 elsif Nkind (Name (N)) = N_Selected_Component then
2873 -- Protected operation: retrieve operation name
2875 Subp_Name := Selector_Name (Name (N));
2877 else
2878 raise Program_Error;
2879 end if;
2881 Error_Msg_Node_2 := Typ;
2882 Error_Msg_NE
2883 ("no visible interpretation of& "
2884 & "matches expected type&", N, Subp_Name);
2885 end;
2887 if All_Errors_Mode then
2888 declare
2889 Index : Interp_Index;
2890 It : Interp;
2892 begin
2893 Error_Msg_N ("\\possible interpretations:", N);
2895 Get_First_Interp (Name (N), Index, It);
2896 while Present (It.Nam) loop
2897 Error_Msg_Sloc := Sloc (It.Nam);
2898 Error_Msg_Node_2 := It.Nam;
2899 Error_Msg_NE
2900 ("\\ type& for & declared#", N, It.Typ);
2901 Get_Next_Interp (Index, It);
2902 end loop;
2903 end;
2905 else
2906 Error_Msg_N ("\use -gnatf for details", N);
2907 end if;
2909 else
2910 Wrong_Type (N, Typ);
2911 end if;
2912 end if;
2913 end if;
2915 Resolution_Failed;
2916 return;
2918 -- Test if we have more than one interpretation for the context
2920 elsif Ambiguous then
2921 Resolution_Failed;
2922 return;
2924 -- Only one intepretation
2926 else
2927 -- In Ada 2005, if we have something like "X : T := 2 + 2;", where
2928 -- the "+" on T is abstract, and the operands are of universal type,
2929 -- the above code will have (incorrectly) resolved the "+" to the
2930 -- universal one in Standard. Therefore check for this case and give
2931 -- an error. We can't do this earlier, because it would cause legal
2932 -- cases to get errors (when some other type has an abstract "+").
2934 if Ada_Version >= Ada_2005
2935 and then Nkind (N) in N_Op
2936 and then Is_Overloaded (N)
2937 and then Is_Universal_Numeric_Type (Etype (Entity (N)))
2938 then
2939 Get_First_Interp (N, I, It);
2940 while Present (It.Typ) loop
2941 if Present (It.Abstract_Op) and then
2942 Etype (It.Abstract_Op) = Typ
2943 then
2944 Error_Msg_NE
2945 ("cannot call abstract subprogram &!", N, It.Abstract_Op);
2946 return;
2947 end if;
2949 Get_Next_Interp (I, It);
2950 end loop;
2951 end if;
2953 -- Here we have an acceptable interpretation for the context
2955 -- Propagate type information and normalize tree for various
2956 -- predefined operations. If the context only imposes a class of
2957 -- types, rather than a specific type, propagate the actual type
2958 -- downward.
2960 if Typ = Any_Integer or else
2961 Typ = Any_Boolean or else
2962 Typ = Any_Modular or else
2963 Typ = Any_Real or else
2964 Typ = Any_Discrete
2965 then
2966 Ctx_Type := Expr_Type;
2968 -- Any_Fixed is legal in a real context only if a specific fixed-
2969 -- point type is imposed. If Norman Cohen can be confused by this,
2970 -- it deserves a separate message.
2972 if Typ = Any_Real
2973 and then Expr_Type = Any_Fixed
2974 then
2975 Error_Msg_N ("illegal context for mixed mode operation", N);
2976 Set_Etype (N, Universal_Real);
2977 Ctx_Type := Universal_Real;
2978 end if;
2979 end if;
2981 -- A user-defined operator is transformed into a function call at
2982 -- this point, so that further processing knows that operators are
2983 -- really operators (i.e. are predefined operators). User-defined
2984 -- operators that are intrinsic are just renamings of the predefined
2985 -- ones, and need not be turned into calls either, but if they rename
2986 -- a different operator, we must transform the node accordingly.
2987 -- Instantiations of Unchecked_Conversion are intrinsic but are
2988 -- treated as functions, even if given an operator designator.
2990 if Nkind (N) in N_Op
2991 and then Present (Entity (N))
2992 and then Ekind (Entity (N)) /= E_Operator
2993 then
2995 if not Is_Predefined_Op (Entity (N)) then
2996 Rewrite_Operator_As_Call (N, Entity (N));
2998 elsif Present (Alias (Entity (N)))
2999 and then
3000 Nkind (Parent (Parent (Entity (N)))) =
3001 N_Subprogram_Renaming_Declaration
3002 then
3003 Rewrite_Renamed_Operator (N, Alias (Entity (N)), Typ);
3005 -- If the node is rewritten, it will be fully resolved in
3006 -- Rewrite_Renamed_Operator.
3008 if Analyzed (N) then
3009 return;
3010 end if;
3011 end if;
3012 end if;
3014 case N_Subexpr'(Nkind (N)) is
3016 when N_Aggregate => Resolve_Aggregate (N, Ctx_Type);
3018 when N_Allocator => Resolve_Allocator (N, Ctx_Type);
3020 when N_Short_Circuit
3021 => Resolve_Short_Circuit (N, Ctx_Type);
3023 when N_Attribute_Reference
3024 => Resolve_Attribute (N, Ctx_Type);
3026 when N_Case_Expression
3027 => Resolve_Case_Expression (N, Ctx_Type);
3029 when N_Character_Literal
3030 => Resolve_Character_Literal (N, Ctx_Type);
3032 when N_Expanded_Name
3033 => Resolve_Entity_Name (N, Ctx_Type);
3035 when N_Explicit_Dereference
3036 => Resolve_Explicit_Dereference (N, Ctx_Type);
3038 when N_Expression_With_Actions
3039 => Resolve_Expression_With_Actions (N, Ctx_Type);
3041 when N_Extension_Aggregate
3042 => Resolve_Extension_Aggregate (N, Ctx_Type);
3044 when N_Function_Call
3045 => Resolve_Call (N, Ctx_Type);
3047 when N_Identifier
3048 => Resolve_Entity_Name (N, Ctx_Type);
3050 when N_If_Expression
3051 => Resolve_If_Expression (N, Ctx_Type);
3053 when N_Indexed_Component
3054 => Resolve_Indexed_Component (N, Ctx_Type);
3056 when N_Integer_Literal
3057 => Resolve_Integer_Literal (N, Ctx_Type);
3059 when N_Membership_Test
3060 => Resolve_Membership_Op (N, Ctx_Type);
3062 when N_Null => Resolve_Null (N, Ctx_Type);
3064 when N_Op_And | N_Op_Or | N_Op_Xor
3065 => Resolve_Logical_Op (N, Ctx_Type);
3067 when N_Op_Eq | N_Op_Ne
3068 => Resolve_Equality_Op (N, Ctx_Type);
3070 when N_Op_Lt | N_Op_Le | N_Op_Gt | N_Op_Ge
3071 => Resolve_Comparison_Op (N, Ctx_Type);
3073 when N_Op_Not => Resolve_Op_Not (N, Ctx_Type);
3075 when N_Op_Add | N_Op_Subtract | N_Op_Multiply |
3076 N_Op_Divide | N_Op_Mod | N_Op_Rem
3078 => Resolve_Arithmetic_Op (N, Ctx_Type);
3080 when N_Op_Concat => Resolve_Op_Concat (N, Ctx_Type);
3082 when N_Op_Expon => Resolve_Op_Expon (N, Ctx_Type);
3084 when N_Op_Plus | N_Op_Minus | N_Op_Abs
3085 => Resolve_Unary_Op (N, Ctx_Type);
3087 when N_Op_Shift => Resolve_Shift (N, Ctx_Type);
3089 when N_Procedure_Call_Statement
3090 => Resolve_Call (N, Ctx_Type);
3092 when N_Operator_Symbol
3093 => Resolve_Operator_Symbol (N, Ctx_Type);
3095 when N_Qualified_Expression
3096 => Resolve_Qualified_Expression (N, Ctx_Type);
3098 -- Why is the following null, needs a comment ???
3100 when N_Quantified_Expression
3101 => null;
3103 when N_Raise_Expression
3104 => Resolve_Raise_Expression (N, Ctx_Type);
3106 when N_Raise_xxx_Error
3107 => Set_Etype (N, Ctx_Type);
3109 when N_Range => Resolve_Range (N, Ctx_Type);
3111 when N_Real_Literal
3112 => Resolve_Real_Literal (N, Ctx_Type);
3114 when N_Reference => Resolve_Reference (N, Ctx_Type);
3116 when N_Selected_Component
3117 => Resolve_Selected_Component (N, Ctx_Type);
3119 when N_Slice => Resolve_Slice (N, Ctx_Type);
3121 when N_String_Literal
3122 => Resolve_String_Literal (N, Ctx_Type);
3124 when N_Type_Conversion
3125 => Resolve_Type_Conversion (N, Ctx_Type);
3127 when N_Unchecked_Expression =>
3128 Resolve_Unchecked_Expression (N, Ctx_Type);
3130 when N_Unchecked_Type_Conversion =>
3131 Resolve_Unchecked_Type_Conversion (N, Ctx_Type);
3132 end case;
3134 -- Ada 2012 (AI05-0149): Apply an (implicit) conversion to an
3135 -- expression of an anonymous access type that occurs in the context
3136 -- of a named general access type, except when the expression is that
3137 -- of a membership test. This ensures proper legality checking in
3138 -- terms of allowed conversions (expressions that would be illegal to
3139 -- convert implicitly are allowed in membership tests).
3141 if Ada_Version >= Ada_2012
3142 and then Ekind (Ctx_Type) = E_General_Access_Type
3143 and then Ekind (Etype (N)) = E_Anonymous_Access_Type
3144 and then Nkind (Parent (N)) not in N_Membership_Test
3145 then
3146 Rewrite (N, Convert_To (Ctx_Type, Relocate_Node (N)));
3147 Analyze_And_Resolve (N, Ctx_Type);
3148 end if;
3150 -- If the subexpression was replaced by a non-subexpression, then
3151 -- all we do is to expand it. The only legitimate case we know of
3152 -- is converting procedure call statement to entry call statements,
3153 -- but there may be others, so we are making this test general.
3155 if Nkind (N) not in N_Subexpr then
3156 Debug_A_Exit ("resolving ", N, " (done)");
3157 Expand (N);
3158 return;
3159 end if;
3161 -- The expression is definitely NOT overloaded at this point, so
3162 -- we reset the Is_Overloaded flag to avoid any confusion when
3163 -- reanalyzing the node.
3165 Set_Is_Overloaded (N, False);
3167 -- Freeze expression type, entity if it is a name, and designated
3168 -- type if it is an allocator (RM 13.14(10,11,13)).
3170 -- Now that the resolution of the type of the node is complete, and
3171 -- we did not detect an error, we can expand this node. We skip the
3172 -- expand call if we are in a default expression, see section
3173 -- "Handling of Default Expressions" in Sem spec.
3175 Debug_A_Exit ("resolving ", N, " (done)");
3177 -- We unconditionally freeze the expression, even if we are in
3178 -- default expression mode (the Freeze_Expression routine tests this
3179 -- flag and only freezes static types if it is set).
3181 -- Ada 2012 (AI05-177): The declaration of an expression function
3182 -- does not cause freezing, but we never reach here in that case.
3183 -- Here we are resolving the corresponding expanded body, so we do
3184 -- need to perform normal freezing.
3186 Freeze_Expression (N);
3188 -- Now we can do the expansion
3190 Expand (N);
3191 end if;
3192 end Resolve;
3194 -------------
3195 -- Resolve --
3196 -------------
3198 -- Version with check(s) suppressed
3200 procedure Resolve (N : Node_Id; Typ : Entity_Id; Suppress : Check_Id) is
3201 begin
3202 if Suppress = All_Checks then
3203 declare
3204 Sva : constant Suppress_Array := Scope_Suppress.Suppress;
3205 begin
3206 Scope_Suppress.Suppress := (others => True);
3207 Resolve (N, Typ);
3208 Scope_Suppress.Suppress := Sva;
3209 end;
3211 else
3212 declare
3213 Svg : constant Boolean := Scope_Suppress.Suppress (Suppress);
3214 begin
3215 Scope_Suppress.Suppress (Suppress) := True;
3216 Resolve (N, Typ);
3217 Scope_Suppress.Suppress (Suppress) := Svg;
3218 end;
3219 end if;
3220 end Resolve;
3222 -------------
3223 -- Resolve --
3224 -------------
3226 -- Version with implicit type
3228 procedure Resolve (N : Node_Id) is
3229 begin
3230 Resolve (N, Etype (N));
3231 end Resolve;
3233 ---------------------
3234 -- Resolve_Actuals --
3235 ---------------------
3237 procedure Resolve_Actuals (N : Node_Id; Nam : Entity_Id) is
3238 Loc : constant Source_Ptr := Sloc (N);
3239 A : Node_Id;
3240 A_Id : Entity_Id;
3241 A_Typ : Entity_Id;
3242 F : Entity_Id;
3243 F_Typ : Entity_Id;
3244 Prev : Node_Id := Empty;
3245 Orig_A : Node_Id;
3247 procedure Check_Aliased_Parameter;
3248 -- Check rules on aliased parameters and related accessibility rules
3249 -- in (RM 3.10.2 (10.2-10.4)).
3251 procedure Check_Argument_Order;
3252 -- Performs a check for the case where the actuals are all simple
3253 -- identifiers that correspond to the formal names, but in the wrong
3254 -- order, which is considered suspicious and cause for a warning.
3256 procedure Check_Prefixed_Call;
3257 -- If the original node is an overloaded call in prefix notation,
3258 -- insert an 'Access or a dereference as needed over the first actual.
3259 -- Try_Object_Operation has already verified that there is a valid
3260 -- interpretation, but the form of the actual can only be determined
3261 -- once the primitive operation is identified.
3263 procedure Insert_Default;
3264 -- If the actual is missing in a call, insert in the actuals list
3265 -- an instance of the default expression. The insertion is always
3266 -- a named association.
3268 procedure Property_Error
3269 (Var : Node_Id;
3270 Var_Id : Entity_Id;
3271 Prop_Nam : Name_Id);
3272 -- Emit an error concerning variable Var with entity Var_Id that has
3273 -- enabled property Prop_Nam when it acts as an actual parameter in a
3274 -- call and the corresponding formal parameter is of mode IN.
3276 function Same_Ancestor (T1, T2 : Entity_Id) return Boolean;
3277 -- Check whether T1 and T2, or their full views, are derived from a
3278 -- common type. Used to enforce the restrictions on array conversions
3279 -- of AI95-00246.
3281 function Static_Concatenation (N : Node_Id) return Boolean;
3282 -- Predicate to determine whether an actual that is a concatenation
3283 -- will be evaluated statically and does not need a transient scope.
3284 -- This must be determined before the actual is resolved and expanded
3285 -- because if needed the transient scope must be introduced earlier.
3287 ------------------------------
3288 -- Check_Aliased_Parameter --
3289 ------------------------------
3291 procedure Check_Aliased_Parameter is
3292 Nominal_Subt : Entity_Id;
3294 begin
3295 if Is_Aliased (F) then
3296 if Is_Tagged_Type (A_Typ) then
3297 null;
3299 elsif Is_Aliased_View (A) then
3300 if Is_Constr_Subt_For_U_Nominal (A_Typ) then
3301 Nominal_Subt := Base_Type (A_Typ);
3302 else
3303 Nominal_Subt := A_Typ;
3304 end if;
3306 if Subtypes_Statically_Match (F_Typ, Nominal_Subt) then
3307 null;
3309 -- In a generic body assume the worst for generic formals:
3310 -- they can have a constrained partial view (AI05-041).
3312 elsif Has_Discriminants (F_Typ)
3313 and then not Is_Constrained (F_Typ)
3314 and then not Has_Constrained_Partial_View (F_Typ)
3315 and then not Is_Generic_Type (F_Typ)
3316 then
3317 null;
3319 else
3320 Error_Msg_NE ("untagged actual does not match "
3321 & "aliased formal&", A, F);
3322 end if;
3324 else
3325 Error_Msg_NE ("actual for aliased formal& must be "
3326 & "aliased object", A, F);
3327 end if;
3329 if Ekind (Nam) = E_Procedure then
3330 null;
3332 elsif Ekind (Etype (Nam)) = E_Anonymous_Access_Type then
3333 if Nkind (Parent (N)) = N_Type_Conversion
3334 and then Type_Access_Level (Etype (Parent (N))) <
3335 Object_Access_Level (A)
3336 then
3337 Error_Msg_N ("aliased actual has wrong accessibility", A);
3338 end if;
3340 elsif Nkind (Parent (N)) = N_Qualified_Expression
3341 and then Nkind (Parent (Parent (N))) = N_Allocator
3342 and then Type_Access_Level (Etype (Parent (Parent (N)))) <
3343 Object_Access_Level (A)
3344 then
3345 Error_Msg_N
3346 ("aliased actual in allocator has wrong accessibility", A);
3347 end if;
3348 end if;
3349 end Check_Aliased_Parameter;
3351 --------------------------
3352 -- Check_Argument_Order --
3353 --------------------------
3355 procedure Check_Argument_Order is
3356 begin
3357 -- Nothing to do if no parameters, or original node is neither a
3358 -- function call nor a procedure call statement (happens in the
3359 -- operator-transformed-to-function call case), or the call does
3360 -- not come from source, or this warning is off.
3362 if not Warn_On_Parameter_Order
3363 or else No (Parameter_Associations (N))
3364 or else Nkind (Original_Node (N)) not in N_Subprogram_Call
3365 or else not Comes_From_Source (N)
3366 then
3367 return;
3368 end if;
3370 declare
3371 Nargs : constant Nat := List_Length (Parameter_Associations (N));
3373 begin
3374 -- Nothing to do if only one parameter
3376 if Nargs < 2 then
3377 return;
3378 end if;
3380 -- Here if at least two arguments
3382 declare
3383 Actuals : array (1 .. Nargs) of Node_Id;
3384 Actual : Node_Id;
3385 Formal : Node_Id;
3387 Wrong_Order : Boolean := False;
3388 -- Set True if an out of order case is found
3390 begin
3391 -- Collect identifier names of actuals, fail if any actual is
3392 -- not a simple identifier, and record max length of name.
3394 Actual := First (Parameter_Associations (N));
3395 for J in Actuals'Range loop
3396 if Nkind (Actual) /= N_Identifier then
3397 return;
3398 else
3399 Actuals (J) := Actual;
3400 Next (Actual);
3401 end if;
3402 end loop;
3404 -- If we got this far, all actuals are identifiers and the list
3405 -- of their names is stored in the Actuals array.
3407 Formal := First_Formal (Nam);
3408 for J in Actuals'Range loop
3410 -- If we ran out of formals, that's odd, probably an error
3411 -- which will be detected elsewhere, but abandon the search.
3413 if No (Formal) then
3414 return;
3415 end if;
3417 -- If name matches and is in order OK
3419 if Chars (Formal) = Chars (Actuals (J)) then
3420 null;
3422 else
3423 -- If no match, see if it is elsewhere in list and if so
3424 -- flag potential wrong order if type is compatible.
3426 for K in Actuals'Range loop
3427 if Chars (Formal) = Chars (Actuals (K))
3428 and then
3429 Has_Compatible_Type (Actuals (K), Etype (Formal))
3430 then
3431 Wrong_Order := True;
3432 goto Continue;
3433 end if;
3434 end loop;
3436 -- No match
3438 return;
3439 end if;
3441 <<Continue>> Next_Formal (Formal);
3442 end loop;
3444 -- If Formals left over, also probably an error, skip warning
3446 if Present (Formal) then
3447 return;
3448 end if;
3450 -- Here we give the warning if something was out of order
3452 if Wrong_Order then
3453 Error_Msg_N
3454 ("?P?actuals for this call may be in wrong order", N);
3455 end if;
3456 end;
3457 end;
3458 end Check_Argument_Order;
3460 -------------------------
3461 -- Check_Prefixed_Call --
3462 -------------------------
3464 procedure Check_Prefixed_Call is
3465 Act : constant Node_Id := First_Actual (N);
3466 A_Type : constant Entity_Id := Etype (Act);
3467 F_Type : constant Entity_Id := Etype (First_Formal (Nam));
3468 Orig : constant Node_Id := Original_Node (N);
3469 New_A : Node_Id;
3471 begin
3472 -- Check whether the call is a prefixed call, with or without
3473 -- additional actuals.
3475 if Nkind (Orig) = N_Selected_Component
3476 or else
3477 (Nkind (Orig) = N_Indexed_Component
3478 and then Nkind (Prefix (Orig)) = N_Selected_Component
3479 and then Is_Entity_Name (Prefix (Prefix (Orig)))
3480 and then Is_Entity_Name (Act)
3481 and then Chars (Act) = Chars (Prefix (Prefix (Orig))))
3482 then
3483 if Is_Access_Type (A_Type)
3484 and then not Is_Access_Type (F_Type)
3485 then
3486 -- Introduce dereference on object in prefix
3488 New_A :=
3489 Make_Explicit_Dereference (Sloc (Act),
3490 Prefix => Relocate_Node (Act));
3491 Rewrite (Act, New_A);
3492 Analyze (Act);
3494 elsif Is_Access_Type (F_Type)
3495 and then not Is_Access_Type (A_Type)
3496 then
3497 -- Introduce an implicit 'Access in prefix
3499 if not Is_Aliased_View (Act) then
3500 Error_Msg_NE
3501 ("object in prefixed call to& must be aliased "
3502 & "(RM 4.1.3 (13 1/2))",
3503 Prefix (Act), Nam);
3504 end if;
3506 Rewrite (Act,
3507 Make_Attribute_Reference (Loc,
3508 Attribute_Name => Name_Access,
3509 Prefix => Relocate_Node (Act)));
3510 end if;
3512 Analyze (Act);
3513 end if;
3514 end Check_Prefixed_Call;
3516 --------------------
3517 -- Insert_Default --
3518 --------------------
3520 procedure Insert_Default is
3521 Actval : Node_Id;
3522 Assoc : Node_Id;
3524 begin
3525 -- Missing argument in call, nothing to insert
3527 if No (Default_Value (F)) then
3528 return;
3530 else
3531 -- Note that we do a full New_Copy_Tree, so that any associated
3532 -- Itypes are properly copied. This may not be needed any more,
3533 -- but it does no harm as a safety measure. Defaults of a generic
3534 -- formal may be out of bounds of the corresponding actual (see
3535 -- cc1311b) and an additional check may be required.
3537 Actval :=
3538 New_Copy_Tree
3539 (Default_Value (F),
3540 New_Scope => Current_Scope,
3541 New_Sloc => Loc);
3543 if Is_Concurrent_Type (Scope (Nam))
3544 and then Has_Discriminants (Scope (Nam))
3545 then
3546 Replace_Actual_Discriminants (N, Actval);
3547 end if;
3549 if Is_Overloadable (Nam)
3550 and then Present (Alias (Nam))
3551 then
3552 if Base_Type (Etype (F)) /= Base_Type (Etype (Actval))
3553 and then not Is_Tagged_Type (Etype (F))
3554 then
3555 -- If default is a real literal, do not introduce a
3556 -- conversion whose effect may depend on the run-time
3557 -- size of universal real.
3559 if Nkind (Actval) = N_Real_Literal then
3560 Set_Etype (Actval, Base_Type (Etype (F)));
3561 else
3562 Actval := Unchecked_Convert_To (Etype (F), Actval);
3563 end if;
3564 end if;
3566 if Is_Scalar_Type (Etype (F)) then
3567 Enable_Range_Check (Actval);
3568 end if;
3570 Set_Parent (Actval, N);
3572 -- Resolve aggregates with their base type, to avoid scope
3573 -- anomalies: the subtype was first built in the subprogram
3574 -- declaration, and the current call may be nested.
3576 if Nkind (Actval) = N_Aggregate then
3577 Analyze_And_Resolve (Actval, Etype (F));
3578 else
3579 Analyze_And_Resolve (Actval, Etype (Actval));
3580 end if;
3582 else
3583 Set_Parent (Actval, N);
3585 -- See note above concerning aggregates
3587 if Nkind (Actval) = N_Aggregate
3588 and then Has_Discriminants (Etype (Actval))
3589 then
3590 Analyze_And_Resolve (Actval, Base_Type (Etype (Actval)));
3592 -- Resolve entities with their own type, which may differ from
3593 -- the type of a reference in a generic context (the view
3594 -- swapping mechanism did not anticipate the re-analysis of
3595 -- default values in calls).
3597 elsif Is_Entity_Name (Actval) then
3598 Analyze_And_Resolve (Actval, Etype (Entity (Actval)));
3600 else
3601 Analyze_And_Resolve (Actval, Etype (Actval));
3602 end if;
3603 end if;
3605 -- If default is a tag indeterminate function call, propagate tag
3606 -- to obtain proper dispatching.
3608 if Is_Controlling_Formal (F)
3609 and then Nkind (Default_Value (F)) = N_Function_Call
3610 then
3611 Set_Is_Controlling_Actual (Actval);
3612 end if;
3614 end if;
3616 -- If the default expression raises constraint error, then just
3617 -- silently replace it with an N_Raise_Constraint_Error node, since
3618 -- we already gave the warning on the subprogram spec. If node is
3619 -- already a Raise_Constraint_Error leave as is, to prevent loops in
3620 -- the warnings removal machinery.
3622 if Raises_Constraint_Error (Actval)
3623 and then Nkind (Actval) /= N_Raise_Constraint_Error
3624 then
3625 Rewrite (Actval,
3626 Make_Raise_Constraint_Error (Loc,
3627 Reason => CE_Range_Check_Failed));
3628 Set_Raises_Constraint_Error (Actval);
3629 Set_Etype (Actval, Etype (F));
3630 end if;
3632 Assoc :=
3633 Make_Parameter_Association (Loc,
3634 Explicit_Actual_Parameter => Actval,
3635 Selector_Name => Make_Identifier (Loc, Chars (F)));
3637 -- Case of insertion is first named actual
3639 if No (Prev) or else
3640 Nkind (Parent (Prev)) /= N_Parameter_Association
3641 then
3642 Set_Next_Named_Actual (Assoc, First_Named_Actual (N));
3643 Set_First_Named_Actual (N, Actval);
3645 if No (Prev) then
3646 if No (Parameter_Associations (N)) then
3647 Set_Parameter_Associations (N, New_List (Assoc));
3648 else
3649 Append (Assoc, Parameter_Associations (N));
3650 end if;
3652 else
3653 Insert_After (Prev, Assoc);
3654 end if;
3656 -- Case of insertion is not first named actual
3658 else
3659 Set_Next_Named_Actual
3660 (Assoc, Next_Named_Actual (Parent (Prev)));
3661 Set_Next_Named_Actual (Parent (Prev), Actval);
3662 Append (Assoc, Parameter_Associations (N));
3663 end if;
3665 Mark_Rewrite_Insertion (Assoc);
3666 Mark_Rewrite_Insertion (Actval);
3668 Prev := Actval;
3669 end Insert_Default;
3671 --------------------
3672 -- Property_Error --
3673 --------------------
3675 procedure Property_Error
3676 (Var : Node_Id;
3677 Var_Id : Entity_Id;
3678 Prop_Nam : Name_Id)
3680 begin
3681 Error_Msg_Name_1 := Prop_Nam;
3682 Error_Msg_NE
3683 ("external variable & with enabled property % cannot appear as "
3684 & "actual in procedure call (SPARK RM 7.1.3(11))", Var, Var_Id);
3685 Error_Msg_N ("\\corresponding formal parameter has mode In", Var);
3686 end Property_Error;
3688 -------------------
3689 -- Same_Ancestor --
3690 -------------------
3692 function Same_Ancestor (T1, T2 : Entity_Id) return Boolean is
3693 FT1 : Entity_Id := T1;
3694 FT2 : Entity_Id := T2;
3696 begin
3697 if Is_Private_Type (T1)
3698 and then Present (Full_View (T1))
3699 then
3700 FT1 := Full_View (T1);
3701 end if;
3703 if Is_Private_Type (T2)
3704 and then Present (Full_View (T2))
3705 then
3706 FT2 := Full_View (T2);
3707 end if;
3709 return Root_Type (Base_Type (FT1)) = Root_Type (Base_Type (FT2));
3710 end Same_Ancestor;
3712 --------------------------
3713 -- Static_Concatenation --
3714 --------------------------
3716 function Static_Concatenation (N : Node_Id) return Boolean is
3717 begin
3718 case Nkind (N) is
3719 when N_String_Literal =>
3720 return True;
3722 when N_Op_Concat =>
3724 -- Concatenation is static when both operands are static and
3725 -- the concatenation operator is a predefined one.
3727 return Scope (Entity (N)) = Standard_Standard
3728 and then
3729 Static_Concatenation (Left_Opnd (N))
3730 and then
3731 Static_Concatenation (Right_Opnd (N));
3733 when others =>
3734 if Is_Entity_Name (N) then
3735 declare
3736 Ent : constant Entity_Id := Entity (N);
3737 begin
3738 return Ekind (Ent) = E_Constant
3739 and then Present (Constant_Value (Ent))
3740 and then
3741 Is_OK_Static_Expression (Constant_Value (Ent));
3742 end;
3744 else
3745 return False;
3746 end if;
3747 end case;
3748 end Static_Concatenation;
3750 -- Start of processing for Resolve_Actuals
3752 begin
3753 Check_Argument_Order;
3754 Check_Function_Writable_Actuals (N);
3756 if Present (First_Actual (N)) then
3757 Check_Prefixed_Call;
3758 end if;
3760 A := First_Actual (N);
3761 F := First_Formal (Nam);
3762 while Present (F) loop
3763 if No (A) and then Needs_No_Actuals (Nam) then
3764 null;
3766 -- If we have an error in any actual or formal, indicated by a type
3767 -- of Any_Type, then abandon resolution attempt, and set result type
3768 -- to Any_Type. Skip this if the actual is a Raise_Expression, whose
3769 -- type is imposed from context.
3771 elsif (Present (A) and then Etype (A) = Any_Type)
3772 or else Etype (F) = Any_Type
3773 then
3774 if Nkind (A) /= N_Raise_Expression then
3775 Set_Etype (N, Any_Type);
3776 return;
3777 end if;
3778 end if;
3780 -- Case where actual is present
3782 -- If the actual is an entity, generate a reference to it now. We
3783 -- do this before the actual is resolved, because a formal of some
3784 -- protected subprogram, or a task discriminant, will be rewritten
3785 -- during expansion, and the source entity reference may be lost.
3787 if Present (A)
3788 and then Is_Entity_Name (A)
3789 and then Comes_From_Source (N)
3790 then
3791 Orig_A := Entity (A);
3793 if Present (Orig_A) then
3794 if Is_Formal (Orig_A)
3795 and then Ekind (F) /= E_In_Parameter
3796 then
3797 Generate_Reference (Orig_A, A, 'm');
3799 elsif not Is_Overloaded (A) then
3800 if Ekind (F) /= E_Out_Parameter then
3801 Generate_Reference (Orig_A, A);
3803 -- RM 6.4.1(12): For an out parameter that is passed by
3804 -- copy, the formal parameter object is created, and:
3806 -- * For an access type, the formal parameter is initialized
3807 -- from the value of the actual, without checking that the
3808 -- value satisfies any constraint, any predicate, or any
3809 -- exclusion of the null value.
3811 -- * For a scalar type that has the Default_Value aspect
3812 -- specified, the formal parameter is initialized from the
3813 -- value of the actual, without checking that the value
3814 -- satisfies any constraint or any predicate.
3815 -- I do not understand why this case is included??? this is
3816 -- not a case where an OUT parameter is treated as IN OUT.
3818 -- * For a composite type with discriminants or that has
3819 -- implicit initial values for any subcomponents, the
3820 -- behavior is as for an in out parameter passed by copy.
3822 -- Hence for these cases we generate the read reference now
3823 -- (the write reference will be generated later by
3824 -- Note_Possible_Modification).
3826 elsif Is_By_Copy_Type (Etype (F))
3827 and then
3828 (Is_Access_Type (Etype (F))
3829 or else
3830 (Is_Scalar_Type (Etype (F))
3831 and then
3832 Present (Default_Aspect_Value (Etype (F))))
3833 or else
3834 (Is_Composite_Type (Etype (F))
3835 and then (Has_Discriminants (Etype (F))
3836 or else Is_Partially_Initialized_Type
3837 (Etype (F)))))
3838 then
3839 Generate_Reference (Orig_A, A);
3840 end if;
3841 end if;
3842 end if;
3843 end if;
3845 if Present (A)
3846 and then (Nkind (Parent (A)) /= N_Parameter_Association
3847 or else Chars (Selector_Name (Parent (A))) = Chars (F))
3848 then
3849 -- If style checking mode on, check match of formal name
3851 if Style_Check then
3852 if Nkind (Parent (A)) = N_Parameter_Association then
3853 Check_Identifier (Selector_Name (Parent (A)), F);
3854 end if;
3855 end if;
3857 -- If the formal is Out or In_Out, do not resolve and expand the
3858 -- conversion, because it is subsequently expanded into explicit
3859 -- temporaries and assignments. However, the object of the
3860 -- conversion can be resolved. An exception is the case of tagged
3861 -- type conversion with a class-wide actual. In that case we want
3862 -- the tag check to occur and no temporary will be needed (no
3863 -- representation change can occur) and the parameter is passed by
3864 -- reference, so we go ahead and resolve the type conversion.
3865 -- Another exception is the case of reference to component or
3866 -- subcomponent of a bit-packed array, in which case we want to
3867 -- defer expansion to the point the in and out assignments are
3868 -- performed.
3870 if Ekind (F) /= E_In_Parameter
3871 and then Nkind (A) = N_Type_Conversion
3872 and then not Is_Class_Wide_Type (Etype (Expression (A)))
3873 then
3874 if Ekind (F) = E_In_Out_Parameter
3875 and then Is_Array_Type (Etype (F))
3876 then
3877 -- In a view conversion, the conversion must be legal in
3878 -- both directions, and thus both component types must be
3879 -- aliased, or neither (4.6 (8)).
3881 -- The extra rule in 4.6 (24.9.2) seems unduly restrictive:
3882 -- the privacy requirement should not apply to generic
3883 -- types, and should be checked in an instance. ARG query
3884 -- is in order ???
3886 if Has_Aliased_Components (Etype (Expression (A))) /=
3887 Has_Aliased_Components (Etype (F))
3888 then
3889 Error_Msg_N
3890 ("both component types in a view conversion must be"
3891 & " aliased, or neither", A);
3893 -- Comment here??? what set of cases???
3895 elsif
3896 not Same_Ancestor (Etype (F), Etype (Expression (A)))
3897 then
3898 -- Check view conv between unrelated by ref array types
3900 if Is_By_Reference_Type (Etype (F))
3901 or else Is_By_Reference_Type (Etype (Expression (A)))
3902 then
3903 Error_Msg_N
3904 ("view conversion between unrelated by reference "
3905 & "array types not allowed (\'A'I-00246)", A);
3907 -- In Ada 2005 mode, check view conversion component
3908 -- type cannot be private, tagged, or volatile. Note
3909 -- that we only apply this to source conversions. The
3910 -- generated code can contain conversions which are
3911 -- not subject to this test, and we cannot extract the
3912 -- component type in such cases since it is not present.
3914 elsif Comes_From_Source (A)
3915 and then Ada_Version >= Ada_2005
3916 then
3917 declare
3918 Comp_Type : constant Entity_Id :=
3919 Component_Type
3920 (Etype (Expression (A)));
3921 begin
3922 if (Is_Private_Type (Comp_Type)
3923 and then not Is_Generic_Type (Comp_Type))
3924 or else Is_Tagged_Type (Comp_Type)
3925 or else Is_Volatile (Comp_Type)
3926 then
3927 Error_Msg_N
3928 ("component type of a view conversion cannot"
3929 & " be private, tagged, or volatile"
3930 & " (RM 4.6 (24))",
3931 Expression (A));
3932 end if;
3933 end;
3934 end if;
3935 end if;
3936 end if;
3938 -- Resolve expression if conversion is all OK
3940 if (Conversion_OK (A)
3941 or else Valid_Conversion (A, Etype (A), Expression (A)))
3942 and then not Is_Ref_To_Bit_Packed_Array (Expression (A))
3943 then
3944 Resolve (Expression (A));
3945 end if;
3947 -- If the actual is a function call that returns a limited
3948 -- unconstrained object that needs finalization, create a
3949 -- transient scope for it, so that it can receive the proper
3950 -- finalization list.
3952 elsif Nkind (A) = N_Function_Call
3953 and then Is_Limited_Record (Etype (F))
3954 and then not Is_Constrained (Etype (F))
3955 and then Expander_Active
3956 and then (Is_Controlled (Etype (F)) or else Has_Task (Etype (F)))
3957 then
3958 Establish_Transient_Scope (A, Sec_Stack => False);
3959 Resolve (A, Etype (F));
3961 -- A small optimization: if one of the actuals is a concatenation
3962 -- create a block around a procedure call to recover stack space.
3963 -- This alleviates stack usage when several procedure calls in
3964 -- the same statement list use concatenation. We do not perform
3965 -- this wrapping for code statements, where the argument is a
3966 -- static string, and we want to preserve warnings involving
3967 -- sequences of such statements.
3969 elsif Nkind (A) = N_Op_Concat
3970 and then Nkind (N) = N_Procedure_Call_Statement
3971 and then Expander_Active
3972 and then
3973 not (Is_Intrinsic_Subprogram (Nam)
3974 and then Chars (Nam) = Name_Asm)
3975 and then not Static_Concatenation (A)
3976 then
3977 Establish_Transient_Scope (A, Sec_Stack => False);
3978 Resolve (A, Etype (F));
3980 else
3981 if Nkind (A) = N_Type_Conversion
3982 and then Is_Array_Type (Etype (F))
3983 and then not Same_Ancestor (Etype (F), Etype (Expression (A)))
3984 and then
3985 (Is_Limited_Type (Etype (F))
3986 or else Is_Limited_Type (Etype (Expression (A))))
3987 then
3988 Error_Msg_N
3989 ("conversion between unrelated limited array types "
3990 & "not allowed ('A'I-00246)", A);
3992 if Is_Limited_Type (Etype (F)) then
3993 Explain_Limited_Type (Etype (F), A);
3994 end if;
3996 if Is_Limited_Type (Etype (Expression (A))) then
3997 Explain_Limited_Type (Etype (Expression (A)), A);
3998 end if;
3999 end if;
4001 -- (Ada 2005: AI-251): If the actual is an allocator whose
4002 -- directly designated type is a class-wide interface, we build
4003 -- an anonymous access type to use it as the type of the
4004 -- allocator. Later, when the subprogram call is expanded, if
4005 -- the interface has a secondary dispatch table the expander
4006 -- will add a type conversion to force the correct displacement
4007 -- of the pointer.
4009 if Nkind (A) = N_Allocator then
4010 declare
4011 DDT : constant Entity_Id :=
4012 Directly_Designated_Type (Base_Type (Etype (F)));
4014 New_Itype : Entity_Id;
4016 begin
4017 if Is_Class_Wide_Type (DDT)
4018 and then Is_Interface (DDT)
4019 then
4020 New_Itype := Create_Itype (E_Anonymous_Access_Type, A);
4021 Set_Etype (New_Itype, Etype (A));
4022 Set_Directly_Designated_Type
4023 (New_Itype, Directly_Designated_Type (Etype (A)));
4024 Set_Etype (A, New_Itype);
4025 end if;
4027 -- Ada 2005, AI-162:If the actual is an allocator, the
4028 -- innermost enclosing statement is the master of the
4029 -- created object. This needs to be done with expansion
4030 -- enabled only, otherwise the transient scope will not
4031 -- be removed in the expansion of the wrapped construct.
4033 if (Is_Controlled (DDT) or else Has_Task (DDT))
4034 and then Expander_Active
4035 then
4036 Establish_Transient_Scope (A, Sec_Stack => False);
4037 end if;
4038 end;
4040 if Ekind (Etype (F)) = E_Anonymous_Access_Type then
4041 Check_Restriction (No_Access_Parameter_Allocators, A);
4042 end if;
4043 end if;
4045 -- (Ada 2005): The call may be to a primitive operation of a
4046 -- tagged synchronized type, declared outside of the type. In
4047 -- this case the controlling actual must be converted to its
4048 -- corresponding record type, which is the formal type. The
4049 -- actual may be a subtype, either because of a constraint or
4050 -- because it is a generic actual, so use base type to locate
4051 -- concurrent type.
4053 F_Typ := Base_Type (Etype (F));
4055 if Is_Tagged_Type (F_Typ)
4056 and then (Is_Concurrent_Type (F_Typ)
4057 or else Is_Concurrent_Record_Type (F_Typ))
4058 then
4059 -- If the actual is overloaded, look for an interpretation
4060 -- that has a synchronized type.
4062 if not Is_Overloaded (A) then
4063 A_Typ := Base_Type (Etype (A));
4065 else
4066 declare
4067 Index : Interp_Index;
4068 It : Interp;
4070 begin
4071 Get_First_Interp (A, Index, It);
4072 while Present (It.Typ) loop
4073 if Is_Concurrent_Type (It.Typ)
4074 or else Is_Concurrent_Record_Type (It.Typ)
4075 then
4076 A_Typ := Base_Type (It.Typ);
4077 exit;
4078 end if;
4080 Get_Next_Interp (Index, It);
4081 end loop;
4082 end;
4083 end if;
4085 declare
4086 Full_A_Typ : Entity_Id;
4088 begin
4089 if Present (Full_View (A_Typ)) then
4090 Full_A_Typ := Base_Type (Full_View (A_Typ));
4091 else
4092 Full_A_Typ := A_Typ;
4093 end if;
4095 -- Tagged synchronized type (case 1): the actual is a
4096 -- concurrent type.
4098 if Is_Concurrent_Type (A_Typ)
4099 and then Corresponding_Record_Type (A_Typ) = F_Typ
4100 then
4101 Rewrite (A,
4102 Unchecked_Convert_To
4103 (Corresponding_Record_Type (A_Typ), A));
4104 Resolve (A, Etype (F));
4106 -- Tagged synchronized type (case 2): the formal is a
4107 -- concurrent type.
4109 elsif Ekind (Full_A_Typ) = E_Record_Type
4110 and then Present
4111 (Corresponding_Concurrent_Type (Full_A_Typ))
4112 and then Is_Concurrent_Type (F_Typ)
4113 and then Present (Corresponding_Record_Type (F_Typ))
4114 and then Full_A_Typ = Corresponding_Record_Type (F_Typ)
4115 then
4116 Resolve (A, Corresponding_Record_Type (F_Typ));
4118 -- Common case
4120 else
4121 Resolve (A, Etype (F));
4122 end if;
4123 end;
4125 -- Not a synchronized operation
4127 else
4128 Resolve (A, Etype (F));
4129 end if;
4130 end if;
4132 A_Typ := Etype (A);
4133 F_Typ := Etype (F);
4135 -- An actual cannot be an untagged formal incomplete type
4137 if Ekind (A_Typ) = E_Incomplete_Type
4138 and then not Is_Tagged_Type (A_Typ)
4139 and then Is_Generic_Type (A_Typ)
4140 then
4141 Error_Msg_N
4142 ("invalid use of untagged formal incomplete type", A);
4143 end if;
4145 if Comes_From_Source (Original_Node (N))
4146 and then Nkind_In (Original_Node (N), N_Function_Call,
4147 N_Procedure_Call_Statement)
4148 then
4149 -- In formal mode, check that actual parameters matching
4150 -- formals of tagged types are objects (or ancestor type
4151 -- conversions of objects), not general expressions.
4153 if Is_Actual_Tagged_Parameter (A) then
4154 if Is_SPARK_05_Object_Reference (A) then
4155 null;
4157 elsif Nkind (A) = N_Type_Conversion then
4158 declare
4159 Operand : constant Node_Id := Expression (A);
4160 Operand_Typ : constant Entity_Id := Etype (Operand);
4161 Target_Typ : constant Entity_Id := A_Typ;
4163 begin
4164 if not Is_SPARK_05_Object_Reference (Operand) then
4165 Check_SPARK_05_Restriction
4166 ("object required", Operand);
4168 -- In formal mode, the only view conversions are those
4169 -- involving ancestor conversion of an extended type.
4171 elsif not
4172 (Is_Tagged_Type (Target_Typ)
4173 and then not Is_Class_Wide_Type (Target_Typ)
4174 and then Is_Tagged_Type (Operand_Typ)
4175 and then not Is_Class_Wide_Type (Operand_Typ)
4176 and then Is_Ancestor (Target_Typ, Operand_Typ))
4177 then
4178 if Ekind_In
4179 (F, E_Out_Parameter, E_In_Out_Parameter)
4180 then
4181 Check_SPARK_05_Restriction
4182 ("ancestor conversion is the only permitted "
4183 & "view conversion", A);
4184 else
4185 Check_SPARK_05_Restriction
4186 ("ancestor conversion required", A);
4187 end if;
4189 else
4190 null;
4191 end if;
4192 end;
4194 else
4195 Check_SPARK_05_Restriction ("object required", A);
4196 end if;
4198 -- In formal mode, the only view conversions are those
4199 -- involving ancestor conversion of an extended type.
4201 elsif Nkind (A) = N_Type_Conversion
4202 and then Ekind_In (F, E_Out_Parameter, E_In_Out_Parameter)
4203 then
4204 Check_SPARK_05_Restriction
4205 ("ancestor conversion is the only permitted view "
4206 & "conversion", A);
4207 end if;
4208 end if;
4210 -- has warnings suppressed, then we reset Never_Set_In_Source for
4211 -- the calling entity. The reason for this is to catch cases like
4212 -- GNAT.Spitbol.Patterns.Vstring_Var where the called subprogram
4213 -- uses trickery to modify an IN parameter.
4215 if Ekind (F) = E_In_Parameter
4216 and then Is_Entity_Name (A)
4217 and then Present (Entity (A))
4218 and then Ekind (Entity (A)) = E_Variable
4219 and then Has_Warnings_Off (F_Typ)
4220 then
4221 Set_Never_Set_In_Source (Entity (A), False);
4222 end if;
4224 -- Perform error checks for IN and IN OUT parameters
4226 if Ekind (F) /= E_Out_Parameter then
4228 -- Check unset reference. For scalar parameters, it is clearly
4229 -- wrong to pass an uninitialized value as either an IN or
4230 -- IN-OUT parameter. For composites, it is also clearly an
4231 -- error to pass a completely uninitialized value as an IN
4232 -- parameter, but the case of IN OUT is trickier. We prefer
4233 -- not to give a warning here. For example, suppose there is
4234 -- a routine that sets some component of a record to False.
4235 -- It is perfectly reasonable to make this IN-OUT and allow
4236 -- either initialized or uninitialized records to be passed
4237 -- in this case.
4239 -- For partially initialized composite values, we also avoid
4240 -- warnings, since it is quite likely that we are passing a
4241 -- partially initialized value and only the initialized fields
4242 -- will in fact be read in the subprogram.
4244 if Is_Scalar_Type (A_Typ)
4245 or else (Ekind (F) = E_In_Parameter
4246 and then not Is_Partially_Initialized_Type (A_Typ))
4247 then
4248 Check_Unset_Reference (A);
4249 end if;
4251 -- In Ada 83 we cannot pass an OUT parameter as an IN or IN OUT
4252 -- actual to a nested call, since this is case of reading an
4253 -- out parameter, which is not allowed.
4255 if Ada_Version = Ada_83
4256 and then Is_Entity_Name (A)
4257 and then Ekind (Entity (A)) = E_Out_Parameter
4258 then
4259 Error_Msg_N ("(Ada 83) illegal reading of out parameter", A);
4260 end if;
4261 end if;
4263 -- Case of OUT or IN OUT parameter
4265 if Ekind (F) /= E_In_Parameter then
4267 -- For an Out parameter, check for useless assignment. Note
4268 -- that we can't set Last_Assignment this early, because we may
4269 -- kill current values in Resolve_Call, and that call would
4270 -- clobber the Last_Assignment field.
4272 -- Note: call Warn_On_Useless_Assignment before doing the check
4273 -- below for Is_OK_Variable_For_Out_Formal so that the setting
4274 -- of Referenced_As_LHS/Referenced_As_Out_Formal properly
4275 -- reflects the last assignment, not this one.
4277 if Ekind (F) = E_Out_Parameter then
4278 if Warn_On_Modified_As_Out_Parameter (F)
4279 and then Is_Entity_Name (A)
4280 and then Present (Entity (A))
4281 and then Comes_From_Source (N)
4282 then
4283 Warn_On_Useless_Assignment (Entity (A), A);
4284 end if;
4285 end if;
4287 -- Validate the form of the actual. Note that the call to
4288 -- Is_OK_Variable_For_Out_Formal generates the required
4289 -- reference in this case.
4291 -- A call to an initialization procedure for an aggregate
4292 -- component may initialize a nested component of a constant
4293 -- designated object. In this context the object is variable.
4295 if not Is_OK_Variable_For_Out_Formal (A)
4296 and then not Is_Init_Proc (Nam)
4297 then
4298 Error_Msg_NE ("actual for& must be a variable", A, F);
4300 if Is_Subprogram (Current_Scope)
4301 and then
4302 (Is_Invariant_Procedure (Current_Scope)
4303 or else Is_Predicate_Function (Current_Scope))
4304 then
4305 Error_Msg_N
4306 ("function used in predicate cannot "
4307 & "modify its argument", F);
4308 end if;
4309 end if;
4311 -- What's the following about???
4313 if Is_Entity_Name (A) then
4314 Kill_Checks (Entity (A));
4315 else
4316 Kill_All_Checks;
4317 end if;
4318 end if;
4320 if Etype (A) = Any_Type then
4321 Set_Etype (N, Any_Type);
4322 return;
4323 end if;
4325 -- Apply appropriate constraint/predicate checks for IN [OUT] case
4327 if Ekind_In (F, E_In_Parameter, E_In_Out_Parameter) then
4329 -- Apply predicate tests except in certain special cases. Note
4330 -- that it might be more consistent to apply these only when
4331 -- expansion is active (in Exp_Ch6.Expand_Actuals), as we do
4332 -- for the outbound predicate tests ???
4334 if Predicate_Tests_On_Arguments (Nam) then
4335 Apply_Predicate_Check (A, F_Typ);
4336 end if;
4338 -- Apply required constraint checks
4340 -- Gigi looks at the check flag and uses the appropriate types.
4341 -- For now since one flag is used there is an optimization
4342 -- which might not be done in the IN OUT case since Gigi does
4343 -- not do any analysis. More thought required about this ???
4345 -- In fact is this comment obsolete??? doesn't the expander now
4346 -- generate all these tests anyway???
4348 if Is_Scalar_Type (Etype (A)) then
4349 Apply_Scalar_Range_Check (A, F_Typ);
4351 elsif Is_Array_Type (Etype (A)) then
4352 Apply_Length_Check (A, F_Typ);
4354 elsif Is_Record_Type (F_Typ)
4355 and then Has_Discriminants (F_Typ)
4356 and then Is_Constrained (F_Typ)
4357 and then (not Is_Derived_Type (F_Typ)
4358 or else Comes_From_Source (Nam))
4359 then
4360 Apply_Discriminant_Check (A, F_Typ);
4362 -- For view conversions of a discriminated object, apply
4363 -- check to object itself, the conversion alreay has the
4364 -- proper type.
4366 if Nkind (A) = N_Type_Conversion
4367 and then Is_Constrained (Etype (Expression (A)))
4368 then
4369 Apply_Discriminant_Check (Expression (A), F_Typ);
4370 end if;
4372 elsif Is_Access_Type (F_Typ)
4373 and then Is_Array_Type (Designated_Type (F_Typ))
4374 and then Is_Constrained (Designated_Type (F_Typ))
4375 then
4376 Apply_Length_Check (A, F_Typ);
4378 elsif Is_Access_Type (F_Typ)
4379 and then Has_Discriminants (Designated_Type (F_Typ))
4380 and then Is_Constrained (Designated_Type (F_Typ))
4381 then
4382 Apply_Discriminant_Check (A, F_Typ);
4384 else
4385 Apply_Range_Check (A, F_Typ);
4386 end if;
4388 -- Ada 2005 (AI-231): Note that the controlling parameter case
4389 -- already existed in Ada 95, which is partially checked
4390 -- elsewhere (see Checks), and we don't want the warning
4391 -- message to differ.
4393 if Is_Access_Type (F_Typ)
4394 and then Can_Never_Be_Null (F_Typ)
4395 and then Known_Null (A)
4396 then
4397 if Is_Controlling_Formal (F) then
4398 Apply_Compile_Time_Constraint_Error
4399 (N => A,
4400 Msg => "null value not allowed here??",
4401 Reason => CE_Access_Check_Failed);
4403 elsif Ada_Version >= Ada_2005 then
4404 Apply_Compile_Time_Constraint_Error
4405 (N => A,
4406 Msg => "(Ada 2005) null not allowed in "
4407 & "null-excluding formal??",
4408 Reason => CE_Null_Not_Allowed);
4409 end if;
4410 end if;
4411 end if;
4413 -- Checks for OUT parameters and IN OUT parameters
4415 if Ekind_In (F, E_Out_Parameter, E_In_Out_Parameter) then
4417 -- If there is a type conversion, to make sure the return value
4418 -- meets the constraints of the variable before the conversion.
4420 if Nkind (A) = N_Type_Conversion then
4421 if Is_Scalar_Type (A_Typ) then
4422 Apply_Scalar_Range_Check
4423 (Expression (A), Etype (Expression (A)), A_Typ);
4424 else
4425 Apply_Range_Check
4426 (Expression (A), Etype (Expression (A)), A_Typ);
4427 end if;
4429 -- If no conversion apply scalar range checks and length checks
4430 -- base on the subtype of the actual (NOT that of the formal).
4432 else
4433 if Is_Scalar_Type (F_Typ) then
4434 Apply_Scalar_Range_Check (A, A_Typ, F_Typ);
4435 elsif Is_Array_Type (F_Typ)
4436 and then Ekind (F) = E_Out_Parameter
4437 then
4438 Apply_Length_Check (A, F_Typ);
4439 else
4440 Apply_Range_Check (A, A_Typ, F_Typ);
4441 end if;
4442 end if;
4444 -- Note: we do not apply the predicate checks for the case of
4445 -- OUT and IN OUT parameters. They are instead applied in the
4446 -- Expand_Actuals routine in Exp_Ch6.
4447 end if;
4449 -- An actual associated with an access parameter is implicitly
4450 -- converted to the anonymous access type of the formal and must
4451 -- satisfy the legality checks for access conversions.
4453 if Ekind (F_Typ) = E_Anonymous_Access_Type then
4454 if not Valid_Conversion (A, F_Typ, A) then
4455 Error_Msg_N
4456 ("invalid implicit conversion for access parameter", A);
4457 end if;
4459 -- If the actual is an access selected component of a variable,
4460 -- the call may modify its designated object. It is reasonable
4461 -- to treat this as a potential modification of the enclosing
4462 -- record, to prevent spurious warnings that it should be
4463 -- declared as a constant, because intuitively programmers
4464 -- regard the designated subcomponent as part of the record.
4466 if Nkind (A) = N_Selected_Component
4467 and then Is_Entity_Name (Prefix (A))
4468 and then not Is_Constant_Object (Entity (Prefix (A)))
4469 then
4470 Note_Possible_Modification (A, Sure => False);
4471 end if;
4472 end if;
4474 -- Check bad case of atomic/volatile argument (RM C.6(12))
4476 if Is_By_Reference_Type (Etype (F))
4477 and then Comes_From_Source (N)
4478 then
4479 if Is_Atomic_Object (A)
4480 and then not Is_Atomic (Etype (F))
4481 then
4482 Error_Msg_NE
4483 ("cannot pass atomic argument to non-atomic formal&",
4484 A, F);
4486 elsif Is_Volatile_Object (A)
4487 and then not Is_Volatile (Etype (F))
4488 then
4489 Error_Msg_NE
4490 ("cannot pass volatile argument to non-volatile formal&",
4491 A, F);
4492 end if;
4493 end if;
4495 -- Check that subprograms don't have improper controlling
4496 -- arguments (RM 3.9.2 (9)).
4498 -- A primitive operation may have an access parameter of an
4499 -- incomplete tagged type, but a dispatching call is illegal
4500 -- if the type is still incomplete.
4502 if Is_Controlling_Formal (F) then
4503 Set_Is_Controlling_Actual (A);
4505 if Ekind (Etype (F)) = E_Anonymous_Access_Type then
4506 declare
4507 Desig : constant Entity_Id := Designated_Type (Etype (F));
4508 begin
4509 if Ekind (Desig) = E_Incomplete_Type
4510 and then No (Full_View (Desig))
4511 and then No (Non_Limited_View (Desig))
4512 then
4513 Error_Msg_NE
4514 ("premature use of incomplete type& "
4515 & "in dispatching call", A, Desig);
4516 end if;
4517 end;
4518 end if;
4520 elsif Nkind (A) = N_Explicit_Dereference then
4521 Validate_Remote_Access_To_Class_Wide_Type (A);
4522 end if;
4524 -- Apply legality rule 3.9.2 (9/1)
4526 if (Is_Class_Wide_Type (A_Typ) or else Is_Dynamically_Tagged (A))
4527 and then not Is_Class_Wide_Type (F_Typ)
4528 and then not Is_Controlling_Formal (F)
4529 and then not In_Instance
4530 then
4531 Error_Msg_N ("class-wide argument not allowed here!", A);
4533 if Is_Subprogram (Nam) and then Comes_From_Source (Nam) then
4534 Error_Msg_Node_2 := F_Typ;
4535 Error_Msg_NE
4536 ("& is not a dispatching operation of &!", A, Nam);
4537 end if;
4539 -- Apply the checks described in 3.10.2(27): if the context is a
4540 -- specific access-to-object, the actual cannot be class-wide.
4541 -- Use base type to exclude access_to_subprogram cases.
4543 elsif Is_Access_Type (A_Typ)
4544 and then Is_Access_Type (F_Typ)
4545 and then not Is_Access_Subprogram_Type (Base_Type (F_Typ))
4546 and then (Is_Class_Wide_Type (Designated_Type (A_Typ))
4547 or else (Nkind (A) = N_Attribute_Reference
4548 and then
4549 Is_Class_Wide_Type (Etype (Prefix (A)))))
4550 and then not Is_Class_Wide_Type (Designated_Type (F_Typ))
4551 and then not Is_Controlling_Formal (F)
4553 -- Disable these checks for call to imported C++ subprograms
4555 and then not
4556 (Is_Entity_Name (Name (N))
4557 and then Is_Imported (Entity (Name (N)))
4558 and then Convention (Entity (Name (N))) = Convention_CPP)
4559 then
4560 Error_Msg_N
4561 ("access to class-wide argument not allowed here!", A);
4563 if Is_Subprogram (Nam) and then Comes_From_Source (Nam) then
4564 Error_Msg_Node_2 := Designated_Type (F_Typ);
4565 Error_Msg_NE
4566 ("& is not a dispatching operation of &!", A, Nam);
4567 end if;
4568 end if;
4570 Check_Aliased_Parameter;
4572 Eval_Actual (A);
4574 -- If it is a named association, treat the selector_name as a
4575 -- proper identifier, and mark the corresponding entity.
4577 if Nkind (Parent (A)) = N_Parameter_Association
4579 -- Ignore reference in SPARK mode, as it refers to an entity not
4580 -- in scope at the point of reference, so the reference should
4581 -- be ignored for computing effects of subprograms.
4583 and then not GNATprove_Mode
4584 then
4585 Set_Entity (Selector_Name (Parent (A)), F);
4586 Generate_Reference (F, Selector_Name (Parent (A)));
4587 Set_Etype (Selector_Name (Parent (A)), F_Typ);
4588 Generate_Reference (F_Typ, N, ' ');
4589 end if;
4591 Prev := A;
4593 if Ekind (F) /= E_Out_Parameter then
4594 Check_Unset_Reference (A);
4595 end if;
4597 -- The following checks are only relevant when SPARK_Mode is on as
4598 -- they are not standard Ada legality rule. Internally generated
4599 -- temporaries are ignored.
4601 if SPARK_Mode = On
4602 and then Is_Effectively_Volatile_Object (A)
4603 and then Comes_From_Source (A)
4604 then
4605 -- An effectively volatile object may act as an actual
4606 -- parameter when the corresponding formal is of a non-scalar
4607 -- volatile type.
4609 if Is_Volatile (Etype (F))
4610 and then not Is_Scalar_Type (Etype (F))
4611 then
4612 null;
4614 -- An effectively volatile object may act as an actual
4615 -- parameter in a call to an instance of Unchecked_Conversion.
4617 elsif Is_Unchecked_Conversion_Instance (Nam) then
4618 null;
4620 else
4621 Error_Msg_N
4622 ("volatile object cannot act as actual in a call (SPARK "
4623 & "RM 7.1.3(12))", A);
4624 end if;
4626 -- Detect an external variable with an enabled property that
4627 -- does not match the mode of the corresponding formal in a
4628 -- procedure call. Functions are not considered because they
4629 -- cannot have effectively volatile formal parameters in the
4630 -- first place.
4632 if Ekind (Nam) = E_Procedure
4633 and then Is_Entity_Name (A)
4634 and then Present (Entity (A))
4635 and then Ekind (Entity (A)) = E_Variable
4636 then
4637 A_Id := Entity (A);
4639 if Ekind (F) = E_In_Parameter then
4640 if Async_Readers_Enabled (A_Id) then
4641 Property_Error (A, A_Id, Name_Async_Readers);
4642 elsif Effective_Reads_Enabled (A_Id) then
4643 Property_Error (A, A_Id, Name_Effective_Reads);
4644 elsif Effective_Writes_Enabled (A_Id) then
4645 Property_Error (A, A_Id, Name_Effective_Writes);
4646 end if;
4648 elsif Ekind (F) = E_Out_Parameter
4649 and then Async_Writers_Enabled (A_Id)
4650 then
4651 Error_Msg_Name_1 := Name_Async_Writers;
4652 Error_Msg_NE
4653 ("external variable & with enabled property % cannot "
4654 & "appear as actual in procedure call "
4655 & "(SPARK RM 7.1.3(11))", A, A_Id);
4656 Error_Msg_N
4657 ("\\corresponding formal parameter has mode Out", A);
4658 end if;
4659 end if;
4660 end if;
4662 -- A formal parameter of a specific tagged type whose related
4663 -- subprogram is subject to pragma Extensions_Visible with value
4664 -- "False" cannot act as an actual in a subprogram with value
4665 -- "True" (SPARK RM 6.1.7(3)).
4667 if Is_EVF_Expression (A)
4668 and then Extensions_Visible_Status (Nam) =
4669 Extensions_Visible_True
4670 then
4671 Error_Msg_N
4672 ("formal parameter with Extensions_Visible False cannot act "
4673 & "as actual parameter", A);
4674 Error_Msg_NE
4675 ("\subprogram & has Extensions_Visible True", A, Nam);
4676 end if;
4678 -- The actual parameter of a Ghost subprogram whose formal is of
4679 -- mode IN OUT or OUT must be a Ghost variable (SPARK RM 6.9(13)).
4681 if Is_Ghost_Entity (Nam)
4682 and then Ekind_In (F, E_In_Out_Parameter, E_Out_Parameter)
4683 and then Is_Entity_Name (A)
4684 and then Present (Entity (A))
4685 and then not Is_Ghost_Entity (Entity (A))
4686 then
4687 Error_Msg_NE
4688 ("non-ghost variable & cannot appear as actual in call to "
4689 & "ghost procedure", A, Entity (A));
4691 if Ekind (F) = E_In_Out_Parameter then
4692 Error_Msg_N ("\corresponding formal has mode `IN OUT`", A);
4693 else
4694 Error_Msg_N ("\corresponding formal has mode OUT", A);
4695 end if;
4696 end if;
4698 Next_Actual (A);
4700 -- Case where actual is not present
4702 else
4703 Insert_Default;
4704 end if;
4706 Next_Formal (F);
4707 end loop;
4708 end Resolve_Actuals;
4710 -----------------------
4711 -- Resolve_Allocator --
4712 -----------------------
4714 procedure Resolve_Allocator (N : Node_Id; Typ : Entity_Id) is
4715 Desig_T : constant Entity_Id := Designated_Type (Typ);
4716 E : constant Node_Id := Expression (N);
4717 Subtyp : Entity_Id;
4718 Discrim : Entity_Id;
4719 Constr : Node_Id;
4720 Aggr : Node_Id;
4721 Assoc : Node_Id := Empty;
4722 Disc_Exp : Node_Id;
4724 procedure Check_Allocator_Discrim_Accessibility
4725 (Disc_Exp : Node_Id;
4726 Alloc_Typ : Entity_Id);
4727 -- Check that accessibility level associated with an access discriminant
4728 -- initialized in an allocator by the expression Disc_Exp is not deeper
4729 -- than the level of the allocator type Alloc_Typ. An error message is
4730 -- issued if this condition is violated. Specialized checks are done for
4731 -- the cases of a constraint expression which is an access attribute or
4732 -- an access discriminant.
4734 function In_Dispatching_Context return Boolean;
4735 -- If the allocator is an actual in a call, it is allowed to be class-
4736 -- wide when the context is not because it is a controlling actual.
4738 -------------------------------------------
4739 -- Check_Allocator_Discrim_Accessibility --
4740 -------------------------------------------
4742 procedure Check_Allocator_Discrim_Accessibility
4743 (Disc_Exp : Node_Id;
4744 Alloc_Typ : Entity_Id)
4746 begin
4747 if Type_Access_Level (Etype (Disc_Exp)) >
4748 Deepest_Type_Access_Level (Alloc_Typ)
4749 then
4750 Error_Msg_N
4751 ("operand type has deeper level than allocator type", Disc_Exp);
4753 -- When the expression is an Access attribute the level of the prefix
4754 -- object must not be deeper than that of the allocator's type.
4756 elsif Nkind (Disc_Exp) = N_Attribute_Reference
4757 and then Get_Attribute_Id (Attribute_Name (Disc_Exp)) =
4758 Attribute_Access
4759 and then Object_Access_Level (Prefix (Disc_Exp)) >
4760 Deepest_Type_Access_Level (Alloc_Typ)
4761 then
4762 Error_Msg_N
4763 ("prefix of attribute has deeper level than allocator type",
4764 Disc_Exp);
4766 -- When the expression is an access discriminant the check is against
4767 -- the level of the prefix object.
4769 elsif Ekind (Etype (Disc_Exp)) = E_Anonymous_Access_Type
4770 and then Nkind (Disc_Exp) = N_Selected_Component
4771 and then Object_Access_Level (Prefix (Disc_Exp)) >
4772 Deepest_Type_Access_Level (Alloc_Typ)
4773 then
4774 Error_Msg_N
4775 ("access discriminant has deeper level than allocator type",
4776 Disc_Exp);
4778 -- All other cases are legal
4780 else
4781 null;
4782 end if;
4783 end Check_Allocator_Discrim_Accessibility;
4785 ----------------------------
4786 -- In_Dispatching_Context --
4787 ----------------------------
4789 function In_Dispatching_Context return Boolean is
4790 Par : constant Node_Id := Parent (N);
4792 begin
4793 return Nkind (Par) in N_Subprogram_Call
4794 and then Is_Entity_Name (Name (Par))
4795 and then Is_Dispatching_Operation (Entity (Name (Par)));
4796 end In_Dispatching_Context;
4798 -- Start of processing for Resolve_Allocator
4800 begin
4801 -- Replace general access with specific type
4803 if Ekind (Etype (N)) = E_Allocator_Type then
4804 Set_Etype (N, Base_Type (Typ));
4805 end if;
4807 if Is_Abstract_Type (Typ) then
4808 Error_Msg_N ("type of allocator cannot be abstract", N);
4809 end if;
4811 -- For qualified expression, resolve the expression using the given
4812 -- subtype (nothing to do for type mark, subtype indication)
4814 if Nkind (E) = N_Qualified_Expression then
4815 if Is_Class_Wide_Type (Etype (E))
4816 and then not Is_Class_Wide_Type (Desig_T)
4817 and then not In_Dispatching_Context
4818 then
4819 Error_Msg_N
4820 ("class-wide allocator not allowed for this access type", N);
4821 end if;
4823 Resolve (Expression (E), Etype (E));
4824 Check_Non_Static_Context (Expression (E));
4825 Check_Unset_Reference (Expression (E));
4827 -- A qualified expression requires an exact match of the type.
4828 -- Class-wide matching is not allowed.
4830 if (Is_Class_Wide_Type (Etype (Expression (E)))
4831 or else Is_Class_Wide_Type (Etype (E)))
4832 and then Base_Type (Etype (Expression (E))) /= Base_Type (Etype (E))
4833 then
4834 Wrong_Type (Expression (E), Etype (E));
4835 end if;
4837 -- Calls to build-in-place functions are not currently supported in
4838 -- allocators for access types associated with a simple storage pool.
4839 -- Supporting such allocators may require passing additional implicit
4840 -- parameters to build-in-place functions (or a significant revision
4841 -- of the current b-i-p implementation to unify the handling for
4842 -- multiple kinds of storage pools). ???
4844 if Is_Limited_View (Desig_T)
4845 and then Nkind (Expression (E)) = N_Function_Call
4846 then
4847 declare
4848 Pool : constant Entity_Id :=
4849 Associated_Storage_Pool (Root_Type (Typ));
4850 begin
4851 if Present (Pool)
4852 and then
4853 Present (Get_Rep_Pragma
4854 (Etype (Pool), Name_Simple_Storage_Pool_Type))
4855 then
4856 Error_Msg_N
4857 ("limited function calls not yet supported in simple "
4858 & "storage pool allocators", Expression (E));
4859 end if;
4860 end;
4861 end if;
4863 -- A special accessibility check is needed for allocators that
4864 -- constrain access discriminants. The level of the type of the
4865 -- expression used to constrain an access discriminant cannot be
4866 -- deeper than the type of the allocator (in contrast to access
4867 -- parameters, where the level of the actual can be arbitrary).
4869 -- We can't use Valid_Conversion to perform this check because in
4870 -- general the type of the allocator is unrelated to the type of
4871 -- the access discriminant.
4873 if Ekind (Typ) /= E_Anonymous_Access_Type
4874 or else Is_Local_Anonymous_Access (Typ)
4875 then
4876 Subtyp := Entity (Subtype_Mark (E));
4878 Aggr := Original_Node (Expression (E));
4880 if Has_Discriminants (Subtyp)
4881 and then Nkind_In (Aggr, N_Aggregate, N_Extension_Aggregate)
4882 then
4883 Discrim := First_Discriminant (Base_Type (Subtyp));
4885 -- Get the first component expression of the aggregate
4887 if Present (Expressions (Aggr)) then
4888 Disc_Exp := First (Expressions (Aggr));
4890 elsif Present (Component_Associations (Aggr)) then
4891 Assoc := First (Component_Associations (Aggr));
4893 if Present (Assoc) then
4894 Disc_Exp := Expression (Assoc);
4895 else
4896 Disc_Exp := Empty;
4897 end if;
4899 else
4900 Disc_Exp := Empty;
4901 end if;
4903 while Present (Discrim) and then Present (Disc_Exp) loop
4904 if Ekind (Etype (Discrim)) = E_Anonymous_Access_Type then
4905 Check_Allocator_Discrim_Accessibility (Disc_Exp, Typ);
4906 end if;
4908 Next_Discriminant (Discrim);
4910 if Present (Discrim) then
4911 if Present (Assoc) then
4912 Next (Assoc);
4913 Disc_Exp := Expression (Assoc);
4915 elsif Present (Next (Disc_Exp)) then
4916 Next (Disc_Exp);
4918 else
4919 Assoc := First (Component_Associations (Aggr));
4921 if Present (Assoc) then
4922 Disc_Exp := Expression (Assoc);
4923 else
4924 Disc_Exp := Empty;
4925 end if;
4926 end if;
4927 end if;
4928 end loop;
4929 end if;
4930 end if;
4932 -- For a subtype mark or subtype indication, freeze the subtype
4934 else
4935 Freeze_Expression (E);
4937 if Is_Access_Constant (Typ) and then not No_Initialization (N) then
4938 Error_Msg_N
4939 ("initialization required for access-to-constant allocator", N);
4940 end if;
4942 -- A special accessibility check is needed for allocators that
4943 -- constrain access discriminants. The level of the type of the
4944 -- expression used to constrain an access discriminant cannot be
4945 -- deeper than the type of the allocator (in contrast to access
4946 -- parameters, where the level of the actual can be arbitrary).
4947 -- We can't use Valid_Conversion to perform this check because
4948 -- in general the type of the allocator is unrelated to the type
4949 -- of the access discriminant.
4951 if Nkind (Original_Node (E)) = N_Subtype_Indication
4952 and then (Ekind (Typ) /= E_Anonymous_Access_Type
4953 or else Is_Local_Anonymous_Access (Typ))
4954 then
4955 Subtyp := Entity (Subtype_Mark (Original_Node (E)));
4957 if Has_Discriminants (Subtyp) then
4958 Discrim := First_Discriminant (Base_Type (Subtyp));
4959 Constr := First (Constraints (Constraint (Original_Node (E))));
4960 while Present (Discrim) and then Present (Constr) loop
4961 if Ekind (Etype (Discrim)) = E_Anonymous_Access_Type then
4962 if Nkind (Constr) = N_Discriminant_Association then
4963 Disc_Exp := Original_Node (Expression (Constr));
4964 else
4965 Disc_Exp := Original_Node (Constr);
4966 end if;
4968 Check_Allocator_Discrim_Accessibility (Disc_Exp, Typ);
4969 end if;
4971 Next_Discriminant (Discrim);
4972 Next (Constr);
4973 end loop;
4974 end if;
4975 end if;
4976 end if;
4978 -- Ada 2005 (AI-344): A class-wide allocator requires an accessibility
4979 -- check that the level of the type of the created object is not deeper
4980 -- than the level of the allocator's access type, since extensions can
4981 -- now occur at deeper levels than their ancestor types. This is a
4982 -- static accessibility level check; a run-time check is also needed in
4983 -- the case of an initialized allocator with a class-wide argument (see
4984 -- Expand_Allocator_Expression).
4986 if Ada_Version >= Ada_2005
4987 and then Is_Class_Wide_Type (Desig_T)
4988 then
4989 declare
4990 Exp_Typ : Entity_Id;
4992 begin
4993 if Nkind (E) = N_Qualified_Expression then
4994 Exp_Typ := Etype (E);
4995 elsif Nkind (E) = N_Subtype_Indication then
4996 Exp_Typ := Entity (Subtype_Mark (Original_Node (E)));
4997 else
4998 Exp_Typ := Entity (E);
4999 end if;
5001 if Type_Access_Level (Exp_Typ) >
5002 Deepest_Type_Access_Level (Typ)
5003 then
5004 if In_Instance_Body then
5005 Error_Msg_Warn := SPARK_Mode /= On;
5006 Error_Msg_N
5007 ("type in allocator has deeper level than "
5008 & "designated class-wide type<<", E);
5009 Error_Msg_N ("\Program_Error [<<", E);
5010 Rewrite (N,
5011 Make_Raise_Program_Error (Sloc (N),
5012 Reason => PE_Accessibility_Check_Failed));
5013 Set_Etype (N, Typ);
5015 -- Do not apply Ada 2005 accessibility checks on a class-wide
5016 -- allocator if the type given in the allocator is a formal
5017 -- type. A run-time check will be performed in the instance.
5019 elsif not Is_Generic_Type (Exp_Typ) then
5020 Error_Msg_N ("type in allocator has deeper level than "
5021 & "designated class-wide type", E);
5022 end if;
5023 end if;
5024 end;
5025 end if;
5027 -- Check for allocation from an empty storage pool
5029 if No_Pool_Assigned (Typ) then
5030 Error_Msg_N ("allocation from empty storage pool!", N);
5032 -- If the context is an unchecked conversion, as may happen within an
5033 -- inlined subprogram, the allocator is being resolved with its own
5034 -- anonymous type. In that case, if the target type has a specific
5035 -- storage pool, it must be inherited explicitly by the allocator type.
5037 elsif Nkind (Parent (N)) = N_Unchecked_Type_Conversion
5038 and then No (Associated_Storage_Pool (Typ))
5039 then
5040 Set_Associated_Storage_Pool
5041 (Typ, Associated_Storage_Pool (Etype (Parent (N))));
5042 end if;
5044 if Ekind (Etype (N)) = E_Anonymous_Access_Type then
5045 Check_Restriction (No_Anonymous_Allocators, N);
5046 end if;
5048 -- Check that an allocator with task parts isn't for a nested access
5049 -- type when restriction No_Task_Hierarchy applies.
5051 if not Is_Library_Level_Entity (Base_Type (Typ))
5052 and then Has_Task (Base_Type (Desig_T))
5053 then
5054 Check_Restriction (No_Task_Hierarchy, N);
5055 end if;
5057 -- An illegal allocator may be rewritten as a raise Program_Error
5058 -- statement.
5060 if Nkind (N) = N_Allocator then
5062 -- An anonymous access discriminant is the definition of a
5063 -- coextension.
5065 if Ekind (Typ) = E_Anonymous_Access_Type
5066 and then Nkind (Associated_Node_For_Itype (Typ)) =
5067 N_Discriminant_Specification
5068 then
5069 declare
5070 Discr : constant Entity_Id :=
5071 Defining_Identifier (Associated_Node_For_Itype (Typ));
5073 begin
5074 Check_Restriction (No_Coextensions, N);
5076 -- Ada 2012 AI05-0052: If the designated type of the allocator
5077 -- is limited, then the allocator shall not be used to define
5078 -- the value of an access discriminant unless the discriminated
5079 -- type is immutably limited.
5081 if Ada_Version >= Ada_2012
5082 and then Is_Limited_Type (Desig_T)
5083 and then not Is_Limited_View (Scope (Discr))
5084 then
5085 Error_Msg_N
5086 ("only immutably limited types can have anonymous "
5087 & "access discriminants designating a limited type", N);
5088 end if;
5089 end;
5091 -- Avoid marking an allocator as a dynamic coextension if it is
5092 -- within a static construct.
5094 if not Is_Static_Coextension (N) then
5095 Set_Is_Dynamic_Coextension (N);
5096 end if;
5098 -- Cleanup for potential static coextensions
5100 else
5101 Set_Is_Dynamic_Coextension (N, False);
5102 Set_Is_Static_Coextension (N, False);
5103 end if;
5104 end if;
5106 -- Report a simple error: if the designated object is a local task,
5107 -- its body has not been seen yet, and its activation will fail an
5108 -- elaboration check.
5110 if Is_Task_Type (Desig_T)
5111 and then Scope (Base_Type (Desig_T)) = Current_Scope
5112 and then Is_Compilation_Unit (Current_Scope)
5113 and then Ekind (Current_Scope) = E_Package
5114 and then not In_Package_Body (Current_Scope)
5115 then
5116 Error_Msg_Warn := SPARK_Mode /= On;
5117 Error_Msg_N ("cannot activate task before body seen<<", N);
5118 Error_Msg_N ("\Program_Error [<<", N);
5119 end if;
5121 -- Ada 2012 (AI05-0111-3): Detect an attempt to allocate a task or a
5122 -- type with a task component on a subpool. This action must raise
5123 -- Program_Error at runtime.
5125 if Ada_Version >= Ada_2012
5126 and then Nkind (N) = N_Allocator
5127 and then Present (Subpool_Handle_Name (N))
5128 and then Has_Task (Desig_T)
5129 then
5130 Error_Msg_Warn := SPARK_Mode /= On;
5131 Error_Msg_N ("cannot allocate task on subpool<<", N);
5132 Error_Msg_N ("\Program_Error [<<", N);
5134 Rewrite (N,
5135 Make_Raise_Program_Error (Sloc (N),
5136 Reason => PE_Explicit_Raise));
5137 Set_Etype (N, Typ);
5138 end if;
5139 end Resolve_Allocator;
5141 ---------------------------
5142 -- Resolve_Arithmetic_Op --
5143 ---------------------------
5145 -- Used for resolving all arithmetic operators except exponentiation
5147 procedure Resolve_Arithmetic_Op (N : Node_Id; Typ : Entity_Id) is
5148 L : constant Node_Id := Left_Opnd (N);
5149 R : constant Node_Id := Right_Opnd (N);
5150 TL : constant Entity_Id := Base_Type (Etype (L));
5151 TR : constant Entity_Id := Base_Type (Etype (R));
5152 T : Entity_Id;
5153 Rop : Node_Id;
5155 B_Typ : constant Entity_Id := Base_Type (Typ);
5156 -- We do the resolution using the base type, because intermediate values
5157 -- in expressions always are of the base type, not a subtype of it.
5159 function Expected_Type_Is_Any_Real (N : Node_Id) return Boolean;
5160 -- Returns True if N is in a context that expects "any real type"
5162 function Is_Integer_Or_Universal (N : Node_Id) return Boolean;
5163 -- Return True iff given type is Integer or universal real/integer
5165 procedure Set_Mixed_Mode_Operand (N : Node_Id; T : Entity_Id);
5166 -- Choose type of integer literal in fixed-point operation to conform
5167 -- to available fixed-point type. T is the type of the other operand,
5168 -- which is needed to determine the expected type of N.
5170 procedure Set_Operand_Type (N : Node_Id);
5171 -- Set operand type to T if universal
5173 -------------------------------
5174 -- Expected_Type_Is_Any_Real --
5175 -------------------------------
5177 function Expected_Type_Is_Any_Real (N : Node_Id) return Boolean is
5178 begin
5179 -- N is the expression after "delta" in a fixed_point_definition;
5180 -- see RM-3.5.9(6):
5182 return Nkind_In (Parent (N), N_Ordinary_Fixed_Point_Definition,
5183 N_Decimal_Fixed_Point_Definition,
5185 -- N is one of the bounds in a real_range_specification;
5186 -- see RM-3.5.7(5):
5188 N_Real_Range_Specification,
5190 -- N is the expression of a delta_constraint;
5191 -- see RM-J.3(3):
5193 N_Delta_Constraint);
5194 end Expected_Type_Is_Any_Real;
5196 -----------------------------
5197 -- Is_Integer_Or_Universal --
5198 -----------------------------
5200 function Is_Integer_Or_Universal (N : Node_Id) return Boolean is
5201 T : Entity_Id;
5202 Index : Interp_Index;
5203 It : Interp;
5205 begin
5206 if not Is_Overloaded (N) then
5207 T := Etype (N);
5208 return Base_Type (T) = Base_Type (Standard_Integer)
5209 or else T = Universal_Integer
5210 or else T = Universal_Real;
5211 else
5212 Get_First_Interp (N, Index, It);
5213 while Present (It.Typ) loop
5214 if Base_Type (It.Typ) = Base_Type (Standard_Integer)
5215 or else It.Typ = Universal_Integer
5216 or else It.Typ = Universal_Real
5217 then
5218 return True;
5219 end if;
5221 Get_Next_Interp (Index, It);
5222 end loop;
5223 end if;
5225 return False;
5226 end Is_Integer_Or_Universal;
5228 ----------------------------
5229 -- Set_Mixed_Mode_Operand --
5230 ----------------------------
5232 procedure Set_Mixed_Mode_Operand (N : Node_Id; T : Entity_Id) is
5233 Index : Interp_Index;
5234 It : Interp;
5236 begin
5237 if Universal_Interpretation (N) = Universal_Integer then
5239 -- A universal integer literal is resolved as standard integer
5240 -- except in the case of a fixed-point result, where we leave it
5241 -- as universal (to be handled by Exp_Fixd later on)
5243 if Is_Fixed_Point_Type (T) then
5244 Resolve (N, Universal_Integer);
5245 else
5246 Resolve (N, Standard_Integer);
5247 end if;
5249 elsif Universal_Interpretation (N) = Universal_Real
5250 and then (T = Base_Type (Standard_Integer)
5251 or else T = Universal_Integer
5252 or else T = Universal_Real)
5253 then
5254 -- A universal real can appear in a fixed-type context. We resolve
5255 -- the literal with that context, even though this might raise an
5256 -- exception prematurely (the other operand may be zero).
5258 Resolve (N, B_Typ);
5260 elsif Etype (N) = Base_Type (Standard_Integer)
5261 and then T = Universal_Real
5262 and then Is_Overloaded (N)
5263 then
5264 -- Integer arg in mixed-mode operation. Resolve with universal
5265 -- type, in case preference rule must be applied.
5267 Resolve (N, Universal_Integer);
5269 elsif Etype (N) = T
5270 and then B_Typ /= Universal_Fixed
5271 then
5272 -- Not a mixed-mode operation, resolve with context
5274 Resolve (N, B_Typ);
5276 elsif Etype (N) = Any_Fixed then
5278 -- N may itself be a mixed-mode operation, so use context type
5280 Resolve (N, B_Typ);
5282 elsif Is_Fixed_Point_Type (T)
5283 and then B_Typ = Universal_Fixed
5284 and then Is_Overloaded (N)
5285 then
5286 -- Must be (fixed * fixed) operation, operand must have one
5287 -- compatible interpretation.
5289 Resolve (N, Any_Fixed);
5291 elsif Is_Fixed_Point_Type (B_Typ)
5292 and then (T = Universal_Real or else Is_Fixed_Point_Type (T))
5293 and then Is_Overloaded (N)
5294 then
5295 -- C * F(X) in a fixed context, where C is a real literal or a
5296 -- fixed-point expression. F must have either a fixed type
5297 -- interpretation or an integer interpretation, but not both.
5299 Get_First_Interp (N, Index, It);
5300 while Present (It.Typ) loop
5301 if Base_Type (It.Typ) = Base_Type (Standard_Integer) then
5302 if Analyzed (N) then
5303 Error_Msg_N ("ambiguous operand in fixed operation", N);
5304 else
5305 Resolve (N, Standard_Integer);
5306 end if;
5308 elsif Is_Fixed_Point_Type (It.Typ) then
5309 if Analyzed (N) then
5310 Error_Msg_N ("ambiguous operand in fixed operation", N);
5311 else
5312 Resolve (N, It.Typ);
5313 end if;
5314 end if;
5316 Get_Next_Interp (Index, It);
5317 end loop;
5319 -- Reanalyze the literal with the fixed type of the context. If
5320 -- context is Universal_Fixed, we are within a conversion, leave
5321 -- the literal as a universal real because there is no usable
5322 -- fixed type, and the target of the conversion plays no role in
5323 -- the resolution.
5325 declare
5326 Op2 : Node_Id;
5327 T2 : Entity_Id;
5329 begin
5330 if N = L then
5331 Op2 := R;
5332 else
5333 Op2 := L;
5334 end if;
5336 if B_Typ = Universal_Fixed
5337 and then Nkind (Op2) = N_Real_Literal
5338 then
5339 T2 := Universal_Real;
5340 else
5341 T2 := B_Typ;
5342 end if;
5344 Set_Analyzed (Op2, False);
5345 Resolve (Op2, T2);
5346 end;
5348 else
5349 Resolve (N);
5350 end if;
5351 end Set_Mixed_Mode_Operand;
5353 ----------------------
5354 -- Set_Operand_Type --
5355 ----------------------
5357 procedure Set_Operand_Type (N : Node_Id) is
5358 begin
5359 if Etype (N) = Universal_Integer
5360 or else Etype (N) = Universal_Real
5361 then
5362 Set_Etype (N, T);
5363 end if;
5364 end Set_Operand_Type;
5366 -- Start of processing for Resolve_Arithmetic_Op
5368 begin
5369 if Comes_From_Source (N)
5370 and then Ekind (Entity (N)) = E_Function
5371 and then Is_Imported (Entity (N))
5372 and then Is_Intrinsic_Subprogram (Entity (N))
5373 then
5374 Resolve_Intrinsic_Operator (N, Typ);
5375 return;
5377 -- Special-case for mixed-mode universal expressions or fixed point type
5378 -- operation: each argument is resolved separately. The same treatment
5379 -- is required if one of the operands of a fixed point operation is
5380 -- universal real, since in this case we don't do a conversion to a
5381 -- specific fixed-point type (instead the expander handles the case).
5383 -- Set the type of the node to its universal interpretation because
5384 -- legality checks on an exponentiation operand need the context.
5386 elsif (B_Typ = Universal_Integer or else B_Typ = Universal_Real)
5387 and then Present (Universal_Interpretation (L))
5388 and then Present (Universal_Interpretation (R))
5389 then
5390 Set_Etype (N, B_Typ);
5391 Resolve (L, Universal_Interpretation (L));
5392 Resolve (R, Universal_Interpretation (R));
5394 elsif (B_Typ = Universal_Real
5395 or else Etype (N) = Universal_Fixed
5396 or else (Etype (N) = Any_Fixed
5397 and then Is_Fixed_Point_Type (B_Typ))
5398 or else (Is_Fixed_Point_Type (B_Typ)
5399 and then (Is_Integer_Or_Universal (L)
5400 or else
5401 Is_Integer_Or_Universal (R))))
5402 and then Nkind_In (N, N_Op_Multiply, N_Op_Divide)
5403 then
5404 if TL = Universal_Integer or else TR = Universal_Integer then
5405 Check_For_Visible_Operator (N, B_Typ);
5406 end if;
5408 -- If context is a fixed type and one operand is integer, the other
5409 -- is resolved with the type of the context.
5411 if Is_Fixed_Point_Type (B_Typ)
5412 and then (Base_Type (TL) = Base_Type (Standard_Integer)
5413 or else TL = Universal_Integer)
5414 then
5415 Resolve (R, B_Typ);
5416 Resolve (L, TL);
5418 elsif Is_Fixed_Point_Type (B_Typ)
5419 and then (Base_Type (TR) = Base_Type (Standard_Integer)
5420 or else TR = Universal_Integer)
5421 then
5422 Resolve (L, B_Typ);
5423 Resolve (R, TR);
5425 else
5426 Set_Mixed_Mode_Operand (L, TR);
5427 Set_Mixed_Mode_Operand (R, TL);
5428 end if;
5430 -- Check the rule in RM05-4.5.5(19.1/2) disallowing universal_fixed
5431 -- multiplying operators from being used when the expected type is
5432 -- also universal_fixed. Note that B_Typ will be Universal_Fixed in
5433 -- some cases where the expected type is actually Any_Real;
5434 -- Expected_Type_Is_Any_Real takes care of that case.
5436 if Etype (N) = Universal_Fixed
5437 or else Etype (N) = Any_Fixed
5438 then
5439 if B_Typ = Universal_Fixed
5440 and then not Expected_Type_Is_Any_Real (N)
5441 and then not Nkind_In (Parent (N), N_Type_Conversion,
5442 N_Unchecked_Type_Conversion)
5443 then
5444 Error_Msg_N ("type cannot be determined from context!", N);
5445 Error_Msg_N ("\explicit conversion to result type required", N);
5447 Set_Etype (L, Any_Type);
5448 Set_Etype (R, Any_Type);
5450 else
5451 if Ada_Version = Ada_83
5452 and then Etype (N) = Universal_Fixed
5453 and then not
5454 Nkind_In (Parent (N), N_Type_Conversion,
5455 N_Unchecked_Type_Conversion)
5456 then
5457 Error_Msg_N
5458 ("(Ada 83) fixed-point operation "
5459 & "needs explicit conversion", N);
5460 end if;
5462 -- The expected type is "any real type" in contexts like
5464 -- type T is delta <universal_fixed-expression> ...
5466 -- in which case we need to set the type to Universal_Real
5467 -- so that static expression evaluation will work properly.
5469 if Expected_Type_Is_Any_Real (N) then
5470 Set_Etype (N, Universal_Real);
5471 else
5472 Set_Etype (N, B_Typ);
5473 end if;
5474 end if;
5476 elsif Is_Fixed_Point_Type (B_Typ)
5477 and then (Is_Integer_Or_Universal (L)
5478 or else Nkind (L) = N_Real_Literal
5479 or else Nkind (R) = N_Real_Literal
5480 or else Is_Integer_Or_Universal (R))
5481 then
5482 Set_Etype (N, B_Typ);
5484 elsif Etype (N) = Any_Fixed then
5486 -- If no previous errors, this is only possible if one operand is
5487 -- overloaded and the context is universal. Resolve as such.
5489 Set_Etype (N, B_Typ);
5490 end if;
5492 else
5493 if (TL = Universal_Integer or else TL = Universal_Real)
5494 and then
5495 (TR = Universal_Integer or else TR = Universal_Real)
5496 then
5497 Check_For_Visible_Operator (N, B_Typ);
5498 end if;
5500 -- If the context is Universal_Fixed and the operands are also
5501 -- universal fixed, this is an error, unless there is only one
5502 -- applicable fixed_point type (usually Duration).
5504 if B_Typ = Universal_Fixed and then Etype (L) = Universal_Fixed then
5505 T := Unique_Fixed_Point_Type (N);
5507 if T = Any_Type then
5508 Set_Etype (N, T);
5509 return;
5510 else
5511 Resolve (L, T);
5512 Resolve (R, T);
5513 end if;
5515 else
5516 Resolve (L, B_Typ);
5517 Resolve (R, B_Typ);
5518 end if;
5520 -- If one of the arguments was resolved to a non-universal type.
5521 -- label the result of the operation itself with the same type.
5522 -- Do the same for the universal argument, if any.
5524 T := Intersect_Types (L, R);
5525 Set_Etype (N, Base_Type (T));
5526 Set_Operand_Type (L);
5527 Set_Operand_Type (R);
5528 end if;
5530 Generate_Operator_Reference (N, Typ);
5531 Analyze_Dimension (N);
5532 Eval_Arithmetic_Op (N);
5534 -- In SPARK, a multiplication or division with operands of fixed point
5535 -- types must be qualified or explicitly converted to identify the
5536 -- result type.
5538 if (Is_Fixed_Point_Type (Etype (L))
5539 or else Is_Fixed_Point_Type (Etype (R)))
5540 and then Nkind_In (N, N_Op_Multiply, N_Op_Divide)
5541 and then
5542 not Nkind_In (Parent (N), N_Qualified_Expression, N_Type_Conversion)
5543 then
5544 Check_SPARK_05_Restriction
5545 ("operation should be qualified or explicitly converted", N);
5546 end if;
5548 -- Set overflow and division checking bit
5550 if Nkind (N) in N_Op then
5551 if not Overflow_Checks_Suppressed (Etype (N)) then
5552 Enable_Overflow_Check (N);
5553 end if;
5555 -- Give warning if explicit division by zero
5557 if Nkind_In (N, N_Op_Divide, N_Op_Rem, N_Op_Mod)
5558 and then not Division_Checks_Suppressed (Etype (N))
5559 then
5560 Rop := Right_Opnd (N);
5562 if Compile_Time_Known_Value (Rop)
5563 and then ((Is_Integer_Type (Etype (Rop))
5564 and then Expr_Value (Rop) = Uint_0)
5565 or else
5566 (Is_Real_Type (Etype (Rop))
5567 and then Expr_Value_R (Rop) = Ureal_0))
5568 then
5569 -- Specialize the warning message according to the operation.
5570 -- The following warnings are for the case
5572 case Nkind (N) is
5573 when N_Op_Divide =>
5575 -- For division, we have two cases, for float division
5576 -- of an unconstrained float type, on a machine where
5577 -- Machine_Overflows is false, we don't get an exception
5578 -- at run-time, but rather an infinity or Nan. The Nan
5579 -- case is pretty obscure, so just warn about infinities.
5581 if Is_Floating_Point_Type (Typ)
5582 and then not Is_Constrained (Typ)
5583 and then not Machine_Overflows_On_Target
5584 then
5585 Error_Msg_N
5586 ("float division by zero, may generate "
5587 & "'+'/'- infinity??", Right_Opnd (N));
5589 -- For all other cases, we get a Constraint_Error
5591 else
5592 Apply_Compile_Time_Constraint_Error
5593 (N, "division by zero??", CE_Divide_By_Zero,
5594 Loc => Sloc (Right_Opnd (N)));
5595 end if;
5597 when N_Op_Rem =>
5598 Apply_Compile_Time_Constraint_Error
5599 (N, "rem with zero divisor??", CE_Divide_By_Zero,
5600 Loc => Sloc (Right_Opnd (N)));
5602 when N_Op_Mod =>
5603 Apply_Compile_Time_Constraint_Error
5604 (N, "mod with zero divisor??", CE_Divide_By_Zero,
5605 Loc => Sloc (Right_Opnd (N)));
5607 -- Division by zero can only happen with division, rem,
5608 -- and mod operations.
5610 when others =>
5611 raise Program_Error;
5612 end case;
5614 -- Otherwise just set the flag to check at run time
5616 else
5617 Activate_Division_Check (N);
5618 end if;
5619 end if;
5621 -- If Restriction No_Implicit_Conditionals is active, then it is
5622 -- violated if either operand can be negative for mod, or for rem
5623 -- if both operands can be negative.
5625 if Restriction_Check_Required (No_Implicit_Conditionals)
5626 and then Nkind_In (N, N_Op_Rem, N_Op_Mod)
5627 then
5628 declare
5629 Lo : Uint;
5630 Hi : Uint;
5631 OK : Boolean;
5633 LNeg : Boolean;
5634 RNeg : Boolean;
5635 -- Set if corresponding operand might be negative
5637 begin
5638 Determine_Range
5639 (Left_Opnd (N), OK, Lo, Hi, Assume_Valid => True);
5640 LNeg := (not OK) or else Lo < 0;
5642 Determine_Range
5643 (Right_Opnd (N), OK, Lo, Hi, Assume_Valid => True);
5644 RNeg := (not OK) or else Lo < 0;
5646 -- Check if we will be generating conditionals. There are two
5647 -- cases where that can happen, first for REM, the only case
5648 -- is largest negative integer mod -1, where the division can
5649 -- overflow, but we still have to give the right result. The
5650 -- front end generates a test for this annoying case. Here we
5651 -- just test if both operands can be negative (that's what the
5652 -- expander does, so we match its logic here).
5654 -- The second case is mod where either operand can be negative.
5655 -- In this case, the back end has to generate additional tests.
5657 if (Nkind (N) = N_Op_Rem and then (LNeg and RNeg))
5658 or else
5659 (Nkind (N) = N_Op_Mod and then (LNeg or RNeg))
5660 then
5661 Check_Restriction (No_Implicit_Conditionals, N);
5662 end if;
5663 end;
5664 end if;
5665 end if;
5667 Check_Unset_Reference (L);
5668 Check_Unset_Reference (R);
5669 Check_Function_Writable_Actuals (N);
5670 end Resolve_Arithmetic_Op;
5672 ------------------
5673 -- Resolve_Call --
5674 ------------------
5676 procedure Resolve_Call (N : Node_Id; Typ : Entity_Id) is
5677 function Same_Or_Aliased_Subprograms
5678 (S : Entity_Id;
5679 E : Entity_Id) return Boolean;
5680 -- Returns True if the subprogram entity S is the same as E or else
5681 -- S is an alias of E.
5683 ---------------------------------
5684 -- Same_Or_Aliased_Subprograms --
5685 ---------------------------------
5687 function Same_Or_Aliased_Subprograms
5688 (S : Entity_Id;
5689 E : Entity_Id) return Boolean
5691 Subp_Alias : constant Entity_Id := Alias (S);
5692 begin
5693 return S = E or else (Present (Subp_Alias) and then Subp_Alias = E);
5694 end Same_Or_Aliased_Subprograms;
5696 -- Local variables
5698 Loc : constant Source_Ptr := Sloc (N);
5699 Subp : constant Node_Id := Name (N);
5700 Body_Id : Entity_Id;
5701 I : Interp_Index;
5702 It : Interp;
5703 Nam : Entity_Id;
5704 Nam_Decl : Node_Id;
5705 Nam_UA : Entity_Id;
5706 Norm_OK : Boolean;
5707 Rtype : Entity_Id;
5708 Scop : Entity_Id;
5710 -- Start of processing for Resolve_Call
5712 begin
5713 -- The context imposes a unique interpretation with type Typ on a
5714 -- procedure or function call. Find the entity of the subprogram that
5715 -- yields the expected type, and propagate the corresponding formal
5716 -- constraints on the actuals. The caller has established that an
5717 -- interpretation exists, and emitted an error if not unique.
5719 -- First deal with the case of a call to an access-to-subprogram,
5720 -- dereference made explicit in Analyze_Call.
5722 if Ekind (Etype (Subp)) = E_Subprogram_Type then
5723 if not Is_Overloaded (Subp) then
5724 Nam := Etype (Subp);
5726 else
5727 -- Find the interpretation whose type (a subprogram type) has a
5728 -- return type that is compatible with the context. Analysis of
5729 -- the node has established that one exists.
5731 Nam := Empty;
5733 Get_First_Interp (Subp, I, It);
5734 while Present (It.Typ) loop
5735 if Covers (Typ, Etype (It.Typ)) then
5736 Nam := It.Typ;
5737 exit;
5738 end if;
5740 Get_Next_Interp (I, It);
5741 end loop;
5743 if No (Nam) then
5744 raise Program_Error;
5745 end if;
5746 end if;
5748 -- If the prefix is not an entity, then resolve it
5750 if not Is_Entity_Name (Subp) then
5751 Resolve (Subp, Nam);
5752 end if;
5754 -- For an indirect call, we always invalidate checks, since we do not
5755 -- know whether the subprogram is local or global. Yes we could do
5756 -- better here, e.g. by knowing that there are no local subprograms,
5757 -- but it does not seem worth the effort. Similarly, we kill all
5758 -- knowledge of current constant values.
5760 Kill_Current_Values;
5762 -- If this is a procedure call which is really an entry call, do
5763 -- the conversion of the procedure call to an entry call. Protected
5764 -- operations use the same circuitry because the name in the call
5765 -- can be an arbitrary expression with special resolution rules.
5767 elsif Nkind_In (Subp, N_Selected_Component, N_Indexed_Component)
5768 or else (Is_Entity_Name (Subp)
5769 and then Ekind (Entity (Subp)) = E_Entry)
5770 then
5771 Resolve_Entry_Call (N, Typ);
5772 Check_Elab_Call (N);
5774 -- Kill checks and constant values, as above for indirect case
5775 -- Who knows what happens when another task is activated?
5777 Kill_Current_Values;
5778 return;
5780 -- Normal subprogram call with name established in Resolve
5782 elsif not (Is_Type (Entity (Subp))) then
5783 Nam := Entity (Subp);
5784 Set_Entity_With_Checks (Subp, Nam);
5786 -- Otherwise we must have the case of an overloaded call
5788 else
5789 pragma Assert (Is_Overloaded (Subp));
5791 -- Initialize Nam to prevent warning (we know it will be assigned
5792 -- in the loop below, but the compiler does not know that).
5794 Nam := Empty;
5796 Get_First_Interp (Subp, I, It);
5797 while Present (It.Typ) loop
5798 if Covers (Typ, It.Typ) then
5799 Nam := It.Nam;
5800 Set_Entity_With_Checks (Subp, Nam);
5801 exit;
5802 end if;
5804 Get_Next_Interp (I, It);
5805 end loop;
5806 end if;
5808 if Is_Access_Subprogram_Type (Base_Type (Etype (Nam)))
5809 and then not Is_Access_Subprogram_Type (Base_Type (Typ))
5810 and then Nkind (Subp) /= N_Explicit_Dereference
5811 and then Present (Parameter_Associations (N))
5812 then
5813 -- The prefix is a parameterless function call that returns an access
5814 -- to subprogram. If parameters are present in the current call, add
5815 -- add an explicit dereference. We use the base type here because
5816 -- within an instance these may be subtypes.
5818 -- The dereference is added either in Analyze_Call or here. Should
5819 -- be consolidated ???
5821 Set_Is_Overloaded (Subp, False);
5822 Set_Etype (Subp, Etype (Nam));
5823 Insert_Explicit_Dereference (Subp);
5824 Nam := Designated_Type (Etype (Nam));
5825 Resolve (Subp, Nam);
5826 end if;
5828 -- Check that a call to Current_Task does not occur in an entry body
5830 if Is_RTE (Nam, RE_Current_Task) then
5831 declare
5832 P : Node_Id;
5834 begin
5835 P := N;
5836 loop
5837 P := Parent (P);
5839 -- Exclude calls that occur within the default of a formal
5840 -- parameter of the entry, since those are evaluated outside
5841 -- of the body.
5843 exit when No (P) or else Nkind (P) = N_Parameter_Specification;
5845 if Nkind (P) = N_Entry_Body
5846 or else (Nkind (P) = N_Subprogram_Body
5847 and then Is_Entry_Barrier_Function (P))
5848 then
5849 Rtype := Etype (N);
5850 Error_Msg_Warn := SPARK_Mode /= On;
5851 Error_Msg_NE
5852 ("& should not be used in entry body (RM C.7(17))<<",
5853 N, Nam);
5854 Error_Msg_NE ("\Program_Error [<<", N, Nam);
5855 Rewrite (N,
5856 Make_Raise_Program_Error (Loc,
5857 Reason => PE_Current_Task_In_Entry_Body));
5858 Set_Etype (N, Rtype);
5859 return;
5860 end if;
5861 end loop;
5862 end;
5863 end if;
5865 -- Check that a procedure call does not occur in the context of the
5866 -- entry call statement of a conditional or timed entry call. Note that
5867 -- the case of a call to a subprogram renaming of an entry will also be
5868 -- rejected. The test for N not being an N_Entry_Call_Statement is
5869 -- defensive, covering the possibility that the processing of entry
5870 -- calls might reach this point due to later modifications of the code
5871 -- above.
5873 if Nkind (Parent (N)) = N_Entry_Call_Alternative
5874 and then Nkind (N) /= N_Entry_Call_Statement
5875 and then Entry_Call_Statement (Parent (N)) = N
5876 then
5877 if Ada_Version < Ada_2005 then
5878 Error_Msg_N ("entry call required in select statement", N);
5880 -- Ada 2005 (AI-345): If a procedure_call_statement is used
5881 -- for a procedure_or_entry_call, the procedure_name or
5882 -- procedure_prefix of the procedure_call_statement shall denote
5883 -- an entry renamed by a procedure, or (a view of) a primitive
5884 -- subprogram of a limited interface whose first parameter is
5885 -- a controlling parameter.
5887 elsif Nkind (N) = N_Procedure_Call_Statement
5888 and then not Is_Renamed_Entry (Nam)
5889 and then not Is_Controlling_Limited_Procedure (Nam)
5890 then
5891 Error_Msg_N
5892 ("entry call or dispatching primitive of interface required", N);
5893 end if;
5894 end if;
5896 -- If the SPARK_05 restriction is active, we are not allowed
5897 -- to have a call to a subprogram before we see its completion.
5899 if not Has_Completion (Nam)
5900 and then Restriction_Check_Required (SPARK_05)
5902 -- Don't flag strange internal calls
5904 and then Comes_From_Source (N)
5905 and then Comes_From_Source (Nam)
5907 -- Only flag calls in extended main source
5909 and then In_Extended_Main_Source_Unit (Nam)
5910 and then In_Extended_Main_Source_Unit (N)
5912 -- Exclude enumeration literals from this processing
5914 and then Ekind (Nam) /= E_Enumeration_Literal
5915 then
5916 Check_SPARK_05_Restriction
5917 ("call to subprogram cannot appear before its body", N);
5918 end if;
5920 -- Check that this is not a call to a protected procedure or entry from
5921 -- within a protected function.
5923 Check_Internal_Protected_Use (N, Nam);
5925 -- Freeze the subprogram name if not in a spec-expression. Note that
5926 -- we freeze procedure calls as well as function calls. Procedure calls
5927 -- are not frozen according to the rules (RM 13.14(14)) because it is
5928 -- impossible to have a procedure call to a non-frozen procedure in
5929 -- pure Ada, but in the code that we generate in the expander, this
5930 -- rule needs extending because we can generate procedure calls that
5931 -- need freezing.
5933 -- In Ada 2012, expression functions may be called within pre/post
5934 -- conditions of subsequent functions or expression functions. Such
5935 -- calls do not freeze when they appear within generated bodies,
5936 -- (including the body of another expression function) which would
5937 -- place the freeze node in the wrong scope. An expression function
5938 -- is frozen in the usual fashion, by the appearance of a real body,
5939 -- or at the end of a declarative part.
5941 if Is_Entity_Name (Subp) and then not In_Spec_Expression
5942 and then not Is_Expression_Function (Current_Scope)
5943 and then
5944 (not Is_Expression_Function (Entity (Subp))
5945 or else Scope (Entity (Subp)) = Current_Scope)
5946 then
5947 Freeze_Expression (Subp);
5948 end if;
5950 -- For a predefined operator, the type of the result is the type imposed
5951 -- by context, except for a predefined operation on universal fixed.
5952 -- Otherwise The type of the call is the type returned by the subprogram
5953 -- being called.
5955 if Is_Predefined_Op (Nam) then
5956 if Etype (N) /= Universal_Fixed then
5957 Set_Etype (N, Typ);
5958 end if;
5960 -- If the subprogram returns an array type, and the context requires the
5961 -- component type of that array type, the node is really an indexing of
5962 -- the parameterless call. Resolve as such. A pathological case occurs
5963 -- when the type of the component is an access to the array type. In
5964 -- this case the call is truly ambiguous.
5966 elsif (Needs_No_Actuals (Nam) or else Needs_One_Actual (Nam))
5967 and then
5968 ((Is_Array_Type (Etype (Nam))
5969 and then Covers (Typ, Component_Type (Etype (Nam))))
5970 or else
5971 (Is_Access_Type (Etype (Nam))
5972 and then Is_Array_Type (Designated_Type (Etype (Nam)))
5973 and then
5974 Covers (Typ, Component_Type (Designated_Type (Etype (Nam))))))
5975 then
5976 declare
5977 Index_Node : Node_Id;
5978 New_Subp : Node_Id;
5979 Ret_Type : constant Entity_Id := Etype (Nam);
5981 begin
5982 if Is_Access_Type (Ret_Type)
5983 and then Ret_Type = Component_Type (Designated_Type (Ret_Type))
5984 then
5985 Error_Msg_N
5986 ("cannot disambiguate function call and indexing", N);
5987 else
5988 New_Subp := Relocate_Node (Subp);
5990 -- The called entity may be an explicit dereference, in which
5991 -- case there is no entity to set.
5993 if Nkind (New_Subp) /= N_Explicit_Dereference then
5994 Set_Entity (Subp, Nam);
5995 end if;
5997 if (Is_Array_Type (Ret_Type)
5998 and then Component_Type (Ret_Type) /= Any_Type)
5999 or else
6000 (Is_Access_Type (Ret_Type)
6001 and then
6002 Component_Type (Designated_Type (Ret_Type)) /= Any_Type)
6003 then
6004 if Needs_No_Actuals (Nam) then
6006 -- Indexed call to a parameterless function
6008 Index_Node :=
6009 Make_Indexed_Component (Loc,
6010 Prefix =>
6011 Make_Function_Call (Loc, Name => New_Subp),
6012 Expressions => Parameter_Associations (N));
6013 else
6014 -- An Ada 2005 prefixed call to a primitive operation
6015 -- whose first parameter is the prefix. This prefix was
6016 -- prepended to the parameter list, which is actually a
6017 -- list of indexes. Remove the prefix in order to build
6018 -- the proper indexed component.
6020 Index_Node :=
6021 Make_Indexed_Component (Loc,
6022 Prefix =>
6023 Make_Function_Call (Loc,
6024 Name => New_Subp,
6025 Parameter_Associations =>
6026 New_List
6027 (Remove_Head (Parameter_Associations (N)))),
6028 Expressions => Parameter_Associations (N));
6029 end if;
6031 -- Preserve the parenthesis count of the node
6033 Set_Paren_Count (Index_Node, Paren_Count (N));
6035 -- Since we are correcting a node classification error made
6036 -- by the parser, we call Replace rather than Rewrite.
6038 Replace (N, Index_Node);
6040 Set_Etype (Prefix (N), Ret_Type);
6041 Set_Etype (N, Typ);
6042 Resolve_Indexed_Component (N, Typ);
6043 Check_Elab_Call (Prefix (N));
6044 end if;
6045 end if;
6047 return;
6048 end;
6050 else
6051 Set_Etype (N, Etype (Nam));
6052 end if;
6054 -- In the case where the call is to an overloaded subprogram, Analyze
6055 -- calls Normalize_Actuals once per overloaded subprogram. Therefore in
6056 -- such a case Normalize_Actuals needs to be called once more to order
6057 -- the actuals correctly. Otherwise the call will have the ordering
6058 -- given by the last overloaded subprogram whether this is the correct
6059 -- one being called or not.
6061 if Is_Overloaded (Subp) then
6062 Normalize_Actuals (N, Nam, False, Norm_OK);
6063 pragma Assert (Norm_OK);
6064 end if;
6066 -- In any case, call is fully resolved now. Reset Overload flag, to
6067 -- prevent subsequent overload resolution if node is analyzed again
6069 Set_Is_Overloaded (Subp, False);
6070 Set_Is_Overloaded (N, False);
6072 -- A Ghost entity must appear in a specific context
6074 if Is_Ghost_Entity (Nam) and then Comes_From_Source (N) then
6075 Check_Ghost_Context (Nam, N);
6076 end if;
6078 -- If we are calling the current subprogram from immediately within its
6079 -- body, then that is the case where we can sometimes detect cases of
6080 -- infinite recursion statically. Do not try this in case restriction
6081 -- No_Recursion is in effect anyway, and do it only for source calls.
6083 if Comes_From_Source (N) then
6084 Scop := Current_Scope;
6086 -- Check violation of SPARK_05 restriction which does not permit
6087 -- a subprogram body to contain a call to the subprogram directly.
6089 if Restriction_Check_Required (SPARK_05)
6090 and then Same_Or_Aliased_Subprograms (Nam, Scop)
6091 then
6092 Check_SPARK_05_Restriction
6093 ("subprogram may not contain direct call to itself", N);
6094 end if;
6096 -- Issue warning for possible infinite recursion in the absence
6097 -- of the No_Recursion restriction.
6099 if Same_Or_Aliased_Subprograms (Nam, Scop)
6100 and then not Restriction_Active (No_Recursion)
6101 and then Check_Infinite_Recursion (N)
6102 then
6103 -- Here we detected and flagged an infinite recursion, so we do
6104 -- not need to test the case below for further warnings. Also we
6105 -- are all done if we now have a raise SE node.
6107 if Nkind (N) = N_Raise_Storage_Error then
6108 return;
6109 end if;
6111 -- If call is to immediately containing subprogram, then check for
6112 -- the case of a possible run-time detectable infinite recursion.
6114 else
6115 Scope_Loop : while Scop /= Standard_Standard loop
6116 if Same_Or_Aliased_Subprograms (Nam, Scop) then
6118 -- Although in general case, recursion is not statically
6119 -- checkable, the case of calling an immediately containing
6120 -- subprogram is easy to catch.
6122 Check_Restriction (No_Recursion, N);
6124 -- If the recursive call is to a parameterless subprogram,
6125 -- then even if we can't statically detect infinite
6126 -- recursion, this is pretty suspicious, and we output a
6127 -- warning. Furthermore, we will try later to detect some
6128 -- cases here at run time by expanding checking code (see
6129 -- Detect_Infinite_Recursion in package Exp_Ch6).
6131 -- If the recursive call is within a handler, do not emit a
6132 -- warning, because this is a common idiom: loop until input
6133 -- is correct, catch illegal input in handler and restart.
6135 if No (First_Formal (Nam))
6136 and then Etype (Nam) = Standard_Void_Type
6137 and then not Error_Posted (N)
6138 and then Nkind (Parent (N)) /= N_Exception_Handler
6139 then
6140 -- For the case of a procedure call. We give the message
6141 -- only if the call is the first statement in a sequence
6142 -- of statements, or if all previous statements are
6143 -- simple assignments. This is simply a heuristic to
6144 -- decrease false positives, without losing too many good
6145 -- warnings. The idea is that these previous statements
6146 -- may affect global variables the procedure depends on.
6147 -- We also exclude raise statements, that may arise from
6148 -- constraint checks and are probably unrelated to the
6149 -- intended control flow.
6151 if Nkind (N) = N_Procedure_Call_Statement
6152 and then Is_List_Member (N)
6153 then
6154 declare
6155 P : Node_Id;
6156 begin
6157 P := Prev (N);
6158 while Present (P) loop
6159 if not Nkind_In (P, N_Assignment_Statement,
6160 N_Raise_Constraint_Error)
6161 then
6162 exit Scope_Loop;
6163 end if;
6165 Prev (P);
6166 end loop;
6167 end;
6168 end if;
6170 -- Do not give warning if we are in a conditional context
6172 declare
6173 K : constant Node_Kind := Nkind (Parent (N));
6174 begin
6175 if (K = N_Loop_Statement
6176 and then Present (Iteration_Scheme (Parent (N))))
6177 or else K = N_If_Statement
6178 or else K = N_Elsif_Part
6179 or else K = N_Case_Statement_Alternative
6180 then
6181 exit Scope_Loop;
6182 end if;
6183 end;
6185 -- Here warning is to be issued
6187 Set_Has_Recursive_Call (Nam);
6188 Error_Msg_Warn := SPARK_Mode /= On;
6189 Error_Msg_N ("possible infinite recursion<<!", N);
6190 Error_Msg_N ("\Storage_Error ]<<!", N);
6191 end if;
6193 exit Scope_Loop;
6194 end if;
6196 Scop := Scope (Scop);
6197 end loop Scope_Loop;
6198 end if;
6199 end if;
6201 -- Check obsolescent reference to Ada.Characters.Handling subprogram
6203 Check_Obsolescent_2005_Entity (Nam, Subp);
6205 -- If subprogram name is a predefined operator, it was given in
6206 -- functional notation. Replace call node with operator node, so
6207 -- that actuals can be resolved appropriately.
6209 if Is_Predefined_Op (Nam) or else Ekind (Nam) = E_Operator then
6210 Make_Call_Into_Operator (N, Typ, Entity (Name (N)));
6211 return;
6213 elsif Present (Alias (Nam))
6214 and then Is_Predefined_Op (Alias (Nam))
6215 then
6216 Resolve_Actuals (N, Nam);
6217 Make_Call_Into_Operator (N, Typ, Alias (Nam));
6218 return;
6219 end if;
6221 -- Create a transient scope if the resulting type requires it
6223 -- There are several notable exceptions:
6225 -- a) In init procs, the transient scope overhead is not needed, and is
6226 -- even incorrect when the call is a nested initialization call for a
6227 -- component whose expansion may generate adjust calls. However, if the
6228 -- call is some other procedure call within an initialization procedure
6229 -- (for example a call to Create_Task in the init_proc of the task
6230 -- run-time record) a transient scope must be created around this call.
6232 -- b) Enumeration literal pseudo-calls need no transient scope
6234 -- c) Intrinsic subprograms (Unchecked_Conversion and source info
6235 -- functions) do not use the secondary stack even though the return
6236 -- type may be unconstrained.
6238 -- d) Calls to a build-in-place function, since such functions may
6239 -- allocate their result directly in a target object, and cases where
6240 -- the result does get allocated in the secondary stack are checked for
6241 -- within the specialized Exp_Ch6 procedures for expanding those
6242 -- build-in-place calls.
6244 -- e) If the subprogram is marked Inline_Always, then even if it returns
6245 -- an unconstrained type the call does not require use of the secondary
6246 -- stack. However, inlining will only take place if the body to inline
6247 -- is already present. It may not be available if e.g. the subprogram is
6248 -- declared in a child instance.
6250 -- If this is an initialization call for a type whose construction
6251 -- uses the secondary stack, and it is not a nested call to initialize
6252 -- a component, we do need to create a transient scope for it. We
6253 -- check for this by traversing the type in Check_Initialization_Call.
6255 if Is_Inlined (Nam)
6256 and then Has_Pragma_Inline (Nam)
6257 and then Nkind (Unit_Declaration_Node (Nam)) = N_Subprogram_Declaration
6258 and then Present (Body_To_Inline (Unit_Declaration_Node (Nam)))
6259 then
6260 null;
6262 elsif Ekind (Nam) = E_Enumeration_Literal
6263 or else Is_Build_In_Place_Function (Nam)
6264 or else Is_Intrinsic_Subprogram (Nam)
6265 then
6266 null;
6268 elsif Expander_Active
6269 and then Is_Type (Etype (Nam))
6270 and then Requires_Transient_Scope (Etype (Nam))
6271 and then
6272 (not Within_Init_Proc
6273 or else
6274 (not Is_Init_Proc (Nam) and then Ekind (Nam) /= E_Function))
6275 then
6276 Establish_Transient_Scope (N, Sec_Stack => True);
6278 -- If the call appears within the bounds of a loop, it will
6279 -- be rewritten and reanalyzed, nothing left to do here.
6281 if Nkind (N) /= N_Function_Call then
6282 return;
6283 end if;
6285 elsif Is_Init_Proc (Nam)
6286 and then not Within_Init_Proc
6287 then
6288 Check_Initialization_Call (N, Nam);
6289 end if;
6291 -- A protected function cannot be called within the definition of the
6292 -- enclosing protected type, unless it is part of a pre/postcondition
6293 -- on another protected operation.
6295 if Is_Protected_Type (Scope (Nam))
6296 and then In_Open_Scopes (Scope (Nam))
6297 and then not Has_Completion (Scope (Nam))
6298 and then not In_Spec_Expression
6299 then
6300 Error_Msg_NE
6301 ("& cannot be called before end of protected definition", N, Nam);
6302 end if;
6304 -- Propagate interpretation to actuals, and add default expressions
6305 -- where needed.
6307 if Present (First_Formal (Nam)) then
6308 Resolve_Actuals (N, Nam);
6310 -- Overloaded literals are rewritten as function calls, for purpose of
6311 -- resolution. After resolution, we can replace the call with the
6312 -- literal itself.
6314 elsif Ekind (Nam) = E_Enumeration_Literal then
6315 Copy_Node (Subp, N);
6316 Resolve_Entity_Name (N, Typ);
6318 -- Avoid validation, since it is a static function call
6320 Generate_Reference (Nam, Subp);
6321 return;
6322 end if;
6324 -- If the subprogram is not global, then kill all saved values and
6325 -- checks. This is a bit conservative, since in many cases we could do
6326 -- better, but it is not worth the effort. Similarly, we kill constant
6327 -- values. However we do not need to do this for internal entities
6328 -- (unless they are inherited user-defined subprograms), since they
6329 -- are not in the business of molesting local values.
6331 -- If the flag Suppress_Value_Tracking_On_Calls is set, then we also
6332 -- kill all checks and values for calls to global subprograms. This
6333 -- takes care of the case where an access to a local subprogram is
6334 -- taken, and could be passed directly or indirectly and then called
6335 -- from almost any context.
6337 -- Note: we do not do this step till after resolving the actuals. That
6338 -- way we still take advantage of the current value information while
6339 -- scanning the actuals.
6341 -- We suppress killing values if we are processing the nodes associated
6342 -- with N_Freeze_Entity nodes. Otherwise the declaration of a tagged
6343 -- type kills all the values as part of analyzing the code that
6344 -- initializes the dispatch tables.
6346 if Inside_Freezing_Actions = 0
6347 and then (not Is_Library_Level_Entity (Nam)
6348 or else Suppress_Value_Tracking_On_Call
6349 (Nearest_Dynamic_Scope (Current_Scope)))
6350 and then (Comes_From_Source (Nam)
6351 or else (Present (Alias (Nam))
6352 and then Comes_From_Source (Alias (Nam))))
6353 then
6354 Kill_Current_Values;
6355 end if;
6357 -- If we are warning about unread OUT parameters, this is the place to
6358 -- set Last_Assignment for OUT and IN OUT parameters. We have to do this
6359 -- after the above call to Kill_Current_Values (since that call clears
6360 -- the Last_Assignment field of all local variables).
6362 if (Warn_On_Modified_Unread or Warn_On_All_Unread_Out_Parameters)
6363 and then Comes_From_Source (N)
6364 and then In_Extended_Main_Source_Unit (N)
6365 then
6366 declare
6367 F : Entity_Id;
6368 A : Node_Id;
6370 begin
6371 F := First_Formal (Nam);
6372 A := First_Actual (N);
6373 while Present (F) and then Present (A) loop
6374 if Ekind_In (F, E_Out_Parameter, E_In_Out_Parameter)
6375 and then Warn_On_Modified_As_Out_Parameter (F)
6376 and then Is_Entity_Name (A)
6377 and then Present (Entity (A))
6378 and then Comes_From_Source (N)
6379 and then Safe_To_Capture_Value (N, Entity (A))
6380 then
6381 Set_Last_Assignment (Entity (A), A);
6382 end if;
6384 Next_Formal (F);
6385 Next_Actual (A);
6386 end loop;
6387 end;
6388 end if;
6390 -- If the subprogram is a primitive operation, check whether or not
6391 -- it is a correct dispatching call.
6393 if Is_Overloadable (Nam)
6394 and then Is_Dispatching_Operation (Nam)
6395 then
6396 Check_Dispatching_Call (N);
6398 elsif Ekind (Nam) /= E_Subprogram_Type
6399 and then Is_Abstract_Subprogram (Nam)
6400 and then not In_Instance
6401 then
6402 Error_Msg_NE ("cannot call abstract subprogram &!", N, Nam);
6403 end if;
6405 -- If this is a dispatching call, generate the appropriate reference,
6406 -- for better source navigation in GPS.
6408 if Is_Overloadable (Nam)
6409 and then Present (Controlling_Argument (N))
6410 then
6411 Generate_Reference (Nam, Subp, 'R');
6413 -- Normal case, not a dispatching call: generate a call reference
6415 else
6416 Generate_Reference (Nam, Subp, 's');
6417 end if;
6419 if Is_Intrinsic_Subprogram (Nam) then
6420 Check_Intrinsic_Call (N);
6421 end if;
6423 -- Check for violation of restriction No_Specific_Termination_Handlers
6424 -- and warn on a potentially blocking call to Abort_Task.
6426 if Restriction_Check_Required (No_Specific_Termination_Handlers)
6427 and then (Is_RTE (Nam, RE_Set_Specific_Handler)
6428 or else
6429 Is_RTE (Nam, RE_Specific_Handler))
6430 then
6431 Check_Restriction (No_Specific_Termination_Handlers, N);
6433 elsif Is_RTE (Nam, RE_Abort_Task) then
6434 Check_Potentially_Blocking_Operation (N);
6435 end if;
6437 -- A call to Ada.Real_Time.Timing_Events.Set_Handler to set a relative
6438 -- timing event violates restriction No_Relative_Delay (AI-0211). We
6439 -- need to check the second argument to determine whether it is an
6440 -- absolute or relative timing event.
6442 if Restriction_Check_Required (No_Relative_Delay)
6443 and then Is_RTE (Nam, RE_Set_Handler)
6444 and then Is_RTE (Etype (Next_Actual (First_Actual (N))), RE_Time_Span)
6445 then
6446 Check_Restriction (No_Relative_Delay, N);
6447 end if;
6449 -- Issue an error for a call to an eliminated subprogram. This routine
6450 -- will not perform the check if the call appears within a default
6451 -- expression.
6453 Check_For_Eliminated_Subprogram (Subp, Nam);
6455 -- In formal mode, the primitive operations of a tagged type or type
6456 -- extension do not include functions that return the tagged type.
6458 if Nkind (N) = N_Function_Call
6459 and then Is_Tagged_Type (Etype (N))
6460 and then Is_Entity_Name (Name (N))
6461 and then Is_Inherited_Operation_For_Type (Entity (Name (N)), Etype (N))
6462 then
6463 Check_SPARK_05_Restriction ("function not inherited", N);
6464 end if;
6466 -- Implement rule in 12.5.1 (23.3/2): In an instance, if the actual is
6467 -- class-wide and the call dispatches on result in a context that does
6468 -- not provide a tag, the call raises Program_Error.
6470 if Nkind (N) = N_Function_Call
6471 and then In_Instance
6472 and then Is_Generic_Actual_Type (Typ)
6473 and then Is_Class_Wide_Type (Typ)
6474 and then Has_Controlling_Result (Nam)
6475 and then Nkind (Parent (N)) = N_Object_Declaration
6476 then
6477 -- Verify that none of the formals are controlling
6479 declare
6480 Call_OK : Boolean := False;
6481 F : Entity_Id;
6483 begin
6484 F := First_Formal (Nam);
6485 while Present (F) loop
6486 if Is_Controlling_Formal (F) then
6487 Call_OK := True;
6488 exit;
6489 end if;
6491 Next_Formal (F);
6492 end loop;
6494 if not Call_OK then
6495 Error_Msg_Warn := SPARK_Mode /= On;
6496 Error_Msg_N ("!cannot determine tag of result<<", N);
6497 Error_Msg_N ("\Program_Error [<<!", N);
6498 Insert_Action (N,
6499 Make_Raise_Program_Error (Sloc (N),
6500 Reason => PE_Explicit_Raise));
6501 end if;
6502 end;
6503 end if;
6505 -- Check for calling a function with OUT or IN OUT parameter when the
6506 -- calling context (us right now) is not Ada 2012, so does not allow
6507 -- OUT or IN OUT parameters in function calls.
6509 if Ada_Version < Ada_2012
6510 and then Ekind (Nam) = E_Function
6511 and then Has_Out_Or_In_Out_Parameter (Nam)
6512 then
6513 Error_Msg_NE ("& has at least one OUT or `IN OUT` parameter", N, Nam);
6514 Error_Msg_N ("\call to this function only allowed in Ada 2012", N);
6515 end if;
6517 -- Check the dimensions of the actuals in the call. For function calls,
6518 -- propagate the dimensions from the returned type to N.
6520 Analyze_Dimension_Call (N, Nam);
6522 -- All done, evaluate call and deal with elaboration issues
6524 Eval_Call (N);
6525 Check_Elab_Call (N);
6527 -- In GNATprove mode, expansion is disabled, but we want to inline some
6528 -- subprograms to facilitate formal verification. Indirect calls through
6529 -- a subprogram type or within a generic cannot be inlined. Inlining is
6530 -- performed only for calls subject to SPARK_Mode on.
6532 if GNATprove_Mode
6533 and then SPARK_Mode = On
6534 and then Is_Overloadable (Nam)
6535 and then not Inside_A_Generic
6536 then
6537 Nam_UA := Ultimate_Alias (Nam);
6538 Nam_Decl := Unit_Declaration_Node (Nam_UA);
6540 if Nkind (Nam_Decl) = N_Subprogram_Declaration then
6541 Body_Id := Corresponding_Body (Nam_Decl);
6543 -- Nothing to do if the subprogram is not eligible for inlining in
6544 -- GNATprove mode.
6546 if not Is_Inlined_Always (Nam_UA)
6547 or else not Can_Be_Inlined_In_GNATprove_Mode (Nam_UA, Body_Id)
6548 then
6549 null;
6551 -- Calls cannot be inlined inside assertions, as GNATprove treats
6552 -- assertions as logic expressions.
6554 elsif In_Assertion_Expr /= 0 then
6555 Error_Msg_NE ("?no contextual analysis of &", N, Nam);
6556 Error_Msg_N ("\call appears in assertion expression", N);
6557 Set_Is_Inlined_Always (Nam_UA, False);
6559 -- Calls cannot be inlined inside default expressions
6561 elsif In_Default_Expr then
6562 Error_Msg_NE ("?no contextual analysis of &", N, Nam);
6563 Error_Msg_N ("\call appears in default expression", N);
6564 Set_Is_Inlined_Always (Nam_UA, False);
6566 -- Inlining should not be performed during pre-analysis
6568 elsif Full_Analysis then
6570 -- With the one-pass inlining technique, a call cannot be
6571 -- inlined if the corresponding body has not been seen yet.
6573 if No (Body_Id) then
6574 Error_Msg_NE
6575 ("?no contextual analysis of & (body not seen yet)",
6576 N, Nam);
6577 Set_Is_Inlined_Always (Nam_UA, False);
6579 -- Nothing to do if there is no body to inline, indicating that
6580 -- the subprogram is not suitable for inlining in GNATprove
6581 -- mode.
6583 elsif No (Body_To_Inline (Nam_Decl)) then
6584 null;
6586 -- Calls cannot be inlined inside potentially unevaluated
6587 -- expressions, as this would create complex actions inside
6588 -- expressions, that are not handled by GNATprove.
6590 elsif Is_Potentially_Unevaluated (N) then
6591 Error_Msg_NE ("?no contextual analysis of &", N, Nam);
6592 Error_Msg_N
6593 ("\call appears in potentially unevaluated context", N);
6594 Set_Is_Inlined_Always (Nam_UA, False);
6596 -- Otherwise, inline the call
6598 else
6599 Expand_Inlined_Call (N, Nam_UA, Nam);
6600 end if;
6601 end if;
6602 end if;
6603 end if;
6605 Warn_On_Overlapping_Actuals (Nam, N);
6606 end Resolve_Call;
6608 -----------------------------
6609 -- Resolve_Case_Expression --
6610 -----------------------------
6612 procedure Resolve_Case_Expression (N : Node_Id; Typ : Entity_Id) is
6613 Alt : Node_Id;
6615 begin
6616 Alt := First (Alternatives (N));
6617 while Present (Alt) loop
6618 Resolve (Expression (Alt), Typ);
6619 Next (Alt);
6620 end loop;
6622 Set_Etype (N, Typ);
6623 Eval_Case_Expression (N);
6624 end Resolve_Case_Expression;
6626 -------------------------------
6627 -- Resolve_Character_Literal --
6628 -------------------------------
6630 procedure Resolve_Character_Literal (N : Node_Id; Typ : Entity_Id) is
6631 B_Typ : constant Entity_Id := Base_Type (Typ);
6632 C : Entity_Id;
6634 begin
6635 -- Verify that the character does belong to the type of the context
6637 Set_Etype (N, B_Typ);
6638 Eval_Character_Literal (N);
6640 -- Wide_Wide_Character literals must always be defined, since the set
6641 -- of wide wide character literals is complete, i.e. if a character
6642 -- literal is accepted by the parser, then it is OK for wide wide
6643 -- character (out of range character literals are rejected).
6645 if Root_Type (B_Typ) = Standard_Wide_Wide_Character then
6646 return;
6648 -- Always accept character literal for type Any_Character, which
6649 -- occurs in error situations and in comparisons of literals, both
6650 -- of which should accept all literals.
6652 elsif B_Typ = Any_Character then
6653 return;
6655 -- For Standard.Character or a type derived from it, check that the
6656 -- literal is in range.
6658 elsif Root_Type (B_Typ) = Standard_Character then
6659 if In_Character_Range (UI_To_CC (Char_Literal_Value (N))) then
6660 return;
6661 end if;
6663 -- For Standard.Wide_Character or a type derived from it, check that the
6664 -- literal is in range.
6666 elsif Root_Type (B_Typ) = Standard_Wide_Character then
6667 if In_Wide_Character_Range (UI_To_CC (Char_Literal_Value (N))) then
6668 return;
6669 end if;
6671 -- For Standard.Wide_Wide_Character or a type derived from it, we
6672 -- know the literal is in range, since the parser checked.
6674 elsif Root_Type (B_Typ) = Standard_Wide_Wide_Character then
6675 return;
6677 -- If the entity is already set, this has already been resolved in a
6678 -- generic context, or comes from expansion. Nothing else to do.
6680 elsif Present (Entity (N)) then
6681 return;
6683 -- Otherwise we have a user defined character type, and we can use the
6684 -- standard visibility mechanisms to locate the referenced entity.
6686 else
6687 C := Current_Entity (N);
6688 while Present (C) loop
6689 if Etype (C) = B_Typ then
6690 Set_Entity_With_Checks (N, C);
6691 Generate_Reference (C, N);
6692 return;
6693 end if;
6695 C := Homonym (C);
6696 end loop;
6697 end if;
6699 -- If we fall through, then the literal does not match any of the
6700 -- entries of the enumeration type. This isn't just a constraint error
6701 -- situation, it is an illegality (see RM 4.2).
6703 Error_Msg_NE
6704 ("character not defined for }", N, First_Subtype (B_Typ));
6705 end Resolve_Character_Literal;
6707 ---------------------------
6708 -- Resolve_Comparison_Op --
6709 ---------------------------
6711 -- Context requires a boolean type, and plays no role in resolution.
6712 -- Processing identical to that for equality operators. The result type is
6713 -- the base type, which matters when pathological subtypes of booleans with
6714 -- limited ranges are used.
6716 procedure Resolve_Comparison_Op (N : Node_Id; Typ : Entity_Id) is
6717 L : constant Node_Id := Left_Opnd (N);
6718 R : constant Node_Id := Right_Opnd (N);
6719 T : Entity_Id;
6721 begin
6722 -- If this is an intrinsic operation which is not predefined, use the
6723 -- types of its declared arguments to resolve the possibly overloaded
6724 -- operands. Otherwise the operands are unambiguous and specify the
6725 -- expected type.
6727 if Scope (Entity (N)) /= Standard_Standard then
6728 T := Etype (First_Entity (Entity (N)));
6730 else
6731 T := Find_Unique_Type (L, R);
6733 if T = Any_Fixed then
6734 T := Unique_Fixed_Point_Type (L);
6735 end if;
6736 end if;
6738 Set_Etype (N, Base_Type (Typ));
6739 Generate_Reference (T, N, ' ');
6741 -- Skip remaining processing if already set to Any_Type
6743 if T = Any_Type then
6744 return;
6745 end if;
6747 -- Deal with other error cases
6749 if T = Any_String or else
6750 T = Any_Composite or else
6751 T = Any_Character
6752 then
6753 if T = Any_Character then
6754 Ambiguous_Character (L);
6755 else
6756 Error_Msg_N ("ambiguous operands for comparison", N);
6757 end if;
6759 Set_Etype (N, Any_Type);
6760 return;
6761 end if;
6763 -- Resolve the operands if types OK
6765 Resolve (L, T);
6766 Resolve (R, T);
6767 Check_Unset_Reference (L);
6768 Check_Unset_Reference (R);
6769 Generate_Operator_Reference (N, T);
6770 Check_Low_Bound_Tested (N);
6772 -- In SPARK, ordering operators <, <=, >, >= are not defined for Boolean
6773 -- types or array types except String.
6775 if Is_Boolean_Type (T) then
6776 Check_SPARK_05_Restriction
6777 ("comparison is not defined on Boolean type", N);
6779 elsif Is_Array_Type (T)
6780 and then Base_Type (T) /= Standard_String
6781 then
6782 Check_SPARK_05_Restriction
6783 ("comparison is not defined on array types other than String", N);
6784 end if;
6786 -- Check comparison on unordered enumeration
6788 if Bad_Unordered_Enumeration_Reference (N, Etype (L)) then
6789 Error_Msg_Sloc := Sloc (Etype (L));
6790 Error_Msg_NE
6791 ("comparison on unordered enumeration type& declared#?U?",
6792 N, Etype (L));
6793 end if;
6795 -- Evaluate the relation (note we do this after the above check since
6796 -- this Eval call may change N to True/False.
6798 Analyze_Dimension (N);
6799 Eval_Relational_Op (N);
6800 end Resolve_Comparison_Op;
6802 -----------------------------------------
6803 -- Resolve_Discrete_Subtype_Indication --
6804 -----------------------------------------
6806 procedure Resolve_Discrete_Subtype_Indication
6807 (N : Node_Id;
6808 Typ : Entity_Id)
6810 R : Node_Id;
6811 S : Entity_Id;
6813 begin
6814 Analyze (Subtype_Mark (N));
6815 S := Entity (Subtype_Mark (N));
6817 if Nkind (Constraint (N)) /= N_Range_Constraint then
6818 Error_Msg_N ("expect range constraint for discrete type", N);
6819 Set_Etype (N, Any_Type);
6821 else
6822 R := Range_Expression (Constraint (N));
6824 if R = Error then
6825 return;
6826 end if;
6828 Analyze (R);
6830 if Base_Type (S) /= Base_Type (Typ) then
6831 Error_Msg_NE
6832 ("expect subtype of }", N, First_Subtype (Typ));
6834 -- Rewrite the constraint as a range of Typ
6835 -- to allow compilation to proceed further.
6837 Set_Etype (N, Typ);
6838 Rewrite (Low_Bound (R),
6839 Make_Attribute_Reference (Sloc (Low_Bound (R)),
6840 Prefix => New_Occurrence_Of (Typ, Sloc (R)),
6841 Attribute_Name => Name_First));
6842 Rewrite (High_Bound (R),
6843 Make_Attribute_Reference (Sloc (High_Bound (R)),
6844 Prefix => New_Occurrence_Of (Typ, Sloc (R)),
6845 Attribute_Name => Name_First));
6847 else
6848 Resolve (R, Typ);
6849 Set_Etype (N, Etype (R));
6851 -- Additionally, we must check that the bounds are compatible
6852 -- with the given subtype, which might be different from the
6853 -- type of the context.
6855 Apply_Range_Check (R, S);
6857 -- ??? If the above check statically detects a Constraint_Error
6858 -- it replaces the offending bound(s) of the range R with a
6859 -- Constraint_Error node. When the itype which uses these bounds
6860 -- is frozen the resulting call to Duplicate_Subexpr generates
6861 -- a new temporary for the bounds.
6863 -- Unfortunately there are other itypes that are also made depend
6864 -- on these bounds, so when Duplicate_Subexpr is called they get
6865 -- a forward reference to the newly created temporaries and Gigi
6866 -- aborts on such forward references. This is probably sign of a
6867 -- more fundamental problem somewhere else in either the order of
6868 -- itype freezing or the way certain itypes are constructed.
6870 -- To get around this problem we call Remove_Side_Effects right
6871 -- away if either bounds of R are a Constraint_Error.
6873 declare
6874 L : constant Node_Id := Low_Bound (R);
6875 H : constant Node_Id := High_Bound (R);
6877 begin
6878 if Nkind (L) = N_Raise_Constraint_Error then
6879 Remove_Side_Effects (L);
6880 end if;
6882 if Nkind (H) = N_Raise_Constraint_Error then
6883 Remove_Side_Effects (H);
6884 end if;
6885 end;
6887 Check_Unset_Reference (Low_Bound (R));
6888 Check_Unset_Reference (High_Bound (R));
6889 end if;
6890 end if;
6891 end Resolve_Discrete_Subtype_Indication;
6893 -------------------------
6894 -- Resolve_Entity_Name --
6895 -------------------------
6897 -- Used to resolve identifiers and expanded names
6899 procedure Resolve_Entity_Name (N : Node_Id; Typ : Entity_Id) is
6900 function Is_OK_Volatile_Context
6901 (Context : Node_Id;
6902 Obj_Ref : Node_Id) return Boolean;
6903 -- Determine whether node Context denotes a "non-interfering context"
6904 -- (as defined in SPARK RM 7.1.3(13)) where volatile reference Obj_Ref
6905 -- can safely reside.
6907 ----------------------------
6908 -- Is_OK_Volatile_Context --
6909 ----------------------------
6911 function Is_OK_Volatile_Context
6912 (Context : Node_Id;
6913 Obj_Ref : Node_Id) return Boolean
6915 function Within_Check (Nod : Node_Id) return Boolean;
6916 -- Determine whether an arbitrary node appears in a check node
6918 function Within_Procedure_Call (Nod : Node_Id) return Boolean;
6919 -- Determine whether an arbitrary node appears in a procedure call
6921 ------------------
6922 -- Within_Check --
6923 ------------------
6925 function Within_Check (Nod : Node_Id) return Boolean is
6926 Par : Node_Id;
6928 begin
6929 -- Climb the parent chain looking for a check node
6931 Par := Nod;
6932 while Present (Par) loop
6933 if Nkind (Par) in N_Raise_xxx_Error then
6934 return True;
6936 -- Prevent the search from going too far
6938 elsif Is_Body_Or_Package_Declaration (Par) then
6939 exit;
6940 end if;
6942 Par := Parent (Par);
6943 end loop;
6945 return False;
6946 end Within_Check;
6948 ---------------------------
6949 -- Within_Procedure_Call --
6950 ---------------------------
6952 function Within_Procedure_Call (Nod : Node_Id) return Boolean is
6953 Par : Node_Id;
6955 begin
6956 -- Climb the parent chain looking for a procedure call
6958 Par := Nod;
6959 while Present (Par) loop
6960 if Nkind (Par) = N_Procedure_Call_Statement then
6961 return True;
6963 -- Prevent the search from going too far
6965 elsif Is_Body_Or_Package_Declaration (Par) then
6966 exit;
6967 end if;
6969 Par := Parent (Par);
6970 end loop;
6972 return False;
6973 end Within_Procedure_Call;
6975 -- Start of processing for Is_OK_Volatile_Context
6977 begin
6978 -- The volatile object appears on either side of an assignment
6980 if Nkind (Context) = N_Assignment_Statement then
6981 return True;
6983 -- The volatile object is part of the initialization expression of
6984 -- another object. Ensure that the climb of the parent chain came
6985 -- from the expression side and not from the name side.
6987 elsif Nkind (Context) = N_Object_Declaration
6988 and then Present (Expression (Context))
6989 and then Expression (Context) = Obj_Ref
6990 then
6991 return True;
6993 -- The volatile object appears as an actual parameter in a call to an
6994 -- instance of Unchecked_Conversion whose result is renamed.
6996 elsif Nkind (Context) = N_Function_Call
6997 and then Is_Unchecked_Conversion_Instance (Entity (Name (Context)))
6998 and then Nkind (Parent (Context)) = N_Object_Renaming_Declaration
6999 then
7000 return True;
7002 -- The volatile object appears as the prefix of a name occurring
7003 -- in a non-interfering context.
7005 elsif Nkind_In (Context, N_Attribute_Reference,
7006 N_Indexed_Component,
7007 N_Selected_Component,
7008 N_Slice)
7009 and then Prefix (Context) = Obj_Ref
7010 and then Is_OK_Volatile_Context
7011 (Context => Parent (Context),
7012 Obj_Ref => Context)
7013 then
7014 return True;
7016 -- The volatile object appears as the expression of a type conversion
7017 -- occurring in a non-interfering context.
7019 elsif Nkind_In (Context, N_Type_Conversion,
7020 N_Unchecked_Type_Conversion)
7021 and then Expression (Context) = Obj_Ref
7022 and then Is_OK_Volatile_Context
7023 (Context => Parent (Context),
7024 Obj_Ref => Context)
7025 then
7026 return True;
7028 -- Allow references to volatile objects in various checks. This is
7029 -- not a direct SPARK 2014 requirement.
7031 elsif Within_Check (Context) then
7032 return True;
7034 -- Assume that references to effectively volatile objects that appear
7035 -- as actual parameters in a procedure call are always legal. A full
7036 -- legality check is done when the actuals are resolved.
7038 elsif Within_Procedure_Call (Context) then
7039 return True;
7041 -- Otherwise the context is not suitable for an effectively volatile
7042 -- object.
7044 else
7045 return False;
7046 end if;
7047 end Is_OK_Volatile_Context;
7049 -- Local variables
7051 E : constant Entity_Id := Entity (N);
7052 Par : Node_Id;
7054 -- Start of processing for Resolve_Entity_Name
7056 begin
7057 -- If garbage from errors, set to Any_Type and return
7059 if No (E) and then Total_Errors_Detected /= 0 then
7060 Set_Etype (N, Any_Type);
7061 return;
7062 end if;
7064 -- Replace named numbers by corresponding literals. Note that this is
7065 -- the one case where Resolve_Entity_Name must reset the Etype, since
7066 -- it is currently marked as universal.
7068 if Ekind (E) = E_Named_Integer then
7069 Set_Etype (N, Typ);
7070 Eval_Named_Integer (N);
7072 elsif Ekind (E) = E_Named_Real then
7073 Set_Etype (N, Typ);
7074 Eval_Named_Real (N);
7076 -- For enumeration literals, we need to make sure that a proper style
7077 -- check is done, since such literals are overloaded, and thus we did
7078 -- not do a style check during the first phase of analysis.
7080 elsif Ekind (E) = E_Enumeration_Literal then
7081 Set_Entity_With_Checks (N, E);
7082 Eval_Entity_Name (N);
7084 -- Case of subtype name appearing as an operand in expression
7086 elsif Is_Type (E) then
7088 -- Allow use of subtype if it is a concurrent type where we are
7089 -- currently inside the body. This will eventually be expanded into a
7090 -- call to Self (for tasks) or _object (for protected objects). Any
7091 -- other use of a subtype is invalid.
7093 if Is_Concurrent_Type (E)
7094 and then In_Open_Scopes (E)
7095 then
7096 null;
7098 -- Any other use is an error
7100 else
7101 Error_Msg_N
7102 ("invalid use of subtype mark in expression or call", N);
7103 end if;
7105 -- Check discriminant use if entity is discriminant in current scope,
7106 -- i.e. discriminant of record or concurrent type currently being
7107 -- analyzed. Uses in corresponding body are unrestricted.
7109 elsif Ekind (E) = E_Discriminant
7110 and then Scope (E) = Current_Scope
7111 and then not Has_Completion (Current_Scope)
7112 then
7113 Check_Discriminant_Use (N);
7115 -- A parameterless generic function cannot appear in a context that
7116 -- requires resolution.
7118 elsif Ekind (E) = E_Generic_Function then
7119 Error_Msg_N ("illegal use of generic function", N);
7121 elsif Ekind (E) = E_Out_Parameter
7122 and then Ada_Version = Ada_83
7123 and then (Nkind (Parent (N)) in N_Op
7124 or else (Nkind (Parent (N)) = N_Assignment_Statement
7125 and then N = Expression (Parent (N)))
7126 or else Nkind (Parent (N)) = N_Explicit_Dereference)
7127 then
7128 Error_Msg_N ("(Ada 83) illegal reading of out parameter", N);
7130 -- In all other cases, just do the possible static evaluation
7132 else
7133 -- A deferred constant that appears in an expression must have a
7134 -- completion, unless it has been removed by in-place expansion of
7135 -- an aggregate.
7137 if Ekind (E) = E_Constant
7138 and then Comes_From_Source (E)
7139 and then No (Constant_Value (E))
7140 and then Is_Frozen (Etype (E))
7141 and then not In_Spec_Expression
7142 and then not Is_Imported (E)
7143 then
7144 if No_Initialization (Parent (E))
7145 or else (Present (Full_View (E))
7146 and then No_Initialization (Parent (Full_View (E))))
7147 then
7148 null;
7149 else
7150 Error_Msg_N (
7151 "deferred constant is frozen before completion", N);
7152 end if;
7153 end if;
7155 Eval_Entity_Name (N);
7156 end if;
7158 Par := Parent (N);
7160 -- When the entity appears in a parameter association, retrieve the
7161 -- related subprogram call.
7163 if Nkind (Par) = N_Parameter_Association then
7164 Par := Parent (Par);
7165 end if;
7167 -- The following checks are only relevant when SPARK_Mode is on as they
7168 -- are not standard Ada legality rules. An effectively volatile object
7169 -- subject to enabled properties Async_Writers or Effective_Reads must
7170 -- appear in a specific context.
7172 if SPARK_Mode = On
7173 and then Is_Object (E)
7174 and then Is_Effectively_Volatile (E)
7175 and then (Async_Writers_Enabled (E)
7176 or else Effective_Reads_Enabled (E))
7177 and then Comes_From_Source (N)
7178 then
7179 -- The effectively volatile objects appears in a "non-interfering
7180 -- context" as defined in SPARK RM 7.1.3(13).
7182 if Is_OK_Volatile_Context (Par, N) then
7183 null;
7185 -- Otherwise the context causes a side effect with respect to the
7186 -- effectively volatile object.
7188 else
7189 SPARK_Msg_N
7190 ("volatile object cannot appear in this context "
7191 & "(SPARK RM 7.1.3(13))", N);
7192 end if;
7193 end if;
7195 -- A Ghost entity must appear in a specific context
7197 if Is_Ghost_Entity (E) and then Comes_From_Source (N) then
7198 Check_Ghost_Context (E, N);
7199 end if;
7201 -- In SPARK mode, need to check possible elaboration issues
7203 if SPARK_Mode = On and then Ekind (E) = E_Variable then
7204 Check_Elab_Call (N);
7205 end if;
7206 end Resolve_Entity_Name;
7208 -------------------
7209 -- Resolve_Entry --
7210 -------------------
7212 procedure Resolve_Entry (Entry_Name : Node_Id) is
7213 Loc : constant Source_Ptr := Sloc (Entry_Name);
7214 Nam : Entity_Id;
7215 New_N : Node_Id;
7216 S : Entity_Id;
7217 Tsk : Entity_Id;
7218 E_Name : Node_Id;
7219 Index : Node_Id;
7221 function Actual_Index_Type (E : Entity_Id) return Entity_Id;
7222 -- If the bounds of the entry family being called depend on task
7223 -- discriminants, build a new index subtype where a discriminant is
7224 -- replaced with the value of the discriminant of the target task.
7225 -- The target task is the prefix of the entry name in the call.
7227 -----------------------
7228 -- Actual_Index_Type --
7229 -----------------------
7231 function Actual_Index_Type (E : Entity_Id) return Entity_Id is
7232 Typ : constant Entity_Id := Entry_Index_Type (E);
7233 Tsk : constant Entity_Id := Scope (E);
7234 Lo : constant Node_Id := Type_Low_Bound (Typ);
7235 Hi : constant Node_Id := Type_High_Bound (Typ);
7236 New_T : Entity_Id;
7238 function Actual_Discriminant_Ref (Bound : Node_Id) return Node_Id;
7239 -- If the bound is given by a discriminant, replace with a reference
7240 -- to the discriminant of the same name in the target task. If the
7241 -- entry name is the target of a requeue statement and the entry is
7242 -- in the current protected object, the bound to be used is the
7243 -- discriminal of the object (see Apply_Range_Checks for details of
7244 -- the transformation).
7246 -----------------------------
7247 -- Actual_Discriminant_Ref --
7248 -----------------------------
7250 function Actual_Discriminant_Ref (Bound : Node_Id) return Node_Id is
7251 Typ : constant Entity_Id := Etype (Bound);
7252 Ref : Node_Id;
7254 begin
7255 Remove_Side_Effects (Bound);
7257 if not Is_Entity_Name (Bound)
7258 or else Ekind (Entity (Bound)) /= E_Discriminant
7259 then
7260 return Bound;
7262 elsif Is_Protected_Type (Tsk)
7263 and then In_Open_Scopes (Tsk)
7264 and then Nkind (Parent (Entry_Name)) = N_Requeue_Statement
7265 then
7266 -- Note: here Bound denotes a discriminant of the corresponding
7267 -- record type tskV, whose discriminal is a formal of the
7268 -- init-proc tskVIP. What we want is the body discriminal,
7269 -- which is associated to the discriminant of the original
7270 -- concurrent type tsk.
7272 return New_Occurrence_Of
7273 (Find_Body_Discriminal (Entity (Bound)), Loc);
7275 else
7276 Ref :=
7277 Make_Selected_Component (Loc,
7278 Prefix => New_Copy_Tree (Prefix (Prefix (Entry_Name))),
7279 Selector_Name => New_Occurrence_Of (Entity (Bound), Loc));
7280 Analyze (Ref);
7281 Resolve (Ref, Typ);
7282 return Ref;
7283 end if;
7284 end Actual_Discriminant_Ref;
7286 -- Start of processing for Actual_Index_Type
7288 begin
7289 if not Has_Discriminants (Tsk)
7290 or else (not Is_Entity_Name (Lo) and then not Is_Entity_Name (Hi))
7291 then
7292 return Entry_Index_Type (E);
7294 else
7295 New_T := Create_Itype (Ekind (Typ), Parent (Entry_Name));
7296 Set_Etype (New_T, Base_Type (Typ));
7297 Set_Size_Info (New_T, Typ);
7298 Set_RM_Size (New_T, RM_Size (Typ));
7299 Set_Scalar_Range (New_T,
7300 Make_Range (Sloc (Entry_Name),
7301 Low_Bound => Actual_Discriminant_Ref (Lo),
7302 High_Bound => Actual_Discriminant_Ref (Hi)));
7304 return New_T;
7305 end if;
7306 end Actual_Index_Type;
7308 -- Start of processing of Resolve_Entry
7310 begin
7311 -- Find name of entry being called, and resolve prefix of name with its
7312 -- own type. The prefix can be overloaded, and the name and signature of
7313 -- the entry must be taken into account.
7315 if Nkind (Entry_Name) = N_Indexed_Component then
7317 -- Case of dealing with entry family within the current tasks
7319 E_Name := Prefix (Entry_Name);
7321 else
7322 E_Name := Entry_Name;
7323 end if;
7325 if Is_Entity_Name (E_Name) then
7327 -- Entry call to an entry (or entry family) in the current task. This
7328 -- is legal even though the task will deadlock. Rewrite as call to
7329 -- current task.
7331 -- This can also be a call to an entry in an enclosing task. If this
7332 -- is a single task, we have to retrieve its name, because the scope
7333 -- of the entry is the task type, not the object. If the enclosing
7334 -- task is a task type, the identity of the task is given by its own
7335 -- self variable.
7337 -- Finally this can be a requeue on an entry of the same task or
7338 -- protected object.
7340 S := Scope (Entity (E_Name));
7342 for J in reverse 0 .. Scope_Stack.Last loop
7343 if Is_Task_Type (Scope_Stack.Table (J).Entity)
7344 and then not Comes_From_Source (S)
7345 then
7346 -- S is an enclosing task or protected object. The concurrent
7347 -- declaration has been converted into a type declaration, and
7348 -- the object itself has an object declaration that follows
7349 -- the type in the same declarative part.
7351 Tsk := Next_Entity (S);
7352 while Etype (Tsk) /= S loop
7353 Next_Entity (Tsk);
7354 end loop;
7356 S := Tsk;
7357 exit;
7359 elsif S = Scope_Stack.Table (J).Entity then
7361 -- Call to current task. Will be transformed into call to Self
7363 exit;
7365 end if;
7366 end loop;
7368 New_N :=
7369 Make_Selected_Component (Loc,
7370 Prefix => New_Occurrence_Of (S, Loc),
7371 Selector_Name =>
7372 New_Occurrence_Of (Entity (E_Name), Loc));
7373 Rewrite (E_Name, New_N);
7374 Analyze (E_Name);
7376 elsif Nkind (Entry_Name) = N_Selected_Component
7377 and then Is_Overloaded (Prefix (Entry_Name))
7378 then
7379 -- Use the entry name (which must be unique at this point) to find
7380 -- the prefix that returns the corresponding task/protected type.
7382 declare
7383 Pref : constant Node_Id := Prefix (Entry_Name);
7384 Ent : constant Entity_Id := Entity (Selector_Name (Entry_Name));
7385 I : Interp_Index;
7386 It : Interp;
7388 begin
7389 Get_First_Interp (Pref, I, It);
7390 while Present (It.Typ) loop
7391 if Scope (Ent) = It.Typ then
7392 Set_Etype (Pref, It.Typ);
7393 exit;
7394 end if;
7396 Get_Next_Interp (I, It);
7397 end loop;
7398 end;
7399 end if;
7401 if Nkind (Entry_Name) = N_Selected_Component then
7402 Resolve (Prefix (Entry_Name));
7404 else pragma Assert (Nkind (Entry_Name) = N_Indexed_Component);
7405 Nam := Entity (Selector_Name (Prefix (Entry_Name)));
7406 Resolve (Prefix (Prefix (Entry_Name)));
7407 Index := First (Expressions (Entry_Name));
7408 Resolve (Index, Entry_Index_Type (Nam));
7410 -- Up to this point the expression could have been the actual in a
7411 -- simple entry call, and be given by a named association.
7413 if Nkind (Index) = N_Parameter_Association then
7414 Error_Msg_N ("expect expression for entry index", Index);
7415 else
7416 Apply_Range_Check (Index, Actual_Index_Type (Nam));
7417 end if;
7418 end if;
7419 end Resolve_Entry;
7421 ------------------------
7422 -- Resolve_Entry_Call --
7423 ------------------------
7425 procedure Resolve_Entry_Call (N : Node_Id; Typ : Entity_Id) is
7426 Entry_Name : constant Node_Id := Name (N);
7427 Loc : constant Source_Ptr := Sloc (Entry_Name);
7428 Actuals : List_Id;
7429 First_Named : Node_Id;
7430 Nam : Entity_Id;
7431 Norm_OK : Boolean;
7432 Obj : Node_Id;
7433 Was_Over : Boolean;
7435 begin
7436 -- We kill all checks here, because it does not seem worth the effort to
7437 -- do anything better, an entry call is a big operation.
7439 Kill_All_Checks;
7441 -- Processing of the name is similar for entry calls and protected
7442 -- operation calls. Once the entity is determined, we can complete
7443 -- the resolution of the actuals.
7445 -- The selector may be overloaded, in the case of a protected object
7446 -- with overloaded functions. The type of the context is used for
7447 -- resolution.
7449 if Nkind (Entry_Name) = N_Selected_Component
7450 and then Is_Overloaded (Selector_Name (Entry_Name))
7451 and then Typ /= Standard_Void_Type
7452 then
7453 declare
7454 I : Interp_Index;
7455 It : Interp;
7457 begin
7458 Get_First_Interp (Selector_Name (Entry_Name), I, It);
7459 while Present (It.Typ) loop
7460 if Covers (Typ, It.Typ) then
7461 Set_Entity (Selector_Name (Entry_Name), It.Nam);
7462 Set_Etype (Entry_Name, It.Typ);
7464 Generate_Reference (It.Typ, N, ' ');
7465 end if;
7467 Get_Next_Interp (I, It);
7468 end loop;
7469 end;
7470 end if;
7472 Resolve_Entry (Entry_Name);
7474 if Nkind (Entry_Name) = N_Selected_Component then
7476 -- Simple entry call
7478 Nam := Entity (Selector_Name (Entry_Name));
7479 Obj := Prefix (Entry_Name);
7480 Was_Over := Is_Overloaded (Selector_Name (Entry_Name));
7482 else pragma Assert (Nkind (Entry_Name) = N_Indexed_Component);
7484 -- Call to member of entry family
7486 Nam := Entity (Selector_Name (Prefix (Entry_Name)));
7487 Obj := Prefix (Prefix (Entry_Name));
7488 Was_Over := Is_Overloaded (Selector_Name (Prefix (Entry_Name)));
7489 end if;
7491 -- We cannot in general check the maximum depth of protected entry calls
7492 -- at compile time. But we can tell that any protected entry call at all
7493 -- violates a specified nesting depth of zero.
7495 if Is_Protected_Type (Scope (Nam)) then
7496 Check_Restriction (Max_Entry_Queue_Length, N);
7497 end if;
7499 -- Use context type to disambiguate a protected function that can be
7500 -- called without actuals and that returns an array type, and where the
7501 -- argument list may be an indexing of the returned value.
7503 if Ekind (Nam) = E_Function
7504 and then Needs_No_Actuals (Nam)
7505 and then Present (Parameter_Associations (N))
7506 and then
7507 ((Is_Array_Type (Etype (Nam))
7508 and then Covers (Typ, Component_Type (Etype (Nam))))
7510 or else (Is_Access_Type (Etype (Nam))
7511 and then Is_Array_Type (Designated_Type (Etype (Nam)))
7512 and then
7513 Covers
7514 (Typ,
7515 Component_Type (Designated_Type (Etype (Nam))))))
7516 then
7517 declare
7518 Index_Node : Node_Id;
7520 begin
7521 Index_Node :=
7522 Make_Indexed_Component (Loc,
7523 Prefix =>
7524 Make_Function_Call (Loc, Name => Relocate_Node (Entry_Name)),
7525 Expressions => Parameter_Associations (N));
7527 -- Since we are correcting a node classification error made by the
7528 -- parser, we call Replace rather than Rewrite.
7530 Replace (N, Index_Node);
7531 Set_Etype (Prefix (N), Etype (Nam));
7532 Set_Etype (N, Typ);
7533 Resolve_Indexed_Component (N, Typ);
7534 return;
7535 end;
7536 end if;
7538 if Ekind_In (Nam, E_Entry, E_Entry_Family)
7539 and then Present (PPC_Wrapper (Nam))
7540 and then Current_Scope /= PPC_Wrapper (Nam)
7541 then
7542 -- Rewrite as call to the precondition wrapper, adding the task
7543 -- object to the list of actuals. If the call is to a member of an
7544 -- entry family, include the index as well.
7546 declare
7547 New_Call : Node_Id;
7548 New_Actuals : List_Id;
7550 begin
7551 New_Actuals := New_List (Obj);
7553 if Nkind (Entry_Name) = N_Indexed_Component then
7554 Append_To (New_Actuals,
7555 New_Copy_Tree (First (Expressions (Entry_Name))));
7556 end if;
7558 Append_List (Parameter_Associations (N), New_Actuals);
7559 New_Call :=
7560 Make_Procedure_Call_Statement (Loc,
7561 Name =>
7562 New_Occurrence_Of (PPC_Wrapper (Nam), Loc),
7563 Parameter_Associations => New_Actuals);
7564 Rewrite (N, New_Call);
7566 -- Preanalyze and resolve new call. Current procedure is called
7567 -- from Resolve_Call, after which expansion will take place.
7569 Preanalyze_And_Resolve (N);
7570 return;
7571 end;
7572 end if;
7574 -- The operation name may have been overloaded. Order the actuals
7575 -- according to the formals of the resolved entity, and set the return
7576 -- type to that of the operation.
7578 if Was_Over then
7579 Normalize_Actuals (N, Nam, False, Norm_OK);
7580 pragma Assert (Norm_OK);
7581 Set_Etype (N, Etype (Nam));
7582 end if;
7584 Resolve_Actuals (N, Nam);
7585 Check_Internal_Protected_Use (N, Nam);
7587 -- Create a call reference to the entry
7589 Generate_Reference (Nam, Entry_Name, 's');
7591 if Ekind_In (Nam, E_Entry, E_Entry_Family) then
7592 Check_Potentially_Blocking_Operation (N);
7593 end if;
7595 -- Verify that a procedure call cannot masquerade as an entry
7596 -- call where an entry call is expected.
7598 if Ekind (Nam) = E_Procedure then
7599 if Nkind (Parent (N)) = N_Entry_Call_Alternative
7600 and then N = Entry_Call_Statement (Parent (N))
7601 then
7602 Error_Msg_N ("entry call required in select statement", N);
7604 elsif Nkind (Parent (N)) = N_Triggering_Alternative
7605 and then N = Triggering_Statement (Parent (N))
7606 then
7607 Error_Msg_N ("triggering statement cannot be procedure call", N);
7609 elsif Ekind (Scope (Nam)) = E_Task_Type
7610 and then not In_Open_Scopes (Scope (Nam))
7611 then
7612 Error_Msg_N ("task has no entry with this name", Entry_Name);
7613 end if;
7614 end if;
7616 -- After resolution, entry calls and protected procedure calls are
7617 -- changed into entry calls, for expansion. The structure of the node
7618 -- does not change, so it can safely be done in place. Protected
7619 -- function calls must keep their structure because they are
7620 -- subexpressions.
7622 if Ekind (Nam) /= E_Function then
7624 -- A protected operation that is not a function may modify the
7625 -- corresponding object, and cannot apply to a constant. If this
7626 -- is an internal call, the prefix is the type itself.
7628 if Is_Protected_Type (Scope (Nam))
7629 and then not Is_Variable (Obj)
7630 and then (not Is_Entity_Name (Obj)
7631 or else not Is_Type (Entity (Obj)))
7632 then
7633 Error_Msg_N
7634 ("prefix of protected procedure or entry call must be variable",
7635 Entry_Name);
7636 end if;
7638 Actuals := Parameter_Associations (N);
7639 First_Named := First_Named_Actual (N);
7641 Rewrite (N,
7642 Make_Entry_Call_Statement (Loc,
7643 Name => Entry_Name,
7644 Parameter_Associations => Actuals));
7646 Set_First_Named_Actual (N, First_Named);
7647 Set_Analyzed (N, True);
7649 -- Protected functions can return on the secondary stack, in which
7650 -- case we must trigger the transient scope mechanism.
7652 elsif Expander_Active
7653 and then Requires_Transient_Scope (Etype (Nam))
7654 then
7655 Establish_Transient_Scope (N, Sec_Stack => True);
7656 end if;
7657 end Resolve_Entry_Call;
7659 -------------------------
7660 -- Resolve_Equality_Op --
7661 -------------------------
7663 -- Both arguments must have the same type, and the boolean context does
7664 -- not participate in the resolution. The first pass verifies that the
7665 -- interpretation is not ambiguous, and the type of the left argument is
7666 -- correctly set, or is Any_Type in case of ambiguity. If both arguments
7667 -- are strings or aggregates, allocators, or Null, they are ambiguous even
7668 -- though they carry a single (universal) type. Diagnose this case here.
7670 procedure Resolve_Equality_Op (N : Node_Id; Typ : Entity_Id) is
7671 L : constant Node_Id := Left_Opnd (N);
7672 R : constant Node_Id := Right_Opnd (N);
7673 T : Entity_Id := Find_Unique_Type (L, R);
7675 procedure Check_If_Expression (Cond : Node_Id);
7676 -- The resolution rule for if expressions requires that each such must
7677 -- have a unique type. This means that if several dependent expressions
7678 -- are of a non-null anonymous access type, and the context does not
7679 -- impose an expected type (as can be the case in an equality operation)
7680 -- the expression must be rejected.
7682 procedure Explain_Redundancy (N : Node_Id);
7683 -- Attempt to explain the nature of a redundant comparison with True. If
7684 -- the expression N is too complex, this routine issues a general error
7685 -- message.
7687 function Find_Unique_Access_Type return Entity_Id;
7688 -- In the case of allocators and access attributes, the context must
7689 -- provide an indication of the specific access type to be used. If
7690 -- one operand is of such a "generic" access type, check whether there
7691 -- is a specific visible access type that has the same designated type.
7692 -- This is semantically dubious, and of no interest to any real code,
7693 -- but c48008a makes it all worthwhile.
7695 -------------------------
7696 -- Check_If_Expression --
7697 -------------------------
7699 procedure Check_If_Expression (Cond : Node_Id) is
7700 Then_Expr : Node_Id;
7701 Else_Expr : Node_Id;
7703 begin
7704 if Nkind (Cond) = N_If_Expression then
7705 Then_Expr := Next (First (Expressions (Cond)));
7706 Else_Expr := Next (Then_Expr);
7708 if Nkind (Then_Expr) /= N_Null
7709 and then Nkind (Else_Expr) /= N_Null
7710 then
7711 Error_Msg_N ("cannot determine type of if expression", Cond);
7712 end if;
7713 end if;
7714 end Check_If_Expression;
7716 ------------------------
7717 -- Explain_Redundancy --
7718 ------------------------
7720 procedure Explain_Redundancy (N : Node_Id) is
7721 Error : Name_Id;
7722 Val : Node_Id;
7723 Val_Id : Entity_Id;
7725 begin
7726 Val := N;
7728 -- Strip the operand down to an entity
7730 loop
7731 if Nkind (Val) = N_Selected_Component then
7732 Val := Selector_Name (Val);
7733 else
7734 exit;
7735 end if;
7736 end loop;
7738 -- The construct denotes an entity
7740 if Is_Entity_Name (Val) and then Present (Entity (Val)) then
7741 Val_Id := Entity (Val);
7743 -- Do not generate an error message when the comparison is done
7744 -- against the enumeration literal Standard.True.
7746 if Ekind (Val_Id) /= E_Enumeration_Literal then
7748 -- Build a customized error message
7750 Name_Len := 0;
7751 Add_Str_To_Name_Buffer ("?r?");
7753 if Ekind (Val_Id) = E_Component then
7754 Add_Str_To_Name_Buffer ("component ");
7756 elsif Ekind (Val_Id) = E_Constant then
7757 Add_Str_To_Name_Buffer ("constant ");
7759 elsif Ekind (Val_Id) = E_Discriminant then
7760 Add_Str_To_Name_Buffer ("discriminant ");
7762 elsif Is_Formal (Val_Id) then
7763 Add_Str_To_Name_Buffer ("parameter ");
7765 elsif Ekind (Val_Id) = E_Variable then
7766 Add_Str_To_Name_Buffer ("variable ");
7767 end if;
7769 Add_Str_To_Name_Buffer ("& is always True!");
7770 Error := Name_Find;
7772 Error_Msg_NE (Get_Name_String (Error), Val, Val_Id);
7773 end if;
7775 -- The construct is too complex to disect, issue a general message
7777 else
7778 Error_Msg_N ("?r?expression is always True!", Val);
7779 end if;
7780 end Explain_Redundancy;
7782 -----------------------------
7783 -- Find_Unique_Access_Type --
7784 -----------------------------
7786 function Find_Unique_Access_Type return Entity_Id is
7787 Acc : Entity_Id;
7788 E : Entity_Id;
7789 S : Entity_Id;
7791 begin
7792 if Ekind_In (Etype (R), E_Allocator_Type,
7793 E_Access_Attribute_Type)
7794 then
7795 Acc := Designated_Type (Etype (R));
7797 elsif Ekind_In (Etype (L), E_Allocator_Type,
7798 E_Access_Attribute_Type)
7799 then
7800 Acc := Designated_Type (Etype (L));
7801 else
7802 return Empty;
7803 end if;
7805 S := Current_Scope;
7806 while S /= Standard_Standard loop
7807 E := First_Entity (S);
7808 while Present (E) loop
7809 if Is_Type (E)
7810 and then Is_Access_Type (E)
7811 and then Ekind (E) /= E_Allocator_Type
7812 and then Designated_Type (E) = Base_Type (Acc)
7813 then
7814 return E;
7815 end if;
7817 Next_Entity (E);
7818 end loop;
7820 S := Scope (S);
7821 end loop;
7823 return Empty;
7824 end Find_Unique_Access_Type;
7826 -- Start of processing for Resolve_Equality_Op
7828 begin
7829 Set_Etype (N, Base_Type (Typ));
7830 Generate_Reference (T, N, ' ');
7832 if T = Any_Fixed then
7833 T := Unique_Fixed_Point_Type (L);
7834 end if;
7836 if T /= Any_Type then
7837 if T = Any_String or else
7838 T = Any_Composite or else
7839 T = Any_Character
7840 then
7841 if T = Any_Character then
7842 Ambiguous_Character (L);
7843 else
7844 Error_Msg_N ("ambiguous operands for equality", N);
7845 end if;
7847 Set_Etype (N, Any_Type);
7848 return;
7850 elsif T = Any_Access
7851 or else Ekind_In (T, E_Allocator_Type, E_Access_Attribute_Type)
7852 then
7853 T := Find_Unique_Access_Type;
7855 if No (T) then
7856 Error_Msg_N ("ambiguous operands for equality", N);
7857 Set_Etype (N, Any_Type);
7858 return;
7859 end if;
7861 -- If expressions must have a single type, and if the context does
7862 -- not impose one the dependent expressions cannot be anonymous
7863 -- access types.
7865 -- Why no similar processing for case expressions???
7867 elsif Ada_Version >= Ada_2012
7868 and then Ekind_In (Etype (L), E_Anonymous_Access_Type,
7869 E_Anonymous_Access_Subprogram_Type)
7870 and then Ekind_In (Etype (R), E_Anonymous_Access_Type,
7871 E_Anonymous_Access_Subprogram_Type)
7872 then
7873 Check_If_Expression (L);
7874 Check_If_Expression (R);
7875 end if;
7877 Resolve (L, T);
7878 Resolve (R, T);
7880 -- In SPARK, equality operators = and /= for array types other than
7881 -- String are only defined when, for each index position, the
7882 -- operands have equal static bounds.
7884 if Is_Array_Type (T) then
7886 -- Protect call to Matching_Static_Array_Bounds to avoid costly
7887 -- operation if not needed.
7889 if Restriction_Check_Required (SPARK_05)
7890 and then Base_Type (T) /= Standard_String
7891 and then Base_Type (Etype (L)) = Base_Type (Etype (R))
7892 and then Etype (L) /= Any_Composite -- or else L in error
7893 and then Etype (R) /= Any_Composite -- or else R in error
7894 and then not Matching_Static_Array_Bounds (Etype (L), Etype (R))
7895 then
7896 Check_SPARK_05_Restriction
7897 ("array types should have matching static bounds", N);
7898 end if;
7899 end if;
7901 -- If the unique type is a class-wide type then it will be expanded
7902 -- into a dispatching call to the predefined primitive. Therefore we
7903 -- check here for potential violation of such restriction.
7905 if Is_Class_Wide_Type (T) then
7906 Check_Restriction (No_Dispatching_Calls, N);
7907 end if;
7909 if Warn_On_Redundant_Constructs
7910 and then Comes_From_Source (N)
7911 and then Comes_From_Source (R)
7912 and then Is_Entity_Name (R)
7913 and then Entity (R) = Standard_True
7914 then
7915 Error_Msg_N -- CODEFIX
7916 ("?r?comparison with True is redundant!", N);
7917 Explain_Redundancy (Original_Node (R));
7918 end if;
7920 Check_Unset_Reference (L);
7921 Check_Unset_Reference (R);
7922 Generate_Operator_Reference (N, T);
7923 Check_Low_Bound_Tested (N);
7925 -- If this is an inequality, it may be the implicit inequality
7926 -- created for a user-defined operation, in which case the corres-
7927 -- ponding equality operation is not intrinsic, and the operation
7928 -- cannot be constant-folded. Else fold.
7930 if Nkind (N) = N_Op_Eq
7931 or else Comes_From_Source (Entity (N))
7932 or else Ekind (Entity (N)) = E_Operator
7933 or else Is_Intrinsic_Subprogram
7934 (Corresponding_Equality (Entity (N)))
7935 then
7936 Analyze_Dimension (N);
7937 Eval_Relational_Op (N);
7939 elsif Nkind (N) = N_Op_Ne
7940 and then Is_Abstract_Subprogram (Entity (N))
7941 then
7942 Error_Msg_NE ("cannot call abstract subprogram &!", N, Entity (N));
7943 end if;
7945 -- Ada 2005: If one operand is an anonymous access type, convert the
7946 -- other operand to it, to ensure that the underlying types match in
7947 -- the back-end. Same for access_to_subprogram, and the conversion
7948 -- verifies that the types are subtype conformant.
7950 -- We apply the same conversion in the case one of the operands is a
7951 -- private subtype of the type of the other.
7953 -- Why the Expander_Active test here ???
7955 if Expander_Active
7956 and then
7957 (Ekind_In (T, E_Anonymous_Access_Type,
7958 E_Anonymous_Access_Subprogram_Type)
7959 or else Is_Private_Type (T))
7960 then
7961 if Etype (L) /= T then
7962 Rewrite (L,
7963 Make_Unchecked_Type_Conversion (Sloc (L),
7964 Subtype_Mark => New_Occurrence_Of (T, Sloc (L)),
7965 Expression => Relocate_Node (L)));
7966 Analyze_And_Resolve (L, T);
7967 end if;
7969 if (Etype (R)) /= T then
7970 Rewrite (R,
7971 Make_Unchecked_Type_Conversion (Sloc (R),
7972 Subtype_Mark => New_Occurrence_Of (Etype (L), Sloc (R)),
7973 Expression => Relocate_Node (R)));
7974 Analyze_And_Resolve (R, T);
7975 end if;
7976 end if;
7977 end if;
7978 end Resolve_Equality_Op;
7980 ----------------------------------
7981 -- Resolve_Explicit_Dereference --
7982 ----------------------------------
7984 procedure Resolve_Explicit_Dereference (N : Node_Id; Typ : Entity_Id) is
7985 Loc : constant Source_Ptr := Sloc (N);
7986 New_N : Node_Id;
7987 P : constant Node_Id := Prefix (N);
7989 P_Typ : Entity_Id;
7990 -- The candidate prefix type, if overloaded
7992 I : Interp_Index;
7993 It : Interp;
7995 begin
7996 Check_Fully_Declared_Prefix (Typ, P);
7997 P_Typ := Empty;
7999 -- A useful optimization: check whether the dereference denotes an
8000 -- element of a container, and if so rewrite it as a call to the
8001 -- corresponding Element function.
8003 -- Disabled for now, on advice of ARG. A more restricted form of the
8004 -- predicate might be acceptable ???
8006 -- if Is_Container_Element (N) then
8007 -- return;
8008 -- end if;
8010 if Is_Overloaded (P) then
8012 -- Use the context type to select the prefix that has the correct
8013 -- designated type. Keep the first match, which will be the inner-
8014 -- most.
8016 Get_First_Interp (P, I, It);
8018 while Present (It.Typ) loop
8019 if Is_Access_Type (It.Typ)
8020 and then Covers (Typ, Designated_Type (It.Typ))
8021 then
8022 if No (P_Typ) then
8023 P_Typ := It.Typ;
8024 end if;
8026 -- Remove access types that do not match, but preserve access
8027 -- to subprogram interpretations, in case a further dereference
8028 -- is needed (see below).
8030 elsif Ekind (It.Typ) /= E_Access_Subprogram_Type then
8031 Remove_Interp (I);
8032 end if;
8034 Get_Next_Interp (I, It);
8035 end loop;
8037 if Present (P_Typ) then
8038 Resolve (P, P_Typ);
8039 Set_Etype (N, Designated_Type (P_Typ));
8041 else
8042 -- If no interpretation covers the designated type of the prefix,
8043 -- this is the pathological case where not all implementations of
8044 -- the prefix allow the interpretation of the node as a call. Now
8045 -- that the expected type is known, Remove other interpretations
8046 -- from prefix, rewrite it as a call, and resolve again, so that
8047 -- the proper call node is generated.
8049 Get_First_Interp (P, I, It);
8050 while Present (It.Typ) loop
8051 if Ekind (It.Typ) /= E_Access_Subprogram_Type then
8052 Remove_Interp (I);
8053 end if;
8055 Get_Next_Interp (I, It);
8056 end loop;
8058 New_N :=
8059 Make_Function_Call (Loc,
8060 Name =>
8061 Make_Explicit_Dereference (Loc,
8062 Prefix => P),
8063 Parameter_Associations => New_List);
8065 Save_Interps (N, New_N);
8066 Rewrite (N, New_N);
8067 Analyze_And_Resolve (N, Typ);
8068 return;
8069 end if;
8071 -- If not overloaded, resolve P with its own type
8073 else
8074 Resolve (P);
8075 end if;
8077 if Is_Access_Type (Etype (P)) then
8078 Apply_Access_Check (N);
8079 end if;
8081 -- If the designated type is a packed unconstrained array type, and the
8082 -- explicit dereference is not in the context of an attribute reference,
8083 -- then we must compute and set the actual subtype, since it is needed
8084 -- by Gigi. The reason we exclude the attribute case is that this is
8085 -- handled fine by Gigi, and in fact we use such attributes to build the
8086 -- actual subtype. We also exclude generated code (which builds actual
8087 -- subtypes directly if they are needed).
8089 if Is_Array_Type (Etype (N))
8090 and then Is_Packed (Etype (N))
8091 and then not Is_Constrained (Etype (N))
8092 and then Nkind (Parent (N)) /= N_Attribute_Reference
8093 and then Comes_From_Source (N)
8094 then
8095 Set_Etype (N, Get_Actual_Subtype (N));
8096 end if;
8098 -- Note: No Eval processing is required for an explicit dereference,
8099 -- because such a name can never be static.
8101 end Resolve_Explicit_Dereference;
8103 -------------------------------------
8104 -- Resolve_Expression_With_Actions --
8105 -------------------------------------
8107 procedure Resolve_Expression_With_Actions (N : Node_Id; Typ : Entity_Id) is
8108 begin
8109 Set_Etype (N, Typ);
8111 -- If N has no actions, and its expression has been constant folded,
8112 -- then rewrite N as just its expression. Note, we can't do this in
8113 -- the general case of Is_Empty_List (Actions (N)) as this would cause
8114 -- Expression (N) to be expanded again.
8116 if Is_Empty_List (Actions (N))
8117 and then Compile_Time_Known_Value (Expression (N))
8118 then
8119 Rewrite (N, Expression (N));
8120 end if;
8121 end Resolve_Expression_With_Actions;
8123 ----------------------------------
8124 -- Resolve_Generalized_Indexing --
8125 ----------------------------------
8127 procedure Resolve_Generalized_Indexing (N : Node_Id; Typ : Entity_Id) is
8128 Indexing : constant Node_Id := Generalized_Indexing (N);
8129 Call : Node_Id;
8130 Indices : List_Id;
8131 Pref : Node_Id;
8133 begin
8134 -- In ASIS mode, propagate the information about the indices back to
8135 -- to the original indexing node. The generalized indexing is either
8136 -- a function call, or a dereference of one. The actuals include the
8137 -- prefix of the original node, which is the container expression.
8139 if ASIS_Mode then
8140 Resolve (Indexing, Typ);
8141 Set_Etype (N, Etype (Indexing));
8142 Set_Is_Overloaded (N, False);
8144 Call := Indexing;
8145 while Nkind_In (Call, N_Explicit_Dereference, N_Selected_Component)
8146 loop
8147 Call := Prefix (Call);
8148 end loop;
8150 if Nkind (Call) = N_Function_Call then
8151 Indices := Parameter_Associations (Call);
8152 Pref := Remove_Head (Indices);
8153 Set_Expressions (N, Indices);
8154 Set_Prefix (N, Pref);
8155 end if;
8157 else
8158 Rewrite (N, Indexing);
8159 Resolve (N, Typ);
8160 end if;
8161 end Resolve_Generalized_Indexing;
8163 ---------------------------
8164 -- Resolve_If_Expression --
8165 ---------------------------
8167 procedure Resolve_If_Expression (N : Node_Id; Typ : Entity_Id) is
8168 Condition : constant Node_Id := First (Expressions (N));
8169 Then_Expr : constant Node_Id := Next (Condition);
8170 Else_Expr : Node_Id := Next (Then_Expr);
8171 Else_Typ : Entity_Id;
8172 Then_Typ : Entity_Id;
8174 begin
8175 Resolve (Condition, Any_Boolean);
8176 Resolve (Then_Expr, Typ);
8177 Then_Typ := Etype (Then_Expr);
8179 -- When the "then" expression is of a scalar subtype different from the
8180 -- result subtype, then insert a conversion to ensure the generation of
8181 -- a constraint check. The same is done for the else part below, again
8182 -- comparing subtypes rather than base types.
8184 if Is_Scalar_Type (Then_Typ)
8185 and then Then_Typ /= Typ
8186 then
8187 Rewrite (Then_Expr, Convert_To (Typ, Then_Expr));
8188 Analyze_And_Resolve (Then_Expr, Typ);
8189 end if;
8191 -- If ELSE expression present, just resolve using the determined type
8193 if Present (Else_Expr) then
8194 Resolve (Else_Expr, Typ);
8195 Else_Typ := Etype (Else_Expr);
8197 if Is_Scalar_Type (Else_Typ)
8198 and then Else_Typ /= Typ
8199 then
8200 Rewrite (Else_Expr, Convert_To (Typ, Else_Expr));
8201 Analyze_And_Resolve (Else_Expr, Typ);
8202 end if;
8204 -- If no ELSE expression is present, root type must be Standard.Boolean
8205 -- and we provide a Standard.True result converted to the appropriate
8206 -- Boolean type (in case it is a derived boolean type).
8208 elsif Root_Type (Typ) = Standard_Boolean then
8209 Else_Expr :=
8210 Convert_To (Typ, New_Occurrence_Of (Standard_True, Sloc (N)));
8211 Analyze_And_Resolve (Else_Expr, Typ);
8212 Append_To (Expressions (N), Else_Expr);
8214 else
8215 Error_Msg_N ("can only omit ELSE expression in Boolean case", N);
8216 Append_To (Expressions (N), Error);
8217 end if;
8219 Set_Etype (N, Typ);
8220 Eval_If_Expression (N);
8221 end Resolve_If_Expression;
8223 -------------------------------
8224 -- Resolve_Indexed_Component --
8225 -------------------------------
8227 procedure Resolve_Indexed_Component (N : Node_Id; Typ : Entity_Id) is
8228 Name : constant Node_Id := Prefix (N);
8229 Expr : Node_Id;
8230 Array_Type : Entity_Id := Empty; -- to prevent junk warning
8231 Index : Node_Id;
8233 begin
8234 if Present (Generalized_Indexing (N)) then
8235 Resolve_Generalized_Indexing (N, Typ);
8236 return;
8237 end if;
8239 if Is_Overloaded (Name) then
8241 -- Use the context type to select the prefix that yields the correct
8242 -- component type.
8244 declare
8245 I : Interp_Index;
8246 It : Interp;
8247 I1 : Interp_Index := 0;
8248 P : constant Node_Id := Prefix (N);
8249 Found : Boolean := False;
8251 begin
8252 Get_First_Interp (P, I, It);
8253 while Present (It.Typ) loop
8254 if (Is_Array_Type (It.Typ)
8255 and then Covers (Typ, Component_Type (It.Typ)))
8256 or else (Is_Access_Type (It.Typ)
8257 and then Is_Array_Type (Designated_Type (It.Typ))
8258 and then
8259 Covers
8260 (Typ,
8261 Component_Type (Designated_Type (It.Typ))))
8262 then
8263 if Found then
8264 It := Disambiguate (P, I1, I, Any_Type);
8266 if It = No_Interp then
8267 Error_Msg_N ("ambiguous prefix for indexing", N);
8268 Set_Etype (N, Typ);
8269 return;
8271 else
8272 Found := True;
8273 Array_Type := It.Typ;
8274 I1 := I;
8275 end if;
8277 else
8278 Found := True;
8279 Array_Type := It.Typ;
8280 I1 := I;
8281 end if;
8282 end if;
8284 Get_Next_Interp (I, It);
8285 end loop;
8286 end;
8288 else
8289 Array_Type := Etype (Name);
8290 end if;
8292 Resolve (Name, Array_Type);
8293 Array_Type := Get_Actual_Subtype_If_Available (Name);
8295 -- If prefix is access type, dereference to get real array type.
8296 -- Note: we do not apply an access check because the expander always
8297 -- introduces an explicit dereference, and the check will happen there.
8299 if Is_Access_Type (Array_Type) then
8300 Array_Type := Designated_Type (Array_Type);
8301 end if;
8303 -- If name was overloaded, set component type correctly now
8304 -- If a misplaced call to an entry family (which has no index types)
8305 -- return. Error will be diagnosed from calling context.
8307 if Is_Array_Type (Array_Type) then
8308 Set_Etype (N, Component_Type (Array_Type));
8309 else
8310 return;
8311 end if;
8313 Index := First_Index (Array_Type);
8314 Expr := First (Expressions (N));
8316 -- The prefix may have resolved to a string literal, in which case its
8317 -- etype has a special representation. This is only possible currently
8318 -- if the prefix is a static concatenation, written in functional
8319 -- notation.
8321 if Ekind (Array_Type) = E_String_Literal_Subtype then
8322 Resolve (Expr, Standard_Positive);
8324 else
8325 while Present (Index) and Present (Expr) loop
8326 Resolve (Expr, Etype (Index));
8327 Check_Unset_Reference (Expr);
8329 if Is_Scalar_Type (Etype (Expr)) then
8330 Apply_Scalar_Range_Check (Expr, Etype (Index));
8331 else
8332 Apply_Range_Check (Expr, Get_Actual_Subtype (Index));
8333 end if;
8335 Next_Index (Index);
8336 Next (Expr);
8337 end loop;
8338 end if;
8340 Analyze_Dimension (N);
8342 -- Do not generate the warning on suspicious index if we are analyzing
8343 -- package Ada.Tags; otherwise we will report the warning with the
8344 -- Prims_Ptr field of the dispatch table.
8346 if Scope (Etype (Prefix (N))) = Standard_Standard
8347 or else not
8348 Is_RTU (Cunit_Entity (Get_Source_Unit (Etype (Prefix (N)))),
8349 Ada_Tags)
8350 then
8351 Warn_On_Suspicious_Index (Name, First (Expressions (N)));
8352 Eval_Indexed_Component (N);
8353 end if;
8355 -- If the array type is atomic, and the component is not atomic, then
8356 -- this is worth a warning, since we have a situation where the access
8357 -- to the component may cause extra read/writes of the atomic array
8358 -- object, or partial word accesses, which could be unexpected.
8360 if Nkind (N) = N_Indexed_Component
8361 and then Is_Atomic_Ref_With_Address (N)
8362 and then not (Has_Atomic_Components (Array_Type)
8363 or else (Is_Entity_Name (Prefix (N))
8364 and then Has_Atomic_Components
8365 (Entity (Prefix (N)))))
8366 and then not Is_Atomic (Component_Type (Array_Type))
8367 then
8368 Error_Msg_N ("??access to non-atomic component of atomic array",
8369 Prefix (N));
8370 Error_Msg_N ("??\may cause unexpected accesses to atomic object",
8371 Prefix (N));
8372 end if;
8373 end Resolve_Indexed_Component;
8375 -----------------------------
8376 -- Resolve_Integer_Literal --
8377 -----------------------------
8379 procedure Resolve_Integer_Literal (N : Node_Id; Typ : Entity_Id) is
8380 begin
8381 Set_Etype (N, Typ);
8382 Eval_Integer_Literal (N);
8383 end Resolve_Integer_Literal;
8385 --------------------------------
8386 -- Resolve_Intrinsic_Operator --
8387 --------------------------------
8389 procedure Resolve_Intrinsic_Operator (N : Node_Id; Typ : Entity_Id) is
8390 Btyp : constant Entity_Id := Base_Type (Underlying_Type (Typ));
8391 Op : Entity_Id;
8392 Arg1 : Node_Id;
8393 Arg2 : Node_Id;
8395 function Convert_Operand (Opnd : Node_Id) return Node_Id;
8396 -- If the operand is a literal, it cannot be the expression in a
8397 -- conversion. Use a qualified expression instead.
8399 function Convert_Operand (Opnd : Node_Id) return Node_Id is
8400 Loc : constant Source_Ptr := Sloc (Opnd);
8401 Res : Node_Id;
8402 begin
8403 if Nkind_In (Opnd, N_Integer_Literal, N_Real_Literal) then
8404 Res :=
8405 Make_Qualified_Expression (Loc,
8406 Subtype_Mark => New_Occurrence_Of (Btyp, Loc),
8407 Expression => Relocate_Node (Opnd));
8408 Analyze (Res);
8410 else
8411 Res := Unchecked_Convert_To (Btyp, Opnd);
8412 end if;
8414 return Res;
8415 end Convert_Operand;
8417 -- Start of processing for Resolve_Intrinsic_Operator
8419 begin
8420 -- We must preserve the original entity in a generic setting, so that
8421 -- the legality of the operation can be verified in an instance.
8423 if not Expander_Active then
8424 return;
8425 end if;
8427 Op := Entity (N);
8428 while Scope (Op) /= Standard_Standard loop
8429 Op := Homonym (Op);
8430 pragma Assert (Present (Op));
8431 end loop;
8433 Set_Entity (N, Op);
8434 Set_Is_Overloaded (N, False);
8436 -- If the result or operand types are private, rewrite with unchecked
8437 -- conversions on the operands and the result, to expose the proper
8438 -- underlying numeric type.
8440 if Is_Private_Type (Typ)
8441 or else Is_Private_Type (Etype (Left_Opnd (N)))
8442 or else Is_Private_Type (Etype (Right_Opnd (N)))
8443 then
8444 Arg1 := Convert_Operand (Left_Opnd (N));
8445 -- Unchecked_Convert_To (Btyp, Left_Opnd (N));
8446 -- What on earth is this commented out fragment of code???
8448 if Nkind (N) = N_Op_Expon then
8449 Arg2 := Unchecked_Convert_To (Standard_Integer, Right_Opnd (N));
8450 else
8451 Arg2 := Convert_Operand (Right_Opnd (N));
8452 end if;
8454 if Nkind (Arg1) = N_Type_Conversion then
8455 Save_Interps (Left_Opnd (N), Expression (Arg1));
8456 end if;
8458 if Nkind (Arg2) = N_Type_Conversion then
8459 Save_Interps (Right_Opnd (N), Expression (Arg2));
8460 end if;
8462 Set_Left_Opnd (N, Arg1);
8463 Set_Right_Opnd (N, Arg2);
8465 Set_Etype (N, Btyp);
8466 Rewrite (N, Unchecked_Convert_To (Typ, N));
8467 Resolve (N, Typ);
8469 elsif Typ /= Etype (Left_Opnd (N))
8470 or else Typ /= Etype (Right_Opnd (N))
8471 then
8472 -- Add explicit conversion where needed, and save interpretations in
8473 -- case operands are overloaded.
8475 Arg1 := Convert_To (Typ, Left_Opnd (N));
8476 Arg2 := Convert_To (Typ, Right_Opnd (N));
8478 if Nkind (Arg1) = N_Type_Conversion then
8479 Save_Interps (Left_Opnd (N), Expression (Arg1));
8480 else
8481 Save_Interps (Left_Opnd (N), Arg1);
8482 end if;
8484 if Nkind (Arg2) = N_Type_Conversion then
8485 Save_Interps (Right_Opnd (N), Expression (Arg2));
8486 else
8487 Save_Interps (Right_Opnd (N), Arg2);
8488 end if;
8490 Rewrite (Left_Opnd (N), Arg1);
8491 Rewrite (Right_Opnd (N), Arg2);
8492 Analyze (Arg1);
8493 Analyze (Arg2);
8494 Resolve_Arithmetic_Op (N, Typ);
8496 else
8497 Resolve_Arithmetic_Op (N, Typ);
8498 end if;
8499 end Resolve_Intrinsic_Operator;
8501 --------------------------------------
8502 -- Resolve_Intrinsic_Unary_Operator --
8503 --------------------------------------
8505 procedure Resolve_Intrinsic_Unary_Operator
8506 (N : Node_Id;
8507 Typ : Entity_Id)
8509 Btyp : constant Entity_Id := Base_Type (Underlying_Type (Typ));
8510 Op : Entity_Id;
8511 Arg2 : Node_Id;
8513 begin
8514 Op := Entity (N);
8515 while Scope (Op) /= Standard_Standard loop
8516 Op := Homonym (Op);
8517 pragma Assert (Present (Op));
8518 end loop;
8520 Set_Entity (N, Op);
8522 if Is_Private_Type (Typ) then
8523 Arg2 := Unchecked_Convert_To (Btyp, Right_Opnd (N));
8524 Save_Interps (Right_Opnd (N), Expression (Arg2));
8526 Set_Right_Opnd (N, Arg2);
8528 Set_Etype (N, Btyp);
8529 Rewrite (N, Unchecked_Convert_To (Typ, N));
8530 Resolve (N, Typ);
8532 else
8533 Resolve_Unary_Op (N, Typ);
8534 end if;
8535 end Resolve_Intrinsic_Unary_Operator;
8537 ------------------------
8538 -- Resolve_Logical_Op --
8539 ------------------------
8541 procedure Resolve_Logical_Op (N : Node_Id; Typ : Entity_Id) is
8542 B_Typ : Entity_Id;
8544 begin
8545 Check_No_Direct_Boolean_Operators (N);
8547 -- Predefined operations on scalar types yield the base type. On the
8548 -- other hand, logical operations on arrays yield the type of the
8549 -- arguments (and the context).
8551 if Is_Array_Type (Typ) then
8552 B_Typ := Typ;
8553 else
8554 B_Typ := Base_Type (Typ);
8555 end if;
8557 -- The following test is required because the operands of the operation
8558 -- may be literals, in which case the resulting type appears to be
8559 -- compatible with a signed integer type, when in fact it is compatible
8560 -- only with modular types. If the context itself is universal, the
8561 -- operation is illegal.
8563 if not Valid_Boolean_Arg (Typ) then
8564 Error_Msg_N ("invalid context for logical operation", N);
8565 Set_Etype (N, Any_Type);
8566 return;
8568 elsif Typ = Any_Modular then
8569 Error_Msg_N
8570 ("no modular type available in this context", N);
8571 Set_Etype (N, Any_Type);
8572 return;
8574 elsif Is_Modular_Integer_Type (Typ)
8575 and then Etype (Left_Opnd (N)) = Universal_Integer
8576 and then Etype (Right_Opnd (N)) = Universal_Integer
8577 then
8578 Check_For_Visible_Operator (N, B_Typ);
8579 end if;
8581 -- Replace AND by AND THEN, or OR by OR ELSE, if Short_Circuit_And_Or
8582 -- is active and the result type is standard Boolean (do not mess with
8583 -- ops that return a nonstandard Boolean type, because something strange
8584 -- is going on).
8586 -- Note: you might expect this replacement to be done during expansion,
8587 -- but that doesn't work, because when the pragma Short_Circuit_And_Or
8588 -- is used, no part of the right operand of an "and" or "or" operator
8589 -- should be executed if the left operand would short-circuit the
8590 -- evaluation of the corresponding "and then" or "or else". If we left
8591 -- the replacement to expansion time, then run-time checks associated
8592 -- with such operands would be evaluated unconditionally, due to being
8593 -- before the condition prior to the rewriting as short-circuit forms
8594 -- during expansion.
8596 if Short_Circuit_And_Or
8597 and then B_Typ = Standard_Boolean
8598 and then Nkind_In (N, N_Op_And, N_Op_Or)
8599 then
8600 if Nkind (N) = N_Op_And then
8601 Rewrite (N,
8602 Make_And_Then (Sloc (N),
8603 Left_Opnd => Relocate_Node (Left_Opnd (N)),
8604 Right_Opnd => Relocate_Node (Right_Opnd (N))));
8605 Analyze_And_Resolve (N, B_Typ);
8607 -- Case of OR changed to OR ELSE
8609 else
8610 Rewrite (N,
8611 Make_Or_Else (Sloc (N),
8612 Left_Opnd => Relocate_Node (Left_Opnd (N)),
8613 Right_Opnd => Relocate_Node (Right_Opnd (N))));
8614 Analyze_And_Resolve (N, B_Typ);
8615 end if;
8617 -- Return now, since analysis of the rewritten ops will take care of
8618 -- other reference bookkeeping and expression folding.
8620 return;
8621 end if;
8623 Resolve (Left_Opnd (N), B_Typ);
8624 Resolve (Right_Opnd (N), B_Typ);
8626 Check_Unset_Reference (Left_Opnd (N));
8627 Check_Unset_Reference (Right_Opnd (N));
8629 Set_Etype (N, B_Typ);
8630 Generate_Operator_Reference (N, B_Typ);
8631 Eval_Logical_Op (N);
8633 -- In SPARK, logical operations AND, OR and XOR for arrays are defined
8634 -- only when both operands have same static lower and higher bounds. Of
8635 -- course the types have to match, so only check if operands are
8636 -- compatible and the node itself has no errors.
8638 if Is_Array_Type (B_Typ)
8639 and then Nkind (N) in N_Binary_Op
8640 then
8641 declare
8642 Left_Typ : constant Node_Id := Etype (Left_Opnd (N));
8643 Right_Typ : constant Node_Id := Etype (Right_Opnd (N));
8645 begin
8646 -- Protect call to Matching_Static_Array_Bounds to avoid costly
8647 -- operation if not needed.
8649 if Restriction_Check_Required (SPARK_05)
8650 and then Base_Type (Left_Typ) = Base_Type (Right_Typ)
8651 and then Left_Typ /= Any_Composite -- or Left_Opnd in error
8652 and then Right_Typ /= Any_Composite -- or Right_Opnd in error
8653 and then not Matching_Static_Array_Bounds (Left_Typ, Right_Typ)
8654 then
8655 Check_SPARK_05_Restriction
8656 ("array types should have matching static bounds", N);
8657 end if;
8658 end;
8659 end if;
8661 Check_Function_Writable_Actuals (N);
8662 end Resolve_Logical_Op;
8664 ---------------------------
8665 -- Resolve_Membership_Op --
8666 ---------------------------
8668 -- The context can only be a boolean type, and does not determine the
8669 -- arguments. Arguments should be unambiguous, but the preference rule for
8670 -- universal types applies.
8672 procedure Resolve_Membership_Op (N : Node_Id; Typ : Entity_Id) is
8673 pragma Warnings (Off, Typ);
8675 L : constant Node_Id := Left_Opnd (N);
8676 R : constant Node_Id := Right_Opnd (N);
8677 T : Entity_Id;
8679 procedure Resolve_Set_Membership;
8680 -- Analysis has determined a unique type for the left operand. Use it to
8681 -- resolve the disjuncts.
8683 ----------------------------
8684 -- Resolve_Set_Membership --
8685 ----------------------------
8687 procedure Resolve_Set_Membership is
8688 Alt : Node_Id;
8689 Ltyp : constant Entity_Id := Etype (L);
8691 begin
8692 Resolve (L, Ltyp);
8694 Alt := First (Alternatives (N));
8695 while Present (Alt) loop
8697 -- Alternative is an expression, a range
8698 -- or a subtype mark.
8700 if not Is_Entity_Name (Alt)
8701 or else not Is_Type (Entity (Alt))
8702 then
8703 Resolve (Alt, Ltyp);
8704 end if;
8706 Next (Alt);
8707 end loop;
8709 -- Check for duplicates for discrete case
8711 if Is_Discrete_Type (Ltyp) then
8712 declare
8713 type Ent is record
8714 Alt : Node_Id;
8715 Val : Uint;
8716 end record;
8718 Alts : array (0 .. List_Length (Alternatives (N))) of Ent;
8719 Nalts : Nat;
8721 begin
8722 -- Loop checking duplicates. This is quadratic, but giant sets
8723 -- are unlikely in this context so it's a reasonable choice.
8725 Nalts := 0;
8726 Alt := First (Alternatives (N));
8727 while Present (Alt) loop
8728 if Is_OK_Static_Expression (Alt)
8729 and then (Nkind_In (Alt, N_Integer_Literal,
8730 N_Character_Literal)
8731 or else Nkind (Alt) in N_Has_Entity)
8732 then
8733 Nalts := Nalts + 1;
8734 Alts (Nalts) := (Alt, Expr_Value (Alt));
8736 for J in 1 .. Nalts - 1 loop
8737 if Alts (J).Val = Alts (Nalts).Val then
8738 Error_Msg_Sloc := Sloc (Alts (J).Alt);
8739 Error_Msg_N ("duplicate of value given#??", Alt);
8740 end if;
8741 end loop;
8742 end if;
8744 Alt := Next (Alt);
8745 end loop;
8746 end;
8747 end if;
8748 end Resolve_Set_Membership;
8750 -- Start of processing for Resolve_Membership_Op
8752 begin
8753 if L = Error or else R = Error then
8754 return;
8755 end if;
8757 if Present (Alternatives (N)) then
8758 Resolve_Set_Membership;
8759 goto SM_Exit;
8761 elsif not Is_Overloaded (R)
8762 and then
8763 (Etype (R) = Universal_Integer
8764 or else
8765 Etype (R) = Universal_Real)
8766 and then Is_Overloaded (L)
8767 then
8768 T := Etype (R);
8770 -- Ada 2005 (AI-251): Support the following case:
8772 -- type I is interface;
8773 -- type T is tagged ...
8775 -- function Test (O : I'Class) is
8776 -- begin
8777 -- return O in T'Class.
8778 -- end Test;
8780 -- In this case we have nothing else to do. The membership test will be
8781 -- done at run time.
8783 elsif Ada_Version >= Ada_2005
8784 and then Is_Class_Wide_Type (Etype (L))
8785 and then Is_Interface (Etype (L))
8786 and then Is_Class_Wide_Type (Etype (R))
8787 and then not Is_Interface (Etype (R))
8788 then
8789 return;
8790 else
8791 T := Intersect_Types (L, R);
8792 end if;
8794 -- If mixed-mode operations are present and operands are all literal,
8795 -- the only interpretation involves Duration, which is probably not
8796 -- the intention of the programmer.
8798 if T = Any_Fixed then
8799 T := Unique_Fixed_Point_Type (N);
8801 if T = Any_Type then
8802 return;
8803 end if;
8804 end if;
8806 Resolve (L, T);
8807 Check_Unset_Reference (L);
8809 if Nkind (R) = N_Range
8810 and then not Is_Scalar_Type (T)
8811 then
8812 Error_Msg_N ("scalar type required for range", R);
8813 end if;
8815 if Is_Entity_Name (R) then
8816 Freeze_Expression (R);
8817 else
8818 Resolve (R, T);
8819 Check_Unset_Reference (R);
8820 end if;
8822 -- Here after resolving membership operation
8824 <<SM_Exit>>
8826 Eval_Membership_Op (N);
8827 Check_Function_Writable_Actuals (N);
8828 end Resolve_Membership_Op;
8830 ------------------
8831 -- Resolve_Null --
8832 ------------------
8834 procedure Resolve_Null (N : Node_Id; Typ : Entity_Id) is
8835 Loc : constant Source_Ptr := Sloc (N);
8837 begin
8838 -- Handle restriction against anonymous null access values This
8839 -- restriction can be turned off using -gnatdj.
8841 -- Ada 2005 (AI-231): Remove restriction
8843 if Ada_Version < Ada_2005
8844 and then not Debug_Flag_J
8845 and then Ekind (Typ) = E_Anonymous_Access_Type
8846 and then Comes_From_Source (N)
8847 then
8848 -- In the common case of a call which uses an explicitly null value
8849 -- for an access parameter, give specialized error message.
8851 if Nkind (Parent (N)) in N_Subprogram_Call then
8852 Error_Msg_N
8853 ("null is not allowed as argument for an access parameter", N);
8855 -- Standard message for all other cases (are there any?)
8857 else
8858 Error_Msg_N
8859 ("null cannot be of an anonymous access type", N);
8860 end if;
8861 end if;
8863 -- Ada 2005 (AI-231): Generate the null-excluding check in case of
8864 -- assignment to a null-excluding object
8866 if Ada_Version >= Ada_2005
8867 and then Can_Never_Be_Null (Typ)
8868 and then Nkind (Parent (N)) = N_Assignment_Statement
8869 then
8870 if not Inside_Init_Proc then
8871 Insert_Action
8872 (Compile_Time_Constraint_Error (N,
8873 "(Ada 2005) null not allowed in null-excluding objects??"),
8874 Make_Raise_Constraint_Error (Loc,
8875 Reason => CE_Access_Check_Failed));
8876 else
8877 Insert_Action (N,
8878 Make_Raise_Constraint_Error (Loc,
8879 Reason => CE_Access_Check_Failed));
8880 end if;
8881 end if;
8883 -- In a distributed context, null for a remote access to subprogram may
8884 -- need to be replaced with a special record aggregate. In this case,
8885 -- return after having done the transformation.
8887 if (Ekind (Typ) = E_Record_Type
8888 or else Is_Remote_Access_To_Subprogram_Type (Typ))
8889 and then Remote_AST_Null_Value (N, Typ)
8890 then
8891 return;
8892 end if;
8894 -- The null literal takes its type from the context
8896 Set_Etype (N, Typ);
8897 end Resolve_Null;
8899 -----------------------
8900 -- Resolve_Op_Concat --
8901 -----------------------
8903 procedure Resolve_Op_Concat (N : Node_Id; Typ : Entity_Id) is
8905 -- We wish to avoid deep recursion, because concatenations are often
8906 -- deeply nested, as in A&B&...&Z. Therefore, we walk down the left
8907 -- operands nonrecursively until we find something that is not a simple
8908 -- concatenation (A in this case). We resolve that, and then walk back
8909 -- up the tree following Parent pointers, calling Resolve_Op_Concat_Rest
8910 -- to do the rest of the work at each level. The Parent pointers allow
8911 -- us to avoid recursion, and thus avoid running out of memory. See also
8912 -- Sem_Ch4.Analyze_Concatenation, where a similar approach is used.
8914 NN : Node_Id := N;
8915 Op1 : Node_Id;
8917 begin
8918 -- The following code is equivalent to:
8920 -- Resolve_Op_Concat_First (NN, Typ);
8921 -- Resolve_Op_Concat_Arg (N, ...);
8922 -- Resolve_Op_Concat_Rest (N, Typ);
8924 -- where the Resolve_Op_Concat_Arg call recurses back here if the left
8925 -- operand is a concatenation.
8927 -- Walk down left operands
8929 loop
8930 Resolve_Op_Concat_First (NN, Typ);
8931 Op1 := Left_Opnd (NN);
8932 exit when not (Nkind (Op1) = N_Op_Concat
8933 and then not Is_Array_Type (Component_Type (Typ))
8934 and then Entity (Op1) = Entity (NN));
8935 NN := Op1;
8936 end loop;
8938 -- Now (given the above example) NN is A&B and Op1 is A
8940 -- First resolve Op1 ...
8942 Resolve_Op_Concat_Arg (NN, Op1, Typ, Is_Component_Left_Opnd (NN));
8944 -- ... then walk NN back up until we reach N (where we started), calling
8945 -- Resolve_Op_Concat_Rest along the way.
8947 loop
8948 Resolve_Op_Concat_Rest (NN, Typ);
8949 exit when NN = N;
8950 NN := Parent (NN);
8951 end loop;
8953 if Base_Type (Etype (N)) /= Standard_String then
8954 Check_SPARK_05_Restriction
8955 ("result of concatenation should have type String", N);
8956 end if;
8957 end Resolve_Op_Concat;
8959 ---------------------------
8960 -- Resolve_Op_Concat_Arg --
8961 ---------------------------
8963 procedure Resolve_Op_Concat_Arg
8964 (N : Node_Id;
8965 Arg : Node_Id;
8966 Typ : Entity_Id;
8967 Is_Comp : Boolean)
8969 Btyp : constant Entity_Id := Base_Type (Typ);
8970 Ctyp : constant Entity_Id := Component_Type (Typ);
8972 begin
8973 if In_Instance then
8974 if Is_Comp
8975 or else (not Is_Overloaded (Arg)
8976 and then Etype (Arg) /= Any_Composite
8977 and then Covers (Ctyp, Etype (Arg)))
8978 then
8979 Resolve (Arg, Ctyp);
8980 else
8981 Resolve (Arg, Btyp);
8982 end if;
8984 -- If both Array & Array and Array & Component are visible, there is a
8985 -- potential ambiguity that must be reported.
8987 elsif Has_Compatible_Type (Arg, Ctyp) then
8988 if Nkind (Arg) = N_Aggregate
8989 and then Is_Composite_Type (Ctyp)
8990 then
8991 if Is_Private_Type (Ctyp) then
8992 Resolve (Arg, Btyp);
8994 -- If the operation is user-defined and not overloaded use its
8995 -- profile. The operation may be a renaming, in which case it has
8996 -- been rewritten, and we want the original profile.
8998 elsif not Is_Overloaded (N)
8999 and then Comes_From_Source (Entity (Original_Node (N)))
9000 and then Ekind (Entity (Original_Node (N))) = E_Function
9001 then
9002 Resolve (Arg,
9003 Etype
9004 (Next_Formal (First_Formal (Entity (Original_Node (N))))));
9005 return;
9007 -- Otherwise an aggregate may match both the array type and the
9008 -- component type.
9010 else
9011 Error_Msg_N ("ambiguous aggregate must be qualified", Arg);
9012 Set_Etype (Arg, Any_Type);
9013 end if;
9015 else
9016 if Is_Overloaded (Arg)
9017 and then Has_Compatible_Type (Arg, Typ)
9018 and then Etype (Arg) /= Any_Type
9019 then
9020 declare
9021 I : Interp_Index;
9022 It : Interp;
9023 Func : Entity_Id;
9025 begin
9026 Get_First_Interp (Arg, I, It);
9027 Func := It.Nam;
9028 Get_Next_Interp (I, It);
9030 -- Special-case the error message when the overloading is
9031 -- caused by a function that yields an array and can be
9032 -- called without parameters.
9034 if It.Nam = Func then
9035 Error_Msg_Sloc := Sloc (Func);
9036 Error_Msg_N ("ambiguous call to function#", Arg);
9037 Error_Msg_NE
9038 ("\\interpretation as call yields&", Arg, Typ);
9039 Error_Msg_NE
9040 ("\\interpretation as indexing of call yields&",
9041 Arg, Component_Type (Typ));
9043 else
9044 Error_Msg_N ("ambiguous operand for concatenation!", Arg);
9046 Get_First_Interp (Arg, I, It);
9047 while Present (It.Nam) loop
9048 Error_Msg_Sloc := Sloc (It.Nam);
9050 if Base_Type (It.Typ) = Btyp
9051 or else
9052 Base_Type (It.Typ) = Base_Type (Ctyp)
9053 then
9054 Error_Msg_N -- CODEFIX
9055 ("\\possible interpretation#", Arg);
9056 end if;
9058 Get_Next_Interp (I, It);
9059 end loop;
9060 end if;
9061 end;
9062 end if;
9064 Resolve (Arg, Component_Type (Typ));
9066 if Nkind (Arg) = N_String_Literal then
9067 Set_Etype (Arg, Component_Type (Typ));
9068 end if;
9070 if Arg = Left_Opnd (N) then
9071 Set_Is_Component_Left_Opnd (N);
9072 else
9073 Set_Is_Component_Right_Opnd (N);
9074 end if;
9075 end if;
9077 else
9078 Resolve (Arg, Btyp);
9079 end if;
9081 -- Concatenation is restricted in SPARK: each operand must be either a
9082 -- string literal, the name of a string constant, a static character or
9083 -- string expression, or another concatenation. Arg cannot be a
9084 -- concatenation here as callers of Resolve_Op_Concat_Arg call it
9085 -- separately on each final operand, past concatenation operations.
9087 if Is_Character_Type (Etype (Arg)) then
9088 if not Is_OK_Static_Expression (Arg) then
9089 Check_SPARK_05_Restriction
9090 ("character operand for concatenation should be static", Arg);
9091 end if;
9093 elsif Is_String_Type (Etype (Arg)) then
9094 if not (Nkind_In (Arg, N_Identifier, N_Expanded_Name)
9095 and then Is_Constant_Object (Entity (Arg)))
9096 and then not Is_OK_Static_Expression (Arg)
9097 then
9098 Check_SPARK_05_Restriction
9099 ("string operand for concatenation should be static", Arg);
9100 end if;
9102 -- Do not issue error on an operand that is neither a character nor a
9103 -- string, as the error is issued in Resolve_Op_Concat.
9105 else
9106 null;
9107 end if;
9109 Check_Unset_Reference (Arg);
9110 end Resolve_Op_Concat_Arg;
9112 -----------------------------
9113 -- Resolve_Op_Concat_First --
9114 -----------------------------
9116 procedure Resolve_Op_Concat_First (N : Node_Id; Typ : Entity_Id) is
9117 Btyp : constant Entity_Id := Base_Type (Typ);
9118 Op1 : constant Node_Id := Left_Opnd (N);
9119 Op2 : constant Node_Id := Right_Opnd (N);
9121 begin
9122 -- The parser folds an enormous sequence of concatenations of string
9123 -- literals into "" & "...", where the Is_Folded_In_Parser flag is set
9124 -- in the right operand. If the expression resolves to a predefined "&"
9125 -- operator, all is well. Otherwise, the parser's folding is wrong, so
9126 -- we give an error. See P_Simple_Expression in Par.Ch4.
9128 if Nkind (Op2) = N_String_Literal
9129 and then Is_Folded_In_Parser (Op2)
9130 and then Ekind (Entity (N)) = E_Function
9131 then
9132 pragma Assert (Nkind (Op1) = N_String_Literal -- should be ""
9133 and then String_Length (Strval (Op1)) = 0);
9134 Error_Msg_N ("too many user-defined concatenations", N);
9135 return;
9136 end if;
9138 Set_Etype (N, Btyp);
9140 if Is_Limited_Composite (Btyp) then
9141 Error_Msg_N ("concatenation not available for limited array", N);
9142 Explain_Limited_Type (Btyp, N);
9143 end if;
9144 end Resolve_Op_Concat_First;
9146 ----------------------------
9147 -- Resolve_Op_Concat_Rest --
9148 ----------------------------
9150 procedure Resolve_Op_Concat_Rest (N : Node_Id; Typ : Entity_Id) is
9151 Op1 : constant Node_Id := Left_Opnd (N);
9152 Op2 : constant Node_Id := Right_Opnd (N);
9154 begin
9155 Resolve_Op_Concat_Arg (N, Op2, Typ, Is_Component_Right_Opnd (N));
9157 Generate_Operator_Reference (N, Typ);
9159 if Is_String_Type (Typ) then
9160 Eval_Concatenation (N);
9161 end if;
9163 -- If this is not a static concatenation, but the result is a string
9164 -- type (and not an array of strings) ensure that static string operands
9165 -- have their subtypes properly constructed.
9167 if Nkind (N) /= N_String_Literal
9168 and then Is_Character_Type (Component_Type (Typ))
9169 then
9170 Set_String_Literal_Subtype (Op1, Typ);
9171 Set_String_Literal_Subtype (Op2, Typ);
9172 end if;
9173 end Resolve_Op_Concat_Rest;
9175 ----------------------
9176 -- Resolve_Op_Expon --
9177 ----------------------
9179 procedure Resolve_Op_Expon (N : Node_Id; Typ : Entity_Id) is
9180 B_Typ : constant Entity_Id := Base_Type (Typ);
9182 begin
9183 -- Catch attempts to do fixed-point exponentiation with universal
9184 -- operands, which is a case where the illegality is not caught during
9185 -- normal operator analysis. This is not done in preanalysis mode
9186 -- since the tree is not fully decorated during preanalysis.
9188 if Full_Analysis then
9189 if Is_Fixed_Point_Type (Typ) and then Comes_From_Source (N) then
9190 Error_Msg_N ("exponentiation not available for fixed point", N);
9191 return;
9193 elsif Nkind (Parent (N)) in N_Op
9194 and then Is_Fixed_Point_Type (Etype (Parent (N)))
9195 and then Etype (N) = Universal_Real
9196 and then Comes_From_Source (N)
9197 then
9198 Error_Msg_N ("exponentiation not available for fixed point", N);
9199 return;
9200 end if;
9201 end if;
9203 if Comes_From_Source (N)
9204 and then Ekind (Entity (N)) = E_Function
9205 and then Is_Imported (Entity (N))
9206 and then Is_Intrinsic_Subprogram (Entity (N))
9207 then
9208 Resolve_Intrinsic_Operator (N, Typ);
9209 return;
9210 end if;
9212 if Etype (Left_Opnd (N)) = Universal_Integer
9213 or else Etype (Left_Opnd (N)) = Universal_Real
9214 then
9215 Check_For_Visible_Operator (N, B_Typ);
9216 end if;
9218 -- We do the resolution using the base type, because intermediate values
9219 -- in expressions are always of the base type, not a subtype of it.
9221 Resolve (Left_Opnd (N), B_Typ);
9222 Resolve (Right_Opnd (N), Standard_Integer);
9224 -- For integer types, right argument must be in Natural range
9226 if Is_Integer_Type (Typ) then
9227 Apply_Scalar_Range_Check (Right_Opnd (N), Standard_Natural);
9228 end if;
9230 Check_Unset_Reference (Left_Opnd (N));
9231 Check_Unset_Reference (Right_Opnd (N));
9233 Set_Etype (N, B_Typ);
9234 Generate_Operator_Reference (N, B_Typ);
9236 Analyze_Dimension (N);
9238 if Ada_Version >= Ada_2012 and then Has_Dimension_System (B_Typ) then
9239 -- Evaluate the exponentiation operator for dimensioned type
9241 Eval_Op_Expon_For_Dimensioned_Type (N, B_Typ);
9242 else
9243 Eval_Op_Expon (N);
9244 end if;
9246 -- Set overflow checking bit. Much cleverer code needed here eventually
9247 -- and perhaps the Resolve routines should be separated for the various
9248 -- arithmetic operations, since they will need different processing. ???
9250 if Nkind (N) in N_Op then
9251 if not Overflow_Checks_Suppressed (Etype (N)) then
9252 Enable_Overflow_Check (N);
9253 end if;
9254 end if;
9255 end Resolve_Op_Expon;
9257 --------------------
9258 -- Resolve_Op_Not --
9259 --------------------
9261 procedure Resolve_Op_Not (N : Node_Id; Typ : Entity_Id) is
9262 B_Typ : Entity_Id;
9264 function Parent_Is_Boolean return Boolean;
9265 -- This function determines if the parent node is a boolean operator or
9266 -- operation (comparison op, membership test, or short circuit form) and
9267 -- the not in question is the left operand of this operation. Note that
9268 -- if the not is in parens, then false is returned.
9270 -----------------------
9271 -- Parent_Is_Boolean --
9272 -----------------------
9274 function Parent_Is_Boolean return Boolean is
9275 begin
9276 if Paren_Count (N) /= 0 then
9277 return False;
9279 else
9280 case Nkind (Parent (N)) is
9281 when N_Op_And |
9282 N_Op_Eq |
9283 N_Op_Ge |
9284 N_Op_Gt |
9285 N_Op_Le |
9286 N_Op_Lt |
9287 N_Op_Ne |
9288 N_Op_Or |
9289 N_Op_Xor |
9290 N_In |
9291 N_Not_In |
9292 N_And_Then |
9293 N_Or_Else =>
9295 return Left_Opnd (Parent (N)) = N;
9297 when others =>
9298 return False;
9299 end case;
9300 end if;
9301 end Parent_Is_Boolean;
9303 -- Start of processing for Resolve_Op_Not
9305 begin
9306 -- Predefined operations on scalar types yield the base type. On the
9307 -- other hand, logical operations on arrays yield the type of the
9308 -- arguments (and the context).
9310 if Is_Array_Type (Typ) then
9311 B_Typ := Typ;
9312 else
9313 B_Typ := Base_Type (Typ);
9314 end if;
9316 -- Straightforward case of incorrect arguments
9318 if not Valid_Boolean_Arg (Typ) then
9319 Error_Msg_N ("invalid operand type for operator&", N);
9320 Set_Etype (N, Any_Type);
9321 return;
9323 -- Special case of probable missing parens
9325 elsif Typ = Universal_Integer or else Typ = Any_Modular then
9326 if Parent_Is_Boolean then
9327 Error_Msg_N
9328 ("operand of not must be enclosed in parentheses",
9329 Right_Opnd (N));
9330 else
9331 Error_Msg_N
9332 ("no modular type available in this context", N);
9333 end if;
9335 Set_Etype (N, Any_Type);
9336 return;
9338 -- OK resolution of NOT
9340 else
9341 -- Warn if non-boolean types involved. This is a case like not a < b
9342 -- where a and b are modular, where we will get (not a) < b and most
9343 -- likely not (a < b) was intended.
9345 if Warn_On_Questionable_Missing_Parens
9346 and then not Is_Boolean_Type (Typ)
9347 and then Parent_Is_Boolean
9348 then
9349 Error_Msg_N ("?q?not expression should be parenthesized here!", N);
9350 end if;
9352 -- Warn on double negation if checking redundant constructs
9354 if Warn_On_Redundant_Constructs
9355 and then Comes_From_Source (N)
9356 and then Comes_From_Source (Right_Opnd (N))
9357 and then Root_Type (Typ) = Standard_Boolean
9358 and then Nkind (Right_Opnd (N)) = N_Op_Not
9359 then
9360 Error_Msg_N ("redundant double negation?r?", N);
9361 end if;
9363 -- Complete resolution and evaluation of NOT
9365 Resolve (Right_Opnd (N), B_Typ);
9366 Check_Unset_Reference (Right_Opnd (N));
9367 Set_Etype (N, B_Typ);
9368 Generate_Operator_Reference (N, B_Typ);
9369 Eval_Op_Not (N);
9370 end if;
9371 end Resolve_Op_Not;
9373 -----------------------------
9374 -- Resolve_Operator_Symbol --
9375 -----------------------------
9377 -- Nothing to be done, all resolved already
9379 procedure Resolve_Operator_Symbol (N : Node_Id; Typ : Entity_Id) is
9380 pragma Warnings (Off, N);
9381 pragma Warnings (Off, Typ);
9383 begin
9384 null;
9385 end Resolve_Operator_Symbol;
9387 ----------------------------------
9388 -- Resolve_Qualified_Expression --
9389 ----------------------------------
9391 procedure Resolve_Qualified_Expression (N : Node_Id; Typ : Entity_Id) is
9392 pragma Warnings (Off, Typ);
9394 Target_Typ : constant Entity_Id := Entity (Subtype_Mark (N));
9395 Expr : constant Node_Id := Expression (N);
9397 begin
9398 Resolve (Expr, Target_Typ);
9400 -- Protect call to Matching_Static_Array_Bounds to avoid costly
9401 -- operation if not needed.
9403 if Restriction_Check_Required (SPARK_05)
9404 and then Is_Array_Type (Target_Typ)
9405 and then Is_Array_Type (Etype (Expr))
9406 and then Etype (Expr) /= Any_Composite -- or else Expr in error
9407 and then not Matching_Static_Array_Bounds (Target_Typ, Etype (Expr))
9408 then
9409 Check_SPARK_05_Restriction
9410 ("array types should have matching static bounds", N);
9411 end if;
9413 -- A qualified expression requires an exact match of the type, class-
9414 -- wide matching is not allowed. However, if the qualifying type is
9415 -- specific and the expression has a class-wide type, it may still be
9416 -- okay, since it can be the result of the expansion of a call to a
9417 -- dispatching function, so we also have to check class-wideness of the
9418 -- type of the expression's original node.
9420 if (Is_Class_Wide_Type (Target_Typ)
9421 or else
9422 (Is_Class_Wide_Type (Etype (Expr))
9423 and then Is_Class_Wide_Type (Etype (Original_Node (Expr)))))
9424 and then Base_Type (Etype (Expr)) /= Base_Type (Target_Typ)
9425 then
9426 Wrong_Type (Expr, Target_Typ);
9427 end if;
9429 -- If the target type is unconstrained, then we reset the type of the
9430 -- result from the type of the expression. For other cases, the actual
9431 -- subtype of the expression is the target type.
9433 if Is_Composite_Type (Target_Typ)
9434 and then not Is_Constrained (Target_Typ)
9435 then
9436 Set_Etype (N, Etype (Expr));
9437 end if;
9439 Analyze_Dimension (N);
9440 Eval_Qualified_Expression (N);
9442 -- If we still have a qualified expression after the static evaluation,
9443 -- then apply a scalar range check if needed. The reason that we do this
9444 -- after the Eval call is that otherwise, the application of the range
9445 -- check may convert an illegal static expression and result in warning
9446 -- rather than giving an error (e.g Integer'(Integer'Last + 1)).
9448 if Nkind (N) = N_Qualified_Expression and then Is_Scalar_Type (Typ) then
9449 Apply_Scalar_Range_Check (Expr, Typ);
9450 end if;
9451 end Resolve_Qualified_Expression;
9453 ------------------------------
9454 -- Resolve_Raise_Expression --
9455 ------------------------------
9457 procedure Resolve_Raise_Expression (N : Node_Id; Typ : Entity_Id) is
9458 begin
9459 if Typ = Raise_Type then
9460 Error_Msg_N ("cannot find unique type for raise expression", N);
9461 Set_Etype (N, Any_Type);
9462 else
9463 Set_Etype (N, Typ);
9464 end if;
9465 end Resolve_Raise_Expression;
9467 -------------------
9468 -- Resolve_Range --
9469 -------------------
9471 procedure Resolve_Range (N : Node_Id; Typ : Entity_Id) is
9472 L : constant Node_Id := Low_Bound (N);
9473 H : constant Node_Id := High_Bound (N);
9475 function First_Last_Ref return Boolean;
9476 -- Returns True if N is of the form X'First .. X'Last where X is the
9477 -- same entity for both attributes.
9479 --------------------
9480 -- First_Last_Ref --
9481 --------------------
9483 function First_Last_Ref return Boolean is
9484 Lorig : constant Node_Id := Original_Node (L);
9485 Horig : constant Node_Id := Original_Node (H);
9487 begin
9488 if Nkind (Lorig) = N_Attribute_Reference
9489 and then Nkind (Horig) = N_Attribute_Reference
9490 and then Attribute_Name (Lorig) = Name_First
9491 and then Attribute_Name (Horig) = Name_Last
9492 then
9493 declare
9494 PL : constant Node_Id := Prefix (Lorig);
9495 PH : constant Node_Id := Prefix (Horig);
9496 begin
9497 if Is_Entity_Name (PL)
9498 and then Is_Entity_Name (PH)
9499 and then Entity (PL) = Entity (PH)
9500 then
9501 return True;
9502 end if;
9503 end;
9504 end if;
9506 return False;
9507 end First_Last_Ref;
9509 -- Start of processing for Resolve_Range
9511 begin
9512 Set_Etype (N, Typ);
9513 Resolve (L, Typ);
9514 Resolve (H, Typ);
9516 -- Check for inappropriate range on unordered enumeration type
9518 if Bad_Unordered_Enumeration_Reference (N, Typ)
9520 -- Exclude X'First .. X'Last if X is the same entity for both
9522 and then not First_Last_Ref
9523 then
9524 Error_Msg_Sloc := Sloc (Typ);
9525 Error_Msg_NE
9526 ("subrange of unordered enumeration type& declared#?U?", N, Typ);
9527 end if;
9529 Check_Unset_Reference (L);
9530 Check_Unset_Reference (H);
9532 -- We have to check the bounds for being within the base range as
9533 -- required for a non-static context. Normally this is automatic and
9534 -- done as part of evaluating expressions, but the N_Range node is an
9535 -- exception, since in GNAT we consider this node to be a subexpression,
9536 -- even though in Ada it is not. The circuit in Sem_Eval could check for
9537 -- this, but that would put the test on the main evaluation path for
9538 -- expressions.
9540 Check_Non_Static_Context (L);
9541 Check_Non_Static_Context (H);
9543 -- Check for an ambiguous range over character literals. This will
9544 -- happen with a membership test involving only literals.
9546 if Typ = Any_Character then
9547 Ambiguous_Character (L);
9548 Set_Etype (N, Any_Type);
9549 return;
9550 end if;
9552 -- If bounds are static, constant-fold them, so size computations are
9553 -- identical between front-end and back-end. Do not perform this
9554 -- transformation while analyzing generic units, as type information
9555 -- would be lost when reanalyzing the constant node in the instance.
9557 if Is_Discrete_Type (Typ) and then Expander_Active then
9558 if Is_OK_Static_Expression (L) then
9559 Fold_Uint (L, Expr_Value (L), Is_OK_Static_Expression (L));
9560 end if;
9562 if Is_OK_Static_Expression (H) then
9563 Fold_Uint (H, Expr_Value (H), Is_OK_Static_Expression (H));
9564 end if;
9565 end if;
9566 end Resolve_Range;
9568 --------------------------
9569 -- Resolve_Real_Literal --
9570 --------------------------
9572 procedure Resolve_Real_Literal (N : Node_Id; Typ : Entity_Id) is
9573 Actual_Typ : constant Entity_Id := Etype (N);
9575 begin
9576 -- Special processing for fixed-point literals to make sure that the
9577 -- value is an exact multiple of small where this is required. We skip
9578 -- this for the universal real case, and also for generic types.
9580 if Is_Fixed_Point_Type (Typ)
9581 and then Typ /= Universal_Fixed
9582 and then Typ /= Any_Fixed
9583 and then not Is_Generic_Type (Typ)
9584 then
9585 declare
9586 Val : constant Ureal := Realval (N);
9587 Cintr : constant Ureal := Val / Small_Value (Typ);
9588 Cint : constant Uint := UR_Trunc (Cintr);
9589 Den : constant Uint := Norm_Den (Cintr);
9590 Stat : Boolean;
9592 begin
9593 -- Case of literal is not an exact multiple of the Small
9595 if Den /= 1 then
9597 -- For a source program literal for a decimal fixed-point type,
9598 -- this is statically illegal (RM 4.9(36)).
9600 if Is_Decimal_Fixed_Point_Type (Typ)
9601 and then Actual_Typ = Universal_Real
9602 and then Comes_From_Source (N)
9603 then
9604 Error_Msg_N ("value has extraneous low order digits", N);
9605 end if;
9607 -- Generate a warning if literal from source
9609 if Is_OK_Static_Expression (N)
9610 and then Warn_On_Bad_Fixed_Value
9611 then
9612 Error_Msg_N
9613 ("?b?static fixed-point value is not a multiple of Small!",
9615 end if;
9617 -- Replace literal by a value that is the exact representation
9618 -- of a value of the type, i.e. a multiple of the small value,
9619 -- by truncation, since Machine_Rounds is false for all GNAT
9620 -- fixed-point types (RM 4.9(38)).
9622 Stat := Is_OK_Static_Expression (N);
9623 Rewrite (N,
9624 Make_Real_Literal (Sloc (N),
9625 Realval => Small_Value (Typ) * Cint));
9627 Set_Is_Static_Expression (N, Stat);
9628 end if;
9630 -- In all cases, set the corresponding integer field
9632 Set_Corresponding_Integer_Value (N, Cint);
9633 end;
9634 end if;
9636 -- Now replace the actual type by the expected type as usual
9638 Set_Etype (N, Typ);
9639 Eval_Real_Literal (N);
9640 end Resolve_Real_Literal;
9642 -----------------------
9643 -- Resolve_Reference --
9644 -----------------------
9646 procedure Resolve_Reference (N : Node_Id; Typ : Entity_Id) is
9647 P : constant Node_Id := Prefix (N);
9649 begin
9650 -- Replace general access with specific type
9652 if Ekind (Etype (N)) = E_Allocator_Type then
9653 Set_Etype (N, Base_Type (Typ));
9654 end if;
9656 Resolve (P, Designated_Type (Etype (N)));
9658 -- If we are taking the reference of a volatile entity, then treat it as
9659 -- a potential modification of this entity. This is too conservative,
9660 -- but necessary because remove side effects can cause transformations
9661 -- of normal assignments into reference sequences that otherwise fail to
9662 -- notice the modification.
9664 if Is_Entity_Name (P) and then Treat_As_Volatile (Entity (P)) then
9665 Note_Possible_Modification (P, Sure => False);
9666 end if;
9667 end Resolve_Reference;
9669 --------------------------------
9670 -- Resolve_Selected_Component --
9671 --------------------------------
9673 procedure Resolve_Selected_Component (N : Node_Id; Typ : Entity_Id) is
9674 Comp : Entity_Id;
9675 Comp1 : Entity_Id := Empty; -- prevent junk warning
9676 P : constant Node_Id := Prefix (N);
9677 S : constant Node_Id := Selector_Name (N);
9678 T : Entity_Id := Etype (P);
9679 I : Interp_Index;
9680 I1 : Interp_Index := 0; -- prevent junk warning
9681 It : Interp;
9682 It1 : Interp;
9683 Found : Boolean;
9685 function Init_Component return Boolean;
9686 -- Check whether this is the initialization of a component within an
9687 -- init proc (by assignment or call to another init proc). If true,
9688 -- there is no need for a discriminant check.
9690 --------------------
9691 -- Init_Component --
9692 --------------------
9694 function Init_Component return Boolean is
9695 begin
9696 return Inside_Init_Proc
9697 and then Nkind (Prefix (N)) = N_Identifier
9698 and then Chars (Prefix (N)) = Name_uInit
9699 and then Nkind (Parent (Parent (N))) = N_Case_Statement_Alternative;
9700 end Init_Component;
9702 -- Start of processing for Resolve_Selected_Component
9704 begin
9705 if Is_Overloaded (P) then
9707 -- Use the context type to select the prefix that has a selector
9708 -- of the correct name and type.
9710 Found := False;
9711 Get_First_Interp (P, I, It);
9713 Search : while Present (It.Typ) loop
9714 if Is_Access_Type (It.Typ) then
9715 T := Designated_Type (It.Typ);
9716 else
9717 T := It.Typ;
9718 end if;
9720 -- Locate selected component. For a private prefix the selector
9721 -- can denote a discriminant.
9723 if Is_Record_Type (T) or else Is_Private_Type (T) then
9725 -- The visible components of a class-wide type are those of
9726 -- the root type.
9728 if Is_Class_Wide_Type (T) then
9729 T := Etype (T);
9730 end if;
9732 Comp := First_Entity (T);
9733 while Present (Comp) loop
9734 if Chars (Comp) = Chars (S)
9735 and then Covers (Typ, Etype (Comp))
9736 then
9737 if not Found then
9738 Found := True;
9739 I1 := I;
9740 It1 := It;
9741 Comp1 := Comp;
9743 else
9744 It := Disambiguate (P, I1, I, Any_Type);
9746 if It = No_Interp then
9747 Error_Msg_N
9748 ("ambiguous prefix for selected component", N);
9749 Set_Etype (N, Typ);
9750 return;
9752 else
9753 It1 := It;
9755 -- There may be an implicit dereference. Retrieve
9756 -- designated record type.
9758 if Is_Access_Type (It1.Typ) then
9759 T := Designated_Type (It1.Typ);
9760 else
9761 T := It1.Typ;
9762 end if;
9764 if Scope (Comp1) /= T then
9766 -- Resolution chooses the new interpretation.
9767 -- Find the component with the right name.
9769 Comp1 := First_Entity (T);
9770 while Present (Comp1)
9771 and then Chars (Comp1) /= Chars (S)
9772 loop
9773 Comp1 := Next_Entity (Comp1);
9774 end loop;
9775 end if;
9777 exit Search;
9778 end if;
9779 end if;
9780 end if;
9782 Comp := Next_Entity (Comp);
9783 end loop;
9784 end if;
9786 Get_Next_Interp (I, It);
9787 end loop Search;
9789 -- There must be a legal interpretation at this point
9791 pragma Assert (Found);
9792 Resolve (P, It1.Typ);
9793 Set_Etype (N, Typ);
9794 Set_Entity_With_Checks (S, Comp1);
9796 else
9797 -- Resolve prefix with its type
9799 Resolve (P, T);
9800 end if;
9802 -- Generate cross-reference. We needed to wait until full overloading
9803 -- resolution was complete to do this, since otherwise we can't tell if
9804 -- we are an lvalue or not.
9806 if May_Be_Lvalue (N) then
9807 Generate_Reference (Entity (S), S, 'm');
9808 else
9809 Generate_Reference (Entity (S), S, 'r');
9810 end if;
9812 -- If prefix is an access type, the node will be transformed into an
9813 -- explicit dereference during expansion. The type of the node is the
9814 -- designated type of that of the prefix.
9816 if Is_Access_Type (Etype (P)) then
9817 T := Designated_Type (Etype (P));
9818 Check_Fully_Declared_Prefix (T, P);
9819 else
9820 T := Etype (P);
9821 end if;
9823 -- Set flag for expander if discriminant check required
9825 if Has_Discriminants (T)
9826 and then Ekind_In (Entity (S), E_Component, E_Discriminant)
9827 and then Present (Original_Record_Component (Entity (S)))
9828 and then Ekind (Original_Record_Component (Entity (S))) = E_Component
9829 and then not Discriminant_Checks_Suppressed (T)
9830 and then not Init_Component
9831 then
9832 Set_Do_Discriminant_Check (N);
9833 end if;
9835 if Ekind (Entity (S)) = E_Void then
9836 Error_Msg_N ("premature use of component", S);
9837 end if;
9839 -- If the prefix is a record conversion, this may be a renamed
9840 -- discriminant whose bounds differ from those of the original
9841 -- one, so we must ensure that a range check is performed.
9843 if Nkind (P) = N_Type_Conversion
9844 and then Ekind (Entity (S)) = E_Discriminant
9845 and then Is_Discrete_Type (Typ)
9846 then
9847 Set_Etype (N, Base_Type (Typ));
9848 end if;
9850 -- Note: No Eval processing is required, because the prefix is of a
9851 -- record type, or protected type, and neither can possibly be static.
9853 -- If the record type is atomic, and the component is non-atomic, then
9854 -- this is worth a warning, since we have a situation where the access
9855 -- to the component may cause extra read/writes of the atomic array
9856 -- object, or partial word accesses, both of which may be unexpected.
9858 if Nkind (N) = N_Selected_Component
9859 and then Is_Atomic_Ref_With_Address (N)
9860 and then not Is_Atomic (Entity (S))
9861 and then not Is_Atomic (Etype (Entity (S)))
9862 then
9863 Error_Msg_N
9864 ("??access to non-atomic component of atomic record",
9865 Prefix (N));
9866 Error_Msg_N
9867 ("\??may cause unexpected accesses to atomic object",
9868 Prefix (N));
9869 end if;
9871 Analyze_Dimension (N);
9872 end Resolve_Selected_Component;
9874 -------------------
9875 -- Resolve_Shift --
9876 -------------------
9878 procedure Resolve_Shift (N : Node_Id; Typ : Entity_Id) is
9879 B_Typ : constant Entity_Id := Base_Type (Typ);
9880 L : constant Node_Id := Left_Opnd (N);
9881 R : constant Node_Id := Right_Opnd (N);
9883 begin
9884 -- We do the resolution using the base type, because intermediate values
9885 -- in expressions always are of the base type, not a subtype of it.
9887 Resolve (L, B_Typ);
9888 Resolve (R, Standard_Natural);
9890 Check_Unset_Reference (L);
9891 Check_Unset_Reference (R);
9893 Set_Etype (N, B_Typ);
9894 Generate_Operator_Reference (N, B_Typ);
9895 Eval_Shift (N);
9896 end Resolve_Shift;
9898 ---------------------------
9899 -- Resolve_Short_Circuit --
9900 ---------------------------
9902 procedure Resolve_Short_Circuit (N : Node_Id; Typ : Entity_Id) is
9903 B_Typ : constant Entity_Id := Base_Type (Typ);
9904 L : constant Node_Id := Left_Opnd (N);
9905 R : constant Node_Id := Right_Opnd (N);
9907 begin
9908 -- Ensure all actions associated with the left operand (e.g.
9909 -- finalization of transient controlled objects) are fully evaluated
9910 -- locally within an expression with actions. This is particularly
9911 -- helpful for coverage analysis. However this should not happen in
9912 -- generics.
9914 if Expander_Active then
9915 declare
9916 Reloc_L : constant Node_Id := Relocate_Node (L);
9917 begin
9918 Save_Interps (Old_N => L, New_N => Reloc_L);
9920 Rewrite (L,
9921 Make_Expression_With_Actions (Sloc (L),
9922 Actions => New_List,
9923 Expression => Reloc_L));
9925 -- Set Comes_From_Source on L to preserve warnings for unset
9926 -- reference.
9928 Set_Comes_From_Source (L, Comes_From_Source (Reloc_L));
9929 end;
9930 end if;
9932 Resolve (L, B_Typ);
9933 Resolve (R, B_Typ);
9935 -- Check for issuing warning for always False assert/check, this happens
9936 -- when assertions are turned off, in which case the pragma Assert/Check
9937 -- was transformed into:
9939 -- if False and then <condition> then ...
9941 -- and we detect this pattern
9943 if Warn_On_Assertion_Failure
9944 and then Is_Entity_Name (R)
9945 and then Entity (R) = Standard_False
9946 and then Nkind (Parent (N)) = N_If_Statement
9947 and then Nkind (N) = N_And_Then
9948 and then Is_Entity_Name (L)
9949 and then Entity (L) = Standard_False
9950 then
9951 declare
9952 Orig : constant Node_Id := Original_Node (Parent (N));
9954 begin
9955 -- Special handling of Asssert pragma
9957 if Nkind (Orig) = N_Pragma
9958 and then Pragma_Name (Orig) = Name_Assert
9959 then
9960 declare
9961 Expr : constant Node_Id :=
9962 Original_Node
9963 (Expression
9964 (First (Pragma_Argument_Associations (Orig))));
9966 begin
9967 -- Don't warn if original condition is explicit False,
9968 -- since obviously the failure is expected in this case.
9970 if Is_Entity_Name (Expr)
9971 and then Entity (Expr) = Standard_False
9972 then
9973 null;
9975 -- Issue warning. We do not want the deletion of the
9976 -- IF/AND-THEN to take this message with it. We achieve this
9977 -- by making sure that the expanded code points to the Sloc
9978 -- of the expression, not the original pragma.
9980 else
9981 -- Note: Use Error_Msg_F here rather than Error_Msg_N.
9982 -- The source location of the expression is not usually
9983 -- the best choice here. For example, it gets located on
9984 -- the last AND keyword in a chain of boolean expressiond
9985 -- AND'ed together. It is best to put the message on the
9986 -- first character of the assertion, which is the effect
9987 -- of the First_Node call here.
9989 Error_Msg_F
9990 ("?A?assertion would fail at run time!",
9991 Expression
9992 (First (Pragma_Argument_Associations (Orig))));
9993 end if;
9994 end;
9996 -- Similar processing for Check pragma
9998 elsif Nkind (Orig) = N_Pragma
9999 and then Pragma_Name (Orig) = Name_Check
10000 then
10001 -- Don't want to warn if original condition is explicit False
10003 declare
10004 Expr : constant Node_Id :=
10005 Original_Node
10006 (Expression
10007 (Next (First (Pragma_Argument_Associations (Orig)))));
10008 begin
10009 if Is_Entity_Name (Expr)
10010 and then Entity (Expr) = Standard_False
10011 then
10012 null;
10014 -- Post warning
10016 else
10017 -- Again use Error_Msg_F rather than Error_Msg_N, see
10018 -- comment above for an explanation of why we do this.
10020 Error_Msg_F
10021 ("?A?check would fail at run time!",
10022 Expression
10023 (Last (Pragma_Argument_Associations (Orig))));
10024 end if;
10025 end;
10026 end if;
10027 end;
10028 end if;
10030 -- Continue with processing of short circuit
10032 Check_Unset_Reference (L);
10033 Check_Unset_Reference (R);
10035 Set_Etype (N, B_Typ);
10036 Eval_Short_Circuit (N);
10037 end Resolve_Short_Circuit;
10039 -------------------
10040 -- Resolve_Slice --
10041 -------------------
10043 procedure Resolve_Slice (N : Node_Id; Typ : Entity_Id) is
10044 Drange : constant Node_Id := Discrete_Range (N);
10045 Name : constant Node_Id := Prefix (N);
10046 Array_Type : Entity_Id := Empty;
10047 Dexpr : Node_Id := Empty;
10048 Index_Type : Entity_Id;
10050 begin
10051 if Is_Overloaded (Name) then
10053 -- Use the context type to select the prefix that yields the correct
10054 -- array type.
10056 declare
10057 I : Interp_Index;
10058 I1 : Interp_Index := 0;
10059 It : Interp;
10060 P : constant Node_Id := Prefix (N);
10061 Found : Boolean := False;
10063 begin
10064 Get_First_Interp (P, I, It);
10065 while Present (It.Typ) loop
10066 if (Is_Array_Type (It.Typ)
10067 and then Covers (Typ, It.Typ))
10068 or else (Is_Access_Type (It.Typ)
10069 and then Is_Array_Type (Designated_Type (It.Typ))
10070 and then Covers (Typ, Designated_Type (It.Typ)))
10071 then
10072 if Found then
10073 It := Disambiguate (P, I1, I, Any_Type);
10075 if It = No_Interp then
10076 Error_Msg_N ("ambiguous prefix for slicing", N);
10077 Set_Etype (N, Typ);
10078 return;
10079 else
10080 Found := True;
10081 Array_Type := It.Typ;
10082 I1 := I;
10083 end if;
10084 else
10085 Found := True;
10086 Array_Type := It.Typ;
10087 I1 := I;
10088 end if;
10089 end if;
10091 Get_Next_Interp (I, It);
10092 end loop;
10093 end;
10095 else
10096 Array_Type := Etype (Name);
10097 end if;
10099 Resolve (Name, Array_Type);
10101 if Is_Access_Type (Array_Type) then
10102 Apply_Access_Check (N);
10103 Array_Type := Designated_Type (Array_Type);
10105 -- If the prefix is an access to an unconstrained array, we must use
10106 -- the actual subtype of the object to perform the index checks. The
10107 -- object denoted by the prefix is implicit in the node, so we build
10108 -- an explicit representation for it in order to compute the actual
10109 -- subtype.
10111 if not Is_Constrained (Array_Type) then
10112 Remove_Side_Effects (Prefix (N));
10114 declare
10115 Obj : constant Node_Id :=
10116 Make_Explicit_Dereference (Sloc (N),
10117 Prefix => New_Copy_Tree (Prefix (N)));
10118 begin
10119 Set_Etype (Obj, Array_Type);
10120 Set_Parent (Obj, Parent (N));
10121 Array_Type := Get_Actual_Subtype (Obj);
10122 end;
10123 end if;
10125 elsif Is_Entity_Name (Name)
10126 or else Nkind (Name) = N_Explicit_Dereference
10127 or else (Nkind (Name) = N_Function_Call
10128 and then not Is_Constrained (Etype (Name)))
10129 then
10130 Array_Type := Get_Actual_Subtype (Name);
10132 -- If the name is a selected component that depends on discriminants,
10133 -- build an actual subtype for it. This can happen only when the name
10134 -- itself is overloaded; otherwise the actual subtype is created when
10135 -- the selected component is analyzed.
10137 elsif Nkind (Name) = N_Selected_Component
10138 and then Full_Analysis
10139 and then Depends_On_Discriminant (First_Index (Array_Type))
10140 then
10141 declare
10142 Act_Decl : constant Node_Id :=
10143 Build_Actual_Subtype_Of_Component (Array_Type, Name);
10144 begin
10145 Insert_Action (N, Act_Decl);
10146 Array_Type := Defining_Identifier (Act_Decl);
10147 end;
10149 -- Maybe this should just be "else", instead of checking for the
10150 -- specific case of slice??? This is needed for the case where the
10151 -- prefix is an Image attribute, which gets expanded to a slice, and so
10152 -- has a constrained subtype which we want to use for the slice range
10153 -- check applied below (the range check won't get done if the
10154 -- unconstrained subtype of the 'Image is used).
10156 elsif Nkind (Name) = N_Slice then
10157 Array_Type := Etype (Name);
10158 end if;
10160 -- Obtain the type of the array index
10162 if Ekind (Array_Type) = E_String_Literal_Subtype then
10163 Index_Type := Etype (String_Literal_Low_Bound (Array_Type));
10164 else
10165 Index_Type := Etype (First_Index (Array_Type));
10166 end if;
10168 -- If name was overloaded, set slice type correctly now
10170 Set_Etype (N, Array_Type);
10172 -- Handle the generation of a range check that compares the array index
10173 -- against the discrete_range. The check is not applied to internally
10174 -- built nodes associated with the expansion of dispatch tables. Check
10175 -- that Ada.Tags has already been loaded to avoid extra dependencies on
10176 -- the unit.
10178 if Tagged_Type_Expansion
10179 and then RTU_Loaded (Ada_Tags)
10180 and then Nkind (Prefix (N)) = N_Selected_Component
10181 and then Present (Entity (Selector_Name (Prefix (N))))
10182 and then Entity (Selector_Name (Prefix (N))) =
10183 RTE_Record_Component (RE_Prims_Ptr)
10184 then
10185 null;
10187 -- The discrete_range is specified by a subtype indication. Create a
10188 -- shallow copy and inherit the type, parent and source location from
10189 -- the discrete_range. This ensures that the range check is inserted
10190 -- relative to the slice and that the runtime exception points to the
10191 -- proper construct.
10193 elsif Is_Entity_Name (Drange) then
10194 Dexpr := New_Copy (Scalar_Range (Entity (Drange)));
10196 Set_Etype (Dexpr, Etype (Drange));
10197 Set_Parent (Dexpr, Parent (Drange));
10198 Set_Sloc (Dexpr, Sloc (Drange));
10200 -- The discrete_range is a regular range. Resolve the bounds and remove
10201 -- their side effects.
10203 else
10204 Resolve (Drange, Base_Type (Index_Type));
10206 if Nkind (Drange) = N_Range then
10207 Force_Evaluation (Low_Bound (Drange));
10208 Force_Evaluation (High_Bound (Drange));
10210 Dexpr := Drange;
10211 end if;
10212 end if;
10214 if Present (Dexpr) then
10215 Apply_Range_Check (Dexpr, Index_Type);
10216 end if;
10218 Set_Slice_Subtype (N);
10220 -- Check bad use of type with predicates
10222 declare
10223 Subt : Entity_Id;
10225 begin
10226 if Nkind (Drange) = N_Subtype_Indication
10227 and then Has_Predicates (Entity (Subtype_Mark (Drange)))
10228 then
10229 Subt := Entity (Subtype_Mark (Drange));
10230 else
10231 Subt := Etype (Drange);
10232 end if;
10234 if Has_Predicates (Subt) then
10235 Bad_Predicated_Subtype_Use
10236 ("subtype& has predicate, not allowed in slice", Drange, Subt);
10237 end if;
10238 end;
10240 -- Otherwise here is where we check suspicious indexes
10242 if Nkind (Drange) = N_Range then
10243 Warn_On_Suspicious_Index (Name, Low_Bound (Drange));
10244 Warn_On_Suspicious_Index (Name, High_Bound (Drange));
10245 end if;
10247 Analyze_Dimension (N);
10248 Eval_Slice (N);
10249 end Resolve_Slice;
10251 ----------------------------
10252 -- Resolve_String_Literal --
10253 ----------------------------
10255 procedure Resolve_String_Literal (N : Node_Id; Typ : Entity_Id) is
10256 C_Typ : constant Entity_Id := Component_Type (Typ);
10257 R_Typ : constant Entity_Id := Root_Type (C_Typ);
10258 Loc : constant Source_Ptr := Sloc (N);
10259 Str : constant String_Id := Strval (N);
10260 Strlen : constant Nat := String_Length (Str);
10261 Subtype_Id : Entity_Id;
10262 Need_Check : Boolean;
10264 begin
10265 -- For a string appearing in a concatenation, defer creation of the
10266 -- string_literal_subtype until the end of the resolution of the
10267 -- concatenation, because the literal may be constant-folded away. This
10268 -- is a useful optimization for long concatenation expressions.
10270 -- If the string is an aggregate built for a single character (which
10271 -- happens in a non-static context) or a is null string to which special
10272 -- checks may apply, we build the subtype. Wide strings must also get a
10273 -- string subtype if they come from a one character aggregate. Strings
10274 -- generated by attributes might be static, but it is often hard to
10275 -- determine whether the enclosing context is static, so we generate
10276 -- subtypes for them as well, thus losing some rarer optimizations ???
10277 -- Same for strings that come from a static conversion.
10279 Need_Check :=
10280 (Strlen = 0 and then Typ /= Standard_String)
10281 or else Nkind (Parent (N)) /= N_Op_Concat
10282 or else (N /= Left_Opnd (Parent (N))
10283 and then N /= Right_Opnd (Parent (N)))
10284 or else ((Typ = Standard_Wide_String
10285 or else Typ = Standard_Wide_Wide_String)
10286 and then Nkind (Original_Node (N)) /= N_String_Literal);
10288 -- If the resolving type is itself a string literal subtype, we can just
10289 -- reuse it, since there is no point in creating another.
10291 if Ekind (Typ) = E_String_Literal_Subtype then
10292 Subtype_Id := Typ;
10294 elsif Nkind (Parent (N)) = N_Op_Concat
10295 and then not Need_Check
10296 and then not Nkind_In (Original_Node (N), N_Character_Literal,
10297 N_Attribute_Reference,
10298 N_Qualified_Expression,
10299 N_Type_Conversion)
10300 then
10301 Subtype_Id := Typ;
10303 -- Do not generate a string literal subtype for the default expression
10304 -- of a formal parameter in GNATprove mode. This is because the string
10305 -- subtype is associated with the freezing actions of the subprogram,
10306 -- however freezing is disabled in GNATprove mode and as a result the
10307 -- subtype is unavailable.
10309 elsif GNATprove_Mode
10310 and then Nkind (Parent (N)) = N_Parameter_Specification
10311 then
10312 Subtype_Id := Typ;
10314 -- Otherwise we must create a string literal subtype. Note that the
10315 -- whole idea of string literal subtypes is simply to avoid the need
10316 -- for building a full fledged array subtype for each literal.
10318 else
10319 Set_String_Literal_Subtype (N, Typ);
10320 Subtype_Id := Etype (N);
10321 end if;
10323 if Nkind (Parent (N)) /= N_Op_Concat
10324 or else Need_Check
10325 then
10326 Set_Etype (N, Subtype_Id);
10327 Eval_String_Literal (N);
10328 end if;
10330 if Is_Limited_Composite (Typ)
10331 or else Is_Private_Composite (Typ)
10332 then
10333 Error_Msg_N ("string literal not available for private array", N);
10334 Set_Etype (N, Any_Type);
10335 return;
10336 end if;
10338 -- The validity of a null string has been checked in the call to
10339 -- Eval_String_Literal.
10341 if Strlen = 0 then
10342 return;
10344 -- Always accept string literal with component type Any_Character, which
10345 -- occurs in error situations and in comparisons of literals, both of
10346 -- which should accept all literals.
10348 elsif R_Typ = Any_Character then
10349 return;
10351 -- If the type is bit-packed, then we always transform the string
10352 -- literal into a full fledged aggregate.
10354 elsif Is_Bit_Packed_Array (Typ) then
10355 null;
10357 -- Deal with cases of Wide_Wide_String, Wide_String, and String
10359 else
10360 -- For Standard.Wide_Wide_String, or any other type whose component
10361 -- type is Standard.Wide_Wide_Character, we know that all the
10362 -- characters in the string must be acceptable, since the parser
10363 -- accepted the characters as valid character literals.
10365 if R_Typ = Standard_Wide_Wide_Character then
10366 null;
10368 -- For the case of Standard.String, or any other type whose component
10369 -- type is Standard.Character, we must make sure that there are no
10370 -- wide characters in the string, i.e. that it is entirely composed
10371 -- of characters in range of type Character.
10373 -- If the string literal is the result of a static concatenation, the
10374 -- test has already been performed on the components, and need not be
10375 -- repeated.
10377 elsif R_Typ = Standard_Character
10378 and then Nkind (Original_Node (N)) /= N_Op_Concat
10379 then
10380 for J in 1 .. Strlen loop
10381 if not In_Character_Range (Get_String_Char (Str, J)) then
10383 -- If we are out of range, post error. This is one of the
10384 -- very few places that we place the flag in the middle of
10385 -- a token, right under the offending wide character. Not
10386 -- quite clear if this is right wrt wide character encoding
10387 -- sequences, but it's only an error message.
10389 Error_Msg
10390 ("literal out of range of type Standard.Character",
10391 Source_Ptr (Int (Loc) + J));
10392 return;
10393 end if;
10394 end loop;
10396 -- For the case of Standard.Wide_String, or any other type whose
10397 -- component type is Standard.Wide_Character, we must make sure that
10398 -- there are no wide characters in the string, i.e. that it is
10399 -- entirely composed of characters in range of type Wide_Character.
10401 -- If the string literal is the result of a static concatenation,
10402 -- the test has already been performed on the components, and need
10403 -- not be repeated.
10405 elsif R_Typ = Standard_Wide_Character
10406 and then Nkind (Original_Node (N)) /= N_Op_Concat
10407 then
10408 for J in 1 .. Strlen loop
10409 if not In_Wide_Character_Range (Get_String_Char (Str, J)) then
10411 -- If we are out of range, post error. This is one of the
10412 -- very few places that we place the flag in the middle of
10413 -- a token, right under the offending wide character.
10415 -- This is not quite right, because characters in general
10416 -- will take more than one character position ???
10418 Error_Msg
10419 ("literal out of range of type Standard.Wide_Character",
10420 Source_Ptr (Int (Loc) + J));
10421 return;
10422 end if;
10423 end loop;
10425 -- If the root type is not a standard character, then we will convert
10426 -- the string into an aggregate and will let the aggregate code do
10427 -- the checking. Standard Wide_Wide_Character is also OK here.
10429 else
10430 null;
10431 end if;
10433 -- See if the component type of the array corresponding to the string
10434 -- has compile time known bounds. If yes we can directly check
10435 -- whether the evaluation of the string will raise constraint error.
10436 -- Otherwise we need to transform the string literal into the
10437 -- corresponding character aggregate and let the aggregate code do
10438 -- the checking.
10440 if Is_Standard_Character_Type (R_Typ) then
10442 -- Check for the case of full range, where we are definitely OK
10444 if Component_Type (Typ) = Base_Type (Component_Type (Typ)) then
10445 return;
10446 end if;
10448 -- Here the range is not the complete base type range, so check
10450 declare
10451 Comp_Typ_Lo : constant Node_Id :=
10452 Type_Low_Bound (Component_Type (Typ));
10453 Comp_Typ_Hi : constant Node_Id :=
10454 Type_High_Bound (Component_Type (Typ));
10456 Char_Val : Uint;
10458 begin
10459 if Compile_Time_Known_Value (Comp_Typ_Lo)
10460 and then Compile_Time_Known_Value (Comp_Typ_Hi)
10461 then
10462 for J in 1 .. Strlen loop
10463 Char_Val := UI_From_Int (Int (Get_String_Char (Str, J)));
10465 if Char_Val < Expr_Value (Comp_Typ_Lo)
10466 or else Char_Val > Expr_Value (Comp_Typ_Hi)
10467 then
10468 Apply_Compile_Time_Constraint_Error
10469 (N, "character out of range??",
10470 CE_Range_Check_Failed,
10471 Loc => Source_Ptr (Int (Loc) + J));
10472 end if;
10473 end loop;
10475 return;
10476 end if;
10477 end;
10478 end if;
10479 end if;
10481 -- If we got here we meed to transform the string literal into the
10482 -- equivalent qualified positional array aggregate. This is rather
10483 -- heavy artillery for this situation, but it is hard work to avoid.
10485 declare
10486 Lits : constant List_Id := New_List;
10487 P : Source_Ptr := Loc + 1;
10488 C : Char_Code;
10490 begin
10491 -- Build the character literals, we give them source locations that
10492 -- correspond to the string positions, which is a bit tricky given
10493 -- the possible presence of wide character escape sequences.
10495 for J in 1 .. Strlen loop
10496 C := Get_String_Char (Str, J);
10497 Set_Character_Literal_Name (C);
10499 Append_To (Lits,
10500 Make_Character_Literal (P,
10501 Chars => Name_Find,
10502 Char_Literal_Value => UI_From_CC (C)));
10504 if In_Character_Range (C) then
10505 P := P + 1;
10507 -- Should we have a call to Skip_Wide here ???
10509 -- ??? else
10510 -- Skip_Wide (P);
10512 end if;
10513 end loop;
10515 Rewrite (N,
10516 Make_Qualified_Expression (Loc,
10517 Subtype_Mark => New_Occurrence_Of (Typ, Loc),
10518 Expression =>
10519 Make_Aggregate (Loc, Expressions => Lits)));
10521 Analyze_And_Resolve (N, Typ);
10522 end;
10523 end Resolve_String_Literal;
10525 -----------------------------
10526 -- Resolve_Type_Conversion --
10527 -----------------------------
10529 procedure Resolve_Type_Conversion (N : Node_Id; Typ : Entity_Id) is
10530 Conv_OK : constant Boolean := Conversion_OK (N);
10531 Operand : constant Node_Id := Expression (N);
10532 Operand_Typ : constant Entity_Id := Etype (Operand);
10533 Target_Typ : constant Entity_Id := Etype (N);
10534 Rop : Node_Id;
10535 Orig_N : Node_Id;
10536 Orig_T : Node_Id;
10538 Test_Redundant : Boolean := Warn_On_Redundant_Constructs;
10539 -- Set to False to suppress cases where we want to suppress the test
10540 -- for redundancy to avoid possible false positives on this warning.
10542 begin
10543 if not Conv_OK
10544 and then not Valid_Conversion (N, Target_Typ, Operand)
10545 then
10546 return;
10547 end if;
10549 -- If the Operand Etype is Universal_Fixed, then the conversion is
10550 -- never redundant. We need this check because by the time we have
10551 -- finished the rather complex transformation, the conversion looks
10552 -- redundant when it is not.
10554 if Operand_Typ = Universal_Fixed then
10555 Test_Redundant := False;
10557 -- If the operand is marked as Any_Fixed, then special processing is
10558 -- required. This is also a case where we suppress the test for a
10559 -- redundant conversion, since most certainly it is not redundant.
10561 elsif Operand_Typ = Any_Fixed then
10562 Test_Redundant := False;
10564 -- Mixed-mode operation involving a literal. Context must be a fixed
10565 -- type which is applied to the literal subsequently.
10567 if Is_Fixed_Point_Type (Typ) then
10568 Set_Etype (Operand, Universal_Real);
10570 elsif Is_Numeric_Type (Typ)
10571 and then Nkind_In (Operand, N_Op_Multiply, N_Op_Divide)
10572 and then (Etype (Right_Opnd (Operand)) = Universal_Real
10573 or else
10574 Etype (Left_Opnd (Operand)) = Universal_Real)
10575 then
10576 -- Return if expression is ambiguous
10578 if Unique_Fixed_Point_Type (N) = Any_Type then
10579 return;
10581 -- If nothing else, the available fixed type is Duration
10583 else
10584 Set_Etype (Operand, Standard_Duration);
10585 end if;
10587 -- Resolve the real operand with largest available precision
10589 if Etype (Right_Opnd (Operand)) = Universal_Real then
10590 Rop := New_Copy_Tree (Right_Opnd (Operand));
10591 else
10592 Rop := New_Copy_Tree (Left_Opnd (Operand));
10593 end if;
10595 Resolve (Rop, Universal_Real);
10597 -- If the operand is a literal (it could be a non-static and
10598 -- illegal exponentiation) check whether the use of Duration
10599 -- is potentially inaccurate.
10601 if Nkind (Rop) = N_Real_Literal
10602 and then Realval (Rop) /= Ureal_0
10603 and then abs (Realval (Rop)) < Delta_Value (Standard_Duration)
10604 then
10605 Error_Msg_N
10606 ("??universal real operand can only "
10607 & "be interpreted as Duration!", Rop);
10608 Error_Msg_N
10609 ("\??precision will be lost in the conversion!", Rop);
10610 end if;
10612 elsif Is_Numeric_Type (Typ)
10613 and then Nkind (Operand) in N_Op
10614 and then Unique_Fixed_Point_Type (N) /= Any_Type
10615 then
10616 Set_Etype (Operand, Standard_Duration);
10618 else
10619 Error_Msg_N ("invalid context for mixed mode operation", N);
10620 Set_Etype (Operand, Any_Type);
10621 return;
10622 end if;
10623 end if;
10625 Resolve (Operand);
10627 -- In SPARK, a type conversion between array types should be restricted
10628 -- to types which have matching static bounds.
10630 -- Protect call to Matching_Static_Array_Bounds to avoid costly
10631 -- operation if not needed.
10633 if Restriction_Check_Required (SPARK_05)
10634 and then Is_Array_Type (Target_Typ)
10635 and then Is_Array_Type (Operand_Typ)
10636 and then Operand_Typ /= Any_Composite -- or else Operand in error
10637 and then not Matching_Static_Array_Bounds (Target_Typ, Operand_Typ)
10638 then
10639 Check_SPARK_05_Restriction
10640 ("array types should have matching static bounds", N);
10641 end if;
10643 -- In formal mode, the operand of an ancestor type conversion must be an
10644 -- object (not an expression).
10646 if Is_Tagged_Type (Target_Typ)
10647 and then not Is_Class_Wide_Type (Target_Typ)
10648 and then Is_Tagged_Type (Operand_Typ)
10649 and then not Is_Class_Wide_Type (Operand_Typ)
10650 and then Is_Ancestor (Target_Typ, Operand_Typ)
10651 and then not Is_SPARK_05_Object_Reference (Operand)
10652 then
10653 Check_SPARK_05_Restriction ("object required", Operand);
10654 end if;
10656 Analyze_Dimension (N);
10658 -- Note: we do the Eval_Type_Conversion call before applying the
10659 -- required checks for a subtype conversion. This is important, since
10660 -- both are prepared under certain circumstances to change the type
10661 -- conversion to a constraint error node, but in the case of
10662 -- Eval_Type_Conversion this may reflect an illegality in the static
10663 -- case, and we would miss the illegality (getting only a warning
10664 -- message), if we applied the type conversion checks first.
10666 Eval_Type_Conversion (N);
10668 -- Even when evaluation is not possible, we may be able to simplify the
10669 -- conversion or its expression. This needs to be done before applying
10670 -- checks, since otherwise the checks may use the original expression
10671 -- and defeat the simplifications. This is specifically the case for
10672 -- elimination of the floating-point Truncation attribute in
10673 -- float-to-int conversions.
10675 Simplify_Type_Conversion (N);
10677 -- If after evaluation we still have a type conversion, then we may need
10678 -- to apply checks required for a subtype conversion.
10680 -- Skip these type conversion checks if universal fixed operands
10681 -- operands involved, since range checks are handled separately for
10682 -- these cases (in the appropriate Expand routines in unit Exp_Fixd).
10684 if Nkind (N) = N_Type_Conversion
10685 and then not Is_Generic_Type (Root_Type (Target_Typ))
10686 and then Target_Typ /= Universal_Fixed
10687 and then Operand_Typ /= Universal_Fixed
10688 then
10689 Apply_Type_Conversion_Checks (N);
10690 end if;
10692 -- Issue warning for conversion of simple object to its own type. We
10693 -- have to test the original nodes, since they may have been rewritten
10694 -- by various optimizations.
10696 Orig_N := Original_Node (N);
10698 -- Here we test for a redundant conversion if the warning mode is
10699 -- active (and was not locally reset), and we have a type conversion
10700 -- from source not appearing in a generic instance.
10702 if Test_Redundant
10703 and then Nkind (Orig_N) = N_Type_Conversion
10704 and then Comes_From_Source (Orig_N)
10705 and then not In_Instance
10706 then
10707 Orig_N := Original_Node (Expression (Orig_N));
10708 Orig_T := Target_Typ;
10710 -- If the node is part of a larger expression, the Target_Type
10711 -- may not be the original type of the node if the context is a
10712 -- condition. Recover original type to see if conversion is needed.
10714 if Is_Boolean_Type (Orig_T)
10715 and then Nkind (Parent (N)) in N_Op
10716 then
10717 Orig_T := Etype (Parent (N));
10718 end if;
10720 -- If we have an entity name, then give the warning if the entity
10721 -- is the right type, or if it is a loop parameter covered by the
10722 -- original type (that's needed because loop parameters have an
10723 -- odd subtype coming from the bounds).
10725 if (Is_Entity_Name (Orig_N)
10726 and then
10727 (Etype (Entity (Orig_N)) = Orig_T
10728 or else
10729 (Ekind (Entity (Orig_N)) = E_Loop_Parameter
10730 and then Covers (Orig_T, Etype (Entity (Orig_N))))))
10732 -- If not an entity, then type of expression must match
10734 or else Etype (Orig_N) = Orig_T
10735 then
10736 -- One more check, do not give warning if the analyzed conversion
10737 -- has an expression with non-static bounds, and the bounds of the
10738 -- target are static. This avoids junk warnings in cases where the
10739 -- conversion is necessary to establish staticness, for example in
10740 -- a case statement.
10742 if not Is_OK_Static_Subtype (Operand_Typ)
10743 and then Is_OK_Static_Subtype (Target_Typ)
10744 then
10745 null;
10747 -- Finally, if this type conversion occurs in a context requiring
10748 -- a prefix, and the expression is a qualified expression then the
10749 -- type conversion is not redundant, since a qualified expression
10750 -- is not a prefix, whereas a type conversion is. For example, "X
10751 -- := T'(Funx(...)).Y;" is illegal because a selected component
10752 -- requires a prefix, but a type conversion makes it legal: "X :=
10753 -- T(T'(Funx(...))).Y;"
10755 -- In Ada 2012, a qualified expression is a name, so this idiom is
10756 -- no longer needed, but we still suppress the warning because it
10757 -- seems unfriendly for warnings to pop up when you switch to the
10758 -- newer language version.
10760 elsif Nkind (Orig_N) = N_Qualified_Expression
10761 and then Nkind_In (Parent (N), N_Attribute_Reference,
10762 N_Indexed_Component,
10763 N_Selected_Component,
10764 N_Slice,
10765 N_Explicit_Dereference)
10766 then
10767 null;
10769 -- Never warn on conversion to Long_Long_Integer'Base since
10770 -- that is most likely an artifact of the extended overflow
10771 -- checking and comes from complex expanded code.
10773 elsif Orig_T = Base_Type (Standard_Long_Long_Integer) then
10774 null;
10776 -- Here we give the redundant conversion warning. If it is an
10777 -- entity, give the name of the entity in the message. If not,
10778 -- just mention the expression.
10780 -- Shoudn't we test Warn_On_Redundant_Constructs here ???
10782 else
10783 if Is_Entity_Name (Orig_N) then
10784 Error_Msg_Node_2 := Orig_T;
10785 Error_Msg_NE -- CODEFIX
10786 ("??redundant conversion, & is of type &!",
10787 N, Entity (Orig_N));
10788 else
10789 Error_Msg_NE
10790 ("??redundant conversion, expression is of type&!",
10791 N, Orig_T);
10792 end if;
10793 end if;
10794 end if;
10795 end if;
10797 -- Ada 2005 (AI-251): Handle class-wide interface type conversions.
10798 -- No need to perform any interface conversion if the type of the
10799 -- expression coincides with the target type.
10801 if Ada_Version >= Ada_2005
10802 and then Expander_Active
10803 and then Operand_Typ /= Target_Typ
10804 then
10805 declare
10806 Opnd : Entity_Id := Operand_Typ;
10807 Target : Entity_Id := Target_Typ;
10809 begin
10810 -- If the type of the operand is a limited view, use the non-
10811 -- limited view when available.
10813 if From_Limited_With (Opnd)
10814 and then Ekind (Opnd) in Incomplete_Kind
10815 and then Present (Non_Limited_View (Opnd))
10816 then
10817 Opnd := Non_Limited_View (Opnd);
10818 Set_Etype (Expression (N), Opnd);
10819 end if;
10821 if Is_Access_Type (Opnd) then
10822 Opnd := Designated_Type (Opnd);
10823 end if;
10825 if Is_Access_Type (Target_Typ) then
10826 Target := Designated_Type (Target);
10827 end if;
10829 if Opnd = Target then
10830 null;
10832 -- Conversion from interface type
10834 elsif Is_Interface (Opnd) then
10836 -- Ada 2005 (AI-217): Handle entities from limited views
10838 if From_Limited_With (Opnd) then
10839 Error_Msg_Qual_Level := 99;
10840 Error_Msg_NE -- CODEFIX
10841 ("missing WITH clause on package &", N,
10842 Cunit_Entity (Get_Source_Unit (Base_Type (Opnd))));
10843 Error_Msg_N
10844 ("type conversions require visibility of the full view",
10847 elsif From_Limited_With (Target)
10848 and then not
10849 (Is_Access_Type (Target_Typ)
10850 and then Present (Non_Limited_View (Etype (Target))))
10851 then
10852 Error_Msg_Qual_Level := 99;
10853 Error_Msg_NE -- CODEFIX
10854 ("missing WITH clause on package &", N,
10855 Cunit_Entity (Get_Source_Unit (Base_Type (Target))));
10856 Error_Msg_N
10857 ("type conversions require visibility of the full view",
10860 else
10861 Expand_Interface_Conversion (N);
10862 end if;
10864 -- Conversion to interface type
10866 elsif Is_Interface (Target) then
10868 -- Handle subtypes
10870 if Ekind_In (Opnd, E_Protected_Subtype, E_Task_Subtype) then
10871 Opnd := Etype (Opnd);
10872 end if;
10874 if Is_Class_Wide_Type (Opnd)
10875 or else Interface_Present_In_Ancestor
10876 (Typ => Opnd,
10877 Iface => Target)
10878 then
10879 Expand_Interface_Conversion (N);
10880 else
10881 Error_Msg_Name_1 := Chars (Etype (Target));
10882 Error_Msg_Name_2 := Chars (Opnd);
10883 Error_Msg_N
10884 ("wrong interface conversion (% is not a progenitor "
10885 & "of %)", N);
10886 end if;
10887 end if;
10888 end;
10889 end if;
10891 -- Ada 2012: if target type has predicates, the result requires a
10892 -- predicate check. If the context is a call to another predicate
10893 -- check we must prevent infinite recursion.
10895 if Has_Predicates (Target_Typ) then
10896 if Nkind (Parent (N)) = N_Function_Call
10897 and then Present (Name (Parent (N)))
10898 and then (Is_Predicate_Function (Entity (Name (Parent (N))))
10899 or else
10900 Is_Predicate_Function_M (Entity (Name (Parent (N)))))
10901 then
10902 null;
10904 else
10905 Apply_Predicate_Check (N, Target_Typ);
10906 end if;
10907 end if;
10909 -- If at this stage we have a real to integer conversion, make sure
10910 -- that the Do_Range_Check flag is set, because such conversions in
10911 -- general need a range check. We only need this if expansion is off
10912 -- or we are in GNATProve mode.
10914 if Nkind (N) = N_Type_Conversion
10915 and then (GNATprove_Mode or not Expander_Active)
10916 and then Is_Integer_Type (Target_Typ)
10917 and then Is_Real_Type (Operand_Typ)
10918 then
10919 Set_Do_Range_Check (Operand);
10920 end if;
10921 end Resolve_Type_Conversion;
10923 ----------------------
10924 -- Resolve_Unary_Op --
10925 ----------------------
10927 procedure Resolve_Unary_Op (N : Node_Id; Typ : Entity_Id) is
10928 B_Typ : constant Entity_Id := Base_Type (Typ);
10929 R : constant Node_Id := Right_Opnd (N);
10930 OK : Boolean;
10931 Lo : Uint;
10932 Hi : Uint;
10934 begin
10935 if Is_Modular_Integer_Type (Typ) and then Nkind (N) /= N_Op_Not then
10936 Error_Msg_Name_1 := Chars (Typ);
10937 Check_SPARK_05_Restriction
10938 ("unary operator not defined for modular type%", N);
10939 end if;
10941 -- Deal with intrinsic unary operators
10943 if Comes_From_Source (N)
10944 and then Ekind (Entity (N)) = E_Function
10945 and then Is_Imported (Entity (N))
10946 and then Is_Intrinsic_Subprogram (Entity (N))
10947 then
10948 Resolve_Intrinsic_Unary_Operator (N, Typ);
10949 return;
10950 end if;
10952 -- Deal with universal cases
10954 if Etype (R) = Universal_Integer
10955 or else
10956 Etype (R) = Universal_Real
10957 then
10958 Check_For_Visible_Operator (N, B_Typ);
10959 end if;
10961 Set_Etype (N, B_Typ);
10962 Resolve (R, B_Typ);
10964 -- Generate warning for expressions like abs (x mod 2)
10966 if Warn_On_Redundant_Constructs
10967 and then Nkind (N) = N_Op_Abs
10968 then
10969 Determine_Range (Right_Opnd (N), OK, Lo, Hi);
10971 if OK and then Hi >= Lo and then Lo >= 0 then
10972 Error_Msg_N -- CODEFIX
10973 ("?r?abs applied to known non-negative value has no effect", N);
10974 end if;
10975 end if;
10977 -- Deal with reference generation
10979 Check_Unset_Reference (R);
10980 Generate_Operator_Reference (N, B_Typ);
10981 Analyze_Dimension (N);
10982 Eval_Unary_Op (N);
10984 -- Set overflow checking bit. Much cleverer code needed here eventually
10985 -- and perhaps the Resolve routines should be separated for the various
10986 -- arithmetic operations, since they will need different processing ???
10988 if Nkind (N) in N_Op then
10989 if not Overflow_Checks_Suppressed (Etype (N)) then
10990 Enable_Overflow_Check (N);
10991 end if;
10992 end if;
10994 -- Generate warning for expressions like -5 mod 3 for integers. No need
10995 -- to worry in the floating-point case, since parens do not affect the
10996 -- result so there is no point in giving in a warning.
10998 declare
10999 Norig : constant Node_Id := Original_Node (N);
11000 Rorig : Node_Id;
11001 Val : Uint;
11002 HB : Uint;
11003 LB : Uint;
11004 Lval : Uint;
11005 Opnd : Node_Id;
11007 begin
11008 if Warn_On_Questionable_Missing_Parens
11009 and then Comes_From_Source (Norig)
11010 and then Is_Integer_Type (Typ)
11011 and then Nkind (Norig) = N_Op_Minus
11012 then
11013 Rorig := Original_Node (Right_Opnd (Norig));
11015 -- We are looking for cases where the right operand is not
11016 -- parenthesized, and is a binary operator, multiply, divide, or
11017 -- mod. These are the cases where the grouping can affect results.
11019 if Paren_Count (Rorig) = 0
11020 and then Nkind_In (Rorig, N_Op_Mod, N_Op_Multiply, N_Op_Divide)
11021 then
11022 -- For mod, we always give the warning, since the value is
11023 -- affected by the parenthesization (e.g. (-5) mod 315 /=
11024 -- -(5 mod 315)). But for the other cases, the only concern is
11025 -- overflow, e.g. for the case of 8 big signed (-(2 * 64)
11026 -- overflows, but (-2) * 64 does not). So we try to give the
11027 -- message only when overflow is possible.
11029 if Nkind (Rorig) /= N_Op_Mod
11030 and then Compile_Time_Known_Value (R)
11031 then
11032 Val := Expr_Value (R);
11034 if Compile_Time_Known_Value (Type_High_Bound (Typ)) then
11035 HB := Expr_Value (Type_High_Bound (Typ));
11036 else
11037 HB := Expr_Value (Type_High_Bound (Base_Type (Typ)));
11038 end if;
11040 if Compile_Time_Known_Value (Type_Low_Bound (Typ)) then
11041 LB := Expr_Value (Type_Low_Bound (Typ));
11042 else
11043 LB := Expr_Value (Type_Low_Bound (Base_Type (Typ)));
11044 end if;
11046 -- Note that the test below is deliberately excluding the
11047 -- largest negative number, since that is a potentially
11048 -- troublesome case (e.g. -2 * x, where the result is the
11049 -- largest negative integer has an overflow with 2 * x).
11051 if Val > LB and then Val <= HB then
11052 return;
11053 end if;
11054 end if;
11056 -- For the multiplication case, the only case we have to worry
11057 -- about is when (-a)*b is exactly the largest negative number
11058 -- so that -(a*b) can cause overflow. This can only happen if
11059 -- a is a power of 2, and more generally if any operand is a
11060 -- constant that is not a power of 2, then the parentheses
11061 -- cannot affect whether overflow occurs. We only bother to
11062 -- test the left most operand
11064 -- Loop looking at left operands for one that has known value
11066 Opnd := Rorig;
11067 Opnd_Loop : while Nkind (Opnd) = N_Op_Multiply loop
11068 if Compile_Time_Known_Value (Left_Opnd (Opnd)) then
11069 Lval := UI_Abs (Expr_Value (Left_Opnd (Opnd)));
11071 -- Operand value of 0 or 1 skips warning
11073 if Lval <= 1 then
11074 return;
11076 -- Otherwise check power of 2, if power of 2, warn, if
11077 -- anything else, skip warning.
11079 else
11080 while Lval /= 2 loop
11081 if Lval mod 2 = 1 then
11082 return;
11083 else
11084 Lval := Lval / 2;
11085 end if;
11086 end loop;
11088 exit Opnd_Loop;
11089 end if;
11090 end if;
11092 -- Keep looking at left operands
11094 Opnd := Left_Opnd (Opnd);
11095 end loop Opnd_Loop;
11097 -- For rem or "/" we can only have a problematic situation
11098 -- if the divisor has a value of minus one or one. Otherwise
11099 -- overflow is impossible (divisor > 1) or we have a case of
11100 -- division by zero in any case.
11102 if Nkind_In (Rorig, N_Op_Divide, N_Op_Rem)
11103 and then Compile_Time_Known_Value (Right_Opnd (Rorig))
11104 and then UI_Abs (Expr_Value (Right_Opnd (Rorig))) /= 1
11105 then
11106 return;
11107 end if;
11109 -- If we fall through warning should be issued
11111 -- Shouldn't we test Warn_On_Questionable_Missing_Parens ???
11113 Error_Msg_N
11114 ("??unary minus expression should be parenthesized here!", N);
11115 end if;
11116 end if;
11117 end;
11118 end Resolve_Unary_Op;
11120 ----------------------------------
11121 -- Resolve_Unchecked_Expression --
11122 ----------------------------------
11124 procedure Resolve_Unchecked_Expression
11125 (N : Node_Id;
11126 Typ : Entity_Id)
11128 begin
11129 Resolve (Expression (N), Typ, Suppress => All_Checks);
11130 Set_Etype (N, Typ);
11131 end Resolve_Unchecked_Expression;
11133 ---------------------------------------
11134 -- Resolve_Unchecked_Type_Conversion --
11135 ---------------------------------------
11137 procedure Resolve_Unchecked_Type_Conversion
11138 (N : Node_Id;
11139 Typ : Entity_Id)
11141 pragma Warnings (Off, Typ);
11143 Operand : constant Node_Id := Expression (N);
11144 Opnd_Type : constant Entity_Id := Etype (Operand);
11146 begin
11147 -- Resolve operand using its own type
11149 Resolve (Operand, Opnd_Type);
11151 -- In an inlined context, the unchecked conversion may be applied
11152 -- to a literal, in which case its type is the type of the context.
11153 -- (In other contexts conversions cannot apply to literals).
11155 if In_Inlined_Body
11156 and then (Opnd_Type = Any_Character or else
11157 Opnd_Type = Any_Integer or else
11158 Opnd_Type = Any_Real)
11159 then
11160 Set_Etype (Operand, Typ);
11161 end if;
11163 Analyze_Dimension (N);
11164 Eval_Unchecked_Conversion (N);
11165 end Resolve_Unchecked_Type_Conversion;
11167 ------------------------------
11168 -- Rewrite_Operator_As_Call --
11169 ------------------------------
11171 procedure Rewrite_Operator_As_Call (N : Node_Id; Nam : Entity_Id) is
11172 Loc : constant Source_Ptr := Sloc (N);
11173 Actuals : constant List_Id := New_List;
11174 New_N : Node_Id;
11176 begin
11177 if Nkind (N) in N_Binary_Op then
11178 Append (Left_Opnd (N), Actuals);
11179 end if;
11181 Append (Right_Opnd (N), Actuals);
11183 New_N :=
11184 Make_Function_Call (Sloc => Loc,
11185 Name => New_Occurrence_Of (Nam, Loc),
11186 Parameter_Associations => Actuals);
11188 Preserve_Comes_From_Source (New_N, N);
11189 Preserve_Comes_From_Source (Name (New_N), N);
11190 Rewrite (N, New_N);
11191 Set_Etype (N, Etype (Nam));
11192 end Rewrite_Operator_As_Call;
11194 ------------------------------
11195 -- Rewrite_Renamed_Operator --
11196 ------------------------------
11198 procedure Rewrite_Renamed_Operator
11199 (N : Node_Id;
11200 Op : Entity_Id;
11201 Typ : Entity_Id)
11203 Nam : constant Name_Id := Chars (Op);
11204 Is_Binary : constant Boolean := Nkind (N) in N_Binary_Op;
11205 Op_Node : Node_Id;
11207 begin
11208 -- Do not perform this transformation within a pre/postcondition,
11209 -- because the expression will be re-analyzed, and the transformation
11210 -- might affect the visibility of the operator, e.g. in an instance.
11212 if In_Assertion_Expr > 0 then
11213 return;
11214 end if;
11216 -- Rewrite the operator node using the real operator, not its renaming.
11217 -- Exclude user-defined intrinsic operations of the same name, which are
11218 -- treated separately and rewritten as calls.
11220 if Ekind (Op) /= E_Function or else Chars (N) /= Nam then
11221 Op_Node := New_Node (Operator_Kind (Nam, Is_Binary), Sloc (N));
11222 Set_Chars (Op_Node, Nam);
11223 Set_Etype (Op_Node, Etype (N));
11224 Set_Entity (Op_Node, Op);
11225 Set_Right_Opnd (Op_Node, Right_Opnd (N));
11227 -- Indicate that both the original entity and its renaming are
11228 -- referenced at this point.
11230 Generate_Reference (Entity (N), N);
11231 Generate_Reference (Op, N);
11233 if Is_Binary then
11234 Set_Left_Opnd (Op_Node, Left_Opnd (N));
11235 end if;
11237 Rewrite (N, Op_Node);
11239 -- If the context type is private, add the appropriate conversions so
11240 -- that the operator is applied to the full view. This is done in the
11241 -- routines that resolve intrinsic operators.
11243 if Is_Intrinsic_Subprogram (Op)
11244 and then Is_Private_Type (Typ)
11245 then
11246 case Nkind (N) is
11247 when N_Op_Add | N_Op_Subtract | N_Op_Multiply | N_Op_Divide |
11248 N_Op_Expon | N_Op_Mod | N_Op_Rem =>
11249 Resolve_Intrinsic_Operator (N, Typ);
11251 when N_Op_Plus | N_Op_Minus | N_Op_Abs =>
11252 Resolve_Intrinsic_Unary_Operator (N, Typ);
11254 when others =>
11255 Resolve (N, Typ);
11256 end case;
11257 end if;
11259 elsif Ekind (Op) = E_Function and then Is_Intrinsic_Subprogram (Op) then
11261 -- Operator renames a user-defined operator of the same name. Use the
11262 -- original operator in the node, which is the one Gigi knows about.
11264 Set_Entity (N, Op);
11265 Set_Is_Overloaded (N, False);
11266 end if;
11267 end Rewrite_Renamed_Operator;
11269 -----------------------
11270 -- Set_Slice_Subtype --
11271 -----------------------
11273 -- Build an implicit subtype declaration to represent the type delivered by
11274 -- the slice. This is an abbreviated version of an array subtype. We define
11275 -- an index subtype for the slice, using either the subtype name or the
11276 -- discrete range of the slice. To be consistent with index usage elsewhere
11277 -- we create a list header to hold the single index. This list is not
11278 -- otherwise attached to the syntax tree.
11280 procedure Set_Slice_Subtype (N : Node_Id) is
11281 Loc : constant Source_Ptr := Sloc (N);
11282 Index_List : constant List_Id := New_List;
11283 Index : Node_Id;
11284 Index_Subtype : Entity_Id;
11285 Index_Type : Entity_Id;
11286 Slice_Subtype : Entity_Id;
11287 Drange : constant Node_Id := Discrete_Range (N);
11289 begin
11290 Index_Type := Base_Type (Etype (Drange));
11292 if Is_Entity_Name (Drange) then
11293 Index_Subtype := Entity (Drange);
11295 else
11296 -- We force the evaluation of a range. This is definitely needed in
11297 -- the renamed case, and seems safer to do unconditionally. Note in
11298 -- any case that since we will create and insert an Itype referring
11299 -- to this range, we must make sure any side effect removal actions
11300 -- are inserted before the Itype definition.
11302 if Nkind (Drange) = N_Range then
11303 Force_Evaluation (Low_Bound (Drange));
11304 Force_Evaluation (High_Bound (Drange));
11306 -- If the discrete range is given by a subtype indication, the
11307 -- type of the slice is the base of the subtype mark.
11309 elsif Nkind (Drange) = N_Subtype_Indication then
11310 declare
11311 R : constant Node_Id := Range_Expression (Constraint (Drange));
11312 begin
11313 Index_Type := Base_Type (Entity (Subtype_Mark (Drange)));
11314 Force_Evaluation (Low_Bound (R));
11315 Force_Evaluation (High_Bound (R));
11316 end;
11317 end if;
11319 Index_Subtype := Create_Itype (Subtype_Kind (Ekind (Index_Type)), N);
11321 -- Take a new copy of Drange (where bounds have been rewritten to
11322 -- reference side-effect-free names). Using a separate tree ensures
11323 -- that further expansion (e.g. while rewriting a slice assignment
11324 -- into a FOR loop) does not attempt to remove side effects on the
11325 -- bounds again (which would cause the bounds in the index subtype
11326 -- definition to refer to temporaries before they are defined) (the
11327 -- reason is that some names are considered side effect free here
11328 -- for the subtype, but not in the context of a loop iteration
11329 -- scheme).
11331 Set_Scalar_Range (Index_Subtype, New_Copy_Tree (Drange));
11332 Set_Parent (Scalar_Range (Index_Subtype), Index_Subtype);
11333 Set_Etype (Index_Subtype, Index_Type);
11334 Set_Size_Info (Index_Subtype, Index_Type);
11335 Set_RM_Size (Index_Subtype, RM_Size (Index_Type));
11336 end if;
11338 Slice_Subtype := Create_Itype (E_Array_Subtype, N);
11340 Index := New_Occurrence_Of (Index_Subtype, Loc);
11341 Set_Etype (Index, Index_Subtype);
11342 Append (Index, Index_List);
11344 Set_First_Index (Slice_Subtype, Index);
11345 Set_Etype (Slice_Subtype, Base_Type (Etype (N)));
11346 Set_Is_Constrained (Slice_Subtype, True);
11348 Check_Compile_Time_Size (Slice_Subtype);
11350 -- The Etype of the existing Slice node is reset to this slice subtype.
11351 -- Its bounds are obtained from its first index.
11353 Set_Etype (N, Slice_Subtype);
11355 -- For packed slice subtypes, freeze immediately (except in the case of
11356 -- being in a "spec expression" where we never freeze when we first see
11357 -- the expression).
11359 if Is_Packed (Slice_Subtype) and not In_Spec_Expression then
11360 Freeze_Itype (Slice_Subtype, N);
11362 -- For all other cases insert an itype reference in the slice's actions
11363 -- so that the itype is frozen at the proper place in the tree (i.e. at
11364 -- the point where actions for the slice are analyzed). Note that this
11365 -- is different from freezing the itype immediately, which might be
11366 -- premature (e.g. if the slice is within a transient scope). This needs
11367 -- to be done only if expansion is enabled.
11369 elsif Expander_Active then
11370 Ensure_Defined (Typ => Slice_Subtype, N => N);
11371 end if;
11372 end Set_Slice_Subtype;
11374 --------------------------------
11375 -- Set_String_Literal_Subtype --
11376 --------------------------------
11378 procedure Set_String_Literal_Subtype (N : Node_Id; Typ : Entity_Id) is
11379 Loc : constant Source_Ptr := Sloc (N);
11380 Low_Bound : constant Node_Id :=
11381 Type_Low_Bound (Etype (First_Index (Typ)));
11382 Subtype_Id : Entity_Id;
11384 begin
11385 if Nkind (N) /= N_String_Literal then
11386 return;
11387 end if;
11389 Subtype_Id := Create_Itype (E_String_Literal_Subtype, N);
11390 Set_String_Literal_Length (Subtype_Id, UI_From_Int
11391 (String_Length (Strval (N))));
11392 Set_Etype (Subtype_Id, Base_Type (Typ));
11393 Set_Is_Constrained (Subtype_Id);
11394 Set_Etype (N, Subtype_Id);
11396 -- The low bound is set from the low bound of the corresponding index
11397 -- type. Note that we do not store the high bound in the string literal
11398 -- subtype, but it can be deduced if necessary from the length and the
11399 -- low bound.
11401 if Is_OK_Static_Expression (Low_Bound) then
11402 Set_String_Literal_Low_Bound (Subtype_Id, Low_Bound);
11404 -- If the lower bound is not static we create a range for the string
11405 -- literal, using the index type and the known length of the literal.
11406 -- The index type is not necessarily Positive, so the upper bound is
11407 -- computed as T'Val (T'Pos (Low_Bound) + L - 1).
11409 else
11410 declare
11411 Index_List : constant List_Id := New_List;
11412 Index_Type : constant Entity_Id := Etype (First_Index (Typ));
11413 High_Bound : constant Node_Id :=
11414 Make_Attribute_Reference (Loc,
11415 Attribute_Name => Name_Val,
11416 Prefix =>
11417 New_Occurrence_Of (Index_Type, Loc),
11418 Expressions => New_List (
11419 Make_Op_Add (Loc,
11420 Left_Opnd =>
11421 Make_Attribute_Reference (Loc,
11422 Attribute_Name => Name_Pos,
11423 Prefix =>
11424 New_Occurrence_Of (Index_Type, Loc),
11425 Expressions =>
11426 New_List (New_Copy_Tree (Low_Bound))),
11427 Right_Opnd =>
11428 Make_Integer_Literal (Loc,
11429 String_Length (Strval (N)) - 1))));
11431 Array_Subtype : Entity_Id;
11432 Drange : Node_Id;
11433 Index : Node_Id;
11434 Index_Subtype : Entity_Id;
11436 begin
11437 if Is_Integer_Type (Index_Type) then
11438 Set_String_Literal_Low_Bound
11439 (Subtype_Id, Make_Integer_Literal (Loc, 1));
11441 else
11442 -- If the index type is an enumeration type, build bounds
11443 -- expression with attributes.
11445 Set_String_Literal_Low_Bound
11446 (Subtype_Id,
11447 Make_Attribute_Reference (Loc,
11448 Attribute_Name => Name_First,
11449 Prefix =>
11450 New_Occurrence_Of (Base_Type (Index_Type), Loc)));
11451 Set_Etype (String_Literal_Low_Bound (Subtype_Id), Index_Type);
11452 end if;
11454 Analyze_And_Resolve (String_Literal_Low_Bound (Subtype_Id));
11456 -- Build bona fide subtype for the string, and wrap it in an
11457 -- unchecked conversion, because the backend expects the
11458 -- String_Literal_Subtype to have a static lower bound.
11460 Index_Subtype :=
11461 Create_Itype (Subtype_Kind (Ekind (Index_Type)), N);
11462 Drange := Make_Range (Loc, New_Copy_Tree (Low_Bound), High_Bound);
11463 Set_Scalar_Range (Index_Subtype, Drange);
11464 Set_Parent (Drange, N);
11465 Analyze_And_Resolve (Drange, Index_Type);
11467 -- In the context, the Index_Type may already have a constraint,
11468 -- so use common base type on string subtype. The base type may
11469 -- be used when generating attributes of the string, for example
11470 -- in the context of a slice assignment.
11472 Set_Etype (Index_Subtype, Base_Type (Index_Type));
11473 Set_Size_Info (Index_Subtype, Index_Type);
11474 Set_RM_Size (Index_Subtype, RM_Size (Index_Type));
11476 Array_Subtype := Create_Itype (E_Array_Subtype, N);
11478 Index := New_Occurrence_Of (Index_Subtype, Loc);
11479 Set_Etype (Index, Index_Subtype);
11480 Append (Index, Index_List);
11482 Set_First_Index (Array_Subtype, Index);
11483 Set_Etype (Array_Subtype, Base_Type (Typ));
11484 Set_Is_Constrained (Array_Subtype, True);
11486 Rewrite (N,
11487 Make_Unchecked_Type_Conversion (Loc,
11488 Subtype_Mark => New_Occurrence_Of (Array_Subtype, Loc),
11489 Expression => Relocate_Node (N)));
11490 Set_Etype (N, Array_Subtype);
11491 end;
11492 end if;
11493 end Set_String_Literal_Subtype;
11495 ------------------------------
11496 -- Simplify_Type_Conversion --
11497 ------------------------------
11499 procedure Simplify_Type_Conversion (N : Node_Id) is
11500 begin
11501 if Nkind (N) = N_Type_Conversion then
11502 declare
11503 Operand : constant Node_Id := Expression (N);
11504 Target_Typ : constant Entity_Id := Etype (N);
11505 Opnd_Typ : constant Entity_Id := Etype (Operand);
11507 begin
11508 -- Special processing if the conversion is the expression of a
11509 -- Rounding or Truncation attribute reference. In this case we
11510 -- replace:
11512 -- ityp (ftyp'Rounding (x)) or ityp (ftyp'Truncation (x))
11514 -- by
11516 -- ityp (x)
11518 -- with the Float_Truncate flag set to False or True respectively,
11519 -- which is more efficient.
11521 if Is_Floating_Point_Type (Opnd_Typ)
11522 and then
11523 (Is_Integer_Type (Target_Typ)
11524 or else (Is_Fixed_Point_Type (Target_Typ)
11525 and then Conversion_OK (N)))
11526 and then Nkind (Operand) = N_Attribute_Reference
11527 and then Nam_In (Attribute_Name (Operand), Name_Rounding,
11528 Name_Truncation)
11529 then
11530 declare
11531 Truncate : constant Boolean :=
11532 Attribute_Name (Operand) = Name_Truncation;
11533 begin
11534 Rewrite (Operand,
11535 Relocate_Node (First (Expressions (Operand))));
11536 Set_Float_Truncate (N, Truncate);
11537 end;
11538 end if;
11539 end;
11540 end if;
11541 end Simplify_Type_Conversion;
11543 -----------------------------
11544 -- Unique_Fixed_Point_Type --
11545 -----------------------------
11547 function Unique_Fixed_Point_Type (N : Node_Id) return Entity_Id is
11548 T1 : Entity_Id := Empty;
11549 T2 : Entity_Id;
11550 Item : Node_Id;
11551 Scop : Entity_Id;
11553 procedure Fixed_Point_Error;
11554 -- Give error messages for true ambiguity. Messages are posted on node
11555 -- N, and entities T1, T2 are the possible interpretations.
11557 -----------------------
11558 -- Fixed_Point_Error --
11559 -----------------------
11561 procedure Fixed_Point_Error is
11562 begin
11563 Error_Msg_N ("ambiguous universal_fixed_expression", N);
11564 Error_Msg_NE ("\\possible interpretation as}", N, T1);
11565 Error_Msg_NE ("\\possible interpretation as}", N, T2);
11566 end Fixed_Point_Error;
11568 -- Start of processing for Unique_Fixed_Point_Type
11570 begin
11571 -- The operations on Duration are visible, so Duration is always a
11572 -- possible interpretation.
11574 T1 := Standard_Duration;
11576 -- Look for fixed-point types in enclosing scopes
11578 Scop := Current_Scope;
11579 while Scop /= Standard_Standard loop
11580 T2 := First_Entity (Scop);
11581 while Present (T2) loop
11582 if Is_Fixed_Point_Type (T2)
11583 and then Current_Entity (T2) = T2
11584 and then Scope (Base_Type (T2)) = Scop
11585 then
11586 if Present (T1) then
11587 Fixed_Point_Error;
11588 return Any_Type;
11589 else
11590 T1 := T2;
11591 end if;
11592 end if;
11594 Next_Entity (T2);
11595 end loop;
11597 Scop := Scope (Scop);
11598 end loop;
11600 -- Look for visible fixed type declarations in the context
11602 Item := First (Context_Items (Cunit (Current_Sem_Unit)));
11603 while Present (Item) loop
11604 if Nkind (Item) = N_With_Clause then
11605 Scop := Entity (Name (Item));
11606 T2 := First_Entity (Scop);
11607 while Present (T2) loop
11608 if Is_Fixed_Point_Type (T2)
11609 and then Scope (Base_Type (T2)) = Scop
11610 and then (Is_Potentially_Use_Visible (T2) or else In_Use (T2))
11611 then
11612 if Present (T1) then
11613 Fixed_Point_Error;
11614 return Any_Type;
11615 else
11616 T1 := T2;
11617 end if;
11618 end if;
11620 Next_Entity (T2);
11621 end loop;
11622 end if;
11624 Next (Item);
11625 end loop;
11627 if Nkind (N) = N_Real_Literal then
11628 Error_Msg_NE
11629 ("??real literal interpreted as }!", N, T1);
11630 else
11631 Error_Msg_NE
11632 ("??universal_fixed expression interpreted as }!", N, T1);
11633 end if;
11635 return T1;
11636 end Unique_Fixed_Point_Type;
11638 ----------------------
11639 -- Valid_Conversion --
11640 ----------------------
11642 function Valid_Conversion
11643 (N : Node_Id;
11644 Target : Entity_Id;
11645 Operand : Node_Id;
11646 Report_Errs : Boolean := True) return Boolean
11648 Target_Type : constant Entity_Id := Base_Type (Target);
11649 Opnd_Type : Entity_Id := Etype (Operand);
11650 Inc_Ancestor : Entity_Id;
11652 function Conversion_Check
11653 (Valid : Boolean;
11654 Msg : String) return Boolean;
11655 -- Little routine to post Msg if Valid is False, returns Valid value
11657 procedure Conversion_Error_N (Msg : String; N : Node_Or_Entity_Id);
11658 -- If Report_Errs, then calls Errout.Error_Msg_N with its arguments
11660 procedure Conversion_Error_NE
11661 (Msg : String;
11662 N : Node_Or_Entity_Id;
11663 E : Node_Or_Entity_Id);
11664 -- If Report_Errs, then calls Errout.Error_Msg_NE with its arguments
11666 function Valid_Tagged_Conversion
11667 (Target_Type : Entity_Id;
11668 Opnd_Type : Entity_Id) return Boolean;
11669 -- Specifically test for validity of tagged conversions
11671 function Valid_Array_Conversion return Boolean;
11672 -- Check index and component conformance, and accessibility levels if
11673 -- the component types are anonymous access types (Ada 2005).
11675 ----------------------
11676 -- Conversion_Check --
11677 ----------------------
11679 function Conversion_Check
11680 (Valid : Boolean;
11681 Msg : String) return Boolean
11683 begin
11684 if not Valid
11686 -- A generic unit has already been analyzed and we have verified
11687 -- that a particular conversion is OK in that context. Since the
11688 -- instance is reanalyzed without relying on the relationships
11689 -- established during the analysis of the generic, it is possible
11690 -- to end up with inconsistent views of private types. Do not emit
11691 -- the error message in such cases. The rest of the machinery in
11692 -- Valid_Conversion still ensures the proper compatibility of
11693 -- target and operand types.
11695 and then not In_Instance
11696 then
11697 Conversion_Error_N (Msg, Operand);
11698 end if;
11700 return Valid;
11701 end Conversion_Check;
11703 ------------------------
11704 -- Conversion_Error_N --
11705 ------------------------
11707 procedure Conversion_Error_N (Msg : String; N : Node_Or_Entity_Id) is
11708 begin
11709 if Report_Errs then
11710 Error_Msg_N (Msg, N);
11711 end if;
11712 end Conversion_Error_N;
11714 -------------------------
11715 -- Conversion_Error_NE --
11716 -------------------------
11718 procedure Conversion_Error_NE
11719 (Msg : String;
11720 N : Node_Or_Entity_Id;
11721 E : Node_Or_Entity_Id)
11723 begin
11724 if Report_Errs then
11725 Error_Msg_NE (Msg, N, E);
11726 end if;
11727 end Conversion_Error_NE;
11729 ----------------------------
11730 -- Valid_Array_Conversion --
11731 ----------------------------
11733 function Valid_Array_Conversion return Boolean
11735 Opnd_Comp_Type : constant Entity_Id := Component_Type (Opnd_Type);
11736 Opnd_Comp_Base : constant Entity_Id := Base_Type (Opnd_Comp_Type);
11738 Opnd_Index : Node_Id;
11739 Opnd_Index_Type : Entity_Id;
11741 Target_Comp_Type : constant Entity_Id :=
11742 Component_Type (Target_Type);
11743 Target_Comp_Base : constant Entity_Id :=
11744 Base_Type (Target_Comp_Type);
11746 Target_Index : Node_Id;
11747 Target_Index_Type : Entity_Id;
11749 begin
11750 -- Error if wrong number of dimensions
11753 Number_Dimensions (Target_Type) /= Number_Dimensions (Opnd_Type)
11754 then
11755 Conversion_Error_N
11756 ("incompatible number of dimensions for conversion", Operand);
11757 return False;
11759 -- Number of dimensions matches
11761 else
11762 -- Loop through indexes of the two arrays
11764 Target_Index := First_Index (Target_Type);
11765 Opnd_Index := First_Index (Opnd_Type);
11766 while Present (Target_Index) and then Present (Opnd_Index) loop
11767 Target_Index_Type := Etype (Target_Index);
11768 Opnd_Index_Type := Etype (Opnd_Index);
11770 -- Error if index types are incompatible
11772 if not (Is_Integer_Type (Target_Index_Type)
11773 and then Is_Integer_Type (Opnd_Index_Type))
11774 and then (Root_Type (Target_Index_Type)
11775 /= Root_Type (Opnd_Index_Type))
11776 then
11777 Conversion_Error_N
11778 ("incompatible index types for array conversion",
11779 Operand);
11780 return False;
11781 end if;
11783 Next_Index (Target_Index);
11784 Next_Index (Opnd_Index);
11785 end loop;
11787 -- If component types have same base type, all set
11789 if Target_Comp_Base = Opnd_Comp_Base then
11790 null;
11792 -- Here if base types of components are not the same. The only
11793 -- time this is allowed is if we have anonymous access types.
11795 -- The conversion of arrays of anonymous access types can lead
11796 -- to dangling pointers. AI-392 formalizes the accessibility
11797 -- checks that must be applied to such conversions to prevent
11798 -- out-of-scope references.
11800 elsif Ekind_In
11801 (Target_Comp_Base, E_Anonymous_Access_Type,
11802 E_Anonymous_Access_Subprogram_Type)
11803 and then Ekind (Opnd_Comp_Base) = Ekind (Target_Comp_Base)
11804 and then
11805 Subtypes_Statically_Match (Target_Comp_Type, Opnd_Comp_Type)
11806 then
11807 if Type_Access_Level (Target_Type) <
11808 Deepest_Type_Access_Level (Opnd_Type)
11809 then
11810 if In_Instance_Body then
11811 Error_Msg_Warn := SPARK_Mode /= On;
11812 Conversion_Error_N
11813 ("source array type has deeper accessibility "
11814 & "level than target<<", Operand);
11815 Conversion_Error_N ("\Program_Error [<<", Operand);
11816 Rewrite (N,
11817 Make_Raise_Program_Error (Sloc (N),
11818 Reason => PE_Accessibility_Check_Failed));
11819 Set_Etype (N, Target_Type);
11820 return False;
11822 -- Conversion not allowed because of accessibility levels
11824 else
11825 Conversion_Error_N
11826 ("source array type has deeper accessibility "
11827 & "level than target", Operand);
11828 return False;
11829 end if;
11831 else
11832 null;
11833 end if;
11835 -- All other cases where component base types do not match
11837 else
11838 Conversion_Error_N
11839 ("incompatible component types for array conversion",
11840 Operand);
11841 return False;
11842 end if;
11844 -- Check that component subtypes statically match. For numeric
11845 -- types this means that both must be either constrained or
11846 -- unconstrained. For enumeration types the bounds must match.
11847 -- All of this is checked in Subtypes_Statically_Match.
11849 if not Subtypes_Statically_Match
11850 (Target_Comp_Type, Opnd_Comp_Type)
11851 then
11852 Conversion_Error_N
11853 ("component subtypes must statically match", Operand);
11854 return False;
11855 end if;
11856 end if;
11858 return True;
11859 end Valid_Array_Conversion;
11861 -----------------------------
11862 -- Valid_Tagged_Conversion --
11863 -----------------------------
11865 function Valid_Tagged_Conversion
11866 (Target_Type : Entity_Id;
11867 Opnd_Type : Entity_Id) return Boolean
11869 begin
11870 -- Upward conversions are allowed (RM 4.6(22))
11872 if Covers (Target_Type, Opnd_Type)
11873 or else Is_Ancestor (Target_Type, Opnd_Type)
11874 then
11875 return True;
11877 -- Downward conversion are allowed if the operand is class-wide
11878 -- (RM 4.6(23)).
11880 elsif Is_Class_Wide_Type (Opnd_Type)
11881 and then Covers (Opnd_Type, Target_Type)
11882 then
11883 return True;
11885 elsif Covers (Opnd_Type, Target_Type)
11886 or else Is_Ancestor (Opnd_Type, Target_Type)
11887 then
11888 return
11889 Conversion_Check (False,
11890 "downward conversion of tagged objects not allowed");
11892 -- Ada 2005 (AI-251): The conversion to/from interface types is
11893 -- always valid
11895 elsif Is_Interface (Target_Type) or else Is_Interface (Opnd_Type) then
11896 return True;
11898 -- If the operand is a class-wide type obtained through a limited_
11899 -- with clause, and the context includes the non-limited view, use
11900 -- it to determine whether the conversion is legal.
11902 elsif Is_Class_Wide_Type (Opnd_Type)
11903 and then From_Limited_With (Opnd_Type)
11904 and then Present (Non_Limited_View (Etype (Opnd_Type)))
11905 and then Is_Interface (Non_Limited_View (Etype (Opnd_Type)))
11906 then
11907 return True;
11909 elsif Is_Access_Type (Opnd_Type)
11910 and then Is_Interface (Directly_Designated_Type (Opnd_Type))
11911 then
11912 return True;
11914 else
11915 Conversion_Error_NE
11916 ("invalid tagged conversion, not compatible with}",
11917 N, First_Subtype (Opnd_Type));
11918 return False;
11919 end if;
11920 end Valid_Tagged_Conversion;
11922 -- Start of processing for Valid_Conversion
11924 begin
11925 Check_Parameterless_Call (Operand);
11927 if Is_Overloaded (Operand) then
11928 declare
11929 I : Interp_Index;
11930 I1 : Interp_Index;
11931 It : Interp;
11932 It1 : Interp;
11933 N1 : Entity_Id;
11934 T1 : Entity_Id;
11936 begin
11937 -- Remove procedure calls, which syntactically cannot appear in
11938 -- this context, but which cannot be removed by type checking,
11939 -- because the context does not impose a type.
11941 -- The node may be labelled overloaded, but still contain only one
11942 -- interpretation because others were discarded earlier. If this
11943 -- is the case, retain the single interpretation if legal.
11945 Get_First_Interp (Operand, I, It);
11946 Opnd_Type := It.Typ;
11947 Get_Next_Interp (I, It);
11949 if Present (It.Typ)
11950 and then Opnd_Type /= Standard_Void_Type
11951 then
11952 -- More than one candidate interpretation is available
11954 Get_First_Interp (Operand, I, It);
11955 while Present (It.Typ) loop
11956 if It.Typ = Standard_Void_Type then
11957 Remove_Interp (I);
11958 end if;
11960 -- When compiling for a system where Address is of a visible
11961 -- integer type, spurious ambiguities can be produced when
11962 -- arithmetic operations have a literal operand and return
11963 -- System.Address or a descendant of it. These ambiguities
11964 -- are usually resolved by the context, but for conversions
11965 -- there is no context type and the removal of the spurious
11966 -- operations must be done explicitly here.
11968 if not Address_Is_Private
11969 and then Is_Descendent_Of_Address (It.Typ)
11970 then
11971 Remove_Interp (I);
11972 end if;
11974 Get_Next_Interp (I, It);
11975 end loop;
11976 end if;
11978 Get_First_Interp (Operand, I, It);
11979 I1 := I;
11980 It1 := It;
11982 if No (It.Typ) then
11983 Conversion_Error_N ("illegal operand in conversion", Operand);
11984 return False;
11985 end if;
11987 Get_Next_Interp (I, It);
11989 if Present (It.Typ) then
11990 N1 := It1.Nam;
11991 T1 := It1.Typ;
11992 It1 := Disambiguate (Operand, I1, I, Any_Type);
11994 if It1 = No_Interp then
11995 Conversion_Error_N
11996 ("ambiguous operand in conversion", Operand);
11998 -- If the interpretation involves a standard operator, use
11999 -- the location of the type, which may be user-defined.
12001 if Sloc (It.Nam) = Standard_Location then
12002 Error_Msg_Sloc := Sloc (It.Typ);
12003 else
12004 Error_Msg_Sloc := Sloc (It.Nam);
12005 end if;
12007 Conversion_Error_N -- CODEFIX
12008 ("\\possible interpretation#!", Operand);
12010 if Sloc (N1) = Standard_Location then
12011 Error_Msg_Sloc := Sloc (T1);
12012 else
12013 Error_Msg_Sloc := Sloc (N1);
12014 end if;
12016 Conversion_Error_N -- CODEFIX
12017 ("\\possible interpretation#!", Operand);
12019 return False;
12020 end if;
12021 end if;
12023 Set_Etype (Operand, It1.Typ);
12024 Opnd_Type := It1.Typ;
12025 end;
12026 end if;
12028 -- Deal with conversion of integer type to address if the pragma
12029 -- Allow_Integer_Address is in effect. We convert the conversion to
12030 -- an unchecked conversion in this case and we are all done.
12032 if Address_Integer_Convert_OK (Opnd_Type, Target_Type) then
12033 Rewrite (N, Unchecked_Convert_To (Target_Type, Expression (N)));
12034 Analyze_And_Resolve (N, Target_Type);
12035 return True;
12036 end if;
12038 -- If we are within a child unit, check whether the type of the
12039 -- expression has an ancestor in a parent unit, in which case it
12040 -- belongs to its derivation class even if the ancestor is private.
12041 -- See RM 7.3.1 (5.2/3).
12043 Inc_Ancestor := Get_Incomplete_View_Of_Ancestor (Opnd_Type);
12045 -- Numeric types
12047 if Is_Numeric_Type (Target_Type) then
12049 -- A universal fixed expression can be converted to any numeric type
12051 if Opnd_Type = Universal_Fixed then
12052 return True;
12054 -- Also no need to check when in an instance or inlined body, because
12055 -- the legality has been established when the template was analyzed.
12056 -- Furthermore, numeric conversions may occur where only a private
12057 -- view of the operand type is visible at the instantiation point.
12058 -- This results in a spurious error if we check that the operand type
12059 -- is a numeric type.
12061 -- Note: in a previous version of this unit, the following tests were
12062 -- applied only for generated code (Comes_From_Source set to False),
12063 -- but in fact the test is required for source code as well, since
12064 -- this situation can arise in source code.
12066 elsif In_Instance or else In_Inlined_Body then
12067 return True;
12069 -- Otherwise we need the conversion check
12071 else
12072 return Conversion_Check
12073 (Is_Numeric_Type (Opnd_Type)
12074 or else
12075 (Present (Inc_Ancestor)
12076 and then Is_Numeric_Type (Inc_Ancestor)),
12077 "illegal operand for numeric conversion");
12078 end if;
12080 -- Array types
12082 elsif Is_Array_Type (Target_Type) then
12083 if not Is_Array_Type (Opnd_Type)
12084 or else Opnd_Type = Any_Composite
12085 or else Opnd_Type = Any_String
12086 then
12087 Conversion_Error_N
12088 ("illegal operand for array conversion", Operand);
12089 return False;
12091 else
12092 return Valid_Array_Conversion;
12093 end if;
12095 -- Ada 2005 (AI-251): Internally generated conversions of access to
12096 -- interface types added to force the displacement of the pointer to
12097 -- reference the corresponding dispatch table.
12099 elsif not Comes_From_Source (N)
12100 and then Is_Access_Type (Target_Type)
12101 and then Is_Interface (Designated_Type (Target_Type))
12102 then
12103 return True;
12105 -- Ada 2005 (AI-251): Anonymous access types where target references an
12106 -- interface type.
12108 elsif Ekind_In (Target_Type, E_General_Access_Type,
12109 E_Anonymous_Access_Type)
12110 and then Is_Interface (Directly_Designated_Type (Target_Type))
12111 then
12112 -- Check the static accessibility rule of 4.6(17). Note that the
12113 -- check is not enforced when within an instance body, since the
12114 -- RM requires such cases to be caught at run time.
12116 -- If the operand is a rewriting of an allocator no check is needed
12117 -- because there are no accessibility issues.
12119 if Nkind (Original_Node (N)) = N_Allocator then
12120 null;
12122 elsif Ekind (Target_Type) /= E_Anonymous_Access_Type then
12123 if Type_Access_Level (Opnd_Type) >
12124 Deepest_Type_Access_Level (Target_Type)
12125 then
12126 -- In an instance, this is a run-time check, but one we know
12127 -- will fail, so generate an appropriate warning. The raise
12128 -- will be generated by Expand_N_Type_Conversion.
12130 if In_Instance_Body then
12131 Error_Msg_Warn := SPARK_Mode /= On;
12132 Conversion_Error_N
12133 ("cannot convert local pointer to non-local access type<<",
12134 Operand);
12135 Conversion_Error_N ("\Program_Error [<<", Operand);
12137 else
12138 Conversion_Error_N
12139 ("cannot convert local pointer to non-local access type",
12140 Operand);
12141 return False;
12142 end if;
12144 -- Special accessibility checks are needed in the case of access
12145 -- discriminants declared for a limited type.
12147 elsif Ekind (Opnd_Type) = E_Anonymous_Access_Type
12148 and then not Is_Local_Anonymous_Access (Opnd_Type)
12149 then
12150 -- When the operand is a selected access discriminant the check
12151 -- needs to be made against the level of the object denoted by
12152 -- the prefix of the selected name (Object_Access_Level handles
12153 -- checking the prefix of the operand for this case).
12155 if Nkind (Operand) = N_Selected_Component
12156 and then Object_Access_Level (Operand) >
12157 Deepest_Type_Access_Level (Target_Type)
12158 then
12159 -- In an instance, this is a run-time check, but one we know
12160 -- will fail, so generate an appropriate warning. The raise
12161 -- will be generated by Expand_N_Type_Conversion.
12163 if In_Instance_Body then
12164 Error_Msg_Warn := SPARK_Mode /= On;
12165 Conversion_Error_N
12166 ("cannot convert access discriminant to non-local "
12167 & "access type<<", Operand);
12168 Conversion_Error_N ("\Program_Error [<<", Operand);
12170 -- Real error if not in instance body
12172 else
12173 Conversion_Error_N
12174 ("cannot convert access discriminant to non-local "
12175 & "access type", Operand);
12176 return False;
12177 end if;
12178 end if;
12180 -- The case of a reference to an access discriminant from
12181 -- within a limited type declaration (which will appear as
12182 -- a discriminal) is always illegal because the level of the
12183 -- discriminant is considered to be deeper than any (nameable)
12184 -- access type.
12186 if Is_Entity_Name (Operand)
12187 and then not Is_Local_Anonymous_Access (Opnd_Type)
12188 and then
12189 Ekind_In (Entity (Operand), E_In_Parameter, E_Constant)
12190 and then Present (Discriminal_Link (Entity (Operand)))
12191 then
12192 Conversion_Error_N
12193 ("discriminant has deeper accessibility level than target",
12194 Operand);
12195 return False;
12196 end if;
12197 end if;
12198 end if;
12200 return True;
12202 -- General and anonymous access types
12204 elsif Ekind_In (Target_Type, E_General_Access_Type,
12205 E_Anonymous_Access_Type)
12206 and then
12207 Conversion_Check
12208 (Is_Access_Type (Opnd_Type)
12209 and then not
12210 Ekind_In (Opnd_Type, E_Access_Subprogram_Type,
12211 E_Access_Protected_Subprogram_Type),
12212 "must be an access-to-object type")
12213 then
12214 if Is_Access_Constant (Opnd_Type)
12215 and then not Is_Access_Constant (Target_Type)
12216 then
12217 Conversion_Error_N
12218 ("access-to-constant operand type not allowed", Operand);
12219 return False;
12220 end if;
12222 -- Check the static accessibility rule of 4.6(17). Note that the
12223 -- check is not enforced when within an instance body, since the RM
12224 -- requires such cases to be caught at run time.
12226 if Ekind (Target_Type) /= E_Anonymous_Access_Type
12227 or else Is_Local_Anonymous_Access (Target_Type)
12228 or else Nkind (Associated_Node_For_Itype (Target_Type)) =
12229 N_Object_Declaration
12230 then
12231 -- Ada 2012 (AI05-0149): Perform legality checking on implicit
12232 -- conversions from an anonymous access type to a named general
12233 -- access type. Such conversions are not allowed in the case of
12234 -- access parameters and stand-alone objects of an anonymous
12235 -- access type. The implicit conversion case is recognized by
12236 -- testing that Comes_From_Source is False and that it's been
12237 -- rewritten. The Comes_From_Source test isn't sufficient because
12238 -- nodes in inlined calls to predefined library routines can have
12239 -- Comes_From_Source set to False. (Is there a better way to test
12240 -- for implicit conversions???)
12242 if Ada_Version >= Ada_2012
12243 and then not Comes_From_Source (N)
12244 and then N /= Original_Node (N)
12245 and then Ekind (Target_Type) = E_General_Access_Type
12246 and then Ekind (Opnd_Type) = E_Anonymous_Access_Type
12247 then
12248 if Is_Itype (Opnd_Type) then
12250 -- Implicit conversions aren't allowed for objects of an
12251 -- anonymous access type, since such objects have nonstatic
12252 -- levels in Ada 2012.
12254 if Nkind (Associated_Node_For_Itype (Opnd_Type)) =
12255 N_Object_Declaration
12256 then
12257 Conversion_Error_N
12258 ("implicit conversion of stand-alone anonymous "
12259 & "access object not allowed", Operand);
12260 return False;
12262 -- Implicit conversions aren't allowed for anonymous access
12263 -- parameters. The "not Is_Local_Anonymous_Access_Type" test
12264 -- is done to exclude anonymous access results.
12266 elsif not Is_Local_Anonymous_Access (Opnd_Type)
12267 and then Nkind_In (Associated_Node_For_Itype (Opnd_Type),
12268 N_Function_Specification,
12269 N_Procedure_Specification)
12270 then
12271 Conversion_Error_N
12272 ("implicit conversion of anonymous access formal "
12273 & "not allowed", Operand);
12274 return False;
12276 -- This is a case where there's an enclosing object whose
12277 -- to which the "statically deeper than" relationship does
12278 -- not apply (such as an access discriminant selected from
12279 -- a dereference of an access parameter).
12281 elsif Object_Access_Level (Operand)
12282 = Scope_Depth (Standard_Standard)
12283 then
12284 Conversion_Error_N
12285 ("implicit conversion of anonymous access value "
12286 & "not allowed", Operand);
12287 return False;
12289 -- In other cases, the level of the operand's type must be
12290 -- statically less deep than that of the target type, else
12291 -- implicit conversion is disallowed (by RM12-8.6(27.1/3)).
12293 elsif Type_Access_Level (Opnd_Type) >
12294 Deepest_Type_Access_Level (Target_Type)
12295 then
12296 Conversion_Error_N
12297 ("implicit conversion of anonymous access value "
12298 & "violates accessibility", Operand);
12299 return False;
12300 end if;
12301 end if;
12303 elsif Type_Access_Level (Opnd_Type) >
12304 Deepest_Type_Access_Level (Target_Type)
12305 then
12306 -- In an instance, this is a run-time check, but one we know
12307 -- will fail, so generate an appropriate warning. The raise
12308 -- will be generated by Expand_N_Type_Conversion.
12310 if In_Instance_Body then
12311 Error_Msg_Warn := SPARK_Mode /= On;
12312 Conversion_Error_N
12313 ("cannot convert local pointer to non-local access type<<",
12314 Operand);
12315 Conversion_Error_N ("\Program_Error [<<", Operand);
12317 -- If not in an instance body, this is a real error
12319 else
12320 -- Avoid generation of spurious error message
12322 if not Error_Posted (N) then
12323 Conversion_Error_N
12324 ("cannot convert local pointer to non-local access type",
12325 Operand);
12326 end if;
12328 return False;
12329 end if;
12331 -- Special accessibility checks are needed in the case of access
12332 -- discriminants declared for a limited type.
12334 elsif Ekind (Opnd_Type) = E_Anonymous_Access_Type
12335 and then not Is_Local_Anonymous_Access (Opnd_Type)
12336 then
12337 -- When the operand is a selected access discriminant the check
12338 -- needs to be made against the level of the object denoted by
12339 -- the prefix of the selected name (Object_Access_Level handles
12340 -- checking the prefix of the operand for this case).
12342 if Nkind (Operand) = N_Selected_Component
12343 and then Object_Access_Level (Operand) >
12344 Deepest_Type_Access_Level (Target_Type)
12345 then
12346 -- In an instance, this is a run-time check, but one we know
12347 -- will fail, so generate an appropriate warning. The raise
12348 -- will be generated by Expand_N_Type_Conversion.
12350 if In_Instance_Body then
12351 Error_Msg_Warn := SPARK_Mode /= On;
12352 Conversion_Error_N
12353 ("cannot convert access discriminant to non-local "
12354 & "access type<<", Operand);
12355 Conversion_Error_N ("\Program_Error [<<", Operand);
12357 -- If not in an instance body, this is a real error
12359 else
12360 Conversion_Error_N
12361 ("cannot convert access discriminant to non-local "
12362 & "access type", Operand);
12363 return False;
12364 end if;
12365 end if;
12367 -- The case of a reference to an access discriminant from
12368 -- within a limited type declaration (which will appear as
12369 -- a discriminal) is always illegal because the level of the
12370 -- discriminant is considered to be deeper than any (nameable)
12371 -- access type.
12373 if Is_Entity_Name (Operand)
12374 and then
12375 Ekind_In (Entity (Operand), E_In_Parameter, E_Constant)
12376 and then Present (Discriminal_Link (Entity (Operand)))
12377 then
12378 Conversion_Error_N
12379 ("discriminant has deeper accessibility level than target",
12380 Operand);
12381 return False;
12382 end if;
12383 end if;
12384 end if;
12386 -- In the presence of limited_with clauses we have to use non-limited
12387 -- views, if available.
12389 Check_Limited : declare
12390 function Full_Designated_Type (T : Entity_Id) return Entity_Id;
12391 -- Helper function to handle limited views
12393 --------------------------
12394 -- Full_Designated_Type --
12395 --------------------------
12397 function Full_Designated_Type (T : Entity_Id) return Entity_Id is
12398 Desig : constant Entity_Id := Designated_Type (T);
12400 begin
12401 -- Handle the limited view of a type
12403 if Is_Incomplete_Type (Desig)
12404 and then From_Limited_With (Desig)
12405 and then Present (Non_Limited_View (Desig))
12406 then
12407 return Available_View (Desig);
12408 else
12409 return Desig;
12410 end if;
12411 end Full_Designated_Type;
12413 -- Local Declarations
12415 Target : constant Entity_Id := Full_Designated_Type (Target_Type);
12416 Opnd : constant Entity_Id := Full_Designated_Type (Opnd_Type);
12418 Same_Base : constant Boolean :=
12419 Base_Type (Target) = Base_Type (Opnd);
12421 -- Start of processing for Check_Limited
12423 begin
12424 if Is_Tagged_Type (Target) then
12425 return Valid_Tagged_Conversion (Target, Opnd);
12427 else
12428 if not Same_Base then
12429 Conversion_Error_NE
12430 ("target designated type not compatible with }",
12431 N, Base_Type (Opnd));
12432 return False;
12434 -- Ada 2005 AI-384: legality rule is symmetric in both
12435 -- designated types. The conversion is legal (with possible
12436 -- constraint check) if either designated type is
12437 -- unconstrained.
12439 elsif Subtypes_Statically_Match (Target, Opnd)
12440 or else
12441 (Has_Discriminants (Target)
12442 and then
12443 (not Is_Constrained (Opnd)
12444 or else not Is_Constrained (Target)))
12445 then
12446 -- Special case, if Value_Size has been used to make the
12447 -- sizes different, the conversion is not allowed even
12448 -- though the subtypes statically match.
12450 if Known_Static_RM_Size (Target)
12451 and then Known_Static_RM_Size (Opnd)
12452 and then RM_Size (Target) /= RM_Size (Opnd)
12453 then
12454 Conversion_Error_NE
12455 ("target designated subtype not compatible with }",
12456 N, Opnd);
12457 Conversion_Error_NE
12458 ("\because sizes of the two designated subtypes differ",
12459 N, Opnd);
12460 return False;
12462 -- Normal case where conversion is allowed
12464 else
12465 return True;
12466 end if;
12468 else
12469 Error_Msg_NE
12470 ("target designated subtype not compatible with }",
12471 N, Opnd);
12472 return False;
12473 end if;
12474 end if;
12475 end Check_Limited;
12477 -- Access to subprogram types. If the operand is an access parameter,
12478 -- the type has a deeper accessibility that any master, and cannot be
12479 -- assigned. We must make an exception if the conversion is part of an
12480 -- assignment and the target is the return object of an extended return
12481 -- statement, because in that case the accessibility check takes place
12482 -- after the return.
12484 elsif Is_Access_Subprogram_Type (Target_Type)
12486 -- Note: this test of Opnd_Type is there to prevent entering this
12487 -- branch in the case of a remote access to subprogram type, which
12488 -- is internally represented as an E_Record_Type.
12490 and then Is_Access_Type (Opnd_Type)
12491 then
12492 if Ekind (Base_Type (Opnd_Type)) = E_Anonymous_Access_Subprogram_Type
12493 and then Is_Entity_Name (Operand)
12494 and then Ekind (Entity (Operand)) = E_In_Parameter
12495 and then
12496 (Nkind (Parent (N)) /= N_Assignment_Statement
12497 or else not Is_Entity_Name (Name (Parent (N)))
12498 or else not Is_Return_Object (Entity (Name (Parent (N)))))
12499 then
12500 Conversion_Error_N
12501 ("illegal attempt to store anonymous access to subprogram",
12502 Operand);
12503 Conversion_Error_N
12504 ("\value has deeper accessibility than any master "
12505 & "(RM 3.10.2 (13))",
12506 Operand);
12508 Error_Msg_NE
12509 ("\use named access type for& instead of access parameter",
12510 Operand, Entity (Operand));
12511 end if;
12513 -- Check that the designated types are subtype conformant
12515 Check_Subtype_Conformant (New_Id => Designated_Type (Target_Type),
12516 Old_Id => Designated_Type (Opnd_Type),
12517 Err_Loc => N);
12519 -- Check the static accessibility rule of 4.6(20)
12521 if Type_Access_Level (Opnd_Type) >
12522 Deepest_Type_Access_Level (Target_Type)
12523 then
12524 Conversion_Error_N
12525 ("operand type has deeper accessibility level than target",
12526 Operand);
12528 -- Check that if the operand type is declared in a generic body,
12529 -- then the target type must be declared within that same body
12530 -- (enforces last sentence of 4.6(20)).
12532 elsif Present (Enclosing_Generic_Body (Opnd_Type)) then
12533 declare
12534 O_Gen : constant Node_Id :=
12535 Enclosing_Generic_Body (Opnd_Type);
12537 T_Gen : Node_Id;
12539 begin
12540 T_Gen := Enclosing_Generic_Body (Target_Type);
12541 while Present (T_Gen) and then T_Gen /= O_Gen loop
12542 T_Gen := Enclosing_Generic_Body (T_Gen);
12543 end loop;
12545 if T_Gen /= O_Gen then
12546 Conversion_Error_N
12547 ("target type must be declared in same generic body "
12548 & "as operand type", N);
12549 end if;
12550 end;
12551 end if;
12553 return True;
12555 -- Remote access to subprogram types
12557 elsif Is_Remote_Access_To_Subprogram_Type (Target_Type)
12558 and then Is_Remote_Access_To_Subprogram_Type (Opnd_Type)
12559 then
12560 -- It is valid to convert from one RAS type to another provided
12561 -- that their specification statically match.
12563 -- Note: at this point, remote access to subprogram types have been
12564 -- expanded to their E_Record_Type representation, and we need to
12565 -- go back to the original access type definition using the
12566 -- Corresponding_Remote_Type attribute in order to check that the
12567 -- designated profiles match.
12569 pragma Assert (Ekind (Target_Type) = E_Record_Type);
12570 pragma Assert (Ekind (Opnd_Type) = E_Record_Type);
12572 Check_Subtype_Conformant
12573 (New_Id =>
12574 Designated_Type (Corresponding_Remote_Type (Target_Type)),
12575 Old_Id =>
12576 Designated_Type (Corresponding_Remote_Type (Opnd_Type)),
12577 Err_Loc =>
12579 return True;
12581 -- If it was legal in the generic, it's legal in the instance
12583 elsif In_Instance_Body then
12584 return True;
12586 -- If both are tagged types, check legality of view conversions
12588 elsif Is_Tagged_Type (Target_Type)
12589 and then
12590 Is_Tagged_Type (Opnd_Type)
12591 then
12592 return Valid_Tagged_Conversion (Target_Type, Opnd_Type);
12594 -- Types derived from the same root type are convertible
12596 elsif Root_Type (Target_Type) = Root_Type (Opnd_Type) then
12597 return True;
12599 -- In an instance or an inlined body, there may be inconsistent views of
12600 -- the same type, or of types derived from a common root.
12602 elsif (In_Instance or In_Inlined_Body)
12603 and then
12604 Root_Type (Underlying_Type (Target_Type)) =
12605 Root_Type (Underlying_Type (Opnd_Type))
12606 then
12607 return True;
12609 -- Special check for common access type error case
12611 elsif Ekind (Target_Type) = E_Access_Type
12612 and then Is_Access_Type (Opnd_Type)
12613 then
12614 Conversion_Error_N ("target type must be general access type!", N);
12615 Conversion_Error_NE -- CODEFIX
12616 ("add ALL to }!", N, Target_Type);
12617 return False;
12619 -- Here we have a real conversion error
12621 else
12622 Conversion_Error_NE
12623 ("invalid conversion, not compatible with }", N, Opnd_Type);
12624 return False;
12625 end if;
12626 end Valid_Conversion;
12628 end Sem_Res;