1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2003, Free Software Foundation, Inc. --
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 2, 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 COPYING. If not, write --
19 -- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, --
20 -- MA 02111-1307, USA. --
22 -- GNAT was originally developed by the GNAT team at New York University. --
23 -- Extensive contributions were provided by Ada Core Technologies Inc. --
25 ------------------------------------------------------------------------------
27 with Atree
; use Atree
;
28 with Debug
; use Debug
;
29 with Einfo
; use Einfo
;
30 with Elists
; use Elists
;
31 with Errout
; use Errout
;
32 with Exp_Util
; use Exp_Util
;
33 with Fname
; use Fname
;
34 with Freeze
; use Freeze
;
36 with Lib
.Load
; use Lib
.Load
;
37 with Lib
.Xref
; use Lib
.Xref
;
38 with Namet
; use Namet
;
39 with Nlists
; use Nlists
;
40 with Nmake
; use Nmake
;
42 with Output
; use Output
;
43 with Restrict
; use Restrict
;
44 with Rtsfind
; use Rtsfind
;
46 with Sem_Cat
; use Sem_Cat
;
47 with Sem_Ch3
; use Sem_Ch3
;
48 with Sem_Ch4
; use Sem_Ch4
;
49 with Sem_Ch6
; use Sem_Ch6
;
50 with Sem_Ch12
; use Sem_Ch12
;
51 with Sem_Res
; use Sem_Res
;
52 with Sem_Util
; use Sem_Util
;
53 with Sem_Type
; use Sem_Type
;
54 with Stand
; use Stand
;
55 with Sinfo
; use Sinfo
;
56 with Sinfo
.CN
; use Sinfo
.CN
;
57 with Snames
; use Snames
;
58 with Style
; use Style
;
60 with Tbuild
; use Tbuild
;
61 with Uintp
; use Uintp
;
63 with GNAT
.Spelling_Checker
; use GNAT
.Spelling_Checker
;
65 package body Sem_Ch8
is
67 ------------------------------------
68 -- Visibility and Name Resolution --
69 ------------------------------------
71 -- This package handles name resolution and the collection of
72 -- interpretations for overloaded names, prior to overload resolution.
74 -- Name resolution is the process that establishes a mapping between source
75 -- identifiers and the entities they denote at each point in the program.
76 -- Each entity is represented by a defining occurrence. Each identifier
77 -- that denotes an entity points to the corresponding defining occurrence.
78 -- This is the entity of the applied occurrence. Each occurrence holds
79 -- an index into the names table, where source identifiers are stored.
81 -- Each entry in the names table for an identifier or designator uses the
82 -- Info pointer to hold a link to the currently visible entity that has
83 -- this name (see subprograms Get_Name_Entity_Id and Set_Name_Entity_Id
84 -- in package Sem_Util). The visibility is initialized at the beginning of
85 -- semantic processing to make entities in package Standard immediately
86 -- visible. The visibility table is used in a more subtle way when
87 -- compiling subunits (see below).
89 -- Entities that have the same name (i.e. homonyms) are chained. In the
90 -- case of overloaded entities, this chain holds all the possible meanings
91 -- of a given identifier. The process of overload resolution uses type
92 -- information to select from this chain the unique meaning of a given
95 -- Entities are also chained in their scope, through the Next_Entity link.
96 -- As a consequence, the name space is organized as a sparse matrix, where
97 -- each row corresponds to a scope, and each column to a source identifier.
98 -- Open scopes, that is to say scopes currently being compiled, have their
99 -- corresponding rows of entities in order, innermost scope first.
101 -- The scopes of packages that are mentioned in context clauses appear in
102 -- no particular order, interspersed among open scopes. This is because
103 -- in the course of analyzing the context of a compilation, a package
104 -- declaration is first an open scope, and subsequently an element of the
105 -- context. If subunits or child units are present, a parent unit may
106 -- appear under various guises at various times in the compilation.
108 -- When the compilation of the innermost scope is complete, the entities
109 -- defined therein are no longer visible. If the scope is not a package
110 -- declaration, these entities are never visible subsequently, and can be
111 -- removed from visibility chains. If the scope is a package declaration,
112 -- its visible declarations may still be accessible. Therefore the entities
113 -- defined in such a scope are left on the visibility chains, and only
114 -- their visibility (immediately visibility or potential use-visibility)
117 -- The ordering of homonyms on their chain does not necessarily follow
118 -- the order of their corresponding scopes on the scope stack. For
119 -- example, if package P and the enclosing scope both contain entities
120 -- named E, then when compiling the package body the chain for E will
121 -- hold the global entity first, and the local one (corresponding to
122 -- the current inner scope) next. As a result, name resolution routines
123 -- do not assume any relative ordering of the homonym chains, either
124 -- for scope nesting or to order of appearance of context clauses.
126 -- When compiling a child unit, entities in the parent scope are always
127 -- immediately visible. When compiling the body of a child unit, private
128 -- entities in the parent must also be made immediately visible. There
129 -- are separate routines to make the visible and private declarations
130 -- visible at various times (see package Sem_Ch7).
132 -- +--------+ +-----+
133 -- | In use |-------->| EU1 |-------------------------->
134 -- +--------+ +-----+
136 -- +--------+ +-----+ +-----+
137 -- | Stand. |---------------->| ES1 |--------------->| ES2 |--->
138 -- +--------+ +-----+ +-----+
140 -- +---------+ | +-----+
141 -- | with'ed |------------------------------>| EW2 |--->
142 -- +---------+ | +-----+
144 -- +--------+ +-----+ +-----+
145 -- | Scope2 |---------------->| E12 |--------------->| E22 |--->
146 -- +--------+ +-----+ +-----+
148 -- +--------+ +-----+ +-----+
149 -- | Scope1 |---------------->| E11 |--------------->| E12 |--->
150 -- +--------+ +-----+ +-----+
154 -- | | with'ed |----------------------------------------->
158 -- (innermost first) | |
159 -- +----------------------------+
160 -- Names table => | Id1 | | | | Id2 |
161 -- +----------------------------+
163 -- Name resolution must deal with several syntactic forms: simple names,
164 -- qualified names, indexed names, and various forms of calls.
166 -- Each identifier points to an entry in the names table. The resolution
167 -- of a simple name consists in traversing the homonym chain, starting
168 -- from the names table. If an entry is immediately visible, it is the one
169 -- designated by the identifier. If only potentially use-visible entities
170 -- are on the chain, we must verify that they do not hide each other. If
171 -- the entity we find is overloadable, we collect all other overloadable
172 -- entities on the chain as long as they are not hidden.
174 -- To resolve expanded names, we must find the entity at the intersection
175 -- of the entity chain for the scope (the prefix) and the homonym chain
176 -- for the selector. In general, homonym chains will be much shorter than
177 -- entity chains, so it is preferable to start from the names table as
178 -- well. If the entity found is overloadable, we must collect all other
179 -- interpretations that are defined in the scope denoted by the prefix.
181 -- For records, protected types, and tasks, their local entities are
182 -- removed from visibility chains on exit from the corresponding scope.
183 -- From the outside, these entities are always accessed by selected
184 -- notation, and the entity chain for the record type, protected type,
185 -- etc. is traversed sequentially in order to find the designated entity.
187 -- The discriminants of a type and the operations of a protected type or
188 -- task are unchained on exit from the first view of the type, (such as
189 -- a private or incomplete type declaration, or a protected type speci-
190 -- fication) and re-chained when compiling the second view.
192 -- In the case of operators, we do not make operators on derived types
193 -- explicit. As a result, the notation P."+" may denote either a user-
194 -- defined function with name "+", or else an implicit declaration of the
195 -- operator "+" in package P. The resolution of expanded names always
196 -- tries to resolve an operator name as such an implicitly defined entity,
197 -- in addition to looking for explicit declarations.
199 -- All forms of names that denote entities (simple names, expanded names,
200 -- character literals in some cases) have a Entity attribute, which
201 -- identifies the entity denoted by the name.
203 ---------------------
204 -- The Scope Stack --
205 ---------------------
207 -- The Scope stack keeps track of the scopes currently been compiled.
208 -- Every entity that contains declarations (including records) is placed
209 -- on the scope stack while it is being processed, and removed at the end.
210 -- Whenever a non-package scope is exited, the entities defined therein
211 -- are removed from the visibility table, so that entities in outer scopes
212 -- become visible (see previous description). On entry to Sem, the scope
213 -- stack only contains the package Standard. As usual, subunits complicate
214 -- this picture ever so slightly.
216 -- The Rtsfind mechanism can force a call to Semantics while another
217 -- compilation is in progress. The unit retrieved by Rtsfind must be
218 -- compiled in its own context, and has no access to the visibility of
219 -- the unit currently being compiled. The procedures Save_Scope_Stack and
220 -- Restore_Scope_Stack make entities in current open scopes invisible
221 -- before compiling the retrieved unit, and restore the compilation
222 -- environment afterwards.
224 ------------------------
225 -- Compiling subunits --
226 ------------------------
228 -- Subunits must be compiled in the environment of the corresponding
229 -- stub, that is to say with the same visibility into the parent (and its
230 -- context) that is available at the point of the stub declaration, but
231 -- with the additional visibility provided by the context clause of the
232 -- subunit itself. As a result, compilation of a subunit forces compilation
233 -- of the parent (see description in lib-). At the point of the stub
234 -- declaration, Analyze is called recursively to compile the proper body
235 -- of the subunit, but without reinitializing the names table, nor the
236 -- scope stack (i.e. standard is not pushed on the stack). In this fashion
237 -- the context of the subunit is added to the context of the parent, and
238 -- the subunit is compiled in the correct environment. Note that in the
239 -- course of processing the context of a subunit, Standard will appear
240 -- twice on the scope stack: once for the parent of the subunit, and
241 -- once for the unit in the context clause being compiled. However, the
242 -- two sets of entities are not linked by homonym chains, so that the
243 -- compilation of any context unit happens in a fresh visibility
246 -------------------------------
247 -- Processing of USE Clauses --
248 -------------------------------
250 -- Every defining occurrence has a flag indicating if it is potentially use
251 -- visible. Resolution of simple names examines this flag. The processing
252 -- of use clauses consists in setting this flag on all visible entities
253 -- defined in the corresponding package. On exit from the scope of the use
254 -- clause, the corresponding flag must be reset. However, a package may
255 -- appear in several nested use clauses (pathological but legal, alas!)
256 -- which forces us to use a slightly more involved scheme:
258 -- a) The defining occurrence for a package holds a flag -In_Use- to
259 -- indicate that it is currently in the scope of a use clause. If a
260 -- redundant use clause is encountered, then the corresponding occurrence
261 -- of the package name is flagged -Redundant_Use-.
263 -- b) On exit from a scope, the use clauses in its declarative part are
264 -- scanned. The visibility flag is reset in all entities declared in
265 -- package named in a use clause, as long as the package is not flagged
266 -- as being in a redundant use clause (in which case the outer use
267 -- clause is still in effect, and the direct visibility of its entities
268 -- must be retained).
270 -- Note that entities are not removed from their homonym chains on exit
271 -- from the package specification. A subsequent use clause does not need
272 -- to rechain the visible entities, but only to establish their direct
275 -----------------------------------
276 -- Handling private declarations --
277 -----------------------------------
279 -- The principle that each entity has a single defining occurrence clashes
280 -- with the presence of two separate definitions for private types: the
281 -- first is the private type declaration, and second is the full type
282 -- declaration. It is important that all references to the type point to
283 -- the same defining occurrence, namely the first one. To enforce the two
284 -- separate views of the entity, the corresponding information is swapped
285 -- between the two declarations. Outside of the package, the defining
286 -- occurrence only contains the private declaration information, while in
287 -- the private part and the body of the package the defining occurrence
288 -- contains the full declaration. To simplify the swap, the defining
289 -- occurrence that currently holds the private declaration points to the
290 -- full declaration. During semantic processing the defining occurrence
291 -- also points to a list of private dependents, that is to say access
292 -- types or composite types whose designated types or component types are
293 -- subtypes or derived types of the private type in question. After the
294 -- full declaration has been seen, the private dependents are updated to
295 -- indicate that they have full definitions.
297 ------------------------------------
298 -- Handling of Undefined Messages --
299 ------------------------------------
301 -- In normal mode, only the first use of an undefined identifier generates
302 -- a message. The table Urefs is used to record error messages that have
303 -- been issued so that second and subsequent ones do not generate further
304 -- messages. However, the second reference causes text to be added to the
305 -- original undefined message noting "(more references follow)". The
306 -- full error list option (-gnatf) forces messages to be generated for
307 -- every reference and disconnects the use of this table.
309 type Uref_Entry
is record
311 -- Node for identifier for which original message was posted. The
312 -- Chars field of this identifier is used to detect later references
313 -- to the same identifier.
316 -- Records error message Id of original undefined message. Reset to
317 -- No_Error_Msg after the second occurrence, where it is used to add
318 -- text to the original message as described above.
321 -- Set if the message is not visible rather than undefined
324 -- Records location of error message. Used to make sure that we do
325 -- not consider a, b : undefined as two separate instances, which
326 -- would otherwise happen, since the parser converts this sequence
327 -- to a : undefined; b : undefined.
331 package Urefs
is new Table
.Table
(
332 Table_Component_Type
=> Uref_Entry
,
333 Table_Index_Type
=> Nat
,
334 Table_Low_Bound
=> 1,
336 Table_Increment
=> 100,
337 Table_Name
=> "Urefs");
339 Candidate_Renaming
: Entity_Id
;
340 -- Holds a candidate interpretation that appears in a subprogram renaming
341 -- declaration and does not match the given specification, but matches at
342 -- least on the first formal. Allows better error message when given
343 -- specification omits defaulted parameters, a common error.
345 -----------------------
346 -- Local Subprograms --
347 -----------------------
349 procedure Analyze_Generic_Renaming
352 -- Common processing for all three kinds of generic renaming declarations.
353 -- Enter new name and indicate that it renames the generic unit.
355 procedure Analyze_Renamed_Character
359 -- Renamed entity is given by a character literal, which must belong
360 -- to the return type of the new entity. Is_Body indicates whether the
361 -- declaration is a renaming_as_body. If the original declaration has
362 -- already been frozen (because of an intervening body, e.g.) the body of
363 -- the function must be built now. The same applies to the following
364 -- various renaming procedures.
366 procedure Analyze_Renamed_Dereference
370 -- Renamed entity is given by an explicit dereference. Prefix must be a
371 -- conformant access_to_subprogram type.
373 procedure Analyze_Renamed_Entry
377 -- If the renamed entity in a subprogram renaming is an entry or protected
378 -- subprogram, build a body for the new entity whose only statement is a
379 -- call to the renamed entity.
381 procedure Analyze_Renamed_Family_Member
385 -- Used when the renamed entity is an indexed component. The prefix must
386 -- denote an entry family.
388 function Applicable_Use
(Pack_Name
: Node_Id
) return Boolean;
389 -- Common code to Use_One_Package and Set_Use, to determine whether
390 -- use clause must be processed. Pack_Name is an entity name that
391 -- references the package in question.
393 procedure Attribute_Renaming
(N
: Node_Id
);
394 -- Analyze renaming of attribute as function. The renaming declaration N
395 -- is rewritten as a function body that returns the attribute reference
396 -- applied to the formals of the function.
398 procedure Check_Frozen_Renaming
(N
: Node_Id
; Subp
: Entity_Id
);
399 -- A renaming_as_body may occur after the entity of the original decla-
400 -- ration has been frozen. In that case, the body of the new entity must
401 -- be built now, because the usual mechanism of building the renamed
402 -- body at the point of freezing will not work. Subp is the subprogram
403 -- for which N provides the Renaming_As_Body.
405 procedure Check_In_Previous_With_Clause
408 -- N is a use_package clause and Nam the package name, or N is a use_type
409 -- clause and Nam is the prefix of the type name. In either case, verify
410 -- that the package is visible at that point in the context: either it
411 -- appears in a previous with_clause, or because it is a fully qualified
412 -- name and the root ancestor appears in a previous with_clause.
414 procedure Check_Library_Unit_Renaming
(N
: Node_Id
; Old_E
: Entity_Id
);
415 -- Verify that the entity in a renaming declaration that is a library unit
416 -- is itself a library unit and not a nested unit or subunit. Also check
417 -- that if the renaming is a child unit of a generic parent, then the
418 -- renamed unit must also be a child unit of that parent. Finally, verify
419 -- that a renamed generic unit is not an implicit child declared within
420 -- an instance of the parent.
422 procedure Chain_Use_Clause
(N
: Node_Id
);
423 -- Chain use clause onto list of uses clauses headed by First_Use_Clause
424 -- in the top scope table entry.
426 function Has_Implicit_Character_Literal
(N
: Node_Id
) return Boolean;
427 -- Find a type derived from Character or Wide_Character in the prefix of N.
428 -- Used to resolved qualified names whose selector is a character literal.
430 procedure Find_Expanded_Name
(N
: Node_Id
);
431 -- Selected component is known to be expanded name. Verify legality
432 -- of selector given the scope denoted by prefix.
434 function Find_Renamed_Entity
438 Is_Actual
: Boolean := False) return Entity_Id
;
439 -- Find the renamed entity that corresponds to the given parameter profile
440 -- in a subprogram renaming declaration. The renamed entity may be an
441 -- operator, a subprogram, an entry, or a protected operation. Is_Actual
442 -- indicates that the renaming is the one generated for an actual subpro-
443 -- gram in an instance, for which special visibility checks apply.
445 function Has_Implicit_Operator
(N
: Node_Id
) return Boolean;
446 -- N is an expanded name whose selector is an operator name (eg P."+").
447 -- A declarative part contains an implicit declaration of an operator
448 -- if it has a declaration of a type to which one of the predefined
449 -- operators apply. The existence of this routine is an artifact of
450 -- our implementation: a more straightforward but more space-consuming
451 -- choice would be to make all inherited operators explicit in the
454 procedure Inherit_Renamed_Profile
(New_S
: Entity_Id
; Old_S
: Entity_Id
);
455 -- A subprogram defined by a renaming declaration inherits the parameter
456 -- profile of the renamed entity. The subtypes given in the subprogram
457 -- specification are discarded and replaced with those of the renamed
458 -- subprogram, which are then used to recheck the default values.
460 function Is_Appropriate_For_Record
(T
: Entity_Id
) return Boolean;
461 -- Prefix is appropriate for record if it is of a record type, or
462 -- an access to such.
464 function Is_Appropriate_For_Entry_Prefix
(T
: Entity_Id
) return Boolean;
465 -- True if it is of a task type, a protected type, or else an access
466 -- to one of these types.
468 procedure Premature_Usage
(N
: Node_Id
);
469 -- Diagnose usage of an entity before it is visible.
471 procedure Use_One_Package
(P
: Entity_Id
; N
: Node_Id
);
472 -- Make visible entities declared in package P potentially use-visible
473 -- in the current context. Also used in the analysis of subunits, when
474 -- re-installing use clauses of parent units. N is the use_clause that
475 -- names P (and possibly other packages).
477 procedure Use_One_Type
(Id
: Node_Id
);
478 -- Id is the subtype mark from a use type clause. This procedure makes
479 -- the primitive operators of the type potentially use-visible.
481 procedure Write_Info
;
482 -- Write debugging information on entities declared in current scope
484 procedure Write_Scopes
;
485 pragma Warnings
(Off
, Write_Scopes
);
486 -- Debugging information: dump all entities on scope stack
488 --------------------------------
489 -- Analyze_Exception_Renaming --
490 --------------------------------
492 -- The language only allows a single identifier, but the tree holds
493 -- an identifier list. The parser has already issued an error message
494 -- if there is more than one element in the list.
496 procedure Analyze_Exception_Renaming
(N
: Node_Id
) is
497 Id
: constant Node_Id
:= Defining_Identifier
(N
);
498 Nam
: constant Node_Id
:= Name
(N
);
504 Set_Ekind
(Id
, E_Exception
);
505 Set_Exception_Code
(Id
, Uint_0
);
506 Set_Etype
(Id
, Standard_Exception_Type
);
507 Set_Is_Pure
(Id
, Is_Pure
(Current_Scope
));
509 if not Is_Entity_Name
(Nam
) or else
510 Ekind
(Entity
(Nam
)) /= E_Exception
512 Error_Msg_N
("invalid exception name in renaming", Nam
);
514 if Present
(Renamed_Object
(Entity
(Nam
))) then
515 Set_Renamed_Object
(Id
, Renamed_Object
(Entity
(Nam
)));
517 Set_Renamed_Object
(Id
, Entity
(Nam
));
520 end Analyze_Exception_Renaming
;
522 ---------------------------
523 -- Analyze_Expanded_Name --
524 ---------------------------
526 procedure Analyze_Expanded_Name
(N
: Node_Id
) is
528 -- If the entity pointer is already set, this is an internal node, or
529 -- a node that is analyzed more than once, after a tree modification.
530 -- In such a case there is no resolution to perform, just set the type.
531 -- For completeness, analyze prefix as well.
533 if Present
(Entity
(N
)) then
534 if Is_Type
(Entity
(N
)) then
535 Set_Etype
(N
, Entity
(N
));
537 Set_Etype
(N
, Etype
(Entity
(N
)));
540 Analyze
(Prefix
(N
));
543 Find_Expanded_Name
(N
);
545 end Analyze_Expanded_Name
;
547 ----------------------------------------
548 -- Analyze_Generic_Function_Renaming --
549 ----------------------------------------
551 procedure Analyze_Generic_Function_Renaming
(N
: Node_Id
) is
553 Analyze_Generic_Renaming
(N
, E_Generic_Function
);
554 end Analyze_Generic_Function_Renaming
;
556 ---------------------------------------
557 -- Analyze_Generic_Package_Renaming --
558 ---------------------------------------
560 procedure Analyze_Generic_Package_Renaming
(N
: Node_Id
) is
562 -- Apply the Text_IO Kludge here, since we may be renaming
563 -- one of the subpackages of Text_IO, then join common routine.
565 Text_IO_Kludge
(Name
(N
));
567 Analyze_Generic_Renaming
(N
, E_Generic_Package
);
568 end Analyze_Generic_Package_Renaming
;
570 -----------------------------------------
571 -- Analyze_Generic_Procedure_Renaming --
572 -----------------------------------------
574 procedure Analyze_Generic_Procedure_Renaming
(N
: Node_Id
) is
576 Analyze_Generic_Renaming
(N
, E_Generic_Procedure
);
577 end Analyze_Generic_Procedure_Renaming
;
579 ------------------------------
580 -- Analyze_Generic_Renaming --
581 ------------------------------
583 procedure Analyze_Generic_Renaming
587 New_P
: constant Entity_Id
:= Defining_Entity
(N
);
589 Inst
: Boolean := False; -- prevent junk warning
592 if Name
(N
) = Error
then
596 Generate_Definition
(New_P
);
598 if Current_Scope
/= Standard_Standard
then
599 Set_Is_Pure
(New_P
, Is_Pure
(Current_Scope
));
602 if Nkind
(Name
(N
)) = N_Selected_Component
then
603 Check_Generic_Child_Unit
(Name
(N
), Inst
);
608 if not Is_Entity_Name
(Name
(N
)) then
609 Error_Msg_N
("expect entity name in renaming declaration", Name
(N
));
612 Old_P
:= Entity
(Name
(N
));
616 Set_Ekind
(New_P
, K
);
618 if Etype
(Old_P
) = Any_Type
then
621 elsif Ekind
(Old_P
) /= K
then
622 Error_Msg_N
("invalid generic unit name", Name
(N
));
625 if Present
(Renamed_Object
(Old_P
)) then
626 Set_Renamed_Object
(New_P
, Renamed_Object
(Old_P
));
628 Set_Renamed_Object
(New_P
, Old_P
);
631 Set_Etype
(New_P
, Etype
(Old_P
));
632 Set_Has_Completion
(New_P
);
634 if In_Open_Scopes
(Old_P
) then
635 Error_Msg_N
("within its scope, generic denotes its instance", N
);
638 Check_Library_Unit_Renaming
(N
, Old_P
);
641 end Analyze_Generic_Renaming
;
643 -----------------------------
644 -- Analyze_Object_Renaming --
645 -----------------------------
647 procedure Analyze_Object_Renaming
(N
: Node_Id
) is
648 Id
: constant Entity_Id
:= Defining_Identifier
(N
);
650 Nam
: constant Node_Id
:= Name
(N
);
651 S
: constant Entity_Id
:= Subtype_Mark
(N
);
660 Set_Is_Pure
(Id
, Is_Pure
(Current_Scope
));
663 -- The renaming of a component that depends on a discriminant
664 -- requires an actual subtype, because in subsequent use of the object
665 -- Gigi will be unable to locate the actual bounds. This explicit step
666 -- is required when the renaming is generated in removing side effects
667 -- of an already-analyzed expression.
669 if Nkind
(Nam
) = N_Selected_Component
670 and then Analyzed
(Nam
)
673 Dec
:= Build_Actual_Subtype_Of_Component
(Etype
(Nam
), Nam
);
675 if Present
(Dec
) then
676 Insert_Action
(N
, Dec
);
677 T
:= Defining_Identifier
(Dec
);
684 Analyze_And_Resolve
(Nam
, T
);
687 -- An object renaming requires an exact match of the type;
688 -- class-wide matching is not allowed.
690 if Is_Class_Wide_Type
(T
)
691 and then Base_Type
(Etype
(Nam
)) /= Base_Type
(T
)
697 Set_Ekind
(Id
, E_Variable
);
698 Init_Size_Align
(Id
);
700 if T
= Any_Type
or else Etype
(Nam
) = Any_Type
then
703 -- Verify that the renamed entity is an object or a function call.
704 -- It may have been rewritten in several ways.
706 elsif Is_Object_Reference
(Nam
) then
707 if Comes_From_Source
(N
)
708 and then Is_Dependent_Component_Of_Mutable_Object
(Nam
)
711 ("illegal renaming of discriminant-dependent component", Nam
);
716 -- A static function call may have been folded into a literal
718 elsif Nkind
(Original_Node
(Nam
)) = N_Function_Call
720 -- When expansion is disabled, attribute reference is not
721 -- rewritten as function call. Otherwise it may be rewritten
722 -- as a conversion, so check original node.
724 or else (Nkind
(Original_Node
(Nam
)) = N_Attribute_Reference
725 and then Is_Function_Attribute_Name
726 (Attribute_Name
(Original_Node
(Nam
))))
728 -- Weird but legal, equivalent to renaming a function call.
730 or else (Is_Entity_Name
(Nam
)
731 and then Ekind
(Entity
(Nam
)) = E_Enumeration_Literal
)
733 or else (Nkind
(Nam
) = N_Type_Conversion
734 and then Is_Tagged_Type
(Entity
(Subtype_Mark
(Nam
))))
739 if Nkind
(Nam
) = N_Type_Conversion
then
741 ("renaming of conversion only allowed for tagged types", Nam
);
744 Error_Msg_N
("expect object name in renaming", Nam
);
751 if not Is_Variable
(Nam
) then
752 Set_Ekind
(Id
, E_Constant
);
753 Set_Never_Set_In_Source
(Id
, True);
754 Set_Is_True_Constant
(Id
, True);
757 Set_Renamed_Object
(Id
, Nam
);
758 end Analyze_Object_Renaming
;
760 ------------------------------
761 -- Analyze_Package_Renaming --
762 ------------------------------
764 procedure Analyze_Package_Renaming
(N
: Node_Id
) is
765 New_P
: constant Entity_Id
:= Defining_Entity
(N
);
770 if Name
(N
) = Error
then
774 -- Apply Text_IO kludge here, since we may be renaming one of
775 -- the children of Text_IO
777 Text_IO_Kludge
(Name
(N
));
779 if Current_Scope
/= Standard_Standard
then
780 Set_Is_Pure
(New_P
, Is_Pure
(Current_Scope
));
785 if Is_Entity_Name
(Name
(N
)) then
786 Old_P
:= Entity
(Name
(N
));
791 if Etype
(Old_P
) = Any_Type
then
793 ("expect package name in renaming", Name
(N
));
795 -- Ada0Y (AI-50217): Limited withed packages can not be renamed
797 elsif Ekind
(Old_P
) = E_Package
798 and then From_With_Type
(Old_P
)
801 ("limited withed package cannot be renamed", Name
(N
));
803 elsif Ekind
(Old_P
) /= E_Package
804 and then not (Ekind
(Old_P
) = E_Generic_Package
805 and then In_Open_Scopes
(Old_P
))
807 if Ekind
(Old_P
) = E_Generic_Package
then
809 ("generic package cannot be renamed as a package", Name
(N
));
811 Error_Msg_Sloc
:= Sloc
(Old_P
);
813 ("expect package name in renaming, found& declared#",
817 -- Set basic attributes to minimize cascaded errors.
819 Set_Ekind
(New_P
, E_Package
);
820 Set_Etype
(New_P
, Standard_Void_Type
);
823 -- Entities in the old package are accessible through the
824 -- renaming entity. The simplest implementation is to have
825 -- both packages share the entity list.
827 Set_Ekind
(New_P
, E_Package
);
828 Set_Etype
(New_P
, Standard_Void_Type
);
830 if Present
(Renamed_Object
(Old_P
)) then
831 Set_Renamed_Object
(New_P
, Renamed_Object
(Old_P
));
833 Set_Renamed_Object
(New_P
, Old_P
);
836 Set_Has_Completion
(New_P
);
838 Set_First_Entity
(New_P
, First_Entity
(Old_P
));
839 Set_Last_Entity
(New_P
, Last_Entity
(Old_P
));
840 Set_First_Private_Entity
(New_P
, First_Private_Entity
(Old_P
));
841 Check_Library_Unit_Renaming
(N
, Old_P
);
842 Generate_Reference
(Old_P
, Name
(N
));
844 -- If this is the renaming declaration of a package instantiation
845 -- within itself, it is the declaration that ends the list of actuals
846 -- for the instantiation. At this point, the subtypes that rename
847 -- the actuals are flagged as generic, to avoid spurious ambiguities
848 -- if the actuals for two distinct formals happen to coincide. If
849 -- the actual is a private type, the subtype has a private completion
850 -- that is flagged in the same fashion.
852 -- Resolution is identical to what is was in the original generic.
853 -- On exit from the generic instance, these are turned into regular
854 -- subtypes again, so they are compatible with types in their class.
856 if not Is_Generic_Instance
(Old_P
) then
859 Spec
:= Specification
(Unit_Declaration_Node
(Old_P
));
862 if Nkind
(Spec
) = N_Package_Specification
863 and then Present
(Generic_Parent
(Spec
))
864 and then Old_P
= Current_Scope
865 and then Chars
(New_P
) = Chars
(Generic_Parent
(Spec
))
868 E
: Entity_Id
:= First_Entity
(Old_P
);
874 and then Nkind
(Parent
(E
)) = N_Subtype_Declaration
876 Set_Is_Generic_Actual_Type
(E
);
878 if Is_Private_Type
(E
)
879 and then Present
(Full_View
(E
))
881 Set_Is_Generic_Actual_Type
(Full_View
(E
));
891 end Analyze_Package_Renaming
;
893 -------------------------------
894 -- Analyze_Renamed_Character --
895 -------------------------------
897 procedure Analyze_Renamed_Character
902 C
: constant Node_Id
:= Name
(N
);
905 if Ekind
(New_S
) = E_Function
then
906 Resolve
(C
, Etype
(New_S
));
909 Check_Frozen_Renaming
(N
, New_S
);
913 Error_Msg_N
("character literal can only be renamed as function", N
);
915 end Analyze_Renamed_Character
;
917 ---------------------------------
918 -- Analyze_Renamed_Dereference --
919 ---------------------------------
921 procedure Analyze_Renamed_Dereference
926 Nam
: constant Node_Id
:= Name
(N
);
927 P
: constant Node_Id
:= Prefix
(Nam
);
933 if not Is_Overloaded
(P
) then
934 if Ekind
(Etype
(Nam
)) /= E_Subprogram_Type
935 or else not Type_Conformant
(Etype
(Nam
), New_S
) then
936 Error_Msg_N
("designated type does not match specification", P
);
945 Get_First_Interp
(Nam
, Ind
, It
);
947 while Present
(It
.Nam
) loop
949 if Ekind
(It
.Nam
) = E_Subprogram_Type
950 and then Type_Conformant
(It
.Nam
, New_S
) then
952 if Typ
/= Any_Id
then
953 Error_Msg_N
("ambiguous renaming", P
);
960 Get_Next_Interp
(Ind
, It
);
963 if Typ
= Any_Type
then
964 Error_Msg_N
("designated type does not match specification", P
);
969 Check_Frozen_Renaming
(N
, New_S
);
973 end Analyze_Renamed_Dereference
;
975 ---------------------------
976 -- Analyze_Renamed_Entry --
977 ---------------------------
979 procedure Analyze_Renamed_Entry
984 Nam
: constant Node_Id
:= Name
(N
);
985 Sel
: constant Node_Id
:= Selector_Name
(Nam
);
989 if Entity
(Sel
) = Any_Id
then
991 -- Selector is undefined on prefix. Error emitted already.
993 Set_Has_Completion
(New_S
);
997 -- Otherwise, find renamed entity, and build body of New_S as a call
1000 Old_S
:= Find_Renamed_Entity
(N
, Selector_Name
(Nam
), New_S
);
1002 if Old_S
= Any_Id
then
1003 Error_Msg_N
(" no subprogram or entry matches specification", N
);
1006 Check_Subtype_Conformant
(New_S
, Old_S
, N
);
1007 Generate_Reference
(New_S
, Defining_Entity
(N
), 'b');
1008 Style
.Check_Identifier
(Defining_Entity
(N
), New_S
);
1011 Inherit_Renamed_Profile
(New_S
, Old_S
);
1014 Set_Convention
(New_S
, Convention
(Old_S
));
1015 Set_Has_Completion
(New_S
, Inside_A_Generic
);
1018 Check_Frozen_Renaming
(N
, New_S
);
1020 end Analyze_Renamed_Entry
;
1022 -----------------------------------
1023 -- Analyze_Renamed_Family_Member --
1024 -----------------------------------
1026 procedure Analyze_Renamed_Family_Member
1031 Nam
: constant Node_Id
:= Name
(N
);
1032 P
: constant Node_Id
:= Prefix
(Nam
);
1036 if (Is_Entity_Name
(P
) and then Ekind
(Entity
(P
)) = E_Entry_Family
)
1037 or else (Nkind
(P
) = N_Selected_Component
1039 Ekind
(Entity
(Selector_Name
(P
))) = E_Entry_Family
)
1041 if Is_Entity_Name
(P
) then
1042 Old_S
:= Entity
(P
);
1044 Old_S
:= Entity
(Selector_Name
(P
));
1047 if not Entity_Matches_Spec
(Old_S
, New_S
) then
1048 Error_Msg_N
("entry family does not match specification", N
);
1051 Check_Subtype_Conformant
(New_S
, Old_S
, N
);
1052 Generate_Reference
(New_S
, Defining_Entity
(N
), 'b');
1053 Style
.Check_Identifier
(Defining_Entity
(N
), New_S
);
1056 Error_Msg_N
("no entry family matches specification", N
);
1059 Set_Has_Completion
(New_S
, Inside_A_Generic
);
1062 Check_Frozen_Renaming
(N
, New_S
);
1064 end Analyze_Renamed_Family_Member
;
1066 ---------------------------------
1067 -- Analyze_Subprogram_Renaming --
1068 ---------------------------------
1070 procedure Analyze_Subprogram_Renaming
(N
: Node_Id
) is
1071 Spec
: constant Node_Id
:= Specification
(N
);
1072 Save_83
: constant Boolean := Ada_83
;
1073 Nam
: constant Node_Id
:= Name
(N
);
1075 Old_S
: Entity_Id
:= Empty
;
1076 Rename_Spec
: Entity_Id
;
1077 Is_Actual
: Boolean := False;
1078 Inst_Node
: Node_Id
:= Empty
;
1080 function Original_Subprogram
(Subp
: Entity_Id
) return Entity_Id
;
1081 -- Find renamed entity when the declaration is a renaming_as_body
1082 -- and the renamed entity may itself be a renaming_as_body. Used to
1083 -- enforce rule that a renaming_as_body is illegal if the declaration
1084 -- occurs before the subprogram it completes is frozen, and renaming
1085 -- indirectly renames the subprogram itself.(Defect Report 8652/0027).
1087 -------------------------
1088 -- Original_Subprogram --
1089 -------------------------
1091 function Original_Subprogram
(Subp
: Entity_Id
) return Entity_Id
is
1092 Orig_Decl
: Node_Id
;
1093 Orig_Subp
: Entity_Id
;
1096 -- First case: renamed entity is itself a renaming
1098 if Present
(Alias
(Subp
)) then
1099 return Alias
(Subp
);
1102 Nkind
(Unit_Declaration_Node
(Subp
)) = N_Subprogram_Declaration
1104 (Corresponding_Body
(Unit_Declaration_Node
(Subp
)))
1106 -- Check if renamed entity is a renaming_as_body
1109 Unit_Declaration_Node
1110 (Corresponding_Body
(Unit_Declaration_Node
(Subp
)));
1112 if Nkind
(Orig_Decl
) = N_Subprogram_Renaming_Declaration
then
1113 Orig_Subp
:= Entity
(Name
(Orig_Decl
));
1115 if Orig_Subp
= Rename_Spec
then
1117 -- Circularity detected.
1122 return (Original_Subprogram
(Orig_Subp
));
1130 end Original_Subprogram
;
1132 -- Start of processing for Analyze_Subprogram_Renaming
1135 -- We must test for the attribute renaming case before the Analyze
1136 -- call because otherwise Sem_Attr will complain that the attribute
1137 -- is missing an argument when it is analyzed.
1139 if Nkind
(Nam
) = N_Attribute_Reference
then
1140 Attribute_Renaming
(N
);
1144 -- Check whether this declaration corresponds to the instantiation
1145 -- of a formal subprogram. This is indicated by the presence of a
1146 -- Corresponding_Spec that is the instantiation declaration.
1148 -- If this is an instantiation, the corresponding actual is frozen
1149 -- and error messages can be made more precise. If this is a default
1150 -- subprogram, the entity is already established in the generic, and
1151 -- is not retrieved by visibility. If it is a default with a box, the
1152 -- candidate interpretations, if any, have been collected when building
1153 -- the renaming declaration. If overloaded, the proper interpretation
1154 -- is determined in Find_Renamed_Entity. If the entity is an operator,
1155 -- Find_Renamed_Entity applies additional visibility checks.
1157 if Present
(Corresponding_Spec
(N
)) then
1159 Inst_Node
:= Unit_Declaration_Node
(Corresponding_Spec
(N
));
1161 if Is_Entity_Name
(Nam
)
1162 and then Present
(Entity
(Nam
))
1163 and then not Comes_From_Source
(Nam
)
1164 and then not Is_Overloaded
(Nam
)
1166 Old_S
:= Entity
(Nam
);
1167 New_S
:= Analyze_Subprogram_Specification
(Spec
);
1169 if Ekind
(Entity
(Nam
)) = E_Operator
1170 and then Box_Present
(Inst_Node
)
1172 Old_S
:= Find_Renamed_Entity
(N
, Name
(N
), New_S
, Is_Actual
);
1177 New_S
:= Analyze_Subprogram_Specification
(Spec
);
1180 Set_Corresponding_Spec
(N
, Empty
);
1183 -- Renamed entity must be analyzed first, to avoid being hidden by
1184 -- new name (which might be the same in a generic instance).
1188 -- The renaming defines a new overloaded entity, which is analyzed
1189 -- like a subprogram declaration.
1191 New_S
:= Analyze_Subprogram_Specification
(Spec
);
1194 if Current_Scope
/= Standard_Standard
then
1195 Set_Is_Pure
(New_S
, Is_Pure
(Current_Scope
));
1198 Rename_Spec
:= Find_Corresponding_Spec
(N
);
1200 if Present
(Rename_Spec
) then
1202 -- Renaming_As_Body. Renaming declaration is the completion of
1203 -- the declaration of Rename_Spec. We will build an actual body
1204 -- for it at the freezing point.
1206 Set_Corresponding_Spec
(N
, Rename_Spec
);
1207 Set_Corresponding_Body
(Unit_Declaration_Node
(Rename_Spec
), New_S
);
1209 -- The body is created when the entity is frozen. If the context
1210 -- is generic, freeze_all is not invoked, so we need to indicate
1211 -- that the entity has a completion.
1213 Set_Has_Completion
(Rename_Spec
, Inside_A_Generic
);
1215 if Ada_83
and then Comes_From_Source
(N
) then
1216 Error_Msg_N
("(Ada 83) renaming cannot serve as a body", N
);
1219 Set_Convention
(New_S
, Convention
(Rename_Spec
));
1220 Check_Fully_Conformant
(New_S
, Rename_Spec
);
1221 Set_Public_Status
(New_S
);
1223 -- Indicate that the entity in the declaration functions like
1224 -- the corresponding body, and is not a new entity.
1226 Set_Ekind
(New_S
, E_Subprogram_Body
);
1227 New_S
:= Rename_Spec
;
1230 Generate_Definition
(New_S
);
1231 New_Overloaded_Entity
(New_S
);
1232 if Is_Entity_Name
(Nam
)
1233 and then Is_Intrinsic_Subprogram
(Entity
(Nam
))
1237 Check_Delayed_Subprogram
(New_S
);
1241 -- There is no need for elaboration checks on the new entity, which
1242 -- may be called before the next freezing point where the body will
1245 Set_Kill_Elaboration_Checks
(New_S
, True);
1247 if Etype
(Nam
) = Any_Type
then
1248 Set_Has_Completion
(New_S
);
1251 elsif Nkind
(Nam
) = N_Selected_Component
then
1253 -- Renamed entity is an entry or protected subprogram. For those
1254 -- cases an explicit body is built (at the point of freezing of
1255 -- this entity) that contains a call to the renamed entity.
1257 Analyze_Renamed_Entry
(N
, New_S
, Present
(Rename_Spec
));
1260 elsif Nkind
(Nam
) = N_Explicit_Dereference
then
1262 -- Renamed entity is designated by access_to_subprogram expression.
1263 -- Must build body to encapsulate call, as in the entry case.
1265 Analyze_Renamed_Dereference
(N
, New_S
, Present
(Rename_Spec
));
1268 elsif Nkind
(Nam
) = N_Indexed_Component
then
1269 Analyze_Renamed_Family_Member
(N
, New_S
, Present
(Rename_Spec
));
1272 elsif Nkind
(Nam
) = N_Character_Literal
then
1273 Analyze_Renamed_Character
(N
, New_S
, Present
(Rename_Spec
));
1276 elsif (not Is_Entity_Name
(Nam
)
1277 and then Nkind
(Nam
) /= N_Operator_Symbol
)
1278 or else not Is_Overloadable
(Entity
(Nam
))
1280 Error_Msg_N
("expect valid subprogram name in renaming", N
);
1285 -- Most common case: subprogram renames subprogram. No body is
1286 -- generated in this case, so we must indicate that the declaration
1287 -- is complete as is.
1289 if No
(Rename_Spec
) then
1290 Set_Has_Completion
(New_S
);
1293 -- Find the renamed entity that matches the given specification.
1294 -- Disable Ada_83 because there is no requirement of full conformance
1295 -- between renamed entity and new entity, even though the same circuit
1301 Old_S
:= Find_Renamed_Entity
(N
, Name
(N
), New_S
, Is_Actual
);
1304 if Old_S
/= Any_Id
then
1307 and then Box_Present
(Inst_Node
)
1309 -- This is an implicit reference to the default actual
1311 Generate_Reference
(Old_S
, Nam
, Typ
=> 'i', Force
=> True);
1313 Generate_Reference
(Old_S
, Nam
);
1316 -- For a renaming-as-body, require subtype conformance,
1317 -- but if the declaration being completed has not been
1318 -- frozen, then inherit the convention of the renamed
1319 -- subprogram prior to checking conformance (unless the
1320 -- renaming has an explicit convention established; the
1321 -- rule stated in the RM doesn't seem to address this ???).
1323 if Present
(Rename_Spec
) then
1324 Generate_Reference
(Rename_Spec
, Defining_Entity
(Spec
), 'b');
1325 Style
.Check_Identifier
(Defining_Entity
(Spec
), Rename_Spec
);
1327 if not Is_Frozen
(Rename_Spec
) then
1328 if not Has_Convention_Pragma
(Rename_Spec
) then
1329 Set_Convention
(New_S
, Convention
(Old_S
));
1332 if Ekind
(Old_S
) /= E_Operator
then
1333 Check_Mode_Conformant
(New_S
, Old_S
, Spec
);
1336 if Original_Subprogram
(Old_S
) = Rename_Spec
then
1337 Error_Msg_N
("unfrozen subprogram cannot rename itself ", N
);
1340 Check_Subtype_Conformant
(New_S
, Old_S
, Spec
);
1343 Check_Frozen_Renaming
(N
, Rename_Spec
);
1345 elsif Ekind
(Old_S
) /= E_Operator
then
1346 Check_Mode_Conformant
(New_S
, Old_S
);
1349 and then Error_Posted
(New_S
)
1351 Error_Msg_NE
("invalid actual subprogram: & #!", N
, Old_S
);
1355 if No
(Rename_Spec
) then
1357 -- The parameter profile of the new entity is that of the renamed
1358 -- entity: the subtypes given in the specification are irrelevant.
1360 Inherit_Renamed_Profile
(New_S
, Old_S
);
1362 -- A call to the subprogram is transformed into a call to the
1363 -- renamed entity. This is transitive if the renamed entity is
1364 -- itself a renaming.
1366 if Present
(Alias
(Old_S
)) then
1367 Set_Alias
(New_S
, Alias
(Old_S
));
1369 Set_Alias
(New_S
, Old_S
);
1372 -- Note that we do not set Is_Instrinsic_Subprogram if we have
1373 -- a renaming as body, since the entity in this case is not an
1374 -- intrinsic (it calls an intrinsic, but we have a real body
1375 -- for this call, and it is in this body that the required
1376 -- intrinsic processing will take place).
1378 -- Also, if this is a renaming of inequality, the renamed
1379 -- operator is intrinsic, but what matters is the corresponding
1380 -- equality operator, which may be user-defined.
1382 Set_Is_Intrinsic_Subprogram
1384 Is_Intrinsic_Subprogram
(Old_S
)
1386 (Chars
(Old_S
) /= Name_Op_Ne
1387 or else Ekind
(Old_S
) = E_Operator
1389 Is_Intrinsic_Subprogram
1390 (Corresponding_Equality
(Old_S
))));
1392 if Ekind
(Alias
(New_S
)) = E_Operator
then
1393 Set_Has_Delayed_Freeze
(New_S
, False);
1399 and then (Old_S
= New_S
1400 or else (Nkind
(Nam
) /= N_Expanded_Name
1401 and then Chars
(Old_S
) = Chars
(New_S
)))
1403 Error_Msg_N
("subprogram cannot rename itself", N
);
1406 Set_Convention
(New_S
, Convention
(Old_S
));
1407 Set_Is_Abstract
(New_S
, Is_Abstract
(Old_S
));
1408 Check_Library_Unit_Renaming
(N
, Old_S
);
1410 -- Pathological case: procedure renames entry in the scope of
1411 -- its task. Entry is given by simple name, but body must be built
1412 -- for procedure. Of course if called it will deadlock.
1414 if Ekind
(Old_S
) = E_Entry
then
1415 Set_Has_Completion
(New_S
, False);
1416 Set_Alias
(New_S
, Empty
);
1420 Freeze_Before
(N
, Old_S
);
1421 Set_Has_Delayed_Freeze
(New_S
, False);
1422 Freeze_Before
(N
, New_S
);
1424 if (Ekind
(Old_S
) = E_Procedure
or else Ekind
(Old_S
) = E_Function
)
1425 and then Is_Abstract
(Old_S
)
1428 ("abstract subprogram not allowed as generic actual", Nam
);
1433 -- A common error is to assume that implicit operators for types
1434 -- are defined in Standard, or in the scope of a subtype. In those
1435 -- cases where the renamed entity is given with an expanded name,
1436 -- it is worth mentioning that operators for the type are not
1437 -- declared in the scope given by the prefix.
1439 if Nkind
(Nam
) = N_Expanded_Name
1440 and then Nkind
(Selector_Name
(Nam
)) = N_Operator_Symbol
1441 and then Scope
(Entity
(Nam
)) = Standard_Standard
1444 T
: constant Entity_Id
:=
1445 Base_Type
(Etype
(First_Formal
(New_S
)));
1448 Error_Msg_Node_2
:= Prefix
(Nam
);
1450 ("operator for type& is not declared in&", Prefix
(Nam
), T
);
1455 ("no visible subprogram matches the specification for&",
1459 if Present
(Candidate_Renaming
) then
1465 F1
:= First_Formal
(Candidate_Renaming
);
1466 F2
:= First_Formal
(New_S
);
1468 while Present
(F1
) and then Present
(F2
) loop
1473 if Present
(F1
) and then Present
(Default_Value
(F1
)) then
1474 if Present
(Next_Formal
(F1
)) then
1476 ("\missing specification for &" &
1477 " and other formals with defaults", Spec
, F1
);
1480 ("\missing specification for &", Spec
, F1
);
1488 end Analyze_Subprogram_Renaming
;
1490 -------------------------
1491 -- Analyze_Use_Package --
1492 -------------------------
1494 -- Resolve the package names in the use clause, and make all the visible
1495 -- entities defined in the package potentially use-visible. If the package
1496 -- is already in use from a previous use clause, its visible entities are
1497 -- already use-visible. In that case, mark the occurrence as a redundant
1498 -- use. If the package is an open scope, i.e. if the use clause occurs
1499 -- within the package itself, ignore it.
1501 procedure Analyze_Use_Package
(N
: Node_Id
) is
1502 Pack_Name
: Node_Id
;
1505 -- Start of processing for Analyze_Use_Package
1508 Set_Hidden_By_Use_Clause
(N
, No_Elist
);
1510 -- Use clause is not allowed in a spec of a predefined package
1511 -- declaration except that packages whose file name starts a-n
1512 -- are OK (these are children of Ada.Numerics, and such packages
1513 -- are never loaded by Rtsfind).
1515 if Is_Predefined_File_Name
(Unit_File_Name
(Current_Sem_Unit
))
1516 and then Name_Buffer
(1 .. 3) /= "a-n"
1518 Nkind
(Unit
(Cunit
(Current_Sem_Unit
))) = N_Package_Declaration
1520 Error_Msg_N
("use clause not allowed in predefined spec", N
);
1523 -- Chain clause to list of use clauses in current scope.
1525 if Nkind
(Parent
(N
)) /= N_Compilation_Unit
then
1526 Chain_Use_Clause
(N
);
1529 -- Loop through package names to identify referenced packages
1531 Pack_Name
:= First
(Names
(N
));
1533 while Present
(Pack_Name
) loop
1534 Analyze
(Pack_Name
);
1536 if Nkind
(Parent
(N
)) = N_Compilation_Unit
1537 and then Nkind
(Pack_Name
) = N_Expanded_Name
1540 Pref
: Node_Id
:= Prefix
(Pack_Name
);
1543 while Nkind
(Pref
) = N_Expanded_Name
loop
1544 Pref
:= Prefix
(Pref
);
1547 if Entity
(Pref
) = Standard_Standard
then
1549 ("predefined package Standard cannot appear"
1550 & " in a context clause", Pref
);
1558 -- Loop through package names to mark all entities as potentially
1561 Pack_Name
:= First
(Names
(N
));
1563 while Present
(Pack_Name
) loop
1565 if Is_Entity_Name
(Pack_Name
) then
1566 Pack
:= Entity
(Pack_Name
);
1568 if Ekind
(Pack
) /= E_Package
1569 and then Etype
(Pack
) /= Any_Type
1571 if Ekind
(Pack
) = E_Generic_Package
then
1573 ("a generic package is not allowed in a use clause",
1576 Error_Msg_N
("& is not a usable package", Pack_Name
);
1580 if Nkind
(Parent
(N
)) = N_Compilation_Unit
then
1581 Check_In_Previous_With_Clause
(N
, Pack_Name
);
1584 if Applicable_Use
(Pack_Name
) then
1585 Use_One_Package
(Pack
, N
);
1593 end Analyze_Use_Package
;
1595 ----------------------
1596 -- Analyze_Use_Type --
1597 ----------------------
1599 procedure Analyze_Use_Type
(N
: Node_Id
) is
1603 Set_Hidden_By_Use_Clause
(N
, No_Elist
);
1605 -- Chain clause to list of use clauses in current scope.
1607 if Nkind
(Parent
(N
)) /= N_Compilation_Unit
then
1608 Chain_Use_Clause
(N
);
1611 Id
:= First
(Subtype_Marks
(N
));
1613 while Present
(Id
) loop
1616 if Entity
(Id
) /= Any_Type
then
1619 if Nkind
(Parent
(N
)) = N_Compilation_Unit
then
1620 if Nkind
(Id
) = N_Identifier
then
1621 Error_Msg_N
("Type is not directly visible", Id
);
1623 elsif Is_Child_Unit
(Scope
(Entity
(Id
)))
1624 and then Scope
(Entity
(Id
)) /= System_Aux_Id
1626 Check_In_Previous_With_Clause
(N
, Prefix
(Id
));
1633 end Analyze_Use_Type
;
1635 --------------------
1636 -- Applicable_Use --
1637 --------------------
1639 function Applicable_Use
(Pack_Name
: Node_Id
) return Boolean is
1640 Pack
: constant Entity_Id
:= Entity
(Pack_Name
);
1643 if In_Open_Scopes
(Pack
) then
1646 elsif In_Use
(Pack
) then
1647 Set_Redundant_Use
(Pack_Name
, True);
1650 elsif Present
(Renamed_Object
(Pack
))
1651 and then In_Use
(Renamed_Object
(Pack
))
1653 Set_Redundant_Use
(Pack_Name
, True);
1661 ------------------------
1662 -- Attribute_Renaming --
1663 ------------------------
1665 procedure Attribute_Renaming
(N
: Node_Id
) is
1666 Loc
: constant Source_Ptr
:= Sloc
(N
);
1667 Nam
: constant Node_Id
:= Name
(N
);
1668 Spec
: constant Node_Id
:= Specification
(N
);
1669 New_S
: constant Entity_Id
:= Defining_Unit_Name
(Spec
);
1670 Aname
: constant Name_Id
:= Attribute_Name
(Nam
);
1672 Form_Num
: Nat
:= 0;
1673 Expr_List
: List_Id
:= No_List
;
1675 Attr_Node
: Node_Id
;
1676 Body_Node
: Node_Id
;
1677 Param_Spec
: Node_Id
;
1680 Generate_Definition
(New_S
);
1682 -- This procedure is called in the context of subprogram renaming,
1683 -- and thus the attribute must be one that is a subprogram. All of
1684 -- those have at least one formal parameter, with the singular
1685 -- exception of AST_Entry (which is a real oddity, it is odd that
1686 -- this can be renamed at all!)
1688 if not Is_Non_Empty_List
(Parameter_Specifications
(Spec
)) then
1689 if Aname
/= Name_AST_Entry
then
1691 ("subprogram renaming an attribute must have formals", N
);
1696 Param_Spec
:= First
(Parameter_Specifications
(Spec
));
1698 while Present
(Param_Spec
) loop
1699 Form_Num
:= Form_Num
+ 1;
1701 if Nkind
(Parameter_Type
(Param_Spec
)) /= N_Access_Definition
then
1702 Find_Type
(Parameter_Type
(Param_Spec
));
1704 -- The profile of the new entity denotes the base type (s) of
1705 -- the types given in the specification. For access parameters
1706 -- there are no subtypes involved.
1708 Rewrite
(Parameter_Type
(Param_Spec
),
1710 (Base_Type
(Entity
(Parameter_Type
(Param_Spec
))), Loc
));
1713 if No
(Expr_List
) then
1714 Expr_List
:= New_List
;
1717 Append_To
(Expr_List
,
1718 Make_Identifier
(Loc
,
1719 Chars
=> Chars
(Defining_Identifier
(Param_Spec
))));
1721 -- The expressions in the attribute reference are not freeze
1722 -- points. Neither is the attribute as a whole, see below.
1724 Set_Must_Not_Freeze
(Last
(Expr_List
));
1729 -- Immediate error if too many formals. Other mismatches in numbers
1730 -- of number of types of parameters are detected when we analyze the
1731 -- body of the subprogram that we construct.
1733 if Form_Num
> 2 then
1734 Error_Msg_N
("too many formals for attribute", N
);
1737 Aname
= Name_Compose
or else
1738 Aname
= Name_Exponent
or else
1739 Aname
= Name_Leading_Part
or else
1740 Aname
= Name_Pos
or else
1741 Aname
= Name_Round
or else
1742 Aname
= Name_Scaling
or else
1745 if Nkind
(N
) = N_Subprogram_Renaming_Declaration
1746 and then Present
(Corresponding_Spec
(N
))
1747 and then Nkind
(Unit_Declaration_Node
(Corresponding_Spec
(N
))) =
1748 N_Formal_Subprogram_Declaration
1751 ("generic actual cannot be attribute involving universal type",
1755 ("attribute involving a universal type cannot be renamed",
1760 -- AST_Entry is an odd case. It doesn't really make much sense to
1761 -- allow it to be renamed, but that's the DEC rule, so we have to
1762 -- do it right. The point is that the AST_Entry call should be made
1763 -- now, and what the function will return is the returned value.
1765 -- Note that there is no Expr_List in this case anyway
1767 if Aname
= Name_AST_Entry
then
1774 Ent
:= Make_Defining_Identifier
(Loc
, New_Internal_Name
('R'));
1777 Make_Object_Declaration
(Loc
,
1778 Defining_Identifier
=> Ent
,
1779 Object_Definition
=>
1780 New_Occurrence_Of
(RTE
(RE_AST_Handler
), Loc
),
1782 Constant_Present
=> True);
1784 Set_Assignment_OK
(Decl
, True);
1785 Insert_Action
(N
, Decl
);
1786 Attr_Node
:= Make_Identifier
(Loc
, Chars
(Ent
));
1789 -- For all other attributes, we rewrite the attribute node to have
1790 -- a list of expressions corresponding to the subprogram formals.
1791 -- A renaming declaration is not a freeze point, and the analysis of
1792 -- the attribute reference should not freeze the type of the prefix.
1796 Make_Attribute_Reference
(Loc
,
1797 Prefix
=> Prefix
(Nam
),
1798 Attribute_Name
=> Aname
,
1799 Expressions
=> Expr_List
);
1801 Set_Must_Not_Freeze
(Attr_Node
);
1802 Set_Must_Not_Freeze
(Prefix
(Nam
));
1805 -- Case of renaming a function
1807 if Nkind
(Spec
) = N_Function_Specification
then
1809 if Is_Procedure_Attribute_Name
(Aname
) then
1810 Error_Msg_N
("attribute can only be renamed as procedure", Nam
);
1814 Find_Type
(Subtype_Mark
(Spec
));
1815 Rewrite
(Subtype_Mark
(Spec
),
1816 New_Reference_To
(Base_Type
(Entity
(Subtype_Mark
(Spec
))), Loc
));
1819 Make_Subprogram_Body
(Loc
,
1820 Specification
=> Spec
,
1821 Declarations
=> New_List
,
1822 Handled_Statement_Sequence
=>
1823 Make_Handled_Sequence_Of_Statements
(Loc
,
1824 Statements
=> New_List
(
1825 Make_Return_Statement
(Loc
,
1826 Expression
=> Attr_Node
))));
1828 -- Case of renaming a procedure
1831 if not Is_Procedure_Attribute_Name
(Aname
) then
1832 Error_Msg_N
("attribute can only be renamed as function", Nam
);
1837 Make_Subprogram_Body
(Loc
,
1838 Specification
=> Spec
,
1839 Declarations
=> New_List
,
1840 Handled_Statement_Sequence
=>
1841 Make_Handled_Sequence_Of_Statements
(Loc
,
1842 Statements
=> New_List
(Attr_Node
)));
1845 Rewrite
(N
, Body_Node
);
1848 Set_Etype
(New_S
, Base_Type
(Etype
(New_S
)));
1850 -- We suppress elaboration warnings for the resulting entity, since
1851 -- clearly they are not needed, and more particularly, in the case
1852 -- of a generic formal subprogram, the resulting entity can appear
1853 -- after the instantiation itself, and thus look like a bogus case
1854 -- of access before elaboration.
1856 Set_Suppress_Elaboration_Warnings
(New_S
);
1858 end Attribute_Renaming
;
1860 ----------------------
1861 -- Chain_Use_Clause --
1862 ----------------------
1864 procedure Chain_Use_Clause
(N
: Node_Id
) is
1866 Set_Next_Use_Clause
(N
,
1867 Scope_Stack
.Table
(Scope_Stack
.Last
).First_Use_Clause
);
1868 Scope_Stack
.Table
(Scope_Stack
.Last
).First_Use_Clause
:= N
;
1869 end Chain_Use_Clause
;
1871 ----------------------------
1872 -- Check_Frozen_Renaming --
1873 ----------------------------
1875 procedure Check_Frozen_Renaming
(N
: Node_Id
; Subp
: Entity_Id
) is
1881 and then not Has_Completion
(Subp
)
1885 (Parent
(Declaration_Node
(Subp
)), Defining_Entity
(N
));
1887 if Is_Entity_Name
(Name
(N
)) then
1888 Old_S
:= Entity
(Name
(N
));
1890 if not Is_Frozen
(Old_S
)
1891 and then Operating_Mode
/= Check_Semantics
1893 Append_Freeze_Action
(Old_S
, B_Node
);
1895 Insert_After
(N
, B_Node
);
1899 if Is_Intrinsic_Subprogram
(Old_S
)
1900 and then not In_Instance
1903 ("subprogram used in renaming_as_body cannot be intrinsic",
1908 Insert_After
(N
, B_Node
);
1912 end Check_Frozen_Renaming
;
1914 -----------------------------------
1915 -- Check_In_Previous_With_Clause --
1916 -----------------------------------
1918 procedure Check_In_Previous_With_Clause
1922 Pack
: constant Entity_Id
:= Entity
(Original_Node
(Nam
));
1927 Item
:= First
(Context_Items
(Parent
(N
)));
1929 while Present
(Item
)
1932 if Nkind
(Item
) = N_With_Clause
1933 and then Entity
(Name
(Item
)) = Pack
1937 -- Find root library unit in with_clause.
1939 while Nkind
(Par
) = N_Expanded_Name
loop
1940 Par
:= Prefix
(Par
);
1943 if Is_Child_Unit
(Entity
(Original_Node
(Par
))) then
1945 ("& is not directly visible", Par
, Entity
(Par
));
1954 -- On exit, package is not mentioned in a previous with_clause.
1955 -- Check if its prefix is.
1957 if Nkind
(Nam
) = N_Expanded_Name
then
1958 Check_In_Previous_With_Clause
(N
, Prefix
(Nam
));
1960 elsif Pack
/= Any_Id
then
1961 Error_Msg_NE
("& is not visible", Nam
, Pack
);
1963 end Check_In_Previous_With_Clause
;
1965 ---------------------------------
1966 -- Check_Library_Unit_Renaming --
1967 ---------------------------------
1969 procedure Check_Library_Unit_Renaming
(N
: Node_Id
; Old_E
: Entity_Id
) is
1973 if Nkind
(Parent
(N
)) /= N_Compilation_Unit
then
1976 elsif Scope
(Old_E
) /= Standard_Standard
1977 and then not Is_Child_Unit
(Old_E
)
1979 Error_Msg_N
("renamed unit must be a library unit", Name
(N
));
1981 elsif Present
(Parent_Spec
(N
))
1982 and then Nkind
(Unit
(Parent_Spec
(N
))) = N_Generic_Package_Declaration
1983 and then not Is_Child_Unit
(Old_E
)
1986 ("renamed unit must be a child unit of generic parent", Name
(N
));
1988 elsif Nkind
(N
) in N_Generic_Renaming_Declaration
1989 and then Nkind
(Name
(N
)) = N_Expanded_Name
1990 and then Is_Generic_Instance
(Entity
(Prefix
(Name
(N
))))
1991 and then Is_Generic_Unit
(Old_E
)
1994 ("renamed generic unit must be a library unit", Name
(N
));
1996 elsif Ekind
(Old_E
) = E_Package
1997 or else Ekind
(Old_E
) = E_Generic_Package
1999 -- Inherit categorization flags
2001 New_E
:= Defining_Entity
(N
);
2002 Set_Is_Pure
(New_E
, Is_Pure
(Old_E
));
2003 Set_Is_Preelaborated
(New_E
, Is_Preelaborated
(Old_E
));
2004 Set_Is_Remote_Call_Interface
(New_E
,
2005 Is_Remote_Call_Interface
(Old_E
));
2006 Set_Is_Remote_Types
(New_E
, Is_Remote_Types
(Old_E
));
2007 Set_Is_Shared_Passive
(New_E
, Is_Shared_Passive
(Old_E
));
2009 end Check_Library_Unit_Renaming
;
2015 procedure End_Scope
is
2021 Id
:= First_Entity
(Current_Scope
);
2023 while Present
(Id
) loop
2024 -- An entity in the current scope is not necessarily the first one
2025 -- on its homonym chain. Find its predecessor if any,
2026 -- If it is an internal entity, it will not be in the visibility
2027 -- chain altogether, and there is nothing to unchain.
2029 if Id
/= Current_Entity
(Id
) then
2030 Prev
:= Current_Entity
(Id
);
2031 while Present
(Prev
)
2032 and then Present
(Homonym
(Prev
))
2033 and then Homonym
(Prev
) /= Id
2035 Prev
:= Homonym
(Prev
);
2038 -- Skip to end of loop if Id is not in the visibility chain
2040 if No
(Prev
) or else Homonym
(Prev
) /= Id
then
2048 Outer
:= Homonym
(Id
);
2049 Set_Is_Immediately_Visible
(Id
, False);
2051 while Present
(Outer
) and then Scope
(Outer
) = Current_Scope
loop
2052 Outer
:= Homonym
(Outer
);
2055 -- Reset homonym link of other entities, but do not modify link
2056 -- between entities in current scope, so that the back-end can have
2057 -- a proper count of local overloadings.
2060 Set_Name_Entity_Id
(Chars
(Id
), Outer
);
2062 elsif Scope
(Prev
) /= Scope
(Id
) then
2063 Set_Homonym
(Prev
, Outer
);
2070 -- If the scope generated freeze actions, place them before the
2071 -- current declaration and analyze them. Type declarations and
2072 -- the bodies of initialization procedures can generate such nodes.
2073 -- We follow the parent chain until we reach a list node, which is
2074 -- the enclosing list of declarations. If the list appears within
2075 -- a protected definition, move freeze nodes outside the protected
2079 (Scope_Stack
.Table
(Scope_Stack
.Last
).Pending_Freeze_Actions
)
2083 L
: constant List_Id
:= Scope_Stack
.Table
2084 (Scope_Stack
.Last
).Pending_Freeze_Actions
;
2087 if Is_Itype
(Current_Scope
) then
2088 Decl
:= Associated_Node_For_Itype
(Current_Scope
);
2090 Decl
:= Parent
(Current_Scope
);
2095 while not (Is_List_Member
(Decl
))
2096 or else Nkind
(Parent
(Decl
)) = N_Protected_Definition
2097 or else Nkind
(Parent
(Decl
)) = N_Task_Definition
2099 Decl
:= Parent
(Decl
);
2102 Insert_List_Before_And_Analyze
(Decl
, L
);
2111 ---------------------
2112 -- End_Use_Clauses --
2113 ---------------------
2115 procedure End_Use_Clauses
(Clause
: Node_Id
) is
2119 -- Remove Use_Type clauses first, because they affect the
2120 -- visibility of operators in subsequent used packages.
2123 while Present
(U
) loop
2124 if Nkind
(U
) = N_Use_Type_Clause
then
2128 Next_Use_Clause
(U
);
2132 while Present
(U
) loop
2133 if Nkind
(U
) = N_Use_Package_Clause
then
2134 End_Use_Package
(U
);
2137 Next_Use_Clause
(U
);
2139 end End_Use_Clauses
;
2141 ---------------------
2142 -- End_Use_Package --
2143 ---------------------
2145 procedure End_Use_Package
(N
: Node_Id
) is
2146 Pack_Name
: Node_Id
;
2151 function Is_Primitive_Operator
2155 -- Check whether Op is a primitive operator of a use-visible type
2157 ---------------------------
2158 -- Is_Primitive_Operator --
2159 ---------------------------
2161 function Is_Primitive_Operator
2166 T
: constant Entity_Id
:= Etype
(F
);
2170 and then Scope
(T
) = Scope
(Op
);
2171 end Is_Primitive_Operator
;
2173 -- Start of processing for End_Use_Package
2176 Pack_Name
:= First
(Names
(N
));
2178 while Present
(Pack_Name
) loop
2179 Pack
:= Entity
(Pack_Name
);
2181 if Ekind
(Pack
) = E_Package
then
2183 if In_Open_Scopes
(Pack
) then
2186 elsif not Redundant_Use
(Pack_Name
) then
2187 Set_In_Use
(Pack
, False);
2188 Id
:= First_Entity
(Pack
);
2190 while Present
(Id
) loop
2192 -- Preserve use-visibility of operators that are primitive
2193 -- operators of a type that is use_visible through an active
2196 if Nkind
(Id
) = N_Defining_Operator_Symbol
2198 (Is_Primitive_Operator
(Id
, First_Formal
(Id
))
2200 (Present
(Next_Formal
(First_Formal
(Id
)))
2202 Is_Primitive_Operator
2203 (Id
, Next_Formal
(First_Formal
(Id
)))))
2208 Set_Is_Potentially_Use_Visible
(Id
, False);
2211 if Is_Private_Type
(Id
)
2212 and then Present
(Full_View
(Id
))
2214 Set_Is_Potentially_Use_Visible
(Full_View
(Id
), False);
2220 if Present
(Renamed_Object
(Pack
)) then
2221 Set_In_Use
(Renamed_Object
(Pack
), False);
2224 if Chars
(Pack
) = Name_System
2225 and then Scope
(Pack
) = Standard_Standard
2226 and then Present_System_Aux
2228 Id
:= First_Entity
(System_Aux_Id
);
2230 while Present
(Id
) loop
2231 Set_Is_Potentially_Use_Visible
(Id
, False);
2233 if Is_Private_Type
(Id
)
2234 and then Present
(Full_View
(Id
))
2236 Set_Is_Potentially_Use_Visible
(Full_View
(Id
), False);
2242 Set_In_Use
(System_Aux_Id
, False);
2246 Set_Redundant_Use
(Pack_Name
, False);
2254 if Present
(Hidden_By_Use_Clause
(N
)) then
2255 Elmt
:= First_Elmt
(Hidden_By_Use_Clause
(N
));
2257 while Present
(Elmt
) loop
2258 Set_Is_Immediately_Visible
(Node
(Elmt
));
2262 Set_Hidden_By_Use_Clause
(N
, No_Elist
);
2264 end End_Use_Package
;
2270 procedure End_Use_Type
(N
: Node_Id
) is
2277 Id
:= First
(Subtype_Marks
(N
));
2279 while Present
(Id
) loop
2281 -- A call to rtsfind may occur while analyzing a use_type clause,
2282 -- in which case the type marks are not resolved yet, and there is
2283 -- nothing to remove.
2285 if not Is_Entity_Name
(Id
)
2286 or else No
(Entity
(Id
))
2293 if T
= Any_Type
then
2296 -- Note that the use_Type clause may mention a subtype of the
2297 -- type whose primitive operations have been made visible. Here
2298 -- as elsewhere, it is the base type that matters for visibility.
2300 elsif In_Open_Scopes
(Scope
(Base_Type
(T
))) then
2303 elsif not Redundant_Use
(Id
) then
2304 Set_In_Use
(T
, False);
2305 Set_In_Use
(Base_Type
(T
), False);
2306 Op_List
:= Collect_Primitive_Operations
(T
);
2307 Elmt
:= First_Elmt
(Op_List
);
2309 while Present
(Elmt
) loop
2311 if Nkind
(Node
(Elmt
)) = N_Defining_Operator_Symbol
then
2312 Set_Is_Potentially_Use_Visible
(Node
(Elmt
), False);
2324 ----------------------
2325 -- Find_Direct_Name --
2326 ----------------------
2328 procedure Find_Direct_Name
(N
: Node_Id
) is
2333 Inst
: Entity_Id
:= Empty
;
2334 -- Enclosing instance, if any.
2336 Homonyms
: Entity_Id
;
2337 -- Saves start of homonym chain
2339 Nvis_Entity
: Boolean;
2340 -- Set True to indicate that at there is at least one entity on the
2341 -- homonym chain which, while not visible, is visible enough from the
2342 -- user point of view to warrant an error message of "not visible"
2343 -- rather than undefined.
2345 function From_Actual_Package
(E
: Entity_Id
) return Boolean;
2346 -- Returns true if the entity is declared in a package that is
2347 -- an actual for a formal package of the current instance. Such an
2348 -- entity requires special handling because it may be use-visible
2349 -- but hides directly visible entities defined outside the instance.
2351 function Known_But_Invisible
(E
: Entity_Id
) return Boolean;
2352 -- This function determines whether the entity E (which is not
2353 -- visible) can reasonably be considered to be known to the writer
2354 -- of the reference. This is a heuristic test, used only for the
2355 -- purposes of figuring out whether we prefer to complain that an
2356 -- entity is undefined or invisible (and identify the declaration
2357 -- of the invisible entity in the latter case). The point here is
2358 -- that we don't want to complain that something is invisible and
2359 -- then point to something entirely mysterious to the writer.
2361 procedure Nvis_Messages
;
2362 -- Called if there are no visible entries for N, but there is at least
2363 -- one non-directly visible, or hidden declaration. This procedure
2364 -- outputs an appropriate set of error messages.
2366 procedure Undefined
(Nvis
: Boolean);
2367 -- This function is called if the current node has no corresponding
2368 -- visible entity or entities. The value set in Msg indicates whether
2369 -- an error message was generated (multiple error messages for the
2370 -- same variable are generally suppressed, see body for details).
2371 -- Msg is True if an error message was generated, False if not. This
2372 -- value is used by the caller to determine whether or not to output
2373 -- additional messages where appropriate. The parameter is set False
2374 -- to get the message "X is undefined", and True to get the message
2375 -- "X is not visible".
2377 -------------------------
2378 -- From_Actual_Package --
2379 -------------------------
2381 function From_Actual_Package
(E
: Entity_Id
) return Boolean is
2382 Scop
: constant Entity_Id
:= Scope
(E
);
2386 if not In_Instance
then
2389 Inst
:= Current_Scope
;
2391 while Present
(Inst
)
2392 and then Ekind
(Inst
) /= E_Package
2393 and then not Is_Generic_Instance
(Inst
)
2395 Inst
:= Scope
(Inst
);
2402 Act
:= First_Entity
(Inst
);
2404 while Present
(Act
) loop
2405 if Ekind
(Act
) = E_Package
then
2407 -- Check for end of actuals list
2409 if Renamed_Object
(Act
) = Inst
then
2412 elsif Present
(Associated_Formal_Package
(Act
))
2413 and then Renamed_Object
(Act
) = Scop
2415 -- Entity comes from (instance of) formal package
2430 end From_Actual_Package
;
2432 -------------------------
2433 -- Known_But_Invisible --
2434 -------------------------
2436 function Known_But_Invisible
(E
: Entity_Id
) return Boolean is
2437 Fname
: File_Name_Type
;
2440 -- Entities in Standard are always considered to be known
2442 if Sloc
(E
) <= Standard_Location
then
2445 -- An entity that does not come from source is always considered
2446 -- to be unknown, since it is an artifact of code expansion.
2448 elsif not Comes_From_Source
(E
) then
2451 -- In gnat internal mode, we consider all entities known
2453 elsif GNAT_Mode
then
2457 -- Here we have an entity that is not from package Standard, and
2458 -- which comes from Source. See if it comes from an internal file.
2460 Fname
:= Unit_File_Name
(Get_Source_Unit
(E
));
2462 -- Case of from internal file
2464 if Is_Internal_File_Name
(Fname
) then
2466 -- Private part entities in internal files are never considered
2467 -- to be known to the writer of normal application code.
2469 if Is_Hidden
(E
) then
2473 -- Entities from System packages other than System and
2474 -- System.Storage_Elements are not considered to be known.
2475 -- System.Auxxxx files are also considered known to the user.
2477 -- Should refine this at some point to generally distinguish
2478 -- between known and unknown internal files ???
2480 Get_Name_String
(Fname
);
2485 Name_Buffer
(1 .. 2) /= "s-"
2487 Name_Buffer
(3 .. 8) = "stoele"
2489 Name_Buffer
(3 .. 5) = "aux";
2491 -- If not an internal file, then entity is definitely known,
2492 -- even if it is in a private part (the message generated will
2493 -- note that it is in a private part)
2498 end Known_But_Invisible
;
2504 procedure Nvis_Messages
is
2506 Hidden
: Boolean := False;
2509 Undefined
(Nvis
=> True);
2513 -- First loop does hidden declarations
2516 while Present
(Ent
) loop
2517 if Is_Potentially_Use_Visible
(Ent
) then
2520 Error_Msg_N
("multiple use clauses cause hiding!", N
);
2524 Error_Msg_Sloc
:= Sloc
(Ent
);
2525 Error_Msg_N
("hidden declaration#!", N
);
2528 Ent
:= Homonym
(Ent
);
2531 -- If we found hidden declarations, then that's enough, don't
2532 -- bother looking for non-visible declarations as well.
2538 -- Second loop does non-directly visible declarations
2541 while Present
(Ent
) loop
2542 if not Is_Potentially_Use_Visible
(Ent
) then
2544 -- Do not bother the user with unknown entities
2546 if not Known_But_Invisible
(Ent
) then
2550 Error_Msg_Sloc
:= Sloc
(Ent
);
2552 -- Output message noting that there is a non-visible
2553 -- declaration, distinguishing the private part case.
2555 if Is_Hidden
(Ent
) then
2556 Error_Msg_N
("non-visible (private) declaration#!", N
);
2558 Error_Msg_N
("non-visible declaration#!", N
);
2560 if Is_Compilation_Unit
(Ent
)
2562 Nkind
(Parent
(Parent
(N
))) = N_Use_Package_Clause
2565 ("\possibly missing with_clause for&", N
, Ent
);
2569 -- Set entity and its containing package as referenced. We
2570 -- can't be sure of this, but this seems a better choice
2571 -- to avoid unused entity messages.
2573 if Comes_From_Source
(Ent
) then
2574 Set_Referenced
(Ent
);
2575 Set_Referenced
(Cunit_Entity
(Get_Source_Unit
(Ent
)));
2580 Ent
:= Homonym
(Ent
);
2590 procedure Undefined
(Nvis
: Boolean) is
2591 Emsg
: Error_Msg_Id
;
2594 -- We should never find an undefined internal name. If we do, then
2595 -- see if we have previous errors. If so, ignore on the grounds that
2596 -- it is probably a cascaded message (e.g. a block label from a badly
2597 -- formed block). If no previous errors, then we have a real internal
2598 -- error of some kind so raise an exception.
2600 if Is_Internal_Name
(Chars
(N
)) then
2601 if Total_Errors_Detected
/= 0 then
2604 raise Program_Error
;
2608 -- A very specialized error check, if the undefined variable is
2609 -- a case tag, and the case type is an enumeration type, check
2610 -- for a possible misspelling, and if so, modify the identifier
2612 -- Named aggregate should also be handled similarly ???
2614 if Nkind
(N
) = N_Identifier
2615 and then Nkind
(Parent
(N
)) = N_Case_Statement_Alternative
2617 Get_Name_String
(Chars
(N
));
2620 Case_Str
: constant String := Name_Buffer
(1 .. Name_Len
);
2621 Case_Stm
: constant Node_Id
:= Parent
(Parent
(N
));
2622 Case_Typ
: constant Entity_Id
:= Etype
(Expression
(Case_Stm
));
2627 if Is_Enumeration_Type
(Case_Typ
)
2628 and then Case_Typ
/= Standard_Character
2629 and then Case_Typ
/= Standard_Wide_Character
2631 Lit
:= First_Literal
(Case_Typ
);
2632 Get_Name_String
(Chars
(Lit
));
2634 if Chars
(Lit
) /= Chars
(N
)
2635 and then Is_Bad_Spelling_Of
2636 (Case_Str
, Name_Buffer
(1 .. Name_Len
))
2638 Error_Msg_Node_2
:= Lit
;
2640 ("& is undefined, assume misspelling of &", N
);
2641 Rewrite
(N
, New_Occurrence_Of
(Lit
, Sloc
(N
)));
2645 Lit
:= Next_Literal
(Lit
);
2650 -- Normal processing
2652 Set_Entity
(N
, Any_Id
);
2653 Set_Etype
(N
, Any_Type
);
2655 -- We use the table Urefs to keep track of entities for which we
2656 -- have issued errors for undefined references. Multiple errors
2657 -- for a single name are normally suppressed, however we modify
2658 -- the error message to alert the programmer to this effect.
2660 for J
in Urefs
.First
.. Urefs
.Last
loop
2661 if Chars
(N
) = Chars
(Urefs
.Table
(J
).Node
) then
2662 if Urefs
.Table
(J
).Err
/= No_Error_Msg
2663 and then Sloc
(N
) /= Urefs
.Table
(J
).Loc
2665 Error_Msg_Node_1
:= Urefs
.Table
(J
).Node
;
2667 if Urefs
.Table
(J
).Nvis
then
2668 Change_Error_Text
(Urefs
.Table
(J
).Err
,
2669 "& is not visible (more references follow)");
2671 Change_Error_Text
(Urefs
.Table
(J
).Err
,
2672 "& is undefined (more references follow)");
2675 Urefs
.Table
(J
).Err
:= No_Error_Msg
;
2678 -- Although we will set Msg False, and thus suppress the
2679 -- message, we also set Error_Posted True, to avoid any
2680 -- cascaded messages resulting from the undefined reference.
2683 Set_Error_Posted
(N
, True);
2688 -- If entry not found, this is first undefined occurrence
2691 Error_Msg_N
("& is not visible!", N
);
2695 Error_Msg_N
("& is undefined!", N
);
2698 -- A very bizarre special check, if the undefined identifier
2699 -- is put or put_line, then add a special error message (since
2700 -- this is a very common error for beginners to make).
2702 if Chars
(N
) = Name_Put
or else Chars
(N
) = Name_Put_Line
then
2703 Error_Msg_N
("\possible missing with of 'Text_'I'O!", N
);
2706 -- Now check for possible misspellings
2708 Get_Name_String
(Chars
(N
));
2712 Ematch
: Entity_Id
:= Empty
;
2714 Last_Name_Id
: constant Name_Id
:=
2715 Name_Id
(Nat
(First_Name_Id
) +
2716 Name_Entries_Count
- 1);
2718 S
: constant String (1 .. Name_Len
) :=
2719 Name_Buffer
(1 .. Name_Len
);
2722 for N
in First_Name_Id
.. Last_Name_Id
loop
2723 E
:= Get_Name_Entity_Id
(N
);
2726 and then (Is_Immediately_Visible
(E
)
2728 Is_Potentially_Use_Visible
(E
))
2730 Get_Name_String
(N
);
2732 if Is_Bad_Spelling_Of
2733 (Name_Buffer
(1 .. Name_Len
), S
)
2741 if Present
(Ematch
) then
2742 Error_Msg_NE
("\possible misspelling of&", N
, Ematch
);
2747 -- Make entry in undefined references table unless the full
2748 -- errors switch is set, in which case by refraining from
2749 -- generating the table entry, we guarantee that we get an
2750 -- error message for every undefined reference.
2752 if not All_Errors_Mode
then
2753 Urefs
.Increment_Last
;
2754 Urefs
.Table
(Urefs
.Last
).Node
:= N
;
2755 Urefs
.Table
(Urefs
.Last
).Err
:= Emsg
;
2756 Urefs
.Table
(Urefs
.Last
).Nvis
:= Nvis
;
2757 Urefs
.Table
(Urefs
.Last
).Loc
:= Sloc
(N
);
2763 -- Start of processing for Find_Direct_Name
2766 -- If the entity pointer is already set, this is an internal node, or
2767 -- a node that is analyzed more than once, after a tree modification.
2768 -- In such a case there is no resolution to perform, just set the type.
2770 if Present
(Entity
(N
)) then
2771 if Is_Type
(Entity
(N
)) then
2772 Set_Etype
(N
, Entity
(N
));
2776 Entyp
: constant Entity_Id
:= Etype
(Entity
(N
));
2779 -- One special case here. If the Etype field is already set,
2780 -- and references the packed array type corresponding to the
2781 -- etype of the referenced entity, then leave it alone. This
2782 -- happens for trees generated from Exp_Pakd, where expressions
2783 -- can be deliberately "mis-typed" to the packed array type.
2785 if Is_Array_Type
(Entyp
)
2786 and then Is_Packed
(Entyp
)
2787 and then Present
(Etype
(N
))
2788 and then Etype
(N
) = Packed_Array_Type
(Entyp
)
2792 -- If not that special case, then just reset the Etype
2795 Set_Etype
(N
, Etype
(Entity
(N
)));
2803 -- Here if Entity pointer was not set, we need full visibility analysis
2804 -- First we generate debugging output if the debug E flag is set.
2806 if Debug_Flag_E
then
2807 Write_Str
("Looking for ");
2808 Write_Name
(Chars
(N
));
2812 Homonyms
:= Current_Entity
(N
);
2813 Nvis_Entity
:= False;
2816 while Present
(E
) loop
2818 -- If entity is immediately visible or potentially use
2819 -- visible, then process the entity and we are done.
2821 if Is_Immediately_Visible
(E
) then
2822 goto Immediately_Visible_Entity
;
2824 elsif Is_Potentially_Use_Visible
(E
) then
2825 goto Potentially_Use_Visible_Entity
;
2827 -- Note if a known but invisible entity encountered
2829 elsif Known_But_Invisible
(E
) then
2830 Nvis_Entity
:= True;
2833 -- Move to next entity in chain and continue search
2838 -- If no entries on homonym chain that were potentially visible,
2839 -- and no entities reasonably considered as non-visible, then
2840 -- we have a plain undefined reference, with no additional
2841 -- explanation required!
2843 if not Nvis_Entity
then
2844 Undefined
(Nvis
=> False);
2846 -- Otherwise there is at least one entry on the homonym chain that
2847 -- is reasonably considered as being known and non-visible.
2855 -- Processing for a potentially use visible entry found. We must search
2856 -- the rest of the homonym chain for two reasons. First, if there is a
2857 -- directly visible entry, then none of the potentially use-visible
2858 -- entities are directly visible (RM 8.4(10)). Second, we need to check
2859 -- for the case of multiple potentially use-visible entries hiding one
2860 -- another and as a result being non-directly visible (RM 8.4(11)).
2862 <<Potentially_Use_Visible_Entity
>> declare
2863 Only_One_Visible
: Boolean := True;
2864 All_Overloadable
: Boolean := Is_Overloadable
(E
);
2869 while Present
(E2
) loop
2870 if Is_Immediately_Visible
(E2
) then
2872 -- If the use-visible entity comes from the actual for a
2873 -- formal package, it hides a directly visible entity from
2874 -- outside the instance.
2876 if From_Actual_Package
(E
)
2877 and then Scope_Depth
(E2
) < Scope_Depth
(Inst
)
2882 goto Immediately_Visible_Entity
;
2885 elsif Is_Potentially_Use_Visible
(E2
) then
2886 Only_One_Visible
:= False;
2887 All_Overloadable
:= All_Overloadable
and Is_Overloadable
(E2
);
2893 -- On falling through this loop, we have checked that there are no
2894 -- immediately visible entities. Only_One_Visible is set if exactly
2895 -- one potentially use visible entity exists. All_Overloadable is
2896 -- set if all the potentially use visible entities are overloadable.
2897 -- The condition for legality is that either there is one potentially
2898 -- use visible entity, or if there is more than one, then all of them
2899 -- are overloadable.
2901 if Only_One_Visible
or All_Overloadable
then
2904 -- If there is more than one potentially use-visible entity and at
2905 -- least one of them non-overloadable, we have an error (RM 8.4(11).
2906 -- Note that E points to the first such entity on the homonym list.
2907 -- Special case: if one of the entities is declared in an actual
2908 -- package, it was visible in the generic, and takes precedence over
2909 -- other entities that are potentially use-visible. Same if it is
2910 -- declared in a local instantiation of the current instance.
2914 Inst
:= Current_Scope
;
2916 -- Find current instance.
2918 while Present
(Inst
)
2919 and then Inst
/= Standard_Standard
2921 if Is_Generic_Instance
(Inst
) then
2925 Inst
:= Scope
(Inst
);
2930 while Present
(E2
) loop
2931 if From_Actual_Package
(E2
)
2933 (Is_Generic_Instance
(Scope
(E2
))
2934 and then Scope_Depth
(Scope
(E2
)) > Scope_Depth
(Inst
))
2953 -- Come here with E set to the first immediately visible entity on
2954 -- the homonym chain. This is the one we want unless there is another
2955 -- immediately visible entity further on in the chain for a more
2956 -- inner scope (RM 8.3(8)).
2958 <<Immediately_Visible_Entity
>> declare
2963 -- Find scope level of initial entity. When compiling through
2964 -- Rtsfind, the previous context is not completely invisible, and
2965 -- an outer entity may appear on the chain, whose scope is below
2966 -- the entry for Standard that delimits the current scope stack.
2967 -- Indicate that the level for this spurious entry is outside of
2968 -- the current scope stack.
2970 Level
:= Scope_Stack
.Last
;
2972 Scop
:= Scope_Stack
.Table
(Level
).Entity
;
2973 exit when Scop
= Scope
(E
);
2975 exit when Scop
= Standard_Standard
;
2978 -- Now search remainder of homonym chain for more inner entry
2979 -- If the entity is Standard itself, it has no scope, and we
2980 -- compare it with the stack entry directly.
2983 while Present
(E2
) loop
2984 if Is_Immediately_Visible
(E2
) then
2985 for J
in Level
+ 1 .. Scope_Stack
.Last
loop
2986 if Scope_Stack
.Table
(J
).Entity
= Scope
(E2
)
2987 or else Scope_Stack
.Table
(J
).Entity
= E2
2999 -- At the end of that loop, E is the innermost immediately
3000 -- visible entity, so we are all set.
3003 -- Come here with entity found, and stored in E
3007 if Comes_From_Source
(N
)
3008 and then Is_Remote_Access_To_Subprogram_Type
(E
)
3009 and then Expander_Active
3012 New_Occurrence_Of
(Equivalent_Type
(E
), Sloc
(N
)));
3017 -- Why no Style_Check here???
3022 Set_Etype
(N
, Get_Full_View
(Etype
(E
)));
3025 if Debug_Flag_E
then
3026 Write_Str
(" found ");
3027 Write_Entity_Info
(E
, " ");
3030 -- If the Ekind of the entity is Void, it means that all homonyms
3031 -- are hidden from all visibility (RM 8.3(5,14-20)). However, this
3032 -- test is skipped if the current scope is a record and the name is
3033 -- a pragma argument expression (case of Atomic and Volatile pragmas
3034 -- and possibly other similar pragmas added later, which are allowed
3035 -- to reference components in the current record).
3037 if Ekind
(E
) = E_Void
3039 (not Is_Record_Type
(Current_Scope
)
3040 or else Nkind
(Parent
(N
)) /= N_Pragma_Argument_Association
)
3042 Premature_Usage
(N
);
3044 -- If the entity is overloadable, collect all interpretations
3045 -- of the name for subsequent overload resolution. We optimize
3046 -- a bit here to do this only if we have an overloadable entity
3047 -- that is not on its own on the homonym chain.
3049 elsif Is_Overloadable
(E
)
3050 and then (Present
(Homonym
(E
)) or else Current_Entity
(N
) /= E
)
3052 Collect_Interps
(N
);
3054 -- If no homonyms were visible, the entity is unambiguous.
3056 if not Is_Overloaded
(N
) then
3057 Generate_Reference
(E
, N
);
3060 -- Case of non-overloadable entity, set the entity providing that
3061 -- we do not have the case of a discriminant reference within a
3062 -- default expression. Such references are replaced with the
3063 -- corresponding discriminal, which is the formal corresponding to
3064 -- to the discriminant in the initialization procedure.
3067 -- Entity is unambiguous, indicate that it is referenced here
3068 -- One slightly odd case is that we do not want to set the
3069 -- Referenced flag if the entity is a label, and the identifier
3070 -- is the label in the source, since this is not a reference
3071 -- from the point of view of the user
3073 if Nkind
(Parent
(N
)) = N_Label
then
3075 R
: constant Boolean := Referenced
(E
);
3078 Generate_Reference
(E
, N
);
3079 Set_Referenced
(E
, R
);
3082 -- Normal case, not a label. Generate reference.
3085 Generate_Reference
(E
, N
);
3088 -- Set Entity, with style check if need be. If this is a
3089 -- discriminant reference, it must be replaced by the
3090 -- corresponding discriminal, that is to say the parameter
3091 -- of the initialization procedure that corresponds to the
3092 -- discriminant. If this replacement is being performed, there
3093 -- is no style check to perform.
3095 -- This replacement must not be done if we are currently
3096 -- processing a generic spec or body, because the discriminal
3097 -- has not been not generated in this case.
3099 if not In_Default_Expression
3100 or else Ekind
(E
) /= E_Discriminant
3101 or else Inside_A_Generic
3103 Set_Entity_With_Style_Check
(N
, E
);
3105 -- The replacement is not done either for a task discriminant that
3106 -- appears in a default expression of an entry parameter. See
3107 -- Expand_Discriminant in exp_ch2 for details on their handling.
3109 elsif Is_Concurrent_Type
(Scope
(E
)) then
3111 P
: Node_Id
:= Parent
(N
);
3115 and then Nkind
(P
) /= N_Parameter_Specification
3116 and then Nkind
(P
) /= N_Component_Declaration
3122 and then Nkind
(P
) = N_Parameter_Specification
3126 Set_Entity
(N
, Discriminal
(E
));
3130 -- Otherwise, this is a discriminant in a context in which
3131 -- it is a reference to the corresponding parameter of the
3132 -- init proc for the enclosing type.
3135 Set_Entity
(N
, Discriminal
(E
));
3139 end Find_Direct_Name
;
3141 ------------------------
3142 -- Find_Expanded_Name --
3143 ------------------------
3145 -- This routine searches the homonym chain of the entity until it finds
3146 -- an entity declared in the scope denoted by the prefix. If the entity
3147 -- is private, it may nevertheless be immediately visible, if we are in
3148 -- the scope of its declaration.
3150 procedure Find_Expanded_Name
(N
: Node_Id
) is
3151 Selector
: constant Node_Id
:= Selector_Name
(N
);
3152 Candidate
: Entity_Id
:= Empty
;
3158 P_Name
:= Entity
(Prefix
(N
));
3161 -- If the prefix is a renamed package, look for the entity
3162 -- in the original package.
3164 if Ekind
(P_Name
) = E_Package
3165 and then Present
(Renamed_Object
(P_Name
))
3167 P_Name
:= Renamed_Object
(P_Name
);
3169 -- Rewrite node with entity field pointing to renamed object
3171 Rewrite
(Prefix
(N
), New_Copy
(Prefix
(N
)));
3172 Set_Entity
(Prefix
(N
), P_Name
);
3174 -- If the prefix is an object of a concurrent type, look for
3175 -- the entity in the associated task or protected type.
3177 elsif Is_Concurrent_Type
(Etype
(P_Name
)) then
3178 P_Name
:= Etype
(P_Name
);
3181 Id
:= Current_Entity
(Selector
);
3183 while Present
(Id
) loop
3185 if Scope
(Id
) = P_Name
then
3188 if Is_Child_Unit
(Id
) then
3189 exit when Is_Visible_Child_Unit
(Id
)
3190 or else Is_Immediately_Visible
(Id
);
3193 exit when not Is_Hidden
(Id
)
3194 or else Is_Immediately_Visible
(Id
);
3202 and then (Ekind
(P_Name
) = E_Procedure
3204 Ekind
(P_Name
) = E_Function
)
3205 and then Is_Generic_Instance
(P_Name
)
3207 -- Expanded name denotes entity in (instance of) generic subprogram.
3208 -- The entity may be in the subprogram instance, or may denote one of
3209 -- the formals, which is declared in the enclosing wrapper package.
3211 P_Name
:= Scope
(P_Name
);
3212 Id
:= Current_Entity
(Selector
);
3214 while Present
(Id
) loop
3215 exit when Scope
(Id
) = P_Name
;
3220 if No
(Id
) or else Chars
(Id
) /= Chars
(Selector
) then
3222 Set_Etype
(N
, Any_Type
);
3224 -- If we are looking for an entity defined in System, try to
3225 -- find it in the child package that may have been provided as
3226 -- an extension to System. The Extend_System pragma will have
3227 -- supplied the name of the extension, which may have to be loaded.
3229 if Chars
(P_Name
) = Name_System
3230 and then Scope
(P_Name
) = Standard_Standard
3231 and then Present
(System_Extend_Unit
)
3232 and then Present_System_Aux
(N
)
3234 Set_Entity
(Prefix
(N
), System_Aux_Id
);
3235 Find_Expanded_Name
(N
);
3238 elsif Nkind
(Selector
) = N_Operator_Symbol
3239 and then Has_Implicit_Operator
(N
)
3241 -- There is an implicit instance of the predefined operator in
3242 -- the given scope. The operator entity is defined in Standard.
3243 -- Has_Implicit_Operator makes the node into an Expanded_Name.
3247 elsif Nkind
(Selector
) = N_Character_Literal
3248 and then Has_Implicit_Character_Literal
(N
)
3250 -- If there is no literal defined in the scope denoted by the
3251 -- prefix, the literal may belong to (a type derived from)
3252 -- Standard_Character, for which we have no explicit literals.
3257 -- If the prefix is a single concurrent object, use its
3258 -- name in the error message, rather than that of the
3261 if Is_Concurrent_Type
(P_Name
)
3262 and then Is_Internal_Name
(Chars
(P_Name
))
3264 Error_Msg_Node_2
:= Entity
(Prefix
(N
));
3266 Error_Msg_Node_2
:= P_Name
;
3269 if P_Name
= System_Aux_Id
then
3270 P_Name
:= Scope
(P_Name
);
3271 Set_Entity
(Prefix
(N
), P_Name
);
3274 if Present
(Candidate
) then
3276 if Is_Child_Unit
(Candidate
) then
3278 ("missing with_clause for child unit &", Selector
);
3280 Error_Msg_NE
("& is not a visible entity of&", N
, Selector
);
3284 -- Within the instantiation of a child unit, the prefix may
3285 -- denote the parent instance, but the selector has the
3286 -- name of the original child. Find whether we are within
3287 -- the corresponding instance, and get the proper entity, which
3288 -- can only be an enclosing scope.
3291 and then In_Open_Scopes
(P_Name
)
3292 and then Is_Generic_Instance
(P_Name
)
3295 S
: Entity_Id
:= Current_Scope
;
3299 for J
in reverse 0 .. Scope_Stack
.Last
loop
3300 S
:= Scope_Stack
.Table
(J
).Entity
;
3302 exit when S
= Standard_Standard
;
3304 if Ekind
(S
) = E_Function
3305 or else Ekind
(S
) = E_Package
3306 or else Ekind
(S
) = E_Procedure
3308 P
:= Generic_Parent
(Specification
3309 (Unit_Declaration_Node
(S
)));
3312 and then Chars
(Scope
(P
)) = Chars
(O_Name
)
3313 and then Chars
(P
) = Chars
(Selector
)
3324 if Chars
(P_Name
) = Name_Ada
3325 and then Scope
(P_Name
) = Standard_Standard
3327 Error_Msg_Node_2
:= Selector
;
3328 Error_Msg_NE
("missing with for `&.&`", N
, P_Name
);
3330 -- If this is a selection from a dummy package, then
3331 -- suppress the error message, of course the entity
3332 -- is missing if the package is missing!
3334 elsif Sloc
(Error_Msg_Node_2
) = No_Location
then
3337 -- Here we have the case of an undefined component
3341 Error_Msg_NE
("& not declared in&", N
, Selector
);
3343 -- Check for misspelling of some entity in prefix.
3345 Id
:= First_Entity
(P_Name
);
3346 Get_Name_String
(Chars
(Selector
));
3349 S
: constant String (1 .. Name_Len
) :=
3350 Name_Buffer
(1 .. Name_Len
);
3352 while Present
(Id
) loop
3353 Get_Name_String
(Chars
(Id
));
3354 if Is_Bad_Spelling_Of
3355 (Name_Buffer
(1 .. Name_Len
), S
)
3356 and then not Is_Internal_Name
(Chars
(Id
))
3359 ("possible misspelling of&", Selector
, Id
);
3367 -- Specialize the message if this may be an instantiation
3368 -- of a child unit that was not mentioned in the context.
3370 if Nkind
(Parent
(N
)) = N_Package_Instantiation
3371 and then Is_Generic_Instance
(Entity
(Prefix
(N
)))
3372 and then Is_Compilation_Unit
3373 (Generic_Parent
(Parent
(Entity
(Prefix
(N
)))))
3376 ("\possible missing with clause on child unit&",
3387 if Comes_From_Source
(N
)
3388 and then Is_Remote_Access_To_Subprogram_Type
(Id
)
3390 Id
:= Equivalent_Type
(Id
);
3391 Set_Chars
(Selector
, Chars
(Id
));
3394 -- Ada0Y (AI-50217): Check usage of entities in limited withed units
3396 if Ekind
(P_Name
) = E_Package
3397 and then From_With_Type
(P_Name
)
3399 if From_With_Type
(Id
)
3400 or else (Ekind
(Id
) = E_Package
and then From_With_Type
(Id
))
3405 ("limited withed package can only be used to access "
3406 & " incomplete types",
3411 if Is_Task_Type
(P_Name
)
3412 and then ((Ekind
(Id
) = E_Entry
3413 and then Nkind
(Parent
(N
)) /= N_Attribute_Reference
)
3415 (Ekind
(Id
) = E_Entry_Family
3417 Nkind
(Parent
(Parent
(N
))) /= N_Attribute_Reference
))
3419 -- It is an entry call after all, either to the current task
3420 -- (which will deadlock) or to an enclosing task.
3422 Analyze_Selected_Component
(N
);
3426 Change_Selected_Component_To_Expanded_Name
(N
);
3428 -- Do style check and generate reference, but skip both steps if this
3429 -- entity has homonyms, since we may not have the right homonym set
3430 -- yet. The proper homonym will be set during the resolve phase.
3432 if Has_Homonym
(Id
) then
3435 Set_Entity_With_Style_Check
(N
, Id
);
3436 Generate_Reference
(Id
, N
);
3439 if Is_Type
(Id
) then
3442 Set_Etype
(N
, Get_Full_View
(Etype
(Id
)));
3445 -- If the Ekind of the entity is Void, it means that all homonyms
3446 -- are hidden from all visibility (RM 8.3(5,14-20)).
3448 if Ekind
(Id
) = E_Void
then
3449 Premature_Usage
(N
);
3451 elsif Is_Overloadable
(Id
)
3452 and then Present
(Homonym
(Id
))
3455 H
: Entity_Id
:= Homonym
(Id
);
3458 while Present
(H
) loop
3459 if Scope
(H
) = Scope
(Id
) then
3460 Collect_Interps
(N
);
3467 -- If an extension of System is present, collect possible
3468 -- explicit overloadings declared in the extension.
3470 if Chars
(P_Name
) = Name_System
3471 and then Scope
(P_Name
) = Standard_Standard
3472 and then Present
(System_Extend_Unit
)
3473 and then Present_System_Aux
(N
)
3475 H
:= Current_Entity
(Id
);
3477 while Present
(H
) loop
3478 if Scope
(H
) = System_Aux_Id
then
3479 Add_One_Interp
(N
, H
, Etype
(H
));
3488 if Nkind
(Selector_Name
(N
)) = N_Operator_Symbol
3489 and then Scope
(Id
) /= Standard_Standard
3491 -- In addition to user-defined operators in the given scope,
3492 -- there may be an implicit instance of the predefined
3493 -- operator. The operator (defined in Standard) is found
3494 -- in Has_Implicit_Operator, and added to the interpretations.
3495 -- Procedure Add_One_Interp will determine which hides which.
3497 if Has_Implicit_Operator
(N
) then
3501 end Find_Expanded_Name
;
3503 -------------------------
3504 -- Find_Renamed_Entity --
3505 -------------------------
3507 function Find_Renamed_Entity
3511 Is_Actual
: Boolean := False) return Entity_Id
3514 I1
: Interp_Index
:= 0; -- Suppress junk warnings
3520 function Enclosing_Instance
return Entity_Id
;
3521 -- If the renaming determines the entity for the default of a formal
3522 -- subprogram nested within another instance, choose the innermost
3523 -- candidate. This is because if the formal has a box, and we are within
3524 -- an enclosing instance where some candidate interpretations are local
3525 -- to this enclosing instance, we know that the default was properly
3526 -- resolved when analyzing the generic, so we prefer the local
3527 -- candidates to those that are external. This is not always the case
3528 -- but is a reasonable heuristic on the use of nested generics.
3529 -- The proper solution requires a full renaming model.
3531 function Within
(Inner
, Outer
: Entity_Id
) return Boolean;
3532 -- Determine whether a candidate subprogram is defined within
3533 -- the enclosing instance. If yes, it has precedence over outer
3536 function Is_Visible_Operation
(Op
: Entity_Id
) return Boolean;
3537 -- If the renamed entity is an implicit operator, check whether it is
3538 -- visible because its operand type is properly visible. This
3539 -- check applies to explicit renamed entities that appear in the
3540 -- source in a renaming declaration or a formal subprogram instance,
3541 -- but not to default generic actuals with a name.
3543 ------------------------
3544 -- Enclosing_Instance --
3545 ------------------------
3547 function Enclosing_Instance
return Entity_Id
is
3551 if not Is_Generic_Instance
(Current_Scope
)
3552 and then not Is_Actual
3557 S
:= Scope
(Current_Scope
);
3559 while S
/= Standard_Standard
loop
3561 if Is_Generic_Instance
(S
) then
3569 end Enclosing_Instance
;
3571 --------------------------
3572 -- Is_Visible_Operation --
3573 --------------------------
3575 function Is_Visible_Operation
(Op
: Entity_Id
) return Boolean is
3581 if Ekind
(Op
) /= E_Operator
3582 or else Scope
(Op
) /= Standard_Standard
3583 or else (In_Instance
3586 or else Present
(Enclosing_Instance
)))
3591 -- For a fixed point type operator, check the resulting type,
3592 -- because it may be a mixed mode integer * fixed operation.
3594 if Present
(Next_Formal
(First_Formal
(New_S
)))
3595 and then Is_Fixed_Point_Type
(Etype
(New_S
))
3597 Typ
:= Etype
(New_S
);
3599 Typ
:= Etype
(First_Formal
(New_S
));
3602 Btyp
:= Base_Type
(Typ
);
3604 if Nkind
(Nam
) /= N_Expanded_Name
then
3605 return (In_Open_Scopes
(Scope
(Btyp
))
3606 or else Is_Potentially_Use_Visible
(Btyp
)
3607 or else In_Use
(Btyp
)
3608 or else In_Use
(Scope
(Btyp
)));
3611 Scop
:= Entity
(Prefix
(Nam
));
3613 if Ekind
(Scop
) = E_Package
3614 and then Present
(Renamed_Object
(Scop
))
3616 Scop
:= Renamed_Object
(Scop
);
3619 -- Operator is visible if prefix of expanded name denotes
3620 -- scope of type, or else type type is defined in System_Aux
3621 -- and the prefix denotes System.
3623 return Scope
(Btyp
) = Scop
3624 or else (Scope
(Btyp
) = System_Aux_Id
3625 and then Scope
(Scope
(Btyp
)) = Scop
);
3628 end Is_Visible_Operation
;
3634 function Within
(Inner
, Outer
: Entity_Id
) return Boolean is
3635 Sc
: Entity_Id
:= Scope
(Inner
);
3638 while Sc
/= Standard_Standard
loop
3650 function Report_Overload
return Entity_Id
;
3651 -- List possible interpretations, and specialize message in the
3652 -- case of a generic actual.
3654 function Report_Overload
return Entity_Id
is
3658 ("ambiguous actual subprogram&, " &
3659 "possible interpretations: ", N
, Nam
);
3662 ("ambiguous subprogram, " &
3663 "possible interpretations: ", N
);
3666 List_Interps
(Nam
, N
);
3668 end Report_Overload
;
3670 -- Start of processing for Find_Renamed_Entry
3674 Candidate_Renaming
:= Empty
;
3676 if not Is_Overloaded
(Nam
) then
3677 if Entity_Matches_Spec
(Entity
(Nam
), New_S
)
3678 and then Is_Visible_Operation
(Entity
(Nam
))
3680 Old_S
:= Entity
(Nam
);
3683 Present
(First_Formal
(Entity
(Nam
)))
3684 and then Present
(First_Formal
(New_S
))
3685 and then (Base_Type
(Etype
(First_Formal
(Entity
(Nam
))))
3686 = Base_Type
(Etype
(First_Formal
(New_S
))))
3688 Candidate_Renaming
:= Entity
(Nam
);
3692 Get_First_Interp
(Nam
, Ind
, It
);
3694 while Present
(It
.Nam
) loop
3696 if Entity_Matches_Spec
(It
.Nam
, New_S
)
3697 and then Is_Visible_Operation
(It
.Nam
)
3699 if Old_S
/= Any_Id
then
3701 -- Note: The call to Disambiguate only happens if a
3702 -- previous interpretation was found, in which case I1
3703 -- has received a value.
3705 It1
:= Disambiguate
(Nam
, I1
, Ind
, Etype
(Old_S
));
3707 if It1
= No_Interp
then
3709 Inst
:= Enclosing_Instance
;
3711 if Present
(Inst
) then
3713 if Within
(It
.Nam
, Inst
) then
3716 elsif Within
(Old_S
, Inst
) then
3720 return Report_Overload
;
3724 return Report_Overload
;
3738 Present
(First_Formal
(It
.Nam
))
3739 and then Present
(First_Formal
(New_S
))
3740 and then (Base_Type
(Etype
(First_Formal
(It
.Nam
)))
3741 = Base_Type
(Etype
(First_Formal
(New_S
))))
3743 Candidate_Renaming
:= It
.Nam
;
3746 Get_Next_Interp
(Ind
, It
);
3749 Set_Entity
(Nam
, Old_S
);
3750 Set_Is_Overloaded
(Nam
, False);
3754 end Find_Renamed_Entity
;
3756 -----------------------------
3757 -- Find_Selected_Component --
3758 -----------------------------
3760 procedure Find_Selected_Component
(N
: Node_Id
) is
3761 P
: constant Node_Id
:= Prefix
(N
);
3764 -- Entity denoted by prefix
3774 if Nkind
(P
) = N_Error
then
3777 -- If the selector already has an entity, the node has been
3778 -- constructed in the course of expansion, and is known to be
3779 -- valid. Do not verify that it is defined for the type (it may
3780 -- be a private component used in the expansion of record equality).
3782 elsif Present
(Entity
(Selector_Name
(N
))) then
3785 or else Etype
(N
) = Any_Type
3788 Sel_Name
: constant Node_Id
:= Selector_Name
(N
);
3789 Selector
: constant Entity_Id
:= Entity
(Sel_Name
);
3793 Set_Etype
(Sel_Name
, Etype
(Selector
));
3795 if not Is_Entity_Name
(P
) then
3799 -- Build an actual subtype except for the first parameter
3800 -- of an init proc, where this actual subtype is by
3801 -- definition incorrect, since the object is uninitialized
3802 -- (and does not even have defined discriminants etc.)
3804 if Is_Entity_Name
(P
)
3805 and then Ekind
(Entity
(P
)) = E_Function
3807 Nam
:= New_Copy
(P
);
3809 if Is_Overloaded
(P
) then
3810 Save_Interps
(P
, Nam
);
3814 Make_Function_Call
(Sloc
(P
), Name
=> Nam
));
3816 Analyze_Selected_Component
(N
);
3819 elsif Ekind
(Selector
) = E_Component
3820 and then (not Is_Entity_Name
(P
)
3821 or else Chars
(Entity
(P
)) /= Name_uInit
)
3824 Build_Actual_Subtype_Of_Component
(
3825 Etype
(Selector
), N
);
3830 if No
(C_Etype
) then
3831 C_Etype
:= Etype
(Selector
);
3833 Insert_Action
(N
, C_Etype
);
3834 C_Etype
:= Defining_Identifier
(C_Etype
);
3837 Set_Etype
(N
, C_Etype
);
3840 -- If this is the name of an entry or protected operation, and
3841 -- the prefix is an access type, insert an explicit dereference,
3842 -- so that entry calls are treated uniformly.
3844 if Is_Access_Type
(Etype
(P
))
3845 and then Is_Concurrent_Type
(Designated_Type
(Etype
(P
)))
3848 New_P
: constant Node_Id
:=
3849 Make_Explicit_Dereference
(Sloc
(P
),
3850 Prefix
=> Relocate_Node
(P
));
3853 Set_Etype
(P
, Designated_Type
(Etype
(Prefix
(P
))));
3857 -- If the selected component appears within a default expression
3858 -- and it has an actual subtype, the pre-analysis has not yet
3859 -- completed its analysis, because Insert_Actions is disabled in
3860 -- that context. Within the init proc of the enclosing type we
3861 -- must complete this analysis, if an actual subtype was created.
3863 elsif Inside_Init_Proc
then
3865 Typ
: constant Entity_Id
:= Etype
(N
);
3866 Decl
: constant Node_Id
:= Declaration_Node
(Typ
);
3869 if Nkind
(Decl
) = N_Subtype_Declaration
3870 and then not Analyzed
(Decl
)
3871 and then Is_List_Member
(Decl
)
3872 and then No
(Parent
(Decl
))
3875 Insert_Action
(N
, Decl
);
3882 elsif Is_Entity_Name
(P
) then
3883 P_Name
:= Entity
(P
);
3885 -- The prefix may denote an enclosing type which is the completion
3886 -- of an incomplete type declaration.
3888 if Is_Type
(P_Name
) then
3889 Set_Entity
(P
, Get_Full_View
(P_Name
));
3890 Set_Etype
(P
, Entity
(P
));
3891 P_Name
:= Entity
(P
);
3894 P_Type
:= Base_Type
(Etype
(P
));
3896 if Debug_Flag_E
then
3897 Write_Str
("Found prefix type to be ");
3898 Write_Entity_Info
(P_Type
, " "); Write_Eol
;
3901 -- First check for components of a record object (not the
3902 -- result of a call, which is handled below).
3904 if Is_Appropriate_For_Record
(P_Type
)
3905 and then not Is_Overloadable
(P_Name
)
3906 and then not Is_Type
(P_Name
)
3908 -- Selected component of record. Type checking will validate
3909 -- name of selector.
3911 Analyze_Selected_Component
(N
);
3913 elsif Is_Appropriate_For_Entry_Prefix
(P_Type
)
3914 and then not In_Open_Scopes
(P_Name
)
3915 and then (not Is_Concurrent_Type
(Etype
(P_Name
))
3916 or else not In_Open_Scopes
(Etype
(P_Name
)))
3918 -- Call to protected operation or entry. Type checking is
3919 -- needed on the prefix.
3921 Analyze_Selected_Component
(N
);
3923 elsif (In_Open_Scopes
(P_Name
)
3924 and then Ekind
(P_Name
) /= E_Void
3925 and then not Is_Overloadable
(P_Name
))
3926 or else (Is_Concurrent_Type
(Etype
(P_Name
))
3927 and then In_Open_Scopes
(Etype
(P_Name
)))
3929 -- Prefix denotes an enclosing loop, block, or task, i.e. an
3930 -- enclosing construct that is not a subprogram or accept.
3932 Find_Expanded_Name
(N
);
3934 elsif Ekind
(P_Name
) = E_Package
then
3935 Find_Expanded_Name
(N
);
3937 elsif Is_Overloadable
(P_Name
) then
3939 -- The subprogram may be a renaming (of an enclosing scope) as
3940 -- in the case of the name of the generic within an instantiation.
3942 if (Ekind
(P_Name
) = E_Procedure
3943 or else Ekind
(P_Name
) = E_Function
)
3944 and then Present
(Alias
(P_Name
))
3945 and then Is_Generic_Instance
(Alias
(P_Name
))
3947 P_Name
:= Alias
(P_Name
);
3950 if Is_Overloaded
(P
) then
3952 -- The prefix must resolve to a unique enclosing construct.
3955 Found
: Boolean := False;
3960 Get_First_Interp
(P
, Ind
, It
);
3962 while Present
(It
.Nam
) loop
3964 if In_Open_Scopes
(It
.Nam
) then
3967 "prefix must be unique enclosing scope", N
);
3968 Set_Entity
(N
, Any_Id
);
3969 Set_Etype
(N
, Any_Type
);
3978 Get_Next_Interp
(Ind
, It
);
3983 if In_Open_Scopes
(P_Name
) then
3984 Set_Entity
(P
, P_Name
);
3985 Set_Is_Overloaded
(P
, False);
3986 Find_Expanded_Name
(N
);
3989 -- If no interpretation as an expanded name is possible, it
3990 -- must be a selected component of a record returned by a
3991 -- function call. Reformat prefix as a function call, the
3992 -- rest is done by type resolution. If the prefix is a
3993 -- procedure or entry, as is P.X; this is an error.
3995 if Ekind
(P_Name
) /= E_Function
3996 and then (not Is_Overloaded
(P
)
3998 Nkind
(Parent
(N
)) = N_Procedure_Call_Statement
)
4001 -- Prefix may mention a package that is hidden by a local
4002 -- declaration: let the user know. Scan the full homonym
4003 -- chain, the candidate package may be anywhere on it.
4005 if Present
(Homonym
(Current_Entity
(P_Name
))) then
4007 P_Name
:= Current_Entity
(P_Name
);
4009 while Present
(P_Name
) loop
4010 exit when Ekind
(P_Name
) = E_Package
;
4011 P_Name
:= Homonym
(P_Name
);
4014 if Present
(P_Name
) then
4015 Error_Msg_Sloc
:= Sloc
(Entity
(Prefix
(N
)));
4018 ("package& is hidden by declaration#",
4021 Set_Entity
(Prefix
(N
), P_Name
);
4022 Find_Expanded_Name
(N
);
4025 P_Name
:= Entity
(Prefix
(N
));
4030 ("invalid prefix in selected component&", N
, P_Name
);
4031 Change_Selected_Component_To_Expanded_Name
(N
);
4032 Set_Entity
(N
, Any_Id
);
4033 Set_Etype
(N
, Any_Type
);
4036 Nam
:= New_Copy
(P
);
4037 Save_Interps
(P
, Nam
);
4039 Make_Function_Call
(Sloc
(P
), Name
=> Nam
));
4041 Analyze_Selected_Component
(N
);
4045 -- Remaining cases generate various error messages
4048 -- Format node as expanded name, to avoid cascaded errors
4050 Change_Selected_Component_To_Expanded_Name
(N
);
4051 Set_Entity
(N
, Any_Id
);
4052 Set_Etype
(N
, Any_Type
);
4054 -- Issue error message, but avoid this if error issued already.
4055 -- Use identifier of prefix if one is available.
4057 if P_Name
= Any_Id
then
4060 elsif Ekind
(P_Name
) = E_Void
then
4061 Premature_Usage
(P
);
4063 elsif Nkind
(P
) /= N_Attribute_Reference
then
4065 "invalid prefix in selected component&", P
);
4067 if Is_Access_Type
(P_Type
)
4068 and then Ekind
(Designated_Type
(P_Type
)) = E_Incomplete_Type
4071 ("\dereference must not be of an incomplete type " &
4072 "('R'M 3.10.1)", P
);
4077 "invalid prefix in selected component", P
);
4082 -- If prefix is not the name of an entity, it must be an expression,
4083 -- whose type is appropriate for a record. This is determined by
4086 Analyze_Selected_Component
(N
);
4088 end Find_Selected_Component
;
4094 procedure Find_Type
(N
: Node_Id
) is
4104 elsif Nkind
(N
) = N_Attribute_Reference
then
4106 -- Class attribute. This is only valid in Ada 95 mode, but we don't
4107 -- do a check, since the tagged type referenced could only exist if
4108 -- we were in 95 mode when it was declared (or, if we were in Ada
4109 -- 83 mode, then an error message would already have been issued).
4111 if Attribute_Name
(N
) = Name_Class
then
4112 Check_Restriction
(No_Dispatch
, N
);
4113 Find_Type
(Prefix
(N
));
4115 -- Propagate error from bad prefix
4117 if Etype
(Prefix
(N
)) = Any_Type
then
4118 Set_Entity
(N
, Any_Type
);
4119 Set_Etype
(N
, Any_Type
);
4123 T
:= Base_Type
(Entity
(Prefix
(N
)));
4125 -- Case of non-tagged type
4127 if not Is_Tagged_Type
(T
) then
4128 if Ekind
(T
) = E_Incomplete_Type
then
4130 -- It is legal to denote the class type of an incomplete
4131 -- type. The full type will have to be tagged, of course.
4133 Set_Is_Tagged_Type
(T
);
4134 Make_Class_Wide_Type
(T
);
4135 Set_Entity
(N
, Class_Wide_Type
(T
));
4136 Set_Etype
(N
, Class_Wide_Type
(T
));
4138 elsif Ekind
(T
) = E_Private_Type
4139 and then not Is_Generic_Type
(T
)
4140 and then In_Private_Part
(Scope
(T
))
4142 -- The Class attribute can be applied to an untagged
4143 -- private type fulfilled by a tagged type prior to
4144 -- the full type declaration (but only within the
4145 -- parent package's private part). Create the class-wide
4146 -- type now and check that the full type is tagged
4147 -- later during its analysis. Note that we do not
4148 -- mark the private type as tagged, unlike the case
4149 -- of incomplete types, because the type must still
4150 -- appear untagged to outside units.
4152 if not Present
(Class_Wide_Type
(T
)) then
4153 Make_Class_Wide_Type
(T
);
4156 Set_Entity
(N
, Class_Wide_Type
(T
));
4157 Set_Etype
(N
, Class_Wide_Type
(T
));
4160 -- Should we introduce a type Any_Tagged and use
4161 -- Wrong_Type here, it would be a bit more consistent???
4164 ("tagged type required, found}",
4165 Prefix
(N
), First_Subtype
(T
));
4166 Set_Entity
(N
, Any_Type
);
4170 -- Case of tagged type
4173 C
:= Class_Wide_Type
(Entity
(Prefix
(N
)));
4174 Set_Entity_With_Style_Check
(N
, C
);
4175 Generate_Reference
(C
, N
);
4179 -- Base attribute, allowed in Ada 95 mode only
4181 elsif Attribute_Name
(N
) = Name_Base
then
4182 if Ada_83
and then Comes_From_Source
(N
) then
4184 ("(Ada 83) Base attribute not allowed in subtype mark", N
);
4187 Find_Type
(Prefix
(N
));
4188 Typ
:= Entity
(Prefix
(N
));
4191 and then not Is_Scalar_Type
(Typ
)
4192 and then not Is_Generic_Type
(Typ
)
4195 ("prefix of Base attribute must be scalar type", Typ
);
4197 elsif Sloc
(Typ
) = Standard_Location
4198 and then Base_Type
(Typ
) = Typ
4199 and then Warn_On_Redundant_Constructs
4202 ("?redudant attribute, & is its own base type", N
, Typ
);
4205 T
:= Base_Type
(Typ
);
4207 -- Rewrite attribute reference with type itself (see similar
4208 -- processing in Analyze_Attribute, case Base). Preserve
4209 -- prefix if present, for other legality checks.
4211 if Nkind
(Prefix
(N
)) = N_Expanded_Name
then
4213 Make_Expanded_Name
(Sloc
(N
),
4214 Chars
=> Chars
(Entity
(N
)),
4215 Prefix
=> New_Copy
(Prefix
(Prefix
(N
))),
4217 New_Reference_To
(Entity
(N
), Sloc
(N
))));
4221 New_Reference_To
(Entity
(N
), Sloc
(N
)));
4228 -- All other attributes are invalid in a subtype mark
4231 Error_Msg_N
("invalid attribute in subtype mark", N
);
4237 if Is_Entity_Name
(N
) then
4238 T_Name
:= Entity
(N
);
4240 Error_Msg_N
("subtype mark required in this context", N
);
4241 Set_Etype
(N
, Any_Type
);
4245 if T_Name
= Any_Id
or else Etype
(N
) = Any_Type
then
4247 -- Undefined id. Make it into a valid type
4249 Set_Entity
(N
, Any_Type
);
4251 elsif not Is_Type
(T_Name
)
4252 and then T_Name
/= Standard_Void_Type
4254 Error_Msg_Sloc
:= Sloc
(T_Name
);
4255 Error_Msg_N
("subtype mark required in this context", N
);
4256 Error_Msg_NE
("\found & declared#", N
, T_Name
);
4257 Set_Entity
(N
, Any_Type
);
4260 T_Name
:= Get_Full_View
(T_Name
);
4262 if In_Open_Scopes
(T_Name
) then
4263 if Ekind
(Base_Type
(T_Name
)) = E_Task_Type
then
4264 Error_Msg_N
("task type cannot be used as type mark " &
4265 "within its own body", N
);
4267 Error_Msg_N
("type declaration cannot refer to itself", N
);
4270 Set_Etype
(N
, Any_Type
);
4271 Set_Entity
(N
, Any_Type
);
4272 Set_Error_Posted
(T_Name
);
4276 Set_Entity
(N
, T_Name
);
4277 Set_Etype
(N
, T_Name
);
4281 if Present
(Etype
(N
)) and then Comes_From_Source
(N
) then
4282 if Is_Fixed_Point_Type
(Etype
(N
)) then
4283 Check_Restriction
(No_Fixed_Point
, N
);
4284 elsif Is_Floating_Point_Type
(Etype
(N
)) then
4285 Check_Restriction
(No_Floating_Point
, N
);
4294 function Get_Full_View
(T_Name
: Entity_Id
) return Entity_Id
is
4296 if Ekind
(T_Name
) = E_Incomplete_Type
4297 and then Present
(Full_View
(T_Name
))
4299 return Full_View
(T_Name
);
4301 elsif Is_Class_Wide_Type
(T_Name
)
4302 and then Ekind
(Root_Type
(T_Name
)) = E_Incomplete_Type
4303 and then Present
(Full_View
(Root_Type
(T_Name
)))
4305 return Class_Wide_Type
(Full_View
(Root_Type
(T_Name
)));
4312 ------------------------------------
4313 -- Has_Implicit_Character_Literal --
4314 ------------------------------------
4316 function Has_Implicit_Character_Literal
(N
: Node_Id
) return Boolean is
4318 Found
: Boolean := False;
4319 P
: constant Entity_Id
:= Entity
(Prefix
(N
));
4320 Priv_Id
: Entity_Id
:= Empty
;
4323 if Ekind
(P
) = E_Package
4324 and then not In_Open_Scopes
(P
)
4326 Priv_Id
:= First_Private_Entity
(P
);
4329 if P
= Standard_Standard
then
4330 Change_Selected_Component_To_Expanded_Name
(N
);
4331 Rewrite
(N
, Selector_Name
(N
));
4333 Set_Etype
(Original_Node
(N
), Standard_Character
);
4337 Id
:= First_Entity
(P
);
4340 and then Id
/= Priv_Id
4342 if Is_Character_Type
(Id
)
4343 and then (Root_Type
(Id
) = Standard_Character
4344 or else Root_Type
(Id
) = Standard_Wide_Character
)
4345 and then Id
= Base_Type
(Id
)
4347 -- We replace the node with the literal itself, resolve as a
4348 -- character, and set the type correctly.
4351 Change_Selected_Component_To_Expanded_Name
(N
);
4352 Rewrite
(N
, Selector_Name
(N
));
4355 Set_Etype
(Original_Node
(N
), Id
);
4359 -- More than one type derived from Character in given scope.
4360 -- Collect all possible interpretations.
4362 Add_One_Interp
(N
, Id
, Id
);
4370 end Has_Implicit_Character_Literal
;
4372 ---------------------------
4373 -- Has_Implicit_Operator --
4374 ---------------------------
4376 function Has_Implicit_Operator
(N
: Node_Id
) return Boolean is
4377 Op_Id
: constant Name_Id
:= Chars
(Selector_Name
(N
));
4378 P
: constant Entity_Id
:= Entity
(Prefix
(N
));
4380 Priv_Id
: Entity_Id
:= Empty
;
4382 procedure Add_Implicit_Operator
4384 Op_Type
: Entity_Id
:= Empty
);
4385 -- Add implicit interpretation to node N, using the type for which
4386 -- a predefined operator exists. If the operator yields a boolean
4387 -- type, the Operand_Type is implicitly referenced by the operator,
4388 -- and a reference to it must be generated.
4390 ---------------------------
4391 -- Add_Implicit_Operator --
4392 ---------------------------
4394 procedure Add_Implicit_Operator
4396 Op_Type
: Entity_Id
:= Empty
)
4398 Predef_Op
: Entity_Id
;
4401 Predef_Op
:= Current_Entity
(Selector_Name
(N
));
4403 while Present
(Predef_Op
)
4404 and then Scope
(Predef_Op
) /= Standard_Standard
4406 Predef_Op
:= Homonym
(Predef_Op
);
4409 if Nkind
(N
) = N_Selected_Component
then
4410 Change_Selected_Component_To_Expanded_Name
(N
);
4413 Add_One_Interp
(N
, Predef_Op
, T
);
4415 -- For operators with unary and binary interpretations, add both
4417 if Present
(Homonym
(Predef_Op
)) then
4418 Add_One_Interp
(N
, Homonym
(Predef_Op
), T
);
4421 -- The node is a reference to a predefined operator, and
4422 -- an implicit reference to the type of its operands.
4424 if Present
(Op_Type
) then
4425 Generate_Operator_Reference
(N
, Op_Type
);
4427 Generate_Operator_Reference
(N
, T
);
4429 end Add_Implicit_Operator
;
4431 -- Start of processing for Has_Implicit_Operator
4435 if Ekind
(P
) = E_Package
4436 and then not In_Open_Scopes
(P
)
4438 Priv_Id
:= First_Private_Entity
(P
);
4441 Id
:= First_Entity
(P
);
4445 -- Boolean operators: an implicit declaration exists if the scope
4446 -- contains a declaration for a derived Boolean type, or for an
4447 -- array of Boolean type.
4449 when Name_Op_And | Name_Op_Not | Name_Op_Or | Name_Op_Xor
=>
4451 while Id
/= Priv_Id
loop
4453 if Valid_Boolean_Arg
(Id
)
4454 and then Id
= Base_Type
(Id
)
4456 Add_Implicit_Operator
(Id
);
4463 -- Equality: look for any non-limited type. Result is Boolean.
4465 when Name_Op_Eq | Name_Op_Ne
=>
4467 while Id
/= Priv_Id
loop
4470 and then not Is_Limited_Type
(Id
)
4471 and then Id
= Base_Type
(Id
)
4473 Add_Implicit_Operator
(Standard_Boolean
, Id
);
4480 -- Comparison operators: scalar type, or array of scalar.
4482 when Name_Op_Lt | Name_Op_Le | Name_Op_Gt | Name_Op_Ge
=>
4484 while Id
/= Priv_Id
loop
4485 if (Is_Scalar_Type
(Id
)
4486 or else (Is_Array_Type
(Id
)
4487 and then Is_Scalar_Type
(Component_Type
(Id
))))
4488 and then Id
= Base_Type
(Id
)
4490 Add_Implicit_Operator
(Standard_Boolean
, Id
);
4497 -- Arithmetic operators: any numeric type
4508 while Id
/= Priv_Id
loop
4509 if Is_Numeric_Type
(Id
)
4510 and then Id
= Base_Type
(Id
)
4512 Add_Implicit_Operator
(Id
);
4519 -- Concatenation: any one-dimensional array type
4521 when Name_Op_Concat
=>
4523 while Id
/= Priv_Id
loop
4524 if Is_Array_Type
(Id
) and then Number_Dimensions
(Id
) = 1
4525 and then Id
= Base_Type
(Id
)
4527 Add_Implicit_Operator
(Id
);
4534 -- What is the others condition here? Should we be using a
4535 -- subtype of Name_Id that would restrict to operators ???
4537 when others => null;
4541 -- If we fall through, then we do not have an implicit operator
4545 end Has_Implicit_Operator
;
4547 --------------------
4548 -- In_Open_Scopes --
4549 --------------------
4551 function In_Open_Scopes
(S
: Entity_Id
) return Boolean is
4553 -- Since there are several scope stacks maintained by Scope_Stack each
4554 -- delineated by Standard (see comments by definition of Scope_Stack)
4555 -- it is necessary to end the search when Standard is reached.
4557 for J
in reverse 0 .. Scope_Stack
.Last
loop
4558 if Scope_Stack
.Table
(J
).Entity
= S
then
4562 -- We need Is_Active_Stack_Base to tell us when to stop rather
4563 -- than checking for Standard_Standard because there are cases
4564 -- where Standard_Standard appears in the middle of the active
4565 -- set of scopes. This affects the declaration and overriding
4566 -- of private inherited operations in instantiations of generic
4569 exit when Scope_Stack
.Table
(J
).Is_Active_Stack_Base
;
4575 -----------------------------
4576 -- Inherit_Renamed_Profile --
4577 -----------------------------
4579 procedure Inherit_Renamed_Profile
(New_S
: Entity_Id
; Old_S
: Entity_Id
) is
4586 if Ekind
(Old_S
) = E_Operator
then
4588 New_F
:= First_Formal
(New_S
);
4590 while Present
(New_F
) loop
4591 Set_Etype
(New_F
, Base_Type
(Etype
(New_F
)));
4592 Next_Formal
(New_F
);
4595 Set_Etype
(New_S
, Base_Type
(Etype
(New_S
)));
4598 New_F
:= First_Formal
(New_S
);
4599 Old_F
:= First_Formal
(Old_S
);
4601 while Present
(New_F
) loop
4602 New_T
:= Etype
(New_F
);
4603 Old_T
:= Etype
(Old_F
);
4605 -- If the new type is a renaming of the old one, as is the
4606 -- case for actuals in instances, retain its name, to simplify
4607 -- later disambiguation.
4609 if Nkind
(Parent
(New_T
)) = N_Subtype_Declaration
4610 and then Is_Entity_Name
(Subtype_Indication
(Parent
(New_T
)))
4611 and then Entity
(Subtype_Indication
(Parent
(New_T
))) = Old_T
4615 Set_Etype
(New_F
, Old_T
);
4618 Next_Formal
(New_F
);
4619 Next_Formal
(Old_F
);
4622 if Ekind
(Old_S
) = E_Function
4623 or else Ekind
(Old_S
) = E_Enumeration_Literal
4625 Set_Etype
(New_S
, Etype
(Old_S
));
4628 end Inherit_Renamed_Profile
;
4634 procedure Initialize
is
4639 -------------------------
4640 -- Install_Use_Clauses --
4641 -------------------------
4643 procedure Install_Use_Clauses
(Clause
: Node_Id
) is
4644 U
: Node_Id
:= Clause
;
4649 while Present
(U
) loop
4651 -- Case of USE package
4653 if Nkind
(U
) = N_Use_Package_Clause
then
4654 P
:= First
(Names
(U
));
4656 while Present
(P
) loop
4659 if Ekind
(Id
) = E_Package
then
4662 Set_Redundant_Use
(P
, True);
4664 elsif Present
(Renamed_Object
(Id
))
4665 and then In_Use
(Renamed_Object
(Id
))
4667 Set_Redundant_Use
(P
, True);
4670 Use_One_Package
(Id
, U
);
4680 P
:= First
(Subtype_Marks
(U
));
4682 while Present
(P
) loop
4683 if not Is_Entity_Name
(P
)
4684 or else No
(Entity
(P
))
4688 elsif Entity
(P
) /= Any_Type
then
4696 Next_Use_Clause
(U
);
4698 end Install_Use_Clauses
;
4700 -------------------------------------
4701 -- Is_Appropriate_For_Entry_Prefix --
4702 -------------------------------------
4704 function Is_Appropriate_For_Entry_Prefix
(T
: Entity_Id
) return Boolean is
4705 P_Type
: Entity_Id
:= T
;
4708 if Is_Access_Type
(P_Type
) then
4709 P_Type
:= Designated_Type
(P_Type
);
4712 return Is_Task_Type
(P_Type
) or else Is_Protected_Type
(P_Type
);
4713 end Is_Appropriate_For_Entry_Prefix
;
4715 -------------------------------
4716 -- Is_Appropriate_For_Record --
4717 -------------------------------
4719 function Is_Appropriate_For_Record
4723 function Has_Components
(T1
: Entity_Id
) return Boolean;
4724 -- Determine if given type has components (i.e. is either a record
4725 -- type or a type that has discriminants).
4727 function Has_Components
(T1
: Entity_Id
) return Boolean is
4729 return Is_Record_Type
(T1
)
4730 or else (Is_Private_Type
(T1
) and then Has_Discriminants
(T1
))
4731 or else (Is_Task_Type
(T1
) and then Has_Discriminants
(T1
));
4734 -- Start of processing for Is_Appropriate_For_Record
4739 and then (Has_Components
(T
)
4740 or else (Is_Access_Type
(T
)
4742 Has_Components
(Designated_Type
(T
))));
4743 end Is_Appropriate_For_Record
;
4749 procedure New_Scope
(S
: Entity_Id
) is
4753 if Ekind
(S
) = E_Void
then
4756 -- Set scope depth if not a non-concurrent type, and we have not
4757 -- yet set the scope depth. This means that we have the first
4758 -- occurrence of the scope, and this is where the depth is set.
4760 elsif (not Is_Type
(S
) or else Is_Concurrent_Type
(S
))
4761 and then not Scope_Depth_Set
(S
)
4763 if S
= Standard_Standard
then
4764 Set_Scope_Depth_Value
(S
, Uint_0
);
4766 elsif Is_Child_Unit
(S
) then
4767 Set_Scope_Depth_Value
(S
, Uint_1
);
4769 elsif not Is_Record_Type
(Current_Scope
) then
4770 if Ekind
(S
) = E_Loop
then
4771 Set_Scope_Depth_Value
(S
, Scope_Depth
(Current_Scope
));
4773 Set_Scope_Depth_Value
(S
, Scope_Depth
(Current_Scope
) + 1);
4778 Scope_Stack
.Increment_Last
;
4781 SST
: Scope_Stack_Entry
renames Scope_Stack
.Table
(Scope_Stack
.Last
);
4785 SST
.Save_Scope_Suppress
:= Scope_Suppress
;
4786 SST
.Save_Local_Entity_Suppress
:= Local_Entity_Suppress
.Last
;
4788 if Scope_Stack
.Last
> Scope_Stack
.First
then
4789 SST
.Component_Alignment_Default
:= Scope_Stack
.Table
4790 (Scope_Stack
.Last
- 1).
4791 Component_Alignment_Default
;
4794 SST
.Last_Subprogram_Name
:= null;
4795 SST
.Is_Transient
:= False;
4796 SST
.Node_To_Be_Wrapped
:= Empty
;
4797 SST
.Pending_Freeze_Actions
:= No_List
;
4798 SST
.Actions_To_Be_Wrapped_Before
:= No_List
;
4799 SST
.Actions_To_Be_Wrapped_After
:= No_List
;
4800 SST
.First_Use_Clause
:= Empty
;
4801 SST
.Is_Active_Stack_Base
:= False;
4804 if Debug_Flag_W
then
4805 Write_Str
("--> new scope: ");
4806 Write_Name
(Chars
(Current_Scope
));
4807 Write_Str
(", Id=");
4808 Write_Int
(Int
(Current_Scope
));
4809 Write_Str
(", Depth=");
4810 Write_Int
(Int
(Scope_Stack
.Last
));
4814 -- Copy from Scope (S) the categorization flags to S, this is not
4815 -- done in case Scope (S) is Standard_Standard since propagation
4816 -- is from library unit entity inwards.
4818 if S
/= Standard_Standard
4819 and then Scope
(S
) /= Standard_Standard
4820 and then not Is_Child_Unit
(S
)
4824 if Nkind
(E
) not in N_Entity
then
4828 -- We only propagate inwards for library level entities,
4829 -- inner level subprograms do not inherit the categorization.
4831 if Is_Library_Level_Entity
(S
) then
4832 Set_Is_Preelaborated
(S
, Is_Preelaborated
(E
));
4833 Set_Is_Shared_Passive
(S
, Is_Shared_Passive
(E
));
4834 Set_Categorization_From_Scope
(E
=> S
, Scop
=> E
);
4843 procedure Pop_Scope
is
4844 SST
: Scope_Stack_Entry
renames Scope_Stack
.Table
(Scope_Stack
.Last
);
4847 if Debug_Flag_E
then
4851 Scope_Suppress
:= SST
.Save_Scope_Suppress
;
4852 Local_Entity_Suppress
.Set_Last
(SST
.Save_Local_Entity_Suppress
);
4854 if Debug_Flag_W
then
4855 Write_Str
("--> exiting scope: ");
4856 Write_Name
(Chars
(Current_Scope
));
4857 Write_Str
(", Depth=");
4858 Write_Int
(Int
(Scope_Stack
.Last
));
4862 End_Use_Clauses
(SST
.First_Use_Clause
);
4864 -- If the actions to be wrapped are still there they will get lost
4865 -- causing incomplete code to be generated. It is better to abort in
4866 -- this case (and we do the abort even with assertions off since the
4867 -- penalty is incorrect code generation)
4869 if SST
.Actions_To_Be_Wrapped_Before
/= No_List
4871 SST
.Actions_To_Be_Wrapped_After
/= No_List
4876 -- Free last subprogram name if allocated, and pop scope
4878 Free
(SST
.Last_Subprogram_Name
);
4879 Scope_Stack
.Decrement_Last
;
4882 ---------------------
4883 -- Premature_Usage --
4884 ---------------------
4886 procedure Premature_Usage
(N
: Node_Id
) is
4887 Kind
: constant Node_Kind
:= Nkind
(Parent
(Entity
(N
)));
4888 E
: Entity_Id
:= Entity
(N
);
4891 -- Within an instance, the analysis of the actual for a formal object
4892 -- does not see the name of the object itself. This is significant
4893 -- only if the object is an aggregate, where its analysis does not do
4894 -- any name resolution on component associations. (see 4717-008). In
4895 -- such a case, look for the visible homonym on the chain.
4898 and then Present
(Homonym
(E
))
4903 and then not In_Open_Scopes
(Scope
(E
))
4910 Set_Etype
(N
, Etype
(E
));
4915 if Kind
= N_Component_Declaration
then
4917 ("component&! cannot be used before end of record declaration", N
);
4919 elsif Kind
= N_Parameter_Specification
then
4921 ("formal parameter&! cannot be used before end of specification",
4924 elsif Kind
= N_Discriminant_Specification
then
4926 ("discriminant&! cannot be used before end of discriminant part",
4929 elsif Kind
= N_Procedure_Specification
4930 or else Kind
= N_Function_Specification
4933 ("subprogram&! cannot be used before end of its declaration",
4937 ("object& cannot be used before end of its declaration!", N
);
4939 end Premature_Usage
;
4941 ------------------------
4942 -- Present_System_Aux --
4943 ------------------------
4945 function Present_System_Aux
(N
: Node_Id
:= Empty
) return Boolean is
4948 Unum
: Unit_Number_Type
;
4953 function Find_System
(C_Unit
: Node_Id
) return Entity_Id
;
4954 -- Scan context clause of compilation unit to find a with_clause
4957 function Find_System
(C_Unit
: Node_Id
) return Entity_Id
is
4958 With_Clause
: Node_Id
;
4961 With_Clause
:= First
(Context_Items
(C_Unit
));
4963 while Present
(With_Clause
) loop
4964 if (Nkind
(With_Clause
) = N_With_Clause
4965 and then Chars
(Name
(With_Clause
)) = Name_System
)
4966 and then Comes_From_Source
(With_Clause
)
4977 -- Start of processing for Present_System_Aux
4980 -- The child unit may have been loaded and analyzed already.
4982 if Present
(System_Aux_Id
) then
4985 -- If no previous pragma for System.Aux, nothing to load
4987 elsif No
(System_Extend_Unit
) then
4990 -- Use the unit name given in the pragma to retrieve the unit.
4991 -- Verify that System itself appears in the context clause of the
4992 -- current compilation. If System is not present, an error will
4993 -- have been reported already.
4996 With_Sys
:= Find_System
(Cunit
(Current_Sem_Unit
));
4998 The_Unit
:= Unit
(Cunit
(Current_Sem_Unit
));
5001 and then (Nkind
(The_Unit
) = N_Package_Body
5002 or else (Nkind
(The_Unit
) = N_Subprogram_Body
5003 and then not Acts_As_Spec
(Cunit
(Current_Sem_Unit
))))
5005 With_Sys
:= Find_System
(Library_Unit
(Cunit
(Current_Sem_Unit
)));
5009 and then Present
(N
)
5011 -- If we are compiling a subunit, we need to examine its
5012 -- context as well (Current_Sem_Unit is the parent unit);
5014 The_Unit
:= Parent
(N
);
5016 while Nkind
(The_Unit
) /= N_Compilation_Unit
loop
5017 The_Unit
:= Parent
(The_Unit
);
5020 if Nkind
(Unit
(The_Unit
)) = N_Subunit
then
5021 With_Sys
:= Find_System
(The_Unit
);
5025 if No
(With_Sys
) then
5029 Loc
:= Sloc
(With_Sys
);
5030 Get_Name_String
(Chars
(Expression
(System_Extend_Unit
)));
5031 Name_Buffer
(8 .. Name_Len
+ 7) := Name_Buffer
(1 .. Name_Len
);
5032 Name_Buffer
(1 .. 7) := "system.";
5033 Name_Buffer
(Name_Len
+ 8) := '%';
5034 Name_Buffer
(Name_Len
+ 9) := 's';
5035 Name_Len
:= Name_Len
+ 9;
5036 Aux_Name
:= Name_Find
;
5040 (Load_Name
=> Aux_Name
,
5043 Error_Node
=> With_Sys
);
5045 if Unum
/= No_Unit
then
5046 Semantics
(Cunit
(Unum
));
5048 Defining_Entity
(Specification
(Unit
(Cunit
(Unum
))));
5050 Withn
:= Make_With_Clause
(Loc
,
5052 Make_Expanded_Name
(Loc
,
5053 Chars
=> Chars
(System_Aux_Id
),
5055 New_Reference_To
(Scope
(System_Aux_Id
), Loc
),
5057 New_Reference_To
(System_Aux_Id
, Loc
)));
5059 Set_Entity
(Name
(Withn
), System_Aux_Id
);
5061 Set_Library_Unit
(Withn
, Cunit
(Unum
));
5062 Set_Corresponding_Spec
(Withn
, System_Aux_Id
);
5063 Set_First_Name
(Withn
, True);
5064 Set_Implicit_With
(Withn
, True);
5066 Insert_After
(With_Sys
, Withn
);
5067 Mark_Rewrite_Insertion
(Withn
);
5068 Set_Context_Installed
(Withn
);
5072 -- Here if unit load failed
5075 Error_Msg_Name_1
:= Name_System
;
5076 Error_Msg_Name_2
:= Chars
(Expression
(System_Extend_Unit
));
5078 ("extension package `%.%` does not exist",
5079 Opt
.System_Extend_Unit
);
5083 end Present_System_Aux
;
5085 -------------------------
5086 -- Restore_Scope_Stack --
5087 -------------------------
5089 procedure Restore_Scope_Stack
(Handle_Use
: Boolean := True) is
5092 Comp_Unit
: Node_Id
;
5093 In_Child
: Boolean := False;
5094 Full_Vis
: Boolean := True;
5095 SS_Last
: constant Int
:= Scope_Stack
.Last
;
5098 -- Restore visibility of previous scope stack, if any.
5100 for J
in reverse 0 .. Scope_Stack
.Last
loop
5101 exit when Scope_Stack
.Table
(J
).Entity
= Standard_Standard
5102 or else No
(Scope_Stack
.Table
(J
).Entity
);
5104 S
:= Scope_Stack
.Table
(J
).Entity
;
5106 if not Is_Hidden_Open_Scope
(S
) then
5108 -- If the parent scope is hidden, its entities are hidden as
5109 -- well, unless the entity is the instantiation currently
5112 if not Is_Hidden_Open_Scope
(Scope
(S
))
5113 or else not Analyzed
(Parent
(S
))
5114 or else Scope
(S
) = Standard_Standard
5116 Set_Is_Immediately_Visible
(S
, True);
5119 E
:= First_Entity
(S
);
5121 while Present
(E
) loop
5122 if Is_Child_Unit
(E
) then
5123 Set_Is_Immediately_Visible
(E
,
5124 Is_Visible_Child_Unit
(E
) or else In_Open_Scopes
(E
));
5126 Set_Is_Immediately_Visible
(E
, True);
5131 if not Full_Vis
then
5132 exit when E
= First_Private_Entity
(S
);
5136 -- The visibility of child units (siblings of current compilation)
5137 -- must be restored in any case. Their declarations may appear
5138 -- after the private part of the parent.
5141 and then Present
(E
)
5143 while Present
(E
) loop
5144 if Is_Child_Unit
(E
) then
5145 Set_Is_Immediately_Visible
(E
,
5146 Is_Visible_Child_Unit
(E
) or else In_Open_Scopes
(E
));
5154 if Is_Child_Unit
(S
)
5155 and not In_Child
-- check only for current unit.
5159 -- restore visibility of parents according to whether the child
5160 -- is private and whether we are in its visible part.
5162 Comp_Unit
:= Parent
(Unit_Declaration_Node
(S
));
5164 if Nkind
(Comp_Unit
) = N_Compilation_Unit
5165 and then Private_Present
(Comp_Unit
)
5169 elsif (Ekind
(S
) = E_Package
5170 or else Ekind
(S
) = E_Generic_Package
)
5171 and then (In_Private_Part
(S
)
5172 or else In_Package_Body
(S
))
5176 elsif (Ekind
(S
) = E_Procedure
5177 or else Ekind
(S
) = E_Function
)
5178 and then Has_Completion
(S
)
5189 if SS_Last
>= Scope_Stack
.First
5190 and then Scope_Stack
.Table
(SS_Last
).Entity
/= Standard_Standard
5193 Install_Use_Clauses
(Scope_Stack
.Table
(SS_Last
).First_Use_Clause
);
5195 end Restore_Scope_Stack
;
5197 ----------------------
5198 -- Save_Scope_Stack --
5199 ----------------------
5201 procedure Save_Scope_Stack
(Handle_Use
: Boolean := True) is
5204 SS_Last
: constant Int
:= Scope_Stack
.Last
;
5207 if SS_Last
>= Scope_Stack
.First
5208 and then Scope_Stack
.Table
(SS_Last
).Entity
/= Standard_Standard
5211 End_Use_Clauses
(Scope_Stack
.Table
(SS_Last
).First_Use_Clause
);
5214 -- If the call is from within a compilation unit, as when
5215 -- called from Rtsfind, make current entries in scope stack
5216 -- invisible while we analyze the new unit.
5218 for J
in reverse 0 .. SS_Last
loop
5219 exit when Scope_Stack
.Table
(J
).Entity
= Standard_Standard
5220 or else No
(Scope_Stack
.Table
(J
).Entity
);
5222 S
:= Scope_Stack
.Table
(J
).Entity
;
5223 Set_Is_Immediately_Visible
(S
, False);
5224 E
:= First_Entity
(S
);
5226 while Present
(E
) loop
5227 Set_Is_Immediately_Visible
(E
, False);
5233 end Save_Scope_Stack
;
5239 procedure Set_Use
(L
: List_Id
) is
5241 Pack_Name
: Node_Id
;
5249 while Present
(Decl
) loop
5250 if Nkind
(Decl
) = N_Use_Package_Clause
then
5251 Chain_Use_Clause
(Decl
);
5252 Pack_Name
:= First
(Names
(Decl
));
5254 while Present
(Pack_Name
) loop
5255 Pack
:= Entity
(Pack_Name
);
5257 if Ekind
(Pack
) = E_Package
5258 and then Applicable_Use
(Pack_Name
)
5260 Use_One_Package
(Pack
, Decl
);
5266 elsif Nkind
(Decl
) = N_Use_Type_Clause
then
5267 Chain_Use_Clause
(Decl
);
5268 Id
:= First
(Subtype_Marks
(Decl
));
5270 while Present
(Id
) loop
5271 if Entity
(Id
) /= Any_Type
then
5284 ---------------------
5285 -- Use_One_Package --
5286 ---------------------
5288 procedure Use_One_Package
(P
: Entity_Id
; N
: Node_Id
) is
5291 Current_Instance
: Entity_Id
:= Empty
;
5295 if Ekind
(P
) /= E_Package
then
5301 -- Ada0Y (AI-50217): Check restriction.
5303 if From_With_Type
(P
) then
5304 Error_Msg_N
("limited withed package cannot appear in use clause", N
);
5307 -- Find enclosing instance, if any.
5310 Current_Instance
:= Current_Scope
;
5312 while not Is_Generic_Instance
(Current_Instance
) loop
5313 Current_Instance
:= Scope
(Current_Instance
);
5316 if No
(Hidden_By_Use_Clause
(N
)) then
5317 Set_Hidden_By_Use_Clause
(N
, New_Elmt_List
);
5321 -- If unit is a package renaming, indicate that the renamed
5322 -- package is also in use (the flags on both entities must
5323 -- remain consistent, and a subsequent use of either of them
5324 -- should be recognized as redundant).
5326 if Present
(Renamed_Object
(P
)) then
5327 Set_In_Use
(Renamed_Object
(P
));
5328 Real_P
:= Renamed_Object
(P
);
5333 -- Loop through entities in one package making them potentially
5336 Id
:= First_Entity
(P
);
5338 and then Id
/= First_Private_Entity
(P
)
5340 Prev
:= Current_Entity
(Id
);
5342 while Present
(Prev
) loop
5343 if Is_Immediately_Visible
(Prev
)
5344 and then (not Is_Overloadable
(Prev
)
5345 or else not Is_Overloadable
(Id
)
5346 or else (Type_Conformant
(Id
, Prev
)))
5348 if No
(Current_Instance
) then
5350 -- Potentially use-visible entity remains hidden
5352 goto Next_Usable_Entity
;
5354 -- A use clause within an instance hides outer global
5355 -- entities, which are not used to resolve local entities
5356 -- in the instance. Note that the predefined entities in
5357 -- Standard could not have been hidden in the generic by
5358 -- a use clause, and therefore remain visible. Other
5359 -- compilation units whose entities appear in Standard must
5360 -- be hidden in an instance.
5362 -- To determine whether an entity is external to the instance
5363 -- we compare the scope depth of its scope with that of the
5364 -- current instance. However, a generic actual of a subprogram
5365 -- instance is declared in the wrapper package but will not be
5366 -- hidden by a use-visible entity.
5368 elsif not Is_Hidden
(Id
)
5369 and then not Is_Wrapper_Package
(Scope
(Prev
))
5370 and then Scope_Depth
(Scope
(Prev
)) <
5371 Scope_Depth
(Current_Instance
)
5372 and then (Scope
(Prev
) /= Standard_Standard
5373 or else Sloc
(Prev
) > Standard_Location
)
5375 Set_Is_Potentially_Use_Visible
(Id
);
5376 Set_Is_Immediately_Visible
(Prev
, False);
5377 Append_Elmt
(Prev
, Hidden_By_Use_Clause
(N
));
5380 -- A user-defined operator is not use-visible if the
5381 -- predefined operator for the type is immediately visible,
5382 -- which is the case if the type of the operand is in an open
5383 -- scope. This does not apply to user-defined operators that
5384 -- have operands of different types, because the predefined
5385 -- mixed mode operations (multiplication and division) apply to
5386 -- universal types and do not hide anything.
5388 elsif Ekind
(Prev
) = E_Operator
5389 and then Operator_Matches_Spec
(Prev
, Id
)
5390 and then In_Open_Scopes
5391 (Scope
(Base_Type
(Etype
(First_Formal
(Id
)))))
5392 and then (No
(Next_Formal
(First_Formal
(Id
)))
5393 or else Etype
(First_Formal
(Id
))
5394 = Etype
(Next_Formal
(First_Formal
(Id
)))
5395 or else Chars
(Prev
) = Name_Op_Expon
)
5397 goto Next_Usable_Entity
;
5400 Prev
:= Homonym
(Prev
);
5403 -- On exit, we know entity is not hidden, unless it is private.
5405 if not Is_Hidden
(Id
)
5406 and then ((not Is_Child_Unit
(Id
))
5407 or else Is_Visible_Child_Unit
(Id
))
5409 Set_Is_Potentially_Use_Visible
(Id
);
5411 if Is_Private_Type
(Id
)
5412 and then Present
(Full_View
(Id
))
5414 Set_Is_Potentially_Use_Visible
(Full_View
(Id
));
5418 <<Next_Usable_Entity
>>
5422 -- Child units are also made use-visible by a use clause, but they
5423 -- may appear after all visible declarations in the parent entity list.
5425 while Present
(Id
) loop
5427 if Is_Child_Unit
(Id
)
5428 and then Is_Visible_Child_Unit
(Id
)
5430 Set_Is_Potentially_Use_Visible
(Id
);
5436 if Chars
(Real_P
) = Name_System
5437 and then Scope
(Real_P
) = Standard_Standard
5438 and then Present_System_Aux
(N
)
5440 Use_One_Package
(System_Aux_Id
, N
);
5443 end Use_One_Package
;
5449 procedure Use_One_Type
(Id
: Node_Id
) is
5455 -- It is the type determined by the subtype mark (8.4(8)) whose
5456 -- operations become potentially use-visible.
5458 T
:= Base_Type
(Entity
(Id
));
5463 or else Is_Potentially_Use_Visible
(T
)
5464 or else In_Use
(Scope
(T
)));
5466 if In_Open_Scopes
(Scope
(T
)) then
5469 -- If the subtype mark designates a subtype in a different package,
5470 -- we have to check that the parent type is visible, otherwise the
5471 -- use type clause is a noop. Not clear how to do that???
5473 elsif not Redundant_Use
(Id
) then
5475 Op_List
:= Collect_Primitive_Operations
(T
);
5476 Elmt
:= First_Elmt
(Op_List
);
5478 while Present
(Elmt
) loop
5480 if (Nkind
(Node
(Elmt
)) = N_Defining_Operator_Symbol
5481 or else Chars
(Node
(Elmt
)) in Any_Operator_Name
)
5482 and then not Is_Hidden
(Node
(Elmt
))
5484 Set_Is_Potentially_Use_Visible
(Node
(Elmt
));
5496 procedure Write_Info
is
5497 Id
: Entity_Id
:= First_Entity
(Current_Scope
);
5500 -- No point in dumping standard entities
5502 if Current_Scope
= Standard_Standard
then
5506 Write_Str
("========================================================");
5508 Write_Str
(" Defined Entities in ");
5509 Write_Name
(Chars
(Current_Scope
));
5511 Write_Str
("========================================================");
5515 Write_Str
("-- none --");
5519 while Present
(Id
) loop
5520 Write_Entity_Info
(Id
, " ");
5525 if Scope
(Current_Scope
) = Standard_Standard
then
5527 -- Print information on the current unit itself
5529 Write_Entity_Info
(Current_Scope
, " ");
5539 procedure Write_Scopes
is
5543 for J
in reverse 1 .. Scope_Stack
.Last
loop
5544 S
:= Scope_Stack
.Table
(J
).Entity
;
5545 Write_Int
(Int
(S
));
5546 Write_Str
(" === ");
5547 Write_Name
(Chars
(S
));