1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2015, 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 3, or (at your option) any later ver- --
14 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
15 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
16 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
17 -- for more details. You should have received a copy of the GNU General --
18 -- Public License distributed with GNAT; see file COPYING3. If not, go to --
19 -- http://www.gnu.org/licenses for a complete copy of the license. --
21 -- GNAT was originally developed by the GNAT team at New York University. --
22 -- Extensive contributions were provided by Ada Core Technologies Inc. --
24 ------------------------------------------------------------------------------
26 with Atree; use Atree;
27 with Debug; use Debug;
28 with Einfo; use Einfo;
29 with Elists; use Elists;
30 with Errout; use Errout;
31 with Exp_Disp; use Exp_Disp;
32 with Exp_Tss; use Exp_Tss;
33 with Exp_Util; use Exp_Util;
34 with Fname; use Fname;
35 with Freeze; use Freeze;
36 with Ghost; use Ghost;
37 with Impunit; use Impunit;
39 with Lib.Load; use Lib.Load;
40 with Lib.Xref; use Lib.Xref;
41 with Namet; use Namet;
42 with Namet.Sp; use Namet.Sp;
43 with Nlists; use Nlists;
44 with Nmake; use Nmake;
46 with Output; use Output;
47 with Restrict; use Restrict;
48 with Rident; use Rident;
49 with Rtsfind; use Rtsfind;
51 with Sem_Aux; use Sem_Aux;
52 with Sem_Cat; use Sem_Cat;
53 with Sem_Ch3; use Sem_Ch3;
54 with Sem_Ch4; use Sem_Ch4;
55 with Sem_Ch6; use Sem_Ch6;
56 with Sem_Ch12; use Sem_Ch12;
57 with Sem_Ch13; use Sem_Ch13;
58 with Sem_Dim; use Sem_Dim;
59 with Sem_Disp; use Sem_Disp;
60 with Sem_Dist; use Sem_Dist;
61 with Sem_Eval; use Sem_Eval;
62 with Sem_Res; use Sem_Res;
63 with Sem_Util; use Sem_Util;
64 with Sem_Type; use Sem_Type;
65 with Stand; use Stand;
66 with Sinfo; use Sinfo;
67 with Sinfo.CN; use Sinfo.CN;
68 with Snames; use Snames;
69 with Style; use Style;
71 with Targparm; use Targparm;
72 with Tbuild; use Tbuild;
73 with Uintp; use Uintp;
75 package body Sem_Ch8 is
77 ------------------------------------
78 -- Visibility and Name Resolution --
79 ------------------------------------
81 -- This package handles name resolution and the collection of possible
82 -- interpretations for overloaded names, prior to overload resolution.
84 -- Name resolution is the process that establishes a mapping between source
85 -- identifiers and the entities they denote at each point in the program.
86 -- Each entity is represented by a defining occurrence. Each identifier
87 -- that denotes an entity points to the corresponding defining occurrence.
88 -- This is the entity of the applied occurrence. Each occurrence holds
89 -- an index into the names table, where source identifiers are stored.
91 -- Each entry in the names table for an identifier or designator uses the
92 -- Info pointer to hold a link to the currently visible entity that has
93 -- this name (see subprograms Get_Name_Entity_Id and Set_Name_Entity_Id
94 -- in package Sem_Util). The visibility is initialized at the beginning of
95 -- semantic processing to make entities in package Standard immediately
96 -- visible. The visibility table is used in a more subtle way when
97 -- compiling subunits (see below).
99 -- Entities that have the same name (i.e. homonyms) are chained. In the
100 -- case of overloaded entities, this chain holds all the possible meanings
101 -- of a given identifier. The process of overload resolution uses type
102 -- information to select from this chain the unique meaning of a given
105 -- Entities are also chained in their scope, through the Next_Entity link.
106 -- As a consequence, the name space is organized as a sparse matrix, where
107 -- each row corresponds to a scope, and each column to a source identifier.
108 -- Open scopes, that is to say scopes currently being compiled, have their
109 -- corresponding rows of entities in order, innermost scope first.
111 -- The scopes of packages that are mentioned in context clauses appear in
112 -- no particular order, interspersed among open scopes. This is because
113 -- in the course of analyzing the context of a compilation, a package
114 -- declaration is first an open scope, and subsequently an element of the
115 -- context. If subunits or child units are present, a parent unit may
116 -- appear under various guises at various times in the compilation.
118 -- When the compilation of the innermost scope is complete, the entities
119 -- defined therein are no longer visible. If the scope is not a package
120 -- declaration, these entities are never visible subsequently, and can be
121 -- removed from visibility chains. If the scope is a package declaration,
122 -- its visible declarations may still be accessible. Therefore the entities
123 -- defined in such a scope are left on the visibility chains, and only
124 -- their visibility (immediately visibility or potential use-visibility)
127 -- The ordering of homonyms on their chain does not necessarily follow
128 -- the order of their corresponding scopes on the scope stack. For
129 -- example, if package P and the enclosing scope both contain entities
130 -- named E, then when compiling the package body the chain for E will
131 -- hold the global entity first, and the local one (corresponding to
132 -- the current inner scope) next. As a result, name resolution routines
133 -- do not assume any relative ordering of the homonym chains, either
134 -- for scope nesting or to order of appearance of context clauses.
136 -- When compiling a child unit, entities in the parent scope are always
137 -- immediately visible. When compiling the body of a child unit, private
138 -- entities in the parent must also be made immediately visible. There
139 -- are separate routines to make the visible and private declarations
140 -- visible at various times (see package Sem_Ch7).
142 -- +--------+ +-----+
143 -- | In use |-------->| EU1 |-------------------------->
144 -- +--------+ +-----+
146 -- +--------+ +-----+ +-----+
147 -- | Stand. |---------------->| ES1 |--------------->| ES2 |--->
148 -- +--------+ +-----+ +-----+
150 -- +---------+ | +-----+
151 -- | with'ed |------------------------------>| EW2 |--->
152 -- +---------+ | +-----+
154 -- +--------+ +-----+ +-----+
155 -- | Scope2 |---------------->| E12 |--------------->| E22 |--->
156 -- +--------+ +-----+ +-----+
158 -- +--------+ +-----+ +-----+
159 -- | Scope1 |---------------->| E11 |--------------->| E12 |--->
160 -- +--------+ +-----+ +-----+
164 -- | | with'ed |----------------------------------------->
168 -- (innermost first) | |
169 -- +----------------------------+
170 -- Names table => | Id1 | | | | Id2 |
171 -- +----------------------------+
173 -- Name resolution must deal with several syntactic forms: simple names,
174 -- qualified names, indexed names, and various forms of calls.
176 -- Each identifier points to an entry in the names table. The resolution
177 -- of a simple name consists in traversing the homonym chain, starting
178 -- from the names table. If an entry is immediately visible, it is the one
179 -- designated by the identifier. If only potentially use-visible entities
180 -- are on the chain, we must verify that they do not hide each other. If
181 -- the entity we find is overloadable, we collect all other overloadable
182 -- entities on the chain as long as they are not hidden.
184 -- To resolve expanded names, we must find the entity at the intersection
185 -- of the entity chain for the scope (the prefix) and the homonym chain
186 -- for the selector. In general, homonym chains will be much shorter than
187 -- entity chains, so it is preferable to start from the names table as
188 -- well. If the entity found is overloadable, we must collect all other
189 -- interpretations that are defined in the scope denoted by the prefix.
191 -- For records, protected types, and tasks, their local entities are
192 -- removed from visibility chains on exit from the corresponding scope.
193 -- From the outside, these entities are always accessed by selected
194 -- notation, and the entity chain for the record type, protected type,
195 -- etc. is traversed sequentially in order to find the designated entity.
197 -- The discriminants of a type and the operations of a protected type or
198 -- task are unchained on exit from the first view of the type, (such as
199 -- a private or incomplete type declaration, or a protected type speci-
200 -- fication) and re-chained when compiling the second view.
202 -- In the case of operators, we do not make operators on derived types
203 -- explicit. As a result, the notation P."+" may denote either a user-
204 -- defined function with name "+", or else an implicit declaration of the
205 -- operator "+" in package P. The resolution of expanded names always
206 -- tries to resolve an operator name as such an implicitly defined entity,
207 -- in addition to looking for explicit declarations.
209 -- All forms of names that denote entities (simple names, expanded names,
210 -- character literals in some cases) have a Entity attribute, which
211 -- identifies the entity denoted by the name.
213 ---------------------
214 -- The Scope Stack --
215 ---------------------
217 -- The Scope stack keeps track of the scopes currently been compiled.
218 -- Every entity that contains declarations (including records) is placed
219 -- on the scope stack while it is being processed, and removed at the end.
220 -- Whenever a non-package scope is exited, the entities defined therein
221 -- are removed from the visibility table, so that entities in outer scopes
222 -- become visible (see previous description). On entry to Sem, the scope
223 -- stack only contains the package Standard. As usual, subunits complicate
224 -- this picture ever so slightly.
226 -- The Rtsfind mechanism can force a call to Semantics while another
227 -- compilation is in progress. The unit retrieved by Rtsfind must be
228 -- compiled in its own context, and has no access to the visibility of
229 -- the unit currently being compiled. The procedures Save_Scope_Stack and
230 -- Restore_Scope_Stack make entities in current open scopes invisible
231 -- before compiling the retrieved unit, and restore the compilation
232 -- environment afterwards.
234 ------------------------
235 -- Compiling subunits --
236 ------------------------
238 -- Subunits must be compiled in the environment of the corresponding stub,
239 -- that is to say with the same visibility into the parent (and its
240 -- context) that is available at the point of the stub declaration, but
241 -- with the additional visibility provided by the context clause of the
242 -- subunit itself. As a result, compilation of a subunit forces compilation
243 -- of the parent (see description in lib-). At the point of the stub
244 -- declaration, Analyze is called recursively to compile the proper body of
245 -- the subunit, but without reinitializing the names table, nor the scope
246 -- stack (i.e. standard is not pushed on the stack). In this fashion the
247 -- context of the subunit is added to the context of the parent, and the
248 -- subunit is compiled in the correct environment. Note that in the course
249 -- of processing the context of a subunit, Standard will appear twice on
250 -- the scope stack: once for the parent of the subunit, and once for the
251 -- unit in the context clause being compiled. However, the two sets of
252 -- entities are not linked by homonym chains, so that the compilation of
253 -- any context unit happens in a fresh visibility environment.
255 -------------------------------
256 -- Processing of USE Clauses --
257 -------------------------------
259 -- Every defining occurrence has a flag indicating if it is potentially use
260 -- visible. Resolution of simple names examines this flag. The processing
261 -- of use clauses consists in setting this flag on all visible entities
262 -- defined in the corresponding package. On exit from the scope of the use
263 -- clause, the corresponding flag must be reset. However, a package may
264 -- appear in several nested use clauses (pathological but legal, alas)
265 -- which forces us to use a slightly more involved scheme:
267 -- a) The defining occurrence for a package holds a flag -In_Use- to
268 -- indicate that it is currently in the scope of a use clause. If a
269 -- redundant use clause is encountered, then the corresponding occurrence
270 -- of the package name is flagged -Redundant_Use-.
272 -- b) On exit from a scope, the use clauses in its declarative part are
273 -- scanned. The visibility flag is reset in all entities declared in
274 -- package named in a use clause, as long as the package is not flagged
275 -- as being in a redundant use clause (in which case the outer use
276 -- clause is still in effect, and the direct visibility of its entities
277 -- must be retained).
279 -- Note that entities are not removed from their homonym chains on exit
280 -- from the package specification. A subsequent use clause does not need
281 -- to rechain the visible entities, but only to establish their direct
284 -----------------------------------
285 -- Handling private declarations --
286 -----------------------------------
288 -- The principle that each entity has a single defining occurrence clashes
289 -- with the presence of two separate definitions for private types: the
290 -- first is the private type declaration, and second is the full type
291 -- declaration. It is important that all references to the type point to
292 -- the same defining occurrence, namely the first one. To enforce the two
293 -- separate views of the entity, the corresponding information is swapped
294 -- between the two declarations. Outside of the package, the defining
295 -- occurrence only contains the private declaration information, while in
296 -- the private part and the body of the package the defining occurrence
297 -- contains the full declaration. To simplify the swap, the defining
298 -- occurrence that currently holds the private declaration points to the
299 -- full declaration. During semantic processing the defining occurrence
300 -- also points to a list of private dependents, that is to say access types
301 -- or composite types whose designated types or component types are
302 -- subtypes or derived types of the private type in question. After the
303 -- full declaration has been seen, the private dependents are updated to
304 -- indicate that they have full definitions.
306 ------------------------------------
307 -- Handling of Undefined Messages --
308 ------------------------------------
310 -- In normal mode, only the first use of an undefined identifier generates
311 -- a message. The table Urefs is used to record error messages that have
312 -- been issued so that second and subsequent ones do not generate further
313 -- messages. However, the second reference causes text to be added to the
314 -- original undefined message noting "(more references follow)". The
315 -- full error list option (-gnatf) forces messages to be generated for
316 -- every reference and disconnects the use of this table.
318 type Uref_Entry is record
320 -- Node for identifier for which original message was posted. The
321 -- Chars field of this identifier is used to detect later references
322 -- to the same identifier.
325 -- Records error message Id of original undefined message. Reset to
326 -- No_Error_Msg after the second occurrence, where it is used to add
327 -- text to the original message as described above.
330 -- Set if the message is not visible rather than undefined
333 -- Records location of error message. Used to make sure that we do
334 -- not consider a, b : undefined as two separate instances, which
335 -- would otherwise happen, since the parser converts this sequence
336 -- to a : undefined; b : undefined.
340 package Urefs is new Table.Table (
341 Table_Component_Type => Uref_Entry,
342 Table_Index_Type => Nat,
343 Table_Low_Bound => 1,
345 Table_Increment => 100,
346 Table_Name => "Urefs");
348 Candidate_Renaming : Entity_Id;
349 -- Holds a candidate interpretation that appears in a subprogram renaming
350 -- declaration and does not match the given specification, but matches at
351 -- least on the first formal. Allows better error message when given
352 -- specification omits defaulted parameters, a common error.
354 -----------------------
355 -- Local Subprograms --
356 -----------------------
358 procedure Analyze_Generic_Renaming
361 -- Common processing for all three kinds of generic renaming declarations.
362 -- Enter new name and indicate that it renames the generic unit.
364 procedure Analyze_Renamed_Character
368 -- Renamed entity is given by a character literal, which must belong
369 -- to the return type of the new entity. Is_Body indicates whether the
370 -- declaration is a renaming_as_body. If the original declaration has
371 -- already been frozen (because of an intervening body, e.g.) the body of
372 -- the function must be built now. The same applies to the following
373 -- various renaming procedures.
375 procedure Analyze_Renamed_Dereference
379 -- Renamed entity is given by an explicit dereference. Prefix must be a
380 -- conformant access_to_subprogram type.
382 procedure Analyze_Renamed_Entry
386 -- If the renamed entity in a subprogram renaming is an entry or protected
387 -- subprogram, build a body for the new entity whose only statement is a
388 -- call to the renamed entity.
390 procedure Analyze_Renamed_Family_Member
394 -- Used when the renamed entity is an indexed component. The prefix must
395 -- denote an entry family.
397 procedure Analyze_Renamed_Primitive_Operation
401 -- If the renamed entity in a subprogram renaming is a primitive operation
402 -- or a class-wide operation in prefix form, save the target object,
403 -- which must be added to the list of actuals in any subsequent call.
404 -- The renaming operation is intrinsic because the compiler must in
405 -- fact generate a wrapper for it (6.3.1 (10 1/2)).
407 function Applicable_Use (Pack_Name : Node_Id) return Boolean;
408 -- Common code to Use_One_Package and Set_Use, to determine whether use
409 -- clause must be processed. Pack_Name is an entity name that references
410 -- the package in question.
412 procedure Attribute_Renaming (N : Node_Id);
413 -- Analyze renaming of attribute as subprogram. The renaming declaration N
414 -- is rewritten as a subprogram body that returns the attribute reference
415 -- applied to the formals of the function.
417 procedure Set_Entity_Or_Discriminal (N : Node_Id; E : Entity_Id);
418 -- Set Entity, with style check if need be. For a discriminant reference,
419 -- replace by the corresponding discriminal, i.e. the parameter of the
420 -- initialization procedure that corresponds to the discriminant.
422 procedure Check_Frozen_Renaming (N : Node_Id; Subp : Entity_Id);
423 -- A renaming_as_body may occur after the entity of the original decla-
424 -- ration has been frozen. In that case, the body of the new entity must
425 -- be built now, because the usual mechanism of building the renamed
426 -- body at the point of freezing will not work. Subp is the subprogram
427 -- for which N provides the Renaming_As_Body.
429 procedure Check_In_Previous_With_Clause
432 -- N is a use_package clause and Nam the package name, or N is a use_type
433 -- clause and Nam is the prefix of the type name. In either case, verify
434 -- that the package is visible at that point in the context: either it
435 -- appears in a previous with_clause, or because it is a fully qualified
436 -- name and the root ancestor appears in a previous with_clause.
438 procedure Check_Library_Unit_Renaming (N : Node_Id; Old_E : Entity_Id);
439 -- Verify that the entity in a renaming declaration that is a library unit
440 -- is itself a library unit and not a nested unit or subunit. Also check
441 -- that if the renaming is a child unit of a generic parent, then the
442 -- renamed unit must also be a child unit of that parent. Finally, verify
443 -- that a renamed generic unit is not an implicit child declared within
444 -- an instance of the parent.
446 procedure Chain_Use_Clause (N : Node_Id);
447 -- Chain use clause onto list of uses clauses headed by First_Use_Clause in
448 -- the proper scope table entry. This is usually the current scope, but it
449 -- will be an inner scope when installing the use clauses of the private
450 -- declarations of a parent unit prior to compiling the private part of a
451 -- child unit. This chain is traversed when installing/removing use clauses
452 -- when compiling a subunit or instantiating a generic body on the fly,
453 -- when it is necessary to save and restore full environments.
455 function Enclosing_Instance return Entity_Id;
456 -- In an instance nested within another one, several semantic checks are
457 -- unnecessary because the legality of the nested instance has been checked
458 -- in the enclosing generic unit. This applies in particular to legality
459 -- checks on actuals for formal subprograms of the inner instance, which
460 -- are checked as subprogram renamings, and may be complicated by confusion
461 -- in private/full views. This function returns the instance enclosing the
462 -- current one if there is such, else it returns Empty.
464 -- If the renaming determines the entity for the default of a formal
465 -- subprogram nested within another instance, choose the innermost
466 -- candidate. This is because if the formal has a box, and we are within
467 -- an enclosing instance where some candidate interpretations are local
468 -- to this enclosing instance, we know that the default was properly
469 -- resolved when analyzing the generic, so we prefer the local
470 -- candidates to those that are external. This is not always the case
471 -- but is a reasonable heuristic on the use of nested generics. The
472 -- proper solution requires a full renaming model.
474 function Has_Implicit_Character_Literal (N : Node_Id) return Boolean;
475 -- Find a type derived from Character or Wide_Character in the prefix of N.
476 -- Used to resolved qualified names whose selector is a character literal.
478 function Has_Private_With (E : Entity_Id) return Boolean;
479 -- Ada 2005 (AI-262): Determines if the current compilation unit has a
480 -- private with on E.
482 procedure Find_Expanded_Name (N : Node_Id);
483 -- The input is a selected component known to be an expanded name. Verify
484 -- legality of selector given the scope denoted by prefix, and change node
485 -- N into a expanded name with a properly set Entity field.
487 function Find_Renamed_Entity
491 Is_Actual : Boolean := False) return Entity_Id;
492 -- Find the renamed entity that corresponds to the given parameter profile
493 -- in a subprogram renaming declaration. The renamed entity may be an
494 -- operator, a subprogram, an entry, or a protected operation. Is_Actual
495 -- indicates that the renaming is the one generated for an actual subpro-
496 -- gram in an instance, for which special visibility checks apply.
498 function Has_Implicit_Operator (N : Node_Id) return Boolean;
499 -- N is an expanded name whose selector is an operator name (e.g. P."+").
500 -- declarative part contains an implicit declaration of an operator if it
501 -- has a declaration of a type to which one of the predefined operators
502 -- apply. The existence of this routine is an implementation artifact. A
503 -- more straightforward but more space-consuming choice would be to make
504 -- all inherited operators explicit in the symbol table.
506 procedure Inherit_Renamed_Profile (New_S : Entity_Id; Old_S : Entity_Id);
507 -- A subprogram defined by a renaming declaration inherits the parameter
508 -- profile of the renamed entity. The subtypes given in the subprogram
509 -- specification are discarded and replaced with those of the renamed
510 -- subprogram, which are then used to recheck the default values.
512 function Is_Appropriate_For_Record (T : Entity_Id) return Boolean;
513 -- Prefix is appropriate for record if it is of a record type, or an access
516 function Is_Appropriate_For_Entry_Prefix (T : Entity_Id) return Boolean;
517 -- True if it is of a task type, a protected type, or else an access to one
520 procedure Note_Redundant_Use (Clause : Node_Id);
521 -- Mark the name in a use clause as redundant if the corresponding entity
522 -- is already use-visible. Emit a warning if the use clause comes from
523 -- source and the proper warnings are enabled.
525 procedure Premature_Usage (N : Node_Id);
526 -- Diagnose usage of an entity before it is visible
528 procedure Use_One_Package (P : Entity_Id; N : Node_Id);
529 -- Make visible entities declared in package P potentially use-visible
530 -- in the current context. Also used in the analysis of subunits, when
531 -- re-installing use clauses of parent units. N is the use_clause that
532 -- names P (and possibly other packages).
534 procedure Use_One_Type (Id : Node_Id; Installed : Boolean := False);
535 -- Id is the subtype mark from a use type clause. This procedure makes
536 -- the primitive operators of the type potentially use-visible. The
537 -- boolean flag Installed indicates that the clause is being reinstalled
538 -- after previous analysis, and primitive operations are already chained
539 -- on the Used_Operations list of the clause.
541 procedure Write_Info;
542 -- Write debugging information on entities declared in current scope
544 --------------------------------
545 -- Analyze_Exception_Renaming --
546 --------------------------------
548 -- The language only allows a single identifier, but the tree holds an
549 -- identifier list. The parser has already issued an error message if
550 -- there is more than one element in the list.
552 procedure Analyze_Exception_Renaming (N : Node_Id) is
553 Id : constant Node_Id := Defining_Identifier (N);
554 Nam : constant Node_Id := Name (N);
557 -- The exception renaming declaration may be subject to pragma Ghost
558 -- with policy Ignore. Set the mode now to ensure that any nodes
559 -- generated during analysis and expansion are properly flagged as
563 Check_SPARK_05_Restriction ("exception renaming is not allowed", N);
568 Set_Ekind (Id, E_Exception);
569 Set_Etype (Id, Standard_Exception_Type);
570 Set_Is_Pure (Id, Is_Pure (Current_Scope));
572 if not Is_Entity_Name (Nam)
573 or else Ekind (Entity (Nam)) /= E_Exception
575 Error_Msg_N ("invalid exception name in renaming", Nam);
577 if Present (Renamed_Object (Entity (Nam))) then
578 Set_Renamed_Object (Id, Renamed_Object (Entity (Nam)));
580 Set_Renamed_Object (Id, Entity (Nam));
583 -- An exception renaming is Ghost if the renamed entity is Ghost or
584 -- the construct appears within a Ghost scope.
586 if Is_Ghost_Entity (Entity (Nam)) or else Ghost_Mode > None then
587 Set_Is_Ghost_Entity (Id);
591 -- Implementation-defined aspect specifications can appear in a renaming
592 -- declaration, but not language-defined ones. The call to procedure
593 -- Analyze_Aspect_Specifications will take care of this error check.
595 if Has_Aspects (N) then
596 Analyze_Aspect_Specifications (N, Id);
598 end Analyze_Exception_Renaming;
600 ---------------------------
601 -- Analyze_Expanded_Name --
602 ---------------------------
604 procedure Analyze_Expanded_Name (N : Node_Id) is
606 -- If the entity pointer is already set, this is an internal node, or a
607 -- node that is analyzed more than once, after a tree modification. In
608 -- such a case there is no resolution to perform, just set the type. For
609 -- completeness, analyze prefix as well.
611 if Present (Entity (N)) then
612 if Is_Type (Entity (N)) then
613 Set_Etype (N, Entity (N));
615 Set_Etype (N, Etype (Entity (N)));
618 Analyze (Prefix (N));
621 Find_Expanded_Name (N);
624 Analyze_Dimension (N);
625 end Analyze_Expanded_Name;
627 ---------------------------------------
628 -- Analyze_Generic_Function_Renaming --
629 ---------------------------------------
631 procedure Analyze_Generic_Function_Renaming (N : Node_Id) is
633 Analyze_Generic_Renaming (N, E_Generic_Function);
634 end Analyze_Generic_Function_Renaming;
636 --------------------------------------
637 -- Analyze_Generic_Package_Renaming --
638 --------------------------------------
640 procedure Analyze_Generic_Package_Renaming (N : Node_Id) is
642 -- Test for the Text_IO special unit case here, since we may be renaming
643 -- one of the subpackages of Text_IO, then join common routine.
645 Check_Text_IO_Special_Unit (Name (N));
647 Analyze_Generic_Renaming (N, E_Generic_Package);
648 end Analyze_Generic_Package_Renaming;
650 ----------------------------------------
651 -- Analyze_Generic_Procedure_Renaming --
652 ----------------------------------------
654 procedure Analyze_Generic_Procedure_Renaming (N : Node_Id) is
656 Analyze_Generic_Renaming (N, E_Generic_Procedure);
657 end Analyze_Generic_Procedure_Renaming;
659 ------------------------------
660 -- Analyze_Generic_Renaming --
661 ------------------------------
663 procedure Analyze_Generic_Renaming
667 New_P : constant Entity_Id := Defining_Entity (N);
669 Inst : Boolean := False; -- prevent junk warning
672 if Name (N) = Error then
676 -- The generic renaming declaration may be subject to pragma Ghost with
677 -- policy Ignore. Set the mode now to ensure that any nodes generated
678 -- during analysis and expansion are properly flagged as ignored Ghost.
681 Check_SPARK_05_Restriction ("generic renaming is not allowed", N);
683 Generate_Definition (New_P);
685 if Current_Scope /= Standard_Standard then
686 Set_Is_Pure (New_P, Is_Pure (Current_Scope));
689 if Nkind (Name (N)) = N_Selected_Component then
690 Check_Generic_Child_Unit (Name (N), Inst);
695 if not Is_Entity_Name (Name (N)) then
696 Error_Msg_N ("expect entity name in renaming declaration", Name (N));
699 Old_P := Entity (Name (N));
703 Set_Ekind (New_P, K);
705 if Etype (Old_P) = Any_Type then
708 elsif Ekind (Old_P) /= K then
709 Error_Msg_N ("invalid generic unit name", Name (N));
712 if Present (Renamed_Object (Old_P)) then
713 Set_Renamed_Object (New_P, Renamed_Object (Old_P));
715 Set_Renamed_Object (New_P, Old_P);
718 Set_Is_Pure (New_P, Is_Pure (Old_P));
719 Set_Is_Preelaborated (New_P, Is_Preelaborated (Old_P));
721 Set_Etype (New_P, Etype (Old_P));
722 Set_Has_Completion (New_P);
724 -- An generic renaming is Ghost if the renamed entity is Ghost or the
725 -- construct appears within a Ghost scope.
727 if Is_Ghost_Entity (Old_P) or else Ghost_Mode > None then
728 Set_Is_Ghost_Entity (New_P);
731 if In_Open_Scopes (Old_P) then
732 Error_Msg_N ("within its scope, generic denotes its instance", N);
735 -- For subprograms, propagate the Intrinsic flag, to allow, e.g.
736 -- renamings and subsequent instantiations of Unchecked_Conversion.
738 if Ekind_In (Old_P, E_Generic_Function, E_Generic_Procedure) then
739 Set_Is_Intrinsic_Subprogram
740 (New_P, Is_Intrinsic_Subprogram (Old_P));
743 Check_Library_Unit_Renaming (N, Old_P);
746 -- Implementation-defined aspect specifications can appear in a renaming
747 -- declaration, but not language-defined ones. The call to procedure
748 -- Analyze_Aspect_Specifications will take care of this error check.
750 if Has_Aspects (N) then
751 Analyze_Aspect_Specifications (N, New_P);
753 end Analyze_Generic_Renaming;
755 -----------------------------
756 -- Analyze_Object_Renaming --
757 -----------------------------
759 procedure Analyze_Object_Renaming (N : Node_Id) is
760 Loc : constant Source_Ptr := Sloc (N);
761 Id : constant Entity_Id := Defining_Identifier (N);
763 Nam : constant Node_Id := Name (N);
767 procedure Check_Constrained_Object;
768 -- If the nominal type is unconstrained but the renamed object is
769 -- constrained, as can happen with renaming an explicit dereference or
770 -- a function return, build a constrained subtype from the object. If
771 -- the renaming is for a formal in an accept statement, the analysis
772 -- has already established its actual subtype. This is only relevant
773 -- if the renamed object is an explicit dereference.
775 function In_Generic_Scope (E : Entity_Id) return Boolean;
776 -- Determine whether entity E is inside a generic cope
778 ------------------------------
779 -- Check_Constrained_Object --
780 ------------------------------
782 procedure Check_Constrained_Object is
783 Typ : constant Entity_Id := Etype (Nam);
787 if Nkind_In (Nam, N_Function_Call, N_Explicit_Dereference)
788 and then Is_Composite_Type (Etype (Nam))
789 and then not Is_Constrained (Etype (Nam))
790 and then not Has_Unknown_Discriminants (Etype (Nam))
791 and then Expander_Active
793 -- If Actual_Subtype is already set, nothing to do
795 if Ekind_In (Id, E_Variable, E_Constant)
796 and then Present (Actual_Subtype (Id))
800 -- A renaming of an unchecked union has no actual subtype
802 elsif Is_Unchecked_Union (Typ) then
805 -- If a record is limited its size is invariant. This is the case
806 -- in particular with record types with an access discirminant
807 -- that are used in iterators. This is an optimization, but it
808 -- also prevents typing anomalies when the prefix is further
809 -- expanded. Limited types with discriminants are included.
811 elsif Is_Limited_Record (Typ)
813 (Ekind (Typ) = E_Limited_Private_Type
814 and then Has_Discriminants (Typ)
815 and then Is_Access_Type (Etype (First_Discriminant (Typ))))
820 Subt := Make_Temporary (Loc, 'T');
821 Remove_Side_Effects (Nam);
823 Make_Subtype_Declaration (Loc,
824 Defining_Identifier => Subt,
825 Subtype_Indication =>
826 Make_Subtype_From_Expr (Nam, Typ)));
827 Rewrite (Subtype_Mark (N), New_Occurrence_Of (Subt, Loc));
828 Set_Etype (Nam, Subt);
830 -- Freeze subtype at once, to prevent order of elaboration
831 -- issues in the backend. The renamed object exists, so its
832 -- type is already frozen in any case.
834 Freeze_Before (N, Subt);
837 end Check_Constrained_Object;
839 ----------------------
840 -- In_Generic_Scope --
841 ----------------------
843 function In_Generic_Scope (E : Entity_Id) return Boolean is
848 while Present (S) and then S /= Standard_Standard loop
849 if Is_Generic_Unit (S) then
857 end In_Generic_Scope;
859 -- Start of processing for Analyze_Object_Renaming
866 -- The object renaming declaration may be subject to pragma Ghost with
867 -- policy Ignore. Set the mode now to ensure that any nodes generated
868 -- during analysis and expansion are properly flagged as ignored Ghost.
871 Check_SPARK_05_Restriction ("object renaming is not allowed", N);
873 Set_Is_Pure (Id, Is_Pure (Current_Scope));
876 -- The renaming of a component that depends on a discriminant requires
877 -- an actual subtype, because in subsequent use of the object Gigi will
878 -- be unable to locate the actual bounds. This explicit step is required
879 -- when the renaming is generated in removing side effects of an
880 -- already-analyzed expression.
882 if Nkind (Nam) = N_Selected_Component and then Analyzed (Nam) then
884 Dec := Build_Actual_Subtype_Of_Component (Etype (Nam), Nam);
886 if Present (Dec) then
887 Insert_Action (N, Dec);
888 T := Defining_Identifier (Dec);
892 -- Complete analysis of the subtype mark in any case, for ASIS use
894 if Present (Subtype_Mark (N)) then
895 Find_Type (Subtype_Mark (N));
898 elsif Present (Subtype_Mark (N)) then
899 Find_Type (Subtype_Mark (N));
900 T := Entity (Subtype_Mark (N));
903 -- Reject renamings of conversions unless the type is tagged, or
904 -- the conversion is implicit (which can occur for cases of anonymous
905 -- access types in Ada 2012).
907 if Nkind (Nam) = N_Type_Conversion
908 and then Comes_From_Source (Nam)
909 and then not Is_Tagged_Type (T)
912 ("renaming of conversion only allowed for tagged types", Nam);
917 -- If the renamed object is a function call of a limited type,
918 -- the expansion of the renaming is complicated by the presence
919 -- of various temporaries and subtypes that capture constraints
920 -- of the renamed object. Rewrite node as an object declaration,
921 -- whose expansion is simpler. Given that the object is limited
922 -- there is no copy involved and no performance hit.
924 if Nkind (Nam) = N_Function_Call
925 and then Is_Limited_View (Etype (Nam))
926 and then not Is_Constrained (Etype (Nam))
927 and then Comes_From_Source (N)
930 Set_Ekind (Id, E_Constant);
932 Make_Object_Declaration (Loc,
933 Defining_Identifier => Id,
934 Constant_Present => True,
935 Object_Definition => New_Occurrence_Of (Etype (Nam), Loc),
936 Expression => Relocate_Node (Nam)));
940 -- Ada 2012 (AI05-149): Reject renaming of an anonymous access object
941 -- when renaming declaration has a named access type. The Ada 2012
942 -- coverage rules allow an anonymous access type in the context of
943 -- an expected named general access type, but the renaming rules
944 -- require the types to be the same. (An exception is when the type
945 -- of the renaming is also an anonymous access type, which can only
946 -- happen due to a renaming created by the expander.)
948 if Nkind (Nam) = N_Type_Conversion
949 and then not Comes_From_Source (Nam)
950 and then Ekind (Etype (Expression (Nam))) = E_Anonymous_Access_Type
951 and then Ekind (T) /= E_Anonymous_Access_Type
953 Wrong_Type (Expression (Nam), T); -- Should we give better error???
956 -- Check that a class-wide object is not being renamed as an object
957 -- of a specific type. The test for access types is needed to exclude
958 -- cases where the renamed object is a dynamically tagged access
959 -- result, such as occurs in certain expansions.
961 if Is_Tagged_Type (T) then
962 Check_Dynamically_Tagged_Expression
968 -- Ada 2005 (AI-230/AI-254): Access renaming
970 else pragma Assert (Present (Access_Definition (N)));
971 T := Access_Definition
973 N => Access_Definition (N));
977 -- Ada 2005 AI05-105: if the declaration has an anonymous access
978 -- type, the renamed object must also have an anonymous type, and
979 -- this is a name resolution rule. This was implicit in the last part
980 -- of the first sentence in 8.5.1(3/2), and is made explicit by this
983 if not Is_Overloaded (Nam) then
984 if Ekind (Etype (Nam)) /= Ekind (T) then
986 ("expect anonymous access type in object renaming", N);
993 Typ : Entity_Id := Empty;
994 Seen : Boolean := False;
997 Get_First_Interp (Nam, I, It);
998 while Present (It.Typ) loop
1000 -- Renaming is ambiguous if more than one candidate
1001 -- interpretation is type-conformant with the context.
1003 if Ekind (It.Typ) = Ekind (T) then
1004 if Ekind (T) = E_Anonymous_Access_Subprogram_Type
1007 (Designated_Type (T), Designated_Type (It.Typ))
1013 ("ambiguous expression in renaming", Nam);
1016 elsif Ekind (T) = E_Anonymous_Access_Type
1018 Covers (Designated_Type (T), Designated_Type (It.Typ))
1024 ("ambiguous expression in renaming", Nam);
1028 if Covers (T, It.Typ) then
1030 Set_Etype (Nam, Typ);
1031 Set_Is_Overloaded (Nam, False);
1035 Get_Next_Interp (I, It);
1042 -- Ada 2005 (AI-231): In the case where the type is defined by an
1043 -- access_definition, the renamed entity shall be of an access-to-
1044 -- constant type if and only if the access_definition defines an
1045 -- access-to-constant type. ARM 8.5.1(4)
1047 if Constant_Present (Access_Definition (N))
1048 and then not Is_Access_Constant (Etype (Nam))
1050 Error_Msg_N ("(Ada 2005): the renamed object is not "
1051 & "access-to-constant (RM 8.5.1(6))", N);
1053 elsif not Constant_Present (Access_Definition (N))
1054 and then Is_Access_Constant (Etype (Nam))
1056 Error_Msg_N ("(Ada 2005): the renamed object is not "
1057 & "access-to-variable (RM 8.5.1(6))", N);
1060 if Is_Access_Subprogram_Type (Etype (Nam)) then
1061 Check_Subtype_Conformant
1062 (Designated_Type (T), Designated_Type (Etype (Nam)));
1064 elsif not Subtypes_Statically_Match
1065 (Designated_Type (T),
1066 Available_View (Designated_Type (Etype (Nam))))
1069 ("subtype of renamed object does not statically match", N);
1073 -- Special processing for renaming function return object. Some errors
1074 -- and warnings are produced only for calls that come from source.
1076 if Nkind (Nam) = N_Function_Call then
1079 -- Usage is illegal in Ada 83, but renamings are also introduced
1080 -- during expansion, and error does not apply to those.
1083 if Comes_From_Source (N) then
1085 ("(Ada 83) cannot rename function return object", Nam);
1088 -- In Ada 95, warn for odd case of renaming parameterless function
1089 -- call if this is not a limited type (where this is useful).
1092 if Warn_On_Object_Renames_Function
1093 and then No (Parameter_Associations (Nam))
1094 and then not Is_Limited_Type (Etype (Nam))
1095 and then Comes_From_Source (Nam)
1098 ("renaming function result object is suspicious?R?", Nam);
1100 ("\function & will be called only once?R?", Nam,
1101 Entity (Name (Nam)));
1102 Error_Msg_N -- CODEFIX
1103 ("\suggest using an initialized constant "
1104 & "object instead?R?", Nam);
1110 Check_Constrained_Object;
1112 -- An object renaming requires an exact match of the type. Class-wide
1113 -- matching is not allowed.
1115 if Is_Class_Wide_Type (T)
1116 and then Base_Type (Etype (Nam)) /= Base_Type (T)
1118 Wrong_Type (Nam, T);
1123 -- Ada 2005 (AI-326): Handle wrong use of incomplete type
1125 if Nkind (Nam) = N_Explicit_Dereference
1126 and then Ekind (Etype (T2)) = E_Incomplete_Type
1128 Error_Msg_NE ("invalid use of incomplete type&", Id, T2);
1131 elsif Ekind (Etype (T)) = E_Incomplete_Type then
1132 Error_Msg_NE ("invalid use of incomplete type&", Id, T);
1136 -- Ada 2005 (AI-327)
1138 if Ada_Version >= Ada_2005
1139 and then Nkind (Nam) = N_Attribute_Reference
1140 and then Attribute_Name (Nam) = Name_Priority
1144 elsif Ada_Version >= Ada_2005 and then Nkind (Nam) in N_Has_Entity then
1147 Nam_Ent : Entity_Id;
1150 if Nkind (Nam) = N_Attribute_Reference then
1151 Nam_Ent := Entity (Prefix (Nam));
1153 Nam_Ent := Entity (Nam);
1156 Nam_Decl := Parent (Nam_Ent);
1158 if Has_Null_Exclusion (N)
1159 and then not Has_Null_Exclusion (Nam_Decl)
1161 -- Ada 2005 (AI-423): If the object name denotes a generic
1162 -- formal object of a generic unit G, and the object renaming
1163 -- declaration occurs within the body of G or within the body
1164 -- of a generic unit declared within the declarative region
1165 -- of G, then the declaration of the formal object of G must
1166 -- have a null exclusion or a null-excluding subtype.
1168 if Is_Formal_Object (Nam_Ent)
1169 and then In_Generic_Scope (Id)
1171 if not Can_Never_Be_Null (Etype (Nam_Ent)) then
1173 ("renamed formal does not exclude `NULL` "
1174 & "(RM 8.5.1(4.6/2))", N);
1176 elsif In_Package_Body (Scope (Id)) then
1178 ("formal object does not have a null exclusion"
1179 & "(RM 8.5.1(4.6/2))", N);
1182 -- Ada 2005 (AI-423): Otherwise, the subtype of the object name
1183 -- shall exclude null.
1185 elsif not Can_Never_Be_Null (Etype (Nam_Ent)) then
1187 ("renamed object does not exclude `NULL` "
1188 & "(RM 8.5.1(4.6/2))", N);
1190 -- An instance is illegal if it contains a renaming that
1191 -- excludes null, and the actual does not. The renaming
1192 -- declaration has already indicated that the declaration
1193 -- of the renamed actual in the instance will raise
1194 -- constraint_error.
1196 elsif Nkind (Nam_Decl) = N_Object_Declaration
1197 and then In_Instance
1199 Present (Corresponding_Generic_Association (Nam_Decl))
1200 and then Nkind (Expression (Nam_Decl)) =
1201 N_Raise_Constraint_Error
1204 ("renamed actual does not exclude `NULL` "
1205 & "(RM 8.5.1(4.6/2))", N);
1207 -- Finally, if there is a null exclusion, the subtype mark
1208 -- must not be null-excluding.
1210 elsif No (Access_Definition (N))
1211 and then Can_Never_Be_Null (T)
1214 ("`NOT NULL` not allowed (& already excludes null)",
1219 elsif Can_Never_Be_Null (T)
1220 and then not Can_Never_Be_Null (Etype (Nam_Ent))
1223 ("renamed object does not exclude `NULL` "
1224 & "(RM 8.5.1(4.6/2))", N);
1226 elsif Has_Null_Exclusion (N)
1227 and then No (Access_Definition (N))
1228 and then Can_Never_Be_Null (T)
1231 ("`NOT NULL` not allowed (& already excludes null)", N, T);
1236 -- Set the Ekind of the entity, unless it has been set already, as is
1237 -- the case for the iteration object over a container with no variable
1238 -- indexing. In that case it's been marked as a constant, and we do not
1239 -- want to change it to a variable.
1241 if Ekind (Id) /= E_Constant then
1242 Set_Ekind (Id, E_Variable);
1245 -- Initialize the object size and alignment. Note that we used to call
1246 -- Init_Size_Align here, but that's wrong for objects which have only
1247 -- an Esize, not an RM_Size field.
1249 Init_Object_Size_Align (Id);
1251 if T = Any_Type or else Etype (Nam) = Any_Type then
1254 -- Verify that the renamed entity is an object or a function call. It
1255 -- may have been rewritten in several ways.
1257 elsif Is_Object_Reference (Nam) then
1258 if Comes_From_Source (N) then
1259 if Is_Dependent_Component_Of_Mutable_Object (Nam) then
1261 ("illegal renaming of discriminant-dependent component", Nam);
1264 -- If the renaming comes from source and the renamed object is a
1265 -- dereference, then mark the prefix as needing debug information,
1266 -- since it might have been rewritten hence internally generated
1267 -- and Debug_Renaming_Declaration will link the renaming to it.
1269 if Nkind (Nam) = N_Explicit_Dereference
1270 and then Is_Entity_Name (Prefix (Nam))
1272 Set_Debug_Info_Needed (Entity (Prefix (Nam)));
1276 -- A static function call may have been folded into a literal
1278 elsif Nkind (Original_Node (Nam)) = N_Function_Call
1280 -- When expansion is disabled, attribute reference is not rewritten
1281 -- as function call. Otherwise it may be rewritten as a conversion,
1282 -- so check original node.
1284 or else (Nkind (Original_Node (Nam)) = N_Attribute_Reference
1285 and then Is_Function_Attribute_Name
1286 (Attribute_Name (Original_Node (Nam))))
1288 -- Weird but legal, equivalent to renaming a function call. Illegal
1289 -- if the literal is the result of constant-folding an attribute
1290 -- reference that is not a function.
1292 or else (Is_Entity_Name (Nam)
1293 and then Ekind (Entity (Nam)) = E_Enumeration_Literal
1295 Nkind (Original_Node (Nam)) /= N_Attribute_Reference)
1297 or else (Nkind (Nam) = N_Type_Conversion
1298 and then Is_Tagged_Type (Entity (Subtype_Mark (Nam))))
1302 elsif Nkind (Nam) = N_Type_Conversion then
1304 ("renaming of conversion only allowed for tagged types", Nam);
1306 -- Ada 2005 (AI-327)
1308 elsif Ada_Version >= Ada_2005
1309 and then Nkind (Nam) = N_Attribute_Reference
1310 and then Attribute_Name (Nam) = Name_Priority
1314 -- Allow internally generated x'Reference expression
1316 elsif Nkind (Nam) = N_Reference then
1320 Error_Msg_N ("expect object name in renaming", Nam);
1325 if not Is_Variable (Nam) then
1326 Set_Ekind (Id, E_Constant);
1327 Set_Never_Set_In_Source (Id, True);
1328 Set_Is_True_Constant (Id, True);
1331 -- An object renaming is Ghost if the renamed entity is Ghost or the
1332 -- construct appears within a Ghost scope.
1334 if (Is_Entity_Name (Nam)
1335 and then Is_Ghost_Entity (Entity (Nam)))
1336 or else Ghost_Mode > None
1338 Set_Is_Ghost_Entity (Id);
1341 -- The entity of the renaming declaration needs to reflect whether the
1342 -- renamed object is volatile. Is_Volatile is set if the renamed object
1343 -- is volatile in the RM legality sense.
1345 Set_Is_Volatile (Id, Is_Volatile_Object (Nam));
1347 -- Also copy settings of Atomic/Independent/Volatile_Full_Access
1349 if Is_Entity_Name (Nam) then
1350 Set_Is_Atomic (Id, Is_Atomic (Entity (Nam)));
1351 Set_Is_Independent (Id, Is_Independent (Entity (Nam)));
1352 Set_Has_Volatile_Full_Access (Id,
1353 Has_Volatile_Full_Access (Entity (Nam)));
1356 -- Treat as volatile if we just set the Volatile flag
1360 -- Or if we are renaming an entity which was marked this way
1362 -- Are there more cases, e.g. X(J) where X is Treat_As_Volatile ???
1364 or else (Is_Entity_Name (Nam)
1365 and then Treat_As_Volatile (Entity (Nam)))
1367 Set_Treat_As_Volatile (Id, True);
1370 -- Now make the link to the renamed object
1372 Set_Renamed_Object (Id, Nam);
1374 -- Implementation-defined aspect specifications can appear in a renaming
1375 -- declaration, but not language-defined ones. The call to procedure
1376 -- Analyze_Aspect_Specifications will take care of this error check.
1378 if Has_Aspects (N) then
1379 Analyze_Aspect_Specifications (N, Id);
1382 -- Deal with dimensions
1384 Analyze_Dimension (N);
1385 end Analyze_Object_Renaming;
1387 ------------------------------
1388 -- Analyze_Package_Renaming --
1389 ------------------------------
1391 procedure Analyze_Package_Renaming (N : Node_Id) is
1392 New_P : constant Entity_Id := Defining_Entity (N);
1397 if Name (N) = Error then
1401 -- The package renaming declaration may be subject to pragma Ghost with
1402 -- policy Ignore. Set the mode now to ensure that any nodes generated
1403 -- during analysis and expansion are properly flagged as ignored Ghost.
1407 -- Check for Text_IO special unit (we may be renaming a Text_IO child)
1409 Check_Text_IO_Special_Unit (Name (N));
1411 if Current_Scope /= Standard_Standard then
1412 Set_Is_Pure (New_P, Is_Pure (Current_Scope));
1418 if Is_Entity_Name (Name (N)) then
1419 Old_P := Entity (Name (N));
1424 if Etype (Old_P) = Any_Type then
1425 Error_Msg_N ("expect package name in renaming", Name (N));
1427 elsif Ekind (Old_P) /= E_Package
1428 and then not (Ekind (Old_P) = E_Generic_Package
1429 and then In_Open_Scopes (Old_P))
1431 if Ekind (Old_P) = E_Generic_Package then
1433 ("generic package cannot be renamed as a package", Name (N));
1435 Error_Msg_Sloc := Sloc (Old_P);
1437 ("expect package name in renaming, found& declared#",
1441 -- Set basic attributes to minimize cascaded errors
1443 Set_Ekind (New_P, E_Package);
1444 Set_Etype (New_P, Standard_Void_Type);
1446 -- Here for OK package renaming
1449 -- Entities in the old package are accessible through the renaming
1450 -- entity. The simplest implementation is to have both packages share
1453 Set_Ekind (New_P, E_Package);
1454 Set_Etype (New_P, Standard_Void_Type);
1456 if Present (Renamed_Object (Old_P)) then
1457 Set_Renamed_Object (New_P, Renamed_Object (Old_P));
1459 Set_Renamed_Object (New_P, Old_P);
1462 Set_Has_Completion (New_P);
1464 Set_First_Entity (New_P, First_Entity (Old_P));
1465 Set_Last_Entity (New_P, Last_Entity (Old_P));
1466 Set_First_Private_Entity (New_P, First_Private_Entity (Old_P));
1467 Check_Library_Unit_Renaming (N, Old_P);
1468 Generate_Reference (Old_P, Name (N));
1470 -- A package renaming is Ghost if the renamed entity is Ghost or
1471 -- the construct appears within a Ghost scope.
1473 if Is_Ghost_Entity (Old_P) or else Ghost_Mode > None then
1474 Set_Is_Ghost_Entity (New_P);
1477 -- If the renaming is in the visible part of a package, then we set
1478 -- Renamed_In_Spec for the renamed package, to prevent giving
1479 -- warnings about no entities referenced. Such a warning would be
1480 -- overenthusiastic, since clients can see entities in the renamed
1481 -- package via the visible package renaming.
1484 Ent : constant Entity_Id := Cunit_Entity (Current_Sem_Unit);
1486 if Ekind (Ent) = E_Package
1487 and then not In_Private_Part (Ent)
1488 and then In_Extended_Main_Source_Unit (N)
1489 and then Ekind (Old_P) = E_Package
1491 Set_Renamed_In_Spec (Old_P);
1495 -- If this is the renaming declaration of a package instantiation
1496 -- within itself, it is the declaration that ends the list of actuals
1497 -- for the instantiation. At this point, the subtypes that rename
1498 -- the actuals are flagged as generic, to avoid spurious ambiguities
1499 -- if the actuals for two distinct formals happen to coincide. If
1500 -- the actual is a private type, the subtype has a private completion
1501 -- that is flagged in the same fashion.
1503 -- Resolution is identical to what is was in the original generic.
1504 -- On exit from the generic instance, these are turned into regular
1505 -- subtypes again, so they are compatible with types in their class.
1507 if not Is_Generic_Instance (Old_P) then
1510 Spec := Specification (Unit_Declaration_Node (Old_P));
1513 if Nkind (Spec) = N_Package_Specification
1514 and then Present (Generic_Parent (Spec))
1515 and then Old_P = Current_Scope
1516 and then Chars (New_P) = Chars (Generic_Parent (Spec))
1522 E := First_Entity (Old_P);
1523 while Present (E) and then E /= New_P loop
1525 and then Nkind (Parent (E)) = N_Subtype_Declaration
1527 Set_Is_Generic_Actual_Type (E);
1529 if Is_Private_Type (E)
1530 and then Present (Full_View (E))
1532 Set_Is_Generic_Actual_Type (Full_View (E));
1542 -- Implementation-defined aspect specifications can appear in a renaming
1543 -- declaration, but not language-defined ones. The call to procedure
1544 -- Analyze_Aspect_Specifications will take care of this error check.
1546 if Has_Aspects (N) then
1547 Analyze_Aspect_Specifications (N, New_P);
1549 end Analyze_Package_Renaming;
1551 -------------------------------
1552 -- Analyze_Renamed_Character --
1553 -------------------------------
1555 procedure Analyze_Renamed_Character
1560 C : constant Node_Id := Name (N);
1563 if Ekind (New_S) = E_Function then
1564 Resolve (C, Etype (New_S));
1567 Check_Frozen_Renaming (N, New_S);
1571 Error_Msg_N ("character literal can only be renamed as function", N);
1573 end Analyze_Renamed_Character;
1575 ---------------------------------
1576 -- Analyze_Renamed_Dereference --
1577 ---------------------------------
1579 procedure Analyze_Renamed_Dereference
1584 Nam : constant Node_Id := Name (N);
1585 P : constant Node_Id := Prefix (Nam);
1591 if not Is_Overloaded (P) then
1592 if Ekind (Etype (Nam)) /= E_Subprogram_Type
1593 or else not Type_Conformant (Etype (Nam), New_S)
1595 Error_Msg_N ("designated type does not match specification", P);
1604 Get_First_Interp (Nam, Ind, It);
1606 while Present (It.Nam) loop
1608 if Ekind (It.Nam) = E_Subprogram_Type
1609 and then Type_Conformant (It.Nam, New_S)
1611 if Typ /= Any_Id then
1612 Error_Msg_N ("ambiguous renaming", P);
1619 Get_Next_Interp (Ind, It);
1622 if Typ = Any_Type then
1623 Error_Msg_N ("designated type does not match specification", P);
1628 Check_Frozen_Renaming (N, New_S);
1632 end Analyze_Renamed_Dereference;
1634 ---------------------------
1635 -- Analyze_Renamed_Entry --
1636 ---------------------------
1638 procedure Analyze_Renamed_Entry
1643 Nam : constant Node_Id := Name (N);
1644 Sel : constant Node_Id := Selector_Name (Nam);
1645 Is_Actual : constant Boolean := Present (Corresponding_Formal_Spec (N));
1649 if Entity (Sel) = Any_Id then
1651 -- Selector is undefined on prefix. Error emitted already
1653 Set_Has_Completion (New_S);
1657 -- Otherwise find renamed entity and build body of New_S as a call to it
1659 Old_S := Find_Renamed_Entity (N, Selector_Name (Nam), New_S);
1661 if Old_S = Any_Id then
1662 Error_Msg_N (" no subprogram or entry matches specification", N);
1665 Check_Subtype_Conformant (New_S, Old_S, N);
1666 Generate_Reference (New_S, Defining_Entity (N), 'b');
1667 Style.Check_Identifier (Defining_Entity (N), New_S);
1670 -- Only mode conformance required for a renaming_as_declaration
1672 Check_Mode_Conformant (New_S, Old_S, N);
1675 Inherit_Renamed_Profile (New_S, Old_S);
1677 -- The prefix can be an arbitrary expression that yields a task or
1678 -- protected object, so it must be resolved.
1680 Resolve (Prefix (Nam), Scope (Old_S));
1683 Set_Convention (New_S, Convention (Old_S));
1684 Set_Has_Completion (New_S, Inside_A_Generic);
1686 -- AI05-0225: If the renamed entity is a procedure or entry of a
1687 -- protected object, the target object must be a variable.
1689 if Ekind (Scope (Old_S)) in Protected_Kind
1690 and then Ekind (New_S) = E_Procedure
1691 and then not Is_Variable (Prefix (Nam))
1695 ("target object of protected operation used as actual for "
1696 & "formal procedure must be a variable", Nam);
1699 ("target object of protected operation renamed as procedure, "
1700 & "must be a variable", Nam);
1705 Check_Frozen_Renaming (N, New_S);
1707 end Analyze_Renamed_Entry;
1709 -----------------------------------
1710 -- Analyze_Renamed_Family_Member --
1711 -----------------------------------
1713 procedure Analyze_Renamed_Family_Member
1718 Nam : constant Node_Id := Name (N);
1719 P : constant Node_Id := Prefix (Nam);
1723 if (Is_Entity_Name (P) and then Ekind (Entity (P)) = E_Entry_Family)
1724 or else (Nkind (P) = N_Selected_Component
1725 and then Ekind (Entity (Selector_Name (P))) = E_Entry_Family)
1727 if Is_Entity_Name (P) then
1728 Old_S := Entity (P);
1730 Old_S := Entity (Selector_Name (P));
1733 if not Entity_Matches_Spec (Old_S, New_S) then
1734 Error_Msg_N ("entry family does not match specification", N);
1737 Check_Subtype_Conformant (New_S, Old_S, N);
1738 Generate_Reference (New_S, Defining_Entity (N), 'b');
1739 Style.Check_Identifier (Defining_Entity (N), New_S);
1743 Error_Msg_N ("no entry family matches specification", N);
1746 Set_Has_Completion (New_S, Inside_A_Generic);
1749 Check_Frozen_Renaming (N, New_S);
1751 end Analyze_Renamed_Family_Member;
1753 -----------------------------------------
1754 -- Analyze_Renamed_Primitive_Operation --
1755 -----------------------------------------
1757 procedure Analyze_Renamed_Primitive_Operation
1766 Ctyp : Conformance_Type) return Boolean;
1767 -- Verify that the signatures of the renamed entity and the new entity
1768 -- match. The first formal of the renamed entity is skipped because it
1769 -- is the target object in any subsequent call.
1777 Ctyp : Conformance_Type) return Boolean
1783 if Ekind (Subp) /= Ekind (New_S) then
1787 Old_F := Next_Formal (First_Formal (Subp));
1788 New_F := First_Formal (New_S);
1789 while Present (Old_F) and then Present (New_F) loop
1790 if not Conforming_Types (Etype (Old_F), Etype (New_F), Ctyp) then
1794 if Ctyp >= Mode_Conformant
1795 and then Ekind (Old_F) /= Ekind (New_F)
1800 Next_Formal (New_F);
1801 Next_Formal (Old_F);
1807 -- Start of processing for Analyze_Renamed_Primitive_Operation
1810 if not Is_Overloaded (Selector_Name (Name (N))) then
1811 Old_S := Entity (Selector_Name (Name (N)));
1813 if not Conforms (Old_S, Type_Conformant) then
1818 -- Find the operation that matches the given signature
1826 Get_First_Interp (Selector_Name (Name (N)), Ind, It);
1828 while Present (It.Nam) loop
1829 if Conforms (It.Nam, Type_Conformant) then
1833 Get_Next_Interp (Ind, It);
1838 if Old_S = Any_Id then
1839 Error_Msg_N (" no subprogram or entry matches specification", N);
1843 if not Conforms (Old_S, Subtype_Conformant) then
1844 Error_Msg_N ("subtype conformance error in renaming", N);
1847 Generate_Reference (New_S, Defining_Entity (N), 'b');
1848 Style.Check_Identifier (Defining_Entity (N), New_S);
1851 -- Only mode conformance required for a renaming_as_declaration
1853 if not Conforms (Old_S, Mode_Conformant) then
1854 Error_Msg_N ("mode conformance error in renaming", N);
1857 -- Enforce the rule given in (RM 6.3.1 (10.1/2)): a prefixed
1858 -- view of a subprogram is intrinsic, because the compiler has
1859 -- to generate a wrapper for any call to it. If the name in a
1860 -- subprogram renaming is a prefixed view, the entity is thus
1861 -- intrinsic, and 'Access cannot be applied to it.
1863 Set_Convention (New_S, Convention_Intrinsic);
1866 -- Inherit_Renamed_Profile (New_S, Old_S);
1868 -- The prefix can be an arbitrary expression that yields an
1869 -- object, so it must be resolved.
1871 Resolve (Prefix (Name (N)));
1873 end Analyze_Renamed_Primitive_Operation;
1875 ---------------------------------
1876 -- Analyze_Subprogram_Renaming --
1877 ---------------------------------
1879 procedure Analyze_Subprogram_Renaming (N : Node_Id) is
1880 Formal_Spec : constant Entity_Id := Corresponding_Formal_Spec (N);
1881 Is_Actual : constant Boolean := Present (Formal_Spec);
1882 Nam : constant Node_Id := Name (N);
1883 Save_AV : constant Ada_Version_Type := Ada_Version;
1884 Save_AVP : constant Node_Id := Ada_Version_Pragma;
1885 Save_AV_Exp : constant Ada_Version_Type := Ada_Version_Explicit;
1886 Spec : constant Node_Id := Specification (N);
1888 Old_S : Entity_Id := Empty;
1889 Rename_Spec : Entity_Id;
1891 procedure Build_Class_Wide_Wrapper
1892 (Ren_Id : out Entity_Id;
1893 Wrap_Id : out Entity_Id);
1894 -- Ada 2012 (AI05-0071): A generic/instance scenario involving a formal
1895 -- type with unknown discriminants and a generic primitive operation of
1896 -- the said type with a box require special processing when the actual
1897 -- is a class-wide type:
1900 -- type Formal_Typ (<>) is private;
1901 -- with procedure Prim_Op (Param : Formal_Typ) is <>;
1902 -- package Gen is ...
1904 -- package Inst is new Gen (Actual_Typ'Class);
1906 -- In this case the general renaming mechanism used in the prologue of
1907 -- an instance no longer applies:
1909 -- procedure Prim_Op (Param : Formal_Typ) renames Prim_Op;
1911 -- The above is replaced the following wrapper/renaming combination:
1913 -- procedure Wrapper (Param : Formal_Typ) is -- wrapper
1915 -- Prim_Op (Param); -- primitive
1918 -- procedure Prim_Op (Param : Formal_Typ) renames Wrapper;
1920 -- This transformation applies only if there is no explicit visible
1921 -- class-wide operation at the point of the instantiation. Ren_Id is
1922 -- the entity of the renaming declaration. Wrap_Id is the entity of
1923 -- the generated class-wide wrapper (or Any_Id).
1925 procedure Check_Null_Exclusion
1928 -- Ada 2005 (AI-423): Given renaming Ren of subprogram Sub, check the
1929 -- following AI rules:
1931 -- If Ren is a renaming of a formal subprogram and one of its
1932 -- parameters has a null exclusion, then the corresponding formal
1933 -- in Sub must also have one. Otherwise the subtype of the Sub's
1934 -- formal parameter must exclude null.
1936 -- If Ren is a renaming of a formal function and its return
1937 -- profile has a null exclusion, then Sub's return profile must
1938 -- have one. Otherwise the subtype of Sub's return profile must
1941 procedure Freeze_Actual_Profile;
1942 -- In Ada 2012, enforce the freezing rule concerning formal incomplete
1943 -- types: a callable entity freezes its profile, unless it has an
1944 -- incomplete untagged formal (RM 13.14(10.2/3)).
1946 function Has_Class_Wide_Actual return Boolean;
1947 -- Ada 2012 (AI05-071, AI05-0131): True if N is the renaming for a
1948 -- defaulted formal subprogram where the actual for the controlling
1949 -- formal type is class-wide.
1951 function Original_Subprogram (Subp : Entity_Id) return Entity_Id;
1952 -- Find renamed entity when the declaration is a renaming_as_body and
1953 -- the renamed entity may itself be a renaming_as_body. Used to enforce
1954 -- rule that a renaming_as_body is illegal if the declaration occurs
1955 -- before the subprogram it completes is frozen, and renaming indirectly
1956 -- renames the subprogram itself.(Defect Report 8652/0027).
1958 ------------------------------
1959 -- Build_Class_Wide_Wrapper --
1960 ------------------------------
1962 procedure Build_Class_Wide_Wrapper
1963 (Ren_Id : out Entity_Id;
1964 Wrap_Id : out Entity_Id)
1966 Loc : constant Source_Ptr := Sloc (N);
1969 (Subp_Id : Entity_Id;
1970 Params : List_Id) return Node_Id;
1971 -- Create a dispatching call to invoke routine Subp_Id with actuals
1972 -- built from the parameter specifications of list Params.
1974 function Build_Spec (Subp_Id : Entity_Id) return Node_Id;
1975 -- Create a subprogram specification based on the subprogram profile
1978 function Find_Primitive (Typ : Entity_Id) return Entity_Id;
1979 -- Find a primitive subprogram of type Typ which matches the profile
1980 -- of the renaming declaration.
1982 procedure Interpretation_Error (Subp_Id : Entity_Id);
1983 -- Emit a continuation error message suggesting subprogram Subp_Id as
1984 -- a possible interpretation.
1986 function Is_Intrinsic_Equality (Subp_Id : Entity_Id) return Boolean;
1987 -- Determine whether subprogram Subp_Id denotes the intrinsic "="
1990 function Is_Suitable_Candidate (Subp_Id : Entity_Id) return Boolean;
1991 -- Determine whether subprogram Subp_Id is a suitable candidate for
1992 -- the role of a wrapped subprogram.
1999 (Subp_Id : Entity_Id;
2000 Params : List_Id) return Node_Id
2002 Actuals : constant List_Id := New_List;
2003 Call_Ref : constant Node_Id := New_Occurrence_Of (Subp_Id, Loc);
2007 -- Build the actual parameters of the call
2009 Formal := First (Params);
2010 while Present (Formal) loop
2012 Make_Identifier (Loc, Chars (Defining_Identifier (Formal))));
2017 -- return Subp_Id (Actuals);
2019 if Ekind_In (Subp_Id, E_Function, E_Operator) then
2021 Make_Simple_Return_Statement (Loc,
2023 Make_Function_Call (Loc,
2025 Parameter_Associations => Actuals));
2028 -- Subp_Id (Actuals);
2032 Make_Procedure_Call_Statement (Loc,
2034 Parameter_Associations => Actuals);
2042 function Build_Spec (Subp_Id : Entity_Id) return Node_Id is
2043 Params : constant List_Id := Copy_Parameter_List (Subp_Id);
2044 Spec_Id : constant Entity_Id :=
2045 Make_Defining_Identifier (Loc,
2046 Chars => New_External_Name (Chars (Subp_Id), 'R'));
2049 if Ekind (Formal_Spec) = E_Procedure then
2051 Make_Procedure_Specification (Loc,
2052 Defining_Unit_Name => Spec_Id,
2053 Parameter_Specifications => Params);
2056 Make_Function_Specification (Loc,
2057 Defining_Unit_Name => Spec_Id,
2058 Parameter_Specifications => Params,
2059 Result_Definition =>
2060 New_Copy_Tree (Result_Definition (Spec)));
2064 --------------------
2065 -- Find_Primitive --
2066 --------------------
2068 function Find_Primitive (Typ : Entity_Id) return Entity_Id is
2069 procedure Replace_Parameter_Types (Spec : Node_Id);
2070 -- Given a specification Spec, replace all class-wide parameter
2071 -- types with reference to type Typ.
2073 -----------------------------
2074 -- Replace_Parameter_Types --
2075 -----------------------------
2077 procedure Replace_Parameter_Types (Spec : Node_Id) is
2079 Formal_Id : Entity_Id;
2080 Formal_Typ : Node_Id;
2083 Formal := First (Parameter_Specifications (Spec));
2084 while Present (Formal) loop
2085 Formal_Id := Defining_Identifier (Formal);
2086 Formal_Typ := Parameter_Type (Formal);
2088 -- Create a new entity for each class-wide formal to prevent
2089 -- aliasing with the original renaming. Replace the type of
2090 -- such a parameter with the candidate type.
2092 if Nkind (Formal_Typ) = N_Identifier
2093 and then Is_Class_Wide_Type (Etype (Formal_Typ))
2095 Set_Defining_Identifier (Formal,
2096 Make_Defining_Identifier (Loc, Chars (Formal_Id)));
2098 Set_Parameter_Type (Formal, New_Occurrence_Of (Typ, Loc));
2103 end Replace_Parameter_Types;
2107 Alt_Ren : constant Node_Id := New_Copy_Tree (N);
2108 Alt_Nam : constant Node_Id := Name (Alt_Ren);
2109 Alt_Spec : constant Node_Id := Specification (Alt_Ren);
2110 Subp_Id : Entity_Id;
2112 -- Start of processing for Find_Primitive
2115 -- Each attempt to find a suitable primitive of a particular type
2116 -- operates on its own copy of the original renaming. As a result
2117 -- the original renaming is kept decoration and side-effect free.
2119 -- Inherit the overloaded status of the renamed subprogram name
2121 if Is_Overloaded (Nam) then
2122 Set_Is_Overloaded (Alt_Nam);
2123 Save_Interps (Nam, Alt_Nam);
2126 -- The copied renaming is hidden from visibility to prevent the
2127 -- pollution of the enclosing context.
2129 Set_Defining_Unit_Name (Alt_Spec, Make_Temporary (Loc, 'R'));
2131 -- The types of all class-wide parameters must be changed to the
2134 Replace_Parameter_Types (Alt_Spec);
2136 -- Try to find a suitable primitive which matches the altered
2137 -- profile of the renaming specification.
2142 Nam => Name (Alt_Ren),
2143 New_S => Analyze_Subprogram_Specification (Alt_Spec),
2144 Is_Actual => Is_Actual);
2146 -- Do not return Any_Id if the resolion of the altered profile
2147 -- failed as this complicates further checks on the caller side,
2148 -- return Empty instead.
2150 if Subp_Id = Any_Id then
2157 --------------------------
2158 -- Interpretation_Error --
2159 --------------------------
2161 procedure Interpretation_Error (Subp_Id : Entity_Id) is
2163 Error_Msg_Sloc := Sloc (Subp_Id);
2165 if Is_Internal (Subp_Id) then
2167 ("\\possible interpretation: predefined & #",
2171 ("\\possible interpretation: & defined #", Spec, Formal_Spec);
2173 end Interpretation_Error;
2175 ---------------------------
2176 -- Is_Intrinsic_Equality --
2177 ---------------------------
2179 function Is_Intrinsic_Equality (Subp_Id : Entity_Id) return Boolean is
2182 Ekind (Subp_Id) = E_Operator
2183 and then Chars (Subp_Id) = Name_Op_Eq
2184 and then Is_Intrinsic_Subprogram (Subp_Id);
2185 end Is_Intrinsic_Equality;
2187 ---------------------------
2188 -- Is_Suitable_Candidate --
2189 ---------------------------
2191 function Is_Suitable_Candidate (Subp_Id : Entity_Id) return Boolean is
2193 if No (Subp_Id) then
2196 -- An intrinsic subprogram is never a good candidate. This is an
2197 -- indication of a missing primitive, either defined directly or
2198 -- inherited from a parent tagged type.
2200 elsif Is_Intrinsic_Subprogram (Subp_Id) then
2206 end Is_Suitable_Candidate;
2210 Actual_Typ : Entity_Id := Empty;
2211 -- The actual class-wide type for Formal_Typ
2213 CW_Prim_OK : Boolean;
2214 CW_Prim_Op : Entity_Id;
2215 -- The class-wide subprogram (if available) which corresponds to the
2216 -- renamed generic formal subprogram.
2218 Formal_Typ : Entity_Id := Empty;
2219 -- The generic formal type with unknown discriminants
2221 Root_Prim_OK : Boolean;
2222 Root_Prim_Op : Entity_Id;
2223 -- The root type primitive (if available) which corresponds to the
2224 -- renamed generic formal subprogram.
2226 Root_Typ : Entity_Id := Empty;
2227 -- The root type of Actual_Typ
2229 Body_Decl : Node_Id;
2231 Prim_Op : Entity_Id;
2232 Spec_Decl : Node_Id;
2234 -- Start of processing for Build_Class_Wide_Wrapper
2237 -- Analyze the specification of the renaming in case the generation
2238 -- of the class-wide wrapper fails.
2240 Ren_Id := Analyze_Subprogram_Specification (Spec);
2243 -- Do not attempt to build a wrapper if the renaming is in error
2245 if Error_Posted (Nam) then
2249 -- Analyze the renamed name, but do not resolve it. The resolution is
2250 -- completed once a suitable subprogram is found.
2254 -- When the renamed name denotes the intrinsic operator equals, the
2255 -- name must be treated as overloaded. This allows for a potential
2256 -- match against the root type's predefined equality function.
2258 if Is_Intrinsic_Equality (Entity (Nam)) then
2259 Set_Is_Overloaded (Nam);
2260 Collect_Interps (Nam);
2263 -- Step 1: Find the generic formal type with unknown discriminants
2264 -- and its corresponding class-wide actual type from the renamed
2265 -- generic formal subprogram.
2267 Formal := First_Formal (Formal_Spec);
2268 while Present (Formal) loop
2269 if Has_Unknown_Discriminants (Etype (Formal))
2270 and then not Is_Class_Wide_Type (Etype (Formal))
2271 and then Is_Class_Wide_Type (Get_Instance_Of (Etype (Formal)))
2273 Formal_Typ := Etype (Formal);
2274 Actual_Typ := Get_Instance_Of (Formal_Typ);
2275 Root_Typ := Etype (Actual_Typ);
2279 Next_Formal (Formal);
2282 -- The specification of the generic formal subprogram should always
2283 -- contain a formal type with unknown discriminants whose actual is
2284 -- a class-wide type, otherwise this indicates a failure in routine
2285 -- Has_Class_Wide_Actual.
2287 pragma Assert (Present (Formal_Typ));
2289 -- Step 2: Find the proper class-wide subprogram or primitive which
2290 -- corresponds to the renamed generic formal subprogram.
2292 CW_Prim_Op := Find_Primitive (Actual_Typ);
2293 CW_Prim_OK := Is_Suitable_Candidate (CW_Prim_Op);
2294 Root_Prim_Op := Find_Primitive (Root_Typ);
2295 Root_Prim_OK := Is_Suitable_Candidate (Root_Prim_Op);
2297 -- The class-wide actual type has two subprograms which correspond to
2298 -- the renamed generic formal subprogram:
2300 -- with procedure Prim_Op (Param : Formal_Typ);
2302 -- procedure Prim_Op (Param : Actual_Typ); -- may be inherited
2303 -- procedure Prim_Op (Param : Actual_Typ'Class);
2305 -- Even though the declaration of the two subprograms is legal, a
2306 -- call to either one is ambiguous and therefore illegal.
2308 if CW_Prim_OK and Root_Prim_OK then
2310 -- A user-defined primitive has precedence over a predefined one
2312 if Is_Internal (CW_Prim_Op)
2313 and then not Is_Internal (Root_Prim_Op)
2315 Prim_Op := Root_Prim_Op;
2317 elsif Is_Internal (Root_Prim_Op)
2318 and then not Is_Internal (CW_Prim_Op)
2320 Prim_Op := CW_Prim_Op;
2322 elsif CW_Prim_Op = Root_Prim_Op then
2323 Prim_Op := Root_Prim_Op;
2325 -- Otherwise both candidate subprograms are user-defined and
2330 ("ambiguous actual for generic subprogram &",
2332 Interpretation_Error (Root_Prim_Op);
2333 Interpretation_Error (CW_Prim_Op);
2337 elsif CW_Prim_OK and not Root_Prim_OK then
2338 Prim_Op := CW_Prim_Op;
2340 elsif not CW_Prim_OK and Root_Prim_OK then
2341 Prim_Op := Root_Prim_Op;
2343 -- An intrinsic equality may act as a suitable candidate in the case
2344 -- of a null type extension where the parent's equality is hidden. A
2345 -- call to an intrinsic equality is expanded as dispatching.
2347 elsif Present (Root_Prim_Op)
2348 and then Is_Intrinsic_Equality (Root_Prim_Op)
2350 Prim_Op := Root_Prim_Op;
2352 -- Otherwise there are no candidate subprograms. Let the caller
2353 -- diagnose the error.
2359 -- At this point resolution has taken place and the name is no longer
2360 -- overloaded. Mark the primitive as referenced.
2362 Set_Is_Overloaded (Name (N), False);
2363 Set_Referenced (Prim_Op);
2365 -- Step 3: Create the declaration and the body of the wrapper, insert
2366 -- all the pieces into the tree.
2369 Make_Subprogram_Declaration (Loc,
2370 Specification => Build_Spec (Ren_Id));
2371 Insert_Before_And_Analyze (N, Spec_Decl);
2373 -- If the operator carries an Eliminated pragma, indicate that the
2374 -- wrapper is also to be eliminated, to prevent spurious error when
2375 -- using gnatelim on programs that include box-initialization of
2376 -- equality operators.
2378 Wrap_Id := Defining_Entity (Spec_Decl);
2379 Set_Is_Eliminated (Wrap_Id, Is_Eliminated (Prim_Op));
2382 Make_Subprogram_Body (Loc,
2383 Specification => Build_Spec (Ren_Id),
2384 Declarations => New_List,
2385 Handled_Statement_Sequence =>
2386 Make_Handled_Sequence_Of_Statements (Loc,
2387 Statements => New_List (
2389 (Subp_Id => Prim_Op,
2391 Parameter_Specifications
2392 (Specification (Spec_Decl))))));
2394 -- The generated body does not freeze and must be analyzed when the
2395 -- class-wide wrapper is frozen. The body is only needed if expansion
2398 if Expander_Active then
2399 Append_Freeze_Action (Wrap_Id, Body_Decl);
2402 -- Step 4: The subprogram renaming aliases the wrapper
2404 Rewrite (Nam, New_Occurrence_Of (Wrap_Id, Loc));
2405 end Build_Class_Wide_Wrapper;
2407 --------------------------
2408 -- Check_Null_Exclusion --
2409 --------------------------
2411 procedure Check_Null_Exclusion
2415 Ren_Formal : Entity_Id;
2416 Sub_Formal : Entity_Id;
2421 Ren_Formal := First_Formal (Ren);
2422 Sub_Formal := First_Formal (Sub);
2423 while Present (Ren_Formal) and then Present (Sub_Formal) loop
2424 if Has_Null_Exclusion (Parent (Ren_Formal))
2426 not (Has_Null_Exclusion (Parent (Sub_Formal))
2427 or else Can_Never_Be_Null (Etype (Sub_Formal)))
2430 ("`NOT NULL` required for parameter &",
2431 Parent (Sub_Formal), Sub_Formal);
2434 Next_Formal (Ren_Formal);
2435 Next_Formal (Sub_Formal);
2438 -- Return profile check
2440 if Nkind (Parent (Ren)) = N_Function_Specification
2441 and then Nkind (Parent (Sub)) = N_Function_Specification
2442 and then Has_Null_Exclusion (Parent (Ren))
2443 and then not (Has_Null_Exclusion (Parent (Sub))
2444 or else Can_Never_Be_Null (Etype (Sub)))
2447 ("return must specify `NOT NULL`",
2448 Result_Definition (Parent (Sub)));
2450 end Check_Null_Exclusion;
2452 ---------------------------
2453 -- Freeze_Actual_Profile --
2454 ---------------------------
2456 procedure Freeze_Actual_Profile is
2458 Has_Untagged_Inc : Boolean;
2459 Instantiation_Node : constant Node_Id := Parent (N);
2462 if Ada_Version >= Ada_2012 then
2463 F := First_Formal (Formal_Spec);
2464 Has_Untagged_Inc := False;
2465 while Present (F) loop
2466 if Ekind (Etype (F)) = E_Incomplete_Type
2467 and then not Is_Tagged_Type (Etype (F))
2469 Has_Untagged_Inc := True;
2473 F := Next_Formal (F);
2476 if Ekind (Formal_Spec) = E_Function
2477 and then Ekind (Etype (Formal_Spec)) = E_Incomplete_Type
2478 and then not Is_Tagged_Type (Etype (F))
2480 Has_Untagged_Inc := True;
2483 if not Has_Untagged_Inc then
2484 F := First_Formal (Old_S);
2485 while Present (F) loop
2486 Freeze_Before (Instantiation_Node, Etype (F));
2488 if Is_Incomplete_Or_Private_Type (Etype (F))
2489 and then No (Underlying_Type (Etype (F)))
2491 -- Exclude generic types, or types derived from them.
2492 -- They will be frozen in the enclosing instance.
2494 if Is_Generic_Type (Etype (F))
2495 or else Is_Generic_Type (Root_Type (Etype (F)))
2500 ("type& must be frozen before this point",
2501 Instantiation_Node, Etype (F));
2505 F := Next_Formal (F);
2509 end Freeze_Actual_Profile;
2511 ---------------------------
2512 -- Has_Class_Wide_Actual --
2513 ---------------------------
2515 function Has_Class_Wide_Actual return Boolean is
2517 Formal_Typ : Entity_Id;
2521 Formal := First_Formal (Formal_Spec);
2522 while Present (Formal) loop
2523 Formal_Typ := Etype (Formal);
2525 if Has_Unknown_Discriminants (Formal_Typ)
2526 and then not Is_Class_Wide_Type (Formal_Typ)
2527 and then Is_Class_Wide_Type (Get_Instance_Of (Formal_Typ))
2532 Next_Formal (Formal);
2537 end Has_Class_Wide_Actual;
2539 -------------------------
2540 -- Original_Subprogram --
2541 -------------------------
2543 function Original_Subprogram (Subp : Entity_Id) return Entity_Id is
2544 Orig_Decl : Node_Id;
2545 Orig_Subp : Entity_Id;
2548 -- First case: renamed entity is itself a renaming
2550 if Present (Alias (Subp)) then
2551 return Alias (Subp);
2553 elsif Nkind (Unit_Declaration_Node (Subp)) = N_Subprogram_Declaration
2554 and then Present (Corresponding_Body (Unit_Declaration_Node (Subp)))
2556 -- Check if renamed entity is a renaming_as_body
2559 Unit_Declaration_Node
2560 (Corresponding_Body (Unit_Declaration_Node (Subp)));
2562 if Nkind (Orig_Decl) = N_Subprogram_Renaming_Declaration then
2563 Orig_Subp := Entity (Name (Orig_Decl));
2565 if Orig_Subp = Rename_Spec then
2567 -- Circularity detected
2572 return (Original_Subprogram (Orig_Subp));
2580 end Original_Subprogram;
2584 CW_Actual : constant Boolean := Has_Class_Wide_Actual;
2585 -- Ada 2012 (AI05-071, AI05-0131): True if the renaming is for a
2586 -- defaulted formal subprogram when the actual for a related formal
2587 -- type is class-wide.
2589 Inst_Node : Node_Id := Empty;
2592 -- Start of processing for Analyze_Subprogram_Renaming
2595 -- The subprogram renaming declaration may be subject to pragma Ghost
2596 -- with policy Ignore. Set the mode now to ensure that any nodes
2597 -- generated during analysis and expansion are properly flagged as
2602 -- We must test for the attribute renaming case before the Analyze
2603 -- call because otherwise Sem_Attr will complain that the attribute
2604 -- is missing an argument when it is analyzed.
2606 if Nkind (Nam) = N_Attribute_Reference then
2608 -- In the case of an abstract formal subprogram association, rewrite
2609 -- an actual given by a stream attribute as the name of the
2610 -- corresponding stream primitive of the type.
2612 -- In a generic context the stream operations are not generated, and
2613 -- this must be treated as a normal attribute reference, to be
2614 -- expanded in subsequent instantiations.
2617 and then Is_Abstract_Subprogram (Formal_Spec)
2618 and then Expander_Active
2621 Stream_Prim : Entity_Id;
2622 Prefix_Type : constant Entity_Id := Entity (Prefix (Nam));
2625 -- The class-wide forms of the stream attributes are not
2626 -- primitive dispatching operations (even though they
2627 -- internally dispatch to a stream attribute).
2629 if Is_Class_Wide_Type (Prefix_Type) then
2631 ("attribute must be a primitive dispatching operation",
2636 -- Retrieve the primitive subprogram associated with the
2637 -- attribute. This can only be a stream attribute, since those
2638 -- are the only ones that are dispatching (and the actual for
2639 -- an abstract formal subprogram must be dispatching
2643 case Attribute_Name (Nam) is
2646 Find_Prim_Op (Prefix_Type, TSS_Stream_Input);
2649 Find_Prim_Op (Prefix_Type, TSS_Stream_Output);
2652 Find_Prim_Op (Prefix_Type, TSS_Stream_Read);
2655 Find_Prim_Op (Prefix_Type, TSS_Stream_Write);
2658 ("attribute must be a primitive"
2659 & " dispatching operation", Nam);
2665 -- If no operation was found, and the type is limited,
2666 -- the user should have defined one.
2668 when Program_Error =>
2669 if Is_Limited_Type (Prefix_Type) then
2671 ("stream operation not defined for type&",
2675 -- Otherwise, compiler should have generated default
2682 -- Rewrite the attribute into the name of its corresponding
2683 -- primitive dispatching subprogram. We can then proceed with
2684 -- the usual processing for subprogram renamings.
2687 Prim_Name : constant Node_Id :=
2688 Make_Identifier (Sloc (Nam),
2689 Chars => Chars (Stream_Prim));
2691 Set_Entity (Prim_Name, Stream_Prim);
2692 Rewrite (Nam, Prim_Name);
2697 -- Normal processing for a renaming of an attribute
2700 Attribute_Renaming (N);
2705 -- Check whether this declaration corresponds to the instantiation
2706 -- of a formal subprogram.
2708 -- If this is an instantiation, the corresponding actual is frozen and
2709 -- error messages can be made more precise. If this is a default
2710 -- subprogram, the entity is already established in the generic, and is
2711 -- not retrieved by visibility. If it is a default with a box, the
2712 -- candidate interpretations, if any, have been collected when building
2713 -- the renaming declaration. If overloaded, the proper interpretation is
2714 -- determined in Find_Renamed_Entity. If the entity is an operator,
2715 -- Find_Renamed_Entity applies additional visibility checks.
2718 Inst_Node := Unit_Declaration_Node (Formal_Spec);
2720 -- Check whether the renaming is for a defaulted actual subprogram
2721 -- with a class-wide actual.
2723 -- The class-wide wrapper is not needed in GNATprove_Mode and there
2724 -- is an external axiomatization on the package.
2727 and then Box_Present (Inst_Node)
2731 Present (Containing_Package_With_Ext_Axioms (Formal_Spec)))
2733 Build_Class_Wide_Wrapper (New_S, Old_S);
2735 elsif Is_Entity_Name (Nam)
2736 and then Present (Entity (Nam))
2737 and then not Comes_From_Source (Nam)
2738 and then not Is_Overloaded (Nam)
2740 Old_S := Entity (Nam);
2741 New_S := Analyze_Subprogram_Specification (Spec);
2745 if Ekind (Entity (Nam)) = E_Operator then
2749 if Box_Present (Inst_Node) then
2750 Old_S := Find_Renamed_Entity (N, Name (N), New_S, Is_Actual);
2752 -- If there is an immediately visible homonym of the operator
2753 -- and the declaration has a default, this is worth a warning
2754 -- because the user probably did not intend to get the pre-
2755 -- defined operator, visible in the generic declaration. To
2756 -- find if there is an intended candidate, analyze the renaming
2757 -- again in the current context.
2759 elsif Scope (Old_S) = Standard_Standard
2760 and then Present (Default_Name (Inst_Node))
2763 Decl : constant Node_Id := New_Copy_Tree (N);
2767 Set_Entity (Name (Decl), Empty);
2768 Analyze (Name (Decl));
2770 Find_Renamed_Entity (Decl, Name (Decl), New_S, True);
2773 and then In_Open_Scopes (Scope (Hidden))
2774 and then Is_Immediately_Visible (Hidden)
2775 and then Comes_From_Source (Hidden)
2776 and then Hidden /= Old_S
2778 Error_Msg_Sloc := Sloc (Hidden);
2779 Error_Msg_N ("default subprogram is resolved " &
2780 "in the generic declaration " &
2781 "(RM 12.6(17))??", N);
2782 Error_Msg_NE ("\and will not use & #??", N, Hidden);
2790 New_S := Analyze_Subprogram_Specification (Spec);
2794 -- Renamed entity must be analyzed first, to avoid being hidden by
2795 -- new name (which might be the same in a generic instance).
2799 -- The renaming defines a new overloaded entity, which is analyzed
2800 -- like a subprogram declaration.
2802 New_S := Analyze_Subprogram_Specification (Spec);
2805 if Current_Scope /= Standard_Standard then
2806 Set_Is_Pure (New_S, Is_Pure (Current_Scope));
2809 -- Set SPARK mode from current context
2811 Set_SPARK_Pragma (New_S, SPARK_Mode_Pragma);
2812 Set_SPARK_Pragma_Inherited (New_S, True);
2814 Rename_Spec := Find_Corresponding_Spec (N);
2816 -- Case of Renaming_As_Body
2818 if Present (Rename_Spec) then
2820 -- Renaming declaration is the completion of the declaration of
2821 -- Rename_Spec. We build an actual body for it at the freezing point.
2823 Set_Corresponding_Spec (N, Rename_Spec);
2825 -- Deal with special case of stream functions of abstract types
2828 if Nkind (Unit_Declaration_Node (Rename_Spec)) =
2829 N_Abstract_Subprogram_Declaration
2831 -- Input stream functions are abstract if the object type is
2832 -- abstract. Similarly, all default stream functions for an
2833 -- interface type are abstract. However, these subprograms may
2834 -- receive explicit declarations in representation clauses, making
2835 -- the attribute subprograms usable as defaults in subsequent
2837 -- In this case we rewrite the declaration to make the subprogram
2838 -- non-abstract. We remove the previous declaration, and insert
2839 -- the new one at the point of the renaming, to prevent premature
2840 -- access to unfrozen types. The new declaration reuses the
2841 -- specification of the previous one, and must not be analyzed.
2844 (Is_Primitive (Entity (Nam))
2846 Is_Abstract_Type (Find_Dispatching_Type (Entity (Nam))));
2848 Old_Decl : constant Node_Id :=
2849 Unit_Declaration_Node (Rename_Spec);
2850 New_Decl : constant Node_Id :=
2851 Make_Subprogram_Declaration (Sloc (N),
2853 Relocate_Node (Specification (Old_Decl)));
2856 Insert_After (N, New_Decl);
2857 Set_Is_Abstract_Subprogram (Rename_Spec, False);
2858 Set_Analyzed (New_Decl);
2862 Set_Corresponding_Body (Unit_Declaration_Node (Rename_Spec), New_S);
2864 if Ada_Version = Ada_83 and then Comes_From_Source (N) then
2865 Error_Msg_N ("(Ada 83) renaming cannot serve as a body", N);
2868 Set_Convention (New_S, Convention (Rename_Spec));
2869 Check_Fully_Conformant (New_S, Rename_Spec);
2870 Set_Public_Status (New_S);
2872 -- The specification does not introduce new formals, but only
2873 -- repeats the formals of the original subprogram declaration.
2874 -- For cross-reference purposes, and for refactoring tools, we
2875 -- treat the formals of the renaming declaration as body formals.
2877 Reference_Body_Formals (Rename_Spec, New_S);
2879 -- Indicate that the entity in the declaration functions like the
2880 -- corresponding body, and is not a new entity. The body will be
2881 -- constructed later at the freeze point, so indicate that the
2882 -- completion has not been seen yet.
2884 Set_Ekind (New_S, E_Subprogram_Body);
2885 New_S := Rename_Spec;
2886 Set_Has_Completion (Rename_Spec, False);
2888 -- Ada 2005: check overriding indicator
2890 if Present (Overridden_Operation (Rename_Spec)) then
2891 if Must_Not_Override (Specification (N)) then
2893 ("subprogram& overrides inherited operation",
2896 Style_Check and then not Must_Override (Specification (N))
2898 Style.Missing_Overriding (N, Rename_Spec);
2901 elsif Must_Override (Specification (N)) then
2902 Error_Msg_NE ("subprogram& is not overriding", N, Rename_Spec);
2905 -- Normal subprogram renaming (not renaming as body)
2908 Generate_Definition (New_S);
2909 New_Overloaded_Entity (New_S);
2911 if Is_Entity_Name (Nam)
2912 and then Is_Intrinsic_Subprogram (Entity (Nam))
2916 Check_Delayed_Subprogram (New_S);
2920 -- There is no need for elaboration checks on the new entity, which may
2921 -- be called before the next freezing point where the body will appear.
2922 -- Elaboration checks refer to the real entity, not the one created by
2923 -- the renaming declaration.
2925 Set_Kill_Elaboration_Checks (New_S, True);
2927 -- If we had a previous error, indicate a completely is present to stop
2928 -- junk cascaded messages, but don't take any further action.
2930 if Etype (Nam) = Any_Type then
2931 Set_Has_Completion (New_S);
2934 -- Case where name has the form of a selected component
2936 elsif Nkind (Nam) = N_Selected_Component then
2938 -- A name which has the form A.B can designate an entry of task A, a
2939 -- protected operation of protected object A, or finally a primitive
2940 -- operation of object A. In the later case, A is an object of some
2941 -- tagged type, or an access type that denotes one such. To further
2942 -- distinguish these cases, note that the scope of a task entry or
2943 -- protected operation is type of the prefix.
2945 -- The prefix could be an overloaded function call that returns both
2946 -- kinds of operations. This overloading pathology is left to the
2947 -- dedicated reader ???
2950 T : constant Entity_Id := Etype (Prefix (Nam));
2958 and then Is_Tagged_Type (Designated_Type (T))))
2959 and then Scope (Entity (Selector_Name (Nam))) /= T
2961 Analyze_Renamed_Primitive_Operation
2962 (N, New_S, Present (Rename_Spec));
2966 -- Renamed entity is an entry or protected operation. For those
2967 -- cases an explicit body is built (at the point of freezing of
2968 -- this entity) that contains a call to the renamed entity.
2970 -- This is not allowed for renaming as body if the renamed
2971 -- spec is already frozen (see RM 8.5.4(5) for details).
2973 if Present (Rename_Spec) and then Is_Frozen (Rename_Spec) then
2975 ("renaming-as-body cannot rename entry as subprogram", N);
2977 ("\since & is already frozen (RM 8.5.4(5))",
2980 Analyze_Renamed_Entry (N, New_S, Present (Rename_Spec));
2987 -- Case where name is an explicit dereference X.all
2989 elsif Nkind (Nam) = N_Explicit_Dereference then
2991 -- Renamed entity is designated by access_to_subprogram expression.
2992 -- Must build body to encapsulate call, as in the entry case.
2994 Analyze_Renamed_Dereference (N, New_S, Present (Rename_Spec));
2997 -- Indexed component
2999 elsif Nkind (Nam) = N_Indexed_Component then
3000 Analyze_Renamed_Family_Member (N, New_S, Present (Rename_Spec));
3003 -- Character literal
3005 elsif Nkind (Nam) = N_Character_Literal then
3006 Analyze_Renamed_Character (N, New_S, Present (Rename_Spec));
3009 -- Only remaining case is where we have a non-entity name, or a renaming
3010 -- of some other non-overloadable entity.
3012 elsif not Is_Entity_Name (Nam)
3013 or else not Is_Overloadable (Entity (Nam))
3015 -- Do not mention the renaming if it comes from an instance
3017 if not Is_Actual then
3018 Error_Msg_N ("expect valid subprogram name in renaming", N);
3020 Error_Msg_NE ("no visible subprogram for formal&", N, Nam);
3026 -- Find the renamed entity that matches the given specification. Disable
3027 -- Ada_83 because there is no requirement of full conformance between
3028 -- renamed entity and new entity, even though the same circuit is used.
3030 -- This is a bit of an odd case, which introduces a really irregular use
3031 -- of Ada_Version[_Explicit]. Would be nice to find cleaner way to do
3034 Ada_Version := Ada_Version_Type'Max (Ada_Version, Ada_95);
3035 Ada_Version_Pragma := Empty;
3036 Ada_Version_Explicit := Ada_Version;
3039 Old_S := Find_Renamed_Entity (N, Name (N), New_S, Is_Actual);
3041 -- The visible operation may be an inherited abstract operation that
3042 -- was overridden in the private part, in which case a call will
3043 -- dispatch to the overriding operation. Use the overriding one in
3044 -- the renaming declaration, to prevent spurious errors below.
3046 if Is_Overloadable (Old_S)
3047 and then Is_Abstract_Subprogram (Old_S)
3048 and then No (DTC_Entity (Old_S))
3049 and then Present (Alias (Old_S))
3050 and then not Is_Abstract_Subprogram (Alias (Old_S))
3051 and then Present (Overridden_Operation (Alias (Old_S)))
3053 Old_S := Alias (Old_S);
3056 -- When the renamed subprogram is overloaded and used as an actual
3057 -- of a generic, its entity is set to the first available homonym.
3058 -- We must first disambiguate the name, then set the proper entity.
3060 if Is_Actual and then Is_Overloaded (Nam) then
3061 Set_Entity (Nam, Old_S);
3065 -- Most common case: subprogram renames subprogram. No body is generated
3066 -- in this case, so we must indicate the declaration is complete as is.
3067 -- and inherit various attributes of the renamed subprogram.
3069 if No (Rename_Spec) then
3070 Set_Has_Completion (New_S);
3071 Set_Is_Imported (New_S, Is_Imported (Entity (Nam)));
3072 Set_Is_Pure (New_S, Is_Pure (Entity (Nam)));
3073 Set_Is_Preelaborated (New_S, Is_Preelaborated (Entity (Nam)));
3075 -- A subprogram renaming is Ghost if the renamed entity is Ghost or
3076 -- the construct appears within a Ghost scope.
3078 if Is_Ghost_Entity (Entity (Nam)) or else Ghost_Mode > None then
3079 Set_Is_Ghost_Entity (New_S);
3082 -- Ada 2005 (AI-423): Check the consistency of null exclusions
3083 -- between a subprogram and its correct renaming.
3085 -- Note: the Any_Id check is a guard that prevents compiler crashes
3086 -- when performing a null exclusion check between a renaming and a
3087 -- renamed subprogram that has been found to be illegal.
3089 if Ada_Version >= Ada_2005 and then Entity (Nam) /= Any_Id then
3090 Check_Null_Exclusion
3092 Sub => Entity (Nam));
3095 -- Enforce the Ada 2005 rule that the renamed entity cannot require
3096 -- overriding. The flag Requires_Overriding is set very selectively
3097 -- and misses some other illegal cases. The additional conditions
3098 -- checked below are sufficient but not necessary ???
3100 -- The rule does not apply to the renaming generated for an actual
3101 -- subprogram in an instance.
3106 -- Guard against previous errors, and omit renamings of predefined
3109 elsif not Ekind_In (Old_S, E_Function, E_Procedure) then
3112 elsif Requires_Overriding (Old_S)
3114 (Is_Abstract_Subprogram (Old_S)
3115 and then Present (Find_Dispatching_Type (Old_S))
3117 not Is_Abstract_Type (Find_Dispatching_Type (Old_S)))
3120 ("renamed entity cannot be "
3121 & "subprogram that requires overriding (RM 8.5.4 (5.1))", N);
3125 if Old_S /= Any_Id then
3126 if Is_Actual and then From_Default (N) then
3128 -- This is an implicit reference to the default actual
3130 Generate_Reference (Old_S, Nam, Typ => 'i', Force => True);
3133 Generate_Reference (Old_S, Nam);
3136 Check_Internal_Protected_Use (N, Old_S);
3138 -- For a renaming-as-body, require subtype conformance, but if the
3139 -- declaration being completed has not been frozen, then inherit the
3140 -- convention of the renamed subprogram prior to checking conformance
3141 -- (unless the renaming has an explicit convention established; the
3142 -- rule stated in the RM doesn't seem to address this ???).
3144 if Present (Rename_Spec) then
3145 Generate_Reference (Rename_Spec, Defining_Entity (Spec), 'b');
3146 Style.Check_Identifier (Defining_Entity (Spec), Rename_Spec);
3148 if not Is_Frozen (Rename_Spec) then
3149 if not Has_Convention_Pragma (Rename_Spec) then
3150 Set_Convention (New_S, Convention (Old_S));
3153 if Ekind (Old_S) /= E_Operator then
3154 Check_Mode_Conformant (New_S, Old_S, Spec);
3157 if Original_Subprogram (Old_S) = Rename_Spec then
3158 Error_Msg_N ("unfrozen subprogram cannot rename itself ", N);
3161 Check_Subtype_Conformant (New_S, Old_S, Spec);
3164 Check_Frozen_Renaming (N, Rename_Spec);
3166 -- Check explicitly that renamed entity is not intrinsic, because
3167 -- in a generic the renamed body is not built. In this case,
3168 -- the renaming_as_body is a completion.
3170 if Inside_A_Generic then
3171 if Is_Frozen (Rename_Spec)
3172 and then Is_Intrinsic_Subprogram (Old_S)
3175 ("subprogram in renaming_as_body cannot be intrinsic",
3179 Set_Has_Completion (Rename_Spec);
3182 elsif Ekind (Old_S) /= E_Operator then
3184 -- If this a defaulted subprogram for a class-wide actual there is
3185 -- no check for mode conformance, given that the signatures don't
3186 -- match (the source mentions T but the actual mentions T'Class).
3190 elsif not Is_Actual or else No (Enclosing_Instance) then
3191 Check_Mode_Conformant (New_S, Old_S);
3194 if Is_Actual and then Error_Posted (New_S) then
3195 Error_Msg_NE ("invalid actual subprogram: & #!", N, Old_S);
3199 if No (Rename_Spec) then
3201 -- The parameter profile of the new entity is that of the renamed
3202 -- entity: the subtypes given in the specification are irrelevant.
3204 Inherit_Renamed_Profile (New_S, Old_S);
3206 -- A call to the subprogram is transformed into a call to the
3207 -- renamed entity. This is transitive if the renamed entity is
3208 -- itself a renaming.
3210 if Present (Alias (Old_S)) then
3211 Set_Alias (New_S, Alias (Old_S));
3213 Set_Alias (New_S, Old_S);
3216 -- Note that we do not set Is_Intrinsic_Subprogram if we have a
3217 -- renaming as body, since the entity in this case is not an
3218 -- intrinsic (it calls an intrinsic, but we have a real body for
3219 -- this call, and it is in this body that the required intrinsic
3220 -- processing will take place).
3222 -- Also, if this is a renaming of inequality, the renamed operator
3223 -- is intrinsic, but what matters is the corresponding equality
3224 -- operator, which may be user-defined.
3226 Set_Is_Intrinsic_Subprogram
3228 Is_Intrinsic_Subprogram (Old_S)
3230 (Chars (Old_S) /= Name_Op_Ne
3231 or else Ekind (Old_S) = E_Operator
3232 or else Is_Intrinsic_Subprogram
3233 (Corresponding_Equality (Old_S))));
3235 if Ekind (Alias (New_S)) = E_Operator then
3236 Set_Has_Delayed_Freeze (New_S, False);
3239 -- If the renaming corresponds to an association for an abstract
3240 -- formal subprogram, then various attributes must be set to
3241 -- indicate that the renaming is an abstract dispatching operation
3242 -- with a controlling type.
3244 if Is_Actual and then Is_Abstract_Subprogram (Formal_Spec) then
3246 -- Mark the renaming as abstract here, so Find_Dispatching_Type
3247 -- see it as corresponding to a generic association for a
3248 -- formal abstract subprogram
3250 Set_Is_Abstract_Subprogram (New_S);
3253 New_S_Ctrl_Type : constant Entity_Id :=
3254 Find_Dispatching_Type (New_S);
3255 Old_S_Ctrl_Type : constant Entity_Id :=
3256 Find_Dispatching_Type (Old_S);
3259 if Old_S_Ctrl_Type /= New_S_Ctrl_Type then
3261 ("actual must be dispatching subprogram for type&",
3262 Nam, New_S_Ctrl_Type);
3265 Set_Is_Dispatching_Operation (New_S);
3266 Check_Controlling_Formals (New_S_Ctrl_Type, New_S);
3268 -- If the actual in the formal subprogram is itself a
3269 -- formal abstract subprogram association, there's no
3270 -- dispatch table component or position to inherit.
3272 if Present (DTC_Entity (Old_S)) then
3273 Set_DTC_Entity (New_S, DTC_Entity (Old_S));
3274 Set_DT_Position_Value (New_S, DT_Position (Old_S));
3284 -- The following is illegal, because F hides whatever other F may
3286 -- function F (...) renames F;
3289 or else (Nkind (Nam) /= N_Expanded_Name
3290 and then Chars (Old_S) = Chars (New_S))
3292 Error_Msg_N ("subprogram cannot rename itself", N);
3294 -- This is illegal even if we use a selector:
3295 -- function F (...) renames Pkg.F;
3296 -- because F is still hidden.
3298 elsif Nkind (Nam) = N_Expanded_Name
3299 and then Entity (Prefix (Nam)) = Current_Scope
3300 and then Chars (Selector_Name (Nam)) = Chars (New_S)
3302 -- This is an error, but we overlook the error and accept the
3303 -- renaming if the special Overriding_Renamings mode is in effect.
3305 if not Overriding_Renamings then
3307 ("implicit operation& is not visible (RM 8.3 (15))",
3312 Set_Convention (New_S, Convention (Old_S));
3314 if Is_Abstract_Subprogram (Old_S) then
3315 if Present (Rename_Spec) then
3317 ("a renaming-as-body cannot rename an abstract subprogram",
3319 Set_Has_Completion (Rename_Spec);
3321 Set_Is_Abstract_Subprogram (New_S);
3325 Check_Library_Unit_Renaming (N, Old_S);
3327 -- Pathological case: procedure renames entry in the scope of its
3328 -- task. Entry is given by simple name, but body must be built for
3329 -- procedure. Of course if called it will deadlock.
3331 if Ekind (Old_S) = E_Entry then
3332 Set_Has_Completion (New_S, False);
3333 Set_Alias (New_S, Empty);
3337 Freeze_Before (N, Old_S);
3338 Freeze_Actual_Profile;
3339 Set_Has_Delayed_Freeze (New_S, False);
3340 Freeze_Before (N, New_S);
3342 -- An abstract subprogram is only allowed as an actual in the case
3343 -- where the formal subprogram is also abstract.
3345 if (Ekind (Old_S) = E_Procedure or else Ekind (Old_S) = E_Function)
3346 and then Is_Abstract_Subprogram (Old_S)
3347 and then not Is_Abstract_Subprogram (Formal_Spec)
3350 ("abstract subprogram not allowed as generic actual", Nam);
3355 -- A common error is to assume that implicit operators for types are
3356 -- defined in Standard, or in the scope of a subtype. In those cases
3357 -- where the renamed entity is given with an expanded name, it is
3358 -- worth mentioning that operators for the type are not declared in
3359 -- the scope given by the prefix.
3361 if Nkind (Nam) = N_Expanded_Name
3362 and then Nkind (Selector_Name (Nam)) = N_Operator_Symbol
3363 and then Scope (Entity (Nam)) = Standard_Standard
3366 T : constant Entity_Id :=
3367 Base_Type (Etype (First_Formal (New_S)));
3369 Error_Msg_Node_2 := Prefix (Nam);
3371 ("operator for type& is not declared in&", Prefix (Nam), T);
3376 ("no visible subprogram matches the specification for&",
3380 if Present (Candidate_Renaming) then
3387 F1 := First_Formal (Candidate_Renaming);
3388 F2 := First_Formal (New_S);
3389 T1 := First_Subtype (Etype (F1));
3390 while Present (F1) and then Present (F2) loop
3395 if Present (F1) and then Present (Default_Value (F1)) then
3396 if Present (Next_Formal (F1)) then
3398 ("\missing specification for &" &
3399 " and other formals with defaults", Spec, F1);
3402 ("\missing specification for &", Spec, F1);
3406 if Nkind (Nam) = N_Operator_Symbol
3407 and then From_Default (N)
3409 Error_Msg_Node_2 := T1;
3411 ("default & on & is not directly visible",
3418 -- Ada 2005 AI 404: if the new subprogram is dispatching, verify that
3419 -- controlling access parameters are known non-null for the renamed
3420 -- subprogram. Test also applies to a subprogram instantiation that
3421 -- is dispatching. Test is skipped if some previous error was detected
3422 -- that set Old_S to Any_Id.
3424 if Ada_Version >= Ada_2005
3425 and then Old_S /= Any_Id
3426 and then not Is_Dispatching_Operation (Old_S)
3427 and then Is_Dispatching_Operation (New_S)
3434 Old_F := First_Formal (Old_S);
3435 New_F := First_Formal (New_S);
3436 while Present (Old_F) loop
3437 if Ekind (Etype (Old_F)) = E_Anonymous_Access_Type
3438 and then Is_Controlling_Formal (New_F)
3439 and then not Can_Never_Be_Null (Old_F)
3441 Error_Msg_N ("access parameter is controlling,", New_F);
3443 ("\corresponding parameter of& "
3444 & "must be explicitly null excluding", New_F, Old_S);
3447 Next_Formal (Old_F);
3448 Next_Formal (New_F);
3453 -- A useful warning, suggested by Ada Bug Finder (Ada-Europe 2005)
3454 -- is to warn if an operator is being renamed as a different operator.
3455 -- If the operator is predefined, examine the kind of the entity, not
3456 -- the abbreviated declaration in Standard.
3458 if Comes_From_Source (N)
3459 and then Present (Old_S)
3460 and then (Nkind (Old_S) = N_Defining_Operator_Symbol
3461 or else Ekind (Old_S) = E_Operator)
3462 and then Nkind (New_S) = N_Defining_Operator_Symbol
3463 and then Chars (Old_S) /= Chars (New_S)
3466 ("& is being renamed as a different operator??", N, Old_S);
3469 -- Check for renaming of obsolescent subprogram
3471 Check_Obsolescent_2005_Entity (Entity (Nam), Nam);
3473 -- Another warning or some utility: if the new subprogram as the same
3474 -- name as the old one, the old one is not hidden by an outer homograph,
3475 -- the new one is not a public symbol, and the old one is otherwise
3476 -- directly visible, the renaming is superfluous.
3478 if Chars (Old_S) = Chars (New_S)
3479 and then Comes_From_Source (N)
3480 and then Scope (Old_S) /= Standard_Standard
3481 and then Warn_On_Redundant_Constructs
3482 and then (Is_Immediately_Visible (Old_S)
3483 or else Is_Potentially_Use_Visible (Old_S))
3484 and then Is_Overloadable (Current_Scope)
3485 and then Chars (Current_Scope) /= Chars (Old_S)
3488 ("redundant renaming, entity is directly visible?r?", Name (N));
3491 -- Implementation-defined aspect specifications can appear in a renaming
3492 -- declaration, but not language-defined ones. The call to procedure
3493 -- Analyze_Aspect_Specifications will take care of this error check.
3495 if Has_Aspects (N) then
3496 Analyze_Aspect_Specifications (N, New_S);
3499 Ada_Version := Save_AV;
3500 Ada_Version_Pragma := Save_AVP;
3501 Ada_Version_Explicit := Save_AV_Exp;
3503 -- In GNATprove mode, the renamings of actual subprograms are replaced
3504 -- with wrapper functions that make it easier to propagate axioms to the
3505 -- points of call within an instance. Wrappers are generated if formal
3506 -- subprogram is subject to axiomatization.
3508 -- The types in the wrapper profiles are obtained from (instances of)
3509 -- the types of the formal subprogram.
3512 and then GNATprove_Mode
3513 and then Present (Containing_Package_With_Ext_Axioms (Formal_Spec))
3514 and then not Inside_A_Generic
3516 if Ekind (Old_S) = E_Function then
3517 Rewrite (N, Build_Function_Wrapper (Formal_Spec, Old_S));
3520 elsif Ekind (Old_S) = E_Operator then
3521 Rewrite (N, Build_Operator_Wrapper (Formal_Spec, Old_S));
3525 end Analyze_Subprogram_Renaming;
3527 -------------------------
3528 -- Analyze_Use_Package --
3529 -------------------------
3531 -- Resolve the package names in the use clause, and make all the visible
3532 -- entities defined in the package potentially use-visible. If the package
3533 -- is already in use from a previous use clause, its visible entities are
3534 -- already use-visible. In that case, mark the occurrence as a redundant
3535 -- use. If the package is an open scope, i.e. if the use clause occurs
3536 -- within the package itself, ignore it.
3538 procedure Analyze_Use_Package (N : Node_Id) is
3539 Pack_Name : Node_Id;
3542 -- Start of processing for Analyze_Use_Package
3545 Check_SPARK_05_Restriction ("use clause is not allowed", N);
3547 Set_Hidden_By_Use_Clause (N, No_Elist);
3549 -- Use clause not allowed in a spec of a predefined package declaration
3550 -- except that packages whose file name starts a-n are OK (these are
3551 -- children of Ada.Numerics, which are never loaded by Rtsfind).
3553 if Is_Predefined_File_Name (Unit_File_Name (Current_Sem_Unit))
3554 and then Name_Buffer (1 .. 3) /= "a-n"
3556 Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Declaration
3558 Error_Msg_N ("use clause not allowed in predefined spec", N);
3561 -- Chain clause to list of use clauses in current scope
3563 if Nkind (Parent (N)) /= N_Compilation_Unit then
3564 Chain_Use_Clause (N);
3567 -- Loop through package names to identify referenced packages
3569 Pack_Name := First (Names (N));
3570 while Present (Pack_Name) loop
3571 Analyze (Pack_Name);
3573 if Nkind (Parent (N)) = N_Compilation_Unit
3574 and then Nkind (Pack_Name) = N_Expanded_Name
3580 Pref := Prefix (Pack_Name);
3581 while Nkind (Pref) = N_Expanded_Name loop
3582 Pref := Prefix (Pref);
3585 if Entity (Pref) = Standard_Standard then
3587 ("predefined package Standard cannot appear"
3588 & " in a context clause", Pref);
3596 -- Loop through package names to mark all entities as potentially
3599 Pack_Name := First (Names (N));
3600 while Present (Pack_Name) loop
3601 if Is_Entity_Name (Pack_Name) then
3602 Pack := Entity (Pack_Name);
3604 if Ekind (Pack) /= E_Package and then Etype (Pack) /= Any_Type then
3605 if Ekind (Pack) = E_Generic_Package then
3606 Error_Msg_N -- CODEFIX
3607 ("a generic package is not allowed in a use clause",
3610 elsif Ekind_In (Pack, E_Generic_Function, E_Generic_Package)
3612 Error_Msg_N -- CODEFIX
3613 ("a generic subprogram is not allowed in a use clause",
3616 elsif Ekind_In (Pack, E_Function, E_Procedure, E_Operator) then
3617 Error_Msg_N -- CODEFIX
3618 ("a subprogram is not allowed in a use clause",
3622 Error_Msg_N ("& is not allowed in a use clause", Pack_Name);
3626 if Nkind (Parent (N)) = N_Compilation_Unit then
3627 Check_In_Previous_With_Clause (N, Pack_Name);
3630 if Applicable_Use (Pack_Name) then
3631 Use_One_Package (Pack, N);
3635 -- Report error because name denotes something other than a package
3638 Error_Msg_N ("& is not a package", Pack_Name);
3643 end Analyze_Use_Package;
3645 ----------------------
3646 -- Analyze_Use_Type --
3647 ----------------------
3649 procedure Analyze_Use_Type (N : Node_Id) is
3654 Set_Hidden_By_Use_Clause (N, No_Elist);
3656 -- Chain clause to list of use clauses in current scope
3658 if Nkind (Parent (N)) /= N_Compilation_Unit then
3659 Chain_Use_Clause (N);
3662 -- If the Used_Operations list is already initialized, the clause has
3663 -- been analyzed previously, and it is begin reinstalled, for example
3664 -- when the clause appears in a package spec and we are compiling the
3665 -- corresponding package body. In that case, make the entities on the
3666 -- existing list use_visible, and mark the corresponding types In_Use.
3668 if Present (Used_Operations (N)) then
3674 Mark := First (Subtype_Marks (N));
3675 while Present (Mark) loop
3676 Use_One_Type (Mark, Installed => True);
3680 Elmt := First_Elmt (Used_Operations (N));
3681 while Present (Elmt) loop
3682 Set_Is_Potentially_Use_Visible (Node (Elmt));
3690 -- Otherwise, create new list and attach to it the operations that
3691 -- are made use-visible by the clause.
3693 Set_Used_Operations (N, New_Elmt_List);
3694 Id := First (Subtype_Marks (N));
3695 while Present (Id) loop
3699 if E /= Any_Type then
3702 if Nkind (Parent (N)) = N_Compilation_Unit then
3703 if Nkind (Id) = N_Identifier then
3704 Error_Msg_N ("type is not directly visible", Id);
3706 elsif Is_Child_Unit (Scope (E))
3707 and then Scope (E) /= System_Aux_Id
3709 Check_In_Previous_With_Clause (N, Prefix (Id));
3714 -- If the use_type_clause appears in a compilation unit context,
3715 -- check whether it comes from a unit that may appear in a
3716 -- limited_with_clause, for a better error message.
3718 if Nkind (Parent (N)) = N_Compilation_Unit
3719 and then Nkind (Id) /= N_Identifier
3725 function Mentioned (Nam : Node_Id) return Boolean;
3726 -- Check whether the prefix of expanded name for the type
3727 -- appears in the prefix of some limited_with_clause.
3733 function Mentioned (Nam : Node_Id) return Boolean is
3735 return Nkind (Name (Item)) = N_Selected_Component
3736 and then Chars (Prefix (Name (Item))) = Chars (Nam);
3740 Pref := Prefix (Id);
3741 Item := First (Context_Items (Parent (N)));
3742 while Present (Item) and then Item /= N loop
3743 if Nkind (Item) = N_With_Clause
3744 and then Limited_Present (Item)
3745 and then Mentioned (Pref)
3748 (Get_Msg_Id, "premature usage of incomplete type");
3759 end Analyze_Use_Type;
3761 --------------------
3762 -- Applicable_Use --
3763 --------------------
3765 function Applicable_Use (Pack_Name : Node_Id) return Boolean is
3766 Pack : constant Entity_Id := Entity (Pack_Name);
3769 if In_Open_Scopes (Pack) then
3770 if Warn_On_Redundant_Constructs and then Pack = Current_Scope then
3771 Error_Msg_NE -- CODEFIX
3772 ("& is already use-visible within itself?r?", Pack_Name, Pack);
3777 elsif In_Use (Pack) then
3778 Note_Redundant_Use (Pack_Name);
3781 elsif Present (Renamed_Object (Pack))
3782 and then In_Use (Renamed_Object (Pack))
3784 Note_Redundant_Use (Pack_Name);
3792 ------------------------
3793 -- Attribute_Renaming --
3794 ------------------------
3796 procedure Attribute_Renaming (N : Node_Id) is
3797 Loc : constant Source_Ptr := Sloc (N);
3798 Nam : constant Node_Id := Name (N);
3799 Spec : constant Node_Id := Specification (N);
3800 New_S : constant Entity_Id := Defining_Unit_Name (Spec);
3801 Aname : constant Name_Id := Attribute_Name (Nam);
3803 Form_Num : Nat := 0;
3804 Expr_List : List_Id := No_List;
3806 Attr_Node : Node_Id;
3807 Body_Node : Node_Id;
3808 Param_Spec : Node_Id;
3811 Generate_Definition (New_S);
3813 -- This procedure is called in the context of subprogram renaming, and
3814 -- thus the attribute must be one that is a subprogram. All of those
3815 -- have at least one formal parameter, with the exceptions of the GNAT
3816 -- attribute 'Img, which GNAT treats as renameable.
3818 if not Is_Non_Empty_List (Parameter_Specifications (Spec)) then
3819 if Aname /= Name_Img then
3821 ("subprogram renaming an attribute must have formals", N);
3826 Param_Spec := First (Parameter_Specifications (Spec));
3827 while Present (Param_Spec) loop
3828 Form_Num := Form_Num + 1;
3830 if Nkind (Parameter_Type (Param_Spec)) /= N_Access_Definition then
3831 Find_Type (Parameter_Type (Param_Spec));
3833 -- The profile of the new entity denotes the base type (s) of
3834 -- the types given in the specification. For access parameters
3835 -- there are no subtypes involved.
3837 Rewrite (Parameter_Type (Param_Spec),
3839 (Base_Type (Entity (Parameter_Type (Param_Spec))), Loc));
3842 if No (Expr_List) then
3843 Expr_List := New_List;
3846 Append_To (Expr_List,
3847 Make_Identifier (Loc,
3848 Chars => Chars (Defining_Identifier (Param_Spec))));
3850 -- The expressions in the attribute reference are not freeze
3851 -- points. Neither is the attribute as a whole, see below.
3853 Set_Must_Not_Freeze (Last (Expr_List));
3858 -- Immediate error if too many formals. Other mismatches in number or
3859 -- types of parameters are detected when we analyze the body of the
3860 -- subprogram that we construct.
3862 if Form_Num > 2 then
3863 Error_Msg_N ("too many formals for attribute", N);
3865 -- Error if the attribute reference has expressions that look like
3866 -- formal parameters.
3868 elsif Present (Expressions (Nam)) then
3869 Error_Msg_N ("illegal expressions in attribute reference", Nam);
3872 Nam_In (Aname, Name_Compose, Name_Exponent, Name_Leading_Part,
3873 Name_Pos, Name_Round, Name_Scaling,
3876 if Nkind (N) = N_Subprogram_Renaming_Declaration
3877 and then Present (Corresponding_Formal_Spec (N))
3880 ("generic actual cannot be attribute involving universal type",
3884 ("attribute involving a universal type cannot be renamed",
3889 -- Rewrite attribute node to have a list of expressions corresponding to
3890 -- the subprogram formals. A renaming declaration is not a freeze point,
3891 -- and the analysis of the attribute reference should not freeze the
3892 -- type of the prefix. We use the original node in the renaming so that
3893 -- its source location is preserved, and checks on stream attributes are
3894 -- properly applied.
3896 Attr_Node := Relocate_Node (Nam);
3897 Set_Expressions (Attr_Node, Expr_List);
3899 Set_Must_Not_Freeze (Attr_Node);
3900 Set_Must_Not_Freeze (Prefix (Nam));
3902 -- Case of renaming a function
3904 if Nkind (Spec) = N_Function_Specification then
3905 if Is_Procedure_Attribute_Name (Aname) then
3906 Error_Msg_N ("attribute can only be renamed as procedure", Nam);
3910 Find_Type (Result_Definition (Spec));
3911 Rewrite (Result_Definition (Spec),
3913 (Base_Type (Entity (Result_Definition (Spec))), Loc));
3916 Make_Subprogram_Body (Loc,
3917 Specification => Spec,
3918 Declarations => New_List,
3919 Handled_Statement_Sequence =>
3920 Make_Handled_Sequence_Of_Statements (Loc,
3921 Statements => New_List (
3922 Make_Simple_Return_Statement (Loc,
3923 Expression => Attr_Node))));
3925 -- Case of renaming a procedure
3928 if not Is_Procedure_Attribute_Name (Aname) then
3929 Error_Msg_N ("attribute can only be renamed as function", Nam);
3934 Make_Subprogram_Body (Loc,
3935 Specification => Spec,
3936 Declarations => New_List,
3937 Handled_Statement_Sequence =>
3938 Make_Handled_Sequence_Of_Statements (Loc,
3939 Statements => New_List (Attr_Node)));
3942 -- In case of tagged types we add the body of the generated function to
3943 -- the freezing actions of the type (because in the general case such
3944 -- type is still not frozen). We exclude from this processing generic
3945 -- formal subprograms found in instantiations.
3947 -- We must exclude VM targets and restricted run-time libraries because
3948 -- entity AST_Handler is defined in package System.Aux_Dec which is not
3949 -- available in those platforms. Note that we cannot use the function
3950 -- Restricted_Profile (instead of Configurable_Run_Time_Mode) because
3951 -- the ZFP run-time library is not defined as a profile, and we do not
3952 -- want to deal with AST_Handler in ZFP mode.
3954 if VM_Target = No_VM
3955 and then not Configurable_Run_Time_Mode
3956 and then not Present (Corresponding_Formal_Spec (N))
3957 and then Etype (Nam) /= RTE (RE_AST_Handler)
3960 P : constant Node_Id := Prefix (Nam);
3963 -- The prefix of 'Img is an object that is evaluated for each call
3964 -- of the function that renames it.
3966 if Aname = Name_Img then
3967 Preanalyze_And_Resolve (P);
3969 -- For all other attribute renamings, the prefix is a subtype
3975 -- If the target type is not yet frozen, add the body to the
3976 -- actions to be elaborated at freeze time.
3978 if Is_Tagged_Type (Etype (P))
3979 and then In_Open_Scopes (Scope (Etype (P)))
3981 Ensure_Freeze_Node (Etype (P));
3982 Append_Freeze_Action (Etype (P), Body_Node);
3984 Rewrite (N, Body_Node);
3986 Set_Etype (New_S, Base_Type (Etype (New_S)));
3990 -- Generic formal subprograms or AST_Handler renaming
3993 Rewrite (N, Body_Node);
3995 Set_Etype (New_S, Base_Type (Etype (New_S)));
3998 if Is_Compilation_Unit (New_S) then
4000 ("a library unit can only rename another library unit", N);
4003 -- We suppress elaboration warnings for the resulting entity, since
4004 -- clearly they are not needed, and more particularly, in the case
4005 -- of a generic formal subprogram, the resulting entity can appear
4006 -- after the instantiation itself, and thus look like a bogus case
4007 -- of access before elaboration.
4009 Set_Suppress_Elaboration_Warnings (New_S);
4011 end Attribute_Renaming;
4013 ----------------------
4014 -- Chain_Use_Clause --
4015 ----------------------
4017 procedure Chain_Use_Clause (N : Node_Id) is
4019 Level : Int := Scope_Stack.Last;
4022 if not Is_Compilation_Unit (Current_Scope)
4023 or else not Is_Child_Unit (Current_Scope)
4025 null; -- Common case
4027 elsif Defining_Entity (Parent (N)) = Current_Scope then
4028 null; -- Common case for compilation unit
4031 -- If declaration appears in some other scope, it must be in some
4032 -- parent unit when compiling a child.
4034 Pack := Defining_Entity (Parent (N));
4035 if not In_Open_Scopes (Pack) then
4036 null; -- default as well
4038 -- If the use clause appears in an ancestor and we are in the
4039 -- private part of the immediate parent, the use clauses are
4040 -- already installed.
4042 elsif Pack /= Scope (Current_Scope)
4043 and then In_Private_Part (Scope (Current_Scope))
4048 -- Find entry for parent unit in scope stack
4050 while Scope_Stack.Table (Level).Entity /= Pack loop
4056 Set_Next_Use_Clause (N,
4057 Scope_Stack.Table (Level).First_Use_Clause);
4058 Scope_Stack.Table (Level).First_Use_Clause := N;
4059 end Chain_Use_Clause;
4061 ---------------------------
4062 -- Check_Frozen_Renaming --
4063 ---------------------------
4065 procedure Check_Frozen_Renaming (N : Node_Id; Subp : Entity_Id) is
4070 if Is_Frozen (Subp) and then not Has_Completion (Subp) then
4073 (Parent (Declaration_Node (Subp)), Defining_Entity (N));
4075 if Is_Entity_Name (Name (N)) then
4076 Old_S := Entity (Name (N));
4078 if not Is_Frozen (Old_S)
4079 and then Operating_Mode /= Check_Semantics
4081 Append_Freeze_Action (Old_S, B_Node);
4083 Insert_After (N, B_Node);
4087 if Is_Intrinsic_Subprogram (Old_S) and then not In_Instance then
4089 ("subprogram used in renaming_as_body cannot be intrinsic",
4094 Insert_After (N, B_Node);
4098 end Check_Frozen_Renaming;
4100 -------------------------------
4101 -- Set_Entity_Or_Discriminal --
4102 -------------------------------
4104 procedure Set_Entity_Or_Discriminal (N : Node_Id; E : Entity_Id) is
4108 -- If the entity is not a discriminant, or else expansion is disabled,
4109 -- simply set the entity.
4111 if not In_Spec_Expression
4112 or else Ekind (E) /= E_Discriminant
4113 or else Inside_A_Generic
4115 Set_Entity_With_Checks (N, E);
4117 -- The replacement of a discriminant by the corresponding discriminal
4118 -- is not done for a task discriminant that appears in a default
4119 -- expression of an entry parameter. See Exp_Ch2.Expand_Discriminant
4120 -- for details on their handling.
4122 elsif Is_Concurrent_Type (Scope (E)) then
4125 and then not Nkind_In (P, N_Parameter_Specification,
4126 N_Component_Declaration)
4132 and then Nkind (P) = N_Parameter_Specification
4137 Set_Entity (N, Discriminal (E));
4140 -- Otherwise, this is a discriminant in a context in which
4141 -- it is a reference to the corresponding parameter of the
4142 -- init proc for the enclosing type.
4145 Set_Entity (N, Discriminal (E));
4147 end Set_Entity_Or_Discriminal;
4149 -----------------------------------
4150 -- Check_In_Previous_With_Clause --
4151 -----------------------------------
4153 procedure Check_In_Previous_With_Clause
4157 Pack : constant Entity_Id := Entity (Original_Node (Nam));
4162 Item := First (Context_Items (Parent (N)));
4163 while Present (Item) and then Item /= N loop
4164 if Nkind (Item) = N_With_Clause
4166 -- Protect the frontend against previous critical errors
4168 and then Nkind (Name (Item)) /= N_Selected_Component
4169 and then Entity (Name (Item)) = Pack
4173 -- Find root library unit in with_clause
4175 while Nkind (Par) = N_Expanded_Name loop
4176 Par := Prefix (Par);
4179 if Is_Child_Unit (Entity (Original_Node (Par))) then
4180 Error_Msg_NE ("& is not directly visible", Par, Entity (Par));
4189 -- On exit, package is not mentioned in a previous with_clause.
4190 -- Check if its prefix is.
4192 if Nkind (Nam) = N_Expanded_Name then
4193 Check_In_Previous_With_Clause (N, Prefix (Nam));
4195 elsif Pack /= Any_Id then
4196 Error_Msg_NE ("& is not visible", Nam, Pack);
4198 end Check_In_Previous_With_Clause;
4200 ---------------------------------
4201 -- Check_Library_Unit_Renaming --
4202 ---------------------------------
4204 procedure Check_Library_Unit_Renaming (N : Node_Id; Old_E : Entity_Id) is
4208 if Nkind (Parent (N)) /= N_Compilation_Unit then
4211 -- Check for library unit. Note that we used to check for the scope
4212 -- being Standard here, but that was wrong for Standard itself.
4214 elsif not Is_Compilation_Unit (Old_E)
4215 and then not Is_Child_Unit (Old_E)
4217 Error_Msg_N ("renamed unit must be a library unit", Name (N));
4219 -- Entities defined in Standard (operators and boolean literals) cannot
4220 -- be renamed as library units.
4222 elsif Scope (Old_E) = Standard_Standard
4223 and then Sloc (Old_E) = Standard_Location
4225 Error_Msg_N ("renamed unit must be a library unit", Name (N));
4227 elsif Present (Parent_Spec (N))
4228 and then Nkind (Unit (Parent_Spec (N))) = N_Generic_Package_Declaration
4229 and then not Is_Child_Unit (Old_E)
4232 ("renamed unit must be a child unit of generic parent", Name (N));
4234 elsif Nkind (N) in N_Generic_Renaming_Declaration
4235 and then Nkind (Name (N)) = N_Expanded_Name
4236 and then Is_Generic_Instance (Entity (Prefix (Name (N))))
4237 and then Is_Generic_Unit (Old_E)
4240 ("renamed generic unit must be a library unit", Name (N));
4242 elsif Is_Package_Or_Generic_Package (Old_E) then
4244 -- Inherit categorization flags
4246 New_E := Defining_Entity (N);
4247 Set_Is_Pure (New_E, Is_Pure (Old_E));
4248 Set_Is_Preelaborated (New_E, Is_Preelaborated (Old_E));
4249 Set_Is_Remote_Call_Interface (New_E,
4250 Is_Remote_Call_Interface (Old_E));
4251 Set_Is_Remote_Types (New_E, Is_Remote_Types (Old_E));
4252 Set_Is_Shared_Passive (New_E, Is_Shared_Passive (Old_E));
4254 end Check_Library_Unit_Renaming;
4256 ------------------------
4257 -- Enclosing_Instance --
4258 ------------------------
4260 function Enclosing_Instance return Entity_Id is
4264 if not Is_Generic_Instance (Current_Scope) then
4268 S := Scope (Current_Scope);
4269 while S /= Standard_Standard loop
4270 if Is_Generic_Instance (S) then
4278 end Enclosing_Instance;
4284 procedure End_Scope is
4290 Id := First_Entity (Current_Scope);
4291 while Present (Id) loop
4292 -- An entity in the current scope is not necessarily the first one
4293 -- on its homonym chain. Find its predecessor if any,
4294 -- If it is an internal entity, it will not be in the visibility
4295 -- chain altogether, and there is nothing to unchain.
4297 if Id /= Current_Entity (Id) then
4298 Prev := Current_Entity (Id);
4299 while Present (Prev)
4300 and then Present (Homonym (Prev))
4301 and then Homonym (Prev) /= Id
4303 Prev := Homonym (Prev);
4306 -- Skip to end of loop if Id is not in the visibility chain
4308 if No (Prev) or else Homonym (Prev) /= Id then
4316 Set_Is_Immediately_Visible (Id, False);
4318 Outer := Homonym (Id);
4319 while Present (Outer) and then Scope (Outer) = Current_Scope loop
4320 Outer := Homonym (Outer);
4323 -- Reset homonym link of other entities, but do not modify link
4324 -- between entities in current scope, so that the back-end can have
4325 -- a proper count of local overloadings.
4328 Set_Name_Entity_Id (Chars (Id), Outer);
4330 elsif Scope (Prev) /= Scope (Id) then
4331 Set_Homonym (Prev, Outer);
4338 -- If the scope generated freeze actions, place them before the
4339 -- current declaration and analyze them. Type declarations and
4340 -- the bodies of initialization procedures can generate such nodes.
4341 -- We follow the parent chain until we reach a list node, which is
4342 -- the enclosing list of declarations. If the list appears within
4343 -- a protected definition, move freeze nodes outside the protected
4347 (Scope_Stack.Table (Scope_Stack.Last).Pending_Freeze_Actions)
4351 L : constant List_Id := Scope_Stack.Table
4352 (Scope_Stack.Last).Pending_Freeze_Actions;
4355 if Is_Itype (Current_Scope) then
4356 Decl := Associated_Node_For_Itype (Current_Scope);
4358 Decl := Parent (Current_Scope);
4363 while not (Is_List_Member (Decl))
4364 or else Nkind_In (Parent (Decl), N_Protected_Definition,
4367 Decl := Parent (Decl);
4370 Insert_List_Before_And_Analyze (Decl, L);
4378 ---------------------
4379 -- End_Use_Clauses --
4380 ---------------------
4382 procedure End_Use_Clauses (Clause : Node_Id) is
4386 -- Remove Use_Type clauses first, because they affect the
4387 -- visibility of operators in subsequent used packages.
4390 while Present (U) loop
4391 if Nkind (U) = N_Use_Type_Clause then
4395 Next_Use_Clause (U);
4399 while Present (U) loop
4400 if Nkind (U) = N_Use_Package_Clause then
4401 End_Use_Package (U);
4404 Next_Use_Clause (U);
4406 end End_Use_Clauses;
4408 ---------------------
4409 -- End_Use_Package --
4410 ---------------------
4412 procedure End_Use_Package (N : Node_Id) is
4413 Pack_Name : Node_Id;
4418 function Is_Primitive_Operator_In_Use
4420 F : Entity_Id) return Boolean;
4421 -- Check whether Op is a primitive operator of a use-visible type
4423 ----------------------------------
4424 -- Is_Primitive_Operator_In_Use --
4425 ----------------------------------
4427 function Is_Primitive_Operator_In_Use
4429 F : Entity_Id) return Boolean
4431 T : constant Entity_Id := Base_Type (Etype (F));
4433 return In_Use (T) and then Scope (T) = Scope (Op);
4434 end Is_Primitive_Operator_In_Use;
4436 -- Start of processing for End_Use_Package
4439 Pack_Name := First (Names (N));
4440 while Present (Pack_Name) loop
4442 -- Test that Pack_Name actually denotes a package before processing
4444 if Is_Entity_Name (Pack_Name)
4445 and then Ekind (Entity (Pack_Name)) = E_Package
4447 Pack := Entity (Pack_Name);
4449 if In_Open_Scopes (Pack) then
4452 elsif not Redundant_Use (Pack_Name) then
4453 Set_In_Use (Pack, False);
4454 Set_Current_Use_Clause (Pack, Empty);
4456 Id := First_Entity (Pack);
4457 while Present (Id) loop
4459 -- Preserve use-visibility of operators that are primitive
4460 -- operators of a type that is use-visible through an active
4463 if Nkind (Id) = N_Defining_Operator_Symbol
4465 (Is_Primitive_Operator_In_Use (Id, First_Formal (Id))
4467 (Present (Next_Formal (First_Formal (Id)))
4469 Is_Primitive_Operator_In_Use
4470 (Id, Next_Formal (First_Formal (Id)))))
4474 Set_Is_Potentially_Use_Visible (Id, False);
4477 if Is_Private_Type (Id)
4478 and then Present (Full_View (Id))
4480 Set_Is_Potentially_Use_Visible (Full_View (Id), False);
4486 if Present (Renamed_Object (Pack)) then
4487 Set_In_Use (Renamed_Object (Pack), False);
4488 Set_Current_Use_Clause (Renamed_Object (Pack), Empty);
4491 if Chars (Pack) = Name_System
4492 and then Scope (Pack) = Standard_Standard
4493 and then Present_System_Aux
4495 Id := First_Entity (System_Aux_Id);
4496 while Present (Id) loop
4497 Set_Is_Potentially_Use_Visible (Id, False);
4499 if Is_Private_Type (Id)
4500 and then Present (Full_View (Id))
4502 Set_Is_Potentially_Use_Visible (Full_View (Id), False);
4508 Set_In_Use (System_Aux_Id, False);
4512 Set_Redundant_Use (Pack_Name, False);
4519 if Present (Hidden_By_Use_Clause (N)) then
4520 Elmt := First_Elmt (Hidden_By_Use_Clause (N));
4521 while Present (Elmt) loop
4523 E : constant Entity_Id := Node (Elmt);
4526 -- Reset either Use_Visibility or Direct_Visibility, depending
4527 -- on how the entity was hidden by the use clause.
4529 if In_Use (Scope (E))
4530 and then Used_As_Generic_Actual (Scope (E))
4532 Set_Is_Potentially_Use_Visible (Node (Elmt));
4534 Set_Is_Immediately_Visible (Node (Elmt));
4541 Set_Hidden_By_Use_Clause (N, No_Elist);
4543 end End_Use_Package;
4549 procedure End_Use_Type (N : Node_Id) is
4554 -- Start of processing for End_Use_Type
4557 Id := First (Subtype_Marks (N));
4558 while Present (Id) loop
4560 -- A call to Rtsfind may occur while analyzing a use_type clause,
4561 -- in which case the type marks are not resolved yet, and there is
4562 -- nothing to remove.
4564 if not Is_Entity_Name (Id) or else No (Entity (Id)) then
4570 if T = Any_Type or else From_Limited_With (T) then
4573 -- Note that the use_type clause may mention a subtype of the type
4574 -- whose primitive operations have been made visible. Here as
4575 -- elsewhere, it is the base type that matters for visibility.
4577 elsif In_Open_Scopes (Scope (Base_Type (T))) then
4580 elsif not Redundant_Use (Id) then
4581 Set_In_Use (T, False);
4582 Set_In_Use (Base_Type (T), False);
4583 Set_Current_Use_Clause (T, Empty);
4584 Set_Current_Use_Clause (Base_Type (T), Empty);
4591 if Is_Empty_Elmt_List (Used_Operations (N)) then
4595 Elmt := First_Elmt (Used_Operations (N));
4596 while Present (Elmt) loop
4597 Set_Is_Potentially_Use_Visible (Node (Elmt), False);
4603 ----------------------
4604 -- Find_Direct_Name --
4605 ----------------------
4607 procedure Find_Direct_Name (N : Node_Id) is
4612 Inst : Entity_Id := Empty;
4613 -- Enclosing instance, if any
4615 Homonyms : Entity_Id;
4616 -- Saves start of homonym chain
4618 Nvis_Entity : Boolean;
4619 -- Set True to indicate that there is at least one entity on the homonym
4620 -- chain which, while not visible, is visible enough from the user point
4621 -- of view to warrant an error message of "not visible" rather than
4624 Nvis_Is_Private_Subprg : Boolean := False;
4625 -- Ada 2005 (AI-262): Set True to indicate that a form of Beaujolais
4626 -- effect concerning library subprograms has been detected. Used to
4627 -- generate the precise error message.
4629 function From_Actual_Package (E : Entity_Id) return Boolean;
4630 -- Returns true if the entity is an actual for a package that is itself
4631 -- an actual for a formal package of the current instance. Such an
4632 -- entity requires special handling because it may be use-visible but
4633 -- hides directly visible entities defined outside the instance, because
4634 -- the corresponding formal did so in the generic.
4636 function Is_Actual_Parameter return Boolean;
4637 -- This function checks if the node N is an identifier that is an actual
4638 -- parameter of a procedure call. If so it returns True, otherwise it
4639 -- return False. The reason for this check is that at this stage we do
4640 -- not know what procedure is being called if the procedure might be
4641 -- overloaded, so it is premature to go setting referenced flags or
4642 -- making calls to Generate_Reference. We will wait till Resolve_Actuals
4643 -- for that processing
4645 function Known_But_Invisible (E : Entity_Id) return Boolean;
4646 -- This function determines whether a reference to the entity E, which
4647 -- is not visible, can reasonably be considered to be known to the
4648 -- writer of the reference. This is a heuristic test, used only for
4649 -- the purposes of figuring out whether we prefer to complain that an
4650 -- entity is undefined or invisible (and identify the declaration of
4651 -- the invisible entity in the latter case). The point here is that we
4652 -- don't want to complain that something is invisible and then point to
4653 -- something entirely mysterious to the writer.
4655 procedure Nvis_Messages;
4656 -- Called if there are no visible entries for N, but there is at least
4657 -- one non-directly visible, or hidden declaration. This procedure
4658 -- outputs an appropriate set of error messages.
4660 procedure Undefined (Nvis : Boolean);
4661 -- This function is called if the current node has no corresponding
4662 -- visible entity or entities. The value set in Msg indicates whether
4663 -- an error message was generated (multiple error messages for the
4664 -- same variable are generally suppressed, see body for details).
4665 -- Msg is True if an error message was generated, False if not. This
4666 -- value is used by the caller to determine whether or not to output
4667 -- additional messages where appropriate. The parameter is set False
4668 -- to get the message "X is undefined", and True to get the message
4669 -- "X is not visible".
4671 -------------------------
4672 -- From_Actual_Package --
4673 -------------------------
4675 function From_Actual_Package (E : Entity_Id) return Boolean is
4676 Scop : constant Entity_Id := Scope (E);
4677 -- Declared scope of candidate entity
4681 function Declared_In_Actual (Pack : Entity_Id) return Boolean;
4682 -- Recursive function that does the work and examines actuals of
4683 -- actual packages of current instance.
4685 ------------------------
4686 -- Declared_In_Actual --
4687 ------------------------
4689 function Declared_In_Actual (Pack : Entity_Id) return Boolean is
4693 if No (Associated_Formal_Package (Pack)) then
4697 Act := First_Entity (Pack);
4698 while Present (Act) loop
4699 if Renamed_Object (Pack) = Scop then
4702 -- Check for end of list of actuals.
4704 elsif Ekind (Act) = E_Package
4705 and then Renamed_Object (Act) = Pack
4709 elsif Ekind (Act) = E_Package
4710 and then Declared_In_Actual (Act)
4720 end Declared_In_Actual;
4722 -- Start of processing for From_Actual_Package
4725 if not In_Instance then
4729 Inst := Current_Scope;
4730 while Present (Inst)
4731 and then Ekind (Inst) /= E_Package
4732 and then not Is_Generic_Instance (Inst)
4734 Inst := Scope (Inst);
4741 Act := First_Entity (Inst);
4742 while Present (Act) loop
4743 if Ekind (Act) = E_Package
4744 and then Declared_In_Actual (Act)
4754 end From_Actual_Package;
4756 -------------------------
4757 -- Is_Actual_Parameter --
4758 -------------------------
4760 function Is_Actual_Parameter return Boolean is
4763 Nkind (N) = N_Identifier
4765 (Nkind (Parent (N)) = N_Procedure_Call_Statement
4767 (Nkind (Parent (N)) = N_Parameter_Association
4768 and then N = Explicit_Actual_Parameter (Parent (N))
4769 and then Nkind (Parent (Parent (N))) =
4770 N_Procedure_Call_Statement));
4771 end Is_Actual_Parameter;
4773 -------------------------
4774 -- Known_But_Invisible --
4775 -------------------------
4777 function Known_But_Invisible (E : Entity_Id) return Boolean is
4778 Fname : File_Name_Type;
4781 -- Entities in Standard are always considered to be known
4783 if Sloc (E) <= Standard_Location then
4786 -- An entity that does not come from source is always considered
4787 -- to be unknown, since it is an artifact of code expansion.
4789 elsif not Comes_From_Source (E) then
4792 -- In gnat internal mode, we consider all entities known. The
4793 -- historical reason behind this discrepancy is not known??? But the
4794 -- only effect is to modify the error message given, so it is not
4795 -- critical. Since it only affects the exact wording of error
4796 -- messages in illegal programs, we do not mention this as an
4797 -- effect of -gnatg, since it is not a language modification.
4799 elsif GNAT_Mode then
4803 -- Here we have an entity that is not from package Standard, and
4804 -- which comes from Source. See if it comes from an internal file.
4806 Fname := Unit_File_Name (Get_Source_Unit (E));
4808 -- Case of from internal file
4810 if Is_Internal_File_Name (Fname) then
4812 -- Private part entities in internal files are never considered
4813 -- to be known to the writer of normal application code.
4815 if Is_Hidden (E) then
4819 -- Entities from System packages other than System and
4820 -- System.Storage_Elements are not considered to be known.
4821 -- System.Auxxxx files are also considered known to the user.
4823 -- Should refine this at some point to generally distinguish
4824 -- between known and unknown internal files ???
4826 Get_Name_String (Fname);
4831 Name_Buffer (1 .. 2) /= "s-"
4833 Name_Buffer (3 .. 8) = "stoele"
4835 Name_Buffer (3 .. 5) = "aux";
4837 -- If not an internal file, then entity is definitely known,
4838 -- even if it is in a private part (the message generated will
4839 -- note that it is in a private part)
4844 end Known_But_Invisible;
4850 procedure Nvis_Messages is
4851 Comp_Unit : Node_Id;
4853 Found : Boolean := False;
4854 Hidden : Boolean := False;
4858 -- Ada 2005 (AI-262): Generate a precise error concerning the
4859 -- Beaujolais effect that was previously detected
4861 if Nvis_Is_Private_Subprg then
4863 pragma Assert (Nkind (E2) = N_Defining_Identifier
4864 and then Ekind (E2) = E_Function
4865 and then Scope (E2) = Standard_Standard
4866 and then Has_Private_With (E2));
4868 -- Find the sloc corresponding to the private with'ed unit
4870 Comp_Unit := Cunit (Current_Sem_Unit);
4871 Error_Msg_Sloc := No_Location;
4873 Item := First (Context_Items (Comp_Unit));
4874 while Present (Item) loop
4875 if Nkind (Item) = N_With_Clause
4876 and then Private_Present (Item)
4877 and then Entity (Name (Item)) = E2
4879 Error_Msg_Sloc := Sloc (Item);
4886 pragma Assert (Error_Msg_Sloc /= No_Location);
4888 Error_Msg_N ("(Ada 2005): hidden by private with clause #", N);
4892 Undefined (Nvis => True);
4896 -- First loop does hidden declarations
4899 while Present (Ent) loop
4900 if Is_Potentially_Use_Visible (Ent) then
4902 Error_Msg_N -- CODEFIX
4903 ("multiple use clauses cause hiding!", N);
4907 Error_Msg_Sloc := Sloc (Ent);
4908 Error_Msg_N -- CODEFIX
4909 ("hidden declaration#!", N);
4912 Ent := Homonym (Ent);
4915 -- If we found hidden declarations, then that's enough, don't
4916 -- bother looking for non-visible declarations as well.
4922 -- Second loop does non-directly visible declarations
4925 while Present (Ent) loop
4926 if not Is_Potentially_Use_Visible (Ent) then
4928 -- Do not bother the user with unknown entities
4930 if not Known_But_Invisible (Ent) then
4934 Error_Msg_Sloc := Sloc (Ent);
4936 -- Output message noting that there is a non-visible
4937 -- declaration, distinguishing the private part case.
4939 if Is_Hidden (Ent) then
4940 Error_Msg_N ("non-visible (private) declaration#!", N);
4942 -- If the entity is declared in a generic package, it
4943 -- cannot be visible, so there is no point in adding it
4944 -- to the list of candidates if another homograph from a
4945 -- non-generic package has been seen.
4947 elsif Ekind (Scope (Ent)) = E_Generic_Package
4953 Error_Msg_N -- CODEFIX
4954 ("non-visible declaration#!", N);
4956 if Ekind (Scope (Ent)) /= E_Generic_Package then
4960 if Is_Compilation_Unit (Ent)
4962 Nkind (Parent (Parent (N))) = N_Use_Package_Clause
4964 Error_Msg_Qual_Level := 99;
4965 Error_Msg_NE -- CODEFIX
4966 ("\\missing `WITH &;`", N, Ent);
4967 Error_Msg_Qual_Level := 0;
4970 if Ekind (Ent) = E_Discriminant
4971 and then Present (Corresponding_Discriminant (Ent))
4972 and then Scope (Corresponding_Discriminant (Ent)) =
4976 ("inherited discriminant not allowed here" &
4977 " (RM 3.8 (12), 3.8.1 (6))!", N);
4981 -- Set entity and its containing package as referenced. We
4982 -- can't be sure of this, but this seems a better choice
4983 -- to avoid unused entity messages.
4985 if Comes_From_Source (Ent) then
4986 Set_Referenced (Ent);
4987 Set_Referenced (Cunit_Entity (Get_Source_Unit (Ent)));
4992 Ent := Homonym (Ent);
5001 procedure Undefined (Nvis : Boolean) is
5002 Emsg : Error_Msg_Id;
5005 -- We should never find an undefined internal name. If we do, then
5006 -- see if we have previous errors. If so, ignore on the grounds that
5007 -- it is probably a cascaded message (e.g. a block label from a badly
5008 -- formed block). If no previous errors, then we have a real internal
5009 -- error of some kind so raise an exception.
5011 if Is_Internal_Name (Chars (N)) then
5012 if Total_Errors_Detected /= 0 then
5015 raise Program_Error;
5019 -- A very specialized error check, if the undefined variable is
5020 -- a case tag, and the case type is an enumeration type, check
5021 -- for a possible misspelling, and if so, modify the identifier
5023 -- Named aggregate should also be handled similarly ???
5025 if Nkind (N) = N_Identifier
5026 and then Nkind (Parent (N)) = N_Case_Statement_Alternative
5029 Case_Stm : constant Node_Id := Parent (Parent (N));
5030 Case_Typ : constant Entity_Id := Etype (Expression (Case_Stm));
5035 if Is_Enumeration_Type (Case_Typ)
5036 and then not Is_Standard_Character_Type (Case_Typ)
5038 Lit := First_Literal (Case_Typ);
5039 Get_Name_String (Chars (Lit));
5041 if Chars (Lit) /= Chars (N)
5042 and then Is_Bad_Spelling_Of (Chars (N), Chars (Lit))
5044 Error_Msg_Node_2 := Lit;
5045 Error_Msg_N -- CODEFIX
5046 ("& is undefined, assume misspelling of &", N);
5047 Rewrite (N, New_Occurrence_Of (Lit, Sloc (N)));
5051 Lit := Next_Literal (Lit);
5056 -- Normal processing
5058 Set_Entity (N, Any_Id);
5059 Set_Etype (N, Any_Type);
5061 -- We use the table Urefs to keep track of entities for which we
5062 -- have issued errors for undefined references. Multiple errors
5063 -- for a single name are normally suppressed, however we modify
5064 -- the error message to alert the programmer to this effect.
5066 for J in Urefs.First .. Urefs.Last loop
5067 if Chars (N) = Chars (Urefs.Table (J).Node) then
5068 if Urefs.Table (J).Err /= No_Error_Msg
5069 and then Sloc (N) /= Urefs.Table (J).Loc
5071 Error_Msg_Node_1 := Urefs.Table (J).Node;
5073 if Urefs.Table (J).Nvis then
5074 Change_Error_Text (Urefs.Table (J).Err,
5075 "& is not visible (more references follow)");
5077 Change_Error_Text (Urefs.Table (J).Err,
5078 "& is undefined (more references follow)");
5081 Urefs.Table (J).Err := No_Error_Msg;
5084 -- Although we will set Msg False, and thus suppress the
5085 -- message, we also set Error_Posted True, to avoid any
5086 -- cascaded messages resulting from the undefined reference.
5089 Set_Error_Posted (N, True);
5094 -- If entry not found, this is first undefined occurrence
5097 Error_Msg_N ("& is not visible!", N);
5101 Error_Msg_N ("& is undefined!", N);
5104 -- A very bizarre special check, if the undefined identifier
5105 -- is put or put_line, then add a special error message (since
5106 -- this is a very common error for beginners to make).
5108 if Nam_In (Chars (N), Name_Put, Name_Put_Line) then
5109 Error_Msg_N -- CODEFIX
5110 ("\\possible missing `WITH Ada.Text_'I'O; " &
5111 "USE Ada.Text_'I'O`!", N);
5113 -- Another special check if N is the prefix of a selected
5114 -- component which is a known unit, add message complaining
5115 -- about missing with for this unit.
5117 elsif Nkind (Parent (N)) = N_Selected_Component
5118 and then N = Prefix (Parent (N))
5119 and then Is_Known_Unit (Parent (N))
5121 Error_Msg_Node_2 := Selector_Name (Parent (N));
5122 Error_Msg_N -- CODEFIX
5123 ("\\missing `WITH &.&;`", Prefix (Parent (N)));
5126 -- Now check for possible misspellings
5130 Ematch : Entity_Id := Empty;
5132 Last_Name_Id : constant Name_Id :=
5133 Name_Id (Nat (First_Name_Id) +
5134 Name_Entries_Count - 1);
5137 for Nam in First_Name_Id .. Last_Name_Id loop
5138 E := Get_Name_Entity_Id (Nam);
5141 and then (Is_Immediately_Visible (E)
5143 Is_Potentially_Use_Visible (E))
5145 if Is_Bad_Spelling_Of (Chars (N), Nam) then
5152 if Present (Ematch) then
5153 Error_Msg_NE -- CODEFIX
5154 ("\possible misspelling of&", N, Ematch);
5159 -- Make entry in undefined references table unless the full errors
5160 -- switch is set, in which case by refraining from generating the
5161 -- table entry, we guarantee that we get an error message for every
5162 -- undefined reference.
5164 if not All_Errors_Mode then
5175 -- Start of processing for Find_Direct_Name
5178 -- If the entity pointer is already set, this is an internal node, or
5179 -- a node that is analyzed more than once, after a tree modification.
5180 -- In such a case there is no resolution to perform, just set the type.
5182 if Present (Entity (N)) then
5183 if Is_Type (Entity (N)) then
5184 Set_Etype (N, Entity (N));
5188 Entyp : constant Entity_Id := Etype (Entity (N));
5191 -- One special case here. If the Etype field is already set,
5192 -- and references the packed array type corresponding to the
5193 -- etype of the referenced entity, then leave it alone. This
5194 -- happens for trees generated from Exp_Pakd, where expressions
5195 -- can be deliberately "mis-typed" to the packed array type.
5197 if Is_Array_Type (Entyp)
5198 and then Is_Packed (Entyp)
5199 and then Present (Etype (N))
5200 and then Etype (N) = Packed_Array_Impl_Type (Entyp)
5204 -- If not that special case, then just reset the Etype
5207 Set_Etype (N, Etype (Entity (N)));
5215 -- Here if Entity pointer was not set, we need full visibility analysis
5216 -- First we generate debugging output if the debug E flag is set.
5218 if Debug_Flag_E then
5219 Write_Str ("Looking for ");
5220 Write_Name (Chars (N));
5224 Homonyms := Current_Entity (N);
5225 Nvis_Entity := False;
5228 while Present (E) loop
5230 -- If entity is immediately visible or potentially use visible, then
5231 -- process the entity and we are done.
5233 if Is_Immediately_Visible (E) then
5234 goto Immediately_Visible_Entity;
5236 elsif Is_Potentially_Use_Visible (E) then
5237 goto Potentially_Use_Visible_Entity;
5239 -- Note if a known but invisible entity encountered
5241 elsif Known_But_Invisible (E) then
5242 Nvis_Entity := True;
5245 -- Move to next entity in chain and continue search
5250 -- If no entries on homonym chain that were potentially visible,
5251 -- and no entities reasonably considered as non-visible, then
5252 -- we have a plain undefined reference, with no additional
5253 -- explanation required.
5255 if not Nvis_Entity then
5256 Undefined (Nvis => False);
5258 -- Otherwise there is at least one entry on the homonym chain that
5259 -- is reasonably considered as being known and non-visible.
5267 -- Processing for a potentially use visible entry found. We must search
5268 -- the rest of the homonym chain for two reasons. First, if there is a
5269 -- directly visible entry, then none of the potentially use-visible
5270 -- entities are directly visible (RM 8.4(10)). Second, we need to check
5271 -- for the case of multiple potentially use-visible entries hiding one
5272 -- another and as a result being non-directly visible (RM 8.4(11)).
5274 <<Potentially_Use_Visible_Entity>> declare
5275 Only_One_Visible : Boolean := True;
5276 All_Overloadable : Boolean := Is_Overloadable (E);
5280 while Present (E2) loop
5281 if Is_Immediately_Visible (E2) then
5283 -- If the use-visible entity comes from the actual for a
5284 -- formal package, it hides a directly visible entity from
5285 -- outside the instance.
5287 if From_Actual_Package (E)
5288 and then Scope_Depth (E2) < Scope_Depth (Inst)
5293 goto Immediately_Visible_Entity;
5296 elsif Is_Potentially_Use_Visible (E2) then
5297 Only_One_Visible := False;
5298 All_Overloadable := All_Overloadable and Is_Overloadable (E2);
5300 -- Ada 2005 (AI-262): Protect against a form of Beaujolais effect
5301 -- that can occur in private_with clauses. Example:
5304 -- private with B; package A is
5305 -- package C is function B return Integer;
5307 -- V1 : Integer := B;
5308 -- private function B return Integer;
5309 -- V2 : Integer := B;
5312 -- V1 resolves to A.B, but V2 resolves to library unit B
5314 elsif Ekind (E2) = E_Function
5315 and then Scope (E2) = Standard_Standard
5316 and then Has_Private_With (E2)
5318 Only_One_Visible := False;
5319 All_Overloadable := False;
5320 Nvis_Is_Private_Subprg := True;
5327 -- On falling through this loop, we have checked that there are no
5328 -- immediately visible entities. Only_One_Visible is set if exactly
5329 -- one potentially use visible entity exists. All_Overloadable is
5330 -- set if all the potentially use visible entities are overloadable.
5331 -- The condition for legality is that either there is one potentially
5332 -- use visible entity, or if there is more than one, then all of them
5333 -- are overloadable.
5335 if Only_One_Visible or All_Overloadable then
5338 -- If there is more than one potentially use-visible entity and at
5339 -- least one of them non-overloadable, we have an error (RM 8.4(11)).
5340 -- Note that E points to the first such entity on the homonym list.
5341 -- Special case: if one of the entities is declared in an actual
5342 -- package, it was visible in the generic, and takes precedence over
5343 -- other entities that are potentially use-visible. Same if it is
5344 -- declared in a local instantiation of the current instance.
5349 -- Find current instance
5351 Inst := Current_Scope;
5352 while Present (Inst) and then Inst /= Standard_Standard loop
5353 if Is_Generic_Instance (Inst) then
5357 Inst := Scope (Inst);
5361 while Present (E2) loop
5362 if From_Actual_Package (E2)
5364 (Is_Generic_Instance (Scope (E2))
5365 and then Scope_Depth (Scope (E2)) > Scope_Depth (Inst))
5378 Is_Predefined_File_Name (Unit_File_Name (Current_Sem_Unit))
5380 -- A use-clause in the body of a system file creates conflict
5381 -- with some entity in a user scope, while rtsfind is active.
5382 -- Keep only the entity coming from another predefined unit.
5385 while Present (E2) loop
5386 if Is_Predefined_File_Name
5387 (Unit_File_Name (Get_Source_Unit (Sloc (E2))))
5396 -- Entity must exist because predefined unit is correct
5398 raise Program_Error;
5407 -- Come here with E set to the first immediately visible entity on
5408 -- the homonym chain. This is the one we want unless there is another
5409 -- immediately visible entity further on in the chain for an inner
5410 -- scope (RM 8.3(8)).
5412 <<Immediately_Visible_Entity>> declare
5417 -- Find scope level of initial entity. When compiling through
5418 -- Rtsfind, the previous context is not completely invisible, and
5419 -- an outer entity may appear on the chain, whose scope is below
5420 -- the entry for Standard that delimits the current scope stack.
5421 -- Indicate that the level for this spurious entry is outside of
5422 -- the current scope stack.
5424 Level := Scope_Stack.Last;
5426 Scop := Scope_Stack.Table (Level).Entity;
5427 exit when Scop = Scope (E);
5429 exit when Scop = Standard_Standard;
5432 -- Now search remainder of homonym chain for more inner entry
5433 -- If the entity is Standard itself, it has no scope, and we
5434 -- compare it with the stack entry directly.
5437 while Present (E2) loop
5438 if Is_Immediately_Visible (E2) then
5440 -- If a generic package contains a local declaration that
5441 -- has the same name as the generic, there may be a visibility
5442 -- conflict in an instance, where the local declaration must
5443 -- also hide the name of the corresponding package renaming.
5444 -- We check explicitly for a package declared by a renaming,
5445 -- whose renamed entity is an instance that is on the scope
5446 -- stack, and that contains a homonym in the same scope. Once
5447 -- we have found it, we know that the package renaming is not
5448 -- immediately visible, and that the identifier denotes the
5449 -- other entity (and its homonyms if overloaded).
5451 if Scope (E) = Scope (E2)
5452 and then Ekind (E) = E_Package
5453 and then Present (Renamed_Object (E))
5454 and then Is_Generic_Instance (Renamed_Object (E))
5455 and then In_Open_Scopes (Renamed_Object (E))
5456 and then Comes_From_Source (N)
5458 Set_Is_Immediately_Visible (E, False);
5462 for J in Level + 1 .. Scope_Stack.Last loop
5463 if Scope_Stack.Table (J).Entity = Scope (E2)
5464 or else Scope_Stack.Table (J).Entity = E2
5477 -- At the end of that loop, E is the innermost immediately
5478 -- visible entity, so we are all set.
5481 -- Come here with entity found, and stored in E
5485 -- Check violation of No_Wide_Characters restriction
5487 Check_Wide_Character_Restriction (E, N);
5489 -- When distribution features are available (Get_PCS_Name /=
5490 -- Name_No_DSA), a remote access-to-subprogram type is converted
5491 -- into a record type holding whatever information is needed to
5492 -- perform a remote call on an RCI subprogram. In that case we
5493 -- rewrite any occurrence of the RAS type into the equivalent record
5494 -- type here. 'Access attribute references and RAS dereferences are
5495 -- then implemented using specific TSSs. However when distribution is
5496 -- not available (case of Get_PCS_Name = Name_No_DSA), we bypass the
5497 -- generation of these TSSs, and we must keep the RAS type in its
5498 -- original access-to-subprogram form (since all calls through a
5499 -- value of such type will be local anyway in the absence of a PCS).
5501 if Comes_From_Source (N)
5502 and then Is_Remote_Access_To_Subprogram_Type (E)
5503 and then Ekind (E) = E_Access_Subprogram_Type
5504 and then Expander_Active
5505 and then Get_PCS_Name /= Name_No_DSA
5507 Rewrite (N, New_Occurrence_Of (Equivalent_Type (E), Sloc (N)));
5511 -- Set the entity. Note that the reason we call Set_Entity for the
5512 -- overloadable case, as opposed to Set_Entity_With_Checks is
5513 -- that in the overloaded case, the initial call can set the wrong
5514 -- homonym. The call that sets the right homonym is in Sem_Res and
5515 -- that call does use Set_Entity_With_Checks, so we don't miss
5518 if Is_Overloadable (E) then
5521 Set_Entity_With_Checks (N, E);
5527 Set_Etype (N, Get_Full_View (Etype (E)));
5530 if Debug_Flag_E then
5531 Write_Str (" found ");
5532 Write_Entity_Info (E, " ");
5535 -- If the Ekind of the entity is Void, it means that all homonyms
5536 -- are hidden from all visibility (RM 8.3(5,14-20)). However, this
5537 -- test is skipped if the current scope is a record and the name is
5538 -- a pragma argument expression (case of Atomic and Volatile pragmas
5539 -- and possibly other similar pragmas added later, which are allowed
5540 -- to reference components in the current record).
5542 if Ekind (E) = E_Void
5544 (not Is_Record_Type (Current_Scope)
5545 or else Nkind (Parent (N)) /= N_Pragma_Argument_Association)
5547 Premature_Usage (N);
5549 -- If the entity is overloadable, collect all interpretations of the
5550 -- name for subsequent overload resolution. We optimize a bit here to
5551 -- do this only if we have an overloadable entity that is not on its
5552 -- own on the homonym chain.
5554 elsif Is_Overloadable (E)
5555 and then (Present (Homonym (E)) or else Current_Entity (N) /= E)
5557 Collect_Interps (N);
5559 -- If no homonyms were visible, the entity is unambiguous
5561 if not Is_Overloaded (N) then
5562 if not Is_Actual_Parameter then
5563 Generate_Reference (E, N);
5567 -- Case of non-overloadable entity, set the entity providing that
5568 -- we do not have the case of a discriminant reference within a
5569 -- default expression. Such references are replaced with the
5570 -- corresponding discriminal, which is the formal corresponding to
5571 -- to the discriminant in the initialization procedure.
5574 -- Entity is unambiguous, indicate that it is referenced here
5576 -- For a renaming of an object, always generate simple reference,
5577 -- we don't try to keep track of assignments in this case, except
5578 -- in SPARK mode where renamings are traversed for generating
5579 -- local effects of subprograms.
5582 and then Present (Renamed_Object (E))
5583 and then not GNATprove_Mode
5585 Generate_Reference (E, N);
5587 -- If the renamed entity is a private protected component,
5588 -- reference the original component as well. This needs to be
5589 -- done because the private renamings are installed before any
5590 -- analysis has occurred. Reference to a private component will
5591 -- resolve to the renaming and the original component will be
5592 -- left unreferenced, hence the following.
5594 if Is_Prival (E) then
5595 Generate_Reference (Prival_Link (E), N);
5598 -- One odd case is that we do not want to set the Referenced flag
5599 -- if the entity is a label, and the identifier is the label in
5600 -- the source, since this is not a reference from the point of
5601 -- view of the user.
5603 elsif Nkind (Parent (N)) = N_Label then
5605 R : constant Boolean := Referenced (E);
5608 -- Generate reference unless this is an actual parameter
5609 -- (see comment below)
5611 if Is_Actual_Parameter then
5612 Generate_Reference (E, N);
5613 Set_Referenced (E, R);
5617 -- Normal case, not a label: generate reference
5620 if not Is_Actual_Parameter then
5622 -- Package or generic package is always a simple reference
5624 if Ekind_In (E, E_Package, E_Generic_Package) then
5625 Generate_Reference (E, N, 'r');
5627 -- Else see if we have a left hand side
5632 Generate_Reference (E, N, 'm');
5635 Generate_Reference (E, N, 'r');
5637 -- If we don't know now, generate reference later
5640 Deferred_References.Append ((E, N));
5645 Check_Nested_Access (E);
5648 Set_Entity_Or_Discriminal (N, E);
5650 -- The name may designate a generalized reference, in which case
5651 -- the dereference interpretation will be included.
5653 if Ada_Version >= Ada_2012
5655 (Nkind (Parent (N)) in N_Subexpr
5656 or else Nkind_In (Parent (N), N_Object_Declaration,
5657 N_Assignment_Statement))
5659 Check_Implicit_Dereference (N, Etype (E));
5664 -- Come here with entity set
5667 Check_Restriction_No_Use_Of_Entity (N);
5668 end Find_Direct_Name;
5670 ------------------------
5671 -- Find_Expanded_Name --
5672 ------------------------
5674 -- This routine searches the homonym chain of the entity until it finds
5675 -- an entity declared in the scope denoted by the prefix. If the entity
5676 -- is private, it may nevertheless be immediately visible, if we are in
5677 -- the scope of its declaration.
5679 procedure Find_Expanded_Name (N : Node_Id) is
5680 function In_Pragmas_Depends_Or_Global (N : Node_Id) return Boolean;
5681 -- Determine whether an arbitrary node N appears in pragmas [Refined_]
5682 -- Depends or [Refined_]Global.
5684 ----------------------------------
5685 -- In_Pragmas_Depends_Or_Global --
5686 ----------------------------------
5688 function In_Pragmas_Depends_Or_Global (N : Node_Id) return Boolean is
5692 -- Climb the parent chain looking for a pragma
5695 while Present (Par) loop
5696 if Nkind (Par) = N_Pragma
5697 and then Nam_In (Pragma_Name (Par), Name_Depends,
5699 Name_Refined_Depends,
5700 Name_Refined_Global)
5704 -- Prevent the search from going too far
5706 elsif Is_Body_Or_Package_Declaration (Par) then
5710 Par := Parent (Par);
5714 end In_Pragmas_Depends_Or_Global;
5718 Selector : constant Node_Id := Selector_Name (N);
5719 Candidate : Entity_Id := Empty;
5723 -- Start of processing for Find_Expanded_Name
5726 P_Name := Entity (Prefix (N));
5728 -- If the prefix is a renamed package, look for the entity in the
5729 -- original package.
5731 if Ekind (P_Name) = E_Package
5732 and then Present (Renamed_Object (P_Name))
5734 P_Name := Renamed_Object (P_Name);
5736 -- Rewrite node with entity field pointing to renamed object
5738 Rewrite (Prefix (N), New_Copy (Prefix (N)));
5739 Set_Entity (Prefix (N), P_Name);
5741 -- If the prefix is an object of a concurrent type, look for
5742 -- the entity in the associated task or protected type.
5744 elsif Is_Concurrent_Type (Etype (P_Name)) then
5745 P_Name := Etype (P_Name);
5748 Id := Current_Entity (Selector);
5751 Is_New_Candidate : Boolean;
5754 while Present (Id) loop
5755 if Scope (Id) = P_Name then
5757 Is_New_Candidate := True;
5759 -- Handle abstract views of states and variables. These are
5760 -- acceptable only when the reference to the view appears in
5761 -- pragmas [Refined_]Depends and [Refined_]Global.
5763 if Ekind (Id) = E_Abstract_State
5764 and then From_Limited_With (Id)
5765 and then Present (Non_Limited_View (Id))
5767 if In_Pragmas_Depends_Or_Global (N) then
5768 Candidate := Non_Limited_View (Id);
5769 Is_New_Candidate := True;
5771 -- Hide candidate because it is not used in a proper context
5775 Is_New_Candidate := False;
5779 -- Ada 2005 (AI-217): Handle shadow entities associated with
5780 -- types declared in limited-withed nested packages. We don't need
5781 -- to handle E_Incomplete_Subtype entities because the entities
5782 -- in the limited view are always E_Incomplete_Type and
5783 -- E_Class_Wide_Type entities (see Build_Limited_Views).
5785 -- Regarding the expression used to evaluate the scope, it
5786 -- is important to note that the limited view also has shadow
5787 -- entities associated nested packages. For this reason the
5788 -- correct scope of the entity is the scope of the real entity.
5789 -- The non-limited view may itself be incomplete, in which case
5790 -- get the full view if available.
5792 elsif Ekind_In (Id, E_Incomplete_Type, E_Class_Wide_Type)
5793 and then From_Limited_With (Id)
5794 and then Present (Non_Limited_View (Id))
5795 and then Scope (Non_Limited_View (Id)) = P_Name
5797 Candidate := Get_Full_View (Non_Limited_View (Id));
5798 Is_New_Candidate := True;
5801 Is_New_Candidate := False;
5804 if Is_New_Candidate then
5806 -- If entity is a child unit, either it is a visible child of
5807 -- the prefix, or we are in the body of a generic prefix, as
5808 -- will happen when a child unit is instantiated in the body
5809 -- of a generic parent. This is because the instance body does
5810 -- not restore the full compilation context, given that all
5811 -- non-local references have been captured.
5813 if Is_Child_Unit (Id) or else P_Name = Standard_Standard then
5814 exit when Is_Visible_Lib_Unit (Id)
5815 or else (Is_Child_Unit (Id)
5816 and then In_Open_Scopes (Scope (Id))
5817 and then In_Instance_Body);
5819 exit when not Is_Hidden (Id);
5822 exit when Is_Immediately_Visible (Id);
5830 and then Ekind_In (P_Name, E_Procedure, E_Function)
5831 and then Is_Generic_Instance (P_Name)
5833 -- Expanded name denotes entity in (instance of) generic subprogram.
5834 -- The entity may be in the subprogram instance, or may denote one of
5835 -- the formals, which is declared in the enclosing wrapper package.
5837 P_Name := Scope (P_Name);
5839 Id := Current_Entity (Selector);
5840 while Present (Id) loop
5841 exit when Scope (Id) = P_Name;
5846 if No (Id) or else Chars (Id) /= Chars (Selector) then
5847 Set_Etype (N, Any_Type);
5849 -- If we are looking for an entity defined in System, try to find it
5850 -- in the child package that may have been provided as an extension
5851 -- to System. The Extend_System pragma will have supplied the name of
5852 -- the extension, which may have to be loaded.
5854 if Chars (P_Name) = Name_System
5855 and then Scope (P_Name) = Standard_Standard
5856 and then Present (System_Extend_Unit)
5857 and then Present_System_Aux (N)
5859 Set_Entity (Prefix (N), System_Aux_Id);
5860 Find_Expanded_Name (N);
5863 elsif Nkind (Selector) = N_Operator_Symbol
5864 and then Has_Implicit_Operator (N)
5866 -- There is an implicit instance of the predefined operator in
5867 -- the given scope. The operator entity is defined in Standard.
5868 -- Has_Implicit_Operator makes the node into an Expanded_Name.
5872 elsif Nkind (Selector) = N_Character_Literal
5873 and then Has_Implicit_Character_Literal (N)
5875 -- If there is no literal defined in the scope denoted by the
5876 -- prefix, the literal may belong to (a type derived from)
5877 -- Standard_Character, for which we have no explicit literals.
5882 -- If the prefix is a single concurrent object, use its name in
5883 -- the error message, rather than that of the anonymous type.
5885 if Is_Concurrent_Type (P_Name)
5886 and then Is_Internal_Name (Chars (P_Name))
5888 Error_Msg_Node_2 := Entity (Prefix (N));
5890 Error_Msg_Node_2 := P_Name;
5893 if P_Name = System_Aux_Id then
5894 P_Name := Scope (P_Name);
5895 Set_Entity (Prefix (N), P_Name);
5898 if Present (Candidate) then
5900 -- If we know that the unit is a child unit we can give a more
5901 -- accurate error message.
5903 if Is_Child_Unit (Candidate) then
5905 -- If the candidate is a private child unit and we are in
5906 -- the visible part of a public unit, specialize the error
5907 -- message. There might be a private with_clause for it,
5908 -- but it is not currently active.
5910 if Is_Private_Descendant (Candidate)
5911 and then Ekind (Current_Scope) = E_Package
5912 and then not In_Private_Part (Current_Scope)
5913 and then not Is_Private_Descendant (Current_Scope)
5915 Error_Msg_N ("private child unit& is not visible here",
5918 -- Normal case where we have a missing with for a child unit
5921 Error_Msg_Qual_Level := 99;
5922 Error_Msg_NE -- CODEFIX
5923 ("missing `WITH &;`", Selector, Candidate);
5924 Error_Msg_Qual_Level := 0;
5927 -- Here we don't know that this is a child unit
5930 Error_Msg_NE ("& is not a visible entity of&", N, Selector);
5934 -- Within the instantiation of a child unit, the prefix may
5935 -- denote the parent instance, but the selector has the name
5936 -- of the original child. That is to say, when A.B appears
5937 -- within an instantiation of generic child unit B, the scope
5938 -- stack includes an instance of A (P_Name) and an instance
5939 -- of B under some other name. We scan the scope to find this
5940 -- child instance, which is the desired entity.
5941 -- Note that the parent may itself be a child instance, if
5942 -- the reference is of the form A.B.C, in which case A.B has
5943 -- already been rewritten with the proper entity.
5945 if In_Open_Scopes (P_Name)
5946 and then Is_Generic_Instance (P_Name)
5949 Gen_Par : constant Entity_Id :=
5950 Generic_Parent (Specification
5951 (Unit_Declaration_Node (P_Name)));
5952 S : Entity_Id := Current_Scope;
5956 for J in reverse 0 .. Scope_Stack.Last loop
5957 S := Scope_Stack.Table (J).Entity;
5959 exit when S = Standard_Standard;
5961 if Ekind_In (S, E_Function,
5965 P := Generic_Parent (Specification
5966 (Unit_Declaration_Node (S)));
5968 -- Check that P is a generic child of the generic
5969 -- parent of the prefix.
5972 and then Chars (P) = Chars (Selector)
5973 and then Scope (P) = Gen_Par
5984 -- If this is a selection from Ada, System or Interfaces, then
5985 -- we assume a missing with for the corresponding package.
5987 if Is_Known_Unit (N) then
5988 if not Error_Posted (N) then
5989 Error_Msg_Node_2 := Selector;
5990 Error_Msg_N -- CODEFIX
5991 ("missing `WITH &.&;`", Prefix (N));
5994 -- If this is a selection from a dummy package, then suppress
5995 -- the error message, of course the entity is missing if the
5996 -- package is missing.
5998 elsif Sloc (Error_Msg_Node_2) = No_Location then
6001 -- Here we have the case of an undefined component
6005 -- The prefix may hide a homonym in the context that
6006 -- declares the desired entity. This error can use a
6007 -- specialized message.
6009 if In_Open_Scopes (P_Name) then
6011 H : constant Entity_Id := Homonym (P_Name);
6015 and then Is_Compilation_Unit (H)
6017 (Is_Immediately_Visible (H)
6018 or else Is_Visible_Lib_Unit (H))
6020 Id := First_Entity (H);
6021 while Present (Id) loop
6022 if Chars (Id) = Chars (Selector) then
6023 Error_Msg_Qual_Level := 99;
6024 Error_Msg_Name_1 := Chars (Selector);
6026 ("% not declared in&", N, P_Name);
6028 ("\use fully qualified name starting with "
6029 & "Standard to make& visible", N, H);
6030 Error_Msg_Qual_Level := 0;
6038 -- If not found, standard error message
6040 Error_Msg_NE ("& not declared in&", N, Selector);
6046 Error_Msg_NE ("& not declared in&", N, Selector);
6049 -- Check for misspelling of some entity in prefix
6051 Id := First_Entity (P_Name);
6052 while Present (Id) loop
6053 if Is_Bad_Spelling_Of (Chars (Id), Chars (Selector))
6054 and then not Is_Internal_Name (Chars (Id))
6056 Error_Msg_NE -- CODEFIX
6057 ("possible misspelling of&", Selector, Id);
6064 -- Specialize the message if this may be an instantiation
6065 -- of a child unit that was not mentioned in the context.
6067 if Nkind (Parent (N)) = N_Package_Instantiation
6068 and then Is_Generic_Instance (Entity (Prefix (N)))
6069 and then Is_Compilation_Unit
6070 (Generic_Parent (Parent (Entity (Prefix (N)))))
6072 Error_Msg_Node_2 := Selector;
6073 Error_Msg_N -- CODEFIX
6074 ("\missing `WITH &.&;`", Prefix (N));
6084 if Comes_From_Source (N)
6085 and then Is_Remote_Access_To_Subprogram_Type (Id)
6086 and then Ekind (Id) = E_Access_Subprogram_Type
6087 and then Present (Equivalent_Type (Id))
6089 -- If we are not actually generating distribution code (i.e. the
6090 -- current PCS is the dummy non-distributed version), then the
6091 -- Equivalent_Type will be missing, and Id should be treated as
6092 -- a regular access-to-subprogram type.
6094 Id := Equivalent_Type (Id);
6095 Set_Chars (Selector, Chars (Id));
6098 -- Ada 2005 (AI-50217): Check usage of entities in limited withed units
6100 if Ekind (P_Name) = E_Package and then From_Limited_With (P_Name) then
6101 if From_Limited_With (Id)
6102 or else Is_Type (Id)
6103 or else Ekind (Id) = E_Package
6108 ("limited withed package can only be used to access "
6109 & "incomplete types", N);
6113 if Is_Task_Type (P_Name)
6114 and then ((Ekind (Id) = E_Entry
6115 and then Nkind (Parent (N)) /= N_Attribute_Reference)
6117 (Ekind (Id) = E_Entry_Family
6119 Nkind (Parent (Parent (N))) /= N_Attribute_Reference))
6121 -- If both the task type and the entry are in scope, this may still
6122 -- be the expanded name of an entry formal.
6124 if In_Open_Scopes (Id)
6125 and then Nkind (Parent (N)) = N_Selected_Component
6130 -- It is an entry call after all, either to the current task
6131 -- (which will deadlock) or to an enclosing task.
6133 Analyze_Selected_Component (N);
6138 Change_Selected_Component_To_Expanded_Name (N);
6140 -- Set appropriate type
6142 if Is_Type (Id) then
6145 Set_Etype (N, Get_Full_View (Etype (Id)));
6148 -- Do style check and generate reference, but skip both steps if this
6149 -- entity has homonyms, since we may not have the right homonym set yet.
6150 -- The proper homonym will be set during the resolve phase.
6152 if Has_Homonym (Id) then
6156 Set_Entity_Or_Discriminal (N, Id);
6160 Generate_Reference (Id, N, 'm');
6162 Generate_Reference (Id, N, 'r');
6164 Deferred_References.Append ((Id, N));
6168 -- Check for violation of No_Wide_Characters
6170 Check_Wide_Character_Restriction (Id, N);
6172 -- If the Ekind of the entity is Void, it means that all homonyms are
6173 -- hidden from all visibility (RM 8.3(5,14-20)).
6175 if Ekind (Id) = E_Void then
6176 Premature_Usage (N);
6178 elsif Is_Overloadable (Id) and then Present (Homonym (Id)) then
6180 H : Entity_Id := Homonym (Id);
6183 while Present (H) loop
6184 if Scope (H) = Scope (Id)
6185 and then (not Is_Hidden (H)
6186 or else Is_Immediately_Visible (H))
6188 Collect_Interps (N);
6195 -- If an extension of System is present, collect possible explicit
6196 -- overloadings declared in the extension.
6198 if Chars (P_Name) = Name_System
6199 and then Scope (P_Name) = Standard_Standard
6200 and then Present (System_Extend_Unit)
6201 and then Present_System_Aux (N)
6203 H := Current_Entity (Id);
6205 while Present (H) loop
6206 if Scope (H) = System_Aux_Id then
6207 Add_One_Interp (N, H, Etype (H));
6216 if Nkind (Selector_Name (N)) = N_Operator_Symbol
6217 and then Scope (Id) /= Standard_Standard
6219 -- In addition to user-defined operators in the given scope, there
6220 -- may be an implicit instance of the predefined operator. The
6221 -- operator (defined in Standard) is found in Has_Implicit_Operator,
6222 -- and added to the interpretations. Procedure Add_One_Interp will
6223 -- determine which hides which.
6225 if Has_Implicit_Operator (N) then
6230 -- If there is a single interpretation for N we can generate a
6231 -- reference to the unique entity found.
6233 if Is_Overloadable (Id) and then not Is_Overloaded (N) then
6234 Generate_Reference (Id, N);
6236 end Find_Expanded_Name;
6238 -------------------------
6239 -- Find_Renamed_Entity --
6240 -------------------------
6242 function Find_Renamed_Entity
6246 Is_Actual : Boolean := False) return Entity_Id
6249 I1 : Interp_Index := 0; -- Suppress junk warnings
6255 function Is_Visible_Operation (Op : Entity_Id) return Boolean;
6256 -- If the renamed entity is an implicit operator, check whether it is
6257 -- visible because its operand type is properly visible. This check
6258 -- applies to explicit renamed entities that appear in the source in a
6259 -- renaming declaration or a formal subprogram instance, but not to
6260 -- default generic actuals with a name.
6262 function Report_Overload return Entity_Id;
6263 -- List possible interpretations, and specialize message in the
6264 -- case of a generic actual.
6266 function Within (Inner, Outer : Entity_Id) return Boolean;
6267 -- Determine whether a candidate subprogram is defined within the
6268 -- enclosing instance. If yes, it has precedence over outer candidates.
6270 --------------------------
6271 -- Is_Visible_Operation --
6272 --------------------------
6274 function Is_Visible_Operation (Op : Entity_Id) return Boolean is
6280 if Ekind (Op) /= E_Operator
6281 or else Scope (Op) /= Standard_Standard
6282 or else (In_Instance
6283 and then (not Is_Actual
6284 or else Present (Enclosing_Instance)))
6289 -- For a fixed point type operator, check the resulting type,
6290 -- because it may be a mixed mode integer * fixed operation.
6292 if Present (Next_Formal (First_Formal (New_S)))
6293 and then Is_Fixed_Point_Type (Etype (New_S))
6295 Typ := Etype (New_S);
6297 Typ := Etype (First_Formal (New_S));
6300 Btyp := Base_Type (Typ);
6302 if Nkind (Nam) /= N_Expanded_Name then
6303 return (In_Open_Scopes (Scope (Btyp))
6304 or else Is_Potentially_Use_Visible (Btyp)
6305 or else In_Use (Btyp)
6306 or else In_Use (Scope (Btyp)));
6309 Scop := Entity (Prefix (Nam));
6311 if Ekind (Scop) = E_Package
6312 and then Present (Renamed_Object (Scop))
6314 Scop := Renamed_Object (Scop);
6317 -- Operator is visible if prefix of expanded name denotes
6318 -- scope of type, or else type is defined in System_Aux
6319 -- and the prefix denotes System.
6321 return Scope (Btyp) = Scop
6322 or else (Scope (Btyp) = System_Aux_Id
6323 and then Scope (Scope (Btyp)) = Scop);
6326 end Is_Visible_Operation;
6332 function Within (Inner, Outer : Entity_Id) return Boolean is
6336 Sc := Scope (Inner);
6337 while Sc /= Standard_Standard loop
6348 ---------------------
6349 -- Report_Overload --
6350 ---------------------
6352 function Report_Overload return Entity_Id is
6355 Error_Msg_NE -- CODEFIX
6356 ("ambiguous actual subprogram&, " &
6357 "possible interpretations:", N, Nam);
6359 Error_Msg_N -- CODEFIX
6360 ("ambiguous subprogram, " &
6361 "possible interpretations:", N);
6364 List_Interps (Nam, N);
6366 end Report_Overload;
6368 -- Start of processing for Find_Renamed_Entity
6372 Candidate_Renaming := Empty;
6374 if Is_Overloaded (Nam) then
6375 Get_First_Interp (Nam, Ind, It);
6376 while Present (It.Nam) loop
6377 if Entity_Matches_Spec (It.Nam, New_S)
6378 and then Is_Visible_Operation (It.Nam)
6380 if Old_S /= Any_Id then
6382 -- Note: The call to Disambiguate only happens if a
6383 -- previous interpretation was found, in which case I1
6384 -- has received a value.
6386 It1 := Disambiguate (Nam, I1, Ind, Etype (Old_S));
6388 if It1 = No_Interp then
6389 Inst := Enclosing_Instance;
6391 if Present (Inst) then
6392 if Within (It.Nam, Inst) then
6393 if Within (Old_S, Inst) then
6395 -- Choose the innermost subprogram, which would
6396 -- have hidden the outer one in the generic.
6398 if Scope_Depth (It.Nam) <
6407 elsif Within (Old_S, Inst) then
6411 return Report_Overload;
6414 -- If not within an instance, ambiguity is real
6417 return Report_Overload;
6431 Present (First_Formal (It.Nam))
6432 and then Present (First_Formal (New_S))
6433 and then (Base_Type (Etype (First_Formal (It.Nam))) =
6434 Base_Type (Etype (First_Formal (New_S))))
6436 Candidate_Renaming := It.Nam;
6439 Get_Next_Interp (Ind, It);
6442 Set_Entity (Nam, Old_S);
6444 if Old_S /= Any_Id then
6445 Set_Is_Overloaded (Nam, False);
6448 -- Non-overloaded case
6451 if Is_Actual and then Present (Enclosing_Instance) then
6452 Old_S := Entity (Nam);
6454 elsif Entity_Matches_Spec (Entity (Nam), New_S) then
6455 Candidate_Renaming := New_S;
6457 if Is_Visible_Operation (Entity (Nam)) then
6458 Old_S := Entity (Nam);
6461 elsif Present (First_Formal (Entity (Nam)))
6462 and then Present (First_Formal (New_S))
6463 and then (Base_Type (Etype (First_Formal (Entity (Nam)))) =
6464 Base_Type (Etype (First_Formal (New_S))))
6466 Candidate_Renaming := Entity (Nam);
6471 end Find_Renamed_Entity;
6473 -----------------------------
6474 -- Find_Selected_Component --
6475 -----------------------------
6477 procedure Find_Selected_Component (N : Node_Id) is
6478 P : constant Node_Id := Prefix (N);
6481 -- Entity denoted by prefix
6488 function Available_Subtype return Boolean;
6489 -- A small optimization: if the prefix is constrained and the component
6490 -- is an array type we may already have a usable subtype for it, so we
6491 -- can use it rather than generating a new one, because the bounds
6492 -- will be the values of the discriminants and not discriminant refs.
6493 -- This simplifies value tracing in GNATProve. For consistency, both
6494 -- the entity name and the subtype come from the constrained component.
6496 function Is_Reference_In_Subunit return Boolean;
6497 -- In a subunit, the scope depth is not a proper measure of hiding,
6498 -- because the context of the proper body may itself hide entities in
6499 -- parent units. This rare case requires inspecting the tree directly
6500 -- because the proper body is inserted in the main unit and its context
6501 -- is simply added to that of the parent.
6503 -----------------------
6504 -- Available_Subtype --
6505 -----------------------
6507 function Available_Subtype return Boolean is
6511 Comp := First_Entity (Etype (P));
6512 while Present (Comp) loop
6513 if Chars (Comp) = Chars (Selector_Name (N)) then
6514 Set_Etype (N, Etype (Comp));
6515 Set_Entity (Selector_Name (N), Comp);
6516 Set_Etype (Selector_Name (N), Etype (Comp));
6520 Next_Component (Comp);
6524 end Available_Subtype;
6526 -----------------------------
6527 -- Is_Reference_In_Subunit --
6528 -----------------------------
6530 function Is_Reference_In_Subunit return Boolean is
6532 Comp_Unit : Node_Id;
6536 while Present (Comp_Unit)
6537 and then Nkind (Comp_Unit) /= N_Compilation_Unit
6539 Comp_Unit := Parent (Comp_Unit);
6542 if No (Comp_Unit) or else Nkind (Unit (Comp_Unit)) /= N_Subunit then
6546 -- Now check whether the package is in the context of the subunit
6548 Clause := First (Context_Items (Comp_Unit));
6549 while Present (Clause) loop
6550 if Nkind (Clause) = N_With_Clause
6551 and then Entity (Name (Clause)) = P_Name
6556 Clause := Next (Clause);
6560 end Is_Reference_In_Subunit;
6562 -- Start of processing for Find_Selected_Component
6567 if Nkind (P) = N_Error then
6571 -- Selector name cannot be a character literal or an operator symbol in
6572 -- SPARK, except for the operator symbol in a renaming.
6574 if Restriction_Check_Required (SPARK_05) then
6575 if Nkind (Selector_Name (N)) = N_Character_Literal then
6576 Check_SPARK_05_Restriction
6577 ("character literal cannot be prefixed", N);
6578 elsif Nkind (Selector_Name (N)) = N_Operator_Symbol
6579 and then Nkind (Parent (N)) /= N_Subprogram_Renaming_Declaration
6581 Check_SPARK_05_Restriction
6582 ("operator symbol cannot be prefixed", N);
6586 -- If the selector already has an entity, the node has been constructed
6587 -- in the course of expansion, and is known to be valid. Do not verify
6588 -- that it is defined for the type (it may be a private component used
6589 -- in the expansion of record equality).
6591 if Present (Entity (Selector_Name (N))) then
6592 if No (Etype (N)) or else Etype (N) = Any_Type then
6594 Sel_Name : constant Node_Id := Selector_Name (N);
6595 Selector : constant Entity_Id := Entity (Sel_Name);
6599 Set_Etype (Sel_Name, Etype (Selector));
6601 if not Is_Entity_Name (P) then
6605 -- Build an actual subtype except for the first parameter
6606 -- of an init proc, where this actual subtype is by
6607 -- definition incorrect, since the object is uninitialized
6608 -- (and does not even have defined discriminants etc.)
6610 if Is_Entity_Name (P)
6611 and then Ekind (Entity (P)) = E_Function
6613 Nam := New_Copy (P);
6615 if Is_Overloaded (P) then
6616 Save_Interps (P, Nam);
6619 Rewrite (P, Make_Function_Call (Sloc (P), Name => Nam));
6621 Analyze_Selected_Component (N);
6624 elsif Ekind (Selector) = E_Component
6625 and then (not Is_Entity_Name (P)
6626 or else Chars (Entity (P)) /= Name_uInit)
6628 -- Check if we already have an available subtype we can use
6630 if Ekind (Etype (P)) = E_Record_Subtype
6631 and then Nkind (Parent (Etype (P))) = N_Subtype_Declaration
6632 and then Is_Array_Type (Etype (Selector))
6633 and then not Is_Packed (Etype (Selector))
6634 and then Available_Subtype
6638 -- Do not build the subtype when referencing components of
6639 -- dispatch table wrappers. Required to avoid generating
6640 -- elaboration code with HI runtimes. JVM and .NET use a
6641 -- modified version of Ada.Tags which does not contain RE_
6642 -- Dispatch_Table_Wrapper and RE_No_Dispatch_Table_Wrapper.
6643 -- Avoid raising RE_Not_Available exception in those cases.
6645 elsif VM_Target = No_VM
6646 and then RTU_Loaded (Ada_Tags)
6648 ((RTE_Available (RE_Dispatch_Table_Wrapper)
6649 and then Scope (Selector) =
6650 RTE (RE_Dispatch_Table_Wrapper))
6652 (RTE_Available (RE_No_Dispatch_Table_Wrapper)
6653 and then Scope (Selector) =
6654 RTE (RE_No_Dispatch_Table_Wrapper)))
6659 Build_Actual_Subtype_Of_Component
6660 (Etype (Selector), N);
6667 if No (C_Etype) then
6668 C_Etype := Etype (Selector);
6670 Insert_Action (N, C_Etype);
6671 C_Etype := Defining_Identifier (C_Etype);
6674 Set_Etype (N, C_Etype);
6677 -- If this is the name of an entry or protected operation, and
6678 -- the prefix is an access type, insert an explicit dereference,
6679 -- so that entry calls are treated uniformly.
6681 if Is_Access_Type (Etype (P))
6682 and then Is_Concurrent_Type (Designated_Type (Etype (P)))
6685 New_P : constant Node_Id :=
6686 Make_Explicit_Dereference (Sloc (P),
6687 Prefix => Relocate_Node (P));
6690 Set_Etype (P, Designated_Type (Etype (Prefix (P))));
6694 -- If the selected component appears within a default expression
6695 -- and it has an actual subtype, the pre-analysis has not yet
6696 -- completed its analysis, because Insert_Actions is disabled in
6697 -- that context. Within the init proc of the enclosing type we
6698 -- must complete this analysis, if an actual subtype was created.
6700 elsif Inside_Init_Proc then
6702 Typ : constant Entity_Id := Etype (N);
6703 Decl : constant Node_Id := Declaration_Node (Typ);
6705 if Nkind (Decl) = N_Subtype_Declaration
6706 and then not Analyzed (Decl)
6707 and then Is_List_Member (Decl)
6708 and then No (Parent (Decl))
6711 Insert_Action (N, Decl);
6718 elsif Is_Entity_Name (P) then
6719 P_Name := Entity (P);
6721 -- The prefix may denote an enclosing type which is the completion
6722 -- of an incomplete type declaration.
6724 if Is_Type (P_Name) then
6725 Set_Entity (P, Get_Full_View (P_Name));
6726 Set_Etype (P, Entity (P));
6727 P_Name := Entity (P);
6730 P_Type := Base_Type (Etype (P));
6732 if Debug_Flag_E then
6733 Write_Str ("Found prefix type to be ");
6734 Write_Entity_Info (P_Type, " "); Write_Eol;
6737 -- The designated type may be a limited view with no components.
6738 -- Check whether the non-limited view is available, because in some
6739 -- cases this will not be set when installing the context.
6741 if Is_Access_Type (P_Type) then
6743 D : constant Entity_Id := Directly_Designated_Type (P_Type);
6745 if Is_Incomplete_Type (D)
6746 and then From_Limited_With (D)
6747 and then Present (Non_Limited_View (D))
6749 Set_Directly_Designated_Type (P_Type, Non_Limited_View (D));
6754 -- First check for components of a record object (not the
6755 -- result of a call, which is handled below).
6757 if Is_Appropriate_For_Record (P_Type)
6758 and then not Is_Overloadable (P_Name)
6759 and then not Is_Type (P_Name)
6761 -- Selected component of record. Type checking will validate
6762 -- name of selector.
6764 -- ??? Could we rewrite an implicit dereference into an explicit
6767 Analyze_Selected_Component (N);
6769 -- Reference to type name in predicate/invariant expression
6771 elsif Is_Appropriate_For_Entry_Prefix (P_Type)
6772 and then not In_Open_Scopes (P_Name)
6773 and then (not Is_Concurrent_Type (Etype (P_Name))
6774 or else not In_Open_Scopes (Etype (P_Name)))
6776 -- Call to protected operation or entry. Type checking is
6777 -- needed on the prefix.
6779 Analyze_Selected_Component (N);
6781 elsif (In_Open_Scopes (P_Name)
6782 and then Ekind (P_Name) /= E_Void
6783 and then not Is_Overloadable (P_Name))
6784 or else (Is_Concurrent_Type (Etype (P_Name))
6785 and then In_Open_Scopes (Etype (P_Name)))
6787 -- Prefix denotes an enclosing loop, block, or task, i.e. an
6788 -- enclosing construct that is not a subprogram or accept.
6790 Find_Expanded_Name (N);
6792 elsif Ekind (P_Name) = E_Package then
6793 Find_Expanded_Name (N);
6795 elsif Is_Overloadable (P_Name) then
6797 -- The subprogram may be a renaming (of an enclosing scope) as
6798 -- in the case of the name of the generic within an instantiation.
6800 if Ekind_In (P_Name, E_Procedure, E_Function)
6801 and then Present (Alias (P_Name))
6802 and then Is_Generic_Instance (Alias (P_Name))
6804 P_Name := Alias (P_Name);
6807 if Is_Overloaded (P) then
6809 -- The prefix must resolve to a unique enclosing construct
6812 Found : Boolean := False;
6817 Get_First_Interp (P, Ind, It);
6818 while Present (It.Nam) loop
6819 if In_Open_Scopes (It.Nam) then
6822 "prefix must be unique enclosing scope", N);
6823 Set_Entity (N, Any_Id);
6824 Set_Etype (N, Any_Type);
6833 Get_Next_Interp (Ind, It);
6838 if In_Open_Scopes (P_Name) then
6839 Set_Entity (P, P_Name);
6840 Set_Is_Overloaded (P, False);
6841 Find_Expanded_Name (N);
6844 -- If no interpretation as an expanded name is possible, it
6845 -- must be a selected component of a record returned by a
6846 -- function call. Reformat prefix as a function call, the rest
6847 -- is done by type resolution.
6849 -- Error if the prefix is procedure or entry, as is P.X
6851 if Ekind (P_Name) /= E_Function
6853 (not Is_Overloaded (P)
6854 or else Nkind (Parent (N)) = N_Procedure_Call_Statement)
6856 -- Prefix may mention a package that is hidden by a local
6857 -- declaration: let the user know. Scan the full homonym
6858 -- chain, the candidate package may be anywhere on it.
6860 if Present (Homonym (Current_Entity (P_Name))) then
6861 P_Name := Current_Entity (P_Name);
6863 while Present (P_Name) loop
6864 exit when Ekind (P_Name) = E_Package;
6865 P_Name := Homonym (P_Name);
6868 if Present (P_Name) then
6869 if not Is_Reference_In_Subunit then
6870 Error_Msg_Sloc := Sloc (Entity (Prefix (N)));
6872 ("package& is hidden by declaration#", N, P_Name);
6875 Set_Entity (Prefix (N), P_Name);
6876 Find_Expanded_Name (N);
6880 P_Name := Entity (Prefix (N));
6885 ("invalid prefix in selected component&", N, P_Name);
6886 Change_Selected_Component_To_Expanded_Name (N);
6887 Set_Entity (N, Any_Id);
6888 Set_Etype (N, Any_Type);
6890 -- Here we have a function call, so do the reformatting
6893 Nam := New_Copy (P);
6894 Save_Interps (P, Nam);
6896 -- We use Replace here because this is one of those cases
6897 -- where the parser has missclassified the node, and we
6898 -- fix things up and then do the semantic analysis on the
6899 -- fixed up node. Normally we do this using one of the
6900 -- Sinfo.CN routines, but this is too tricky for that.
6902 -- Note that using Rewrite would be wrong, because we
6903 -- would have a tree where the original node is unanalyzed,
6904 -- and this violates the required interface for ASIS.
6907 Make_Function_Call (Sloc (P), Name => Nam));
6909 -- Now analyze the reformatted node
6912 Analyze_Selected_Component (N);
6916 -- Remaining cases generate various error messages
6919 -- Format node as expanded name, to avoid cascaded errors
6921 Change_Selected_Component_To_Expanded_Name (N);
6922 Set_Entity (N, Any_Id);
6923 Set_Etype (N, Any_Type);
6925 -- Issue error message, but avoid this if error issued already.
6926 -- Use identifier of prefix if one is available.
6928 if P_Name = Any_Id then
6931 elsif Ekind (P_Name) = E_Void then
6932 Premature_Usage (P);
6934 elsif Nkind (P) /= N_Attribute_Reference then
6936 -- This may have been meant as a prefixed call to a primitive
6937 -- of an untagged type.
6940 F : constant Entity_Id :=
6941 Current_Entity (Selector_Name (N));
6944 and then Is_Overloadable (F)
6945 and then Present (First_Entity (F))
6946 and then Etype (First_Entity (F)) = Etype (P)
6947 and then not Is_Tagged_Type (Etype (P))
6950 ("prefixed call is only allowed for objects "
6951 & "of a tagged type", N);
6955 Error_Msg_N ("invalid prefix in selected component&", P);
6957 if Is_Access_Type (P_Type)
6958 and then Ekind (Designated_Type (P_Type)) = E_Incomplete_Type
6961 ("\dereference must not be of an incomplete type "
6962 & "(RM 3.10.1)", P);
6966 Error_Msg_N ("invalid prefix in selected component", P);
6970 -- Selector name is restricted in SPARK
6972 if Nkind (N) = N_Expanded_Name
6973 and then Restriction_Check_Required (SPARK_05)
6975 if Is_Subprogram (P_Name) then
6976 Check_SPARK_05_Restriction
6977 ("prefix of expanded name cannot be a subprogram", P);
6978 elsif Ekind (P_Name) = E_Loop then
6979 Check_SPARK_05_Restriction
6980 ("prefix of expanded name cannot be a loop statement", P);
6985 -- If prefix is not the name of an entity, it must be an expression,
6986 -- whose type is appropriate for a record. This is determined by
6989 Analyze_Selected_Component (N);
6992 Analyze_Dimension (N);
6993 end Find_Selected_Component;
6999 procedure Find_Type (N : Node_Id) is
7009 elsif Nkind (N) = N_Attribute_Reference then
7011 -- Class attribute. This is not valid in Ada 83 mode, but we do not
7012 -- need to enforce that at this point, since the declaration of the
7013 -- tagged type in the prefix would have been flagged already.
7015 if Attribute_Name (N) = Name_Class then
7016 Check_Restriction (No_Dispatch, N);
7017 Find_Type (Prefix (N));
7019 -- Propagate error from bad prefix
7021 if Etype (Prefix (N)) = Any_Type then
7022 Set_Entity (N, Any_Type);
7023 Set_Etype (N, Any_Type);
7027 T := Base_Type (Entity (Prefix (N)));
7029 -- Case where type is not known to be tagged. Its appearance in
7030 -- the prefix of the 'Class attribute indicates that the full view
7033 if not Is_Tagged_Type (T) then
7034 if Ekind (T) = E_Incomplete_Type then
7036 -- It is legal to denote the class type of an incomplete
7037 -- type. The full type will have to be tagged, of course.
7038 -- In Ada 2005 this usage is declared obsolescent, so we
7039 -- warn accordingly. This usage is only legal if the type
7040 -- is completed in the current scope, and not for a limited
7043 if Ada_Version >= Ada_2005 then
7045 -- Test whether the Available_View of a limited type view
7046 -- is tagged, since the limited view may not be marked as
7047 -- tagged if the type itself has an untagged incomplete
7048 -- type view in its package.
7050 if From_Limited_With (T)
7051 and then not Is_Tagged_Type (Available_View (T))
7054 ("prefix of Class attribute must be tagged", N);
7055 Set_Etype (N, Any_Type);
7056 Set_Entity (N, Any_Type);
7059 -- ??? This test is temporarily disabled (always
7060 -- False) because it causes an unwanted warning on
7061 -- GNAT sources (built with -gnatg, which includes
7062 -- Warn_On_Obsolescent_ Feature). Once this issue
7063 -- is cleared in the sources, it can be enabled.
7065 elsif Warn_On_Obsolescent_Feature and then False then
7067 ("applying 'Class to an untagged incomplete type"
7068 & " is an obsolescent feature (RM J.11)?r?", N);
7072 Set_Is_Tagged_Type (T);
7073 Set_Direct_Primitive_Operations (T, New_Elmt_List);
7074 Make_Class_Wide_Type (T);
7075 Set_Entity (N, Class_Wide_Type (T));
7076 Set_Etype (N, Class_Wide_Type (T));
7078 elsif Ekind (T) = E_Private_Type
7079 and then not Is_Generic_Type (T)
7080 and then In_Private_Part (Scope (T))
7082 -- The Class attribute can be applied to an untagged private
7083 -- type fulfilled by a tagged type prior to the full type
7084 -- declaration (but only within the parent package's private
7085 -- part). Create the class-wide type now and check that the
7086 -- full type is tagged later during its analysis. Note that
7087 -- we do not mark the private type as tagged, unlike the
7088 -- case of incomplete types, because the type must still
7089 -- appear untagged to outside units.
7091 if No (Class_Wide_Type (T)) then
7092 Make_Class_Wide_Type (T);
7095 Set_Entity (N, Class_Wide_Type (T));
7096 Set_Etype (N, Class_Wide_Type (T));
7099 -- Should we introduce a type Any_Tagged and use Wrong_Type
7100 -- here, it would be a bit more consistent???
7103 ("tagged type required, found}",
7104 Prefix (N), First_Subtype (T));
7105 Set_Entity (N, Any_Type);
7109 -- Case of tagged type
7112 if Is_Concurrent_Type (T) then
7113 if No (Corresponding_Record_Type (Entity (Prefix (N)))) then
7115 -- Previous error. Use current type, which at least
7116 -- provides some operations.
7118 C := Entity (Prefix (N));
7121 C := Class_Wide_Type
7122 (Corresponding_Record_Type (Entity (Prefix (N))));
7126 C := Class_Wide_Type (Entity (Prefix (N)));
7129 Set_Entity_With_Checks (N, C);
7130 Generate_Reference (C, N);
7134 -- Base attribute, not allowed in Ada 83
7136 elsif Attribute_Name (N) = Name_Base then
7137 Error_Msg_Name_1 := Name_Base;
7138 Check_SPARK_05_Restriction
7139 ("attribute% is only allowed as prefix of another attribute", N);
7141 if Ada_Version = Ada_83 and then Comes_From_Source (N) then
7143 ("(Ada 83) Base attribute not allowed in subtype mark", N);
7146 Find_Type (Prefix (N));
7147 Typ := Entity (Prefix (N));
7149 if Ada_Version >= Ada_95
7150 and then not Is_Scalar_Type (Typ)
7151 and then not Is_Generic_Type (Typ)
7154 ("prefix of Base attribute must be scalar type",
7157 elsif Warn_On_Redundant_Constructs
7158 and then Base_Type (Typ) = Typ
7160 Error_Msg_NE -- CODEFIX
7161 ("redundant attribute, & is its own base type?r?", N, Typ);
7164 T := Base_Type (Typ);
7166 -- Rewrite attribute reference with type itself (see similar
7167 -- processing in Analyze_Attribute, case Base). Preserve prefix
7168 -- if present, for other legality checks.
7170 if Nkind (Prefix (N)) = N_Expanded_Name then
7172 Make_Expanded_Name (Sloc (N),
7174 Prefix => New_Copy (Prefix (Prefix (N))),
7175 Selector_Name => New_Occurrence_Of (T, Sloc (N))));
7178 Rewrite (N, New_Occurrence_Of (T, Sloc (N)));
7185 elsif Attribute_Name (N) = Name_Stub_Type then
7187 -- This is handled in Analyze_Attribute
7191 -- All other attributes are invalid in a subtype mark
7194 Error_Msg_N ("invalid attribute in subtype mark", N);
7200 if Is_Entity_Name (N) then
7201 T_Name := Entity (N);
7203 Error_Msg_N ("subtype mark required in this context", N);
7204 Set_Etype (N, Any_Type);
7208 if T_Name = Any_Id or else Etype (N) = Any_Type then
7210 -- Undefined id. Make it into a valid type
7212 Set_Entity (N, Any_Type);
7214 elsif not Is_Type (T_Name)
7215 and then T_Name /= Standard_Void_Type
7217 Error_Msg_Sloc := Sloc (T_Name);
7218 Error_Msg_N ("subtype mark required in this context", N);
7219 Error_Msg_NE ("\\found & declared#", N, T_Name);
7220 Set_Entity (N, Any_Type);
7223 -- If the type is an incomplete type created to handle
7224 -- anonymous access components of a record type, then the
7225 -- incomplete type is the visible entity and subsequent
7226 -- references will point to it. Mark the original full
7227 -- type as referenced, to prevent spurious warnings.
7229 if Is_Incomplete_Type (T_Name)
7230 and then Present (Full_View (T_Name))
7231 and then not Comes_From_Source (T_Name)
7233 Set_Referenced (Full_View (T_Name));
7236 T_Name := Get_Full_View (T_Name);
7238 -- Ada 2005 (AI-251, AI-50217): Handle interfaces visible through
7239 -- limited-with clauses
7241 if From_Limited_With (T_Name)
7242 and then Ekind (T_Name) in Incomplete_Kind
7243 and then Present (Non_Limited_View (T_Name))
7244 and then Is_Interface (Non_Limited_View (T_Name))
7246 T_Name := Non_Limited_View (T_Name);
7249 if In_Open_Scopes (T_Name) then
7250 if Ekind (Base_Type (T_Name)) = E_Task_Type then
7252 -- In Ada 2005, a task name can be used in an access
7253 -- definition within its own body. It cannot be used
7254 -- in the discriminant part of the task declaration,
7255 -- nor anywhere else in the declaration because entries
7256 -- cannot have access parameters.
7258 if Ada_Version >= Ada_2005
7259 and then Nkind (Parent (N)) = N_Access_Definition
7261 Set_Entity (N, T_Name);
7262 Set_Etype (N, T_Name);
7264 if Has_Completion (T_Name) then
7269 ("task type cannot be used as type mark " &
7270 "within its own declaration", N);
7275 ("task type cannot be used as type mark " &
7276 "within its own spec or body", N);
7279 elsif Ekind (Base_Type (T_Name)) = E_Protected_Type then
7281 -- In Ada 2005, a protected name can be used in an access
7282 -- definition within its own body.
7284 if Ada_Version >= Ada_2005
7285 and then Nkind (Parent (N)) = N_Access_Definition
7287 Set_Entity (N, T_Name);
7288 Set_Etype (N, T_Name);
7293 ("protected type cannot be used as type mark " &
7294 "within its own spec or body", N);
7298 Error_Msg_N ("type declaration cannot refer to itself", N);
7301 Set_Etype (N, Any_Type);
7302 Set_Entity (N, Any_Type);
7303 Set_Error_Posted (T_Name);
7307 Set_Entity (N, T_Name);
7308 Set_Etype (N, T_Name);
7312 if Present (Etype (N)) and then Comes_From_Source (N) then
7313 if Is_Fixed_Point_Type (Etype (N)) then
7314 Check_Restriction (No_Fixed_Point, N);
7315 elsif Is_Floating_Point_Type (Etype (N)) then
7316 Check_Restriction (No_Floating_Point, N);
7319 -- A Ghost type must appear in a specific context
7321 if Is_Ghost_Entity (Etype (N)) then
7322 Check_Ghost_Context (Etype (N), N);
7327 ------------------------------------
7328 -- Has_Implicit_Character_Literal --
7329 ------------------------------------
7331 function Has_Implicit_Character_Literal (N : Node_Id) return Boolean is
7333 Found : Boolean := False;
7334 P : constant Entity_Id := Entity (Prefix (N));
7335 Priv_Id : Entity_Id := Empty;
7338 if Ekind (P) = E_Package and then not In_Open_Scopes (P) then
7339 Priv_Id := First_Private_Entity (P);
7342 if P = Standard_Standard then
7343 Change_Selected_Component_To_Expanded_Name (N);
7344 Rewrite (N, Selector_Name (N));
7346 Set_Etype (Original_Node (N), Standard_Character);
7350 Id := First_Entity (P);
7351 while Present (Id) and then Id /= Priv_Id loop
7352 if Is_Standard_Character_Type (Id) and then Is_Base_Type (Id) then
7354 -- We replace the node with the literal itself, resolve as a
7355 -- character, and set the type correctly.
7358 Change_Selected_Component_To_Expanded_Name (N);
7359 Rewrite (N, Selector_Name (N));
7362 Set_Etype (Original_Node (N), Id);
7366 -- More than one type derived from Character in given scope.
7367 -- Collect all possible interpretations.
7369 Add_One_Interp (N, Id, Id);
7377 end Has_Implicit_Character_Literal;
7379 ----------------------
7380 -- Has_Private_With --
7381 ----------------------
7383 function Has_Private_With (E : Entity_Id) return Boolean is
7384 Comp_Unit : constant Node_Id := Cunit (Current_Sem_Unit);
7388 Item := First (Context_Items (Comp_Unit));
7389 while Present (Item) loop
7390 if Nkind (Item) = N_With_Clause
7391 and then Private_Present (Item)
7392 and then Entity (Name (Item)) = E
7401 end Has_Private_With;
7403 ---------------------------
7404 -- Has_Implicit_Operator --
7405 ---------------------------
7407 function Has_Implicit_Operator (N : Node_Id) return Boolean is
7408 Op_Id : constant Name_Id := Chars (Selector_Name (N));
7409 P : constant Entity_Id := Entity (Prefix (N));
7411 Priv_Id : Entity_Id := Empty;
7413 procedure Add_Implicit_Operator
7415 Op_Type : Entity_Id := Empty);
7416 -- Add implicit interpretation to node N, using the type for which a
7417 -- predefined operator exists. If the operator yields a boolean type,
7418 -- the Operand_Type is implicitly referenced by the operator, and a
7419 -- reference to it must be generated.
7421 ---------------------------
7422 -- Add_Implicit_Operator --
7423 ---------------------------
7425 procedure Add_Implicit_Operator
7427 Op_Type : Entity_Id := Empty)
7429 Predef_Op : Entity_Id;
7432 Predef_Op := Current_Entity (Selector_Name (N));
7433 while Present (Predef_Op)
7434 and then Scope (Predef_Op) /= Standard_Standard
7436 Predef_Op := Homonym (Predef_Op);
7439 if Nkind (N) = N_Selected_Component then
7440 Change_Selected_Component_To_Expanded_Name (N);
7443 -- If the context is an unanalyzed function call, determine whether
7444 -- a binary or unary interpretation is required.
7446 if Nkind (Parent (N)) = N_Indexed_Component then
7448 Is_Binary_Call : constant Boolean :=
7450 (Next (First (Expressions (Parent (N)))));
7451 Is_Binary_Op : constant Boolean :=
7453 (Predef_Op) /= Last_Entity (Predef_Op);
7454 Predef_Op2 : constant Entity_Id := Homonym (Predef_Op);
7457 if Is_Binary_Call then
7458 if Is_Binary_Op then
7459 Add_One_Interp (N, Predef_Op, T);
7461 Add_One_Interp (N, Predef_Op2, T);
7465 if not Is_Binary_Op then
7466 Add_One_Interp (N, Predef_Op, T);
7468 Add_One_Interp (N, Predef_Op2, T);
7474 Add_One_Interp (N, Predef_Op, T);
7476 -- For operators with unary and binary interpretations, if
7477 -- context is not a call, add both
7479 if Present (Homonym (Predef_Op)) then
7480 Add_One_Interp (N, Homonym (Predef_Op), T);
7484 -- The node is a reference to a predefined operator, and
7485 -- an implicit reference to the type of its operands.
7487 if Present (Op_Type) then
7488 Generate_Operator_Reference (N, Op_Type);
7490 Generate_Operator_Reference (N, T);
7492 end Add_Implicit_Operator;
7494 -- Start of processing for Has_Implicit_Operator
7497 if Ekind (P) = E_Package and then not In_Open_Scopes (P) then
7498 Priv_Id := First_Private_Entity (P);
7501 Id := First_Entity (P);
7505 -- Boolean operators: an implicit declaration exists if the scope
7506 -- contains a declaration for a derived Boolean type, or for an
7507 -- array of Boolean type.
7509 when Name_Op_And | Name_Op_Not | Name_Op_Or | Name_Op_Xor =>
7510 while Id /= Priv_Id loop
7511 if Valid_Boolean_Arg (Id) and then Is_Base_Type (Id) then
7512 Add_Implicit_Operator (Id);
7519 -- Equality: look for any non-limited type (result is Boolean)
7521 when Name_Op_Eq | Name_Op_Ne =>
7522 while Id /= Priv_Id loop
7524 and then not Is_Limited_Type (Id)
7525 and then Is_Base_Type (Id)
7527 Add_Implicit_Operator (Standard_Boolean, Id);
7534 -- Comparison operators: scalar type, or array of scalar
7536 when Name_Op_Lt | Name_Op_Le | Name_Op_Gt | Name_Op_Ge =>
7537 while Id /= Priv_Id loop
7538 if (Is_Scalar_Type (Id)
7539 or else (Is_Array_Type (Id)
7540 and then Is_Scalar_Type (Component_Type (Id))))
7541 and then Is_Base_Type (Id)
7543 Add_Implicit_Operator (Standard_Boolean, Id);
7550 -- Arithmetic operators: any numeric type
7560 while Id /= Priv_Id loop
7561 if Is_Numeric_Type (Id) and then Is_Base_Type (Id) then
7562 Add_Implicit_Operator (Id);
7569 -- Concatenation: any one-dimensional array type
7571 when Name_Op_Concat =>
7572 while Id /= Priv_Id loop
7573 if Is_Array_Type (Id)
7574 and then Number_Dimensions (Id) = 1
7575 and then Is_Base_Type (Id)
7577 Add_Implicit_Operator (Id);
7584 -- What is the others condition here? Should we be using a
7585 -- subtype of Name_Id that would restrict to operators ???
7587 when others => null;
7590 -- If we fall through, then we do not have an implicit operator
7594 end Has_Implicit_Operator;
7596 -----------------------------------
7597 -- Has_Loop_In_Inner_Open_Scopes --
7598 -----------------------------------
7600 function Has_Loop_In_Inner_Open_Scopes (S : Entity_Id) return Boolean is
7602 -- Several scope stacks are maintained by Scope_Stack. The base of the
7603 -- currently active scope stack is denoted by the Is_Active_Stack_Base
7604 -- flag in the scope stack entry. Note that the scope stacks used to
7605 -- simply be delimited implicitly by the presence of Standard_Standard
7606 -- at their base, but there now are cases where this is not sufficient
7607 -- because Standard_Standard actually may appear in the middle of the
7608 -- active set of scopes.
7610 for J in reverse 0 .. Scope_Stack.Last loop
7612 -- S was reached without seing a loop scope first
7614 if Scope_Stack.Table (J).Entity = S then
7617 -- S was not yet reached, so it contains at least one inner loop
7619 elsif Ekind (Scope_Stack.Table (J).Entity) = E_Loop then
7623 -- Check Is_Active_Stack_Base to tell us when to stop, as there are
7624 -- cases where Standard_Standard appears in the middle of the active
7625 -- set of scopes. This affects the declaration and overriding of
7626 -- private inherited operations in instantiations of generic child
7629 pragma Assert (not Scope_Stack.Table (J).Is_Active_Stack_Base);
7632 raise Program_Error; -- unreachable
7633 end Has_Loop_In_Inner_Open_Scopes;
7635 --------------------
7636 -- In_Open_Scopes --
7637 --------------------
7639 function In_Open_Scopes (S : Entity_Id) return Boolean is
7641 -- Several scope stacks are maintained by Scope_Stack. The base of the
7642 -- currently active scope stack is denoted by the Is_Active_Stack_Base
7643 -- flag in the scope stack entry. Note that the scope stacks used to
7644 -- simply be delimited implicitly by the presence of Standard_Standard
7645 -- at their base, but there now are cases where this is not sufficient
7646 -- because Standard_Standard actually may appear in the middle of the
7647 -- active set of scopes.
7649 for J in reverse 0 .. Scope_Stack.Last loop
7650 if Scope_Stack.Table (J).Entity = S then
7654 -- Check Is_Active_Stack_Base to tell us when to stop, as there are
7655 -- cases where Standard_Standard appears in the middle of the active
7656 -- set of scopes. This affects the declaration and overriding of
7657 -- private inherited operations in instantiations of generic child
7660 exit when Scope_Stack.Table (J).Is_Active_Stack_Base;
7666 -----------------------------
7667 -- Inherit_Renamed_Profile --
7668 -----------------------------
7670 procedure Inherit_Renamed_Profile (New_S : Entity_Id; Old_S : Entity_Id) is
7677 if Ekind (Old_S) = E_Operator then
7678 New_F := First_Formal (New_S);
7680 while Present (New_F) loop
7681 Set_Etype (New_F, Base_Type (Etype (New_F)));
7682 Next_Formal (New_F);
7685 Set_Etype (New_S, Base_Type (Etype (New_S)));
7688 New_F := First_Formal (New_S);
7689 Old_F := First_Formal (Old_S);
7691 while Present (New_F) loop
7692 New_T := Etype (New_F);
7693 Old_T := Etype (Old_F);
7695 -- If the new type is a renaming of the old one, as is the
7696 -- case for actuals in instances, retain its name, to simplify
7697 -- later disambiguation.
7699 if Nkind (Parent (New_T)) = N_Subtype_Declaration
7700 and then Is_Entity_Name (Subtype_Indication (Parent (New_T)))
7701 and then Entity (Subtype_Indication (Parent (New_T))) = Old_T
7705 Set_Etype (New_F, Old_T);
7708 Next_Formal (New_F);
7709 Next_Formal (Old_F);
7712 if Ekind_In (Old_S, E_Function, E_Enumeration_Literal) then
7713 Set_Etype (New_S, Etype (Old_S));
7716 end Inherit_Renamed_Profile;
7722 procedure Initialize is
7727 -------------------------
7728 -- Install_Use_Clauses --
7729 -------------------------
7731 procedure Install_Use_Clauses
7733 Force_Installation : Boolean := False)
7741 while Present (U) loop
7743 -- Case of USE package
7745 if Nkind (U) = N_Use_Package_Clause then
7746 P := First (Names (U));
7747 while Present (P) loop
7750 if Ekind (Id) = E_Package then
7752 Note_Redundant_Use (P);
7754 elsif Present (Renamed_Object (Id))
7755 and then In_Use (Renamed_Object (Id))
7757 Note_Redundant_Use (P);
7759 elsif Force_Installation or else Applicable_Use (P) then
7760 Use_One_Package (Id, U);
7771 P := First (Subtype_Marks (U));
7772 while Present (P) loop
7773 if not Is_Entity_Name (P)
7774 or else No (Entity (P))
7778 elsif Entity (P) /= Any_Type then
7786 Next_Use_Clause (U);
7788 end Install_Use_Clauses;
7790 -------------------------------------
7791 -- Is_Appropriate_For_Entry_Prefix --
7792 -------------------------------------
7794 function Is_Appropriate_For_Entry_Prefix (T : Entity_Id) return Boolean is
7795 P_Type : Entity_Id := T;
7798 if Is_Access_Type (P_Type) then
7799 P_Type := Designated_Type (P_Type);
7802 return Is_Task_Type (P_Type) or else Is_Protected_Type (P_Type);
7803 end Is_Appropriate_For_Entry_Prefix;
7805 -------------------------------
7806 -- Is_Appropriate_For_Record --
7807 -------------------------------
7809 function Is_Appropriate_For_Record (T : Entity_Id) return Boolean is
7811 function Has_Components (T1 : Entity_Id) return Boolean;
7812 -- Determine if given type has components (i.e. is either a record
7813 -- type or a type that has discriminants).
7815 --------------------
7816 -- Has_Components --
7817 --------------------
7819 function Has_Components (T1 : Entity_Id) return Boolean is
7821 return Is_Record_Type (T1)
7822 or else (Is_Private_Type (T1) and then Has_Discriminants (T1))
7823 or else (Is_Task_Type (T1) and then Has_Discriminants (T1))
7824 or else (Is_Incomplete_Type (T1)
7825 and then From_Limited_With (T1)
7826 and then Present (Non_Limited_View (T1))
7827 and then Is_Record_Type
7828 (Get_Full_View (Non_Limited_View (T1))));
7831 -- Start of processing for Is_Appropriate_For_Record
7836 and then (Has_Components (T)
7837 or else (Is_Access_Type (T)
7838 and then Has_Components (Designated_Type (T))));
7839 end Is_Appropriate_For_Record;
7841 ------------------------
7842 -- Note_Redundant_Use --
7843 ------------------------
7845 procedure Note_Redundant_Use (Clause : Node_Id) is
7846 Pack_Name : constant Entity_Id := Entity (Clause);
7847 Cur_Use : constant Node_Id := Current_Use_Clause (Pack_Name);
7848 Decl : constant Node_Id := Parent (Clause);
7850 Prev_Use : Node_Id := Empty;
7851 Redundant : Node_Id := Empty;
7852 -- The Use_Clause which is actually redundant. In the simplest case it
7853 -- is Pack itself, but when we compile a body we install its context
7854 -- before that of its spec, in which case it is the use_clause in the
7855 -- spec that will appear to be redundant, and we want the warning to be
7856 -- placed on the body. Similar complications appear when the redundancy
7857 -- is between a child unit and one of its ancestors.
7860 Set_Redundant_Use (Clause, True);
7862 if not Comes_From_Source (Clause)
7864 or else not Warn_On_Redundant_Constructs
7869 if not Is_Compilation_Unit (Current_Scope) then
7871 -- If the use_clause is in an inner scope, it is made redundant by
7872 -- some clause in the current context, with one exception: If we're
7873 -- compiling a nested package body, and the use_clause comes from the
7874 -- corresponding spec, the clause is not necessarily fully redundant,
7875 -- so we should not warn. If a warning was warranted, it would have
7876 -- been given when the spec was processed.
7878 if Nkind (Parent (Decl)) = N_Package_Specification then
7880 Package_Spec_Entity : constant Entity_Id :=
7881 Defining_Unit_Name (Parent (Decl));
7883 if In_Package_Body (Package_Spec_Entity) then
7889 Redundant := Clause;
7890 Prev_Use := Cur_Use;
7892 elsif Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Body then
7894 Cur_Unit : constant Unit_Number_Type := Get_Source_Unit (Cur_Use);
7895 New_Unit : constant Unit_Number_Type := Get_Source_Unit (Clause);
7899 if Cur_Unit = New_Unit then
7901 -- Redundant clause in same body
7903 Redundant := Clause;
7904 Prev_Use := Cur_Use;
7906 elsif Cur_Unit = Current_Sem_Unit then
7908 -- If the new clause is not in the current unit it has been
7909 -- analyzed first, and it makes the other one redundant.
7910 -- However, if the new clause appears in a subunit, Cur_Unit
7911 -- is still the parent, and in that case the redundant one
7912 -- is the one appearing in the subunit.
7914 if Nkind (Unit (Cunit (New_Unit))) = N_Subunit then
7915 Redundant := Clause;
7916 Prev_Use := Cur_Use;
7918 -- Most common case: redundant clause in body,
7919 -- original clause in spec. Current scope is spec entity.
7924 Unit (Library_Unit (Cunit (Current_Sem_Unit))))
7926 Redundant := Cur_Use;
7930 -- The new clause may appear in an unrelated unit, when
7931 -- the parents of a generic are being installed prior to
7932 -- instantiation. In this case there must be no warning.
7933 -- We detect this case by checking whether the current top
7934 -- of the stack is related to the current compilation.
7936 Scop := Current_Scope;
7937 while Present (Scop) and then Scop /= Standard_Standard loop
7938 if Is_Compilation_Unit (Scop)
7939 and then not Is_Child_Unit (Scop)
7943 elsif Scop = Cunit_Entity (Current_Sem_Unit) then
7947 Scop := Scope (Scop);
7950 Redundant := Cur_Use;
7954 elsif New_Unit = Current_Sem_Unit then
7955 Redundant := Clause;
7956 Prev_Use := Cur_Use;
7959 -- Neither is the current unit, so they appear in parent or
7960 -- sibling units. Warning will be emitted elsewhere.
7966 elsif Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Declaration
7967 and then Present (Parent_Spec (Unit (Cunit (Current_Sem_Unit))))
7969 -- Use_clause is in child unit of current unit, and the child unit
7970 -- appears in the context of the body of the parent, so it has been
7971 -- installed first, even though it is the redundant one. Depending on
7972 -- their placement in the context, the visible or the private parts
7973 -- of the two units, either might appear as redundant, but the
7974 -- message has to be on the current unit.
7976 if Get_Source_Unit (Cur_Use) = Current_Sem_Unit then
7977 Redundant := Cur_Use;
7980 Redundant := Clause;
7981 Prev_Use := Cur_Use;
7984 -- If the new use clause appears in the private part of a parent unit
7985 -- it may appear to be redundant w.r.t. a use clause in a child unit,
7986 -- but the previous use clause was needed in the visible part of the
7987 -- child, and no warning should be emitted.
7989 if Nkind (Parent (Decl)) = N_Package_Specification
7991 List_Containing (Decl) = Private_Declarations (Parent (Decl))
7994 Par : constant Entity_Id := Defining_Entity (Parent (Decl));
7995 Spec : constant Node_Id :=
7996 Specification (Unit (Cunit (Current_Sem_Unit)));
7999 if Is_Compilation_Unit (Par)
8000 and then Par /= Cunit_Entity (Current_Sem_Unit)
8001 and then Parent (Cur_Use) = Spec
8003 List_Containing (Cur_Use) = Visible_Declarations (Spec)
8010 -- Finally, if the current use clause is in the context then
8011 -- the clause is redundant when it is nested within the unit.
8013 elsif Nkind (Parent (Cur_Use)) = N_Compilation_Unit
8014 and then Nkind (Parent (Parent (Clause))) /= N_Compilation_Unit
8015 and then Get_Source_Unit (Cur_Use) = Get_Source_Unit (Clause)
8017 Redundant := Clause;
8018 Prev_Use := Cur_Use;
8024 if Present (Redundant) then
8025 Error_Msg_Sloc := Sloc (Prev_Use);
8026 Error_Msg_NE -- CODEFIX
8027 ("& is already use-visible through previous use clause #??",
8028 Redundant, Pack_Name);
8030 end Note_Redundant_Use;
8036 procedure Pop_Scope is
8037 SST : Scope_Stack_Entry renames Scope_Stack.Table (Scope_Stack.Last);
8038 S : constant Entity_Id := SST.Entity;
8041 if Debug_Flag_E then
8045 -- Set Default_Storage_Pool field of the library unit if necessary
8047 if Ekind_In (S, E_Package, E_Generic_Package)
8049 Nkind (Parent (Unit_Declaration_Node (S))) = N_Compilation_Unit
8052 Aux : constant Node_Id :=
8053 Aux_Decls_Node (Parent (Unit_Declaration_Node (S)));
8055 if No (Default_Storage_Pool (Aux)) then
8056 Set_Default_Storage_Pool (Aux, Default_Pool);
8061 Scope_Suppress := SST.Save_Scope_Suppress;
8062 Local_Suppress_Stack_Top := SST.Save_Local_Suppress_Stack_Top;
8063 Check_Policy_List := SST.Save_Check_Policy_List;
8064 Default_Pool := SST.Save_Default_Storage_Pool;
8065 No_Tagged_Streams := SST.Save_No_Tagged_Streams;
8066 SPARK_Mode := SST.Save_SPARK_Mode;
8067 SPARK_Mode_Pragma := SST.Save_SPARK_Mode_Pragma;
8068 Default_SSO := SST.Save_Default_SSO;
8069 Uneval_Old := SST.Save_Uneval_Old;
8071 if Debug_Flag_W then
8072 Write_Str ("<-- exiting scope: ");
8073 Write_Name (Chars (Current_Scope));
8074 Write_Str (", Depth=");
8075 Write_Int (Int (Scope_Stack.Last));
8079 End_Use_Clauses (SST.First_Use_Clause);
8081 -- If the actions to be wrapped are still there they will get lost
8082 -- causing incomplete code to be generated. It is better to abort in
8083 -- this case (and we do the abort even with assertions off since the
8084 -- penalty is incorrect code generation).
8086 if SST.Actions_To_Be_Wrapped /= Scope_Actions'(others => No_List) then
8087 raise Program_Error;
8090 -- Free last subprogram name if allocated, and pop scope
8092 Free (SST.Last_Subprogram_Name);
8093 Scope_Stack.Decrement_Last;
8100 procedure Push_Scope (S : Entity_Id) is
8101 E : constant Entity_Id := Scope (S);
8104 if Ekind (S) = E_Void then
8107 -- Set scope depth if not a non-concurrent type, and we have not yet set
8108 -- the scope depth. This means that we have the first occurrence of the
8109 -- scope, and this is where the depth is set.
8111 elsif (not Is_Type (S) or else Is_Concurrent_Type (S))
8112 and then not Scope_Depth_Set (S)
8114 if S = Standard_Standard then
8115 Set_Scope_Depth_Value (S, Uint_0);
8117 elsif Is_Child_Unit (S) then
8118 Set_Scope_Depth_Value (S, Uint_1);
8120 elsif not Is_Record_Type (Current_Scope) then
8121 if Ekind (S) = E_Loop then
8122 Set_Scope_Depth_Value (S, Scope_Depth (Current_Scope));
8124 Set_Scope_Depth_Value (S, Scope_Depth (Current_Scope) + 1);
8129 Scope_Stack.Increment_Last;
8132 SST : Scope_Stack_Entry renames Scope_Stack.Table (Scope_Stack.Last);
8136 SST.Save_Scope_Suppress := Scope_Suppress;
8137 SST.Save_Local_Suppress_Stack_Top := Local_Suppress_Stack_Top;
8138 SST.Save_Check_Policy_List := Check_Policy_List;
8139 SST.Save_Default_Storage_Pool := Default_Pool;
8140 SST.Save_No_Tagged_Streams := No_Tagged_Streams;
8141 SST.Save_SPARK_Mode := SPARK_Mode;
8142 SST.Save_SPARK_Mode_Pragma := SPARK_Mode_Pragma;
8143 SST.Save_Default_SSO := Default_SSO;
8144 SST.Save_Uneval_Old := Uneval_Old;
8146 if Scope_Stack.Last > Scope_Stack.First then
8147 SST.Component_Alignment_Default := Scope_Stack.Table
8148 (Scope_Stack.Last - 1).
8149 Component_Alignment_Default;
8152 SST.Last_Subprogram_Name := null;
8153 SST.Is_Transient := False;
8154 SST.Node_To_Be_Wrapped := Empty;
8155 SST.Pending_Freeze_Actions := No_List;
8156 SST.Actions_To_Be_Wrapped := (others => No_List);
8157 SST.First_Use_Clause := Empty;
8158 SST.Is_Active_Stack_Base := False;
8159 SST.Previous_Visibility := False;
8160 SST.Locked_Shared_Objects := No_Elist;
8163 if Debug_Flag_W then
8164 Write_Str ("--> new scope: ");
8165 Write_Name (Chars (Current_Scope));
8166 Write_Str (", Id=");
8167 Write_Int (Int (Current_Scope));
8168 Write_Str (", Depth=");
8169 Write_Int (Int (Scope_Stack.Last));
8173 -- Deal with copying flags from the previous scope to this one. This is
8174 -- not necessary if either scope is standard, or if the new scope is a
8177 if S /= Standard_Standard
8178 and then Scope (S) /= Standard_Standard
8179 and then not Is_Child_Unit (S)
8181 if Nkind (E) not in N_Entity then
8185 -- Copy categorization flags from Scope (S) to S, this is not done
8186 -- when Scope (S) is Standard_Standard since propagation is from
8187 -- library unit entity inwards. Copy other relevant attributes as
8188 -- well (Discard_Names in particular).
8190 -- We only propagate inwards for library level entities,
8191 -- inner level subprograms do not inherit the categorization.
8193 if Is_Library_Level_Entity (S) then
8194 Set_Is_Preelaborated (S, Is_Preelaborated (E));
8195 Set_Is_Shared_Passive (S, Is_Shared_Passive (E));
8196 Set_Discard_Names (S, Discard_Names (E));
8197 Set_Suppress_Value_Tracking_On_Call
8198 (S, Suppress_Value_Tracking_On_Call (E));
8199 Set_Categorization_From_Scope (E => S, Scop => E);
8203 if Is_Child_Unit (S)
8204 and then Present (E)
8205 and then Ekind_In (E, E_Package, E_Generic_Package)
8207 Nkind (Parent (Unit_Declaration_Node (E))) = N_Compilation_Unit
8210 Aux : constant Node_Id :=
8211 Aux_Decls_Node (Parent (Unit_Declaration_Node (E)));
8213 if Present (Default_Storage_Pool (Aux)) then
8214 Default_Pool := Default_Storage_Pool (Aux);
8220 ---------------------
8221 -- Premature_Usage --
8222 ---------------------
8224 procedure Premature_Usage (N : Node_Id) is
8225 Kind : constant Node_Kind := Nkind (Parent (Entity (N)));
8226 E : Entity_Id := Entity (N);
8229 -- Within an instance, the analysis of the actual for a formal object
8230 -- does not see the name of the object itself. This is significant only
8231 -- if the object is an aggregate, where its analysis does not do any
8232 -- name resolution on component associations. (see 4717-008). In such a
8233 -- case, look for the visible homonym on the chain.
8235 if In_Instance and then Present (Homonym (E)) then
8237 while Present (E) and then not In_Open_Scopes (Scope (E)) loop
8243 Set_Etype (N, Etype (E));
8248 if Kind = N_Component_Declaration then
8250 ("component&! cannot be used before end of record declaration", N);
8252 elsif Kind = N_Parameter_Specification then
8254 ("formal parameter&! cannot be used before end of specification",
8257 elsif Kind = N_Discriminant_Specification then
8259 ("discriminant&! cannot be used before end of discriminant part",
8262 elsif Kind = N_Procedure_Specification
8263 or else Kind = N_Function_Specification
8266 ("subprogram&! cannot be used before end of its declaration",
8269 elsif Kind = N_Full_Type_Declaration then
8271 ("type& cannot be used before end of its declaration!", N);
8275 ("object& cannot be used before end of its declaration!", N);
8277 end Premature_Usage;
8279 ------------------------
8280 -- Present_System_Aux --
8281 ------------------------
8283 function Present_System_Aux (N : Node_Id := Empty) return Boolean is
8285 Aux_Name : Unit_Name_Type;
8286 Unum : Unit_Number_Type;
8291 function Find_System (C_Unit : Node_Id) return Entity_Id;
8292 -- Scan context clause of compilation unit to find with_clause
8299 function Find_System (C_Unit : Node_Id) return Entity_Id is
8300 With_Clause : Node_Id;
8303 With_Clause := First (Context_Items (C_Unit));
8304 while Present (With_Clause) loop
8305 if (Nkind (With_Clause) = N_With_Clause
8306 and then Chars (Name (With_Clause)) = Name_System)
8307 and then Comes_From_Source (With_Clause)
8318 -- Start of processing for Present_System_Aux
8321 -- The child unit may have been loaded and analyzed already
8323 if Present (System_Aux_Id) then
8326 -- If no previous pragma for System.Aux, nothing to load
8328 elsif No (System_Extend_Unit) then
8331 -- Use the unit name given in the pragma to retrieve the unit.
8332 -- Verify that System itself appears in the context clause of the
8333 -- current compilation. If System is not present, an error will
8334 -- have been reported already.
8337 With_Sys := Find_System (Cunit (Current_Sem_Unit));
8339 The_Unit := Unit (Cunit (Current_Sem_Unit));
8343 (Nkind (The_Unit) = N_Package_Body
8344 or else (Nkind (The_Unit) = N_Subprogram_Body
8345 and then not Acts_As_Spec (Cunit (Current_Sem_Unit))))
8347 With_Sys := Find_System (Library_Unit (Cunit (Current_Sem_Unit)));
8350 if No (With_Sys) and then Present (N) then
8352 -- If we are compiling a subunit, we need to examine its
8353 -- context as well (Current_Sem_Unit is the parent unit);
8355 The_Unit := Parent (N);
8356 while Nkind (The_Unit) /= N_Compilation_Unit loop
8357 The_Unit := Parent (The_Unit);
8360 if Nkind (Unit (The_Unit)) = N_Subunit then
8361 With_Sys := Find_System (The_Unit);
8365 if No (With_Sys) then
8369 Loc := Sloc (With_Sys);
8370 Get_Name_String (Chars (Expression (System_Extend_Unit)));
8371 Name_Buffer (8 .. Name_Len + 7) := Name_Buffer (1 .. Name_Len);
8372 Name_Buffer (1 .. 7) := "system.";
8373 Name_Buffer (Name_Len + 8) := '%';
8374 Name_Buffer (Name_Len + 9) := 's';
8375 Name_Len := Name_Len + 9;
8376 Aux_Name := Name_Find;
8380 (Load_Name => Aux_Name,
8383 Error_Node => With_Sys);
8385 if Unum /= No_Unit then
8386 Semantics (Cunit (Unum));
8388 Defining_Entity (Specification (Unit (Cunit (Unum))));
8391 Make_With_Clause (Loc,
8393 Make_Expanded_Name (Loc,
8394 Chars => Chars (System_Aux_Id),
8395 Prefix => New_Occurrence_Of (Scope (System_Aux_Id), Loc),
8396 Selector_Name => New_Occurrence_Of (System_Aux_Id, Loc)));
8398 Set_Entity (Name (Withn), System_Aux_Id);
8400 Set_Library_Unit (Withn, Cunit (Unum));
8401 Set_Corresponding_Spec (Withn, System_Aux_Id);
8402 Set_First_Name (Withn, True);
8403 Set_Implicit_With (Withn, True);
8405 Insert_After (With_Sys, Withn);
8406 Mark_Rewrite_Insertion (Withn);
8407 Set_Context_Installed (Withn);
8411 -- Here if unit load failed
8414 Error_Msg_Name_1 := Name_System;
8415 Error_Msg_Name_2 := Chars (Expression (System_Extend_Unit));
8417 ("extension package `%.%` does not exist",
8418 Opt.System_Extend_Unit);
8422 end Present_System_Aux;
8424 -------------------------
8425 -- Restore_Scope_Stack --
8426 -------------------------
8428 procedure Restore_Scope_Stack
8430 Handle_Use : Boolean := True)
8432 SS_Last : constant Int := Scope_Stack.Last;
8436 -- Restore visibility of previous scope stack, if any, using the list
8437 -- we saved (we use Remove, since this list will not be used again).
8440 Elmt := Last_Elmt (List);
8441 exit when Elmt = No_Elmt;
8442 Set_Is_Immediately_Visible (Node (Elmt));
8443 Remove_Last_Elmt (List);
8446 -- Restore use clauses
8448 if SS_Last >= Scope_Stack.First
8449 and then Scope_Stack.Table (SS_Last).Entity /= Standard_Standard
8452 Install_Use_Clauses (Scope_Stack.Table (SS_Last).First_Use_Clause);
8454 end Restore_Scope_Stack;
8456 ----------------------
8457 -- Save_Scope_Stack --
8458 ----------------------
8460 -- Save_Scope_Stack/Restore_Scope_Stack were originally designed to avoid
8461 -- consuming any memory. That is, Save_Scope_Stack took care of removing
8462 -- from immediate visibility entities and Restore_Scope_Stack took care
8463 -- of restoring their visibility analyzing the context of each entity. The
8464 -- problem of such approach is that it was fragile and caused unexpected
8465 -- visibility problems, and indeed one test was found where there was a
8468 -- Furthermore, the following experiment was carried out:
8470 -- - Save_Scope_Stack was modified to store in an Elist1 all those
8471 -- entities whose attribute Is_Immediately_Visible is modified
8472 -- from True to False.
8474 -- - Restore_Scope_Stack was modified to store in another Elist2
8475 -- all the entities whose attribute Is_Immediately_Visible is
8476 -- modified from False to True.
8478 -- - Extra code was added to verify that all the elements of Elist1
8479 -- are found in Elist2
8481 -- This test shows that there may be more occurrences of this problem which
8482 -- have not yet been detected. As a result, we replaced that approach by
8483 -- the current one in which Save_Scope_Stack returns the list of entities
8484 -- whose visibility is changed, and that list is passed to Restore_Scope_
8485 -- Stack to undo that change. This approach is simpler and safer, although
8486 -- it consumes more memory.
8488 function Save_Scope_Stack (Handle_Use : Boolean := True) return Elist_Id is
8489 Result : constant Elist_Id := New_Elmt_List;
8492 SS_Last : constant Int := Scope_Stack.Last;
8494 procedure Remove_From_Visibility (E : Entity_Id);
8495 -- If E is immediately visible then append it to the result and remove
8496 -- it temporarily from visibility.
8498 ----------------------------
8499 -- Remove_From_Visibility --
8500 ----------------------------
8502 procedure Remove_From_Visibility (E : Entity_Id) is
8504 if Is_Immediately_Visible (E) then
8505 Append_Elmt (E, Result);
8506 Set_Is_Immediately_Visible (E, False);
8508 end Remove_From_Visibility;
8510 -- Start of processing for Save_Scope_Stack
8513 if SS_Last >= Scope_Stack.First
8514 and then Scope_Stack.Table (SS_Last).Entity /= Standard_Standard
8517 End_Use_Clauses (Scope_Stack.Table (SS_Last).First_Use_Clause);
8520 -- If the call is from within a compilation unit, as when called from
8521 -- Rtsfind, make current entries in scope stack invisible while we
8522 -- analyze the new unit.
8524 for J in reverse 0 .. SS_Last loop
8525 exit when Scope_Stack.Table (J).Entity = Standard_Standard
8526 or else No (Scope_Stack.Table (J).Entity);
8528 S := Scope_Stack.Table (J).Entity;
8530 Remove_From_Visibility (S);
8532 E := First_Entity (S);
8533 while Present (E) loop
8534 Remove_From_Visibility (E);
8542 end Save_Scope_Stack;
8548 procedure Set_Use (L : List_Id) is
8550 Pack_Name : Node_Id;
8557 while Present (Decl) loop
8558 if Nkind (Decl) = N_Use_Package_Clause then
8559 Chain_Use_Clause (Decl);
8561 Pack_Name := First (Names (Decl));
8562 while Present (Pack_Name) loop
8563 Pack := Entity (Pack_Name);
8565 if Ekind (Pack) = E_Package
8566 and then Applicable_Use (Pack_Name)
8568 Use_One_Package (Pack, Decl);
8574 elsif Nkind (Decl) = N_Use_Type_Clause then
8575 Chain_Use_Clause (Decl);
8577 Id := First (Subtype_Marks (Decl));
8578 while Present (Id) loop
8579 if Entity (Id) /= Any_Type then
8592 ---------------------
8593 -- Use_One_Package --
8594 ---------------------
8596 procedure Use_One_Package (P : Entity_Id; N : Node_Id) is
8599 Current_Instance : Entity_Id := Empty;
8601 Private_With_OK : Boolean := False;
8604 if Ekind (P) /= E_Package then
8609 Set_Current_Use_Clause (P, N);
8611 -- Ada 2005 (AI-50217): Check restriction
8613 if From_Limited_With (P) then
8614 Error_Msg_N ("limited withed package cannot appear in use clause", N);
8617 -- Find enclosing instance, if any
8620 Current_Instance := Current_Scope;
8621 while not Is_Generic_Instance (Current_Instance) loop
8622 Current_Instance := Scope (Current_Instance);
8625 if No (Hidden_By_Use_Clause (N)) then
8626 Set_Hidden_By_Use_Clause (N, New_Elmt_List);
8630 -- If unit is a package renaming, indicate that the renamed
8631 -- package is also in use (the flags on both entities must
8632 -- remain consistent, and a subsequent use of either of them
8633 -- should be recognized as redundant).
8635 if Present (Renamed_Object (P)) then
8636 Set_In_Use (Renamed_Object (P));
8637 Set_Current_Use_Clause (Renamed_Object (P), N);
8638 Real_P := Renamed_Object (P);
8643 -- Ada 2005 (AI-262): Check the use_clause of a private withed package
8644 -- found in the private part of a package specification
8646 if In_Private_Part (Current_Scope)
8647 and then Has_Private_With (P)
8648 and then Is_Child_Unit (Current_Scope)
8649 and then Is_Child_Unit (P)
8650 and then Is_Ancestor_Package (Scope (Current_Scope), P)
8652 Private_With_OK := True;
8655 -- Loop through entities in one package making them potentially
8658 Id := First_Entity (P);
8660 and then (Id /= First_Private_Entity (P)
8661 or else Private_With_OK) -- Ada 2005 (AI-262)
8663 Prev := Current_Entity (Id);
8664 while Present (Prev) loop
8665 if Is_Immediately_Visible (Prev)
8666 and then (not Is_Overloadable (Prev)
8667 or else not Is_Overloadable (Id)
8668 or else (Type_Conformant (Id, Prev)))
8670 if No (Current_Instance) then
8672 -- Potentially use-visible entity remains hidden
8674 goto Next_Usable_Entity;
8676 -- A use clause within an instance hides outer global entities,
8677 -- which are not used to resolve local entities in the
8678 -- instance. Note that the predefined entities in Standard
8679 -- could not have been hidden in the generic by a use clause,
8680 -- and therefore remain visible. Other compilation units whose
8681 -- entities appear in Standard must be hidden in an instance.
8683 -- To determine whether an entity is external to the instance
8684 -- we compare the scope depth of its scope with that of the
8685 -- current instance. However, a generic actual of a subprogram
8686 -- instance is declared in the wrapper package but will not be
8687 -- hidden by a use-visible entity. similarly, an entity that is
8688 -- declared in an enclosing instance will not be hidden by an
8689 -- an entity declared in a generic actual, which can only have
8690 -- been use-visible in the generic and will not have hidden the
8691 -- entity in the generic parent.
8693 -- If Id is called Standard, the predefined package with the
8694 -- same name is in the homonym chain. It has to be ignored
8695 -- because it has no defined scope (being the only entity in
8696 -- the system with this mandated behavior).
8698 elsif not Is_Hidden (Id)
8699 and then Present (Scope (Prev))
8700 and then not Is_Wrapper_Package (Scope (Prev))
8701 and then Scope_Depth (Scope (Prev)) <
8702 Scope_Depth (Current_Instance)
8703 and then (Scope (Prev) /= Standard_Standard
8704 or else Sloc (Prev) > Standard_Location)
8706 if In_Open_Scopes (Scope (Prev))
8707 and then Is_Generic_Instance (Scope (Prev))
8708 and then Present (Associated_Formal_Package (P))
8713 Set_Is_Potentially_Use_Visible (Id);
8714 Set_Is_Immediately_Visible (Prev, False);
8715 Append_Elmt (Prev, Hidden_By_Use_Clause (N));
8719 -- A user-defined operator is not use-visible if the predefined
8720 -- operator for the type is immediately visible, which is the case
8721 -- if the type of the operand is in an open scope. This does not
8722 -- apply to user-defined operators that have operands of different
8723 -- types, because the predefined mixed mode operations (multiply
8724 -- and divide) apply to universal types and do not hide anything.
8726 elsif Ekind (Prev) = E_Operator
8727 and then Operator_Matches_Spec (Prev, Id)
8728 and then In_Open_Scopes
8729 (Scope (Base_Type (Etype (First_Formal (Id)))))
8730 and then (No (Next_Formal (First_Formal (Id)))
8731 or else Etype (First_Formal (Id)) =
8732 Etype (Next_Formal (First_Formal (Id)))
8733 or else Chars (Prev) = Name_Op_Expon)
8735 goto Next_Usable_Entity;
8737 -- In an instance, two homonyms may become use_visible through the
8738 -- actuals of distinct formal packages. In the generic, only the
8739 -- current one would have been visible, so make the other one
8742 elsif Present (Current_Instance)
8743 and then Is_Potentially_Use_Visible (Prev)
8744 and then not Is_Overloadable (Prev)
8745 and then Scope (Id) /= Scope (Prev)
8746 and then Used_As_Generic_Actual (Scope (Prev))
8747 and then Used_As_Generic_Actual (Scope (Id))
8748 and then not In_Same_List (Current_Use_Clause (Scope (Prev)),
8749 Current_Use_Clause (Scope (Id)))
8751 Set_Is_Potentially_Use_Visible (Prev, False);
8752 Append_Elmt (Prev, Hidden_By_Use_Clause (N));
8755 Prev := Homonym (Prev);
8758 -- On exit, we know entity is not hidden, unless it is private
8760 if not Is_Hidden (Id)
8761 and then ((not Is_Child_Unit (Id)) or else Is_Visible_Lib_Unit (Id))
8763 Set_Is_Potentially_Use_Visible (Id);
8765 if Is_Private_Type (Id) and then Present (Full_View (Id)) then
8766 Set_Is_Potentially_Use_Visible (Full_View (Id));
8770 <<Next_Usable_Entity>>
8774 -- Child units are also made use-visible by a use clause, but they may
8775 -- appear after all visible declarations in the parent entity list.
8777 while Present (Id) loop
8778 if Is_Child_Unit (Id) and then Is_Visible_Lib_Unit (Id) then
8779 Set_Is_Potentially_Use_Visible (Id);
8785 if Chars (Real_P) = Name_System
8786 and then Scope (Real_P) = Standard_Standard
8787 and then Present_System_Aux (N)
8789 Use_One_Package (System_Aux_Id, N);
8792 end Use_One_Package;
8798 procedure Use_One_Type (Id : Node_Id; Installed : Boolean := False) is
8800 Is_Known_Used : Boolean;
8804 function Spec_Reloaded_For_Body return Boolean;
8805 -- Determine whether the compilation unit is a package body and the use
8806 -- type clause is in the spec of the same package. Even though the spec
8807 -- was analyzed first, its context is reloaded when analysing the body.
8809 procedure Use_Class_Wide_Operations (Typ : Entity_Id);
8810 -- AI05-150: if the use_type_clause carries the "all" qualifier,
8811 -- class-wide operations of ancestor types are use-visible if the
8812 -- ancestor type is visible.
8814 ----------------------------
8815 -- Spec_Reloaded_For_Body --
8816 ----------------------------
8818 function Spec_Reloaded_For_Body return Boolean is
8820 if Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Body then
8822 Spec : constant Node_Id :=
8823 Parent (List_Containing (Parent (Id)));
8826 -- Check whether type is declared in a package specification,
8827 -- and current unit is the corresponding package body. The
8828 -- use clauses themselves may be within a nested package.
8831 Nkind (Spec) = N_Package_Specification
8833 In_Same_Source_Unit (Corresponding_Body (Parent (Spec)),
8834 Cunit_Entity (Current_Sem_Unit));
8839 end Spec_Reloaded_For_Body;
8841 -------------------------------
8842 -- Use_Class_Wide_Operations --
8843 -------------------------------
8845 procedure Use_Class_Wide_Operations (Typ : Entity_Id) is
8849 function Is_Class_Wide_Operation_Of
8851 T : Entity_Id) return Boolean;
8852 -- Determine whether a subprogram has a class-wide parameter or
8853 -- result that is T'Class.
8855 ---------------------------------
8856 -- Is_Class_Wide_Operation_Of --
8857 ---------------------------------
8859 function Is_Class_Wide_Operation_Of
8861 T : Entity_Id) return Boolean
8866 Formal := First_Formal (Op);
8867 while Present (Formal) loop
8868 if Etype (Formal) = Class_Wide_Type (T) then
8871 Next_Formal (Formal);
8874 if Etype (Op) = Class_Wide_Type (T) then
8879 end Is_Class_Wide_Operation_Of;
8881 -- Start of processing for Use_Class_Wide_Operations
8884 Scop := Scope (Typ);
8885 if not Is_Hidden (Scop) then
8886 Ent := First_Entity (Scop);
8887 while Present (Ent) loop
8888 if Is_Overloadable (Ent)
8889 and then Is_Class_Wide_Operation_Of (Ent, Typ)
8890 and then not Is_Potentially_Use_Visible (Ent)
8892 Set_Is_Potentially_Use_Visible (Ent);
8893 Append_Elmt (Ent, Used_Operations (Parent (Id)));
8900 if Is_Derived_Type (Typ) then
8901 Use_Class_Wide_Operations (Etype (Base_Type (Typ)));
8903 end Use_Class_Wide_Operations;
8905 -- Start of processing for Use_One_Type
8908 -- It is the type determined by the subtype mark (8.4(8)) whose
8909 -- operations become potentially use-visible.
8911 T := Base_Type (Entity (Id));
8913 -- Either the type itself is used, the package where it is declared
8914 -- is in use or the entity is declared in the current package, thus
8919 or else In_Use (Scope (T))
8920 or else Scope (T) = Current_Scope;
8922 Set_Redundant_Use (Id,
8923 Is_Known_Used or else Is_Potentially_Use_Visible (T));
8925 if Ekind (T) = E_Incomplete_Type then
8926 Error_Msg_N ("premature usage of incomplete type", Id);
8928 elsif In_Open_Scopes (Scope (T)) then
8931 -- A limited view cannot appear in a use_type clause. However, an access
8932 -- type whose designated type is limited has the flag but is not itself
8933 -- a limited view unless we only have a limited view of its enclosing
8936 elsif From_Limited_With (T) and then From_Limited_With (Scope (T)) then
8938 ("incomplete type from limited view "
8939 & "cannot appear in use clause", Id);
8941 -- If the subtype mark designates a subtype in a different package,
8942 -- we have to check that the parent type is visible, otherwise the
8943 -- use type clause is a noop. Not clear how to do that???
8945 elsif not Redundant_Use (Id) then
8948 -- If T is tagged, primitive operators on class-wide operands
8949 -- are also available.
8951 if Is_Tagged_Type (T) then
8952 Set_In_Use (Class_Wide_Type (T));
8955 Set_Current_Use_Clause (T, Parent (Id));
8957 -- Iterate over primitive operations of the type. If an operation is
8958 -- already use_visible, it is the result of a previous use_clause,
8959 -- and already appears on the corresponding entity chain. If the
8960 -- clause is being reinstalled, operations are already use-visible.
8966 Op_List := Collect_Primitive_Operations (T);
8967 Elmt := First_Elmt (Op_List);
8968 while Present (Elmt) loop
8969 if (Nkind (Node (Elmt)) = N_Defining_Operator_Symbol
8970 or else Chars (Node (Elmt)) in Any_Operator_Name)
8971 and then not Is_Hidden (Node (Elmt))
8972 and then not Is_Potentially_Use_Visible (Node (Elmt))
8974 Set_Is_Potentially_Use_Visible (Node (Elmt));
8975 Append_Elmt (Node (Elmt), Used_Operations (Parent (Id)));
8977 elsif Ada_Version >= Ada_2012
8978 and then All_Present (Parent (Id))
8979 and then not Is_Hidden (Node (Elmt))
8980 and then not Is_Potentially_Use_Visible (Node (Elmt))
8982 Set_Is_Potentially_Use_Visible (Node (Elmt));
8983 Append_Elmt (Node (Elmt), Used_Operations (Parent (Id)));
8990 if Ada_Version >= Ada_2012
8991 and then All_Present (Parent (Id))
8992 and then Is_Tagged_Type (T)
8994 Use_Class_Wide_Operations (T);
8998 -- If warning on redundant constructs, check for unnecessary WITH
9000 if Warn_On_Redundant_Constructs
9001 and then Is_Known_Used
9003 -- with P; with P; use P;
9004 -- package P is package X is package body X is
9005 -- type T ... use P.T;
9007 -- The compilation unit is the body of X. GNAT first compiles the
9008 -- spec of X, then proceeds to the body. At that point P is marked
9009 -- as use visible. The analysis then reinstalls the spec along with
9010 -- its context. The use clause P.T is now recognized as redundant,
9011 -- but in the wrong context. Do not emit a warning in such cases.
9012 -- Do not emit a warning either if we are in an instance, there is
9013 -- no redundancy between an outer use_clause and one that appears
9014 -- within the generic.
9016 and then not Spec_Reloaded_For_Body
9017 and then not In_Instance
9019 -- The type already has a use clause
9023 -- Case where we know the current use clause for the type
9025 if Present (Current_Use_Clause (T)) then
9026 Use_Clause_Known : declare
9027 Clause1 : constant Node_Id := Parent (Id);
9028 Clause2 : constant Node_Id := Current_Use_Clause (T);
9035 function Entity_Of_Unit (U : Node_Id) return Entity_Id;
9036 -- Return the appropriate entity for determining which unit
9037 -- has a deeper scope: the defining entity for U, unless U
9038 -- is a package instance, in which case we retrieve the
9039 -- entity of the instance spec.
9041 --------------------
9042 -- Entity_Of_Unit --
9043 --------------------
9045 function Entity_Of_Unit (U : Node_Id) return Entity_Id is
9047 if Nkind (U) = N_Package_Instantiation
9048 and then Analyzed (U)
9050 return Defining_Entity (Instance_Spec (U));
9052 return Defining_Entity (U);
9056 -- Start of processing for Use_Clause_Known
9059 -- If both current use type clause and the use type clause
9060 -- for the type are at the compilation unit level, one of
9061 -- the units must be an ancestor of the other, and the
9062 -- warning belongs on the descendant.
9064 if Nkind (Parent (Clause1)) = N_Compilation_Unit
9066 Nkind (Parent (Clause2)) = N_Compilation_Unit
9068 -- If the unit is a subprogram body that acts as spec,
9069 -- the context clause is shared with the constructed
9070 -- subprogram spec. Clearly there is no redundancy.
9072 if Clause1 = Clause2 then
9076 Unit1 := Unit (Parent (Clause1));
9077 Unit2 := Unit (Parent (Clause2));
9079 -- If both clauses are on same unit, or one is the body
9080 -- of the other, or one of them is in a subunit, report
9081 -- redundancy on the later one.
9083 if Unit1 = Unit2 then
9084 Error_Msg_Sloc := Sloc (Current_Use_Clause (T));
9085 Error_Msg_NE -- CODEFIX
9086 ("& is already use-visible through previous "
9087 & "use_type_clause #??", Clause1, T);
9090 elsif Nkind (Unit1) = N_Subunit then
9091 Error_Msg_Sloc := Sloc (Current_Use_Clause (T));
9092 Error_Msg_NE -- CODEFIX
9093 ("& is already use-visible through previous "
9094 & "use_type_clause #??", Clause1, T);
9097 elsif Nkind_In (Unit2, N_Package_Body, N_Subprogram_Body)
9098 and then Nkind (Unit1) /= Nkind (Unit2)
9099 and then Nkind (Unit1) /= N_Subunit
9101 Error_Msg_Sloc := Sloc (Clause1);
9102 Error_Msg_NE -- CODEFIX
9103 ("& is already use-visible through previous "
9104 & "use_type_clause #??", Current_Use_Clause (T), T);
9108 -- There is a redundant use type clause in a child unit.
9109 -- Determine which of the units is more deeply nested.
9110 -- If a unit is a package instance, retrieve the entity
9111 -- and its scope from the instance spec.
9113 Ent1 := Entity_Of_Unit (Unit1);
9114 Ent2 := Entity_Of_Unit (Unit2);
9116 if Scope (Ent2) = Standard_Standard then
9117 Error_Msg_Sloc := Sloc (Current_Use_Clause (T));
9120 elsif Scope (Ent1) = Standard_Standard then
9121 Error_Msg_Sloc := Sloc (Id);
9124 -- If both units are child units, we determine which one
9125 -- is the descendant by the scope distance to the
9126 -- ultimate parent unit.
9136 and then Present (S2)
9137 and then S1 /= Standard_Standard
9138 and then S2 /= Standard_Standard
9144 if S1 = Standard_Standard then
9145 Error_Msg_Sloc := Sloc (Id);
9148 Error_Msg_Sloc := Sloc (Current_Use_Clause (T));
9154 Error_Msg_NE -- CODEFIX
9155 ("& is already use-visible through previous "
9156 & "use_type_clause #??", Err_No, Id);
9158 -- Case where current use type clause and the use type
9159 -- clause for the type are not both at the compilation unit
9160 -- level. In this case we don't have location information.
9163 Error_Msg_NE -- CODEFIX
9164 ("& is already use-visible through previous "
9165 & "use type clause??", Id, T);
9167 end Use_Clause_Known;
9169 -- Here if Current_Use_Clause is not set for T, another case
9170 -- where we do not have the location information available.
9173 Error_Msg_NE -- CODEFIX
9174 ("& is already use-visible through previous "
9175 & "use type clause??", Id, T);
9178 -- The package where T is declared is already used
9180 elsif In_Use (Scope (T)) then
9181 Error_Msg_Sloc := Sloc (Current_Use_Clause (Scope (T)));
9182 Error_Msg_NE -- CODEFIX
9183 ("& is already use-visible through package use clause #??",
9186 -- The current scope is the package where T is declared
9189 Error_Msg_Node_2 := Scope (T);
9190 Error_Msg_NE -- CODEFIX
9191 ("& is already use-visible inside package &??", Id, T);
9200 procedure Write_Info is
9201 Id : Entity_Id := First_Entity (Current_Scope);
9204 -- No point in dumping standard entities
9206 if Current_Scope = Standard_Standard then
9210 Write_Str ("========================================================");
9212 Write_Str (" Defined Entities in ");
9213 Write_Name (Chars (Current_Scope));
9215 Write_Str ("========================================================");
9219 Write_Str ("-- none --");
9223 while Present (Id) loop
9224 Write_Entity_Info (Id, " ");
9229 if Scope (Current_Scope) = Standard_Standard then
9231 -- Print information on the current unit itself
9233 Write_Entity_Info (Current_Scope, " ");
9246 for J in reverse 1 .. Scope_Stack.Last loop
9247 S := Scope_Stack.Table (J).Entity;
9248 Write_Int (Int (S));
9249 Write_Str (" === ");
9250 Write_Name (Chars (S));
9259 procedure we (S : Entity_Id) is
9262 E := First_Entity (S);
9263 while Present (E) loop
9264 Write_Int (Int (E));
9265 Write_Str (" === ");
9266 Write_Name (Chars (E));