1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2010, 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_Tss; use Exp_Tss;
32 with Exp_Util; use Exp_Util;
33 with Fname; use Fname;
34 with Freeze; use Freeze;
35 with Impunit; use Impunit;
37 with Lib.Load; use Lib.Load;
38 with Lib.Xref; use Lib.Xref;
39 with Namet; use Namet;
40 with Namet.Sp; use Namet.Sp;
41 with Nlists; use Nlists;
42 with Nmake; use Nmake;
44 with Output; use Output;
45 with Restrict; use Restrict;
46 with Rident; use Rident;
47 with Rtsfind; use Rtsfind;
49 with Sem_Aux; use Sem_Aux;
50 with Sem_Cat; use Sem_Cat;
51 with Sem_Ch3; use Sem_Ch3;
52 with Sem_Ch4; use Sem_Ch4;
53 with Sem_Ch6; use Sem_Ch6;
54 with Sem_Ch12; use Sem_Ch12;
55 with Sem_Disp; use Sem_Disp;
56 with Sem_Dist; use Sem_Dist;
57 with Sem_Eval; use Sem_Eval;
58 with Sem_Res; use Sem_Res;
59 with Sem_Util; use Sem_Util;
60 with Sem_Type; use Sem_Type;
61 with Stand; use Stand;
62 with Sinfo; use Sinfo;
63 with Sinfo.CN; use Sinfo.CN;
64 with Snames; use Snames;
65 with Style; use Style;
67 with Targparm; use Targparm;
68 with Tbuild; use Tbuild;
69 with Uintp; use Uintp;
71 package body Sem_Ch8 is
73 ------------------------------------
74 -- Visibility and Name Resolution --
75 ------------------------------------
77 -- This package handles name resolution and the collection of
78 -- interpretations for overloaded names, prior to overload resolution.
80 -- Name resolution is the process that establishes a mapping between source
81 -- identifiers and the entities they denote at each point in the program.
82 -- Each entity is represented by a defining occurrence. Each identifier
83 -- that denotes an entity points to the corresponding defining occurrence.
84 -- This is the entity of the applied occurrence. Each occurrence holds
85 -- an index into the names table, where source identifiers are stored.
87 -- Each entry in the names table for an identifier or designator uses the
88 -- Info pointer to hold a link to the currently visible entity that has
89 -- this name (see subprograms Get_Name_Entity_Id and Set_Name_Entity_Id
90 -- in package Sem_Util). The visibility is initialized at the beginning of
91 -- semantic processing to make entities in package Standard immediately
92 -- visible. The visibility table is used in a more subtle way when
93 -- compiling subunits (see below).
95 -- Entities that have the same name (i.e. homonyms) are chained. In the
96 -- case of overloaded entities, this chain holds all the possible meanings
97 -- of a given identifier. The process of overload resolution uses type
98 -- information to select from this chain the unique meaning of a given
101 -- Entities are also chained in their scope, through the Next_Entity link.
102 -- As a consequence, the name space is organized as a sparse matrix, where
103 -- each row corresponds to a scope, and each column to a source identifier.
104 -- Open scopes, that is to say scopes currently being compiled, have their
105 -- corresponding rows of entities in order, innermost scope first.
107 -- The scopes of packages that are mentioned in context clauses appear in
108 -- no particular order, interspersed among open scopes. This is because
109 -- in the course of analyzing the context of a compilation, a package
110 -- declaration is first an open scope, and subsequently an element of the
111 -- context. If subunits or child units are present, a parent unit may
112 -- appear under various guises at various times in the compilation.
114 -- When the compilation of the innermost scope is complete, the entities
115 -- defined therein are no longer visible. If the scope is not a package
116 -- declaration, these entities are never visible subsequently, and can be
117 -- removed from visibility chains. If the scope is a package declaration,
118 -- its visible declarations may still be accessible. Therefore the entities
119 -- defined in such a scope are left on the visibility chains, and only
120 -- their visibility (immediately visibility or potential use-visibility)
123 -- The ordering of homonyms on their chain does not necessarily follow
124 -- the order of their corresponding scopes on the scope stack. For
125 -- example, if package P and the enclosing scope both contain entities
126 -- named E, then when compiling the package body the chain for E will
127 -- hold the global entity first, and the local one (corresponding to
128 -- the current inner scope) next. As a result, name resolution routines
129 -- do not assume any relative ordering of the homonym chains, either
130 -- for scope nesting or to order of appearance of context clauses.
132 -- When compiling a child unit, entities in the parent scope are always
133 -- immediately visible. When compiling the body of a child unit, private
134 -- entities in the parent must also be made immediately visible. There
135 -- are separate routines to make the visible and private declarations
136 -- visible at various times (see package Sem_Ch7).
138 -- +--------+ +-----+
139 -- | In use |-------->| EU1 |-------------------------->
140 -- +--------+ +-----+
142 -- +--------+ +-----+ +-----+
143 -- | Stand. |---------------->| ES1 |--------------->| ES2 |--->
144 -- +--------+ +-----+ +-----+
146 -- +---------+ | +-----+
147 -- | with'ed |------------------------------>| EW2 |--->
148 -- +---------+ | +-----+
150 -- +--------+ +-----+ +-----+
151 -- | Scope2 |---------------->| E12 |--------------->| E22 |--->
152 -- +--------+ +-----+ +-----+
154 -- +--------+ +-----+ +-----+
155 -- | Scope1 |---------------->| E11 |--------------->| E12 |--->
156 -- +--------+ +-----+ +-----+
160 -- | | with'ed |----------------------------------------->
164 -- (innermost first) | |
165 -- +----------------------------+
166 -- Names table => | Id1 | | | | Id2 |
167 -- +----------------------------+
169 -- Name resolution must deal with several syntactic forms: simple names,
170 -- qualified names, indexed names, and various forms of calls.
172 -- Each identifier points to an entry in the names table. The resolution
173 -- of a simple name consists in traversing the homonym chain, starting
174 -- from the names table. If an entry is immediately visible, it is the one
175 -- designated by the identifier. If only potentially use-visible entities
176 -- are on the chain, we must verify that they do not hide each other. If
177 -- the entity we find is overloadable, we collect all other overloadable
178 -- entities on the chain as long as they are not hidden.
180 -- To resolve expanded names, we must find the entity at the intersection
181 -- of the entity chain for the scope (the prefix) and the homonym chain
182 -- for the selector. In general, homonym chains will be much shorter than
183 -- entity chains, so it is preferable to start from the names table as
184 -- well. If the entity found is overloadable, we must collect all other
185 -- interpretations that are defined in the scope denoted by the prefix.
187 -- For records, protected types, and tasks, their local entities are
188 -- removed from visibility chains on exit from the corresponding scope.
189 -- From the outside, these entities are always accessed by selected
190 -- notation, and the entity chain for the record type, protected type,
191 -- etc. is traversed sequentially in order to find the designated entity.
193 -- The discriminants of a type and the operations of a protected type or
194 -- task are unchained on exit from the first view of the type, (such as
195 -- a private or incomplete type declaration, or a protected type speci-
196 -- fication) and re-chained when compiling the second view.
198 -- In the case of operators, we do not make operators on derived types
199 -- explicit. As a result, the notation P."+" may denote either a user-
200 -- defined function with name "+", or else an implicit declaration of the
201 -- operator "+" in package P. The resolution of expanded names always
202 -- tries to resolve an operator name as such an implicitly defined entity,
203 -- in addition to looking for explicit declarations.
205 -- All forms of names that denote entities (simple names, expanded names,
206 -- character literals in some cases) have a Entity attribute, which
207 -- identifies the entity denoted by the name.
209 ---------------------
210 -- The Scope Stack --
211 ---------------------
213 -- The Scope stack keeps track of the scopes currently been compiled.
214 -- Every entity that contains declarations (including records) is placed
215 -- on the scope stack while it is being processed, and removed at the end.
216 -- Whenever a non-package scope is exited, the entities defined therein
217 -- are removed from the visibility table, so that entities in outer scopes
218 -- become visible (see previous description). On entry to Sem, the scope
219 -- stack only contains the package Standard. As usual, subunits complicate
220 -- this picture ever so slightly.
222 -- The Rtsfind mechanism can force a call to Semantics while another
223 -- compilation is in progress. The unit retrieved by Rtsfind must be
224 -- compiled in its own context, and has no access to the visibility of
225 -- the unit currently being compiled. The procedures Save_Scope_Stack and
226 -- Restore_Scope_Stack make entities in current open scopes invisible
227 -- before compiling the retrieved unit, and restore the compilation
228 -- environment afterwards.
230 ------------------------
231 -- Compiling subunits --
232 ------------------------
234 -- Subunits must be compiled in the environment of the corresponding stub,
235 -- that is to say with the same visibility into the parent (and its
236 -- context) that is available at the point of the stub declaration, but
237 -- with the additional visibility provided by the context clause of the
238 -- subunit itself. As a result, compilation of a subunit forces compilation
239 -- of the parent (see description in lib-). At the point of the stub
240 -- declaration, Analyze is called recursively to compile the proper body of
241 -- the subunit, but without reinitializing the names table, nor the scope
242 -- stack (i.e. standard is not pushed on the stack). In this fashion the
243 -- context of the subunit is added to the context of the parent, and the
244 -- subunit is compiled in the correct environment. Note that in the course
245 -- of processing the context of a subunit, Standard will appear twice on
246 -- the scope stack: once for the parent of the subunit, and once for the
247 -- unit in the context clause being compiled. However, the two sets of
248 -- entities are not linked by homonym chains, so that the compilation of
249 -- any context unit happens in a fresh visibility environment.
251 -------------------------------
252 -- Processing of USE Clauses --
253 -------------------------------
255 -- Every defining occurrence has a flag indicating if it is potentially use
256 -- visible. Resolution of simple names examines this flag. The processing
257 -- of use clauses consists in setting this flag on all visible entities
258 -- defined in the corresponding package. On exit from the scope of the use
259 -- clause, the corresponding flag must be reset. However, a package may
260 -- appear in several nested use clauses (pathological but legal, alas!)
261 -- which forces us to use a slightly more involved scheme:
263 -- a) The defining occurrence for a package holds a flag -In_Use- to
264 -- indicate that it is currently in the scope of a use clause. If a
265 -- redundant use clause is encountered, then the corresponding occurrence
266 -- of the package name is flagged -Redundant_Use-.
268 -- b) On exit from a scope, the use clauses in its declarative part are
269 -- scanned. The visibility flag is reset in all entities declared in
270 -- package named in a use clause, as long as the package is not flagged
271 -- as being in a redundant use clause (in which case the outer use
272 -- clause is still in effect, and the direct visibility of its entities
273 -- must be retained).
275 -- Note that entities are not removed from their homonym chains on exit
276 -- from the package specification. A subsequent use clause does not need
277 -- to rechain the visible entities, but only to establish their direct
280 -----------------------------------
281 -- Handling private declarations --
282 -----------------------------------
284 -- The principle that each entity has a single defining occurrence clashes
285 -- with the presence of two separate definitions for private types: the
286 -- first is the private type declaration, and second is the full type
287 -- declaration. It is important that all references to the type point to
288 -- the same defining occurrence, namely the first one. To enforce the two
289 -- separate views of the entity, the corresponding information is swapped
290 -- between the two declarations. Outside of the package, the defining
291 -- occurrence only contains the private declaration information, while in
292 -- the private part and the body of the package the defining occurrence
293 -- contains the full declaration. To simplify the swap, the defining
294 -- occurrence that currently holds the private declaration points to the
295 -- full declaration. During semantic processing the defining occurrence
296 -- also points to a list of private dependents, that is to say access types
297 -- or composite types whose designated types or component types are
298 -- subtypes or derived types of the private type in question. After the
299 -- full declaration has been seen, the private dependents are updated to
300 -- indicate that they have full definitions.
302 ------------------------------------
303 -- Handling of Undefined Messages --
304 ------------------------------------
306 -- In normal mode, only the first use of an undefined identifier generates
307 -- a message. The table Urefs is used to record error messages that have
308 -- been issued so that second and subsequent ones do not generate further
309 -- messages. However, the second reference causes text to be added to the
310 -- original undefined message noting "(more references follow)". The
311 -- full error list option (-gnatf) forces messages to be generated for
312 -- every reference and disconnects the use of this table.
314 type Uref_Entry is record
316 -- Node for identifier for which original message was posted. The
317 -- Chars field of this identifier is used to detect later references
318 -- to the same identifier.
321 -- Records error message Id of original undefined message. Reset to
322 -- No_Error_Msg after the second occurrence, where it is used to add
323 -- text to the original message as described above.
326 -- Set if the message is not visible rather than undefined
329 -- Records location of error message. Used to make sure that we do
330 -- not consider a, b : undefined as two separate instances, which
331 -- would otherwise happen, since the parser converts this sequence
332 -- to a : undefined; b : undefined.
336 package Urefs is new Table.Table (
337 Table_Component_Type => Uref_Entry,
338 Table_Index_Type => Nat,
339 Table_Low_Bound => 1,
341 Table_Increment => 100,
342 Table_Name => "Urefs");
344 Candidate_Renaming : Entity_Id;
345 -- Holds a candidate interpretation that appears in a subprogram renaming
346 -- declaration and does not match the given specification, but matches at
347 -- least on the first formal. Allows better error message when given
348 -- specification omits defaulted parameters, a common error.
350 -----------------------
351 -- Local Subprograms --
352 -----------------------
354 procedure Analyze_Generic_Renaming
357 -- Common processing for all three kinds of generic renaming declarations.
358 -- Enter new name and indicate that it renames the generic unit.
360 procedure Analyze_Renamed_Character
364 -- Renamed entity is given by a character literal, which must belong
365 -- to the return type of the new entity. Is_Body indicates whether the
366 -- declaration is a renaming_as_body. If the original declaration has
367 -- already been frozen (because of an intervening body, e.g.) the body of
368 -- the function must be built now. The same applies to the following
369 -- various renaming procedures.
371 procedure Analyze_Renamed_Dereference
375 -- Renamed entity is given by an explicit dereference. Prefix must be a
376 -- conformant access_to_subprogram type.
378 procedure Analyze_Renamed_Entry
382 -- If the renamed entity in a subprogram renaming is an entry or protected
383 -- subprogram, build a body for the new entity whose only statement is a
384 -- call to the renamed entity.
386 procedure Analyze_Renamed_Family_Member
390 -- Used when the renamed entity is an indexed component. The prefix must
391 -- denote an entry family.
393 procedure Analyze_Renamed_Primitive_Operation
397 -- If the renamed entity in a subprogram renaming is a primitive operation
398 -- or a class-wide operation in prefix form, save the target object, which
399 -- must be added to the list of actuals in any subsequent call.
401 function Applicable_Use (Pack_Name : Node_Id) return Boolean;
402 -- Common code to Use_One_Package and Set_Use, to determine whether use
403 -- clause must be processed. Pack_Name is an entity name that references
404 -- the package in question.
406 procedure Attribute_Renaming (N : Node_Id);
407 -- Analyze renaming of attribute as subprogram. The renaming declaration N
408 -- is rewritten as a subprogram body that returns the attribute reference
409 -- applied to the formals of the function.
411 procedure Set_Entity_Or_Discriminal (N : Node_Id; E : Entity_Id);
412 -- Set Entity, with style check if need be. For a discriminant reference,
413 -- replace by the corresponding discriminal, i.e. the parameter of the
414 -- initialization procedure that corresponds to the discriminant.
416 procedure Check_Frozen_Renaming (N : Node_Id; Subp : Entity_Id);
417 -- A renaming_as_body may occur after the entity of the original decla-
418 -- ration has been frozen. In that case, the body of the new entity must
419 -- be built now, because the usual mechanism of building the renamed
420 -- body at the point of freezing will not work. Subp is the subprogram
421 -- for which N provides the Renaming_As_Body.
423 procedure Check_In_Previous_With_Clause
426 -- N is a use_package clause and Nam the package name, or N is a use_type
427 -- clause and Nam is the prefix of the type name. In either case, verify
428 -- that the package is visible at that point in the context: either it
429 -- appears in a previous with_clause, or because it is a fully qualified
430 -- name and the root ancestor appears in a previous with_clause.
432 procedure Check_Library_Unit_Renaming (N : Node_Id; Old_E : Entity_Id);
433 -- Verify that the entity in a renaming declaration that is a library unit
434 -- is itself a library unit and not a nested unit or subunit. Also check
435 -- that if the renaming is a child unit of a generic parent, then the
436 -- renamed unit must also be a child unit of that parent. Finally, verify
437 -- that a renamed generic unit is not an implicit child declared within
438 -- an instance of the parent.
440 procedure Chain_Use_Clause (N : Node_Id);
441 -- Chain use clause onto list of uses clauses headed by First_Use_Clause in
442 -- the proper scope table entry. This is usually the current scope, but it
443 -- will be an inner scope when installing the use clauses of the private
444 -- declarations of a parent unit prior to compiling the private part of a
445 -- child unit. This chain is traversed when installing/removing use clauses
446 -- when compiling a subunit or instantiating a generic body on the fly,
447 -- when it is necessary to save and restore full environments.
449 function Has_Implicit_Character_Literal (N : Node_Id) return Boolean;
450 -- Find a type derived from Character or Wide_Character in the prefix of N.
451 -- Used to resolved qualified names whose selector is a character literal.
453 function Has_Private_With (E : Entity_Id) return Boolean;
454 -- Ada 2005 (AI-262): Determines if the current compilation unit has a
455 -- private with on E.
457 procedure Find_Expanded_Name (N : Node_Id);
458 -- The input is a selected component known to be an expanded name. Verify
459 -- legality of selector given the scope denoted by prefix, and change node
460 -- N into a expanded name with a properly set Entity field.
462 function Find_Renamed_Entity
466 Is_Actual : Boolean := False) return Entity_Id;
467 -- Find the renamed entity that corresponds to the given parameter profile
468 -- in a subprogram renaming declaration. The renamed entity may be an
469 -- operator, a subprogram, an entry, or a protected operation. Is_Actual
470 -- indicates that the renaming is the one generated for an actual subpro-
471 -- gram in an instance, for which special visibility checks apply.
473 function Has_Implicit_Operator (N : Node_Id) return Boolean;
474 -- N is an expanded name whose selector is an operator name (e.g. P."+").
475 -- declarative part contains an implicit declaration of an operator if it
476 -- has a declaration of a type to which one of the predefined operators
477 -- apply. The existence of this routine is an implementation artifact. A
478 -- more straightforward but more space-consuming choice would be to make
479 -- all inherited operators explicit in the symbol table.
481 procedure Inherit_Renamed_Profile (New_S : Entity_Id; Old_S : Entity_Id);
482 -- A subprogram defined by a renaming declaration inherits the parameter
483 -- profile of the renamed entity. The subtypes given in the subprogram
484 -- specification are discarded and replaced with those of the renamed
485 -- subprogram, which are then used to recheck the default values.
487 function Is_Appropriate_For_Record (T : Entity_Id) return Boolean;
488 -- Prefix is appropriate for record if it is of a record type, or an access
491 function Is_Appropriate_For_Entry_Prefix (T : Entity_Id) return Boolean;
492 -- True if it is of a task type, a protected type, or else an access to one
495 procedure Note_Redundant_Use (Clause : Node_Id);
496 -- Mark the name in a use clause as redundant if the corresponding entity
497 -- is already use-visible. Emit a warning if the use clause comes from
498 -- source and the proper warnings are enabled.
500 procedure Premature_Usage (N : Node_Id);
501 -- Diagnose usage of an entity before it is visible
503 procedure Use_One_Package (P : Entity_Id; N : Node_Id);
504 -- Make visible entities declared in package P potentially use-visible
505 -- in the current context. Also used in the analysis of subunits, when
506 -- re-installing use clauses of parent units. N is the use_clause that
507 -- names P (and possibly other packages).
509 procedure Use_One_Type (Id : Node_Id);
510 -- Id is the subtype mark from a use type clause. This procedure makes
511 -- the primitive operators of the type potentially use-visible.
513 procedure Write_Info;
514 -- Write debugging information on entities declared in current scope
516 --------------------------------
517 -- Analyze_Exception_Renaming --
518 --------------------------------
520 -- The language only allows a single identifier, but the tree holds an
521 -- identifier list. The parser has already issued an error message if
522 -- there is more than one element in the list.
524 procedure Analyze_Exception_Renaming (N : Node_Id) is
525 Id : constant Node_Id := Defining_Identifier (N);
526 Nam : constant Node_Id := Name (N);
529 -- Exception renaming is not allowed in SPARK or ALFA
531 if Formal_Verification_Mode then
532 Error_Msg_F ("|~~exception renaming is not allowed", N);
535 -- Proceed with analysis
540 Set_Ekind (Id, E_Exception);
541 Set_Exception_Code (Id, Uint_0);
542 Set_Etype (Id, Standard_Exception_Type);
543 Set_Is_Pure (Id, Is_Pure (Current_Scope));
545 if not Is_Entity_Name (Nam) or else
546 Ekind (Entity (Nam)) /= E_Exception
548 Error_Msg_N ("invalid exception name in renaming", Nam);
550 if Present (Renamed_Object (Entity (Nam))) then
551 Set_Renamed_Object (Id, Renamed_Object (Entity (Nam)));
553 Set_Renamed_Object (Id, Entity (Nam));
556 end Analyze_Exception_Renaming;
558 ---------------------------
559 -- Analyze_Expanded_Name --
560 ---------------------------
562 procedure Analyze_Expanded_Name (N : Node_Id) is
564 -- If the entity pointer is already set, this is an internal node, or a
565 -- node that is analyzed more than once, after a tree modification. In
566 -- such a case there is no resolution to perform, just set the type. For
567 -- completeness, analyze prefix as well.
569 if Present (Entity (N)) then
570 if Is_Type (Entity (N)) then
571 Set_Etype (N, Entity (N));
573 Set_Etype (N, Etype (Entity (N)));
576 Analyze (Prefix (N));
579 Find_Expanded_Name (N);
581 end Analyze_Expanded_Name;
583 ---------------------------------------
584 -- Analyze_Generic_Function_Renaming --
585 ---------------------------------------
587 procedure Analyze_Generic_Function_Renaming (N : Node_Id) is
589 Analyze_Generic_Renaming (N, E_Generic_Function);
590 end Analyze_Generic_Function_Renaming;
592 --------------------------------------
593 -- Analyze_Generic_Package_Renaming --
594 --------------------------------------
596 procedure Analyze_Generic_Package_Renaming (N : Node_Id) is
598 -- Apply the Text_IO Kludge here, since we may be renaming one of the
599 -- subpackages of Text_IO, then join common routine.
601 Text_IO_Kludge (Name (N));
603 Analyze_Generic_Renaming (N, E_Generic_Package);
604 end Analyze_Generic_Package_Renaming;
606 ----------------------------------------
607 -- Analyze_Generic_Procedure_Renaming --
608 ----------------------------------------
610 procedure Analyze_Generic_Procedure_Renaming (N : Node_Id) is
612 Analyze_Generic_Renaming (N, E_Generic_Procedure);
613 end Analyze_Generic_Procedure_Renaming;
615 ------------------------------
616 -- Analyze_Generic_Renaming --
617 ------------------------------
619 procedure Analyze_Generic_Renaming
623 New_P : constant Entity_Id := Defining_Entity (N);
625 Inst : Boolean := False; -- prevent junk warning
628 -- Generic renaming is not allowed in SPARK or ALFA
630 if Formal_Verification_Mode then
631 Error_Msg_F ("|~~generic renaming is not allowed", N);
634 -- Proceed with analysis
636 if Name (N) = Error then
640 Generate_Definition (New_P);
642 if Current_Scope /= Standard_Standard then
643 Set_Is_Pure (New_P, Is_Pure (Current_Scope));
646 if Nkind (Name (N)) = N_Selected_Component then
647 Check_Generic_Child_Unit (Name (N), Inst);
652 if not Is_Entity_Name (Name (N)) then
653 Error_Msg_N ("expect entity name in renaming declaration", Name (N));
656 Old_P := Entity (Name (N));
660 Set_Ekind (New_P, K);
662 if Etype (Old_P) = Any_Type then
665 elsif Ekind (Old_P) /= K then
666 Error_Msg_N ("invalid generic unit name", Name (N));
669 if Present (Renamed_Object (Old_P)) then
670 Set_Renamed_Object (New_P, Renamed_Object (Old_P));
672 Set_Renamed_Object (New_P, Old_P);
675 Set_Is_Pure (New_P, Is_Pure (Old_P));
676 Set_Is_Preelaborated (New_P, Is_Preelaborated (Old_P));
678 Set_Etype (New_P, Etype (Old_P));
679 Set_Has_Completion (New_P);
681 if In_Open_Scopes (Old_P) then
682 Error_Msg_N ("within its scope, generic denotes its instance", N);
685 Check_Library_Unit_Renaming (N, Old_P);
687 end Analyze_Generic_Renaming;
689 -----------------------------
690 -- Analyze_Object_Renaming --
691 -----------------------------
693 procedure Analyze_Object_Renaming (N : Node_Id) is
694 Id : constant Entity_Id := Defining_Identifier (N);
696 Nam : constant Node_Id := Name (N);
700 function In_Generic_Scope (E : Entity_Id) return Boolean;
701 -- Determine whether entity E is inside a generic cope
703 ----------------------
704 -- In_Generic_Scope --
705 ----------------------
707 function In_Generic_Scope (E : Entity_Id) return Boolean is
712 while Present (S) and then S /= Standard_Standard loop
713 if Is_Generic_Unit (S) then
721 end In_Generic_Scope;
723 -- Start of processing for Analyze_Object_Renaming
726 -- Object renaming is not allowed in SPARK or ALFA
728 if Formal_Verification_Mode then
729 Error_Msg_F ("|~~object renaming is not allowed", N);
732 -- Proceed with analysis
738 Set_Is_Pure (Id, Is_Pure (Current_Scope));
741 -- The renaming of a component that depends on a discriminant requires
742 -- an actual subtype, because in subsequent use of the object Gigi will
743 -- be unable to locate the actual bounds. This explicit step is required
744 -- when the renaming is generated in removing side effects of an
745 -- already-analyzed expression.
747 if Nkind (Nam) = N_Selected_Component
748 and then Analyzed (Nam)
751 Dec := Build_Actual_Subtype_Of_Component (Etype (Nam), Nam);
753 if Present (Dec) then
754 Insert_Action (N, Dec);
755 T := Defining_Identifier (Dec);
759 -- Complete analysis of the subtype mark in any case, for ASIS use
761 if Present (Subtype_Mark (N)) then
762 Find_Type (Subtype_Mark (N));
765 elsif Present (Subtype_Mark (N)) then
766 Find_Type (Subtype_Mark (N));
767 T := Entity (Subtype_Mark (N));
770 if Nkind (Nam) = N_Type_Conversion
771 and then not Is_Tagged_Type (T)
774 ("renaming of conversion only allowed for tagged types", Nam);
779 -- Check that a class-wide object is not being renamed as an object
780 -- of a specific type. The test for access types is needed to exclude
781 -- cases where the renamed object is a dynamically tagged access
782 -- result, such as occurs in certain expansions.
784 if Is_Tagged_Type (T) then
785 Check_Dynamically_Tagged_Expression
791 -- Ada 2005 (AI-230/AI-254): Access renaming
793 else pragma Assert (Present (Access_Definition (N)));
794 T := Access_Definition
796 N => Access_Definition (N));
800 -- Ada 2005 AI05-105: if the declaration has an anonymous access
801 -- type, the renamed object must also have an anonymous type, and
802 -- this is a name resolution rule. This was implicit in the last
803 -- part of the first sentence in 8.5.1.(3/2), and is made explicit
804 -- by this recent AI.
806 if not Is_Overloaded (Nam) then
807 if Ekind (Etype (Nam)) /= Ekind (T) then
809 ("expect anonymous access type in object renaming", N);
816 Typ : Entity_Id := Empty;
817 Seen : Boolean := False;
820 Get_First_Interp (Nam, I, It);
821 while Present (It.Typ) loop
823 -- Renaming is ambiguous if more than one candidate
824 -- interpretation is type-conformant with the context.
826 if Ekind (It.Typ) = Ekind (T) then
827 if Ekind (T) = E_Anonymous_Access_Subprogram_Type
830 (Designated_Type (T), Designated_Type (It.Typ))
836 ("ambiguous expression in renaming", Nam);
839 elsif Ekind (T) = E_Anonymous_Access_Type
841 Covers (Designated_Type (T), Designated_Type (It.Typ))
847 ("ambiguous expression in renaming", Nam);
851 if Covers (T, It.Typ) then
853 Set_Etype (Nam, Typ);
854 Set_Is_Overloaded (Nam, False);
858 Get_Next_Interp (I, It);
865 -- Ada 2005 (AI-231): "In the case where the type is defined by an
866 -- access_definition, the renamed entity shall be of an access-to-
867 -- constant type if and only if the access_definition defines an
868 -- access-to-constant type" ARM 8.5.1(4)
870 if Constant_Present (Access_Definition (N))
871 and then not Is_Access_Constant (Etype (Nam))
873 Error_Msg_N ("(Ada 2005): the renamed object is not "
874 & "access-to-constant (RM 8.5.1(6))", N);
876 elsif not Constant_Present (Access_Definition (N))
877 and then Is_Access_Constant (Etype (Nam))
879 Error_Msg_N ("(Ada 2005): the renamed object is not "
880 & "access-to-variable (RM 8.5.1(6))", N);
883 if Is_Access_Subprogram_Type (Etype (Nam)) then
884 Check_Subtype_Conformant
885 (Designated_Type (T), Designated_Type (Etype (Nam)));
887 elsif not Subtypes_Statically_Match
888 (Designated_Type (T), Designated_Type (Etype (Nam)))
891 ("subtype of renamed object does not statically match", N);
895 -- Special processing for renaming function return object. Some errors
896 -- and warnings are produced only for calls that come from source.
898 if Nkind (Nam) = N_Function_Call then
901 -- Usage is illegal in Ada 83
904 if Comes_From_Source (Nam) then
906 ("(Ada 83) cannot rename function return object", Nam);
909 -- In Ada 95, warn for odd case of renaming parameterless function
910 -- call if this is not a limited type (where this is useful).
913 if Warn_On_Object_Renames_Function
914 and then No (Parameter_Associations (Nam))
915 and then not Is_Limited_Type (Etype (Nam))
916 and then Comes_From_Source (Nam)
919 ("?renaming function result object is suspicious", Nam);
921 ("\?function & will be called only once", Nam,
922 Entity (Name (Nam)));
923 Error_Msg_N -- CODEFIX
924 ("\?suggest using an initialized constant object instead",
928 -- If the function call returns an unconstrained type, we must
929 -- build a constrained subtype for the new entity, in a way
930 -- similar to what is done for an object declaration with an
931 -- unconstrained nominal type.
933 if Is_Composite_Type (Etype (Nam))
934 and then not Is_Constrained (Etype (Nam))
935 and then not Has_Unknown_Discriminants (Etype (Nam))
936 and then Expander_Active
939 Loc : constant Source_Ptr := Sloc (N);
940 Subt : constant Entity_Id := Make_Temporary (Loc, 'T');
942 Remove_Side_Effects (Nam);
944 Make_Subtype_Declaration (Loc,
945 Defining_Identifier => Subt,
946 Subtype_Indication =>
947 Make_Subtype_From_Expr (Nam, Etype (Nam))));
948 Rewrite (Subtype_Mark (N), New_Occurrence_Of (Subt, Loc));
949 Set_Etype (Nam, Subt);
955 -- An object renaming requires an exact match of the type. Class-wide
956 -- matching is not allowed.
958 if Is_Class_Wide_Type (T)
959 and then Base_Type (Etype (Nam)) /= Base_Type (T)
966 -- (Ada 2005: AI-326): Handle wrong use of incomplete type
968 if Nkind (Nam) = N_Explicit_Dereference
969 and then Ekind (Etype (T2)) = E_Incomplete_Type
971 Error_Msg_NE ("invalid use of incomplete type&", Id, T2);
974 elsif Ekind (Etype (T)) = E_Incomplete_Type then
975 Error_Msg_NE ("invalid use of incomplete type&", Id, T);
981 if Ada_Version >= Ada_2005
982 and then Nkind (Nam) = N_Attribute_Reference
983 and then Attribute_Name (Nam) = Name_Priority
987 elsif Ada_Version >= Ada_2005
988 and then Nkind (Nam) in N_Has_Entity
995 if Nkind (Nam) = N_Attribute_Reference then
996 Nam_Ent := Entity (Prefix (Nam));
998 Nam_Ent := Entity (Nam);
1001 Nam_Decl := Parent (Nam_Ent);
1003 if Has_Null_Exclusion (N)
1004 and then not Has_Null_Exclusion (Nam_Decl)
1006 -- Ada 2005 (AI-423): If the object name denotes a generic
1007 -- formal object of a generic unit G, and the object renaming
1008 -- declaration occurs within the body of G or within the body
1009 -- of a generic unit declared within the declarative region
1010 -- of G, then the declaration of the formal object of G must
1011 -- have a null exclusion or a null-excluding subtype.
1013 if Is_Formal_Object (Nam_Ent)
1014 and then In_Generic_Scope (Id)
1016 if not Can_Never_Be_Null (Etype (Nam_Ent)) then
1018 ("renamed formal does not exclude `NULL` "
1019 & "(RM 8.5.1(4.6/2))", N);
1021 elsif In_Package_Body (Scope (Id)) then
1023 ("formal object does not have a null exclusion"
1024 & "(RM 8.5.1(4.6/2))", N);
1027 -- Ada 2005 (AI-423): Otherwise, the subtype of the object name
1028 -- shall exclude null.
1030 elsif not Can_Never_Be_Null (Etype (Nam_Ent)) then
1032 ("renamed object does not exclude `NULL` "
1033 & "(RM 8.5.1(4.6/2))", N);
1035 -- An instance is illegal if it contains a renaming that
1036 -- excludes null, and the actual does not. The renaming
1037 -- declaration has already indicated that the declaration
1038 -- of the renamed actual in the instance will raise
1039 -- constraint_error.
1041 elsif Nkind (Nam_Decl) = N_Object_Declaration
1042 and then In_Instance
1044 (Corresponding_Generic_Association (Nam_Decl))
1045 and then Nkind (Expression (Nam_Decl))
1046 = N_Raise_Constraint_Error
1049 ("renamed actual does not exclude `NULL` "
1050 & "(RM 8.5.1(4.6/2))", N);
1052 -- Finally, if there is a null exclusion, the subtype mark
1053 -- must not be null-excluding.
1055 elsif No (Access_Definition (N))
1056 and then Can_Never_Be_Null (T)
1059 ("`NOT NULL` not allowed (& already excludes null)",
1064 elsif Can_Never_Be_Null (T)
1065 and then not Can_Never_Be_Null (Etype (Nam_Ent))
1068 ("renamed object does not exclude `NULL` "
1069 & "(RM 8.5.1(4.6/2))", N);
1071 elsif Has_Null_Exclusion (N)
1072 and then No (Access_Definition (N))
1073 and then Can_Never_Be_Null (T)
1076 ("`NOT NULL` not allowed (& already excludes null)", N, T);
1081 Set_Ekind (Id, E_Variable);
1082 Init_Size_Align (Id);
1084 if T = Any_Type or else Etype (Nam) = Any_Type then
1087 -- Verify that the renamed entity is an object or a function call. It
1088 -- may have been rewritten in several ways.
1090 elsif Is_Object_Reference (Nam) then
1091 if Comes_From_Source (N)
1092 and then Is_Dependent_Component_Of_Mutable_Object (Nam)
1095 ("illegal renaming of discriminant-dependent component", Nam);
1098 -- A static function call may have been folded into a literal
1100 elsif Nkind (Original_Node (Nam)) = N_Function_Call
1102 -- When expansion is disabled, attribute reference is not
1103 -- rewritten as function call. Otherwise it may be rewritten
1104 -- as a conversion, so check original node.
1106 or else (Nkind (Original_Node (Nam)) = N_Attribute_Reference
1107 and then Is_Function_Attribute_Name
1108 (Attribute_Name (Original_Node (Nam))))
1110 -- Weird but legal, equivalent to renaming a function call.
1111 -- Illegal if the literal is the result of constant-folding an
1112 -- attribute reference that is not a function.
1114 or else (Is_Entity_Name (Nam)
1115 and then Ekind (Entity (Nam)) = E_Enumeration_Literal
1117 Nkind (Original_Node (Nam)) /= N_Attribute_Reference)
1119 or else (Nkind (Nam) = N_Type_Conversion
1120 and then Is_Tagged_Type (Entity (Subtype_Mark (Nam))))
1124 elsif Nkind (Nam) = N_Type_Conversion then
1126 ("renaming of conversion only allowed for tagged types", Nam);
1128 -- Ada 2005 (AI-327)
1130 elsif Ada_Version >= Ada_2005
1131 and then Nkind (Nam) = N_Attribute_Reference
1132 and then Attribute_Name (Nam) = Name_Priority
1136 -- Allow internally generated x'Reference expression
1138 elsif Nkind (Nam) = N_Reference then
1142 Error_Msg_N ("expect object name in renaming", Nam);
1147 if not Is_Variable (Nam) then
1148 Set_Ekind (Id, E_Constant);
1149 Set_Never_Set_In_Source (Id, True);
1150 Set_Is_True_Constant (Id, True);
1153 Set_Renamed_Object (Id, Nam);
1154 end Analyze_Object_Renaming;
1156 ------------------------------
1157 -- Analyze_Package_Renaming --
1158 ------------------------------
1160 procedure Analyze_Package_Renaming (N : Node_Id) is
1161 New_P : constant Entity_Id := Defining_Entity (N);
1166 if Name (N) = Error then
1170 -- Apply Text_IO kludge here since we may be renaming a child of Text_IO
1172 Text_IO_Kludge (Name (N));
1174 if Current_Scope /= Standard_Standard then
1175 Set_Is_Pure (New_P, Is_Pure (Current_Scope));
1181 if Is_Entity_Name (Name (N)) then
1182 Old_P := Entity (Name (N));
1187 if Etype (Old_P) = Any_Type then
1188 Error_Msg_N ("expect package name in renaming", Name (N));
1190 elsif Ekind (Old_P) /= E_Package
1191 and then not (Ekind (Old_P) = E_Generic_Package
1192 and then In_Open_Scopes (Old_P))
1194 if Ekind (Old_P) = E_Generic_Package then
1196 ("generic package cannot be renamed as a package", Name (N));
1198 Error_Msg_Sloc := Sloc (Old_P);
1200 ("expect package name in renaming, found& declared#",
1204 -- Set basic attributes to minimize cascaded errors
1206 Set_Ekind (New_P, E_Package);
1207 Set_Etype (New_P, Standard_Void_Type);
1209 -- Here for OK package renaming
1212 -- Entities in the old package are accessible through the renaming
1213 -- entity. The simplest implementation is to have both packages share
1216 Set_Ekind (New_P, E_Package);
1217 Set_Etype (New_P, Standard_Void_Type);
1219 if Present (Renamed_Object (Old_P)) then
1220 Set_Renamed_Object (New_P, Renamed_Object (Old_P));
1222 Set_Renamed_Object (New_P, Old_P);
1225 Set_Has_Completion (New_P);
1227 Set_First_Entity (New_P, First_Entity (Old_P));
1228 Set_Last_Entity (New_P, Last_Entity (Old_P));
1229 Set_First_Private_Entity (New_P, First_Private_Entity (Old_P));
1230 Check_Library_Unit_Renaming (N, Old_P);
1231 Generate_Reference (Old_P, Name (N));
1233 -- If the renaming is in the visible part of a package, then we set
1234 -- Renamed_In_Spec for the renamed package, to prevent giving
1235 -- warnings about no entities referenced. Such a warning would be
1236 -- overenthusiastic, since clients can see entities in the renamed
1237 -- package via the visible package renaming.
1240 Ent : constant Entity_Id := Cunit_Entity (Current_Sem_Unit);
1242 if Ekind (Ent) = E_Package
1243 and then not In_Private_Part (Ent)
1244 and then In_Extended_Main_Source_Unit (N)
1245 and then Ekind (Old_P) = E_Package
1247 Set_Renamed_In_Spec (Old_P);
1251 -- If this is the renaming declaration of a package instantiation
1252 -- within itself, it is the declaration that ends the list of actuals
1253 -- for the instantiation. At this point, the subtypes that rename
1254 -- the actuals are flagged as generic, to avoid spurious ambiguities
1255 -- if the actuals for two distinct formals happen to coincide. If
1256 -- the actual is a private type, the subtype has a private completion
1257 -- that is flagged in the same fashion.
1259 -- Resolution is identical to what is was in the original generic.
1260 -- On exit from the generic instance, these are turned into regular
1261 -- subtypes again, so they are compatible with types in their class.
1263 if not Is_Generic_Instance (Old_P) then
1266 Spec := Specification (Unit_Declaration_Node (Old_P));
1269 if Nkind (Spec) = N_Package_Specification
1270 and then Present (Generic_Parent (Spec))
1271 and then Old_P = Current_Scope
1272 and then Chars (New_P) = Chars (Generic_Parent (Spec))
1278 E := First_Entity (Old_P);
1283 and then Nkind (Parent (E)) = N_Subtype_Declaration
1285 Set_Is_Generic_Actual_Type (E);
1287 if Is_Private_Type (E)
1288 and then Present (Full_View (E))
1290 Set_Is_Generic_Actual_Type (Full_View (E));
1299 end Analyze_Package_Renaming;
1301 -------------------------------
1302 -- Analyze_Renamed_Character --
1303 -------------------------------
1305 procedure Analyze_Renamed_Character
1310 C : constant Node_Id := Name (N);
1313 if Ekind (New_S) = E_Function then
1314 Resolve (C, Etype (New_S));
1317 Check_Frozen_Renaming (N, New_S);
1321 Error_Msg_N ("character literal can only be renamed as function", N);
1323 end Analyze_Renamed_Character;
1325 ---------------------------------
1326 -- Analyze_Renamed_Dereference --
1327 ---------------------------------
1329 procedure Analyze_Renamed_Dereference
1334 Nam : constant Node_Id := Name (N);
1335 P : constant Node_Id := Prefix (Nam);
1341 if not Is_Overloaded (P) then
1342 if Ekind (Etype (Nam)) /= E_Subprogram_Type
1343 or else not Type_Conformant (Etype (Nam), New_S)
1345 Error_Msg_N ("designated type does not match specification", P);
1354 Get_First_Interp (Nam, Ind, It);
1356 while Present (It.Nam) loop
1358 if Ekind (It.Nam) = E_Subprogram_Type
1359 and then Type_Conformant (It.Nam, New_S)
1361 if Typ /= Any_Id then
1362 Error_Msg_N ("ambiguous renaming", P);
1369 Get_Next_Interp (Ind, It);
1372 if Typ = Any_Type then
1373 Error_Msg_N ("designated type does not match specification", P);
1378 Check_Frozen_Renaming (N, New_S);
1382 end Analyze_Renamed_Dereference;
1384 ---------------------------
1385 -- Analyze_Renamed_Entry --
1386 ---------------------------
1388 procedure Analyze_Renamed_Entry
1393 Nam : constant Node_Id := Name (N);
1394 Sel : constant Node_Id := Selector_Name (Nam);
1398 if Entity (Sel) = Any_Id then
1400 -- Selector is undefined on prefix. Error emitted already
1402 Set_Has_Completion (New_S);
1406 -- Otherwise find renamed entity and build body of New_S as a call to it
1408 Old_S := Find_Renamed_Entity (N, Selector_Name (Nam), New_S);
1410 if Old_S = Any_Id then
1411 Error_Msg_N (" no subprogram or entry matches specification", N);
1414 Check_Subtype_Conformant (New_S, Old_S, N);
1415 Generate_Reference (New_S, Defining_Entity (N), 'b');
1416 Style.Check_Identifier (Defining_Entity (N), New_S);
1419 -- Only mode conformance required for a renaming_as_declaration
1421 Check_Mode_Conformant (New_S, Old_S, N);
1424 Inherit_Renamed_Profile (New_S, Old_S);
1426 -- The prefix can be an arbitrary expression that yields a task type,
1427 -- so it must be resolved.
1429 Resolve (Prefix (Nam), Scope (Old_S));
1432 Set_Convention (New_S, Convention (Old_S));
1433 Set_Has_Completion (New_S, Inside_A_Generic);
1436 Check_Frozen_Renaming (N, New_S);
1438 end Analyze_Renamed_Entry;
1440 -----------------------------------
1441 -- Analyze_Renamed_Family_Member --
1442 -----------------------------------
1444 procedure Analyze_Renamed_Family_Member
1449 Nam : constant Node_Id := Name (N);
1450 P : constant Node_Id := Prefix (Nam);
1454 if (Is_Entity_Name (P) and then Ekind (Entity (P)) = E_Entry_Family)
1455 or else (Nkind (P) = N_Selected_Component
1457 Ekind (Entity (Selector_Name (P))) = E_Entry_Family)
1459 if Is_Entity_Name (P) then
1460 Old_S := Entity (P);
1462 Old_S := Entity (Selector_Name (P));
1465 if not Entity_Matches_Spec (Old_S, New_S) then
1466 Error_Msg_N ("entry family does not match specification", N);
1469 Check_Subtype_Conformant (New_S, Old_S, N);
1470 Generate_Reference (New_S, Defining_Entity (N), 'b');
1471 Style.Check_Identifier (Defining_Entity (N), New_S);
1475 Error_Msg_N ("no entry family matches specification", N);
1478 Set_Has_Completion (New_S, Inside_A_Generic);
1481 Check_Frozen_Renaming (N, New_S);
1483 end Analyze_Renamed_Family_Member;
1485 -----------------------------------------
1486 -- Analyze_Renamed_Primitive_Operation --
1487 -----------------------------------------
1489 procedure Analyze_Renamed_Primitive_Operation
1498 Ctyp : Conformance_Type) return Boolean;
1499 -- Verify that the signatures of the renamed entity and the new entity
1500 -- match. The first formal of the renamed entity is skipped because it
1501 -- is the target object in any subsequent call.
1505 Ctyp : Conformance_Type) return Boolean
1511 if Ekind (Subp) /= Ekind (New_S) then
1515 Old_F := Next_Formal (First_Formal (Subp));
1516 New_F := First_Formal (New_S);
1517 while Present (Old_F) and then Present (New_F) loop
1518 if not Conforming_Types (Etype (Old_F), Etype (New_F), Ctyp) then
1522 if Ctyp >= Mode_Conformant
1523 and then Ekind (Old_F) /= Ekind (New_F)
1528 Next_Formal (New_F);
1529 Next_Formal (Old_F);
1536 if not Is_Overloaded (Selector_Name (Name (N))) then
1537 Old_S := Entity (Selector_Name (Name (N)));
1539 if not Conforms (Old_S, Type_Conformant) then
1544 -- Find the operation that matches the given signature
1552 Get_First_Interp (Selector_Name (Name (N)), Ind, It);
1554 while Present (It.Nam) loop
1555 if Conforms (It.Nam, Type_Conformant) then
1559 Get_Next_Interp (Ind, It);
1564 if Old_S = Any_Id then
1565 Error_Msg_N (" no subprogram or entry matches specification", N);
1569 if not Conforms (Old_S, Subtype_Conformant) then
1570 Error_Msg_N ("subtype conformance error in renaming", N);
1573 Generate_Reference (New_S, Defining_Entity (N), 'b');
1574 Style.Check_Identifier (Defining_Entity (N), New_S);
1577 -- Only mode conformance required for a renaming_as_declaration
1579 if not Conforms (Old_S, Mode_Conformant) then
1580 Error_Msg_N ("mode conformance error in renaming", N);
1584 -- Inherit_Renamed_Profile (New_S, Old_S);
1586 -- The prefix can be an arbitrary expression that yields an
1587 -- object, so it must be resolved.
1589 Resolve (Prefix (Name (N)));
1591 end Analyze_Renamed_Primitive_Operation;
1593 ---------------------------------
1594 -- Analyze_Subprogram_Renaming --
1595 ---------------------------------
1597 procedure Analyze_Subprogram_Renaming (N : Node_Id) is
1598 Formal_Spec : constant Node_Id := Corresponding_Formal_Spec (N);
1599 Is_Actual : constant Boolean := Present (Formal_Spec);
1600 Inst_Node : Node_Id := Empty;
1601 Nam : constant Node_Id := Name (N);
1603 Old_S : Entity_Id := Empty;
1604 Rename_Spec : Entity_Id;
1605 Save_AV : constant Ada_Version_Type := Ada_Version;
1606 Save_AV_Exp : constant Ada_Version_Type := Ada_Version_Explicit;
1607 Spec : constant Node_Id := Specification (N);
1609 procedure Check_Null_Exclusion
1612 -- Ada 2005 (AI-423): Given renaming Ren of subprogram Sub, check the
1613 -- following AI rules:
1615 -- If Ren is a renaming of a formal subprogram and one of its
1616 -- parameters has a null exclusion, then the corresponding formal
1617 -- in Sub must also have one. Otherwise the subtype of the Sub's
1618 -- formal parameter must exclude null.
1620 -- If Ren is a renaming of a formal function and its return
1621 -- profile has a null exclusion, then Sub's return profile must
1622 -- have one. Otherwise the subtype of Sub's return profile must
1625 function Original_Subprogram (Subp : Entity_Id) return Entity_Id;
1626 -- Find renamed entity when the declaration is a renaming_as_body and
1627 -- the renamed entity may itself be a renaming_as_body. Used to enforce
1628 -- rule that a renaming_as_body is illegal if the declaration occurs
1629 -- before the subprogram it completes is frozen, and renaming indirectly
1630 -- renames the subprogram itself.(Defect Report 8652/0027).
1632 --------------------------
1633 -- Check_Null_Exclusion --
1634 --------------------------
1636 procedure Check_Null_Exclusion
1640 Ren_Formal : Entity_Id;
1641 Sub_Formal : Entity_Id;
1646 Ren_Formal := First_Formal (Ren);
1647 Sub_Formal := First_Formal (Sub);
1648 while Present (Ren_Formal)
1649 and then Present (Sub_Formal)
1651 if Has_Null_Exclusion (Parent (Ren_Formal))
1653 not (Has_Null_Exclusion (Parent (Sub_Formal))
1654 or else Can_Never_Be_Null (Etype (Sub_Formal)))
1657 ("`NOT NULL` required for parameter &",
1658 Parent (Sub_Formal), Sub_Formal);
1661 Next_Formal (Ren_Formal);
1662 Next_Formal (Sub_Formal);
1665 -- Return profile check
1667 if Nkind (Parent (Ren)) = N_Function_Specification
1668 and then Nkind (Parent (Sub)) = N_Function_Specification
1669 and then Has_Null_Exclusion (Parent (Ren))
1671 not (Has_Null_Exclusion (Parent (Sub))
1672 or else Can_Never_Be_Null (Etype (Sub)))
1675 ("return must specify `NOT NULL`",
1676 Result_Definition (Parent (Sub)));
1678 end Check_Null_Exclusion;
1680 -------------------------
1681 -- Original_Subprogram --
1682 -------------------------
1684 function Original_Subprogram (Subp : Entity_Id) return Entity_Id is
1685 Orig_Decl : Node_Id;
1686 Orig_Subp : Entity_Id;
1689 -- First case: renamed entity is itself a renaming
1691 if Present (Alias (Subp)) then
1692 return Alias (Subp);
1695 Nkind (Unit_Declaration_Node (Subp)) = N_Subprogram_Declaration
1697 (Corresponding_Body (Unit_Declaration_Node (Subp)))
1699 -- Check if renamed entity is a renaming_as_body
1702 Unit_Declaration_Node
1703 (Corresponding_Body (Unit_Declaration_Node (Subp)));
1705 if Nkind (Orig_Decl) = N_Subprogram_Renaming_Declaration then
1706 Orig_Subp := Entity (Name (Orig_Decl));
1708 if Orig_Subp = Rename_Spec then
1710 -- Circularity detected
1715 return (Original_Subprogram (Orig_Subp));
1723 end Original_Subprogram;
1725 -- Start of processing for Analyze_Subprogram_Renaming
1728 -- We must test for the attribute renaming case before the Analyze
1729 -- call because otherwise Sem_Attr will complain that the attribute
1730 -- is missing an argument when it is analyzed.
1732 if Nkind (Nam) = N_Attribute_Reference then
1734 -- In the case of an abstract formal subprogram association, rewrite
1735 -- an actual given by a stream attribute as the name of the
1736 -- corresponding stream primitive of the type.
1738 -- In a generic context the stream operations are not generated, and
1739 -- this must be treated as a normal attribute reference, to be
1740 -- expanded in subsequent instantiations.
1742 if Is_Actual and then Is_Abstract_Subprogram (Formal_Spec)
1743 and then Expander_Active
1746 Stream_Prim : Entity_Id;
1747 Prefix_Type : constant Entity_Id := Entity (Prefix (Nam));
1750 -- The class-wide forms of the stream attributes are not
1751 -- primitive dispatching operations (even though they
1752 -- internally dispatch to a stream attribute).
1754 if Is_Class_Wide_Type (Prefix_Type) then
1756 ("attribute must be a primitive dispatching operation",
1761 -- Retrieve the primitive subprogram associated with the
1762 -- attribute. This can only be a stream attribute, since those
1763 -- are the only ones that are dispatching (and the actual for
1764 -- an abstract formal subprogram must be dispatching
1768 case Attribute_Name (Nam) is
1771 Find_Prim_Op (Prefix_Type, TSS_Stream_Input);
1774 Find_Prim_Op (Prefix_Type, TSS_Stream_Output);
1777 Find_Prim_Op (Prefix_Type, TSS_Stream_Read);
1780 Find_Prim_Op (Prefix_Type, TSS_Stream_Write);
1783 ("attribute must be a primitive"
1784 & " dispatching operation", Nam);
1790 -- If no operation was found, and the type is limited,
1791 -- the user should have defined one.
1793 when Program_Error =>
1794 if Is_Limited_Type (Prefix_Type) then
1796 ("stream operation not defined for type&",
1800 -- Otherwise, compiler should have generated default
1807 -- Rewrite the attribute into the name of its corresponding
1808 -- primitive dispatching subprogram. We can then proceed with
1809 -- the usual processing for subprogram renamings.
1812 Prim_Name : constant Node_Id :=
1813 Make_Identifier (Sloc (Nam),
1814 Chars => Chars (Stream_Prim));
1816 Set_Entity (Prim_Name, Stream_Prim);
1817 Rewrite (Nam, Prim_Name);
1822 -- Normal processing for a renaming of an attribute
1825 Attribute_Renaming (N);
1830 -- Check whether this declaration corresponds to the instantiation
1831 -- of a formal subprogram.
1833 -- If this is an instantiation, the corresponding actual is frozen and
1834 -- error messages can be made more precise. If this is a default
1835 -- subprogram, the entity is already established in the generic, and is
1836 -- not retrieved by visibility. If it is a default with a box, the
1837 -- candidate interpretations, if any, have been collected when building
1838 -- the renaming declaration. If overloaded, the proper interpretation is
1839 -- determined in Find_Renamed_Entity. If the entity is an operator,
1840 -- Find_Renamed_Entity applies additional visibility checks.
1843 Inst_Node := Unit_Declaration_Node (Formal_Spec);
1845 if Is_Entity_Name (Nam)
1846 and then Present (Entity (Nam))
1847 and then not Comes_From_Source (Nam)
1848 and then not Is_Overloaded (Nam)
1850 Old_S := Entity (Nam);
1851 New_S := Analyze_Subprogram_Specification (Spec);
1855 if Ekind (Entity (Nam)) = E_Operator then
1859 if Box_Present (Inst_Node) then
1860 Old_S := Find_Renamed_Entity (N, Name (N), New_S, Is_Actual);
1862 -- If there is an immediately visible homonym of the operator
1863 -- and the declaration has a default, this is worth a warning
1864 -- because the user probably did not intend to get the pre-
1865 -- defined operator, visible in the generic declaration. To
1866 -- find if there is an intended candidate, analyze the renaming
1867 -- again in the current context.
1869 elsif Scope (Old_S) = Standard_Standard
1870 and then Present (Default_Name (Inst_Node))
1873 Decl : constant Node_Id := New_Copy_Tree (N);
1877 Set_Entity (Name (Decl), Empty);
1878 Analyze (Name (Decl));
1880 Find_Renamed_Entity (Decl, Name (Decl), New_S, True);
1883 and then In_Open_Scopes (Scope (Hidden))
1884 and then Is_Immediately_Visible (Hidden)
1885 and then Comes_From_Source (Hidden)
1886 and then Hidden /= Old_S
1888 Error_Msg_Sloc := Sloc (Hidden);
1889 Error_Msg_N ("?default subprogram is resolved " &
1890 "in the generic declaration " &
1891 "(RM 12.6(17))", N);
1892 Error_Msg_NE ("\?and will not use & #", N, Hidden);
1900 New_S := Analyze_Subprogram_Specification (Spec);
1904 -- Renamed entity must be analyzed first, to avoid being hidden by
1905 -- new name (which might be the same in a generic instance).
1909 -- The renaming defines a new overloaded entity, which is analyzed
1910 -- like a subprogram declaration.
1912 New_S := Analyze_Subprogram_Specification (Spec);
1915 if Current_Scope /= Standard_Standard then
1916 Set_Is_Pure (New_S, Is_Pure (Current_Scope));
1919 Rename_Spec := Find_Corresponding_Spec (N);
1921 -- Case of Renaming_As_Body
1923 if Present (Rename_Spec) then
1925 -- Renaming declaration is the completion of the declaration of
1926 -- Rename_Spec. We build an actual body for it at the freezing point.
1928 Set_Corresponding_Spec (N, Rename_Spec);
1930 -- Deal with special case of stream functions of abstract types
1933 if Nkind (Unit_Declaration_Node (Rename_Spec)) =
1934 N_Abstract_Subprogram_Declaration
1936 -- Input stream functions are abstract if the object type is
1937 -- abstract. Similarly, all default stream functions for an
1938 -- interface type are abstract. However, these subprograms may
1939 -- receive explicit declarations in representation clauses, making
1940 -- the attribute subprograms usable as defaults in subsequent
1942 -- In this case we rewrite the declaration to make the subprogram
1943 -- non-abstract. We remove the previous declaration, and insert
1944 -- the new one at the point of the renaming, to prevent premature
1945 -- access to unfrozen types. The new declaration reuses the
1946 -- specification of the previous one, and must not be analyzed.
1949 (Is_Primitive (Entity (Nam))
1951 Is_Abstract_Type (Find_Dispatching_Type (Entity (Nam))));
1953 Old_Decl : constant Node_Id :=
1954 Unit_Declaration_Node (Rename_Spec);
1955 New_Decl : constant Node_Id :=
1956 Make_Subprogram_Declaration (Sloc (N),
1958 Relocate_Node (Specification (Old_Decl)));
1961 Insert_After (N, New_Decl);
1962 Set_Is_Abstract_Subprogram (Rename_Spec, False);
1963 Set_Analyzed (New_Decl);
1967 Set_Corresponding_Body (Unit_Declaration_Node (Rename_Spec), New_S);
1969 if Ada_Version = Ada_83 and then Comes_From_Source (N) then
1970 Error_Msg_N ("(Ada 83) renaming cannot serve as a body", N);
1973 Set_Convention (New_S, Convention (Rename_Spec));
1974 Check_Fully_Conformant (New_S, Rename_Spec);
1975 Set_Public_Status (New_S);
1977 -- The specification does not introduce new formals, but only
1978 -- repeats the formals of the original subprogram declaration.
1979 -- For cross-reference purposes, and for refactoring tools, we
1980 -- treat the formals of the renaming declaration as body formals.
1982 Reference_Body_Formals (Rename_Spec, New_S);
1984 -- Indicate that the entity in the declaration functions like the
1985 -- corresponding body, and is not a new entity. The body will be
1986 -- constructed later at the freeze point, so indicate that the
1987 -- completion has not been seen yet.
1989 Set_Ekind (New_S, E_Subprogram_Body);
1990 New_S := Rename_Spec;
1991 Set_Has_Completion (Rename_Spec, False);
1993 -- Ada 2005: check overriding indicator
1995 if Present (Overridden_Operation (Rename_Spec)) then
1996 if Must_Not_Override (Specification (N)) then
1998 ("subprogram& overrides inherited operation",
2001 Style_Check and then not Must_Override (Specification (N))
2003 Style.Missing_Overriding (N, Rename_Spec);
2006 elsif Must_Override (Specification (N)) then
2007 Error_Msg_NE ("subprogram& is not overriding", N, Rename_Spec);
2010 -- Normal subprogram renaming (not renaming as body)
2013 Generate_Definition (New_S);
2014 New_Overloaded_Entity (New_S);
2016 if Is_Entity_Name (Nam)
2017 and then Is_Intrinsic_Subprogram (Entity (Nam))
2021 Check_Delayed_Subprogram (New_S);
2025 -- There is no need for elaboration checks on the new entity, which may
2026 -- be called before the next freezing point where the body will appear.
2027 -- Elaboration checks refer to the real entity, not the one created by
2028 -- the renaming declaration.
2030 Set_Kill_Elaboration_Checks (New_S, True);
2032 if Etype (Nam) = Any_Type then
2033 Set_Has_Completion (New_S);
2036 elsif Nkind (Nam) = N_Selected_Component then
2038 -- A prefix of the form A.B can designate an entry of task A, a
2039 -- protected operation of protected object A, or finally a primitive
2040 -- operation of object A. In the later case, A is an object of some
2041 -- tagged type, or an access type that denotes one such. To further
2042 -- distinguish these cases, note that the scope of a task entry or
2043 -- protected operation is type of the prefix.
2045 -- The prefix could be an overloaded function call that returns both
2046 -- kinds of operations. This overloading pathology is left to the
2047 -- dedicated reader ???
2050 T : constant Entity_Id := Etype (Prefix (Nam));
2059 Is_Tagged_Type (Designated_Type (T))))
2060 and then Scope (Entity (Selector_Name (Nam))) /= T
2062 Analyze_Renamed_Primitive_Operation
2063 (N, New_S, Present (Rename_Spec));
2067 -- Renamed entity is an entry or protected operation. For those
2068 -- cases an explicit body is built (at the point of freezing of
2069 -- this entity) that contains a call to the renamed entity.
2071 -- This is not allowed for renaming as body if the renamed
2072 -- spec is already frozen (see RM 8.5.4(5) for details).
2074 if Present (Rename_Spec)
2075 and then Is_Frozen (Rename_Spec)
2078 ("renaming-as-body cannot rename entry as subprogram", N);
2080 ("\since & is already frozen (RM 8.5.4(5))",
2083 Analyze_Renamed_Entry (N, New_S, Present (Rename_Spec));
2090 elsif Nkind (Nam) = N_Explicit_Dereference then
2092 -- Renamed entity is designated by access_to_subprogram expression.
2093 -- Must build body to encapsulate call, as in the entry case.
2095 Analyze_Renamed_Dereference (N, New_S, Present (Rename_Spec));
2098 elsif Nkind (Nam) = N_Indexed_Component then
2099 Analyze_Renamed_Family_Member (N, New_S, Present (Rename_Spec));
2102 elsif Nkind (Nam) = N_Character_Literal then
2103 Analyze_Renamed_Character (N, New_S, Present (Rename_Spec));
2106 elsif not Is_Entity_Name (Nam)
2107 or else not Is_Overloadable (Entity (Nam))
2109 Error_Msg_N ("expect valid subprogram name in renaming", N);
2113 -- Find the renamed entity that matches the given specification. Disable
2114 -- Ada_83 because there is no requirement of full conformance between
2115 -- renamed entity and new entity, even though the same circuit is used.
2117 -- This is a bit of a kludge, which introduces a really irregular use of
2118 -- Ada_Version[_Explicit]. Would be nice to find cleaner way to do this
2121 Ada_Version := Ada_Version_Type'Max (Ada_Version, Ada_95);
2122 Ada_Version_Explicit := Ada_Version;
2125 Old_S := Find_Renamed_Entity (N, Name (N), New_S, Is_Actual);
2127 -- The visible operation may be an inherited abstract operation that
2128 -- was overridden in the private part, in which case a call will
2129 -- dispatch to the overriding operation. Use the overriding one in
2130 -- the renaming declaration, to prevent spurious errors below.
2132 if Is_Overloadable (Old_S)
2133 and then Is_Abstract_Subprogram (Old_S)
2134 and then No (DTC_Entity (Old_S))
2135 and then Present (Alias (Old_S))
2136 and then not Is_Abstract_Subprogram (Alias (Old_S))
2137 and then Present (Overridden_Operation (Alias (Old_S)))
2139 Old_S := Alias (Old_S);
2142 -- When the renamed subprogram is overloaded and used as an actual
2143 -- of a generic, its entity is set to the first available homonym.
2144 -- We must first disambiguate the name, then set the proper entity.
2147 and then Is_Overloaded (Nam)
2149 Set_Entity (Nam, Old_S);
2153 -- Most common case: subprogram renames subprogram. No body is generated
2154 -- in this case, so we must indicate the declaration is complete as is.
2155 -- and inherit various attributes of the renamed subprogram.
2157 if No (Rename_Spec) then
2158 Set_Has_Completion (New_S);
2159 Set_Is_Imported (New_S, Is_Imported (Entity (Nam)));
2160 Set_Is_Pure (New_S, Is_Pure (Entity (Nam)));
2161 Set_Is_Preelaborated (New_S, Is_Preelaborated (Entity (Nam)));
2163 -- Ada 2005 (AI-423): Check the consistency of null exclusions
2164 -- between a subprogram and its correct renaming.
2166 -- Note: the Any_Id check is a guard that prevents compiler crashes
2167 -- when performing a null exclusion check between a renaming and a
2168 -- renamed subprogram that has been found to be illegal.
2170 if Ada_Version >= Ada_2005
2171 and then Entity (Nam) /= Any_Id
2173 Check_Null_Exclusion
2175 Sub => Entity (Nam));
2178 -- Enforce the Ada 2005 rule that the renamed entity cannot require
2179 -- overriding. The flag Requires_Overriding is set very selectively
2180 -- and misses some other illegal cases. The additional conditions
2181 -- checked below are sufficient but not necessary ???
2183 -- The rule does not apply to the renaming generated for an actual
2184 -- subprogram in an instance.
2189 -- Guard against previous errors, and omit renamings of predefined
2192 elsif not Ekind_In (Old_S, E_Function, E_Procedure) then
2195 elsif Requires_Overriding (Old_S)
2197 (Is_Abstract_Subprogram (Old_S)
2198 and then Present (Find_Dispatching_Type (Old_S))
2200 not Is_Abstract_Type (Find_Dispatching_Type (Old_S)))
2203 ("renamed entity cannot be "
2204 & "subprogram that requires overriding (RM 8.5.4 (5.1))", N);
2208 if Old_S /= Any_Id then
2210 and then From_Default (N)
2212 -- This is an implicit reference to the default actual
2214 Generate_Reference (Old_S, Nam, Typ => 'i', Force => True);
2216 Generate_Reference (Old_S, Nam);
2219 -- For a renaming-as-body, require subtype conformance, but if the
2220 -- declaration being completed has not been frozen, then inherit the
2221 -- convention of the renamed subprogram prior to checking conformance
2222 -- (unless the renaming has an explicit convention established; the
2223 -- rule stated in the RM doesn't seem to address this ???).
2225 if Present (Rename_Spec) then
2226 Generate_Reference (Rename_Spec, Defining_Entity (Spec), 'b');
2227 Style.Check_Identifier (Defining_Entity (Spec), Rename_Spec);
2229 if not Is_Frozen (Rename_Spec) then
2230 if not Has_Convention_Pragma (Rename_Spec) then
2231 Set_Convention (New_S, Convention (Old_S));
2234 if Ekind (Old_S) /= E_Operator then
2235 Check_Mode_Conformant (New_S, Old_S, Spec);
2238 if Original_Subprogram (Old_S) = Rename_Spec then
2239 Error_Msg_N ("unfrozen subprogram cannot rename itself ", N);
2242 Check_Subtype_Conformant (New_S, Old_S, Spec);
2245 Check_Frozen_Renaming (N, Rename_Spec);
2247 -- Check explicitly that renamed entity is not intrinsic, because
2248 -- in a generic the renamed body is not built. In this case,
2249 -- the renaming_as_body is a completion.
2251 if Inside_A_Generic then
2252 if Is_Frozen (Rename_Spec)
2253 and then Is_Intrinsic_Subprogram (Old_S)
2256 ("subprogram in renaming_as_body cannot be intrinsic",
2260 Set_Has_Completion (Rename_Spec);
2263 elsif Ekind (Old_S) /= E_Operator then
2264 Check_Mode_Conformant (New_S, Old_S);
2267 and then Error_Posted (New_S)
2269 Error_Msg_NE ("invalid actual subprogram: & #!", N, Old_S);
2273 if No (Rename_Spec) then
2275 -- The parameter profile of the new entity is that of the renamed
2276 -- entity: the subtypes given in the specification are irrelevant.
2278 Inherit_Renamed_Profile (New_S, Old_S);
2280 -- A call to the subprogram is transformed into a call to the
2281 -- renamed entity. This is transitive if the renamed entity is
2282 -- itself a renaming.
2284 if Present (Alias (Old_S)) then
2285 Set_Alias (New_S, Alias (Old_S));
2287 Set_Alias (New_S, Old_S);
2290 -- Note that we do not set Is_Intrinsic_Subprogram if we have a
2291 -- renaming as body, since the entity in this case is not an
2292 -- intrinsic (it calls an intrinsic, but we have a real body for
2293 -- this call, and it is in this body that the required intrinsic
2294 -- processing will take place).
2296 -- Also, if this is a renaming of inequality, the renamed operator
2297 -- is intrinsic, but what matters is the corresponding equality
2298 -- operator, which may be user-defined.
2300 Set_Is_Intrinsic_Subprogram
2302 Is_Intrinsic_Subprogram (Old_S)
2304 (Chars (Old_S) /= Name_Op_Ne
2305 or else Ekind (Old_S) = E_Operator
2307 Is_Intrinsic_Subprogram
2308 (Corresponding_Equality (Old_S))));
2310 if Ekind (Alias (New_S)) = E_Operator then
2311 Set_Has_Delayed_Freeze (New_S, False);
2314 -- If the renaming corresponds to an association for an abstract
2315 -- formal subprogram, then various attributes must be set to
2316 -- indicate that the renaming is an abstract dispatching operation
2317 -- with a controlling type.
2319 if Is_Actual and then Is_Abstract_Subprogram (Formal_Spec) then
2321 -- Mark the renaming as abstract here, so Find_Dispatching_Type
2322 -- see it as corresponding to a generic association for a
2323 -- formal abstract subprogram
2325 Set_Is_Abstract_Subprogram (New_S);
2328 New_S_Ctrl_Type : constant Entity_Id :=
2329 Find_Dispatching_Type (New_S);
2330 Old_S_Ctrl_Type : constant Entity_Id :=
2331 Find_Dispatching_Type (Old_S);
2334 if Old_S_Ctrl_Type /= New_S_Ctrl_Type then
2336 ("actual must be dispatching subprogram for type&",
2337 Nam, New_S_Ctrl_Type);
2340 Set_Is_Dispatching_Operation (New_S);
2341 Check_Controlling_Formals (New_S_Ctrl_Type, New_S);
2343 -- If the actual in the formal subprogram is itself a
2344 -- formal abstract subprogram association, there's no
2345 -- dispatch table component or position to inherit.
2347 if Present (DTC_Entity (Old_S)) then
2348 Set_DTC_Entity (New_S, DTC_Entity (Old_S));
2349 Set_DT_Position (New_S, DT_Position (Old_S));
2357 and then (Old_S = New_S
2358 or else (Nkind (Nam) /= N_Expanded_Name
2359 and then Chars (Old_S) = Chars (New_S)))
2361 Error_Msg_N ("subprogram cannot rename itself", N);
2364 Set_Convention (New_S, Convention (Old_S));
2366 if Is_Abstract_Subprogram (Old_S) then
2367 if Present (Rename_Spec) then
2369 ("a renaming-as-body cannot rename an abstract subprogram",
2371 Set_Has_Completion (Rename_Spec);
2373 Set_Is_Abstract_Subprogram (New_S);
2377 Check_Library_Unit_Renaming (N, Old_S);
2379 -- Pathological case: procedure renames entry in the scope of its
2380 -- task. Entry is given by simple name, but body must be built for
2381 -- procedure. Of course if called it will deadlock.
2383 if Ekind (Old_S) = E_Entry then
2384 Set_Has_Completion (New_S, False);
2385 Set_Alias (New_S, Empty);
2389 Freeze_Before (N, Old_S);
2390 Set_Has_Delayed_Freeze (New_S, False);
2391 Freeze_Before (N, New_S);
2393 -- An abstract subprogram is only allowed as an actual in the case
2394 -- where the formal subprogram is also abstract.
2396 if (Ekind (Old_S) = E_Procedure or else Ekind (Old_S) = E_Function)
2397 and then Is_Abstract_Subprogram (Old_S)
2398 and then not Is_Abstract_Subprogram (Formal_Spec)
2401 ("abstract subprogram not allowed as generic actual", Nam);
2406 -- A common error is to assume that implicit operators for types are
2407 -- defined in Standard, or in the scope of a subtype. In those cases
2408 -- where the renamed entity is given with an expanded name, it is
2409 -- worth mentioning that operators for the type are not declared in
2410 -- the scope given by the prefix.
2412 if Nkind (Nam) = N_Expanded_Name
2413 and then Nkind (Selector_Name (Nam)) = N_Operator_Symbol
2414 and then Scope (Entity (Nam)) = Standard_Standard
2417 T : constant Entity_Id :=
2418 Base_Type (Etype (First_Formal (New_S)));
2420 Error_Msg_Node_2 := Prefix (Nam);
2422 ("operator for type& is not declared in&", Prefix (Nam), T);
2427 ("no visible subprogram matches the specification for&",
2431 if Present (Candidate_Renaming) then
2438 F1 := First_Formal (Candidate_Renaming);
2439 F2 := First_Formal (New_S);
2440 T1 := First_Subtype (Etype (F1));
2442 while Present (F1) and then Present (F2) loop
2447 if Present (F1) and then Present (Default_Value (F1)) then
2448 if Present (Next_Formal (F1)) then
2450 ("\missing specification for &" &
2451 " and other formals with defaults", Spec, F1);
2454 ("\missing specification for &", Spec, F1);
2458 if Nkind (Nam) = N_Operator_Symbol
2459 and then From_Default (N)
2461 Error_Msg_Node_2 := T1;
2463 ("default & on & is not directly visible",
2470 -- Ada 2005 AI 404: if the new subprogram is dispatching, verify that
2471 -- controlling access parameters are known non-null for the renamed
2472 -- subprogram. Test also applies to a subprogram instantiation that
2473 -- is dispatching. Test is skipped if some previous error was detected
2474 -- that set Old_S to Any_Id.
2476 if Ada_Version >= Ada_2005
2477 and then Old_S /= Any_Id
2478 and then not Is_Dispatching_Operation (Old_S)
2479 and then Is_Dispatching_Operation (New_S)
2486 Old_F := First_Formal (Old_S);
2487 New_F := First_Formal (New_S);
2488 while Present (Old_F) loop
2489 if Ekind (Etype (Old_F)) = E_Anonymous_Access_Type
2490 and then Is_Controlling_Formal (New_F)
2491 and then not Can_Never_Be_Null (Old_F)
2493 Error_Msg_N ("access parameter is controlling,", New_F);
2495 ("\corresponding parameter of& "
2496 & "must be explicitly null excluding", New_F, Old_S);
2499 Next_Formal (Old_F);
2500 Next_Formal (New_F);
2505 -- A useful warning, suggested by Ada Bug Finder (Ada-Europe 2005)
2506 -- is to warn if an operator is being renamed as a different operator.
2507 -- If the operator is predefined, examine the kind of the entity, not
2508 -- the abbreviated declaration in Standard.
2510 if Comes_From_Source (N)
2511 and then Present (Old_S)
2513 (Nkind (Old_S) = N_Defining_Operator_Symbol
2514 or else Ekind (Old_S) = E_Operator)
2515 and then Nkind (New_S) = N_Defining_Operator_Symbol
2516 and then Chars (Old_S) /= Chars (New_S)
2519 ("?& is being renamed as a different operator", N, Old_S);
2522 -- Check for renaming of obsolescent subprogram
2524 Check_Obsolescent_2005_Entity (Entity (Nam), Nam);
2526 -- Another warning or some utility: if the new subprogram as the same
2527 -- name as the old one, the old one is not hidden by an outer homograph,
2528 -- the new one is not a public symbol, and the old one is otherwise
2529 -- directly visible, the renaming is superfluous.
2531 if Chars (Old_S) = Chars (New_S)
2532 and then Comes_From_Source (N)
2533 and then Scope (Old_S) /= Standard_Standard
2534 and then Warn_On_Redundant_Constructs
2536 (Is_Immediately_Visible (Old_S)
2537 or else Is_Potentially_Use_Visible (Old_S))
2538 and then Is_Overloadable (Current_Scope)
2539 and then Chars (Current_Scope) /= Chars (Old_S)
2542 ("?redundant renaming, entity is directly visible", Name (N));
2545 Ada_Version := Save_AV;
2546 Ada_Version_Explicit := Save_AV_Exp;
2547 end Analyze_Subprogram_Renaming;
2549 -------------------------
2550 -- Analyze_Use_Package --
2551 -------------------------
2553 -- Resolve the package names in the use clause, and make all the visible
2554 -- entities defined in the package potentially use-visible. If the package
2555 -- is already in use from a previous use clause, its visible entities are
2556 -- already use-visible. In that case, mark the occurrence as a redundant
2557 -- use. If the package is an open scope, i.e. if the use clause occurs
2558 -- within the package itself, ignore it.
2560 procedure Analyze_Use_Package (N : Node_Id) is
2561 Pack_Name : Node_Id;
2564 -- Start of processing for Analyze_Use_Package
2567 -- Use package is not allowed in SPARK or ALFA
2569 if Formal_Verification_Mode then
2570 Error_Msg_F ("|~~use clause is not allowed", N);
2574 -- Proceed with analysis
2576 Set_Hidden_By_Use_Clause (N, No_Elist);
2578 -- Use clause is not allowed in a spec of a predefined package
2579 -- declaration except that packages whose file name starts a-n are OK
2580 -- (these are children of Ada.Numerics, and such packages are never
2581 -- loaded by Rtsfind).
2583 if Is_Predefined_File_Name (Unit_File_Name (Current_Sem_Unit))
2584 and then Name_Buffer (1 .. 3) /= "a-n"
2586 Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Declaration
2588 Error_Msg_N ("use clause not allowed in predefined spec", N);
2591 -- Chain clause to list of use clauses in current scope
2593 if Nkind (Parent (N)) /= N_Compilation_Unit then
2594 Chain_Use_Clause (N);
2597 -- Loop through package names to identify referenced packages
2599 Pack_Name := First (Names (N));
2600 while Present (Pack_Name) loop
2601 Analyze (Pack_Name);
2603 if Nkind (Parent (N)) = N_Compilation_Unit
2604 and then Nkind (Pack_Name) = N_Expanded_Name
2610 Pref := Prefix (Pack_Name);
2611 while Nkind (Pref) = N_Expanded_Name loop
2612 Pref := Prefix (Pref);
2615 if Entity (Pref) = Standard_Standard then
2617 ("predefined package Standard cannot appear"
2618 & " in a context clause", Pref);
2626 -- Loop through package names to mark all entities as potentially
2629 Pack_Name := First (Names (N));
2630 while Present (Pack_Name) loop
2631 if Is_Entity_Name (Pack_Name) then
2632 Pack := Entity (Pack_Name);
2634 if Ekind (Pack) /= E_Package
2635 and then Etype (Pack) /= Any_Type
2637 if Ekind (Pack) = E_Generic_Package then
2638 Error_Msg_N -- CODEFIX
2639 ("a generic package is not allowed in a use clause",
2642 Error_Msg_N ("& is not a usable package", Pack_Name);
2646 if Nkind (Parent (N)) = N_Compilation_Unit then
2647 Check_In_Previous_With_Clause (N, Pack_Name);
2650 if Applicable_Use (Pack_Name) then
2651 Use_One_Package (Pack, N);
2655 -- Report error because name denotes something other than a package
2658 Error_Msg_N ("& is not a package", Pack_Name);
2663 end Analyze_Use_Package;
2665 ----------------------
2666 -- Analyze_Use_Type --
2667 ----------------------
2669 procedure Analyze_Use_Type (N : Node_Id) is
2674 Set_Hidden_By_Use_Clause (N, No_Elist);
2676 -- Chain clause to list of use clauses in current scope
2678 if Nkind (Parent (N)) /= N_Compilation_Unit then
2679 Chain_Use_Clause (N);
2682 -- If the Used_Operations list is already initialized, the clause has
2683 -- been analyzed previously, and it is begin reinstalled, for example
2684 -- when the clause appears in a package spec and we are compiling the
2685 -- corresponding package body. In that case, make the entities on the
2686 -- existing list use_visible, and mark the corresponding types In_Use.
2688 if Present (Used_Operations (N)) then
2694 Mark := First (Subtype_Marks (N));
2695 while Present (Mark) loop
2696 if not In_Use (Entity (Mark))
2697 and then not Is_Potentially_Use_Visible (Entity (Mark))
2699 Set_In_Use (Base_Type (Entity (Mark)));
2704 Elmt := First_Elmt (Used_Operations (N));
2705 while Present (Elmt) loop
2706 Set_Is_Potentially_Use_Visible (Node (Elmt));
2714 -- Otherwise, create new list and attach to it the operations that
2715 -- are made use-visible by the clause.
2717 Set_Used_Operations (N, New_Elmt_List);
2718 Id := First (Subtype_Marks (N));
2719 while Present (Id) loop
2723 if E /= Any_Type then
2726 if Nkind (Parent (N)) = N_Compilation_Unit then
2727 if Nkind (Id) = N_Identifier then
2728 Error_Msg_N ("type is not directly visible", Id);
2730 elsif Is_Child_Unit (Scope (E))
2731 and then Scope (E) /= System_Aux_Id
2733 Check_In_Previous_With_Clause (N, Prefix (Id));
2738 -- If the use_type_clause appears in a compilation unit context,
2739 -- check whether it comes from a unit that may appear in a
2740 -- limited_with_clause, for a better error message.
2742 if Nkind (Parent (N)) = N_Compilation_Unit
2743 and then Nkind (Id) /= N_Identifier
2749 function Mentioned (Nam : Node_Id) return Boolean;
2750 -- Check whether the prefix of expanded name for the type
2751 -- appears in the prefix of some limited_with_clause.
2757 function Mentioned (Nam : Node_Id) return Boolean is
2759 return Nkind (Name (Item)) = N_Selected_Component
2761 Chars (Prefix (Name (Item))) = Chars (Nam);
2765 Pref := Prefix (Id);
2766 Item := First (Context_Items (Parent (N)));
2768 while Present (Item) and then Item /= N loop
2769 if Nkind (Item) = N_With_Clause
2770 and then Limited_Present (Item)
2771 and then Mentioned (Pref)
2774 (Get_Msg_Id, "premature usage of incomplete type");
2785 end Analyze_Use_Type;
2787 --------------------
2788 -- Applicable_Use --
2789 --------------------
2791 function Applicable_Use (Pack_Name : Node_Id) return Boolean is
2792 Pack : constant Entity_Id := Entity (Pack_Name);
2795 if In_Open_Scopes (Pack) then
2796 if Warn_On_Redundant_Constructs
2797 and then Pack = Current_Scope
2799 Error_Msg_NE -- CODEFIX
2800 ("& is already use-visible within itself?", Pack_Name, Pack);
2805 elsif In_Use (Pack) then
2806 Note_Redundant_Use (Pack_Name);
2809 elsif Present (Renamed_Object (Pack))
2810 and then In_Use (Renamed_Object (Pack))
2812 Note_Redundant_Use (Pack_Name);
2820 ------------------------
2821 -- Attribute_Renaming --
2822 ------------------------
2824 procedure Attribute_Renaming (N : Node_Id) is
2825 Loc : constant Source_Ptr := Sloc (N);
2826 Nam : constant Node_Id := Name (N);
2827 Spec : constant Node_Id := Specification (N);
2828 New_S : constant Entity_Id := Defining_Unit_Name (Spec);
2829 Aname : constant Name_Id := Attribute_Name (Nam);
2831 Form_Num : Nat := 0;
2832 Expr_List : List_Id := No_List;
2834 Attr_Node : Node_Id;
2835 Body_Node : Node_Id;
2836 Param_Spec : Node_Id;
2839 Generate_Definition (New_S);
2841 -- This procedure is called in the context of subprogram renaming, and
2842 -- thus the attribute must be one that is a subprogram. All of those
2843 -- have at least one formal parameter, with the singular exception of
2844 -- AST_Entry (which is a real oddity, it is odd that this can be renamed
2847 if not Is_Non_Empty_List (Parameter_Specifications (Spec)) then
2848 if Aname /= Name_AST_Entry then
2850 ("subprogram renaming an attribute must have formals", N);
2855 Param_Spec := First (Parameter_Specifications (Spec));
2856 while Present (Param_Spec) loop
2857 Form_Num := Form_Num + 1;
2859 if Nkind (Parameter_Type (Param_Spec)) /= N_Access_Definition then
2860 Find_Type (Parameter_Type (Param_Spec));
2862 -- The profile of the new entity denotes the base type (s) of
2863 -- the types given in the specification. For access parameters
2864 -- there are no subtypes involved.
2866 Rewrite (Parameter_Type (Param_Spec),
2868 (Base_Type (Entity (Parameter_Type (Param_Spec))), Loc));
2871 if No (Expr_List) then
2872 Expr_List := New_List;
2875 Append_To (Expr_List,
2876 Make_Identifier (Loc,
2877 Chars => Chars (Defining_Identifier (Param_Spec))));
2879 -- The expressions in the attribute reference are not freeze
2880 -- points. Neither is the attribute as a whole, see below.
2882 Set_Must_Not_Freeze (Last (Expr_List));
2887 -- Immediate error if too many formals. Other mismatches in number or
2888 -- types of parameters are detected when we analyze the body of the
2889 -- subprogram that we construct.
2891 if Form_Num > 2 then
2892 Error_Msg_N ("too many formals for attribute", N);
2894 -- Error if the attribute reference has expressions that look like
2895 -- formal parameters.
2897 elsif Present (Expressions (Nam)) then
2898 Error_Msg_N ("illegal expressions in attribute reference", Nam);
2901 Aname = Name_Compose or else
2902 Aname = Name_Exponent or else
2903 Aname = Name_Leading_Part or else
2904 Aname = Name_Pos or else
2905 Aname = Name_Round or else
2906 Aname = Name_Scaling or else
2909 if Nkind (N) = N_Subprogram_Renaming_Declaration
2910 and then Present (Corresponding_Formal_Spec (N))
2913 ("generic actual cannot be attribute involving universal type",
2917 ("attribute involving a universal type cannot be renamed",
2922 -- AST_Entry is an odd case. It doesn't really make much sense to allow
2923 -- it to be renamed, but that's the DEC rule, so we have to do it right.
2924 -- The point is that the AST_Entry call should be made now, and what the
2925 -- function will return is the returned value.
2927 -- Note that there is no Expr_List in this case anyway
2929 if Aname = Name_AST_Entry then
2931 Ent : constant Entity_Id := Make_Temporary (Loc, 'R', Nam);
2936 Make_Object_Declaration (Loc,
2937 Defining_Identifier => Ent,
2938 Object_Definition =>
2939 New_Occurrence_Of (RTE (RE_AST_Handler), Loc),
2941 Constant_Present => True);
2943 Set_Assignment_OK (Decl, True);
2944 Insert_Action (N, Decl);
2945 Attr_Node := Make_Identifier (Loc, Chars (Ent));
2948 -- For all other attributes, we rewrite the attribute node to have
2949 -- a list of expressions corresponding to the subprogram formals.
2950 -- A renaming declaration is not a freeze point, and the analysis of
2951 -- the attribute reference should not freeze the type of the prefix.
2955 Make_Attribute_Reference (Loc,
2956 Prefix => Prefix (Nam),
2957 Attribute_Name => Aname,
2958 Expressions => Expr_List);
2960 Set_Must_Not_Freeze (Attr_Node);
2961 Set_Must_Not_Freeze (Prefix (Nam));
2964 -- Case of renaming a function
2966 if Nkind (Spec) = N_Function_Specification then
2967 if Is_Procedure_Attribute_Name (Aname) then
2968 Error_Msg_N ("attribute can only be renamed as procedure", Nam);
2972 Find_Type (Result_Definition (Spec));
2973 Rewrite (Result_Definition (Spec),
2975 Base_Type (Entity (Result_Definition (Spec))), Loc));
2978 Make_Subprogram_Body (Loc,
2979 Specification => Spec,
2980 Declarations => New_List,
2981 Handled_Statement_Sequence =>
2982 Make_Handled_Sequence_Of_Statements (Loc,
2983 Statements => New_List (
2984 Make_Simple_Return_Statement (Loc,
2985 Expression => Attr_Node))));
2987 -- Case of renaming a procedure
2990 if not Is_Procedure_Attribute_Name (Aname) then
2991 Error_Msg_N ("attribute can only be renamed as function", Nam);
2996 Make_Subprogram_Body (Loc,
2997 Specification => Spec,
2998 Declarations => New_List,
2999 Handled_Statement_Sequence =>
3000 Make_Handled_Sequence_Of_Statements (Loc,
3001 Statements => New_List (Attr_Node)));
3004 -- In case of tagged types we add the body of the generated function to
3005 -- the freezing actions of the type (because in the general case such
3006 -- type is still not frozen). We exclude from this processing generic
3007 -- formal subprograms found in instantiations and AST_Entry renamings.
3009 -- We must exclude VM targets because entity AST_Handler is defined in
3010 -- package System.Aux_Dec which is not available in those platforms.
3012 if VM_Target = No_VM
3013 and then not Present (Corresponding_Formal_Spec (N))
3014 and then Etype (Nam) /= RTE (RE_AST_Handler)
3017 P : constant Entity_Id := Prefix (Nam);
3022 if Is_Tagged_Type (Etype (P)) then
3023 Ensure_Freeze_Node (Etype (P));
3024 Append_Freeze_Action (Etype (P), Body_Node);
3026 Rewrite (N, Body_Node);
3028 Set_Etype (New_S, Base_Type (Etype (New_S)));
3032 -- Generic formal subprograms or AST_Handler renaming
3035 Rewrite (N, Body_Node);
3037 Set_Etype (New_S, Base_Type (Etype (New_S)));
3040 if Is_Compilation_Unit (New_S) then
3042 ("a library unit can only rename another library unit", N);
3045 -- We suppress elaboration warnings for the resulting entity, since
3046 -- clearly they are not needed, and more particularly, in the case
3047 -- of a generic formal subprogram, the resulting entity can appear
3048 -- after the instantiation itself, and thus look like a bogus case
3049 -- of access before elaboration.
3051 Set_Suppress_Elaboration_Warnings (New_S);
3053 end Attribute_Renaming;
3055 ----------------------
3056 -- Chain_Use_Clause --
3057 ----------------------
3059 procedure Chain_Use_Clause (N : Node_Id) is
3061 Level : Int := Scope_Stack.Last;
3064 if not Is_Compilation_Unit (Current_Scope)
3065 or else not Is_Child_Unit (Current_Scope)
3067 null; -- Common case
3069 elsif Defining_Entity (Parent (N)) = Current_Scope then
3070 null; -- Common case for compilation unit
3073 -- If declaration appears in some other scope, it must be in some
3074 -- parent unit when compiling a child.
3076 Pack := Defining_Entity (Parent (N));
3077 if not In_Open_Scopes (Pack) then
3078 null; -- default as well
3081 -- Find entry for parent unit in scope stack
3083 while Scope_Stack.Table (Level).Entity /= Pack loop
3089 Set_Next_Use_Clause (N,
3090 Scope_Stack.Table (Level).First_Use_Clause);
3091 Scope_Stack.Table (Level).First_Use_Clause := N;
3092 end Chain_Use_Clause;
3094 ---------------------------
3095 -- Check_Frozen_Renaming --
3096 ---------------------------
3098 procedure Check_Frozen_Renaming (N : Node_Id; Subp : Entity_Id) is
3104 and then not Has_Completion (Subp)
3108 (Parent (Declaration_Node (Subp)), Defining_Entity (N));
3110 if Is_Entity_Name (Name (N)) then
3111 Old_S := Entity (Name (N));
3113 if not Is_Frozen (Old_S)
3114 and then Operating_Mode /= Check_Semantics
3116 Append_Freeze_Action (Old_S, B_Node);
3118 Insert_After (N, B_Node);
3122 if Is_Intrinsic_Subprogram (Old_S)
3123 and then not In_Instance
3126 ("subprogram used in renaming_as_body cannot be intrinsic",
3131 Insert_After (N, B_Node);
3135 end Check_Frozen_Renaming;
3137 -------------------------------
3138 -- Set_Entity_Or_Discriminal --
3139 -------------------------------
3141 procedure Set_Entity_Or_Discriminal (N : Node_Id; E : Entity_Id) is
3145 -- If the entity is not a discriminant, or else expansion is disabled,
3146 -- simply set the entity.
3148 if not In_Spec_Expression
3149 or else Ekind (E) /= E_Discriminant
3150 or else Inside_A_Generic
3152 Set_Entity_With_Style_Check (N, E);
3154 -- The replacement of a discriminant by the corresponding discriminal
3155 -- is not done for a task discriminant that appears in a default
3156 -- expression of an entry parameter. See Exp_Ch2.Expand_Discriminant
3157 -- for details on their handling.
3159 elsif Is_Concurrent_Type (Scope (E)) then
3163 and then not Nkind_In (P, N_Parameter_Specification,
3164 N_Component_Declaration)
3170 and then Nkind (P) = N_Parameter_Specification
3175 Set_Entity (N, Discriminal (E));
3178 -- Otherwise, this is a discriminant in a context in which
3179 -- it is a reference to the corresponding parameter of the
3180 -- init proc for the enclosing type.
3183 Set_Entity (N, Discriminal (E));
3185 end Set_Entity_Or_Discriminal;
3187 -----------------------------------
3188 -- Check_In_Previous_With_Clause --
3189 -----------------------------------
3191 procedure Check_In_Previous_With_Clause
3195 Pack : constant Entity_Id := Entity (Original_Node (Nam));
3200 Item := First (Context_Items (Parent (N)));
3202 while Present (Item)
3205 if Nkind (Item) = N_With_Clause
3207 -- Protect the frontend against previous critical errors
3209 and then Nkind (Name (Item)) /= N_Selected_Component
3210 and then Entity (Name (Item)) = Pack
3214 -- Find root library unit in with_clause
3216 while Nkind (Par) = N_Expanded_Name loop
3217 Par := Prefix (Par);
3220 if Is_Child_Unit (Entity (Original_Node (Par))) then
3221 Error_Msg_NE ("& is not directly visible", Par, Entity (Par));
3230 -- On exit, package is not mentioned in a previous with_clause.
3231 -- Check if its prefix is.
3233 if Nkind (Nam) = N_Expanded_Name then
3234 Check_In_Previous_With_Clause (N, Prefix (Nam));
3236 elsif Pack /= Any_Id then
3237 Error_Msg_NE ("& is not visible", Nam, Pack);
3239 end Check_In_Previous_With_Clause;
3241 ---------------------------------
3242 -- Check_Library_Unit_Renaming --
3243 ---------------------------------
3245 procedure Check_Library_Unit_Renaming (N : Node_Id; Old_E : Entity_Id) is
3249 if Nkind (Parent (N)) /= N_Compilation_Unit then
3252 -- Check for library unit. Note that we used to check for the scope
3253 -- being Standard here, but that was wrong for Standard itself.
3255 elsif not Is_Compilation_Unit (Old_E)
3256 and then not Is_Child_Unit (Old_E)
3258 Error_Msg_N ("renamed unit must be a library unit", Name (N));
3260 -- Entities defined in Standard (operators and boolean literals) cannot
3261 -- be renamed as library units.
3263 elsif Scope (Old_E) = Standard_Standard
3264 and then Sloc (Old_E) = Standard_Location
3266 Error_Msg_N ("renamed unit must be a library unit", Name (N));
3268 elsif Present (Parent_Spec (N))
3269 and then Nkind (Unit (Parent_Spec (N))) = N_Generic_Package_Declaration
3270 and then not Is_Child_Unit (Old_E)
3273 ("renamed unit must be a child unit of generic parent", Name (N));
3275 elsif Nkind (N) in N_Generic_Renaming_Declaration
3276 and then Nkind (Name (N)) = N_Expanded_Name
3277 and then Is_Generic_Instance (Entity (Prefix (Name (N))))
3278 and then Is_Generic_Unit (Old_E)
3281 ("renamed generic unit must be a library unit", Name (N));
3283 elsif Is_Package_Or_Generic_Package (Old_E) then
3285 -- Inherit categorization flags
3287 New_E := Defining_Entity (N);
3288 Set_Is_Pure (New_E, Is_Pure (Old_E));
3289 Set_Is_Preelaborated (New_E, Is_Preelaborated (Old_E));
3290 Set_Is_Remote_Call_Interface (New_E,
3291 Is_Remote_Call_Interface (Old_E));
3292 Set_Is_Remote_Types (New_E, Is_Remote_Types (Old_E));
3293 Set_Is_Shared_Passive (New_E, Is_Shared_Passive (Old_E));
3295 end Check_Library_Unit_Renaming;
3301 procedure End_Scope is
3307 Id := First_Entity (Current_Scope);
3308 while Present (Id) loop
3309 -- An entity in the current scope is not necessarily the first one
3310 -- on its homonym chain. Find its predecessor if any,
3311 -- If it is an internal entity, it will not be in the visibility
3312 -- chain altogether, and there is nothing to unchain.
3314 if Id /= Current_Entity (Id) then
3315 Prev := Current_Entity (Id);
3316 while Present (Prev)
3317 and then Present (Homonym (Prev))
3318 and then Homonym (Prev) /= Id
3320 Prev := Homonym (Prev);
3323 -- Skip to end of loop if Id is not in the visibility chain
3325 if No (Prev) or else Homonym (Prev) /= Id then
3333 Set_Is_Immediately_Visible (Id, False);
3335 Outer := Homonym (Id);
3336 while Present (Outer) and then Scope (Outer) = Current_Scope loop
3337 Outer := Homonym (Outer);
3340 -- Reset homonym link of other entities, but do not modify link
3341 -- between entities in current scope, so that the back-end can have
3342 -- a proper count of local overloadings.
3345 Set_Name_Entity_Id (Chars (Id), Outer);
3347 elsif Scope (Prev) /= Scope (Id) then
3348 Set_Homonym (Prev, Outer);
3355 -- If the scope generated freeze actions, place them before the
3356 -- current declaration and analyze them. Type declarations and
3357 -- the bodies of initialization procedures can generate such nodes.
3358 -- We follow the parent chain until we reach a list node, which is
3359 -- the enclosing list of declarations. If the list appears within
3360 -- a protected definition, move freeze nodes outside the protected
3364 (Scope_Stack.Table (Scope_Stack.Last).Pending_Freeze_Actions)
3368 L : constant List_Id := Scope_Stack.Table
3369 (Scope_Stack.Last).Pending_Freeze_Actions;
3372 if Is_Itype (Current_Scope) then
3373 Decl := Associated_Node_For_Itype (Current_Scope);
3375 Decl := Parent (Current_Scope);
3380 while not (Is_List_Member (Decl))
3381 or else Nkind_In (Parent (Decl), N_Protected_Definition,
3384 Decl := Parent (Decl);
3387 Insert_List_Before_And_Analyze (Decl, L);
3396 ---------------------
3397 -- End_Use_Clauses --
3398 ---------------------
3400 procedure End_Use_Clauses (Clause : Node_Id) is
3404 -- Remove Use_Type clauses first, because they affect the
3405 -- visibility of operators in subsequent used packages.
3408 while Present (U) loop
3409 if Nkind (U) = N_Use_Type_Clause then
3413 Next_Use_Clause (U);
3417 while Present (U) loop
3418 if Nkind (U) = N_Use_Package_Clause then
3419 End_Use_Package (U);
3422 Next_Use_Clause (U);
3424 end End_Use_Clauses;
3426 ---------------------
3427 -- End_Use_Package --
3428 ---------------------
3430 procedure End_Use_Package (N : Node_Id) is
3431 Pack_Name : Node_Id;
3436 function Is_Primitive_Operator_In_Use
3438 F : Entity_Id) return Boolean;
3439 -- Check whether Op is a primitive operator of a use-visible type
3441 ----------------------------------
3442 -- Is_Primitive_Operator_In_Use --
3443 ----------------------------------
3445 function Is_Primitive_Operator_In_Use
3447 F : Entity_Id) return Boolean
3449 T : constant Entity_Id := Etype (F);
3452 or else Present (Current_Use_Clause (Base_Type (T))))
3453 and then Scope (T) = Scope (Op);
3454 end Is_Primitive_Operator_In_Use;
3456 -- Start of processing for End_Use_Package
3459 Pack_Name := First (Names (N));
3460 while Present (Pack_Name) loop
3462 -- Test that Pack_Name actually denotes a package before processing
3464 if Is_Entity_Name (Pack_Name)
3465 and then Ekind (Entity (Pack_Name)) = E_Package
3467 Pack := Entity (Pack_Name);
3469 if In_Open_Scopes (Pack) then
3472 elsif not Redundant_Use (Pack_Name) then
3473 Set_In_Use (Pack, False);
3474 Set_Current_Use_Clause (Pack, Empty);
3476 Id := First_Entity (Pack);
3477 while Present (Id) loop
3479 -- Preserve use-visibility of operators that are primitive
3480 -- operators of a type that is use-visible through an active
3483 if Nkind (Id) = N_Defining_Operator_Symbol
3485 (Is_Primitive_Operator_In_Use
3486 (Id, First_Formal (Id))
3488 (Present (Next_Formal (First_Formal (Id)))
3490 Is_Primitive_Operator_In_Use
3491 (Id, Next_Formal (First_Formal (Id)))))
3496 Set_Is_Potentially_Use_Visible (Id, False);
3499 if Is_Private_Type (Id)
3500 and then Present (Full_View (Id))
3502 Set_Is_Potentially_Use_Visible (Full_View (Id), False);
3508 if Present (Renamed_Object (Pack)) then
3509 Set_In_Use (Renamed_Object (Pack), False);
3510 Set_Current_Use_Clause (Renamed_Object (Pack), Empty);
3513 if Chars (Pack) = Name_System
3514 and then Scope (Pack) = Standard_Standard
3515 and then Present_System_Aux
3517 Id := First_Entity (System_Aux_Id);
3518 while Present (Id) loop
3519 Set_Is_Potentially_Use_Visible (Id, False);
3521 if Is_Private_Type (Id)
3522 and then Present (Full_View (Id))
3524 Set_Is_Potentially_Use_Visible (Full_View (Id), False);
3530 Set_In_Use (System_Aux_Id, False);
3534 Set_Redundant_Use (Pack_Name, False);
3541 if Present (Hidden_By_Use_Clause (N)) then
3542 Elmt := First_Elmt (Hidden_By_Use_Clause (N));
3543 while Present (Elmt) loop
3545 E : constant Entity_Id := Node (Elmt);
3548 -- Reset either Use_Visibility or Direct_Visibility, depending
3549 -- on how the entity was hidden by the use clause.
3551 if In_Use (Scope (E))
3552 and then Used_As_Generic_Actual (Scope (E))
3554 Set_Is_Potentially_Use_Visible (Node (Elmt));
3556 Set_Is_Immediately_Visible (Node (Elmt));
3563 Set_Hidden_By_Use_Clause (N, No_Elist);
3565 end End_Use_Package;
3571 procedure End_Use_Type (N : Node_Id) is
3576 -- Start of processing for End_Use_Type
3579 Id := First (Subtype_Marks (N));
3580 while Present (Id) loop
3582 -- A call to Rtsfind may occur while analyzing a use_type clause,
3583 -- in which case the type marks are not resolved yet, and there is
3584 -- nothing to remove.
3586 if not Is_Entity_Name (Id) or else No (Entity (Id)) then
3592 if T = Any_Type or else From_With_Type (T) then
3595 -- Note that the use_type clause may mention a subtype of the type
3596 -- whose primitive operations have been made visible. Here as
3597 -- elsewhere, it is the base type that matters for visibility.
3599 elsif In_Open_Scopes (Scope (Base_Type (T))) then
3602 elsif not Redundant_Use (Id) then
3603 Set_In_Use (T, False);
3604 Set_In_Use (Base_Type (T), False);
3605 Set_Current_Use_Clause (T, Empty);
3606 Set_Current_Use_Clause (Base_Type (T), Empty);
3613 if Is_Empty_Elmt_List (Used_Operations (N)) then
3617 Elmt := First_Elmt (Used_Operations (N));
3618 while Present (Elmt) loop
3619 Set_Is_Potentially_Use_Visible (Node (Elmt), False);
3625 ----------------------
3626 -- Find_Direct_Name --
3627 ----------------------
3629 procedure Find_Direct_Name (N : Node_Id) is
3634 Inst : Entity_Id := Empty;
3635 -- Enclosing instance, if any
3637 Homonyms : Entity_Id;
3638 -- Saves start of homonym chain
3640 Nvis_Entity : Boolean;
3641 -- Set True to indicate that there is at least one entity on the homonym
3642 -- chain which, while not visible, is visible enough from the user point
3643 -- of view to warrant an error message of "not visible" rather than
3646 Nvis_Is_Private_Subprg : Boolean := False;
3647 -- Ada 2005 (AI-262): Set True to indicate that a form of Beaujolais
3648 -- effect concerning library subprograms has been detected. Used to
3649 -- generate the precise error message.
3651 function From_Actual_Package (E : Entity_Id) return Boolean;
3652 -- Returns true if the entity is declared in a package that is
3653 -- an actual for a formal package of the current instance. Such an
3654 -- entity requires special handling because it may be use-visible
3655 -- but hides directly visible entities defined outside the instance.
3657 function Is_Actual_Parameter return Boolean;
3658 -- This function checks if the node N is an identifier that is an actual
3659 -- parameter of a procedure call. If so it returns True, otherwise it
3660 -- return False. The reason for this check is that at this stage we do
3661 -- not know what procedure is being called if the procedure might be
3662 -- overloaded, so it is premature to go setting referenced flags or
3663 -- making calls to Generate_Reference. We will wait till Resolve_Actuals
3664 -- for that processing
3666 function Known_But_Invisible (E : Entity_Id) return Boolean;
3667 -- This function determines whether the entity E (which is not
3668 -- visible) can reasonably be considered to be known to the writer
3669 -- of the reference. This is a heuristic test, used only for the
3670 -- purposes of figuring out whether we prefer to complain that an
3671 -- entity is undefined or invisible (and identify the declaration
3672 -- of the invisible entity in the latter case). The point here is
3673 -- that we don't want to complain that something is invisible and
3674 -- then point to something entirely mysterious to the writer.
3676 procedure Nvis_Messages;
3677 -- Called if there are no visible entries for N, but there is at least
3678 -- one non-directly visible, or hidden declaration. This procedure
3679 -- outputs an appropriate set of error messages.
3681 procedure Undefined (Nvis : Boolean);
3682 -- This function is called if the current node has no corresponding
3683 -- visible entity or entities. The value set in Msg indicates whether
3684 -- an error message was generated (multiple error messages for the
3685 -- same variable are generally suppressed, see body for details).
3686 -- Msg is True if an error message was generated, False if not. This
3687 -- value is used by the caller to determine whether or not to output
3688 -- additional messages where appropriate. The parameter is set False
3689 -- to get the message "X is undefined", and True to get the message
3690 -- "X is not visible".
3692 -------------------------
3693 -- From_Actual_Package --
3694 -------------------------
3696 function From_Actual_Package (E : Entity_Id) return Boolean is
3697 Scop : constant Entity_Id := Scope (E);
3701 if not In_Instance then
3704 Inst := Current_Scope;
3705 while Present (Inst)
3706 and then Ekind (Inst) /= E_Package
3707 and then not Is_Generic_Instance (Inst)
3709 Inst := Scope (Inst);
3716 Act := First_Entity (Inst);
3717 while Present (Act) loop
3718 if Ekind (Act) = E_Package then
3720 -- Check for end of actuals list
3722 if Renamed_Object (Act) = Inst then
3725 elsif Present (Associated_Formal_Package (Act))
3726 and then Renamed_Object (Act) = Scop
3728 -- Entity comes from (instance of) formal package
3743 end From_Actual_Package;
3745 -------------------------
3746 -- Is_Actual_Parameter --
3747 -------------------------
3749 function Is_Actual_Parameter return Boolean is
3752 Nkind (N) = N_Identifier
3754 (Nkind (Parent (N)) = N_Procedure_Call_Statement
3756 (Nkind (Parent (N)) = N_Parameter_Association
3757 and then N = Explicit_Actual_Parameter (Parent (N))
3758 and then Nkind (Parent (Parent (N))) =
3759 N_Procedure_Call_Statement));
3760 end Is_Actual_Parameter;
3762 -------------------------
3763 -- Known_But_Invisible --
3764 -------------------------
3766 function Known_But_Invisible (E : Entity_Id) return Boolean is
3767 Fname : File_Name_Type;
3770 -- Entities in Standard are always considered to be known
3772 if Sloc (E) <= Standard_Location then
3775 -- An entity that does not come from source is always considered
3776 -- to be unknown, since it is an artifact of code expansion.
3778 elsif not Comes_From_Source (E) then
3781 -- In gnat internal mode, we consider all entities known
3783 elsif GNAT_Mode then
3787 -- Here we have an entity that is not from package Standard, and
3788 -- which comes from Source. See if it comes from an internal file.
3790 Fname := Unit_File_Name (Get_Source_Unit (E));
3792 -- Case of from internal file
3794 if Is_Internal_File_Name (Fname) then
3796 -- Private part entities in internal files are never considered
3797 -- to be known to the writer of normal application code.
3799 if Is_Hidden (E) then
3803 -- Entities from System packages other than System and
3804 -- System.Storage_Elements are not considered to be known.
3805 -- System.Auxxxx files are also considered known to the user.
3807 -- Should refine this at some point to generally distinguish
3808 -- between known and unknown internal files ???
3810 Get_Name_String (Fname);
3815 Name_Buffer (1 .. 2) /= "s-"
3817 Name_Buffer (3 .. 8) = "stoele"
3819 Name_Buffer (3 .. 5) = "aux";
3821 -- If not an internal file, then entity is definitely known,
3822 -- even if it is in a private part (the message generated will
3823 -- note that it is in a private part)
3828 end Known_But_Invisible;
3834 procedure Nvis_Messages is
3835 Comp_Unit : Node_Id;
3837 Found : Boolean := False;
3838 Hidden : Boolean := False;
3842 -- Ada 2005 (AI-262): Generate a precise error concerning the
3843 -- Beaujolais effect that was previously detected
3845 if Nvis_Is_Private_Subprg then
3847 pragma Assert (Nkind (E2) = N_Defining_Identifier
3848 and then Ekind (E2) = E_Function
3849 and then Scope (E2) = Standard_Standard
3850 and then Has_Private_With (E2));
3852 -- Find the sloc corresponding to the private with'ed unit
3854 Comp_Unit := Cunit (Current_Sem_Unit);
3855 Error_Msg_Sloc := No_Location;
3857 Item := First (Context_Items (Comp_Unit));
3858 while Present (Item) loop
3859 if Nkind (Item) = N_With_Clause
3860 and then Private_Present (Item)
3861 and then Entity (Name (Item)) = E2
3863 Error_Msg_Sloc := Sloc (Item);
3870 pragma Assert (Error_Msg_Sloc /= No_Location);
3872 Error_Msg_N ("(Ada 2005): hidden by private with clause #", N);
3876 Undefined (Nvis => True);
3880 -- First loop does hidden declarations
3883 while Present (Ent) loop
3884 if Is_Potentially_Use_Visible (Ent) then
3886 Error_Msg_N -- CODEFIX
3887 ("multiple use clauses cause hiding!", N);
3891 Error_Msg_Sloc := Sloc (Ent);
3892 Error_Msg_N -- CODEFIX
3893 ("hidden declaration#!", N);
3896 Ent := Homonym (Ent);
3899 -- If we found hidden declarations, then that's enough, don't
3900 -- bother looking for non-visible declarations as well.
3906 -- Second loop does non-directly visible declarations
3909 while Present (Ent) loop
3910 if not Is_Potentially_Use_Visible (Ent) then
3912 -- Do not bother the user with unknown entities
3914 if not Known_But_Invisible (Ent) then
3918 Error_Msg_Sloc := Sloc (Ent);
3920 -- Output message noting that there is a non-visible
3921 -- declaration, distinguishing the private part case.
3923 if Is_Hidden (Ent) then
3924 Error_Msg_N ("non-visible (private) declaration#!", N);
3926 -- If the entity is declared in a generic package, it
3927 -- cannot be visible, so there is no point in adding it
3928 -- to the list of candidates if another homograph from a
3929 -- non-generic package has been seen.
3931 elsif Ekind (Scope (Ent)) = E_Generic_Package
3937 Error_Msg_N -- CODEFIX
3938 ("non-visible declaration#!", N);
3940 if Ekind (Scope (Ent)) /= E_Generic_Package then
3944 if Is_Compilation_Unit (Ent)
3946 Nkind (Parent (Parent (N))) = N_Use_Package_Clause
3948 Error_Msg_Qual_Level := 99;
3949 Error_Msg_NE -- CODEFIX
3950 ("\\missing `WITH &;`", N, Ent);
3951 Error_Msg_Qual_Level := 0;
3954 if Ekind (Ent) = E_Discriminant
3955 and then Present (Corresponding_Discriminant (Ent))
3956 and then Scope (Corresponding_Discriminant (Ent)) =
3960 ("inherited discriminant not allowed here" &
3961 " (RM 3.8 (12), 3.8.1 (6))!", N);
3965 -- Set entity and its containing package as referenced. We
3966 -- can't be sure of this, but this seems a better choice
3967 -- to avoid unused entity messages.
3969 if Comes_From_Source (Ent) then
3970 Set_Referenced (Ent);
3971 Set_Referenced (Cunit_Entity (Get_Source_Unit (Ent)));
3976 Ent := Homonym (Ent);
3985 procedure Undefined (Nvis : Boolean) is
3986 Emsg : Error_Msg_Id;
3989 -- We should never find an undefined internal name. If we do, then
3990 -- see if we have previous errors. If so, ignore on the grounds that
3991 -- it is probably a cascaded message (e.g. a block label from a badly
3992 -- formed block). If no previous errors, then we have a real internal
3993 -- error of some kind so raise an exception.
3995 if Is_Internal_Name (Chars (N)) then
3996 if Total_Errors_Detected /= 0 then
3999 raise Program_Error;
4003 -- A very specialized error check, if the undefined variable is
4004 -- a case tag, and the case type is an enumeration type, check
4005 -- for a possible misspelling, and if so, modify the identifier
4007 -- Named aggregate should also be handled similarly ???
4009 if Nkind (N) = N_Identifier
4010 and then Nkind (Parent (N)) = N_Case_Statement_Alternative
4013 Case_Stm : constant Node_Id := Parent (Parent (N));
4014 Case_Typ : constant Entity_Id := Etype (Expression (Case_Stm));
4019 if Is_Enumeration_Type (Case_Typ)
4020 and then not Is_Standard_Character_Type (Case_Typ)
4022 Lit := First_Literal (Case_Typ);
4023 Get_Name_String (Chars (Lit));
4025 if Chars (Lit) /= Chars (N)
4026 and then Is_Bad_Spelling_Of (Chars (N), Chars (Lit)) then
4027 Error_Msg_Node_2 := Lit;
4028 Error_Msg_N -- CODEFIX
4029 ("& is undefined, assume misspelling of &", N);
4030 Rewrite (N, New_Occurrence_Of (Lit, Sloc (N)));
4034 Lit := Next_Literal (Lit);
4039 -- Normal processing
4041 Set_Entity (N, Any_Id);
4042 Set_Etype (N, Any_Type);
4044 -- We use the table Urefs to keep track of entities for which we
4045 -- have issued errors for undefined references. Multiple errors
4046 -- for a single name are normally suppressed, however we modify
4047 -- the error message to alert the programmer to this effect.
4049 for J in Urefs.First .. Urefs.Last loop
4050 if Chars (N) = Chars (Urefs.Table (J).Node) then
4051 if Urefs.Table (J).Err /= No_Error_Msg
4052 and then Sloc (N) /= Urefs.Table (J).Loc
4054 Error_Msg_Node_1 := Urefs.Table (J).Node;
4056 if Urefs.Table (J).Nvis then
4057 Change_Error_Text (Urefs.Table (J).Err,
4058 "& is not visible (more references follow)");
4060 Change_Error_Text (Urefs.Table (J).Err,
4061 "& is undefined (more references follow)");
4064 Urefs.Table (J).Err := No_Error_Msg;
4067 -- Although we will set Msg False, and thus suppress the
4068 -- message, we also set Error_Posted True, to avoid any
4069 -- cascaded messages resulting from the undefined reference.
4072 Set_Error_Posted (N, True);
4077 -- If entry not found, this is first undefined occurrence
4080 Error_Msg_N ("& is not visible!", N);
4084 Error_Msg_N ("& is undefined!", N);
4087 -- A very bizarre special check, if the undefined identifier
4088 -- is put or put_line, then add a special error message (since
4089 -- this is a very common error for beginners to make).
4091 if Chars (N) = Name_Put or else Chars (N) = Name_Put_Line then
4092 Error_Msg_N -- CODEFIX
4093 ("\\possible missing `WITH Ada.Text_'I'O; " &
4094 "USE Ada.Text_'I'O`!", N);
4096 -- Another special check if N is the prefix of a selected
4097 -- component which is a known unit, add message complaining
4098 -- about missing with for this unit.
4100 elsif Nkind (Parent (N)) = N_Selected_Component
4101 and then N = Prefix (Parent (N))
4102 and then Is_Known_Unit (Parent (N))
4104 Error_Msg_Node_2 := Selector_Name (Parent (N));
4105 Error_Msg_N -- CODEFIX
4106 ("\\missing `WITH &.&;`", Prefix (Parent (N)));
4109 -- Now check for possible misspellings
4113 Ematch : Entity_Id := Empty;
4115 Last_Name_Id : constant Name_Id :=
4116 Name_Id (Nat (First_Name_Id) +
4117 Name_Entries_Count - 1);
4120 for Nam in First_Name_Id .. Last_Name_Id loop
4121 E := Get_Name_Entity_Id (Nam);
4124 and then (Is_Immediately_Visible (E)
4126 Is_Potentially_Use_Visible (E))
4128 if Is_Bad_Spelling_Of (Chars (N), Nam) then
4135 if Present (Ematch) then
4136 Error_Msg_NE -- CODEFIX
4137 ("\possible misspelling of&", N, Ematch);
4142 -- Make entry in undefined references table unless the full errors
4143 -- switch is set, in which case by refraining from generating the
4144 -- table entry, we guarantee that we get an error message for every
4145 -- undefined reference.
4147 if not All_Errors_Mode then
4158 -- Start of processing for Find_Direct_Name
4161 -- If the entity pointer is already set, this is an internal node, or
4162 -- a node that is analyzed more than once, after a tree modification.
4163 -- In such a case there is no resolution to perform, just set the type.
4165 if Present (Entity (N)) then
4166 if Is_Type (Entity (N)) then
4167 Set_Etype (N, Entity (N));
4171 Entyp : constant Entity_Id := Etype (Entity (N));
4174 -- One special case here. If the Etype field is already set,
4175 -- and references the packed array type corresponding to the
4176 -- etype of the referenced entity, then leave it alone. This
4177 -- happens for trees generated from Exp_Pakd, where expressions
4178 -- can be deliberately "mis-typed" to the packed array type.
4180 if Is_Array_Type (Entyp)
4181 and then Is_Packed (Entyp)
4182 and then Present (Etype (N))
4183 and then Etype (N) = Packed_Array_Type (Entyp)
4187 -- If not that special case, then just reset the Etype
4190 Set_Etype (N, Etype (Entity (N)));
4198 -- Here if Entity pointer was not set, we need full visibility analysis
4199 -- First we generate debugging output if the debug E flag is set.
4201 if Debug_Flag_E then
4202 Write_Str ("Looking for ");
4203 Write_Name (Chars (N));
4207 Homonyms := Current_Entity (N);
4208 Nvis_Entity := False;
4211 while Present (E) loop
4213 -- If entity is immediately visible or potentially use visible, then
4214 -- process the entity and we are done.
4216 if Is_Immediately_Visible (E) then
4217 goto Immediately_Visible_Entity;
4219 elsif Is_Potentially_Use_Visible (E) then
4220 goto Potentially_Use_Visible_Entity;
4222 -- Note if a known but invisible entity encountered
4224 elsif Known_But_Invisible (E) then
4225 Nvis_Entity := True;
4228 -- Move to next entity in chain and continue search
4233 -- If no entries on homonym chain that were potentially visible,
4234 -- and no entities reasonably considered as non-visible, then
4235 -- we have a plain undefined reference, with no additional
4236 -- explanation required!
4238 if not Nvis_Entity then
4239 Undefined (Nvis => False);
4241 -- Otherwise there is at least one entry on the homonym chain that
4242 -- is reasonably considered as being known and non-visible.
4250 -- Processing for a potentially use visible entry found. We must search
4251 -- the rest of the homonym chain for two reasons. First, if there is a
4252 -- directly visible entry, then none of the potentially use-visible
4253 -- entities are directly visible (RM 8.4(10)). Second, we need to check
4254 -- for the case of multiple potentially use-visible entries hiding one
4255 -- another and as a result being non-directly visible (RM 8.4(11)).
4257 <<Potentially_Use_Visible_Entity>> declare
4258 Only_One_Visible : Boolean := True;
4259 All_Overloadable : Boolean := Is_Overloadable (E);
4263 while Present (E2) loop
4264 if Is_Immediately_Visible (E2) then
4266 -- If the use-visible entity comes from the actual for a
4267 -- formal package, it hides a directly visible entity from
4268 -- outside the instance.
4270 if From_Actual_Package (E)
4271 and then Scope_Depth (E2) < Scope_Depth (Inst)
4276 goto Immediately_Visible_Entity;
4279 elsif Is_Potentially_Use_Visible (E2) then
4280 Only_One_Visible := False;
4281 All_Overloadable := All_Overloadable and Is_Overloadable (E2);
4283 -- Ada 2005 (AI-262): Protect against a form of Beaujolais effect
4284 -- that can occur in private_with clauses. Example:
4287 -- private with B; package A is
4288 -- package C is function B return Integer;
4290 -- V1 : Integer := B;
4291 -- private function B return Integer;
4292 -- V2 : Integer := B;
4295 -- V1 resolves to A.B, but V2 resolves to library unit B
4297 elsif Ekind (E2) = E_Function
4298 and then Scope (E2) = Standard_Standard
4299 and then Has_Private_With (E2)
4301 Only_One_Visible := False;
4302 All_Overloadable := False;
4303 Nvis_Is_Private_Subprg := True;
4310 -- On falling through this loop, we have checked that there are no
4311 -- immediately visible entities. Only_One_Visible is set if exactly
4312 -- one potentially use visible entity exists. All_Overloadable is
4313 -- set if all the potentially use visible entities are overloadable.
4314 -- The condition for legality is that either there is one potentially
4315 -- use visible entity, or if there is more than one, then all of them
4316 -- are overloadable.
4318 if Only_One_Visible or All_Overloadable then
4321 -- If there is more than one potentially use-visible entity and at
4322 -- least one of them non-overloadable, we have an error (RM 8.4(11).
4323 -- Note that E points to the first such entity on the homonym list.
4324 -- Special case: if one of the entities is declared in an actual
4325 -- package, it was visible in the generic, and takes precedence over
4326 -- other entities that are potentially use-visible. Same if it is
4327 -- declared in a local instantiation of the current instance.
4332 -- Find current instance
4334 Inst := Current_Scope;
4335 while Present (Inst)
4336 and then Inst /= Standard_Standard
4338 if Is_Generic_Instance (Inst) then
4342 Inst := Scope (Inst);
4346 while Present (E2) loop
4347 if From_Actual_Package (E2)
4349 (Is_Generic_Instance (Scope (E2))
4350 and then Scope_Depth (Scope (E2)) > Scope_Depth (Inst))
4363 Is_Predefined_File_Name (Unit_File_Name (Current_Sem_Unit))
4365 -- A use-clause in the body of a system file creates conflict
4366 -- with some entity in a user scope, while rtsfind is active.
4367 -- Keep only the entity coming from another predefined unit.
4370 while Present (E2) loop
4371 if Is_Predefined_File_Name
4372 (Unit_File_Name (Get_Source_Unit (Sloc (E2))))
4381 -- Entity must exist because predefined unit is correct
4383 raise Program_Error;
4392 -- Come here with E set to the first immediately visible entity on
4393 -- the homonym chain. This is the one we want unless there is another
4394 -- immediately visible entity further on in the chain for an inner
4395 -- scope (RM 8.3(8)).
4397 <<Immediately_Visible_Entity>> declare
4402 -- Find scope level of initial entity. When compiling through
4403 -- Rtsfind, the previous context is not completely invisible, and
4404 -- an outer entity may appear on the chain, whose scope is below
4405 -- the entry for Standard that delimits the current scope stack.
4406 -- Indicate that the level for this spurious entry is outside of
4407 -- the current scope stack.
4409 Level := Scope_Stack.Last;
4411 Scop := Scope_Stack.Table (Level).Entity;
4412 exit when Scop = Scope (E);
4414 exit when Scop = Standard_Standard;
4417 -- Now search remainder of homonym chain for more inner entry
4418 -- If the entity is Standard itself, it has no scope, and we
4419 -- compare it with the stack entry directly.
4422 while Present (E2) loop
4423 if Is_Immediately_Visible (E2) then
4425 -- If a generic package contains a local declaration that
4426 -- has the same name as the generic, there may be a visibility
4427 -- conflict in an instance, where the local declaration must
4428 -- also hide the name of the corresponding package renaming.
4429 -- We check explicitly for a package declared by a renaming,
4430 -- whose renamed entity is an instance that is on the scope
4431 -- stack, and that contains a homonym in the same scope. Once
4432 -- we have found it, we know that the package renaming is not
4433 -- immediately visible, and that the identifier denotes the
4434 -- other entity (and its homonyms if overloaded).
4436 if Scope (E) = Scope (E2)
4437 and then Ekind (E) = E_Package
4438 and then Present (Renamed_Object (E))
4439 and then Is_Generic_Instance (Renamed_Object (E))
4440 and then In_Open_Scopes (Renamed_Object (E))
4441 and then Comes_From_Source (N)
4443 Set_Is_Immediately_Visible (E, False);
4447 for J in Level + 1 .. Scope_Stack.Last loop
4448 if Scope_Stack.Table (J).Entity = Scope (E2)
4449 or else Scope_Stack.Table (J).Entity = E2
4462 -- At the end of that loop, E is the innermost immediately
4463 -- visible entity, so we are all set.
4466 -- Come here with entity found, and stored in E
4470 -- Check violation of No_Wide_Characters restriction
4472 Check_Wide_Character_Restriction (E, N);
4474 -- When distribution features are available (Get_PCS_Name /=
4475 -- Name_No_DSA), a remote access-to-subprogram type is converted
4476 -- into a record type holding whatever information is needed to
4477 -- perform a remote call on an RCI subprogram. In that case we
4478 -- rewrite any occurrence of the RAS type into the equivalent record
4479 -- type here. 'Access attribute references and RAS dereferences are
4480 -- then implemented using specific TSSs. However when distribution is
4481 -- not available (case of Get_PCS_Name = Name_No_DSA), we bypass the
4482 -- generation of these TSSs, and we must keep the RAS type in its
4483 -- original access-to-subprogram form (since all calls through a
4484 -- value of such type will be local anyway in the absence of a PCS).
4486 if Comes_From_Source (N)
4487 and then Is_Remote_Access_To_Subprogram_Type (E)
4488 and then Expander_Active
4489 and then Get_PCS_Name /= Name_No_DSA
4492 New_Occurrence_Of (Equivalent_Type (E), Sloc (N)));
4496 -- Set the entity. Note that the reason we call Set_Entity for the
4497 -- overloadable case, as opposed to Set_Entity_With_Style_Check is
4498 -- that in the overloaded case, the initial call can set the wrong
4499 -- homonym. The call that sets the right homonym is in Sem_Res and
4500 -- that call does use Set_Entity_With_Style_Check, so we don't miss
4503 if Is_Overloadable (E) then
4506 Set_Entity_With_Style_Check (N, E);
4512 Set_Etype (N, Get_Full_View (Etype (E)));
4515 if Debug_Flag_E then
4516 Write_Str (" found ");
4517 Write_Entity_Info (E, " ");
4520 -- If the Ekind of the entity is Void, it means that all homonyms
4521 -- are hidden from all visibility (RM 8.3(5,14-20)). However, this
4522 -- test is skipped if the current scope is a record and the name is
4523 -- a pragma argument expression (case of Atomic and Volatile pragmas
4524 -- and possibly other similar pragmas added later, which are allowed
4525 -- to reference components in the current record).
4527 if Ekind (E) = E_Void
4529 (not Is_Record_Type (Current_Scope)
4530 or else Nkind (Parent (N)) /= N_Pragma_Argument_Association)
4532 Premature_Usage (N);
4534 -- If the entity is overloadable, collect all interpretations of the
4535 -- name for subsequent overload resolution. We optimize a bit here to
4536 -- do this only if we have an overloadable entity that is not on its
4537 -- own on the homonym chain.
4539 elsif Is_Overloadable (E)
4540 and then (Present (Homonym (E)) or else Current_Entity (N) /= E)
4542 Collect_Interps (N);
4544 -- If no homonyms were visible, the entity is unambiguous
4546 if not Is_Overloaded (N) then
4547 if not Is_Actual_Parameter then
4548 Generate_Reference (E, N);
4552 -- Case of non-overloadable entity, set the entity providing that
4553 -- we do not have the case of a discriminant reference within a
4554 -- default expression. Such references are replaced with the
4555 -- corresponding discriminal, which is the formal corresponding to
4556 -- to the discriminant in the initialization procedure.
4559 -- Entity is unambiguous, indicate that it is referenced here
4561 -- For a renaming of an object, always generate simple reference,
4562 -- we don't try to keep track of assignments in this case.
4564 if Is_Object (E) and then Present (Renamed_Object (E)) then
4565 Generate_Reference (E, N);
4567 -- If the renamed entity is a private protected component,
4568 -- reference the original component as well. This needs to be
4569 -- done because the private renamings are installed before any
4570 -- analysis has occurred. Reference to a private component will
4571 -- resolve to the renaming and the original component will be
4572 -- left unreferenced, hence the following.
4574 if Is_Prival (E) then
4575 Generate_Reference (Prival_Link (E), N);
4578 -- One odd case is that we do not want to set the Referenced flag
4579 -- if the entity is a label, and the identifier is the label in
4580 -- the source, since this is not a reference from the point of
4581 -- view of the user.
4583 elsif Nkind (Parent (N)) = N_Label then
4585 R : constant Boolean := Referenced (E);
4588 -- Generate reference unless this is an actual parameter
4589 -- (see comment below)
4591 if Is_Actual_Parameter then
4592 Generate_Reference (E, N);
4593 Set_Referenced (E, R);
4597 -- Normal case, not a label: generate reference
4599 -- ??? It is too early to generate a reference here even if the
4600 -- entity is unambiguous, because the tree is not sufficiently
4601 -- typed at this point for Generate_Reference to determine
4602 -- whether this reference modifies the denoted object (because
4603 -- implicit dereferences cannot be identified prior to full type
4606 -- The Is_Actual_Parameter routine takes care of one of these
4607 -- cases but there are others probably ???
4609 -- If the entity is the LHS of an assignment, and is a variable
4610 -- (rather than a package prefix), we can mark it as a
4611 -- modification right away, to avoid duplicate references.
4614 if not Is_Actual_Parameter then
4616 and then Ekind (E) /= E_Package
4617 and then Ekind (E) /= E_Generic_Package
4619 Generate_Reference (E, N, 'm');
4621 Generate_Reference (E, N);
4625 Check_Nested_Access (E);
4628 Set_Entity_Or_Discriminal (N, E);
4631 end Find_Direct_Name;
4633 ------------------------
4634 -- Find_Expanded_Name --
4635 ------------------------
4637 -- This routine searches the homonym chain of the entity until it finds
4638 -- an entity declared in the scope denoted by the prefix. If the entity
4639 -- is private, it may nevertheless be immediately visible, if we are in
4640 -- the scope of its declaration.
4642 procedure Find_Expanded_Name (N : Node_Id) is
4643 Selector : constant Node_Id := Selector_Name (N);
4644 Candidate : Entity_Id := Empty;
4650 P_Name := Entity (Prefix (N));
4653 -- If the prefix is a renamed package, look for the entity in the
4654 -- original package.
4656 if Ekind (P_Name) = E_Package
4657 and then Present (Renamed_Object (P_Name))
4659 P_Name := Renamed_Object (P_Name);
4661 -- Rewrite node with entity field pointing to renamed object
4663 Rewrite (Prefix (N), New_Copy (Prefix (N)));
4664 Set_Entity (Prefix (N), P_Name);
4666 -- If the prefix is an object of a concurrent type, look for
4667 -- the entity in the associated task or protected type.
4669 elsif Is_Concurrent_Type (Etype (P_Name)) then
4670 P_Name := Etype (P_Name);
4673 Id := Current_Entity (Selector);
4676 Is_New_Candidate : Boolean;
4679 while Present (Id) loop
4680 if Scope (Id) = P_Name then
4682 Is_New_Candidate := True;
4684 -- Ada 2005 (AI-217): Handle shadow entities associated with types
4685 -- declared in limited-withed nested packages. We don't need to
4686 -- handle E_Incomplete_Subtype entities because the entities in
4687 -- the limited view are always E_Incomplete_Type entities (see
4688 -- Build_Limited_Views). Regarding the expression used to evaluate
4689 -- the scope, it is important to note that the limited view also
4690 -- has shadow entities associated nested packages. For this reason
4691 -- the correct scope of the entity is the scope of the real entity
4692 -- The non-limited view may itself be incomplete, in which case
4693 -- get the full view if available.
4695 elsif From_With_Type (Id)
4696 and then Is_Type (Id)
4697 and then Ekind (Id) = E_Incomplete_Type
4698 and then Present (Non_Limited_View (Id))
4699 and then Scope (Non_Limited_View (Id)) = P_Name
4701 Candidate := Get_Full_View (Non_Limited_View (Id));
4702 Is_New_Candidate := True;
4705 Is_New_Candidate := False;
4708 if Is_New_Candidate then
4709 if Is_Child_Unit (Id) then
4710 exit when Is_Visible_Child_Unit (Id)
4711 or else Is_Immediately_Visible (Id);
4714 exit when not Is_Hidden (Id)
4715 or else Is_Immediately_Visible (Id);
4724 and then (Ekind (P_Name) = E_Procedure
4726 Ekind (P_Name) = E_Function)
4727 and then Is_Generic_Instance (P_Name)
4729 -- Expanded name denotes entity in (instance of) generic subprogram.
4730 -- The entity may be in the subprogram instance, or may denote one of
4731 -- the formals, which is declared in the enclosing wrapper package.
4733 P_Name := Scope (P_Name);
4735 Id := Current_Entity (Selector);
4736 while Present (Id) loop
4737 exit when Scope (Id) = P_Name;
4742 if No (Id) or else Chars (Id) /= Chars (Selector) then
4743 Set_Etype (N, Any_Type);
4745 -- If we are looking for an entity defined in System, try to find it
4746 -- in the child package that may have been provided as an extension
4747 -- to System. The Extend_System pragma will have supplied the name of
4748 -- the extension, which may have to be loaded.
4750 if Chars (P_Name) = Name_System
4751 and then Scope (P_Name) = Standard_Standard
4752 and then Present (System_Extend_Unit)
4753 and then Present_System_Aux (N)
4755 Set_Entity (Prefix (N), System_Aux_Id);
4756 Find_Expanded_Name (N);
4759 elsif Nkind (Selector) = N_Operator_Symbol
4760 and then Has_Implicit_Operator (N)
4762 -- There is an implicit instance of the predefined operator in
4763 -- the given scope. The operator entity is defined in Standard.
4764 -- Has_Implicit_Operator makes the node into an Expanded_Name.
4768 elsif Nkind (Selector) = N_Character_Literal
4769 and then Has_Implicit_Character_Literal (N)
4771 -- If there is no literal defined in the scope denoted by the
4772 -- prefix, the literal may belong to (a type derived from)
4773 -- Standard_Character, for which we have no explicit literals.
4778 -- If the prefix is a single concurrent object, use its name in
4779 -- the error message, rather than that of the anonymous type.
4781 if Is_Concurrent_Type (P_Name)
4782 and then Is_Internal_Name (Chars (P_Name))
4784 Error_Msg_Node_2 := Entity (Prefix (N));
4786 Error_Msg_Node_2 := P_Name;
4789 if P_Name = System_Aux_Id then
4790 P_Name := Scope (P_Name);
4791 Set_Entity (Prefix (N), P_Name);
4794 if Present (Candidate) then
4796 -- If we know that the unit is a child unit we can give a more
4797 -- accurate error message.
4799 if Is_Child_Unit (Candidate) then
4801 -- If the candidate is a private child unit and we are in
4802 -- the visible part of a public unit, specialize the error
4803 -- message. There might be a private with_clause for it,
4804 -- but it is not currently active.
4806 if Is_Private_Descendant (Candidate)
4807 and then Ekind (Current_Scope) = E_Package
4808 and then not In_Private_Part (Current_Scope)
4809 and then not Is_Private_Descendant (Current_Scope)
4811 Error_Msg_N ("private child unit& is not visible here",
4814 -- Normal case where we have a missing with for a child unit
4817 Error_Msg_Qual_Level := 99;
4818 Error_Msg_NE -- CODEFIX
4819 ("missing `WITH &;`", Selector, Candidate);
4820 Error_Msg_Qual_Level := 0;
4823 -- Here we don't know that this is a child unit
4826 Error_Msg_NE ("& is not a visible entity of&", N, Selector);
4830 -- Within the instantiation of a child unit, the prefix may
4831 -- denote the parent instance, but the selector has the name
4832 -- of the original child. Find whether we are within the
4833 -- corresponding instance, and get the proper entity, which
4834 -- can only be an enclosing scope.
4837 and then In_Open_Scopes (P_Name)
4838 and then Is_Generic_Instance (P_Name)
4841 S : Entity_Id := Current_Scope;
4845 for J in reverse 0 .. Scope_Stack.Last loop
4846 S := Scope_Stack.Table (J).Entity;
4848 exit when S = Standard_Standard;
4850 if Ekind_In (S, E_Function,
4854 P := Generic_Parent (Specification
4855 (Unit_Declaration_Node (S)));
4858 and then Chars (Scope (P)) = Chars (O_Name)
4859 and then Chars (P) = Chars (Selector)
4870 -- If this is a selection from Ada, System or Interfaces, then
4871 -- we assume a missing with for the corresponding package.
4873 if Is_Known_Unit (N) then
4874 if not Error_Posted (N) then
4875 Error_Msg_Node_2 := Selector;
4876 Error_Msg_N -- CODEFIX
4877 ("missing `WITH &.&;`", Prefix (N));
4880 -- If this is a selection from a dummy package, then suppress
4881 -- the error message, of course the entity is missing if the
4882 -- package is missing!
4884 elsif Sloc (Error_Msg_Node_2) = No_Location then
4887 -- Here we have the case of an undefined component
4891 -- The prefix may hide a homonym in the context that
4892 -- declares the desired entity. This error can use a
4893 -- specialized message.
4895 if In_Open_Scopes (P_Name)
4896 and then Present (Homonym (P_Name))
4897 and then Is_Compilation_Unit (Homonym (P_Name))
4899 (Is_Immediately_Visible (Homonym (P_Name))
4900 or else Is_Visible_Child_Unit (Homonym (P_Name)))
4903 H : constant Entity_Id := Homonym (P_Name);
4906 Id := First_Entity (H);
4907 while Present (Id) loop
4908 if Chars (Id) = Chars (Selector) then
4909 Error_Msg_Qual_Level := 99;
4910 Error_Msg_Name_1 := Chars (Selector);
4912 ("% not declared in&", N, P_Name);
4914 ("\use fully qualified name starting with"
4915 & " Standard to make& visible", N, H);
4916 Error_Msg_Qual_Level := 0;
4923 -- If not found, standard error message.
4925 Error_Msg_NE ("& not declared in&", N, Selector);
4931 Error_Msg_NE ("& not declared in&", N, Selector);
4934 -- Check for misspelling of some entity in prefix
4936 Id := First_Entity (P_Name);
4937 while Present (Id) loop
4938 if Is_Bad_Spelling_Of (Chars (Id), Chars (Selector))
4939 and then not Is_Internal_Name (Chars (Id))
4941 Error_Msg_NE -- CODEFIX
4942 ("possible misspelling of&", Selector, Id);
4949 -- Specialize the message if this may be an instantiation
4950 -- of a child unit that was not mentioned in the context.
4952 if Nkind (Parent (N)) = N_Package_Instantiation
4953 and then Is_Generic_Instance (Entity (Prefix (N)))
4954 and then Is_Compilation_Unit
4955 (Generic_Parent (Parent (Entity (Prefix (N)))))
4957 Error_Msg_Node_2 := Selector;
4958 Error_Msg_N -- CODEFIX
4959 ("\missing `WITH &.&;`", Prefix (N));
4969 if Comes_From_Source (N)
4970 and then Is_Remote_Access_To_Subprogram_Type (Id)
4971 and then Present (Equivalent_Type (Id))
4973 -- If we are not actually generating distribution code (i.e. the
4974 -- current PCS is the dummy non-distributed version), then the
4975 -- Equivalent_Type will be missing, and Id should be treated as
4976 -- a regular access-to-subprogram type.
4978 Id := Equivalent_Type (Id);
4979 Set_Chars (Selector, Chars (Id));
4982 -- Ada 2005 (AI-50217): Check usage of entities in limited withed units
4984 if Ekind (P_Name) = E_Package
4985 and then From_With_Type (P_Name)
4987 if From_With_Type (Id)
4988 or else Is_Type (Id)
4989 or else Ekind (Id) = E_Package
4994 ("limited withed package can only be used to access "
4995 & "incomplete types",
5000 if Is_Task_Type (P_Name)
5001 and then ((Ekind (Id) = E_Entry
5002 and then Nkind (Parent (N)) /= N_Attribute_Reference)
5004 (Ekind (Id) = E_Entry_Family
5006 Nkind (Parent (Parent (N))) /= N_Attribute_Reference))
5008 -- It is an entry call after all, either to the current task (which
5009 -- will deadlock) or to an enclosing task.
5011 Analyze_Selected_Component (N);
5015 Change_Selected_Component_To_Expanded_Name (N);
5017 -- Do style check and generate reference, but skip both steps if this
5018 -- entity has homonyms, since we may not have the right homonym set yet.
5019 -- The proper homonym will be set during the resolve phase.
5021 if Has_Homonym (Id) then
5024 Set_Entity_Or_Discriminal (N, Id);
5027 Generate_Reference (Id, N, 'm');
5029 Generate_Reference (Id, N);
5033 if Is_Type (Id) then
5036 Set_Etype (N, Get_Full_View (Etype (Id)));
5039 -- Check for violation of No_Wide_Characters
5041 Check_Wide_Character_Restriction (Id, N);
5043 -- If the Ekind of the entity is Void, it means that all homonyms are
5044 -- hidden from all visibility (RM 8.3(5,14-20)).
5046 if Ekind (Id) = E_Void then
5047 Premature_Usage (N);
5049 elsif Is_Overloadable (Id)
5050 and then Present (Homonym (Id))
5053 H : Entity_Id := Homonym (Id);
5056 while Present (H) loop
5057 if Scope (H) = Scope (Id)
5060 or else Is_Immediately_Visible (H))
5062 Collect_Interps (N);
5069 -- If an extension of System is present, collect possible explicit
5070 -- overloadings declared in the extension.
5072 if Chars (P_Name) = Name_System
5073 and then Scope (P_Name) = Standard_Standard
5074 and then Present (System_Extend_Unit)
5075 and then Present_System_Aux (N)
5077 H := Current_Entity (Id);
5079 while Present (H) loop
5080 if Scope (H) = System_Aux_Id then
5081 Add_One_Interp (N, H, Etype (H));
5090 if Nkind (Selector_Name (N)) = N_Operator_Symbol
5091 and then Scope (Id) /= Standard_Standard
5093 -- In addition to user-defined operators in the given scope, there
5094 -- may be an implicit instance of the predefined operator. The
5095 -- operator (defined in Standard) is found in Has_Implicit_Operator,
5096 -- and added to the interpretations. Procedure Add_One_Interp will
5097 -- determine which hides which.
5099 if Has_Implicit_Operator (N) then
5103 end Find_Expanded_Name;
5105 -------------------------
5106 -- Find_Renamed_Entity --
5107 -------------------------
5109 function Find_Renamed_Entity
5113 Is_Actual : Boolean := False) return Entity_Id
5116 I1 : Interp_Index := 0; -- Suppress junk warnings
5122 function Enclosing_Instance return Entity_Id;
5123 -- If the renaming determines the entity for the default of a formal
5124 -- subprogram nested within another instance, choose the innermost
5125 -- candidate. This is because if the formal has a box, and we are within
5126 -- an enclosing instance where some candidate interpretations are local
5127 -- to this enclosing instance, we know that the default was properly
5128 -- resolved when analyzing the generic, so we prefer the local
5129 -- candidates to those that are external. This is not always the case
5130 -- but is a reasonable heuristic on the use of nested generics. The
5131 -- proper solution requires a full renaming model.
5133 function Is_Visible_Operation (Op : Entity_Id) return Boolean;
5134 -- If the renamed entity is an implicit operator, check whether it is
5135 -- visible because its operand type is properly visible. This check
5136 -- applies to explicit renamed entities that appear in the source in a
5137 -- renaming declaration or a formal subprogram instance, but not to
5138 -- default generic actuals with a name.
5140 function Report_Overload return Entity_Id;
5141 -- List possible interpretations, and specialize message in the
5142 -- case of a generic actual.
5144 function Within (Inner, Outer : Entity_Id) return Boolean;
5145 -- Determine whether a candidate subprogram is defined within the
5146 -- enclosing instance. If yes, it has precedence over outer candidates.
5148 ------------------------
5149 -- Enclosing_Instance --
5150 ------------------------
5152 function Enclosing_Instance return Entity_Id is
5156 if not Is_Generic_Instance (Current_Scope)
5157 and then not Is_Actual
5162 S := Scope (Current_Scope);
5163 while S /= Standard_Standard loop
5164 if Is_Generic_Instance (S) then
5172 end Enclosing_Instance;
5174 --------------------------
5175 -- Is_Visible_Operation --
5176 --------------------------
5178 function Is_Visible_Operation (Op : Entity_Id) return Boolean is
5184 if Ekind (Op) /= E_Operator
5185 or else Scope (Op) /= Standard_Standard
5186 or else (In_Instance
5189 or else Present (Enclosing_Instance)))
5194 -- For a fixed point type operator, check the resulting type,
5195 -- because it may be a mixed mode integer * fixed operation.
5197 if Present (Next_Formal (First_Formal (New_S)))
5198 and then Is_Fixed_Point_Type (Etype (New_S))
5200 Typ := Etype (New_S);
5202 Typ := Etype (First_Formal (New_S));
5205 Btyp := Base_Type (Typ);
5207 if Nkind (Nam) /= N_Expanded_Name then
5208 return (In_Open_Scopes (Scope (Btyp))
5209 or else Is_Potentially_Use_Visible (Btyp)
5210 or else In_Use (Btyp)
5211 or else In_Use (Scope (Btyp)));
5214 Scop := Entity (Prefix (Nam));
5216 if Ekind (Scop) = E_Package
5217 and then Present (Renamed_Object (Scop))
5219 Scop := Renamed_Object (Scop);
5222 -- Operator is visible if prefix of expanded name denotes
5223 -- scope of type, or else type is defined in System_Aux
5224 -- and the prefix denotes System.
5226 return Scope (Btyp) = Scop
5227 or else (Scope (Btyp) = System_Aux_Id
5228 and then Scope (Scope (Btyp)) = Scop);
5231 end Is_Visible_Operation;
5237 function Within (Inner, Outer : Entity_Id) return Boolean is
5241 Sc := Scope (Inner);
5242 while Sc /= Standard_Standard loop
5253 ---------------------
5254 -- Report_Overload --
5255 ---------------------
5257 function Report_Overload return Entity_Id is
5260 Error_Msg_NE -- CODEFIX
5261 ("ambiguous actual subprogram&, " &
5262 "possible interpretations:", N, Nam);
5264 Error_Msg_N -- CODEFIX
5265 ("ambiguous subprogram, " &
5266 "possible interpretations:", N);
5269 List_Interps (Nam, N);
5271 end Report_Overload;
5273 -- Start of processing for Find_Renamed_Entry
5277 Candidate_Renaming := Empty;
5279 if not Is_Overloaded (Nam) then
5280 if Entity_Matches_Spec (Entity (Nam), New_S) then
5281 Candidate_Renaming := New_S;
5283 if Is_Visible_Operation (Entity (Nam)) then
5284 Old_S := Entity (Nam);
5288 Present (First_Formal (Entity (Nam)))
5289 and then Present (First_Formal (New_S))
5290 and then (Base_Type (Etype (First_Formal (Entity (Nam))))
5291 = Base_Type (Etype (First_Formal (New_S))))
5293 Candidate_Renaming := Entity (Nam);
5297 Get_First_Interp (Nam, Ind, It);
5298 while Present (It.Nam) loop
5299 if Entity_Matches_Spec (It.Nam, New_S)
5300 and then Is_Visible_Operation (It.Nam)
5302 if Old_S /= Any_Id then
5304 -- Note: The call to Disambiguate only happens if a
5305 -- previous interpretation was found, in which case I1
5306 -- has received a value.
5308 It1 := Disambiguate (Nam, I1, Ind, Etype (Old_S));
5310 if It1 = No_Interp then
5311 Inst := Enclosing_Instance;
5313 if Present (Inst) then
5314 if Within (It.Nam, Inst) then
5316 elsif Within (Old_S, Inst) then
5319 return Report_Overload;
5323 return Report_Overload;
5337 Present (First_Formal (It.Nam))
5338 and then Present (First_Formal (New_S))
5339 and then (Base_Type (Etype (First_Formal (It.Nam)))
5340 = Base_Type (Etype (First_Formal (New_S))))
5342 Candidate_Renaming := It.Nam;
5345 Get_Next_Interp (Ind, It);
5348 Set_Entity (Nam, Old_S);
5349 Set_Is_Overloaded (Nam, False);
5353 end Find_Renamed_Entity;
5355 -----------------------------
5356 -- Find_Selected_Component --
5357 -----------------------------
5359 procedure Find_Selected_Component (N : Node_Id) is
5360 P : constant Node_Id := Prefix (N);
5363 -- Entity denoted by prefix
5373 if Nkind (P) = N_Error then
5376 -- If the selector already has an entity, the node has been constructed
5377 -- in the course of expansion, and is known to be valid. Do not verify
5378 -- that it is defined for the type (it may be a private component used
5379 -- in the expansion of record equality).
5381 elsif Present (Entity (Selector_Name (N))) then
5383 or else Etype (N) = Any_Type
5386 Sel_Name : constant Node_Id := Selector_Name (N);
5387 Selector : constant Entity_Id := Entity (Sel_Name);
5391 Set_Etype (Sel_Name, Etype (Selector));
5393 if not Is_Entity_Name (P) then
5397 -- Build an actual subtype except for the first parameter
5398 -- of an init proc, where this actual subtype is by
5399 -- definition incorrect, since the object is uninitialized
5400 -- (and does not even have defined discriminants etc.)
5402 if Is_Entity_Name (P)
5403 and then Ekind (Entity (P)) = E_Function
5405 Nam := New_Copy (P);
5407 if Is_Overloaded (P) then
5408 Save_Interps (P, Nam);
5412 Make_Function_Call (Sloc (P), Name => Nam));
5414 Analyze_Selected_Component (N);
5417 elsif Ekind (Selector) = E_Component
5418 and then (not Is_Entity_Name (P)
5419 or else Chars (Entity (P)) /= Name_uInit)
5421 -- Do not build the subtype when referencing components of
5422 -- dispatch table wrappers. Required to avoid generating
5423 -- elaboration code with HI runtimes.
5425 if RTU_Loaded (Ada_Tags)
5426 and then RTE_Available (RE_Dispatch_Table_Wrapper)
5427 and then Scope (Selector) = RTE (RE_Dispatch_Table_Wrapper)
5431 elsif RTU_Loaded (Ada_Tags)
5432 and then RTE_Available (RE_No_Dispatch_Table_Wrapper)
5433 and then Scope (Selector)
5434 = RTE (RE_No_Dispatch_Table_Wrapper)
5440 Build_Actual_Subtype_Of_Component (
5441 Etype (Selector), N);
5448 if No (C_Etype) then
5449 C_Etype := Etype (Selector);
5451 Insert_Action (N, C_Etype);
5452 C_Etype := Defining_Identifier (C_Etype);
5455 Set_Etype (N, C_Etype);
5458 -- If this is the name of an entry or protected operation, and
5459 -- the prefix is an access type, insert an explicit dereference,
5460 -- so that entry calls are treated uniformly.
5462 if Is_Access_Type (Etype (P))
5463 and then Is_Concurrent_Type (Designated_Type (Etype (P)))
5466 New_P : constant Node_Id :=
5467 Make_Explicit_Dereference (Sloc (P),
5468 Prefix => Relocate_Node (P));
5471 Set_Etype (P, Designated_Type (Etype (Prefix (P))));
5475 -- If the selected component appears within a default expression
5476 -- and it has an actual subtype, the pre-analysis has not yet
5477 -- completed its analysis, because Insert_Actions is disabled in
5478 -- that context. Within the init proc of the enclosing type we
5479 -- must complete this analysis, if an actual subtype was created.
5481 elsif Inside_Init_Proc then
5483 Typ : constant Entity_Id := Etype (N);
5484 Decl : constant Node_Id := Declaration_Node (Typ);
5486 if Nkind (Decl) = N_Subtype_Declaration
5487 and then not Analyzed (Decl)
5488 and then Is_List_Member (Decl)
5489 and then No (Parent (Decl))
5492 Insert_Action (N, Decl);
5499 elsif Is_Entity_Name (P) then
5500 P_Name := Entity (P);
5502 -- Selector name is restricted in SPARK
5505 if Is_Subprogram (P_Name) then
5507 ("|~~prefix of expanded name cannot be a subprogram", P);
5508 elsif Ekind (P_Name) = E_Loop then
5510 ("|~~prefix of expanded name cannot be a loop statement", P);
5514 -- The prefix may denote an enclosing type which is the completion
5515 -- of an incomplete type declaration.
5517 if Is_Type (P_Name) then
5518 Set_Entity (P, Get_Full_View (P_Name));
5519 Set_Etype (P, Entity (P));
5520 P_Name := Entity (P);
5523 P_Type := Base_Type (Etype (P));
5525 if Debug_Flag_E then
5526 Write_Str ("Found prefix type to be ");
5527 Write_Entity_Info (P_Type, " "); Write_Eol;
5530 -- First check for components of a record object (not the
5531 -- result of a call, which is handled below).
5533 if Is_Appropriate_For_Record (P_Type)
5534 and then not Is_Overloadable (P_Name)
5535 and then not Is_Type (P_Name)
5537 -- Selected component of record. Type checking will validate
5538 -- name of selector.
5539 -- ??? could we rewrite an implicit dereference into an explicit
5542 Analyze_Selected_Component (N);
5544 -- Reference to type name in predicate/invariant expression
5546 elsif Is_Appropriate_For_Entry_Prefix (P_Type)
5547 and then not In_Open_Scopes (P_Name)
5548 and then (not Is_Concurrent_Type (Etype (P_Name))
5549 or else not In_Open_Scopes (Etype (P_Name)))
5551 -- Call to protected operation or entry. Type checking is
5552 -- needed on the prefix.
5554 Analyze_Selected_Component (N);
5556 elsif (In_Open_Scopes (P_Name)
5557 and then Ekind (P_Name) /= E_Void
5558 and then not Is_Overloadable (P_Name))
5559 or else (Is_Concurrent_Type (Etype (P_Name))
5560 and then In_Open_Scopes (Etype (P_Name)))
5562 -- Prefix denotes an enclosing loop, block, or task, i.e. an
5563 -- enclosing construct that is not a subprogram or accept.
5565 Find_Expanded_Name (N);
5567 elsif Ekind (P_Name) = E_Package then
5568 Find_Expanded_Name (N);
5570 elsif Is_Overloadable (P_Name) then
5572 -- The subprogram may be a renaming (of an enclosing scope) as
5573 -- in the case of the name of the generic within an instantiation.
5575 if Ekind_In (P_Name, E_Procedure, E_Function)
5576 and then Present (Alias (P_Name))
5577 and then Is_Generic_Instance (Alias (P_Name))
5579 P_Name := Alias (P_Name);
5582 if Is_Overloaded (P) then
5584 -- The prefix must resolve to a unique enclosing construct
5587 Found : Boolean := False;
5592 Get_First_Interp (P, Ind, It);
5593 while Present (It.Nam) loop
5594 if In_Open_Scopes (It.Nam) then
5597 "prefix must be unique enclosing scope", N);
5598 Set_Entity (N, Any_Id);
5599 Set_Etype (N, Any_Type);
5608 Get_Next_Interp (Ind, It);
5613 if In_Open_Scopes (P_Name) then
5614 Set_Entity (P, P_Name);
5615 Set_Is_Overloaded (P, False);
5616 Find_Expanded_Name (N);
5619 -- If no interpretation as an expanded name is possible, it
5620 -- must be a selected component of a record returned by a
5621 -- function call. Reformat prefix as a function call, the rest
5622 -- is done by type resolution. If the prefix is procedure or
5623 -- entry, as is P.X; this is an error.
5625 if Ekind (P_Name) /= E_Function
5626 and then (not Is_Overloaded (P)
5628 Nkind (Parent (N)) = N_Procedure_Call_Statement)
5630 -- Prefix may mention a package that is hidden by a local
5631 -- declaration: let the user know. Scan the full homonym
5632 -- chain, the candidate package may be anywhere on it.
5634 if Present (Homonym (Current_Entity (P_Name))) then
5636 P_Name := Current_Entity (P_Name);
5638 while Present (P_Name) loop
5639 exit when Ekind (P_Name) = E_Package;
5640 P_Name := Homonym (P_Name);
5643 if Present (P_Name) then
5644 Error_Msg_Sloc := Sloc (Entity (Prefix (N)));
5647 ("package& is hidden by declaration#",
5650 Set_Entity (Prefix (N), P_Name);
5651 Find_Expanded_Name (N);
5654 P_Name := Entity (Prefix (N));
5659 ("invalid prefix in selected component&", N, P_Name);
5660 Change_Selected_Component_To_Expanded_Name (N);
5661 Set_Entity (N, Any_Id);
5662 Set_Etype (N, Any_Type);
5665 Nam := New_Copy (P);
5666 Save_Interps (P, Nam);
5668 Make_Function_Call (Sloc (P), Name => Nam));
5670 Analyze_Selected_Component (N);
5674 -- Remaining cases generate various error messages
5677 -- Format node as expanded name, to avoid cascaded errors
5679 Change_Selected_Component_To_Expanded_Name (N);
5680 Set_Entity (N, Any_Id);
5681 Set_Etype (N, Any_Type);
5683 -- Issue error message, but avoid this if error issued already.
5684 -- Use identifier of prefix if one is available.
5686 if P_Name = Any_Id then
5689 elsif Ekind (P_Name) = E_Void then
5690 Premature_Usage (P);
5692 elsif Nkind (P) /= N_Attribute_Reference then
5694 "invalid prefix in selected component&", P);
5696 if Is_Access_Type (P_Type)
5697 and then Ekind (Designated_Type (P_Type)) = E_Incomplete_Type
5700 ("\dereference must not be of an incomplete type " &
5706 "invalid prefix in selected component", P);
5711 -- If prefix is not the name of an entity, it must be an expression,
5712 -- whose type is appropriate for a record. This is determined by
5715 Analyze_Selected_Component (N);
5717 end Find_Selected_Component;
5723 procedure Find_Type (N : Node_Id) is
5733 elsif Nkind (N) = N_Attribute_Reference then
5735 -- Class attribute. This is not valid in Ada 83 mode, but we do not
5736 -- need to enforce that at this point, since the declaration of the
5737 -- tagged type in the prefix would have been flagged already.
5739 if Attribute_Name (N) = Name_Class then
5740 Check_Restriction (No_Dispatch, N);
5741 Find_Type (Prefix (N));
5743 -- Propagate error from bad prefix
5745 if Etype (Prefix (N)) = Any_Type then
5746 Set_Entity (N, Any_Type);
5747 Set_Etype (N, Any_Type);
5751 T := Base_Type (Entity (Prefix (N)));
5753 -- Case where type is not known to be tagged. Its appearance in
5754 -- the prefix of the 'Class attribute indicates that the full view
5757 if not Is_Tagged_Type (T) then
5758 if Ekind (T) = E_Incomplete_Type then
5760 -- It is legal to denote the class type of an incomplete
5761 -- type. The full type will have to be tagged, of course.
5762 -- In Ada 2005 this usage is declared obsolescent, so we
5763 -- warn accordingly. This usage is only legal if the type
5764 -- is completed in the current scope, and not for a limited
5767 if not Is_Tagged_Type (T)
5768 and then Ada_Version >= Ada_2005
5770 if From_With_Type (T) then
5772 ("prefix of Class attribute must be tagged", N);
5773 Set_Etype (N, Any_Type);
5774 Set_Entity (N, Any_Type);
5777 -- ??? This test is temporarily disabled (always False)
5778 -- because it causes an unwanted warning on GNAT sources
5779 -- (built with -gnatg, which includes Warn_On_Obsolescent_
5780 -- Feature). Once this issue is cleared in the sources, it
5783 elsif Warn_On_Obsolescent_Feature
5787 ("applying 'Class to an untagged incomplete type"
5788 & " is an obsolescent feature (RM J.11)", N);
5792 Set_Is_Tagged_Type (T);
5793 Set_Direct_Primitive_Operations (T, New_Elmt_List);
5794 Make_Class_Wide_Type (T);
5795 Set_Entity (N, Class_Wide_Type (T));
5796 Set_Etype (N, Class_Wide_Type (T));
5798 elsif Ekind (T) = E_Private_Type
5799 and then not Is_Generic_Type (T)
5800 and then In_Private_Part (Scope (T))
5802 -- The Class attribute can be applied to an untagged private
5803 -- type fulfilled by a tagged type prior to the full type
5804 -- declaration (but only within the parent package's private
5805 -- part). Create the class-wide type now and check that the
5806 -- full type is tagged later during its analysis. Note that
5807 -- we do not mark the private type as tagged, unlike the
5808 -- case of incomplete types, because the type must still
5809 -- appear untagged to outside units.
5811 if No (Class_Wide_Type (T)) then
5812 Make_Class_Wide_Type (T);
5815 Set_Entity (N, Class_Wide_Type (T));
5816 Set_Etype (N, Class_Wide_Type (T));
5819 -- Should we introduce a type Any_Tagged and use Wrong_Type
5820 -- here, it would be a bit more consistent???
5823 ("tagged type required, found}",
5824 Prefix (N), First_Subtype (T));
5825 Set_Entity (N, Any_Type);
5829 -- Case of tagged type
5832 if Is_Concurrent_Type (T) then
5833 if No (Corresponding_Record_Type (Entity (Prefix (N)))) then
5835 -- Previous error. Use current type, which at least
5836 -- provides some operations.
5838 C := Entity (Prefix (N));
5841 C := Class_Wide_Type
5842 (Corresponding_Record_Type (Entity (Prefix (N))));
5846 C := Class_Wide_Type (Entity (Prefix (N)));
5849 Set_Entity_With_Style_Check (N, C);
5850 Generate_Reference (C, N);
5854 -- Base attribute, not allowed in Ada 83
5856 elsif Attribute_Name (N) = Name_Base then
5857 if Ada_Version = Ada_83 and then Comes_From_Source (N) then
5859 ("(Ada 83) Base attribute not allowed in subtype mark", N);
5862 Find_Type (Prefix (N));
5863 Typ := Entity (Prefix (N));
5865 if Ada_Version >= Ada_95
5866 and then not Is_Scalar_Type (Typ)
5867 and then not Is_Generic_Type (Typ)
5870 ("prefix of Base attribute must be scalar type",
5873 elsif Warn_On_Redundant_Constructs
5874 and then Base_Type (Typ) = Typ
5876 Error_Msg_NE -- CODEFIX
5877 ("?redundant attribute, & is its own base type", N, Typ);
5880 T := Base_Type (Typ);
5882 -- Rewrite attribute reference with type itself (see similar
5883 -- processing in Analyze_Attribute, case Base). Preserve prefix
5884 -- if present, for other legality checks.
5886 if Nkind (Prefix (N)) = N_Expanded_Name then
5888 Make_Expanded_Name (Sloc (N),
5890 Prefix => New_Copy (Prefix (Prefix (N))),
5891 Selector_Name => New_Reference_To (T, Sloc (N))));
5894 Rewrite (N, New_Reference_To (T, Sloc (N)));
5901 elsif Attribute_Name (N) = Name_Stub_Type then
5903 -- This is handled in Analyze_Attribute
5907 -- All other attributes are invalid in a subtype mark
5910 Error_Msg_N ("invalid attribute in subtype mark", N);
5916 if Is_Entity_Name (N) then
5917 T_Name := Entity (N);
5919 Error_Msg_N ("subtype mark required in this context", N);
5920 Set_Etype (N, Any_Type);
5924 if T_Name = Any_Id or else Etype (N) = Any_Type then
5926 -- Undefined id. Make it into a valid type
5928 Set_Entity (N, Any_Type);
5930 elsif not Is_Type (T_Name)
5931 and then T_Name /= Standard_Void_Type
5933 Error_Msg_Sloc := Sloc (T_Name);
5934 Error_Msg_N ("subtype mark required in this context", N);
5935 Error_Msg_NE ("\\found & declared#", N, T_Name);
5936 Set_Entity (N, Any_Type);
5939 -- If the type is an incomplete type created to handle
5940 -- anonymous access components of a record type, then the
5941 -- incomplete type is the visible entity and subsequent
5942 -- references will point to it. Mark the original full
5943 -- type as referenced, to prevent spurious warnings.
5945 if Is_Incomplete_Type (T_Name)
5946 and then Present (Full_View (T_Name))
5947 and then not Comes_From_Source (T_Name)
5949 Set_Referenced (Full_View (T_Name));
5952 T_Name := Get_Full_View (T_Name);
5954 -- Ada 2005 (AI-251, AI-50217): Handle interfaces visible through
5955 -- limited-with clauses
5957 if From_With_Type (T_Name)
5958 and then Ekind (T_Name) in Incomplete_Kind
5959 and then Present (Non_Limited_View (T_Name))
5960 and then Is_Interface (Non_Limited_View (T_Name))
5962 T_Name := Non_Limited_View (T_Name);
5965 if In_Open_Scopes (T_Name) then
5966 if Ekind (Base_Type (T_Name)) = E_Task_Type then
5968 -- In Ada 2005, a task name can be used in an access
5969 -- definition within its own body. It cannot be used
5970 -- in the discriminant part of the task declaration,
5971 -- nor anywhere else in the declaration because entries
5972 -- cannot have access parameters.
5974 if Ada_Version >= Ada_2005
5975 and then Nkind (Parent (N)) = N_Access_Definition
5977 Set_Entity (N, T_Name);
5978 Set_Etype (N, T_Name);
5980 if Has_Completion (T_Name) then
5985 ("task type cannot be used as type mark " &
5986 "within its own declaration", N);
5991 ("task type cannot be used as type mark " &
5992 "within its own spec or body", N);
5995 elsif Ekind (Base_Type (T_Name)) = E_Protected_Type then
5997 -- In Ada 2005, a protected name can be used in an access
5998 -- definition within its own body.
6000 if Ada_Version >= Ada_2005
6001 and then Nkind (Parent (N)) = N_Access_Definition
6003 Set_Entity (N, T_Name);
6004 Set_Etype (N, T_Name);
6009 ("protected type cannot be used as type mark " &
6010 "within its own spec or body", N);
6014 Error_Msg_N ("type declaration cannot refer to itself", N);
6017 Set_Etype (N, Any_Type);
6018 Set_Entity (N, Any_Type);
6019 Set_Error_Posted (T_Name);
6023 Set_Entity (N, T_Name);
6024 Set_Etype (N, T_Name);
6028 if Present (Etype (N)) and then Comes_From_Source (N) then
6029 if Is_Fixed_Point_Type (Etype (N)) then
6030 Check_Restriction (No_Fixed_Point, N);
6031 elsif Is_Floating_Point_Type (Etype (N)) then
6032 Check_Restriction (No_Floating_Point, N);
6037 ------------------------------------
6038 -- Has_Implicit_Character_Literal --
6039 ------------------------------------
6041 function Has_Implicit_Character_Literal (N : Node_Id) return Boolean is
6043 Found : Boolean := False;
6044 P : constant Entity_Id := Entity (Prefix (N));
6045 Priv_Id : Entity_Id := Empty;
6048 if Ekind (P) = E_Package
6049 and then not In_Open_Scopes (P)
6051 Priv_Id := First_Private_Entity (P);
6054 if P = Standard_Standard then
6055 Change_Selected_Component_To_Expanded_Name (N);
6056 Rewrite (N, Selector_Name (N));
6058 Set_Etype (Original_Node (N), Standard_Character);
6062 Id := First_Entity (P);
6064 and then Id /= Priv_Id
6066 if Is_Standard_Character_Type (Id) and then Is_Base_Type (Id) then
6068 -- We replace the node with the literal itself, resolve as a
6069 -- character, and set the type correctly.
6072 Change_Selected_Component_To_Expanded_Name (N);
6073 Rewrite (N, Selector_Name (N));
6076 Set_Etype (Original_Node (N), Id);
6080 -- More than one type derived from Character in given scope.
6081 -- Collect all possible interpretations.
6083 Add_One_Interp (N, Id, Id);
6091 end Has_Implicit_Character_Literal;
6093 ----------------------
6094 -- Has_Private_With --
6095 ----------------------
6097 function Has_Private_With (E : Entity_Id) return Boolean is
6098 Comp_Unit : constant Node_Id := Cunit (Current_Sem_Unit);
6102 Item := First (Context_Items (Comp_Unit));
6103 while Present (Item) loop
6104 if Nkind (Item) = N_With_Clause
6105 and then Private_Present (Item)
6106 and then Entity (Name (Item)) = E
6115 end Has_Private_With;
6117 ---------------------------
6118 -- Has_Implicit_Operator --
6119 ---------------------------
6121 function Has_Implicit_Operator (N : Node_Id) return Boolean is
6122 Op_Id : constant Name_Id := Chars (Selector_Name (N));
6123 P : constant Entity_Id := Entity (Prefix (N));
6125 Priv_Id : Entity_Id := Empty;
6127 procedure Add_Implicit_Operator
6129 Op_Type : Entity_Id := Empty);
6130 -- Add implicit interpretation to node N, using the type for which a
6131 -- predefined operator exists. If the operator yields a boolean type,
6132 -- the Operand_Type is implicitly referenced by the operator, and a
6133 -- reference to it must be generated.
6135 ---------------------------
6136 -- Add_Implicit_Operator --
6137 ---------------------------
6139 procedure Add_Implicit_Operator
6141 Op_Type : Entity_Id := Empty)
6143 Predef_Op : Entity_Id;
6146 Predef_Op := Current_Entity (Selector_Name (N));
6148 while Present (Predef_Op)
6149 and then Scope (Predef_Op) /= Standard_Standard
6151 Predef_Op := Homonym (Predef_Op);
6154 if Nkind (N) = N_Selected_Component then
6155 Change_Selected_Component_To_Expanded_Name (N);
6158 -- If the context is an unanalyzed function call, determine whether
6159 -- a binary or unary interpretation is required.
6161 if Nkind (Parent (N)) = N_Indexed_Component then
6163 Is_Binary_Call : constant Boolean :=
6165 (Next (First (Expressions (Parent (N)))));
6166 Is_Binary_Op : constant Boolean :=
6168 (Predef_Op) /= Last_Entity (Predef_Op);
6169 Predef_Op2 : constant Entity_Id := Homonym (Predef_Op);
6172 if Is_Binary_Call then
6173 if Is_Binary_Op then
6174 Add_One_Interp (N, Predef_Op, T);
6176 Add_One_Interp (N, Predef_Op2, T);
6180 if not Is_Binary_Op then
6181 Add_One_Interp (N, Predef_Op, T);
6183 Add_One_Interp (N, Predef_Op2, T);
6189 Add_One_Interp (N, Predef_Op, T);
6191 -- For operators with unary and binary interpretations, if
6192 -- context is not a call, add both
6194 if Present (Homonym (Predef_Op)) then
6195 Add_One_Interp (N, Homonym (Predef_Op), T);
6199 -- The node is a reference to a predefined operator, and
6200 -- an implicit reference to the type of its operands.
6202 if Present (Op_Type) then
6203 Generate_Operator_Reference (N, Op_Type);
6205 Generate_Operator_Reference (N, T);
6207 end Add_Implicit_Operator;
6209 -- Start of processing for Has_Implicit_Operator
6212 if Ekind (P) = E_Package
6213 and then not In_Open_Scopes (P)
6215 Priv_Id := First_Private_Entity (P);
6218 Id := First_Entity (P);
6222 -- Boolean operators: an implicit declaration exists if the scope
6223 -- contains a declaration for a derived Boolean type, or for an
6224 -- array of Boolean type.
6226 when Name_Op_And | Name_Op_Not | Name_Op_Or | Name_Op_Xor =>
6227 while Id /= Priv_Id loop
6228 if Valid_Boolean_Arg (Id) and then Is_Base_Type (Id) then
6229 Add_Implicit_Operator (Id);
6236 -- Equality: look for any non-limited type (result is Boolean)
6238 when Name_Op_Eq | Name_Op_Ne =>
6239 while Id /= Priv_Id loop
6241 and then not Is_Limited_Type (Id)
6242 and then Is_Base_Type (Id)
6244 Add_Implicit_Operator (Standard_Boolean, Id);
6251 -- Comparison operators: scalar type, or array of scalar
6253 when Name_Op_Lt | Name_Op_Le | Name_Op_Gt | Name_Op_Ge =>
6254 while Id /= Priv_Id loop
6255 if (Is_Scalar_Type (Id)
6256 or else (Is_Array_Type (Id)
6257 and then Is_Scalar_Type (Component_Type (Id))))
6258 and then Is_Base_Type (Id)
6260 Add_Implicit_Operator (Standard_Boolean, Id);
6267 -- Arithmetic operators: any numeric type
6277 while Id /= Priv_Id loop
6278 if Is_Numeric_Type (Id) and then Is_Base_Type (Id) then
6279 Add_Implicit_Operator (Id);
6286 -- Concatenation: any one-dimensional array type
6288 when Name_Op_Concat =>
6289 while Id /= Priv_Id loop
6290 if Is_Array_Type (Id)
6291 and then Number_Dimensions (Id) = 1
6292 and then Is_Base_Type (Id)
6294 Add_Implicit_Operator (Id);
6301 -- What is the others condition here? Should we be using a
6302 -- subtype of Name_Id that would restrict to operators ???
6304 when others => null;
6307 -- If we fall through, then we do not have an implicit operator
6311 end Has_Implicit_Operator;
6313 -----------------------------------
6314 -- Has_Loop_In_Inner_Open_Scopes --
6315 -----------------------------------
6317 function Has_Loop_In_Inner_Open_Scopes (S : Entity_Id) return Boolean is
6319 -- Several scope stacks are maintained by Scope_Stack. The base of the
6320 -- currently active scope stack is denoted by the Is_Active_Stack_Base
6321 -- flag in the scope stack entry. Note that the scope stacks used to
6322 -- simply be delimited implicitly by the presence of Standard_Standard
6323 -- at their base, but there now are cases where this is not sufficient
6324 -- because Standard_Standard actually may appear in the middle of the
6325 -- active set of scopes.
6327 for J in reverse 0 .. Scope_Stack.Last loop
6329 -- S was reached without seing a loop scope first
6331 if Scope_Stack.Table (J).Entity = S then
6334 -- S was not yet reached, so it contains at least one inner loop
6336 elsif Ekind (Scope_Stack.Table (J).Entity) = E_Loop then
6340 -- Check Is_Active_Stack_Base to tell us when to stop, as there are
6341 -- cases where Standard_Standard appears in the middle of the active
6342 -- set of scopes. This affects the declaration and overriding of
6343 -- private inherited operations in instantiations of generic child
6346 pragma Assert (not Scope_Stack.Table (J).Is_Active_Stack_Base);
6349 raise Program_Error; -- unreachable
6350 end Has_Loop_In_Inner_Open_Scopes;
6352 --------------------
6353 -- In_Open_Scopes --
6354 --------------------
6356 function In_Open_Scopes (S : Entity_Id) return Boolean is
6358 -- Several scope stacks are maintained by Scope_Stack. The base of the
6359 -- currently active scope stack is denoted by the Is_Active_Stack_Base
6360 -- flag in the scope stack entry. Note that the scope stacks used to
6361 -- simply be delimited implicitly by the presence of Standard_Standard
6362 -- at their base, but there now are cases where this is not sufficient
6363 -- because Standard_Standard actually may appear in the middle of the
6364 -- active set of scopes.
6366 for J in reverse 0 .. Scope_Stack.Last loop
6367 if Scope_Stack.Table (J).Entity = S then
6371 -- Check Is_Active_Stack_Base to tell us when to stop, as there are
6372 -- cases where Standard_Standard appears in the middle of the active
6373 -- set of scopes. This affects the declaration and overriding of
6374 -- private inherited operations in instantiations of generic child
6377 exit when Scope_Stack.Table (J).Is_Active_Stack_Base;
6383 -----------------------------
6384 -- Inherit_Renamed_Profile --
6385 -----------------------------
6387 procedure Inherit_Renamed_Profile (New_S : Entity_Id; Old_S : Entity_Id) is
6394 if Ekind (Old_S) = E_Operator then
6395 New_F := First_Formal (New_S);
6397 while Present (New_F) loop
6398 Set_Etype (New_F, Base_Type (Etype (New_F)));
6399 Next_Formal (New_F);
6402 Set_Etype (New_S, Base_Type (Etype (New_S)));
6405 New_F := First_Formal (New_S);
6406 Old_F := First_Formal (Old_S);
6408 while Present (New_F) loop
6409 New_T := Etype (New_F);
6410 Old_T := Etype (Old_F);
6412 -- If the new type is a renaming of the old one, as is the
6413 -- case for actuals in instances, retain its name, to simplify
6414 -- later disambiguation.
6416 if Nkind (Parent (New_T)) = N_Subtype_Declaration
6417 and then Is_Entity_Name (Subtype_Indication (Parent (New_T)))
6418 and then Entity (Subtype_Indication (Parent (New_T))) = Old_T
6422 Set_Etype (New_F, Old_T);
6425 Next_Formal (New_F);
6426 Next_Formal (Old_F);
6429 if Ekind_In (Old_S, E_Function, E_Enumeration_Literal) then
6430 Set_Etype (New_S, Etype (Old_S));
6433 end Inherit_Renamed_Profile;
6439 procedure Initialize is
6444 -------------------------
6445 -- Install_Use_Clauses --
6446 -------------------------
6448 procedure Install_Use_Clauses
6450 Force_Installation : Boolean := False)
6458 while Present (U) loop
6460 -- Case of USE package
6462 if Nkind (U) = N_Use_Package_Clause then
6463 P := First (Names (U));
6464 while Present (P) loop
6467 if Ekind (Id) = E_Package then
6469 Note_Redundant_Use (P);
6471 elsif Present (Renamed_Object (Id))
6472 and then In_Use (Renamed_Object (Id))
6474 Note_Redundant_Use (P);
6476 elsif Force_Installation or else Applicable_Use (P) then
6477 Use_One_Package (Id, U);
6488 P := First (Subtype_Marks (U));
6489 while Present (P) loop
6490 if not Is_Entity_Name (P)
6491 or else No (Entity (P))
6495 elsif Entity (P) /= Any_Type then
6503 Next_Use_Clause (U);
6505 end Install_Use_Clauses;
6507 -------------------------------------
6508 -- Is_Appropriate_For_Entry_Prefix --
6509 -------------------------------------
6511 function Is_Appropriate_For_Entry_Prefix (T : Entity_Id) return Boolean is
6512 P_Type : Entity_Id := T;
6515 if Is_Access_Type (P_Type) then
6516 P_Type := Designated_Type (P_Type);
6519 return Is_Task_Type (P_Type) or else Is_Protected_Type (P_Type);
6520 end Is_Appropriate_For_Entry_Prefix;
6522 -------------------------------
6523 -- Is_Appropriate_For_Record --
6524 -------------------------------
6526 function Is_Appropriate_For_Record (T : Entity_Id) return Boolean is
6528 function Has_Components (T1 : Entity_Id) return Boolean;
6529 -- Determine if given type has components (i.e. is either a record
6530 -- type or a type that has discriminants).
6532 --------------------
6533 -- Has_Components --
6534 --------------------
6536 function Has_Components (T1 : Entity_Id) return Boolean is
6538 return Is_Record_Type (T1)
6539 or else (Is_Private_Type (T1) and then Has_Discriminants (T1))
6540 or else (Is_Task_Type (T1) and then Has_Discriminants (T1))
6541 or else (Is_Incomplete_Type (T1)
6542 and then From_With_Type (T1)
6543 and then Present (Non_Limited_View (T1))
6544 and then Is_Record_Type
6545 (Get_Full_View (Non_Limited_View (T1))));
6548 -- Start of processing for Is_Appropriate_For_Record
6553 and then (Has_Components (T)
6554 or else (Is_Access_Type (T)
6555 and then Has_Components (Designated_Type (T))));
6556 end Is_Appropriate_For_Record;
6558 ------------------------
6559 -- Note_Redundant_Use --
6560 ------------------------
6562 procedure Note_Redundant_Use (Clause : Node_Id) is
6563 Pack_Name : constant Entity_Id := Entity (Clause);
6564 Cur_Use : constant Node_Id := Current_Use_Clause (Pack_Name);
6565 Decl : constant Node_Id := Parent (Clause);
6567 Prev_Use : Node_Id := Empty;
6568 Redundant : Node_Id := Empty;
6569 -- The Use_Clause which is actually redundant. In the simplest case it
6570 -- is Pack itself, but when we compile a body we install its context
6571 -- before that of its spec, in which case it is the use_clause in the
6572 -- spec that will appear to be redundant, and we want the warning to be
6573 -- placed on the body. Similar complications appear when the redundancy
6574 -- is between a child unit and one of its ancestors.
6577 Set_Redundant_Use (Clause, True);
6579 if not Comes_From_Source (Clause)
6581 or else not Warn_On_Redundant_Constructs
6586 if not Is_Compilation_Unit (Current_Scope) then
6588 -- If the use_clause is in an inner scope, it is made redundant by
6589 -- some clause in the current context, with one exception: If we're
6590 -- compiling a nested package body, and the use_clause comes from the
6591 -- corresponding spec, the clause is not necessarily fully redundant,
6592 -- so we should not warn. If a warning was warranted, it would have
6593 -- been given when the spec was processed.
6595 if Nkind (Parent (Decl)) = N_Package_Specification then
6597 Package_Spec_Entity : constant Entity_Id :=
6598 Defining_Unit_Name (Parent (Decl));
6600 if In_Package_Body (Package_Spec_Entity) then
6606 Redundant := Clause;
6607 Prev_Use := Cur_Use;
6609 elsif Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Body then
6611 Cur_Unit : constant Unit_Number_Type := Get_Source_Unit (Cur_Use);
6612 New_Unit : constant Unit_Number_Type := Get_Source_Unit (Clause);
6616 if Cur_Unit = New_Unit then
6618 -- Redundant clause in same body
6620 Redundant := Clause;
6621 Prev_Use := Cur_Use;
6623 elsif Cur_Unit = Current_Sem_Unit then
6625 -- If the new clause is not in the current unit it has been
6626 -- analyzed first, and it makes the other one redundant.
6627 -- However, if the new clause appears in a subunit, Cur_Unit
6628 -- is still the parent, and in that case the redundant one
6629 -- is the one appearing in the subunit.
6631 if Nkind (Unit (Cunit (New_Unit))) = N_Subunit then
6632 Redundant := Clause;
6633 Prev_Use := Cur_Use;
6635 -- Most common case: redundant clause in body,
6636 -- original clause in spec. Current scope is spec entity.
6641 Unit (Library_Unit (Cunit (Current_Sem_Unit))))
6643 Redundant := Cur_Use;
6647 -- The new clause may appear in an unrelated unit, when
6648 -- the parents of a generic are being installed prior to
6649 -- instantiation. In this case there must be no warning.
6650 -- We detect this case by checking whether the current top
6651 -- of the stack is related to the current compilation.
6653 Scop := Current_Scope;
6654 while Present (Scop)
6655 and then Scop /= Standard_Standard
6657 if Is_Compilation_Unit (Scop)
6658 and then not Is_Child_Unit (Scop)
6662 elsif Scop = Cunit_Entity (Current_Sem_Unit) then
6666 Scop := Scope (Scop);
6669 Redundant := Cur_Use;
6673 elsif New_Unit = Current_Sem_Unit then
6674 Redundant := Clause;
6675 Prev_Use := Cur_Use;
6678 -- Neither is the current unit, so they appear in parent or
6679 -- sibling units. Warning will be emitted elsewhere.
6685 elsif Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Declaration
6686 and then Present (Parent_Spec (Unit (Cunit (Current_Sem_Unit))))
6688 -- Use_clause is in child unit of current unit, and the child unit
6689 -- appears in the context of the body of the parent, so it has been
6690 -- installed first, even though it is the redundant one. Depending on
6691 -- their placement in the context, the visible or the private parts
6692 -- of the two units, either might appear as redundant, but the
6693 -- message has to be on the current unit.
6695 if Get_Source_Unit (Cur_Use) = Current_Sem_Unit then
6696 Redundant := Cur_Use;
6699 Redundant := Clause;
6700 Prev_Use := Cur_Use;
6703 -- If the new use clause appears in the private part of a parent unit
6704 -- it may appear to be redundant w.r.t. a use clause in a child unit,
6705 -- but the previous use clause was needed in the visible part of the
6706 -- child, and no warning should be emitted.
6708 if Nkind (Parent (Decl)) = N_Package_Specification
6710 List_Containing (Decl) = Private_Declarations (Parent (Decl))
6713 Par : constant Entity_Id := Defining_Entity (Parent (Decl));
6714 Spec : constant Node_Id :=
6715 Specification (Unit (Cunit (Current_Sem_Unit)));
6718 if Is_Compilation_Unit (Par)
6719 and then Par /= Cunit_Entity (Current_Sem_Unit)
6720 and then Parent (Cur_Use) = Spec
6722 List_Containing (Cur_Use) = Visible_Declarations (Spec)
6729 -- Finally, if the current use clause is in the context then
6730 -- the clause is redundant when it is nested within the unit.
6732 elsif Nkind (Parent (Cur_Use)) = N_Compilation_Unit
6733 and then Nkind (Parent (Parent (Clause))) /= N_Compilation_Unit
6734 and then Get_Source_Unit (Cur_Use) = Get_Source_Unit (Clause)
6736 Redundant := Clause;
6737 Prev_Use := Cur_Use;
6743 if Present (Redundant) then
6744 Error_Msg_Sloc := Sloc (Prev_Use);
6745 Error_Msg_NE -- CODEFIX
6746 ("& is already use-visible through previous use clause #?",
6747 Redundant, Pack_Name);
6749 end Note_Redundant_Use;
6755 procedure Pop_Scope is
6756 SST : Scope_Stack_Entry renames Scope_Stack.Table (Scope_Stack.Last);
6757 S : constant Entity_Id := SST.Entity;
6760 if Debug_Flag_E then
6764 -- Set Default_Storage_Pool field of the library unit if necessary
6766 if Ekind_In (S, E_Package, E_Generic_Package)
6768 Nkind (Parent (Unit_Declaration_Node (S))) = N_Compilation_Unit
6771 Aux : constant Node_Id :=
6772 Aux_Decls_Node (Parent (Unit_Declaration_Node (S)));
6774 if No (Default_Storage_Pool (Aux)) then
6775 Set_Default_Storage_Pool (Aux, Default_Pool);
6780 Scope_Suppress := SST.Save_Scope_Suppress;
6781 Local_Suppress_Stack_Top := SST.Save_Local_Suppress_Stack_Top;
6782 Check_Policy_List := SST.Save_Check_Policy_List;
6783 Default_Pool := SST.Save_Default_Storage_Pool;
6785 if Debug_Flag_W then
6786 Write_Str ("<-- exiting scope: ");
6787 Write_Name (Chars (Current_Scope));
6788 Write_Str (", Depth=");
6789 Write_Int (Int (Scope_Stack.Last));
6793 End_Use_Clauses (SST.First_Use_Clause);
6795 -- If the actions to be wrapped are still there they will get lost
6796 -- causing incomplete code to be generated. It is better to abort in
6797 -- this case (and we do the abort even with assertions off since the
6798 -- penalty is incorrect code generation)
6800 if SST.Actions_To_Be_Wrapped_Before /= No_List
6802 SST.Actions_To_Be_Wrapped_After /= No_List
6804 raise Program_Error;
6807 -- Free last subprogram name if allocated, and pop scope
6809 Free (SST.Last_Subprogram_Name);
6810 Scope_Stack.Decrement_Last;
6817 procedure Push_Scope (S : Entity_Id) is
6818 E : constant Entity_Id := Scope (S);
6821 if Ekind (S) = E_Void then
6824 -- Set scope depth if not a non-concurrent type, and we have not yet set
6825 -- the scope depth. This means that we have the first occurrence of the
6826 -- scope, and this is where the depth is set.
6828 elsif (not Is_Type (S) or else Is_Concurrent_Type (S))
6829 and then not Scope_Depth_Set (S)
6831 if S = Standard_Standard then
6832 Set_Scope_Depth_Value (S, Uint_0);
6834 elsif Is_Child_Unit (S) then
6835 Set_Scope_Depth_Value (S, Uint_1);
6837 elsif not Is_Record_Type (Current_Scope) then
6838 if Ekind (S) = E_Loop then
6839 Set_Scope_Depth_Value (S, Scope_Depth (Current_Scope));
6841 Set_Scope_Depth_Value (S, Scope_Depth (Current_Scope) + 1);
6846 Scope_Stack.Increment_Last;
6849 SST : Scope_Stack_Entry renames Scope_Stack.Table (Scope_Stack.Last);
6853 SST.Save_Scope_Suppress := Scope_Suppress;
6854 SST.Save_Local_Suppress_Stack_Top := Local_Suppress_Stack_Top;
6855 SST.Save_Check_Policy_List := Check_Policy_List;
6856 SST.Save_Default_Storage_Pool := Default_Pool;
6858 if Scope_Stack.Last > Scope_Stack.First then
6859 SST.Component_Alignment_Default := Scope_Stack.Table
6860 (Scope_Stack.Last - 1).
6861 Component_Alignment_Default;
6864 SST.Last_Subprogram_Name := null;
6865 SST.Is_Transient := False;
6866 SST.Node_To_Be_Wrapped := Empty;
6867 SST.Pending_Freeze_Actions := No_List;
6868 SST.Actions_To_Be_Wrapped_Before := No_List;
6869 SST.Actions_To_Be_Wrapped_After := No_List;
6870 SST.First_Use_Clause := Empty;
6871 SST.Is_Active_Stack_Base := False;
6872 SST.Previous_Visibility := False;
6875 if Debug_Flag_W then
6876 Write_Str ("--> new scope: ");
6877 Write_Name (Chars (Current_Scope));
6878 Write_Str (", Id=");
6879 Write_Int (Int (Current_Scope));
6880 Write_Str (", Depth=");
6881 Write_Int (Int (Scope_Stack.Last));
6885 -- Deal with copying flags from the previous scope to this one. This is
6886 -- not necessary if either scope is standard, or if the new scope is a
6889 if S /= Standard_Standard
6890 and then Scope (S) /= Standard_Standard
6891 and then not Is_Child_Unit (S)
6893 if Nkind (E) not in N_Entity then
6897 -- Copy categorization flags from Scope (S) to S, this is not done
6898 -- when Scope (S) is Standard_Standard since propagation is from
6899 -- library unit entity inwards. Copy other relevant attributes as
6900 -- well (Discard_Names in particular).
6902 -- We only propagate inwards for library level entities,
6903 -- inner level subprograms do not inherit the categorization.
6905 if Is_Library_Level_Entity (S) then
6906 Set_Is_Preelaborated (S, Is_Preelaborated (E));
6907 Set_Is_Shared_Passive (S, Is_Shared_Passive (E));
6908 Set_Discard_Names (S, Discard_Names (E));
6909 Set_Suppress_Value_Tracking_On_Call
6910 (S, Suppress_Value_Tracking_On_Call (E));
6911 Set_Categorization_From_Scope (E => S, Scop => E);
6915 if Is_Child_Unit (S)
6916 and then Present (E)
6917 and then Ekind_In (E, E_Package, E_Generic_Package)
6919 Nkind (Parent (Unit_Declaration_Node (E))) = N_Compilation_Unit
6922 Aux : constant Node_Id :=
6923 Aux_Decls_Node (Parent (Unit_Declaration_Node (E)));
6925 if Present (Default_Storage_Pool (Aux)) then
6926 Default_Pool := Default_Storage_Pool (Aux);
6932 ---------------------
6933 -- Premature_Usage --
6934 ---------------------
6936 procedure Premature_Usage (N : Node_Id) is
6937 Kind : constant Node_Kind := Nkind (Parent (Entity (N)));
6938 E : Entity_Id := Entity (N);
6941 -- Within an instance, the analysis of the actual for a formal object
6942 -- does not see the name of the object itself. This is significant only
6943 -- if the object is an aggregate, where its analysis does not do any
6944 -- name resolution on component associations. (see 4717-008). In such a
6945 -- case, look for the visible homonym on the chain.
6948 and then Present (Homonym (E))
6953 and then not In_Open_Scopes (Scope (E))
6960 Set_Etype (N, Etype (E));
6965 if Kind = N_Component_Declaration then
6967 ("component&! cannot be used before end of record declaration", N);
6969 elsif Kind = N_Parameter_Specification then
6971 ("formal parameter&! cannot be used before end of specification",
6974 elsif Kind = N_Discriminant_Specification then
6976 ("discriminant&! cannot be used before end of discriminant part",
6979 elsif Kind = N_Procedure_Specification
6980 or else Kind = N_Function_Specification
6983 ("subprogram&! cannot be used before end of its declaration",
6986 elsif Kind = N_Full_Type_Declaration then
6988 ("type& cannot be used before end of its declaration!", N);
6992 ("object& cannot be used before end of its declaration!", N);
6994 end Premature_Usage;
6996 ------------------------
6997 -- Present_System_Aux --
6998 ------------------------
7000 function Present_System_Aux (N : Node_Id := Empty) return Boolean is
7002 Aux_Name : Unit_Name_Type;
7003 Unum : Unit_Number_Type;
7008 function Find_System (C_Unit : Node_Id) return Entity_Id;
7009 -- Scan context clause of compilation unit to find with_clause
7016 function Find_System (C_Unit : Node_Id) return Entity_Id is
7017 With_Clause : Node_Id;
7020 With_Clause := First (Context_Items (C_Unit));
7021 while Present (With_Clause) loop
7022 if (Nkind (With_Clause) = N_With_Clause
7023 and then Chars (Name (With_Clause)) = Name_System)
7024 and then Comes_From_Source (With_Clause)
7035 -- Start of processing for Present_System_Aux
7038 -- The child unit may have been loaded and analyzed already
7040 if Present (System_Aux_Id) then
7043 -- If no previous pragma for System.Aux, nothing to load
7045 elsif No (System_Extend_Unit) then
7048 -- Use the unit name given in the pragma to retrieve the unit.
7049 -- Verify that System itself appears in the context clause of the
7050 -- current compilation. If System is not present, an error will
7051 -- have been reported already.
7054 With_Sys := Find_System (Cunit (Current_Sem_Unit));
7056 The_Unit := Unit (Cunit (Current_Sem_Unit));
7060 (Nkind (The_Unit) = N_Package_Body
7061 or else (Nkind (The_Unit) = N_Subprogram_Body
7063 not Acts_As_Spec (Cunit (Current_Sem_Unit))))
7065 With_Sys := Find_System (Library_Unit (Cunit (Current_Sem_Unit)));
7069 and then Present (N)
7071 -- If we are compiling a subunit, we need to examine its
7072 -- context as well (Current_Sem_Unit is the parent unit);
7074 The_Unit := Parent (N);
7075 while Nkind (The_Unit) /= N_Compilation_Unit loop
7076 The_Unit := Parent (The_Unit);
7079 if Nkind (Unit (The_Unit)) = N_Subunit then
7080 With_Sys := Find_System (The_Unit);
7084 if No (With_Sys) then
7088 Loc := Sloc (With_Sys);
7089 Get_Name_String (Chars (Expression (System_Extend_Unit)));
7090 Name_Buffer (8 .. Name_Len + 7) := Name_Buffer (1 .. Name_Len);
7091 Name_Buffer (1 .. 7) := "system.";
7092 Name_Buffer (Name_Len + 8) := '%';
7093 Name_Buffer (Name_Len + 9) := 's';
7094 Name_Len := Name_Len + 9;
7095 Aux_Name := Name_Find;
7099 (Load_Name => Aux_Name,
7102 Error_Node => With_Sys);
7104 if Unum /= No_Unit then
7105 Semantics (Cunit (Unum));
7107 Defining_Entity (Specification (Unit (Cunit (Unum))));
7110 Make_With_Clause (Loc,
7112 Make_Expanded_Name (Loc,
7113 Chars => Chars (System_Aux_Id),
7114 Prefix => New_Reference_To (Scope (System_Aux_Id), Loc),
7115 Selector_Name => New_Reference_To (System_Aux_Id, Loc)));
7117 Set_Entity (Name (Withn), System_Aux_Id);
7119 Set_Library_Unit (Withn, Cunit (Unum));
7120 Set_Corresponding_Spec (Withn, System_Aux_Id);
7121 Set_First_Name (Withn, True);
7122 Set_Implicit_With (Withn, True);
7124 Insert_After (With_Sys, Withn);
7125 Mark_Rewrite_Insertion (Withn);
7126 Set_Context_Installed (Withn);
7130 -- Here if unit load failed
7133 Error_Msg_Name_1 := Name_System;
7134 Error_Msg_Name_2 := Chars (Expression (System_Extend_Unit));
7136 ("extension package `%.%` does not exist",
7137 Opt.System_Extend_Unit);
7141 end Present_System_Aux;
7143 -------------------------
7144 -- Restore_Scope_Stack --
7145 -------------------------
7147 procedure Restore_Scope_Stack (Handle_Use : Boolean := True) is
7150 Comp_Unit : Node_Id;
7151 In_Child : Boolean := False;
7152 Full_Vis : Boolean := True;
7153 SS_Last : constant Int := Scope_Stack.Last;
7156 -- Restore visibility of previous scope stack, if any
7158 for J in reverse 0 .. Scope_Stack.Last loop
7159 exit when Scope_Stack.Table (J).Entity = Standard_Standard
7160 or else No (Scope_Stack.Table (J).Entity);
7162 S := Scope_Stack.Table (J).Entity;
7164 if not Is_Hidden_Open_Scope (S) then
7166 -- If the parent scope is hidden, its entities are hidden as
7167 -- well, unless the entity is the instantiation currently
7170 if not Is_Hidden_Open_Scope (Scope (S))
7171 or else not Analyzed (Parent (S))
7172 or else Scope (S) = Standard_Standard
7174 Set_Is_Immediately_Visible (S, True);
7177 E := First_Entity (S);
7178 while Present (E) loop
7179 if Is_Child_Unit (E) then
7180 if not From_With_Type (E) then
7181 Set_Is_Immediately_Visible (E,
7182 Is_Visible_Child_Unit (E) or else In_Open_Scopes (E));
7186 (Nkind (Parent (E)) = N_Defining_Program_Unit_Name
7188 Nkind (Parent (Parent (E))) = N_Package_Specification);
7189 Set_Is_Immediately_Visible (E,
7190 Limited_View_Installed (Parent (Parent (E))));
7193 Set_Is_Immediately_Visible (E, True);
7199 and then Is_Package_Or_Generic_Package (S)
7201 -- We are in the visible part of the package scope
7203 exit when E = First_Private_Entity (S);
7207 -- The visibility of child units (siblings of current compilation)
7208 -- must be restored in any case. Their declarations may appear
7209 -- after the private part of the parent.
7211 if not Full_Vis then
7212 while Present (E) loop
7213 if Is_Child_Unit (E) then
7214 Set_Is_Immediately_Visible (E,
7215 Is_Visible_Child_Unit (E) or else In_Open_Scopes (E));
7223 if Is_Child_Unit (S)
7224 and not In_Child -- check only for current unit
7228 -- Restore visibility of parents according to whether the child
7229 -- is private and whether we are in its visible part.
7231 Comp_Unit := Parent (Unit_Declaration_Node (S));
7233 if Nkind (Comp_Unit) = N_Compilation_Unit
7234 and then Private_Present (Comp_Unit)
7238 elsif Is_Package_Or_Generic_Package (S)
7239 and then (In_Private_Part (S) or else In_Package_Body (S))
7243 -- if S is the scope of some instance (which has already been
7244 -- seen on the stack) it does not affect the visibility of
7247 elsif Is_Hidden_Open_Scope (S) then
7250 elsif (Ekind (S) = E_Procedure
7251 or else Ekind (S) = E_Function)
7252 and then Has_Completion (S)
7263 if SS_Last >= Scope_Stack.First
7264 and then Scope_Stack.Table (SS_Last).Entity /= Standard_Standard
7267 Install_Use_Clauses (Scope_Stack.Table (SS_Last).First_Use_Clause);
7269 end Restore_Scope_Stack;
7271 ----------------------
7272 -- Save_Scope_Stack --
7273 ----------------------
7275 procedure Save_Scope_Stack (Handle_Use : Boolean := True) is
7278 SS_Last : constant Int := Scope_Stack.Last;
7281 if SS_Last >= Scope_Stack.First
7282 and then Scope_Stack.Table (SS_Last).Entity /= Standard_Standard
7285 End_Use_Clauses (Scope_Stack.Table (SS_Last).First_Use_Clause);
7288 -- If the call is from within a compilation unit, as when called from
7289 -- Rtsfind, make current entries in scope stack invisible while we
7290 -- analyze the new unit.
7292 for J in reverse 0 .. SS_Last loop
7293 exit when Scope_Stack.Table (J).Entity = Standard_Standard
7294 or else No (Scope_Stack.Table (J).Entity);
7296 S := Scope_Stack.Table (J).Entity;
7297 Set_Is_Immediately_Visible (S, False);
7299 E := First_Entity (S);
7300 while Present (E) loop
7301 Set_Is_Immediately_Visible (E, False);
7307 end Save_Scope_Stack;
7313 procedure Set_Use (L : List_Id) is
7315 Pack_Name : Node_Id;
7322 while Present (Decl) loop
7323 if Nkind (Decl) = N_Use_Package_Clause then
7324 Chain_Use_Clause (Decl);
7326 Pack_Name := First (Names (Decl));
7327 while Present (Pack_Name) loop
7328 Pack := Entity (Pack_Name);
7330 if Ekind (Pack) = E_Package
7331 and then Applicable_Use (Pack_Name)
7333 Use_One_Package (Pack, Decl);
7339 elsif Nkind (Decl) = N_Use_Type_Clause then
7340 Chain_Use_Clause (Decl);
7342 Id := First (Subtype_Marks (Decl));
7343 while Present (Id) loop
7344 if Entity (Id) /= Any_Type then
7357 ---------------------
7358 -- Use_One_Package --
7359 ---------------------
7361 procedure Use_One_Package (P : Entity_Id; N : Node_Id) is
7364 Current_Instance : Entity_Id := Empty;
7366 Private_With_OK : Boolean := False;
7369 if Ekind (P) /= E_Package then
7374 Set_Current_Use_Clause (P, N);
7376 -- Ada 2005 (AI-50217): Check restriction
7378 if From_With_Type (P) then
7379 Error_Msg_N ("limited withed package cannot appear in use clause", N);
7382 -- Find enclosing instance, if any
7385 Current_Instance := Current_Scope;
7386 while not Is_Generic_Instance (Current_Instance) loop
7387 Current_Instance := Scope (Current_Instance);
7390 if No (Hidden_By_Use_Clause (N)) then
7391 Set_Hidden_By_Use_Clause (N, New_Elmt_List);
7395 -- If unit is a package renaming, indicate that the renamed
7396 -- package is also in use (the flags on both entities must
7397 -- remain consistent, and a subsequent use of either of them
7398 -- should be recognized as redundant).
7400 if Present (Renamed_Object (P)) then
7401 Set_In_Use (Renamed_Object (P));
7402 Set_Current_Use_Clause (Renamed_Object (P), N);
7403 Real_P := Renamed_Object (P);
7408 -- Ada 2005 (AI-262): Check the use_clause of a private withed package
7409 -- found in the private part of a package specification
7411 if In_Private_Part (Current_Scope)
7412 and then Has_Private_With (P)
7413 and then Is_Child_Unit (Current_Scope)
7414 and then Is_Child_Unit (P)
7415 and then Is_Ancestor_Package (Scope (Current_Scope), P)
7417 Private_With_OK := True;
7420 -- Loop through entities in one package making them potentially
7423 Id := First_Entity (P);
7425 and then (Id /= First_Private_Entity (P)
7426 or else Private_With_OK) -- Ada 2005 (AI-262)
7428 Prev := Current_Entity (Id);
7429 while Present (Prev) loop
7430 if Is_Immediately_Visible (Prev)
7431 and then (not Is_Overloadable (Prev)
7432 or else not Is_Overloadable (Id)
7433 or else (Type_Conformant (Id, Prev)))
7435 if No (Current_Instance) then
7437 -- Potentially use-visible entity remains hidden
7439 goto Next_Usable_Entity;
7441 -- A use clause within an instance hides outer global entities,
7442 -- which are not used to resolve local entities in the
7443 -- instance. Note that the predefined entities in Standard
7444 -- could not have been hidden in the generic by a use clause,
7445 -- and therefore remain visible. Other compilation units whose
7446 -- entities appear in Standard must be hidden in an instance.
7448 -- To determine whether an entity is external to the instance
7449 -- we compare the scope depth of its scope with that of the
7450 -- current instance. However, a generic actual of a subprogram
7451 -- instance is declared in the wrapper package but will not be
7452 -- hidden by a use-visible entity. similarly, an entity that is
7453 -- declared in an enclosing instance will not be hidden by an
7454 -- an entity declared in a generic actual, which can only have
7455 -- been use-visible in the generic and will not have hidden the
7456 -- entity in the generic parent.
7458 -- If Id is called Standard, the predefined package with the
7459 -- same name is in the homonym chain. It has to be ignored
7460 -- because it has no defined scope (being the only entity in
7461 -- the system with this mandated behavior).
7463 elsif not Is_Hidden (Id)
7464 and then Present (Scope (Prev))
7465 and then not Is_Wrapper_Package (Scope (Prev))
7466 and then Scope_Depth (Scope (Prev)) <
7467 Scope_Depth (Current_Instance)
7468 and then (Scope (Prev) /= Standard_Standard
7469 or else Sloc (Prev) > Standard_Location)
7471 if In_Open_Scopes (Scope (Prev))
7472 and then Is_Generic_Instance (Scope (Prev))
7473 and then Present (Associated_Formal_Package (P))
7478 Set_Is_Potentially_Use_Visible (Id);
7479 Set_Is_Immediately_Visible (Prev, False);
7480 Append_Elmt (Prev, Hidden_By_Use_Clause (N));
7484 -- A user-defined operator is not use-visible if the predefined
7485 -- operator for the type is immediately visible, which is the case
7486 -- if the type of the operand is in an open scope. This does not
7487 -- apply to user-defined operators that have operands of different
7488 -- types, because the predefined mixed mode operations (multiply
7489 -- and divide) apply to universal types and do not hide anything.
7491 elsif Ekind (Prev) = E_Operator
7492 and then Operator_Matches_Spec (Prev, Id)
7493 and then In_Open_Scopes
7494 (Scope (Base_Type (Etype (First_Formal (Id)))))
7495 and then (No (Next_Formal (First_Formal (Id)))
7496 or else Etype (First_Formal (Id))
7497 = Etype (Next_Formal (First_Formal (Id)))
7498 or else Chars (Prev) = Name_Op_Expon)
7500 goto Next_Usable_Entity;
7502 -- In an instance, two homonyms may become use_visible through the
7503 -- actuals of distinct formal packages. In the generic, only the
7504 -- current one would have been visible, so make the other one
7507 elsif Present (Current_Instance)
7508 and then Is_Potentially_Use_Visible (Prev)
7509 and then not Is_Overloadable (Prev)
7510 and then Scope (Id) /= Scope (Prev)
7511 and then Used_As_Generic_Actual (Scope (Prev))
7512 and then Used_As_Generic_Actual (Scope (Id))
7513 and then not In_Same_List (Current_Use_Clause (Scope (Prev)),
7514 Current_Use_Clause (Scope (Id)))
7516 Set_Is_Potentially_Use_Visible (Prev, False);
7517 Append_Elmt (Prev, Hidden_By_Use_Clause (N));
7520 Prev := Homonym (Prev);
7523 -- On exit, we know entity is not hidden, unless it is private
7525 if not Is_Hidden (Id)
7526 and then ((not Is_Child_Unit (Id))
7527 or else Is_Visible_Child_Unit (Id))
7529 Set_Is_Potentially_Use_Visible (Id);
7531 if Is_Private_Type (Id)
7532 and then Present (Full_View (Id))
7534 Set_Is_Potentially_Use_Visible (Full_View (Id));
7538 <<Next_Usable_Entity>>
7542 -- Child units are also made use-visible by a use clause, but they may
7543 -- appear after all visible declarations in the parent entity list.
7545 while Present (Id) loop
7546 if Is_Child_Unit (Id)
7547 and then Is_Visible_Child_Unit (Id)
7549 Set_Is_Potentially_Use_Visible (Id);
7555 if Chars (Real_P) = Name_System
7556 and then Scope (Real_P) = Standard_Standard
7557 and then Present_System_Aux (N)
7559 Use_One_Package (System_Aux_Id, N);
7562 end Use_One_Package;
7568 procedure Use_One_Type (Id : Node_Id) is
7570 Is_Known_Used : Boolean;
7574 function Spec_Reloaded_For_Body return Boolean;
7575 -- Determine whether the compilation unit is a package body and the use
7576 -- type clause is in the spec of the same package. Even though the spec
7577 -- was analyzed first, its context is reloaded when analysing the body.
7579 procedure Use_Class_Wide_Operations (Typ : Entity_Id);
7580 -- AI05-150: if the use_type_clause carries the "all" qualifier,
7581 -- class-wide operations of ancestor types are use-visible if the
7582 -- ancestor type is visible.
7584 ----------------------------
7585 -- Spec_Reloaded_For_Body --
7586 ----------------------------
7588 function Spec_Reloaded_For_Body return Boolean is
7590 if Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Body then
7592 Spec : constant Node_Id :=
7593 Parent (List_Containing (Parent (Id)));
7596 Nkind (Spec) = N_Package_Specification
7597 and then Corresponding_Body (Parent (Spec)) =
7598 Cunit_Entity (Current_Sem_Unit);
7603 end Spec_Reloaded_For_Body;
7605 -------------------------------
7606 -- Use_Class_Wide_Operations --
7607 -------------------------------
7609 procedure Use_Class_Wide_Operations (Typ : Entity_Id) is
7613 function Is_Class_Wide_Operation_Of
7615 T : Entity_Id) return Boolean;
7616 -- Determine whether a subprogram has a class-wide parameter or
7617 -- result that is T'Class.
7619 ---------------------------------
7620 -- Is_Class_Wide_Operation_Of --
7621 ---------------------------------
7623 function Is_Class_Wide_Operation_Of
7625 T : Entity_Id) return Boolean
7630 Formal := First_Formal (Op);
7631 while Present (Formal) loop
7632 if Etype (Formal) = Class_Wide_Type (T) then
7635 Next_Formal (Formal);
7638 if Etype (Op) = Class_Wide_Type (T) then
7643 end Is_Class_Wide_Operation_Of;
7645 -- Start of processing for Use_Class_Wide_Operations
7648 Scop := Scope (Typ);
7649 if not Is_Hidden (Scop) then
7650 Ent := First_Entity (Scop);
7651 while Present (Ent) loop
7652 if Is_Overloadable (Ent)
7653 and then Is_Class_Wide_Operation_Of (Ent, Typ)
7654 and then not Is_Potentially_Use_Visible (Ent)
7656 Set_Is_Potentially_Use_Visible (Ent);
7657 Append_Elmt (Ent, Used_Operations (Parent (Id)));
7664 if Is_Derived_Type (Typ) then
7665 Use_Class_Wide_Operations (Etype (Base_Type (Typ)));
7667 end Use_Class_Wide_Operations;
7669 -- Start of processing for Use_One_Type;
7672 -- It is the type determined by the subtype mark (8.4(8)) whose
7673 -- operations become potentially use-visible.
7675 T := Base_Type (Entity (Id));
7677 -- Either the type itself is used, the package where it is declared
7678 -- is in use or the entity is declared in the current package, thus
7683 or else In_Use (Scope (T))
7684 or else Scope (T) = Current_Scope;
7686 Set_Redundant_Use (Id,
7687 Is_Known_Used or else Is_Potentially_Use_Visible (T));
7689 if Ekind (T) = E_Incomplete_Type then
7690 Error_Msg_N ("premature usage of incomplete type", Id);
7692 elsif In_Open_Scopes (Scope (T)) then
7695 -- A limited view cannot appear in a use_type clause. However, an access
7696 -- type whose designated type is limited has the flag but is not itself
7697 -- a limited view unless we only have a limited view of its enclosing
7700 elsif From_With_Type (T)
7701 and then From_With_Type (Scope (T))
7704 ("incomplete type from limited view "
7705 & "cannot appear in use clause", Id);
7707 -- If the subtype mark designates a subtype in a different package,
7708 -- we have to check that the parent type is visible, otherwise the
7709 -- use type clause is a noop. Not clear how to do that???
7711 elsif not Redundant_Use (Id) then
7714 -- If T is tagged, primitive operators on class-wide operands
7715 -- are also available.
7717 if Is_Tagged_Type (T) then
7718 Set_In_Use (Class_Wide_Type (T));
7721 Set_Current_Use_Clause (T, Parent (Id));
7722 Op_List := Collect_Primitive_Operations (T);
7724 -- Iterate over primitive operations of the type. If an operation is
7725 -- already use_visible, it is the result of a previous use_clause,
7726 -- and already appears on the corresponding entity chain.
7728 Elmt := First_Elmt (Op_List);
7729 while Present (Elmt) loop
7730 if (Nkind (Node (Elmt)) = N_Defining_Operator_Symbol
7731 or else Chars (Node (Elmt)) in Any_Operator_Name)
7732 and then not Is_Hidden (Node (Elmt))
7733 and then not Is_Potentially_Use_Visible (Node (Elmt))
7735 Set_Is_Potentially_Use_Visible (Node (Elmt));
7736 Append_Elmt (Node (Elmt), Used_Operations (Parent (Id)));
7738 elsif Ada_Version >= Ada_2012
7739 and then All_Present (Parent (Id))
7740 and then not Is_Hidden (Node (Elmt))
7741 and then not Is_Potentially_Use_Visible (Node (Elmt))
7743 Set_Is_Potentially_Use_Visible (Node (Elmt));
7744 Append_Elmt (Node (Elmt), Used_Operations (Parent (Id)));
7751 if Ada_Version >= Ada_2012
7752 and then All_Present (Parent (Id))
7753 and then Is_Tagged_Type (T)
7755 Use_Class_Wide_Operations (T);
7758 -- If warning on redundant constructs, check for unnecessary WITH
7760 if Warn_On_Redundant_Constructs
7761 and then Is_Known_Used
7763 -- with P; with P; use P;
7764 -- package P is package X is package body X is
7765 -- type T ... use P.T;
7767 -- The compilation unit is the body of X. GNAT first compiles the
7768 -- spec of X, then proceeds to the body. At that point P is marked
7769 -- as use visible. The analysis then reinstalls the spec along with
7770 -- its context. The use clause P.T is now recognized as redundant,
7771 -- but in the wrong context. Do not emit a warning in such cases.
7772 -- Do not emit a warning either if we are in an instance, there is
7773 -- no redundancy between an outer use_clause and one that appears
7774 -- within the generic.
7776 and then not Spec_Reloaded_For_Body
7777 and then not In_Instance
7779 -- The type already has a use clause
7783 -- Case where we know the current use clause for the type
7785 if Present (Current_Use_Clause (T)) then
7786 Use_Clause_Known : declare
7787 Clause1 : constant Node_Id := Parent (Id);
7788 Clause2 : constant Node_Id := Current_Use_Clause (T);
7795 function Entity_Of_Unit (U : Node_Id) return Entity_Id;
7796 -- Return the appropriate entity for determining which unit
7797 -- has a deeper scope: the defining entity for U, unless U
7798 -- is a package instance, in which case we retrieve the
7799 -- entity of the instance spec.
7801 --------------------
7802 -- Entity_Of_Unit --
7803 --------------------
7805 function Entity_Of_Unit (U : Node_Id) return Entity_Id is
7807 if Nkind (U) = N_Package_Instantiation
7808 and then Analyzed (U)
7810 return Defining_Entity (Instance_Spec (U));
7812 return Defining_Entity (U);
7816 -- Start of processing for Use_Clause_Known
7819 -- If both current use type clause and the use type clause
7820 -- for the type are at the compilation unit level, one of
7821 -- the units must be an ancestor of the other, and the
7822 -- warning belongs on the descendant.
7824 if Nkind (Parent (Clause1)) = N_Compilation_Unit
7826 Nkind (Parent (Clause2)) = N_Compilation_Unit
7829 -- If the unit is a subprogram body that acts as spec,
7830 -- the context clause is shared with the constructed
7831 -- subprogram spec. Clearly there is no redundancy.
7833 if Clause1 = Clause2 then
7837 Unit1 := Unit (Parent (Clause1));
7838 Unit2 := Unit (Parent (Clause2));
7840 -- If both clauses are on same unit, or one is the body
7841 -- of the other, or one of them is in a subunit, report
7842 -- redundancy on the later one.
7844 if Unit1 = Unit2 then
7845 Error_Msg_Sloc := Sloc (Current_Use_Clause (T));
7846 Error_Msg_NE -- CODEFIX
7847 ("& is already use-visible through previous "
7848 & "use_type_clause #?", Clause1, T);
7851 elsif Nkind (Unit1) = N_Subunit then
7852 Error_Msg_Sloc := Sloc (Current_Use_Clause (T));
7853 Error_Msg_NE -- CODEFIX
7854 ("& is already use-visible through previous "
7855 & "use_type_clause #?", Clause1, T);
7858 elsif Nkind_In (Unit2, N_Package_Body, N_Subprogram_Body)
7859 and then Nkind (Unit1) /= Nkind (Unit2)
7860 and then Nkind (Unit1) /= N_Subunit
7862 Error_Msg_Sloc := Sloc (Clause1);
7863 Error_Msg_NE -- CODEFIX
7864 ("& is already use-visible through previous "
7865 & "use_type_clause #?", Current_Use_Clause (T), T);
7869 -- There is a redundant use type clause in a child unit.
7870 -- Determine which of the units is more deeply nested.
7871 -- If a unit is a package instance, retrieve the entity
7872 -- and its scope from the instance spec.
7874 Ent1 := Entity_Of_Unit (Unit1);
7875 Ent2 := Entity_Of_Unit (Unit2);
7877 if Scope (Ent2) = Standard_Standard then
7878 Error_Msg_Sloc := Sloc (Current_Use_Clause (T));
7881 elsif Scope (Ent1) = Standard_Standard then
7882 Error_Msg_Sloc := Sloc (Id);
7885 -- If both units are child units, we determine which one
7886 -- is the descendant by the scope distance to the
7887 -- ultimate parent unit.
7897 and then Present (S2)
7898 and then S1 /= Standard_Standard
7899 and then S2 /= Standard_Standard
7905 if S1 = Standard_Standard then
7906 Error_Msg_Sloc := Sloc (Id);
7909 Error_Msg_Sloc := Sloc (Current_Use_Clause (T));
7915 Error_Msg_NE -- CODEFIX
7916 ("& is already use-visible through previous "
7917 & "use_type_clause #?", Err_No, Id);
7919 -- Case where current use type clause and the use type
7920 -- clause for the type are not both at the compilation unit
7921 -- level. In this case we don't have location information.
7924 Error_Msg_NE -- CODEFIX
7925 ("& is already use-visible through previous "
7926 & "use type clause?", Id, T);
7928 end Use_Clause_Known;
7930 -- Here if Current_Use_Clause is not set for T, another case
7931 -- where we do not have the location information available.
7934 Error_Msg_NE -- CODEFIX
7935 ("& is already use-visible through previous "
7936 & "use type clause?", Id, T);
7939 -- The package where T is declared is already used
7941 elsif In_Use (Scope (T)) then
7942 Error_Msg_Sloc := Sloc (Current_Use_Clause (Scope (T)));
7943 Error_Msg_NE -- CODEFIX
7944 ("& is already use-visible through package use clause #?",
7947 -- The current scope is the package where T is declared
7950 Error_Msg_Node_2 := Scope (T);
7951 Error_Msg_NE -- CODEFIX
7952 ("& is already use-visible inside package &?", Id, T);
7961 procedure Write_Info is
7962 Id : Entity_Id := First_Entity (Current_Scope);
7965 -- No point in dumping standard entities
7967 if Current_Scope = Standard_Standard then
7971 Write_Str ("========================================================");
7973 Write_Str (" Defined Entities in ");
7974 Write_Name (Chars (Current_Scope));
7976 Write_Str ("========================================================");
7980 Write_Str ("-- none --");
7984 while Present (Id) loop
7985 Write_Entity_Info (Id, " ");
7990 if Scope (Current_Scope) = Standard_Standard then
7992 -- Print information on the current unit itself
7994 Write_Entity_Info (Current_Scope, " ");
8007 for J in reverse 1 .. Scope_Stack.Last loop
8008 S := Scope_Stack.Table (J).Entity;
8009 Write_Int (Int (S));
8010 Write_Str (" === ");
8011 Write_Name (Chars (S));
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