1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2020, Free Software Foundation, Inc. --
11 -- GNAT is free software; you can redistribute it and/or modify it under --
12 -- terms of the GNU General Public License as published by the Free Soft- --
13 -- ware Foundation; either version 3, or (at your option) any later ver- --
14 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
15 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
16 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
17 -- for more details. You should have received a copy of the GNU General --
18 -- Public License distributed with GNAT; see file COPYING3. If not, go to --
19 -- http://www.gnu.org/licenses for a complete copy of the license. --
21 -- GNAT was originally developed by the GNAT team at New York University. --
22 -- Extensive contributions were provided by Ada Core Technologies Inc. --
24 ------------------------------------------------------------------------------
26 with Atree; use Atree;
27 with Debug; use Debug;
28 with Einfo; use Einfo;
29 with Elists; use Elists;
30 with Errout; use Errout;
31 with Exp_Disp; use Exp_Disp;
32 with Exp_Tss; use Exp_Tss;
33 with Exp_Util; use Exp_Util;
34 with Freeze; use Freeze;
35 with Ghost; use Ghost;
36 with Impunit; use Impunit;
38 with Lib.Load; use Lib.Load;
39 with Lib.Xref; use Lib.Xref;
40 with Namet; use Namet;
41 with Namet.Sp; use Namet.Sp;
42 with Nlists; use Nlists;
43 with Nmake; use Nmake;
45 with Output; use Output;
46 with Restrict; use Restrict;
47 with Rident; use Rident;
48 with Rtsfind; use Rtsfind;
50 with Sem_Aux; use Sem_Aux;
51 with Sem_Cat; use Sem_Cat;
52 with Sem_Ch3; use Sem_Ch3;
53 with Sem_Ch4; use Sem_Ch4;
54 with Sem_Ch6; use Sem_Ch6;
55 with Sem_Ch12; use Sem_Ch12;
56 with Sem_Ch13; use Sem_Ch13;
57 with Sem_Dim; use Sem_Dim;
58 with Sem_Disp; use Sem_Disp;
59 with Sem_Dist; use Sem_Dist;
60 with Sem_Elab; use Sem_Elab;
61 with Sem_Eval; use Sem_Eval;
62 with Sem_Prag; use Sem_Prag;
63 with Sem_Res; use Sem_Res;
64 with Sem_Util; use Sem_Util;
65 with Sem_Type; use Sem_Type;
66 with Stand; use Stand;
67 with Sinfo; use Sinfo;
68 with Sinfo.CN; use Sinfo.CN;
69 with Snames; use Snames;
72 with Tbuild; use Tbuild;
73 with Uintp; use Uintp;
75 package body Sem_Ch8 is
77 ------------------------------------
78 -- Visibility and Name Resolution --
79 ------------------------------------
81 -- This package handles name resolution and the collection of possible
82 -- interpretations for overloaded names, prior to overload resolution.
84 -- Name resolution is the process that establishes a mapping between source
85 -- identifiers and the entities they denote at each point in the program.
86 -- Each entity is represented by a defining occurrence. Each identifier
87 -- that denotes an entity points to the corresponding defining occurrence.
88 -- This is the entity of the applied occurrence. Each occurrence holds
89 -- an index into the names table, where source identifiers are stored.
91 -- Each entry in the names table for an identifier or designator uses the
92 -- Info pointer to hold a link to the currently visible entity that has
93 -- this name (see subprograms Get_Name_Entity_Id and Set_Name_Entity_Id
94 -- in package Sem_Util). The visibility is initialized at the beginning of
95 -- semantic processing to make entities in package Standard immediately
96 -- visible. The visibility table is used in a more subtle way when
97 -- compiling subunits (see below).
99 -- Entities that have the same name (i.e. homonyms) are chained. In the
100 -- case of overloaded entities, this chain holds all the possible meanings
101 -- of a given identifier. The process of overload resolution uses type
102 -- information to select from this chain the unique meaning of a given
105 -- Entities are also chained in their scope, through the Next_Entity link.
106 -- As a consequence, the name space is organized as a sparse matrix, where
107 -- each row corresponds to a scope, and each column to a source identifier.
108 -- Open scopes, that is to say scopes currently being compiled, have their
109 -- corresponding rows of entities in order, innermost scope first.
111 -- The scopes of packages that are mentioned in context clauses appear in
112 -- no particular order, interspersed among open scopes. This is because
113 -- in the course of analyzing the context of a compilation, a package
114 -- declaration is first an open scope, and subsequently an element of the
115 -- context. If subunits or child units are present, a parent unit may
116 -- appear under various guises at various times in the compilation.
118 -- When the compilation of the innermost scope is complete, the entities
119 -- defined therein are no longer visible. If the scope is not a package
120 -- declaration, these entities are never visible subsequently, and can be
121 -- removed from visibility chains. If the scope is a package declaration,
122 -- its visible declarations may still be accessible. Therefore the entities
123 -- defined in such a scope are left on the visibility chains, and only
124 -- their visibility (immediately visibility or potential use-visibility)
127 -- The ordering of homonyms on their chain does not necessarily follow
128 -- the order of their corresponding scopes on the scope stack. For
129 -- example, if package P and the enclosing scope both contain entities
130 -- named E, then when compiling the package body the chain for E will
131 -- hold the global entity first, and the local one (corresponding to
132 -- the current inner scope) next. As a result, name resolution routines
133 -- do not assume any relative ordering of the homonym chains, either
134 -- for scope nesting or to order of appearance of context clauses.
136 -- When compiling a child unit, entities in the parent scope are always
137 -- immediately visible. When compiling the body of a child unit, private
138 -- entities in the parent must also be made immediately visible. There
139 -- are separate routines to make the visible and private declarations
140 -- visible at various times (see package Sem_Ch7).
142 -- +--------+ +-----+
143 -- | In use |-------->| EU1 |-------------------------->
144 -- +--------+ +-----+
146 -- +--------+ +-----+ +-----+
147 -- | Stand. |---------------->| ES1 |--------------->| ES2 |--->
148 -- +--------+ +-----+ +-----+
150 -- +---------+ | +-----+
151 -- | with'ed |------------------------------>| EW2 |--->
152 -- +---------+ | +-----+
154 -- +--------+ +-----+ +-----+
155 -- | Scope2 |---------------->| E12 |--------------->| E22 |--->
156 -- +--------+ +-----+ +-----+
158 -- +--------+ +-----+ +-----+
159 -- | Scope1 |---------------->| E11 |--------------->| E12 |--->
160 -- +--------+ +-----+ +-----+
164 -- | | with'ed |----------------------------------------->
168 -- (innermost first) | |
169 -- +----------------------------+
170 -- Names table => | Id1 | | | | Id2 |
171 -- +----------------------------+
173 -- Name resolution must deal with several syntactic forms: simple names,
174 -- qualified names, indexed names, and various forms of calls.
176 -- Each identifier points to an entry in the names table. The resolution
177 -- of a simple name consists in traversing the homonym chain, starting
178 -- from the names table. If an entry is immediately visible, it is the one
179 -- designated by the identifier. If only potentially use-visible entities
180 -- are on the chain, we must verify that they do not hide each other. If
181 -- the entity we find is overloadable, we collect all other overloadable
182 -- entities on the chain as long as they are not hidden.
184 -- To resolve expanded names, we must find the entity at the intersection
185 -- of the entity chain for the scope (the prefix) and the homonym chain
186 -- for the selector. In general, homonym chains will be much shorter than
187 -- entity chains, so it is preferable to start from the names table as
188 -- well. If the entity found is overloadable, we must collect all other
189 -- interpretations that are defined in the scope denoted by the prefix.
191 -- For records, protected types, and tasks, their local entities are
192 -- removed from visibility chains on exit from the corresponding scope.
193 -- From the outside, these entities are always accessed by selected
194 -- notation, and the entity chain for the record type, protected type,
195 -- etc. is traversed sequentially in order to find the designated entity.
197 -- The discriminants of a type and the operations of a protected type or
198 -- task are unchained on exit from the first view of the type, (such as
199 -- a private or incomplete type declaration, or a protected type speci-
200 -- fication) and re-chained when compiling the second view.
202 -- In the case of operators, we do not make operators on derived types
203 -- explicit. As a result, the notation P."+" may denote either a user-
204 -- defined function with name "+", or else an implicit declaration of the
205 -- operator "+" in package P. The resolution of expanded names always
206 -- tries to resolve an operator name as such an implicitly defined entity,
207 -- in addition to looking for explicit declarations.
209 -- All forms of names that denote entities (simple names, expanded names,
210 -- character literals in some cases) have a Entity attribute, which
211 -- identifies the entity denoted by the name.
213 ---------------------
214 -- The Scope Stack --
215 ---------------------
217 -- The Scope stack keeps track of the scopes currently been compiled.
218 -- Every entity that contains declarations (including records) is placed
219 -- on the scope stack while it is being processed, and removed at the end.
220 -- Whenever a non-package scope is exited, the entities defined therein
221 -- are removed from the visibility table, so that entities in outer scopes
222 -- become visible (see previous description). On entry to Sem, the scope
223 -- stack only contains the package Standard. As usual, subunits complicate
224 -- this picture ever so slightly.
226 -- The Rtsfind mechanism can force a call to Semantics while another
227 -- compilation is in progress. The unit retrieved by Rtsfind must be
228 -- compiled in its own context, and has no access to the visibility of
229 -- the unit currently being compiled. The procedures Save_Scope_Stack and
230 -- Restore_Scope_Stack make entities in current open scopes invisible
231 -- before compiling the retrieved unit, and restore the compilation
232 -- environment afterwards.
234 ------------------------
235 -- Compiling subunits --
236 ------------------------
238 -- Subunits must be compiled in the environment of the corresponding stub,
239 -- that is to say with the same visibility into the parent (and its
240 -- context) that is available at the point of the stub declaration, but
241 -- with the additional visibility provided by the context clause of the
242 -- subunit itself. As a result, compilation of a subunit forces compilation
243 -- of the parent (see description in lib-). At the point of the stub
244 -- declaration, Analyze is called recursively to compile the proper body of
245 -- the subunit, but without reinitializing the names table, nor the scope
246 -- stack (i.e. standard is not pushed on the stack). In this fashion the
247 -- context of the subunit is added to the context of the parent, and the
248 -- subunit is compiled in the correct environment. Note that in the course
249 -- of processing the context of a subunit, Standard will appear twice on
250 -- the scope stack: once for the parent of the subunit, and once for the
251 -- unit in the context clause being compiled. However, the two sets of
252 -- entities are not linked by homonym chains, so that the compilation of
253 -- any context unit happens in a fresh visibility environment.
255 -------------------------------
256 -- Processing of USE Clauses --
257 -------------------------------
259 -- Every defining occurrence has a flag indicating if it is potentially use
260 -- visible. Resolution of simple names examines this flag. The processing
261 -- of use clauses consists in setting this flag on all visible entities
262 -- defined in the corresponding package. On exit from the scope of the use
263 -- clause, the corresponding flag must be reset. However, a package may
264 -- appear in several nested use clauses (pathological but legal, alas)
265 -- which forces us to use a slightly more involved scheme:
267 -- a) The defining occurrence for a package holds a flag -In_Use- to
268 -- indicate that it is currently in the scope of a use clause. If a
269 -- redundant use clause is encountered, then the corresponding occurrence
270 -- of the package name is flagged -Redundant_Use-.
272 -- b) On exit from a scope, the use clauses in its declarative part are
273 -- scanned. The visibility flag is reset in all entities declared in
274 -- package named in a use clause, as long as the package is not flagged
275 -- as being in a redundant use clause (in which case the outer use
276 -- clause is still in effect, and the direct visibility of its entities
277 -- must be retained).
279 -- Note that entities are not removed from their homonym chains on exit
280 -- from the package specification. A subsequent use clause does not need
281 -- to rechain the visible entities, but only to establish their direct
284 -----------------------------------
285 -- Handling private declarations --
286 -----------------------------------
288 -- The principle that each entity has a single defining occurrence clashes
289 -- with the presence of two separate definitions for private types: the
290 -- first is the private type declaration, and second is the full type
291 -- declaration. It is important that all references to the type point to
292 -- the same defining occurrence, namely the first one. To enforce the two
293 -- separate views of the entity, the corresponding information is swapped
294 -- between the two declarations. Outside of the package, the defining
295 -- occurrence only contains the private declaration information, while in
296 -- the private part and the body of the package the defining occurrence
297 -- contains the full declaration. To simplify the swap, the defining
298 -- occurrence that currently holds the private declaration points to the
299 -- full declaration. During semantic processing the defining occurrence
300 -- also points to a list of private dependents, that is to say access types
301 -- or composite types whose designated types or component types are
302 -- subtypes or derived types of the private type in question. After the
303 -- full declaration has been seen, the private dependents are updated to
304 -- indicate that they have full definitions.
306 ------------------------------------
307 -- Handling of Undefined Messages --
308 ------------------------------------
310 -- In normal mode, only the first use of an undefined identifier generates
311 -- a message. The table Urefs is used to record error messages that have
312 -- been issued so that second and subsequent ones do not generate further
313 -- messages. However, the second reference causes text to be added to the
314 -- original undefined message noting "(more references follow)". The
315 -- full error list option (-gnatf) forces messages to be generated for
316 -- every reference and disconnects the use of this table.
318 type Uref_Entry is record
320 -- Node for identifier for which original message was posted. The
321 -- Chars field of this identifier is used to detect later references
322 -- to the same identifier.
325 -- Records error message Id of original undefined message. Reset to
326 -- No_Error_Msg after the second occurrence, where it is used to add
327 -- text to the original message as described above.
330 -- Set if the message is not visible rather than undefined
333 -- Records location of error message. Used to make sure that we do
334 -- not consider a, b : undefined as two separate instances, which
335 -- would otherwise happen, since the parser converts this sequence
336 -- to a : undefined; b : undefined.
340 package Urefs is new Table.Table (
341 Table_Component_Type => Uref_Entry,
342 Table_Index_Type => Nat,
343 Table_Low_Bound => 1,
345 Table_Increment => 100,
346 Table_Name => "Urefs");
348 Candidate_Renaming : Entity_Id;
349 -- Holds a candidate interpretation that appears in a subprogram renaming
350 -- declaration and does not match the given specification, but matches at
351 -- least on the first formal. Allows better error message when given
352 -- specification omits defaulted parameters, a common error.
354 -----------------------
355 -- Local Subprograms --
356 -----------------------
358 procedure Analyze_Generic_Renaming
361 -- Common processing for all three kinds of generic renaming declarations.
362 -- Enter new name and indicate that it renames the generic unit.
364 procedure Analyze_Renamed_Character
368 -- Renamed entity is given by a character literal, which must belong
369 -- to the return type of the new entity. Is_Body indicates whether the
370 -- declaration is a renaming_as_body. If the original declaration has
371 -- already been frozen (because of an intervening body, e.g.) the body of
372 -- the function must be built now. The same applies to the following
373 -- various renaming procedures.
375 procedure Analyze_Renamed_Dereference
379 -- Renamed entity is given by an explicit dereference. Prefix must be a
380 -- conformant access_to_subprogram type.
382 procedure Analyze_Renamed_Entry
386 -- If the renamed entity in a subprogram renaming is an entry or protected
387 -- subprogram, build a body for the new entity whose only statement is a
388 -- call to the renamed entity.
390 procedure Analyze_Renamed_Family_Member
394 -- Used when the renamed entity is an indexed component. The prefix must
395 -- denote an entry family.
397 procedure Analyze_Renamed_Primitive_Operation
401 -- If the renamed entity in a subprogram renaming is a primitive operation
402 -- or a class-wide operation in prefix form, save the target object,
403 -- which must be added to the list of actuals in any subsequent call.
404 -- The renaming operation is intrinsic because the compiler must in
405 -- fact generate a wrapper for it (6.3.1 (10 1/2)).
407 procedure Attribute_Renaming (N : Node_Id);
408 -- Analyze renaming of attribute as subprogram. The renaming declaration N
409 -- is rewritten as a subprogram body that returns the attribute reference
410 -- applied to the formals of the function.
412 procedure Set_Entity_Or_Discriminal (N : Node_Id; E : Entity_Id);
413 -- Set Entity, with style check if need be. For a discriminant reference,
414 -- replace by the corresponding discriminal, i.e. the parameter of the
415 -- initialization procedure that corresponds to the discriminant.
417 procedure Check_Frozen_Renaming (N : Node_Id; Subp : Entity_Id);
418 -- A renaming_as_body may occur after the entity of the original decla-
419 -- ration has been frozen. In that case, the body of the new entity must
420 -- be built now, because the usual mechanism of building the renamed
421 -- body at the point of freezing will not work. Subp is the subprogram
422 -- for which N provides the Renaming_As_Body.
424 procedure Check_In_Previous_With_Clause
427 -- N is a use_package clause and Nam the package name, or N is a use_type
428 -- clause and Nam is the prefix of the type name. In either case, verify
429 -- that the package is visible at that point in the context: either it
430 -- appears in a previous with_clause, or because it is a fully qualified
431 -- name and the root ancestor appears in a previous with_clause.
433 procedure Check_Library_Unit_Renaming (N : Node_Id; Old_E : Entity_Id);
434 -- Verify that the entity in a renaming declaration that is a library unit
435 -- is itself a library unit and not a nested unit or subunit. Also check
436 -- that if the renaming is a child unit of a generic parent, then the
437 -- renamed unit must also be a child unit of that parent. Finally, verify
438 -- that a renamed generic unit is not an implicit child declared within
439 -- an instance of the parent.
441 procedure Chain_Use_Clause (N : Node_Id);
442 -- Chain use clause onto list of uses clauses headed by First_Use_Clause in
443 -- the proper scope table entry. This is usually the current scope, but it
444 -- will be an inner scope when installing the use clauses of the private
445 -- declarations of a parent unit prior to compiling the private part of a
446 -- child unit. This chain is traversed when installing/removing use clauses
447 -- when compiling a subunit or instantiating a generic body on the fly,
448 -- when it is necessary to save and restore full environments.
450 function Enclosing_Instance return Entity_Id;
451 -- In an instance nested within another one, several semantic checks are
452 -- unnecessary because the legality of the nested instance has been checked
453 -- in the enclosing generic unit. This applies in particular to legality
454 -- checks on actuals for formal subprograms of the inner instance, which
455 -- are checked as subprogram renamings, and may be complicated by confusion
456 -- in private/full views. This function returns the instance enclosing the
457 -- current one if there is such, else it returns Empty.
459 -- If the renaming determines the entity for the default of a formal
460 -- subprogram nested within another instance, choose the innermost
461 -- candidate. This is because if the formal has a box, and we are within
462 -- an enclosing instance where some candidate interpretations are local
463 -- to this enclosing instance, we know that the default was properly
464 -- resolved when analyzing the generic, so we prefer the local
465 -- candidates to those that are external. This is not always the case
466 -- but is a reasonable heuristic on the use of nested generics. The
467 -- proper solution requires a full renaming model.
469 function Entity_Of_Unit (U : Node_Id) return Entity_Id;
470 -- Return the appropriate entity for determining which unit has a deeper
471 -- scope: the defining entity for U, unless U is a package instance, in
472 -- which case we retrieve the entity of the instance spec.
474 procedure Find_Expanded_Name (N : Node_Id);
475 -- The input is a selected component known to be an expanded name. Verify
476 -- legality of selector given the scope denoted by prefix, and change node
477 -- N into a expanded name with a properly set Entity field.
479 function Find_Most_Prev (Use_Clause : Node_Id) return Node_Id;
480 -- Find the most previous use clause (that is, the first one to appear in
481 -- the source) by traversing the previous clause chain that exists in both
482 -- N_Use_Package_Clause nodes and N_Use_Type_Clause nodes.
483 -- ??? a better subprogram name is in order
485 function Find_Renamed_Entity
489 Is_Actual : Boolean := False) return Entity_Id;
490 -- Find the renamed entity that corresponds to the given parameter profile
491 -- in a subprogram renaming declaration. The renamed entity may be an
492 -- operator, a subprogram, an entry, or a protected operation. Is_Actual
493 -- indicates that the renaming is the one generated for an actual subpro-
494 -- gram in an instance, for which special visibility checks apply.
496 function Has_Implicit_Character_Literal (N : Node_Id) return Boolean;
497 -- Find a type derived from Character or Wide_Character in the prefix of N.
498 -- Used to resolved qualified names whose selector is a character literal.
500 function Has_Private_With (E : Entity_Id) return Boolean;
501 -- Ada 2005 (AI-262): Determines if the current compilation unit has a
502 -- private with on E.
504 function Has_Components (Typ : Entity_Id) return Boolean;
505 -- Determine if given type has components, i.e. is either a record type or
506 -- type or a type that has discriminants.
508 function Has_Implicit_Operator (N : Node_Id) return Boolean;
509 -- N is an expanded name whose selector is an operator name (e.g. P."+").
510 -- declarative part contains an implicit declaration of an operator if it
511 -- has a declaration of a type to which one of the predefined operators
512 -- apply. The existence of this routine is an implementation artifact. A
513 -- more straightforward but more space-consuming choice would be to make
514 -- all inherited operators explicit in the symbol table.
516 procedure Inherit_Renamed_Profile (New_S : Entity_Id; Old_S : Entity_Id);
517 -- A subprogram defined by a renaming declaration inherits the parameter
518 -- profile of the renamed entity. The subtypes given in the subprogram
519 -- specification are discarded and replaced with those of the renamed
520 -- subprogram, which are then used to recheck the default values.
522 function Most_Descendant_Use_Clause
523 (Clause1 : Entity_Id;
524 Clause2 : Entity_Id) return Entity_Id;
525 -- Determine which use clause parameter is the most descendant in terms of
527 -- ??? a better subprogram name is in order
529 procedure Premature_Usage (N : Node_Id);
530 -- Diagnose usage of an entity before it is visible
532 procedure Use_One_Package
534 Pack_Name : Entity_Id := Empty;
535 Force : Boolean := False);
536 -- Make visible entities declared in package P potentially use-visible
537 -- in the current context. Also used in the analysis of subunits, when
538 -- re-installing use clauses of parent units. N is the use_clause that
539 -- names P (and possibly other packages).
541 procedure Use_One_Type
543 Installed : Boolean := False;
544 Force : Boolean := False);
545 -- Id is the subtype mark from a use_type_clause. This procedure makes
546 -- the primitive operators of the type potentially use-visible. The
547 -- boolean flag Installed indicates that the clause is being reinstalled
548 -- after previous analysis, and primitive operations are already chained
549 -- on the Used_Operations list of the clause.
551 procedure Write_Info;
552 -- Write debugging information on entities declared in current scope
554 --------------------------------
555 -- Analyze_Exception_Renaming --
556 --------------------------------
558 -- The language only allows a single identifier, but the tree holds an
559 -- identifier list. The parser has already issued an error message if
560 -- there is more than one element in the list.
562 procedure Analyze_Exception_Renaming (N : Node_Id) is
563 Id : constant Entity_Id := Defining_Entity (N);
564 Nam : constant Node_Id := Name (N);
570 Set_Ekind (Id, E_Exception);
571 Set_Etype (Id, Standard_Exception_Type);
572 Set_Is_Pure (Id, Is_Pure (Current_Scope));
574 if Is_Entity_Name (Nam)
575 and then Present (Entity (Nam))
576 and then Ekind (Entity (Nam)) = E_Exception
578 if Present (Renamed_Object (Entity (Nam))) then
579 Set_Renamed_Object (Id, Renamed_Object (Entity (Nam)));
581 Set_Renamed_Object (Id, Entity (Nam));
584 -- The exception renaming declaration may become Ghost if it renames
587 Mark_Ghost_Renaming (N, Entity (Nam));
589 Error_Msg_N ("invalid exception name in renaming", Nam);
592 -- Implementation-defined aspect specifications can appear in a renaming
593 -- declaration, but not language-defined ones. The call to procedure
594 -- Analyze_Aspect_Specifications will take care of this error check.
596 if Has_Aspects (N) then
597 Analyze_Aspect_Specifications (N, Id);
599 end Analyze_Exception_Renaming;
601 ---------------------------
602 -- Analyze_Expanded_Name --
603 ---------------------------
605 procedure Analyze_Expanded_Name (N : Node_Id) is
607 -- If the entity pointer is already set, this is an internal node, or a
608 -- node that is analyzed more than once, after a tree modification. In
609 -- such a case there is no resolution to perform, just set the type. In
610 -- either case, start by analyzing the prefix.
612 Analyze (Prefix (N));
614 if Present (Entity (N)) then
615 if Is_Type (Entity (N)) then
616 Set_Etype (N, Entity (N));
618 Set_Etype (N, Etype (Entity (N)));
622 Find_Expanded_Name (N);
625 -- In either case, propagate dimension of entity to expanded name
627 Analyze_Dimension (N);
628 end Analyze_Expanded_Name;
630 ---------------------------------------
631 -- Analyze_Generic_Function_Renaming --
632 ---------------------------------------
634 procedure Analyze_Generic_Function_Renaming (N : Node_Id) is
636 Analyze_Generic_Renaming (N, E_Generic_Function);
637 end Analyze_Generic_Function_Renaming;
639 --------------------------------------
640 -- Analyze_Generic_Package_Renaming --
641 --------------------------------------
643 procedure Analyze_Generic_Package_Renaming (N : Node_Id) is
645 -- Test for the Text_IO special unit case here, since we may be renaming
646 -- one of the subpackages of Text_IO, then join common routine.
648 Check_Text_IO_Special_Unit (Name (N));
650 Analyze_Generic_Renaming (N, E_Generic_Package);
651 end Analyze_Generic_Package_Renaming;
653 ----------------------------------------
654 -- Analyze_Generic_Procedure_Renaming --
655 ----------------------------------------
657 procedure Analyze_Generic_Procedure_Renaming (N : Node_Id) is
659 Analyze_Generic_Renaming (N, E_Generic_Procedure);
660 end Analyze_Generic_Procedure_Renaming;
662 ------------------------------
663 -- Analyze_Generic_Renaming --
664 ------------------------------
666 procedure Analyze_Generic_Renaming
670 New_P : constant Entity_Id := Defining_Entity (N);
671 Inst : Boolean := False;
675 if Name (N) = Error then
679 Generate_Definition (New_P);
681 if Current_Scope /= Standard_Standard then
682 Set_Is_Pure (New_P, Is_Pure (Current_Scope));
685 if Nkind (Name (N)) = N_Selected_Component then
686 Check_Generic_Child_Unit (Name (N), Inst);
691 if not Is_Entity_Name (Name (N)) then
692 Error_Msg_N ("expect entity name in renaming declaration", Name (N));
695 Old_P := Entity (Name (N));
699 Set_Ekind (New_P, K);
701 if Etype (Old_P) = Any_Type then
704 elsif Ekind (Old_P) /= K then
705 Error_Msg_N ("invalid generic unit name", Name (N));
708 if Present (Renamed_Object (Old_P)) then
709 Set_Renamed_Object (New_P, Renamed_Object (Old_P));
711 Set_Renamed_Object (New_P, Old_P);
714 -- The generic renaming declaration may become Ghost if it renames a
717 Mark_Ghost_Renaming (N, Old_P);
719 Set_Is_Pure (New_P, Is_Pure (Old_P));
720 Set_Is_Preelaborated (New_P, Is_Preelaborated (Old_P));
722 Set_Etype (New_P, Etype (Old_P));
723 Set_Has_Completion (New_P);
725 if In_Open_Scopes (Old_P) then
726 Error_Msg_N ("within its scope, generic denotes its instance", N);
729 -- For subprograms, propagate the Intrinsic flag, to allow, e.g.
730 -- renamings and subsequent instantiations of Unchecked_Conversion.
732 if Ekind_In (Old_P, E_Generic_Function, E_Generic_Procedure) then
733 Set_Is_Intrinsic_Subprogram
734 (New_P, Is_Intrinsic_Subprogram (Old_P));
737 Check_Library_Unit_Renaming (N, Old_P);
740 -- Implementation-defined aspect specifications can appear in a renaming
741 -- declaration, but not language-defined ones. The call to procedure
742 -- Analyze_Aspect_Specifications will take care of this error check.
744 if Has_Aspects (N) then
745 Analyze_Aspect_Specifications (N, New_P);
747 end Analyze_Generic_Renaming;
749 -----------------------------
750 -- Analyze_Object_Renaming --
751 -----------------------------
753 procedure Analyze_Object_Renaming (N : Node_Id) is
754 Id : constant Entity_Id := Defining_Identifier (N);
755 Loc : constant Source_Ptr := Sloc (N);
756 Nam : constant Node_Id := Name (N);
757 Is_Object_Ref : Boolean := False;
762 procedure Check_Constrained_Object;
763 -- If the nominal type is unconstrained but the renamed object is
764 -- constrained, as can happen with renaming an explicit dereference or
765 -- a function return, build a constrained subtype from the object. If
766 -- the renaming is for a formal in an accept statement, the analysis
767 -- has already established its actual subtype. This is only relevant
768 -- if the renamed object is an explicit dereference.
770 function Get_Object_Name (Nod : Node_Id) return Node_Id;
771 -- Obtain the name of the object from node Nod which is being renamed by
772 -- the object renaming declaration N.
774 ------------------------------
775 -- Check_Constrained_Object --
776 ------------------------------
778 procedure Check_Constrained_Object is
779 Typ : constant Entity_Id := Etype (Nam);
783 if Nkind_In (Nam, N_Function_Call, N_Explicit_Dereference)
784 and then Is_Composite_Type (Typ)
785 and then not Is_Constrained (Typ)
786 and then not Has_Unknown_Discriminants (Typ)
787 and then Expander_Active
789 -- If Actual_Subtype is already set, nothing to do
791 if Ekind_In (Id, E_Variable, E_Constant)
792 and then Present (Actual_Subtype (Id))
796 -- A renaming of an unchecked union has no actual subtype
798 elsif Is_Unchecked_Union (Typ) then
801 -- If a record is limited its size is invariant. This is the case
802 -- in particular with record types with an access discriminant
803 -- that are used in iterators. This is an optimization, but it
804 -- also prevents typing anomalies when the prefix is further
806 -- Note that we cannot just use the Is_Limited_Record flag because
807 -- it does not apply to records with limited components, for which
808 -- this syntactic flag is not set, but whose size is also fixed.
810 elsif Is_Limited_Type (Typ) then
814 Subt := Make_Temporary (Loc, 'T');
815 Remove_Side_Effects (Nam);
817 Make_Subtype_Declaration (Loc,
818 Defining_Identifier => Subt,
819 Subtype_Indication =>
820 Make_Subtype_From_Expr (Nam, Typ)));
821 Rewrite (Subtype_Mark (N), New_Occurrence_Of (Subt, Loc));
822 Set_Etype (Nam, Subt);
824 -- Freeze subtype at once, to prevent order of elaboration
825 -- issues in the backend. The renamed object exists, so its
826 -- type is already frozen in any case.
828 Freeze_Before (N, Subt);
831 end Check_Constrained_Object;
833 ---------------------
834 -- Get_Object_Name --
835 ---------------------
837 function Get_Object_Name (Nod : Node_Id) return Node_Id is
842 while Present (Obj_Nam) loop
843 case Nkind (Obj_Nam) is
844 when N_Attribute_Reference
845 | N_Explicit_Dereference
846 | N_Indexed_Component
849 Obj_Nam := Prefix (Obj_Nam);
851 when N_Selected_Component =>
852 Obj_Nam := Selector_Name (Obj_Nam);
854 when N_Qualified_Expression | N_Type_Conversion =>
855 Obj_Nam := Expression (Obj_Nam);
865 -- Start of processing for Analyze_Object_Renaming
872 Set_Is_Pure (Id, Is_Pure (Current_Scope));
875 -- The renaming of a component that depends on a discriminant requires
876 -- an actual subtype, because in subsequent use of the object Gigi will
877 -- be unable to locate the actual bounds. This explicit step is required
878 -- when the renaming is generated in removing side effects of an
879 -- already-analyzed expression.
881 if Nkind (Nam) = N_Selected_Component and then Analyzed (Nam) then
883 -- The object renaming declaration may become Ghost if it renames a
886 if Is_Entity_Name (Nam) then
887 Mark_Ghost_Renaming (N, Entity (Nam));
891 Dec := Build_Actual_Subtype_Of_Component (Etype (Nam), Nam);
893 if Present (Dec) then
894 Insert_Action (N, Dec);
895 T := Defining_Identifier (Dec);
898 elsif Present (Subtype_Mark (N))
899 or else not Present (Access_Definition (N))
901 if Present (Subtype_Mark (N)) then
902 Find_Type (Subtype_Mark (N));
903 T := Entity (Subtype_Mark (N));
906 -- AI12-0275: Case of object renaming without a subtype_mark
911 -- Normal case of no overloading in object name
913 if not Is_Overloaded (Nam) then
915 -- Catch error cases (such as attempting to rename a procedure
916 -- or package) using the shorthand form.
919 or else Etype (Nam) = Standard_Void_Type
921 Error_Msg_N ("object name expected in renaming", Nam);
923 Set_Ekind (Id, E_Variable);
924 Set_Etype (Id, Any_Type);
932 -- Case of overloaded name, which will be illegal if there's more
933 -- than one acceptable interpretation (such as overloaded function
945 -- More than one candidate interpretation is available
947 -- Remove procedure calls, which syntactically cannot appear
948 -- in this context, but which cannot be removed by type
949 -- checking, because the context does not impose a type.
951 Get_First_Interp (Nam, I, It);
952 while Present (It.Typ) loop
953 if It.Typ = Standard_Void_Type then
957 Get_Next_Interp (I, It);
960 Get_First_Interp (Nam, I, It);
964 -- If there's no type present, we have an error case (such
965 -- as overloaded procedures named in the object renaming).
968 Error_Msg_N ("object name expected in renaming", Nam);
970 Set_Ekind (Id, E_Variable);
971 Set_Etype (Id, Any_Type);
976 Get_Next_Interp (I, It);
978 if Present (It.Typ) then
980 It1 := Disambiguate (Nam, I1, I, Any_Type);
982 if It1 = No_Interp then
983 Error_Msg_N ("ambiguous name in object renaming", Nam);
985 Error_Msg_Sloc := Sloc (It.Nam);
986 Error_Msg_N ("\\possible interpretation#!", Nam);
988 Error_Msg_Sloc := Sloc (Nam1);
989 Error_Msg_N ("\\possible interpretation#!", Nam);
995 Set_Etype (Nam, It1.Typ);
1001 -- The object renaming declaration may become Ghost if it renames a
1004 if Is_Entity_Name (Nam) then
1005 Mark_Ghost_Renaming (N, Entity (Nam));
1010 -- If the renamed object is a function call of a limited type,
1011 -- the expansion of the renaming is complicated by the presence
1012 -- of various temporaries and subtypes that capture constraints
1013 -- of the renamed object. Rewrite node as an object declaration,
1014 -- whose expansion is simpler. Given that the object is limited
1015 -- there is no copy involved and no performance hit.
1017 if Nkind (Nam) = N_Function_Call
1018 and then Is_Limited_View (Etype (Nam))
1019 and then not Is_Constrained (Etype (Nam))
1020 and then Comes_From_Source (N)
1023 Set_Ekind (Id, E_Constant);
1025 Make_Object_Declaration (Loc,
1026 Defining_Identifier => Id,
1027 Constant_Present => True,
1028 Object_Definition => New_Occurrence_Of (Etype (Nam), Loc),
1029 Expression => Relocate_Node (Nam)));
1033 -- Ada 2012 (AI05-149): Reject renaming of an anonymous access object
1034 -- when renaming declaration has a named access type. The Ada 2012
1035 -- coverage rules allow an anonymous access type in the context of
1036 -- an expected named general access type, but the renaming rules
1037 -- require the types to be the same. (An exception is when the type
1038 -- of the renaming is also an anonymous access type, which can only
1039 -- happen due to a renaming created by the expander.)
1041 if Nkind (Nam) = N_Type_Conversion
1042 and then not Comes_From_Source (Nam)
1043 and then Ekind (Etype (Expression (Nam))) in Anonymous_Access_Kind
1044 and then Ekind (T) not in Anonymous_Access_Kind
1046 Wrong_Type (Expression (Nam), T); -- Should we give better error???
1049 -- Check that a class-wide object is not being renamed as an object
1050 -- of a specific type. The test for access types is needed to exclude
1051 -- cases where the renamed object is a dynamically tagged access
1052 -- result, such as occurs in certain expansions.
1054 if Is_Tagged_Type (T) then
1055 Check_Dynamically_Tagged_Expression
1061 -- Ada 2005 (AI-230/AI-254): Access renaming
1063 else pragma Assert (Present (Access_Definition (N)));
1067 N => Access_Definition (N));
1071 -- The object renaming declaration may become Ghost if it renames a
1074 if Is_Entity_Name (Nam) then
1075 Mark_Ghost_Renaming (N, Entity (Nam));
1078 -- Ada 2005 AI05-105: if the declaration has an anonymous access
1079 -- type, the renamed object must also have an anonymous type, and
1080 -- this is a name resolution rule. This was implicit in the last part
1081 -- of the first sentence in 8.5.1(3/2), and is made explicit by this
1084 if not Is_Overloaded (Nam) then
1085 if Ekind (Etype (Nam)) /= Ekind (T) then
1087 ("expect anonymous access type in object renaming", N);
1094 Typ : Entity_Id := Empty;
1095 Seen : Boolean := False;
1098 Get_First_Interp (Nam, I, It);
1099 while Present (It.Typ) loop
1101 -- Renaming is ambiguous if more than one candidate
1102 -- interpretation is type-conformant with the context.
1104 if Ekind (It.Typ) = Ekind (T) then
1105 if Ekind (T) = E_Anonymous_Access_Subprogram_Type
1108 (Designated_Type (T), Designated_Type (It.Typ))
1114 ("ambiguous expression in renaming", Nam);
1117 elsif Ekind (T) = E_Anonymous_Access_Type
1119 Covers (Designated_Type (T), Designated_Type (It.Typ))
1125 ("ambiguous expression in renaming", Nam);
1129 if Covers (T, It.Typ) then
1131 Set_Etype (Nam, Typ);
1132 Set_Is_Overloaded (Nam, False);
1136 Get_Next_Interp (I, It);
1143 -- Do not perform the legality checks below when the resolution of
1144 -- the renaming name failed because the associated type is Any_Type.
1146 if Etype (Nam) = Any_Type then
1149 -- Ada 2005 (AI-231): In the case where the type is defined by an
1150 -- access_definition, the renamed entity shall be of an access-to-
1151 -- constant type if and only if the access_definition defines an
1152 -- access-to-constant type. ARM 8.5.1(4)
1154 elsif Constant_Present (Access_Definition (N))
1155 and then not Is_Access_Constant (Etype (Nam))
1158 ("(Ada 2005): the renamed object is not access-to-constant "
1159 & "(RM 8.5.1(6))", N);
1161 elsif not Constant_Present (Access_Definition (N))
1162 and then Is_Access_Constant (Etype (Nam))
1165 ("(Ada 2005): the renamed object is not access-to-variable "
1166 & "(RM 8.5.1(6))", N);
1169 if Is_Access_Subprogram_Type (Etype (Nam)) then
1170 Check_Subtype_Conformant
1171 (Designated_Type (T), Designated_Type (Etype (Nam)));
1173 elsif not Subtypes_Statically_Match
1174 (Designated_Type (T),
1175 Available_View (Designated_Type (Etype (Nam))))
1178 ("subtype of renamed object does not statically match", N);
1182 -- Special processing for renaming function return object. Some errors
1183 -- and warnings are produced only for calls that come from source.
1185 if Nkind (Nam) = N_Function_Call then
1188 -- Usage is illegal in Ada 83, but renamings are also introduced
1189 -- during expansion, and error does not apply to those.
1192 if Comes_From_Source (N) then
1194 ("(Ada 83) cannot rename function return object", Nam);
1197 -- In Ada 95, warn for odd case of renaming parameterless function
1198 -- call if this is not a limited type (where this is useful).
1201 if Warn_On_Object_Renames_Function
1202 and then No (Parameter_Associations (Nam))
1203 and then not Is_Limited_Type (Etype (Nam))
1204 and then Comes_From_Source (Nam)
1207 ("renaming function result object is suspicious?R?", Nam);
1209 ("\function & will be called only once?R?", Nam,
1210 Entity (Name (Nam)));
1211 Error_Msg_N -- CODEFIX
1212 ("\suggest using an initialized constant object "
1213 & "instead?R?", Nam);
1218 Check_Constrained_Object;
1220 -- An object renaming requires an exact match of the type. Class-wide
1221 -- matching is not allowed.
1223 if Is_Class_Wide_Type (T)
1224 and then Base_Type (Etype (Nam)) /= Base_Type (T)
1226 Wrong_Type (Nam, T);
1229 -- We must search for an actual subtype here so that the bounds of
1230 -- objects of unconstrained types don't get dropped on the floor - such
1231 -- as with renamings of formal parameters.
1233 T2 := Get_Actual_Subtype_If_Available (Nam);
1235 -- Ada 2005 (AI-326): Handle wrong use of incomplete type
1237 if Nkind (Nam) = N_Explicit_Dereference
1238 and then Ekind (Etype (T2)) = E_Incomplete_Type
1240 Error_Msg_NE ("invalid use of incomplete type&", Id, T2);
1243 elsif Ekind (Etype (T)) = E_Incomplete_Type then
1244 Error_Msg_NE ("invalid use of incomplete type&", Id, T);
1248 if Ada_Version >= Ada_2005 and then Nkind (Nam) in N_Has_Entity then
1250 Nam_Ent : constant Entity_Id := Entity (Get_Object_Name (Nam));
1251 Nam_Decl : constant Node_Id := Declaration_Node (Nam_Ent);
1254 if Has_Null_Exclusion (N)
1255 and then not Has_Null_Exclusion (Nam_Decl)
1257 -- Ada 2005 (AI-423): If the object name denotes a generic
1258 -- formal object of a generic unit G, and the object renaming
1259 -- declaration occurs within the body of G or within the body
1260 -- of a generic unit declared within the declarative region
1261 -- of G, then the declaration of the formal object of G must
1262 -- have a null exclusion or a null-excluding subtype.
1264 if Is_Formal_Object (Nam_Ent)
1265 and then In_Generic_Scope (Id)
1267 if not Can_Never_Be_Null (Etype (Nam_Ent)) then
1269 ("object does not exclude `NULL` "
1270 & "(RM 8.5.1(4.6/2))", N);
1272 elsif In_Package_Body (Scope (Id)) then
1274 ("formal object does not have a null exclusion"
1275 & "(RM 8.5.1(4.6/2))", N);
1278 -- Ada 2005 (AI-423): Otherwise, the subtype of the object name
1279 -- shall exclude null.
1281 elsif not Can_Never_Be_Null (Etype (Nam_Ent)) then
1283 ("object does not exclude `NULL` "
1284 & "(RM 8.5.1(4.6/2))", N);
1286 -- An instance is illegal if it contains a renaming that
1287 -- excludes null, and the actual does not. The renaming
1288 -- declaration has already indicated that the declaration
1289 -- of the renamed actual in the instance will raise
1290 -- constraint_error.
1292 elsif Nkind (Nam_Decl) = N_Object_Declaration
1293 and then In_Instance
1295 Present (Corresponding_Generic_Association (Nam_Decl))
1296 and then Nkind (Expression (Nam_Decl)) =
1297 N_Raise_Constraint_Error
1300 ("actual does not exclude `NULL` (RM 8.5.1(4.6/2))", N);
1302 -- Finally, if there is a null exclusion, the subtype mark
1303 -- must not be null-excluding.
1305 elsif No (Access_Definition (N))
1306 and then Can_Never_Be_Null (T)
1309 ("`NOT NULL` not allowed (& already excludes null)",
1314 elsif Can_Never_Be_Null (T)
1315 and then not Can_Never_Be_Null (Etype (Nam_Ent))
1318 ("object does not exclude `NULL` (RM 8.5.1(4.6/2))", N);
1320 elsif Has_Null_Exclusion (N)
1321 and then No (Access_Definition (N))
1322 and then Can_Never_Be_Null (T)
1325 ("`NOT NULL` not allowed (& already excludes null)", N, T);
1330 -- Set the Ekind of the entity, unless it has been set already, as is
1331 -- the case for the iteration object over a container with no variable
1332 -- indexing. In that case it's been marked as a constant, and we do not
1333 -- want to change it to a variable.
1335 if Ekind (Id) /= E_Constant then
1336 Set_Ekind (Id, E_Variable);
1339 -- Initialize the object size and alignment. Note that we used to call
1340 -- Init_Size_Align here, but that's wrong for objects which have only
1341 -- an Esize, not an RM_Size field.
1343 Init_Object_Size_Align (Id);
1345 -- If N comes from source then check that the original node is an
1346 -- object reference since there may have been several rewritting and
1347 -- folding. Do not do this for N_Function_Call or N_Explicit_Dereference
1348 -- which might correspond to rewrites of e.g. N_Selected_Component
1349 -- (for example Object.Method rewriting).
1350 -- If N does not come from source then assume the tree is properly
1351 -- formed and accept any object reference. In such cases we do support
1352 -- more cases of renamings anyway, so the actual check on which renaming
1353 -- is valid is better left to the code generator as a last sanity
1356 if Comes_From_Source (N) then
1357 if Nkind_In (Nam, N_Function_Call, N_Explicit_Dereference) then
1358 Is_Object_Ref := Is_Object_Reference (Nam);
1360 Is_Object_Ref := Is_Object_Reference (Original_Node (Nam));
1363 Is_Object_Ref := True;
1366 if T = Any_Type or else Etype (Nam) = Any_Type then
1369 -- Verify that the renamed entity is an object or function call.
1371 elsif Is_Object_Ref then
1372 if Comes_From_Source (N) then
1373 if Is_Dependent_Component_Of_Mutable_Object (Nam) then
1375 ("illegal renaming of discriminant-dependent component", Nam);
1378 -- If the renaming comes from source and the renamed object is a
1379 -- dereference, then mark the prefix as needing debug information,
1380 -- since it might have been rewritten hence internally generated
1381 -- and Debug_Renaming_Declaration will link the renaming to it.
1383 if Nkind (Nam) = N_Explicit_Dereference
1384 and then Is_Entity_Name (Prefix (Nam))
1386 Set_Debug_Info_Needed (Entity (Prefix (Nam)));
1390 -- Weird but legal, equivalent to renaming a function call. Illegal
1391 -- if the literal is the result of constant-folding an attribute
1392 -- reference that is not a function.
1394 elsif Is_Entity_Name (Nam)
1395 and then Ekind (Entity (Nam)) = E_Enumeration_Literal
1396 and then Nkind (Original_Node (Nam)) /= N_Attribute_Reference
1400 Error_Msg_N ("expect object name in renaming", Nam);
1405 if not Is_Variable (Nam) then
1406 Set_Ekind (Id, E_Constant);
1407 Set_Never_Set_In_Source (Id, True);
1408 Set_Is_True_Constant (Id, True);
1411 -- The entity of the renaming declaration needs to reflect whether the
1412 -- renamed object is atomic, independent, volatile or VFA. These flags
1413 -- are set on the renamed object in the RM legality sense.
1415 Set_Is_Atomic (Id, Is_Atomic_Object (Nam));
1416 Set_Is_Independent (Id, Is_Independent_Object (Nam));
1417 Set_Is_Volatile (Id, Is_Volatile_Object (Nam));
1418 Set_Is_Volatile_Full_Access (Id, Is_Volatile_Full_Access_Object (Nam));
1420 -- Treat as volatile if we just set the Volatile flag
1424 -- Or if we are renaming an entity which was marked this way
1426 -- Are there more cases, e.g. X(J) where X is Treat_As_Volatile ???
1428 or else (Is_Entity_Name (Nam)
1429 and then Treat_As_Volatile (Entity (Nam)))
1431 Set_Treat_As_Volatile (Id, True);
1434 -- Now make the link to the renamed object
1436 Set_Renamed_Object (Id, Nam);
1438 -- Implementation-defined aspect specifications can appear in a renaming
1439 -- declaration, but not language-defined ones. The call to procedure
1440 -- Analyze_Aspect_Specifications will take care of this error check.
1442 if Has_Aspects (N) then
1443 Analyze_Aspect_Specifications (N, Id);
1446 -- Deal with dimensions
1448 Analyze_Dimension (N);
1449 end Analyze_Object_Renaming;
1451 ------------------------------
1452 -- Analyze_Package_Renaming --
1453 ------------------------------
1455 procedure Analyze_Package_Renaming (N : Node_Id) is
1456 New_P : constant Entity_Id := Defining_Entity (N);
1461 if Name (N) = Error then
1465 -- Check for Text_IO special unit (we may be renaming a Text_IO child)
1467 Check_Text_IO_Special_Unit (Name (N));
1469 if Current_Scope /= Standard_Standard then
1470 Set_Is_Pure (New_P, Is_Pure (Current_Scope));
1476 if Is_Entity_Name (Name (N)) then
1477 Old_P := Entity (Name (N));
1482 if Etype (Old_P) = Any_Type then
1483 Error_Msg_N ("expect package name in renaming", Name (N));
1485 elsif Ekind (Old_P) /= E_Package
1486 and then not (Ekind (Old_P) = E_Generic_Package
1487 and then In_Open_Scopes (Old_P))
1489 if Ekind (Old_P) = E_Generic_Package then
1491 ("generic package cannot be renamed as a package", Name (N));
1493 Error_Msg_Sloc := Sloc (Old_P);
1495 ("expect package name in renaming, found& declared#",
1499 -- Set basic attributes to minimize cascaded errors
1501 Set_Ekind (New_P, E_Package);
1502 Set_Etype (New_P, Standard_Void_Type);
1504 -- Here for OK package renaming
1507 -- Entities in the old package are accessible through the renaming
1508 -- entity. The simplest implementation is to have both packages share
1511 Set_Ekind (New_P, E_Package);
1512 Set_Etype (New_P, Standard_Void_Type);
1514 if Present (Renamed_Object (Old_P)) then
1515 Set_Renamed_Object (New_P, Renamed_Object (Old_P));
1517 Set_Renamed_Object (New_P, Old_P);
1520 -- The package renaming declaration may become Ghost if it renames a
1523 Mark_Ghost_Renaming (N, Old_P);
1525 Set_Has_Completion (New_P);
1526 Set_First_Entity (New_P, First_Entity (Old_P));
1527 Set_Last_Entity (New_P, Last_Entity (Old_P));
1528 Set_First_Private_Entity (New_P, First_Private_Entity (Old_P));
1529 Check_Library_Unit_Renaming (N, Old_P);
1530 Generate_Reference (Old_P, Name (N));
1532 -- If the renaming is in the visible part of a package, then we set
1533 -- Renamed_In_Spec for the renamed package, to prevent giving
1534 -- warnings about no entities referenced. Such a warning would be
1535 -- overenthusiastic, since clients can see entities in the renamed
1536 -- package via the visible package renaming.
1539 Ent : constant Entity_Id := Cunit_Entity (Current_Sem_Unit);
1541 if Ekind (Ent) = E_Package
1542 and then not In_Private_Part (Ent)
1543 and then In_Extended_Main_Source_Unit (N)
1544 and then Ekind (Old_P) = E_Package
1546 Set_Renamed_In_Spec (Old_P);
1550 -- If this is the renaming declaration of a package instantiation
1551 -- within itself, it is the declaration that ends the list of actuals
1552 -- for the instantiation. At this point, the subtypes that rename
1553 -- the actuals are flagged as generic, to avoid spurious ambiguities
1554 -- if the actuals for two distinct formals happen to coincide. If
1555 -- the actual is a private type, the subtype has a private completion
1556 -- that is flagged in the same fashion.
1558 -- Resolution is identical to what is was in the original generic.
1559 -- On exit from the generic instance, these are turned into regular
1560 -- subtypes again, so they are compatible with types in their class.
1562 if not Is_Generic_Instance (Old_P) then
1565 Spec := Specification (Unit_Declaration_Node (Old_P));
1568 if Nkind (Spec) = N_Package_Specification
1569 and then Present (Generic_Parent (Spec))
1570 and then Old_P = Current_Scope
1571 and then Chars (New_P) = Chars (Generic_Parent (Spec))
1577 E := First_Entity (Old_P);
1578 while Present (E) and then E /= New_P loop
1580 and then Nkind (Parent (E)) = N_Subtype_Declaration
1582 Set_Is_Generic_Actual_Type (E);
1584 if Is_Private_Type (E)
1585 and then Present (Full_View (E))
1587 Set_Is_Generic_Actual_Type (Full_View (E));
1597 -- Implementation-defined aspect specifications can appear in a renaming
1598 -- declaration, but not language-defined ones. The call to procedure
1599 -- Analyze_Aspect_Specifications will take care of this error check.
1601 if Has_Aspects (N) then
1602 Analyze_Aspect_Specifications (N, New_P);
1604 end Analyze_Package_Renaming;
1606 -------------------------------
1607 -- Analyze_Renamed_Character --
1608 -------------------------------
1610 procedure Analyze_Renamed_Character
1615 C : constant Node_Id := Name (N);
1618 if Ekind (New_S) = E_Function then
1619 Resolve (C, Etype (New_S));
1622 Check_Frozen_Renaming (N, New_S);
1626 Error_Msg_N ("character literal can only be renamed as function", N);
1628 end Analyze_Renamed_Character;
1630 ---------------------------------
1631 -- Analyze_Renamed_Dereference --
1632 ---------------------------------
1634 procedure Analyze_Renamed_Dereference
1639 Nam : constant Node_Id := Name (N);
1640 P : constant Node_Id := Prefix (Nam);
1646 if not Is_Overloaded (P) then
1647 if Ekind (Etype (Nam)) /= E_Subprogram_Type
1648 or else not Type_Conformant (Etype (Nam), New_S)
1650 Error_Msg_N ("designated type does not match specification", P);
1659 Get_First_Interp (Nam, Ind, It);
1661 while Present (It.Nam) loop
1663 if Ekind (It.Nam) = E_Subprogram_Type
1664 and then Type_Conformant (It.Nam, New_S)
1666 if Typ /= Any_Id then
1667 Error_Msg_N ("ambiguous renaming", P);
1674 Get_Next_Interp (Ind, It);
1677 if Typ = Any_Type then
1678 Error_Msg_N ("designated type does not match specification", P);
1683 Check_Frozen_Renaming (N, New_S);
1687 end Analyze_Renamed_Dereference;
1689 ---------------------------
1690 -- Analyze_Renamed_Entry --
1691 ---------------------------
1693 procedure Analyze_Renamed_Entry
1698 Nam : constant Node_Id := Name (N);
1699 Sel : constant Node_Id := Selector_Name (Nam);
1700 Is_Actual : constant Boolean := Present (Corresponding_Formal_Spec (N));
1704 if Entity (Sel) = Any_Id then
1706 -- Selector is undefined on prefix. Error emitted already
1708 Set_Has_Completion (New_S);
1712 -- Otherwise find renamed entity and build body of New_S as a call to it
1714 Old_S := Find_Renamed_Entity (N, Selector_Name (Nam), New_S);
1716 if Old_S = Any_Id then
1717 Error_Msg_N (" no subprogram or entry matches specification", N);
1720 Check_Subtype_Conformant (New_S, Old_S, N);
1721 Generate_Reference (New_S, Defining_Entity (N), 'b');
1722 Style.Check_Identifier (Defining_Entity (N), New_S);
1725 -- Only mode conformance required for a renaming_as_declaration
1727 Check_Mode_Conformant (New_S, Old_S, N);
1730 Inherit_Renamed_Profile (New_S, Old_S);
1732 -- The prefix can be an arbitrary expression that yields a task or
1733 -- protected object, so it must be resolved.
1735 if Is_Access_Type (Etype (Prefix (Nam))) then
1736 Insert_Explicit_Dereference (Prefix (Nam));
1738 Resolve (Prefix (Nam), Scope (Old_S));
1741 Set_Convention (New_S, Convention (Old_S));
1742 Set_Has_Completion (New_S, Inside_A_Generic);
1744 -- AI05-0225: If the renamed entity is a procedure or entry of a
1745 -- protected object, the target object must be a variable.
1747 if Is_Protected_Type (Scope (Old_S))
1748 and then Ekind (New_S) = E_Procedure
1749 and then not Is_Variable (Prefix (Nam))
1753 ("target object of protected operation used as actual for "
1754 & "formal procedure must be a variable", Nam);
1757 ("target object of protected operation renamed as procedure, "
1758 & "must be a variable", Nam);
1763 Check_Frozen_Renaming (N, New_S);
1765 end Analyze_Renamed_Entry;
1767 -----------------------------------
1768 -- Analyze_Renamed_Family_Member --
1769 -----------------------------------
1771 procedure Analyze_Renamed_Family_Member
1776 Nam : constant Node_Id := Name (N);
1777 P : constant Node_Id := Prefix (Nam);
1781 if (Is_Entity_Name (P) and then Ekind (Entity (P)) = E_Entry_Family)
1782 or else (Nkind (P) = N_Selected_Component
1783 and then Ekind (Entity (Selector_Name (P))) = E_Entry_Family)
1785 if Is_Entity_Name (P) then
1786 Old_S := Entity (P);
1788 Old_S := Entity (Selector_Name (P));
1791 if not Entity_Matches_Spec (Old_S, New_S) then
1792 Error_Msg_N ("entry family does not match specification", N);
1795 Check_Subtype_Conformant (New_S, Old_S, N);
1796 Generate_Reference (New_S, Defining_Entity (N), 'b');
1797 Style.Check_Identifier (Defining_Entity (N), New_S);
1801 Error_Msg_N ("no entry family matches specification", N);
1804 Set_Has_Completion (New_S, Inside_A_Generic);
1807 Check_Frozen_Renaming (N, New_S);
1809 end Analyze_Renamed_Family_Member;
1811 -----------------------------------------
1812 -- Analyze_Renamed_Primitive_Operation --
1813 -----------------------------------------
1815 procedure Analyze_Renamed_Primitive_Operation
1825 Ctyp : Conformance_Type) return Boolean;
1826 -- Verify that the signatures of the renamed entity and the new entity
1827 -- match. The first formal of the renamed entity is skipped because it
1828 -- is the target object in any subsequent call.
1836 Ctyp : Conformance_Type) return Boolean
1842 if Ekind (Subp) /= Ekind (New_S) then
1846 Old_F := Next_Formal (First_Formal (Subp));
1847 New_F := First_Formal (New_S);
1848 while Present (Old_F) and then Present (New_F) loop
1849 if not Conforming_Types (Etype (Old_F), Etype (New_F), Ctyp) then
1853 if Ctyp >= Mode_Conformant
1854 and then Ekind (Old_F) /= Ekind (New_F)
1859 Next_Formal (New_F);
1860 Next_Formal (Old_F);
1866 -- Start of processing for Analyze_Renamed_Primitive_Operation
1869 if not Is_Overloaded (Selector_Name (Name (N))) then
1870 Old_S := Entity (Selector_Name (Name (N)));
1872 if not Conforms (Old_S, Type_Conformant) then
1877 -- Find the operation that matches the given signature
1885 Get_First_Interp (Selector_Name (Name (N)), Ind, It);
1887 while Present (It.Nam) loop
1888 if Conforms (It.Nam, Type_Conformant) then
1892 Get_Next_Interp (Ind, It);
1897 if Old_S = Any_Id then
1898 Error_Msg_N ("no subprogram or entry matches specification", N);
1902 if not Conforms (Old_S, Subtype_Conformant) then
1903 Error_Msg_N ("subtype conformance error in renaming", N);
1906 Generate_Reference (New_S, Defining_Entity (N), 'b');
1907 Style.Check_Identifier (Defining_Entity (N), New_S);
1910 -- Only mode conformance required for a renaming_as_declaration
1912 if not Conforms (Old_S, Mode_Conformant) then
1913 Error_Msg_N ("mode conformance error in renaming", N);
1916 -- AI12-0204: The prefix of a prefixed view that is renamed or
1917 -- passed as a formal subprogram must be renamable as an object.
1919 Nam := Prefix (Name (N));
1921 if Is_Object_Reference (Nam) then
1922 if Is_Dependent_Component_Of_Mutable_Object (Nam) then
1924 ("illegal renaming of discriminant-dependent component",
1928 Error_Msg_N ("expect object name in renaming", Nam);
1931 -- Enforce the rule given in (RM 6.3.1 (10.1/2)): a prefixed
1932 -- view of a subprogram is intrinsic, because the compiler has
1933 -- to generate a wrapper for any call to it. If the name in a
1934 -- subprogram renaming is a prefixed view, the entity is thus
1935 -- intrinsic, and 'Access cannot be applied to it.
1937 Set_Convention (New_S, Convention_Intrinsic);
1940 -- Inherit_Renamed_Profile (New_S, Old_S);
1942 -- The prefix can be an arbitrary expression that yields an
1943 -- object, so it must be resolved.
1945 Resolve (Prefix (Name (N)));
1947 end Analyze_Renamed_Primitive_Operation;
1949 ---------------------------------
1950 -- Analyze_Subprogram_Renaming --
1951 ---------------------------------
1953 procedure Analyze_Subprogram_Renaming (N : Node_Id) is
1954 Formal_Spec : constant Entity_Id := Corresponding_Formal_Spec (N);
1955 Is_Actual : constant Boolean := Present (Formal_Spec);
1956 Nam : constant Node_Id := Name (N);
1957 Save_AV : constant Ada_Version_Type := Ada_Version;
1958 Save_AVP : constant Node_Id := Ada_Version_Pragma;
1959 Save_AV_Exp : constant Ada_Version_Type := Ada_Version_Explicit;
1960 Spec : constant Node_Id := Specification (N);
1962 Old_S : Entity_Id := Empty;
1963 Rename_Spec : Entity_Id;
1965 procedure Build_Class_Wide_Wrapper
1966 (Ren_Id : out Entity_Id;
1967 Wrap_Id : out Entity_Id);
1968 -- Ada 2012 (AI05-0071): A generic/instance scenario involving a formal
1969 -- type with unknown discriminants and a generic primitive operation of
1970 -- the said type with a box require special processing when the actual
1971 -- is a class-wide type:
1974 -- type Formal_Typ (<>) is private;
1975 -- with procedure Prim_Op (Param : Formal_Typ) is <>;
1976 -- package Gen is ...
1978 -- package Inst is new Gen (Actual_Typ'Class);
1980 -- In this case the general renaming mechanism used in the prologue of
1981 -- an instance no longer applies:
1983 -- procedure Prim_Op (Param : Formal_Typ) renames Prim_Op;
1985 -- The above is replaced the following wrapper/renaming combination:
1987 -- procedure Wrapper (Param : Formal_Typ) is -- wrapper
1989 -- Prim_Op (Param); -- primitive
1992 -- procedure Prim_Op (Param : Formal_Typ) renames Wrapper;
1994 -- This transformation applies only if there is no explicit visible
1995 -- class-wide operation at the point of the instantiation. Ren_Id is
1996 -- the entity of the renaming declaration. When the transformation
1997 -- applies, Wrap_Id is the entity of the generated class-wide wrapper
1998 -- (or Any_Id). Otherwise, Wrap_Id is the entity of the class-wide
2001 procedure Check_Null_Exclusion
2004 -- Ada 2005 (AI-423): Given renaming Ren of subprogram Sub, check the
2005 -- following AI rules:
2007 -- If Ren is a renaming of a formal subprogram and one of its
2008 -- parameters has a null exclusion, then the corresponding formal
2009 -- in Sub must also have one. Otherwise the subtype of the Sub's
2010 -- formal parameter must exclude null.
2012 -- If Ren is a renaming of a formal function and its return
2013 -- profile has a null exclusion, then Sub's return profile must
2014 -- have one. Otherwise the subtype of Sub's return profile must
2017 procedure Check_SPARK_Primitive_Operation (Subp_Id : Entity_Id);
2018 -- Ensure that a SPARK renaming denoted by its entity Subp_Id does not
2019 -- declare a primitive operation of a tagged type (SPARK RM 6.1.1(3)).
2021 procedure Freeze_Actual_Profile;
2022 -- In Ada 2012, enforce the freezing rule concerning formal incomplete
2023 -- types: a callable entity freezes its profile, unless it has an
2024 -- incomplete untagged formal (RM 13.14(10.2/3)).
2026 function Has_Class_Wide_Actual return Boolean;
2027 -- Ada 2012 (AI05-071, AI05-0131): True if N is the renaming for a
2028 -- defaulted formal subprogram where the actual for the controlling
2029 -- formal type is class-wide.
2031 function Original_Subprogram (Subp : Entity_Id) return Entity_Id;
2032 -- Find renamed entity when the declaration is a renaming_as_body and
2033 -- the renamed entity may itself be a renaming_as_body. Used to enforce
2034 -- rule that a renaming_as_body is illegal if the declaration occurs
2035 -- before the subprogram it completes is frozen, and renaming indirectly
2036 -- renames the subprogram itself.(Defect Report 8652/0027).
2038 ------------------------------
2039 -- Build_Class_Wide_Wrapper --
2040 ------------------------------
2042 procedure Build_Class_Wide_Wrapper
2043 (Ren_Id : out Entity_Id;
2044 Wrap_Id : out Entity_Id)
2046 Loc : constant Source_Ptr := Sloc (N);
2049 (Subp_Id : Entity_Id;
2050 Params : List_Id) return Node_Id;
2051 -- Create a dispatching call to invoke routine Subp_Id with actuals
2052 -- built from the parameter specifications of list Params.
2054 function Build_Expr_Fun_Call
2055 (Subp_Id : Entity_Id;
2056 Params : List_Id) return Node_Id;
2057 -- Create a dispatching call to invoke function Subp_Id with actuals
2058 -- built from the parameter specifications of list Params. Return
2059 -- directly the call, so that it can be used inside an expression
2060 -- function. This is a specificity of the GNATprove mode.
2062 function Build_Spec (Subp_Id : Entity_Id) return Node_Id;
2063 -- Create a subprogram specification based on the subprogram profile
2066 function Find_Primitive (Typ : Entity_Id) return Entity_Id;
2067 -- Find a primitive subprogram of type Typ which matches the profile
2068 -- of the renaming declaration.
2070 procedure Interpretation_Error (Subp_Id : Entity_Id);
2071 -- Emit a continuation error message suggesting subprogram Subp_Id as
2072 -- a possible interpretation.
2074 function Is_Intrinsic_Equality (Subp_Id : Entity_Id) return Boolean;
2075 -- Determine whether subprogram Subp_Id denotes the intrinsic "="
2078 function Is_Suitable_Candidate (Subp_Id : Entity_Id) return Boolean;
2079 -- Determine whether subprogram Subp_Id is a suitable candidate for
2080 -- the role of a wrapped subprogram.
2087 (Subp_Id : Entity_Id;
2088 Params : List_Id) return Node_Id
2090 Actuals : constant List_Id := New_List;
2091 Call_Ref : constant Node_Id := New_Occurrence_Of (Subp_Id, Loc);
2095 -- Build the actual parameters of the call
2097 Formal := First (Params);
2098 while Present (Formal) loop
2100 Make_Identifier (Loc, Chars (Defining_Identifier (Formal))));
2105 -- return Subp_Id (Actuals);
2107 if Ekind_In (Subp_Id, E_Function, E_Operator) then
2109 Make_Simple_Return_Statement (Loc,
2111 Make_Function_Call (Loc,
2113 Parameter_Associations => Actuals));
2116 -- Subp_Id (Actuals);
2120 Make_Procedure_Call_Statement (Loc,
2122 Parameter_Associations => Actuals);
2126 -------------------------
2127 -- Build_Expr_Fun_Call --
2128 -------------------------
2130 function Build_Expr_Fun_Call
2131 (Subp_Id : Entity_Id;
2132 Params : List_Id) return Node_Id
2134 Actuals : constant List_Id := New_List;
2135 Call_Ref : constant Node_Id := New_Occurrence_Of (Subp_Id, Loc);
2139 pragma Assert (Ekind_In (Subp_Id, E_Function, E_Operator));
2141 -- Build the actual parameters of the call
2143 Formal := First (Params);
2144 while Present (Formal) loop
2146 Make_Identifier (Loc, Chars (Defining_Identifier (Formal))));
2151 -- Subp_Id (Actuals);
2154 Make_Function_Call (Loc,
2156 Parameter_Associations => Actuals);
2157 end Build_Expr_Fun_Call;
2163 function Build_Spec (Subp_Id : Entity_Id) return Node_Id is
2164 Params : constant List_Id := Copy_Parameter_List (Subp_Id);
2165 Spec_Id : constant Entity_Id :=
2166 Make_Defining_Identifier (Loc,
2167 Chars => New_External_Name (Chars (Subp_Id), 'R'));
2170 if Ekind (Formal_Spec) = E_Procedure then
2172 Make_Procedure_Specification (Loc,
2173 Defining_Unit_Name => Spec_Id,
2174 Parameter_Specifications => Params);
2177 Make_Function_Specification (Loc,
2178 Defining_Unit_Name => Spec_Id,
2179 Parameter_Specifications => Params,
2180 Result_Definition =>
2181 New_Copy_Tree (Result_Definition (Spec)));
2185 --------------------
2186 -- Find_Primitive --
2187 --------------------
2189 function Find_Primitive (Typ : Entity_Id) return Entity_Id is
2190 procedure Replace_Parameter_Types (Spec : Node_Id);
2191 -- Given a specification Spec, replace all class-wide parameter
2192 -- types with reference to type Typ.
2194 -----------------------------
2195 -- Replace_Parameter_Types --
2196 -----------------------------
2198 procedure Replace_Parameter_Types (Spec : Node_Id) is
2200 Formal_Id : Entity_Id;
2201 Formal_Typ : Node_Id;
2204 Formal := First (Parameter_Specifications (Spec));
2205 while Present (Formal) loop
2206 Formal_Id := Defining_Identifier (Formal);
2207 Formal_Typ := Parameter_Type (Formal);
2209 -- Create a new entity for each class-wide formal to prevent
2210 -- aliasing with the original renaming. Replace the type of
2211 -- such a parameter with the candidate type.
2213 if Nkind (Formal_Typ) = N_Identifier
2214 and then Is_Class_Wide_Type (Etype (Formal_Typ))
2216 Set_Defining_Identifier (Formal,
2217 Make_Defining_Identifier (Loc, Chars (Formal_Id)));
2219 Set_Parameter_Type (Formal, New_Occurrence_Of (Typ, Loc));
2224 end Replace_Parameter_Types;
2228 Alt_Ren : constant Node_Id := New_Copy_Tree (N);
2229 Alt_Nam : constant Node_Id := Name (Alt_Ren);
2230 Alt_Spec : constant Node_Id := Specification (Alt_Ren);
2231 Subp_Id : Entity_Id;
2233 -- Start of processing for Find_Primitive
2236 -- Each attempt to find a suitable primitive of a particular type
2237 -- operates on its own copy of the original renaming. As a result
2238 -- the original renaming is kept decoration and side-effect free.
2240 -- Inherit the overloaded status of the renamed subprogram name
2242 if Is_Overloaded (Nam) then
2243 Set_Is_Overloaded (Alt_Nam);
2244 Save_Interps (Nam, Alt_Nam);
2247 -- The copied renaming is hidden from visibility to prevent the
2248 -- pollution of the enclosing context.
2250 Set_Defining_Unit_Name (Alt_Spec, Make_Temporary (Loc, 'R'));
2252 -- The types of all class-wide parameters must be changed to the
2255 Replace_Parameter_Types (Alt_Spec);
2257 -- Try to find a suitable primitive which matches the altered
2258 -- profile of the renaming specification.
2263 Nam => Name (Alt_Ren),
2264 New_S => Analyze_Subprogram_Specification (Alt_Spec),
2265 Is_Actual => Is_Actual);
2267 -- Do not return Any_Id if the resolion of the altered profile
2268 -- failed as this complicates further checks on the caller side,
2269 -- return Empty instead.
2271 if Subp_Id = Any_Id then
2278 --------------------------
2279 -- Interpretation_Error --
2280 --------------------------
2282 procedure Interpretation_Error (Subp_Id : Entity_Id) is
2284 Error_Msg_Sloc := Sloc (Subp_Id);
2286 if Is_Internal (Subp_Id) then
2288 ("\\possible interpretation: predefined & #",
2292 ("\\possible interpretation: & defined #", Spec, Formal_Spec);
2294 end Interpretation_Error;
2296 ---------------------------
2297 -- Is_Intrinsic_Equality --
2298 ---------------------------
2300 function Is_Intrinsic_Equality (Subp_Id : Entity_Id) return Boolean is
2303 Ekind (Subp_Id) = E_Operator
2304 and then Chars (Subp_Id) = Name_Op_Eq
2305 and then Is_Intrinsic_Subprogram (Subp_Id);
2306 end Is_Intrinsic_Equality;
2308 ---------------------------
2309 -- Is_Suitable_Candidate --
2310 ---------------------------
2312 function Is_Suitable_Candidate (Subp_Id : Entity_Id) return Boolean is
2314 if No (Subp_Id) then
2317 -- An intrinsic subprogram is never a good candidate. This is an
2318 -- indication of a missing primitive, either defined directly or
2319 -- inherited from a parent tagged type.
2321 elsif Is_Intrinsic_Subprogram (Subp_Id) then
2327 end Is_Suitable_Candidate;
2331 Actual_Typ : Entity_Id := Empty;
2332 -- The actual class-wide type for Formal_Typ
2334 CW_Prim_OK : Boolean;
2335 CW_Prim_Op : Entity_Id;
2336 -- The class-wide subprogram (if available) which corresponds to the
2337 -- renamed generic formal subprogram.
2339 Formal_Typ : Entity_Id := Empty;
2340 -- The generic formal type with unknown discriminants
2342 Root_Prim_OK : Boolean;
2343 Root_Prim_Op : Entity_Id;
2344 -- The root type primitive (if available) which corresponds to the
2345 -- renamed generic formal subprogram.
2347 Root_Typ : Entity_Id := Empty;
2348 -- The root type of Actual_Typ
2350 Body_Decl : Node_Id;
2352 Prim_Op : Entity_Id;
2353 Spec_Decl : Node_Id;
2356 -- Start of processing for Build_Class_Wide_Wrapper
2359 -- Analyze the specification of the renaming in case the generation
2360 -- of the class-wide wrapper fails.
2362 Ren_Id := Analyze_Subprogram_Specification (Spec);
2365 -- Do not attempt to build a wrapper if the renaming is in error
2367 if Error_Posted (Nam) then
2371 -- Analyze the renamed name, but do not resolve it. The resolution is
2372 -- completed once a suitable subprogram is found.
2376 -- When the renamed name denotes the intrinsic operator equals, the
2377 -- name must be treated as overloaded. This allows for a potential
2378 -- match against the root type's predefined equality function.
2380 if Is_Intrinsic_Equality (Entity (Nam)) then
2381 Set_Is_Overloaded (Nam);
2382 Collect_Interps (Nam);
2385 -- Step 1: Find the generic formal type with unknown discriminants
2386 -- and its corresponding class-wide actual type from the renamed
2387 -- generic formal subprogram.
2389 Formal := First_Formal (Formal_Spec);
2390 while Present (Formal) loop
2391 if Has_Unknown_Discriminants (Etype (Formal))
2392 and then not Is_Class_Wide_Type (Etype (Formal))
2393 and then Is_Class_Wide_Type (Get_Instance_Of (Etype (Formal)))
2395 Formal_Typ := Etype (Formal);
2396 Actual_Typ := Get_Instance_Of (Formal_Typ);
2397 Root_Typ := Etype (Actual_Typ);
2401 Next_Formal (Formal);
2404 -- The specification of the generic formal subprogram should always
2405 -- contain a formal type with unknown discriminants whose actual is
2406 -- a class-wide type, otherwise this indicates a failure in routine
2407 -- Has_Class_Wide_Actual.
2409 pragma Assert (Present (Formal_Typ));
2411 -- Step 2: Find the proper class-wide subprogram or primitive which
2412 -- corresponds to the renamed generic formal subprogram.
2414 CW_Prim_Op := Find_Primitive (Actual_Typ);
2415 CW_Prim_OK := Is_Suitable_Candidate (CW_Prim_Op);
2416 Root_Prim_Op := Find_Primitive (Root_Typ);
2417 Root_Prim_OK := Is_Suitable_Candidate (Root_Prim_Op);
2419 -- The class-wide actual type has two subprograms which correspond to
2420 -- the renamed generic formal subprogram:
2422 -- with procedure Prim_Op (Param : Formal_Typ);
2424 -- procedure Prim_Op (Param : Actual_Typ); -- may be inherited
2425 -- procedure Prim_Op (Param : Actual_Typ'Class);
2427 -- Even though the declaration of the two subprograms is legal, a
2428 -- call to either one is ambiguous and therefore illegal.
2430 if CW_Prim_OK and Root_Prim_OK then
2432 -- A user-defined primitive has precedence over a predefined one
2434 if Is_Internal (CW_Prim_Op)
2435 and then not Is_Internal (Root_Prim_Op)
2437 Prim_Op := Root_Prim_Op;
2439 elsif Is_Internal (Root_Prim_Op)
2440 and then not Is_Internal (CW_Prim_Op)
2442 Prim_Op := CW_Prim_Op;
2444 elsif CW_Prim_Op = Root_Prim_Op then
2445 Prim_Op := Root_Prim_Op;
2447 -- Otherwise both candidate subprograms are user-defined and
2452 ("ambiguous actual for generic subprogram &",
2454 Interpretation_Error (Root_Prim_Op);
2455 Interpretation_Error (CW_Prim_Op);
2459 elsif CW_Prim_OK and not Root_Prim_OK then
2460 Prim_Op := CW_Prim_Op;
2462 elsif not CW_Prim_OK and Root_Prim_OK then
2463 Prim_Op := Root_Prim_Op;
2465 -- An intrinsic equality may act as a suitable candidate in the case
2466 -- of a null type extension where the parent's equality is hidden. A
2467 -- call to an intrinsic equality is expanded as dispatching.
2469 elsif Present (Root_Prim_Op)
2470 and then Is_Intrinsic_Equality (Root_Prim_Op)
2472 Prim_Op := Root_Prim_Op;
2474 -- Otherwise there are no candidate subprograms. Let the caller
2475 -- diagnose the error.
2481 -- At this point resolution has taken place and the name is no longer
2482 -- overloaded. Mark the primitive as referenced.
2484 Set_Is_Overloaded (Name (N), False);
2485 Set_Referenced (Prim_Op);
2487 -- Do not generate a wrapper when the only candidate is a class-wide
2488 -- subprogram. Instead modify the renaming to directly map the actual
2489 -- to the generic formal.
2491 if CW_Prim_OK and then Prim_Op = CW_Prim_Op then
2493 Rewrite (Nam, New_Occurrence_Of (Prim_Op, Loc));
2497 -- Step 3: Create the declaration and the body of the wrapper, insert
2498 -- all the pieces into the tree.
2500 -- In GNATprove mode, create a function wrapper in the form of an
2501 -- expression function, so that an implicit postcondition relating
2502 -- the result of calling the wrapper function and the result of the
2503 -- dispatching call to the wrapped function is known during proof.
2506 and then Ekind_In (Ren_Id, E_Function, E_Operator)
2508 New_Spec := Build_Spec (Ren_Id);
2510 Make_Expression_Function (Loc,
2511 Specification => New_Spec,
2514 (Subp_Id => Prim_Op,
2515 Params => Parameter_Specifications (New_Spec)));
2517 Wrap_Id := Defining_Entity (Body_Decl);
2519 -- Otherwise, create separate spec and body for the subprogram
2523 Make_Subprogram_Declaration (Loc,
2524 Specification => Build_Spec (Ren_Id));
2525 Insert_Before_And_Analyze (N, Spec_Decl);
2527 Wrap_Id := Defining_Entity (Spec_Decl);
2530 Make_Subprogram_Body (Loc,
2531 Specification => Build_Spec (Ren_Id),
2532 Declarations => New_List,
2533 Handled_Statement_Sequence =>
2534 Make_Handled_Sequence_Of_Statements (Loc,
2535 Statements => New_List (
2537 (Subp_Id => Prim_Op,
2539 Parameter_Specifications
2540 (Specification (Spec_Decl))))));
2542 Set_Corresponding_Body (Spec_Decl, Defining_Entity (Body_Decl));
2545 -- If the operator carries an Eliminated pragma, indicate that the
2546 -- wrapper is also to be eliminated, to prevent spurious error when
2547 -- using gnatelim on programs that include box-initialization of
2548 -- equality operators.
2550 Set_Is_Eliminated (Wrap_Id, Is_Eliminated (Prim_Op));
2552 -- In GNATprove mode, insert the body in the tree for analysis
2554 if GNATprove_Mode then
2555 Insert_Before_And_Analyze (N, Body_Decl);
2558 -- The generated body does not freeze and must be analyzed when the
2559 -- class-wide wrapper is frozen. The body is only needed if expansion
2562 if Expander_Active then
2563 Append_Freeze_Action (Wrap_Id, Body_Decl);
2566 -- Step 4: The subprogram renaming aliases the wrapper
2568 Rewrite (Nam, New_Occurrence_Of (Wrap_Id, Loc));
2569 end Build_Class_Wide_Wrapper;
2571 --------------------------
2572 -- Check_Null_Exclusion --
2573 --------------------------
2575 procedure Check_Null_Exclusion
2579 Ren_Formal : Entity_Id;
2580 Sub_Formal : Entity_Id;
2585 Ren_Formal := First_Formal (Ren);
2586 Sub_Formal := First_Formal (Sub);
2587 while Present (Ren_Formal) and then Present (Sub_Formal) loop
2588 if Has_Null_Exclusion (Parent (Ren_Formal))
2590 not (Has_Null_Exclusion (Parent (Sub_Formal))
2591 or else Can_Never_Be_Null (Etype (Sub_Formal)))
2594 ("`NOT NULL` required for parameter &",
2595 Parent (Sub_Formal), Sub_Formal);
2598 Next_Formal (Ren_Formal);
2599 Next_Formal (Sub_Formal);
2602 -- Return profile check
2604 if Nkind (Parent (Ren)) = N_Function_Specification
2605 and then Nkind (Parent (Sub)) = N_Function_Specification
2606 and then Has_Null_Exclusion (Parent (Ren))
2607 and then not (Has_Null_Exclusion (Parent (Sub))
2608 or else Can_Never_Be_Null (Etype (Sub)))
2611 ("return must specify `NOT NULL`",
2612 Result_Definition (Parent (Sub)));
2614 end Check_Null_Exclusion;
2616 -------------------------------------
2617 -- Check_SPARK_Primitive_Operation --
2618 -------------------------------------
2620 procedure Check_SPARK_Primitive_Operation (Subp_Id : Entity_Id) is
2621 Prag : constant Node_Id := SPARK_Pragma (Subp_Id);
2625 -- Nothing to do when the subprogram is not subject to SPARK_Mode On
2626 -- because this check applies to SPARK code only.
2628 if not (Present (Prag)
2629 and then Get_SPARK_Mode_From_Annotation (Prag) = On)
2633 -- Nothing to do when the subprogram is not a primitive operation
2635 elsif not Is_Primitive (Subp_Id) then
2639 Typ := Find_Dispatching_Type (Subp_Id);
2641 -- Nothing to do when the subprogram is a primitive operation of an
2648 -- At this point a renaming declaration introduces a new primitive
2649 -- operation for a tagged type.
2651 Error_Msg_Node_2 := Typ;
2653 ("subprogram renaming & cannot declare primitive for type & "
2654 & "(SPARK RM 6.1.1(3))", N, Subp_Id);
2655 end Check_SPARK_Primitive_Operation;
2657 ---------------------------
2658 -- Freeze_Actual_Profile --
2659 ---------------------------
2661 procedure Freeze_Actual_Profile is
2663 Has_Untagged_Inc : Boolean;
2664 Instantiation_Node : constant Node_Id := Parent (N);
2667 if Ada_Version >= Ada_2012 then
2668 F := First_Formal (Formal_Spec);
2669 Has_Untagged_Inc := False;
2670 while Present (F) loop
2671 if Ekind (Etype (F)) = E_Incomplete_Type
2672 and then not Is_Tagged_Type (Etype (F))
2674 Has_Untagged_Inc := True;
2681 if Ekind (Formal_Spec) = E_Function
2682 and then not Is_Tagged_Type (Etype (Formal_Spec))
2684 Has_Untagged_Inc := True;
2687 if not Has_Untagged_Inc then
2688 F := First_Formal (Old_S);
2689 while Present (F) loop
2690 Freeze_Before (Instantiation_Node, Etype (F));
2692 if Is_Incomplete_Or_Private_Type (Etype (F))
2693 and then No (Underlying_Type (Etype (F)))
2695 -- Exclude generic types, or types derived from them.
2696 -- They will be frozen in the enclosing instance.
2698 if Is_Generic_Type (Etype (F))
2699 or else Is_Generic_Type (Root_Type (Etype (F)))
2703 -- A limited view of a type declared elsewhere needs no
2704 -- freezing actions.
2706 elsif From_Limited_With (Etype (F)) then
2711 ("type& must be frozen before this point",
2712 Instantiation_Node, Etype (F));
2720 end Freeze_Actual_Profile;
2722 ---------------------------
2723 -- Has_Class_Wide_Actual --
2724 ---------------------------
2726 function Has_Class_Wide_Actual return Boolean is
2728 Formal_Typ : Entity_Id;
2732 Formal := First_Formal (Formal_Spec);
2733 while Present (Formal) loop
2734 Formal_Typ := Etype (Formal);
2736 if Has_Unknown_Discriminants (Formal_Typ)
2737 and then not Is_Class_Wide_Type (Formal_Typ)
2738 and then Is_Class_Wide_Type (Get_Instance_Of (Formal_Typ))
2743 Next_Formal (Formal);
2748 end Has_Class_Wide_Actual;
2750 -------------------------
2751 -- Original_Subprogram --
2752 -------------------------
2754 function Original_Subprogram (Subp : Entity_Id) return Entity_Id is
2755 Orig_Decl : Node_Id;
2756 Orig_Subp : Entity_Id;
2759 -- First case: renamed entity is itself a renaming
2761 if Present (Alias (Subp)) then
2762 return Alias (Subp);
2764 elsif Nkind (Unit_Declaration_Node (Subp)) = N_Subprogram_Declaration
2765 and then Present (Corresponding_Body (Unit_Declaration_Node (Subp)))
2767 -- Check if renamed entity is a renaming_as_body
2770 Unit_Declaration_Node
2771 (Corresponding_Body (Unit_Declaration_Node (Subp)));
2773 if Nkind (Orig_Decl) = N_Subprogram_Renaming_Declaration then
2774 Orig_Subp := Entity (Name (Orig_Decl));
2776 if Orig_Subp = Rename_Spec then
2778 -- Circularity detected
2783 return (Original_Subprogram (Orig_Subp));
2791 end Original_Subprogram;
2795 CW_Actual : constant Boolean := Has_Class_Wide_Actual;
2796 -- Ada 2012 (AI05-071, AI05-0131): True if the renaming is for a
2797 -- defaulted formal subprogram when the actual for a related formal
2798 -- type is class-wide.
2800 Inst_Node : Node_Id := Empty;
2803 -- Start of processing for Analyze_Subprogram_Renaming
2806 -- We must test for the attribute renaming case before the Analyze
2807 -- call because otherwise Sem_Attr will complain that the attribute
2808 -- is missing an argument when it is analyzed.
2810 if Nkind (Nam) = N_Attribute_Reference then
2812 -- In the case of an abstract formal subprogram association, rewrite
2813 -- an actual given by a stream or Put_Image attribute as the name of
2814 -- the corresponding stream or Put_Image primitive of the type.
2816 -- In a generic context the stream and Put_Image operations are not
2817 -- generated, and this must be treated as a normal attribute
2818 -- reference, to be expanded in subsequent instantiations.
2821 and then Is_Abstract_Subprogram (Formal_Spec)
2822 and then Expander_Active
2825 Prefix_Type : constant Entity_Id := Entity (Prefix (Nam));
2829 -- The class-wide forms of the stream and Put_Image attributes
2830 -- are not primitive dispatching operations (even though they
2831 -- internally dispatch).
2833 if Is_Class_Wide_Type (Prefix_Type) then
2835 ("attribute must be a primitive dispatching operation",
2840 -- Retrieve the primitive subprogram associated with the
2841 -- attribute. This can only be a stream attribute, since those
2842 -- are the only ones that are dispatching (and the actual for
2843 -- an abstract formal subprogram must be dispatching
2846 case Attribute_Name (Nam) is
2849 Find_Optional_Prim_Op (Prefix_Type, TSS_Stream_Input);
2853 Find_Optional_Prim_Op (Prefix_Type, TSS_Stream_Output);
2857 Find_Optional_Prim_Op (Prefix_Type, TSS_Stream_Read);
2861 Find_Optional_Prim_Op (Prefix_Type, TSS_Stream_Write);
2863 when Name_Put_Image =>
2865 Find_Optional_Prim_Op (Prefix_Type, TSS_Put_Image);
2869 ("attribute must be a primitive dispatching operation",
2874 -- If no stream operation was found, and the type is limited,
2875 -- the user should have defined one. This rule does not apply
2879 and then Attribute_Name (Nam) /= Name_Put_Image
2881 if Is_Limited_Type (Prefix_Type) then
2883 ("stream operation not defined for type&",
2887 -- Otherwise, compiler should have generated default
2890 raise Program_Error;
2894 -- Rewrite the attribute into the name of its corresponding
2895 -- primitive dispatching subprogram. We can then proceed with
2896 -- the usual processing for subprogram renamings.
2899 Prim_Name : constant Node_Id :=
2900 Make_Identifier (Sloc (Nam),
2901 Chars => Chars (Prim));
2903 Set_Entity (Prim_Name, Prim);
2904 Rewrite (Nam, Prim_Name);
2909 -- Normal processing for a renaming of an attribute
2912 Attribute_Renaming (N);
2917 -- Check whether this declaration corresponds to the instantiation of a
2918 -- formal subprogram.
2920 -- If this is an instantiation, the corresponding actual is frozen and
2921 -- error messages can be made more precise. If this is a default
2922 -- subprogram, the entity is already established in the generic, and is
2923 -- not retrieved by visibility. If it is a default with a box, the
2924 -- candidate interpretations, if any, have been collected when building
2925 -- the renaming declaration. If overloaded, the proper interpretation is
2926 -- determined in Find_Renamed_Entity. If the entity is an operator,
2927 -- Find_Renamed_Entity applies additional visibility checks.
2930 Inst_Node := Unit_Declaration_Node (Formal_Spec);
2932 -- Check whether the renaming is for a defaulted actual subprogram
2933 -- with a class-wide actual.
2935 -- The class-wide wrapper is not needed in GNATprove_Mode and there
2936 -- is an external axiomatization on the package.
2939 and then Box_Present (Inst_Node)
2943 Present (Containing_Package_With_Ext_Axioms (Formal_Spec)))
2945 Build_Class_Wide_Wrapper (New_S, Old_S);
2947 elsif Is_Entity_Name (Nam)
2948 and then Present (Entity (Nam))
2949 and then not Comes_From_Source (Nam)
2950 and then not Is_Overloaded (Nam)
2952 Old_S := Entity (Nam);
2954 -- The subprogram renaming declaration may become Ghost if it
2955 -- renames a Ghost entity.
2957 Mark_Ghost_Renaming (N, Old_S);
2959 New_S := Analyze_Subprogram_Specification (Spec);
2963 if Ekind (Old_S) = E_Operator then
2967 if Box_Present (Inst_Node) then
2968 Old_S := Find_Renamed_Entity (N, Name (N), New_S, Is_Actual);
2970 -- If there is an immediately visible homonym of the operator
2971 -- and the declaration has a default, this is worth a warning
2972 -- because the user probably did not intend to get the pre-
2973 -- defined operator, visible in the generic declaration. To
2974 -- find if there is an intended candidate, analyze the renaming
2975 -- again in the current context.
2977 elsif Scope (Old_S) = Standard_Standard
2978 and then Present (Default_Name (Inst_Node))
2981 Decl : constant Node_Id := New_Copy_Tree (N);
2985 Set_Entity (Name (Decl), Empty);
2986 Analyze (Name (Decl));
2988 Find_Renamed_Entity (Decl, Name (Decl), New_S, True);
2991 and then In_Open_Scopes (Scope (Hidden))
2992 and then Is_Immediately_Visible (Hidden)
2993 and then Comes_From_Source (Hidden)
2994 and then Hidden /= Old_S
2996 Error_Msg_Sloc := Sloc (Hidden);
2998 ("default subprogram is resolved in the generic "
2999 & "declaration (RM 12.6(17))??", N);
3000 Error_Msg_NE ("\and will not use & #??", N, Hidden);
3009 -- The subprogram renaming declaration may become Ghost if it
3010 -- renames a Ghost entity.
3012 if Is_Entity_Name (Nam) then
3013 Mark_Ghost_Renaming (N, Entity (Nam));
3016 New_S := Analyze_Subprogram_Specification (Spec);
3020 -- Renamed entity must be analyzed first, to avoid being hidden by
3021 -- new name (which might be the same in a generic instance).
3025 -- The subprogram renaming declaration may become Ghost if it renames
3028 if Is_Entity_Name (Nam) then
3029 Mark_Ghost_Renaming (N, Entity (Nam));
3032 -- The renaming defines a new overloaded entity, which is analyzed
3033 -- like a subprogram declaration.
3035 New_S := Analyze_Subprogram_Specification (Spec);
3038 if Current_Scope /= Standard_Standard then
3039 Set_Is_Pure (New_S, Is_Pure (Current_Scope));
3042 -- Set SPARK mode from current context
3044 Set_SPARK_Pragma (New_S, SPARK_Mode_Pragma);
3045 Set_SPARK_Pragma_Inherited (New_S);
3047 Rename_Spec := Find_Corresponding_Spec (N);
3049 -- Case of Renaming_As_Body
3051 if Present (Rename_Spec) then
3052 Check_Previous_Null_Procedure (N, Rename_Spec);
3054 -- Renaming declaration is the completion of the declaration of
3055 -- Rename_Spec. We build an actual body for it at the freezing point.
3057 Set_Corresponding_Spec (N, Rename_Spec);
3059 -- Deal with special case of stream functions of abstract types
3062 if Nkind (Unit_Declaration_Node (Rename_Spec)) =
3063 N_Abstract_Subprogram_Declaration
3065 -- Input stream functions are abstract if the object type is
3066 -- abstract. Similarly, all default stream functions for an
3067 -- interface type are abstract. However, these subprograms may
3068 -- receive explicit declarations in representation clauses, making
3069 -- the attribute subprograms usable as defaults in subsequent
3071 -- In this case we rewrite the declaration to make the subprogram
3072 -- non-abstract. We remove the previous declaration, and insert
3073 -- the new one at the point of the renaming, to prevent premature
3074 -- access to unfrozen types. The new declaration reuses the
3075 -- specification of the previous one, and must not be analyzed.
3078 (Is_Primitive (Entity (Nam))
3080 Is_Abstract_Type (Find_Dispatching_Type (Entity (Nam))));
3082 Old_Decl : constant Node_Id :=
3083 Unit_Declaration_Node (Rename_Spec);
3084 New_Decl : constant Node_Id :=
3085 Make_Subprogram_Declaration (Sloc (N),
3087 Relocate_Node (Specification (Old_Decl)));
3090 Insert_After (N, New_Decl);
3091 Set_Is_Abstract_Subprogram (Rename_Spec, False);
3092 Set_Analyzed (New_Decl);
3096 Set_Corresponding_Body (Unit_Declaration_Node (Rename_Spec), New_S);
3098 if Ada_Version = Ada_83 and then Comes_From_Source (N) then
3099 Error_Msg_N ("(Ada 83) renaming cannot serve as a body", N);
3102 Set_Convention (New_S, Convention (Rename_Spec));
3103 Check_Fully_Conformant (New_S, Rename_Spec);
3104 Set_Public_Status (New_S);
3106 if No_Return (Rename_Spec)
3107 and then not No_Return (Entity (Nam))
3110 ("renamed subprogram & must be No_Return", N, Entity (Nam));
3112 ("\since renaming subprogram is No_Return (RM 6.5.1(7/2))", N);
3115 -- The specification does not introduce new formals, but only
3116 -- repeats the formals of the original subprogram declaration.
3117 -- For cross-reference purposes, and for refactoring tools, we
3118 -- treat the formals of the renaming declaration as body formals.
3120 Reference_Body_Formals (Rename_Spec, New_S);
3122 -- Indicate that the entity in the declaration functions like the
3123 -- corresponding body, and is not a new entity. The body will be
3124 -- constructed later at the freeze point, so indicate that the
3125 -- completion has not been seen yet.
3127 Set_Ekind (New_S, E_Subprogram_Body);
3128 New_S := Rename_Spec;
3129 Set_Has_Completion (Rename_Spec, False);
3131 -- Ada 2005: check overriding indicator
3133 if Present (Overridden_Operation (Rename_Spec)) then
3134 if Must_Not_Override (Specification (N)) then
3136 ("subprogram& overrides inherited operation",
3140 and then not Must_Override (Specification (N))
3142 Style.Missing_Overriding (N, Rename_Spec);
3145 elsif Must_Override (Specification (N)) then
3146 Error_Msg_NE ("subprogram& is not overriding", N, Rename_Spec);
3149 -- Normal subprogram renaming (not renaming as body)
3152 Generate_Definition (New_S);
3153 New_Overloaded_Entity (New_S);
3155 if not (Is_Entity_Name (Nam)
3156 and then Is_Intrinsic_Subprogram (Entity (Nam)))
3158 Check_Delayed_Subprogram (New_S);
3161 -- Verify that a SPARK renaming does not declare a primitive
3162 -- operation of a tagged type.
3164 Check_SPARK_Primitive_Operation (New_S);
3167 -- There is no need for elaboration checks on the new entity, which may
3168 -- be called before the next freezing point where the body will appear.
3169 -- Elaboration checks refer to the real entity, not the one created by
3170 -- the renaming declaration.
3172 Set_Kill_Elaboration_Checks (New_S, True);
3174 -- If we had a previous error, indicate a completely is present to stop
3175 -- junk cascaded messages, but don't take any further action.
3177 if Etype (Nam) = Any_Type then
3178 Set_Has_Completion (New_S);
3181 -- Case where name has the form of a selected component
3183 elsif Nkind (Nam) = N_Selected_Component then
3185 -- A name which has the form A.B can designate an entry of task A, a
3186 -- protected operation of protected object A, or finally a primitive
3187 -- operation of object A. In the later case, A is an object of some
3188 -- tagged type, or an access type that denotes one such. To further
3189 -- distinguish these cases, note that the scope of a task entry or
3190 -- protected operation is type of the prefix.
3192 -- The prefix could be an overloaded function call that returns both
3193 -- kinds of operations. This overloading pathology is left to the
3194 -- dedicated reader ???
3197 T : constant Entity_Id := Etype (Prefix (Nam));
3205 and then Is_Tagged_Type (Designated_Type (T))))
3206 and then Scope (Entity (Selector_Name (Nam))) /= T
3208 Analyze_Renamed_Primitive_Operation
3209 (N, New_S, Present (Rename_Spec));
3213 -- Renamed entity is an entry or protected operation. For those
3214 -- cases an explicit body is built (at the point of freezing of
3215 -- this entity) that contains a call to the renamed entity.
3217 -- This is not allowed for renaming as body if the renamed
3218 -- spec is already frozen (see RM 8.5.4(5) for details).
3220 if Present (Rename_Spec) and then Is_Frozen (Rename_Spec) then
3222 ("renaming-as-body cannot rename entry as subprogram", N);
3224 ("\since & is already frozen (RM 8.5.4(5))",
3227 Analyze_Renamed_Entry (N, New_S, Present (Rename_Spec));
3234 -- Case where name is an explicit dereference X.all
3236 elsif Nkind (Nam) = N_Explicit_Dereference then
3238 -- Renamed entity is designated by access_to_subprogram expression.
3239 -- Must build body to encapsulate call, as in the entry case.
3241 Analyze_Renamed_Dereference (N, New_S, Present (Rename_Spec));
3244 -- Indexed component
3246 elsif Nkind (Nam) = N_Indexed_Component then
3247 Analyze_Renamed_Family_Member (N, New_S, Present (Rename_Spec));
3250 -- Character literal
3252 elsif Nkind (Nam) = N_Character_Literal then
3253 Analyze_Renamed_Character (N, New_S, Present (Rename_Spec));
3256 -- Only remaining case is where we have a non-entity name, or a renaming
3257 -- of some other non-overloadable entity.
3259 elsif not Is_Entity_Name (Nam)
3260 or else not Is_Overloadable (Entity (Nam))
3262 -- Do not mention the renaming if it comes from an instance
3264 if not Is_Actual then
3265 Error_Msg_N ("expect valid subprogram name in renaming", N);
3267 Error_Msg_NE ("no visible subprogram for formal&", N, Nam);
3273 -- Find the renamed entity that matches the given specification. Disable
3274 -- Ada_83 because there is no requirement of full conformance between
3275 -- renamed entity and new entity, even though the same circuit is used.
3277 -- This is a bit of an odd case, which introduces a really irregular use
3278 -- of Ada_Version[_Explicit]. Would be nice to find cleaner way to do
3281 Ada_Version := Ada_Version_Type'Max (Ada_Version, Ada_95);
3282 Ada_Version_Pragma := Empty;
3283 Ada_Version_Explicit := Ada_Version;
3286 Old_S := Find_Renamed_Entity (N, Name (N), New_S, Is_Actual);
3288 -- The visible operation may be an inherited abstract operation that
3289 -- was overridden in the private part, in which case a call will
3290 -- dispatch to the overriding operation. Use the overriding one in
3291 -- the renaming declaration, to prevent spurious errors below.
3293 if Is_Overloadable (Old_S)
3294 and then Is_Abstract_Subprogram (Old_S)
3295 and then No (DTC_Entity (Old_S))
3296 and then Present (Alias (Old_S))
3297 and then not Is_Abstract_Subprogram (Alias (Old_S))
3298 and then Present (Overridden_Operation (Alias (Old_S)))
3300 Old_S := Alias (Old_S);
3303 -- When the renamed subprogram is overloaded and used as an actual
3304 -- of a generic, its entity is set to the first available homonym.
3305 -- We must first disambiguate the name, then set the proper entity.
3307 if Is_Actual and then Is_Overloaded (Nam) then
3308 Set_Entity (Nam, Old_S);
3312 -- Most common case: subprogram renames subprogram. No body is generated
3313 -- in this case, so we must indicate the declaration is complete as is.
3314 -- and inherit various attributes of the renamed subprogram.
3316 if No (Rename_Spec) then
3317 Set_Has_Completion (New_S);
3318 Set_Is_Imported (New_S, Is_Imported (Entity (Nam)));
3319 Set_Is_Pure (New_S, Is_Pure (Entity (Nam)));
3320 Set_Is_Preelaborated (New_S, Is_Preelaborated (Entity (Nam)));
3322 -- Ada 2005 (AI-423): Check the consistency of null exclusions
3323 -- between a subprogram and its correct renaming.
3325 -- Note: the Any_Id check is a guard that prevents compiler crashes
3326 -- when performing a null exclusion check between a renaming and a
3327 -- renamed subprogram that has been found to be illegal.
3329 if Ada_Version >= Ada_2005 and then Entity (Nam) /= Any_Id then
3330 Check_Null_Exclusion
3332 Sub => Entity (Nam));
3335 -- Enforce the Ada 2005 rule that the renamed entity cannot require
3336 -- overriding. The flag Requires_Overriding is set very selectively
3337 -- and misses some other illegal cases. The additional conditions
3338 -- checked below are sufficient but not necessary ???
3340 -- The rule does not apply to the renaming generated for an actual
3341 -- subprogram in an instance.
3346 -- Guard against previous errors, and omit renamings of predefined
3349 elsif not Ekind_In (Old_S, E_Function, E_Procedure) then
3352 elsif Requires_Overriding (Old_S)
3354 (Is_Abstract_Subprogram (Old_S)
3355 and then Present (Find_Dispatching_Type (Old_S))
3356 and then not Is_Abstract_Type (Find_Dispatching_Type (Old_S)))
3359 ("renamed entity cannot be subprogram that requires overriding "
3360 & "(RM 8.5.4 (5.1))", N);
3364 Prev : constant Entity_Id := Overridden_Operation (New_S);
3368 (Has_Non_Trivial_Precondition (Prev)
3369 or else Has_Non_Trivial_Precondition (Old_S))
3372 ("conflicting inherited classwide preconditions in renaming "
3373 & "of& (RM 6.1.1 (17)", N, Old_S);
3378 if Old_S /= Any_Id then
3379 if Is_Actual and then From_Default (N) then
3381 -- This is an implicit reference to the default actual
3383 Generate_Reference (Old_S, Nam, Typ => 'i', Force => True);
3386 Generate_Reference (Old_S, Nam);
3389 Check_Internal_Protected_Use (N, Old_S);
3391 -- For a renaming-as-body, require subtype conformance, but if the
3392 -- declaration being completed has not been frozen, then inherit the
3393 -- convention of the renamed subprogram prior to checking conformance
3394 -- (unless the renaming has an explicit convention established; the
3395 -- rule stated in the RM doesn't seem to address this ???).
3397 if Present (Rename_Spec) then
3398 Generate_Reference (Rename_Spec, Defining_Entity (Spec), 'b');
3399 Style.Check_Identifier (Defining_Entity (Spec), Rename_Spec);
3401 if not Is_Frozen (Rename_Spec) then
3402 if not Has_Convention_Pragma (Rename_Spec) then
3403 Set_Convention (New_S, Convention (Old_S));
3406 if Ekind (Old_S) /= E_Operator then
3407 Check_Mode_Conformant (New_S, Old_S, Spec);
3410 if Original_Subprogram (Old_S) = Rename_Spec then
3411 Error_Msg_N ("unfrozen subprogram cannot rename itself ", N);
3414 Check_Subtype_Conformant (New_S, Old_S, Spec);
3417 Check_Frozen_Renaming (N, Rename_Spec);
3419 -- Check explicitly that renamed entity is not intrinsic, because
3420 -- in a generic the renamed body is not built. In this case,
3421 -- the renaming_as_body is a completion.
3423 if Inside_A_Generic then
3424 if Is_Frozen (Rename_Spec)
3425 and then Is_Intrinsic_Subprogram (Old_S)
3428 ("subprogram in renaming_as_body cannot be intrinsic",
3432 Set_Has_Completion (Rename_Spec);
3435 elsif Ekind (Old_S) /= E_Operator then
3437 -- If this a defaulted subprogram for a class-wide actual there is
3438 -- no check for mode conformance, given that the signatures don't
3439 -- match (the source mentions T but the actual mentions T'Class).
3444 -- No need for a redundant error message if this is a nested
3445 -- instance, unless the current instantiation (of a child unit)
3446 -- is a compilation unit, which is not analyzed when the parent
3447 -- generic is analyzed.
3450 or else No (Enclosing_Instance)
3451 or else Is_Compilation_Unit (Current_Scope)
3453 Check_Mode_Conformant (New_S, Old_S);
3456 if Is_Actual and then Error_Posted (New_S) then
3457 Error_Msg_NE ("invalid actual subprogram: & #!", N, Old_S);
3461 if No (Rename_Spec) then
3463 -- The parameter profile of the new entity is that of the renamed
3464 -- entity: the subtypes given in the specification are irrelevant.
3466 Inherit_Renamed_Profile (New_S, Old_S);
3468 -- A call to the subprogram is transformed into a call to the
3469 -- renamed entity. This is transitive if the renamed entity is
3470 -- itself a renaming.
3472 if Present (Alias (Old_S)) then
3473 Set_Alias (New_S, Alias (Old_S));
3475 Set_Alias (New_S, Old_S);
3478 -- Note that we do not set Is_Intrinsic_Subprogram if we have a
3479 -- renaming as body, since the entity in this case is not an
3480 -- intrinsic (it calls an intrinsic, but we have a real body for
3481 -- this call, and it is in this body that the required intrinsic
3482 -- processing will take place).
3484 -- Also, if this is a renaming of inequality, the renamed operator
3485 -- is intrinsic, but what matters is the corresponding equality
3486 -- operator, which may be user-defined.
3488 Set_Is_Intrinsic_Subprogram
3490 Is_Intrinsic_Subprogram (Old_S)
3492 (Chars (Old_S) /= Name_Op_Ne
3493 or else Ekind (Old_S) = E_Operator
3494 or else Is_Intrinsic_Subprogram
3495 (Corresponding_Equality (Old_S))));
3497 if Ekind (Alias (New_S)) = E_Operator then
3498 Set_Has_Delayed_Freeze (New_S, False);
3501 -- If the renaming corresponds to an association for an abstract
3502 -- formal subprogram, then various attributes must be set to
3503 -- indicate that the renaming is an abstract dispatching operation
3504 -- with a controlling type.
3506 if Is_Actual and then Is_Abstract_Subprogram (Formal_Spec) then
3508 -- Mark the renaming as abstract here, so Find_Dispatching_Type
3509 -- see it as corresponding to a generic association for a
3510 -- formal abstract subprogram
3512 Set_Is_Abstract_Subprogram (New_S);
3515 New_S_Ctrl_Type : constant Entity_Id :=
3516 Find_Dispatching_Type (New_S);
3517 Old_S_Ctrl_Type : constant Entity_Id :=
3518 Find_Dispatching_Type (Old_S);
3522 -- The actual must match the (instance of the) formal,
3523 -- and must be a controlling type.
3525 if Old_S_Ctrl_Type /= New_S_Ctrl_Type
3526 or else No (New_S_Ctrl_Type)
3528 if No (New_S_Ctrl_Type) then
3530 ("actual must be dispatching subprogram", Nam);
3533 ("actual must be dispatching subprogram for type&",
3534 Nam, New_S_Ctrl_Type);
3538 Set_Is_Dispatching_Operation (New_S);
3539 Check_Controlling_Formals (New_S_Ctrl_Type, New_S);
3541 -- If the actual in the formal subprogram is itself a
3542 -- formal abstract subprogram association, there's no
3543 -- dispatch table component or position to inherit.
3545 if Present (DTC_Entity (Old_S)) then
3546 Set_DTC_Entity (New_S, DTC_Entity (Old_S));
3547 Set_DT_Position_Value (New_S, DT_Position (Old_S));
3557 -- The following is illegal, because F hides whatever other F may
3559 -- function F (...) renames F;
3562 or else (Nkind (Nam) /= N_Expanded_Name
3563 and then Chars (Old_S) = Chars (New_S))
3565 Error_Msg_N ("subprogram cannot rename itself", N);
3567 -- This is illegal even if we use a selector:
3568 -- function F (...) renames Pkg.F;
3569 -- because F is still hidden.
3571 elsif Nkind (Nam) = N_Expanded_Name
3572 and then Entity (Prefix (Nam)) = Current_Scope
3573 and then Chars (Selector_Name (Nam)) = Chars (New_S)
3575 -- This is an error, but we overlook the error and accept the
3576 -- renaming if the special Overriding_Renamings mode is in effect.
3578 if not Overriding_Renamings then
3580 ("implicit operation& is not visible (RM 8.3 (15))",
3585 Set_Convention (New_S, Convention (Old_S));
3587 if Is_Abstract_Subprogram (Old_S) then
3588 if Present (Rename_Spec) then
3590 ("a renaming-as-body cannot rename an abstract subprogram",
3592 Set_Has_Completion (Rename_Spec);
3594 Set_Is_Abstract_Subprogram (New_S);
3598 Check_Library_Unit_Renaming (N, Old_S);
3600 -- Pathological case: procedure renames entry in the scope of its
3601 -- task. Entry is given by simple name, but body must be built for
3602 -- procedure. Of course if called it will deadlock.
3604 if Ekind (Old_S) = E_Entry then
3605 Set_Has_Completion (New_S, False);
3606 Set_Alias (New_S, Empty);
3609 -- Do not freeze the renaming nor the renamed entity when the context
3610 -- is an enclosing generic. Freezing is an expansion activity, and in
3611 -- addition the renamed entity may depend on the generic formals of
3612 -- the enclosing generic.
3614 if Is_Actual and not Inside_A_Generic then
3615 Freeze_Before (N, Old_S);
3616 Freeze_Actual_Profile;
3617 Set_Has_Delayed_Freeze (New_S, False);
3618 Freeze_Before (N, New_S);
3620 -- An abstract subprogram is only allowed as an actual in the case
3621 -- where the formal subprogram is also abstract.
3623 if (Ekind (Old_S) = E_Procedure or else Ekind (Old_S) = E_Function)
3624 and then Is_Abstract_Subprogram (Old_S)
3625 and then not Is_Abstract_Subprogram (Formal_Spec)
3628 ("abstract subprogram not allowed as generic actual", Nam);
3633 -- A common error is to assume that implicit operators for types are
3634 -- defined in Standard, or in the scope of a subtype. In those cases
3635 -- where the renamed entity is given with an expanded name, it is
3636 -- worth mentioning that operators for the type are not declared in
3637 -- the scope given by the prefix.
3639 if Nkind (Nam) = N_Expanded_Name
3640 and then Nkind (Selector_Name (Nam)) = N_Operator_Symbol
3641 and then Scope (Entity (Nam)) = Standard_Standard
3644 T : constant Entity_Id :=
3645 Base_Type (Etype (First_Formal (New_S)));
3647 Error_Msg_Node_2 := Prefix (Nam);
3649 ("operator for type& is not declared in&", Prefix (Nam), T);
3654 ("no visible subprogram matches the specification for&",
3658 if Present (Candidate_Renaming) then
3665 F1 := First_Formal (Candidate_Renaming);
3666 F2 := First_Formal (New_S);
3667 T1 := First_Subtype (Etype (F1));
3668 while Present (F1) and then Present (F2) loop
3673 if Present (F1) and then Present (Default_Value (F1)) then
3674 if Present (Next_Formal (F1)) then
3676 ("\missing specification for & and other formals with "
3677 & "defaults", Spec, F1);
3679 Error_Msg_NE ("\missing specification for &", Spec, F1);
3683 if Nkind (Nam) = N_Operator_Symbol
3684 and then From_Default (N)
3686 Error_Msg_Node_2 := T1;
3688 ("default & on & is not directly visible", Nam, Nam);
3694 -- Ada 2005 AI 404: if the new subprogram is dispatching, verify that
3695 -- controlling access parameters are known non-null for the renamed
3696 -- subprogram. Test also applies to a subprogram instantiation that
3697 -- is dispatching. Test is skipped if some previous error was detected
3698 -- that set Old_S to Any_Id.
3700 if Ada_Version >= Ada_2005
3701 and then Old_S /= Any_Id
3702 and then not Is_Dispatching_Operation (Old_S)
3703 and then Is_Dispatching_Operation (New_S)
3710 Old_F := First_Formal (Old_S);
3711 New_F := First_Formal (New_S);
3712 while Present (Old_F) loop
3713 if Ekind (Etype (Old_F)) = E_Anonymous_Access_Type
3714 and then Is_Controlling_Formal (New_F)
3715 and then not Can_Never_Be_Null (Old_F)
3717 Error_Msg_N ("access parameter is controlling,", New_F);
3719 ("\corresponding parameter of& must be explicitly null "
3720 & "excluding", New_F, Old_S);
3723 Next_Formal (Old_F);
3724 Next_Formal (New_F);
3729 -- A useful warning, suggested by Ada Bug Finder (Ada-Europe 2005)
3730 -- is to warn if an operator is being renamed as a different operator.
3731 -- If the operator is predefined, examine the kind of the entity, not
3732 -- the abbreviated declaration in Standard.
3734 if Comes_From_Source (N)
3735 and then Present (Old_S)
3736 and then (Nkind (Old_S) = N_Defining_Operator_Symbol
3737 or else Ekind (Old_S) = E_Operator)
3738 and then Nkind (New_S) = N_Defining_Operator_Symbol
3739 and then Chars (Old_S) /= Chars (New_S)
3742 ("& is being renamed as a different operator??", N, Old_S);
3745 -- Check for renaming of obsolescent subprogram
3747 Check_Obsolescent_2005_Entity (Entity (Nam), Nam);
3749 -- Another warning or some utility: if the new subprogram as the same
3750 -- name as the old one, the old one is not hidden by an outer homograph,
3751 -- the new one is not a public symbol, and the old one is otherwise
3752 -- directly visible, the renaming is superfluous.
3754 if Chars (Old_S) = Chars (New_S)
3755 and then Comes_From_Source (N)
3756 and then Scope (Old_S) /= Standard_Standard
3757 and then Warn_On_Redundant_Constructs
3758 and then (Is_Immediately_Visible (Old_S)
3759 or else Is_Potentially_Use_Visible (Old_S))
3760 and then Is_Overloadable (Current_Scope)
3761 and then Chars (Current_Scope) /= Chars (Old_S)
3764 ("redundant renaming, entity is directly visible?r?", Name (N));
3767 -- Implementation-defined aspect specifications can appear in a renaming
3768 -- declaration, but not language-defined ones. The call to procedure
3769 -- Analyze_Aspect_Specifications will take care of this error check.
3771 if Has_Aspects (N) then
3772 Analyze_Aspect_Specifications (N, New_S);
3775 Ada_Version := Save_AV;
3776 Ada_Version_Pragma := Save_AVP;
3777 Ada_Version_Explicit := Save_AV_Exp;
3779 -- In GNATprove mode, the renamings of actual subprograms are replaced
3780 -- with wrapper functions that make it easier to propagate axioms to the
3781 -- points of call within an instance. Wrappers are generated if formal
3782 -- subprogram is subject to axiomatization.
3784 -- The types in the wrapper profiles are obtained from (instances of)
3785 -- the types of the formal subprogram.
3788 and then GNATprove_Mode
3789 and then Present (Containing_Package_With_Ext_Axioms (Formal_Spec))
3790 and then not Inside_A_Generic
3792 if Ekind (Old_S) = E_Function then
3793 Rewrite (N, Build_Function_Wrapper (Formal_Spec, Old_S));
3796 elsif Ekind (Old_S) = E_Operator then
3797 Rewrite (N, Build_Operator_Wrapper (Formal_Spec, Old_S));
3802 -- Check if we are looking at an Ada 2012 defaulted formal subprogram
3803 -- and mark any use_package_clauses that affect the visibility of the
3804 -- implicit generic actual.
3806 -- Also, we may be looking at an internal renaming of a user-defined
3807 -- subprogram created for a generic formal subprogram association,
3808 -- which will also have to be marked here. This can occur when the
3809 -- corresponding formal subprogram contains references to other generic
3812 if Is_Generic_Actual_Subprogram (New_S)
3813 and then (Is_Intrinsic_Subprogram (New_S)
3814 or else From_Default (N)
3815 or else Nkind (N) = N_Subprogram_Renaming_Declaration)
3817 Mark_Use_Clauses (New_S);
3819 -- Handle overloaded subprograms
3821 if Present (Alias (New_S)) then
3822 Mark_Use_Clauses (Alias (New_S));
3825 end Analyze_Subprogram_Renaming;
3827 -------------------------
3828 -- Analyze_Use_Package --
3829 -------------------------
3831 -- Resolve the package names in the use clause, and make all the visible
3832 -- entities defined in the package potentially use-visible. If the package
3833 -- is already in use from a previous use clause, its visible entities are
3834 -- already use-visible. In that case, mark the occurrence as a redundant
3835 -- use. If the package is an open scope, i.e. if the use clause occurs
3836 -- within the package itself, ignore it.
3838 procedure Analyze_Use_Package (N : Node_Id; Chain : Boolean := True) is
3839 procedure Analyze_Package_Name (Clause : Node_Id);
3840 -- Perform analysis on a package name from a use_package_clause
3842 procedure Analyze_Package_Name_List (Head_Clause : Node_Id);
3843 -- Similar to Analyze_Package_Name but iterates over all the names
3846 --------------------------
3847 -- Analyze_Package_Name --
3848 --------------------------
3850 procedure Analyze_Package_Name (Clause : Node_Id) is
3851 Pack : constant Node_Id := Name (Clause);
3855 pragma Assert (Nkind (Clause) = N_Use_Package_Clause);
3858 -- Verify that the package standard is not directly named in a
3859 -- use_package_clause.
3861 if Nkind (Parent (Clause)) = N_Compilation_Unit
3862 and then Nkind (Pack) = N_Expanded_Name
3864 Pref := Prefix (Pack);
3866 while Nkind (Pref) = N_Expanded_Name loop
3867 Pref := Prefix (Pref);
3870 if Entity (Pref) = Standard_Standard then
3872 ("predefined package Standard cannot appear in a context "
3876 end Analyze_Package_Name;
3878 -------------------------------
3879 -- Analyze_Package_Name_List --
3880 -------------------------------
3882 procedure Analyze_Package_Name_List (Head_Clause : Node_Id) is
3886 -- Due to the way source use clauses are split during parsing we are
3887 -- forced to simply iterate through all entities in scope until the
3888 -- clause representing the last name in the list is found.
3890 Curr := Head_Clause;
3891 while Present (Curr) loop
3892 Analyze_Package_Name (Curr);
3894 -- Stop iterating over the names in the use clause when we are at
3897 exit when not More_Ids (Curr) and then Prev_Ids (Curr);
3900 end Analyze_Package_Name_List;
3906 -- Start of processing for Analyze_Use_Package
3909 Set_Hidden_By_Use_Clause (N, No_Elist);
3911 -- Use clause not allowed in a spec of a predefined package declaration
3912 -- except that packages whose file name starts a-n are OK (these are
3913 -- children of Ada.Numerics, which are never loaded by Rtsfind).
3915 if Is_Predefined_Unit (Current_Sem_Unit)
3916 and then Get_Name_String
3917 (Unit_File_Name (Current_Sem_Unit)) (1 .. 3) /= "a-n"
3918 and then Nkind (Unit (Cunit (Current_Sem_Unit))) =
3919 N_Package_Declaration
3921 Error_Msg_N ("use clause not allowed in predefined spec", N);
3924 -- Loop through all package names from the original use clause in
3925 -- order to analyze referenced packages. A use_package_clause with only
3926 -- one name does not have More_Ids or Prev_Ids set, while a clause with
3927 -- More_Ids only starts the chain produced by the parser.
3929 if not More_Ids (N) and then not Prev_Ids (N) then
3930 Analyze_Package_Name (N);
3932 elsif More_Ids (N) and then not Prev_Ids (N) then
3933 Analyze_Package_Name_List (N);
3936 if not Is_Entity_Name (Name (N)) then
3937 Error_Msg_N ("& is not a package", Name (N));
3943 Chain_Use_Clause (N);
3946 Pack := Entity (Name (N));
3948 -- There are many cases where scopes are manipulated during analysis, so
3949 -- check that Pack's current use clause has not already been chained
3950 -- before setting its previous use clause.
3952 if Ekind (Pack) = E_Package
3953 and then Present (Current_Use_Clause (Pack))
3954 and then Current_Use_Clause (Pack) /= N
3955 and then No (Prev_Use_Clause (N))
3956 and then Prev_Use_Clause (Current_Use_Clause (Pack)) /= N
3958 Set_Prev_Use_Clause (N, Current_Use_Clause (Pack));
3961 -- Mark all entities as potentially use visible.
3963 if Ekind (Pack) /= E_Package and then Etype (Pack) /= Any_Type then
3964 if Ekind (Pack) = E_Generic_Package then
3965 Error_Msg_N -- CODEFIX
3966 ("a generic package is not allowed in a use clause", Name (N));
3968 elsif Ekind_In (Pack, E_Generic_Function, E_Generic_Package)
3970 Error_Msg_N -- CODEFIX
3971 ("a generic subprogram is not allowed in a use clause",
3974 elsif Ekind_In (Pack, E_Function, E_Procedure, E_Operator) then
3975 Error_Msg_N -- CODEFIX
3976 ("a subprogram is not allowed in a use clause", Name (N));
3979 Error_Msg_N ("& is not allowed in a use clause", Name (N));
3983 if Nkind (Parent (N)) = N_Compilation_Unit then
3984 Check_In_Previous_With_Clause (N, Name (N));
3987 Use_One_Package (N, Name (N));
3990 Mark_Ghost_Clause (N);
3991 end Analyze_Use_Package;
3993 ----------------------
3994 -- Analyze_Use_Type --
3995 ----------------------
3997 procedure Analyze_Use_Type (N : Node_Id; Chain : Boolean := True) is
4002 Set_Hidden_By_Use_Clause (N, No_Elist);
4004 -- Chain clause to list of use clauses in current scope when flagged
4007 Chain_Use_Clause (N);
4010 -- Obtain the base type of the type denoted within the use_type_clause's
4013 Id := Subtype_Mark (N);
4015 E := Base_Type (Entity (Id));
4017 -- There are many cases where a use_type_clause may be reanalyzed due to
4018 -- manipulation of the scope stack so we much guard against those cases
4019 -- here, otherwise, we must add the new use_type_clause to the previous
4020 -- use_type_clause chain in order to mark redundant use_type_clauses as
4021 -- used. When the redundant use-type clauses appear in a parent unit and
4022 -- a child unit we must prevent a circularity in the chain that would
4023 -- otherwise result from the separate steps of analysis and installation
4024 -- of the parent context.
4026 if Present (Current_Use_Clause (E))
4027 and then Current_Use_Clause (E) /= N
4028 and then Prev_Use_Clause (Current_Use_Clause (E)) /= N
4029 and then No (Prev_Use_Clause (N))
4031 Set_Prev_Use_Clause (N, Current_Use_Clause (E));
4034 -- If the Used_Operations list is already initialized, the clause has
4035 -- been analyzed previously, and it is being reinstalled, for example
4036 -- when the clause appears in a package spec and we are compiling the
4037 -- corresponding package body. In that case, make the entities on the
4038 -- existing list use_visible, and mark the corresponding types In_Use.
4040 if Present (Used_Operations (N)) then
4045 Use_One_Type (Subtype_Mark (N), Installed => True);
4047 Elmt := First_Elmt (Used_Operations (N));
4048 while Present (Elmt) loop
4049 Set_Is_Potentially_Use_Visible (Node (Elmt));
4057 -- Otherwise, create new list and attach to it the operations that are
4058 -- made use-visible by the clause.
4060 Set_Used_Operations (N, New_Elmt_List);
4063 if E /= Any_Type then
4066 if Nkind (Parent (N)) = N_Compilation_Unit then
4067 if Nkind (Id) = N_Identifier then
4068 Error_Msg_N ("type is not directly visible", Id);
4070 elsif Is_Child_Unit (Scope (E))
4071 and then Scope (E) /= System_Aux_Id
4073 Check_In_Previous_With_Clause (N, Prefix (Id));
4078 -- If the use_type_clause appears in a compilation unit context,
4079 -- check whether it comes from a unit that may appear in a
4080 -- limited_with_clause, for a better error message.
4082 if Nkind (Parent (N)) = N_Compilation_Unit
4083 and then Nkind (Id) /= N_Identifier
4089 function Mentioned (Nam : Node_Id) return Boolean;
4090 -- Check whether the prefix of expanded name for the type
4091 -- appears in the prefix of some limited_with_clause.
4097 function Mentioned (Nam : Node_Id) return Boolean is
4099 return Nkind (Name (Item)) = N_Selected_Component
4100 and then Chars (Prefix (Name (Item))) = Chars (Nam);
4104 Pref := Prefix (Id);
4105 Item := First (Context_Items (Parent (N)));
4106 while Present (Item) and then Item /= N loop
4107 if Nkind (Item) = N_With_Clause
4108 and then Limited_Present (Item)
4109 and then Mentioned (Pref)
4112 (Get_Msg_Id, "premature usage of incomplete type");
4121 Mark_Ghost_Clause (N);
4122 end Analyze_Use_Type;
4124 ------------------------
4125 -- Attribute_Renaming --
4126 ------------------------
4128 procedure Attribute_Renaming (N : Node_Id) is
4129 Loc : constant Source_Ptr := Sloc (N);
4130 Nam : constant Node_Id := Name (N);
4131 Spec : constant Node_Id := Specification (N);
4132 New_S : constant Entity_Id := Defining_Unit_Name (Spec);
4133 Aname : constant Name_Id := Attribute_Name (Nam);
4135 Form_Num : Nat := 0;
4136 Expr_List : List_Id := No_List;
4138 Attr_Node : Node_Id;
4139 Body_Node : Node_Id;
4140 Param_Spec : Node_Id;
4143 Generate_Definition (New_S);
4145 -- This procedure is called in the context of subprogram renaming, and
4146 -- thus the attribute must be one that is a subprogram. All of those
4147 -- have at least one formal parameter, with the exceptions of the GNAT
4148 -- attribute 'Img, which GNAT treats as renameable.
4150 if not Is_Non_Empty_List (Parameter_Specifications (Spec)) then
4151 if Aname /= Name_Img then
4153 ("subprogram renaming an attribute must have formals", N);
4158 Param_Spec := First (Parameter_Specifications (Spec));
4159 while Present (Param_Spec) loop
4160 Form_Num := Form_Num + 1;
4162 if Nkind (Parameter_Type (Param_Spec)) /= N_Access_Definition then
4163 Find_Type (Parameter_Type (Param_Spec));
4165 -- The profile of the new entity denotes the base type (s) of
4166 -- the types given in the specification. For access parameters
4167 -- there are no subtypes involved.
4169 Rewrite (Parameter_Type (Param_Spec),
4171 (Base_Type (Entity (Parameter_Type (Param_Spec))), Loc));
4174 if No (Expr_List) then
4175 Expr_List := New_List;
4178 Append_To (Expr_List,
4179 Make_Identifier (Loc,
4180 Chars => Chars (Defining_Identifier (Param_Spec))));
4182 -- The expressions in the attribute reference are not freeze
4183 -- points. Neither is the attribute as a whole, see below.
4185 Set_Must_Not_Freeze (Last (Expr_List));
4190 -- Immediate error if too many formals. Other mismatches in number or
4191 -- types of parameters are detected when we analyze the body of the
4192 -- subprogram that we construct.
4194 if Form_Num > 2 then
4195 Error_Msg_N ("too many formals for attribute", N);
4197 -- Error if the attribute reference has expressions that look like
4198 -- formal parameters.
4200 elsif Present (Expressions (Nam)) then
4201 Error_Msg_N ("illegal expressions in attribute reference", Nam);
4204 Nam_In (Aname, Name_Compose, Name_Exponent, Name_Leading_Part,
4205 Name_Pos, Name_Round, Name_Scaling,
4208 if Nkind (N) = N_Subprogram_Renaming_Declaration
4209 and then Present (Corresponding_Formal_Spec (N))
4212 ("generic actual cannot be attribute involving universal type",
4216 ("attribute involving a universal type cannot be renamed",
4221 -- Rewrite attribute node to have a list of expressions corresponding to
4222 -- the subprogram formals. A renaming declaration is not a freeze point,
4223 -- and the analysis of the attribute reference should not freeze the
4224 -- type of the prefix. We use the original node in the renaming so that
4225 -- its source location is preserved, and checks on stream attributes are
4226 -- properly applied.
4228 Attr_Node := Relocate_Node (Nam);
4229 Set_Expressions (Attr_Node, Expr_List);
4231 Set_Must_Not_Freeze (Attr_Node);
4232 Set_Must_Not_Freeze (Prefix (Nam));
4234 -- Case of renaming a function
4236 if Nkind (Spec) = N_Function_Specification then
4237 if Is_Procedure_Attribute_Name (Aname) then
4238 Error_Msg_N ("attribute can only be renamed as procedure", Nam);
4242 Find_Type (Result_Definition (Spec));
4243 Rewrite (Result_Definition (Spec),
4245 (Base_Type (Entity (Result_Definition (Spec))), Loc));
4248 Make_Subprogram_Body (Loc,
4249 Specification => Spec,
4250 Declarations => New_List,
4251 Handled_Statement_Sequence =>
4252 Make_Handled_Sequence_Of_Statements (Loc,
4253 Statements => New_List (
4254 Make_Simple_Return_Statement (Loc,
4255 Expression => Attr_Node))));
4257 -- Case of renaming a procedure
4260 if not Is_Procedure_Attribute_Name (Aname) then
4261 Error_Msg_N ("attribute can only be renamed as function", Nam);
4266 Make_Subprogram_Body (Loc,
4267 Specification => Spec,
4268 Declarations => New_List,
4269 Handled_Statement_Sequence =>
4270 Make_Handled_Sequence_Of_Statements (Loc,
4271 Statements => New_List (Attr_Node)));
4274 -- Signal the ABE mechanism that the generated subprogram body has not
4275 -- ABE ramifications.
4277 Set_Was_Attribute_Reference (Body_Node);
4279 -- In case of tagged types we add the body of the generated function to
4280 -- the freezing actions of the type (because in the general case such
4281 -- type is still not frozen). We exclude from this processing generic
4282 -- formal subprograms found in instantiations.
4284 -- We must exclude restricted run-time libraries because
4285 -- entity AST_Handler is defined in package System.Aux_Dec which is not
4286 -- available in those platforms. Note that we cannot use the function
4287 -- Restricted_Profile (instead of Configurable_Run_Time_Mode) because
4288 -- the ZFP run-time library is not defined as a profile, and we do not
4289 -- want to deal with AST_Handler in ZFP mode.
4291 if not Configurable_Run_Time_Mode
4292 and then not Present (Corresponding_Formal_Spec (N))
4293 and then Etype (Nam) /= RTE (RE_AST_Handler)
4296 P : constant Node_Id := Prefix (Nam);
4299 -- The prefix of 'Img is an object that is evaluated for each call
4300 -- of the function that renames it.
4302 if Aname = Name_Img then
4303 Preanalyze_And_Resolve (P);
4305 -- For all other attribute renamings, the prefix is a subtype
4311 -- If the target type is not yet frozen, add the body to the
4312 -- actions to be elaborated at freeze time.
4314 if Is_Tagged_Type (Etype (P))
4315 and then In_Open_Scopes (Scope (Etype (P)))
4317 Ensure_Freeze_Node (Etype (P));
4318 Append_Freeze_Action (Etype (P), Body_Node);
4320 Rewrite (N, Body_Node);
4322 Set_Etype (New_S, Base_Type (Etype (New_S)));
4326 -- Generic formal subprograms or AST_Handler renaming
4329 Rewrite (N, Body_Node);
4331 Set_Etype (New_S, Base_Type (Etype (New_S)));
4334 if Is_Compilation_Unit (New_S) then
4336 ("a library unit can only rename another library unit", N);
4339 -- We suppress elaboration warnings for the resulting entity, since
4340 -- clearly they are not needed, and more particularly, in the case
4341 -- of a generic formal subprogram, the resulting entity can appear
4342 -- after the instantiation itself, and thus look like a bogus case
4343 -- of access before elaboration.
4345 if Legacy_Elaboration_Checks then
4346 Set_Suppress_Elaboration_Warnings (New_S);
4348 end Attribute_Renaming;
4350 ----------------------
4351 -- Chain_Use_Clause --
4352 ----------------------
4354 procedure Chain_Use_Clause (N : Node_Id) is
4355 Level : Int := Scope_Stack.Last;
4361 if not Is_Compilation_Unit (Current_Scope)
4362 or else not Is_Child_Unit (Current_Scope)
4366 -- Common case for compilation unit
4368 elsif Defining_Entity (Parent (N)) = Current_Scope then
4372 -- If declaration appears in some other scope, it must be in some
4373 -- parent unit when compiling a child.
4375 Pack := Defining_Entity (Parent (N));
4377 if not In_Open_Scopes (Pack) then
4380 -- If the use clause appears in an ancestor and we are in the
4381 -- private part of the immediate parent, the use clauses are
4382 -- already installed.
4384 elsif Pack /= Scope (Current_Scope)
4385 and then In_Private_Part (Scope (Current_Scope))
4390 -- Find entry for parent unit in scope stack
4392 while Scope_Stack.Table (Level).Entity /= Pack loop
4398 Set_Next_Use_Clause (N,
4399 Scope_Stack.Table (Level).First_Use_Clause);
4400 Scope_Stack.Table (Level).First_Use_Clause := N;
4401 end Chain_Use_Clause;
4403 ---------------------------
4404 -- Check_Frozen_Renaming --
4405 ---------------------------
4407 procedure Check_Frozen_Renaming (N : Node_Id; Subp : Entity_Id) is
4412 if Is_Frozen (Subp) and then not Has_Completion (Subp) then
4415 (Parent (Declaration_Node (Subp)), Defining_Entity (N));
4417 if Is_Entity_Name (Name (N)) then
4418 Old_S := Entity (Name (N));
4420 if not Is_Frozen (Old_S)
4421 and then Operating_Mode /= Check_Semantics
4423 Append_Freeze_Action (Old_S, B_Node);
4425 Insert_After (N, B_Node);
4429 if Is_Intrinsic_Subprogram (Old_S)
4430 and then not In_Instance
4431 and then not Relaxed_RM_Semantics
4434 ("subprogram used in renaming_as_body cannot be intrinsic",
4439 Insert_After (N, B_Node);
4443 end Check_Frozen_Renaming;
4445 -------------------------------
4446 -- Set_Entity_Or_Discriminal --
4447 -------------------------------
4449 procedure Set_Entity_Or_Discriminal (N : Node_Id; E : Entity_Id) is
4453 -- If the entity is not a discriminant, or else expansion is disabled,
4454 -- simply set the entity.
4456 if not In_Spec_Expression
4457 or else Ekind (E) /= E_Discriminant
4458 or else Inside_A_Generic
4460 Set_Entity_With_Checks (N, E);
4462 -- The replacement of a discriminant by the corresponding discriminal
4463 -- is not done for a task discriminant that appears in a default
4464 -- expression of an entry parameter. See Exp_Ch2.Expand_Discriminant
4465 -- for details on their handling.
4467 elsif Is_Concurrent_Type (Scope (E)) then
4470 and then not Nkind_In (P, N_Parameter_Specification,
4471 N_Component_Declaration)
4477 and then Nkind (P) = N_Parameter_Specification
4482 Set_Entity (N, Discriminal (E));
4485 -- Otherwise, this is a discriminant in a context in which
4486 -- it is a reference to the corresponding parameter of the
4487 -- init proc for the enclosing type.
4490 Set_Entity (N, Discriminal (E));
4492 end Set_Entity_Or_Discriminal;
4494 -----------------------------------
4495 -- Check_In_Previous_With_Clause --
4496 -----------------------------------
4498 procedure Check_In_Previous_With_Clause
4502 Pack : constant Entity_Id := Entity (Original_Node (Nam));
4507 Item := First (Context_Items (Parent (N)));
4508 while Present (Item) and then Item /= N loop
4509 if Nkind (Item) = N_With_Clause
4511 -- Protect the frontend against previous critical errors
4513 and then Nkind (Name (Item)) /= N_Selected_Component
4514 and then Entity (Name (Item)) = Pack
4518 -- Find root library unit in with_clause
4520 while Nkind (Par) = N_Expanded_Name loop
4521 Par := Prefix (Par);
4524 if Is_Child_Unit (Entity (Original_Node (Par))) then
4525 Error_Msg_NE ("& is not directly visible", Par, Entity (Par));
4534 -- On exit, package is not mentioned in a previous with_clause.
4535 -- Check if its prefix is.
4537 if Nkind (Nam) = N_Expanded_Name then
4538 Check_In_Previous_With_Clause (N, Prefix (Nam));
4540 elsif Pack /= Any_Id then
4541 Error_Msg_NE ("& is not visible", Nam, Pack);
4543 end Check_In_Previous_With_Clause;
4545 ---------------------------------
4546 -- Check_Library_Unit_Renaming --
4547 ---------------------------------
4549 procedure Check_Library_Unit_Renaming (N : Node_Id; Old_E : Entity_Id) is
4553 if Nkind (Parent (N)) /= N_Compilation_Unit then
4556 -- Check for library unit. Note that we used to check for the scope
4557 -- being Standard here, but that was wrong for Standard itself.
4559 elsif not Is_Compilation_Unit (Old_E)
4560 and then not Is_Child_Unit (Old_E)
4562 Error_Msg_N ("renamed unit must be a library unit", Name (N));
4564 -- Entities defined in Standard (operators and boolean literals) cannot
4565 -- be renamed as library units.
4567 elsif Scope (Old_E) = Standard_Standard
4568 and then Sloc (Old_E) = Standard_Location
4570 Error_Msg_N ("renamed unit must be a library unit", Name (N));
4572 elsif Present (Parent_Spec (N))
4573 and then Nkind (Unit (Parent_Spec (N))) = N_Generic_Package_Declaration
4574 and then not Is_Child_Unit (Old_E)
4577 ("renamed unit must be a child unit of generic parent", Name (N));
4579 elsif Nkind (N) in N_Generic_Renaming_Declaration
4580 and then Nkind (Name (N)) = N_Expanded_Name
4581 and then Is_Generic_Instance (Entity (Prefix (Name (N))))
4582 and then Is_Generic_Unit (Old_E)
4585 ("renamed generic unit must be a library unit", Name (N));
4587 elsif Is_Package_Or_Generic_Package (Old_E) then
4589 -- Inherit categorization flags
4591 New_E := Defining_Entity (N);
4592 Set_Is_Pure (New_E, Is_Pure (Old_E));
4593 Set_Is_Preelaborated (New_E, Is_Preelaborated (Old_E));
4594 Set_Is_Remote_Call_Interface (New_E,
4595 Is_Remote_Call_Interface (Old_E));
4596 Set_Is_Remote_Types (New_E, Is_Remote_Types (Old_E));
4597 Set_Is_Shared_Passive (New_E, Is_Shared_Passive (Old_E));
4599 end Check_Library_Unit_Renaming;
4601 ------------------------
4602 -- Enclosing_Instance --
4603 ------------------------
4605 function Enclosing_Instance return Entity_Id is
4609 if not Is_Generic_Instance (Current_Scope) then
4613 S := Scope (Current_Scope);
4614 while S /= Standard_Standard loop
4615 if Is_Generic_Instance (S) then
4623 end Enclosing_Instance;
4629 procedure End_Scope is
4635 Id := First_Entity (Current_Scope);
4636 while Present (Id) loop
4637 -- An entity in the current scope is not necessarily the first one
4638 -- on its homonym chain. Find its predecessor if any,
4639 -- If it is an internal entity, it will not be in the visibility
4640 -- chain altogether, and there is nothing to unchain.
4642 if Id /= Current_Entity (Id) then
4643 Prev := Current_Entity (Id);
4644 while Present (Prev)
4645 and then Present (Homonym (Prev))
4646 and then Homonym (Prev) /= Id
4648 Prev := Homonym (Prev);
4651 -- Skip to end of loop if Id is not in the visibility chain
4653 if No (Prev) or else Homonym (Prev) /= Id then
4661 Set_Is_Immediately_Visible (Id, False);
4663 Outer := Homonym (Id);
4664 while Present (Outer) and then Scope (Outer) = Current_Scope loop
4665 Outer := Homonym (Outer);
4668 -- Reset homonym link of other entities, but do not modify link
4669 -- between entities in current scope, so that the back-end can have
4670 -- a proper count of local overloadings.
4673 Set_Name_Entity_Id (Chars (Id), Outer);
4675 elsif Scope (Prev) /= Scope (Id) then
4676 Set_Homonym (Prev, Outer);
4683 -- If the scope generated freeze actions, place them before the
4684 -- current declaration and analyze them. Type declarations and
4685 -- the bodies of initialization procedures can generate such nodes.
4686 -- We follow the parent chain until we reach a list node, which is
4687 -- the enclosing list of declarations. If the list appears within
4688 -- a protected definition, move freeze nodes outside the protected
4692 (Scope_Stack.Table (Scope_Stack.Last).Pending_Freeze_Actions)
4696 L : constant List_Id := Scope_Stack.Table
4697 (Scope_Stack.Last).Pending_Freeze_Actions;
4700 if Is_Itype (Current_Scope) then
4701 Decl := Associated_Node_For_Itype (Current_Scope);
4703 Decl := Parent (Current_Scope);
4708 while not (Is_List_Member (Decl))
4709 or else Nkind_In (Parent (Decl), N_Protected_Definition,
4712 Decl := Parent (Decl);
4715 Insert_List_Before_And_Analyze (Decl, L);
4723 ---------------------
4724 -- End_Use_Clauses --
4725 ---------------------
4727 procedure End_Use_Clauses (Clause : Node_Id) is
4731 -- Remove use_type_clauses first, because they affect the visibility of
4732 -- operators in subsequent used packages.
4735 while Present (U) loop
4736 if Nkind (U) = N_Use_Type_Clause then
4740 Next_Use_Clause (U);
4744 while Present (U) loop
4745 if Nkind (U) = N_Use_Package_Clause then
4746 End_Use_Package (U);
4749 Next_Use_Clause (U);
4751 end End_Use_Clauses;
4753 ---------------------
4754 -- End_Use_Package --
4755 ---------------------
4757 procedure End_Use_Package (N : Node_Id) is
4759 Pack_Name : Node_Id;
4763 function Is_Primitive_Operator_In_Use
4765 F : Entity_Id) return Boolean;
4766 -- Check whether Op is a primitive operator of a use-visible type
4768 ----------------------------------
4769 -- Is_Primitive_Operator_In_Use --
4770 ----------------------------------
4772 function Is_Primitive_Operator_In_Use
4774 F : Entity_Id) return Boolean
4776 T : constant Entity_Id := Base_Type (Etype (F));
4778 return In_Use (T) and then Scope (T) = Scope (Op);
4779 end Is_Primitive_Operator_In_Use;
4781 -- Start of processing for End_Use_Package
4784 Pack_Name := Name (N);
4786 -- Test that Pack_Name actually denotes a package before processing
4788 if Is_Entity_Name (Pack_Name)
4789 and then Ekind (Entity (Pack_Name)) = E_Package
4791 Pack := Entity (Pack_Name);
4793 if In_Open_Scopes (Pack) then
4796 elsif not Redundant_Use (Pack_Name) then
4797 Set_In_Use (Pack, False);
4798 Set_Current_Use_Clause (Pack, Empty);
4800 Id := First_Entity (Pack);
4801 while Present (Id) loop
4803 -- Preserve use-visibility of operators that are primitive
4804 -- operators of a type that is use-visible through an active
4807 if Nkind (Id) = N_Defining_Operator_Symbol
4809 (Is_Primitive_Operator_In_Use (Id, First_Formal (Id))
4811 (Present (Next_Formal (First_Formal (Id)))
4813 Is_Primitive_Operator_In_Use
4814 (Id, Next_Formal (First_Formal (Id)))))
4818 Set_Is_Potentially_Use_Visible (Id, False);
4821 if Is_Private_Type (Id)
4822 and then Present (Full_View (Id))
4824 Set_Is_Potentially_Use_Visible (Full_View (Id), False);
4830 if Present (Renamed_Object (Pack)) then
4831 Set_In_Use (Renamed_Object (Pack), False);
4832 Set_Current_Use_Clause (Renamed_Object (Pack), Empty);
4835 if Chars (Pack) = Name_System
4836 and then Scope (Pack) = Standard_Standard
4837 and then Present_System_Aux
4839 Id := First_Entity (System_Aux_Id);
4840 while Present (Id) loop
4841 Set_Is_Potentially_Use_Visible (Id, False);
4843 if Is_Private_Type (Id)
4844 and then Present (Full_View (Id))
4846 Set_Is_Potentially_Use_Visible (Full_View (Id), False);
4852 Set_In_Use (System_Aux_Id, False);
4855 Set_Redundant_Use (Pack_Name, False);
4859 if Present (Hidden_By_Use_Clause (N)) then
4860 Elmt := First_Elmt (Hidden_By_Use_Clause (N));
4861 while Present (Elmt) loop
4863 E : constant Entity_Id := Node (Elmt);
4866 -- Reset either Use_Visibility or Direct_Visibility, depending
4867 -- on how the entity was hidden by the use clause.
4869 if In_Use (Scope (E))
4870 and then Used_As_Generic_Actual (Scope (E))
4872 Set_Is_Potentially_Use_Visible (Node (Elmt));
4874 Set_Is_Immediately_Visible (Node (Elmt));
4881 Set_Hidden_By_Use_Clause (N, No_Elist);
4883 end End_Use_Package;
4889 procedure End_Use_Type (N : Node_Id) is
4894 -- Start of processing for End_Use_Type
4897 Id := Subtype_Mark (N);
4899 -- A call to Rtsfind may occur while analyzing a use_type_clause, in
4900 -- which case the type marks are not resolved yet, so guard against that
4903 if Is_Entity_Name (Id) and then Present (Entity (Id)) then
4906 if T = Any_Type or else From_Limited_With (T) then
4909 -- Note that the use_type_clause may mention a subtype of the type
4910 -- whose primitive operations have been made visible. Here as
4911 -- elsewhere, it is the base type that matters for visibility.
4913 elsif In_Open_Scopes (Scope (Base_Type (T))) then
4916 elsif not Redundant_Use (Id) then
4917 Set_In_Use (T, False);
4918 Set_In_Use (Base_Type (T), False);
4919 Set_Current_Use_Clause (T, Empty);
4920 Set_Current_Use_Clause (Base_Type (T), Empty);
4922 -- See Use_One_Type for the rationale. This is a bit on the naive
4923 -- side, but should be good enough in practice.
4925 if Is_Tagged_Type (T) then
4926 Set_In_Use (Class_Wide_Type (T), False);
4931 if Is_Empty_Elmt_List (Used_Operations (N)) then
4935 Elmt := First_Elmt (Used_Operations (N));
4936 while Present (Elmt) loop
4937 Set_Is_Potentially_Use_Visible (Node (Elmt), False);
4943 --------------------
4944 -- Entity_Of_Unit --
4945 --------------------
4947 function Entity_Of_Unit (U : Node_Id) return Entity_Id is
4949 if Nkind (U) = N_Package_Instantiation and then Analyzed (U) then
4950 return Defining_Entity (Instance_Spec (U));
4952 return Defining_Entity (U);
4956 ----------------------
4957 -- Find_Direct_Name --
4958 ----------------------
4960 procedure Find_Direct_Name
4962 Errors_OK : Boolean := True;
4963 Marker_OK : Boolean := True;
4964 Reference_OK : Boolean := True)
4970 Homonyms : Entity_Id;
4971 -- Saves start of homonym chain
4973 Inst : Entity_Id := Empty;
4974 -- Enclosing instance, if any
4976 Nvis_Entity : Boolean;
4977 -- Set True to indicate that there is at least one entity on the homonym
4978 -- chain which, while not visible, is visible enough from the user point
4979 -- of view to warrant an error message of "not visible" rather than
4982 Nvis_Is_Private_Subprg : Boolean := False;
4983 -- Ada 2005 (AI-262): Set True to indicate that a form of Beaujolais
4984 -- effect concerning library subprograms has been detected. Used to
4985 -- generate the precise error message.
4987 function From_Actual_Package (E : Entity_Id) return Boolean;
4988 -- Returns true if the entity is an actual for a package that is itself
4989 -- an actual for a formal package of the current instance. Such an
4990 -- entity requires special handling because it may be use-visible but
4991 -- hides directly visible entities defined outside the instance, because
4992 -- the corresponding formal did so in the generic.
4994 function Is_Actual_Parameter return Boolean;
4995 -- This function checks if the node N is an identifier that is an actual
4996 -- parameter of a procedure call. If so it returns True, otherwise it
4997 -- return False. The reason for this check is that at this stage we do
4998 -- not know what procedure is being called if the procedure might be
4999 -- overloaded, so it is premature to go setting referenced flags or
5000 -- making calls to Generate_Reference. We will wait till Resolve_Actuals
5001 -- for that processing
5003 function Known_But_Invisible (E : Entity_Id) return Boolean;
5004 -- This function determines whether a reference to the entity E, which
5005 -- is not visible, can reasonably be considered to be known to the
5006 -- writer of the reference. This is a heuristic test, used only for
5007 -- the purposes of figuring out whether we prefer to complain that an
5008 -- entity is undefined or invisible (and identify the declaration of
5009 -- the invisible entity in the latter case). The point here is that we
5010 -- don't want to complain that something is invisible and then point to
5011 -- something entirely mysterious to the writer.
5013 procedure Nvis_Messages;
5014 -- Called if there are no visible entries for N, but there is at least
5015 -- one non-directly visible, or hidden declaration. This procedure
5016 -- outputs an appropriate set of error messages.
5018 procedure Undefined (Nvis : Boolean);
5019 -- This function is called if the current node has no corresponding
5020 -- visible entity or entities. The value set in Msg indicates whether
5021 -- an error message was generated (multiple error messages for the
5022 -- same variable are generally suppressed, see body for details).
5023 -- Msg is True if an error message was generated, False if not. This
5024 -- value is used by the caller to determine whether or not to output
5025 -- additional messages where appropriate. The parameter is set False
5026 -- to get the message "X is undefined", and True to get the message
5027 -- "X is not visible".
5029 -------------------------
5030 -- From_Actual_Package --
5031 -------------------------
5033 function From_Actual_Package (E : Entity_Id) return Boolean is
5034 Scop : constant Entity_Id := Scope (E);
5035 -- Declared scope of candidate entity
5037 function Declared_In_Actual (Pack : Entity_Id) return Boolean;
5038 -- Recursive function that does the work and examines actuals of
5039 -- actual packages of current instance.
5041 ------------------------
5042 -- Declared_In_Actual --
5043 ------------------------
5045 function Declared_In_Actual (Pack : Entity_Id) return Boolean is
5049 if No (Associated_Formal_Package (Pack)) then
5053 Act := First_Entity (Pack);
5054 while Present (Act) loop
5055 if Renamed_Object (Pack) = Scop then
5058 -- Check for end of list of actuals
5060 elsif Ekind (Act) = E_Package
5061 and then Renamed_Object (Act) = Pack
5065 elsif Ekind (Act) = E_Package
5066 and then Declared_In_Actual (Act)
5076 end Declared_In_Actual;
5082 -- Start of processing for From_Actual_Package
5085 if not In_Instance then
5089 Inst := Current_Scope;
5090 while Present (Inst)
5091 and then Ekind (Inst) /= E_Package
5092 and then not Is_Generic_Instance (Inst)
5094 Inst := Scope (Inst);
5101 Act := First_Entity (Inst);
5102 while Present (Act) loop
5103 if Ekind (Act) = E_Package
5104 and then Declared_In_Actual (Act)
5114 end From_Actual_Package;
5116 -------------------------
5117 -- Is_Actual_Parameter --
5118 -------------------------
5120 function Is_Actual_Parameter return Boolean is
5123 Nkind (N) = N_Identifier
5125 (Nkind (Parent (N)) = N_Procedure_Call_Statement
5127 (Nkind (Parent (N)) = N_Parameter_Association
5128 and then N = Explicit_Actual_Parameter (Parent (N))
5129 and then Nkind (Parent (Parent (N))) =
5130 N_Procedure_Call_Statement));
5131 end Is_Actual_Parameter;
5133 -------------------------
5134 -- Known_But_Invisible --
5135 -------------------------
5137 function Known_But_Invisible (E : Entity_Id) return Boolean is
5138 Fname : File_Name_Type;
5141 -- Entities in Standard are always considered to be known
5143 if Sloc (E) <= Standard_Location then
5146 -- An entity that does not come from source is always considered
5147 -- to be unknown, since it is an artifact of code expansion.
5149 elsif not Comes_From_Source (E) then
5152 -- In gnat internal mode, we consider all entities known. The
5153 -- historical reason behind this discrepancy is not known??? But the
5154 -- only effect is to modify the error message given, so it is not
5155 -- critical. Since it only affects the exact wording of error
5156 -- messages in illegal programs, we do not mention this as an
5157 -- effect of -gnatg, since it is not a language modification.
5159 elsif GNAT_Mode then
5163 -- Here we have an entity that is not from package Standard, and
5164 -- which comes from Source. See if it comes from an internal file.
5166 Fname := Unit_File_Name (Get_Source_Unit (E));
5168 -- Case of from internal file
5170 if In_Internal_Unit (E) then
5172 -- Private part entities in internal files are never considered
5173 -- to be known to the writer of normal application code.
5175 if Is_Hidden (E) then
5179 -- Entities from System packages other than System and
5180 -- System.Storage_Elements are not considered to be known.
5181 -- System.Auxxxx files are also considered known to the user.
5183 -- Should refine this at some point to generally distinguish
5184 -- between known and unknown internal files ???
5186 Get_Name_String (Fname);
5191 Name_Buffer (1 .. 2) /= "s-"
5193 Name_Buffer (3 .. 8) = "stoele"
5195 Name_Buffer (3 .. 5) = "aux";
5197 -- If not an internal file, then entity is definitely known, even if
5198 -- it is in a private part (the message generated will note that it
5199 -- is in a private part).
5204 end Known_But_Invisible;
5210 procedure Nvis_Messages is
5211 Comp_Unit : Node_Id;
5213 Found : Boolean := False;
5214 Hidden : Boolean := False;
5218 if not Errors_OK then
5222 -- Ada 2005 (AI-262): Generate a precise error concerning the
5223 -- Beaujolais effect that was previously detected
5225 if Nvis_Is_Private_Subprg then
5227 pragma Assert (Nkind (E2) = N_Defining_Identifier
5228 and then Ekind (E2) = E_Function
5229 and then Scope (E2) = Standard_Standard
5230 and then Has_Private_With (E2));
5232 -- Find the sloc corresponding to the private with'ed unit
5234 Comp_Unit := Cunit (Current_Sem_Unit);
5235 Error_Msg_Sloc := No_Location;
5237 Item := First (Context_Items (Comp_Unit));
5238 while Present (Item) loop
5239 if Nkind (Item) = N_With_Clause
5240 and then Private_Present (Item)
5241 and then Entity (Name (Item)) = E2
5243 Error_Msg_Sloc := Sloc (Item);
5250 pragma Assert (Error_Msg_Sloc /= No_Location);
5252 Error_Msg_N ("(Ada 2005): hidden by private with clause #", N);
5256 Undefined (Nvis => True);
5260 -- First loop does hidden declarations
5263 while Present (Ent) loop
5264 if Is_Potentially_Use_Visible (Ent) then
5266 Error_Msg_N -- CODEFIX
5267 ("multiple use clauses cause hiding!", N);
5271 Error_Msg_Sloc := Sloc (Ent);
5272 Error_Msg_N -- CODEFIX
5273 ("hidden declaration#!", N);
5276 Ent := Homonym (Ent);
5279 -- If we found hidden declarations, then that's enough, don't
5280 -- bother looking for non-visible declarations as well.
5286 -- Second loop does non-directly visible declarations
5289 while Present (Ent) loop
5290 if not Is_Potentially_Use_Visible (Ent) then
5292 -- Do not bother the user with unknown entities
5294 if not Known_But_Invisible (Ent) then
5298 Error_Msg_Sloc := Sloc (Ent);
5300 -- Output message noting that there is a non-visible
5301 -- declaration, distinguishing the private part case.
5303 if Is_Hidden (Ent) then
5304 Error_Msg_N ("non-visible (private) declaration#!", N);
5306 -- If the entity is declared in a generic package, it
5307 -- cannot be visible, so there is no point in adding it
5308 -- to the list of candidates if another homograph from a
5309 -- non-generic package has been seen.
5311 elsif Ekind (Scope (Ent)) = E_Generic_Package
5317 Error_Msg_N -- CODEFIX
5318 ("non-visible declaration#!", N);
5320 if Ekind (Scope (Ent)) /= E_Generic_Package then
5324 if Is_Compilation_Unit (Ent)
5326 Nkind (Parent (Parent (N))) = N_Use_Package_Clause
5328 Error_Msg_Qual_Level := 99;
5329 Error_Msg_NE -- CODEFIX
5330 ("\\missing `WITH &;`", N, Ent);
5331 Error_Msg_Qual_Level := 0;
5334 if Ekind (Ent) = E_Discriminant
5335 and then Present (Corresponding_Discriminant (Ent))
5336 and then Scope (Corresponding_Discriminant (Ent)) =
5340 ("inherited discriminant not allowed here" &
5341 " (RM 3.8 (12), 3.8.1 (6))!", N);
5345 -- Set entity and its containing package as referenced. We
5346 -- can't be sure of this, but this seems a better choice
5347 -- to avoid unused entity messages.
5349 if Comes_From_Source (Ent) then
5350 Set_Referenced (Ent);
5351 Set_Referenced (Cunit_Entity (Get_Source_Unit (Ent)));
5356 Ent := Homonym (Ent);
5365 procedure Undefined (Nvis : Boolean) is
5366 Emsg : Error_Msg_Id;
5369 -- We should never find an undefined internal name. If we do, then
5370 -- see if we have previous errors. If so, ignore on the grounds that
5371 -- it is probably a cascaded message (e.g. a block label from a badly
5372 -- formed block). If no previous errors, then we have a real internal
5373 -- error of some kind so raise an exception.
5375 if Is_Internal_Name (Chars (N)) then
5376 if Total_Errors_Detected /= 0 then
5379 raise Program_Error;
5383 -- A very specialized error check, if the undefined variable is
5384 -- a case tag, and the case type is an enumeration type, check
5385 -- for a possible misspelling, and if so, modify the identifier
5387 -- Named aggregate should also be handled similarly ???
5390 and then Nkind (N) = N_Identifier
5391 and then Nkind (Parent (N)) = N_Case_Statement_Alternative
5394 Case_Stm : constant Node_Id := Parent (Parent (N));
5395 Case_Typ : constant Entity_Id := Etype (Expression (Case_Stm));
5400 if Is_Enumeration_Type (Case_Typ)
5401 and then not Is_Standard_Character_Type (Case_Typ)
5403 Lit := First_Literal (Case_Typ);
5404 Get_Name_String (Chars (Lit));
5406 if Chars (Lit) /= Chars (N)
5407 and then Is_Bad_Spelling_Of (Chars (N), Chars (Lit))
5409 Error_Msg_Node_2 := Lit;
5410 Error_Msg_N -- CODEFIX
5411 ("& is undefined, assume misspelling of &", N);
5412 Rewrite (N, New_Occurrence_Of (Lit, Sloc (N)));
5421 -- Normal processing
5423 Set_Entity (N, Any_Id);
5424 Set_Etype (N, Any_Type);
5428 -- We use the table Urefs to keep track of entities for which we
5429 -- have issued errors for undefined references. Multiple errors
5430 -- for a single name are normally suppressed, however we modify
5431 -- the error message to alert the programmer to this effect.
5433 for J in Urefs.First .. Urefs.Last loop
5434 if Chars (N) = Chars (Urefs.Table (J).Node) then
5435 if Urefs.Table (J).Err /= No_Error_Msg
5436 and then Sloc (N) /= Urefs.Table (J).Loc
5438 Error_Msg_Node_1 := Urefs.Table (J).Node;
5440 if Urefs.Table (J).Nvis then
5441 Change_Error_Text (Urefs.Table (J).Err,
5442 "& is not visible (more references follow)");
5444 Change_Error_Text (Urefs.Table (J).Err,
5445 "& is undefined (more references follow)");
5448 Urefs.Table (J).Err := No_Error_Msg;
5451 -- Although we will set Msg False, and thus suppress the
5452 -- message, we also set Error_Posted True, to avoid any
5453 -- cascaded messages resulting from the undefined reference.
5456 Set_Error_Posted (N);
5461 -- If entry not found, this is first undefined occurrence
5464 Error_Msg_N ("& is not visible!", N);
5468 Error_Msg_N ("& is undefined!", N);
5471 -- A very bizarre special check, if the undefined identifier
5472 -- is Put or Put_Line, then add a special error message (since
5473 -- this is a very common error for beginners to make).
5475 if Nam_In (Chars (N), Name_Put, Name_Put_Line) then
5476 Error_Msg_N -- CODEFIX
5477 ("\\possible missing `WITH Ada.Text_'I'O; " &
5478 "USE Ada.Text_'I'O`!", N);
5480 -- Another special check if N is the prefix of a selected
5481 -- component which is a known unit: add message complaining
5482 -- about missing with for this unit.
5484 elsif Nkind (Parent (N)) = N_Selected_Component
5485 and then N = Prefix (Parent (N))
5486 and then Is_Known_Unit (Parent (N))
5488 Error_Msg_Node_2 := Selector_Name (Parent (N));
5489 Error_Msg_N -- CODEFIX
5490 ("\\missing `WITH &.&;`", Prefix (Parent (N)));
5493 -- Now check for possible misspellings
5497 Ematch : Entity_Id := Empty;
5499 Last_Name_Id : constant Name_Id :=
5500 Name_Id (Nat (First_Name_Id) +
5501 Name_Entries_Count - 1);
5504 for Nam in First_Name_Id .. Last_Name_Id loop
5505 E := Get_Name_Entity_Id (Nam);
5508 and then (Is_Immediately_Visible (E)
5510 Is_Potentially_Use_Visible (E))
5512 if Is_Bad_Spelling_Of (Chars (N), Nam) then
5519 if Present (Ematch) then
5520 Error_Msg_NE -- CODEFIX
5521 ("\possible misspelling of&", N, Ematch);
5526 -- Make entry in undefined references table unless the full errors
5527 -- switch is set, in which case by refraining from generating the
5528 -- table entry we guarantee that we get an error message for every
5529 -- undefined reference. The entry is not added if we are ignoring
5532 if not All_Errors_Mode and then Ignore_Errors_Enable = 0 then
5546 Nested_Inst : Entity_Id := Empty;
5547 -- The entity of a nested instance which appears within Inst (if any)
5549 -- Start of processing for Find_Direct_Name
5552 -- If the entity pointer is already set, this is an internal node, or
5553 -- a node that is analyzed more than once, after a tree modification.
5554 -- In such a case there is no resolution to perform, just set the type.
5556 if Present (Entity (N)) then
5557 if Is_Type (Entity (N)) then
5558 Set_Etype (N, Entity (N));
5562 Entyp : constant Entity_Id := Etype (Entity (N));
5565 -- One special case here. If the Etype field is already set,
5566 -- and references the packed array type corresponding to the
5567 -- etype of the referenced entity, then leave it alone. This
5568 -- happens for trees generated from Exp_Pakd, where expressions
5569 -- can be deliberately "mis-typed" to the packed array type.
5571 if Is_Array_Type (Entyp)
5572 and then Is_Packed (Entyp)
5573 and then Present (Etype (N))
5574 and then Etype (N) = Packed_Array_Impl_Type (Entyp)
5578 -- If not that special case, then just reset the Etype
5581 Set_Etype (N, Etype (Entity (N)));
5586 -- Although the marking of use clauses happens at the end of
5587 -- Find_Direct_Name, a certain case where a generic actual satisfies
5588 -- a use clause must be checked here due to how the generic machinery
5589 -- handles the analysis of said actuals.
5592 and then Nkind (Parent (N)) = N_Generic_Association
5594 Mark_Use_Clauses (Entity (N));
5600 -- Preserve relevant elaboration-related attributes of the context which
5601 -- are no longer available or very expensive to recompute once analysis,
5602 -- resolution, and expansion are over.
5604 if Nkind (N) = N_Identifier then
5605 Mark_Elaboration_Attributes
5612 -- Here if Entity pointer was not set, we need full visibility analysis
5613 -- First we generate debugging output if the debug E flag is set.
5615 if Debug_Flag_E then
5616 Write_Str ("Looking for ");
5617 Write_Name (Chars (N));
5621 Homonyms := Current_Entity (N);
5622 Nvis_Entity := False;
5625 while Present (E) loop
5627 -- If entity is immediately visible or potentially use visible, then
5628 -- process the entity and we are done.
5630 if Is_Immediately_Visible (E) then
5631 goto Immediately_Visible_Entity;
5633 elsif Is_Potentially_Use_Visible (E) then
5634 goto Potentially_Use_Visible_Entity;
5636 -- Note if a known but invisible entity encountered
5638 elsif Known_But_Invisible (E) then
5639 Nvis_Entity := True;
5642 -- Move to next entity in chain and continue search
5647 -- If no entries on homonym chain that were potentially visible,
5648 -- and no entities reasonably considered as non-visible, then
5649 -- we have a plain undefined reference, with no additional
5650 -- explanation required.
5652 if not Nvis_Entity then
5653 Undefined (Nvis => False);
5655 -- Otherwise there is at least one entry on the homonym chain that
5656 -- is reasonably considered as being known and non-visible.
5664 -- Processing for a potentially use visible entry found. We must search
5665 -- the rest of the homonym chain for two reasons. First, if there is a
5666 -- directly visible entry, then none of the potentially use-visible
5667 -- entities are directly visible (RM 8.4(10)). Second, we need to check
5668 -- for the case of multiple potentially use-visible entries hiding one
5669 -- another and as a result being non-directly visible (RM 8.4(11)).
5671 <<Potentially_Use_Visible_Entity>> declare
5672 Only_One_Visible : Boolean := True;
5673 All_Overloadable : Boolean := Is_Overloadable (E);
5677 while Present (E2) loop
5678 if Is_Immediately_Visible (E2) then
5680 -- If the use-visible entity comes from the actual for a
5681 -- formal package, it hides a directly visible entity from
5682 -- outside the instance.
5684 if From_Actual_Package (E)
5685 and then Scope_Depth (E2) < Scope_Depth (Inst)
5690 goto Immediately_Visible_Entity;
5693 elsif Is_Potentially_Use_Visible (E2) then
5694 Only_One_Visible := False;
5695 All_Overloadable := All_Overloadable and Is_Overloadable (E2);
5697 -- Ada 2005 (AI-262): Protect against a form of Beaujolais effect
5698 -- that can occur in private_with clauses. Example:
5701 -- private with B; package A is
5702 -- package C is function B return Integer;
5704 -- V1 : Integer := B;
5705 -- private function B return Integer;
5706 -- V2 : Integer := B;
5709 -- V1 resolves to A.B, but V2 resolves to library unit B
5711 elsif Ekind (E2) = E_Function
5712 and then Scope (E2) = Standard_Standard
5713 and then Has_Private_With (E2)
5715 Only_One_Visible := False;
5716 All_Overloadable := False;
5717 Nvis_Is_Private_Subprg := True;
5724 -- On falling through this loop, we have checked that there are no
5725 -- immediately visible entities. Only_One_Visible is set if exactly
5726 -- one potentially use visible entity exists. All_Overloadable is
5727 -- set if all the potentially use visible entities are overloadable.
5728 -- The condition for legality is that either there is one potentially
5729 -- use visible entity, or if there is more than one, then all of them
5730 -- are overloadable.
5732 if Only_One_Visible or All_Overloadable then
5735 -- If there is more than one potentially use-visible entity and at
5736 -- least one of them non-overloadable, we have an error (RM 8.4(11)).
5737 -- Note that E points to the first such entity on the homonym list.
5740 -- If one of the entities is declared in an actual package, it
5741 -- was visible in the generic, and takes precedence over other
5742 -- entities that are potentially use-visible. The same applies
5743 -- if the entity is declared in a local instantiation of the
5744 -- current instance.
5748 -- Find the current instance
5750 Inst := Current_Scope;
5751 while Present (Inst) and then Inst /= Standard_Standard loop
5752 if Is_Generic_Instance (Inst) then
5756 Inst := Scope (Inst);
5759 -- Reexamine the candidate entities, giving priority to those
5760 -- that were visible within the generic.
5763 while Present (E2) loop
5764 Nested_Inst := Nearest_Enclosing_Instance (E2);
5766 -- The entity is declared within an actual package, or in a
5767 -- nested instance. The ">=" accounts for the case where the
5768 -- current instance and the nested instance are the same.
5770 if From_Actual_Package (E2)
5771 or else (Present (Nested_Inst)
5772 and then Scope_Depth (Nested_Inst) >=
5785 elsif Is_Predefined_Unit (Current_Sem_Unit) then
5786 -- A use clause in the body of a system file creates conflict
5787 -- with some entity in a user scope, while rtsfind is active.
5788 -- Keep only the entity coming from another predefined unit.
5791 while Present (E2) loop
5792 if In_Predefined_Unit (E2) then
5800 -- Entity must exist because predefined unit is correct
5802 raise Program_Error;
5811 -- Come here with E set to the first immediately visible entity on
5812 -- the homonym chain. This is the one we want unless there is another
5813 -- immediately visible entity further on in the chain for an inner
5814 -- scope (RM 8.3(8)).
5816 <<Immediately_Visible_Entity>> declare
5821 -- Find scope level of initial entity. When compiling through
5822 -- Rtsfind, the previous context is not completely invisible, and
5823 -- an outer entity may appear on the chain, whose scope is below
5824 -- the entry for Standard that delimits the current scope stack.
5825 -- Indicate that the level for this spurious entry is outside of
5826 -- the current scope stack.
5828 Level := Scope_Stack.Last;
5830 Scop := Scope_Stack.Table (Level).Entity;
5831 exit when Scop = Scope (E);
5833 exit when Scop = Standard_Standard;
5836 -- Now search remainder of homonym chain for more inner entry
5837 -- If the entity is Standard itself, it has no scope, and we
5838 -- compare it with the stack entry directly.
5841 while Present (E2) loop
5842 if Is_Immediately_Visible (E2) then
5844 -- If a generic package contains a local declaration that
5845 -- has the same name as the generic, there may be a visibility
5846 -- conflict in an instance, where the local declaration must
5847 -- also hide the name of the corresponding package renaming.
5848 -- We check explicitly for a package declared by a renaming,
5849 -- whose renamed entity is an instance that is on the scope
5850 -- stack, and that contains a homonym in the same scope. Once
5851 -- we have found it, we know that the package renaming is not
5852 -- immediately visible, and that the identifier denotes the
5853 -- other entity (and its homonyms if overloaded).
5855 if Scope (E) = Scope (E2)
5856 and then Ekind (E) = E_Package
5857 and then Present (Renamed_Object (E))
5858 and then Is_Generic_Instance (Renamed_Object (E))
5859 and then In_Open_Scopes (Renamed_Object (E))
5860 and then Comes_From_Source (N)
5862 Set_Is_Immediately_Visible (E, False);
5866 for J in Level + 1 .. Scope_Stack.Last loop
5867 if Scope_Stack.Table (J).Entity = Scope (E2)
5868 or else Scope_Stack.Table (J).Entity = E2
5881 -- At the end of that loop, E is the innermost immediately
5882 -- visible entity, so we are all set.
5885 -- Come here with entity found, and stored in E
5889 -- Check violation of No_Wide_Characters restriction
5891 Check_Wide_Character_Restriction (E, N);
5893 -- When distribution features are available (Get_PCS_Name /=
5894 -- Name_No_DSA), a remote access-to-subprogram type is converted
5895 -- into a record type holding whatever information is needed to
5896 -- perform a remote call on an RCI subprogram. In that case we
5897 -- rewrite any occurrence of the RAS type into the equivalent record
5898 -- type here. 'Access attribute references and RAS dereferences are
5899 -- then implemented using specific TSSs. However when distribution is
5900 -- not available (case of Get_PCS_Name = Name_No_DSA), we bypass the
5901 -- generation of these TSSs, and we must keep the RAS type in its
5902 -- original access-to-subprogram form (since all calls through a
5903 -- value of such type will be local anyway in the absence of a PCS).
5905 if Comes_From_Source (N)
5906 and then Is_Remote_Access_To_Subprogram_Type (E)
5907 and then Ekind (E) = E_Access_Subprogram_Type
5908 and then Expander_Active
5909 and then Get_PCS_Name /= Name_No_DSA
5911 Rewrite (N, New_Occurrence_Of (Equivalent_Type (E), Sloc (N)));
5915 -- Set the entity. Note that the reason we call Set_Entity for the
5916 -- overloadable case, as opposed to Set_Entity_With_Checks is
5917 -- that in the overloaded case, the initial call can set the wrong
5918 -- homonym. The call that sets the right homonym is in Sem_Res and
5919 -- that call does use Set_Entity_With_Checks, so we don't miss
5922 if Is_Overloadable (E) then
5925 Set_Entity_With_Checks (N, E);
5931 Set_Etype (N, Get_Full_View (Etype (E)));
5934 if Debug_Flag_E then
5935 Write_Str (" found ");
5936 Write_Entity_Info (E, " ");
5939 -- If the Ekind of the entity is Void, it means that all homonyms
5940 -- are hidden from all visibility (RM 8.3(5,14-20)). However, this
5941 -- test is skipped if the current scope is a record and the name is
5942 -- a pragma argument expression (case of Atomic and Volatile pragmas
5943 -- and possibly other similar pragmas added later, which are allowed
5944 -- to reference components in the current record).
5946 if Ekind (E) = E_Void
5948 (not Is_Record_Type (Current_Scope)
5949 or else Nkind (Parent (N)) /= N_Pragma_Argument_Association)
5951 Premature_Usage (N);
5953 -- If the entity is overloadable, collect all interpretations of the
5954 -- name for subsequent overload resolution. We optimize a bit here to
5955 -- do this only if we have an overloadable entity that is not on its
5956 -- own on the homonym chain.
5958 elsif Is_Overloadable (E)
5959 and then (Present (Homonym (E)) or else Current_Entity (N) /= E)
5961 Collect_Interps (N);
5963 -- If no homonyms were visible, the entity is unambiguous
5965 if not Is_Overloaded (N) then
5966 if Reference_OK and then not Is_Actual_Parameter then
5967 Generate_Reference (E, N);
5971 -- Case of non-overloadable entity, set the entity providing that
5972 -- we do not have the case of a discriminant reference within a
5973 -- default expression. Such references are replaced with the
5974 -- corresponding discriminal, which is the formal corresponding to
5975 -- to the discriminant in the initialization procedure.
5978 -- Entity is unambiguous, indicate that it is referenced here
5980 -- For a renaming of an object, always generate simple reference,
5981 -- we don't try to keep track of assignments in this case, except
5982 -- in SPARK mode where renamings are traversed for generating
5983 -- local effects of subprograms.
5986 and then Is_Object (E)
5987 and then Present (Renamed_Object (E))
5988 and then not GNATprove_Mode
5990 Generate_Reference (E, N);
5992 -- If the renamed entity is a private protected component,
5993 -- reference the original component as well. This needs to be
5994 -- done because the private renamings are installed before any
5995 -- analysis has occurred. Reference to a private component will
5996 -- resolve to the renaming and the original component will be
5997 -- left unreferenced, hence the following.
5999 if Is_Prival (E) then
6000 Generate_Reference (Prival_Link (E), N);
6003 -- One odd case is that we do not want to set the Referenced flag
6004 -- if the entity is a label, and the identifier is the label in
6005 -- the source, since this is not a reference from the point of
6006 -- view of the user.
6008 elsif Nkind (Parent (N)) = N_Label then
6010 R : constant Boolean := Referenced (E);
6013 -- Generate reference unless this is an actual parameter
6014 -- (see comment below)
6016 if Reference_OK and then Is_Actual_Parameter then
6017 Generate_Reference (E, N);
6018 Set_Referenced (E, R);
6022 -- Normal case, not a label: generate reference
6025 if Reference_OK and then not Is_Actual_Parameter then
6027 -- Package or generic package is always a simple reference
6029 if Is_Package_Or_Generic_Package (E) then
6030 Generate_Reference (E, N, 'r');
6032 -- Else see if we have a left hand side
6037 Generate_Reference (E, N, 'm');
6040 Generate_Reference (E, N, 'r');
6042 -- If we don't know now, generate reference later
6045 Deferred_References.Append ((E, N));
6051 Set_Entity_Or_Discriminal (N, E);
6053 -- The name may designate a generalized reference, in which case
6054 -- the dereference interpretation will be included. Context is
6055 -- one in which a name is legal.
6057 if Ada_Version >= Ada_2012
6059 (Nkind (Parent (N)) in N_Subexpr
6060 or else Nkind_In (Parent (N), N_Assignment_Statement,
6061 N_Object_Declaration,
6062 N_Parameter_Association))
6064 Check_Implicit_Dereference (N, Etype (E));
6069 -- Mark relevant use-type and use-package clauses as effective if the
6070 -- node in question is not overloaded and therefore does not require
6073 -- Note: Generic actual subprograms do not follow the normal resolution
6074 -- path, so ignore the fact that they are overloaded and mark them
6077 if Nkind (N) not in N_Subexpr or else not Is_Overloaded (N) then
6078 Mark_Use_Clauses (N);
6081 -- Come here with entity set
6084 Check_Restriction_No_Use_Of_Entity (N);
6086 -- Annotate the tree by creating a variable reference marker in case the
6087 -- original variable reference is folded or optimized away. The variable
6088 -- reference marker is automatically saved for later examination by the
6089 -- ABE Processing phase. Variable references which act as actuals in a
6090 -- call require special processing and are left to Resolve_Actuals. The
6091 -- reference is a write when it appears on the left hand side of an
6095 and then Needs_Variable_Reference_Marker
6100 Is_Assignment_LHS : constant Boolean := Is_LHS (N) = Yes;
6103 Build_Variable_Reference_Marker
6105 Read => not Is_Assignment_LHS,
6106 Write => Is_Assignment_LHS);
6109 end Find_Direct_Name;
6111 ------------------------
6112 -- Find_Expanded_Name --
6113 ------------------------
6115 -- This routine searches the homonym chain of the entity until it finds
6116 -- an entity declared in the scope denoted by the prefix. If the entity
6117 -- is private, it may nevertheless be immediately visible, if we are in
6118 -- the scope of its declaration.
6120 procedure Find_Expanded_Name (N : Node_Id) is
6121 function In_Abstract_View_Pragma (Nod : Node_Id) return Boolean;
6122 -- Determine whether expanded name Nod appears within a pragma which is
6123 -- a suitable context for an abstract view of a state or variable. The
6124 -- following pragmas fall in this category:
6131 -- In addition, pragma Abstract_State is also considered suitable even
6132 -- though it is an illegal context for an abstract view as this allows
6133 -- for proper resolution of abstract views of variables. This illegal
6134 -- context is later flagged in the analysis of indicator Part_Of.
6136 -----------------------------
6137 -- In_Abstract_View_Pragma --
6138 -----------------------------
6140 function In_Abstract_View_Pragma (Nod : Node_Id) return Boolean is
6144 -- Climb the parent chain looking for a pragma
6147 while Present (Par) loop
6148 if Nkind (Par) = N_Pragma then
6149 if Nam_In (Pragma_Name_Unmapped (Par),
6150 Name_Abstract_State,
6154 Name_Refined_Depends,
6155 Name_Refined_Global)
6159 -- Otherwise the pragma is not a legal context for an abstract
6166 -- Prevent the search from going too far
6168 elsif Is_Body_Or_Package_Declaration (Par) then
6172 Par := Parent (Par);
6176 end In_Abstract_View_Pragma;
6180 Selector : constant Node_Id := Selector_Name (N);
6182 Candidate : Entity_Id := Empty;
6186 -- Start of processing for Find_Expanded_Name
6189 P_Name := Entity (Prefix (N));
6191 -- If the prefix is a renamed package, look for the entity in the
6192 -- original package.
6194 if Ekind (P_Name) = E_Package
6195 and then Present (Renamed_Object (P_Name))
6197 P_Name := Renamed_Object (P_Name);
6199 -- Rewrite node with entity field pointing to renamed object
6201 Rewrite (Prefix (N), New_Copy (Prefix (N)));
6202 Set_Entity (Prefix (N), P_Name);
6204 -- If the prefix is an object of a concurrent type, look for
6205 -- the entity in the associated task or protected type.
6207 elsif Is_Concurrent_Type (Etype (P_Name)) then
6208 P_Name := Etype (P_Name);
6211 Id := Current_Entity (Selector);
6214 Is_New_Candidate : Boolean;
6217 while Present (Id) loop
6218 if Scope (Id) = P_Name then
6220 Is_New_Candidate := True;
6222 -- Handle abstract views of states and variables. These are
6223 -- acceptable candidates only when the reference to the view
6224 -- appears in certain pragmas.
6226 if Ekind (Id) = E_Abstract_State
6227 and then From_Limited_With (Id)
6228 and then Present (Non_Limited_View (Id))
6230 if In_Abstract_View_Pragma (N) then
6231 Candidate := Non_Limited_View (Id);
6232 Is_New_Candidate := True;
6234 -- Hide the candidate because it is not used in a proper
6239 Is_New_Candidate := False;
6243 -- Ada 2005 (AI-217): Handle shadow entities associated with
6244 -- types declared in limited-withed nested packages. We don't need
6245 -- to handle E_Incomplete_Subtype entities because the entities
6246 -- in the limited view are always E_Incomplete_Type and
6247 -- E_Class_Wide_Type entities (see Build_Limited_Views).
6249 -- Regarding the expression used to evaluate the scope, it
6250 -- is important to note that the limited view also has shadow
6251 -- entities associated nested packages. For this reason the
6252 -- correct scope of the entity is the scope of the real entity.
6253 -- The non-limited view may itself be incomplete, in which case
6254 -- get the full view if available.
6256 elsif Ekind_In (Id, E_Incomplete_Type, E_Class_Wide_Type)
6257 and then From_Limited_With (Id)
6258 and then Present (Non_Limited_View (Id))
6259 and then Scope (Non_Limited_View (Id)) = P_Name
6261 Candidate := Get_Full_View (Non_Limited_View (Id));
6262 Is_New_Candidate := True;
6264 -- An unusual case arises with a fully qualified name for an
6265 -- entity local to a generic child unit package, within an
6266 -- instantiation of that package. The name of the unit now
6267 -- denotes the renaming created within the instance. This is
6268 -- only relevant in an instance body, see below.
6270 elsif Is_Generic_Instance (Scope (Id))
6271 and then In_Open_Scopes (Scope (Id))
6272 and then In_Instance_Body
6273 and then Ekind (Scope (Id)) = E_Package
6274 and then Ekind (Id) = E_Package
6275 and then Renamed_Entity (Id) = Scope (Id)
6276 and then Is_Immediately_Visible (P_Name)
6278 Is_New_Candidate := True;
6281 Is_New_Candidate := False;
6284 if Is_New_Candidate then
6286 -- If entity is a child unit, either it is a visible child of
6287 -- the prefix, or we are in the body of a generic prefix, as
6288 -- will happen when a child unit is instantiated in the body
6289 -- of a generic parent. This is because the instance body does
6290 -- not restore the full compilation context, given that all
6291 -- non-local references have been captured.
6293 if Is_Child_Unit (Id) or else P_Name = Standard_Standard then
6294 exit when Is_Visible_Lib_Unit (Id)
6295 or else (Is_Child_Unit (Id)
6296 and then In_Open_Scopes (Scope (Id))
6297 and then In_Instance_Body);
6299 exit when not Is_Hidden (Id);
6302 exit when Is_Immediately_Visible (Id);
6310 and then Ekind_In (P_Name, E_Procedure, E_Function)
6311 and then Is_Generic_Instance (P_Name)
6313 -- Expanded name denotes entity in (instance of) generic subprogram.
6314 -- The entity may be in the subprogram instance, or may denote one of
6315 -- the formals, which is declared in the enclosing wrapper package.
6317 P_Name := Scope (P_Name);
6319 Id := Current_Entity (Selector);
6320 while Present (Id) loop
6321 exit when Scope (Id) = P_Name;
6326 if No (Id) or else Chars (Id) /= Chars (Selector) then
6327 Set_Etype (N, Any_Type);
6329 -- If we are looking for an entity defined in System, try to find it
6330 -- in the child package that may have been provided as an extension
6331 -- to System. The Extend_System pragma will have supplied the name of
6332 -- the extension, which may have to be loaded.
6334 if Chars (P_Name) = Name_System
6335 and then Scope (P_Name) = Standard_Standard
6336 and then Present (System_Extend_Unit)
6337 and then Present_System_Aux (N)
6339 Set_Entity (Prefix (N), System_Aux_Id);
6340 Find_Expanded_Name (N);
6343 -- There is an implicit instance of the predefined operator in
6344 -- the given scope. The operator entity is defined in Standard.
6345 -- Has_Implicit_Operator makes the node into an Expanded_Name.
6347 elsif Nkind (Selector) = N_Operator_Symbol
6348 and then Has_Implicit_Operator (N)
6352 -- If there is no literal defined in the scope denoted by the
6353 -- prefix, the literal may belong to (a type derived from)
6354 -- Standard_Character, for which we have no explicit literals.
6356 elsif Nkind (Selector) = N_Character_Literal
6357 and then Has_Implicit_Character_Literal (N)
6362 -- If the prefix is a single concurrent object, use its name in
6363 -- the error message, rather than that of the anonymous type.
6365 if Is_Concurrent_Type (P_Name)
6366 and then Is_Internal_Name (Chars (P_Name))
6368 Error_Msg_Node_2 := Entity (Prefix (N));
6370 Error_Msg_Node_2 := P_Name;
6373 if P_Name = System_Aux_Id then
6374 P_Name := Scope (P_Name);
6375 Set_Entity (Prefix (N), P_Name);
6378 if Present (Candidate) then
6380 -- If we know that the unit is a child unit we can give a more
6381 -- accurate error message.
6383 if Is_Child_Unit (Candidate) then
6385 -- If the candidate is a private child unit and we are in
6386 -- the visible part of a public unit, specialize the error
6387 -- message. There might be a private with_clause for it,
6388 -- but it is not currently active.
6390 if Is_Private_Descendant (Candidate)
6391 and then Ekind (Current_Scope) = E_Package
6392 and then not In_Private_Part (Current_Scope)
6393 and then not Is_Private_Descendant (Current_Scope)
6396 ("private child unit& is not visible here", Selector);
6398 -- Normal case where we have a missing with for a child unit
6401 Error_Msg_Qual_Level := 99;
6402 Error_Msg_NE -- CODEFIX
6403 ("missing `WITH &;`", Selector, Candidate);
6404 Error_Msg_Qual_Level := 0;
6407 -- Here we don't know that this is a child unit
6410 Error_Msg_NE ("& is not a visible entity of&", N, Selector);
6414 -- Within the instantiation of a child unit, the prefix may
6415 -- denote the parent instance, but the selector has the name
6416 -- of the original child. That is to say, when A.B appears
6417 -- within an instantiation of generic child unit B, the scope
6418 -- stack includes an instance of A (P_Name) and an instance
6419 -- of B under some other name. We scan the scope to find this
6420 -- child instance, which is the desired entity.
6421 -- Note that the parent may itself be a child instance, if
6422 -- the reference is of the form A.B.C, in which case A.B has
6423 -- already been rewritten with the proper entity.
6425 if In_Open_Scopes (P_Name)
6426 and then Is_Generic_Instance (P_Name)
6429 Gen_Par : constant Entity_Id :=
6430 Generic_Parent (Specification
6431 (Unit_Declaration_Node (P_Name)));
6432 S : Entity_Id := Current_Scope;
6436 for J in reverse 0 .. Scope_Stack.Last loop
6437 S := Scope_Stack.Table (J).Entity;
6439 exit when S = Standard_Standard;
6441 if Ekind_In (S, E_Function,
6446 Generic_Parent (Specification
6447 (Unit_Declaration_Node (S)));
6449 -- Check that P is a generic child of the generic
6450 -- parent of the prefix.
6453 and then Chars (P) = Chars (Selector)
6454 and then Scope (P) = Gen_Par
6465 -- If this is a selection from Ada, System or Interfaces, then
6466 -- we assume a missing with for the corresponding package.
6468 if Is_Known_Unit (N)
6469 and then not (Present (Entity (Prefix (N)))
6470 and then Scope (Entity (Prefix (N))) /=
6473 if not Error_Posted (N) then
6474 Error_Msg_Node_2 := Selector;
6475 Error_Msg_N -- CODEFIX
6476 ("missing `WITH &.&;`", Prefix (N));
6479 -- If this is a selection from a dummy package, then suppress
6480 -- the error message, of course the entity is missing if the
6481 -- package is missing.
6483 elsif Sloc (Error_Msg_Node_2) = No_Location then
6486 -- Here we have the case of an undefined component
6489 -- The prefix may hide a homonym in the context that
6490 -- declares the desired entity. This error can use a
6491 -- specialized message.
6493 if In_Open_Scopes (P_Name) then
6495 H : constant Entity_Id := Homonym (P_Name);
6499 and then Is_Compilation_Unit (H)
6501 (Is_Immediately_Visible (H)
6502 or else Is_Visible_Lib_Unit (H))
6504 Id := First_Entity (H);
6505 while Present (Id) loop
6506 if Chars (Id) = Chars (Selector) then
6507 Error_Msg_Qual_Level := 99;
6508 Error_Msg_Name_1 := Chars (Selector);
6510 ("% not declared in&", N, P_Name);
6512 ("\use fully qualified name starting with "
6513 & "Standard to make& visible", N, H);
6514 Error_Msg_Qual_Level := 0;
6522 -- If not found, standard error message
6524 Error_Msg_NE ("& not declared in&", N, Selector);
6530 -- Might be worth specializing the case when the prefix
6531 -- is a limited view.
6532 -- ... not declared in limited view of...
6534 Error_Msg_NE ("& not declared in&", N, Selector);
6537 -- Check for misspelling of some entity in prefix
6539 Id := First_Entity (P_Name);
6540 while Present (Id) loop
6541 if Is_Bad_Spelling_Of (Chars (Id), Chars (Selector))
6542 and then not Is_Internal_Name (Chars (Id))
6544 Error_Msg_NE -- CODEFIX
6545 ("possible misspelling of&", Selector, Id);
6552 -- Specialize the message if this may be an instantiation
6553 -- of a child unit that was not mentioned in the context.
6555 if Nkind (Parent (N)) = N_Package_Instantiation
6556 and then Is_Generic_Instance (Entity (Prefix (N)))
6557 and then Is_Compilation_Unit
6558 (Generic_Parent (Parent (Entity (Prefix (N)))))
6560 Error_Msg_Node_2 := Selector;
6561 Error_Msg_N -- CODEFIX
6562 ("\missing `WITH &.&;`", Prefix (N));
6572 if Comes_From_Source (N)
6573 and then Is_Remote_Access_To_Subprogram_Type (Id)
6574 and then Ekind (Id) = E_Access_Subprogram_Type
6575 and then Present (Equivalent_Type (Id))
6577 -- If we are not actually generating distribution code (i.e. the
6578 -- current PCS is the dummy non-distributed version), then the
6579 -- Equivalent_Type will be missing, and Id should be treated as
6580 -- a regular access-to-subprogram type.
6582 Id := Equivalent_Type (Id);
6583 Set_Chars (Selector, Chars (Id));
6586 -- Ada 2005 (AI-50217): Check usage of entities in limited withed units
6588 if Ekind (P_Name) = E_Package and then From_Limited_With (P_Name) then
6589 if From_Limited_With (Id)
6590 or else Is_Type (Id)
6591 or else Ekind (Id) = E_Package
6596 ("limited withed package can only be used to access incomplete "
6601 if Is_Task_Type (P_Name)
6602 and then ((Ekind (Id) = E_Entry
6603 and then Nkind (Parent (N)) /= N_Attribute_Reference)
6605 (Ekind (Id) = E_Entry_Family
6607 Nkind (Parent (Parent (N))) /= N_Attribute_Reference))
6609 -- If both the task type and the entry are in scope, this may still
6610 -- be the expanded name of an entry formal.
6612 if In_Open_Scopes (Id)
6613 and then Nkind (Parent (N)) = N_Selected_Component
6618 -- It is an entry call after all, either to the current task
6619 -- (which will deadlock) or to an enclosing task.
6621 Analyze_Selected_Component (N);
6626 Change_Selected_Component_To_Expanded_Name (N);
6628 -- Preserve relevant elaboration-related attributes of the context which
6629 -- are no longer available or very expensive to recompute once analysis,
6630 -- resolution, and expansion are over.
6632 Mark_Elaboration_Attributes
6638 -- Set appropriate type
6640 if Is_Type (Id) then
6643 Set_Etype (N, Get_Full_View (Etype (Id)));
6646 -- Do style check and generate reference, but skip both steps if this
6647 -- entity has homonyms, since we may not have the right homonym set yet.
6648 -- The proper homonym will be set during the resolve phase.
6650 if Has_Homonym (Id) then
6654 Set_Entity_Or_Discriminal (N, Id);
6658 Generate_Reference (Id, N, 'm');
6661 Generate_Reference (Id, N, 'r');
6664 Deferred_References.Append ((Id, N));
6668 -- Check for violation of No_Wide_Characters
6670 Check_Wide_Character_Restriction (Id, N);
6672 -- If the Ekind of the entity is Void, it means that all homonyms are
6673 -- hidden from all visibility (RM 8.3(5,14-20)).
6675 if Ekind (Id) = E_Void then
6676 Premature_Usage (N);
6678 elsif Is_Overloadable (Id) and then Present (Homonym (Id)) then
6680 H : Entity_Id := Homonym (Id);
6683 while Present (H) loop
6684 if Scope (H) = Scope (Id)
6685 and then (not Is_Hidden (H)
6686 or else Is_Immediately_Visible (H))
6688 Collect_Interps (N);
6695 -- If an extension of System is present, collect possible explicit
6696 -- overloadings declared in the extension.
6698 if Chars (P_Name) = Name_System
6699 and then Scope (P_Name) = Standard_Standard
6700 and then Present (System_Extend_Unit)
6701 and then Present_System_Aux (N)
6703 H := Current_Entity (Id);
6705 while Present (H) loop
6706 if Scope (H) = System_Aux_Id then
6707 Add_One_Interp (N, H, Etype (H));
6716 if Nkind (Selector_Name (N)) = N_Operator_Symbol
6717 and then Scope (Id) /= Standard_Standard
6719 -- In addition to user-defined operators in the given scope, there
6720 -- may be an implicit instance of the predefined operator. The
6721 -- operator (defined in Standard) is found in Has_Implicit_Operator,
6722 -- and added to the interpretations. Procedure Add_One_Interp will
6723 -- determine which hides which.
6725 if Has_Implicit_Operator (N) then
6730 -- If there is a single interpretation for N we can generate a
6731 -- reference to the unique entity found.
6733 if Is_Overloadable (Id) and then not Is_Overloaded (N) then
6734 Generate_Reference (Id, N);
6737 -- Mark relevant use-type and use-package clauses as effective if the
6738 -- node in question is not overloaded and therefore does not require
6741 if Nkind (N) not in N_Subexpr or else not Is_Overloaded (N) then
6742 Mark_Use_Clauses (N);
6745 Check_Restriction_No_Use_Of_Entity (N);
6747 -- Annotate the tree by creating a variable reference marker in case the
6748 -- original variable reference is folded or optimized away. The variable
6749 -- reference marker is automatically saved for later examination by the
6750 -- ABE Processing phase. Variable references which act as actuals in a
6751 -- call require special processing and are left to Resolve_Actuals. The
6752 -- reference is a write when it appears on the left hand side of an
6755 if Needs_Variable_Reference_Marker
6760 Is_Assignment_LHS : constant Boolean := Is_LHS (N) = Yes;
6763 Build_Variable_Reference_Marker
6765 Read => not Is_Assignment_LHS,
6766 Write => Is_Assignment_LHS);
6769 end Find_Expanded_Name;
6771 --------------------
6772 -- Find_Most_Prev --
6773 --------------------
6775 function Find_Most_Prev (Use_Clause : Node_Id) return Node_Id is
6779 -- Loop through the Prev_Use_Clause chain
6782 while Present (Prev_Use_Clause (Curr)) loop
6783 Curr := Prev_Use_Clause (Curr);
6789 -------------------------
6790 -- Find_Renamed_Entity --
6791 -------------------------
6793 function Find_Renamed_Entity
6797 Is_Actual : Boolean := False) return Entity_Id
6800 I1 : Interp_Index := 0; -- Suppress junk warnings
6806 function Find_Nearer_Entity
6809 Old2_S : Entity_Id) return Entity_Id;
6810 -- Determine whether one of Old_S1 and Old_S2 is nearer to New_S than
6811 -- the other, and return it if so. Return Empty otherwise. We use this
6812 -- in conjunction with Inherit_Renamed_Profile to simplify later type
6813 -- disambiguation for actual subprograms in instances.
6815 function Is_Visible_Operation (Op : Entity_Id) return Boolean;
6816 -- If the renamed entity is an implicit operator, check whether it is
6817 -- visible because its operand type is properly visible. This check
6818 -- applies to explicit renamed entities that appear in the source in a
6819 -- renaming declaration or a formal subprogram instance, but not to
6820 -- default generic actuals with a name.
6822 function Report_Overload return Entity_Id;
6823 -- List possible interpretations, and specialize message in the
6824 -- case of a generic actual.
6826 function Within (Inner, Outer : Entity_Id) return Boolean;
6827 -- Determine whether a candidate subprogram is defined within the
6828 -- enclosing instance. If yes, it has precedence over outer candidates.
6830 --------------------------
6831 -- Find_Nearer_Entity --
6832 --------------------------
6834 function Find_Nearer_Entity
6837 Old2_S : Entity_Id) return Entity_Id
6845 New_F := First_Formal (New_S);
6846 Old1_F := First_Formal (Old1_S);
6847 Old2_F := First_Formal (Old2_S);
6849 -- The criterion is whether the type of the formals of one of Old1_S
6850 -- and Old2_S is an ancestor subtype of the type of the corresponding
6851 -- formals of New_S while the other is not (we already know that they
6852 -- are all subtypes of the same base type).
6854 -- This makes it possible to find the more correct renamed entity in
6855 -- the case of a generic instantiation nested in an enclosing one for
6856 -- which different formal types get the same actual type, which will
6857 -- in turn make it possible for Inherit_Renamed_Profile to preserve
6858 -- types on formal parameters and ultimately simplify disambiguation.
6860 -- Consider the follow package G:
6863 -- type Item_T is private;
6864 -- with function Compare (L, R: Item_T) return Boolean is <>;
6866 -- type Bound_T is private;
6867 -- with function Compare (L, R : Bound_T) return Boolean is <>;
6872 -- package body G is
6873 -- package My_Inner is Inner_G (Bound_T);
6877 -- with the following package Inner_G:
6880 -- type T is private;
6881 -- with function Compare (L, R: T) return Boolean is <>;
6882 -- package Inner_G is
6883 -- function "<" (L, R: T) return Boolean is (Compare (L, R));
6886 -- If G is instantiated on the same actual type with a single Compare
6890 -- function Compare (L, R : T) return Boolean;
6891 -- package My_G is new (T, T);
6893 -- then the renaming generated for Compare in the inner instantiation
6894 -- is ambiguous: it can rename either of the renamings generated for
6895 -- the outer instantiation. Now if the first one is picked up, then
6896 -- the subtypes of the formal parameters of the renaming will not be
6897 -- preserved in Inherit_Renamed_Profile because they are subtypes of
6898 -- the Bound_T formal type and not of the Item_T formal type, so we
6899 -- need to arrange for the second one to be picked up instead.
6901 while Present (New_F) loop
6902 if Etype (Old1_F) /= Etype (Old2_F) then
6903 Anc_T := Ancestor_Subtype (Etype (New_F));
6905 if Etype (Old1_F) = Anc_T then
6907 elsif Etype (Old2_F) = Anc_T then
6912 Next_Formal (New_F);
6913 Next_Formal (Old1_F);
6914 Next_Formal (Old2_F);
6917 pragma Assert (No (Old1_F));
6918 pragma Assert (No (Old2_F));
6921 end Find_Nearer_Entity;
6923 --------------------------
6924 -- Is_Visible_Operation --
6925 --------------------------
6927 function Is_Visible_Operation (Op : Entity_Id) return Boolean is
6933 if Ekind (Op) /= E_Operator
6934 or else Scope (Op) /= Standard_Standard
6935 or else (In_Instance
6936 and then (not Is_Actual
6937 or else Present (Enclosing_Instance)))
6942 -- For a fixed point type operator, check the resulting type,
6943 -- because it may be a mixed mode integer * fixed operation.
6945 if Present (Next_Formal (First_Formal (New_S)))
6946 and then Is_Fixed_Point_Type (Etype (New_S))
6948 Typ := Etype (New_S);
6950 Typ := Etype (First_Formal (New_S));
6953 Btyp := Base_Type (Typ);
6955 if Nkind (Nam) /= N_Expanded_Name then
6956 return (In_Open_Scopes (Scope (Btyp))
6957 or else Is_Potentially_Use_Visible (Btyp)
6958 or else In_Use (Btyp)
6959 or else In_Use (Scope (Btyp)));
6962 Scop := Entity (Prefix (Nam));
6964 if Ekind (Scop) = E_Package
6965 and then Present (Renamed_Object (Scop))
6967 Scop := Renamed_Object (Scop);
6970 -- Operator is visible if prefix of expanded name denotes
6971 -- scope of type, or else type is defined in System_Aux
6972 -- and the prefix denotes System.
6974 return Scope (Btyp) = Scop
6975 or else (Scope (Btyp) = System_Aux_Id
6976 and then Scope (Scope (Btyp)) = Scop);
6979 end Is_Visible_Operation;
6985 function Within (Inner, Outer : Entity_Id) return Boolean is
6989 Sc := Scope (Inner);
6990 while Sc /= Standard_Standard loop
7001 ---------------------
7002 -- Report_Overload --
7003 ---------------------
7005 function Report_Overload return Entity_Id is
7008 Error_Msg_NE -- CODEFIX
7009 ("ambiguous actual subprogram&, " &
7010 "possible interpretations:", N, Nam);
7012 Error_Msg_N -- CODEFIX
7013 ("ambiguous subprogram, " &
7014 "possible interpretations:", N);
7017 List_Interps (Nam, N);
7019 end Report_Overload;
7021 -- Start of processing for Find_Renamed_Entity
7025 Candidate_Renaming := Empty;
7027 if Is_Overloaded (Nam) then
7028 Get_First_Interp (Nam, Ind, It);
7029 while Present (It.Nam) loop
7030 if Entity_Matches_Spec (It.Nam, New_S)
7031 and then Is_Visible_Operation (It.Nam)
7033 if Old_S /= Any_Id then
7035 -- Note: The call to Disambiguate only happens if a
7036 -- previous interpretation was found, in which case I1
7037 -- has received a value.
7039 It1 := Disambiguate (Nam, I1, Ind, Etype (Old_S));
7041 if It1 = No_Interp then
7042 Inst := Enclosing_Instance;
7044 if Present (Inst) then
7045 if Within (It.Nam, Inst) then
7046 if Within (Old_S, Inst) then
7048 It_D : constant Uint := Scope_Depth (It.Nam);
7049 Old_D : constant Uint := Scope_Depth (Old_S);
7052 -- Choose the innermost subprogram, which
7053 -- would hide the outer one in the generic.
7055 if Old_D > It_D then
7057 elsif It_D > Old_D then
7061 -- Otherwise, if we can determine that one
7062 -- of the entities is nearer to the renaming
7063 -- than the other, choose it. If not, then
7064 -- return the newer one as done historically.
7067 Find_Nearer_Entity (New_S, Old_S, It.Nam);
7068 if Present (N_Ent) then
7076 elsif Within (Old_S, Inst) then
7080 return Report_Overload;
7083 -- If not within an instance, ambiguity is real
7086 return Report_Overload;
7100 Present (First_Formal (It.Nam))
7101 and then Present (First_Formal (New_S))
7102 and then (Base_Type (Etype (First_Formal (It.Nam))) =
7103 Base_Type (Etype (First_Formal (New_S))))
7105 Candidate_Renaming := It.Nam;
7108 Get_Next_Interp (Ind, It);
7111 Set_Entity (Nam, Old_S);
7113 if Old_S /= Any_Id then
7114 Set_Is_Overloaded (Nam, False);
7117 -- Non-overloaded case
7121 and then Present (Enclosing_Instance)
7122 and then Entity_Matches_Spec (Entity (Nam), New_S)
7124 Old_S := Entity (Nam);
7126 elsif Entity_Matches_Spec (Entity (Nam), New_S) then
7127 Candidate_Renaming := New_S;
7129 if Is_Visible_Operation (Entity (Nam)) then
7130 Old_S := Entity (Nam);
7133 elsif Present (First_Formal (Entity (Nam)))
7134 and then Present (First_Formal (New_S))
7135 and then (Base_Type (Etype (First_Formal (Entity (Nam)))) =
7136 Base_Type (Etype (First_Formal (New_S))))
7138 Candidate_Renaming := Entity (Nam);
7143 end Find_Renamed_Entity;
7145 -----------------------------
7146 -- Find_Selected_Component --
7147 -----------------------------
7149 procedure Find_Selected_Component (N : Node_Id) is
7150 P : constant Node_Id := Prefix (N);
7153 -- Entity denoted by prefix
7160 function Available_Subtype return Boolean;
7161 -- A small optimization: if the prefix is constrained and the component
7162 -- is an array type we may already have a usable subtype for it, so we
7163 -- can use it rather than generating a new one, because the bounds
7164 -- will be the values of the discriminants and not discriminant refs.
7165 -- This simplifies value tracing in GNATProve. For consistency, both
7166 -- the entity name and the subtype come from the constrained component.
7168 -- This is only used in GNATProve mode: when generating code it may be
7169 -- necessary to create an itype in the scope of use of the selected
7170 -- component, e.g. in the context of a expanded record equality.
7172 function Is_Reference_In_Subunit return Boolean;
7173 -- In a subunit, the scope depth is not a proper measure of hiding,
7174 -- because the context of the proper body may itself hide entities in
7175 -- parent units. This rare case requires inspecting the tree directly
7176 -- because the proper body is inserted in the main unit and its context
7177 -- is simply added to that of the parent.
7179 -----------------------
7180 -- Available_Subtype --
7181 -----------------------
7183 function Available_Subtype return Boolean is
7187 if GNATprove_Mode then
7188 Comp := First_Entity (Etype (P));
7189 while Present (Comp) loop
7190 if Chars (Comp) = Chars (Selector_Name (N)) then
7191 Set_Etype (N, Etype (Comp));
7192 Set_Entity (Selector_Name (N), Comp);
7193 Set_Etype (Selector_Name (N), Etype (Comp));
7197 Next_Component (Comp);
7202 end Available_Subtype;
7204 -----------------------------
7205 -- Is_Reference_In_Subunit --
7206 -----------------------------
7208 function Is_Reference_In_Subunit return Boolean is
7210 Comp_Unit : Node_Id;
7214 while Present (Comp_Unit)
7215 and then Nkind (Comp_Unit) /= N_Compilation_Unit
7217 Comp_Unit := Parent (Comp_Unit);
7220 if No (Comp_Unit) or else Nkind (Unit (Comp_Unit)) /= N_Subunit then
7224 -- Now check whether the package is in the context of the subunit
7226 Clause := First (Context_Items (Comp_Unit));
7227 while Present (Clause) loop
7228 if Nkind (Clause) = N_With_Clause
7229 and then Entity (Name (Clause)) = P_Name
7238 end Is_Reference_In_Subunit;
7240 -- Start of processing for Find_Selected_Component
7245 if Nkind (P) = N_Error then
7249 -- If the selector already has an entity, the node has been constructed
7250 -- in the course of expansion, and is known to be valid. Do not verify
7251 -- that it is defined for the type (it may be a private component used
7252 -- in the expansion of record equality).
7254 if Present (Entity (Selector_Name (N))) then
7255 if No (Etype (N)) or else Etype (N) = Any_Type then
7257 Sel_Name : constant Node_Id := Selector_Name (N);
7258 Selector : constant Entity_Id := Entity (Sel_Name);
7262 Set_Etype (Sel_Name, Etype (Selector));
7264 if not Is_Entity_Name (P) then
7268 -- Build an actual subtype except for the first parameter
7269 -- of an init proc, where this actual subtype is by
7270 -- definition incorrect, since the object is uninitialized
7271 -- (and does not even have defined discriminants etc.)
7273 if Is_Entity_Name (P)
7274 and then Ekind (Entity (P)) = E_Function
7276 Nam := New_Copy (P);
7278 if Is_Overloaded (P) then
7279 Save_Interps (P, Nam);
7282 Rewrite (P, Make_Function_Call (Sloc (P), Name => Nam));
7284 Analyze_Selected_Component (N);
7287 elsif Ekind (Selector) = E_Component
7288 and then (not Is_Entity_Name (P)
7289 or else Chars (Entity (P)) /= Name_uInit)
7291 -- Check if we already have an available subtype we can use
7293 if Ekind (Etype (P)) = E_Record_Subtype
7294 and then Nkind (Parent (Etype (P))) = N_Subtype_Declaration
7295 and then Is_Array_Type (Etype (Selector))
7296 and then not Is_Packed (Etype (Selector))
7297 and then Available_Subtype
7301 -- Do not build the subtype when referencing components of
7302 -- dispatch table wrappers. Required to avoid generating
7303 -- elaboration code with HI runtimes.
7305 elsif RTU_Loaded (Ada_Tags)
7307 ((RTE_Available (RE_Dispatch_Table_Wrapper)
7308 and then Scope (Selector) =
7309 RTE (RE_Dispatch_Table_Wrapper))
7311 (RTE_Available (RE_No_Dispatch_Table_Wrapper)
7312 and then Scope (Selector) =
7313 RTE (RE_No_Dispatch_Table_Wrapper)))
7318 Build_Actual_Subtype_Of_Component
7319 (Etype (Selector), N);
7326 if No (C_Etype) then
7327 C_Etype := Etype (Selector);
7329 Insert_Action (N, C_Etype);
7330 C_Etype := Defining_Identifier (C_Etype);
7333 Set_Etype (N, C_Etype);
7336 -- If the selected component appears within a default expression
7337 -- and it has an actual subtype, the preanalysis has not yet
7338 -- completed its analysis, because Insert_Actions is disabled in
7339 -- that context. Within the init proc of the enclosing type we
7340 -- must complete this analysis, if an actual subtype was created.
7342 elsif Inside_Init_Proc then
7344 Typ : constant Entity_Id := Etype (N);
7345 Decl : constant Node_Id := Declaration_Node (Typ);
7347 if Nkind (Decl) = N_Subtype_Declaration
7348 and then not Analyzed (Decl)
7349 and then Is_List_Member (Decl)
7350 and then No (Parent (Decl))
7353 Insert_Action (N, Decl);
7360 elsif Is_Entity_Name (P) then
7361 P_Name := Entity (P);
7363 -- The prefix may denote an enclosing type which is the completion
7364 -- of an incomplete type declaration.
7366 if Is_Type (P_Name) then
7367 Set_Entity (P, Get_Full_View (P_Name));
7368 Set_Etype (P, Entity (P));
7369 P_Name := Entity (P);
7372 P_Type := Base_Type (Etype (P));
7374 if Debug_Flag_E then
7375 Write_Str ("Found prefix type to be ");
7376 Write_Entity_Info (P_Type, " "); Write_Eol;
7379 -- If the prefix's type is an access type, get to the record type
7381 if Is_Access_Type (P_Type) then
7382 P_Type := Implicitly_Designated_Type (P_Type);
7385 -- First check for components of a record object (not the
7386 -- result of a call, which is handled below).
7388 if Has_Components (P_Type)
7389 and then not Is_Overloadable (P_Name)
7390 and then not Is_Type (P_Name)
7392 -- Selected component of record. Type checking will validate
7393 -- name of selector.
7395 -- ??? Could we rewrite an implicit dereference into an explicit
7398 Analyze_Selected_Component (N);
7400 -- Reference to type name in predicate/invariant expression
7402 elsif (Is_Task_Type (P_Type) or else Is_Protected_Type (P_Type))
7403 and then not In_Open_Scopes (P_Name)
7404 and then (not Is_Concurrent_Type (Etype (P_Name))
7405 or else not In_Open_Scopes (Etype (P_Name)))
7407 -- Call to protected operation or entry. Type checking is
7408 -- needed on the prefix.
7410 Analyze_Selected_Component (N);
7412 elsif (In_Open_Scopes (P_Name)
7413 and then Ekind (P_Name) /= E_Void
7414 and then not Is_Overloadable (P_Name))
7415 or else (Is_Concurrent_Type (Etype (P_Name))
7416 and then In_Open_Scopes (Etype (P_Name)))
7418 -- Prefix denotes an enclosing loop, block, or task, i.e. an
7419 -- enclosing construct that is not a subprogram or accept.
7421 -- A special case: a protected body may call an operation
7422 -- on an external object of the same type, in which case it
7423 -- is not an expanded name. If the prefix is the type itself,
7424 -- or the context is a single synchronized object it can only
7425 -- be interpreted as an expanded name.
7427 if Is_Concurrent_Type (Etype (P_Name)) then
7429 or else Present (Anonymous_Object (Etype (P_Name)))
7431 Find_Expanded_Name (N);
7434 Analyze_Selected_Component (N);
7439 Find_Expanded_Name (N);
7442 elsif Ekind (P_Name) = E_Package then
7443 Find_Expanded_Name (N);
7445 elsif Is_Overloadable (P_Name) then
7447 -- The subprogram may be a renaming (of an enclosing scope) as
7448 -- in the case of the name of the generic within an instantiation.
7450 if Ekind_In (P_Name, E_Procedure, E_Function)
7451 and then Present (Alias (P_Name))
7452 and then Is_Generic_Instance (Alias (P_Name))
7454 P_Name := Alias (P_Name);
7457 if Is_Overloaded (P) then
7459 -- The prefix must resolve to a unique enclosing construct
7462 Found : Boolean := False;
7467 Get_First_Interp (P, Ind, It);
7468 while Present (It.Nam) loop
7469 if In_Open_Scopes (It.Nam) then
7472 "prefix must be unique enclosing scope", N);
7473 Set_Entity (N, Any_Id);
7474 Set_Etype (N, Any_Type);
7483 Get_Next_Interp (Ind, It);
7488 if In_Open_Scopes (P_Name) then
7489 Set_Entity (P, P_Name);
7490 Set_Is_Overloaded (P, False);
7491 Find_Expanded_Name (N);
7494 -- If no interpretation as an expanded name is possible, it
7495 -- must be a selected component of a record returned by a
7496 -- function call. Reformat prefix as a function call, the rest
7497 -- is done by type resolution.
7499 -- Error if the prefix is procedure or entry, as is P.X
7501 if Ekind (P_Name) /= E_Function
7503 (not Is_Overloaded (P)
7504 or else Nkind (Parent (N)) = N_Procedure_Call_Statement)
7506 -- Prefix may mention a package that is hidden by a local
7507 -- declaration: let the user know. Scan the full homonym
7508 -- chain, the candidate package may be anywhere on it.
7510 if Present (Homonym (Current_Entity (P_Name))) then
7511 P_Name := Current_Entity (P_Name);
7513 while Present (P_Name) loop
7514 exit when Ekind (P_Name) = E_Package;
7515 P_Name := Homonym (P_Name);
7518 if Present (P_Name) then
7519 if not Is_Reference_In_Subunit then
7520 Error_Msg_Sloc := Sloc (Entity (Prefix (N)));
7522 ("package& is hidden by declaration#", N, P_Name);
7525 Set_Entity (Prefix (N), P_Name);
7526 Find_Expanded_Name (N);
7530 P_Name := Entity (Prefix (N));
7535 ("invalid prefix in selected component&", N, P_Name);
7536 Change_Selected_Component_To_Expanded_Name (N);
7537 Set_Entity (N, Any_Id);
7538 Set_Etype (N, Any_Type);
7540 -- Here we have a function call, so do the reformatting
7543 Nam := New_Copy (P);
7544 Save_Interps (P, Nam);
7546 -- We use Replace here because this is one of those cases
7547 -- where the parser has missclassified the node, and we fix
7548 -- things up and then do the semantic analysis on the fixed
7549 -- up node. Normally we do this using one of the Sinfo.CN
7550 -- routines, but this is too tricky for that.
7552 -- Note that using Rewrite would be wrong, because we would
7553 -- have a tree where the original node is unanalyzed.
7556 Make_Function_Call (Sloc (P), Name => Nam));
7558 -- Now analyze the reformatted node
7562 -- If the prefix is illegal after this transformation, there
7563 -- may be visibility errors on the prefix. The safest is to
7564 -- treat the selected component as an error.
7566 if Error_Posted (P) then
7567 Set_Etype (N, Any_Type);
7571 Analyze_Selected_Component (N);
7576 -- Remaining cases generate various error messages
7579 -- Format node as expanded name, to avoid cascaded errors
7581 Change_Selected_Component_To_Expanded_Name (N);
7582 Set_Entity (N, Any_Id);
7583 Set_Etype (N, Any_Type);
7585 -- Issue error message, but avoid this if error issued already.
7586 -- Use identifier of prefix if one is available.
7588 if P_Name = Any_Id then
7591 -- It is not an error if the prefix is the current instance of
7592 -- type name, e.g. the expression of a type aspect, when it is
7593 -- analyzed within a generic unit. We still have to verify that a
7594 -- component of that name exists, and decorate the node
7597 elsif Is_Entity_Name (P) and then Is_Current_Instance (P) then
7602 Comp := First_Entity (Entity (P));
7603 while Present (Comp) loop
7604 if Chars (Comp) = Chars (Selector_Name (N)) then
7605 Set_Entity (N, Comp);
7606 Set_Etype (N, Etype (Comp));
7607 Set_Entity (Selector_Name (N), Comp);
7608 Set_Etype (Selector_Name (N), Etype (Comp));
7616 elsif Ekind (P_Name) = E_Void then
7617 Premature_Usage (P);
7619 elsif Nkind (P) /= N_Attribute_Reference then
7621 -- This may have been meant as a prefixed call to a primitive
7622 -- of an untagged type. If it is a function call check type of
7623 -- its first formal and add explanation.
7626 F : constant Entity_Id :=
7627 Current_Entity (Selector_Name (N));
7630 and then Is_Overloadable (F)
7631 and then Present (First_Entity (F))
7632 and then not Is_Tagged_Type (Etype (First_Entity (F)))
7635 ("prefixed call is only allowed for objects of a "
7636 & "tagged type", N);
7640 Error_Msg_N ("invalid prefix in selected component&", P);
7642 if Is_Incomplete_Type (P_Type)
7643 and then Is_Access_Type (Etype (P))
7646 ("\dereference must not be of an incomplete type "
7647 & "(RM 3.10.1)", P);
7651 Error_Msg_N ("invalid prefix in selected component", P);
7655 -- If prefix is not the name of an entity, it must be an expression,
7656 -- whose type is appropriate for a record. This is determined by
7659 Analyze_Selected_Component (N);
7662 Analyze_Dimension (N);
7663 end Find_Selected_Component;
7669 procedure Find_Type (N : Node_Id) is
7679 elsif Nkind (N) = N_Attribute_Reference then
7681 -- Class attribute. This is not valid in Ada 83 mode, but we do not
7682 -- need to enforce that at this point, since the declaration of the
7683 -- tagged type in the prefix would have been flagged already.
7685 if Attribute_Name (N) = Name_Class then
7686 Check_Restriction (No_Dispatch, N);
7687 Find_Type (Prefix (N));
7689 -- Propagate error from bad prefix
7691 if Etype (Prefix (N)) = Any_Type then
7692 Set_Entity (N, Any_Type);
7693 Set_Etype (N, Any_Type);
7697 T := Base_Type (Entity (Prefix (N)));
7699 -- Case where type is not known to be tagged. Its appearance in
7700 -- the prefix of the 'Class attribute indicates that the full view
7703 if not Is_Tagged_Type (T) then
7704 if Ekind (T) = E_Incomplete_Type then
7706 -- It is legal to denote the class type of an incomplete
7707 -- type. The full type will have to be tagged, of course.
7708 -- In Ada 2005 this usage is declared obsolescent, so we
7709 -- warn accordingly. This usage is only legal if the type
7710 -- is completed in the current scope, and not for a limited
7713 if Ada_Version >= Ada_2005 then
7715 -- Test whether the Available_View of a limited type view
7716 -- is tagged, since the limited view may not be marked as
7717 -- tagged if the type itself has an untagged incomplete
7718 -- type view in its package.
7720 if From_Limited_With (T)
7721 and then not Is_Tagged_Type (Available_View (T))
7724 ("prefix of Class attribute must be tagged", N);
7725 Set_Etype (N, Any_Type);
7726 Set_Entity (N, Any_Type);
7729 -- ??? This test is temporarily disabled (always
7730 -- False) because it causes an unwanted warning on
7731 -- GNAT sources (built with -gnatg, which includes
7732 -- Warn_On_Obsolescent_ Feature). Once this issue
7733 -- is cleared in the sources, it can be enabled.
7735 elsif Warn_On_Obsolescent_Feature and then False then
7737 ("applying 'Class to an untagged incomplete type"
7738 & " is an obsolescent feature (RM J.11)?r?", N);
7742 Set_Is_Tagged_Type (T);
7743 Set_Direct_Primitive_Operations (T, New_Elmt_List);
7744 Make_Class_Wide_Type (T);
7745 Set_Entity (N, Class_Wide_Type (T));
7746 Set_Etype (N, Class_Wide_Type (T));
7748 elsif Ekind (T) = E_Private_Type
7749 and then not Is_Generic_Type (T)
7750 and then In_Private_Part (Scope (T))
7752 -- The Class attribute can be applied to an untagged private
7753 -- type fulfilled by a tagged type prior to the full type
7754 -- declaration (but only within the parent package's private
7755 -- part). Create the class-wide type now and check that the
7756 -- full type is tagged later during its analysis. Note that
7757 -- we do not mark the private type as tagged, unlike the
7758 -- case of incomplete types, because the type must still
7759 -- appear untagged to outside units.
7761 if No (Class_Wide_Type (T)) then
7762 Make_Class_Wide_Type (T);
7765 Set_Entity (N, Class_Wide_Type (T));
7766 Set_Etype (N, Class_Wide_Type (T));
7769 -- Should we introduce a type Any_Tagged and use Wrong_Type
7770 -- here, it would be a bit more consistent???
7773 ("tagged type required, found}",
7774 Prefix (N), First_Subtype (T));
7775 Set_Entity (N, Any_Type);
7779 -- Case of tagged type
7782 if Is_Concurrent_Type (T) then
7783 if No (Corresponding_Record_Type (Entity (Prefix (N)))) then
7785 -- Previous error. Create a class-wide type for the
7786 -- synchronized type itself, with minimal semantic
7787 -- attributes, to catch other errors in some ACATS tests.
7789 pragma Assert (Serious_Errors_Detected /= 0);
7790 Make_Class_Wide_Type (T);
7791 C := Class_Wide_Type (T);
7792 Set_First_Entity (C, First_Entity (T));
7795 C := Class_Wide_Type
7796 (Corresponding_Record_Type (Entity (Prefix (N))));
7800 C := Class_Wide_Type (Entity (Prefix (N)));
7803 Set_Entity_With_Checks (N, C);
7804 Generate_Reference (C, N);
7808 -- Base attribute, not allowed in Ada 83
7810 elsif Attribute_Name (N) = Name_Base then
7811 if Ada_Version = Ada_83 and then Comes_From_Source (N) then
7813 ("(Ada 83) Base attribute not allowed in subtype mark", N);
7816 Find_Type (Prefix (N));
7817 Typ := Entity (Prefix (N));
7819 if Ada_Version >= Ada_95
7820 and then not Is_Scalar_Type (Typ)
7821 and then not Is_Generic_Type (Typ)
7824 ("prefix of Base attribute must be scalar type",
7827 elsif Warn_On_Redundant_Constructs
7828 and then Base_Type (Typ) = Typ
7830 Error_Msg_NE -- CODEFIX
7831 ("redundant attribute, & is its own base type?r?", N, Typ);
7834 T := Base_Type (Typ);
7836 -- Rewrite attribute reference with type itself (see similar
7837 -- processing in Analyze_Attribute, case Base). Preserve prefix
7838 -- if present, for other legality checks.
7840 if Nkind (Prefix (N)) = N_Expanded_Name then
7842 Make_Expanded_Name (Sloc (N),
7844 Prefix => New_Copy (Prefix (Prefix (N))),
7845 Selector_Name => New_Occurrence_Of (T, Sloc (N))));
7848 Rewrite (N, New_Occurrence_Of (T, Sloc (N)));
7855 elsif Attribute_Name (N) = Name_Stub_Type then
7857 -- This is handled in Analyze_Attribute
7861 -- All other attributes are invalid in a subtype mark
7864 Error_Msg_N ("invalid attribute in subtype mark", N);
7870 if Is_Entity_Name (N) then
7871 T_Name := Entity (N);
7873 Error_Msg_N ("subtype mark required in this context", N);
7874 Set_Etype (N, Any_Type);
7878 if T_Name = Any_Id or else Etype (N) = Any_Type then
7880 -- Undefined id. Make it into a valid type
7882 Set_Entity (N, Any_Type);
7884 elsif not Is_Type (T_Name)
7885 and then T_Name /= Standard_Void_Type
7887 Error_Msg_Sloc := Sloc (T_Name);
7888 Error_Msg_N ("subtype mark required in this context", N);
7889 Error_Msg_NE ("\\found & declared#", N, T_Name);
7890 Set_Entity (N, Any_Type);
7893 -- If the type is an incomplete type created to handle
7894 -- anonymous access components of a record type, then the
7895 -- incomplete type is the visible entity and subsequent
7896 -- references will point to it. Mark the original full
7897 -- type as referenced, to prevent spurious warnings.
7899 if Is_Incomplete_Type (T_Name)
7900 and then Present (Full_View (T_Name))
7901 and then not Comes_From_Source (T_Name)
7903 Set_Referenced (Full_View (T_Name));
7906 T_Name := Get_Full_View (T_Name);
7908 -- Ada 2005 (AI-251, AI-50217): Handle interfaces visible through
7909 -- limited-with clauses
7911 if From_Limited_With (T_Name)
7912 and then Is_Incomplete_Type (T_Name)
7913 and then Present (Non_Limited_View (T_Name))
7914 and then Is_Interface (Non_Limited_View (T_Name))
7916 T_Name := Non_Limited_View (T_Name);
7919 if In_Open_Scopes (T_Name) then
7920 if Ekind (Base_Type (T_Name)) = E_Task_Type then
7922 -- In Ada 2005, a task name can be used in an access
7923 -- definition within its own body. It cannot be used
7924 -- in the discriminant part of the task declaration,
7925 -- nor anywhere else in the declaration because entries
7926 -- cannot have access parameters.
7928 if Ada_Version >= Ada_2005
7929 and then Nkind (Parent (N)) = N_Access_Definition
7931 Set_Entity (N, T_Name);
7932 Set_Etype (N, T_Name);
7934 if Has_Completion (T_Name) then
7939 ("task type cannot be used as type mark " &
7940 "within its own declaration", N);
7945 ("task type cannot be used as type mark " &
7946 "within its own spec or body", N);
7949 elsif Ekind (Base_Type (T_Name)) = E_Protected_Type then
7951 -- In Ada 2005, a protected name can be used in an access
7952 -- definition within its own body.
7954 if Ada_Version >= Ada_2005
7955 and then Nkind (Parent (N)) = N_Access_Definition
7957 Set_Entity (N, T_Name);
7958 Set_Etype (N, T_Name);
7963 ("protected type cannot be used as type mark " &
7964 "within its own spec or body", N);
7968 Error_Msg_N ("type declaration cannot refer to itself", N);
7971 Set_Etype (N, Any_Type);
7972 Set_Entity (N, Any_Type);
7973 Set_Error_Posted (T_Name);
7977 Set_Entity (N, T_Name);
7978 Set_Etype (N, T_Name);
7982 if Present (Etype (N)) and then Comes_From_Source (N) then
7983 if Is_Fixed_Point_Type (Etype (N)) then
7984 Check_Restriction (No_Fixed_Point, N);
7985 elsif Is_Floating_Point_Type (Etype (N)) then
7986 Check_Restriction (No_Floating_Point, N);
7989 -- A Ghost type must appear in a specific context
7991 if Is_Ghost_Entity (Etype (N)) then
7992 Check_Ghost_Context (Etype (N), N);
7997 --------------------
7998 -- Has_Components --
7999 --------------------
8001 function Has_Components (Typ : Entity_Id) return Boolean is
8003 return Is_Record_Type (Typ)
8004 or else (Is_Private_Type (Typ) and then Has_Discriminants (Typ))
8005 or else (Is_Task_Type (Typ) and then Has_Discriminants (Typ))
8006 or else (Is_Incomplete_Type (Typ)
8007 and then From_Limited_With (Typ)
8008 and then Is_Record_Type (Available_View (Typ)));
8011 ------------------------------------
8012 -- Has_Implicit_Character_Literal --
8013 ------------------------------------
8015 function Has_Implicit_Character_Literal (N : Node_Id) return Boolean is
8017 Found : Boolean := False;
8018 P : constant Entity_Id := Entity (Prefix (N));
8019 Priv_Id : Entity_Id := Empty;
8022 if Ekind (P) = E_Package and then not In_Open_Scopes (P) then
8023 Priv_Id := First_Private_Entity (P);
8026 if P = Standard_Standard then
8027 Change_Selected_Component_To_Expanded_Name (N);
8028 Rewrite (N, Selector_Name (N));
8030 Set_Etype (Original_Node (N), Standard_Character);
8034 Id := First_Entity (P);
8035 while Present (Id) and then Id /= Priv_Id loop
8036 if Is_Standard_Character_Type (Id) and then Is_Base_Type (Id) then
8038 -- We replace the node with the literal itself, resolve as a
8039 -- character, and set the type correctly.
8042 Change_Selected_Component_To_Expanded_Name (N);
8043 Rewrite (N, Selector_Name (N));
8046 Set_Etype (Original_Node (N), Id);
8050 -- More than one type derived from Character in given scope.
8051 -- Collect all possible interpretations.
8053 Add_One_Interp (N, Id, Id);
8061 end Has_Implicit_Character_Literal;
8063 ----------------------
8064 -- Has_Private_With --
8065 ----------------------
8067 function Has_Private_With (E : Entity_Id) return Boolean is
8068 Comp_Unit : constant Node_Id := Cunit (Current_Sem_Unit);
8072 Item := First (Context_Items (Comp_Unit));
8073 while Present (Item) loop
8074 if Nkind (Item) = N_With_Clause
8075 and then Private_Present (Item)
8076 and then Entity (Name (Item)) = E
8085 end Has_Private_With;
8087 ---------------------------
8088 -- Has_Implicit_Operator --
8089 ---------------------------
8091 function Has_Implicit_Operator (N : Node_Id) return Boolean is
8092 Op_Id : constant Name_Id := Chars (Selector_Name (N));
8093 P : constant Entity_Id := Entity (Prefix (N));
8095 Priv_Id : Entity_Id := Empty;
8097 procedure Add_Implicit_Operator
8099 Op_Type : Entity_Id := Empty);
8100 -- Add implicit interpretation to node N, using the type for which a
8101 -- predefined operator exists. If the operator yields a boolean type,
8102 -- the Operand_Type is implicitly referenced by the operator, and a
8103 -- reference to it must be generated.
8105 ---------------------------
8106 -- Add_Implicit_Operator --
8107 ---------------------------
8109 procedure Add_Implicit_Operator
8111 Op_Type : Entity_Id := Empty)
8113 Predef_Op : Entity_Id;
8116 Predef_Op := Current_Entity (Selector_Name (N));
8117 while Present (Predef_Op)
8118 and then Scope (Predef_Op) /= Standard_Standard
8120 Predef_Op := Homonym (Predef_Op);
8123 if Nkind (N) = N_Selected_Component then
8124 Change_Selected_Component_To_Expanded_Name (N);
8127 -- If the context is an unanalyzed function call, determine whether
8128 -- a binary or unary interpretation is required.
8130 if Nkind (Parent (N)) = N_Indexed_Component then
8132 Is_Binary_Call : constant Boolean :=
8134 (Next (First (Expressions (Parent (N)))));
8135 Is_Binary_Op : constant Boolean :=
8137 (Predef_Op) /= Last_Entity (Predef_Op);
8138 Predef_Op2 : constant Entity_Id := Homonym (Predef_Op);
8141 if Is_Binary_Call then
8142 if Is_Binary_Op then
8143 Add_One_Interp (N, Predef_Op, T);
8145 Add_One_Interp (N, Predef_Op2, T);
8149 if not Is_Binary_Op then
8150 Add_One_Interp (N, Predef_Op, T);
8152 Add_One_Interp (N, Predef_Op2, T);
8158 Add_One_Interp (N, Predef_Op, T);
8160 -- For operators with unary and binary interpretations, if
8161 -- context is not a call, add both
8163 if Present (Homonym (Predef_Op)) then
8164 Add_One_Interp (N, Homonym (Predef_Op), T);
8168 -- The node is a reference to a predefined operator, and
8169 -- an implicit reference to the type of its operands.
8171 if Present (Op_Type) then
8172 Generate_Operator_Reference (N, Op_Type);
8174 Generate_Operator_Reference (N, T);
8176 end Add_Implicit_Operator;
8178 -- Start of processing for Has_Implicit_Operator
8181 if Ekind (P) = E_Package and then not In_Open_Scopes (P) then
8182 Priv_Id := First_Private_Entity (P);
8185 Id := First_Entity (P);
8189 -- Boolean operators: an implicit declaration exists if the scope
8190 -- contains a declaration for a derived Boolean type, or for an
8191 -- array of Boolean type.
8198 while Id /= Priv_Id loop
8199 if Valid_Boolean_Arg (Id) and then Is_Base_Type (Id) then
8200 Add_Implicit_Operator (Id);
8207 -- Equality: look for any non-limited type (result is Boolean)
8212 while Id /= Priv_Id loop
8214 and then not Is_Limited_Type (Id)
8215 and then Is_Base_Type (Id)
8217 Add_Implicit_Operator (Standard_Boolean, Id);
8224 -- Comparison operators: scalar type, or array of scalar
8231 while Id /= Priv_Id loop
8232 if (Is_Scalar_Type (Id)
8233 or else (Is_Array_Type (Id)
8234 and then Is_Scalar_Type (Component_Type (Id))))
8235 and then Is_Base_Type (Id)
8237 Add_Implicit_Operator (Standard_Boolean, Id);
8244 -- Arithmetic operators: any numeric type
8255 while Id /= Priv_Id loop
8256 if Is_Numeric_Type (Id) and then Is_Base_Type (Id) then
8257 Add_Implicit_Operator (Id);
8264 -- Concatenation: any one-dimensional array type
8266 when Name_Op_Concat =>
8267 while Id /= Priv_Id loop
8268 if Is_Array_Type (Id)
8269 and then Number_Dimensions (Id) = 1
8270 and then Is_Base_Type (Id)
8272 Add_Implicit_Operator (Id);
8279 -- What is the others condition here? Should we be using a
8280 -- subtype of Name_Id that would restrict to operators ???
8286 -- If we fall through, then we do not have an implicit operator
8289 end Has_Implicit_Operator;
8291 -----------------------------------
8292 -- Has_Loop_In_Inner_Open_Scopes --
8293 -----------------------------------
8295 function Has_Loop_In_Inner_Open_Scopes (S : Entity_Id) return Boolean is
8297 -- Several scope stacks are maintained by Scope_Stack. The base of the
8298 -- currently active scope stack is denoted by the Is_Active_Stack_Base
8299 -- flag in the scope stack entry. Note that the scope stacks used to
8300 -- simply be delimited implicitly by the presence of Standard_Standard
8301 -- at their base, but there now are cases where this is not sufficient
8302 -- because Standard_Standard actually may appear in the middle of the
8303 -- active set of scopes.
8305 for J in reverse 0 .. Scope_Stack.Last loop
8307 -- S was reached without seing a loop scope first
8309 if Scope_Stack.Table (J).Entity = S then
8312 -- S was not yet reached, so it contains at least one inner loop
8314 elsif Ekind (Scope_Stack.Table (J).Entity) = E_Loop then
8318 -- Check Is_Active_Stack_Base to tell us when to stop, as there are
8319 -- cases where Standard_Standard appears in the middle of the active
8320 -- set of scopes. This affects the declaration and overriding of
8321 -- private inherited operations in instantiations of generic child
8324 pragma Assert (not Scope_Stack.Table (J).Is_Active_Stack_Base);
8327 raise Program_Error; -- unreachable
8328 end Has_Loop_In_Inner_Open_Scopes;
8330 --------------------
8331 -- In_Open_Scopes --
8332 --------------------
8334 function In_Open_Scopes (S : Entity_Id) return Boolean is
8336 -- Several scope stacks are maintained by Scope_Stack. The base of the
8337 -- currently active scope stack is denoted by the Is_Active_Stack_Base
8338 -- flag in the scope stack entry. Note that the scope stacks used to
8339 -- simply be delimited implicitly by the presence of Standard_Standard
8340 -- at their base, but there now are cases where this is not sufficient
8341 -- because Standard_Standard actually may appear in the middle of the
8342 -- active set of scopes.
8344 for J in reverse 0 .. Scope_Stack.Last loop
8345 if Scope_Stack.Table (J).Entity = S then
8349 -- Check Is_Active_Stack_Base to tell us when to stop, as there are
8350 -- cases where Standard_Standard appears in the middle of the active
8351 -- set of scopes. This affects the declaration and overriding of
8352 -- private inherited operations in instantiations of generic child
8355 exit when Scope_Stack.Table (J).Is_Active_Stack_Base;
8361 -----------------------------
8362 -- Inherit_Renamed_Profile --
8363 -----------------------------
8365 procedure Inherit_Renamed_Profile (New_S : Entity_Id; Old_S : Entity_Id) is
8372 if Ekind (Old_S) = E_Operator then
8373 New_F := First_Formal (New_S);
8375 while Present (New_F) loop
8376 Set_Etype (New_F, Base_Type (Etype (New_F)));
8377 Next_Formal (New_F);
8380 Set_Etype (New_S, Base_Type (Etype (New_S)));
8383 New_F := First_Formal (New_S);
8384 Old_F := First_Formal (Old_S);
8386 while Present (New_F) loop
8387 New_T := Etype (New_F);
8388 Old_T := Etype (Old_F);
8390 -- If the new type is a renaming of the old one, as is the case
8391 -- for actuals in instances, retain its name, to simplify later
8394 if Nkind (Parent (New_T)) = N_Subtype_Declaration
8395 and then Is_Entity_Name (Subtype_Indication (Parent (New_T)))
8396 and then Entity (Subtype_Indication (Parent (New_T))) = Old_T
8400 Set_Etype (New_F, Old_T);
8403 Next_Formal (New_F);
8404 Next_Formal (Old_F);
8407 pragma Assert (No (Old_F));
8409 if Ekind_In (Old_S, E_Function, E_Enumeration_Literal) then
8410 Set_Etype (New_S, Etype (Old_S));
8413 end Inherit_Renamed_Profile;
8419 procedure Initialize is
8424 -------------------------
8425 -- Install_Use_Clauses --
8426 -------------------------
8428 procedure Install_Use_Clauses
8430 Force_Installation : Boolean := False)
8436 while Present (U) loop
8438 -- Case of USE package
8440 if Nkind (U) = N_Use_Package_Clause then
8441 Use_One_Package (U, Name (U), True);
8446 Use_One_Type (Subtype_Mark (U), Force => Force_Installation);
8450 Next_Use_Clause (U);
8452 end Install_Use_Clauses;
8454 ----------------------
8455 -- Mark_Use_Clauses --
8456 ----------------------
8458 procedure Mark_Use_Clauses (Id : Node_Or_Entity_Id) is
8459 procedure Mark_Parameters (Call : Entity_Id);
8460 -- Perform use_type_clause marking for all parameters in a subprogram
8461 -- or operator call.
8463 procedure Mark_Use_Package (Pak : Entity_Id);
8464 -- Move up the Prev_Use_Clause chain for packages denoted by Pak -
8465 -- marking each clause in the chain as effective in the process.
8467 procedure Mark_Use_Type (E : Entity_Id);
8468 -- Similar to Do_Use_Package_Marking except we move up the
8469 -- Prev_Use_Clause chain for the type denoted by E.
8471 ---------------------
8472 -- Mark_Parameters --
8473 ---------------------
8475 procedure Mark_Parameters (Call : Entity_Id) is
8479 -- Move through all of the formals
8481 Curr := First_Formal (Call);
8482 while Present (Curr) loop
8483 Mark_Use_Type (Curr);
8488 -- Handle the return type
8490 Mark_Use_Type (Call);
8491 end Mark_Parameters;
8493 ----------------------
8494 -- Mark_Use_Package --
8495 ----------------------
8497 procedure Mark_Use_Package (Pak : Entity_Id) is
8501 -- Ignore cases where the scope of the type is not a package (e.g.
8502 -- Standard_Standard).
8504 if Ekind (Pak) /= E_Package then
8508 Curr := Current_Use_Clause (Pak);
8509 while Present (Curr)
8510 and then not Is_Effective_Use_Clause (Curr)
8512 -- We need to mark the previous use clauses as effective, but
8513 -- each use clause may in turn render other use_package_clauses
8514 -- effective. Additionally, it is possible to have a parent
8515 -- package renamed as a child of itself so we must check the
8516 -- prefix entity is not the same as the package we are marking.
8518 if Nkind (Name (Curr)) /= N_Identifier
8519 and then Present (Prefix (Name (Curr)))
8520 and then Entity (Prefix (Name (Curr))) /= Pak
8522 Mark_Use_Package (Entity (Prefix (Name (Curr))));
8524 -- It is also possible to have a child package without a prefix
8525 -- that relies on a previous use_package_clause.
8527 elsif Nkind (Name (Curr)) = N_Identifier
8528 and then Is_Child_Unit (Entity (Name (Curr)))
8530 Mark_Use_Package (Scope (Entity (Name (Curr))));
8533 -- Mark the use_package_clause as effective and move up the chain
8535 Set_Is_Effective_Use_Clause (Curr);
8537 Curr := Prev_Use_Clause (Curr);
8539 end Mark_Use_Package;
8545 procedure Mark_Use_Type (E : Entity_Id) is
8550 -- Ignore void types and unresolved string literals and primitives
8552 if Nkind (E) = N_String_Literal
8553 or else Nkind (Etype (E)) not in N_Entity
8554 or else not Is_Type (Etype (E))
8559 -- Primitives with class-wide operands might additionally render
8560 -- their base type's use_clauses effective - so do a recursive check
8563 Base := Base_Type (Etype (E));
8565 if Ekind (Base) = E_Class_Wide_Type then
8566 Mark_Use_Type (Base);
8569 -- The package containing the type or operator function being used
8570 -- may be in use as well, so mark any use_package_clauses for it as
8571 -- effective. There are also additional sanity checks performed here
8572 -- for ignoring previous errors.
8574 Mark_Use_Package (Scope (Base));
8576 if Nkind (E) in N_Op
8577 and then Present (Entity (E))
8578 and then Present (Scope (Entity (E)))
8580 Mark_Use_Package (Scope (Entity (E)));
8583 Curr := Current_Use_Clause (Base);
8584 while Present (Curr)
8585 and then not Is_Effective_Use_Clause (Curr)
8587 -- Current use_type_clause may render other use_package_clauses
8590 if Nkind (Subtype_Mark (Curr)) /= N_Identifier
8591 and then Present (Prefix (Subtype_Mark (Curr)))
8593 Mark_Use_Package (Entity (Prefix (Subtype_Mark (Curr))));
8596 -- Mark the use_type_clause as effective and move up the chain
8598 Set_Is_Effective_Use_Clause (Curr);
8600 Curr := Prev_Use_Clause (Curr);
8604 -- Start of processing for Mark_Use_Clauses
8607 -- Use clauses in and of themselves do not count as a "use" of a
8610 if Nkind_In (Parent (Id), N_Use_Package_Clause, N_Use_Type_Clause) then
8616 if Nkind (Id) in N_Entity then
8618 -- Mark the entity's package
8620 if Is_Potentially_Use_Visible (Id) then
8621 Mark_Use_Package (Scope (Id));
8624 -- Mark enumeration literals
8626 if Ekind (Id) = E_Enumeration_Literal then
8631 elsif (Ekind (Id) in Overloadable_Kind
8632 or else Ekind_In (Id, E_Generic_Function,
8633 E_Generic_Procedure))
8634 and then (Is_Potentially_Use_Visible (Id)
8635 or else Is_Intrinsic_Subprogram (Id)
8636 or else (Ekind_In (Id, E_Function, E_Procedure)
8637 and then Is_Generic_Actual_Subprogram (Id)))
8639 Mark_Parameters (Id);
8647 if Nkind (Id) in N_Op then
8649 -- At this point the left operand may not be resolved if we are
8650 -- encountering multiple operators next to eachother in an
8653 if Nkind (Id) in N_Binary_Op
8654 and then not (Nkind (Left_Opnd (Id)) in N_Op)
8656 Mark_Use_Type (Left_Opnd (Id));
8659 Mark_Use_Type (Right_Opnd (Id));
8662 -- Mark entity identifiers
8664 elsif Nkind (Id) in N_Has_Entity
8665 and then (Is_Potentially_Use_Visible (Entity (Id))
8666 or else (Is_Generic_Instance (Entity (Id))
8667 and then Is_Immediately_Visible (Entity (Id))))
8669 -- Ignore fully qualified names as they do not count as a "use" of
8672 if Nkind_In (Id, N_Identifier, N_Operator_Symbol)
8673 or else (Present (Prefix (Id))
8674 and then Scope (Entity (Id)) /= Entity (Prefix (Id)))
8676 Mark_Use_Clauses (Entity (Id));
8680 end Mark_Use_Clauses;
8682 --------------------------------
8683 -- Most_Descendant_Use_Clause --
8684 --------------------------------
8686 function Most_Descendant_Use_Clause
8687 (Clause1 : Entity_Id;
8688 Clause2 : Entity_Id) return Entity_Id
8694 if Clause1 = Clause2 then
8698 -- We determine which one is the most descendant by the scope distance
8699 -- to the ultimate parent unit.
8701 Scope1 := Entity_Of_Unit (Unit (Parent (Clause1)));
8702 Scope2 := Entity_Of_Unit (Unit (Parent (Clause2)));
8703 while Scope1 /= Standard_Standard
8704 and then Scope2 /= Standard_Standard
8706 Scope1 := Scope (Scope1);
8707 Scope2 := Scope (Scope2);
8709 if not Present (Scope1) then
8711 elsif not Present (Scope2) then
8716 if Scope1 = Standard_Standard then
8721 end Most_Descendant_Use_Clause;
8727 procedure Pop_Scope is
8728 SST : Scope_Stack_Entry renames Scope_Stack.Table (Scope_Stack.Last);
8729 S : constant Entity_Id := SST.Entity;
8732 if Debug_Flag_E then
8736 -- Set Default_Storage_Pool field of the library unit if necessary
8738 if Is_Package_Or_Generic_Package (S)
8740 Nkind (Parent (Unit_Declaration_Node (S))) = N_Compilation_Unit
8743 Aux : constant Node_Id :=
8744 Aux_Decls_Node (Parent (Unit_Declaration_Node (S)));
8746 if No (Default_Storage_Pool (Aux)) then
8747 Set_Default_Storage_Pool (Aux, Default_Pool);
8752 Scope_Suppress := SST.Save_Scope_Suppress;
8753 Local_Suppress_Stack_Top := SST.Save_Local_Suppress_Stack_Top;
8754 Check_Policy_List := SST.Save_Check_Policy_List;
8755 Default_Pool := SST.Save_Default_Storage_Pool;
8756 No_Tagged_Streams := SST.Save_No_Tagged_Streams;
8757 SPARK_Mode := SST.Save_SPARK_Mode;
8758 SPARK_Mode_Pragma := SST.Save_SPARK_Mode_Pragma;
8759 Default_SSO := SST.Save_Default_SSO;
8760 Uneval_Old := SST.Save_Uneval_Old;
8762 if Debug_Flag_W then
8763 Write_Str ("<-- exiting scope: ");
8764 Write_Name (Chars (Current_Scope));
8765 Write_Str (", Depth=");
8766 Write_Int (Int (Scope_Stack.Last));
8770 End_Use_Clauses (SST.First_Use_Clause);
8772 -- If the actions to be wrapped are still there they will get lost
8773 -- causing incomplete code to be generated. It is better to abort in
8774 -- this case (and we do the abort even with assertions off since the
8775 -- penalty is incorrect code generation).
8777 if SST.Actions_To_Be_Wrapped /= Scope_Actions'(others => No_List) then
8778 raise Program_Error;
8781 -- Free last subprogram name if allocated, and pop scope
8783 Free (SST.Last_Subprogram_Name);
8784 Scope_Stack.Decrement_Last;
8791 procedure Push_Scope (S : Entity_Id) is
8792 E : constant Entity_Id := Scope (S);
8795 if Ekind (S) = E_Void then
8798 -- Set scope depth if not a non-concurrent type, and we have not yet set
8799 -- the scope depth. This means that we have the first occurrence of the
8800 -- scope, and this is where the depth is set.
8802 elsif (not Is_Type (S) or else Is_Concurrent_Type (S))
8803 and then not Scope_Depth_Set (S)
8805 if S = Standard_Standard then
8806 Set_Scope_Depth_Value (S, Uint_0);
8808 elsif Is_Child_Unit (S) then
8809 Set_Scope_Depth_Value (S, Uint_1);
8811 elsif not Is_Record_Type (Current_Scope) then
8812 if Ekind (S) = E_Loop then
8813 Set_Scope_Depth_Value (S, Scope_Depth (Current_Scope));
8815 Set_Scope_Depth_Value (S, Scope_Depth (Current_Scope) + 1);
8820 Scope_Stack.Increment_Last;
8823 SST : Scope_Stack_Entry renames Scope_Stack.Table (Scope_Stack.Last);
8827 SST.Save_Scope_Suppress := Scope_Suppress;
8828 SST.Save_Local_Suppress_Stack_Top := Local_Suppress_Stack_Top;
8829 SST.Save_Check_Policy_List := Check_Policy_List;
8830 SST.Save_Default_Storage_Pool := Default_Pool;
8831 SST.Save_No_Tagged_Streams := No_Tagged_Streams;
8832 SST.Save_SPARK_Mode := SPARK_Mode;
8833 SST.Save_SPARK_Mode_Pragma := SPARK_Mode_Pragma;
8834 SST.Save_Default_SSO := Default_SSO;
8835 SST.Save_Uneval_Old := Uneval_Old;
8837 -- Each new scope pushed onto the scope stack inherits the component
8838 -- alignment of the previous scope. This emulates the "visibility"
8839 -- semantics of pragma Component_Alignment.
8841 if Scope_Stack.Last > Scope_Stack.First then
8842 SST.Component_Alignment_Default :=
8844 (Scope_Stack.Last - 1).Component_Alignment_Default;
8846 -- Otherwise, this is the first scope being pushed on the scope
8847 -- stack. Inherit the component alignment from the configuration
8848 -- form of pragma Component_Alignment (if any).
8851 SST.Component_Alignment_Default :=
8852 Configuration_Component_Alignment;
8855 SST.Last_Subprogram_Name := null;
8856 SST.Is_Transient := False;
8857 SST.Node_To_Be_Wrapped := Empty;
8858 SST.Pending_Freeze_Actions := No_List;
8859 SST.Actions_To_Be_Wrapped := (others => No_List);
8860 SST.First_Use_Clause := Empty;
8861 SST.Is_Active_Stack_Base := False;
8862 SST.Previous_Visibility := False;
8863 SST.Locked_Shared_Objects := No_Elist;
8866 if Debug_Flag_W then
8867 Write_Str ("--> new scope: ");
8868 Write_Name (Chars (Current_Scope));
8869 Write_Str (", Id=");
8870 Write_Int (Int (Current_Scope));
8871 Write_Str (", Depth=");
8872 Write_Int (Int (Scope_Stack.Last));
8876 -- Deal with copying flags from the previous scope to this one. This is
8877 -- not necessary if either scope is standard, or if the new scope is a
8880 if S /= Standard_Standard
8881 and then Scope (S) /= Standard_Standard
8882 and then not Is_Child_Unit (S)
8884 if Nkind (E) not in N_Entity then
8888 -- Copy categorization flags from Scope (S) to S, this is not done
8889 -- when Scope (S) is Standard_Standard since propagation is from
8890 -- library unit entity inwards. Copy other relevant attributes as
8891 -- well (Discard_Names in particular).
8893 -- We only propagate inwards for library level entities,
8894 -- inner level subprograms do not inherit the categorization.
8896 if Is_Library_Level_Entity (S) then
8897 Set_Is_Preelaborated (S, Is_Preelaborated (E));
8898 Set_Is_Shared_Passive (S, Is_Shared_Passive (E));
8899 Set_Discard_Names (S, Discard_Names (E));
8900 Set_Suppress_Value_Tracking_On_Call
8901 (S, Suppress_Value_Tracking_On_Call (E));
8902 Set_Categorization_From_Scope (E => S, Scop => E);
8906 if Is_Child_Unit (S)
8907 and then Present (E)
8908 and then Is_Package_Or_Generic_Package (E)
8910 Nkind (Parent (Unit_Declaration_Node (E))) = N_Compilation_Unit
8913 Aux : constant Node_Id :=
8914 Aux_Decls_Node (Parent (Unit_Declaration_Node (E)));
8916 if Present (Default_Storage_Pool (Aux)) then
8917 Default_Pool := Default_Storage_Pool (Aux);
8923 ---------------------
8924 -- Premature_Usage --
8925 ---------------------
8927 procedure Premature_Usage (N : Node_Id) is
8928 Kind : constant Node_Kind := Nkind (Parent (Entity (N)));
8929 E : Entity_Id := Entity (N);
8932 -- Within an instance, the analysis of the actual for a formal object
8933 -- does not see the name of the object itself. This is significant only
8934 -- if the object is an aggregate, where its analysis does not do any
8935 -- name resolution on component associations. (see 4717-008). In such a
8936 -- case, look for the visible homonym on the chain.
8938 if In_Instance and then Present (Homonym (E)) then
8940 while Present (E) and then not In_Open_Scopes (Scope (E)) loop
8946 Set_Etype (N, Etype (E));
8951 if Kind = N_Component_Declaration then
8953 ("component&! cannot be used before end of record declaration", N);
8955 elsif Kind = N_Parameter_Specification then
8957 ("formal parameter&! cannot be used before end of specification",
8960 elsif Kind = N_Discriminant_Specification then
8962 ("discriminant&! cannot be used before end of discriminant part",
8965 elsif Kind = N_Procedure_Specification
8966 or else Kind = N_Function_Specification
8969 ("subprogram&! cannot be used before end of its declaration",
8972 elsif Kind = N_Full_Type_Declaration then
8974 ("type& cannot be used before end of its declaration!", N);
8978 ("object& cannot be used before end of its declaration!", N);
8980 -- If the premature reference appears as the expression in its own
8981 -- declaration, rewrite it to prevent compiler loops in subsequent
8982 -- uses of this mangled declaration in address clauses.
8984 if Nkind (Parent (N)) = N_Object_Declaration then
8985 Set_Entity (N, Any_Id);
8988 end Premature_Usage;
8990 ------------------------
8991 -- Present_System_Aux --
8992 ------------------------
8994 function Present_System_Aux (N : Node_Id := Empty) return Boolean is
8996 Aux_Name : Unit_Name_Type;
8997 Unum : Unit_Number_Type;
9002 function Find_System (C_Unit : Node_Id) return Entity_Id;
9003 -- Scan context clause of compilation unit to find with_clause
9010 function Find_System (C_Unit : Node_Id) return Entity_Id is
9011 With_Clause : Node_Id;
9014 With_Clause := First (Context_Items (C_Unit));
9015 while Present (With_Clause) loop
9016 if (Nkind (With_Clause) = N_With_Clause
9017 and then Chars (Name (With_Clause)) = Name_System)
9018 and then Comes_From_Source (With_Clause)
9029 -- Start of processing for Present_System_Aux
9032 -- The child unit may have been loaded and analyzed already
9034 if Present (System_Aux_Id) then
9037 -- If no previous pragma for System.Aux, nothing to load
9039 elsif No (System_Extend_Unit) then
9042 -- Use the unit name given in the pragma to retrieve the unit.
9043 -- Verify that System itself appears in the context clause of the
9044 -- current compilation. If System is not present, an error will
9045 -- have been reported already.
9048 With_Sys := Find_System (Cunit (Current_Sem_Unit));
9050 The_Unit := Unit (Cunit (Current_Sem_Unit));
9054 (Nkind (The_Unit) = N_Package_Body
9055 or else (Nkind (The_Unit) = N_Subprogram_Body
9056 and then not Acts_As_Spec (Cunit (Current_Sem_Unit))))
9058 With_Sys := Find_System (Library_Unit (Cunit (Current_Sem_Unit)));
9061 if No (With_Sys) and then Present (N) then
9063 -- If we are compiling a subunit, we need to examine its
9064 -- context as well (Current_Sem_Unit is the parent unit);
9066 The_Unit := Parent (N);
9067 while Nkind (The_Unit) /= N_Compilation_Unit loop
9068 The_Unit := Parent (The_Unit);
9071 if Nkind (Unit (The_Unit)) = N_Subunit then
9072 With_Sys := Find_System (The_Unit);
9076 if No (With_Sys) then
9080 Loc := Sloc (With_Sys);
9081 Get_Name_String (Chars (Expression (System_Extend_Unit)));
9082 Name_Buffer (8 .. Name_Len + 7) := Name_Buffer (1 .. Name_Len);
9083 Name_Buffer (1 .. 7) := "system.";
9084 Name_Buffer (Name_Len + 8) := '%';
9085 Name_Buffer (Name_Len + 9) := 's';
9086 Name_Len := Name_Len + 9;
9087 Aux_Name := Name_Find;
9091 (Load_Name => Aux_Name,
9094 Error_Node => With_Sys);
9096 if Unum /= No_Unit then
9097 Semantics (Cunit (Unum));
9099 Defining_Entity (Specification (Unit (Cunit (Unum))));
9102 Make_With_Clause (Loc,
9104 Make_Expanded_Name (Loc,
9105 Chars => Chars (System_Aux_Id),
9107 New_Occurrence_Of (Scope (System_Aux_Id), Loc),
9108 Selector_Name => New_Occurrence_Of (System_Aux_Id, Loc)));
9110 Set_Entity (Name (Withn), System_Aux_Id);
9112 Set_Corresponding_Spec (Withn, System_Aux_Id);
9113 Set_First_Name (Withn);
9114 Set_Implicit_With (Withn);
9115 Set_Library_Unit (Withn, Cunit (Unum));
9117 Insert_After (With_Sys, Withn);
9118 Mark_Rewrite_Insertion (Withn);
9119 Set_Context_Installed (Withn);
9123 -- Here if unit load failed
9126 Error_Msg_Name_1 := Name_System;
9127 Error_Msg_Name_2 := Chars (Expression (System_Extend_Unit));
9129 ("extension package `%.%` does not exist",
9130 Opt.System_Extend_Unit);
9134 end Present_System_Aux;
9136 -------------------------
9137 -- Restore_Scope_Stack --
9138 -------------------------
9140 procedure Restore_Scope_Stack
9142 Handle_Use : Boolean := True)
9144 SS_Last : constant Int := Scope_Stack.Last;
9148 -- Restore visibility of previous scope stack, if any, using the list
9149 -- we saved (we use Remove, since this list will not be used again).
9152 Elmt := Last_Elmt (List);
9153 exit when Elmt = No_Elmt;
9154 Set_Is_Immediately_Visible (Node (Elmt));
9155 Remove_Last_Elmt (List);
9158 -- Restore use clauses
9160 if SS_Last >= Scope_Stack.First
9161 and then Scope_Stack.Table (SS_Last).Entity /= Standard_Standard
9165 (Scope_Stack.Table (SS_Last).First_Use_Clause,
9166 Force_Installation => True);
9168 end Restore_Scope_Stack;
9170 ----------------------
9171 -- Save_Scope_Stack --
9172 ----------------------
9174 -- Save_Scope_Stack/Restore_Scope_Stack were originally designed to avoid
9175 -- consuming any memory. That is, Save_Scope_Stack took care of removing
9176 -- from immediate visibility entities and Restore_Scope_Stack took care
9177 -- of restoring their visibility analyzing the context of each entity. The
9178 -- problem of such approach is that it was fragile and caused unexpected
9179 -- visibility problems, and indeed one test was found where there was a
9182 -- Furthermore, the following experiment was carried out:
9184 -- - Save_Scope_Stack was modified to store in an Elist1 all those
9185 -- entities whose attribute Is_Immediately_Visible is modified
9186 -- from True to False.
9188 -- - Restore_Scope_Stack was modified to store in another Elist2
9189 -- all the entities whose attribute Is_Immediately_Visible is
9190 -- modified from False to True.
9192 -- - Extra code was added to verify that all the elements of Elist1
9193 -- are found in Elist2
9195 -- This test shows that there may be more occurrences of this problem which
9196 -- have not yet been detected. As a result, we replaced that approach by
9197 -- the current one in which Save_Scope_Stack returns the list of entities
9198 -- whose visibility is changed, and that list is passed to Restore_Scope_
9199 -- Stack to undo that change. This approach is simpler and safer, although
9200 -- it consumes more memory.
9202 function Save_Scope_Stack (Handle_Use : Boolean := True) return Elist_Id is
9203 Result : constant Elist_Id := New_Elmt_List;
9206 SS_Last : constant Int := Scope_Stack.Last;
9208 procedure Remove_From_Visibility (E : Entity_Id);
9209 -- If E is immediately visible then append it to the result and remove
9210 -- it temporarily from visibility.
9212 ----------------------------
9213 -- Remove_From_Visibility --
9214 ----------------------------
9216 procedure Remove_From_Visibility (E : Entity_Id) is
9218 if Is_Immediately_Visible (E) then
9219 Append_Elmt (E, Result);
9220 Set_Is_Immediately_Visible (E, False);
9222 end Remove_From_Visibility;
9224 -- Start of processing for Save_Scope_Stack
9227 if SS_Last >= Scope_Stack.First
9228 and then Scope_Stack.Table (SS_Last).Entity /= Standard_Standard
9231 End_Use_Clauses (Scope_Stack.Table (SS_Last).First_Use_Clause);
9234 -- If the call is from within a compilation unit, as when called from
9235 -- Rtsfind, make current entries in scope stack invisible while we
9236 -- analyze the new unit.
9238 for J in reverse 0 .. SS_Last loop
9239 exit when Scope_Stack.Table (J).Entity = Standard_Standard
9240 or else No (Scope_Stack.Table (J).Entity);
9242 S := Scope_Stack.Table (J).Entity;
9244 Remove_From_Visibility (S);
9246 E := First_Entity (S);
9247 while Present (E) loop
9248 Remove_From_Visibility (E);
9256 end Save_Scope_Stack;
9262 procedure Set_Use (L : List_Id) is
9268 while Present (Decl) loop
9269 if Nkind (Decl) = N_Use_Package_Clause then
9270 Chain_Use_Clause (Decl);
9271 Use_One_Package (Decl, Name (Decl));
9273 elsif Nkind (Decl) = N_Use_Type_Clause then
9274 Chain_Use_Clause (Decl);
9275 Use_One_Type (Subtype_Mark (Decl));
9284 -----------------------------
9285 -- Update_Use_Clause_Chain --
9286 -----------------------------
9288 procedure Update_Use_Clause_Chain is
9290 procedure Update_Chain_In_Scope (Level : Int);
9291 -- Iterate through one level in the scope stack verifying each use-type
9292 -- clause within said level is used then reset the Current_Use_Clause
9293 -- to a redundant use clause outside of the current ending scope if such
9296 ---------------------------
9297 -- Update_Chain_In_Scope --
9298 ---------------------------
9300 procedure Update_Chain_In_Scope (Level : Int) is
9305 -- Loop through all use clauses within the scope dictated by Level
9307 Curr := Scope_Stack.Table (Level).First_Use_Clause;
9308 while Present (Curr) loop
9310 -- Retrieve the subtype mark or name within the current current
9313 if Nkind (Curr) = N_Use_Type_Clause then
9314 N := Subtype_Mark (Curr);
9319 -- If warnings for unreferenced entities are enabled and the
9320 -- current use clause has not been marked effective.
9322 if Check_Unreferenced
9323 and then Comes_From_Source (Curr)
9324 and then not Is_Effective_Use_Clause (Curr)
9325 and then not In_Instance
9326 and then not In_Inlined_Body
9328 -- We are dealing with a potentially unused use_package_clause
9330 if Nkind (Curr) = N_Use_Package_Clause then
9332 -- Renamings and formal subprograms may cause the associated
9333 -- node to be marked as effective instead of the original.
9335 if not (Present (Associated_Node (N))
9338 (Associated_Node (N)))
9339 and then Is_Effective_Use_Clause
9341 (Associated_Node (N))))
9343 Error_Msg_Node_1 := Entity (N);
9345 ("use clause for package & has no effect?u?",
9349 -- We are dealing with an unused use_type_clause
9352 Error_Msg_Node_1 := Etype (N);
9354 ("use clause for } has no effect?u?", Curr, Etype (N));
9358 -- Verify that we haven't already processed a redundant
9359 -- use_type_clause within the same scope before we move the
9360 -- current use clause up to a previous one for type T.
9362 if Present (Prev_Use_Clause (Curr)) then
9363 Set_Current_Use_Clause (Entity (N), Prev_Use_Clause (Curr));
9366 Next_Use_Clause (Curr);
9368 end Update_Chain_In_Scope;
9370 -- Start of processing for Update_Use_Clause_Chain
9373 Update_Chain_In_Scope (Scope_Stack.Last);
9375 -- Deal with use clauses within the context area if the current
9376 -- scope is a compilation unit.
9378 if Is_Compilation_Unit (Current_Scope)
9379 and then Sloc (Scope_Stack.Table
9380 (Scope_Stack.Last - 1).Entity) = Standard_Location
9382 Update_Chain_In_Scope (Scope_Stack.Last - 1);
9384 end Update_Use_Clause_Chain;
9386 ---------------------
9387 -- Use_One_Package --
9388 ---------------------
9390 procedure Use_One_Package
9392 Pack_Name : Entity_Id := Empty;
9393 Force : Boolean := False)
9395 procedure Note_Redundant_Use (Clause : Node_Id);
9396 -- Mark the name in a use clause as redundant if the corresponding
9397 -- entity is already use-visible. Emit a warning if the use clause comes
9398 -- from source and the proper warnings are enabled.
9400 ------------------------
9401 -- Note_Redundant_Use --
9402 ------------------------
9404 procedure Note_Redundant_Use (Clause : Node_Id) is
9405 Decl : constant Node_Id := Parent (Clause);
9406 Pack_Name : constant Entity_Id := Entity (Clause);
9408 Cur_Use : Node_Id := Current_Use_Clause (Pack_Name);
9409 Prev_Use : Node_Id := Empty;
9410 Redundant : Node_Id := Empty;
9411 -- The Use_Clause which is actually redundant. In the simplest case
9412 -- it is Pack itself, but when we compile a body we install its
9413 -- context before that of its spec, in which case it is the
9414 -- use_clause in the spec that will appear to be redundant, and we
9415 -- want the warning to be placed on the body. Similar complications
9416 -- appear when the redundancy is between a child unit and one of its
9420 -- Could be renamed...
9422 if No (Cur_Use) then
9423 Cur_Use := Current_Use_Clause (Renamed_Entity (Pack_Name));
9426 Set_Redundant_Use (Clause, True);
9428 if not Comes_From_Source (Clause)
9430 or else not Warn_On_Redundant_Constructs
9435 if not Is_Compilation_Unit (Current_Scope) then
9437 -- If the use_clause is in an inner scope, it is made redundant by
9438 -- some clause in the current context, with one exception: If we
9439 -- are compiling a nested package body, and the use_clause comes
9440 -- from then corresponding spec, the clause is not necessarily
9441 -- fully redundant, so we should not warn. If a warning was
9442 -- warranted, it would have been given when the spec was
9445 if Nkind (Parent (Decl)) = N_Package_Specification then
9447 Package_Spec_Entity : constant Entity_Id :=
9448 Defining_Unit_Name (Parent (Decl));
9450 if In_Package_Body (Package_Spec_Entity) then
9456 Redundant := Clause;
9457 Prev_Use := Cur_Use;
9459 elsif Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Body then
9461 Cur_Unit : constant Unit_Number_Type :=
9462 Get_Source_Unit (Cur_Use);
9463 New_Unit : constant Unit_Number_Type :=
9464 Get_Source_Unit (Clause);
9469 if Cur_Unit = New_Unit then
9471 -- Redundant clause in same body
9473 Redundant := Clause;
9474 Prev_Use := Cur_Use;
9476 elsif Cur_Unit = Current_Sem_Unit then
9478 -- If the new clause is not in the current unit it has been
9479 -- analyzed first, and it makes the other one redundant.
9480 -- However, if the new clause appears in a subunit, Cur_Unit
9481 -- is still the parent, and in that case the redundant one
9482 -- is the one appearing in the subunit.
9484 if Nkind (Unit (Cunit (New_Unit))) = N_Subunit then
9485 Redundant := Clause;
9486 Prev_Use := Cur_Use;
9488 -- Most common case: redundant clause in body, original
9489 -- clause in spec. Current scope is spec entity.
9491 elsif Current_Scope = Cunit_Entity (Current_Sem_Unit) then
9492 Redundant := Cur_Use;
9496 -- The new clause may appear in an unrelated unit, when
9497 -- the parents of a generic are being installed prior to
9498 -- instantiation. In this case there must be no warning.
9499 -- We detect this case by checking whether the current
9500 -- top of the stack is related to the current
9503 Scop := Current_Scope;
9504 while Present (Scop)
9505 and then Scop /= Standard_Standard
9507 if Is_Compilation_Unit (Scop)
9508 and then not Is_Child_Unit (Scop)
9512 elsif Scop = Cunit_Entity (Current_Sem_Unit) then
9516 Scop := Scope (Scop);
9519 Redundant := Cur_Use;
9523 elsif New_Unit = Current_Sem_Unit then
9524 Redundant := Clause;
9525 Prev_Use := Cur_Use;
9528 -- Neither is the current unit, so they appear in parent or
9529 -- sibling units. Warning will be emitted elsewhere.
9535 elsif Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Declaration
9536 and then Present (Parent_Spec (Unit (Cunit (Current_Sem_Unit))))
9538 -- Use_clause is in child unit of current unit, and the child unit
9539 -- appears in the context of the body of the parent, so it has
9540 -- been installed first, even though it is the redundant one.
9541 -- Depending on their placement in the context, the visible or the
9542 -- private parts of the two units, either might appear as
9543 -- redundant, but the message has to be on the current unit.
9545 if Get_Source_Unit (Cur_Use) = Current_Sem_Unit then
9546 Redundant := Cur_Use;
9549 Redundant := Clause;
9550 Prev_Use := Cur_Use;
9553 -- If the new use clause appears in the private part of a parent
9554 -- unit it may appear to be redundant w.r.t. a use clause in a
9555 -- child unit, but the previous use clause was needed in the
9556 -- visible part of the child, and no warning should be emitted.
9558 if Nkind (Parent (Decl)) = N_Package_Specification
9559 and then List_Containing (Decl) =
9560 Private_Declarations (Parent (Decl))
9563 Par : constant Entity_Id := Defining_Entity (Parent (Decl));
9564 Spec : constant Node_Id :=
9565 Specification (Unit (Cunit (Current_Sem_Unit)));
9566 Cur_List : constant List_Id := List_Containing (Cur_Use);
9568 if Is_Compilation_Unit (Par)
9569 and then Par /= Cunit_Entity (Current_Sem_Unit)
9571 if Cur_List = Context_Items (Cunit (Current_Sem_Unit))
9572 or else Cur_List = Visible_Declarations (Spec)
9580 -- Finally, if the current use clause is in the context then the
9581 -- clause is redundant when it is nested within the unit.
9583 elsif Nkind (Parent (Cur_Use)) = N_Compilation_Unit
9584 and then Nkind (Parent (Parent (Clause))) /= N_Compilation_Unit
9585 and then Get_Source_Unit (Cur_Use) = Get_Source_Unit (Clause)
9587 Redundant := Clause;
9588 Prev_Use := Cur_Use;
9591 if Present (Redundant) and then Parent (Redundant) /= Prev_Use then
9593 -- Make sure we are looking at most-descendant use_package_clause
9594 -- by traversing the chain with Find_Most_Prev and then verifying
9595 -- there is no scope manipulation via Most_Descendant_Use_Clause.
9597 if Nkind (Prev_Use) = N_Use_Package_Clause
9599 (Nkind (Parent (Prev_Use)) /= N_Compilation_Unit
9600 or else Most_Descendant_Use_Clause
9601 (Prev_Use, Find_Most_Prev (Prev_Use)) /= Prev_Use)
9603 Prev_Use := Find_Most_Prev (Prev_Use);
9606 Error_Msg_Sloc := Sloc (Prev_Use);
9607 Error_Msg_NE -- CODEFIX
9608 ("& is already use-visible through previous use_clause #??",
9609 Redundant, Pack_Name);
9611 end Note_Redundant_Use;
9615 Current_Instance : Entity_Id := Empty;
9619 Private_With_OK : Boolean := False;
9622 -- Start of processing for Use_One_Package
9625 -- Use_One_Package may have been called recursively to handle an
9626 -- implicit use for a auxiliary system package, so set P accordingly
9627 -- and skip redundancy checks.
9629 if No (Pack_Name) and then Present_System_Aux (N) then
9632 -- Check for redundant use_package_clauses
9635 -- Ignore cases where we are dealing with a non user defined package
9636 -- like Standard_Standard or something other than a valid package.
9638 if not Is_Entity_Name (Pack_Name)
9639 or else No (Entity (Pack_Name))
9640 or else Ekind (Entity (Pack_Name)) /= E_Package
9645 -- When a renaming exists we must check it for redundancy. The
9646 -- original package would have already been seen at this point.
9648 if Present (Renamed_Object (Entity (Pack_Name))) then
9649 P := Renamed_Object (Entity (Pack_Name));
9651 P := Entity (Pack_Name);
9654 -- Check for redundant clauses then set the current use clause for
9655 -- P if were are not "forcing" an installation from a scope
9656 -- reinstallation that is done throughout analysis for various
9660 Note_Redundant_Use (Pack_Name);
9663 Set_Current_Use_Clause (P, N);
9668 -- Warn about detected redundant clauses
9671 and then In_Open_Scopes (P)
9672 and then not Is_Hidden_Open_Scope (P)
9674 if Warn_On_Redundant_Constructs and then P = Current_Scope then
9675 Error_Msg_NE -- CODEFIX
9676 ("& is already use-visible within itself?r?",
9683 -- Set P back to the non-renamed package so that visiblilty of the
9684 -- entities within the package can be properly set below.
9686 P := Entity (Pack_Name);
9690 Set_Current_Use_Clause (P, N);
9692 -- Ada 2005 (AI-50217): Check restriction
9694 if From_Limited_With (P) then
9695 Error_Msg_N ("limited withed package cannot appear in use clause", N);
9698 -- Find enclosing instance, if any
9701 Current_Instance := Current_Scope;
9702 while not Is_Generic_Instance (Current_Instance) loop
9703 Current_Instance := Scope (Current_Instance);
9706 if No (Hidden_By_Use_Clause (N)) then
9707 Set_Hidden_By_Use_Clause (N, New_Elmt_List);
9711 -- If unit is a package renaming, indicate that the renamed package is
9712 -- also in use (the flags on both entities must remain consistent, and a
9713 -- subsequent use of either of them should be recognized as redundant).
9715 if Present (Renamed_Object (P)) then
9716 Set_In_Use (Renamed_Object (P));
9717 Set_Current_Use_Clause (Renamed_Object (P), N);
9718 Real_P := Renamed_Object (P);
9723 -- Ada 2005 (AI-262): Check the use_clause of a private withed package
9724 -- found in the private part of a package specification
9726 if In_Private_Part (Current_Scope)
9727 and then Has_Private_With (P)
9728 and then Is_Child_Unit (Current_Scope)
9729 and then Is_Child_Unit (P)
9730 and then Is_Ancestor_Package (Scope (Current_Scope), P)
9732 Private_With_OK := True;
9735 -- Loop through entities in one package making them potentially
9738 Id := First_Entity (P);
9740 and then (Id /= First_Private_Entity (P)
9741 or else Private_With_OK) -- Ada 2005 (AI-262)
9743 Prev := Current_Entity (Id);
9744 while Present (Prev) loop
9745 if Is_Immediately_Visible (Prev)
9746 and then (not Is_Overloadable (Prev)
9747 or else not Is_Overloadable (Id)
9748 or else (Type_Conformant (Id, Prev)))
9750 if No (Current_Instance) then
9752 -- Potentially use-visible entity remains hidden
9754 goto Next_Usable_Entity;
9756 -- A use clause within an instance hides outer global entities,
9757 -- which are not used to resolve local entities in the
9758 -- instance. Note that the predefined entities in Standard
9759 -- could not have been hidden in the generic by a use clause,
9760 -- and therefore remain visible. Other compilation units whose
9761 -- entities appear in Standard must be hidden in an instance.
9763 -- To determine whether an entity is external to the instance
9764 -- we compare the scope depth of its scope with that of the
9765 -- current instance. However, a generic actual of a subprogram
9766 -- instance is declared in the wrapper package but will not be
9767 -- hidden by a use-visible entity. similarly, an entity that is
9768 -- declared in an enclosing instance will not be hidden by an
9769 -- an entity declared in a generic actual, which can only have
9770 -- been use-visible in the generic and will not have hidden the
9771 -- entity in the generic parent.
9773 -- If Id is called Standard, the predefined package with the
9774 -- same name is in the homonym chain. It has to be ignored
9775 -- because it has no defined scope (being the only entity in
9776 -- the system with this mandated behavior).
9778 elsif not Is_Hidden (Id)
9779 and then Present (Scope (Prev))
9780 and then not Is_Wrapper_Package (Scope (Prev))
9781 and then Scope_Depth (Scope (Prev)) <
9782 Scope_Depth (Current_Instance)
9783 and then (Scope (Prev) /= Standard_Standard
9784 or else Sloc (Prev) > Standard_Location)
9786 if In_Open_Scopes (Scope (Prev))
9787 and then Is_Generic_Instance (Scope (Prev))
9788 and then Present (Associated_Formal_Package (P))
9793 Set_Is_Potentially_Use_Visible (Id);
9794 Set_Is_Immediately_Visible (Prev, False);
9795 Append_Elmt (Prev, Hidden_By_Use_Clause (N));
9799 -- A user-defined operator is not use-visible if the predefined
9800 -- operator for the type is immediately visible, which is the case
9801 -- if the type of the operand is in an open scope. This does not
9802 -- apply to user-defined operators that have operands of different
9803 -- types, because the predefined mixed mode operations (multiply
9804 -- and divide) apply to universal types and do not hide anything.
9806 elsif Ekind (Prev) = E_Operator
9807 and then Operator_Matches_Spec (Prev, Id)
9808 and then In_Open_Scopes
9809 (Scope (Base_Type (Etype (First_Formal (Id)))))
9810 and then (No (Next_Formal (First_Formal (Id)))
9811 or else Etype (First_Formal (Id)) =
9812 Etype (Next_Formal (First_Formal (Id)))
9813 or else Chars (Prev) = Name_Op_Expon)
9815 goto Next_Usable_Entity;
9817 -- In an instance, two homonyms may become use_visible through the
9818 -- actuals of distinct formal packages. In the generic, only the
9819 -- current one would have been visible, so make the other one
9822 -- In certain pathological cases it is possible that unrelated
9823 -- homonyms from distinct formal packages may exist in an
9824 -- uninstalled scope. We must test for that here.
9826 elsif Present (Current_Instance)
9827 and then Is_Potentially_Use_Visible (Prev)
9828 and then not Is_Overloadable (Prev)
9829 and then Scope (Id) /= Scope (Prev)
9830 and then Used_As_Generic_Actual (Scope (Prev))
9831 and then Used_As_Generic_Actual (Scope (Id))
9832 and then Is_List_Member (Scope (Prev))
9833 and then not In_Same_List (Current_Use_Clause (Scope (Prev)),
9834 Current_Use_Clause (Scope (Id)))
9836 Set_Is_Potentially_Use_Visible (Prev, False);
9837 Append_Elmt (Prev, Hidden_By_Use_Clause (N));
9840 Prev := Homonym (Prev);
9843 -- On exit, we know entity is not hidden, unless it is private
9845 if not Is_Hidden (Id)
9846 and then ((not Is_Child_Unit (Id)) or else Is_Visible_Lib_Unit (Id))
9848 Set_Is_Potentially_Use_Visible (Id);
9850 if Is_Private_Type (Id) and then Present (Full_View (Id)) then
9851 Set_Is_Potentially_Use_Visible (Full_View (Id));
9855 <<Next_Usable_Entity>>
9859 -- Child units are also made use-visible by a use clause, but they may
9860 -- appear after all visible declarations in the parent entity list.
9862 while Present (Id) loop
9863 if Is_Child_Unit (Id) and then Is_Visible_Lib_Unit (Id) then
9864 Set_Is_Potentially_Use_Visible (Id);
9870 if Chars (Real_P) = Name_System
9871 and then Scope (Real_P) = Standard_Standard
9872 and then Present_System_Aux (N)
9874 Use_One_Package (N);
9876 end Use_One_Package;
9882 procedure Use_One_Type
9884 Installed : Boolean := False;
9885 Force : Boolean := False)
9887 function Spec_Reloaded_For_Body return Boolean;
9888 -- Determine whether the compilation unit is a package body and the use
9889 -- type clause is in the spec of the same package. Even though the spec
9890 -- was analyzed first, its context is reloaded when analysing the body.
9892 procedure Use_Class_Wide_Operations (Typ : Entity_Id);
9893 -- AI05-150: if the use_type_clause carries the "all" qualifier,
9894 -- class-wide operations of ancestor types are use-visible if the
9895 -- ancestor type is visible.
9897 ----------------------------
9898 -- Spec_Reloaded_For_Body --
9899 ----------------------------
9901 function Spec_Reloaded_For_Body return Boolean is
9903 if Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Body then
9905 Spec : constant Node_Id :=
9906 Parent (List_Containing (Parent (Id)));
9909 -- Check whether type is declared in a package specification,
9910 -- and current unit is the corresponding package body. The
9911 -- use clauses themselves may be within a nested package.
9914 Nkind (Spec) = N_Package_Specification
9915 and then In_Same_Source_Unit
9916 (Corresponding_Body (Parent (Spec)),
9917 Cunit_Entity (Current_Sem_Unit));
9922 end Spec_Reloaded_For_Body;
9924 -------------------------------
9925 -- Use_Class_Wide_Operations --
9926 -------------------------------
9928 procedure Use_Class_Wide_Operations (Typ : Entity_Id) is
9929 function Is_Class_Wide_Operation_Of
9931 T : Entity_Id) return Boolean;
9932 -- Determine whether a subprogram has a class-wide parameter or
9933 -- result that is T'Class.
9935 ---------------------------------
9936 -- Is_Class_Wide_Operation_Of --
9937 ---------------------------------
9939 function Is_Class_Wide_Operation_Of
9941 T : Entity_Id) return Boolean
9946 Formal := First_Formal (Op);
9947 while Present (Formal) loop
9948 if Etype (Formal) = Class_Wide_Type (T) then
9952 Next_Formal (Formal);
9955 if Etype (Op) = Class_Wide_Type (T) then
9960 end Is_Class_Wide_Operation_Of;
9967 -- Start of processing for Use_Class_Wide_Operations
9970 Scop := Scope (Typ);
9971 if not Is_Hidden (Scop) then
9972 Ent := First_Entity (Scop);
9973 while Present (Ent) loop
9974 if Is_Overloadable (Ent)
9975 and then Is_Class_Wide_Operation_Of (Ent, Typ)
9976 and then not Is_Potentially_Use_Visible (Ent)
9978 Set_Is_Potentially_Use_Visible (Ent);
9979 Append_Elmt (Ent, Used_Operations (Parent (Id)));
9986 if Is_Derived_Type (Typ) then
9987 Use_Class_Wide_Operations (Etype (Base_Type (Typ)));
9989 end Use_Class_Wide_Operations;
9994 Is_Known_Used : Boolean;
9998 -- Start of processing for Use_One_Type
10001 if Entity (Id) = Any_Type then
10005 -- It is the type determined by the subtype mark (8.4(8)) whose
10006 -- operations become potentially use-visible.
10008 T := Base_Type (Entity (Id));
10010 -- Either the type itself is used, the package where it is declared is
10011 -- in use or the entity is declared in the current package, thus
10016 and then ((Present (Current_Use_Clause (T))
10017 and then All_Present (Current_Use_Clause (T)))
10018 or else not All_Present (Parent (Id))))
10019 or else In_Use (Scope (T))
10020 or else Scope (T) = Current_Scope;
10022 Set_Redundant_Use (Id,
10023 Is_Known_Used or else Is_Potentially_Use_Visible (T));
10025 if Ekind (T) = E_Incomplete_Type then
10026 Error_Msg_N ("premature usage of incomplete type", Id);
10028 elsif In_Open_Scopes (Scope (T)) then
10031 -- A limited view cannot appear in a use_type_clause. However, an access
10032 -- type whose designated type is limited has the flag but is not itself
10033 -- a limited view unless we only have a limited view of its enclosing
10036 elsif From_Limited_With (T) and then From_Limited_With (Scope (T)) then
10038 ("incomplete type from limited view cannot appear in use clause",
10041 -- If the use clause is redundant, Used_Operations will usually be
10042 -- empty, but we need to set it to empty here in one case: If we are
10043 -- instantiating a generic library unit, then we install the ancestors
10044 -- of that unit in the scope stack, which involves reprocessing use
10045 -- clauses in those ancestors. Such a use clause will typically have a
10046 -- nonempty Used_Operations unless it was redundant in the generic unit,
10047 -- even if it is redundant at the place of the instantiation.
10049 elsif Redundant_Use (Id) then
10051 -- We must avoid incorrectly setting the Current_Use_Clause when we
10052 -- are working with a redundant clause that has already been linked
10053 -- in the Prev_Use_Clause chain, otherwise the chain will break.
10055 if Present (Current_Use_Clause (T))
10056 and then Present (Prev_Use_Clause (Current_Use_Clause (T)))
10057 and then Parent (Id) = Prev_Use_Clause (Current_Use_Clause (T))
10061 Set_Current_Use_Clause (T, Parent (Id));
10064 Set_Used_Operations (Parent (Id), New_Elmt_List);
10066 -- If the subtype mark designates a subtype in a different package,
10067 -- we have to check that the parent type is visible, otherwise the
10068 -- use_type_clause is a no-op. Not clear how to do that???
10071 Set_Current_Use_Clause (T, Parent (Id));
10074 -- If T is tagged, primitive operators on class-wide operands are
10075 -- also deemed available. Note that this is really necessary only
10076 -- in semantics-only mode, because the primitive operators are not
10077 -- fully constructed in this mode, but we do it in all modes for the
10078 -- sake of uniformity, as this should not matter in practice.
10080 if Is_Tagged_Type (T) then
10081 Set_In_Use (Class_Wide_Type (T));
10084 -- Iterate over primitive operations of the type. If an operation is
10085 -- already use_visible, it is the result of a previous use_clause,
10086 -- and already appears on the corresponding entity chain. If the
10087 -- clause is being reinstalled, operations are already use-visible.
10093 Op_List := Collect_Primitive_Operations (T);
10094 Elmt := First_Elmt (Op_List);
10095 while Present (Elmt) loop
10096 if (Nkind (Node (Elmt)) = N_Defining_Operator_Symbol
10097 or else Chars (Node (Elmt)) in Any_Operator_Name)
10098 and then not Is_Hidden (Node (Elmt))
10099 and then not Is_Potentially_Use_Visible (Node (Elmt))
10101 Set_Is_Potentially_Use_Visible (Node (Elmt));
10102 Append_Elmt (Node (Elmt), Used_Operations (Parent (Id)));
10104 elsif Ada_Version >= Ada_2012
10105 and then All_Present (Parent (Id))
10106 and then not Is_Hidden (Node (Elmt))
10107 and then not Is_Potentially_Use_Visible (Node (Elmt))
10109 Set_Is_Potentially_Use_Visible (Node (Elmt));
10110 Append_Elmt (Node (Elmt), Used_Operations (Parent (Id)));
10117 if Ada_Version >= Ada_2012
10118 and then All_Present (Parent (Id))
10119 and then Is_Tagged_Type (T)
10121 Use_Class_Wide_Operations (T);
10125 -- If warning on redundant constructs, check for unnecessary WITH
10128 and then Warn_On_Redundant_Constructs
10129 and then Is_Known_Used
10131 -- with P; with P; use P;
10132 -- package P is package X is package body X is
10133 -- type T ... use P.T;
10135 -- The compilation unit is the body of X. GNAT first compiles the
10136 -- spec of X, then proceeds to the body. At that point P is marked
10137 -- as use visible. The analysis then reinstalls the spec along with
10138 -- its context. The use clause P.T is now recognized as redundant,
10139 -- but in the wrong context. Do not emit a warning in such cases.
10140 -- Do not emit a warning either if we are in an instance, there is
10141 -- no redundancy between an outer use_clause and one that appears
10142 -- within the generic.
10144 and then not Spec_Reloaded_For_Body
10145 and then not In_Instance
10146 and then not In_Inlined_Body
10148 -- The type already has a use clause
10152 -- Case where we know the current use clause for the type
10154 if Present (Current_Use_Clause (T)) then
10155 Use_Clause_Known : declare
10156 Clause1 : constant Node_Id :=
10157 Find_Most_Prev (Current_Use_Clause (T));
10158 Clause2 : constant Node_Id := Parent (Id);
10165 -- Start of processing for Use_Clause_Known
10168 -- If both current use_type_clause and the use_type_clause
10169 -- for the type are at the compilation unit level, one of
10170 -- the units must be an ancestor of the other, and the
10171 -- warning belongs on the descendant.
10173 if Nkind (Parent (Clause1)) = N_Compilation_Unit
10175 Nkind (Parent (Clause2)) = N_Compilation_Unit
10177 -- If the unit is a subprogram body that acts as spec,
10178 -- the context clause is shared with the constructed
10179 -- subprogram spec. Clearly there is no redundancy.
10181 if Clause1 = Clause2 then
10185 Unit1 := Unit (Parent (Clause1));
10186 Unit2 := Unit (Parent (Clause2));
10188 -- If both clauses are on same unit, or one is the body
10189 -- of the other, or one of them is in a subunit, report
10190 -- redundancy on the later one.
10192 if Unit1 = Unit2 or else Nkind (Unit1) = N_Subunit then
10193 Error_Msg_Sloc := Sloc (Current_Use_Clause (T));
10194 Error_Msg_NE -- CODEFIX
10195 ("& is already use-visible through previous "
10196 & "use_type_clause #??", Clause1, T);
10199 elsif Nkind_In (Unit2, N_Package_Body, N_Subprogram_Body)
10200 and then Nkind (Unit1) /= Nkind (Unit2)
10201 and then Nkind (Unit1) /= N_Subunit
10203 Error_Msg_Sloc := Sloc (Clause1);
10204 Error_Msg_NE -- CODEFIX
10205 ("& is already use-visible through previous "
10206 & "use_type_clause #??", Current_Use_Clause (T), T);
10210 -- There is a redundant use_type_clause in a child unit.
10211 -- Determine which of the units is more deeply nested.
10212 -- If a unit is a package instance, retrieve the entity
10213 -- and its scope from the instance spec.
10215 Ent1 := Entity_Of_Unit (Unit1);
10216 Ent2 := Entity_Of_Unit (Unit2);
10218 if Scope (Ent2) = Standard_Standard then
10219 Error_Msg_Sloc := Sloc (Current_Use_Clause (T));
10222 elsif Scope (Ent1) = Standard_Standard then
10223 Error_Msg_Sloc := Sloc (Id);
10226 -- If both units are child units, we determine which one
10227 -- is the descendant by the scope distance to the
10228 -- ultimate parent unit.
10236 S1 := Scope (Ent1);
10237 S2 := Scope (Ent2);
10239 and then Present (S2)
10240 and then S1 /= Standard_Standard
10241 and then S2 /= Standard_Standard
10247 if S1 = Standard_Standard then
10248 Error_Msg_Sloc := Sloc (Id);
10251 Error_Msg_Sloc := Sloc (Current_Use_Clause (T));
10257 if Parent (Id) /= Err_No then
10258 if Most_Descendant_Use_Clause
10259 (Err_No, Parent (Id)) = Parent (Id)
10261 Error_Msg_Sloc := Sloc (Err_No);
10262 Err_No := Parent (Id);
10265 Error_Msg_NE -- CODEFIX
10266 ("& is already use-visible through previous "
10267 & "use_type_clause #??", Err_No, Id);
10270 -- Case where current use_type_clause and use_type_clause
10271 -- for the type are not both at the compilation unit level.
10272 -- In this case we don't have location information.
10275 Error_Msg_NE -- CODEFIX
10276 ("& is already use-visible through previous "
10277 & "use_type_clause??", Id, T);
10279 end Use_Clause_Known;
10281 -- Here if Current_Use_Clause is not set for T, another case where
10282 -- we do not have the location information available.
10285 Error_Msg_NE -- CODEFIX
10286 ("& is already use-visible through previous "
10287 & "use_type_clause??", Id, T);
10290 -- The package where T is declared is already used
10292 elsif In_Use (Scope (T)) then
10293 -- Due to expansion of contracts we could be attempting to issue
10294 -- a spurious warning - so verify there is a previous use clause.
10296 if Current_Use_Clause (Scope (T)) /=
10297 Find_Most_Prev (Current_Use_Clause (Scope (T)))
10300 Sloc (Find_Most_Prev (Current_Use_Clause (Scope (T))));
10301 Error_Msg_NE -- CODEFIX
10302 ("& is already use-visible through package use clause #??",
10306 -- The current scope is the package where T is declared
10309 Error_Msg_Node_2 := Scope (T);
10310 Error_Msg_NE -- CODEFIX
10311 ("& is already use-visible inside package &??", Id, T);
10320 procedure Write_Info is
10321 Id : Entity_Id := First_Entity (Current_Scope);
10324 -- No point in dumping standard entities
10326 if Current_Scope = Standard_Standard then
10330 Write_Str ("========================================================");
10332 Write_Str (" Defined Entities in ");
10333 Write_Name (Chars (Current_Scope));
10335 Write_Str ("========================================================");
10339 Write_Str ("-- none --");
10343 while Present (Id) loop
10344 Write_Entity_Info (Id, " ");
10349 if Scope (Current_Scope) = Standard_Standard then
10351 -- Print information on the current unit itself
10353 Write_Entity_Info (Current_Scope, " ");
10366 for J in reverse 1 .. Scope_Stack.Last loop
10367 S := Scope_Stack.Table (J).Entity;
10368 Write_Int (Int (S));
10369 Write_Str (" === ");
10370 Write_Name (Chars (S));
10379 procedure we (S : Entity_Id) is
10382 E := First_Entity (S);
10383 while Present (E) loop
10384 Write_Int (Int (E));
10385 Write_Str (" === ");
10386 Write_Name (Chars (E));