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;
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 Is_Anonymous_Access_Type (Etype (Expression (Nam)))
1044 and then not Is_Anonymous_Access_Type (T)
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 denotes a generic formal object of a generic unit G, and the
2008 -- renaming (or instantiation containing the actual) occurs within the
2009 -- body of G or within the body of a generic unit declared within the
2010 -- declarative region of G, then the corresponding parameter of G
2011 -- shall have a null_exclusion; Otherwise the subtype of the Sub's
2012 -- formal parameter shall exclude null.
2014 -- Similarly for its return profile.
2016 procedure Check_SPARK_Primitive_Operation (Subp_Id : Entity_Id);
2017 -- Ensure that a SPARK renaming denoted by its entity Subp_Id does not
2018 -- declare a primitive operation of a tagged type (SPARK RM 6.1.1(3)).
2020 procedure Freeze_Actual_Profile;
2021 -- In Ada 2012, enforce the freezing rule concerning formal incomplete
2022 -- types: a callable entity freezes its profile, unless it has an
2023 -- incomplete untagged formal (RM 13.14(10.2/3)).
2025 function Has_Class_Wide_Actual return Boolean;
2026 -- Ada 2012 (AI05-071, AI05-0131): True if N is the renaming for a
2027 -- defaulted formal subprogram where the actual for the controlling
2028 -- formal type is class-wide.
2030 function Original_Subprogram (Subp : Entity_Id) return Entity_Id;
2031 -- Find renamed entity when the declaration is a renaming_as_body and
2032 -- the renamed entity may itself be a renaming_as_body. Used to enforce
2033 -- rule that a renaming_as_body is illegal if the declaration occurs
2034 -- before the subprogram it completes is frozen, and renaming indirectly
2035 -- renames the subprogram itself.(Defect Report 8652/0027).
2037 ------------------------------
2038 -- Build_Class_Wide_Wrapper --
2039 ------------------------------
2041 procedure Build_Class_Wide_Wrapper
2042 (Ren_Id : out Entity_Id;
2043 Wrap_Id : out Entity_Id)
2045 Loc : constant Source_Ptr := Sloc (N);
2048 (Subp_Id : Entity_Id;
2049 Params : List_Id) return Node_Id;
2050 -- Create a dispatching call to invoke routine Subp_Id with actuals
2051 -- built from the parameter specifications of list Params.
2053 function Build_Expr_Fun_Call
2054 (Subp_Id : Entity_Id;
2055 Params : List_Id) return Node_Id;
2056 -- Create a dispatching call to invoke function Subp_Id with actuals
2057 -- built from the parameter specifications of list Params. Return
2058 -- directly the call, so that it can be used inside an expression
2059 -- function. This is a specificity of the GNATprove mode.
2061 function Build_Spec (Subp_Id : Entity_Id) return Node_Id;
2062 -- Create a subprogram specification based on the subprogram profile
2065 function Find_Primitive (Typ : Entity_Id) return Entity_Id;
2066 -- Find a primitive subprogram of type Typ which matches the profile
2067 -- of the renaming declaration.
2069 procedure Interpretation_Error (Subp_Id : Entity_Id);
2070 -- Emit a continuation error message suggesting subprogram Subp_Id as
2071 -- a possible interpretation.
2073 function Is_Intrinsic_Equality (Subp_Id : Entity_Id) return Boolean;
2074 -- Determine whether subprogram Subp_Id denotes the intrinsic "="
2077 function Is_Suitable_Candidate (Subp_Id : Entity_Id) return Boolean;
2078 -- Determine whether subprogram Subp_Id is a suitable candidate for
2079 -- the role of a wrapped subprogram.
2086 (Subp_Id : Entity_Id;
2087 Params : List_Id) return Node_Id
2089 Actuals : constant List_Id := New_List;
2090 Call_Ref : constant Node_Id := New_Occurrence_Of (Subp_Id, Loc);
2094 -- Build the actual parameters of the call
2096 Formal := First (Params);
2097 while Present (Formal) loop
2099 Make_Identifier (Loc, Chars (Defining_Identifier (Formal))));
2104 -- return Subp_Id (Actuals);
2106 if Ekind_In (Subp_Id, E_Function, E_Operator) then
2108 Make_Simple_Return_Statement (Loc,
2110 Make_Function_Call (Loc,
2112 Parameter_Associations => Actuals));
2115 -- Subp_Id (Actuals);
2119 Make_Procedure_Call_Statement (Loc,
2121 Parameter_Associations => Actuals);
2125 -------------------------
2126 -- Build_Expr_Fun_Call --
2127 -------------------------
2129 function Build_Expr_Fun_Call
2130 (Subp_Id : Entity_Id;
2131 Params : List_Id) return Node_Id
2133 Actuals : constant List_Id := New_List;
2134 Call_Ref : constant Node_Id := New_Occurrence_Of (Subp_Id, Loc);
2138 pragma Assert (Ekind_In (Subp_Id, E_Function, E_Operator));
2140 -- Build the actual parameters of the call
2142 Formal := First (Params);
2143 while Present (Formal) loop
2145 Make_Identifier (Loc, Chars (Defining_Identifier (Formal))));
2150 -- Subp_Id (Actuals);
2153 Make_Function_Call (Loc,
2155 Parameter_Associations => Actuals);
2156 end Build_Expr_Fun_Call;
2162 function Build_Spec (Subp_Id : Entity_Id) return Node_Id is
2163 Params : constant List_Id := Copy_Parameter_List (Subp_Id);
2164 Spec_Id : constant Entity_Id :=
2165 Make_Defining_Identifier (Loc,
2166 Chars => New_External_Name (Chars (Subp_Id), 'R'));
2169 if Ekind (Formal_Spec) = E_Procedure then
2171 Make_Procedure_Specification (Loc,
2172 Defining_Unit_Name => Spec_Id,
2173 Parameter_Specifications => Params);
2176 Make_Function_Specification (Loc,
2177 Defining_Unit_Name => Spec_Id,
2178 Parameter_Specifications => Params,
2179 Result_Definition =>
2180 New_Copy_Tree (Result_Definition (Spec)));
2184 --------------------
2185 -- Find_Primitive --
2186 --------------------
2188 function Find_Primitive (Typ : Entity_Id) return Entity_Id is
2189 procedure Replace_Parameter_Types (Spec : Node_Id);
2190 -- Given a specification Spec, replace all class-wide parameter
2191 -- types with reference to type Typ.
2193 -----------------------------
2194 -- Replace_Parameter_Types --
2195 -----------------------------
2197 procedure Replace_Parameter_Types (Spec : Node_Id) is
2199 Formal_Id : Entity_Id;
2200 Formal_Typ : Node_Id;
2203 Formal := First (Parameter_Specifications (Spec));
2204 while Present (Formal) loop
2205 Formal_Id := Defining_Identifier (Formal);
2206 Formal_Typ := Parameter_Type (Formal);
2208 -- Create a new entity for each class-wide formal to prevent
2209 -- aliasing with the original renaming. Replace the type of
2210 -- such a parameter with the candidate type.
2212 if Nkind (Formal_Typ) = N_Identifier
2213 and then Is_Class_Wide_Type (Etype (Formal_Typ))
2215 Set_Defining_Identifier (Formal,
2216 Make_Defining_Identifier (Loc, Chars (Formal_Id)));
2218 Set_Parameter_Type (Formal, New_Occurrence_Of (Typ, Loc));
2223 end Replace_Parameter_Types;
2227 Alt_Ren : constant Node_Id := New_Copy_Tree (N);
2228 Alt_Nam : constant Node_Id := Name (Alt_Ren);
2229 Alt_Spec : constant Node_Id := Specification (Alt_Ren);
2230 Subp_Id : Entity_Id;
2232 -- Start of processing for Find_Primitive
2235 -- Each attempt to find a suitable primitive of a particular type
2236 -- operates on its own copy of the original renaming. As a result
2237 -- the original renaming is kept decoration and side-effect free.
2239 -- Inherit the overloaded status of the renamed subprogram name
2241 if Is_Overloaded (Nam) then
2242 Set_Is_Overloaded (Alt_Nam);
2243 Save_Interps (Nam, Alt_Nam);
2246 -- The copied renaming is hidden from visibility to prevent the
2247 -- pollution of the enclosing context.
2249 Set_Defining_Unit_Name (Alt_Spec, Make_Temporary (Loc, 'R'));
2251 -- The types of all class-wide parameters must be changed to the
2254 Replace_Parameter_Types (Alt_Spec);
2256 -- Try to find a suitable primitive which matches the altered
2257 -- profile of the renaming specification.
2262 Nam => Name (Alt_Ren),
2263 New_S => Analyze_Subprogram_Specification (Alt_Spec),
2264 Is_Actual => Is_Actual);
2266 -- Do not return Any_Id if the resolion of the altered profile
2267 -- failed as this complicates further checks on the caller side,
2268 -- return Empty instead.
2270 if Subp_Id = Any_Id then
2277 --------------------------
2278 -- Interpretation_Error --
2279 --------------------------
2281 procedure Interpretation_Error (Subp_Id : Entity_Id) is
2283 Error_Msg_Sloc := Sloc (Subp_Id);
2285 if Is_Internal (Subp_Id) then
2287 ("\\possible interpretation: predefined & #",
2291 ("\\possible interpretation: & defined #", Spec, Formal_Spec);
2293 end Interpretation_Error;
2295 ---------------------------
2296 -- Is_Intrinsic_Equality --
2297 ---------------------------
2299 function Is_Intrinsic_Equality (Subp_Id : Entity_Id) return Boolean is
2302 Ekind (Subp_Id) = E_Operator
2303 and then Chars (Subp_Id) = Name_Op_Eq
2304 and then Is_Intrinsic_Subprogram (Subp_Id);
2305 end Is_Intrinsic_Equality;
2307 ---------------------------
2308 -- Is_Suitable_Candidate --
2309 ---------------------------
2311 function Is_Suitable_Candidate (Subp_Id : Entity_Id) return Boolean is
2313 if No (Subp_Id) then
2316 -- An intrinsic subprogram is never a good candidate. This is an
2317 -- indication of a missing primitive, either defined directly or
2318 -- inherited from a parent tagged type.
2320 elsif Is_Intrinsic_Subprogram (Subp_Id) then
2326 end Is_Suitable_Candidate;
2330 Actual_Typ : Entity_Id := Empty;
2331 -- The actual class-wide type for Formal_Typ
2333 CW_Prim_OK : Boolean;
2334 CW_Prim_Op : Entity_Id;
2335 -- The class-wide subprogram (if available) which corresponds to the
2336 -- renamed generic formal subprogram.
2338 Formal_Typ : Entity_Id := Empty;
2339 -- The generic formal type with unknown discriminants
2341 Root_Prim_OK : Boolean;
2342 Root_Prim_Op : Entity_Id;
2343 -- The root type primitive (if available) which corresponds to the
2344 -- renamed generic formal subprogram.
2346 Root_Typ : Entity_Id := Empty;
2347 -- The root type of Actual_Typ
2349 Body_Decl : Node_Id;
2351 Prim_Op : Entity_Id;
2352 Spec_Decl : Node_Id;
2355 -- Start of processing for Build_Class_Wide_Wrapper
2358 -- Analyze the specification of the renaming in case the generation
2359 -- of the class-wide wrapper fails.
2361 Ren_Id := Analyze_Subprogram_Specification (Spec);
2364 -- Do not attempt to build a wrapper if the renaming is in error
2366 if Error_Posted (Nam) then
2370 -- Analyze the renamed name, but do not resolve it. The resolution is
2371 -- completed once a suitable subprogram is found.
2375 -- When the renamed name denotes the intrinsic operator equals, the
2376 -- name must be treated as overloaded. This allows for a potential
2377 -- match against the root type's predefined equality function.
2379 if Is_Intrinsic_Equality (Entity (Nam)) then
2380 Set_Is_Overloaded (Nam);
2381 Collect_Interps (Nam);
2384 -- Step 1: Find the generic formal type with unknown discriminants
2385 -- and its corresponding class-wide actual type from the renamed
2386 -- generic formal subprogram.
2388 Formal := First_Formal (Formal_Spec);
2389 while Present (Formal) loop
2390 if Has_Unknown_Discriminants (Etype (Formal))
2391 and then not Is_Class_Wide_Type (Etype (Formal))
2392 and then Is_Class_Wide_Type (Get_Instance_Of (Etype (Formal)))
2394 Formal_Typ := Etype (Formal);
2395 Actual_Typ := Get_Instance_Of (Formal_Typ);
2396 Root_Typ := Etype (Actual_Typ);
2400 Next_Formal (Formal);
2403 -- The specification of the generic formal subprogram should always
2404 -- contain a formal type with unknown discriminants whose actual is
2405 -- a class-wide type, otherwise this indicates a failure in routine
2406 -- Has_Class_Wide_Actual.
2408 pragma Assert (Present (Formal_Typ));
2410 -- Step 2: Find the proper class-wide subprogram or primitive which
2411 -- corresponds to the renamed generic formal subprogram.
2413 CW_Prim_Op := Find_Primitive (Actual_Typ);
2414 CW_Prim_OK := Is_Suitable_Candidate (CW_Prim_Op);
2415 Root_Prim_Op := Find_Primitive (Root_Typ);
2416 Root_Prim_OK := Is_Suitable_Candidate (Root_Prim_Op);
2418 -- The class-wide actual type has two subprograms which correspond to
2419 -- the renamed generic formal subprogram:
2421 -- with procedure Prim_Op (Param : Formal_Typ);
2423 -- procedure Prim_Op (Param : Actual_Typ); -- may be inherited
2424 -- procedure Prim_Op (Param : Actual_Typ'Class);
2426 -- Even though the declaration of the two subprograms is legal, a
2427 -- call to either one is ambiguous and therefore illegal.
2429 if CW_Prim_OK and Root_Prim_OK then
2431 -- A user-defined primitive has precedence over a predefined one
2433 if Is_Internal (CW_Prim_Op)
2434 and then not Is_Internal (Root_Prim_Op)
2436 Prim_Op := Root_Prim_Op;
2438 elsif Is_Internal (Root_Prim_Op)
2439 and then not Is_Internal (CW_Prim_Op)
2441 Prim_Op := CW_Prim_Op;
2443 elsif CW_Prim_Op = Root_Prim_Op then
2444 Prim_Op := Root_Prim_Op;
2446 -- Otherwise both candidate subprograms are user-defined and
2451 ("ambiguous actual for generic subprogram &",
2453 Interpretation_Error (Root_Prim_Op);
2454 Interpretation_Error (CW_Prim_Op);
2458 elsif CW_Prim_OK and not Root_Prim_OK then
2459 Prim_Op := CW_Prim_Op;
2461 elsif not CW_Prim_OK and Root_Prim_OK then
2462 Prim_Op := Root_Prim_Op;
2464 -- An intrinsic equality may act as a suitable candidate in the case
2465 -- of a null type extension where the parent's equality is hidden. A
2466 -- call to an intrinsic equality is expanded as dispatching.
2468 elsif Present (Root_Prim_Op)
2469 and then Is_Intrinsic_Equality (Root_Prim_Op)
2471 Prim_Op := Root_Prim_Op;
2473 -- Otherwise there are no candidate subprograms. Let the caller
2474 -- diagnose the error.
2480 -- At this point resolution has taken place and the name is no longer
2481 -- overloaded. Mark the primitive as referenced.
2483 Set_Is_Overloaded (Name (N), False);
2484 Set_Referenced (Prim_Op);
2486 -- Do not generate a wrapper when the only candidate is a class-wide
2487 -- subprogram. Instead modify the renaming to directly map the actual
2488 -- to the generic formal.
2490 if CW_Prim_OK and then Prim_Op = CW_Prim_Op then
2492 Rewrite (Nam, New_Occurrence_Of (Prim_Op, Loc));
2496 -- Step 3: Create the declaration and the body of the wrapper, insert
2497 -- all the pieces into the tree.
2499 -- In GNATprove mode, create a function wrapper in the form of an
2500 -- expression function, so that an implicit postcondition relating
2501 -- the result of calling the wrapper function and the result of the
2502 -- dispatching call to the wrapped function is known during proof.
2505 and then Ekind_In (Ren_Id, E_Function, E_Operator)
2507 New_Spec := Build_Spec (Ren_Id);
2509 Make_Expression_Function (Loc,
2510 Specification => New_Spec,
2513 (Subp_Id => Prim_Op,
2514 Params => Parameter_Specifications (New_Spec)));
2516 Wrap_Id := Defining_Entity (Body_Decl);
2518 -- Otherwise, create separate spec and body for the subprogram
2522 Make_Subprogram_Declaration (Loc,
2523 Specification => Build_Spec (Ren_Id));
2524 Insert_Before_And_Analyze (N, Spec_Decl);
2526 Wrap_Id := Defining_Entity (Spec_Decl);
2529 Make_Subprogram_Body (Loc,
2530 Specification => Build_Spec (Ren_Id),
2531 Declarations => New_List,
2532 Handled_Statement_Sequence =>
2533 Make_Handled_Sequence_Of_Statements (Loc,
2534 Statements => New_List (
2536 (Subp_Id => Prim_Op,
2538 Parameter_Specifications
2539 (Specification (Spec_Decl))))));
2541 Set_Corresponding_Body (Spec_Decl, Defining_Entity (Body_Decl));
2544 -- If the operator carries an Eliminated pragma, indicate that the
2545 -- wrapper is also to be eliminated, to prevent spurious error when
2546 -- using gnatelim on programs that include box-initialization of
2547 -- equality operators.
2549 Set_Is_Eliminated (Wrap_Id, Is_Eliminated (Prim_Op));
2551 -- In GNATprove mode, insert the body in the tree for analysis
2553 if GNATprove_Mode then
2554 Insert_Before_And_Analyze (N, Body_Decl);
2557 -- The generated body does not freeze and must be analyzed when the
2558 -- class-wide wrapper is frozen. The body is only needed if expansion
2561 if Expander_Active then
2562 Append_Freeze_Action (Wrap_Id, Body_Decl);
2565 -- Step 4: The subprogram renaming aliases the wrapper
2567 Rewrite (Nam, New_Occurrence_Of (Wrap_Id, Loc));
2568 end Build_Class_Wide_Wrapper;
2570 --------------------------
2571 -- Check_Null_Exclusion --
2572 --------------------------
2574 procedure Check_Null_Exclusion
2578 Ren_Formal : Entity_Id;
2579 Sub_Formal : Entity_Id;
2581 function Null_Exclusion_Mismatch
2582 (Renaming : Entity_Id; Renamed : Entity_Id) return Boolean;
2583 -- Return True if there is a null exclusion mismatch between
2584 -- Renaming and Renamed, False otherwise.
2586 -----------------------------
2587 -- Null_Exclusion_Mismatch --
2588 -----------------------------
2590 function Null_Exclusion_Mismatch
2591 (Renaming : Entity_Id; Renamed : Entity_Id) return Boolean is
2593 return Has_Null_Exclusion (Parent (Renaming))
2595 not (Has_Null_Exclusion (Parent (Renamed))
2596 or else (Can_Never_Be_Null (Etype (Renamed))
2598 (Is_Formal_Subprogram (Sub)
2599 and then In_Generic_Body (Current_Scope))));
2600 end Null_Exclusion_Mismatch;
2605 Ren_Formal := First_Formal (Ren);
2606 Sub_Formal := First_Formal (Sub);
2607 while Present (Ren_Formal) and then Present (Sub_Formal) loop
2608 if Null_Exclusion_Mismatch (Ren_Formal, Sub_Formal) then
2609 Error_Msg_Sloc := Sloc (Sub_Formal);
2611 ("`NOT NULL` required for parameter &#",
2612 Ren_Formal, Sub_Formal);
2615 Next_Formal (Ren_Formal);
2616 Next_Formal (Sub_Formal);
2619 -- Return profile check
2621 if Nkind (Parent (Ren)) = N_Function_Specification
2622 and then Nkind (Parent (Sub)) = N_Function_Specification
2623 and then Null_Exclusion_Mismatch (Ren, Sub)
2625 Error_Msg_Sloc := Sloc (Sub);
2626 Error_Msg_N ("return must specify `NOT NULL`#", Ren);
2628 end Check_Null_Exclusion;
2630 -------------------------------------
2631 -- Check_SPARK_Primitive_Operation --
2632 -------------------------------------
2634 procedure Check_SPARK_Primitive_Operation (Subp_Id : Entity_Id) is
2635 Prag : constant Node_Id := SPARK_Pragma (Subp_Id);
2639 -- Nothing to do when the subprogram is not subject to SPARK_Mode On
2640 -- because this check applies to SPARK code only.
2642 if not (Present (Prag)
2643 and then Get_SPARK_Mode_From_Annotation (Prag) = On)
2647 -- Nothing to do when the subprogram is not a primitive operation
2649 elsif not Is_Primitive (Subp_Id) then
2653 Typ := Find_Dispatching_Type (Subp_Id);
2655 -- Nothing to do when the subprogram is a primitive operation of an
2662 -- At this point a renaming declaration introduces a new primitive
2663 -- operation for a tagged type.
2665 Error_Msg_Node_2 := Typ;
2667 ("subprogram renaming & cannot declare primitive for type & "
2668 & "(SPARK RM 6.1.1(3))", N, Subp_Id);
2669 end Check_SPARK_Primitive_Operation;
2671 ---------------------------
2672 -- Freeze_Actual_Profile --
2673 ---------------------------
2675 procedure Freeze_Actual_Profile is
2677 Has_Untagged_Inc : Boolean;
2678 Instantiation_Node : constant Node_Id := Parent (N);
2681 if Ada_Version >= Ada_2012 then
2682 F := First_Formal (Formal_Spec);
2683 Has_Untagged_Inc := False;
2684 while Present (F) loop
2685 if Ekind (Etype (F)) = E_Incomplete_Type
2686 and then not Is_Tagged_Type (Etype (F))
2688 Has_Untagged_Inc := True;
2695 if Ekind (Formal_Spec) = E_Function
2696 and then not Is_Tagged_Type (Etype (Formal_Spec))
2698 Has_Untagged_Inc := True;
2701 if not Has_Untagged_Inc then
2702 F := First_Formal (Old_S);
2703 while Present (F) loop
2704 Freeze_Before (Instantiation_Node, Etype (F));
2706 if Is_Incomplete_Or_Private_Type (Etype (F))
2707 and then No (Underlying_Type (Etype (F)))
2709 -- Exclude generic types, or types derived from them.
2710 -- They will be frozen in the enclosing instance.
2712 if Is_Generic_Type (Etype (F))
2713 or else Is_Generic_Type (Root_Type (Etype (F)))
2717 -- A limited view of a type declared elsewhere needs no
2718 -- freezing actions.
2720 elsif From_Limited_With (Etype (F)) then
2725 ("type& must be frozen before this point",
2726 Instantiation_Node, Etype (F));
2734 end Freeze_Actual_Profile;
2736 ---------------------------
2737 -- Has_Class_Wide_Actual --
2738 ---------------------------
2740 function Has_Class_Wide_Actual return Boolean is
2742 Formal_Typ : Entity_Id;
2746 Formal := First_Formal (Formal_Spec);
2747 while Present (Formal) loop
2748 Formal_Typ := Etype (Formal);
2750 if Has_Unknown_Discriminants (Formal_Typ)
2751 and then not Is_Class_Wide_Type (Formal_Typ)
2752 and then Is_Class_Wide_Type (Get_Instance_Of (Formal_Typ))
2757 Next_Formal (Formal);
2762 end Has_Class_Wide_Actual;
2764 -------------------------
2765 -- Original_Subprogram --
2766 -------------------------
2768 function Original_Subprogram (Subp : Entity_Id) return Entity_Id is
2769 Orig_Decl : Node_Id;
2770 Orig_Subp : Entity_Id;
2773 -- First case: renamed entity is itself a renaming
2775 if Present (Alias (Subp)) then
2776 return Alias (Subp);
2778 elsif Nkind (Unit_Declaration_Node (Subp)) = N_Subprogram_Declaration
2779 and then Present (Corresponding_Body (Unit_Declaration_Node (Subp)))
2781 -- Check if renamed entity is a renaming_as_body
2784 Unit_Declaration_Node
2785 (Corresponding_Body (Unit_Declaration_Node (Subp)));
2787 if Nkind (Orig_Decl) = N_Subprogram_Renaming_Declaration then
2788 Orig_Subp := Entity (Name (Orig_Decl));
2790 if Orig_Subp = Rename_Spec then
2792 -- Circularity detected
2797 return (Original_Subprogram (Orig_Subp));
2805 end Original_Subprogram;
2809 CW_Actual : constant Boolean := Has_Class_Wide_Actual;
2810 -- Ada 2012 (AI05-071, AI05-0131): True if the renaming is for a
2811 -- defaulted formal subprogram when the actual for a related formal
2812 -- type is class-wide.
2814 Inst_Node : Node_Id := Empty;
2817 -- Start of processing for Analyze_Subprogram_Renaming
2820 -- We must test for the attribute renaming case before the Analyze
2821 -- call because otherwise Sem_Attr will complain that the attribute
2822 -- is missing an argument when it is analyzed.
2824 if Nkind (Nam) = N_Attribute_Reference then
2826 -- In the case of an abstract formal subprogram association, rewrite
2827 -- an actual given by a stream or Put_Image attribute as the name of
2828 -- the corresponding stream or Put_Image primitive of the type.
2830 -- In a generic context the stream and Put_Image operations are not
2831 -- generated, and this must be treated as a normal attribute
2832 -- reference, to be expanded in subsequent instantiations.
2835 and then Is_Abstract_Subprogram (Formal_Spec)
2836 and then Expander_Active
2839 Prefix_Type : constant Entity_Id := Entity (Prefix (Nam));
2843 -- The class-wide forms of the stream and Put_Image attributes
2844 -- are not primitive dispatching operations (even though they
2845 -- internally dispatch).
2847 if Is_Class_Wide_Type (Prefix_Type) then
2849 ("attribute must be a primitive dispatching operation",
2854 -- Retrieve the primitive subprogram associated with the
2855 -- attribute. This can only be a stream attribute, since those
2856 -- are the only ones that are dispatching (and the actual for
2857 -- an abstract formal subprogram must be dispatching
2860 case Attribute_Name (Nam) is
2863 Find_Optional_Prim_Op (Prefix_Type, TSS_Stream_Input);
2867 Find_Optional_Prim_Op (Prefix_Type, TSS_Stream_Output);
2871 Find_Optional_Prim_Op (Prefix_Type, TSS_Stream_Read);
2875 Find_Optional_Prim_Op (Prefix_Type, TSS_Stream_Write);
2877 when Name_Put_Image =>
2879 Find_Optional_Prim_Op (Prefix_Type, TSS_Put_Image);
2883 ("attribute must be a primitive dispatching operation",
2888 -- If no stream operation was found, and the type is limited,
2889 -- the user should have defined one. This rule does not apply
2893 and then Attribute_Name (Nam) /= Name_Put_Image
2895 if Is_Limited_Type (Prefix_Type) then
2897 ("stream operation not defined for type&",
2901 -- Otherwise, compiler should have generated default
2904 raise Program_Error;
2908 -- Rewrite the attribute into the name of its corresponding
2909 -- primitive dispatching subprogram. We can then proceed with
2910 -- the usual processing for subprogram renamings.
2913 Prim_Name : constant Node_Id :=
2914 Make_Identifier (Sloc (Nam),
2915 Chars => Chars (Prim));
2917 Set_Entity (Prim_Name, Prim);
2918 Rewrite (Nam, Prim_Name);
2923 -- Normal processing for a renaming of an attribute
2926 Attribute_Renaming (N);
2931 -- Check whether this declaration corresponds to the instantiation of a
2932 -- formal subprogram.
2934 -- If this is an instantiation, the corresponding actual is frozen and
2935 -- error messages can be made more precise. If this is a default
2936 -- subprogram, the entity is already established in the generic, and is
2937 -- not retrieved by visibility. If it is a default with a box, the
2938 -- candidate interpretations, if any, have been collected when building
2939 -- the renaming declaration. If overloaded, the proper interpretation is
2940 -- determined in Find_Renamed_Entity. If the entity is an operator,
2941 -- Find_Renamed_Entity applies additional visibility checks.
2944 Inst_Node := Unit_Declaration_Node (Formal_Spec);
2946 -- Check whether the renaming is for a defaulted actual subprogram
2947 -- with a class-wide actual.
2949 -- The class-wide wrapper is not needed in GNATprove_Mode and there
2950 -- is an external axiomatization on the package.
2953 and then Box_Present (Inst_Node)
2957 Present (Containing_Package_With_Ext_Axioms (Formal_Spec)))
2959 Build_Class_Wide_Wrapper (New_S, Old_S);
2961 elsif Is_Entity_Name (Nam)
2962 and then Present (Entity (Nam))
2963 and then not Comes_From_Source (Nam)
2964 and then not Is_Overloaded (Nam)
2966 Old_S := Entity (Nam);
2968 -- The subprogram renaming declaration may become Ghost if it
2969 -- renames a Ghost entity.
2971 Mark_Ghost_Renaming (N, Old_S);
2973 New_S := Analyze_Subprogram_Specification (Spec);
2977 if Ekind (Old_S) = E_Operator then
2981 if Box_Present (Inst_Node) then
2982 Old_S := Find_Renamed_Entity (N, Name (N), New_S, Is_Actual);
2984 -- If there is an immediately visible homonym of the operator
2985 -- and the declaration has a default, this is worth a warning
2986 -- because the user probably did not intend to get the pre-
2987 -- defined operator, visible in the generic declaration. To
2988 -- find if there is an intended candidate, analyze the renaming
2989 -- again in the current context.
2991 elsif Scope (Old_S) = Standard_Standard
2992 and then Present (Default_Name (Inst_Node))
2995 Decl : constant Node_Id := New_Copy_Tree (N);
2999 Set_Entity (Name (Decl), Empty);
3000 Analyze (Name (Decl));
3002 Find_Renamed_Entity (Decl, Name (Decl), New_S, True);
3005 and then In_Open_Scopes (Scope (Hidden))
3006 and then Is_Immediately_Visible (Hidden)
3007 and then Comes_From_Source (Hidden)
3008 and then Hidden /= Old_S
3010 Error_Msg_Sloc := Sloc (Hidden);
3012 ("default subprogram is resolved in the generic "
3013 & "declaration (RM 12.6(17))??", N);
3014 Error_Msg_NE ("\and will not use & #??", N, Hidden);
3023 -- The subprogram renaming declaration may become Ghost if it
3024 -- renames a Ghost entity.
3026 if Is_Entity_Name (Nam) then
3027 Mark_Ghost_Renaming (N, Entity (Nam));
3030 New_S := Analyze_Subprogram_Specification (Spec);
3034 -- Renamed entity must be analyzed first, to avoid being hidden by
3035 -- new name (which might be the same in a generic instance).
3039 -- The subprogram renaming declaration may become Ghost if it renames
3042 if Is_Entity_Name (Nam) then
3043 Mark_Ghost_Renaming (N, Entity (Nam));
3046 -- The renaming defines a new overloaded entity, which is analyzed
3047 -- like a subprogram declaration.
3049 New_S := Analyze_Subprogram_Specification (Spec);
3052 if Current_Scope /= Standard_Standard then
3053 Set_Is_Pure (New_S, Is_Pure (Current_Scope));
3056 -- Set SPARK mode from current context
3058 Set_SPARK_Pragma (New_S, SPARK_Mode_Pragma);
3059 Set_SPARK_Pragma_Inherited (New_S);
3061 Rename_Spec := Find_Corresponding_Spec (N);
3063 -- Case of Renaming_As_Body
3065 if Present (Rename_Spec) then
3066 Check_Previous_Null_Procedure (N, Rename_Spec);
3068 -- Renaming declaration is the completion of the declaration of
3069 -- Rename_Spec. We build an actual body for it at the freezing point.
3071 Set_Corresponding_Spec (N, Rename_Spec);
3073 -- Deal with special case of stream functions of abstract types
3076 if Nkind (Unit_Declaration_Node (Rename_Spec)) =
3077 N_Abstract_Subprogram_Declaration
3079 -- Input stream functions are abstract if the object type is
3080 -- abstract. Similarly, all default stream functions for an
3081 -- interface type are abstract. However, these subprograms may
3082 -- receive explicit declarations in representation clauses, making
3083 -- the attribute subprograms usable as defaults in subsequent
3085 -- In this case we rewrite the declaration to make the subprogram
3086 -- non-abstract. We remove the previous declaration, and insert
3087 -- the new one at the point of the renaming, to prevent premature
3088 -- access to unfrozen types. The new declaration reuses the
3089 -- specification of the previous one, and must not be analyzed.
3092 (Is_Primitive (Entity (Nam))
3094 Is_Abstract_Type (Find_Dispatching_Type (Entity (Nam))));
3096 Old_Decl : constant Node_Id :=
3097 Unit_Declaration_Node (Rename_Spec);
3098 New_Decl : constant Node_Id :=
3099 Make_Subprogram_Declaration (Sloc (N),
3101 Relocate_Node (Specification (Old_Decl)));
3104 Insert_After (N, New_Decl);
3105 Set_Is_Abstract_Subprogram (Rename_Spec, False);
3106 Set_Analyzed (New_Decl);
3110 Set_Corresponding_Body (Unit_Declaration_Node (Rename_Spec), New_S);
3112 if Ada_Version = Ada_83 and then Comes_From_Source (N) then
3113 Error_Msg_N ("(Ada 83) renaming cannot serve as a body", N);
3116 Set_Convention (New_S, Convention (Rename_Spec));
3117 Check_Fully_Conformant (New_S, Rename_Spec);
3118 Set_Public_Status (New_S);
3120 if No_Return (Rename_Spec)
3121 and then not No_Return (Entity (Nam))
3124 ("renamed subprogram & must be No_Return", N, Entity (Nam));
3126 ("\since renaming subprogram is No_Return (RM 6.5.1(7/2))", N);
3129 -- The specification does not introduce new formals, but only
3130 -- repeats the formals of the original subprogram declaration.
3131 -- For cross-reference purposes, and for refactoring tools, we
3132 -- treat the formals of the renaming declaration as body formals.
3134 Reference_Body_Formals (Rename_Spec, New_S);
3136 -- Indicate that the entity in the declaration functions like the
3137 -- corresponding body, and is not a new entity. The body will be
3138 -- constructed later at the freeze point, so indicate that the
3139 -- completion has not been seen yet.
3141 Set_Ekind (New_S, E_Subprogram_Body);
3142 New_S := Rename_Spec;
3143 Set_Has_Completion (Rename_Spec, False);
3145 -- Ada 2005: check overriding indicator
3147 if Present (Overridden_Operation (Rename_Spec)) then
3148 if Must_Not_Override (Specification (N)) then
3150 ("subprogram& overrides inherited operation",
3154 and then not Must_Override (Specification (N))
3156 Style.Missing_Overriding (N, Rename_Spec);
3159 elsif Must_Override (Specification (N)) then
3160 Error_Msg_NE ("subprogram& is not overriding", N, Rename_Spec);
3163 -- Normal subprogram renaming (not renaming as body)
3166 Generate_Definition (New_S);
3167 New_Overloaded_Entity (New_S);
3169 if not (Is_Entity_Name (Nam)
3170 and then Is_Intrinsic_Subprogram (Entity (Nam)))
3172 Check_Delayed_Subprogram (New_S);
3175 -- Verify that a SPARK renaming does not declare a primitive
3176 -- operation of a tagged type.
3178 Check_SPARK_Primitive_Operation (New_S);
3181 -- There is no need for elaboration checks on the new entity, which may
3182 -- be called before the next freezing point where the body will appear.
3183 -- Elaboration checks refer to the real entity, not the one created by
3184 -- the renaming declaration.
3186 Set_Kill_Elaboration_Checks (New_S, True);
3188 -- If we had a previous error, indicate a completion is present to stop
3189 -- junk cascaded messages, but don't take any further action.
3191 if Etype (Nam) = Any_Type then
3192 Set_Has_Completion (New_S);
3195 -- Case where name has the form of a selected component
3197 elsif Nkind (Nam) = N_Selected_Component then
3199 -- A name which has the form A.B can designate an entry of task A, a
3200 -- protected operation of protected object A, or finally a primitive
3201 -- operation of object A. In the later case, A is an object of some
3202 -- tagged type, or an access type that denotes one such. To further
3203 -- distinguish these cases, note that the scope of a task entry or
3204 -- protected operation is type of the prefix.
3206 -- The prefix could be an overloaded function call that returns both
3207 -- kinds of operations. This overloading pathology is left to the
3208 -- dedicated reader ???
3211 T : constant Entity_Id := Etype (Prefix (Nam));
3219 and then Is_Tagged_Type (Designated_Type (T))))
3220 and then Scope (Entity (Selector_Name (Nam))) /= T
3222 Analyze_Renamed_Primitive_Operation
3223 (N, New_S, Present (Rename_Spec));
3227 -- Renamed entity is an entry or protected operation. For those
3228 -- cases an explicit body is built (at the point of freezing of
3229 -- this entity) that contains a call to the renamed entity.
3231 -- This is not allowed for renaming as body if the renamed
3232 -- spec is already frozen (see RM 8.5.4(5) for details).
3234 if Present (Rename_Spec) and then Is_Frozen (Rename_Spec) then
3236 ("renaming-as-body cannot rename entry as subprogram", N);
3238 ("\since & is already frozen (RM 8.5.4(5))",
3241 Analyze_Renamed_Entry (N, New_S, Present (Rename_Spec));
3248 -- Case where name is an explicit dereference X.all
3250 elsif Nkind (Nam) = N_Explicit_Dereference then
3252 -- Renamed entity is designated by access_to_subprogram expression.
3253 -- Must build body to encapsulate call, as in the entry case.
3255 Analyze_Renamed_Dereference (N, New_S, Present (Rename_Spec));
3258 -- Indexed component
3260 elsif Nkind (Nam) = N_Indexed_Component then
3261 Analyze_Renamed_Family_Member (N, New_S, Present (Rename_Spec));
3264 -- Character literal
3266 elsif Nkind (Nam) = N_Character_Literal then
3267 Analyze_Renamed_Character (N, New_S, Present (Rename_Spec));
3270 -- Only remaining case is where we have a non-entity name, or a renaming
3271 -- of some other non-overloadable entity.
3273 elsif not Is_Entity_Name (Nam)
3274 or else not Is_Overloadable (Entity (Nam))
3276 -- Do not mention the renaming if it comes from an instance
3278 if not Is_Actual then
3279 Error_Msg_N ("expect valid subprogram name in renaming", N);
3281 Error_Msg_NE ("no visible subprogram for formal&", N, Nam);
3287 -- Find the renamed entity that matches the given specification. Disable
3288 -- Ada_83 because there is no requirement of full conformance between
3289 -- renamed entity and new entity, even though the same circuit is used.
3291 -- This is a bit of an odd case, which introduces a really irregular use
3292 -- of Ada_Version[_Explicit]. Would be nice to find cleaner way to do
3295 Ada_Version := Ada_Version_Type'Max (Ada_Version, Ada_95);
3296 Ada_Version_Pragma := Empty;
3297 Ada_Version_Explicit := Ada_Version;
3300 Old_S := Find_Renamed_Entity (N, Name (N), New_S, Is_Actual);
3302 -- The visible operation may be an inherited abstract operation that
3303 -- was overridden in the private part, in which case a call will
3304 -- dispatch to the overriding operation. Use the overriding one in
3305 -- the renaming declaration, to prevent spurious errors below.
3307 if Is_Overloadable (Old_S)
3308 and then Is_Abstract_Subprogram (Old_S)
3309 and then No (DTC_Entity (Old_S))
3310 and then Present (Alias (Old_S))
3311 and then not Is_Abstract_Subprogram (Alias (Old_S))
3312 and then Present (Overridden_Operation (Alias (Old_S)))
3314 Old_S := Alias (Old_S);
3317 -- When the renamed subprogram is overloaded and used as an actual
3318 -- of a generic, its entity is set to the first available homonym.
3319 -- We must first disambiguate the name, then set the proper entity.
3321 if Is_Actual and then Is_Overloaded (Nam) then
3322 Set_Entity (Nam, Old_S);
3326 -- Most common case: subprogram renames subprogram. No body is generated
3327 -- in this case, so we must indicate the declaration is complete as is.
3328 -- and inherit various attributes of the renamed subprogram.
3330 if No (Rename_Spec) then
3331 Set_Has_Completion (New_S);
3332 Set_Is_Imported (New_S, Is_Imported (Entity (Nam)));
3333 Set_Is_Pure (New_S, Is_Pure (Entity (Nam)));
3334 Set_Is_Preelaborated (New_S, Is_Preelaborated (Entity (Nam)));
3336 -- Ada 2005 (AI-423): Check the consistency of null exclusions
3337 -- between a subprogram and its correct renaming.
3339 -- Note: the Any_Id check is a guard that prevents compiler crashes
3340 -- when performing a null exclusion check between a renaming and a
3341 -- renamed subprogram that has been found to be illegal.
3343 if Ada_Version >= Ada_2005 and then Entity (Nam) /= Any_Id then
3344 Check_Null_Exclusion
3346 Sub => Entity (Nam));
3349 -- Enforce the Ada 2005 rule that the renamed entity cannot require
3350 -- overriding. The flag Requires_Overriding is set very selectively
3351 -- and misses some other illegal cases. The additional conditions
3352 -- checked below are sufficient but not necessary ???
3354 -- The rule does not apply to the renaming generated for an actual
3355 -- subprogram in an instance.
3360 -- Guard against previous errors, and omit renamings of predefined
3363 elsif not Ekind_In (Old_S, E_Function, E_Procedure) then
3366 elsif Requires_Overriding (Old_S)
3368 (Is_Abstract_Subprogram (Old_S)
3369 and then Present (Find_Dispatching_Type (Old_S))
3370 and then not Is_Abstract_Type (Find_Dispatching_Type (Old_S)))
3373 ("renamed entity cannot be subprogram that requires overriding "
3374 & "(RM 8.5.4 (5.1))", N);
3378 Prev : constant Entity_Id := Overridden_Operation (New_S);
3382 (Has_Non_Trivial_Precondition (Prev)
3383 or else Has_Non_Trivial_Precondition (Old_S))
3386 ("conflicting inherited classwide preconditions in renaming "
3387 & "of& (RM 6.1.1 (17)", N, Old_S);
3392 if Old_S /= Any_Id then
3393 if Is_Actual and then From_Default (N) then
3395 -- This is an implicit reference to the default actual
3397 Generate_Reference (Old_S, Nam, Typ => 'i', Force => True);
3400 Generate_Reference (Old_S, Nam);
3403 Check_Internal_Protected_Use (N, Old_S);
3405 -- For a renaming-as-body, require subtype conformance, but if the
3406 -- declaration being completed has not been frozen, then inherit the
3407 -- convention of the renamed subprogram prior to checking conformance
3408 -- (unless the renaming has an explicit convention established; the
3409 -- rule stated in the RM doesn't seem to address this ???).
3411 if Present (Rename_Spec) then
3412 Generate_Reference (Rename_Spec, Defining_Entity (Spec), 'b');
3413 Style.Check_Identifier (Defining_Entity (Spec), Rename_Spec);
3415 if not Is_Frozen (Rename_Spec) then
3416 if not Has_Convention_Pragma (Rename_Spec) then
3417 Set_Convention (New_S, Convention (Old_S));
3420 if Ekind (Old_S) /= E_Operator then
3421 Check_Mode_Conformant (New_S, Old_S, Spec);
3424 if Original_Subprogram (Old_S) = Rename_Spec then
3425 Error_Msg_N ("unfrozen subprogram cannot rename itself ", N);
3427 Check_Formal_Subprogram_Conformance (New_S, Old_S, Spec);
3430 Check_Subtype_Conformant (New_S, Old_S, Spec);
3433 Check_Frozen_Renaming (N, Rename_Spec);
3435 -- Check explicitly that renamed entity is not intrinsic, because
3436 -- in a generic the renamed body is not built. In this case,
3437 -- the renaming_as_body is a completion.
3439 if Inside_A_Generic then
3440 if Is_Frozen (Rename_Spec)
3441 and then Is_Intrinsic_Subprogram (Old_S)
3444 ("subprogram in renaming_as_body cannot be intrinsic",
3448 Set_Has_Completion (Rename_Spec);
3451 elsif Ekind (Old_S) /= E_Operator then
3453 -- If this a defaulted subprogram for a class-wide actual there is
3454 -- no check for mode conformance, given that the signatures don't
3455 -- match (the source mentions T but the actual mentions T'Class).
3460 -- No need for a redundant error message if this is a nested
3461 -- instance, unless the current instantiation (of a child unit)
3462 -- is a compilation unit, which is not analyzed when the parent
3463 -- generic is analyzed.
3466 or else No (Enclosing_Instance)
3467 or else Is_Compilation_Unit (Current_Scope)
3469 Check_Mode_Conformant (New_S, Old_S);
3473 if No (Rename_Spec) then
3475 -- The parameter profile of the new entity is that of the renamed
3476 -- entity: the subtypes given in the specification are irrelevant.
3478 Inherit_Renamed_Profile (New_S, Old_S);
3480 -- A call to the subprogram is transformed into a call to the
3481 -- renamed entity. This is transitive if the renamed entity is
3482 -- itself a renaming.
3484 if Present (Alias (Old_S)) then
3485 Set_Alias (New_S, Alias (Old_S));
3487 Set_Alias (New_S, Old_S);
3490 -- Note that we do not set Is_Intrinsic_Subprogram if we have a
3491 -- renaming as body, since the entity in this case is not an
3492 -- intrinsic (it calls an intrinsic, but we have a real body for
3493 -- this call, and it is in this body that the required intrinsic
3494 -- processing will take place).
3496 -- Also, if this is a renaming of inequality, the renamed operator
3497 -- is intrinsic, but what matters is the corresponding equality
3498 -- operator, which may be user-defined.
3500 Set_Is_Intrinsic_Subprogram
3502 Is_Intrinsic_Subprogram (Old_S)
3504 (Chars (Old_S) /= Name_Op_Ne
3505 or else Ekind (Old_S) = E_Operator
3506 or else Is_Intrinsic_Subprogram
3507 (Corresponding_Equality (Old_S))));
3509 if Ekind (Alias (New_S)) = E_Operator then
3510 Set_Has_Delayed_Freeze (New_S, False);
3513 -- If the renaming corresponds to an association for an abstract
3514 -- formal subprogram, then various attributes must be set to
3515 -- indicate that the renaming is an abstract dispatching operation
3516 -- with a controlling type.
3518 if Is_Actual and then Is_Abstract_Subprogram (Formal_Spec) then
3520 -- Mark the renaming as abstract here, so Find_Dispatching_Type
3521 -- see it as corresponding to a generic association for a
3522 -- formal abstract subprogram
3524 Set_Is_Abstract_Subprogram (New_S);
3527 New_S_Ctrl_Type : constant Entity_Id :=
3528 Find_Dispatching_Type (New_S);
3529 Old_S_Ctrl_Type : constant Entity_Id :=
3530 Find_Dispatching_Type (Old_S);
3534 -- The actual must match the (instance of the) formal,
3535 -- and must be a controlling type.
3537 if Old_S_Ctrl_Type /= New_S_Ctrl_Type
3538 or else No (New_S_Ctrl_Type)
3540 if No (New_S_Ctrl_Type) then
3542 ("actual must be dispatching subprogram", Nam);
3545 ("actual must be dispatching subprogram for type&",
3546 Nam, New_S_Ctrl_Type);
3550 Set_Is_Dispatching_Operation (New_S);
3551 Check_Controlling_Formals (New_S_Ctrl_Type, New_S);
3553 -- If the actual in the formal subprogram is itself a
3554 -- formal abstract subprogram association, there's no
3555 -- dispatch table component or position to inherit.
3557 if Present (DTC_Entity (Old_S)) then
3558 Set_DTC_Entity (New_S, DTC_Entity (Old_S));
3559 Set_DT_Position_Value (New_S, DT_Position (Old_S));
3569 -- The following is illegal, because F hides whatever other F may
3571 -- function F (...) renames F;
3574 or else (Nkind (Nam) /= N_Expanded_Name
3575 and then Chars (Old_S) = Chars (New_S))
3577 Error_Msg_N ("subprogram cannot rename itself", N);
3579 -- This is illegal even if we use a selector:
3580 -- function F (...) renames Pkg.F;
3581 -- because F is still hidden.
3583 elsif Nkind (Nam) = N_Expanded_Name
3584 and then Entity (Prefix (Nam)) = Current_Scope
3585 and then Chars (Selector_Name (Nam)) = Chars (New_S)
3587 -- This is an error, but we overlook the error and accept the
3588 -- renaming if the special Overriding_Renamings mode is in effect.
3590 if not Overriding_Renamings then
3592 ("implicit operation& is not visible (RM 8.3 (15))",
3597 Set_Convention (New_S, Convention (Old_S));
3599 if Is_Abstract_Subprogram (Old_S) then
3600 if Present (Rename_Spec) then
3602 ("a renaming-as-body cannot rename an abstract subprogram",
3604 Set_Has_Completion (Rename_Spec);
3606 Set_Is_Abstract_Subprogram (New_S);
3610 Check_Library_Unit_Renaming (N, Old_S);
3612 -- Pathological case: procedure renames entry in the scope of its
3613 -- task. Entry is given by simple name, but body must be built for
3614 -- procedure. Of course if called it will deadlock.
3616 if Ekind (Old_S) = E_Entry then
3617 Set_Has_Completion (New_S, False);
3618 Set_Alias (New_S, Empty);
3621 -- Do not freeze the renaming nor the renamed entity when the context
3622 -- is an enclosing generic. Freezing is an expansion activity, and in
3623 -- addition the renamed entity may depend on the generic formals of
3624 -- the enclosing generic.
3626 if Is_Actual and not Inside_A_Generic then
3627 Freeze_Before (N, Old_S);
3628 Freeze_Actual_Profile;
3629 Set_Has_Delayed_Freeze (New_S, False);
3630 Freeze_Before (N, New_S);
3632 -- An abstract subprogram is only allowed as an actual in the case
3633 -- where the formal subprogram is also abstract.
3635 if (Ekind (Old_S) = E_Procedure or else Ekind (Old_S) = E_Function)
3636 and then Is_Abstract_Subprogram (Old_S)
3637 and then not Is_Abstract_Subprogram (Formal_Spec)
3640 ("abstract subprogram not allowed as generic actual", Nam);
3645 -- A common error is to assume that implicit operators for types are
3646 -- defined in Standard, or in the scope of a subtype. In those cases
3647 -- where the renamed entity is given with an expanded name, it is
3648 -- worth mentioning that operators for the type are not declared in
3649 -- the scope given by the prefix.
3651 if Nkind (Nam) = N_Expanded_Name
3652 and then Nkind (Selector_Name (Nam)) = N_Operator_Symbol
3653 and then Scope (Entity (Nam)) = Standard_Standard
3656 T : constant Entity_Id :=
3657 Base_Type (Etype (First_Formal (New_S)));
3659 Error_Msg_Node_2 := Prefix (Nam);
3661 ("operator for type& is not declared in&", Prefix (Nam), T);
3666 ("no visible subprogram matches the specification for&",
3670 if Present (Candidate_Renaming) then
3677 F1 := First_Formal (Candidate_Renaming);
3678 F2 := First_Formal (New_S);
3679 T1 := First_Subtype (Etype (F1));
3680 while Present (F1) and then Present (F2) loop
3685 if Present (F1) and then Present (Default_Value (F1)) then
3686 if Present (Next_Formal (F1)) then
3688 ("\missing specification for & and other formals with "
3689 & "defaults", Spec, F1);
3691 Error_Msg_NE ("\missing specification for &", Spec, F1);
3695 if Nkind (Nam) = N_Operator_Symbol
3696 and then From_Default (N)
3698 Error_Msg_Node_2 := T1;
3700 ("default & on & is not directly visible", Nam, Nam);
3706 -- Ada 2005 AI 404: if the new subprogram is dispatching, verify that
3707 -- controlling access parameters are known non-null for the renamed
3708 -- subprogram. Test also applies to a subprogram instantiation that
3709 -- is dispatching. Test is skipped if some previous error was detected
3710 -- that set Old_S to Any_Id.
3712 if Ada_Version >= Ada_2005
3713 and then Old_S /= Any_Id
3714 and then not Is_Dispatching_Operation (Old_S)
3715 and then Is_Dispatching_Operation (New_S)
3722 Old_F := First_Formal (Old_S);
3723 New_F := First_Formal (New_S);
3724 while Present (Old_F) loop
3725 if Ekind (Etype (Old_F)) = E_Anonymous_Access_Type
3726 and then Is_Controlling_Formal (New_F)
3727 and then not Can_Never_Be_Null (Old_F)
3729 Error_Msg_N ("access parameter is controlling,", New_F);
3731 ("\corresponding parameter of& must be explicitly null "
3732 & "excluding", New_F, Old_S);
3735 Next_Formal (Old_F);
3736 Next_Formal (New_F);
3741 -- A useful warning, suggested by Ada Bug Finder (Ada-Europe 2005)
3742 -- is to warn if an operator is being renamed as a different operator.
3743 -- If the operator is predefined, examine the kind of the entity, not
3744 -- the abbreviated declaration in Standard.
3746 if Comes_From_Source (N)
3747 and then Present (Old_S)
3748 and then (Nkind (Old_S) = N_Defining_Operator_Symbol
3749 or else Ekind (Old_S) = E_Operator)
3750 and then Nkind (New_S) = N_Defining_Operator_Symbol
3751 and then Chars (Old_S) /= Chars (New_S)
3754 ("& is being renamed as a different operator??", N, Old_S);
3757 -- Check for renaming of obsolescent subprogram
3759 Check_Obsolescent_2005_Entity (Entity (Nam), Nam);
3761 -- Another warning or some utility: if the new subprogram as the same
3762 -- name as the old one, the old one is not hidden by an outer homograph,
3763 -- the new one is not a public symbol, and the old one is otherwise
3764 -- directly visible, the renaming is superfluous.
3766 if Chars (Old_S) = Chars (New_S)
3767 and then Comes_From_Source (N)
3768 and then Scope (Old_S) /= Standard_Standard
3769 and then Warn_On_Redundant_Constructs
3770 and then (Is_Immediately_Visible (Old_S)
3771 or else Is_Potentially_Use_Visible (Old_S))
3772 and then Is_Overloadable (Current_Scope)
3773 and then Chars (Current_Scope) /= Chars (Old_S)
3776 ("redundant renaming, entity is directly visible?r?", Name (N));
3779 -- Implementation-defined aspect specifications can appear in a renaming
3780 -- declaration, but not language-defined ones. The call to procedure
3781 -- Analyze_Aspect_Specifications will take care of this error check.
3783 if Has_Aspects (N) then
3784 Analyze_Aspect_Specifications (N, New_S);
3790 and then Has_Yield_Aspect (Formal_Spec)
3791 and then not Has_Yield_Aspect (Old_S)
3793 Error_Msg_Name_1 := Name_Yield;
3795 ("actual subprogram& must have aspect% to match formal", Name (N));
3798 Ada_Version := Save_AV;
3799 Ada_Version_Pragma := Save_AVP;
3800 Ada_Version_Explicit := Save_AV_Exp;
3802 -- In GNATprove mode, the renamings of actual subprograms are replaced
3803 -- with wrapper functions that make it easier to propagate axioms to the
3804 -- points of call within an instance. Wrappers are generated if formal
3805 -- subprogram is subject to axiomatization.
3807 -- The types in the wrapper profiles are obtained from (instances of)
3808 -- the types of the formal subprogram.
3811 and then GNATprove_Mode
3812 and then Present (Containing_Package_With_Ext_Axioms (Formal_Spec))
3813 and then not Inside_A_Generic
3815 if Ekind (Old_S) = E_Function then
3816 Rewrite (N, Build_Function_Wrapper (Formal_Spec, Old_S));
3819 elsif Ekind (Old_S) = E_Operator then
3820 Rewrite (N, Build_Operator_Wrapper (Formal_Spec, Old_S));
3825 -- Check if we are looking at an Ada 2012 defaulted formal subprogram
3826 -- and mark any use_package_clauses that affect the visibility of the
3827 -- implicit generic actual.
3829 -- Also, we may be looking at an internal renaming of a user-defined
3830 -- subprogram created for a generic formal subprogram association,
3831 -- which will also have to be marked here. This can occur when the
3832 -- corresponding formal subprogram contains references to other generic
3835 if Is_Generic_Actual_Subprogram (New_S)
3836 and then (Is_Intrinsic_Subprogram (New_S)
3837 or else From_Default (N)
3838 or else Nkind (N) = N_Subprogram_Renaming_Declaration)
3840 Mark_Use_Clauses (New_S);
3842 -- Handle overloaded subprograms
3844 if Present (Alias (New_S)) then
3845 Mark_Use_Clauses (Alias (New_S));
3848 end Analyze_Subprogram_Renaming;
3850 -------------------------
3851 -- Analyze_Use_Package --
3852 -------------------------
3854 -- Resolve the package names in the use clause, and make all the visible
3855 -- entities defined in the package potentially use-visible. If the package
3856 -- is already in use from a previous use clause, its visible entities are
3857 -- already use-visible. In that case, mark the occurrence as a redundant
3858 -- use. If the package is an open scope, i.e. if the use clause occurs
3859 -- within the package itself, ignore it.
3861 procedure Analyze_Use_Package (N : Node_Id; Chain : Boolean := True) is
3862 procedure Analyze_Package_Name (Clause : Node_Id);
3863 -- Perform analysis on a package name from a use_package_clause
3865 procedure Analyze_Package_Name_List (Head_Clause : Node_Id);
3866 -- Similar to Analyze_Package_Name but iterates over all the names
3869 --------------------------
3870 -- Analyze_Package_Name --
3871 --------------------------
3873 procedure Analyze_Package_Name (Clause : Node_Id) is
3874 Pack : constant Node_Id := Name (Clause);
3878 pragma Assert (Nkind (Clause) = N_Use_Package_Clause);
3881 -- Verify that the package standard is not directly named in a
3882 -- use_package_clause.
3884 if Nkind (Parent (Clause)) = N_Compilation_Unit
3885 and then Nkind (Pack) = N_Expanded_Name
3887 Pref := Prefix (Pack);
3889 while Nkind (Pref) = N_Expanded_Name loop
3890 Pref := Prefix (Pref);
3893 if Entity (Pref) = Standard_Standard then
3895 ("predefined package Standard cannot appear in a context "
3899 end Analyze_Package_Name;
3901 -------------------------------
3902 -- Analyze_Package_Name_List --
3903 -------------------------------
3905 procedure Analyze_Package_Name_List (Head_Clause : Node_Id) is
3909 -- Due to the way source use clauses are split during parsing we are
3910 -- forced to simply iterate through all entities in scope until the
3911 -- clause representing the last name in the list is found.
3913 Curr := Head_Clause;
3914 while Present (Curr) loop
3915 Analyze_Package_Name (Curr);
3917 -- Stop iterating over the names in the use clause when we are at
3920 exit when not More_Ids (Curr) and then Prev_Ids (Curr);
3923 end Analyze_Package_Name_List;
3929 -- Start of processing for Analyze_Use_Package
3932 Set_Hidden_By_Use_Clause (N, No_Elist);
3934 -- Use clause not allowed in a spec of a predefined package declaration
3935 -- except that packages whose file name starts a-n are OK (these are
3936 -- children of Ada.Numerics, which are never loaded by Rtsfind).
3938 if Is_Predefined_Unit (Current_Sem_Unit)
3939 and then Get_Name_String
3940 (Unit_File_Name (Current_Sem_Unit)) (1 .. 3) /= "a-n"
3941 and then Nkind (Unit (Cunit (Current_Sem_Unit))) =
3942 N_Package_Declaration
3944 Error_Msg_N ("use clause not allowed in predefined spec", N);
3947 -- Loop through all package names from the original use clause in
3948 -- order to analyze referenced packages. A use_package_clause with only
3949 -- one name does not have More_Ids or Prev_Ids set, while a clause with
3950 -- More_Ids only starts the chain produced by the parser.
3952 if not More_Ids (N) and then not Prev_Ids (N) then
3953 Analyze_Package_Name (N);
3955 elsif More_Ids (N) and then not Prev_Ids (N) then
3956 Analyze_Package_Name_List (N);
3959 if not Is_Entity_Name (Name (N)) then
3960 Error_Msg_N ("& is not a package", Name (N));
3966 Chain_Use_Clause (N);
3969 Pack := Entity (Name (N));
3971 -- There are many cases where scopes are manipulated during analysis, so
3972 -- check that Pack's current use clause has not already been chained
3973 -- before setting its previous use clause.
3975 if Ekind (Pack) = E_Package
3976 and then Present (Current_Use_Clause (Pack))
3977 and then Current_Use_Clause (Pack) /= N
3978 and then No (Prev_Use_Clause (N))
3979 and then Prev_Use_Clause (Current_Use_Clause (Pack)) /= N
3981 Set_Prev_Use_Clause (N, Current_Use_Clause (Pack));
3984 -- Mark all entities as potentially use visible.
3986 if Ekind (Pack) /= E_Package and then Etype (Pack) /= Any_Type then
3987 if Ekind (Pack) = E_Generic_Package then
3988 Error_Msg_N -- CODEFIX
3989 ("a generic package is not allowed in a use clause", Name (N));
3991 elsif Ekind_In (Pack, E_Generic_Function, E_Generic_Package)
3993 Error_Msg_N -- CODEFIX
3994 ("a generic subprogram is not allowed in a use clause",
3997 elsif Ekind_In (Pack, E_Function, E_Procedure, E_Operator) then
3998 Error_Msg_N -- CODEFIX
3999 ("a subprogram is not allowed in a use clause", Name (N));
4002 Error_Msg_N ("& is not allowed in a use clause", Name (N));
4006 if Nkind (Parent (N)) = N_Compilation_Unit then
4007 Check_In_Previous_With_Clause (N, Name (N));
4010 Use_One_Package (N, Name (N));
4013 Mark_Ghost_Clause (N);
4014 end Analyze_Use_Package;
4016 ----------------------
4017 -- Analyze_Use_Type --
4018 ----------------------
4020 procedure Analyze_Use_Type (N : Node_Id; Chain : Boolean := True) is
4025 Set_Hidden_By_Use_Clause (N, No_Elist);
4027 -- Chain clause to list of use clauses in current scope when flagged
4030 Chain_Use_Clause (N);
4033 -- Obtain the base type of the type denoted within the use_type_clause's
4036 Id := Subtype_Mark (N);
4038 E := Base_Type (Entity (Id));
4040 -- There are many cases where a use_type_clause may be reanalyzed due to
4041 -- manipulation of the scope stack so we much guard against those cases
4042 -- here, otherwise, we must add the new use_type_clause to the previous
4043 -- use_type_clause chain in order to mark redundant use_type_clauses as
4044 -- used. When the redundant use-type clauses appear in a parent unit and
4045 -- a child unit we must prevent a circularity in the chain that would
4046 -- otherwise result from the separate steps of analysis and installation
4047 -- of the parent context.
4049 if Present (Current_Use_Clause (E))
4050 and then Current_Use_Clause (E) /= N
4051 and then Prev_Use_Clause (Current_Use_Clause (E)) /= N
4052 and then No (Prev_Use_Clause (N))
4054 Set_Prev_Use_Clause (N, Current_Use_Clause (E));
4057 -- If the Used_Operations list is already initialized, the clause has
4058 -- been analyzed previously, and it is being reinstalled, for example
4059 -- when the clause appears in a package spec and we are compiling the
4060 -- corresponding package body. In that case, make the entities on the
4061 -- existing list use_visible, and mark the corresponding types In_Use.
4063 if Present (Used_Operations (N)) then
4068 Use_One_Type (Subtype_Mark (N), Installed => True);
4070 Elmt := First_Elmt (Used_Operations (N));
4071 while Present (Elmt) loop
4072 Set_Is_Potentially_Use_Visible (Node (Elmt));
4080 -- Otherwise, create new list and attach to it the operations that are
4081 -- made use-visible by the clause.
4083 Set_Used_Operations (N, New_Elmt_List);
4086 if E /= Any_Type then
4089 if Nkind (Parent (N)) = N_Compilation_Unit then
4090 if Nkind (Id) = N_Identifier then
4091 Error_Msg_N ("type is not directly visible", Id);
4093 elsif Is_Child_Unit (Scope (E))
4094 and then Scope (E) /= System_Aux_Id
4096 Check_In_Previous_With_Clause (N, Prefix (Id));
4101 -- If the use_type_clause appears in a compilation unit context,
4102 -- check whether it comes from a unit that may appear in a
4103 -- limited_with_clause, for a better error message.
4105 if Nkind (Parent (N)) = N_Compilation_Unit
4106 and then Nkind (Id) /= N_Identifier
4112 function Mentioned (Nam : Node_Id) return Boolean;
4113 -- Check whether the prefix of expanded name for the type
4114 -- appears in the prefix of some limited_with_clause.
4120 function Mentioned (Nam : Node_Id) return Boolean is
4122 return Nkind (Name (Item)) = N_Selected_Component
4123 and then Chars (Prefix (Name (Item))) = Chars (Nam);
4127 Pref := Prefix (Id);
4128 Item := First (Context_Items (Parent (N)));
4129 while Present (Item) and then Item /= N loop
4130 if Nkind (Item) = N_With_Clause
4131 and then Limited_Present (Item)
4132 and then Mentioned (Pref)
4135 (Get_Msg_Id, "premature usage of incomplete type");
4144 Mark_Ghost_Clause (N);
4145 end Analyze_Use_Type;
4147 ------------------------
4148 -- Attribute_Renaming --
4149 ------------------------
4151 procedure Attribute_Renaming (N : Node_Id) is
4152 Loc : constant Source_Ptr := Sloc (N);
4153 Nam : constant Node_Id := Name (N);
4154 Spec : constant Node_Id := Specification (N);
4155 New_S : constant Entity_Id := Defining_Unit_Name (Spec);
4156 Aname : constant Name_Id := Attribute_Name (Nam);
4158 Form_Num : Nat := 0;
4159 Expr_List : List_Id := No_List;
4161 Attr_Node : Node_Id;
4162 Body_Node : Node_Id;
4163 Param_Spec : Node_Id;
4166 Generate_Definition (New_S);
4168 -- This procedure is called in the context of subprogram renaming, and
4169 -- thus the attribute must be one that is a subprogram. All of those
4170 -- have at least one formal parameter, with the exceptions of the GNAT
4171 -- attribute 'Img, which GNAT treats as renameable.
4173 if not Is_Non_Empty_List (Parameter_Specifications (Spec)) then
4174 if Aname /= Name_Img then
4176 ("subprogram renaming an attribute must have formals", N);
4181 Param_Spec := First (Parameter_Specifications (Spec));
4182 while Present (Param_Spec) loop
4183 Form_Num := Form_Num + 1;
4185 if Nkind (Parameter_Type (Param_Spec)) /= N_Access_Definition then
4186 Find_Type (Parameter_Type (Param_Spec));
4188 -- The profile of the new entity denotes the base type (s) of
4189 -- the types given in the specification. For access parameters
4190 -- there are no subtypes involved.
4192 Rewrite (Parameter_Type (Param_Spec),
4194 (Base_Type (Entity (Parameter_Type (Param_Spec))), Loc));
4197 if No (Expr_List) then
4198 Expr_List := New_List;
4201 Append_To (Expr_List,
4202 Make_Identifier (Loc,
4203 Chars => Chars (Defining_Identifier (Param_Spec))));
4205 -- The expressions in the attribute reference are not freeze
4206 -- points. Neither is the attribute as a whole, see below.
4208 Set_Must_Not_Freeze (Last (Expr_List));
4213 -- Immediate error if too many formals. Other mismatches in number or
4214 -- types of parameters are detected when we analyze the body of the
4215 -- subprogram that we construct.
4217 if Form_Num > 2 then
4218 Error_Msg_N ("too many formals for attribute", N);
4220 -- Error if the attribute reference has expressions that look like
4221 -- formal parameters.
4223 elsif Present (Expressions (Nam)) then
4224 Error_Msg_N ("illegal expressions in attribute reference", Nam);
4227 Nam_In (Aname, Name_Compose, Name_Exponent, Name_Leading_Part,
4228 Name_Pos, Name_Round, Name_Scaling,
4231 if Nkind (N) = N_Subprogram_Renaming_Declaration
4232 and then Present (Corresponding_Formal_Spec (N))
4235 ("generic actual cannot be attribute involving universal type",
4239 ("attribute involving a universal type cannot be renamed",
4244 -- Rewrite attribute node to have a list of expressions corresponding to
4245 -- the subprogram formals. A renaming declaration is not a freeze point,
4246 -- and the analysis of the attribute reference should not freeze the
4247 -- type of the prefix. We use the original node in the renaming so that
4248 -- its source location is preserved, and checks on stream attributes are
4249 -- properly applied.
4251 Attr_Node := Relocate_Node (Nam);
4252 Set_Expressions (Attr_Node, Expr_List);
4254 Set_Must_Not_Freeze (Attr_Node);
4255 Set_Must_Not_Freeze (Prefix (Nam));
4257 -- Case of renaming a function
4259 if Nkind (Spec) = N_Function_Specification then
4260 if Is_Procedure_Attribute_Name (Aname) then
4261 Error_Msg_N ("attribute can only be renamed as procedure", Nam);
4265 Find_Type (Result_Definition (Spec));
4266 Rewrite (Result_Definition (Spec),
4268 (Base_Type (Entity (Result_Definition (Spec))), Loc));
4271 Make_Subprogram_Body (Loc,
4272 Specification => Spec,
4273 Declarations => New_List,
4274 Handled_Statement_Sequence =>
4275 Make_Handled_Sequence_Of_Statements (Loc,
4276 Statements => New_List (
4277 Make_Simple_Return_Statement (Loc,
4278 Expression => Attr_Node))));
4280 -- Case of renaming a procedure
4283 if not Is_Procedure_Attribute_Name (Aname) then
4284 Error_Msg_N ("attribute can only be renamed as function", Nam);
4289 Make_Subprogram_Body (Loc,
4290 Specification => Spec,
4291 Declarations => New_List,
4292 Handled_Statement_Sequence =>
4293 Make_Handled_Sequence_Of_Statements (Loc,
4294 Statements => New_List (Attr_Node)));
4297 -- Signal the ABE mechanism that the generated subprogram body has not
4298 -- ABE ramifications.
4300 Set_Was_Attribute_Reference (Body_Node);
4302 -- In case of tagged types we add the body of the generated function to
4303 -- the freezing actions of the type (because in the general case such
4304 -- type is still not frozen). We exclude from this processing generic
4305 -- formal subprograms found in instantiations.
4307 -- We must exclude restricted run-time libraries because
4308 -- entity AST_Handler is defined in package System.Aux_Dec which is not
4309 -- available in those platforms. Note that we cannot use the function
4310 -- Restricted_Profile (instead of Configurable_Run_Time_Mode) because
4311 -- the ZFP run-time library is not defined as a profile, and we do not
4312 -- want to deal with AST_Handler in ZFP mode.
4314 if not Configurable_Run_Time_Mode
4315 and then not Present (Corresponding_Formal_Spec (N))
4316 and then Etype (Nam) /= RTE (RE_AST_Handler)
4319 P : constant Node_Id := Prefix (Nam);
4322 -- The prefix of 'Img is an object that is evaluated for each call
4323 -- of the function that renames it.
4325 if Aname = Name_Img then
4326 Preanalyze_And_Resolve (P);
4328 -- For all other attribute renamings, the prefix is a subtype
4334 -- If the target type is not yet frozen, add the body to the
4335 -- actions to be elaborated at freeze time.
4337 if Is_Tagged_Type (Etype (P))
4338 and then In_Open_Scopes (Scope (Etype (P)))
4340 Ensure_Freeze_Node (Etype (P));
4341 Append_Freeze_Action (Etype (P), Body_Node);
4343 Rewrite (N, Body_Node);
4345 Set_Etype (New_S, Base_Type (Etype (New_S)));
4349 -- Generic formal subprograms or AST_Handler renaming
4352 Rewrite (N, Body_Node);
4354 Set_Etype (New_S, Base_Type (Etype (New_S)));
4357 if Is_Compilation_Unit (New_S) then
4359 ("a library unit can only rename another library unit", N);
4362 -- We suppress elaboration warnings for the resulting entity, since
4363 -- clearly they are not needed, and more particularly, in the case
4364 -- of a generic formal subprogram, the resulting entity can appear
4365 -- after the instantiation itself, and thus look like a bogus case
4366 -- of access before elaboration.
4368 if Legacy_Elaboration_Checks then
4369 Set_Suppress_Elaboration_Warnings (New_S);
4371 end Attribute_Renaming;
4373 ----------------------
4374 -- Chain_Use_Clause --
4375 ----------------------
4377 procedure Chain_Use_Clause (N : Node_Id) is
4378 Level : Int := Scope_Stack.Last;
4384 if not Is_Compilation_Unit (Current_Scope)
4385 or else not Is_Child_Unit (Current_Scope)
4389 -- Common case for compilation unit
4391 elsif Defining_Entity (Parent (N)) = Current_Scope then
4395 -- If declaration appears in some other scope, it must be in some
4396 -- parent unit when compiling a child.
4398 Pack := Defining_Entity (Parent (N));
4400 if not In_Open_Scopes (Pack) then
4403 -- If the use clause appears in an ancestor and we are in the
4404 -- private part of the immediate parent, the use clauses are
4405 -- already installed.
4407 elsif Pack /= Scope (Current_Scope)
4408 and then In_Private_Part (Scope (Current_Scope))
4413 -- Find entry for parent unit in scope stack
4415 while Scope_Stack.Table (Level).Entity /= Pack loop
4421 Set_Next_Use_Clause (N,
4422 Scope_Stack.Table (Level).First_Use_Clause);
4423 Scope_Stack.Table (Level).First_Use_Clause := N;
4424 end Chain_Use_Clause;
4426 ---------------------------
4427 -- Check_Frozen_Renaming --
4428 ---------------------------
4430 procedure Check_Frozen_Renaming (N : Node_Id; Subp : Entity_Id) is
4435 if Is_Frozen (Subp) and then not Has_Completion (Subp) then
4438 (Parent (Declaration_Node (Subp)), Defining_Entity (N));
4440 if Is_Entity_Name (Name (N)) then
4441 Old_S := Entity (Name (N));
4443 if not Is_Frozen (Old_S)
4444 and then Operating_Mode /= Check_Semantics
4446 Append_Freeze_Action (Old_S, B_Node);
4448 Insert_After (N, B_Node);
4452 if Is_Intrinsic_Subprogram (Old_S)
4453 and then not In_Instance
4454 and then not Relaxed_RM_Semantics
4457 ("subprogram used in renaming_as_body cannot be intrinsic",
4462 Insert_After (N, B_Node);
4466 end Check_Frozen_Renaming;
4468 -------------------------------
4469 -- Set_Entity_Or_Discriminal --
4470 -------------------------------
4472 procedure Set_Entity_Or_Discriminal (N : Node_Id; E : Entity_Id) is
4476 -- If the entity is not a discriminant, or else expansion is disabled,
4477 -- simply set the entity.
4479 if not In_Spec_Expression
4480 or else Ekind (E) /= E_Discriminant
4481 or else Inside_A_Generic
4483 Set_Entity_With_Checks (N, E);
4485 -- The replacement of a discriminant by the corresponding discriminal
4486 -- is not done for a task discriminant that appears in a default
4487 -- expression of an entry parameter. See Exp_Ch2.Expand_Discriminant
4488 -- for details on their handling.
4490 elsif Is_Concurrent_Type (Scope (E)) then
4493 and then not Nkind_In (P, N_Parameter_Specification,
4494 N_Component_Declaration)
4500 and then Nkind (P) = N_Parameter_Specification
4505 Set_Entity (N, Discriminal (E));
4508 -- Otherwise, this is a discriminant in a context in which
4509 -- it is a reference to the corresponding parameter of the
4510 -- init proc for the enclosing type.
4513 Set_Entity (N, Discriminal (E));
4515 end Set_Entity_Or_Discriminal;
4517 -----------------------------------
4518 -- Check_In_Previous_With_Clause --
4519 -----------------------------------
4521 procedure Check_In_Previous_With_Clause
4525 Pack : constant Entity_Id := Entity (Original_Node (Nam));
4530 Item := First (Context_Items (Parent (N)));
4531 while Present (Item) and then Item /= N loop
4532 if Nkind (Item) = N_With_Clause
4534 -- Protect the frontend against previous critical errors
4536 and then Nkind (Name (Item)) /= N_Selected_Component
4537 and then Entity (Name (Item)) = Pack
4541 -- Find root library unit in with_clause
4543 while Nkind (Par) = N_Expanded_Name loop
4544 Par := Prefix (Par);
4547 if Is_Child_Unit (Entity (Original_Node (Par))) then
4548 Error_Msg_NE ("& is not directly visible", Par, Entity (Par));
4557 -- On exit, package is not mentioned in a previous with_clause.
4558 -- Check if its prefix is.
4560 if Nkind (Nam) = N_Expanded_Name then
4561 Check_In_Previous_With_Clause (N, Prefix (Nam));
4563 elsif Pack /= Any_Id then
4564 Error_Msg_NE ("& is not visible", Nam, Pack);
4566 end Check_In_Previous_With_Clause;
4568 ---------------------------------
4569 -- Check_Library_Unit_Renaming --
4570 ---------------------------------
4572 procedure Check_Library_Unit_Renaming (N : Node_Id; Old_E : Entity_Id) is
4576 if Nkind (Parent (N)) /= N_Compilation_Unit then
4579 -- Check for library unit. Note that we used to check for the scope
4580 -- being Standard here, but that was wrong for Standard itself.
4582 elsif not Is_Compilation_Unit (Old_E)
4583 and then not Is_Child_Unit (Old_E)
4585 Error_Msg_N ("renamed unit must be a library unit", Name (N));
4587 -- Entities defined in Standard (operators and boolean literals) cannot
4588 -- be renamed as library units.
4590 elsif Scope (Old_E) = Standard_Standard
4591 and then Sloc (Old_E) = Standard_Location
4593 Error_Msg_N ("renamed unit must be a library unit", Name (N));
4595 elsif Present (Parent_Spec (N))
4596 and then Nkind (Unit (Parent_Spec (N))) = N_Generic_Package_Declaration
4597 and then not Is_Child_Unit (Old_E)
4600 ("renamed unit must be a child unit of generic parent", Name (N));
4602 elsif Nkind (N) in N_Generic_Renaming_Declaration
4603 and then Nkind (Name (N)) = N_Expanded_Name
4604 and then Is_Generic_Instance (Entity (Prefix (Name (N))))
4605 and then Is_Generic_Unit (Old_E)
4608 ("renamed generic unit must be a library unit", Name (N));
4610 elsif Is_Package_Or_Generic_Package (Old_E) then
4612 -- Inherit categorization flags
4614 New_E := Defining_Entity (N);
4615 Set_Is_Pure (New_E, Is_Pure (Old_E));
4616 Set_Is_Preelaborated (New_E, Is_Preelaborated (Old_E));
4617 Set_Is_Remote_Call_Interface (New_E,
4618 Is_Remote_Call_Interface (Old_E));
4619 Set_Is_Remote_Types (New_E, Is_Remote_Types (Old_E));
4620 Set_Is_Shared_Passive (New_E, Is_Shared_Passive (Old_E));
4622 end Check_Library_Unit_Renaming;
4624 ------------------------
4625 -- Enclosing_Instance --
4626 ------------------------
4628 function Enclosing_Instance return Entity_Id is
4632 if not Is_Generic_Instance (Current_Scope) then
4636 S := Scope (Current_Scope);
4637 while S /= Standard_Standard loop
4638 if Is_Generic_Instance (S) then
4646 end Enclosing_Instance;
4652 procedure End_Scope is
4658 Id := First_Entity (Current_Scope);
4659 while Present (Id) loop
4660 -- An entity in the current scope is not necessarily the first one
4661 -- on its homonym chain. Find its predecessor if any,
4662 -- If it is an internal entity, it will not be in the visibility
4663 -- chain altogether, and there is nothing to unchain.
4665 if Id /= Current_Entity (Id) then
4666 Prev := Current_Entity (Id);
4667 while Present (Prev)
4668 and then Present (Homonym (Prev))
4669 and then Homonym (Prev) /= Id
4671 Prev := Homonym (Prev);
4674 -- Skip to end of loop if Id is not in the visibility chain
4676 if No (Prev) or else Homonym (Prev) /= Id then
4684 Set_Is_Immediately_Visible (Id, False);
4686 Outer := Homonym (Id);
4687 while Present (Outer) and then Scope (Outer) = Current_Scope loop
4688 Outer := Homonym (Outer);
4691 -- Reset homonym link of other entities, but do not modify link
4692 -- between entities in current scope, so that the back-end can have
4693 -- a proper count of local overloadings.
4696 Set_Name_Entity_Id (Chars (Id), Outer);
4698 elsif Scope (Prev) /= Scope (Id) then
4699 Set_Homonym (Prev, Outer);
4706 -- If the scope generated freeze actions, place them before the
4707 -- current declaration and analyze them. Type declarations and
4708 -- the bodies of initialization procedures can generate such nodes.
4709 -- We follow the parent chain until we reach a list node, which is
4710 -- the enclosing list of declarations. If the list appears within
4711 -- a protected definition, move freeze nodes outside the protected
4715 (Scope_Stack.Table (Scope_Stack.Last).Pending_Freeze_Actions)
4719 L : constant List_Id := Scope_Stack.Table
4720 (Scope_Stack.Last).Pending_Freeze_Actions;
4723 if Is_Itype (Current_Scope) then
4724 Decl := Associated_Node_For_Itype (Current_Scope);
4726 Decl := Parent (Current_Scope);
4731 while not (Is_List_Member (Decl))
4732 or else Nkind_In (Parent (Decl), N_Protected_Definition,
4735 Decl := Parent (Decl);
4738 Insert_List_Before_And_Analyze (Decl, L);
4746 ---------------------
4747 -- End_Use_Clauses --
4748 ---------------------
4750 procedure End_Use_Clauses (Clause : Node_Id) is
4754 -- Remove use_type_clauses first, because they affect the visibility of
4755 -- operators in subsequent used packages.
4758 while Present (U) loop
4759 if Nkind (U) = N_Use_Type_Clause then
4763 Next_Use_Clause (U);
4767 while Present (U) loop
4768 if Nkind (U) = N_Use_Package_Clause then
4769 End_Use_Package (U);
4772 Next_Use_Clause (U);
4774 end End_Use_Clauses;
4776 ---------------------
4777 -- End_Use_Package --
4778 ---------------------
4780 procedure End_Use_Package (N : Node_Id) is
4782 Pack_Name : Node_Id;
4786 function Is_Primitive_Operator_In_Use
4788 F : Entity_Id) return Boolean;
4789 -- Check whether Op is a primitive operator of a use-visible type
4791 ----------------------------------
4792 -- Is_Primitive_Operator_In_Use --
4793 ----------------------------------
4795 function Is_Primitive_Operator_In_Use
4797 F : Entity_Id) return Boolean
4799 T : constant Entity_Id := Base_Type (Etype (F));
4801 return In_Use (T) and then Scope (T) = Scope (Op);
4802 end Is_Primitive_Operator_In_Use;
4804 -- Start of processing for End_Use_Package
4807 Pack_Name := Name (N);
4809 -- Test that Pack_Name actually denotes a package before processing
4811 if Is_Entity_Name (Pack_Name)
4812 and then Ekind (Entity (Pack_Name)) = E_Package
4814 Pack := Entity (Pack_Name);
4816 if In_Open_Scopes (Pack) then
4819 elsif not Redundant_Use (Pack_Name) then
4820 Set_In_Use (Pack, False);
4821 Set_Current_Use_Clause (Pack, Empty);
4823 Id := First_Entity (Pack);
4824 while Present (Id) loop
4826 -- Preserve use-visibility of operators that are primitive
4827 -- operators of a type that is use-visible through an active
4830 if Nkind (Id) = N_Defining_Operator_Symbol
4832 (Is_Primitive_Operator_In_Use (Id, First_Formal (Id))
4834 (Present (Next_Formal (First_Formal (Id)))
4836 Is_Primitive_Operator_In_Use
4837 (Id, Next_Formal (First_Formal (Id)))))
4841 Set_Is_Potentially_Use_Visible (Id, False);
4844 if Is_Private_Type (Id)
4845 and then Present (Full_View (Id))
4847 Set_Is_Potentially_Use_Visible (Full_View (Id), False);
4853 if Present (Renamed_Object (Pack)) then
4854 Set_In_Use (Renamed_Object (Pack), False);
4855 Set_Current_Use_Clause (Renamed_Object (Pack), Empty);
4858 if Chars (Pack) = Name_System
4859 and then Scope (Pack) = Standard_Standard
4860 and then Present_System_Aux
4862 Id := First_Entity (System_Aux_Id);
4863 while Present (Id) loop
4864 Set_Is_Potentially_Use_Visible (Id, False);
4866 if Is_Private_Type (Id)
4867 and then Present (Full_View (Id))
4869 Set_Is_Potentially_Use_Visible (Full_View (Id), False);
4875 Set_In_Use (System_Aux_Id, False);
4878 Set_Redundant_Use (Pack_Name, False);
4882 if Present (Hidden_By_Use_Clause (N)) then
4883 Elmt := First_Elmt (Hidden_By_Use_Clause (N));
4884 while Present (Elmt) loop
4886 E : constant Entity_Id := Node (Elmt);
4889 -- Reset either Use_Visibility or Direct_Visibility, depending
4890 -- on how the entity was hidden by the use clause.
4892 if In_Use (Scope (E))
4893 and then Used_As_Generic_Actual (Scope (E))
4895 Set_Is_Potentially_Use_Visible (Node (Elmt));
4897 Set_Is_Immediately_Visible (Node (Elmt));
4904 Set_Hidden_By_Use_Clause (N, No_Elist);
4906 end End_Use_Package;
4912 procedure End_Use_Type (N : Node_Id) is
4917 -- Start of processing for End_Use_Type
4920 Id := Subtype_Mark (N);
4922 -- A call to Rtsfind may occur while analyzing a use_type_clause, in
4923 -- which case the type marks are not resolved yet, so guard against that
4926 if Is_Entity_Name (Id) and then Present (Entity (Id)) then
4929 if T = Any_Type or else From_Limited_With (T) then
4932 -- Note that the use_type_clause may mention a subtype of the type
4933 -- whose primitive operations have been made visible. Here as
4934 -- elsewhere, it is the base type that matters for visibility.
4936 elsif In_Open_Scopes (Scope (Base_Type (T))) then
4939 elsif not Redundant_Use (Id) then
4940 Set_In_Use (T, False);
4941 Set_In_Use (Base_Type (T), False);
4942 Set_Current_Use_Clause (T, Empty);
4943 Set_Current_Use_Clause (Base_Type (T), Empty);
4945 -- See Use_One_Type for the rationale. This is a bit on the naive
4946 -- side, but should be good enough in practice.
4948 if Is_Tagged_Type (T) then
4949 Set_In_Use (Class_Wide_Type (T), False);
4954 if Is_Empty_Elmt_List (Used_Operations (N)) then
4958 Elmt := First_Elmt (Used_Operations (N));
4959 while Present (Elmt) loop
4960 Set_Is_Potentially_Use_Visible (Node (Elmt), False);
4966 --------------------
4967 -- Entity_Of_Unit --
4968 --------------------
4970 function Entity_Of_Unit (U : Node_Id) return Entity_Id is
4972 if Nkind (U) = N_Package_Instantiation and then Analyzed (U) then
4973 return Defining_Entity (Instance_Spec (U));
4975 return Defining_Entity (U);
4979 ----------------------
4980 -- Find_Direct_Name --
4981 ----------------------
4983 procedure Find_Direct_Name
4985 Errors_OK : Boolean := True;
4986 Marker_OK : Boolean := True;
4987 Reference_OK : Boolean := True)
4993 Homonyms : Entity_Id;
4994 -- Saves start of homonym chain
4996 Inst : Entity_Id := Empty;
4997 -- Enclosing instance, if any
4999 Nvis_Entity : Boolean;
5000 -- Set True to indicate that there is at least one entity on the homonym
5001 -- chain which, while not visible, is visible enough from the user point
5002 -- of view to warrant an error message of "not visible" rather than
5005 Nvis_Is_Private_Subprg : Boolean := False;
5006 -- Ada 2005 (AI-262): Set True to indicate that a form of Beaujolais
5007 -- effect concerning library subprograms has been detected. Used to
5008 -- generate the precise error message.
5010 function From_Actual_Package (E : Entity_Id) return Boolean;
5011 -- Returns true if the entity is an actual for a package that is itself
5012 -- an actual for a formal package of the current instance. Such an
5013 -- entity requires special handling because it may be use-visible but
5014 -- hides directly visible entities defined outside the instance, because
5015 -- the corresponding formal did so in the generic.
5017 function Is_Actual_Parameter return Boolean;
5018 -- This function checks if the node N is an identifier that is an actual
5019 -- parameter of a procedure call. If so it returns True, otherwise it
5020 -- return False. The reason for this check is that at this stage we do
5021 -- not know what procedure is being called if the procedure might be
5022 -- overloaded, so it is premature to go setting referenced flags or
5023 -- making calls to Generate_Reference. We will wait till Resolve_Actuals
5024 -- for that processing
5026 function Known_But_Invisible (E : Entity_Id) return Boolean;
5027 -- This function determines whether a reference to the entity E, which
5028 -- is not visible, can reasonably be considered to be known to the
5029 -- writer of the reference. This is a heuristic test, used only for
5030 -- the purposes of figuring out whether we prefer to complain that an
5031 -- entity is undefined or invisible (and identify the declaration of
5032 -- the invisible entity in the latter case). The point here is that we
5033 -- don't want to complain that something is invisible and then point to
5034 -- something entirely mysterious to the writer.
5036 procedure Nvis_Messages;
5037 -- Called if there are no visible entries for N, but there is at least
5038 -- one non-directly visible, or hidden declaration. This procedure
5039 -- outputs an appropriate set of error messages.
5041 procedure Undefined (Nvis : Boolean);
5042 -- This function is called if the current node has no corresponding
5043 -- visible entity or entities. The value set in Msg indicates whether
5044 -- an error message was generated (multiple error messages for the
5045 -- same variable are generally suppressed, see body for details).
5046 -- Msg is True if an error message was generated, False if not. This
5047 -- value is used by the caller to determine whether or not to output
5048 -- additional messages where appropriate. The parameter is set False
5049 -- to get the message "X is undefined", and True to get the message
5050 -- "X is not visible".
5052 -------------------------
5053 -- From_Actual_Package --
5054 -------------------------
5056 function From_Actual_Package (E : Entity_Id) return Boolean is
5057 Scop : constant Entity_Id := Scope (E);
5058 -- Declared scope of candidate entity
5060 function Declared_In_Actual (Pack : Entity_Id) return Boolean;
5061 -- Recursive function that does the work and examines actuals of
5062 -- actual packages of current instance.
5064 ------------------------
5065 -- Declared_In_Actual --
5066 ------------------------
5068 function Declared_In_Actual (Pack : Entity_Id) return Boolean is
5072 if No (Associated_Formal_Package (Pack)) then
5076 Act := First_Entity (Pack);
5077 while Present (Act) loop
5078 if Renamed_Object (Pack) = Scop then
5081 -- Check for end of list of actuals
5083 elsif Ekind (Act) = E_Package
5084 and then Renamed_Object (Act) = Pack
5088 elsif Ekind (Act) = E_Package
5089 and then Declared_In_Actual (Act)
5099 end Declared_In_Actual;
5105 -- Start of processing for From_Actual_Package
5108 if not In_Instance then
5112 Inst := Current_Scope;
5113 while Present (Inst)
5114 and then Ekind (Inst) /= E_Package
5115 and then not Is_Generic_Instance (Inst)
5117 Inst := Scope (Inst);
5124 Act := First_Entity (Inst);
5125 while Present (Act) loop
5126 if Ekind (Act) = E_Package
5127 and then Declared_In_Actual (Act)
5137 end From_Actual_Package;
5139 -------------------------
5140 -- Is_Actual_Parameter --
5141 -------------------------
5143 function Is_Actual_Parameter return Boolean is
5146 Nkind (N) = N_Identifier
5148 (Nkind (Parent (N)) = N_Procedure_Call_Statement
5150 (Nkind (Parent (N)) = N_Parameter_Association
5151 and then N = Explicit_Actual_Parameter (Parent (N))
5152 and then Nkind (Parent (Parent (N))) =
5153 N_Procedure_Call_Statement));
5154 end Is_Actual_Parameter;
5156 -------------------------
5157 -- Known_But_Invisible --
5158 -------------------------
5160 function Known_But_Invisible (E : Entity_Id) return Boolean is
5161 Fname : File_Name_Type;
5164 -- Entities in Standard are always considered to be known
5166 if Sloc (E) <= Standard_Location then
5169 -- An entity that does not come from source is always considered
5170 -- to be unknown, since it is an artifact of code expansion.
5172 elsif not Comes_From_Source (E) then
5175 -- In gnat internal mode, we consider all entities known. The
5176 -- historical reason behind this discrepancy is not known??? But the
5177 -- only effect is to modify the error message given, so it is not
5178 -- critical. Since it only affects the exact wording of error
5179 -- messages in illegal programs, we do not mention this as an
5180 -- effect of -gnatg, since it is not a language modification.
5182 elsif GNAT_Mode then
5186 -- Here we have an entity that is not from package Standard, and
5187 -- which comes from Source. See if it comes from an internal file.
5189 Fname := Unit_File_Name (Get_Source_Unit (E));
5191 -- Case of from internal file
5193 if In_Internal_Unit (E) then
5195 -- Private part entities in internal files are never considered
5196 -- to be known to the writer of normal application code.
5198 if Is_Hidden (E) then
5202 -- Entities from System packages other than System and
5203 -- System.Storage_Elements are not considered to be known.
5204 -- System.Auxxxx files are also considered known to the user.
5206 -- Should refine this at some point to generally distinguish
5207 -- between known and unknown internal files ???
5209 Get_Name_String (Fname);
5214 Name_Buffer (1 .. 2) /= "s-"
5216 Name_Buffer (3 .. 8) = "stoele"
5218 Name_Buffer (3 .. 5) = "aux";
5220 -- If not an internal file, then entity is definitely known, even if
5221 -- it is in a private part (the message generated will note that it
5222 -- is in a private part).
5227 end Known_But_Invisible;
5233 procedure Nvis_Messages is
5234 Comp_Unit : Node_Id;
5236 Found : Boolean := False;
5237 Hidden : Boolean := False;
5241 if not Errors_OK then
5245 -- Ada 2005 (AI-262): Generate a precise error concerning the
5246 -- Beaujolais effect that was previously detected
5248 if Nvis_Is_Private_Subprg then
5250 pragma Assert (Nkind (E2) = N_Defining_Identifier
5251 and then Ekind (E2) = E_Function
5252 and then Scope (E2) = Standard_Standard
5253 and then Has_Private_With (E2));
5255 -- Find the sloc corresponding to the private with'ed unit
5257 Comp_Unit := Cunit (Current_Sem_Unit);
5258 Error_Msg_Sloc := No_Location;
5260 Item := First (Context_Items (Comp_Unit));
5261 while Present (Item) loop
5262 if Nkind (Item) = N_With_Clause
5263 and then Private_Present (Item)
5264 and then Entity (Name (Item)) = E2
5266 Error_Msg_Sloc := Sloc (Item);
5273 pragma Assert (Error_Msg_Sloc /= No_Location);
5275 Error_Msg_N ("(Ada 2005): hidden by private with clause #", N);
5279 Undefined (Nvis => True);
5283 -- First loop does hidden declarations
5286 while Present (Ent) loop
5287 if Is_Potentially_Use_Visible (Ent) then
5289 Error_Msg_N -- CODEFIX
5290 ("multiple use clauses cause hiding!", N);
5294 Error_Msg_Sloc := Sloc (Ent);
5295 Error_Msg_N -- CODEFIX
5296 ("hidden declaration#!", N);
5299 Ent := Homonym (Ent);
5302 -- If we found hidden declarations, then that's enough, don't
5303 -- bother looking for non-visible declarations as well.
5309 -- Second loop does non-directly visible declarations
5312 while Present (Ent) loop
5313 if not Is_Potentially_Use_Visible (Ent) then
5315 -- Do not bother the user with unknown entities
5317 if not Known_But_Invisible (Ent) then
5321 Error_Msg_Sloc := Sloc (Ent);
5323 -- Output message noting that there is a non-visible
5324 -- declaration, distinguishing the private part case.
5326 if Is_Hidden (Ent) then
5327 Error_Msg_N ("non-visible (private) declaration#!", N);
5329 -- If the entity is declared in a generic package, it
5330 -- cannot be visible, so there is no point in adding it
5331 -- to the list of candidates if another homograph from a
5332 -- non-generic package has been seen.
5334 elsif Ekind (Scope (Ent)) = E_Generic_Package
5340 Error_Msg_N -- CODEFIX
5341 ("non-visible declaration#!", N);
5343 if Ekind (Scope (Ent)) /= E_Generic_Package then
5347 if Is_Compilation_Unit (Ent)
5349 Nkind (Parent (Parent (N))) = N_Use_Package_Clause
5351 Error_Msg_Qual_Level := 99;
5352 Error_Msg_NE -- CODEFIX
5353 ("\\missing `WITH &;`", N, Ent);
5354 Error_Msg_Qual_Level := 0;
5357 if Ekind (Ent) = E_Discriminant
5358 and then Present (Corresponding_Discriminant (Ent))
5359 and then Scope (Corresponding_Discriminant (Ent)) =
5363 ("inherited discriminant not allowed here" &
5364 " (RM 3.8 (12), 3.8.1 (6))!", N);
5368 -- Set entity and its containing package as referenced. We
5369 -- can't be sure of this, but this seems a better choice
5370 -- to avoid unused entity messages.
5372 if Comes_From_Source (Ent) then
5373 Set_Referenced (Ent);
5374 Set_Referenced (Cunit_Entity (Get_Source_Unit (Ent)));
5379 Ent := Homonym (Ent);
5388 procedure Undefined (Nvis : Boolean) is
5389 Emsg : Error_Msg_Id;
5392 -- We should never find an undefined internal name. If we do, then
5393 -- see if we have previous errors. If so, ignore on the grounds that
5394 -- it is probably a cascaded message (e.g. a block label from a badly
5395 -- formed block). If no previous errors, then we have a real internal
5396 -- error of some kind so raise an exception.
5398 if Is_Internal_Name (Chars (N)) then
5399 if Total_Errors_Detected /= 0 then
5402 raise Program_Error;
5406 -- A very specialized error check, if the undefined variable is
5407 -- a case tag, and the case type is an enumeration type, check
5408 -- for a possible misspelling, and if so, modify the identifier
5410 -- Named aggregate should also be handled similarly ???
5413 and then Nkind (N) = N_Identifier
5414 and then Nkind (Parent (N)) = N_Case_Statement_Alternative
5417 Case_Stm : constant Node_Id := Parent (Parent (N));
5418 Case_Typ : constant Entity_Id := Etype (Expression (Case_Stm));
5423 if Is_Enumeration_Type (Case_Typ)
5424 and then not Is_Standard_Character_Type (Case_Typ)
5426 Lit := First_Literal (Case_Typ);
5427 Get_Name_String (Chars (Lit));
5429 if Chars (Lit) /= Chars (N)
5430 and then Is_Bad_Spelling_Of (Chars (N), Chars (Lit))
5432 Error_Msg_Node_2 := Lit;
5433 Error_Msg_N -- CODEFIX
5434 ("& is undefined, assume misspelling of &", N);
5435 Rewrite (N, New_Occurrence_Of (Lit, Sloc (N)));
5444 -- Normal processing
5446 Set_Entity (N, Any_Id);
5447 Set_Etype (N, Any_Type);
5451 -- We use the table Urefs to keep track of entities for which we
5452 -- have issued errors for undefined references. Multiple errors
5453 -- for a single name are normally suppressed, however we modify
5454 -- the error message to alert the programmer to this effect.
5456 for J in Urefs.First .. Urefs.Last loop
5457 if Chars (N) = Chars (Urefs.Table (J).Node) then
5458 if Urefs.Table (J).Err /= No_Error_Msg
5459 and then Sloc (N) /= Urefs.Table (J).Loc
5461 Error_Msg_Node_1 := Urefs.Table (J).Node;
5463 if Urefs.Table (J).Nvis then
5464 Change_Error_Text (Urefs.Table (J).Err,
5465 "& is not visible (more references follow)");
5467 Change_Error_Text (Urefs.Table (J).Err,
5468 "& is undefined (more references follow)");
5471 Urefs.Table (J).Err := No_Error_Msg;
5474 -- Although we will set Msg False, and thus suppress the
5475 -- message, we also set Error_Posted True, to avoid any
5476 -- cascaded messages resulting from the undefined reference.
5479 Set_Error_Posted (N);
5484 -- If entry not found, this is first undefined occurrence
5487 Error_Msg_N ("& is not visible!", N);
5491 Error_Msg_N ("& is undefined!", N);
5494 -- A very bizarre special check, if the undefined identifier
5495 -- is Put or Put_Line, then add a special error message (since
5496 -- this is a very common error for beginners to make).
5498 if Nam_In (Chars (N), Name_Put, Name_Put_Line) then
5499 Error_Msg_N -- CODEFIX
5500 ("\\possible missing `WITH Ada.Text_'I'O; " &
5501 "USE Ada.Text_'I'O`!", N);
5503 -- Another special check if N is the prefix of a selected
5504 -- component which is a known unit: add message complaining
5505 -- about missing with for this unit.
5507 elsif Nkind (Parent (N)) = N_Selected_Component
5508 and then N = Prefix (Parent (N))
5509 and then Is_Known_Unit (Parent (N))
5511 Error_Msg_Node_2 := Selector_Name (Parent (N));
5512 Error_Msg_N -- CODEFIX
5513 ("\\missing `WITH &.&;`", Prefix (Parent (N)));
5516 -- Now check for possible misspellings
5520 Ematch : Entity_Id := Empty;
5522 Last_Name_Id : constant Name_Id :=
5523 Name_Id (Nat (First_Name_Id) +
5524 Name_Entries_Count - 1);
5527 for Nam in First_Name_Id .. Last_Name_Id loop
5528 E := Get_Name_Entity_Id (Nam);
5531 and then (Is_Immediately_Visible (E)
5533 Is_Potentially_Use_Visible (E))
5535 if Is_Bad_Spelling_Of (Chars (N), Nam) then
5542 if Present (Ematch) then
5543 Error_Msg_NE -- CODEFIX
5544 ("\possible misspelling of&", N, Ematch);
5549 -- Make entry in undefined references table unless the full errors
5550 -- switch is set, in which case by refraining from generating the
5551 -- table entry we guarantee that we get an error message for every
5552 -- undefined reference. The entry is not added if we are ignoring
5555 if not All_Errors_Mode and then Ignore_Errors_Enable = 0 then
5569 Nested_Inst : Entity_Id := Empty;
5570 -- The entity of a nested instance which appears within Inst (if any)
5572 -- Start of processing for Find_Direct_Name
5575 -- If the entity pointer is already set, this is an internal node, or
5576 -- a node that is analyzed more than once, after a tree modification.
5577 -- In such a case there is no resolution to perform, just set the type.
5579 if Present (Entity (N)) then
5580 if Is_Type (Entity (N)) then
5581 Set_Etype (N, Entity (N));
5585 Entyp : constant Entity_Id := Etype (Entity (N));
5588 -- One special case here. If the Etype field is already set,
5589 -- and references the packed array type corresponding to the
5590 -- etype of the referenced entity, then leave it alone. This
5591 -- happens for trees generated from Exp_Pakd, where expressions
5592 -- can be deliberately "mis-typed" to the packed array type.
5594 if Is_Array_Type (Entyp)
5595 and then Is_Packed (Entyp)
5596 and then Present (Etype (N))
5597 and then Etype (N) = Packed_Array_Impl_Type (Entyp)
5601 -- If not that special case, then just reset the Etype
5604 Set_Etype (N, Etype (Entity (N)));
5609 -- Although the marking of use clauses happens at the end of
5610 -- Find_Direct_Name, a certain case where a generic actual satisfies
5611 -- a use clause must be checked here due to how the generic machinery
5612 -- handles the analysis of said actuals.
5615 and then Nkind (Parent (N)) = N_Generic_Association
5617 Mark_Use_Clauses (Entity (N));
5623 -- Preserve relevant elaboration-related attributes of the context which
5624 -- are no longer available or very expensive to recompute once analysis,
5625 -- resolution, and expansion are over.
5627 if Nkind (N) = N_Identifier then
5628 Mark_Elaboration_Attributes
5635 -- Here if Entity pointer was not set, we need full visibility analysis
5636 -- First we generate debugging output if the debug E flag is set.
5638 if Debug_Flag_E then
5639 Write_Str ("Looking for ");
5640 Write_Name (Chars (N));
5644 Homonyms := Current_Entity (N);
5645 Nvis_Entity := False;
5648 while Present (E) loop
5650 -- If entity is immediately visible or potentially use visible, then
5651 -- process the entity and we are done.
5653 if Is_Immediately_Visible (E) then
5654 goto Immediately_Visible_Entity;
5656 elsif Is_Potentially_Use_Visible (E) then
5657 goto Potentially_Use_Visible_Entity;
5659 -- Note if a known but invisible entity encountered
5661 elsif Known_But_Invisible (E) then
5662 Nvis_Entity := True;
5665 -- Move to next entity in chain and continue search
5670 -- If no entries on homonym chain that were potentially visible,
5671 -- and no entities reasonably considered as non-visible, then
5672 -- we have a plain undefined reference, with no additional
5673 -- explanation required.
5675 if not Nvis_Entity then
5676 Undefined (Nvis => False);
5678 -- Otherwise there is at least one entry on the homonym chain that
5679 -- is reasonably considered as being known and non-visible.
5687 -- Processing for a potentially use visible entry found. We must search
5688 -- the rest of the homonym chain for two reasons. First, if there is a
5689 -- directly visible entry, then none of the potentially use-visible
5690 -- entities are directly visible (RM 8.4(10)). Second, we need to check
5691 -- for the case of multiple potentially use-visible entries hiding one
5692 -- another and as a result being non-directly visible (RM 8.4(11)).
5694 <<Potentially_Use_Visible_Entity>> declare
5695 Only_One_Visible : Boolean := True;
5696 All_Overloadable : Boolean := Is_Overloadable (E);
5700 while Present (E2) loop
5701 if Is_Immediately_Visible (E2) then
5703 -- If the use-visible entity comes from the actual for a
5704 -- formal package, it hides a directly visible entity from
5705 -- outside the instance.
5707 if From_Actual_Package (E)
5708 and then Scope_Depth (E2) < Scope_Depth (Inst)
5713 goto Immediately_Visible_Entity;
5716 elsif Is_Potentially_Use_Visible (E2) then
5717 Only_One_Visible := False;
5718 All_Overloadable := All_Overloadable and Is_Overloadable (E2);
5720 -- Ada 2005 (AI-262): Protect against a form of Beaujolais effect
5721 -- that can occur in private_with clauses. Example:
5724 -- private with B; package A is
5725 -- package C is function B return Integer;
5727 -- V1 : Integer := B;
5728 -- private function B return Integer;
5729 -- V2 : Integer := B;
5732 -- V1 resolves to A.B, but V2 resolves to library unit B
5734 elsif Ekind (E2) = E_Function
5735 and then Scope (E2) = Standard_Standard
5736 and then Has_Private_With (E2)
5738 Only_One_Visible := False;
5739 All_Overloadable := False;
5740 Nvis_Is_Private_Subprg := True;
5747 -- On falling through this loop, we have checked that there are no
5748 -- immediately visible entities. Only_One_Visible is set if exactly
5749 -- one potentially use visible entity exists. All_Overloadable is
5750 -- set if all the potentially use visible entities are overloadable.
5751 -- The condition for legality is that either there is one potentially
5752 -- use visible entity, or if there is more than one, then all of them
5753 -- are overloadable.
5755 if Only_One_Visible or All_Overloadable then
5758 -- If there is more than one potentially use-visible entity and at
5759 -- least one of them non-overloadable, we have an error (RM 8.4(11)).
5760 -- Note that E points to the first such entity on the homonym list.
5763 -- If one of the entities is declared in an actual package, it
5764 -- was visible in the generic, and takes precedence over other
5765 -- entities that are potentially use-visible. The same applies
5766 -- if the entity is declared in a local instantiation of the
5767 -- current instance.
5771 -- Find the current instance
5773 Inst := Current_Scope;
5774 while Present (Inst) and then Inst /= Standard_Standard loop
5775 if Is_Generic_Instance (Inst) then
5779 Inst := Scope (Inst);
5782 -- Reexamine the candidate entities, giving priority to those
5783 -- that were visible within the generic.
5786 while Present (E2) loop
5787 Nested_Inst := Nearest_Enclosing_Instance (E2);
5789 -- The entity is declared within an actual package, or in a
5790 -- nested instance. The ">=" accounts for the case where the
5791 -- current instance and the nested instance are the same.
5793 if From_Actual_Package (E2)
5794 or else (Present (Nested_Inst)
5795 and then Scope_Depth (Nested_Inst) >=
5808 elsif Is_Predefined_Unit (Current_Sem_Unit) then
5809 -- A use clause in the body of a system file creates conflict
5810 -- with some entity in a user scope, while rtsfind is active.
5811 -- Keep only the entity coming from another predefined unit.
5814 while Present (E2) loop
5815 if In_Predefined_Unit (E2) then
5823 -- Entity must exist because predefined unit is correct
5825 raise Program_Error;
5834 -- Come here with E set to the first immediately visible entity on
5835 -- the homonym chain. This is the one we want unless there is another
5836 -- immediately visible entity further on in the chain for an inner
5837 -- scope (RM 8.3(8)).
5839 <<Immediately_Visible_Entity>> declare
5844 -- Find scope level of initial entity. When compiling through
5845 -- Rtsfind, the previous context is not completely invisible, and
5846 -- an outer entity may appear on the chain, whose scope is below
5847 -- the entry for Standard that delimits the current scope stack.
5848 -- Indicate that the level for this spurious entry is outside of
5849 -- the current scope stack.
5851 Level := Scope_Stack.Last;
5853 Scop := Scope_Stack.Table (Level).Entity;
5854 exit when Scop = Scope (E);
5856 exit when Scop = Standard_Standard;
5859 -- Now search remainder of homonym chain for more inner entry
5860 -- If the entity is Standard itself, it has no scope, and we
5861 -- compare it with the stack entry directly.
5864 while Present (E2) loop
5865 if Is_Immediately_Visible (E2) then
5867 -- If a generic package contains a local declaration that
5868 -- has the same name as the generic, there may be a visibility
5869 -- conflict in an instance, where the local declaration must
5870 -- also hide the name of the corresponding package renaming.
5871 -- We check explicitly for a package declared by a renaming,
5872 -- whose renamed entity is an instance that is on the scope
5873 -- stack, and that contains a homonym in the same scope. Once
5874 -- we have found it, we know that the package renaming is not
5875 -- immediately visible, and that the identifier denotes the
5876 -- other entity (and its homonyms if overloaded).
5878 if Scope (E) = Scope (E2)
5879 and then Ekind (E) = E_Package
5880 and then Present (Renamed_Object (E))
5881 and then Is_Generic_Instance (Renamed_Object (E))
5882 and then In_Open_Scopes (Renamed_Object (E))
5883 and then Comes_From_Source (N)
5885 Set_Is_Immediately_Visible (E, False);
5889 for J in Level + 1 .. Scope_Stack.Last loop
5890 if Scope_Stack.Table (J).Entity = Scope (E2)
5891 or else Scope_Stack.Table (J).Entity = E2
5904 -- At the end of that loop, E is the innermost immediately
5905 -- visible entity, so we are all set.
5908 -- Come here with entity found, and stored in E
5912 -- Check violation of No_Wide_Characters restriction
5914 Check_Wide_Character_Restriction (E, N);
5916 -- When distribution features are available (Get_PCS_Name /=
5917 -- Name_No_DSA), a remote access-to-subprogram type is converted
5918 -- into a record type holding whatever information is needed to
5919 -- perform a remote call on an RCI subprogram. In that case we
5920 -- rewrite any occurrence of the RAS type into the equivalent record
5921 -- type here. 'Access attribute references and RAS dereferences are
5922 -- then implemented using specific TSSs. However when distribution is
5923 -- not available (case of Get_PCS_Name = Name_No_DSA), we bypass the
5924 -- generation of these TSSs, and we must keep the RAS type in its
5925 -- original access-to-subprogram form (since all calls through a
5926 -- value of such type will be local anyway in the absence of a PCS).
5928 if Comes_From_Source (N)
5929 and then Is_Remote_Access_To_Subprogram_Type (E)
5930 and then Ekind (E) = E_Access_Subprogram_Type
5931 and then Expander_Active
5932 and then Get_PCS_Name /= Name_No_DSA
5934 Rewrite (N, New_Occurrence_Of (Equivalent_Type (E), Sloc (N)));
5938 -- Set the entity. Note that the reason we call Set_Entity for the
5939 -- overloadable case, as opposed to Set_Entity_With_Checks is
5940 -- that in the overloaded case, the initial call can set the wrong
5941 -- homonym. The call that sets the right homonym is in Sem_Res and
5942 -- that call does use Set_Entity_With_Checks, so we don't miss
5945 if Is_Overloadable (E) then
5948 Set_Entity_With_Checks (N, E);
5954 Set_Etype (N, Get_Full_View (Etype (E)));
5957 if Debug_Flag_E then
5958 Write_Str (" found ");
5959 Write_Entity_Info (E, " ");
5962 -- If the Ekind of the entity is Void, it means that all homonyms
5963 -- are hidden from all visibility (RM 8.3(5,14-20)). However, this
5964 -- test is skipped if the current scope is a record and the name is
5965 -- a pragma argument expression (case of Atomic and Volatile pragmas
5966 -- and possibly other similar pragmas added later, which are allowed
5967 -- to reference components in the current record).
5969 if Ekind (E) = E_Void
5971 (not Is_Record_Type (Current_Scope)
5972 or else Nkind (Parent (N)) /= N_Pragma_Argument_Association)
5974 Premature_Usage (N);
5976 -- If the entity is overloadable, collect all interpretations of the
5977 -- name for subsequent overload resolution. We optimize a bit here to
5978 -- do this only if we have an overloadable entity that is not on its
5979 -- own on the homonym chain.
5981 elsif Is_Overloadable (E)
5982 and then (Present (Homonym (E)) or else Current_Entity (N) /= E)
5984 Collect_Interps (N);
5986 -- If no homonyms were visible, the entity is unambiguous
5988 if not Is_Overloaded (N) then
5989 if Reference_OK and then not Is_Actual_Parameter then
5990 Generate_Reference (E, N);
5994 -- Case of non-overloadable entity, set the entity providing that
5995 -- we do not have the case of a discriminant reference within a
5996 -- default expression. Such references are replaced with the
5997 -- corresponding discriminal, which is the formal corresponding to
5998 -- to the discriminant in the initialization procedure.
6001 -- Entity is unambiguous, indicate that it is referenced here
6003 -- For a renaming of an object, always generate simple reference,
6004 -- we don't try to keep track of assignments in this case, except
6005 -- in SPARK mode where renamings are traversed for generating
6006 -- local effects of subprograms.
6009 and then Is_Object (E)
6010 and then Present (Renamed_Object (E))
6011 and then not GNATprove_Mode
6013 Generate_Reference (E, N);
6015 -- If the renamed entity is a private protected component,
6016 -- reference the original component as well. This needs to be
6017 -- done because the private renamings are installed before any
6018 -- analysis has occurred. Reference to a private component will
6019 -- resolve to the renaming and the original component will be
6020 -- left unreferenced, hence the following.
6022 if Is_Prival (E) then
6023 Generate_Reference (Prival_Link (E), N);
6026 -- One odd case is that we do not want to set the Referenced flag
6027 -- if the entity is a label, and the identifier is the label in
6028 -- the source, since this is not a reference from the point of
6029 -- view of the user.
6031 elsif Nkind (Parent (N)) = N_Label then
6033 R : constant Boolean := Referenced (E);
6036 -- Generate reference unless this is an actual parameter
6037 -- (see comment below)
6039 if Reference_OK and then Is_Actual_Parameter then
6040 Generate_Reference (E, N);
6041 Set_Referenced (E, R);
6045 -- Normal case, not a label: generate reference
6048 if Reference_OK and then not Is_Actual_Parameter then
6050 -- Package or generic package is always a simple reference
6052 if Is_Package_Or_Generic_Package (E) then
6053 Generate_Reference (E, N, 'r');
6055 -- Else see if we have a left hand side
6060 Generate_Reference (E, N, 'm');
6063 Generate_Reference (E, N, 'r');
6065 -- If we don't know now, generate reference later
6068 Deferred_References.Append ((E, N));
6074 Set_Entity_Or_Discriminal (N, E);
6076 -- The name may designate a generalized reference, in which case
6077 -- the dereference interpretation will be included. Context is
6078 -- one in which a name is legal.
6080 if Ada_Version >= Ada_2012
6082 (Nkind (Parent (N)) in N_Subexpr
6083 or else Nkind_In (Parent (N), N_Assignment_Statement,
6084 N_Object_Declaration,
6085 N_Parameter_Association))
6087 Check_Implicit_Dereference (N, Etype (E));
6092 -- Mark relevant use-type and use-package clauses as effective if the
6093 -- node in question is not overloaded and therefore does not require
6096 -- Note: Generic actual subprograms do not follow the normal resolution
6097 -- path, so ignore the fact that they are overloaded and mark them
6100 if Nkind (N) not in N_Subexpr or else not Is_Overloaded (N) then
6101 Mark_Use_Clauses (N);
6104 -- Come here with entity set
6107 Check_Restriction_No_Use_Of_Entity (N);
6109 -- Annotate the tree by creating a variable reference marker in case the
6110 -- original variable reference is folded or optimized away. The variable
6111 -- reference marker is automatically saved for later examination by the
6112 -- ABE Processing phase. Variable references which act as actuals in a
6113 -- call require special processing and are left to Resolve_Actuals. The
6114 -- reference is a write when it appears on the left hand side of an
6118 and then Needs_Variable_Reference_Marker
6123 Is_Assignment_LHS : constant Boolean := Is_LHS (N) = Yes;
6126 Build_Variable_Reference_Marker
6128 Read => not Is_Assignment_LHS,
6129 Write => Is_Assignment_LHS);
6132 end Find_Direct_Name;
6134 ------------------------
6135 -- Find_Expanded_Name --
6136 ------------------------
6138 -- This routine searches the homonym chain of the entity until it finds
6139 -- an entity declared in the scope denoted by the prefix. If the entity
6140 -- is private, it may nevertheless be immediately visible, if we are in
6141 -- the scope of its declaration.
6143 procedure Find_Expanded_Name (N : Node_Id) is
6144 function In_Abstract_View_Pragma (Nod : Node_Id) return Boolean;
6145 -- Determine whether expanded name Nod appears within a pragma which is
6146 -- a suitable context for an abstract view of a state or variable. The
6147 -- following pragmas fall in this category:
6154 -- In addition, pragma Abstract_State is also considered suitable even
6155 -- though it is an illegal context for an abstract view as this allows
6156 -- for proper resolution of abstract views of variables. This illegal
6157 -- context is later flagged in the analysis of indicator Part_Of.
6159 -----------------------------
6160 -- In_Abstract_View_Pragma --
6161 -----------------------------
6163 function In_Abstract_View_Pragma (Nod : Node_Id) return Boolean is
6167 -- Climb the parent chain looking for a pragma
6170 while Present (Par) loop
6171 if Nkind (Par) = N_Pragma then
6172 if Nam_In (Pragma_Name_Unmapped (Par),
6173 Name_Abstract_State,
6177 Name_Refined_Depends,
6178 Name_Refined_Global)
6182 -- Otherwise the pragma is not a legal context for an abstract
6189 -- Prevent the search from going too far
6191 elsif Is_Body_Or_Package_Declaration (Par) then
6195 Par := Parent (Par);
6199 end In_Abstract_View_Pragma;
6203 Selector : constant Node_Id := Selector_Name (N);
6205 Candidate : Entity_Id := Empty;
6209 -- Start of processing for Find_Expanded_Name
6212 P_Name := Entity (Prefix (N));
6214 -- If the prefix is a renamed package, look for the entity in the
6215 -- original package.
6217 if Ekind (P_Name) = E_Package
6218 and then Present (Renamed_Object (P_Name))
6220 P_Name := Renamed_Object (P_Name);
6222 -- Rewrite node with entity field pointing to renamed object
6224 Rewrite (Prefix (N), New_Copy (Prefix (N)));
6225 Set_Entity (Prefix (N), P_Name);
6227 -- If the prefix is an object of a concurrent type, look for
6228 -- the entity in the associated task or protected type.
6230 elsif Is_Concurrent_Type (Etype (P_Name)) then
6231 P_Name := Etype (P_Name);
6234 Id := Current_Entity (Selector);
6237 Is_New_Candidate : Boolean;
6240 while Present (Id) loop
6241 if Scope (Id) = P_Name then
6243 Is_New_Candidate := True;
6245 -- Handle abstract views of states and variables. These are
6246 -- acceptable candidates only when the reference to the view
6247 -- appears in certain pragmas.
6249 if Ekind (Id) = E_Abstract_State
6250 and then From_Limited_With (Id)
6251 and then Present (Non_Limited_View (Id))
6253 if In_Abstract_View_Pragma (N) then
6254 Candidate := Non_Limited_View (Id);
6255 Is_New_Candidate := True;
6257 -- Hide the candidate because it is not used in a proper
6262 Is_New_Candidate := False;
6266 -- Ada 2005 (AI-217): Handle shadow entities associated with
6267 -- types declared in limited-withed nested packages. We don't need
6268 -- to handle E_Incomplete_Subtype entities because the entities
6269 -- in the limited view are always E_Incomplete_Type and
6270 -- E_Class_Wide_Type entities (see Build_Limited_Views).
6272 -- Regarding the expression used to evaluate the scope, it
6273 -- is important to note that the limited view also has shadow
6274 -- entities associated nested packages. For this reason the
6275 -- correct scope of the entity is the scope of the real entity.
6276 -- The non-limited view may itself be incomplete, in which case
6277 -- get the full view if available.
6279 elsif Ekind_In (Id, E_Incomplete_Type, E_Class_Wide_Type)
6280 and then From_Limited_With (Id)
6281 and then Present (Non_Limited_View (Id))
6282 and then Scope (Non_Limited_View (Id)) = P_Name
6284 Candidate := Get_Full_View (Non_Limited_View (Id));
6285 Is_New_Candidate := True;
6287 -- An unusual case arises with a fully qualified name for an
6288 -- entity local to a generic child unit package, within an
6289 -- instantiation of that package. The name of the unit now
6290 -- denotes the renaming created within the instance. This is
6291 -- only relevant in an instance body, see below.
6293 elsif Is_Generic_Instance (Scope (Id))
6294 and then In_Open_Scopes (Scope (Id))
6295 and then In_Instance_Body
6296 and then Ekind (Scope (Id)) = E_Package
6297 and then Ekind (Id) = E_Package
6298 and then Renamed_Entity (Id) = Scope (Id)
6299 and then Is_Immediately_Visible (P_Name)
6301 Is_New_Candidate := True;
6304 Is_New_Candidate := False;
6307 if Is_New_Candidate then
6309 -- If entity is a child unit, either it is a visible child of
6310 -- the prefix, or we are in the body of a generic prefix, as
6311 -- will happen when a child unit is instantiated in the body
6312 -- of a generic parent. This is because the instance body does
6313 -- not restore the full compilation context, given that all
6314 -- non-local references have been captured.
6316 if Is_Child_Unit (Id) or else P_Name = Standard_Standard then
6317 exit when Is_Visible_Lib_Unit (Id)
6318 or else (Is_Child_Unit (Id)
6319 and then In_Open_Scopes (Scope (Id))
6320 and then In_Instance_Body);
6322 exit when not Is_Hidden (Id);
6325 exit when Is_Immediately_Visible (Id);
6333 and then Ekind_In (P_Name, E_Procedure, E_Function)
6334 and then Is_Generic_Instance (P_Name)
6336 -- Expanded name denotes entity in (instance of) generic subprogram.
6337 -- The entity may be in the subprogram instance, or may denote one of
6338 -- the formals, which is declared in the enclosing wrapper package.
6340 P_Name := Scope (P_Name);
6342 Id := Current_Entity (Selector);
6343 while Present (Id) loop
6344 exit when Scope (Id) = P_Name;
6349 if No (Id) or else Chars (Id) /= Chars (Selector) then
6350 Set_Etype (N, Any_Type);
6352 -- If we are looking for an entity defined in System, try to find it
6353 -- in the child package that may have been provided as an extension
6354 -- to System. The Extend_System pragma will have supplied the name of
6355 -- the extension, which may have to be loaded.
6357 if Chars (P_Name) = Name_System
6358 and then Scope (P_Name) = Standard_Standard
6359 and then Present (System_Extend_Unit)
6360 and then Present_System_Aux (N)
6362 Set_Entity (Prefix (N), System_Aux_Id);
6363 Find_Expanded_Name (N);
6366 -- There is an implicit instance of the predefined operator in
6367 -- the given scope. The operator entity is defined in Standard.
6368 -- Has_Implicit_Operator makes the node into an Expanded_Name.
6370 elsif Nkind (Selector) = N_Operator_Symbol
6371 and then Has_Implicit_Operator (N)
6375 -- If there is no literal defined in the scope denoted by the
6376 -- prefix, the literal may belong to (a type derived from)
6377 -- Standard_Character, for which we have no explicit literals.
6379 elsif Nkind (Selector) = N_Character_Literal
6380 and then Has_Implicit_Character_Literal (N)
6385 -- If the prefix is a single concurrent object, use its name in
6386 -- the error message, rather than that of the anonymous type.
6388 if Is_Concurrent_Type (P_Name)
6389 and then Is_Internal_Name (Chars (P_Name))
6391 Error_Msg_Node_2 := Entity (Prefix (N));
6393 Error_Msg_Node_2 := P_Name;
6396 if P_Name = System_Aux_Id then
6397 P_Name := Scope (P_Name);
6398 Set_Entity (Prefix (N), P_Name);
6401 if Present (Candidate) then
6403 -- If we know that the unit is a child unit we can give a more
6404 -- accurate error message.
6406 if Is_Child_Unit (Candidate) then
6408 -- If the candidate is a private child unit and we are in
6409 -- the visible part of a public unit, specialize the error
6410 -- message. There might be a private with_clause for it,
6411 -- but it is not currently active.
6413 if Is_Private_Descendant (Candidate)
6414 and then Ekind (Current_Scope) = E_Package
6415 and then not In_Private_Part (Current_Scope)
6416 and then not Is_Private_Descendant (Current_Scope)
6419 ("private child unit& is not visible here", Selector);
6421 -- Normal case where we have a missing with for a child unit
6424 Error_Msg_Qual_Level := 99;
6425 Error_Msg_NE -- CODEFIX
6426 ("missing `WITH &;`", Selector, Candidate);
6427 Error_Msg_Qual_Level := 0;
6430 -- Here we don't know that this is a child unit
6433 Error_Msg_NE ("& is not a visible entity of&", N, Selector);
6437 -- Within the instantiation of a child unit, the prefix may
6438 -- denote the parent instance, but the selector has the name
6439 -- of the original child. That is to say, when A.B appears
6440 -- within an instantiation of generic child unit B, the scope
6441 -- stack includes an instance of A (P_Name) and an instance
6442 -- of B under some other name. We scan the scope to find this
6443 -- child instance, which is the desired entity.
6444 -- Note that the parent may itself be a child instance, if
6445 -- the reference is of the form A.B.C, in which case A.B has
6446 -- already been rewritten with the proper entity.
6448 if In_Open_Scopes (P_Name)
6449 and then Is_Generic_Instance (P_Name)
6452 Gen_Par : constant Entity_Id :=
6453 Generic_Parent (Specification
6454 (Unit_Declaration_Node (P_Name)));
6455 S : Entity_Id := Current_Scope;
6459 for J in reverse 0 .. Scope_Stack.Last loop
6460 S := Scope_Stack.Table (J).Entity;
6462 exit when S = Standard_Standard;
6464 if Ekind_In (S, E_Function,
6469 Generic_Parent (Specification
6470 (Unit_Declaration_Node (S)));
6472 -- Check that P is a generic child of the generic
6473 -- parent of the prefix.
6476 and then Chars (P) = Chars (Selector)
6477 and then Scope (P) = Gen_Par
6488 -- If this is a selection from Ada, System or Interfaces, then
6489 -- we assume a missing with for the corresponding package.
6491 if Is_Known_Unit (N)
6492 and then not (Present (Entity (Prefix (N)))
6493 and then Scope (Entity (Prefix (N))) /=
6496 if not Error_Posted (N) then
6497 Error_Msg_Node_2 := Selector;
6498 Error_Msg_N -- CODEFIX
6499 ("missing `WITH &.&;`", Prefix (N));
6502 -- If this is a selection from a dummy package, then suppress
6503 -- the error message, of course the entity is missing if the
6504 -- package is missing.
6506 elsif Sloc (Error_Msg_Node_2) = No_Location then
6509 -- Here we have the case of an undefined component
6512 -- The prefix may hide a homonym in the context that
6513 -- declares the desired entity. This error can use a
6514 -- specialized message.
6516 if In_Open_Scopes (P_Name) then
6518 H : constant Entity_Id := Homonym (P_Name);
6522 and then Is_Compilation_Unit (H)
6524 (Is_Immediately_Visible (H)
6525 or else Is_Visible_Lib_Unit (H))
6527 Id := First_Entity (H);
6528 while Present (Id) loop
6529 if Chars (Id) = Chars (Selector) then
6530 Error_Msg_Qual_Level := 99;
6531 Error_Msg_Name_1 := Chars (Selector);
6533 ("% not declared in&", N, P_Name);
6535 ("\use fully qualified name starting with "
6536 & "Standard to make& visible", N, H);
6537 Error_Msg_Qual_Level := 0;
6545 -- If not found, standard error message
6547 Error_Msg_NE ("& not declared in&", N, Selector);
6553 -- Might be worth specializing the case when the prefix
6554 -- is a limited view.
6555 -- ... not declared in limited view of...
6557 Error_Msg_NE ("& not declared in&", N, Selector);
6560 -- Check for misspelling of some entity in prefix
6562 Id := First_Entity (P_Name);
6563 while Present (Id) loop
6564 if Is_Bad_Spelling_Of (Chars (Id), Chars (Selector))
6565 and then not Is_Internal_Name (Chars (Id))
6567 Error_Msg_NE -- CODEFIX
6568 ("possible misspelling of&", Selector, Id);
6575 -- Specialize the message if this may be an instantiation
6576 -- of a child unit that was not mentioned in the context.
6578 if Nkind (Parent (N)) = N_Package_Instantiation
6579 and then Is_Generic_Instance (Entity (Prefix (N)))
6580 and then Is_Compilation_Unit
6581 (Generic_Parent (Parent (Entity (Prefix (N)))))
6583 Error_Msg_Node_2 := Selector;
6584 Error_Msg_N -- CODEFIX
6585 ("\missing `WITH &.&;`", Prefix (N));
6595 if Comes_From_Source (N)
6596 and then Is_Remote_Access_To_Subprogram_Type (Id)
6597 and then Ekind (Id) = E_Access_Subprogram_Type
6598 and then Present (Equivalent_Type (Id))
6600 -- If we are not actually generating distribution code (i.e. the
6601 -- current PCS is the dummy non-distributed version), then the
6602 -- Equivalent_Type will be missing, and Id should be treated as
6603 -- a regular access-to-subprogram type.
6605 Id := Equivalent_Type (Id);
6606 Set_Chars (Selector, Chars (Id));
6609 -- Ada 2005 (AI-50217): Check usage of entities in limited withed units
6611 if Ekind (P_Name) = E_Package and then From_Limited_With (P_Name) then
6612 if From_Limited_With (Id)
6613 or else Is_Type (Id)
6614 or else Ekind (Id) = E_Package
6619 ("limited withed package can only be used to access incomplete "
6624 if Is_Task_Type (P_Name)
6625 and then ((Ekind (Id) = E_Entry
6626 and then Nkind (Parent (N)) /= N_Attribute_Reference)
6628 (Ekind (Id) = E_Entry_Family
6630 Nkind (Parent (Parent (N))) /= N_Attribute_Reference))
6632 -- If both the task type and the entry are in scope, this may still
6633 -- be the expanded name of an entry formal.
6635 if In_Open_Scopes (Id)
6636 and then Nkind (Parent (N)) = N_Selected_Component
6641 -- It is an entry call after all, either to the current task
6642 -- (which will deadlock) or to an enclosing task.
6644 Analyze_Selected_Component (N);
6649 Change_Selected_Component_To_Expanded_Name (N);
6651 -- Preserve relevant elaboration-related attributes of the context which
6652 -- are no longer available or very expensive to recompute once analysis,
6653 -- resolution, and expansion are over.
6655 Mark_Elaboration_Attributes
6661 -- Set appropriate type
6663 if Is_Type (Id) then
6666 Set_Etype (N, Get_Full_View (Etype (Id)));
6669 -- Do style check and generate reference, but skip both steps if this
6670 -- entity has homonyms, since we may not have the right homonym set yet.
6671 -- The proper homonym will be set during the resolve phase.
6673 if Has_Homonym (Id) then
6677 Set_Entity_Or_Discriminal (N, Id);
6681 Generate_Reference (Id, N, 'm');
6684 Generate_Reference (Id, N, 'r');
6687 Deferred_References.Append ((Id, N));
6691 -- Check for violation of No_Wide_Characters
6693 Check_Wide_Character_Restriction (Id, N);
6695 -- If the Ekind of the entity is Void, it means that all homonyms are
6696 -- hidden from all visibility (RM 8.3(5,14-20)).
6698 if Ekind (Id) = E_Void then
6699 Premature_Usage (N);
6701 elsif Is_Overloadable (Id) and then Present (Homonym (Id)) then
6703 H : Entity_Id := Homonym (Id);
6706 while Present (H) loop
6707 if Scope (H) = Scope (Id)
6708 and then (not Is_Hidden (H)
6709 or else Is_Immediately_Visible (H))
6711 Collect_Interps (N);
6718 -- If an extension of System is present, collect possible explicit
6719 -- overloadings declared in the extension.
6721 if Chars (P_Name) = Name_System
6722 and then Scope (P_Name) = Standard_Standard
6723 and then Present (System_Extend_Unit)
6724 and then Present_System_Aux (N)
6726 H := Current_Entity (Id);
6728 while Present (H) loop
6729 if Scope (H) = System_Aux_Id then
6730 Add_One_Interp (N, H, Etype (H));
6739 if Nkind (Selector_Name (N)) = N_Operator_Symbol
6740 and then Scope (Id) /= Standard_Standard
6742 -- In addition to user-defined operators in the given scope, there
6743 -- may be an implicit instance of the predefined operator. The
6744 -- operator (defined in Standard) is found in Has_Implicit_Operator,
6745 -- and added to the interpretations. Procedure Add_One_Interp will
6746 -- determine which hides which.
6748 if Has_Implicit_Operator (N) then
6753 -- If there is a single interpretation for N we can generate a
6754 -- reference to the unique entity found.
6756 if Is_Overloadable (Id) and then not Is_Overloaded (N) then
6757 Generate_Reference (Id, N);
6760 -- Mark relevant use-type and use-package clauses as effective if the
6761 -- node in question is not overloaded and therefore does not require
6764 if Nkind (N) not in N_Subexpr or else not Is_Overloaded (N) then
6765 Mark_Use_Clauses (N);
6768 Check_Restriction_No_Use_Of_Entity (N);
6770 -- Annotate the tree by creating a variable reference marker in case the
6771 -- original variable reference is folded or optimized away. The variable
6772 -- reference marker is automatically saved for later examination by the
6773 -- ABE Processing phase. Variable references which act as actuals in a
6774 -- call require special processing and are left to Resolve_Actuals. The
6775 -- reference is a write when it appears on the left hand side of an
6778 if Needs_Variable_Reference_Marker
6783 Is_Assignment_LHS : constant Boolean := Is_LHS (N) = Yes;
6786 Build_Variable_Reference_Marker
6788 Read => not Is_Assignment_LHS,
6789 Write => Is_Assignment_LHS);
6792 end Find_Expanded_Name;
6794 --------------------
6795 -- Find_Most_Prev --
6796 --------------------
6798 function Find_Most_Prev (Use_Clause : Node_Id) return Node_Id is
6802 -- Loop through the Prev_Use_Clause chain
6805 while Present (Prev_Use_Clause (Curr)) loop
6806 Curr := Prev_Use_Clause (Curr);
6812 -------------------------
6813 -- Find_Renamed_Entity --
6814 -------------------------
6816 function Find_Renamed_Entity
6820 Is_Actual : Boolean := False) return Entity_Id
6823 I1 : Interp_Index := 0; -- Suppress junk warnings
6829 function Find_Nearer_Entity
6832 Old2_S : Entity_Id) return Entity_Id;
6833 -- Determine whether one of Old_S1 and Old_S2 is nearer to New_S than
6834 -- the other, and return it if so. Return Empty otherwise. We use this
6835 -- in conjunction with Inherit_Renamed_Profile to simplify later type
6836 -- disambiguation for actual subprograms in instances.
6838 function Is_Visible_Operation (Op : Entity_Id) return Boolean;
6839 -- If the renamed entity is an implicit operator, check whether it is
6840 -- visible because its operand type is properly visible. This check
6841 -- applies to explicit renamed entities that appear in the source in a
6842 -- renaming declaration or a formal subprogram instance, but not to
6843 -- default generic actuals with a name.
6845 function Report_Overload return Entity_Id;
6846 -- List possible interpretations, and specialize message in the
6847 -- case of a generic actual.
6849 function Within (Inner, Outer : Entity_Id) return Boolean;
6850 -- Determine whether a candidate subprogram is defined within the
6851 -- enclosing instance. If yes, it has precedence over outer candidates.
6853 --------------------------
6854 -- Find_Nearer_Entity --
6855 --------------------------
6857 function Find_Nearer_Entity
6860 Old2_S : Entity_Id) return Entity_Id
6868 New_F := First_Formal (New_S);
6869 Old1_F := First_Formal (Old1_S);
6870 Old2_F := First_Formal (Old2_S);
6872 -- The criterion is whether the type of the formals of one of Old1_S
6873 -- and Old2_S is an ancestor subtype of the type of the corresponding
6874 -- formals of New_S while the other is not (we already know that they
6875 -- are all subtypes of the same base type).
6877 -- This makes it possible to find the more correct renamed entity in
6878 -- the case of a generic instantiation nested in an enclosing one for
6879 -- which different formal types get the same actual type, which will
6880 -- in turn make it possible for Inherit_Renamed_Profile to preserve
6881 -- types on formal parameters and ultimately simplify disambiguation.
6883 -- Consider the follow package G:
6886 -- type Item_T is private;
6887 -- with function Compare (L, R: Item_T) return Boolean is <>;
6889 -- type Bound_T is private;
6890 -- with function Compare (L, R : Bound_T) return Boolean is <>;
6895 -- package body G is
6896 -- package My_Inner is Inner_G (Bound_T);
6900 -- with the following package Inner_G:
6903 -- type T is private;
6904 -- with function Compare (L, R: T) return Boolean is <>;
6905 -- package Inner_G is
6906 -- function "<" (L, R: T) return Boolean is (Compare (L, R));
6909 -- If G is instantiated on the same actual type with a single Compare
6913 -- function Compare (L, R : T) return Boolean;
6914 -- package My_G is new (T, T);
6916 -- then the renaming generated for Compare in the inner instantiation
6917 -- is ambiguous: it can rename either of the renamings generated for
6918 -- the outer instantiation. Now if the first one is picked up, then
6919 -- the subtypes of the formal parameters of the renaming will not be
6920 -- preserved in Inherit_Renamed_Profile because they are subtypes of
6921 -- the Bound_T formal type and not of the Item_T formal type, so we
6922 -- need to arrange for the second one to be picked up instead.
6924 while Present (New_F) loop
6925 if Etype (Old1_F) /= Etype (Old2_F) then
6926 Anc_T := Ancestor_Subtype (Etype (New_F));
6928 if Etype (Old1_F) = Anc_T then
6930 elsif Etype (Old2_F) = Anc_T then
6935 Next_Formal (New_F);
6936 Next_Formal (Old1_F);
6937 Next_Formal (Old2_F);
6940 pragma Assert (No (Old1_F));
6941 pragma Assert (No (Old2_F));
6944 end Find_Nearer_Entity;
6946 --------------------------
6947 -- Is_Visible_Operation --
6948 --------------------------
6950 function Is_Visible_Operation (Op : Entity_Id) return Boolean is
6956 if Ekind (Op) /= E_Operator
6957 or else Scope (Op) /= Standard_Standard
6958 or else (In_Instance
6959 and then (not Is_Actual
6960 or else Present (Enclosing_Instance)))
6965 -- For a fixed point type operator, check the resulting type,
6966 -- because it may be a mixed mode integer * fixed operation.
6968 if Present (Next_Formal (First_Formal (New_S)))
6969 and then Is_Fixed_Point_Type (Etype (New_S))
6971 Typ := Etype (New_S);
6973 Typ := Etype (First_Formal (New_S));
6976 Btyp := Base_Type (Typ);
6978 if Nkind (Nam) /= N_Expanded_Name then
6979 return (In_Open_Scopes (Scope (Btyp))
6980 or else Is_Potentially_Use_Visible (Btyp)
6981 or else In_Use (Btyp)
6982 or else In_Use (Scope (Btyp)));
6985 Scop := Entity (Prefix (Nam));
6987 if Ekind (Scop) = E_Package
6988 and then Present (Renamed_Object (Scop))
6990 Scop := Renamed_Object (Scop);
6993 -- Operator is visible if prefix of expanded name denotes
6994 -- scope of type, or else type is defined in System_Aux
6995 -- and the prefix denotes System.
6997 return Scope (Btyp) = Scop
6998 or else (Scope (Btyp) = System_Aux_Id
6999 and then Scope (Scope (Btyp)) = Scop);
7002 end Is_Visible_Operation;
7008 function Within (Inner, Outer : Entity_Id) return Boolean is
7012 Sc := Scope (Inner);
7013 while Sc /= Standard_Standard loop
7024 ---------------------
7025 -- Report_Overload --
7026 ---------------------
7028 function Report_Overload return Entity_Id is
7031 Error_Msg_NE -- CODEFIX
7032 ("ambiguous actual subprogram&, " &
7033 "possible interpretations:", N, Nam);
7035 Error_Msg_N -- CODEFIX
7036 ("ambiguous subprogram, " &
7037 "possible interpretations:", N);
7040 List_Interps (Nam, N);
7042 end Report_Overload;
7044 -- Start of processing for Find_Renamed_Entity
7048 Candidate_Renaming := Empty;
7050 if Is_Overloaded (Nam) then
7051 Get_First_Interp (Nam, Ind, It);
7052 while Present (It.Nam) loop
7053 if Entity_Matches_Spec (It.Nam, New_S)
7054 and then Is_Visible_Operation (It.Nam)
7056 if Old_S /= Any_Id then
7058 -- Note: The call to Disambiguate only happens if a
7059 -- previous interpretation was found, in which case I1
7060 -- has received a value.
7062 It1 := Disambiguate (Nam, I1, Ind, Etype (Old_S));
7064 if It1 = No_Interp then
7065 Inst := Enclosing_Instance;
7067 if Present (Inst) then
7068 if Within (It.Nam, Inst) then
7069 if Within (Old_S, Inst) then
7071 It_D : constant Uint := Scope_Depth (It.Nam);
7072 Old_D : constant Uint := Scope_Depth (Old_S);
7075 -- Choose the innermost subprogram, which
7076 -- would hide the outer one in the generic.
7078 if Old_D > It_D then
7080 elsif It_D > Old_D then
7084 -- Otherwise, if we can determine that one
7085 -- of the entities is nearer to the renaming
7086 -- than the other, choose it. If not, then
7087 -- return the newer one as done historically.
7090 Find_Nearer_Entity (New_S, Old_S, It.Nam);
7091 if Present (N_Ent) then
7099 elsif Within (Old_S, Inst) then
7103 return Report_Overload;
7106 -- If not within an instance, ambiguity is real
7109 return Report_Overload;
7123 Present (First_Formal (It.Nam))
7124 and then Present (First_Formal (New_S))
7125 and then (Base_Type (Etype (First_Formal (It.Nam))) =
7126 Base_Type (Etype (First_Formal (New_S))))
7128 Candidate_Renaming := It.Nam;
7131 Get_Next_Interp (Ind, It);
7134 Set_Entity (Nam, Old_S);
7136 if Old_S /= Any_Id then
7137 Set_Is_Overloaded (Nam, False);
7140 -- Non-overloaded case
7144 and then Present (Enclosing_Instance)
7145 and then Entity_Matches_Spec (Entity (Nam), New_S)
7147 Old_S := Entity (Nam);
7149 elsif Entity_Matches_Spec (Entity (Nam), New_S) then
7150 Candidate_Renaming := New_S;
7152 if Is_Visible_Operation (Entity (Nam)) then
7153 Old_S := Entity (Nam);
7156 elsif Present (First_Formal (Entity (Nam)))
7157 and then Present (First_Formal (New_S))
7158 and then (Base_Type (Etype (First_Formal (Entity (Nam)))) =
7159 Base_Type (Etype (First_Formal (New_S))))
7161 Candidate_Renaming := Entity (Nam);
7166 end Find_Renamed_Entity;
7168 -----------------------------
7169 -- Find_Selected_Component --
7170 -----------------------------
7172 procedure Find_Selected_Component (N : Node_Id) is
7173 P : constant Node_Id := Prefix (N);
7176 -- Entity denoted by prefix
7183 function Available_Subtype return Boolean;
7184 -- A small optimization: if the prefix is constrained and the component
7185 -- is an array type we may already have a usable subtype for it, so we
7186 -- can use it rather than generating a new one, because the bounds
7187 -- will be the values of the discriminants and not discriminant refs.
7188 -- This simplifies value tracing in GNATprove. For consistency, both
7189 -- the entity name and the subtype come from the constrained component.
7191 -- This is only used in GNATprove mode: when generating code it may be
7192 -- necessary to create an itype in the scope of use of the selected
7193 -- component, e.g. in the context of a expanded record equality.
7195 function Is_Reference_In_Subunit return Boolean;
7196 -- In a subunit, the scope depth is not a proper measure of hiding,
7197 -- because the context of the proper body may itself hide entities in
7198 -- parent units. This rare case requires inspecting the tree directly
7199 -- because the proper body is inserted in the main unit and its context
7200 -- is simply added to that of the parent.
7202 -----------------------
7203 -- Available_Subtype --
7204 -----------------------
7206 function Available_Subtype return Boolean is
7210 if GNATprove_Mode then
7211 Comp := First_Entity (Etype (P));
7212 while Present (Comp) loop
7213 if Chars (Comp) = Chars (Selector_Name (N)) then
7214 Set_Etype (N, Etype (Comp));
7215 Set_Entity (Selector_Name (N), Comp);
7216 Set_Etype (Selector_Name (N), Etype (Comp));
7220 Next_Component (Comp);
7225 end Available_Subtype;
7227 -----------------------------
7228 -- Is_Reference_In_Subunit --
7229 -----------------------------
7231 function Is_Reference_In_Subunit return Boolean is
7233 Comp_Unit : Node_Id;
7237 while Present (Comp_Unit)
7238 and then Nkind (Comp_Unit) /= N_Compilation_Unit
7240 Comp_Unit := Parent (Comp_Unit);
7243 if No (Comp_Unit) or else Nkind (Unit (Comp_Unit)) /= N_Subunit then
7247 -- Now check whether the package is in the context of the subunit
7249 Clause := First (Context_Items (Comp_Unit));
7250 while Present (Clause) loop
7251 if Nkind (Clause) = N_With_Clause
7252 and then Entity (Name (Clause)) = P_Name
7261 end Is_Reference_In_Subunit;
7263 -- Start of processing for Find_Selected_Component
7268 if Nkind (P) = N_Error then
7272 -- If the selector already has an entity, the node has been constructed
7273 -- in the course of expansion, and is known to be valid. Do not verify
7274 -- that it is defined for the type (it may be a private component used
7275 -- in the expansion of record equality).
7277 if Present (Entity (Selector_Name (N))) then
7278 if No (Etype (N)) or else Etype (N) = Any_Type then
7280 Sel_Name : constant Node_Id := Selector_Name (N);
7281 Selector : constant Entity_Id := Entity (Sel_Name);
7285 Set_Etype (Sel_Name, Etype (Selector));
7287 if not Is_Entity_Name (P) then
7291 -- Build an actual subtype except for the first parameter
7292 -- of an init proc, where this actual subtype is by
7293 -- definition incorrect, since the object is uninitialized
7294 -- (and does not even have defined discriminants etc.)
7296 if Is_Entity_Name (P)
7297 and then Ekind (Entity (P)) = E_Function
7299 Nam := New_Copy (P);
7301 if Is_Overloaded (P) then
7302 Save_Interps (P, Nam);
7305 Rewrite (P, Make_Function_Call (Sloc (P), Name => Nam));
7307 Analyze_Selected_Component (N);
7310 elsif Ekind (Selector) = E_Component
7311 and then (not Is_Entity_Name (P)
7312 or else Chars (Entity (P)) /= Name_uInit)
7314 -- Check if we already have an available subtype we can use
7316 if Ekind (Etype (P)) = E_Record_Subtype
7317 and then Nkind (Parent (Etype (P))) = N_Subtype_Declaration
7318 and then Is_Array_Type (Etype (Selector))
7319 and then not Is_Packed (Etype (Selector))
7320 and then Available_Subtype
7324 -- Do not build the subtype when referencing components of
7325 -- dispatch table wrappers. Required to avoid generating
7326 -- elaboration code with HI runtimes.
7328 elsif RTU_Loaded (Ada_Tags)
7330 ((RTE_Available (RE_Dispatch_Table_Wrapper)
7331 and then Scope (Selector) =
7332 RTE (RE_Dispatch_Table_Wrapper))
7334 (RTE_Available (RE_No_Dispatch_Table_Wrapper)
7335 and then Scope (Selector) =
7336 RTE (RE_No_Dispatch_Table_Wrapper)))
7341 Build_Actual_Subtype_Of_Component
7342 (Etype (Selector), N);
7349 if No (C_Etype) then
7350 C_Etype := Etype (Selector);
7352 Insert_Action (N, C_Etype);
7353 C_Etype := Defining_Identifier (C_Etype);
7356 Set_Etype (N, C_Etype);
7359 -- If the selected component appears within a default expression
7360 -- and it has an actual subtype, the preanalysis has not yet
7361 -- completed its analysis, because Insert_Actions is disabled in
7362 -- that context. Within the init proc of the enclosing type we
7363 -- must complete this analysis, if an actual subtype was created.
7365 elsif Inside_Init_Proc then
7367 Typ : constant Entity_Id := Etype (N);
7368 Decl : constant Node_Id := Declaration_Node (Typ);
7370 if Nkind (Decl) = N_Subtype_Declaration
7371 and then not Analyzed (Decl)
7372 and then Is_List_Member (Decl)
7373 and then No (Parent (Decl))
7376 Insert_Action (N, Decl);
7383 elsif Is_Entity_Name (P) then
7384 P_Name := Entity (P);
7386 -- The prefix may denote an enclosing type which is the completion
7387 -- of an incomplete type declaration.
7389 if Is_Type (P_Name) then
7390 Set_Entity (P, Get_Full_View (P_Name));
7391 Set_Etype (P, Entity (P));
7392 P_Name := Entity (P);
7395 P_Type := Base_Type (Etype (P));
7397 if Debug_Flag_E then
7398 Write_Str ("Found prefix type to be ");
7399 Write_Entity_Info (P_Type, " "); Write_Eol;
7402 -- If the prefix's type is an access type, get to the record type
7404 if Is_Access_Type (P_Type) then
7405 P_Type := Implicitly_Designated_Type (P_Type);
7408 -- First check for components of a record object (not the
7409 -- result of a call, which is handled below).
7411 if Has_Components (P_Type)
7412 and then not Is_Overloadable (P_Name)
7413 and then not Is_Type (P_Name)
7415 -- Selected component of record. Type checking will validate
7416 -- name of selector.
7418 -- ??? Could we rewrite an implicit dereference into an explicit
7421 Analyze_Selected_Component (N);
7423 -- Reference to type name in predicate/invariant expression
7425 elsif (Is_Task_Type (P_Type) or else Is_Protected_Type (P_Type))
7426 and then not In_Open_Scopes (P_Name)
7427 and then (not Is_Concurrent_Type (Etype (P_Name))
7428 or else not In_Open_Scopes (Etype (P_Name)))
7430 -- Call to protected operation or entry. Type checking is
7431 -- needed on the prefix.
7433 Analyze_Selected_Component (N);
7435 elsif (In_Open_Scopes (P_Name)
7436 and then Ekind (P_Name) /= E_Void
7437 and then not Is_Overloadable (P_Name))
7438 or else (Is_Concurrent_Type (Etype (P_Name))
7439 and then In_Open_Scopes (Etype (P_Name)))
7441 -- Prefix denotes an enclosing loop, block, or task, i.e. an
7442 -- enclosing construct that is not a subprogram or accept.
7444 -- A special case: a protected body may call an operation
7445 -- on an external object of the same type, in which case it
7446 -- is not an expanded name. If the prefix is the type itself,
7447 -- or the context is a single synchronized object it can only
7448 -- be interpreted as an expanded name.
7450 if Is_Concurrent_Type (Etype (P_Name)) then
7452 or else Present (Anonymous_Object (Etype (P_Name)))
7454 Find_Expanded_Name (N);
7457 Analyze_Selected_Component (N);
7462 Find_Expanded_Name (N);
7465 elsif Ekind (P_Name) = E_Package then
7466 Find_Expanded_Name (N);
7468 elsif Is_Overloadable (P_Name) then
7470 -- The subprogram may be a renaming (of an enclosing scope) as
7471 -- in the case of the name of the generic within an instantiation.
7473 if Ekind_In (P_Name, E_Procedure, E_Function)
7474 and then Present (Alias (P_Name))
7475 and then Is_Generic_Instance (Alias (P_Name))
7477 P_Name := Alias (P_Name);
7480 if Is_Overloaded (P) then
7482 -- The prefix must resolve to a unique enclosing construct
7485 Found : Boolean := False;
7490 Get_First_Interp (P, Ind, It);
7491 while Present (It.Nam) loop
7492 if In_Open_Scopes (It.Nam) then
7495 "prefix must be unique enclosing scope", N);
7496 Set_Entity (N, Any_Id);
7497 Set_Etype (N, Any_Type);
7506 Get_Next_Interp (Ind, It);
7511 if In_Open_Scopes (P_Name) then
7512 Set_Entity (P, P_Name);
7513 Set_Is_Overloaded (P, False);
7514 Find_Expanded_Name (N);
7517 -- If no interpretation as an expanded name is possible, it
7518 -- must be a selected component of a record returned by a
7519 -- function call. Reformat prefix as a function call, the rest
7520 -- is done by type resolution.
7522 -- Error if the prefix is procedure or entry, as is P.X
7524 if Ekind (P_Name) /= E_Function
7526 (not Is_Overloaded (P)
7527 or else Nkind (Parent (N)) = N_Procedure_Call_Statement)
7529 -- Prefix may mention a package that is hidden by a local
7530 -- declaration: let the user know. Scan the full homonym
7531 -- chain, the candidate package may be anywhere on it.
7533 if Present (Homonym (Current_Entity (P_Name))) then
7534 P_Name := Current_Entity (P_Name);
7536 while Present (P_Name) loop
7537 exit when Ekind (P_Name) = E_Package;
7538 P_Name := Homonym (P_Name);
7541 if Present (P_Name) then
7542 if not Is_Reference_In_Subunit then
7543 Error_Msg_Sloc := Sloc (Entity (Prefix (N)));
7545 ("package& is hidden by declaration#", N, P_Name);
7548 Set_Entity (Prefix (N), P_Name);
7549 Find_Expanded_Name (N);
7553 P_Name := Entity (Prefix (N));
7558 ("invalid prefix in selected component&", N, P_Name);
7559 Change_Selected_Component_To_Expanded_Name (N);
7560 Set_Entity (N, Any_Id);
7561 Set_Etype (N, Any_Type);
7563 -- Here we have a function call, so do the reformatting
7566 Nam := New_Copy (P);
7567 Save_Interps (P, Nam);
7569 -- We use Replace here because this is one of those cases
7570 -- where the parser has missclassified the node, and we fix
7571 -- things up and then do the semantic analysis on the fixed
7572 -- up node. Normally we do this using one of the Sinfo.CN
7573 -- routines, but this is too tricky for that.
7575 -- Note that using Rewrite would be wrong, because we would
7576 -- have a tree where the original node is unanalyzed.
7579 Make_Function_Call (Sloc (P), Name => Nam));
7581 -- Now analyze the reformatted node
7585 -- If the prefix is illegal after this transformation, there
7586 -- may be visibility errors on the prefix. The safest is to
7587 -- treat the selected component as an error.
7589 if Error_Posted (P) then
7590 Set_Etype (N, Any_Type);
7594 Analyze_Selected_Component (N);
7599 -- Remaining cases generate various error messages
7602 -- Format node as expanded name, to avoid cascaded errors
7604 Change_Selected_Component_To_Expanded_Name (N);
7605 Set_Entity (N, Any_Id);
7606 Set_Etype (N, Any_Type);
7608 -- Issue error message, but avoid this if error issued already.
7609 -- Use identifier of prefix if one is available.
7611 if P_Name = Any_Id then
7614 -- It is not an error if the prefix is the current instance of
7615 -- type name, e.g. the expression of a type aspect, when it is
7616 -- analyzed within a generic unit. We still have to verify that a
7617 -- component of that name exists, and decorate the node
7620 elsif Is_Entity_Name (P) and then Is_Current_Instance (P) then
7625 Comp := First_Entity (Entity (P));
7626 while Present (Comp) loop
7627 if Chars (Comp) = Chars (Selector_Name (N)) then
7628 Set_Entity (N, Comp);
7629 Set_Etype (N, Etype (Comp));
7630 Set_Entity (Selector_Name (N), Comp);
7631 Set_Etype (Selector_Name (N), Etype (Comp));
7639 elsif Ekind (P_Name) = E_Void then
7640 Premature_Usage (P);
7642 elsif Nkind (P) /= N_Attribute_Reference then
7644 -- This may have been meant as a prefixed call to a primitive
7645 -- of an untagged type. If it is a function call check type of
7646 -- its first formal and add explanation.
7649 F : constant Entity_Id :=
7650 Current_Entity (Selector_Name (N));
7653 and then Is_Overloadable (F)
7654 and then Present (First_Entity (F))
7655 and then not Is_Tagged_Type (Etype (First_Entity (F)))
7658 ("prefixed call is only allowed for objects of a "
7659 & "tagged type", N);
7663 Error_Msg_N ("invalid prefix in selected component&", P);
7665 if Is_Incomplete_Type (P_Type)
7666 and then Is_Access_Type (Etype (P))
7669 ("\dereference must not be of an incomplete type "
7670 & "(RM 3.10.1)", P);
7674 Error_Msg_N ("invalid prefix in selected component", P);
7678 -- If prefix is not the name of an entity, it must be an expression,
7679 -- whose type is appropriate for a record. This is determined by
7682 Analyze_Selected_Component (N);
7685 Analyze_Dimension (N);
7686 end Find_Selected_Component;
7692 procedure Find_Type (N : Node_Id) is
7702 elsif Nkind (N) = N_Attribute_Reference then
7704 -- Class attribute. This is not valid in Ada 83 mode, but we do not
7705 -- need to enforce that at this point, since the declaration of the
7706 -- tagged type in the prefix would have been flagged already.
7708 if Attribute_Name (N) = Name_Class then
7709 Check_Restriction (No_Dispatch, N);
7710 Find_Type (Prefix (N));
7712 -- Propagate error from bad prefix
7714 if Etype (Prefix (N)) = Any_Type then
7715 Set_Entity (N, Any_Type);
7716 Set_Etype (N, Any_Type);
7720 T := Base_Type (Entity (Prefix (N)));
7722 -- Case where type is not known to be tagged. Its appearance in
7723 -- the prefix of the 'Class attribute indicates that the full view
7726 if not Is_Tagged_Type (T) then
7727 if Ekind (T) = E_Incomplete_Type then
7729 -- It is legal to denote the class type of an incomplete
7730 -- type. The full type will have to be tagged, of course.
7731 -- In Ada 2005 this usage is declared obsolescent, so we
7732 -- warn accordingly. This usage is only legal if the type
7733 -- is completed in the current scope, and not for a limited
7736 if Ada_Version >= Ada_2005 then
7738 -- Test whether the Available_View of a limited type view
7739 -- is tagged, since the limited view may not be marked as
7740 -- tagged if the type itself has an untagged incomplete
7741 -- type view in its package.
7743 if From_Limited_With (T)
7744 and then not Is_Tagged_Type (Available_View (T))
7747 ("prefix of Class attribute must be tagged", N);
7748 Set_Etype (N, Any_Type);
7749 Set_Entity (N, Any_Type);
7752 -- ??? This test is temporarily disabled (always
7753 -- False) because it causes an unwanted warning on
7754 -- GNAT sources (built with -gnatg, which includes
7755 -- Warn_On_Obsolescent_ Feature). Once this issue
7756 -- is cleared in the sources, it can be enabled.
7758 elsif Warn_On_Obsolescent_Feature and then False then
7760 ("applying 'Class to an untagged incomplete type"
7761 & " is an obsolescent feature (RM J.11)?r?", N);
7765 Set_Is_Tagged_Type (T);
7766 Set_Direct_Primitive_Operations (T, New_Elmt_List);
7767 Make_Class_Wide_Type (T);
7768 Set_Entity (N, Class_Wide_Type (T));
7769 Set_Etype (N, Class_Wide_Type (T));
7771 elsif Ekind (T) = E_Private_Type
7772 and then not Is_Generic_Type (T)
7773 and then In_Private_Part (Scope (T))
7775 -- The Class attribute can be applied to an untagged private
7776 -- type fulfilled by a tagged type prior to the full type
7777 -- declaration (but only within the parent package's private
7778 -- part). Create the class-wide type now and check that the
7779 -- full type is tagged later during its analysis. Note that
7780 -- we do not mark the private type as tagged, unlike the
7781 -- case of incomplete types, because the type must still
7782 -- appear untagged to outside units.
7784 if No (Class_Wide_Type (T)) then
7785 Make_Class_Wide_Type (T);
7788 Set_Entity (N, Class_Wide_Type (T));
7789 Set_Etype (N, Class_Wide_Type (T));
7792 -- Should we introduce a type Any_Tagged and use Wrong_Type
7793 -- here, it would be a bit more consistent???
7796 ("tagged type required, found}",
7797 Prefix (N), First_Subtype (T));
7798 Set_Entity (N, Any_Type);
7802 -- Case of tagged type
7805 if Is_Concurrent_Type (T) then
7806 if No (Corresponding_Record_Type (Entity (Prefix (N)))) then
7808 -- Previous error. Create a class-wide type for the
7809 -- synchronized type itself, with minimal semantic
7810 -- attributes, to catch other errors in some ACATS tests.
7812 pragma Assert (Serious_Errors_Detected /= 0);
7813 Make_Class_Wide_Type (T);
7814 C := Class_Wide_Type (T);
7815 Set_First_Entity (C, First_Entity (T));
7818 C := Class_Wide_Type
7819 (Corresponding_Record_Type (Entity (Prefix (N))));
7823 C := Class_Wide_Type (Entity (Prefix (N)));
7826 Set_Entity_With_Checks (N, C);
7827 Generate_Reference (C, N);
7831 -- Base attribute, not allowed in Ada 83
7833 elsif Attribute_Name (N) = Name_Base then
7834 if Ada_Version = Ada_83 and then Comes_From_Source (N) then
7836 ("(Ada 83) Base attribute not allowed in subtype mark", N);
7839 Find_Type (Prefix (N));
7840 Typ := Entity (Prefix (N));
7842 if Ada_Version >= Ada_95
7843 and then not Is_Scalar_Type (Typ)
7844 and then not Is_Generic_Type (Typ)
7847 ("prefix of Base attribute must be scalar type",
7850 elsif Warn_On_Redundant_Constructs
7851 and then Base_Type (Typ) = Typ
7853 Error_Msg_NE -- CODEFIX
7854 ("redundant attribute, & is its own base type?r?", N, Typ);
7857 T := Base_Type (Typ);
7859 -- Rewrite attribute reference with type itself (see similar
7860 -- processing in Analyze_Attribute, case Base). Preserve prefix
7861 -- if present, for other legality checks.
7863 if Nkind (Prefix (N)) = N_Expanded_Name then
7865 Make_Expanded_Name (Sloc (N),
7867 Prefix => New_Copy (Prefix (Prefix (N))),
7868 Selector_Name => New_Occurrence_Of (T, Sloc (N))));
7871 Rewrite (N, New_Occurrence_Of (T, Sloc (N)));
7878 elsif Attribute_Name (N) = Name_Stub_Type then
7880 -- This is handled in Analyze_Attribute
7884 -- All other attributes are invalid in a subtype mark
7887 Error_Msg_N ("invalid attribute in subtype mark", N);
7893 if Is_Entity_Name (N) then
7894 T_Name := Entity (N);
7896 Error_Msg_N ("subtype mark required in this context", N);
7897 Set_Etype (N, Any_Type);
7901 if T_Name = Any_Id or else Etype (N) = Any_Type then
7903 -- Undefined id. Make it into a valid type
7905 Set_Entity (N, Any_Type);
7907 elsif not Is_Type (T_Name)
7908 and then T_Name /= Standard_Void_Type
7910 Error_Msg_Sloc := Sloc (T_Name);
7911 Error_Msg_N ("subtype mark required in this context", N);
7912 Error_Msg_NE ("\\found & declared#", N, T_Name);
7913 Set_Entity (N, Any_Type);
7916 -- If the type is an incomplete type created to handle
7917 -- anonymous access components of a record type, then the
7918 -- incomplete type is the visible entity and subsequent
7919 -- references will point to it. Mark the original full
7920 -- type as referenced, to prevent spurious warnings.
7922 if Is_Incomplete_Type (T_Name)
7923 and then Present (Full_View (T_Name))
7924 and then not Comes_From_Source (T_Name)
7926 Set_Referenced (Full_View (T_Name));
7929 T_Name := Get_Full_View (T_Name);
7931 -- Ada 2005 (AI-251, AI-50217): Handle interfaces visible through
7932 -- limited-with clauses
7934 if From_Limited_With (T_Name)
7935 and then Is_Incomplete_Type (T_Name)
7936 and then Present (Non_Limited_View (T_Name))
7937 and then Is_Interface (Non_Limited_View (T_Name))
7939 T_Name := Non_Limited_View (T_Name);
7942 if In_Open_Scopes (T_Name) then
7943 if Ekind (Base_Type (T_Name)) = E_Task_Type then
7945 -- In Ada 2005, a task name can be used in an access
7946 -- definition within its own body. It cannot be used
7947 -- in the discriminant part of the task declaration,
7948 -- nor anywhere else in the declaration because entries
7949 -- cannot have access parameters.
7951 if Ada_Version >= Ada_2005
7952 and then Nkind (Parent (N)) = N_Access_Definition
7954 Set_Entity (N, T_Name);
7955 Set_Etype (N, T_Name);
7957 if Has_Completion (T_Name) then
7962 ("task type cannot be used as type mark " &
7963 "within its own declaration", N);
7968 ("task type cannot be used as type mark " &
7969 "within its own spec or body", N);
7972 elsif Ekind (Base_Type (T_Name)) = E_Protected_Type then
7974 -- In Ada 2005, a protected name can be used in an access
7975 -- definition within its own body.
7977 if Ada_Version >= Ada_2005
7978 and then Nkind (Parent (N)) = N_Access_Definition
7980 Set_Entity (N, T_Name);
7981 Set_Etype (N, T_Name);
7986 ("protected type cannot be used as type mark " &
7987 "within its own spec or body", N);
7991 Error_Msg_N ("type declaration cannot refer to itself", N);
7994 Set_Etype (N, Any_Type);
7995 Set_Entity (N, Any_Type);
7996 Set_Error_Posted (T_Name);
8000 Set_Entity (N, T_Name);
8001 Set_Etype (N, T_Name);
8005 if Present (Etype (N)) and then Comes_From_Source (N) then
8006 if Is_Fixed_Point_Type (Etype (N)) then
8007 Check_Restriction (No_Fixed_Point, N);
8008 elsif Is_Floating_Point_Type (Etype (N)) then
8009 Check_Restriction (No_Floating_Point, N);
8012 -- A Ghost type must appear in a specific context
8014 if Is_Ghost_Entity (Etype (N)) then
8015 Check_Ghost_Context (Etype (N), N);
8020 --------------------
8021 -- Has_Components --
8022 --------------------
8024 function Has_Components (Typ : Entity_Id) return Boolean is
8026 return Is_Record_Type (Typ)
8027 or else (Is_Private_Type (Typ) and then Has_Discriminants (Typ))
8028 or else (Is_Task_Type (Typ) and then Has_Discriminants (Typ))
8029 or else (Is_Incomplete_Type (Typ)
8030 and then From_Limited_With (Typ)
8031 and then Is_Record_Type (Available_View (Typ)));
8034 ------------------------------------
8035 -- Has_Implicit_Character_Literal --
8036 ------------------------------------
8038 function Has_Implicit_Character_Literal (N : Node_Id) return Boolean is
8040 Found : Boolean := False;
8041 P : constant Entity_Id := Entity (Prefix (N));
8042 Priv_Id : Entity_Id := Empty;
8045 if Ekind (P) = E_Package and then not In_Open_Scopes (P) then
8046 Priv_Id := First_Private_Entity (P);
8049 if P = Standard_Standard then
8050 Change_Selected_Component_To_Expanded_Name (N);
8051 Rewrite (N, Selector_Name (N));
8053 Set_Etype (Original_Node (N), Standard_Character);
8057 Id := First_Entity (P);
8058 while Present (Id) and then Id /= Priv_Id loop
8059 if Is_Standard_Character_Type (Id) and then Is_Base_Type (Id) then
8061 -- We replace the node with the literal itself, resolve as a
8062 -- character, and set the type correctly.
8065 Change_Selected_Component_To_Expanded_Name (N);
8066 Rewrite (N, Selector_Name (N));
8069 Set_Etype (Original_Node (N), Id);
8073 -- More than one type derived from Character in given scope.
8074 -- Collect all possible interpretations.
8076 Add_One_Interp (N, Id, Id);
8084 end Has_Implicit_Character_Literal;
8086 ----------------------
8087 -- Has_Private_With --
8088 ----------------------
8090 function Has_Private_With (E : Entity_Id) return Boolean is
8091 Comp_Unit : constant Node_Id := Cunit (Current_Sem_Unit);
8095 Item := First (Context_Items (Comp_Unit));
8096 while Present (Item) loop
8097 if Nkind (Item) = N_With_Clause
8098 and then Private_Present (Item)
8099 and then Entity (Name (Item)) = E
8108 end Has_Private_With;
8110 ---------------------------
8111 -- Has_Implicit_Operator --
8112 ---------------------------
8114 function Has_Implicit_Operator (N : Node_Id) return Boolean is
8115 Op_Id : constant Name_Id := Chars (Selector_Name (N));
8116 P : constant Entity_Id := Entity (Prefix (N));
8118 Priv_Id : Entity_Id := Empty;
8120 procedure Add_Implicit_Operator
8122 Op_Type : Entity_Id := Empty);
8123 -- Add implicit interpretation to node N, using the type for which a
8124 -- predefined operator exists. If the operator yields a boolean type,
8125 -- the Operand_Type is implicitly referenced by the operator, and a
8126 -- reference to it must be generated.
8128 ---------------------------
8129 -- Add_Implicit_Operator --
8130 ---------------------------
8132 procedure Add_Implicit_Operator
8134 Op_Type : Entity_Id := Empty)
8136 Predef_Op : Entity_Id;
8139 Predef_Op := Current_Entity (Selector_Name (N));
8140 while Present (Predef_Op)
8141 and then Scope (Predef_Op) /= Standard_Standard
8143 Predef_Op := Homonym (Predef_Op);
8146 if Nkind (N) = N_Selected_Component then
8147 Change_Selected_Component_To_Expanded_Name (N);
8150 -- If the context is an unanalyzed function call, determine whether
8151 -- a binary or unary interpretation is required.
8153 if Nkind (Parent (N)) = N_Indexed_Component then
8155 Is_Binary_Call : constant Boolean :=
8157 (Next (First (Expressions (Parent (N)))));
8158 Is_Binary_Op : constant Boolean :=
8160 (Predef_Op) /= Last_Entity (Predef_Op);
8161 Predef_Op2 : constant Entity_Id := Homonym (Predef_Op);
8164 if Is_Binary_Call then
8165 if Is_Binary_Op then
8166 Add_One_Interp (N, Predef_Op, T);
8168 Add_One_Interp (N, Predef_Op2, T);
8172 if not Is_Binary_Op then
8173 Add_One_Interp (N, Predef_Op, T);
8175 Add_One_Interp (N, Predef_Op2, T);
8181 Add_One_Interp (N, Predef_Op, T);
8183 -- For operators with unary and binary interpretations, if
8184 -- context is not a call, add both
8186 if Present (Homonym (Predef_Op)) then
8187 Add_One_Interp (N, Homonym (Predef_Op), T);
8191 -- The node is a reference to a predefined operator, and
8192 -- an implicit reference to the type of its operands.
8194 if Present (Op_Type) then
8195 Generate_Operator_Reference (N, Op_Type);
8197 Generate_Operator_Reference (N, T);
8199 end Add_Implicit_Operator;
8201 -- Start of processing for Has_Implicit_Operator
8204 if Ekind (P) = E_Package and then not In_Open_Scopes (P) then
8205 Priv_Id := First_Private_Entity (P);
8208 Id := First_Entity (P);
8212 -- Boolean operators: an implicit declaration exists if the scope
8213 -- contains a declaration for a derived Boolean type, or for an
8214 -- array of Boolean type.
8221 while Id /= Priv_Id loop
8222 if Valid_Boolean_Arg (Id) and then Is_Base_Type (Id) then
8223 Add_Implicit_Operator (Id);
8230 -- Equality: look for any non-limited type (result is Boolean)
8235 while Id /= Priv_Id loop
8237 and then not Is_Limited_Type (Id)
8238 and then Is_Base_Type (Id)
8240 Add_Implicit_Operator (Standard_Boolean, Id);
8247 -- Comparison operators: scalar type, or array of scalar
8254 while Id /= Priv_Id loop
8255 if (Is_Scalar_Type (Id)
8256 or else (Is_Array_Type (Id)
8257 and then Is_Scalar_Type (Component_Type (Id))))
8258 and then Is_Base_Type (Id)
8260 Add_Implicit_Operator (Standard_Boolean, Id);
8267 -- Arithmetic operators: any numeric type
8278 while Id /= Priv_Id loop
8279 if Is_Numeric_Type (Id) and then Is_Base_Type (Id) then
8280 Add_Implicit_Operator (Id);
8287 -- Concatenation: any one-dimensional array type
8289 when Name_Op_Concat =>
8290 while Id /= Priv_Id loop
8291 if Is_Array_Type (Id)
8292 and then Number_Dimensions (Id) = 1
8293 and then Is_Base_Type (Id)
8295 Add_Implicit_Operator (Id);
8302 -- What is the others condition here? Should we be using a
8303 -- subtype of Name_Id that would restrict to operators ???
8309 -- If we fall through, then we do not have an implicit operator
8312 end Has_Implicit_Operator;
8314 -----------------------------------
8315 -- Has_Loop_In_Inner_Open_Scopes --
8316 -----------------------------------
8318 function Has_Loop_In_Inner_Open_Scopes (S : Entity_Id) return Boolean is
8320 -- Several scope stacks are maintained by Scope_Stack. The base of the
8321 -- currently active scope stack is denoted by the Is_Active_Stack_Base
8322 -- flag in the scope stack entry. Note that the scope stacks used to
8323 -- simply be delimited implicitly by the presence of Standard_Standard
8324 -- at their base, but there now are cases where this is not sufficient
8325 -- because Standard_Standard actually may appear in the middle of the
8326 -- active set of scopes.
8328 for J in reverse 0 .. Scope_Stack.Last loop
8330 -- S was reached without seing a loop scope first
8332 if Scope_Stack.Table (J).Entity = S then
8335 -- S was not yet reached, so it contains at least one inner loop
8337 elsif Ekind (Scope_Stack.Table (J).Entity) = E_Loop then
8341 -- Check Is_Active_Stack_Base to tell us when to stop, as there are
8342 -- cases where Standard_Standard appears in the middle of the active
8343 -- set of scopes. This affects the declaration and overriding of
8344 -- private inherited operations in instantiations of generic child
8347 pragma Assert (not Scope_Stack.Table (J).Is_Active_Stack_Base);
8350 raise Program_Error; -- unreachable
8351 end Has_Loop_In_Inner_Open_Scopes;
8353 --------------------
8354 -- In_Open_Scopes --
8355 --------------------
8357 function In_Open_Scopes (S : Entity_Id) return Boolean is
8359 -- Several scope stacks are maintained by Scope_Stack. The base of the
8360 -- currently active scope stack is denoted by the Is_Active_Stack_Base
8361 -- flag in the scope stack entry. Note that the scope stacks used to
8362 -- simply be delimited implicitly by the presence of Standard_Standard
8363 -- at their base, but there now are cases where this is not sufficient
8364 -- because Standard_Standard actually may appear in the middle of the
8365 -- active set of scopes.
8367 for J in reverse 0 .. Scope_Stack.Last loop
8368 if Scope_Stack.Table (J).Entity = S then
8372 -- Check Is_Active_Stack_Base to tell us when to stop, as there are
8373 -- cases where Standard_Standard appears in the middle of the active
8374 -- set of scopes. This affects the declaration and overriding of
8375 -- private inherited operations in instantiations of generic child
8378 exit when Scope_Stack.Table (J).Is_Active_Stack_Base;
8384 -----------------------------
8385 -- Inherit_Renamed_Profile --
8386 -----------------------------
8388 procedure Inherit_Renamed_Profile (New_S : Entity_Id; Old_S : Entity_Id) is
8395 if Ekind (Old_S) = E_Operator then
8396 New_F := First_Formal (New_S);
8398 while Present (New_F) loop
8399 Set_Etype (New_F, Base_Type (Etype (New_F)));
8400 Next_Formal (New_F);
8403 Set_Etype (New_S, Base_Type (Etype (New_S)));
8406 New_F := First_Formal (New_S);
8407 Old_F := First_Formal (Old_S);
8409 while Present (New_F) loop
8410 New_T := Etype (New_F);
8411 Old_T := Etype (Old_F);
8413 -- If the new type is a renaming of the old one, as is the case
8414 -- for actuals in instances, retain its name, to simplify later
8417 if Nkind (Parent (New_T)) = N_Subtype_Declaration
8418 and then Is_Entity_Name (Subtype_Indication (Parent (New_T)))
8419 and then Entity (Subtype_Indication (Parent (New_T))) = Old_T
8423 Set_Etype (New_F, Old_T);
8426 Next_Formal (New_F);
8427 Next_Formal (Old_F);
8430 pragma Assert (No (Old_F));
8432 if Ekind_In (Old_S, E_Function, E_Enumeration_Literal) then
8433 Set_Etype (New_S, Etype (Old_S));
8436 end Inherit_Renamed_Profile;
8442 procedure Initialize is
8447 -------------------------
8448 -- Install_Use_Clauses --
8449 -------------------------
8451 procedure Install_Use_Clauses
8453 Force_Installation : Boolean := False)
8459 while Present (U) loop
8461 -- Case of USE package
8463 if Nkind (U) = N_Use_Package_Clause then
8464 Use_One_Package (U, Name (U), True);
8469 Use_One_Type (Subtype_Mark (U), Force => Force_Installation);
8473 Next_Use_Clause (U);
8475 end Install_Use_Clauses;
8477 ----------------------
8478 -- Mark_Use_Clauses --
8479 ----------------------
8481 procedure Mark_Use_Clauses (Id : Node_Or_Entity_Id) is
8482 procedure Mark_Parameters (Call : Entity_Id);
8483 -- Perform use_type_clause marking for all parameters in a subprogram
8484 -- or operator call.
8486 procedure Mark_Use_Package (Pak : Entity_Id);
8487 -- Move up the Prev_Use_Clause chain for packages denoted by Pak -
8488 -- marking each clause in the chain as effective in the process.
8490 procedure Mark_Use_Type (E : Entity_Id);
8491 -- Similar to Do_Use_Package_Marking except we move up the
8492 -- Prev_Use_Clause chain for the type denoted by E.
8494 ---------------------
8495 -- Mark_Parameters --
8496 ---------------------
8498 procedure Mark_Parameters (Call : Entity_Id) is
8502 -- Move through all of the formals
8504 Curr := First_Formal (Call);
8505 while Present (Curr) loop
8506 Mark_Use_Type (Curr);
8511 -- Handle the return type
8513 Mark_Use_Type (Call);
8514 end Mark_Parameters;
8516 ----------------------
8517 -- Mark_Use_Package --
8518 ----------------------
8520 procedure Mark_Use_Package (Pak : Entity_Id) is
8524 -- Ignore cases where the scope of the type is not a package (e.g.
8525 -- Standard_Standard).
8527 if Ekind (Pak) /= E_Package then
8531 Curr := Current_Use_Clause (Pak);
8532 while Present (Curr)
8533 and then not Is_Effective_Use_Clause (Curr)
8535 -- We need to mark the previous use clauses as effective, but
8536 -- each use clause may in turn render other use_package_clauses
8537 -- effective. Additionally, it is possible to have a parent
8538 -- package renamed as a child of itself so we must check the
8539 -- prefix entity is not the same as the package we are marking.
8541 if Nkind (Name (Curr)) /= N_Identifier
8542 and then Present (Prefix (Name (Curr)))
8543 and then Entity (Prefix (Name (Curr))) /= Pak
8545 Mark_Use_Package (Entity (Prefix (Name (Curr))));
8547 -- It is also possible to have a child package without a prefix
8548 -- that relies on a previous use_package_clause.
8550 elsif Nkind (Name (Curr)) = N_Identifier
8551 and then Is_Child_Unit (Entity (Name (Curr)))
8553 Mark_Use_Package (Scope (Entity (Name (Curr))));
8556 -- Mark the use_package_clause as effective and move up the chain
8558 Set_Is_Effective_Use_Clause (Curr);
8560 Curr := Prev_Use_Clause (Curr);
8562 end Mark_Use_Package;
8568 procedure Mark_Use_Type (E : Entity_Id) is
8573 -- Ignore void types and unresolved string literals and primitives
8575 if Nkind (E) = N_String_Literal
8576 or else Nkind (Etype (E)) not in N_Entity
8577 or else not Is_Type (Etype (E))
8582 -- Primitives with class-wide operands might additionally render
8583 -- their base type's use_clauses effective - so do a recursive check
8586 Base := Base_Type (Etype (E));
8588 if Ekind (Base) = E_Class_Wide_Type then
8589 Mark_Use_Type (Base);
8592 -- The package containing the type or operator function being used
8593 -- may be in use as well, so mark any use_package_clauses for it as
8594 -- effective. There are also additional sanity checks performed here
8595 -- for ignoring previous errors.
8597 Mark_Use_Package (Scope (Base));
8599 if Nkind (E) in N_Op
8600 and then Present (Entity (E))
8601 and then Present (Scope (Entity (E)))
8603 Mark_Use_Package (Scope (Entity (E)));
8606 Curr := Current_Use_Clause (Base);
8607 while Present (Curr)
8608 and then not Is_Effective_Use_Clause (Curr)
8610 -- Current use_type_clause may render other use_package_clauses
8613 if Nkind (Subtype_Mark (Curr)) /= N_Identifier
8614 and then Present (Prefix (Subtype_Mark (Curr)))
8616 Mark_Use_Package (Entity (Prefix (Subtype_Mark (Curr))));
8619 -- Mark the use_type_clause as effective and move up the chain
8621 Set_Is_Effective_Use_Clause (Curr);
8623 Curr := Prev_Use_Clause (Curr);
8627 -- Start of processing for Mark_Use_Clauses
8630 -- Use clauses in and of themselves do not count as a "use" of a
8633 if Nkind_In (Parent (Id), N_Use_Package_Clause, N_Use_Type_Clause) then
8639 if Nkind (Id) in N_Entity then
8641 -- Mark the entity's package
8643 if Is_Potentially_Use_Visible (Id) then
8644 Mark_Use_Package (Scope (Id));
8647 -- Mark enumeration literals
8649 if Ekind (Id) = E_Enumeration_Literal then
8654 elsif (Ekind (Id) in Overloadable_Kind
8655 or else Ekind_In (Id, E_Generic_Function,
8656 E_Generic_Procedure))
8657 and then (Is_Potentially_Use_Visible (Id)
8658 or else Is_Intrinsic_Subprogram (Id)
8659 or else (Ekind_In (Id, E_Function, E_Procedure)
8660 and then Is_Generic_Actual_Subprogram (Id)))
8662 Mark_Parameters (Id);
8670 if Nkind (Id) in N_Op then
8672 -- At this point the left operand may not be resolved if we are
8673 -- encountering multiple operators next to eachother in an
8676 if Nkind (Id) in N_Binary_Op
8677 and then not (Nkind (Left_Opnd (Id)) in N_Op)
8679 Mark_Use_Type (Left_Opnd (Id));
8682 Mark_Use_Type (Right_Opnd (Id));
8685 -- Mark entity identifiers
8687 elsif Nkind (Id) in N_Has_Entity
8688 and then (Is_Potentially_Use_Visible (Entity (Id))
8689 or else (Is_Generic_Instance (Entity (Id))
8690 and then Is_Immediately_Visible (Entity (Id))))
8692 -- Ignore fully qualified names as they do not count as a "use" of
8695 if Nkind_In (Id, N_Identifier, N_Operator_Symbol)
8696 or else (Present (Prefix (Id))
8697 and then Scope (Entity (Id)) /= Entity (Prefix (Id)))
8699 Mark_Use_Clauses (Entity (Id));
8703 end Mark_Use_Clauses;
8705 --------------------------------
8706 -- Most_Descendant_Use_Clause --
8707 --------------------------------
8709 function Most_Descendant_Use_Clause
8710 (Clause1 : Entity_Id;
8711 Clause2 : Entity_Id) return Entity_Id
8717 if Clause1 = Clause2 then
8721 -- We determine which one is the most descendant by the scope distance
8722 -- to the ultimate parent unit.
8724 Scope1 := Entity_Of_Unit (Unit (Parent (Clause1)));
8725 Scope2 := Entity_Of_Unit (Unit (Parent (Clause2)));
8726 while Scope1 /= Standard_Standard
8727 and then Scope2 /= Standard_Standard
8729 Scope1 := Scope (Scope1);
8730 Scope2 := Scope (Scope2);
8732 if not Present (Scope1) then
8734 elsif not Present (Scope2) then
8739 if Scope1 = Standard_Standard then
8744 end Most_Descendant_Use_Clause;
8750 procedure Pop_Scope is
8751 SST : Scope_Stack_Entry renames Scope_Stack.Table (Scope_Stack.Last);
8752 S : constant Entity_Id := SST.Entity;
8755 if Debug_Flag_E then
8759 -- Set Default_Storage_Pool field of the library unit if necessary
8761 if Is_Package_Or_Generic_Package (S)
8763 Nkind (Parent (Unit_Declaration_Node (S))) = N_Compilation_Unit
8766 Aux : constant Node_Id :=
8767 Aux_Decls_Node (Parent (Unit_Declaration_Node (S)));
8769 if No (Default_Storage_Pool (Aux)) then
8770 Set_Default_Storage_Pool (Aux, Default_Pool);
8775 Scope_Suppress := SST.Save_Scope_Suppress;
8776 Local_Suppress_Stack_Top := SST.Save_Local_Suppress_Stack_Top;
8777 Check_Policy_List := SST.Save_Check_Policy_List;
8778 Default_Pool := SST.Save_Default_Storage_Pool;
8779 No_Tagged_Streams := SST.Save_No_Tagged_Streams;
8780 SPARK_Mode := SST.Save_SPARK_Mode;
8781 SPARK_Mode_Pragma := SST.Save_SPARK_Mode_Pragma;
8782 Default_SSO := SST.Save_Default_SSO;
8783 Uneval_Old := SST.Save_Uneval_Old;
8785 if Debug_Flag_W then
8786 Write_Str ("<-- exiting scope: ");
8787 Write_Name (Chars (Current_Scope));
8788 Write_Str (", Depth=");
8789 Write_Int (Int (Scope_Stack.Last));
8793 End_Use_Clauses (SST.First_Use_Clause);
8795 -- If the actions to be wrapped are still there they will get lost
8796 -- causing incomplete code to be generated. It is better to abort in
8797 -- this case (and we do the abort even with assertions off since the
8798 -- penalty is incorrect code generation).
8800 if SST.Actions_To_Be_Wrapped /= Scope_Actions'(others => No_List) then
8801 raise Program_Error;
8804 -- Free last subprogram name if allocated, and pop scope
8806 Free (SST.Last_Subprogram_Name);
8807 Scope_Stack.Decrement_Last;
8814 procedure Push_Scope (S : Entity_Id) is
8815 E : constant Entity_Id := Scope (S);
8818 if Ekind (S) = E_Void then
8821 -- Set scope depth if not a non-concurrent type, and we have not yet set
8822 -- the scope depth. This means that we have the first occurrence of the
8823 -- scope, and this is where the depth is set.
8825 elsif (not Is_Type (S) or else Is_Concurrent_Type (S))
8826 and then not Scope_Depth_Set (S)
8828 if S = Standard_Standard then
8829 Set_Scope_Depth_Value (S, Uint_0);
8831 elsif Is_Child_Unit (S) then
8832 Set_Scope_Depth_Value (S, Uint_1);
8834 elsif not Is_Record_Type (Current_Scope) then
8835 if Ekind (S) = E_Loop then
8836 Set_Scope_Depth_Value (S, Scope_Depth (Current_Scope));
8838 Set_Scope_Depth_Value (S, Scope_Depth (Current_Scope) + 1);
8843 Scope_Stack.Increment_Last;
8846 SST : Scope_Stack_Entry renames Scope_Stack.Table (Scope_Stack.Last);
8850 SST.Save_Scope_Suppress := Scope_Suppress;
8851 SST.Save_Local_Suppress_Stack_Top := Local_Suppress_Stack_Top;
8852 SST.Save_Check_Policy_List := Check_Policy_List;
8853 SST.Save_Default_Storage_Pool := Default_Pool;
8854 SST.Save_No_Tagged_Streams := No_Tagged_Streams;
8855 SST.Save_SPARK_Mode := SPARK_Mode;
8856 SST.Save_SPARK_Mode_Pragma := SPARK_Mode_Pragma;
8857 SST.Save_Default_SSO := Default_SSO;
8858 SST.Save_Uneval_Old := Uneval_Old;
8860 -- Each new scope pushed onto the scope stack inherits the component
8861 -- alignment of the previous scope. This emulates the "visibility"
8862 -- semantics of pragma Component_Alignment.
8864 if Scope_Stack.Last > Scope_Stack.First then
8865 SST.Component_Alignment_Default :=
8867 (Scope_Stack.Last - 1).Component_Alignment_Default;
8869 -- Otherwise, this is the first scope being pushed on the scope
8870 -- stack. Inherit the component alignment from the configuration
8871 -- form of pragma Component_Alignment (if any).
8874 SST.Component_Alignment_Default :=
8875 Configuration_Component_Alignment;
8878 SST.Last_Subprogram_Name := null;
8879 SST.Is_Transient := False;
8880 SST.Node_To_Be_Wrapped := Empty;
8881 SST.Pending_Freeze_Actions := No_List;
8882 SST.Actions_To_Be_Wrapped := (others => No_List);
8883 SST.First_Use_Clause := Empty;
8884 SST.Is_Active_Stack_Base := False;
8885 SST.Previous_Visibility := False;
8886 SST.Locked_Shared_Objects := No_Elist;
8889 if Debug_Flag_W then
8890 Write_Str ("--> new scope: ");
8891 Write_Name (Chars (Current_Scope));
8892 Write_Str (", Id=");
8893 Write_Int (Int (Current_Scope));
8894 Write_Str (", Depth=");
8895 Write_Int (Int (Scope_Stack.Last));
8899 -- Deal with copying flags from the previous scope to this one. This is
8900 -- not necessary if either scope is standard, or if the new scope is a
8903 if S /= Standard_Standard
8904 and then Scope (S) /= Standard_Standard
8905 and then not Is_Child_Unit (S)
8907 if Nkind (E) not in N_Entity then
8911 -- Copy categorization flags from Scope (S) to S, this is not done
8912 -- when Scope (S) is Standard_Standard since propagation is from
8913 -- library unit entity inwards. Copy other relevant attributes as
8914 -- well (Discard_Names in particular).
8916 -- We only propagate inwards for library level entities,
8917 -- inner level subprograms do not inherit the categorization.
8919 if Is_Library_Level_Entity (S) then
8920 Set_Is_Preelaborated (S, Is_Preelaborated (E));
8921 Set_Is_Shared_Passive (S, Is_Shared_Passive (E));
8922 Set_Discard_Names (S, Discard_Names (E));
8923 Set_Suppress_Value_Tracking_On_Call
8924 (S, Suppress_Value_Tracking_On_Call (E));
8925 Set_Categorization_From_Scope (E => S, Scop => E);
8929 if Is_Child_Unit (S)
8930 and then Present (E)
8931 and then Is_Package_Or_Generic_Package (E)
8933 Nkind (Parent (Unit_Declaration_Node (E))) = N_Compilation_Unit
8936 Aux : constant Node_Id :=
8937 Aux_Decls_Node (Parent (Unit_Declaration_Node (E)));
8939 if Present (Default_Storage_Pool (Aux)) then
8940 Default_Pool := Default_Storage_Pool (Aux);
8946 ---------------------
8947 -- Premature_Usage --
8948 ---------------------
8950 procedure Premature_Usage (N : Node_Id) is
8951 Kind : constant Node_Kind := Nkind (Parent (Entity (N)));
8952 E : Entity_Id := Entity (N);
8955 -- Within an instance, the analysis of the actual for a formal object
8956 -- does not see the name of the object itself. This is significant only
8957 -- if the object is an aggregate, where its analysis does not do any
8958 -- name resolution on component associations. (see 4717-008). In such a
8959 -- case, look for the visible homonym on the chain.
8961 if In_Instance and then Present (Homonym (E)) then
8963 while Present (E) and then not In_Open_Scopes (Scope (E)) loop
8969 Set_Etype (N, Etype (E));
8975 when N_Component_Declaration =>
8977 ("component&! cannot be used before end of record declaration",
8980 when N_Parameter_Specification =>
8982 ("formal parameter&! cannot be used before end of specification",
8985 when N_Discriminant_Specification =>
8987 ("discriminant&! cannot be used before end of discriminant part",
8990 when N_Procedure_Specification | N_Function_Specification =>
8992 ("subprogram&! cannot be used before end of its declaration",
8995 when N_Full_Type_Declaration | N_Subtype_Declaration =>
8997 ("type& cannot be used before end of its declaration!", N);
9001 ("object& cannot be used before end of its declaration!", N);
9003 -- If the premature reference appears as the expression in its own
9004 -- declaration, rewrite it to prevent compiler loops in subsequent
9005 -- uses of this mangled declaration in address clauses.
9007 if Nkind (Parent (N)) = N_Object_Declaration then
9008 Set_Entity (N, Any_Id);
9011 end Premature_Usage;
9013 ------------------------
9014 -- Present_System_Aux --
9015 ------------------------
9017 function Present_System_Aux (N : Node_Id := Empty) return Boolean is
9019 Aux_Name : Unit_Name_Type;
9020 Unum : Unit_Number_Type;
9025 function Find_System (C_Unit : Node_Id) return Entity_Id;
9026 -- Scan context clause of compilation unit to find with_clause
9033 function Find_System (C_Unit : Node_Id) return Entity_Id is
9034 With_Clause : Node_Id;
9037 With_Clause := First (Context_Items (C_Unit));
9038 while Present (With_Clause) loop
9039 if (Nkind (With_Clause) = N_With_Clause
9040 and then Chars (Name (With_Clause)) = Name_System)
9041 and then Comes_From_Source (With_Clause)
9052 -- Start of processing for Present_System_Aux
9055 -- The child unit may have been loaded and analyzed already
9057 if Present (System_Aux_Id) then
9060 -- If no previous pragma for System.Aux, nothing to load
9062 elsif No (System_Extend_Unit) then
9065 -- Use the unit name given in the pragma to retrieve the unit.
9066 -- Verify that System itself appears in the context clause of the
9067 -- current compilation. If System is not present, an error will
9068 -- have been reported already.
9071 With_Sys := Find_System (Cunit (Current_Sem_Unit));
9073 The_Unit := Unit (Cunit (Current_Sem_Unit));
9077 (Nkind (The_Unit) = N_Package_Body
9078 or else (Nkind (The_Unit) = N_Subprogram_Body
9079 and then not Acts_As_Spec (Cunit (Current_Sem_Unit))))
9081 With_Sys := Find_System (Library_Unit (Cunit (Current_Sem_Unit)));
9084 if No (With_Sys) and then Present (N) then
9086 -- If we are compiling a subunit, we need to examine its
9087 -- context as well (Current_Sem_Unit is the parent unit);
9089 The_Unit := Parent (N);
9090 while Nkind (The_Unit) /= N_Compilation_Unit loop
9091 The_Unit := Parent (The_Unit);
9094 if Nkind (Unit (The_Unit)) = N_Subunit then
9095 With_Sys := Find_System (The_Unit);
9099 if No (With_Sys) then
9103 Loc := Sloc (With_Sys);
9104 Get_Name_String (Chars (Expression (System_Extend_Unit)));
9105 Name_Buffer (8 .. Name_Len + 7) := Name_Buffer (1 .. Name_Len);
9106 Name_Buffer (1 .. 7) := "system.";
9107 Name_Buffer (Name_Len + 8) := '%';
9108 Name_Buffer (Name_Len + 9) := 's';
9109 Name_Len := Name_Len + 9;
9110 Aux_Name := Name_Find;
9114 (Load_Name => Aux_Name,
9117 Error_Node => With_Sys);
9119 if Unum /= No_Unit then
9120 Semantics (Cunit (Unum));
9122 Defining_Entity (Specification (Unit (Cunit (Unum))));
9125 Make_With_Clause (Loc,
9127 Make_Expanded_Name (Loc,
9128 Chars => Chars (System_Aux_Id),
9130 New_Occurrence_Of (Scope (System_Aux_Id), Loc),
9131 Selector_Name => New_Occurrence_Of (System_Aux_Id, Loc)));
9133 Set_Entity (Name (Withn), System_Aux_Id);
9135 Set_Corresponding_Spec (Withn, System_Aux_Id);
9136 Set_First_Name (Withn);
9137 Set_Implicit_With (Withn);
9138 Set_Library_Unit (Withn, Cunit (Unum));
9140 Insert_After (With_Sys, Withn);
9141 Mark_Rewrite_Insertion (Withn);
9142 Set_Context_Installed (Withn);
9146 -- Here if unit load failed
9149 Error_Msg_Name_1 := Name_System;
9150 Error_Msg_Name_2 := Chars (Expression (System_Extend_Unit));
9152 ("extension package `%.%` does not exist",
9153 Opt.System_Extend_Unit);
9157 end Present_System_Aux;
9159 -------------------------
9160 -- Restore_Scope_Stack --
9161 -------------------------
9163 procedure Restore_Scope_Stack
9165 Handle_Use : Boolean := True)
9167 SS_Last : constant Int := Scope_Stack.Last;
9171 -- Restore visibility of previous scope stack, if any, using the list
9172 -- we saved (we use Remove, since this list will not be used again).
9175 Elmt := Last_Elmt (List);
9176 exit when Elmt = No_Elmt;
9177 Set_Is_Immediately_Visible (Node (Elmt));
9178 Remove_Last_Elmt (List);
9181 -- Restore use clauses
9183 if SS_Last >= Scope_Stack.First
9184 and then Scope_Stack.Table (SS_Last).Entity /= Standard_Standard
9188 (Scope_Stack.Table (SS_Last).First_Use_Clause,
9189 Force_Installation => True);
9191 end Restore_Scope_Stack;
9193 ----------------------
9194 -- Save_Scope_Stack --
9195 ----------------------
9197 -- Save_Scope_Stack/Restore_Scope_Stack were originally designed to avoid
9198 -- consuming any memory. That is, Save_Scope_Stack took care of removing
9199 -- from immediate visibility entities and Restore_Scope_Stack took care
9200 -- of restoring their visibility analyzing the context of each entity. The
9201 -- problem of such approach is that it was fragile and caused unexpected
9202 -- visibility problems, and indeed one test was found where there was a
9205 -- Furthermore, the following experiment was carried out:
9207 -- - Save_Scope_Stack was modified to store in an Elist1 all those
9208 -- entities whose attribute Is_Immediately_Visible is modified
9209 -- from True to False.
9211 -- - Restore_Scope_Stack was modified to store in another Elist2
9212 -- all the entities whose attribute Is_Immediately_Visible is
9213 -- modified from False to True.
9215 -- - Extra code was added to verify that all the elements of Elist1
9216 -- are found in Elist2
9218 -- This test shows that there may be more occurrences of this problem which
9219 -- have not yet been detected. As a result, we replaced that approach by
9220 -- the current one in which Save_Scope_Stack returns the list of entities
9221 -- whose visibility is changed, and that list is passed to Restore_Scope_
9222 -- Stack to undo that change. This approach is simpler and safer, although
9223 -- it consumes more memory.
9225 function Save_Scope_Stack (Handle_Use : Boolean := True) return Elist_Id is
9226 Result : constant Elist_Id := New_Elmt_List;
9229 SS_Last : constant Int := Scope_Stack.Last;
9231 procedure Remove_From_Visibility (E : Entity_Id);
9232 -- If E is immediately visible then append it to the result and remove
9233 -- it temporarily from visibility.
9235 ----------------------------
9236 -- Remove_From_Visibility --
9237 ----------------------------
9239 procedure Remove_From_Visibility (E : Entity_Id) is
9241 if Is_Immediately_Visible (E) then
9242 Append_Elmt (E, Result);
9243 Set_Is_Immediately_Visible (E, False);
9245 end Remove_From_Visibility;
9247 -- Start of processing for Save_Scope_Stack
9250 if SS_Last >= Scope_Stack.First
9251 and then Scope_Stack.Table (SS_Last).Entity /= Standard_Standard
9254 End_Use_Clauses (Scope_Stack.Table (SS_Last).First_Use_Clause);
9257 -- If the call is from within a compilation unit, as when called from
9258 -- Rtsfind, make current entries in scope stack invisible while we
9259 -- analyze the new unit.
9261 for J in reverse 0 .. SS_Last loop
9262 exit when Scope_Stack.Table (J).Entity = Standard_Standard
9263 or else No (Scope_Stack.Table (J).Entity);
9265 S := Scope_Stack.Table (J).Entity;
9267 Remove_From_Visibility (S);
9269 E := First_Entity (S);
9270 while Present (E) loop
9271 Remove_From_Visibility (E);
9279 end Save_Scope_Stack;
9285 procedure Set_Use (L : List_Id) is
9291 while Present (Decl) loop
9292 if Nkind (Decl) = N_Use_Package_Clause then
9293 Chain_Use_Clause (Decl);
9294 Use_One_Package (Decl, Name (Decl));
9296 elsif Nkind (Decl) = N_Use_Type_Clause then
9297 Chain_Use_Clause (Decl);
9298 Use_One_Type (Subtype_Mark (Decl));
9307 -----------------------------
9308 -- Update_Use_Clause_Chain --
9309 -----------------------------
9311 procedure Update_Use_Clause_Chain is
9313 procedure Update_Chain_In_Scope (Level : Int);
9314 -- Iterate through one level in the scope stack verifying each use-type
9315 -- clause within said level is used then reset the Current_Use_Clause
9316 -- to a redundant use clause outside of the current ending scope if such
9319 ---------------------------
9320 -- Update_Chain_In_Scope --
9321 ---------------------------
9323 procedure Update_Chain_In_Scope (Level : Int) is
9328 -- Loop through all use clauses within the scope dictated by Level
9330 Curr := Scope_Stack.Table (Level).First_Use_Clause;
9331 while Present (Curr) loop
9333 -- Retrieve the subtype mark or name within the current current
9336 if Nkind (Curr) = N_Use_Type_Clause then
9337 N := Subtype_Mark (Curr);
9342 -- If warnings for unreferenced entities are enabled and the
9343 -- current use clause has not been marked effective.
9345 if Check_Unreferenced
9346 and then Comes_From_Source (Curr)
9347 and then not Is_Effective_Use_Clause (Curr)
9348 and then not In_Instance
9349 and then not In_Inlined_Body
9351 -- We are dealing with a potentially unused use_package_clause
9353 if Nkind (Curr) = N_Use_Package_Clause then
9355 -- Renamings and formal subprograms may cause the associated
9356 -- node to be marked as effective instead of the original.
9358 if not (Present (Associated_Node (N))
9361 (Associated_Node (N)))
9362 and then Is_Effective_Use_Clause
9364 (Associated_Node (N))))
9366 Error_Msg_Node_1 := Entity (N);
9368 ("use clause for package & has no effect?u?",
9372 -- We are dealing with an unused use_type_clause
9375 Error_Msg_Node_1 := Etype (N);
9377 ("use clause for } has no effect?u?", Curr, Etype (N));
9381 -- Verify that we haven't already processed a redundant
9382 -- use_type_clause within the same scope before we move the
9383 -- current use clause up to a previous one for type T.
9385 if Present (Prev_Use_Clause (Curr)) then
9386 Set_Current_Use_Clause (Entity (N), Prev_Use_Clause (Curr));
9389 Next_Use_Clause (Curr);
9391 end Update_Chain_In_Scope;
9393 -- Start of processing for Update_Use_Clause_Chain
9396 Update_Chain_In_Scope (Scope_Stack.Last);
9398 -- Deal with use clauses within the context area if the current
9399 -- scope is a compilation unit.
9401 if Is_Compilation_Unit (Current_Scope)
9402 and then Sloc (Scope_Stack.Table
9403 (Scope_Stack.Last - 1).Entity) = Standard_Location
9405 Update_Chain_In_Scope (Scope_Stack.Last - 1);
9407 end Update_Use_Clause_Chain;
9409 ---------------------
9410 -- Use_One_Package --
9411 ---------------------
9413 procedure Use_One_Package
9415 Pack_Name : Entity_Id := Empty;
9416 Force : Boolean := False)
9418 procedure Note_Redundant_Use (Clause : Node_Id);
9419 -- Mark the name in a use clause as redundant if the corresponding
9420 -- entity is already use-visible. Emit a warning if the use clause comes
9421 -- from source and the proper warnings are enabled.
9423 ------------------------
9424 -- Note_Redundant_Use --
9425 ------------------------
9427 procedure Note_Redundant_Use (Clause : Node_Id) is
9428 Decl : constant Node_Id := Parent (Clause);
9429 Pack_Name : constant Entity_Id := Entity (Clause);
9431 Cur_Use : Node_Id := Current_Use_Clause (Pack_Name);
9432 Prev_Use : Node_Id := Empty;
9433 Redundant : Node_Id := Empty;
9434 -- The Use_Clause which is actually redundant. In the simplest case
9435 -- it is Pack itself, but when we compile a body we install its
9436 -- context before that of its spec, in which case it is the
9437 -- use_clause in the spec that will appear to be redundant, and we
9438 -- want the warning to be placed on the body. Similar complications
9439 -- appear when the redundancy is between a child unit and one of its
9443 -- Could be renamed...
9445 if No (Cur_Use) then
9446 Cur_Use := Current_Use_Clause (Renamed_Entity (Pack_Name));
9449 Set_Redundant_Use (Clause, True);
9451 if not Comes_From_Source (Clause)
9453 or else not Warn_On_Redundant_Constructs
9458 if not Is_Compilation_Unit (Current_Scope) then
9460 -- If the use_clause is in an inner scope, it is made redundant by
9461 -- some clause in the current context, with one exception: If we
9462 -- are compiling a nested package body, and the use_clause comes
9463 -- from then corresponding spec, the clause is not necessarily
9464 -- fully redundant, so we should not warn. If a warning was
9465 -- warranted, it would have been given when the spec was
9468 if Nkind (Parent (Decl)) = N_Package_Specification then
9470 Package_Spec_Entity : constant Entity_Id :=
9471 Defining_Unit_Name (Parent (Decl));
9473 if In_Package_Body (Package_Spec_Entity) then
9479 Redundant := Clause;
9480 Prev_Use := Cur_Use;
9482 elsif Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Body then
9484 Cur_Unit : constant Unit_Number_Type :=
9485 Get_Source_Unit (Cur_Use);
9486 New_Unit : constant Unit_Number_Type :=
9487 Get_Source_Unit (Clause);
9492 if Cur_Unit = New_Unit then
9494 -- Redundant clause in same body
9496 Redundant := Clause;
9497 Prev_Use := Cur_Use;
9499 elsif Cur_Unit = Current_Sem_Unit then
9501 -- If the new clause is not in the current unit it has been
9502 -- analyzed first, and it makes the other one redundant.
9503 -- However, if the new clause appears in a subunit, Cur_Unit
9504 -- is still the parent, and in that case the redundant one
9505 -- is the one appearing in the subunit.
9507 if Nkind (Unit (Cunit (New_Unit))) = N_Subunit then
9508 Redundant := Clause;
9509 Prev_Use := Cur_Use;
9511 -- Most common case: redundant clause in body, original
9512 -- clause in spec. Current scope is spec entity.
9514 elsif Current_Scope = Cunit_Entity (Current_Sem_Unit) then
9515 Redundant := Cur_Use;
9519 -- The new clause may appear in an unrelated unit, when
9520 -- the parents of a generic are being installed prior to
9521 -- instantiation. In this case there must be no warning.
9522 -- We detect this case by checking whether the current
9523 -- top of the stack is related to the current
9526 Scop := Current_Scope;
9527 while Present (Scop)
9528 and then Scop /= Standard_Standard
9530 if Is_Compilation_Unit (Scop)
9531 and then not Is_Child_Unit (Scop)
9535 elsif Scop = Cunit_Entity (Current_Sem_Unit) then
9539 Scop := Scope (Scop);
9542 Redundant := Cur_Use;
9546 elsif New_Unit = Current_Sem_Unit then
9547 Redundant := Clause;
9548 Prev_Use := Cur_Use;
9551 -- Neither is the current unit, so they appear in parent or
9552 -- sibling units. Warning will be emitted elsewhere.
9558 elsif Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Declaration
9559 and then Present (Parent_Spec (Unit (Cunit (Current_Sem_Unit))))
9561 -- Use_clause is in child unit of current unit, and the child unit
9562 -- appears in the context of the body of the parent, so it has
9563 -- been installed first, even though it is the redundant one.
9564 -- Depending on their placement in the context, the visible or the
9565 -- private parts of the two units, either might appear as
9566 -- redundant, but the message has to be on the current unit.
9568 if Get_Source_Unit (Cur_Use) = Current_Sem_Unit then
9569 Redundant := Cur_Use;
9572 Redundant := Clause;
9573 Prev_Use := Cur_Use;
9576 -- If the new use clause appears in the private part of a parent
9577 -- unit it may appear to be redundant w.r.t. a use clause in a
9578 -- child unit, but the previous use clause was needed in the
9579 -- visible part of the child, and no warning should be emitted.
9581 if Nkind (Parent (Decl)) = N_Package_Specification
9582 and then List_Containing (Decl) =
9583 Private_Declarations (Parent (Decl))
9586 Par : constant Entity_Id := Defining_Entity (Parent (Decl));
9587 Spec : constant Node_Id :=
9588 Specification (Unit (Cunit (Current_Sem_Unit)));
9589 Cur_List : constant List_Id := List_Containing (Cur_Use);
9591 if Is_Compilation_Unit (Par)
9592 and then Par /= Cunit_Entity (Current_Sem_Unit)
9594 if Cur_List = Context_Items (Cunit (Current_Sem_Unit))
9595 or else Cur_List = Visible_Declarations (Spec)
9603 -- Finally, if the current use clause is in the context then the
9604 -- clause is redundant when it is nested within the unit.
9606 elsif Nkind (Parent (Cur_Use)) = N_Compilation_Unit
9607 and then Nkind (Parent (Parent (Clause))) /= N_Compilation_Unit
9608 and then Get_Source_Unit (Cur_Use) = Get_Source_Unit (Clause)
9610 Redundant := Clause;
9611 Prev_Use := Cur_Use;
9614 if Present (Redundant) and then Parent (Redundant) /= Prev_Use then
9616 -- Make sure we are looking at most-descendant use_package_clause
9617 -- by traversing the chain with Find_Most_Prev and then verifying
9618 -- there is no scope manipulation via Most_Descendant_Use_Clause.
9620 if Nkind (Prev_Use) = N_Use_Package_Clause
9622 (Nkind (Parent (Prev_Use)) /= N_Compilation_Unit
9623 or else Most_Descendant_Use_Clause
9624 (Prev_Use, Find_Most_Prev (Prev_Use)) /= Prev_Use)
9626 Prev_Use := Find_Most_Prev (Prev_Use);
9629 Error_Msg_Sloc := Sloc (Prev_Use);
9630 Error_Msg_NE -- CODEFIX
9631 ("& is already use-visible through previous use_clause #??",
9632 Redundant, Pack_Name);
9634 end Note_Redundant_Use;
9638 Current_Instance : Entity_Id := Empty;
9642 Private_With_OK : Boolean := False;
9645 -- Start of processing for Use_One_Package
9648 -- Use_One_Package may have been called recursively to handle an
9649 -- implicit use for a auxiliary system package, so set P accordingly
9650 -- and skip redundancy checks.
9652 if No (Pack_Name) and then Present_System_Aux (N) then
9655 -- Check for redundant use_package_clauses
9658 -- Ignore cases where we are dealing with a non user defined package
9659 -- like Standard_Standard or something other than a valid package.
9661 if not Is_Entity_Name (Pack_Name)
9662 or else No (Entity (Pack_Name))
9663 or else Ekind (Entity (Pack_Name)) /= E_Package
9668 -- When a renaming exists we must check it for redundancy. The
9669 -- original package would have already been seen at this point.
9671 if Present (Renamed_Object (Entity (Pack_Name))) then
9672 P := Renamed_Object (Entity (Pack_Name));
9674 P := Entity (Pack_Name);
9677 -- Check for redundant clauses then set the current use clause for
9678 -- P if were are not "forcing" an installation from a scope
9679 -- reinstallation that is done throughout analysis for various
9683 Note_Redundant_Use (Pack_Name);
9686 Set_Current_Use_Clause (P, N);
9691 -- Warn about detected redundant clauses
9694 and then In_Open_Scopes (P)
9695 and then not Is_Hidden_Open_Scope (P)
9697 if Warn_On_Redundant_Constructs and then P = Current_Scope then
9698 Error_Msg_NE -- CODEFIX
9699 ("& is already use-visible within itself?r?",
9706 -- Set P back to the non-renamed package so that visiblilty of the
9707 -- entities within the package can be properly set below.
9709 P := Entity (Pack_Name);
9713 Set_Current_Use_Clause (P, N);
9715 -- Ada 2005 (AI-50217): Check restriction
9717 if From_Limited_With (P) then
9718 Error_Msg_N ("limited withed package cannot appear in use clause", N);
9721 -- Find enclosing instance, if any
9724 Current_Instance := Current_Scope;
9725 while not Is_Generic_Instance (Current_Instance) loop
9726 Current_Instance := Scope (Current_Instance);
9729 if No (Hidden_By_Use_Clause (N)) then
9730 Set_Hidden_By_Use_Clause (N, New_Elmt_List);
9734 -- If unit is a package renaming, indicate that the renamed package is
9735 -- also in use (the flags on both entities must remain consistent, and a
9736 -- subsequent use of either of them should be recognized as redundant).
9738 if Present (Renamed_Object (P)) then
9739 Set_In_Use (Renamed_Object (P));
9740 Set_Current_Use_Clause (Renamed_Object (P), N);
9741 Real_P := Renamed_Object (P);
9746 -- Ada 2005 (AI-262): Check the use_clause of a private withed package
9747 -- found in the private part of a package specification
9749 if In_Private_Part (Current_Scope)
9750 and then Has_Private_With (P)
9751 and then Is_Child_Unit (Current_Scope)
9752 and then Is_Child_Unit (P)
9753 and then Is_Ancestor_Package (Scope (Current_Scope), P)
9755 Private_With_OK := True;
9758 -- Loop through entities in one package making them potentially
9761 Id := First_Entity (P);
9763 and then (Id /= First_Private_Entity (P)
9764 or else Private_With_OK) -- Ada 2005 (AI-262)
9766 Prev := Current_Entity (Id);
9767 while Present (Prev) loop
9768 if Is_Immediately_Visible (Prev)
9769 and then (not Is_Overloadable (Prev)
9770 or else not Is_Overloadable (Id)
9771 or else (Type_Conformant (Id, Prev)))
9773 if No (Current_Instance) then
9775 -- Potentially use-visible entity remains hidden
9777 goto Next_Usable_Entity;
9779 -- A use clause within an instance hides outer global entities,
9780 -- which are not used to resolve local entities in the
9781 -- instance. Note that the predefined entities in Standard
9782 -- could not have been hidden in the generic by a use clause,
9783 -- and therefore remain visible. Other compilation units whose
9784 -- entities appear in Standard must be hidden in an instance.
9786 -- To determine whether an entity is external to the instance
9787 -- we compare the scope depth of its scope with that of the
9788 -- current instance. However, a generic actual of a subprogram
9789 -- instance is declared in the wrapper package but will not be
9790 -- hidden by a use-visible entity. similarly, an entity that is
9791 -- declared in an enclosing instance will not be hidden by an
9792 -- an entity declared in a generic actual, which can only have
9793 -- been use-visible in the generic and will not have hidden the
9794 -- entity in the generic parent.
9796 -- If Id is called Standard, the predefined package with the
9797 -- same name is in the homonym chain. It has to be ignored
9798 -- because it has no defined scope (being the only entity in
9799 -- the system with this mandated behavior).
9801 elsif not Is_Hidden (Id)
9802 and then Present (Scope (Prev))
9803 and then not Is_Wrapper_Package (Scope (Prev))
9804 and then Scope_Depth (Scope (Prev)) <
9805 Scope_Depth (Current_Instance)
9806 and then (Scope (Prev) /= Standard_Standard
9807 or else Sloc (Prev) > Standard_Location)
9809 if In_Open_Scopes (Scope (Prev))
9810 and then Is_Generic_Instance (Scope (Prev))
9811 and then Present (Associated_Formal_Package (P))
9816 Set_Is_Potentially_Use_Visible (Id);
9817 Set_Is_Immediately_Visible (Prev, False);
9818 Append_Elmt (Prev, Hidden_By_Use_Clause (N));
9822 -- A user-defined operator is not use-visible if the predefined
9823 -- operator for the type is immediately visible, which is the case
9824 -- if the type of the operand is in an open scope. This does not
9825 -- apply to user-defined operators that have operands of different
9826 -- types, because the predefined mixed mode operations (multiply
9827 -- and divide) apply to universal types and do not hide anything.
9829 elsif Ekind (Prev) = E_Operator
9830 and then Operator_Matches_Spec (Prev, Id)
9831 and then In_Open_Scopes
9832 (Scope (Base_Type (Etype (First_Formal (Id)))))
9833 and then (No (Next_Formal (First_Formal (Id)))
9834 or else Etype (First_Formal (Id)) =
9835 Etype (Next_Formal (First_Formal (Id)))
9836 or else Chars (Prev) = Name_Op_Expon)
9838 goto Next_Usable_Entity;
9840 -- In an instance, two homonyms may become use_visible through the
9841 -- actuals of distinct formal packages. In the generic, only the
9842 -- current one would have been visible, so make the other one
9845 -- In certain pathological cases it is possible that unrelated
9846 -- homonyms from distinct formal packages may exist in an
9847 -- uninstalled scope. We must test for that here.
9849 elsif Present (Current_Instance)
9850 and then Is_Potentially_Use_Visible (Prev)
9851 and then not Is_Overloadable (Prev)
9852 and then Scope (Id) /= Scope (Prev)
9853 and then Used_As_Generic_Actual (Scope (Prev))
9854 and then Used_As_Generic_Actual (Scope (Id))
9855 and then Is_List_Member (Scope (Prev))
9856 and then not In_Same_List (Current_Use_Clause (Scope (Prev)),
9857 Current_Use_Clause (Scope (Id)))
9859 Set_Is_Potentially_Use_Visible (Prev, False);
9860 Append_Elmt (Prev, Hidden_By_Use_Clause (N));
9863 Prev := Homonym (Prev);
9866 -- On exit, we know entity is not hidden, unless it is private
9868 if not Is_Hidden (Id)
9869 and then ((not Is_Child_Unit (Id)) or else Is_Visible_Lib_Unit (Id))
9871 Set_Is_Potentially_Use_Visible (Id);
9873 if Is_Private_Type (Id) and then Present (Full_View (Id)) then
9874 Set_Is_Potentially_Use_Visible (Full_View (Id));
9878 <<Next_Usable_Entity>>
9882 -- Child units are also made use-visible by a use clause, but they may
9883 -- appear after all visible declarations in the parent entity list.
9885 while Present (Id) loop
9886 if Is_Child_Unit (Id) and then Is_Visible_Lib_Unit (Id) then
9887 Set_Is_Potentially_Use_Visible (Id);
9893 if Chars (Real_P) = Name_System
9894 and then Scope (Real_P) = Standard_Standard
9895 and then Present_System_Aux (N)
9897 Use_One_Package (N);
9899 end Use_One_Package;
9905 procedure Use_One_Type
9907 Installed : Boolean := False;
9908 Force : Boolean := False)
9910 function Spec_Reloaded_For_Body return Boolean;
9911 -- Determine whether the compilation unit is a package body and the use
9912 -- type clause is in the spec of the same package. Even though the spec
9913 -- was analyzed first, its context is reloaded when analysing the body.
9915 procedure Use_Class_Wide_Operations (Typ : Entity_Id);
9916 -- AI05-150: if the use_type_clause carries the "all" qualifier,
9917 -- class-wide operations of ancestor types are use-visible if the
9918 -- ancestor type is visible.
9920 ----------------------------
9921 -- Spec_Reloaded_For_Body --
9922 ----------------------------
9924 function Spec_Reloaded_For_Body return Boolean is
9926 if Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Body then
9928 Spec : constant Node_Id :=
9929 Parent (List_Containing (Parent (Id)));
9932 -- Check whether type is declared in a package specification,
9933 -- and current unit is the corresponding package body. The
9934 -- use clauses themselves may be within a nested package.
9937 Nkind (Spec) = N_Package_Specification
9938 and then In_Same_Source_Unit
9939 (Corresponding_Body (Parent (Spec)),
9940 Cunit_Entity (Current_Sem_Unit));
9945 end Spec_Reloaded_For_Body;
9947 -------------------------------
9948 -- Use_Class_Wide_Operations --
9949 -------------------------------
9951 procedure Use_Class_Wide_Operations (Typ : Entity_Id) is
9952 function Is_Class_Wide_Operation_Of
9954 T : Entity_Id) return Boolean;
9955 -- Determine whether a subprogram has a class-wide parameter or
9956 -- result that is T'Class.
9958 ---------------------------------
9959 -- Is_Class_Wide_Operation_Of --
9960 ---------------------------------
9962 function Is_Class_Wide_Operation_Of
9964 T : Entity_Id) return Boolean
9969 Formal := First_Formal (Op);
9970 while Present (Formal) loop
9971 if Etype (Formal) = Class_Wide_Type (T) then
9975 Next_Formal (Formal);
9978 if Etype (Op) = Class_Wide_Type (T) then
9983 end Is_Class_Wide_Operation_Of;
9990 -- Start of processing for Use_Class_Wide_Operations
9993 Scop := Scope (Typ);
9994 if not Is_Hidden (Scop) then
9995 Ent := First_Entity (Scop);
9996 while Present (Ent) loop
9997 if Is_Overloadable (Ent)
9998 and then Is_Class_Wide_Operation_Of (Ent, Typ)
9999 and then not Is_Potentially_Use_Visible (Ent)
10001 Set_Is_Potentially_Use_Visible (Ent);
10002 Append_Elmt (Ent, Used_Operations (Parent (Id)));
10009 if Is_Derived_Type (Typ) then
10010 Use_Class_Wide_Operations (Etype (Base_Type (Typ)));
10012 end Use_Class_Wide_Operations;
10017 Is_Known_Used : Boolean;
10018 Op_List : Elist_Id;
10021 -- Start of processing for Use_One_Type
10024 if Entity (Id) = Any_Type then
10028 -- It is the type determined by the subtype mark (8.4(8)) whose
10029 -- operations become potentially use-visible.
10031 T := Base_Type (Entity (Id));
10033 -- Either the type itself is used, the package where it is declared is
10034 -- in use or the entity is declared in the current package, thus
10039 and then ((Present (Current_Use_Clause (T))
10040 and then All_Present (Current_Use_Clause (T)))
10041 or else not All_Present (Parent (Id))))
10042 or else In_Use (Scope (T))
10043 or else Scope (T) = Current_Scope;
10045 Set_Redundant_Use (Id,
10046 Is_Known_Used or else Is_Potentially_Use_Visible (T));
10048 if Ekind (T) = E_Incomplete_Type then
10049 Error_Msg_N ("premature usage of incomplete type", Id);
10051 elsif In_Open_Scopes (Scope (T)) then
10054 -- A limited view cannot appear in a use_type_clause. However, an access
10055 -- type whose designated type is limited has the flag but is not itself
10056 -- a limited view unless we only have a limited view of its enclosing
10059 elsif From_Limited_With (T) and then From_Limited_With (Scope (T)) then
10061 ("incomplete type from limited view cannot appear in use clause",
10064 -- If the use clause is redundant, Used_Operations will usually be
10065 -- empty, but we need to set it to empty here in one case: If we are
10066 -- instantiating a generic library unit, then we install the ancestors
10067 -- of that unit in the scope stack, which involves reprocessing use
10068 -- clauses in those ancestors. Such a use clause will typically have a
10069 -- nonempty Used_Operations unless it was redundant in the generic unit,
10070 -- even if it is redundant at the place of the instantiation.
10072 elsif Redundant_Use (Id) then
10074 -- We must avoid incorrectly setting the Current_Use_Clause when we
10075 -- are working with a redundant clause that has already been linked
10076 -- in the Prev_Use_Clause chain, otherwise the chain will break.
10078 if Present (Current_Use_Clause (T))
10079 and then Present (Prev_Use_Clause (Current_Use_Clause (T)))
10080 and then Parent (Id) = Prev_Use_Clause (Current_Use_Clause (T))
10084 Set_Current_Use_Clause (T, Parent (Id));
10087 Set_Used_Operations (Parent (Id), New_Elmt_List);
10089 -- If the subtype mark designates a subtype in a different package,
10090 -- we have to check that the parent type is visible, otherwise the
10091 -- use_type_clause is a no-op. Not clear how to do that???
10094 Set_Current_Use_Clause (T, Parent (Id));
10097 -- If T is tagged, primitive operators on class-wide operands are
10098 -- also deemed available. Note that this is really necessary only
10099 -- in semantics-only mode, because the primitive operators are not
10100 -- fully constructed in this mode, but we do it in all modes for the
10101 -- sake of uniformity, as this should not matter in practice.
10103 if Is_Tagged_Type (T) then
10104 Set_In_Use (Class_Wide_Type (T));
10107 -- Iterate over primitive operations of the type. If an operation is
10108 -- already use_visible, it is the result of a previous use_clause,
10109 -- and already appears on the corresponding entity chain. If the
10110 -- clause is being reinstalled, operations are already use-visible.
10116 Op_List := Collect_Primitive_Operations (T);
10117 Elmt := First_Elmt (Op_List);
10118 while Present (Elmt) loop
10119 if (Nkind (Node (Elmt)) = N_Defining_Operator_Symbol
10120 or else Chars (Node (Elmt)) in Any_Operator_Name)
10121 and then not Is_Hidden (Node (Elmt))
10122 and then not Is_Potentially_Use_Visible (Node (Elmt))
10124 Set_Is_Potentially_Use_Visible (Node (Elmt));
10125 Append_Elmt (Node (Elmt), Used_Operations (Parent (Id)));
10127 elsif Ada_Version >= Ada_2012
10128 and then All_Present (Parent (Id))
10129 and then not Is_Hidden (Node (Elmt))
10130 and then not Is_Potentially_Use_Visible (Node (Elmt))
10132 Set_Is_Potentially_Use_Visible (Node (Elmt));
10133 Append_Elmt (Node (Elmt), Used_Operations (Parent (Id)));
10140 if Ada_Version >= Ada_2012
10141 and then All_Present (Parent (Id))
10142 and then Is_Tagged_Type (T)
10144 Use_Class_Wide_Operations (T);
10148 -- If warning on redundant constructs, check for unnecessary WITH
10151 and then Warn_On_Redundant_Constructs
10152 and then Is_Known_Used
10154 -- with P; with P; use P;
10155 -- package P is package X is package body X is
10156 -- type T ... use P.T;
10158 -- The compilation unit is the body of X. GNAT first compiles the
10159 -- spec of X, then proceeds to the body. At that point P is marked
10160 -- as use visible. The analysis then reinstalls the spec along with
10161 -- its context. The use clause P.T is now recognized as redundant,
10162 -- but in the wrong context. Do not emit a warning in such cases.
10163 -- Do not emit a warning either if we are in an instance, there is
10164 -- no redundancy between an outer use_clause and one that appears
10165 -- within the generic.
10167 and then not Spec_Reloaded_For_Body
10168 and then not In_Instance
10169 and then not In_Inlined_Body
10171 -- The type already has a use clause
10175 -- Case where we know the current use clause for the type
10177 if Present (Current_Use_Clause (T)) then
10178 Use_Clause_Known : declare
10179 Clause1 : constant Node_Id :=
10180 Find_Most_Prev (Current_Use_Clause (T));
10181 Clause2 : constant Node_Id := Parent (Id);
10188 -- Start of processing for Use_Clause_Known
10191 -- If both current use_type_clause and the use_type_clause
10192 -- for the type are at the compilation unit level, one of
10193 -- the units must be an ancestor of the other, and the
10194 -- warning belongs on the descendant.
10196 if Nkind (Parent (Clause1)) = N_Compilation_Unit
10198 Nkind (Parent (Clause2)) = N_Compilation_Unit
10200 -- If the unit is a subprogram body that acts as spec,
10201 -- the context clause is shared with the constructed
10202 -- subprogram spec. Clearly there is no redundancy.
10204 if Clause1 = Clause2 then
10208 Unit1 := Unit (Parent (Clause1));
10209 Unit2 := Unit (Parent (Clause2));
10211 -- If both clauses are on same unit, or one is the body
10212 -- of the other, or one of them is in a subunit, report
10213 -- redundancy on the later one.
10215 if Unit1 = Unit2 or else Nkind (Unit1) = N_Subunit then
10216 Error_Msg_Sloc := Sloc (Current_Use_Clause (T));
10217 Error_Msg_NE -- CODEFIX
10218 ("& is already use-visible through previous "
10219 & "use_type_clause #??", Clause1, T);
10222 elsif Nkind_In (Unit2, N_Package_Body, N_Subprogram_Body)
10223 and then Nkind (Unit1) /= Nkind (Unit2)
10224 and then Nkind (Unit1) /= N_Subunit
10226 Error_Msg_Sloc := Sloc (Clause1);
10227 Error_Msg_NE -- CODEFIX
10228 ("& is already use-visible through previous "
10229 & "use_type_clause #??", Current_Use_Clause (T), T);
10233 -- There is a redundant use_type_clause in a child unit.
10234 -- Determine which of the units is more deeply nested.
10235 -- If a unit is a package instance, retrieve the entity
10236 -- and its scope from the instance spec.
10238 Ent1 := Entity_Of_Unit (Unit1);
10239 Ent2 := Entity_Of_Unit (Unit2);
10241 if Scope (Ent2) = Standard_Standard then
10242 Error_Msg_Sloc := Sloc (Current_Use_Clause (T));
10245 elsif Scope (Ent1) = Standard_Standard then
10246 Error_Msg_Sloc := Sloc (Id);
10249 -- If both units are child units, we determine which one
10250 -- is the descendant by the scope distance to the
10251 -- ultimate parent unit.
10259 S1 := Scope (Ent1);
10260 S2 := Scope (Ent2);
10262 and then Present (S2)
10263 and then S1 /= Standard_Standard
10264 and then S2 /= Standard_Standard
10270 if S1 = Standard_Standard then
10271 Error_Msg_Sloc := Sloc (Id);
10274 Error_Msg_Sloc := Sloc (Current_Use_Clause (T));
10280 if Parent (Id) /= Err_No then
10281 if Most_Descendant_Use_Clause
10282 (Err_No, Parent (Id)) = Parent (Id)
10284 Error_Msg_Sloc := Sloc (Err_No);
10285 Err_No := Parent (Id);
10288 Error_Msg_NE -- CODEFIX
10289 ("& is already use-visible through previous "
10290 & "use_type_clause #??", Err_No, Id);
10293 -- Case where current use_type_clause and use_type_clause
10294 -- for the type are not both at the compilation unit level.
10295 -- In this case we don't have location information.
10298 Error_Msg_NE -- CODEFIX
10299 ("& is already use-visible through previous "
10300 & "use_type_clause??", Id, T);
10302 end Use_Clause_Known;
10304 -- Here if Current_Use_Clause is not set for T, another case where
10305 -- we do not have the location information available.
10308 Error_Msg_NE -- CODEFIX
10309 ("& is already use-visible through previous "
10310 & "use_type_clause??", Id, T);
10313 -- The package where T is declared is already used
10315 elsif In_Use (Scope (T)) then
10316 -- Due to expansion of contracts we could be attempting to issue
10317 -- a spurious warning - so verify there is a previous use clause.
10319 if Current_Use_Clause (Scope (T)) /=
10320 Find_Most_Prev (Current_Use_Clause (Scope (T)))
10323 Sloc (Find_Most_Prev (Current_Use_Clause (Scope (T))));
10324 Error_Msg_NE -- CODEFIX
10325 ("& is already use-visible through package use clause #??",
10329 -- The current scope is the package where T is declared
10332 Error_Msg_Node_2 := Scope (T);
10333 Error_Msg_NE -- CODEFIX
10334 ("& is already use-visible inside package &??", Id, T);
10343 procedure Write_Info is
10344 Id : Entity_Id := First_Entity (Current_Scope);
10347 -- No point in dumping standard entities
10349 if Current_Scope = Standard_Standard then
10353 Write_Str ("========================================================");
10355 Write_Str (" Defined Entities in ");
10356 Write_Name (Chars (Current_Scope));
10358 Write_Str ("========================================================");
10362 Write_Str ("-- none --");
10366 while Present (Id) loop
10367 Write_Entity_Info (Id, " ");
10372 if Scope (Current_Scope) = Standard_Standard then
10374 -- Print information on the current unit itself
10376 Write_Entity_Info (Current_Scope, " ");
10389 for J in reverse 1 .. Scope_Stack.Last loop
10390 S := Scope_Stack.Table (J).Entity;
10391 Write_Int (Int (S));
10392 Write_Str (" === ");
10393 Write_Name (Chars (S));
10402 procedure we (S : Entity_Id) is
10405 E := First_Entity (S);
10406 while Present (E) loop
10407 Write_Int (Int (E));
10408 Write_Str (" === ");
10409 Write_Name (Chars (E));