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_Ch10; use Sem_Ch10;
56 with Sem_Ch12; use Sem_Ch12;
57 with Sem_Ch13; use Sem_Ch13;
58 with Sem_Dim; use Sem_Dim;
59 with Sem_Disp; use Sem_Disp;
60 with Sem_Dist; use Sem_Dist;
61 with Sem_Elab; use Sem_Elab;
62 with Sem_Eval; use Sem_Eval;
63 with Sem_Prag; use Sem_Prag;
64 with Sem_Res; use Sem_Res;
65 with Sem_Util; use Sem_Util;
66 with Sem_Type; use Sem_Type;
67 with Stand; use Stand;
68 with Sinfo; use Sinfo;
69 with Sinfo.CN; use Sinfo.CN;
70 with Snames; use Snames;
73 with Tbuild; use Tbuild;
74 with Uintp; use Uintp;
76 package body Sem_Ch8 is
78 ------------------------------------
79 -- Visibility and Name Resolution --
80 ------------------------------------
82 -- This package handles name resolution and the collection of possible
83 -- interpretations for overloaded names, prior to overload resolution.
85 -- Name resolution is the process that establishes a mapping between source
86 -- identifiers and the entities they denote at each point in the program.
87 -- Each entity is represented by a defining occurrence. Each identifier
88 -- that denotes an entity points to the corresponding defining occurrence.
89 -- This is the entity of the applied occurrence. Each occurrence holds
90 -- an index into the names table, where source identifiers are stored.
92 -- Each entry in the names table for an identifier or designator uses the
93 -- Info pointer to hold a link to the currently visible entity that has
94 -- this name (see subprograms Get_Name_Entity_Id and Set_Name_Entity_Id
95 -- in package Sem_Util). The visibility is initialized at the beginning of
96 -- semantic processing to make entities in package Standard immediately
97 -- visible. The visibility table is used in a more subtle way when
98 -- compiling subunits (see below).
100 -- Entities that have the same name (i.e. homonyms) are chained. In the
101 -- case of overloaded entities, this chain holds all the possible meanings
102 -- of a given identifier. The process of overload resolution uses type
103 -- information to select from this chain the unique meaning of a given
106 -- Entities are also chained in their scope, through the Next_Entity link.
107 -- As a consequence, the name space is organized as a sparse matrix, where
108 -- each row corresponds to a scope, and each column to a source identifier.
109 -- Open scopes, that is to say scopes currently being compiled, have their
110 -- corresponding rows of entities in order, innermost scope first.
112 -- The scopes of packages that are mentioned in context clauses appear in
113 -- no particular order, interspersed among open scopes. This is because
114 -- in the course of analyzing the context of a compilation, a package
115 -- declaration is first an open scope, and subsequently an element of the
116 -- context. If subunits or child units are present, a parent unit may
117 -- appear under various guises at various times in the compilation.
119 -- When the compilation of the innermost scope is complete, the entities
120 -- defined therein are no longer visible. If the scope is not a package
121 -- declaration, these entities are never visible subsequently, and can be
122 -- removed from visibility chains. If the scope is a package declaration,
123 -- its visible declarations may still be accessible. Therefore the entities
124 -- defined in such a scope are left on the visibility chains, and only
125 -- their visibility (immediately visibility or potential use-visibility)
128 -- The ordering of homonyms on their chain does not necessarily follow
129 -- the order of their corresponding scopes on the scope stack. For
130 -- example, if package P and the enclosing scope both contain entities
131 -- named E, then when compiling the package body the chain for E will
132 -- hold the global entity first, and the local one (corresponding to
133 -- the current inner scope) next. As a result, name resolution routines
134 -- do not assume any relative ordering of the homonym chains, either
135 -- for scope nesting or to order of appearance of context clauses.
137 -- When compiling a child unit, entities in the parent scope are always
138 -- immediately visible. When compiling the body of a child unit, private
139 -- entities in the parent must also be made immediately visible. There
140 -- are separate routines to make the visible and private declarations
141 -- visible at various times (see package Sem_Ch7).
143 -- +--------+ +-----+
144 -- | In use |-------->| EU1 |-------------------------->
145 -- +--------+ +-----+
147 -- +--------+ +-----+ +-----+
148 -- | Stand. |---------------->| ES1 |--------------->| ES2 |--->
149 -- +--------+ +-----+ +-----+
151 -- +---------+ | +-----+
152 -- | with'ed |------------------------------>| EW2 |--->
153 -- +---------+ | +-----+
155 -- +--------+ +-----+ +-----+
156 -- | Scope2 |---------------->| E12 |--------------->| E22 |--->
157 -- +--------+ +-----+ +-----+
159 -- +--------+ +-----+ +-----+
160 -- | Scope1 |---------------->| E11 |--------------->| E12 |--->
161 -- +--------+ +-----+ +-----+
165 -- | | with'ed |----------------------------------------->
169 -- (innermost first) | |
170 -- +----------------------------+
171 -- Names table => | Id1 | | | | Id2 |
172 -- +----------------------------+
174 -- Name resolution must deal with several syntactic forms: simple names,
175 -- qualified names, indexed names, and various forms of calls.
177 -- Each identifier points to an entry in the names table. The resolution
178 -- of a simple name consists in traversing the homonym chain, starting
179 -- from the names table. If an entry is immediately visible, it is the one
180 -- designated by the identifier. If only potentially use-visible entities
181 -- are on the chain, we must verify that they do not hide each other. If
182 -- the entity we find is overloadable, we collect all other overloadable
183 -- entities on the chain as long as they are not hidden.
185 -- To resolve expanded names, we must find the entity at the intersection
186 -- of the entity chain for the scope (the prefix) and the homonym chain
187 -- for the selector. In general, homonym chains will be much shorter than
188 -- entity chains, so it is preferable to start from the names table as
189 -- well. If the entity found is overloadable, we must collect all other
190 -- interpretations that are defined in the scope denoted by the prefix.
192 -- For records, protected types, and tasks, their local entities are
193 -- removed from visibility chains on exit from the corresponding scope.
194 -- From the outside, these entities are always accessed by selected
195 -- notation, and the entity chain for the record type, protected type,
196 -- etc. is traversed sequentially in order to find the designated entity.
198 -- The discriminants of a type and the operations of a protected type or
199 -- task are unchained on exit from the first view of the type, (such as
200 -- a private or incomplete type declaration, or a protected type speci-
201 -- fication) and re-chained when compiling the second view.
203 -- In the case of operators, we do not make operators on derived types
204 -- explicit. As a result, the notation P."+" may denote either a user-
205 -- defined function with name "+", or else an implicit declaration of the
206 -- operator "+" in package P. The resolution of expanded names always
207 -- tries to resolve an operator name as such an implicitly defined entity,
208 -- in addition to looking for explicit declarations.
210 -- All forms of names that denote entities (simple names, expanded names,
211 -- character literals in some cases) have a Entity attribute, which
212 -- identifies the entity denoted by the name.
214 ---------------------
215 -- The Scope Stack --
216 ---------------------
218 -- The Scope stack keeps track of the scopes currently been compiled.
219 -- Every entity that contains declarations (including records) is placed
220 -- on the scope stack while it is being processed, and removed at the end.
221 -- Whenever a non-package scope is exited, the entities defined therein
222 -- are removed from the visibility table, so that entities in outer scopes
223 -- become visible (see previous description). On entry to Sem, the scope
224 -- stack only contains the package Standard. As usual, subunits complicate
225 -- this picture ever so slightly.
227 -- The Rtsfind mechanism can force a call to Semantics while another
228 -- compilation is in progress. The unit retrieved by Rtsfind must be
229 -- compiled in its own context, and has no access to the visibility of
230 -- the unit currently being compiled. The procedures Save_Scope_Stack and
231 -- Restore_Scope_Stack make entities in current open scopes invisible
232 -- before compiling the retrieved unit, and restore the compilation
233 -- environment afterwards.
235 ------------------------
236 -- Compiling subunits --
237 ------------------------
239 -- Subunits must be compiled in the environment of the corresponding stub,
240 -- that is to say with the same visibility into the parent (and its
241 -- context) that is available at the point of the stub declaration, but
242 -- with the additional visibility provided by the context clause of the
243 -- subunit itself. As a result, compilation of a subunit forces compilation
244 -- of the parent (see description in lib-). At the point of the stub
245 -- declaration, Analyze is called recursively to compile the proper body of
246 -- the subunit, but without reinitializing the names table, nor the scope
247 -- stack (i.e. standard is not pushed on the stack). In this fashion the
248 -- context of the subunit is added to the context of the parent, and the
249 -- subunit is compiled in the correct environment. Note that in the course
250 -- of processing the context of a subunit, Standard will appear twice on
251 -- the scope stack: once for the parent of the subunit, and once for the
252 -- unit in the context clause being compiled. However, the two sets of
253 -- entities are not linked by homonym chains, so that the compilation of
254 -- any context unit happens in a fresh visibility environment.
256 -------------------------------
257 -- Processing of USE Clauses --
258 -------------------------------
260 -- Every defining occurrence has a flag indicating if it is potentially use
261 -- visible. Resolution of simple names examines this flag. The processing
262 -- of use clauses consists in setting this flag on all visible entities
263 -- defined in the corresponding package. On exit from the scope of the use
264 -- clause, the corresponding flag must be reset. However, a package may
265 -- appear in several nested use clauses (pathological but legal, alas)
266 -- which forces us to use a slightly more involved scheme:
268 -- a) The defining occurrence for a package holds a flag -In_Use- to
269 -- indicate that it is currently in the scope of a use clause. If a
270 -- redundant use clause is encountered, then the corresponding occurrence
271 -- of the package name is flagged -Redundant_Use-.
273 -- b) On exit from a scope, the use clauses in its declarative part are
274 -- scanned. The visibility flag is reset in all entities declared in
275 -- package named in a use clause, as long as the package is not flagged
276 -- as being in a redundant use clause (in which case the outer use
277 -- clause is still in effect, and the direct visibility of its entities
278 -- must be retained).
280 -- Note that entities are not removed from their homonym chains on exit
281 -- from the package specification. A subsequent use clause does not need
282 -- to rechain the visible entities, but only to establish their direct
285 -----------------------------------
286 -- Handling private declarations --
287 -----------------------------------
289 -- The principle that each entity has a single defining occurrence clashes
290 -- with the presence of two separate definitions for private types: the
291 -- first is the private type declaration, and second is the full type
292 -- declaration. It is important that all references to the type point to
293 -- the same defining occurrence, namely the first one. To enforce the two
294 -- separate views of the entity, the corresponding information is swapped
295 -- between the two declarations. Outside of the package, the defining
296 -- occurrence only contains the private declaration information, while in
297 -- the private part and the body of the package the defining occurrence
298 -- contains the full declaration. To simplify the swap, the defining
299 -- occurrence that currently holds the private declaration points to the
300 -- full declaration. During semantic processing the defining occurrence
301 -- also points to a list of private dependents, that is to say access types
302 -- or composite types whose designated types or component types are
303 -- subtypes or derived types of the private type in question. After the
304 -- full declaration has been seen, the private dependents are updated to
305 -- indicate that they have full definitions.
307 ------------------------------------
308 -- Handling of Undefined Messages --
309 ------------------------------------
311 -- In normal mode, only the first use of an undefined identifier generates
312 -- a message. The table Urefs is used to record error messages that have
313 -- been issued so that second and subsequent ones do not generate further
314 -- messages. However, the second reference causes text to be added to the
315 -- original undefined message noting "(more references follow)". The
316 -- full error list option (-gnatf) forces messages to be generated for
317 -- every reference and disconnects the use of this table.
319 type Uref_Entry is record
321 -- Node for identifier for which original message was posted. The
322 -- Chars field of this identifier is used to detect later references
323 -- to the same identifier.
326 -- Records error message Id of original undefined message. Reset to
327 -- No_Error_Msg after the second occurrence, where it is used to add
328 -- text to the original message as described above.
331 -- Set if the message is not visible rather than undefined
334 -- Records location of error message. Used to make sure that we do
335 -- not consider a, b : undefined as two separate instances, which
336 -- would otherwise happen, since the parser converts this sequence
337 -- to a : undefined; b : undefined.
341 package Urefs is new Table.Table (
342 Table_Component_Type => Uref_Entry,
343 Table_Index_Type => Nat,
344 Table_Low_Bound => 1,
346 Table_Increment => 100,
347 Table_Name => "Urefs");
349 Candidate_Renaming : Entity_Id;
350 -- Holds a candidate interpretation that appears in a subprogram renaming
351 -- declaration and does not match the given specification, but matches at
352 -- least on the first formal. Allows better error message when given
353 -- specification omits defaulted parameters, a common error.
355 -----------------------
356 -- Local Subprograms --
357 -----------------------
359 procedure Analyze_Generic_Renaming
362 -- Common processing for all three kinds of generic renaming declarations.
363 -- Enter new name and indicate that it renames the generic unit.
365 procedure Analyze_Renamed_Character
369 -- Renamed entity is given by a character literal, which must belong
370 -- to the return type of the new entity. Is_Body indicates whether the
371 -- declaration is a renaming_as_body. If the original declaration has
372 -- already been frozen (because of an intervening body, e.g.) the body of
373 -- the function must be built now. The same applies to the following
374 -- various renaming procedures.
376 procedure Analyze_Renamed_Dereference
380 -- Renamed entity is given by an explicit dereference. Prefix must be a
381 -- conformant access_to_subprogram type.
383 procedure Analyze_Renamed_Entry
387 -- If the renamed entity in a subprogram renaming is an entry or protected
388 -- subprogram, build a body for the new entity whose only statement is a
389 -- call to the renamed entity.
391 procedure Analyze_Renamed_Family_Member
395 -- Used when the renamed entity is an indexed component. The prefix must
396 -- denote an entry family.
398 procedure Analyze_Renamed_Primitive_Operation
402 -- If the renamed entity in a subprogram renaming is a primitive operation
403 -- or a class-wide operation in prefix form, save the target object,
404 -- which must be added to the list of actuals in any subsequent call.
405 -- The renaming operation is intrinsic because the compiler must in
406 -- fact generate a wrapper for it (6.3.1 (10 1/2)).
408 procedure Attribute_Renaming (N : Node_Id);
409 -- Analyze renaming of attribute as subprogram. The renaming declaration N
410 -- is rewritten as a subprogram body that returns the attribute reference
411 -- applied to the formals of the function.
413 procedure Set_Entity_Or_Discriminal (N : Node_Id; E : Entity_Id);
414 -- Set Entity, with style check if need be. For a discriminant reference,
415 -- replace by the corresponding discriminal, i.e. the parameter of the
416 -- initialization procedure that corresponds to the discriminant.
418 procedure Check_Frozen_Renaming (N : Node_Id; Subp : Entity_Id);
419 -- A renaming_as_body may occur after the entity of the original decla-
420 -- ration has been frozen. In that case, the body of the new entity must
421 -- be built now, because the usual mechanism of building the renamed
422 -- body at the point of freezing will not work. Subp is the subprogram
423 -- for which N provides the Renaming_As_Body.
425 procedure Check_In_Previous_With_Clause
428 -- N is a use_package clause and Nam the package name, or N is a use_type
429 -- clause and Nam is the prefix of the type name. In either case, verify
430 -- that the package is visible at that point in the context: either it
431 -- appears in a previous with_clause, or because it is a fully qualified
432 -- name and the root ancestor appears in a previous with_clause.
434 procedure Check_Library_Unit_Renaming (N : Node_Id; Old_E : Entity_Id);
435 -- Verify that the entity in a renaming declaration that is a library unit
436 -- is itself a library unit and not a nested unit or subunit. Also check
437 -- that if the renaming is a child unit of a generic parent, then the
438 -- renamed unit must also be a child unit of that parent. Finally, verify
439 -- that a renamed generic unit is not an implicit child declared within
440 -- an instance of the parent.
442 procedure Chain_Use_Clause (N : Node_Id);
443 -- Chain use clause onto list of uses clauses headed by First_Use_Clause in
444 -- the proper scope table entry. This is usually the current scope, but it
445 -- will be an inner scope when installing the use clauses of the private
446 -- declarations of a parent unit prior to compiling the private part of a
447 -- child unit. This chain is traversed when installing/removing use clauses
448 -- when compiling a subunit or instantiating a generic body on the fly,
449 -- when it is necessary to save and restore full environments.
451 function Enclosing_Instance return Entity_Id;
452 -- In an instance nested within another one, several semantic checks are
453 -- unnecessary because the legality of the nested instance has been checked
454 -- in the enclosing generic unit. This applies in particular to legality
455 -- checks on actuals for formal subprograms of the inner instance, which
456 -- are checked as subprogram renamings, and may be complicated by confusion
457 -- in private/full views. This function returns the instance enclosing the
458 -- current one if there is such, else it returns Empty.
460 -- If the renaming determines the entity for the default of a formal
461 -- subprogram nested within another instance, choose the innermost
462 -- candidate. This is because if the formal has a box, and we are within
463 -- an enclosing instance where some candidate interpretations are local
464 -- to this enclosing instance, we know that the default was properly
465 -- resolved when analyzing the generic, so we prefer the local
466 -- candidates to those that are external. This is not always the case
467 -- but is a reasonable heuristic on the use of nested generics. The
468 -- proper solution requires a full renaming model.
470 function Entity_Of_Unit (U : Node_Id) return Entity_Id;
471 -- Return the appropriate entity for determining which unit has a deeper
472 -- scope: the defining entity for U, unless U is a package instance, in
473 -- which case we retrieve the entity of the instance spec.
475 procedure Find_Expanded_Name (N : Node_Id);
476 -- The input is a selected component known to be an expanded name. Verify
477 -- legality of selector given the scope denoted by prefix, and change node
478 -- N into a expanded name with a properly set Entity field.
480 function Find_Most_Prev (Use_Clause : Node_Id) return Node_Id;
481 -- Find the most previous use clause (that is, the first one to appear in
482 -- the source) by traversing the previous clause chain that exists in both
483 -- N_Use_Package_Clause nodes and N_Use_Type_Clause nodes.
484 -- ??? a better subprogram name is in order
486 function Find_Renamed_Entity
490 Is_Actual : Boolean := False) return Entity_Id;
491 -- Find the renamed entity that corresponds to the given parameter profile
492 -- in a subprogram renaming declaration. The renamed entity may be an
493 -- operator, a subprogram, an entry, or a protected operation. Is_Actual
494 -- indicates that the renaming is the one generated for an actual subpro-
495 -- gram in an instance, for which special visibility checks apply.
497 function Has_Implicit_Character_Literal (N : Node_Id) return Boolean;
498 -- Find a type derived from Character or Wide_Character in the prefix of N.
499 -- Used to resolved qualified names whose selector is a character literal.
501 function Has_Private_With (E : Entity_Id) return Boolean;
502 -- Ada 2005 (AI-262): Determines if the current compilation unit has a
503 -- private with on E.
505 function Has_Components (Typ : Entity_Id) return Boolean;
506 -- Determine if given type has components, i.e. is either a record type or
507 -- type or a type that has discriminants.
509 function Has_Implicit_Operator (N : Node_Id) return Boolean;
510 -- N is an expanded name whose selector is an operator name (e.g. P."+").
511 -- declarative part contains an implicit declaration of an operator if it
512 -- has a declaration of a type to which one of the predefined operators
513 -- apply. The existence of this routine is an implementation artifact. A
514 -- more straightforward but more space-consuming choice would be to make
515 -- all inherited operators explicit in the symbol table.
517 procedure Inherit_Renamed_Profile (New_S : Entity_Id; Old_S : Entity_Id);
518 -- A subprogram defined by a renaming declaration inherits the parameter
519 -- profile of the renamed entity. The subtypes given in the subprogram
520 -- specification are discarded and replaced with those of the renamed
521 -- subprogram, which are then used to recheck the default values.
523 function Most_Descendant_Use_Clause
524 (Clause1 : Entity_Id;
525 Clause2 : Entity_Id) return Entity_Id;
526 -- Determine which use clause parameter is the most descendant in terms of
528 -- ??? a better subprogram name is in order
530 procedure Premature_Usage (N : Node_Id);
531 -- Diagnose usage of an entity before it is visible
533 procedure Use_One_Package
535 Pack_Name : Entity_Id := Empty;
536 Force : Boolean := False);
537 -- Make visible entities declared in package P potentially use-visible
538 -- in the current context. Also used in the analysis of subunits, when
539 -- re-installing use clauses of parent units. N is the use_clause that
540 -- names P (and possibly other packages).
542 procedure Use_One_Type
544 Installed : Boolean := False;
545 Force : Boolean := False);
546 -- Id is the subtype mark from a use_type_clause. This procedure makes
547 -- the primitive operators of the type potentially use-visible. The
548 -- boolean flag Installed indicates that the clause is being reinstalled
549 -- after previous analysis, and primitive operations are already chained
550 -- on the Used_Operations list of the clause.
552 procedure Write_Info;
553 -- Write debugging information on entities declared in current scope
555 --------------------------------
556 -- Analyze_Exception_Renaming --
557 --------------------------------
559 -- The language only allows a single identifier, but the tree holds an
560 -- identifier list. The parser has already issued an error message if
561 -- there is more than one element in the list.
563 procedure Analyze_Exception_Renaming (N : Node_Id) is
564 Id : constant Entity_Id := Defining_Entity (N);
565 Nam : constant Node_Id := Name (N);
571 Set_Ekind (Id, E_Exception);
572 Set_Etype (Id, Standard_Exception_Type);
573 Set_Is_Pure (Id, Is_Pure (Current_Scope));
575 if Is_Entity_Name (Nam)
576 and then Present (Entity (Nam))
577 and then Ekind (Entity (Nam)) = E_Exception
579 if Present (Renamed_Object (Entity (Nam))) then
580 Set_Renamed_Object (Id, Renamed_Object (Entity (Nam)));
582 Set_Renamed_Object (Id, Entity (Nam));
585 -- The exception renaming declaration may become Ghost if it renames
588 Mark_Ghost_Renaming (N, Entity (Nam));
590 Error_Msg_N ("invalid exception name in renaming", Nam);
593 -- Implementation-defined aspect specifications can appear in a renaming
594 -- declaration, but not language-defined ones. The call to procedure
595 -- Analyze_Aspect_Specifications will take care of this error check.
597 if Has_Aspects (N) then
598 Analyze_Aspect_Specifications (N, Id);
600 end Analyze_Exception_Renaming;
602 ---------------------------
603 -- Analyze_Expanded_Name --
604 ---------------------------
606 procedure Analyze_Expanded_Name (N : Node_Id) is
608 -- If the entity pointer is already set, this is an internal node, or a
609 -- node that is analyzed more than once, after a tree modification. In
610 -- such a case there is no resolution to perform, just set the type. In
611 -- either case, start by analyzing the prefix.
613 Analyze (Prefix (N));
615 if Present (Entity (N)) then
616 if Is_Type (Entity (N)) then
617 Set_Etype (N, Entity (N));
619 Set_Etype (N, Etype (Entity (N)));
623 Find_Expanded_Name (N);
626 -- In either case, propagate dimension of entity to expanded name
628 Analyze_Dimension (N);
629 end Analyze_Expanded_Name;
631 ---------------------------------------
632 -- Analyze_Generic_Function_Renaming --
633 ---------------------------------------
635 procedure Analyze_Generic_Function_Renaming (N : Node_Id) is
637 Analyze_Generic_Renaming (N, E_Generic_Function);
638 end Analyze_Generic_Function_Renaming;
640 --------------------------------------
641 -- Analyze_Generic_Package_Renaming --
642 --------------------------------------
644 procedure Analyze_Generic_Package_Renaming (N : Node_Id) is
646 -- Test for the Text_IO special unit case here, since we may be renaming
647 -- one of the subpackages of Text_IO, then join common routine.
649 Check_Text_IO_Special_Unit (Name (N));
651 Analyze_Generic_Renaming (N, E_Generic_Package);
652 end Analyze_Generic_Package_Renaming;
654 ----------------------------------------
655 -- Analyze_Generic_Procedure_Renaming --
656 ----------------------------------------
658 procedure Analyze_Generic_Procedure_Renaming (N : Node_Id) is
660 Analyze_Generic_Renaming (N, E_Generic_Procedure);
661 end Analyze_Generic_Procedure_Renaming;
663 ------------------------------
664 -- Analyze_Generic_Renaming --
665 ------------------------------
667 procedure Analyze_Generic_Renaming
671 New_P : constant Entity_Id := Defining_Entity (N);
672 Inst : Boolean := False;
676 if Name (N) = Error then
680 Generate_Definition (New_P);
682 if Current_Scope /= Standard_Standard then
683 Set_Is_Pure (New_P, Is_Pure (Current_Scope));
686 if Nkind (Name (N)) = N_Selected_Component then
687 Check_Generic_Child_Unit (Name (N), Inst);
692 if not Is_Entity_Name (Name (N)) then
693 Error_Msg_N ("expect entity name in renaming declaration", Name (N));
696 Old_P := Entity (Name (N));
700 Set_Ekind (New_P, K);
702 if Etype (Old_P) = Any_Type then
705 elsif Ekind (Old_P) /= K then
706 Error_Msg_N ("invalid generic unit name", Name (N));
709 if Present (Renamed_Object (Old_P)) then
710 Set_Renamed_Object (New_P, Renamed_Object (Old_P));
712 Set_Renamed_Object (New_P, Old_P);
715 -- The generic renaming declaration may become Ghost if it renames a
718 Mark_Ghost_Renaming (N, Old_P);
720 Set_Is_Pure (New_P, Is_Pure (Old_P));
721 Set_Is_Preelaborated (New_P, Is_Preelaborated (Old_P));
723 Set_Etype (New_P, Etype (Old_P));
724 Set_Has_Completion (New_P);
726 if In_Open_Scopes (Old_P) then
727 Error_Msg_N ("within its scope, generic denotes its instance", N);
730 -- For subprograms, propagate the Intrinsic flag, to allow, e.g.
731 -- renamings and subsequent instantiations of Unchecked_Conversion.
733 if Is_Generic_Subprogram (Old_P) then
734 Set_Is_Intrinsic_Subprogram
735 (New_P, Is_Intrinsic_Subprogram (Old_P));
738 Check_Library_Unit_Renaming (N, Old_P);
741 -- Implementation-defined aspect specifications can appear in a renaming
742 -- declaration, but not language-defined ones. The call to procedure
743 -- Analyze_Aspect_Specifications will take care of this error check.
745 if Has_Aspects (N) then
746 Analyze_Aspect_Specifications (N, New_P);
748 end Analyze_Generic_Renaming;
750 -----------------------------
751 -- Analyze_Object_Renaming --
752 -----------------------------
754 procedure Analyze_Object_Renaming (N : Node_Id) is
755 Id : constant Entity_Id := Defining_Identifier (N);
756 Loc : constant Source_Ptr := Sloc (N);
757 Nam : constant Node_Id := Name (N);
758 Is_Object_Ref : Boolean;
763 procedure Check_Constrained_Object;
764 -- If the nominal type is unconstrained but the renamed object is
765 -- constrained, as can happen with renaming an explicit dereference or
766 -- a function return, build a constrained subtype from the object. If
767 -- the renaming is for a formal in an accept statement, the analysis
768 -- has already established its actual subtype. This is only relevant
769 -- if the renamed object is an explicit dereference.
771 function Get_Object_Name (Nod : Node_Id) return Node_Id;
772 -- Obtain the name of the object from node Nod which is being renamed by
773 -- the object renaming declaration N.
775 function Find_Raise_Node (N : Node_Id) return Traverse_Result;
776 -- Process one node in search for N_Raise_xxx_Error nodes.
777 -- Return Abandon if found, OK otherwise.
779 ---------------------
780 -- Find_Raise_Node --
781 ---------------------
783 function Find_Raise_Node (N : Node_Id) return Traverse_Result is
785 if Nkind (N) in N_Raise_xxx_Error then
792 ------------------------
793 -- No_Raise_xxx_Error --
794 ------------------------
796 function No_Raise_xxx_Error is new Traverse_Func (Find_Raise_Node);
797 -- Traverse tree to look for a N_Raise_xxx_Error node and returns
798 -- Abandon if so and OK if none found.
800 ------------------------------
801 -- Check_Constrained_Object --
802 ------------------------------
804 procedure Check_Constrained_Object is
805 Typ : constant Entity_Id := Etype (Nam);
807 Loop_Scheme : Node_Id;
810 if Nkind (Nam) in N_Function_Call | N_Explicit_Dereference
811 and then Is_Composite_Type (Typ)
812 and then not Is_Constrained (Typ)
813 and then not Has_Unknown_Discriminants (Typ)
814 and then Expander_Active
816 -- If Actual_Subtype is already set, nothing to do
818 if Ekind (Id) in E_Variable | E_Constant
819 and then Present (Actual_Subtype (Id))
823 -- A renaming of an unchecked union has no actual subtype
825 elsif Is_Unchecked_Union (Typ) then
828 -- If a record is limited its size is invariant. This is the case
829 -- in particular with record types with an access discriminant
830 -- that are used in iterators. This is an optimization, but it
831 -- also prevents typing anomalies when the prefix is further
834 -- Note that we cannot just use the Is_Limited_Record flag because
835 -- it does not apply to records with limited components, for which
836 -- this syntactic flag is not set, but whose size is also fixed.
838 -- Note also that we need to build the constrained subtype for an
839 -- array in order to make the bounds explicit in most cases, but
840 -- not if the object comes from an extended return statement, as
841 -- this would create dangling references to them later on.
843 elsif Is_Limited_Type (Typ)
844 and then (not Is_Array_Type (Typ) or else Is_Return_Object (Id))
849 Subt := Make_Temporary (Loc, 'T');
850 Remove_Side_Effects (Nam);
852 Make_Subtype_Declaration (Loc,
853 Defining_Identifier => Subt,
854 Subtype_Indication =>
855 Make_Subtype_From_Expr (Nam, Typ)));
856 Rewrite (Subtype_Mark (N), New_Occurrence_Of (Subt, Loc));
857 Set_Etype (Nam, Subt);
859 -- Suppress discriminant checks on this subtype if the original
860 -- type has defaulted discriminants and Id is a "for of" loop
863 if Has_Defaulted_Discriminants (Typ)
864 and then Nkind (Original_Node (Parent (N))) = N_Loop_Statement
866 Loop_Scheme := Iteration_Scheme (Original_Node (Parent (N)));
868 if Present (Loop_Scheme)
869 and then Present (Iterator_Specification (Loop_Scheme))
872 (Iterator_Specification (Loop_Scheme)) = Id
874 Set_Checks_May_Be_Suppressed (Subt);
875 Push_Local_Suppress_Stack_Entry
877 Check => Discriminant_Check,
882 -- Freeze subtype at once, to prevent order of elaboration
883 -- issues in the backend. The renamed object exists, so its
884 -- type is already frozen in any case.
886 Freeze_Before (N, Subt);
889 end Check_Constrained_Object;
891 ---------------------
892 -- Get_Object_Name --
893 ---------------------
895 function Get_Object_Name (Nod : Node_Id) return Node_Id is
900 while Present (Obj_Nam) loop
901 case Nkind (Obj_Nam) is
902 when N_Attribute_Reference
903 | N_Explicit_Dereference
904 | N_Indexed_Component
907 Obj_Nam := Prefix (Obj_Nam);
909 when N_Selected_Component =>
910 Obj_Nam := Selector_Name (Obj_Nam);
912 when N_Qualified_Expression | N_Type_Conversion =>
913 Obj_Nam := Expression (Obj_Nam);
923 -- Start of processing for Analyze_Object_Renaming
930 Set_Is_Pure (Id, Is_Pure (Current_Scope));
933 -- The renaming of a component that depends on a discriminant requires
934 -- an actual subtype, because in subsequent use of the object Gigi will
935 -- be unable to locate the actual bounds. This explicit step is required
936 -- when the renaming is generated in removing side effects of an
937 -- already-analyzed expression.
939 if Nkind (Nam) = N_Selected_Component and then Analyzed (Nam) then
941 -- The object renaming declaration may become Ghost if it renames a
944 if Is_Entity_Name (Nam) then
945 Mark_Ghost_Renaming (N, Entity (Nam));
949 Dec := Build_Actual_Subtype_Of_Component (Etype (Nam), Nam);
951 if Present (Dec) then
952 Insert_Action (N, Dec);
953 T := Defining_Identifier (Dec);
956 elsif Present (Subtype_Mark (N))
957 or else not Present (Access_Definition (N))
959 if Present (Subtype_Mark (N)) then
960 Find_Type (Subtype_Mark (N));
961 T := Entity (Subtype_Mark (N));
964 -- AI12-0275: Case of object renaming without a subtype_mark
969 -- Normal case of no overloading in object name
971 if not Is_Overloaded (Nam) then
973 -- Catch error cases (such as attempting to rename a procedure
974 -- or package) using the shorthand form.
977 or else Etype (Nam) = Standard_Void_Type
980 ("object name or value expected in renaming", Nam);
982 Set_Ekind (Id, E_Variable);
983 Set_Etype (Id, Any_Type);
991 -- Case of overloaded name, which will be illegal if there's more
992 -- than one acceptable interpretation (such as overloaded function
1004 -- More than one candidate interpretation is available
1006 -- Remove procedure calls, which syntactically cannot appear
1007 -- in this context, but which cannot be removed by type
1008 -- checking, because the context does not impose a type.
1010 Get_First_Interp (Nam, I, It);
1011 while Present (It.Typ) loop
1012 if It.Typ = Standard_Void_Type then
1016 Get_Next_Interp (I, It);
1019 Get_First_Interp (Nam, I, It);
1023 -- If there's no type present, we have an error case (such
1024 -- as overloaded procedures named in the object renaming).
1028 ("object name or value expected in renaming", Nam);
1030 Set_Ekind (Id, E_Variable);
1031 Set_Etype (Id, Any_Type);
1036 Get_Next_Interp (I, It);
1038 if Present (It.Typ) then
1040 It1 := Disambiguate (Nam, I1, I, Any_Type);
1042 if It1 = No_Interp then
1043 Error_Msg_N ("ambiguous name in object renaming", Nam);
1045 Error_Msg_Sloc := Sloc (It.Nam);
1046 Error_Msg_N ("\\possible interpretation#!", Nam);
1048 Error_Msg_Sloc := Sloc (Nam1);
1049 Error_Msg_N ("\\possible interpretation#!", Nam);
1055 Set_Etype (Nam, It1.Typ);
1060 if Etype (Nam) = Standard_Exception_Type then
1062 ("exception requires a subtype mark in renaming", Nam);
1067 -- The object renaming declaration may become Ghost if it renames a
1070 if Is_Entity_Name (Nam) then
1071 Mark_Ghost_Renaming (N, Entity (Nam));
1074 -- Check against AI12-0401 here before Resolve may rewrite Nam and
1075 -- potentially generate spurious warnings.
1077 if Nkind (Nam) = N_Qualified_Expression
1078 and then Is_Variable (Expression (Nam))
1080 (Subtypes_Statically_Match (T, Etype (Expression (Nam)))
1082 Subtypes_Statically_Match (Base_Type (T), Etype (Nam)))
1085 ("subtype of renamed qualified expression does not " &
1086 "statically match", N);
1092 -- If the renamed object is a function call of a limited type,
1093 -- the expansion of the renaming is complicated by the presence
1094 -- of various temporaries and subtypes that capture constraints
1095 -- of the renamed object. Rewrite node as an object declaration,
1096 -- whose expansion is simpler. Given that the object is limited
1097 -- there is no copy involved and no performance hit.
1099 if Nkind (Nam) = N_Function_Call
1100 and then Is_Limited_View (Etype (Nam))
1101 and then not Is_Constrained (Etype (Nam))
1102 and then Comes_From_Source (N)
1105 Set_Ekind (Id, E_Constant);
1107 Make_Object_Declaration (Loc,
1108 Defining_Identifier => Id,
1109 Constant_Present => True,
1110 Object_Definition => New_Occurrence_Of (Etype (Nam), Loc),
1111 Expression => Relocate_Node (Nam)));
1115 -- Ada 2012 (AI05-149): Reject renaming of an anonymous access object
1116 -- when renaming declaration has a named access type. The Ada 2012
1117 -- coverage rules allow an anonymous access type in the context of
1118 -- an expected named general access type, but the renaming rules
1119 -- require the types to be the same. (An exception is when the type
1120 -- of the renaming is also an anonymous access type, which can only
1121 -- happen due to a renaming created by the expander.)
1123 if Nkind (Nam) = N_Type_Conversion
1124 and then not Comes_From_Source (Nam)
1125 and then Is_Anonymous_Access_Type (Etype (Expression (Nam)))
1126 and then not Is_Anonymous_Access_Type (T)
1128 Wrong_Type (Expression (Nam), T); -- Should we give better error???
1131 -- Check that a class-wide object is not being renamed as an object
1132 -- of a specific type. The test for access types is needed to exclude
1133 -- cases where the renamed object is a dynamically tagged access
1134 -- result, such as occurs in certain expansions.
1136 if Is_Tagged_Type (T) then
1137 Check_Dynamically_Tagged_Expression
1143 -- Ada 2005 (AI-230/AI-254): Access renaming
1145 else pragma Assert (Present (Access_Definition (N)));
1149 N => Access_Definition (N));
1153 -- The object renaming declaration may become Ghost if it renames a
1156 if Is_Entity_Name (Nam) then
1157 Mark_Ghost_Renaming (N, Entity (Nam));
1160 -- Ada 2005 AI05-105: if the declaration has an anonymous access
1161 -- type, the renamed object must also have an anonymous type, and
1162 -- this is a name resolution rule. This was implicit in the last part
1163 -- of the first sentence in 8.5.1(3/2), and is made explicit by this
1166 if not Is_Overloaded (Nam) then
1167 if Ekind (Etype (Nam)) /= Ekind (T) then
1169 ("expect anonymous access type in object renaming", N);
1176 Typ : Entity_Id := Empty;
1177 Seen : Boolean := False;
1180 Get_First_Interp (Nam, I, It);
1181 while Present (It.Typ) loop
1183 -- Renaming is ambiguous if more than one candidate
1184 -- interpretation is type-conformant with the context.
1186 if Ekind (It.Typ) = Ekind (T) then
1187 if Ekind (T) = E_Anonymous_Access_Subprogram_Type
1190 (Designated_Type (T), Designated_Type (It.Typ))
1196 ("ambiguous expression in renaming", Nam);
1199 elsif Ekind (T) = E_Anonymous_Access_Type
1201 Covers (Designated_Type (T), Designated_Type (It.Typ))
1207 ("ambiguous expression in renaming", Nam);
1211 if Covers (T, It.Typ) then
1213 Set_Etype (Nam, Typ);
1214 Set_Is_Overloaded (Nam, False);
1218 Get_Next_Interp (I, It);
1225 -- Do not perform the legality checks below when the resolution of
1226 -- the renaming name failed because the associated type is Any_Type.
1228 if Etype (Nam) = Any_Type then
1231 -- Ada 2005 (AI-231): In the case where the type is defined by an
1232 -- access_definition, the renamed entity shall be of an access-to-
1233 -- constant type if and only if the access_definition defines an
1234 -- access-to-constant type. ARM 8.5.1(4)
1236 elsif Constant_Present (Access_Definition (N))
1237 and then not Is_Access_Constant (Etype (Nam))
1240 ("(Ada 2005): the renamed object is not access-to-constant "
1241 & "(RM 8.5.1(6))", N);
1243 elsif not Constant_Present (Access_Definition (N))
1244 and then Is_Access_Constant (Etype (Nam))
1247 ("(Ada 2005): the renamed object is not access-to-variable "
1248 & "(RM 8.5.1(6))", N);
1251 if Is_Access_Subprogram_Type (Etype (Nam)) then
1252 Check_Subtype_Conformant
1253 (Designated_Type (T), Designated_Type (Etype (Nam)));
1255 elsif not Subtypes_Statically_Match
1256 (Designated_Type (T),
1257 Available_View (Designated_Type (Etype (Nam))))
1260 ("subtype of renamed object does not statically match", N);
1264 -- Special processing for renaming function return object. Some errors
1265 -- and warnings are produced only for calls that come from source.
1267 if Nkind (Nam) = N_Function_Call then
1270 -- Usage is illegal in Ada 83, but renamings are also introduced
1271 -- during expansion, and error does not apply to those.
1274 if Comes_From_Source (N) then
1276 ("(Ada 83) cannot rename function return object", Nam);
1279 -- In Ada 95, warn for odd case of renaming parameterless function
1280 -- call if this is not a limited type (where this is useful).
1283 if Warn_On_Object_Renames_Function
1284 and then No (Parameter_Associations (Nam))
1285 and then not Is_Limited_Type (Etype (Nam))
1286 and then Comes_From_Source (Nam)
1289 ("renaming function result object is suspicious?R?", Nam);
1291 ("\function & will be called only once?R?", Nam,
1292 Entity (Name (Nam)));
1293 Error_Msg_N -- CODEFIX
1294 ("\suggest using an initialized constant object "
1295 & "instead?R?", Nam);
1300 Check_Constrained_Object;
1302 -- An object renaming requires an exact match of the type. Class-wide
1303 -- matching is not allowed.
1305 if Is_Class_Wide_Type (T)
1306 and then Base_Type (Etype (Nam)) /= Base_Type (T)
1308 Wrong_Type (Nam, T);
1311 -- We must search for an actual subtype here so that the bounds of
1312 -- objects of unconstrained types don't get dropped on the floor - such
1313 -- as with renamings of formal parameters.
1315 T2 := Get_Actual_Subtype_If_Available (Nam);
1317 -- Ada 2005 (AI-326): Handle wrong use of incomplete type
1319 if Nkind (Nam) = N_Explicit_Dereference
1320 and then Ekind (Etype (T2)) = E_Incomplete_Type
1322 Error_Msg_NE ("invalid use of incomplete type&", Id, T2);
1325 elsif Ekind (Etype (T)) = E_Incomplete_Type then
1326 Error_Msg_NE ("invalid use of incomplete type&", Id, T);
1330 if Ada_Version >= Ada_2005 and then Nkind (Nam) in N_Has_Entity then
1332 Nam_Ent : constant Entity_Id := Entity (Get_Object_Name (Nam));
1333 Nam_Decl : constant Node_Id := Declaration_Node (Nam_Ent);
1336 if Has_Null_Exclusion (N)
1337 and then not Has_Null_Exclusion (Nam_Decl)
1339 -- Ada 2005 (AI-423): If the object name denotes a generic
1340 -- formal object of a generic unit G, and the object renaming
1341 -- declaration occurs within the body of G or within the body
1342 -- of a generic unit declared within the declarative region
1343 -- of G, then the declaration of the formal object of G must
1344 -- have a null exclusion or a null-excluding subtype.
1346 if Is_Formal_Object (Nam_Ent)
1347 and then In_Generic_Scope (Id)
1349 if not Can_Never_Be_Null (Etype (Nam_Ent)) then
1351 ("object does not exclude `NULL` "
1352 & "(RM 8.5.1(4.6/2))", N);
1354 elsif In_Package_Body (Scope (Id)) then
1356 ("formal object does not have a null exclusion"
1357 & "(RM 8.5.1(4.6/2))", N);
1360 -- Ada 2005 (AI-423): Otherwise, the subtype of the object name
1361 -- shall exclude null.
1363 elsif not Can_Never_Be_Null (Etype (Nam_Ent)) then
1365 ("object does not exclude `NULL` "
1366 & "(RM 8.5.1(4.6/2))", N);
1368 -- An instance is illegal if it contains a renaming that
1369 -- excludes null, and the actual does not. The renaming
1370 -- declaration has already indicated that the declaration
1371 -- of the renamed actual in the instance will raise
1372 -- constraint_error.
1374 elsif Nkind (Nam_Decl) = N_Object_Declaration
1375 and then In_Instance
1377 Present (Corresponding_Generic_Association (Nam_Decl))
1378 and then Nkind (Expression (Nam_Decl)) =
1379 N_Raise_Constraint_Error
1382 ("actual does not exclude `NULL` (RM 8.5.1(4.6/2))", N);
1384 -- Finally, if there is a null exclusion, the subtype mark
1385 -- must not be null-excluding.
1387 elsif No (Access_Definition (N))
1388 and then Can_Never_Be_Null (T)
1391 ("`NOT NULL` not allowed (& already excludes null)",
1396 elsif Can_Never_Be_Null (T)
1397 and then not Can_Never_Be_Null (Etype (Nam_Ent))
1400 ("object does not exclude `NULL` (RM 8.5.1(4.6/2))", N);
1402 elsif Has_Null_Exclusion (N)
1403 and then No (Access_Definition (N))
1404 and then Can_Never_Be_Null (T)
1407 ("`NOT NULL` not allowed (& already excludes null)", N, T);
1412 -- Set the Ekind of the entity, unless it has been set already, as is
1413 -- the case for the iteration object over a container with no variable
1414 -- indexing. In that case it's been marked as a constant, and we do not
1415 -- want to change it to a variable.
1417 if Ekind (Id) /= E_Constant then
1418 Set_Ekind (Id, E_Variable);
1421 -- Initialize the object size and alignment. Note that we used to call
1422 -- Init_Size_Align here, but that's wrong for objects which have only
1423 -- an Esize, not an RM_Size field.
1425 Init_Object_Size_Align (Id);
1427 -- If N comes from source then check that the original node is an
1428 -- object reference since there may have been several rewritting and
1429 -- folding. Do not do this for N_Function_Call or N_Explicit_Dereference
1430 -- which might correspond to rewrites of e.g. N_Selected_Component
1431 -- (for example Object.Method rewriting).
1432 -- If N does not come from source then assume the tree is properly
1433 -- formed and accept any object reference. In such cases we do support
1434 -- more cases of renamings anyway, so the actual check on which renaming
1435 -- is valid is better left to the code generator as a last sanity
1438 if Comes_From_Source (N) then
1439 if Nkind (Nam) in N_Function_Call | N_Explicit_Dereference then
1440 Is_Object_Ref := Is_Object_Reference (Nam);
1442 Is_Object_Ref := Is_Object_Reference (Original_Node (Nam));
1445 Is_Object_Ref := True;
1448 if T = Any_Type or else Etype (Nam) = Any_Type then
1451 -- Verify that the renamed entity is an object or function call
1453 elsif Is_Object_Ref then
1454 if Comes_From_Source (N) then
1455 if Is_Dependent_Component_Of_Mutable_Object (Nam) then
1457 ("illegal renaming of discriminant-dependent component", Nam);
1460 -- If the renaming comes from source and the renamed object is a
1461 -- dereference, then mark the prefix as needing debug information,
1462 -- since it might have been rewritten hence internally generated
1463 -- and Debug_Renaming_Declaration will link the renaming to it.
1465 if Nkind (Nam) = N_Explicit_Dereference
1466 and then Is_Entity_Name (Prefix (Nam))
1468 Set_Debug_Info_Needed (Entity (Prefix (Nam)));
1472 -- Weird but legal, equivalent to renaming a function call. Illegal
1473 -- if the literal is the result of constant-folding an attribute
1474 -- reference that is not a function.
1476 elsif Is_Entity_Name (Nam)
1477 and then Ekind (Entity (Nam)) = E_Enumeration_Literal
1478 and then Nkind (Original_Node (Nam)) /= N_Attribute_Reference
1482 -- A named number can only be renamed without a subtype mark
1484 elsif Nkind (Nam) in N_Real_Literal | N_Integer_Literal
1485 and then Present (Subtype_Mark (N))
1486 and then Present (Original_Entity (Nam))
1488 Error_Msg_N ("incompatible types in renaming", Nam);
1490 -- AI12-0383: Names that denote values can be renamed.
1491 -- Ignore (accept) N_Raise_xxx_Error nodes in this context.
1493 elsif No_Raise_xxx_Error (Nam) = OK then
1494 Error_Msg_Ada_2020_Feature ("value in renaming", Sloc (Nam));
1499 if not Is_Variable (Nam) then
1500 Set_Ekind (Id, E_Constant);
1501 Set_Never_Set_In_Source (Id, True);
1502 Set_Is_True_Constant (Id, True);
1505 -- The entity of the renaming declaration needs to reflect whether the
1506 -- renamed object is atomic, independent, volatile or VFA. These flags
1507 -- are set on the renamed object in the RM legality sense.
1509 Set_Is_Atomic (Id, Is_Atomic_Object (Nam));
1510 Set_Is_Independent (Id, Is_Independent_Object (Nam));
1511 Set_Is_Volatile (Id, Is_Volatile_Object (Nam));
1512 Set_Is_Volatile_Full_Access (Id, Is_Volatile_Full_Access_Object (Nam));
1514 -- Treat as volatile if we just set the Volatile flag
1518 -- Or if we are renaming an entity which was marked this way
1520 -- Are there more cases, e.g. X(J) where X is Treat_As_Volatile ???
1522 or else (Is_Entity_Name (Nam)
1523 and then Treat_As_Volatile (Entity (Nam)))
1525 Set_Treat_As_Volatile (Id, True);
1528 -- Now make the link to the renamed object
1530 Set_Renamed_Object (Id, Nam);
1532 -- Implementation-defined aspect specifications can appear in a renaming
1533 -- declaration, but not language-defined ones. The call to procedure
1534 -- Analyze_Aspect_Specifications will take care of this error check.
1536 if Has_Aspects (N) then
1537 Analyze_Aspect_Specifications (N, Id);
1540 -- Deal with dimensions
1542 Analyze_Dimension (N);
1543 end Analyze_Object_Renaming;
1545 ------------------------------
1546 -- Analyze_Package_Renaming --
1547 ------------------------------
1549 procedure Analyze_Package_Renaming (N : Node_Id) is
1550 New_P : constant Entity_Id := Defining_Entity (N);
1555 if Name (N) = Error then
1559 -- Check for Text_IO special unit (we may be renaming a Text_IO child)
1561 Check_Text_IO_Special_Unit (Name (N));
1563 if Current_Scope /= Standard_Standard then
1564 Set_Is_Pure (New_P, Is_Pure (Current_Scope));
1570 if Is_Entity_Name (Name (N)) then
1571 Old_P := Entity (Name (N));
1576 if Etype (Old_P) = Any_Type then
1577 Error_Msg_N ("expect package name in renaming", Name (N));
1579 elsif Ekind (Old_P) /= E_Package
1580 and then not (Ekind (Old_P) = E_Generic_Package
1581 and then In_Open_Scopes (Old_P))
1583 if Ekind (Old_P) = E_Generic_Package then
1585 ("generic package cannot be renamed as a package", Name (N));
1587 Error_Msg_Sloc := Sloc (Old_P);
1589 ("expect package name in renaming, found& declared#",
1593 -- Set basic attributes to minimize cascaded errors
1595 Set_Ekind (New_P, E_Package);
1596 Set_Etype (New_P, Standard_Void_Type);
1598 elsif Present (Renamed_Entity (Old_P))
1599 and then (From_Limited_With (Renamed_Entity (Old_P))
1600 or else Has_Limited_View (Renamed_Entity (Old_P)))
1602 Unit_Is_Visible (Cunit (Get_Source_Unit (Renamed_Entity (Old_P))))
1605 ("renaming of limited view of package & not usable in this context"
1606 & " (RM 8.5.3(3.1/2))", Name (N), Renamed_Entity (Old_P));
1608 -- Set basic attributes to minimize cascaded errors
1610 Set_Ekind (New_P, E_Package);
1611 Set_Etype (New_P, Standard_Void_Type);
1613 -- Here for OK package renaming
1616 -- Entities in the old package are accessible through the renaming
1617 -- entity. The simplest implementation is to have both packages share
1620 Set_Ekind (New_P, E_Package);
1621 Set_Etype (New_P, Standard_Void_Type);
1623 if Present (Renamed_Object (Old_P)) then
1624 Set_Renamed_Object (New_P, Renamed_Object (Old_P));
1626 Set_Renamed_Object (New_P, Old_P);
1629 -- The package renaming declaration may become Ghost if it renames a
1632 Mark_Ghost_Renaming (N, Old_P);
1634 Set_Has_Completion (New_P);
1635 Set_First_Entity (New_P, First_Entity (Old_P));
1636 Set_Last_Entity (New_P, Last_Entity (Old_P));
1637 Set_First_Private_Entity (New_P, First_Private_Entity (Old_P));
1638 Check_Library_Unit_Renaming (N, Old_P);
1639 Generate_Reference (Old_P, Name (N));
1641 -- If the renaming is in the visible part of a package, then we set
1642 -- Renamed_In_Spec for the renamed package, to prevent giving
1643 -- warnings about no entities referenced. Such a warning would be
1644 -- overenthusiastic, since clients can see entities in the renamed
1645 -- package via the visible package renaming.
1648 Ent : constant Entity_Id := Cunit_Entity (Current_Sem_Unit);
1650 if Ekind (Ent) = E_Package
1651 and then not In_Private_Part (Ent)
1652 and then In_Extended_Main_Source_Unit (N)
1653 and then Ekind (Old_P) = E_Package
1655 Set_Renamed_In_Spec (Old_P);
1659 -- If this is the renaming declaration of a package instantiation
1660 -- within itself, it is the declaration that ends the list of actuals
1661 -- for the instantiation. At this point, the subtypes that rename
1662 -- the actuals are flagged as generic, to avoid spurious ambiguities
1663 -- if the actuals for two distinct formals happen to coincide. If
1664 -- the actual is a private type, the subtype has a private completion
1665 -- that is flagged in the same fashion.
1667 -- Resolution is identical to what is was in the original generic.
1668 -- On exit from the generic instance, these are turned into regular
1669 -- subtypes again, so they are compatible with types in their class.
1671 if not Is_Generic_Instance (Old_P) then
1674 Spec := Specification (Unit_Declaration_Node (Old_P));
1677 if Nkind (Spec) = N_Package_Specification
1678 and then Present (Generic_Parent (Spec))
1679 and then Old_P = Current_Scope
1680 and then Chars (New_P) = Chars (Generic_Parent (Spec))
1686 E := First_Entity (Old_P);
1687 while Present (E) and then E /= New_P loop
1689 and then Nkind (Parent (E)) = N_Subtype_Declaration
1691 Set_Is_Generic_Actual_Type (E);
1693 if Is_Private_Type (E)
1694 and then Present (Full_View (E))
1696 Set_Is_Generic_Actual_Type (Full_View (E));
1706 -- Implementation-defined aspect specifications can appear in a renaming
1707 -- declaration, but not language-defined ones. The call to procedure
1708 -- Analyze_Aspect_Specifications will take care of this error check.
1710 if Has_Aspects (N) then
1711 Analyze_Aspect_Specifications (N, New_P);
1713 end Analyze_Package_Renaming;
1715 -------------------------------
1716 -- Analyze_Renamed_Character --
1717 -------------------------------
1719 procedure Analyze_Renamed_Character
1724 C : constant Node_Id := Name (N);
1727 if Ekind (New_S) = E_Function then
1728 Resolve (C, Etype (New_S));
1731 Check_Frozen_Renaming (N, New_S);
1735 Error_Msg_N ("character literal can only be renamed as function", N);
1737 end Analyze_Renamed_Character;
1739 ---------------------------------
1740 -- Analyze_Renamed_Dereference --
1741 ---------------------------------
1743 procedure Analyze_Renamed_Dereference
1748 Nam : constant Node_Id := Name (N);
1749 P : constant Node_Id := Prefix (Nam);
1755 if not Is_Overloaded (P) then
1756 if Ekind (Etype (Nam)) /= E_Subprogram_Type
1757 or else not Type_Conformant (Etype (Nam), New_S)
1759 Error_Msg_N ("designated type does not match specification", P);
1768 Get_First_Interp (Nam, Ind, It);
1770 while Present (It.Nam) loop
1772 if Ekind (It.Nam) = E_Subprogram_Type
1773 and then Type_Conformant (It.Nam, New_S)
1775 if Typ /= Any_Id then
1776 Error_Msg_N ("ambiguous renaming", P);
1783 Get_Next_Interp (Ind, It);
1786 if Typ = Any_Type then
1787 Error_Msg_N ("designated type does not match specification", P);
1792 Check_Frozen_Renaming (N, New_S);
1796 end Analyze_Renamed_Dereference;
1798 ---------------------------
1799 -- Analyze_Renamed_Entry --
1800 ---------------------------
1802 procedure Analyze_Renamed_Entry
1807 Nam : constant Node_Id := Name (N);
1808 Sel : constant Node_Id := Selector_Name (Nam);
1809 Is_Actual : constant Boolean := Present (Corresponding_Formal_Spec (N));
1813 if Entity (Sel) = Any_Id then
1815 -- Selector is undefined on prefix. Error emitted already
1817 Set_Has_Completion (New_S);
1821 -- Otherwise find renamed entity and build body of New_S as a call to it
1823 Old_S := Find_Renamed_Entity (N, Selector_Name (Nam), New_S);
1825 if Old_S = Any_Id then
1826 Error_Msg_N (" no subprogram or entry matches specification", N);
1829 Check_Subtype_Conformant (New_S, Old_S, N);
1830 Generate_Reference (New_S, Defining_Entity (N), 'b');
1831 Style.Check_Identifier (Defining_Entity (N), New_S);
1834 -- Only mode conformance required for a renaming_as_declaration
1836 Check_Mode_Conformant (New_S, Old_S, N);
1839 Inherit_Renamed_Profile (New_S, Old_S);
1841 -- The prefix can be an arbitrary expression that yields a task or
1842 -- protected object, so it must be resolved.
1844 if Is_Access_Type (Etype (Prefix (Nam))) then
1845 Insert_Explicit_Dereference (Prefix (Nam));
1847 Resolve (Prefix (Nam), Scope (Old_S));
1850 Set_Convention (New_S, Convention (Old_S));
1851 Set_Has_Completion (New_S, Inside_A_Generic);
1853 -- AI05-0225: If the renamed entity is a procedure or entry of a
1854 -- protected object, the target object must be a variable.
1856 if Is_Protected_Type (Scope (Old_S))
1857 and then Ekind (New_S) = E_Procedure
1858 and then not Is_Variable (Prefix (Nam))
1862 ("target object of protected operation used as actual for "
1863 & "formal procedure must be a variable", Nam);
1866 ("target object of protected operation renamed as procedure, "
1867 & "must be a variable", Nam);
1872 Check_Frozen_Renaming (N, New_S);
1874 end Analyze_Renamed_Entry;
1876 -----------------------------------
1877 -- Analyze_Renamed_Family_Member --
1878 -----------------------------------
1880 procedure Analyze_Renamed_Family_Member
1885 Nam : constant Node_Id := Name (N);
1886 P : constant Node_Id := Prefix (Nam);
1890 if (Is_Entity_Name (P) and then Ekind (Entity (P)) = E_Entry_Family)
1891 or else (Nkind (P) = N_Selected_Component
1892 and then Ekind (Entity (Selector_Name (P))) = E_Entry_Family)
1894 if Is_Entity_Name (P) then
1895 Old_S := Entity (P);
1897 Old_S := Entity (Selector_Name (P));
1900 if not Entity_Matches_Spec (Old_S, New_S) then
1901 Error_Msg_N ("entry family does not match specification", N);
1904 Check_Subtype_Conformant (New_S, Old_S, N);
1905 Generate_Reference (New_S, Defining_Entity (N), 'b');
1906 Style.Check_Identifier (Defining_Entity (N), New_S);
1910 Error_Msg_N ("no entry family matches specification", N);
1913 Set_Has_Completion (New_S, Inside_A_Generic);
1916 Check_Frozen_Renaming (N, New_S);
1918 end Analyze_Renamed_Family_Member;
1920 -----------------------------------------
1921 -- Analyze_Renamed_Primitive_Operation --
1922 -----------------------------------------
1924 procedure Analyze_Renamed_Primitive_Operation
1934 Ctyp : Conformance_Type) return Boolean;
1935 -- Verify that the signatures of the renamed entity and the new entity
1936 -- match. The first formal of the renamed entity is skipped because it
1937 -- is the target object in any subsequent call.
1945 Ctyp : Conformance_Type) return Boolean
1951 if Ekind (Subp) /= Ekind (New_S) then
1955 Old_F := Next_Formal (First_Formal (Subp));
1956 New_F := First_Formal (New_S);
1957 while Present (Old_F) and then Present (New_F) loop
1958 if not Conforming_Types (Etype (Old_F), Etype (New_F), Ctyp) then
1962 if Ctyp >= Mode_Conformant
1963 and then Ekind (Old_F) /= Ekind (New_F)
1968 Next_Formal (New_F);
1969 Next_Formal (Old_F);
1975 -- Start of processing for Analyze_Renamed_Primitive_Operation
1978 if not Is_Overloaded (Selector_Name (Name (N))) then
1979 Old_S := Entity (Selector_Name (Name (N)));
1981 if not Conforms (Old_S, Type_Conformant) then
1986 -- Find the operation that matches the given signature
1994 Get_First_Interp (Selector_Name (Name (N)), Ind, It);
1996 while Present (It.Nam) loop
1997 if Conforms (It.Nam, Type_Conformant) then
2001 Get_Next_Interp (Ind, It);
2006 if Old_S = Any_Id then
2007 Error_Msg_N ("no subprogram or entry matches specification", N);
2011 if not Conforms (Old_S, Subtype_Conformant) then
2012 Error_Msg_N ("subtype conformance error in renaming", N);
2015 Generate_Reference (New_S, Defining_Entity (N), 'b');
2016 Style.Check_Identifier (Defining_Entity (N), New_S);
2019 -- Only mode conformance required for a renaming_as_declaration
2021 if not Conforms (Old_S, Mode_Conformant) then
2022 Error_Msg_N ("mode conformance error in renaming", N);
2025 -- AI12-0204: The prefix of a prefixed view that is renamed or
2026 -- passed as a formal subprogram must be renamable as an object.
2028 Nam := Prefix (Name (N));
2030 if Is_Object_Reference (Nam) then
2031 if Is_Dependent_Component_Of_Mutable_Object (Nam) then
2033 ("illegal renaming of discriminant-dependent component",
2037 Error_Msg_N ("expect object name in renaming", Nam);
2040 -- Enforce the rule given in (RM 6.3.1 (10.1/2)): a prefixed
2041 -- view of a subprogram is intrinsic, because the compiler has
2042 -- to generate a wrapper for any call to it. If the name in a
2043 -- subprogram renaming is a prefixed view, the entity is thus
2044 -- intrinsic, and 'Access cannot be applied to it.
2046 Set_Convention (New_S, Convention_Intrinsic);
2049 -- Inherit_Renamed_Profile (New_S, Old_S);
2051 -- The prefix can be an arbitrary expression that yields an
2052 -- object, so it must be resolved.
2054 Resolve (Prefix (Name (N)));
2056 end Analyze_Renamed_Primitive_Operation;
2058 ---------------------------------
2059 -- Analyze_Subprogram_Renaming --
2060 ---------------------------------
2062 procedure Analyze_Subprogram_Renaming (N : Node_Id) is
2063 Formal_Spec : constant Entity_Id := Corresponding_Formal_Spec (N);
2064 Is_Actual : constant Boolean := Present (Formal_Spec);
2065 Nam : constant Node_Id := Name (N);
2066 Save_AV : constant Ada_Version_Type := Ada_Version;
2067 Save_AVP : constant Node_Id := Ada_Version_Pragma;
2068 Save_AV_Exp : constant Ada_Version_Type := Ada_Version_Explicit;
2069 Spec : constant Node_Id := Specification (N);
2071 Old_S : Entity_Id := Empty;
2072 Rename_Spec : Entity_Id;
2074 procedure Build_Class_Wide_Wrapper
2075 (Ren_Id : out Entity_Id;
2076 Wrap_Id : out Entity_Id);
2077 -- Ada 2012 (AI05-0071): A generic/instance scenario involving a formal
2078 -- type with unknown discriminants and a generic primitive operation of
2079 -- the said type with a box require special processing when the actual
2080 -- is a class-wide type:
2083 -- type Formal_Typ (<>) is private;
2084 -- with procedure Prim_Op (Param : Formal_Typ) is <>;
2085 -- package Gen is ...
2087 -- package Inst is new Gen (Actual_Typ'Class);
2089 -- In this case the general renaming mechanism used in the prologue of
2090 -- an instance no longer applies:
2092 -- procedure Prim_Op (Param : Formal_Typ) renames Prim_Op;
2094 -- The above is replaced the following wrapper/renaming combination:
2096 -- procedure Wrapper (Param : Formal_Typ) is -- wrapper
2098 -- Prim_Op (Param); -- primitive
2101 -- procedure Prim_Op (Param : Formal_Typ) renames Wrapper;
2103 -- This transformation applies only if there is no explicit visible
2104 -- class-wide operation at the point of the instantiation. Ren_Id is
2105 -- the entity of the renaming declaration. When the transformation
2106 -- applies, Wrap_Id is the entity of the generated class-wide wrapper
2107 -- (or Any_Id). Otherwise, Wrap_Id is the entity of the class-wide
2110 procedure Check_Null_Exclusion
2113 -- Ada 2005 (AI-423): Given renaming Ren of subprogram Sub, check the
2114 -- following AI rules:
2116 -- If Ren denotes a generic formal object of a generic unit G, and the
2117 -- renaming (or instantiation containing the actual) occurs within the
2118 -- body of G or within the body of a generic unit declared within the
2119 -- declarative region of G, then the corresponding parameter of G
2120 -- shall have a null_exclusion; Otherwise the subtype of the Sub's
2121 -- formal parameter shall exclude null.
2123 -- Similarly for its return profile.
2125 procedure Check_SPARK_Primitive_Operation (Subp_Id : Entity_Id);
2126 -- Ensure that a SPARK renaming denoted by its entity Subp_Id does not
2127 -- declare a primitive operation of a tagged type (SPARK RM 6.1.1(3)).
2129 procedure Freeze_Actual_Profile;
2130 -- In Ada 2012, enforce the freezing rule concerning formal incomplete
2131 -- types: a callable entity freezes its profile, unless it has an
2132 -- incomplete untagged formal (RM 13.14(10.2/3)).
2134 function Has_Class_Wide_Actual return Boolean;
2135 -- Ada 2012 (AI05-071, AI05-0131): True if N is the renaming for a
2136 -- defaulted formal subprogram where the actual for the controlling
2137 -- formal type is class-wide.
2139 function Original_Subprogram (Subp : Entity_Id) return Entity_Id;
2140 -- Find renamed entity when the declaration is a renaming_as_body and
2141 -- the renamed entity may itself be a renaming_as_body. Used to enforce
2142 -- rule that a renaming_as_body is illegal if the declaration occurs
2143 -- before the subprogram it completes is frozen, and renaming indirectly
2144 -- renames the subprogram itself.(Defect Report 8652/0027).
2146 ------------------------------
2147 -- Build_Class_Wide_Wrapper --
2148 ------------------------------
2150 procedure Build_Class_Wide_Wrapper
2151 (Ren_Id : out Entity_Id;
2152 Wrap_Id : out Entity_Id)
2154 Loc : constant Source_Ptr := Sloc (N);
2157 (Subp_Id : Entity_Id;
2158 Params : List_Id) return Node_Id;
2159 -- Create a dispatching call to invoke routine Subp_Id with actuals
2160 -- built from the parameter specifications of list Params.
2162 function Build_Expr_Fun_Call
2163 (Subp_Id : Entity_Id;
2164 Params : List_Id) return Node_Id;
2165 -- Create a dispatching call to invoke function Subp_Id with actuals
2166 -- built from the parameter specifications of list Params. Return
2167 -- directly the call, so that it can be used inside an expression
2168 -- function. This is a specificity of the GNATprove mode.
2170 function Build_Spec (Subp_Id : Entity_Id) return Node_Id;
2171 -- Create a subprogram specification based on the subprogram profile
2174 function Find_Primitive (Typ : Entity_Id) return Entity_Id;
2175 -- Find a primitive subprogram of type Typ which matches the profile
2176 -- of the renaming declaration.
2178 procedure Interpretation_Error (Subp_Id : Entity_Id);
2179 -- Emit a continuation error message suggesting subprogram Subp_Id as
2180 -- a possible interpretation.
2182 function Is_Intrinsic_Equality (Subp_Id : Entity_Id) return Boolean;
2183 -- Determine whether subprogram Subp_Id denotes the intrinsic "="
2186 function Is_Suitable_Candidate (Subp_Id : Entity_Id) return Boolean;
2187 -- Determine whether subprogram Subp_Id is a suitable candidate for
2188 -- the role of a wrapped subprogram.
2195 (Subp_Id : Entity_Id;
2196 Params : List_Id) return Node_Id
2198 Actuals : constant List_Id := New_List;
2199 Call_Ref : constant Node_Id := New_Occurrence_Of (Subp_Id, Loc);
2203 -- Build the actual parameters of the call
2205 Formal := First (Params);
2206 while Present (Formal) loop
2208 Make_Identifier (Loc, Chars (Defining_Identifier (Formal))));
2213 -- return Subp_Id (Actuals);
2215 if Ekind (Subp_Id) in E_Function | E_Operator then
2217 Make_Simple_Return_Statement (Loc,
2219 Make_Function_Call (Loc,
2221 Parameter_Associations => Actuals));
2224 -- Subp_Id (Actuals);
2228 Make_Procedure_Call_Statement (Loc,
2230 Parameter_Associations => Actuals);
2234 -------------------------
2235 -- Build_Expr_Fun_Call --
2236 -------------------------
2238 function Build_Expr_Fun_Call
2239 (Subp_Id : Entity_Id;
2240 Params : List_Id) return Node_Id
2242 Actuals : constant List_Id := New_List;
2243 Call_Ref : constant Node_Id := New_Occurrence_Of (Subp_Id, Loc);
2247 pragma Assert (Ekind (Subp_Id) in E_Function | E_Operator);
2249 -- Build the actual parameters of the call
2251 Formal := First (Params);
2252 while Present (Formal) loop
2254 Make_Identifier (Loc, Chars (Defining_Identifier (Formal))));
2259 -- Subp_Id (Actuals);
2262 Make_Function_Call (Loc,
2264 Parameter_Associations => Actuals);
2265 end Build_Expr_Fun_Call;
2271 function Build_Spec (Subp_Id : Entity_Id) return Node_Id is
2272 Params : constant List_Id := Copy_Parameter_List (Subp_Id);
2273 Spec_Id : constant Entity_Id :=
2274 Make_Defining_Identifier (Loc,
2275 Chars => New_External_Name (Chars (Subp_Id), 'R'));
2278 if Ekind (Formal_Spec) = E_Procedure then
2280 Make_Procedure_Specification (Loc,
2281 Defining_Unit_Name => Spec_Id,
2282 Parameter_Specifications => Params);
2285 Make_Function_Specification (Loc,
2286 Defining_Unit_Name => Spec_Id,
2287 Parameter_Specifications => Params,
2288 Result_Definition =>
2289 New_Copy_Tree (Result_Definition (Spec)));
2293 --------------------
2294 -- Find_Primitive --
2295 --------------------
2297 function Find_Primitive (Typ : Entity_Id) return Entity_Id is
2298 procedure Replace_Parameter_Types (Spec : Node_Id);
2299 -- Given a specification Spec, replace all class-wide parameter
2300 -- types with reference to type Typ.
2302 -----------------------------
2303 -- Replace_Parameter_Types --
2304 -----------------------------
2306 procedure Replace_Parameter_Types (Spec : Node_Id) is
2308 Formal_Id : Entity_Id;
2309 Formal_Typ : Node_Id;
2312 Formal := First (Parameter_Specifications (Spec));
2313 while Present (Formal) loop
2314 Formal_Id := Defining_Identifier (Formal);
2315 Formal_Typ := Parameter_Type (Formal);
2317 -- Create a new entity for each class-wide formal to prevent
2318 -- aliasing with the original renaming. Replace the type of
2319 -- such a parameter with the candidate type.
2321 if Nkind (Formal_Typ) = N_Identifier
2322 and then Is_Class_Wide_Type (Etype (Formal_Typ))
2324 Set_Defining_Identifier (Formal,
2325 Make_Defining_Identifier (Loc, Chars (Formal_Id)));
2327 Set_Parameter_Type (Formal, New_Occurrence_Of (Typ, Loc));
2332 end Replace_Parameter_Types;
2336 Alt_Ren : constant Node_Id := New_Copy_Tree (N);
2337 Alt_Nam : constant Node_Id := Name (Alt_Ren);
2338 Alt_Spec : constant Node_Id := Specification (Alt_Ren);
2339 Subp_Id : Entity_Id;
2341 -- Start of processing for Find_Primitive
2344 -- Each attempt to find a suitable primitive of a particular type
2345 -- operates on its own copy of the original renaming. As a result
2346 -- the original renaming is kept decoration and side-effect free.
2348 -- Inherit the overloaded status of the renamed subprogram name
2350 if Is_Overloaded (Nam) then
2351 Set_Is_Overloaded (Alt_Nam);
2352 Save_Interps (Nam, Alt_Nam);
2355 -- The copied renaming is hidden from visibility to prevent the
2356 -- pollution of the enclosing context.
2358 Set_Defining_Unit_Name (Alt_Spec, Make_Temporary (Loc, 'R'));
2360 -- The types of all class-wide parameters must be changed to the
2363 Replace_Parameter_Types (Alt_Spec);
2365 -- Try to find a suitable primitive which matches the altered
2366 -- profile of the renaming specification.
2371 Nam => Name (Alt_Ren),
2372 New_S => Analyze_Subprogram_Specification (Alt_Spec),
2373 Is_Actual => Is_Actual);
2375 -- Do not return Any_Id if the resolion of the altered profile
2376 -- failed as this complicates further checks on the caller side,
2377 -- return Empty instead.
2379 if Subp_Id = Any_Id then
2386 --------------------------
2387 -- Interpretation_Error --
2388 --------------------------
2390 procedure Interpretation_Error (Subp_Id : Entity_Id) is
2392 Error_Msg_Sloc := Sloc (Subp_Id);
2394 if Is_Internal (Subp_Id) then
2396 ("\\possible interpretation: predefined & #",
2400 ("\\possible interpretation: & defined #", Spec, Formal_Spec);
2402 end Interpretation_Error;
2404 ---------------------------
2405 -- Is_Intrinsic_Equality --
2406 ---------------------------
2408 function Is_Intrinsic_Equality (Subp_Id : Entity_Id) return Boolean is
2411 Ekind (Subp_Id) = E_Operator
2412 and then Chars (Subp_Id) = Name_Op_Eq
2413 and then Is_Intrinsic_Subprogram (Subp_Id);
2414 end Is_Intrinsic_Equality;
2416 ---------------------------
2417 -- Is_Suitable_Candidate --
2418 ---------------------------
2420 function Is_Suitable_Candidate (Subp_Id : Entity_Id) return Boolean is
2422 if No (Subp_Id) then
2425 -- An intrinsic subprogram is never a good candidate. This is an
2426 -- indication of a missing primitive, either defined directly or
2427 -- inherited from a parent tagged type.
2429 elsif Is_Intrinsic_Subprogram (Subp_Id) then
2435 end Is_Suitable_Candidate;
2439 Actual_Typ : Entity_Id := Empty;
2440 -- The actual class-wide type for Formal_Typ
2442 CW_Prim_OK : Boolean;
2443 CW_Prim_Op : Entity_Id;
2444 -- The class-wide subprogram (if available) which corresponds to the
2445 -- renamed generic formal subprogram.
2447 Formal_Typ : Entity_Id := Empty;
2448 -- The generic formal type with unknown discriminants
2450 Root_Prim_OK : Boolean;
2451 Root_Prim_Op : Entity_Id;
2452 -- The root type primitive (if available) which corresponds to the
2453 -- renamed generic formal subprogram.
2455 Root_Typ : Entity_Id := Empty;
2456 -- The root type of Actual_Typ
2458 Body_Decl : Node_Id;
2460 Prim_Op : Entity_Id;
2461 Spec_Decl : Node_Id;
2464 -- Start of processing for Build_Class_Wide_Wrapper
2467 -- Analyze the specification of the renaming in case the generation
2468 -- of the class-wide wrapper fails.
2470 Ren_Id := Analyze_Subprogram_Specification (Spec);
2473 -- Do not attempt to build a wrapper if the renaming is in error
2475 if Error_Posted (Nam) then
2479 -- Analyze the renamed name, but do not resolve it. The resolution is
2480 -- completed once a suitable subprogram is found.
2484 -- When the renamed name denotes the intrinsic operator equals, the
2485 -- name must be treated as overloaded. This allows for a potential
2486 -- match against the root type's predefined equality function.
2488 if Is_Intrinsic_Equality (Entity (Nam)) then
2489 Set_Is_Overloaded (Nam);
2490 Collect_Interps (Nam);
2493 -- Step 1: Find the generic formal type with unknown discriminants
2494 -- and its corresponding class-wide actual type from the renamed
2495 -- generic formal subprogram.
2497 Formal := First_Formal (Formal_Spec);
2498 while Present (Formal) loop
2499 if Has_Unknown_Discriminants (Etype (Formal))
2500 and then not Is_Class_Wide_Type (Etype (Formal))
2501 and then Is_Class_Wide_Type (Get_Instance_Of (Etype (Formal)))
2503 Formal_Typ := Etype (Formal);
2504 Actual_Typ := Get_Instance_Of (Formal_Typ);
2505 Root_Typ := Etype (Actual_Typ);
2509 Next_Formal (Formal);
2512 -- The specification of the generic formal subprogram should always
2513 -- contain a formal type with unknown discriminants whose actual is
2514 -- a class-wide type, otherwise this indicates a failure in routine
2515 -- Has_Class_Wide_Actual.
2517 pragma Assert (Present (Formal_Typ));
2519 -- Step 2: Find the proper class-wide subprogram or primitive which
2520 -- corresponds to the renamed generic formal subprogram.
2522 CW_Prim_Op := Find_Primitive (Actual_Typ);
2523 CW_Prim_OK := Is_Suitable_Candidate (CW_Prim_Op);
2524 Root_Prim_Op := Find_Primitive (Root_Typ);
2525 Root_Prim_OK := Is_Suitable_Candidate (Root_Prim_Op);
2527 -- The class-wide actual type has two subprograms which correspond to
2528 -- the renamed generic formal subprogram:
2530 -- with procedure Prim_Op (Param : Formal_Typ);
2532 -- procedure Prim_Op (Param : Actual_Typ); -- may be inherited
2533 -- procedure Prim_Op (Param : Actual_Typ'Class);
2535 -- Even though the declaration of the two subprograms is legal, a
2536 -- call to either one is ambiguous and therefore illegal.
2538 if CW_Prim_OK and Root_Prim_OK then
2540 -- A user-defined primitive has precedence over a predefined one
2542 if Is_Internal (CW_Prim_Op)
2543 and then not Is_Internal (Root_Prim_Op)
2545 Prim_Op := Root_Prim_Op;
2547 elsif Is_Internal (Root_Prim_Op)
2548 and then not Is_Internal (CW_Prim_Op)
2550 Prim_Op := CW_Prim_Op;
2552 elsif CW_Prim_Op = Root_Prim_Op then
2553 Prim_Op := Root_Prim_Op;
2555 -- Otherwise both candidate subprograms are user-defined and
2560 ("ambiguous actual for generic subprogram &",
2562 Interpretation_Error (Root_Prim_Op);
2563 Interpretation_Error (CW_Prim_Op);
2567 elsif CW_Prim_OK and not Root_Prim_OK then
2568 Prim_Op := CW_Prim_Op;
2570 elsif not CW_Prim_OK and Root_Prim_OK then
2571 Prim_Op := Root_Prim_Op;
2573 -- An intrinsic equality may act as a suitable candidate in the case
2574 -- of a null type extension where the parent's equality is hidden. A
2575 -- call to an intrinsic equality is expanded as dispatching.
2577 elsif Present (Root_Prim_Op)
2578 and then Is_Intrinsic_Equality (Root_Prim_Op)
2580 Prim_Op := Root_Prim_Op;
2582 -- Otherwise there are no candidate subprograms. Let the caller
2583 -- diagnose the error.
2589 -- At this point resolution has taken place and the name is no longer
2590 -- overloaded. Mark the primitive as referenced.
2592 Set_Is_Overloaded (Name (N), False);
2593 Set_Referenced (Prim_Op);
2595 -- Do not generate a wrapper when the only candidate is a class-wide
2596 -- subprogram. Instead modify the renaming to directly map the actual
2597 -- to the generic formal.
2599 if CW_Prim_OK and then Prim_Op = CW_Prim_Op then
2601 Rewrite (Nam, New_Occurrence_Of (Prim_Op, Loc));
2605 -- Step 3: Create the declaration and the body of the wrapper, insert
2606 -- all the pieces into the tree.
2608 -- In GNATprove mode, create a function wrapper in the form of an
2609 -- expression function, so that an implicit postcondition relating
2610 -- the result of calling the wrapper function and the result of the
2611 -- dispatching call to the wrapped function is known during proof.
2614 and then Ekind (Ren_Id) in E_Function | E_Operator
2616 New_Spec := Build_Spec (Ren_Id);
2618 Make_Expression_Function (Loc,
2619 Specification => New_Spec,
2622 (Subp_Id => Prim_Op,
2623 Params => Parameter_Specifications (New_Spec)));
2625 Wrap_Id := Defining_Entity (Body_Decl);
2627 -- Otherwise, create separate spec and body for the subprogram
2631 Make_Subprogram_Declaration (Loc,
2632 Specification => Build_Spec (Ren_Id));
2633 Insert_Before_And_Analyze (N, Spec_Decl);
2635 Wrap_Id := Defining_Entity (Spec_Decl);
2638 Make_Subprogram_Body (Loc,
2639 Specification => Build_Spec (Ren_Id),
2640 Declarations => New_List,
2641 Handled_Statement_Sequence =>
2642 Make_Handled_Sequence_Of_Statements (Loc,
2643 Statements => New_List (
2645 (Subp_Id => Prim_Op,
2647 Parameter_Specifications
2648 (Specification (Spec_Decl))))));
2650 Set_Corresponding_Body (Spec_Decl, Defining_Entity (Body_Decl));
2653 -- If the operator carries an Eliminated pragma, indicate that the
2654 -- wrapper is also to be eliminated, to prevent spurious error when
2655 -- using gnatelim on programs that include box-initialization of
2656 -- equality operators.
2658 Set_Is_Eliminated (Wrap_Id, Is_Eliminated (Prim_Op));
2660 -- In GNATprove mode, insert the body in the tree for analysis
2662 if GNATprove_Mode then
2663 Insert_Before_And_Analyze (N, Body_Decl);
2666 -- The generated body does not freeze and must be analyzed when the
2667 -- class-wide wrapper is frozen. The body is only needed if expansion
2670 if Expander_Active then
2671 Append_Freeze_Action (Wrap_Id, Body_Decl);
2674 -- Step 4: The subprogram renaming aliases the wrapper
2676 Rewrite (Nam, New_Occurrence_Of (Wrap_Id, Loc));
2677 end Build_Class_Wide_Wrapper;
2679 --------------------------
2680 -- Check_Null_Exclusion --
2681 --------------------------
2683 procedure Check_Null_Exclusion
2687 Ren_Formal : Entity_Id;
2688 Sub_Formal : Entity_Id;
2690 function Null_Exclusion_Mismatch
2691 (Renaming : Entity_Id; Renamed : Entity_Id) return Boolean;
2692 -- Return True if there is a null exclusion mismatch between
2693 -- Renaming and Renamed, False otherwise.
2695 -----------------------------
2696 -- Null_Exclusion_Mismatch --
2697 -----------------------------
2699 function Null_Exclusion_Mismatch
2700 (Renaming : Entity_Id; Renamed : Entity_Id) return Boolean is
2702 return Has_Null_Exclusion (Parent (Renaming))
2704 not (Has_Null_Exclusion (Parent (Renamed))
2705 or else (Can_Never_Be_Null (Etype (Renamed))
2707 (Is_Formal_Subprogram (Sub)
2708 and then In_Generic_Body (Current_Scope))));
2709 end Null_Exclusion_Mismatch;
2714 Ren_Formal := First_Formal (Ren);
2715 Sub_Formal := First_Formal (Sub);
2716 while Present (Ren_Formal) and then Present (Sub_Formal) loop
2717 if Null_Exclusion_Mismatch (Ren_Formal, Sub_Formal) then
2718 Error_Msg_Sloc := Sloc (Sub_Formal);
2720 ("`NOT NULL` required for parameter &#",
2721 Ren_Formal, Sub_Formal);
2724 Next_Formal (Ren_Formal);
2725 Next_Formal (Sub_Formal);
2728 -- Return profile check
2730 if Nkind (Parent (Ren)) = N_Function_Specification
2731 and then Nkind (Parent (Sub)) = N_Function_Specification
2732 and then Null_Exclusion_Mismatch (Ren, Sub)
2734 Error_Msg_Sloc := Sloc (Sub);
2735 Error_Msg_N ("return must specify `NOT NULL`#", Ren);
2737 end Check_Null_Exclusion;
2739 -------------------------------------
2740 -- Check_SPARK_Primitive_Operation --
2741 -------------------------------------
2743 procedure Check_SPARK_Primitive_Operation (Subp_Id : Entity_Id) is
2744 Prag : constant Node_Id := SPARK_Pragma (Subp_Id);
2748 -- Nothing to do when the subprogram is not subject to SPARK_Mode On
2749 -- because this check applies to SPARK code only.
2751 if not (Present (Prag)
2752 and then Get_SPARK_Mode_From_Annotation (Prag) = On)
2756 -- Nothing to do when the subprogram is not a primitive operation
2758 elsif not Is_Primitive (Subp_Id) then
2762 Typ := Find_Dispatching_Type (Subp_Id);
2764 -- Nothing to do when the subprogram is a primitive operation of an
2771 -- At this point a renaming declaration introduces a new primitive
2772 -- operation for a tagged type.
2774 Error_Msg_Node_2 := Typ;
2776 ("subprogram renaming & cannot declare primitive for type & "
2777 & "(SPARK RM 6.1.1(3))", N, Subp_Id);
2778 end Check_SPARK_Primitive_Operation;
2780 ---------------------------
2781 -- Freeze_Actual_Profile --
2782 ---------------------------
2784 procedure Freeze_Actual_Profile is
2786 Has_Untagged_Inc : Boolean;
2787 Instantiation_Node : constant Node_Id := Parent (N);
2790 if Ada_Version >= Ada_2012 then
2791 F := First_Formal (Formal_Spec);
2792 Has_Untagged_Inc := False;
2793 while Present (F) loop
2794 if Ekind (Etype (F)) = E_Incomplete_Type
2795 and then not Is_Tagged_Type (Etype (F))
2797 Has_Untagged_Inc := True;
2804 if Ekind (Formal_Spec) = E_Function
2805 and then not Is_Tagged_Type (Etype (Formal_Spec))
2807 Has_Untagged_Inc := True;
2810 if not Has_Untagged_Inc then
2811 F := First_Formal (Old_S);
2812 while Present (F) loop
2813 Freeze_Before (Instantiation_Node, Etype (F));
2815 if Is_Incomplete_Or_Private_Type (Etype (F))
2816 and then No (Underlying_Type (Etype (F)))
2818 -- Exclude generic types, or types derived from them.
2819 -- They will be frozen in the enclosing instance.
2821 if Is_Generic_Type (Etype (F))
2822 or else Is_Generic_Type (Root_Type (Etype (F)))
2826 -- A limited view of a type declared elsewhere needs no
2827 -- freezing actions.
2829 elsif From_Limited_With (Etype (F)) then
2834 ("type& must be frozen before this point",
2835 Instantiation_Node, Etype (F));
2843 end Freeze_Actual_Profile;
2845 ---------------------------
2846 -- Has_Class_Wide_Actual --
2847 ---------------------------
2849 function Has_Class_Wide_Actual return Boolean is
2851 Formal_Typ : Entity_Id;
2855 Formal := First_Formal (Formal_Spec);
2856 while Present (Formal) loop
2857 Formal_Typ := Etype (Formal);
2859 if Has_Unknown_Discriminants (Formal_Typ)
2860 and then not Is_Class_Wide_Type (Formal_Typ)
2861 and then Is_Class_Wide_Type (Get_Instance_Of (Formal_Typ))
2866 Next_Formal (Formal);
2871 end Has_Class_Wide_Actual;
2873 -------------------------
2874 -- Original_Subprogram --
2875 -------------------------
2877 function Original_Subprogram (Subp : Entity_Id) return Entity_Id is
2878 Orig_Decl : Node_Id;
2879 Orig_Subp : Entity_Id;
2882 -- First case: renamed entity is itself a renaming
2884 if Present (Alias (Subp)) then
2885 return Alias (Subp);
2887 elsif Nkind (Unit_Declaration_Node (Subp)) = N_Subprogram_Declaration
2888 and then Present (Corresponding_Body (Unit_Declaration_Node (Subp)))
2890 -- Check if renamed entity is a renaming_as_body
2893 Unit_Declaration_Node
2894 (Corresponding_Body (Unit_Declaration_Node (Subp)));
2896 if Nkind (Orig_Decl) = N_Subprogram_Renaming_Declaration then
2897 Orig_Subp := Entity (Name (Orig_Decl));
2899 if Orig_Subp = Rename_Spec then
2901 -- Circularity detected
2906 return (Original_Subprogram (Orig_Subp));
2914 end Original_Subprogram;
2918 CW_Actual : constant Boolean := Has_Class_Wide_Actual;
2919 -- Ada 2012 (AI05-071, AI05-0131): True if the renaming is for a
2920 -- defaulted formal subprogram when the actual for a related formal
2921 -- type is class-wide.
2923 Inst_Node : Node_Id := Empty;
2926 -- Start of processing for Analyze_Subprogram_Renaming
2929 -- We must test for the attribute renaming case before the Analyze
2930 -- call because otherwise Sem_Attr will complain that the attribute
2931 -- is missing an argument when it is analyzed.
2933 if Nkind (Nam) = N_Attribute_Reference then
2935 -- In the case of an abstract formal subprogram association, rewrite
2936 -- an actual given by a stream or Put_Image attribute as the name of
2937 -- the corresponding stream or Put_Image primitive of the type.
2939 -- In a generic context the stream and Put_Image operations are not
2940 -- generated, and this must be treated as a normal attribute
2941 -- reference, to be expanded in subsequent instantiations.
2944 and then Is_Abstract_Subprogram (Formal_Spec)
2945 and then Expander_Active
2948 Prefix_Type : constant Entity_Id := Entity (Prefix (Nam));
2952 -- The class-wide forms of the stream and Put_Image attributes
2953 -- are not primitive dispatching operations (even though they
2954 -- internally dispatch).
2956 if Is_Class_Wide_Type (Prefix_Type) then
2958 ("attribute must be a primitive dispatching operation",
2963 -- Retrieve the primitive subprogram associated with the
2964 -- attribute. This can only be a stream attribute, since those
2965 -- are the only ones that are dispatching (and the actual for
2966 -- an abstract formal subprogram must be dispatching
2969 case Attribute_Name (Nam) is
2972 Find_Optional_Prim_Op (Prefix_Type, TSS_Stream_Input);
2976 Find_Optional_Prim_Op (Prefix_Type, TSS_Stream_Output);
2980 Find_Optional_Prim_Op (Prefix_Type, TSS_Stream_Read);
2984 Find_Optional_Prim_Op (Prefix_Type, TSS_Stream_Write);
2986 when Name_Put_Image =>
2988 Find_Optional_Prim_Op (Prefix_Type, TSS_Put_Image);
2992 ("attribute must be a primitive dispatching operation",
2997 -- If no stream operation was found, and the type is limited,
2998 -- the user should have defined one. This rule does not apply
3002 and then Attribute_Name (Nam) /= Name_Put_Image
3004 if Is_Limited_Type (Prefix_Type) then
3006 ("stream operation not defined for type&",
3010 -- Otherwise, compiler should have generated default
3013 raise Program_Error;
3017 -- Rewrite the attribute into the name of its corresponding
3018 -- primitive dispatching subprogram. We can then proceed with
3019 -- the usual processing for subprogram renamings.
3022 Prim_Name : constant Node_Id :=
3023 Make_Identifier (Sloc (Nam),
3024 Chars => Chars (Prim));
3026 Set_Entity (Prim_Name, Prim);
3027 Rewrite (Nam, Prim_Name);
3032 -- Normal processing for a renaming of an attribute
3035 Attribute_Renaming (N);
3040 -- Check whether this declaration corresponds to the instantiation of a
3041 -- formal subprogram.
3043 -- If this is an instantiation, the corresponding actual is frozen and
3044 -- error messages can be made more precise. If this is a default
3045 -- subprogram, the entity is already established in the generic, and is
3046 -- not retrieved by visibility. If it is a default with a box, the
3047 -- candidate interpretations, if any, have been collected when building
3048 -- the renaming declaration. If overloaded, the proper interpretation is
3049 -- determined in Find_Renamed_Entity. If the entity is an operator,
3050 -- Find_Renamed_Entity applies additional visibility checks.
3053 Inst_Node := Unit_Declaration_Node (Formal_Spec);
3055 -- Check whether the renaming is for a defaulted actual subprogram
3056 -- with a class-wide actual.
3058 if CW_Actual and then Box_Present (Inst_Node) then
3059 Build_Class_Wide_Wrapper (New_S, Old_S);
3061 elsif Is_Entity_Name (Nam)
3062 and then Present (Entity (Nam))
3063 and then not Comes_From_Source (Nam)
3064 and then not Is_Overloaded (Nam)
3066 Old_S := Entity (Nam);
3068 -- The subprogram renaming declaration may become Ghost if it
3069 -- renames a Ghost entity.
3071 Mark_Ghost_Renaming (N, Old_S);
3073 New_S := Analyze_Subprogram_Specification (Spec);
3077 if Ekind (Old_S) = E_Operator then
3081 if Box_Present (Inst_Node) then
3082 Old_S := Find_Renamed_Entity (N, Name (N), New_S, Is_Actual);
3084 -- If there is an immediately visible homonym of the operator
3085 -- and the declaration has a default, this is worth a warning
3086 -- because the user probably did not intend to get the pre-
3087 -- defined operator, visible in the generic declaration. To
3088 -- find if there is an intended candidate, analyze the renaming
3089 -- again in the current context.
3091 elsif Scope (Old_S) = Standard_Standard
3092 and then Present (Default_Name (Inst_Node))
3095 Decl : constant Node_Id := New_Copy_Tree (N);
3099 Set_Entity (Name (Decl), Empty);
3100 Analyze (Name (Decl));
3102 Find_Renamed_Entity (Decl, Name (Decl), New_S, True);
3105 and then In_Open_Scopes (Scope (Hidden))
3106 and then Is_Immediately_Visible (Hidden)
3107 and then Comes_From_Source (Hidden)
3108 and then Hidden /= Old_S
3110 Error_Msg_Sloc := Sloc (Hidden);
3112 ("default subprogram is resolved in the generic "
3113 & "declaration (RM 12.6(17))??", N);
3114 Error_Msg_NE ("\and will not use & #??", N, Hidden);
3123 -- The subprogram renaming declaration may become Ghost if it
3124 -- renames a Ghost entity.
3126 if Is_Entity_Name (Nam) then
3127 Mark_Ghost_Renaming (N, Entity (Nam));
3130 New_S := Analyze_Subprogram_Specification (Spec);
3134 -- Renamed entity must be analyzed first, to avoid being hidden by
3135 -- new name (which might be the same in a generic instance).
3139 -- The subprogram renaming declaration may become Ghost if it renames
3142 if Is_Entity_Name (Nam) then
3143 Mark_Ghost_Renaming (N, Entity (Nam));
3146 -- The renaming defines a new overloaded entity, which is analyzed
3147 -- like a subprogram declaration.
3149 New_S := Analyze_Subprogram_Specification (Spec);
3152 if Current_Scope /= Standard_Standard then
3153 Set_Is_Pure (New_S, Is_Pure (Current_Scope));
3156 -- Set SPARK mode from current context
3158 Set_SPARK_Pragma (New_S, SPARK_Mode_Pragma);
3159 Set_SPARK_Pragma_Inherited (New_S);
3161 Rename_Spec := Find_Corresponding_Spec (N);
3163 -- Case of Renaming_As_Body
3165 if Present (Rename_Spec) then
3166 Check_Previous_Null_Procedure (N, Rename_Spec);
3168 -- Renaming declaration is the completion of the declaration of
3169 -- Rename_Spec. We build an actual body for it at the freezing point.
3171 Set_Corresponding_Spec (N, Rename_Spec);
3173 -- Deal with special case of stream functions of abstract types
3176 if Nkind (Unit_Declaration_Node (Rename_Spec)) =
3177 N_Abstract_Subprogram_Declaration
3179 -- Input stream functions are abstract if the object type is
3180 -- abstract. Similarly, all default stream functions for an
3181 -- interface type are abstract. However, these subprograms may
3182 -- receive explicit declarations in representation clauses, making
3183 -- the attribute subprograms usable as defaults in subsequent
3185 -- In this case we rewrite the declaration to make the subprogram
3186 -- non-abstract. We remove the previous declaration, and insert
3187 -- the new one at the point of the renaming, to prevent premature
3188 -- access to unfrozen types. The new declaration reuses the
3189 -- specification of the previous one, and must not be analyzed.
3192 (Is_Primitive (Entity (Nam))
3194 Is_Abstract_Type (Find_Dispatching_Type (Entity (Nam))));
3196 Old_Decl : constant Node_Id :=
3197 Unit_Declaration_Node (Rename_Spec);
3198 New_Decl : constant Node_Id :=
3199 Make_Subprogram_Declaration (Sloc (N),
3201 Relocate_Node (Specification (Old_Decl)));
3204 Insert_After (N, New_Decl);
3205 Set_Is_Abstract_Subprogram (Rename_Spec, False);
3206 Set_Analyzed (New_Decl);
3210 Set_Corresponding_Body (Unit_Declaration_Node (Rename_Spec), New_S);
3212 if Ada_Version = Ada_83 and then Comes_From_Source (N) then
3213 Error_Msg_N ("(Ada 83) renaming cannot serve as a body", N);
3216 Set_Convention (New_S, Convention (Rename_Spec));
3217 Check_Fully_Conformant (New_S, Rename_Spec);
3218 Set_Public_Status (New_S);
3220 if No_Return (Rename_Spec)
3221 and then not No_Return (Entity (Nam))
3224 ("renamed subprogram & must be No_Return", N, Entity (Nam));
3226 ("\since renaming subprogram is No_Return (RM 6.5.1(7/2))", N);
3229 -- The specification does not introduce new formals, but only
3230 -- repeats the formals of the original subprogram declaration.
3231 -- For cross-reference purposes, and for refactoring tools, we
3232 -- treat the formals of the renaming declaration as body formals.
3234 Reference_Body_Formals (Rename_Spec, New_S);
3236 -- Indicate that the entity in the declaration functions like the
3237 -- corresponding body, and is not a new entity. The body will be
3238 -- constructed later at the freeze point, so indicate that the
3239 -- completion has not been seen yet.
3241 Set_Ekind (New_S, E_Subprogram_Body);
3242 New_S := Rename_Spec;
3243 Set_Has_Completion (Rename_Spec, False);
3245 -- Ada 2005: check overriding indicator
3247 if Present (Overridden_Operation (Rename_Spec)) then
3248 if Must_Not_Override (Specification (N)) then
3250 ("subprogram& overrides inherited operation",
3254 and then not Must_Override (Specification (N))
3256 Style.Missing_Overriding (N, Rename_Spec);
3259 elsif Must_Override (Specification (N)) then
3260 Error_Msg_NE ("subprogram& is not overriding", N, Rename_Spec);
3263 -- AI12-0132: a renames-as-body freezes the expression of any
3264 -- expression function that it renames.
3266 if Is_Entity_Name (Nam)
3267 and then Is_Expression_Function (Entity (Nam))
3268 and then not Inside_A_Generic
3271 (Def_Id => Entity (Nam),
3272 Typ => Etype (Entity (Nam)),
3275 (Original_Node (Unit_Declaration_Node (Entity (Nam)))),
3279 -- Normal subprogram renaming (not renaming as body)
3282 Generate_Definition (New_S);
3283 New_Overloaded_Entity (New_S);
3285 if not (Is_Entity_Name (Nam)
3286 and then Is_Intrinsic_Subprogram (Entity (Nam)))
3288 Check_Delayed_Subprogram (New_S);
3291 -- Verify that a SPARK renaming does not declare a primitive
3292 -- operation of a tagged type.
3294 Check_SPARK_Primitive_Operation (New_S);
3297 -- There is no need for elaboration checks on the new entity, which may
3298 -- be called before the next freezing point where the body will appear.
3299 -- Elaboration checks refer to the real entity, not the one created by
3300 -- the renaming declaration.
3302 Set_Kill_Elaboration_Checks (New_S, True);
3304 -- If we had a previous error, indicate a completion is present to stop
3305 -- junk cascaded messages, but don't take any further action.
3307 if Etype (Nam) = Any_Type then
3308 Set_Has_Completion (New_S);
3311 -- Case where name has the form of a selected component
3313 elsif Nkind (Nam) = N_Selected_Component then
3315 -- A name which has the form A.B can designate an entry of task A, a
3316 -- protected operation of protected object A, or finally a primitive
3317 -- operation of object A. In the later case, A is an object of some
3318 -- tagged type, or an access type that denotes one such. To further
3319 -- distinguish these cases, note that the scope of a task entry or
3320 -- protected operation is type of the prefix.
3322 -- The prefix could be an overloaded function call that returns both
3323 -- kinds of operations. This overloading pathology is left to the
3324 -- dedicated reader ???
3327 T : constant Entity_Id := Etype (Prefix (Nam));
3335 and then Is_Tagged_Type (Designated_Type (T))))
3336 and then Scope (Entity (Selector_Name (Nam))) /= T
3338 Analyze_Renamed_Primitive_Operation
3339 (N, New_S, Present (Rename_Spec));
3343 -- Renamed entity is an entry or protected operation. For those
3344 -- cases an explicit body is built (at the point of freezing of
3345 -- this entity) that contains a call to the renamed entity.
3347 -- This is not allowed for renaming as body if the renamed
3348 -- spec is already frozen (see RM 8.5.4(5) for details).
3350 if Present (Rename_Spec) and then Is_Frozen (Rename_Spec) then
3352 ("renaming-as-body cannot rename entry as subprogram", N);
3354 ("\since & is already frozen (RM 8.5.4(5))",
3357 Analyze_Renamed_Entry (N, New_S, Present (Rename_Spec));
3364 -- Case where name is an explicit dereference X.all
3366 elsif Nkind (Nam) = N_Explicit_Dereference then
3368 -- Renamed entity is designated by access_to_subprogram expression.
3369 -- Must build body to encapsulate call, as in the entry case.
3371 Analyze_Renamed_Dereference (N, New_S, Present (Rename_Spec));
3374 -- Indexed component
3376 elsif Nkind (Nam) = N_Indexed_Component then
3377 Analyze_Renamed_Family_Member (N, New_S, Present (Rename_Spec));
3380 -- Character literal
3382 elsif Nkind (Nam) = N_Character_Literal then
3383 Analyze_Renamed_Character (N, New_S, Present (Rename_Spec));
3386 -- Only remaining case is where we have a non-entity name, or a renaming
3387 -- of some other non-overloadable entity.
3389 elsif not Is_Entity_Name (Nam)
3390 or else not Is_Overloadable (Entity (Nam))
3392 -- Do not mention the renaming if it comes from an instance
3394 if not Is_Actual then
3395 Error_Msg_N ("expect valid subprogram name in renaming", N);
3397 Error_Msg_NE ("no visible subprogram for formal&", N, Nam);
3403 -- Find the renamed entity that matches the given specification. Disable
3404 -- Ada_83 because there is no requirement of full conformance between
3405 -- renamed entity and new entity, even though the same circuit is used.
3407 -- This is a bit of an odd case, which introduces a really irregular use
3408 -- of Ada_Version[_Explicit]. Would be nice to find cleaner way to do
3411 Ada_Version := Ada_Version_Type'Max (Ada_Version, Ada_95);
3412 Ada_Version_Pragma := Empty;
3413 Ada_Version_Explicit := Ada_Version;
3416 Old_S := Find_Renamed_Entity (N, Name (N), New_S, Is_Actual);
3418 -- The visible operation may be an inherited abstract operation that
3419 -- was overridden in the private part, in which case a call will
3420 -- dispatch to the overriding operation. Use the overriding one in
3421 -- the renaming declaration, to prevent spurious errors below.
3423 if Is_Overloadable (Old_S)
3424 and then Is_Abstract_Subprogram (Old_S)
3425 and then No (DTC_Entity (Old_S))
3426 and then Present (Alias (Old_S))
3427 and then not Is_Abstract_Subprogram (Alias (Old_S))
3428 and then Present (Overridden_Operation (Alias (Old_S)))
3430 Old_S := Alias (Old_S);
3433 -- When the renamed subprogram is overloaded and used as an actual
3434 -- of a generic, its entity is set to the first available homonym.
3435 -- We must first disambiguate the name, then set the proper entity.
3437 if Is_Actual and then Is_Overloaded (Nam) then
3438 Set_Entity (Nam, Old_S);
3442 -- Most common case: subprogram renames subprogram. No body is generated
3443 -- in this case, so we must indicate the declaration is complete as is.
3444 -- and inherit various attributes of the renamed subprogram.
3446 if No (Rename_Spec) then
3447 Set_Has_Completion (New_S);
3448 Set_Is_Imported (New_S, Is_Imported (Entity (Nam)));
3449 Set_Is_Pure (New_S, Is_Pure (Entity (Nam)));
3450 Set_Is_Preelaborated (New_S, Is_Preelaborated (Entity (Nam)));
3452 -- Ada 2005 (AI-423): Check the consistency of null exclusions
3453 -- between a subprogram and its correct renaming.
3455 -- Note: the Any_Id check is a guard that prevents compiler crashes
3456 -- when performing a null exclusion check between a renaming and a
3457 -- renamed subprogram that has been found to be illegal.
3459 if Ada_Version >= Ada_2005 and then Entity (Nam) /= Any_Id then
3460 Check_Null_Exclusion
3462 Sub => Entity (Nam));
3465 -- Enforce the Ada 2005 rule that the renamed entity cannot require
3466 -- overriding. The flag Requires_Overriding is set very selectively
3467 -- and misses some other illegal cases. The additional conditions
3468 -- checked below are sufficient but not necessary ???
3470 -- The rule does not apply to the renaming generated for an actual
3471 -- subprogram in an instance.
3476 -- Guard against previous errors, and omit renamings of predefined
3479 elsif Ekind (Old_S) not in E_Function | E_Procedure then
3482 elsif Requires_Overriding (Old_S)
3484 (Is_Abstract_Subprogram (Old_S)
3485 and then Present (Find_Dispatching_Type (Old_S))
3486 and then not Is_Abstract_Type (Find_Dispatching_Type (Old_S)))
3489 ("renamed entity cannot be subprogram that requires overriding "
3490 & "(RM 8.5.4 (5.1))", N);
3494 Prev : constant Entity_Id := Overridden_Operation (New_S);
3498 (Has_Non_Trivial_Precondition (Prev)
3499 or else Has_Non_Trivial_Precondition (Old_S))
3502 ("conflicting inherited classwide preconditions in renaming "
3503 & "of& (RM 6.1.1 (17)", N, Old_S);
3508 if Old_S /= Any_Id then
3509 if Is_Actual and then From_Default (N) then
3511 -- This is an implicit reference to the default actual
3513 Generate_Reference (Old_S, Nam, Typ => 'i', Force => True);
3516 Generate_Reference (Old_S, Nam);
3519 Check_Internal_Protected_Use (N, Old_S);
3521 -- For a renaming-as-body, require subtype conformance, but if the
3522 -- declaration being completed has not been frozen, then inherit the
3523 -- convention of the renamed subprogram prior to checking conformance
3524 -- (unless the renaming has an explicit convention established; the
3525 -- rule stated in the RM doesn't seem to address this ???).
3527 if Present (Rename_Spec) then
3528 Generate_Reference (Rename_Spec, Defining_Entity (Spec), 'b');
3529 Style.Check_Identifier (Defining_Entity (Spec), Rename_Spec);
3531 if not Is_Frozen (Rename_Spec) then
3532 if not Has_Convention_Pragma (Rename_Spec) then
3533 Set_Convention (New_S, Convention (Old_S));
3536 if Ekind (Old_S) /= E_Operator then
3537 Check_Mode_Conformant (New_S, Old_S, Spec);
3540 if Original_Subprogram (Old_S) = Rename_Spec then
3541 Error_Msg_N ("unfrozen subprogram cannot rename itself ", N);
3543 Check_Formal_Subprogram_Conformance (New_S, Old_S, Spec);
3546 Check_Subtype_Conformant (New_S, Old_S, Spec);
3549 Check_Frozen_Renaming (N, Rename_Spec);
3551 -- Check explicitly that renamed entity is not intrinsic, because
3552 -- in a generic the renamed body is not built. In this case,
3553 -- the renaming_as_body is a completion.
3555 if Inside_A_Generic then
3556 if Is_Frozen (Rename_Spec)
3557 and then Is_Intrinsic_Subprogram (Old_S)
3560 ("subprogram in renaming_as_body cannot be intrinsic",
3564 Set_Has_Completion (Rename_Spec);
3567 elsif Ekind (Old_S) /= E_Operator then
3569 -- If this a defaulted subprogram for a class-wide actual there is
3570 -- no check for mode conformance, given that the signatures don't
3571 -- match (the source mentions T but the actual mentions T'Class).
3576 -- No need for a redundant error message if this is a nested
3577 -- instance, unless the current instantiation (of a child unit)
3578 -- is a compilation unit, which is not analyzed when the parent
3579 -- generic is analyzed.
3582 or else No (Enclosing_Instance)
3583 or else Is_Compilation_Unit (Current_Scope)
3585 Check_Mode_Conformant (New_S, Old_S);
3589 if No (Rename_Spec) then
3591 -- The parameter profile of the new entity is that of the renamed
3592 -- entity: the subtypes given in the specification are irrelevant.
3594 Inherit_Renamed_Profile (New_S, Old_S);
3596 -- A call to the subprogram is transformed into a call to the
3597 -- renamed entity. This is transitive if the renamed entity is
3598 -- itself a renaming.
3600 if Present (Alias (Old_S)) then
3601 Set_Alias (New_S, Alias (Old_S));
3603 Set_Alias (New_S, Old_S);
3606 -- Note that we do not set Is_Intrinsic_Subprogram if we have a
3607 -- renaming as body, since the entity in this case is not an
3608 -- intrinsic (it calls an intrinsic, but we have a real body for
3609 -- this call, and it is in this body that the required intrinsic
3610 -- processing will take place).
3612 -- Also, if this is a renaming of inequality, the renamed operator
3613 -- is intrinsic, but what matters is the corresponding equality
3614 -- operator, which may be user-defined.
3616 Set_Is_Intrinsic_Subprogram
3618 Is_Intrinsic_Subprogram (Old_S)
3620 (Chars (Old_S) /= Name_Op_Ne
3621 or else Ekind (Old_S) = E_Operator
3622 or else Is_Intrinsic_Subprogram
3623 (Corresponding_Equality (Old_S))));
3625 if Ekind (Alias (New_S)) = E_Operator then
3626 Set_Has_Delayed_Freeze (New_S, False);
3629 -- If the renaming corresponds to an association for an abstract
3630 -- formal subprogram, then various attributes must be set to
3631 -- indicate that the renaming is an abstract dispatching operation
3632 -- with a controlling type.
3634 if Is_Actual and then Is_Abstract_Subprogram (Formal_Spec) then
3636 -- Mark the renaming as abstract here, so Find_Dispatching_Type
3637 -- see it as corresponding to a generic association for a
3638 -- formal abstract subprogram
3640 Set_Is_Abstract_Subprogram (New_S);
3643 New_S_Ctrl_Type : constant Entity_Id :=
3644 Find_Dispatching_Type (New_S);
3645 Old_S_Ctrl_Type : constant Entity_Id :=
3646 Find_Dispatching_Type (Old_S);
3650 -- The actual must match the (instance of the) formal,
3651 -- and must be a controlling type.
3653 if Old_S_Ctrl_Type /= New_S_Ctrl_Type
3654 or else No (New_S_Ctrl_Type)
3656 if No (New_S_Ctrl_Type) then
3658 ("actual must be dispatching subprogram", Nam);
3661 ("actual must be dispatching subprogram for type&",
3662 Nam, New_S_Ctrl_Type);
3666 Set_Is_Dispatching_Operation (New_S);
3667 Check_Controlling_Formals (New_S_Ctrl_Type, New_S);
3669 -- If the actual in the formal subprogram is itself a
3670 -- formal abstract subprogram association, there's no
3671 -- dispatch table component or position to inherit.
3673 if Present (DTC_Entity (Old_S)) then
3674 Set_DTC_Entity (New_S, DTC_Entity (Old_S));
3675 Set_DT_Position_Value (New_S, DT_Position (Old_S));
3685 -- The following is illegal, because F hides whatever other F may
3687 -- function F (...) renames F;
3690 or else (Nkind (Nam) /= N_Expanded_Name
3691 and then Chars (Old_S) = Chars (New_S))
3693 Error_Msg_N ("subprogram cannot rename itself", N);
3695 -- This is illegal even if we use a selector:
3696 -- function F (...) renames Pkg.F;
3697 -- because F is still hidden.
3699 elsif Nkind (Nam) = N_Expanded_Name
3700 and then Entity (Prefix (Nam)) = Current_Scope
3701 and then Chars (Selector_Name (Nam)) = Chars (New_S)
3703 -- This is an error, but we overlook the error and accept the
3704 -- renaming if the special Overriding_Renamings mode is in effect.
3706 if not Overriding_Renamings then
3708 ("implicit operation& is not visible (RM 8.3 (15))",
3713 Set_Convention (New_S, Convention (Old_S));
3715 if Is_Abstract_Subprogram (Old_S) then
3716 if Present (Rename_Spec) then
3718 ("a renaming-as-body cannot rename an abstract subprogram",
3720 Set_Has_Completion (Rename_Spec);
3722 Set_Is_Abstract_Subprogram (New_S);
3726 Check_Library_Unit_Renaming (N, Old_S);
3728 -- Pathological case: procedure renames entry in the scope of its
3729 -- task. Entry is given by simple name, but body must be built for
3730 -- procedure. Of course if called it will deadlock.
3732 if Ekind (Old_S) = E_Entry then
3733 Set_Has_Completion (New_S, False);
3734 Set_Alias (New_S, Empty);
3737 -- Do not freeze the renaming nor the renamed entity when the context
3738 -- is an enclosing generic. Freezing is an expansion activity, and in
3739 -- addition the renamed entity may depend on the generic formals of
3740 -- the enclosing generic.
3742 if Is_Actual and not Inside_A_Generic then
3743 Freeze_Before (N, Old_S);
3744 Freeze_Actual_Profile;
3745 Set_Has_Delayed_Freeze (New_S, False);
3746 Freeze_Before (N, New_S);
3748 -- An abstract subprogram is only allowed as an actual in the case
3749 -- where the formal subprogram is also abstract.
3751 if (Ekind (Old_S) = E_Procedure or else Ekind (Old_S) = E_Function)
3752 and then Is_Abstract_Subprogram (Old_S)
3753 and then not Is_Abstract_Subprogram (Formal_Spec)
3756 ("abstract subprogram not allowed as generic actual", Nam);
3761 -- A common error is to assume that implicit operators for types are
3762 -- defined in Standard, or in the scope of a subtype. In those cases
3763 -- where the renamed entity is given with an expanded name, it is
3764 -- worth mentioning that operators for the type are not declared in
3765 -- the scope given by the prefix.
3767 if Nkind (Nam) = N_Expanded_Name
3768 and then Nkind (Selector_Name (Nam)) = N_Operator_Symbol
3769 and then Scope (Entity (Nam)) = Standard_Standard
3772 T : constant Entity_Id :=
3773 Base_Type (Etype (First_Formal (New_S)));
3775 Error_Msg_Node_2 := Prefix (Nam);
3777 ("operator for type& is not declared in&", Prefix (Nam), T);
3782 ("no visible subprogram matches the specification for&",
3786 if Present (Candidate_Renaming) then
3793 F1 := First_Formal (Candidate_Renaming);
3794 F2 := First_Formal (New_S);
3795 T1 := First_Subtype (Etype (F1));
3796 while Present (F1) and then Present (F2) loop
3801 if Present (F1) and then Present (Default_Value (F1)) then
3802 if Present (Next_Formal (F1)) then
3804 ("\missing specification for & and other formals with "
3805 & "defaults", Spec, F1);
3807 Error_Msg_NE ("\missing specification for &", Spec, F1);
3811 if Nkind (Nam) = N_Operator_Symbol
3812 and then From_Default (N)
3814 Error_Msg_Node_2 := T1;
3816 ("default & on & is not directly visible", Nam, Nam);
3822 -- Ada 2005 AI 404: if the new subprogram is dispatching, verify that
3823 -- controlling access parameters are known non-null for the renamed
3824 -- subprogram. Test also applies to a subprogram instantiation that
3825 -- is dispatching. Test is skipped if some previous error was detected
3826 -- that set Old_S to Any_Id.
3828 if Ada_Version >= Ada_2005
3829 and then Old_S /= Any_Id
3830 and then not Is_Dispatching_Operation (Old_S)
3831 and then Is_Dispatching_Operation (New_S)
3838 Old_F := First_Formal (Old_S);
3839 New_F := First_Formal (New_S);
3840 while Present (Old_F) loop
3841 if Ekind (Etype (Old_F)) = E_Anonymous_Access_Type
3842 and then Is_Controlling_Formal (New_F)
3843 and then not Can_Never_Be_Null (Old_F)
3845 Error_Msg_N ("access parameter is controlling,", New_F);
3847 ("\corresponding parameter of& must be explicitly null "
3848 & "excluding", New_F, Old_S);
3851 Next_Formal (Old_F);
3852 Next_Formal (New_F);
3857 -- A useful warning, suggested by Ada Bug Finder (Ada-Europe 2005)
3858 -- is to warn if an operator is being renamed as a different operator.
3859 -- If the operator is predefined, examine the kind of the entity, not
3860 -- the abbreviated declaration in Standard.
3862 if Comes_From_Source (N)
3863 and then Present (Old_S)
3864 and then (Nkind (Old_S) = N_Defining_Operator_Symbol
3865 or else Ekind (Old_S) = E_Operator)
3866 and then Nkind (New_S) = N_Defining_Operator_Symbol
3867 and then Chars (Old_S) /= Chars (New_S)
3870 ("& is being renamed as a different operator??", N, Old_S);
3873 -- Check for renaming of obsolescent subprogram
3875 Check_Obsolescent_2005_Entity (Entity (Nam), Nam);
3877 -- Another warning or some utility: if the new subprogram as the same
3878 -- name as the old one, the old one is not hidden by an outer homograph,
3879 -- the new one is not a public symbol, and the old one is otherwise
3880 -- directly visible, the renaming is superfluous.
3882 if Chars (Old_S) = Chars (New_S)
3883 and then Comes_From_Source (N)
3884 and then Scope (Old_S) /= Standard_Standard
3885 and then Warn_On_Redundant_Constructs
3886 and then (Is_Immediately_Visible (Old_S)
3887 or else Is_Potentially_Use_Visible (Old_S))
3888 and then Is_Overloadable (Current_Scope)
3889 and then Chars (Current_Scope) /= Chars (Old_S)
3892 ("redundant renaming, entity is directly visible?r?", Name (N));
3895 -- Implementation-defined aspect specifications can appear in a renaming
3896 -- declaration, but not language-defined ones. The call to procedure
3897 -- Analyze_Aspect_Specifications will take care of this error check.
3899 if Has_Aspects (N) then
3900 Analyze_Aspect_Specifications (N, New_S);
3906 and then Has_Yield_Aspect (Formal_Spec)
3907 and then not Has_Yield_Aspect (Old_S)
3909 Error_Msg_Name_1 := Name_Yield;
3911 ("actual subprogram& must have aspect% to match formal", Name (N));
3914 Ada_Version := Save_AV;
3915 Ada_Version_Pragma := Save_AVP;
3916 Ada_Version_Explicit := Save_AV_Exp;
3918 -- Check if we are looking at an Ada 2012 defaulted formal subprogram
3919 -- and mark any use_package_clauses that affect the visibility of the
3920 -- implicit generic actual.
3922 -- Also, we may be looking at an internal renaming of a user-defined
3923 -- subprogram created for a generic formal subprogram association,
3924 -- which will also have to be marked here. This can occur when the
3925 -- corresponding formal subprogram contains references to other generic
3928 if Is_Generic_Actual_Subprogram (New_S)
3929 and then (Is_Intrinsic_Subprogram (New_S)
3930 or else From_Default (N)
3931 or else Nkind (N) = N_Subprogram_Renaming_Declaration)
3933 Mark_Use_Clauses (New_S);
3935 -- Handle overloaded subprograms
3937 if Present (Alias (New_S)) then
3938 Mark_Use_Clauses (Alias (New_S));
3941 end Analyze_Subprogram_Renaming;
3943 -------------------------
3944 -- Analyze_Use_Package --
3945 -------------------------
3947 -- Resolve the package names in the use clause, and make all the visible
3948 -- entities defined in the package potentially use-visible. If the package
3949 -- is already in use from a previous use clause, its visible entities are
3950 -- already use-visible. In that case, mark the occurrence as a redundant
3951 -- use. If the package is an open scope, i.e. if the use clause occurs
3952 -- within the package itself, ignore it.
3954 procedure Analyze_Use_Package (N : Node_Id; Chain : Boolean := True) is
3955 procedure Analyze_Package_Name (Clause : Node_Id);
3956 -- Perform analysis on a package name from a use_package_clause
3958 procedure Analyze_Package_Name_List (Head_Clause : Node_Id);
3959 -- Similar to Analyze_Package_Name but iterates over all the names
3962 --------------------------
3963 -- Analyze_Package_Name --
3964 --------------------------
3966 procedure Analyze_Package_Name (Clause : Node_Id) is
3967 Pack : constant Node_Id := Name (Clause);
3971 pragma Assert (Nkind (Clause) = N_Use_Package_Clause);
3974 -- Verify that the package standard is not directly named in a
3975 -- use_package_clause.
3977 if Nkind (Parent (Clause)) = N_Compilation_Unit
3978 and then Nkind (Pack) = N_Expanded_Name
3980 Pref := Prefix (Pack);
3982 while Nkind (Pref) = N_Expanded_Name loop
3983 Pref := Prefix (Pref);
3986 if Entity (Pref) = Standard_Standard then
3988 ("predefined package Standard cannot appear in a context "
3992 end Analyze_Package_Name;
3994 -------------------------------
3995 -- Analyze_Package_Name_List --
3996 -------------------------------
3998 procedure Analyze_Package_Name_List (Head_Clause : Node_Id) is
4002 -- Due to the way source use clauses are split during parsing we are
4003 -- forced to simply iterate through all entities in scope until the
4004 -- clause representing the last name in the list is found.
4006 Curr := Head_Clause;
4007 while Present (Curr) loop
4008 Analyze_Package_Name (Curr);
4010 -- Stop iterating over the names in the use clause when we are at
4013 exit when not More_Ids (Curr) and then Prev_Ids (Curr);
4016 end Analyze_Package_Name_List;
4022 -- Start of processing for Analyze_Use_Package
4025 Set_Hidden_By_Use_Clause (N, No_Elist);
4027 -- Use clause not allowed in a spec of a predefined package declaration
4028 -- except that packages whose file name starts a-n are OK (these are
4029 -- children of Ada.Numerics, which are never loaded by Rtsfind).
4031 if Is_Predefined_Unit (Current_Sem_Unit)
4032 and then Get_Name_String
4033 (Unit_File_Name (Current_Sem_Unit)) (1 .. 3) /= "a-n"
4034 and then Nkind (Unit (Cunit (Current_Sem_Unit))) =
4035 N_Package_Declaration
4037 Error_Msg_N ("use clause not allowed in predefined spec", N);
4040 -- Loop through all package names from the original use clause in
4041 -- order to analyze referenced packages. A use_package_clause with only
4042 -- one name does not have More_Ids or Prev_Ids set, while a clause with
4043 -- More_Ids only starts the chain produced by the parser.
4045 if not More_Ids (N) and then not Prev_Ids (N) then
4046 Analyze_Package_Name (N);
4048 elsif More_Ids (N) and then not Prev_Ids (N) then
4049 Analyze_Package_Name_List (N);
4052 if not Is_Entity_Name (Name (N)) then
4053 Error_Msg_N ("& is not a package", Name (N));
4059 Chain_Use_Clause (N);
4062 Pack := Entity (Name (N));
4064 -- There are many cases where scopes are manipulated during analysis, so
4065 -- check that Pack's current use clause has not already been chained
4066 -- before setting its previous use clause.
4068 if Ekind (Pack) = E_Package
4069 and then Present (Current_Use_Clause (Pack))
4070 and then Current_Use_Clause (Pack) /= N
4071 and then No (Prev_Use_Clause (N))
4072 and then Prev_Use_Clause (Current_Use_Clause (Pack)) /= N
4074 Set_Prev_Use_Clause (N, Current_Use_Clause (Pack));
4077 -- Mark all entities as potentially use visible
4079 if Ekind (Pack) /= E_Package and then Etype (Pack) /= Any_Type then
4080 if Ekind (Pack) = E_Generic_Package then
4081 Error_Msg_N -- CODEFIX
4082 ("a generic package is not allowed in a use clause", Name (N));
4084 elsif Is_Generic_Subprogram (Pack) then
4085 Error_Msg_N -- CODEFIX
4086 ("a generic subprogram is not allowed in a use clause",
4089 elsif Is_Subprogram (Pack) then
4090 Error_Msg_N -- CODEFIX
4091 ("a subprogram is not allowed in a use clause", Name (N));
4094 Error_Msg_N ("& is not allowed in a use clause", Name (N));
4098 if Nkind (Parent (N)) = N_Compilation_Unit then
4099 Check_In_Previous_With_Clause (N, Name (N));
4102 Use_One_Package (N, Name (N));
4105 Mark_Ghost_Clause (N);
4106 end Analyze_Use_Package;
4108 ----------------------
4109 -- Analyze_Use_Type --
4110 ----------------------
4112 procedure Analyze_Use_Type (N : Node_Id; Chain : Boolean := True) is
4117 Set_Hidden_By_Use_Clause (N, No_Elist);
4119 -- Chain clause to list of use clauses in current scope when flagged
4122 Chain_Use_Clause (N);
4125 -- Obtain the base type of the type denoted within the use_type_clause's
4128 Id := Subtype_Mark (N);
4130 E := Base_Type (Entity (Id));
4132 -- There are many cases where a use_type_clause may be reanalyzed due to
4133 -- manipulation of the scope stack so we much guard against those cases
4134 -- here, otherwise, we must add the new use_type_clause to the previous
4135 -- use_type_clause chain in order to mark redundant use_type_clauses as
4136 -- used. When the redundant use-type clauses appear in a parent unit and
4137 -- a child unit we must prevent a circularity in the chain that would
4138 -- otherwise result from the separate steps of analysis and installation
4139 -- of the parent context.
4141 if Present (Current_Use_Clause (E))
4142 and then Current_Use_Clause (E) /= N
4143 and then Prev_Use_Clause (Current_Use_Clause (E)) /= N
4144 and then No (Prev_Use_Clause (N))
4146 Set_Prev_Use_Clause (N, Current_Use_Clause (E));
4149 -- If the Used_Operations list is already initialized, the clause has
4150 -- been analyzed previously, and it is being reinstalled, for example
4151 -- when the clause appears in a package spec and we are compiling the
4152 -- corresponding package body. In that case, make the entities on the
4153 -- existing list use_visible, and mark the corresponding types In_Use.
4155 if Present (Used_Operations (N)) then
4160 Use_One_Type (Subtype_Mark (N), Installed => True);
4162 Elmt := First_Elmt (Used_Operations (N));
4163 while Present (Elmt) loop
4164 Set_Is_Potentially_Use_Visible (Node (Elmt));
4172 -- Otherwise, create new list and attach to it the operations that are
4173 -- made use-visible by the clause.
4175 Set_Used_Operations (N, New_Elmt_List);
4178 if E /= Any_Type then
4181 if Nkind (Parent (N)) = N_Compilation_Unit then
4182 if Nkind (Id) = N_Identifier then
4183 Error_Msg_N ("type is not directly visible", Id);
4185 elsif Is_Child_Unit (Scope (E))
4186 and then Scope (E) /= System_Aux_Id
4188 Check_In_Previous_With_Clause (N, Prefix (Id));
4193 -- If the use_type_clause appears in a compilation unit context,
4194 -- check whether it comes from a unit that may appear in a
4195 -- limited_with_clause, for a better error message.
4197 if Nkind (Parent (N)) = N_Compilation_Unit
4198 and then Nkind (Id) /= N_Identifier
4204 function Mentioned (Nam : Node_Id) return Boolean;
4205 -- Check whether the prefix of expanded name for the type
4206 -- appears in the prefix of some limited_with_clause.
4212 function Mentioned (Nam : Node_Id) return Boolean is
4214 return Nkind (Name (Item)) = N_Selected_Component
4215 and then Chars (Prefix (Name (Item))) = Chars (Nam);
4219 Pref := Prefix (Id);
4220 Item := First (Context_Items (Parent (N)));
4221 while Present (Item) and then Item /= N loop
4222 if Nkind (Item) = N_With_Clause
4223 and then Limited_Present (Item)
4224 and then Mentioned (Pref)
4227 (Get_Msg_Id, "premature usage of incomplete type");
4236 Mark_Ghost_Clause (N);
4237 end Analyze_Use_Type;
4239 ------------------------
4240 -- Attribute_Renaming --
4241 ------------------------
4243 procedure Attribute_Renaming (N : Node_Id) is
4244 Loc : constant Source_Ptr := Sloc (N);
4245 Nam : constant Node_Id := Name (N);
4246 Spec : constant Node_Id := Specification (N);
4247 New_S : constant Entity_Id := Defining_Unit_Name (Spec);
4248 Aname : constant Name_Id := Attribute_Name (Nam);
4250 Form_Num : Nat := 0;
4251 Expr_List : List_Id := No_List;
4253 Attr_Node : Node_Id;
4254 Body_Node : Node_Id;
4255 Param_Spec : Node_Id;
4258 Generate_Definition (New_S);
4260 -- This procedure is called in the context of subprogram renaming, and
4261 -- thus the attribute must be one that is a subprogram. All of those
4262 -- have at least one formal parameter, with the exceptions of the GNAT
4263 -- attribute 'Img, which GNAT treats as renameable.
4265 if not Is_Non_Empty_List (Parameter_Specifications (Spec)) then
4266 if Aname /= Name_Img then
4268 ("subprogram renaming an attribute must have formals", N);
4273 Param_Spec := First (Parameter_Specifications (Spec));
4274 while Present (Param_Spec) loop
4275 Form_Num := Form_Num + 1;
4277 if Nkind (Parameter_Type (Param_Spec)) /= N_Access_Definition then
4278 Find_Type (Parameter_Type (Param_Spec));
4280 -- The profile of the new entity denotes the base type (s) of
4281 -- the types given in the specification. For access parameters
4282 -- there are no subtypes involved.
4284 Rewrite (Parameter_Type (Param_Spec),
4286 (Base_Type (Entity (Parameter_Type (Param_Spec))), Loc));
4289 if No (Expr_List) then
4290 Expr_List := New_List;
4293 Append_To (Expr_List,
4294 Make_Identifier (Loc,
4295 Chars => Chars (Defining_Identifier (Param_Spec))));
4297 -- The expressions in the attribute reference are not freeze
4298 -- points. Neither is the attribute as a whole, see below.
4300 Set_Must_Not_Freeze (Last (Expr_List));
4305 -- Immediate error if too many formals. Other mismatches in number or
4306 -- types of parameters are detected when we analyze the body of the
4307 -- subprogram that we construct.
4309 if Form_Num > 2 then
4310 Error_Msg_N ("too many formals for attribute", N);
4312 -- Error if the attribute reference has expressions that look like
4313 -- formal parameters.
4315 elsif Present (Expressions (Nam)) then
4316 Error_Msg_N ("illegal expressions in attribute reference", Nam);
4318 elsif Aname in Name_Compose | Name_Exponent | Name_Leading_Part |
4319 Name_Pos | Name_Round | Name_Scaling |
4322 if Nkind (N) = N_Subprogram_Renaming_Declaration
4323 and then Present (Corresponding_Formal_Spec (N))
4326 ("generic actual cannot be attribute involving universal type",
4330 ("attribute involving a universal type cannot be renamed",
4335 -- Rewrite attribute node to have a list of expressions corresponding to
4336 -- the subprogram formals. A renaming declaration is not a freeze point,
4337 -- and the analysis of the attribute reference should not freeze the
4338 -- type of the prefix. We use the original node in the renaming so that
4339 -- its source location is preserved, and checks on stream attributes are
4340 -- properly applied.
4342 Attr_Node := Relocate_Node (Nam);
4343 Set_Expressions (Attr_Node, Expr_List);
4345 Set_Must_Not_Freeze (Attr_Node);
4346 Set_Must_Not_Freeze (Prefix (Nam));
4348 -- Case of renaming a function
4350 if Nkind (Spec) = N_Function_Specification then
4351 if Is_Procedure_Attribute_Name (Aname) then
4352 Error_Msg_N ("attribute can only be renamed as procedure", Nam);
4356 Find_Type (Result_Definition (Spec));
4357 Rewrite (Result_Definition (Spec),
4359 (Base_Type (Entity (Result_Definition (Spec))), Loc));
4362 Make_Subprogram_Body (Loc,
4363 Specification => Spec,
4364 Declarations => New_List,
4365 Handled_Statement_Sequence =>
4366 Make_Handled_Sequence_Of_Statements (Loc,
4367 Statements => New_List (
4368 Make_Simple_Return_Statement (Loc,
4369 Expression => Attr_Node))));
4371 -- Case of renaming a procedure
4374 if not Is_Procedure_Attribute_Name (Aname) then
4375 Error_Msg_N ("attribute can only be renamed as function", Nam);
4380 Make_Subprogram_Body (Loc,
4381 Specification => Spec,
4382 Declarations => New_List,
4383 Handled_Statement_Sequence =>
4384 Make_Handled_Sequence_Of_Statements (Loc,
4385 Statements => New_List (Attr_Node)));
4388 -- Signal the ABE mechanism that the generated subprogram body has not
4389 -- ABE ramifications.
4391 Set_Was_Attribute_Reference (Body_Node);
4393 -- In case of tagged types we add the body of the generated function to
4394 -- the freezing actions of the type (because in the general case such
4395 -- type is still not frozen). We exclude from this processing generic
4396 -- formal subprograms found in instantiations.
4398 -- We must exclude restricted run-time libraries because
4399 -- entity AST_Handler is defined in package System.Aux_Dec which is not
4400 -- available in those platforms. Note that we cannot use the function
4401 -- Restricted_Profile (instead of Configurable_Run_Time_Mode) because
4402 -- the ZFP run-time library is not defined as a profile, and we do not
4403 -- want to deal with AST_Handler in ZFP mode.
4405 if not Configurable_Run_Time_Mode
4406 and then not Present (Corresponding_Formal_Spec (N))
4407 and then Etype (Nam) /= RTE (RE_AST_Handler)
4410 P : constant Node_Id := Prefix (Nam);
4413 -- The prefix of 'Img is an object that is evaluated for each call
4414 -- of the function that renames it.
4416 if Aname = Name_Img then
4417 Preanalyze_And_Resolve (P);
4419 -- For all other attribute renamings, the prefix is a subtype
4425 -- If the target type is not yet frozen, add the body to the
4426 -- actions to be elaborated at freeze time.
4428 if Is_Tagged_Type (Etype (P))
4429 and then In_Open_Scopes (Scope (Etype (P)))
4431 Ensure_Freeze_Node (Etype (P));
4432 Append_Freeze_Action (Etype (P), Body_Node);
4434 Rewrite (N, Body_Node);
4436 Set_Etype (New_S, Base_Type (Etype (New_S)));
4440 -- Generic formal subprograms or AST_Handler renaming
4443 Rewrite (N, Body_Node);
4445 Set_Etype (New_S, Base_Type (Etype (New_S)));
4448 if Is_Compilation_Unit (New_S) then
4450 ("a library unit can only rename another library unit", N);
4453 -- We suppress elaboration warnings for the resulting entity, since
4454 -- clearly they are not needed, and more particularly, in the case
4455 -- of a generic formal subprogram, the resulting entity can appear
4456 -- after the instantiation itself, and thus look like a bogus case
4457 -- of access before elaboration.
4459 if Legacy_Elaboration_Checks then
4460 Set_Suppress_Elaboration_Warnings (New_S);
4462 end Attribute_Renaming;
4464 ----------------------
4465 -- Chain_Use_Clause --
4466 ----------------------
4468 procedure Chain_Use_Clause (N : Node_Id) is
4469 Level : Int := Scope_Stack.Last;
4475 if not Is_Compilation_Unit (Current_Scope)
4476 or else not Is_Child_Unit (Current_Scope)
4480 -- Common case for compilation unit
4482 elsif Defining_Entity (Parent (N)) = Current_Scope then
4486 -- If declaration appears in some other scope, it must be in some
4487 -- parent unit when compiling a child.
4489 Pack := Defining_Entity (Parent (N));
4491 if not In_Open_Scopes (Pack) then
4494 -- If the use clause appears in an ancestor and we are in the
4495 -- private part of the immediate parent, the use clauses are
4496 -- already installed.
4498 elsif Pack /= Scope (Current_Scope)
4499 and then In_Private_Part (Scope (Current_Scope))
4504 -- Find entry for parent unit in scope stack
4506 while Scope_Stack.Table (Level).Entity /= Pack loop
4512 Set_Next_Use_Clause (N,
4513 Scope_Stack.Table (Level).First_Use_Clause);
4514 Scope_Stack.Table (Level).First_Use_Clause := N;
4515 end Chain_Use_Clause;
4517 ---------------------------
4518 -- Check_Frozen_Renaming --
4519 ---------------------------
4521 procedure Check_Frozen_Renaming (N : Node_Id; Subp : Entity_Id) is
4526 if Is_Frozen (Subp) and then not Has_Completion (Subp) then
4529 (Parent (Declaration_Node (Subp)), Defining_Entity (N));
4531 if Is_Entity_Name (Name (N)) then
4532 Old_S := Entity (Name (N));
4534 if not Is_Frozen (Old_S)
4535 and then Operating_Mode /= Check_Semantics
4537 Append_Freeze_Action (Old_S, B_Node);
4539 Insert_After (N, B_Node);
4543 if Is_Intrinsic_Subprogram (Old_S)
4544 and then not In_Instance
4545 and then not Relaxed_RM_Semantics
4548 ("subprogram used in renaming_as_body cannot be intrinsic",
4553 Insert_After (N, B_Node);
4557 end Check_Frozen_Renaming;
4559 -------------------------------
4560 -- Set_Entity_Or_Discriminal --
4561 -------------------------------
4563 procedure Set_Entity_Or_Discriminal (N : Node_Id; E : Entity_Id) is
4567 -- If the entity is not a discriminant, or else expansion is disabled,
4568 -- simply set the entity.
4570 if not In_Spec_Expression
4571 or else Ekind (E) /= E_Discriminant
4572 or else Inside_A_Generic
4574 Set_Entity_With_Checks (N, E);
4576 -- The replacement of a discriminant by the corresponding discriminal
4577 -- is not done for a task discriminant that appears in a default
4578 -- expression of an entry parameter. See Exp_Ch2.Expand_Discriminant
4579 -- for details on their handling.
4581 elsif Is_Concurrent_Type (Scope (E)) then
4584 and then Nkind (P) not in
4585 N_Parameter_Specification | N_Component_Declaration
4591 and then Nkind (P) = N_Parameter_Specification
4596 Set_Entity (N, Discriminal (E));
4599 -- Otherwise, this is a discriminant in a context in which
4600 -- it is a reference to the corresponding parameter of the
4601 -- init proc for the enclosing type.
4604 Set_Entity (N, Discriminal (E));
4606 end Set_Entity_Or_Discriminal;
4608 -----------------------------------
4609 -- Check_In_Previous_With_Clause --
4610 -----------------------------------
4612 procedure Check_In_Previous_With_Clause
4616 Pack : constant Entity_Id := Entity (Original_Node (Nam));
4621 Item := First (Context_Items (Parent (N)));
4622 while Present (Item) and then Item /= N loop
4623 if Nkind (Item) = N_With_Clause
4625 -- Protect the frontend against previous critical errors
4627 and then Nkind (Name (Item)) /= N_Selected_Component
4628 and then Entity (Name (Item)) = Pack
4632 -- Find root library unit in with_clause
4634 while Nkind (Par) = N_Expanded_Name loop
4635 Par := Prefix (Par);
4638 if Is_Child_Unit (Entity (Original_Node (Par))) then
4639 Error_Msg_NE ("& is not directly visible", Par, Entity (Par));
4648 -- On exit, package is not mentioned in a previous with_clause.
4649 -- Check if its prefix is.
4651 if Nkind (Nam) = N_Expanded_Name then
4652 Check_In_Previous_With_Clause (N, Prefix (Nam));
4654 elsif Pack /= Any_Id then
4655 Error_Msg_NE ("& is not visible", Nam, Pack);
4657 end Check_In_Previous_With_Clause;
4659 ---------------------------------
4660 -- Check_Library_Unit_Renaming --
4661 ---------------------------------
4663 procedure Check_Library_Unit_Renaming (N : Node_Id; Old_E : Entity_Id) is
4667 if Nkind (Parent (N)) /= N_Compilation_Unit then
4670 -- Check for library unit. Note that we used to check for the scope
4671 -- being Standard here, but that was wrong for Standard itself.
4673 elsif not Is_Compilation_Unit (Old_E)
4674 and then not Is_Child_Unit (Old_E)
4676 Error_Msg_N ("renamed unit must be a library unit", Name (N));
4678 -- Entities defined in Standard (operators and boolean literals) cannot
4679 -- be renamed as library units.
4681 elsif Scope (Old_E) = Standard_Standard
4682 and then Sloc (Old_E) = Standard_Location
4684 Error_Msg_N ("renamed unit must be a library unit", Name (N));
4686 elsif Present (Parent_Spec (N))
4687 and then Nkind (Unit (Parent_Spec (N))) = N_Generic_Package_Declaration
4688 and then not Is_Child_Unit (Old_E)
4691 ("renamed unit must be a child unit of generic parent", Name (N));
4693 elsif Nkind (N) in N_Generic_Renaming_Declaration
4694 and then Nkind (Name (N)) = N_Expanded_Name
4695 and then Is_Generic_Instance (Entity (Prefix (Name (N))))
4696 and then Is_Generic_Unit (Old_E)
4699 ("renamed generic unit must be a library unit", Name (N));
4701 elsif Is_Package_Or_Generic_Package (Old_E) then
4703 -- Inherit categorization flags
4705 New_E := Defining_Entity (N);
4706 Set_Is_Pure (New_E, Is_Pure (Old_E));
4707 Set_Is_Preelaborated (New_E, Is_Preelaborated (Old_E));
4708 Set_Is_Remote_Call_Interface (New_E,
4709 Is_Remote_Call_Interface (Old_E));
4710 Set_Is_Remote_Types (New_E, Is_Remote_Types (Old_E));
4711 Set_Is_Shared_Passive (New_E, Is_Shared_Passive (Old_E));
4713 end Check_Library_Unit_Renaming;
4715 ------------------------
4716 -- Enclosing_Instance --
4717 ------------------------
4719 function Enclosing_Instance return Entity_Id is
4723 if not Is_Generic_Instance (Current_Scope) then
4727 S := Scope (Current_Scope);
4728 while S /= Standard_Standard loop
4729 if Is_Generic_Instance (S) then
4737 end Enclosing_Instance;
4743 procedure End_Scope is
4749 Id := First_Entity (Current_Scope);
4750 while Present (Id) loop
4751 -- An entity in the current scope is not necessarily the first one
4752 -- on its homonym chain. Find its predecessor if any,
4753 -- If it is an internal entity, it will not be in the visibility
4754 -- chain altogether, and there is nothing to unchain.
4756 if Id /= Current_Entity (Id) then
4757 Prev := Current_Entity (Id);
4758 while Present (Prev)
4759 and then Present (Homonym (Prev))
4760 and then Homonym (Prev) /= Id
4762 Prev := Homonym (Prev);
4765 -- Skip to end of loop if Id is not in the visibility chain
4767 if No (Prev) or else Homonym (Prev) /= Id then
4775 Set_Is_Immediately_Visible (Id, False);
4777 Outer := Homonym (Id);
4778 while Present (Outer) and then Scope (Outer) = Current_Scope loop
4779 Outer := Homonym (Outer);
4782 -- Reset homonym link of other entities, but do not modify link
4783 -- between entities in current scope, so that the back-end can have
4784 -- a proper count of local overloadings.
4787 Set_Name_Entity_Id (Chars (Id), Outer);
4789 elsif Scope (Prev) /= Scope (Id) then
4790 Set_Homonym (Prev, Outer);
4797 -- If the scope generated freeze actions, place them before the
4798 -- current declaration and analyze them. Type declarations and
4799 -- the bodies of initialization procedures can generate such nodes.
4800 -- We follow the parent chain until we reach a list node, which is
4801 -- the enclosing list of declarations. If the list appears within
4802 -- a protected definition, move freeze nodes outside the protected
4806 (Scope_Stack.Table (Scope_Stack.Last).Pending_Freeze_Actions)
4810 L : constant List_Id := Scope_Stack.Table
4811 (Scope_Stack.Last).Pending_Freeze_Actions;
4814 if Is_Itype (Current_Scope) then
4815 Decl := Associated_Node_For_Itype (Current_Scope);
4817 Decl := Parent (Current_Scope);
4822 while not (Is_List_Member (Decl))
4823 or else Nkind (Parent (Decl)) in N_Protected_Definition
4826 Decl := Parent (Decl);
4829 Insert_List_Before_And_Analyze (Decl, L);
4837 ---------------------
4838 -- End_Use_Clauses --
4839 ---------------------
4841 procedure End_Use_Clauses (Clause : Node_Id) is
4845 -- Remove use_type_clauses first, because they affect the visibility of
4846 -- operators in subsequent used packages.
4849 while Present (U) loop
4850 if Nkind (U) = N_Use_Type_Clause then
4854 Next_Use_Clause (U);
4858 while Present (U) loop
4859 if Nkind (U) = N_Use_Package_Clause then
4860 End_Use_Package (U);
4863 Next_Use_Clause (U);
4865 end End_Use_Clauses;
4867 ---------------------
4868 -- End_Use_Package --
4869 ---------------------
4871 procedure End_Use_Package (N : Node_Id) is
4873 Pack_Name : Node_Id;
4877 function Is_Primitive_Operator_In_Use
4879 F : Entity_Id) return Boolean;
4880 -- Check whether Op is a primitive operator of a use-visible type
4882 ----------------------------------
4883 -- Is_Primitive_Operator_In_Use --
4884 ----------------------------------
4886 function Is_Primitive_Operator_In_Use
4888 F : Entity_Id) return Boolean
4890 T : constant Entity_Id := Base_Type (Etype (F));
4892 return In_Use (T) and then Scope (T) = Scope (Op);
4893 end Is_Primitive_Operator_In_Use;
4895 -- Start of processing for End_Use_Package
4898 Pack_Name := Name (N);
4900 -- Test that Pack_Name actually denotes a package before processing
4902 if Is_Entity_Name (Pack_Name)
4903 and then Ekind (Entity (Pack_Name)) = E_Package
4905 Pack := Entity (Pack_Name);
4907 if In_Open_Scopes (Pack) then
4910 elsif not Redundant_Use (Pack_Name) then
4911 Set_In_Use (Pack, False);
4912 Set_Current_Use_Clause (Pack, Empty);
4914 Id := First_Entity (Pack);
4915 while Present (Id) loop
4917 -- Preserve use-visibility of operators that are primitive
4918 -- operators of a type that is use-visible through an active
4921 if Nkind (Id) = N_Defining_Operator_Symbol
4923 (Is_Primitive_Operator_In_Use (Id, First_Formal (Id))
4925 (Present (Next_Formal (First_Formal (Id)))
4927 Is_Primitive_Operator_In_Use
4928 (Id, Next_Formal (First_Formal (Id)))))
4932 Set_Is_Potentially_Use_Visible (Id, False);
4935 if Is_Private_Type (Id)
4936 and then Present (Full_View (Id))
4938 Set_Is_Potentially_Use_Visible (Full_View (Id), False);
4944 if Present (Renamed_Object (Pack)) then
4945 Set_In_Use (Renamed_Object (Pack), False);
4946 Set_Current_Use_Clause (Renamed_Object (Pack), Empty);
4949 if Chars (Pack) = Name_System
4950 and then Scope (Pack) = Standard_Standard
4951 and then Present_System_Aux
4953 Id := First_Entity (System_Aux_Id);
4954 while Present (Id) loop
4955 Set_Is_Potentially_Use_Visible (Id, False);
4957 if Is_Private_Type (Id)
4958 and then Present (Full_View (Id))
4960 Set_Is_Potentially_Use_Visible (Full_View (Id), False);
4966 Set_In_Use (System_Aux_Id, False);
4969 Set_Redundant_Use (Pack_Name, False);
4973 if Present (Hidden_By_Use_Clause (N)) then
4974 Elmt := First_Elmt (Hidden_By_Use_Clause (N));
4975 while Present (Elmt) loop
4977 E : constant Entity_Id := Node (Elmt);
4980 -- Reset either Use_Visibility or Direct_Visibility, depending
4981 -- on how the entity was hidden by the use clause.
4983 if In_Use (Scope (E))
4984 and then Used_As_Generic_Actual (Scope (E))
4986 Set_Is_Potentially_Use_Visible (Node (Elmt));
4988 Set_Is_Immediately_Visible (Node (Elmt));
4995 Set_Hidden_By_Use_Clause (N, No_Elist);
4997 end End_Use_Package;
5003 procedure End_Use_Type (N : Node_Id) is
5008 -- Start of processing for End_Use_Type
5011 Id := Subtype_Mark (N);
5013 -- A call to Rtsfind may occur while analyzing a use_type_clause, in
5014 -- which case the type marks are not resolved yet, so guard against that
5017 if Is_Entity_Name (Id) and then Present (Entity (Id)) then
5020 if T = Any_Type or else From_Limited_With (T) then
5023 -- Note that the use_type_clause may mention a subtype of the type
5024 -- whose primitive operations have been made visible. Here as
5025 -- elsewhere, it is the base type that matters for visibility.
5027 elsif In_Open_Scopes (Scope (Base_Type (T))) then
5030 elsif not Redundant_Use (Id) then
5031 Set_In_Use (T, False);
5032 Set_In_Use (Base_Type (T), False);
5033 Set_Current_Use_Clause (T, Empty);
5034 Set_Current_Use_Clause (Base_Type (T), Empty);
5036 -- See Use_One_Type for the rationale. This is a bit on the naive
5037 -- side, but should be good enough in practice.
5039 if Is_Tagged_Type (T) then
5040 Set_In_Use (Class_Wide_Type (T), False);
5045 if Is_Empty_Elmt_List (Used_Operations (N)) then
5049 Elmt := First_Elmt (Used_Operations (N));
5050 while Present (Elmt) loop
5051 Set_Is_Potentially_Use_Visible (Node (Elmt), False);
5057 --------------------
5058 -- Entity_Of_Unit --
5059 --------------------
5061 function Entity_Of_Unit (U : Node_Id) return Entity_Id is
5063 if Nkind (U) = N_Package_Instantiation and then Analyzed (U) then
5064 return Defining_Entity (Instance_Spec (U));
5066 return Defining_Entity (U);
5070 ----------------------
5071 -- Find_Direct_Name --
5072 ----------------------
5074 procedure Find_Direct_Name (N : Node_Id) is
5079 Homonyms : Entity_Id;
5080 -- Saves start of homonym chain
5082 Inst : Entity_Id := Empty;
5083 -- Enclosing instance, if any
5085 Nvis_Entity : Boolean;
5086 -- Set True to indicate that there is at least one entity on the homonym
5087 -- chain which, while not visible, is visible enough from the user point
5088 -- of view to warrant an error message of "not visible" rather than
5091 Nvis_Is_Private_Subprg : Boolean := False;
5092 -- Ada 2005 (AI-262): Set True to indicate that a form of Beaujolais
5093 -- effect concerning library subprograms has been detected. Used to
5094 -- generate the precise error message.
5096 function From_Actual_Package (E : Entity_Id) return Boolean;
5097 -- Returns true if the entity is an actual for a package that is itself
5098 -- an actual for a formal package of the current instance. Such an
5099 -- entity requires special handling because it may be use-visible but
5100 -- hides directly visible entities defined outside the instance, because
5101 -- the corresponding formal did so in the generic.
5103 function Is_Actual_Parameter return Boolean;
5104 -- This function checks if the node N is an identifier that is an actual
5105 -- parameter of a procedure call. If so it returns True, otherwise it
5106 -- return False. The reason for this check is that at this stage we do
5107 -- not know what procedure is being called if the procedure might be
5108 -- overloaded, so it is premature to go setting referenced flags or
5109 -- making calls to Generate_Reference. We will wait till Resolve_Actuals
5110 -- for that processing.
5111 -- Note: there is a similar routine Sem_Util.Is_Actual_Parameter, but
5112 -- it works for both function and procedure calls, while here we are
5113 -- only concerned with procedure calls (and with entry calls as well,
5114 -- but they are parsed as procedure calls and only later rewritten to
5117 function Known_But_Invisible (E : Entity_Id) return Boolean;
5118 -- This function determines whether a reference to the entity E, which
5119 -- is not visible, can reasonably be considered to be known to the
5120 -- writer of the reference. This is a heuristic test, used only for
5121 -- the purposes of figuring out whether we prefer to complain that an
5122 -- entity is undefined or invisible (and identify the declaration of
5123 -- the invisible entity in the latter case). The point here is that we
5124 -- don't want to complain that something is invisible and then point to
5125 -- something entirely mysterious to the writer.
5127 procedure Nvis_Messages;
5128 -- Called if there are no visible entries for N, but there is at least
5129 -- one non-directly visible, or hidden declaration. This procedure
5130 -- outputs an appropriate set of error messages.
5132 procedure Undefined (Nvis : Boolean);
5133 -- This function is called if the current node has no corresponding
5134 -- visible entity or entities. The value set in Msg indicates whether
5135 -- an error message was generated (multiple error messages for the
5136 -- same variable are generally suppressed, see body for details).
5137 -- Msg is True if an error message was generated, False if not. This
5138 -- value is used by the caller to determine whether or not to output
5139 -- additional messages where appropriate. The parameter is set False
5140 -- to get the message "X is undefined", and True to get the message
5141 -- "X is not visible".
5143 -------------------------
5144 -- From_Actual_Package --
5145 -------------------------
5147 function From_Actual_Package (E : Entity_Id) return Boolean is
5148 Scop : constant Entity_Id := Scope (E);
5149 -- Declared scope of candidate entity
5151 function Declared_In_Actual (Pack : Entity_Id) return Boolean;
5152 -- Recursive function that does the work and examines actuals of
5153 -- actual packages of current instance.
5155 ------------------------
5156 -- Declared_In_Actual --
5157 ------------------------
5159 function Declared_In_Actual (Pack : Entity_Id) return Boolean is
5163 if No (Associated_Formal_Package (Pack)) then
5167 Act := First_Entity (Pack);
5168 while Present (Act) loop
5169 if Renamed_Object (Pack) = Scop then
5172 -- Check for end of list of actuals
5174 elsif Ekind (Act) = E_Package
5175 and then Renamed_Object (Act) = Pack
5179 elsif Ekind (Act) = E_Package
5180 and then Declared_In_Actual (Act)
5190 end Declared_In_Actual;
5196 -- Start of processing for From_Actual_Package
5199 if not In_Instance then
5203 Inst := Current_Scope;
5204 while Present (Inst)
5205 and then Ekind (Inst) /= E_Package
5206 and then not Is_Generic_Instance (Inst)
5208 Inst := Scope (Inst);
5215 Act := First_Entity (Inst);
5216 while Present (Act) loop
5217 if Ekind (Act) = E_Package
5218 and then Declared_In_Actual (Act)
5228 end From_Actual_Package;
5230 -------------------------
5231 -- Is_Actual_Parameter --
5232 -------------------------
5234 function Is_Actual_Parameter return Boolean is
5236 if Nkind (N) = N_Identifier then
5237 case Nkind (Parent (N)) is
5238 when N_Procedure_Call_Statement =>
5239 return Is_List_Member (N)
5240 and then List_Containing (N) =
5241 Parameter_Associations (Parent (N));
5243 when N_Parameter_Association =>
5244 return N = Explicit_Actual_Parameter (Parent (N))
5245 and then Nkind (Parent (Parent (N))) =
5246 N_Procedure_Call_Statement;
5254 end Is_Actual_Parameter;
5256 -------------------------
5257 -- Known_But_Invisible --
5258 -------------------------
5260 function Known_But_Invisible (E : Entity_Id) return Boolean is
5261 Fname : File_Name_Type;
5264 -- Entities in Standard are always considered to be known
5266 if Sloc (E) <= Standard_Location then
5269 -- An entity that does not come from source is always considered
5270 -- to be unknown, since it is an artifact of code expansion.
5272 elsif not Comes_From_Source (E) then
5275 -- In gnat internal mode, we consider all entities known. The
5276 -- historical reason behind this discrepancy is not known??? But the
5277 -- only effect is to modify the error message given, so it is not
5278 -- critical. Since it only affects the exact wording of error
5279 -- messages in illegal programs, we do not mention this as an
5280 -- effect of -gnatg, since it is not a language modification.
5282 elsif GNAT_Mode then
5286 -- Here we have an entity that is not from package Standard, and
5287 -- which comes from Source. See if it comes from an internal file.
5289 Fname := Unit_File_Name (Get_Source_Unit (E));
5291 -- Case of from internal file
5293 if In_Internal_Unit (E) then
5295 -- Private part entities in internal files are never considered
5296 -- to be known to the writer of normal application code.
5298 if Is_Hidden (E) then
5302 -- Entities from System packages other than System and
5303 -- System.Storage_Elements are not considered to be known.
5304 -- System.Auxxxx files are also considered known to the user.
5306 -- Should refine this at some point to generally distinguish
5307 -- between known and unknown internal files ???
5309 Get_Name_String (Fname);
5314 Name_Buffer (1 .. 2) /= "s-"
5316 Name_Buffer (3 .. 8) = "stoele"
5318 Name_Buffer (3 .. 5) = "aux";
5320 -- If not an internal file, then entity is definitely known, even if
5321 -- it is in a private part (the message generated will note that it
5322 -- is in a private part).
5327 end Known_But_Invisible;
5333 procedure Nvis_Messages is
5334 Comp_Unit : Node_Id;
5336 Found : Boolean := False;
5337 Hidden : Boolean := False;
5341 -- Ada 2005 (AI-262): Generate a precise error concerning the
5342 -- Beaujolais effect that was previously detected
5344 if Nvis_Is_Private_Subprg then
5346 pragma Assert (Nkind (E2) = N_Defining_Identifier
5347 and then Ekind (E2) = E_Function
5348 and then Scope (E2) = Standard_Standard
5349 and then Has_Private_With (E2));
5351 -- Find the sloc corresponding to the private with'ed unit
5353 Comp_Unit := Cunit (Current_Sem_Unit);
5354 Error_Msg_Sloc := No_Location;
5356 Item := First (Context_Items (Comp_Unit));
5357 while Present (Item) loop
5358 if Nkind (Item) = N_With_Clause
5359 and then Private_Present (Item)
5360 and then Entity (Name (Item)) = E2
5362 Error_Msg_Sloc := Sloc (Item);
5369 pragma Assert (Error_Msg_Sloc /= No_Location);
5371 Error_Msg_N ("(Ada 2005): hidden by private with clause #", N);
5375 Undefined (Nvis => True);
5379 -- First loop does hidden declarations
5382 while Present (Ent) loop
5383 if Is_Potentially_Use_Visible (Ent) then
5385 Error_Msg_N -- CODEFIX
5386 ("multiple use clauses cause hiding!", N);
5390 Error_Msg_Sloc := Sloc (Ent);
5391 Error_Msg_N -- CODEFIX
5392 ("hidden declaration#!", N);
5395 Ent := Homonym (Ent);
5398 -- If we found hidden declarations, then that's enough, don't
5399 -- bother looking for non-visible declarations as well.
5405 -- Second loop does non-directly visible declarations
5408 while Present (Ent) loop
5409 if not Is_Potentially_Use_Visible (Ent) then
5411 -- Do not bother the user with unknown entities
5413 if not Known_But_Invisible (Ent) then
5417 Error_Msg_Sloc := Sloc (Ent);
5419 -- Output message noting that there is a non-visible
5420 -- declaration, distinguishing the private part case.
5422 if Is_Hidden (Ent) then
5423 Error_Msg_N ("non-visible (private) declaration#!", N);
5425 -- If the entity is declared in a generic package, it
5426 -- cannot be visible, so there is no point in adding it
5427 -- to the list of candidates if another homograph from a
5428 -- non-generic package has been seen.
5430 elsif Ekind (Scope (Ent)) = E_Generic_Package
5436 Error_Msg_N -- CODEFIX
5437 ("non-visible declaration#!", N);
5439 if Ekind (Scope (Ent)) /= E_Generic_Package then
5443 if Is_Compilation_Unit (Ent)
5445 Nkind (Parent (Parent (N))) = N_Use_Package_Clause
5447 Error_Msg_Qual_Level := 99;
5448 Error_Msg_NE -- CODEFIX
5449 ("\\missing `WITH &;`", N, Ent);
5450 Error_Msg_Qual_Level := 0;
5453 if Ekind (Ent) = E_Discriminant
5454 and then Present (Corresponding_Discriminant (Ent))
5455 and then Scope (Corresponding_Discriminant (Ent)) =
5459 ("inherited discriminant not allowed here" &
5460 " (RM 3.8 (12), 3.8.1 (6))!", N);
5464 -- Set entity and its containing package as referenced. We
5465 -- can't be sure of this, but this seems a better choice
5466 -- to avoid unused entity messages.
5468 if Comes_From_Source (Ent) then
5469 Set_Referenced (Ent);
5470 Set_Referenced (Cunit_Entity (Get_Source_Unit (Ent)));
5475 Ent := Homonym (Ent);
5484 procedure Undefined (Nvis : Boolean) is
5485 Emsg : Error_Msg_Id;
5488 -- We should never find an undefined internal name. If we do, then
5489 -- see if we have previous errors. If so, ignore on the grounds that
5490 -- it is probably a cascaded message (e.g. a block label from a badly
5491 -- formed block). If no previous errors, then we have a real internal
5492 -- error of some kind so raise an exception.
5494 if Is_Internal_Name (Chars (N)) then
5495 if Total_Errors_Detected /= 0 then
5498 raise Program_Error;
5502 -- A very specialized error check, if the undefined variable is
5503 -- a case tag, and the case type is an enumeration type, check
5504 -- for a possible misspelling, and if so, modify the identifier
5506 -- Named aggregate should also be handled similarly ???
5508 if Nkind (N) = N_Identifier
5509 and then Nkind (Parent (N)) = N_Case_Statement_Alternative
5512 Case_Stm : constant Node_Id := Parent (Parent (N));
5513 Case_Typ : constant Entity_Id := Etype (Expression (Case_Stm));
5518 if Is_Enumeration_Type (Case_Typ)
5519 and then not Is_Standard_Character_Type (Case_Typ)
5521 Lit := First_Literal (Case_Typ);
5522 Get_Name_String (Chars (Lit));
5524 if Chars (Lit) /= Chars (N)
5525 and then Is_Bad_Spelling_Of (Chars (N), Chars (Lit))
5527 Error_Msg_Node_2 := Lit;
5528 Error_Msg_N -- CODEFIX
5529 ("& is undefined, assume misspelling of &", N);
5530 Rewrite (N, New_Occurrence_Of (Lit, Sloc (N)));
5539 -- Normal processing
5541 Set_Entity (N, Any_Id);
5542 Set_Etype (N, Any_Type);
5544 -- We use the table Urefs to keep track of entities for which we
5545 -- have issued errors for undefined references. Multiple errors
5546 -- for a single name are normally suppressed, however we modify
5547 -- the error message to alert the programmer to this effect.
5549 for J in Urefs.First .. Urefs.Last loop
5550 if Chars (N) = Chars (Urefs.Table (J).Node) then
5551 if Urefs.Table (J).Err /= No_Error_Msg
5552 and then Sloc (N) /= Urefs.Table (J).Loc
5554 Error_Msg_Node_1 := Urefs.Table (J).Node;
5556 if Urefs.Table (J).Nvis then
5557 Change_Error_Text (Urefs.Table (J).Err,
5558 "& is not visible (more references follow)");
5560 Change_Error_Text (Urefs.Table (J).Err,
5561 "& is undefined (more references follow)");
5564 Urefs.Table (J).Err := No_Error_Msg;
5567 -- Although we will set Msg False, and thus suppress the
5568 -- message, we also set Error_Posted True, to avoid any
5569 -- cascaded messages resulting from the undefined reference.
5572 Set_Error_Posted (N);
5577 -- If entry not found, this is first undefined occurrence
5580 Error_Msg_N ("& is not visible!", N);
5584 Error_Msg_N ("& is undefined!", N);
5587 -- A very bizarre special check, if the undefined identifier
5588 -- is Put or Put_Line, then add a special error message (since
5589 -- this is a very common error for beginners to make).
5591 if Chars (N) in Name_Put | Name_Put_Line then
5592 Error_Msg_N -- CODEFIX
5593 ("\\possible missing `WITH Ada.Text_'I'O; " &
5594 "USE Ada.Text_'I'O`!", N);
5596 -- Another special check if N is the prefix of a selected
5597 -- component which is a known unit: add message complaining
5598 -- about missing with for this unit.
5600 elsif Nkind (Parent (N)) = N_Selected_Component
5601 and then N = Prefix (Parent (N))
5602 and then Is_Known_Unit (Parent (N))
5605 P : Node_Id := Parent (N);
5607 Error_Msg_Name_1 := Chars (N);
5608 Error_Msg_Name_2 := Chars (Selector_Name (P));
5610 if Nkind (Parent (P)) = N_Selected_Component
5611 and then Is_Known_Unit (Parent (P))
5614 Error_Msg_Name_3 := Chars (Selector_Name (P));
5615 Error_Msg_N -- CODEFIX
5616 ("\\missing `WITH %.%.%;`", N);
5619 Error_Msg_N -- CODEFIX
5620 ("\\missing `WITH %.%;`", N);
5625 -- Now check for possible misspellings
5629 Ematch : Entity_Id := Empty;
5631 for Nam in First_Name_Id .. Last_Name_Id loop
5632 E := Get_Name_Entity_Id (Nam);
5635 and then (Is_Immediately_Visible (E)
5637 Is_Potentially_Use_Visible (E))
5639 if Is_Bad_Spelling_Of (Chars (N), Nam) then
5646 if Present (Ematch) then
5647 Error_Msg_NE -- CODEFIX
5648 ("\possible misspelling of&", N, Ematch);
5653 -- Make entry in undefined references table unless the full errors
5654 -- switch is set, in which case by refraining from generating the
5655 -- table entry we guarantee that we get an error message for every
5656 -- undefined reference. The entry is not added if we are ignoring
5659 if not All_Errors_Mode
5660 and then Ignore_Errors_Enable = 0
5661 and then not Get_Ignore_Errors
5675 Nested_Inst : Entity_Id := Empty;
5676 -- The entity of a nested instance which appears within Inst (if any)
5678 -- Start of processing for Find_Direct_Name
5681 -- If the entity pointer is already set, this is an internal node, or
5682 -- a node that is analyzed more than once, after a tree modification.
5683 -- In such a case there is no resolution to perform, just set the type.
5685 if Present (Entity (N)) then
5686 if Is_Type (Entity (N)) then
5687 Set_Etype (N, Entity (N));
5689 -- The exception to this general rule are constants associated with
5690 -- discriminals of protected types because for each protected op
5691 -- a new set of discriminals is internally created by the frontend
5692 -- (see Exp_Ch9.Set_Discriminals), and the current decoration of the
5693 -- entity pointer may have been set as part of a preanalysis, where
5694 -- discriminals still reference the first subprogram or entry to be
5695 -- expanded (see Expand_Protected_Body_Declarations).
5698 and then Ekind (Entity (N)) = E_Constant
5699 and then Present (Discriminal_Link (Entity (N)))
5700 and then Is_Protected_Type (Scope (Discriminal_Link (Entity (N))))
5706 Entyp : constant Entity_Id := Etype (Entity (N));
5709 -- One special case here. If the Etype field is already set,
5710 -- and references the packed array type corresponding to the
5711 -- etype of the referenced entity, then leave it alone. This
5712 -- happens for trees generated from Exp_Pakd, where expressions
5713 -- can be deliberately "mis-typed" to the packed array type.
5715 if Is_Packed_Array (Entyp)
5716 and then Present (Etype (N))
5717 and then Etype (N) = Packed_Array_Impl_Type (Entyp)
5721 -- If not that special case, then just reset the Etype
5724 Set_Etype (N, Etype (Entity (N)));
5729 -- Although the marking of use clauses happens at the end of
5730 -- Find_Direct_Name, a certain case where a generic actual satisfies
5731 -- a use clause must be checked here due to how the generic machinery
5732 -- handles the analysis of said actuals.
5735 and then Nkind (Parent (N)) = N_Generic_Association
5737 Mark_Use_Clauses (Entity (N));
5745 -- Preserve relevant elaboration-related attributes of the context which
5746 -- are no longer available or very expensive to recompute once analysis,
5747 -- resolution, and expansion are over.
5749 if Nkind (N) = N_Identifier then
5750 Mark_Elaboration_Attributes
5757 -- Here if Entity pointer was not set, we need full visibility analysis
5758 -- First we generate debugging output if the debug E flag is set.
5760 if Debug_Flag_E then
5761 Write_Str ("Looking for ");
5762 Write_Name (Chars (N));
5766 Homonyms := Current_Entity (N);
5767 Nvis_Entity := False;
5770 while Present (E) loop
5772 -- If entity is immediately visible or potentially use visible, then
5773 -- process the entity and we are done.
5775 if Is_Immediately_Visible (E) then
5776 goto Immediately_Visible_Entity;
5778 elsif Is_Potentially_Use_Visible (E) then
5779 goto Potentially_Use_Visible_Entity;
5781 -- Note if a known but invisible entity encountered
5783 elsif Known_But_Invisible (E) then
5784 Nvis_Entity := True;
5787 -- Move to next entity in chain and continue search
5792 -- If no entries on homonym chain that were potentially visible,
5793 -- and no entities reasonably considered as non-visible, then
5794 -- we have a plain undefined reference, with no additional
5795 -- explanation required.
5797 if not Nvis_Entity then
5798 Undefined (Nvis => False);
5800 -- Otherwise there is at least one entry on the homonym chain that
5801 -- is reasonably considered as being known and non-visible.
5809 -- Processing for a potentially use visible entry found. We must search
5810 -- the rest of the homonym chain for two reasons. First, if there is a
5811 -- directly visible entry, then none of the potentially use-visible
5812 -- entities are directly visible (RM 8.4(10)). Second, we need to check
5813 -- for the case of multiple potentially use-visible entries hiding one
5814 -- another and as a result being non-directly visible (RM 8.4(11)).
5816 <<Potentially_Use_Visible_Entity>> declare
5817 Only_One_Visible : Boolean := True;
5818 All_Overloadable : Boolean := Is_Overloadable (E);
5822 while Present (E2) loop
5823 if Is_Immediately_Visible (E2) then
5825 -- If the use-visible entity comes from the actual for a
5826 -- formal package, it hides a directly visible entity from
5827 -- outside the instance.
5829 if From_Actual_Package (E)
5830 and then Scope_Depth (Scope (E2)) < Scope_Depth (Inst)
5835 goto Immediately_Visible_Entity;
5838 elsif Is_Potentially_Use_Visible (E2) then
5839 Only_One_Visible := False;
5840 All_Overloadable := All_Overloadable and Is_Overloadable (E2);
5842 -- Ada 2005 (AI-262): Protect against a form of Beaujolais effect
5843 -- that can occur in private_with clauses. Example:
5846 -- private with B; package A is
5847 -- package C is function B return Integer;
5849 -- V1 : Integer := B;
5850 -- private function B return Integer;
5851 -- V2 : Integer := B;
5854 -- V1 resolves to A.B, but V2 resolves to library unit B
5856 elsif Ekind (E2) = E_Function
5857 and then Scope (E2) = Standard_Standard
5858 and then Has_Private_With (E2)
5860 Only_One_Visible := False;
5861 All_Overloadable := False;
5862 Nvis_Is_Private_Subprg := True;
5869 -- On falling through this loop, we have checked that there are no
5870 -- immediately visible entities. Only_One_Visible is set if exactly
5871 -- one potentially use visible entity exists. All_Overloadable is
5872 -- set if all the potentially use visible entities are overloadable.
5873 -- The condition for legality is that either there is one potentially
5874 -- use visible entity, or if there is more than one, then all of them
5875 -- are overloadable.
5877 if Only_One_Visible or All_Overloadable then
5880 -- If there is more than one potentially use-visible entity and at
5881 -- least one of them non-overloadable, we have an error (RM 8.4(11)).
5882 -- Note that E points to the first such entity on the homonym list.
5885 -- If one of the entities is declared in an actual package, it
5886 -- was visible in the generic, and takes precedence over other
5887 -- entities that are potentially use-visible. The same applies
5888 -- if the entity is declared in a local instantiation of the
5889 -- current instance.
5893 -- Find the current instance
5895 Inst := Current_Scope;
5896 while Present (Inst) and then Inst /= Standard_Standard loop
5897 if Is_Generic_Instance (Inst) then
5901 Inst := Scope (Inst);
5904 -- Reexamine the candidate entities, giving priority to those
5905 -- that were visible within the generic.
5908 while Present (E2) loop
5909 Nested_Inst := Nearest_Enclosing_Instance (E2);
5911 -- The entity is declared within an actual package, or in a
5912 -- nested instance. The ">=" accounts for the case where the
5913 -- current instance and the nested instance are the same.
5915 if From_Actual_Package (E2)
5916 or else (Present (Nested_Inst)
5917 and then Scope_Depth (Nested_Inst) >=
5930 elsif Is_Predefined_Unit (Current_Sem_Unit) then
5931 -- A use clause in the body of a system file creates conflict
5932 -- with some entity in a user scope, while rtsfind is active.
5933 -- Keep only the entity coming from another predefined unit.
5936 while Present (E2) loop
5937 if In_Predefined_Unit (E2) then
5945 -- Entity must exist because predefined unit is correct
5947 raise Program_Error;
5956 -- Come here with E set to the first immediately visible entity on
5957 -- the homonym chain. This is the one we want unless there is another
5958 -- immediately visible entity further on in the chain for an inner
5959 -- scope (RM 8.3(8)).
5961 <<Immediately_Visible_Entity>> declare
5966 -- Find scope level of initial entity. When compiling through
5967 -- Rtsfind, the previous context is not completely invisible, and
5968 -- an outer entity may appear on the chain, whose scope is below
5969 -- the entry for Standard that delimits the current scope stack.
5970 -- Indicate that the level for this spurious entry is outside of
5971 -- the current scope stack.
5973 Level := Scope_Stack.Last;
5975 Scop := Scope_Stack.Table (Level).Entity;
5976 exit when Scop = Scope (E);
5978 exit when Scop = Standard_Standard;
5981 -- Now search remainder of homonym chain for more inner entry
5982 -- If the entity is Standard itself, it has no scope, and we
5983 -- compare it with the stack entry directly.
5986 while Present (E2) loop
5987 if Is_Immediately_Visible (E2) then
5989 -- If a generic package contains a local declaration that
5990 -- has the same name as the generic, there may be a visibility
5991 -- conflict in an instance, where the local declaration must
5992 -- also hide the name of the corresponding package renaming.
5993 -- We check explicitly for a package declared by a renaming,
5994 -- whose renamed entity is an instance that is on the scope
5995 -- stack, and that contains a homonym in the same scope. Once
5996 -- we have found it, we know that the package renaming is not
5997 -- immediately visible, and that the identifier denotes the
5998 -- other entity (and its homonyms if overloaded).
6000 if Scope (E) = Scope (E2)
6001 and then Ekind (E) = E_Package
6002 and then Present (Renamed_Object (E))
6003 and then Is_Generic_Instance (Renamed_Object (E))
6004 and then In_Open_Scopes (Renamed_Object (E))
6005 and then Comes_From_Source (N)
6007 Set_Is_Immediately_Visible (E, False);
6011 for J in Level + 1 .. Scope_Stack.Last loop
6012 if Scope_Stack.Table (J).Entity = Scope (E2)
6013 or else Scope_Stack.Table (J).Entity = E2
6026 -- At the end of that loop, E is the innermost immediately
6027 -- visible entity, so we are all set.
6030 -- Come here with entity found, and stored in E
6034 -- Check violation of No_Wide_Characters restriction
6036 Check_Wide_Character_Restriction (E, N);
6038 -- When distribution features are available (Get_PCS_Name /=
6039 -- Name_No_DSA), a remote access-to-subprogram type is converted
6040 -- into a record type holding whatever information is needed to
6041 -- perform a remote call on an RCI subprogram. In that case we
6042 -- rewrite any occurrence of the RAS type into the equivalent record
6043 -- type here. 'Access attribute references and RAS dereferences are
6044 -- then implemented using specific TSSs. However when distribution is
6045 -- not available (case of Get_PCS_Name = Name_No_DSA), we bypass the
6046 -- generation of these TSSs, and we must keep the RAS type in its
6047 -- original access-to-subprogram form (since all calls through a
6048 -- value of such type will be local anyway in the absence of a PCS).
6050 if Comes_From_Source (N)
6051 and then Is_Remote_Access_To_Subprogram_Type (E)
6052 and then Ekind (E) = E_Access_Subprogram_Type
6053 and then Expander_Active
6054 and then Get_PCS_Name /= Name_No_DSA
6056 Rewrite (N, New_Occurrence_Of (Equivalent_Type (E), Sloc (N)));
6060 -- Set the entity. Note that the reason we call Set_Entity for the
6061 -- overloadable case, as opposed to Set_Entity_With_Checks is
6062 -- that in the overloaded case, the initial call can set the wrong
6063 -- homonym. The call that sets the right homonym is in Sem_Res and
6064 -- that call does use Set_Entity_With_Checks, so we don't miss
6067 if Is_Overloadable (E) then
6070 Set_Entity_With_Checks (N, E);
6076 Set_Etype (N, Get_Full_View (Etype (E)));
6079 if Debug_Flag_E then
6080 Write_Str (" found ");
6081 Write_Entity_Info (E, " ");
6084 -- If the Ekind of the entity is Void, it means that all homonyms
6085 -- are hidden from all visibility (RM 8.3(5,14-20)). However, this
6086 -- test is skipped if the current scope is a record and the name is
6087 -- a pragma argument expression (case of Atomic and Volatile pragmas
6088 -- and possibly other similar pragmas added later, which are allowed
6089 -- to reference components in the current record).
6091 if Ekind (E) = E_Void
6093 (not Is_Record_Type (Current_Scope)
6094 or else Nkind (Parent (N)) /= N_Pragma_Argument_Association)
6096 Premature_Usage (N);
6098 -- If the entity is overloadable, collect all interpretations of the
6099 -- name for subsequent overload resolution. We optimize a bit here to
6100 -- do this only if we have an overloadable entity that is not on its
6101 -- own on the homonym chain.
6103 elsif Is_Overloadable (E)
6104 and then (Present (Homonym (E)) or else Current_Entity (N) /= E)
6106 Collect_Interps (N);
6108 -- If no homonyms were visible, the entity is unambiguous
6110 if not Is_Overloaded (N) then
6111 if not Is_Actual_Parameter then
6112 Generate_Reference (E, N);
6116 -- Case of non-overloadable entity, set the entity providing that
6117 -- we do not have the case of a discriminant reference within a
6118 -- default expression. Such references are replaced with the
6119 -- corresponding discriminal, which is the formal corresponding to
6120 -- to the discriminant in the initialization procedure.
6123 -- Entity is unambiguous, indicate that it is referenced here
6125 -- For a renaming of an object, always generate simple reference,
6126 -- we don't try to keep track of assignments in this case, except
6127 -- in SPARK mode where renamings are traversed for generating
6128 -- local effects of subprograms.
6131 and then Present (Renamed_Object (E))
6132 and then not GNATprove_Mode
6134 Generate_Reference (E, N);
6136 -- If the renamed entity is a private protected component,
6137 -- reference the original component as well. This needs to be
6138 -- done because the private renamings are installed before any
6139 -- analysis has occurred. Reference to a private component will
6140 -- resolve to the renaming and the original component will be
6141 -- left unreferenced, hence the following.
6143 if Is_Prival (E) then
6144 Generate_Reference (Prival_Link (E), N);
6147 -- One odd case is that we do not want to set the Referenced flag
6148 -- if the entity is a label, and the identifier is the label in
6149 -- the source, since this is not a reference from the point of
6150 -- view of the user.
6152 elsif Nkind (Parent (N)) = N_Label then
6154 R : constant Boolean := Referenced (E);
6157 -- Generate reference unless this is an actual parameter
6158 -- (see comment below).
6160 if not Is_Actual_Parameter then
6161 Generate_Reference (E, N);
6162 Set_Referenced (E, R);
6166 -- Normal case, not a label: generate reference
6169 if not Is_Actual_Parameter then
6171 -- Package or generic package is always a simple reference
6173 if Is_Package_Or_Generic_Package (E) then
6174 Generate_Reference (E, N, 'r');
6176 -- Else see if we have a left hand side
6181 Generate_Reference (E, N, 'm');
6184 Generate_Reference (E, N, 'r');
6186 -- If we don't know now, generate reference later
6189 Defer_Reference ((E, N));
6195 Set_Entity_Or_Discriminal (N, E);
6197 -- The name may designate a generalized reference, in which case
6198 -- the dereference interpretation will be included. Context is
6199 -- one in which a name is legal.
6201 if Ada_Version >= Ada_2012
6203 (Nkind (Parent (N)) in N_Subexpr
6204 or else Nkind (Parent (N)) in N_Assignment_Statement
6205 | N_Object_Declaration
6206 | N_Parameter_Association)
6208 Check_Implicit_Dereference (N, Etype (E));
6213 -- Mark relevant use-type and use-package clauses as effective if the
6214 -- node in question is not overloaded and therefore does not require
6217 -- Note: Generic actual subprograms do not follow the normal resolution
6218 -- path, so ignore the fact that they are overloaded and mark them
6221 if Nkind (N) not in N_Subexpr or else not Is_Overloaded (N) then
6222 Mark_Use_Clauses (N);
6225 -- Come here with entity set
6228 Check_Restriction_No_Use_Of_Entity (N);
6230 -- Annotate the tree by creating a variable reference marker in case the
6231 -- original variable reference is folded or optimized away. The variable
6232 -- reference marker is automatically saved for later examination by the
6233 -- ABE Processing phase. Variable references which act as actuals in a
6234 -- call require special processing and are left to Resolve_Actuals. The
6235 -- reference is a write when it appears on the left hand side of an
6238 if Needs_Variable_Reference_Marker (N => N, Calls_OK => False) then
6240 Is_Assignment_LHS : constant Boolean := Is_LHS (N) = Yes;
6243 Build_Variable_Reference_Marker
6245 Read => not Is_Assignment_LHS,
6246 Write => Is_Assignment_LHS);
6249 end Find_Direct_Name;
6251 ------------------------
6252 -- Find_Expanded_Name --
6253 ------------------------
6255 -- This routine searches the homonym chain of the entity until it finds
6256 -- an entity declared in the scope denoted by the prefix. If the entity
6257 -- is private, it may nevertheless be immediately visible, if we are in
6258 -- the scope of its declaration.
6260 procedure Find_Expanded_Name (N : Node_Id) is
6261 function In_Abstract_View_Pragma (Nod : Node_Id) return Boolean;
6262 -- Determine whether expanded name Nod appears within a pragma which is
6263 -- a suitable context for an abstract view of a state or variable. The
6264 -- following pragmas fall in this category:
6271 -- In addition, pragma Abstract_State is also considered suitable even
6272 -- though it is an illegal context for an abstract view as this allows
6273 -- for proper resolution of abstract views of variables. This illegal
6274 -- context is later flagged in the analysis of indicator Part_Of.
6276 -----------------------------
6277 -- In_Abstract_View_Pragma --
6278 -----------------------------
6280 function In_Abstract_View_Pragma (Nod : Node_Id) return Boolean is
6284 -- Climb the parent chain looking for a pragma
6287 while Present (Par) loop
6288 if Nkind (Par) = N_Pragma then
6289 if Pragma_Name_Unmapped (Par)
6290 in Name_Abstract_State
6294 | Name_Refined_Depends
6295 | Name_Refined_Global
6299 -- Otherwise the pragma is not a legal context for an abstract
6306 -- Prevent the search from going too far
6308 elsif Is_Body_Or_Package_Declaration (Par) then
6312 Par := Parent (Par);
6316 end In_Abstract_View_Pragma;
6320 Selector : constant Node_Id := Selector_Name (N);
6322 Candidate : Entity_Id := Empty;
6326 -- Start of processing for Find_Expanded_Name
6329 P_Name := Entity (Prefix (N));
6331 -- If the prefix is a renamed package, look for the entity in the
6332 -- original package.
6334 if Ekind (P_Name) = E_Package
6335 and then Present (Renamed_Object (P_Name))
6337 P_Name := Renamed_Object (P_Name);
6339 if From_Limited_With (P_Name)
6340 and then not Unit_Is_Visible (Cunit (Get_Source_Unit (P_Name)))
6343 ("renaming of limited view of package & not usable in this"
6344 & " context (RM 8.5.3(3.1/2))", Prefix (N), P_Name);
6346 elsif Has_Limited_View (P_Name)
6347 and then not Unit_Is_Visible (Cunit (Get_Source_Unit (P_Name)))
6348 and then not Is_Visible_Through_Renamings (P_Name)
6351 ("renaming of limited view of package & not usable in this"
6352 & " context (RM 8.5.3(3.1/2))", Prefix (N), P_Name);
6355 -- Rewrite node with entity field pointing to renamed object
6357 Rewrite (Prefix (N), New_Copy (Prefix (N)));
6358 Set_Entity (Prefix (N), P_Name);
6360 -- If the prefix is an object of a concurrent type, look for
6361 -- the entity in the associated task or protected type.
6363 elsif Is_Concurrent_Type (Etype (P_Name)) then
6364 P_Name := Etype (P_Name);
6367 Id := Current_Entity (Selector);
6370 Is_New_Candidate : Boolean;
6373 while Present (Id) loop
6374 if Scope (Id) = P_Name then
6376 Is_New_Candidate := True;
6378 -- Handle abstract views of states and variables. These are
6379 -- acceptable candidates only when the reference to the view
6380 -- appears in certain pragmas.
6382 if Ekind (Id) = E_Abstract_State
6383 and then From_Limited_With (Id)
6384 and then Present (Non_Limited_View (Id))
6386 if In_Abstract_View_Pragma (N) then
6387 Candidate := Non_Limited_View (Id);
6388 Is_New_Candidate := True;
6390 -- Hide the candidate because it is not used in a proper
6395 Is_New_Candidate := False;
6399 -- Ada 2005 (AI-217): Handle shadow entities associated with
6400 -- types declared in limited-withed nested packages. We don't need
6401 -- to handle E_Incomplete_Subtype entities because the entities
6402 -- in the limited view are always E_Incomplete_Type and
6403 -- E_Class_Wide_Type entities (see Build_Limited_Views).
6405 -- Regarding the expression used to evaluate the scope, it
6406 -- is important to note that the limited view also has shadow
6407 -- entities associated nested packages. For this reason the
6408 -- correct scope of the entity is the scope of the real entity.
6409 -- The non-limited view may itself be incomplete, in which case
6410 -- get the full view if available.
6412 elsif Ekind (Id) in E_Incomplete_Type | E_Class_Wide_Type
6413 and then From_Limited_With (Id)
6414 and then Present (Non_Limited_View (Id))
6415 and then Scope (Non_Limited_View (Id)) = P_Name
6417 Candidate := Get_Full_View (Non_Limited_View (Id));
6418 Is_New_Candidate := True;
6420 -- Handle special case where the prefix is a renaming of a shadow
6421 -- package which is visible. Required to avoid reporting spurious
6424 elsif Ekind (P_Name) = E_Package
6425 and then From_Limited_With (P_Name)
6426 and then not From_Limited_With (Id)
6427 and then Sloc (Scope (Id)) = Sloc (P_Name)
6428 and then Unit_Is_Visible (Cunit (Get_Source_Unit (P_Name)))
6430 Candidate := Get_Full_View (Id);
6431 Is_New_Candidate := True;
6433 -- An unusual case arises with a fully qualified name for an
6434 -- entity local to a generic child unit package, within an
6435 -- instantiation of that package. The name of the unit now
6436 -- denotes the renaming created within the instance. This is
6437 -- only relevant in an instance body, see below.
6439 elsif Is_Generic_Instance (Scope (Id))
6440 and then In_Open_Scopes (Scope (Id))
6441 and then In_Instance_Body
6442 and then Ekind (Scope (Id)) = E_Package
6443 and then Ekind (Id) = E_Package
6444 and then Renamed_Entity (Id) = Scope (Id)
6445 and then Is_Immediately_Visible (P_Name)
6447 Is_New_Candidate := True;
6450 Is_New_Candidate := False;
6453 if Is_New_Candidate then
6455 -- If entity is a child unit, either it is a visible child of
6456 -- the prefix, or we are in the body of a generic prefix, as
6457 -- will happen when a child unit is instantiated in the body
6458 -- of a generic parent. This is because the instance body does
6459 -- not restore the full compilation context, given that all
6460 -- non-local references have been captured.
6462 if Is_Child_Unit (Id) or else P_Name = Standard_Standard then
6463 exit when Is_Visible_Lib_Unit (Id)
6464 or else (Is_Child_Unit (Id)
6465 and then In_Open_Scopes (Scope (Id))
6466 and then In_Instance_Body);
6468 exit when not Is_Hidden (Id);
6471 exit when Is_Immediately_Visible (Id);
6479 and then Ekind (P_Name) in E_Procedure | E_Function
6480 and then Is_Generic_Instance (P_Name)
6482 -- Expanded name denotes entity in (instance of) generic subprogram.
6483 -- The entity may be in the subprogram instance, or may denote one of
6484 -- the formals, which is declared in the enclosing wrapper package.
6486 P_Name := Scope (P_Name);
6488 Id := Current_Entity (Selector);
6489 while Present (Id) loop
6490 exit when Scope (Id) = P_Name;
6495 if No (Id) or else Chars (Id) /= Chars (Selector) then
6496 Set_Etype (N, Any_Type);
6498 -- If we are looking for an entity defined in System, try to find it
6499 -- in the child package that may have been provided as an extension
6500 -- to System. The Extend_System pragma will have supplied the name of
6501 -- the extension, which may have to be loaded.
6503 if Chars (P_Name) = Name_System
6504 and then Scope (P_Name) = Standard_Standard
6505 and then Present (System_Extend_Unit)
6506 and then Present_System_Aux (N)
6508 Set_Entity (Prefix (N), System_Aux_Id);
6509 Find_Expanded_Name (N);
6512 -- There is an implicit instance of the predefined operator in
6513 -- the given scope. The operator entity is defined in Standard.
6514 -- Has_Implicit_Operator makes the node into an Expanded_Name.
6516 elsif Nkind (Selector) = N_Operator_Symbol
6517 and then Has_Implicit_Operator (N)
6521 -- If there is no literal defined in the scope denoted by the
6522 -- prefix, the literal may belong to (a type derived from)
6523 -- Standard_Character, for which we have no explicit literals.
6525 elsif Nkind (Selector) = N_Character_Literal
6526 and then Has_Implicit_Character_Literal (N)
6531 -- If the prefix is a single concurrent object, use its name in
6532 -- the error message, rather than that of the anonymous type.
6534 if Is_Concurrent_Type (P_Name)
6535 and then Is_Internal_Name (Chars (P_Name))
6537 Error_Msg_Node_2 := Entity (Prefix (N));
6539 Error_Msg_Node_2 := P_Name;
6542 if P_Name = System_Aux_Id then
6543 P_Name := Scope (P_Name);
6544 Set_Entity (Prefix (N), P_Name);
6547 if Present (Candidate) then
6549 -- If we know that the unit is a child unit we can give a more
6550 -- accurate error message.
6552 if Is_Child_Unit (Candidate) then
6554 -- If the candidate is a private child unit and we are in
6555 -- the visible part of a public unit, specialize the error
6556 -- message. There might be a private with_clause for it,
6557 -- but it is not currently active.
6559 if Is_Private_Descendant (Candidate)
6560 and then Ekind (Current_Scope) = E_Package
6561 and then not In_Private_Part (Current_Scope)
6562 and then not Is_Private_Descendant (Current_Scope)
6565 ("private child unit& is not visible here", Selector);
6567 -- Normal case where we have a missing with for a child unit
6570 Error_Msg_Qual_Level := 99;
6571 Error_Msg_NE -- CODEFIX
6572 ("missing `WITH &;`", Selector, Candidate);
6573 Error_Msg_Qual_Level := 0;
6576 -- Here we don't know that this is a child unit
6579 Error_Msg_NE ("& is not a visible entity of&", N, Selector);
6583 -- Within the instantiation of a child unit, the prefix may
6584 -- denote the parent instance, but the selector has the name
6585 -- of the original child. That is to say, when A.B appears
6586 -- within an instantiation of generic child unit B, the scope
6587 -- stack includes an instance of A (P_Name) and an instance
6588 -- of B under some other name. We scan the scope to find this
6589 -- child instance, which is the desired entity.
6590 -- Note that the parent may itself be a child instance, if
6591 -- the reference is of the form A.B.C, in which case A.B has
6592 -- already been rewritten with the proper entity.
6594 if In_Open_Scopes (P_Name)
6595 and then Is_Generic_Instance (P_Name)
6598 Gen_Par : constant Entity_Id :=
6599 Generic_Parent (Specification
6600 (Unit_Declaration_Node (P_Name)));
6601 S : Entity_Id := Current_Scope;
6605 for J in reverse 0 .. Scope_Stack.Last loop
6606 S := Scope_Stack.Table (J).Entity;
6608 exit when S = Standard_Standard;
6610 if Ekind (S) in E_Function | E_Package | E_Procedure
6613 Generic_Parent (Specification
6614 (Unit_Declaration_Node (S)));
6616 -- Check that P is a generic child of the generic
6617 -- parent of the prefix.
6620 and then Chars (P) = Chars (Selector)
6621 and then Scope (P) = Gen_Par
6632 -- If this is a selection from Ada, System or Interfaces, then
6633 -- we assume a missing with for the corresponding package.
6635 if Is_Known_Unit (N)
6636 and then not (Present (Entity (Prefix (N)))
6637 and then Scope (Entity (Prefix (N))) /=
6640 if not Error_Posted (N) then
6641 Error_Msg_Node_2 := Selector;
6642 Error_Msg_N -- CODEFIX
6643 ("missing `WITH &.&;`", Prefix (N));
6646 -- If this is a selection from a dummy package, then suppress
6647 -- the error message, of course the entity is missing if the
6648 -- package is missing.
6650 elsif Sloc (Error_Msg_Node_2) = No_Location then
6653 -- Here we have the case of an undefined component
6656 -- The prefix may hide a homonym in the context that
6657 -- declares the desired entity. This error can use a
6658 -- specialized message.
6660 if In_Open_Scopes (P_Name) then
6662 H : constant Entity_Id := Homonym (P_Name);
6666 and then Is_Compilation_Unit (H)
6668 (Is_Immediately_Visible (H)
6669 or else Is_Visible_Lib_Unit (H))
6671 Id := First_Entity (H);
6672 while Present (Id) loop
6673 if Chars (Id) = Chars (Selector) then
6674 Error_Msg_Qual_Level := 99;
6675 Error_Msg_Name_1 := Chars (Selector);
6677 ("% not declared in&", N, P_Name);
6679 ("\use fully qualified name starting with "
6680 & "Standard to make& visible", N, H);
6681 Error_Msg_Qual_Level := 0;
6689 -- If not found, standard error message
6691 Error_Msg_NE ("& not declared in&", N, Selector);
6697 -- Might be worth specializing the case when the prefix
6698 -- is a limited view.
6699 -- ... not declared in limited view of...
6701 Error_Msg_NE ("& not declared in&", N, Selector);
6704 -- Check for misspelling of some entity in prefix
6706 Id := First_Entity (P_Name);
6707 while Present (Id) loop
6708 if Is_Bad_Spelling_Of (Chars (Id), Chars (Selector))
6709 and then not Is_Internal_Name (Chars (Id))
6711 Error_Msg_NE -- CODEFIX
6712 ("possible misspelling of&", Selector, Id);
6719 -- Specialize the message if this may be an instantiation
6720 -- of a child unit that was not mentioned in the context.
6722 if Nkind (Parent (N)) = N_Package_Instantiation
6723 and then Is_Generic_Instance (Entity (Prefix (N)))
6724 and then Is_Compilation_Unit
6725 (Generic_Parent (Parent (Entity (Prefix (N)))))
6727 Error_Msg_Node_2 := Selector;
6728 Error_Msg_N -- CODEFIX
6729 ("\missing `WITH &.&;`", Prefix (N));
6739 if Comes_From_Source (N)
6740 and then Is_Remote_Access_To_Subprogram_Type (Id)
6741 and then Ekind (Id) = E_Access_Subprogram_Type
6742 and then Present (Equivalent_Type (Id))
6744 -- If we are not actually generating distribution code (i.e. the
6745 -- current PCS is the dummy non-distributed version), then the
6746 -- Equivalent_Type will be missing, and Id should be treated as
6747 -- a regular access-to-subprogram type.
6749 Id := Equivalent_Type (Id);
6750 Set_Chars (Selector, Chars (Id));
6753 -- Ada 2005 (AI-50217): Check usage of entities in limited withed units
6755 if Ekind (P_Name) = E_Package and then From_Limited_With (P_Name) then
6756 if From_Limited_With (Id)
6757 or else Is_Type (Id)
6758 or else Ekind (Id) = E_Package
6763 ("limited withed package can only be used to access incomplete "
6768 if Is_Task_Type (P_Name)
6769 and then ((Ekind (Id) = E_Entry
6770 and then Nkind (Parent (N)) /= N_Attribute_Reference)
6772 (Ekind (Id) = E_Entry_Family
6774 Nkind (Parent (Parent (N))) /= N_Attribute_Reference))
6776 -- If both the task type and the entry are in scope, this may still
6777 -- be the expanded name of an entry formal.
6779 if In_Open_Scopes (Id)
6780 and then Nkind (Parent (N)) = N_Selected_Component
6785 -- It is an entry call after all, either to the current task
6786 -- (which will deadlock) or to an enclosing task.
6788 Analyze_Selected_Component (N);
6793 Change_Selected_Component_To_Expanded_Name (N);
6795 -- Preserve relevant elaboration-related attributes of the context which
6796 -- are no longer available or very expensive to recompute once analysis,
6797 -- resolution, and expansion are over.
6799 Mark_Elaboration_Attributes
6805 -- Set appropriate type
6807 if Is_Type (Id) then
6810 Set_Etype (N, Get_Full_View (Etype (Id)));
6813 -- Do style check and generate reference, but skip both steps if this
6814 -- entity has homonyms, since we may not have the right homonym set yet.
6815 -- The proper homonym will be set during the resolve phase.
6817 if Has_Homonym (Id) then
6821 Set_Entity_Or_Discriminal (N, Id);
6825 Generate_Reference (Id, N, 'm');
6828 Generate_Reference (Id, N, 'r');
6831 Defer_Reference ((Id, N));
6835 -- Check for violation of No_Wide_Characters
6837 Check_Wide_Character_Restriction (Id, N);
6839 -- If the Ekind of the entity is Void, it means that all homonyms are
6840 -- hidden from all visibility (RM 8.3(5,14-20)).
6842 if Ekind (Id) = E_Void then
6843 Premature_Usage (N);
6845 elsif Is_Overloadable (Id) and then Present (Homonym (Id)) then
6847 H : Entity_Id := Homonym (Id);
6850 while Present (H) loop
6851 if Scope (H) = Scope (Id)
6852 and then (not Is_Hidden (H)
6853 or else Is_Immediately_Visible (H))
6855 Collect_Interps (N);
6862 -- If an extension of System is present, collect possible explicit
6863 -- overloadings declared in the extension.
6865 if Chars (P_Name) = Name_System
6866 and then Scope (P_Name) = Standard_Standard
6867 and then Present (System_Extend_Unit)
6868 and then Present_System_Aux (N)
6870 H := Current_Entity (Id);
6872 while Present (H) loop
6873 if Scope (H) = System_Aux_Id then
6874 Add_One_Interp (N, H, Etype (H));
6883 if Nkind (Selector_Name (N)) = N_Operator_Symbol
6884 and then Scope (Id) /= Standard_Standard
6886 -- In addition to user-defined operators in the given scope, there
6887 -- may be an implicit instance of the predefined operator. The
6888 -- operator (defined in Standard) is found in Has_Implicit_Operator,
6889 -- and added to the interpretations. Procedure Add_One_Interp will
6890 -- determine which hides which.
6892 if Has_Implicit_Operator (N) then
6897 -- If there is a single interpretation for N we can generate a
6898 -- reference to the unique entity found.
6900 if Is_Overloadable (Id) and then not Is_Overloaded (N) then
6901 Generate_Reference (Id, N);
6904 -- Mark relevant use-type and use-package clauses as effective if the
6905 -- node in question is not overloaded and therefore does not require
6908 if Nkind (N) not in N_Subexpr or else not Is_Overloaded (N) then
6909 Mark_Use_Clauses (N);
6912 Check_Restriction_No_Use_Of_Entity (N);
6914 -- Annotate the tree by creating a variable reference marker in case the
6915 -- original variable reference is folded or optimized away. The variable
6916 -- reference marker is automatically saved for later examination by the
6917 -- ABE Processing phase. Variable references which act as actuals in a
6918 -- call require special processing and are left to Resolve_Actuals. The
6919 -- reference is a write when it appears on the left hand side of an
6922 if Needs_Variable_Reference_Marker
6927 Is_Assignment_LHS : constant Boolean := Is_LHS (N) = Yes;
6930 Build_Variable_Reference_Marker
6932 Read => not Is_Assignment_LHS,
6933 Write => Is_Assignment_LHS);
6936 end Find_Expanded_Name;
6938 --------------------
6939 -- Find_Most_Prev --
6940 --------------------
6942 function Find_Most_Prev (Use_Clause : Node_Id) return Node_Id is
6946 -- Loop through the Prev_Use_Clause chain
6949 while Present (Prev_Use_Clause (Curr)) loop
6950 Curr := Prev_Use_Clause (Curr);
6956 -------------------------
6957 -- Find_Renamed_Entity --
6958 -------------------------
6960 function Find_Renamed_Entity
6964 Is_Actual : Boolean := False) return Entity_Id
6967 I1 : Interp_Index := 0; -- Suppress junk warnings
6973 function Find_Nearer_Entity
6976 Old2_S : Entity_Id) return Entity_Id;
6977 -- Determine whether one of Old_S1 and Old_S2 is nearer to New_S than
6978 -- the other, and return it if so. Return Empty otherwise. We use this
6979 -- in conjunction with Inherit_Renamed_Profile to simplify later type
6980 -- disambiguation for actual subprograms in instances.
6982 function Is_Visible_Operation (Op : Entity_Id) return Boolean;
6983 -- If the renamed entity is an implicit operator, check whether it is
6984 -- visible because its operand type is properly visible. This check
6985 -- applies to explicit renamed entities that appear in the source in a
6986 -- renaming declaration or a formal subprogram instance, but not to
6987 -- default generic actuals with a name.
6989 function Report_Overload return Entity_Id;
6990 -- List possible interpretations, and specialize message in the
6991 -- case of a generic actual.
6993 function Within (Inner, Outer : Entity_Id) return Boolean;
6994 -- Determine whether a candidate subprogram is defined within the
6995 -- enclosing instance. If yes, it has precedence over outer candidates.
6997 --------------------------
6998 -- Find_Nearer_Entity --
6999 --------------------------
7001 function Find_Nearer_Entity
7004 Old2_S : Entity_Id) return Entity_Id
7012 New_F := First_Formal (New_S);
7013 Old1_F := First_Formal (Old1_S);
7014 Old2_F := First_Formal (Old2_S);
7016 -- The criterion is whether the type of the formals of one of Old1_S
7017 -- and Old2_S is an ancestor subtype of the type of the corresponding
7018 -- formals of New_S while the other is not (we already know that they
7019 -- are all subtypes of the same base type).
7021 -- This makes it possible to find the more correct renamed entity in
7022 -- the case of a generic instantiation nested in an enclosing one for
7023 -- which different formal types get the same actual type, which will
7024 -- in turn make it possible for Inherit_Renamed_Profile to preserve
7025 -- types on formal parameters and ultimately simplify disambiguation.
7027 -- Consider the follow package G:
7030 -- type Item_T is private;
7031 -- with function Compare (L, R: Item_T) return Boolean is <>;
7033 -- type Bound_T is private;
7034 -- with function Compare (L, R : Bound_T) return Boolean is <>;
7039 -- package body G is
7040 -- package My_Inner is Inner_G (Bound_T);
7044 -- with the following package Inner_G:
7047 -- type T is private;
7048 -- with function Compare (L, R: T) return Boolean is <>;
7049 -- package Inner_G is
7050 -- function "<" (L, R: T) return Boolean is (Compare (L, R));
7053 -- If G is instantiated on the same actual type with a single Compare
7057 -- function Compare (L, R : T) return Boolean;
7058 -- package My_G is new (T, T);
7060 -- then the renaming generated for Compare in the inner instantiation
7061 -- is ambiguous: it can rename either of the renamings generated for
7062 -- the outer instantiation. Now if the first one is picked up, then
7063 -- the subtypes of the formal parameters of the renaming will not be
7064 -- preserved in Inherit_Renamed_Profile because they are subtypes of
7065 -- the Bound_T formal type and not of the Item_T formal type, so we
7066 -- need to arrange for the second one to be picked up instead.
7068 while Present (New_F) loop
7069 if Etype (Old1_F) /= Etype (Old2_F) then
7070 Anc_T := Ancestor_Subtype (Etype (New_F));
7072 if Etype (Old1_F) = Anc_T then
7074 elsif Etype (Old2_F) = Anc_T then
7079 Next_Formal (New_F);
7080 Next_Formal (Old1_F);
7081 Next_Formal (Old2_F);
7084 pragma Assert (No (Old1_F));
7085 pragma Assert (No (Old2_F));
7088 end Find_Nearer_Entity;
7090 --------------------------
7091 -- Is_Visible_Operation --
7092 --------------------------
7094 function Is_Visible_Operation (Op : Entity_Id) return Boolean is
7100 if Ekind (Op) /= E_Operator
7101 or else Scope (Op) /= Standard_Standard
7102 or else (In_Instance
7103 and then (not Is_Actual
7104 or else Present (Enclosing_Instance)))
7109 -- For a fixed point type operator, check the resulting type,
7110 -- because it may be a mixed mode integer * fixed operation.
7112 if Present (Next_Formal (First_Formal (New_S)))
7113 and then Is_Fixed_Point_Type (Etype (New_S))
7115 Typ := Etype (New_S);
7117 Typ := Etype (First_Formal (New_S));
7120 Btyp := Base_Type (Typ);
7122 if Nkind (Nam) /= N_Expanded_Name then
7123 return (In_Open_Scopes (Scope (Btyp))
7124 or else Is_Potentially_Use_Visible (Btyp)
7125 or else In_Use (Btyp)
7126 or else In_Use (Scope (Btyp)));
7129 Scop := Entity (Prefix (Nam));
7131 if Ekind (Scop) = E_Package
7132 and then Present (Renamed_Object (Scop))
7134 Scop := Renamed_Object (Scop);
7137 -- Operator is visible if prefix of expanded name denotes
7138 -- scope of type, or else type is defined in System_Aux
7139 -- and the prefix denotes System.
7141 return Scope (Btyp) = Scop
7142 or else (Scope (Btyp) = System_Aux_Id
7143 and then Scope (Scope (Btyp)) = Scop);
7146 end Is_Visible_Operation;
7152 function Within (Inner, Outer : Entity_Id) return Boolean is
7156 Sc := Scope (Inner);
7157 while Sc /= Standard_Standard loop
7168 ---------------------
7169 -- Report_Overload --
7170 ---------------------
7172 function Report_Overload return Entity_Id is
7175 Error_Msg_NE -- CODEFIX
7176 ("ambiguous actual subprogram&, " &
7177 "possible interpretations:", N, Nam);
7179 Error_Msg_N -- CODEFIX
7180 ("ambiguous subprogram, " &
7181 "possible interpretations:", N);
7184 List_Interps (Nam, N);
7186 end Report_Overload;
7188 -- Start of processing for Find_Renamed_Entity
7192 Candidate_Renaming := Empty;
7194 if Is_Overloaded (Nam) then
7195 Get_First_Interp (Nam, Ind, It);
7196 while Present (It.Nam) loop
7197 if Entity_Matches_Spec (It.Nam, New_S)
7198 and then Is_Visible_Operation (It.Nam)
7200 if Old_S /= Any_Id then
7202 -- Note: The call to Disambiguate only happens if a
7203 -- previous interpretation was found, in which case I1
7204 -- has received a value.
7206 It1 := Disambiguate (Nam, I1, Ind, Etype (Old_S));
7208 if It1 = No_Interp then
7209 Inst := Enclosing_Instance;
7211 if Present (Inst) then
7212 if Within (It.Nam, Inst) then
7213 if Within (Old_S, Inst) then
7215 It_D : constant Uint := Scope_Depth (It.Nam);
7216 Old_D : constant Uint := Scope_Depth (Old_S);
7219 -- Choose the innermost subprogram, which
7220 -- would hide the outer one in the generic.
7222 if Old_D > It_D then
7224 elsif It_D > Old_D then
7228 -- Otherwise, if we can determine that one
7229 -- of the entities is nearer to the renaming
7230 -- than the other, choose it. If not, then
7231 -- return the newer one as done historically.
7234 Find_Nearer_Entity (New_S, Old_S, It.Nam);
7235 if Present (N_Ent) then
7243 elsif Within (Old_S, Inst) then
7247 return Report_Overload;
7250 -- If not within an instance, ambiguity is real
7253 return Report_Overload;
7267 Present (First_Formal (It.Nam))
7268 and then Present (First_Formal (New_S))
7269 and then (Base_Type (Etype (First_Formal (It.Nam))) =
7270 Base_Type (Etype (First_Formal (New_S))))
7272 Candidate_Renaming := It.Nam;
7275 Get_Next_Interp (Ind, It);
7278 Set_Entity (Nam, Old_S);
7280 if Old_S /= Any_Id then
7281 Set_Is_Overloaded (Nam, False);
7284 -- Non-overloaded case
7288 and then Present (Enclosing_Instance)
7289 and then Entity_Matches_Spec (Entity (Nam), New_S)
7291 Old_S := Entity (Nam);
7293 elsif Entity_Matches_Spec (Entity (Nam), New_S) then
7294 Candidate_Renaming := New_S;
7296 if Is_Visible_Operation (Entity (Nam)) then
7297 Old_S := Entity (Nam);
7300 elsif Present (First_Formal (Entity (Nam)))
7301 and then Present (First_Formal (New_S))
7302 and then (Base_Type (Etype (First_Formal (Entity (Nam)))) =
7303 Base_Type (Etype (First_Formal (New_S))))
7305 Candidate_Renaming := Entity (Nam);
7310 end Find_Renamed_Entity;
7312 -----------------------------
7313 -- Find_Selected_Component --
7314 -----------------------------
7316 procedure Find_Selected_Component (N : Node_Id) is
7317 P : constant Node_Id := Prefix (N);
7320 -- Entity denoted by prefix
7327 function Available_Subtype return Boolean;
7328 -- A small optimization: if the prefix is constrained and the component
7329 -- is an array type we may already have a usable subtype for it, so we
7330 -- can use it rather than generating a new one, because the bounds
7331 -- will be the values of the discriminants and not discriminant refs.
7332 -- This simplifies value tracing in GNATprove. For consistency, both
7333 -- the entity name and the subtype come from the constrained component.
7335 -- This is only used in GNATprove mode: when generating code it may be
7336 -- necessary to create an itype in the scope of use of the selected
7337 -- component, e.g. in the context of a expanded record equality.
7339 function Is_Reference_In_Subunit return Boolean;
7340 -- In a subunit, the scope depth is not a proper measure of hiding,
7341 -- because the context of the proper body may itself hide entities in
7342 -- parent units. This rare case requires inspecting the tree directly
7343 -- because the proper body is inserted in the main unit and its context
7344 -- is simply added to that of the parent.
7346 -----------------------
7347 -- Available_Subtype --
7348 -----------------------
7350 function Available_Subtype return Boolean is
7354 if GNATprove_Mode then
7355 Comp := First_Entity (Etype (P));
7356 while Present (Comp) loop
7357 if Chars (Comp) = Chars (Selector_Name (N)) then
7358 Set_Etype (N, Etype (Comp));
7359 Set_Entity (Selector_Name (N), Comp);
7360 Set_Etype (Selector_Name (N), Etype (Comp));
7364 Next_Component (Comp);
7369 end Available_Subtype;
7371 -----------------------------
7372 -- Is_Reference_In_Subunit --
7373 -----------------------------
7375 function Is_Reference_In_Subunit return Boolean is
7377 Comp_Unit : Node_Id;
7381 while Present (Comp_Unit)
7382 and then Nkind (Comp_Unit) /= N_Compilation_Unit
7384 Comp_Unit := Parent (Comp_Unit);
7387 if No (Comp_Unit) or else Nkind (Unit (Comp_Unit)) /= N_Subunit then
7391 -- Now check whether the package is in the context of the subunit
7393 Clause := First (Context_Items (Comp_Unit));
7394 while Present (Clause) loop
7395 if Nkind (Clause) = N_With_Clause
7396 and then Entity (Name (Clause)) = P_Name
7405 end Is_Reference_In_Subunit;
7407 -- Start of processing for Find_Selected_Component
7412 if Nkind (P) = N_Error then
7416 -- If the selector already has an entity, the node has been constructed
7417 -- in the course of expansion, and is known to be valid. Do not verify
7418 -- that it is defined for the type (it may be a private component used
7419 -- in the expansion of record equality).
7421 if Present (Entity (Selector_Name (N))) then
7422 if No (Etype (N)) or else Etype (N) = Any_Type then
7424 Sel_Name : constant Node_Id := Selector_Name (N);
7425 Selector : constant Entity_Id := Entity (Sel_Name);
7429 Set_Etype (Sel_Name, Etype (Selector));
7431 if not Is_Entity_Name (P) then
7435 -- Build an actual subtype except for the first parameter
7436 -- of an init proc, where this actual subtype is by
7437 -- definition incorrect, since the object is uninitialized
7438 -- (and does not even have defined discriminants etc.)
7440 if Is_Entity_Name (P)
7441 and then Ekind (Entity (P)) = E_Function
7443 Nam := New_Copy (P);
7445 if Is_Overloaded (P) then
7446 Save_Interps (P, Nam);
7449 Rewrite (P, Make_Function_Call (Sloc (P), Name => Nam));
7451 Analyze_Selected_Component (N);
7454 elsif Ekind (Selector) = E_Component
7455 and then (not Is_Entity_Name (P)
7456 or else Chars (Entity (P)) /= Name_uInit)
7458 -- Check if we already have an available subtype we can use
7460 if Ekind (Etype (P)) = E_Record_Subtype
7461 and then Nkind (Parent (Etype (P))) = N_Subtype_Declaration
7462 and then Is_Array_Type (Etype (Selector))
7463 and then not Is_Packed (Etype (Selector))
7464 and then Available_Subtype
7468 -- Do not build the subtype when referencing components of
7469 -- dispatch table wrappers. Required to avoid generating
7470 -- elaboration code with HI runtimes.
7472 elsif RTU_Loaded (Ada_Tags)
7474 ((RTE_Available (RE_Dispatch_Table_Wrapper)
7475 and then Scope (Selector) =
7476 RTE (RE_Dispatch_Table_Wrapper))
7478 (RTE_Available (RE_No_Dispatch_Table_Wrapper)
7479 and then Scope (Selector) =
7480 RTE (RE_No_Dispatch_Table_Wrapper)))
7485 Build_Actual_Subtype_Of_Component
7486 (Etype (Selector), N);
7493 if No (C_Etype) then
7494 C_Etype := Etype (Selector);
7496 Insert_Action (N, C_Etype);
7497 C_Etype := Defining_Identifier (C_Etype);
7500 Set_Etype (N, C_Etype);
7503 -- If the selected component appears within a default expression
7504 -- and it has an actual subtype, the preanalysis has not yet
7505 -- completed its analysis, because Insert_Actions is disabled in
7506 -- that context. Within the init proc of the enclosing type we
7507 -- must complete this analysis, if an actual subtype was created.
7509 elsif Inside_Init_Proc then
7511 Typ : constant Entity_Id := Etype (N);
7512 Decl : constant Node_Id := Declaration_Node (Typ);
7514 if Nkind (Decl) = N_Subtype_Declaration
7515 and then not Analyzed (Decl)
7516 and then Is_List_Member (Decl)
7517 and then No (Parent (Decl))
7520 Insert_Action (N, Decl);
7527 elsif Is_Entity_Name (P) then
7528 P_Name := Entity (P);
7530 -- The prefix may denote an enclosing type which is the completion
7531 -- of an incomplete type declaration.
7533 if Is_Type (P_Name) then
7534 Set_Entity (P, Get_Full_View (P_Name));
7535 Set_Etype (P, Entity (P));
7536 P_Name := Entity (P);
7539 P_Type := Base_Type (Etype (P));
7541 if Debug_Flag_E then
7542 Write_Str ("Found prefix type to be ");
7543 Write_Entity_Info (P_Type, " "); Write_Eol;
7546 -- If the prefix's type is an access type, get to the record type
7548 if Is_Access_Type (P_Type) then
7549 P_Type := Implicitly_Designated_Type (P_Type);
7552 -- First check for components of a record object (not the
7553 -- result of a call, which is handled below).
7555 if Has_Components (P_Type)
7556 and then not Is_Overloadable (P_Name)
7557 and then not Is_Type (P_Name)
7559 -- Selected component of record. Type checking will validate
7560 -- name of selector.
7562 -- ??? Could we rewrite an implicit dereference into an explicit
7565 Analyze_Selected_Component (N);
7567 -- Reference to type name in predicate/invariant expression
7569 elsif Is_Concurrent_Type (P_Type)
7570 and then not In_Open_Scopes (P_Name)
7571 and then (not Is_Concurrent_Type (Etype (P_Name))
7572 or else not In_Open_Scopes (Etype (P_Name)))
7574 -- Call to protected operation or entry. Type checking is
7575 -- needed on the prefix.
7577 Analyze_Selected_Component (N);
7579 elsif (In_Open_Scopes (P_Name)
7580 and then Ekind (P_Name) /= E_Void
7581 and then not Is_Overloadable (P_Name))
7582 or else (Is_Concurrent_Type (Etype (P_Name))
7583 and then In_Open_Scopes (Etype (P_Name)))
7585 -- Prefix denotes an enclosing loop, block, or task, i.e. an
7586 -- enclosing construct that is not a subprogram or accept.
7588 -- A special case: a protected body may call an operation
7589 -- on an external object of the same type, in which case it
7590 -- is not an expanded name. If the prefix is the type itself,
7591 -- or the context is a single synchronized object it can only
7592 -- be interpreted as an expanded name.
7594 if Is_Concurrent_Type (Etype (P_Name)) then
7596 or else Present (Anonymous_Object (Etype (P_Name)))
7598 Find_Expanded_Name (N);
7601 Analyze_Selected_Component (N);
7606 Find_Expanded_Name (N);
7609 elsif Ekind (P_Name) = E_Package then
7610 Find_Expanded_Name (N);
7612 elsif Is_Overloadable (P_Name) then
7614 -- The subprogram may be a renaming (of an enclosing scope) as
7615 -- in the case of the name of the generic within an instantiation.
7617 if Ekind (P_Name) in E_Procedure | E_Function
7618 and then Present (Alias (P_Name))
7619 and then Is_Generic_Instance (Alias (P_Name))
7621 P_Name := Alias (P_Name);
7624 if Is_Overloaded (P) then
7626 -- The prefix must resolve to a unique enclosing construct
7629 Found : Boolean := False;
7634 Get_First_Interp (P, Ind, It);
7635 while Present (It.Nam) loop
7636 if In_Open_Scopes (It.Nam) then
7639 "prefix must be unique enclosing scope", N);
7640 Set_Entity (N, Any_Id);
7641 Set_Etype (N, Any_Type);
7650 Get_Next_Interp (Ind, It);
7655 if In_Open_Scopes (P_Name) then
7656 Set_Entity (P, P_Name);
7657 Set_Is_Overloaded (P, False);
7658 Find_Expanded_Name (N);
7661 -- If no interpretation as an expanded name is possible, it
7662 -- must be a selected component of a record returned by a
7663 -- function call. Reformat prefix as a function call, the rest
7664 -- is done by type resolution.
7666 -- Error if the prefix is procedure or entry, as is P.X
7668 if Ekind (P_Name) /= E_Function
7670 (not Is_Overloaded (P)
7671 or else Nkind (Parent (N)) = N_Procedure_Call_Statement)
7673 -- Prefix may mention a package that is hidden by a local
7674 -- declaration: let the user know. Scan the full homonym
7675 -- chain, the candidate package may be anywhere on it.
7677 if Present (Homonym (Current_Entity (P_Name))) then
7678 P_Name := Current_Entity (P_Name);
7680 while Present (P_Name) loop
7681 exit when Ekind (P_Name) = E_Package;
7682 P_Name := Homonym (P_Name);
7685 if Present (P_Name) then
7686 if not Is_Reference_In_Subunit then
7687 Error_Msg_Sloc := Sloc (Entity (Prefix (N)));
7689 ("package& is hidden by declaration#", N, P_Name);
7692 Set_Entity (Prefix (N), P_Name);
7693 Find_Expanded_Name (N);
7697 P_Name := Entity (Prefix (N));
7702 ("invalid prefix in selected component&", N, P_Name);
7703 Change_Selected_Component_To_Expanded_Name (N);
7704 Set_Entity (N, Any_Id);
7705 Set_Etype (N, Any_Type);
7707 -- Here we have a function call, so do the reformatting
7710 Nam := New_Copy (P);
7711 Save_Interps (P, Nam);
7713 -- We use Replace here because this is one of those cases
7714 -- where the parser has missclassified the node, and we fix
7715 -- things up and then do the semantic analysis on the fixed
7716 -- up node. Normally we do this using one of the Sinfo.CN
7717 -- routines, but this is too tricky for that.
7719 -- Note that using Rewrite would be wrong, because we would
7720 -- have a tree where the original node is unanalyzed.
7723 Make_Function_Call (Sloc (P), Name => Nam));
7725 -- Now analyze the reformatted node
7729 -- If the prefix is illegal after this transformation, there
7730 -- may be visibility errors on the prefix. The safest is to
7731 -- treat the selected component as an error.
7733 if Error_Posted (P) then
7734 Set_Etype (N, Any_Type);
7738 Analyze_Selected_Component (N);
7743 -- Remaining cases generate various error messages
7746 -- Format node as expanded name, to avoid cascaded errors
7748 Change_Selected_Component_To_Expanded_Name (N);
7749 Set_Entity (N, Any_Id);
7750 Set_Etype (N, Any_Type);
7752 -- Issue error message, but avoid this if error issued already.
7753 -- Use identifier of prefix if one is available.
7755 if P_Name = Any_Id then
7758 -- It is not an error if the prefix is the current instance of
7759 -- type name, e.g. the expression of a type aspect, when it is
7760 -- analyzed within a generic unit. We still have to verify that a
7761 -- component of that name exists, and decorate the node
7764 elsif Is_Entity_Name (P) and then Is_Current_Instance (P) then
7769 Comp := First_Entity (Entity (P));
7770 while Present (Comp) loop
7771 if Chars (Comp) = Chars (Selector_Name (N)) then
7772 Set_Entity (N, Comp);
7773 Set_Etype (N, Etype (Comp));
7774 Set_Entity (Selector_Name (N), Comp);
7775 Set_Etype (Selector_Name (N), Etype (Comp));
7783 elsif Ekind (P_Name) = E_Void then
7784 Premature_Usage (P);
7786 elsif Nkind (P) /= N_Attribute_Reference then
7788 -- This may have been meant as a prefixed call to a primitive
7789 -- of an untagged type. If it is a function call check type of
7790 -- its first formal and add explanation.
7793 F : constant Entity_Id :=
7794 Current_Entity (Selector_Name (N));
7797 and then Is_Overloadable (F)
7798 and then Present (First_Entity (F))
7799 and then not Is_Tagged_Type (Etype (First_Entity (F)))
7802 ("prefixed call is only allowed for objects of a "
7803 & "tagged type", N);
7807 Error_Msg_N ("invalid prefix in selected component&", P);
7809 if Is_Incomplete_Type (P_Type)
7810 and then Is_Access_Type (Etype (P))
7813 ("\dereference must not be of an incomplete type "
7814 & "(RM 3.10.1)", P);
7818 Error_Msg_N ("invalid prefix in selected component", P);
7822 -- If prefix is not the name of an entity, it must be an expression,
7823 -- whose type is appropriate for a record. This is determined by
7826 Analyze_Selected_Component (N);
7829 Analyze_Dimension (N);
7830 end Find_Selected_Component;
7836 procedure Find_Type (N : Node_Id) is
7846 elsif Nkind (N) = N_Attribute_Reference then
7848 -- Class attribute. This is not valid in Ada 83 mode, but we do not
7849 -- need to enforce that at this point, since the declaration of the
7850 -- tagged type in the prefix would have been flagged already.
7852 if Attribute_Name (N) = Name_Class then
7853 Check_Restriction (No_Dispatch, N);
7854 Find_Type (Prefix (N));
7856 -- Propagate error from bad prefix
7858 if Etype (Prefix (N)) = Any_Type then
7859 Set_Entity (N, Any_Type);
7860 Set_Etype (N, Any_Type);
7864 T := Base_Type (Entity (Prefix (N)));
7866 -- Case where type is not known to be tagged. Its appearance in
7867 -- the prefix of the 'Class attribute indicates that the full view
7870 if not Is_Tagged_Type (T) then
7871 if Ekind (T) = E_Incomplete_Type then
7873 -- It is legal to denote the class type of an incomplete
7874 -- type. The full type will have to be tagged, of course.
7875 -- In Ada 2005 this usage is declared obsolescent, so we
7876 -- warn accordingly. This usage is only legal if the type
7877 -- is completed in the current scope, and not for a limited
7880 if Ada_Version >= Ada_2005 then
7882 -- Test whether the Available_View of a limited type view
7883 -- is tagged, since the limited view may not be marked as
7884 -- tagged if the type itself has an untagged incomplete
7885 -- type view in its package.
7887 if From_Limited_With (T)
7888 and then not Is_Tagged_Type (Available_View (T))
7891 ("prefix of Class attribute must be tagged", N);
7892 Set_Etype (N, Any_Type);
7893 Set_Entity (N, Any_Type);
7896 -- ??? This test is temporarily disabled (always
7897 -- False) because it causes an unwanted warning on
7898 -- GNAT sources (built with -gnatg, which includes
7899 -- Warn_On_Obsolescent_ Feature). Once this issue
7900 -- is cleared in the sources, it can be enabled.
7902 elsif Warn_On_Obsolescent_Feature and then False then
7904 ("applying ''Class to an untagged incomplete type"
7905 & " is an obsolescent feature (RM J.11)?r?", N);
7909 Set_Is_Tagged_Type (T);
7910 Set_Direct_Primitive_Operations (T, New_Elmt_List);
7911 Make_Class_Wide_Type (T);
7912 Set_Entity (N, Class_Wide_Type (T));
7913 Set_Etype (N, Class_Wide_Type (T));
7915 elsif Ekind (T) = E_Private_Type
7916 and then not Is_Generic_Type (T)
7917 and then In_Private_Part (Scope (T))
7919 -- The Class attribute can be applied to an untagged private
7920 -- type fulfilled by a tagged type prior to the full type
7921 -- declaration (but only within the parent package's private
7922 -- part). Create the class-wide type now and check that the
7923 -- full type is tagged later during its analysis. Note that
7924 -- we do not mark the private type as tagged, unlike the
7925 -- case of incomplete types, because the type must still
7926 -- appear untagged to outside units.
7928 if No (Class_Wide_Type (T)) then
7929 Make_Class_Wide_Type (T);
7932 Set_Entity (N, Class_Wide_Type (T));
7933 Set_Etype (N, Class_Wide_Type (T));
7936 -- Should we introduce a type Any_Tagged and use Wrong_Type
7937 -- here, it would be a bit more consistent???
7940 ("tagged type required, found}",
7941 Prefix (N), First_Subtype (T));
7942 Set_Entity (N, Any_Type);
7946 -- Case of tagged type
7949 if Is_Concurrent_Type (T) then
7950 if No (Corresponding_Record_Type (Entity (Prefix (N)))) then
7952 -- Previous error. Create a class-wide type for the
7953 -- synchronized type itself, with minimal semantic
7954 -- attributes, to catch other errors in some ACATS tests.
7956 pragma Assert (Serious_Errors_Detected /= 0);
7957 Make_Class_Wide_Type (T);
7958 C := Class_Wide_Type (T);
7959 Set_First_Entity (C, First_Entity (T));
7962 C := Class_Wide_Type
7963 (Corresponding_Record_Type (Entity (Prefix (N))));
7967 C := Class_Wide_Type (Entity (Prefix (N)));
7970 Set_Entity_With_Checks (N, C);
7971 Generate_Reference (C, N);
7975 -- Base attribute, not allowed in Ada 83
7977 elsif Attribute_Name (N) = Name_Base then
7978 if Ada_Version = Ada_83 and then Comes_From_Source (N) then
7980 ("(Ada 83) Base attribute not allowed in subtype mark", N);
7983 Find_Type (Prefix (N));
7984 Typ := Entity (Prefix (N));
7986 if Ada_Version >= Ada_95
7987 and then not Is_Scalar_Type (Typ)
7988 and then not Is_Generic_Type (Typ)
7991 ("prefix of Base attribute must be scalar type",
7994 elsif Warn_On_Redundant_Constructs
7995 and then Base_Type (Typ) = Typ
7997 Error_Msg_NE -- CODEFIX
7998 ("redundant attribute, & is its own base type?r?", N, Typ);
8001 T := Base_Type (Typ);
8003 -- Rewrite attribute reference with type itself (see similar
8004 -- processing in Analyze_Attribute, case Base). Preserve prefix
8005 -- if present, for other legality checks.
8007 if Nkind (Prefix (N)) = N_Expanded_Name then
8009 Make_Expanded_Name (Sloc (N),
8011 Prefix => New_Copy (Prefix (Prefix (N))),
8012 Selector_Name => New_Occurrence_Of (T, Sloc (N))));
8015 Rewrite (N, New_Occurrence_Of (T, Sloc (N)));
8022 elsif Attribute_Name (N) = Name_Stub_Type then
8024 -- This is handled in Analyze_Attribute
8028 -- All other attributes are invalid in a subtype mark
8031 Error_Msg_N ("invalid attribute in subtype mark", N);
8037 if Is_Entity_Name (N) then
8038 T_Name := Entity (N);
8040 Error_Msg_N ("subtype mark required in this context", N);
8041 Set_Etype (N, Any_Type);
8045 if T_Name = Any_Id or else Etype (N) = Any_Type then
8047 -- Undefined id. Make it into a valid type
8049 Set_Entity (N, Any_Type);
8051 elsif not Is_Type (T_Name)
8052 and then T_Name /= Standard_Void_Type
8054 Error_Msg_Sloc := Sloc (T_Name);
8055 Error_Msg_N ("subtype mark required in this context", N);
8056 Error_Msg_NE ("\\found & declared#", N, T_Name);
8057 Set_Entity (N, Any_Type);
8060 -- If the type is an incomplete type created to handle
8061 -- anonymous access components of a record type, then the
8062 -- incomplete type is the visible entity and subsequent
8063 -- references will point to it. Mark the original full
8064 -- type as referenced, to prevent spurious warnings.
8066 if Is_Incomplete_Type (T_Name)
8067 and then Present (Full_View (T_Name))
8068 and then not Comes_From_Source (T_Name)
8070 Set_Referenced (Full_View (T_Name));
8073 T_Name := Get_Full_View (T_Name);
8075 -- Ada 2005 (AI-251, AI-50217): Handle interfaces visible through
8076 -- limited-with clauses
8078 if From_Limited_With (T_Name)
8079 and then Is_Incomplete_Type (T_Name)
8080 and then Present (Non_Limited_View (T_Name))
8081 and then Is_Interface (Non_Limited_View (T_Name))
8083 T_Name := Non_Limited_View (T_Name);
8086 if In_Open_Scopes (T_Name) then
8087 if Ekind (Base_Type (T_Name)) = E_Task_Type then
8089 -- In Ada 2005, a task name can be used in an access
8090 -- definition within its own body. It cannot be used
8091 -- in the discriminant part of the task declaration,
8092 -- nor anywhere else in the declaration because entries
8093 -- cannot have access parameters.
8095 if Ada_Version >= Ada_2005
8096 and then Nkind (Parent (N)) = N_Access_Definition
8098 Set_Entity (N, T_Name);
8099 Set_Etype (N, T_Name);
8101 if Has_Completion (T_Name) then
8106 ("task type cannot be used as type mark " &
8107 "within its own declaration", N);
8112 ("task type cannot be used as type mark " &
8113 "within its own spec or body", N);
8116 elsif Ekind (Base_Type (T_Name)) = E_Protected_Type then
8118 -- In Ada 2005, a protected name can be used in an access
8119 -- definition within its own body.
8121 if Ada_Version >= Ada_2005
8122 and then Nkind (Parent (N)) = N_Access_Definition
8124 Set_Entity (N, T_Name);
8125 Set_Etype (N, T_Name);
8130 ("protected type cannot be used as type mark " &
8131 "within its own spec or body", N);
8135 Error_Msg_N ("type declaration cannot refer to itself", N);
8138 Set_Etype (N, Any_Type);
8139 Set_Entity (N, Any_Type);
8140 Set_Error_Posted (T_Name);
8144 Set_Entity (N, T_Name);
8145 Set_Etype (N, T_Name);
8149 if Present (Etype (N)) and then Comes_From_Source (N) then
8150 if Is_Fixed_Point_Type (Etype (N)) then
8151 Check_Restriction (No_Fixed_Point, N);
8152 elsif Is_Floating_Point_Type (Etype (N)) then
8153 Check_Restriction (No_Floating_Point, N);
8156 -- A Ghost type must appear in a specific context
8158 if Is_Ghost_Entity (Etype (N)) then
8159 Check_Ghost_Context (Etype (N), N);
8164 --------------------
8165 -- Has_Components --
8166 --------------------
8168 function Has_Components (Typ : Entity_Id) return Boolean is
8170 return Is_Record_Type (Typ)
8171 or else (Is_Private_Type (Typ) and then Has_Discriminants (Typ))
8172 or else (Is_Task_Type (Typ) and then Has_Discriminants (Typ))
8173 or else (Is_Incomplete_Type (Typ)
8174 and then From_Limited_With (Typ)
8175 and then Is_Record_Type (Available_View (Typ)));
8178 ------------------------------------
8179 -- Has_Implicit_Character_Literal --
8180 ------------------------------------
8182 function Has_Implicit_Character_Literal (N : Node_Id) return Boolean is
8184 Found : Boolean := False;
8185 P : constant Entity_Id := Entity (Prefix (N));
8186 Priv_Id : Entity_Id := Empty;
8189 if Ekind (P) = E_Package and then not In_Open_Scopes (P) then
8190 Priv_Id := First_Private_Entity (P);
8193 if P = Standard_Standard then
8194 Change_Selected_Component_To_Expanded_Name (N);
8195 Rewrite (N, Selector_Name (N));
8197 Set_Etype (Original_Node (N), Standard_Character);
8201 Id := First_Entity (P);
8202 while Present (Id) and then Id /= Priv_Id loop
8203 if Is_Standard_Character_Type (Id) and then Is_Base_Type (Id) then
8205 -- We replace the node with the literal itself, resolve as a
8206 -- character, and set the type correctly.
8209 Change_Selected_Component_To_Expanded_Name (N);
8210 Rewrite (N, Selector_Name (N));
8213 Set_Etype (Original_Node (N), Id);
8217 -- More than one type derived from Character in given scope.
8218 -- Collect all possible interpretations.
8220 Add_One_Interp (N, Id, Id);
8228 end Has_Implicit_Character_Literal;
8230 ----------------------
8231 -- Has_Private_With --
8232 ----------------------
8234 function Has_Private_With (E : Entity_Id) return Boolean is
8235 Comp_Unit : constant Node_Id := Cunit (Current_Sem_Unit);
8239 Item := First (Context_Items (Comp_Unit));
8240 while Present (Item) loop
8241 if Nkind (Item) = N_With_Clause
8242 and then Private_Present (Item)
8243 and then Entity (Name (Item)) = E
8252 end Has_Private_With;
8254 ---------------------------
8255 -- Has_Implicit_Operator --
8256 ---------------------------
8258 function Has_Implicit_Operator (N : Node_Id) return Boolean is
8259 Op_Id : constant Name_Id := Chars (Selector_Name (N));
8260 P : constant Entity_Id := Entity (Prefix (N));
8262 Priv_Id : Entity_Id := Empty;
8264 procedure Add_Implicit_Operator
8266 Op_Type : Entity_Id := Empty);
8267 -- Add implicit interpretation to node N, using the type for which a
8268 -- predefined operator exists. If the operator yields a boolean type,
8269 -- the Operand_Type is implicitly referenced by the operator, and a
8270 -- reference to it must be generated.
8272 ---------------------------
8273 -- Add_Implicit_Operator --
8274 ---------------------------
8276 procedure Add_Implicit_Operator
8278 Op_Type : Entity_Id := Empty)
8280 Predef_Op : Entity_Id;
8283 Predef_Op := Current_Entity (Selector_Name (N));
8284 while Present (Predef_Op)
8285 and then Scope (Predef_Op) /= Standard_Standard
8287 Predef_Op := Homonym (Predef_Op);
8290 if Nkind (N) = N_Selected_Component then
8291 Change_Selected_Component_To_Expanded_Name (N);
8294 -- If the context is an unanalyzed function call, determine whether
8295 -- a binary or unary interpretation is required.
8297 if Nkind (Parent (N)) = N_Indexed_Component then
8299 Is_Binary_Call : constant Boolean :=
8301 (Next (First (Expressions (Parent (N)))));
8302 Is_Binary_Op : constant Boolean :=
8304 (Predef_Op) /= Last_Entity (Predef_Op);
8305 Predef_Op2 : constant Entity_Id := Homonym (Predef_Op);
8308 if Is_Binary_Call then
8309 if Is_Binary_Op then
8310 Add_One_Interp (N, Predef_Op, T);
8312 Add_One_Interp (N, Predef_Op2, T);
8315 if not Is_Binary_Op then
8316 Add_One_Interp (N, Predef_Op, T);
8318 -- Predef_Op2 may be empty in case of previous errors
8320 elsif Present (Predef_Op2) then
8321 Add_One_Interp (N, Predef_Op2, T);
8327 Add_One_Interp (N, Predef_Op, T);
8329 -- For operators with unary and binary interpretations, if
8330 -- context is not a call, add both
8332 if Present (Homonym (Predef_Op)) then
8333 Add_One_Interp (N, Homonym (Predef_Op), T);
8337 -- The node is a reference to a predefined operator, and
8338 -- an implicit reference to the type of its operands.
8340 if Present (Op_Type) then
8341 Generate_Operator_Reference (N, Op_Type);
8343 Generate_Operator_Reference (N, T);
8345 end Add_Implicit_Operator;
8347 -- Start of processing for Has_Implicit_Operator
8350 if Ekind (P) = E_Package and then not In_Open_Scopes (P) then
8351 Priv_Id := First_Private_Entity (P);
8354 Id := First_Entity (P);
8358 -- Boolean operators: an implicit declaration exists if the scope
8359 -- contains a declaration for a derived Boolean type, or for an
8360 -- array of Boolean type.
8367 while Id /= Priv_Id loop
8368 if Valid_Boolean_Arg (Id) and then Is_Base_Type (Id) then
8369 Add_Implicit_Operator (Id);
8376 -- Equality: look for any non-limited type (result is Boolean)
8381 while Id /= Priv_Id loop
8383 and then not Is_Limited_Type (Id)
8384 and then Is_Base_Type (Id)
8386 Add_Implicit_Operator (Standard_Boolean, Id);
8393 -- Comparison operators: scalar type, or array of scalar
8400 while Id /= Priv_Id loop
8401 if (Is_Scalar_Type (Id)
8402 or else (Is_Array_Type (Id)
8403 and then Is_Scalar_Type (Component_Type (Id))))
8404 and then Is_Base_Type (Id)
8406 Add_Implicit_Operator (Standard_Boolean, Id);
8413 -- Arithmetic operators: any numeric type
8424 while Id /= Priv_Id loop
8425 if Is_Numeric_Type (Id) and then Is_Base_Type (Id) then
8426 Add_Implicit_Operator (Id);
8433 -- Concatenation: any one-dimensional array type
8435 when Name_Op_Concat =>
8436 while Id /= Priv_Id loop
8437 if Is_Array_Type (Id)
8438 and then Number_Dimensions (Id) = 1
8439 and then Is_Base_Type (Id)
8441 Add_Implicit_Operator (Id);
8448 -- What is the others condition here? Should we be using a
8449 -- subtype of Name_Id that would restrict to operators ???
8455 -- If we fall through, then we do not have an implicit operator
8458 end Has_Implicit_Operator;
8460 -----------------------------------
8461 -- Has_Loop_In_Inner_Open_Scopes --
8462 -----------------------------------
8464 function Has_Loop_In_Inner_Open_Scopes (S : Entity_Id) return Boolean is
8466 -- Several scope stacks are maintained by Scope_Stack. The base of the
8467 -- currently active scope stack is denoted by the Is_Active_Stack_Base
8468 -- flag in the scope stack entry. Note that the scope stacks used to
8469 -- simply be delimited implicitly by the presence of Standard_Standard
8470 -- at their base, but there now are cases where this is not sufficient
8471 -- because Standard_Standard actually may appear in the middle of the
8472 -- active set of scopes.
8474 for J in reverse 0 .. Scope_Stack.Last loop
8476 -- S was reached without seing a loop scope first
8478 if Scope_Stack.Table (J).Entity = S then
8481 -- S was not yet reached, so it contains at least one inner loop
8483 elsif Ekind (Scope_Stack.Table (J).Entity) = E_Loop then
8487 -- Check Is_Active_Stack_Base to tell us when to stop, as there are
8488 -- cases where Standard_Standard appears in the middle of the active
8489 -- set of scopes. This affects the declaration and overriding of
8490 -- private inherited operations in instantiations of generic child
8493 pragma Assert (not Scope_Stack.Table (J).Is_Active_Stack_Base);
8496 raise Program_Error; -- unreachable
8497 end Has_Loop_In_Inner_Open_Scopes;
8499 --------------------
8500 -- In_Open_Scopes --
8501 --------------------
8503 function In_Open_Scopes (S : Entity_Id) return Boolean is
8505 -- Several scope stacks are maintained by Scope_Stack. The base of the
8506 -- currently active scope stack is denoted by the Is_Active_Stack_Base
8507 -- flag in the scope stack entry. Note that the scope stacks used to
8508 -- simply be delimited implicitly by the presence of Standard_Standard
8509 -- at their base, but there now are cases where this is not sufficient
8510 -- because Standard_Standard actually may appear in the middle of the
8511 -- active set of scopes.
8513 for J in reverse 0 .. Scope_Stack.Last loop
8514 if Scope_Stack.Table (J).Entity = S then
8518 -- Check Is_Active_Stack_Base to tell us when to stop, as there are
8519 -- cases where Standard_Standard appears in the middle of the active
8520 -- set of scopes. This affects the declaration and overriding of
8521 -- private inherited operations in instantiations of generic child
8524 exit when Scope_Stack.Table (J).Is_Active_Stack_Base;
8530 -----------------------------
8531 -- Inherit_Renamed_Profile --
8532 -----------------------------
8534 procedure Inherit_Renamed_Profile (New_S : Entity_Id; Old_S : Entity_Id) is
8541 if Ekind (Old_S) = E_Operator then
8542 New_F := First_Formal (New_S);
8544 while Present (New_F) loop
8545 Set_Etype (New_F, Base_Type (Etype (New_F)));
8546 Next_Formal (New_F);
8549 Set_Etype (New_S, Base_Type (Etype (New_S)));
8552 New_F := First_Formal (New_S);
8553 Old_F := First_Formal (Old_S);
8555 while Present (New_F) loop
8556 New_T := Etype (New_F);
8557 Old_T := Etype (Old_F);
8559 -- If the new type is a renaming of the old one, as is the case
8560 -- for actuals in instances, retain its name, to simplify later
8563 if Nkind (Parent (New_T)) = N_Subtype_Declaration
8564 and then Is_Entity_Name (Subtype_Indication (Parent (New_T)))
8565 and then Entity (Subtype_Indication (Parent (New_T))) = Old_T
8569 Set_Etype (New_F, Old_T);
8572 Next_Formal (New_F);
8573 Next_Formal (Old_F);
8576 pragma Assert (No (Old_F));
8578 if Ekind (Old_S) in E_Function | E_Enumeration_Literal then
8579 Set_Etype (New_S, Etype (Old_S));
8582 end Inherit_Renamed_Profile;
8588 procedure Initialize is
8593 -------------------------
8594 -- Install_Use_Clauses --
8595 -------------------------
8597 procedure Install_Use_Clauses
8599 Force_Installation : Boolean := False)
8605 while Present (U) loop
8607 -- Case of USE package
8609 if Nkind (U) = N_Use_Package_Clause then
8610 Use_One_Package (U, Name (U), True);
8615 Use_One_Type (Subtype_Mark (U), Force => Force_Installation);
8619 Next_Use_Clause (U);
8621 end Install_Use_Clauses;
8623 ----------------------
8624 -- Mark_Use_Clauses --
8625 ----------------------
8627 procedure Mark_Use_Clauses (Id : Node_Or_Entity_Id) is
8628 procedure Mark_Parameters (Call : Entity_Id);
8629 -- Perform use_type_clause marking for all parameters in a subprogram
8630 -- or operator call.
8632 procedure Mark_Use_Package (Pak : Entity_Id);
8633 -- Move up the Prev_Use_Clause chain for packages denoted by Pak -
8634 -- marking each clause in the chain as effective in the process.
8636 procedure Mark_Use_Type (E : Entity_Id);
8637 -- Similar to Do_Use_Package_Marking except we move up the
8638 -- Prev_Use_Clause chain for the type denoted by E.
8640 ---------------------
8641 -- Mark_Parameters --
8642 ---------------------
8644 procedure Mark_Parameters (Call : Entity_Id) is
8648 -- Move through all of the formals
8650 Curr := First_Formal (Call);
8651 while Present (Curr) loop
8652 Mark_Use_Type (Curr);
8657 -- Handle the return type
8659 Mark_Use_Type (Call);
8660 end Mark_Parameters;
8662 ----------------------
8663 -- Mark_Use_Package --
8664 ----------------------
8666 procedure Mark_Use_Package (Pak : Entity_Id) is
8670 -- Ignore cases where the scope of the type is not a package (e.g.
8671 -- Standard_Standard).
8673 if Ekind (Pak) /= E_Package then
8677 Curr := Current_Use_Clause (Pak);
8678 while Present (Curr)
8679 and then not Is_Effective_Use_Clause (Curr)
8681 -- We need to mark the previous use clauses as effective, but
8682 -- each use clause may in turn render other use_package_clauses
8683 -- effective. Additionally, it is possible to have a parent
8684 -- package renamed as a child of itself so we must check the
8685 -- prefix entity is not the same as the package we are marking.
8687 if Nkind (Name (Curr)) /= N_Identifier
8688 and then Present (Prefix (Name (Curr)))
8689 and then Entity (Prefix (Name (Curr))) /= Pak
8691 Mark_Use_Package (Entity (Prefix (Name (Curr))));
8693 -- It is also possible to have a child package without a prefix
8694 -- that relies on a previous use_package_clause.
8696 elsif Nkind (Name (Curr)) = N_Identifier
8697 and then Is_Child_Unit (Entity (Name (Curr)))
8699 Mark_Use_Package (Scope (Entity (Name (Curr))));
8702 -- Mark the use_package_clause as effective and move up the chain
8704 Set_Is_Effective_Use_Clause (Curr);
8706 Curr := Prev_Use_Clause (Curr);
8708 end Mark_Use_Package;
8714 procedure Mark_Use_Type (E : Entity_Id) is
8719 -- Ignore void types and unresolved string literals and primitives
8721 if Nkind (E) = N_String_Literal
8722 or else Nkind (Etype (E)) not in N_Entity
8723 or else not Is_Type (Etype (E))
8728 -- Primitives with class-wide operands might additionally render
8729 -- their base type's use_clauses effective - so do a recursive check
8732 Base := Base_Type (Etype (E));
8734 if Ekind (Base) = E_Class_Wide_Type then
8735 Mark_Use_Type (Base);
8738 -- The package containing the type or operator function being used
8739 -- may be in use as well, so mark any use_package_clauses for it as
8740 -- effective. There are also additional sanity checks performed here
8741 -- for ignoring previous errors.
8743 Mark_Use_Package (Scope (Base));
8745 if Nkind (E) in N_Op
8746 and then Present (Entity (E))
8747 and then Present (Scope (Entity (E)))
8749 Mark_Use_Package (Scope (Entity (E)));
8752 Curr := Current_Use_Clause (Base);
8753 while Present (Curr)
8754 and then not Is_Effective_Use_Clause (Curr)
8756 -- Current use_type_clause may render other use_package_clauses
8759 if Nkind (Subtype_Mark (Curr)) /= N_Identifier
8760 and then Present (Prefix (Subtype_Mark (Curr)))
8762 Mark_Use_Package (Entity (Prefix (Subtype_Mark (Curr))));
8765 -- Mark the use_type_clause as effective and move up the chain
8767 Set_Is_Effective_Use_Clause (Curr);
8769 Curr := Prev_Use_Clause (Curr);
8773 -- Start of processing for Mark_Use_Clauses
8776 -- Use clauses in and of themselves do not count as a "use" of a
8779 if Nkind (Parent (Id)) in N_Use_Package_Clause | N_Use_Type_Clause then
8785 if Nkind (Id) in N_Entity then
8787 -- Mark the entity's package
8789 if Is_Potentially_Use_Visible (Id) then
8790 Mark_Use_Package (Scope (Id));
8793 -- Mark enumeration literals
8795 if Ekind (Id) = E_Enumeration_Literal then
8800 elsif (Is_Overloadable (Id)
8801 or else Is_Generic_Subprogram (Id))
8802 and then (Is_Potentially_Use_Visible (Id)
8803 or else Is_Intrinsic_Subprogram (Id)
8804 or else (Ekind (Id) in E_Function | E_Procedure
8805 and then Is_Generic_Actual_Subprogram (Id)))
8807 Mark_Parameters (Id);
8815 if Nkind (Id) in N_Op then
8817 -- At this point the left operand may not be resolved if we are
8818 -- encountering multiple operators next to eachother in an
8821 if Nkind (Id) in N_Binary_Op
8822 and then not (Nkind (Left_Opnd (Id)) in N_Op)
8824 Mark_Use_Type (Left_Opnd (Id));
8827 Mark_Use_Type (Right_Opnd (Id));
8830 -- Mark entity identifiers
8832 elsif Nkind (Id) in N_Has_Entity
8833 and then (Is_Potentially_Use_Visible (Entity (Id))
8834 or else (Is_Generic_Instance (Entity (Id))
8835 and then Is_Immediately_Visible (Entity (Id))))
8837 -- Ignore fully qualified names as they do not count as a "use" of
8840 if Nkind (Id) in N_Identifier | N_Operator_Symbol
8841 or else (Present (Prefix (Id))
8842 and then Scope (Entity (Id)) /= Entity (Prefix (Id)))
8844 Mark_Use_Clauses (Entity (Id));
8848 end Mark_Use_Clauses;
8850 --------------------------------
8851 -- Most_Descendant_Use_Clause --
8852 --------------------------------
8854 function Most_Descendant_Use_Clause
8855 (Clause1 : Entity_Id;
8856 Clause2 : Entity_Id) return Entity_Id
8862 if Clause1 = Clause2 then
8866 -- We determine which one is the most descendant by the scope distance
8867 -- to the ultimate parent unit.
8869 Scope1 := Entity_Of_Unit (Unit (Parent (Clause1)));
8870 Scope2 := Entity_Of_Unit (Unit (Parent (Clause2)));
8871 while Scope1 /= Standard_Standard
8872 and then Scope2 /= Standard_Standard
8874 Scope1 := Scope (Scope1);
8875 Scope2 := Scope (Scope2);
8877 if not Present (Scope1) then
8879 elsif not Present (Scope2) then
8884 if Scope1 = Standard_Standard then
8889 end Most_Descendant_Use_Clause;
8895 procedure Pop_Scope is
8896 SST : Scope_Stack_Entry renames Scope_Stack.Table (Scope_Stack.Last);
8897 S : constant Entity_Id := SST.Entity;
8900 if Debug_Flag_E then
8904 -- Set Default_Storage_Pool field of the library unit if necessary
8906 if Is_Package_Or_Generic_Package (S)
8908 Nkind (Parent (Unit_Declaration_Node (S))) = N_Compilation_Unit
8911 Aux : constant Node_Id :=
8912 Aux_Decls_Node (Parent (Unit_Declaration_Node (S)));
8914 if No (Default_Storage_Pool (Aux)) then
8915 Set_Default_Storage_Pool (Aux, Default_Pool);
8920 Scope_Suppress := SST.Save_Scope_Suppress;
8921 Local_Suppress_Stack_Top := SST.Save_Local_Suppress_Stack_Top;
8922 Check_Policy_List := SST.Save_Check_Policy_List;
8923 Default_Pool := SST.Save_Default_Storage_Pool;
8924 No_Tagged_Streams := SST.Save_No_Tagged_Streams;
8925 SPARK_Mode := SST.Save_SPARK_Mode;
8926 SPARK_Mode_Pragma := SST.Save_SPARK_Mode_Pragma;
8927 Default_SSO := SST.Save_Default_SSO;
8928 Uneval_Old := SST.Save_Uneval_Old;
8930 if Debug_Flag_W then
8931 Write_Str ("<-- exiting scope: ");
8932 Write_Name (Chars (Current_Scope));
8933 Write_Str (", Depth=");
8934 Write_Int (Int (Scope_Stack.Last));
8938 End_Use_Clauses (SST.First_Use_Clause);
8940 -- If the actions to be wrapped are still there they will get lost
8941 -- causing incomplete code to be generated. It is better to abort in
8942 -- this case (and we do the abort even with assertions off since the
8943 -- penalty is incorrect code generation).
8945 if SST.Actions_To_Be_Wrapped /= Scope_Actions'(others => No_List) then
8946 raise Program_Error;
8949 -- Free last subprogram name if allocated, and pop scope
8951 Free (SST.Last_Subprogram_Name);
8952 Scope_Stack.Decrement_Last;
8959 procedure Push_Scope (S : Entity_Id) is
8960 E : constant Entity_Id := Scope (S);
8963 if Ekind (S) = E_Void then
8966 -- Set scope depth if not a non-concurrent type, and we have not yet set
8967 -- the scope depth. This means that we have the first occurrence of the
8968 -- scope, and this is where the depth is set.
8970 elsif (not Is_Type (S) or else Is_Concurrent_Type (S))
8971 and then not Scope_Depth_Set (S)
8973 if S = Standard_Standard then
8974 Set_Scope_Depth_Value (S, Uint_0);
8976 elsif Is_Child_Unit (S) then
8977 Set_Scope_Depth_Value (S, Uint_1);
8979 elsif not Is_Record_Type (Current_Scope) then
8980 if Ekind (S) = E_Loop then
8981 Set_Scope_Depth_Value (S, Scope_Depth (Current_Scope));
8983 Set_Scope_Depth_Value (S, Scope_Depth (Current_Scope) + 1);
8988 Scope_Stack.Increment_Last;
8991 SST : Scope_Stack_Entry renames Scope_Stack.Table (Scope_Stack.Last);
8995 SST.Save_Scope_Suppress := Scope_Suppress;
8996 SST.Save_Local_Suppress_Stack_Top := Local_Suppress_Stack_Top;
8997 SST.Save_Check_Policy_List := Check_Policy_List;
8998 SST.Save_Default_Storage_Pool := Default_Pool;
8999 SST.Save_No_Tagged_Streams := No_Tagged_Streams;
9000 SST.Save_SPARK_Mode := SPARK_Mode;
9001 SST.Save_SPARK_Mode_Pragma := SPARK_Mode_Pragma;
9002 SST.Save_Default_SSO := Default_SSO;
9003 SST.Save_Uneval_Old := Uneval_Old;
9005 -- Each new scope pushed onto the scope stack inherits the component
9006 -- alignment of the previous scope. This emulates the "visibility"
9007 -- semantics of pragma Component_Alignment.
9009 if Scope_Stack.Last > Scope_Stack.First then
9010 SST.Component_Alignment_Default :=
9012 (Scope_Stack.Last - 1).Component_Alignment_Default;
9014 -- Otherwise, this is the first scope being pushed on the scope
9015 -- stack. Inherit the component alignment from the configuration
9016 -- form of pragma Component_Alignment (if any).
9019 SST.Component_Alignment_Default :=
9020 Configuration_Component_Alignment;
9023 SST.Last_Subprogram_Name := null;
9024 SST.Is_Transient := False;
9025 SST.Node_To_Be_Wrapped := Empty;
9026 SST.Pending_Freeze_Actions := No_List;
9027 SST.Actions_To_Be_Wrapped := (others => No_List);
9028 SST.First_Use_Clause := Empty;
9029 SST.Is_Active_Stack_Base := False;
9030 SST.Previous_Visibility := False;
9031 SST.Locked_Shared_Objects := No_Elist;
9034 if Debug_Flag_W then
9035 Write_Str ("--> new scope: ");
9036 Write_Name (Chars (Current_Scope));
9037 Write_Str (", Id=");
9038 Write_Int (Int (Current_Scope));
9039 Write_Str (", Depth=");
9040 Write_Int (Int (Scope_Stack.Last));
9044 -- Deal with copying flags from the previous scope to this one. This is
9045 -- not necessary if either scope is standard, or if the new scope is a
9048 if S /= Standard_Standard
9049 and then Scope (S) /= Standard_Standard
9050 and then not Is_Child_Unit (S)
9052 if Nkind (E) not in N_Entity then
9056 -- Copy categorization flags from Scope (S) to S, this is not done
9057 -- when Scope (S) is Standard_Standard since propagation is from
9058 -- library unit entity inwards. Copy other relevant attributes as
9059 -- well (Discard_Names in particular).
9061 -- We only propagate inwards for library level entities,
9062 -- inner level subprograms do not inherit the categorization.
9064 if Is_Library_Level_Entity (S) then
9065 Set_Is_Preelaborated (S, Is_Preelaborated (E));
9066 Set_Is_Shared_Passive (S, Is_Shared_Passive (E));
9067 Set_Discard_Names (S, Discard_Names (E));
9068 Set_Suppress_Value_Tracking_On_Call
9069 (S, Suppress_Value_Tracking_On_Call (E));
9070 Set_Categorization_From_Scope (E => S, Scop => E);
9074 if Is_Child_Unit (S)
9075 and then Present (E)
9076 and then Is_Package_Or_Generic_Package (E)
9078 Nkind (Parent (Unit_Declaration_Node (E))) = N_Compilation_Unit
9081 Aux : constant Node_Id :=
9082 Aux_Decls_Node (Parent (Unit_Declaration_Node (E)));
9084 if Present (Default_Storage_Pool (Aux)) then
9085 Default_Pool := Default_Storage_Pool (Aux);
9091 ---------------------
9092 -- Premature_Usage --
9093 ---------------------
9095 procedure Premature_Usage (N : Node_Id) is
9096 Kind : constant Node_Kind := Nkind (Parent (Entity (N)));
9097 E : Entity_Id := Entity (N);
9100 -- Within an instance, the analysis of the actual for a formal object
9101 -- does not see the name of the object itself. This is significant only
9102 -- if the object is an aggregate, where its analysis does not do any
9103 -- name resolution on component associations. (see 4717-008). In such a
9104 -- case, look for the visible homonym on the chain.
9106 if In_Instance and then Present (Homonym (E)) then
9108 while Present (E) and then not In_Open_Scopes (Scope (E)) loop
9114 Set_Etype (N, Etype (E));
9120 when N_Component_Declaration =>
9122 ("component&! cannot be used before end of record declaration",
9125 when N_Parameter_Specification =>
9127 ("formal parameter&! cannot be used before end of specification",
9130 when N_Discriminant_Specification =>
9132 ("discriminant&! cannot be used before end of discriminant part",
9135 when N_Procedure_Specification | N_Function_Specification =>
9137 ("subprogram&! cannot be used before end of its declaration",
9140 when N_Full_Type_Declaration | N_Subtype_Declaration =>
9142 ("type& cannot be used before end of its declaration!", N);
9146 ("object& cannot be used before end of its declaration!", N);
9148 -- If the premature reference appears as the expression in its own
9149 -- declaration, rewrite it to prevent compiler loops in subsequent
9150 -- uses of this mangled declaration in address clauses.
9152 if Nkind (Parent (N)) = N_Object_Declaration then
9153 Set_Entity (N, Any_Id);
9156 end Premature_Usage;
9158 ------------------------
9159 -- Present_System_Aux --
9160 ------------------------
9162 function Present_System_Aux (N : Node_Id := Empty) return Boolean is
9164 Aux_Name : Unit_Name_Type;
9165 Unum : Unit_Number_Type;
9170 function Find_System (C_Unit : Node_Id) return Entity_Id;
9171 -- Scan context clause of compilation unit to find with_clause
9178 function Find_System (C_Unit : Node_Id) return Entity_Id is
9179 With_Clause : Node_Id;
9182 With_Clause := First (Context_Items (C_Unit));
9183 while Present (With_Clause) loop
9184 if (Nkind (With_Clause) = N_With_Clause
9185 and then Chars (Name (With_Clause)) = Name_System)
9186 and then Comes_From_Source (With_Clause)
9197 -- Start of processing for Present_System_Aux
9200 -- The child unit may have been loaded and analyzed already
9202 if Present (System_Aux_Id) then
9205 -- If no previous pragma for System.Aux, nothing to load
9207 elsif No (System_Extend_Unit) then
9210 -- Use the unit name given in the pragma to retrieve the unit.
9211 -- Verify that System itself appears in the context clause of the
9212 -- current compilation. If System is not present, an error will
9213 -- have been reported already.
9216 With_Sys := Find_System (Cunit (Current_Sem_Unit));
9218 The_Unit := Unit (Cunit (Current_Sem_Unit));
9222 (Nkind (The_Unit) = N_Package_Body
9223 or else (Nkind (The_Unit) = N_Subprogram_Body
9224 and then not Acts_As_Spec (Cunit (Current_Sem_Unit))))
9226 With_Sys := Find_System (Library_Unit (Cunit (Current_Sem_Unit)));
9229 if No (With_Sys) and then Present (N) then
9231 -- If we are compiling a subunit, we need to examine its
9232 -- context as well (Current_Sem_Unit is the parent unit);
9234 The_Unit := Parent (N);
9235 while Nkind (The_Unit) /= N_Compilation_Unit loop
9236 The_Unit := Parent (The_Unit);
9239 if Nkind (Unit (The_Unit)) = N_Subunit then
9240 With_Sys := Find_System (The_Unit);
9244 if No (With_Sys) then
9248 Loc := Sloc (With_Sys);
9249 Get_Name_String (Chars (Expression (System_Extend_Unit)));
9250 Name_Buffer (8 .. Name_Len + 7) := Name_Buffer (1 .. Name_Len);
9251 Name_Buffer (1 .. 7) := "system.";
9252 Name_Buffer (Name_Len + 8) := '%';
9253 Name_Buffer (Name_Len + 9) := 's';
9254 Name_Len := Name_Len + 9;
9255 Aux_Name := Name_Find;
9259 (Load_Name => Aux_Name,
9262 Error_Node => With_Sys);
9264 if Unum /= No_Unit then
9265 Semantics (Cunit (Unum));
9267 Defining_Entity (Specification (Unit (Cunit (Unum))));
9270 Make_With_Clause (Loc,
9272 Make_Expanded_Name (Loc,
9273 Chars => Chars (System_Aux_Id),
9275 New_Occurrence_Of (Scope (System_Aux_Id), Loc),
9276 Selector_Name => New_Occurrence_Of (System_Aux_Id, Loc)));
9278 Set_Entity (Name (Withn), System_Aux_Id);
9280 Set_Corresponding_Spec (Withn, System_Aux_Id);
9281 Set_First_Name (Withn);
9282 Set_Implicit_With (Withn);
9283 Set_Library_Unit (Withn, Cunit (Unum));
9285 Insert_After (With_Sys, Withn);
9286 Mark_Rewrite_Insertion (Withn);
9287 Set_Context_Installed (Withn);
9291 -- Here if unit load failed
9294 Error_Msg_Name_1 := Name_System;
9295 Error_Msg_Name_2 := Chars (Expression (System_Extend_Unit));
9297 ("extension package `%.%` does not exist",
9298 Opt.System_Extend_Unit);
9302 end Present_System_Aux;
9304 -------------------------
9305 -- Restore_Scope_Stack --
9306 -------------------------
9308 procedure Restore_Scope_Stack
9310 Handle_Use : Boolean := True)
9312 SS_Last : constant Int := Scope_Stack.Last;
9316 -- Restore visibility of previous scope stack, if any, using the list
9317 -- we saved (we use Remove, since this list will not be used again).
9320 Elmt := Last_Elmt (List);
9321 exit when Elmt = No_Elmt;
9322 Set_Is_Immediately_Visible (Node (Elmt));
9323 Remove_Last_Elmt (List);
9326 -- Restore use clauses
9328 if SS_Last >= Scope_Stack.First
9329 and then Scope_Stack.Table (SS_Last).Entity /= Standard_Standard
9333 (Scope_Stack.Table (SS_Last).First_Use_Clause,
9334 Force_Installation => True);
9336 end Restore_Scope_Stack;
9338 ----------------------
9339 -- Save_Scope_Stack --
9340 ----------------------
9342 -- Save_Scope_Stack/Restore_Scope_Stack were originally designed to avoid
9343 -- consuming any memory. That is, Save_Scope_Stack took care of removing
9344 -- from immediate visibility entities and Restore_Scope_Stack took care
9345 -- of restoring their visibility analyzing the context of each entity. The
9346 -- problem of such approach is that it was fragile and caused unexpected
9347 -- visibility problems, and indeed one test was found where there was a
9350 -- Furthermore, the following experiment was carried out:
9352 -- - Save_Scope_Stack was modified to store in an Elist1 all those
9353 -- entities whose attribute Is_Immediately_Visible is modified
9354 -- from True to False.
9356 -- - Restore_Scope_Stack was modified to store in another Elist2
9357 -- all the entities whose attribute Is_Immediately_Visible is
9358 -- modified from False to True.
9360 -- - Extra code was added to verify that all the elements of Elist1
9361 -- are found in Elist2
9363 -- This test shows that there may be more occurrences of this problem which
9364 -- have not yet been detected. As a result, we replaced that approach by
9365 -- the current one in which Save_Scope_Stack returns the list of entities
9366 -- whose visibility is changed, and that list is passed to Restore_Scope_
9367 -- Stack to undo that change. This approach is simpler and safer, although
9368 -- it consumes more memory.
9370 function Save_Scope_Stack (Handle_Use : Boolean := True) return Elist_Id is
9371 Result : constant Elist_Id := New_Elmt_List;
9374 SS_Last : constant Int := Scope_Stack.Last;
9376 procedure Remove_From_Visibility (E : Entity_Id);
9377 -- If E is immediately visible then append it to the result and remove
9378 -- it temporarily from visibility.
9380 ----------------------------
9381 -- Remove_From_Visibility --
9382 ----------------------------
9384 procedure Remove_From_Visibility (E : Entity_Id) is
9386 if Is_Immediately_Visible (E) then
9387 Append_Elmt (E, Result);
9388 Set_Is_Immediately_Visible (E, False);
9390 end Remove_From_Visibility;
9392 -- Start of processing for Save_Scope_Stack
9395 if SS_Last >= Scope_Stack.First
9396 and then Scope_Stack.Table (SS_Last).Entity /= Standard_Standard
9399 End_Use_Clauses (Scope_Stack.Table (SS_Last).First_Use_Clause);
9402 -- If the call is from within a compilation unit, as when called from
9403 -- Rtsfind, make current entries in scope stack invisible while we
9404 -- analyze the new unit.
9406 for J in reverse 0 .. SS_Last loop
9407 exit when Scope_Stack.Table (J).Entity = Standard_Standard
9408 or else No (Scope_Stack.Table (J).Entity);
9410 S := Scope_Stack.Table (J).Entity;
9412 Remove_From_Visibility (S);
9414 E := First_Entity (S);
9415 while Present (E) loop
9416 Remove_From_Visibility (E);
9424 end Save_Scope_Stack;
9430 procedure Set_Use (L : List_Id) is
9436 while Present (Decl) loop
9437 if Nkind (Decl) = N_Use_Package_Clause then
9438 Chain_Use_Clause (Decl);
9439 Use_One_Package (Decl, Name (Decl));
9441 elsif Nkind (Decl) = N_Use_Type_Clause then
9442 Chain_Use_Clause (Decl);
9443 Use_One_Type (Subtype_Mark (Decl));
9452 -----------------------------
9453 -- Update_Use_Clause_Chain --
9454 -----------------------------
9456 procedure Update_Use_Clause_Chain is
9458 procedure Update_Chain_In_Scope (Level : Int);
9459 -- Iterate through one level in the scope stack verifying each use-type
9460 -- clause within said level is used then reset the Current_Use_Clause
9461 -- to a redundant use clause outside of the current ending scope if such
9464 ---------------------------
9465 -- Update_Chain_In_Scope --
9466 ---------------------------
9468 procedure Update_Chain_In_Scope (Level : Int) is
9473 -- Loop through all use clauses within the scope dictated by Level
9475 Curr := Scope_Stack.Table (Level).First_Use_Clause;
9476 while Present (Curr) loop
9478 -- Retrieve the subtype mark or name within the current current
9481 if Nkind (Curr) = N_Use_Type_Clause then
9482 N := Subtype_Mark (Curr);
9487 -- If warnings for unreferenced entities are enabled and the
9488 -- current use clause has not been marked effective.
9490 if Check_Unreferenced
9491 and then Comes_From_Source (Curr)
9492 and then not Is_Effective_Use_Clause (Curr)
9493 and then not In_Instance
9494 and then not In_Inlined_Body
9496 -- We are dealing with a potentially unused use_package_clause
9498 if Nkind (Curr) = N_Use_Package_Clause then
9500 -- Renamings and formal subprograms may cause the associated
9501 -- node to be marked as effective instead of the original.
9503 if not (Present (Associated_Node (N))
9506 (Associated_Node (N)))
9507 and then Is_Effective_Use_Clause
9509 (Associated_Node (N))))
9511 Error_Msg_Node_1 := Entity (N);
9513 ("use clause for package & has no effect?u?",
9517 -- We are dealing with an unused use_type_clause
9520 Error_Msg_Node_1 := Etype (N);
9522 ("use clause for } has no effect?u?", Curr, Etype (N));
9526 -- Verify that we haven't already processed a redundant
9527 -- use_type_clause within the same scope before we move the
9528 -- current use clause up to a previous one for type T.
9530 if Present (Prev_Use_Clause (Curr)) then
9531 Set_Current_Use_Clause (Entity (N), Prev_Use_Clause (Curr));
9534 Next_Use_Clause (Curr);
9536 end Update_Chain_In_Scope;
9538 -- Start of processing for Update_Use_Clause_Chain
9541 Update_Chain_In_Scope (Scope_Stack.Last);
9543 -- Deal with use clauses within the context area if the current
9544 -- scope is a compilation unit.
9546 if Is_Compilation_Unit (Current_Scope)
9547 and then Sloc (Scope_Stack.Table
9548 (Scope_Stack.Last - 1).Entity) = Standard_Location
9550 Update_Chain_In_Scope (Scope_Stack.Last - 1);
9552 end Update_Use_Clause_Chain;
9554 ---------------------
9555 -- Use_One_Package --
9556 ---------------------
9558 procedure Use_One_Package
9560 Pack_Name : Entity_Id := Empty;
9561 Force : Boolean := False)
9563 procedure Note_Redundant_Use (Clause : Node_Id);
9564 -- Mark the name in a use clause as redundant if the corresponding
9565 -- entity is already use-visible. Emit a warning if the use clause comes
9566 -- from source and the proper warnings are enabled.
9568 ------------------------
9569 -- Note_Redundant_Use --
9570 ------------------------
9572 procedure Note_Redundant_Use (Clause : Node_Id) is
9573 Decl : constant Node_Id := Parent (Clause);
9574 Pack_Name : constant Entity_Id := Entity (Clause);
9576 Cur_Use : Node_Id := Current_Use_Clause (Pack_Name);
9577 Prev_Use : Node_Id := Empty;
9578 Redundant : Node_Id := Empty;
9579 -- The Use_Clause which is actually redundant. In the simplest case
9580 -- it is Pack itself, but when we compile a body we install its
9581 -- context before that of its spec, in which case it is the
9582 -- use_clause in the spec that will appear to be redundant, and we
9583 -- want the warning to be placed on the body. Similar complications
9584 -- appear when the redundancy is between a child unit and one of its
9588 -- Could be renamed...
9590 if No (Cur_Use) then
9591 Cur_Use := Current_Use_Clause (Renamed_Entity (Pack_Name));
9594 Set_Redundant_Use (Clause, True);
9596 -- Do not check for redundant use if clause is generated, or in an
9597 -- instance, or in a predefined unit to avoid misleading warnings
9598 -- that may occur as part of a rtsfind load.
9600 if not Comes_From_Source (Clause)
9602 or else not Warn_On_Redundant_Constructs
9603 or else Is_Predefined_Unit (Current_Sem_Unit)
9608 if not Is_Compilation_Unit (Current_Scope) then
9610 -- If the use_clause is in an inner scope, it is made redundant by
9611 -- some clause in the current context, with one exception: If we
9612 -- are compiling a nested package body, and the use_clause comes
9613 -- from then corresponding spec, the clause is not necessarily
9614 -- fully redundant, so we should not warn. If a warning was
9615 -- warranted, it would have been given when the spec was
9618 if Nkind (Parent (Decl)) = N_Package_Specification then
9620 Package_Spec_Entity : constant Entity_Id :=
9621 Defining_Unit_Name (Parent (Decl));
9623 if In_Package_Body (Package_Spec_Entity) then
9629 Redundant := Clause;
9630 Prev_Use := Cur_Use;
9632 elsif Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Body then
9634 Cur_Unit : constant Unit_Number_Type :=
9635 Get_Source_Unit (Cur_Use);
9636 New_Unit : constant Unit_Number_Type :=
9637 Get_Source_Unit (Clause);
9642 if Cur_Unit = New_Unit then
9644 -- Redundant clause in same body
9646 Redundant := Clause;
9647 Prev_Use := Cur_Use;
9649 elsif Cur_Unit = Current_Sem_Unit then
9651 -- If the new clause is not in the current unit it has been
9652 -- analyzed first, and it makes the other one redundant.
9653 -- However, if the new clause appears in a subunit, Cur_Unit
9654 -- is still the parent, and in that case the redundant one
9655 -- is the one appearing in the subunit.
9657 if Nkind (Unit (Cunit (New_Unit))) = N_Subunit then
9658 Redundant := Clause;
9659 Prev_Use := Cur_Use;
9661 -- Most common case: redundant clause in body, original
9662 -- clause in spec. Current scope is spec entity.
9664 elsif Current_Scope = Cunit_Entity (Current_Sem_Unit) then
9665 Redundant := Cur_Use;
9669 -- The new clause may appear in an unrelated unit, when
9670 -- the parents of a generic are being installed prior to
9671 -- instantiation. In this case there must be no warning.
9672 -- We detect this case by checking whether the current
9673 -- top of the stack is related to the current
9676 Scop := Current_Scope;
9677 while Present (Scop)
9678 and then Scop /= Standard_Standard
9680 if Is_Compilation_Unit (Scop)
9681 and then not Is_Child_Unit (Scop)
9685 elsif Scop = Cunit_Entity (Current_Sem_Unit) then
9689 Scop := Scope (Scop);
9692 Redundant := Cur_Use;
9696 elsif New_Unit = Current_Sem_Unit then
9697 Redundant := Clause;
9698 Prev_Use := Cur_Use;
9701 -- Neither is the current unit, so they appear in parent or
9702 -- sibling units. Warning will be emitted elsewhere.
9708 elsif Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Declaration
9709 and then Present (Parent_Spec (Unit (Cunit (Current_Sem_Unit))))
9711 -- Use_clause is in child unit of current unit, and the child unit
9712 -- appears in the context of the body of the parent, so it has
9713 -- been installed first, even though it is the redundant one.
9714 -- Depending on their placement in the context, the visible or the
9715 -- private parts of the two units, either might appear as
9716 -- redundant, but the message has to be on the current unit.
9718 if Get_Source_Unit (Cur_Use) = Current_Sem_Unit then
9719 Redundant := Cur_Use;
9722 Redundant := Clause;
9723 Prev_Use := Cur_Use;
9726 -- If the new use clause appears in the private part of a parent
9727 -- unit it may appear to be redundant w.r.t. a use clause in a
9728 -- child unit, but the previous use clause was needed in the
9729 -- visible part of the child, and no warning should be emitted.
9731 if Nkind (Parent (Decl)) = N_Package_Specification
9732 and then List_Containing (Decl) =
9733 Private_Declarations (Parent (Decl))
9736 Par : constant Entity_Id :=
9737 Defining_Entity (Parent (Decl));
9738 Spec : constant Node_Id :=
9739 Specification (Unit (Cunit (Current_Sem_Unit)));
9740 Cur_List : constant List_Id := List_Containing (Cur_Use);
9743 if Is_Compilation_Unit (Par)
9744 and then Par /= Cunit_Entity (Current_Sem_Unit)
9746 if Cur_List = Context_Items (Cunit (Current_Sem_Unit))
9747 or else Cur_List = Visible_Declarations (Spec)
9755 -- Finally, if the current use clause is in the context then the
9756 -- clause is redundant when it is nested within the unit.
9758 elsif Nkind (Parent (Cur_Use)) = N_Compilation_Unit
9759 and then Nkind (Parent (Parent (Clause))) /= N_Compilation_Unit
9760 and then Get_Source_Unit (Cur_Use) = Get_Source_Unit (Clause)
9762 Redundant := Clause;
9763 Prev_Use := Cur_Use;
9766 if Present (Redundant) and then Parent (Redundant) /= Prev_Use then
9768 -- Make sure we are looking at most-descendant use_package_clause
9769 -- by traversing the chain with Find_Most_Prev and then verifying
9770 -- there is no scope manipulation via Most_Descendant_Use_Clause.
9772 if Nkind (Prev_Use) = N_Use_Package_Clause
9774 (Nkind (Parent (Prev_Use)) /= N_Compilation_Unit
9775 or else Most_Descendant_Use_Clause
9776 (Prev_Use, Find_Most_Prev (Prev_Use)) /= Prev_Use)
9778 Prev_Use := Find_Most_Prev (Prev_Use);
9781 Error_Msg_Sloc := Sloc (Prev_Use);
9782 Error_Msg_NE -- CODEFIX
9783 ("& is already use-visible through previous use_clause #?r?",
9784 Redundant, Pack_Name);
9786 end Note_Redundant_Use;
9790 Current_Instance : Entity_Id := Empty;
9794 Private_With_OK : Boolean := False;
9797 -- Start of processing for Use_One_Package
9800 -- Use_One_Package may have been called recursively to handle an
9801 -- implicit use for a auxiliary system package, so set P accordingly
9802 -- and skip redundancy checks.
9804 if No (Pack_Name) and then Present_System_Aux (N) then
9807 -- Check for redundant use_package_clauses
9810 -- Ignore cases where we are dealing with a non user defined package
9811 -- like Standard_Standard or something other than a valid package.
9813 if not Is_Entity_Name (Pack_Name)
9814 or else No (Entity (Pack_Name))
9815 or else Ekind (Entity (Pack_Name)) /= E_Package
9820 -- When a renaming exists we must check it for redundancy. The
9821 -- original package would have already been seen at this point.
9823 if Present (Renamed_Object (Entity (Pack_Name))) then
9824 P := Renamed_Object (Entity (Pack_Name));
9826 P := Entity (Pack_Name);
9829 -- Check for redundant clauses then set the current use clause for
9830 -- P if were are not "forcing" an installation from a scope
9831 -- reinstallation that is done throughout analysis for various
9835 Note_Redundant_Use (Pack_Name);
9838 Set_Current_Use_Clause (P, N);
9843 -- Warn about detected redundant clauses
9846 and then In_Open_Scopes (P)
9847 and then not Is_Hidden_Open_Scope (P)
9849 if Warn_On_Redundant_Constructs and then P = Current_Scope then
9850 Error_Msg_NE -- CODEFIX
9851 ("& is already use-visible within itself?r?",
9858 -- Set P back to the non-renamed package so that visiblilty of the
9859 -- entities within the package can be properly set below.
9861 P := Entity (Pack_Name);
9865 Set_Current_Use_Clause (P, N);
9867 -- Ada 2005 (AI-50217): Check restriction
9869 if From_Limited_With (P) then
9870 Error_Msg_N ("limited withed package cannot appear in use clause", N);
9873 -- Find enclosing instance, if any
9876 Current_Instance := Current_Scope;
9877 while not Is_Generic_Instance (Current_Instance) loop
9878 Current_Instance := Scope (Current_Instance);
9881 if No (Hidden_By_Use_Clause (N)) then
9882 Set_Hidden_By_Use_Clause (N, New_Elmt_List);
9886 -- If unit is a package renaming, indicate that the renamed package is
9887 -- also in use (the flags on both entities must remain consistent, and a
9888 -- subsequent use of either of them should be recognized as redundant).
9890 if Present (Renamed_Object (P)) then
9891 Set_In_Use (Renamed_Object (P));
9892 Set_Current_Use_Clause (Renamed_Object (P), N);
9893 Real_P := Renamed_Object (P);
9898 -- Ada 2005 (AI-262): Check the use_clause of a private withed package
9899 -- found in the private part of a package specification
9901 if In_Private_Part (Current_Scope)
9902 and then Has_Private_With (P)
9903 and then Is_Child_Unit (Current_Scope)
9904 and then Is_Child_Unit (P)
9905 and then Is_Ancestor_Package (Scope (Current_Scope), P)
9907 Private_With_OK := True;
9910 -- Loop through entities in one package making them potentially
9913 Id := First_Entity (P);
9915 and then (Id /= First_Private_Entity (P)
9916 or else Private_With_OK) -- Ada 2005 (AI-262)
9918 Prev := Current_Entity (Id);
9919 while Present (Prev) loop
9920 if Is_Immediately_Visible (Prev)
9921 and then (not Is_Overloadable (Prev)
9922 or else not Is_Overloadable (Id)
9923 or else (Type_Conformant (Id, Prev)))
9925 if No (Current_Instance) then
9927 -- Potentially use-visible entity remains hidden
9929 goto Next_Usable_Entity;
9931 -- A use clause within an instance hides outer global entities,
9932 -- which are not used to resolve local entities in the
9933 -- instance. Note that the predefined entities in Standard
9934 -- could not have been hidden in the generic by a use clause,
9935 -- and therefore remain visible. Other compilation units whose
9936 -- entities appear in Standard must be hidden in an instance.
9938 -- To determine whether an entity is external to the instance
9939 -- we compare the scope depth of its scope with that of the
9940 -- current instance. However, a generic actual of a subprogram
9941 -- instance is declared in the wrapper package but will not be
9942 -- hidden by a use-visible entity. similarly, an entity that is
9943 -- declared in an enclosing instance will not be hidden by an
9944 -- an entity declared in a generic actual, which can only have
9945 -- been use-visible in the generic and will not have hidden the
9946 -- entity in the generic parent.
9948 -- If Id is called Standard, the predefined package with the
9949 -- same name is in the homonym chain. It has to be ignored
9950 -- because it has no defined scope (being the only entity in
9951 -- the system with this mandated behavior).
9953 elsif not Is_Hidden (Id)
9954 and then Present (Scope (Prev))
9955 and then not Is_Wrapper_Package (Scope (Prev))
9956 and then Scope_Depth (Scope (Prev)) <
9957 Scope_Depth (Current_Instance)
9958 and then (Scope (Prev) /= Standard_Standard
9959 or else Sloc (Prev) > Standard_Location)
9961 if In_Open_Scopes (Scope (Prev))
9962 and then Is_Generic_Instance (Scope (Prev))
9963 and then Present (Associated_Formal_Package (P))
9968 Set_Is_Potentially_Use_Visible (Id);
9969 Set_Is_Immediately_Visible (Prev, False);
9970 Append_Elmt (Prev, Hidden_By_Use_Clause (N));
9974 -- A user-defined operator is not use-visible if the predefined
9975 -- operator for the type is immediately visible, which is the case
9976 -- if the type of the operand is in an open scope. This does not
9977 -- apply to user-defined operators that have operands of different
9978 -- types, because the predefined mixed mode operations (multiply
9979 -- and divide) apply to universal types and do not hide anything.
9981 elsif Ekind (Prev) = E_Operator
9982 and then Operator_Matches_Spec (Prev, Id)
9983 and then In_Open_Scopes
9984 (Scope (Base_Type (Etype (First_Formal (Id)))))
9985 and then (No (Next_Formal (First_Formal (Id)))
9986 or else Etype (First_Formal (Id)) =
9987 Etype (Next_Formal (First_Formal (Id)))
9988 or else Chars (Prev) = Name_Op_Expon)
9990 goto Next_Usable_Entity;
9992 -- In an instance, two homonyms may become use_visible through the
9993 -- actuals of distinct formal packages. In the generic, only the
9994 -- current one would have been visible, so make the other one
9997 -- In certain pathological cases it is possible that unrelated
9998 -- homonyms from distinct formal packages may exist in an
9999 -- uninstalled scope. We must test for that here.
10001 elsif Present (Current_Instance)
10002 and then Is_Potentially_Use_Visible (Prev)
10003 and then not Is_Overloadable (Prev)
10004 and then Scope (Id) /= Scope (Prev)
10005 and then Used_As_Generic_Actual (Scope (Prev))
10006 and then Used_As_Generic_Actual (Scope (Id))
10007 and then Is_List_Member (Scope (Prev))
10008 and then not In_Same_List (Current_Use_Clause (Scope (Prev)),
10009 Current_Use_Clause (Scope (Id)))
10011 Set_Is_Potentially_Use_Visible (Prev, False);
10012 Append_Elmt (Prev, Hidden_By_Use_Clause (N));
10015 Prev := Homonym (Prev);
10018 -- On exit, we know entity is not hidden, unless it is private
10020 if not Is_Hidden (Id)
10021 and then ((not Is_Child_Unit (Id)) or else Is_Visible_Lib_Unit (Id))
10023 Set_Is_Potentially_Use_Visible (Id);
10025 if Is_Private_Type (Id) and then Present (Full_View (Id)) then
10026 Set_Is_Potentially_Use_Visible (Full_View (Id));
10030 <<Next_Usable_Entity>>
10034 -- Child units are also made use-visible by a use clause, but they may
10035 -- appear after all visible declarations in the parent entity list.
10037 while Present (Id) loop
10038 if Is_Child_Unit (Id) and then Is_Visible_Lib_Unit (Id) then
10039 Set_Is_Potentially_Use_Visible (Id);
10045 if Chars (Real_P) = Name_System
10046 and then Scope (Real_P) = Standard_Standard
10047 and then Present_System_Aux (N)
10049 Use_One_Package (N);
10051 end Use_One_Package;
10057 procedure Use_One_Type
10059 Installed : Boolean := False;
10060 Force : Boolean := False)
10062 function Spec_Reloaded_For_Body return Boolean;
10063 -- Determine whether the compilation unit is a package body and the use
10064 -- type clause is in the spec of the same package. Even though the spec
10065 -- was analyzed first, its context is reloaded when analysing the body.
10067 procedure Use_Class_Wide_Operations (Typ : Entity_Id);
10068 -- AI05-150: if the use_type_clause carries the "all" qualifier,
10069 -- class-wide operations of ancestor types are use-visible if the
10070 -- ancestor type is visible.
10072 ----------------------------
10073 -- Spec_Reloaded_For_Body --
10074 ----------------------------
10076 function Spec_Reloaded_For_Body return Boolean is
10078 if Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Body then
10080 Spec : constant Node_Id :=
10081 Parent (List_Containing (Parent (Id)));
10084 -- Check whether type is declared in a package specification,
10085 -- and current unit is the corresponding package body. The
10086 -- use clauses themselves may be within a nested package.
10089 Nkind (Spec) = N_Package_Specification
10090 and then In_Same_Source_Unit
10091 (Corresponding_Body (Parent (Spec)),
10092 Cunit_Entity (Current_Sem_Unit));
10097 end Spec_Reloaded_For_Body;
10099 -------------------------------
10100 -- Use_Class_Wide_Operations --
10101 -------------------------------
10103 procedure Use_Class_Wide_Operations (Typ : Entity_Id) is
10104 function Is_Class_Wide_Operation_Of
10106 T : Entity_Id) return Boolean;
10107 -- Determine whether a subprogram has a class-wide parameter or
10108 -- result that is T'Class.
10110 ---------------------------------
10111 -- Is_Class_Wide_Operation_Of --
10112 ---------------------------------
10114 function Is_Class_Wide_Operation_Of
10116 T : Entity_Id) return Boolean
10118 Formal : Entity_Id;
10121 Formal := First_Formal (Op);
10122 while Present (Formal) loop
10123 if Etype (Formal) = Class_Wide_Type (T) then
10127 Next_Formal (Formal);
10130 if Etype (Op) = Class_Wide_Type (T) then
10135 end Is_Class_Wide_Operation_Of;
10142 -- Start of processing for Use_Class_Wide_Operations
10145 Scop := Scope (Typ);
10146 if not Is_Hidden (Scop) then
10147 Ent := First_Entity (Scop);
10148 while Present (Ent) loop
10149 if Is_Overloadable (Ent)
10150 and then Is_Class_Wide_Operation_Of (Ent, Typ)
10151 and then not Is_Potentially_Use_Visible (Ent)
10153 Set_Is_Potentially_Use_Visible (Ent);
10154 Append_Elmt (Ent, Used_Operations (Parent (Id)));
10161 if Is_Derived_Type (Typ) then
10162 Use_Class_Wide_Operations (Etype (Base_Type (Typ)));
10164 end Use_Class_Wide_Operations;
10169 Is_Known_Used : Boolean;
10170 Op_List : Elist_Id;
10173 -- Start of processing for Use_One_Type
10176 if Entity (Id) = Any_Type then
10180 -- It is the type determined by the subtype mark (8.4(8)) whose
10181 -- operations become potentially use-visible.
10183 T := Base_Type (Entity (Id));
10185 -- Either the type itself is used, the package where it is declared is
10186 -- in use or the entity is declared in the current package, thus
10191 and then ((Present (Current_Use_Clause (T))
10192 and then All_Present (Current_Use_Clause (T)))
10193 or else not All_Present (Parent (Id))))
10194 or else In_Use (Scope (T))
10195 or else Scope (T) = Current_Scope;
10197 Set_Redundant_Use (Id,
10198 Is_Known_Used or else Is_Potentially_Use_Visible (T));
10200 if Ekind (T) = E_Incomplete_Type then
10201 Error_Msg_N ("premature usage of incomplete type", Id);
10203 elsif In_Open_Scopes (Scope (T)) then
10206 -- A limited view cannot appear in a use_type_clause. However, an access
10207 -- type whose designated type is limited has the flag but is not itself
10208 -- a limited view unless we only have a limited view of its enclosing
10211 elsif From_Limited_With (T) and then From_Limited_With (Scope (T)) then
10213 ("incomplete type from limited view cannot appear in use clause",
10216 -- If the use clause is redundant, Used_Operations will usually be
10217 -- empty, but we need to set it to empty here in one case: If we are
10218 -- instantiating a generic library unit, then we install the ancestors
10219 -- of that unit in the scope stack, which involves reprocessing use
10220 -- clauses in those ancestors. Such a use clause will typically have a
10221 -- nonempty Used_Operations unless it was redundant in the generic unit,
10222 -- even if it is redundant at the place of the instantiation.
10224 elsif Redundant_Use (Id) then
10226 -- We must avoid incorrectly setting the Current_Use_Clause when we
10227 -- are working with a redundant clause that has already been linked
10228 -- in the Prev_Use_Clause chain, otherwise the chain will break.
10230 if Present (Current_Use_Clause (T))
10231 and then Present (Prev_Use_Clause (Current_Use_Clause (T)))
10232 and then Parent (Id) = Prev_Use_Clause (Current_Use_Clause (T))
10236 Set_Current_Use_Clause (T, Parent (Id));
10239 Set_Used_Operations (Parent (Id), New_Elmt_List);
10241 -- If the subtype mark designates a subtype in a different package,
10242 -- we have to check that the parent type is visible, otherwise the
10243 -- use_type_clause is a no-op. Not clear how to do that???
10246 Set_Current_Use_Clause (T, Parent (Id));
10249 -- If T is tagged, primitive operators on class-wide operands are
10250 -- also deemed available. Note that this is really necessary only
10251 -- in semantics-only mode, because the primitive operators are not
10252 -- fully constructed in this mode, but we do it in all modes for the
10253 -- sake of uniformity, as this should not matter in practice.
10255 if Is_Tagged_Type (T) then
10256 Set_In_Use (Class_Wide_Type (T));
10259 -- Iterate over primitive operations of the type. If an operation is
10260 -- already use_visible, it is the result of a previous use_clause,
10261 -- and already appears on the corresponding entity chain. If the
10262 -- clause is being reinstalled, operations are already use-visible.
10268 Op_List := Collect_Primitive_Operations (T);
10269 Elmt := First_Elmt (Op_List);
10270 while Present (Elmt) loop
10271 if (Nkind (Node (Elmt)) = N_Defining_Operator_Symbol
10272 or else Chars (Node (Elmt)) in Any_Operator_Name)
10273 and then not Is_Hidden (Node (Elmt))
10274 and then not Is_Potentially_Use_Visible (Node (Elmt))
10276 Set_Is_Potentially_Use_Visible (Node (Elmt));
10277 Append_Elmt (Node (Elmt), Used_Operations (Parent (Id)));
10279 elsif Ada_Version >= Ada_2012
10280 and then All_Present (Parent (Id))
10281 and then not Is_Hidden (Node (Elmt))
10282 and then not Is_Potentially_Use_Visible (Node (Elmt))
10284 Set_Is_Potentially_Use_Visible (Node (Elmt));
10285 Append_Elmt (Node (Elmt), Used_Operations (Parent (Id)));
10292 if Ada_Version >= Ada_2012
10293 and then All_Present (Parent (Id))
10294 and then Is_Tagged_Type (T)
10296 Use_Class_Wide_Operations (T);
10300 -- If warning on redundant constructs, check for unnecessary WITH
10303 and then Warn_On_Redundant_Constructs
10304 and then Is_Known_Used
10306 -- with P; with P; use P;
10307 -- package P is package X is package body X is
10308 -- type T ... use P.T;
10310 -- The compilation unit is the body of X. GNAT first compiles the
10311 -- spec of X, then proceeds to the body. At that point P is marked
10312 -- as use visible. The analysis then reinstalls the spec along with
10313 -- its context. The use clause P.T is now recognized as redundant,
10314 -- but in the wrong context. Do not emit a warning in such cases.
10315 -- Do not emit a warning either if we are in an instance, there is
10316 -- no redundancy between an outer use_clause and one that appears
10317 -- within the generic.
10319 and then not Spec_Reloaded_For_Body
10320 and then not In_Instance
10321 and then not In_Inlined_Body
10323 -- The type already has a use clause
10327 -- Case where we know the current use clause for the type
10329 if Present (Current_Use_Clause (T)) then
10330 Use_Clause_Known : declare
10331 Clause1 : constant Node_Id :=
10332 Find_Most_Prev (Current_Use_Clause (T));
10333 Clause2 : constant Node_Id := Parent (Id);
10340 -- Start of processing for Use_Clause_Known
10343 -- If both current use_type_clause and the use_type_clause
10344 -- for the type are at the compilation unit level, one of
10345 -- the units must be an ancestor of the other, and the
10346 -- warning belongs on the descendant.
10348 if Nkind (Parent (Clause1)) = N_Compilation_Unit
10350 Nkind (Parent (Clause2)) = N_Compilation_Unit
10352 -- If the unit is a subprogram body that acts as spec,
10353 -- the context clause is shared with the constructed
10354 -- subprogram spec. Clearly there is no redundancy.
10356 if Clause1 = Clause2 then
10360 Unit1 := Unit (Parent (Clause1));
10361 Unit2 := Unit (Parent (Clause2));
10363 -- If both clauses are on same unit, or one is the body
10364 -- of the other, or one of them is in a subunit, report
10365 -- redundancy on the later one.
10367 if Unit1 = Unit2 or else Nkind (Unit1) = N_Subunit then
10368 Error_Msg_Sloc := Sloc (Current_Use_Clause (T));
10369 Error_Msg_NE -- CODEFIX
10370 ("& is already use-visible through previous "
10371 & "use_type_clause #??", Clause1, T);
10374 elsif Nkind (Unit2) in N_Package_Body | N_Subprogram_Body
10375 and then Nkind (Unit1) /= Nkind (Unit2)
10376 and then Nkind (Unit1) /= N_Subunit
10378 Error_Msg_Sloc := Sloc (Clause1);
10379 Error_Msg_NE -- CODEFIX
10380 ("& is already use-visible through previous "
10381 & "use_type_clause #??", Current_Use_Clause (T), T);
10385 -- There is a redundant use_type_clause in a child unit.
10386 -- Determine which of the units is more deeply nested.
10387 -- If a unit is a package instance, retrieve the entity
10388 -- and its scope from the instance spec.
10390 Ent1 := Entity_Of_Unit (Unit1);
10391 Ent2 := Entity_Of_Unit (Unit2);
10393 if Scope (Ent2) = Standard_Standard then
10394 Error_Msg_Sloc := Sloc (Current_Use_Clause (T));
10397 elsif Scope (Ent1) = Standard_Standard then
10398 Error_Msg_Sloc := Sloc (Id);
10401 -- If both units are child units, we determine which one
10402 -- is the descendant by the scope distance to the
10403 -- ultimate parent unit.
10411 S1 := Scope (Ent1);
10412 S2 := Scope (Ent2);
10414 and then Present (S2)
10415 and then S1 /= Standard_Standard
10416 and then S2 /= Standard_Standard
10422 if S1 = Standard_Standard then
10423 Error_Msg_Sloc := Sloc (Id);
10426 Error_Msg_Sloc := Sloc (Current_Use_Clause (T));
10432 if Parent (Id) /= Err_No then
10433 if Most_Descendant_Use_Clause
10434 (Err_No, Parent (Id)) = Parent (Id)
10436 Error_Msg_Sloc := Sloc (Err_No);
10437 Err_No := Parent (Id);
10440 Error_Msg_NE -- CODEFIX
10441 ("& is already use-visible through previous "
10442 & "use_type_clause #??", Err_No, Id);
10445 -- Case where current use_type_clause and use_type_clause
10446 -- for the type are not both at the compilation unit level.
10447 -- In this case we don't have location information.
10450 Error_Msg_NE -- CODEFIX
10451 ("& is already use-visible through previous "
10452 & "use_type_clause??", Id, T);
10454 end Use_Clause_Known;
10456 -- Here if Current_Use_Clause is not set for T, another case where
10457 -- we do not have the location information available.
10460 Error_Msg_NE -- CODEFIX
10461 ("& is already use-visible through previous "
10462 & "use_type_clause??", Id, T);
10465 -- The package where T is declared is already used
10467 elsif In_Use (Scope (T)) then
10468 -- Due to expansion of contracts we could be attempting to issue
10469 -- a spurious warning - so verify there is a previous use clause.
10471 if Current_Use_Clause (Scope (T)) /=
10472 Find_Most_Prev (Current_Use_Clause (Scope (T)))
10475 Sloc (Find_Most_Prev (Current_Use_Clause (Scope (T))));
10476 Error_Msg_NE -- CODEFIX
10477 ("& is already use-visible through package use clause #??",
10481 -- The current scope is the package where T is declared
10484 Error_Msg_Node_2 := Scope (T);
10485 Error_Msg_NE -- CODEFIX
10486 ("& is already use-visible inside package &??", Id, T);
10495 procedure Write_Info is
10496 Id : Entity_Id := First_Entity (Current_Scope);
10499 -- No point in dumping standard entities
10501 if Current_Scope = Standard_Standard then
10505 Write_Str ("========================================================");
10507 Write_Str (" Defined Entities in ");
10508 Write_Name (Chars (Current_Scope));
10510 Write_Str ("========================================================");
10514 Write_Str ("-- none --");
10518 while Present (Id) loop
10519 Write_Entity_Info (Id, " ");
10524 if Scope (Current_Scope) = Standard_Standard then
10526 -- Print information on the current unit itself
10528 Write_Entity_Info (Current_Scope, " ");
10541 for J in reverse 1 .. Scope_Stack.Last loop
10542 S := Scope_Stack.Table (J).Entity;
10543 Write_Int (Int (S));
10544 Write_Str (" === ");
10545 Write_Name (Chars (S));
10554 procedure we (S : Entity_Id) is
10557 E := First_Entity (S);
10558 while Present (E) loop
10559 Write_Int (Int (E));
10560 Write_Str (" === ");
10561 Write_Name (Chars (E));