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
833 -- Note that we cannot just use the Is_Limited_Record flag because
834 -- it does not apply to records with limited components, for which
835 -- this syntactic flag is not set, but whose size is also fixed.
837 elsif Is_Limited_Type (Typ) then
841 Subt := Make_Temporary (Loc, 'T');
842 Remove_Side_Effects (Nam);
844 Make_Subtype_Declaration (Loc,
845 Defining_Identifier => Subt,
846 Subtype_Indication =>
847 Make_Subtype_From_Expr (Nam, Typ)));
848 Rewrite (Subtype_Mark (N), New_Occurrence_Of (Subt, Loc));
849 Set_Etype (Nam, Subt);
851 -- Suppress discriminant checks on this subtype if the original
852 -- type has defaulted discriminants and Id is a "for of" loop
855 if Has_Defaulted_Discriminants (Typ)
856 and then Nkind (Original_Node (Parent (N))) = N_Loop_Statement
858 Loop_Scheme := Iteration_Scheme (Original_Node (Parent (N)));
860 if Present (Loop_Scheme)
861 and then Present (Iterator_Specification (Loop_Scheme))
864 (Iterator_Specification (Loop_Scheme)) = Id
866 Set_Checks_May_Be_Suppressed (Subt);
867 Push_Local_Suppress_Stack_Entry
869 Check => Discriminant_Check,
874 -- Freeze subtype at once, to prevent order of elaboration
875 -- issues in the backend. The renamed object exists, so its
876 -- type is already frozen in any case.
878 Freeze_Before (N, Subt);
881 end Check_Constrained_Object;
883 ---------------------
884 -- Get_Object_Name --
885 ---------------------
887 function Get_Object_Name (Nod : Node_Id) return Node_Id is
892 while Present (Obj_Nam) loop
893 case Nkind (Obj_Nam) is
894 when N_Attribute_Reference
895 | N_Explicit_Dereference
896 | N_Indexed_Component
899 Obj_Nam := Prefix (Obj_Nam);
901 when N_Selected_Component =>
902 Obj_Nam := Selector_Name (Obj_Nam);
904 when N_Qualified_Expression | N_Type_Conversion =>
905 Obj_Nam := Expression (Obj_Nam);
915 -- Start of processing for Analyze_Object_Renaming
922 Set_Is_Pure (Id, Is_Pure (Current_Scope));
925 -- The renaming of a component that depends on a discriminant requires
926 -- an actual subtype, because in subsequent use of the object Gigi will
927 -- be unable to locate the actual bounds. This explicit step is required
928 -- when the renaming is generated in removing side effects of an
929 -- already-analyzed expression.
931 if Nkind (Nam) = N_Selected_Component and then Analyzed (Nam) then
933 -- The object renaming declaration may become Ghost if it renames a
936 if Is_Entity_Name (Nam) then
937 Mark_Ghost_Renaming (N, Entity (Nam));
941 Dec := Build_Actual_Subtype_Of_Component (Etype (Nam), Nam);
943 if Present (Dec) then
944 Insert_Action (N, Dec);
945 T := Defining_Identifier (Dec);
948 elsif Present (Subtype_Mark (N))
949 or else not Present (Access_Definition (N))
951 if Present (Subtype_Mark (N)) then
952 Find_Type (Subtype_Mark (N));
953 T := Entity (Subtype_Mark (N));
956 -- AI12-0275: Case of object renaming without a subtype_mark
961 -- Normal case of no overloading in object name
963 if not Is_Overloaded (Nam) then
965 -- Catch error cases (such as attempting to rename a procedure
966 -- or package) using the shorthand form.
969 or else Etype (Nam) = Standard_Void_Type
972 ("object name or value expected in renaming", Nam);
974 Set_Ekind (Id, E_Variable);
975 Set_Etype (Id, Any_Type);
983 -- Case of overloaded name, which will be illegal if there's more
984 -- than one acceptable interpretation (such as overloaded function
996 -- More than one candidate interpretation is available
998 -- Remove procedure calls, which syntactically cannot appear
999 -- in this context, but which cannot be removed by type
1000 -- checking, because the context does not impose a type.
1002 Get_First_Interp (Nam, I, It);
1003 while Present (It.Typ) loop
1004 if It.Typ = Standard_Void_Type then
1008 Get_Next_Interp (I, It);
1011 Get_First_Interp (Nam, I, It);
1015 -- If there's no type present, we have an error case (such
1016 -- as overloaded procedures named in the object renaming).
1020 ("object name or value expected in renaming", Nam);
1022 Set_Ekind (Id, E_Variable);
1023 Set_Etype (Id, Any_Type);
1028 Get_Next_Interp (I, It);
1030 if Present (It.Typ) then
1032 It1 := Disambiguate (Nam, I1, I, Any_Type);
1034 if It1 = No_Interp then
1035 Error_Msg_N ("ambiguous name in object renaming", Nam);
1037 Error_Msg_Sloc := Sloc (It.Nam);
1038 Error_Msg_N ("\\possible interpretation#!", Nam);
1040 Error_Msg_Sloc := Sloc (Nam1);
1041 Error_Msg_N ("\\possible interpretation#!", Nam);
1047 Set_Etype (Nam, It1.Typ);
1052 if Etype (Nam) = Standard_Exception_Type then
1054 ("exception requires a subtype mark in renaming", Nam);
1059 -- The object renaming declaration may become Ghost if it renames a
1062 if Is_Entity_Name (Nam) then
1063 Mark_Ghost_Renaming (N, Entity (Nam));
1066 -- Check against AI12-0401 here before Resolve may rewrite Nam and
1067 -- potentially generate spurious warnings.
1069 if Nkind (Nam) = N_Qualified_Expression
1070 and then Is_Variable (Expression (Nam))
1072 (Subtypes_Statically_Match (T, Etype (Expression (Nam)))
1074 Subtypes_Statically_Match (Base_Type (T), Etype (Nam)))
1077 ("subtype of renamed qualified expression does not " &
1078 "statically match", N);
1084 -- If the renamed object is a function call of a limited type,
1085 -- the expansion of the renaming is complicated by the presence
1086 -- of various temporaries and subtypes that capture constraints
1087 -- of the renamed object. Rewrite node as an object declaration,
1088 -- whose expansion is simpler. Given that the object is limited
1089 -- there is no copy involved and no performance hit.
1091 if Nkind (Nam) = N_Function_Call
1092 and then Is_Limited_View (Etype (Nam))
1093 and then not Is_Constrained (Etype (Nam))
1094 and then Comes_From_Source (N)
1097 Set_Ekind (Id, E_Constant);
1099 Make_Object_Declaration (Loc,
1100 Defining_Identifier => Id,
1101 Constant_Present => True,
1102 Object_Definition => New_Occurrence_Of (Etype (Nam), Loc),
1103 Expression => Relocate_Node (Nam)));
1107 -- Ada 2012 (AI05-149): Reject renaming of an anonymous access object
1108 -- when renaming declaration has a named access type. The Ada 2012
1109 -- coverage rules allow an anonymous access type in the context of
1110 -- an expected named general access type, but the renaming rules
1111 -- require the types to be the same. (An exception is when the type
1112 -- of the renaming is also an anonymous access type, which can only
1113 -- happen due to a renaming created by the expander.)
1115 if Nkind (Nam) = N_Type_Conversion
1116 and then not Comes_From_Source (Nam)
1117 and then Is_Anonymous_Access_Type (Etype (Expression (Nam)))
1118 and then not Is_Anonymous_Access_Type (T)
1120 Wrong_Type (Expression (Nam), T); -- Should we give better error???
1123 -- Check that a class-wide object is not being renamed as an object
1124 -- of a specific type. The test for access types is needed to exclude
1125 -- cases where the renamed object is a dynamically tagged access
1126 -- result, such as occurs in certain expansions.
1128 if Is_Tagged_Type (T) then
1129 Check_Dynamically_Tagged_Expression
1135 -- Ada 2005 (AI-230/AI-254): Access renaming
1137 else pragma Assert (Present (Access_Definition (N)));
1141 N => Access_Definition (N));
1145 -- The object renaming declaration may become Ghost if it renames a
1148 if Is_Entity_Name (Nam) then
1149 Mark_Ghost_Renaming (N, Entity (Nam));
1152 -- Ada 2005 AI05-105: if the declaration has an anonymous access
1153 -- type, the renamed object must also have an anonymous type, and
1154 -- this is a name resolution rule. This was implicit in the last part
1155 -- of the first sentence in 8.5.1(3/2), and is made explicit by this
1158 if not Is_Overloaded (Nam) then
1159 if Ekind (Etype (Nam)) /= Ekind (T) then
1161 ("expect anonymous access type in object renaming", N);
1168 Typ : Entity_Id := Empty;
1169 Seen : Boolean := False;
1172 Get_First_Interp (Nam, I, It);
1173 while Present (It.Typ) loop
1175 -- Renaming is ambiguous if more than one candidate
1176 -- interpretation is type-conformant with the context.
1178 if Ekind (It.Typ) = Ekind (T) then
1179 if Ekind (T) = E_Anonymous_Access_Subprogram_Type
1182 (Designated_Type (T), Designated_Type (It.Typ))
1188 ("ambiguous expression in renaming", Nam);
1191 elsif Ekind (T) = E_Anonymous_Access_Type
1193 Covers (Designated_Type (T), Designated_Type (It.Typ))
1199 ("ambiguous expression in renaming", Nam);
1203 if Covers (T, It.Typ) then
1205 Set_Etype (Nam, Typ);
1206 Set_Is_Overloaded (Nam, False);
1210 Get_Next_Interp (I, It);
1217 -- Do not perform the legality checks below when the resolution of
1218 -- the renaming name failed because the associated type is Any_Type.
1220 if Etype (Nam) = Any_Type then
1223 -- Ada 2005 (AI-231): In the case where the type is defined by an
1224 -- access_definition, the renamed entity shall be of an access-to-
1225 -- constant type if and only if the access_definition defines an
1226 -- access-to-constant type. ARM 8.5.1(4)
1228 elsif Constant_Present (Access_Definition (N))
1229 and then not Is_Access_Constant (Etype (Nam))
1232 ("(Ada 2005): the renamed object is not access-to-constant "
1233 & "(RM 8.5.1(6))", N);
1235 elsif not Constant_Present (Access_Definition (N))
1236 and then Is_Access_Constant (Etype (Nam))
1239 ("(Ada 2005): the renamed object is not access-to-variable "
1240 & "(RM 8.5.1(6))", N);
1243 if Is_Access_Subprogram_Type (Etype (Nam)) then
1244 Check_Subtype_Conformant
1245 (Designated_Type (T), Designated_Type (Etype (Nam)));
1247 elsif not Subtypes_Statically_Match
1248 (Designated_Type (T),
1249 Available_View (Designated_Type (Etype (Nam))))
1252 ("subtype of renamed object does not statically match", N);
1256 -- Special processing for renaming function return object. Some errors
1257 -- and warnings are produced only for calls that come from source.
1259 if Nkind (Nam) = N_Function_Call then
1262 -- Usage is illegal in Ada 83, but renamings are also introduced
1263 -- during expansion, and error does not apply to those.
1266 if Comes_From_Source (N) then
1268 ("(Ada 83) cannot rename function return object", Nam);
1271 -- In Ada 95, warn for odd case of renaming parameterless function
1272 -- call if this is not a limited type (where this is useful).
1275 if Warn_On_Object_Renames_Function
1276 and then No (Parameter_Associations (Nam))
1277 and then not Is_Limited_Type (Etype (Nam))
1278 and then Comes_From_Source (Nam)
1281 ("renaming function result object is suspicious?R?", Nam);
1283 ("\function & will be called only once?R?", Nam,
1284 Entity (Name (Nam)));
1285 Error_Msg_N -- CODEFIX
1286 ("\suggest using an initialized constant object "
1287 & "instead?R?", Nam);
1292 Check_Constrained_Object;
1294 -- An object renaming requires an exact match of the type. Class-wide
1295 -- matching is not allowed.
1297 if Is_Class_Wide_Type (T)
1298 and then Base_Type (Etype (Nam)) /= Base_Type (T)
1300 Wrong_Type (Nam, T);
1303 -- We must search for an actual subtype here so that the bounds of
1304 -- objects of unconstrained types don't get dropped on the floor - such
1305 -- as with renamings of formal parameters.
1307 T2 := Get_Actual_Subtype_If_Available (Nam);
1309 -- Ada 2005 (AI-326): Handle wrong use of incomplete type
1311 if Nkind (Nam) = N_Explicit_Dereference
1312 and then Ekind (Etype (T2)) = E_Incomplete_Type
1314 Error_Msg_NE ("invalid use of incomplete type&", Id, T2);
1317 elsif Ekind (Etype (T)) = E_Incomplete_Type then
1318 Error_Msg_NE ("invalid use of incomplete type&", Id, T);
1322 if Ada_Version >= Ada_2005 and then Nkind (Nam) in N_Has_Entity then
1324 Nam_Ent : constant Entity_Id := Entity (Get_Object_Name (Nam));
1325 Nam_Decl : constant Node_Id := Declaration_Node (Nam_Ent);
1328 if Has_Null_Exclusion (N)
1329 and then not Has_Null_Exclusion (Nam_Decl)
1331 -- Ada 2005 (AI-423): If the object name denotes a generic
1332 -- formal object of a generic unit G, and the object renaming
1333 -- declaration occurs within the body of G or within the body
1334 -- of a generic unit declared within the declarative region
1335 -- of G, then the declaration of the formal object of G must
1336 -- have a null exclusion or a null-excluding subtype.
1338 if Is_Formal_Object (Nam_Ent)
1339 and then In_Generic_Scope (Id)
1341 if not Can_Never_Be_Null (Etype (Nam_Ent)) then
1343 ("object does not exclude `NULL` "
1344 & "(RM 8.5.1(4.6/2))", N);
1346 elsif In_Package_Body (Scope (Id)) then
1348 ("formal object does not have a null exclusion"
1349 & "(RM 8.5.1(4.6/2))", N);
1352 -- Ada 2005 (AI-423): Otherwise, the subtype of the object name
1353 -- shall exclude null.
1355 elsif not Can_Never_Be_Null (Etype (Nam_Ent)) then
1357 ("object does not exclude `NULL` "
1358 & "(RM 8.5.1(4.6/2))", N);
1360 -- An instance is illegal if it contains a renaming that
1361 -- excludes null, and the actual does not. The renaming
1362 -- declaration has already indicated that the declaration
1363 -- of the renamed actual in the instance will raise
1364 -- constraint_error.
1366 elsif Nkind (Nam_Decl) = N_Object_Declaration
1367 and then In_Instance
1369 Present (Corresponding_Generic_Association (Nam_Decl))
1370 and then Nkind (Expression (Nam_Decl)) =
1371 N_Raise_Constraint_Error
1374 ("actual does not exclude `NULL` (RM 8.5.1(4.6/2))", N);
1376 -- Finally, if there is a null exclusion, the subtype mark
1377 -- must not be null-excluding.
1379 elsif No (Access_Definition (N))
1380 and then Can_Never_Be_Null (T)
1383 ("`NOT NULL` not allowed (& already excludes null)",
1388 elsif Can_Never_Be_Null (T)
1389 and then not Can_Never_Be_Null (Etype (Nam_Ent))
1392 ("object does not exclude `NULL` (RM 8.5.1(4.6/2))", N);
1394 elsif Has_Null_Exclusion (N)
1395 and then No (Access_Definition (N))
1396 and then Can_Never_Be_Null (T)
1399 ("`NOT NULL` not allowed (& already excludes null)", N, T);
1404 -- Set the Ekind of the entity, unless it has been set already, as is
1405 -- the case for the iteration object over a container with no variable
1406 -- indexing. In that case it's been marked as a constant, and we do not
1407 -- want to change it to a variable.
1409 if Ekind (Id) /= E_Constant then
1410 Set_Ekind (Id, E_Variable);
1413 -- Initialize the object size and alignment. Note that we used to call
1414 -- Init_Size_Align here, but that's wrong for objects which have only
1415 -- an Esize, not an RM_Size field.
1417 Init_Object_Size_Align (Id);
1419 -- If N comes from source then check that the original node is an
1420 -- object reference since there may have been several rewritting and
1421 -- folding. Do not do this for N_Function_Call or N_Explicit_Dereference
1422 -- which might correspond to rewrites of e.g. N_Selected_Component
1423 -- (for example Object.Method rewriting).
1424 -- If N does not come from source then assume the tree is properly
1425 -- formed and accept any object reference. In such cases we do support
1426 -- more cases of renamings anyway, so the actual check on which renaming
1427 -- is valid is better left to the code generator as a last sanity
1430 if Comes_From_Source (N) then
1431 if Nkind (Nam) in N_Function_Call | N_Explicit_Dereference then
1432 Is_Object_Ref := Is_Object_Reference (Nam);
1434 Is_Object_Ref := Is_Object_Reference (Original_Node (Nam));
1437 Is_Object_Ref := True;
1440 if T = Any_Type or else Etype (Nam) = Any_Type then
1443 -- Verify that the renamed entity is an object or function call
1445 elsif Is_Object_Ref then
1446 if Comes_From_Source (N) then
1447 if Is_Dependent_Component_Of_Mutable_Object (Nam) then
1449 ("illegal renaming of discriminant-dependent component", Nam);
1452 -- If the renaming comes from source and the renamed object is a
1453 -- dereference, then mark the prefix as needing debug information,
1454 -- since it might have been rewritten hence internally generated
1455 -- and Debug_Renaming_Declaration will link the renaming to it.
1457 if Nkind (Nam) = N_Explicit_Dereference
1458 and then Is_Entity_Name (Prefix (Nam))
1460 Set_Debug_Info_Needed (Entity (Prefix (Nam)));
1464 -- Weird but legal, equivalent to renaming a function call. Illegal
1465 -- if the literal is the result of constant-folding an attribute
1466 -- reference that is not a function.
1468 elsif Is_Entity_Name (Nam)
1469 and then Ekind (Entity (Nam)) = E_Enumeration_Literal
1470 and then Nkind (Original_Node (Nam)) /= N_Attribute_Reference
1474 -- A named number can only be renamed without a subtype mark
1476 elsif Nkind (Nam) in N_Real_Literal | N_Integer_Literal
1477 and then Present (Subtype_Mark (N))
1478 and then Present (Original_Entity (Nam))
1480 Error_Msg_N ("incompatible types in renaming", Nam);
1482 -- AI12-0383: Names that denote values can be renamed.
1483 -- Ignore (accept) N_Raise_xxx_Error nodes in this context.
1485 elsif Ada_Version < Ada_2020
1486 and then No_Raise_xxx_Error (Nam) = OK
1488 Error_Msg_N ("value in renaming requires -gnat2020", Nam);
1493 if not Is_Variable (Nam) then
1494 Set_Ekind (Id, E_Constant);
1495 Set_Never_Set_In_Source (Id, True);
1496 Set_Is_True_Constant (Id, True);
1499 -- The entity of the renaming declaration needs to reflect whether the
1500 -- renamed object is atomic, independent, volatile or VFA. These flags
1501 -- are set on the renamed object in the RM legality sense.
1503 Set_Is_Atomic (Id, Is_Atomic_Object (Nam));
1504 Set_Is_Independent (Id, Is_Independent_Object (Nam));
1505 Set_Is_Volatile (Id, Is_Volatile_Object (Nam));
1506 Set_Is_Volatile_Full_Access (Id, Is_Volatile_Full_Access_Object (Nam));
1508 -- Treat as volatile if we just set the Volatile flag
1512 -- Or if we are renaming an entity which was marked this way
1514 -- Are there more cases, e.g. X(J) where X is Treat_As_Volatile ???
1516 or else (Is_Entity_Name (Nam)
1517 and then Treat_As_Volatile (Entity (Nam)))
1519 Set_Treat_As_Volatile (Id, True);
1522 -- Now make the link to the renamed object
1524 Set_Renamed_Object (Id, Nam);
1526 -- Implementation-defined aspect specifications can appear in a renaming
1527 -- declaration, but not language-defined ones. The call to procedure
1528 -- Analyze_Aspect_Specifications will take care of this error check.
1530 if Has_Aspects (N) then
1531 Analyze_Aspect_Specifications (N, Id);
1534 -- Deal with dimensions
1536 Analyze_Dimension (N);
1537 end Analyze_Object_Renaming;
1539 ------------------------------
1540 -- Analyze_Package_Renaming --
1541 ------------------------------
1543 procedure Analyze_Package_Renaming (N : Node_Id) is
1544 New_P : constant Entity_Id := Defining_Entity (N);
1549 if Name (N) = Error then
1553 -- Check for Text_IO special unit (we may be renaming a Text_IO child)
1555 Check_Text_IO_Special_Unit (Name (N));
1557 if Current_Scope /= Standard_Standard then
1558 Set_Is_Pure (New_P, Is_Pure (Current_Scope));
1564 if Is_Entity_Name (Name (N)) then
1565 Old_P := Entity (Name (N));
1570 if Etype (Old_P) = Any_Type then
1571 Error_Msg_N ("expect package name in renaming", Name (N));
1573 elsif Ekind (Old_P) /= E_Package
1574 and then not (Ekind (Old_P) = E_Generic_Package
1575 and then In_Open_Scopes (Old_P))
1577 if Ekind (Old_P) = E_Generic_Package then
1579 ("generic package cannot be renamed as a package", Name (N));
1581 Error_Msg_Sloc := Sloc (Old_P);
1583 ("expect package name in renaming, found& declared#",
1587 -- Set basic attributes to minimize cascaded errors
1589 Set_Ekind (New_P, E_Package);
1590 Set_Etype (New_P, Standard_Void_Type);
1592 elsif Present (Renamed_Entity (Old_P))
1593 and then (From_Limited_With (Renamed_Entity (Old_P))
1594 or else Has_Limited_View (Renamed_Entity (Old_P)))
1596 Unit_Is_Visible (Cunit (Get_Source_Unit (Renamed_Entity (Old_P))))
1599 ("renaming of limited view of package & not usable in this context"
1600 & " (RM 8.5.3(3.1/2))", Name (N), Renamed_Entity (Old_P));
1602 -- Set basic attributes to minimize cascaded errors
1604 Set_Ekind (New_P, E_Package);
1605 Set_Etype (New_P, Standard_Void_Type);
1607 -- Here for OK package renaming
1610 -- Entities in the old package are accessible through the renaming
1611 -- entity. The simplest implementation is to have both packages share
1614 Set_Ekind (New_P, E_Package);
1615 Set_Etype (New_P, Standard_Void_Type);
1617 if Present (Renamed_Object (Old_P)) then
1618 Set_Renamed_Object (New_P, Renamed_Object (Old_P));
1620 Set_Renamed_Object (New_P, Old_P);
1623 -- The package renaming declaration may become Ghost if it renames a
1626 Mark_Ghost_Renaming (N, Old_P);
1628 Set_Has_Completion (New_P);
1629 Set_First_Entity (New_P, First_Entity (Old_P));
1630 Set_Last_Entity (New_P, Last_Entity (Old_P));
1631 Set_First_Private_Entity (New_P, First_Private_Entity (Old_P));
1632 Check_Library_Unit_Renaming (N, Old_P);
1633 Generate_Reference (Old_P, Name (N));
1635 -- If the renaming is in the visible part of a package, then we set
1636 -- Renamed_In_Spec for the renamed package, to prevent giving
1637 -- warnings about no entities referenced. Such a warning would be
1638 -- overenthusiastic, since clients can see entities in the renamed
1639 -- package via the visible package renaming.
1642 Ent : constant Entity_Id := Cunit_Entity (Current_Sem_Unit);
1644 if Ekind (Ent) = E_Package
1645 and then not In_Private_Part (Ent)
1646 and then In_Extended_Main_Source_Unit (N)
1647 and then Ekind (Old_P) = E_Package
1649 Set_Renamed_In_Spec (Old_P);
1653 -- If this is the renaming declaration of a package instantiation
1654 -- within itself, it is the declaration that ends the list of actuals
1655 -- for the instantiation. At this point, the subtypes that rename
1656 -- the actuals are flagged as generic, to avoid spurious ambiguities
1657 -- if the actuals for two distinct formals happen to coincide. If
1658 -- the actual is a private type, the subtype has a private completion
1659 -- that is flagged in the same fashion.
1661 -- Resolution is identical to what is was in the original generic.
1662 -- On exit from the generic instance, these are turned into regular
1663 -- subtypes again, so they are compatible with types in their class.
1665 if not Is_Generic_Instance (Old_P) then
1668 Spec := Specification (Unit_Declaration_Node (Old_P));
1671 if Nkind (Spec) = N_Package_Specification
1672 and then Present (Generic_Parent (Spec))
1673 and then Old_P = Current_Scope
1674 and then Chars (New_P) = Chars (Generic_Parent (Spec))
1680 E := First_Entity (Old_P);
1681 while Present (E) and then E /= New_P loop
1683 and then Nkind (Parent (E)) = N_Subtype_Declaration
1685 Set_Is_Generic_Actual_Type (E);
1687 if Is_Private_Type (E)
1688 and then Present (Full_View (E))
1690 Set_Is_Generic_Actual_Type (Full_View (E));
1700 -- Implementation-defined aspect specifications can appear in a renaming
1701 -- declaration, but not language-defined ones. The call to procedure
1702 -- Analyze_Aspect_Specifications will take care of this error check.
1704 if Has_Aspects (N) then
1705 Analyze_Aspect_Specifications (N, New_P);
1707 end Analyze_Package_Renaming;
1709 -------------------------------
1710 -- Analyze_Renamed_Character --
1711 -------------------------------
1713 procedure Analyze_Renamed_Character
1718 C : constant Node_Id := Name (N);
1721 if Ekind (New_S) = E_Function then
1722 Resolve (C, Etype (New_S));
1725 Check_Frozen_Renaming (N, New_S);
1729 Error_Msg_N ("character literal can only be renamed as function", N);
1731 end Analyze_Renamed_Character;
1733 ---------------------------------
1734 -- Analyze_Renamed_Dereference --
1735 ---------------------------------
1737 procedure Analyze_Renamed_Dereference
1742 Nam : constant Node_Id := Name (N);
1743 P : constant Node_Id := Prefix (Nam);
1749 if not Is_Overloaded (P) then
1750 if Ekind (Etype (Nam)) /= E_Subprogram_Type
1751 or else not Type_Conformant (Etype (Nam), New_S)
1753 Error_Msg_N ("designated type does not match specification", P);
1762 Get_First_Interp (Nam, Ind, It);
1764 while Present (It.Nam) loop
1766 if Ekind (It.Nam) = E_Subprogram_Type
1767 and then Type_Conformant (It.Nam, New_S)
1769 if Typ /= Any_Id then
1770 Error_Msg_N ("ambiguous renaming", P);
1777 Get_Next_Interp (Ind, It);
1780 if Typ = Any_Type then
1781 Error_Msg_N ("designated type does not match specification", P);
1786 Check_Frozen_Renaming (N, New_S);
1790 end Analyze_Renamed_Dereference;
1792 ---------------------------
1793 -- Analyze_Renamed_Entry --
1794 ---------------------------
1796 procedure Analyze_Renamed_Entry
1801 Nam : constant Node_Id := Name (N);
1802 Sel : constant Node_Id := Selector_Name (Nam);
1803 Is_Actual : constant Boolean := Present (Corresponding_Formal_Spec (N));
1807 if Entity (Sel) = Any_Id then
1809 -- Selector is undefined on prefix. Error emitted already
1811 Set_Has_Completion (New_S);
1815 -- Otherwise find renamed entity and build body of New_S as a call to it
1817 Old_S := Find_Renamed_Entity (N, Selector_Name (Nam), New_S);
1819 if Old_S = Any_Id then
1820 Error_Msg_N (" no subprogram or entry matches specification", N);
1823 Check_Subtype_Conformant (New_S, Old_S, N);
1824 Generate_Reference (New_S, Defining_Entity (N), 'b');
1825 Style.Check_Identifier (Defining_Entity (N), New_S);
1828 -- Only mode conformance required for a renaming_as_declaration
1830 Check_Mode_Conformant (New_S, Old_S, N);
1833 Inherit_Renamed_Profile (New_S, Old_S);
1835 -- The prefix can be an arbitrary expression that yields a task or
1836 -- protected object, so it must be resolved.
1838 if Is_Access_Type (Etype (Prefix (Nam))) then
1839 Insert_Explicit_Dereference (Prefix (Nam));
1841 Resolve (Prefix (Nam), Scope (Old_S));
1844 Set_Convention (New_S, Convention (Old_S));
1845 Set_Has_Completion (New_S, Inside_A_Generic);
1847 -- AI05-0225: If the renamed entity is a procedure or entry of a
1848 -- protected object, the target object must be a variable.
1850 if Is_Protected_Type (Scope (Old_S))
1851 and then Ekind (New_S) = E_Procedure
1852 and then not Is_Variable (Prefix (Nam))
1856 ("target object of protected operation used as actual for "
1857 & "formal procedure must be a variable", Nam);
1860 ("target object of protected operation renamed as procedure, "
1861 & "must be a variable", Nam);
1866 Check_Frozen_Renaming (N, New_S);
1868 end Analyze_Renamed_Entry;
1870 -----------------------------------
1871 -- Analyze_Renamed_Family_Member --
1872 -----------------------------------
1874 procedure Analyze_Renamed_Family_Member
1879 Nam : constant Node_Id := Name (N);
1880 P : constant Node_Id := Prefix (Nam);
1884 if (Is_Entity_Name (P) and then Ekind (Entity (P)) = E_Entry_Family)
1885 or else (Nkind (P) = N_Selected_Component
1886 and then Ekind (Entity (Selector_Name (P))) = E_Entry_Family)
1888 if Is_Entity_Name (P) then
1889 Old_S := Entity (P);
1891 Old_S := Entity (Selector_Name (P));
1894 if not Entity_Matches_Spec (Old_S, New_S) then
1895 Error_Msg_N ("entry family does not match specification", N);
1898 Check_Subtype_Conformant (New_S, Old_S, N);
1899 Generate_Reference (New_S, Defining_Entity (N), 'b');
1900 Style.Check_Identifier (Defining_Entity (N), New_S);
1904 Error_Msg_N ("no entry family matches specification", N);
1907 Set_Has_Completion (New_S, Inside_A_Generic);
1910 Check_Frozen_Renaming (N, New_S);
1912 end Analyze_Renamed_Family_Member;
1914 -----------------------------------------
1915 -- Analyze_Renamed_Primitive_Operation --
1916 -----------------------------------------
1918 procedure Analyze_Renamed_Primitive_Operation
1928 Ctyp : Conformance_Type) return Boolean;
1929 -- Verify that the signatures of the renamed entity and the new entity
1930 -- match. The first formal of the renamed entity is skipped because it
1931 -- is the target object in any subsequent call.
1939 Ctyp : Conformance_Type) return Boolean
1945 if Ekind (Subp) /= Ekind (New_S) then
1949 Old_F := Next_Formal (First_Formal (Subp));
1950 New_F := First_Formal (New_S);
1951 while Present (Old_F) and then Present (New_F) loop
1952 if not Conforming_Types (Etype (Old_F), Etype (New_F), Ctyp) then
1956 if Ctyp >= Mode_Conformant
1957 and then Ekind (Old_F) /= Ekind (New_F)
1962 Next_Formal (New_F);
1963 Next_Formal (Old_F);
1969 -- Start of processing for Analyze_Renamed_Primitive_Operation
1972 if not Is_Overloaded (Selector_Name (Name (N))) then
1973 Old_S := Entity (Selector_Name (Name (N)));
1975 if not Conforms (Old_S, Type_Conformant) then
1980 -- Find the operation that matches the given signature
1988 Get_First_Interp (Selector_Name (Name (N)), Ind, It);
1990 while Present (It.Nam) loop
1991 if Conforms (It.Nam, Type_Conformant) then
1995 Get_Next_Interp (Ind, It);
2000 if Old_S = Any_Id then
2001 Error_Msg_N ("no subprogram or entry matches specification", N);
2005 if not Conforms (Old_S, Subtype_Conformant) then
2006 Error_Msg_N ("subtype conformance error in renaming", N);
2009 Generate_Reference (New_S, Defining_Entity (N), 'b');
2010 Style.Check_Identifier (Defining_Entity (N), New_S);
2013 -- Only mode conformance required for a renaming_as_declaration
2015 if not Conforms (Old_S, Mode_Conformant) then
2016 Error_Msg_N ("mode conformance error in renaming", N);
2019 -- AI12-0204: The prefix of a prefixed view that is renamed or
2020 -- passed as a formal subprogram must be renamable as an object.
2022 Nam := Prefix (Name (N));
2024 if Is_Object_Reference (Nam) then
2025 if Is_Dependent_Component_Of_Mutable_Object (Nam) then
2027 ("illegal renaming of discriminant-dependent component",
2031 Error_Msg_N ("expect object name in renaming", Nam);
2034 -- Enforce the rule given in (RM 6.3.1 (10.1/2)): a prefixed
2035 -- view of a subprogram is intrinsic, because the compiler has
2036 -- to generate a wrapper for any call to it. If the name in a
2037 -- subprogram renaming is a prefixed view, the entity is thus
2038 -- intrinsic, and 'Access cannot be applied to it.
2040 Set_Convention (New_S, Convention_Intrinsic);
2043 -- Inherit_Renamed_Profile (New_S, Old_S);
2045 -- The prefix can be an arbitrary expression that yields an
2046 -- object, so it must be resolved.
2048 Resolve (Prefix (Name (N)));
2050 end Analyze_Renamed_Primitive_Operation;
2052 ---------------------------------
2053 -- Analyze_Subprogram_Renaming --
2054 ---------------------------------
2056 procedure Analyze_Subprogram_Renaming (N : Node_Id) is
2057 Formal_Spec : constant Entity_Id := Corresponding_Formal_Spec (N);
2058 Is_Actual : constant Boolean := Present (Formal_Spec);
2059 Nam : constant Node_Id := Name (N);
2060 Save_AV : constant Ada_Version_Type := Ada_Version;
2061 Save_AVP : constant Node_Id := Ada_Version_Pragma;
2062 Save_AV_Exp : constant Ada_Version_Type := Ada_Version_Explicit;
2063 Spec : constant Node_Id := Specification (N);
2065 Old_S : Entity_Id := Empty;
2066 Rename_Spec : Entity_Id;
2068 procedure Build_Class_Wide_Wrapper
2069 (Ren_Id : out Entity_Id;
2070 Wrap_Id : out Entity_Id);
2071 -- Ada 2012 (AI05-0071): A generic/instance scenario involving a formal
2072 -- type with unknown discriminants and a generic primitive operation of
2073 -- the said type with a box require special processing when the actual
2074 -- is a class-wide type:
2077 -- type Formal_Typ (<>) is private;
2078 -- with procedure Prim_Op (Param : Formal_Typ) is <>;
2079 -- package Gen is ...
2081 -- package Inst is new Gen (Actual_Typ'Class);
2083 -- In this case the general renaming mechanism used in the prologue of
2084 -- an instance no longer applies:
2086 -- procedure Prim_Op (Param : Formal_Typ) renames Prim_Op;
2088 -- The above is replaced the following wrapper/renaming combination:
2090 -- procedure Wrapper (Param : Formal_Typ) is -- wrapper
2092 -- Prim_Op (Param); -- primitive
2095 -- procedure Prim_Op (Param : Formal_Typ) renames Wrapper;
2097 -- This transformation applies only if there is no explicit visible
2098 -- class-wide operation at the point of the instantiation. Ren_Id is
2099 -- the entity of the renaming declaration. When the transformation
2100 -- applies, Wrap_Id is the entity of the generated class-wide wrapper
2101 -- (or Any_Id). Otherwise, Wrap_Id is the entity of the class-wide
2104 procedure Check_Null_Exclusion
2107 -- Ada 2005 (AI-423): Given renaming Ren of subprogram Sub, check the
2108 -- following AI rules:
2110 -- If Ren denotes a generic formal object of a generic unit G, and the
2111 -- renaming (or instantiation containing the actual) occurs within the
2112 -- body of G or within the body of a generic unit declared within the
2113 -- declarative region of G, then the corresponding parameter of G
2114 -- shall have a null_exclusion; Otherwise the subtype of the Sub's
2115 -- formal parameter shall exclude null.
2117 -- Similarly for its return profile.
2119 procedure Check_SPARK_Primitive_Operation (Subp_Id : Entity_Id);
2120 -- Ensure that a SPARK renaming denoted by its entity Subp_Id does not
2121 -- declare a primitive operation of a tagged type (SPARK RM 6.1.1(3)).
2123 procedure Freeze_Actual_Profile;
2124 -- In Ada 2012, enforce the freezing rule concerning formal incomplete
2125 -- types: a callable entity freezes its profile, unless it has an
2126 -- incomplete untagged formal (RM 13.14(10.2/3)).
2128 function Has_Class_Wide_Actual return Boolean;
2129 -- Ada 2012 (AI05-071, AI05-0131): True if N is the renaming for a
2130 -- defaulted formal subprogram where the actual for the controlling
2131 -- formal type is class-wide.
2133 function Original_Subprogram (Subp : Entity_Id) return Entity_Id;
2134 -- Find renamed entity when the declaration is a renaming_as_body and
2135 -- the renamed entity may itself be a renaming_as_body. Used to enforce
2136 -- rule that a renaming_as_body is illegal if the declaration occurs
2137 -- before the subprogram it completes is frozen, and renaming indirectly
2138 -- renames the subprogram itself.(Defect Report 8652/0027).
2140 ------------------------------
2141 -- Build_Class_Wide_Wrapper --
2142 ------------------------------
2144 procedure Build_Class_Wide_Wrapper
2145 (Ren_Id : out Entity_Id;
2146 Wrap_Id : out Entity_Id)
2148 Loc : constant Source_Ptr := Sloc (N);
2151 (Subp_Id : Entity_Id;
2152 Params : List_Id) return Node_Id;
2153 -- Create a dispatching call to invoke routine Subp_Id with actuals
2154 -- built from the parameter specifications of list Params.
2156 function Build_Expr_Fun_Call
2157 (Subp_Id : Entity_Id;
2158 Params : List_Id) return Node_Id;
2159 -- Create a dispatching call to invoke function Subp_Id with actuals
2160 -- built from the parameter specifications of list Params. Return
2161 -- directly the call, so that it can be used inside an expression
2162 -- function. This is a specificity of the GNATprove mode.
2164 function Build_Spec (Subp_Id : Entity_Id) return Node_Id;
2165 -- Create a subprogram specification based on the subprogram profile
2168 function Find_Primitive (Typ : Entity_Id) return Entity_Id;
2169 -- Find a primitive subprogram of type Typ which matches the profile
2170 -- of the renaming declaration.
2172 procedure Interpretation_Error (Subp_Id : Entity_Id);
2173 -- Emit a continuation error message suggesting subprogram Subp_Id as
2174 -- a possible interpretation.
2176 function Is_Intrinsic_Equality (Subp_Id : Entity_Id) return Boolean;
2177 -- Determine whether subprogram Subp_Id denotes the intrinsic "="
2180 function Is_Suitable_Candidate (Subp_Id : Entity_Id) return Boolean;
2181 -- Determine whether subprogram Subp_Id is a suitable candidate for
2182 -- the role of a wrapped subprogram.
2189 (Subp_Id : Entity_Id;
2190 Params : List_Id) return Node_Id
2192 Actuals : constant List_Id := New_List;
2193 Call_Ref : constant Node_Id := New_Occurrence_Of (Subp_Id, Loc);
2197 -- Build the actual parameters of the call
2199 Formal := First (Params);
2200 while Present (Formal) loop
2202 Make_Identifier (Loc, Chars (Defining_Identifier (Formal))));
2207 -- return Subp_Id (Actuals);
2209 if Ekind (Subp_Id) in E_Function | E_Operator then
2211 Make_Simple_Return_Statement (Loc,
2213 Make_Function_Call (Loc,
2215 Parameter_Associations => Actuals));
2218 -- Subp_Id (Actuals);
2222 Make_Procedure_Call_Statement (Loc,
2224 Parameter_Associations => Actuals);
2228 -------------------------
2229 -- Build_Expr_Fun_Call --
2230 -------------------------
2232 function Build_Expr_Fun_Call
2233 (Subp_Id : Entity_Id;
2234 Params : List_Id) return Node_Id
2236 Actuals : constant List_Id := New_List;
2237 Call_Ref : constant Node_Id := New_Occurrence_Of (Subp_Id, Loc);
2241 pragma Assert (Ekind (Subp_Id) in E_Function | E_Operator);
2243 -- Build the actual parameters of the call
2245 Formal := First (Params);
2246 while Present (Formal) loop
2248 Make_Identifier (Loc, Chars (Defining_Identifier (Formal))));
2253 -- Subp_Id (Actuals);
2256 Make_Function_Call (Loc,
2258 Parameter_Associations => Actuals);
2259 end Build_Expr_Fun_Call;
2265 function Build_Spec (Subp_Id : Entity_Id) return Node_Id is
2266 Params : constant List_Id := Copy_Parameter_List (Subp_Id);
2267 Spec_Id : constant Entity_Id :=
2268 Make_Defining_Identifier (Loc,
2269 Chars => New_External_Name (Chars (Subp_Id), 'R'));
2272 if Ekind (Formal_Spec) = E_Procedure then
2274 Make_Procedure_Specification (Loc,
2275 Defining_Unit_Name => Spec_Id,
2276 Parameter_Specifications => Params);
2279 Make_Function_Specification (Loc,
2280 Defining_Unit_Name => Spec_Id,
2281 Parameter_Specifications => Params,
2282 Result_Definition =>
2283 New_Copy_Tree (Result_Definition (Spec)));
2287 --------------------
2288 -- Find_Primitive --
2289 --------------------
2291 function Find_Primitive (Typ : Entity_Id) return Entity_Id is
2292 procedure Replace_Parameter_Types (Spec : Node_Id);
2293 -- Given a specification Spec, replace all class-wide parameter
2294 -- types with reference to type Typ.
2296 -----------------------------
2297 -- Replace_Parameter_Types --
2298 -----------------------------
2300 procedure Replace_Parameter_Types (Spec : Node_Id) is
2302 Formal_Id : Entity_Id;
2303 Formal_Typ : Node_Id;
2306 Formal := First (Parameter_Specifications (Spec));
2307 while Present (Formal) loop
2308 Formal_Id := Defining_Identifier (Formal);
2309 Formal_Typ := Parameter_Type (Formal);
2311 -- Create a new entity for each class-wide formal to prevent
2312 -- aliasing with the original renaming. Replace the type of
2313 -- such a parameter with the candidate type.
2315 if Nkind (Formal_Typ) = N_Identifier
2316 and then Is_Class_Wide_Type (Etype (Formal_Typ))
2318 Set_Defining_Identifier (Formal,
2319 Make_Defining_Identifier (Loc, Chars (Formal_Id)));
2321 Set_Parameter_Type (Formal, New_Occurrence_Of (Typ, Loc));
2326 end Replace_Parameter_Types;
2330 Alt_Ren : constant Node_Id := New_Copy_Tree (N);
2331 Alt_Nam : constant Node_Id := Name (Alt_Ren);
2332 Alt_Spec : constant Node_Id := Specification (Alt_Ren);
2333 Subp_Id : Entity_Id;
2335 -- Start of processing for Find_Primitive
2338 -- Each attempt to find a suitable primitive of a particular type
2339 -- operates on its own copy of the original renaming. As a result
2340 -- the original renaming is kept decoration and side-effect free.
2342 -- Inherit the overloaded status of the renamed subprogram name
2344 if Is_Overloaded (Nam) then
2345 Set_Is_Overloaded (Alt_Nam);
2346 Save_Interps (Nam, Alt_Nam);
2349 -- The copied renaming is hidden from visibility to prevent the
2350 -- pollution of the enclosing context.
2352 Set_Defining_Unit_Name (Alt_Spec, Make_Temporary (Loc, 'R'));
2354 -- The types of all class-wide parameters must be changed to the
2357 Replace_Parameter_Types (Alt_Spec);
2359 -- Try to find a suitable primitive which matches the altered
2360 -- profile of the renaming specification.
2365 Nam => Name (Alt_Ren),
2366 New_S => Analyze_Subprogram_Specification (Alt_Spec),
2367 Is_Actual => Is_Actual);
2369 -- Do not return Any_Id if the resolion of the altered profile
2370 -- failed as this complicates further checks on the caller side,
2371 -- return Empty instead.
2373 if Subp_Id = Any_Id then
2380 --------------------------
2381 -- Interpretation_Error --
2382 --------------------------
2384 procedure Interpretation_Error (Subp_Id : Entity_Id) is
2386 Error_Msg_Sloc := Sloc (Subp_Id);
2388 if Is_Internal (Subp_Id) then
2390 ("\\possible interpretation: predefined & #",
2394 ("\\possible interpretation: & defined #", Spec, Formal_Spec);
2396 end Interpretation_Error;
2398 ---------------------------
2399 -- Is_Intrinsic_Equality --
2400 ---------------------------
2402 function Is_Intrinsic_Equality (Subp_Id : Entity_Id) return Boolean is
2405 Ekind (Subp_Id) = E_Operator
2406 and then Chars (Subp_Id) = Name_Op_Eq
2407 and then Is_Intrinsic_Subprogram (Subp_Id);
2408 end Is_Intrinsic_Equality;
2410 ---------------------------
2411 -- Is_Suitable_Candidate --
2412 ---------------------------
2414 function Is_Suitable_Candidate (Subp_Id : Entity_Id) return Boolean is
2416 if No (Subp_Id) then
2419 -- An intrinsic subprogram is never a good candidate. This is an
2420 -- indication of a missing primitive, either defined directly or
2421 -- inherited from a parent tagged type.
2423 elsif Is_Intrinsic_Subprogram (Subp_Id) then
2429 end Is_Suitable_Candidate;
2433 Actual_Typ : Entity_Id := Empty;
2434 -- The actual class-wide type for Formal_Typ
2436 CW_Prim_OK : Boolean;
2437 CW_Prim_Op : Entity_Id;
2438 -- The class-wide subprogram (if available) which corresponds to the
2439 -- renamed generic formal subprogram.
2441 Formal_Typ : Entity_Id := Empty;
2442 -- The generic formal type with unknown discriminants
2444 Root_Prim_OK : Boolean;
2445 Root_Prim_Op : Entity_Id;
2446 -- The root type primitive (if available) which corresponds to the
2447 -- renamed generic formal subprogram.
2449 Root_Typ : Entity_Id := Empty;
2450 -- The root type of Actual_Typ
2452 Body_Decl : Node_Id;
2454 Prim_Op : Entity_Id;
2455 Spec_Decl : Node_Id;
2458 -- Start of processing for Build_Class_Wide_Wrapper
2461 -- Analyze the specification of the renaming in case the generation
2462 -- of the class-wide wrapper fails.
2464 Ren_Id := Analyze_Subprogram_Specification (Spec);
2467 -- Do not attempt to build a wrapper if the renaming is in error
2469 if Error_Posted (Nam) then
2473 -- Analyze the renamed name, but do not resolve it. The resolution is
2474 -- completed once a suitable subprogram is found.
2478 -- When the renamed name denotes the intrinsic operator equals, the
2479 -- name must be treated as overloaded. This allows for a potential
2480 -- match against the root type's predefined equality function.
2482 if Is_Intrinsic_Equality (Entity (Nam)) then
2483 Set_Is_Overloaded (Nam);
2484 Collect_Interps (Nam);
2487 -- Step 1: Find the generic formal type with unknown discriminants
2488 -- and its corresponding class-wide actual type from the renamed
2489 -- generic formal subprogram.
2491 Formal := First_Formal (Formal_Spec);
2492 while Present (Formal) loop
2493 if Has_Unknown_Discriminants (Etype (Formal))
2494 and then not Is_Class_Wide_Type (Etype (Formal))
2495 and then Is_Class_Wide_Type (Get_Instance_Of (Etype (Formal)))
2497 Formal_Typ := Etype (Formal);
2498 Actual_Typ := Get_Instance_Of (Formal_Typ);
2499 Root_Typ := Etype (Actual_Typ);
2503 Next_Formal (Formal);
2506 -- The specification of the generic formal subprogram should always
2507 -- contain a formal type with unknown discriminants whose actual is
2508 -- a class-wide type, otherwise this indicates a failure in routine
2509 -- Has_Class_Wide_Actual.
2511 pragma Assert (Present (Formal_Typ));
2513 -- Step 2: Find the proper class-wide subprogram or primitive which
2514 -- corresponds to the renamed generic formal subprogram.
2516 CW_Prim_Op := Find_Primitive (Actual_Typ);
2517 CW_Prim_OK := Is_Suitable_Candidate (CW_Prim_Op);
2518 Root_Prim_Op := Find_Primitive (Root_Typ);
2519 Root_Prim_OK := Is_Suitable_Candidate (Root_Prim_Op);
2521 -- The class-wide actual type has two subprograms which correspond to
2522 -- the renamed generic formal subprogram:
2524 -- with procedure Prim_Op (Param : Formal_Typ);
2526 -- procedure Prim_Op (Param : Actual_Typ); -- may be inherited
2527 -- procedure Prim_Op (Param : Actual_Typ'Class);
2529 -- Even though the declaration of the two subprograms is legal, a
2530 -- call to either one is ambiguous and therefore illegal.
2532 if CW_Prim_OK and Root_Prim_OK then
2534 -- A user-defined primitive has precedence over a predefined one
2536 if Is_Internal (CW_Prim_Op)
2537 and then not Is_Internal (Root_Prim_Op)
2539 Prim_Op := Root_Prim_Op;
2541 elsif Is_Internal (Root_Prim_Op)
2542 and then not Is_Internal (CW_Prim_Op)
2544 Prim_Op := CW_Prim_Op;
2546 elsif CW_Prim_Op = Root_Prim_Op then
2547 Prim_Op := Root_Prim_Op;
2549 -- Otherwise both candidate subprograms are user-defined and
2554 ("ambiguous actual for generic subprogram &",
2556 Interpretation_Error (Root_Prim_Op);
2557 Interpretation_Error (CW_Prim_Op);
2561 elsif CW_Prim_OK and not Root_Prim_OK then
2562 Prim_Op := CW_Prim_Op;
2564 elsif not CW_Prim_OK and Root_Prim_OK then
2565 Prim_Op := Root_Prim_Op;
2567 -- An intrinsic equality may act as a suitable candidate in the case
2568 -- of a null type extension where the parent's equality is hidden. A
2569 -- call to an intrinsic equality is expanded as dispatching.
2571 elsif Present (Root_Prim_Op)
2572 and then Is_Intrinsic_Equality (Root_Prim_Op)
2574 Prim_Op := Root_Prim_Op;
2576 -- Otherwise there are no candidate subprograms. Let the caller
2577 -- diagnose the error.
2583 -- At this point resolution has taken place and the name is no longer
2584 -- overloaded. Mark the primitive as referenced.
2586 Set_Is_Overloaded (Name (N), False);
2587 Set_Referenced (Prim_Op);
2589 -- Do not generate a wrapper when the only candidate is a class-wide
2590 -- subprogram. Instead modify the renaming to directly map the actual
2591 -- to the generic formal.
2593 if CW_Prim_OK and then Prim_Op = CW_Prim_Op then
2595 Rewrite (Nam, New_Occurrence_Of (Prim_Op, Loc));
2599 -- Step 3: Create the declaration and the body of the wrapper, insert
2600 -- all the pieces into the tree.
2602 -- In GNATprove mode, create a function wrapper in the form of an
2603 -- expression function, so that an implicit postcondition relating
2604 -- the result of calling the wrapper function and the result of the
2605 -- dispatching call to the wrapped function is known during proof.
2608 and then Ekind (Ren_Id) in E_Function | E_Operator
2610 New_Spec := Build_Spec (Ren_Id);
2612 Make_Expression_Function (Loc,
2613 Specification => New_Spec,
2616 (Subp_Id => Prim_Op,
2617 Params => Parameter_Specifications (New_Spec)));
2619 Wrap_Id := Defining_Entity (Body_Decl);
2621 -- Otherwise, create separate spec and body for the subprogram
2625 Make_Subprogram_Declaration (Loc,
2626 Specification => Build_Spec (Ren_Id));
2627 Insert_Before_And_Analyze (N, Spec_Decl);
2629 Wrap_Id := Defining_Entity (Spec_Decl);
2632 Make_Subprogram_Body (Loc,
2633 Specification => Build_Spec (Ren_Id),
2634 Declarations => New_List,
2635 Handled_Statement_Sequence =>
2636 Make_Handled_Sequence_Of_Statements (Loc,
2637 Statements => New_List (
2639 (Subp_Id => Prim_Op,
2641 Parameter_Specifications
2642 (Specification (Spec_Decl))))));
2644 Set_Corresponding_Body (Spec_Decl, Defining_Entity (Body_Decl));
2647 -- If the operator carries an Eliminated pragma, indicate that the
2648 -- wrapper is also to be eliminated, to prevent spurious error when
2649 -- using gnatelim on programs that include box-initialization of
2650 -- equality operators.
2652 Set_Is_Eliminated (Wrap_Id, Is_Eliminated (Prim_Op));
2654 -- In GNATprove mode, insert the body in the tree for analysis
2656 if GNATprove_Mode then
2657 Insert_Before_And_Analyze (N, Body_Decl);
2660 -- The generated body does not freeze and must be analyzed when the
2661 -- class-wide wrapper is frozen. The body is only needed if expansion
2664 if Expander_Active then
2665 Append_Freeze_Action (Wrap_Id, Body_Decl);
2668 -- Step 4: The subprogram renaming aliases the wrapper
2670 Rewrite (Nam, New_Occurrence_Of (Wrap_Id, Loc));
2671 end Build_Class_Wide_Wrapper;
2673 --------------------------
2674 -- Check_Null_Exclusion --
2675 --------------------------
2677 procedure Check_Null_Exclusion
2681 Ren_Formal : Entity_Id;
2682 Sub_Formal : Entity_Id;
2684 function Null_Exclusion_Mismatch
2685 (Renaming : Entity_Id; Renamed : Entity_Id) return Boolean;
2686 -- Return True if there is a null exclusion mismatch between
2687 -- Renaming and Renamed, False otherwise.
2689 -----------------------------
2690 -- Null_Exclusion_Mismatch --
2691 -----------------------------
2693 function Null_Exclusion_Mismatch
2694 (Renaming : Entity_Id; Renamed : Entity_Id) return Boolean is
2696 return Has_Null_Exclusion (Parent (Renaming))
2698 not (Has_Null_Exclusion (Parent (Renamed))
2699 or else (Can_Never_Be_Null (Etype (Renamed))
2701 (Is_Formal_Subprogram (Sub)
2702 and then In_Generic_Body (Current_Scope))));
2703 end Null_Exclusion_Mismatch;
2708 Ren_Formal := First_Formal (Ren);
2709 Sub_Formal := First_Formal (Sub);
2710 while Present (Ren_Formal) and then Present (Sub_Formal) loop
2711 if Null_Exclusion_Mismatch (Ren_Formal, Sub_Formal) then
2712 Error_Msg_Sloc := Sloc (Sub_Formal);
2714 ("`NOT NULL` required for parameter &#",
2715 Ren_Formal, Sub_Formal);
2718 Next_Formal (Ren_Formal);
2719 Next_Formal (Sub_Formal);
2722 -- Return profile check
2724 if Nkind (Parent (Ren)) = N_Function_Specification
2725 and then Nkind (Parent (Sub)) = N_Function_Specification
2726 and then Null_Exclusion_Mismatch (Ren, Sub)
2728 Error_Msg_Sloc := Sloc (Sub);
2729 Error_Msg_N ("return must specify `NOT NULL`#", Ren);
2731 end Check_Null_Exclusion;
2733 -------------------------------------
2734 -- Check_SPARK_Primitive_Operation --
2735 -------------------------------------
2737 procedure Check_SPARK_Primitive_Operation (Subp_Id : Entity_Id) is
2738 Prag : constant Node_Id := SPARK_Pragma (Subp_Id);
2742 -- Nothing to do when the subprogram is not subject to SPARK_Mode On
2743 -- because this check applies to SPARK code only.
2745 if not (Present (Prag)
2746 and then Get_SPARK_Mode_From_Annotation (Prag) = On)
2750 -- Nothing to do when the subprogram is not a primitive operation
2752 elsif not Is_Primitive (Subp_Id) then
2756 Typ := Find_Dispatching_Type (Subp_Id);
2758 -- Nothing to do when the subprogram is a primitive operation of an
2765 -- At this point a renaming declaration introduces a new primitive
2766 -- operation for a tagged type.
2768 Error_Msg_Node_2 := Typ;
2770 ("subprogram renaming & cannot declare primitive for type & "
2771 & "(SPARK RM 6.1.1(3))", N, Subp_Id);
2772 end Check_SPARK_Primitive_Operation;
2774 ---------------------------
2775 -- Freeze_Actual_Profile --
2776 ---------------------------
2778 procedure Freeze_Actual_Profile is
2780 Has_Untagged_Inc : Boolean;
2781 Instantiation_Node : constant Node_Id := Parent (N);
2784 if Ada_Version >= Ada_2012 then
2785 F := First_Formal (Formal_Spec);
2786 Has_Untagged_Inc := False;
2787 while Present (F) loop
2788 if Ekind (Etype (F)) = E_Incomplete_Type
2789 and then not Is_Tagged_Type (Etype (F))
2791 Has_Untagged_Inc := True;
2798 if Ekind (Formal_Spec) = E_Function
2799 and then not Is_Tagged_Type (Etype (Formal_Spec))
2801 Has_Untagged_Inc := True;
2804 if not Has_Untagged_Inc then
2805 F := First_Formal (Old_S);
2806 while Present (F) loop
2807 Freeze_Before (Instantiation_Node, Etype (F));
2809 if Is_Incomplete_Or_Private_Type (Etype (F))
2810 and then No (Underlying_Type (Etype (F)))
2812 -- Exclude generic types, or types derived from them.
2813 -- They will be frozen in the enclosing instance.
2815 if Is_Generic_Type (Etype (F))
2816 or else Is_Generic_Type (Root_Type (Etype (F)))
2820 -- A limited view of a type declared elsewhere needs no
2821 -- freezing actions.
2823 elsif From_Limited_With (Etype (F)) then
2828 ("type& must be frozen before this point",
2829 Instantiation_Node, Etype (F));
2837 end Freeze_Actual_Profile;
2839 ---------------------------
2840 -- Has_Class_Wide_Actual --
2841 ---------------------------
2843 function Has_Class_Wide_Actual return Boolean is
2845 Formal_Typ : Entity_Id;
2849 Formal := First_Formal (Formal_Spec);
2850 while Present (Formal) loop
2851 Formal_Typ := Etype (Formal);
2853 if Has_Unknown_Discriminants (Formal_Typ)
2854 and then not Is_Class_Wide_Type (Formal_Typ)
2855 and then Is_Class_Wide_Type (Get_Instance_Of (Formal_Typ))
2860 Next_Formal (Formal);
2865 end Has_Class_Wide_Actual;
2867 -------------------------
2868 -- Original_Subprogram --
2869 -------------------------
2871 function Original_Subprogram (Subp : Entity_Id) return Entity_Id is
2872 Orig_Decl : Node_Id;
2873 Orig_Subp : Entity_Id;
2876 -- First case: renamed entity is itself a renaming
2878 if Present (Alias (Subp)) then
2879 return Alias (Subp);
2881 elsif Nkind (Unit_Declaration_Node (Subp)) = N_Subprogram_Declaration
2882 and then Present (Corresponding_Body (Unit_Declaration_Node (Subp)))
2884 -- Check if renamed entity is a renaming_as_body
2887 Unit_Declaration_Node
2888 (Corresponding_Body (Unit_Declaration_Node (Subp)));
2890 if Nkind (Orig_Decl) = N_Subprogram_Renaming_Declaration then
2891 Orig_Subp := Entity (Name (Orig_Decl));
2893 if Orig_Subp = Rename_Spec then
2895 -- Circularity detected
2900 return (Original_Subprogram (Orig_Subp));
2908 end Original_Subprogram;
2912 CW_Actual : constant Boolean := Has_Class_Wide_Actual;
2913 -- Ada 2012 (AI05-071, AI05-0131): True if the renaming is for a
2914 -- defaulted formal subprogram when the actual for a related formal
2915 -- type is class-wide.
2917 Inst_Node : Node_Id := Empty;
2920 -- Start of processing for Analyze_Subprogram_Renaming
2923 -- We must test for the attribute renaming case before the Analyze
2924 -- call because otherwise Sem_Attr will complain that the attribute
2925 -- is missing an argument when it is analyzed.
2927 if Nkind (Nam) = N_Attribute_Reference then
2929 -- In the case of an abstract formal subprogram association, rewrite
2930 -- an actual given by a stream or Put_Image attribute as the name of
2931 -- the corresponding stream or Put_Image primitive of the type.
2933 -- In a generic context the stream and Put_Image operations are not
2934 -- generated, and this must be treated as a normal attribute
2935 -- reference, to be expanded in subsequent instantiations.
2938 and then Is_Abstract_Subprogram (Formal_Spec)
2939 and then Expander_Active
2942 Prefix_Type : constant Entity_Id := Entity (Prefix (Nam));
2946 -- The class-wide forms of the stream and Put_Image attributes
2947 -- are not primitive dispatching operations (even though they
2948 -- internally dispatch).
2950 if Is_Class_Wide_Type (Prefix_Type) then
2952 ("attribute must be a primitive dispatching operation",
2957 -- Retrieve the primitive subprogram associated with the
2958 -- attribute. This can only be a stream attribute, since those
2959 -- are the only ones that are dispatching (and the actual for
2960 -- an abstract formal subprogram must be dispatching
2963 case Attribute_Name (Nam) is
2966 Find_Optional_Prim_Op (Prefix_Type, TSS_Stream_Input);
2970 Find_Optional_Prim_Op (Prefix_Type, TSS_Stream_Output);
2974 Find_Optional_Prim_Op (Prefix_Type, TSS_Stream_Read);
2978 Find_Optional_Prim_Op (Prefix_Type, TSS_Stream_Write);
2980 when Name_Put_Image =>
2982 Find_Optional_Prim_Op (Prefix_Type, TSS_Put_Image);
2986 ("attribute must be a primitive dispatching operation",
2991 -- If no stream operation was found, and the type is limited,
2992 -- the user should have defined one. This rule does not apply
2996 and then Attribute_Name (Nam) /= Name_Put_Image
2998 if Is_Limited_Type (Prefix_Type) then
3000 ("stream operation not defined for type&",
3004 -- Otherwise, compiler should have generated default
3007 raise Program_Error;
3011 -- Rewrite the attribute into the name of its corresponding
3012 -- primitive dispatching subprogram. We can then proceed with
3013 -- the usual processing for subprogram renamings.
3016 Prim_Name : constant Node_Id :=
3017 Make_Identifier (Sloc (Nam),
3018 Chars => Chars (Prim));
3020 Set_Entity (Prim_Name, Prim);
3021 Rewrite (Nam, Prim_Name);
3026 -- Normal processing for a renaming of an attribute
3029 Attribute_Renaming (N);
3034 -- Check whether this declaration corresponds to the instantiation of a
3035 -- formal subprogram.
3037 -- If this is an instantiation, the corresponding actual is frozen and
3038 -- error messages can be made more precise. If this is a default
3039 -- subprogram, the entity is already established in the generic, and is
3040 -- not retrieved by visibility. If it is a default with a box, the
3041 -- candidate interpretations, if any, have been collected when building
3042 -- the renaming declaration. If overloaded, the proper interpretation is
3043 -- determined in Find_Renamed_Entity. If the entity is an operator,
3044 -- Find_Renamed_Entity applies additional visibility checks.
3047 Inst_Node := Unit_Declaration_Node (Formal_Spec);
3049 -- Check whether the renaming is for a defaulted actual subprogram
3050 -- with a class-wide actual.
3052 if CW_Actual and then Box_Present (Inst_Node) then
3053 Build_Class_Wide_Wrapper (New_S, Old_S);
3055 elsif Is_Entity_Name (Nam)
3056 and then Present (Entity (Nam))
3057 and then not Comes_From_Source (Nam)
3058 and then not Is_Overloaded (Nam)
3060 Old_S := Entity (Nam);
3062 -- The subprogram renaming declaration may become Ghost if it
3063 -- renames a Ghost entity.
3065 Mark_Ghost_Renaming (N, Old_S);
3067 New_S := Analyze_Subprogram_Specification (Spec);
3071 if Ekind (Old_S) = E_Operator then
3075 if Box_Present (Inst_Node) then
3076 Old_S := Find_Renamed_Entity (N, Name (N), New_S, Is_Actual);
3078 -- If there is an immediately visible homonym of the operator
3079 -- and the declaration has a default, this is worth a warning
3080 -- because the user probably did not intend to get the pre-
3081 -- defined operator, visible in the generic declaration. To
3082 -- find if there is an intended candidate, analyze the renaming
3083 -- again in the current context.
3085 elsif Scope (Old_S) = Standard_Standard
3086 and then Present (Default_Name (Inst_Node))
3089 Decl : constant Node_Id := New_Copy_Tree (N);
3093 Set_Entity (Name (Decl), Empty);
3094 Analyze (Name (Decl));
3096 Find_Renamed_Entity (Decl, Name (Decl), New_S, True);
3099 and then In_Open_Scopes (Scope (Hidden))
3100 and then Is_Immediately_Visible (Hidden)
3101 and then Comes_From_Source (Hidden)
3102 and then Hidden /= Old_S
3104 Error_Msg_Sloc := Sloc (Hidden);
3106 ("default subprogram is resolved in the generic "
3107 & "declaration (RM 12.6(17))??", N);
3108 Error_Msg_NE ("\and will not use & #??", N, Hidden);
3117 -- The subprogram renaming declaration may become Ghost if it
3118 -- renames a Ghost entity.
3120 if Is_Entity_Name (Nam) then
3121 Mark_Ghost_Renaming (N, Entity (Nam));
3124 New_S := Analyze_Subprogram_Specification (Spec);
3128 -- Renamed entity must be analyzed first, to avoid being hidden by
3129 -- new name (which might be the same in a generic instance).
3133 -- The subprogram renaming declaration may become Ghost if it renames
3136 if Is_Entity_Name (Nam) then
3137 Mark_Ghost_Renaming (N, Entity (Nam));
3140 -- The renaming defines a new overloaded entity, which is analyzed
3141 -- like a subprogram declaration.
3143 New_S := Analyze_Subprogram_Specification (Spec);
3146 if Current_Scope /= Standard_Standard then
3147 Set_Is_Pure (New_S, Is_Pure (Current_Scope));
3150 -- Set SPARK mode from current context
3152 Set_SPARK_Pragma (New_S, SPARK_Mode_Pragma);
3153 Set_SPARK_Pragma_Inherited (New_S);
3155 Rename_Spec := Find_Corresponding_Spec (N);
3157 -- Case of Renaming_As_Body
3159 if Present (Rename_Spec) then
3160 Check_Previous_Null_Procedure (N, Rename_Spec);
3162 -- Renaming declaration is the completion of the declaration of
3163 -- Rename_Spec. We build an actual body for it at the freezing point.
3165 Set_Corresponding_Spec (N, Rename_Spec);
3167 -- Deal with special case of stream functions of abstract types
3170 if Nkind (Unit_Declaration_Node (Rename_Spec)) =
3171 N_Abstract_Subprogram_Declaration
3173 -- Input stream functions are abstract if the object type is
3174 -- abstract. Similarly, all default stream functions for an
3175 -- interface type are abstract. However, these subprograms may
3176 -- receive explicit declarations in representation clauses, making
3177 -- the attribute subprograms usable as defaults in subsequent
3179 -- In this case we rewrite the declaration to make the subprogram
3180 -- non-abstract. We remove the previous declaration, and insert
3181 -- the new one at the point of the renaming, to prevent premature
3182 -- access to unfrozen types. The new declaration reuses the
3183 -- specification of the previous one, and must not be analyzed.
3186 (Is_Primitive (Entity (Nam))
3188 Is_Abstract_Type (Find_Dispatching_Type (Entity (Nam))));
3190 Old_Decl : constant Node_Id :=
3191 Unit_Declaration_Node (Rename_Spec);
3192 New_Decl : constant Node_Id :=
3193 Make_Subprogram_Declaration (Sloc (N),
3195 Relocate_Node (Specification (Old_Decl)));
3198 Insert_After (N, New_Decl);
3199 Set_Is_Abstract_Subprogram (Rename_Spec, False);
3200 Set_Analyzed (New_Decl);
3204 Set_Corresponding_Body (Unit_Declaration_Node (Rename_Spec), New_S);
3206 if Ada_Version = Ada_83 and then Comes_From_Source (N) then
3207 Error_Msg_N ("(Ada 83) renaming cannot serve as a body", N);
3210 Set_Convention (New_S, Convention (Rename_Spec));
3211 Check_Fully_Conformant (New_S, Rename_Spec);
3212 Set_Public_Status (New_S);
3214 if No_Return (Rename_Spec)
3215 and then not No_Return (Entity (Nam))
3218 ("renamed subprogram & must be No_Return", N, Entity (Nam));
3220 ("\since renaming subprogram is No_Return (RM 6.5.1(7/2))", N);
3223 -- The specification does not introduce new formals, but only
3224 -- repeats the formals of the original subprogram declaration.
3225 -- For cross-reference purposes, and for refactoring tools, we
3226 -- treat the formals of the renaming declaration as body formals.
3228 Reference_Body_Formals (Rename_Spec, New_S);
3230 -- Indicate that the entity in the declaration functions like the
3231 -- corresponding body, and is not a new entity. The body will be
3232 -- constructed later at the freeze point, so indicate that the
3233 -- completion has not been seen yet.
3235 Set_Ekind (New_S, E_Subprogram_Body);
3236 New_S := Rename_Spec;
3237 Set_Has_Completion (Rename_Spec, False);
3239 -- Ada 2005: check overriding indicator
3241 if Present (Overridden_Operation (Rename_Spec)) then
3242 if Must_Not_Override (Specification (N)) then
3244 ("subprogram& overrides inherited operation",
3248 and then not Must_Override (Specification (N))
3250 Style.Missing_Overriding (N, Rename_Spec);
3253 elsif Must_Override (Specification (N)) then
3254 Error_Msg_NE ("subprogram& is not overriding", N, Rename_Spec);
3257 -- AI12-0132: a renames-as-body freezes the expression of any
3258 -- expression function that it renames.
3260 if Is_Entity_Name (Nam)
3261 and then Is_Expression_Function (Entity (Nam))
3262 and then not Inside_A_Generic
3265 (Def_Id => Entity (Nam),
3266 Typ => Etype (Entity (Nam)),
3269 (Original_Node (Unit_Declaration_Node (Entity (Nam)))),
3273 -- Normal subprogram renaming (not renaming as body)
3276 Generate_Definition (New_S);
3277 New_Overloaded_Entity (New_S);
3279 if not (Is_Entity_Name (Nam)
3280 and then Is_Intrinsic_Subprogram (Entity (Nam)))
3282 Check_Delayed_Subprogram (New_S);
3285 -- Verify that a SPARK renaming does not declare a primitive
3286 -- operation of a tagged type.
3288 Check_SPARK_Primitive_Operation (New_S);
3291 -- There is no need for elaboration checks on the new entity, which may
3292 -- be called before the next freezing point where the body will appear.
3293 -- Elaboration checks refer to the real entity, not the one created by
3294 -- the renaming declaration.
3296 Set_Kill_Elaboration_Checks (New_S, True);
3298 -- If we had a previous error, indicate a completion is present to stop
3299 -- junk cascaded messages, but don't take any further action.
3301 if Etype (Nam) = Any_Type then
3302 Set_Has_Completion (New_S);
3305 -- Case where name has the form of a selected component
3307 elsif Nkind (Nam) = N_Selected_Component then
3309 -- A name which has the form A.B can designate an entry of task A, a
3310 -- protected operation of protected object A, or finally a primitive
3311 -- operation of object A. In the later case, A is an object of some
3312 -- tagged type, or an access type that denotes one such. To further
3313 -- distinguish these cases, note that the scope of a task entry or
3314 -- protected operation is type of the prefix.
3316 -- The prefix could be an overloaded function call that returns both
3317 -- kinds of operations. This overloading pathology is left to the
3318 -- dedicated reader ???
3321 T : constant Entity_Id := Etype (Prefix (Nam));
3329 and then Is_Tagged_Type (Designated_Type (T))))
3330 and then Scope (Entity (Selector_Name (Nam))) /= T
3332 Analyze_Renamed_Primitive_Operation
3333 (N, New_S, Present (Rename_Spec));
3337 -- Renamed entity is an entry or protected operation. For those
3338 -- cases an explicit body is built (at the point of freezing of
3339 -- this entity) that contains a call to the renamed entity.
3341 -- This is not allowed for renaming as body if the renamed
3342 -- spec is already frozen (see RM 8.5.4(5) for details).
3344 if Present (Rename_Spec) and then Is_Frozen (Rename_Spec) then
3346 ("renaming-as-body cannot rename entry as subprogram", N);
3348 ("\since & is already frozen (RM 8.5.4(5))",
3351 Analyze_Renamed_Entry (N, New_S, Present (Rename_Spec));
3358 -- Case where name is an explicit dereference X.all
3360 elsif Nkind (Nam) = N_Explicit_Dereference then
3362 -- Renamed entity is designated by access_to_subprogram expression.
3363 -- Must build body to encapsulate call, as in the entry case.
3365 Analyze_Renamed_Dereference (N, New_S, Present (Rename_Spec));
3368 -- Indexed component
3370 elsif Nkind (Nam) = N_Indexed_Component then
3371 Analyze_Renamed_Family_Member (N, New_S, Present (Rename_Spec));
3374 -- Character literal
3376 elsif Nkind (Nam) = N_Character_Literal then
3377 Analyze_Renamed_Character (N, New_S, Present (Rename_Spec));
3380 -- Only remaining case is where we have a non-entity name, or a renaming
3381 -- of some other non-overloadable entity.
3383 elsif not Is_Entity_Name (Nam)
3384 or else not Is_Overloadable (Entity (Nam))
3386 -- Do not mention the renaming if it comes from an instance
3388 if not Is_Actual then
3389 Error_Msg_N ("expect valid subprogram name in renaming", N);
3391 Error_Msg_NE ("no visible subprogram for formal&", N, Nam);
3397 -- Find the renamed entity that matches the given specification. Disable
3398 -- Ada_83 because there is no requirement of full conformance between
3399 -- renamed entity and new entity, even though the same circuit is used.
3401 -- This is a bit of an odd case, which introduces a really irregular use
3402 -- of Ada_Version[_Explicit]. Would be nice to find cleaner way to do
3405 Ada_Version := Ada_Version_Type'Max (Ada_Version, Ada_95);
3406 Ada_Version_Pragma := Empty;
3407 Ada_Version_Explicit := Ada_Version;
3410 Old_S := Find_Renamed_Entity (N, Name (N), New_S, Is_Actual);
3412 -- The visible operation may be an inherited abstract operation that
3413 -- was overridden in the private part, in which case a call will
3414 -- dispatch to the overriding operation. Use the overriding one in
3415 -- the renaming declaration, to prevent spurious errors below.
3417 if Is_Overloadable (Old_S)
3418 and then Is_Abstract_Subprogram (Old_S)
3419 and then No (DTC_Entity (Old_S))
3420 and then Present (Alias (Old_S))
3421 and then not Is_Abstract_Subprogram (Alias (Old_S))
3422 and then Present (Overridden_Operation (Alias (Old_S)))
3424 Old_S := Alias (Old_S);
3427 -- When the renamed subprogram is overloaded and used as an actual
3428 -- of a generic, its entity is set to the first available homonym.
3429 -- We must first disambiguate the name, then set the proper entity.
3431 if Is_Actual and then Is_Overloaded (Nam) then
3432 Set_Entity (Nam, Old_S);
3436 -- Most common case: subprogram renames subprogram. No body is generated
3437 -- in this case, so we must indicate the declaration is complete as is.
3438 -- and inherit various attributes of the renamed subprogram.
3440 if No (Rename_Spec) then
3441 Set_Has_Completion (New_S);
3442 Set_Is_Imported (New_S, Is_Imported (Entity (Nam)));
3443 Set_Is_Pure (New_S, Is_Pure (Entity (Nam)));
3444 Set_Is_Preelaborated (New_S, Is_Preelaborated (Entity (Nam)));
3446 -- Ada 2005 (AI-423): Check the consistency of null exclusions
3447 -- between a subprogram and its correct renaming.
3449 -- Note: the Any_Id check is a guard that prevents compiler crashes
3450 -- when performing a null exclusion check between a renaming and a
3451 -- renamed subprogram that has been found to be illegal.
3453 if Ada_Version >= Ada_2005 and then Entity (Nam) /= Any_Id then
3454 Check_Null_Exclusion
3456 Sub => Entity (Nam));
3459 -- Enforce the Ada 2005 rule that the renamed entity cannot require
3460 -- overriding. The flag Requires_Overriding is set very selectively
3461 -- and misses some other illegal cases. The additional conditions
3462 -- checked below are sufficient but not necessary ???
3464 -- The rule does not apply to the renaming generated for an actual
3465 -- subprogram in an instance.
3470 -- Guard against previous errors, and omit renamings of predefined
3473 elsif Ekind (Old_S) not in E_Function | E_Procedure then
3476 elsif Requires_Overriding (Old_S)
3478 (Is_Abstract_Subprogram (Old_S)
3479 and then Present (Find_Dispatching_Type (Old_S))
3480 and then not Is_Abstract_Type (Find_Dispatching_Type (Old_S)))
3483 ("renamed entity cannot be subprogram that requires overriding "
3484 & "(RM 8.5.4 (5.1))", N);
3488 Prev : constant Entity_Id := Overridden_Operation (New_S);
3492 (Has_Non_Trivial_Precondition (Prev)
3493 or else Has_Non_Trivial_Precondition (Old_S))
3496 ("conflicting inherited classwide preconditions in renaming "
3497 & "of& (RM 6.1.1 (17)", N, Old_S);
3502 if Old_S /= Any_Id then
3503 if Is_Actual and then From_Default (N) then
3505 -- This is an implicit reference to the default actual
3507 Generate_Reference (Old_S, Nam, Typ => 'i', Force => True);
3510 Generate_Reference (Old_S, Nam);
3513 Check_Internal_Protected_Use (N, Old_S);
3515 -- For a renaming-as-body, require subtype conformance, but if the
3516 -- declaration being completed has not been frozen, then inherit the
3517 -- convention of the renamed subprogram prior to checking conformance
3518 -- (unless the renaming has an explicit convention established; the
3519 -- rule stated in the RM doesn't seem to address this ???).
3521 if Present (Rename_Spec) then
3522 Generate_Reference (Rename_Spec, Defining_Entity (Spec), 'b');
3523 Style.Check_Identifier (Defining_Entity (Spec), Rename_Spec);
3525 if not Is_Frozen (Rename_Spec) then
3526 if not Has_Convention_Pragma (Rename_Spec) then
3527 Set_Convention (New_S, Convention (Old_S));
3530 if Ekind (Old_S) /= E_Operator then
3531 Check_Mode_Conformant (New_S, Old_S, Spec);
3534 if Original_Subprogram (Old_S) = Rename_Spec then
3535 Error_Msg_N ("unfrozen subprogram cannot rename itself ", N);
3537 Check_Formal_Subprogram_Conformance (New_S, Old_S, Spec);
3540 Check_Subtype_Conformant (New_S, Old_S, Spec);
3543 Check_Frozen_Renaming (N, Rename_Spec);
3545 -- Check explicitly that renamed entity is not intrinsic, because
3546 -- in a generic the renamed body is not built. In this case,
3547 -- the renaming_as_body is a completion.
3549 if Inside_A_Generic then
3550 if Is_Frozen (Rename_Spec)
3551 and then Is_Intrinsic_Subprogram (Old_S)
3554 ("subprogram in renaming_as_body cannot be intrinsic",
3558 Set_Has_Completion (Rename_Spec);
3561 elsif Ekind (Old_S) /= E_Operator then
3563 -- If this a defaulted subprogram for a class-wide actual there is
3564 -- no check for mode conformance, given that the signatures don't
3565 -- match (the source mentions T but the actual mentions T'Class).
3570 -- No need for a redundant error message if this is a nested
3571 -- instance, unless the current instantiation (of a child unit)
3572 -- is a compilation unit, which is not analyzed when the parent
3573 -- generic is analyzed.
3576 or else No (Enclosing_Instance)
3577 or else Is_Compilation_Unit (Current_Scope)
3579 Check_Mode_Conformant (New_S, Old_S);
3583 if No (Rename_Spec) then
3585 -- The parameter profile of the new entity is that of the renamed
3586 -- entity: the subtypes given in the specification are irrelevant.
3588 Inherit_Renamed_Profile (New_S, Old_S);
3590 -- A call to the subprogram is transformed into a call to the
3591 -- renamed entity. This is transitive if the renamed entity is
3592 -- itself a renaming.
3594 if Present (Alias (Old_S)) then
3595 Set_Alias (New_S, Alias (Old_S));
3597 Set_Alias (New_S, Old_S);
3600 -- Note that we do not set Is_Intrinsic_Subprogram if we have a
3601 -- renaming as body, since the entity in this case is not an
3602 -- intrinsic (it calls an intrinsic, but we have a real body for
3603 -- this call, and it is in this body that the required intrinsic
3604 -- processing will take place).
3606 -- Also, if this is a renaming of inequality, the renamed operator
3607 -- is intrinsic, but what matters is the corresponding equality
3608 -- operator, which may be user-defined.
3610 Set_Is_Intrinsic_Subprogram
3612 Is_Intrinsic_Subprogram (Old_S)
3614 (Chars (Old_S) /= Name_Op_Ne
3615 or else Ekind (Old_S) = E_Operator
3616 or else Is_Intrinsic_Subprogram
3617 (Corresponding_Equality (Old_S))));
3619 if Ekind (Alias (New_S)) = E_Operator then
3620 Set_Has_Delayed_Freeze (New_S, False);
3623 -- If the renaming corresponds to an association for an abstract
3624 -- formal subprogram, then various attributes must be set to
3625 -- indicate that the renaming is an abstract dispatching operation
3626 -- with a controlling type.
3628 if Is_Actual and then Is_Abstract_Subprogram (Formal_Spec) then
3630 -- Mark the renaming as abstract here, so Find_Dispatching_Type
3631 -- see it as corresponding to a generic association for a
3632 -- formal abstract subprogram
3634 Set_Is_Abstract_Subprogram (New_S);
3637 New_S_Ctrl_Type : constant Entity_Id :=
3638 Find_Dispatching_Type (New_S);
3639 Old_S_Ctrl_Type : constant Entity_Id :=
3640 Find_Dispatching_Type (Old_S);
3644 -- The actual must match the (instance of the) formal,
3645 -- and must be a controlling type.
3647 if Old_S_Ctrl_Type /= New_S_Ctrl_Type
3648 or else No (New_S_Ctrl_Type)
3650 if No (New_S_Ctrl_Type) then
3652 ("actual must be dispatching subprogram", Nam);
3655 ("actual must be dispatching subprogram for type&",
3656 Nam, New_S_Ctrl_Type);
3660 Set_Is_Dispatching_Operation (New_S);
3661 Check_Controlling_Formals (New_S_Ctrl_Type, New_S);
3663 -- If the actual in the formal subprogram is itself a
3664 -- formal abstract subprogram association, there's no
3665 -- dispatch table component or position to inherit.
3667 if Present (DTC_Entity (Old_S)) then
3668 Set_DTC_Entity (New_S, DTC_Entity (Old_S));
3669 Set_DT_Position_Value (New_S, DT_Position (Old_S));
3679 -- The following is illegal, because F hides whatever other F may
3681 -- function F (...) renames F;
3684 or else (Nkind (Nam) /= N_Expanded_Name
3685 and then Chars (Old_S) = Chars (New_S))
3687 Error_Msg_N ("subprogram cannot rename itself", N);
3689 -- This is illegal even if we use a selector:
3690 -- function F (...) renames Pkg.F;
3691 -- because F is still hidden.
3693 elsif Nkind (Nam) = N_Expanded_Name
3694 and then Entity (Prefix (Nam)) = Current_Scope
3695 and then Chars (Selector_Name (Nam)) = Chars (New_S)
3697 -- This is an error, but we overlook the error and accept the
3698 -- renaming if the special Overriding_Renamings mode is in effect.
3700 if not Overriding_Renamings then
3702 ("implicit operation& is not visible (RM 8.3 (15))",
3707 Set_Convention (New_S, Convention (Old_S));
3709 if Is_Abstract_Subprogram (Old_S) then
3710 if Present (Rename_Spec) then
3712 ("a renaming-as-body cannot rename an abstract subprogram",
3714 Set_Has_Completion (Rename_Spec);
3716 Set_Is_Abstract_Subprogram (New_S);
3720 Check_Library_Unit_Renaming (N, Old_S);
3722 -- Pathological case: procedure renames entry in the scope of its
3723 -- task. Entry is given by simple name, but body must be built for
3724 -- procedure. Of course if called it will deadlock.
3726 if Ekind (Old_S) = E_Entry then
3727 Set_Has_Completion (New_S, False);
3728 Set_Alias (New_S, Empty);
3731 -- Do not freeze the renaming nor the renamed entity when the context
3732 -- is an enclosing generic. Freezing is an expansion activity, and in
3733 -- addition the renamed entity may depend on the generic formals of
3734 -- the enclosing generic.
3736 if Is_Actual and not Inside_A_Generic then
3737 Freeze_Before (N, Old_S);
3738 Freeze_Actual_Profile;
3739 Set_Has_Delayed_Freeze (New_S, False);
3740 Freeze_Before (N, New_S);
3742 -- An abstract subprogram is only allowed as an actual in the case
3743 -- where the formal subprogram is also abstract.
3745 if (Ekind (Old_S) = E_Procedure or else Ekind (Old_S) = E_Function)
3746 and then Is_Abstract_Subprogram (Old_S)
3747 and then not Is_Abstract_Subprogram (Formal_Spec)
3750 ("abstract subprogram not allowed as generic actual", Nam);
3755 -- A common error is to assume that implicit operators for types are
3756 -- defined in Standard, or in the scope of a subtype. In those cases
3757 -- where the renamed entity is given with an expanded name, it is
3758 -- worth mentioning that operators for the type are not declared in
3759 -- the scope given by the prefix.
3761 if Nkind (Nam) = N_Expanded_Name
3762 and then Nkind (Selector_Name (Nam)) = N_Operator_Symbol
3763 and then Scope (Entity (Nam)) = Standard_Standard
3766 T : constant Entity_Id :=
3767 Base_Type (Etype (First_Formal (New_S)));
3769 Error_Msg_Node_2 := Prefix (Nam);
3771 ("operator for type& is not declared in&", Prefix (Nam), T);
3776 ("no visible subprogram matches the specification for&",
3780 if Present (Candidate_Renaming) then
3787 F1 := First_Formal (Candidate_Renaming);
3788 F2 := First_Formal (New_S);
3789 T1 := First_Subtype (Etype (F1));
3790 while Present (F1) and then Present (F2) loop
3795 if Present (F1) and then Present (Default_Value (F1)) then
3796 if Present (Next_Formal (F1)) then
3798 ("\missing specification for & and other formals with "
3799 & "defaults", Spec, F1);
3801 Error_Msg_NE ("\missing specification for &", Spec, F1);
3805 if Nkind (Nam) = N_Operator_Symbol
3806 and then From_Default (N)
3808 Error_Msg_Node_2 := T1;
3810 ("default & on & is not directly visible", Nam, Nam);
3816 -- Ada 2005 AI 404: if the new subprogram is dispatching, verify that
3817 -- controlling access parameters are known non-null for the renamed
3818 -- subprogram. Test also applies to a subprogram instantiation that
3819 -- is dispatching. Test is skipped if some previous error was detected
3820 -- that set Old_S to Any_Id.
3822 if Ada_Version >= Ada_2005
3823 and then Old_S /= Any_Id
3824 and then not Is_Dispatching_Operation (Old_S)
3825 and then Is_Dispatching_Operation (New_S)
3832 Old_F := First_Formal (Old_S);
3833 New_F := First_Formal (New_S);
3834 while Present (Old_F) loop
3835 if Ekind (Etype (Old_F)) = E_Anonymous_Access_Type
3836 and then Is_Controlling_Formal (New_F)
3837 and then not Can_Never_Be_Null (Old_F)
3839 Error_Msg_N ("access parameter is controlling,", New_F);
3841 ("\corresponding parameter of& must be explicitly null "
3842 & "excluding", New_F, Old_S);
3845 Next_Formal (Old_F);
3846 Next_Formal (New_F);
3851 -- A useful warning, suggested by Ada Bug Finder (Ada-Europe 2005)
3852 -- is to warn if an operator is being renamed as a different operator.
3853 -- If the operator is predefined, examine the kind of the entity, not
3854 -- the abbreviated declaration in Standard.
3856 if Comes_From_Source (N)
3857 and then Present (Old_S)
3858 and then (Nkind (Old_S) = N_Defining_Operator_Symbol
3859 or else Ekind (Old_S) = E_Operator)
3860 and then Nkind (New_S) = N_Defining_Operator_Symbol
3861 and then Chars (Old_S) /= Chars (New_S)
3864 ("& is being renamed as a different operator??", N, Old_S);
3867 -- Check for renaming of obsolescent subprogram
3869 Check_Obsolescent_2005_Entity (Entity (Nam), Nam);
3871 -- Another warning or some utility: if the new subprogram as the same
3872 -- name as the old one, the old one is not hidden by an outer homograph,
3873 -- the new one is not a public symbol, and the old one is otherwise
3874 -- directly visible, the renaming is superfluous.
3876 if Chars (Old_S) = Chars (New_S)
3877 and then Comes_From_Source (N)
3878 and then Scope (Old_S) /= Standard_Standard
3879 and then Warn_On_Redundant_Constructs
3880 and then (Is_Immediately_Visible (Old_S)
3881 or else Is_Potentially_Use_Visible (Old_S))
3882 and then Is_Overloadable (Current_Scope)
3883 and then Chars (Current_Scope) /= Chars (Old_S)
3886 ("redundant renaming, entity is directly visible?r?", Name (N));
3889 -- Implementation-defined aspect specifications can appear in a renaming
3890 -- declaration, but not language-defined ones. The call to procedure
3891 -- Analyze_Aspect_Specifications will take care of this error check.
3893 if Has_Aspects (N) then
3894 Analyze_Aspect_Specifications (N, New_S);
3900 and then Has_Yield_Aspect (Formal_Spec)
3901 and then not Has_Yield_Aspect (Old_S)
3903 Error_Msg_Name_1 := Name_Yield;
3905 ("actual subprogram& must have aspect% to match formal", Name (N));
3908 Ada_Version := Save_AV;
3909 Ada_Version_Pragma := Save_AVP;
3910 Ada_Version_Explicit := Save_AV_Exp;
3912 -- Check if we are looking at an Ada 2012 defaulted formal subprogram
3913 -- and mark any use_package_clauses that affect the visibility of the
3914 -- implicit generic actual.
3916 -- Also, we may be looking at an internal renaming of a user-defined
3917 -- subprogram created for a generic formal subprogram association,
3918 -- which will also have to be marked here. This can occur when the
3919 -- corresponding formal subprogram contains references to other generic
3922 if Is_Generic_Actual_Subprogram (New_S)
3923 and then (Is_Intrinsic_Subprogram (New_S)
3924 or else From_Default (N)
3925 or else Nkind (N) = N_Subprogram_Renaming_Declaration)
3927 Mark_Use_Clauses (New_S);
3929 -- Handle overloaded subprograms
3931 if Present (Alias (New_S)) then
3932 Mark_Use_Clauses (Alias (New_S));
3935 end Analyze_Subprogram_Renaming;
3937 -------------------------
3938 -- Analyze_Use_Package --
3939 -------------------------
3941 -- Resolve the package names in the use clause, and make all the visible
3942 -- entities defined in the package potentially use-visible. If the package
3943 -- is already in use from a previous use clause, its visible entities are
3944 -- already use-visible. In that case, mark the occurrence as a redundant
3945 -- use. If the package is an open scope, i.e. if the use clause occurs
3946 -- within the package itself, ignore it.
3948 procedure Analyze_Use_Package (N : Node_Id; Chain : Boolean := True) is
3949 procedure Analyze_Package_Name (Clause : Node_Id);
3950 -- Perform analysis on a package name from a use_package_clause
3952 procedure Analyze_Package_Name_List (Head_Clause : Node_Id);
3953 -- Similar to Analyze_Package_Name but iterates over all the names
3956 --------------------------
3957 -- Analyze_Package_Name --
3958 --------------------------
3960 procedure Analyze_Package_Name (Clause : Node_Id) is
3961 Pack : constant Node_Id := Name (Clause);
3965 pragma Assert (Nkind (Clause) = N_Use_Package_Clause);
3968 -- Verify that the package standard is not directly named in a
3969 -- use_package_clause.
3971 if Nkind (Parent (Clause)) = N_Compilation_Unit
3972 and then Nkind (Pack) = N_Expanded_Name
3974 Pref := Prefix (Pack);
3976 while Nkind (Pref) = N_Expanded_Name loop
3977 Pref := Prefix (Pref);
3980 if Entity (Pref) = Standard_Standard then
3982 ("predefined package Standard cannot appear in a context "
3986 end Analyze_Package_Name;
3988 -------------------------------
3989 -- Analyze_Package_Name_List --
3990 -------------------------------
3992 procedure Analyze_Package_Name_List (Head_Clause : Node_Id) is
3996 -- Due to the way source use clauses are split during parsing we are
3997 -- forced to simply iterate through all entities in scope until the
3998 -- clause representing the last name in the list is found.
4000 Curr := Head_Clause;
4001 while Present (Curr) loop
4002 Analyze_Package_Name (Curr);
4004 -- Stop iterating over the names in the use clause when we are at
4007 exit when not More_Ids (Curr) and then Prev_Ids (Curr);
4010 end Analyze_Package_Name_List;
4016 -- Start of processing for Analyze_Use_Package
4019 Set_Hidden_By_Use_Clause (N, No_Elist);
4021 -- Use clause not allowed in a spec of a predefined package declaration
4022 -- except that packages whose file name starts a-n are OK (these are
4023 -- children of Ada.Numerics, which are never loaded by Rtsfind).
4025 if Is_Predefined_Unit (Current_Sem_Unit)
4026 and then Get_Name_String
4027 (Unit_File_Name (Current_Sem_Unit)) (1 .. 3) /= "a-n"
4028 and then Nkind (Unit (Cunit (Current_Sem_Unit))) =
4029 N_Package_Declaration
4031 Error_Msg_N ("use clause not allowed in predefined spec", N);
4034 -- Loop through all package names from the original use clause in
4035 -- order to analyze referenced packages. A use_package_clause with only
4036 -- one name does not have More_Ids or Prev_Ids set, while a clause with
4037 -- More_Ids only starts the chain produced by the parser.
4039 if not More_Ids (N) and then not Prev_Ids (N) then
4040 Analyze_Package_Name (N);
4042 elsif More_Ids (N) and then not Prev_Ids (N) then
4043 Analyze_Package_Name_List (N);
4046 if not Is_Entity_Name (Name (N)) then
4047 Error_Msg_N ("& is not a package", Name (N));
4053 Chain_Use_Clause (N);
4056 Pack := Entity (Name (N));
4058 -- There are many cases where scopes are manipulated during analysis, so
4059 -- check that Pack's current use clause has not already been chained
4060 -- before setting its previous use clause.
4062 if Ekind (Pack) = E_Package
4063 and then Present (Current_Use_Clause (Pack))
4064 and then Current_Use_Clause (Pack) /= N
4065 and then No (Prev_Use_Clause (N))
4066 and then Prev_Use_Clause (Current_Use_Clause (Pack)) /= N
4068 Set_Prev_Use_Clause (N, Current_Use_Clause (Pack));
4071 -- Mark all entities as potentially use visible
4073 if Ekind (Pack) /= E_Package and then Etype (Pack) /= Any_Type then
4074 if Ekind (Pack) = E_Generic_Package then
4075 Error_Msg_N -- CODEFIX
4076 ("a generic package is not allowed in a use clause", Name (N));
4078 elsif Is_Generic_Subprogram (Pack) then
4079 Error_Msg_N -- CODEFIX
4080 ("a generic subprogram is not allowed in a use clause",
4083 elsif Is_Subprogram (Pack) then
4084 Error_Msg_N -- CODEFIX
4085 ("a subprogram is not allowed in a use clause", Name (N));
4088 Error_Msg_N ("& is not allowed in a use clause", Name (N));
4092 if Nkind (Parent (N)) = N_Compilation_Unit then
4093 Check_In_Previous_With_Clause (N, Name (N));
4096 Use_One_Package (N, Name (N));
4099 Mark_Ghost_Clause (N);
4100 end Analyze_Use_Package;
4102 ----------------------
4103 -- Analyze_Use_Type --
4104 ----------------------
4106 procedure Analyze_Use_Type (N : Node_Id; Chain : Boolean := True) is
4111 Set_Hidden_By_Use_Clause (N, No_Elist);
4113 -- Chain clause to list of use clauses in current scope when flagged
4116 Chain_Use_Clause (N);
4119 -- Obtain the base type of the type denoted within the use_type_clause's
4122 Id := Subtype_Mark (N);
4124 E := Base_Type (Entity (Id));
4126 -- There are many cases where a use_type_clause may be reanalyzed due to
4127 -- manipulation of the scope stack so we much guard against those cases
4128 -- here, otherwise, we must add the new use_type_clause to the previous
4129 -- use_type_clause chain in order to mark redundant use_type_clauses as
4130 -- used. When the redundant use-type clauses appear in a parent unit and
4131 -- a child unit we must prevent a circularity in the chain that would
4132 -- otherwise result from the separate steps of analysis and installation
4133 -- of the parent context.
4135 if Present (Current_Use_Clause (E))
4136 and then Current_Use_Clause (E) /= N
4137 and then Prev_Use_Clause (Current_Use_Clause (E)) /= N
4138 and then No (Prev_Use_Clause (N))
4140 Set_Prev_Use_Clause (N, Current_Use_Clause (E));
4143 -- If the Used_Operations list is already initialized, the clause has
4144 -- been analyzed previously, and it is being reinstalled, for example
4145 -- when the clause appears in a package spec and we are compiling the
4146 -- corresponding package body. In that case, make the entities on the
4147 -- existing list use_visible, and mark the corresponding types In_Use.
4149 if Present (Used_Operations (N)) then
4154 Use_One_Type (Subtype_Mark (N), Installed => True);
4156 Elmt := First_Elmt (Used_Operations (N));
4157 while Present (Elmt) loop
4158 Set_Is_Potentially_Use_Visible (Node (Elmt));
4166 -- Otherwise, create new list and attach to it the operations that are
4167 -- made use-visible by the clause.
4169 Set_Used_Operations (N, New_Elmt_List);
4172 if E /= Any_Type then
4175 if Nkind (Parent (N)) = N_Compilation_Unit then
4176 if Nkind (Id) = N_Identifier then
4177 Error_Msg_N ("type is not directly visible", Id);
4179 elsif Is_Child_Unit (Scope (E))
4180 and then Scope (E) /= System_Aux_Id
4182 Check_In_Previous_With_Clause (N, Prefix (Id));
4187 -- If the use_type_clause appears in a compilation unit context,
4188 -- check whether it comes from a unit that may appear in a
4189 -- limited_with_clause, for a better error message.
4191 if Nkind (Parent (N)) = N_Compilation_Unit
4192 and then Nkind (Id) /= N_Identifier
4198 function Mentioned (Nam : Node_Id) return Boolean;
4199 -- Check whether the prefix of expanded name for the type
4200 -- appears in the prefix of some limited_with_clause.
4206 function Mentioned (Nam : Node_Id) return Boolean is
4208 return Nkind (Name (Item)) = N_Selected_Component
4209 and then Chars (Prefix (Name (Item))) = Chars (Nam);
4213 Pref := Prefix (Id);
4214 Item := First (Context_Items (Parent (N)));
4215 while Present (Item) and then Item /= N loop
4216 if Nkind (Item) = N_With_Clause
4217 and then Limited_Present (Item)
4218 and then Mentioned (Pref)
4221 (Get_Msg_Id, "premature usage of incomplete type");
4230 Mark_Ghost_Clause (N);
4231 end Analyze_Use_Type;
4233 ------------------------
4234 -- Attribute_Renaming --
4235 ------------------------
4237 procedure Attribute_Renaming (N : Node_Id) is
4238 Loc : constant Source_Ptr := Sloc (N);
4239 Nam : constant Node_Id := Name (N);
4240 Spec : constant Node_Id := Specification (N);
4241 New_S : constant Entity_Id := Defining_Unit_Name (Spec);
4242 Aname : constant Name_Id := Attribute_Name (Nam);
4244 Form_Num : Nat := 0;
4245 Expr_List : List_Id := No_List;
4247 Attr_Node : Node_Id;
4248 Body_Node : Node_Id;
4249 Param_Spec : Node_Id;
4252 Generate_Definition (New_S);
4254 -- This procedure is called in the context of subprogram renaming, and
4255 -- thus the attribute must be one that is a subprogram. All of those
4256 -- have at least one formal parameter, with the exceptions of the GNAT
4257 -- attribute 'Img, which GNAT treats as renameable.
4259 if not Is_Non_Empty_List (Parameter_Specifications (Spec)) then
4260 if Aname /= Name_Img then
4262 ("subprogram renaming an attribute must have formals", N);
4267 Param_Spec := First (Parameter_Specifications (Spec));
4268 while Present (Param_Spec) loop
4269 Form_Num := Form_Num + 1;
4271 if Nkind (Parameter_Type (Param_Spec)) /= N_Access_Definition then
4272 Find_Type (Parameter_Type (Param_Spec));
4274 -- The profile of the new entity denotes the base type (s) of
4275 -- the types given in the specification. For access parameters
4276 -- there are no subtypes involved.
4278 Rewrite (Parameter_Type (Param_Spec),
4280 (Base_Type (Entity (Parameter_Type (Param_Spec))), Loc));
4283 if No (Expr_List) then
4284 Expr_List := New_List;
4287 Append_To (Expr_List,
4288 Make_Identifier (Loc,
4289 Chars => Chars (Defining_Identifier (Param_Spec))));
4291 -- The expressions in the attribute reference are not freeze
4292 -- points. Neither is the attribute as a whole, see below.
4294 Set_Must_Not_Freeze (Last (Expr_List));
4299 -- Immediate error if too many formals. Other mismatches in number or
4300 -- types of parameters are detected when we analyze the body of the
4301 -- subprogram that we construct.
4303 if Form_Num > 2 then
4304 Error_Msg_N ("too many formals for attribute", N);
4306 -- Error if the attribute reference has expressions that look like
4307 -- formal parameters.
4309 elsif Present (Expressions (Nam)) then
4310 Error_Msg_N ("illegal expressions in attribute reference", Nam);
4312 elsif Aname in Name_Compose | Name_Exponent | Name_Leading_Part |
4313 Name_Pos | Name_Round | Name_Scaling |
4316 if Nkind (N) = N_Subprogram_Renaming_Declaration
4317 and then Present (Corresponding_Formal_Spec (N))
4320 ("generic actual cannot be attribute involving universal type",
4324 ("attribute involving a universal type cannot be renamed",
4329 -- Rewrite attribute node to have a list of expressions corresponding to
4330 -- the subprogram formals. A renaming declaration is not a freeze point,
4331 -- and the analysis of the attribute reference should not freeze the
4332 -- type of the prefix. We use the original node in the renaming so that
4333 -- its source location is preserved, and checks on stream attributes are
4334 -- properly applied.
4336 Attr_Node := Relocate_Node (Nam);
4337 Set_Expressions (Attr_Node, Expr_List);
4339 Set_Must_Not_Freeze (Attr_Node);
4340 Set_Must_Not_Freeze (Prefix (Nam));
4342 -- Case of renaming a function
4344 if Nkind (Spec) = N_Function_Specification then
4345 if Is_Procedure_Attribute_Name (Aname) then
4346 Error_Msg_N ("attribute can only be renamed as procedure", Nam);
4350 Find_Type (Result_Definition (Spec));
4351 Rewrite (Result_Definition (Spec),
4353 (Base_Type (Entity (Result_Definition (Spec))), Loc));
4356 Make_Subprogram_Body (Loc,
4357 Specification => Spec,
4358 Declarations => New_List,
4359 Handled_Statement_Sequence =>
4360 Make_Handled_Sequence_Of_Statements (Loc,
4361 Statements => New_List (
4362 Make_Simple_Return_Statement (Loc,
4363 Expression => Attr_Node))));
4365 -- Case of renaming a procedure
4368 if not Is_Procedure_Attribute_Name (Aname) then
4369 Error_Msg_N ("attribute can only be renamed as function", Nam);
4374 Make_Subprogram_Body (Loc,
4375 Specification => Spec,
4376 Declarations => New_List,
4377 Handled_Statement_Sequence =>
4378 Make_Handled_Sequence_Of_Statements (Loc,
4379 Statements => New_List (Attr_Node)));
4382 -- Signal the ABE mechanism that the generated subprogram body has not
4383 -- ABE ramifications.
4385 Set_Was_Attribute_Reference (Body_Node);
4387 -- In case of tagged types we add the body of the generated function to
4388 -- the freezing actions of the type (because in the general case such
4389 -- type is still not frozen). We exclude from this processing generic
4390 -- formal subprograms found in instantiations.
4392 -- We must exclude restricted run-time libraries because
4393 -- entity AST_Handler is defined in package System.Aux_Dec which is not
4394 -- available in those platforms. Note that we cannot use the function
4395 -- Restricted_Profile (instead of Configurable_Run_Time_Mode) because
4396 -- the ZFP run-time library is not defined as a profile, and we do not
4397 -- want to deal with AST_Handler in ZFP mode.
4399 if not Configurable_Run_Time_Mode
4400 and then not Present (Corresponding_Formal_Spec (N))
4401 and then Etype (Nam) /= RTE (RE_AST_Handler)
4404 P : constant Node_Id := Prefix (Nam);
4407 -- The prefix of 'Img is an object that is evaluated for each call
4408 -- of the function that renames it.
4410 if Aname = Name_Img then
4411 Preanalyze_And_Resolve (P);
4413 -- For all other attribute renamings, the prefix is a subtype
4419 -- If the target type is not yet frozen, add the body to the
4420 -- actions to be elaborated at freeze time.
4422 if Is_Tagged_Type (Etype (P))
4423 and then In_Open_Scopes (Scope (Etype (P)))
4425 Ensure_Freeze_Node (Etype (P));
4426 Append_Freeze_Action (Etype (P), Body_Node);
4428 Rewrite (N, Body_Node);
4430 Set_Etype (New_S, Base_Type (Etype (New_S)));
4434 -- Generic formal subprograms or AST_Handler renaming
4437 Rewrite (N, Body_Node);
4439 Set_Etype (New_S, Base_Type (Etype (New_S)));
4442 if Is_Compilation_Unit (New_S) then
4444 ("a library unit can only rename another library unit", N);
4447 -- We suppress elaboration warnings for the resulting entity, since
4448 -- clearly they are not needed, and more particularly, in the case
4449 -- of a generic formal subprogram, the resulting entity can appear
4450 -- after the instantiation itself, and thus look like a bogus case
4451 -- of access before elaboration.
4453 if Legacy_Elaboration_Checks then
4454 Set_Suppress_Elaboration_Warnings (New_S);
4456 end Attribute_Renaming;
4458 ----------------------
4459 -- Chain_Use_Clause --
4460 ----------------------
4462 procedure Chain_Use_Clause (N : Node_Id) is
4463 Level : Int := Scope_Stack.Last;
4469 if not Is_Compilation_Unit (Current_Scope)
4470 or else not Is_Child_Unit (Current_Scope)
4474 -- Common case for compilation unit
4476 elsif Defining_Entity (Parent (N)) = Current_Scope then
4480 -- If declaration appears in some other scope, it must be in some
4481 -- parent unit when compiling a child.
4483 Pack := Defining_Entity (Parent (N));
4485 if not In_Open_Scopes (Pack) then
4488 -- If the use clause appears in an ancestor and we are in the
4489 -- private part of the immediate parent, the use clauses are
4490 -- already installed.
4492 elsif Pack /= Scope (Current_Scope)
4493 and then In_Private_Part (Scope (Current_Scope))
4498 -- Find entry for parent unit in scope stack
4500 while Scope_Stack.Table (Level).Entity /= Pack loop
4506 Set_Next_Use_Clause (N,
4507 Scope_Stack.Table (Level).First_Use_Clause);
4508 Scope_Stack.Table (Level).First_Use_Clause := N;
4509 end Chain_Use_Clause;
4511 ---------------------------
4512 -- Check_Frozen_Renaming --
4513 ---------------------------
4515 procedure Check_Frozen_Renaming (N : Node_Id; Subp : Entity_Id) is
4520 if Is_Frozen (Subp) and then not Has_Completion (Subp) then
4523 (Parent (Declaration_Node (Subp)), Defining_Entity (N));
4525 if Is_Entity_Name (Name (N)) then
4526 Old_S := Entity (Name (N));
4528 if not Is_Frozen (Old_S)
4529 and then Operating_Mode /= Check_Semantics
4531 Append_Freeze_Action (Old_S, B_Node);
4533 Insert_After (N, B_Node);
4537 if Is_Intrinsic_Subprogram (Old_S)
4538 and then not In_Instance
4539 and then not Relaxed_RM_Semantics
4542 ("subprogram used in renaming_as_body cannot be intrinsic",
4547 Insert_After (N, B_Node);
4551 end Check_Frozen_Renaming;
4553 -------------------------------
4554 -- Set_Entity_Or_Discriminal --
4555 -------------------------------
4557 procedure Set_Entity_Or_Discriminal (N : Node_Id; E : Entity_Id) is
4561 -- If the entity is not a discriminant, or else expansion is disabled,
4562 -- simply set the entity.
4564 if not In_Spec_Expression
4565 or else Ekind (E) /= E_Discriminant
4566 or else Inside_A_Generic
4568 Set_Entity_With_Checks (N, E);
4570 -- The replacement of a discriminant by the corresponding discriminal
4571 -- is not done for a task discriminant that appears in a default
4572 -- expression of an entry parameter. See Exp_Ch2.Expand_Discriminant
4573 -- for details on their handling.
4575 elsif Is_Concurrent_Type (Scope (E)) then
4578 and then Nkind (P) not in
4579 N_Parameter_Specification | N_Component_Declaration
4585 and then Nkind (P) = N_Parameter_Specification
4590 Set_Entity (N, Discriminal (E));
4593 -- Otherwise, this is a discriminant in a context in which
4594 -- it is a reference to the corresponding parameter of the
4595 -- init proc for the enclosing type.
4598 Set_Entity (N, Discriminal (E));
4600 end Set_Entity_Or_Discriminal;
4602 -----------------------------------
4603 -- Check_In_Previous_With_Clause --
4604 -----------------------------------
4606 procedure Check_In_Previous_With_Clause
4610 Pack : constant Entity_Id := Entity (Original_Node (Nam));
4615 Item := First (Context_Items (Parent (N)));
4616 while Present (Item) and then Item /= N loop
4617 if Nkind (Item) = N_With_Clause
4619 -- Protect the frontend against previous critical errors
4621 and then Nkind (Name (Item)) /= N_Selected_Component
4622 and then Entity (Name (Item)) = Pack
4626 -- Find root library unit in with_clause
4628 while Nkind (Par) = N_Expanded_Name loop
4629 Par := Prefix (Par);
4632 if Is_Child_Unit (Entity (Original_Node (Par))) then
4633 Error_Msg_NE ("& is not directly visible", Par, Entity (Par));
4642 -- On exit, package is not mentioned in a previous with_clause.
4643 -- Check if its prefix is.
4645 if Nkind (Nam) = N_Expanded_Name then
4646 Check_In_Previous_With_Clause (N, Prefix (Nam));
4648 elsif Pack /= Any_Id then
4649 Error_Msg_NE ("& is not visible", Nam, Pack);
4651 end Check_In_Previous_With_Clause;
4653 ---------------------------------
4654 -- Check_Library_Unit_Renaming --
4655 ---------------------------------
4657 procedure Check_Library_Unit_Renaming (N : Node_Id; Old_E : Entity_Id) is
4661 if Nkind (Parent (N)) /= N_Compilation_Unit then
4664 -- Check for library unit. Note that we used to check for the scope
4665 -- being Standard here, but that was wrong for Standard itself.
4667 elsif not Is_Compilation_Unit (Old_E)
4668 and then not Is_Child_Unit (Old_E)
4670 Error_Msg_N ("renamed unit must be a library unit", Name (N));
4672 -- Entities defined in Standard (operators and boolean literals) cannot
4673 -- be renamed as library units.
4675 elsif Scope (Old_E) = Standard_Standard
4676 and then Sloc (Old_E) = Standard_Location
4678 Error_Msg_N ("renamed unit must be a library unit", Name (N));
4680 elsif Present (Parent_Spec (N))
4681 and then Nkind (Unit (Parent_Spec (N))) = N_Generic_Package_Declaration
4682 and then not Is_Child_Unit (Old_E)
4685 ("renamed unit must be a child unit of generic parent", Name (N));
4687 elsif Nkind (N) in N_Generic_Renaming_Declaration
4688 and then Nkind (Name (N)) = N_Expanded_Name
4689 and then Is_Generic_Instance (Entity (Prefix (Name (N))))
4690 and then Is_Generic_Unit (Old_E)
4693 ("renamed generic unit must be a library unit", Name (N));
4695 elsif Is_Package_Or_Generic_Package (Old_E) then
4697 -- Inherit categorization flags
4699 New_E := Defining_Entity (N);
4700 Set_Is_Pure (New_E, Is_Pure (Old_E));
4701 Set_Is_Preelaborated (New_E, Is_Preelaborated (Old_E));
4702 Set_Is_Remote_Call_Interface (New_E,
4703 Is_Remote_Call_Interface (Old_E));
4704 Set_Is_Remote_Types (New_E, Is_Remote_Types (Old_E));
4705 Set_Is_Shared_Passive (New_E, Is_Shared_Passive (Old_E));
4707 end Check_Library_Unit_Renaming;
4709 ------------------------
4710 -- Enclosing_Instance --
4711 ------------------------
4713 function Enclosing_Instance return Entity_Id is
4717 if not Is_Generic_Instance (Current_Scope) then
4721 S := Scope (Current_Scope);
4722 while S /= Standard_Standard loop
4723 if Is_Generic_Instance (S) then
4731 end Enclosing_Instance;
4737 procedure End_Scope is
4743 Id := First_Entity (Current_Scope);
4744 while Present (Id) loop
4745 -- An entity in the current scope is not necessarily the first one
4746 -- on its homonym chain. Find its predecessor if any,
4747 -- If it is an internal entity, it will not be in the visibility
4748 -- chain altogether, and there is nothing to unchain.
4750 if Id /= Current_Entity (Id) then
4751 Prev := Current_Entity (Id);
4752 while Present (Prev)
4753 and then Present (Homonym (Prev))
4754 and then Homonym (Prev) /= Id
4756 Prev := Homonym (Prev);
4759 -- Skip to end of loop if Id is not in the visibility chain
4761 if No (Prev) or else Homonym (Prev) /= Id then
4769 Set_Is_Immediately_Visible (Id, False);
4771 Outer := Homonym (Id);
4772 while Present (Outer) and then Scope (Outer) = Current_Scope loop
4773 Outer := Homonym (Outer);
4776 -- Reset homonym link of other entities, but do not modify link
4777 -- between entities in current scope, so that the back-end can have
4778 -- a proper count of local overloadings.
4781 Set_Name_Entity_Id (Chars (Id), Outer);
4783 elsif Scope (Prev) /= Scope (Id) then
4784 Set_Homonym (Prev, Outer);
4791 -- If the scope generated freeze actions, place them before the
4792 -- current declaration and analyze them. Type declarations and
4793 -- the bodies of initialization procedures can generate such nodes.
4794 -- We follow the parent chain until we reach a list node, which is
4795 -- the enclosing list of declarations. If the list appears within
4796 -- a protected definition, move freeze nodes outside the protected
4800 (Scope_Stack.Table (Scope_Stack.Last).Pending_Freeze_Actions)
4804 L : constant List_Id := Scope_Stack.Table
4805 (Scope_Stack.Last).Pending_Freeze_Actions;
4808 if Is_Itype (Current_Scope) then
4809 Decl := Associated_Node_For_Itype (Current_Scope);
4811 Decl := Parent (Current_Scope);
4816 while not (Is_List_Member (Decl))
4817 or else Nkind (Parent (Decl)) in N_Protected_Definition
4820 Decl := Parent (Decl);
4823 Insert_List_Before_And_Analyze (Decl, L);
4831 ---------------------
4832 -- End_Use_Clauses --
4833 ---------------------
4835 procedure End_Use_Clauses (Clause : Node_Id) is
4839 -- Remove use_type_clauses first, because they affect the visibility of
4840 -- operators in subsequent used packages.
4843 while Present (U) loop
4844 if Nkind (U) = N_Use_Type_Clause then
4848 Next_Use_Clause (U);
4852 while Present (U) loop
4853 if Nkind (U) = N_Use_Package_Clause then
4854 End_Use_Package (U);
4857 Next_Use_Clause (U);
4859 end End_Use_Clauses;
4861 ---------------------
4862 -- End_Use_Package --
4863 ---------------------
4865 procedure End_Use_Package (N : Node_Id) is
4867 Pack_Name : Node_Id;
4871 function Is_Primitive_Operator_In_Use
4873 F : Entity_Id) return Boolean;
4874 -- Check whether Op is a primitive operator of a use-visible type
4876 ----------------------------------
4877 -- Is_Primitive_Operator_In_Use --
4878 ----------------------------------
4880 function Is_Primitive_Operator_In_Use
4882 F : Entity_Id) return Boolean
4884 T : constant Entity_Id := Base_Type (Etype (F));
4886 return In_Use (T) and then Scope (T) = Scope (Op);
4887 end Is_Primitive_Operator_In_Use;
4889 -- Start of processing for End_Use_Package
4892 Pack_Name := Name (N);
4894 -- Test that Pack_Name actually denotes a package before processing
4896 if Is_Entity_Name (Pack_Name)
4897 and then Ekind (Entity (Pack_Name)) = E_Package
4899 Pack := Entity (Pack_Name);
4901 if In_Open_Scopes (Pack) then
4904 elsif not Redundant_Use (Pack_Name) then
4905 Set_In_Use (Pack, False);
4906 Set_Current_Use_Clause (Pack, Empty);
4908 Id := First_Entity (Pack);
4909 while Present (Id) loop
4911 -- Preserve use-visibility of operators that are primitive
4912 -- operators of a type that is use-visible through an active
4915 if Nkind (Id) = N_Defining_Operator_Symbol
4917 (Is_Primitive_Operator_In_Use (Id, First_Formal (Id))
4919 (Present (Next_Formal (First_Formal (Id)))
4921 Is_Primitive_Operator_In_Use
4922 (Id, Next_Formal (First_Formal (Id)))))
4926 Set_Is_Potentially_Use_Visible (Id, False);
4929 if Is_Private_Type (Id)
4930 and then Present (Full_View (Id))
4932 Set_Is_Potentially_Use_Visible (Full_View (Id), False);
4938 if Present (Renamed_Object (Pack)) then
4939 Set_In_Use (Renamed_Object (Pack), False);
4940 Set_Current_Use_Clause (Renamed_Object (Pack), Empty);
4943 if Chars (Pack) = Name_System
4944 and then Scope (Pack) = Standard_Standard
4945 and then Present_System_Aux
4947 Id := First_Entity (System_Aux_Id);
4948 while Present (Id) loop
4949 Set_Is_Potentially_Use_Visible (Id, False);
4951 if Is_Private_Type (Id)
4952 and then Present (Full_View (Id))
4954 Set_Is_Potentially_Use_Visible (Full_View (Id), False);
4960 Set_In_Use (System_Aux_Id, False);
4963 Set_Redundant_Use (Pack_Name, False);
4967 if Present (Hidden_By_Use_Clause (N)) then
4968 Elmt := First_Elmt (Hidden_By_Use_Clause (N));
4969 while Present (Elmt) loop
4971 E : constant Entity_Id := Node (Elmt);
4974 -- Reset either Use_Visibility or Direct_Visibility, depending
4975 -- on how the entity was hidden by the use clause.
4977 if In_Use (Scope (E))
4978 and then Used_As_Generic_Actual (Scope (E))
4980 Set_Is_Potentially_Use_Visible (Node (Elmt));
4982 Set_Is_Immediately_Visible (Node (Elmt));
4989 Set_Hidden_By_Use_Clause (N, No_Elist);
4991 end End_Use_Package;
4997 procedure End_Use_Type (N : Node_Id) is
5002 -- Start of processing for End_Use_Type
5005 Id := Subtype_Mark (N);
5007 -- A call to Rtsfind may occur while analyzing a use_type_clause, in
5008 -- which case the type marks are not resolved yet, so guard against that
5011 if Is_Entity_Name (Id) and then Present (Entity (Id)) then
5014 if T = Any_Type or else From_Limited_With (T) then
5017 -- Note that the use_type_clause may mention a subtype of the type
5018 -- whose primitive operations have been made visible. Here as
5019 -- elsewhere, it is the base type that matters for visibility.
5021 elsif In_Open_Scopes (Scope (Base_Type (T))) then
5024 elsif not Redundant_Use (Id) then
5025 Set_In_Use (T, False);
5026 Set_In_Use (Base_Type (T), False);
5027 Set_Current_Use_Clause (T, Empty);
5028 Set_Current_Use_Clause (Base_Type (T), Empty);
5030 -- See Use_One_Type for the rationale. This is a bit on the naive
5031 -- side, but should be good enough in practice.
5033 if Is_Tagged_Type (T) then
5034 Set_In_Use (Class_Wide_Type (T), False);
5039 if Is_Empty_Elmt_List (Used_Operations (N)) then
5043 Elmt := First_Elmt (Used_Operations (N));
5044 while Present (Elmt) loop
5045 Set_Is_Potentially_Use_Visible (Node (Elmt), False);
5051 --------------------
5052 -- Entity_Of_Unit --
5053 --------------------
5055 function Entity_Of_Unit (U : Node_Id) return Entity_Id is
5057 if Nkind (U) = N_Package_Instantiation and then Analyzed (U) then
5058 return Defining_Entity (Instance_Spec (U));
5060 return Defining_Entity (U);
5064 ----------------------
5065 -- Find_Direct_Name --
5066 ----------------------
5068 procedure Find_Direct_Name (N : Node_Id) is
5073 Homonyms : Entity_Id;
5074 -- Saves start of homonym chain
5076 Inst : Entity_Id := Empty;
5077 -- Enclosing instance, if any
5079 Nvis_Entity : Boolean;
5080 -- Set True to indicate that there is at least one entity on the homonym
5081 -- chain which, while not visible, is visible enough from the user point
5082 -- of view to warrant an error message of "not visible" rather than
5085 Nvis_Is_Private_Subprg : Boolean := False;
5086 -- Ada 2005 (AI-262): Set True to indicate that a form of Beaujolais
5087 -- effect concerning library subprograms has been detected. Used to
5088 -- generate the precise error message.
5090 function From_Actual_Package (E : Entity_Id) return Boolean;
5091 -- Returns true if the entity is an actual for a package that is itself
5092 -- an actual for a formal package of the current instance. Such an
5093 -- entity requires special handling because it may be use-visible but
5094 -- hides directly visible entities defined outside the instance, because
5095 -- the corresponding formal did so in the generic.
5097 function Is_Actual_Parameter return Boolean;
5098 -- This function checks if the node N is an identifier that is an actual
5099 -- parameter of a procedure call. If so it returns True, otherwise it
5100 -- return False. The reason for this check is that at this stage we do
5101 -- not know what procedure is being called if the procedure might be
5102 -- overloaded, so it is premature to go setting referenced flags or
5103 -- making calls to Generate_Reference. We will wait till Resolve_Actuals
5104 -- for that processing.
5105 -- Note: there is a similar routine Sem_Util.Is_Actual_Parameter, but
5106 -- it works for both function and procedure calls, while here we are
5107 -- only concerned with procedure calls (and with entry calls as well,
5108 -- but they are parsed as procedure calls and only later rewritten to
5111 function Known_But_Invisible (E : Entity_Id) return Boolean;
5112 -- This function determines whether a reference to the entity E, which
5113 -- is not visible, can reasonably be considered to be known to the
5114 -- writer of the reference. This is a heuristic test, used only for
5115 -- the purposes of figuring out whether we prefer to complain that an
5116 -- entity is undefined or invisible (and identify the declaration of
5117 -- the invisible entity in the latter case). The point here is that we
5118 -- don't want to complain that something is invisible and then point to
5119 -- something entirely mysterious to the writer.
5121 procedure Nvis_Messages;
5122 -- Called if there are no visible entries for N, but there is at least
5123 -- one non-directly visible, or hidden declaration. This procedure
5124 -- outputs an appropriate set of error messages.
5126 procedure Undefined (Nvis : Boolean);
5127 -- This function is called if the current node has no corresponding
5128 -- visible entity or entities. The value set in Msg indicates whether
5129 -- an error message was generated (multiple error messages for the
5130 -- same variable are generally suppressed, see body for details).
5131 -- Msg is True if an error message was generated, False if not. This
5132 -- value is used by the caller to determine whether or not to output
5133 -- additional messages where appropriate. The parameter is set False
5134 -- to get the message "X is undefined", and True to get the message
5135 -- "X is not visible".
5137 -------------------------
5138 -- From_Actual_Package --
5139 -------------------------
5141 function From_Actual_Package (E : Entity_Id) return Boolean is
5142 Scop : constant Entity_Id := Scope (E);
5143 -- Declared scope of candidate entity
5145 function Declared_In_Actual (Pack : Entity_Id) return Boolean;
5146 -- Recursive function that does the work and examines actuals of
5147 -- actual packages of current instance.
5149 ------------------------
5150 -- Declared_In_Actual --
5151 ------------------------
5153 function Declared_In_Actual (Pack : Entity_Id) return Boolean is
5157 if No (Associated_Formal_Package (Pack)) then
5161 Act := First_Entity (Pack);
5162 while Present (Act) loop
5163 if Renamed_Object (Pack) = Scop then
5166 -- Check for end of list of actuals
5168 elsif Ekind (Act) = E_Package
5169 and then Renamed_Object (Act) = Pack
5173 elsif Ekind (Act) = E_Package
5174 and then Declared_In_Actual (Act)
5184 end Declared_In_Actual;
5190 -- Start of processing for From_Actual_Package
5193 if not In_Instance then
5197 Inst := Current_Scope;
5198 while Present (Inst)
5199 and then Ekind (Inst) /= E_Package
5200 and then not Is_Generic_Instance (Inst)
5202 Inst := Scope (Inst);
5209 Act := First_Entity (Inst);
5210 while Present (Act) loop
5211 if Ekind (Act) = E_Package
5212 and then Declared_In_Actual (Act)
5222 end From_Actual_Package;
5224 -------------------------
5225 -- Is_Actual_Parameter --
5226 -------------------------
5228 function Is_Actual_Parameter return Boolean is
5230 if Nkind (N) = N_Identifier then
5231 case Nkind (Parent (N)) is
5232 when N_Procedure_Call_Statement =>
5233 return Is_List_Member (N)
5234 and then List_Containing (N) =
5235 Parameter_Associations (Parent (N));
5237 when N_Parameter_Association =>
5238 return N = Explicit_Actual_Parameter (Parent (N))
5239 and then Nkind (Parent (Parent (N))) =
5240 N_Procedure_Call_Statement;
5248 end Is_Actual_Parameter;
5250 -------------------------
5251 -- Known_But_Invisible --
5252 -------------------------
5254 function Known_But_Invisible (E : Entity_Id) return Boolean is
5255 Fname : File_Name_Type;
5258 -- Entities in Standard are always considered to be known
5260 if Sloc (E) <= Standard_Location then
5263 -- An entity that does not come from source is always considered
5264 -- to be unknown, since it is an artifact of code expansion.
5266 elsif not Comes_From_Source (E) then
5269 -- In gnat internal mode, we consider all entities known. The
5270 -- historical reason behind this discrepancy is not known??? But the
5271 -- only effect is to modify the error message given, so it is not
5272 -- critical. Since it only affects the exact wording of error
5273 -- messages in illegal programs, we do not mention this as an
5274 -- effect of -gnatg, since it is not a language modification.
5276 elsif GNAT_Mode then
5280 -- Here we have an entity that is not from package Standard, and
5281 -- which comes from Source. See if it comes from an internal file.
5283 Fname := Unit_File_Name (Get_Source_Unit (E));
5285 -- Case of from internal file
5287 if In_Internal_Unit (E) then
5289 -- Private part entities in internal files are never considered
5290 -- to be known to the writer of normal application code.
5292 if Is_Hidden (E) then
5296 -- Entities from System packages other than System and
5297 -- System.Storage_Elements are not considered to be known.
5298 -- System.Auxxxx files are also considered known to the user.
5300 -- Should refine this at some point to generally distinguish
5301 -- between known and unknown internal files ???
5303 Get_Name_String (Fname);
5308 Name_Buffer (1 .. 2) /= "s-"
5310 Name_Buffer (3 .. 8) = "stoele"
5312 Name_Buffer (3 .. 5) = "aux";
5314 -- If not an internal file, then entity is definitely known, even if
5315 -- it is in a private part (the message generated will note that it
5316 -- is in a private part).
5321 end Known_But_Invisible;
5327 procedure Nvis_Messages is
5328 Comp_Unit : Node_Id;
5330 Found : Boolean := False;
5331 Hidden : Boolean := False;
5335 -- Ada 2005 (AI-262): Generate a precise error concerning the
5336 -- Beaujolais effect that was previously detected
5338 if Nvis_Is_Private_Subprg then
5340 pragma Assert (Nkind (E2) = N_Defining_Identifier
5341 and then Ekind (E2) = E_Function
5342 and then Scope (E2) = Standard_Standard
5343 and then Has_Private_With (E2));
5345 -- Find the sloc corresponding to the private with'ed unit
5347 Comp_Unit := Cunit (Current_Sem_Unit);
5348 Error_Msg_Sloc := No_Location;
5350 Item := First (Context_Items (Comp_Unit));
5351 while Present (Item) loop
5352 if Nkind (Item) = N_With_Clause
5353 and then Private_Present (Item)
5354 and then Entity (Name (Item)) = E2
5356 Error_Msg_Sloc := Sloc (Item);
5363 pragma Assert (Error_Msg_Sloc /= No_Location);
5365 Error_Msg_N ("(Ada 2005): hidden by private with clause #", N);
5369 Undefined (Nvis => True);
5373 -- First loop does hidden declarations
5376 while Present (Ent) loop
5377 if Is_Potentially_Use_Visible (Ent) then
5379 Error_Msg_N -- CODEFIX
5380 ("multiple use clauses cause hiding!", N);
5384 Error_Msg_Sloc := Sloc (Ent);
5385 Error_Msg_N -- CODEFIX
5386 ("hidden declaration#!", N);
5389 Ent := Homonym (Ent);
5392 -- If we found hidden declarations, then that's enough, don't
5393 -- bother looking for non-visible declarations as well.
5399 -- Second loop does non-directly visible declarations
5402 while Present (Ent) loop
5403 if not Is_Potentially_Use_Visible (Ent) then
5405 -- Do not bother the user with unknown entities
5407 if not Known_But_Invisible (Ent) then
5411 Error_Msg_Sloc := Sloc (Ent);
5413 -- Output message noting that there is a non-visible
5414 -- declaration, distinguishing the private part case.
5416 if Is_Hidden (Ent) then
5417 Error_Msg_N ("non-visible (private) declaration#!", N);
5419 -- If the entity is declared in a generic package, it
5420 -- cannot be visible, so there is no point in adding it
5421 -- to the list of candidates if another homograph from a
5422 -- non-generic package has been seen.
5424 elsif Ekind (Scope (Ent)) = E_Generic_Package
5430 Error_Msg_N -- CODEFIX
5431 ("non-visible declaration#!", N);
5433 if Ekind (Scope (Ent)) /= E_Generic_Package then
5437 if Is_Compilation_Unit (Ent)
5439 Nkind (Parent (Parent (N))) = N_Use_Package_Clause
5441 Error_Msg_Qual_Level := 99;
5442 Error_Msg_NE -- CODEFIX
5443 ("\\missing `WITH &;`", N, Ent);
5444 Error_Msg_Qual_Level := 0;
5447 if Ekind (Ent) = E_Discriminant
5448 and then Present (Corresponding_Discriminant (Ent))
5449 and then Scope (Corresponding_Discriminant (Ent)) =
5453 ("inherited discriminant not allowed here" &
5454 " (RM 3.8 (12), 3.8.1 (6))!", N);
5458 -- Set entity and its containing package as referenced. We
5459 -- can't be sure of this, but this seems a better choice
5460 -- to avoid unused entity messages.
5462 if Comes_From_Source (Ent) then
5463 Set_Referenced (Ent);
5464 Set_Referenced (Cunit_Entity (Get_Source_Unit (Ent)));
5469 Ent := Homonym (Ent);
5478 procedure Undefined (Nvis : Boolean) is
5479 Emsg : Error_Msg_Id;
5482 -- We should never find an undefined internal name. If we do, then
5483 -- see if we have previous errors. If so, ignore on the grounds that
5484 -- it is probably a cascaded message (e.g. a block label from a badly
5485 -- formed block). If no previous errors, then we have a real internal
5486 -- error of some kind so raise an exception.
5488 if Is_Internal_Name (Chars (N)) then
5489 if Total_Errors_Detected /= 0 then
5492 raise Program_Error;
5496 -- A very specialized error check, if the undefined variable is
5497 -- a case tag, and the case type is an enumeration type, check
5498 -- for a possible misspelling, and if so, modify the identifier
5500 -- Named aggregate should also be handled similarly ???
5502 if Nkind (N) = N_Identifier
5503 and then Nkind (Parent (N)) = N_Case_Statement_Alternative
5506 Case_Stm : constant Node_Id := Parent (Parent (N));
5507 Case_Typ : constant Entity_Id := Etype (Expression (Case_Stm));
5512 if Is_Enumeration_Type (Case_Typ)
5513 and then not Is_Standard_Character_Type (Case_Typ)
5515 Lit := First_Literal (Case_Typ);
5516 Get_Name_String (Chars (Lit));
5518 if Chars (Lit) /= Chars (N)
5519 and then Is_Bad_Spelling_Of (Chars (N), Chars (Lit))
5521 Error_Msg_Node_2 := Lit;
5522 Error_Msg_N -- CODEFIX
5523 ("& is undefined, assume misspelling of &", N);
5524 Rewrite (N, New_Occurrence_Of (Lit, Sloc (N)));
5533 -- Normal processing
5535 Set_Entity (N, Any_Id);
5536 Set_Etype (N, Any_Type);
5538 -- We use the table Urefs to keep track of entities for which we
5539 -- have issued errors for undefined references. Multiple errors
5540 -- for a single name are normally suppressed, however we modify
5541 -- the error message to alert the programmer to this effect.
5543 for J in Urefs.First .. Urefs.Last loop
5544 if Chars (N) = Chars (Urefs.Table (J).Node) then
5545 if Urefs.Table (J).Err /= No_Error_Msg
5546 and then Sloc (N) /= Urefs.Table (J).Loc
5548 Error_Msg_Node_1 := Urefs.Table (J).Node;
5550 if Urefs.Table (J).Nvis then
5551 Change_Error_Text (Urefs.Table (J).Err,
5552 "& is not visible (more references follow)");
5554 Change_Error_Text (Urefs.Table (J).Err,
5555 "& is undefined (more references follow)");
5558 Urefs.Table (J).Err := No_Error_Msg;
5561 -- Although we will set Msg False, and thus suppress the
5562 -- message, we also set Error_Posted True, to avoid any
5563 -- cascaded messages resulting from the undefined reference.
5566 Set_Error_Posted (N);
5571 -- If entry not found, this is first undefined occurrence
5574 Error_Msg_N ("& is not visible!", N);
5578 Error_Msg_N ("& is undefined!", N);
5581 -- A very bizarre special check, if the undefined identifier
5582 -- is Put or Put_Line, then add a special error message (since
5583 -- this is a very common error for beginners to make).
5585 if Chars (N) in Name_Put | Name_Put_Line then
5586 Error_Msg_N -- CODEFIX
5587 ("\\possible missing `WITH Ada.Text_'I'O; " &
5588 "USE Ada.Text_'I'O`!", N);
5590 -- Another special check if N is the prefix of a selected
5591 -- component which is a known unit: add message complaining
5592 -- about missing with for this unit.
5594 elsif Nkind (Parent (N)) = N_Selected_Component
5595 and then N = Prefix (Parent (N))
5596 and then Is_Known_Unit (Parent (N))
5599 P : Node_Id := Parent (N);
5601 Error_Msg_Name_1 := Chars (N);
5602 Error_Msg_Name_2 := Chars (Selector_Name (P));
5604 if Nkind (Parent (P)) = N_Selected_Component
5605 and then Is_Known_Unit (Parent (P))
5608 Error_Msg_Name_3 := Chars (Selector_Name (P));
5609 Error_Msg_N -- CODEFIX
5610 ("\\missing `WITH %.%.%;`", N);
5613 Error_Msg_N -- CODEFIX
5614 ("\\missing `WITH %.%;`", N);
5619 -- Now check for possible misspellings
5623 Ematch : Entity_Id := Empty;
5625 for Nam in First_Name_Id .. Last_Name_Id loop
5626 E := Get_Name_Entity_Id (Nam);
5629 and then (Is_Immediately_Visible (E)
5631 Is_Potentially_Use_Visible (E))
5633 if Is_Bad_Spelling_Of (Chars (N), Nam) then
5640 if Present (Ematch) then
5641 Error_Msg_NE -- CODEFIX
5642 ("\possible misspelling of&", N, Ematch);
5647 -- Make entry in undefined references table unless the full errors
5648 -- switch is set, in which case by refraining from generating the
5649 -- table entry we guarantee that we get an error message for every
5650 -- undefined reference. The entry is not added if we are ignoring
5653 if not All_Errors_Mode
5654 and then Ignore_Errors_Enable = 0
5655 and then not Get_Ignore_Errors
5669 Nested_Inst : Entity_Id := Empty;
5670 -- The entity of a nested instance which appears within Inst (if any)
5672 -- Start of processing for Find_Direct_Name
5675 -- If the entity pointer is already set, this is an internal node, or
5676 -- a node that is analyzed more than once, after a tree modification.
5677 -- In such a case there is no resolution to perform, just set the type.
5679 if Present (Entity (N)) then
5680 if Is_Type (Entity (N)) then
5681 Set_Etype (N, Entity (N));
5683 -- The exception to this general rule are constants associated with
5684 -- discriminals of protected types because for each protected op
5685 -- a new set of discriminals is internally created by the frontend
5686 -- (see Exp_Ch9.Set_Discriminals), and the current decoration of the
5687 -- entity pointer may have been set as part of a preanalysis, where
5688 -- discriminals still reference the first subprogram or entry to be
5689 -- expanded (see Expand_Protected_Body_Declarations).
5692 and then Ekind (Entity (N)) = E_Constant
5693 and then Present (Discriminal_Link (Entity (N)))
5694 and then Is_Protected_Type (Scope (Discriminal_Link (Entity (N))))
5700 Entyp : constant Entity_Id := Etype (Entity (N));
5703 -- One special case here. If the Etype field is already set,
5704 -- and references the packed array type corresponding to the
5705 -- etype of the referenced entity, then leave it alone. This
5706 -- happens for trees generated from Exp_Pakd, where expressions
5707 -- can be deliberately "mis-typed" to the packed array type.
5709 if Is_Packed_Array (Entyp)
5710 and then Present (Etype (N))
5711 and then Etype (N) = Packed_Array_Impl_Type (Entyp)
5715 -- If not that special case, then just reset the Etype
5718 Set_Etype (N, Etype (Entity (N)));
5723 -- Although the marking of use clauses happens at the end of
5724 -- Find_Direct_Name, a certain case where a generic actual satisfies
5725 -- a use clause must be checked here due to how the generic machinery
5726 -- handles the analysis of said actuals.
5729 and then Nkind (Parent (N)) = N_Generic_Association
5731 Mark_Use_Clauses (Entity (N));
5739 -- Preserve relevant elaboration-related attributes of the context which
5740 -- are no longer available or very expensive to recompute once analysis,
5741 -- resolution, and expansion are over.
5743 if Nkind (N) = N_Identifier then
5744 Mark_Elaboration_Attributes
5751 -- Here if Entity pointer was not set, we need full visibility analysis
5752 -- First we generate debugging output if the debug E flag is set.
5754 if Debug_Flag_E then
5755 Write_Str ("Looking for ");
5756 Write_Name (Chars (N));
5760 Homonyms := Current_Entity (N);
5761 Nvis_Entity := False;
5764 while Present (E) loop
5766 -- If entity is immediately visible or potentially use visible, then
5767 -- process the entity and we are done.
5769 if Is_Immediately_Visible (E) then
5770 goto Immediately_Visible_Entity;
5772 elsif Is_Potentially_Use_Visible (E) then
5773 goto Potentially_Use_Visible_Entity;
5775 -- Note if a known but invisible entity encountered
5777 elsif Known_But_Invisible (E) then
5778 Nvis_Entity := True;
5781 -- Move to next entity in chain and continue search
5786 -- If no entries on homonym chain that were potentially visible,
5787 -- and no entities reasonably considered as non-visible, then
5788 -- we have a plain undefined reference, with no additional
5789 -- explanation required.
5791 if not Nvis_Entity then
5792 Undefined (Nvis => False);
5794 -- Otherwise there is at least one entry on the homonym chain that
5795 -- is reasonably considered as being known and non-visible.
5803 -- Processing for a potentially use visible entry found. We must search
5804 -- the rest of the homonym chain for two reasons. First, if there is a
5805 -- directly visible entry, then none of the potentially use-visible
5806 -- entities are directly visible (RM 8.4(10)). Second, we need to check
5807 -- for the case of multiple potentially use-visible entries hiding one
5808 -- another and as a result being non-directly visible (RM 8.4(11)).
5810 <<Potentially_Use_Visible_Entity>> declare
5811 Only_One_Visible : Boolean := True;
5812 All_Overloadable : Boolean := Is_Overloadable (E);
5816 while Present (E2) loop
5817 if Is_Immediately_Visible (E2) then
5819 -- If the use-visible entity comes from the actual for a
5820 -- formal package, it hides a directly visible entity from
5821 -- outside the instance.
5823 if From_Actual_Package (E)
5824 and then Scope_Depth (Scope (E2)) < Scope_Depth (Inst)
5829 goto Immediately_Visible_Entity;
5832 elsif Is_Potentially_Use_Visible (E2) then
5833 Only_One_Visible := False;
5834 All_Overloadable := All_Overloadable and Is_Overloadable (E2);
5836 -- Ada 2005 (AI-262): Protect against a form of Beaujolais effect
5837 -- that can occur in private_with clauses. Example:
5840 -- private with B; package A is
5841 -- package C is function B return Integer;
5843 -- V1 : Integer := B;
5844 -- private function B return Integer;
5845 -- V2 : Integer := B;
5848 -- V1 resolves to A.B, but V2 resolves to library unit B
5850 elsif Ekind (E2) = E_Function
5851 and then Scope (E2) = Standard_Standard
5852 and then Has_Private_With (E2)
5854 Only_One_Visible := False;
5855 All_Overloadable := False;
5856 Nvis_Is_Private_Subprg := True;
5863 -- On falling through this loop, we have checked that there are no
5864 -- immediately visible entities. Only_One_Visible is set if exactly
5865 -- one potentially use visible entity exists. All_Overloadable is
5866 -- set if all the potentially use visible entities are overloadable.
5867 -- The condition for legality is that either there is one potentially
5868 -- use visible entity, or if there is more than one, then all of them
5869 -- are overloadable.
5871 if Only_One_Visible or All_Overloadable then
5874 -- If there is more than one potentially use-visible entity and at
5875 -- least one of them non-overloadable, we have an error (RM 8.4(11)).
5876 -- Note that E points to the first such entity on the homonym list.
5879 -- If one of the entities is declared in an actual package, it
5880 -- was visible in the generic, and takes precedence over other
5881 -- entities that are potentially use-visible. The same applies
5882 -- if the entity is declared in a local instantiation of the
5883 -- current instance.
5887 -- Find the current instance
5889 Inst := Current_Scope;
5890 while Present (Inst) and then Inst /= Standard_Standard loop
5891 if Is_Generic_Instance (Inst) then
5895 Inst := Scope (Inst);
5898 -- Reexamine the candidate entities, giving priority to those
5899 -- that were visible within the generic.
5902 while Present (E2) loop
5903 Nested_Inst := Nearest_Enclosing_Instance (E2);
5905 -- The entity is declared within an actual package, or in a
5906 -- nested instance. The ">=" accounts for the case where the
5907 -- current instance and the nested instance are the same.
5909 if From_Actual_Package (E2)
5910 or else (Present (Nested_Inst)
5911 and then Scope_Depth (Nested_Inst) >=
5924 elsif Is_Predefined_Unit (Current_Sem_Unit) then
5925 -- A use clause in the body of a system file creates conflict
5926 -- with some entity in a user scope, while rtsfind is active.
5927 -- Keep only the entity coming from another predefined unit.
5930 while Present (E2) loop
5931 if In_Predefined_Unit (E2) then
5939 -- Entity must exist because predefined unit is correct
5941 raise Program_Error;
5950 -- Come here with E set to the first immediately visible entity on
5951 -- the homonym chain. This is the one we want unless there is another
5952 -- immediately visible entity further on in the chain for an inner
5953 -- scope (RM 8.3(8)).
5955 <<Immediately_Visible_Entity>> declare
5960 -- Find scope level of initial entity. When compiling through
5961 -- Rtsfind, the previous context is not completely invisible, and
5962 -- an outer entity may appear on the chain, whose scope is below
5963 -- the entry for Standard that delimits the current scope stack.
5964 -- Indicate that the level for this spurious entry is outside of
5965 -- the current scope stack.
5967 Level := Scope_Stack.Last;
5969 Scop := Scope_Stack.Table (Level).Entity;
5970 exit when Scop = Scope (E);
5972 exit when Scop = Standard_Standard;
5975 -- Now search remainder of homonym chain for more inner entry
5976 -- If the entity is Standard itself, it has no scope, and we
5977 -- compare it with the stack entry directly.
5980 while Present (E2) loop
5981 if Is_Immediately_Visible (E2) then
5983 -- If a generic package contains a local declaration that
5984 -- has the same name as the generic, there may be a visibility
5985 -- conflict in an instance, where the local declaration must
5986 -- also hide the name of the corresponding package renaming.
5987 -- We check explicitly for a package declared by a renaming,
5988 -- whose renamed entity is an instance that is on the scope
5989 -- stack, and that contains a homonym in the same scope. Once
5990 -- we have found it, we know that the package renaming is not
5991 -- immediately visible, and that the identifier denotes the
5992 -- other entity (and its homonyms if overloaded).
5994 if Scope (E) = Scope (E2)
5995 and then Ekind (E) = E_Package
5996 and then Present (Renamed_Object (E))
5997 and then Is_Generic_Instance (Renamed_Object (E))
5998 and then In_Open_Scopes (Renamed_Object (E))
5999 and then Comes_From_Source (N)
6001 Set_Is_Immediately_Visible (E, False);
6005 for J in Level + 1 .. Scope_Stack.Last loop
6006 if Scope_Stack.Table (J).Entity = Scope (E2)
6007 or else Scope_Stack.Table (J).Entity = E2
6020 -- At the end of that loop, E is the innermost immediately
6021 -- visible entity, so we are all set.
6024 -- Come here with entity found, and stored in E
6028 -- Check violation of No_Wide_Characters restriction
6030 Check_Wide_Character_Restriction (E, N);
6032 -- When distribution features are available (Get_PCS_Name /=
6033 -- Name_No_DSA), a remote access-to-subprogram type is converted
6034 -- into a record type holding whatever information is needed to
6035 -- perform a remote call on an RCI subprogram. In that case we
6036 -- rewrite any occurrence of the RAS type into the equivalent record
6037 -- type here. 'Access attribute references and RAS dereferences are
6038 -- then implemented using specific TSSs. However when distribution is
6039 -- not available (case of Get_PCS_Name = Name_No_DSA), we bypass the
6040 -- generation of these TSSs, and we must keep the RAS type in its
6041 -- original access-to-subprogram form (since all calls through a
6042 -- value of such type will be local anyway in the absence of a PCS).
6044 if Comes_From_Source (N)
6045 and then Is_Remote_Access_To_Subprogram_Type (E)
6046 and then Ekind (E) = E_Access_Subprogram_Type
6047 and then Expander_Active
6048 and then Get_PCS_Name /= Name_No_DSA
6050 Rewrite (N, New_Occurrence_Of (Equivalent_Type (E), Sloc (N)));
6054 -- Set the entity. Note that the reason we call Set_Entity for the
6055 -- overloadable case, as opposed to Set_Entity_With_Checks is
6056 -- that in the overloaded case, the initial call can set the wrong
6057 -- homonym. The call that sets the right homonym is in Sem_Res and
6058 -- that call does use Set_Entity_With_Checks, so we don't miss
6061 if Is_Overloadable (E) then
6064 Set_Entity_With_Checks (N, E);
6070 Set_Etype (N, Get_Full_View (Etype (E)));
6073 if Debug_Flag_E then
6074 Write_Str (" found ");
6075 Write_Entity_Info (E, " ");
6078 -- If the Ekind of the entity is Void, it means that all homonyms
6079 -- are hidden from all visibility (RM 8.3(5,14-20)). However, this
6080 -- test is skipped if the current scope is a record and the name is
6081 -- a pragma argument expression (case of Atomic and Volatile pragmas
6082 -- and possibly other similar pragmas added later, which are allowed
6083 -- to reference components in the current record).
6085 if Ekind (E) = E_Void
6087 (not Is_Record_Type (Current_Scope)
6088 or else Nkind (Parent (N)) /= N_Pragma_Argument_Association)
6090 Premature_Usage (N);
6092 -- If the entity is overloadable, collect all interpretations of the
6093 -- name for subsequent overload resolution. We optimize a bit here to
6094 -- do this only if we have an overloadable entity that is not on its
6095 -- own on the homonym chain.
6097 elsif Is_Overloadable (E)
6098 and then (Present (Homonym (E)) or else Current_Entity (N) /= E)
6100 Collect_Interps (N);
6102 -- If no homonyms were visible, the entity is unambiguous
6104 if not Is_Overloaded (N) then
6105 if not Is_Actual_Parameter then
6106 Generate_Reference (E, N);
6110 -- Case of non-overloadable entity, set the entity providing that
6111 -- we do not have the case of a discriminant reference within a
6112 -- default expression. Such references are replaced with the
6113 -- corresponding discriminal, which is the formal corresponding to
6114 -- to the discriminant in the initialization procedure.
6117 -- Entity is unambiguous, indicate that it is referenced here
6119 -- For a renaming of an object, always generate simple reference,
6120 -- we don't try to keep track of assignments in this case, except
6121 -- in SPARK mode where renamings are traversed for generating
6122 -- local effects of subprograms.
6125 and then Present (Renamed_Object (E))
6126 and then not GNATprove_Mode
6128 Generate_Reference (E, N);
6130 -- If the renamed entity is a private protected component,
6131 -- reference the original component as well. This needs to be
6132 -- done because the private renamings are installed before any
6133 -- analysis has occurred. Reference to a private component will
6134 -- resolve to the renaming and the original component will be
6135 -- left unreferenced, hence the following.
6137 if Is_Prival (E) then
6138 Generate_Reference (Prival_Link (E), N);
6141 -- One odd case is that we do not want to set the Referenced flag
6142 -- if the entity is a label, and the identifier is the label in
6143 -- the source, since this is not a reference from the point of
6144 -- view of the user.
6146 elsif Nkind (Parent (N)) = N_Label then
6148 R : constant Boolean := Referenced (E);
6151 -- Generate reference unless this is an actual parameter
6152 -- (see comment below).
6154 if not Is_Actual_Parameter then
6155 Generate_Reference (E, N);
6156 Set_Referenced (E, R);
6160 -- Normal case, not a label: generate reference
6163 if not Is_Actual_Parameter then
6165 -- Package or generic package is always a simple reference
6167 if Is_Package_Or_Generic_Package (E) then
6168 Generate_Reference (E, N, 'r');
6170 -- Else see if we have a left hand side
6175 Generate_Reference (E, N, 'm');
6178 Generate_Reference (E, N, 'r');
6180 -- If we don't know now, generate reference later
6183 Defer_Reference ((E, N));
6189 Set_Entity_Or_Discriminal (N, E);
6191 -- The name may designate a generalized reference, in which case
6192 -- the dereference interpretation will be included. Context is
6193 -- one in which a name is legal.
6195 if Ada_Version >= Ada_2012
6197 (Nkind (Parent (N)) in N_Subexpr
6198 or else Nkind (Parent (N)) in N_Assignment_Statement
6199 | N_Object_Declaration
6200 | N_Parameter_Association)
6202 Check_Implicit_Dereference (N, Etype (E));
6207 -- Mark relevant use-type and use-package clauses as effective if the
6208 -- node in question is not overloaded and therefore does not require
6211 -- Note: Generic actual subprograms do not follow the normal resolution
6212 -- path, so ignore the fact that they are overloaded and mark them
6215 if Nkind (N) not in N_Subexpr or else not Is_Overloaded (N) then
6216 Mark_Use_Clauses (N);
6219 -- Come here with entity set
6222 Check_Restriction_No_Use_Of_Entity (N);
6224 -- Annotate the tree by creating a variable reference marker in case the
6225 -- original variable reference is folded or optimized away. The variable
6226 -- reference marker is automatically saved for later examination by the
6227 -- ABE Processing phase. Variable references which act as actuals in a
6228 -- call require special processing and are left to Resolve_Actuals. The
6229 -- reference is a write when it appears on the left hand side of an
6232 if Needs_Variable_Reference_Marker (N => N, Calls_OK => False) then
6234 Is_Assignment_LHS : constant Boolean := Is_LHS (N) = Yes;
6237 Build_Variable_Reference_Marker
6239 Read => not Is_Assignment_LHS,
6240 Write => Is_Assignment_LHS);
6243 end Find_Direct_Name;
6245 ------------------------
6246 -- Find_Expanded_Name --
6247 ------------------------
6249 -- This routine searches the homonym chain of the entity until it finds
6250 -- an entity declared in the scope denoted by the prefix. If the entity
6251 -- is private, it may nevertheless be immediately visible, if we are in
6252 -- the scope of its declaration.
6254 procedure Find_Expanded_Name (N : Node_Id) is
6255 function In_Abstract_View_Pragma (Nod : Node_Id) return Boolean;
6256 -- Determine whether expanded name Nod appears within a pragma which is
6257 -- a suitable context for an abstract view of a state or variable. The
6258 -- following pragmas fall in this category:
6265 -- In addition, pragma Abstract_State is also considered suitable even
6266 -- though it is an illegal context for an abstract view as this allows
6267 -- for proper resolution of abstract views of variables. This illegal
6268 -- context is later flagged in the analysis of indicator Part_Of.
6270 -----------------------------
6271 -- In_Abstract_View_Pragma --
6272 -----------------------------
6274 function In_Abstract_View_Pragma (Nod : Node_Id) return Boolean is
6278 -- Climb the parent chain looking for a pragma
6281 while Present (Par) loop
6282 if Nkind (Par) = N_Pragma then
6283 if Pragma_Name_Unmapped (Par)
6284 in Name_Abstract_State
6288 | Name_Refined_Depends
6289 | Name_Refined_Global
6293 -- Otherwise the pragma is not a legal context for an abstract
6300 -- Prevent the search from going too far
6302 elsif Is_Body_Or_Package_Declaration (Par) then
6306 Par := Parent (Par);
6310 end In_Abstract_View_Pragma;
6314 Selector : constant Node_Id := Selector_Name (N);
6316 Candidate : Entity_Id := Empty;
6320 -- Start of processing for Find_Expanded_Name
6323 P_Name := Entity (Prefix (N));
6325 -- If the prefix is a renamed package, look for the entity in the
6326 -- original package.
6328 if Ekind (P_Name) = E_Package
6329 and then Present (Renamed_Object (P_Name))
6331 P_Name := Renamed_Object (P_Name);
6333 if From_Limited_With (P_Name)
6334 and then not Unit_Is_Visible (Cunit (Get_Source_Unit (P_Name)))
6337 ("renaming of limited view of package & not usable in this"
6338 & " context (RM 8.5.3(3.1/2))", Prefix (N), P_Name);
6340 elsif Has_Limited_View (P_Name)
6341 and then not Unit_Is_Visible (Cunit (Get_Source_Unit (P_Name)))
6342 and then not Is_Visible_Through_Renamings (P_Name)
6345 ("renaming of limited view of package & not usable in this"
6346 & " context (RM 8.5.3(3.1/2))", Prefix (N), P_Name);
6349 -- Rewrite node with entity field pointing to renamed object
6351 Rewrite (Prefix (N), New_Copy (Prefix (N)));
6352 Set_Entity (Prefix (N), P_Name);
6354 -- If the prefix is an object of a concurrent type, look for
6355 -- the entity in the associated task or protected type.
6357 elsif Is_Concurrent_Type (Etype (P_Name)) then
6358 P_Name := Etype (P_Name);
6361 Id := Current_Entity (Selector);
6364 Is_New_Candidate : Boolean;
6367 while Present (Id) loop
6368 if Scope (Id) = P_Name then
6370 Is_New_Candidate := True;
6372 -- Handle abstract views of states and variables. These are
6373 -- acceptable candidates only when the reference to the view
6374 -- appears in certain pragmas.
6376 if Ekind (Id) = E_Abstract_State
6377 and then From_Limited_With (Id)
6378 and then Present (Non_Limited_View (Id))
6380 if In_Abstract_View_Pragma (N) then
6381 Candidate := Non_Limited_View (Id);
6382 Is_New_Candidate := True;
6384 -- Hide the candidate because it is not used in a proper
6389 Is_New_Candidate := False;
6393 -- Ada 2005 (AI-217): Handle shadow entities associated with
6394 -- types declared in limited-withed nested packages. We don't need
6395 -- to handle E_Incomplete_Subtype entities because the entities
6396 -- in the limited view are always E_Incomplete_Type and
6397 -- E_Class_Wide_Type entities (see Build_Limited_Views).
6399 -- Regarding the expression used to evaluate the scope, it
6400 -- is important to note that the limited view also has shadow
6401 -- entities associated nested packages. For this reason the
6402 -- correct scope of the entity is the scope of the real entity.
6403 -- The non-limited view may itself be incomplete, in which case
6404 -- get the full view if available.
6406 elsif Ekind (Id) in E_Incomplete_Type | E_Class_Wide_Type
6407 and then From_Limited_With (Id)
6408 and then Present (Non_Limited_View (Id))
6409 and then Scope (Non_Limited_View (Id)) = P_Name
6411 Candidate := Get_Full_View (Non_Limited_View (Id));
6412 Is_New_Candidate := True;
6414 -- Handle special case where the prefix is a renaming of a shadow
6415 -- package which is visible. Required to avoid reporting spurious
6418 elsif Ekind (P_Name) = E_Package
6419 and then From_Limited_With (P_Name)
6420 and then not From_Limited_With (Id)
6421 and then Sloc (Scope (Id)) = Sloc (P_Name)
6422 and then Unit_Is_Visible (Cunit (Get_Source_Unit (P_Name)))
6424 Candidate := Get_Full_View (Id);
6425 Is_New_Candidate := True;
6427 -- An unusual case arises with a fully qualified name for an
6428 -- entity local to a generic child unit package, within an
6429 -- instantiation of that package. The name of the unit now
6430 -- denotes the renaming created within the instance. This is
6431 -- only relevant in an instance body, see below.
6433 elsif Is_Generic_Instance (Scope (Id))
6434 and then In_Open_Scopes (Scope (Id))
6435 and then In_Instance_Body
6436 and then Ekind (Scope (Id)) = E_Package
6437 and then Ekind (Id) = E_Package
6438 and then Renamed_Entity (Id) = Scope (Id)
6439 and then Is_Immediately_Visible (P_Name)
6441 Is_New_Candidate := True;
6444 Is_New_Candidate := False;
6447 if Is_New_Candidate then
6449 -- If entity is a child unit, either it is a visible child of
6450 -- the prefix, or we are in the body of a generic prefix, as
6451 -- will happen when a child unit is instantiated in the body
6452 -- of a generic parent. This is because the instance body does
6453 -- not restore the full compilation context, given that all
6454 -- non-local references have been captured.
6456 if Is_Child_Unit (Id) or else P_Name = Standard_Standard then
6457 exit when Is_Visible_Lib_Unit (Id)
6458 or else (Is_Child_Unit (Id)
6459 and then In_Open_Scopes (Scope (Id))
6460 and then In_Instance_Body);
6462 exit when not Is_Hidden (Id);
6465 exit when Is_Immediately_Visible (Id);
6473 and then Ekind (P_Name) in E_Procedure | E_Function
6474 and then Is_Generic_Instance (P_Name)
6476 -- Expanded name denotes entity in (instance of) generic subprogram.
6477 -- The entity may be in the subprogram instance, or may denote one of
6478 -- the formals, which is declared in the enclosing wrapper package.
6480 P_Name := Scope (P_Name);
6482 Id := Current_Entity (Selector);
6483 while Present (Id) loop
6484 exit when Scope (Id) = P_Name;
6489 if No (Id) or else Chars (Id) /= Chars (Selector) then
6490 Set_Etype (N, Any_Type);
6492 -- If we are looking for an entity defined in System, try to find it
6493 -- in the child package that may have been provided as an extension
6494 -- to System. The Extend_System pragma will have supplied the name of
6495 -- the extension, which may have to be loaded.
6497 if Chars (P_Name) = Name_System
6498 and then Scope (P_Name) = Standard_Standard
6499 and then Present (System_Extend_Unit)
6500 and then Present_System_Aux (N)
6502 Set_Entity (Prefix (N), System_Aux_Id);
6503 Find_Expanded_Name (N);
6506 -- There is an implicit instance of the predefined operator in
6507 -- the given scope. The operator entity is defined in Standard.
6508 -- Has_Implicit_Operator makes the node into an Expanded_Name.
6510 elsif Nkind (Selector) = N_Operator_Symbol
6511 and then Has_Implicit_Operator (N)
6515 -- If there is no literal defined in the scope denoted by the
6516 -- prefix, the literal may belong to (a type derived from)
6517 -- Standard_Character, for which we have no explicit literals.
6519 elsif Nkind (Selector) = N_Character_Literal
6520 and then Has_Implicit_Character_Literal (N)
6525 -- If the prefix is a single concurrent object, use its name in
6526 -- the error message, rather than that of the anonymous type.
6528 if Is_Concurrent_Type (P_Name)
6529 and then Is_Internal_Name (Chars (P_Name))
6531 Error_Msg_Node_2 := Entity (Prefix (N));
6533 Error_Msg_Node_2 := P_Name;
6536 if P_Name = System_Aux_Id then
6537 P_Name := Scope (P_Name);
6538 Set_Entity (Prefix (N), P_Name);
6541 if Present (Candidate) then
6543 -- If we know that the unit is a child unit we can give a more
6544 -- accurate error message.
6546 if Is_Child_Unit (Candidate) then
6548 -- If the candidate is a private child unit and we are in
6549 -- the visible part of a public unit, specialize the error
6550 -- message. There might be a private with_clause for it,
6551 -- but it is not currently active.
6553 if Is_Private_Descendant (Candidate)
6554 and then Ekind (Current_Scope) = E_Package
6555 and then not In_Private_Part (Current_Scope)
6556 and then not Is_Private_Descendant (Current_Scope)
6559 ("private child unit& is not visible here", Selector);
6561 -- Normal case where we have a missing with for a child unit
6564 Error_Msg_Qual_Level := 99;
6565 Error_Msg_NE -- CODEFIX
6566 ("missing `WITH &;`", Selector, Candidate);
6567 Error_Msg_Qual_Level := 0;
6570 -- Here we don't know that this is a child unit
6573 Error_Msg_NE ("& is not a visible entity of&", N, Selector);
6577 -- Within the instantiation of a child unit, the prefix may
6578 -- denote the parent instance, but the selector has the name
6579 -- of the original child. That is to say, when A.B appears
6580 -- within an instantiation of generic child unit B, the scope
6581 -- stack includes an instance of A (P_Name) and an instance
6582 -- of B under some other name. We scan the scope to find this
6583 -- child instance, which is the desired entity.
6584 -- Note that the parent may itself be a child instance, if
6585 -- the reference is of the form A.B.C, in which case A.B has
6586 -- already been rewritten with the proper entity.
6588 if In_Open_Scopes (P_Name)
6589 and then Is_Generic_Instance (P_Name)
6592 Gen_Par : constant Entity_Id :=
6593 Generic_Parent (Specification
6594 (Unit_Declaration_Node (P_Name)));
6595 S : Entity_Id := Current_Scope;
6599 for J in reverse 0 .. Scope_Stack.Last loop
6600 S := Scope_Stack.Table (J).Entity;
6602 exit when S = Standard_Standard;
6604 if Ekind (S) in E_Function | E_Package | E_Procedure
6607 Generic_Parent (Specification
6608 (Unit_Declaration_Node (S)));
6610 -- Check that P is a generic child of the generic
6611 -- parent of the prefix.
6614 and then Chars (P) = Chars (Selector)
6615 and then Scope (P) = Gen_Par
6626 -- If this is a selection from Ada, System or Interfaces, then
6627 -- we assume a missing with for the corresponding package.
6629 if Is_Known_Unit (N)
6630 and then not (Present (Entity (Prefix (N)))
6631 and then Scope (Entity (Prefix (N))) /=
6634 if not Error_Posted (N) then
6635 Error_Msg_Node_2 := Selector;
6636 Error_Msg_N -- CODEFIX
6637 ("missing `WITH &.&;`", Prefix (N));
6640 -- If this is a selection from a dummy package, then suppress
6641 -- the error message, of course the entity is missing if the
6642 -- package is missing.
6644 elsif Sloc (Error_Msg_Node_2) = No_Location then
6647 -- Here we have the case of an undefined component
6650 -- The prefix may hide a homonym in the context that
6651 -- declares the desired entity. This error can use a
6652 -- specialized message.
6654 if In_Open_Scopes (P_Name) then
6656 H : constant Entity_Id := Homonym (P_Name);
6660 and then Is_Compilation_Unit (H)
6662 (Is_Immediately_Visible (H)
6663 or else Is_Visible_Lib_Unit (H))
6665 Id := First_Entity (H);
6666 while Present (Id) loop
6667 if Chars (Id) = Chars (Selector) then
6668 Error_Msg_Qual_Level := 99;
6669 Error_Msg_Name_1 := Chars (Selector);
6671 ("% not declared in&", N, P_Name);
6673 ("\use fully qualified name starting with "
6674 & "Standard to make& visible", N, H);
6675 Error_Msg_Qual_Level := 0;
6683 -- If not found, standard error message
6685 Error_Msg_NE ("& not declared in&", N, Selector);
6691 -- Might be worth specializing the case when the prefix
6692 -- is a limited view.
6693 -- ... not declared in limited view of...
6695 Error_Msg_NE ("& not declared in&", N, Selector);
6698 -- Check for misspelling of some entity in prefix
6700 Id := First_Entity (P_Name);
6701 while Present (Id) loop
6702 if Is_Bad_Spelling_Of (Chars (Id), Chars (Selector))
6703 and then not Is_Internal_Name (Chars (Id))
6705 Error_Msg_NE -- CODEFIX
6706 ("possible misspelling of&", Selector, Id);
6713 -- Specialize the message if this may be an instantiation
6714 -- of a child unit that was not mentioned in the context.
6716 if Nkind (Parent (N)) = N_Package_Instantiation
6717 and then Is_Generic_Instance (Entity (Prefix (N)))
6718 and then Is_Compilation_Unit
6719 (Generic_Parent (Parent (Entity (Prefix (N)))))
6721 Error_Msg_Node_2 := Selector;
6722 Error_Msg_N -- CODEFIX
6723 ("\missing `WITH &.&;`", Prefix (N));
6733 if Comes_From_Source (N)
6734 and then Is_Remote_Access_To_Subprogram_Type (Id)
6735 and then Ekind (Id) = E_Access_Subprogram_Type
6736 and then Present (Equivalent_Type (Id))
6738 -- If we are not actually generating distribution code (i.e. the
6739 -- current PCS is the dummy non-distributed version), then the
6740 -- Equivalent_Type will be missing, and Id should be treated as
6741 -- a regular access-to-subprogram type.
6743 Id := Equivalent_Type (Id);
6744 Set_Chars (Selector, Chars (Id));
6747 -- Ada 2005 (AI-50217): Check usage of entities in limited withed units
6749 if Ekind (P_Name) = E_Package and then From_Limited_With (P_Name) then
6750 if From_Limited_With (Id)
6751 or else Is_Type (Id)
6752 or else Ekind (Id) = E_Package
6757 ("limited withed package can only be used to access incomplete "
6762 if Is_Task_Type (P_Name)
6763 and then ((Ekind (Id) = E_Entry
6764 and then Nkind (Parent (N)) /= N_Attribute_Reference)
6766 (Ekind (Id) = E_Entry_Family
6768 Nkind (Parent (Parent (N))) /= N_Attribute_Reference))
6770 -- If both the task type and the entry are in scope, this may still
6771 -- be the expanded name of an entry formal.
6773 if In_Open_Scopes (Id)
6774 and then Nkind (Parent (N)) = N_Selected_Component
6779 -- It is an entry call after all, either to the current task
6780 -- (which will deadlock) or to an enclosing task.
6782 Analyze_Selected_Component (N);
6787 Change_Selected_Component_To_Expanded_Name (N);
6789 -- Preserve relevant elaboration-related attributes of the context which
6790 -- are no longer available or very expensive to recompute once analysis,
6791 -- resolution, and expansion are over.
6793 Mark_Elaboration_Attributes
6799 -- Set appropriate type
6801 if Is_Type (Id) then
6804 Set_Etype (N, Get_Full_View (Etype (Id)));
6807 -- Do style check and generate reference, but skip both steps if this
6808 -- entity has homonyms, since we may not have the right homonym set yet.
6809 -- The proper homonym will be set during the resolve phase.
6811 if Has_Homonym (Id) then
6815 Set_Entity_Or_Discriminal (N, Id);
6819 Generate_Reference (Id, N, 'm');
6822 Generate_Reference (Id, N, 'r');
6825 Defer_Reference ((Id, N));
6829 -- Check for violation of No_Wide_Characters
6831 Check_Wide_Character_Restriction (Id, N);
6833 -- If the Ekind of the entity is Void, it means that all homonyms are
6834 -- hidden from all visibility (RM 8.3(5,14-20)).
6836 if Ekind (Id) = E_Void then
6837 Premature_Usage (N);
6839 elsif Is_Overloadable (Id) and then Present (Homonym (Id)) then
6841 H : Entity_Id := Homonym (Id);
6844 while Present (H) loop
6845 if Scope (H) = Scope (Id)
6846 and then (not Is_Hidden (H)
6847 or else Is_Immediately_Visible (H))
6849 Collect_Interps (N);
6856 -- If an extension of System is present, collect possible explicit
6857 -- overloadings declared in the extension.
6859 if Chars (P_Name) = Name_System
6860 and then Scope (P_Name) = Standard_Standard
6861 and then Present (System_Extend_Unit)
6862 and then Present_System_Aux (N)
6864 H := Current_Entity (Id);
6866 while Present (H) loop
6867 if Scope (H) = System_Aux_Id then
6868 Add_One_Interp (N, H, Etype (H));
6877 if Nkind (Selector_Name (N)) = N_Operator_Symbol
6878 and then Scope (Id) /= Standard_Standard
6880 -- In addition to user-defined operators in the given scope, there
6881 -- may be an implicit instance of the predefined operator. The
6882 -- operator (defined in Standard) is found in Has_Implicit_Operator,
6883 -- and added to the interpretations. Procedure Add_One_Interp will
6884 -- determine which hides which.
6886 if Has_Implicit_Operator (N) then
6891 -- If there is a single interpretation for N we can generate a
6892 -- reference to the unique entity found.
6894 if Is_Overloadable (Id) and then not Is_Overloaded (N) then
6895 Generate_Reference (Id, N);
6898 -- Mark relevant use-type and use-package clauses as effective if the
6899 -- node in question is not overloaded and therefore does not require
6902 if Nkind (N) not in N_Subexpr or else not Is_Overloaded (N) then
6903 Mark_Use_Clauses (N);
6906 Check_Restriction_No_Use_Of_Entity (N);
6908 -- Annotate the tree by creating a variable reference marker in case the
6909 -- original variable reference is folded or optimized away. The variable
6910 -- reference marker is automatically saved for later examination by the
6911 -- ABE Processing phase. Variable references which act as actuals in a
6912 -- call require special processing and are left to Resolve_Actuals. The
6913 -- reference is a write when it appears on the left hand side of an
6916 if Needs_Variable_Reference_Marker
6921 Is_Assignment_LHS : constant Boolean := Is_LHS (N) = Yes;
6924 Build_Variable_Reference_Marker
6926 Read => not Is_Assignment_LHS,
6927 Write => Is_Assignment_LHS);
6930 end Find_Expanded_Name;
6932 --------------------
6933 -- Find_Most_Prev --
6934 --------------------
6936 function Find_Most_Prev (Use_Clause : Node_Id) return Node_Id is
6940 -- Loop through the Prev_Use_Clause chain
6943 while Present (Prev_Use_Clause (Curr)) loop
6944 Curr := Prev_Use_Clause (Curr);
6950 -------------------------
6951 -- Find_Renamed_Entity --
6952 -------------------------
6954 function Find_Renamed_Entity
6958 Is_Actual : Boolean := False) return Entity_Id
6961 I1 : Interp_Index := 0; -- Suppress junk warnings
6967 function Find_Nearer_Entity
6970 Old2_S : Entity_Id) return Entity_Id;
6971 -- Determine whether one of Old_S1 and Old_S2 is nearer to New_S than
6972 -- the other, and return it if so. Return Empty otherwise. We use this
6973 -- in conjunction with Inherit_Renamed_Profile to simplify later type
6974 -- disambiguation for actual subprograms in instances.
6976 function Is_Visible_Operation (Op : Entity_Id) return Boolean;
6977 -- If the renamed entity is an implicit operator, check whether it is
6978 -- visible because its operand type is properly visible. This check
6979 -- applies to explicit renamed entities that appear in the source in a
6980 -- renaming declaration or a formal subprogram instance, but not to
6981 -- default generic actuals with a name.
6983 function Report_Overload return Entity_Id;
6984 -- List possible interpretations, and specialize message in the
6985 -- case of a generic actual.
6987 function Within (Inner, Outer : Entity_Id) return Boolean;
6988 -- Determine whether a candidate subprogram is defined within the
6989 -- enclosing instance. If yes, it has precedence over outer candidates.
6991 --------------------------
6992 -- Find_Nearer_Entity --
6993 --------------------------
6995 function Find_Nearer_Entity
6998 Old2_S : Entity_Id) return Entity_Id
7006 New_F := First_Formal (New_S);
7007 Old1_F := First_Formal (Old1_S);
7008 Old2_F := First_Formal (Old2_S);
7010 -- The criterion is whether the type of the formals of one of Old1_S
7011 -- and Old2_S is an ancestor subtype of the type of the corresponding
7012 -- formals of New_S while the other is not (we already know that they
7013 -- are all subtypes of the same base type).
7015 -- This makes it possible to find the more correct renamed entity in
7016 -- the case of a generic instantiation nested in an enclosing one for
7017 -- which different formal types get the same actual type, which will
7018 -- in turn make it possible for Inherit_Renamed_Profile to preserve
7019 -- types on formal parameters and ultimately simplify disambiguation.
7021 -- Consider the follow package G:
7024 -- type Item_T is private;
7025 -- with function Compare (L, R: Item_T) return Boolean is <>;
7027 -- type Bound_T is private;
7028 -- with function Compare (L, R : Bound_T) return Boolean is <>;
7033 -- package body G is
7034 -- package My_Inner is Inner_G (Bound_T);
7038 -- with the following package Inner_G:
7041 -- type T is private;
7042 -- with function Compare (L, R: T) return Boolean is <>;
7043 -- package Inner_G is
7044 -- function "<" (L, R: T) return Boolean is (Compare (L, R));
7047 -- If G is instantiated on the same actual type with a single Compare
7051 -- function Compare (L, R : T) return Boolean;
7052 -- package My_G is new (T, T);
7054 -- then the renaming generated for Compare in the inner instantiation
7055 -- is ambiguous: it can rename either of the renamings generated for
7056 -- the outer instantiation. Now if the first one is picked up, then
7057 -- the subtypes of the formal parameters of the renaming will not be
7058 -- preserved in Inherit_Renamed_Profile because they are subtypes of
7059 -- the Bound_T formal type and not of the Item_T formal type, so we
7060 -- need to arrange for the second one to be picked up instead.
7062 while Present (New_F) loop
7063 if Etype (Old1_F) /= Etype (Old2_F) then
7064 Anc_T := Ancestor_Subtype (Etype (New_F));
7066 if Etype (Old1_F) = Anc_T then
7068 elsif Etype (Old2_F) = Anc_T then
7073 Next_Formal (New_F);
7074 Next_Formal (Old1_F);
7075 Next_Formal (Old2_F);
7078 pragma Assert (No (Old1_F));
7079 pragma Assert (No (Old2_F));
7082 end Find_Nearer_Entity;
7084 --------------------------
7085 -- Is_Visible_Operation --
7086 --------------------------
7088 function Is_Visible_Operation (Op : Entity_Id) return Boolean is
7094 if Ekind (Op) /= E_Operator
7095 or else Scope (Op) /= Standard_Standard
7096 or else (In_Instance
7097 and then (not Is_Actual
7098 or else Present (Enclosing_Instance)))
7103 -- For a fixed point type operator, check the resulting type,
7104 -- because it may be a mixed mode integer * fixed operation.
7106 if Present (Next_Formal (First_Formal (New_S)))
7107 and then Is_Fixed_Point_Type (Etype (New_S))
7109 Typ := Etype (New_S);
7111 Typ := Etype (First_Formal (New_S));
7114 Btyp := Base_Type (Typ);
7116 if Nkind (Nam) /= N_Expanded_Name then
7117 return (In_Open_Scopes (Scope (Btyp))
7118 or else Is_Potentially_Use_Visible (Btyp)
7119 or else In_Use (Btyp)
7120 or else In_Use (Scope (Btyp)));
7123 Scop := Entity (Prefix (Nam));
7125 if Ekind (Scop) = E_Package
7126 and then Present (Renamed_Object (Scop))
7128 Scop := Renamed_Object (Scop);
7131 -- Operator is visible if prefix of expanded name denotes
7132 -- scope of type, or else type is defined in System_Aux
7133 -- and the prefix denotes System.
7135 return Scope (Btyp) = Scop
7136 or else (Scope (Btyp) = System_Aux_Id
7137 and then Scope (Scope (Btyp)) = Scop);
7140 end Is_Visible_Operation;
7146 function Within (Inner, Outer : Entity_Id) return Boolean is
7150 Sc := Scope (Inner);
7151 while Sc /= Standard_Standard loop
7162 ---------------------
7163 -- Report_Overload --
7164 ---------------------
7166 function Report_Overload return Entity_Id is
7169 Error_Msg_NE -- CODEFIX
7170 ("ambiguous actual subprogram&, " &
7171 "possible interpretations:", N, Nam);
7173 Error_Msg_N -- CODEFIX
7174 ("ambiguous subprogram, " &
7175 "possible interpretations:", N);
7178 List_Interps (Nam, N);
7180 end Report_Overload;
7182 -- Start of processing for Find_Renamed_Entity
7186 Candidate_Renaming := Empty;
7188 if Is_Overloaded (Nam) then
7189 Get_First_Interp (Nam, Ind, It);
7190 while Present (It.Nam) loop
7191 if Entity_Matches_Spec (It.Nam, New_S)
7192 and then Is_Visible_Operation (It.Nam)
7194 if Old_S /= Any_Id then
7196 -- Note: The call to Disambiguate only happens if a
7197 -- previous interpretation was found, in which case I1
7198 -- has received a value.
7200 It1 := Disambiguate (Nam, I1, Ind, Etype (Old_S));
7202 if It1 = No_Interp then
7203 Inst := Enclosing_Instance;
7205 if Present (Inst) then
7206 if Within (It.Nam, Inst) then
7207 if Within (Old_S, Inst) then
7209 It_D : constant Uint := Scope_Depth (It.Nam);
7210 Old_D : constant Uint := Scope_Depth (Old_S);
7213 -- Choose the innermost subprogram, which
7214 -- would hide the outer one in the generic.
7216 if Old_D > It_D then
7218 elsif It_D > Old_D then
7222 -- Otherwise, if we can determine that one
7223 -- of the entities is nearer to the renaming
7224 -- than the other, choose it. If not, then
7225 -- return the newer one as done historically.
7228 Find_Nearer_Entity (New_S, Old_S, It.Nam);
7229 if Present (N_Ent) then
7237 elsif Within (Old_S, Inst) then
7241 return Report_Overload;
7244 -- If not within an instance, ambiguity is real
7247 return Report_Overload;
7261 Present (First_Formal (It.Nam))
7262 and then Present (First_Formal (New_S))
7263 and then (Base_Type (Etype (First_Formal (It.Nam))) =
7264 Base_Type (Etype (First_Formal (New_S))))
7266 Candidate_Renaming := It.Nam;
7269 Get_Next_Interp (Ind, It);
7272 Set_Entity (Nam, Old_S);
7274 if Old_S /= Any_Id then
7275 Set_Is_Overloaded (Nam, False);
7278 -- Non-overloaded case
7282 and then Present (Enclosing_Instance)
7283 and then Entity_Matches_Spec (Entity (Nam), New_S)
7285 Old_S := Entity (Nam);
7287 elsif Entity_Matches_Spec (Entity (Nam), New_S) then
7288 Candidate_Renaming := New_S;
7290 if Is_Visible_Operation (Entity (Nam)) then
7291 Old_S := Entity (Nam);
7294 elsif Present (First_Formal (Entity (Nam)))
7295 and then Present (First_Formal (New_S))
7296 and then (Base_Type (Etype (First_Formal (Entity (Nam)))) =
7297 Base_Type (Etype (First_Formal (New_S))))
7299 Candidate_Renaming := Entity (Nam);
7304 end Find_Renamed_Entity;
7306 -----------------------------
7307 -- Find_Selected_Component --
7308 -----------------------------
7310 procedure Find_Selected_Component (N : Node_Id) is
7311 P : constant Node_Id := Prefix (N);
7314 -- Entity denoted by prefix
7321 function Available_Subtype return Boolean;
7322 -- A small optimization: if the prefix is constrained and the component
7323 -- is an array type we may already have a usable subtype for it, so we
7324 -- can use it rather than generating a new one, because the bounds
7325 -- will be the values of the discriminants and not discriminant refs.
7326 -- This simplifies value tracing in GNATprove. For consistency, both
7327 -- the entity name and the subtype come from the constrained component.
7329 -- This is only used in GNATprove mode: when generating code it may be
7330 -- necessary to create an itype in the scope of use of the selected
7331 -- component, e.g. in the context of a expanded record equality.
7333 function Is_Reference_In_Subunit return Boolean;
7334 -- In a subunit, the scope depth is not a proper measure of hiding,
7335 -- because the context of the proper body may itself hide entities in
7336 -- parent units. This rare case requires inspecting the tree directly
7337 -- because the proper body is inserted in the main unit and its context
7338 -- is simply added to that of the parent.
7340 -----------------------
7341 -- Available_Subtype --
7342 -----------------------
7344 function Available_Subtype return Boolean is
7348 if GNATprove_Mode then
7349 Comp := First_Entity (Etype (P));
7350 while Present (Comp) loop
7351 if Chars (Comp) = Chars (Selector_Name (N)) then
7352 Set_Etype (N, Etype (Comp));
7353 Set_Entity (Selector_Name (N), Comp);
7354 Set_Etype (Selector_Name (N), Etype (Comp));
7358 Next_Component (Comp);
7363 end Available_Subtype;
7365 -----------------------------
7366 -- Is_Reference_In_Subunit --
7367 -----------------------------
7369 function Is_Reference_In_Subunit return Boolean is
7371 Comp_Unit : Node_Id;
7375 while Present (Comp_Unit)
7376 and then Nkind (Comp_Unit) /= N_Compilation_Unit
7378 Comp_Unit := Parent (Comp_Unit);
7381 if No (Comp_Unit) or else Nkind (Unit (Comp_Unit)) /= N_Subunit then
7385 -- Now check whether the package is in the context of the subunit
7387 Clause := First (Context_Items (Comp_Unit));
7388 while Present (Clause) loop
7389 if Nkind (Clause) = N_With_Clause
7390 and then Entity (Name (Clause)) = P_Name
7399 end Is_Reference_In_Subunit;
7401 -- Start of processing for Find_Selected_Component
7406 if Nkind (P) = N_Error then
7410 -- If the selector already has an entity, the node has been constructed
7411 -- in the course of expansion, and is known to be valid. Do not verify
7412 -- that it is defined for the type (it may be a private component used
7413 -- in the expansion of record equality).
7415 if Present (Entity (Selector_Name (N))) then
7416 if No (Etype (N)) or else Etype (N) = Any_Type then
7418 Sel_Name : constant Node_Id := Selector_Name (N);
7419 Selector : constant Entity_Id := Entity (Sel_Name);
7423 Set_Etype (Sel_Name, Etype (Selector));
7425 if not Is_Entity_Name (P) then
7429 -- Build an actual subtype except for the first parameter
7430 -- of an init proc, where this actual subtype is by
7431 -- definition incorrect, since the object is uninitialized
7432 -- (and does not even have defined discriminants etc.)
7434 if Is_Entity_Name (P)
7435 and then Ekind (Entity (P)) = E_Function
7437 Nam := New_Copy (P);
7439 if Is_Overloaded (P) then
7440 Save_Interps (P, Nam);
7443 Rewrite (P, Make_Function_Call (Sloc (P), Name => Nam));
7445 Analyze_Selected_Component (N);
7448 elsif Ekind (Selector) = E_Component
7449 and then (not Is_Entity_Name (P)
7450 or else Chars (Entity (P)) /= Name_uInit)
7452 -- Check if we already have an available subtype we can use
7454 if Ekind (Etype (P)) = E_Record_Subtype
7455 and then Nkind (Parent (Etype (P))) = N_Subtype_Declaration
7456 and then Is_Array_Type (Etype (Selector))
7457 and then not Is_Packed (Etype (Selector))
7458 and then Available_Subtype
7462 -- Do not build the subtype when referencing components of
7463 -- dispatch table wrappers. Required to avoid generating
7464 -- elaboration code with HI runtimes.
7466 elsif RTU_Loaded (Ada_Tags)
7468 ((RTE_Available (RE_Dispatch_Table_Wrapper)
7469 and then Scope (Selector) =
7470 RTE (RE_Dispatch_Table_Wrapper))
7472 (RTE_Available (RE_No_Dispatch_Table_Wrapper)
7473 and then Scope (Selector) =
7474 RTE (RE_No_Dispatch_Table_Wrapper)))
7479 Build_Actual_Subtype_Of_Component
7480 (Etype (Selector), N);
7487 if No (C_Etype) then
7488 C_Etype := Etype (Selector);
7490 Insert_Action (N, C_Etype);
7491 C_Etype := Defining_Identifier (C_Etype);
7494 Set_Etype (N, C_Etype);
7497 -- If the selected component appears within a default expression
7498 -- and it has an actual subtype, the preanalysis has not yet
7499 -- completed its analysis, because Insert_Actions is disabled in
7500 -- that context. Within the init proc of the enclosing type we
7501 -- must complete this analysis, if an actual subtype was created.
7503 elsif Inside_Init_Proc then
7505 Typ : constant Entity_Id := Etype (N);
7506 Decl : constant Node_Id := Declaration_Node (Typ);
7508 if Nkind (Decl) = N_Subtype_Declaration
7509 and then not Analyzed (Decl)
7510 and then Is_List_Member (Decl)
7511 and then No (Parent (Decl))
7514 Insert_Action (N, Decl);
7521 elsif Is_Entity_Name (P) then
7522 P_Name := Entity (P);
7524 -- The prefix may denote an enclosing type which is the completion
7525 -- of an incomplete type declaration.
7527 if Is_Type (P_Name) then
7528 Set_Entity (P, Get_Full_View (P_Name));
7529 Set_Etype (P, Entity (P));
7530 P_Name := Entity (P);
7533 P_Type := Base_Type (Etype (P));
7535 if Debug_Flag_E then
7536 Write_Str ("Found prefix type to be ");
7537 Write_Entity_Info (P_Type, " "); Write_Eol;
7540 -- If the prefix's type is an access type, get to the record type
7542 if Is_Access_Type (P_Type) then
7543 P_Type := Implicitly_Designated_Type (P_Type);
7546 -- First check for components of a record object (not the
7547 -- result of a call, which is handled below).
7549 if Has_Components (P_Type)
7550 and then not Is_Overloadable (P_Name)
7551 and then not Is_Type (P_Name)
7553 -- Selected component of record. Type checking will validate
7554 -- name of selector.
7556 -- ??? Could we rewrite an implicit dereference into an explicit
7559 Analyze_Selected_Component (N);
7561 -- Reference to type name in predicate/invariant expression
7563 elsif Is_Concurrent_Type (P_Type)
7564 and then not In_Open_Scopes (P_Name)
7565 and then (not Is_Concurrent_Type (Etype (P_Name))
7566 or else not In_Open_Scopes (Etype (P_Name)))
7568 -- Call to protected operation or entry. Type checking is
7569 -- needed on the prefix.
7571 Analyze_Selected_Component (N);
7573 elsif (In_Open_Scopes (P_Name)
7574 and then Ekind (P_Name) /= E_Void
7575 and then not Is_Overloadable (P_Name))
7576 or else (Is_Concurrent_Type (Etype (P_Name))
7577 and then In_Open_Scopes (Etype (P_Name)))
7579 -- Prefix denotes an enclosing loop, block, or task, i.e. an
7580 -- enclosing construct that is not a subprogram or accept.
7582 -- A special case: a protected body may call an operation
7583 -- on an external object of the same type, in which case it
7584 -- is not an expanded name. If the prefix is the type itself,
7585 -- or the context is a single synchronized object it can only
7586 -- be interpreted as an expanded name.
7588 if Is_Concurrent_Type (Etype (P_Name)) then
7590 or else Present (Anonymous_Object (Etype (P_Name)))
7592 Find_Expanded_Name (N);
7595 Analyze_Selected_Component (N);
7600 Find_Expanded_Name (N);
7603 elsif Ekind (P_Name) = E_Package then
7604 Find_Expanded_Name (N);
7606 elsif Is_Overloadable (P_Name) then
7608 -- The subprogram may be a renaming (of an enclosing scope) as
7609 -- in the case of the name of the generic within an instantiation.
7611 if Ekind (P_Name) in E_Procedure | E_Function
7612 and then Present (Alias (P_Name))
7613 and then Is_Generic_Instance (Alias (P_Name))
7615 P_Name := Alias (P_Name);
7618 if Is_Overloaded (P) then
7620 -- The prefix must resolve to a unique enclosing construct
7623 Found : Boolean := False;
7628 Get_First_Interp (P, Ind, It);
7629 while Present (It.Nam) loop
7630 if In_Open_Scopes (It.Nam) then
7633 "prefix must be unique enclosing scope", N);
7634 Set_Entity (N, Any_Id);
7635 Set_Etype (N, Any_Type);
7644 Get_Next_Interp (Ind, It);
7649 if In_Open_Scopes (P_Name) then
7650 Set_Entity (P, P_Name);
7651 Set_Is_Overloaded (P, False);
7652 Find_Expanded_Name (N);
7655 -- If no interpretation as an expanded name is possible, it
7656 -- must be a selected component of a record returned by a
7657 -- function call. Reformat prefix as a function call, the rest
7658 -- is done by type resolution.
7660 -- Error if the prefix is procedure or entry, as is P.X
7662 if Ekind (P_Name) /= E_Function
7664 (not Is_Overloaded (P)
7665 or else Nkind (Parent (N)) = N_Procedure_Call_Statement)
7667 -- Prefix may mention a package that is hidden by a local
7668 -- declaration: let the user know. Scan the full homonym
7669 -- chain, the candidate package may be anywhere on it.
7671 if Present (Homonym (Current_Entity (P_Name))) then
7672 P_Name := Current_Entity (P_Name);
7674 while Present (P_Name) loop
7675 exit when Ekind (P_Name) = E_Package;
7676 P_Name := Homonym (P_Name);
7679 if Present (P_Name) then
7680 if not Is_Reference_In_Subunit then
7681 Error_Msg_Sloc := Sloc (Entity (Prefix (N)));
7683 ("package& is hidden by declaration#", N, P_Name);
7686 Set_Entity (Prefix (N), P_Name);
7687 Find_Expanded_Name (N);
7691 P_Name := Entity (Prefix (N));
7696 ("invalid prefix in selected component&", N, P_Name);
7697 Change_Selected_Component_To_Expanded_Name (N);
7698 Set_Entity (N, Any_Id);
7699 Set_Etype (N, Any_Type);
7701 -- Here we have a function call, so do the reformatting
7704 Nam := New_Copy (P);
7705 Save_Interps (P, Nam);
7707 -- We use Replace here because this is one of those cases
7708 -- where the parser has missclassified the node, and we fix
7709 -- things up and then do the semantic analysis on the fixed
7710 -- up node. Normally we do this using one of the Sinfo.CN
7711 -- routines, but this is too tricky for that.
7713 -- Note that using Rewrite would be wrong, because we would
7714 -- have a tree where the original node is unanalyzed.
7717 Make_Function_Call (Sloc (P), Name => Nam));
7719 -- Now analyze the reformatted node
7723 -- If the prefix is illegal after this transformation, there
7724 -- may be visibility errors on the prefix. The safest is to
7725 -- treat the selected component as an error.
7727 if Error_Posted (P) then
7728 Set_Etype (N, Any_Type);
7732 Analyze_Selected_Component (N);
7737 -- Remaining cases generate various error messages
7740 -- Format node as expanded name, to avoid cascaded errors
7742 Change_Selected_Component_To_Expanded_Name (N);
7743 Set_Entity (N, Any_Id);
7744 Set_Etype (N, Any_Type);
7746 -- Issue error message, but avoid this if error issued already.
7747 -- Use identifier of prefix if one is available.
7749 if P_Name = Any_Id then
7752 -- It is not an error if the prefix is the current instance of
7753 -- type name, e.g. the expression of a type aspect, when it is
7754 -- analyzed within a generic unit. We still have to verify that a
7755 -- component of that name exists, and decorate the node
7758 elsif Is_Entity_Name (P) and then Is_Current_Instance (P) then
7763 Comp := First_Entity (Entity (P));
7764 while Present (Comp) loop
7765 if Chars (Comp) = Chars (Selector_Name (N)) then
7766 Set_Entity (N, Comp);
7767 Set_Etype (N, Etype (Comp));
7768 Set_Entity (Selector_Name (N), Comp);
7769 Set_Etype (Selector_Name (N), Etype (Comp));
7777 elsif Ekind (P_Name) = E_Void then
7778 Premature_Usage (P);
7780 elsif Nkind (P) /= N_Attribute_Reference then
7782 -- This may have been meant as a prefixed call to a primitive
7783 -- of an untagged type. If it is a function call check type of
7784 -- its first formal and add explanation.
7787 F : constant Entity_Id :=
7788 Current_Entity (Selector_Name (N));
7791 and then Is_Overloadable (F)
7792 and then Present (First_Entity (F))
7793 and then not Is_Tagged_Type (Etype (First_Entity (F)))
7796 ("prefixed call is only allowed for objects of a "
7797 & "tagged type", N);
7801 Error_Msg_N ("invalid prefix in selected component&", P);
7803 if Is_Incomplete_Type (P_Type)
7804 and then Is_Access_Type (Etype (P))
7807 ("\dereference must not be of an incomplete type "
7808 & "(RM 3.10.1)", P);
7812 Error_Msg_N ("invalid prefix in selected component", P);
7816 -- If prefix is not the name of an entity, it must be an expression,
7817 -- whose type is appropriate for a record. This is determined by
7820 Analyze_Selected_Component (N);
7823 Analyze_Dimension (N);
7824 end Find_Selected_Component;
7830 procedure Find_Type (N : Node_Id) is
7840 elsif Nkind (N) = N_Attribute_Reference then
7842 -- Class attribute. This is not valid in Ada 83 mode, but we do not
7843 -- need to enforce that at this point, since the declaration of the
7844 -- tagged type in the prefix would have been flagged already.
7846 if Attribute_Name (N) = Name_Class then
7847 Check_Restriction (No_Dispatch, N);
7848 Find_Type (Prefix (N));
7850 -- Propagate error from bad prefix
7852 if Etype (Prefix (N)) = Any_Type then
7853 Set_Entity (N, Any_Type);
7854 Set_Etype (N, Any_Type);
7858 T := Base_Type (Entity (Prefix (N)));
7860 -- Case where type is not known to be tagged. Its appearance in
7861 -- the prefix of the 'Class attribute indicates that the full view
7864 if not Is_Tagged_Type (T) then
7865 if Ekind (T) = E_Incomplete_Type then
7867 -- It is legal to denote the class type of an incomplete
7868 -- type. The full type will have to be tagged, of course.
7869 -- In Ada 2005 this usage is declared obsolescent, so we
7870 -- warn accordingly. This usage is only legal if the type
7871 -- is completed in the current scope, and not for a limited
7874 if Ada_Version >= Ada_2005 then
7876 -- Test whether the Available_View of a limited type view
7877 -- is tagged, since the limited view may not be marked as
7878 -- tagged if the type itself has an untagged incomplete
7879 -- type view in its package.
7881 if From_Limited_With (T)
7882 and then not Is_Tagged_Type (Available_View (T))
7885 ("prefix of Class attribute must be tagged", N);
7886 Set_Etype (N, Any_Type);
7887 Set_Entity (N, Any_Type);
7890 -- ??? This test is temporarily disabled (always
7891 -- False) because it causes an unwanted warning on
7892 -- GNAT sources (built with -gnatg, which includes
7893 -- Warn_On_Obsolescent_ Feature). Once this issue
7894 -- is cleared in the sources, it can be enabled.
7896 elsif Warn_On_Obsolescent_Feature and then False then
7898 ("applying ''Class to an untagged incomplete type"
7899 & " is an obsolescent feature (RM J.11)?r?", N);
7903 Set_Is_Tagged_Type (T);
7904 Set_Direct_Primitive_Operations (T, New_Elmt_List);
7905 Make_Class_Wide_Type (T);
7906 Set_Entity (N, Class_Wide_Type (T));
7907 Set_Etype (N, Class_Wide_Type (T));
7909 elsif Ekind (T) = E_Private_Type
7910 and then not Is_Generic_Type (T)
7911 and then In_Private_Part (Scope (T))
7913 -- The Class attribute can be applied to an untagged private
7914 -- type fulfilled by a tagged type prior to the full type
7915 -- declaration (but only within the parent package's private
7916 -- part). Create the class-wide type now and check that the
7917 -- full type is tagged later during its analysis. Note that
7918 -- we do not mark the private type as tagged, unlike the
7919 -- case of incomplete types, because the type must still
7920 -- appear untagged to outside units.
7922 if No (Class_Wide_Type (T)) then
7923 Make_Class_Wide_Type (T);
7926 Set_Entity (N, Class_Wide_Type (T));
7927 Set_Etype (N, Class_Wide_Type (T));
7930 -- Should we introduce a type Any_Tagged and use Wrong_Type
7931 -- here, it would be a bit more consistent???
7934 ("tagged type required, found}",
7935 Prefix (N), First_Subtype (T));
7936 Set_Entity (N, Any_Type);
7940 -- Case of tagged type
7943 if Is_Concurrent_Type (T) then
7944 if No (Corresponding_Record_Type (Entity (Prefix (N)))) then
7946 -- Previous error. Create a class-wide type for the
7947 -- synchronized type itself, with minimal semantic
7948 -- attributes, to catch other errors in some ACATS tests.
7950 pragma Assert (Serious_Errors_Detected /= 0);
7951 Make_Class_Wide_Type (T);
7952 C := Class_Wide_Type (T);
7953 Set_First_Entity (C, First_Entity (T));
7956 C := Class_Wide_Type
7957 (Corresponding_Record_Type (Entity (Prefix (N))));
7961 C := Class_Wide_Type (Entity (Prefix (N)));
7964 Set_Entity_With_Checks (N, C);
7965 Generate_Reference (C, N);
7969 -- Base attribute, not allowed in Ada 83
7971 elsif Attribute_Name (N) = Name_Base then
7972 if Ada_Version = Ada_83 and then Comes_From_Source (N) then
7974 ("(Ada 83) Base attribute not allowed in subtype mark", N);
7977 Find_Type (Prefix (N));
7978 Typ := Entity (Prefix (N));
7980 if Ada_Version >= Ada_95
7981 and then not Is_Scalar_Type (Typ)
7982 and then not Is_Generic_Type (Typ)
7985 ("prefix of Base attribute must be scalar type",
7988 elsif Warn_On_Redundant_Constructs
7989 and then Base_Type (Typ) = Typ
7991 Error_Msg_NE -- CODEFIX
7992 ("redundant attribute, & is its own base type?r?", N, Typ);
7995 T := Base_Type (Typ);
7997 -- Rewrite attribute reference with type itself (see similar
7998 -- processing in Analyze_Attribute, case Base). Preserve prefix
7999 -- if present, for other legality checks.
8001 if Nkind (Prefix (N)) = N_Expanded_Name then
8003 Make_Expanded_Name (Sloc (N),
8005 Prefix => New_Copy (Prefix (Prefix (N))),
8006 Selector_Name => New_Occurrence_Of (T, Sloc (N))));
8009 Rewrite (N, New_Occurrence_Of (T, Sloc (N)));
8016 elsif Attribute_Name (N) = Name_Stub_Type then
8018 -- This is handled in Analyze_Attribute
8022 -- All other attributes are invalid in a subtype mark
8025 Error_Msg_N ("invalid attribute in subtype mark", N);
8031 if Is_Entity_Name (N) then
8032 T_Name := Entity (N);
8034 Error_Msg_N ("subtype mark required in this context", N);
8035 Set_Etype (N, Any_Type);
8039 if T_Name = Any_Id or else Etype (N) = Any_Type then
8041 -- Undefined id. Make it into a valid type
8043 Set_Entity (N, Any_Type);
8045 elsif not Is_Type (T_Name)
8046 and then T_Name /= Standard_Void_Type
8048 Error_Msg_Sloc := Sloc (T_Name);
8049 Error_Msg_N ("subtype mark required in this context", N);
8050 Error_Msg_NE ("\\found & declared#", N, T_Name);
8051 Set_Entity (N, Any_Type);
8054 -- If the type is an incomplete type created to handle
8055 -- anonymous access components of a record type, then the
8056 -- incomplete type is the visible entity and subsequent
8057 -- references will point to it. Mark the original full
8058 -- type as referenced, to prevent spurious warnings.
8060 if Is_Incomplete_Type (T_Name)
8061 and then Present (Full_View (T_Name))
8062 and then not Comes_From_Source (T_Name)
8064 Set_Referenced (Full_View (T_Name));
8067 T_Name := Get_Full_View (T_Name);
8069 -- Ada 2005 (AI-251, AI-50217): Handle interfaces visible through
8070 -- limited-with clauses
8072 if From_Limited_With (T_Name)
8073 and then Is_Incomplete_Type (T_Name)
8074 and then Present (Non_Limited_View (T_Name))
8075 and then Is_Interface (Non_Limited_View (T_Name))
8077 T_Name := Non_Limited_View (T_Name);
8080 if In_Open_Scopes (T_Name) then
8081 if Ekind (Base_Type (T_Name)) = E_Task_Type then
8083 -- In Ada 2005, a task name can be used in an access
8084 -- definition within its own body. It cannot be used
8085 -- in the discriminant part of the task declaration,
8086 -- nor anywhere else in the declaration because entries
8087 -- cannot have access parameters.
8089 if Ada_Version >= Ada_2005
8090 and then Nkind (Parent (N)) = N_Access_Definition
8092 Set_Entity (N, T_Name);
8093 Set_Etype (N, T_Name);
8095 if Has_Completion (T_Name) then
8100 ("task type cannot be used as type mark " &
8101 "within its own declaration", N);
8106 ("task type cannot be used as type mark " &
8107 "within its own spec or body", N);
8110 elsif Ekind (Base_Type (T_Name)) = E_Protected_Type then
8112 -- In Ada 2005, a protected name can be used in an access
8113 -- definition within its own body.
8115 if Ada_Version >= Ada_2005
8116 and then Nkind (Parent (N)) = N_Access_Definition
8118 Set_Entity (N, T_Name);
8119 Set_Etype (N, T_Name);
8124 ("protected type cannot be used as type mark " &
8125 "within its own spec or body", N);
8129 Error_Msg_N ("type declaration cannot refer to itself", N);
8132 Set_Etype (N, Any_Type);
8133 Set_Entity (N, Any_Type);
8134 Set_Error_Posted (T_Name);
8138 Set_Entity (N, T_Name);
8139 Set_Etype (N, T_Name);
8143 if Present (Etype (N)) and then Comes_From_Source (N) then
8144 if Is_Fixed_Point_Type (Etype (N)) then
8145 Check_Restriction (No_Fixed_Point, N);
8146 elsif Is_Floating_Point_Type (Etype (N)) then
8147 Check_Restriction (No_Floating_Point, N);
8150 -- A Ghost type must appear in a specific context
8152 if Is_Ghost_Entity (Etype (N)) then
8153 Check_Ghost_Context (Etype (N), N);
8158 --------------------
8159 -- Has_Components --
8160 --------------------
8162 function Has_Components (Typ : Entity_Id) return Boolean is
8164 return Is_Record_Type (Typ)
8165 or else (Is_Private_Type (Typ) and then Has_Discriminants (Typ))
8166 or else (Is_Task_Type (Typ) and then Has_Discriminants (Typ))
8167 or else (Is_Incomplete_Type (Typ)
8168 and then From_Limited_With (Typ)
8169 and then Is_Record_Type (Available_View (Typ)));
8172 ------------------------------------
8173 -- Has_Implicit_Character_Literal --
8174 ------------------------------------
8176 function Has_Implicit_Character_Literal (N : Node_Id) return Boolean is
8178 Found : Boolean := False;
8179 P : constant Entity_Id := Entity (Prefix (N));
8180 Priv_Id : Entity_Id := Empty;
8183 if Ekind (P) = E_Package and then not In_Open_Scopes (P) then
8184 Priv_Id := First_Private_Entity (P);
8187 if P = Standard_Standard then
8188 Change_Selected_Component_To_Expanded_Name (N);
8189 Rewrite (N, Selector_Name (N));
8191 Set_Etype (Original_Node (N), Standard_Character);
8195 Id := First_Entity (P);
8196 while Present (Id) and then Id /= Priv_Id loop
8197 if Is_Standard_Character_Type (Id) and then Is_Base_Type (Id) then
8199 -- We replace the node with the literal itself, resolve as a
8200 -- character, and set the type correctly.
8203 Change_Selected_Component_To_Expanded_Name (N);
8204 Rewrite (N, Selector_Name (N));
8207 Set_Etype (Original_Node (N), Id);
8211 -- More than one type derived from Character in given scope.
8212 -- Collect all possible interpretations.
8214 Add_One_Interp (N, Id, Id);
8222 end Has_Implicit_Character_Literal;
8224 ----------------------
8225 -- Has_Private_With --
8226 ----------------------
8228 function Has_Private_With (E : Entity_Id) return Boolean is
8229 Comp_Unit : constant Node_Id := Cunit (Current_Sem_Unit);
8233 Item := First (Context_Items (Comp_Unit));
8234 while Present (Item) loop
8235 if Nkind (Item) = N_With_Clause
8236 and then Private_Present (Item)
8237 and then Entity (Name (Item)) = E
8246 end Has_Private_With;
8248 ---------------------------
8249 -- Has_Implicit_Operator --
8250 ---------------------------
8252 function Has_Implicit_Operator (N : Node_Id) return Boolean is
8253 Op_Id : constant Name_Id := Chars (Selector_Name (N));
8254 P : constant Entity_Id := Entity (Prefix (N));
8256 Priv_Id : Entity_Id := Empty;
8258 procedure Add_Implicit_Operator
8260 Op_Type : Entity_Id := Empty);
8261 -- Add implicit interpretation to node N, using the type for which a
8262 -- predefined operator exists. If the operator yields a boolean type,
8263 -- the Operand_Type is implicitly referenced by the operator, and a
8264 -- reference to it must be generated.
8266 ---------------------------
8267 -- Add_Implicit_Operator --
8268 ---------------------------
8270 procedure Add_Implicit_Operator
8272 Op_Type : Entity_Id := Empty)
8274 Predef_Op : Entity_Id;
8277 Predef_Op := Current_Entity (Selector_Name (N));
8278 while Present (Predef_Op)
8279 and then Scope (Predef_Op) /= Standard_Standard
8281 Predef_Op := Homonym (Predef_Op);
8284 if Nkind (N) = N_Selected_Component then
8285 Change_Selected_Component_To_Expanded_Name (N);
8288 -- If the context is an unanalyzed function call, determine whether
8289 -- a binary or unary interpretation is required.
8291 if Nkind (Parent (N)) = N_Indexed_Component then
8293 Is_Binary_Call : constant Boolean :=
8295 (Next (First (Expressions (Parent (N)))));
8296 Is_Binary_Op : constant Boolean :=
8298 (Predef_Op) /= Last_Entity (Predef_Op);
8299 Predef_Op2 : constant Entity_Id := Homonym (Predef_Op);
8302 if Is_Binary_Call then
8303 if Is_Binary_Op then
8304 Add_One_Interp (N, Predef_Op, T);
8306 Add_One_Interp (N, Predef_Op2, T);
8309 if not Is_Binary_Op then
8310 Add_One_Interp (N, Predef_Op, T);
8312 -- Predef_Op2 may be empty in case of previous errors
8314 elsif Present (Predef_Op2) then
8315 Add_One_Interp (N, Predef_Op2, T);
8321 Add_One_Interp (N, Predef_Op, T);
8323 -- For operators with unary and binary interpretations, if
8324 -- context is not a call, add both
8326 if Present (Homonym (Predef_Op)) then
8327 Add_One_Interp (N, Homonym (Predef_Op), T);
8331 -- The node is a reference to a predefined operator, and
8332 -- an implicit reference to the type of its operands.
8334 if Present (Op_Type) then
8335 Generate_Operator_Reference (N, Op_Type);
8337 Generate_Operator_Reference (N, T);
8339 end Add_Implicit_Operator;
8341 -- Start of processing for Has_Implicit_Operator
8344 if Ekind (P) = E_Package and then not In_Open_Scopes (P) then
8345 Priv_Id := First_Private_Entity (P);
8348 Id := First_Entity (P);
8352 -- Boolean operators: an implicit declaration exists if the scope
8353 -- contains a declaration for a derived Boolean type, or for an
8354 -- array of Boolean type.
8361 while Id /= Priv_Id loop
8362 if Valid_Boolean_Arg (Id) and then Is_Base_Type (Id) then
8363 Add_Implicit_Operator (Id);
8370 -- Equality: look for any non-limited type (result is Boolean)
8375 while Id /= Priv_Id loop
8377 and then not Is_Limited_Type (Id)
8378 and then Is_Base_Type (Id)
8380 Add_Implicit_Operator (Standard_Boolean, Id);
8387 -- Comparison operators: scalar type, or array of scalar
8394 while Id /= Priv_Id loop
8395 if (Is_Scalar_Type (Id)
8396 or else (Is_Array_Type (Id)
8397 and then Is_Scalar_Type (Component_Type (Id))))
8398 and then Is_Base_Type (Id)
8400 Add_Implicit_Operator (Standard_Boolean, Id);
8407 -- Arithmetic operators: any numeric type
8418 while Id /= Priv_Id loop
8419 if Is_Numeric_Type (Id) and then Is_Base_Type (Id) then
8420 Add_Implicit_Operator (Id);
8427 -- Concatenation: any one-dimensional array type
8429 when Name_Op_Concat =>
8430 while Id /= Priv_Id loop
8431 if Is_Array_Type (Id)
8432 and then Number_Dimensions (Id) = 1
8433 and then Is_Base_Type (Id)
8435 Add_Implicit_Operator (Id);
8442 -- What is the others condition here? Should we be using a
8443 -- subtype of Name_Id that would restrict to operators ???
8449 -- If we fall through, then we do not have an implicit operator
8452 end Has_Implicit_Operator;
8454 -----------------------------------
8455 -- Has_Loop_In_Inner_Open_Scopes --
8456 -----------------------------------
8458 function Has_Loop_In_Inner_Open_Scopes (S : Entity_Id) return Boolean is
8460 -- Several scope stacks are maintained by Scope_Stack. The base of the
8461 -- currently active scope stack is denoted by the Is_Active_Stack_Base
8462 -- flag in the scope stack entry. Note that the scope stacks used to
8463 -- simply be delimited implicitly by the presence of Standard_Standard
8464 -- at their base, but there now are cases where this is not sufficient
8465 -- because Standard_Standard actually may appear in the middle of the
8466 -- active set of scopes.
8468 for J in reverse 0 .. Scope_Stack.Last loop
8470 -- S was reached without seing a loop scope first
8472 if Scope_Stack.Table (J).Entity = S then
8475 -- S was not yet reached, so it contains at least one inner loop
8477 elsif Ekind (Scope_Stack.Table (J).Entity) = E_Loop then
8481 -- Check Is_Active_Stack_Base to tell us when to stop, as there are
8482 -- cases where Standard_Standard appears in the middle of the active
8483 -- set of scopes. This affects the declaration and overriding of
8484 -- private inherited operations in instantiations of generic child
8487 pragma Assert (not Scope_Stack.Table (J).Is_Active_Stack_Base);
8490 raise Program_Error; -- unreachable
8491 end Has_Loop_In_Inner_Open_Scopes;
8493 --------------------
8494 -- In_Open_Scopes --
8495 --------------------
8497 function In_Open_Scopes (S : Entity_Id) return Boolean is
8499 -- Several scope stacks are maintained by Scope_Stack. The base of the
8500 -- currently active scope stack is denoted by the Is_Active_Stack_Base
8501 -- flag in the scope stack entry. Note that the scope stacks used to
8502 -- simply be delimited implicitly by the presence of Standard_Standard
8503 -- at their base, but there now are cases where this is not sufficient
8504 -- because Standard_Standard actually may appear in the middle of the
8505 -- active set of scopes.
8507 for J in reverse 0 .. Scope_Stack.Last loop
8508 if Scope_Stack.Table (J).Entity = S then
8512 -- Check Is_Active_Stack_Base to tell us when to stop, as there are
8513 -- cases where Standard_Standard appears in the middle of the active
8514 -- set of scopes. This affects the declaration and overriding of
8515 -- private inherited operations in instantiations of generic child
8518 exit when Scope_Stack.Table (J).Is_Active_Stack_Base;
8524 -----------------------------
8525 -- Inherit_Renamed_Profile --
8526 -----------------------------
8528 procedure Inherit_Renamed_Profile (New_S : Entity_Id; Old_S : Entity_Id) is
8535 if Ekind (Old_S) = E_Operator then
8536 New_F := First_Formal (New_S);
8538 while Present (New_F) loop
8539 Set_Etype (New_F, Base_Type (Etype (New_F)));
8540 Next_Formal (New_F);
8543 Set_Etype (New_S, Base_Type (Etype (New_S)));
8546 New_F := First_Formal (New_S);
8547 Old_F := First_Formal (Old_S);
8549 while Present (New_F) loop
8550 New_T := Etype (New_F);
8551 Old_T := Etype (Old_F);
8553 -- If the new type is a renaming of the old one, as is the case
8554 -- for actuals in instances, retain its name, to simplify later
8557 if Nkind (Parent (New_T)) = N_Subtype_Declaration
8558 and then Is_Entity_Name (Subtype_Indication (Parent (New_T)))
8559 and then Entity (Subtype_Indication (Parent (New_T))) = Old_T
8563 Set_Etype (New_F, Old_T);
8566 Next_Formal (New_F);
8567 Next_Formal (Old_F);
8570 pragma Assert (No (Old_F));
8572 if Ekind (Old_S) in E_Function | E_Enumeration_Literal then
8573 Set_Etype (New_S, Etype (Old_S));
8576 end Inherit_Renamed_Profile;
8582 procedure Initialize is
8587 -------------------------
8588 -- Install_Use_Clauses --
8589 -------------------------
8591 procedure Install_Use_Clauses
8593 Force_Installation : Boolean := False)
8599 while Present (U) loop
8601 -- Case of USE package
8603 if Nkind (U) = N_Use_Package_Clause then
8604 Use_One_Package (U, Name (U), True);
8609 Use_One_Type (Subtype_Mark (U), Force => Force_Installation);
8613 Next_Use_Clause (U);
8615 end Install_Use_Clauses;
8617 ----------------------
8618 -- Mark_Use_Clauses --
8619 ----------------------
8621 procedure Mark_Use_Clauses (Id : Node_Or_Entity_Id) is
8622 procedure Mark_Parameters (Call : Entity_Id);
8623 -- Perform use_type_clause marking for all parameters in a subprogram
8624 -- or operator call.
8626 procedure Mark_Use_Package (Pak : Entity_Id);
8627 -- Move up the Prev_Use_Clause chain for packages denoted by Pak -
8628 -- marking each clause in the chain as effective in the process.
8630 procedure Mark_Use_Type (E : Entity_Id);
8631 -- Similar to Do_Use_Package_Marking except we move up the
8632 -- Prev_Use_Clause chain for the type denoted by E.
8634 ---------------------
8635 -- Mark_Parameters --
8636 ---------------------
8638 procedure Mark_Parameters (Call : Entity_Id) is
8642 -- Move through all of the formals
8644 Curr := First_Formal (Call);
8645 while Present (Curr) loop
8646 Mark_Use_Type (Curr);
8651 -- Handle the return type
8653 Mark_Use_Type (Call);
8654 end Mark_Parameters;
8656 ----------------------
8657 -- Mark_Use_Package --
8658 ----------------------
8660 procedure Mark_Use_Package (Pak : Entity_Id) is
8664 -- Ignore cases where the scope of the type is not a package (e.g.
8665 -- Standard_Standard).
8667 if Ekind (Pak) /= E_Package then
8671 Curr := Current_Use_Clause (Pak);
8672 while Present (Curr)
8673 and then not Is_Effective_Use_Clause (Curr)
8675 -- We need to mark the previous use clauses as effective, but
8676 -- each use clause may in turn render other use_package_clauses
8677 -- effective. Additionally, it is possible to have a parent
8678 -- package renamed as a child of itself so we must check the
8679 -- prefix entity is not the same as the package we are marking.
8681 if Nkind (Name (Curr)) /= N_Identifier
8682 and then Present (Prefix (Name (Curr)))
8683 and then Entity (Prefix (Name (Curr))) /= Pak
8685 Mark_Use_Package (Entity (Prefix (Name (Curr))));
8687 -- It is also possible to have a child package without a prefix
8688 -- that relies on a previous use_package_clause.
8690 elsif Nkind (Name (Curr)) = N_Identifier
8691 and then Is_Child_Unit (Entity (Name (Curr)))
8693 Mark_Use_Package (Scope (Entity (Name (Curr))));
8696 -- Mark the use_package_clause as effective and move up the chain
8698 Set_Is_Effective_Use_Clause (Curr);
8700 Curr := Prev_Use_Clause (Curr);
8702 end Mark_Use_Package;
8708 procedure Mark_Use_Type (E : Entity_Id) is
8713 -- Ignore void types and unresolved string literals and primitives
8715 if Nkind (E) = N_String_Literal
8716 or else Nkind (Etype (E)) not in N_Entity
8717 or else not Is_Type (Etype (E))
8722 -- Primitives with class-wide operands might additionally render
8723 -- their base type's use_clauses effective - so do a recursive check
8726 Base := Base_Type (Etype (E));
8728 if Ekind (Base) = E_Class_Wide_Type then
8729 Mark_Use_Type (Base);
8732 -- The package containing the type or operator function being used
8733 -- may be in use as well, so mark any use_package_clauses for it as
8734 -- effective. There are also additional sanity checks performed here
8735 -- for ignoring previous errors.
8737 Mark_Use_Package (Scope (Base));
8739 if Nkind (E) in N_Op
8740 and then Present (Entity (E))
8741 and then Present (Scope (Entity (E)))
8743 Mark_Use_Package (Scope (Entity (E)));
8746 Curr := Current_Use_Clause (Base);
8747 while Present (Curr)
8748 and then not Is_Effective_Use_Clause (Curr)
8750 -- Current use_type_clause may render other use_package_clauses
8753 if Nkind (Subtype_Mark (Curr)) /= N_Identifier
8754 and then Present (Prefix (Subtype_Mark (Curr)))
8756 Mark_Use_Package (Entity (Prefix (Subtype_Mark (Curr))));
8759 -- Mark the use_type_clause as effective and move up the chain
8761 Set_Is_Effective_Use_Clause (Curr);
8763 Curr := Prev_Use_Clause (Curr);
8767 -- Start of processing for Mark_Use_Clauses
8770 -- Use clauses in and of themselves do not count as a "use" of a
8773 if Nkind (Parent (Id)) in N_Use_Package_Clause | N_Use_Type_Clause then
8779 if Nkind (Id) in N_Entity then
8781 -- Mark the entity's package
8783 if Is_Potentially_Use_Visible (Id) then
8784 Mark_Use_Package (Scope (Id));
8787 -- Mark enumeration literals
8789 if Ekind (Id) = E_Enumeration_Literal then
8794 elsif (Is_Overloadable (Id)
8795 or else Is_Generic_Subprogram (Id))
8796 and then (Is_Potentially_Use_Visible (Id)
8797 or else Is_Intrinsic_Subprogram (Id)
8798 or else (Ekind (Id) in E_Function | E_Procedure
8799 and then Is_Generic_Actual_Subprogram (Id)))
8801 Mark_Parameters (Id);
8809 if Nkind (Id) in N_Op then
8811 -- At this point the left operand may not be resolved if we are
8812 -- encountering multiple operators next to eachother in an
8815 if Nkind (Id) in N_Binary_Op
8816 and then not (Nkind (Left_Opnd (Id)) in N_Op)
8818 Mark_Use_Type (Left_Opnd (Id));
8821 Mark_Use_Type (Right_Opnd (Id));
8824 -- Mark entity identifiers
8826 elsif Nkind (Id) in N_Has_Entity
8827 and then (Is_Potentially_Use_Visible (Entity (Id))
8828 or else (Is_Generic_Instance (Entity (Id))
8829 and then Is_Immediately_Visible (Entity (Id))))
8831 -- Ignore fully qualified names as they do not count as a "use" of
8834 if Nkind (Id) in N_Identifier | N_Operator_Symbol
8835 or else (Present (Prefix (Id))
8836 and then Scope (Entity (Id)) /= Entity (Prefix (Id)))
8838 Mark_Use_Clauses (Entity (Id));
8842 end Mark_Use_Clauses;
8844 --------------------------------
8845 -- Most_Descendant_Use_Clause --
8846 --------------------------------
8848 function Most_Descendant_Use_Clause
8849 (Clause1 : Entity_Id;
8850 Clause2 : Entity_Id) return Entity_Id
8856 if Clause1 = Clause2 then
8860 -- We determine which one is the most descendant by the scope distance
8861 -- to the ultimate parent unit.
8863 Scope1 := Entity_Of_Unit (Unit (Parent (Clause1)));
8864 Scope2 := Entity_Of_Unit (Unit (Parent (Clause2)));
8865 while Scope1 /= Standard_Standard
8866 and then Scope2 /= Standard_Standard
8868 Scope1 := Scope (Scope1);
8869 Scope2 := Scope (Scope2);
8871 if not Present (Scope1) then
8873 elsif not Present (Scope2) then
8878 if Scope1 = Standard_Standard then
8883 end Most_Descendant_Use_Clause;
8889 procedure Pop_Scope is
8890 SST : Scope_Stack_Entry renames Scope_Stack.Table (Scope_Stack.Last);
8891 S : constant Entity_Id := SST.Entity;
8894 if Debug_Flag_E then
8898 -- Set Default_Storage_Pool field of the library unit if necessary
8900 if Is_Package_Or_Generic_Package (S)
8902 Nkind (Parent (Unit_Declaration_Node (S))) = N_Compilation_Unit
8905 Aux : constant Node_Id :=
8906 Aux_Decls_Node (Parent (Unit_Declaration_Node (S)));
8908 if No (Default_Storage_Pool (Aux)) then
8909 Set_Default_Storage_Pool (Aux, Default_Pool);
8914 Scope_Suppress := SST.Save_Scope_Suppress;
8915 Local_Suppress_Stack_Top := SST.Save_Local_Suppress_Stack_Top;
8916 Check_Policy_List := SST.Save_Check_Policy_List;
8917 Default_Pool := SST.Save_Default_Storage_Pool;
8918 No_Tagged_Streams := SST.Save_No_Tagged_Streams;
8919 SPARK_Mode := SST.Save_SPARK_Mode;
8920 SPARK_Mode_Pragma := SST.Save_SPARK_Mode_Pragma;
8921 Default_SSO := SST.Save_Default_SSO;
8922 Uneval_Old := SST.Save_Uneval_Old;
8924 if Debug_Flag_W then
8925 Write_Str ("<-- exiting scope: ");
8926 Write_Name (Chars (Current_Scope));
8927 Write_Str (", Depth=");
8928 Write_Int (Int (Scope_Stack.Last));
8932 End_Use_Clauses (SST.First_Use_Clause);
8934 -- If the actions to be wrapped are still there they will get lost
8935 -- causing incomplete code to be generated. It is better to abort in
8936 -- this case (and we do the abort even with assertions off since the
8937 -- penalty is incorrect code generation).
8939 if SST.Actions_To_Be_Wrapped /= Scope_Actions'(others => No_List) then
8940 raise Program_Error;
8943 -- Free last subprogram name if allocated, and pop scope
8945 Free (SST.Last_Subprogram_Name);
8946 Scope_Stack.Decrement_Last;
8953 procedure Push_Scope (S : Entity_Id) is
8954 E : constant Entity_Id := Scope (S);
8957 if Ekind (S) = E_Void then
8960 -- Set scope depth if not a non-concurrent type, and we have not yet set
8961 -- the scope depth. This means that we have the first occurrence of the
8962 -- scope, and this is where the depth is set.
8964 elsif (not Is_Type (S) or else Is_Concurrent_Type (S))
8965 and then not Scope_Depth_Set (S)
8967 if S = Standard_Standard then
8968 Set_Scope_Depth_Value (S, Uint_0);
8970 elsif Is_Child_Unit (S) then
8971 Set_Scope_Depth_Value (S, Uint_1);
8973 elsif not Is_Record_Type (Current_Scope) then
8974 if Ekind (S) = E_Loop then
8975 Set_Scope_Depth_Value (S, Scope_Depth (Current_Scope));
8977 Set_Scope_Depth_Value (S, Scope_Depth (Current_Scope) + 1);
8982 Scope_Stack.Increment_Last;
8985 SST : Scope_Stack_Entry renames Scope_Stack.Table (Scope_Stack.Last);
8989 SST.Save_Scope_Suppress := Scope_Suppress;
8990 SST.Save_Local_Suppress_Stack_Top := Local_Suppress_Stack_Top;
8991 SST.Save_Check_Policy_List := Check_Policy_List;
8992 SST.Save_Default_Storage_Pool := Default_Pool;
8993 SST.Save_No_Tagged_Streams := No_Tagged_Streams;
8994 SST.Save_SPARK_Mode := SPARK_Mode;
8995 SST.Save_SPARK_Mode_Pragma := SPARK_Mode_Pragma;
8996 SST.Save_Default_SSO := Default_SSO;
8997 SST.Save_Uneval_Old := Uneval_Old;
8999 -- Each new scope pushed onto the scope stack inherits the component
9000 -- alignment of the previous scope. This emulates the "visibility"
9001 -- semantics of pragma Component_Alignment.
9003 if Scope_Stack.Last > Scope_Stack.First then
9004 SST.Component_Alignment_Default :=
9006 (Scope_Stack.Last - 1).Component_Alignment_Default;
9008 -- Otherwise, this is the first scope being pushed on the scope
9009 -- stack. Inherit the component alignment from the configuration
9010 -- form of pragma Component_Alignment (if any).
9013 SST.Component_Alignment_Default :=
9014 Configuration_Component_Alignment;
9017 SST.Last_Subprogram_Name := null;
9018 SST.Is_Transient := False;
9019 SST.Node_To_Be_Wrapped := Empty;
9020 SST.Pending_Freeze_Actions := No_List;
9021 SST.Actions_To_Be_Wrapped := (others => No_List);
9022 SST.First_Use_Clause := Empty;
9023 SST.Is_Active_Stack_Base := False;
9024 SST.Previous_Visibility := False;
9025 SST.Locked_Shared_Objects := No_Elist;
9028 if Debug_Flag_W then
9029 Write_Str ("--> new scope: ");
9030 Write_Name (Chars (Current_Scope));
9031 Write_Str (", Id=");
9032 Write_Int (Int (Current_Scope));
9033 Write_Str (", Depth=");
9034 Write_Int (Int (Scope_Stack.Last));
9038 -- Deal with copying flags from the previous scope to this one. This is
9039 -- not necessary if either scope is standard, or if the new scope is a
9042 if S /= Standard_Standard
9043 and then Scope (S) /= Standard_Standard
9044 and then not Is_Child_Unit (S)
9046 if Nkind (E) not in N_Entity then
9050 -- Copy categorization flags from Scope (S) to S, this is not done
9051 -- when Scope (S) is Standard_Standard since propagation is from
9052 -- library unit entity inwards. Copy other relevant attributes as
9053 -- well (Discard_Names in particular).
9055 -- We only propagate inwards for library level entities,
9056 -- inner level subprograms do not inherit the categorization.
9058 if Is_Library_Level_Entity (S) then
9059 Set_Is_Preelaborated (S, Is_Preelaborated (E));
9060 Set_Is_Shared_Passive (S, Is_Shared_Passive (E));
9061 Set_Discard_Names (S, Discard_Names (E));
9062 Set_Suppress_Value_Tracking_On_Call
9063 (S, Suppress_Value_Tracking_On_Call (E));
9064 Set_Categorization_From_Scope (E => S, Scop => E);
9068 if Is_Child_Unit (S)
9069 and then Present (E)
9070 and then Is_Package_Or_Generic_Package (E)
9072 Nkind (Parent (Unit_Declaration_Node (E))) = N_Compilation_Unit
9075 Aux : constant Node_Id :=
9076 Aux_Decls_Node (Parent (Unit_Declaration_Node (E)));
9078 if Present (Default_Storage_Pool (Aux)) then
9079 Default_Pool := Default_Storage_Pool (Aux);
9085 ---------------------
9086 -- Premature_Usage --
9087 ---------------------
9089 procedure Premature_Usage (N : Node_Id) is
9090 Kind : constant Node_Kind := Nkind (Parent (Entity (N)));
9091 E : Entity_Id := Entity (N);
9094 -- Within an instance, the analysis of the actual for a formal object
9095 -- does not see the name of the object itself. This is significant only
9096 -- if the object is an aggregate, where its analysis does not do any
9097 -- name resolution on component associations. (see 4717-008). In such a
9098 -- case, look for the visible homonym on the chain.
9100 if In_Instance and then Present (Homonym (E)) then
9102 while Present (E) and then not In_Open_Scopes (Scope (E)) loop
9108 Set_Etype (N, Etype (E));
9114 when N_Component_Declaration =>
9116 ("component&! cannot be used before end of record declaration",
9119 when N_Parameter_Specification =>
9121 ("formal parameter&! cannot be used before end of specification",
9124 when N_Discriminant_Specification =>
9126 ("discriminant&! cannot be used before end of discriminant part",
9129 when N_Procedure_Specification | N_Function_Specification =>
9131 ("subprogram&! cannot be used before end of its declaration",
9134 when N_Full_Type_Declaration | N_Subtype_Declaration =>
9136 ("type& cannot be used before end of its declaration!", N);
9140 ("object& cannot be used before end of its declaration!", N);
9142 -- If the premature reference appears as the expression in its own
9143 -- declaration, rewrite it to prevent compiler loops in subsequent
9144 -- uses of this mangled declaration in address clauses.
9146 if Nkind (Parent (N)) = N_Object_Declaration then
9147 Set_Entity (N, Any_Id);
9150 end Premature_Usage;
9152 ------------------------
9153 -- Present_System_Aux --
9154 ------------------------
9156 function Present_System_Aux (N : Node_Id := Empty) return Boolean is
9158 Aux_Name : Unit_Name_Type;
9159 Unum : Unit_Number_Type;
9164 function Find_System (C_Unit : Node_Id) return Entity_Id;
9165 -- Scan context clause of compilation unit to find with_clause
9172 function Find_System (C_Unit : Node_Id) return Entity_Id is
9173 With_Clause : Node_Id;
9176 With_Clause := First (Context_Items (C_Unit));
9177 while Present (With_Clause) loop
9178 if (Nkind (With_Clause) = N_With_Clause
9179 and then Chars (Name (With_Clause)) = Name_System)
9180 and then Comes_From_Source (With_Clause)
9191 -- Start of processing for Present_System_Aux
9194 -- The child unit may have been loaded and analyzed already
9196 if Present (System_Aux_Id) then
9199 -- If no previous pragma for System.Aux, nothing to load
9201 elsif No (System_Extend_Unit) then
9204 -- Use the unit name given in the pragma to retrieve the unit.
9205 -- Verify that System itself appears in the context clause of the
9206 -- current compilation. If System is not present, an error will
9207 -- have been reported already.
9210 With_Sys := Find_System (Cunit (Current_Sem_Unit));
9212 The_Unit := Unit (Cunit (Current_Sem_Unit));
9216 (Nkind (The_Unit) = N_Package_Body
9217 or else (Nkind (The_Unit) = N_Subprogram_Body
9218 and then not Acts_As_Spec (Cunit (Current_Sem_Unit))))
9220 With_Sys := Find_System (Library_Unit (Cunit (Current_Sem_Unit)));
9223 if No (With_Sys) and then Present (N) then
9225 -- If we are compiling a subunit, we need to examine its
9226 -- context as well (Current_Sem_Unit is the parent unit);
9228 The_Unit := Parent (N);
9229 while Nkind (The_Unit) /= N_Compilation_Unit loop
9230 The_Unit := Parent (The_Unit);
9233 if Nkind (Unit (The_Unit)) = N_Subunit then
9234 With_Sys := Find_System (The_Unit);
9238 if No (With_Sys) then
9242 Loc := Sloc (With_Sys);
9243 Get_Name_String (Chars (Expression (System_Extend_Unit)));
9244 Name_Buffer (8 .. Name_Len + 7) := Name_Buffer (1 .. Name_Len);
9245 Name_Buffer (1 .. 7) := "system.";
9246 Name_Buffer (Name_Len + 8) := '%';
9247 Name_Buffer (Name_Len + 9) := 's';
9248 Name_Len := Name_Len + 9;
9249 Aux_Name := Name_Find;
9253 (Load_Name => Aux_Name,
9256 Error_Node => With_Sys);
9258 if Unum /= No_Unit then
9259 Semantics (Cunit (Unum));
9261 Defining_Entity (Specification (Unit (Cunit (Unum))));
9264 Make_With_Clause (Loc,
9266 Make_Expanded_Name (Loc,
9267 Chars => Chars (System_Aux_Id),
9269 New_Occurrence_Of (Scope (System_Aux_Id), Loc),
9270 Selector_Name => New_Occurrence_Of (System_Aux_Id, Loc)));
9272 Set_Entity (Name (Withn), System_Aux_Id);
9274 Set_Corresponding_Spec (Withn, System_Aux_Id);
9275 Set_First_Name (Withn);
9276 Set_Implicit_With (Withn);
9277 Set_Library_Unit (Withn, Cunit (Unum));
9279 Insert_After (With_Sys, Withn);
9280 Mark_Rewrite_Insertion (Withn);
9281 Set_Context_Installed (Withn);
9285 -- Here if unit load failed
9288 Error_Msg_Name_1 := Name_System;
9289 Error_Msg_Name_2 := Chars (Expression (System_Extend_Unit));
9291 ("extension package `%.%` does not exist",
9292 Opt.System_Extend_Unit);
9296 end Present_System_Aux;
9298 -------------------------
9299 -- Restore_Scope_Stack --
9300 -------------------------
9302 procedure Restore_Scope_Stack
9304 Handle_Use : Boolean := True)
9306 SS_Last : constant Int := Scope_Stack.Last;
9310 -- Restore visibility of previous scope stack, if any, using the list
9311 -- we saved (we use Remove, since this list will not be used again).
9314 Elmt := Last_Elmt (List);
9315 exit when Elmt = No_Elmt;
9316 Set_Is_Immediately_Visible (Node (Elmt));
9317 Remove_Last_Elmt (List);
9320 -- Restore use clauses
9322 if SS_Last >= Scope_Stack.First
9323 and then Scope_Stack.Table (SS_Last).Entity /= Standard_Standard
9327 (Scope_Stack.Table (SS_Last).First_Use_Clause,
9328 Force_Installation => True);
9330 end Restore_Scope_Stack;
9332 ----------------------
9333 -- Save_Scope_Stack --
9334 ----------------------
9336 -- Save_Scope_Stack/Restore_Scope_Stack were originally designed to avoid
9337 -- consuming any memory. That is, Save_Scope_Stack took care of removing
9338 -- from immediate visibility entities and Restore_Scope_Stack took care
9339 -- of restoring their visibility analyzing the context of each entity. The
9340 -- problem of such approach is that it was fragile and caused unexpected
9341 -- visibility problems, and indeed one test was found where there was a
9344 -- Furthermore, the following experiment was carried out:
9346 -- - Save_Scope_Stack was modified to store in an Elist1 all those
9347 -- entities whose attribute Is_Immediately_Visible is modified
9348 -- from True to False.
9350 -- - Restore_Scope_Stack was modified to store in another Elist2
9351 -- all the entities whose attribute Is_Immediately_Visible is
9352 -- modified from False to True.
9354 -- - Extra code was added to verify that all the elements of Elist1
9355 -- are found in Elist2
9357 -- This test shows that there may be more occurrences of this problem which
9358 -- have not yet been detected. As a result, we replaced that approach by
9359 -- the current one in which Save_Scope_Stack returns the list of entities
9360 -- whose visibility is changed, and that list is passed to Restore_Scope_
9361 -- Stack to undo that change. This approach is simpler and safer, although
9362 -- it consumes more memory.
9364 function Save_Scope_Stack (Handle_Use : Boolean := True) return Elist_Id is
9365 Result : constant Elist_Id := New_Elmt_List;
9368 SS_Last : constant Int := Scope_Stack.Last;
9370 procedure Remove_From_Visibility (E : Entity_Id);
9371 -- If E is immediately visible then append it to the result and remove
9372 -- it temporarily from visibility.
9374 ----------------------------
9375 -- Remove_From_Visibility --
9376 ----------------------------
9378 procedure Remove_From_Visibility (E : Entity_Id) is
9380 if Is_Immediately_Visible (E) then
9381 Append_Elmt (E, Result);
9382 Set_Is_Immediately_Visible (E, False);
9384 end Remove_From_Visibility;
9386 -- Start of processing for Save_Scope_Stack
9389 if SS_Last >= Scope_Stack.First
9390 and then Scope_Stack.Table (SS_Last).Entity /= Standard_Standard
9393 End_Use_Clauses (Scope_Stack.Table (SS_Last).First_Use_Clause);
9396 -- If the call is from within a compilation unit, as when called from
9397 -- Rtsfind, make current entries in scope stack invisible while we
9398 -- analyze the new unit.
9400 for J in reverse 0 .. SS_Last loop
9401 exit when Scope_Stack.Table (J).Entity = Standard_Standard
9402 or else No (Scope_Stack.Table (J).Entity);
9404 S := Scope_Stack.Table (J).Entity;
9406 Remove_From_Visibility (S);
9408 E := First_Entity (S);
9409 while Present (E) loop
9410 Remove_From_Visibility (E);
9418 end Save_Scope_Stack;
9424 procedure Set_Use (L : List_Id) is
9430 while Present (Decl) loop
9431 if Nkind (Decl) = N_Use_Package_Clause then
9432 Chain_Use_Clause (Decl);
9433 Use_One_Package (Decl, Name (Decl));
9435 elsif Nkind (Decl) = N_Use_Type_Clause then
9436 Chain_Use_Clause (Decl);
9437 Use_One_Type (Subtype_Mark (Decl));
9446 -----------------------------
9447 -- Update_Use_Clause_Chain --
9448 -----------------------------
9450 procedure Update_Use_Clause_Chain is
9452 procedure Update_Chain_In_Scope (Level : Int);
9453 -- Iterate through one level in the scope stack verifying each use-type
9454 -- clause within said level is used then reset the Current_Use_Clause
9455 -- to a redundant use clause outside of the current ending scope if such
9458 ---------------------------
9459 -- Update_Chain_In_Scope --
9460 ---------------------------
9462 procedure Update_Chain_In_Scope (Level : Int) is
9467 -- Loop through all use clauses within the scope dictated by Level
9469 Curr := Scope_Stack.Table (Level).First_Use_Clause;
9470 while Present (Curr) loop
9472 -- Retrieve the subtype mark or name within the current current
9475 if Nkind (Curr) = N_Use_Type_Clause then
9476 N := Subtype_Mark (Curr);
9481 -- If warnings for unreferenced entities are enabled and the
9482 -- current use clause has not been marked effective.
9484 if Check_Unreferenced
9485 and then Comes_From_Source (Curr)
9486 and then not Is_Effective_Use_Clause (Curr)
9487 and then not In_Instance
9488 and then not In_Inlined_Body
9490 -- We are dealing with a potentially unused use_package_clause
9492 if Nkind (Curr) = N_Use_Package_Clause then
9494 -- Renamings and formal subprograms may cause the associated
9495 -- node to be marked as effective instead of the original.
9497 if not (Present (Associated_Node (N))
9500 (Associated_Node (N)))
9501 and then Is_Effective_Use_Clause
9503 (Associated_Node (N))))
9505 Error_Msg_Node_1 := Entity (N);
9507 ("use clause for package & has no effect?u?",
9511 -- We are dealing with an unused use_type_clause
9514 Error_Msg_Node_1 := Etype (N);
9516 ("use clause for } has no effect?u?", Curr, Etype (N));
9520 -- Verify that we haven't already processed a redundant
9521 -- use_type_clause within the same scope before we move the
9522 -- current use clause up to a previous one for type T.
9524 if Present (Prev_Use_Clause (Curr)) then
9525 Set_Current_Use_Clause (Entity (N), Prev_Use_Clause (Curr));
9528 Next_Use_Clause (Curr);
9530 end Update_Chain_In_Scope;
9532 -- Start of processing for Update_Use_Clause_Chain
9535 Update_Chain_In_Scope (Scope_Stack.Last);
9537 -- Deal with use clauses within the context area if the current
9538 -- scope is a compilation unit.
9540 if Is_Compilation_Unit (Current_Scope)
9541 and then Sloc (Scope_Stack.Table
9542 (Scope_Stack.Last - 1).Entity) = Standard_Location
9544 Update_Chain_In_Scope (Scope_Stack.Last - 1);
9546 end Update_Use_Clause_Chain;
9548 ---------------------
9549 -- Use_One_Package --
9550 ---------------------
9552 procedure Use_One_Package
9554 Pack_Name : Entity_Id := Empty;
9555 Force : Boolean := False)
9557 procedure Note_Redundant_Use (Clause : Node_Id);
9558 -- Mark the name in a use clause as redundant if the corresponding
9559 -- entity is already use-visible. Emit a warning if the use clause comes
9560 -- from source and the proper warnings are enabled.
9562 ------------------------
9563 -- Note_Redundant_Use --
9564 ------------------------
9566 procedure Note_Redundant_Use (Clause : Node_Id) is
9567 Decl : constant Node_Id := Parent (Clause);
9568 Pack_Name : constant Entity_Id := Entity (Clause);
9570 Cur_Use : Node_Id := Current_Use_Clause (Pack_Name);
9571 Prev_Use : Node_Id := Empty;
9572 Redundant : Node_Id := Empty;
9573 -- The Use_Clause which is actually redundant. In the simplest case
9574 -- it is Pack itself, but when we compile a body we install its
9575 -- context before that of its spec, in which case it is the
9576 -- use_clause in the spec that will appear to be redundant, and we
9577 -- want the warning to be placed on the body. Similar complications
9578 -- appear when the redundancy is between a child unit and one of its
9582 -- Could be renamed...
9584 if No (Cur_Use) then
9585 Cur_Use := Current_Use_Clause (Renamed_Entity (Pack_Name));
9588 Set_Redundant_Use (Clause, True);
9590 -- Do not check for redundant use if clause is generated, or in an
9591 -- instance, or in a predefined unit to avoid misleading warnings
9592 -- that may occur as part of a rtsfind load.
9594 if not Comes_From_Source (Clause)
9596 or else not Warn_On_Redundant_Constructs
9597 or else Is_Predefined_Unit (Current_Sem_Unit)
9602 if not Is_Compilation_Unit (Current_Scope) then
9604 -- If the use_clause is in an inner scope, it is made redundant by
9605 -- some clause in the current context, with one exception: If we
9606 -- are compiling a nested package body, and the use_clause comes
9607 -- from then corresponding spec, the clause is not necessarily
9608 -- fully redundant, so we should not warn. If a warning was
9609 -- warranted, it would have been given when the spec was
9612 if Nkind (Parent (Decl)) = N_Package_Specification then
9614 Package_Spec_Entity : constant Entity_Id :=
9615 Defining_Unit_Name (Parent (Decl));
9617 if In_Package_Body (Package_Spec_Entity) then
9623 Redundant := Clause;
9624 Prev_Use := Cur_Use;
9626 elsif Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Body then
9628 Cur_Unit : constant Unit_Number_Type :=
9629 Get_Source_Unit (Cur_Use);
9630 New_Unit : constant Unit_Number_Type :=
9631 Get_Source_Unit (Clause);
9636 if Cur_Unit = New_Unit then
9638 -- Redundant clause in same body
9640 Redundant := Clause;
9641 Prev_Use := Cur_Use;
9643 elsif Cur_Unit = Current_Sem_Unit then
9645 -- If the new clause is not in the current unit it has been
9646 -- analyzed first, and it makes the other one redundant.
9647 -- However, if the new clause appears in a subunit, Cur_Unit
9648 -- is still the parent, and in that case the redundant one
9649 -- is the one appearing in the subunit.
9651 if Nkind (Unit (Cunit (New_Unit))) = N_Subunit then
9652 Redundant := Clause;
9653 Prev_Use := Cur_Use;
9655 -- Most common case: redundant clause in body, original
9656 -- clause in spec. Current scope is spec entity.
9658 elsif Current_Scope = Cunit_Entity (Current_Sem_Unit) then
9659 Redundant := Cur_Use;
9663 -- The new clause may appear in an unrelated unit, when
9664 -- the parents of a generic are being installed prior to
9665 -- instantiation. In this case there must be no warning.
9666 -- We detect this case by checking whether the current
9667 -- top of the stack is related to the current
9670 Scop := Current_Scope;
9671 while Present (Scop)
9672 and then Scop /= Standard_Standard
9674 if Is_Compilation_Unit (Scop)
9675 and then not Is_Child_Unit (Scop)
9679 elsif Scop = Cunit_Entity (Current_Sem_Unit) then
9683 Scop := Scope (Scop);
9686 Redundant := Cur_Use;
9690 elsif New_Unit = Current_Sem_Unit then
9691 Redundant := Clause;
9692 Prev_Use := Cur_Use;
9695 -- Neither is the current unit, so they appear in parent or
9696 -- sibling units. Warning will be emitted elsewhere.
9702 elsif Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Declaration
9703 and then Present (Parent_Spec (Unit (Cunit (Current_Sem_Unit))))
9705 -- Use_clause is in child unit of current unit, and the child unit
9706 -- appears in the context of the body of the parent, so it has
9707 -- been installed first, even though it is the redundant one.
9708 -- Depending on their placement in the context, the visible or the
9709 -- private parts of the two units, either might appear as
9710 -- redundant, but the message has to be on the current unit.
9712 if Get_Source_Unit (Cur_Use) = Current_Sem_Unit then
9713 Redundant := Cur_Use;
9716 Redundant := Clause;
9717 Prev_Use := Cur_Use;
9720 -- If the new use clause appears in the private part of a parent
9721 -- unit it may appear to be redundant w.r.t. a use clause in a
9722 -- child unit, but the previous use clause was needed in the
9723 -- visible part of the child, and no warning should be emitted.
9725 if Nkind (Parent (Decl)) = N_Package_Specification
9726 and then List_Containing (Decl) =
9727 Private_Declarations (Parent (Decl))
9730 Par : constant Entity_Id :=
9731 Defining_Entity (Parent (Decl));
9732 Spec : constant Node_Id :=
9733 Specification (Unit (Cunit (Current_Sem_Unit)));
9734 Cur_List : constant List_Id := List_Containing (Cur_Use);
9737 if Is_Compilation_Unit (Par)
9738 and then Par /= Cunit_Entity (Current_Sem_Unit)
9740 if Cur_List = Context_Items (Cunit (Current_Sem_Unit))
9741 or else Cur_List = Visible_Declarations (Spec)
9749 -- Finally, if the current use clause is in the context then the
9750 -- clause is redundant when it is nested within the unit.
9752 elsif Nkind (Parent (Cur_Use)) = N_Compilation_Unit
9753 and then Nkind (Parent (Parent (Clause))) /= N_Compilation_Unit
9754 and then Get_Source_Unit (Cur_Use) = Get_Source_Unit (Clause)
9756 Redundant := Clause;
9757 Prev_Use := Cur_Use;
9760 if Present (Redundant) and then Parent (Redundant) /= Prev_Use then
9762 -- Make sure we are looking at most-descendant use_package_clause
9763 -- by traversing the chain with Find_Most_Prev and then verifying
9764 -- there is no scope manipulation via Most_Descendant_Use_Clause.
9766 if Nkind (Prev_Use) = N_Use_Package_Clause
9768 (Nkind (Parent (Prev_Use)) /= N_Compilation_Unit
9769 or else Most_Descendant_Use_Clause
9770 (Prev_Use, Find_Most_Prev (Prev_Use)) /= Prev_Use)
9772 Prev_Use := Find_Most_Prev (Prev_Use);
9775 Error_Msg_Sloc := Sloc (Prev_Use);
9776 Error_Msg_NE -- CODEFIX
9777 ("& is already use-visible through previous use_clause #?r?",
9778 Redundant, Pack_Name);
9780 end Note_Redundant_Use;
9784 Current_Instance : Entity_Id := Empty;
9788 Private_With_OK : Boolean := False;
9791 -- Start of processing for Use_One_Package
9794 -- Use_One_Package may have been called recursively to handle an
9795 -- implicit use for a auxiliary system package, so set P accordingly
9796 -- and skip redundancy checks.
9798 if No (Pack_Name) and then Present_System_Aux (N) then
9801 -- Check for redundant use_package_clauses
9804 -- Ignore cases where we are dealing with a non user defined package
9805 -- like Standard_Standard or something other than a valid package.
9807 if not Is_Entity_Name (Pack_Name)
9808 or else No (Entity (Pack_Name))
9809 or else Ekind (Entity (Pack_Name)) /= E_Package
9814 -- When a renaming exists we must check it for redundancy. The
9815 -- original package would have already been seen at this point.
9817 if Present (Renamed_Object (Entity (Pack_Name))) then
9818 P := Renamed_Object (Entity (Pack_Name));
9820 P := Entity (Pack_Name);
9823 -- Check for redundant clauses then set the current use clause for
9824 -- P if were are not "forcing" an installation from a scope
9825 -- reinstallation that is done throughout analysis for various
9829 Note_Redundant_Use (Pack_Name);
9832 Set_Current_Use_Clause (P, N);
9837 -- Warn about detected redundant clauses
9840 and then In_Open_Scopes (P)
9841 and then not Is_Hidden_Open_Scope (P)
9843 if Warn_On_Redundant_Constructs and then P = Current_Scope then
9844 Error_Msg_NE -- CODEFIX
9845 ("& is already use-visible within itself?r?",
9852 -- Set P back to the non-renamed package so that visiblilty of the
9853 -- entities within the package can be properly set below.
9855 P := Entity (Pack_Name);
9859 Set_Current_Use_Clause (P, N);
9861 -- Ada 2005 (AI-50217): Check restriction
9863 if From_Limited_With (P) then
9864 Error_Msg_N ("limited withed package cannot appear in use clause", N);
9867 -- Find enclosing instance, if any
9870 Current_Instance := Current_Scope;
9871 while not Is_Generic_Instance (Current_Instance) loop
9872 Current_Instance := Scope (Current_Instance);
9875 if No (Hidden_By_Use_Clause (N)) then
9876 Set_Hidden_By_Use_Clause (N, New_Elmt_List);
9880 -- If unit is a package renaming, indicate that the renamed package is
9881 -- also in use (the flags on both entities must remain consistent, and a
9882 -- subsequent use of either of them should be recognized as redundant).
9884 if Present (Renamed_Object (P)) then
9885 Set_In_Use (Renamed_Object (P));
9886 Set_Current_Use_Clause (Renamed_Object (P), N);
9887 Real_P := Renamed_Object (P);
9892 -- Ada 2005 (AI-262): Check the use_clause of a private withed package
9893 -- found in the private part of a package specification
9895 if In_Private_Part (Current_Scope)
9896 and then Has_Private_With (P)
9897 and then Is_Child_Unit (Current_Scope)
9898 and then Is_Child_Unit (P)
9899 and then Is_Ancestor_Package (Scope (Current_Scope), P)
9901 Private_With_OK := True;
9904 -- Loop through entities in one package making them potentially
9907 Id := First_Entity (P);
9909 and then (Id /= First_Private_Entity (P)
9910 or else Private_With_OK) -- Ada 2005 (AI-262)
9912 Prev := Current_Entity (Id);
9913 while Present (Prev) loop
9914 if Is_Immediately_Visible (Prev)
9915 and then (not Is_Overloadable (Prev)
9916 or else not Is_Overloadable (Id)
9917 or else (Type_Conformant (Id, Prev)))
9919 if No (Current_Instance) then
9921 -- Potentially use-visible entity remains hidden
9923 goto Next_Usable_Entity;
9925 -- A use clause within an instance hides outer global entities,
9926 -- which are not used to resolve local entities in the
9927 -- instance. Note that the predefined entities in Standard
9928 -- could not have been hidden in the generic by a use clause,
9929 -- and therefore remain visible. Other compilation units whose
9930 -- entities appear in Standard must be hidden in an instance.
9932 -- To determine whether an entity is external to the instance
9933 -- we compare the scope depth of its scope with that of the
9934 -- current instance. However, a generic actual of a subprogram
9935 -- instance is declared in the wrapper package but will not be
9936 -- hidden by a use-visible entity. similarly, an entity that is
9937 -- declared in an enclosing instance will not be hidden by an
9938 -- an entity declared in a generic actual, which can only have
9939 -- been use-visible in the generic and will not have hidden the
9940 -- entity in the generic parent.
9942 -- If Id is called Standard, the predefined package with the
9943 -- same name is in the homonym chain. It has to be ignored
9944 -- because it has no defined scope (being the only entity in
9945 -- the system with this mandated behavior).
9947 elsif not Is_Hidden (Id)
9948 and then Present (Scope (Prev))
9949 and then not Is_Wrapper_Package (Scope (Prev))
9950 and then Scope_Depth (Scope (Prev)) <
9951 Scope_Depth (Current_Instance)
9952 and then (Scope (Prev) /= Standard_Standard
9953 or else Sloc (Prev) > Standard_Location)
9955 if In_Open_Scopes (Scope (Prev))
9956 and then Is_Generic_Instance (Scope (Prev))
9957 and then Present (Associated_Formal_Package (P))
9962 Set_Is_Potentially_Use_Visible (Id);
9963 Set_Is_Immediately_Visible (Prev, False);
9964 Append_Elmt (Prev, Hidden_By_Use_Clause (N));
9968 -- A user-defined operator is not use-visible if the predefined
9969 -- operator for the type is immediately visible, which is the case
9970 -- if the type of the operand is in an open scope. This does not
9971 -- apply to user-defined operators that have operands of different
9972 -- types, because the predefined mixed mode operations (multiply
9973 -- and divide) apply to universal types and do not hide anything.
9975 elsif Ekind (Prev) = E_Operator
9976 and then Operator_Matches_Spec (Prev, Id)
9977 and then In_Open_Scopes
9978 (Scope (Base_Type (Etype (First_Formal (Id)))))
9979 and then (No (Next_Formal (First_Formal (Id)))
9980 or else Etype (First_Formal (Id)) =
9981 Etype (Next_Formal (First_Formal (Id)))
9982 or else Chars (Prev) = Name_Op_Expon)
9984 goto Next_Usable_Entity;
9986 -- In an instance, two homonyms may become use_visible through the
9987 -- actuals of distinct formal packages. In the generic, only the
9988 -- current one would have been visible, so make the other one
9991 -- In certain pathological cases it is possible that unrelated
9992 -- homonyms from distinct formal packages may exist in an
9993 -- uninstalled scope. We must test for that here.
9995 elsif Present (Current_Instance)
9996 and then Is_Potentially_Use_Visible (Prev)
9997 and then not Is_Overloadable (Prev)
9998 and then Scope (Id) /= Scope (Prev)
9999 and then Used_As_Generic_Actual (Scope (Prev))
10000 and then Used_As_Generic_Actual (Scope (Id))
10001 and then Is_List_Member (Scope (Prev))
10002 and then not In_Same_List (Current_Use_Clause (Scope (Prev)),
10003 Current_Use_Clause (Scope (Id)))
10005 Set_Is_Potentially_Use_Visible (Prev, False);
10006 Append_Elmt (Prev, Hidden_By_Use_Clause (N));
10009 Prev := Homonym (Prev);
10012 -- On exit, we know entity is not hidden, unless it is private
10014 if not Is_Hidden (Id)
10015 and then ((not Is_Child_Unit (Id)) or else Is_Visible_Lib_Unit (Id))
10017 Set_Is_Potentially_Use_Visible (Id);
10019 if Is_Private_Type (Id) and then Present (Full_View (Id)) then
10020 Set_Is_Potentially_Use_Visible (Full_View (Id));
10024 <<Next_Usable_Entity>>
10028 -- Child units are also made use-visible by a use clause, but they may
10029 -- appear after all visible declarations in the parent entity list.
10031 while Present (Id) loop
10032 if Is_Child_Unit (Id) and then Is_Visible_Lib_Unit (Id) then
10033 Set_Is_Potentially_Use_Visible (Id);
10039 if Chars (Real_P) = Name_System
10040 and then Scope (Real_P) = Standard_Standard
10041 and then Present_System_Aux (N)
10043 Use_One_Package (N);
10045 end Use_One_Package;
10051 procedure Use_One_Type
10053 Installed : Boolean := False;
10054 Force : Boolean := False)
10056 function Spec_Reloaded_For_Body return Boolean;
10057 -- Determine whether the compilation unit is a package body and the use
10058 -- type clause is in the spec of the same package. Even though the spec
10059 -- was analyzed first, its context is reloaded when analysing the body.
10061 procedure Use_Class_Wide_Operations (Typ : Entity_Id);
10062 -- AI05-150: if the use_type_clause carries the "all" qualifier,
10063 -- class-wide operations of ancestor types are use-visible if the
10064 -- ancestor type is visible.
10066 ----------------------------
10067 -- Spec_Reloaded_For_Body --
10068 ----------------------------
10070 function Spec_Reloaded_For_Body return Boolean is
10072 if Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Body then
10074 Spec : constant Node_Id :=
10075 Parent (List_Containing (Parent (Id)));
10078 -- Check whether type is declared in a package specification,
10079 -- and current unit is the corresponding package body. The
10080 -- use clauses themselves may be within a nested package.
10083 Nkind (Spec) = N_Package_Specification
10084 and then In_Same_Source_Unit
10085 (Corresponding_Body (Parent (Spec)),
10086 Cunit_Entity (Current_Sem_Unit));
10091 end Spec_Reloaded_For_Body;
10093 -------------------------------
10094 -- Use_Class_Wide_Operations --
10095 -------------------------------
10097 procedure Use_Class_Wide_Operations (Typ : Entity_Id) is
10098 function Is_Class_Wide_Operation_Of
10100 T : Entity_Id) return Boolean;
10101 -- Determine whether a subprogram has a class-wide parameter or
10102 -- result that is T'Class.
10104 ---------------------------------
10105 -- Is_Class_Wide_Operation_Of --
10106 ---------------------------------
10108 function Is_Class_Wide_Operation_Of
10110 T : Entity_Id) return Boolean
10112 Formal : Entity_Id;
10115 Formal := First_Formal (Op);
10116 while Present (Formal) loop
10117 if Etype (Formal) = Class_Wide_Type (T) then
10121 Next_Formal (Formal);
10124 if Etype (Op) = Class_Wide_Type (T) then
10129 end Is_Class_Wide_Operation_Of;
10136 -- Start of processing for Use_Class_Wide_Operations
10139 Scop := Scope (Typ);
10140 if not Is_Hidden (Scop) then
10141 Ent := First_Entity (Scop);
10142 while Present (Ent) loop
10143 if Is_Overloadable (Ent)
10144 and then Is_Class_Wide_Operation_Of (Ent, Typ)
10145 and then not Is_Potentially_Use_Visible (Ent)
10147 Set_Is_Potentially_Use_Visible (Ent);
10148 Append_Elmt (Ent, Used_Operations (Parent (Id)));
10155 if Is_Derived_Type (Typ) then
10156 Use_Class_Wide_Operations (Etype (Base_Type (Typ)));
10158 end Use_Class_Wide_Operations;
10163 Is_Known_Used : Boolean;
10164 Op_List : Elist_Id;
10167 -- Start of processing for Use_One_Type
10170 if Entity (Id) = Any_Type then
10174 -- It is the type determined by the subtype mark (8.4(8)) whose
10175 -- operations become potentially use-visible.
10177 T := Base_Type (Entity (Id));
10179 -- Either the type itself is used, the package where it is declared is
10180 -- in use or the entity is declared in the current package, thus
10185 and then ((Present (Current_Use_Clause (T))
10186 and then All_Present (Current_Use_Clause (T)))
10187 or else not All_Present (Parent (Id))))
10188 or else In_Use (Scope (T))
10189 or else Scope (T) = Current_Scope;
10191 Set_Redundant_Use (Id,
10192 Is_Known_Used or else Is_Potentially_Use_Visible (T));
10194 if Ekind (T) = E_Incomplete_Type then
10195 Error_Msg_N ("premature usage of incomplete type", Id);
10197 elsif In_Open_Scopes (Scope (T)) then
10200 -- A limited view cannot appear in a use_type_clause. However, an access
10201 -- type whose designated type is limited has the flag but is not itself
10202 -- a limited view unless we only have a limited view of its enclosing
10205 elsif From_Limited_With (T) and then From_Limited_With (Scope (T)) then
10207 ("incomplete type from limited view cannot appear in use clause",
10210 -- If the use clause is redundant, Used_Operations will usually be
10211 -- empty, but we need to set it to empty here in one case: If we are
10212 -- instantiating a generic library unit, then we install the ancestors
10213 -- of that unit in the scope stack, which involves reprocessing use
10214 -- clauses in those ancestors. Such a use clause will typically have a
10215 -- nonempty Used_Operations unless it was redundant in the generic unit,
10216 -- even if it is redundant at the place of the instantiation.
10218 elsif Redundant_Use (Id) then
10220 -- We must avoid incorrectly setting the Current_Use_Clause when we
10221 -- are working with a redundant clause that has already been linked
10222 -- in the Prev_Use_Clause chain, otherwise the chain will break.
10224 if Present (Current_Use_Clause (T))
10225 and then Present (Prev_Use_Clause (Current_Use_Clause (T)))
10226 and then Parent (Id) = Prev_Use_Clause (Current_Use_Clause (T))
10230 Set_Current_Use_Clause (T, Parent (Id));
10233 Set_Used_Operations (Parent (Id), New_Elmt_List);
10235 -- If the subtype mark designates a subtype in a different package,
10236 -- we have to check that the parent type is visible, otherwise the
10237 -- use_type_clause is a no-op. Not clear how to do that???
10240 Set_Current_Use_Clause (T, Parent (Id));
10243 -- If T is tagged, primitive operators on class-wide operands are
10244 -- also deemed available. Note that this is really necessary only
10245 -- in semantics-only mode, because the primitive operators are not
10246 -- fully constructed in this mode, but we do it in all modes for the
10247 -- sake of uniformity, as this should not matter in practice.
10249 if Is_Tagged_Type (T) then
10250 Set_In_Use (Class_Wide_Type (T));
10253 -- Iterate over primitive operations of the type. If an operation is
10254 -- already use_visible, it is the result of a previous use_clause,
10255 -- and already appears on the corresponding entity chain. If the
10256 -- clause is being reinstalled, operations are already use-visible.
10262 Op_List := Collect_Primitive_Operations (T);
10263 Elmt := First_Elmt (Op_List);
10264 while Present (Elmt) loop
10265 if (Nkind (Node (Elmt)) = N_Defining_Operator_Symbol
10266 or else Chars (Node (Elmt)) in Any_Operator_Name)
10267 and then not Is_Hidden (Node (Elmt))
10268 and then not Is_Potentially_Use_Visible (Node (Elmt))
10270 Set_Is_Potentially_Use_Visible (Node (Elmt));
10271 Append_Elmt (Node (Elmt), Used_Operations (Parent (Id)));
10273 elsif Ada_Version >= Ada_2012
10274 and then All_Present (Parent (Id))
10275 and then not Is_Hidden (Node (Elmt))
10276 and then not Is_Potentially_Use_Visible (Node (Elmt))
10278 Set_Is_Potentially_Use_Visible (Node (Elmt));
10279 Append_Elmt (Node (Elmt), Used_Operations (Parent (Id)));
10286 if Ada_Version >= Ada_2012
10287 and then All_Present (Parent (Id))
10288 and then Is_Tagged_Type (T)
10290 Use_Class_Wide_Operations (T);
10294 -- If warning on redundant constructs, check for unnecessary WITH
10297 and then Warn_On_Redundant_Constructs
10298 and then Is_Known_Used
10300 -- with P; with P; use P;
10301 -- package P is package X is package body X is
10302 -- type T ... use P.T;
10304 -- The compilation unit is the body of X. GNAT first compiles the
10305 -- spec of X, then proceeds to the body. At that point P is marked
10306 -- as use visible. The analysis then reinstalls the spec along with
10307 -- its context. The use clause P.T is now recognized as redundant,
10308 -- but in the wrong context. Do not emit a warning in such cases.
10309 -- Do not emit a warning either if we are in an instance, there is
10310 -- no redundancy between an outer use_clause and one that appears
10311 -- within the generic.
10313 and then not Spec_Reloaded_For_Body
10314 and then not In_Instance
10315 and then not In_Inlined_Body
10317 -- The type already has a use clause
10321 -- Case where we know the current use clause for the type
10323 if Present (Current_Use_Clause (T)) then
10324 Use_Clause_Known : declare
10325 Clause1 : constant Node_Id :=
10326 Find_Most_Prev (Current_Use_Clause (T));
10327 Clause2 : constant Node_Id := Parent (Id);
10334 -- Start of processing for Use_Clause_Known
10337 -- If both current use_type_clause and the use_type_clause
10338 -- for the type are at the compilation unit level, one of
10339 -- the units must be an ancestor of the other, and the
10340 -- warning belongs on the descendant.
10342 if Nkind (Parent (Clause1)) = N_Compilation_Unit
10344 Nkind (Parent (Clause2)) = N_Compilation_Unit
10346 -- If the unit is a subprogram body that acts as spec,
10347 -- the context clause is shared with the constructed
10348 -- subprogram spec. Clearly there is no redundancy.
10350 if Clause1 = Clause2 then
10354 Unit1 := Unit (Parent (Clause1));
10355 Unit2 := Unit (Parent (Clause2));
10357 -- If both clauses are on same unit, or one is the body
10358 -- of the other, or one of them is in a subunit, report
10359 -- redundancy on the later one.
10361 if Unit1 = Unit2 or else Nkind (Unit1) = N_Subunit then
10362 Error_Msg_Sloc := Sloc (Current_Use_Clause (T));
10363 Error_Msg_NE -- CODEFIX
10364 ("& is already use-visible through previous "
10365 & "use_type_clause #??", Clause1, T);
10368 elsif Nkind (Unit2) in N_Package_Body | N_Subprogram_Body
10369 and then Nkind (Unit1) /= Nkind (Unit2)
10370 and then Nkind (Unit1) /= N_Subunit
10372 Error_Msg_Sloc := Sloc (Clause1);
10373 Error_Msg_NE -- CODEFIX
10374 ("& is already use-visible through previous "
10375 & "use_type_clause #??", Current_Use_Clause (T), T);
10379 -- There is a redundant use_type_clause in a child unit.
10380 -- Determine which of the units is more deeply nested.
10381 -- If a unit is a package instance, retrieve the entity
10382 -- and its scope from the instance spec.
10384 Ent1 := Entity_Of_Unit (Unit1);
10385 Ent2 := Entity_Of_Unit (Unit2);
10387 if Scope (Ent2) = Standard_Standard then
10388 Error_Msg_Sloc := Sloc (Current_Use_Clause (T));
10391 elsif Scope (Ent1) = Standard_Standard then
10392 Error_Msg_Sloc := Sloc (Id);
10395 -- If both units are child units, we determine which one
10396 -- is the descendant by the scope distance to the
10397 -- ultimate parent unit.
10405 S1 := Scope (Ent1);
10406 S2 := Scope (Ent2);
10408 and then Present (S2)
10409 and then S1 /= Standard_Standard
10410 and then S2 /= Standard_Standard
10416 if S1 = Standard_Standard then
10417 Error_Msg_Sloc := Sloc (Id);
10420 Error_Msg_Sloc := Sloc (Current_Use_Clause (T));
10426 if Parent (Id) /= Err_No then
10427 if Most_Descendant_Use_Clause
10428 (Err_No, Parent (Id)) = Parent (Id)
10430 Error_Msg_Sloc := Sloc (Err_No);
10431 Err_No := Parent (Id);
10434 Error_Msg_NE -- CODEFIX
10435 ("& is already use-visible through previous "
10436 & "use_type_clause #??", Err_No, Id);
10439 -- Case where current use_type_clause and use_type_clause
10440 -- for the type are not both at the compilation unit level.
10441 -- In this case we don't have location information.
10444 Error_Msg_NE -- CODEFIX
10445 ("& is already use-visible through previous "
10446 & "use_type_clause??", Id, T);
10448 end Use_Clause_Known;
10450 -- Here if Current_Use_Clause is not set for T, another case where
10451 -- we do not have the location information available.
10454 Error_Msg_NE -- CODEFIX
10455 ("& is already use-visible through previous "
10456 & "use_type_clause??", Id, T);
10459 -- The package where T is declared is already used
10461 elsif In_Use (Scope (T)) then
10462 -- Due to expansion of contracts we could be attempting to issue
10463 -- a spurious warning - so verify there is a previous use clause.
10465 if Current_Use_Clause (Scope (T)) /=
10466 Find_Most_Prev (Current_Use_Clause (Scope (T)))
10469 Sloc (Find_Most_Prev (Current_Use_Clause (Scope (T))));
10470 Error_Msg_NE -- CODEFIX
10471 ("& is already use-visible through package use clause #??",
10475 -- The current scope is the package where T is declared
10478 Error_Msg_Node_2 := Scope (T);
10479 Error_Msg_NE -- CODEFIX
10480 ("& is already use-visible inside package &??", Id, T);
10489 procedure Write_Info is
10490 Id : Entity_Id := First_Entity (Current_Scope);
10493 -- No point in dumping standard entities
10495 if Current_Scope = Standard_Standard then
10499 Write_Str ("========================================================");
10501 Write_Str (" Defined Entities in ");
10502 Write_Name (Chars (Current_Scope));
10504 Write_Str ("========================================================");
10508 Write_Str ("-- none --");
10512 while Present (Id) loop
10513 Write_Entity_Info (Id, " ");
10518 if Scope (Current_Scope) = Standard_Standard then
10520 -- Print information on the current unit itself
10522 Write_Entity_Info (Current_Scope, " ");
10535 for J in reverse 1 .. Scope_Stack.Last loop
10536 S := Scope_Stack.Table (J).Entity;
10537 Write_Int (Int (S));
10538 Write_Str (" === ");
10539 Write_Name (Chars (S));
10548 procedure we (S : Entity_Id) is
10551 E := First_Entity (S);
10552 while Present (E) loop
10553 Write_Int (Int (E));
10554 Write_Str (" === ");
10555 Write_Name (Chars (E));