1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2015, 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 Fname; use Fname;
35 with Freeze; use Freeze;
36 with Ghost; use Ghost;
37 with Impunit; use Impunit;
39 with Lib.Load; use Lib.Load;
40 with Lib.Xref; use Lib.Xref;
41 with Namet; use Namet;
42 with Namet.Sp; use Namet.Sp;
43 with Nlists; use Nlists;
44 with Nmake; use Nmake;
46 with Output; use Output;
47 with Restrict; use Restrict;
48 with Rident; use Rident;
49 with Rtsfind; use Rtsfind;
51 with Sem_Aux; use Sem_Aux;
52 with Sem_Cat; use Sem_Cat;
53 with Sem_Ch3; use Sem_Ch3;
54 with Sem_Ch4; use Sem_Ch4;
55 with Sem_Ch6; use Sem_Ch6;
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_Eval; use Sem_Eval;
62 with Sem_Res; use Sem_Res;
63 with Sem_Util; use Sem_Util;
64 with Sem_Type; use Sem_Type;
65 with Stand; use Stand;
66 with Sinfo; use Sinfo;
67 with Sinfo.CN; use Sinfo.CN;
68 with Snames; use Snames;
69 with Style; use Style;
71 with Tbuild; use Tbuild;
72 with Uintp; use Uintp;
74 package body Sem_Ch8 is
76 ------------------------------------
77 -- Visibility and Name Resolution --
78 ------------------------------------
80 -- This package handles name resolution and the collection of possible
81 -- interpretations for overloaded names, prior to overload resolution.
83 -- Name resolution is the process that establishes a mapping between source
84 -- identifiers and the entities they denote at each point in the program.
85 -- Each entity is represented by a defining occurrence. Each identifier
86 -- that denotes an entity points to the corresponding defining occurrence.
87 -- This is the entity of the applied occurrence. Each occurrence holds
88 -- an index into the names table, where source identifiers are stored.
90 -- Each entry in the names table for an identifier or designator uses the
91 -- Info pointer to hold a link to the currently visible entity that has
92 -- this name (see subprograms Get_Name_Entity_Id and Set_Name_Entity_Id
93 -- in package Sem_Util). The visibility is initialized at the beginning of
94 -- semantic processing to make entities in package Standard immediately
95 -- visible. The visibility table is used in a more subtle way when
96 -- compiling subunits (see below).
98 -- Entities that have the same name (i.e. homonyms) are chained. In the
99 -- case of overloaded entities, this chain holds all the possible meanings
100 -- of a given identifier. The process of overload resolution uses type
101 -- information to select from this chain the unique meaning of a given
104 -- Entities are also chained in their scope, through the Next_Entity link.
105 -- As a consequence, the name space is organized as a sparse matrix, where
106 -- each row corresponds to a scope, and each column to a source identifier.
107 -- Open scopes, that is to say scopes currently being compiled, have their
108 -- corresponding rows of entities in order, innermost scope first.
110 -- The scopes of packages that are mentioned in context clauses appear in
111 -- no particular order, interspersed among open scopes. This is because
112 -- in the course of analyzing the context of a compilation, a package
113 -- declaration is first an open scope, and subsequently an element of the
114 -- context. If subunits or child units are present, a parent unit may
115 -- appear under various guises at various times in the compilation.
117 -- When the compilation of the innermost scope is complete, the entities
118 -- defined therein are no longer visible. If the scope is not a package
119 -- declaration, these entities are never visible subsequently, and can be
120 -- removed from visibility chains. If the scope is a package declaration,
121 -- its visible declarations may still be accessible. Therefore the entities
122 -- defined in such a scope are left on the visibility chains, and only
123 -- their visibility (immediately visibility or potential use-visibility)
126 -- The ordering of homonyms on their chain does not necessarily follow
127 -- the order of their corresponding scopes on the scope stack. For
128 -- example, if package P and the enclosing scope both contain entities
129 -- named E, then when compiling the package body the chain for E will
130 -- hold the global entity first, and the local one (corresponding to
131 -- the current inner scope) next. As a result, name resolution routines
132 -- do not assume any relative ordering of the homonym chains, either
133 -- for scope nesting or to order of appearance of context clauses.
135 -- When compiling a child unit, entities in the parent scope are always
136 -- immediately visible. When compiling the body of a child unit, private
137 -- entities in the parent must also be made immediately visible. There
138 -- are separate routines to make the visible and private declarations
139 -- visible at various times (see package Sem_Ch7).
141 -- +--------+ +-----+
142 -- | In use |-------->| EU1 |-------------------------->
143 -- +--------+ +-----+
145 -- +--------+ +-----+ +-----+
146 -- | Stand. |---------------->| ES1 |--------------->| ES2 |--->
147 -- +--------+ +-----+ +-----+
149 -- +---------+ | +-----+
150 -- | with'ed |------------------------------>| EW2 |--->
151 -- +---------+ | +-----+
153 -- +--------+ +-----+ +-----+
154 -- | Scope2 |---------------->| E12 |--------------->| E22 |--->
155 -- +--------+ +-----+ +-----+
157 -- +--------+ +-----+ +-----+
158 -- | Scope1 |---------------->| E11 |--------------->| E12 |--->
159 -- +--------+ +-----+ +-----+
163 -- | | with'ed |----------------------------------------->
167 -- (innermost first) | |
168 -- +----------------------------+
169 -- Names table => | Id1 | | | | Id2 |
170 -- +----------------------------+
172 -- Name resolution must deal with several syntactic forms: simple names,
173 -- qualified names, indexed names, and various forms of calls.
175 -- Each identifier points to an entry in the names table. The resolution
176 -- of a simple name consists in traversing the homonym chain, starting
177 -- from the names table. If an entry is immediately visible, it is the one
178 -- designated by the identifier. If only potentially use-visible entities
179 -- are on the chain, we must verify that they do not hide each other. If
180 -- the entity we find is overloadable, we collect all other overloadable
181 -- entities on the chain as long as they are not hidden.
183 -- To resolve expanded names, we must find the entity at the intersection
184 -- of the entity chain for the scope (the prefix) and the homonym chain
185 -- for the selector. In general, homonym chains will be much shorter than
186 -- entity chains, so it is preferable to start from the names table as
187 -- well. If the entity found is overloadable, we must collect all other
188 -- interpretations that are defined in the scope denoted by the prefix.
190 -- For records, protected types, and tasks, their local entities are
191 -- removed from visibility chains on exit from the corresponding scope.
192 -- From the outside, these entities are always accessed by selected
193 -- notation, and the entity chain for the record type, protected type,
194 -- etc. is traversed sequentially in order to find the designated entity.
196 -- The discriminants of a type and the operations of a protected type or
197 -- task are unchained on exit from the first view of the type, (such as
198 -- a private or incomplete type declaration, or a protected type speci-
199 -- fication) and re-chained when compiling the second view.
201 -- In the case of operators, we do not make operators on derived types
202 -- explicit. As a result, the notation P."+" may denote either a user-
203 -- defined function with name "+", or else an implicit declaration of the
204 -- operator "+" in package P. The resolution of expanded names always
205 -- tries to resolve an operator name as such an implicitly defined entity,
206 -- in addition to looking for explicit declarations.
208 -- All forms of names that denote entities (simple names, expanded names,
209 -- character literals in some cases) have a Entity attribute, which
210 -- identifies the entity denoted by the name.
212 ---------------------
213 -- The Scope Stack --
214 ---------------------
216 -- The Scope stack keeps track of the scopes currently been compiled.
217 -- Every entity that contains declarations (including records) is placed
218 -- on the scope stack while it is being processed, and removed at the end.
219 -- Whenever a non-package scope is exited, the entities defined therein
220 -- are removed from the visibility table, so that entities in outer scopes
221 -- become visible (see previous description). On entry to Sem, the scope
222 -- stack only contains the package Standard. As usual, subunits complicate
223 -- this picture ever so slightly.
225 -- The Rtsfind mechanism can force a call to Semantics while another
226 -- compilation is in progress. The unit retrieved by Rtsfind must be
227 -- compiled in its own context, and has no access to the visibility of
228 -- the unit currently being compiled. The procedures Save_Scope_Stack and
229 -- Restore_Scope_Stack make entities in current open scopes invisible
230 -- before compiling the retrieved unit, and restore the compilation
231 -- environment afterwards.
233 ------------------------
234 -- Compiling subunits --
235 ------------------------
237 -- Subunits must be compiled in the environment of the corresponding stub,
238 -- that is to say with the same visibility into the parent (and its
239 -- context) that is available at the point of the stub declaration, but
240 -- with the additional visibility provided by the context clause of the
241 -- subunit itself. As a result, compilation of a subunit forces compilation
242 -- of the parent (see description in lib-). At the point of the stub
243 -- declaration, Analyze is called recursively to compile the proper body of
244 -- the subunit, but without reinitializing the names table, nor the scope
245 -- stack (i.e. standard is not pushed on the stack). In this fashion the
246 -- context of the subunit is added to the context of the parent, and the
247 -- subunit is compiled in the correct environment. Note that in the course
248 -- of processing the context of a subunit, Standard will appear twice on
249 -- the scope stack: once for the parent of the subunit, and once for the
250 -- unit in the context clause being compiled. However, the two sets of
251 -- entities are not linked by homonym chains, so that the compilation of
252 -- any context unit happens in a fresh visibility environment.
254 -------------------------------
255 -- Processing of USE Clauses --
256 -------------------------------
258 -- Every defining occurrence has a flag indicating if it is potentially use
259 -- visible. Resolution of simple names examines this flag. The processing
260 -- of use clauses consists in setting this flag on all visible entities
261 -- defined in the corresponding package. On exit from the scope of the use
262 -- clause, the corresponding flag must be reset. However, a package may
263 -- appear in several nested use clauses (pathological but legal, alas)
264 -- which forces us to use a slightly more involved scheme:
266 -- a) The defining occurrence for a package holds a flag -In_Use- to
267 -- indicate that it is currently in the scope of a use clause. If a
268 -- redundant use clause is encountered, then the corresponding occurrence
269 -- of the package name is flagged -Redundant_Use-.
271 -- b) On exit from a scope, the use clauses in its declarative part are
272 -- scanned. The visibility flag is reset in all entities declared in
273 -- package named in a use clause, as long as the package is not flagged
274 -- as being in a redundant use clause (in which case the outer use
275 -- clause is still in effect, and the direct visibility of its entities
276 -- must be retained).
278 -- Note that entities are not removed from their homonym chains on exit
279 -- from the package specification. A subsequent use clause does not need
280 -- to rechain the visible entities, but only to establish their direct
283 -----------------------------------
284 -- Handling private declarations --
285 -----------------------------------
287 -- The principle that each entity has a single defining occurrence clashes
288 -- with the presence of two separate definitions for private types: the
289 -- first is the private type declaration, and second is the full type
290 -- declaration. It is important that all references to the type point to
291 -- the same defining occurrence, namely the first one. To enforce the two
292 -- separate views of the entity, the corresponding information is swapped
293 -- between the two declarations. Outside of the package, the defining
294 -- occurrence only contains the private declaration information, while in
295 -- the private part and the body of the package the defining occurrence
296 -- contains the full declaration. To simplify the swap, the defining
297 -- occurrence that currently holds the private declaration points to the
298 -- full declaration. During semantic processing the defining occurrence
299 -- also points to a list of private dependents, that is to say access types
300 -- or composite types whose designated types or component types are
301 -- subtypes or derived types of the private type in question. After the
302 -- full declaration has been seen, the private dependents are updated to
303 -- indicate that they have full definitions.
305 ------------------------------------
306 -- Handling of Undefined Messages --
307 ------------------------------------
309 -- In normal mode, only the first use of an undefined identifier generates
310 -- a message. The table Urefs is used to record error messages that have
311 -- been issued so that second and subsequent ones do not generate further
312 -- messages. However, the second reference causes text to be added to the
313 -- original undefined message noting "(more references follow)". The
314 -- full error list option (-gnatf) forces messages to be generated for
315 -- every reference and disconnects the use of this table.
317 type Uref_Entry is record
319 -- Node for identifier for which original message was posted. The
320 -- Chars field of this identifier is used to detect later references
321 -- to the same identifier.
324 -- Records error message Id of original undefined message. Reset to
325 -- No_Error_Msg after the second occurrence, where it is used to add
326 -- text to the original message as described above.
329 -- Set if the message is not visible rather than undefined
332 -- Records location of error message. Used to make sure that we do
333 -- not consider a, b : undefined as two separate instances, which
334 -- would otherwise happen, since the parser converts this sequence
335 -- to a : undefined; b : undefined.
339 package Urefs is new Table.Table (
340 Table_Component_Type => Uref_Entry,
341 Table_Index_Type => Nat,
342 Table_Low_Bound => 1,
344 Table_Increment => 100,
345 Table_Name => "Urefs");
347 Candidate_Renaming : Entity_Id;
348 -- Holds a candidate interpretation that appears in a subprogram renaming
349 -- declaration and does not match the given specification, but matches at
350 -- least on the first formal. Allows better error message when given
351 -- specification omits defaulted parameters, a common error.
353 -----------------------
354 -- Local Subprograms --
355 -----------------------
357 procedure Analyze_Generic_Renaming
360 -- Common processing for all three kinds of generic renaming declarations.
361 -- Enter new name and indicate that it renames the generic unit.
363 procedure Analyze_Renamed_Character
367 -- Renamed entity is given by a character literal, which must belong
368 -- to the return type of the new entity. Is_Body indicates whether the
369 -- declaration is a renaming_as_body. If the original declaration has
370 -- already been frozen (because of an intervening body, e.g.) the body of
371 -- the function must be built now. The same applies to the following
372 -- various renaming procedures.
374 procedure Analyze_Renamed_Dereference
378 -- Renamed entity is given by an explicit dereference. Prefix must be a
379 -- conformant access_to_subprogram type.
381 procedure Analyze_Renamed_Entry
385 -- If the renamed entity in a subprogram renaming is an entry or protected
386 -- subprogram, build a body for the new entity whose only statement is a
387 -- call to the renamed entity.
389 procedure Analyze_Renamed_Family_Member
393 -- Used when the renamed entity is an indexed component. The prefix must
394 -- denote an entry family.
396 procedure Analyze_Renamed_Primitive_Operation
400 -- If the renamed entity in a subprogram renaming is a primitive operation
401 -- or a class-wide operation in prefix form, save the target object,
402 -- which must be added to the list of actuals in any subsequent call.
403 -- The renaming operation is intrinsic because the compiler must in
404 -- fact generate a wrapper for it (6.3.1 (10 1/2)).
406 function Applicable_Use (Pack_Name : Node_Id) return Boolean;
407 -- Common code to Use_One_Package and Set_Use, to determine whether use
408 -- clause must be processed. Pack_Name is an entity name that references
409 -- the package in question.
411 procedure Attribute_Renaming (N : Node_Id);
412 -- Analyze renaming of attribute as subprogram. The renaming declaration N
413 -- is rewritten as a subprogram body that returns the attribute reference
414 -- applied to the formals of the function.
416 procedure Set_Entity_Or_Discriminal (N : Node_Id; E : Entity_Id);
417 -- Set Entity, with style check if need be. For a discriminant reference,
418 -- replace by the corresponding discriminal, i.e. the parameter of the
419 -- initialization procedure that corresponds to the discriminant.
421 procedure Check_Frozen_Renaming (N : Node_Id; Subp : Entity_Id);
422 -- A renaming_as_body may occur after the entity of the original decla-
423 -- ration has been frozen. In that case, the body of the new entity must
424 -- be built now, because the usual mechanism of building the renamed
425 -- body at the point of freezing will not work. Subp is the subprogram
426 -- for which N provides the Renaming_As_Body.
428 procedure Check_In_Previous_With_Clause
431 -- N is a use_package clause and Nam the package name, or N is a use_type
432 -- clause and Nam is the prefix of the type name. In either case, verify
433 -- that the package is visible at that point in the context: either it
434 -- appears in a previous with_clause, or because it is a fully qualified
435 -- name and the root ancestor appears in a previous with_clause.
437 procedure Check_Library_Unit_Renaming (N : Node_Id; Old_E : Entity_Id);
438 -- Verify that the entity in a renaming declaration that is a library unit
439 -- is itself a library unit and not a nested unit or subunit. Also check
440 -- that if the renaming is a child unit of a generic parent, then the
441 -- renamed unit must also be a child unit of that parent. Finally, verify
442 -- that a renamed generic unit is not an implicit child declared within
443 -- an instance of the parent.
445 procedure Chain_Use_Clause (N : Node_Id);
446 -- Chain use clause onto list of uses clauses headed by First_Use_Clause in
447 -- the proper scope table entry. This is usually the current scope, but it
448 -- will be an inner scope when installing the use clauses of the private
449 -- declarations of a parent unit prior to compiling the private part of a
450 -- child unit. This chain is traversed when installing/removing use clauses
451 -- when compiling a subunit or instantiating a generic body on the fly,
452 -- when it is necessary to save and restore full environments.
454 function Enclosing_Instance return Entity_Id;
455 -- In an instance nested within another one, several semantic checks are
456 -- unnecessary because the legality of the nested instance has been checked
457 -- in the enclosing generic unit. This applies in particular to legality
458 -- checks on actuals for formal subprograms of the inner instance, which
459 -- are checked as subprogram renamings, and may be complicated by confusion
460 -- in private/full views. This function returns the instance enclosing the
461 -- current one if there is such, else it returns Empty.
463 -- If the renaming determines the entity for the default of a formal
464 -- subprogram nested within another instance, choose the innermost
465 -- candidate. This is because if the formal has a box, and we are within
466 -- an enclosing instance where some candidate interpretations are local
467 -- to this enclosing instance, we know that the default was properly
468 -- resolved when analyzing the generic, so we prefer the local
469 -- candidates to those that are external. This is not always the case
470 -- but is a reasonable heuristic on the use of nested generics. The
471 -- proper solution requires a full renaming model.
473 function Has_Implicit_Character_Literal (N : Node_Id) return Boolean;
474 -- Find a type derived from Character or Wide_Character in the prefix of N.
475 -- Used to resolved qualified names whose selector is a character literal.
477 function Has_Private_With (E : Entity_Id) return Boolean;
478 -- Ada 2005 (AI-262): Determines if the current compilation unit has a
479 -- private with on E.
481 procedure Find_Expanded_Name (N : Node_Id);
482 -- The input is a selected component known to be an expanded name. Verify
483 -- legality of selector given the scope denoted by prefix, and change node
484 -- N into a expanded name with a properly set Entity field.
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_Operator (N : Node_Id) return Boolean;
498 -- N is an expanded name whose selector is an operator name (e.g. P."+").
499 -- declarative part contains an implicit declaration of an operator if it
500 -- has a declaration of a type to which one of the predefined operators
501 -- apply. The existence of this routine is an implementation artifact. A
502 -- more straightforward but more space-consuming choice would be to make
503 -- all inherited operators explicit in the symbol table.
505 procedure Inherit_Renamed_Profile (New_S : Entity_Id; Old_S : Entity_Id);
506 -- A subprogram defined by a renaming declaration inherits the parameter
507 -- profile of the renamed entity. The subtypes given in the subprogram
508 -- specification are discarded and replaced with those of the renamed
509 -- subprogram, which are then used to recheck the default values.
511 function Is_Appropriate_For_Record (T : Entity_Id) return Boolean;
512 -- Prefix is appropriate for record if it is of a record type, or an access
515 function Is_Appropriate_For_Entry_Prefix (T : Entity_Id) return Boolean;
516 -- True if it is of a task type, a protected type, or else an access to one
519 procedure Note_Redundant_Use (Clause : Node_Id);
520 -- Mark the name in a use clause as redundant if the corresponding entity
521 -- is already use-visible. Emit a warning if the use clause comes from
522 -- source and the proper warnings are enabled.
524 procedure Premature_Usage (N : Node_Id);
525 -- Diagnose usage of an entity before it is visible
527 procedure Use_One_Package (P : Entity_Id; N : Node_Id);
528 -- Make visible entities declared in package P potentially use-visible
529 -- in the current context. Also used in the analysis of subunits, when
530 -- re-installing use clauses of parent units. N is the use_clause that
531 -- names P (and possibly other packages).
533 procedure Use_One_Type (Id : Node_Id; Installed : Boolean := False);
534 -- Id is the subtype mark from a use type clause. This procedure makes
535 -- the primitive operators of the type potentially use-visible. The
536 -- boolean flag Installed indicates that the clause is being reinstalled
537 -- after previous analysis, and primitive operations are already chained
538 -- on the Used_Operations list of the clause.
540 procedure Write_Info;
541 -- Write debugging information on entities declared in current scope
543 --------------------------------
544 -- Analyze_Exception_Renaming --
545 --------------------------------
547 -- The language only allows a single identifier, but the tree holds an
548 -- identifier list. The parser has already issued an error message if
549 -- there is more than one element in the list.
551 procedure Analyze_Exception_Renaming (N : Node_Id) is
552 Id : constant Entity_Id := Defining_Entity (N);
553 Nam : constant Node_Id := Name (N);
556 Check_SPARK_05_Restriction ("exception renaming is not allowed", N);
561 Set_Ekind (Id, E_Exception);
562 Set_Etype (Id, Standard_Exception_Type);
563 Set_Is_Pure (Id, Is_Pure (Current_Scope));
565 if Is_Entity_Name (Nam)
566 and then Present (Entity (Nam))
567 and then Ekind (Entity (Nam)) = E_Exception
569 if Present (Renamed_Object (Entity (Nam))) then
570 Set_Renamed_Object (Id, Renamed_Object (Entity (Nam)));
572 Set_Renamed_Object (Id, Entity (Nam));
575 -- The exception renaming declaration may become Ghost if it renames
578 Mark_Renaming_As_Ghost (N, Entity (Nam));
580 Error_Msg_N ("invalid exception name in renaming", Nam);
583 -- Implementation-defined aspect specifications can appear in a renaming
584 -- declaration, but not language-defined ones. The call to procedure
585 -- Analyze_Aspect_Specifications will take care of this error check.
587 if Has_Aspects (N) then
588 Analyze_Aspect_Specifications (N, Id);
590 end Analyze_Exception_Renaming;
592 ---------------------------
593 -- Analyze_Expanded_Name --
594 ---------------------------
596 procedure Analyze_Expanded_Name (N : Node_Id) is
598 -- If the entity pointer is already set, this is an internal node, or a
599 -- node that is analyzed more than once, after a tree modification. In
600 -- such a case there is no resolution to perform, just set the type. In
601 -- either case, start by analyzing the prefix.
603 Analyze (Prefix (N));
605 if Present (Entity (N)) then
606 if Is_Type (Entity (N)) then
607 Set_Etype (N, Entity (N));
609 Set_Etype (N, Etype (Entity (N)));
614 Find_Expanded_Name (N);
617 Analyze_Dimension (N);
618 end Analyze_Expanded_Name;
620 ---------------------------------------
621 -- Analyze_Generic_Function_Renaming --
622 ---------------------------------------
624 procedure Analyze_Generic_Function_Renaming (N : Node_Id) is
626 Analyze_Generic_Renaming (N, E_Generic_Function);
627 end Analyze_Generic_Function_Renaming;
629 --------------------------------------
630 -- Analyze_Generic_Package_Renaming --
631 --------------------------------------
633 procedure Analyze_Generic_Package_Renaming (N : Node_Id) is
635 -- Test for the Text_IO special unit case here, since we may be renaming
636 -- one of the subpackages of Text_IO, then join common routine.
638 Check_Text_IO_Special_Unit (Name (N));
640 Analyze_Generic_Renaming (N, E_Generic_Package);
641 end Analyze_Generic_Package_Renaming;
643 ----------------------------------------
644 -- Analyze_Generic_Procedure_Renaming --
645 ----------------------------------------
647 procedure Analyze_Generic_Procedure_Renaming (N : Node_Id) is
649 Analyze_Generic_Renaming (N, E_Generic_Procedure);
650 end Analyze_Generic_Procedure_Renaming;
652 ------------------------------
653 -- Analyze_Generic_Renaming --
654 ------------------------------
656 procedure Analyze_Generic_Renaming
660 New_P : constant Entity_Id := Defining_Entity (N);
663 Inst : Boolean := False;
664 -- Prevent junk warning
667 if Name (N) = Error then
671 Check_SPARK_05_Restriction ("generic renaming is not allowed", N);
673 Generate_Definition (New_P);
675 if Current_Scope /= Standard_Standard then
676 Set_Is_Pure (New_P, Is_Pure (Current_Scope));
679 if Nkind (Name (N)) = N_Selected_Component then
680 Check_Generic_Child_Unit (Name (N), Inst);
685 if not Is_Entity_Name (Name (N)) then
686 Error_Msg_N ("expect entity name in renaming declaration", Name (N));
689 Old_P := Entity (Name (N));
693 Set_Ekind (New_P, K);
695 if Etype (Old_P) = Any_Type then
698 elsif Ekind (Old_P) /= K then
699 Error_Msg_N ("invalid generic unit name", Name (N));
702 if Present (Renamed_Object (Old_P)) then
703 Set_Renamed_Object (New_P, Renamed_Object (Old_P));
705 Set_Renamed_Object (New_P, Old_P);
708 Set_Is_Pure (New_P, Is_Pure (Old_P));
709 Set_Is_Preelaborated (New_P, Is_Preelaborated (Old_P));
711 Set_Etype (New_P, Etype (Old_P));
712 Set_Has_Completion (New_P);
714 -- The generic renaming declaration may become Ghost if it renames a
717 Mark_Renaming_As_Ghost (N, Old_P);
719 if In_Open_Scopes (Old_P) then
720 Error_Msg_N ("within its scope, generic denotes its instance", N);
723 -- For subprograms, propagate the Intrinsic flag, to allow, e.g.
724 -- renamings and subsequent instantiations of Unchecked_Conversion.
726 if Ekind_In (Old_P, E_Generic_Function, E_Generic_Procedure) then
727 Set_Is_Intrinsic_Subprogram
728 (New_P, Is_Intrinsic_Subprogram (Old_P));
731 Check_Library_Unit_Renaming (N, Old_P);
734 -- Implementation-defined aspect specifications can appear in a renaming
735 -- declaration, but not language-defined ones. The call to procedure
736 -- Analyze_Aspect_Specifications will take care of this error check.
738 if Has_Aspects (N) then
739 Analyze_Aspect_Specifications (N, New_P);
741 end Analyze_Generic_Renaming;
743 -----------------------------
744 -- Analyze_Object_Renaming --
745 -----------------------------
747 procedure Analyze_Object_Renaming (N : Node_Id) is
748 Id : constant Entity_Id := Defining_Identifier (N);
749 Loc : constant Source_Ptr := Sloc (N);
750 Nam : constant Node_Id := Name (N);
755 procedure Check_Constrained_Object;
756 -- If the nominal type is unconstrained but the renamed object is
757 -- constrained, as can happen with renaming an explicit dereference or
758 -- a function return, build a constrained subtype from the object. If
759 -- the renaming is for a formal in an accept statement, the analysis
760 -- has already established its actual subtype. This is only relevant
761 -- if the renamed object is an explicit dereference.
763 function In_Generic_Scope (E : Entity_Id) return Boolean;
764 -- Determine whether entity E is inside a generic cope
766 ------------------------------
767 -- Check_Constrained_Object --
768 ------------------------------
770 procedure Check_Constrained_Object is
771 Typ : constant Entity_Id := Etype (Nam);
775 if Nkind_In (Nam, N_Function_Call, N_Explicit_Dereference)
776 and then Is_Composite_Type (Etype (Nam))
777 and then not Is_Constrained (Etype (Nam))
778 and then not Has_Unknown_Discriminants (Etype (Nam))
779 and then Expander_Active
781 -- If Actual_Subtype is already set, nothing to do
783 if Ekind_In (Id, E_Variable, E_Constant)
784 and then Present (Actual_Subtype (Id))
788 -- A renaming of an unchecked union has no actual subtype
790 elsif Is_Unchecked_Union (Typ) then
793 -- If a record is limited its size is invariant. This is the case
794 -- in particular with record types with an access discirminant
795 -- that are used in iterators. This is an optimization, but it
796 -- also prevents typing anomalies when the prefix is further
797 -- expanded. Limited types with discriminants are included.
799 elsif Is_Limited_Record (Typ)
801 (Ekind (Typ) = E_Limited_Private_Type
802 and then Has_Discriminants (Typ)
803 and then Is_Access_Type (Etype (First_Discriminant (Typ))))
808 Subt := Make_Temporary (Loc, 'T');
809 Remove_Side_Effects (Nam);
811 Make_Subtype_Declaration (Loc,
812 Defining_Identifier => Subt,
813 Subtype_Indication =>
814 Make_Subtype_From_Expr (Nam, Typ)));
815 Rewrite (Subtype_Mark (N), New_Occurrence_Of (Subt, Loc));
816 Set_Etype (Nam, Subt);
818 -- Freeze subtype at once, to prevent order of elaboration
819 -- issues in the backend. The renamed object exists, so its
820 -- type is already frozen in any case.
822 Freeze_Before (N, Subt);
825 end Check_Constrained_Object;
827 ----------------------
828 -- In_Generic_Scope --
829 ----------------------
831 function In_Generic_Scope (E : Entity_Id) return Boolean is
836 while Present (S) and then S /= Standard_Standard loop
837 if Is_Generic_Unit (S) then
845 end In_Generic_Scope;
847 -- Start of processing for Analyze_Object_Renaming
854 Check_SPARK_05_Restriction ("object renaming is not allowed", N);
856 Set_Is_Pure (Id, Is_Pure (Current_Scope));
859 -- The renaming of a component that depends on a discriminant requires
860 -- an actual subtype, because in subsequent use of the object Gigi will
861 -- be unable to locate the actual bounds. This explicit step is required
862 -- when the renaming is generated in removing side effects of an
863 -- already-analyzed expression.
865 if Nkind (Nam) = N_Selected_Component and then Analyzed (Nam) then
867 Dec := Build_Actual_Subtype_Of_Component (Etype (Nam), Nam);
869 if Present (Dec) then
870 Insert_Action (N, Dec);
871 T := Defining_Identifier (Dec);
875 -- Complete analysis of the subtype mark in any case, for ASIS use
877 if Present (Subtype_Mark (N)) then
878 Find_Type (Subtype_Mark (N));
881 elsif Present (Subtype_Mark (N)) then
882 Find_Type (Subtype_Mark (N));
883 T := Entity (Subtype_Mark (N));
886 -- Reject renamings of conversions unless the type is tagged, or
887 -- the conversion is implicit (which can occur for cases of anonymous
888 -- access types in Ada 2012).
890 if Nkind (Nam) = N_Type_Conversion
891 and then Comes_From_Source (Nam)
892 and then not Is_Tagged_Type (T)
895 ("renaming of conversion only allowed for tagged types", Nam);
900 -- If the renamed object is a function call of a limited type,
901 -- the expansion of the renaming is complicated by the presence
902 -- of various temporaries and subtypes that capture constraints
903 -- of the renamed object. Rewrite node as an object declaration,
904 -- whose expansion is simpler. Given that the object is limited
905 -- there is no copy involved and no performance hit.
907 if Nkind (Nam) = N_Function_Call
908 and then Is_Limited_View (Etype (Nam))
909 and then not Is_Constrained (Etype (Nam))
910 and then Comes_From_Source (N)
913 Set_Ekind (Id, E_Constant);
915 Make_Object_Declaration (Loc,
916 Defining_Identifier => Id,
917 Constant_Present => True,
918 Object_Definition => New_Occurrence_Of (Etype (Nam), Loc),
919 Expression => Relocate_Node (Nam)));
923 -- Ada 2012 (AI05-149): Reject renaming of an anonymous access object
924 -- when renaming declaration has a named access type. The Ada 2012
925 -- coverage rules allow an anonymous access type in the context of
926 -- an expected named general access type, but the renaming rules
927 -- require the types to be the same. (An exception is when the type
928 -- of the renaming is also an anonymous access type, which can only
929 -- happen due to a renaming created by the expander.)
931 if Nkind (Nam) = N_Type_Conversion
932 and then not Comes_From_Source (Nam)
933 and then Ekind (Etype (Expression (Nam))) = E_Anonymous_Access_Type
934 and then Ekind (T) /= E_Anonymous_Access_Type
936 Wrong_Type (Expression (Nam), T); -- Should we give better error???
939 -- Check that a class-wide object is not being renamed as an object
940 -- of a specific type. The test for access types is needed to exclude
941 -- cases where the renamed object is a dynamically tagged access
942 -- result, such as occurs in certain expansions.
944 if Is_Tagged_Type (T) then
945 Check_Dynamically_Tagged_Expression
951 -- Ada 2005 (AI-230/AI-254): Access renaming
953 else pragma Assert (Present (Access_Definition (N)));
954 T := Access_Definition
956 N => Access_Definition (N));
960 -- Ada 2005 AI05-105: if the declaration has an anonymous access
961 -- type, the renamed object must also have an anonymous type, and
962 -- this is a name resolution rule. This was implicit in the last part
963 -- of the first sentence in 8.5.1(3/2), and is made explicit by this
966 if not Is_Overloaded (Nam) then
967 if Ekind (Etype (Nam)) /= Ekind (T) then
969 ("expect anonymous access type in object renaming", N);
976 Typ : Entity_Id := Empty;
977 Seen : Boolean := False;
980 Get_First_Interp (Nam, I, It);
981 while Present (It.Typ) loop
983 -- Renaming is ambiguous if more than one candidate
984 -- interpretation is type-conformant with the context.
986 if Ekind (It.Typ) = Ekind (T) then
987 if Ekind (T) = E_Anonymous_Access_Subprogram_Type
990 (Designated_Type (T), Designated_Type (It.Typ))
996 ("ambiguous expression in renaming", Nam);
999 elsif Ekind (T) = E_Anonymous_Access_Type
1001 Covers (Designated_Type (T), Designated_Type (It.Typ))
1007 ("ambiguous expression in renaming", Nam);
1011 if Covers (T, It.Typ) then
1013 Set_Etype (Nam, Typ);
1014 Set_Is_Overloaded (Nam, False);
1018 Get_Next_Interp (I, It);
1025 -- Ada 2005 (AI-231): In the case where the type is defined by an
1026 -- access_definition, the renamed entity shall be of an access-to-
1027 -- constant type if and only if the access_definition defines an
1028 -- access-to-constant type. ARM 8.5.1(4)
1030 if Constant_Present (Access_Definition (N))
1031 and then not Is_Access_Constant (Etype (Nam))
1033 Error_Msg_N ("(Ada 2005): the renamed object is not "
1034 & "access-to-constant (RM 8.5.1(6))", N);
1036 elsif not Constant_Present (Access_Definition (N))
1037 and then Is_Access_Constant (Etype (Nam))
1039 Error_Msg_N ("(Ada 2005): the renamed object is not "
1040 & "access-to-variable (RM 8.5.1(6))", N);
1043 if Is_Access_Subprogram_Type (Etype (Nam)) then
1044 Check_Subtype_Conformant
1045 (Designated_Type (T), Designated_Type (Etype (Nam)));
1047 elsif not Subtypes_Statically_Match
1048 (Designated_Type (T),
1049 Available_View (Designated_Type (Etype (Nam))))
1052 ("subtype of renamed object does not statically match", N);
1056 -- Special processing for renaming function return object. Some errors
1057 -- and warnings are produced only for calls that come from source.
1059 if Nkind (Nam) = N_Function_Call then
1062 -- Usage is illegal in Ada 83, but renamings are also introduced
1063 -- during expansion, and error does not apply to those.
1066 if Comes_From_Source (N) then
1068 ("(Ada 83) cannot rename function return object", Nam);
1071 -- In Ada 95, warn for odd case of renaming parameterless function
1072 -- call if this is not a limited type (where this is useful).
1075 if Warn_On_Object_Renames_Function
1076 and then No (Parameter_Associations (Nam))
1077 and then not Is_Limited_Type (Etype (Nam))
1078 and then Comes_From_Source (Nam)
1081 ("renaming function result object is suspicious?R?", Nam);
1083 ("\function & will be called only once?R?", Nam,
1084 Entity (Name (Nam)));
1085 Error_Msg_N -- CODEFIX
1086 ("\suggest using an initialized constant "
1087 & "object instead?R?", Nam);
1093 Check_Constrained_Object;
1095 -- An object renaming requires an exact match of the type. Class-wide
1096 -- matching is not allowed.
1098 if Is_Class_Wide_Type (T)
1099 and then Base_Type (Etype (Nam)) /= Base_Type (T)
1101 Wrong_Type (Nam, T);
1106 -- Ada 2005 (AI-326): Handle wrong use of incomplete type
1108 if Nkind (Nam) = N_Explicit_Dereference
1109 and then Ekind (Etype (T2)) = E_Incomplete_Type
1111 Error_Msg_NE ("invalid use of incomplete type&", Id, T2);
1114 elsif Ekind (Etype (T)) = E_Incomplete_Type then
1115 Error_Msg_NE ("invalid use of incomplete type&", Id, T);
1119 -- Ada 2005 (AI-327)
1121 if Ada_Version >= Ada_2005
1122 and then Nkind (Nam) = N_Attribute_Reference
1123 and then Attribute_Name (Nam) = Name_Priority
1127 elsif Ada_Version >= Ada_2005 and then Nkind (Nam) in N_Has_Entity then
1130 Nam_Ent : Entity_Id;
1133 if Nkind (Nam) = N_Attribute_Reference then
1134 Nam_Ent := Entity (Prefix (Nam));
1136 Nam_Ent := Entity (Nam);
1139 Nam_Decl := Parent (Nam_Ent);
1141 if Has_Null_Exclusion (N)
1142 and then not Has_Null_Exclusion (Nam_Decl)
1144 -- Ada 2005 (AI-423): If the object name denotes a generic
1145 -- formal object of a generic unit G, and the object renaming
1146 -- declaration occurs within the body of G or within the body
1147 -- of a generic unit declared within the declarative region
1148 -- of G, then the declaration of the formal object of G must
1149 -- have a null exclusion or a null-excluding subtype.
1151 if Is_Formal_Object (Nam_Ent)
1152 and then In_Generic_Scope (Id)
1154 if not Can_Never_Be_Null (Etype (Nam_Ent)) then
1156 ("renamed formal does not exclude `NULL` "
1157 & "(RM 8.5.1(4.6/2))", N);
1159 elsif In_Package_Body (Scope (Id)) then
1161 ("formal object does not have a null exclusion"
1162 & "(RM 8.5.1(4.6/2))", N);
1165 -- Ada 2005 (AI-423): Otherwise, the subtype of the object name
1166 -- shall exclude null.
1168 elsif not Can_Never_Be_Null (Etype (Nam_Ent)) then
1170 ("renamed object does not exclude `NULL` "
1171 & "(RM 8.5.1(4.6/2))", N);
1173 -- An instance is illegal if it contains a renaming that
1174 -- excludes null, and the actual does not. The renaming
1175 -- declaration has already indicated that the declaration
1176 -- of the renamed actual in the instance will raise
1177 -- constraint_error.
1179 elsif Nkind (Nam_Decl) = N_Object_Declaration
1180 and then In_Instance
1182 Present (Corresponding_Generic_Association (Nam_Decl))
1183 and then Nkind (Expression (Nam_Decl)) =
1184 N_Raise_Constraint_Error
1187 ("renamed actual does not exclude `NULL` "
1188 & "(RM 8.5.1(4.6/2))", N);
1190 -- Finally, if there is a null exclusion, the subtype mark
1191 -- must not be null-excluding.
1193 elsif No (Access_Definition (N))
1194 and then Can_Never_Be_Null (T)
1197 ("`NOT NULL` not allowed (& already excludes null)",
1202 elsif Can_Never_Be_Null (T)
1203 and then not Can_Never_Be_Null (Etype (Nam_Ent))
1206 ("renamed object does not exclude `NULL` "
1207 & "(RM 8.5.1(4.6/2))", N);
1209 elsif Has_Null_Exclusion (N)
1210 and then No (Access_Definition (N))
1211 and then Can_Never_Be_Null (T)
1214 ("`NOT NULL` not allowed (& already excludes null)", N, T);
1219 -- Set the Ekind of the entity, unless it has been set already, as is
1220 -- the case for the iteration object over a container with no variable
1221 -- indexing. In that case it's been marked as a constant, and we do not
1222 -- want to change it to a variable.
1224 if Ekind (Id) /= E_Constant then
1225 Set_Ekind (Id, E_Variable);
1228 -- Initialize the object size and alignment. Note that we used to call
1229 -- Init_Size_Align here, but that's wrong for objects which have only
1230 -- an Esize, not an RM_Size field.
1232 Init_Object_Size_Align (Id);
1234 if T = Any_Type or else Etype (Nam) = Any_Type then
1237 -- Verify that the renamed entity is an object or a function call. It
1238 -- may have been rewritten in several ways.
1240 elsif Is_Object_Reference (Nam) then
1241 if Comes_From_Source (N) then
1242 if Is_Dependent_Component_Of_Mutable_Object (Nam) then
1244 ("illegal renaming of discriminant-dependent component", Nam);
1247 -- If the renaming comes from source and the renamed object is a
1248 -- dereference, then mark the prefix as needing debug information,
1249 -- since it might have been rewritten hence internally generated
1250 -- and Debug_Renaming_Declaration will link the renaming to it.
1252 if Nkind (Nam) = N_Explicit_Dereference
1253 and then Is_Entity_Name (Prefix (Nam))
1255 Set_Debug_Info_Needed (Entity (Prefix (Nam)));
1259 -- A static function call may have been folded into a literal
1261 elsif Nkind (Original_Node (Nam)) = N_Function_Call
1263 -- When expansion is disabled, attribute reference is not rewritten
1264 -- as function call. Otherwise it may be rewritten as a conversion,
1265 -- so check original node.
1267 or else (Nkind (Original_Node (Nam)) = N_Attribute_Reference
1268 and then Is_Function_Attribute_Name
1269 (Attribute_Name (Original_Node (Nam))))
1271 -- Weird but legal, equivalent to renaming a function call. Illegal
1272 -- if the literal is the result of constant-folding an attribute
1273 -- reference that is not a function.
1275 or else (Is_Entity_Name (Nam)
1276 and then Ekind (Entity (Nam)) = E_Enumeration_Literal
1278 Nkind (Original_Node (Nam)) /= N_Attribute_Reference)
1280 or else (Nkind (Nam) = N_Type_Conversion
1281 and then Is_Tagged_Type (Entity (Subtype_Mark (Nam))))
1285 elsif Nkind (Nam) = N_Type_Conversion then
1287 ("renaming of conversion only allowed for tagged types", Nam);
1289 -- Ada 2005 (AI-327)
1291 elsif Ada_Version >= Ada_2005
1292 and then Nkind (Nam) = N_Attribute_Reference
1293 and then Attribute_Name (Nam) = Name_Priority
1297 -- Allow internally generated x'Ref resulting in N_Reference node
1299 elsif Nkind (Nam) = N_Reference then
1303 Error_Msg_N ("expect object name in renaming", Nam);
1308 if not Is_Variable (Nam) then
1309 Set_Ekind (Id, E_Constant);
1310 Set_Never_Set_In_Source (Id, True);
1311 Set_Is_True_Constant (Id, True);
1314 -- The object renaming declaration may become Ghost if it renames a
1317 if Is_Entity_Name (Nam) then
1318 Mark_Renaming_As_Ghost (N, Entity (Nam));
1321 -- The entity of the renaming declaration needs to reflect whether the
1322 -- renamed object is volatile. Is_Volatile is set if the renamed object
1323 -- is volatile in the RM legality sense.
1325 Set_Is_Volatile (Id, Is_Volatile_Object (Nam));
1327 -- Also copy settings of Atomic/Independent/Volatile_Full_Access
1329 if Is_Entity_Name (Nam) then
1330 Set_Is_Atomic (Id, Is_Atomic (Entity (Nam)));
1331 Set_Is_Independent (Id, Is_Independent (Entity (Nam)));
1332 Set_Is_Volatile_Full_Access (Id,
1333 Is_Volatile_Full_Access (Entity (Nam)));
1336 -- Treat as volatile if we just set the Volatile flag
1340 -- Or if we are renaming an entity which was marked this way
1342 -- Are there more cases, e.g. X(J) where X is Treat_As_Volatile ???
1344 or else (Is_Entity_Name (Nam)
1345 and then Treat_As_Volatile (Entity (Nam)))
1347 Set_Treat_As_Volatile (Id, True);
1350 -- Now make the link to the renamed object
1352 Set_Renamed_Object (Id, Nam);
1354 -- Implementation-defined aspect specifications can appear in a renaming
1355 -- declaration, but not language-defined ones. The call to procedure
1356 -- Analyze_Aspect_Specifications will take care of this error check.
1358 if Has_Aspects (N) then
1359 Analyze_Aspect_Specifications (N, Id);
1362 -- Deal with dimensions
1364 Analyze_Dimension (N);
1365 end Analyze_Object_Renaming;
1367 ------------------------------
1368 -- Analyze_Package_Renaming --
1369 ------------------------------
1371 procedure Analyze_Package_Renaming (N : Node_Id) is
1372 New_P : constant Entity_Id := Defining_Entity (N);
1377 if Name (N) = Error then
1381 -- Check for Text_IO special unit (we may be renaming a Text_IO child)
1383 Check_Text_IO_Special_Unit (Name (N));
1385 if Current_Scope /= Standard_Standard then
1386 Set_Is_Pure (New_P, Is_Pure (Current_Scope));
1392 if Is_Entity_Name (Name (N)) then
1393 Old_P := Entity (Name (N));
1398 if Etype (Old_P) = Any_Type then
1399 Error_Msg_N ("expect package name in renaming", Name (N));
1401 elsif Ekind (Old_P) /= E_Package
1402 and then not (Ekind (Old_P) = E_Generic_Package
1403 and then In_Open_Scopes (Old_P))
1405 if Ekind (Old_P) = E_Generic_Package then
1407 ("generic package cannot be renamed as a package", Name (N));
1409 Error_Msg_Sloc := Sloc (Old_P);
1411 ("expect package name in renaming, found& declared#",
1415 -- Set basic attributes to minimize cascaded errors
1417 Set_Ekind (New_P, E_Package);
1418 Set_Etype (New_P, Standard_Void_Type);
1420 -- Here for OK package renaming
1423 -- Entities in the old package are accessible through the renaming
1424 -- entity. The simplest implementation is to have both packages share
1427 Set_Ekind (New_P, E_Package);
1428 Set_Etype (New_P, Standard_Void_Type);
1430 if Present (Renamed_Object (Old_P)) then
1431 Set_Renamed_Object (New_P, Renamed_Object (Old_P));
1433 Set_Renamed_Object (New_P, Old_P);
1436 Set_Has_Completion (New_P);
1438 Set_First_Entity (New_P, First_Entity (Old_P));
1439 Set_Last_Entity (New_P, Last_Entity (Old_P));
1440 Set_First_Private_Entity (New_P, First_Private_Entity (Old_P));
1441 Check_Library_Unit_Renaming (N, Old_P);
1442 Generate_Reference (Old_P, Name (N));
1444 -- The package renaming declaration may become Ghost if it renames a
1447 Mark_Renaming_As_Ghost (N, Old_P);
1449 -- If the renaming is in the visible part of a package, then we set
1450 -- Renamed_In_Spec for the renamed package, to prevent giving
1451 -- warnings about no entities referenced. Such a warning would be
1452 -- overenthusiastic, since clients can see entities in the renamed
1453 -- package via the visible package renaming.
1456 Ent : constant Entity_Id := Cunit_Entity (Current_Sem_Unit);
1458 if Ekind (Ent) = E_Package
1459 and then not In_Private_Part (Ent)
1460 and then In_Extended_Main_Source_Unit (N)
1461 and then Ekind (Old_P) = E_Package
1463 Set_Renamed_In_Spec (Old_P);
1467 -- If this is the renaming declaration of a package instantiation
1468 -- within itself, it is the declaration that ends the list of actuals
1469 -- for the instantiation. At this point, the subtypes that rename
1470 -- the actuals are flagged as generic, to avoid spurious ambiguities
1471 -- if the actuals for two distinct formals happen to coincide. If
1472 -- the actual is a private type, the subtype has a private completion
1473 -- that is flagged in the same fashion.
1475 -- Resolution is identical to what is was in the original generic.
1476 -- On exit from the generic instance, these are turned into regular
1477 -- subtypes again, so they are compatible with types in their class.
1479 if not Is_Generic_Instance (Old_P) then
1482 Spec := Specification (Unit_Declaration_Node (Old_P));
1485 if Nkind (Spec) = N_Package_Specification
1486 and then Present (Generic_Parent (Spec))
1487 and then Old_P = Current_Scope
1488 and then Chars (New_P) = Chars (Generic_Parent (Spec))
1494 E := First_Entity (Old_P);
1495 while Present (E) and then E /= New_P loop
1497 and then Nkind (Parent (E)) = N_Subtype_Declaration
1499 Set_Is_Generic_Actual_Type (E);
1501 if Is_Private_Type (E)
1502 and then Present (Full_View (E))
1504 Set_Is_Generic_Actual_Type (Full_View (E));
1514 -- Implementation-defined aspect specifications can appear in a renaming
1515 -- declaration, but not language-defined ones. The call to procedure
1516 -- Analyze_Aspect_Specifications will take care of this error check.
1518 if Has_Aspects (N) then
1519 Analyze_Aspect_Specifications (N, New_P);
1521 end Analyze_Package_Renaming;
1523 -------------------------------
1524 -- Analyze_Renamed_Character --
1525 -------------------------------
1527 procedure Analyze_Renamed_Character
1532 C : constant Node_Id := Name (N);
1535 if Ekind (New_S) = E_Function then
1536 Resolve (C, Etype (New_S));
1539 Check_Frozen_Renaming (N, New_S);
1543 Error_Msg_N ("character literal can only be renamed as function", N);
1545 end Analyze_Renamed_Character;
1547 ---------------------------------
1548 -- Analyze_Renamed_Dereference --
1549 ---------------------------------
1551 procedure Analyze_Renamed_Dereference
1556 Nam : constant Node_Id := Name (N);
1557 P : constant Node_Id := Prefix (Nam);
1563 if not Is_Overloaded (P) then
1564 if Ekind (Etype (Nam)) /= E_Subprogram_Type
1565 or else not Type_Conformant (Etype (Nam), New_S)
1567 Error_Msg_N ("designated type does not match specification", P);
1576 Get_First_Interp (Nam, Ind, It);
1578 while Present (It.Nam) loop
1580 if Ekind (It.Nam) = E_Subprogram_Type
1581 and then Type_Conformant (It.Nam, New_S)
1583 if Typ /= Any_Id then
1584 Error_Msg_N ("ambiguous renaming", P);
1591 Get_Next_Interp (Ind, It);
1594 if Typ = Any_Type then
1595 Error_Msg_N ("designated type does not match specification", P);
1600 Check_Frozen_Renaming (N, New_S);
1604 end Analyze_Renamed_Dereference;
1606 ---------------------------
1607 -- Analyze_Renamed_Entry --
1608 ---------------------------
1610 procedure Analyze_Renamed_Entry
1615 Nam : constant Node_Id := Name (N);
1616 Sel : constant Node_Id := Selector_Name (Nam);
1617 Is_Actual : constant Boolean := Present (Corresponding_Formal_Spec (N));
1621 if Entity (Sel) = Any_Id then
1623 -- Selector is undefined on prefix. Error emitted already
1625 Set_Has_Completion (New_S);
1629 -- Otherwise find renamed entity and build body of New_S as a call to it
1631 Old_S := Find_Renamed_Entity (N, Selector_Name (Nam), New_S);
1633 if Old_S = Any_Id then
1634 Error_Msg_N (" no subprogram or entry matches specification", N);
1637 Check_Subtype_Conformant (New_S, Old_S, N);
1638 Generate_Reference (New_S, Defining_Entity (N), 'b');
1639 Style.Check_Identifier (Defining_Entity (N), New_S);
1642 -- Only mode conformance required for a renaming_as_declaration
1644 Check_Mode_Conformant (New_S, Old_S, N);
1647 Inherit_Renamed_Profile (New_S, Old_S);
1649 -- The prefix can be an arbitrary expression that yields a task or
1650 -- protected object, so it must be resolved.
1652 Resolve (Prefix (Nam), Scope (Old_S));
1655 Set_Convention (New_S, Convention (Old_S));
1656 Set_Has_Completion (New_S, Inside_A_Generic);
1658 -- AI05-0225: If the renamed entity is a procedure or entry of a
1659 -- protected object, the target object must be a variable.
1661 if Ekind (Scope (Old_S)) in Protected_Kind
1662 and then Ekind (New_S) = E_Procedure
1663 and then not Is_Variable (Prefix (Nam))
1667 ("target object of protected operation used as actual for "
1668 & "formal procedure must be a variable", Nam);
1671 ("target object of protected operation renamed as procedure, "
1672 & "must be a variable", Nam);
1677 Check_Frozen_Renaming (N, New_S);
1679 end Analyze_Renamed_Entry;
1681 -----------------------------------
1682 -- Analyze_Renamed_Family_Member --
1683 -----------------------------------
1685 procedure Analyze_Renamed_Family_Member
1690 Nam : constant Node_Id := Name (N);
1691 P : constant Node_Id := Prefix (Nam);
1695 if (Is_Entity_Name (P) and then Ekind (Entity (P)) = E_Entry_Family)
1696 or else (Nkind (P) = N_Selected_Component
1697 and then Ekind (Entity (Selector_Name (P))) = E_Entry_Family)
1699 if Is_Entity_Name (P) then
1700 Old_S := Entity (P);
1702 Old_S := Entity (Selector_Name (P));
1705 if not Entity_Matches_Spec (Old_S, New_S) then
1706 Error_Msg_N ("entry family does not match specification", N);
1709 Check_Subtype_Conformant (New_S, Old_S, N);
1710 Generate_Reference (New_S, Defining_Entity (N), 'b');
1711 Style.Check_Identifier (Defining_Entity (N), New_S);
1715 Error_Msg_N ("no entry family matches specification", N);
1718 Set_Has_Completion (New_S, Inside_A_Generic);
1721 Check_Frozen_Renaming (N, New_S);
1723 end Analyze_Renamed_Family_Member;
1725 -----------------------------------------
1726 -- Analyze_Renamed_Primitive_Operation --
1727 -----------------------------------------
1729 procedure Analyze_Renamed_Primitive_Operation
1738 Ctyp : Conformance_Type) return Boolean;
1739 -- Verify that the signatures of the renamed entity and the new entity
1740 -- match. The first formal of the renamed entity is skipped because it
1741 -- is the target object in any subsequent call.
1749 Ctyp : Conformance_Type) return Boolean
1755 if Ekind (Subp) /= Ekind (New_S) then
1759 Old_F := Next_Formal (First_Formal (Subp));
1760 New_F := First_Formal (New_S);
1761 while Present (Old_F) and then Present (New_F) loop
1762 if not Conforming_Types (Etype (Old_F), Etype (New_F), Ctyp) then
1766 if Ctyp >= Mode_Conformant
1767 and then Ekind (Old_F) /= Ekind (New_F)
1772 Next_Formal (New_F);
1773 Next_Formal (Old_F);
1779 -- Start of processing for Analyze_Renamed_Primitive_Operation
1782 if not Is_Overloaded (Selector_Name (Name (N))) then
1783 Old_S := Entity (Selector_Name (Name (N)));
1785 if not Conforms (Old_S, Type_Conformant) then
1790 -- Find the operation that matches the given signature
1798 Get_First_Interp (Selector_Name (Name (N)), Ind, It);
1800 while Present (It.Nam) loop
1801 if Conforms (It.Nam, Type_Conformant) then
1805 Get_Next_Interp (Ind, It);
1810 if Old_S = Any_Id then
1811 Error_Msg_N (" no subprogram or entry matches specification", N);
1815 if not Conforms (Old_S, Subtype_Conformant) then
1816 Error_Msg_N ("subtype conformance error in renaming", N);
1819 Generate_Reference (New_S, Defining_Entity (N), 'b');
1820 Style.Check_Identifier (Defining_Entity (N), New_S);
1823 -- Only mode conformance required for a renaming_as_declaration
1825 if not Conforms (Old_S, Mode_Conformant) then
1826 Error_Msg_N ("mode conformance error in renaming", N);
1829 -- Enforce the rule given in (RM 6.3.1 (10.1/2)): a prefixed
1830 -- view of a subprogram is intrinsic, because the compiler has
1831 -- to generate a wrapper for any call to it. If the name in a
1832 -- subprogram renaming is a prefixed view, the entity is thus
1833 -- intrinsic, and 'Access cannot be applied to it.
1835 Set_Convention (New_S, Convention_Intrinsic);
1838 -- Inherit_Renamed_Profile (New_S, Old_S);
1840 -- The prefix can be an arbitrary expression that yields an
1841 -- object, so it must be resolved.
1843 Resolve (Prefix (Name (N)));
1845 end Analyze_Renamed_Primitive_Operation;
1847 ---------------------------------
1848 -- Analyze_Subprogram_Renaming --
1849 ---------------------------------
1851 procedure Analyze_Subprogram_Renaming (N : Node_Id) is
1852 Formal_Spec : constant Entity_Id := Corresponding_Formal_Spec (N);
1853 Is_Actual : constant Boolean := Present (Formal_Spec);
1854 Nam : constant Node_Id := Name (N);
1855 Save_AV : constant Ada_Version_Type := Ada_Version;
1856 Save_AVP : constant Node_Id := Ada_Version_Pragma;
1857 Save_AV_Exp : constant Ada_Version_Type := Ada_Version_Explicit;
1858 Spec : constant Node_Id := Specification (N);
1860 Old_S : Entity_Id := Empty;
1861 Rename_Spec : Entity_Id;
1863 procedure Build_Class_Wide_Wrapper
1864 (Ren_Id : out Entity_Id;
1865 Wrap_Id : out Entity_Id);
1866 -- Ada 2012 (AI05-0071): A generic/instance scenario involving a formal
1867 -- type with unknown discriminants and a generic primitive operation of
1868 -- the said type with a box require special processing when the actual
1869 -- is a class-wide type:
1872 -- type Formal_Typ (<>) is private;
1873 -- with procedure Prim_Op (Param : Formal_Typ) is <>;
1874 -- package Gen is ...
1876 -- package Inst is new Gen (Actual_Typ'Class);
1878 -- In this case the general renaming mechanism used in the prologue of
1879 -- an instance no longer applies:
1881 -- procedure Prim_Op (Param : Formal_Typ) renames Prim_Op;
1883 -- The above is replaced the following wrapper/renaming combination:
1885 -- procedure Wrapper (Param : Formal_Typ) is -- wrapper
1887 -- Prim_Op (Param); -- primitive
1890 -- procedure Prim_Op (Param : Formal_Typ) renames Wrapper;
1892 -- This transformation applies only if there is no explicit visible
1893 -- class-wide operation at the point of the instantiation. Ren_Id is
1894 -- the entity of the renaming declaration. Wrap_Id is the entity of
1895 -- the generated class-wide wrapper (or Any_Id).
1897 procedure Check_Null_Exclusion
1900 -- Ada 2005 (AI-423): Given renaming Ren of subprogram Sub, check the
1901 -- following AI rules:
1903 -- If Ren is a renaming of a formal subprogram and one of its
1904 -- parameters has a null exclusion, then the corresponding formal
1905 -- in Sub must also have one. Otherwise the subtype of the Sub's
1906 -- formal parameter must exclude null.
1908 -- If Ren is a renaming of a formal function and its return
1909 -- profile has a null exclusion, then Sub's return profile must
1910 -- have one. Otherwise the subtype of Sub's return profile must
1913 procedure Freeze_Actual_Profile;
1914 -- In Ada 2012, enforce the freezing rule concerning formal incomplete
1915 -- types: a callable entity freezes its profile, unless it has an
1916 -- incomplete untagged formal (RM 13.14(10.2/3)).
1918 function Has_Class_Wide_Actual return Boolean;
1919 -- Ada 2012 (AI05-071, AI05-0131): True if N is the renaming for a
1920 -- defaulted formal subprogram where the actual for the controlling
1921 -- formal type is class-wide.
1923 function Original_Subprogram (Subp : Entity_Id) return Entity_Id;
1924 -- Find renamed entity when the declaration is a renaming_as_body and
1925 -- the renamed entity may itself be a renaming_as_body. Used to enforce
1926 -- rule that a renaming_as_body is illegal if the declaration occurs
1927 -- before the subprogram it completes is frozen, and renaming indirectly
1928 -- renames the subprogram itself.(Defect Report 8652/0027).
1930 ------------------------------
1931 -- Build_Class_Wide_Wrapper --
1932 ------------------------------
1934 procedure Build_Class_Wide_Wrapper
1935 (Ren_Id : out Entity_Id;
1936 Wrap_Id : out Entity_Id)
1938 Loc : constant Source_Ptr := Sloc (N);
1941 (Subp_Id : Entity_Id;
1942 Params : List_Id) return Node_Id;
1943 -- Create a dispatching call to invoke routine Subp_Id with actuals
1944 -- built from the parameter specifications of list Params.
1946 function Build_Spec (Subp_Id : Entity_Id) return Node_Id;
1947 -- Create a subprogram specification based on the subprogram profile
1950 function Find_Primitive (Typ : Entity_Id) return Entity_Id;
1951 -- Find a primitive subprogram of type Typ which matches the profile
1952 -- of the renaming declaration.
1954 procedure Interpretation_Error (Subp_Id : Entity_Id);
1955 -- Emit a continuation error message suggesting subprogram Subp_Id as
1956 -- a possible interpretation.
1958 function Is_Intrinsic_Equality (Subp_Id : Entity_Id) return Boolean;
1959 -- Determine whether subprogram Subp_Id denotes the intrinsic "="
1962 function Is_Suitable_Candidate (Subp_Id : Entity_Id) return Boolean;
1963 -- Determine whether subprogram Subp_Id is a suitable candidate for
1964 -- the role of a wrapped subprogram.
1971 (Subp_Id : Entity_Id;
1972 Params : List_Id) return Node_Id
1974 Actuals : constant List_Id := New_List;
1975 Call_Ref : constant Node_Id := New_Occurrence_Of (Subp_Id, Loc);
1979 -- Build the actual parameters of the call
1981 Formal := First (Params);
1982 while Present (Formal) loop
1984 Make_Identifier (Loc, Chars (Defining_Identifier (Formal))));
1989 -- return Subp_Id (Actuals);
1991 if Ekind_In (Subp_Id, E_Function, E_Operator) then
1993 Make_Simple_Return_Statement (Loc,
1995 Make_Function_Call (Loc,
1997 Parameter_Associations => Actuals));
2000 -- Subp_Id (Actuals);
2004 Make_Procedure_Call_Statement (Loc,
2006 Parameter_Associations => Actuals);
2014 function Build_Spec (Subp_Id : Entity_Id) return Node_Id is
2015 Params : constant List_Id := Copy_Parameter_List (Subp_Id);
2016 Spec_Id : constant Entity_Id :=
2017 Make_Defining_Identifier (Loc,
2018 Chars => New_External_Name (Chars (Subp_Id), 'R'));
2021 if Ekind (Formal_Spec) = E_Procedure then
2023 Make_Procedure_Specification (Loc,
2024 Defining_Unit_Name => Spec_Id,
2025 Parameter_Specifications => Params);
2028 Make_Function_Specification (Loc,
2029 Defining_Unit_Name => Spec_Id,
2030 Parameter_Specifications => Params,
2031 Result_Definition =>
2032 New_Copy_Tree (Result_Definition (Spec)));
2036 --------------------
2037 -- Find_Primitive --
2038 --------------------
2040 function Find_Primitive (Typ : Entity_Id) return Entity_Id is
2041 procedure Replace_Parameter_Types (Spec : Node_Id);
2042 -- Given a specification Spec, replace all class-wide parameter
2043 -- types with reference to type Typ.
2045 -----------------------------
2046 -- Replace_Parameter_Types --
2047 -----------------------------
2049 procedure Replace_Parameter_Types (Spec : Node_Id) is
2051 Formal_Id : Entity_Id;
2052 Formal_Typ : Node_Id;
2055 Formal := First (Parameter_Specifications (Spec));
2056 while Present (Formal) loop
2057 Formal_Id := Defining_Identifier (Formal);
2058 Formal_Typ := Parameter_Type (Formal);
2060 -- Create a new entity for each class-wide formal to prevent
2061 -- aliasing with the original renaming. Replace the type of
2062 -- such a parameter with the candidate type.
2064 if Nkind (Formal_Typ) = N_Identifier
2065 and then Is_Class_Wide_Type (Etype (Formal_Typ))
2067 Set_Defining_Identifier (Formal,
2068 Make_Defining_Identifier (Loc, Chars (Formal_Id)));
2070 Set_Parameter_Type (Formal, New_Occurrence_Of (Typ, Loc));
2075 end Replace_Parameter_Types;
2079 Alt_Ren : constant Node_Id := New_Copy_Tree (N);
2080 Alt_Nam : constant Node_Id := Name (Alt_Ren);
2081 Alt_Spec : constant Node_Id := Specification (Alt_Ren);
2082 Subp_Id : Entity_Id;
2084 -- Start of processing for Find_Primitive
2087 -- Each attempt to find a suitable primitive of a particular type
2088 -- operates on its own copy of the original renaming. As a result
2089 -- the original renaming is kept decoration and side-effect free.
2091 -- Inherit the overloaded status of the renamed subprogram name
2093 if Is_Overloaded (Nam) then
2094 Set_Is_Overloaded (Alt_Nam);
2095 Save_Interps (Nam, Alt_Nam);
2098 -- The copied renaming is hidden from visibility to prevent the
2099 -- pollution of the enclosing context.
2101 Set_Defining_Unit_Name (Alt_Spec, Make_Temporary (Loc, 'R'));
2103 -- The types of all class-wide parameters must be changed to the
2106 Replace_Parameter_Types (Alt_Spec);
2108 -- Try to find a suitable primitive which matches the altered
2109 -- profile of the renaming specification.
2114 Nam => Name (Alt_Ren),
2115 New_S => Analyze_Subprogram_Specification (Alt_Spec),
2116 Is_Actual => Is_Actual);
2118 -- Do not return Any_Id if the resolion of the altered profile
2119 -- failed as this complicates further checks on the caller side,
2120 -- return Empty instead.
2122 if Subp_Id = Any_Id then
2129 --------------------------
2130 -- Interpretation_Error --
2131 --------------------------
2133 procedure Interpretation_Error (Subp_Id : Entity_Id) is
2135 Error_Msg_Sloc := Sloc (Subp_Id);
2137 if Is_Internal (Subp_Id) then
2139 ("\\possible interpretation: predefined & #",
2143 ("\\possible interpretation: & defined #", Spec, Formal_Spec);
2145 end Interpretation_Error;
2147 ---------------------------
2148 -- Is_Intrinsic_Equality --
2149 ---------------------------
2151 function Is_Intrinsic_Equality (Subp_Id : Entity_Id) return Boolean is
2154 Ekind (Subp_Id) = E_Operator
2155 and then Chars (Subp_Id) = Name_Op_Eq
2156 and then Is_Intrinsic_Subprogram (Subp_Id);
2157 end Is_Intrinsic_Equality;
2159 ---------------------------
2160 -- Is_Suitable_Candidate --
2161 ---------------------------
2163 function Is_Suitable_Candidate (Subp_Id : Entity_Id) return Boolean is
2165 if No (Subp_Id) then
2168 -- An intrinsic subprogram is never a good candidate. This is an
2169 -- indication of a missing primitive, either defined directly or
2170 -- inherited from a parent tagged type.
2172 elsif Is_Intrinsic_Subprogram (Subp_Id) then
2178 end Is_Suitable_Candidate;
2182 Actual_Typ : Entity_Id := Empty;
2183 -- The actual class-wide type for Formal_Typ
2185 CW_Prim_OK : Boolean;
2186 CW_Prim_Op : Entity_Id;
2187 -- The class-wide subprogram (if available) which corresponds to the
2188 -- renamed generic formal subprogram.
2190 Formal_Typ : Entity_Id := Empty;
2191 -- The generic formal type with unknown discriminants
2193 Root_Prim_OK : Boolean;
2194 Root_Prim_Op : Entity_Id;
2195 -- The root type primitive (if available) which corresponds to the
2196 -- renamed generic formal subprogram.
2198 Root_Typ : Entity_Id := Empty;
2199 -- The root type of Actual_Typ
2201 Body_Decl : Node_Id;
2203 Prim_Op : Entity_Id;
2204 Spec_Decl : Node_Id;
2206 -- Start of processing for Build_Class_Wide_Wrapper
2209 -- Analyze the specification of the renaming in case the generation
2210 -- of the class-wide wrapper fails.
2212 Ren_Id := Analyze_Subprogram_Specification (Spec);
2215 -- Do not attempt to build a wrapper if the renaming is in error
2217 if Error_Posted (Nam) then
2221 -- Analyze the renamed name, but do not resolve it. The resolution is
2222 -- completed once a suitable subprogram is found.
2226 -- When the renamed name denotes the intrinsic operator equals, the
2227 -- name must be treated as overloaded. This allows for a potential
2228 -- match against the root type's predefined equality function.
2230 if Is_Intrinsic_Equality (Entity (Nam)) then
2231 Set_Is_Overloaded (Nam);
2232 Collect_Interps (Nam);
2235 -- Step 1: Find the generic formal type with unknown discriminants
2236 -- and its corresponding class-wide actual type from the renamed
2237 -- generic formal subprogram.
2239 Formal := First_Formal (Formal_Spec);
2240 while Present (Formal) loop
2241 if Has_Unknown_Discriminants (Etype (Formal))
2242 and then not Is_Class_Wide_Type (Etype (Formal))
2243 and then Is_Class_Wide_Type (Get_Instance_Of (Etype (Formal)))
2245 Formal_Typ := Etype (Formal);
2246 Actual_Typ := Get_Instance_Of (Formal_Typ);
2247 Root_Typ := Etype (Actual_Typ);
2251 Next_Formal (Formal);
2254 -- The specification of the generic formal subprogram should always
2255 -- contain a formal type with unknown discriminants whose actual is
2256 -- a class-wide type, otherwise this indicates a failure in routine
2257 -- Has_Class_Wide_Actual.
2259 pragma Assert (Present (Formal_Typ));
2261 -- Step 2: Find the proper class-wide subprogram or primitive which
2262 -- corresponds to the renamed generic formal subprogram.
2264 CW_Prim_Op := Find_Primitive (Actual_Typ);
2265 CW_Prim_OK := Is_Suitable_Candidate (CW_Prim_Op);
2266 Root_Prim_Op := Find_Primitive (Root_Typ);
2267 Root_Prim_OK := Is_Suitable_Candidate (Root_Prim_Op);
2269 -- The class-wide actual type has two subprograms which correspond to
2270 -- the renamed generic formal subprogram:
2272 -- with procedure Prim_Op (Param : Formal_Typ);
2274 -- procedure Prim_Op (Param : Actual_Typ); -- may be inherited
2275 -- procedure Prim_Op (Param : Actual_Typ'Class);
2277 -- Even though the declaration of the two subprograms is legal, a
2278 -- call to either one is ambiguous and therefore illegal.
2280 if CW_Prim_OK and Root_Prim_OK then
2282 -- A user-defined primitive has precedence over a predefined one
2284 if Is_Internal (CW_Prim_Op)
2285 and then not Is_Internal (Root_Prim_Op)
2287 Prim_Op := Root_Prim_Op;
2289 elsif Is_Internal (Root_Prim_Op)
2290 and then not Is_Internal (CW_Prim_Op)
2292 Prim_Op := CW_Prim_Op;
2294 elsif CW_Prim_Op = Root_Prim_Op then
2295 Prim_Op := Root_Prim_Op;
2297 -- Otherwise both candidate subprograms are user-defined and
2302 ("ambiguous actual for generic subprogram &",
2304 Interpretation_Error (Root_Prim_Op);
2305 Interpretation_Error (CW_Prim_Op);
2309 elsif CW_Prim_OK and not Root_Prim_OK then
2310 Prim_Op := CW_Prim_Op;
2312 elsif not CW_Prim_OK and Root_Prim_OK then
2313 Prim_Op := Root_Prim_Op;
2315 -- An intrinsic equality may act as a suitable candidate in the case
2316 -- of a null type extension where the parent's equality is hidden. A
2317 -- call to an intrinsic equality is expanded as dispatching.
2319 elsif Present (Root_Prim_Op)
2320 and then Is_Intrinsic_Equality (Root_Prim_Op)
2322 Prim_Op := Root_Prim_Op;
2324 -- Otherwise there are no candidate subprograms. Let the caller
2325 -- diagnose the error.
2331 -- At this point resolution has taken place and the name is no longer
2332 -- overloaded. Mark the primitive as referenced.
2334 Set_Is_Overloaded (Name (N), False);
2335 Set_Referenced (Prim_Op);
2337 -- Step 3: Create the declaration and the body of the wrapper, insert
2338 -- all the pieces into the tree.
2341 Make_Subprogram_Declaration (Loc,
2342 Specification => Build_Spec (Ren_Id));
2343 Insert_Before_And_Analyze (N, Spec_Decl);
2345 -- If the operator carries an Eliminated pragma, indicate that the
2346 -- wrapper is also to be eliminated, to prevent spurious error when
2347 -- using gnatelim on programs that include box-initialization of
2348 -- equality operators.
2350 Wrap_Id := Defining_Entity (Spec_Decl);
2351 Set_Is_Eliminated (Wrap_Id, Is_Eliminated (Prim_Op));
2354 Make_Subprogram_Body (Loc,
2355 Specification => Build_Spec (Ren_Id),
2356 Declarations => New_List,
2357 Handled_Statement_Sequence =>
2358 Make_Handled_Sequence_Of_Statements (Loc,
2359 Statements => New_List (
2361 (Subp_Id => Prim_Op,
2363 Parameter_Specifications
2364 (Specification (Spec_Decl))))));
2366 -- The generated body does not freeze and must be analyzed when the
2367 -- class-wide wrapper is frozen. The body is only needed if expansion
2370 if Expander_Active then
2371 Append_Freeze_Action (Wrap_Id, Body_Decl);
2374 -- Step 4: The subprogram renaming aliases the wrapper
2376 Rewrite (Nam, New_Occurrence_Of (Wrap_Id, Loc));
2377 end Build_Class_Wide_Wrapper;
2379 --------------------------
2380 -- Check_Null_Exclusion --
2381 --------------------------
2383 procedure Check_Null_Exclusion
2387 Ren_Formal : Entity_Id;
2388 Sub_Formal : Entity_Id;
2393 Ren_Formal := First_Formal (Ren);
2394 Sub_Formal := First_Formal (Sub);
2395 while Present (Ren_Formal) and then Present (Sub_Formal) loop
2396 if Has_Null_Exclusion (Parent (Ren_Formal))
2398 not (Has_Null_Exclusion (Parent (Sub_Formal))
2399 or else Can_Never_Be_Null (Etype (Sub_Formal)))
2402 ("`NOT NULL` required for parameter &",
2403 Parent (Sub_Formal), Sub_Formal);
2406 Next_Formal (Ren_Formal);
2407 Next_Formal (Sub_Formal);
2410 -- Return profile check
2412 if Nkind (Parent (Ren)) = N_Function_Specification
2413 and then Nkind (Parent (Sub)) = N_Function_Specification
2414 and then Has_Null_Exclusion (Parent (Ren))
2415 and then not (Has_Null_Exclusion (Parent (Sub))
2416 or else Can_Never_Be_Null (Etype (Sub)))
2419 ("return must specify `NOT NULL`",
2420 Result_Definition (Parent (Sub)));
2422 end Check_Null_Exclusion;
2424 ---------------------------
2425 -- Freeze_Actual_Profile --
2426 ---------------------------
2428 procedure Freeze_Actual_Profile is
2430 Has_Untagged_Inc : Boolean;
2431 Instantiation_Node : constant Node_Id := Parent (N);
2434 if Ada_Version >= Ada_2012 then
2435 F := First_Formal (Formal_Spec);
2436 Has_Untagged_Inc := False;
2437 while Present (F) loop
2438 if Ekind (Etype (F)) = E_Incomplete_Type
2439 and then not Is_Tagged_Type (Etype (F))
2441 Has_Untagged_Inc := True;
2445 F := Next_Formal (F);
2448 if Ekind (Formal_Spec) = E_Function
2449 and then not Is_Tagged_Type (Etype (Formal_Spec))
2451 Has_Untagged_Inc := True;
2454 if not Has_Untagged_Inc then
2455 F := First_Formal (Old_S);
2456 while Present (F) loop
2457 Freeze_Before (Instantiation_Node, Etype (F));
2459 if Is_Incomplete_Or_Private_Type (Etype (F))
2460 and then No (Underlying_Type (Etype (F)))
2462 -- Exclude generic types, or types derived from them.
2463 -- They will be frozen in the enclosing instance.
2465 if Is_Generic_Type (Etype (F))
2466 or else Is_Generic_Type (Root_Type (Etype (F)))
2470 -- A limited view of a type declared elsewhere needs no
2471 -- freezing actions.
2473 elsif From_Limited_With (Etype (F)) then
2478 ("type& must be frozen before this point",
2479 Instantiation_Node, Etype (F));
2483 F := Next_Formal (F);
2487 end Freeze_Actual_Profile;
2489 ---------------------------
2490 -- Has_Class_Wide_Actual --
2491 ---------------------------
2493 function Has_Class_Wide_Actual return Boolean is
2495 Formal_Typ : Entity_Id;
2499 Formal := First_Formal (Formal_Spec);
2500 while Present (Formal) loop
2501 Formal_Typ := Etype (Formal);
2503 if Has_Unknown_Discriminants (Formal_Typ)
2504 and then not Is_Class_Wide_Type (Formal_Typ)
2505 and then Is_Class_Wide_Type (Get_Instance_Of (Formal_Typ))
2510 Next_Formal (Formal);
2515 end Has_Class_Wide_Actual;
2517 -------------------------
2518 -- Original_Subprogram --
2519 -------------------------
2521 function Original_Subprogram (Subp : Entity_Id) return Entity_Id is
2522 Orig_Decl : Node_Id;
2523 Orig_Subp : Entity_Id;
2526 -- First case: renamed entity is itself a renaming
2528 if Present (Alias (Subp)) then
2529 return Alias (Subp);
2531 elsif Nkind (Unit_Declaration_Node (Subp)) = N_Subprogram_Declaration
2532 and then Present (Corresponding_Body (Unit_Declaration_Node (Subp)))
2534 -- Check if renamed entity is a renaming_as_body
2537 Unit_Declaration_Node
2538 (Corresponding_Body (Unit_Declaration_Node (Subp)));
2540 if Nkind (Orig_Decl) = N_Subprogram_Renaming_Declaration then
2541 Orig_Subp := Entity (Name (Orig_Decl));
2543 if Orig_Subp = Rename_Spec then
2545 -- Circularity detected
2550 return (Original_Subprogram (Orig_Subp));
2558 end Original_Subprogram;
2562 CW_Actual : constant Boolean := Has_Class_Wide_Actual;
2563 -- Ada 2012 (AI05-071, AI05-0131): True if the renaming is for a
2564 -- defaulted formal subprogram when the actual for a related formal
2565 -- type is class-wide.
2567 Inst_Node : Node_Id := Empty;
2570 -- Start of processing for Analyze_Subprogram_Renaming
2573 -- We must test for the attribute renaming case before the Analyze
2574 -- call because otherwise Sem_Attr will complain that the attribute
2575 -- is missing an argument when it is analyzed.
2577 if Nkind (Nam) = N_Attribute_Reference then
2579 -- In the case of an abstract formal subprogram association, rewrite
2580 -- an actual given by a stream attribute as the name of the
2581 -- corresponding stream primitive of the type.
2583 -- In a generic context the stream operations are not generated, and
2584 -- this must be treated as a normal attribute reference, to be
2585 -- expanded in subsequent instantiations.
2588 and then Is_Abstract_Subprogram (Formal_Spec)
2589 and then Expander_Active
2592 Stream_Prim : Entity_Id;
2593 Prefix_Type : constant Entity_Id := Entity (Prefix (Nam));
2596 -- The class-wide forms of the stream attributes are not
2597 -- primitive dispatching operations (even though they
2598 -- internally dispatch to a stream attribute).
2600 if Is_Class_Wide_Type (Prefix_Type) then
2602 ("attribute must be a primitive dispatching operation",
2607 -- Retrieve the primitive subprogram associated with the
2608 -- attribute. This can only be a stream attribute, since those
2609 -- are the only ones that are dispatching (and the actual for
2610 -- an abstract formal subprogram must be dispatching
2613 case Attribute_Name (Nam) is
2616 Find_Optional_Prim_Op (Prefix_Type, TSS_Stream_Input);
2619 Find_Optional_Prim_Op (Prefix_Type, TSS_Stream_Output);
2622 Find_Optional_Prim_Op (Prefix_Type, TSS_Stream_Read);
2625 Find_Optional_Prim_Op (Prefix_Type, TSS_Stream_Write);
2628 ("attribute must be a primitive"
2629 & " dispatching operation", Nam);
2633 -- If no operation was found, and the type is limited,
2634 -- the user should have defined one.
2636 if No (Stream_Prim) then
2637 if Is_Limited_Type (Prefix_Type) then
2639 ("stream operation not defined for type&",
2643 -- Otherwise, compiler should have generated default
2646 raise Program_Error;
2650 -- Rewrite the attribute into the name of its corresponding
2651 -- primitive dispatching subprogram. We can then proceed with
2652 -- the usual processing for subprogram renamings.
2655 Prim_Name : constant Node_Id :=
2656 Make_Identifier (Sloc (Nam),
2657 Chars => Chars (Stream_Prim));
2659 Set_Entity (Prim_Name, Stream_Prim);
2660 Rewrite (Nam, Prim_Name);
2665 -- Normal processing for a renaming of an attribute
2668 Attribute_Renaming (N);
2673 -- Check whether this declaration corresponds to the instantiation
2674 -- of a formal subprogram.
2676 -- If this is an instantiation, the corresponding actual is frozen and
2677 -- error messages can be made more precise. If this is a default
2678 -- subprogram, the entity is already established in the generic, and is
2679 -- not retrieved by visibility. If it is a default with a box, the
2680 -- candidate interpretations, if any, have been collected when building
2681 -- the renaming declaration. If overloaded, the proper interpretation is
2682 -- determined in Find_Renamed_Entity. If the entity is an operator,
2683 -- Find_Renamed_Entity applies additional visibility checks.
2686 Inst_Node := Unit_Declaration_Node (Formal_Spec);
2688 -- Check whether the renaming is for a defaulted actual subprogram
2689 -- with a class-wide actual.
2691 -- The class-wide wrapper is not needed in GNATprove_Mode and there
2692 -- is an external axiomatization on the package.
2695 and then Box_Present (Inst_Node)
2699 Present (Containing_Package_With_Ext_Axioms (Formal_Spec)))
2701 Build_Class_Wide_Wrapper (New_S, Old_S);
2703 elsif Is_Entity_Name (Nam)
2704 and then Present (Entity (Nam))
2705 and then not Comes_From_Source (Nam)
2706 and then not Is_Overloaded (Nam)
2708 Old_S := Entity (Nam);
2709 New_S := Analyze_Subprogram_Specification (Spec);
2713 if Ekind (Entity (Nam)) = E_Operator then
2717 if Box_Present (Inst_Node) then
2718 Old_S := Find_Renamed_Entity (N, Name (N), New_S, Is_Actual);
2720 -- If there is an immediately visible homonym of the operator
2721 -- and the declaration has a default, this is worth a warning
2722 -- because the user probably did not intend to get the pre-
2723 -- defined operator, visible in the generic declaration. To
2724 -- find if there is an intended candidate, analyze the renaming
2725 -- again in the current context.
2727 elsif Scope (Old_S) = Standard_Standard
2728 and then Present (Default_Name (Inst_Node))
2731 Decl : constant Node_Id := New_Copy_Tree (N);
2735 Set_Entity (Name (Decl), Empty);
2736 Analyze (Name (Decl));
2738 Find_Renamed_Entity (Decl, Name (Decl), New_S, True);
2741 and then In_Open_Scopes (Scope (Hidden))
2742 and then Is_Immediately_Visible (Hidden)
2743 and then Comes_From_Source (Hidden)
2744 and then Hidden /= Old_S
2746 Error_Msg_Sloc := Sloc (Hidden);
2747 Error_Msg_N ("default subprogram is resolved " &
2748 "in the generic declaration " &
2749 "(RM 12.6(17))??", N);
2750 Error_Msg_NE ("\and will not use & #??", N, Hidden);
2758 New_S := Analyze_Subprogram_Specification (Spec);
2762 -- Renamed entity must be analyzed first, to avoid being hidden by
2763 -- new name (which might be the same in a generic instance).
2767 -- The renaming defines a new overloaded entity, which is analyzed
2768 -- like a subprogram declaration.
2770 New_S := Analyze_Subprogram_Specification (Spec);
2773 if Current_Scope /= Standard_Standard then
2774 Set_Is_Pure (New_S, Is_Pure (Current_Scope));
2777 -- Set SPARK mode from current context
2779 Set_SPARK_Pragma (New_S, SPARK_Mode_Pragma);
2780 Set_SPARK_Pragma_Inherited (New_S);
2782 Rename_Spec := Find_Corresponding_Spec (N);
2784 -- Case of Renaming_As_Body
2786 if Present (Rename_Spec) then
2788 -- Renaming declaration is the completion of the declaration of
2789 -- Rename_Spec. We build an actual body for it at the freezing point.
2791 Set_Corresponding_Spec (N, Rename_Spec);
2793 -- Deal with special case of stream functions of abstract types
2796 if Nkind (Unit_Declaration_Node (Rename_Spec)) =
2797 N_Abstract_Subprogram_Declaration
2799 -- Input stream functions are abstract if the object type is
2800 -- abstract. Similarly, all default stream functions for an
2801 -- interface type are abstract. However, these subprograms may
2802 -- receive explicit declarations in representation clauses, making
2803 -- the attribute subprograms usable as defaults in subsequent
2805 -- In this case we rewrite the declaration to make the subprogram
2806 -- non-abstract. We remove the previous declaration, and insert
2807 -- the new one at the point of the renaming, to prevent premature
2808 -- access to unfrozen types. The new declaration reuses the
2809 -- specification of the previous one, and must not be analyzed.
2812 (Is_Primitive (Entity (Nam))
2814 Is_Abstract_Type (Find_Dispatching_Type (Entity (Nam))));
2816 Old_Decl : constant Node_Id :=
2817 Unit_Declaration_Node (Rename_Spec);
2818 New_Decl : constant Node_Id :=
2819 Make_Subprogram_Declaration (Sloc (N),
2821 Relocate_Node (Specification (Old_Decl)));
2824 Insert_After (N, New_Decl);
2825 Set_Is_Abstract_Subprogram (Rename_Spec, False);
2826 Set_Analyzed (New_Decl);
2830 Set_Corresponding_Body (Unit_Declaration_Node (Rename_Spec), New_S);
2832 if Ada_Version = Ada_83 and then Comes_From_Source (N) then
2833 Error_Msg_N ("(Ada 83) renaming cannot serve as a body", N);
2836 Set_Convention (New_S, Convention (Rename_Spec));
2837 Check_Fully_Conformant (New_S, Rename_Spec);
2838 Set_Public_Status (New_S);
2840 -- The specification does not introduce new formals, but only
2841 -- repeats the formals of the original subprogram declaration.
2842 -- For cross-reference purposes, and for refactoring tools, we
2843 -- treat the formals of the renaming declaration as body formals.
2845 Reference_Body_Formals (Rename_Spec, New_S);
2847 -- Indicate that the entity in the declaration functions like the
2848 -- corresponding body, and is not a new entity. The body will be
2849 -- constructed later at the freeze point, so indicate that the
2850 -- completion has not been seen yet.
2852 Set_Ekind (New_S, E_Subprogram_Body);
2853 New_S := Rename_Spec;
2854 Set_Has_Completion (Rename_Spec, False);
2856 -- Ada 2005: check overriding indicator
2858 if Present (Overridden_Operation (Rename_Spec)) then
2859 if Must_Not_Override (Specification (N)) then
2861 ("subprogram& overrides inherited operation",
2864 Style_Check and then not Must_Override (Specification (N))
2866 Style.Missing_Overriding (N, Rename_Spec);
2869 elsif Must_Override (Specification (N)) then
2870 Error_Msg_NE ("subprogram& is not overriding", N, Rename_Spec);
2873 -- Normal subprogram renaming (not renaming as body)
2876 Generate_Definition (New_S);
2877 New_Overloaded_Entity (New_S);
2879 if Is_Entity_Name (Nam)
2880 and then Is_Intrinsic_Subprogram (Entity (Nam))
2884 Check_Delayed_Subprogram (New_S);
2888 -- There is no need for elaboration checks on the new entity, which may
2889 -- be called before the next freezing point where the body will appear.
2890 -- Elaboration checks refer to the real entity, not the one created by
2891 -- the renaming declaration.
2893 Set_Kill_Elaboration_Checks (New_S, True);
2895 -- If we had a previous error, indicate a completely is present to stop
2896 -- junk cascaded messages, but don't take any further action.
2898 if Etype (Nam) = Any_Type then
2899 Set_Has_Completion (New_S);
2902 -- Case where name has the form of a selected component
2904 elsif Nkind (Nam) = N_Selected_Component then
2906 -- A name which has the form A.B can designate an entry of task A, a
2907 -- protected operation of protected object A, or finally a primitive
2908 -- operation of object A. In the later case, A is an object of some
2909 -- tagged type, or an access type that denotes one such. To further
2910 -- distinguish these cases, note that the scope of a task entry or
2911 -- protected operation is type of the prefix.
2913 -- The prefix could be an overloaded function call that returns both
2914 -- kinds of operations. This overloading pathology is left to the
2915 -- dedicated reader ???
2918 T : constant Entity_Id := Etype (Prefix (Nam));
2926 and then Is_Tagged_Type (Designated_Type (T))))
2927 and then Scope (Entity (Selector_Name (Nam))) /= T
2929 Analyze_Renamed_Primitive_Operation
2930 (N, New_S, Present (Rename_Spec));
2934 -- Renamed entity is an entry or protected operation. For those
2935 -- cases an explicit body is built (at the point of freezing of
2936 -- this entity) that contains a call to the renamed entity.
2938 -- This is not allowed for renaming as body if the renamed
2939 -- spec is already frozen (see RM 8.5.4(5) for details).
2941 if Present (Rename_Spec) and then Is_Frozen (Rename_Spec) then
2943 ("renaming-as-body cannot rename entry as subprogram", N);
2945 ("\since & is already frozen (RM 8.5.4(5))",
2948 Analyze_Renamed_Entry (N, New_S, Present (Rename_Spec));
2955 -- Case where name is an explicit dereference X.all
2957 elsif Nkind (Nam) = N_Explicit_Dereference then
2959 -- Renamed entity is designated by access_to_subprogram expression.
2960 -- Must build body to encapsulate call, as in the entry case.
2962 Analyze_Renamed_Dereference (N, New_S, Present (Rename_Spec));
2965 -- Indexed component
2967 elsif Nkind (Nam) = N_Indexed_Component then
2968 Analyze_Renamed_Family_Member (N, New_S, Present (Rename_Spec));
2971 -- Character literal
2973 elsif Nkind (Nam) = N_Character_Literal then
2974 Analyze_Renamed_Character (N, New_S, Present (Rename_Spec));
2977 -- Only remaining case is where we have a non-entity name, or a renaming
2978 -- of some other non-overloadable entity.
2980 elsif not Is_Entity_Name (Nam)
2981 or else not Is_Overloadable (Entity (Nam))
2983 -- Do not mention the renaming if it comes from an instance
2985 if not Is_Actual then
2986 Error_Msg_N ("expect valid subprogram name in renaming", N);
2988 Error_Msg_NE ("no visible subprogram for formal&", N, Nam);
2994 -- Find the renamed entity that matches the given specification. Disable
2995 -- Ada_83 because there is no requirement of full conformance between
2996 -- renamed entity and new entity, even though the same circuit is used.
2998 -- This is a bit of an odd case, which introduces a really irregular use
2999 -- of Ada_Version[_Explicit]. Would be nice to find cleaner way to do
3002 Ada_Version := Ada_Version_Type'Max (Ada_Version, Ada_95);
3003 Ada_Version_Pragma := Empty;
3004 Ada_Version_Explicit := Ada_Version;
3007 Old_S := Find_Renamed_Entity (N, Name (N), New_S, Is_Actual);
3009 -- The visible operation may be an inherited abstract operation that
3010 -- was overridden in the private part, in which case a call will
3011 -- dispatch to the overriding operation. Use the overriding one in
3012 -- the renaming declaration, to prevent spurious errors below.
3014 if Is_Overloadable (Old_S)
3015 and then Is_Abstract_Subprogram (Old_S)
3016 and then No (DTC_Entity (Old_S))
3017 and then Present (Alias (Old_S))
3018 and then not Is_Abstract_Subprogram (Alias (Old_S))
3019 and then Present (Overridden_Operation (Alias (Old_S)))
3021 Old_S := Alias (Old_S);
3024 -- When the renamed subprogram is overloaded and used as an actual
3025 -- of a generic, its entity is set to the first available homonym.
3026 -- We must first disambiguate the name, then set the proper entity.
3028 if Is_Actual and then Is_Overloaded (Nam) then
3029 Set_Entity (Nam, Old_S);
3033 -- Most common case: subprogram renames subprogram. No body is generated
3034 -- in this case, so we must indicate the declaration is complete as is.
3035 -- and inherit various attributes of the renamed subprogram.
3037 if No (Rename_Spec) then
3038 Set_Has_Completion (New_S);
3039 Set_Is_Imported (New_S, Is_Imported (Entity (Nam)));
3040 Set_Is_Pure (New_S, Is_Pure (Entity (Nam)));
3041 Set_Is_Preelaborated (New_S, Is_Preelaborated (Entity (Nam)));
3043 -- The subprogram renaming declaration may become Ghost if it renames
3046 Mark_Renaming_As_Ghost (N, Entity (Nam));
3048 -- Ada 2005 (AI-423): Check the consistency of null exclusions
3049 -- between a subprogram and its correct renaming.
3051 -- Note: the Any_Id check is a guard that prevents compiler crashes
3052 -- when performing a null exclusion check between a renaming and a
3053 -- renamed subprogram that has been found to be illegal.
3055 if Ada_Version >= Ada_2005 and then Entity (Nam) /= Any_Id then
3056 Check_Null_Exclusion
3058 Sub => Entity (Nam));
3061 -- Enforce the Ada 2005 rule that the renamed entity cannot require
3062 -- overriding. The flag Requires_Overriding is set very selectively
3063 -- and misses some other illegal cases. The additional conditions
3064 -- checked below are sufficient but not necessary ???
3066 -- The rule does not apply to the renaming generated for an actual
3067 -- subprogram in an instance.
3072 -- Guard against previous errors, and omit renamings of predefined
3075 elsif not Ekind_In (Old_S, E_Function, E_Procedure) then
3078 elsif Requires_Overriding (Old_S)
3080 (Is_Abstract_Subprogram (Old_S)
3081 and then Present (Find_Dispatching_Type (Old_S))
3083 not Is_Abstract_Type (Find_Dispatching_Type (Old_S)))
3086 ("renamed entity cannot be "
3087 & "subprogram that requires overriding (RM 8.5.4 (5.1))", N);
3091 if Old_S /= Any_Id then
3092 if Is_Actual and then From_Default (N) then
3094 -- This is an implicit reference to the default actual
3096 Generate_Reference (Old_S, Nam, Typ => 'i', Force => True);
3099 Generate_Reference (Old_S, Nam);
3102 Check_Internal_Protected_Use (N, Old_S);
3104 -- For a renaming-as-body, require subtype conformance, but if the
3105 -- declaration being completed has not been frozen, then inherit the
3106 -- convention of the renamed subprogram prior to checking conformance
3107 -- (unless the renaming has an explicit convention established; the
3108 -- rule stated in the RM doesn't seem to address this ???).
3110 if Present (Rename_Spec) then
3111 Generate_Reference (Rename_Spec, Defining_Entity (Spec), 'b');
3112 Style.Check_Identifier (Defining_Entity (Spec), Rename_Spec);
3114 if not Is_Frozen (Rename_Spec) then
3115 if not Has_Convention_Pragma (Rename_Spec) then
3116 Set_Convention (New_S, Convention (Old_S));
3119 if Ekind (Old_S) /= E_Operator then
3120 Check_Mode_Conformant (New_S, Old_S, Spec);
3123 if Original_Subprogram (Old_S) = Rename_Spec then
3124 Error_Msg_N ("unfrozen subprogram cannot rename itself ", N);
3127 Check_Subtype_Conformant (New_S, Old_S, Spec);
3130 Check_Frozen_Renaming (N, Rename_Spec);
3132 -- Check explicitly that renamed entity is not intrinsic, because
3133 -- in a generic the renamed body is not built. In this case,
3134 -- the renaming_as_body is a completion.
3136 if Inside_A_Generic then
3137 if Is_Frozen (Rename_Spec)
3138 and then Is_Intrinsic_Subprogram (Old_S)
3141 ("subprogram in renaming_as_body cannot be intrinsic",
3145 Set_Has_Completion (Rename_Spec);
3148 elsif Ekind (Old_S) /= E_Operator then
3150 -- If this a defaulted subprogram for a class-wide actual there is
3151 -- no check for mode conformance, given that the signatures don't
3152 -- match (the source mentions T but the actual mentions T'Class).
3156 elsif not Is_Actual or else No (Enclosing_Instance) then
3157 Check_Mode_Conformant (New_S, Old_S);
3160 if Is_Actual and then Error_Posted (New_S) then
3161 Error_Msg_NE ("invalid actual subprogram: & #!", N, Old_S);
3165 if No (Rename_Spec) then
3167 -- The parameter profile of the new entity is that of the renamed
3168 -- entity: the subtypes given in the specification are irrelevant.
3170 Inherit_Renamed_Profile (New_S, Old_S);
3172 -- A call to the subprogram is transformed into a call to the
3173 -- renamed entity. This is transitive if the renamed entity is
3174 -- itself a renaming.
3176 if Present (Alias (Old_S)) then
3177 Set_Alias (New_S, Alias (Old_S));
3179 Set_Alias (New_S, Old_S);
3182 -- Note that we do not set Is_Intrinsic_Subprogram if we have a
3183 -- renaming as body, since the entity in this case is not an
3184 -- intrinsic (it calls an intrinsic, but we have a real body for
3185 -- this call, and it is in this body that the required intrinsic
3186 -- processing will take place).
3188 -- Also, if this is a renaming of inequality, the renamed operator
3189 -- is intrinsic, but what matters is the corresponding equality
3190 -- operator, which may be user-defined.
3192 Set_Is_Intrinsic_Subprogram
3194 Is_Intrinsic_Subprogram (Old_S)
3196 (Chars (Old_S) /= Name_Op_Ne
3197 or else Ekind (Old_S) = E_Operator
3198 or else Is_Intrinsic_Subprogram
3199 (Corresponding_Equality (Old_S))));
3201 if Ekind (Alias (New_S)) = E_Operator then
3202 Set_Has_Delayed_Freeze (New_S, False);
3205 -- If the renaming corresponds to an association for an abstract
3206 -- formal subprogram, then various attributes must be set to
3207 -- indicate that the renaming is an abstract dispatching operation
3208 -- with a controlling type.
3210 if Is_Actual and then Is_Abstract_Subprogram (Formal_Spec) then
3212 -- Mark the renaming as abstract here, so Find_Dispatching_Type
3213 -- see it as corresponding to a generic association for a
3214 -- formal abstract subprogram
3216 Set_Is_Abstract_Subprogram (New_S);
3219 New_S_Ctrl_Type : constant Entity_Id :=
3220 Find_Dispatching_Type (New_S);
3221 Old_S_Ctrl_Type : constant Entity_Id :=
3222 Find_Dispatching_Type (Old_S);
3226 -- The actual must match the (instance of the) formal,
3227 -- and must be a controlling type.
3229 if Old_S_Ctrl_Type /= New_S_Ctrl_Type
3230 or else No (New_S_Ctrl_Type)
3233 ("actual must be dispatching subprogram for type&",
3234 Nam, New_S_Ctrl_Type);
3237 Set_Is_Dispatching_Operation (New_S);
3238 Check_Controlling_Formals (New_S_Ctrl_Type, New_S);
3240 -- If the actual in the formal subprogram is itself a
3241 -- formal abstract subprogram association, there's no
3242 -- dispatch table component or position to inherit.
3244 if Present (DTC_Entity (Old_S)) then
3245 Set_DTC_Entity (New_S, DTC_Entity (Old_S));
3246 Set_DT_Position_Value (New_S, DT_Position (Old_S));
3256 -- The following is illegal, because F hides whatever other F may
3258 -- function F (...) renames F;
3261 or else (Nkind (Nam) /= N_Expanded_Name
3262 and then Chars (Old_S) = Chars (New_S))
3264 Error_Msg_N ("subprogram cannot rename itself", N);
3266 -- This is illegal even if we use a selector:
3267 -- function F (...) renames Pkg.F;
3268 -- because F is still hidden.
3270 elsif Nkind (Nam) = N_Expanded_Name
3271 and then Entity (Prefix (Nam)) = Current_Scope
3272 and then Chars (Selector_Name (Nam)) = Chars (New_S)
3274 -- This is an error, but we overlook the error and accept the
3275 -- renaming if the special Overriding_Renamings mode is in effect.
3277 if not Overriding_Renamings then
3279 ("implicit operation& is not visible (RM 8.3 (15))",
3284 Set_Convention (New_S, Convention (Old_S));
3286 if Is_Abstract_Subprogram (Old_S) then
3287 if Present (Rename_Spec) then
3289 ("a renaming-as-body cannot rename an abstract subprogram",
3291 Set_Has_Completion (Rename_Spec);
3293 Set_Is_Abstract_Subprogram (New_S);
3297 Check_Library_Unit_Renaming (N, Old_S);
3299 -- Pathological case: procedure renames entry in the scope of its
3300 -- task. Entry is given by simple name, but body must be built for
3301 -- procedure. Of course if called it will deadlock.
3303 if Ekind (Old_S) = E_Entry then
3304 Set_Has_Completion (New_S, False);
3305 Set_Alias (New_S, Empty);
3309 Freeze_Before (N, Old_S);
3310 Freeze_Actual_Profile;
3311 Set_Has_Delayed_Freeze (New_S, False);
3312 Freeze_Before (N, New_S);
3314 -- An abstract subprogram is only allowed as an actual in the case
3315 -- where the formal subprogram is also abstract.
3317 if (Ekind (Old_S) = E_Procedure or else Ekind (Old_S) = E_Function)
3318 and then Is_Abstract_Subprogram (Old_S)
3319 and then not Is_Abstract_Subprogram (Formal_Spec)
3322 ("abstract subprogram not allowed as generic actual", Nam);
3327 -- A common error is to assume that implicit operators for types are
3328 -- defined in Standard, or in the scope of a subtype. In those cases
3329 -- where the renamed entity is given with an expanded name, it is
3330 -- worth mentioning that operators for the type are not declared in
3331 -- the scope given by the prefix.
3333 if Nkind (Nam) = N_Expanded_Name
3334 and then Nkind (Selector_Name (Nam)) = N_Operator_Symbol
3335 and then Scope (Entity (Nam)) = Standard_Standard
3338 T : constant Entity_Id :=
3339 Base_Type (Etype (First_Formal (New_S)));
3341 Error_Msg_Node_2 := Prefix (Nam);
3343 ("operator for type& is not declared in&", Prefix (Nam), T);
3348 ("no visible subprogram matches the specification for&",
3352 if Present (Candidate_Renaming) then
3359 F1 := First_Formal (Candidate_Renaming);
3360 F2 := First_Formal (New_S);
3361 T1 := First_Subtype (Etype (F1));
3362 while Present (F1) and then Present (F2) loop
3367 if Present (F1) and then Present (Default_Value (F1)) then
3368 if Present (Next_Formal (F1)) then
3370 ("\missing specification for & and other formals with "
3371 & "defaults", Spec, F1);
3373 Error_Msg_NE ("\missing specification for &", Spec, F1);
3377 if Nkind (Nam) = N_Operator_Symbol
3378 and then From_Default (N)
3380 Error_Msg_Node_2 := T1;
3382 ("default & on & is not directly visible",
3389 -- Ada 2005 AI 404: if the new subprogram is dispatching, verify that
3390 -- controlling access parameters are known non-null for the renamed
3391 -- subprogram. Test also applies to a subprogram instantiation that
3392 -- is dispatching. Test is skipped if some previous error was detected
3393 -- that set Old_S to Any_Id.
3395 if Ada_Version >= Ada_2005
3396 and then Old_S /= Any_Id
3397 and then not Is_Dispatching_Operation (Old_S)
3398 and then Is_Dispatching_Operation (New_S)
3405 Old_F := First_Formal (Old_S);
3406 New_F := First_Formal (New_S);
3407 while Present (Old_F) loop
3408 if Ekind (Etype (Old_F)) = E_Anonymous_Access_Type
3409 and then Is_Controlling_Formal (New_F)
3410 and then not Can_Never_Be_Null (Old_F)
3412 Error_Msg_N ("access parameter is controlling,", New_F);
3414 ("\corresponding parameter of& "
3415 & "must be explicitly null excluding", New_F, Old_S);
3418 Next_Formal (Old_F);
3419 Next_Formal (New_F);
3424 -- A useful warning, suggested by Ada Bug Finder (Ada-Europe 2005)
3425 -- is to warn if an operator is being renamed as a different operator.
3426 -- If the operator is predefined, examine the kind of the entity, not
3427 -- the abbreviated declaration in Standard.
3429 if Comes_From_Source (N)
3430 and then Present (Old_S)
3431 and then (Nkind (Old_S) = N_Defining_Operator_Symbol
3432 or else Ekind (Old_S) = E_Operator)
3433 and then Nkind (New_S) = N_Defining_Operator_Symbol
3434 and then Chars (Old_S) /= Chars (New_S)
3437 ("& is being renamed as a different operator??", N, Old_S);
3440 -- Check for renaming of obsolescent subprogram
3442 Check_Obsolescent_2005_Entity (Entity (Nam), Nam);
3444 -- Another warning or some utility: if the new subprogram as the same
3445 -- name as the old one, the old one is not hidden by an outer homograph,
3446 -- the new one is not a public symbol, and the old one is otherwise
3447 -- directly visible, the renaming is superfluous.
3449 if Chars (Old_S) = Chars (New_S)
3450 and then Comes_From_Source (N)
3451 and then Scope (Old_S) /= Standard_Standard
3452 and then Warn_On_Redundant_Constructs
3453 and then (Is_Immediately_Visible (Old_S)
3454 or else Is_Potentially_Use_Visible (Old_S))
3455 and then Is_Overloadable (Current_Scope)
3456 and then Chars (Current_Scope) /= Chars (Old_S)
3459 ("redundant renaming, entity is directly visible?r?", Name (N));
3462 -- Implementation-defined aspect specifications can appear in a renaming
3463 -- declaration, but not language-defined ones. The call to procedure
3464 -- Analyze_Aspect_Specifications will take care of this error check.
3466 if Has_Aspects (N) then
3467 Analyze_Aspect_Specifications (N, New_S);
3470 Ada_Version := Save_AV;
3471 Ada_Version_Pragma := Save_AVP;
3472 Ada_Version_Explicit := Save_AV_Exp;
3474 -- In GNATprove mode, the renamings of actual subprograms are replaced
3475 -- with wrapper functions that make it easier to propagate axioms to the
3476 -- points of call within an instance. Wrappers are generated if formal
3477 -- subprogram is subject to axiomatization.
3479 -- The types in the wrapper profiles are obtained from (instances of)
3480 -- the types of the formal subprogram.
3483 and then GNATprove_Mode
3484 and then Present (Containing_Package_With_Ext_Axioms (Formal_Spec))
3485 and then not Inside_A_Generic
3487 if Ekind (Old_S) = E_Function then
3488 Rewrite (N, Build_Function_Wrapper (Formal_Spec, Old_S));
3491 elsif Ekind (Old_S) = E_Operator then
3492 Rewrite (N, Build_Operator_Wrapper (Formal_Spec, Old_S));
3496 end Analyze_Subprogram_Renaming;
3498 -------------------------
3499 -- Analyze_Use_Package --
3500 -------------------------
3502 -- Resolve the package names in the use clause, and make all the visible
3503 -- entities defined in the package potentially use-visible. If the package
3504 -- is already in use from a previous use clause, its visible entities are
3505 -- already use-visible. In that case, mark the occurrence as a redundant
3506 -- use. If the package is an open scope, i.e. if the use clause occurs
3507 -- within the package itself, ignore it.
3509 procedure Analyze_Use_Package (N : Node_Id) is
3510 Pack_Name : Node_Id;
3513 -- Start of processing for Analyze_Use_Package
3516 Check_SPARK_05_Restriction ("use clause is not allowed", N);
3518 Set_Hidden_By_Use_Clause (N, No_Elist);
3520 -- Use clause not allowed in a spec of a predefined package declaration
3521 -- except that packages whose file name starts a-n are OK (these are
3522 -- children of Ada.Numerics, which are never loaded by Rtsfind).
3524 if Is_Predefined_File_Name (Unit_File_Name (Current_Sem_Unit))
3525 and then Name_Buffer (1 .. 3) /= "a-n"
3527 Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Declaration
3529 Error_Msg_N ("use clause not allowed in predefined spec", N);
3532 -- Chain clause to list of use clauses in current scope
3534 if Nkind (Parent (N)) /= N_Compilation_Unit then
3535 Chain_Use_Clause (N);
3538 -- Loop through package names to identify referenced packages
3540 Pack_Name := First (Names (N));
3541 while Present (Pack_Name) loop
3542 Analyze (Pack_Name);
3544 if Nkind (Parent (N)) = N_Compilation_Unit
3545 and then Nkind (Pack_Name) = N_Expanded_Name
3551 Pref := Prefix (Pack_Name);
3552 while Nkind (Pref) = N_Expanded_Name loop
3553 Pref := Prefix (Pref);
3556 if Entity (Pref) = Standard_Standard then
3558 ("predefined package Standard cannot appear"
3559 & " in a context clause", Pref);
3567 -- Loop through package names to mark all entities as potentially
3570 Pack_Name := First (Names (N));
3571 while Present (Pack_Name) loop
3572 if Is_Entity_Name (Pack_Name) then
3573 Pack := Entity (Pack_Name);
3575 if Ekind (Pack) /= E_Package and then Etype (Pack) /= Any_Type then
3576 if Ekind (Pack) = E_Generic_Package then
3577 Error_Msg_N -- CODEFIX
3578 ("a generic package is not allowed in a use clause",
3581 elsif Ekind_In (Pack, E_Generic_Function, E_Generic_Package)
3583 Error_Msg_N -- CODEFIX
3584 ("a generic subprogram is not allowed in a use clause",
3587 elsif Ekind_In (Pack, E_Function, E_Procedure, E_Operator) then
3588 Error_Msg_N -- CODEFIX
3589 ("a subprogram is not allowed in a use clause",
3593 Error_Msg_N ("& is not allowed in a use clause", Pack_Name);
3597 if Nkind (Parent (N)) = N_Compilation_Unit then
3598 Check_In_Previous_With_Clause (N, Pack_Name);
3601 if Applicable_Use (Pack_Name) then
3602 Use_One_Package (Pack, N);
3606 -- Report error because name denotes something other than a package
3609 Error_Msg_N ("& is not a package", Pack_Name);
3614 end Analyze_Use_Package;
3616 ----------------------
3617 -- Analyze_Use_Type --
3618 ----------------------
3620 procedure Analyze_Use_Type (N : Node_Id) is
3625 Set_Hidden_By_Use_Clause (N, No_Elist);
3627 -- Chain clause to list of use clauses in current scope
3629 if Nkind (Parent (N)) /= N_Compilation_Unit then
3630 Chain_Use_Clause (N);
3633 -- If the Used_Operations list is already initialized, the clause has
3634 -- been analyzed previously, and it is begin reinstalled, for example
3635 -- when the clause appears in a package spec and we are compiling the
3636 -- corresponding package body. In that case, make the entities on the
3637 -- existing list use_visible, and mark the corresponding types In_Use.
3639 if Present (Used_Operations (N)) then
3645 Mark := First (Subtype_Marks (N));
3646 while Present (Mark) loop
3647 Use_One_Type (Mark, Installed => True);
3651 Elmt := First_Elmt (Used_Operations (N));
3652 while Present (Elmt) loop
3653 Set_Is_Potentially_Use_Visible (Node (Elmt));
3661 -- Otherwise, create new list and attach to it the operations that
3662 -- are made use-visible by the clause.
3664 Set_Used_Operations (N, New_Elmt_List);
3665 Id := First (Subtype_Marks (N));
3666 while Present (Id) loop
3670 if E /= Any_Type then
3673 if Nkind (Parent (N)) = N_Compilation_Unit then
3674 if Nkind (Id) = N_Identifier then
3675 Error_Msg_N ("type is not directly visible", Id);
3677 elsif Is_Child_Unit (Scope (E))
3678 and then Scope (E) /= System_Aux_Id
3680 Check_In_Previous_With_Clause (N, Prefix (Id));
3685 -- If the use_type_clause appears in a compilation unit context,
3686 -- check whether it comes from a unit that may appear in a
3687 -- limited_with_clause, for a better error message.
3689 if Nkind (Parent (N)) = N_Compilation_Unit
3690 and then Nkind (Id) /= N_Identifier
3696 function Mentioned (Nam : Node_Id) return Boolean;
3697 -- Check whether the prefix of expanded name for the type
3698 -- appears in the prefix of some limited_with_clause.
3704 function Mentioned (Nam : Node_Id) return Boolean is
3706 return Nkind (Name (Item)) = N_Selected_Component
3707 and then Chars (Prefix (Name (Item))) = Chars (Nam);
3711 Pref := Prefix (Id);
3712 Item := First (Context_Items (Parent (N)));
3713 while Present (Item) and then Item /= N loop
3714 if Nkind (Item) = N_With_Clause
3715 and then Limited_Present (Item)
3716 and then Mentioned (Pref)
3719 (Get_Msg_Id, "premature usage of incomplete type");
3730 end Analyze_Use_Type;
3732 --------------------
3733 -- Applicable_Use --
3734 --------------------
3736 function Applicable_Use (Pack_Name : Node_Id) return Boolean is
3737 Pack : constant Entity_Id := Entity (Pack_Name);
3740 if In_Open_Scopes (Pack) then
3741 if Warn_On_Redundant_Constructs and then Pack = Current_Scope then
3742 Error_Msg_NE -- CODEFIX
3743 ("& is already use-visible within itself?r?", Pack_Name, Pack);
3748 elsif In_Use (Pack) then
3749 Note_Redundant_Use (Pack_Name);
3752 elsif Present (Renamed_Object (Pack))
3753 and then In_Use (Renamed_Object (Pack))
3755 Note_Redundant_Use (Pack_Name);
3763 ------------------------
3764 -- Attribute_Renaming --
3765 ------------------------
3767 procedure Attribute_Renaming (N : Node_Id) is
3768 Loc : constant Source_Ptr := Sloc (N);
3769 Nam : constant Node_Id := Name (N);
3770 Spec : constant Node_Id := Specification (N);
3771 New_S : constant Entity_Id := Defining_Unit_Name (Spec);
3772 Aname : constant Name_Id := Attribute_Name (Nam);
3774 Form_Num : Nat := 0;
3775 Expr_List : List_Id := No_List;
3777 Attr_Node : Node_Id;
3778 Body_Node : Node_Id;
3779 Param_Spec : Node_Id;
3782 Generate_Definition (New_S);
3784 -- This procedure is called in the context of subprogram renaming, and
3785 -- thus the attribute must be one that is a subprogram. All of those
3786 -- have at least one formal parameter, with the exceptions of the GNAT
3787 -- attribute 'Img, which GNAT treats as renameable.
3789 if not Is_Non_Empty_List (Parameter_Specifications (Spec)) then
3790 if Aname /= Name_Img then
3792 ("subprogram renaming an attribute must have formals", N);
3797 Param_Spec := First (Parameter_Specifications (Spec));
3798 while Present (Param_Spec) loop
3799 Form_Num := Form_Num + 1;
3801 if Nkind (Parameter_Type (Param_Spec)) /= N_Access_Definition then
3802 Find_Type (Parameter_Type (Param_Spec));
3804 -- The profile of the new entity denotes the base type (s) of
3805 -- the types given in the specification. For access parameters
3806 -- there are no subtypes involved.
3808 Rewrite (Parameter_Type (Param_Spec),
3810 (Base_Type (Entity (Parameter_Type (Param_Spec))), Loc));
3813 if No (Expr_List) then
3814 Expr_List := New_List;
3817 Append_To (Expr_List,
3818 Make_Identifier (Loc,
3819 Chars => Chars (Defining_Identifier (Param_Spec))));
3821 -- The expressions in the attribute reference are not freeze
3822 -- points. Neither is the attribute as a whole, see below.
3824 Set_Must_Not_Freeze (Last (Expr_List));
3829 -- Immediate error if too many formals. Other mismatches in number or
3830 -- types of parameters are detected when we analyze the body of the
3831 -- subprogram that we construct.
3833 if Form_Num > 2 then
3834 Error_Msg_N ("too many formals for attribute", N);
3836 -- Error if the attribute reference has expressions that look like
3837 -- formal parameters.
3839 elsif Present (Expressions (Nam)) then
3840 Error_Msg_N ("illegal expressions in attribute reference", Nam);
3843 Nam_In (Aname, Name_Compose, Name_Exponent, Name_Leading_Part,
3844 Name_Pos, Name_Round, Name_Scaling,
3847 if Nkind (N) = N_Subprogram_Renaming_Declaration
3848 and then Present (Corresponding_Formal_Spec (N))
3851 ("generic actual cannot be attribute involving universal type",
3855 ("attribute involving a universal type cannot be renamed",
3860 -- Rewrite attribute node to have a list of expressions corresponding to
3861 -- the subprogram formals. A renaming declaration is not a freeze point,
3862 -- and the analysis of the attribute reference should not freeze the
3863 -- type of the prefix. We use the original node in the renaming so that
3864 -- its source location is preserved, and checks on stream attributes are
3865 -- properly applied.
3867 Attr_Node := Relocate_Node (Nam);
3868 Set_Expressions (Attr_Node, Expr_List);
3870 Set_Must_Not_Freeze (Attr_Node);
3871 Set_Must_Not_Freeze (Prefix (Nam));
3873 -- Case of renaming a function
3875 if Nkind (Spec) = N_Function_Specification then
3876 if Is_Procedure_Attribute_Name (Aname) then
3877 Error_Msg_N ("attribute can only be renamed as procedure", Nam);
3881 Find_Type (Result_Definition (Spec));
3882 Rewrite (Result_Definition (Spec),
3884 (Base_Type (Entity (Result_Definition (Spec))), Loc));
3887 Make_Subprogram_Body (Loc,
3888 Specification => Spec,
3889 Declarations => New_List,
3890 Handled_Statement_Sequence =>
3891 Make_Handled_Sequence_Of_Statements (Loc,
3892 Statements => New_List (
3893 Make_Simple_Return_Statement (Loc,
3894 Expression => Attr_Node))));
3896 -- Case of renaming a procedure
3899 if not Is_Procedure_Attribute_Name (Aname) then
3900 Error_Msg_N ("attribute can only be renamed as function", Nam);
3905 Make_Subprogram_Body (Loc,
3906 Specification => Spec,
3907 Declarations => New_List,
3908 Handled_Statement_Sequence =>
3909 Make_Handled_Sequence_Of_Statements (Loc,
3910 Statements => New_List (Attr_Node)));
3913 -- In case of tagged types we add the body of the generated function to
3914 -- the freezing actions of the type (because in the general case such
3915 -- type is still not frozen). We exclude from this processing generic
3916 -- formal subprograms found in instantiations.
3918 -- We must exclude restricted run-time libraries because
3919 -- entity AST_Handler is defined in package System.Aux_Dec which is not
3920 -- available in those platforms. Note that we cannot use the function
3921 -- Restricted_Profile (instead of Configurable_Run_Time_Mode) because
3922 -- the ZFP run-time library is not defined as a profile, and we do not
3923 -- want to deal with AST_Handler in ZFP mode.
3925 if not Configurable_Run_Time_Mode
3926 and then not Present (Corresponding_Formal_Spec (N))
3927 and then Etype (Nam) /= RTE (RE_AST_Handler)
3930 P : constant Node_Id := Prefix (Nam);
3933 -- The prefix of 'Img is an object that is evaluated for each call
3934 -- of the function that renames it.
3936 if Aname = Name_Img then
3937 Preanalyze_And_Resolve (P);
3939 -- For all other attribute renamings, the prefix is a subtype
3945 -- If the target type is not yet frozen, add the body to the
3946 -- actions to be elaborated at freeze time.
3948 if Is_Tagged_Type (Etype (P))
3949 and then In_Open_Scopes (Scope (Etype (P)))
3951 Ensure_Freeze_Node (Etype (P));
3952 Append_Freeze_Action (Etype (P), Body_Node);
3954 Rewrite (N, Body_Node);
3956 Set_Etype (New_S, Base_Type (Etype (New_S)));
3960 -- Generic formal subprograms or AST_Handler renaming
3963 Rewrite (N, Body_Node);
3965 Set_Etype (New_S, Base_Type (Etype (New_S)));
3968 if Is_Compilation_Unit (New_S) then
3970 ("a library unit can only rename another library unit", N);
3973 -- We suppress elaboration warnings for the resulting entity, since
3974 -- clearly they are not needed, and more particularly, in the case
3975 -- of a generic formal subprogram, the resulting entity can appear
3976 -- after the instantiation itself, and thus look like a bogus case
3977 -- of access before elaboration.
3979 Set_Suppress_Elaboration_Warnings (New_S);
3981 end Attribute_Renaming;
3983 ----------------------
3984 -- Chain_Use_Clause --
3985 ----------------------
3987 procedure Chain_Use_Clause (N : Node_Id) is
3989 Level : Int := Scope_Stack.Last;
3992 if not Is_Compilation_Unit (Current_Scope)
3993 or else not Is_Child_Unit (Current_Scope)
3995 null; -- Common case
3997 elsif Defining_Entity (Parent (N)) = Current_Scope then
3998 null; -- Common case for compilation unit
4001 -- If declaration appears in some other scope, it must be in some
4002 -- parent unit when compiling a child.
4004 Pack := Defining_Entity (Parent (N));
4005 if not In_Open_Scopes (Pack) then
4006 null; -- default as well
4008 -- If the use clause appears in an ancestor and we are in the
4009 -- private part of the immediate parent, the use clauses are
4010 -- already installed.
4012 elsif Pack /= Scope (Current_Scope)
4013 and then In_Private_Part (Scope (Current_Scope))
4018 -- Find entry for parent unit in scope stack
4020 while Scope_Stack.Table (Level).Entity /= Pack loop
4026 Set_Next_Use_Clause (N,
4027 Scope_Stack.Table (Level).First_Use_Clause);
4028 Scope_Stack.Table (Level).First_Use_Clause := N;
4029 end Chain_Use_Clause;
4031 ---------------------------
4032 -- Check_Frozen_Renaming --
4033 ---------------------------
4035 procedure Check_Frozen_Renaming (N : Node_Id; Subp : Entity_Id) is
4040 if Is_Frozen (Subp) and then not Has_Completion (Subp) then
4043 (Parent (Declaration_Node (Subp)), Defining_Entity (N));
4045 if Is_Entity_Name (Name (N)) then
4046 Old_S := Entity (Name (N));
4048 if not Is_Frozen (Old_S)
4049 and then Operating_Mode /= Check_Semantics
4051 Append_Freeze_Action (Old_S, B_Node);
4053 Insert_After (N, B_Node);
4057 if Is_Intrinsic_Subprogram (Old_S) and then not In_Instance then
4059 ("subprogram used in renaming_as_body cannot be intrinsic",
4064 Insert_After (N, B_Node);
4068 end Check_Frozen_Renaming;
4070 -------------------------------
4071 -- Set_Entity_Or_Discriminal --
4072 -------------------------------
4074 procedure Set_Entity_Or_Discriminal (N : Node_Id; E : Entity_Id) is
4078 -- If the entity is not a discriminant, or else expansion is disabled,
4079 -- simply set the entity.
4081 if not In_Spec_Expression
4082 or else Ekind (E) /= E_Discriminant
4083 or else Inside_A_Generic
4085 Set_Entity_With_Checks (N, E);
4087 -- The replacement of a discriminant by the corresponding discriminal
4088 -- is not done for a task discriminant that appears in a default
4089 -- expression of an entry parameter. See Exp_Ch2.Expand_Discriminant
4090 -- for details on their handling.
4092 elsif Is_Concurrent_Type (Scope (E)) then
4095 and then not Nkind_In (P, N_Parameter_Specification,
4096 N_Component_Declaration)
4102 and then Nkind (P) = N_Parameter_Specification
4107 Set_Entity (N, Discriminal (E));
4110 -- Otherwise, this is a discriminant in a context in which
4111 -- it is a reference to the corresponding parameter of the
4112 -- init proc for the enclosing type.
4115 Set_Entity (N, Discriminal (E));
4117 end Set_Entity_Or_Discriminal;
4119 -----------------------------------
4120 -- Check_In_Previous_With_Clause --
4121 -----------------------------------
4123 procedure Check_In_Previous_With_Clause
4127 Pack : constant Entity_Id := Entity (Original_Node (Nam));
4132 Item := First (Context_Items (Parent (N)));
4133 while Present (Item) and then Item /= N loop
4134 if Nkind (Item) = N_With_Clause
4136 -- Protect the frontend against previous critical errors
4138 and then Nkind (Name (Item)) /= N_Selected_Component
4139 and then Entity (Name (Item)) = Pack
4143 -- Find root library unit in with_clause
4145 while Nkind (Par) = N_Expanded_Name loop
4146 Par := Prefix (Par);
4149 if Is_Child_Unit (Entity (Original_Node (Par))) then
4150 Error_Msg_NE ("& is not directly visible", Par, Entity (Par));
4159 -- On exit, package is not mentioned in a previous with_clause.
4160 -- Check if its prefix is.
4162 if Nkind (Nam) = N_Expanded_Name then
4163 Check_In_Previous_With_Clause (N, Prefix (Nam));
4165 elsif Pack /= Any_Id then
4166 Error_Msg_NE ("& is not visible", Nam, Pack);
4168 end Check_In_Previous_With_Clause;
4170 ---------------------------------
4171 -- Check_Library_Unit_Renaming --
4172 ---------------------------------
4174 procedure Check_Library_Unit_Renaming (N : Node_Id; Old_E : Entity_Id) is
4178 if Nkind (Parent (N)) /= N_Compilation_Unit then
4181 -- Check for library unit. Note that we used to check for the scope
4182 -- being Standard here, but that was wrong for Standard itself.
4184 elsif not Is_Compilation_Unit (Old_E)
4185 and then not Is_Child_Unit (Old_E)
4187 Error_Msg_N ("renamed unit must be a library unit", Name (N));
4189 -- Entities defined in Standard (operators and boolean literals) cannot
4190 -- be renamed as library units.
4192 elsif Scope (Old_E) = Standard_Standard
4193 and then Sloc (Old_E) = Standard_Location
4195 Error_Msg_N ("renamed unit must be a library unit", Name (N));
4197 elsif Present (Parent_Spec (N))
4198 and then Nkind (Unit (Parent_Spec (N))) = N_Generic_Package_Declaration
4199 and then not Is_Child_Unit (Old_E)
4202 ("renamed unit must be a child unit of generic parent", Name (N));
4204 elsif Nkind (N) in N_Generic_Renaming_Declaration
4205 and then Nkind (Name (N)) = N_Expanded_Name
4206 and then Is_Generic_Instance (Entity (Prefix (Name (N))))
4207 and then Is_Generic_Unit (Old_E)
4210 ("renamed generic unit must be a library unit", Name (N));
4212 elsif Is_Package_Or_Generic_Package (Old_E) then
4214 -- Inherit categorization flags
4216 New_E := Defining_Entity (N);
4217 Set_Is_Pure (New_E, Is_Pure (Old_E));
4218 Set_Is_Preelaborated (New_E, Is_Preelaborated (Old_E));
4219 Set_Is_Remote_Call_Interface (New_E,
4220 Is_Remote_Call_Interface (Old_E));
4221 Set_Is_Remote_Types (New_E, Is_Remote_Types (Old_E));
4222 Set_Is_Shared_Passive (New_E, Is_Shared_Passive (Old_E));
4224 end Check_Library_Unit_Renaming;
4226 ------------------------
4227 -- Enclosing_Instance --
4228 ------------------------
4230 function Enclosing_Instance return Entity_Id is
4234 if not Is_Generic_Instance (Current_Scope) then
4238 S := Scope (Current_Scope);
4239 while S /= Standard_Standard loop
4240 if Is_Generic_Instance (S) then
4248 end Enclosing_Instance;
4254 procedure End_Scope is
4260 Id := First_Entity (Current_Scope);
4261 while Present (Id) loop
4262 -- An entity in the current scope is not necessarily the first one
4263 -- on its homonym chain. Find its predecessor if any,
4264 -- If it is an internal entity, it will not be in the visibility
4265 -- chain altogether, and there is nothing to unchain.
4267 if Id /= Current_Entity (Id) then
4268 Prev := Current_Entity (Id);
4269 while Present (Prev)
4270 and then Present (Homonym (Prev))
4271 and then Homonym (Prev) /= Id
4273 Prev := Homonym (Prev);
4276 -- Skip to end of loop if Id is not in the visibility chain
4278 if No (Prev) or else Homonym (Prev) /= Id then
4286 Set_Is_Immediately_Visible (Id, False);
4288 Outer := Homonym (Id);
4289 while Present (Outer) and then Scope (Outer) = Current_Scope loop
4290 Outer := Homonym (Outer);
4293 -- Reset homonym link of other entities, but do not modify link
4294 -- between entities in current scope, so that the back-end can have
4295 -- a proper count of local overloadings.
4298 Set_Name_Entity_Id (Chars (Id), Outer);
4300 elsif Scope (Prev) /= Scope (Id) then
4301 Set_Homonym (Prev, Outer);
4308 -- If the scope generated freeze actions, place them before the
4309 -- current declaration and analyze them. Type declarations and
4310 -- the bodies of initialization procedures can generate such nodes.
4311 -- We follow the parent chain until we reach a list node, which is
4312 -- the enclosing list of declarations. If the list appears within
4313 -- a protected definition, move freeze nodes outside the protected
4317 (Scope_Stack.Table (Scope_Stack.Last).Pending_Freeze_Actions)
4321 L : constant List_Id := Scope_Stack.Table
4322 (Scope_Stack.Last).Pending_Freeze_Actions;
4325 if Is_Itype (Current_Scope) then
4326 Decl := Associated_Node_For_Itype (Current_Scope);
4328 Decl := Parent (Current_Scope);
4333 while not (Is_List_Member (Decl))
4334 or else Nkind_In (Parent (Decl), N_Protected_Definition,
4337 Decl := Parent (Decl);
4340 Insert_List_Before_And_Analyze (Decl, L);
4348 ---------------------
4349 -- End_Use_Clauses --
4350 ---------------------
4352 procedure End_Use_Clauses (Clause : Node_Id) is
4356 -- Remove Use_Type clauses first, because they affect the
4357 -- visibility of operators in subsequent used packages.
4360 while Present (U) loop
4361 if Nkind (U) = N_Use_Type_Clause then
4365 Next_Use_Clause (U);
4369 while Present (U) loop
4370 if Nkind (U) = N_Use_Package_Clause then
4371 End_Use_Package (U);
4374 Next_Use_Clause (U);
4376 end End_Use_Clauses;
4378 ---------------------
4379 -- End_Use_Package --
4380 ---------------------
4382 procedure End_Use_Package (N : Node_Id) is
4383 Pack_Name : Node_Id;
4388 function Is_Primitive_Operator_In_Use
4390 F : Entity_Id) return Boolean;
4391 -- Check whether Op is a primitive operator of a use-visible type
4393 ----------------------------------
4394 -- Is_Primitive_Operator_In_Use --
4395 ----------------------------------
4397 function Is_Primitive_Operator_In_Use
4399 F : Entity_Id) return Boolean
4401 T : constant Entity_Id := Base_Type (Etype (F));
4403 return In_Use (T) and then Scope (T) = Scope (Op);
4404 end Is_Primitive_Operator_In_Use;
4406 -- Start of processing for End_Use_Package
4409 Pack_Name := First (Names (N));
4410 while Present (Pack_Name) loop
4412 -- Test that Pack_Name actually denotes a package before processing
4414 if Is_Entity_Name (Pack_Name)
4415 and then Ekind (Entity (Pack_Name)) = E_Package
4417 Pack := Entity (Pack_Name);
4419 if In_Open_Scopes (Pack) then
4422 elsif not Redundant_Use (Pack_Name) then
4423 Set_In_Use (Pack, False);
4424 Set_Current_Use_Clause (Pack, Empty);
4426 Id := First_Entity (Pack);
4427 while Present (Id) loop
4429 -- Preserve use-visibility of operators that are primitive
4430 -- operators of a type that is use-visible through an active
4433 if Nkind (Id) = N_Defining_Operator_Symbol
4435 (Is_Primitive_Operator_In_Use (Id, First_Formal (Id))
4437 (Present (Next_Formal (First_Formal (Id)))
4439 Is_Primitive_Operator_In_Use
4440 (Id, Next_Formal (First_Formal (Id)))))
4444 Set_Is_Potentially_Use_Visible (Id, False);
4447 if Is_Private_Type (Id)
4448 and then Present (Full_View (Id))
4450 Set_Is_Potentially_Use_Visible (Full_View (Id), False);
4456 if Present (Renamed_Object (Pack)) then
4457 Set_In_Use (Renamed_Object (Pack), False);
4458 Set_Current_Use_Clause (Renamed_Object (Pack), Empty);
4461 if Chars (Pack) = Name_System
4462 and then Scope (Pack) = Standard_Standard
4463 and then Present_System_Aux
4465 Id := First_Entity (System_Aux_Id);
4466 while Present (Id) loop
4467 Set_Is_Potentially_Use_Visible (Id, False);
4469 if Is_Private_Type (Id)
4470 and then Present (Full_View (Id))
4472 Set_Is_Potentially_Use_Visible (Full_View (Id), False);
4478 Set_In_Use (System_Aux_Id, False);
4482 Set_Redundant_Use (Pack_Name, False);
4489 if Present (Hidden_By_Use_Clause (N)) then
4490 Elmt := First_Elmt (Hidden_By_Use_Clause (N));
4491 while Present (Elmt) loop
4493 E : constant Entity_Id := Node (Elmt);
4496 -- Reset either Use_Visibility or Direct_Visibility, depending
4497 -- on how the entity was hidden by the use clause.
4499 if In_Use (Scope (E))
4500 and then Used_As_Generic_Actual (Scope (E))
4502 Set_Is_Potentially_Use_Visible (Node (Elmt));
4504 Set_Is_Immediately_Visible (Node (Elmt));
4511 Set_Hidden_By_Use_Clause (N, No_Elist);
4513 end End_Use_Package;
4519 procedure End_Use_Type (N : Node_Id) is
4524 -- Start of processing for End_Use_Type
4527 Id := First (Subtype_Marks (N));
4528 while Present (Id) loop
4530 -- A call to Rtsfind may occur while analyzing a use_type clause,
4531 -- in which case the type marks are not resolved yet, and there is
4532 -- nothing to remove.
4534 if not Is_Entity_Name (Id) or else No (Entity (Id)) then
4540 if T = Any_Type or else From_Limited_With (T) then
4543 -- Note that the use_type clause may mention a subtype of the type
4544 -- whose primitive operations have been made visible. Here as
4545 -- elsewhere, it is the base type that matters for visibility.
4547 elsif In_Open_Scopes (Scope (Base_Type (T))) then
4550 elsif not Redundant_Use (Id) then
4551 Set_In_Use (T, False);
4552 Set_In_Use (Base_Type (T), False);
4553 Set_Current_Use_Clause (T, Empty);
4554 Set_Current_Use_Clause (Base_Type (T), Empty);
4561 if Is_Empty_Elmt_List (Used_Operations (N)) then
4565 Elmt := First_Elmt (Used_Operations (N));
4566 while Present (Elmt) loop
4567 Set_Is_Potentially_Use_Visible (Node (Elmt), False);
4573 ----------------------
4574 -- Find_Direct_Name --
4575 ----------------------
4577 procedure Find_Direct_Name (N : Node_Id) is
4582 Inst : Entity_Id := Empty;
4583 -- Enclosing instance, if any
4585 Homonyms : Entity_Id;
4586 -- Saves start of homonym chain
4588 Nvis_Entity : Boolean;
4589 -- Set True to indicate that there is at least one entity on the homonym
4590 -- chain which, while not visible, is visible enough from the user point
4591 -- of view to warrant an error message of "not visible" rather than
4594 Nvis_Is_Private_Subprg : Boolean := False;
4595 -- Ada 2005 (AI-262): Set True to indicate that a form of Beaujolais
4596 -- effect concerning library subprograms has been detected. Used to
4597 -- generate the precise error message.
4599 function From_Actual_Package (E : Entity_Id) return Boolean;
4600 -- Returns true if the entity is an actual for a package that is itself
4601 -- an actual for a formal package of the current instance. Such an
4602 -- entity requires special handling because it may be use-visible but
4603 -- hides directly visible entities defined outside the instance, because
4604 -- the corresponding formal did so in the generic.
4606 function Is_Actual_Parameter return Boolean;
4607 -- This function checks if the node N is an identifier that is an actual
4608 -- parameter of a procedure call. If so it returns True, otherwise it
4609 -- return False. The reason for this check is that at this stage we do
4610 -- not know what procedure is being called if the procedure might be
4611 -- overloaded, so it is premature to go setting referenced flags or
4612 -- making calls to Generate_Reference. We will wait till Resolve_Actuals
4613 -- for that processing
4615 function Known_But_Invisible (E : Entity_Id) return Boolean;
4616 -- This function determines whether a reference to the entity E, which
4617 -- is not visible, can reasonably be considered to be known to the
4618 -- writer of the reference. This is a heuristic test, used only for
4619 -- the purposes of figuring out whether we prefer to complain that an
4620 -- entity is undefined or invisible (and identify the declaration of
4621 -- the invisible entity in the latter case). The point here is that we
4622 -- don't want to complain that something is invisible and then point to
4623 -- something entirely mysterious to the writer.
4625 procedure Nvis_Messages;
4626 -- Called if there are no visible entries for N, but there is at least
4627 -- one non-directly visible, or hidden declaration. This procedure
4628 -- outputs an appropriate set of error messages.
4630 procedure Undefined (Nvis : Boolean);
4631 -- This function is called if the current node has no corresponding
4632 -- visible entity or entities. The value set in Msg indicates whether
4633 -- an error message was generated (multiple error messages for the
4634 -- same variable are generally suppressed, see body for details).
4635 -- Msg is True if an error message was generated, False if not. This
4636 -- value is used by the caller to determine whether or not to output
4637 -- additional messages where appropriate. The parameter is set False
4638 -- to get the message "X is undefined", and True to get the message
4639 -- "X is not visible".
4641 -------------------------
4642 -- From_Actual_Package --
4643 -------------------------
4645 function From_Actual_Package (E : Entity_Id) return Boolean is
4646 Scop : constant Entity_Id := Scope (E);
4647 -- Declared scope of candidate entity
4651 function Declared_In_Actual (Pack : Entity_Id) return Boolean;
4652 -- Recursive function that does the work and examines actuals of
4653 -- actual packages of current instance.
4655 ------------------------
4656 -- Declared_In_Actual --
4657 ------------------------
4659 function Declared_In_Actual (Pack : Entity_Id) return Boolean is
4663 if No (Associated_Formal_Package (Pack)) then
4667 Act := First_Entity (Pack);
4668 while Present (Act) loop
4669 if Renamed_Object (Pack) = Scop then
4672 -- Check for end of list of actuals.
4674 elsif Ekind (Act) = E_Package
4675 and then Renamed_Object (Act) = Pack
4679 elsif Ekind (Act) = E_Package
4680 and then Declared_In_Actual (Act)
4690 end Declared_In_Actual;
4692 -- Start of processing for From_Actual_Package
4695 if not In_Instance then
4699 Inst := Current_Scope;
4700 while Present (Inst)
4701 and then Ekind (Inst) /= E_Package
4702 and then not Is_Generic_Instance (Inst)
4704 Inst := Scope (Inst);
4711 Act := First_Entity (Inst);
4712 while Present (Act) loop
4713 if Ekind (Act) = E_Package
4714 and then Declared_In_Actual (Act)
4724 end From_Actual_Package;
4726 -------------------------
4727 -- Is_Actual_Parameter --
4728 -------------------------
4730 function Is_Actual_Parameter return Boolean is
4733 Nkind (N) = N_Identifier
4735 (Nkind (Parent (N)) = N_Procedure_Call_Statement
4737 (Nkind (Parent (N)) = N_Parameter_Association
4738 and then N = Explicit_Actual_Parameter (Parent (N))
4739 and then Nkind (Parent (Parent (N))) =
4740 N_Procedure_Call_Statement));
4741 end Is_Actual_Parameter;
4743 -------------------------
4744 -- Known_But_Invisible --
4745 -------------------------
4747 function Known_But_Invisible (E : Entity_Id) return Boolean is
4748 Fname : File_Name_Type;
4751 -- Entities in Standard are always considered to be known
4753 if Sloc (E) <= Standard_Location then
4756 -- An entity that does not come from source is always considered
4757 -- to be unknown, since it is an artifact of code expansion.
4759 elsif not Comes_From_Source (E) then
4762 -- In gnat internal mode, we consider all entities known. The
4763 -- historical reason behind this discrepancy is not known??? But the
4764 -- only effect is to modify the error message given, so it is not
4765 -- critical. Since it only affects the exact wording of error
4766 -- messages in illegal programs, we do not mention this as an
4767 -- effect of -gnatg, since it is not a language modification.
4769 elsif GNAT_Mode then
4773 -- Here we have an entity that is not from package Standard, and
4774 -- which comes from Source. See if it comes from an internal file.
4776 Fname := Unit_File_Name (Get_Source_Unit (E));
4778 -- Case of from internal file
4780 if Is_Internal_File_Name (Fname) then
4782 -- Private part entities in internal files are never considered
4783 -- to be known to the writer of normal application code.
4785 if Is_Hidden (E) then
4789 -- Entities from System packages other than System and
4790 -- System.Storage_Elements are not considered to be known.
4791 -- System.Auxxxx files are also considered known to the user.
4793 -- Should refine this at some point to generally distinguish
4794 -- between known and unknown internal files ???
4796 Get_Name_String (Fname);
4801 Name_Buffer (1 .. 2) /= "s-"
4803 Name_Buffer (3 .. 8) = "stoele"
4805 Name_Buffer (3 .. 5) = "aux";
4807 -- If not an internal file, then entity is definitely known,
4808 -- even if it is in a private part (the message generated will
4809 -- note that it is in a private part)
4814 end Known_But_Invisible;
4820 procedure Nvis_Messages is
4821 Comp_Unit : Node_Id;
4823 Found : Boolean := False;
4824 Hidden : Boolean := False;
4828 -- Ada 2005 (AI-262): Generate a precise error concerning the
4829 -- Beaujolais effect that was previously detected
4831 if Nvis_Is_Private_Subprg then
4833 pragma Assert (Nkind (E2) = N_Defining_Identifier
4834 and then Ekind (E2) = E_Function
4835 and then Scope (E2) = Standard_Standard
4836 and then Has_Private_With (E2));
4838 -- Find the sloc corresponding to the private with'ed unit
4840 Comp_Unit := Cunit (Current_Sem_Unit);
4841 Error_Msg_Sloc := No_Location;
4843 Item := First (Context_Items (Comp_Unit));
4844 while Present (Item) loop
4845 if Nkind (Item) = N_With_Clause
4846 and then Private_Present (Item)
4847 and then Entity (Name (Item)) = E2
4849 Error_Msg_Sloc := Sloc (Item);
4856 pragma Assert (Error_Msg_Sloc /= No_Location);
4858 Error_Msg_N ("(Ada 2005): hidden by private with clause #", N);
4862 Undefined (Nvis => True);
4866 -- First loop does hidden declarations
4869 while Present (Ent) loop
4870 if Is_Potentially_Use_Visible (Ent) then
4872 Error_Msg_N -- CODEFIX
4873 ("multiple use clauses cause hiding!", N);
4877 Error_Msg_Sloc := Sloc (Ent);
4878 Error_Msg_N -- CODEFIX
4879 ("hidden declaration#!", N);
4882 Ent := Homonym (Ent);
4885 -- If we found hidden declarations, then that's enough, don't
4886 -- bother looking for non-visible declarations as well.
4892 -- Second loop does non-directly visible declarations
4895 while Present (Ent) loop
4896 if not Is_Potentially_Use_Visible (Ent) then
4898 -- Do not bother the user with unknown entities
4900 if not Known_But_Invisible (Ent) then
4904 Error_Msg_Sloc := Sloc (Ent);
4906 -- Output message noting that there is a non-visible
4907 -- declaration, distinguishing the private part case.
4909 if Is_Hidden (Ent) then
4910 Error_Msg_N ("non-visible (private) declaration#!", N);
4912 -- If the entity is declared in a generic package, it
4913 -- cannot be visible, so there is no point in adding it
4914 -- to the list of candidates if another homograph from a
4915 -- non-generic package has been seen.
4917 elsif Ekind (Scope (Ent)) = E_Generic_Package
4923 Error_Msg_N -- CODEFIX
4924 ("non-visible declaration#!", N);
4926 if Ekind (Scope (Ent)) /= E_Generic_Package then
4930 if Is_Compilation_Unit (Ent)
4932 Nkind (Parent (Parent (N))) = N_Use_Package_Clause
4934 Error_Msg_Qual_Level := 99;
4935 Error_Msg_NE -- CODEFIX
4936 ("\\missing `WITH &;`", N, Ent);
4937 Error_Msg_Qual_Level := 0;
4940 if Ekind (Ent) = E_Discriminant
4941 and then Present (Corresponding_Discriminant (Ent))
4942 and then Scope (Corresponding_Discriminant (Ent)) =
4946 ("inherited discriminant not allowed here" &
4947 " (RM 3.8 (12), 3.8.1 (6))!", N);
4951 -- Set entity and its containing package as referenced. We
4952 -- can't be sure of this, but this seems a better choice
4953 -- to avoid unused entity messages.
4955 if Comes_From_Source (Ent) then
4956 Set_Referenced (Ent);
4957 Set_Referenced (Cunit_Entity (Get_Source_Unit (Ent)));
4962 Ent := Homonym (Ent);
4971 procedure Undefined (Nvis : Boolean) is
4972 Emsg : Error_Msg_Id;
4975 -- We should never find an undefined internal name. If we do, then
4976 -- see if we have previous errors. If so, ignore on the grounds that
4977 -- it is probably a cascaded message (e.g. a block label from a badly
4978 -- formed block). If no previous errors, then we have a real internal
4979 -- error of some kind so raise an exception.
4981 if Is_Internal_Name (Chars (N)) then
4982 if Total_Errors_Detected /= 0 then
4985 raise Program_Error;
4989 -- A very specialized error check, if the undefined variable is
4990 -- a case tag, and the case type is an enumeration type, check
4991 -- for a possible misspelling, and if so, modify the identifier
4993 -- Named aggregate should also be handled similarly ???
4995 if Nkind (N) = N_Identifier
4996 and then Nkind (Parent (N)) = N_Case_Statement_Alternative
4999 Case_Stm : constant Node_Id := Parent (Parent (N));
5000 Case_Typ : constant Entity_Id := Etype (Expression (Case_Stm));
5005 if Is_Enumeration_Type (Case_Typ)
5006 and then not Is_Standard_Character_Type (Case_Typ)
5008 Lit := First_Literal (Case_Typ);
5009 Get_Name_String (Chars (Lit));
5011 if Chars (Lit) /= Chars (N)
5012 and then Is_Bad_Spelling_Of (Chars (N), Chars (Lit))
5014 Error_Msg_Node_2 := Lit;
5015 Error_Msg_N -- CODEFIX
5016 ("& is undefined, assume misspelling of &", N);
5017 Rewrite (N, New_Occurrence_Of (Lit, Sloc (N)));
5021 Lit := Next_Literal (Lit);
5026 -- Normal processing
5028 Set_Entity (N, Any_Id);
5029 Set_Etype (N, Any_Type);
5031 -- We use the table Urefs to keep track of entities for which we
5032 -- have issued errors for undefined references. Multiple errors
5033 -- for a single name are normally suppressed, however we modify
5034 -- the error message to alert the programmer to this effect.
5036 for J in Urefs.First .. Urefs.Last loop
5037 if Chars (N) = Chars (Urefs.Table (J).Node) then
5038 if Urefs.Table (J).Err /= No_Error_Msg
5039 and then Sloc (N) /= Urefs.Table (J).Loc
5041 Error_Msg_Node_1 := Urefs.Table (J).Node;
5043 if Urefs.Table (J).Nvis then
5044 Change_Error_Text (Urefs.Table (J).Err,
5045 "& is not visible (more references follow)");
5047 Change_Error_Text (Urefs.Table (J).Err,
5048 "& is undefined (more references follow)");
5051 Urefs.Table (J).Err := No_Error_Msg;
5054 -- Although we will set Msg False, and thus suppress the
5055 -- message, we also set Error_Posted True, to avoid any
5056 -- cascaded messages resulting from the undefined reference.
5059 Set_Error_Posted (N, True);
5064 -- If entry not found, this is first undefined occurrence
5067 Error_Msg_N ("& is not visible!", N);
5071 Error_Msg_N ("& is undefined!", N);
5074 -- A very bizarre special check, if the undefined identifier
5075 -- is put or put_line, then add a special error message (since
5076 -- this is a very common error for beginners to make).
5078 if Nam_In (Chars (N), Name_Put, Name_Put_Line) then
5079 Error_Msg_N -- CODEFIX
5080 ("\\possible missing `WITH Ada.Text_'I'O; " &
5081 "USE Ada.Text_'I'O`!", N);
5083 -- Another special check if N is the prefix of a selected
5084 -- component which is a known unit, add message complaining
5085 -- about missing with for this unit.
5087 elsif Nkind (Parent (N)) = N_Selected_Component
5088 and then N = Prefix (Parent (N))
5089 and then Is_Known_Unit (Parent (N))
5091 Error_Msg_Node_2 := Selector_Name (Parent (N));
5092 Error_Msg_N -- CODEFIX
5093 ("\\missing `WITH &.&;`", Prefix (Parent (N)));
5096 -- Now check for possible misspellings
5100 Ematch : Entity_Id := Empty;
5102 Last_Name_Id : constant Name_Id :=
5103 Name_Id (Nat (First_Name_Id) +
5104 Name_Entries_Count - 1);
5107 for Nam in First_Name_Id .. Last_Name_Id loop
5108 E := Get_Name_Entity_Id (Nam);
5111 and then (Is_Immediately_Visible (E)
5113 Is_Potentially_Use_Visible (E))
5115 if Is_Bad_Spelling_Of (Chars (N), Nam) then
5122 if Present (Ematch) then
5123 Error_Msg_NE -- CODEFIX
5124 ("\possible misspelling of&", N, Ematch);
5129 -- Make entry in undefined references table unless the full errors
5130 -- switch is set, in which case by refraining from generating the
5131 -- table entry, we guarantee that we get an error message for every
5132 -- undefined reference.
5134 if not All_Errors_Mode then
5145 -- Start of processing for Find_Direct_Name
5148 -- If the entity pointer is already set, this is an internal node, or
5149 -- a node that is analyzed more than once, after a tree modification.
5150 -- In such a case there is no resolution to perform, just set the type.
5152 if Present (Entity (N)) then
5153 if Is_Type (Entity (N)) then
5154 Set_Etype (N, Entity (N));
5158 Entyp : constant Entity_Id := Etype (Entity (N));
5161 -- One special case here. If the Etype field is already set,
5162 -- and references the packed array type corresponding to the
5163 -- etype of the referenced entity, then leave it alone. This
5164 -- happens for trees generated from Exp_Pakd, where expressions
5165 -- can be deliberately "mis-typed" to the packed array type.
5167 if Is_Array_Type (Entyp)
5168 and then Is_Packed (Entyp)
5169 and then Present (Etype (N))
5170 and then Etype (N) = Packed_Array_Impl_Type (Entyp)
5174 -- If not that special case, then just reset the Etype
5177 Set_Etype (N, Etype (Entity (N)));
5185 -- Here if Entity pointer was not set, we need full visibility analysis
5186 -- First we generate debugging output if the debug E flag is set.
5188 if Debug_Flag_E then
5189 Write_Str ("Looking for ");
5190 Write_Name (Chars (N));
5194 Homonyms := Current_Entity (N);
5195 Nvis_Entity := False;
5198 while Present (E) loop
5200 -- If entity is immediately visible or potentially use visible, then
5201 -- process the entity and we are done.
5203 if Is_Immediately_Visible (E) then
5204 goto Immediately_Visible_Entity;
5206 elsif Is_Potentially_Use_Visible (E) then
5207 goto Potentially_Use_Visible_Entity;
5209 -- Note if a known but invisible entity encountered
5211 elsif Known_But_Invisible (E) then
5212 Nvis_Entity := True;
5215 -- Move to next entity in chain and continue search
5220 -- If no entries on homonym chain that were potentially visible,
5221 -- and no entities reasonably considered as non-visible, then
5222 -- we have a plain undefined reference, with no additional
5223 -- explanation required.
5225 if not Nvis_Entity then
5226 Undefined (Nvis => False);
5228 -- Otherwise there is at least one entry on the homonym chain that
5229 -- is reasonably considered as being known and non-visible.
5237 -- Processing for a potentially use visible entry found. We must search
5238 -- the rest of the homonym chain for two reasons. First, if there is a
5239 -- directly visible entry, then none of the potentially use-visible
5240 -- entities are directly visible (RM 8.4(10)). Second, we need to check
5241 -- for the case of multiple potentially use-visible entries hiding one
5242 -- another and as a result being non-directly visible (RM 8.4(11)).
5244 <<Potentially_Use_Visible_Entity>> declare
5245 Only_One_Visible : Boolean := True;
5246 All_Overloadable : Boolean := Is_Overloadable (E);
5250 while Present (E2) loop
5251 if Is_Immediately_Visible (E2) then
5253 -- If the use-visible entity comes from the actual for a
5254 -- formal package, it hides a directly visible entity from
5255 -- outside the instance.
5257 if From_Actual_Package (E)
5258 and then Scope_Depth (E2) < Scope_Depth (Inst)
5263 goto Immediately_Visible_Entity;
5266 elsif Is_Potentially_Use_Visible (E2) then
5267 Only_One_Visible := False;
5268 All_Overloadable := All_Overloadable and Is_Overloadable (E2);
5270 -- Ada 2005 (AI-262): Protect against a form of Beaujolais effect
5271 -- that can occur in private_with clauses. Example:
5274 -- private with B; package A is
5275 -- package C is function B return Integer;
5277 -- V1 : Integer := B;
5278 -- private function B return Integer;
5279 -- V2 : Integer := B;
5282 -- V1 resolves to A.B, but V2 resolves to library unit B
5284 elsif Ekind (E2) = E_Function
5285 and then Scope (E2) = Standard_Standard
5286 and then Has_Private_With (E2)
5288 Only_One_Visible := False;
5289 All_Overloadable := False;
5290 Nvis_Is_Private_Subprg := True;
5297 -- On falling through this loop, we have checked that there are no
5298 -- immediately visible entities. Only_One_Visible is set if exactly
5299 -- one potentially use visible entity exists. All_Overloadable is
5300 -- set if all the potentially use visible entities are overloadable.
5301 -- The condition for legality is that either there is one potentially
5302 -- use visible entity, or if there is more than one, then all of them
5303 -- are overloadable.
5305 if Only_One_Visible or All_Overloadable then
5308 -- If there is more than one potentially use-visible entity and at
5309 -- least one of them non-overloadable, we have an error (RM 8.4(11)).
5310 -- Note that E points to the first such entity on the homonym list.
5311 -- Special case: if one of the entities is declared in an actual
5312 -- package, it was visible in the generic, and takes precedence over
5313 -- other entities that are potentially use-visible. Same if it is
5314 -- declared in a local instantiation of the current instance.
5319 -- Find current instance
5321 Inst := Current_Scope;
5322 while Present (Inst) and then Inst /= Standard_Standard loop
5323 if Is_Generic_Instance (Inst) then
5327 Inst := Scope (Inst);
5331 while Present (E2) loop
5332 if From_Actual_Package (E2)
5334 (Is_Generic_Instance (Scope (E2))
5335 and then Scope_Depth (Scope (E2)) > Scope_Depth (Inst))
5348 Is_Predefined_File_Name (Unit_File_Name (Current_Sem_Unit))
5350 -- A use-clause in the body of a system file creates conflict
5351 -- with some entity in a user scope, while rtsfind is active.
5352 -- Keep only the entity coming from another predefined unit.
5355 while Present (E2) loop
5356 if Is_Predefined_File_Name
5357 (Unit_File_Name (Get_Source_Unit (Sloc (E2))))
5366 -- Entity must exist because predefined unit is correct
5368 raise Program_Error;
5377 -- Come here with E set to the first immediately visible entity on
5378 -- the homonym chain. This is the one we want unless there is another
5379 -- immediately visible entity further on in the chain for an inner
5380 -- scope (RM 8.3(8)).
5382 <<Immediately_Visible_Entity>> declare
5387 -- Find scope level of initial entity. When compiling through
5388 -- Rtsfind, the previous context is not completely invisible, and
5389 -- an outer entity may appear on the chain, whose scope is below
5390 -- the entry for Standard that delimits the current scope stack.
5391 -- Indicate that the level for this spurious entry is outside of
5392 -- the current scope stack.
5394 Level := Scope_Stack.Last;
5396 Scop := Scope_Stack.Table (Level).Entity;
5397 exit when Scop = Scope (E);
5399 exit when Scop = Standard_Standard;
5402 -- Now search remainder of homonym chain for more inner entry
5403 -- If the entity is Standard itself, it has no scope, and we
5404 -- compare it with the stack entry directly.
5407 while Present (E2) loop
5408 if Is_Immediately_Visible (E2) then
5410 -- If a generic package contains a local declaration that
5411 -- has the same name as the generic, there may be a visibility
5412 -- conflict in an instance, where the local declaration must
5413 -- also hide the name of the corresponding package renaming.
5414 -- We check explicitly for a package declared by a renaming,
5415 -- whose renamed entity is an instance that is on the scope
5416 -- stack, and that contains a homonym in the same scope. Once
5417 -- we have found it, we know that the package renaming is not
5418 -- immediately visible, and that the identifier denotes the
5419 -- other entity (and its homonyms if overloaded).
5421 if Scope (E) = Scope (E2)
5422 and then Ekind (E) = E_Package
5423 and then Present (Renamed_Object (E))
5424 and then Is_Generic_Instance (Renamed_Object (E))
5425 and then In_Open_Scopes (Renamed_Object (E))
5426 and then Comes_From_Source (N)
5428 Set_Is_Immediately_Visible (E, False);
5432 for J in Level + 1 .. Scope_Stack.Last loop
5433 if Scope_Stack.Table (J).Entity = Scope (E2)
5434 or else Scope_Stack.Table (J).Entity = E2
5447 -- At the end of that loop, E is the innermost immediately
5448 -- visible entity, so we are all set.
5451 -- Come here with entity found, and stored in E
5455 -- Check violation of No_Wide_Characters restriction
5457 Check_Wide_Character_Restriction (E, N);
5459 -- When distribution features are available (Get_PCS_Name /=
5460 -- Name_No_DSA), a remote access-to-subprogram type is converted
5461 -- into a record type holding whatever information is needed to
5462 -- perform a remote call on an RCI subprogram. In that case we
5463 -- rewrite any occurrence of the RAS type into the equivalent record
5464 -- type here. 'Access attribute references and RAS dereferences are
5465 -- then implemented using specific TSSs. However when distribution is
5466 -- not available (case of Get_PCS_Name = Name_No_DSA), we bypass the
5467 -- generation of these TSSs, and we must keep the RAS type in its
5468 -- original access-to-subprogram form (since all calls through a
5469 -- value of such type will be local anyway in the absence of a PCS).
5471 if Comes_From_Source (N)
5472 and then Is_Remote_Access_To_Subprogram_Type (E)
5473 and then Ekind (E) = E_Access_Subprogram_Type
5474 and then Expander_Active
5475 and then Get_PCS_Name /= Name_No_DSA
5477 Rewrite (N, New_Occurrence_Of (Equivalent_Type (E), Sloc (N)));
5481 -- Set the entity. Note that the reason we call Set_Entity for the
5482 -- overloadable case, as opposed to Set_Entity_With_Checks is
5483 -- that in the overloaded case, the initial call can set the wrong
5484 -- homonym. The call that sets the right homonym is in Sem_Res and
5485 -- that call does use Set_Entity_With_Checks, so we don't miss
5488 if Is_Overloadable (E) then
5491 Set_Entity_With_Checks (N, E);
5497 Set_Etype (N, Get_Full_View (Etype (E)));
5500 if Debug_Flag_E then
5501 Write_Str (" found ");
5502 Write_Entity_Info (E, " ");
5505 -- If the Ekind of the entity is Void, it means that all homonyms
5506 -- are hidden from all visibility (RM 8.3(5,14-20)). However, this
5507 -- test is skipped if the current scope is a record and the name is
5508 -- a pragma argument expression (case of Atomic and Volatile pragmas
5509 -- and possibly other similar pragmas added later, which are allowed
5510 -- to reference components in the current record).
5512 if Ekind (E) = E_Void
5514 (not Is_Record_Type (Current_Scope)
5515 or else Nkind (Parent (N)) /= N_Pragma_Argument_Association)
5517 Premature_Usage (N);
5519 -- If the entity is overloadable, collect all interpretations of the
5520 -- name for subsequent overload resolution. We optimize a bit here to
5521 -- do this only if we have an overloadable entity that is not on its
5522 -- own on the homonym chain.
5524 elsif Is_Overloadable (E)
5525 and then (Present (Homonym (E)) or else Current_Entity (N) /= E)
5527 Collect_Interps (N);
5529 -- If no homonyms were visible, the entity is unambiguous
5531 if not Is_Overloaded (N) then
5532 if not Is_Actual_Parameter then
5533 Generate_Reference (E, N);
5537 -- Case of non-overloadable entity, set the entity providing that
5538 -- we do not have the case of a discriminant reference within a
5539 -- default expression. Such references are replaced with the
5540 -- corresponding discriminal, which is the formal corresponding to
5541 -- to the discriminant in the initialization procedure.
5544 -- Entity is unambiguous, indicate that it is referenced here
5546 -- For a renaming of an object, always generate simple reference,
5547 -- we don't try to keep track of assignments in this case, except
5548 -- in SPARK mode where renamings are traversed for generating
5549 -- local effects of subprograms.
5552 and then Present (Renamed_Object (E))
5553 and then not GNATprove_Mode
5555 Generate_Reference (E, N);
5557 -- If the renamed entity is a private protected component,
5558 -- reference the original component as well. This needs to be
5559 -- done because the private renamings are installed before any
5560 -- analysis has occurred. Reference to a private component will
5561 -- resolve to the renaming and the original component will be
5562 -- left unreferenced, hence the following.
5564 if Is_Prival (E) then
5565 Generate_Reference (Prival_Link (E), N);
5568 -- One odd case is that we do not want to set the Referenced flag
5569 -- if the entity is a label, and the identifier is the label in
5570 -- the source, since this is not a reference from the point of
5571 -- view of the user.
5573 elsif Nkind (Parent (N)) = N_Label then
5575 R : constant Boolean := Referenced (E);
5578 -- Generate reference unless this is an actual parameter
5579 -- (see comment below)
5581 if Is_Actual_Parameter then
5582 Generate_Reference (E, N);
5583 Set_Referenced (E, R);
5587 -- Normal case, not a label: generate reference
5590 if not Is_Actual_Parameter then
5592 -- Package or generic package is always a simple reference
5594 if Ekind_In (E, E_Package, E_Generic_Package) then
5595 Generate_Reference (E, N, 'r');
5597 -- Else see if we have a left hand side
5602 Generate_Reference (E, N, 'm');
5605 Generate_Reference (E, N, 'r');
5607 -- If we don't know now, generate reference later
5610 Deferred_References.Append ((E, N));
5616 Set_Entity_Or_Discriminal (N, E);
5618 -- The name may designate a generalized reference, in which case
5619 -- the dereference interpretation will be included. Context is
5620 -- one in which a name is legal.
5622 if Ada_Version >= Ada_2012
5624 (Nkind (Parent (N)) in N_Subexpr
5625 or else Nkind_In (Parent (N), N_Assignment_Statement,
5626 N_Object_Declaration,
5627 N_Parameter_Association))
5629 Check_Implicit_Dereference (N, Etype (E));
5634 -- Come here with entity set
5637 Check_Restriction_No_Use_Of_Entity (N);
5638 end Find_Direct_Name;
5640 ------------------------
5641 -- Find_Expanded_Name --
5642 ------------------------
5644 -- This routine searches the homonym chain of the entity until it finds
5645 -- an entity declared in the scope denoted by the prefix. If the entity
5646 -- is private, it may nevertheless be immediately visible, if we are in
5647 -- the scope of its declaration.
5649 procedure Find_Expanded_Name (N : Node_Id) is
5650 function In_Abstract_View_Pragma (Nod : Node_Id) return Boolean;
5651 -- Determine whether expanded name Nod appears within a pragma which is
5652 -- a suitable context for an abstract view of a state or variable. The
5653 -- following pragmas fall in this category:
5660 -- In addition, pragma Abstract_State is also considered suitable even
5661 -- though it is an illegal context for an abstract view as this allows
5662 -- for proper resolution of abstract views of variables. This illegal
5663 -- context is later flagged in the analysis of indicator Part_Of.
5665 -----------------------------
5666 -- In_Abstract_View_Pragma --
5667 -----------------------------
5669 function In_Abstract_View_Pragma (Nod : Node_Id) return Boolean is
5673 -- Climb the parent chain looking for a pragma
5676 while Present (Par) loop
5677 if Nkind (Par) = N_Pragma then
5678 if Nam_In (Pragma_Name (Par), Name_Abstract_State,
5682 Name_Refined_Depends,
5683 Name_Refined_Global)
5687 -- Otherwise the pragma is not a legal context for an abstract
5694 -- Prevent the search from going too far
5696 elsif Is_Body_Or_Package_Declaration (Par) then
5700 Par := Parent (Par);
5704 end In_Abstract_View_Pragma;
5708 Selector : constant Node_Id := Selector_Name (N);
5709 Candidate : Entity_Id := Empty;
5713 -- Start of processing for Find_Expanded_Name
5716 P_Name := Entity (Prefix (N));
5718 -- If the prefix is a renamed package, look for the entity in the
5719 -- original package.
5721 if Ekind (P_Name) = E_Package
5722 and then Present (Renamed_Object (P_Name))
5724 P_Name := Renamed_Object (P_Name);
5726 -- Rewrite node with entity field pointing to renamed object
5728 Rewrite (Prefix (N), New_Copy (Prefix (N)));
5729 Set_Entity (Prefix (N), P_Name);
5731 -- If the prefix is an object of a concurrent type, look for
5732 -- the entity in the associated task or protected type.
5734 elsif Is_Concurrent_Type (Etype (P_Name)) then
5735 P_Name := Etype (P_Name);
5738 Id := Current_Entity (Selector);
5741 Is_New_Candidate : Boolean;
5744 while Present (Id) loop
5745 if Scope (Id) = P_Name then
5747 Is_New_Candidate := True;
5749 -- Handle abstract views of states and variables. These are
5750 -- acceptable candidates only when the reference to the view
5751 -- appears in certain pragmas.
5753 if Ekind (Id) = E_Abstract_State
5754 and then From_Limited_With (Id)
5755 and then Present (Non_Limited_View (Id))
5757 if In_Abstract_View_Pragma (N) then
5758 Candidate := Non_Limited_View (Id);
5759 Is_New_Candidate := True;
5761 -- Hide the candidate because it is not used in a proper
5766 Is_New_Candidate := False;
5770 -- Ada 2005 (AI-217): Handle shadow entities associated with
5771 -- types declared in limited-withed nested packages. We don't need
5772 -- to handle E_Incomplete_Subtype entities because the entities
5773 -- in the limited view are always E_Incomplete_Type and
5774 -- E_Class_Wide_Type entities (see Build_Limited_Views).
5776 -- Regarding the expression used to evaluate the scope, it
5777 -- is important to note that the limited view also has shadow
5778 -- entities associated nested packages. For this reason the
5779 -- correct scope of the entity is the scope of the real entity.
5780 -- The non-limited view may itself be incomplete, in which case
5781 -- get the full view if available.
5783 elsif Ekind_In (Id, E_Incomplete_Type, E_Class_Wide_Type)
5784 and then From_Limited_With (Id)
5785 and then Present (Non_Limited_View (Id))
5786 and then Scope (Non_Limited_View (Id)) = P_Name
5788 Candidate := Get_Full_View (Non_Limited_View (Id));
5789 Is_New_Candidate := True;
5792 Is_New_Candidate := False;
5795 if Is_New_Candidate then
5797 -- If entity is a child unit, either it is a visible child of
5798 -- the prefix, or we are in the body of a generic prefix, as
5799 -- will happen when a child unit is instantiated in the body
5800 -- of a generic parent. This is because the instance body does
5801 -- not restore the full compilation context, given that all
5802 -- non-local references have been captured.
5804 if Is_Child_Unit (Id) or else P_Name = Standard_Standard then
5805 exit when Is_Visible_Lib_Unit (Id)
5806 or else (Is_Child_Unit (Id)
5807 and then In_Open_Scopes (Scope (Id))
5808 and then In_Instance_Body);
5810 exit when not Is_Hidden (Id);
5813 exit when Is_Immediately_Visible (Id);
5821 and then Ekind_In (P_Name, E_Procedure, E_Function)
5822 and then Is_Generic_Instance (P_Name)
5824 -- Expanded name denotes entity in (instance of) generic subprogram.
5825 -- The entity may be in the subprogram instance, or may denote one of
5826 -- the formals, which is declared in the enclosing wrapper package.
5828 P_Name := Scope (P_Name);
5830 Id := Current_Entity (Selector);
5831 while Present (Id) loop
5832 exit when Scope (Id) = P_Name;
5837 if No (Id) or else Chars (Id) /= Chars (Selector) then
5838 Set_Etype (N, Any_Type);
5840 -- If we are looking for an entity defined in System, try to find it
5841 -- in the child package that may have been provided as an extension
5842 -- to System. The Extend_System pragma will have supplied the name of
5843 -- the extension, which may have to be loaded.
5845 if Chars (P_Name) = Name_System
5846 and then Scope (P_Name) = Standard_Standard
5847 and then Present (System_Extend_Unit)
5848 and then Present_System_Aux (N)
5850 Set_Entity (Prefix (N), System_Aux_Id);
5851 Find_Expanded_Name (N);
5854 -- There is an implicit instance of the predefined operator in
5855 -- the given scope. The operator entity is defined in Standard.
5856 -- Has_Implicit_Operator makes the node into an Expanded_Name.
5858 elsif Nkind (Selector) = N_Operator_Symbol
5859 and then Has_Implicit_Operator (N)
5863 -- If there is no literal defined in the scope denoted by the
5864 -- prefix, the literal may belong to (a type derived from)
5865 -- Standard_Character, for which we have no explicit literals.
5867 elsif Nkind (Selector) = N_Character_Literal
5868 and then Has_Implicit_Character_Literal (N)
5873 -- If the prefix is a single concurrent object, use its name in
5874 -- the error message, rather than that of the anonymous type.
5876 if Is_Concurrent_Type (P_Name)
5877 and then Is_Internal_Name (Chars (P_Name))
5879 Error_Msg_Node_2 := Entity (Prefix (N));
5881 Error_Msg_Node_2 := P_Name;
5884 if P_Name = System_Aux_Id then
5885 P_Name := Scope (P_Name);
5886 Set_Entity (Prefix (N), P_Name);
5889 if Present (Candidate) then
5891 -- If we know that the unit is a child unit we can give a more
5892 -- accurate error message.
5894 if Is_Child_Unit (Candidate) then
5896 -- If the candidate is a private child unit and we are in
5897 -- the visible part of a public unit, specialize the error
5898 -- message. There might be a private with_clause for it,
5899 -- but it is not currently active.
5901 if Is_Private_Descendant (Candidate)
5902 and then Ekind (Current_Scope) = E_Package
5903 and then not In_Private_Part (Current_Scope)
5904 and then not Is_Private_Descendant (Current_Scope)
5907 ("private child unit& is not visible here", Selector);
5909 -- Normal case where we have a missing with for a child unit
5912 Error_Msg_Qual_Level := 99;
5913 Error_Msg_NE -- CODEFIX
5914 ("missing `WITH &;`", Selector, Candidate);
5915 Error_Msg_Qual_Level := 0;
5918 -- Here we don't know that this is a child unit
5921 Error_Msg_NE ("& is not a visible entity of&", N, Selector);
5925 -- Within the instantiation of a child unit, the prefix may
5926 -- denote the parent instance, but the selector has the name
5927 -- of the original child. That is to say, when A.B appears
5928 -- within an instantiation of generic child unit B, the scope
5929 -- stack includes an instance of A (P_Name) and an instance
5930 -- of B under some other name. We scan the scope to find this
5931 -- child instance, which is the desired entity.
5932 -- Note that the parent may itself be a child instance, if
5933 -- the reference is of the form A.B.C, in which case A.B has
5934 -- already been rewritten with the proper entity.
5936 if In_Open_Scopes (P_Name)
5937 and then Is_Generic_Instance (P_Name)
5940 Gen_Par : constant Entity_Id :=
5941 Generic_Parent (Specification
5942 (Unit_Declaration_Node (P_Name)));
5943 S : Entity_Id := Current_Scope;
5947 for J in reverse 0 .. Scope_Stack.Last loop
5948 S := Scope_Stack.Table (J).Entity;
5950 exit when S = Standard_Standard;
5952 if Ekind_In (S, E_Function,
5957 Generic_Parent (Specification
5958 (Unit_Declaration_Node (S)));
5960 -- Check that P is a generic child of the generic
5961 -- parent of the prefix.
5964 and then Chars (P) = Chars (Selector)
5965 and then Scope (P) = Gen_Par
5976 -- If this is a selection from Ada, System or Interfaces, then
5977 -- we assume a missing with for the corresponding package.
5979 if Is_Known_Unit (N) then
5980 if not Error_Posted (N) then
5981 Error_Msg_Node_2 := Selector;
5982 Error_Msg_N -- CODEFIX
5983 ("missing `WITH &.&;`", Prefix (N));
5986 -- If this is a selection from a dummy package, then suppress
5987 -- the error message, of course the entity is missing if the
5988 -- package is missing.
5990 elsif Sloc (Error_Msg_Node_2) = No_Location then
5993 -- Here we have the case of an undefined component
5996 -- The prefix may hide a homonym in the context that
5997 -- declares the desired entity. This error can use a
5998 -- specialized message.
6000 if In_Open_Scopes (P_Name) then
6002 H : constant Entity_Id := Homonym (P_Name);
6006 and then Is_Compilation_Unit (H)
6008 (Is_Immediately_Visible (H)
6009 or else Is_Visible_Lib_Unit (H))
6011 Id := First_Entity (H);
6012 while Present (Id) loop
6013 if Chars (Id) = Chars (Selector) then
6014 Error_Msg_Qual_Level := 99;
6015 Error_Msg_Name_1 := Chars (Selector);
6017 ("% not declared in&", N, P_Name);
6019 ("\use fully qualified name starting with "
6020 & "Standard to make& visible", N, H);
6021 Error_Msg_Qual_Level := 0;
6029 -- If not found, standard error message
6031 Error_Msg_NE ("& not declared in&", N, Selector);
6037 Error_Msg_NE ("& not declared in&", N, Selector);
6040 -- Check for misspelling of some entity in prefix
6042 Id := First_Entity (P_Name);
6043 while Present (Id) loop
6044 if Is_Bad_Spelling_Of (Chars (Id), Chars (Selector))
6045 and then not Is_Internal_Name (Chars (Id))
6047 Error_Msg_NE -- CODEFIX
6048 ("possible misspelling of&", Selector, Id);
6055 -- Specialize the message if this may be an instantiation
6056 -- of a child unit that was not mentioned in the context.
6058 if Nkind (Parent (N)) = N_Package_Instantiation
6059 and then Is_Generic_Instance (Entity (Prefix (N)))
6060 and then Is_Compilation_Unit
6061 (Generic_Parent (Parent (Entity (Prefix (N)))))
6063 Error_Msg_Node_2 := Selector;
6064 Error_Msg_N -- CODEFIX
6065 ("\missing `WITH &.&;`", Prefix (N));
6075 if Comes_From_Source (N)
6076 and then Is_Remote_Access_To_Subprogram_Type (Id)
6077 and then Ekind (Id) = E_Access_Subprogram_Type
6078 and then Present (Equivalent_Type (Id))
6080 -- If we are not actually generating distribution code (i.e. the
6081 -- current PCS is the dummy non-distributed version), then the
6082 -- Equivalent_Type will be missing, and Id should be treated as
6083 -- a regular access-to-subprogram type.
6085 Id := Equivalent_Type (Id);
6086 Set_Chars (Selector, Chars (Id));
6089 -- Ada 2005 (AI-50217): Check usage of entities in limited withed units
6091 if Ekind (P_Name) = E_Package and then From_Limited_With (P_Name) then
6092 if From_Limited_With (Id)
6093 or else Is_Type (Id)
6094 or else Ekind (Id) = E_Package
6099 ("limited withed package can only be used to access "
6100 & "incomplete types", N);
6104 if Is_Task_Type (P_Name)
6105 and then ((Ekind (Id) = E_Entry
6106 and then Nkind (Parent (N)) /= N_Attribute_Reference)
6108 (Ekind (Id) = E_Entry_Family
6110 Nkind (Parent (Parent (N))) /= N_Attribute_Reference))
6112 -- If both the task type and the entry are in scope, this may still
6113 -- be the expanded name of an entry formal.
6115 if In_Open_Scopes (Id)
6116 and then Nkind (Parent (N)) = N_Selected_Component
6121 -- It is an entry call after all, either to the current task
6122 -- (which will deadlock) or to an enclosing task.
6124 Analyze_Selected_Component (N);
6129 Change_Selected_Component_To_Expanded_Name (N);
6131 -- Set appropriate type
6133 if Is_Type (Id) then
6136 Set_Etype (N, Get_Full_View (Etype (Id)));
6139 -- Do style check and generate reference, but skip both steps if this
6140 -- entity has homonyms, since we may not have the right homonym set yet.
6141 -- The proper homonym will be set during the resolve phase.
6143 if Has_Homonym (Id) then
6147 Set_Entity_Or_Discriminal (N, Id);
6151 Generate_Reference (Id, N, 'm');
6153 Generate_Reference (Id, N, 'r');
6155 Deferred_References.Append ((Id, N));
6159 -- Check for violation of No_Wide_Characters
6161 Check_Wide_Character_Restriction (Id, N);
6163 -- If the Ekind of the entity is Void, it means that all homonyms are
6164 -- hidden from all visibility (RM 8.3(5,14-20)).
6166 if Ekind (Id) = E_Void then
6167 Premature_Usage (N);
6169 elsif Is_Overloadable (Id) and then Present (Homonym (Id)) then
6171 H : Entity_Id := Homonym (Id);
6174 while Present (H) loop
6175 if Scope (H) = Scope (Id)
6176 and then (not Is_Hidden (H)
6177 or else Is_Immediately_Visible (H))
6179 Collect_Interps (N);
6186 -- If an extension of System is present, collect possible explicit
6187 -- overloadings declared in the extension.
6189 if Chars (P_Name) = Name_System
6190 and then Scope (P_Name) = Standard_Standard
6191 and then Present (System_Extend_Unit)
6192 and then Present_System_Aux (N)
6194 H := Current_Entity (Id);
6196 while Present (H) loop
6197 if Scope (H) = System_Aux_Id then
6198 Add_One_Interp (N, H, Etype (H));
6207 if Nkind (Selector_Name (N)) = N_Operator_Symbol
6208 and then Scope (Id) /= Standard_Standard
6210 -- In addition to user-defined operators in the given scope, there
6211 -- may be an implicit instance of the predefined operator. The
6212 -- operator (defined in Standard) is found in Has_Implicit_Operator,
6213 -- and added to the interpretations. Procedure Add_One_Interp will
6214 -- determine which hides which.
6216 if Has_Implicit_Operator (N) then
6221 -- If there is a single interpretation for N we can generate a
6222 -- reference to the unique entity found.
6224 if Is_Overloadable (Id) and then not Is_Overloaded (N) then
6225 Generate_Reference (Id, N);
6227 end Find_Expanded_Name;
6229 -------------------------
6230 -- Find_Renamed_Entity --
6231 -------------------------
6233 function Find_Renamed_Entity
6237 Is_Actual : Boolean := False) return Entity_Id
6240 I1 : Interp_Index := 0; -- Suppress junk warnings
6246 function Is_Visible_Operation (Op : Entity_Id) return Boolean;
6247 -- If the renamed entity is an implicit operator, check whether it is
6248 -- visible because its operand type is properly visible. This check
6249 -- applies to explicit renamed entities that appear in the source in a
6250 -- renaming declaration or a formal subprogram instance, but not to
6251 -- default generic actuals with a name.
6253 function Report_Overload return Entity_Id;
6254 -- List possible interpretations, and specialize message in the
6255 -- case of a generic actual.
6257 function Within (Inner, Outer : Entity_Id) return Boolean;
6258 -- Determine whether a candidate subprogram is defined within the
6259 -- enclosing instance. If yes, it has precedence over outer candidates.
6261 --------------------------
6262 -- Is_Visible_Operation --
6263 --------------------------
6265 function Is_Visible_Operation (Op : Entity_Id) return Boolean is
6271 if Ekind (Op) /= E_Operator
6272 or else Scope (Op) /= Standard_Standard
6273 or else (In_Instance
6274 and then (not Is_Actual
6275 or else Present (Enclosing_Instance)))
6280 -- For a fixed point type operator, check the resulting type,
6281 -- because it may be a mixed mode integer * fixed operation.
6283 if Present (Next_Formal (First_Formal (New_S)))
6284 and then Is_Fixed_Point_Type (Etype (New_S))
6286 Typ := Etype (New_S);
6288 Typ := Etype (First_Formal (New_S));
6291 Btyp := Base_Type (Typ);
6293 if Nkind (Nam) /= N_Expanded_Name then
6294 return (In_Open_Scopes (Scope (Btyp))
6295 or else Is_Potentially_Use_Visible (Btyp)
6296 or else In_Use (Btyp)
6297 or else In_Use (Scope (Btyp)));
6300 Scop := Entity (Prefix (Nam));
6302 if Ekind (Scop) = E_Package
6303 and then Present (Renamed_Object (Scop))
6305 Scop := Renamed_Object (Scop);
6308 -- Operator is visible if prefix of expanded name denotes
6309 -- scope of type, or else type is defined in System_Aux
6310 -- and the prefix denotes System.
6312 return Scope (Btyp) = Scop
6313 or else (Scope (Btyp) = System_Aux_Id
6314 and then Scope (Scope (Btyp)) = Scop);
6317 end Is_Visible_Operation;
6323 function Within (Inner, Outer : Entity_Id) return Boolean is
6327 Sc := Scope (Inner);
6328 while Sc /= Standard_Standard loop
6339 ---------------------
6340 -- Report_Overload --
6341 ---------------------
6343 function Report_Overload return Entity_Id is
6346 Error_Msg_NE -- CODEFIX
6347 ("ambiguous actual subprogram&, " &
6348 "possible interpretations:", N, Nam);
6350 Error_Msg_N -- CODEFIX
6351 ("ambiguous subprogram, " &
6352 "possible interpretations:", N);
6355 List_Interps (Nam, N);
6357 end Report_Overload;
6359 -- Start of processing for Find_Renamed_Entity
6363 Candidate_Renaming := Empty;
6365 if Is_Overloaded (Nam) then
6366 Get_First_Interp (Nam, Ind, It);
6367 while Present (It.Nam) loop
6368 if Entity_Matches_Spec (It.Nam, New_S)
6369 and then Is_Visible_Operation (It.Nam)
6371 if Old_S /= Any_Id then
6373 -- Note: The call to Disambiguate only happens if a
6374 -- previous interpretation was found, in which case I1
6375 -- has received a value.
6377 It1 := Disambiguate (Nam, I1, Ind, Etype (Old_S));
6379 if It1 = No_Interp then
6380 Inst := Enclosing_Instance;
6382 if Present (Inst) then
6383 if Within (It.Nam, Inst) then
6384 if Within (Old_S, Inst) then
6386 -- Choose the innermost subprogram, which would
6387 -- have hidden the outer one in the generic.
6389 if Scope_Depth (It.Nam) <
6398 elsif Within (Old_S, Inst) then
6402 return Report_Overload;
6405 -- If not within an instance, ambiguity is real
6408 return Report_Overload;
6422 Present (First_Formal (It.Nam))
6423 and then Present (First_Formal (New_S))
6424 and then (Base_Type (Etype (First_Formal (It.Nam))) =
6425 Base_Type (Etype (First_Formal (New_S))))
6427 Candidate_Renaming := It.Nam;
6430 Get_Next_Interp (Ind, It);
6433 Set_Entity (Nam, Old_S);
6435 if Old_S /= Any_Id then
6436 Set_Is_Overloaded (Nam, False);
6439 -- Non-overloaded case
6442 if Is_Actual and then Present (Enclosing_Instance) then
6443 Old_S := Entity (Nam);
6445 elsif Entity_Matches_Spec (Entity (Nam), New_S) then
6446 Candidate_Renaming := New_S;
6448 if Is_Visible_Operation (Entity (Nam)) then
6449 Old_S := Entity (Nam);
6452 elsif Present (First_Formal (Entity (Nam)))
6453 and then Present (First_Formal (New_S))
6454 and then (Base_Type (Etype (First_Formal (Entity (Nam)))) =
6455 Base_Type (Etype (First_Formal (New_S))))
6457 Candidate_Renaming := Entity (Nam);
6462 end Find_Renamed_Entity;
6464 -----------------------------
6465 -- Find_Selected_Component --
6466 -----------------------------
6468 procedure Find_Selected_Component (N : Node_Id) is
6469 P : constant Node_Id := Prefix (N);
6472 -- Entity denoted by prefix
6479 function Available_Subtype return Boolean;
6480 -- A small optimization: if the prefix is constrained and the component
6481 -- is an array type we may already have a usable subtype for it, so we
6482 -- can use it rather than generating a new one, because the bounds
6483 -- will be the values of the discriminants and not discriminant refs.
6484 -- This simplifies value tracing in GNATProve. For consistency, both
6485 -- the entity name and the subtype come from the constrained component.
6487 function Is_Reference_In_Subunit return Boolean;
6488 -- In a subunit, the scope depth is not a proper measure of hiding,
6489 -- because the context of the proper body may itself hide entities in
6490 -- parent units. This rare case requires inspecting the tree directly
6491 -- because the proper body is inserted in the main unit and its context
6492 -- is simply added to that of the parent.
6494 -----------------------
6495 -- Available_Subtype --
6496 -----------------------
6498 function Available_Subtype return Boolean is
6502 Comp := First_Entity (Etype (P));
6503 while Present (Comp) loop
6504 if Chars (Comp) = Chars (Selector_Name (N)) then
6505 Set_Etype (N, Etype (Comp));
6506 Set_Entity (Selector_Name (N), Comp);
6507 Set_Etype (Selector_Name (N), Etype (Comp));
6511 Next_Component (Comp);
6515 end Available_Subtype;
6517 -----------------------------
6518 -- Is_Reference_In_Subunit --
6519 -----------------------------
6521 function Is_Reference_In_Subunit return Boolean is
6523 Comp_Unit : Node_Id;
6527 while Present (Comp_Unit)
6528 and then Nkind (Comp_Unit) /= N_Compilation_Unit
6530 Comp_Unit := Parent (Comp_Unit);
6533 if No (Comp_Unit) or else Nkind (Unit (Comp_Unit)) /= N_Subunit then
6537 -- Now check whether the package is in the context of the subunit
6539 Clause := First (Context_Items (Comp_Unit));
6540 while Present (Clause) loop
6541 if Nkind (Clause) = N_With_Clause
6542 and then Entity (Name (Clause)) = P_Name
6547 Clause := Next (Clause);
6551 end Is_Reference_In_Subunit;
6553 -- Start of processing for Find_Selected_Component
6558 if Nkind (P) = N_Error then
6562 -- Selector name cannot be a character literal or an operator symbol in
6563 -- SPARK, except for the operator symbol in a renaming.
6565 if Restriction_Check_Required (SPARK_05) then
6566 if Nkind (Selector_Name (N)) = N_Character_Literal then
6567 Check_SPARK_05_Restriction
6568 ("character literal cannot be prefixed", N);
6569 elsif Nkind (Selector_Name (N)) = N_Operator_Symbol
6570 and then Nkind (Parent (N)) /= N_Subprogram_Renaming_Declaration
6572 Check_SPARK_05_Restriction
6573 ("operator symbol cannot be prefixed", N);
6577 -- If the selector already has an entity, the node has been constructed
6578 -- in the course of expansion, and is known to be valid. Do not verify
6579 -- that it is defined for the type (it may be a private component used
6580 -- in the expansion of record equality).
6582 if Present (Entity (Selector_Name (N))) then
6583 if No (Etype (N)) or else Etype (N) = Any_Type then
6585 Sel_Name : constant Node_Id := Selector_Name (N);
6586 Selector : constant Entity_Id := Entity (Sel_Name);
6590 Set_Etype (Sel_Name, Etype (Selector));
6592 if not Is_Entity_Name (P) then
6596 -- Build an actual subtype except for the first parameter
6597 -- of an init proc, where this actual subtype is by
6598 -- definition incorrect, since the object is uninitialized
6599 -- (and does not even have defined discriminants etc.)
6601 if Is_Entity_Name (P)
6602 and then Ekind (Entity (P)) = E_Function
6604 Nam := New_Copy (P);
6606 if Is_Overloaded (P) then
6607 Save_Interps (P, Nam);
6610 Rewrite (P, Make_Function_Call (Sloc (P), Name => Nam));
6612 Analyze_Selected_Component (N);
6615 elsif Ekind (Selector) = E_Component
6616 and then (not Is_Entity_Name (P)
6617 or else Chars (Entity (P)) /= Name_uInit)
6619 -- Check if we already have an available subtype we can use
6621 if Ekind (Etype (P)) = E_Record_Subtype
6622 and then Nkind (Parent (Etype (P))) = N_Subtype_Declaration
6623 and then Is_Array_Type (Etype (Selector))
6624 and then not Is_Packed (Etype (Selector))
6625 and then Available_Subtype
6629 -- Do not build the subtype when referencing components of
6630 -- dispatch table wrappers. Required to avoid generating
6631 -- elaboration code with HI runtimes.
6633 elsif RTU_Loaded (Ada_Tags)
6635 ((RTE_Available (RE_Dispatch_Table_Wrapper)
6636 and then Scope (Selector) =
6637 RTE (RE_Dispatch_Table_Wrapper))
6639 (RTE_Available (RE_No_Dispatch_Table_Wrapper)
6640 and then Scope (Selector) =
6641 RTE (RE_No_Dispatch_Table_Wrapper)))
6646 Build_Actual_Subtype_Of_Component
6647 (Etype (Selector), N);
6654 if No (C_Etype) then
6655 C_Etype := Etype (Selector);
6657 Insert_Action (N, C_Etype);
6658 C_Etype := Defining_Identifier (C_Etype);
6661 Set_Etype (N, C_Etype);
6664 -- If this is the name of an entry or protected operation, and
6665 -- the prefix is an access type, insert an explicit dereference,
6666 -- so that entry calls are treated uniformly.
6668 if Is_Access_Type (Etype (P))
6669 and then Is_Concurrent_Type (Designated_Type (Etype (P)))
6672 New_P : constant Node_Id :=
6673 Make_Explicit_Dereference (Sloc (P),
6674 Prefix => Relocate_Node (P));
6677 Set_Etype (P, Designated_Type (Etype (Prefix (P))));
6681 -- If the selected component appears within a default expression
6682 -- and it has an actual subtype, the pre-analysis has not yet
6683 -- completed its analysis, because Insert_Actions is disabled in
6684 -- that context. Within the init proc of the enclosing type we
6685 -- must complete this analysis, if an actual subtype was created.
6687 elsif Inside_Init_Proc then
6689 Typ : constant Entity_Id := Etype (N);
6690 Decl : constant Node_Id := Declaration_Node (Typ);
6692 if Nkind (Decl) = N_Subtype_Declaration
6693 and then not Analyzed (Decl)
6694 and then Is_List_Member (Decl)
6695 and then No (Parent (Decl))
6698 Insert_Action (N, Decl);
6705 elsif Is_Entity_Name (P) then
6706 P_Name := Entity (P);
6708 -- The prefix may denote an enclosing type which is the completion
6709 -- of an incomplete type declaration.
6711 if Is_Type (P_Name) then
6712 Set_Entity (P, Get_Full_View (P_Name));
6713 Set_Etype (P, Entity (P));
6714 P_Name := Entity (P);
6717 P_Type := Base_Type (Etype (P));
6719 if Debug_Flag_E then
6720 Write_Str ("Found prefix type to be ");
6721 Write_Entity_Info (P_Type, " "); Write_Eol;
6724 -- The designated type may be a limited view with no components.
6725 -- Check whether the non-limited view is available, because in some
6726 -- cases this will not be set when installing the context.
6728 if Is_Access_Type (P_Type) then
6730 D : constant Entity_Id := Directly_Designated_Type (P_Type);
6732 if Is_Incomplete_Type (D)
6733 and then From_Limited_With (D)
6734 and then Present (Non_Limited_View (D))
6736 Set_Directly_Designated_Type (P_Type, Non_Limited_View (D));
6741 -- First check for components of a record object (not the
6742 -- result of a call, which is handled below).
6744 if Is_Appropriate_For_Record (P_Type)
6745 and then not Is_Overloadable (P_Name)
6746 and then not Is_Type (P_Name)
6748 -- Selected component of record. Type checking will validate
6749 -- name of selector.
6751 -- ??? Could we rewrite an implicit dereference into an explicit
6754 Analyze_Selected_Component (N);
6756 -- Reference to type name in predicate/invariant expression
6758 elsif Is_Appropriate_For_Entry_Prefix (P_Type)
6759 and then not In_Open_Scopes (P_Name)
6760 and then (not Is_Concurrent_Type (Etype (P_Name))
6761 or else not In_Open_Scopes (Etype (P_Name)))
6763 -- Call to protected operation or entry. Type checking is
6764 -- needed on the prefix.
6766 Analyze_Selected_Component (N);
6768 elsif (In_Open_Scopes (P_Name)
6769 and then Ekind (P_Name) /= E_Void
6770 and then not Is_Overloadable (P_Name))
6771 or else (Is_Concurrent_Type (Etype (P_Name))
6772 and then In_Open_Scopes (Etype (P_Name)))
6774 -- Prefix denotes an enclosing loop, block, or task, i.e. an
6775 -- enclosing construct that is not a subprogram or accept.
6777 Find_Expanded_Name (N);
6779 elsif Ekind (P_Name) = E_Package then
6780 Find_Expanded_Name (N);
6782 elsif Is_Overloadable (P_Name) then
6784 -- The subprogram may be a renaming (of an enclosing scope) as
6785 -- in the case of the name of the generic within an instantiation.
6787 if Ekind_In (P_Name, E_Procedure, E_Function)
6788 and then Present (Alias (P_Name))
6789 and then Is_Generic_Instance (Alias (P_Name))
6791 P_Name := Alias (P_Name);
6794 if Is_Overloaded (P) then
6796 -- The prefix must resolve to a unique enclosing construct
6799 Found : Boolean := False;
6804 Get_First_Interp (P, Ind, It);
6805 while Present (It.Nam) loop
6806 if In_Open_Scopes (It.Nam) then
6809 "prefix must be unique enclosing scope", N);
6810 Set_Entity (N, Any_Id);
6811 Set_Etype (N, Any_Type);
6820 Get_Next_Interp (Ind, It);
6825 if In_Open_Scopes (P_Name) then
6826 Set_Entity (P, P_Name);
6827 Set_Is_Overloaded (P, False);
6828 Find_Expanded_Name (N);
6831 -- If no interpretation as an expanded name is possible, it
6832 -- must be a selected component of a record returned by a
6833 -- function call. Reformat prefix as a function call, the rest
6834 -- is done by type resolution.
6836 -- Error if the prefix is procedure or entry, as is P.X
6838 if Ekind (P_Name) /= E_Function
6840 (not Is_Overloaded (P)
6841 or else Nkind (Parent (N)) = N_Procedure_Call_Statement)
6843 -- Prefix may mention a package that is hidden by a local
6844 -- declaration: let the user know. Scan the full homonym
6845 -- chain, the candidate package may be anywhere on it.
6847 if Present (Homonym (Current_Entity (P_Name))) then
6848 P_Name := Current_Entity (P_Name);
6850 while Present (P_Name) loop
6851 exit when Ekind (P_Name) = E_Package;
6852 P_Name := Homonym (P_Name);
6855 if Present (P_Name) then
6856 if not Is_Reference_In_Subunit then
6857 Error_Msg_Sloc := Sloc (Entity (Prefix (N)));
6859 ("package& is hidden by declaration#", N, P_Name);
6862 Set_Entity (Prefix (N), P_Name);
6863 Find_Expanded_Name (N);
6867 P_Name := Entity (Prefix (N));
6872 ("invalid prefix in selected component&", N, P_Name);
6873 Change_Selected_Component_To_Expanded_Name (N);
6874 Set_Entity (N, Any_Id);
6875 Set_Etype (N, Any_Type);
6877 -- Here we have a function call, so do the reformatting
6880 Nam := New_Copy (P);
6881 Save_Interps (P, Nam);
6883 -- We use Replace here because this is one of those cases
6884 -- where the parser has missclassified the node, and we
6885 -- fix things up and then do the semantic analysis on the
6886 -- fixed up node. Normally we do this using one of the
6887 -- Sinfo.CN routines, but this is too tricky for that.
6889 -- Note that using Rewrite would be wrong, because we
6890 -- would have a tree where the original node is unanalyzed,
6891 -- and this violates the required interface for ASIS.
6894 Make_Function_Call (Sloc (P), Name => Nam));
6896 -- Now analyze the reformatted node
6899 Analyze_Selected_Component (N);
6903 -- Remaining cases generate various error messages
6906 -- Format node as expanded name, to avoid cascaded errors
6908 Change_Selected_Component_To_Expanded_Name (N);
6909 Set_Entity (N, Any_Id);
6910 Set_Etype (N, Any_Type);
6912 -- Issue error message, but avoid this if error issued already.
6913 -- Use identifier of prefix if one is available.
6915 if P_Name = Any_Id then
6918 -- It is not an error if the prefix is the current instance of
6919 -- type name, e.g. the expression of a type aspect, when it is
6920 -- analyzed for ASIS use.
6922 elsif Is_Entity_Name (P) and then Is_Current_Instance (P) then
6925 elsif Ekind (P_Name) = E_Void then
6926 Premature_Usage (P);
6928 elsif Nkind (P) /= N_Attribute_Reference then
6930 -- This may have been meant as a prefixed call to a primitive
6931 -- of an untagged type.
6934 F : constant Entity_Id :=
6935 Current_Entity (Selector_Name (N));
6938 and then Is_Overloadable (F)
6939 and then Present (First_Entity (F))
6940 and then Etype (First_Entity (F)) = Etype (P)
6941 and then not Is_Tagged_Type (Etype (P))
6944 ("prefixed call is only allowed for objects "
6945 & "of a tagged type", N);
6949 Error_Msg_N ("invalid prefix in selected component&", P);
6951 if Is_Access_Type (P_Type)
6952 and then Ekind (Designated_Type (P_Type)) = E_Incomplete_Type
6955 ("\dereference must not be of an incomplete type "
6956 & "(RM 3.10.1)", P);
6960 Error_Msg_N ("invalid prefix in selected component", P);
6964 -- Selector name is restricted in SPARK
6966 if Nkind (N) = N_Expanded_Name
6967 and then Restriction_Check_Required (SPARK_05)
6969 if Is_Subprogram (P_Name) then
6970 Check_SPARK_05_Restriction
6971 ("prefix of expanded name cannot be a subprogram", P);
6972 elsif Ekind (P_Name) = E_Loop then
6973 Check_SPARK_05_Restriction
6974 ("prefix of expanded name cannot be a loop statement", P);
6979 -- If prefix is not the name of an entity, it must be an expression,
6980 -- whose type is appropriate for a record. This is determined by
6983 Analyze_Selected_Component (N);
6986 Analyze_Dimension (N);
6987 end Find_Selected_Component;
6993 procedure Find_Type (N : Node_Id) is
7003 elsif Nkind (N) = N_Attribute_Reference then
7005 -- Class attribute. This is not valid in Ada 83 mode, but we do not
7006 -- need to enforce that at this point, since the declaration of the
7007 -- tagged type in the prefix would have been flagged already.
7009 if Attribute_Name (N) = Name_Class then
7010 Check_Restriction (No_Dispatch, N);
7011 Find_Type (Prefix (N));
7013 -- Propagate error from bad prefix
7015 if Etype (Prefix (N)) = Any_Type then
7016 Set_Entity (N, Any_Type);
7017 Set_Etype (N, Any_Type);
7021 T := Base_Type (Entity (Prefix (N)));
7023 -- Case where type is not known to be tagged. Its appearance in
7024 -- the prefix of the 'Class attribute indicates that the full view
7027 if not Is_Tagged_Type (T) then
7028 if Ekind (T) = E_Incomplete_Type then
7030 -- It is legal to denote the class type of an incomplete
7031 -- type. The full type will have to be tagged, of course.
7032 -- In Ada 2005 this usage is declared obsolescent, so we
7033 -- warn accordingly. This usage is only legal if the type
7034 -- is completed in the current scope, and not for a limited
7037 if Ada_Version >= Ada_2005 then
7039 -- Test whether the Available_View of a limited type view
7040 -- is tagged, since the limited view may not be marked as
7041 -- tagged if the type itself has an untagged incomplete
7042 -- type view in its package.
7044 if From_Limited_With (T)
7045 and then not Is_Tagged_Type (Available_View (T))
7048 ("prefix of Class attribute must be tagged", N);
7049 Set_Etype (N, Any_Type);
7050 Set_Entity (N, Any_Type);
7053 -- ??? This test is temporarily disabled (always
7054 -- False) because it causes an unwanted warning on
7055 -- GNAT sources (built with -gnatg, which includes
7056 -- Warn_On_Obsolescent_ Feature). Once this issue
7057 -- is cleared in the sources, it can be enabled.
7059 elsif Warn_On_Obsolescent_Feature and then False then
7061 ("applying 'Class to an untagged incomplete type"
7062 & " is an obsolescent feature (RM J.11)?r?", N);
7066 Set_Is_Tagged_Type (T);
7067 Set_Direct_Primitive_Operations (T, New_Elmt_List);
7068 Make_Class_Wide_Type (T);
7069 Set_Entity (N, Class_Wide_Type (T));
7070 Set_Etype (N, Class_Wide_Type (T));
7072 elsif Ekind (T) = E_Private_Type
7073 and then not Is_Generic_Type (T)
7074 and then In_Private_Part (Scope (T))
7076 -- The Class attribute can be applied to an untagged private
7077 -- type fulfilled by a tagged type prior to the full type
7078 -- declaration (but only within the parent package's private
7079 -- part). Create the class-wide type now and check that the
7080 -- full type is tagged later during its analysis. Note that
7081 -- we do not mark the private type as tagged, unlike the
7082 -- case of incomplete types, because the type must still
7083 -- appear untagged to outside units.
7085 if No (Class_Wide_Type (T)) then
7086 Make_Class_Wide_Type (T);
7089 Set_Entity (N, Class_Wide_Type (T));
7090 Set_Etype (N, Class_Wide_Type (T));
7093 -- Should we introduce a type Any_Tagged and use Wrong_Type
7094 -- here, it would be a bit more consistent???
7097 ("tagged type required, found}",
7098 Prefix (N), First_Subtype (T));
7099 Set_Entity (N, Any_Type);
7103 -- Case of tagged type
7106 if Is_Concurrent_Type (T) then
7107 if No (Corresponding_Record_Type (Entity (Prefix (N)))) then
7109 -- Previous error. Use current type, which at least
7110 -- provides some operations.
7112 C := Entity (Prefix (N));
7115 C := Class_Wide_Type
7116 (Corresponding_Record_Type (Entity (Prefix (N))));
7120 C := Class_Wide_Type (Entity (Prefix (N)));
7123 Set_Entity_With_Checks (N, C);
7124 Generate_Reference (C, N);
7128 -- Base attribute, not allowed in Ada 83
7130 elsif Attribute_Name (N) = Name_Base then
7131 Error_Msg_Name_1 := Name_Base;
7132 Check_SPARK_05_Restriction
7133 ("attribute% is only allowed as prefix of another attribute", N);
7135 if Ada_Version = Ada_83 and then Comes_From_Source (N) then
7137 ("(Ada 83) Base attribute not allowed in subtype mark", N);
7140 Find_Type (Prefix (N));
7141 Typ := Entity (Prefix (N));
7143 if Ada_Version >= Ada_95
7144 and then not Is_Scalar_Type (Typ)
7145 and then not Is_Generic_Type (Typ)
7148 ("prefix of Base attribute must be scalar type",
7151 elsif Warn_On_Redundant_Constructs
7152 and then Base_Type (Typ) = Typ
7154 Error_Msg_NE -- CODEFIX
7155 ("redundant attribute, & is its own base type?r?", N, Typ);
7158 T := Base_Type (Typ);
7160 -- Rewrite attribute reference with type itself (see similar
7161 -- processing in Analyze_Attribute, case Base). Preserve prefix
7162 -- if present, for other legality checks.
7164 if Nkind (Prefix (N)) = N_Expanded_Name then
7166 Make_Expanded_Name (Sloc (N),
7168 Prefix => New_Copy (Prefix (Prefix (N))),
7169 Selector_Name => New_Occurrence_Of (T, Sloc (N))));
7172 Rewrite (N, New_Occurrence_Of (T, Sloc (N)));
7179 elsif Attribute_Name (N) = Name_Stub_Type then
7181 -- This is handled in Analyze_Attribute
7185 -- All other attributes are invalid in a subtype mark
7188 Error_Msg_N ("invalid attribute in subtype mark", N);
7194 if Is_Entity_Name (N) then
7195 T_Name := Entity (N);
7197 Error_Msg_N ("subtype mark required in this context", N);
7198 Set_Etype (N, Any_Type);
7202 if T_Name = Any_Id or else Etype (N) = Any_Type then
7204 -- Undefined id. Make it into a valid type
7206 Set_Entity (N, Any_Type);
7208 elsif not Is_Type (T_Name)
7209 and then T_Name /= Standard_Void_Type
7211 Error_Msg_Sloc := Sloc (T_Name);
7212 Error_Msg_N ("subtype mark required in this context", N);
7213 Error_Msg_NE ("\\found & declared#", N, T_Name);
7214 Set_Entity (N, Any_Type);
7217 -- If the type is an incomplete type created to handle
7218 -- anonymous access components of a record type, then the
7219 -- incomplete type is the visible entity and subsequent
7220 -- references will point to it. Mark the original full
7221 -- type as referenced, to prevent spurious warnings.
7223 if Is_Incomplete_Type (T_Name)
7224 and then Present (Full_View (T_Name))
7225 and then not Comes_From_Source (T_Name)
7227 Set_Referenced (Full_View (T_Name));
7230 T_Name := Get_Full_View (T_Name);
7232 -- Ada 2005 (AI-251, AI-50217): Handle interfaces visible through
7233 -- limited-with clauses
7235 if From_Limited_With (T_Name)
7236 and then Ekind (T_Name) in Incomplete_Kind
7237 and then Present (Non_Limited_View (T_Name))
7238 and then Is_Interface (Non_Limited_View (T_Name))
7240 T_Name := Non_Limited_View (T_Name);
7243 if In_Open_Scopes (T_Name) then
7244 if Ekind (Base_Type (T_Name)) = E_Task_Type then
7246 -- In Ada 2005, a task name can be used in an access
7247 -- definition within its own body. It cannot be used
7248 -- in the discriminant part of the task declaration,
7249 -- nor anywhere else in the declaration because entries
7250 -- cannot have access parameters.
7252 if Ada_Version >= Ada_2005
7253 and then Nkind (Parent (N)) = N_Access_Definition
7255 Set_Entity (N, T_Name);
7256 Set_Etype (N, T_Name);
7258 if Has_Completion (T_Name) then
7263 ("task type cannot be used as type mark " &
7264 "within its own declaration", N);
7269 ("task type cannot be used as type mark " &
7270 "within its own spec or body", N);
7273 elsif Ekind (Base_Type (T_Name)) = E_Protected_Type then
7275 -- In Ada 2005, a protected name can be used in an access
7276 -- definition within its own body.
7278 if Ada_Version >= Ada_2005
7279 and then Nkind (Parent (N)) = N_Access_Definition
7281 Set_Entity (N, T_Name);
7282 Set_Etype (N, T_Name);
7287 ("protected type cannot be used as type mark " &
7288 "within its own spec or body", N);
7292 Error_Msg_N ("type declaration cannot refer to itself", N);
7295 Set_Etype (N, Any_Type);
7296 Set_Entity (N, Any_Type);
7297 Set_Error_Posted (T_Name);
7301 Set_Entity (N, T_Name);
7302 Set_Etype (N, T_Name);
7306 if Present (Etype (N)) and then Comes_From_Source (N) then
7307 if Is_Fixed_Point_Type (Etype (N)) then
7308 Check_Restriction (No_Fixed_Point, N);
7309 elsif Is_Floating_Point_Type (Etype (N)) then
7310 Check_Restriction (No_Floating_Point, N);
7313 -- A Ghost type must appear in a specific context
7315 if Is_Ghost_Entity (Etype (N)) then
7316 Check_Ghost_Context (Etype (N), N);
7321 ------------------------------------
7322 -- Has_Implicit_Character_Literal --
7323 ------------------------------------
7325 function Has_Implicit_Character_Literal (N : Node_Id) return Boolean is
7327 Found : Boolean := False;
7328 P : constant Entity_Id := Entity (Prefix (N));
7329 Priv_Id : Entity_Id := Empty;
7332 if Ekind (P) = E_Package and then not In_Open_Scopes (P) then
7333 Priv_Id := First_Private_Entity (P);
7336 if P = Standard_Standard then
7337 Change_Selected_Component_To_Expanded_Name (N);
7338 Rewrite (N, Selector_Name (N));
7340 Set_Etype (Original_Node (N), Standard_Character);
7344 Id := First_Entity (P);
7345 while Present (Id) and then Id /= Priv_Id loop
7346 if Is_Standard_Character_Type (Id) and then Is_Base_Type (Id) then
7348 -- We replace the node with the literal itself, resolve as a
7349 -- character, and set the type correctly.
7352 Change_Selected_Component_To_Expanded_Name (N);
7353 Rewrite (N, Selector_Name (N));
7356 Set_Etype (Original_Node (N), Id);
7360 -- More than one type derived from Character in given scope.
7361 -- Collect all possible interpretations.
7363 Add_One_Interp (N, Id, Id);
7371 end Has_Implicit_Character_Literal;
7373 ----------------------
7374 -- Has_Private_With --
7375 ----------------------
7377 function Has_Private_With (E : Entity_Id) return Boolean is
7378 Comp_Unit : constant Node_Id := Cunit (Current_Sem_Unit);
7382 Item := First (Context_Items (Comp_Unit));
7383 while Present (Item) loop
7384 if Nkind (Item) = N_With_Clause
7385 and then Private_Present (Item)
7386 and then Entity (Name (Item)) = E
7395 end Has_Private_With;
7397 ---------------------------
7398 -- Has_Implicit_Operator --
7399 ---------------------------
7401 function Has_Implicit_Operator (N : Node_Id) return Boolean is
7402 Op_Id : constant Name_Id := Chars (Selector_Name (N));
7403 P : constant Entity_Id := Entity (Prefix (N));
7405 Priv_Id : Entity_Id := Empty;
7407 procedure Add_Implicit_Operator
7409 Op_Type : Entity_Id := Empty);
7410 -- Add implicit interpretation to node N, using the type for which a
7411 -- predefined operator exists. If the operator yields a boolean type,
7412 -- the Operand_Type is implicitly referenced by the operator, and a
7413 -- reference to it must be generated.
7415 ---------------------------
7416 -- Add_Implicit_Operator --
7417 ---------------------------
7419 procedure Add_Implicit_Operator
7421 Op_Type : Entity_Id := Empty)
7423 Predef_Op : Entity_Id;
7426 Predef_Op := Current_Entity (Selector_Name (N));
7427 while Present (Predef_Op)
7428 and then Scope (Predef_Op) /= Standard_Standard
7430 Predef_Op := Homonym (Predef_Op);
7433 if Nkind (N) = N_Selected_Component then
7434 Change_Selected_Component_To_Expanded_Name (N);
7437 -- If the context is an unanalyzed function call, determine whether
7438 -- a binary or unary interpretation is required.
7440 if Nkind (Parent (N)) = N_Indexed_Component then
7442 Is_Binary_Call : constant Boolean :=
7444 (Next (First (Expressions (Parent (N)))));
7445 Is_Binary_Op : constant Boolean :=
7447 (Predef_Op) /= Last_Entity (Predef_Op);
7448 Predef_Op2 : constant Entity_Id := Homonym (Predef_Op);
7451 if Is_Binary_Call then
7452 if Is_Binary_Op then
7453 Add_One_Interp (N, Predef_Op, T);
7455 Add_One_Interp (N, Predef_Op2, T);
7459 if not Is_Binary_Op then
7460 Add_One_Interp (N, Predef_Op, T);
7462 Add_One_Interp (N, Predef_Op2, T);
7468 Add_One_Interp (N, Predef_Op, T);
7470 -- For operators with unary and binary interpretations, if
7471 -- context is not a call, add both
7473 if Present (Homonym (Predef_Op)) then
7474 Add_One_Interp (N, Homonym (Predef_Op), T);
7478 -- The node is a reference to a predefined operator, and
7479 -- an implicit reference to the type of its operands.
7481 if Present (Op_Type) then
7482 Generate_Operator_Reference (N, Op_Type);
7484 Generate_Operator_Reference (N, T);
7486 end Add_Implicit_Operator;
7488 -- Start of processing for Has_Implicit_Operator
7491 if Ekind (P) = E_Package and then not In_Open_Scopes (P) then
7492 Priv_Id := First_Private_Entity (P);
7495 Id := First_Entity (P);
7499 -- Boolean operators: an implicit declaration exists if the scope
7500 -- contains a declaration for a derived Boolean type, or for an
7501 -- array of Boolean type.
7503 when Name_Op_And | Name_Op_Not | Name_Op_Or | Name_Op_Xor =>
7504 while Id /= Priv_Id loop
7505 if Valid_Boolean_Arg (Id) and then Is_Base_Type (Id) then
7506 Add_Implicit_Operator (Id);
7513 -- Equality: look for any non-limited type (result is Boolean)
7515 when Name_Op_Eq | Name_Op_Ne =>
7516 while Id /= Priv_Id loop
7518 and then not Is_Limited_Type (Id)
7519 and then Is_Base_Type (Id)
7521 Add_Implicit_Operator (Standard_Boolean, Id);
7528 -- Comparison operators: scalar type, or array of scalar
7530 when Name_Op_Lt | Name_Op_Le | Name_Op_Gt | Name_Op_Ge =>
7531 while Id /= Priv_Id loop
7532 if (Is_Scalar_Type (Id)
7533 or else (Is_Array_Type (Id)
7534 and then Is_Scalar_Type (Component_Type (Id))))
7535 and then Is_Base_Type (Id)
7537 Add_Implicit_Operator (Standard_Boolean, Id);
7544 -- Arithmetic operators: any numeric type
7554 while Id /= Priv_Id loop
7555 if Is_Numeric_Type (Id) and then Is_Base_Type (Id) then
7556 Add_Implicit_Operator (Id);
7563 -- Concatenation: any one-dimensional array type
7565 when Name_Op_Concat =>
7566 while Id /= Priv_Id loop
7567 if Is_Array_Type (Id)
7568 and then Number_Dimensions (Id) = 1
7569 and then Is_Base_Type (Id)
7571 Add_Implicit_Operator (Id);
7578 -- What is the others condition here? Should we be using a
7579 -- subtype of Name_Id that would restrict to operators ???
7581 when others => null;
7584 -- If we fall through, then we do not have an implicit operator
7588 end Has_Implicit_Operator;
7590 -----------------------------------
7591 -- Has_Loop_In_Inner_Open_Scopes --
7592 -----------------------------------
7594 function Has_Loop_In_Inner_Open_Scopes (S : Entity_Id) return Boolean is
7596 -- Several scope stacks are maintained by Scope_Stack. The base of the
7597 -- currently active scope stack is denoted by the Is_Active_Stack_Base
7598 -- flag in the scope stack entry. Note that the scope stacks used to
7599 -- simply be delimited implicitly by the presence of Standard_Standard
7600 -- at their base, but there now are cases where this is not sufficient
7601 -- because Standard_Standard actually may appear in the middle of the
7602 -- active set of scopes.
7604 for J in reverse 0 .. Scope_Stack.Last loop
7606 -- S was reached without seing a loop scope first
7608 if Scope_Stack.Table (J).Entity = S then
7611 -- S was not yet reached, so it contains at least one inner loop
7613 elsif Ekind (Scope_Stack.Table (J).Entity) = E_Loop then
7617 -- Check Is_Active_Stack_Base to tell us when to stop, as there are
7618 -- cases where Standard_Standard appears in the middle of the active
7619 -- set of scopes. This affects the declaration and overriding of
7620 -- private inherited operations in instantiations of generic child
7623 pragma Assert (not Scope_Stack.Table (J).Is_Active_Stack_Base);
7626 raise Program_Error; -- unreachable
7627 end Has_Loop_In_Inner_Open_Scopes;
7629 --------------------
7630 -- In_Open_Scopes --
7631 --------------------
7633 function In_Open_Scopes (S : Entity_Id) return Boolean is
7635 -- Several scope stacks are maintained by Scope_Stack. The base of the
7636 -- currently active scope stack is denoted by the Is_Active_Stack_Base
7637 -- flag in the scope stack entry. Note that the scope stacks used to
7638 -- simply be delimited implicitly by the presence of Standard_Standard
7639 -- at their base, but there now are cases where this is not sufficient
7640 -- because Standard_Standard actually may appear in the middle of the
7641 -- active set of scopes.
7643 for J in reverse 0 .. Scope_Stack.Last loop
7644 if Scope_Stack.Table (J).Entity = S then
7648 -- Check Is_Active_Stack_Base to tell us when to stop, as there are
7649 -- cases where Standard_Standard appears in the middle of the active
7650 -- set of scopes. This affects the declaration and overriding of
7651 -- private inherited operations in instantiations of generic child
7654 exit when Scope_Stack.Table (J).Is_Active_Stack_Base;
7660 -----------------------------
7661 -- Inherit_Renamed_Profile --
7662 -----------------------------
7664 procedure Inherit_Renamed_Profile (New_S : Entity_Id; Old_S : Entity_Id) is
7671 if Ekind (Old_S) = E_Operator then
7672 New_F := First_Formal (New_S);
7674 while Present (New_F) loop
7675 Set_Etype (New_F, Base_Type (Etype (New_F)));
7676 Next_Formal (New_F);
7679 Set_Etype (New_S, Base_Type (Etype (New_S)));
7682 New_F := First_Formal (New_S);
7683 Old_F := First_Formal (Old_S);
7685 while Present (New_F) loop
7686 New_T := Etype (New_F);
7687 Old_T := Etype (Old_F);
7689 -- If the new type is a renaming of the old one, as is the
7690 -- case for actuals in instances, retain its name, to simplify
7691 -- later disambiguation.
7693 if Nkind (Parent (New_T)) = N_Subtype_Declaration
7694 and then Is_Entity_Name (Subtype_Indication (Parent (New_T)))
7695 and then Entity (Subtype_Indication (Parent (New_T))) = Old_T
7699 Set_Etype (New_F, Old_T);
7702 Next_Formal (New_F);
7703 Next_Formal (Old_F);
7706 if Ekind_In (Old_S, E_Function, E_Enumeration_Literal) then
7707 Set_Etype (New_S, Etype (Old_S));
7710 end Inherit_Renamed_Profile;
7716 procedure Initialize is
7721 -------------------------
7722 -- Install_Use_Clauses --
7723 -------------------------
7725 procedure Install_Use_Clauses
7727 Force_Installation : Boolean := False)
7735 while Present (U) loop
7737 -- Case of USE package
7739 if Nkind (U) = N_Use_Package_Clause then
7740 P := First (Names (U));
7741 while Present (P) loop
7744 if Ekind (Id) = E_Package then
7746 Note_Redundant_Use (P);
7748 elsif Present (Renamed_Object (Id))
7749 and then In_Use (Renamed_Object (Id))
7751 Note_Redundant_Use (P);
7753 elsif Force_Installation or else Applicable_Use (P) then
7754 Use_One_Package (Id, U);
7765 P := First (Subtype_Marks (U));
7766 while Present (P) loop
7767 if not Is_Entity_Name (P)
7768 or else No (Entity (P))
7772 elsif Entity (P) /= Any_Type then
7780 Next_Use_Clause (U);
7782 end Install_Use_Clauses;
7784 -------------------------------------
7785 -- Is_Appropriate_For_Entry_Prefix --
7786 -------------------------------------
7788 function Is_Appropriate_For_Entry_Prefix (T : Entity_Id) return Boolean is
7789 P_Type : Entity_Id := T;
7792 if Is_Access_Type (P_Type) then
7793 P_Type := Designated_Type (P_Type);
7796 return Is_Task_Type (P_Type) or else Is_Protected_Type (P_Type);
7797 end Is_Appropriate_For_Entry_Prefix;
7799 -------------------------------
7800 -- Is_Appropriate_For_Record --
7801 -------------------------------
7803 function Is_Appropriate_For_Record (T : Entity_Id) return Boolean is
7805 function Has_Components (T1 : Entity_Id) return Boolean;
7806 -- Determine if given type has components (i.e. is either a record
7807 -- type or a type that has discriminants).
7809 --------------------
7810 -- Has_Components --
7811 --------------------
7813 function Has_Components (T1 : Entity_Id) return Boolean is
7815 return Is_Record_Type (T1)
7816 or else (Is_Private_Type (T1) and then Has_Discriminants (T1))
7817 or else (Is_Task_Type (T1) and then Has_Discriminants (T1))
7818 or else (Is_Incomplete_Type (T1)
7819 and then From_Limited_With (T1)
7820 and then Present (Non_Limited_View (T1))
7821 and then Is_Record_Type
7822 (Get_Full_View (Non_Limited_View (T1))));
7825 -- Start of processing for Is_Appropriate_For_Record
7830 and then (Has_Components (T)
7831 or else (Is_Access_Type (T)
7832 and then Has_Components (Designated_Type (T))));
7833 end Is_Appropriate_For_Record;
7835 ------------------------
7836 -- Note_Redundant_Use --
7837 ------------------------
7839 procedure Note_Redundant_Use (Clause : Node_Id) is
7840 Pack_Name : constant Entity_Id := Entity (Clause);
7841 Cur_Use : constant Node_Id := Current_Use_Clause (Pack_Name);
7842 Decl : constant Node_Id := Parent (Clause);
7844 Prev_Use : Node_Id := Empty;
7845 Redundant : Node_Id := Empty;
7846 -- The Use_Clause which is actually redundant. In the simplest case it
7847 -- is Pack itself, but when we compile a body we install its context
7848 -- before that of its spec, in which case it is the use_clause in the
7849 -- spec that will appear to be redundant, and we want the warning to be
7850 -- placed on the body. Similar complications appear when the redundancy
7851 -- is between a child unit and one of its ancestors.
7854 Set_Redundant_Use (Clause, True);
7856 if not Comes_From_Source (Clause)
7858 or else not Warn_On_Redundant_Constructs
7863 if not Is_Compilation_Unit (Current_Scope) then
7865 -- If the use_clause is in an inner scope, it is made redundant by
7866 -- some clause in the current context, with one exception: If we're
7867 -- compiling a nested package body, and the use_clause comes from the
7868 -- corresponding spec, the clause is not necessarily fully redundant,
7869 -- so we should not warn. If a warning was warranted, it would have
7870 -- been given when the spec was processed.
7872 if Nkind (Parent (Decl)) = N_Package_Specification then
7874 Package_Spec_Entity : constant Entity_Id :=
7875 Defining_Unit_Name (Parent (Decl));
7877 if In_Package_Body (Package_Spec_Entity) then
7883 Redundant := Clause;
7884 Prev_Use := Cur_Use;
7886 elsif Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Body then
7888 Cur_Unit : constant Unit_Number_Type := Get_Source_Unit (Cur_Use);
7889 New_Unit : constant Unit_Number_Type := Get_Source_Unit (Clause);
7893 if Cur_Unit = New_Unit then
7895 -- Redundant clause in same body
7897 Redundant := Clause;
7898 Prev_Use := Cur_Use;
7900 elsif Cur_Unit = Current_Sem_Unit then
7902 -- If the new clause is not in the current unit it has been
7903 -- analyzed first, and it makes the other one redundant.
7904 -- However, if the new clause appears in a subunit, Cur_Unit
7905 -- is still the parent, and in that case the redundant one
7906 -- is the one appearing in the subunit.
7908 if Nkind (Unit (Cunit (New_Unit))) = N_Subunit then
7909 Redundant := Clause;
7910 Prev_Use := Cur_Use;
7912 -- Most common case: redundant clause in body,
7913 -- original clause in spec. Current scope is spec entity.
7918 Unit (Library_Unit (Cunit (Current_Sem_Unit))))
7920 Redundant := Cur_Use;
7924 -- The new clause may appear in an unrelated unit, when
7925 -- the parents of a generic are being installed prior to
7926 -- instantiation. In this case there must be no warning.
7927 -- We detect this case by checking whether the current top
7928 -- of the stack is related to the current compilation.
7930 Scop := Current_Scope;
7931 while Present (Scop) and then Scop /= Standard_Standard loop
7932 if Is_Compilation_Unit (Scop)
7933 and then not Is_Child_Unit (Scop)
7937 elsif Scop = Cunit_Entity (Current_Sem_Unit) then
7941 Scop := Scope (Scop);
7944 Redundant := Cur_Use;
7948 elsif New_Unit = Current_Sem_Unit then
7949 Redundant := Clause;
7950 Prev_Use := Cur_Use;
7953 -- Neither is the current unit, so they appear in parent or
7954 -- sibling units. Warning will be emitted elsewhere.
7960 elsif Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Declaration
7961 and then Present (Parent_Spec (Unit (Cunit (Current_Sem_Unit))))
7963 -- Use_clause is in child unit of current unit, and the child unit
7964 -- appears in the context of the body of the parent, so it has been
7965 -- installed first, even though it is the redundant one. Depending on
7966 -- their placement in the context, the visible or the private parts
7967 -- of the two units, either might appear as redundant, but the
7968 -- message has to be on the current unit.
7970 if Get_Source_Unit (Cur_Use) = Current_Sem_Unit then
7971 Redundant := Cur_Use;
7974 Redundant := Clause;
7975 Prev_Use := Cur_Use;
7978 -- If the new use clause appears in the private part of a parent unit
7979 -- it may appear to be redundant w.r.t. a use clause in a child unit,
7980 -- but the previous use clause was needed in the visible part of the
7981 -- child, and no warning should be emitted.
7983 if Nkind (Parent (Decl)) = N_Package_Specification
7985 List_Containing (Decl) = Private_Declarations (Parent (Decl))
7988 Par : constant Entity_Id := Defining_Entity (Parent (Decl));
7989 Spec : constant Node_Id :=
7990 Specification (Unit (Cunit (Current_Sem_Unit)));
7993 if Is_Compilation_Unit (Par)
7994 and then Par /= Cunit_Entity (Current_Sem_Unit)
7995 and then Parent (Cur_Use) = Spec
7997 List_Containing (Cur_Use) = Visible_Declarations (Spec)
8004 -- Finally, if the current use clause is in the context then
8005 -- the clause is redundant when it is nested within the unit.
8007 elsif Nkind (Parent (Cur_Use)) = N_Compilation_Unit
8008 and then Nkind (Parent (Parent (Clause))) /= N_Compilation_Unit
8009 and then Get_Source_Unit (Cur_Use) = Get_Source_Unit (Clause)
8011 Redundant := Clause;
8012 Prev_Use := Cur_Use;
8018 if Present (Redundant) then
8019 Error_Msg_Sloc := Sloc (Prev_Use);
8020 Error_Msg_NE -- CODEFIX
8021 ("& is already use-visible through previous use clause #??",
8022 Redundant, Pack_Name);
8024 end Note_Redundant_Use;
8030 procedure Pop_Scope is
8031 SST : Scope_Stack_Entry renames Scope_Stack.Table (Scope_Stack.Last);
8032 S : constant Entity_Id := SST.Entity;
8035 if Debug_Flag_E then
8039 -- Set Default_Storage_Pool field of the library unit if necessary
8041 if Ekind_In (S, E_Package, E_Generic_Package)
8043 Nkind (Parent (Unit_Declaration_Node (S))) = N_Compilation_Unit
8046 Aux : constant Node_Id :=
8047 Aux_Decls_Node (Parent (Unit_Declaration_Node (S)));
8049 if No (Default_Storage_Pool (Aux)) then
8050 Set_Default_Storage_Pool (Aux, Default_Pool);
8055 Scope_Suppress := SST.Save_Scope_Suppress;
8056 Local_Suppress_Stack_Top := SST.Save_Local_Suppress_Stack_Top;
8057 Check_Policy_List := SST.Save_Check_Policy_List;
8058 Default_Pool := SST.Save_Default_Storage_Pool;
8059 No_Tagged_Streams := SST.Save_No_Tagged_Streams;
8060 SPARK_Mode := SST.Save_SPARK_Mode;
8061 SPARK_Mode_Pragma := SST.Save_SPARK_Mode_Pragma;
8062 Default_SSO := SST.Save_Default_SSO;
8063 Uneval_Old := SST.Save_Uneval_Old;
8065 if Debug_Flag_W then
8066 Write_Str ("<-- exiting scope: ");
8067 Write_Name (Chars (Current_Scope));
8068 Write_Str (", Depth=");
8069 Write_Int (Int (Scope_Stack.Last));
8073 End_Use_Clauses (SST.First_Use_Clause);
8075 -- If the actions to be wrapped are still there they will get lost
8076 -- causing incomplete code to be generated. It is better to abort in
8077 -- this case (and we do the abort even with assertions off since the
8078 -- penalty is incorrect code generation).
8080 if SST.Actions_To_Be_Wrapped /= Scope_Actions'(others => No_List) then
8081 raise Program_Error;
8084 -- Free last subprogram name if allocated, and pop scope
8086 Free (SST.Last_Subprogram_Name);
8087 Scope_Stack.Decrement_Last;
8094 procedure Push_Scope (S : Entity_Id) is
8095 E : constant Entity_Id := Scope (S);
8098 if Ekind (S) = E_Void then
8101 -- Set scope depth if not a non-concurrent type, and we have not yet set
8102 -- the scope depth. This means that we have the first occurrence of the
8103 -- scope, and this is where the depth is set.
8105 elsif (not Is_Type (S) or else Is_Concurrent_Type (S))
8106 and then not Scope_Depth_Set (S)
8108 if S = Standard_Standard then
8109 Set_Scope_Depth_Value (S, Uint_0);
8111 elsif Is_Child_Unit (S) then
8112 Set_Scope_Depth_Value (S, Uint_1);
8114 elsif not Is_Record_Type (Current_Scope) then
8115 if Ekind (S) = E_Loop then
8116 Set_Scope_Depth_Value (S, Scope_Depth (Current_Scope));
8118 Set_Scope_Depth_Value (S, Scope_Depth (Current_Scope) + 1);
8123 Scope_Stack.Increment_Last;
8126 SST : Scope_Stack_Entry renames Scope_Stack.Table (Scope_Stack.Last);
8130 SST.Save_Scope_Suppress := Scope_Suppress;
8131 SST.Save_Local_Suppress_Stack_Top := Local_Suppress_Stack_Top;
8132 SST.Save_Check_Policy_List := Check_Policy_List;
8133 SST.Save_Default_Storage_Pool := Default_Pool;
8134 SST.Save_No_Tagged_Streams := No_Tagged_Streams;
8135 SST.Save_SPARK_Mode := SPARK_Mode;
8136 SST.Save_SPARK_Mode_Pragma := SPARK_Mode_Pragma;
8137 SST.Save_Default_SSO := Default_SSO;
8138 SST.Save_Uneval_Old := Uneval_Old;
8140 if Scope_Stack.Last > Scope_Stack.First then
8141 SST.Component_Alignment_Default := Scope_Stack.Table
8142 (Scope_Stack.Last - 1).
8143 Component_Alignment_Default;
8146 SST.Last_Subprogram_Name := null;
8147 SST.Is_Transient := False;
8148 SST.Node_To_Be_Wrapped := Empty;
8149 SST.Pending_Freeze_Actions := No_List;
8150 SST.Actions_To_Be_Wrapped := (others => No_List);
8151 SST.First_Use_Clause := Empty;
8152 SST.Is_Active_Stack_Base := False;
8153 SST.Previous_Visibility := False;
8154 SST.Locked_Shared_Objects := No_Elist;
8157 if Debug_Flag_W then
8158 Write_Str ("--> new scope: ");
8159 Write_Name (Chars (Current_Scope));
8160 Write_Str (", Id=");
8161 Write_Int (Int (Current_Scope));
8162 Write_Str (", Depth=");
8163 Write_Int (Int (Scope_Stack.Last));
8167 -- Deal with copying flags from the previous scope to this one. This is
8168 -- not necessary if either scope is standard, or if the new scope is a
8171 if S /= Standard_Standard
8172 and then Scope (S) /= Standard_Standard
8173 and then not Is_Child_Unit (S)
8175 if Nkind (E) not in N_Entity then
8179 -- Copy categorization flags from Scope (S) to S, this is not done
8180 -- when Scope (S) is Standard_Standard since propagation is from
8181 -- library unit entity inwards. Copy other relevant attributes as
8182 -- well (Discard_Names in particular).
8184 -- We only propagate inwards for library level entities,
8185 -- inner level subprograms do not inherit the categorization.
8187 if Is_Library_Level_Entity (S) then
8188 Set_Is_Preelaborated (S, Is_Preelaborated (E));
8189 Set_Is_Shared_Passive (S, Is_Shared_Passive (E));
8190 Set_Discard_Names (S, Discard_Names (E));
8191 Set_Suppress_Value_Tracking_On_Call
8192 (S, Suppress_Value_Tracking_On_Call (E));
8193 Set_Categorization_From_Scope (E => S, Scop => E);
8197 if Is_Child_Unit (S)
8198 and then Present (E)
8199 and then Ekind_In (E, E_Package, E_Generic_Package)
8201 Nkind (Parent (Unit_Declaration_Node (E))) = N_Compilation_Unit
8204 Aux : constant Node_Id :=
8205 Aux_Decls_Node (Parent (Unit_Declaration_Node (E)));
8207 if Present (Default_Storage_Pool (Aux)) then
8208 Default_Pool := Default_Storage_Pool (Aux);
8214 ---------------------
8215 -- Premature_Usage --
8216 ---------------------
8218 procedure Premature_Usage (N : Node_Id) is
8219 Kind : constant Node_Kind := Nkind (Parent (Entity (N)));
8220 E : Entity_Id := Entity (N);
8223 -- Within an instance, the analysis of the actual for a formal object
8224 -- does not see the name of the object itself. This is significant only
8225 -- if the object is an aggregate, where its analysis does not do any
8226 -- name resolution on component associations. (see 4717-008). In such a
8227 -- case, look for the visible homonym on the chain.
8229 if In_Instance and then Present (Homonym (E)) then
8231 while Present (E) and then not In_Open_Scopes (Scope (E)) loop
8237 Set_Etype (N, Etype (E));
8242 if Kind = N_Component_Declaration then
8244 ("component&! cannot be used before end of record declaration", N);
8246 elsif Kind = N_Parameter_Specification then
8248 ("formal parameter&! cannot be used before end of specification",
8251 elsif Kind = N_Discriminant_Specification then
8253 ("discriminant&! cannot be used before end of discriminant part",
8256 elsif Kind = N_Procedure_Specification
8257 or else Kind = N_Function_Specification
8260 ("subprogram&! cannot be used before end of its declaration",
8263 elsif Kind = N_Full_Type_Declaration then
8265 ("type& cannot be used before end of its declaration!", N);
8269 ("object& cannot be used before end of its declaration!", N);
8271 end Premature_Usage;
8273 ------------------------
8274 -- Present_System_Aux --
8275 ------------------------
8277 function Present_System_Aux (N : Node_Id := Empty) return Boolean is
8279 Aux_Name : Unit_Name_Type;
8280 Unum : Unit_Number_Type;
8285 function Find_System (C_Unit : Node_Id) return Entity_Id;
8286 -- Scan context clause of compilation unit to find with_clause
8293 function Find_System (C_Unit : Node_Id) return Entity_Id is
8294 With_Clause : Node_Id;
8297 With_Clause := First (Context_Items (C_Unit));
8298 while Present (With_Clause) loop
8299 if (Nkind (With_Clause) = N_With_Clause
8300 and then Chars (Name (With_Clause)) = Name_System)
8301 and then Comes_From_Source (With_Clause)
8312 -- Start of processing for Present_System_Aux
8315 -- The child unit may have been loaded and analyzed already
8317 if Present (System_Aux_Id) then
8320 -- If no previous pragma for System.Aux, nothing to load
8322 elsif No (System_Extend_Unit) then
8325 -- Use the unit name given in the pragma to retrieve the unit.
8326 -- Verify that System itself appears in the context clause of the
8327 -- current compilation. If System is not present, an error will
8328 -- have been reported already.
8331 With_Sys := Find_System (Cunit (Current_Sem_Unit));
8333 The_Unit := Unit (Cunit (Current_Sem_Unit));
8337 (Nkind (The_Unit) = N_Package_Body
8338 or else (Nkind (The_Unit) = N_Subprogram_Body
8339 and then not Acts_As_Spec (Cunit (Current_Sem_Unit))))
8341 With_Sys := Find_System (Library_Unit (Cunit (Current_Sem_Unit)));
8344 if No (With_Sys) and then Present (N) then
8346 -- If we are compiling a subunit, we need to examine its
8347 -- context as well (Current_Sem_Unit is the parent unit);
8349 The_Unit := Parent (N);
8350 while Nkind (The_Unit) /= N_Compilation_Unit loop
8351 The_Unit := Parent (The_Unit);
8354 if Nkind (Unit (The_Unit)) = N_Subunit then
8355 With_Sys := Find_System (The_Unit);
8359 if No (With_Sys) then
8363 Loc := Sloc (With_Sys);
8364 Get_Name_String (Chars (Expression (System_Extend_Unit)));
8365 Name_Buffer (8 .. Name_Len + 7) := Name_Buffer (1 .. Name_Len);
8366 Name_Buffer (1 .. 7) := "system.";
8367 Name_Buffer (Name_Len + 8) := '%';
8368 Name_Buffer (Name_Len + 9) := 's';
8369 Name_Len := Name_Len + 9;
8370 Aux_Name := Name_Find;
8374 (Load_Name => Aux_Name,
8377 Error_Node => With_Sys);
8379 if Unum /= No_Unit then
8380 Semantics (Cunit (Unum));
8382 Defining_Entity (Specification (Unit (Cunit (Unum))));
8385 Make_With_Clause (Loc,
8387 Make_Expanded_Name (Loc,
8388 Chars => Chars (System_Aux_Id),
8389 Prefix => New_Occurrence_Of (Scope (System_Aux_Id), Loc),
8390 Selector_Name => New_Occurrence_Of (System_Aux_Id, Loc)));
8392 Set_Entity (Name (Withn), System_Aux_Id);
8394 Set_Library_Unit (Withn, Cunit (Unum));
8395 Set_Corresponding_Spec (Withn, System_Aux_Id);
8396 Set_First_Name (Withn, True);
8397 Set_Implicit_With (Withn, True);
8399 Insert_After (With_Sys, Withn);
8400 Mark_Rewrite_Insertion (Withn);
8401 Set_Context_Installed (Withn);
8405 -- Here if unit load failed
8408 Error_Msg_Name_1 := Name_System;
8409 Error_Msg_Name_2 := Chars (Expression (System_Extend_Unit));
8411 ("extension package `%.%` does not exist",
8412 Opt.System_Extend_Unit);
8416 end Present_System_Aux;
8418 -------------------------
8419 -- Restore_Scope_Stack --
8420 -------------------------
8422 procedure Restore_Scope_Stack
8424 Handle_Use : Boolean := True)
8426 SS_Last : constant Int := Scope_Stack.Last;
8430 -- Restore visibility of previous scope stack, if any, using the list
8431 -- we saved (we use Remove, since this list will not be used again).
8434 Elmt := Last_Elmt (List);
8435 exit when Elmt = No_Elmt;
8436 Set_Is_Immediately_Visible (Node (Elmt));
8437 Remove_Last_Elmt (List);
8440 -- Restore use clauses
8442 if SS_Last >= Scope_Stack.First
8443 and then Scope_Stack.Table (SS_Last).Entity /= Standard_Standard
8446 Install_Use_Clauses (Scope_Stack.Table (SS_Last).First_Use_Clause);
8448 end Restore_Scope_Stack;
8450 ----------------------
8451 -- Save_Scope_Stack --
8452 ----------------------
8454 -- Save_Scope_Stack/Restore_Scope_Stack were originally designed to avoid
8455 -- consuming any memory. That is, Save_Scope_Stack took care of removing
8456 -- from immediate visibility entities and Restore_Scope_Stack took care
8457 -- of restoring their visibility analyzing the context of each entity. The
8458 -- problem of such approach is that it was fragile and caused unexpected
8459 -- visibility problems, and indeed one test was found where there was a
8462 -- Furthermore, the following experiment was carried out:
8464 -- - Save_Scope_Stack was modified to store in an Elist1 all those
8465 -- entities whose attribute Is_Immediately_Visible is modified
8466 -- from True to False.
8468 -- - Restore_Scope_Stack was modified to store in another Elist2
8469 -- all the entities whose attribute Is_Immediately_Visible is
8470 -- modified from False to True.
8472 -- - Extra code was added to verify that all the elements of Elist1
8473 -- are found in Elist2
8475 -- This test shows that there may be more occurrences of this problem which
8476 -- have not yet been detected. As a result, we replaced that approach by
8477 -- the current one in which Save_Scope_Stack returns the list of entities
8478 -- whose visibility is changed, and that list is passed to Restore_Scope_
8479 -- Stack to undo that change. This approach is simpler and safer, although
8480 -- it consumes more memory.
8482 function Save_Scope_Stack (Handle_Use : Boolean := True) return Elist_Id is
8483 Result : constant Elist_Id := New_Elmt_List;
8486 SS_Last : constant Int := Scope_Stack.Last;
8488 procedure Remove_From_Visibility (E : Entity_Id);
8489 -- If E is immediately visible then append it to the result and remove
8490 -- it temporarily from visibility.
8492 ----------------------------
8493 -- Remove_From_Visibility --
8494 ----------------------------
8496 procedure Remove_From_Visibility (E : Entity_Id) is
8498 if Is_Immediately_Visible (E) then
8499 Append_Elmt (E, Result);
8500 Set_Is_Immediately_Visible (E, False);
8502 end Remove_From_Visibility;
8504 -- Start of processing for Save_Scope_Stack
8507 if SS_Last >= Scope_Stack.First
8508 and then Scope_Stack.Table (SS_Last).Entity /= Standard_Standard
8511 End_Use_Clauses (Scope_Stack.Table (SS_Last).First_Use_Clause);
8514 -- If the call is from within a compilation unit, as when called from
8515 -- Rtsfind, make current entries in scope stack invisible while we
8516 -- analyze the new unit.
8518 for J in reverse 0 .. SS_Last loop
8519 exit when Scope_Stack.Table (J).Entity = Standard_Standard
8520 or else No (Scope_Stack.Table (J).Entity);
8522 S := Scope_Stack.Table (J).Entity;
8524 Remove_From_Visibility (S);
8526 E := First_Entity (S);
8527 while Present (E) loop
8528 Remove_From_Visibility (E);
8536 end Save_Scope_Stack;
8542 procedure Set_Use (L : List_Id) is
8544 Pack_Name : Node_Id;
8551 while Present (Decl) loop
8552 if Nkind (Decl) = N_Use_Package_Clause then
8553 Chain_Use_Clause (Decl);
8555 Pack_Name := First (Names (Decl));
8556 while Present (Pack_Name) loop
8557 Pack := Entity (Pack_Name);
8559 if Ekind (Pack) = E_Package
8560 and then Applicable_Use (Pack_Name)
8562 Use_One_Package (Pack, Decl);
8568 elsif Nkind (Decl) = N_Use_Type_Clause then
8569 Chain_Use_Clause (Decl);
8571 Id := First (Subtype_Marks (Decl));
8572 while Present (Id) loop
8573 if Entity (Id) /= Any_Type then
8586 ---------------------
8587 -- Use_One_Package --
8588 ---------------------
8590 procedure Use_One_Package (P : Entity_Id; N : Node_Id) is
8593 Current_Instance : Entity_Id := Empty;
8595 Private_With_OK : Boolean := False;
8598 if Ekind (P) /= E_Package then
8603 Set_Current_Use_Clause (P, N);
8605 -- Ada 2005 (AI-50217): Check restriction
8607 if From_Limited_With (P) then
8608 Error_Msg_N ("limited withed package cannot appear in use clause", N);
8611 -- Find enclosing instance, if any
8614 Current_Instance := Current_Scope;
8615 while not Is_Generic_Instance (Current_Instance) loop
8616 Current_Instance := Scope (Current_Instance);
8619 if No (Hidden_By_Use_Clause (N)) then
8620 Set_Hidden_By_Use_Clause (N, New_Elmt_List);
8624 -- If unit is a package renaming, indicate that the renamed
8625 -- package is also in use (the flags on both entities must
8626 -- remain consistent, and a subsequent use of either of them
8627 -- should be recognized as redundant).
8629 if Present (Renamed_Object (P)) then
8630 Set_In_Use (Renamed_Object (P));
8631 Set_Current_Use_Clause (Renamed_Object (P), N);
8632 Real_P := Renamed_Object (P);
8637 -- Ada 2005 (AI-262): Check the use_clause of a private withed package
8638 -- found in the private part of a package specification
8640 if In_Private_Part (Current_Scope)
8641 and then Has_Private_With (P)
8642 and then Is_Child_Unit (Current_Scope)
8643 and then Is_Child_Unit (P)
8644 and then Is_Ancestor_Package (Scope (Current_Scope), P)
8646 Private_With_OK := True;
8649 -- Loop through entities in one package making them potentially
8652 Id := First_Entity (P);
8654 and then (Id /= First_Private_Entity (P)
8655 or else Private_With_OK) -- Ada 2005 (AI-262)
8657 Prev := Current_Entity (Id);
8658 while Present (Prev) loop
8659 if Is_Immediately_Visible (Prev)
8660 and then (not Is_Overloadable (Prev)
8661 or else not Is_Overloadable (Id)
8662 or else (Type_Conformant (Id, Prev)))
8664 if No (Current_Instance) then
8666 -- Potentially use-visible entity remains hidden
8668 goto Next_Usable_Entity;
8670 -- A use clause within an instance hides outer global entities,
8671 -- which are not used to resolve local entities in the
8672 -- instance. Note that the predefined entities in Standard
8673 -- could not have been hidden in the generic by a use clause,
8674 -- and therefore remain visible. Other compilation units whose
8675 -- entities appear in Standard must be hidden in an instance.
8677 -- To determine whether an entity is external to the instance
8678 -- we compare the scope depth of its scope with that of the
8679 -- current instance. However, a generic actual of a subprogram
8680 -- instance is declared in the wrapper package but will not be
8681 -- hidden by a use-visible entity. similarly, an entity that is
8682 -- declared in an enclosing instance will not be hidden by an
8683 -- an entity declared in a generic actual, which can only have
8684 -- been use-visible in the generic and will not have hidden the
8685 -- entity in the generic parent.
8687 -- If Id is called Standard, the predefined package with the
8688 -- same name is in the homonym chain. It has to be ignored
8689 -- because it has no defined scope (being the only entity in
8690 -- the system with this mandated behavior).
8692 elsif not Is_Hidden (Id)
8693 and then Present (Scope (Prev))
8694 and then not Is_Wrapper_Package (Scope (Prev))
8695 and then Scope_Depth (Scope (Prev)) <
8696 Scope_Depth (Current_Instance)
8697 and then (Scope (Prev) /= Standard_Standard
8698 or else Sloc (Prev) > Standard_Location)
8700 if In_Open_Scopes (Scope (Prev))
8701 and then Is_Generic_Instance (Scope (Prev))
8702 and then Present (Associated_Formal_Package (P))
8707 Set_Is_Potentially_Use_Visible (Id);
8708 Set_Is_Immediately_Visible (Prev, False);
8709 Append_Elmt (Prev, Hidden_By_Use_Clause (N));
8713 -- A user-defined operator is not use-visible if the predefined
8714 -- operator for the type is immediately visible, which is the case
8715 -- if the type of the operand is in an open scope. This does not
8716 -- apply to user-defined operators that have operands of different
8717 -- types, because the predefined mixed mode operations (multiply
8718 -- and divide) apply to universal types and do not hide anything.
8720 elsif Ekind (Prev) = E_Operator
8721 and then Operator_Matches_Spec (Prev, Id)
8722 and then In_Open_Scopes
8723 (Scope (Base_Type (Etype (First_Formal (Id)))))
8724 and then (No (Next_Formal (First_Formal (Id)))
8725 or else Etype (First_Formal (Id)) =
8726 Etype (Next_Formal (First_Formal (Id)))
8727 or else Chars (Prev) = Name_Op_Expon)
8729 goto Next_Usable_Entity;
8731 -- In an instance, two homonyms may become use_visible through the
8732 -- actuals of distinct formal packages. In the generic, only the
8733 -- current one would have been visible, so make the other one
8736 elsif Present (Current_Instance)
8737 and then Is_Potentially_Use_Visible (Prev)
8738 and then not Is_Overloadable (Prev)
8739 and then Scope (Id) /= Scope (Prev)
8740 and then Used_As_Generic_Actual (Scope (Prev))
8741 and then Used_As_Generic_Actual (Scope (Id))
8742 and then not In_Same_List (Current_Use_Clause (Scope (Prev)),
8743 Current_Use_Clause (Scope (Id)))
8745 Set_Is_Potentially_Use_Visible (Prev, False);
8746 Append_Elmt (Prev, Hidden_By_Use_Clause (N));
8749 Prev := Homonym (Prev);
8752 -- On exit, we know entity is not hidden, unless it is private
8754 if not Is_Hidden (Id)
8755 and then ((not Is_Child_Unit (Id)) or else Is_Visible_Lib_Unit (Id))
8757 Set_Is_Potentially_Use_Visible (Id);
8759 if Is_Private_Type (Id) and then Present (Full_View (Id)) then
8760 Set_Is_Potentially_Use_Visible (Full_View (Id));
8764 <<Next_Usable_Entity>>
8768 -- Child units are also made use-visible by a use clause, but they may
8769 -- appear after all visible declarations in the parent entity list.
8771 while Present (Id) loop
8772 if Is_Child_Unit (Id) and then Is_Visible_Lib_Unit (Id) then
8773 Set_Is_Potentially_Use_Visible (Id);
8779 if Chars (Real_P) = Name_System
8780 and then Scope (Real_P) = Standard_Standard
8781 and then Present_System_Aux (N)
8783 Use_One_Package (System_Aux_Id, N);
8786 end Use_One_Package;
8792 procedure Use_One_Type (Id : Node_Id; Installed : Boolean := False) is
8794 Is_Known_Used : Boolean;
8798 function Spec_Reloaded_For_Body return Boolean;
8799 -- Determine whether the compilation unit is a package body and the use
8800 -- type clause is in the spec of the same package. Even though the spec
8801 -- was analyzed first, its context is reloaded when analysing the body.
8803 procedure Use_Class_Wide_Operations (Typ : Entity_Id);
8804 -- AI05-150: if the use_type_clause carries the "all" qualifier,
8805 -- class-wide operations of ancestor types are use-visible if the
8806 -- ancestor type is visible.
8808 ----------------------------
8809 -- Spec_Reloaded_For_Body --
8810 ----------------------------
8812 function Spec_Reloaded_For_Body return Boolean is
8814 if Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Body then
8816 Spec : constant Node_Id :=
8817 Parent (List_Containing (Parent (Id)));
8820 -- Check whether type is declared in a package specification,
8821 -- and current unit is the corresponding package body. The
8822 -- use clauses themselves may be within a nested package.
8825 Nkind (Spec) = N_Package_Specification
8827 In_Same_Source_Unit (Corresponding_Body (Parent (Spec)),
8828 Cunit_Entity (Current_Sem_Unit));
8833 end Spec_Reloaded_For_Body;
8835 -------------------------------
8836 -- Use_Class_Wide_Operations --
8837 -------------------------------
8839 procedure Use_Class_Wide_Operations (Typ : Entity_Id) is
8843 function Is_Class_Wide_Operation_Of
8845 T : Entity_Id) return Boolean;
8846 -- Determine whether a subprogram has a class-wide parameter or
8847 -- result that is T'Class.
8849 ---------------------------------
8850 -- Is_Class_Wide_Operation_Of --
8851 ---------------------------------
8853 function Is_Class_Wide_Operation_Of
8855 T : Entity_Id) return Boolean
8860 Formal := First_Formal (Op);
8861 while Present (Formal) loop
8862 if Etype (Formal) = Class_Wide_Type (T) then
8865 Next_Formal (Formal);
8868 if Etype (Op) = Class_Wide_Type (T) then
8873 end Is_Class_Wide_Operation_Of;
8875 -- Start of processing for Use_Class_Wide_Operations
8878 Scop := Scope (Typ);
8879 if not Is_Hidden (Scop) then
8880 Ent := First_Entity (Scop);
8881 while Present (Ent) loop
8882 if Is_Overloadable (Ent)
8883 and then Is_Class_Wide_Operation_Of (Ent, Typ)
8884 and then not Is_Potentially_Use_Visible (Ent)
8886 Set_Is_Potentially_Use_Visible (Ent);
8887 Append_Elmt (Ent, Used_Operations (Parent (Id)));
8894 if Is_Derived_Type (Typ) then
8895 Use_Class_Wide_Operations (Etype (Base_Type (Typ)));
8897 end Use_Class_Wide_Operations;
8899 -- Start of processing for Use_One_Type
8902 -- It is the type determined by the subtype mark (8.4(8)) whose
8903 -- operations become potentially use-visible.
8905 T := Base_Type (Entity (Id));
8907 -- Either the type itself is used, the package where it is declared
8908 -- is in use or the entity is declared in the current package, thus
8913 or else In_Use (Scope (T))
8914 or else Scope (T) = Current_Scope;
8916 Set_Redundant_Use (Id,
8917 Is_Known_Used or else Is_Potentially_Use_Visible (T));
8919 if Ekind (T) = E_Incomplete_Type then
8920 Error_Msg_N ("premature usage of incomplete type", Id);
8922 elsif In_Open_Scopes (Scope (T)) then
8925 -- A limited view cannot appear in a use_type clause. However, an access
8926 -- type whose designated type is limited has the flag but is not itself
8927 -- a limited view unless we only have a limited view of its enclosing
8930 elsif From_Limited_With (T) and then From_Limited_With (Scope (T)) then
8932 ("incomplete type from limited view "
8933 & "cannot appear in use clause", Id);
8935 -- If the subtype mark designates a subtype in a different package,
8936 -- we have to check that the parent type is visible, otherwise the
8937 -- use type clause is a noop. Not clear how to do that???
8939 elsif not Redundant_Use (Id) then
8942 -- If T is tagged, primitive operators on class-wide operands
8943 -- are also available.
8945 if Is_Tagged_Type (T) then
8946 Set_In_Use (Class_Wide_Type (T));
8949 Set_Current_Use_Clause (T, Parent (Id));
8951 -- Iterate over primitive operations of the type. If an operation is
8952 -- already use_visible, it is the result of a previous use_clause,
8953 -- and already appears on the corresponding entity chain. If the
8954 -- clause is being reinstalled, operations are already use-visible.
8960 Op_List := Collect_Primitive_Operations (T);
8961 Elmt := First_Elmt (Op_List);
8962 while Present (Elmt) loop
8963 if (Nkind (Node (Elmt)) = N_Defining_Operator_Symbol
8964 or else Chars (Node (Elmt)) in Any_Operator_Name)
8965 and then not Is_Hidden (Node (Elmt))
8966 and then not Is_Potentially_Use_Visible (Node (Elmt))
8968 Set_Is_Potentially_Use_Visible (Node (Elmt));
8969 Append_Elmt (Node (Elmt), Used_Operations (Parent (Id)));
8971 elsif Ada_Version >= Ada_2012
8972 and then All_Present (Parent (Id))
8973 and then not Is_Hidden (Node (Elmt))
8974 and then not Is_Potentially_Use_Visible (Node (Elmt))
8976 Set_Is_Potentially_Use_Visible (Node (Elmt));
8977 Append_Elmt (Node (Elmt), Used_Operations (Parent (Id)));
8984 if Ada_Version >= Ada_2012
8985 and then All_Present (Parent (Id))
8986 and then Is_Tagged_Type (T)
8988 Use_Class_Wide_Operations (T);
8992 -- If warning on redundant constructs, check for unnecessary WITH
8994 if Warn_On_Redundant_Constructs
8995 and then Is_Known_Used
8997 -- with P; with P; use P;
8998 -- package P is package X is package body X is
8999 -- type T ... use P.T;
9001 -- The compilation unit is the body of X. GNAT first compiles the
9002 -- spec of X, then proceeds to the body. At that point P is marked
9003 -- as use visible. The analysis then reinstalls the spec along with
9004 -- its context. The use clause P.T is now recognized as redundant,
9005 -- but in the wrong context. Do not emit a warning in such cases.
9006 -- Do not emit a warning either if we are in an instance, there is
9007 -- no redundancy between an outer use_clause and one that appears
9008 -- within the generic.
9010 and then not Spec_Reloaded_For_Body
9011 and then not In_Instance
9013 -- The type already has a use clause
9017 -- Case where we know the current use clause for the type
9019 if Present (Current_Use_Clause (T)) then
9020 Use_Clause_Known : declare
9021 Clause1 : constant Node_Id := Parent (Id);
9022 Clause2 : constant Node_Id := Current_Use_Clause (T);
9029 function Entity_Of_Unit (U : Node_Id) return Entity_Id;
9030 -- Return the appropriate entity for determining which unit
9031 -- has a deeper scope: the defining entity for U, unless U
9032 -- is a package instance, in which case we retrieve the
9033 -- entity of the instance spec.
9035 --------------------
9036 -- Entity_Of_Unit --
9037 --------------------
9039 function Entity_Of_Unit (U : Node_Id) return Entity_Id is
9041 if Nkind (U) = N_Package_Instantiation
9042 and then Analyzed (U)
9044 return Defining_Entity (Instance_Spec (U));
9046 return Defining_Entity (U);
9050 -- Start of processing for Use_Clause_Known
9053 -- If both current use type clause and the use type clause
9054 -- for the type are at the compilation unit level, one of
9055 -- the units must be an ancestor of the other, and the
9056 -- warning belongs on the descendant.
9058 if Nkind (Parent (Clause1)) = N_Compilation_Unit
9060 Nkind (Parent (Clause2)) = N_Compilation_Unit
9062 -- If the unit is a subprogram body that acts as spec,
9063 -- the context clause is shared with the constructed
9064 -- subprogram spec. Clearly there is no redundancy.
9066 if Clause1 = Clause2 then
9070 Unit1 := Unit (Parent (Clause1));
9071 Unit2 := Unit (Parent (Clause2));
9073 -- If both clauses are on same unit, or one is the body
9074 -- of the other, or one of them is in a subunit, report
9075 -- redundancy on the later one.
9077 if Unit1 = Unit2 then
9078 Error_Msg_Sloc := Sloc (Current_Use_Clause (T));
9079 Error_Msg_NE -- CODEFIX
9080 ("& is already use-visible through previous "
9081 & "use_type_clause #??", Clause1, T);
9084 elsif Nkind (Unit1) = N_Subunit then
9085 Error_Msg_Sloc := Sloc (Current_Use_Clause (T));
9086 Error_Msg_NE -- CODEFIX
9087 ("& is already use-visible through previous "
9088 & "use_type_clause #??", Clause1, T);
9091 elsif Nkind_In (Unit2, N_Package_Body, N_Subprogram_Body)
9092 and then Nkind (Unit1) /= Nkind (Unit2)
9093 and then Nkind (Unit1) /= N_Subunit
9095 Error_Msg_Sloc := Sloc (Clause1);
9096 Error_Msg_NE -- CODEFIX
9097 ("& is already use-visible through previous "
9098 & "use_type_clause #??", Current_Use_Clause (T), T);
9102 -- There is a redundant use type clause in a child unit.
9103 -- Determine which of the units is more deeply nested.
9104 -- If a unit is a package instance, retrieve the entity
9105 -- and its scope from the instance spec.
9107 Ent1 := Entity_Of_Unit (Unit1);
9108 Ent2 := Entity_Of_Unit (Unit2);
9110 if Scope (Ent2) = Standard_Standard then
9111 Error_Msg_Sloc := Sloc (Current_Use_Clause (T));
9114 elsif Scope (Ent1) = Standard_Standard then
9115 Error_Msg_Sloc := Sloc (Id);
9118 -- If both units are child units, we determine which one
9119 -- is the descendant by the scope distance to the
9120 -- ultimate parent unit.
9130 and then Present (S2)
9131 and then S1 /= Standard_Standard
9132 and then S2 /= Standard_Standard
9138 if S1 = Standard_Standard then
9139 Error_Msg_Sloc := Sloc (Id);
9142 Error_Msg_Sloc := Sloc (Current_Use_Clause (T));
9148 Error_Msg_NE -- CODEFIX
9149 ("& is already use-visible through previous "
9150 & "use_type_clause #??", Err_No, Id);
9152 -- Case where current use type clause and the use type
9153 -- clause for the type are not both at the compilation unit
9154 -- level. In this case we don't have location information.
9157 Error_Msg_NE -- CODEFIX
9158 ("& is already use-visible through previous "
9159 & "use type clause??", Id, T);
9161 end Use_Clause_Known;
9163 -- Here if Current_Use_Clause is not set for T, another case
9164 -- where we do not have the location information available.
9167 Error_Msg_NE -- CODEFIX
9168 ("& is already use-visible through previous "
9169 & "use type clause??", Id, T);
9172 -- The package where T is declared is already used
9174 elsif In_Use (Scope (T)) then
9175 Error_Msg_Sloc := Sloc (Current_Use_Clause (Scope (T)));
9176 Error_Msg_NE -- CODEFIX
9177 ("& is already use-visible through package use clause #??",
9180 -- The current scope is the package where T is declared
9183 Error_Msg_Node_2 := Scope (T);
9184 Error_Msg_NE -- CODEFIX
9185 ("& is already use-visible inside package &??", Id, T);
9194 procedure Write_Info is
9195 Id : Entity_Id := First_Entity (Current_Scope);
9198 -- No point in dumping standard entities
9200 if Current_Scope = Standard_Standard then
9204 Write_Str ("========================================================");
9206 Write_Str (" Defined Entities in ");
9207 Write_Name (Chars (Current_Scope));
9209 Write_Str ("========================================================");
9213 Write_Str ("-- none --");
9217 while Present (Id) loop
9218 Write_Entity_Info (Id, " ");
9223 if Scope (Current_Scope) = Standard_Standard then
9225 -- Print information on the current unit itself
9227 Write_Entity_Info (Current_Scope, " ");
9240 for J in reverse 1 .. Scope_Stack.Last loop
9241 S := Scope_Stack.Table (J).Entity;
9242 Write_Int (Int (S));
9243 Write_Str (" === ");
9244 Write_Name (Chars (S));
9253 procedure we (S : Entity_Id) is
9256 E := First_Entity (S);
9257 while Present (E) loop
9258 Write_Int (Int (E));
9259 Write_Str (" === ");
9260 Write_Name (Chars (E));