1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2010, 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_Tss; use Exp_Tss;
32 with Exp_Util; use Exp_Util;
33 with Fname; use Fname;
34 with Freeze; use Freeze;
35 with Impunit; use Impunit;
37 with Lib.Load; use Lib.Load;
38 with Lib.Xref; use Lib.Xref;
39 with Namet; use Namet;
40 with Namet.Sp; use Namet.Sp;
41 with Nlists; use Nlists;
42 with Nmake; use Nmake;
44 with Output; use Output;
45 with Restrict; use Restrict;
46 with Rident; use Rident;
47 with Rtsfind; use Rtsfind;
49 with Sem_Aux; use Sem_Aux;
50 with Sem_Cat; use Sem_Cat;
51 with Sem_Ch3; use Sem_Ch3;
52 with Sem_Ch4; use Sem_Ch4;
53 with Sem_Ch6; use Sem_Ch6;
54 with Sem_Ch12; use Sem_Ch12;
55 with Sem_Disp; use Sem_Disp;
56 with Sem_Dist; use Sem_Dist;
57 with Sem_Eval; use Sem_Eval;
58 with Sem_Res; use Sem_Res;
59 with Sem_Util; use Sem_Util;
60 with Sem_Type; use Sem_Type;
61 with Stand; use Stand;
62 with Sinfo; use Sinfo;
63 with Sinfo.CN; use Sinfo.CN;
64 with Snames; use Snames;
65 with Style; use Style;
67 with Tbuild; use Tbuild;
68 with Uintp; use Uintp;
70 package body Sem_Ch8 is
72 ------------------------------------
73 -- Visibility and Name Resolution --
74 ------------------------------------
76 -- This package handles name resolution and the collection of
77 -- interpretations for overloaded names, prior to overload resolution.
79 -- Name resolution is the process that establishes a mapping between source
80 -- identifiers and the entities they denote at each point in the program.
81 -- Each entity is represented by a defining occurrence. Each identifier
82 -- that denotes an entity points to the corresponding defining occurrence.
83 -- This is the entity of the applied occurrence. Each occurrence holds
84 -- an index into the names table, where source identifiers are stored.
86 -- Each entry in the names table for an identifier or designator uses the
87 -- Info pointer to hold a link to the currently visible entity that has
88 -- this name (see subprograms Get_Name_Entity_Id and Set_Name_Entity_Id
89 -- in package Sem_Util). The visibility is initialized at the beginning of
90 -- semantic processing to make entities in package Standard immediately
91 -- visible. The visibility table is used in a more subtle way when
92 -- compiling subunits (see below).
94 -- Entities that have the same name (i.e. homonyms) are chained. In the
95 -- case of overloaded entities, this chain holds all the possible meanings
96 -- of a given identifier. The process of overload resolution uses type
97 -- information to select from this chain the unique meaning of a given
100 -- Entities are also chained in their scope, through the Next_Entity link.
101 -- As a consequence, the name space is organized as a sparse matrix, where
102 -- each row corresponds to a scope, and each column to a source identifier.
103 -- Open scopes, that is to say scopes currently being compiled, have their
104 -- corresponding rows of entities in order, innermost scope first.
106 -- The scopes of packages that are mentioned in context clauses appear in
107 -- no particular order, interspersed among open scopes. This is because
108 -- in the course of analyzing the context of a compilation, a package
109 -- declaration is first an open scope, and subsequently an element of the
110 -- context. If subunits or child units are present, a parent unit may
111 -- appear under various guises at various times in the compilation.
113 -- When the compilation of the innermost scope is complete, the entities
114 -- defined therein are no longer visible. If the scope is not a package
115 -- declaration, these entities are never visible subsequently, and can be
116 -- removed from visibility chains. If the scope is a package declaration,
117 -- its visible declarations may still be accessible. Therefore the entities
118 -- defined in such a scope are left on the visibility chains, and only
119 -- their visibility (immediately visibility or potential use-visibility)
122 -- The ordering of homonyms on their chain does not necessarily follow
123 -- the order of their corresponding scopes on the scope stack. For
124 -- example, if package P and the enclosing scope both contain entities
125 -- named E, then when compiling the package body the chain for E will
126 -- hold the global entity first, and the local one (corresponding to
127 -- the current inner scope) next. As a result, name resolution routines
128 -- do not assume any relative ordering of the homonym chains, either
129 -- for scope nesting or to order of appearance of context clauses.
131 -- When compiling a child unit, entities in the parent scope are always
132 -- immediately visible. When compiling the body of a child unit, private
133 -- entities in the parent must also be made immediately visible. There
134 -- are separate routines to make the visible and private declarations
135 -- visible at various times (see package Sem_Ch7).
137 -- +--------+ +-----+
138 -- | In use |-------->| EU1 |-------------------------->
139 -- +--------+ +-----+
141 -- +--------+ +-----+ +-----+
142 -- | Stand. |---------------->| ES1 |--------------->| ES2 |--->
143 -- +--------+ +-----+ +-----+
145 -- +---------+ | +-----+
146 -- | with'ed |------------------------------>| EW2 |--->
147 -- +---------+ | +-----+
149 -- +--------+ +-----+ +-----+
150 -- | Scope2 |---------------->| E12 |--------------->| E22 |--->
151 -- +--------+ +-----+ +-----+
153 -- +--------+ +-----+ +-----+
154 -- | Scope1 |---------------->| E11 |--------------->| E12 |--->
155 -- +--------+ +-----+ +-----+
159 -- | | with'ed |----------------------------------------->
163 -- (innermost first) | |
164 -- +----------------------------+
165 -- Names table => | Id1 | | | | Id2 |
166 -- +----------------------------+
168 -- Name resolution must deal with several syntactic forms: simple names,
169 -- qualified names, indexed names, and various forms of calls.
171 -- Each identifier points to an entry in the names table. The resolution
172 -- of a simple name consists in traversing the homonym chain, starting
173 -- from the names table. If an entry is immediately visible, it is the one
174 -- designated by the identifier. If only potentially use-visible entities
175 -- are on the chain, we must verify that they do not hide each other. If
176 -- the entity we find is overloadable, we collect all other overloadable
177 -- entities on the chain as long as they are not hidden.
179 -- To resolve expanded names, we must find the entity at the intersection
180 -- of the entity chain for the scope (the prefix) and the homonym chain
181 -- for the selector. In general, homonym chains will be much shorter than
182 -- entity chains, so it is preferable to start from the names table as
183 -- well. If the entity found is overloadable, we must collect all other
184 -- interpretations that are defined in the scope denoted by the prefix.
186 -- For records, protected types, and tasks, their local entities are
187 -- removed from visibility chains on exit from the corresponding scope.
188 -- From the outside, these entities are always accessed by selected
189 -- notation, and the entity chain for the record type, protected type,
190 -- etc. is traversed sequentially in order to find the designated entity.
192 -- The discriminants of a type and the operations of a protected type or
193 -- task are unchained on exit from the first view of the type, (such as
194 -- a private or incomplete type declaration, or a protected type speci-
195 -- fication) and re-chained when compiling the second view.
197 -- In the case of operators, we do not make operators on derived types
198 -- explicit. As a result, the notation P."+" may denote either a user-
199 -- defined function with name "+", or else an implicit declaration of the
200 -- operator "+" in package P. The resolution of expanded names always
201 -- tries to resolve an operator name as such an implicitly defined entity,
202 -- in addition to looking for explicit declarations.
204 -- All forms of names that denote entities (simple names, expanded names,
205 -- character literals in some cases) have a Entity attribute, which
206 -- identifies the entity denoted by the name.
208 ---------------------
209 -- The Scope Stack --
210 ---------------------
212 -- The Scope stack keeps track of the scopes currently been compiled.
213 -- Every entity that contains declarations (including records) is placed
214 -- on the scope stack while it is being processed, and removed at the end.
215 -- Whenever a non-package scope is exited, the entities defined therein
216 -- are removed from the visibility table, so that entities in outer scopes
217 -- become visible (see previous description). On entry to Sem, the scope
218 -- stack only contains the package Standard. As usual, subunits complicate
219 -- this picture ever so slightly.
221 -- The Rtsfind mechanism can force a call to Semantics while another
222 -- compilation is in progress. The unit retrieved by Rtsfind must be
223 -- compiled in its own context, and has no access to the visibility of
224 -- the unit currently being compiled. The procedures Save_Scope_Stack and
225 -- Restore_Scope_Stack make entities in current open scopes invisible
226 -- before compiling the retrieved unit, and restore the compilation
227 -- environment afterwards.
229 ------------------------
230 -- Compiling subunits --
231 ------------------------
233 -- Subunits must be compiled in the environment of the corresponding stub,
234 -- that is to say with the same visibility into the parent (and its
235 -- context) that is available at the point of the stub declaration, but
236 -- with the additional visibility provided by the context clause of the
237 -- subunit itself. As a result, compilation of a subunit forces compilation
238 -- of the parent (see description in lib-). At the point of the stub
239 -- declaration, Analyze is called recursively to compile the proper body of
240 -- the subunit, but without reinitializing the names table, nor the scope
241 -- stack (i.e. standard is not pushed on the stack). In this fashion the
242 -- context of the subunit is added to the context of the parent, and the
243 -- subunit is compiled in the correct environment. Note that in the course
244 -- of processing the context of a subunit, Standard will appear twice on
245 -- the scope stack: once for the parent of the subunit, and once for the
246 -- unit in the context clause being compiled. However, the two sets of
247 -- entities are not linked by homonym chains, so that the compilation of
248 -- any context unit happens in a fresh visibility environment.
250 -------------------------------
251 -- Processing of USE Clauses --
252 -------------------------------
254 -- Every defining occurrence has a flag indicating if it is potentially use
255 -- visible. Resolution of simple names examines this flag. The processing
256 -- of use clauses consists in setting this flag on all visible entities
257 -- defined in the corresponding package. On exit from the scope of the use
258 -- clause, the corresponding flag must be reset. However, a package may
259 -- appear in several nested use clauses (pathological but legal, alas!)
260 -- which forces us to use a slightly more involved scheme:
262 -- a) The defining occurrence for a package holds a flag -In_Use- to
263 -- indicate that it is currently in the scope of a use clause. If a
264 -- redundant use clause is encountered, then the corresponding occurrence
265 -- of the package name is flagged -Redundant_Use-.
267 -- b) On exit from a scope, the use clauses in its declarative part are
268 -- scanned. The visibility flag is reset in all entities declared in
269 -- package named in a use clause, as long as the package is not flagged
270 -- as being in a redundant use clause (in which case the outer use
271 -- clause is still in effect, and the direct visibility of its entities
272 -- must be retained).
274 -- Note that entities are not removed from their homonym chains on exit
275 -- from the package specification. A subsequent use clause does not need
276 -- to rechain the visible entities, but only to establish their direct
279 -----------------------------------
280 -- Handling private declarations --
281 -----------------------------------
283 -- The principle that each entity has a single defining occurrence clashes
284 -- with the presence of two separate definitions for private types: the
285 -- first is the private type declaration, and second is the full type
286 -- declaration. It is important that all references to the type point to
287 -- the same defining occurrence, namely the first one. To enforce the two
288 -- separate views of the entity, the corresponding information is swapped
289 -- between the two declarations. Outside of the package, the defining
290 -- occurrence only contains the private declaration information, while in
291 -- the private part and the body of the package the defining occurrence
292 -- contains the full declaration. To simplify the swap, the defining
293 -- occurrence that currently holds the private declaration points to the
294 -- full declaration. During semantic processing the defining occurrence
295 -- also points to a list of private dependents, that is to say access types
296 -- or composite types whose designated types or component types are
297 -- subtypes or derived types of the private type in question. After the
298 -- full declaration has been seen, the private dependents are updated to
299 -- indicate that they have full definitions.
301 ------------------------------------
302 -- Handling of Undefined Messages --
303 ------------------------------------
305 -- In normal mode, only the first use of an undefined identifier generates
306 -- a message. The table Urefs is used to record error messages that have
307 -- been issued so that second and subsequent ones do not generate further
308 -- messages. However, the second reference causes text to be added to the
309 -- original undefined message noting "(more references follow)". The
310 -- full error list option (-gnatf) forces messages to be generated for
311 -- every reference and disconnects the use of this table.
313 type Uref_Entry is record
315 -- Node for identifier for which original message was posted. The
316 -- Chars field of this identifier is used to detect later references
317 -- to the same identifier.
320 -- Records error message Id of original undefined message. Reset to
321 -- No_Error_Msg after the second occurrence, where it is used to add
322 -- text to the original message as described above.
325 -- Set if the message is not visible rather than undefined
328 -- Records location of error message. Used to make sure that we do
329 -- not consider a, b : undefined as two separate instances, which
330 -- would otherwise happen, since the parser converts this sequence
331 -- to a : undefined; b : undefined.
335 package Urefs is new Table.Table (
336 Table_Component_Type => Uref_Entry,
337 Table_Index_Type => Nat,
338 Table_Low_Bound => 1,
340 Table_Increment => 100,
341 Table_Name => "Urefs");
343 Candidate_Renaming : Entity_Id;
344 -- Holds a candidate interpretation that appears in a subprogram renaming
345 -- declaration and does not match the given specification, but matches at
346 -- least on the first formal. Allows better error message when given
347 -- specification omits defaulted parameters, a common error.
349 -----------------------
350 -- Local Subprograms --
351 -----------------------
353 procedure Analyze_Generic_Renaming
356 -- Common processing for all three kinds of generic renaming declarations.
357 -- Enter new name and indicate that it renames the generic unit.
359 procedure Analyze_Renamed_Character
363 -- Renamed entity is given by a character literal, which must belong
364 -- to the return type of the new entity. Is_Body indicates whether the
365 -- declaration is a renaming_as_body. If the original declaration has
366 -- already been frozen (because of an intervening body, e.g.) the body of
367 -- the function must be built now. The same applies to the following
368 -- various renaming procedures.
370 procedure Analyze_Renamed_Dereference
374 -- Renamed entity is given by an explicit dereference. Prefix must be a
375 -- conformant access_to_subprogram type.
377 procedure Analyze_Renamed_Entry
381 -- If the renamed entity in a subprogram renaming is an entry or protected
382 -- subprogram, build a body for the new entity whose only statement is a
383 -- call to the renamed entity.
385 procedure Analyze_Renamed_Family_Member
389 -- Used when the renamed entity is an indexed component. The prefix must
390 -- denote an entry family.
392 procedure Analyze_Renamed_Primitive_Operation
396 -- If the renamed entity in a subprogram renaming is a primitive operation
397 -- or a class-wide operation in prefix form, save the target object, which
398 -- must be added to the list of actuals in any subsequent call.
400 function Applicable_Use (Pack_Name : Node_Id) return Boolean;
401 -- Common code to Use_One_Package and Set_Use, to determine whether use
402 -- clause must be processed. Pack_Name is an entity name that references
403 -- the package in question.
405 procedure Attribute_Renaming (N : Node_Id);
406 -- Analyze renaming of attribute as subprogram. The renaming declaration N
407 -- is rewritten as a subprogram body that returns the attribute reference
408 -- applied to the formals of the function.
410 procedure Set_Entity_Or_Discriminal (N : Node_Id; E : Entity_Id);
411 -- Set Entity, with style check if need be. For a discriminant reference,
412 -- replace by the corresponding discriminal, i.e. the parameter of the
413 -- initialization procedure that corresponds to the discriminant.
415 procedure Check_Frozen_Renaming (N : Node_Id; Subp : Entity_Id);
416 -- A renaming_as_body may occur after the entity of the original decla-
417 -- ration has been frozen. In that case, the body of the new entity must
418 -- be built now, because the usual mechanism of building the renamed
419 -- body at the point of freezing will not work. Subp is the subprogram
420 -- for which N provides the Renaming_As_Body.
422 procedure Check_In_Previous_With_Clause
425 -- N is a use_package clause and Nam the package name, or N is a use_type
426 -- clause and Nam is the prefix of the type name. In either case, verify
427 -- that the package is visible at that point in the context: either it
428 -- appears in a previous with_clause, or because it is a fully qualified
429 -- name and the root ancestor appears in a previous with_clause.
431 procedure Check_Library_Unit_Renaming (N : Node_Id; Old_E : Entity_Id);
432 -- Verify that the entity in a renaming declaration that is a library unit
433 -- is itself a library unit and not a nested unit or subunit. Also check
434 -- that if the renaming is a child unit of a generic parent, then the
435 -- renamed unit must also be a child unit of that parent. Finally, verify
436 -- that a renamed generic unit is not an implicit child declared within
437 -- an instance of the parent.
439 procedure Chain_Use_Clause (N : Node_Id);
440 -- Chain use clause onto list of uses clauses headed by First_Use_Clause in
441 -- the proper scope table entry. This is usually the current scope, but it
442 -- will be an inner scope when installing the use clauses of the private
443 -- declarations of a parent unit prior to compiling the private part of a
444 -- child unit. This chain is traversed when installing/removing use clauses
445 -- when compiling a subunit or instantiating a generic body on the fly,
446 -- when it is necessary to save and restore full environments.
448 function Has_Implicit_Character_Literal (N : Node_Id) return Boolean;
449 -- Find a type derived from Character or Wide_Character in the prefix of N.
450 -- Used to resolved qualified names whose selector is a character literal.
452 function Has_Private_With (E : Entity_Id) return Boolean;
453 -- Ada 2005 (AI-262): Determines if the current compilation unit has a
454 -- private with on E.
456 procedure Find_Expanded_Name (N : Node_Id);
457 -- The input is a selected component is known to be expanded name. Verify
458 -- legality of selector given the scope denoted by prefix, and change node
459 -- N into a expanded name with a properly set Entity field.
461 function Find_Renamed_Entity
465 Is_Actual : Boolean := False) return Entity_Id;
466 -- Find the renamed entity that corresponds to the given parameter profile
467 -- in a subprogram renaming declaration. The renamed entity may be an
468 -- operator, a subprogram, an entry, or a protected operation. Is_Actual
469 -- indicates that the renaming is the one generated for an actual subpro-
470 -- gram in an instance, for which special visibility checks apply.
472 function Has_Implicit_Operator (N : Node_Id) return Boolean;
473 -- N is an expanded name whose selector is an operator name (e.g. P."+").
474 -- declarative part contains an implicit declaration of an operator if it
475 -- has a declaration of a type to which one of the predefined operators
476 -- apply. The existence of this routine is an implementation artifact. A
477 -- more straightforward but more space-consuming choice would be to make
478 -- all inherited operators explicit in the symbol table.
480 procedure Inherit_Renamed_Profile (New_S : Entity_Id; Old_S : Entity_Id);
481 -- A subprogram defined by a renaming declaration inherits the parameter
482 -- profile of the renamed entity. The subtypes given in the subprogram
483 -- specification are discarded and replaced with those of the renamed
484 -- subprogram, which are then used to recheck the default values.
486 function Is_Appropriate_For_Record (T : Entity_Id) return Boolean;
487 -- Prefix is appropriate for record if it is of a record type, or an access
490 function Is_Appropriate_For_Entry_Prefix (T : Entity_Id) return Boolean;
491 -- True if it is of a task type, a protected type, or else an access to one
494 procedure Note_Redundant_Use (Clause : Node_Id);
495 -- Mark the name in a use clause as redundant if the corresponding entity
496 -- is already use-visible. Emit a warning if the use clause comes from
497 -- source and the proper warnings are enabled.
499 procedure Premature_Usage (N : Node_Id);
500 -- Diagnose usage of an entity before it is visible
502 procedure Use_One_Package (P : Entity_Id; N : Node_Id);
503 -- Make visible entities declared in package P potentially use-visible
504 -- in the current context. Also used in the analysis of subunits, when
505 -- re-installing use clauses of parent units. N is the use_clause that
506 -- names P (and possibly other packages).
508 procedure Use_One_Type (Id : Node_Id);
509 -- Id is the subtype mark from a use type clause. This procedure makes
510 -- the primitive operators of the type potentially use-visible.
512 procedure Write_Info;
513 -- Write debugging information on entities declared in current scope
515 --------------------------------
516 -- Analyze_Exception_Renaming --
517 --------------------------------
519 -- The language only allows a single identifier, but the tree holds an
520 -- identifier list. The parser has already issued an error message if
521 -- there is more than one element in the list.
523 procedure Analyze_Exception_Renaming (N : Node_Id) is
524 Id : constant Node_Id := Defining_Identifier (N);
525 Nam : constant Node_Id := Name (N);
531 Set_Ekind (Id, E_Exception);
532 Set_Exception_Code (Id, Uint_0);
533 Set_Etype (Id, Standard_Exception_Type);
534 Set_Is_Pure (Id, Is_Pure (Current_Scope));
536 if not Is_Entity_Name (Nam) or else
537 Ekind (Entity (Nam)) /= E_Exception
539 Error_Msg_N ("invalid exception name in renaming", Nam);
541 if Present (Renamed_Object (Entity (Nam))) then
542 Set_Renamed_Object (Id, Renamed_Object (Entity (Nam)));
544 Set_Renamed_Object (Id, Entity (Nam));
547 end Analyze_Exception_Renaming;
549 ---------------------------
550 -- Analyze_Expanded_Name --
551 ---------------------------
553 procedure Analyze_Expanded_Name (N : Node_Id) is
555 -- If the entity pointer is already set, this is an internal node, or a
556 -- node that is analyzed more than once, after a tree modification. In
557 -- such a case there is no resolution to perform, just set the type. For
558 -- completeness, analyze prefix as well.
560 if Present (Entity (N)) then
561 if Is_Type (Entity (N)) then
562 Set_Etype (N, Entity (N));
564 Set_Etype (N, Etype (Entity (N)));
567 Analyze (Prefix (N));
570 Find_Expanded_Name (N);
572 end Analyze_Expanded_Name;
574 ---------------------------------------
575 -- Analyze_Generic_Function_Renaming --
576 ---------------------------------------
578 procedure Analyze_Generic_Function_Renaming (N : Node_Id) is
580 Analyze_Generic_Renaming (N, E_Generic_Function);
581 end Analyze_Generic_Function_Renaming;
583 --------------------------------------
584 -- Analyze_Generic_Package_Renaming --
585 --------------------------------------
587 procedure Analyze_Generic_Package_Renaming (N : Node_Id) is
589 -- Apply the Text_IO Kludge here, since we may be renaming one of the
590 -- subpackages of Text_IO, then join common routine.
592 Text_IO_Kludge (Name (N));
594 Analyze_Generic_Renaming (N, E_Generic_Package);
595 end Analyze_Generic_Package_Renaming;
597 ----------------------------------------
598 -- Analyze_Generic_Procedure_Renaming --
599 ----------------------------------------
601 procedure Analyze_Generic_Procedure_Renaming (N : Node_Id) is
603 Analyze_Generic_Renaming (N, E_Generic_Procedure);
604 end Analyze_Generic_Procedure_Renaming;
606 ------------------------------
607 -- Analyze_Generic_Renaming --
608 ------------------------------
610 procedure Analyze_Generic_Renaming
614 New_P : constant Entity_Id := Defining_Entity (N);
616 Inst : Boolean := False; -- prevent junk warning
619 if Name (N) = Error then
623 Generate_Definition (New_P);
625 if Current_Scope /= Standard_Standard then
626 Set_Is_Pure (New_P, Is_Pure (Current_Scope));
629 if Nkind (Name (N)) = N_Selected_Component then
630 Check_Generic_Child_Unit (Name (N), Inst);
635 if not Is_Entity_Name (Name (N)) then
636 Error_Msg_N ("expect entity name in renaming declaration", Name (N));
639 Old_P := Entity (Name (N));
643 Set_Ekind (New_P, K);
645 if Etype (Old_P) = Any_Type then
648 elsif Ekind (Old_P) /= K then
649 Error_Msg_N ("invalid generic unit name", Name (N));
652 if Present (Renamed_Object (Old_P)) then
653 Set_Renamed_Object (New_P, Renamed_Object (Old_P));
655 Set_Renamed_Object (New_P, Old_P);
658 Set_Is_Pure (New_P, Is_Pure (Old_P));
659 Set_Is_Preelaborated (New_P, Is_Preelaborated (Old_P));
661 Set_Etype (New_P, Etype (Old_P));
662 Set_Has_Completion (New_P);
664 if In_Open_Scopes (Old_P) then
665 Error_Msg_N ("within its scope, generic denotes its instance", N);
668 Check_Library_Unit_Renaming (N, Old_P);
670 end Analyze_Generic_Renaming;
672 -----------------------------
673 -- Analyze_Object_Renaming --
674 -----------------------------
676 procedure Analyze_Object_Renaming (N : Node_Id) is
677 Id : constant Entity_Id := Defining_Identifier (N);
679 Nam : constant Node_Id := Name (N);
683 function In_Generic_Scope (E : Entity_Id) return Boolean;
684 -- Determine whether entity E is inside a generic cope
686 ----------------------
687 -- In_Generic_Scope --
688 ----------------------
690 function In_Generic_Scope (E : Entity_Id) return Boolean is
695 while Present (S) and then S /= Standard_Standard loop
696 if Is_Generic_Unit (S) then
704 end In_Generic_Scope;
706 -- Start of processing for Analyze_Object_Renaming
713 Set_Is_Pure (Id, Is_Pure (Current_Scope));
716 -- The renaming of a component that depends on a discriminant requires
717 -- an actual subtype, because in subsequent use of the object Gigi will
718 -- be unable to locate the actual bounds. This explicit step is required
719 -- when the renaming is generated in removing side effects of an
720 -- already-analyzed expression.
722 if Nkind (Nam) = N_Selected_Component
723 and then Analyzed (Nam)
726 Dec := Build_Actual_Subtype_Of_Component (Etype (Nam), Nam);
728 if Present (Dec) then
729 Insert_Action (N, Dec);
730 T := Defining_Identifier (Dec);
734 -- Complete analysis of the subtype mark in any case, for ASIS use
736 if Present (Subtype_Mark (N)) then
737 Find_Type (Subtype_Mark (N));
740 elsif Present (Subtype_Mark (N)) then
741 Find_Type (Subtype_Mark (N));
742 T := Entity (Subtype_Mark (N));
745 if Nkind (Nam) = N_Type_Conversion
746 and then not Is_Tagged_Type (T)
749 ("renaming of conversion only allowed for tagged types", Nam);
754 -- Check that a class-wide object is not being renamed as an object
755 -- of a specific type. The test for access types is needed to exclude
756 -- cases where the renamed object is a dynamically tagged access
757 -- result, such as occurs in certain expansions.
759 if Is_Tagged_Type (T) then
760 Check_Dynamically_Tagged_Expression
766 -- Ada 2005 (AI-230/AI-254): Access renaming
768 else pragma Assert (Present (Access_Definition (N)));
769 T := Access_Definition
771 N => Access_Definition (N));
775 -- Ada 2005 AI05-105: if the declaration has an anonymous access
776 -- type, the renamed object must also have an anonymous type, and
777 -- this is a name resolution rule. This was implicit in the last
778 -- part of the first sentence in 8.5.1.(3/2), and is made explicit
779 -- by this recent AI.
781 if not Is_Overloaded (Nam) then
782 if Ekind (Etype (Nam)) /= Ekind (T) then
784 ("expect anonymous access type in object renaming", N);
791 Typ : Entity_Id := Empty;
792 Seen : Boolean := False;
795 Get_First_Interp (Nam, I, It);
796 while Present (It.Typ) loop
798 -- Renaming is ambiguous if more than one candidate
799 -- interpretation is type-conformant with the context.
801 if Ekind (It.Typ) = Ekind (T) then
802 if Ekind (T) = E_Anonymous_Access_Subprogram_Type
805 (Designated_Type (T), Designated_Type (It.Typ))
811 ("ambiguous expression in renaming", Nam);
814 elsif Ekind (T) = E_Anonymous_Access_Type
816 Covers (Designated_Type (T), Designated_Type (It.Typ))
822 ("ambiguous expression in renaming", Nam);
826 if Covers (T, It.Typ) then
828 Set_Etype (Nam, Typ);
829 Set_Is_Overloaded (Nam, False);
833 Get_Next_Interp (I, It);
840 -- Ada 2005 (AI-231): "In the case where the type is defined by an
841 -- access_definition, the renamed entity shall be of an access-to-
842 -- constant type if and only if the access_definition defines an
843 -- access-to-constant type" ARM 8.5.1(4)
845 if Constant_Present (Access_Definition (N))
846 and then not Is_Access_Constant (Etype (Nam))
848 Error_Msg_N ("(Ada 2005): the renamed object is not "
849 & "access-to-constant (RM 8.5.1(6))", N);
851 elsif not Constant_Present (Access_Definition (N))
852 and then Is_Access_Constant (Etype (Nam))
854 Error_Msg_N ("(Ada 2005): the renamed object is not "
855 & "access-to-variable (RM 8.5.1(6))", N);
858 if Is_Access_Subprogram_Type (Etype (Nam)) then
859 Check_Subtype_Conformant
860 (Designated_Type (T), Designated_Type (Etype (Nam)));
862 elsif not Subtypes_Statically_Match
863 (Designated_Type (T), Designated_Type (Etype (Nam)))
866 ("subtype of renamed object does not statically match", N);
870 -- Special processing for renaming function return object. Some errors
871 -- and warnings are produced only for calls that come from source.
873 if Nkind (Nam) = N_Function_Call then
876 -- Usage is illegal in Ada 83
879 if Comes_From_Source (Nam) then
881 ("(Ada 83) cannot rename function return object", Nam);
884 -- In Ada 95, warn for odd case of renaming parameterless function
885 -- call if this is not a limited type (where this is useful).
888 if Warn_On_Object_Renames_Function
889 and then No (Parameter_Associations (Nam))
890 and then not Is_Limited_Type (Etype (Nam))
891 and then Comes_From_Source (Nam)
894 ("?renaming function result object is suspicious", Nam);
896 ("\?function & will be called only once", Nam,
897 Entity (Name (Nam)));
898 Error_Msg_N -- CODEFIX
899 ("\?suggest using an initialized constant object instead",
903 -- If the function call returns an unconstrained type, we must
904 -- build a constrained subtype for the new entity, in a way
905 -- similar to what is done for an object declaration with an
906 -- unconstrained nominal type.
908 if Is_Composite_Type (Etype (Nam))
909 and then not Is_Constrained (Etype (Nam))
910 and then not Has_Unknown_Discriminants (Etype (Nam))
911 and then Expander_Active
914 Loc : constant Source_Ptr := Sloc (N);
915 Subt : constant Entity_Id := Make_Temporary (Loc, 'T');
917 Remove_Side_Effects (Nam);
919 Make_Subtype_Declaration (Loc,
920 Defining_Identifier => Subt,
921 Subtype_Indication =>
922 Make_Subtype_From_Expr (Nam, Etype (Nam))));
923 Rewrite (Subtype_Mark (N), New_Occurrence_Of (Subt, Loc));
924 Set_Etype (Nam, Subt);
930 -- An object renaming requires an exact match of the type. Class-wide
931 -- matching is not allowed.
933 if Is_Class_Wide_Type (T)
934 and then Base_Type (Etype (Nam)) /= Base_Type (T)
941 -- (Ada 2005: AI-326): Handle wrong use of incomplete type
943 if Nkind (Nam) = N_Explicit_Dereference
944 and then Ekind (Etype (T2)) = E_Incomplete_Type
946 Error_Msg_NE ("invalid use of incomplete type&", Id, T2);
949 elsif Ekind (Etype (T)) = E_Incomplete_Type then
950 Error_Msg_NE ("invalid use of incomplete type&", Id, T);
956 if Ada_Version >= Ada_05
957 and then Nkind (Nam) = N_Attribute_Reference
958 and then Attribute_Name (Nam) = Name_Priority
962 elsif Ada_Version >= Ada_05
963 and then Nkind (Nam) in N_Has_Entity
970 if Nkind (Nam) = N_Attribute_Reference then
971 Nam_Ent := Entity (Prefix (Nam));
973 Nam_Ent := Entity (Nam);
976 Nam_Decl := Parent (Nam_Ent);
978 if Has_Null_Exclusion (N)
979 and then not Has_Null_Exclusion (Nam_Decl)
981 -- Ada 2005 (AI-423): If the object name denotes a generic
982 -- formal object of a generic unit G, and the object renaming
983 -- declaration occurs within the body of G or within the body
984 -- of a generic unit declared within the declarative region
985 -- of G, then the declaration of the formal object of G must
986 -- have a null exclusion or a null-excluding subtype.
988 if Is_Formal_Object (Nam_Ent)
989 and then In_Generic_Scope (Id)
991 if not Can_Never_Be_Null (Etype (Nam_Ent)) then
993 ("renamed formal does not exclude `NULL` "
994 & "(RM 8.5.1(4.6/2))", N);
996 elsif In_Package_Body (Scope (Id)) then
998 ("formal object does not have a null exclusion"
999 & "(RM 8.5.1(4.6/2))", N);
1002 -- Ada 2005 (AI-423): Otherwise, the subtype of the object name
1003 -- shall exclude null.
1005 elsif not Can_Never_Be_Null (Etype (Nam_Ent)) then
1007 ("renamed object does not exclude `NULL` "
1008 & "(RM 8.5.1(4.6/2))", N);
1010 -- An instance is illegal if it contains a renaming that
1011 -- excludes null, and the actual does not. The renaming
1012 -- declaration has already indicated that the declaration
1013 -- of the renamed actual in the instance will raise
1014 -- constraint_error.
1016 elsif Nkind (Nam_Decl) = N_Object_Declaration
1017 and then In_Instance
1019 (Corresponding_Generic_Association (Nam_Decl))
1020 and then Nkind (Expression (Nam_Decl))
1021 = N_Raise_Constraint_Error
1024 ("renamed actual does not exclude `NULL` "
1025 & "(RM 8.5.1(4.6/2))", N);
1027 -- Finally, if there is a null exclusion, the subtype mark
1028 -- must not be null-excluding.
1030 elsif No (Access_Definition (N))
1031 and then Can_Never_Be_Null (T)
1034 ("`NOT NULL` not allowed (& already excludes null)",
1039 elsif Can_Never_Be_Null (T)
1040 and then not Can_Never_Be_Null (Etype (Nam_Ent))
1043 ("renamed object does not exclude `NULL` "
1044 & "(RM 8.5.1(4.6/2))", N);
1046 elsif Has_Null_Exclusion (N)
1047 and then No (Access_Definition (N))
1048 and then Can_Never_Be_Null (T)
1051 ("`NOT NULL` not allowed (& already excludes null)", N, T);
1056 Set_Ekind (Id, E_Variable);
1057 Init_Size_Align (Id);
1059 if T = Any_Type or else Etype (Nam) = Any_Type then
1062 -- Verify that the renamed entity is an object or a function call. It
1063 -- may have been rewritten in several ways.
1065 elsif Is_Object_Reference (Nam) then
1066 if Comes_From_Source (N)
1067 and then Is_Dependent_Component_Of_Mutable_Object (Nam)
1070 ("illegal renaming of discriminant-dependent component", Nam);
1073 -- A static function call may have been folded into a literal
1075 elsif Nkind (Original_Node (Nam)) = N_Function_Call
1077 -- When expansion is disabled, attribute reference is not
1078 -- rewritten as function call. Otherwise it may be rewritten
1079 -- as a conversion, so check original node.
1081 or else (Nkind (Original_Node (Nam)) = N_Attribute_Reference
1082 and then Is_Function_Attribute_Name
1083 (Attribute_Name (Original_Node (Nam))))
1085 -- Weird but legal, equivalent to renaming a function call.
1086 -- Illegal if the literal is the result of constant-folding an
1087 -- attribute reference that is not a function.
1089 or else (Is_Entity_Name (Nam)
1090 and then Ekind (Entity (Nam)) = E_Enumeration_Literal
1092 Nkind (Original_Node (Nam)) /= N_Attribute_Reference)
1094 or else (Nkind (Nam) = N_Type_Conversion
1095 and then Is_Tagged_Type (Entity (Subtype_Mark (Nam))))
1099 elsif Nkind (Nam) = N_Type_Conversion then
1101 ("renaming of conversion only allowed for tagged types", Nam);
1103 -- Ada 2005 (AI-327)
1105 elsif Ada_Version >= Ada_05
1106 and then Nkind (Nam) = N_Attribute_Reference
1107 and then Attribute_Name (Nam) = Name_Priority
1111 -- Allow internally generated x'Reference expression
1113 elsif Nkind (Nam) = N_Reference then
1117 Error_Msg_N ("expect object name in renaming", Nam);
1122 if not Is_Variable (Nam) then
1123 Set_Ekind (Id, E_Constant);
1124 Set_Never_Set_In_Source (Id, True);
1125 Set_Is_True_Constant (Id, True);
1128 Set_Renamed_Object (Id, Nam);
1129 end Analyze_Object_Renaming;
1131 ------------------------------
1132 -- Analyze_Package_Renaming --
1133 ------------------------------
1135 procedure Analyze_Package_Renaming (N : Node_Id) is
1136 New_P : constant Entity_Id := Defining_Entity (N);
1141 if Name (N) = Error then
1145 -- Apply Text_IO kludge here since we may be renaming a child of Text_IO
1147 Text_IO_Kludge (Name (N));
1149 if Current_Scope /= Standard_Standard then
1150 Set_Is_Pure (New_P, Is_Pure (Current_Scope));
1156 if Is_Entity_Name (Name (N)) then
1157 Old_P := Entity (Name (N));
1162 if Etype (Old_P) = Any_Type then
1163 Error_Msg_N ("expect package name in renaming", Name (N));
1165 elsif Ekind (Old_P) /= E_Package
1166 and then not (Ekind (Old_P) = E_Generic_Package
1167 and then In_Open_Scopes (Old_P))
1169 if Ekind (Old_P) = E_Generic_Package then
1171 ("generic package cannot be renamed as a package", Name (N));
1173 Error_Msg_Sloc := Sloc (Old_P);
1175 ("expect package name in renaming, found& declared#",
1179 -- Set basic attributes to minimize cascaded errors
1181 Set_Ekind (New_P, E_Package);
1182 Set_Etype (New_P, Standard_Void_Type);
1184 -- Here for OK package renaming
1187 -- Entities in the old package are accessible through the renaming
1188 -- entity. The simplest implementation is to have both packages share
1191 Set_Ekind (New_P, E_Package);
1192 Set_Etype (New_P, Standard_Void_Type);
1194 if Present (Renamed_Object (Old_P)) then
1195 Set_Renamed_Object (New_P, Renamed_Object (Old_P));
1197 Set_Renamed_Object (New_P, Old_P);
1200 Set_Has_Completion (New_P);
1202 Set_First_Entity (New_P, First_Entity (Old_P));
1203 Set_Last_Entity (New_P, Last_Entity (Old_P));
1204 Set_First_Private_Entity (New_P, First_Private_Entity (Old_P));
1205 Check_Library_Unit_Renaming (N, Old_P);
1206 Generate_Reference (Old_P, Name (N));
1208 -- If the renaming is in the visible part of a package, then we set
1209 -- Renamed_In_Spec for the renamed package, to prevent giving
1210 -- warnings about no entities referenced. Such a warning would be
1211 -- overenthusiastic, since clients can see entities in the renamed
1212 -- package via the visible package renaming.
1215 Ent : constant Entity_Id := Cunit_Entity (Current_Sem_Unit);
1217 if Ekind (Ent) = E_Package
1218 and then not In_Private_Part (Ent)
1219 and then In_Extended_Main_Source_Unit (N)
1220 and then Ekind (Old_P) = E_Package
1222 Set_Renamed_In_Spec (Old_P);
1226 -- If this is the renaming declaration of a package instantiation
1227 -- within itself, it is the declaration that ends the list of actuals
1228 -- for the instantiation. At this point, the subtypes that rename
1229 -- the actuals are flagged as generic, to avoid spurious ambiguities
1230 -- if the actuals for two distinct formals happen to coincide. If
1231 -- the actual is a private type, the subtype has a private completion
1232 -- that is flagged in the same fashion.
1234 -- Resolution is identical to what is was in the original generic.
1235 -- On exit from the generic instance, these are turned into regular
1236 -- subtypes again, so they are compatible with types in their class.
1238 if not Is_Generic_Instance (Old_P) then
1241 Spec := Specification (Unit_Declaration_Node (Old_P));
1244 if Nkind (Spec) = N_Package_Specification
1245 and then Present (Generic_Parent (Spec))
1246 and then Old_P = Current_Scope
1247 and then Chars (New_P) = Chars (Generic_Parent (Spec))
1253 E := First_Entity (Old_P);
1258 and then Nkind (Parent (E)) = N_Subtype_Declaration
1260 Set_Is_Generic_Actual_Type (E);
1262 if Is_Private_Type (E)
1263 and then Present (Full_View (E))
1265 Set_Is_Generic_Actual_Type (Full_View (E));
1274 end Analyze_Package_Renaming;
1276 -------------------------------
1277 -- Analyze_Renamed_Character --
1278 -------------------------------
1280 procedure Analyze_Renamed_Character
1285 C : constant Node_Id := Name (N);
1288 if Ekind (New_S) = E_Function then
1289 Resolve (C, Etype (New_S));
1292 Check_Frozen_Renaming (N, New_S);
1296 Error_Msg_N ("character literal can only be renamed as function", N);
1298 end Analyze_Renamed_Character;
1300 ---------------------------------
1301 -- Analyze_Renamed_Dereference --
1302 ---------------------------------
1304 procedure Analyze_Renamed_Dereference
1309 Nam : constant Node_Id := Name (N);
1310 P : constant Node_Id := Prefix (Nam);
1316 if not Is_Overloaded (P) then
1317 if Ekind (Etype (Nam)) /= E_Subprogram_Type
1318 or else not Type_Conformant (Etype (Nam), New_S)
1320 Error_Msg_N ("designated type does not match specification", P);
1329 Get_First_Interp (Nam, Ind, It);
1331 while Present (It.Nam) loop
1333 if Ekind (It.Nam) = E_Subprogram_Type
1334 and then Type_Conformant (It.Nam, New_S)
1336 if Typ /= Any_Id then
1337 Error_Msg_N ("ambiguous renaming", P);
1344 Get_Next_Interp (Ind, It);
1347 if Typ = Any_Type then
1348 Error_Msg_N ("designated type does not match specification", P);
1353 Check_Frozen_Renaming (N, New_S);
1357 end Analyze_Renamed_Dereference;
1359 ---------------------------
1360 -- Analyze_Renamed_Entry --
1361 ---------------------------
1363 procedure Analyze_Renamed_Entry
1368 Nam : constant Node_Id := Name (N);
1369 Sel : constant Node_Id := Selector_Name (Nam);
1373 if Entity (Sel) = Any_Id then
1375 -- Selector is undefined on prefix. Error emitted already
1377 Set_Has_Completion (New_S);
1381 -- Otherwise find renamed entity and build body of New_S as a call to it
1383 Old_S := Find_Renamed_Entity (N, Selector_Name (Nam), New_S);
1385 if Old_S = Any_Id then
1386 Error_Msg_N (" no subprogram or entry matches specification", N);
1389 Check_Subtype_Conformant (New_S, Old_S, N);
1390 Generate_Reference (New_S, Defining_Entity (N), 'b');
1391 Style.Check_Identifier (Defining_Entity (N), New_S);
1394 -- Only mode conformance required for a renaming_as_declaration
1396 Check_Mode_Conformant (New_S, Old_S, N);
1399 Inherit_Renamed_Profile (New_S, Old_S);
1401 -- The prefix can be an arbitrary expression that yields a task type,
1402 -- so it must be resolved.
1404 Resolve (Prefix (Nam), Scope (Old_S));
1407 Set_Convention (New_S, Convention (Old_S));
1408 Set_Has_Completion (New_S, Inside_A_Generic);
1411 Check_Frozen_Renaming (N, New_S);
1413 end Analyze_Renamed_Entry;
1415 -----------------------------------
1416 -- Analyze_Renamed_Family_Member --
1417 -----------------------------------
1419 procedure Analyze_Renamed_Family_Member
1424 Nam : constant Node_Id := Name (N);
1425 P : constant Node_Id := Prefix (Nam);
1429 if (Is_Entity_Name (P) and then Ekind (Entity (P)) = E_Entry_Family)
1430 or else (Nkind (P) = N_Selected_Component
1432 Ekind (Entity (Selector_Name (P))) = E_Entry_Family)
1434 if Is_Entity_Name (P) then
1435 Old_S := Entity (P);
1437 Old_S := Entity (Selector_Name (P));
1440 if not Entity_Matches_Spec (Old_S, New_S) then
1441 Error_Msg_N ("entry family does not match specification", N);
1444 Check_Subtype_Conformant (New_S, Old_S, N);
1445 Generate_Reference (New_S, Defining_Entity (N), 'b');
1446 Style.Check_Identifier (Defining_Entity (N), New_S);
1450 Error_Msg_N ("no entry family matches specification", N);
1453 Set_Has_Completion (New_S, Inside_A_Generic);
1456 Check_Frozen_Renaming (N, New_S);
1458 end Analyze_Renamed_Family_Member;
1460 -----------------------------------------
1461 -- Analyze_Renamed_Primitive_Operation --
1462 -----------------------------------------
1464 procedure Analyze_Renamed_Primitive_Operation
1473 Ctyp : Conformance_Type) return Boolean;
1474 -- Verify that the signatures of the renamed entity and the new entity
1475 -- match. The first formal of the renamed entity is skipped because it
1476 -- is the target object in any subsequent call.
1480 Ctyp : Conformance_Type) return Boolean
1486 if Ekind (Subp) /= Ekind (New_S) then
1490 Old_F := Next_Formal (First_Formal (Subp));
1491 New_F := First_Formal (New_S);
1492 while Present (Old_F) and then Present (New_F) loop
1493 if not Conforming_Types (Etype (Old_F), Etype (New_F), Ctyp) then
1497 if Ctyp >= Mode_Conformant
1498 and then Ekind (Old_F) /= Ekind (New_F)
1503 Next_Formal (New_F);
1504 Next_Formal (Old_F);
1511 if not Is_Overloaded (Selector_Name (Name (N))) then
1512 Old_S := Entity (Selector_Name (Name (N)));
1514 if not Conforms (Old_S, Type_Conformant) then
1519 -- Find the operation that matches the given signature
1527 Get_First_Interp (Selector_Name (Name (N)), Ind, It);
1529 while Present (It.Nam) loop
1530 if Conforms (It.Nam, Type_Conformant) then
1534 Get_Next_Interp (Ind, It);
1539 if Old_S = Any_Id then
1540 Error_Msg_N (" no subprogram or entry matches specification", N);
1544 if not Conforms (Old_S, Subtype_Conformant) then
1545 Error_Msg_N ("subtype conformance error in renaming", N);
1548 Generate_Reference (New_S, Defining_Entity (N), 'b');
1549 Style.Check_Identifier (Defining_Entity (N), New_S);
1552 -- Only mode conformance required for a renaming_as_declaration
1554 if not Conforms (Old_S, Mode_Conformant) then
1555 Error_Msg_N ("mode conformance error in renaming", N);
1559 -- Inherit_Renamed_Profile (New_S, Old_S);
1561 -- The prefix can be an arbitrary expression that yields an
1562 -- object, so it must be resolved.
1564 Resolve (Prefix (Name (N)));
1566 end Analyze_Renamed_Primitive_Operation;
1568 ---------------------------------
1569 -- Analyze_Subprogram_Renaming --
1570 ---------------------------------
1572 procedure Analyze_Subprogram_Renaming (N : Node_Id) is
1573 Formal_Spec : constant Node_Id := Corresponding_Formal_Spec (N);
1574 Is_Actual : constant Boolean := Present (Formal_Spec);
1575 Inst_Node : Node_Id := Empty;
1576 Nam : constant Node_Id := Name (N);
1578 Old_S : Entity_Id := Empty;
1579 Rename_Spec : Entity_Id;
1580 Save_AV : constant Ada_Version_Type := Ada_Version;
1581 Save_AV_Exp : constant Ada_Version_Type := Ada_Version_Explicit;
1582 Spec : constant Node_Id := Specification (N);
1584 procedure Check_Null_Exclusion
1587 -- Ada 2005 (AI-423): Given renaming Ren of subprogram Sub, check the
1588 -- following AI rules:
1590 -- If Ren is a renaming of a formal subprogram and one of its
1591 -- parameters has a null exclusion, then the corresponding formal
1592 -- in Sub must also have one. Otherwise the subtype of the Sub's
1593 -- formal parameter must exclude null.
1595 -- If Ren is a renaming of a formal function and its return
1596 -- profile has a null exclusion, then Sub's return profile must
1597 -- have one. Otherwise the subtype of Sub's return profile must
1600 function Original_Subprogram (Subp : Entity_Id) return Entity_Id;
1601 -- Find renamed entity when the declaration is a renaming_as_body and
1602 -- the renamed entity may itself be a renaming_as_body. Used to enforce
1603 -- rule that a renaming_as_body is illegal if the declaration occurs
1604 -- before the subprogram it completes is frozen, and renaming indirectly
1605 -- renames the subprogram itself.(Defect Report 8652/0027).
1607 --------------------------
1608 -- Check_Null_Exclusion --
1609 --------------------------
1611 procedure Check_Null_Exclusion
1615 Ren_Formal : Entity_Id;
1616 Sub_Formal : Entity_Id;
1621 Ren_Formal := First_Formal (Ren);
1622 Sub_Formal := First_Formal (Sub);
1623 while Present (Ren_Formal)
1624 and then Present (Sub_Formal)
1626 if Has_Null_Exclusion (Parent (Ren_Formal))
1628 not (Has_Null_Exclusion (Parent (Sub_Formal))
1629 or else Can_Never_Be_Null (Etype (Sub_Formal)))
1632 ("`NOT NULL` required for parameter &",
1633 Parent (Sub_Formal), Sub_Formal);
1636 Next_Formal (Ren_Formal);
1637 Next_Formal (Sub_Formal);
1640 -- Return profile check
1642 if Nkind (Parent (Ren)) = N_Function_Specification
1643 and then Nkind (Parent (Sub)) = N_Function_Specification
1644 and then Has_Null_Exclusion (Parent (Ren))
1646 not (Has_Null_Exclusion (Parent (Sub))
1647 or else Can_Never_Be_Null (Etype (Sub)))
1650 ("return must specify `NOT NULL`",
1651 Result_Definition (Parent (Sub)));
1653 end Check_Null_Exclusion;
1655 -------------------------
1656 -- Original_Subprogram --
1657 -------------------------
1659 function Original_Subprogram (Subp : Entity_Id) return Entity_Id is
1660 Orig_Decl : Node_Id;
1661 Orig_Subp : Entity_Id;
1664 -- First case: renamed entity is itself a renaming
1666 if Present (Alias (Subp)) then
1667 return Alias (Subp);
1670 Nkind (Unit_Declaration_Node (Subp)) = N_Subprogram_Declaration
1672 (Corresponding_Body (Unit_Declaration_Node (Subp)))
1674 -- Check if renamed entity is a renaming_as_body
1677 Unit_Declaration_Node
1678 (Corresponding_Body (Unit_Declaration_Node (Subp)));
1680 if Nkind (Orig_Decl) = N_Subprogram_Renaming_Declaration then
1681 Orig_Subp := Entity (Name (Orig_Decl));
1683 if Orig_Subp = Rename_Spec then
1685 -- Circularity detected
1690 return (Original_Subprogram (Orig_Subp));
1698 end Original_Subprogram;
1700 -- Start of processing for Analyze_Subprogram_Renaming
1703 -- We must test for the attribute renaming case before the Analyze
1704 -- call because otherwise Sem_Attr will complain that the attribute
1705 -- is missing an argument when it is analyzed.
1707 if Nkind (Nam) = N_Attribute_Reference then
1709 -- In the case of an abstract formal subprogram association, rewrite
1710 -- an actual given by a stream attribute as the name of the
1711 -- corresponding stream primitive of the type.
1713 -- In a generic context the stream operations are not generated, and
1714 -- this must be treated as a normal attribute reference, to be
1715 -- expanded in subsequent instantiations.
1717 if Is_Actual and then Is_Abstract_Subprogram (Formal_Spec)
1718 and then Expander_Active
1721 Stream_Prim : Entity_Id;
1722 Prefix_Type : constant Entity_Id := Entity (Prefix (Nam));
1725 -- The class-wide forms of the stream attributes are not
1726 -- primitive dispatching operations (even though they
1727 -- internally dispatch to a stream attribute).
1729 if Is_Class_Wide_Type (Prefix_Type) then
1731 ("attribute must be a primitive dispatching operation",
1736 -- Retrieve the primitive subprogram associated with the
1737 -- attribute. This can only be a stream attribute, since those
1738 -- are the only ones that are dispatching (and the actual for
1739 -- an abstract formal subprogram must be dispatching
1743 case Attribute_Name (Nam) is
1746 Find_Prim_Op (Prefix_Type, TSS_Stream_Input);
1749 Find_Prim_Op (Prefix_Type, TSS_Stream_Output);
1752 Find_Prim_Op (Prefix_Type, TSS_Stream_Read);
1755 Find_Prim_Op (Prefix_Type, TSS_Stream_Write);
1758 ("attribute must be a primitive"
1759 & " dispatching operation", Nam);
1765 -- If no operation was found, and the type is limited,
1766 -- the user should have defined one.
1768 when Program_Error =>
1769 if Is_Limited_Type (Prefix_Type) then
1771 ("stream operation not defined for type&",
1775 -- Otherwise, compiler should have generated default
1782 -- Rewrite the attribute into the name of its corresponding
1783 -- primitive dispatching subprogram. We can then proceed with
1784 -- the usual processing for subprogram renamings.
1787 Prim_Name : constant Node_Id :=
1788 Make_Identifier (Sloc (Nam),
1789 Chars => Chars (Stream_Prim));
1791 Set_Entity (Prim_Name, Stream_Prim);
1792 Rewrite (Nam, Prim_Name);
1797 -- Normal processing for a renaming of an attribute
1800 Attribute_Renaming (N);
1805 -- Check whether this declaration corresponds to the instantiation
1806 -- of a formal subprogram.
1808 -- If this is an instantiation, the corresponding actual is frozen and
1809 -- error messages can be made more precise. If this is a default
1810 -- subprogram, the entity is already established in the generic, and is
1811 -- not retrieved by visibility. If it is a default with a box, the
1812 -- candidate interpretations, if any, have been collected when building
1813 -- the renaming declaration. If overloaded, the proper interpretation is
1814 -- determined in Find_Renamed_Entity. If the entity is an operator,
1815 -- Find_Renamed_Entity applies additional visibility checks.
1818 Inst_Node := Unit_Declaration_Node (Formal_Spec);
1820 if Is_Entity_Name (Nam)
1821 and then Present (Entity (Nam))
1822 and then not Comes_From_Source (Nam)
1823 and then not Is_Overloaded (Nam)
1825 Old_S := Entity (Nam);
1826 New_S := Analyze_Subprogram_Specification (Spec);
1830 if Ekind (Entity (Nam)) = E_Operator then
1834 if Box_Present (Inst_Node) then
1835 Old_S := Find_Renamed_Entity (N, Name (N), New_S, Is_Actual);
1837 -- If there is an immediately visible homonym of the operator
1838 -- and the declaration has a default, this is worth a warning
1839 -- because the user probably did not intend to get the pre-
1840 -- defined operator, visible in the generic declaration. To
1841 -- find if there is an intended candidate, analyze the renaming
1842 -- again in the current context.
1844 elsif Scope (Old_S) = Standard_Standard
1845 and then Present (Default_Name (Inst_Node))
1848 Decl : constant Node_Id := New_Copy_Tree (N);
1852 Set_Entity (Name (Decl), Empty);
1853 Analyze (Name (Decl));
1855 Find_Renamed_Entity (Decl, Name (Decl), New_S, True);
1858 and then In_Open_Scopes (Scope (Hidden))
1859 and then Is_Immediately_Visible (Hidden)
1860 and then Comes_From_Source (Hidden)
1861 and then Hidden /= Old_S
1863 Error_Msg_Sloc := Sloc (Hidden);
1864 Error_Msg_N ("?default subprogram is resolved " &
1865 "in the generic declaration " &
1866 "(RM 12.6(17))", N);
1867 Error_Msg_NE ("\?and will not use & #", N, Hidden);
1875 New_S := Analyze_Subprogram_Specification (Spec);
1879 -- Renamed entity must be analyzed first, to avoid being hidden by
1880 -- new name (which might be the same in a generic instance).
1884 -- The renaming defines a new overloaded entity, which is analyzed
1885 -- like a subprogram declaration.
1887 New_S := Analyze_Subprogram_Specification (Spec);
1890 if Current_Scope /= Standard_Standard then
1891 Set_Is_Pure (New_S, Is_Pure (Current_Scope));
1894 Rename_Spec := Find_Corresponding_Spec (N);
1896 -- Case of Renaming_As_Body
1898 if Present (Rename_Spec) then
1900 -- Renaming declaration is the completion of the declaration of
1901 -- Rename_Spec. We build an actual body for it at the freezing point.
1903 Set_Corresponding_Spec (N, Rename_Spec);
1905 -- Deal with special case of stream functions of abstract types
1908 if Nkind (Unit_Declaration_Node (Rename_Spec)) =
1909 N_Abstract_Subprogram_Declaration
1911 -- Input stream functions are abstract if the object type is
1912 -- abstract. Similarly, all default stream functions for an
1913 -- interface type are abstract. However, these subprograms may
1914 -- receive explicit declarations in representation clauses, making
1915 -- the attribute subprograms usable as defaults in subsequent
1917 -- In this case we rewrite the declaration to make the subprogram
1918 -- non-abstract. We remove the previous declaration, and insert
1919 -- the new one at the point of the renaming, to prevent premature
1920 -- access to unfrozen types. The new declaration reuses the
1921 -- specification of the previous one, and must not be analyzed.
1924 (Is_Primitive (Entity (Nam))
1926 Is_Abstract_Type (Find_Dispatching_Type (Entity (Nam))));
1928 Old_Decl : constant Node_Id :=
1929 Unit_Declaration_Node (Rename_Spec);
1930 New_Decl : constant Node_Id :=
1931 Make_Subprogram_Declaration (Sloc (N),
1933 Relocate_Node (Specification (Old_Decl)));
1936 Insert_After (N, New_Decl);
1937 Set_Is_Abstract_Subprogram (Rename_Spec, False);
1938 Set_Analyzed (New_Decl);
1942 Set_Corresponding_Body (Unit_Declaration_Node (Rename_Spec), New_S);
1944 if Ada_Version = Ada_83 and then Comes_From_Source (N) then
1945 Error_Msg_N ("(Ada 83) renaming cannot serve as a body", N);
1948 Set_Convention (New_S, Convention (Rename_Spec));
1949 Check_Fully_Conformant (New_S, Rename_Spec);
1950 Set_Public_Status (New_S);
1952 -- The specification does not introduce new formals, but only
1953 -- repeats the formals of the original subprogram declaration.
1954 -- For cross-reference purposes, and for refactoring tools, we
1955 -- treat the formals of the renaming declaration as body formals.
1957 Reference_Body_Formals (Rename_Spec, New_S);
1959 -- Indicate that the entity in the declaration functions like the
1960 -- corresponding body, and is not a new entity. The body will be
1961 -- constructed later at the freeze point, so indicate that the
1962 -- completion has not been seen yet.
1964 Set_Ekind (New_S, E_Subprogram_Body);
1965 New_S := Rename_Spec;
1966 Set_Has_Completion (Rename_Spec, False);
1968 -- Ada 2005: check overriding indicator
1970 if Is_Overriding_Operation (Rename_Spec) then
1971 if Must_Not_Override (Specification (N)) then
1973 ("subprogram& overrides inherited operation",
1976 Style_Check and then not Must_Override (Specification (N))
1978 Style.Missing_Overriding (N, Rename_Spec);
1981 elsif Must_Override (Specification (N)) then
1982 Error_Msg_NE ("subprogram& is not overriding", N, Rename_Spec);
1985 -- Normal subprogram renaming (not renaming as body)
1988 Generate_Definition (New_S);
1989 New_Overloaded_Entity (New_S);
1991 if Is_Entity_Name (Nam)
1992 and then Is_Intrinsic_Subprogram (Entity (Nam))
1996 Check_Delayed_Subprogram (New_S);
2000 -- There is no need for elaboration checks on the new entity, which may
2001 -- be called before the next freezing point where the body will appear.
2002 -- Elaboration checks refer to the real entity, not the one created by
2003 -- the renaming declaration.
2005 Set_Kill_Elaboration_Checks (New_S, True);
2007 if Etype (Nam) = Any_Type then
2008 Set_Has_Completion (New_S);
2011 elsif Nkind (Nam) = N_Selected_Component then
2013 -- A prefix of the form A.B can designate an entry of task A, a
2014 -- protected operation of protected object A, or finally a primitive
2015 -- operation of object A. In the later case, A is an object of some
2016 -- tagged type, or an access type that denotes one such. To further
2017 -- distinguish these cases, note that the scope of a task entry or
2018 -- protected operation is type of the prefix.
2020 -- The prefix could be an overloaded function call that returns both
2021 -- kinds of operations. This overloading pathology is left to the
2022 -- dedicated reader ???
2025 T : constant Entity_Id := Etype (Prefix (Nam));
2034 Is_Tagged_Type (Designated_Type (T))))
2035 and then Scope (Entity (Selector_Name (Nam))) /= T
2037 Analyze_Renamed_Primitive_Operation
2038 (N, New_S, Present (Rename_Spec));
2042 -- Renamed entity is an entry or protected operation. For those
2043 -- cases an explicit body is built (at the point of freezing of
2044 -- this entity) that contains a call to the renamed entity.
2046 -- This is not allowed for renaming as body if the renamed
2047 -- spec is already frozen (see RM 8.5.4(5) for details).
2049 if Present (Rename_Spec)
2050 and then Is_Frozen (Rename_Spec)
2053 ("renaming-as-body cannot rename entry as subprogram", N);
2055 ("\since & is already frozen (RM 8.5.4(5))",
2058 Analyze_Renamed_Entry (N, New_S, Present (Rename_Spec));
2065 elsif Nkind (Nam) = N_Explicit_Dereference then
2067 -- Renamed entity is designated by access_to_subprogram expression.
2068 -- Must build body to encapsulate call, as in the entry case.
2070 Analyze_Renamed_Dereference (N, New_S, Present (Rename_Spec));
2073 elsif Nkind (Nam) = N_Indexed_Component then
2074 Analyze_Renamed_Family_Member (N, New_S, Present (Rename_Spec));
2077 elsif Nkind (Nam) = N_Character_Literal then
2078 Analyze_Renamed_Character (N, New_S, Present (Rename_Spec));
2081 elsif not Is_Entity_Name (Nam)
2082 or else not Is_Overloadable (Entity (Nam))
2084 Error_Msg_N ("expect valid subprogram name in renaming", N);
2088 -- Find the renamed entity that matches the given specification. Disable
2089 -- Ada_83 because there is no requirement of full conformance between
2090 -- renamed entity and new entity, even though the same circuit is used.
2092 -- This is a bit of a kludge, which introduces a really irregular use of
2093 -- Ada_Version[_Explicit]. Would be nice to find cleaner way to do this
2096 Ada_Version := Ada_Version_Type'Max (Ada_Version, Ada_95);
2097 Ada_Version_Explicit := Ada_Version;
2100 Old_S := Find_Renamed_Entity (N, Name (N), New_S, Is_Actual);
2102 -- The visible operation may be an inherited abstract operation that
2103 -- was overridden in the private part, in which case a call will
2104 -- dispatch to the overriding operation. Use the overriding one in
2105 -- the renaming declaration, to prevent spurious errors below.
2107 if Is_Overloadable (Old_S)
2108 and then Is_Abstract_Subprogram (Old_S)
2109 and then No (DTC_Entity (Old_S))
2110 and then Present (Alias (Old_S))
2111 and then not Is_Abstract_Subprogram (Alias (Old_S))
2112 and then Is_Overriding_Operation (Alias (Old_S))
2114 Old_S := Alias (Old_S);
2117 -- When the renamed subprogram is overloaded and used as an actual
2118 -- of a generic, its entity is set to the first available homonym.
2119 -- We must first disambiguate the name, then set the proper entity.
2122 and then Is_Overloaded (Nam)
2124 Set_Entity (Nam, Old_S);
2128 -- Most common case: subprogram renames subprogram. No body is generated
2129 -- in this case, so we must indicate the declaration is complete as is.
2130 -- and inherit various attributes of the renamed subprogram.
2132 if No (Rename_Spec) then
2133 Set_Has_Completion (New_S);
2134 Set_Is_Imported (New_S, Is_Imported (Entity (Nam)));
2135 Set_Is_Pure (New_S, Is_Pure (Entity (Nam)));
2136 Set_Is_Preelaborated (New_S, Is_Preelaborated (Entity (Nam)));
2138 -- Ada 2005 (AI-423): Check the consistency of null exclusions
2139 -- between a subprogram and its correct renaming.
2141 -- Note: the Any_Id check is a guard that prevents compiler crashes
2142 -- when performing a null exclusion check between a renaming and a
2143 -- renamed subprogram that has been found to be illegal.
2145 if Ada_Version >= Ada_05
2146 and then Entity (Nam) /= Any_Id
2148 Check_Null_Exclusion
2150 Sub => Entity (Nam));
2153 -- Enforce the Ada 2005 rule that the renamed entity cannot require
2154 -- overriding. The flag Requires_Overriding is set very selectively
2155 -- and misses some other illegal cases. The additional conditions
2156 -- checked below are sufficient but not necessary ???
2158 -- The rule does not apply to the renaming generated for an actual
2159 -- subprogram in an instance.
2164 -- Guard against previous errors, and omit renamings of predefined
2167 elsif not Ekind_In (Old_S, E_Function, E_Procedure) then
2170 elsif Requires_Overriding (Old_S)
2172 (Is_Abstract_Subprogram (Old_S)
2173 and then Present (Find_Dispatching_Type (Old_S))
2175 not Is_Abstract_Type (Find_Dispatching_Type (Old_S)))
2178 ("renamed entity cannot be "
2179 & "subprogram that requires overriding (RM 8.5.4 (5.1))", N);
2183 if Old_S /= Any_Id then
2185 and then From_Default (N)
2187 -- This is an implicit reference to the default actual
2189 Generate_Reference (Old_S, Nam, Typ => 'i', Force => True);
2191 Generate_Reference (Old_S, Nam);
2194 -- For a renaming-as-body, require subtype conformance, but if the
2195 -- declaration being completed has not been frozen, then inherit the
2196 -- convention of the renamed subprogram prior to checking conformance
2197 -- (unless the renaming has an explicit convention established; the
2198 -- rule stated in the RM doesn't seem to address this ???).
2200 if Present (Rename_Spec) then
2201 Generate_Reference (Rename_Spec, Defining_Entity (Spec), 'b');
2202 Style.Check_Identifier (Defining_Entity (Spec), Rename_Spec);
2204 if not Is_Frozen (Rename_Spec) then
2205 if not Has_Convention_Pragma (Rename_Spec) then
2206 Set_Convention (New_S, Convention (Old_S));
2209 if Ekind (Old_S) /= E_Operator then
2210 Check_Mode_Conformant (New_S, Old_S, Spec);
2213 if Original_Subprogram (Old_S) = Rename_Spec then
2214 Error_Msg_N ("unfrozen subprogram cannot rename itself ", N);
2217 Check_Subtype_Conformant (New_S, Old_S, Spec);
2220 Check_Frozen_Renaming (N, Rename_Spec);
2222 -- Check explicitly that renamed entity is not intrinsic, because
2223 -- in a generic the renamed body is not built. In this case,
2224 -- the renaming_as_body is a completion.
2226 if Inside_A_Generic then
2227 if Is_Frozen (Rename_Spec)
2228 and then Is_Intrinsic_Subprogram (Old_S)
2231 ("subprogram in renaming_as_body cannot be intrinsic",
2235 Set_Has_Completion (Rename_Spec);
2238 elsif Ekind (Old_S) /= E_Operator then
2239 Check_Mode_Conformant (New_S, Old_S);
2242 and then Error_Posted (New_S)
2244 Error_Msg_NE ("invalid actual subprogram: & #!", N, Old_S);
2248 if No (Rename_Spec) then
2250 -- The parameter profile of the new entity is that of the renamed
2251 -- entity: the subtypes given in the specification are irrelevant.
2253 Inherit_Renamed_Profile (New_S, Old_S);
2255 -- A call to the subprogram is transformed into a call to the
2256 -- renamed entity. This is transitive if the renamed entity is
2257 -- itself a renaming.
2259 if Present (Alias (Old_S)) then
2260 Set_Alias (New_S, Alias (Old_S));
2262 Set_Alias (New_S, Old_S);
2265 -- Note that we do not set Is_Intrinsic_Subprogram if we have a
2266 -- renaming as body, since the entity in this case is not an
2267 -- intrinsic (it calls an intrinsic, but we have a real body for
2268 -- this call, and it is in this body that the required intrinsic
2269 -- processing will take place).
2271 -- Also, if this is a renaming of inequality, the renamed operator
2272 -- is intrinsic, but what matters is the corresponding equality
2273 -- operator, which may be user-defined.
2275 Set_Is_Intrinsic_Subprogram
2277 Is_Intrinsic_Subprogram (Old_S)
2279 (Chars (Old_S) /= Name_Op_Ne
2280 or else Ekind (Old_S) = E_Operator
2282 Is_Intrinsic_Subprogram
2283 (Corresponding_Equality (Old_S))));
2285 if Ekind (Alias (New_S)) = E_Operator then
2286 Set_Has_Delayed_Freeze (New_S, False);
2289 -- If the renaming corresponds to an association for an abstract
2290 -- formal subprogram, then various attributes must be set to
2291 -- indicate that the renaming is an abstract dispatching operation
2292 -- with a controlling type.
2294 if Is_Actual and then Is_Abstract_Subprogram (Formal_Spec) then
2296 -- Mark the renaming as abstract here, so Find_Dispatching_Type
2297 -- see it as corresponding to a generic association for a
2298 -- formal abstract subprogram
2300 Set_Is_Abstract_Subprogram (New_S);
2303 New_S_Ctrl_Type : constant Entity_Id :=
2304 Find_Dispatching_Type (New_S);
2305 Old_S_Ctrl_Type : constant Entity_Id :=
2306 Find_Dispatching_Type (Old_S);
2309 if Old_S_Ctrl_Type /= New_S_Ctrl_Type then
2311 ("actual must be dispatching subprogram for type&",
2312 Nam, New_S_Ctrl_Type);
2315 Set_Is_Dispatching_Operation (New_S);
2316 Check_Controlling_Formals (New_S_Ctrl_Type, New_S);
2318 -- If the actual in the formal subprogram is itself a
2319 -- formal abstract subprogram association, there's no
2320 -- dispatch table component or position to inherit.
2322 if Present (DTC_Entity (Old_S)) then
2323 Set_DTC_Entity (New_S, DTC_Entity (Old_S));
2324 Set_DT_Position (New_S, DT_Position (Old_S));
2332 and then (Old_S = New_S
2333 or else (Nkind (Nam) /= N_Expanded_Name
2334 and then Chars (Old_S) = Chars (New_S)))
2336 Error_Msg_N ("subprogram cannot rename itself", N);
2339 Set_Convention (New_S, Convention (Old_S));
2341 if Is_Abstract_Subprogram (Old_S) then
2342 if Present (Rename_Spec) then
2344 ("a renaming-as-body cannot rename an abstract subprogram",
2346 Set_Has_Completion (Rename_Spec);
2348 Set_Is_Abstract_Subprogram (New_S);
2352 Check_Library_Unit_Renaming (N, Old_S);
2354 -- Pathological case: procedure renames entry in the scope of its
2355 -- task. Entry is given by simple name, but body must be built for
2356 -- procedure. Of course if called it will deadlock.
2358 if Ekind (Old_S) = E_Entry then
2359 Set_Has_Completion (New_S, False);
2360 Set_Alias (New_S, Empty);
2364 Freeze_Before (N, Old_S);
2365 Set_Has_Delayed_Freeze (New_S, False);
2366 Freeze_Before (N, New_S);
2368 -- An abstract subprogram is only allowed as an actual in the case
2369 -- where the formal subprogram is also abstract.
2371 if (Ekind (Old_S) = E_Procedure or else Ekind (Old_S) = E_Function)
2372 and then Is_Abstract_Subprogram (Old_S)
2373 and then not Is_Abstract_Subprogram (Formal_Spec)
2376 ("abstract subprogram not allowed as generic actual", Nam);
2381 -- A common error is to assume that implicit operators for types are
2382 -- defined in Standard, or in the scope of a subtype. In those cases
2383 -- where the renamed entity is given with an expanded name, it is
2384 -- worth mentioning that operators for the type are not declared in
2385 -- the scope given by the prefix.
2387 if Nkind (Nam) = N_Expanded_Name
2388 and then Nkind (Selector_Name (Nam)) = N_Operator_Symbol
2389 and then Scope (Entity (Nam)) = Standard_Standard
2392 T : constant Entity_Id :=
2393 Base_Type (Etype (First_Formal (New_S)));
2395 Error_Msg_Node_2 := Prefix (Nam);
2397 ("operator for type& is not declared in&", Prefix (Nam), T);
2402 ("no visible subprogram matches the specification for&",
2406 if Present (Candidate_Renaming) then
2413 F1 := First_Formal (Candidate_Renaming);
2414 F2 := First_Formal (New_S);
2415 T1 := First_Subtype (Etype (F1));
2417 while Present (F1) and then Present (F2) loop
2422 if Present (F1) and then Present (Default_Value (F1)) then
2423 if Present (Next_Formal (F1)) then
2425 ("\missing specification for &" &
2426 " and other formals with defaults", Spec, F1);
2429 ("\missing specification for &", Spec, F1);
2433 if Nkind (Nam) = N_Operator_Symbol
2434 and then From_Default (N)
2436 Error_Msg_Node_2 := T1;
2438 ("default & on & is not directly visible",
2445 -- Ada 2005 AI 404: if the new subprogram is dispatching, verify that
2446 -- controlling access parameters are known non-null for the renamed
2447 -- subprogram. Test also applies to a subprogram instantiation that
2448 -- is dispatching. Test is skipped if some previous error was detected
2449 -- that set Old_S to Any_Id.
2451 if Ada_Version >= Ada_05
2452 and then Old_S /= Any_Id
2453 and then not Is_Dispatching_Operation (Old_S)
2454 and then Is_Dispatching_Operation (New_S)
2461 Old_F := First_Formal (Old_S);
2462 New_F := First_Formal (New_S);
2463 while Present (Old_F) loop
2464 if Ekind (Etype (Old_F)) = E_Anonymous_Access_Type
2465 and then Is_Controlling_Formal (New_F)
2466 and then not Can_Never_Be_Null (Old_F)
2468 Error_Msg_N ("access parameter is controlling,", New_F);
2470 ("\corresponding parameter of& "
2471 & "must be explicitly null excluding", New_F, Old_S);
2474 Next_Formal (Old_F);
2475 Next_Formal (New_F);
2480 -- A useful warning, suggested by Ada Bug Finder (Ada-Europe 2005)
2481 -- is to warn if an operator is being renamed as a different operator.
2483 if Comes_From_Source (N)
2484 and then Present (Old_S)
2485 and then Nkind (Old_S) = N_Defining_Operator_Symbol
2486 and then Nkind (New_S) = N_Defining_Operator_Symbol
2487 and then Chars (Old_S) /= Chars (New_S)
2490 ("?& is being renamed as a different operator",
2494 -- Check for renaming of obsolescent subprogram
2496 Check_Obsolescent_2005_Entity (Entity (Nam), Nam);
2498 -- Another warning or some utility: if the new subprogram as the same
2499 -- name as the old one, the old one is not hidden by an outer homograph,
2500 -- the new one is not a public symbol, and the old one is otherwise
2501 -- directly visible, the renaming is superfluous.
2503 if Chars (Old_S) = Chars (New_S)
2504 and then Comes_From_Source (N)
2505 and then Scope (Old_S) /= Standard_Standard
2506 and then Warn_On_Redundant_Constructs
2508 (Is_Immediately_Visible (Old_S)
2509 or else Is_Potentially_Use_Visible (Old_S))
2510 and then Is_Overloadable (Current_Scope)
2511 and then Chars (Current_Scope) /= Chars (Old_S)
2514 ("?redundant renaming, entity is directly visible", Name (N));
2517 Ada_Version := Save_AV;
2518 Ada_Version_Explicit := Save_AV_Exp;
2519 end Analyze_Subprogram_Renaming;
2521 -------------------------
2522 -- Analyze_Use_Package --
2523 -------------------------
2525 -- Resolve the package names in the use clause, and make all the visible
2526 -- entities defined in the package potentially use-visible. If the package
2527 -- is already in use from a previous use clause, its visible entities are
2528 -- already use-visible. In that case, mark the occurrence as a redundant
2529 -- use. If the package is an open scope, i.e. if the use clause occurs
2530 -- within the package itself, ignore it.
2532 procedure Analyze_Use_Package (N : Node_Id) is
2533 Pack_Name : Node_Id;
2536 -- Start of processing for Analyze_Use_Package
2539 Set_Hidden_By_Use_Clause (N, No_Elist);
2541 -- Use clause is not allowed in a spec of a predefined package
2542 -- declaration except that packages whose file name starts a-n are OK
2543 -- (these are children of Ada.Numerics, and such packages are never
2544 -- loaded by Rtsfind).
2546 if Is_Predefined_File_Name (Unit_File_Name (Current_Sem_Unit))
2547 and then Name_Buffer (1 .. 3) /= "a-n"
2549 Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Declaration
2551 Error_Msg_N ("use clause not allowed in predefined spec", N);
2554 -- Chain clause to list of use clauses in current scope
2556 if Nkind (Parent (N)) /= N_Compilation_Unit then
2557 Chain_Use_Clause (N);
2560 -- Loop through package names to identify referenced packages
2562 Pack_Name := First (Names (N));
2563 while Present (Pack_Name) loop
2564 Analyze (Pack_Name);
2566 if Nkind (Parent (N)) = N_Compilation_Unit
2567 and then Nkind (Pack_Name) = N_Expanded_Name
2573 Pref := Prefix (Pack_Name);
2574 while Nkind (Pref) = N_Expanded_Name loop
2575 Pref := Prefix (Pref);
2578 if Entity (Pref) = Standard_Standard then
2580 ("predefined package Standard cannot appear"
2581 & " in a context clause", Pref);
2589 -- Loop through package names to mark all entities as potentially
2592 Pack_Name := First (Names (N));
2593 while Present (Pack_Name) loop
2594 if Is_Entity_Name (Pack_Name) then
2595 Pack := Entity (Pack_Name);
2597 if Ekind (Pack) /= E_Package
2598 and then Etype (Pack) /= Any_Type
2600 if Ekind (Pack) = E_Generic_Package then
2601 Error_Msg_N -- CODEFIX
2602 ("a generic package is not allowed in a use clause",
2605 Error_Msg_N ("& is not a usable package", Pack_Name);
2609 if Nkind (Parent (N)) = N_Compilation_Unit then
2610 Check_In_Previous_With_Clause (N, Pack_Name);
2613 if Applicable_Use (Pack_Name) then
2614 Use_One_Package (Pack, N);
2618 -- Report error because name denotes something other than a package
2621 Error_Msg_N ("& is not a package", Pack_Name);
2626 end Analyze_Use_Package;
2628 ----------------------
2629 -- Analyze_Use_Type --
2630 ----------------------
2632 procedure Analyze_Use_Type (N : Node_Id) is
2637 Set_Hidden_By_Use_Clause (N, No_Elist);
2639 -- Chain clause to list of use clauses in current scope
2641 if Nkind (Parent (N)) /= N_Compilation_Unit then
2642 Chain_Use_Clause (N);
2645 Id := First (Subtype_Marks (N));
2646 while Present (Id) loop
2650 if E /= Any_Type then
2653 if Nkind (Parent (N)) = N_Compilation_Unit then
2654 if Nkind (Id) = N_Identifier then
2655 Error_Msg_N ("type is not directly visible", Id);
2657 elsif Is_Child_Unit (Scope (E))
2658 and then Scope (E) /= System_Aux_Id
2660 Check_In_Previous_With_Clause (N, Prefix (Id));
2665 -- If the use_type_clause appears in a compilation unit context,
2666 -- check whether it comes from a unit that may appear in a
2667 -- limited_with_clause, for a better error message.
2669 if Nkind (Parent (N)) = N_Compilation_Unit
2670 and then Nkind (Id) /= N_Identifier
2676 function Mentioned (Nam : Node_Id) return Boolean;
2677 -- Check whether the prefix of expanded name for the type
2678 -- appears in the prefix of some limited_with_clause.
2684 function Mentioned (Nam : Node_Id) return Boolean is
2686 return Nkind (Name (Item)) = N_Selected_Component
2688 Chars (Prefix (Name (Item))) = Chars (Nam);
2692 Pref := Prefix (Id);
2693 Item := First (Context_Items (Parent (N)));
2695 while Present (Item) and then Item /= N loop
2696 if Nkind (Item) = N_With_Clause
2697 and then Limited_Present (Item)
2698 and then Mentioned (Pref)
2701 (Get_Msg_Id, "premature usage of incomplete type");
2712 end Analyze_Use_Type;
2714 --------------------
2715 -- Applicable_Use --
2716 --------------------
2718 function Applicable_Use (Pack_Name : Node_Id) return Boolean is
2719 Pack : constant Entity_Id := Entity (Pack_Name);
2722 if In_Open_Scopes (Pack) then
2723 if Warn_On_Redundant_Constructs
2724 and then Pack = Current_Scope
2726 Error_Msg_NE -- CODEFIX
2727 ("& is already use-visible within itself?", Pack_Name, Pack);
2732 elsif In_Use (Pack) then
2733 Note_Redundant_Use (Pack_Name);
2736 elsif Present (Renamed_Object (Pack))
2737 and then In_Use (Renamed_Object (Pack))
2739 Note_Redundant_Use (Pack_Name);
2747 ------------------------
2748 -- Attribute_Renaming --
2749 ------------------------
2751 procedure Attribute_Renaming (N : Node_Id) is
2752 Loc : constant Source_Ptr := Sloc (N);
2753 Nam : constant Node_Id := Name (N);
2754 Spec : constant Node_Id := Specification (N);
2755 New_S : constant Entity_Id := Defining_Unit_Name (Spec);
2756 Aname : constant Name_Id := Attribute_Name (Nam);
2758 Form_Num : Nat := 0;
2759 Expr_List : List_Id := No_List;
2761 Attr_Node : Node_Id;
2762 Body_Node : Node_Id;
2763 Param_Spec : Node_Id;
2766 Generate_Definition (New_S);
2768 -- This procedure is called in the context of subprogram renaming, and
2769 -- thus the attribute must be one that is a subprogram. All of those
2770 -- have at least one formal parameter, with the singular exception of
2771 -- AST_Entry (which is a real oddity, it is odd that this can be renamed
2774 if not Is_Non_Empty_List (Parameter_Specifications (Spec)) then
2775 if Aname /= Name_AST_Entry then
2777 ("subprogram renaming an attribute must have formals", N);
2782 Param_Spec := First (Parameter_Specifications (Spec));
2783 while Present (Param_Spec) loop
2784 Form_Num := Form_Num + 1;
2786 if Nkind (Parameter_Type (Param_Spec)) /= N_Access_Definition then
2787 Find_Type (Parameter_Type (Param_Spec));
2789 -- The profile of the new entity denotes the base type (s) of
2790 -- the types given in the specification. For access parameters
2791 -- there are no subtypes involved.
2793 Rewrite (Parameter_Type (Param_Spec),
2795 (Base_Type (Entity (Parameter_Type (Param_Spec))), Loc));
2798 if No (Expr_List) then
2799 Expr_List := New_List;
2802 Append_To (Expr_List,
2803 Make_Identifier (Loc,
2804 Chars => Chars (Defining_Identifier (Param_Spec))));
2806 -- The expressions in the attribute reference are not freeze
2807 -- points. Neither is the attribute as a whole, see below.
2809 Set_Must_Not_Freeze (Last (Expr_List));
2814 -- Immediate error if too many formals. Other mismatches in number or
2815 -- types of parameters are detected when we analyze the body of the
2816 -- subprogram that we construct.
2818 if Form_Num > 2 then
2819 Error_Msg_N ("too many formals for attribute", N);
2821 -- Error if the attribute reference has expressions that look like
2822 -- formal parameters.
2824 elsif Present (Expressions (Nam)) then
2825 Error_Msg_N ("illegal expressions in attribute reference", Nam);
2828 Aname = Name_Compose or else
2829 Aname = Name_Exponent or else
2830 Aname = Name_Leading_Part or else
2831 Aname = Name_Pos or else
2832 Aname = Name_Round or else
2833 Aname = Name_Scaling or else
2836 if Nkind (N) = N_Subprogram_Renaming_Declaration
2837 and then Present (Corresponding_Formal_Spec (N))
2840 ("generic actual cannot be attribute involving universal type",
2844 ("attribute involving a universal type cannot be renamed",
2849 -- AST_Entry is an odd case. It doesn't really make much sense to allow
2850 -- it to be renamed, but that's the DEC rule, so we have to do it right.
2851 -- The point is that the AST_Entry call should be made now, and what the
2852 -- function will return is the returned value.
2854 -- Note that there is no Expr_List in this case anyway
2856 if Aname = Name_AST_Entry then
2858 Ent : constant Entity_Id := Make_Temporary (Loc, 'R', Nam);
2863 Make_Object_Declaration (Loc,
2864 Defining_Identifier => Ent,
2865 Object_Definition =>
2866 New_Occurrence_Of (RTE (RE_AST_Handler), Loc),
2868 Constant_Present => True);
2870 Set_Assignment_OK (Decl, True);
2871 Insert_Action (N, Decl);
2872 Attr_Node := Make_Identifier (Loc, Chars (Ent));
2875 -- For all other attributes, we rewrite the attribute node to have
2876 -- a list of expressions corresponding to the subprogram formals.
2877 -- A renaming declaration is not a freeze point, and the analysis of
2878 -- the attribute reference should not freeze the type of the prefix.
2882 Make_Attribute_Reference (Loc,
2883 Prefix => Prefix (Nam),
2884 Attribute_Name => Aname,
2885 Expressions => Expr_List);
2887 Set_Must_Not_Freeze (Attr_Node);
2888 Set_Must_Not_Freeze (Prefix (Nam));
2891 -- Case of renaming a function
2893 if Nkind (Spec) = N_Function_Specification then
2894 if Is_Procedure_Attribute_Name (Aname) then
2895 Error_Msg_N ("attribute can only be renamed as procedure", Nam);
2899 Find_Type (Result_Definition (Spec));
2900 Rewrite (Result_Definition (Spec),
2902 Base_Type (Entity (Result_Definition (Spec))), Loc));
2905 Make_Subprogram_Body (Loc,
2906 Specification => Spec,
2907 Declarations => New_List,
2908 Handled_Statement_Sequence =>
2909 Make_Handled_Sequence_Of_Statements (Loc,
2910 Statements => New_List (
2911 Make_Simple_Return_Statement (Loc,
2912 Expression => Attr_Node))));
2914 -- Case of renaming a procedure
2917 if not Is_Procedure_Attribute_Name (Aname) then
2918 Error_Msg_N ("attribute can only be renamed as function", Nam);
2923 Make_Subprogram_Body (Loc,
2924 Specification => Spec,
2925 Declarations => New_List,
2926 Handled_Statement_Sequence =>
2927 Make_Handled_Sequence_Of_Statements (Loc,
2928 Statements => New_List (Attr_Node)));
2931 -- In case of tagged types we add the body of the generated function to
2932 -- the freezing actions of the type (because in the general case such
2933 -- type is still not frozen). We exclude from this processing generic
2934 -- formal subprograms found in instantiations and AST_Entry renamings.
2936 if not Present (Corresponding_Formal_Spec (N))
2937 and then Etype (Nam) /= RTE (RE_AST_Handler)
2940 P : constant Entity_Id := Prefix (Nam);
2945 if Is_Tagged_Type (Etype (P)) then
2946 Ensure_Freeze_Node (Etype (P));
2947 Append_Freeze_Action (Etype (P), Body_Node);
2949 Rewrite (N, Body_Node);
2951 Set_Etype (New_S, Base_Type (Etype (New_S)));
2955 -- Generic formal subprograms or AST_Handler renaming
2958 Rewrite (N, Body_Node);
2960 Set_Etype (New_S, Base_Type (Etype (New_S)));
2963 if Is_Compilation_Unit (New_S) then
2965 ("a library unit can only rename another library unit", N);
2968 -- We suppress elaboration warnings for the resulting entity, since
2969 -- clearly they are not needed, and more particularly, in the case
2970 -- of a generic formal subprogram, the resulting entity can appear
2971 -- after the instantiation itself, and thus look like a bogus case
2972 -- of access before elaboration.
2974 Set_Suppress_Elaboration_Warnings (New_S);
2976 end Attribute_Renaming;
2978 ----------------------
2979 -- Chain_Use_Clause --
2980 ----------------------
2982 procedure Chain_Use_Clause (N : Node_Id) is
2984 Level : Int := Scope_Stack.Last;
2987 if not Is_Compilation_Unit (Current_Scope)
2988 or else not Is_Child_Unit (Current_Scope)
2990 null; -- Common case
2992 elsif Defining_Entity (Parent (N)) = Current_Scope then
2993 null; -- Common case for compilation unit
2996 -- If declaration appears in some other scope, it must be in some
2997 -- parent unit when compiling a child.
2999 Pack := Defining_Entity (Parent (N));
3000 if not In_Open_Scopes (Pack) then
3001 null; -- default as well
3004 -- Find entry for parent unit in scope stack
3006 while Scope_Stack.Table (Level).Entity /= Pack loop
3012 Set_Next_Use_Clause (N,
3013 Scope_Stack.Table (Level).First_Use_Clause);
3014 Scope_Stack.Table (Level).First_Use_Clause := N;
3015 end Chain_Use_Clause;
3017 ---------------------------
3018 -- Check_Frozen_Renaming --
3019 ---------------------------
3021 procedure Check_Frozen_Renaming (N : Node_Id; Subp : Entity_Id) is
3027 and then not Has_Completion (Subp)
3031 (Parent (Declaration_Node (Subp)), Defining_Entity (N));
3033 if Is_Entity_Name (Name (N)) then
3034 Old_S := Entity (Name (N));
3036 if not Is_Frozen (Old_S)
3037 and then Operating_Mode /= Check_Semantics
3039 Append_Freeze_Action (Old_S, B_Node);
3041 Insert_After (N, B_Node);
3045 if Is_Intrinsic_Subprogram (Old_S)
3046 and then not In_Instance
3049 ("subprogram used in renaming_as_body cannot be intrinsic",
3054 Insert_After (N, B_Node);
3058 end Check_Frozen_Renaming;
3060 -------------------------------
3061 -- Set_Entity_Or_Discriminal --
3062 -------------------------------
3064 procedure Set_Entity_Or_Discriminal (N : Node_Id; E : Entity_Id) is
3068 -- If the entity is not a discriminant, or else expansion is disabled,
3069 -- simply set the entity.
3071 if not In_Spec_Expression
3072 or else Ekind (E) /= E_Discriminant
3073 or else Inside_A_Generic
3075 Set_Entity_With_Style_Check (N, E);
3077 -- The replacement of a discriminant by the corresponding discriminal
3078 -- is not done for a task discriminant that appears in a default
3079 -- expression of an entry parameter. See Exp_Ch2.Expand_Discriminant
3080 -- for details on their handling.
3082 elsif Is_Concurrent_Type (Scope (E)) then
3086 and then not Nkind_In (P, N_Parameter_Specification,
3087 N_Component_Declaration)
3093 and then Nkind (P) = N_Parameter_Specification
3098 Set_Entity (N, Discriminal (E));
3101 -- Otherwise, this is a discriminant in a context in which
3102 -- it is a reference to the corresponding parameter of the
3103 -- init proc for the enclosing type.
3106 Set_Entity (N, Discriminal (E));
3108 end Set_Entity_Or_Discriminal;
3110 -----------------------------------
3111 -- Check_In_Previous_With_Clause --
3112 -----------------------------------
3114 procedure Check_In_Previous_With_Clause
3118 Pack : constant Entity_Id := Entity (Original_Node (Nam));
3123 Item := First (Context_Items (Parent (N)));
3125 while Present (Item)
3128 if Nkind (Item) = N_With_Clause
3130 -- Protect the frontend against previous critical errors
3132 and then Nkind (Name (Item)) /= N_Selected_Component
3133 and then Entity (Name (Item)) = Pack
3137 -- Find root library unit in with_clause
3139 while Nkind (Par) = N_Expanded_Name loop
3140 Par := Prefix (Par);
3143 if Is_Child_Unit (Entity (Original_Node (Par))) then
3144 Error_Msg_NE ("& is not directly visible", Par, Entity (Par));
3153 -- On exit, package is not mentioned in a previous with_clause.
3154 -- Check if its prefix is.
3156 if Nkind (Nam) = N_Expanded_Name then
3157 Check_In_Previous_With_Clause (N, Prefix (Nam));
3159 elsif Pack /= Any_Id then
3160 Error_Msg_NE ("& is not visible", Nam, Pack);
3162 end Check_In_Previous_With_Clause;
3164 ---------------------------------
3165 -- Check_Library_Unit_Renaming --
3166 ---------------------------------
3168 procedure Check_Library_Unit_Renaming (N : Node_Id; Old_E : Entity_Id) is
3172 if Nkind (Parent (N)) /= N_Compilation_Unit then
3175 -- Check for library unit. Note that we used to check for the scope
3176 -- being Standard here, but that was wrong for Standard itself.
3178 elsif not Is_Compilation_Unit (Old_E)
3179 and then not Is_Child_Unit (Old_E)
3181 Error_Msg_N ("renamed unit must be a library unit", Name (N));
3183 -- Entities defined in Standard (operators and boolean literals) cannot
3184 -- be renamed as library units.
3186 elsif Scope (Old_E) = Standard_Standard
3187 and then Sloc (Old_E) = Standard_Location
3189 Error_Msg_N ("renamed unit must be a library unit", Name (N));
3191 elsif Present (Parent_Spec (N))
3192 and then Nkind (Unit (Parent_Spec (N))) = N_Generic_Package_Declaration
3193 and then not Is_Child_Unit (Old_E)
3196 ("renamed unit must be a child unit of generic parent", Name (N));
3198 elsif Nkind (N) in N_Generic_Renaming_Declaration
3199 and then Nkind (Name (N)) = N_Expanded_Name
3200 and then Is_Generic_Instance (Entity (Prefix (Name (N))))
3201 and then Is_Generic_Unit (Old_E)
3204 ("renamed generic unit must be a library unit", Name (N));
3206 elsif Is_Package_Or_Generic_Package (Old_E) then
3208 -- Inherit categorization flags
3210 New_E := Defining_Entity (N);
3211 Set_Is_Pure (New_E, Is_Pure (Old_E));
3212 Set_Is_Preelaborated (New_E, Is_Preelaborated (Old_E));
3213 Set_Is_Remote_Call_Interface (New_E,
3214 Is_Remote_Call_Interface (Old_E));
3215 Set_Is_Remote_Types (New_E, Is_Remote_Types (Old_E));
3216 Set_Is_Shared_Passive (New_E, Is_Shared_Passive (Old_E));
3218 end Check_Library_Unit_Renaming;
3224 procedure End_Scope is
3230 Id := First_Entity (Current_Scope);
3231 while Present (Id) loop
3232 -- An entity in the current scope is not necessarily the first one
3233 -- on its homonym chain. Find its predecessor if any,
3234 -- If it is an internal entity, it will not be in the visibility
3235 -- chain altogether, and there is nothing to unchain.
3237 if Id /= Current_Entity (Id) then
3238 Prev := Current_Entity (Id);
3239 while Present (Prev)
3240 and then Present (Homonym (Prev))
3241 and then Homonym (Prev) /= Id
3243 Prev := Homonym (Prev);
3246 -- Skip to end of loop if Id is not in the visibility chain
3248 if No (Prev) or else Homonym (Prev) /= Id then
3256 Set_Is_Immediately_Visible (Id, False);
3258 Outer := Homonym (Id);
3259 while Present (Outer) and then Scope (Outer) = Current_Scope loop
3260 Outer := Homonym (Outer);
3263 -- Reset homonym link of other entities, but do not modify link
3264 -- between entities in current scope, so that the back-end can have
3265 -- a proper count of local overloadings.
3268 Set_Name_Entity_Id (Chars (Id), Outer);
3270 elsif Scope (Prev) /= Scope (Id) then
3271 Set_Homonym (Prev, Outer);
3278 -- If the scope generated freeze actions, place them before the
3279 -- current declaration and analyze them. Type declarations and
3280 -- the bodies of initialization procedures can generate such nodes.
3281 -- We follow the parent chain until we reach a list node, which is
3282 -- the enclosing list of declarations. If the list appears within
3283 -- a protected definition, move freeze nodes outside the protected
3287 (Scope_Stack.Table (Scope_Stack.Last).Pending_Freeze_Actions)
3291 L : constant List_Id := Scope_Stack.Table
3292 (Scope_Stack.Last).Pending_Freeze_Actions;
3295 if Is_Itype (Current_Scope) then
3296 Decl := Associated_Node_For_Itype (Current_Scope);
3298 Decl := Parent (Current_Scope);
3303 while not (Is_List_Member (Decl))
3304 or else Nkind_In (Parent (Decl), N_Protected_Definition,
3307 Decl := Parent (Decl);
3310 Insert_List_Before_And_Analyze (Decl, L);
3319 ---------------------
3320 -- End_Use_Clauses --
3321 ---------------------
3323 procedure End_Use_Clauses (Clause : Node_Id) is
3327 -- Remove Use_Type clauses first, because they affect the
3328 -- visibility of operators in subsequent used packages.
3331 while Present (U) loop
3332 if Nkind (U) = N_Use_Type_Clause then
3336 Next_Use_Clause (U);
3340 while Present (U) loop
3341 if Nkind (U) = N_Use_Package_Clause then
3342 End_Use_Package (U);
3345 Next_Use_Clause (U);
3347 end End_Use_Clauses;
3349 ---------------------
3350 -- End_Use_Package --
3351 ---------------------
3353 procedure End_Use_Package (N : Node_Id) is
3354 Pack_Name : Node_Id;
3359 function Is_Primitive_Operator
3361 F : Entity_Id) return Boolean;
3362 -- Check whether Op is a primitive operator of a use-visible type
3364 ---------------------------
3365 -- Is_Primitive_Operator --
3366 ---------------------------
3368 function Is_Primitive_Operator
3370 F : Entity_Id) return Boolean
3372 T : constant Entity_Id := Etype (F);
3375 and then Scope (T) = Scope (Op);
3376 end Is_Primitive_Operator;
3378 -- Start of processing for End_Use_Package
3381 Pack_Name := First (Names (N));
3382 while Present (Pack_Name) loop
3384 -- Test that Pack_Name actually denotes a package before processing
3386 if Is_Entity_Name (Pack_Name)
3387 and then Ekind (Entity (Pack_Name)) = E_Package
3389 Pack := Entity (Pack_Name);
3391 if In_Open_Scopes (Pack) then
3394 elsif not Redundant_Use (Pack_Name) then
3395 Set_In_Use (Pack, False);
3396 Set_Current_Use_Clause (Pack, Empty);
3398 Id := First_Entity (Pack);
3399 while Present (Id) loop
3401 -- Preserve use-visibility of operators that are primitive
3402 -- operators of a type that is use-visible through an active
3405 if Nkind (Id) = N_Defining_Operator_Symbol
3407 (Is_Primitive_Operator (Id, First_Formal (Id))
3409 (Present (Next_Formal (First_Formal (Id)))
3411 Is_Primitive_Operator
3412 (Id, Next_Formal (First_Formal (Id)))))
3417 Set_Is_Potentially_Use_Visible (Id, False);
3420 if Is_Private_Type (Id)
3421 and then Present (Full_View (Id))
3423 Set_Is_Potentially_Use_Visible (Full_View (Id), False);
3429 if Present (Renamed_Object (Pack)) then
3430 Set_In_Use (Renamed_Object (Pack), False);
3431 Set_Current_Use_Clause (Renamed_Object (Pack), Empty);
3434 if Chars (Pack) = Name_System
3435 and then Scope (Pack) = Standard_Standard
3436 and then Present_System_Aux
3438 Id := First_Entity (System_Aux_Id);
3439 while Present (Id) loop
3440 Set_Is_Potentially_Use_Visible (Id, False);
3442 if Is_Private_Type (Id)
3443 and then Present (Full_View (Id))
3445 Set_Is_Potentially_Use_Visible (Full_View (Id), False);
3451 Set_In_Use (System_Aux_Id, False);
3455 Set_Redundant_Use (Pack_Name, False);
3462 if Present (Hidden_By_Use_Clause (N)) then
3463 Elmt := First_Elmt (Hidden_By_Use_Clause (N));
3464 while Present (Elmt) loop
3466 E : constant Entity_Id := Node (Elmt);
3469 -- Reset either Use_Visibility or Direct_Visibility, depending
3470 -- on how the entity was hidden by the use clause.
3472 if In_Use (Scope (E))
3473 and then Used_As_Generic_Actual (Scope (E))
3475 Set_Is_Potentially_Use_Visible (Node (Elmt));
3477 Set_Is_Immediately_Visible (Node (Elmt));
3484 Set_Hidden_By_Use_Clause (N, No_Elist);
3486 end End_Use_Package;
3492 procedure End_Use_Type (N : Node_Id) is
3499 function May_Be_Used_Primitive_Of (T : Entity_Id) return Boolean;
3500 -- An operator may be primitive in several types, if they are declared
3501 -- in the same scope as the operator. To determine the use-visiblity of
3502 -- the operator in such cases we must examine all types in the profile.
3504 ------------------------------
3505 -- May_Be_Used_Primitive_Of --
3506 ------------------------------
3508 function May_Be_Used_Primitive_Of (T : Entity_Id) return Boolean is
3510 return Scope (Op) = Scope (T)
3511 and then (In_Use (T) or else Is_Potentially_Use_Visible (T));
3512 end May_Be_Used_Primitive_Of;
3514 -- Start of processing for End_Use_Type
3517 Id := First (Subtype_Marks (N));
3518 while Present (Id) loop
3520 -- A call to Rtsfind may occur while analyzing a use_type clause,
3521 -- in which case the type marks are not resolved yet, and there is
3522 -- nothing to remove.
3524 if not Is_Entity_Name (Id) or else No (Entity (Id)) then
3530 if T = Any_Type or else From_With_Type (T) then
3533 -- Note that the use_type clause may mention a subtype of the type
3534 -- whose primitive operations have been made visible. Here as
3535 -- elsewhere, it is the base type that matters for visibility.
3537 elsif In_Open_Scopes (Scope (Base_Type (T))) then
3540 elsif not Redundant_Use (Id) then
3541 Set_In_Use (T, False);
3542 Set_In_Use (Base_Type (T), False);
3543 Set_Current_Use_Clause (T, Empty);
3544 Set_Current_Use_Clause (Base_Type (T), Empty);
3545 Op_List := Collect_Primitive_Operations (T);
3547 Elmt := First_Elmt (Op_List);
3548 while Present (Elmt) loop
3551 if Nkind (Op) = N_Defining_Operator_Symbol then
3553 T_First : constant Entity_Id :=
3554 Base_Type (Etype (First_Formal (Op)));
3555 T_Res : constant Entity_Id := Base_Type (Etype (Op));
3559 if Present (Next_Formal (First_Formal (Op))) then
3561 Base_Type (Etype (Next_Formal (First_Formal (Op))));
3566 if not May_Be_Used_Primitive_Of (T_First)
3567 and then not May_Be_Used_Primitive_Of (T_Next)
3568 and then not May_Be_Used_Primitive_Of (T_Res)
3570 Set_Is_Potentially_Use_Visible (Op, False);
3584 ----------------------
3585 -- Find_Direct_Name --
3586 ----------------------
3588 procedure Find_Direct_Name (N : Node_Id) is
3593 Inst : Entity_Id := Empty;
3594 -- Enclosing instance, if any
3596 Homonyms : Entity_Id;
3597 -- Saves start of homonym chain
3599 Nvis_Entity : Boolean;
3600 -- Set True to indicate that there is at least one entity on the homonym
3601 -- chain which, while not visible, is visible enough from the user point
3602 -- of view to warrant an error message of "not visible" rather than
3605 Nvis_Is_Private_Subprg : Boolean := False;
3606 -- Ada 2005 (AI-262): Set True to indicate that a form of Beaujolais
3607 -- effect concerning library subprograms has been detected. Used to
3608 -- generate the precise error message.
3610 function From_Actual_Package (E : Entity_Id) return Boolean;
3611 -- Returns true if the entity is declared in a package that is
3612 -- an actual for a formal package of the current instance. Such an
3613 -- entity requires special handling because it may be use-visible
3614 -- but hides directly visible entities defined outside the instance.
3616 function Is_Actual_Parameter return Boolean;
3617 -- This function checks if the node N is an identifier that is an actual
3618 -- parameter of a procedure call. If so it returns True, otherwise it
3619 -- return False. The reason for this check is that at this stage we do
3620 -- not know what procedure is being called if the procedure might be
3621 -- overloaded, so it is premature to go setting referenced flags or
3622 -- making calls to Generate_Reference. We will wait till Resolve_Actuals
3623 -- for that processing
3625 function Known_But_Invisible (E : Entity_Id) return Boolean;
3626 -- This function determines whether the entity E (which is not
3627 -- visible) can reasonably be considered to be known to the writer
3628 -- of the reference. This is a heuristic test, used only for the
3629 -- purposes of figuring out whether we prefer to complain that an
3630 -- entity is undefined or invisible (and identify the declaration
3631 -- of the invisible entity in the latter case). The point here is
3632 -- that we don't want to complain that something is invisible and
3633 -- then point to something entirely mysterious to the writer.
3635 procedure Nvis_Messages;
3636 -- Called if there are no visible entries for N, but there is at least
3637 -- one non-directly visible, or hidden declaration. This procedure
3638 -- outputs an appropriate set of error messages.
3640 procedure Undefined (Nvis : Boolean);
3641 -- This function is called if the current node has no corresponding
3642 -- visible entity or entities. The value set in Msg indicates whether
3643 -- an error message was generated (multiple error messages for the
3644 -- same variable are generally suppressed, see body for details).
3645 -- Msg is True if an error message was generated, False if not. This
3646 -- value is used by the caller to determine whether or not to output
3647 -- additional messages where appropriate. The parameter is set False
3648 -- to get the message "X is undefined", and True to get the message
3649 -- "X is not visible".
3651 -------------------------
3652 -- From_Actual_Package --
3653 -------------------------
3655 function From_Actual_Package (E : Entity_Id) return Boolean is
3656 Scop : constant Entity_Id := Scope (E);
3660 if not In_Instance then
3663 Inst := Current_Scope;
3664 while Present (Inst)
3665 and then Ekind (Inst) /= E_Package
3666 and then not Is_Generic_Instance (Inst)
3668 Inst := Scope (Inst);
3675 Act := First_Entity (Inst);
3676 while Present (Act) loop
3677 if Ekind (Act) = E_Package then
3679 -- Check for end of actuals list
3681 if Renamed_Object (Act) = Inst then
3684 elsif Present (Associated_Formal_Package (Act))
3685 and then Renamed_Object (Act) = Scop
3687 -- Entity comes from (instance of) formal package
3702 end From_Actual_Package;
3704 -------------------------
3705 -- Is_Actual_Parameter --
3706 -------------------------
3708 function Is_Actual_Parameter return Boolean is
3711 Nkind (N) = N_Identifier
3713 (Nkind (Parent (N)) = N_Procedure_Call_Statement
3715 (Nkind (Parent (N)) = N_Parameter_Association
3716 and then N = Explicit_Actual_Parameter (Parent (N))
3717 and then Nkind (Parent (Parent (N))) =
3718 N_Procedure_Call_Statement));
3719 end Is_Actual_Parameter;
3721 -------------------------
3722 -- Known_But_Invisible --
3723 -------------------------
3725 function Known_But_Invisible (E : Entity_Id) return Boolean is
3726 Fname : File_Name_Type;
3729 -- Entities in Standard are always considered to be known
3731 if Sloc (E) <= Standard_Location then
3734 -- An entity that does not come from source is always considered
3735 -- to be unknown, since it is an artifact of code expansion.
3737 elsif not Comes_From_Source (E) then
3740 -- In gnat internal mode, we consider all entities known
3742 elsif GNAT_Mode then
3746 -- Here we have an entity that is not from package Standard, and
3747 -- which comes from Source. See if it comes from an internal file.
3749 Fname := Unit_File_Name (Get_Source_Unit (E));
3751 -- Case of from internal file
3753 if Is_Internal_File_Name (Fname) then
3755 -- Private part entities in internal files are never considered
3756 -- to be known to the writer of normal application code.
3758 if Is_Hidden (E) then
3762 -- Entities from System packages other than System and
3763 -- System.Storage_Elements are not considered to be known.
3764 -- System.Auxxxx files are also considered known to the user.
3766 -- Should refine this at some point to generally distinguish
3767 -- between known and unknown internal files ???
3769 Get_Name_String (Fname);
3774 Name_Buffer (1 .. 2) /= "s-"
3776 Name_Buffer (3 .. 8) = "stoele"
3778 Name_Buffer (3 .. 5) = "aux";
3780 -- If not an internal file, then entity is definitely known,
3781 -- even if it is in a private part (the message generated will
3782 -- note that it is in a private part)
3787 end Known_But_Invisible;
3793 procedure Nvis_Messages is
3794 Comp_Unit : Node_Id;
3796 Found : Boolean := False;
3797 Hidden : Boolean := False;
3801 -- Ada 2005 (AI-262): Generate a precise error concerning the
3802 -- Beaujolais effect that was previously detected
3804 if Nvis_Is_Private_Subprg then
3806 pragma Assert (Nkind (E2) = N_Defining_Identifier
3807 and then Ekind (E2) = E_Function
3808 and then Scope (E2) = Standard_Standard
3809 and then Has_Private_With (E2));
3811 -- Find the sloc corresponding to the private with'ed unit
3813 Comp_Unit := Cunit (Current_Sem_Unit);
3814 Error_Msg_Sloc := No_Location;
3816 Item := First (Context_Items (Comp_Unit));
3817 while Present (Item) loop
3818 if Nkind (Item) = N_With_Clause
3819 and then Private_Present (Item)
3820 and then Entity (Name (Item)) = E2
3822 Error_Msg_Sloc := Sloc (Item);
3829 pragma Assert (Error_Msg_Sloc /= No_Location);
3831 Error_Msg_N ("(Ada 2005): hidden by private with clause #", N);
3835 Undefined (Nvis => True);
3839 -- First loop does hidden declarations
3842 while Present (Ent) loop
3843 if Is_Potentially_Use_Visible (Ent) then
3845 Error_Msg_N -- CODEFIX
3846 ("multiple use clauses cause hiding!", N);
3850 Error_Msg_Sloc := Sloc (Ent);
3851 Error_Msg_N -- CODEFIX
3852 ("hidden declaration#!", N);
3855 Ent := Homonym (Ent);
3858 -- If we found hidden declarations, then that's enough, don't
3859 -- bother looking for non-visible declarations as well.
3865 -- Second loop does non-directly visible declarations
3868 while Present (Ent) loop
3869 if not Is_Potentially_Use_Visible (Ent) then
3871 -- Do not bother the user with unknown entities
3873 if not Known_But_Invisible (Ent) then
3877 Error_Msg_Sloc := Sloc (Ent);
3879 -- Output message noting that there is a non-visible
3880 -- declaration, distinguishing the private part case.
3882 if Is_Hidden (Ent) then
3883 Error_Msg_N ("non-visible (private) declaration#!", N);
3885 -- If the entity is declared in a generic package, it
3886 -- cannot be visible, so there is no point in adding it
3887 -- to the list of candidates if another homograph from a
3888 -- non-generic package has been seen.
3890 elsif Ekind (Scope (Ent)) = E_Generic_Package
3896 Error_Msg_N -- CODEFIX
3897 ("non-visible declaration#!", N);
3899 if Ekind (Scope (Ent)) /= E_Generic_Package then
3903 if Is_Compilation_Unit (Ent)
3905 Nkind (Parent (Parent (N))) = N_Use_Package_Clause
3907 Error_Msg_Qual_Level := 99;
3908 Error_Msg_NE -- CODEFIX
3909 ("\\missing `WITH &;`", N, Ent);
3910 Error_Msg_Qual_Level := 0;
3913 if Ekind (Ent) = E_Discriminant
3914 and then Present (Corresponding_Discriminant (Ent))
3915 and then Scope (Corresponding_Discriminant (Ent)) =
3919 ("inherited discriminant not allowed here" &
3920 " (RM 3.8 (12), 3.8.1 (6))!", N);
3924 -- Set entity and its containing package as referenced. We
3925 -- can't be sure of this, but this seems a better choice
3926 -- to avoid unused entity messages.
3928 if Comes_From_Source (Ent) then
3929 Set_Referenced (Ent);
3930 Set_Referenced (Cunit_Entity (Get_Source_Unit (Ent)));
3935 Ent := Homonym (Ent);
3944 procedure Undefined (Nvis : Boolean) is
3945 Emsg : Error_Msg_Id;
3948 -- We should never find an undefined internal name. If we do, then
3949 -- see if we have previous errors. If so, ignore on the grounds that
3950 -- it is probably a cascaded message (e.g. a block label from a badly
3951 -- formed block). If no previous errors, then we have a real internal
3952 -- error of some kind so raise an exception.
3954 if Is_Internal_Name (Chars (N)) then
3955 if Total_Errors_Detected /= 0 then
3958 raise Program_Error;
3962 -- A very specialized error check, if the undefined variable is
3963 -- a case tag, and the case type is an enumeration type, check
3964 -- for a possible misspelling, and if so, modify the identifier
3966 -- Named aggregate should also be handled similarly ???
3968 if Nkind (N) = N_Identifier
3969 and then Nkind (Parent (N)) = N_Case_Statement_Alternative
3972 Case_Stm : constant Node_Id := Parent (Parent (N));
3973 Case_Typ : constant Entity_Id := Etype (Expression (Case_Stm));
3978 if Is_Enumeration_Type (Case_Typ)
3979 and then not Is_Standard_Character_Type (Case_Typ)
3981 Lit := First_Literal (Case_Typ);
3982 Get_Name_String (Chars (Lit));
3984 if Chars (Lit) /= Chars (N)
3985 and then Is_Bad_Spelling_Of (Chars (N), Chars (Lit)) then
3986 Error_Msg_Node_2 := Lit;
3987 Error_Msg_N -- CODEFIX
3988 ("& is undefined, assume misspelling of &", N);
3989 Rewrite (N, New_Occurrence_Of (Lit, Sloc (N)));
3993 Lit := Next_Literal (Lit);
3998 -- Normal processing
4000 Set_Entity (N, Any_Id);
4001 Set_Etype (N, Any_Type);
4003 -- We use the table Urefs to keep track of entities for which we
4004 -- have issued errors for undefined references. Multiple errors
4005 -- for a single name are normally suppressed, however we modify
4006 -- the error message to alert the programmer to this effect.
4008 for J in Urefs.First .. Urefs.Last loop
4009 if Chars (N) = Chars (Urefs.Table (J).Node) then
4010 if Urefs.Table (J).Err /= No_Error_Msg
4011 and then Sloc (N) /= Urefs.Table (J).Loc
4013 Error_Msg_Node_1 := Urefs.Table (J).Node;
4015 if Urefs.Table (J).Nvis then
4016 Change_Error_Text (Urefs.Table (J).Err,
4017 "& is not visible (more references follow)");
4019 Change_Error_Text (Urefs.Table (J).Err,
4020 "& is undefined (more references follow)");
4023 Urefs.Table (J).Err := No_Error_Msg;
4026 -- Although we will set Msg False, and thus suppress the
4027 -- message, we also set Error_Posted True, to avoid any
4028 -- cascaded messages resulting from the undefined reference.
4031 Set_Error_Posted (N, True);
4036 -- If entry not found, this is first undefined occurrence
4039 Error_Msg_N ("& is not visible!", N);
4043 Error_Msg_N ("& is undefined!", N);
4046 -- A very bizarre special check, if the undefined identifier
4047 -- is put or put_line, then add a special error message (since
4048 -- this is a very common error for beginners to make).
4050 if Chars (N) = Name_Put or else Chars (N) = Name_Put_Line then
4051 Error_Msg_N -- CODEFIX
4052 ("\\possible missing `WITH Ada.Text_'I'O; " &
4053 "USE Ada.Text_'I'O`!", N);
4055 -- Another special check if N is the prefix of a selected
4056 -- component which is a known unit, add message complaining
4057 -- about missing with for this unit.
4059 elsif Nkind (Parent (N)) = N_Selected_Component
4060 and then N = Prefix (Parent (N))
4061 and then Is_Known_Unit (Parent (N))
4063 Error_Msg_Node_2 := Selector_Name (Parent (N));
4064 Error_Msg_N -- CODEFIX
4065 ("\\missing `WITH &.&;`", Prefix (Parent (N)));
4068 -- Now check for possible misspellings
4072 Ematch : Entity_Id := Empty;
4074 Last_Name_Id : constant Name_Id :=
4075 Name_Id (Nat (First_Name_Id) +
4076 Name_Entries_Count - 1);
4079 for Nam in First_Name_Id .. Last_Name_Id loop
4080 E := Get_Name_Entity_Id (Nam);
4083 and then (Is_Immediately_Visible (E)
4085 Is_Potentially_Use_Visible (E))
4087 if Is_Bad_Spelling_Of (Chars (N), Nam) then
4094 if Present (Ematch) then
4095 Error_Msg_NE -- CODEFIX
4096 ("\possible misspelling of&", N, Ematch);
4101 -- Make entry in undefined references table unless the full errors
4102 -- switch is set, in which case by refraining from generating the
4103 -- table entry, we guarantee that we get an error message for every
4104 -- undefined reference.
4106 if not All_Errors_Mode then
4117 -- Start of processing for Find_Direct_Name
4120 -- If the entity pointer is already set, this is an internal node, or
4121 -- a node that is analyzed more than once, after a tree modification.
4122 -- In such a case there is no resolution to perform, just set the type.
4124 if Present (Entity (N)) then
4125 if Is_Type (Entity (N)) then
4126 Set_Etype (N, Entity (N));
4130 Entyp : constant Entity_Id := Etype (Entity (N));
4133 -- One special case here. If the Etype field is already set,
4134 -- and references the packed array type corresponding to the
4135 -- etype of the referenced entity, then leave it alone. This
4136 -- happens for trees generated from Exp_Pakd, where expressions
4137 -- can be deliberately "mis-typed" to the packed array type.
4139 if Is_Array_Type (Entyp)
4140 and then Is_Packed (Entyp)
4141 and then Present (Etype (N))
4142 and then Etype (N) = Packed_Array_Type (Entyp)
4146 -- If not that special case, then just reset the Etype
4149 Set_Etype (N, Etype (Entity (N)));
4157 -- Here if Entity pointer was not set, we need full visibility analysis
4158 -- First we generate debugging output if the debug E flag is set.
4160 if Debug_Flag_E then
4161 Write_Str ("Looking for ");
4162 Write_Name (Chars (N));
4166 Homonyms := Current_Entity (N);
4167 Nvis_Entity := False;
4170 while Present (E) loop
4172 -- If entity is immediately visible or potentially use visible, then
4173 -- process the entity and we are done.
4175 if Is_Immediately_Visible (E) then
4176 goto Immediately_Visible_Entity;
4178 elsif Is_Potentially_Use_Visible (E) then
4179 goto Potentially_Use_Visible_Entity;
4181 -- Note if a known but invisible entity encountered
4183 elsif Known_But_Invisible (E) then
4184 Nvis_Entity := True;
4187 -- Move to next entity in chain and continue search
4192 -- If no entries on homonym chain that were potentially visible,
4193 -- and no entities reasonably considered as non-visible, then
4194 -- we have a plain undefined reference, with no additional
4195 -- explanation required!
4197 if not Nvis_Entity then
4198 Undefined (Nvis => False);
4200 -- Otherwise there is at least one entry on the homonym chain that
4201 -- is reasonably considered as being known and non-visible.
4209 -- Processing for a potentially use visible entry found. We must search
4210 -- the rest of the homonym chain for two reasons. First, if there is a
4211 -- directly visible entry, then none of the potentially use-visible
4212 -- entities are directly visible (RM 8.4(10)). Second, we need to check
4213 -- for the case of multiple potentially use-visible entries hiding one
4214 -- another and as a result being non-directly visible (RM 8.4(11)).
4216 <<Potentially_Use_Visible_Entity>> declare
4217 Only_One_Visible : Boolean := True;
4218 All_Overloadable : Boolean := Is_Overloadable (E);
4222 while Present (E2) loop
4223 if Is_Immediately_Visible (E2) then
4225 -- If the use-visible entity comes from the actual for a
4226 -- formal package, it hides a directly visible entity from
4227 -- outside the instance.
4229 if From_Actual_Package (E)
4230 and then Scope_Depth (E2) < Scope_Depth (Inst)
4235 goto Immediately_Visible_Entity;
4238 elsif Is_Potentially_Use_Visible (E2) then
4239 Only_One_Visible := False;
4240 All_Overloadable := All_Overloadable and Is_Overloadable (E2);
4242 -- Ada 2005 (AI-262): Protect against a form of Beaujolais effect
4243 -- that can occur in private_with clauses. Example:
4246 -- private with B; package A is
4247 -- package C is function B return Integer;
4249 -- V1 : Integer := B;
4250 -- private function B return Integer;
4251 -- V2 : Integer := B;
4254 -- V1 resolves to A.B, but V2 resolves to library unit B
4256 elsif Ekind (E2) = E_Function
4257 and then Scope (E2) = Standard_Standard
4258 and then Has_Private_With (E2)
4260 Only_One_Visible := False;
4261 All_Overloadable := False;
4262 Nvis_Is_Private_Subprg := True;
4269 -- On falling through this loop, we have checked that there are no
4270 -- immediately visible entities. Only_One_Visible is set if exactly
4271 -- one potentially use visible entity exists. All_Overloadable is
4272 -- set if all the potentially use visible entities are overloadable.
4273 -- The condition for legality is that either there is one potentially
4274 -- use visible entity, or if there is more than one, then all of them
4275 -- are overloadable.
4277 if Only_One_Visible or All_Overloadable then
4280 -- If there is more than one potentially use-visible entity and at
4281 -- least one of them non-overloadable, we have an error (RM 8.4(11).
4282 -- Note that E points to the first such entity on the homonym list.
4283 -- Special case: if one of the entities is declared in an actual
4284 -- package, it was visible in the generic, and takes precedence over
4285 -- other entities that are potentially use-visible. Same if it is
4286 -- declared in a local instantiation of the current instance.
4291 -- Find current instance
4293 Inst := Current_Scope;
4294 while Present (Inst)
4295 and then Inst /= Standard_Standard
4297 if Is_Generic_Instance (Inst) then
4301 Inst := Scope (Inst);
4305 while Present (E2) loop
4306 if From_Actual_Package (E2)
4308 (Is_Generic_Instance (Scope (E2))
4309 and then Scope_Depth (Scope (E2)) > Scope_Depth (Inst))
4322 Is_Predefined_File_Name (Unit_File_Name (Current_Sem_Unit))
4324 -- A use-clause in the body of a system file creates conflict
4325 -- with some entity in a user scope, while rtsfind is active.
4326 -- Keep only the entity coming from another predefined unit.
4329 while Present (E2) loop
4330 if Is_Predefined_File_Name
4331 (Unit_File_Name (Get_Source_Unit (Sloc (E2))))
4340 -- Entity must exist because predefined unit is correct
4342 raise Program_Error;
4351 -- Come here with E set to the first immediately visible entity on
4352 -- the homonym chain. This is the one we want unless there is another
4353 -- immediately visible entity further on in the chain for an inner
4354 -- scope (RM 8.3(8)).
4356 <<Immediately_Visible_Entity>> declare
4361 -- Find scope level of initial entity. When compiling through
4362 -- Rtsfind, the previous context is not completely invisible, and
4363 -- an outer entity may appear on the chain, whose scope is below
4364 -- the entry for Standard that delimits the current scope stack.
4365 -- Indicate that the level for this spurious entry is outside of
4366 -- the current scope stack.
4368 Level := Scope_Stack.Last;
4370 Scop := Scope_Stack.Table (Level).Entity;
4371 exit when Scop = Scope (E);
4373 exit when Scop = Standard_Standard;
4376 -- Now search remainder of homonym chain for more inner entry
4377 -- If the entity is Standard itself, it has no scope, and we
4378 -- compare it with the stack entry directly.
4381 while Present (E2) loop
4382 if Is_Immediately_Visible (E2) then
4384 -- If a generic package contains a local declaration that
4385 -- has the same name as the generic, there may be a visibility
4386 -- conflict in an instance, where the local declaration must
4387 -- also hide the name of the corresponding package renaming.
4388 -- We check explicitly for a package declared by a renaming,
4389 -- whose renamed entity is an instance that is on the scope
4390 -- stack, and that contains a homonym in the same scope. Once
4391 -- we have found it, we know that the package renaming is not
4392 -- immediately visible, and that the identifier denotes the
4393 -- other entity (and its homonyms if overloaded).
4395 if Scope (E) = Scope (E2)
4396 and then Ekind (E) = E_Package
4397 and then Present (Renamed_Object (E))
4398 and then Is_Generic_Instance (Renamed_Object (E))
4399 and then In_Open_Scopes (Renamed_Object (E))
4400 and then Comes_From_Source (N)
4402 Set_Is_Immediately_Visible (E, False);
4406 for J in Level + 1 .. Scope_Stack.Last loop
4407 if Scope_Stack.Table (J).Entity = Scope (E2)
4408 or else Scope_Stack.Table (J).Entity = E2
4421 -- At the end of that loop, E is the innermost immediately
4422 -- visible entity, so we are all set.
4425 -- Come here with entity found, and stored in E
4429 -- Check violation of No_Wide_Characters restriction
4431 Check_Wide_Character_Restriction (E, N);
4433 -- When distribution features are available (Get_PCS_Name /=
4434 -- Name_No_DSA), a remote access-to-subprogram type is converted
4435 -- into a record type holding whatever information is needed to
4436 -- perform a remote call on an RCI subprogram. In that case we
4437 -- rewrite any occurrence of the RAS type into the equivalent record
4438 -- type here. 'Access attribute references and RAS dereferences are
4439 -- then implemented using specific TSSs. However when distribution is
4440 -- not available (case of Get_PCS_Name = Name_No_DSA), we bypass the
4441 -- generation of these TSSs, and we must keep the RAS type in its
4442 -- original access-to-subprogram form (since all calls through a
4443 -- value of such type will be local anyway in the absence of a PCS).
4445 if Comes_From_Source (N)
4446 and then Is_Remote_Access_To_Subprogram_Type (E)
4447 and then Expander_Active
4448 and then Get_PCS_Name /= Name_No_DSA
4451 New_Occurrence_Of (Equivalent_Type (E), Sloc (N)));
4455 -- Set the entity. Note that the reason we call Set_Entity for the
4456 -- overloadable case, as opposed to Set_Entity_With_Style_Check is
4457 -- that in the overloaded case, the initial call can set the wrong
4458 -- homonym. The call that sets the right homonym is in Sem_Res and
4459 -- that call does use Set_Entity_With_Style_Check, so we don't miss
4462 if Is_Overloadable (E) then
4465 Set_Entity_With_Style_Check (N, E);
4471 Set_Etype (N, Get_Full_View (Etype (E)));
4474 if Debug_Flag_E then
4475 Write_Str (" found ");
4476 Write_Entity_Info (E, " ");
4479 -- If the Ekind of the entity is Void, it means that all homonyms
4480 -- are hidden from all visibility (RM 8.3(5,14-20)). However, this
4481 -- test is skipped if the current scope is a record and the name is
4482 -- a pragma argument expression (case of Atomic and Volatile pragmas
4483 -- and possibly other similar pragmas added later, which are allowed
4484 -- to reference components in the current record).
4486 if Ekind (E) = E_Void
4488 (not Is_Record_Type (Current_Scope)
4489 or else Nkind (Parent (N)) /= N_Pragma_Argument_Association)
4491 Premature_Usage (N);
4493 -- If the entity is overloadable, collect all interpretations of the
4494 -- name for subsequent overload resolution. We optimize a bit here to
4495 -- do this only if we have an overloadable entity that is not on its
4496 -- own on the homonym chain.
4498 elsif Is_Overloadable (E)
4499 and then (Present (Homonym (E)) or else Current_Entity (N) /= E)
4501 Collect_Interps (N);
4503 -- If no homonyms were visible, the entity is unambiguous
4505 if not Is_Overloaded (N) then
4506 if not Is_Actual_Parameter then
4507 Generate_Reference (E, N);
4511 -- Case of non-overloadable entity, set the entity providing that
4512 -- we do not have the case of a discriminant reference within a
4513 -- default expression. Such references are replaced with the
4514 -- corresponding discriminal, which is the formal corresponding to
4515 -- to the discriminant in the initialization procedure.
4518 -- Entity is unambiguous, indicate that it is referenced here
4520 -- For a renaming of an object, always generate simple reference,
4521 -- we don't try to keep track of assignments in this case.
4523 if Is_Object (E) and then Present (Renamed_Object (E)) then
4524 Generate_Reference (E, N);
4526 -- If the renamed entity is a private protected component,
4527 -- reference the original component as well. This needs to be
4528 -- done because the private renamings are installed before any
4529 -- analysis has occurred. Reference to a private component will
4530 -- resolve to the renaming and the original component will be
4531 -- left unreferenced, hence the following.
4533 if Is_Prival (E) then
4534 Generate_Reference (Prival_Link (E), N);
4537 -- One odd case is that we do not want to set the Referenced flag
4538 -- if the entity is a label, and the identifier is the label in
4539 -- the source, since this is not a reference from the point of
4540 -- view of the user.
4542 elsif Nkind (Parent (N)) = N_Label then
4544 R : constant Boolean := Referenced (E);
4547 -- Generate reference unless this is an actual parameter
4548 -- (see comment below)
4550 if Is_Actual_Parameter then
4551 Generate_Reference (E, N);
4552 Set_Referenced (E, R);
4556 -- Normal case, not a label: generate reference
4558 -- ??? It is too early to generate a reference here even if
4559 -- the entity is unambiguous, because the tree is not
4560 -- sufficiently typed at this point for Generate_Reference to
4561 -- determine whether this reference modifies the denoted object
4562 -- (because implicit dereferences cannot be identified prior to
4563 -- full type resolution).
4565 -- The Is_Actual_Parameter routine takes care of one of these
4566 -- cases but there are others probably ???
4569 if not Is_Actual_Parameter then
4570 Generate_Reference (E, N);
4573 Check_Nested_Access (E);
4576 Set_Entity_Or_Discriminal (N, E);
4579 end Find_Direct_Name;
4581 ------------------------
4582 -- Find_Expanded_Name --
4583 ------------------------
4585 -- This routine searches the homonym chain of the entity until it finds
4586 -- an entity declared in the scope denoted by the prefix. If the entity
4587 -- is private, it may nevertheless be immediately visible, if we are in
4588 -- the scope of its declaration.
4590 procedure Find_Expanded_Name (N : Node_Id) is
4591 Selector : constant Node_Id := Selector_Name (N);
4592 Candidate : Entity_Id := Empty;
4598 P_Name := Entity (Prefix (N));
4601 -- If the prefix is a renamed package, look for the entity in the
4602 -- original package.
4604 if Ekind (P_Name) = E_Package
4605 and then Present (Renamed_Object (P_Name))
4607 P_Name := Renamed_Object (P_Name);
4609 -- Rewrite node with entity field pointing to renamed object
4611 Rewrite (Prefix (N), New_Copy (Prefix (N)));
4612 Set_Entity (Prefix (N), P_Name);
4614 -- If the prefix is an object of a concurrent type, look for
4615 -- the entity in the associated task or protected type.
4617 elsif Is_Concurrent_Type (Etype (P_Name)) then
4618 P_Name := Etype (P_Name);
4621 Id := Current_Entity (Selector);
4624 Is_New_Candidate : Boolean;
4627 while Present (Id) loop
4628 if Scope (Id) = P_Name then
4630 Is_New_Candidate := True;
4632 -- Ada 2005 (AI-217): Handle shadow entities associated with types
4633 -- declared in limited-withed nested packages. We don't need to
4634 -- handle E_Incomplete_Subtype entities because the entities in
4635 -- the limited view are always E_Incomplete_Type entities (see
4636 -- Build_Limited_Views). Regarding the expression used to evaluate
4637 -- the scope, it is important to note that the limited view also
4638 -- has shadow entities associated nested packages. For this reason
4639 -- the correct scope of the entity is the scope of the real entity
4640 -- The non-limited view may itself be incomplete, in which case
4641 -- get the full view if available.
4643 elsif From_With_Type (Id)
4644 and then Is_Type (Id)
4645 and then Ekind (Id) = E_Incomplete_Type
4646 and then Present (Non_Limited_View (Id))
4647 and then Scope (Non_Limited_View (Id)) = P_Name
4649 Candidate := Get_Full_View (Non_Limited_View (Id));
4650 Is_New_Candidate := True;
4653 Is_New_Candidate := False;
4656 if Is_New_Candidate then
4657 if Is_Child_Unit (Id) then
4658 exit when Is_Visible_Child_Unit (Id)
4659 or else Is_Immediately_Visible (Id);
4662 exit when not Is_Hidden (Id)
4663 or else Is_Immediately_Visible (Id);
4672 and then (Ekind (P_Name) = E_Procedure
4674 Ekind (P_Name) = E_Function)
4675 and then Is_Generic_Instance (P_Name)
4677 -- Expanded name denotes entity in (instance of) generic subprogram.
4678 -- The entity may be in the subprogram instance, or may denote one of
4679 -- the formals, which is declared in the enclosing wrapper package.
4681 P_Name := Scope (P_Name);
4683 Id := Current_Entity (Selector);
4684 while Present (Id) loop
4685 exit when Scope (Id) = P_Name;
4690 if No (Id) or else Chars (Id) /= Chars (Selector) then
4691 Set_Etype (N, Any_Type);
4693 -- If we are looking for an entity defined in System, try to find it
4694 -- in the child package that may have been provided as an extension
4695 -- to System. The Extend_System pragma will have supplied the name of
4696 -- the extension, which may have to be loaded.
4698 if Chars (P_Name) = Name_System
4699 and then Scope (P_Name) = Standard_Standard
4700 and then Present (System_Extend_Unit)
4701 and then Present_System_Aux (N)
4703 Set_Entity (Prefix (N), System_Aux_Id);
4704 Find_Expanded_Name (N);
4707 elsif Nkind (Selector) = N_Operator_Symbol
4708 and then Has_Implicit_Operator (N)
4710 -- There is an implicit instance of the predefined operator in
4711 -- the given scope. The operator entity is defined in Standard.
4712 -- Has_Implicit_Operator makes the node into an Expanded_Name.
4716 elsif Nkind (Selector) = N_Character_Literal
4717 and then Has_Implicit_Character_Literal (N)
4719 -- If there is no literal defined in the scope denoted by the
4720 -- prefix, the literal may belong to (a type derived from)
4721 -- Standard_Character, for which we have no explicit literals.
4726 -- If the prefix is a single concurrent object, use its name in
4727 -- the error message, rather than that of the anonymous type.
4729 if Is_Concurrent_Type (P_Name)
4730 and then Is_Internal_Name (Chars (P_Name))
4732 Error_Msg_Node_2 := Entity (Prefix (N));
4734 Error_Msg_Node_2 := P_Name;
4737 if P_Name = System_Aux_Id then
4738 P_Name := Scope (P_Name);
4739 Set_Entity (Prefix (N), P_Name);
4742 if Present (Candidate) then
4744 -- If we know that the unit is a child unit we can give a more
4745 -- accurate error message.
4747 if Is_Child_Unit (Candidate) then
4749 -- If the candidate is a private child unit and we are in
4750 -- the visible part of a public unit, specialize the error
4751 -- message. There might be a private with_clause for it,
4752 -- but it is not currently active.
4754 if Is_Private_Descendant (Candidate)
4755 and then Ekind (Current_Scope) = E_Package
4756 and then not In_Private_Part (Current_Scope)
4757 and then not Is_Private_Descendant (Current_Scope)
4759 Error_Msg_N ("private child unit& is not visible here",
4762 -- Normal case where we have a missing with for a child unit
4765 Error_Msg_Qual_Level := 99;
4766 Error_Msg_NE -- CODEFIX
4767 ("missing `WITH &;`", Selector, Candidate);
4768 Error_Msg_Qual_Level := 0;
4771 -- Here we don't know that this is a child unit
4774 Error_Msg_NE ("& is not a visible entity of&", N, Selector);
4778 -- Within the instantiation of a child unit, the prefix may
4779 -- denote the parent instance, but the selector has the name
4780 -- of the original child. Find whether we are within the
4781 -- corresponding instance, and get the proper entity, which
4782 -- can only be an enclosing scope.
4785 and then In_Open_Scopes (P_Name)
4786 and then Is_Generic_Instance (P_Name)
4789 S : Entity_Id := Current_Scope;
4793 for J in reverse 0 .. Scope_Stack.Last loop
4794 S := Scope_Stack.Table (J).Entity;
4796 exit when S = Standard_Standard;
4798 if Ekind_In (S, E_Function,
4802 P := Generic_Parent (Specification
4803 (Unit_Declaration_Node (S)));
4806 and then Chars (Scope (P)) = Chars (O_Name)
4807 and then Chars (P) = Chars (Selector)
4818 -- If this is a selection from Ada, System or Interfaces, then
4819 -- we assume a missing with for the corresponding package.
4821 if Is_Known_Unit (N) then
4822 if not Error_Posted (N) then
4823 Error_Msg_Node_2 := Selector;
4824 Error_Msg_N -- CODEFIX
4825 ("missing `WITH &.&;`", Prefix (N));
4828 -- If this is a selection from a dummy package, then suppress
4829 -- the error message, of course the entity is missing if the
4830 -- package is missing!
4832 elsif Sloc (Error_Msg_Node_2) = No_Location then
4835 -- Here we have the case of an undefined component
4839 -- The prefix may hide a homonym in the context that
4840 -- declares the desired entity. This error can use a
4841 -- specialized message.
4843 if In_Open_Scopes (P_Name)
4844 and then Present (Homonym (P_Name))
4845 and then Is_Compilation_Unit (Homonym (P_Name))
4847 (Is_Immediately_Visible (Homonym (P_Name))
4848 or else Is_Visible_Child_Unit (Homonym (P_Name)))
4851 H : constant Entity_Id := Homonym (P_Name);
4854 Id := First_Entity (H);
4855 while Present (Id) loop
4856 if Chars (Id) = Chars (Selector) then
4857 Error_Msg_Qual_Level := 99;
4858 Error_Msg_Name_1 := Chars (Selector);
4860 ("% not declared in&", N, P_Name);
4862 ("\use fully qualified name starting with"
4863 & " Standard to make& visible", N, H);
4864 Error_Msg_Qual_Level := 0;
4871 -- If not found, standard error message.
4873 Error_Msg_NE ("& not declared in&", N, Selector);
4879 Error_Msg_NE ("& not declared in&", N, Selector);
4882 -- Check for misspelling of some entity in prefix
4884 Id := First_Entity (P_Name);
4885 while Present (Id) loop
4886 if Is_Bad_Spelling_Of (Chars (Id), Chars (Selector))
4887 and then not Is_Internal_Name (Chars (Id))
4889 Error_Msg_NE -- CODEFIX
4890 ("possible misspelling of&", Selector, Id);
4897 -- Specialize the message if this may be an instantiation
4898 -- of a child unit that was not mentioned in the context.
4900 if Nkind (Parent (N)) = N_Package_Instantiation
4901 and then Is_Generic_Instance (Entity (Prefix (N)))
4902 and then Is_Compilation_Unit
4903 (Generic_Parent (Parent (Entity (Prefix (N)))))
4905 Error_Msg_Node_2 := Selector;
4906 Error_Msg_N -- CODEFIX
4907 ("\missing `WITH &.&;`", Prefix (N));
4917 if Comes_From_Source (N)
4918 and then Is_Remote_Access_To_Subprogram_Type (Id)
4919 and then Present (Equivalent_Type (Id))
4921 -- If we are not actually generating distribution code (i.e. the
4922 -- current PCS is the dummy non-distributed version), then the
4923 -- Equivalent_Type will be missing, and Id should be treated as
4924 -- a regular access-to-subprogram type.
4926 Id := Equivalent_Type (Id);
4927 Set_Chars (Selector, Chars (Id));
4930 -- Ada 2005 (AI-50217): Check usage of entities in limited withed units
4932 if Ekind (P_Name) = E_Package
4933 and then From_With_Type (P_Name)
4935 if From_With_Type (Id)
4936 or else Is_Type (Id)
4937 or else Ekind (Id) = E_Package
4942 ("limited withed package can only be used to access "
4943 & "incomplete types",
4948 if Is_Task_Type (P_Name)
4949 and then ((Ekind (Id) = E_Entry
4950 and then Nkind (Parent (N)) /= N_Attribute_Reference)
4952 (Ekind (Id) = E_Entry_Family
4954 Nkind (Parent (Parent (N))) /= N_Attribute_Reference))
4956 -- It is an entry call after all, either to the current task (which
4957 -- will deadlock) or to an enclosing task.
4959 Analyze_Selected_Component (N);
4963 Change_Selected_Component_To_Expanded_Name (N);
4965 -- Do style check and generate reference, but skip both steps if this
4966 -- entity has homonyms, since we may not have the right homonym set yet.
4967 -- The proper homonym will be set during the resolve phase.
4969 if Has_Homonym (Id) then
4972 Set_Entity_Or_Discriminal (N, Id);
4973 Generate_Reference (Id, N);
4976 if Is_Type (Id) then
4979 Set_Etype (N, Get_Full_View (Etype (Id)));
4982 -- Check for violation of No_Wide_Characters
4984 Check_Wide_Character_Restriction (Id, N);
4986 -- If the Ekind of the entity is Void, it means that all homonyms are
4987 -- hidden from all visibility (RM 8.3(5,14-20)).
4989 if Ekind (Id) = E_Void then
4990 Premature_Usage (N);
4992 elsif Is_Overloadable (Id)
4993 and then Present (Homonym (Id))
4996 H : Entity_Id := Homonym (Id);
4999 while Present (H) loop
5000 if Scope (H) = Scope (Id)
5003 or else Is_Immediately_Visible (H))
5005 Collect_Interps (N);
5012 -- If an extension of System is present, collect possible explicit
5013 -- overloadings declared in the extension.
5015 if Chars (P_Name) = Name_System
5016 and then Scope (P_Name) = Standard_Standard
5017 and then Present (System_Extend_Unit)
5018 and then Present_System_Aux (N)
5020 H := Current_Entity (Id);
5022 while Present (H) loop
5023 if Scope (H) = System_Aux_Id then
5024 Add_One_Interp (N, H, Etype (H));
5033 if Nkind (Selector_Name (N)) = N_Operator_Symbol
5034 and then Scope (Id) /= Standard_Standard
5036 -- In addition to user-defined operators in the given scope, there
5037 -- may be an implicit instance of the predefined operator. The
5038 -- operator (defined in Standard) is found in Has_Implicit_Operator,
5039 -- and added to the interpretations. Procedure Add_One_Interp will
5040 -- determine which hides which.
5042 if Has_Implicit_Operator (N) then
5046 end Find_Expanded_Name;
5048 -------------------------
5049 -- Find_Renamed_Entity --
5050 -------------------------
5052 function Find_Renamed_Entity
5056 Is_Actual : Boolean := False) return Entity_Id
5059 I1 : Interp_Index := 0; -- Suppress junk warnings
5065 function Enclosing_Instance return Entity_Id;
5066 -- If the renaming determines the entity for the default of a formal
5067 -- subprogram nested within another instance, choose the innermost
5068 -- candidate. This is because if the formal has a box, and we are within
5069 -- an enclosing instance where some candidate interpretations are local
5070 -- to this enclosing instance, we know that the default was properly
5071 -- resolved when analyzing the generic, so we prefer the local
5072 -- candidates to those that are external. This is not always the case
5073 -- but is a reasonable heuristic on the use of nested generics. The
5074 -- proper solution requires a full renaming model.
5076 function Is_Visible_Operation (Op : Entity_Id) return Boolean;
5077 -- If the renamed entity is an implicit operator, check whether it is
5078 -- visible because its operand type is properly visible. This check
5079 -- applies to explicit renamed entities that appear in the source in a
5080 -- renaming declaration or a formal subprogram instance, but not to
5081 -- default generic actuals with a name.
5083 function Report_Overload return Entity_Id;
5084 -- List possible interpretations, and specialize message in the
5085 -- case of a generic actual.
5087 function Within (Inner, Outer : Entity_Id) return Boolean;
5088 -- Determine whether a candidate subprogram is defined within the
5089 -- enclosing instance. If yes, it has precedence over outer candidates.
5091 ------------------------
5092 -- Enclosing_Instance --
5093 ------------------------
5095 function Enclosing_Instance return Entity_Id is
5099 if not Is_Generic_Instance (Current_Scope)
5100 and then not Is_Actual
5105 S := Scope (Current_Scope);
5106 while S /= Standard_Standard loop
5107 if Is_Generic_Instance (S) then
5115 end Enclosing_Instance;
5117 --------------------------
5118 -- Is_Visible_Operation --
5119 --------------------------
5121 function Is_Visible_Operation (Op : Entity_Id) return Boolean is
5127 if Ekind (Op) /= E_Operator
5128 or else Scope (Op) /= Standard_Standard
5129 or else (In_Instance
5132 or else Present (Enclosing_Instance)))
5137 -- For a fixed point type operator, check the resulting type,
5138 -- because it may be a mixed mode integer * fixed operation.
5140 if Present (Next_Formal (First_Formal (New_S)))
5141 and then Is_Fixed_Point_Type (Etype (New_S))
5143 Typ := Etype (New_S);
5145 Typ := Etype (First_Formal (New_S));
5148 Btyp := Base_Type (Typ);
5150 if Nkind (Nam) /= N_Expanded_Name then
5151 return (In_Open_Scopes (Scope (Btyp))
5152 or else Is_Potentially_Use_Visible (Btyp)
5153 or else In_Use (Btyp)
5154 or else In_Use (Scope (Btyp)));
5157 Scop := Entity (Prefix (Nam));
5159 if Ekind (Scop) = E_Package
5160 and then Present (Renamed_Object (Scop))
5162 Scop := Renamed_Object (Scop);
5165 -- Operator is visible if prefix of expanded name denotes
5166 -- scope of type, or else type is defined in System_Aux
5167 -- and the prefix denotes System.
5169 return Scope (Btyp) = Scop
5170 or else (Scope (Btyp) = System_Aux_Id
5171 and then Scope (Scope (Btyp)) = Scop);
5174 end Is_Visible_Operation;
5180 function Within (Inner, Outer : Entity_Id) return Boolean is
5184 Sc := Scope (Inner);
5185 while Sc /= Standard_Standard loop
5196 ---------------------
5197 -- Report_Overload --
5198 ---------------------
5200 function Report_Overload return Entity_Id is
5203 Error_Msg_NE -- CODEFIX
5204 ("ambiguous actual subprogram&, " &
5205 "possible interpretations:", N, Nam);
5207 Error_Msg_N -- CODEFIX
5208 ("ambiguous subprogram, " &
5209 "possible interpretations:", N);
5212 List_Interps (Nam, N);
5214 end Report_Overload;
5216 -- Start of processing for Find_Renamed_Entry
5220 Candidate_Renaming := Empty;
5222 if not Is_Overloaded (Nam) then
5223 if Entity_Matches_Spec (Entity (Nam), New_S) then
5224 Candidate_Renaming := New_S;
5226 if Is_Visible_Operation (Entity (Nam)) then
5227 Old_S := Entity (Nam);
5231 Present (First_Formal (Entity (Nam)))
5232 and then Present (First_Formal (New_S))
5233 and then (Base_Type (Etype (First_Formal (Entity (Nam))))
5234 = Base_Type (Etype (First_Formal (New_S))))
5236 Candidate_Renaming := Entity (Nam);
5240 Get_First_Interp (Nam, Ind, It);
5241 while Present (It.Nam) loop
5242 if Entity_Matches_Spec (It.Nam, New_S)
5243 and then Is_Visible_Operation (It.Nam)
5245 if Old_S /= Any_Id then
5247 -- Note: The call to Disambiguate only happens if a
5248 -- previous interpretation was found, in which case I1
5249 -- has received a value.
5251 It1 := Disambiguate (Nam, I1, Ind, Etype (Old_S));
5253 if It1 = No_Interp then
5254 Inst := Enclosing_Instance;
5256 if Present (Inst) then
5257 if Within (It.Nam, Inst) then
5259 elsif Within (Old_S, Inst) then
5262 return Report_Overload;
5266 return Report_Overload;
5280 Present (First_Formal (It.Nam))
5281 and then Present (First_Formal (New_S))
5282 and then (Base_Type (Etype (First_Formal (It.Nam)))
5283 = Base_Type (Etype (First_Formal (New_S))))
5285 Candidate_Renaming := It.Nam;
5288 Get_Next_Interp (Ind, It);
5291 Set_Entity (Nam, Old_S);
5292 Set_Is_Overloaded (Nam, False);
5296 end Find_Renamed_Entity;
5298 -----------------------------
5299 -- Find_Selected_Component --
5300 -----------------------------
5302 procedure Find_Selected_Component (N : Node_Id) is
5303 P : constant Node_Id := Prefix (N);
5306 -- Entity denoted by prefix
5316 if Nkind (P) = N_Error then
5319 -- If the selector already has an entity, the node has been constructed
5320 -- in the course of expansion, and is known to be valid. Do not verify
5321 -- that it is defined for the type (it may be a private component used
5322 -- in the expansion of record equality).
5324 elsif Present (Entity (Selector_Name (N))) then
5326 or else Etype (N) = Any_Type
5329 Sel_Name : constant Node_Id := Selector_Name (N);
5330 Selector : constant Entity_Id := Entity (Sel_Name);
5334 Set_Etype (Sel_Name, Etype (Selector));
5336 if not Is_Entity_Name (P) then
5340 -- Build an actual subtype except for the first parameter
5341 -- of an init proc, where this actual subtype is by
5342 -- definition incorrect, since the object is uninitialized
5343 -- (and does not even have defined discriminants etc.)
5345 if Is_Entity_Name (P)
5346 and then Ekind (Entity (P)) = E_Function
5348 Nam := New_Copy (P);
5350 if Is_Overloaded (P) then
5351 Save_Interps (P, Nam);
5355 Make_Function_Call (Sloc (P), Name => Nam));
5357 Analyze_Selected_Component (N);
5360 elsif Ekind (Selector) = E_Component
5361 and then (not Is_Entity_Name (P)
5362 or else Chars (Entity (P)) /= Name_uInit)
5365 Build_Actual_Subtype_Of_Component (
5366 Etype (Selector), N);
5371 if No (C_Etype) then
5372 C_Etype := Etype (Selector);
5374 Insert_Action (N, C_Etype);
5375 C_Etype := Defining_Identifier (C_Etype);
5378 Set_Etype (N, C_Etype);
5381 -- If this is the name of an entry or protected operation, and
5382 -- the prefix is an access type, insert an explicit dereference,
5383 -- so that entry calls are treated uniformly.
5385 if Is_Access_Type (Etype (P))
5386 and then Is_Concurrent_Type (Designated_Type (Etype (P)))
5389 New_P : constant Node_Id :=
5390 Make_Explicit_Dereference (Sloc (P),
5391 Prefix => Relocate_Node (P));
5394 Set_Etype (P, Designated_Type (Etype (Prefix (P))));
5398 -- If the selected component appears within a default expression
5399 -- and it has an actual subtype, the pre-analysis has not yet
5400 -- completed its analysis, because Insert_Actions is disabled in
5401 -- that context. Within the init proc of the enclosing type we
5402 -- must complete this analysis, if an actual subtype was created.
5404 elsif Inside_Init_Proc then
5406 Typ : constant Entity_Id := Etype (N);
5407 Decl : constant Node_Id := Declaration_Node (Typ);
5409 if Nkind (Decl) = N_Subtype_Declaration
5410 and then not Analyzed (Decl)
5411 and then Is_List_Member (Decl)
5412 and then No (Parent (Decl))
5415 Insert_Action (N, Decl);
5422 elsif Is_Entity_Name (P) then
5423 P_Name := Entity (P);
5425 -- The prefix may denote an enclosing type which is the completion
5426 -- of an incomplete type declaration.
5428 if Is_Type (P_Name) then
5429 Set_Entity (P, Get_Full_View (P_Name));
5430 Set_Etype (P, Entity (P));
5431 P_Name := Entity (P);
5434 P_Type := Base_Type (Etype (P));
5436 if Debug_Flag_E then
5437 Write_Str ("Found prefix type to be ");
5438 Write_Entity_Info (P_Type, " "); Write_Eol;
5441 -- First check for components of a record object (not the
5442 -- result of a call, which is handled below).
5444 if Is_Appropriate_For_Record (P_Type)
5445 and then not Is_Overloadable (P_Name)
5446 and then not Is_Type (P_Name)
5448 -- Selected component of record. Type checking will validate
5449 -- name of selector.
5450 -- ??? could we rewrite an implicit dereference into an explicit
5453 Analyze_Selected_Component (N);
5455 elsif Is_Appropriate_For_Entry_Prefix (P_Type)
5456 and then not In_Open_Scopes (P_Name)
5457 and then (not Is_Concurrent_Type (Etype (P_Name))
5458 or else not In_Open_Scopes (Etype (P_Name)))
5460 -- Call to protected operation or entry. Type checking is
5461 -- needed on the prefix.
5463 Analyze_Selected_Component (N);
5465 elsif (In_Open_Scopes (P_Name)
5466 and then Ekind (P_Name) /= E_Void
5467 and then not Is_Overloadable (P_Name))
5468 or else (Is_Concurrent_Type (Etype (P_Name))
5469 and then In_Open_Scopes (Etype (P_Name)))
5471 -- Prefix denotes an enclosing loop, block, or task, i.e. an
5472 -- enclosing construct that is not a subprogram or accept.
5474 Find_Expanded_Name (N);
5476 elsif Ekind (P_Name) = E_Package then
5477 Find_Expanded_Name (N);
5479 elsif Is_Overloadable (P_Name) then
5481 -- The subprogram may be a renaming (of an enclosing scope) as
5482 -- in the case of the name of the generic within an instantiation.
5484 if (Ekind (P_Name) = E_Procedure
5485 or else Ekind (P_Name) = E_Function)
5486 and then Present (Alias (P_Name))
5487 and then Is_Generic_Instance (Alias (P_Name))
5489 P_Name := Alias (P_Name);
5492 if Is_Overloaded (P) then
5494 -- The prefix must resolve to a unique enclosing construct
5497 Found : Boolean := False;
5502 Get_First_Interp (P, Ind, It);
5503 while Present (It.Nam) loop
5504 if In_Open_Scopes (It.Nam) then
5507 "prefix must be unique enclosing scope", N);
5508 Set_Entity (N, Any_Id);
5509 Set_Etype (N, Any_Type);
5518 Get_Next_Interp (Ind, It);
5523 if In_Open_Scopes (P_Name) then
5524 Set_Entity (P, P_Name);
5525 Set_Is_Overloaded (P, False);
5526 Find_Expanded_Name (N);
5529 -- If no interpretation as an expanded name is possible, it
5530 -- must be a selected component of a record returned by a
5531 -- function call. Reformat prefix as a function call, the rest
5532 -- is done by type resolution. If the prefix is procedure or
5533 -- entry, as is P.X; this is an error.
5535 if Ekind (P_Name) /= E_Function
5536 and then (not Is_Overloaded (P)
5538 Nkind (Parent (N)) = N_Procedure_Call_Statement)
5540 -- Prefix may mention a package that is hidden by a local
5541 -- declaration: let the user know. Scan the full homonym
5542 -- chain, the candidate package may be anywhere on it.
5544 if Present (Homonym (Current_Entity (P_Name))) then
5546 P_Name := Current_Entity (P_Name);
5548 while Present (P_Name) loop
5549 exit when Ekind (P_Name) = E_Package;
5550 P_Name := Homonym (P_Name);
5553 if Present (P_Name) then
5554 Error_Msg_Sloc := Sloc (Entity (Prefix (N)));
5557 ("package& is hidden by declaration#",
5560 Set_Entity (Prefix (N), P_Name);
5561 Find_Expanded_Name (N);
5564 P_Name := Entity (Prefix (N));
5569 ("invalid prefix in selected component&", N, P_Name);
5570 Change_Selected_Component_To_Expanded_Name (N);
5571 Set_Entity (N, Any_Id);
5572 Set_Etype (N, Any_Type);
5575 Nam := New_Copy (P);
5576 Save_Interps (P, Nam);
5578 Make_Function_Call (Sloc (P), Name => Nam));
5580 Analyze_Selected_Component (N);
5584 -- Remaining cases generate various error messages
5587 -- Format node as expanded name, to avoid cascaded errors
5589 Change_Selected_Component_To_Expanded_Name (N);
5590 Set_Entity (N, Any_Id);
5591 Set_Etype (N, Any_Type);
5593 -- Issue error message, but avoid this if error issued already.
5594 -- Use identifier of prefix if one is available.
5596 if P_Name = Any_Id then
5599 elsif Ekind (P_Name) = E_Void then
5600 Premature_Usage (P);
5602 elsif Nkind (P) /= N_Attribute_Reference then
5604 "invalid prefix in selected component&", P);
5606 if Is_Access_Type (P_Type)
5607 and then Ekind (Designated_Type (P_Type)) = E_Incomplete_Type
5610 ("\dereference must not be of an incomplete type " &
5616 "invalid prefix in selected component", P);
5621 -- If prefix is not the name of an entity, it must be an expression,
5622 -- whose type is appropriate for a record. This is determined by
5625 Analyze_Selected_Component (N);
5627 end Find_Selected_Component;
5633 procedure Find_Type (N : Node_Id) is
5643 elsif Nkind (N) = N_Attribute_Reference then
5645 -- Class attribute. This is not valid in Ada 83 mode, but we do not
5646 -- need to enforce that at this point, since the declaration of the
5647 -- tagged type in the prefix would have been flagged already.
5649 if Attribute_Name (N) = Name_Class then
5650 Check_Restriction (No_Dispatch, N);
5651 Find_Type (Prefix (N));
5653 -- Propagate error from bad prefix
5655 if Etype (Prefix (N)) = Any_Type then
5656 Set_Entity (N, Any_Type);
5657 Set_Etype (N, Any_Type);
5661 T := Base_Type (Entity (Prefix (N)));
5663 -- Case where type is not known to be tagged. Its appearance in
5664 -- the prefix of the 'Class attribute indicates that the full view
5667 if not Is_Tagged_Type (T) then
5668 if Ekind (T) = E_Incomplete_Type then
5670 -- It is legal to denote the class type of an incomplete
5671 -- type. The full type will have to be tagged, of course.
5672 -- In Ada 2005 this usage is declared obsolescent, so we
5673 -- warn accordingly. This usage is only legal if the type
5674 -- is completed in the current scope, and not for a limited
5677 if not Is_Tagged_Type (T)
5678 and then Ada_Version >= Ada_05
5680 if From_With_Type (T) then
5682 ("prefix of Class attribute must be tagged", N);
5683 Set_Etype (N, Any_Type);
5684 Set_Entity (N, Any_Type);
5687 -- ??? This test is temporarily disabled (always False)
5688 -- because it causes an unwanted warning on GNAT sources
5689 -- (built with -gnatg, which includes Warn_On_Obsolescent_
5690 -- Feature). Once this issue is cleared in the sources, it
5693 elsif Warn_On_Obsolescent_Feature
5697 ("applying 'Class to an untagged incomplete type"
5698 & " is an obsolescent feature (RM J.11)", N);
5702 Set_Is_Tagged_Type (T);
5703 Set_Primitive_Operations (T, New_Elmt_List);
5704 Make_Class_Wide_Type (T);
5705 Set_Entity (N, Class_Wide_Type (T));
5706 Set_Etype (N, Class_Wide_Type (T));
5708 elsif Ekind (T) = E_Private_Type
5709 and then not Is_Generic_Type (T)
5710 and then In_Private_Part (Scope (T))
5712 -- The Class attribute can be applied to an untagged private
5713 -- type fulfilled by a tagged type prior to the full type
5714 -- declaration (but only within the parent package's private
5715 -- part). Create the class-wide type now and check that the
5716 -- full type is tagged later during its analysis. Note that
5717 -- we do not mark the private type as tagged, unlike the
5718 -- case of incomplete types, because the type must still
5719 -- appear untagged to outside units.
5721 if No (Class_Wide_Type (T)) then
5722 Make_Class_Wide_Type (T);
5725 Set_Entity (N, Class_Wide_Type (T));
5726 Set_Etype (N, Class_Wide_Type (T));
5729 -- Should we introduce a type Any_Tagged and use Wrong_Type
5730 -- here, it would be a bit more consistent???
5733 ("tagged type required, found}",
5734 Prefix (N), First_Subtype (T));
5735 Set_Entity (N, Any_Type);
5739 -- Case of tagged type
5742 if Is_Concurrent_Type (T) then
5743 if No (Corresponding_Record_Type (Entity (Prefix (N)))) then
5745 -- Previous error. Use current type, which at least
5746 -- provides some operations.
5748 C := Entity (Prefix (N));
5751 C := Class_Wide_Type
5752 (Corresponding_Record_Type (Entity (Prefix (N))));
5756 C := Class_Wide_Type (Entity (Prefix (N)));
5759 Set_Entity_With_Style_Check (N, C);
5760 Generate_Reference (C, N);
5764 -- Base attribute, not allowed in Ada 83
5766 elsif Attribute_Name (N) = Name_Base then
5767 if Ada_Version = Ada_83 and then Comes_From_Source (N) then
5769 ("(Ada 83) Base attribute not allowed in subtype mark", N);
5772 Find_Type (Prefix (N));
5773 Typ := Entity (Prefix (N));
5775 if Ada_Version >= Ada_95
5776 and then not Is_Scalar_Type (Typ)
5777 and then not Is_Generic_Type (Typ)
5780 ("prefix of Base attribute must be scalar type",
5783 elsif Warn_On_Redundant_Constructs
5784 and then Base_Type (Typ) = Typ
5786 Error_Msg_NE -- CODEFIX
5787 ("?redundant attribute, & is its own base type", N, Typ);
5790 T := Base_Type (Typ);
5792 -- Rewrite attribute reference with type itself (see similar
5793 -- processing in Analyze_Attribute, case Base). Preserve prefix
5794 -- if present, for other legality checks.
5796 if Nkind (Prefix (N)) = N_Expanded_Name then
5798 Make_Expanded_Name (Sloc (N),
5800 Prefix => New_Copy (Prefix (Prefix (N))),
5801 Selector_Name => New_Reference_To (T, Sloc (N))));
5804 Rewrite (N, New_Reference_To (T, Sloc (N)));
5811 elsif Attribute_Name (N) = Name_Stub_Type then
5813 -- This is handled in Analyze_Attribute
5817 -- All other attributes are invalid in a subtype mark
5820 Error_Msg_N ("invalid attribute in subtype mark", N);
5826 if Is_Entity_Name (N) then
5827 T_Name := Entity (N);
5829 Error_Msg_N ("subtype mark required in this context", N);
5830 Set_Etype (N, Any_Type);
5834 if T_Name = Any_Id or else Etype (N) = Any_Type then
5836 -- Undefined id. Make it into a valid type
5838 Set_Entity (N, Any_Type);
5840 elsif not Is_Type (T_Name)
5841 and then T_Name /= Standard_Void_Type
5843 Error_Msg_Sloc := Sloc (T_Name);
5844 Error_Msg_N ("subtype mark required in this context", N);
5845 Error_Msg_NE ("\\found & declared#", N, T_Name);
5846 Set_Entity (N, Any_Type);
5849 -- If the type is an incomplete type created to handle
5850 -- anonymous access components of a record type, then the
5851 -- incomplete type is the visible entity and subsequent
5852 -- references will point to it. Mark the original full
5853 -- type as referenced, to prevent spurious warnings.
5855 if Is_Incomplete_Type (T_Name)
5856 and then Present (Full_View (T_Name))
5857 and then not Comes_From_Source (T_Name)
5859 Set_Referenced (Full_View (T_Name));
5862 T_Name := Get_Full_View (T_Name);
5864 -- Ada 2005 (AI-251, AI-50217): Handle interfaces visible through
5865 -- limited-with clauses
5867 if From_With_Type (T_Name)
5868 and then Ekind (T_Name) in Incomplete_Kind
5869 and then Present (Non_Limited_View (T_Name))
5870 and then Is_Interface (Non_Limited_View (T_Name))
5872 T_Name := Non_Limited_View (T_Name);
5875 if In_Open_Scopes (T_Name) then
5876 if Ekind (Base_Type (T_Name)) = E_Task_Type then
5878 -- In Ada 2005, a task name can be used in an access
5879 -- definition within its own body. It cannot be used
5880 -- in the discriminant part of the task declaration,
5881 -- nor anywhere else in the declaration because entries
5882 -- cannot have access parameters.
5884 if Ada_Version >= Ada_05
5885 and then Nkind (Parent (N)) = N_Access_Definition
5887 Set_Entity (N, T_Name);
5888 Set_Etype (N, T_Name);
5890 if Has_Completion (T_Name) then
5895 ("task type cannot be used as type mark " &
5896 "within its own declaration", N);
5901 ("task type cannot be used as type mark " &
5902 "within its own spec or body", N);
5905 elsif Ekind (Base_Type (T_Name)) = E_Protected_Type then
5907 -- In Ada 2005, a protected name can be used in an access
5908 -- definition within its own body.
5910 if Ada_Version >= Ada_05
5911 and then Nkind (Parent (N)) = N_Access_Definition
5913 Set_Entity (N, T_Name);
5914 Set_Etype (N, T_Name);
5919 ("protected type cannot be used as type mark " &
5920 "within its own spec or body", N);
5924 Error_Msg_N ("type declaration cannot refer to itself", N);
5927 Set_Etype (N, Any_Type);
5928 Set_Entity (N, Any_Type);
5929 Set_Error_Posted (T_Name);
5933 Set_Entity (N, T_Name);
5934 Set_Etype (N, T_Name);
5938 if Present (Etype (N)) and then Comes_From_Source (N) then
5939 if Is_Fixed_Point_Type (Etype (N)) then
5940 Check_Restriction (No_Fixed_Point, N);
5941 elsif Is_Floating_Point_Type (Etype (N)) then
5942 Check_Restriction (No_Floating_Point, N);
5947 ------------------------------------
5948 -- Has_Implicit_Character_Literal --
5949 ------------------------------------
5951 function Has_Implicit_Character_Literal (N : Node_Id) return Boolean is
5953 Found : Boolean := False;
5954 P : constant Entity_Id := Entity (Prefix (N));
5955 Priv_Id : Entity_Id := Empty;
5958 if Ekind (P) = E_Package
5959 and then not In_Open_Scopes (P)
5961 Priv_Id := First_Private_Entity (P);
5964 if P = Standard_Standard then
5965 Change_Selected_Component_To_Expanded_Name (N);
5966 Rewrite (N, Selector_Name (N));
5968 Set_Etype (Original_Node (N), Standard_Character);
5972 Id := First_Entity (P);
5974 and then Id /= Priv_Id
5976 if Is_Standard_Character_Type (Id)
5977 and then Id = Base_Type (Id)
5979 -- We replace the node with the literal itself, resolve as a
5980 -- character, and set the type correctly.
5983 Change_Selected_Component_To_Expanded_Name (N);
5984 Rewrite (N, Selector_Name (N));
5987 Set_Etype (Original_Node (N), Id);
5991 -- More than one type derived from Character in given scope.
5992 -- Collect all possible interpretations.
5994 Add_One_Interp (N, Id, Id);
6002 end Has_Implicit_Character_Literal;
6004 ----------------------
6005 -- Has_Private_With --
6006 ----------------------
6008 function Has_Private_With (E : Entity_Id) return Boolean is
6009 Comp_Unit : constant Node_Id := Cunit (Current_Sem_Unit);
6013 Item := First (Context_Items (Comp_Unit));
6014 while Present (Item) loop
6015 if Nkind (Item) = N_With_Clause
6016 and then Private_Present (Item)
6017 and then Entity (Name (Item)) = E
6026 end Has_Private_With;
6028 ---------------------------
6029 -- Has_Implicit_Operator --
6030 ---------------------------
6032 function Has_Implicit_Operator (N : Node_Id) return Boolean is
6033 Op_Id : constant Name_Id := Chars (Selector_Name (N));
6034 P : constant Entity_Id := Entity (Prefix (N));
6036 Priv_Id : Entity_Id := Empty;
6038 procedure Add_Implicit_Operator
6040 Op_Type : Entity_Id := Empty);
6041 -- Add implicit interpretation to node N, using the type for which a
6042 -- predefined operator exists. If the operator yields a boolean type,
6043 -- the Operand_Type is implicitly referenced by the operator, and a
6044 -- reference to it must be generated.
6046 ---------------------------
6047 -- Add_Implicit_Operator --
6048 ---------------------------
6050 procedure Add_Implicit_Operator
6052 Op_Type : Entity_Id := Empty)
6054 Predef_Op : Entity_Id;
6057 Predef_Op := Current_Entity (Selector_Name (N));
6059 while Present (Predef_Op)
6060 and then Scope (Predef_Op) /= Standard_Standard
6062 Predef_Op := Homonym (Predef_Op);
6065 if Nkind (N) = N_Selected_Component then
6066 Change_Selected_Component_To_Expanded_Name (N);
6069 -- If the context is an unanalyzed function call, determine whether
6070 -- a binary or unary interpretation is required.
6072 if Nkind (Parent (N)) = N_Indexed_Component then
6074 Is_Binary_Call : constant Boolean :=
6076 (Next (First (Expressions (Parent (N)))));
6077 Is_Binary_Op : constant Boolean :=
6079 (Predef_Op) /= Last_Entity (Predef_Op);
6080 Predef_Op2 : constant Entity_Id := Homonym (Predef_Op);
6083 if Is_Binary_Call then
6084 if Is_Binary_Op then
6085 Add_One_Interp (N, Predef_Op, T);
6087 Add_One_Interp (N, Predef_Op2, T);
6091 if not Is_Binary_Op then
6092 Add_One_Interp (N, Predef_Op, T);
6094 Add_One_Interp (N, Predef_Op2, T);
6100 Add_One_Interp (N, Predef_Op, T);
6102 -- For operators with unary and binary interpretations, if
6103 -- context is not a call, add both
6105 if Present (Homonym (Predef_Op)) then
6106 Add_One_Interp (N, Homonym (Predef_Op), T);
6110 -- The node is a reference to a predefined operator, and
6111 -- an implicit reference to the type of its operands.
6113 if Present (Op_Type) then
6114 Generate_Operator_Reference (N, Op_Type);
6116 Generate_Operator_Reference (N, T);
6118 end Add_Implicit_Operator;
6120 -- Start of processing for Has_Implicit_Operator
6123 if Ekind (P) = E_Package
6124 and then not In_Open_Scopes (P)
6126 Priv_Id := First_Private_Entity (P);
6129 Id := First_Entity (P);
6133 -- Boolean operators: an implicit declaration exists if the scope
6134 -- contains a declaration for a derived Boolean type, or for an
6135 -- array of Boolean type.
6137 when Name_Op_And | Name_Op_Not | Name_Op_Or | Name_Op_Xor =>
6138 while Id /= Priv_Id loop
6139 if Valid_Boolean_Arg (Id)
6140 and then Id = Base_Type (Id)
6142 Add_Implicit_Operator (Id);
6149 -- Equality: look for any non-limited type (result is Boolean)
6151 when Name_Op_Eq | Name_Op_Ne =>
6152 while Id /= Priv_Id loop
6154 and then not Is_Limited_Type (Id)
6155 and then Id = Base_Type (Id)
6157 Add_Implicit_Operator (Standard_Boolean, Id);
6164 -- Comparison operators: scalar type, or array of scalar
6166 when Name_Op_Lt | Name_Op_Le | Name_Op_Gt | Name_Op_Ge =>
6167 while Id /= Priv_Id loop
6168 if (Is_Scalar_Type (Id)
6169 or else (Is_Array_Type (Id)
6170 and then Is_Scalar_Type (Component_Type (Id))))
6171 and then Id = Base_Type (Id)
6173 Add_Implicit_Operator (Standard_Boolean, Id);
6180 -- Arithmetic operators: any numeric type
6190 while Id /= Priv_Id loop
6191 if Is_Numeric_Type (Id)
6192 and then Id = Base_Type (Id)
6194 Add_Implicit_Operator (Id);
6201 -- Concatenation: any one-dimensional array type
6203 when Name_Op_Concat =>
6204 while Id /= Priv_Id loop
6205 if Is_Array_Type (Id) and then Number_Dimensions (Id) = 1
6206 and then Id = Base_Type (Id)
6208 Add_Implicit_Operator (Id);
6215 -- What is the others condition here? Should we be using a
6216 -- subtype of Name_Id that would restrict to operators ???
6218 when others => null;
6221 -- If we fall through, then we do not have an implicit operator
6225 end Has_Implicit_Operator;
6227 --------------------
6228 -- In_Open_Scopes --
6229 --------------------
6231 function In_Open_Scopes (S : Entity_Id) return Boolean is
6233 -- Several scope stacks are maintained by Scope_Stack. The base of the
6234 -- currently active scope stack is denoted by the Is_Active_Stack_Base
6235 -- flag in the scope stack entry. Note that the scope stacks used to
6236 -- simply be delimited implicitly by the presence of Standard_Standard
6237 -- at their base, but there now are cases where this is not sufficient
6238 -- because Standard_Standard actually may appear in the middle of the
6239 -- active set of scopes.
6241 for J in reverse 0 .. Scope_Stack.Last loop
6242 if Scope_Stack.Table (J).Entity = S then
6246 -- Check Is_Active_Stack_Base to tell us when to stop, as there are
6247 -- cases where Standard_Standard appears in the middle of the active
6248 -- set of scopes. This affects the declaration and overriding of
6249 -- private inherited operations in instantiations of generic child
6252 exit when Scope_Stack.Table (J).Is_Active_Stack_Base;
6258 -----------------------------
6259 -- Inherit_Renamed_Profile --
6260 -----------------------------
6262 procedure Inherit_Renamed_Profile (New_S : Entity_Id; Old_S : Entity_Id) is
6269 if Ekind (Old_S) = E_Operator then
6270 New_F := First_Formal (New_S);
6272 while Present (New_F) loop
6273 Set_Etype (New_F, Base_Type (Etype (New_F)));
6274 Next_Formal (New_F);
6277 Set_Etype (New_S, Base_Type (Etype (New_S)));
6280 New_F := First_Formal (New_S);
6281 Old_F := First_Formal (Old_S);
6283 while Present (New_F) loop
6284 New_T := Etype (New_F);
6285 Old_T := Etype (Old_F);
6287 -- If the new type is a renaming of the old one, as is the
6288 -- case for actuals in instances, retain its name, to simplify
6289 -- later disambiguation.
6291 if Nkind (Parent (New_T)) = N_Subtype_Declaration
6292 and then Is_Entity_Name (Subtype_Indication (Parent (New_T)))
6293 and then Entity (Subtype_Indication (Parent (New_T))) = Old_T
6297 Set_Etype (New_F, Old_T);
6300 Next_Formal (New_F);
6301 Next_Formal (Old_F);
6304 if Ekind_In (Old_S, E_Function, E_Enumeration_Literal) then
6305 Set_Etype (New_S, Etype (Old_S));
6308 end Inherit_Renamed_Profile;
6314 procedure Initialize is
6319 -------------------------
6320 -- Install_Use_Clauses --
6321 -------------------------
6323 procedure Install_Use_Clauses
6325 Force_Installation : Boolean := False)
6333 while Present (U) loop
6335 -- Case of USE package
6337 if Nkind (U) = N_Use_Package_Clause then
6338 P := First (Names (U));
6339 while Present (P) loop
6342 if Ekind (Id) = E_Package then
6344 Note_Redundant_Use (P);
6346 elsif Present (Renamed_Object (Id))
6347 and then In_Use (Renamed_Object (Id))
6349 Note_Redundant_Use (P);
6351 elsif Force_Installation or else Applicable_Use (P) then
6352 Use_One_Package (Id, U);
6363 P := First (Subtype_Marks (U));
6364 while Present (P) loop
6365 if not Is_Entity_Name (P)
6366 or else No (Entity (P))
6370 elsif Entity (P) /= Any_Type then
6378 Next_Use_Clause (U);
6380 end Install_Use_Clauses;
6382 -------------------------------------
6383 -- Is_Appropriate_For_Entry_Prefix --
6384 -------------------------------------
6386 function Is_Appropriate_For_Entry_Prefix (T : Entity_Id) return Boolean is
6387 P_Type : Entity_Id := T;
6390 if Is_Access_Type (P_Type) then
6391 P_Type := Designated_Type (P_Type);
6394 return Is_Task_Type (P_Type) or else Is_Protected_Type (P_Type);
6395 end Is_Appropriate_For_Entry_Prefix;
6397 -------------------------------
6398 -- Is_Appropriate_For_Record --
6399 -------------------------------
6401 function Is_Appropriate_For_Record (T : Entity_Id) return Boolean is
6403 function Has_Components (T1 : Entity_Id) return Boolean;
6404 -- Determine if given type has components (i.e. is either a record
6405 -- type or a type that has discriminants).
6407 --------------------
6408 -- Has_Components --
6409 --------------------
6411 function Has_Components (T1 : Entity_Id) return Boolean is
6413 return Is_Record_Type (T1)
6414 or else (Is_Private_Type (T1) and then Has_Discriminants (T1))
6415 or else (Is_Task_Type (T1) and then Has_Discriminants (T1))
6416 or else (Is_Incomplete_Type (T1)
6417 and then From_With_Type (T1)
6418 and then Present (Non_Limited_View (T1))
6419 and then Is_Record_Type
6420 (Get_Full_View (Non_Limited_View (T1))));
6423 -- Start of processing for Is_Appropriate_For_Record
6428 and then (Has_Components (T)
6429 or else (Is_Access_Type (T)
6430 and then Has_Components (Designated_Type (T))));
6431 end Is_Appropriate_For_Record;
6433 ------------------------
6434 -- Note_Redundant_Use --
6435 ------------------------
6437 procedure Note_Redundant_Use (Clause : Node_Id) is
6438 Pack_Name : constant Entity_Id := Entity (Clause);
6439 Cur_Use : constant Node_Id := Current_Use_Clause (Pack_Name);
6440 Decl : constant Node_Id := Parent (Clause);
6442 Prev_Use : Node_Id := Empty;
6443 Redundant : Node_Id := Empty;
6444 -- The Use_Clause which is actually redundant. In the simplest case it
6445 -- is Pack itself, but when we compile a body we install its context
6446 -- before that of its spec, in which case it is the use_clause in the
6447 -- spec that will appear to be redundant, and we want the warning to be
6448 -- placed on the body. Similar complications appear when the redundancy
6449 -- is between a child unit and one of its ancestors.
6452 Set_Redundant_Use (Clause, True);
6454 if not Comes_From_Source (Clause)
6456 or else not Warn_On_Redundant_Constructs
6461 if not Is_Compilation_Unit (Current_Scope) then
6463 -- If the use_clause is in an inner scope, it is made redundant by
6464 -- some clause in the current context, with one exception: If we're
6465 -- compiling a nested package body, and the use_clause comes from the
6466 -- corresponding spec, the clause is not necessarily fully redundant,
6467 -- so we should not warn. If a warning was warranted, it would have
6468 -- been given when the spec was processed.
6470 if Nkind (Parent (Decl)) = N_Package_Specification then
6472 Package_Spec_Entity : constant Entity_Id :=
6473 Defining_Unit_Name (Parent (Decl));
6475 if In_Package_Body (Package_Spec_Entity) then
6481 Redundant := Clause;
6482 Prev_Use := Cur_Use;
6484 elsif Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Body then
6486 Cur_Unit : constant Unit_Number_Type := Get_Source_Unit (Cur_Use);
6487 New_Unit : constant Unit_Number_Type := Get_Source_Unit (Clause);
6491 if Cur_Unit = New_Unit then
6493 -- Redundant clause in same body
6495 Redundant := Clause;
6496 Prev_Use := Cur_Use;
6498 elsif Cur_Unit = Current_Sem_Unit then
6500 -- If the new clause is not in the current unit it has been
6501 -- analyzed first, and it makes the other one redundant.
6502 -- However, if the new clause appears in a subunit, Cur_Unit
6503 -- is still the parent, and in that case the redundant one
6504 -- is the one appearing in the subunit.
6506 if Nkind (Unit (Cunit (New_Unit))) = N_Subunit then
6507 Redundant := Clause;
6508 Prev_Use := Cur_Use;
6510 -- Most common case: redundant clause in body,
6511 -- original clause in spec. Current scope is spec entity.
6516 Unit (Library_Unit (Cunit (Current_Sem_Unit))))
6518 Redundant := Cur_Use;
6522 -- The new clause may appear in an unrelated unit, when
6523 -- the parents of a generic are being installed prior to
6524 -- instantiation. In this case there must be no warning.
6525 -- We detect this case by checking whether the current top
6526 -- of the stack is related to the current compilation.
6528 Scop := Current_Scope;
6529 while Present (Scop)
6530 and then Scop /= Standard_Standard
6532 if Is_Compilation_Unit (Scop)
6533 and then not Is_Child_Unit (Scop)
6537 elsif Scop = Cunit_Entity (Current_Sem_Unit) then
6541 Scop := Scope (Scop);
6544 Redundant := Cur_Use;
6548 elsif New_Unit = Current_Sem_Unit then
6549 Redundant := Clause;
6550 Prev_Use := Cur_Use;
6553 -- Neither is the current unit, so they appear in parent or
6554 -- sibling units. Warning will be emitted elsewhere.
6560 elsif Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Declaration
6561 and then Present (Parent_Spec (Unit (Cunit (Current_Sem_Unit))))
6563 -- Use_clause is in child unit of current unit, and the child unit
6564 -- appears in the context of the body of the parent, so it has been
6565 -- installed first, even though it is the redundant one. Depending on
6566 -- their placement in the context, the visible or the private parts
6567 -- of the two units, either might appear as redundant, but the
6568 -- message has to be on the current unit.
6570 if Get_Source_Unit (Cur_Use) = Current_Sem_Unit then
6571 Redundant := Cur_Use;
6574 Redundant := Clause;
6575 Prev_Use := Cur_Use;
6578 -- If the new use clause appears in the private part of a parent unit
6579 -- it may appear to be redundant w.r.t. a use clause in a child unit,
6580 -- but the previous use clause was needed in the visible part of the
6581 -- child, and no warning should be emitted.
6583 if Nkind (Parent (Decl)) = N_Package_Specification
6585 List_Containing (Decl) = Private_Declarations (Parent (Decl))
6588 Par : constant Entity_Id := Defining_Entity (Parent (Decl));
6589 Spec : constant Node_Id :=
6590 Specification (Unit (Cunit (Current_Sem_Unit)));
6593 if Is_Compilation_Unit (Par)
6594 and then Par /= Cunit_Entity (Current_Sem_Unit)
6595 and then Parent (Cur_Use) = Spec
6597 List_Containing (Cur_Use) = Visible_Declarations (Spec)
6604 -- Finally, if the current use clause is in the context then
6605 -- the clause is redundant when it is nested within the unit.
6607 elsif Nkind (Parent (Cur_Use)) = N_Compilation_Unit
6608 and then Nkind (Parent (Parent (Clause))) /= N_Compilation_Unit
6609 and then Get_Source_Unit (Cur_Use) = Get_Source_Unit (Clause)
6611 Redundant := Clause;
6612 Prev_Use := Cur_Use;
6618 if Present (Redundant) then
6619 Error_Msg_Sloc := Sloc (Prev_Use);
6620 Error_Msg_NE -- CODEFIX
6621 ("& is already use-visible through previous use clause #?",
6622 Redundant, Pack_Name);
6624 end Note_Redundant_Use;
6630 procedure Pop_Scope is
6631 SST : Scope_Stack_Entry renames Scope_Stack.Table (Scope_Stack.Last);
6634 if Debug_Flag_E then
6638 Scope_Suppress := SST.Save_Scope_Suppress;
6639 Local_Suppress_Stack_Top := SST.Save_Local_Suppress_Stack_Top;
6640 Check_Policy_List := SST.Save_Check_Policy_List;
6642 if Debug_Flag_W then
6643 Write_Str ("--> exiting scope: ");
6644 Write_Name (Chars (Current_Scope));
6645 Write_Str (", Depth=");
6646 Write_Int (Int (Scope_Stack.Last));
6650 End_Use_Clauses (SST.First_Use_Clause);
6652 -- If the actions to be wrapped are still there they will get lost
6653 -- causing incomplete code to be generated. It is better to abort in
6654 -- this case (and we do the abort even with assertions off since the
6655 -- penalty is incorrect code generation)
6657 if SST.Actions_To_Be_Wrapped_Before /= No_List
6659 SST.Actions_To_Be_Wrapped_After /= No_List
6664 -- Free last subprogram name if allocated, and pop scope
6666 Free (SST.Last_Subprogram_Name);
6667 Scope_Stack.Decrement_Last;
6674 procedure Push_Scope (S : Entity_Id) is
6678 if Ekind (S) = E_Void then
6681 -- Set scope depth if not a non-concurrent type, and we have not yet set
6682 -- the scope depth. This means that we have the first occurrence of the
6683 -- scope, and this is where the depth is set.
6685 elsif (not Is_Type (S) or else Is_Concurrent_Type (S))
6686 and then not Scope_Depth_Set (S)
6688 if S = Standard_Standard then
6689 Set_Scope_Depth_Value (S, Uint_0);
6691 elsif Is_Child_Unit (S) then
6692 Set_Scope_Depth_Value (S, Uint_1);
6694 elsif not Is_Record_Type (Current_Scope) then
6695 if Ekind (S) = E_Loop then
6696 Set_Scope_Depth_Value (S, Scope_Depth (Current_Scope));
6698 Set_Scope_Depth_Value (S, Scope_Depth (Current_Scope) + 1);
6703 Scope_Stack.Increment_Last;
6706 SST : Scope_Stack_Entry renames Scope_Stack.Table (Scope_Stack.Last);
6710 SST.Save_Scope_Suppress := Scope_Suppress;
6711 SST.Save_Local_Suppress_Stack_Top := Local_Suppress_Stack_Top;
6712 SST.Save_Check_Policy_List := Check_Policy_List;
6714 if Scope_Stack.Last > Scope_Stack.First then
6715 SST.Component_Alignment_Default := Scope_Stack.Table
6716 (Scope_Stack.Last - 1).
6717 Component_Alignment_Default;
6720 SST.Last_Subprogram_Name := null;
6721 SST.Is_Transient := False;
6722 SST.Node_To_Be_Wrapped := Empty;
6723 SST.Pending_Freeze_Actions := No_List;
6724 SST.Actions_To_Be_Wrapped_Before := No_List;
6725 SST.Actions_To_Be_Wrapped_After := No_List;
6726 SST.First_Use_Clause := Empty;
6727 SST.Is_Active_Stack_Base := False;
6728 SST.Previous_Visibility := False;
6731 if Debug_Flag_W then
6732 Write_Str ("--> new scope: ");
6733 Write_Name (Chars (Current_Scope));
6734 Write_Str (", Id=");
6735 Write_Int (Int (Current_Scope));
6736 Write_Str (", Depth=");
6737 Write_Int (Int (Scope_Stack.Last));
6741 -- Deal with copying flags from the previous scope to this one. This is
6742 -- not necessary if either scope is standard, or if the new scope is a
6745 if S /= Standard_Standard
6746 and then Scope (S) /= Standard_Standard
6747 and then not Is_Child_Unit (S)
6751 if Nkind (E) not in N_Entity then
6755 -- Copy categorization flags from Scope (S) to S, this is not done
6756 -- when Scope (S) is Standard_Standard since propagation is from
6757 -- library unit entity inwards. Copy other relevant attributes as
6758 -- well (Discard_Names in particular).
6760 -- We only propagate inwards for library level entities,
6761 -- inner level subprograms do not inherit the categorization.
6763 if Is_Library_Level_Entity (S) then
6764 Set_Is_Preelaborated (S, Is_Preelaborated (E));
6765 Set_Is_Shared_Passive (S, Is_Shared_Passive (E));
6766 Set_Discard_Names (S, Discard_Names (E));
6767 Set_Suppress_Value_Tracking_On_Call
6768 (S, Suppress_Value_Tracking_On_Call (E));
6769 Set_Categorization_From_Scope (E => S, Scop => E);
6774 ---------------------
6775 -- Premature_Usage --
6776 ---------------------
6778 procedure Premature_Usage (N : Node_Id) is
6779 Kind : constant Node_Kind := Nkind (Parent (Entity (N)));
6780 E : Entity_Id := Entity (N);
6783 -- Within an instance, the analysis of the actual for a formal object
6784 -- does not see the name of the object itself. This is significant only
6785 -- if the object is an aggregate, where its analysis does not do any
6786 -- name resolution on component associations. (see 4717-008). In such a
6787 -- case, look for the visible homonym on the chain.
6790 and then Present (Homonym (E))
6795 and then not In_Open_Scopes (Scope (E))
6802 Set_Etype (N, Etype (E));
6807 if Kind = N_Component_Declaration then
6809 ("component&! cannot be used before end of record declaration", N);
6811 elsif Kind = N_Parameter_Specification then
6813 ("formal parameter&! cannot be used before end of specification",
6816 elsif Kind = N_Discriminant_Specification then
6818 ("discriminant&! cannot be used before end of discriminant part",
6821 elsif Kind = N_Procedure_Specification
6822 or else Kind = N_Function_Specification
6825 ("subprogram&! cannot be used before end of its declaration",
6828 elsif Kind = N_Full_Type_Declaration then
6830 ("type& cannot be used before end of its declaration!", N);
6834 ("object& cannot be used before end of its declaration!", N);
6836 end Premature_Usage;
6838 ------------------------
6839 -- Present_System_Aux --
6840 ------------------------
6842 function Present_System_Aux (N : Node_Id := Empty) return Boolean is
6844 Aux_Name : Unit_Name_Type;
6845 Unum : Unit_Number_Type;
6850 function Find_System (C_Unit : Node_Id) return Entity_Id;
6851 -- Scan context clause of compilation unit to find with_clause
6858 function Find_System (C_Unit : Node_Id) return Entity_Id is
6859 With_Clause : Node_Id;
6862 With_Clause := First (Context_Items (C_Unit));
6863 while Present (With_Clause) loop
6864 if (Nkind (With_Clause) = N_With_Clause
6865 and then Chars (Name (With_Clause)) = Name_System)
6866 and then Comes_From_Source (With_Clause)
6877 -- Start of processing for Present_System_Aux
6880 -- The child unit may have been loaded and analyzed already
6882 if Present (System_Aux_Id) then
6885 -- If no previous pragma for System.Aux, nothing to load
6887 elsif No (System_Extend_Unit) then
6890 -- Use the unit name given in the pragma to retrieve the unit.
6891 -- Verify that System itself appears in the context clause of the
6892 -- current compilation. If System is not present, an error will
6893 -- have been reported already.
6896 With_Sys := Find_System (Cunit (Current_Sem_Unit));
6898 The_Unit := Unit (Cunit (Current_Sem_Unit));
6902 (Nkind (The_Unit) = N_Package_Body
6903 or else (Nkind (The_Unit) = N_Subprogram_Body
6905 not Acts_As_Spec (Cunit (Current_Sem_Unit))))
6907 With_Sys := Find_System (Library_Unit (Cunit (Current_Sem_Unit)));
6911 and then Present (N)
6913 -- If we are compiling a subunit, we need to examine its
6914 -- context as well (Current_Sem_Unit is the parent unit);
6916 The_Unit := Parent (N);
6917 while Nkind (The_Unit) /= N_Compilation_Unit loop
6918 The_Unit := Parent (The_Unit);
6921 if Nkind (Unit (The_Unit)) = N_Subunit then
6922 With_Sys := Find_System (The_Unit);
6926 if No (With_Sys) then
6930 Loc := Sloc (With_Sys);
6931 Get_Name_String (Chars (Expression (System_Extend_Unit)));
6932 Name_Buffer (8 .. Name_Len + 7) := Name_Buffer (1 .. Name_Len);
6933 Name_Buffer (1 .. 7) := "system.";
6934 Name_Buffer (Name_Len + 8) := '%';
6935 Name_Buffer (Name_Len + 9) := 's';
6936 Name_Len := Name_Len + 9;
6937 Aux_Name := Name_Find;
6941 (Load_Name => Aux_Name,
6944 Error_Node => With_Sys);
6946 if Unum /= No_Unit then
6947 Semantics (Cunit (Unum));
6949 Defining_Entity (Specification (Unit (Cunit (Unum))));
6952 Make_With_Clause (Loc,
6954 Make_Expanded_Name (Loc,
6955 Chars => Chars (System_Aux_Id),
6956 Prefix => New_Reference_To (Scope (System_Aux_Id), Loc),
6957 Selector_Name => New_Reference_To (System_Aux_Id, Loc)));
6959 Set_Entity (Name (Withn), System_Aux_Id);
6961 Set_Library_Unit (Withn, Cunit (Unum));
6962 Set_Corresponding_Spec (Withn, System_Aux_Id);
6963 Set_First_Name (Withn, True);
6964 Set_Implicit_With (Withn, True);
6966 Insert_After (With_Sys, Withn);
6967 Mark_Rewrite_Insertion (Withn);
6968 Set_Context_Installed (Withn);
6972 -- Here if unit load failed
6975 Error_Msg_Name_1 := Name_System;
6976 Error_Msg_Name_2 := Chars (Expression (System_Extend_Unit));
6978 ("extension package `%.%` does not exist",
6979 Opt.System_Extend_Unit);
6983 end Present_System_Aux;
6985 -------------------------
6986 -- Restore_Scope_Stack --
6987 -------------------------
6989 procedure Restore_Scope_Stack (Handle_Use : Boolean := True) is
6992 Comp_Unit : Node_Id;
6993 In_Child : Boolean := False;
6994 Full_Vis : Boolean := True;
6995 SS_Last : constant Int := Scope_Stack.Last;
6998 -- Restore visibility of previous scope stack, if any
7000 for J in reverse 0 .. Scope_Stack.Last loop
7001 exit when Scope_Stack.Table (J).Entity = Standard_Standard
7002 or else No (Scope_Stack.Table (J).Entity);
7004 S := Scope_Stack.Table (J).Entity;
7006 if not Is_Hidden_Open_Scope (S) then
7008 -- If the parent scope is hidden, its entities are hidden as
7009 -- well, unless the entity is the instantiation currently
7012 if not Is_Hidden_Open_Scope (Scope (S))
7013 or else not Analyzed (Parent (S))
7014 or else Scope (S) = Standard_Standard
7016 Set_Is_Immediately_Visible (S, True);
7019 E := First_Entity (S);
7020 while Present (E) loop
7021 if Is_Child_Unit (E) then
7022 if not From_With_Type (E) then
7023 Set_Is_Immediately_Visible (E,
7024 Is_Visible_Child_Unit (E) or else In_Open_Scopes (E));
7028 (Nkind (Parent (E)) = N_Defining_Program_Unit_Name
7030 Nkind (Parent (Parent (E))) = N_Package_Specification);
7031 Set_Is_Immediately_Visible (E,
7032 Limited_View_Installed (Parent (Parent (E))));
7035 Set_Is_Immediately_Visible (E, True);
7041 and then Is_Package_Or_Generic_Package (S)
7043 -- We are in the visible part of the package scope
7045 exit when E = First_Private_Entity (S);
7049 -- The visibility of child units (siblings of current compilation)
7050 -- must be restored in any case. Their declarations may appear
7051 -- after the private part of the parent.
7053 if not Full_Vis then
7054 while Present (E) loop
7055 if Is_Child_Unit (E) then
7056 Set_Is_Immediately_Visible (E,
7057 Is_Visible_Child_Unit (E) or else In_Open_Scopes (E));
7065 if Is_Child_Unit (S)
7066 and not In_Child -- check only for current unit
7070 -- Restore visibility of parents according to whether the child
7071 -- is private and whether we are in its visible part.
7073 Comp_Unit := Parent (Unit_Declaration_Node (S));
7075 if Nkind (Comp_Unit) = N_Compilation_Unit
7076 and then Private_Present (Comp_Unit)
7080 elsif Is_Package_Or_Generic_Package (S)
7081 and then (In_Private_Part (S) or else In_Package_Body (S))
7085 -- if S is the scope of some instance (which has already been
7086 -- seen on the stack) it does not affect the visibility of
7089 elsif Is_Hidden_Open_Scope (S) then
7092 elsif (Ekind (S) = E_Procedure
7093 or else Ekind (S) = E_Function)
7094 and then Has_Completion (S)
7105 if SS_Last >= Scope_Stack.First
7106 and then Scope_Stack.Table (SS_Last).Entity /= Standard_Standard
7109 Install_Use_Clauses (Scope_Stack.Table (SS_Last).First_Use_Clause);
7111 end Restore_Scope_Stack;
7113 ----------------------
7114 -- Save_Scope_Stack --
7115 ----------------------
7117 procedure Save_Scope_Stack (Handle_Use : Boolean := True) is
7120 SS_Last : constant Int := Scope_Stack.Last;
7123 if SS_Last >= Scope_Stack.First
7124 and then Scope_Stack.Table (SS_Last).Entity /= Standard_Standard
7127 End_Use_Clauses (Scope_Stack.Table (SS_Last).First_Use_Clause);
7130 -- If the call is from within a compilation unit, as when called from
7131 -- Rtsfind, make current entries in scope stack invisible while we
7132 -- analyze the new unit.
7134 for J in reverse 0 .. SS_Last loop
7135 exit when Scope_Stack.Table (J).Entity = Standard_Standard
7136 or else No (Scope_Stack.Table (J).Entity);
7138 S := Scope_Stack.Table (J).Entity;
7139 Set_Is_Immediately_Visible (S, False);
7141 E := First_Entity (S);
7142 while Present (E) loop
7143 Set_Is_Immediately_Visible (E, False);
7149 end Save_Scope_Stack;
7155 procedure Set_Use (L : List_Id) is
7157 Pack_Name : Node_Id;
7164 while Present (Decl) loop
7165 if Nkind (Decl) = N_Use_Package_Clause then
7166 Chain_Use_Clause (Decl);
7168 Pack_Name := First (Names (Decl));
7169 while Present (Pack_Name) loop
7170 Pack := Entity (Pack_Name);
7172 if Ekind (Pack) = E_Package
7173 and then Applicable_Use (Pack_Name)
7175 Use_One_Package (Pack, Decl);
7181 elsif Nkind (Decl) = N_Use_Type_Clause then
7182 Chain_Use_Clause (Decl);
7184 Id := First (Subtype_Marks (Decl));
7185 while Present (Id) loop
7186 if Entity (Id) /= Any_Type then
7199 ---------------------
7200 -- Use_One_Package --
7201 ---------------------
7203 procedure Use_One_Package (P : Entity_Id; N : Node_Id) is
7206 Current_Instance : Entity_Id := Empty;
7208 Private_With_OK : Boolean := False;
7211 if Ekind (P) /= E_Package then
7216 Set_Current_Use_Clause (P, N);
7218 -- Ada 2005 (AI-50217): Check restriction
7220 if From_With_Type (P) then
7221 Error_Msg_N ("limited withed package cannot appear in use clause", N);
7224 -- Find enclosing instance, if any
7227 Current_Instance := Current_Scope;
7228 while not Is_Generic_Instance (Current_Instance) loop
7229 Current_Instance := Scope (Current_Instance);
7232 if No (Hidden_By_Use_Clause (N)) then
7233 Set_Hidden_By_Use_Clause (N, New_Elmt_List);
7237 -- If unit is a package renaming, indicate that the renamed
7238 -- package is also in use (the flags on both entities must
7239 -- remain consistent, and a subsequent use of either of them
7240 -- should be recognized as redundant).
7242 if Present (Renamed_Object (P)) then
7243 Set_In_Use (Renamed_Object (P));
7244 Set_Current_Use_Clause (Renamed_Object (P), N);
7245 Real_P := Renamed_Object (P);
7250 -- Ada 2005 (AI-262): Check the use_clause of a private withed package
7251 -- found in the private part of a package specification
7253 if In_Private_Part (Current_Scope)
7254 and then Has_Private_With (P)
7255 and then Is_Child_Unit (Current_Scope)
7256 and then Is_Child_Unit (P)
7257 and then Is_Ancestor_Package (Scope (Current_Scope), P)
7259 Private_With_OK := True;
7262 -- Loop through entities in one package making them potentially
7265 Id := First_Entity (P);
7267 and then (Id /= First_Private_Entity (P)
7268 or else Private_With_OK) -- Ada 2005 (AI-262)
7270 Prev := Current_Entity (Id);
7271 while Present (Prev) loop
7272 if Is_Immediately_Visible (Prev)
7273 and then (not Is_Overloadable (Prev)
7274 or else not Is_Overloadable (Id)
7275 or else (Type_Conformant (Id, Prev)))
7277 if No (Current_Instance) then
7279 -- Potentially use-visible entity remains hidden
7281 goto Next_Usable_Entity;
7283 -- A use clause within an instance hides outer global entities,
7284 -- which are not used to resolve local entities in the
7285 -- instance. Note that the predefined entities in Standard
7286 -- could not have been hidden in the generic by a use clause,
7287 -- and therefore remain visible. Other compilation units whose
7288 -- entities appear in Standard must be hidden in an instance.
7290 -- To determine whether an entity is external to the instance
7291 -- we compare the scope depth of its scope with that of the
7292 -- current instance. However, a generic actual of a subprogram
7293 -- instance is declared in the wrapper package but will not be
7294 -- hidden by a use-visible entity. similarly, an entity that is
7295 -- declared in an enclosing instance will not be hidden by an
7296 -- an entity declared in a generic actual, which can only have
7297 -- been use-visible in the generic and will not have hidden the
7298 -- entity in the generic parent.
7300 -- If Id is called Standard, the predefined package with the
7301 -- same name is in the homonym chain. It has to be ignored
7302 -- because it has no defined scope (being the only entity in
7303 -- the system with this mandated behavior).
7305 elsif not Is_Hidden (Id)
7306 and then Present (Scope (Prev))
7307 and then not Is_Wrapper_Package (Scope (Prev))
7308 and then Scope_Depth (Scope (Prev)) <
7309 Scope_Depth (Current_Instance)
7310 and then (Scope (Prev) /= Standard_Standard
7311 or else Sloc (Prev) > Standard_Location)
7313 if In_Open_Scopes (Scope (Prev))
7314 and then Is_Generic_Instance (Scope (Prev))
7315 and then Present (Associated_Formal_Package (P))
7320 Set_Is_Potentially_Use_Visible (Id);
7321 Set_Is_Immediately_Visible (Prev, False);
7322 Append_Elmt (Prev, Hidden_By_Use_Clause (N));
7326 -- A user-defined operator is not use-visible if the predefined
7327 -- operator for the type is immediately visible, which is the case
7328 -- if the type of the operand is in an open scope. This does not
7329 -- apply to user-defined operators that have operands of different
7330 -- types, because the predefined mixed mode operations (multiply
7331 -- and divide) apply to universal types and do not hide anything.
7333 elsif Ekind (Prev) = E_Operator
7334 and then Operator_Matches_Spec (Prev, Id)
7335 and then In_Open_Scopes
7336 (Scope (Base_Type (Etype (First_Formal (Id)))))
7337 and then (No (Next_Formal (First_Formal (Id)))
7338 or else Etype (First_Formal (Id))
7339 = Etype (Next_Formal (First_Formal (Id)))
7340 or else Chars (Prev) = Name_Op_Expon)
7342 goto Next_Usable_Entity;
7344 -- In an instance, two homonyms may become use_visible through the
7345 -- actuals of distinct formal packages. In the generic, only the
7346 -- current one would have been visible, so make the other one
7349 elsif Present (Current_Instance)
7350 and then Is_Potentially_Use_Visible (Prev)
7351 and then not Is_Overloadable (Prev)
7352 and then Scope (Id) /= Scope (Prev)
7353 and then Used_As_Generic_Actual (Scope (Prev))
7354 and then Used_As_Generic_Actual (Scope (Id))
7355 and then not In_Same_List (Current_Use_Clause (Scope (Prev)),
7356 Current_Use_Clause (Scope (Id)))
7358 Set_Is_Potentially_Use_Visible (Prev, False);
7359 Append_Elmt (Prev, Hidden_By_Use_Clause (N));
7362 Prev := Homonym (Prev);
7365 -- On exit, we know entity is not hidden, unless it is private
7367 if not Is_Hidden (Id)
7368 and then ((not Is_Child_Unit (Id))
7369 or else Is_Visible_Child_Unit (Id))
7371 Set_Is_Potentially_Use_Visible (Id);
7373 if Is_Private_Type (Id)
7374 and then Present (Full_View (Id))
7376 Set_Is_Potentially_Use_Visible (Full_View (Id));
7380 <<Next_Usable_Entity>>
7384 -- Child units are also made use-visible by a use clause, but they may
7385 -- appear after all visible declarations in the parent entity list.
7387 while Present (Id) loop
7388 if Is_Child_Unit (Id)
7389 and then Is_Visible_Child_Unit (Id)
7391 Set_Is_Potentially_Use_Visible (Id);
7397 if Chars (Real_P) = Name_System
7398 and then Scope (Real_P) = Standard_Standard
7399 and then Present_System_Aux (N)
7401 Use_One_Package (System_Aux_Id, N);
7404 end Use_One_Package;
7410 procedure Use_One_Type (Id : Node_Id) is
7412 Is_Known_Used : Boolean;
7416 function Spec_Reloaded_For_Body return Boolean;
7417 -- Determine whether the compilation unit is a package body and the use
7418 -- type clause is in the spec of the same package. Even though the spec
7419 -- was analyzed first, its context is reloaded when analysing the body.
7421 ----------------------------
7422 -- Spec_Reloaded_For_Body --
7423 ----------------------------
7425 function Spec_Reloaded_For_Body return Boolean is
7427 if Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Body then
7429 Spec : constant Node_Id :=
7430 Parent (List_Containing (Parent (Id)));
7433 Nkind (Spec) = N_Package_Specification
7434 and then Corresponding_Body (Parent (Spec)) =
7435 Cunit_Entity (Current_Sem_Unit);
7440 end Spec_Reloaded_For_Body;
7442 -- Start of processing for Use_One_Type;
7445 -- It is the type determined by the subtype mark (8.4(8)) whose
7446 -- operations become potentially use-visible.
7448 T := Base_Type (Entity (Id));
7450 -- Either the type itself is used, the package where it is declared
7451 -- is in use or the entity is declared in the current package, thus
7456 or else In_Use (Scope (T))
7457 or else Scope (T) = Current_Scope;
7459 Set_Redundant_Use (Id,
7460 Is_Known_Used or else Is_Potentially_Use_Visible (T));
7462 if Ekind (T) = E_Incomplete_Type then
7463 Error_Msg_N ("premature usage of incomplete type", Id);
7465 elsif In_Open_Scopes (Scope (T)) then
7468 -- A limited view cannot appear in a use_type clause. However, an access
7469 -- type whose designated type is limited has the flag but is not itself
7470 -- a limited view unless we only have a limited view of its enclosing
7473 elsif From_With_Type (T)
7474 and then From_With_Type (Scope (T))
7477 ("incomplete type from limited view "
7478 & "cannot appear in use clause", Id);
7480 -- If the subtype mark designates a subtype in a different package,
7481 -- we have to check that the parent type is visible, otherwise the
7482 -- use type clause is a noop. Not clear how to do that???
7484 elsif not Redundant_Use (Id) then
7487 -- If T is tagged, primitive operators on class-wide operands
7488 -- are also available.
7490 if Is_Tagged_Type (T) then
7491 Set_In_Use (Class_Wide_Type (T));
7494 Set_Current_Use_Clause (T, Parent (Id));
7495 Op_List := Collect_Primitive_Operations (T);
7497 Elmt := First_Elmt (Op_List);
7498 while Present (Elmt) loop
7499 if (Nkind (Node (Elmt)) = N_Defining_Operator_Symbol
7500 or else Chars (Node (Elmt)) in Any_Operator_Name)
7501 and then not Is_Hidden (Node (Elmt))
7503 Set_Is_Potentially_Use_Visible (Node (Elmt));
7510 -- If warning on redundant constructs, check for unnecessary WITH
7512 if Warn_On_Redundant_Constructs
7513 and then Is_Known_Used
7515 -- with P; with P; use P;
7516 -- package P is package X is package body X is
7517 -- type T ... use P.T;
7519 -- The compilation unit is the body of X. GNAT first compiles the
7520 -- spec of X, then proceeds to the body. At that point P is marked
7521 -- as use visible. The analysis then reinstalls the spec along with
7522 -- its context. The use clause P.T is now recognized as redundant,
7523 -- but in the wrong context. Do not emit a warning in such cases.
7524 -- Do not emit a warning either if we are in an instance, there is
7525 -- no redundancy between an outer use_clause and one that appears
7526 -- within the generic.
7528 and then not Spec_Reloaded_For_Body
7529 and then not In_Instance
7531 -- The type already has a use clause
7535 -- Case where we know the current use clause for the type
7537 if Present (Current_Use_Clause (T)) then
7538 Use_Clause_Known : declare
7539 Clause1 : constant Node_Id := Parent (Id);
7540 Clause2 : constant Node_Id := Current_Use_Clause (T);
7547 function Entity_Of_Unit (U : Node_Id) return Entity_Id;
7548 -- Return the appropriate entity for determining which unit
7549 -- has a deeper scope: the defining entity for U, unless U
7550 -- is a package instance, in which case we retrieve the
7551 -- entity of the instance spec.
7553 --------------------
7554 -- Entity_Of_Unit --
7555 --------------------
7557 function Entity_Of_Unit (U : Node_Id) return Entity_Id is
7559 if Nkind (U) = N_Package_Instantiation
7560 and then Analyzed (U)
7562 return Defining_Entity (Instance_Spec (U));
7564 return Defining_Entity (U);
7568 -- Start of processing for Use_Clause_Known
7571 -- If both current use type clause and the use type clause
7572 -- for the type are at the compilation unit level, one of
7573 -- the units must be an ancestor of the other, and the
7574 -- warning belongs on the descendant.
7576 if Nkind (Parent (Clause1)) = N_Compilation_Unit
7578 Nkind (Parent (Clause2)) = N_Compilation_Unit
7581 -- If the unit is a subprogram body that acts as spec,
7582 -- the context clause is shared with the constructed
7583 -- subprogram spec. Clearly there is no redundancy.
7585 if Clause1 = Clause2 then
7589 Unit1 := Unit (Parent (Clause1));
7590 Unit2 := Unit (Parent (Clause2));
7592 -- If both clauses are on same unit, or one is the body
7593 -- of the other, or one of them is in a subunit, report
7594 -- redundancy on the later one.
7596 if Unit1 = Unit2 then
7597 Error_Msg_Sloc := Sloc (Current_Use_Clause (T));
7598 Error_Msg_NE -- CODEFIX
7599 ("& is already use-visible through previous "
7600 & "use_type_clause #?", Clause1, T);
7603 elsif Nkind (Unit1) = N_Subunit then
7604 Error_Msg_Sloc := Sloc (Current_Use_Clause (T));
7605 Error_Msg_NE -- CODEFIX
7606 ("& is already use-visible through previous "
7607 & "use_type_clause #?", Clause1, T);
7610 elsif Nkind_In (Unit2, N_Package_Body, N_Subprogram_Body)
7611 and then Nkind (Unit1) /= Nkind (Unit2)
7612 and then Nkind (Unit1) /= N_Subunit
7614 Error_Msg_Sloc := Sloc (Clause1);
7615 Error_Msg_NE -- CODEFIX
7616 ("& is already use-visible through previous "
7617 & "use_type_clause #?", Current_Use_Clause (T), T);
7621 -- There is a redundant use type clause in a child unit.
7622 -- Determine which of the units is more deeply nested.
7623 -- If a unit is a package instance, retrieve the entity
7624 -- and its scope from the instance spec.
7626 Ent1 := Entity_Of_Unit (Unit1);
7627 Ent2 := Entity_Of_Unit (Unit2);
7629 if Scope (Ent2) = Standard_Standard then
7630 Error_Msg_Sloc := Sloc (Current_Use_Clause (T));
7633 elsif Scope (Ent1) = Standard_Standard then
7634 Error_Msg_Sloc := Sloc (Id);
7637 -- If both units are child units, we determine which one
7638 -- is the descendant by the scope distance to the
7639 -- ultimate parent unit.
7649 and then Present (S2)
7650 and then S1 /= Standard_Standard
7651 and then S2 /= Standard_Standard
7657 if S1 = Standard_Standard then
7658 Error_Msg_Sloc := Sloc (Id);
7661 Error_Msg_Sloc := Sloc (Current_Use_Clause (T));
7667 Error_Msg_NE -- CODEFIX
7668 ("& is already use-visible through previous "
7669 & "use_type_clause #?", Err_No, Id);
7671 -- Case where current use type clause and the use type
7672 -- clause for the type are not both at the compilation unit
7673 -- level. In this case we don't have location information.
7676 Error_Msg_NE -- CODEFIX
7677 ("& is already use-visible through previous "
7678 & "use type clause?", Id, T);
7680 end Use_Clause_Known;
7682 -- Here if Current_Use_Clause is not set for T, another case
7683 -- where we do not have the location information available.
7686 Error_Msg_NE -- CODEFIX
7687 ("& is already use-visible through previous "
7688 & "use type clause?", Id, T);
7691 -- The package where T is declared is already used
7693 elsif In_Use (Scope (T)) then
7694 Error_Msg_Sloc := Sloc (Current_Use_Clause (Scope (T)));
7695 Error_Msg_NE -- CODEFIX
7696 ("& is already use-visible through package use clause #?",
7699 -- The current scope is the package where T is declared
7702 Error_Msg_Node_2 := Scope (T);
7703 Error_Msg_NE -- CODEFIX
7704 ("& is already use-visible inside package &?", Id, T);
7713 procedure Write_Info is
7714 Id : Entity_Id := First_Entity (Current_Scope);
7717 -- No point in dumping standard entities
7719 if Current_Scope = Standard_Standard then
7723 Write_Str ("========================================================");
7725 Write_Str (" Defined Entities in ");
7726 Write_Name (Chars (Current_Scope));
7728 Write_Str ("========================================================");
7732 Write_Str ("-- none --");
7736 while Present (Id) loop
7737 Write_Entity_Info (Id, " ");
7742 if Scope (Current_Scope) = Standard_Standard then
7744 -- Print information on the current unit itself
7746 Write_Entity_Info (Current_Scope, " ");
7759 for J in reverse 1 .. Scope_Stack.Last loop
7760 S := Scope_Stack.Table (J).Entity;
7761 Write_Int (Int (S));
7762 Write_Str (" === ");
7763 Write_Name (Chars (S));
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