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 -- Selected component is known to be expanded name. Verify legality of
458 -- selector given the scope denoted by prefix.
460 function Find_Renamed_Entity
464 Is_Actual : Boolean := False) return Entity_Id;
465 -- Find the renamed entity that corresponds to the given parameter profile
466 -- in a subprogram renaming declaration. The renamed entity may be an
467 -- operator, a subprogram, an entry, or a protected operation. Is_Actual
468 -- indicates that the renaming is the one generated for an actual subpro-
469 -- gram in an instance, for which special visibility checks apply.
471 function Has_Implicit_Operator (N : Node_Id) return Boolean;
472 -- N is an expanded name whose selector is an operator name (e.g. P."+").
473 -- declarative part contains an implicit declaration of an operator if it
474 -- has a declaration of a type to which one of the predefined operators
475 -- apply. The existence of this routine is an implementation artifact. A
476 -- more straightforward but more space-consuming choice would be to make
477 -- all inherited operators explicit in the symbol table.
479 procedure Inherit_Renamed_Profile (New_S : Entity_Id; Old_S : Entity_Id);
480 -- A subprogram defined by a renaming declaration inherits the parameter
481 -- profile of the renamed entity. The subtypes given in the subprogram
482 -- specification are discarded and replaced with those of the renamed
483 -- subprogram, which are then used to recheck the default values.
485 function Is_Appropriate_For_Record (T : Entity_Id) return Boolean;
486 -- Prefix is appropriate for record if it is of a record type, or an access
489 function Is_Appropriate_For_Entry_Prefix (T : Entity_Id) return Boolean;
490 -- True if it is of a task type, a protected type, or else an access to one
493 procedure Note_Redundant_Use (Clause : Node_Id);
494 -- Mark the name in a use clause as redundant if the corresponding entity
495 -- is already use-visible. Emit a warning if the use clause comes from
496 -- source and the proper warnings are enabled.
498 procedure Premature_Usage (N : Node_Id);
499 -- Diagnose usage of an entity before it is visible
501 procedure Use_One_Package (P : Entity_Id; N : Node_Id);
502 -- Make visible entities declared in package P potentially use-visible
503 -- in the current context. Also used in the analysis of subunits, when
504 -- re-installing use clauses of parent units. N is the use_clause that
505 -- names P (and possibly other packages).
507 procedure Use_One_Type (Id : Node_Id);
508 -- Id is the subtype mark from a use type clause. This procedure makes
509 -- the primitive operators of the type potentially use-visible.
511 procedure Write_Info;
512 -- Write debugging information on entities declared in current scope
514 procedure Write_Scopes;
515 pragma Warnings (Off, Write_Scopes);
516 -- Debugging information: dump all entities on scope stack
518 --------------------------------
519 -- Analyze_Exception_Renaming --
520 --------------------------------
522 -- The language only allows a single identifier, but the tree holds an
523 -- identifier list. The parser has already issued an error message if
524 -- there is more than one element in the list.
526 procedure Analyze_Exception_Renaming (N : Node_Id) is
527 Id : constant Node_Id := Defining_Identifier (N);
528 Nam : constant Node_Id := Name (N);
534 Set_Ekind (Id, E_Exception);
535 Set_Exception_Code (Id, Uint_0);
536 Set_Etype (Id, Standard_Exception_Type);
537 Set_Is_Pure (Id, Is_Pure (Current_Scope));
539 if not Is_Entity_Name (Nam) or else
540 Ekind (Entity (Nam)) /= E_Exception
542 Error_Msg_N ("invalid exception name in renaming", Nam);
544 if Present (Renamed_Object (Entity (Nam))) then
545 Set_Renamed_Object (Id, Renamed_Object (Entity (Nam)));
547 Set_Renamed_Object (Id, Entity (Nam));
550 end Analyze_Exception_Renaming;
552 ---------------------------
553 -- Analyze_Expanded_Name --
554 ---------------------------
556 procedure Analyze_Expanded_Name (N : Node_Id) is
558 -- If the entity pointer is already set, this is an internal node, or a
559 -- node that is analyzed more than once, after a tree modification. In
560 -- such a case there is no resolution to perform, just set the type. For
561 -- completeness, analyze prefix as well.
563 if Present (Entity (N)) then
564 if Is_Type (Entity (N)) then
565 Set_Etype (N, Entity (N));
567 Set_Etype (N, Etype (Entity (N)));
570 Analyze (Prefix (N));
573 Find_Expanded_Name (N);
575 end Analyze_Expanded_Name;
577 ---------------------------------------
578 -- Analyze_Generic_Function_Renaming --
579 ---------------------------------------
581 procedure Analyze_Generic_Function_Renaming (N : Node_Id) is
583 Analyze_Generic_Renaming (N, E_Generic_Function);
584 end Analyze_Generic_Function_Renaming;
586 --------------------------------------
587 -- Analyze_Generic_Package_Renaming --
588 --------------------------------------
590 procedure Analyze_Generic_Package_Renaming (N : Node_Id) is
592 -- Apply the Text_IO Kludge here, since we may be renaming one of the
593 -- subpackages of Text_IO, then join common routine.
595 Text_IO_Kludge (Name (N));
597 Analyze_Generic_Renaming (N, E_Generic_Package);
598 end Analyze_Generic_Package_Renaming;
600 ----------------------------------------
601 -- Analyze_Generic_Procedure_Renaming --
602 ----------------------------------------
604 procedure Analyze_Generic_Procedure_Renaming (N : Node_Id) is
606 Analyze_Generic_Renaming (N, E_Generic_Procedure);
607 end Analyze_Generic_Procedure_Renaming;
609 ------------------------------
610 -- Analyze_Generic_Renaming --
611 ------------------------------
613 procedure Analyze_Generic_Renaming
617 New_P : constant Entity_Id := Defining_Entity (N);
619 Inst : Boolean := False; -- prevent junk warning
622 if Name (N) = Error then
626 Generate_Definition (New_P);
628 if Current_Scope /= Standard_Standard then
629 Set_Is_Pure (New_P, Is_Pure (Current_Scope));
632 if Nkind (Name (N)) = N_Selected_Component then
633 Check_Generic_Child_Unit (Name (N), Inst);
638 if not Is_Entity_Name (Name (N)) then
639 Error_Msg_N ("expect entity name in renaming declaration", Name (N));
642 Old_P := Entity (Name (N));
646 Set_Ekind (New_P, K);
648 if Etype (Old_P) = Any_Type then
651 elsif Ekind (Old_P) /= K then
652 Error_Msg_N ("invalid generic unit name", Name (N));
655 if Present (Renamed_Object (Old_P)) then
656 Set_Renamed_Object (New_P, Renamed_Object (Old_P));
658 Set_Renamed_Object (New_P, Old_P);
661 Set_Is_Pure (New_P, Is_Pure (Old_P));
662 Set_Is_Preelaborated (New_P, Is_Preelaborated (Old_P));
664 Set_Etype (New_P, Etype (Old_P));
665 Set_Has_Completion (New_P);
667 if In_Open_Scopes (Old_P) then
668 Error_Msg_N ("within its scope, generic denotes its instance", N);
671 Check_Library_Unit_Renaming (N, Old_P);
673 end Analyze_Generic_Renaming;
675 -----------------------------
676 -- Analyze_Object_Renaming --
677 -----------------------------
679 procedure Analyze_Object_Renaming (N : Node_Id) is
680 Id : constant Entity_Id := Defining_Identifier (N);
682 Nam : constant Node_Id := Name (N);
686 function In_Generic_Scope (E : Entity_Id) return Boolean;
687 -- Determine whether entity E is inside a generic cope
689 ----------------------
690 -- In_Generic_Scope --
691 ----------------------
693 function In_Generic_Scope (E : Entity_Id) return Boolean is
698 while Present (S) and then S /= Standard_Standard loop
699 if Is_Generic_Unit (S) then
707 end In_Generic_Scope;
709 -- Start of processing for Analyze_Object_Renaming
716 Set_Is_Pure (Id, Is_Pure (Current_Scope));
719 -- The renaming of a component that depends on a discriminant requires
720 -- an actual subtype, because in subsequent use of the object Gigi will
721 -- be unable to locate the actual bounds. This explicit step is required
722 -- when the renaming is generated in removing side effects of an
723 -- already-analyzed expression.
725 if Nkind (Nam) = N_Selected_Component
726 and then Analyzed (Nam)
729 Dec := Build_Actual_Subtype_Of_Component (Etype (Nam), Nam);
731 if Present (Dec) then
732 Insert_Action (N, Dec);
733 T := Defining_Identifier (Dec);
737 -- Complete analysis of the subtype mark in any case, for ASIS use
739 if Present (Subtype_Mark (N)) then
740 Find_Type (Subtype_Mark (N));
743 elsif Present (Subtype_Mark (N)) then
744 Find_Type (Subtype_Mark (N));
745 T := Entity (Subtype_Mark (N));
748 if Nkind (Nam) = N_Type_Conversion
749 and then not Is_Tagged_Type (T)
752 ("renaming of conversion only allowed for tagged types", Nam);
757 -- Check that a class-wide object is not being renamed as an object
758 -- of a specific type. The test for access types is needed to exclude
759 -- cases where the renamed object is a dynamically tagged access
760 -- result, such as occurs in certain expansions.
762 if Is_Tagged_Type (T) then
763 Check_Dynamically_Tagged_Expression
769 -- Ada 2005 (AI-230/AI-254): Access renaming
771 else pragma Assert (Present (Access_Definition (N)));
772 T := Access_Definition
774 N => Access_Definition (N));
778 -- Ada 2005 AI05-105: if the declaration has an anonymous access
779 -- type, the renamed object must also have an anonymous type, and
780 -- this is a name resolution rule. This was implicit in the last
781 -- part of the first sentence in 8.5.1.(3/2), and is made explicit
782 -- by this recent AI.
784 if not Is_Overloaded (Nam) then
785 if Ekind (Etype (Nam)) /= Ekind (T) then
787 ("expect anonymous access type in object renaming", N);
794 Typ : Entity_Id := Empty;
795 Seen : Boolean := False;
798 Get_First_Interp (Nam, I, It);
799 while Present (It.Typ) loop
801 -- Renaming is ambiguous if more than one candidate
802 -- interpretation is type-conformant with the context.
804 if Ekind (It.Typ) = Ekind (T) then
805 if Ekind (T) = E_Anonymous_Access_Subprogram_Type
808 (Designated_Type (T), Designated_Type (It.Typ))
814 ("ambiguous expression in renaming", Nam);
817 elsif Ekind (T) = E_Anonymous_Access_Type
819 Covers (Designated_Type (T), Designated_Type (It.Typ))
825 ("ambiguous expression in renaming", Nam);
829 if Covers (T, It.Typ) then
831 Set_Etype (Nam, Typ);
832 Set_Is_Overloaded (Nam, False);
836 Get_Next_Interp (I, It);
843 -- Ada 2005 (AI-231): "In the case where the type is defined by an
844 -- access_definition, the renamed entity shall be of an access-to-
845 -- constant type if and only if the access_definition defines an
846 -- access-to-constant type" ARM 8.5.1(4)
848 if Constant_Present (Access_Definition (N))
849 and then not Is_Access_Constant (Etype (Nam))
851 Error_Msg_N ("(Ada 2005): the renamed object is not "
852 & "access-to-constant (RM 8.5.1(6))", N);
854 elsif not Constant_Present (Access_Definition (N))
855 and then Is_Access_Constant (Etype (Nam))
857 Error_Msg_N ("(Ada 2005): the renamed object is not "
858 & "access-to-variable (RM 8.5.1(6))", N);
861 if Is_Access_Subprogram_Type (Etype (Nam)) then
862 Check_Subtype_Conformant
863 (Designated_Type (T), Designated_Type (Etype (Nam)));
865 elsif not Subtypes_Statically_Match
866 (Designated_Type (T), Designated_Type (Etype (Nam)))
869 ("subtype of renamed object does not statically match", N);
873 -- Special processing for renaming function return object. Some errors
874 -- and warnings are produced only for calls that come from source.
876 if Nkind (Nam) = N_Function_Call then
879 -- Usage is illegal in Ada 83
882 if Comes_From_Source (Nam) then
884 ("(Ada 83) cannot rename function return object", Nam);
887 -- In Ada 95, warn for odd case of renaming parameterless function
888 -- call if this is not a limited type (where this is useful).
891 if Warn_On_Object_Renames_Function
892 and then No (Parameter_Associations (Nam))
893 and then not Is_Limited_Type (Etype (Nam))
894 and then Comes_From_Source (Nam)
897 ("?renaming function result object is suspicious", Nam);
899 ("\?function & will be called only once", Nam,
900 Entity (Name (Nam)));
901 Error_Msg_N -- CODEFIX
902 ("\?suggest using an initialized constant object instead",
906 -- If the function call returns an unconstrained type, we must
907 -- build a constrained subtype for the new entity, in a way
908 -- similar to what is done for an object declaration with an
909 -- unconstrained nominal type.
911 if Is_Composite_Type (Etype (Nam))
912 and then not Is_Constrained (Etype (Nam))
913 and then not Has_Unknown_Discriminants (Etype (Nam))
914 and then Expander_Active
917 Loc : constant Source_Ptr := Sloc (N);
918 Subt : constant Entity_Id := Make_Temporary (Loc, 'T');
920 Remove_Side_Effects (Nam);
922 Make_Subtype_Declaration (Loc,
923 Defining_Identifier => Subt,
924 Subtype_Indication =>
925 Make_Subtype_From_Expr (Nam, Etype (Nam))));
926 Rewrite (Subtype_Mark (N), New_Occurrence_Of (Subt, Loc));
927 Set_Etype (Nam, Subt);
933 -- An object renaming requires an exact match of the type. Class-wide
934 -- matching is not allowed.
936 if Is_Class_Wide_Type (T)
937 and then Base_Type (Etype (Nam)) /= Base_Type (T)
944 -- (Ada 2005: AI-326): Handle wrong use of incomplete type
946 if Nkind (Nam) = N_Explicit_Dereference
947 and then Ekind (Etype (T2)) = E_Incomplete_Type
949 Error_Msg_NE ("invalid use of incomplete type&", Id, T2);
952 elsif Ekind (Etype (T)) = E_Incomplete_Type then
953 Error_Msg_NE ("invalid use of incomplete type&", Id, T);
959 if Ada_Version >= Ada_05
960 and then Nkind (Nam) = N_Attribute_Reference
961 and then Attribute_Name (Nam) = Name_Priority
965 elsif Ada_Version >= Ada_05
966 and then Nkind (Nam) in N_Has_Entity
973 if Nkind (Nam) = N_Attribute_Reference then
974 Nam_Ent := Entity (Prefix (Nam));
976 Nam_Ent := Entity (Nam);
979 Nam_Decl := Parent (Nam_Ent);
981 if Has_Null_Exclusion (N)
982 and then not Has_Null_Exclusion (Nam_Decl)
984 -- Ada 2005 (AI-423): If the object name denotes a generic
985 -- formal object of a generic unit G, and the object renaming
986 -- declaration occurs within the body of G or within the body
987 -- of a generic unit declared within the declarative region
988 -- of G, then the declaration of the formal object of G must
989 -- have a null exclusion or a null-excluding subtype.
991 if Is_Formal_Object (Nam_Ent)
992 and then In_Generic_Scope (Id)
994 if not Can_Never_Be_Null (Etype (Nam_Ent)) then
996 ("renamed formal does not exclude `NULL` "
997 & "(RM 8.5.1(4.6/2))", N);
999 elsif In_Package_Body (Scope (Id)) then
1001 ("formal object does not have a null exclusion"
1002 & "(RM 8.5.1(4.6/2))", N);
1005 -- Ada 2005 (AI-423): Otherwise, the subtype of the object name
1006 -- shall exclude null.
1008 elsif not Can_Never_Be_Null (Etype (Nam_Ent)) then
1010 ("renamed object does not exclude `NULL` "
1011 & "(RM 8.5.1(4.6/2))", N);
1013 -- An instance is illegal if it contains a renaming that
1014 -- excludes null, and the actual does not. The renaming
1015 -- declaration has already indicated that the declaration
1016 -- of the renamed actual in the instance will raise
1017 -- constraint_error.
1019 elsif Nkind (Nam_Decl) = N_Object_Declaration
1020 and then In_Instance
1022 (Corresponding_Generic_Association (Nam_Decl))
1023 and then Nkind (Expression (Nam_Decl))
1024 = N_Raise_Constraint_Error
1027 ("renamed actual does not exclude `NULL` "
1028 & "(RM 8.5.1(4.6/2))", N);
1030 -- Finally, if there is a null exclusion, the subtype mark
1031 -- must not be null-excluding.
1033 elsif No (Access_Definition (N))
1034 and then Can_Never_Be_Null (T)
1037 ("`NOT NULL` not allowed (& already excludes null)",
1042 elsif Can_Never_Be_Null (T)
1043 and then not Can_Never_Be_Null (Etype (Nam_Ent))
1046 ("renamed object does not exclude `NULL` "
1047 & "(RM 8.5.1(4.6/2))", N);
1049 elsif Has_Null_Exclusion (N)
1050 and then No (Access_Definition (N))
1051 and then Can_Never_Be_Null (T)
1054 ("`NOT NULL` not allowed (& already excludes null)", N, T);
1059 Set_Ekind (Id, E_Variable);
1060 Init_Size_Align (Id);
1062 if T = Any_Type or else Etype (Nam) = Any_Type then
1065 -- Verify that the renamed entity is an object or a function call. It
1066 -- may have been rewritten in several ways.
1068 elsif Is_Object_Reference (Nam) then
1069 if Comes_From_Source (N)
1070 and then Is_Dependent_Component_Of_Mutable_Object (Nam)
1073 ("illegal renaming of discriminant-dependent component", Nam);
1076 -- A static function call may have been folded into a literal
1078 elsif Nkind (Original_Node (Nam)) = N_Function_Call
1080 -- When expansion is disabled, attribute reference is not
1081 -- rewritten as function call. Otherwise it may be rewritten
1082 -- as a conversion, so check original node.
1084 or else (Nkind (Original_Node (Nam)) = N_Attribute_Reference
1085 and then Is_Function_Attribute_Name
1086 (Attribute_Name (Original_Node (Nam))))
1088 -- Weird but legal, equivalent to renaming a function call.
1089 -- Illegal if the literal is the result of constant-folding an
1090 -- attribute reference that is not a function.
1092 or else (Is_Entity_Name (Nam)
1093 and then Ekind (Entity (Nam)) = E_Enumeration_Literal
1095 Nkind (Original_Node (Nam)) /= N_Attribute_Reference)
1097 or else (Nkind (Nam) = N_Type_Conversion
1098 and then Is_Tagged_Type (Entity (Subtype_Mark (Nam))))
1102 elsif Nkind (Nam) = N_Type_Conversion then
1104 ("renaming of conversion only allowed for tagged types", Nam);
1106 -- Ada 2005 (AI-327)
1108 elsif Ada_Version >= Ada_05
1109 and then Nkind (Nam) = N_Attribute_Reference
1110 and then Attribute_Name (Nam) = Name_Priority
1114 -- Allow internally generated x'Reference expression
1116 elsif Nkind (Nam) = N_Reference then
1120 Error_Msg_N ("expect object name in renaming", Nam);
1125 if not Is_Variable (Nam) then
1126 Set_Ekind (Id, E_Constant);
1127 Set_Never_Set_In_Source (Id, True);
1128 Set_Is_True_Constant (Id, True);
1131 Set_Renamed_Object (Id, Nam);
1132 end Analyze_Object_Renaming;
1134 ------------------------------
1135 -- Analyze_Package_Renaming --
1136 ------------------------------
1138 procedure Analyze_Package_Renaming (N : Node_Id) is
1139 New_P : constant Entity_Id := Defining_Entity (N);
1144 if Name (N) = Error then
1148 -- Apply Text_IO kludge here since we may be renaming a child of Text_IO
1150 Text_IO_Kludge (Name (N));
1152 if Current_Scope /= Standard_Standard then
1153 Set_Is_Pure (New_P, Is_Pure (Current_Scope));
1159 if Is_Entity_Name (Name (N)) then
1160 Old_P := Entity (Name (N));
1165 if Etype (Old_P) = Any_Type then
1166 Error_Msg_N ("expect package name in renaming", Name (N));
1168 elsif Ekind (Old_P) /= E_Package
1169 and then not (Ekind (Old_P) = E_Generic_Package
1170 and then In_Open_Scopes (Old_P))
1172 if Ekind (Old_P) = E_Generic_Package then
1174 ("generic package cannot be renamed as a package", Name (N));
1176 Error_Msg_Sloc := Sloc (Old_P);
1178 ("expect package name in renaming, found& declared#",
1182 -- Set basic attributes to minimize cascaded errors
1184 Set_Ekind (New_P, E_Package);
1185 Set_Etype (New_P, Standard_Void_Type);
1187 -- Here for OK package renaming
1190 -- Entities in the old package are accessible through the renaming
1191 -- entity. The simplest implementation is to have both packages share
1194 Set_Ekind (New_P, E_Package);
1195 Set_Etype (New_P, Standard_Void_Type);
1197 if Present (Renamed_Object (Old_P)) then
1198 Set_Renamed_Object (New_P, Renamed_Object (Old_P));
1200 Set_Renamed_Object (New_P, Old_P);
1203 Set_Has_Completion (New_P);
1205 Set_First_Entity (New_P, First_Entity (Old_P));
1206 Set_Last_Entity (New_P, Last_Entity (Old_P));
1207 Set_First_Private_Entity (New_P, First_Private_Entity (Old_P));
1208 Check_Library_Unit_Renaming (N, Old_P);
1209 Generate_Reference (Old_P, Name (N));
1211 -- If the renaming is in the visible part of a package, then we set
1212 -- Renamed_In_Spec for the renamed package, to prevent giving
1213 -- warnings about no entities referenced. Such a warning would be
1214 -- overenthusiastic, since clients can see entities in the renamed
1215 -- package via the visible package renaming.
1218 Ent : constant Entity_Id := Cunit_Entity (Current_Sem_Unit);
1220 if Ekind (Ent) = E_Package
1221 and then not In_Private_Part (Ent)
1222 and then In_Extended_Main_Source_Unit (N)
1223 and then Ekind (Old_P) = E_Package
1225 Set_Renamed_In_Spec (Old_P);
1229 -- If this is the renaming declaration of a package instantiation
1230 -- within itself, it is the declaration that ends the list of actuals
1231 -- for the instantiation. At this point, the subtypes that rename
1232 -- the actuals are flagged as generic, to avoid spurious ambiguities
1233 -- if the actuals for two distinct formals happen to coincide. If
1234 -- the actual is a private type, the subtype has a private completion
1235 -- that is flagged in the same fashion.
1237 -- Resolution is identical to what is was in the original generic.
1238 -- On exit from the generic instance, these are turned into regular
1239 -- subtypes again, so they are compatible with types in their class.
1241 if not Is_Generic_Instance (Old_P) then
1244 Spec := Specification (Unit_Declaration_Node (Old_P));
1247 if Nkind (Spec) = N_Package_Specification
1248 and then Present (Generic_Parent (Spec))
1249 and then Old_P = Current_Scope
1250 and then Chars (New_P) = Chars (Generic_Parent (Spec))
1256 E := First_Entity (Old_P);
1261 and then Nkind (Parent (E)) = N_Subtype_Declaration
1263 Set_Is_Generic_Actual_Type (E);
1265 if Is_Private_Type (E)
1266 and then Present (Full_View (E))
1268 Set_Is_Generic_Actual_Type (Full_View (E));
1277 end Analyze_Package_Renaming;
1279 -------------------------------
1280 -- Analyze_Renamed_Character --
1281 -------------------------------
1283 procedure Analyze_Renamed_Character
1288 C : constant Node_Id := Name (N);
1291 if Ekind (New_S) = E_Function then
1292 Resolve (C, Etype (New_S));
1295 Check_Frozen_Renaming (N, New_S);
1299 Error_Msg_N ("character literal can only be renamed as function", N);
1301 end Analyze_Renamed_Character;
1303 ---------------------------------
1304 -- Analyze_Renamed_Dereference --
1305 ---------------------------------
1307 procedure Analyze_Renamed_Dereference
1312 Nam : constant Node_Id := Name (N);
1313 P : constant Node_Id := Prefix (Nam);
1319 if not Is_Overloaded (P) then
1320 if Ekind (Etype (Nam)) /= E_Subprogram_Type
1321 or else not Type_Conformant (Etype (Nam), New_S)
1323 Error_Msg_N ("designated type does not match specification", P);
1332 Get_First_Interp (Nam, Ind, It);
1334 while Present (It.Nam) loop
1336 if Ekind (It.Nam) = E_Subprogram_Type
1337 and then Type_Conformant (It.Nam, New_S)
1339 if Typ /= Any_Id then
1340 Error_Msg_N ("ambiguous renaming", P);
1347 Get_Next_Interp (Ind, It);
1350 if Typ = Any_Type then
1351 Error_Msg_N ("designated type does not match specification", P);
1356 Check_Frozen_Renaming (N, New_S);
1360 end Analyze_Renamed_Dereference;
1362 ---------------------------
1363 -- Analyze_Renamed_Entry --
1364 ---------------------------
1366 procedure Analyze_Renamed_Entry
1371 Nam : constant Node_Id := Name (N);
1372 Sel : constant Node_Id := Selector_Name (Nam);
1376 if Entity (Sel) = Any_Id then
1378 -- Selector is undefined on prefix. Error emitted already
1380 Set_Has_Completion (New_S);
1384 -- Otherwise find renamed entity and build body of New_S as a call to it
1386 Old_S := Find_Renamed_Entity (N, Selector_Name (Nam), New_S);
1388 if Old_S = Any_Id then
1389 Error_Msg_N (" no subprogram or entry matches specification", N);
1392 Check_Subtype_Conformant (New_S, Old_S, N);
1393 Generate_Reference (New_S, Defining_Entity (N), 'b');
1394 Style.Check_Identifier (Defining_Entity (N), New_S);
1397 -- Only mode conformance required for a renaming_as_declaration
1399 Check_Mode_Conformant (New_S, Old_S, N);
1402 Inherit_Renamed_Profile (New_S, Old_S);
1404 -- The prefix can be an arbitrary expression that yields a task type,
1405 -- so it must be resolved.
1407 Resolve (Prefix (Nam), Scope (Old_S));
1410 Set_Convention (New_S, Convention (Old_S));
1411 Set_Has_Completion (New_S, Inside_A_Generic);
1414 Check_Frozen_Renaming (N, New_S);
1416 end Analyze_Renamed_Entry;
1418 -----------------------------------
1419 -- Analyze_Renamed_Family_Member --
1420 -----------------------------------
1422 procedure Analyze_Renamed_Family_Member
1427 Nam : constant Node_Id := Name (N);
1428 P : constant Node_Id := Prefix (Nam);
1432 if (Is_Entity_Name (P) and then Ekind (Entity (P)) = E_Entry_Family)
1433 or else (Nkind (P) = N_Selected_Component
1435 Ekind (Entity (Selector_Name (P))) = E_Entry_Family)
1437 if Is_Entity_Name (P) then
1438 Old_S := Entity (P);
1440 Old_S := Entity (Selector_Name (P));
1443 if not Entity_Matches_Spec (Old_S, New_S) then
1444 Error_Msg_N ("entry family does not match specification", N);
1447 Check_Subtype_Conformant (New_S, Old_S, N);
1448 Generate_Reference (New_S, Defining_Entity (N), 'b');
1449 Style.Check_Identifier (Defining_Entity (N), New_S);
1453 Error_Msg_N ("no entry family matches specification", N);
1456 Set_Has_Completion (New_S, Inside_A_Generic);
1459 Check_Frozen_Renaming (N, New_S);
1461 end Analyze_Renamed_Family_Member;
1463 -----------------------------------------
1464 -- Analyze_Renamed_Primitive_Operation --
1465 -----------------------------------------
1467 procedure Analyze_Renamed_Primitive_Operation
1476 Ctyp : Conformance_Type) return Boolean;
1477 -- Verify that the signatures of the renamed entity and the new entity
1478 -- match. The first formal of the renamed entity is skipped because it
1479 -- is the target object in any subsequent call.
1483 Ctyp : Conformance_Type) return Boolean
1489 if Ekind (Subp) /= Ekind (New_S) then
1493 Old_F := Next_Formal (First_Formal (Subp));
1494 New_F := First_Formal (New_S);
1495 while Present (Old_F) and then Present (New_F) loop
1496 if not Conforming_Types (Etype (Old_F), Etype (New_F), Ctyp) then
1500 if Ctyp >= Mode_Conformant
1501 and then Ekind (Old_F) /= Ekind (New_F)
1506 Next_Formal (New_F);
1507 Next_Formal (Old_F);
1514 if not Is_Overloaded (Selector_Name (Name (N))) then
1515 Old_S := Entity (Selector_Name (Name (N)));
1517 if not Conforms (Old_S, Type_Conformant) then
1522 -- Find the operation that matches the given signature
1530 Get_First_Interp (Selector_Name (Name (N)), Ind, It);
1532 while Present (It.Nam) loop
1533 if Conforms (It.Nam, Type_Conformant) then
1537 Get_Next_Interp (Ind, It);
1542 if Old_S = Any_Id then
1543 Error_Msg_N (" no subprogram or entry matches specification", N);
1547 if not Conforms (Old_S, Subtype_Conformant) then
1548 Error_Msg_N ("subtype conformance error in renaming", N);
1551 Generate_Reference (New_S, Defining_Entity (N), 'b');
1552 Style.Check_Identifier (Defining_Entity (N), New_S);
1555 -- Only mode conformance required for a renaming_as_declaration
1557 if not Conforms (Old_S, Mode_Conformant) then
1558 Error_Msg_N ("mode conformance error in renaming", N);
1562 -- Inherit_Renamed_Profile (New_S, Old_S);
1564 -- The prefix can be an arbitrary expression that yields an
1565 -- object, so it must be resolved.
1567 Resolve (Prefix (Name (N)));
1569 end Analyze_Renamed_Primitive_Operation;
1571 ---------------------------------
1572 -- Analyze_Subprogram_Renaming --
1573 ---------------------------------
1575 procedure Analyze_Subprogram_Renaming (N : Node_Id) is
1576 Formal_Spec : constant Node_Id := Corresponding_Formal_Spec (N);
1577 Is_Actual : constant Boolean := Present (Formal_Spec);
1578 Inst_Node : Node_Id := Empty;
1579 Nam : constant Node_Id := Name (N);
1581 Old_S : Entity_Id := Empty;
1582 Rename_Spec : Entity_Id;
1583 Save_AV : constant Ada_Version_Type := Ada_Version;
1584 Save_AV_Exp : constant Ada_Version_Type := Ada_Version_Explicit;
1585 Spec : constant Node_Id := Specification (N);
1587 procedure Check_Null_Exclusion
1590 -- Ada 2005 (AI-423): Given renaming Ren of subprogram Sub, check the
1591 -- following AI rules:
1593 -- If Ren is a renaming of a formal subprogram and one of its
1594 -- parameters has a null exclusion, then the corresponding formal
1595 -- in Sub must also have one. Otherwise the subtype of the Sub's
1596 -- formal parameter must exclude null.
1598 -- If Ren is a renaming of a formal function and its return
1599 -- profile has a null exclusion, then Sub's return profile must
1600 -- have one. Otherwise the subtype of Sub's return profile must
1603 function Original_Subprogram (Subp : Entity_Id) return Entity_Id;
1604 -- Find renamed entity when the declaration is a renaming_as_body and
1605 -- the renamed entity may itself be a renaming_as_body. Used to enforce
1606 -- rule that a renaming_as_body is illegal if the declaration occurs
1607 -- before the subprogram it completes is frozen, and renaming indirectly
1608 -- renames the subprogram itself.(Defect Report 8652/0027).
1610 --------------------------
1611 -- Check_Null_Exclusion --
1612 --------------------------
1614 procedure Check_Null_Exclusion
1618 Ren_Formal : Entity_Id;
1619 Sub_Formal : Entity_Id;
1624 Ren_Formal := First_Formal (Ren);
1625 Sub_Formal := First_Formal (Sub);
1626 while Present (Ren_Formal)
1627 and then Present (Sub_Formal)
1629 if Has_Null_Exclusion (Parent (Ren_Formal))
1631 not (Has_Null_Exclusion (Parent (Sub_Formal))
1632 or else Can_Never_Be_Null (Etype (Sub_Formal)))
1635 ("`NOT NULL` required for parameter &",
1636 Parent (Sub_Formal), Sub_Formal);
1639 Next_Formal (Ren_Formal);
1640 Next_Formal (Sub_Formal);
1643 -- Return profile check
1645 if Nkind (Parent (Ren)) = N_Function_Specification
1646 and then Nkind (Parent (Sub)) = N_Function_Specification
1647 and then Has_Null_Exclusion (Parent (Ren))
1649 not (Has_Null_Exclusion (Parent (Sub))
1650 or else Can_Never_Be_Null (Etype (Sub)))
1653 ("return must specify `NOT NULL`",
1654 Result_Definition (Parent (Sub)));
1656 end Check_Null_Exclusion;
1658 -------------------------
1659 -- Original_Subprogram --
1660 -------------------------
1662 function Original_Subprogram (Subp : Entity_Id) return Entity_Id is
1663 Orig_Decl : Node_Id;
1664 Orig_Subp : Entity_Id;
1667 -- First case: renamed entity is itself a renaming
1669 if Present (Alias (Subp)) then
1670 return Alias (Subp);
1673 Nkind (Unit_Declaration_Node (Subp)) = N_Subprogram_Declaration
1675 (Corresponding_Body (Unit_Declaration_Node (Subp)))
1677 -- Check if renamed entity is a renaming_as_body
1680 Unit_Declaration_Node
1681 (Corresponding_Body (Unit_Declaration_Node (Subp)));
1683 if Nkind (Orig_Decl) = N_Subprogram_Renaming_Declaration then
1684 Orig_Subp := Entity (Name (Orig_Decl));
1686 if Orig_Subp = Rename_Spec then
1688 -- Circularity detected
1693 return (Original_Subprogram (Orig_Subp));
1701 end Original_Subprogram;
1703 -- Start of processing for Analyze_Subprogram_Renaming
1706 -- We must test for the attribute renaming case before the Analyze
1707 -- call because otherwise Sem_Attr will complain that the attribute
1708 -- is missing an argument when it is analyzed.
1710 if Nkind (Nam) = N_Attribute_Reference then
1712 -- In the case of an abstract formal subprogram association, rewrite
1713 -- an actual given by a stream attribute as the name of the
1714 -- corresponding stream primitive of the type.
1716 -- In a generic context the stream operations are not generated, and
1717 -- this must be treated as a normal attribute reference, to be
1718 -- expanded in subsequent instantiations.
1720 if Is_Actual and then Is_Abstract_Subprogram (Formal_Spec)
1721 and then Expander_Active
1724 Stream_Prim : Entity_Id;
1725 Prefix_Type : constant Entity_Id := Entity (Prefix (Nam));
1728 -- The class-wide forms of the stream attributes are not
1729 -- primitive dispatching operations (even though they
1730 -- internally dispatch to a stream attribute).
1732 if Is_Class_Wide_Type (Prefix_Type) then
1734 ("attribute must be a primitive dispatching operation",
1739 -- Retrieve the primitive subprogram associated with the
1740 -- attribute. This can only be a stream attribute, since those
1741 -- are the only ones that are dispatching (and the actual for
1742 -- an abstract formal subprogram must be dispatching
1746 case Attribute_Name (Nam) is
1749 Find_Prim_Op (Prefix_Type, TSS_Stream_Input);
1752 Find_Prim_Op (Prefix_Type, TSS_Stream_Output);
1755 Find_Prim_Op (Prefix_Type, TSS_Stream_Read);
1758 Find_Prim_Op (Prefix_Type, TSS_Stream_Write);
1761 ("attribute must be a primitive"
1762 & " dispatching operation", Nam);
1768 -- If no operation was found, and the type is limited,
1769 -- the user should have defined one.
1771 when Program_Error =>
1772 if Is_Limited_Type (Prefix_Type) then
1774 ("stream operation not defined for type&",
1778 -- Otherwise, compiler should have generated default
1785 -- Rewrite the attribute into the name of its corresponding
1786 -- primitive dispatching subprogram. We can then proceed with
1787 -- the usual processing for subprogram renamings.
1790 Prim_Name : constant Node_Id :=
1791 Make_Identifier (Sloc (Nam),
1792 Chars => Chars (Stream_Prim));
1794 Set_Entity (Prim_Name, Stream_Prim);
1795 Rewrite (Nam, Prim_Name);
1800 -- Normal processing for a renaming of an attribute
1803 Attribute_Renaming (N);
1808 -- Check whether this declaration corresponds to the instantiation
1809 -- of a formal subprogram.
1811 -- If this is an instantiation, the corresponding actual is frozen and
1812 -- error messages can be made more precise. If this is a default
1813 -- subprogram, the entity is already established in the generic, and is
1814 -- not retrieved by visibility. If it is a default with a box, the
1815 -- candidate interpretations, if any, have been collected when building
1816 -- the renaming declaration. If overloaded, the proper interpretation is
1817 -- determined in Find_Renamed_Entity. If the entity is an operator,
1818 -- Find_Renamed_Entity applies additional visibility checks.
1821 Inst_Node := Unit_Declaration_Node (Formal_Spec);
1823 if Is_Entity_Name (Nam)
1824 and then Present (Entity (Nam))
1825 and then not Comes_From_Source (Nam)
1826 and then not Is_Overloaded (Nam)
1828 Old_S := Entity (Nam);
1829 New_S := Analyze_Subprogram_Specification (Spec);
1833 if Ekind (Entity (Nam)) = E_Operator then
1837 if Box_Present (Inst_Node) then
1838 Old_S := Find_Renamed_Entity (N, Name (N), New_S, Is_Actual);
1840 -- If there is an immediately visible homonym of the operator
1841 -- and the declaration has a default, this is worth a warning
1842 -- because the user probably did not intend to get the pre-
1843 -- defined operator, visible in the generic declaration. To
1844 -- find if there is an intended candidate, analyze the renaming
1845 -- again in the current context.
1847 elsif Scope (Old_S) = Standard_Standard
1848 and then Present (Default_Name (Inst_Node))
1851 Decl : constant Node_Id := New_Copy_Tree (N);
1855 Set_Entity (Name (Decl), Empty);
1856 Analyze (Name (Decl));
1858 Find_Renamed_Entity (Decl, Name (Decl), New_S, True);
1861 and then In_Open_Scopes (Scope (Hidden))
1862 and then Is_Immediately_Visible (Hidden)
1863 and then Comes_From_Source (Hidden)
1864 and then Hidden /= Old_S
1866 Error_Msg_Sloc := Sloc (Hidden);
1867 Error_Msg_N ("?default subprogram is resolved " &
1868 "in the generic declaration " &
1869 "(RM 12.6(17))", N);
1870 Error_Msg_NE ("\?and will not use & #", N, Hidden);
1878 New_S := Analyze_Subprogram_Specification (Spec);
1882 -- Renamed entity must be analyzed first, to avoid being hidden by
1883 -- new name (which might be the same in a generic instance).
1887 -- The renaming defines a new overloaded entity, which is analyzed
1888 -- like a subprogram declaration.
1890 New_S := Analyze_Subprogram_Specification (Spec);
1893 if Current_Scope /= Standard_Standard then
1894 Set_Is_Pure (New_S, Is_Pure (Current_Scope));
1897 Rename_Spec := Find_Corresponding_Spec (N);
1899 -- Case of Renaming_As_Body
1901 if Present (Rename_Spec) then
1903 -- Renaming declaration is the completion of the declaration of
1904 -- Rename_Spec. We build an actual body for it at the freezing point.
1906 Set_Corresponding_Spec (N, Rename_Spec);
1908 -- Deal with special case of stream functions of abstract types
1911 if Nkind (Unit_Declaration_Node (Rename_Spec)) =
1912 N_Abstract_Subprogram_Declaration
1914 -- Input stream functions are abstract if the object type is
1915 -- abstract. Similarly, all default stream functions for an
1916 -- interface type are abstract. However, these subprograms may
1917 -- receive explicit declarations in representation clauses, making
1918 -- the attribute subprograms usable as defaults in subsequent
1920 -- In this case we rewrite the declaration to make the subprogram
1921 -- non-abstract. We remove the previous declaration, and insert
1922 -- the new one at the point of the renaming, to prevent premature
1923 -- access to unfrozen types. The new declaration reuses the
1924 -- specification of the previous one, and must not be analyzed.
1927 (Is_Primitive (Entity (Nam))
1929 Is_Abstract_Type (Find_Dispatching_Type (Entity (Nam))));
1931 Old_Decl : constant Node_Id :=
1932 Unit_Declaration_Node (Rename_Spec);
1933 New_Decl : constant Node_Id :=
1934 Make_Subprogram_Declaration (Sloc (N),
1936 Relocate_Node (Specification (Old_Decl)));
1939 Insert_After (N, New_Decl);
1940 Set_Is_Abstract_Subprogram (Rename_Spec, False);
1941 Set_Analyzed (New_Decl);
1945 Set_Corresponding_Body (Unit_Declaration_Node (Rename_Spec), New_S);
1947 if Ada_Version = Ada_83 and then Comes_From_Source (N) then
1948 Error_Msg_N ("(Ada 83) renaming cannot serve as a body", N);
1951 Set_Convention (New_S, Convention (Rename_Spec));
1952 Check_Fully_Conformant (New_S, Rename_Spec);
1953 Set_Public_Status (New_S);
1955 -- The specification does not introduce new formals, but only
1956 -- repeats the formals of the original subprogram declaration.
1957 -- For cross-reference purposes, and for refactoring tools, we
1958 -- treat the formals of the renaming declaration as body formals.
1960 Reference_Body_Formals (Rename_Spec, New_S);
1962 -- Indicate that the entity in the declaration functions like the
1963 -- corresponding body, and is not a new entity. The body will be
1964 -- constructed later at the freeze point, so indicate that the
1965 -- completion has not been seen yet.
1967 Set_Ekind (New_S, E_Subprogram_Body);
1968 New_S := Rename_Spec;
1969 Set_Has_Completion (Rename_Spec, False);
1971 -- Ada 2005: check overriding indicator
1973 if Is_Overriding_Operation (Rename_Spec) then
1974 if Must_Not_Override (Specification (N)) then
1976 ("subprogram& overrides inherited operation",
1979 Style_Check and then not Must_Override (Specification (N))
1981 Style.Missing_Overriding (N, Rename_Spec);
1984 elsif Must_Override (Specification (N)) then
1985 Error_Msg_NE ("subprogram& is not overriding", N, Rename_Spec);
1988 -- Normal subprogram renaming (not renaming as body)
1991 Generate_Definition (New_S);
1992 New_Overloaded_Entity (New_S);
1994 if Is_Entity_Name (Nam)
1995 and then Is_Intrinsic_Subprogram (Entity (Nam))
1999 Check_Delayed_Subprogram (New_S);
2003 -- There is no need for elaboration checks on the new entity, which may
2004 -- be called before the next freezing point where the body will appear.
2005 -- Elaboration checks refer to the real entity, not the one created by
2006 -- the renaming declaration.
2008 Set_Kill_Elaboration_Checks (New_S, True);
2010 if Etype (Nam) = Any_Type then
2011 Set_Has_Completion (New_S);
2014 elsif Nkind (Nam) = N_Selected_Component then
2016 -- A prefix of the form A.B can designate an entry of task A, a
2017 -- protected operation of protected object A, or finally a primitive
2018 -- operation of object A. In the later case, A is an object of some
2019 -- tagged type, or an access type that denotes one such. To further
2020 -- distinguish these cases, note that the scope of a task entry or
2021 -- protected operation is type of the prefix.
2023 -- The prefix could be an overloaded function call that returns both
2024 -- kinds of operations. This overloading pathology is left to the
2025 -- dedicated reader ???
2028 T : constant Entity_Id := Etype (Prefix (Nam));
2037 Is_Tagged_Type (Designated_Type (T))))
2038 and then Scope (Entity (Selector_Name (Nam))) /= T
2040 Analyze_Renamed_Primitive_Operation
2041 (N, New_S, Present (Rename_Spec));
2045 -- Renamed entity is an entry or protected operation. For those
2046 -- cases an explicit body is built (at the point of freezing of
2047 -- this entity) that contains a call to the renamed entity.
2049 -- This is not allowed for renaming as body if the renamed
2050 -- spec is already frozen (see RM 8.5.4(5) for details).
2052 if Present (Rename_Spec)
2053 and then Is_Frozen (Rename_Spec)
2056 ("renaming-as-body cannot rename entry as subprogram", N);
2058 ("\since & is already frozen (RM 8.5.4(5))",
2061 Analyze_Renamed_Entry (N, New_S, Present (Rename_Spec));
2068 elsif Nkind (Nam) = N_Explicit_Dereference then
2070 -- Renamed entity is designated by access_to_subprogram expression.
2071 -- Must build body to encapsulate call, as in the entry case.
2073 Analyze_Renamed_Dereference (N, New_S, Present (Rename_Spec));
2076 elsif Nkind (Nam) = N_Indexed_Component then
2077 Analyze_Renamed_Family_Member (N, New_S, Present (Rename_Spec));
2080 elsif Nkind (Nam) = N_Character_Literal then
2081 Analyze_Renamed_Character (N, New_S, Present (Rename_Spec));
2084 elsif (not Is_Entity_Name (Nam)
2085 and then Nkind (Nam) /= N_Operator_Symbol)
2086 or else not Is_Overloadable (Entity (Nam))
2088 Error_Msg_N ("expect valid subprogram name in renaming", N);
2092 -- Find the renamed entity that matches the given specification. Disable
2093 -- Ada_83 because there is no requirement of full conformance between
2094 -- renamed entity and new entity, even though the same circuit is used.
2096 -- This is a bit of a kludge, which introduces a really irregular use of
2097 -- Ada_Version[_Explicit]. Would be nice to find cleaner way to do this
2100 Ada_Version := Ada_Version_Type'Max (Ada_Version, Ada_95);
2101 Ada_Version_Explicit := Ada_Version;
2104 Old_S := Find_Renamed_Entity (N, Name (N), New_S, Is_Actual);
2106 -- When the renamed subprogram is overloaded and used as an actual
2107 -- of a generic, its entity is set to the first available homonym.
2108 -- We must first disambiguate the name, then set the proper entity.
2111 and then Is_Overloaded (Nam)
2113 Set_Entity (Nam, Old_S);
2117 -- Most common case: subprogram renames subprogram. No body is generated
2118 -- in this case, so we must indicate the declaration is complete as is.
2119 -- and inherit various attributes of the renamed subprogram.
2121 if No (Rename_Spec) then
2122 Set_Has_Completion (New_S);
2123 Set_Is_Imported (New_S, Is_Imported (Entity (Nam)));
2124 Set_Is_Pure (New_S, Is_Pure (Entity (Nam)));
2125 Set_Is_Preelaborated (New_S, Is_Preelaborated (Entity (Nam)));
2127 -- Ada 2005 (AI-423): Check the consistency of null exclusions
2128 -- between a subprogram and its correct renaming.
2130 -- Note: the Any_Id check is a guard that prevents compiler crashes
2131 -- when performing a null exclusion check between a renaming and a
2132 -- renamed subprogram that has been found to be illegal.
2134 if Ada_Version >= Ada_05
2135 and then Entity (Nam) /= Any_Id
2137 Check_Null_Exclusion
2139 Sub => Entity (Nam));
2142 -- Enforce the Ada 2005 rule that the renamed entity cannot require
2143 -- overriding. The flag Requires_Overriding is set very selectively
2144 -- and misses some other illegal cases. The additional conditions
2145 -- checked below are sufficient but not necessary ???
2147 -- The rule does not apply to the renaming generated for an actual
2148 -- subprogram in an instance.
2153 -- Guard against previous errors, and omit renamings of predefined
2156 elsif not Ekind_In (Old_S, E_Function, E_Procedure) then
2159 elsif Requires_Overriding (Old_S)
2161 (Is_Abstract_Subprogram (Old_S)
2162 and then Present (Find_Dispatching_Type (Old_S))
2164 not Is_Abstract_Type (Find_Dispatching_Type (Old_S)))
2167 ("renamed entity cannot be "
2168 & "subprogram that requires overriding (RM 8.5.4 (5.1))", N);
2172 if Old_S /= Any_Id then
2174 and then From_Default (N)
2176 -- This is an implicit reference to the default actual
2178 Generate_Reference (Old_S, Nam, Typ => 'i', Force => True);
2180 Generate_Reference (Old_S, Nam);
2183 -- For a renaming-as-body, require subtype conformance, but if the
2184 -- declaration being completed has not been frozen, then inherit the
2185 -- convention of the renamed subprogram prior to checking conformance
2186 -- (unless the renaming has an explicit convention established; the
2187 -- rule stated in the RM doesn't seem to address this ???).
2189 if Present (Rename_Spec) then
2190 Generate_Reference (Rename_Spec, Defining_Entity (Spec), 'b');
2191 Style.Check_Identifier (Defining_Entity (Spec), Rename_Spec);
2193 if not Is_Frozen (Rename_Spec) then
2194 if not Has_Convention_Pragma (Rename_Spec) then
2195 Set_Convention (New_S, Convention (Old_S));
2198 if Ekind (Old_S) /= E_Operator then
2199 Check_Mode_Conformant (New_S, Old_S, Spec);
2202 if Original_Subprogram (Old_S) = Rename_Spec then
2203 Error_Msg_N ("unfrozen subprogram cannot rename itself ", N);
2206 Check_Subtype_Conformant (New_S, Old_S, Spec);
2209 Check_Frozen_Renaming (N, Rename_Spec);
2211 -- Check explicitly that renamed entity is not intrinsic, because
2212 -- in a generic the renamed body is not built. In this case,
2213 -- the renaming_as_body is a completion.
2215 if Inside_A_Generic then
2216 if Is_Frozen (Rename_Spec)
2217 and then Is_Intrinsic_Subprogram (Old_S)
2220 ("subprogram in renaming_as_body cannot be intrinsic",
2224 Set_Has_Completion (Rename_Spec);
2227 elsif Ekind (Old_S) /= E_Operator then
2228 Check_Mode_Conformant (New_S, Old_S);
2231 and then Error_Posted (New_S)
2233 Error_Msg_NE ("invalid actual subprogram: & #!", N, Old_S);
2237 if No (Rename_Spec) then
2239 -- The parameter profile of the new entity is that of the renamed
2240 -- entity: the subtypes given in the specification are irrelevant.
2242 Inherit_Renamed_Profile (New_S, Old_S);
2244 -- A call to the subprogram is transformed into a call to the
2245 -- renamed entity. This is transitive if the renamed entity is
2246 -- itself a renaming.
2248 if Present (Alias (Old_S)) then
2249 Set_Alias (New_S, Alias (Old_S));
2251 Set_Alias (New_S, Old_S);
2254 -- Note that we do not set Is_Intrinsic_Subprogram if we have a
2255 -- renaming as body, since the entity in this case is not an
2256 -- intrinsic (it calls an intrinsic, but we have a real body for
2257 -- this call, and it is in this body that the required intrinsic
2258 -- processing will take place).
2260 -- Also, if this is a renaming of inequality, the renamed operator
2261 -- is intrinsic, but what matters is the corresponding equality
2262 -- operator, which may be user-defined.
2264 Set_Is_Intrinsic_Subprogram
2266 Is_Intrinsic_Subprogram (Old_S)
2268 (Chars (Old_S) /= Name_Op_Ne
2269 or else Ekind (Old_S) = E_Operator
2271 Is_Intrinsic_Subprogram
2272 (Corresponding_Equality (Old_S))));
2274 if Ekind (Alias (New_S)) = E_Operator then
2275 Set_Has_Delayed_Freeze (New_S, False);
2278 -- If the renaming corresponds to an association for an abstract
2279 -- formal subprogram, then various attributes must be set to
2280 -- indicate that the renaming is an abstract dispatching operation
2281 -- with a controlling type.
2283 if Is_Actual and then Is_Abstract_Subprogram (Formal_Spec) then
2285 -- Mark the renaming as abstract here, so Find_Dispatching_Type
2286 -- see it as corresponding to a generic association for a
2287 -- formal abstract subprogram
2289 Set_Is_Abstract_Subprogram (New_S);
2292 New_S_Ctrl_Type : constant Entity_Id :=
2293 Find_Dispatching_Type (New_S);
2294 Old_S_Ctrl_Type : constant Entity_Id :=
2295 Find_Dispatching_Type (Old_S);
2298 if Old_S_Ctrl_Type /= New_S_Ctrl_Type then
2300 ("actual must be dispatching subprogram for type&",
2301 Nam, New_S_Ctrl_Type);
2304 Set_Is_Dispatching_Operation (New_S);
2305 Check_Controlling_Formals (New_S_Ctrl_Type, New_S);
2307 -- If the actual in the formal subprogram is itself a
2308 -- formal abstract subprogram association, there's no
2309 -- dispatch table component or position to inherit.
2311 if Present (DTC_Entity (Old_S)) then
2312 Set_DTC_Entity (New_S, DTC_Entity (Old_S));
2313 Set_DT_Position (New_S, DT_Position (Old_S));
2321 and then (Old_S = New_S
2322 or else (Nkind (Nam) /= N_Expanded_Name
2323 and then Chars (Old_S) = Chars (New_S)))
2325 Error_Msg_N ("subprogram cannot rename itself", N);
2328 Set_Convention (New_S, Convention (Old_S));
2330 if Is_Abstract_Subprogram (Old_S) then
2331 if Present (Rename_Spec) then
2333 ("a renaming-as-body cannot rename an abstract subprogram",
2335 Set_Has_Completion (Rename_Spec);
2337 Set_Is_Abstract_Subprogram (New_S);
2341 Check_Library_Unit_Renaming (N, Old_S);
2343 -- Pathological case: procedure renames entry in the scope of its
2344 -- task. Entry is given by simple name, but body must be built for
2345 -- procedure. Of course if called it will deadlock.
2347 if Ekind (Old_S) = E_Entry then
2348 Set_Has_Completion (New_S, False);
2349 Set_Alias (New_S, Empty);
2353 Freeze_Before (N, Old_S);
2354 Set_Has_Delayed_Freeze (New_S, False);
2355 Freeze_Before (N, New_S);
2357 -- An abstract subprogram is only allowed as an actual in the case
2358 -- where the formal subprogram is also abstract.
2360 if (Ekind (Old_S) = E_Procedure or else Ekind (Old_S) = E_Function)
2361 and then Is_Abstract_Subprogram (Old_S)
2362 and then not Is_Abstract_Subprogram (Formal_Spec)
2365 ("abstract subprogram not allowed as generic actual", Nam);
2370 -- A common error is to assume that implicit operators for types are
2371 -- defined in Standard, or in the scope of a subtype. In those cases
2372 -- where the renamed entity is given with an expanded name, it is
2373 -- worth mentioning that operators for the type are not declared in
2374 -- the scope given by the prefix.
2376 if Nkind (Nam) = N_Expanded_Name
2377 and then Nkind (Selector_Name (Nam)) = N_Operator_Symbol
2378 and then Scope (Entity (Nam)) = Standard_Standard
2381 T : constant Entity_Id :=
2382 Base_Type (Etype (First_Formal (New_S)));
2384 Error_Msg_Node_2 := Prefix (Nam);
2386 ("operator for type& is not declared in&", Prefix (Nam), T);
2391 ("no visible subprogram matches the specification for&",
2395 if Present (Candidate_Renaming) then
2402 F1 := First_Formal (Candidate_Renaming);
2403 F2 := First_Formal (New_S);
2404 T1 := First_Subtype (Etype (F1));
2406 while Present (F1) and then Present (F2) loop
2411 if Present (F1) and then Present (Default_Value (F1)) then
2412 if Present (Next_Formal (F1)) then
2414 ("\missing specification for &" &
2415 " and other formals with defaults", Spec, F1);
2418 ("\missing specification for &", Spec, F1);
2422 if Nkind (Nam) = N_Operator_Symbol
2423 and then From_Default (N)
2425 Error_Msg_Node_2 := T1;
2427 ("default & on & is not directly visible",
2434 -- Ada 2005 AI 404: if the new subprogram is dispatching, verify that
2435 -- controlling access parameters are known non-null for the renamed
2436 -- subprogram. Test also applies to a subprogram instantiation that
2437 -- is dispatching. Test is skipped if some previous error was detected
2438 -- that set Old_S to Any_Id.
2440 if Ada_Version >= Ada_05
2441 and then Old_S /= Any_Id
2442 and then not Is_Dispatching_Operation (Old_S)
2443 and then Is_Dispatching_Operation (New_S)
2450 Old_F := First_Formal (Old_S);
2451 New_F := First_Formal (New_S);
2452 while Present (Old_F) loop
2453 if Ekind (Etype (Old_F)) = E_Anonymous_Access_Type
2454 and then Is_Controlling_Formal (New_F)
2455 and then not Can_Never_Be_Null (Old_F)
2457 Error_Msg_N ("access parameter is controlling,", New_F);
2459 ("\corresponding parameter of& "
2460 & "must be explicitly null excluding", New_F, Old_S);
2463 Next_Formal (Old_F);
2464 Next_Formal (New_F);
2469 -- A useful warning, suggested by Ada Bug Finder (Ada-Europe 2005)
2471 if Comes_From_Source (N)
2472 and then Present (Old_S)
2473 and then Nkind (Old_S) = N_Defining_Operator_Symbol
2474 and then Nkind (New_S) = N_Defining_Operator_Symbol
2475 and then Chars (Old_S) /= Chars (New_S)
2478 ("?& is being renamed as a different operator",
2482 -- Another warning or some utility: if the new subprogram as the same
2483 -- name as the old one, the old one is not hidden by an outer homograph,
2484 -- the new one is not a public symbol, and the old one is otherwise
2485 -- directly visible, the renaming is superfluous.
2487 if Chars (Old_S) = Chars (New_S)
2488 and then Comes_From_Source (N)
2489 and then Scope (Old_S) /= Standard_Standard
2490 and then Warn_On_Redundant_Constructs
2492 (Is_Immediately_Visible (Old_S)
2493 or else Is_Potentially_Use_Visible (Old_S))
2494 and then Is_Overloadable (Current_Scope)
2495 and then Chars (Current_Scope) /= Chars (Old_S)
2498 ("?redundant renaming, entity is directly visible", Name (N));
2501 Ada_Version := Save_AV;
2502 Ada_Version_Explicit := Save_AV_Exp;
2503 end Analyze_Subprogram_Renaming;
2505 -------------------------
2506 -- Analyze_Use_Package --
2507 -------------------------
2509 -- Resolve the package names in the use clause, and make all the visible
2510 -- entities defined in the package potentially use-visible. If the package
2511 -- is already in use from a previous use clause, its visible entities are
2512 -- already use-visible. In that case, mark the occurrence as a redundant
2513 -- use. If the package is an open scope, i.e. if the use clause occurs
2514 -- within the package itself, ignore it.
2516 procedure Analyze_Use_Package (N : Node_Id) is
2517 Pack_Name : Node_Id;
2520 -- Start of processing for Analyze_Use_Package
2523 Set_Hidden_By_Use_Clause (N, No_Elist);
2525 -- Use clause is not allowed in a spec of a predefined package
2526 -- declaration except that packages whose file name starts a-n are OK
2527 -- (these are children of Ada.Numerics, and such packages are never
2528 -- loaded by Rtsfind).
2530 if Is_Predefined_File_Name (Unit_File_Name (Current_Sem_Unit))
2531 and then Name_Buffer (1 .. 3) /= "a-n"
2533 Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Declaration
2535 Error_Msg_N ("use clause not allowed in predefined spec", N);
2538 -- Chain clause to list of use clauses in current scope
2540 if Nkind (Parent (N)) /= N_Compilation_Unit then
2541 Chain_Use_Clause (N);
2544 -- Loop through package names to identify referenced packages
2546 Pack_Name := First (Names (N));
2547 while Present (Pack_Name) loop
2548 Analyze (Pack_Name);
2550 if Nkind (Parent (N)) = N_Compilation_Unit
2551 and then Nkind (Pack_Name) = N_Expanded_Name
2557 Pref := Prefix (Pack_Name);
2558 while Nkind (Pref) = N_Expanded_Name loop
2559 Pref := Prefix (Pref);
2562 if Entity (Pref) = Standard_Standard then
2564 ("predefined package Standard cannot appear"
2565 & " in a context clause", Pref);
2573 -- Loop through package names to mark all entities as potentially
2576 Pack_Name := First (Names (N));
2577 while Present (Pack_Name) loop
2578 if Is_Entity_Name (Pack_Name) then
2579 Pack := Entity (Pack_Name);
2581 if Ekind (Pack) /= E_Package
2582 and then Etype (Pack) /= Any_Type
2584 if Ekind (Pack) = E_Generic_Package then
2585 Error_Msg_N -- CODEFIX
2586 ("a generic package is not allowed in a use clause",
2589 Error_Msg_N ("& is not a usable package", Pack_Name);
2593 if Nkind (Parent (N)) = N_Compilation_Unit then
2594 Check_In_Previous_With_Clause (N, Pack_Name);
2597 if Applicable_Use (Pack_Name) then
2598 Use_One_Package (Pack, N);
2602 -- Report error because name denotes something other than a package
2605 Error_Msg_N ("& is not a package", Pack_Name);
2610 end Analyze_Use_Package;
2612 ----------------------
2613 -- Analyze_Use_Type --
2614 ----------------------
2616 procedure Analyze_Use_Type (N : Node_Id) is
2621 Set_Hidden_By_Use_Clause (N, No_Elist);
2623 -- Chain clause to list of use clauses in current scope
2625 if Nkind (Parent (N)) /= N_Compilation_Unit then
2626 Chain_Use_Clause (N);
2629 Id := First (Subtype_Marks (N));
2630 while Present (Id) loop
2634 if E /= Any_Type then
2637 if Nkind (Parent (N)) = N_Compilation_Unit then
2638 if Nkind (Id) = N_Identifier then
2639 Error_Msg_N ("type is not directly visible", Id);
2641 elsif Is_Child_Unit (Scope (E))
2642 and then Scope (E) /= System_Aux_Id
2644 Check_In_Previous_With_Clause (N, Prefix (Id));
2649 -- If the use_type_clause appears in a compilation unit context,
2650 -- check whether it comes from a unit that may appear in a
2651 -- limited_with_clause, for a better error message.
2653 if Nkind (Parent (N)) = N_Compilation_Unit
2654 and then Nkind (Id) /= N_Identifier
2660 function Mentioned (Nam : Node_Id) return Boolean;
2661 -- Check whether the prefix of expanded name for the type
2662 -- appears in the prefix of some limited_with_clause.
2668 function Mentioned (Nam : Node_Id) return Boolean is
2670 return Nkind (Name (Item)) = N_Selected_Component
2672 Chars (Prefix (Name (Item))) = Chars (Nam);
2676 Pref := Prefix (Id);
2677 Item := First (Context_Items (Parent (N)));
2679 while Present (Item) and then Item /= N loop
2680 if Nkind (Item) = N_With_Clause
2681 and then Limited_Present (Item)
2682 and then Mentioned (Pref)
2685 (Get_Msg_Id, "premature usage of incomplete type");
2696 end Analyze_Use_Type;
2698 --------------------
2699 -- Applicable_Use --
2700 --------------------
2702 function Applicable_Use (Pack_Name : Node_Id) return Boolean is
2703 Pack : constant Entity_Id := Entity (Pack_Name);
2706 if In_Open_Scopes (Pack) then
2707 if Warn_On_Redundant_Constructs
2708 and then Pack = Current_Scope
2710 Error_Msg_NE -- CODEFIX
2711 ("& is already use-visible within itself?", Pack_Name, Pack);
2716 elsif In_Use (Pack) then
2717 Note_Redundant_Use (Pack_Name);
2720 elsif Present (Renamed_Object (Pack))
2721 and then In_Use (Renamed_Object (Pack))
2723 Note_Redundant_Use (Pack_Name);
2731 ------------------------
2732 -- Attribute_Renaming --
2733 ------------------------
2735 procedure Attribute_Renaming (N : Node_Id) is
2736 Loc : constant Source_Ptr := Sloc (N);
2737 Nam : constant Node_Id := Name (N);
2738 Spec : constant Node_Id := Specification (N);
2739 New_S : constant Entity_Id := Defining_Unit_Name (Spec);
2740 Aname : constant Name_Id := Attribute_Name (Nam);
2742 Form_Num : Nat := 0;
2743 Expr_List : List_Id := No_List;
2745 Attr_Node : Node_Id;
2746 Body_Node : Node_Id;
2747 Param_Spec : Node_Id;
2750 Generate_Definition (New_S);
2752 -- This procedure is called in the context of subprogram renaming, and
2753 -- thus the attribute must be one that is a subprogram. All of those
2754 -- have at least one formal parameter, with the singular exception of
2755 -- AST_Entry (which is a real oddity, it is odd that this can be renamed
2758 if not Is_Non_Empty_List (Parameter_Specifications (Spec)) then
2759 if Aname /= Name_AST_Entry then
2761 ("subprogram renaming an attribute must have formals", N);
2766 Param_Spec := First (Parameter_Specifications (Spec));
2767 while Present (Param_Spec) loop
2768 Form_Num := Form_Num + 1;
2770 if Nkind (Parameter_Type (Param_Spec)) /= N_Access_Definition then
2771 Find_Type (Parameter_Type (Param_Spec));
2773 -- The profile of the new entity denotes the base type (s) of
2774 -- the types given in the specification. For access parameters
2775 -- there are no subtypes involved.
2777 Rewrite (Parameter_Type (Param_Spec),
2779 (Base_Type (Entity (Parameter_Type (Param_Spec))), Loc));
2782 if No (Expr_List) then
2783 Expr_List := New_List;
2786 Append_To (Expr_List,
2787 Make_Identifier (Loc,
2788 Chars => Chars (Defining_Identifier (Param_Spec))));
2790 -- The expressions in the attribute reference are not freeze
2791 -- points. Neither is the attribute as a whole, see below.
2793 Set_Must_Not_Freeze (Last (Expr_List));
2798 -- Immediate error if too many formals. Other mismatches in number or
2799 -- types of parameters are detected when we analyze the body of the
2800 -- subprogram that we construct.
2802 if Form_Num > 2 then
2803 Error_Msg_N ("too many formals for attribute", N);
2805 -- Error if the attribute reference has expressions that look like
2806 -- formal parameters.
2808 elsif Present (Expressions (Nam)) then
2809 Error_Msg_N ("illegal expressions in attribute reference", Nam);
2812 Aname = Name_Compose or else
2813 Aname = Name_Exponent or else
2814 Aname = Name_Leading_Part or else
2815 Aname = Name_Pos or else
2816 Aname = Name_Round or else
2817 Aname = Name_Scaling or else
2820 if Nkind (N) = N_Subprogram_Renaming_Declaration
2821 and then Present (Corresponding_Formal_Spec (N))
2824 ("generic actual cannot be attribute involving universal type",
2828 ("attribute involving a universal type cannot be renamed",
2833 -- AST_Entry is an odd case. It doesn't really make much sense to allow
2834 -- it to be renamed, but that's the DEC rule, so we have to do it right.
2835 -- The point is that the AST_Entry call should be made now, and what the
2836 -- function will return is the returned value.
2838 -- Note that there is no Expr_List in this case anyway
2840 if Aname = Name_AST_Entry then
2842 Ent : constant Entity_Id := Make_Temporary (Loc, 'R', Nam);
2847 Make_Object_Declaration (Loc,
2848 Defining_Identifier => Ent,
2849 Object_Definition =>
2850 New_Occurrence_Of (RTE (RE_AST_Handler), Loc),
2852 Constant_Present => True);
2854 Set_Assignment_OK (Decl, True);
2855 Insert_Action (N, Decl);
2856 Attr_Node := Make_Identifier (Loc, Chars (Ent));
2859 -- For all other attributes, we rewrite the attribute node to have
2860 -- a list of expressions corresponding to the subprogram formals.
2861 -- A renaming declaration is not a freeze point, and the analysis of
2862 -- the attribute reference should not freeze the type of the prefix.
2866 Make_Attribute_Reference (Loc,
2867 Prefix => Prefix (Nam),
2868 Attribute_Name => Aname,
2869 Expressions => Expr_List);
2871 Set_Must_Not_Freeze (Attr_Node);
2872 Set_Must_Not_Freeze (Prefix (Nam));
2875 -- Case of renaming a function
2877 if Nkind (Spec) = N_Function_Specification then
2878 if Is_Procedure_Attribute_Name (Aname) then
2879 Error_Msg_N ("attribute can only be renamed as procedure", Nam);
2883 Find_Type (Result_Definition (Spec));
2884 Rewrite (Result_Definition (Spec),
2886 Base_Type (Entity (Result_Definition (Spec))), Loc));
2889 Make_Subprogram_Body (Loc,
2890 Specification => Spec,
2891 Declarations => New_List,
2892 Handled_Statement_Sequence =>
2893 Make_Handled_Sequence_Of_Statements (Loc,
2894 Statements => New_List (
2895 Make_Simple_Return_Statement (Loc,
2896 Expression => Attr_Node))));
2898 -- Case of renaming a procedure
2901 if not Is_Procedure_Attribute_Name (Aname) then
2902 Error_Msg_N ("attribute can only be renamed as function", Nam);
2907 Make_Subprogram_Body (Loc,
2908 Specification => Spec,
2909 Declarations => New_List,
2910 Handled_Statement_Sequence =>
2911 Make_Handled_Sequence_Of_Statements (Loc,
2912 Statements => New_List (Attr_Node)));
2915 -- In case of tagged types we add the body of the generated function to
2916 -- the freezing actions of the type (because in the general case such
2917 -- type is still not frozen). We exclude from this processing generic
2918 -- formal subprograms found in instantiations and AST_Entry renamings.
2920 if not Present (Corresponding_Formal_Spec (N))
2921 and then Etype (Nam) /= RTE (RE_AST_Handler)
2924 P : constant Entity_Id := Prefix (Nam);
2929 if Is_Tagged_Type (Etype (P)) then
2930 Ensure_Freeze_Node (Etype (P));
2931 Append_Freeze_Action (Etype (P), Body_Node);
2933 Rewrite (N, Body_Node);
2935 Set_Etype (New_S, Base_Type (Etype (New_S)));
2939 -- Generic formal subprograms or AST_Handler renaming
2942 Rewrite (N, Body_Node);
2944 Set_Etype (New_S, Base_Type (Etype (New_S)));
2947 if Is_Compilation_Unit (New_S) then
2949 ("a library unit can only rename another library unit", N);
2952 -- We suppress elaboration warnings for the resulting entity, since
2953 -- clearly they are not needed, and more particularly, in the case
2954 -- of a generic formal subprogram, the resulting entity can appear
2955 -- after the instantiation itself, and thus look like a bogus case
2956 -- of access before elaboration.
2958 Set_Suppress_Elaboration_Warnings (New_S);
2960 end Attribute_Renaming;
2962 ----------------------
2963 -- Chain_Use_Clause --
2964 ----------------------
2966 procedure Chain_Use_Clause (N : Node_Id) is
2968 Level : Int := Scope_Stack.Last;
2971 if not Is_Compilation_Unit (Current_Scope)
2972 or else not Is_Child_Unit (Current_Scope)
2974 null; -- Common case
2976 elsif Defining_Entity (Parent (N)) = Current_Scope then
2977 null; -- Common case for compilation unit
2980 -- If declaration appears in some other scope, it must be in some
2981 -- parent unit when compiling a child.
2983 Pack := Defining_Entity (Parent (N));
2984 if not In_Open_Scopes (Pack) then
2985 null; -- default as well
2988 -- Find entry for parent unit in scope stack
2990 while Scope_Stack.Table (Level).Entity /= Pack loop
2996 Set_Next_Use_Clause (N,
2997 Scope_Stack.Table (Level).First_Use_Clause);
2998 Scope_Stack.Table (Level).First_Use_Clause := N;
2999 end Chain_Use_Clause;
3001 ---------------------------
3002 -- Check_Frozen_Renaming --
3003 ---------------------------
3005 procedure Check_Frozen_Renaming (N : Node_Id; Subp : Entity_Id) is
3011 and then not Has_Completion (Subp)
3015 (Parent (Declaration_Node (Subp)), Defining_Entity (N));
3017 if Is_Entity_Name (Name (N)) then
3018 Old_S := Entity (Name (N));
3020 if not Is_Frozen (Old_S)
3021 and then Operating_Mode /= Check_Semantics
3023 Append_Freeze_Action (Old_S, B_Node);
3025 Insert_After (N, B_Node);
3029 if Is_Intrinsic_Subprogram (Old_S)
3030 and then not In_Instance
3033 ("subprogram used in renaming_as_body cannot be intrinsic",
3038 Insert_After (N, B_Node);
3042 end Check_Frozen_Renaming;
3044 -------------------------------
3045 -- Set_Entity_Or_Discriminal --
3046 -------------------------------
3048 procedure Set_Entity_Or_Discriminal (N : Node_Id; E : Entity_Id) is
3052 -- If the entity is not a discriminant, or else expansion is disabled,
3053 -- simply set the entity.
3055 if not In_Spec_Expression
3056 or else Ekind (E) /= E_Discriminant
3057 or else Inside_A_Generic
3059 Set_Entity_With_Style_Check (N, E);
3061 -- The replacement of a discriminant by the corresponding discriminal
3062 -- is not done for a task discriminant that appears in a default
3063 -- expression of an entry parameter. See Expand_Discriminant in exp_ch2
3064 -- for details on their handling.
3066 elsif Is_Concurrent_Type (Scope (E)) then
3070 and then not Nkind_In (P, N_Parameter_Specification,
3071 N_Component_Declaration)
3077 and then Nkind (P) = N_Parameter_Specification
3082 Set_Entity (N, Discriminal (E));
3085 -- Otherwise, this is a discriminant in a context in which
3086 -- it is a reference to the corresponding parameter of the
3087 -- init proc for the enclosing type.
3090 Set_Entity (N, Discriminal (E));
3092 end Set_Entity_Or_Discriminal;
3094 -----------------------------------
3095 -- Check_In_Previous_With_Clause --
3096 -----------------------------------
3098 procedure Check_In_Previous_With_Clause
3102 Pack : constant Entity_Id := Entity (Original_Node (Nam));
3107 Item := First (Context_Items (Parent (N)));
3109 while Present (Item)
3112 if Nkind (Item) = N_With_Clause
3114 -- Protect the frontend against previous critical errors
3116 and then Nkind (Name (Item)) /= N_Selected_Component
3117 and then Entity (Name (Item)) = Pack
3121 -- Find root library unit in with_clause
3123 while Nkind (Par) = N_Expanded_Name loop
3124 Par := Prefix (Par);
3127 if Is_Child_Unit (Entity (Original_Node (Par))) then
3128 Error_Msg_NE ("& is not directly visible", Par, Entity (Par));
3137 -- On exit, package is not mentioned in a previous with_clause.
3138 -- Check if its prefix is.
3140 if Nkind (Nam) = N_Expanded_Name then
3141 Check_In_Previous_With_Clause (N, Prefix (Nam));
3143 elsif Pack /= Any_Id then
3144 Error_Msg_NE ("& is not visible", Nam, Pack);
3146 end Check_In_Previous_With_Clause;
3148 ---------------------------------
3149 -- Check_Library_Unit_Renaming --
3150 ---------------------------------
3152 procedure Check_Library_Unit_Renaming (N : Node_Id; Old_E : Entity_Id) is
3156 if Nkind (Parent (N)) /= N_Compilation_Unit then
3159 -- Check for library unit. Note that we used to check for the scope
3160 -- being Standard here, but that was wrong for Standard itself.
3162 elsif not Is_Compilation_Unit (Old_E)
3163 and then not Is_Child_Unit (Old_E)
3165 Error_Msg_N ("renamed unit must be a library unit", Name (N));
3167 -- Entities defined in Standard (operators and boolean literals) cannot
3168 -- be renamed as library units.
3170 elsif Scope (Old_E) = Standard_Standard
3171 and then Sloc (Old_E) = Standard_Location
3173 Error_Msg_N ("renamed unit must be a library unit", Name (N));
3175 elsif Present (Parent_Spec (N))
3176 and then Nkind (Unit (Parent_Spec (N))) = N_Generic_Package_Declaration
3177 and then not Is_Child_Unit (Old_E)
3180 ("renamed unit must be a child unit of generic parent", Name (N));
3182 elsif Nkind (N) in N_Generic_Renaming_Declaration
3183 and then Nkind (Name (N)) = N_Expanded_Name
3184 and then Is_Generic_Instance (Entity (Prefix (Name (N))))
3185 and then Is_Generic_Unit (Old_E)
3188 ("renamed generic unit must be a library unit", Name (N));
3190 elsif Is_Package_Or_Generic_Package (Old_E) then
3192 -- Inherit categorization flags
3194 New_E := Defining_Entity (N);
3195 Set_Is_Pure (New_E, Is_Pure (Old_E));
3196 Set_Is_Preelaborated (New_E, Is_Preelaborated (Old_E));
3197 Set_Is_Remote_Call_Interface (New_E,
3198 Is_Remote_Call_Interface (Old_E));
3199 Set_Is_Remote_Types (New_E, Is_Remote_Types (Old_E));
3200 Set_Is_Shared_Passive (New_E, Is_Shared_Passive (Old_E));
3202 end Check_Library_Unit_Renaming;
3208 procedure End_Scope is
3214 Id := First_Entity (Current_Scope);
3215 while Present (Id) loop
3216 -- An entity in the current scope is not necessarily the first one
3217 -- on its homonym chain. Find its predecessor if any,
3218 -- If it is an internal entity, it will not be in the visibility
3219 -- chain altogether, and there is nothing to unchain.
3221 if Id /= Current_Entity (Id) then
3222 Prev := Current_Entity (Id);
3223 while Present (Prev)
3224 and then Present (Homonym (Prev))
3225 and then Homonym (Prev) /= Id
3227 Prev := Homonym (Prev);
3230 -- Skip to end of loop if Id is not in the visibility chain
3232 if No (Prev) or else Homonym (Prev) /= Id then
3240 Set_Is_Immediately_Visible (Id, False);
3242 Outer := Homonym (Id);
3243 while Present (Outer) and then Scope (Outer) = Current_Scope loop
3244 Outer := Homonym (Outer);
3247 -- Reset homonym link of other entities, but do not modify link
3248 -- between entities in current scope, so that the back-end can have
3249 -- a proper count of local overloadings.
3252 Set_Name_Entity_Id (Chars (Id), Outer);
3254 elsif Scope (Prev) /= Scope (Id) then
3255 Set_Homonym (Prev, Outer);
3262 -- If the scope generated freeze actions, place them before the
3263 -- current declaration and analyze them. Type declarations and
3264 -- the bodies of initialization procedures can generate such nodes.
3265 -- We follow the parent chain until we reach a list node, which is
3266 -- the enclosing list of declarations. If the list appears within
3267 -- a protected definition, move freeze nodes outside the protected
3271 (Scope_Stack.Table (Scope_Stack.Last).Pending_Freeze_Actions)
3275 L : constant List_Id := Scope_Stack.Table
3276 (Scope_Stack.Last).Pending_Freeze_Actions;
3279 if Is_Itype (Current_Scope) then
3280 Decl := Associated_Node_For_Itype (Current_Scope);
3282 Decl := Parent (Current_Scope);
3287 while not (Is_List_Member (Decl))
3288 or else Nkind_In (Parent (Decl), N_Protected_Definition,
3291 Decl := Parent (Decl);
3294 Insert_List_Before_And_Analyze (Decl, L);
3303 ---------------------
3304 -- End_Use_Clauses --
3305 ---------------------
3307 procedure End_Use_Clauses (Clause : Node_Id) is
3311 -- Remove Use_Type clauses first, because they affect the
3312 -- visibility of operators in subsequent used packages.
3315 while Present (U) loop
3316 if Nkind (U) = N_Use_Type_Clause then
3320 Next_Use_Clause (U);
3324 while Present (U) loop
3325 if Nkind (U) = N_Use_Package_Clause then
3326 End_Use_Package (U);
3329 Next_Use_Clause (U);
3331 end End_Use_Clauses;
3333 ---------------------
3334 -- End_Use_Package --
3335 ---------------------
3337 procedure End_Use_Package (N : Node_Id) is
3338 Pack_Name : Node_Id;
3343 function Is_Primitive_Operator
3345 F : Entity_Id) return Boolean;
3346 -- Check whether Op is a primitive operator of a use-visible type
3348 ---------------------------
3349 -- Is_Primitive_Operator --
3350 ---------------------------
3352 function Is_Primitive_Operator
3354 F : Entity_Id) return Boolean
3356 T : constant Entity_Id := Etype (F);
3359 and then Scope (T) = Scope (Op);
3360 end Is_Primitive_Operator;
3362 -- Start of processing for End_Use_Package
3365 Pack_Name := First (Names (N));
3366 while Present (Pack_Name) loop
3368 -- Test that Pack_Name actually denotes a package before processing
3370 if Is_Entity_Name (Pack_Name)
3371 and then Ekind (Entity (Pack_Name)) = E_Package
3373 Pack := Entity (Pack_Name);
3375 if In_Open_Scopes (Pack) then
3378 elsif not Redundant_Use (Pack_Name) then
3379 Set_In_Use (Pack, False);
3380 Set_Current_Use_Clause (Pack, Empty);
3382 Id := First_Entity (Pack);
3383 while Present (Id) loop
3385 -- Preserve use-visibility of operators that are primitive
3386 -- operators of a type that is use-visible through an active
3389 if Nkind (Id) = N_Defining_Operator_Symbol
3391 (Is_Primitive_Operator (Id, First_Formal (Id))
3393 (Present (Next_Formal (First_Formal (Id)))
3395 Is_Primitive_Operator
3396 (Id, Next_Formal (First_Formal (Id)))))
3401 Set_Is_Potentially_Use_Visible (Id, False);
3404 if Is_Private_Type (Id)
3405 and then Present (Full_View (Id))
3407 Set_Is_Potentially_Use_Visible (Full_View (Id), False);
3413 if Present (Renamed_Object (Pack)) then
3414 Set_In_Use (Renamed_Object (Pack), False);
3415 Set_Current_Use_Clause (Renamed_Object (Pack), Empty);
3418 if Chars (Pack) = Name_System
3419 and then Scope (Pack) = Standard_Standard
3420 and then Present_System_Aux
3422 Id := First_Entity (System_Aux_Id);
3423 while Present (Id) loop
3424 Set_Is_Potentially_Use_Visible (Id, False);
3426 if Is_Private_Type (Id)
3427 and then Present (Full_View (Id))
3429 Set_Is_Potentially_Use_Visible (Full_View (Id), False);
3435 Set_In_Use (System_Aux_Id, False);
3439 Set_Redundant_Use (Pack_Name, False);
3446 if Present (Hidden_By_Use_Clause (N)) then
3447 Elmt := First_Elmt (Hidden_By_Use_Clause (N));
3448 while Present (Elmt) loop
3450 E : constant Entity_Id := Node (Elmt);
3453 -- Reset either Use_Visibility or Direct_Visibility, depending
3454 -- on how the entity was hidden by the use clause.
3456 if In_Use (Scope (E))
3457 and then Used_As_Generic_Actual (Scope (E))
3459 Set_Is_Potentially_Use_Visible (Node (Elmt));
3461 Set_Is_Immediately_Visible (Node (Elmt));
3468 Set_Hidden_By_Use_Clause (N, No_Elist);
3470 end End_Use_Package;
3476 procedure End_Use_Type (N : Node_Id) is
3483 function May_Be_Used_Primitive_Of (T : Entity_Id) return Boolean;
3484 -- An operator may be primitive in several types, if they are declared
3485 -- in the same scope as the operator. To determine the use-visiblity of
3486 -- the operator in such cases we must examine all types in the profile.
3488 ------------------------------
3489 -- May_Be_Used_Primitive_Of --
3490 ------------------------------
3492 function May_Be_Used_Primitive_Of (T : Entity_Id) return Boolean is
3494 return Scope (Op) = Scope (T)
3495 and then (In_Use (T) or else Is_Potentially_Use_Visible (T));
3496 end May_Be_Used_Primitive_Of;
3498 -- Start of processing for End_Use_Type
3501 Id := First (Subtype_Marks (N));
3502 while Present (Id) loop
3504 -- A call to Rtsfind may occur while analyzing a use_type clause,
3505 -- in which case the type marks are not resolved yet, and there is
3506 -- nothing to remove.
3508 if not Is_Entity_Name (Id) or else No (Entity (Id)) then
3514 if T = Any_Type or else From_With_Type (T) then
3517 -- Note that the use_type clause may mention a subtype of the type
3518 -- whose primitive operations have been made visible. Here as
3519 -- elsewhere, it is the base type that matters for visibility.
3521 elsif In_Open_Scopes (Scope (Base_Type (T))) then
3524 elsif not Redundant_Use (Id) then
3525 Set_In_Use (T, False);
3526 Set_In_Use (Base_Type (T), False);
3527 Set_Current_Use_Clause (T, Empty);
3528 Set_Current_Use_Clause (Base_Type (T), Empty);
3529 Op_List := Collect_Primitive_Operations (T);
3531 Elmt := First_Elmt (Op_List);
3532 while Present (Elmt) loop
3535 if Nkind (Op) = N_Defining_Operator_Symbol then
3537 T_First : constant Entity_Id :=
3538 Base_Type (Etype (First_Formal (Op)));
3539 T_Res : constant Entity_Id := Base_Type (Etype (Op));
3543 if Present (Next_Formal (First_Formal (Op))) then
3545 Base_Type (Etype (Next_Formal (First_Formal (Op))));
3550 if not May_Be_Used_Primitive_Of (T_First)
3551 and then not May_Be_Used_Primitive_Of (T_Next)
3552 and then not May_Be_Used_Primitive_Of (T_Res)
3554 Set_Is_Potentially_Use_Visible (Op, False);
3568 ----------------------
3569 -- Find_Direct_Name --
3570 ----------------------
3572 procedure Find_Direct_Name (N : Node_Id) is
3577 Inst : Entity_Id := Empty;
3578 -- Enclosing instance, if any
3580 Homonyms : Entity_Id;
3581 -- Saves start of homonym chain
3583 Nvis_Entity : Boolean;
3584 -- Set True to indicate that there is at least one entity on the homonym
3585 -- chain which, while not visible, is visible enough from the user point
3586 -- of view to warrant an error message of "not visible" rather than
3589 Nvis_Is_Private_Subprg : Boolean := False;
3590 -- Ada 2005 (AI-262): Set True to indicate that a form of Beaujolais
3591 -- effect concerning library subprograms has been detected. Used to
3592 -- generate the precise error message.
3594 function From_Actual_Package (E : Entity_Id) return Boolean;
3595 -- Returns true if the entity is declared in a package that is
3596 -- an actual for a formal package of the current instance. Such an
3597 -- entity requires special handling because it may be use-visible
3598 -- but hides directly visible entities defined outside the instance.
3600 function Is_Actual_Parameter return Boolean;
3601 -- This function checks if the node N is an identifier that is an actual
3602 -- parameter of a procedure call. If so it returns True, otherwise it
3603 -- return False. The reason for this check is that at this stage we do
3604 -- not know what procedure is being called if the procedure might be
3605 -- overloaded, so it is premature to go setting referenced flags or
3606 -- making calls to Generate_Reference. We will wait till Resolve_Actuals
3607 -- for that processing
3609 function Known_But_Invisible (E : Entity_Id) return Boolean;
3610 -- This function determines whether the entity E (which is not
3611 -- visible) can reasonably be considered to be known to the writer
3612 -- of the reference. This is a heuristic test, used only for the
3613 -- purposes of figuring out whether we prefer to complain that an
3614 -- entity is undefined or invisible (and identify the declaration
3615 -- of the invisible entity in the latter case). The point here is
3616 -- that we don't want to complain that something is invisible and
3617 -- then point to something entirely mysterious to the writer.
3619 procedure Nvis_Messages;
3620 -- Called if there are no visible entries for N, but there is at least
3621 -- one non-directly visible, or hidden declaration. This procedure
3622 -- outputs an appropriate set of error messages.
3624 procedure Undefined (Nvis : Boolean);
3625 -- This function is called if the current node has no corresponding
3626 -- visible entity or entities. The value set in Msg indicates whether
3627 -- an error message was generated (multiple error messages for the
3628 -- same variable are generally suppressed, see body for details).
3629 -- Msg is True if an error message was generated, False if not. This
3630 -- value is used by the caller to determine whether or not to output
3631 -- additional messages where appropriate. The parameter is set False
3632 -- to get the message "X is undefined", and True to get the message
3633 -- "X is not visible".
3635 -------------------------
3636 -- From_Actual_Package --
3637 -------------------------
3639 function From_Actual_Package (E : Entity_Id) return Boolean is
3640 Scop : constant Entity_Id := Scope (E);
3644 if not In_Instance then
3647 Inst := Current_Scope;
3648 while Present (Inst)
3649 and then Ekind (Inst) /= E_Package
3650 and then not Is_Generic_Instance (Inst)
3652 Inst := Scope (Inst);
3659 Act := First_Entity (Inst);
3660 while Present (Act) loop
3661 if Ekind (Act) = E_Package then
3663 -- Check for end of actuals list
3665 if Renamed_Object (Act) = Inst then
3668 elsif Present (Associated_Formal_Package (Act))
3669 and then Renamed_Object (Act) = Scop
3671 -- Entity comes from (instance of) formal package
3686 end From_Actual_Package;
3688 -------------------------
3689 -- Is_Actual_Parameter --
3690 -------------------------
3692 function Is_Actual_Parameter return Boolean is
3695 Nkind (N) = N_Identifier
3697 (Nkind (Parent (N)) = N_Procedure_Call_Statement
3699 (Nkind (Parent (N)) = N_Parameter_Association
3700 and then N = Explicit_Actual_Parameter (Parent (N))
3701 and then Nkind (Parent (Parent (N))) =
3702 N_Procedure_Call_Statement));
3703 end Is_Actual_Parameter;
3705 -------------------------
3706 -- Known_But_Invisible --
3707 -------------------------
3709 function Known_But_Invisible (E : Entity_Id) return Boolean is
3710 Fname : File_Name_Type;
3713 -- Entities in Standard are always considered to be known
3715 if Sloc (E) <= Standard_Location then
3718 -- An entity that does not come from source is always considered
3719 -- to be unknown, since it is an artifact of code expansion.
3721 elsif not Comes_From_Source (E) then
3724 -- In gnat internal mode, we consider all entities known
3726 elsif GNAT_Mode then
3730 -- Here we have an entity that is not from package Standard, and
3731 -- which comes from Source. See if it comes from an internal file.
3733 Fname := Unit_File_Name (Get_Source_Unit (E));
3735 -- Case of from internal file
3737 if Is_Internal_File_Name (Fname) then
3739 -- Private part entities in internal files are never considered
3740 -- to be known to the writer of normal application code.
3742 if Is_Hidden (E) then
3746 -- Entities from System packages other than System and
3747 -- System.Storage_Elements are not considered to be known.
3748 -- System.Auxxxx files are also considered known to the user.
3750 -- Should refine this at some point to generally distinguish
3751 -- between known and unknown internal files ???
3753 Get_Name_String (Fname);
3758 Name_Buffer (1 .. 2) /= "s-"
3760 Name_Buffer (3 .. 8) = "stoele"
3762 Name_Buffer (3 .. 5) = "aux";
3764 -- If not an internal file, then entity is definitely known,
3765 -- even if it is in a private part (the message generated will
3766 -- note that it is in a private part)
3771 end Known_But_Invisible;
3777 procedure Nvis_Messages is
3778 Comp_Unit : Node_Id;
3780 Found : Boolean := False;
3781 Hidden : Boolean := False;
3785 -- Ada 2005 (AI-262): Generate a precise error concerning the
3786 -- Beaujolais effect that was previously detected
3788 if Nvis_Is_Private_Subprg then
3790 pragma Assert (Nkind (E2) = N_Defining_Identifier
3791 and then Ekind (E2) = E_Function
3792 and then Scope (E2) = Standard_Standard
3793 and then Has_Private_With (E2));
3795 -- Find the sloc corresponding to the private with'ed unit
3797 Comp_Unit := Cunit (Current_Sem_Unit);
3798 Error_Msg_Sloc := No_Location;
3800 Item := First (Context_Items (Comp_Unit));
3801 while Present (Item) loop
3802 if Nkind (Item) = N_With_Clause
3803 and then Private_Present (Item)
3804 and then Entity (Name (Item)) = E2
3806 Error_Msg_Sloc := Sloc (Item);
3813 pragma Assert (Error_Msg_Sloc /= No_Location);
3815 Error_Msg_N ("(Ada 2005): hidden by private with clause #", N);
3819 Undefined (Nvis => True);
3823 -- First loop does hidden declarations
3826 while Present (Ent) loop
3827 if Is_Potentially_Use_Visible (Ent) then
3829 Error_Msg_N -- CODEFIX
3830 ("multiple use clauses cause hiding!", N);
3834 Error_Msg_Sloc := Sloc (Ent);
3835 Error_Msg_N -- CODEFIX
3836 ("hidden declaration#!", N);
3839 Ent := Homonym (Ent);
3842 -- If we found hidden declarations, then that's enough, don't
3843 -- bother looking for non-visible declarations as well.
3849 -- Second loop does non-directly visible declarations
3852 while Present (Ent) loop
3853 if not Is_Potentially_Use_Visible (Ent) then
3855 -- Do not bother the user with unknown entities
3857 if not Known_But_Invisible (Ent) then
3861 Error_Msg_Sloc := Sloc (Ent);
3863 -- Output message noting that there is a non-visible
3864 -- declaration, distinguishing the private part case.
3866 if Is_Hidden (Ent) then
3867 Error_Msg_N ("non-visible (private) declaration#!", N);
3869 -- If the entity is declared in a generic package, it
3870 -- cannot be visible, so there is no point in adding it
3871 -- to the list of candidates if another homograph from a
3872 -- non-generic package has been seen.
3874 elsif Ekind (Scope (Ent)) = E_Generic_Package
3880 Error_Msg_N -- CODEFIX
3881 ("non-visible declaration#!", N);
3883 if Ekind (Scope (Ent)) /= E_Generic_Package then
3887 if Is_Compilation_Unit (Ent)
3889 Nkind (Parent (Parent (N))) = N_Use_Package_Clause
3891 Error_Msg_Qual_Level := 99;
3892 Error_Msg_NE -- CODEFIX
3893 ("\\missing `WITH &;`", N, Ent);
3894 Error_Msg_Qual_Level := 0;
3897 if Ekind (Ent) = E_Discriminant
3898 and then Present (Corresponding_Discriminant (Ent))
3899 and then Scope (Corresponding_Discriminant (Ent)) =
3903 ("inherited discriminant not allowed here" &
3904 " (RM 3.8 (12), 3.8.1 (6))!", N);
3908 -- Set entity and its containing package as referenced. We
3909 -- can't be sure of this, but this seems a better choice
3910 -- to avoid unused entity messages.
3912 if Comes_From_Source (Ent) then
3913 Set_Referenced (Ent);
3914 Set_Referenced (Cunit_Entity (Get_Source_Unit (Ent)));
3919 Ent := Homonym (Ent);
3928 procedure Undefined (Nvis : Boolean) is
3929 Emsg : Error_Msg_Id;
3932 -- We should never find an undefined internal name. If we do, then
3933 -- see if we have previous errors. If so, ignore on the grounds that
3934 -- it is probably a cascaded message (e.g. a block label from a badly
3935 -- formed block). If no previous errors, then we have a real internal
3936 -- error of some kind so raise an exception.
3938 if Is_Internal_Name (Chars (N)) then
3939 if Total_Errors_Detected /= 0 then
3942 raise Program_Error;
3946 -- A very specialized error check, if the undefined variable is
3947 -- a case tag, and the case type is an enumeration type, check
3948 -- for a possible misspelling, and if so, modify the identifier
3950 -- Named aggregate should also be handled similarly ???
3952 if Nkind (N) = N_Identifier
3953 and then Nkind (Parent (N)) = N_Case_Statement_Alternative
3956 Case_Stm : constant Node_Id := Parent (Parent (N));
3957 Case_Typ : constant Entity_Id := Etype (Expression (Case_Stm));
3962 if Is_Enumeration_Type (Case_Typ)
3963 and then not Is_Standard_Character_Type (Case_Typ)
3965 Lit := First_Literal (Case_Typ);
3966 Get_Name_String (Chars (Lit));
3968 if Chars (Lit) /= Chars (N)
3969 and then Is_Bad_Spelling_Of (Chars (N), Chars (Lit)) then
3970 Error_Msg_Node_2 := Lit;
3971 Error_Msg_N -- CODEFIX
3972 ("& is undefined, assume misspelling of &", N);
3973 Rewrite (N, New_Occurrence_Of (Lit, Sloc (N)));
3977 Lit := Next_Literal (Lit);
3982 -- Normal processing
3984 Set_Entity (N, Any_Id);
3985 Set_Etype (N, Any_Type);
3987 -- We use the table Urefs to keep track of entities for which we
3988 -- have issued errors for undefined references. Multiple errors
3989 -- for a single name are normally suppressed, however we modify
3990 -- the error message to alert the programmer to this effect.
3992 for J in Urefs.First .. Urefs.Last loop
3993 if Chars (N) = Chars (Urefs.Table (J).Node) then
3994 if Urefs.Table (J).Err /= No_Error_Msg
3995 and then Sloc (N) /= Urefs.Table (J).Loc
3997 Error_Msg_Node_1 := Urefs.Table (J).Node;
3999 if Urefs.Table (J).Nvis then
4000 Change_Error_Text (Urefs.Table (J).Err,
4001 "& is not visible (more references follow)");
4003 Change_Error_Text (Urefs.Table (J).Err,
4004 "& is undefined (more references follow)");
4007 Urefs.Table (J).Err := No_Error_Msg;
4010 -- Although we will set Msg False, and thus suppress the
4011 -- message, we also set Error_Posted True, to avoid any
4012 -- cascaded messages resulting from the undefined reference.
4015 Set_Error_Posted (N, True);
4020 -- If entry not found, this is first undefined occurrence
4023 Error_Msg_N ("& is not visible!", N);
4027 Error_Msg_N ("& is undefined!", N);
4030 -- A very bizarre special check, if the undefined identifier
4031 -- is put or put_line, then add a special error message (since
4032 -- this is a very common error for beginners to make).
4034 if Chars (N) = Name_Put or else Chars (N) = Name_Put_Line then
4035 Error_Msg_N -- CODEFIX
4036 ("\\possible missing `WITH Ada.Text_'I'O; " &
4037 "USE Ada.Text_'I'O`!", N);
4039 -- Another special check if N is the prefix of a selected
4040 -- component which is a known unit, add message complaining
4041 -- about missing with for this unit.
4043 elsif Nkind (Parent (N)) = N_Selected_Component
4044 and then N = Prefix (Parent (N))
4045 and then Is_Known_Unit (Parent (N))
4047 Error_Msg_Node_2 := Selector_Name (Parent (N));
4048 Error_Msg_N -- CODEFIX
4049 ("\\missing `WITH &.&;`", Prefix (Parent (N)));
4052 -- Now check for possible misspellings
4056 Ematch : Entity_Id := Empty;
4058 Last_Name_Id : constant Name_Id :=
4059 Name_Id (Nat (First_Name_Id) +
4060 Name_Entries_Count - 1);
4063 for Nam in First_Name_Id .. Last_Name_Id loop
4064 E := Get_Name_Entity_Id (Nam);
4067 and then (Is_Immediately_Visible (E)
4069 Is_Potentially_Use_Visible (E))
4071 if Is_Bad_Spelling_Of (Chars (N), Nam) then
4078 if Present (Ematch) then
4079 Error_Msg_NE -- CODEFIX
4080 ("\possible misspelling of&", N, Ematch);
4085 -- Make entry in undefined references table unless the full errors
4086 -- switch is set, in which case by refraining from generating the
4087 -- table entry, we guarantee that we get an error message for every
4088 -- undefined reference.
4090 if not All_Errors_Mode then
4101 -- Start of processing for Find_Direct_Name
4104 -- If the entity pointer is already set, this is an internal node, or
4105 -- a node that is analyzed more than once, after a tree modification.
4106 -- In such a case there is no resolution to perform, just set the type.
4108 if Present (Entity (N)) then
4109 if Is_Type (Entity (N)) then
4110 Set_Etype (N, Entity (N));
4114 Entyp : constant Entity_Id := Etype (Entity (N));
4117 -- One special case here. If the Etype field is already set,
4118 -- and references the packed array type corresponding to the
4119 -- etype of the referenced entity, then leave it alone. This
4120 -- happens for trees generated from Exp_Pakd, where expressions
4121 -- can be deliberately "mis-typed" to the packed array type.
4123 if Is_Array_Type (Entyp)
4124 and then Is_Packed (Entyp)
4125 and then Present (Etype (N))
4126 and then Etype (N) = Packed_Array_Type (Entyp)
4130 -- If not that special case, then just reset the Etype
4133 Set_Etype (N, Etype (Entity (N)));
4141 -- Here if Entity pointer was not set, we need full visibility analysis
4142 -- First we generate debugging output if the debug E flag is set.
4144 if Debug_Flag_E then
4145 Write_Str ("Looking for ");
4146 Write_Name (Chars (N));
4150 Homonyms := Current_Entity (N);
4151 Nvis_Entity := False;
4154 while Present (E) loop
4156 -- If entity is immediately visible or potentially use visible, then
4157 -- process the entity and we are done.
4159 if Is_Immediately_Visible (E) then
4160 goto Immediately_Visible_Entity;
4162 elsif Is_Potentially_Use_Visible (E) then
4163 goto Potentially_Use_Visible_Entity;
4165 -- Note if a known but invisible entity encountered
4167 elsif Known_But_Invisible (E) then
4168 Nvis_Entity := True;
4171 -- Move to next entity in chain and continue search
4176 -- If no entries on homonym chain that were potentially visible,
4177 -- and no entities reasonably considered as non-visible, then
4178 -- we have a plain undefined reference, with no additional
4179 -- explanation required!
4181 if not Nvis_Entity then
4182 Undefined (Nvis => False);
4184 -- Otherwise there is at least one entry on the homonym chain that
4185 -- is reasonably considered as being known and non-visible.
4193 -- Processing for a potentially use visible entry found. We must search
4194 -- the rest of the homonym chain for two reasons. First, if there is a
4195 -- directly visible entry, then none of the potentially use-visible
4196 -- entities are directly visible (RM 8.4(10)). Second, we need to check
4197 -- for the case of multiple potentially use-visible entries hiding one
4198 -- another and as a result being non-directly visible (RM 8.4(11)).
4200 <<Potentially_Use_Visible_Entity>> declare
4201 Only_One_Visible : Boolean := True;
4202 All_Overloadable : Boolean := Is_Overloadable (E);
4206 while Present (E2) loop
4207 if Is_Immediately_Visible (E2) then
4209 -- If the use-visible entity comes from the actual for a
4210 -- formal package, it hides a directly visible entity from
4211 -- outside the instance.
4213 if From_Actual_Package (E)
4214 and then Scope_Depth (E2) < Scope_Depth (Inst)
4219 goto Immediately_Visible_Entity;
4222 elsif Is_Potentially_Use_Visible (E2) then
4223 Only_One_Visible := False;
4224 All_Overloadable := All_Overloadable and Is_Overloadable (E2);
4226 -- Ada 2005 (AI-262): Protect against a form of Beaujolais effect
4227 -- that can occur in private_with clauses. Example:
4230 -- private with B; package A is
4231 -- package C is function B return Integer;
4233 -- V1 : Integer := B;
4234 -- private function B return Integer;
4235 -- V2 : Integer := B;
4238 -- V1 resolves to A.B, but V2 resolves to library unit B
4240 elsif Ekind (E2) = E_Function
4241 and then Scope (E2) = Standard_Standard
4242 and then Has_Private_With (E2)
4244 Only_One_Visible := False;
4245 All_Overloadable := False;
4246 Nvis_Is_Private_Subprg := True;
4253 -- On falling through this loop, we have checked that there are no
4254 -- immediately visible entities. Only_One_Visible is set if exactly
4255 -- one potentially use visible entity exists. All_Overloadable is
4256 -- set if all the potentially use visible entities are overloadable.
4257 -- The condition for legality is that either there is one potentially
4258 -- use visible entity, or if there is more than one, then all of them
4259 -- are overloadable.
4261 if Only_One_Visible or All_Overloadable then
4264 -- If there is more than one potentially use-visible entity and at
4265 -- least one of them non-overloadable, we have an error (RM 8.4(11).
4266 -- Note that E points to the first such entity on the homonym list.
4267 -- Special case: if one of the entities is declared in an actual
4268 -- package, it was visible in the generic, and takes precedence over
4269 -- other entities that are potentially use-visible. Same if it is
4270 -- declared in a local instantiation of the current instance.
4275 -- Find current instance
4277 Inst := Current_Scope;
4278 while Present (Inst)
4279 and then Inst /= Standard_Standard
4281 if Is_Generic_Instance (Inst) then
4285 Inst := Scope (Inst);
4289 while Present (E2) loop
4290 if From_Actual_Package (E2)
4292 (Is_Generic_Instance (Scope (E2))
4293 and then Scope_Depth (Scope (E2)) > Scope_Depth (Inst))
4306 Is_Predefined_File_Name (Unit_File_Name (Current_Sem_Unit))
4308 -- A use-clause in the body of a system file creates conflict
4309 -- with some entity in a user scope, while rtsfind is active.
4310 -- Keep only the entity coming from another predefined unit.
4313 while Present (E2) loop
4314 if Is_Predefined_File_Name
4315 (Unit_File_Name (Get_Source_Unit (Sloc (E2))))
4324 -- Entity must exist because predefined unit is correct
4326 raise Program_Error;
4335 -- Come here with E set to the first immediately visible entity on
4336 -- the homonym chain. This is the one we want unless there is another
4337 -- immediately visible entity further on in the chain for an inner
4338 -- scope (RM 8.3(8)).
4340 <<Immediately_Visible_Entity>> declare
4345 -- Find scope level of initial entity. When compiling through
4346 -- Rtsfind, the previous context is not completely invisible, and
4347 -- an outer entity may appear on the chain, whose scope is below
4348 -- the entry for Standard that delimits the current scope stack.
4349 -- Indicate that the level for this spurious entry is outside of
4350 -- the current scope stack.
4352 Level := Scope_Stack.Last;
4354 Scop := Scope_Stack.Table (Level).Entity;
4355 exit when Scop = Scope (E);
4357 exit when Scop = Standard_Standard;
4360 -- Now search remainder of homonym chain for more inner entry
4361 -- If the entity is Standard itself, it has no scope, and we
4362 -- compare it with the stack entry directly.
4365 while Present (E2) loop
4366 if Is_Immediately_Visible (E2) then
4368 -- If a generic package contains a local declaration that
4369 -- has the same name as the generic, there may be a visibility
4370 -- conflict in an instance, where the local declaration must
4371 -- also hide the name of the corresponding package renaming.
4372 -- We check explicitly for a package declared by a renaming,
4373 -- whose renamed entity is an instance that is on the scope
4374 -- stack, and that contains a homonym in the same scope. Once
4375 -- we have found it, we know that the package renaming is not
4376 -- immediately visible, and that the identifier denotes the
4377 -- other entity (and its homonyms if overloaded).
4379 if Scope (E) = Scope (E2)
4380 and then Ekind (E) = E_Package
4381 and then Present (Renamed_Object (E))
4382 and then Is_Generic_Instance (Renamed_Object (E))
4383 and then In_Open_Scopes (Renamed_Object (E))
4384 and then Comes_From_Source (N)
4386 Set_Is_Immediately_Visible (E, False);
4390 for J in Level + 1 .. Scope_Stack.Last loop
4391 if Scope_Stack.Table (J).Entity = Scope (E2)
4392 or else Scope_Stack.Table (J).Entity = E2
4405 -- At the end of that loop, E is the innermost immediately
4406 -- visible entity, so we are all set.
4409 -- Come here with entity found, and stored in E
4413 -- When distribution features are available (Get_PCS_Name /=
4414 -- Name_No_DSA), a remote access-to-subprogram type is converted
4415 -- into a record type holding whatever information is needed to
4416 -- perform a remote call on an RCI subprogram. In that case we
4417 -- rewrite any occurrence of the RAS type into the equivalent record
4418 -- type here. 'Access attribute references and RAS dereferences are
4419 -- then implemented using specific TSSs. However when distribution is
4420 -- not available (case of Get_PCS_Name = Name_No_DSA), we bypass the
4421 -- generation of these TSSs, and we must keep the RAS type in its
4422 -- original access-to-subprogram form (since all calls through a
4423 -- value of such type will be local anyway in the absence of a PCS).
4425 if Comes_From_Source (N)
4426 and then Is_Remote_Access_To_Subprogram_Type (E)
4427 and then Expander_Active
4428 and then Get_PCS_Name /= Name_No_DSA
4431 New_Occurrence_Of (Equivalent_Type (E), Sloc (N)));
4435 -- Set the entity. Note that the reason we call Set_Entity for the
4436 -- overloadable case, as opposed to Set_Entity_With_Style_Check is
4437 -- that in the overloaded case, the initial call can set the wrong
4438 -- homonym. The call that sets the right homonym is in Sem_Res and
4439 -- that call does use Set_Entity_With_Style_Check, so we don't miss
4442 if Is_Overloadable (E) then
4445 Set_Entity_With_Style_Check (N, E);
4451 Set_Etype (N, Get_Full_View (Etype (E)));
4454 if Debug_Flag_E then
4455 Write_Str (" found ");
4456 Write_Entity_Info (E, " ");
4459 -- If the Ekind of the entity is Void, it means that all homonyms
4460 -- are hidden from all visibility (RM 8.3(5,14-20)). However, this
4461 -- test is skipped if the current scope is a record and the name is
4462 -- a pragma argument expression (case of Atomic and Volatile pragmas
4463 -- and possibly other similar pragmas added later, which are allowed
4464 -- to reference components in the current record).
4466 if Ekind (E) = E_Void
4468 (not Is_Record_Type (Current_Scope)
4469 or else Nkind (Parent (N)) /= N_Pragma_Argument_Association)
4471 Premature_Usage (N);
4473 -- If the entity is overloadable, collect all interpretations of the
4474 -- name for subsequent overload resolution. We optimize a bit here to
4475 -- do this only if we have an overloadable entity that is not on its
4476 -- own on the homonym chain.
4478 elsif Is_Overloadable (E)
4479 and then (Present (Homonym (E)) or else Current_Entity (N) /= E)
4481 Collect_Interps (N);
4483 -- If no homonyms were visible, the entity is unambiguous
4485 if not Is_Overloaded (N) then
4486 if not Is_Actual_Parameter then
4487 Generate_Reference (E, N);
4491 -- Case of non-overloadable entity, set the entity providing that
4492 -- we do not have the case of a discriminant reference within a
4493 -- default expression. Such references are replaced with the
4494 -- corresponding discriminal, which is the formal corresponding to
4495 -- to the discriminant in the initialization procedure.
4498 -- Entity is unambiguous, indicate that it is referenced here
4500 -- For a renaming of an object, always generate simple reference,
4501 -- we don't try to keep track of assignments in this case.
4503 if Is_Object (E) and then Present (Renamed_Object (E)) then
4504 Generate_Reference (E, N);
4506 -- If the renamed entity is a private protected component,
4507 -- reference the original component as well. This needs to be
4508 -- done because the private renamings are installed before any
4509 -- analysis has occurred. Reference to a private component will
4510 -- resolve to the renaming and the original component will be
4511 -- left unreferenced, hence the following.
4513 if Is_Prival (E) then
4514 Generate_Reference (Prival_Link (E), N);
4517 -- One odd case is that we do not want to set the Referenced flag
4518 -- if the entity is a label, and the identifier is the label in
4519 -- the source, since this is not a reference from the point of
4520 -- view of the user.
4522 elsif Nkind (Parent (N)) = N_Label then
4524 R : constant Boolean := Referenced (E);
4527 -- Generate reference unless this is an actual parameter
4528 -- (see comment below)
4530 if Is_Actual_Parameter then
4531 Generate_Reference (E, N);
4532 Set_Referenced (E, R);
4536 -- Normal case, not a label: generate reference
4538 -- ??? It is too early to generate a reference here even if
4539 -- the entity is unambiguous, because the tree is not
4540 -- sufficiently typed at this point for Generate_Reference to
4541 -- determine whether this reference modifies the denoted object
4542 -- (because implicit dereferences cannot be identified prior to
4543 -- full type resolution).
4545 -- The Is_Actual_Parameter routine takes care of one of these
4546 -- cases but there are others probably ???
4549 if not Is_Actual_Parameter then
4550 Generate_Reference (E, N);
4553 Check_Nested_Access (E);
4556 Set_Entity_Or_Discriminal (N, E);
4559 end Find_Direct_Name;
4561 ------------------------
4562 -- Find_Expanded_Name --
4563 ------------------------
4565 -- This routine searches the homonym chain of the entity until it finds
4566 -- an entity declared in the scope denoted by the prefix. If the entity
4567 -- is private, it may nevertheless be immediately visible, if we are in
4568 -- the scope of its declaration.
4570 procedure Find_Expanded_Name (N : Node_Id) is
4571 Selector : constant Node_Id := Selector_Name (N);
4572 Candidate : Entity_Id := Empty;
4578 P_Name := Entity (Prefix (N));
4581 -- If the prefix is a renamed package, look for the entity in the
4582 -- original package.
4584 if Ekind (P_Name) = E_Package
4585 and then Present (Renamed_Object (P_Name))
4587 P_Name := Renamed_Object (P_Name);
4589 -- Rewrite node with entity field pointing to renamed object
4591 Rewrite (Prefix (N), New_Copy (Prefix (N)));
4592 Set_Entity (Prefix (N), P_Name);
4594 -- If the prefix is an object of a concurrent type, look for
4595 -- the entity in the associated task or protected type.
4597 elsif Is_Concurrent_Type (Etype (P_Name)) then
4598 P_Name := Etype (P_Name);
4601 Id := Current_Entity (Selector);
4604 Is_New_Candidate : Boolean;
4607 while Present (Id) loop
4608 if Scope (Id) = P_Name then
4610 Is_New_Candidate := True;
4612 -- Ada 2005 (AI-217): Handle shadow entities associated with types
4613 -- declared in limited-withed nested packages. We don't need to
4614 -- handle E_Incomplete_Subtype entities because the entities in
4615 -- the limited view are always E_Incomplete_Type entities (see
4616 -- Build_Limited_Views). Regarding the expression used to evaluate
4617 -- the scope, it is important to note that the limited view also
4618 -- has shadow entities associated nested packages. For this reason
4619 -- the correct scope of the entity is the scope of the real entity
4620 -- The non-limited view may itself be incomplete, in which case
4621 -- get the full view if available.
4623 elsif From_With_Type (Id)
4624 and then Is_Type (Id)
4625 and then Ekind (Id) = E_Incomplete_Type
4626 and then Present (Non_Limited_View (Id))
4627 and then Scope (Non_Limited_View (Id)) = P_Name
4629 Candidate := Get_Full_View (Non_Limited_View (Id));
4630 Is_New_Candidate := True;
4633 Is_New_Candidate := False;
4636 if Is_New_Candidate then
4637 if Is_Child_Unit (Id) then
4638 exit when Is_Visible_Child_Unit (Id)
4639 or else Is_Immediately_Visible (Id);
4642 exit when not Is_Hidden (Id)
4643 or else Is_Immediately_Visible (Id);
4652 and then (Ekind (P_Name) = E_Procedure
4654 Ekind (P_Name) = E_Function)
4655 and then Is_Generic_Instance (P_Name)
4657 -- Expanded name denotes entity in (instance of) generic subprogram.
4658 -- The entity may be in the subprogram instance, or may denote one of
4659 -- the formals, which is declared in the enclosing wrapper package.
4661 P_Name := Scope (P_Name);
4663 Id := Current_Entity (Selector);
4664 while Present (Id) loop
4665 exit when Scope (Id) = P_Name;
4670 if No (Id) or else Chars (Id) /= Chars (Selector) then
4671 Set_Etype (N, Any_Type);
4673 -- If we are looking for an entity defined in System, try to find it
4674 -- in the child package that may have been provided as an extension
4675 -- to System. The Extend_System pragma will have supplied the name of
4676 -- the extension, which may have to be loaded.
4678 if Chars (P_Name) = Name_System
4679 and then Scope (P_Name) = Standard_Standard
4680 and then Present (System_Extend_Unit)
4681 and then Present_System_Aux (N)
4683 Set_Entity (Prefix (N), System_Aux_Id);
4684 Find_Expanded_Name (N);
4687 elsif Nkind (Selector) = N_Operator_Symbol
4688 and then Has_Implicit_Operator (N)
4690 -- There is an implicit instance of the predefined operator in
4691 -- the given scope. The operator entity is defined in Standard.
4692 -- Has_Implicit_Operator makes the node into an Expanded_Name.
4696 elsif Nkind (Selector) = N_Character_Literal
4697 and then Has_Implicit_Character_Literal (N)
4699 -- If there is no literal defined in the scope denoted by the
4700 -- prefix, the literal may belong to (a type derived from)
4701 -- Standard_Character, for which we have no explicit literals.
4706 -- If the prefix is a single concurrent object, use its name in
4707 -- the error message, rather than that of the anonymous type.
4709 if Is_Concurrent_Type (P_Name)
4710 and then Is_Internal_Name (Chars (P_Name))
4712 Error_Msg_Node_2 := Entity (Prefix (N));
4714 Error_Msg_Node_2 := P_Name;
4717 if P_Name = System_Aux_Id then
4718 P_Name := Scope (P_Name);
4719 Set_Entity (Prefix (N), P_Name);
4722 if Present (Candidate) then
4724 -- If we know that the unit is a child unit we can give a more
4725 -- accurate error message.
4727 if Is_Child_Unit (Candidate) then
4729 -- If the candidate is a private child unit and we are in
4730 -- the visible part of a public unit, specialize the error
4731 -- message. There might be a private with_clause for it,
4732 -- but it is not currently active.
4734 if Is_Private_Descendant (Candidate)
4735 and then Ekind (Current_Scope) = E_Package
4736 and then not In_Private_Part (Current_Scope)
4737 and then not Is_Private_Descendant (Current_Scope)
4739 Error_Msg_N ("private child unit& is not visible here",
4742 -- Normal case where we have a missing with for a child unit
4745 Error_Msg_Qual_Level := 99;
4746 Error_Msg_NE -- CODEFIX
4747 ("missing `WITH &;`", Selector, Candidate);
4748 Error_Msg_Qual_Level := 0;
4751 -- Here we don't know that this is a child unit
4754 Error_Msg_NE ("& is not a visible entity of&", N, Selector);
4758 -- Within the instantiation of a child unit, the prefix may
4759 -- denote the parent instance, but the selector has the name
4760 -- of the original child. Find whether we are within the
4761 -- corresponding instance, and get the proper entity, which
4762 -- can only be an enclosing scope.
4765 and then In_Open_Scopes (P_Name)
4766 and then Is_Generic_Instance (P_Name)
4769 S : Entity_Id := Current_Scope;
4773 for J in reverse 0 .. Scope_Stack.Last loop
4774 S := Scope_Stack.Table (J).Entity;
4776 exit when S = Standard_Standard;
4778 if Ekind_In (S, E_Function,
4782 P := Generic_Parent (Specification
4783 (Unit_Declaration_Node (S)));
4786 and then Chars (Scope (P)) = Chars (O_Name)
4787 and then Chars (P) = Chars (Selector)
4798 -- If this is a selection from Ada, System or Interfaces, then
4799 -- we assume a missing with for the corresponding package.
4801 if Is_Known_Unit (N) then
4802 if not Error_Posted (N) then
4803 Error_Msg_Node_2 := Selector;
4804 Error_Msg_N -- CODEFIX
4805 ("missing `WITH &.&;`", Prefix (N));
4808 -- If this is a selection from a dummy package, then suppress
4809 -- the error message, of course the entity is missing if the
4810 -- package is missing!
4812 elsif Sloc (Error_Msg_Node_2) = No_Location then
4815 -- Here we have the case of an undefined component
4819 -- The prefix may hide a homonym in the context that
4820 -- declares the desired entity. This error can use a
4821 -- specialized message.
4823 if In_Open_Scopes (P_Name)
4824 and then Present (Homonym (P_Name))
4825 and then Is_Compilation_Unit (Homonym (P_Name))
4827 (Is_Immediately_Visible (Homonym (P_Name))
4828 or else Is_Visible_Child_Unit (Homonym (P_Name)))
4831 H : constant Entity_Id := Homonym (P_Name);
4834 Id := First_Entity (H);
4835 while Present (Id) loop
4836 if Chars (Id) = Chars (Selector) then
4837 Error_Msg_Qual_Level := 99;
4838 Error_Msg_Name_1 := Chars (Selector);
4840 ("% not declared in&", N, P_Name);
4842 ("\use fully qualified name starting with"
4843 & " Standard to make& visible", N, H);
4844 Error_Msg_Qual_Level := 0;
4851 -- If not found, standard error message.
4853 Error_Msg_NE ("& not declared in&", N, Selector);
4859 Error_Msg_NE ("& not declared in&", N, Selector);
4862 -- Check for misspelling of some entity in prefix
4864 Id := First_Entity (P_Name);
4865 while Present (Id) loop
4866 if Is_Bad_Spelling_Of (Chars (Id), Chars (Selector))
4867 and then not Is_Internal_Name (Chars (Id))
4869 Error_Msg_NE -- CODEFIX
4870 ("possible misspelling of&", Selector, Id);
4877 -- Specialize the message if this may be an instantiation
4878 -- of a child unit that was not mentioned in the context.
4880 if Nkind (Parent (N)) = N_Package_Instantiation
4881 and then Is_Generic_Instance (Entity (Prefix (N)))
4882 and then Is_Compilation_Unit
4883 (Generic_Parent (Parent (Entity (Prefix (N)))))
4885 Error_Msg_Node_2 := Selector;
4886 Error_Msg_N -- CODEFIX
4887 ("\missing `WITH &.&;`", Prefix (N));
4897 if Comes_From_Source (N)
4898 and then Is_Remote_Access_To_Subprogram_Type (Id)
4899 and then Present (Equivalent_Type (Id))
4901 -- If we are not actually generating distribution code (i.e. the
4902 -- current PCS is the dummy non-distributed version), then the
4903 -- Equivalent_Type will be missing, and Id should be treated as
4904 -- a regular access-to-subprogram type.
4906 Id := Equivalent_Type (Id);
4907 Set_Chars (Selector, Chars (Id));
4910 -- Ada 2005 (AI-50217): Check usage of entities in limited withed units
4912 if Ekind (P_Name) = E_Package
4913 and then From_With_Type (P_Name)
4915 if From_With_Type (Id)
4916 or else Is_Type (Id)
4917 or else Ekind (Id) = E_Package
4922 ("limited withed package can only be used to access "
4923 & "incomplete types",
4928 if Is_Task_Type (P_Name)
4929 and then ((Ekind (Id) = E_Entry
4930 and then Nkind (Parent (N)) /= N_Attribute_Reference)
4932 (Ekind (Id) = E_Entry_Family
4934 Nkind (Parent (Parent (N))) /= N_Attribute_Reference))
4936 -- It is an entry call after all, either to the current task (which
4937 -- will deadlock) or to an enclosing task.
4939 Analyze_Selected_Component (N);
4943 Change_Selected_Component_To_Expanded_Name (N);
4945 -- Do style check and generate reference, but skip both steps if this
4946 -- entity has homonyms, since we may not have the right homonym set yet.
4947 -- The proper homonym will be set during the resolve phase.
4949 if Has_Homonym (Id) then
4952 Set_Entity_Or_Discriminal (N, Id);
4953 Generate_Reference (Id, N);
4956 if Is_Type (Id) then
4959 Set_Etype (N, Get_Full_View (Etype (Id)));
4962 -- If the Ekind of the entity is Void, it means that all homonyms are
4963 -- hidden from all visibility (RM 8.3(5,14-20)).
4965 if Ekind (Id) = E_Void then
4966 Premature_Usage (N);
4968 elsif Is_Overloadable (Id)
4969 and then Present (Homonym (Id))
4972 H : Entity_Id := Homonym (Id);
4975 while Present (H) loop
4976 if Scope (H) = Scope (Id)
4979 or else Is_Immediately_Visible (H))
4981 Collect_Interps (N);
4988 -- If an extension of System is present, collect possible explicit
4989 -- overloadings declared in the extension.
4991 if Chars (P_Name) = Name_System
4992 and then Scope (P_Name) = Standard_Standard
4993 and then Present (System_Extend_Unit)
4994 and then Present_System_Aux (N)
4996 H := Current_Entity (Id);
4998 while Present (H) loop
4999 if Scope (H) = System_Aux_Id then
5000 Add_One_Interp (N, H, Etype (H));
5009 if Nkind (Selector_Name (N)) = N_Operator_Symbol
5010 and then Scope (Id) /= Standard_Standard
5012 -- In addition to user-defined operators in the given scope, there
5013 -- may be an implicit instance of the predefined operator. The
5014 -- operator (defined in Standard) is found in Has_Implicit_Operator,
5015 -- and added to the interpretations. Procedure Add_One_Interp will
5016 -- determine which hides which.
5018 if Has_Implicit_Operator (N) then
5022 end Find_Expanded_Name;
5024 -------------------------
5025 -- Find_Renamed_Entity --
5026 -------------------------
5028 function Find_Renamed_Entity
5032 Is_Actual : Boolean := False) return Entity_Id
5035 I1 : Interp_Index := 0; -- Suppress junk warnings
5041 function Enclosing_Instance return Entity_Id;
5042 -- If the renaming determines the entity for the default of a formal
5043 -- subprogram nested within another instance, choose the innermost
5044 -- candidate. This is because if the formal has a box, and we are within
5045 -- an enclosing instance where some candidate interpretations are local
5046 -- to this enclosing instance, we know that the default was properly
5047 -- resolved when analyzing the generic, so we prefer the local
5048 -- candidates to those that are external. This is not always the case
5049 -- but is a reasonable heuristic on the use of nested generics. The
5050 -- proper solution requires a full renaming model.
5052 function Is_Visible_Operation (Op : Entity_Id) return Boolean;
5053 -- If the renamed entity is an implicit operator, check whether it is
5054 -- visible because its operand type is properly visible. This check
5055 -- applies to explicit renamed entities that appear in the source in a
5056 -- renaming declaration or a formal subprogram instance, but not to
5057 -- default generic actuals with a name.
5059 function Report_Overload return Entity_Id;
5060 -- List possible interpretations, and specialize message in the
5061 -- case of a generic actual.
5063 function Within (Inner, Outer : Entity_Id) return Boolean;
5064 -- Determine whether a candidate subprogram is defined within the
5065 -- enclosing instance. If yes, it has precedence over outer candidates.
5067 ------------------------
5068 -- Enclosing_Instance --
5069 ------------------------
5071 function Enclosing_Instance return Entity_Id is
5075 if not Is_Generic_Instance (Current_Scope)
5076 and then not Is_Actual
5081 S := Scope (Current_Scope);
5082 while S /= Standard_Standard loop
5083 if Is_Generic_Instance (S) then
5091 end Enclosing_Instance;
5093 --------------------------
5094 -- Is_Visible_Operation --
5095 --------------------------
5097 function Is_Visible_Operation (Op : Entity_Id) return Boolean is
5103 if Ekind (Op) /= E_Operator
5104 or else Scope (Op) /= Standard_Standard
5105 or else (In_Instance
5108 or else Present (Enclosing_Instance)))
5113 -- For a fixed point type operator, check the resulting type,
5114 -- because it may be a mixed mode integer * fixed operation.
5116 if Present (Next_Formal (First_Formal (New_S)))
5117 and then Is_Fixed_Point_Type (Etype (New_S))
5119 Typ := Etype (New_S);
5121 Typ := Etype (First_Formal (New_S));
5124 Btyp := Base_Type (Typ);
5126 if Nkind (Nam) /= N_Expanded_Name then
5127 return (In_Open_Scopes (Scope (Btyp))
5128 or else Is_Potentially_Use_Visible (Btyp)
5129 or else In_Use (Btyp)
5130 or else In_Use (Scope (Btyp)));
5133 Scop := Entity (Prefix (Nam));
5135 if Ekind (Scop) = E_Package
5136 and then Present (Renamed_Object (Scop))
5138 Scop := Renamed_Object (Scop);
5141 -- Operator is visible if prefix of expanded name denotes
5142 -- scope of type, or else type is defined in System_Aux
5143 -- and the prefix denotes System.
5145 return Scope (Btyp) = Scop
5146 or else (Scope (Btyp) = System_Aux_Id
5147 and then Scope (Scope (Btyp)) = Scop);
5150 end Is_Visible_Operation;
5156 function Within (Inner, Outer : Entity_Id) return Boolean is
5160 Sc := Scope (Inner);
5161 while Sc /= Standard_Standard loop
5172 ---------------------
5173 -- Report_Overload --
5174 ---------------------
5176 function Report_Overload return Entity_Id is
5179 Error_Msg_NE -- CODEFIX
5180 ("ambiguous actual subprogram&, " &
5181 "possible interpretations:", N, Nam);
5183 Error_Msg_N -- CODEFIX
5184 ("ambiguous subprogram, " &
5185 "possible interpretations:", N);
5188 List_Interps (Nam, N);
5190 end Report_Overload;
5192 -- Start of processing for Find_Renamed_Entry
5196 Candidate_Renaming := Empty;
5198 if not Is_Overloaded (Nam) then
5199 if Entity_Matches_Spec (Entity (Nam), New_S) then
5200 Candidate_Renaming := New_S;
5202 if Is_Visible_Operation (Entity (Nam)) then
5203 Old_S := Entity (Nam);
5207 Present (First_Formal (Entity (Nam)))
5208 and then Present (First_Formal (New_S))
5209 and then (Base_Type (Etype (First_Formal (Entity (Nam))))
5210 = Base_Type (Etype (First_Formal (New_S))))
5212 Candidate_Renaming := Entity (Nam);
5216 Get_First_Interp (Nam, Ind, It);
5217 while Present (It.Nam) loop
5218 if Entity_Matches_Spec (It.Nam, New_S)
5219 and then Is_Visible_Operation (It.Nam)
5221 if Old_S /= Any_Id then
5223 -- Note: The call to Disambiguate only happens if a
5224 -- previous interpretation was found, in which case I1
5225 -- has received a value.
5227 It1 := Disambiguate (Nam, I1, Ind, Etype (Old_S));
5229 if It1 = No_Interp then
5230 Inst := Enclosing_Instance;
5232 if Present (Inst) then
5233 if Within (It.Nam, Inst) then
5235 elsif Within (Old_S, Inst) then
5238 return Report_Overload;
5242 return Report_Overload;
5256 Present (First_Formal (It.Nam))
5257 and then Present (First_Formal (New_S))
5258 and then (Base_Type (Etype (First_Formal (It.Nam)))
5259 = Base_Type (Etype (First_Formal (New_S))))
5261 Candidate_Renaming := It.Nam;
5264 Get_Next_Interp (Ind, It);
5267 Set_Entity (Nam, Old_S);
5268 Set_Is_Overloaded (Nam, False);
5272 end Find_Renamed_Entity;
5274 -----------------------------
5275 -- Find_Selected_Component --
5276 -----------------------------
5278 procedure Find_Selected_Component (N : Node_Id) is
5279 P : constant Node_Id := Prefix (N);
5282 -- Entity denoted by prefix
5292 if Nkind (P) = N_Error then
5295 -- If the selector already has an entity, the node has been constructed
5296 -- in the course of expansion, and is known to be valid. Do not verify
5297 -- that it is defined for the type (it may be a private component used
5298 -- in the expansion of record equality).
5300 elsif Present (Entity (Selector_Name (N))) then
5302 or else Etype (N) = Any_Type
5305 Sel_Name : constant Node_Id := Selector_Name (N);
5306 Selector : constant Entity_Id := Entity (Sel_Name);
5310 Set_Etype (Sel_Name, Etype (Selector));
5312 if not Is_Entity_Name (P) then
5316 -- Build an actual subtype except for the first parameter
5317 -- of an init proc, where this actual subtype is by
5318 -- definition incorrect, since the object is uninitialized
5319 -- (and does not even have defined discriminants etc.)
5321 if Is_Entity_Name (P)
5322 and then Ekind (Entity (P)) = E_Function
5324 Nam := New_Copy (P);
5326 if Is_Overloaded (P) then
5327 Save_Interps (P, Nam);
5331 Make_Function_Call (Sloc (P), Name => Nam));
5333 Analyze_Selected_Component (N);
5336 elsif Ekind (Selector) = E_Component
5337 and then (not Is_Entity_Name (P)
5338 or else Chars (Entity (P)) /= Name_uInit)
5341 Build_Actual_Subtype_Of_Component (
5342 Etype (Selector), N);
5347 if No (C_Etype) then
5348 C_Etype := Etype (Selector);
5350 Insert_Action (N, C_Etype);
5351 C_Etype := Defining_Identifier (C_Etype);
5354 Set_Etype (N, C_Etype);
5357 -- If this is the name of an entry or protected operation, and
5358 -- the prefix is an access type, insert an explicit dereference,
5359 -- so that entry calls are treated uniformly.
5361 if Is_Access_Type (Etype (P))
5362 and then Is_Concurrent_Type (Designated_Type (Etype (P)))
5365 New_P : constant Node_Id :=
5366 Make_Explicit_Dereference (Sloc (P),
5367 Prefix => Relocate_Node (P));
5370 Set_Etype (P, Designated_Type (Etype (Prefix (P))));
5374 -- If the selected component appears within a default expression
5375 -- and it has an actual subtype, the pre-analysis has not yet
5376 -- completed its analysis, because Insert_Actions is disabled in
5377 -- that context. Within the init proc of the enclosing type we
5378 -- must complete this analysis, if an actual subtype was created.
5380 elsif Inside_Init_Proc then
5382 Typ : constant Entity_Id := Etype (N);
5383 Decl : constant Node_Id := Declaration_Node (Typ);
5385 if Nkind (Decl) = N_Subtype_Declaration
5386 and then not Analyzed (Decl)
5387 and then Is_List_Member (Decl)
5388 and then No (Parent (Decl))
5391 Insert_Action (N, Decl);
5398 elsif Is_Entity_Name (P) then
5399 P_Name := Entity (P);
5401 -- The prefix may denote an enclosing type which is the completion
5402 -- of an incomplete type declaration.
5404 if Is_Type (P_Name) then
5405 Set_Entity (P, Get_Full_View (P_Name));
5406 Set_Etype (P, Entity (P));
5407 P_Name := Entity (P);
5410 P_Type := Base_Type (Etype (P));
5412 if Debug_Flag_E then
5413 Write_Str ("Found prefix type to be ");
5414 Write_Entity_Info (P_Type, " "); Write_Eol;
5417 -- First check for components of a record object (not the
5418 -- result of a call, which is handled below).
5420 if Is_Appropriate_For_Record (P_Type)
5421 and then not Is_Overloadable (P_Name)
5422 and then not Is_Type (P_Name)
5424 -- Selected component of record. Type checking will validate
5425 -- name of selector.
5426 -- ??? could we rewrite an implicit dereference into an explicit
5429 Analyze_Selected_Component (N);
5431 elsif Is_Appropriate_For_Entry_Prefix (P_Type)
5432 and then not In_Open_Scopes (P_Name)
5433 and then (not Is_Concurrent_Type (Etype (P_Name))
5434 or else not In_Open_Scopes (Etype (P_Name)))
5436 -- Call to protected operation or entry. Type checking is
5437 -- needed on the prefix.
5439 Analyze_Selected_Component (N);
5441 elsif (In_Open_Scopes (P_Name)
5442 and then Ekind (P_Name) /= E_Void
5443 and then not Is_Overloadable (P_Name))
5444 or else (Is_Concurrent_Type (Etype (P_Name))
5445 and then In_Open_Scopes (Etype (P_Name)))
5447 -- Prefix denotes an enclosing loop, block, or task, i.e. an
5448 -- enclosing construct that is not a subprogram or accept.
5450 Find_Expanded_Name (N);
5452 elsif Ekind (P_Name) = E_Package then
5453 Find_Expanded_Name (N);
5455 elsif Is_Overloadable (P_Name) then
5457 -- The subprogram may be a renaming (of an enclosing scope) as
5458 -- in the case of the name of the generic within an instantiation.
5460 if (Ekind (P_Name) = E_Procedure
5461 or else Ekind (P_Name) = E_Function)
5462 and then Present (Alias (P_Name))
5463 and then Is_Generic_Instance (Alias (P_Name))
5465 P_Name := Alias (P_Name);
5468 if Is_Overloaded (P) then
5470 -- The prefix must resolve to a unique enclosing construct
5473 Found : Boolean := False;
5478 Get_First_Interp (P, Ind, It);
5479 while Present (It.Nam) loop
5480 if In_Open_Scopes (It.Nam) then
5483 "prefix must be unique enclosing scope", N);
5484 Set_Entity (N, Any_Id);
5485 Set_Etype (N, Any_Type);
5494 Get_Next_Interp (Ind, It);
5499 if In_Open_Scopes (P_Name) then
5500 Set_Entity (P, P_Name);
5501 Set_Is_Overloaded (P, False);
5502 Find_Expanded_Name (N);
5505 -- If no interpretation as an expanded name is possible, it
5506 -- must be a selected component of a record returned by a
5507 -- function call. Reformat prefix as a function call, the rest
5508 -- is done by type resolution. If the prefix is procedure or
5509 -- entry, as is P.X; this is an error.
5511 if Ekind (P_Name) /= E_Function
5512 and then (not Is_Overloaded (P)
5514 Nkind (Parent (N)) = N_Procedure_Call_Statement)
5516 -- Prefix may mention a package that is hidden by a local
5517 -- declaration: let the user know. Scan the full homonym
5518 -- chain, the candidate package may be anywhere on it.
5520 if Present (Homonym (Current_Entity (P_Name))) then
5522 P_Name := Current_Entity (P_Name);
5524 while Present (P_Name) loop
5525 exit when Ekind (P_Name) = E_Package;
5526 P_Name := Homonym (P_Name);
5529 if Present (P_Name) then
5530 Error_Msg_Sloc := Sloc (Entity (Prefix (N)));
5533 ("package& is hidden by declaration#",
5536 Set_Entity (Prefix (N), P_Name);
5537 Find_Expanded_Name (N);
5540 P_Name := Entity (Prefix (N));
5545 ("invalid prefix in selected component&", N, P_Name);
5546 Change_Selected_Component_To_Expanded_Name (N);
5547 Set_Entity (N, Any_Id);
5548 Set_Etype (N, Any_Type);
5551 Nam := New_Copy (P);
5552 Save_Interps (P, Nam);
5554 Make_Function_Call (Sloc (P), Name => Nam));
5556 Analyze_Selected_Component (N);
5560 -- Remaining cases generate various error messages
5563 -- Format node as expanded name, to avoid cascaded errors
5565 Change_Selected_Component_To_Expanded_Name (N);
5566 Set_Entity (N, Any_Id);
5567 Set_Etype (N, Any_Type);
5569 -- Issue error message, but avoid this if error issued already.
5570 -- Use identifier of prefix if one is available.
5572 if P_Name = Any_Id then
5575 elsif Ekind (P_Name) = E_Void then
5576 Premature_Usage (P);
5578 elsif Nkind (P) /= N_Attribute_Reference then
5580 "invalid prefix in selected component&", P);
5582 if Is_Access_Type (P_Type)
5583 and then Ekind (Designated_Type (P_Type)) = E_Incomplete_Type
5586 ("\dereference must not be of an incomplete type " &
5592 "invalid prefix in selected component", P);
5597 -- If prefix is not the name of an entity, it must be an expression,
5598 -- whose type is appropriate for a record. This is determined by
5601 Analyze_Selected_Component (N);
5603 end Find_Selected_Component;
5609 procedure Find_Type (N : Node_Id) is
5619 elsif Nkind (N) = N_Attribute_Reference then
5621 -- Class attribute. This is not valid in Ada 83 mode, but we do not
5622 -- need to enforce that at this point, since the declaration of the
5623 -- tagged type in the prefix would have been flagged already.
5625 if Attribute_Name (N) = Name_Class then
5626 Check_Restriction (No_Dispatch, N);
5627 Find_Type (Prefix (N));
5629 -- Propagate error from bad prefix
5631 if Etype (Prefix (N)) = Any_Type then
5632 Set_Entity (N, Any_Type);
5633 Set_Etype (N, Any_Type);
5637 T := Base_Type (Entity (Prefix (N)));
5639 -- Case where type is not known to be tagged. Its appearance in
5640 -- the prefix of the 'Class attribute indicates that the full view
5643 if not Is_Tagged_Type (T) then
5644 if Ekind (T) = E_Incomplete_Type then
5646 -- It is legal to denote the class type of an incomplete
5647 -- type. The full type will have to be tagged, of course.
5648 -- In Ada 2005 this usage is declared obsolescent, so we
5649 -- warn accordingly. This usage is only legal if the type
5650 -- is completed in the current scope, and not for a limited
5653 if not Is_Tagged_Type (T)
5654 and then Ada_Version >= Ada_05
5656 if From_With_Type (T) then
5658 ("prefix of Class attribute must be tagged", N);
5659 Set_Etype (N, Any_Type);
5660 Set_Entity (N, Any_Type);
5663 -- ??? This test is temporarily disabled (always False)
5664 -- because it causes an unwanted warning on GNAT sources
5665 -- (built with -gnatg, which includes Warn_On_Obsolescent_
5666 -- Feature). Once this issue is cleared in the sources, it
5669 elsif Warn_On_Obsolescent_Feature
5673 ("applying 'Class to an untagged incomplete type"
5674 & " is an obsolescent feature (RM J.11)", N);
5678 Set_Is_Tagged_Type (T);
5679 Set_Primitive_Operations (T, New_Elmt_List);
5680 Make_Class_Wide_Type (T);
5681 Set_Entity (N, Class_Wide_Type (T));
5682 Set_Etype (N, Class_Wide_Type (T));
5684 elsif Ekind (T) = E_Private_Type
5685 and then not Is_Generic_Type (T)
5686 and then In_Private_Part (Scope (T))
5688 -- The Class attribute can be applied to an untagged private
5689 -- type fulfilled by a tagged type prior to the full type
5690 -- declaration (but only within the parent package's private
5691 -- part). Create the class-wide type now and check that the
5692 -- full type is tagged later during its analysis. Note that
5693 -- we do not mark the private type as tagged, unlike the
5694 -- case of incomplete types, because the type must still
5695 -- appear untagged to outside units.
5697 if No (Class_Wide_Type (T)) then
5698 Make_Class_Wide_Type (T);
5701 Set_Entity (N, Class_Wide_Type (T));
5702 Set_Etype (N, Class_Wide_Type (T));
5705 -- Should we introduce a type Any_Tagged and use Wrong_Type
5706 -- here, it would be a bit more consistent???
5709 ("tagged type required, found}",
5710 Prefix (N), First_Subtype (T));
5711 Set_Entity (N, Any_Type);
5715 -- Case of tagged type
5718 if Is_Concurrent_Type (T) then
5719 if No (Corresponding_Record_Type (Entity (Prefix (N)))) then
5721 -- Previous error. Use current type, which at least
5722 -- provides some operations.
5724 C := Entity (Prefix (N));
5727 C := Class_Wide_Type
5728 (Corresponding_Record_Type (Entity (Prefix (N))));
5732 C := Class_Wide_Type (Entity (Prefix (N)));
5735 Set_Entity_With_Style_Check (N, C);
5736 Generate_Reference (C, N);
5740 -- Base attribute, not allowed in Ada 83
5742 elsif Attribute_Name (N) = Name_Base then
5743 if Ada_Version = Ada_83 and then Comes_From_Source (N) then
5745 ("(Ada 83) Base attribute not allowed in subtype mark", N);
5748 Find_Type (Prefix (N));
5749 Typ := Entity (Prefix (N));
5751 if Ada_Version >= Ada_95
5752 and then not Is_Scalar_Type (Typ)
5753 and then not Is_Generic_Type (Typ)
5756 ("prefix of Base attribute must be scalar type",
5759 elsif Sloc (Typ) = Standard_Location
5760 and then Base_Type (Typ) = Typ
5761 and then Warn_On_Redundant_Constructs
5763 Error_Msg_NE -- CODEFIX
5764 ("?redundant attribute, & is its own base type", N, Typ);
5767 T := Base_Type (Typ);
5769 -- Rewrite attribute reference with type itself (see similar
5770 -- processing in Analyze_Attribute, case Base). Preserve
5771 -- prefix if present, for other legality checks.
5773 if Nkind (Prefix (N)) = N_Expanded_Name then
5775 Make_Expanded_Name (Sloc (N),
5777 Prefix => New_Copy (Prefix (Prefix (N))),
5778 Selector_Name => New_Reference_To (T, Sloc (N))));
5781 Rewrite (N, New_Reference_To (T, Sloc (N)));
5788 elsif Attribute_Name (N) = Name_Stub_Type then
5790 -- This is handled in Analyze_Attribute
5794 -- All other attributes are invalid in a subtype mark
5797 Error_Msg_N ("invalid attribute in subtype mark", N);
5803 if Is_Entity_Name (N) then
5804 T_Name := Entity (N);
5806 Error_Msg_N ("subtype mark required in this context", N);
5807 Set_Etype (N, Any_Type);
5811 if T_Name = Any_Id or else Etype (N) = Any_Type then
5813 -- Undefined id. Make it into a valid type
5815 Set_Entity (N, Any_Type);
5817 elsif not Is_Type (T_Name)
5818 and then T_Name /= Standard_Void_Type
5820 Error_Msg_Sloc := Sloc (T_Name);
5821 Error_Msg_N ("subtype mark required in this context", N);
5822 Error_Msg_NE ("\\found & declared#", N, T_Name);
5823 Set_Entity (N, Any_Type);
5826 -- If the type is an incomplete type created to handle
5827 -- anonymous access components of a record type, then the
5828 -- incomplete type is the visible entity and subsequent
5829 -- references will point to it. Mark the original full
5830 -- type as referenced, to prevent spurious warnings.
5832 if Is_Incomplete_Type (T_Name)
5833 and then Present (Full_View (T_Name))
5834 and then not Comes_From_Source (T_Name)
5836 Set_Referenced (Full_View (T_Name));
5839 T_Name := Get_Full_View (T_Name);
5841 -- Ada 2005 (AI-251, AI-50217): Handle interfaces visible through
5842 -- limited-with clauses
5844 if From_With_Type (T_Name)
5845 and then Ekind (T_Name) in Incomplete_Kind
5846 and then Present (Non_Limited_View (T_Name))
5847 and then Is_Interface (Non_Limited_View (T_Name))
5849 T_Name := Non_Limited_View (T_Name);
5852 if In_Open_Scopes (T_Name) then
5853 if Ekind (Base_Type (T_Name)) = E_Task_Type then
5855 -- In Ada 2005, a task name can be used in an access
5856 -- definition within its own body. It cannot be used
5857 -- in the discriminant part of the task declaration,
5858 -- nor anywhere else in the declaration because entries
5859 -- cannot have access parameters.
5861 if Ada_Version >= Ada_05
5862 and then Nkind (Parent (N)) = N_Access_Definition
5864 Set_Entity (N, T_Name);
5865 Set_Etype (N, T_Name);
5867 if Has_Completion (T_Name) then
5872 ("task type cannot be used as type mark " &
5873 "within its own declaration", N);
5878 ("task type cannot be used as type mark " &
5879 "within its own spec or body", N);
5882 elsif Ekind (Base_Type (T_Name)) = E_Protected_Type then
5884 -- In Ada 2005, a protected name can be used in an access
5885 -- definition within its own body.
5887 if Ada_Version >= Ada_05
5888 and then Nkind (Parent (N)) = N_Access_Definition
5890 Set_Entity (N, T_Name);
5891 Set_Etype (N, T_Name);
5896 ("protected type cannot be used as type mark " &
5897 "within its own spec or body", N);
5901 Error_Msg_N ("type declaration cannot refer to itself", N);
5904 Set_Etype (N, Any_Type);
5905 Set_Entity (N, Any_Type);
5906 Set_Error_Posted (T_Name);
5910 Set_Entity (N, T_Name);
5911 Set_Etype (N, T_Name);
5915 if Present (Etype (N)) and then Comes_From_Source (N) then
5916 if Is_Fixed_Point_Type (Etype (N)) then
5917 Check_Restriction (No_Fixed_Point, N);
5918 elsif Is_Floating_Point_Type (Etype (N)) then
5919 Check_Restriction (No_Floating_Point, N);
5924 ------------------------------------
5925 -- Has_Implicit_Character_Literal --
5926 ------------------------------------
5928 function Has_Implicit_Character_Literal (N : Node_Id) return Boolean is
5930 Found : Boolean := False;
5931 P : constant Entity_Id := Entity (Prefix (N));
5932 Priv_Id : Entity_Id := Empty;
5935 if Ekind (P) = E_Package
5936 and then not In_Open_Scopes (P)
5938 Priv_Id := First_Private_Entity (P);
5941 if P = Standard_Standard then
5942 Change_Selected_Component_To_Expanded_Name (N);
5943 Rewrite (N, Selector_Name (N));
5945 Set_Etype (Original_Node (N), Standard_Character);
5949 Id := First_Entity (P);
5951 and then Id /= Priv_Id
5953 if Is_Standard_Character_Type (Id)
5954 and then Id = Base_Type (Id)
5956 -- We replace the node with the literal itself, resolve as a
5957 -- character, and set the type correctly.
5960 Change_Selected_Component_To_Expanded_Name (N);
5961 Rewrite (N, Selector_Name (N));
5964 Set_Etype (Original_Node (N), Id);
5968 -- More than one type derived from Character in given scope.
5969 -- Collect all possible interpretations.
5971 Add_One_Interp (N, Id, Id);
5979 end Has_Implicit_Character_Literal;
5981 ----------------------
5982 -- Has_Private_With --
5983 ----------------------
5985 function Has_Private_With (E : Entity_Id) return Boolean is
5986 Comp_Unit : constant Node_Id := Cunit (Current_Sem_Unit);
5990 Item := First (Context_Items (Comp_Unit));
5991 while Present (Item) loop
5992 if Nkind (Item) = N_With_Clause
5993 and then Private_Present (Item)
5994 and then Entity (Name (Item)) = E
6003 end Has_Private_With;
6005 ---------------------------
6006 -- Has_Implicit_Operator --
6007 ---------------------------
6009 function Has_Implicit_Operator (N : Node_Id) return Boolean is
6010 Op_Id : constant Name_Id := Chars (Selector_Name (N));
6011 P : constant Entity_Id := Entity (Prefix (N));
6013 Priv_Id : Entity_Id := Empty;
6015 procedure Add_Implicit_Operator
6017 Op_Type : Entity_Id := Empty);
6018 -- Add implicit interpretation to node N, using the type for which a
6019 -- predefined operator exists. If the operator yields a boolean type,
6020 -- the Operand_Type is implicitly referenced by the operator, and a
6021 -- reference to it must be generated.
6023 ---------------------------
6024 -- Add_Implicit_Operator --
6025 ---------------------------
6027 procedure Add_Implicit_Operator
6029 Op_Type : Entity_Id := Empty)
6031 Predef_Op : Entity_Id;
6034 Predef_Op := Current_Entity (Selector_Name (N));
6036 while Present (Predef_Op)
6037 and then Scope (Predef_Op) /= Standard_Standard
6039 Predef_Op := Homonym (Predef_Op);
6042 if Nkind (N) = N_Selected_Component then
6043 Change_Selected_Component_To_Expanded_Name (N);
6046 -- If the context is an unanalyzed function call, determine whether
6047 -- a binary or unary interpretation is required.
6049 if Nkind (Parent (N)) = N_Indexed_Component then
6051 Is_Binary_Call : constant Boolean :=
6053 (Next (First (Expressions (Parent (N)))));
6054 Is_Binary_Op : constant Boolean :=
6056 (Predef_Op) /= Last_Entity (Predef_Op);
6057 Predef_Op2 : constant Entity_Id := Homonym (Predef_Op);
6060 if Is_Binary_Call then
6061 if Is_Binary_Op then
6062 Add_One_Interp (N, Predef_Op, T);
6064 Add_One_Interp (N, Predef_Op2, T);
6068 if not Is_Binary_Op then
6069 Add_One_Interp (N, Predef_Op, T);
6071 Add_One_Interp (N, Predef_Op2, T);
6077 Add_One_Interp (N, Predef_Op, T);
6079 -- For operators with unary and binary interpretations, if
6080 -- context is not a call, add both
6082 if Present (Homonym (Predef_Op)) then
6083 Add_One_Interp (N, Homonym (Predef_Op), T);
6087 -- The node is a reference to a predefined operator, and
6088 -- an implicit reference to the type of its operands.
6090 if Present (Op_Type) then
6091 Generate_Operator_Reference (N, Op_Type);
6093 Generate_Operator_Reference (N, T);
6095 end Add_Implicit_Operator;
6097 -- Start of processing for Has_Implicit_Operator
6100 if Ekind (P) = E_Package
6101 and then not In_Open_Scopes (P)
6103 Priv_Id := First_Private_Entity (P);
6106 Id := First_Entity (P);
6110 -- Boolean operators: an implicit declaration exists if the scope
6111 -- contains a declaration for a derived Boolean type, or for an
6112 -- array of Boolean type.
6114 when Name_Op_And | Name_Op_Not | Name_Op_Or | Name_Op_Xor =>
6115 while Id /= Priv_Id loop
6116 if Valid_Boolean_Arg (Id)
6117 and then Id = Base_Type (Id)
6119 Add_Implicit_Operator (Id);
6126 -- Equality: look for any non-limited type (result is Boolean)
6128 when Name_Op_Eq | Name_Op_Ne =>
6129 while Id /= Priv_Id loop
6131 and then not Is_Limited_Type (Id)
6132 and then Id = Base_Type (Id)
6134 Add_Implicit_Operator (Standard_Boolean, Id);
6141 -- Comparison operators: scalar type, or array of scalar
6143 when Name_Op_Lt | Name_Op_Le | Name_Op_Gt | Name_Op_Ge =>
6144 while Id /= Priv_Id loop
6145 if (Is_Scalar_Type (Id)
6146 or else (Is_Array_Type (Id)
6147 and then Is_Scalar_Type (Component_Type (Id))))
6148 and then Id = Base_Type (Id)
6150 Add_Implicit_Operator (Standard_Boolean, Id);
6157 -- Arithmetic operators: any numeric type
6167 while Id /= Priv_Id loop
6168 if Is_Numeric_Type (Id)
6169 and then Id = Base_Type (Id)
6171 Add_Implicit_Operator (Id);
6178 -- Concatenation: any one-dimensional array type
6180 when Name_Op_Concat =>
6181 while Id /= Priv_Id loop
6182 if Is_Array_Type (Id) and then Number_Dimensions (Id) = 1
6183 and then Id = Base_Type (Id)
6185 Add_Implicit_Operator (Id);
6192 -- What is the others condition here? Should we be using a
6193 -- subtype of Name_Id that would restrict to operators ???
6195 when others => null;
6198 -- If we fall through, then we do not have an implicit operator
6202 end Has_Implicit_Operator;
6204 --------------------
6205 -- In_Open_Scopes --
6206 --------------------
6208 function In_Open_Scopes (S : Entity_Id) return Boolean is
6210 -- Several scope stacks are maintained by Scope_Stack. The base of the
6211 -- currently active scope stack is denoted by the Is_Active_Stack_Base
6212 -- flag in the scope stack entry. Note that the scope stacks used to
6213 -- simply be delimited implicitly by the presence of Standard_Standard
6214 -- at their base, but there now are cases where this is not sufficient
6215 -- because Standard_Standard actually may appear in the middle of the
6216 -- active set of scopes.
6218 for J in reverse 0 .. Scope_Stack.Last loop
6219 if Scope_Stack.Table (J).Entity = S then
6223 -- Check Is_Active_Stack_Base to tell us when to stop, as there are
6224 -- cases where Standard_Standard appears in the middle of the active
6225 -- set of scopes. This affects the declaration and overriding of
6226 -- private inherited operations in instantiations of generic child
6229 exit when Scope_Stack.Table (J).Is_Active_Stack_Base;
6235 -----------------------------
6236 -- Inherit_Renamed_Profile --
6237 -----------------------------
6239 procedure Inherit_Renamed_Profile (New_S : Entity_Id; Old_S : Entity_Id) is
6246 if Ekind (Old_S) = E_Operator then
6247 New_F := First_Formal (New_S);
6249 while Present (New_F) loop
6250 Set_Etype (New_F, Base_Type (Etype (New_F)));
6251 Next_Formal (New_F);
6254 Set_Etype (New_S, Base_Type (Etype (New_S)));
6257 New_F := First_Formal (New_S);
6258 Old_F := First_Formal (Old_S);
6260 while Present (New_F) loop
6261 New_T := Etype (New_F);
6262 Old_T := Etype (Old_F);
6264 -- If the new type is a renaming of the old one, as is the
6265 -- case for actuals in instances, retain its name, to simplify
6266 -- later disambiguation.
6268 if Nkind (Parent (New_T)) = N_Subtype_Declaration
6269 and then Is_Entity_Name (Subtype_Indication (Parent (New_T)))
6270 and then Entity (Subtype_Indication (Parent (New_T))) = Old_T
6274 Set_Etype (New_F, Old_T);
6277 Next_Formal (New_F);
6278 Next_Formal (Old_F);
6281 if Ekind_In (Old_S, E_Function, E_Enumeration_Literal) then
6282 Set_Etype (New_S, Etype (Old_S));
6285 end Inherit_Renamed_Profile;
6291 procedure Initialize is
6296 -------------------------
6297 -- Install_Use_Clauses --
6298 -------------------------
6300 procedure Install_Use_Clauses
6302 Force_Installation : Boolean := False)
6310 while Present (U) loop
6312 -- Case of USE package
6314 if Nkind (U) = N_Use_Package_Clause then
6315 P := First (Names (U));
6316 while Present (P) loop
6319 if Ekind (Id) = E_Package then
6321 Note_Redundant_Use (P);
6323 elsif Present (Renamed_Object (Id))
6324 and then In_Use (Renamed_Object (Id))
6326 Note_Redundant_Use (P);
6328 elsif Force_Installation or else Applicable_Use (P) then
6329 Use_One_Package (Id, U);
6340 P := First (Subtype_Marks (U));
6341 while Present (P) loop
6342 if not Is_Entity_Name (P)
6343 or else No (Entity (P))
6347 elsif Entity (P) /= Any_Type then
6355 Next_Use_Clause (U);
6357 end Install_Use_Clauses;
6359 -------------------------------------
6360 -- Is_Appropriate_For_Entry_Prefix --
6361 -------------------------------------
6363 function Is_Appropriate_For_Entry_Prefix (T : Entity_Id) return Boolean is
6364 P_Type : Entity_Id := T;
6367 if Is_Access_Type (P_Type) then
6368 P_Type := Designated_Type (P_Type);
6371 return Is_Task_Type (P_Type) or else Is_Protected_Type (P_Type);
6372 end Is_Appropriate_For_Entry_Prefix;
6374 -------------------------------
6375 -- Is_Appropriate_For_Record --
6376 -------------------------------
6378 function Is_Appropriate_For_Record (T : Entity_Id) return Boolean is
6380 function Has_Components (T1 : Entity_Id) return Boolean;
6381 -- Determine if given type has components (i.e. is either a record
6382 -- type or a type that has discriminants).
6384 --------------------
6385 -- Has_Components --
6386 --------------------
6388 function Has_Components (T1 : Entity_Id) return Boolean is
6390 return Is_Record_Type (T1)
6391 or else (Is_Private_Type (T1) and then Has_Discriminants (T1))
6392 or else (Is_Task_Type (T1) and then Has_Discriminants (T1))
6393 or else (Is_Incomplete_Type (T1)
6394 and then From_With_Type (T1)
6395 and then Present (Non_Limited_View (T1))
6396 and then Is_Record_Type
6397 (Get_Full_View (Non_Limited_View (T1))));
6400 -- Start of processing for Is_Appropriate_For_Record
6405 and then (Has_Components (T)
6406 or else (Is_Access_Type (T)
6407 and then Has_Components (Designated_Type (T))));
6408 end Is_Appropriate_For_Record;
6410 ------------------------
6411 -- Note_Redundant_Use --
6412 ------------------------
6414 procedure Note_Redundant_Use (Clause : Node_Id) is
6415 Pack_Name : constant Entity_Id := Entity (Clause);
6416 Cur_Use : constant Node_Id := Current_Use_Clause (Pack_Name);
6417 Decl : constant Node_Id := Parent (Clause);
6419 Prev_Use : Node_Id := Empty;
6420 Redundant : Node_Id := Empty;
6421 -- The Use_Clause which is actually redundant. In the simplest case it
6422 -- is Pack itself, but when we compile a body we install its context
6423 -- before that of its spec, in which case it is the use_clause in the
6424 -- spec that will appear to be redundant, and we want the warning to be
6425 -- placed on the body. Similar complications appear when the redundancy
6426 -- is between a child unit and one of its ancestors.
6429 Set_Redundant_Use (Clause, True);
6431 if not Comes_From_Source (Clause)
6433 or else not Warn_On_Redundant_Constructs
6438 if not Is_Compilation_Unit (Current_Scope) then
6440 -- If the use_clause is in an inner scope, it is made redundant by
6441 -- some clause in the current context, with one exception: If we're
6442 -- compiling a nested package body, and the use_clause comes from the
6443 -- corresponding spec, the clause is not necessarily fully redundant,
6444 -- so we should not warn. If a warning was warranted, it would have
6445 -- been given when the spec was processed.
6447 if Nkind (Parent (Decl)) = N_Package_Specification then
6449 Package_Spec_Entity : constant Entity_Id :=
6450 Defining_Unit_Name (Parent (Decl));
6452 if In_Package_Body (Package_Spec_Entity) then
6458 Redundant := Clause;
6459 Prev_Use := Cur_Use;
6461 elsif Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Body then
6463 Cur_Unit : constant Unit_Number_Type := Get_Source_Unit (Cur_Use);
6464 New_Unit : constant Unit_Number_Type := Get_Source_Unit (Clause);
6468 if Cur_Unit = New_Unit then
6470 -- Redundant clause in same body
6472 Redundant := Clause;
6473 Prev_Use := Cur_Use;
6475 elsif Cur_Unit = Current_Sem_Unit then
6477 -- If the new clause is not in the current unit it has been
6478 -- analyzed first, and it makes the other one redundant.
6479 -- However, if the new clause appears in a subunit, Cur_Unit
6480 -- is still the parent, and in that case the redundant one
6481 -- is the one appearing in the subunit.
6483 if Nkind (Unit (Cunit (New_Unit))) = N_Subunit then
6484 Redundant := Clause;
6485 Prev_Use := Cur_Use;
6487 -- Most common case: redundant clause in body,
6488 -- original clause in spec. Current scope is spec entity.
6493 Unit (Library_Unit (Cunit (Current_Sem_Unit))))
6495 Redundant := Cur_Use;
6499 -- The new clause may appear in an unrelated unit, when
6500 -- the parents of a generic are being installed prior to
6501 -- instantiation. In this case there must be no warning.
6502 -- We detect this case by checking whether the current top
6503 -- of the stack is related to the current compilation.
6505 Scop := Current_Scope;
6506 while Present (Scop)
6507 and then Scop /= Standard_Standard
6509 if Is_Compilation_Unit (Scop)
6510 and then not Is_Child_Unit (Scop)
6514 elsif Scop = Cunit_Entity (Current_Sem_Unit) then
6518 Scop := Scope (Scop);
6521 Redundant := Cur_Use;
6525 elsif New_Unit = Current_Sem_Unit then
6526 Redundant := Clause;
6527 Prev_Use := Cur_Use;
6530 -- Neither is the current unit, so they appear in parent or
6531 -- sibling units. Warning will be emitted elsewhere.
6537 elsif Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Declaration
6538 and then Present (Parent_Spec (Unit (Cunit (Current_Sem_Unit))))
6540 -- Use_clause is in child unit of current unit, and the child unit
6541 -- appears in the context of the body of the parent, so it has been
6542 -- installed first, even though it is the redundant one. Depending on
6543 -- their placement in the context, the visible or the private parts
6544 -- of the two units, either might appear as redundant, but the
6545 -- message has to be on the current unit.
6547 if Get_Source_Unit (Cur_Use) = Current_Sem_Unit then
6548 Redundant := Cur_Use;
6551 Redundant := Clause;
6552 Prev_Use := Cur_Use;
6555 -- If the new use clause appears in the private part of a parent unit
6556 -- it may appear to be redundant w.r.t. a use clause in a child unit,
6557 -- but the previous use clause was needed in the visible part of the
6558 -- child, and no warning should be emitted.
6560 if Nkind (Parent (Decl)) = N_Package_Specification
6562 List_Containing (Decl) = Private_Declarations (Parent (Decl))
6565 Par : constant Entity_Id := Defining_Entity (Parent (Decl));
6566 Spec : constant Node_Id :=
6567 Specification (Unit (Cunit (Current_Sem_Unit)));
6570 if Is_Compilation_Unit (Par)
6571 and then Par /= Cunit_Entity (Current_Sem_Unit)
6572 and then Parent (Cur_Use) = Spec
6574 List_Containing (Cur_Use) = Visible_Declarations (Spec)
6581 -- Finally, if the current use clause is in the context then
6582 -- the clause is redundant when it is nested within the unit.
6584 elsif Nkind (Parent (Cur_Use)) = N_Compilation_Unit
6585 and then Nkind (Parent (Parent (Clause))) /= N_Compilation_Unit
6586 and then Get_Source_Unit (Cur_Use) = Get_Source_Unit (Clause)
6588 Redundant := Clause;
6589 Prev_Use := Cur_Use;
6595 if Present (Redundant) then
6596 Error_Msg_Sloc := Sloc (Prev_Use);
6597 Error_Msg_NE -- CODEFIX
6598 ("& is already use-visible through previous use clause #?",
6599 Redundant, Pack_Name);
6601 end Note_Redundant_Use;
6607 procedure Pop_Scope is
6608 SST : Scope_Stack_Entry renames Scope_Stack.Table (Scope_Stack.Last);
6611 if Debug_Flag_E then
6615 Scope_Suppress := SST.Save_Scope_Suppress;
6616 Local_Suppress_Stack_Top := SST.Save_Local_Suppress_Stack_Top;
6617 Check_Policy_List := SST.Save_Check_Policy_List;
6619 if Debug_Flag_W then
6620 Write_Str ("--> exiting scope: ");
6621 Write_Name (Chars (Current_Scope));
6622 Write_Str (", Depth=");
6623 Write_Int (Int (Scope_Stack.Last));
6627 End_Use_Clauses (SST.First_Use_Clause);
6629 -- If the actions to be wrapped are still there they will get lost
6630 -- causing incomplete code to be generated. It is better to abort in
6631 -- this case (and we do the abort even with assertions off since the
6632 -- penalty is incorrect code generation)
6634 if SST.Actions_To_Be_Wrapped_Before /= No_List
6636 SST.Actions_To_Be_Wrapped_After /= No_List
6641 -- Free last subprogram name if allocated, and pop scope
6643 Free (SST.Last_Subprogram_Name);
6644 Scope_Stack.Decrement_Last;
6651 procedure Push_Scope (S : Entity_Id) is
6655 if Ekind (S) = E_Void then
6658 -- Set scope depth if not a non-concurrent type, and we have not yet set
6659 -- the scope depth. This means that we have the first occurrence of the
6660 -- scope, and this is where the depth is set.
6662 elsif (not Is_Type (S) or else Is_Concurrent_Type (S))
6663 and then not Scope_Depth_Set (S)
6665 if S = Standard_Standard then
6666 Set_Scope_Depth_Value (S, Uint_0);
6668 elsif Is_Child_Unit (S) then
6669 Set_Scope_Depth_Value (S, Uint_1);
6671 elsif not Is_Record_Type (Current_Scope) then
6672 if Ekind (S) = E_Loop then
6673 Set_Scope_Depth_Value (S, Scope_Depth (Current_Scope));
6675 Set_Scope_Depth_Value (S, Scope_Depth (Current_Scope) + 1);
6680 Scope_Stack.Increment_Last;
6683 SST : Scope_Stack_Entry renames Scope_Stack.Table (Scope_Stack.Last);
6687 SST.Save_Scope_Suppress := Scope_Suppress;
6688 SST.Save_Local_Suppress_Stack_Top := Local_Suppress_Stack_Top;
6689 SST.Save_Check_Policy_List := Check_Policy_List;
6691 if Scope_Stack.Last > Scope_Stack.First then
6692 SST.Component_Alignment_Default := Scope_Stack.Table
6693 (Scope_Stack.Last - 1).
6694 Component_Alignment_Default;
6697 SST.Last_Subprogram_Name := null;
6698 SST.Is_Transient := False;
6699 SST.Node_To_Be_Wrapped := Empty;
6700 SST.Pending_Freeze_Actions := No_List;
6701 SST.Actions_To_Be_Wrapped_Before := No_List;
6702 SST.Actions_To_Be_Wrapped_After := No_List;
6703 SST.First_Use_Clause := Empty;
6704 SST.Is_Active_Stack_Base := False;
6705 SST.Previous_Visibility := False;
6708 if Debug_Flag_W then
6709 Write_Str ("--> new scope: ");
6710 Write_Name (Chars (Current_Scope));
6711 Write_Str (", Id=");
6712 Write_Int (Int (Current_Scope));
6713 Write_Str (", Depth=");
6714 Write_Int (Int (Scope_Stack.Last));
6718 -- Deal with copying flags from the previous scope to this one. This is
6719 -- not necessary if either scope is standard, or if the new scope is a
6722 if S /= Standard_Standard
6723 and then Scope (S) /= Standard_Standard
6724 and then not Is_Child_Unit (S)
6728 if Nkind (E) not in N_Entity then
6732 -- Copy categorization flags from Scope (S) to S, this is not done
6733 -- when Scope (S) is Standard_Standard since propagation is from
6734 -- library unit entity inwards. Copy other relevant attributes as
6735 -- well (Discard_Names in particular).
6737 -- We only propagate inwards for library level entities,
6738 -- inner level subprograms do not inherit the categorization.
6740 if Is_Library_Level_Entity (S) then
6741 Set_Is_Preelaborated (S, Is_Preelaborated (E));
6742 Set_Is_Shared_Passive (S, Is_Shared_Passive (E));
6743 Set_Discard_Names (S, Discard_Names (E));
6744 Set_Suppress_Value_Tracking_On_Call
6745 (S, Suppress_Value_Tracking_On_Call (E));
6746 Set_Categorization_From_Scope (E => S, Scop => E);
6751 ---------------------
6752 -- Premature_Usage --
6753 ---------------------
6755 procedure Premature_Usage (N : Node_Id) is
6756 Kind : constant Node_Kind := Nkind (Parent (Entity (N)));
6757 E : Entity_Id := Entity (N);
6760 -- Within an instance, the analysis of the actual for a formal object
6761 -- does not see the name of the object itself. This is significant only
6762 -- if the object is an aggregate, where its analysis does not do any
6763 -- name resolution on component associations. (see 4717-008). In such a
6764 -- case, look for the visible homonym on the chain.
6767 and then Present (Homonym (E))
6772 and then not In_Open_Scopes (Scope (E))
6779 Set_Etype (N, Etype (E));
6784 if Kind = N_Component_Declaration then
6786 ("component&! cannot be used before end of record declaration", N);
6788 elsif Kind = N_Parameter_Specification then
6790 ("formal parameter&! cannot be used before end of specification",
6793 elsif Kind = N_Discriminant_Specification then
6795 ("discriminant&! cannot be used before end of discriminant part",
6798 elsif Kind = N_Procedure_Specification
6799 or else Kind = N_Function_Specification
6802 ("subprogram&! cannot be used before end of its declaration",
6805 elsif Kind = N_Full_Type_Declaration then
6807 ("type& cannot be used before end of its declaration!", N);
6811 ("object& cannot be used before end of its declaration!", N);
6813 end Premature_Usage;
6815 ------------------------
6816 -- Present_System_Aux --
6817 ------------------------
6819 function Present_System_Aux (N : Node_Id := Empty) return Boolean is
6821 Aux_Name : Unit_Name_Type;
6822 Unum : Unit_Number_Type;
6827 function Find_System (C_Unit : Node_Id) return Entity_Id;
6828 -- Scan context clause of compilation unit to find with_clause
6835 function Find_System (C_Unit : Node_Id) return Entity_Id is
6836 With_Clause : Node_Id;
6839 With_Clause := First (Context_Items (C_Unit));
6840 while Present (With_Clause) loop
6841 if (Nkind (With_Clause) = N_With_Clause
6842 and then Chars (Name (With_Clause)) = Name_System)
6843 and then Comes_From_Source (With_Clause)
6854 -- Start of processing for Present_System_Aux
6857 -- The child unit may have been loaded and analyzed already
6859 if Present (System_Aux_Id) then
6862 -- If no previous pragma for System.Aux, nothing to load
6864 elsif No (System_Extend_Unit) then
6867 -- Use the unit name given in the pragma to retrieve the unit.
6868 -- Verify that System itself appears in the context clause of the
6869 -- current compilation. If System is not present, an error will
6870 -- have been reported already.
6873 With_Sys := Find_System (Cunit (Current_Sem_Unit));
6875 The_Unit := Unit (Cunit (Current_Sem_Unit));
6879 (Nkind (The_Unit) = N_Package_Body
6880 or else (Nkind (The_Unit) = N_Subprogram_Body
6882 not Acts_As_Spec (Cunit (Current_Sem_Unit))))
6884 With_Sys := Find_System (Library_Unit (Cunit (Current_Sem_Unit)));
6888 and then Present (N)
6890 -- If we are compiling a subunit, we need to examine its
6891 -- context as well (Current_Sem_Unit is the parent unit);
6893 The_Unit := Parent (N);
6894 while Nkind (The_Unit) /= N_Compilation_Unit loop
6895 The_Unit := Parent (The_Unit);
6898 if Nkind (Unit (The_Unit)) = N_Subunit then
6899 With_Sys := Find_System (The_Unit);
6903 if No (With_Sys) then
6907 Loc := Sloc (With_Sys);
6908 Get_Name_String (Chars (Expression (System_Extend_Unit)));
6909 Name_Buffer (8 .. Name_Len + 7) := Name_Buffer (1 .. Name_Len);
6910 Name_Buffer (1 .. 7) := "system.";
6911 Name_Buffer (Name_Len + 8) := '%';
6912 Name_Buffer (Name_Len + 9) := 's';
6913 Name_Len := Name_Len + 9;
6914 Aux_Name := Name_Find;
6918 (Load_Name => Aux_Name,
6921 Error_Node => With_Sys);
6923 if Unum /= No_Unit then
6924 Semantics (Cunit (Unum));
6926 Defining_Entity (Specification (Unit (Cunit (Unum))));
6929 Make_With_Clause (Loc,
6931 Make_Expanded_Name (Loc,
6932 Chars => Chars (System_Aux_Id),
6933 Prefix => New_Reference_To (Scope (System_Aux_Id), Loc),
6934 Selector_Name => New_Reference_To (System_Aux_Id, Loc)));
6936 Set_Entity (Name (Withn), System_Aux_Id);
6938 Set_Library_Unit (Withn, Cunit (Unum));
6939 Set_Corresponding_Spec (Withn, System_Aux_Id);
6940 Set_First_Name (Withn, True);
6941 Set_Implicit_With (Withn, True);
6943 Insert_After (With_Sys, Withn);
6944 Mark_Rewrite_Insertion (Withn);
6945 Set_Context_Installed (Withn);
6949 -- Here if unit load failed
6952 Error_Msg_Name_1 := Name_System;
6953 Error_Msg_Name_2 := Chars (Expression (System_Extend_Unit));
6955 ("extension package `%.%` does not exist",
6956 Opt.System_Extend_Unit);
6960 end Present_System_Aux;
6962 -------------------------
6963 -- Restore_Scope_Stack --
6964 -------------------------
6966 procedure Restore_Scope_Stack (Handle_Use : Boolean := True) is
6969 Comp_Unit : Node_Id;
6970 In_Child : Boolean := False;
6971 Full_Vis : Boolean := True;
6972 SS_Last : constant Int := Scope_Stack.Last;
6975 -- Restore visibility of previous scope stack, if any
6977 for J in reverse 0 .. Scope_Stack.Last loop
6978 exit when Scope_Stack.Table (J).Entity = Standard_Standard
6979 or else No (Scope_Stack.Table (J).Entity);
6981 S := Scope_Stack.Table (J).Entity;
6983 if not Is_Hidden_Open_Scope (S) then
6985 -- If the parent scope is hidden, its entities are hidden as
6986 -- well, unless the entity is the instantiation currently
6989 if not Is_Hidden_Open_Scope (Scope (S))
6990 or else not Analyzed (Parent (S))
6991 or else Scope (S) = Standard_Standard
6993 Set_Is_Immediately_Visible (S, True);
6996 E := First_Entity (S);
6997 while Present (E) loop
6998 if Is_Child_Unit (E) then
6999 if not From_With_Type (E) then
7000 Set_Is_Immediately_Visible (E,
7001 Is_Visible_Child_Unit (E) or else In_Open_Scopes (E));
7005 (Nkind (Parent (E)) = N_Defining_Program_Unit_Name
7007 Nkind (Parent (Parent (E))) = N_Package_Specification);
7008 Set_Is_Immediately_Visible (E,
7009 Limited_View_Installed (Parent (Parent (E))));
7012 Set_Is_Immediately_Visible (E, True);
7018 and then Is_Package_Or_Generic_Package (S)
7020 -- We are in the visible part of the package scope
7022 exit when E = First_Private_Entity (S);
7026 -- The visibility of child units (siblings of current compilation)
7027 -- must be restored in any case. Their declarations may appear
7028 -- after the private part of the parent.
7030 if not Full_Vis then
7031 while Present (E) loop
7032 if Is_Child_Unit (E) then
7033 Set_Is_Immediately_Visible (E,
7034 Is_Visible_Child_Unit (E) or else In_Open_Scopes (E));
7042 if Is_Child_Unit (S)
7043 and not In_Child -- check only for current unit
7047 -- Restore visibility of parents according to whether the child
7048 -- is private and whether we are in its visible part.
7050 Comp_Unit := Parent (Unit_Declaration_Node (S));
7052 if Nkind (Comp_Unit) = N_Compilation_Unit
7053 and then Private_Present (Comp_Unit)
7057 elsif Is_Package_Or_Generic_Package (S)
7058 and then (In_Private_Part (S) or else In_Package_Body (S))
7062 -- if S is the scope of some instance (which has already been
7063 -- seen on the stack) it does not affect the visibility of
7066 elsif Is_Hidden_Open_Scope (S) then
7069 elsif (Ekind (S) = E_Procedure
7070 or else Ekind (S) = E_Function)
7071 and then Has_Completion (S)
7082 if SS_Last >= Scope_Stack.First
7083 and then Scope_Stack.Table (SS_Last).Entity /= Standard_Standard
7086 Install_Use_Clauses (Scope_Stack.Table (SS_Last).First_Use_Clause);
7088 end Restore_Scope_Stack;
7090 ----------------------
7091 -- Save_Scope_Stack --
7092 ----------------------
7094 procedure Save_Scope_Stack (Handle_Use : Boolean := True) is
7097 SS_Last : constant Int := Scope_Stack.Last;
7100 if SS_Last >= Scope_Stack.First
7101 and then Scope_Stack.Table (SS_Last).Entity /= Standard_Standard
7104 End_Use_Clauses (Scope_Stack.Table (SS_Last).First_Use_Clause);
7107 -- If the call is from within a compilation unit, as when called from
7108 -- Rtsfind, make current entries in scope stack invisible while we
7109 -- analyze the new unit.
7111 for J in reverse 0 .. SS_Last loop
7112 exit when Scope_Stack.Table (J).Entity = Standard_Standard
7113 or else No (Scope_Stack.Table (J).Entity);
7115 S := Scope_Stack.Table (J).Entity;
7116 Set_Is_Immediately_Visible (S, False);
7118 E := First_Entity (S);
7119 while Present (E) loop
7120 Set_Is_Immediately_Visible (E, False);
7126 end Save_Scope_Stack;
7132 procedure Set_Use (L : List_Id) is
7134 Pack_Name : Node_Id;
7141 while Present (Decl) loop
7142 if Nkind (Decl) = N_Use_Package_Clause then
7143 Chain_Use_Clause (Decl);
7145 Pack_Name := First (Names (Decl));
7146 while Present (Pack_Name) loop
7147 Pack := Entity (Pack_Name);
7149 if Ekind (Pack) = E_Package
7150 and then Applicable_Use (Pack_Name)
7152 Use_One_Package (Pack, Decl);
7158 elsif Nkind (Decl) = N_Use_Type_Clause then
7159 Chain_Use_Clause (Decl);
7161 Id := First (Subtype_Marks (Decl));
7162 while Present (Id) loop
7163 if Entity (Id) /= Any_Type then
7176 ---------------------
7177 -- Use_One_Package --
7178 ---------------------
7180 procedure Use_One_Package (P : Entity_Id; N : Node_Id) is
7183 Current_Instance : Entity_Id := Empty;
7185 Private_With_OK : Boolean := False;
7188 if Ekind (P) /= E_Package then
7193 Set_Current_Use_Clause (P, N);
7195 -- Ada 2005 (AI-50217): Check restriction
7197 if From_With_Type (P) then
7198 Error_Msg_N ("limited withed package cannot appear in use clause", N);
7201 -- Find enclosing instance, if any
7204 Current_Instance := Current_Scope;
7205 while not Is_Generic_Instance (Current_Instance) loop
7206 Current_Instance := Scope (Current_Instance);
7209 if No (Hidden_By_Use_Clause (N)) then
7210 Set_Hidden_By_Use_Clause (N, New_Elmt_List);
7214 -- If unit is a package renaming, indicate that the renamed
7215 -- package is also in use (the flags on both entities must
7216 -- remain consistent, and a subsequent use of either of them
7217 -- should be recognized as redundant).
7219 if Present (Renamed_Object (P)) then
7220 Set_In_Use (Renamed_Object (P));
7221 Set_Current_Use_Clause (Renamed_Object (P), N);
7222 Real_P := Renamed_Object (P);
7227 -- Ada 2005 (AI-262): Check the use_clause of a private withed package
7228 -- found in the private part of a package specification
7230 if In_Private_Part (Current_Scope)
7231 and then Has_Private_With (P)
7232 and then Is_Child_Unit (Current_Scope)
7233 and then Is_Child_Unit (P)
7234 and then Is_Ancestor_Package (Scope (Current_Scope), P)
7236 Private_With_OK := True;
7239 -- Loop through entities in one package making them potentially
7242 Id := First_Entity (P);
7244 and then (Id /= First_Private_Entity (P)
7245 or else Private_With_OK) -- Ada 2005 (AI-262)
7247 Prev := Current_Entity (Id);
7248 while Present (Prev) loop
7249 if Is_Immediately_Visible (Prev)
7250 and then (not Is_Overloadable (Prev)
7251 or else not Is_Overloadable (Id)
7252 or else (Type_Conformant (Id, Prev)))
7254 if No (Current_Instance) then
7256 -- Potentially use-visible entity remains hidden
7258 goto Next_Usable_Entity;
7260 -- A use clause within an instance hides outer global entities,
7261 -- which are not used to resolve local entities in the
7262 -- instance. Note that the predefined entities in Standard
7263 -- could not have been hidden in the generic by a use clause,
7264 -- and therefore remain visible. Other compilation units whose
7265 -- entities appear in Standard must be hidden in an instance.
7267 -- To determine whether an entity is external to the instance
7268 -- we compare the scope depth of its scope with that of the
7269 -- current instance. However, a generic actual of a subprogram
7270 -- instance is declared in the wrapper package but will not be
7271 -- hidden by a use-visible entity. similarly, an entity that is
7272 -- declared in an enclosing instance will not be hidden by an
7273 -- an entity declared in a generic actual, which can only have
7274 -- been use-visible in the generic and will not have hidden the
7275 -- entity in the generic parent.
7277 -- If Id is called Standard, the predefined package with the
7278 -- same name is in the homonym chain. It has to be ignored
7279 -- because it has no defined scope (being the only entity in
7280 -- the system with this mandated behavior).
7282 elsif not Is_Hidden (Id)
7283 and then Present (Scope (Prev))
7284 and then not Is_Wrapper_Package (Scope (Prev))
7285 and then Scope_Depth (Scope (Prev)) <
7286 Scope_Depth (Current_Instance)
7287 and then (Scope (Prev) /= Standard_Standard
7288 or else Sloc (Prev) > Standard_Location)
7290 if In_Open_Scopes (Scope (Prev))
7291 and then Is_Generic_Instance (Scope (Prev))
7292 and then Present (Associated_Formal_Package (P))
7297 Set_Is_Potentially_Use_Visible (Id);
7298 Set_Is_Immediately_Visible (Prev, False);
7299 Append_Elmt (Prev, Hidden_By_Use_Clause (N));
7303 -- A user-defined operator is not use-visible if the predefined
7304 -- operator for the type is immediately visible, which is the case
7305 -- if the type of the operand is in an open scope. This does not
7306 -- apply to user-defined operators that have operands of different
7307 -- types, because the predefined mixed mode operations (multiply
7308 -- and divide) apply to universal types and do not hide anything.
7310 elsif Ekind (Prev) = E_Operator
7311 and then Operator_Matches_Spec (Prev, Id)
7312 and then In_Open_Scopes
7313 (Scope (Base_Type (Etype (First_Formal (Id)))))
7314 and then (No (Next_Formal (First_Formal (Id)))
7315 or else Etype (First_Formal (Id))
7316 = Etype (Next_Formal (First_Formal (Id)))
7317 or else Chars (Prev) = Name_Op_Expon)
7319 goto Next_Usable_Entity;
7321 -- In an instance, two homonyms may become use_visible through the
7322 -- actuals of distinct formal packages. In the generic, only the
7323 -- current one would have been visible, so make the other one
7326 elsif Present (Current_Instance)
7327 and then Is_Potentially_Use_Visible (Prev)
7328 and then not Is_Overloadable (Prev)
7329 and then Scope (Id) /= Scope (Prev)
7330 and then Used_As_Generic_Actual (Scope (Prev))
7331 and then Used_As_Generic_Actual (Scope (Id))
7332 and then List_Containing (Current_Use_Clause (Scope (Prev))) /=
7333 List_Containing (Current_Use_Clause (Scope (Id)))
7335 Set_Is_Potentially_Use_Visible (Prev, False);
7336 Append_Elmt (Prev, Hidden_By_Use_Clause (N));
7339 Prev := Homonym (Prev);
7342 -- On exit, we know entity is not hidden, unless it is private
7344 if not Is_Hidden (Id)
7345 and then ((not Is_Child_Unit (Id))
7346 or else Is_Visible_Child_Unit (Id))
7348 Set_Is_Potentially_Use_Visible (Id);
7350 if Is_Private_Type (Id)
7351 and then Present (Full_View (Id))
7353 Set_Is_Potentially_Use_Visible (Full_View (Id));
7357 <<Next_Usable_Entity>>
7361 -- Child units are also made use-visible by a use clause, but they may
7362 -- appear after all visible declarations in the parent entity list.
7364 while Present (Id) loop
7365 if Is_Child_Unit (Id)
7366 and then Is_Visible_Child_Unit (Id)
7368 Set_Is_Potentially_Use_Visible (Id);
7374 if Chars (Real_P) = Name_System
7375 and then Scope (Real_P) = Standard_Standard
7376 and then Present_System_Aux (N)
7378 Use_One_Package (System_Aux_Id, N);
7381 end Use_One_Package;
7387 procedure Use_One_Type (Id : Node_Id) is
7389 Is_Known_Used : Boolean;
7393 function Spec_Reloaded_For_Body return Boolean;
7394 -- Determine whether the compilation unit is a package body and the use
7395 -- type clause is in the spec of the same package. Even though the spec
7396 -- was analyzed first, its context is reloaded when analysing the body.
7398 ----------------------------
7399 -- Spec_Reloaded_For_Body --
7400 ----------------------------
7402 function Spec_Reloaded_For_Body return Boolean is
7404 if Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Body then
7406 Spec : constant Node_Id :=
7407 Parent (List_Containing (Parent (Id)));
7410 Nkind (Spec) = N_Package_Specification
7411 and then Corresponding_Body (Parent (Spec)) =
7412 Cunit_Entity (Current_Sem_Unit);
7417 end Spec_Reloaded_For_Body;
7419 -- Start of processing for Use_One_Type;
7422 -- It is the type determined by the subtype mark (8.4(8)) whose
7423 -- operations become potentially use-visible.
7425 T := Base_Type (Entity (Id));
7427 -- Either the type itself is used, the package where it is declared
7428 -- is in use or the entity is declared in the current package, thus
7433 or else In_Use (Scope (T))
7434 or else Scope (T) = Current_Scope;
7436 Set_Redundant_Use (Id,
7437 Is_Known_Used or else Is_Potentially_Use_Visible (T));
7439 if Ekind (T) = E_Incomplete_Type then
7440 Error_Msg_N ("premature usage of incomplete type", Id);
7442 elsif In_Open_Scopes (Scope (T)) then
7445 -- A limited view cannot appear in a use_type clause. However, an access
7446 -- type whose designated type is limited has the flag but is not itself
7447 -- a limited view unless we only have a limited view of its enclosing
7450 elsif From_With_Type (T)
7451 and then From_With_Type (Scope (T))
7454 ("incomplete type from limited view "
7455 & "cannot appear in use clause", Id);
7457 -- If the subtype mark designates a subtype in a different package,
7458 -- we have to check that the parent type is visible, otherwise the
7459 -- use type clause is a noop. Not clear how to do that???
7461 elsif not Redundant_Use (Id) then
7464 -- If T is tagged, primitive operators on class-wide operands
7465 -- are also available.
7467 if Is_Tagged_Type (T) then
7468 Set_In_Use (Class_Wide_Type (T));
7471 Set_Current_Use_Clause (T, Parent (Id));
7472 Op_List := Collect_Primitive_Operations (T);
7474 Elmt := First_Elmt (Op_List);
7475 while Present (Elmt) loop
7476 if (Nkind (Node (Elmt)) = N_Defining_Operator_Symbol
7477 or else Chars (Node (Elmt)) in Any_Operator_Name)
7478 and then not Is_Hidden (Node (Elmt))
7480 Set_Is_Potentially_Use_Visible (Node (Elmt));
7487 -- If warning on redundant constructs, check for unnecessary WITH
7489 if Warn_On_Redundant_Constructs
7490 and then Is_Known_Used
7492 -- with P; with P; use P;
7493 -- package P is package X is package body X is
7494 -- type T ... use P.T;
7496 -- The compilation unit is the body of X. GNAT first compiles the
7497 -- spec of X, then proceeds to the body. At that point P is marked
7498 -- as use visible. The analysis then reinstalls the spec along with
7499 -- its context. The use clause P.T is now recognized as redundant,
7500 -- but in the wrong context. Do not emit a warning in such cases.
7501 -- Do not emit a warning either if we are in an instance, there is
7502 -- no redundancy between an outer use_clause and one that appears
7503 -- within the generic.
7505 and then not Spec_Reloaded_For_Body
7506 and then not In_Instance
7508 -- The type already has a use clause
7512 -- Case where we know the current use clause for the type
7514 if Present (Current_Use_Clause (T)) then
7515 Use_Clause_Known : declare
7516 Clause1 : constant Node_Id := Parent (Id);
7517 Clause2 : constant Node_Id := Current_Use_Clause (T);
7524 function Entity_Of_Unit (U : Node_Id) return Entity_Id;
7525 -- Return the appropriate entity for determining which unit
7526 -- has a deeper scope: the defining entity for U, unless U
7527 -- is a package instance, in which case we retrieve the
7528 -- entity of the instance spec.
7530 --------------------
7531 -- Entity_Of_Unit --
7532 --------------------
7534 function Entity_Of_Unit (U : Node_Id) return Entity_Id is
7536 if Nkind (U) = N_Package_Instantiation
7537 and then Analyzed (U)
7539 return Defining_Entity (Instance_Spec (U));
7541 return Defining_Entity (U);
7545 -- Start of processing for Use_Clause_Known
7548 -- If both current use type clause and the use type clause
7549 -- for the type are at the compilation unit level, one of
7550 -- the units must be an ancestor of the other, and the
7551 -- warning belongs on the descendant.
7553 if Nkind (Parent (Clause1)) = N_Compilation_Unit
7555 Nkind (Parent (Clause2)) = N_Compilation_Unit
7558 -- If the unit is a subprogram body that acts as spec,
7559 -- the context clause is shared with the constructed
7560 -- subprogram spec. Clearly there is no redundancy.
7562 if Clause1 = Clause2 then
7566 Unit1 := Unit (Parent (Clause1));
7567 Unit2 := Unit (Parent (Clause2));
7569 -- If both clauses are on same unit, or one is the body
7570 -- of the other, or one of them is in a subunit, report
7571 -- redundancy on the later one.
7573 if Unit1 = Unit2 then
7574 Error_Msg_Sloc := Sloc (Current_Use_Clause (T));
7575 Error_Msg_NE -- CODEFIX
7576 ("& is already use-visible through previous "
7577 & "use_type_clause #?", Clause1, T);
7580 elsif Nkind (Unit1) = N_Subunit then
7581 Error_Msg_Sloc := Sloc (Current_Use_Clause (T));
7582 Error_Msg_NE -- CODEFIX
7583 ("& is already use-visible through previous "
7584 & "use_type_clause #?", Clause1, T);
7587 elsif Nkind_In (Unit2, N_Package_Body, N_Subprogram_Body)
7588 and then Nkind (Unit1) /= Nkind (Unit2)
7589 and then Nkind (Unit1) /= N_Subunit
7591 Error_Msg_Sloc := Sloc (Clause1);
7592 Error_Msg_NE -- CODEFIX
7593 ("& is already use-visible through previous "
7594 & "use_type_clause #?", Current_Use_Clause (T), T);
7598 -- There is a redundant use type clause in a child unit.
7599 -- Determine which of the units is more deeply nested.
7600 -- If a unit is a package instance, retrieve the entity
7601 -- and its scope from the instance spec.
7603 Ent1 := Entity_Of_Unit (Unit1);
7604 Ent2 := Entity_Of_Unit (Unit2);
7606 if Scope (Ent2) = Standard_Standard then
7607 Error_Msg_Sloc := Sloc (Current_Use_Clause (T));
7610 elsif Scope (Ent1) = Standard_Standard then
7611 Error_Msg_Sloc := Sloc (Id);
7614 -- If both units are child units, we determine which one
7615 -- is the descendant by the scope distance to the
7616 -- ultimate parent unit.
7625 while S1 /= Standard_Standard
7627 S2 /= Standard_Standard
7633 if S1 = Standard_Standard then
7634 Error_Msg_Sloc := Sloc (Id);
7637 Error_Msg_Sloc := Sloc (Current_Use_Clause (T));
7643 Error_Msg_NE -- CODEFIX
7644 ("& is already use-visible through previous "
7645 & "use_type_clause #?", Err_No, Id);
7647 -- Case where current use type clause and the use type
7648 -- clause for the type are not both at the compilation unit
7649 -- level. In this case we don't have location information.
7652 Error_Msg_NE -- CODEFIX
7653 ("& is already use-visible through previous "
7654 & "use type clause?", Id, T);
7656 end Use_Clause_Known;
7658 -- Here if Current_Use_Clause is not set for T, another case
7659 -- where we do not have the location information available.
7662 Error_Msg_NE -- CODEFIX
7663 ("& is already use-visible through previous "
7664 & "use type clause?", Id, T);
7667 -- The package where T is declared is already used
7669 elsif In_Use (Scope (T)) then
7670 Error_Msg_Sloc := Sloc (Current_Use_Clause (Scope (T)));
7671 Error_Msg_NE -- CODEFIX
7672 ("& is already use-visible through package use clause #?",
7675 -- The current scope is the package where T is declared
7678 Error_Msg_Node_2 := Scope (T);
7679 Error_Msg_NE -- CODEFIX
7680 ("& is already use-visible inside package &?", Id, T);
7689 procedure Write_Info is
7690 Id : Entity_Id := First_Entity (Current_Scope);
7693 -- No point in dumping standard entities
7695 if Current_Scope = Standard_Standard then
7699 Write_Str ("========================================================");
7701 Write_Str (" Defined Entities in ");
7702 Write_Name (Chars (Current_Scope));
7704 Write_Str ("========================================================");
7708 Write_Str ("-- none --");
7712 while Present (Id) loop
7713 Write_Entity_Info (Id, " ");
7718 if Scope (Current_Scope) = Standard_Standard then
7720 -- Print information on the current unit itself
7722 Write_Entity_Info (Current_Scope, " ");
7732 procedure Write_Scopes is
7735 for J in reverse 1 .. Scope_Stack.Last loop
7736 S := Scope_Stack.Table (J).Entity;
7737 Write_Int (Int (S));
7738 Write_Str (" === ");
7739 Write_Name (Chars (S));
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