1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2009, 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
402 -- use clause must be processed. Pack_Name is an entity name that
403 -- references 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 Check_Frozen_Renaming (N : Node_Id; Subp : Entity_Id);
411 -- A renaming_as_body may occur after the entity of the original decla-
412 -- ration has been frozen. In that case, the body of the new entity must
413 -- be built now, because the usual mechanism of building the renamed
414 -- body at the point of freezing will not work. Subp is the subprogram
415 -- for which N provides the Renaming_As_Body.
417 procedure Check_In_Previous_With_Clause
420 -- N is a use_package clause and Nam the package name, or N is a use_type
421 -- clause and Nam is the prefix of the type name. In either case, verify
422 -- that the package is visible at that point in the context: either it
423 -- appears in a previous with_clause, or because it is a fully qualified
424 -- name and the root ancestor appears in a previous with_clause.
426 procedure Check_Library_Unit_Renaming (N : Node_Id; Old_E : Entity_Id);
427 -- Verify that the entity in a renaming declaration that is a library unit
428 -- is itself a library unit and not a nested unit or subunit. Also check
429 -- that if the renaming is a child unit of a generic parent, then the
430 -- renamed unit must also be a child unit of that parent. Finally, verify
431 -- that a renamed generic unit is not an implicit child declared within
432 -- an instance of the parent.
434 procedure Chain_Use_Clause (N : Node_Id);
435 -- Chain use clause onto list of uses clauses headed by First_Use_Clause in
436 -- the proper scope table entry. This is usually the current scope, but it
437 -- will be an inner scope when installing the use clauses of the private
438 -- declarations of a parent unit prior to compiling the private part of a
439 -- child unit. This chain is traversed when installing/removing use clauses
440 -- when compiling a subunit or instantiating a generic body on the fly,
441 -- when it is necessary to save and restore full environments.
443 function Has_Implicit_Character_Literal (N : Node_Id) return Boolean;
444 -- Find a type derived from Character or Wide_Character in the prefix of N.
445 -- Used to resolved qualified names whose selector is a character literal.
447 function Has_Private_With (E : Entity_Id) return Boolean;
448 -- Ada 2005 (AI-262): Determines if the current compilation unit has a
449 -- private with on E.
451 procedure Find_Expanded_Name (N : Node_Id);
452 -- Selected component is known to be expanded name. Verify legality of
453 -- selector given the scope denoted by prefix.
455 function Find_Renamed_Entity
459 Is_Actual : Boolean := False) return Entity_Id;
460 -- Find the renamed entity that corresponds to the given parameter profile
461 -- in a subprogram renaming declaration. The renamed entity may be an
462 -- operator, a subprogram, an entry, or a protected operation. Is_Actual
463 -- indicates that the renaming is the one generated for an actual subpro-
464 -- gram in an instance, for which special visibility checks apply.
466 function Has_Implicit_Operator (N : Node_Id) return Boolean;
467 -- N is an expanded name whose selector is an operator name (e.g. P."+").
468 -- declarative part contains an implicit declaration of an operator if it
469 -- has a declaration of a type to which one of the predefined operators
470 -- apply. The existence of this routine is an implementation artifact. A
471 -- more straightforward but more space-consuming choice would be to make
472 -- all inherited operators explicit in the symbol table.
474 procedure Inherit_Renamed_Profile (New_S : Entity_Id; Old_S : Entity_Id);
475 -- A subprogram defined by a renaming declaration inherits the parameter
476 -- profile of the renamed entity. The subtypes given in the subprogram
477 -- specification are discarded and replaced with those of the renamed
478 -- subprogram, which are then used to recheck the default values.
480 function Is_Appropriate_For_Record (T : Entity_Id) return Boolean;
481 -- Prefix is appropriate for record if it is of a record type, or an access
484 function Is_Appropriate_For_Entry_Prefix (T : Entity_Id) return Boolean;
485 -- True if it is of a task type, a protected type, or else an access to one
488 procedure Note_Redundant_Use (Clause : Node_Id);
489 -- Mark the name in a use clause as redundant if the corresponding entity
490 -- is already use-visible. Emit a warning if the use clause comes from
491 -- source and the proper warnings are enabled.
493 procedure Premature_Usage (N : Node_Id);
494 -- Diagnose usage of an entity before it is visible
496 procedure Use_One_Package (P : Entity_Id; N : Node_Id);
497 -- Make visible entities declared in package P potentially use-visible
498 -- in the current context. Also used in the analysis of subunits, when
499 -- re-installing use clauses of parent units. N is the use_clause that
500 -- names P (and possibly other packages).
502 procedure Use_One_Type (Id : Node_Id);
503 -- Id is the subtype mark from a use type clause. This procedure makes
504 -- the primitive operators of the type potentially use-visible.
506 procedure Write_Info;
507 -- Write debugging information on entities declared in current scope
509 procedure Write_Scopes;
510 pragma Warnings (Off, Write_Scopes);
511 -- Debugging information: dump all entities on scope stack
513 --------------------------------
514 -- Analyze_Exception_Renaming --
515 --------------------------------
517 -- The language only allows a single identifier, but the tree holds an
518 -- identifier list. The parser has already issued an error message if
519 -- there is more than one element in the list.
521 procedure Analyze_Exception_Renaming (N : Node_Id) is
522 Id : constant Node_Id := Defining_Identifier (N);
523 Nam : constant Node_Id := Name (N);
529 Set_Ekind (Id, E_Exception);
530 Set_Exception_Code (Id, Uint_0);
531 Set_Etype (Id, Standard_Exception_Type);
532 Set_Is_Pure (Id, Is_Pure (Current_Scope));
534 if not Is_Entity_Name (Nam) or else
535 Ekind (Entity (Nam)) /= E_Exception
537 Error_Msg_N ("invalid exception name in renaming", Nam);
539 if Present (Renamed_Object (Entity (Nam))) then
540 Set_Renamed_Object (Id, Renamed_Object (Entity (Nam)));
542 Set_Renamed_Object (Id, Entity (Nam));
545 end Analyze_Exception_Renaming;
547 ---------------------------
548 -- Analyze_Expanded_Name --
549 ---------------------------
551 procedure Analyze_Expanded_Name (N : Node_Id) is
553 -- If the entity pointer is already set, this is an internal node, or a
554 -- node that is analyzed more than once, after a tree modification. In
555 -- such a case there is no resolution to perform, just set the type. For
556 -- completeness, analyze prefix as well.
558 if Present (Entity (N)) then
559 if Is_Type (Entity (N)) then
560 Set_Etype (N, Entity (N));
562 Set_Etype (N, Etype (Entity (N)));
565 Analyze (Prefix (N));
568 Find_Expanded_Name (N);
570 end Analyze_Expanded_Name;
572 ---------------------------------------
573 -- Analyze_Generic_Function_Renaming --
574 ---------------------------------------
576 procedure Analyze_Generic_Function_Renaming (N : Node_Id) is
578 Analyze_Generic_Renaming (N, E_Generic_Function);
579 end Analyze_Generic_Function_Renaming;
581 --------------------------------------
582 -- Analyze_Generic_Package_Renaming --
583 --------------------------------------
585 procedure Analyze_Generic_Package_Renaming (N : Node_Id) is
587 -- Apply the Text_IO Kludge here, since we may be renaming one of the
588 -- subpackages of Text_IO, then join common routine.
590 Text_IO_Kludge (Name (N));
592 Analyze_Generic_Renaming (N, E_Generic_Package);
593 end Analyze_Generic_Package_Renaming;
595 ----------------------------------------
596 -- Analyze_Generic_Procedure_Renaming --
597 ----------------------------------------
599 procedure Analyze_Generic_Procedure_Renaming (N : Node_Id) is
601 Analyze_Generic_Renaming (N, E_Generic_Procedure);
602 end Analyze_Generic_Procedure_Renaming;
604 ------------------------------
605 -- Analyze_Generic_Renaming --
606 ------------------------------
608 procedure Analyze_Generic_Renaming
612 New_P : constant Entity_Id := Defining_Entity (N);
614 Inst : Boolean := False; -- prevent junk warning
617 if Name (N) = Error then
621 Generate_Definition (New_P);
623 if Current_Scope /= Standard_Standard then
624 Set_Is_Pure (New_P, Is_Pure (Current_Scope));
627 if Nkind (Name (N)) = N_Selected_Component then
628 Check_Generic_Child_Unit (Name (N), Inst);
633 if not Is_Entity_Name (Name (N)) then
634 Error_Msg_N ("expect entity name in renaming declaration", Name (N));
637 Old_P := Entity (Name (N));
641 Set_Ekind (New_P, K);
643 if Etype (Old_P) = Any_Type then
646 elsif Ekind (Old_P) /= K then
647 Error_Msg_N ("invalid generic unit name", Name (N));
650 if Present (Renamed_Object (Old_P)) then
651 Set_Renamed_Object (New_P, Renamed_Object (Old_P));
653 Set_Renamed_Object (New_P, Old_P);
656 Set_Is_Pure (New_P, Is_Pure (Old_P));
657 Set_Is_Preelaborated (New_P, Is_Preelaborated (Old_P));
659 Set_Etype (New_P, Etype (Old_P));
660 Set_Has_Completion (New_P);
662 if In_Open_Scopes (Old_P) then
663 Error_Msg_N ("within its scope, generic denotes its instance", N);
666 Check_Library_Unit_Renaming (N, Old_P);
668 end Analyze_Generic_Renaming;
670 -----------------------------
671 -- Analyze_Object_Renaming --
672 -----------------------------
674 procedure Analyze_Object_Renaming (N : Node_Id) is
675 Id : constant Entity_Id := Defining_Identifier (N);
677 Nam : constant Node_Id := Name (N);
681 function In_Generic_Scope (E : Entity_Id) return Boolean;
682 -- Determine whether entity E is inside a generic cope
684 ----------------------
685 -- In_Generic_Scope --
686 ----------------------
688 function In_Generic_Scope (E : Entity_Id) return Boolean is
693 while Present (S) and then S /= Standard_Standard loop
694 if Is_Generic_Unit (S) then
702 end In_Generic_Scope;
704 -- Start of processing for Analyze_Object_Renaming
711 Set_Is_Pure (Id, Is_Pure (Current_Scope));
714 -- The renaming of a component that depends on a discriminant requires
715 -- an actual subtype, because in subsequent use of the object Gigi will
716 -- be unable to locate the actual bounds. This explicit step is required
717 -- when the renaming is generated in removing side effects of an
718 -- already-analyzed expression.
720 if Nkind (Nam) = N_Selected_Component
721 and then Analyzed (Nam)
724 Dec := Build_Actual_Subtype_Of_Component (Etype (Nam), Nam);
726 if Present (Dec) then
727 Insert_Action (N, Dec);
728 T := Defining_Identifier (Dec);
732 -- Complete analysis of the subtype mark in any case, for ASIS use
734 if Present (Subtype_Mark (N)) then
735 Find_Type (Subtype_Mark (N));
738 elsif Present (Subtype_Mark (N)) then
739 Find_Type (Subtype_Mark (N));
740 T := Entity (Subtype_Mark (N));
743 if Nkind (Nam) = N_Type_Conversion
744 and then not Is_Tagged_Type (T)
747 ("renaming of conversion only allowed for tagged types", Nam);
752 -- Check that a class-wide object is not being renamed as an object
753 -- of a specific type. The test for access types is needed to exclude
754 -- cases where the renamed object is a dynamically tagged access
755 -- result, such as occurs in certain expansions.
757 if (Is_Class_Wide_Type (Etype (Nam))
758 or else (Is_Dynamically_Tagged (Nam)
759 and then not Is_Access_Type (T)))
760 and then not Is_Class_Wide_Type (T)
762 Error_Msg_N ("dynamically tagged expression not allowed!", Nam);
765 -- Ada 2005 (AI-230/AI-254): Access renaming
767 else pragma Assert (Present (Access_Definition (N)));
768 T := Access_Definition
770 N => Access_Definition (N));
774 -- Ada 2005 AI05-105: if the declaration has an anonymous access
775 -- type, the renamed object must also have an anonymous type, and
776 -- this is a name resolution rule. This was implicit in the last
777 -- part of the first sentence in 8.5.1.(3/2), and is made explicit
778 -- by this recent AI.
780 if not Is_Overloaded (Nam) then
781 if Ekind (Etype (Nam)) /= Ekind (T) then
783 ("expect anonymous access type in object renaming", N);
790 Typ : Entity_Id := Empty;
791 Seen : Boolean := False;
794 Get_First_Interp (Nam, I, It);
795 while Present (It.Typ) loop
797 -- Renaming is ambiguous if more than one candidate
798 -- interpretation is type-conformant with the context.
800 if Ekind (It.Typ) = Ekind (T) then
801 if Ekind (T) = E_Anonymous_Access_Subprogram_Type
804 (Designated_Type (T), Designated_Type (It.Typ))
810 ("ambiguous expression in renaming", Nam);
813 elsif Ekind (T) = E_Anonymous_Access_Type
815 Covers (Designated_Type (T), Designated_Type (It.Typ))
821 ("ambiguous expression in renaming", Nam);
825 if Covers (T, It.Typ) then
827 Set_Etype (Nam, Typ);
828 Set_Is_Overloaded (Nam, False);
832 Get_Next_Interp (I, It);
839 -- Ada 2005 (AI-231): "In the case where the type is defined by an
840 -- access_definition, the renamed entity shall be of an access-to-
841 -- constant type if and only if the access_definition defines an
842 -- access-to-constant type" ARM 8.5.1(4)
844 if Constant_Present (Access_Definition (N))
845 and then not Is_Access_Constant (Etype (Nam))
847 Error_Msg_N ("(Ada 2005): the renamed object is not "
848 & "access-to-constant (RM 8.5.1(6))", N);
850 elsif not Constant_Present (Access_Definition (N))
851 and then Is_Access_Constant (Etype (Nam))
853 Error_Msg_N ("(Ada 2005): the renamed object is not "
854 & "access-to-variable (RM 8.5.1(6))", N);
857 if Is_Access_Subprogram_Type (Etype (Nam)) then
858 Check_Subtype_Conformant
859 (Designated_Type (T), Designated_Type (Etype (Nam)));
861 elsif not Subtypes_Statically_Match
862 (Designated_Type (T), Designated_Type (Etype (Nam)))
865 ("subtype of renamed object does not statically match", N);
869 -- Special processing for renaming function return object
871 if Nkind (Nam) = N_Function_Call
872 and then Comes_From_Source (Nam)
876 -- Usage is illegal in Ada 83
880 ("(Ada 83) cannot rename function return object", Nam);
882 -- In Ada 95, warn for odd case of renaming parameterless function
883 -- call if this is not a limited type (where this is useful)
886 if Warn_On_Object_Renames_Function
887 and then No (Parameter_Associations (Nam))
888 and then not Is_Limited_Type (Etype (Nam))
891 ("?renaming function result object is suspicious",
894 ("\?function & will be called only once",
895 Nam, Entity (Name (Nam)));
897 ("\?suggest using an initialized constant object instead",
903 -- An object renaming requires an exact match of the type. Class-wide
904 -- matching is not allowed.
906 if Is_Class_Wide_Type (T)
907 and then Base_Type (Etype (Nam)) /= Base_Type (T)
914 -- (Ada 2005: AI-326): Handle wrong use of incomplete type
916 if Nkind (Nam) = N_Explicit_Dereference
917 and then Ekind (Etype (T2)) = E_Incomplete_Type
919 Error_Msg_NE ("invalid use of incomplete type&", Id, T2);
921 elsif Ekind (Etype (T)) = E_Incomplete_Type then
922 Error_Msg_NE ("invalid use of incomplete type&", Id, T);
928 if Ada_Version >= Ada_05
929 and then Nkind (Nam) = N_Attribute_Reference
930 and then Attribute_Name (Nam) = Name_Priority
934 elsif Ada_Version >= Ada_05
935 and then Nkind (Nam) in N_Has_Entity
942 if Nkind (Nam) = N_Attribute_Reference then
943 Nam_Ent := Entity (Prefix (Nam));
945 Nam_Ent := Entity (Nam);
948 Nam_Decl := Parent (Nam_Ent);
950 if Has_Null_Exclusion (N)
951 and then not Has_Null_Exclusion (Nam_Decl)
953 -- Ada 2005 (AI-423): If the object name denotes a generic
954 -- formal object of a generic unit G, and the object renaming
955 -- declaration occurs within the body of G or within the body
956 -- of a generic unit declared within the declarative region
957 -- of G, then the declaration of the formal object of G must
958 -- have a null exclusion or a null-excluding subtype.
960 if Is_Formal_Object (Nam_Ent)
961 and then In_Generic_Scope (Id)
963 if not Can_Never_Be_Null (Etype (Nam_Ent)) then
965 ("renamed formal does not exclude `NULL` "
966 & "(RM 8.5.1(4.6/2))", N);
968 elsif In_Package_Body (Scope (Id)) then
970 ("formal object does not have a null exclusion"
971 & "(RM 8.5.1(4.6/2))", N);
974 -- Ada 2005 (AI-423): Otherwise, the subtype of the object name
975 -- shall exclude null.
977 elsif not Can_Never_Be_Null (Etype (Nam_Ent)) then
979 ("renamed object does not exclude `NULL` "
980 & "(RM 8.5.1(4.6/2))", N);
982 -- An instance is illegal if it contains a renaming that
983 -- excludes null, and the actual does not. The renaming
984 -- declaration has already indicated that the declaration
985 -- of the renamed actual in the instance will raise
988 elsif Nkind (Parent (Nam_Ent)) = N_Object_Declaration
991 (Corresponding_Generic_Association (Parent (Nam_Ent)))
992 and then Nkind (Expression (Parent (Nam_Ent)))
993 = N_Raise_Constraint_Error
996 ("renamed actual does not exclude `NULL` "
997 & "(RM 8.5.1(4.6/2))", N);
999 -- Finally, if there is a null exclusion, the subtype mark
1000 -- must not be null-excluding.
1002 elsif No (Access_Definition (N))
1003 and then Can_Never_Be_Null (T)
1006 ("`NOT NULL` not allowed (& already excludes null)",
1011 elsif Can_Never_Be_Null (T)
1012 and then not Can_Never_Be_Null (Etype (Nam_Ent))
1015 ("renamed object does not exclude `NULL` "
1016 & "(RM 8.5.1(4.6/2))", N);
1018 elsif Has_Null_Exclusion (N)
1019 and then No (Access_Definition (N))
1020 and then Can_Never_Be_Null (T)
1023 ("`NOT NULL` not allowed (& already excludes null)", N, T);
1028 Set_Ekind (Id, E_Variable);
1029 Init_Size_Align (Id);
1031 if T = Any_Type or else Etype (Nam) = Any_Type then
1034 -- Verify that the renamed entity is an object or a function call. It
1035 -- may have been rewritten in several ways.
1037 elsif Is_Object_Reference (Nam) then
1038 if Comes_From_Source (N)
1039 and then Is_Dependent_Component_Of_Mutable_Object (Nam)
1042 ("illegal renaming of discriminant-dependent component", Nam);
1047 -- A static function call may have been folded into a literal
1049 elsif Nkind (Original_Node (Nam)) = N_Function_Call
1051 -- When expansion is disabled, attribute reference is not
1052 -- rewritten as function call. Otherwise it may be rewritten
1053 -- as a conversion, so check original node.
1055 or else (Nkind (Original_Node (Nam)) = N_Attribute_Reference
1056 and then Is_Function_Attribute_Name
1057 (Attribute_Name (Original_Node (Nam))))
1059 -- Weird but legal, equivalent to renaming a function call.
1060 -- Illegal if the literal is the result of constant-folding an
1061 -- attribute reference that is not a function.
1063 or else (Is_Entity_Name (Nam)
1064 and then Ekind (Entity (Nam)) = E_Enumeration_Literal
1066 Nkind (Original_Node (Nam)) /= N_Attribute_Reference)
1068 or else (Nkind (Nam) = N_Type_Conversion
1069 and then Is_Tagged_Type (Entity (Subtype_Mark (Nam))))
1073 elsif Nkind (Nam) = N_Type_Conversion then
1075 ("renaming of conversion only allowed for tagged types", Nam);
1077 -- Ada 2005 (AI-327)
1079 elsif Ada_Version >= Ada_05
1080 and then Nkind (Nam) = N_Attribute_Reference
1081 and then Attribute_Name (Nam) = Name_Priority
1085 -- Allow internally generated x'Reference expression
1087 elsif Nkind (Nam) = N_Reference then
1091 Error_Msg_N ("expect object name in renaming", Nam);
1096 if not Is_Variable (Nam) then
1097 Set_Ekind (Id, E_Constant);
1098 Set_Never_Set_In_Source (Id, True);
1099 Set_Is_True_Constant (Id, True);
1102 Set_Renamed_Object (Id, Nam);
1103 end Analyze_Object_Renaming;
1105 ------------------------------
1106 -- Analyze_Package_Renaming --
1107 ------------------------------
1109 procedure Analyze_Package_Renaming (N : Node_Id) is
1110 New_P : constant Entity_Id := Defining_Entity (N);
1115 if Name (N) = Error then
1119 -- Apply Text_IO kludge here, since we may be renaming one of the
1120 -- children of Text_IO.
1122 Text_IO_Kludge (Name (N));
1124 if Current_Scope /= Standard_Standard then
1125 Set_Is_Pure (New_P, Is_Pure (Current_Scope));
1131 if Is_Entity_Name (Name (N)) then
1132 Old_P := Entity (Name (N));
1137 if Etype (Old_P) = Any_Type then
1139 ("expect package name in renaming", Name (N));
1141 elsif Ekind (Old_P) /= E_Package
1142 and then not (Ekind (Old_P) = E_Generic_Package
1143 and then In_Open_Scopes (Old_P))
1145 if Ekind (Old_P) = E_Generic_Package then
1147 ("generic package cannot be renamed as a package", Name (N));
1149 Error_Msg_Sloc := Sloc (Old_P);
1151 ("expect package name in renaming, found& declared#",
1155 -- Set basic attributes to minimize cascaded errors
1157 Set_Ekind (New_P, E_Package);
1158 Set_Etype (New_P, Standard_Void_Type);
1160 -- Here for OK package renaming
1163 -- Entities in the old package are accessible through the renaming
1164 -- entity. The simplest implementation is to have both packages share
1167 Set_Ekind (New_P, E_Package);
1168 Set_Etype (New_P, Standard_Void_Type);
1170 if Present (Renamed_Object (Old_P)) then
1171 Set_Renamed_Object (New_P, Renamed_Object (Old_P));
1173 Set_Renamed_Object (New_P, Old_P);
1176 Set_Has_Completion (New_P);
1178 Set_First_Entity (New_P, First_Entity (Old_P));
1179 Set_Last_Entity (New_P, Last_Entity (Old_P));
1180 Set_First_Private_Entity (New_P, First_Private_Entity (Old_P));
1181 Check_Library_Unit_Renaming (N, Old_P);
1182 Generate_Reference (Old_P, Name (N));
1184 -- If the renaming is in the visible part of a package, then we set
1185 -- Renamed_In_Spec for the renamed package, to prevent giving
1186 -- warnings about no entities referenced. Such a warning would be
1187 -- overenthusiastic, since clients can see entities in the renamed
1188 -- package via the visible package renaming.
1191 Ent : constant Entity_Id := Cunit_Entity (Current_Sem_Unit);
1193 if Ekind (Ent) = E_Package
1194 and then not In_Private_Part (Ent)
1195 and then In_Extended_Main_Source_Unit (N)
1196 and then Ekind (Old_P) = E_Package
1198 Set_Renamed_In_Spec (Old_P);
1202 -- If this is the renaming declaration of a package instantiation
1203 -- within itself, it is the declaration that ends the list of actuals
1204 -- for the instantiation. At this point, the subtypes that rename
1205 -- the actuals are flagged as generic, to avoid spurious ambiguities
1206 -- if the actuals for two distinct formals happen to coincide. If
1207 -- the actual is a private type, the subtype has a private completion
1208 -- that is flagged in the same fashion.
1210 -- Resolution is identical to what is was in the original generic.
1211 -- On exit from the generic instance, these are turned into regular
1212 -- subtypes again, so they are compatible with types in their class.
1214 if not Is_Generic_Instance (Old_P) then
1217 Spec := Specification (Unit_Declaration_Node (Old_P));
1220 if Nkind (Spec) = N_Package_Specification
1221 and then Present (Generic_Parent (Spec))
1222 and then Old_P = Current_Scope
1223 and then Chars (New_P) = Chars (Generic_Parent (Spec))
1229 E := First_Entity (Old_P);
1234 and then Nkind (Parent (E)) = N_Subtype_Declaration
1236 Set_Is_Generic_Actual_Type (E);
1238 if Is_Private_Type (E)
1239 and then Present (Full_View (E))
1241 Set_Is_Generic_Actual_Type (Full_View (E));
1250 end Analyze_Package_Renaming;
1252 -------------------------------
1253 -- Analyze_Renamed_Character --
1254 -------------------------------
1256 procedure Analyze_Renamed_Character
1261 C : constant Node_Id := Name (N);
1264 if Ekind (New_S) = E_Function then
1265 Resolve (C, Etype (New_S));
1268 Check_Frozen_Renaming (N, New_S);
1272 Error_Msg_N ("character literal can only be renamed as function", N);
1274 end Analyze_Renamed_Character;
1276 ---------------------------------
1277 -- Analyze_Renamed_Dereference --
1278 ---------------------------------
1280 procedure Analyze_Renamed_Dereference
1285 Nam : constant Node_Id := Name (N);
1286 P : constant Node_Id := Prefix (Nam);
1292 if not Is_Overloaded (P) then
1293 if Ekind (Etype (Nam)) /= E_Subprogram_Type
1294 or else not Type_Conformant (Etype (Nam), New_S) then
1295 Error_Msg_N ("designated type does not match specification", P);
1304 Get_First_Interp (Nam, Ind, It);
1306 while Present (It.Nam) loop
1308 if Ekind (It.Nam) = E_Subprogram_Type
1309 and then Type_Conformant (It.Nam, New_S) then
1311 if Typ /= Any_Id then
1312 Error_Msg_N ("ambiguous renaming", P);
1319 Get_Next_Interp (Ind, It);
1322 if Typ = Any_Type then
1323 Error_Msg_N ("designated type does not match specification", P);
1328 Check_Frozen_Renaming (N, New_S);
1332 end Analyze_Renamed_Dereference;
1334 ---------------------------
1335 -- Analyze_Renamed_Entry --
1336 ---------------------------
1338 procedure Analyze_Renamed_Entry
1343 Nam : constant Node_Id := Name (N);
1344 Sel : constant Node_Id := Selector_Name (Nam);
1348 if Entity (Sel) = Any_Id then
1350 -- Selector is undefined on prefix. Error emitted already
1352 Set_Has_Completion (New_S);
1356 -- Otherwise find renamed entity and build body of New_S as a call to it
1358 Old_S := Find_Renamed_Entity (N, Selector_Name (Nam), New_S);
1360 if Old_S = Any_Id then
1361 Error_Msg_N (" no subprogram or entry matches specification", N);
1364 Check_Subtype_Conformant (New_S, Old_S, N);
1365 Generate_Reference (New_S, Defining_Entity (N), 'b');
1366 Style.Check_Identifier (Defining_Entity (N), New_S);
1369 -- Only mode conformance required for a renaming_as_declaration
1371 Check_Mode_Conformant (New_S, Old_S, N);
1374 Inherit_Renamed_Profile (New_S, Old_S);
1376 -- The prefix can be an arbitrary expression that yields a task
1377 -- type, so it must be resolved.
1379 Resolve (Prefix (Nam), Scope (Old_S));
1382 Set_Convention (New_S, Convention (Old_S));
1383 Set_Has_Completion (New_S, Inside_A_Generic);
1386 Check_Frozen_Renaming (N, New_S);
1388 end Analyze_Renamed_Entry;
1390 -----------------------------------
1391 -- Analyze_Renamed_Family_Member --
1392 -----------------------------------
1394 procedure Analyze_Renamed_Family_Member
1399 Nam : constant Node_Id := Name (N);
1400 P : constant Node_Id := Prefix (Nam);
1404 if (Is_Entity_Name (P) and then Ekind (Entity (P)) = E_Entry_Family)
1405 or else (Nkind (P) = N_Selected_Component
1407 Ekind (Entity (Selector_Name (P))) = E_Entry_Family)
1409 if Is_Entity_Name (P) then
1410 Old_S := Entity (P);
1412 Old_S := Entity (Selector_Name (P));
1415 if not Entity_Matches_Spec (Old_S, New_S) then
1416 Error_Msg_N ("entry family does not match specification", N);
1419 Check_Subtype_Conformant (New_S, Old_S, N);
1420 Generate_Reference (New_S, Defining_Entity (N), 'b');
1421 Style.Check_Identifier (Defining_Entity (N), New_S);
1425 Error_Msg_N ("no entry family matches specification", N);
1428 Set_Has_Completion (New_S, Inside_A_Generic);
1431 Check_Frozen_Renaming (N, New_S);
1433 end Analyze_Renamed_Family_Member;
1435 -----------------------------------------
1436 -- Analyze_Renamed_Primitive_Operation --
1437 -----------------------------------------
1439 procedure Analyze_Renamed_Primitive_Operation
1448 Ctyp : Conformance_Type) return Boolean;
1449 -- Verify that the signatures of the renamed entity and the new entity
1450 -- match. The first formal of the renamed entity is skipped because it
1451 -- is the target object in any subsequent call.
1455 Ctyp : Conformance_Type) return Boolean
1461 if Ekind (Subp) /= Ekind (New_S) then
1465 Old_F := Next_Formal (First_Formal (Subp));
1466 New_F := First_Formal (New_S);
1467 while Present (Old_F) and then Present (New_F) loop
1468 if not Conforming_Types (Etype (Old_F), Etype (New_F), Ctyp) then
1472 if Ctyp >= Mode_Conformant
1473 and then Ekind (Old_F) /= Ekind (New_F)
1478 Next_Formal (New_F);
1479 Next_Formal (Old_F);
1486 if not Is_Overloaded (Selector_Name (Name (N))) then
1487 Old_S := Entity (Selector_Name (Name (N)));
1489 if not Conforms (Old_S, Type_Conformant) then
1494 -- Find the operation that matches the given signature
1502 Get_First_Interp (Selector_Name (Name (N)), Ind, It);
1504 while Present (It.Nam) loop
1505 if Conforms (It.Nam, Type_Conformant) then
1509 Get_Next_Interp (Ind, It);
1514 if Old_S = Any_Id then
1515 Error_Msg_N (" no subprogram or entry matches specification", N);
1519 if not Conforms (Old_S, Subtype_Conformant) then
1520 Error_Msg_N ("subtype conformance error in renaming", N);
1523 Generate_Reference (New_S, Defining_Entity (N), 'b');
1524 Style.Check_Identifier (Defining_Entity (N), New_S);
1527 -- Only mode conformance required for a renaming_as_declaration
1529 if not Conforms (Old_S, Mode_Conformant) then
1530 Error_Msg_N ("mode conformance error in renaming", N);
1534 -- Inherit_Renamed_Profile (New_S, Old_S);
1536 -- The prefix can be an arbitrary expression that yields an
1537 -- object, so it must be resolved.
1539 Resolve (Prefix (Name (N)));
1541 end Analyze_Renamed_Primitive_Operation;
1543 ---------------------------------
1544 -- Analyze_Subprogram_Renaming --
1545 ---------------------------------
1547 procedure Analyze_Subprogram_Renaming (N : Node_Id) is
1548 Formal_Spec : constant Node_Id := Corresponding_Formal_Spec (N);
1549 Is_Actual : constant Boolean := Present (Formal_Spec);
1550 Inst_Node : Node_Id := Empty;
1551 Nam : constant Node_Id := Name (N);
1553 Old_S : Entity_Id := Empty;
1554 Rename_Spec : Entity_Id;
1555 Save_AV : constant Ada_Version_Type := Ada_Version;
1556 Save_AV_Exp : constant Ada_Version_Type := Ada_Version_Explicit;
1557 Spec : constant Node_Id := Specification (N);
1559 procedure Check_Null_Exclusion
1562 -- Ada 2005 (AI-423): Given renaming Ren of subprogram Sub, check the
1563 -- following AI rules:
1565 -- If Ren is a renaming of a formal subprogram and one of its
1566 -- parameters has a null exclusion, then the corresponding formal
1567 -- in Sub must also have one. Otherwise the subtype of the Sub's
1568 -- formal parameter must exclude null.
1570 -- If Ren is a renaming of a formal function and its return
1571 -- profile has a null exclusion, then Sub's return profile must
1572 -- have one. Otherwise the subtype of Sub's return profile must
1575 function Original_Subprogram (Subp : Entity_Id) return Entity_Id;
1576 -- Find renamed entity when the declaration is a renaming_as_body and
1577 -- the renamed entity may itself be a renaming_as_body. Used to enforce
1578 -- rule that a renaming_as_body is illegal if the declaration occurs
1579 -- before the subprogram it completes is frozen, and renaming indirectly
1580 -- renames the subprogram itself.(Defect Report 8652/0027).
1582 --------------------------
1583 -- Check_Null_Exclusion --
1584 --------------------------
1586 procedure Check_Null_Exclusion
1590 Ren_Formal : Entity_Id;
1591 Sub_Formal : Entity_Id;
1596 Ren_Formal := First_Formal (Ren);
1597 Sub_Formal := First_Formal (Sub);
1598 while Present (Ren_Formal)
1599 and then Present (Sub_Formal)
1601 if Has_Null_Exclusion (Parent (Ren_Formal))
1603 not (Has_Null_Exclusion (Parent (Sub_Formal))
1604 or else Can_Never_Be_Null (Etype (Sub_Formal)))
1607 ("`NOT NULL` required for parameter &",
1608 Parent (Sub_Formal), Sub_Formal);
1611 Next_Formal (Ren_Formal);
1612 Next_Formal (Sub_Formal);
1615 -- Return profile check
1617 if Nkind (Parent (Ren)) = N_Function_Specification
1618 and then Nkind (Parent (Sub)) = N_Function_Specification
1619 and then Has_Null_Exclusion (Parent (Ren))
1621 not (Has_Null_Exclusion (Parent (Sub))
1622 or else Can_Never_Be_Null (Etype (Sub)))
1625 ("return must specify `NOT NULL`",
1626 Result_Definition (Parent (Sub)));
1628 end Check_Null_Exclusion;
1630 -------------------------
1631 -- Original_Subprogram --
1632 -------------------------
1634 function Original_Subprogram (Subp : Entity_Id) return Entity_Id is
1635 Orig_Decl : Node_Id;
1636 Orig_Subp : Entity_Id;
1639 -- First case: renamed entity is itself a renaming
1641 if Present (Alias (Subp)) then
1642 return Alias (Subp);
1645 Nkind (Unit_Declaration_Node (Subp)) = N_Subprogram_Declaration
1647 (Corresponding_Body (Unit_Declaration_Node (Subp)))
1649 -- Check if renamed entity is a renaming_as_body
1652 Unit_Declaration_Node
1653 (Corresponding_Body (Unit_Declaration_Node (Subp)));
1655 if Nkind (Orig_Decl) = N_Subprogram_Renaming_Declaration then
1656 Orig_Subp := Entity (Name (Orig_Decl));
1658 if Orig_Subp = Rename_Spec then
1660 -- Circularity detected
1665 return (Original_Subprogram (Orig_Subp));
1673 end Original_Subprogram;
1675 -- Start of processing for Analyze_Subprogram_Renaming
1678 -- We must test for the attribute renaming case before the Analyze
1679 -- call because otherwise Sem_Attr will complain that the attribute
1680 -- is missing an argument when it is analyzed.
1682 if Nkind (Nam) = N_Attribute_Reference then
1684 -- In the case of an abstract formal subprogram association, rewrite
1685 -- an actual given by a stream attribute as the name of the
1686 -- corresponding stream primitive of the type.
1688 -- In a generic context the stream operations are not generated, and
1689 -- this must be treated as a normal attribute reference, to be
1690 -- expanded in subsequent instantiations.
1692 if Is_Actual and then Is_Abstract_Subprogram (Formal_Spec)
1693 and then Expander_Active
1696 Stream_Prim : Entity_Id;
1697 Prefix_Type : constant Entity_Id := Entity (Prefix (Nam));
1700 -- The class-wide forms of the stream attributes are not
1701 -- primitive dispatching operations (even though they
1702 -- internally dispatch to a stream attribute).
1704 if Is_Class_Wide_Type (Prefix_Type) then
1706 ("attribute must be a primitive dispatching operation",
1711 -- Retrieve the primitive subprogram associated with the
1712 -- attribute. This can only be a stream attribute, since those
1713 -- are the only ones that are dispatching (and the actual for
1714 -- an abstract formal subprogram must be dispatching
1718 case Attribute_Name (Nam) is
1721 Find_Prim_Op (Prefix_Type, TSS_Stream_Input);
1724 Find_Prim_Op (Prefix_Type, TSS_Stream_Output);
1727 Find_Prim_Op (Prefix_Type, TSS_Stream_Read);
1730 Find_Prim_Op (Prefix_Type, TSS_Stream_Write);
1733 ("attribute must be a primitive"
1734 & " dispatching operation", Nam);
1740 -- If no operation was found, and the type is limited,
1741 -- the user should have defined one.
1743 when Program_Error =>
1744 if Is_Limited_Type (Prefix_Type) then
1746 ("stream operation not defined for type&",
1750 -- Otherwise, compiler should have generated default
1757 -- Rewrite the attribute into the name of its corresponding
1758 -- primitive dispatching subprogram. We can then proceed with
1759 -- the usual processing for subprogram renamings.
1762 Prim_Name : constant Node_Id :=
1763 Make_Identifier (Sloc (Nam),
1764 Chars => Chars (Stream_Prim));
1766 Set_Entity (Prim_Name, Stream_Prim);
1767 Rewrite (Nam, Prim_Name);
1772 -- Normal processing for a renaming of an attribute
1775 Attribute_Renaming (N);
1780 -- Check whether this declaration corresponds to the instantiation
1781 -- of a formal subprogram.
1783 -- If this is an instantiation, the corresponding actual is frozen and
1784 -- error messages can be made more precise. If this is a default
1785 -- subprogram, the entity is already established in the generic, and is
1786 -- not retrieved by visibility. If it is a default with a box, the
1787 -- candidate interpretations, if any, have been collected when building
1788 -- the renaming declaration. If overloaded, the proper interpretation is
1789 -- determined in Find_Renamed_Entity. If the entity is an operator,
1790 -- Find_Renamed_Entity applies additional visibility checks.
1793 Inst_Node := Unit_Declaration_Node (Formal_Spec);
1795 if Is_Entity_Name (Nam)
1796 and then Present (Entity (Nam))
1797 and then not Comes_From_Source (Nam)
1798 and then not Is_Overloaded (Nam)
1800 Old_S := Entity (Nam);
1801 New_S := Analyze_Subprogram_Specification (Spec);
1805 if Ekind (Entity (Nam)) = E_Operator then
1809 if Box_Present (Inst_Node) then
1810 Old_S := Find_Renamed_Entity (N, Name (N), New_S, Is_Actual);
1812 -- If there is an immediately visible homonym of the operator
1813 -- and the declaration has a default, this is worth a warning
1814 -- because the user probably did not intend to get the pre-
1815 -- defined operator, visible in the generic declaration. To
1816 -- find if there is an intended candidate, analyze the renaming
1817 -- again in the current context.
1819 elsif Scope (Old_S) = Standard_Standard
1820 and then Present (Default_Name (Inst_Node))
1823 Decl : constant Node_Id := New_Copy_Tree (N);
1827 Set_Entity (Name (Decl), Empty);
1828 Analyze (Name (Decl));
1830 Find_Renamed_Entity (Decl, Name (Decl), New_S, True);
1833 and then In_Open_Scopes (Scope (Hidden))
1834 and then Is_Immediately_Visible (Hidden)
1835 and then Comes_From_Source (Hidden)
1836 and then Hidden /= Old_S
1838 Error_Msg_Sloc := Sloc (Hidden);
1839 Error_Msg_N ("?default subprogram is resolved " &
1840 "in the generic declaration " &
1841 "(RM 12.6(17))", N);
1842 Error_Msg_NE ("\?and will not use & #", N, Hidden);
1850 New_S := Analyze_Subprogram_Specification (Spec);
1854 -- Renamed entity must be analyzed first, to avoid being hidden by
1855 -- new name (which might be the same in a generic instance).
1859 -- The renaming defines a new overloaded entity, which is analyzed
1860 -- like a subprogram declaration.
1862 New_S := Analyze_Subprogram_Specification (Spec);
1865 if Current_Scope /= Standard_Standard then
1866 Set_Is_Pure (New_S, Is_Pure (Current_Scope));
1869 Rename_Spec := Find_Corresponding_Spec (N);
1871 -- Case of Renaming_As_Body
1873 if Present (Rename_Spec) then
1875 -- Renaming declaration is the completion of the declaration of
1876 -- Rename_Spec. We build an actual body for it at the freezing point.
1878 Set_Corresponding_Spec (N, Rename_Spec);
1880 -- Deal with special case of stream functions of abstract types
1883 if Nkind (Unit_Declaration_Node (Rename_Spec)) =
1884 N_Abstract_Subprogram_Declaration
1886 -- Input stream functions are abstract if the object type is
1887 -- abstract. Similarly, all default stream functions for an
1888 -- interface type are abstract. However, these subprograms may
1889 -- receive explicit declarations in representation clauses, making
1890 -- the attribute subprograms usable as defaults in subsequent
1892 -- In this case we rewrite the declaration to make the subprogram
1893 -- non-abstract. We remove the previous declaration, and insert
1894 -- the new one at the point of the renaming, to prevent premature
1895 -- access to unfrozen types. The new declaration reuses the
1896 -- specification of the previous one, and must not be analyzed.
1899 (Is_Primitive (Entity (Nam))
1901 Is_Abstract_Type (Find_Dispatching_Type (Entity (Nam))));
1903 Old_Decl : constant Node_Id :=
1904 Unit_Declaration_Node (Rename_Spec);
1905 New_Decl : constant Node_Id :=
1906 Make_Subprogram_Declaration (Sloc (N),
1908 Relocate_Node (Specification (Old_Decl)));
1911 Insert_After (N, New_Decl);
1912 Set_Is_Abstract_Subprogram (Rename_Spec, False);
1913 Set_Analyzed (New_Decl);
1917 Set_Corresponding_Body (Unit_Declaration_Node (Rename_Spec), New_S);
1919 if Ada_Version = Ada_83 and then Comes_From_Source (N) then
1920 Error_Msg_N ("(Ada 83) renaming cannot serve as a body", N);
1923 Set_Convention (New_S, Convention (Rename_Spec));
1924 Check_Fully_Conformant (New_S, Rename_Spec);
1925 Set_Public_Status (New_S);
1927 -- The specification does not introduce new formals, but only
1928 -- repeats the formals of the original subprogram declaration.
1929 -- For cross-reference purposes, and for refactoring tools, we
1930 -- treat the formals of the renaming declaration as body formals.
1932 Reference_Body_Formals (Rename_Spec, New_S);
1934 -- Indicate that the entity in the declaration functions like the
1935 -- corresponding body, and is not a new entity. The body will be
1936 -- constructed later at the freeze point, so indicate that the
1937 -- completion has not been seen yet.
1939 Set_Ekind (New_S, E_Subprogram_Body);
1940 New_S := Rename_Spec;
1941 Set_Has_Completion (Rename_Spec, False);
1943 -- Ada 2005: check overriding indicator
1945 if Is_Overriding_Operation (Rename_Spec) then
1946 if Must_Not_Override (Specification (N)) then
1948 ("subprogram& overrides inherited operation",
1951 Style_Check and then not Must_Override (Specification (N))
1953 Style.Missing_Overriding (N, Rename_Spec);
1956 elsif Must_Override (Specification (N)) then
1957 Error_Msg_NE ("subprogram& is not overriding", N, Rename_Spec);
1960 -- Normal subprogram renaming (not renaming as body)
1963 Generate_Definition (New_S);
1964 New_Overloaded_Entity (New_S);
1966 if Is_Entity_Name (Nam)
1967 and then Is_Intrinsic_Subprogram (Entity (Nam))
1971 Check_Delayed_Subprogram (New_S);
1975 -- There is no need for elaboration checks on the new entity, which may
1976 -- be called before the next freezing point where the body will appear.
1977 -- Elaboration checks refer to the real entity, not the one created by
1978 -- the renaming declaration.
1980 Set_Kill_Elaboration_Checks (New_S, True);
1982 if Etype (Nam) = Any_Type then
1983 Set_Has_Completion (New_S);
1986 elsif Nkind (Nam) = N_Selected_Component then
1988 -- A prefix of the form A.B can designate an entry of task A, a
1989 -- protected operation of protected object A, or finally a primitive
1990 -- operation of object A. In the later case, A is an object of some
1991 -- tagged type, or an access type that denotes one such. To further
1992 -- distinguish these cases, note that the scope of a task entry or
1993 -- protected operation is type of the prefix.
1995 -- The prefix could be an overloaded function call that returns both
1996 -- kinds of operations. This overloading pathology is left to the
1997 -- dedicated reader ???
2000 T : constant Entity_Id := Etype (Prefix (Nam));
2009 Is_Tagged_Type (Designated_Type (T))))
2010 and then Scope (Entity (Selector_Name (Nam))) /= T
2012 Analyze_Renamed_Primitive_Operation
2013 (N, New_S, Present (Rename_Spec));
2017 -- Renamed entity is an entry or protected operation. For those
2018 -- cases an explicit body is built (at the point of freezing of
2019 -- this entity) that contains a call to the renamed entity.
2021 -- This is not allowed for renaming as body if the renamed
2022 -- spec is already frozen (see RM 8.5.4(5) for details).
2024 if Present (Rename_Spec)
2025 and then Is_Frozen (Rename_Spec)
2028 ("renaming-as-body cannot rename entry as subprogram", N);
2030 ("\since & is already frozen (RM 8.5.4(5))",
2033 Analyze_Renamed_Entry (N, New_S, Present (Rename_Spec));
2040 elsif Nkind (Nam) = N_Explicit_Dereference then
2042 -- Renamed entity is designated by access_to_subprogram expression.
2043 -- Must build body to encapsulate call, as in the entry case.
2045 Analyze_Renamed_Dereference (N, New_S, Present (Rename_Spec));
2048 elsif Nkind (Nam) = N_Indexed_Component then
2049 Analyze_Renamed_Family_Member (N, New_S, Present (Rename_Spec));
2052 elsif Nkind (Nam) = N_Character_Literal then
2053 Analyze_Renamed_Character (N, New_S, Present (Rename_Spec));
2056 elsif (not Is_Entity_Name (Nam)
2057 and then Nkind (Nam) /= N_Operator_Symbol)
2058 or else not Is_Overloadable (Entity (Nam))
2060 Error_Msg_N ("expect valid subprogram name in renaming", N);
2064 -- Find the renamed entity that matches the given specification. Disable
2065 -- Ada_83 because there is no requirement of full conformance between
2066 -- renamed entity and new entity, even though the same circuit is used.
2068 -- This is a bit of a kludge, which introduces a really irregular use of
2069 -- Ada_Version[_Explicit]. Would be nice to find cleaner way to do this
2072 Ada_Version := Ada_Version_Type'Max (Ada_Version, Ada_95);
2073 Ada_Version_Explicit := Ada_Version;
2076 Old_S := Find_Renamed_Entity (N, Name (N), New_S, Is_Actual);
2078 -- When the renamed subprogram is overloaded and used as an actual
2079 -- of a generic, its entity is set to the first available homonym.
2080 -- We must first disambiguate the name, then set the proper entity.
2083 and then Is_Overloaded (Nam)
2085 Set_Entity (Nam, Old_S);
2089 -- Most common case: subprogram renames subprogram. No body is generated
2090 -- in this case, so we must indicate the declaration is complete as is.
2091 -- and inherit various attributes of the renamed subprogram.
2093 if No (Rename_Spec) then
2094 Set_Has_Completion (New_S);
2095 Set_Is_Imported (New_S, Is_Imported (Entity (Nam)));
2096 Set_Is_Pure (New_S, Is_Pure (Entity (Nam)));
2097 Set_Is_Preelaborated (New_S, Is_Preelaborated (Entity (Nam)));
2099 -- Ada 2005 (AI-423): Check the consistency of null exclusions
2100 -- between a subprogram and its correct renaming.
2102 -- Note: the Any_Id check is a guard that prevents compiler crashes
2103 -- when performing a null exclusion check between a renaming and a
2104 -- renamed subprogram that has been found to be illegal.
2106 if Ada_Version >= Ada_05
2107 and then Entity (Nam) /= Any_Id
2109 Check_Null_Exclusion
2111 Sub => Entity (Nam));
2114 -- Enforce the Ada 2005 rule that the renamed entity cannot require
2115 -- overriding. The flag Requires_Overriding is set very selectively
2116 -- and misses some other illegal cases. The additional conditions
2117 -- checked below are sufficient but not necessary ???
2119 -- The rule does not apply to the renaming generated for an actual
2120 -- subprogram in an instance.
2125 -- Guard against previous errors, and omit renamings of predefined
2128 elsif Ekind (Old_S) /= E_Function
2129 and then Ekind (Old_S) /= E_Procedure
2133 elsif Requires_Overriding (Old_S)
2135 (Is_Abstract_Subprogram (Old_S)
2136 and then Present (Find_Dispatching_Type (Old_S))
2138 not Is_Abstract_Type (Find_Dispatching_Type (Old_S)))
2141 ("renamed entity cannot be "
2142 & "subprogram that requires overriding (RM 8.5.4 (5.1))", N);
2146 if Old_S /= Any_Id then
2148 and then From_Default (N)
2150 -- This is an implicit reference to the default actual
2152 Generate_Reference (Old_S, Nam, Typ => 'i', Force => True);
2154 Generate_Reference (Old_S, Nam);
2157 -- For a renaming-as-body, require subtype conformance, but if the
2158 -- declaration being completed has not been frozen, then inherit the
2159 -- convention of the renamed subprogram prior to checking conformance
2160 -- (unless the renaming has an explicit convention established; the
2161 -- rule stated in the RM doesn't seem to address this ???).
2163 if Present (Rename_Spec) then
2164 Generate_Reference (Rename_Spec, Defining_Entity (Spec), 'b');
2165 Style.Check_Identifier (Defining_Entity (Spec), Rename_Spec);
2167 if not Is_Frozen (Rename_Spec) then
2168 if not Has_Convention_Pragma (Rename_Spec) then
2169 Set_Convention (New_S, Convention (Old_S));
2172 if Ekind (Old_S) /= E_Operator then
2173 Check_Mode_Conformant (New_S, Old_S, Spec);
2176 if Original_Subprogram (Old_S) = Rename_Spec then
2177 Error_Msg_N ("unfrozen subprogram cannot rename itself ", N);
2180 Check_Subtype_Conformant (New_S, Old_S, Spec);
2183 Check_Frozen_Renaming (N, Rename_Spec);
2185 -- Check explicitly that renamed entity is not intrinsic, because
2186 -- in a generic the renamed body is not built. In this case,
2187 -- the renaming_as_body is a completion.
2189 if Inside_A_Generic then
2190 if Is_Frozen (Rename_Spec)
2191 and then Is_Intrinsic_Subprogram (Old_S)
2194 ("subprogram in renaming_as_body cannot be intrinsic",
2198 Set_Has_Completion (Rename_Spec);
2201 elsif Ekind (Old_S) /= E_Operator then
2202 Check_Mode_Conformant (New_S, Old_S);
2205 and then Error_Posted (New_S)
2207 Error_Msg_NE ("invalid actual subprogram: & #!", N, Old_S);
2211 if No (Rename_Spec) then
2213 -- The parameter profile of the new entity is that of the renamed
2214 -- entity: the subtypes given in the specification are irrelevant.
2216 Inherit_Renamed_Profile (New_S, Old_S);
2218 -- A call to the subprogram is transformed into a call to the
2219 -- renamed entity. This is transitive if the renamed entity is
2220 -- itself a renaming.
2222 if Present (Alias (Old_S)) then
2223 Set_Alias (New_S, Alias (Old_S));
2225 Set_Alias (New_S, Old_S);
2228 -- Note that we do not set Is_Intrinsic_Subprogram if we have a
2229 -- renaming as body, since the entity in this case is not an
2230 -- intrinsic (it calls an intrinsic, but we have a real body for
2231 -- this call, and it is in this body that the required intrinsic
2232 -- processing will take place).
2234 -- Also, if this is a renaming of inequality, the renamed operator
2235 -- is intrinsic, but what matters is the corresponding equality
2236 -- operator, which may be user-defined.
2238 Set_Is_Intrinsic_Subprogram
2240 Is_Intrinsic_Subprogram (Old_S)
2242 (Chars (Old_S) /= Name_Op_Ne
2243 or else Ekind (Old_S) = E_Operator
2245 Is_Intrinsic_Subprogram
2246 (Corresponding_Equality (Old_S))));
2248 if Ekind (Alias (New_S)) = E_Operator then
2249 Set_Has_Delayed_Freeze (New_S, False);
2252 -- If the renaming corresponds to an association for an abstract
2253 -- formal subprogram, then various attributes must be set to
2254 -- indicate that the renaming is an abstract dispatching operation
2255 -- with a controlling type.
2257 if Is_Actual and then Is_Abstract_Subprogram (Formal_Spec) then
2259 -- Mark the renaming as abstract here, so Find_Dispatching_Type
2260 -- see it as corresponding to a generic association for a
2261 -- formal abstract subprogram
2263 Set_Is_Abstract_Subprogram (New_S);
2266 New_S_Ctrl_Type : constant Entity_Id :=
2267 Find_Dispatching_Type (New_S);
2268 Old_S_Ctrl_Type : constant Entity_Id :=
2269 Find_Dispatching_Type (Old_S);
2272 if Old_S_Ctrl_Type /= New_S_Ctrl_Type then
2274 ("actual must be dispatching subprogram for type&",
2275 Nam, New_S_Ctrl_Type);
2278 Set_Is_Dispatching_Operation (New_S);
2279 Check_Controlling_Formals (New_S_Ctrl_Type, New_S);
2281 -- If the actual in the formal subprogram is itself a
2282 -- formal abstract subprogram association, there's no
2283 -- dispatch table component or position to inherit.
2285 if Present (DTC_Entity (Old_S)) then
2286 Set_DTC_Entity (New_S, DTC_Entity (Old_S));
2287 Set_DT_Position (New_S, DT_Position (Old_S));
2295 and then (Old_S = New_S
2296 or else (Nkind (Nam) /= N_Expanded_Name
2297 and then Chars (Old_S) = Chars (New_S)))
2299 Error_Msg_N ("subprogram cannot rename itself", N);
2302 Set_Convention (New_S, Convention (Old_S));
2304 if Is_Abstract_Subprogram (Old_S) then
2305 if Present (Rename_Spec) then
2307 ("a renaming-as-body cannot rename an abstract subprogram",
2309 Set_Has_Completion (Rename_Spec);
2311 Set_Is_Abstract_Subprogram (New_S);
2315 Check_Library_Unit_Renaming (N, Old_S);
2317 -- Pathological case: procedure renames entry in the scope of its
2318 -- task. Entry is given by simple name, but body must be built for
2319 -- procedure. Of course if called it will deadlock.
2321 if Ekind (Old_S) = E_Entry then
2322 Set_Has_Completion (New_S, False);
2323 Set_Alias (New_S, Empty);
2327 Freeze_Before (N, Old_S);
2328 Set_Has_Delayed_Freeze (New_S, False);
2329 Freeze_Before (N, New_S);
2331 -- An abstract subprogram is only allowed as an actual in the case
2332 -- where the formal subprogram is also abstract.
2334 if (Ekind (Old_S) = E_Procedure or else Ekind (Old_S) = E_Function)
2335 and then Is_Abstract_Subprogram (Old_S)
2336 and then not Is_Abstract_Subprogram (Formal_Spec)
2339 ("abstract subprogram not allowed as generic actual", Nam);
2344 -- A common error is to assume that implicit operators for types are
2345 -- defined in Standard, or in the scope of a subtype. In those cases
2346 -- where the renamed entity is given with an expanded name, it is
2347 -- worth mentioning that operators for the type are not declared in
2348 -- the scope given by the prefix.
2350 if Nkind (Nam) = N_Expanded_Name
2351 and then Nkind (Selector_Name (Nam)) = N_Operator_Symbol
2352 and then Scope (Entity (Nam)) = Standard_Standard
2355 T : constant Entity_Id :=
2356 Base_Type (Etype (First_Formal (New_S)));
2358 Error_Msg_Node_2 := Prefix (Nam);
2360 ("operator for type& is not declared in&", Prefix (Nam), T);
2365 ("no visible subprogram matches the specification for&",
2369 if Present (Candidate_Renaming) then
2375 F1 := First_Formal (Candidate_Renaming);
2376 F2 := First_Formal (New_S);
2378 while Present (F1) and then Present (F2) loop
2383 if Present (F1) and then Present (Default_Value (F1)) then
2384 if Present (Next_Formal (F1)) then
2386 ("\missing specification for &" &
2387 " and other formals with defaults", Spec, F1);
2390 ("\missing specification for &", Spec, F1);
2397 -- Ada 2005 AI 404: if the new subprogram is dispatching, verify that
2398 -- controlling access parameters are known non-null for the renamed
2399 -- subprogram. Test also applies to a subprogram instantiation that
2400 -- is dispatching. Test is skipped if some previous error was detected
2401 -- that set Old_S to Any_Id.
2403 if Ada_Version >= Ada_05
2404 and then Old_S /= Any_Id
2405 and then not Is_Dispatching_Operation (Old_S)
2406 and then Is_Dispatching_Operation (New_S)
2413 Old_F := First_Formal (Old_S);
2414 New_F := First_Formal (New_S);
2415 while Present (Old_F) loop
2416 if Ekind (Etype (Old_F)) = E_Anonymous_Access_Type
2417 and then Is_Controlling_Formal (New_F)
2418 and then not Can_Never_Be_Null (Old_F)
2420 Error_Msg_N ("access parameter is controlling,", New_F);
2422 ("\corresponding parameter of& "
2423 & "must be explicitly null excluding", New_F, Old_S);
2426 Next_Formal (Old_F);
2427 Next_Formal (New_F);
2432 -- A useful warning, suggested by Ada Bug Finder (Ada-Europe 2005)
2434 if Comes_From_Source (N)
2435 and then Present (Old_S)
2436 and then Nkind (Old_S) = N_Defining_Operator_Symbol
2437 and then Nkind (New_S) = N_Defining_Operator_Symbol
2438 and then Chars (Old_S) /= Chars (New_S)
2441 ("?& is being renamed as a different operator",
2445 -- Another warning or some utility: if the new subprogram as the same
2446 -- name as the old one, the old one is not hidden by an outer homograph,
2447 -- the new one is not a public symbol, and the old one is otherwise
2448 -- directly visible, the renaming is superfluous.
2450 if Chars (Old_S) = Chars (New_S)
2451 and then Comes_From_Source (N)
2452 and then Scope (Old_S) /= Standard_Standard
2453 and then Warn_On_Redundant_Constructs
2455 (Is_Immediately_Visible (Old_S)
2456 or else Is_Potentially_Use_Visible (Old_S))
2457 and then Is_Overloadable (Current_Scope)
2458 and then Chars (Current_Scope) /= Chars (Old_S)
2461 ("?redundant renaming, entity is directly visible", Name (N));
2464 Ada_Version := Save_AV;
2465 Ada_Version_Explicit := Save_AV_Exp;
2466 end Analyze_Subprogram_Renaming;
2468 -------------------------
2469 -- Analyze_Use_Package --
2470 -------------------------
2472 -- Resolve the package names in the use clause, and make all the visible
2473 -- entities defined in the package potentially use-visible. If the package
2474 -- is already in use from a previous use clause, its visible entities are
2475 -- already use-visible. In that case, mark the occurrence as a redundant
2476 -- use. If the package is an open scope, i.e. if the use clause occurs
2477 -- within the package itself, ignore it.
2479 procedure Analyze_Use_Package (N : Node_Id) is
2480 Pack_Name : Node_Id;
2483 -- Start of processing for Analyze_Use_Package
2486 Set_Hidden_By_Use_Clause (N, No_Elist);
2488 -- Use clause is not allowed in a spec of a predefined package
2489 -- declaration except that packages whose file name starts a-n are OK
2490 -- (these are children of Ada.Numerics, and such packages are never
2491 -- loaded by Rtsfind).
2493 if Is_Predefined_File_Name (Unit_File_Name (Current_Sem_Unit))
2494 and then Name_Buffer (1 .. 3) /= "a-n"
2496 Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Declaration
2498 Error_Msg_N ("use clause not allowed in predefined spec", N);
2501 -- Chain clause to list of use clauses in current scope
2503 if Nkind (Parent (N)) /= N_Compilation_Unit then
2504 Chain_Use_Clause (N);
2507 -- Loop through package names to identify referenced packages
2509 Pack_Name := First (Names (N));
2510 while Present (Pack_Name) loop
2511 Analyze (Pack_Name);
2513 if Nkind (Parent (N)) = N_Compilation_Unit
2514 and then Nkind (Pack_Name) = N_Expanded_Name
2520 Pref := Prefix (Pack_Name);
2521 while Nkind (Pref) = N_Expanded_Name loop
2522 Pref := Prefix (Pref);
2525 if Entity (Pref) = Standard_Standard then
2527 ("predefined package Standard cannot appear"
2528 & " in a context clause", Pref);
2536 -- Loop through package names to mark all entities as potentially
2539 Pack_Name := First (Names (N));
2540 while Present (Pack_Name) loop
2541 if Is_Entity_Name (Pack_Name) then
2542 Pack := Entity (Pack_Name);
2544 if Ekind (Pack) /= E_Package
2545 and then Etype (Pack) /= Any_Type
2547 if Ekind (Pack) = E_Generic_Package then
2549 ("a generic package is not allowed in a use clause",
2552 Error_Msg_N ("& is not a usable package", Pack_Name);
2556 if Nkind (Parent (N)) = N_Compilation_Unit then
2557 Check_In_Previous_With_Clause (N, Pack_Name);
2560 if Applicable_Use (Pack_Name) then
2561 Use_One_Package (Pack, N);
2565 -- Report error because name denotes something other than a package
2568 Error_Msg_N ("& is not a package", Pack_Name);
2573 end Analyze_Use_Package;
2575 ----------------------
2576 -- Analyze_Use_Type --
2577 ----------------------
2579 procedure Analyze_Use_Type (N : Node_Id) is
2584 Set_Hidden_By_Use_Clause (N, No_Elist);
2586 -- Chain clause to list of use clauses in current scope
2588 if Nkind (Parent (N)) /= N_Compilation_Unit then
2589 Chain_Use_Clause (N);
2592 Id := First (Subtype_Marks (N));
2593 while Present (Id) loop
2597 if E /= Any_Type then
2600 if Nkind (Parent (N)) = N_Compilation_Unit then
2601 if Nkind (Id) = N_Identifier then
2602 Error_Msg_N ("type is not directly visible", Id);
2604 elsif Is_Child_Unit (Scope (E))
2605 and then Scope (E) /= System_Aux_Id
2607 Check_In_Previous_With_Clause (N, Prefix (Id));
2612 -- If the use_type_clause appears in a compilation unit context,
2613 -- check whether it comes from a unit that may appear in a
2614 -- limited_with_clause, for a better error message.
2616 if Nkind (Parent (N)) = N_Compilation_Unit
2617 and then Nkind (Id) /= N_Identifier
2623 function Mentioned (Nam : Node_Id) return Boolean;
2624 -- Check whether the prefix of expanded name for the type
2625 -- appears in the prefix of some limited_with_clause.
2631 function Mentioned (Nam : Node_Id) return Boolean is
2633 return Nkind (Name (Item)) = N_Selected_Component
2635 Chars (Prefix (Name (Item))) = Chars (Nam);
2639 Pref := Prefix (Id);
2640 Item := First (Context_Items (Parent (N)));
2642 while Present (Item) and then Item /= N loop
2643 if Nkind (Item) = N_With_Clause
2644 and then Limited_Present (Item)
2645 and then Mentioned (Pref)
2648 (Get_Msg_Id, "premature usage of incomplete type");
2659 end Analyze_Use_Type;
2661 --------------------
2662 -- Applicable_Use --
2663 --------------------
2665 function Applicable_Use (Pack_Name : Node_Id) return Boolean is
2666 Pack : constant Entity_Id := Entity (Pack_Name);
2669 if In_Open_Scopes (Pack) then
2670 if Warn_On_Redundant_Constructs
2671 and then Pack = Current_Scope
2674 ("& is already use-visible within itself?", Pack_Name, Pack);
2679 elsif In_Use (Pack) then
2680 Note_Redundant_Use (Pack_Name);
2683 elsif Present (Renamed_Object (Pack))
2684 and then In_Use (Renamed_Object (Pack))
2686 Note_Redundant_Use (Pack_Name);
2694 ------------------------
2695 -- Attribute_Renaming --
2696 ------------------------
2698 procedure Attribute_Renaming (N : Node_Id) is
2699 Loc : constant Source_Ptr := Sloc (N);
2700 Nam : constant Node_Id := Name (N);
2701 Spec : constant Node_Id := Specification (N);
2702 New_S : constant Entity_Id := Defining_Unit_Name (Spec);
2703 Aname : constant Name_Id := Attribute_Name (Nam);
2705 Form_Num : Nat := 0;
2706 Expr_List : List_Id := No_List;
2708 Attr_Node : Node_Id;
2709 Body_Node : Node_Id;
2710 Param_Spec : Node_Id;
2713 Generate_Definition (New_S);
2715 -- This procedure is called in the context of subprogram renaming, and
2716 -- thus the attribute must be one that is a subprogram. All of those
2717 -- have at least one formal parameter, with the singular exception of
2718 -- AST_Entry (which is a real oddity, it is odd that this can be renamed
2721 if not Is_Non_Empty_List (Parameter_Specifications (Spec)) then
2722 if Aname /= Name_AST_Entry then
2724 ("subprogram renaming an attribute must have formals", N);
2729 Param_Spec := First (Parameter_Specifications (Spec));
2730 while Present (Param_Spec) loop
2731 Form_Num := Form_Num + 1;
2733 if Nkind (Parameter_Type (Param_Spec)) /= N_Access_Definition then
2734 Find_Type (Parameter_Type (Param_Spec));
2736 -- The profile of the new entity denotes the base type (s) of
2737 -- the types given in the specification. For access parameters
2738 -- there are no subtypes involved.
2740 Rewrite (Parameter_Type (Param_Spec),
2742 (Base_Type (Entity (Parameter_Type (Param_Spec))), Loc));
2745 if No (Expr_List) then
2746 Expr_List := New_List;
2749 Append_To (Expr_List,
2750 Make_Identifier (Loc,
2751 Chars => Chars (Defining_Identifier (Param_Spec))));
2753 -- The expressions in the attribute reference are not freeze
2754 -- points. Neither is the attribute as a whole, see below.
2756 Set_Must_Not_Freeze (Last (Expr_List));
2761 -- Immediate error if too many formals. Other mismatches in number or
2762 -- types of parameters are detected when we analyze the body of the
2763 -- subprogram that we construct.
2765 if Form_Num > 2 then
2766 Error_Msg_N ("too many formals for attribute", N);
2768 -- Error if the attribute reference has expressions that look like
2769 -- formal parameters.
2771 elsif Present (Expressions (Nam)) then
2772 Error_Msg_N ("illegal expressions in attribute reference", Nam);
2775 Aname = Name_Compose or else
2776 Aname = Name_Exponent or else
2777 Aname = Name_Leading_Part or else
2778 Aname = Name_Pos or else
2779 Aname = Name_Round or else
2780 Aname = Name_Scaling or else
2783 if Nkind (N) = N_Subprogram_Renaming_Declaration
2784 and then Present (Corresponding_Formal_Spec (N))
2787 ("generic actual cannot be attribute involving universal type",
2791 ("attribute involving a universal type cannot be renamed",
2796 -- AST_Entry is an odd case. It doesn't really make much sense to allow
2797 -- it to be renamed, but that's the DEC rule, so we have to do it right.
2798 -- The point is that the AST_Entry call should be made now, and what the
2799 -- function will return is the returned value.
2801 -- Note that there is no Expr_List in this case anyway
2803 if Aname = Name_AST_Entry then
2809 Ent := Make_Defining_Identifier (Loc, New_Internal_Name ('R'));
2812 Make_Object_Declaration (Loc,
2813 Defining_Identifier => Ent,
2814 Object_Definition =>
2815 New_Occurrence_Of (RTE (RE_AST_Handler), Loc),
2817 Constant_Present => True);
2819 Set_Assignment_OK (Decl, True);
2820 Insert_Action (N, Decl);
2821 Attr_Node := Make_Identifier (Loc, Chars (Ent));
2824 -- For all other attributes, we rewrite the attribute node to have
2825 -- a list of expressions corresponding to the subprogram formals.
2826 -- A renaming declaration is not a freeze point, and the analysis of
2827 -- the attribute reference should not freeze the type of the prefix.
2831 Make_Attribute_Reference (Loc,
2832 Prefix => Prefix (Nam),
2833 Attribute_Name => Aname,
2834 Expressions => Expr_List);
2836 Set_Must_Not_Freeze (Attr_Node);
2837 Set_Must_Not_Freeze (Prefix (Nam));
2840 -- Case of renaming a function
2842 if Nkind (Spec) = N_Function_Specification then
2843 if Is_Procedure_Attribute_Name (Aname) then
2844 Error_Msg_N ("attribute can only be renamed as procedure", Nam);
2848 Find_Type (Result_Definition (Spec));
2849 Rewrite (Result_Definition (Spec),
2851 Base_Type (Entity (Result_Definition (Spec))), Loc));
2854 Make_Subprogram_Body (Loc,
2855 Specification => Spec,
2856 Declarations => New_List,
2857 Handled_Statement_Sequence =>
2858 Make_Handled_Sequence_Of_Statements (Loc,
2859 Statements => New_List (
2860 Make_Simple_Return_Statement (Loc,
2861 Expression => Attr_Node))));
2863 -- Case of renaming a procedure
2866 if not Is_Procedure_Attribute_Name (Aname) then
2867 Error_Msg_N ("attribute can only be renamed as function", Nam);
2872 Make_Subprogram_Body (Loc,
2873 Specification => Spec,
2874 Declarations => New_List,
2875 Handled_Statement_Sequence =>
2876 Make_Handled_Sequence_Of_Statements (Loc,
2877 Statements => New_List (Attr_Node)));
2880 -- In case of tagged types we add the body of the generated function to
2881 -- the freezing actions of the type (because in the general case such
2882 -- type is still not frozen). We exclude from this processing generic
2883 -- formal subprograms found in instantiations and AST_Entry renamings.
2885 if not Present (Corresponding_Formal_Spec (N))
2886 and then Etype (Nam) /= RTE (RE_AST_Handler)
2889 P : constant Entity_Id := Prefix (Nam);
2894 if Is_Tagged_Type (Etype (P)) then
2895 Ensure_Freeze_Node (Etype (P));
2896 Append_Freeze_Action (Etype (P), Body_Node);
2898 Rewrite (N, Body_Node);
2900 Set_Etype (New_S, Base_Type (Etype (New_S)));
2904 -- Generic formal subprograms or AST_Handler renaming
2907 Rewrite (N, Body_Node);
2909 Set_Etype (New_S, Base_Type (Etype (New_S)));
2912 if Is_Compilation_Unit (New_S) then
2914 ("a library unit can only rename another library unit", N);
2917 -- We suppress elaboration warnings for the resulting entity, since
2918 -- clearly they are not needed, and more particularly, in the case
2919 -- of a generic formal subprogram, the resulting entity can appear
2920 -- after the instantiation itself, and thus look like a bogus case
2921 -- of access before elaboration.
2923 Set_Suppress_Elaboration_Warnings (New_S);
2925 end Attribute_Renaming;
2927 ----------------------
2928 -- Chain_Use_Clause --
2929 ----------------------
2931 procedure Chain_Use_Clause (N : Node_Id) is
2933 Level : Int := Scope_Stack.Last;
2936 if not Is_Compilation_Unit (Current_Scope)
2937 or else not Is_Child_Unit (Current_Scope)
2939 null; -- Common case
2941 elsif Defining_Entity (Parent (N)) = Current_Scope then
2942 null; -- Common case for compilation unit
2945 -- If declaration appears in some other scope, it must be in some
2946 -- parent unit when compiling a child.
2948 Pack := Defining_Entity (Parent (N));
2949 if not In_Open_Scopes (Pack) then
2950 null; -- default as well
2953 -- Find entry for parent unit in scope stack
2955 while Scope_Stack.Table (Level).Entity /= Pack loop
2961 Set_Next_Use_Clause (N,
2962 Scope_Stack.Table (Level).First_Use_Clause);
2963 Scope_Stack.Table (Level).First_Use_Clause := N;
2964 end Chain_Use_Clause;
2966 ---------------------------
2967 -- Check_Frozen_Renaming --
2968 ---------------------------
2970 procedure Check_Frozen_Renaming (N : Node_Id; Subp : Entity_Id) is
2976 and then not Has_Completion (Subp)
2980 (Parent (Declaration_Node (Subp)), Defining_Entity (N));
2982 if Is_Entity_Name (Name (N)) then
2983 Old_S := Entity (Name (N));
2985 if not Is_Frozen (Old_S)
2986 and then Operating_Mode /= Check_Semantics
2988 Append_Freeze_Action (Old_S, B_Node);
2990 Insert_After (N, B_Node);
2994 if Is_Intrinsic_Subprogram (Old_S)
2995 and then not In_Instance
2998 ("subprogram used in renaming_as_body cannot be intrinsic",
3003 Insert_After (N, B_Node);
3007 end Check_Frozen_Renaming;
3009 -----------------------------------
3010 -- Check_In_Previous_With_Clause --
3011 -----------------------------------
3013 procedure Check_In_Previous_With_Clause
3017 Pack : constant Entity_Id := Entity (Original_Node (Nam));
3022 Item := First (Context_Items (Parent (N)));
3024 while Present (Item)
3027 if Nkind (Item) = N_With_Clause
3029 -- Protect the frontend against previous critical errors
3031 and then Nkind (Name (Item)) /= N_Selected_Component
3032 and then Entity (Name (Item)) = Pack
3036 -- Find root library unit in with_clause
3038 while Nkind (Par) = N_Expanded_Name loop
3039 Par := Prefix (Par);
3042 if Is_Child_Unit (Entity (Original_Node (Par))) then
3044 ("& is not directly visible", Par, Entity (Par));
3053 -- On exit, package is not mentioned in a previous with_clause.
3054 -- Check if its prefix is.
3056 if Nkind (Nam) = N_Expanded_Name then
3057 Check_In_Previous_With_Clause (N, Prefix (Nam));
3059 elsif Pack /= Any_Id then
3060 Error_Msg_NE ("& is not visible", Nam, Pack);
3062 end Check_In_Previous_With_Clause;
3064 ---------------------------------
3065 -- Check_Library_Unit_Renaming --
3066 ---------------------------------
3068 procedure Check_Library_Unit_Renaming (N : Node_Id; Old_E : Entity_Id) is
3072 if Nkind (Parent (N)) /= N_Compilation_Unit then
3075 -- Check for library unit. Note that we used to check for the scope
3076 -- being Standard here, but that was wrong for Standard itself.
3078 elsif not Is_Compilation_Unit (Old_E)
3079 and then not Is_Child_Unit (Old_E)
3081 Error_Msg_N ("renamed unit must be a library unit", Name (N));
3083 -- Entities defined in Standard (operators and boolean literals) cannot
3084 -- be renamed as library units.
3086 elsif Scope (Old_E) = Standard_Standard
3087 and then Sloc (Old_E) = Standard_Location
3089 Error_Msg_N ("renamed unit must be a library unit", Name (N));
3091 elsif Present (Parent_Spec (N))
3092 and then Nkind (Unit (Parent_Spec (N))) = N_Generic_Package_Declaration
3093 and then not Is_Child_Unit (Old_E)
3096 ("renamed unit must be a child unit of generic parent", Name (N));
3098 elsif Nkind (N) in N_Generic_Renaming_Declaration
3099 and then Nkind (Name (N)) = N_Expanded_Name
3100 and then Is_Generic_Instance (Entity (Prefix (Name (N))))
3101 and then Is_Generic_Unit (Old_E)
3104 ("renamed generic unit must be a library unit", Name (N));
3106 elsif Is_Package_Or_Generic_Package (Old_E) then
3108 -- Inherit categorization flags
3110 New_E := Defining_Entity (N);
3111 Set_Is_Pure (New_E, Is_Pure (Old_E));
3112 Set_Is_Preelaborated (New_E, Is_Preelaborated (Old_E));
3113 Set_Is_Remote_Call_Interface (New_E,
3114 Is_Remote_Call_Interface (Old_E));
3115 Set_Is_Remote_Types (New_E, Is_Remote_Types (Old_E));
3116 Set_Is_Shared_Passive (New_E, Is_Shared_Passive (Old_E));
3118 end Check_Library_Unit_Renaming;
3124 procedure End_Scope is
3130 Id := First_Entity (Current_Scope);
3131 while Present (Id) loop
3132 -- An entity in the current scope is not necessarily the first one
3133 -- on its homonym chain. Find its predecessor if any,
3134 -- If it is an internal entity, it will not be in the visibility
3135 -- chain altogether, and there is nothing to unchain.
3137 if Id /= Current_Entity (Id) then
3138 Prev := Current_Entity (Id);
3139 while Present (Prev)
3140 and then Present (Homonym (Prev))
3141 and then Homonym (Prev) /= Id
3143 Prev := Homonym (Prev);
3146 -- Skip to end of loop if Id is not in the visibility chain
3148 if No (Prev) or else Homonym (Prev) /= Id then
3156 Set_Is_Immediately_Visible (Id, False);
3158 Outer := Homonym (Id);
3159 while Present (Outer) and then Scope (Outer) = Current_Scope loop
3160 Outer := Homonym (Outer);
3163 -- Reset homonym link of other entities, but do not modify link
3164 -- between entities in current scope, so that the back-end can have
3165 -- a proper count of local overloadings.
3168 Set_Name_Entity_Id (Chars (Id), Outer);
3170 elsif Scope (Prev) /= Scope (Id) then
3171 Set_Homonym (Prev, Outer);
3178 -- If the scope generated freeze actions, place them before the
3179 -- current declaration and analyze them. Type declarations and
3180 -- the bodies of initialization procedures can generate such nodes.
3181 -- We follow the parent chain until we reach a list node, which is
3182 -- the enclosing list of declarations. If the list appears within
3183 -- a protected definition, move freeze nodes outside the protected
3187 (Scope_Stack.Table (Scope_Stack.Last).Pending_Freeze_Actions)
3191 L : constant List_Id := Scope_Stack.Table
3192 (Scope_Stack.Last).Pending_Freeze_Actions;
3195 if Is_Itype (Current_Scope) then
3196 Decl := Associated_Node_For_Itype (Current_Scope);
3198 Decl := Parent (Current_Scope);
3203 while not (Is_List_Member (Decl))
3204 or else Nkind_In (Parent (Decl), N_Protected_Definition,
3207 Decl := Parent (Decl);
3210 Insert_List_Before_And_Analyze (Decl, L);
3219 ---------------------
3220 -- End_Use_Clauses --
3221 ---------------------
3223 procedure End_Use_Clauses (Clause : Node_Id) is
3227 -- Remove Use_Type clauses first, because they affect the
3228 -- visibility of operators in subsequent used packages.
3231 while Present (U) loop
3232 if Nkind (U) = N_Use_Type_Clause then
3236 Next_Use_Clause (U);
3240 while Present (U) loop
3241 if Nkind (U) = N_Use_Package_Clause then
3242 End_Use_Package (U);
3245 Next_Use_Clause (U);
3247 end End_Use_Clauses;
3249 ---------------------
3250 -- End_Use_Package --
3251 ---------------------
3253 procedure End_Use_Package (N : Node_Id) is
3254 Pack_Name : Node_Id;
3259 function Is_Primitive_Operator
3261 F : Entity_Id) return Boolean;
3262 -- Check whether Op is a primitive operator of a use-visible type
3264 ---------------------------
3265 -- Is_Primitive_Operator --
3266 ---------------------------
3268 function Is_Primitive_Operator
3270 F : Entity_Id) return Boolean
3272 T : constant Entity_Id := Etype (F);
3275 and then Scope (T) = Scope (Op);
3276 end Is_Primitive_Operator;
3278 -- Start of processing for End_Use_Package
3281 Pack_Name := First (Names (N));
3282 while Present (Pack_Name) loop
3284 -- Test that Pack_Name actually denotes a package before processing
3286 if Is_Entity_Name (Pack_Name)
3287 and then Ekind (Entity (Pack_Name)) = E_Package
3289 Pack := Entity (Pack_Name);
3291 if In_Open_Scopes (Pack) then
3294 elsif not Redundant_Use (Pack_Name) then
3295 Set_In_Use (Pack, False);
3296 Set_Current_Use_Clause (Pack, Empty);
3298 Id := First_Entity (Pack);
3299 while Present (Id) loop
3301 -- Preserve use-visibility of operators that are primitive
3302 -- operators of a type that is use-visible through an active
3305 if Nkind (Id) = N_Defining_Operator_Symbol
3307 (Is_Primitive_Operator (Id, First_Formal (Id))
3309 (Present (Next_Formal (First_Formal (Id)))
3311 Is_Primitive_Operator
3312 (Id, Next_Formal (First_Formal (Id)))))
3317 Set_Is_Potentially_Use_Visible (Id, False);
3320 if Is_Private_Type (Id)
3321 and then Present (Full_View (Id))
3323 Set_Is_Potentially_Use_Visible (Full_View (Id), False);
3329 if Present (Renamed_Object (Pack)) then
3330 Set_In_Use (Renamed_Object (Pack), False);
3331 Set_Current_Use_Clause (Renamed_Object (Pack), Empty);
3334 if Chars (Pack) = Name_System
3335 and then Scope (Pack) = Standard_Standard
3336 and then Present_System_Aux
3338 Id := First_Entity (System_Aux_Id);
3339 while Present (Id) loop
3340 Set_Is_Potentially_Use_Visible (Id, False);
3342 if Is_Private_Type (Id)
3343 and then Present (Full_View (Id))
3345 Set_Is_Potentially_Use_Visible (Full_View (Id), False);
3351 Set_In_Use (System_Aux_Id, False);
3355 Set_Redundant_Use (Pack_Name, False);
3362 if Present (Hidden_By_Use_Clause (N)) then
3363 Elmt := First_Elmt (Hidden_By_Use_Clause (N));
3364 while Present (Elmt) loop
3366 E : constant Entity_Id := Node (Elmt);
3369 -- Reset either Use_Visibility or Direct_Visibility, depending
3370 -- on how the entity was hidden by the use clause.
3372 if In_Use (Scope (E))
3373 and then Used_As_Generic_Actual (Scope (E))
3375 Set_Is_Potentially_Use_Visible (Node (Elmt));
3377 Set_Is_Immediately_Visible (Node (Elmt));
3384 Set_Hidden_By_Use_Clause (N, No_Elist);
3386 end End_Use_Package;
3392 procedure End_Use_Type (N : Node_Id) is
3399 Id := First (Subtype_Marks (N));
3400 while Present (Id) loop
3402 -- A call to rtsfind may occur while analyzing a use_type clause,
3403 -- in which case the type marks are not resolved yet, and there is
3404 -- nothing to remove.
3406 if not Is_Entity_Name (Id)
3407 or else No (Entity (Id))
3415 or else From_With_Type (T)
3419 -- Note that the use_Type clause may mention a subtype of the type
3420 -- whose primitive operations have been made visible. Here as
3421 -- elsewhere, it is the base type that matters for visibility.
3423 elsif In_Open_Scopes (Scope (Base_Type (T))) then
3426 elsif not Redundant_Use (Id) then
3427 Set_In_Use (T, False);
3428 Set_In_Use (Base_Type (T), False);
3429 Set_Current_Use_Clause (T, Empty);
3430 Set_Current_Use_Clause (Base_Type (T), Empty);
3431 Op_List := Collect_Primitive_Operations (T);
3433 Elmt := First_Elmt (Op_List);
3434 while Present (Elmt) loop
3435 if Nkind (Node (Elmt)) = N_Defining_Operator_Symbol then
3436 Set_Is_Potentially_Use_Visible (Node (Elmt), False);
3448 ----------------------
3449 -- Find_Direct_Name --
3450 ----------------------
3452 procedure Find_Direct_Name (N : Node_Id) is
3457 Inst : Entity_Id := Empty;
3458 -- Enclosing instance, if any
3460 Homonyms : Entity_Id;
3461 -- Saves start of homonym chain
3463 Nvis_Entity : Boolean;
3464 -- Set True to indicate that there is at least one entity on the homonym
3465 -- chain which, while not visible, is visible enough from the user point
3466 -- of view to warrant an error message of "not visible" rather than
3469 Nvis_Is_Private_Subprg : Boolean := False;
3470 -- Ada 2005 (AI-262): Set True to indicate that a form of Beaujolais
3471 -- effect concerning library subprograms has been detected. Used to
3472 -- generate the precise error message.
3474 function From_Actual_Package (E : Entity_Id) return Boolean;
3475 -- Returns true if the entity is declared in a package that is
3476 -- an actual for a formal package of the current instance. Such an
3477 -- entity requires special handling because it may be use-visible
3478 -- but hides directly visible entities defined outside the instance.
3480 function Is_Actual_Parameter return Boolean;
3481 -- This function checks if the node N is an identifier that is an actual
3482 -- parameter of a procedure call. If so it returns True, otherwise it
3483 -- return False. The reason for this check is that at this stage we do
3484 -- not know what procedure is being called if the procedure might be
3485 -- overloaded, so it is premature to go setting referenced flags or
3486 -- making calls to Generate_Reference. We will wait till Resolve_Actuals
3487 -- for that processing
3489 function Known_But_Invisible (E : Entity_Id) return Boolean;
3490 -- This function determines whether the entity E (which is not
3491 -- visible) can reasonably be considered to be known to the writer
3492 -- of the reference. This is a heuristic test, used only for the
3493 -- purposes of figuring out whether we prefer to complain that an
3494 -- entity is undefined or invisible (and identify the declaration
3495 -- of the invisible entity in the latter case). The point here is
3496 -- that we don't want to complain that something is invisible and
3497 -- then point to something entirely mysterious to the writer.
3499 procedure Nvis_Messages;
3500 -- Called if there are no visible entries for N, but there is at least
3501 -- one non-directly visible, or hidden declaration. This procedure
3502 -- outputs an appropriate set of error messages.
3504 procedure Undefined (Nvis : Boolean);
3505 -- This function is called if the current node has no corresponding
3506 -- visible entity or entities. The value set in Msg indicates whether
3507 -- an error message was generated (multiple error messages for the
3508 -- same variable are generally suppressed, see body for details).
3509 -- Msg is True if an error message was generated, False if not. This
3510 -- value is used by the caller to determine whether or not to output
3511 -- additional messages where appropriate. The parameter is set False
3512 -- to get the message "X is undefined", and True to get the message
3513 -- "X is not visible".
3515 -------------------------
3516 -- From_Actual_Package --
3517 -------------------------
3519 function From_Actual_Package (E : Entity_Id) return Boolean is
3520 Scop : constant Entity_Id := Scope (E);
3524 if not In_Instance then
3527 Inst := Current_Scope;
3528 while Present (Inst)
3529 and then Ekind (Inst) /= E_Package
3530 and then not Is_Generic_Instance (Inst)
3532 Inst := Scope (Inst);
3539 Act := First_Entity (Inst);
3540 while Present (Act) loop
3541 if Ekind (Act) = E_Package then
3543 -- Check for end of actuals list
3545 if Renamed_Object (Act) = Inst then
3548 elsif Present (Associated_Formal_Package (Act))
3549 and then Renamed_Object (Act) = Scop
3551 -- Entity comes from (instance of) formal package
3566 end From_Actual_Package;
3568 -------------------------
3569 -- Is_Actual_Parameter --
3570 -------------------------
3572 function Is_Actual_Parameter return Boolean is
3575 Nkind (N) = N_Identifier
3577 (Nkind (Parent (N)) = N_Procedure_Call_Statement
3579 (Nkind (Parent (N)) = N_Parameter_Association
3580 and then N = Explicit_Actual_Parameter (Parent (N))
3581 and then Nkind (Parent (Parent (N))) =
3582 N_Procedure_Call_Statement));
3583 end Is_Actual_Parameter;
3585 -------------------------
3586 -- Known_But_Invisible --
3587 -------------------------
3589 function Known_But_Invisible (E : Entity_Id) return Boolean is
3590 Fname : File_Name_Type;
3593 -- Entities in Standard are always considered to be known
3595 if Sloc (E) <= Standard_Location then
3598 -- An entity that does not come from source is always considered
3599 -- to be unknown, since it is an artifact of code expansion.
3601 elsif not Comes_From_Source (E) then
3604 -- In gnat internal mode, we consider all entities known
3606 elsif GNAT_Mode then
3610 -- Here we have an entity that is not from package Standard, and
3611 -- which comes from Source. See if it comes from an internal file.
3613 Fname := Unit_File_Name (Get_Source_Unit (E));
3615 -- Case of from internal file
3617 if Is_Internal_File_Name (Fname) then
3619 -- Private part entities in internal files are never considered
3620 -- to be known to the writer of normal application code.
3622 if Is_Hidden (E) then
3626 -- Entities from System packages other than System and
3627 -- System.Storage_Elements are not considered to be known.
3628 -- System.Auxxxx files are also considered known to the user.
3630 -- Should refine this at some point to generally distinguish
3631 -- between known and unknown internal files ???
3633 Get_Name_String (Fname);
3638 Name_Buffer (1 .. 2) /= "s-"
3640 Name_Buffer (3 .. 8) = "stoele"
3642 Name_Buffer (3 .. 5) = "aux";
3644 -- If not an internal file, then entity is definitely known,
3645 -- even if it is in a private part (the message generated will
3646 -- note that it is in a private part)
3651 end Known_But_Invisible;
3657 procedure Nvis_Messages is
3658 Comp_Unit : Node_Id;
3660 Hidden : Boolean := False;
3664 -- Ada 2005 (AI-262): Generate a precise error concerning the
3665 -- Beaujolais effect that was previously detected
3667 if Nvis_Is_Private_Subprg then
3669 pragma Assert (Nkind (E2) = N_Defining_Identifier
3670 and then Ekind (E2) = E_Function
3671 and then Scope (E2) = Standard_Standard
3672 and then Has_Private_With (E2));
3674 -- Find the sloc corresponding to the private with'ed unit
3676 Comp_Unit := Cunit (Current_Sem_Unit);
3677 Error_Msg_Sloc := No_Location;
3679 Item := First (Context_Items (Comp_Unit));
3680 while Present (Item) loop
3681 if Nkind (Item) = N_With_Clause
3682 and then Private_Present (Item)
3683 and then Entity (Name (Item)) = E2
3685 Error_Msg_Sloc := Sloc (Item);
3692 pragma Assert (Error_Msg_Sloc /= No_Location);
3694 Error_Msg_N ("(Ada 2005): hidden by private with clause #", N);
3698 Undefined (Nvis => True);
3702 -- First loop does hidden declarations
3705 while Present (Ent) loop
3706 if Is_Potentially_Use_Visible (Ent) then
3708 Error_Msg_N ("multiple use clauses cause hiding!", N);
3712 Error_Msg_Sloc := Sloc (Ent);
3713 Error_Msg_N ("hidden declaration#!", N);
3716 Ent := Homonym (Ent);
3719 -- If we found hidden declarations, then that's enough, don't
3720 -- bother looking for non-visible declarations as well.
3726 -- Second loop does non-directly visible declarations
3729 while Present (Ent) loop
3730 if not Is_Potentially_Use_Visible (Ent) then
3732 -- Do not bother the user with unknown entities
3734 if not Known_But_Invisible (Ent) then
3738 Error_Msg_Sloc := Sloc (Ent);
3740 -- Output message noting that there is a non-visible
3741 -- declaration, distinguishing the private part case.
3743 if Is_Hidden (Ent) then
3744 Error_Msg_N ("non-visible (private) declaration#!", N);
3746 Error_Msg_N ("non-visible declaration#!", N);
3748 if Is_Compilation_Unit (Ent)
3750 Nkind (Parent (Parent (N))) = N_Use_Package_Clause
3752 Error_Msg_Qual_Level := 99;
3753 Error_Msg_NE ("\\missing `WITH &;`", N, Ent);
3754 Error_Msg_Qual_Level := 0;
3758 -- Set entity and its containing package as referenced. We
3759 -- can't be sure of this, but this seems a better choice
3760 -- to avoid unused entity messages.
3762 if Comes_From_Source (Ent) then
3763 Set_Referenced (Ent);
3764 Set_Referenced (Cunit_Entity (Get_Source_Unit (Ent)));
3769 Ent := Homonym (Ent);
3778 procedure Undefined (Nvis : Boolean) is
3779 Emsg : Error_Msg_Id;
3782 -- We should never find an undefined internal name. If we do, then
3783 -- see if we have previous errors. If so, ignore on the grounds that
3784 -- it is probably a cascaded message (e.g. a block label from a badly
3785 -- formed block). If no previous errors, then we have a real internal
3786 -- error of some kind so raise an exception.
3788 if Is_Internal_Name (Chars (N)) then
3789 if Total_Errors_Detected /= 0 then
3792 raise Program_Error;
3796 -- A very specialized error check, if the undefined variable is
3797 -- a case tag, and the case type is an enumeration type, check
3798 -- for a possible misspelling, and if so, modify the identifier
3800 -- Named aggregate should also be handled similarly ???
3802 if Nkind (N) = N_Identifier
3803 and then Nkind (Parent (N)) = N_Case_Statement_Alternative
3806 Case_Stm : constant Node_Id := Parent (Parent (N));
3807 Case_Typ : constant Entity_Id := Etype (Expression (Case_Stm));
3812 if Is_Enumeration_Type (Case_Typ)
3813 and then not Is_Standard_Character_Type (Case_Typ)
3815 Lit := First_Literal (Case_Typ);
3816 Get_Name_String (Chars (Lit));
3818 if Chars (Lit) /= Chars (N)
3819 and then Is_Bad_Spelling_Of (Chars (N), Chars (Lit)) then
3820 Error_Msg_Node_2 := Lit;
3822 ("& is undefined, assume misspelling of &", N);
3823 Rewrite (N, New_Occurrence_Of (Lit, Sloc (N)));
3827 Lit := Next_Literal (Lit);
3832 -- Normal processing
3834 Set_Entity (N, Any_Id);
3835 Set_Etype (N, Any_Type);
3837 -- We use the table Urefs to keep track of entities for which we
3838 -- have issued errors for undefined references. Multiple errors
3839 -- for a single name are normally suppressed, however we modify
3840 -- the error message to alert the programmer to this effect.
3842 for J in Urefs.First .. Urefs.Last loop
3843 if Chars (N) = Chars (Urefs.Table (J).Node) then
3844 if Urefs.Table (J).Err /= No_Error_Msg
3845 and then Sloc (N) /= Urefs.Table (J).Loc
3847 Error_Msg_Node_1 := Urefs.Table (J).Node;
3849 if Urefs.Table (J).Nvis then
3850 Change_Error_Text (Urefs.Table (J).Err,
3851 "& is not visible (more references follow)");
3853 Change_Error_Text (Urefs.Table (J).Err,
3854 "& is undefined (more references follow)");
3857 Urefs.Table (J).Err := No_Error_Msg;
3860 -- Although we will set Msg False, and thus suppress the
3861 -- message, we also set Error_Posted True, to avoid any
3862 -- cascaded messages resulting from the undefined reference.
3865 Set_Error_Posted (N, True);
3870 -- If entry not found, this is first undefined occurrence
3873 Error_Msg_N ("& is not visible!", N);
3877 Error_Msg_N ("& is undefined!", N);
3880 -- A very bizarre special check, if the undefined identifier
3881 -- is put or put_line, then add a special error message (since
3882 -- this is a very common error for beginners to make).
3884 if Chars (N) = Name_Put or else Chars (N) = Name_Put_Line then
3886 ("\\possible missing `WITH Ada.Text_'I'O; " &
3887 "USE Ada.Text_'I'O`!", N);
3889 -- Another special check if N is the prefix of a selected
3890 -- component which is a known unit, add message complaining
3891 -- about missing with for this unit.
3893 elsif Nkind (Parent (N)) = N_Selected_Component
3894 and then N = Prefix (Parent (N))
3895 and then Is_Known_Unit (Parent (N))
3897 Error_Msg_Node_2 := Selector_Name (Parent (N));
3898 Error_Msg_N ("\\missing `WITH &.&;`", Prefix (Parent (N)));
3901 -- Now check for possible misspellings
3905 Ematch : Entity_Id := Empty;
3907 Last_Name_Id : constant Name_Id :=
3908 Name_Id (Nat (First_Name_Id) +
3909 Name_Entries_Count - 1);
3912 for Nam in First_Name_Id .. Last_Name_Id loop
3913 E := Get_Name_Entity_Id (Nam);
3916 and then (Is_Immediately_Visible (E)
3918 Is_Potentially_Use_Visible (E))
3920 if Is_Bad_Spelling_Of (Chars (N), Nam) then
3927 if Present (Ematch) then
3928 Error_Msg_NE ("\possible misspelling of&", N, Ematch);
3933 -- Make entry in undefined references table unless the full errors
3934 -- switch is set, in which case by refraining from generating the
3935 -- table entry, we guarantee that we get an error message for every
3936 -- undefined reference.
3938 if not All_Errors_Mode then
3949 -- Start of processing for Find_Direct_Name
3952 -- If the entity pointer is already set, this is an internal node, or
3953 -- a node that is analyzed more than once, after a tree modification.
3954 -- In such a case there is no resolution to perform, just set the type.
3956 if Present (Entity (N)) then
3957 if Is_Type (Entity (N)) then
3958 Set_Etype (N, Entity (N));
3962 Entyp : constant Entity_Id := Etype (Entity (N));
3965 -- One special case here. If the Etype field is already set,
3966 -- and references the packed array type corresponding to the
3967 -- etype of the referenced entity, then leave it alone. This
3968 -- happens for trees generated from Exp_Pakd, where expressions
3969 -- can be deliberately "mis-typed" to the packed array type.
3971 if Is_Array_Type (Entyp)
3972 and then Is_Packed (Entyp)
3973 and then Present (Etype (N))
3974 and then Etype (N) = Packed_Array_Type (Entyp)
3978 -- If not that special case, then just reset the Etype
3981 Set_Etype (N, Etype (Entity (N)));
3989 -- Here if Entity pointer was not set, we need full visibility analysis
3990 -- First we generate debugging output if the debug E flag is set.
3992 if Debug_Flag_E then
3993 Write_Str ("Looking for ");
3994 Write_Name (Chars (N));
3998 Homonyms := Current_Entity (N);
3999 Nvis_Entity := False;
4002 while Present (E) loop
4004 -- If entity is immediately visible or potentially use visible, then
4005 -- process the entity and we are done.
4007 if Is_Immediately_Visible (E) then
4008 goto Immediately_Visible_Entity;
4010 elsif Is_Potentially_Use_Visible (E) then
4011 goto Potentially_Use_Visible_Entity;
4013 -- Note if a known but invisible entity encountered
4015 elsif Known_But_Invisible (E) then
4016 Nvis_Entity := True;
4019 -- Move to next entity in chain and continue search
4024 -- If no entries on homonym chain that were potentially visible,
4025 -- and no entities reasonably considered as non-visible, then
4026 -- we have a plain undefined reference, with no additional
4027 -- explanation required!
4029 if not Nvis_Entity then
4030 Undefined (Nvis => False);
4032 -- Otherwise there is at least one entry on the homonym chain that
4033 -- is reasonably considered as being known and non-visible.
4041 -- Processing for a potentially use visible entry found. We must search
4042 -- the rest of the homonym chain for two reasons. First, if there is a
4043 -- directly visible entry, then none of the potentially use-visible
4044 -- entities are directly visible (RM 8.4(10)). Second, we need to check
4045 -- for the case of multiple potentially use-visible entries hiding one
4046 -- another and as a result being non-directly visible (RM 8.4(11)).
4048 <<Potentially_Use_Visible_Entity>> declare
4049 Only_One_Visible : Boolean := True;
4050 All_Overloadable : Boolean := Is_Overloadable (E);
4054 while Present (E2) loop
4055 if Is_Immediately_Visible (E2) then
4057 -- If the use-visible entity comes from the actual for a
4058 -- formal package, it hides a directly visible entity from
4059 -- outside the instance.
4061 if From_Actual_Package (E)
4062 and then Scope_Depth (E2) < Scope_Depth (Inst)
4067 goto Immediately_Visible_Entity;
4070 elsif Is_Potentially_Use_Visible (E2) then
4071 Only_One_Visible := False;
4072 All_Overloadable := All_Overloadable and Is_Overloadable (E2);
4074 -- Ada 2005 (AI-262): Protect against a form of Beaujolais effect
4075 -- that can occur in private_with clauses. Example:
4078 -- private with B; package A is
4079 -- package C is function B return Integer;
4081 -- V1 : Integer := B;
4082 -- private function B return Integer;
4083 -- V2 : Integer := B;
4086 -- V1 resolves to A.B, but V2 resolves to library unit B
4088 elsif Ekind (E2) = E_Function
4089 and then Scope (E2) = Standard_Standard
4090 and then Has_Private_With (E2)
4092 Only_One_Visible := False;
4093 All_Overloadable := False;
4094 Nvis_Is_Private_Subprg := True;
4101 -- On falling through this loop, we have checked that there are no
4102 -- immediately visible entities. Only_One_Visible is set if exactly
4103 -- one potentially use visible entity exists. All_Overloadable is
4104 -- set if all the potentially use visible entities are overloadable.
4105 -- The condition for legality is that either there is one potentially
4106 -- use visible entity, or if there is more than one, then all of them
4107 -- are overloadable.
4109 if Only_One_Visible or All_Overloadable then
4112 -- If there is more than one potentially use-visible entity and at
4113 -- least one of them non-overloadable, we have an error (RM 8.4(11).
4114 -- Note that E points to the first such entity on the homonym list.
4115 -- Special case: if one of the entities is declared in an actual
4116 -- package, it was visible in the generic, and takes precedence over
4117 -- other entities that are potentially use-visible. Same if it is
4118 -- declared in a local instantiation of the current instance.
4123 -- Find current instance
4125 Inst := Current_Scope;
4126 while Present (Inst)
4127 and then Inst /= Standard_Standard
4129 if Is_Generic_Instance (Inst) then
4133 Inst := Scope (Inst);
4137 while Present (E2) loop
4138 if From_Actual_Package (E2)
4140 (Is_Generic_Instance (Scope (E2))
4141 and then Scope_Depth (Scope (E2)) > Scope_Depth (Inst))
4154 Is_Predefined_File_Name (Unit_File_Name (Current_Sem_Unit))
4156 -- A use-clause in the body of a system file creates conflict
4157 -- with some entity in a user scope, while rtsfind is active.
4158 -- Keep only the entity coming from another predefined unit.
4161 while Present (E2) loop
4162 if Is_Predefined_File_Name
4163 (Unit_File_Name (Get_Source_Unit (Sloc (E2))))
4172 -- Entity must exist because predefined unit is correct
4174 raise Program_Error;
4183 -- Come here with E set to the first immediately visible entity on
4184 -- the homonym chain. This is the one we want unless there is another
4185 -- immediately visible entity further on in the chain for an inner
4186 -- scope (RM 8.3(8)).
4188 <<Immediately_Visible_Entity>> declare
4193 -- Find scope level of initial entity. When compiling through
4194 -- Rtsfind, the previous context is not completely invisible, and
4195 -- an outer entity may appear on the chain, whose scope is below
4196 -- the entry for Standard that delimits the current scope stack.
4197 -- Indicate that the level for this spurious entry is outside of
4198 -- the current scope stack.
4200 Level := Scope_Stack.Last;
4202 Scop := Scope_Stack.Table (Level).Entity;
4203 exit when Scop = Scope (E);
4205 exit when Scop = Standard_Standard;
4208 -- Now search remainder of homonym chain for more inner entry
4209 -- If the entity is Standard itself, it has no scope, and we
4210 -- compare it with the stack entry directly.
4213 while Present (E2) loop
4214 if Is_Immediately_Visible (E2) then
4216 -- If a generic package contains a local declaration that
4217 -- has the same name as the generic, there may be a visibility
4218 -- conflict in an instance, where the local declaration must
4219 -- also hide the name of the corresponding package renaming.
4220 -- We check explicitly for a package declared by a renaming,
4221 -- whose renamed entity is an instance that is on the scope
4222 -- stack, and that contains a homonym in the same scope. Once
4223 -- we have found it, we know that the package renaming is not
4224 -- immediately visible, and that the identifier denotes the
4225 -- other entity (and its homonyms if overloaded).
4227 if Scope (E) = Scope (E2)
4228 and then Ekind (E) = E_Package
4229 and then Present (Renamed_Object (E))
4230 and then Is_Generic_Instance (Renamed_Object (E))
4231 and then In_Open_Scopes (Renamed_Object (E))
4232 and then Comes_From_Source (N)
4234 Set_Is_Immediately_Visible (E, False);
4238 for J in Level + 1 .. Scope_Stack.Last loop
4239 if Scope_Stack.Table (J).Entity = Scope (E2)
4240 or else Scope_Stack.Table (J).Entity = E2
4253 -- At the end of that loop, E is the innermost immediately
4254 -- visible entity, so we are all set.
4257 -- Come here with entity found, and stored in E
4261 -- When distribution features are available (Get_PCS_Name /=
4262 -- Name_No_DSA), a remote access-to-subprogram type is converted
4263 -- into a record type holding whatever information is needed to
4264 -- perform a remote call on an RCI subprogram. In that case we
4265 -- rewrite any occurrence of the RAS type into the equivalent record
4266 -- type here. 'Access attribute references and RAS dereferences are
4267 -- then implemented using specific TSSs. However when distribution is
4268 -- not available (case of Get_PCS_Name = Name_No_DSA), we bypass the
4269 -- generation of these TSSs, and we must keep the RAS type in its
4270 -- original access-to-subprogram form (since all calls through a
4271 -- value of such type will be local anyway in the absence of a PCS).
4273 if Comes_From_Source (N)
4274 and then Is_Remote_Access_To_Subprogram_Type (E)
4275 and then Expander_Active
4276 and then Get_PCS_Name /= Name_No_DSA
4279 New_Occurrence_Of (Equivalent_Type (E), Sloc (N)));
4284 -- Why no Style_Check here???
4289 Set_Etype (N, Get_Full_View (Etype (E)));
4292 if Debug_Flag_E then
4293 Write_Str (" found ");
4294 Write_Entity_Info (E, " ");
4297 -- If the Ekind of the entity is Void, it means that all homonyms
4298 -- are hidden from all visibility (RM 8.3(5,14-20)). However, this
4299 -- test is skipped if the current scope is a record and the name is
4300 -- a pragma argument expression (case of Atomic and Volatile pragmas
4301 -- and possibly other similar pragmas added later, which are allowed
4302 -- to reference components in the current record).
4304 if Ekind (E) = E_Void
4306 (not Is_Record_Type (Current_Scope)
4307 or else Nkind (Parent (N)) /= N_Pragma_Argument_Association)
4309 Premature_Usage (N);
4311 -- If the entity is overloadable, collect all interpretations of the
4312 -- name for subsequent overload resolution. We optimize a bit here to
4313 -- do this only if we have an overloadable entity that is not on its
4314 -- own on the homonym chain.
4316 elsif Is_Overloadable (E)
4317 and then (Present (Homonym (E)) or else Current_Entity (N) /= E)
4319 Collect_Interps (N);
4321 -- If no homonyms were visible, the entity is unambiguous
4323 if not Is_Overloaded (N) then
4324 if not Is_Actual_Parameter then
4325 Generate_Reference (E, N);
4329 -- Case of non-overloadable entity, set the entity providing that
4330 -- we do not have the case of a discriminant reference within a
4331 -- default expression. Such references are replaced with the
4332 -- corresponding discriminal, which is the formal corresponding to
4333 -- to the discriminant in the initialization procedure.
4336 -- Entity is unambiguous, indicate that it is referenced here
4338 -- For a renaming of an object, always generate simple reference,
4339 -- we don't try to keep track of assignments in this case.
4341 if Is_Object (E) and then Present (Renamed_Object (E)) then
4342 Generate_Reference (E, N);
4344 -- If the renamed entity is a private protected component,
4345 -- reference the original component as well. This needs to be
4346 -- done because the private renamings are installed before any
4347 -- analysis has occurred. Reference to a private component will
4348 -- resolve to the renaming and the original component will be
4349 -- left unreferenced, hence the following.
4351 if Is_Prival (E) then
4352 Generate_Reference (Prival_Link (E), N);
4355 -- One odd case is that we do not want to set the Referenced flag
4356 -- if the entity is a label, and the identifier is the label in
4357 -- the source, since this is not a reference from the point of
4358 -- view of the user.
4360 elsif Nkind (Parent (N)) = N_Label then
4362 R : constant Boolean := Referenced (E);
4365 -- Generate reference unless this is an actual parameter
4366 -- (see comment below)
4368 if Is_Actual_Parameter then
4369 Generate_Reference (E, N);
4370 Set_Referenced (E, R);
4374 -- Normal case, not a label: generate reference
4376 -- ??? It is too early to generate a reference here even if
4377 -- the entity is unambiguous, because the tree is not
4378 -- sufficiently typed at this point for Generate_Reference to
4379 -- determine whether this reference modifies the denoted object
4380 -- (because implicit dereferences cannot be identified prior to
4381 -- full type resolution).
4383 -- The Is_Actual_Parameter routine takes care of one of these
4384 -- cases but there are others probably ???
4387 if not Is_Actual_Parameter then
4388 Generate_Reference (E, N);
4391 Check_Nested_Access (E);
4394 -- Set Entity, with style check if need be. For a discriminant
4395 -- reference, replace by the corresponding discriminal, i.e. the
4396 -- parameter of the initialization procedure that corresponds to
4397 -- the discriminant. If this replacement is being performed, there
4398 -- is no style check to perform.
4400 -- This replacement must not be done if we are currently
4401 -- processing a generic spec or body, because the discriminal
4402 -- has not been not generated in this case.
4404 -- The replacement is also skipped if we are in special
4405 -- spec-expression mode. Why is this skipped in this case ???
4407 if not In_Spec_Expression
4408 or else Ekind (E) /= E_Discriminant
4409 or else Inside_A_Generic
4411 Set_Entity_With_Style_Check (N, E);
4413 -- The replacement is not done either for a task discriminant that
4414 -- appears in a default expression of an entry parameter. See
4415 -- Expand_Discriminant in exp_ch2 for details on their handling.
4417 elsif Is_Concurrent_Type (Scope (E)) then
4424 and then not Nkind_In (P, N_Parameter_Specification,
4425 N_Component_Declaration)
4431 and then Nkind (P) = N_Parameter_Specification
4435 Set_Entity (N, Discriminal (E));
4439 -- Otherwise, this is a discriminant in a context in which
4440 -- it is a reference to the corresponding parameter of the
4441 -- init proc for the enclosing type.
4444 Set_Entity (N, Discriminal (E));
4448 end Find_Direct_Name;
4450 ------------------------
4451 -- Find_Expanded_Name --
4452 ------------------------
4454 -- This routine searches the homonym chain of the entity until it finds
4455 -- an entity declared in the scope denoted by the prefix. If the entity
4456 -- is private, it may nevertheless be immediately visible, if we are in
4457 -- the scope of its declaration.
4459 procedure Find_Expanded_Name (N : Node_Id) is
4460 Selector : constant Node_Id := Selector_Name (N);
4461 Candidate : Entity_Id := Empty;
4467 P_Name := Entity (Prefix (N));
4470 -- If the prefix is a renamed package, look for the entity in the
4471 -- original package.
4473 if Ekind (P_Name) = E_Package
4474 and then Present (Renamed_Object (P_Name))
4476 P_Name := Renamed_Object (P_Name);
4478 -- Rewrite node with entity field pointing to renamed object
4480 Rewrite (Prefix (N), New_Copy (Prefix (N)));
4481 Set_Entity (Prefix (N), P_Name);
4483 -- If the prefix is an object of a concurrent type, look for
4484 -- the entity in the associated task or protected type.
4486 elsif Is_Concurrent_Type (Etype (P_Name)) then
4487 P_Name := Etype (P_Name);
4490 Id := Current_Entity (Selector);
4493 Is_New_Candidate : Boolean;
4496 while Present (Id) loop
4497 if Scope (Id) = P_Name then
4499 Is_New_Candidate := True;
4501 -- Ada 2005 (AI-217): Handle shadow entities associated with types
4502 -- declared in limited-withed nested packages. We don't need to
4503 -- handle E_Incomplete_Subtype entities because the entities in
4504 -- the limited view are always E_Incomplete_Type entities (see
4505 -- Build_Limited_Views). Regarding the expression used to evaluate
4506 -- the scope, it is important to note that the limited view also
4507 -- has shadow entities associated nested packages. For this reason
4508 -- the correct scope of the entity is the scope of the real entity
4509 -- The non-limited view may itself be incomplete, in which case
4510 -- get the full view if available.
4512 elsif From_With_Type (Id)
4513 and then Is_Type (Id)
4514 and then Ekind (Id) = E_Incomplete_Type
4515 and then Present (Non_Limited_View (Id))
4516 and then Scope (Non_Limited_View (Id)) = P_Name
4518 Candidate := Get_Full_View (Non_Limited_View (Id));
4519 Is_New_Candidate := True;
4522 Is_New_Candidate := False;
4525 if Is_New_Candidate then
4526 if Is_Child_Unit (Id) then
4527 exit when Is_Visible_Child_Unit (Id)
4528 or else Is_Immediately_Visible (Id);
4531 exit when not Is_Hidden (Id)
4532 or else Is_Immediately_Visible (Id);
4541 and then (Ekind (P_Name) = E_Procedure
4543 Ekind (P_Name) = E_Function)
4544 and then Is_Generic_Instance (P_Name)
4546 -- Expanded name denotes entity in (instance of) generic subprogram.
4547 -- The entity may be in the subprogram instance, or may denote one of
4548 -- the formals, which is declared in the enclosing wrapper package.
4550 P_Name := Scope (P_Name);
4552 Id := Current_Entity (Selector);
4553 while Present (Id) loop
4554 exit when Scope (Id) = P_Name;
4559 if No (Id) or else Chars (Id) /= Chars (Selector) then
4560 Set_Etype (N, Any_Type);
4562 -- If we are looking for an entity defined in System, try to find it
4563 -- in the child package that may have been provided as an extension
4564 -- to System. The Extend_System pragma will have supplied the name of
4565 -- the extension, which may have to be loaded.
4567 if Chars (P_Name) = Name_System
4568 and then Scope (P_Name) = Standard_Standard
4569 and then Present (System_Extend_Unit)
4570 and then Present_System_Aux (N)
4572 Set_Entity (Prefix (N), System_Aux_Id);
4573 Find_Expanded_Name (N);
4576 elsif Nkind (Selector) = N_Operator_Symbol
4577 and then Has_Implicit_Operator (N)
4579 -- There is an implicit instance of the predefined operator in
4580 -- the given scope. The operator entity is defined in Standard.
4581 -- Has_Implicit_Operator makes the node into an Expanded_Name.
4585 elsif Nkind (Selector) = N_Character_Literal
4586 and then Has_Implicit_Character_Literal (N)
4588 -- If there is no literal defined in the scope denoted by the
4589 -- prefix, the literal may belong to (a type derived from)
4590 -- Standard_Character, for which we have no explicit literals.
4595 -- If the prefix is a single concurrent object, use its name in
4596 -- the error message, rather than that of the anonymous type.
4598 if Is_Concurrent_Type (P_Name)
4599 and then Is_Internal_Name (Chars (P_Name))
4601 Error_Msg_Node_2 := Entity (Prefix (N));
4603 Error_Msg_Node_2 := P_Name;
4606 if P_Name = System_Aux_Id then
4607 P_Name := Scope (P_Name);
4608 Set_Entity (Prefix (N), P_Name);
4611 if Present (Candidate) then
4613 -- If we know that the unit is a child unit we can give a more
4614 -- accurate error message.
4616 if Is_Child_Unit (Candidate) then
4618 -- If the candidate is a private child unit and we are in
4619 -- the visible part of a public unit, specialize the error
4620 -- message. There might be a private with_clause for it,
4621 -- but it is not currently active.
4623 if Is_Private_Descendant (Candidate)
4624 and then Ekind (Current_Scope) = E_Package
4625 and then not In_Private_Part (Current_Scope)
4626 and then not Is_Private_Descendant (Current_Scope)
4628 Error_Msg_N ("private child unit& is not visible here",
4631 -- Normal case where we have a missing with for a child unit
4634 Error_Msg_Qual_Level := 99;
4635 Error_Msg_NE ("missing `WITH &;`", Selector, Candidate);
4636 Error_Msg_Qual_Level := 0;
4639 -- Here we don't know that this is a child unit
4642 Error_Msg_NE ("& is not a visible entity of&", N, Selector);
4646 -- Within the instantiation of a child unit, the prefix may
4647 -- denote the parent instance, but the selector has the name
4648 -- of the original child. Find whether we are within the
4649 -- corresponding instance, and get the proper entity, which
4650 -- can only be an enclosing scope.
4653 and then In_Open_Scopes (P_Name)
4654 and then Is_Generic_Instance (P_Name)
4657 S : Entity_Id := Current_Scope;
4661 for J in reverse 0 .. Scope_Stack.Last loop
4662 S := Scope_Stack.Table (J).Entity;
4664 exit when S = Standard_Standard;
4666 if Ekind (S) = E_Function
4667 or else Ekind (S) = E_Package
4668 or else Ekind (S) = E_Procedure
4670 P := Generic_Parent (Specification
4671 (Unit_Declaration_Node (S)));
4674 and then Chars (Scope (P)) = Chars (O_Name)
4675 and then Chars (P) = Chars (Selector)
4686 -- If this is a selection from Ada, System or Interfaces, then
4687 -- we assume a missing with for the corresponding package.
4689 if Is_Known_Unit (N) then
4690 if not Error_Posted (N) then
4691 Error_Msg_Node_2 := Selector;
4692 Error_Msg_N ("missing `WITH &.&;`", Prefix (N));
4695 -- If this is a selection from a dummy package, then suppress
4696 -- the error message, of course the entity is missing if the
4697 -- package is missing!
4699 elsif Sloc (Error_Msg_Node_2) = No_Location then
4702 -- Here we have the case of an undefined component
4705 Error_Msg_NE ("& not declared in&", N, Selector);
4707 -- Check for misspelling of some entity in prefix
4709 Id := First_Entity (P_Name);
4710 while Present (Id) loop
4711 if Is_Bad_Spelling_Of (Chars (Id), Chars (Selector))
4712 and then not Is_Internal_Name (Chars (Id))
4715 ("possible misspelling of&", Selector, Id);
4722 -- Specialize the message if this may be an instantiation
4723 -- of a child unit that was not mentioned in the context.
4725 if Nkind (Parent (N)) = N_Package_Instantiation
4726 and then Is_Generic_Instance (Entity (Prefix (N)))
4727 and then Is_Compilation_Unit
4728 (Generic_Parent (Parent (Entity (Prefix (N)))))
4730 Error_Msg_Node_2 := Selector;
4731 Error_Msg_N ("\missing `WITH &.&;`", Prefix (N));
4741 if Comes_From_Source (N)
4742 and then Is_Remote_Access_To_Subprogram_Type (Id)
4743 and then Present (Equivalent_Type (Id))
4745 -- If we are not actually generating distribution code (i.e. the
4746 -- current PCS is the dummy non-distributed version), then the
4747 -- Equivalent_Type will be missing, and Id should be treated as
4748 -- a regular access-to-subprogram type.
4750 Id := Equivalent_Type (Id);
4751 Set_Chars (Selector, Chars (Id));
4754 -- Ada 2005 (AI-50217): Check usage of entities in limited withed units
4756 if Ekind (P_Name) = E_Package
4757 and then From_With_Type (P_Name)
4759 if From_With_Type (Id)
4760 or else Is_Type (Id)
4761 or else Ekind (Id) = E_Package
4766 ("limited withed package can only be used to access "
4767 & "incomplete types",
4772 if Is_Task_Type (P_Name)
4773 and then ((Ekind (Id) = E_Entry
4774 and then Nkind (Parent (N)) /= N_Attribute_Reference)
4776 (Ekind (Id) = E_Entry_Family
4778 Nkind (Parent (Parent (N))) /= N_Attribute_Reference))
4780 -- It is an entry call after all, either to the current task (which
4781 -- will deadlock) or to an enclosing task.
4783 Analyze_Selected_Component (N);
4787 Change_Selected_Component_To_Expanded_Name (N);
4789 -- Do style check and generate reference, but skip both steps if this
4790 -- entity has homonyms, since we may not have the right homonym set yet.
4791 -- The proper homonym will be set during the resolve phase.
4793 if Has_Homonym (Id) then
4796 Set_Entity_With_Style_Check (N, Id);
4797 Generate_Reference (Id, N);
4800 if Is_Type (Id) then
4803 Set_Etype (N, Get_Full_View (Etype (Id)));
4806 -- If the Ekind of the entity is Void, it means that all homonyms are
4807 -- hidden from all visibility (RM 8.3(5,14-20)).
4809 if Ekind (Id) = E_Void then
4810 Premature_Usage (N);
4812 elsif Is_Overloadable (Id)
4813 and then Present (Homonym (Id))
4816 H : Entity_Id := Homonym (Id);
4819 while Present (H) loop
4820 if Scope (H) = Scope (Id)
4823 or else Is_Immediately_Visible (H))
4825 Collect_Interps (N);
4832 -- If an extension of System is present, collect possible explicit
4833 -- overloadings declared in the extension.
4835 if Chars (P_Name) = Name_System
4836 and then Scope (P_Name) = Standard_Standard
4837 and then Present (System_Extend_Unit)
4838 and then Present_System_Aux (N)
4840 H := Current_Entity (Id);
4842 while Present (H) loop
4843 if Scope (H) = System_Aux_Id then
4844 Add_One_Interp (N, H, Etype (H));
4853 if Nkind (Selector_Name (N)) = N_Operator_Symbol
4854 and then Scope (Id) /= Standard_Standard
4856 -- In addition to user-defined operators in the given scope, there
4857 -- may be an implicit instance of the predefined operator. The
4858 -- operator (defined in Standard) is found in Has_Implicit_Operator,
4859 -- and added to the interpretations. Procedure Add_One_Interp will
4860 -- determine which hides which.
4862 if Has_Implicit_Operator (N) then
4866 end Find_Expanded_Name;
4868 -------------------------
4869 -- Find_Renamed_Entity --
4870 -------------------------
4872 function Find_Renamed_Entity
4876 Is_Actual : Boolean := False) return Entity_Id
4879 I1 : Interp_Index := 0; -- Suppress junk warnings
4885 function Enclosing_Instance return Entity_Id;
4886 -- If the renaming determines the entity for the default of a formal
4887 -- subprogram nested within another instance, choose the innermost
4888 -- candidate. This is because if the formal has a box, and we are within
4889 -- an enclosing instance where some candidate interpretations are local
4890 -- to this enclosing instance, we know that the default was properly
4891 -- resolved when analyzing the generic, so we prefer the local
4892 -- candidates to those that are external. This is not always the case
4893 -- but is a reasonable heuristic on the use of nested generics. The
4894 -- proper solution requires a full renaming model.
4896 function Is_Visible_Operation (Op : Entity_Id) return Boolean;
4897 -- If the renamed entity is an implicit operator, check whether it is
4898 -- visible because its operand type is properly visible. This check
4899 -- applies to explicit renamed entities that appear in the source in a
4900 -- renaming declaration or a formal subprogram instance, but not to
4901 -- default generic actuals with a name.
4903 function Report_Overload return Entity_Id;
4904 -- List possible interpretations, and specialize message in the
4905 -- case of a generic actual.
4907 function Within (Inner, Outer : Entity_Id) return Boolean;
4908 -- Determine whether a candidate subprogram is defined within the
4909 -- enclosing instance. If yes, it has precedence over outer candidates.
4911 ------------------------
4912 -- Enclosing_Instance --
4913 ------------------------
4915 function Enclosing_Instance return Entity_Id is
4919 if not Is_Generic_Instance (Current_Scope)
4920 and then not Is_Actual
4925 S := Scope (Current_Scope);
4926 while S /= Standard_Standard loop
4927 if Is_Generic_Instance (S) then
4935 end Enclosing_Instance;
4937 --------------------------
4938 -- Is_Visible_Operation --
4939 --------------------------
4941 function Is_Visible_Operation (Op : Entity_Id) return Boolean is
4947 if Ekind (Op) /= E_Operator
4948 or else Scope (Op) /= Standard_Standard
4949 or else (In_Instance
4952 or else Present (Enclosing_Instance)))
4957 -- For a fixed point type operator, check the resulting type,
4958 -- because it may be a mixed mode integer * fixed operation.
4960 if Present (Next_Formal (First_Formal (New_S)))
4961 and then Is_Fixed_Point_Type (Etype (New_S))
4963 Typ := Etype (New_S);
4965 Typ := Etype (First_Formal (New_S));
4968 Btyp := Base_Type (Typ);
4970 if Nkind (Nam) /= N_Expanded_Name then
4971 return (In_Open_Scopes (Scope (Btyp))
4972 or else Is_Potentially_Use_Visible (Btyp)
4973 or else In_Use (Btyp)
4974 or else In_Use (Scope (Btyp)));
4977 Scop := Entity (Prefix (Nam));
4979 if Ekind (Scop) = E_Package
4980 and then Present (Renamed_Object (Scop))
4982 Scop := Renamed_Object (Scop);
4985 -- Operator is visible if prefix of expanded name denotes
4986 -- scope of type, or else type is defined in System_Aux
4987 -- and the prefix denotes System.
4989 return Scope (Btyp) = Scop
4990 or else (Scope (Btyp) = System_Aux_Id
4991 and then Scope (Scope (Btyp)) = Scop);
4994 end Is_Visible_Operation;
5000 function Within (Inner, Outer : Entity_Id) return Boolean is
5004 Sc := Scope (Inner);
5005 while Sc /= Standard_Standard loop
5016 ---------------------
5017 -- Report_Overload --
5018 ---------------------
5020 function Report_Overload return Entity_Id is
5024 ("ambiguous actual subprogram&, " &
5025 "possible interpretations:", N, Nam);
5028 ("ambiguous subprogram, " &
5029 "possible interpretations:", N);
5032 List_Interps (Nam, N);
5034 end Report_Overload;
5036 -- Start of processing for Find_Renamed_Entry
5040 Candidate_Renaming := Empty;
5042 if not Is_Overloaded (Nam) then
5043 if Entity_Matches_Spec (Entity (Nam), New_S)
5044 and then Is_Visible_Operation (Entity (Nam))
5046 Old_S := Entity (Nam);
5049 Present (First_Formal (Entity (Nam)))
5050 and then Present (First_Formal (New_S))
5051 and then (Base_Type (Etype (First_Formal (Entity (Nam))))
5052 = Base_Type (Etype (First_Formal (New_S))))
5054 Candidate_Renaming := Entity (Nam);
5058 Get_First_Interp (Nam, Ind, It);
5059 while Present (It.Nam) loop
5060 if Entity_Matches_Spec (It.Nam, New_S)
5061 and then Is_Visible_Operation (It.Nam)
5063 if Old_S /= Any_Id then
5065 -- Note: The call to Disambiguate only happens if a
5066 -- previous interpretation was found, in which case I1
5067 -- has received a value.
5069 It1 := Disambiguate (Nam, I1, Ind, Etype (Old_S));
5071 if It1 = No_Interp then
5072 Inst := Enclosing_Instance;
5074 if Present (Inst) then
5075 if Within (It.Nam, Inst) then
5077 elsif Within (Old_S, Inst) then
5080 return Report_Overload;
5084 return Report_Overload;
5098 Present (First_Formal (It.Nam))
5099 and then Present (First_Formal (New_S))
5100 and then (Base_Type (Etype (First_Formal (It.Nam)))
5101 = Base_Type (Etype (First_Formal (New_S))))
5103 Candidate_Renaming := It.Nam;
5106 Get_Next_Interp (Ind, It);
5109 Set_Entity (Nam, Old_S);
5110 Set_Is_Overloaded (Nam, False);
5114 end Find_Renamed_Entity;
5116 -----------------------------
5117 -- Find_Selected_Component --
5118 -----------------------------
5120 procedure Find_Selected_Component (N : Node_Id) is
5121 P : constant Node_Id := Prefix (N);
5124 -- Entity denoted by prefix
5134 if Nkind (P) = N_Error then
5137 -- If the selector already has an entity, the node has been constructed
5138 -- in the course of expansion, and is known to be valid. Do not verify
5139 -- that it is defined for the type (it may be a private component used
5140 -- in the expansion of record equality).
5142 elsif Present (Entity (Selector_Name (N))) then
5144 or else Etype (N) = Any_Type
5147 Sel_Name : constant Node_Id := Selector_Name (N);
5148 Selector : constant Entity_Id := Entity (Sel_Name);
5152 Set_Etype (Sel_Name, Etype (Selector));
5154 if not Is_Entity_Name (P) then
5158 -- Build an actual subtype except for the first parameter
5159 -- of an init proc, where this actual subtype is by
5160 -- definition incorrect, since the object is uninitialized
5161 -- (and does not even have defined discriminants etc.)
5163 if Is_Entity_Name (P)
5164 and then Ekind (Entity (P)) = E_Function
5166 Nam := New_Copy (P);
5168 if Is_Overloaded (P) then
5169 Save_Interps (P, Nam);
5173 Make_Function_Call (Sloc (P), Name => Nam));
5175 Analyze_Selected_Component (N);
5178 elsif Ekind (Selector) = E_Component
5179 and then (not Is_Entity_Name (P)
5180 or else Chars (Entity (P)) /= Name_uInit)
5183 Build_Actual_Subtype_Of_Component (
5184 Etype (Selector), N);
5189 if No (C_Etype) then
5190 C_Etype := Etype (Selector);
5192 Insert_Action (N, C_Etype);
5193 C_Etype := Defining_Identifier (C_Etype);
5196 Set_Etype (N, C_Etype);
5199 -- If this is the name of an entry or protected operation, and
5200 -- the prefix is an access type, insert an explicit dereference,
5201 -- so that entry calls are treated uniformly.
5203 if Is_Access_Type (Etype (P))
5204 and then Is_Concurrent_Type (Designated_Type (Etype (P)))
5207 New_P : constant Node_Id :=
5208 Make_Explicit_Dereference (Sloc (P),
5209 Prefix => Relocate_Node (P));
5212 Set_Etype (P, Designated_Type (Etype (Prefix (P))));
5216 -- If the selected component appears within a default expression
5217 -- and it has an actual subtype, the pre-analysis has not yet
5218 -- completed its analysis, because Insert_Actions is disabled in
5219 -- that context. Within the init proc of the enclosing type we
5220 -- must complete this analysis, if an actual subtype was created.
5222 elsif Inside_Init_Proc then
5224 Typ : constant Entity_Id := Etype (N);
5225 Decl : constant Node_Id := Declaration_Node (Typ);
5227 if Nkind (Decl) = N_Subtype_Declaration
5228 and then not Analyzed (Decl)
5229 and then Is_List_Member (Decl)
5230 and then No (Parent (Decl))
5233 Insert_Action (N, Decl);
5240 elsif Is_Entity_Name (P) then
5241 P_Name := Entity (P);
5243 -- The prefix may denote an enclosing type which is the completion
5244 -- of an incomplete type declaration.
5246 if Is_Type (P_Name) then
5247 Set_Entity (P, Get_Full_View (P_Name));
5248 Set_Etype (P, Entity (P));
5249 P_Name := Entity (P);
5252 P_Type := Base_Type (Etype (P));
5254 if Debug_Flag_E then
5255 Write_Str ("Found prefix type to be ");
5256 Write_Entity_Info (P_Type, " "); Write_Eol;
5259 -- First check for components of a record object (not the
5260 -- result of a call, which is handled below).
5262 if Is_Appropriate_For_Record (P_Type)
5263 and then not Is_Overloadable (P_Name)
5264 and then not Is_Type (P_Name)
5266 -- Selected component of record. Type checking will validate
5267 -- name of selector.
5268 -- ??? could we rewrite an implicit dereference into an explicit
5271 Analyze_Selected_Component (N);
5273 elsif Is_Appropriate_For_Entry_Prefix (P_Type)
5274 and then not In_Open_Scopes (P_Name)
5275 and then (not Is_Concurrent_Type (Etype (P_Name))
5276 or else not In_Open_Scopes (Etype (P_Name)))
5278 -- Call to protected operation or entry. Type checking is
5279 -- needed on the prefix.
5281 Analyze_Selected_Component (N);
5283 elsif (In_Open_Scopes (P_Name)
5284 and then Ekind (P_Name) /= E_Void
5285 and then not Is_Overloadable (P_Name))
5286 or else (Is_Concurrent_Type (Etype (P_Name))
5287 and then In_Open_Scopes (Etype (P_Name)))
5289 -- Prefix denotes an enclosing loop, block, or task, i.e. an
5290 -- enclosing construct that is not a subprogram or accept.
5292 Find_Expanded_Name (N);
5294 elsif Ekind (P_Name) = E_Package then
5295 Find_Expanded_Name (N);
5297 elsif Is_Overloadable (P_Name) then
5299 -- The subprogram may be a renaming (of an enclosing scope) as
5300 -- in the case of the name of the generic within an instantiation.
5302 if (Ekind (P_Name) = E_Procedure
5303 or else Ekind (P_Name) = E_Function)
5304 and then Present (Alias (P_Name))
5305 and then Is_Generic_Instance (Alias (P_Name))
5307 P_Name := Alias (P_Name);
5310 if Is_Overloaded (P) then
5312 -- The prefix must resolve to a unique enclosing construct
5315 Found : Boolean := False;
5320 Get_First_Interp (P, Ind, It);
5321 while Present (It.Nam) loop
5322 if In_Open_Scopes (It.Nam) then
5325 "prefix must be unique enclosing scope", N);
5326 Set_Entity (N, Any_Id);
5327 Set_Etype (N, Any_Type);
5336 Get_Next_Interp (Ind, It);
5341 if In_Open_Scopes (P_Name) then
5342 Set_Entity (P, P_Name);
5343 Set_Is_Overloaded (P, False);
5344 Find_Expanded_Name (N);
5347 -- If no interpretation as an expanded name is possible, it
5348 -- must be a selected component of a record returned by a
5349 -- function call. Reformat prefix as a function call, the rest
5350 -- is done by type resolution. If the prefix is procedure or
5351 -- entry, as is P.X; this is an error.
5353 if Ekind (P_Name) /= E_Function
5354 and then (not Is_Overloaded (P)
5356 Nkind (Parent (N)) = N_Procedure_Call_Statement)
5358 -- Prefix may mention a package that is hidden by a local
5359 -- declaration: let the user know. Scan the full homonym
5360 -- chain, the candidate package may be anywhere on it.
5362 if Present (Homonym (Current_Entity (P_Name))) then
5364 P_Name := Current_Entity (P_Name);
5366 while Present (P_Name) loop
5367 exit when Ekind (P_Name) = E_Package;
5368 P_Name := Homonym (P_Name);
5371 if Present (P_Name) then
5372 Error_Msg_Sloc := Sloc (Entity (Prefix (N)));
5375 ("package& is hidden by declaration#",
5378 Set_Entity (Prefix (N), P_Name);
5379 Find_Expanded_Name (N);
5382 P_Name := Entity (Prefix (N));
5387 ("invalid prefix in selected component&", N, P_Name);
5388 Change_Selected_Component_To_Expanded_Name (N);
5389 Set_Entity (N, Any_Id);
5390 Set_Etype (N, Any_Type);
5393 Nam := New_Copy (P);
5394 Save_Interps (P, Nam);
5396 Make_Function_Call (Sloc (P), Name => Nam));
5398 Analyze_Selected_Component (N);
5402 -- Remaining cases generate various error messages
5405 -- Format node as expanded name, to avoid cascaded errors
5407 Change_Selected_Component_To_Expanded_Name (N);
5408 Set_Entity (N, Any_Id);
5409 Set_Etype (N, Any_Type);
5411 -- Issue error message, but avoid this if error issued already.
5412 -- Use identifier of prefix if one is available.
5414 if P_Name = Any_Id then
5417 elsif Ekind (P_Name) = E_Void then
5418 Premature_Usage (P);
5420 elsif Nkind (P) /= N_Attribute_Reference then
5422 "invalid prefix in selected component&", P);
5424 if Is_Access_Type (P_Type)
5425 and then Ekind (Designated_Type (P_Type)) = E_Incomplete_Type
5428 ("\dereference must not be of an incomplete type " &
5434 "invalid prefix in selected component", P);
5439 -- If prefix is not the name of an entity, it must be an expression,
5440 -- whose type is appropriate for a record. This is determined by
5443 Analyze_Selected_Component (N);
5445 end Find_Selected_Component;
5451 procedure Find_Type (N : Node_Id) is
5461 elsif Nkind (N) = N_Attribute_Reference then
5463 -- Class attribute. This is not valid in Ada 83 mode, but we do not
5464 -- need to enforce that at this point, since the declaration of the
5465 -- tagged type in the prefix would have been flagged already.
5467 if Attribute_Name (N) = Name_Class then
5468 Check_Restriction (No_Dispatch, N);
5469 Find_Type (Prefix (N));
5471 -- Propagate error from bad prefix
5473 if Etype (Prefix (N)) = Any_Type then
5474 Set_Entity (N, Any_Type);
5475 Set_Etype (N, Any_Type);
5479 T := Base_Type (Entity (Prefix (N)));
5481 -- Case where type is not known to be tagged. Its appearance in
5482 -- the prefix of the 'Class attribute indicates that the full view
5485 if not Is_Tagged_Type (T) then
5486 if Ekind (T) = E_Incomplete_Type then
5488 -- It is legal to denote the class type of an incomplete
5489 -- type. The full type will have to be tagged, of course.
5490 -- In Ada 2005 this usage is declared obsolescent, so we
5491 -- warn accordingly.
5493 -- ??? This test is temporarily disabled (always False)
5494 -- because it causes an unwanted warning on GNAT sources
5495 -- (built with -gnatg, which includes Warn_On_Obsolescent_
5496 -- Feature). Once this issue is cleared in the sources, it
5499 if not Is_Tagged_Type (T)
5500 and then Ada_Version >= Ada_05
5501 and then Warn_On_Obsolescent_Feature
5505 ("applying 'Class to an untagged incomplete type"
5506 & " is an obsolescent feature (RM J.11)", N);
5509 Set_Is_Tagged_Type (T);
5510 Set_Primitive_Operations (T, New_Elmt_List);
5511 Make_Class_Wide_Type (T);
5512 Set_Entity (N, Class_Wide_Type (T));
5513 Set_Etype (N, Class_Wide_Type (T));
5515 elsif Ekind (T) = E_Private_Type
5516 and then not Is_Generic_Type (T)
5517 and then In_Private_Part (Scope (T))
5519 -- The Class attribute can be applied to an untagged private
5520 -- type fulfilled by a tagged type prior to the full type
5521 -- declaration (but only within the parent package's private
5522 -- part). Create the class-wide type now and check that the
5523 -- full type is tagged later during its analysis. Note that
5524 -- we do not mark the private type as tagged, unlike the
5525 -- case of incomplete types, because the type must still
5526 -- appear untagged to outside units.
5528 if No (Class_Wide_Type (T)) then
5529 Make_Class_Wide_Type (T);
5532 Set_Entity (N, Class_Wide_Type (T));
5533 Set_Etype (N, Class_Wide_Type (T));
5536 -- Should we introduce a type Any_Tagged and use Wrong_Type
5537 -- here, it would be a bit more consistent???
5540 ("tagged type required, found}",
5541 Prefix (N), First_Subtype (T));
5542 Set_Entity (N, Any_Type);
5546 -- Case of tagged type
5549 if Is_Concurrent_Type (T) then
5550 if No (Corresponding_Record_Type (Entity (Prefix (N)))) then
5552 -- Previous error. Use current type, which at least
5553 -- provides some operations.
5555 C := Entity (Prefix (N));
5558 C := Class_Wide_Type
5559 (Corresponding_Record_Type (Entity (Prefix (N))));
5563 C := Class_Wide_Type (Entity (Prefix (N)));
5566 Set_Entity_With_Style_Check (N, C);
5567 Generate_Reference (C, N);
5571 -- Base attribute, not allowed in Ada 83
5573 elsif Attribute_Name (N) = Name_Base then
5574 if Ada_Version = Ada_83 and then Comes_From_Source (N) then
5576 ("(Ada 83) Base attribute not allowed in subtype mark", N);
5579 Find_Type (Prefix (N));
5580 Typ := Entity (Prefix (N));
5582 if Ada_Version >= Ada_95
5583 and then not Is_Scalar_Type (Typ)
5584 and then not Is_Generic_Type (Typ)
5587 ("prefix of Base attribute must be scalar type",
5590 elsif Sloc (Typ) = Standard_Location
5591 and then Base_Type (Typ) = Typ
5592 and then Warn_On_Redundant_Constructs
5595 ("?redundant attribute, & is its own base type", N, Typ);
5598 T := Base_Type (Typ);
5600 -- Rewrite attribute reference with type itself (see similar
5601 -- processing in Analyze_Attribute, case Base). Preserve
5602 -- prefix if present, for other legality checks.
5604 if Nkind (Prefix (N)) = N_Expanded_Name then
5606 Make_Expanded_Name (Sloc (N),
5608 Prefix => New_Copy (Prefix (Prefix (N))),
5609 Selector_Name => New_Reference_To (T, Sloc (N))));
5612 Rewrite (N, New_Reference_To (T, Sloc (N)));
5619 elsif Attribute_Name (N) = Name_Stub_Type then
5621 -- This is handled in Analyze_Attribute
5625 -- All other attributes are invalid in a subtype mark
5628 Error_Msg_N ("invalid attribute in subtype mark", N);
5634 if Is_Entity_Name (N) then
5635 T_Name := Entity (N);
5637 Error_Msg_N ("subtype mark required in this context", N);
5638 Set_Etype (N, Any_Type);
5642 if T_Name = Any_Id or else Etype (N) = Any_Type then
5644 -- Undefined id. Make it into a valid type
5646 Set_Entity (N, Any_Type);
5648 elsif not Is_Type (T_Name)
5649 and then T_Name /= Standard_Void_Type
5651 Error_Msg_Sloc := Sloc (T_Name);
5652 Error_Msg_N ("subtype mark required in this context", N);
5653 Error_Msg_NE ("\\found & declared#", N, T_Name);
5654 Set_Entity (N, Any_Type);
5657 -- If the type is an incomplete type created to handle
5658 -- anonymous access components of a record type, then the
5659 -- incomplete type is the visible entity and subsequent
5660 -- references will point to it. Mark the original full
5661 -- type as referenced, to prevent spurious warnings.
5663 if Is_Incomplete_Type (T_Name)
5664 and then Present (Full_View (T_Name))
5665 and then not Comes_From_Source (T_Name)
5667 Set_Referenced (Full_View (T_Name));
5670 T_Name := Get_Full_View (T_Name);
5672 -- Ada 2005 (AI-251, AI-50217): Handle interfaces visible through
5673 -- limited-with clauses
5675 if From_With_Type (T_Name)
5676 and then Ekind (T_Name) in Incomplete_Kind
5677 and then Present (Non_Limited_View (T_Name))
5678 and then Is_Interface (Non_Limited_View (T_Name))
5680 T_Name := Non_Limited_View (T_Name);
5683 if In_Open_Scopes (T_Name) then
5684 if Ekind (Base_Type (T_Name)) = E_Task_Type then
5686 -- In Ada 2005, a task name can be used in an access
5687 -- definition within its own body.
5689 if Ada_Version >= Ada_05
5690 and then Nkind (Parent (N)) = N_Access_Definition
5692 Set_Entity (N, T_Name);
5693 Set_Etype (N, T_Name);
5698 ("task type cannot be used as type mark " &
5699 "within its own spec or body", N);
5702 elsif Ekind (Base_Type (T_Name)) = E_Protected_Type then
5704 -- In Ada 2005, a protected name can be used in an access
5705 -- definition within its own body.
5707 if Ada_Version >= Ada_05
5708 and then Nkind (Parent (N)) = N_Access_Definition
5710 Set_Entity (N, T_Name);
5711 Set_Etype (N, T_Name);
5716 ("protected type cannot be used as type mark " &
5717 "within its own spec or body", N);
5721 Error_Msg_N ("type declaration cannot refer to itself", N);
5724 Set_Etype (N, Any_Type);
5725 Set_Entity (N, Any_Type);
5726 Set_Error_Posted (T_Name);
5730 Set_Entity (N, T_Name);
5731 Set_Etype (N, T_Name);
5735 if Present (Etype (N)) and then Comes_From_Source (N) then
5736 if Is_Fixed_Point_Type (Etype (N)) then
5737 Check_Restriction (No_Fixed_Point, N);
5738 elsif Is_Floating_Point_Type (Etype (N)) then
5739 Check_Restriction (No_Floating_Point, N);
5744 ------------------------------------
5745 -- Has_Implicit_Character_Literal --
5746 ------------------------------------
5748 function Has_Implicit_Character_Literal (N : Node_Id) return Boolean is
5750 Found : Boolean := False;
5751 P : constant Entity_Id := Entity (Prefix (N));
5752 Priv_Id : Entity_Id := Empty;
5755 if Ekind (P) = E_Package
5756 and then not In_Open_Scopes (P)
5758 Priv_Id := First_Private_Entity (P);
5761 if P = Standard_Standard then
5762 Change_Selected_Component_To_Expanded_Name (N);
5763 Rewrite (N, Selector_Name (N));
5765 Set_Etype (Original_Node (N), Standard_Character);
5769 Id := First_Entity (P);
5771 and then Id /= Priv_Id
5773 if Is_Standard_Character_Type (Id)
5774 and then Id = Base_Type (Id)
5776 -- We replace the node with the literal itself, resolve as a
5777 -- character, and set the type correctly.
5780 Change_Selected_Component_To_Expanded_Name (N);
5781 Rewrite (N, Selector_Name (N));
5784 Set_Etype (Original_Node (N), Id);
5788 -- More than one type derived from Character in given scope.
5789 -- Collect all possible interpretations.
5791 Add_One_Interp (N, Id, Id);
5799 end Has_Implicit_Character_Literal;
5801 ----------------------
5802 -- Has_Private_With --
5803 ----------------------
5805 function Has_Private_With (E : Entity_Id) return Boolean is
5806 Comp_Unit : constant Node_Id := Cunit (Current_Sem_Unit);
5810 Item := First (Context_Items (Comp_Unit));
5811 while Present (Item) loop
5812 if Nkind (Item) = N_With_Clause
5813 and then Private_Present (Item)
5814 and then Entity (Name (Item)) = E
5823 end Has_Private_With;
5825 ---------------------------
5826 -- Has_Implicit_Operator --
5827 ---------------------------
5829 function Has_Implicit_Operator (N : Node_Id) return Boolean is
5830 Op_Id : constant Name_Id := Chars (Selector_Name (N));
5831 P : constant Entity_Id := Entity (Prefix (N));
5833 Priv_Id : Entity_Id := Empty;
5835 procedure Add_Implicit_Operator
5837 Op_Type : Entity_Id := Empty);
5838 -- Add implicit interpretation to node N, using the type for which a
5839 -- predefined operator exists. If the operator yields a boolean type,
5840 -- the Operand_Type is implicitly referenced by the operator, and a
5841 -- reference to it must be generated.
5843 ---------------------------
5844 -- Add_Implicit_Operator --
5845 ---------------------------
5847 procedure Add_Implicit_Operator
5849 Op_Type : Entity_Id := Empty)
5851 Predef_Op : Entity_Id;
5854 Predef_Op := Current_Entity (Selector_Name (N));
5856 while Present (Predef_Op)
5857 and then Scope (Predef_Op) /= Standard_Standard
5859 Predef_Op := Homonym (Predef_Op);
5862 if Nkind (N) = N_Selected_Component then
5863 Change_Selected_Component_To_Expanded_Name (N);
5866 Add_One_Interp (N, Predef_Op, T);
5868 -- For operators with unary and binary interpretations, add both
5870 if Present (Homonym (Predef_Op)) then
5871 Add_One_Interp (N, Homonym (Predef_Op), T);
5874 -- The node is a reference to a predefined operator, and
5875 -- an implicit reference to the type of its operands.
5877 if Present (Op_Type) then
5878 Generate_Operator_Reference (N, Op_Type);
5880 Generate_Operator_Reference (N, T);
5882 end Add_Implicit_Operator;
5884 -- Start of processing for Has_Implicit_Operator
5887 if Ekind (P) = E_Package
5888 and then not In_Open_Scopes (P)
5890 Priv_Id := First_Private_Entity (P);
5893 Id := First_Entity (P);
5897 -- Boolean operators: an implicit declaration exists if the scope
5898 -- contains a declaration for a derived Boolean type, or for an
5899 -- array of Boolean type.
5901 when Name_Op_And | Name_Op_Not | Name_Op_Or | Name_Op_Xor =>
5902 while Id /= Priv_Id loop
5903 if Valid_Boolean_Arg (Id)
5904 and then Id = Base_Type (Id)
5906 Add_Implicit_Operator (Id);
5913 -- Equality: look for any non-limited type (result is Boolean)
5915 when Name_Op_Eq | Name_Op_Ne =>
5916 while Id /= Priv_Id loop
5918 and then not Is_Limited_Type (Id)
5919 and then Id = Base_Type (Id)
5921 Add_Implicit_Operator (Standard_Boolean, Id);
5928 -- Comparison operators: scalar type, or array of scalar
5930 when Name_Op_Lt | Name_Op_Le | Name_Op_Gt | Name_Op_Ge =>
5931 while Id /= Priv_Id loop
5932 if (Is_Scalar_Type (Id)
5933 or else (Is_Array_Type (Id)
5934 and then Is_Scalar_Type (Component_Type (Id))))
5935 and then Id = Base_Type (Id)
5937 Add_Implicit_Operator (Standard_Boolean, Id);
5944 -- Arithmetic operators: any numeric type
5954 while Id /= Priv_Id loop
5955 if Is_Numeric_Type (Id)
5956 and then Id = Base_Type (Id)
5958 Add_Implicit_Operator (Id);
5965 -- Concatenation: any one-dimensional array type
5967 when Name_Op_Concat =>
5968 while Id /= Priv_Id loop
5969 if Is_Array_Type (Id) and then Number_Dimensions (Id) = 1
5970 and then Id = Base_Type (Id)
5972 Add_Implicit_Operator (Id);
5979 -- What is the others condition here? Should we be using a
5980 -- subtype of Name_Id that would restrict to operators ???
5982 when others => null;
5985 -- If we fall through, then we do not have an implicit operator
5989 end Has_Implicit_Operator;
5991 --------------------
5992 -- In_Open_Scopes --
5993 --------------------
5995 function In_Open_Scopes (S : Entity_Id) return Boolean is
5997 -- Several scope stacks are maintained by Scope_Stack. The base of the
5998 -- currently active scope stack is denoted by the Is_Active_Stack_Base
5999 -- flag in the scope stack entry. Note that the scope stacks used to
6000 -- simply be delimited implicitly by the presence of Standard_Standard
6001 -- at their base, but there now are cases where this is not sufficient
6002 -- because Standard_Standard actually may appear in the middle of the
6003 -- active set of scopes.
6005 for J in reverse 0 .. Scope_Stack.Last loop
6006 if Scope_Stack.Table (J).Entity = S then
6010 -- Check Is_Active_Stack_Base to tell us when to stop, as there are
6011 -- cases where Standard_Standard appears in the middle of the active
6012 -- set of scopes. This affects the declaration and overriding of
6013 -- private inherited operations in instantiations of generic child
6016 exit when Scope_Stack.Table (J).Is_Active_Stack_Base;
6022 -----------------------------
6023 -- Inherit_Renamed_Profile --
6024 -----------------------------
6026 procedure Inherit_Renamed_Profile (New_S : Entity_Id; Old_S : Entity_Id) is
6033 if Ekind (Old_S) = E_Operator then
6034 New_F := First_Formal (New_S);
6036 while Present (New_F) loop
6037 Set_Etype (New_F, Base_Type (Etype (New_F)));
6038 Next_Formal (New_F);
6041 Set_Etype (New_S, Base_Type (Etype (New_S)));
6044 New_F := First_Formal (New_S);
6045 Old_F := First_Formal (Old_S);
6047 while Present (New_F) loop
6048 New_T := Etype (New_F);
6049 Old_T := Etype (Old_F);
6051 -- If the new type is a renaming of the old one, as is the
6052 -- case for actuals in instances, retain its name, to simplify
6053 -- later disambiguation.
6055 if Nkind (Parent (New_T)) = N_Subtype_Declaration
6056 and then Is_Entity_Name (Subtype_Indication (Parent (New_T)))
6057 and then Entity (Subtype_Indication (Parent (New_T))) = Old_T
6061 Set_Etype (New_F, Old_T);
6064 Next_Formal (New_F);
6065 Next_Formal (Old_F);
6068 if Ekind (Old_S) = E_Function
6069 or else Ekind (Old_S) = E_Enumeration_Literal
6071 Set_Etype (New_S, Etype (Old_S));
6074 end Inherit_Renamed_Profile;
6080 procedure Initialize is
6085 -------------------------
6086 -- Install_Use_Clauses --
6087 -------------------------
6089 procedure Install_Use_Clauses
6091 Force_Installation : Boolean := False)
6099 while Present (U) loop
6101 -- Case of USE package
6103 if Nkind (U) = N_Use_Package_Clause then
6104 P := First (Names (U));
6105 while Present (P) loop
6108 if Ekind (Id) = E_Package then
6110 Note_Redundant_Use (P);
6112 elsif Present (Renamed_Object (Id))
6113 and then In_Use (Renamed_Object (Id))
6115 Note_Redundant_Use (P);
6117 elsif Force_Installation or else Applicable_Use (P) then
6118 Use_One_Package (Id, U);
6129 P := First (Subtype_Marks (U));
6130 while Present (P) loop
6131 if not Is_Entity_Name (P)
6132 or else No (Entity (P))
6136 elsif Entity (P) /= Any_Type then
6144 Next_Use_Clause (U);
6146 end Install_Use_Clauses;
6148 -------------------------------------
6149 -- Is_Appropriate_For_Entry_Prefix --
6150 -------------------------------------
6152 function Is_Appropriate_For_Entry_Prefix (T : Entity_Id) return Boolean is
6153 P_Type : Entity_Id := T;
6156 if Is_Access_Type (P_Type) then
6157 P_Type := Designated_Type (P_Type);
6160 return Is_Task_Type (P_Type) or else Is_Protected_Type (P_Type);
6161 end Is_Appropriate_For_Entry_Prefix;
6163 -------------------------------
6164 -- Is_Appropriate_For_Record --
6165 -------------------------------
6167 function Is_Appropriate_For_Record (T : Entity_Id) return Boolean is
6169 function Has_Components (T1 : Entity_Id) return Boolean;
6170 -- Determine if given type has components (i.e. is either a record
6171 -- type or a type that has discriminants).
6173 --------------------
6174 -- Has_Components --
6175 --------------------
6177 function Has_Components (T1 : Entity_Id) return Boolean is
6179 return Is_Record_Type (T1)
6180 or else (Is_Private_Type (T1) and then Has_Discriminants (T1))
6181 or else (Is_Task_Type (T1) and then Has_Discriminants (T1))
6182 or else (Is_Incomplete_Type (T1)
6183 and then From_With_Type (T1)
6184 and then Present (Non_Limited_View (T1))
6185 and then Is_Record_Type
6186 (Get_Full_View (Non_Limited_View (T1))));
6189 -- Start of processing for Is_Appropriate_For_Record
6194 and then (Has_Components (T)
6195 or else (Is_Access_Type (T)
6196 and then Has_Components (Designated_Type (T))));
6197 end Is_Appropriate_For_Record;
6199 ------------------------
6200 -- Note_Redundant_Use --
6201 ------------------------
6203 procedure Note_Redundant_Use (Clause : Node_Id) is
6204 Pack_Name : constant Entity_Id := Entity (Clause);
6205 Cur_Use : constant Node_Id := Current_Use_Clause (Pack_Name);
6206 Decl : constant Node_Id := Parent (Clause);
6208 Prev_Use : Node_Id := Empty;
6209 Redundant : Node_Id := Empty;
6210 -- The Use_Clause which is actually redundant. In the simplest case it
6211 -- is Pack itself, but when we compile a body we install its context
6212 -- before that of its spec, in which case it is the use_clause in the
6213 -- spec that will appear to be redundant, and we want the warning to be
6214 -- placed on the body. Similar complications appear when the redundancy
6215 -- is between a child unit and one of its ancestors.
6218 Set_Redundant_Use (Clause, True);
6220 if not Comes_From_Source (Clause)
6222 or else not Warn_On_Redundant_Constructs
6227 if not Is_Compilation_Unit (Current_Scope) then
6229 -- If the use_clause is in an inner scope, it is made redundant by
6230 -- some clause in the current context, with one exception: If we're
6231 -- compiling a nested package body, and the use_clause comes from the
6232 -- corresponding spec, the clause is not necessarily fully redundant,
6233 -- so we should not warn. If a warning was warranted, it would have
6234 -- been given when the spec was processed.
6236 if Nkind (Parent (Decl)) = N_Package_Specification then
6238 Package_Spec_Entity : constant Entity_Id :=
6239 Defining_Unit_Name (Parent (Decl));
6241 if In_Package_Body (Package_Spec_Entity) then
6247 Redundant := Clause;
6248 Prev_Use := Cur_Use;
6250 elsif Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Body then
6252 Cur_Unit : constant Unit_Number_Type := Get_Source_Unit (Cur_Use);
6253 New_Unit : constant Unit_Number_Type := Get_Source_Unit (Clause);
6257 if Cur_Unit = New_Unit then
6259 -- Redundant clause in same body
6261 Redundant := Clause;
6262 Prev_Use := Cur_Use;
6264 elsif Cur_Unit = Current_Sem_Unit then
6266 -- If the new clause is not in the current unit it has been
6267 -- analyzed first, and it makes the other one redundant.
6268 -- However, if the new clause appears in a subunit, Cur_Unit
6269 -- is still the parent, and in that case the redundant one
6270 -- is the one appearing in the subunit.
6272 if Nkind (Unit (Cunit (New_Unit))) = N_Subunit then
6273 Redundant := Clause;
6274 Prev_Use := Cur_Use;
6276 -- Most common case: redundant clause in body,
6277 -- original clause in spec. Current scope is spec entity.
6282 Unit (Library_Unit (Cunit (Current_Sem_Unit))))
6284 Redundant := Cur_Use;
6288 -- The new clause may appear in an unrelated unit, when
6289 -- the parents of a generic are being installed prior to
6290 -- instantiation. In this case there must be no warning.
6291 -- We detect this case by checking whether the current top
6292 -- of the stack is related to the current compilation.
6294 Scop := Current_Scope;
6295 while Present (Scop)
6296 and then Scop /= Standard_Standard
6298 if Is_Compilation_Unit (Scop)
6299 and then not Is_Child_Unit (Scop)
6303 elsif Scop = Cunit_Entity (Current_Sem_Unit) then
6307 Scop := Scope (Scop);
6310 Redundant := Cur_Use;
6314 elsif New_Unit = Current_Sem_Unit then
6315 Redundant := Clause;
6316 Prev_Use := Cur_Use;
6319 -- Neither is the current unit, so they appear in parent or
6320 -- sibling units. Warning will be emitted elsewhere.
6326 elsif Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Declaration
6327 and then Present (Parent_Spec (Unit (Cunit (Current_Sem_Unit))))
6329 -- Use_clause is in child unit of current unit, and the child unit
6330 -- appears in the context of the body of the parent, so it has been
6331 -- installed first, even though it is the redundant one. Depending on
6332 -- their placement in the context, the visible or the private parts
6333 -- of the two units, either might appear as redundant, but the
6334 -- message has to be on the current unit.
6336 if Get_Source_Unit (Cur_Use) = Current_Sem_Unit then
6337 Redundant := Cur_Use;
6340 Redundant := Clause;
6341 Prev_Use := Cur_Use;
6344 -- If the new use clause appears in the private part of a parent unit
6345 -- it may appear to be redundant w.r.t. a use clause in a child unit,
6346 -- but the previous use clause was needed in the visible part of the
6347 -- child, and no warning should be emitted.
6349 if Nkind (Parent (Decl)) = N_Package_Specification
6351 List_Containing (Decl) = Private_Declarations (Parent (Decl))
6354 Par : constant Entity_Id := Defining_Entity (Parent (Decl));
6355 Spec : constant Node_Id :=
6356 Specification (Unit (Cunit (Current_Sem_Unit)));
6359 if Is_Compilation_Unit (Par)
6360 and then Par /= Cunit_Entity (Current_Sem_Unit)
6361 and then Parent (Cur_Use) = Spec
6363 List_Containing (Cur_Use) = Visible_Declarations (Spec)
6370 -- Finally, if the current use clause is in the context then
6371 -- the clause is redundant when it is nested within the unit.
6373 elsif Nkind (Parent (Cur_Use)) = N_Compilation_Unit
6374 and then Nkind (Parent (Parent (Clause))) /= N_Compilation_Unit
6375 and then Get_Source_Unit (Cur_Use) = Get_Source_Unit (Clause)
6377 Redundant := Clause;
6378 Prev_Use := Cur_Use;
6384 if Present (Redundant) then
6385 Error_Msg_Sloc := Sloc (Prev_Use);
6387 ("& is already use-visible through previous use clause #?",
6388 Redundant, Pack_Name);
6390 end Note_Redundant_Use;
6396 procedure Pop_Scope is
6397 SST : Scope_Stack_Entry renames Scope_Stack.Table (Scope_Stack.Last);
6400 if Debug_Flag_E then
6404 Scope_Suppress := SST.Save_Scope_Suppress;
6405 Local_Suppress_Stack_Top := SST.Save_Local_Suppress_Stack_Top;
6406 Check_Policy_List := SST.Save_Check_Policy_List;
6408 if Debug_Flag_W then
6409 Write_Str ("--> exiting scope: ");
6410 Write_Name (Chars (Current_Scope));
6411 Write_Str (", Depth=");
6412 Write_Int (Int (Scope_Stack.Last));
6416 End_Use_Clauses (SST.First_Use_Clause);
6418 -- If the actions to be wrapped are still there they will get lost
6419 -- causing incomplete code to be generated. It is better to abort in
6420 -- this case (and we do the abort even with assertions off since the
6421 -- penalty is incorrect code generation)
6423 if SST.Actions_To_Be_Wrapped_Before /= No_List
6425 SST.Actions_To_Be_Wrapped_After /= No_List
6430 -- Free last subprogram name if allocated, and pop scope
6432 Free (SST.Last_Subprogram_Name);
6433 Scope_Stack.Decrement_Last;
6440 procedure Push_Scope (S : Entity_Id) is
6444 if Ekind (S) = E_Void then
6447 -- Set scope depth if not a non-concurrent type, and we have not yet set
6448 -- the scope depth. This means that we have the first occurrence of the
6449 -- scope, and this is where the depth is set.
6451 elsif (not Is_Type (S) or else Is_Concurrent_Type (S))
6452 and then not Scope_Depth_Set (S)
6454 if S = Standard_Standard then
6455 Set_Scope_Depth_Value (S, Uint_0);
6457 elsif Is_Child_Unit (S) then
6458 Set_Scope_Depth_Value (S, Uint_1);
6460 elsif not Is_Record_Type (Current_Scope) then
6461 if Ekind (S) = E_Loop then
6462 Set_Scope_Depth_Value (S, Scope_Depth (Current_Scope));
6464 Set_Scope_Depth_Value (S, Scope_Depth (Current_Scope) + 1);
6469 Scope_Stack.Increment_Last;
6472 SST : Scope_Stack_Entry renames Scope_Stack.Table (Scope_Stack.Last);
6476 SST.Save_Scope_Suppress := Scope_Suppress;
6477 SST.Save_Local_Suppress_Stack_Top := Local_Suppress_Stack_Top;
6478 SST.Save_Check_Policy_List := Check_Policy_List;
6480 if Scope_Stack.Last > Scope_Stack.First then
6481 SST.Component_Alignment_Default := Scope_Stack.Table
6482 (Scope_Stack.Last - 1).
6483 Component_Alignment_Default;
6486 SST.Last_Subprogram_Name := null;
6487 SST.Is_Transient := False;
6488 SST.Node_To_Be_Wrapped := Empty;
6489 SST.Pending_Freeze_Actions := No_List;
6490 SST.Actions_To_Be_Wrapped_Before := No_List;
6491 SST.Actions_To_Be_Wrapped_After := No_List;
6492 SST.First_Use_Clause := Empty;
6493 SST.Is_Active_Stack_Base := False;
6494 SST.Previous_Visibility := False;
6497 if Debug_Flag_W then
6498 Write_Str ("--> new scope: ");
6499 Write_Name (Chars (Current_Scope));
6500 Write_Str (", Id=");
6501 Write_Int (Int (Current_Scope));
6502 Write_Str (", Depth=");
6503 Write_Int (Int (Scope_Stack.Last));
6507 -- Deal with copying flags from the previous scope to this one. This is
6508 -- not necessary if either scope is standard, or if the new scope is a
6511 if S /= Standard_Standard
6512 and then Scope (S) /= Standard_Standard
6513 and then not Is_Child_Unit (S)
6517 if Nkind (E) not in N_Entity then
6521 -- Copy categorization flags from Scope (S) to S, this is not done
6522 -- when Scope (S) is Standard_Standard since propagation is from
6523 -- library unit entity inwards. Copy other relevant attributes as
6524 -- well (Discard_Names in particular).
6526 -- We only propagate inwards for library level entities,
6527 -- inner level subprograms do not inherit the categorization.
6529 if Is_Library_Level_Entity (S) then
6530 Set_Is_Preelaborated (S, Is_Preelaborated (E));
6531 Set_Is_Shared_Passive (S, Is_Shared_Passive (E));
6532 Set_Discard_Names (S, Discard_Names (E));
6533 Set_Suppress_Value_Tracking_On_Call
6534 (S, Suppress_Value_Tracking_On_Call (E));
6535 Set_Categorization_From_Scope (E => S, Scop => E);
6540 ---------------------
6541 -- Premature_Usage --
6542 ---------------------
6544 procedure Premature_Usage (N : Node_Id) is
6545 Kind : constant Node_Kind := Nkind (Parent (Entity (N)));
6546 E : Entity_Id := Entity (N);
6549 -- Within an instance, the analysis of the actual for a formal object
6550 -- does not see the name of the object itself. This is significant only
6551 -- if the object is an aggregate, where its analysis does not do any
6552 -- name resolution on component associations. (see 4717-008). In such a
6553 -- case, look for the visible homonym on the chain.
6556 and then Present (Homonym (E))
6561 and then not In_Open_Scopes (Scope (E))
6568 Set_Etype (N, Etype (E));
6573 if Kind = N_Component_Declaration then
6575 ("component&! cannot be used before end of record declaration", N);
6577 elsif Kind = N_Parameter_Specification then
6579 ("formal parameter&! cannot be used before end of specification",
6582 elsif Kind = N_Discriminant_Specification then
6584 ("discriminant&! cannot be used before end of discriminant part",
6587 elsif Kind = N_Procedure_Specification
6588 or else Kind = N_Function_Specification
6591 ("subprogram&! cannot be used before end of its declaration",
6594 elsif Kind = N_Full_Type_Declaration then
6596 ("type& cannot be used before end of its declaration!", N);
6600 ("object& cannot be used before end of its declaration!", N);
6602 end Premature_Usage;
6604 ------------------------
6605 -- Present_System_Aux --
6606 ------------------------
6608 function Present_System_Aux (N : Node_Id := Empty) return Boolean is
6610 Aux_Name : Unit_Name_Type;
6611 Unum : Unit_Number_Type;
6616 function Find_System (C_Unit : Node_Id) return Entity_Id;
6617 -- Scan context clause of compilation unit to find with_clause
6624 function Find_System (C_Unit : Node_Id) return Entity_Id is
6625 With_Clause : Node_Id;
6628 With_Clause := First (Context_Items (C_Unit));
6629 while Present (With_Clause) loop
6630 if (Nkind (With_Clause) = N_With_Clause
6631 and then Chars (Name (With_Clause)) = Name_System)
6632 and then Comes_From_Source (With_Clause)
6643 -- Start of processing for Present_System_Aux
6646 -- The child unit may have been loaded and analyzed already
6648 if Present (System_Aux_Id) then
6651 -- If no previous pragma for System.Aux, nothing to load
6653 elsif No (System_Extend_Unit) then
6656 -- Use the unit name given in the pragma to retrieve the unit.
6657 -- Verify that System itself appears in the context clause of the
6658 -- current compilation. If System is not present, an error will
6659 -- have been reported already.
6662 With_Sys := Find_System (Cunit (Current_Sem_Unit));
6664 The_Unit := Unit (Cunit (Current_Sem_Unit));
6668 (Nkind (The_Unit) = N_Package_Body
6669 or else (Nkind (The_Unit) = N_Subprogram_Body
6671 not Acts_As_Spec (Cunit (Current_Sem_Unit))))
6673 With_Sys := Find_System (Library_Unit (Cunit (Current_Sem_Unit)));
6677 and then Present (N)
6679 -- If we are compiling a subunit, we need to examine its
6680 -- context as well (Current_Sem_Unit is the parent unit);
6682 The_Unit := Parent (N);
6683 while Nkind (The_Unit) /= N_Compilation_Unit loop
6684 The_Unit := Parent (The_Unit);
6687 if Nkind (Unit (The_Unit)) = N_Subunit then
6688 With_Sys := Find_System (The_Unit);
6692 if No (With_Sys) then
6696 Loc := Sloc (With_Sys);
6697 Get_Name_String (Chars (Expression (System_Extend_Unit)));
6698 Name_Buffer (8 .. Name_Len + 7) := Name_Buffer (1 .. Name_Len);
6699 Name_Buffer (1 .. 7) := "system.";
6700 Name_Buffer (Name_Len + 8) := '%';
6701 Name_Buffer (Name_Len + 9) := 's';
6702 Name_Len := Name_Len + 9;
6703 Aux_Name := Name_Find;
6707 (Load_Name => Aux_Name,
6710 Error_Node => With_Sys);
6712 if Unum /= No_Unit then
6713 Semantics (Cunit (Unum));
6715 Defining_Entity (Specification (Unit (Cunit (Unum))));
6718 Make_With_Clause (Loc,
6720 Make_Expanded_Name (Loc,
6721 Chars => Chars (System_Aux_Id),
6722 Prefix => New_Reference_To (Scope (System_Aux_Id), Loc),
6723 Selector_Name => New_Reference_To (System_Aux_Id, Loc)));
6725 Set_Entity (Name (Withn), System_Aux_Id);
6727 Set_Library_Unit (Withn, Cunit (Unum));
6728 Set_Corresponding_Spec (Withn, System_Aux_Id);
6729 Set_First_Name (Withn, True);
6730 Set_Implicit_With (Withn, True);
6732 Insert_After (With_Sys, Withn);
6733 Mark_Rewrite_Insertion (Withn);
6734 Set_Context_Installed (Withn);
6738 -- Here if unit load failed
6741 Error_Msg_Name_1 := Name_System;
6742 Error_Msg_Name_2 := Chars (Expression (System_Extend_Unit));
6744 ("extension package `%.%` does not exist",
6745 Opt.System_Extend_Unit);
6749 end Present_System_Aux;
6751 -------------------------
6752 -- Restore_Scope_Stack --
6753 -------------------------
6755 procedure Restore_Scope_Stack (Handle_Use : Boolean := True) is
6758 Comp_Unit : Node_Id;
6759 In_Child : Boolean := False;
6760 Full_Vis : Boolean := True;
6761 SS_Last : constant Int := Scope_Stack.Last;
6764 -- Restore visibility of previous scope stack, if any
6766 for J in reverse 0 .. Scope_Stack.Last loop
6767 exit when Scope_Stack.Table (J).Entity = Standard_Standard
6768 or else No (Scope_Stack.Table (J).Entity);
6770 S := Scope_Stack.Table (J).Entity;
6772 if not Is_Hidden_Open_Scope (S) then
6774 -- If the parent scope is hidden, its entities are hidden as
6775 -- well, unless the entity is the instantiation currently
6778 if not Is_Hidden_Open_Scope (Scope (S))
6779 or else not Analyzed (Parent (S))
6780 or else Scope (S) = Standard_Standard
6782 Set_Is_Immediately_Visible (S, True);
6785 E := First_Entity (S);
6786 while Present (E) loop
6787 if Is_Child_Unit (E) then
6788 if not From_With_Type (E) then
6789 Set_Is_Immediately_Visible (E,
6790 Is_Visible_Child_Unit (E) or else In_Open_Scopes (E));
6794 (Nkind (Parent (E)) = N_Defining_Program_Unit_Name
6796 Nkind (Parent (Parent (E))) = N_Package_Specification);
6797 Set_Is_Immediately_Visible (E,
6798 Limited_View_Installed (Parent (Parent (E))));
6801 Set_Is_Immediately_Visible (E, True);
6807 and then Is_Package_Or_Generic_Package (S)
6809 -- We are in the visible part of the package scope
6811 exit when E = First_Private_Entity (S);
6815 -- The visibility of child units (siblings of current compilation)
6816 -- must be restored in any case. Their declarations may appear
6817 -- after the private part of the parent.
6819 if not Full_Vis then
6820 while Present (E) loop
6821 if Is_Child_Unit (E) then
6822 Set_Is_Immediately_Visible (E,
6823 Is_Visible_Child_Unit (E) or else In_Open_Scopes (E));
6831 if Is_Child_Unit (S)
6832 and not In_Child -- check only for current unit
6836 -- Restore visibility of parents according to whether the child
6837 -- is private and whether we are in its visible part.
6839 Comp_Unit := Parent (Unit_Declaration_Node (S));
6841 if Nkind (Comp_Unit) = N_Compilation_Unit
6842 and then Private_Present (Comp_Unit)
6846 elsif Is_Package_Or_Generic_Package (S)
6847 and then (In_Private_Part (S) or else In_Package_Body (S))
6851 -- if S is the scope of some instance (which has already been
6852 -- seen on the stack) it does not affect the visibility of
6855 elsif Is_Hidden_Open_Scope (S) then
6858 elsif (Ekind (S) = E_Procedure
6859 or else Ekind (S) = E_Function)
6860 and then Has_Completion (S)
6871 if SS_Last >= Scope_Stack.First
6872 and then Scope_Stack.Table (SS_Last).Entity /= Standard_Standard
6875 Install_Use_Clauses (Scope_Stack.Table (SS_Last).First_Use_Clause);
6877 end Restore_Scope_Stack;
6879 ----------------------
6880 -- Save_Scope_Stack --
6881 ----------------------
6883 procedure Save_Scope_Stack (Handle_Use : Boolean := True) is
6886 SS_Last : constant Int := Scope_Stack.Last;
6889 if SS_Last >= Scope_Stack.First
6890 and then Scope_Stack.Table (SS_Last).Entity /= Standard_Standard
6893 End_Use_Clauses (Scope_Stack.Table (SS_Last).First_Use_Clause);
6896 -- If the call is from within a compilation unit, as when called from
6897 -- Rtsfind, make current entries in scope stack invisible while we
6898 -- analyze the new unit.
6900 for J in reverse 0 .. SS_Last loop
6901 exit when Scope_Stack.Table (J).Entity = Standard_Standard
6902 or else No (Scope_Stack.Table (J).Entity);
6904 S := Scope_Stack.Table (J).Entity;
6905 Set_Is_Immediately_Visible (S, False);
6907 E := First_Entity (S);
6908 while Present (E) loop
6909 Set_Is_Immediately_Visible (E, False);
6915 end Save_Scope_Stack;
6921 procedure Set_Use (L : List_Id) is
6923 Pack_Name : Node_Id;
6930 while Present (Decl) loop
6931 if Nkind (Decl) = N_Use_Package_Clause then
6932 Chain_Use_Clause (Decl);
6934 Pack_Name := First (Names (Decl));
6935 while Present (Pack_Name) loop
6936 Pack := Entity (Pack_Name);
6938 if Ekind (Pack) = E_Package
6939 and then Applicable_Use (Pack_Name)
6941 Use_One_Package (Pack, Decl);
6947 elsif Nkind (Decl) = N_Use_Type_Clause then
6948 Chain_Use_Clause (Decl);
6950 Id := First (Subtype_Marks (Decl));
6951 while Present (Id) loop
6952 if Entity (Id) /= Any_Type then
6965 ---------------------
6966 -- Use_One_Package --
6967 ---------------------
6969 procedure Use_One_Package (P : Entity_Id; N : Node_Id) is
6972 Current_Instance : Entity_Id := Empty;
6974 Private_With_OK : Boolean := False;
6977 if Ekind (P) /= E_Package then
6982 Set_Current_Use_Clause (P, N);
6984 -- Ada 2005 (AI-50217): Check restriction
6986 if From_With_Type (P) then
6987 Error_Msg_N ("limited withed package cannot appear in use clause", N);
6990 -- Find enclosing instance, if any
6993 Current_Instance := Current_Scope;
6994 while not Is_Generic_Instance (Current_Instance) loop
6995 Current_Instance := Scope (Current_Instance);
6998 if No (Hidden_By_Use_Clause (N)) then
6999 Set_Hidden_By_Use_Clause (N, New_Elmt_List);
7003 -- If unit is a package renaming, indicate that the renamed
7004 -- package is also in use (the flags on both entities must
7005 -- remain consistent, and a subsequent use of either of them
7006 -- should be recognized as redundant).
7008 if Present (Renamed_Object (P)) then
7009 Set_In_Use (Renamed_Object (P));
7010 Set_Current_Use_Clause (Renamed_Object (P), N);
7011 Real_P := Renamed_Object (P);
7016 -- Ada 2005 (AI-262): Check the use_clause of a private withed package
7017 -- found in the private part of a package specification
7019 if In_Private_Part (Current_Scope)
7020 and then Has_Private_With (P)
7021 and then Is_Child_Unit (Current_Scope)
7022 and then Is_Child_Unit (P)
7023 and then Is_Ancestor_Package (Scope (Current_Scope), P)
7025 Private_With_OK := True;
7028 -- Loop through entities in one package making them potentially
7031 Id := First_Entity (P);
7033 and then (Id /= First_Private_Entity (P)
7034 or else Private_With_OK) -- Ada 2005 (AI-262)
7036 Prev := Current_Entity (Id);
7037 while Present (Prev) loop
7038 if Is_Immediately_Visible (Prev)
7039 and then (not Is_Overloadable (Prev)
7040 or else not Is_Overloadable (Id)
7041 or else (Type_Conformant (Id, Prev)))
7043 if No (Current_Instance) then
7045 -- Potentially use-visible entity remains hidden
7047 goto Next_Usable_Entity;
7049 -- A use clause within an instance hides outer global entities,
7050 -- which are not used to resolve local entities in the
7051 -- instance. Note that the predefined entities in Standard
7052 -- could not have been hidden in the generic by a use clause,
7053 -- and therefore remain visible. Other compilation units whose
7054 -- entities appear in Standard must be hidden in an instance.
7056 -- To determine whether an entity is external to the instance
7057 -- we compare the scope depth of its scope with that of the
7058 -- current instance. However, a generic actual of a subprogram
7059 -- instance is declared in the wrapper package but will not be
7060 -- hidden by a use-visible entity.
7062 -- If Id is called Standard, the predefined package with the
7063 -- same name is in the homonym chain. It has to be ignored
7064 -- because it has no defined scope (being the only entity in
7065 -- the system with this mandated behavior).
7067 elsif not Is_Hidden (Id)
7068 and then Present (Scope (Prev))
7069 and then not Is_Wrapper_Package (Scope (Prev))
7070 and then Scope_Depth (Scope (Prev)) <
7071 Scope_Depth (Current_Instance)
7072 and then (Scope (Prev) /= Standard_Standard
7073 or else Sloc (Prev) > Standard_Location)
7075 Set_Is_Potentially_Use_Visible (Id);
7076 Set_Is_Immediately_Visible (Prev, False);
7077 Append_Elmt (Prev, Hidden_By_Use_Clause (N));
7080 -- A user-defined operator is not use-visible if the predefined
7081 -- operator for the type is immediately visible, which is the case
7082 -- if the type of the operand is in an open scope. This does not
7083 -- apply to user-defined operators that have operands of different
7084 -- types, because the predefined mixed mode operations (multiply
7085 -- and divide) apply to universal types and do not hide anything.
7087 elsif Ekind (Prev) = E_Operator
7088 and then Operator_Matches_Spec (Prev, Id)
7089 and then In_Open_Scopes
7090 (Scope (Base_Type (Etype (First_Formal (Id)))))
7091 and then (No (Next_Formal (First_Formal (Id)))
7092 or else Etype (First_Formal (Id))
7093 = Etype (Next_Formal (First_Formal (Id)))
7094 or else Chars (Prev) = Name_Op_Expon)
7096 goto Next_Usable_Entity;
7098 -- In an instance, two homonyms may become use_visible through the
7099 -- actuals of distinct formal packages. In the generic, only the
7100 -- current one would have been visible, so make the other one
7103 elsif Present (Current_Instance)
7104 and then Is_Potentially_Use_Visible (Prev)
7105 and then not Is_Overloadable (Prev)
7106 and then Scope (Id) /= Scope (Prev)
7107 and then Used_As_Generic_Actual (Scope (Prev))
7108 and then Used_As_Generic_Actual (Scope (Id))
7109 and then List_Containing (Current_Use_Clause (Scope (Prev))) /=
7110 List_Containing (Current_Use_Clause (Scope (Id)))
7112 Set_Is_Potentially_Use_Visible (Prev, False);
7113 Append_Elmt (Prev, Hidden_By_Use_Clause (N));
7116 Prev := Homonym (Prev);
7119 -- On exit, we know entity is not hidden, unless it is private
7121 if not Is_Hidden (Id)
7122 and then ((not Is_Child_Unit (Id))
7123 or else Is_Visible_Child_Unit (Id))
7125 Set_Is_Potentially_Use_Visible (Id);
7127 if Is_Private_Type (Id)
7128 and then Present (Full_View (Id))
7130 Set_Is_Potentially_Use_Visible (Full_View (Id));
7134 <<Next_Usable_Entity>>
7138 -- Child units are also made use-visible by a use clause, but they may
7139 -- appear after all visible declarations in the parent entity list.
7141 while Present (Id) loop
7142 if Is_Child_Unit (Id)
7143 and then Is_Visible_Child_Unit (Id)
7145 Set_Is_Potentially_Use_Visible (Id);
7151 if Chars (Real_P) = Name_System
7152 and then Scope (Real_P) = Standard_Standard
7153 and then Present_System_Aux (N)
7155 Use_One_Package (System_Aux_Id, N);
7158 end Use_One_Package;
7164 procedure Use_One_Type (Id : Node_Id) is
7166 Is_Known_Used : Boolean;
7170 function Spec_Reloaded_For_Body return Boolean;
7171 -- Determine whether the compilation unit is a package body and the use
7172 -- type clause is in the spec of the same package. Even though the spec
7173 -- was analyzed first, its context is reloaded when analysing the body.
7175 ----------------------------
7176 -- Spec_Reloaded_For_Body --
7177 ----------------------------
7179 function Spec_Reloaded_For_Body return Boolean is
7181 if Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Body then
7183 Spec : constant Node_Id :=
7184 Parent (List_Containing (Parent (Id)));
7187 Nkind (Spec) = N_Package_Specification
7188 and then Corresponding_Body (Parent (Spec)) =
7189 Cunit_Entity (Current_Sem_Unit);
7194 end Spec_Reloaded_For_Body;
7196 -- Start of processing for Use_One_Type;
7199 -- It is the type determined by the subtype mark (8.4(8)) whose
7200 -- operations become potentially use-visible.
7202 T := Base_Type (Entity (Id));
7204 -- Either the type itself is used, the package where it is declared
7205 -- is in use or the entity is declared in the current package, thus
7210 or else In_Use (Scope (T))
7211 or else Scope (T) = Current_Scope;
7213 Set_Redundant_Use (Id,
7214 Is_Known_Used or else Is_Potentially_Use_Visible (T));
7216 if Ekind (T) = E_Incomplete_Type then
7217 Error_Msg_N ("premature usage of incomplete type", Id);
7219 elsif In_Open_Scopes (Scope (T)) then
7222 -- A limited view cannot appear in a use_type clause. However, an access
7223 -- type whose designated type is limited has the flag but is not itself
7224 -- a limited view unless we only have a limited view of its enclosing
7227 elsif From_With_Type (T)
7228 and then From_With_Type (Scope (T))
7231 ("incomplete type from limited view "
7232 & "cannot appear in use clause", Id);
7234 -- If the subtype mark designates a subtype in a different package,
7235 -- we have to check that the parent type is visible, otherwise the
7236 -- use type clause is a noop. Not clear how to do that???
7238 elsif not Redundant_Use (Id) then
7241 -- If T is tagged, primitive operators on class-wide operands
7242 -- are also available.
7244 if Is_Tagged_Type (T) then
7245 Set_In_Use (Class_Wide_Type (T));
7248 Set_Current_Use_Clause (T, Parent (Id));
7249 Op_List := Collect_Primitive_Operations (T);
7251 Elmt := First_Elmt (Op_List);
7252 while Present (Elmt) loop
7253 if (Nkind (Node (Elmt)) = N_Defining_Operator_Symbol
7254 or else Chars (Node (Elmt)) in Any_Operator_Name)
7255 and then not Is_Hidden (Node (Elmt))
7257 Set_Is_Potentially_Use_Visible (Node (Elmt));
7264 -- If warning on redundant constructs, check for unnecessary WITH
7266 if Warn_On_Redundant_Constructs
7267 and then Is_Known_Used
7269 -- with P; with P; use P;
7270 -- package P is package X is package body X is
7271 -- type T ... use P.T;
7273 -- The compilation unit is the body of X. GNAT first compiles the
7274 -- spec of X, then proceeds to the body. At that point P is marked
7275 -- as use visible. The analysis then reinstalls the spec along with
7276 -- its context. The use clause P.T is now recognized as redundant,
7277 -- but in the wrong context. Do not emit a warning in such cases.
7278 -- Do not emit a warning either if we are in an instance, there is
7279 -- no redundancy between an outer use_clause and one that appears
7280 -- within the generic.
7282 and then not Spec_Reloaded_For_Body
7283 and then not In_Instance
7285 -- The type already has a use clause
7289 -- Case where we know the current use clause for the type
7291 if Present (Current_Use_Clause (T)) then
7292 Use_Clause_Known : declare
7293 Clause1 : constant Node_Id := Parent (Id);
7294 Clause2 : constant Node_Id := Current_Use_Clause (T);
7301 function Entity_Of_Unit (U : Node_Id) return Entity_Id;
7302 -- Return the appropriate entity for determining which unit
7303 -- has a deeper scope: the defining entity for U, unless U
7304 -- is a package instance, in which case we retrieve the
7305 -- entity of the instance spec.
7307 --------------------
7308 -- Entity_Of_Unit --
7309 --------------------
7311 function Entity_Of_Unit (U : Node_Id) return Entity_Id is
7313 if Nkind (U) = N_Package_Instantiation
7314 and then Analyzed (U)
7316 return Defining_Entity (Instance_Spec (U));
7318 return Defining_Entity (U);
7322 -- Start of processing for Use_Clause_Known
7325 -- If both current use type clause and the use type clause
7326 -- for the type are at the compilation unit level, one of
7327 -- the units must be an ancestor of the other, and the
7328 -- warning belongs on the descendant.
7330 if Nkind (Parent (Clause1)) = N_Compilation_Unit
7332 Nkind (Parent (Clause2)) = N_Compilation_Unit
7335 -- If the unit is a subprogram body that acts as spec,
7336 -- the context clause is shared with the constructed
7337 -- subprogram spec. Clearly there is no redundancy.
7339 if Clause1 = Clause2 then
7343 Unit1 := Unit (Parent (Clause1));
7344 Unit2 := Unit (Parent (Clause2));
7346 -- If both clauses are on same unit, or one is the body
7347 -- of the other, or one of them is in a subunit, report
7348 -- redundancy on the later one.
7350 if Unit1 = Unit2 then
7351 Error_Msg_Sloc := Sloc (Current_Use_Clause (T));
7353 ("& is already use-visible through previous "
7354 & "use_type_clause #?", Clause1, T);
7357 elsif Nkind (Unit1) = N_Subunit then
7358 Error_Msg_Sloc := Sloc (Current_Use_Clause (T));
7360 ("& is already use-visible through previous "
7361 & "use_type_clause #?", Clause1, T);
7364 elsif Nkind_In (Unit2, N_Package_Body, N_Subprogram_Body)
7365 and then Nkind (Unit1) /= Nkind (Unit2)
7366 and then Nkind (Unit1) /= N_Subunit
7368 Error_Msg_Sloc := Sloc (Clause1);
7370 ("& is already use-visible through previous "
7371 & "use_type_clause #?", Current_Use_Clause (T), T);
7375 -- There is a redundant use type clause in a child unit.
7376 -- Determine which of the units is more deeply nested.
7377 -- If a unit is a package instance, retrieve the entity
7378 -- and its scope from the instance spec.
7380 Ent1 := Entity_Of_Unit (Unit1);
7381 Ent2 := Entity_Of_Unit (Unit2);
7383 if Scope (Ent2) = Standard_Standard then
7384 Error_Msg_Sloc := Sloc (Current_Use_Clause (T));
7387 elsif Scope (Ent1) = Standard_Standard then
7388 Error_Msg_Sloc := Sloc (Id);
7391 -- If both units are child units, we determine which one
7392 -- is the descendant by the scope distance to the
7393 -- ultimate parent unit.
7402 while S1 /= Standard_Standard
7404 S2 /= Standard_Standard
7410 if S1 = Standard_Standard then
7411 Error_Msg_Sloc := Sloc (Id);
7414 Error_Msg_Sloc := Sloc (Current_Use_Clause (T));
7421 ("& is already use-visible through previous "
7422 & "use_type_clause #?", Err_No, Id);
7424 -- Case where current use type clause and the use type
7425 -- clause for the type are not both at the compilation unit
7426 -- level. In this case we don't have location information.
7430 ("& is already use-visible through previous "
7431 & "use type clause?", Id, T);
7433 end Use_Clause_Known;
7435 -- Here if Current_Use_Clause is not set for T, another case
7436 -- where we do not have the location information available.
7440 ("& is already use-visible through previous "
7441 & "use type clause?", Id, T);
7444 -- The package where T is declared is already used
7446 elsif In_Use (Scope (T)) then
7447 Error_Msg_Sloc := Sloc (Current_Use_Clause (Scope (T)));
7449 ("& is already use-visible through package use clause #?",
7452 -- The current scope is the package where T is declared
7455 Error_Msg_Node_2 := Scope (T);
7457 ("& is already use-visible inside package &?", Id, T);
7466 procedure Write_Info is
7467 Id : Entity_Id := First_Entity (Current_Scope);
7470 -- No point in dumping standard entities
7472 if Current_Scope = Standard_Standard then
7476 Write_Str ("========================================================");
7478 Write_Str (" Defined Entities in ");
7479 Write_Name (Chars (Current_Scope));
7481 Write_Str ("========================================================");
7485 Write_Str ("-- none --");
7489 while Present (Id) loop
7490 Write_Entity_Info (Id, " ");
7495 if Scope (Current_Scope) = Standard_Standard then
7497 -- Print information on the current unit itself
7499 Write_Entity_Info (Current_Scope, " ");
7509 procedure Write_Scopes is
7512 for J in reverse 1 .. Scope_Stack.Last loop
7513 S := Scope_Stack.Table (J).Entity;
7514 Write_Int (Int (S));
7515 Write_Str (" === ");
7516 Write_Name (Chars (S));
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