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. Some errors
870 -- and warnings are produced only for calls that come from source.
872 if Nkind (Nam) = N_Function_Call then
875 -- Usage is illegal in Ada 83
878 if Comes_From_Source (Nam) then
880 ("(Ada 83) cannot rename function return object", Nam);
883 -- In Ada 95, warn for odd case of renaming parameterless function
884 -- call if this is not a limited type (where this is useful).
887 if Warn_On_Object_Renames_Function
888 and then No (Parameter_Associations (Nam))
889 and then not Is_Limited_Type (Etype (Nam))
890 and then Comes_From_Source (Nam)
893 ("?renaming function result object is suspicious", Nam);
895 ("\?function & will be called only once", Nam,
896 Entity (Name (Nam)));
898 ("\?suggest using an initialized constant object instead",
902 -- If the function call returns an unconstrained type, we must
903 -- build a constrained subtype for the new entity, in a way
904 -- similar to what is done for an object declaration with an
905 -- unconstrained nominal type.
907 if Is_Composite_Type (Etype (Nam))
908 and then not Is_Constrained (Etype (Nam))
909 and then not Has_Unknown_Discriminants (Etype (Nam))
910 and then Expander_Active
913 Loc : constant Source_Ptr := Sloc (N);
914 Subt : constant Entity_Id :=
915 Make_Defining_Identifier (Loc,
916 Chars => New_Internal_Name ('T'));
918 Remove_Side_Effects (Nam);
920 Make_Subtype_Declaration (Loc,
921 Defining_Identifier => Subt,
922 Subtype_Indication =>
923 Make_Subtype_From_Expr (Nam, Etype (Nam))));
924 Rewrite (Subtype_Mark (N), New_Occurrence_Of (Subt, Loc));
925 Set_Etype (Nam, Subt);
931 -- An object renaming requires an exact match of the type. Class-wide
932 -- matching is not allowed.
934 if Is_Class_Wide_Type (T)
935 and then Base_Type (Etype (Nam)) /= Base_Type (T)
942 -- (Ada 2005: AI-326): Handle wrong use of incomplete type
944 if Nkind (Nam) = N_Explicit_Dereference
945 and then Ekind (Etype (T2)) = E_Incomplete_Type
947 Error_Msg_NE ("invalid use of incomplete type&", Id, T2);
950 elsif Ekind (Etype (T)) = E_Incomplete_Type then
951 Error_Msg_NE ("invalid use of incomplete type&", Id, T);
957 if Ada_Version >= Ada_05
958 and then Nkind (Nam) = N_Attribute_Reference
959 and then Attribute_Name (Nam) = Name_Priority
963 elsif Ada_Version >= Ada_05
964 and then Nkind (Nam) in N_Has_Entity
971 if Nkind (Nam) = N_Attribute_Reference then
972 Nam_Ent := Entity (Prefix (Nam));
974 Nam_Ent := Entity (Nam);
977 Nam_Decl := Parent (Nam_Ent);
979 if Has_Null_Exclusion (N)
980 and then not Has_Null_Exclusion (Nam_Decl)
982 -- Ada 2005 (AI-423): If the object name denotes a generic
983 -- formal object of a generic unit G, and the object renaming
984 -- declaration occurs within the body of G or within the body
985 -- of a generic unit declared within the declarative region
986 -- of G, then the declaration of the formal object of G must
987 -- have a null exclusion or a null-excluding subtype.
989 if Is_Formal_Object (Nam_Ent)
990 and then In_Generic_Scope (Id)
992 if not Can_Never_Be_Null (Etype (Nam_Ent)) then
994 ("renamed formal does not exclude `NULL` "
995 & "(RM 8.5.1(4.6/2))", N);
997 elsif In_Package_Body (Scope (Id)) then
999 ("formal object does not have a null exclusion"
1000 & "(RM 8.5.1(4.6/2))", N);
1003 -- Ada 2005 (AI-423): Otherwise, the subtype of the object name
1004 -- shall exclude null.
1006 elsif not Can_Never_Be_Null (Etype (Nam_Ent)) then
1008 ("renamed object does not exclude `NULL` "
1009 & "(RM 8.5.1(4.6/2))", N);
1011 -- An instance is illegal if it contains a renaming that
1012 -- excludes null, and the actual does not. The renaming
1013 -- declaration has already indicated that the declaration
1014 -- of the renamed actual in the instance will raise
1015 -- constraint_error.
1017 elsif Nkind (Nam_Decl) = N_Object_Declaration
1018 and then In_Instance
1020 (Corresponding_Generic_Association (Nam_Decl))
1021 and then Nkind (Expression (Nam_Decl))
1022 = N_Raise_Constraint_Error
1025 ("renamed actual does not exclude `NULL` "
1026 & "(RM 8.5.1(4.6/2))", N);
1028 -- Finally, if there is a null exclusion, the subtype mark
1029 -- must not be null-excluding.
1031 elsif No (Access_Definition (N))
1032 and then Can_Never_Be_Null (T)
1035 ("`NOT NULL` not allowed (& already excludes null)",
1040 elsif Can_Never_Be_Null (T)
1041 and then not Can_Never_Be_Null (Etype (Nam_Ent))
1044 ("renamed object does not exclude `NULL` "
1045 & "(RM 8.5.1(4.6/2))", N);
1047 elsif Has_Null_Exclusion (N)
1048 and then No (Access_Definition (N))
1049 and then Can_Never_Be_Null (T)
1052 ("`NOT NULL` not allowed (& already excludes null)", N, T);
1057 Set_Ekind (Id, E_Variable);
1058 Init_Size_Align (Id);
1060 if T = Any_Type or else Etype (Nam) = Any_Type then
1063 -- Verify that the renamed entity is an object or a function call. It
1064 -- may have been rewritten in several ways.
1066 elsif Is_Object_Reference (Nam) then
1067 if Comes_From_Source (N)
1068 and then Is_Dependent_Component_Of_Mutable_Object (Nam)
1071 ("illegal renaming of discriminant-dependent component", Nam);
1074 -- A static function call may have been folded into a literal
1076 elsif Nkind (Original_Node (Nam)) = N_Function_Call
1078 -- When expansion is disabled, attribute reference is not
1079 -- rewritten as function call. Otherwise it may be rewritten
1080 -- as a conversion, so check original node.
1082 or else (Nkind (Original_Node (Nam)) = N_Attribute_Reference
1083 and then Is_Function_Attribute_Name
1084 (Attribute_Name (Original_Node (Nam))))
1086 -- Weird but legal, equivalent to renaming a function call.
1087 -- Illegal if the literal is the result of constant-folding an
1088 -- attribute reference that is not a function.
1090 or else (Is_Entity_Name (Nam)
1091 and then Ekind (Entity (Nam)) = E_Enumeration_Literal
1093 Nkind (Original_Node (Nam)) /= N_Attribute_Reference)
1095 or else (Nkind (Nam) = N_Type_Conversion
1096 and then Is_Tagged_Type (Entity (Subtype_Mark (Nam))))
1100 elsif Nkind (Nam) = N_Type_Conversion then
1102 ("renaming of conversion only allowed for tagged types", Nam);
1104 -- Ada 2005 (AI-327)
1106 elsif Ada_Version >= Ada_05
1107 and then Nkind (Nam) = N_Attribute_Reference
1108 and then Attribute_Name (Nam) = Name_Priority
1112 -- Allow internally generated x'Reference expression
1114 elsif Nkind (Nam) = N_Reference then
1118 Error_Msg_N ("expect object name in renaming", Nam);
1123 if not Is_Variable (Nam) then
1124 Set_Ekind (Id, E_Constant);
1125 Set_Never_Set_In_Source (Id, True);
1126 Set_Is_True_Constant (Id, True);
1129 Set_Renamed_Object (Id, Nam);
1130 end Analyze_Object_Renaming;
1132 ------------------------------
1133 -- Analyze_Package_Renaming --
1134 ------------------------------
1136 procedure Analyze_Package_Renaming (N : Node_Id) is
1137 New_P : constant Entity_Id := Defining_Entity (N);
1142 if Name (N) = Error then
1146 -- Apply Text_IO kludge here since we may be renaming a child of Text_IO
1148 Text_IO_Kludge (Name (N));
1150 if Current_Scope /= Standard_Standard then
1151 Set_Is_Pure (New_P, Is_Pure (Current_Scope));
1157 if Is_Entity_Name (Name (N)) then
1158 Old_P := Entity (Name (N));
1163 if Etype (Old_P) = Any_Type then
1164 Error_Msg_N ("expect package name in renaming", Name (N));
1166 elsif Ekind (Old_P) /= E_Package
1167 and then not (Ekind (Old_P) = E_Generic_Package
1168 and then In_Open_Scopes (Old_P))
1170 if Ekind (Old_P) = E_Generic_Package then
1172 ("generic package cannot be renamed as a package", Name (N));
1174 Error_Msg_Sloc := Sloc (Old_P);
1176 ("expect package name in renaming, found& declared#",
1180 -- Set basic attributes to minimize cascaded errors
1182 Set_Ekind (New_P, E_Package);
1183 Set_Etype (New_P, Standard_Void_Type);
1185 -- Here for OK package renaming
1188 -- Entities in the old package are accessible through the renaming
1189 -- entity. The simplest implementation is to have both packages share
1192 Set_Ekind (New_P, E_Package);
1193 Set_Etype (New_P, Standard_Void_Type);
1195 if Present (Renamed_Object (Old_P)) then
1196 Set_Renamed_Object (New_P, Renamed_Object (Old_P));
1198 Set_Renamed_Object (New_P, Old_P);
1201 Set_Has_Completion (New_P);
1203 Set_First_Entity (New_P, First_Entity (Old_P));
1204 Set_Last_Entity (New_P, Last_Entity (Old_P));
1205 Set_First_Private_Entity (New_P, First_Private_Entity (Old_P));
1206 Check_Library_Unit_Renaming (N, Old_P);
1207 Generate_Reference (Old_P, Name (N));
1209 -- If the renaming is in the visible part of a package, then we set
1210 -- Renamed_In_Spec for the renamed package, to prevent giving
1211 -- warnings about no entities referenced. Such a warning would be
1212 -- overenthusiastic, since clients can see entities in the renamed
1213 -- package via the visible package renaming.
1216 Ent : constant Entity_Id := Cunit_Entity (Current_Sem_Unit);
1218 if Ekind (Ent) = E_Package
1219 and then not In_Private_Part (Ent)
1220 and then In_Extended_Main_Source_Unit (N)
1221 and then Ekind (Old_P) = E_Package
1223 Set_Renamed_In_Spec (Old_P);
1227 -- If this is the renaming declaration of a package instantiation
1228 -- within itself, it is the declaration that ends the list of actuals
1229 -- for the instantiation. At this point, the subtypes that rename
1230 -- the actuals are flagged as generic, to avoid spurious ambiguities
1231 -- if the actuals for two distinct formals happen to coincide. If
1232 -- the actual is a private type, the subtype has a private completion
1233 -- that is flagged in the same fashion.
1235 -- Resolution is identical to what is was in the original generic.
1236 -- On exit from the generic instance, these are turned into regular
1237 -- subtypes again, so they are compatible with types in their class.
1239 if not Is_Generic_Instance (Old_P) then
1242 Spec := Specification (Unit_Declaration_Node (Old_P));
1245 if Nkind (Spec) = N_Package_Specification
1246 and then Present (Generic_Parent (Spec))
1247 and then Old_P = Current_Scope
1248 and then Chars (New_P) = Chars (Generic_Parent (Spec))
1254 E := First_Entity (Old_P);
1259 and then Nkind (Parent (E)) = N_Subtype_Declaration
1261 Set_Is_Generic_Actual_Type (E);
1263 if Is_Private_Type (E)
1264 and then Present (Full_View (E))
1266 Set_Is_Generic_Actual_Type (Full_View (E));
1275 end Analyze_Package_Renaming;
1277 -------------------------------
1278 -- Analyze_Renamed_Character --
1279 -------------------------------
1281 procedure Analyze_Renamed_Character
1286 C : constant Node_Id := Name (N);
1289 if Ekind (New_S) = E_Function then
1290 Resolve (C, Etype (New_S));
1293 Check_Frozen_Renaming (N, New_S);
1297 Error_Msg_N ("character literal can only be renamed as function", N);
1299 end Analyze_Renamed_Character;
1301 ---------------------------------
1302 -- Analyze_Renamed_Dereference --
1303 ---------------------------------
1305 procedure Analyze_Renamed_Dereference
1310 Nam : constant Node_Id := Name (N);
1311 P : constant Node_Id := Prefix (Nam);
1317 if not Is_Overloaded (P) then
1318 if Ekind (Etype (Nam)) /= E_Subprogram_Type
1319 or else not Type_Conformant (Etype (Nam), New_S) then
1320 Error_Msg_N ("designated type does not match specification", P);
1329 Get_First_Interp (Nam, Ind, It);
1331 while Present (It.Nam) loop
1333 if Ekind (It.Nam) = E_Subprogram_Type
1334 and then Type_Conformant (It.Nam, New_S) then
1336 if Typ /= Any_Id then
1337 Error_Msg_N ("ambiguous renaming", P);
1344 Get_Next_Interp (Ind, It);
1347 if Typ = Any_Type then
1348 Error_Msg_N ("designated type does not match specification", P);
1353 Check_Frozen_Renaming (N, New_S);
1357 end Analyze_Renamed_Dereference;
1359 ---------------------------
1360 -- Analyze_Renamed_Entry --
1361 ---------------------------
1363 procedure Analyze_Renamed_Entry
1368 Nam : constant Node_Id := Name (N);
1369 Sel : constant Node_Id := Selector_Name (Nam);
1373 if Entity (Sel) = Any_Id then
1375 -- Selector is undefined on prefix. Error emitted already
1377 Set_Has_Completion (New_S);
1381 -- Otherwise find renamed entity and build body of New_S as a call to it
1383 Old_S := Find_Renamed_Entity (N, Selector_Name (Nam), New_S);
1385 if Old_S = Any_Id then
1386 Error_Msg_N (" no subprogram or entry matches specification", N);
1389 Check_Subtype_Conformant (New_S, Old_S, N);
1390 Generate_Reference (New_S, Defining_Entity (N), 'b');
1391 Style.Check_Identifier (Defining_Entity (N), New_S);
1394 -- Only mode conformance required for a renaming_as_declaration
1396 Check_Mode_Conformant (New_S, Old_S, N);
1399 Inherit_Renamed_Profile (New_S, Old_S);
1401 -- The prefix can be an arbitrary expression that yields a task type,
1402 -- so it must be resolved.
1404 Resolve (Prefix (Nam), Scope (Old_S));
1407 Set_Convention (New_S, Convention (Old_S));
1408 Set_Has_Completion (New_S, Inside_A_Generic);
1411 Check_Frozen_Renaming (N, New_S);
1413 end Analyze_Renamed_Entry;
1415 -----------------------------------
1416 -- Analyze_Renamed_Family_Member --
1417 -----------------------------------
1419 procedure Analyze_Renamed_Family_Member
1424 Nam : constant Node_Id := Name (N);
1425 P : constant Node_Id := Prefix (Nam);
1429 if (Is_Entity_Name (P) and then Ekind (Entity (P)) = E_Entry_Family)
1430 or else (Nkind (P) = N_Selected_Component
1432 Ekind (Entity (Selector_Name (P))) = E_Entry_Family)
1434 if Is_Entity_Name (P) then
1435 Old_S := Entity (P);
1437 Old_S := Entity (Selector_Name (P));
1440 if not Entity_Matches_Spec (Old_S, New_S) then
1441 Error_Msg_N ("entry family does not match specification", N);
1444 Check_Subtype_Conformant (New_S, Old_S, N);
1445 Generate_Reference (New_S, Defining_Entity (N), 'b');
1446 Style.Check_Identifier (Defining_Entity (N), New_S);
1450 Error_Msg_N ("no entry family matches specification", N);
1453 Set_Has_Completion (New_S, Inside_A_Generic);
1456 Check_Frozen_Renaming (N, New_S);
1458 end Analyze_Renamed_Family_Member;
1460 -----------------------------------------
1461 -- Analyze_Renamed_Primitive_Operation --
1462 -----------------------------------------
1464 procedure Analyze_Renamed_Primitive_Operation
1473 Ctyp : Conformance_Type) return Boolean;
1474 -- Verify that the signatures of the renamed entity and the new entity
1475 -- match. The first formal of the renamed entity is skipped because it
1476 -- is the target object in any subsequent call.
1480 Ctyp : Conformance_Type) return Boolean
1486 if Ekind (Subp) /= Ekind (New_S) then
1490 Old_F := Next_Formal (First_Formal (Subp));
1491 New_F := First_Formal (New_S);
1492 while Present (Old_F) and then Present (New_F) loop
1493 if not Conforming_Types (Etype (Old_F), Etype (New_F), Ctyp) then
1497 if Ctyp >= Mode_Conformant
1498 and then Ekind (Old_F) /= Ekind (New_F)
1503 Next_Formal (New_F);
1504 Next_Formal (Old_F);
1511 if not Is_Overloaded (Selector_Name (Name (N))) then
1512 Old_S := Entity (Selector_Name (Name (N)));
1514 if not Conforms (Old_S, Type_Conformant) then
1519 -- Find the operation that matches the given signature
1527 Get_First_Interp (Selector_Name (Name (N)), Ind, It);
1529 while Present (It.Nam) loop
1530 if Conforms (It.Nam, Type_Conformant) then
1534 Get_Next_Interp (Ind, It);
1539 if Old_S = Any_Id then
1540 Error_Msg_N (" no subprogram or entry matches specification", N);
1544 if not Conforms (Old_S, Subtype_Conformant) then
1545 Error_Msg_N ("subtype conformance error in renaming", N);
1548 Generate_Reference (New_S, Defining_Entity (N), 'b');
1549 Style.Check_Identifier (Defining_Entity (N), New_S);
1552 -- Only mode conformance required for a renaming_as_declaration
1554 if not Conforms (Old_S, Mode_Conformant) then
1555 Error_Msg_N ("mode conformance error in renaming", N);
1559 -- Inherit_Renamed_Profile (New_S, Old_S);
1561 -- The prefix can be an arbitrary expression that yields an
1562 -- object, so it must be resolved.
1564 Resolve (Prefix (Name (N)));
1566 end Analyze_Renamed_Primitive_Operation;
1568 ---------------------------------
1569 -- Analyze_Subprogram_Renaming --
1570 ---------------------------------
1572 procedure Analyze_Subprogram_Renaming (N : Node_Id) is
1573 Formal_Spec : constant Node_Id := Corresponding_Formal_Spec (N);
1574 Is_Actual : constant Boolean := Present (Formal_Spec);
1575 Inst_Node : Node_Id := Empty;
1576 Nam : constant Node_Id := Name (N);
1578 Old_S : Entity_Id := Empty;
1579 Rename_Spec : Entity_Id;
1580 Save_AV : constant Ada_Version_Type := Ada_Version;
1581 Save_AV_Exp : constant Ada_Version_Type := Ada_Version_Explicit;
1582 Spec : constant Node_Id := Specification (N);
1584 procedure Check_Null_Exclusion
1587 -- Ada 2005 (AI-423): Given renaming Ren of subprogram Sub, check the
1588 -- following AI rules:
1590 -- If Ren is a renaming of a formal subprogram and one of its
1591 -- parameters has a null exclusion, then the corresponding formal
1592 -- in Sub must also have one. Otherwise the subtype of the Sub's
1593 -- formal parameter must exclude null.
1595 -- If Ren is a renaming of a formal function and its return
1596 -- profile has a null exclusion, then Sub's return profile must
1597 -- have one. Otherwise the subtype of Sub's return profile must
1600 function Original_Subprogram (Subp : Entity_Id) return Entity_Id;
1601 -- Find renamed entity when the declaration is a renaming_as_body and
1602 -- the renamed entity may itself be a renaming_as_body. Used to enforce
1603 -- rule that a renaming_as_body is illegal if the declaration occurs
1604 -- before the subprogram it completes is frozen, and renaming indirectly
1605 -- renames the subprogram itself.(Defect Report 8652/0027).
1607 --------------------------
1608 -- Check_Null_Exclusion --
1609 --------------------------
1611 procedure Check_Null_Exclusion
1615 Ren_Formal : Entity_Id;
1616 Sub_Formal : Entity_Id;
1621 Ren_Formal := First_Formal (Ren);
1622 Sub_Formal := First_Formal (Sub);
1623 while Present (Ren_Formal)
1624 and then Present (Sub_Formal)
1626 if Has_Null_Exclusion (Parent (Ren_Formal))
1628 not (Has_Null_Exclusion (Parent (Sub_Formal))
1629 or else Can_Never_Be_Null (Etype (Sub_Formal)))
1632 ("`NOT NULL` required for parameter &",
1633 Parent (Sub_Formal), Sub_Formal);
1636 Next_Formal (Ren_Formal);
1637 Next_Formal (Sub_Formal);
1640 -- Return profile check
1642 if Nkind (Parent (Ren)) = N_Function_Specification
1643 and then Nkind (Parent (Sub)) = N_Function_Specification
1644 and then Has_Null_Exclusion (Parent (Ren))
1646 not (Has_Null_Exclusion (Parent (Sub))
1647 or else Can_Never_Be_Null (Etype (Sub)))
1650 ("return must specify `NOT NULL`",
1651 Result_Definition (Parent (Sub)));
1653 end Check_Null_Exclusion;
1655 -------------------------
1656 -- Original_Subprogram --
1657 -------------------------
1659 function Original_Subprogram (Subp : Entity_Id) return Entity_Id is
1660 Orig_Decl : Node_Id;
1661 Orig_Subp : Entity_Id;
1664 -- First case: renamed entity is itself a renaming
1666 if Present (Alias (Subp)) then
1667 return Alias (Subp);
1670 Nkind (Unit_Declaration_Node (Subp)) = N_Subprogram_Declaration
1672 (Corresponding_Body (Unit_Declaration_Node (Subp)))
1674 -- Check if renamed entity is a renaming_as_body
1677 Unit_Declaration_Node
1678 (Corresponding_Body (Unit_Declaration_Node (Subp)));
1680 if Nkind (Orig_Decl) = N_Subprogram_Renaming_Declaration then
1681 Orig_Subp := Entity (Name (Orig_Decl));
1683 if Orig_Subp = Rename_Spec then
1685 -- Circularity detected
1690 return (Original_Subprogram (Orig_Subp));
1698 end Original_Subprogram;
1700 -- Start of processing for Analyze_Subprogram_Renaming
1703 -- We must test for the attribute renaming case before the Analyze
1704 -- call because otherwise Sem_Attr will complain that the attribute
1705 -- is missing an argument when it is analyzed.
1707 if Nkind (Nam) = N_Attribute_Reference then
1709 -- In the case of an abstract formal subprogram association, rewrite
1710 -- an actual given by a stream attribute as the name of the
1711 -- corresponding stream primitive of the type.
1713 -- In a generic context the stream operations are not generated, and
1714 -- this must be treated as a normal attribute reference, to be
1715 -- expanded in subsequent instantiations.
1717 if Is_Actual and then Is_Abstract_Subprogram (Formal_Spec)
1718 and then Expander_Active
1721 Stream_Prim : Entity_Id;
1722 Prefix_Type : constant Entity_Id := Entity (Prefix (Nam));
1725 -- The class-wide forms of the stream attributes are not
1726 -- primitive dispatching operations (even though they
1727 -- internally dispatch to a stream attribute).
1729 if Is_Class_Wide_Type (Prefix_Type) then
1731 ("attribute must be a primitive dispatching operation",
1736 -- Retrieve the primitive subprogram associated with the
1737 -- attribute. This can only be a stream attribute, since those
1738 -- are the only ones that are dispatching (and the actual for
1739 -- an abstract formal subprogram must be dispatching
1743 case Attribute_Name (Nam) is
1746 Find_Prim_Op (Prefix_Type, TSS_Stream_Input);
1749 Find_Prim_Op (Prefix_Type, TSS_Stream_Output);
1752 Find_Prim_Op (Prefix_Type, TSS_Stream_Read);
1755 Find_Prim_Op (Prefix_Type, TSS_Stream_Write);
1758 ("attribute must be a primitive"
1759 & " dispatching operation", Nam);
1765 -- If no operation was found, and the type is limited,
1766 -- the user should have defined one.
1768 when Program_Error =>
1769 if Is_Limited_Type (Prefix_Type) then
1771 ("stream operation not defined for type&",
1775 -- Otherwise, compiler should have generated default
1782 -- Rewrite the attribute into the name of its corresponding
1783 -- primitive dispatching subprogram. We can then proceed with
1784 -- the usual processing for subprogram renamings.
1787 Prim_Name : constant Node_Id :=
1788 Make_Identifier (Sloc (Nam),
1789 Chars => Chars (Stream_Prim));
1791 Set_Entity (Prim_Name, Stream_Prim);
1792 Rewrite (Nam, Prim_Name);
1797 -- Normal processing for a renaming of an attribute
1800 Attribute_Renaming (N);
1805 -- Check whether this declaration corresponds to the instantiation
1806 -- of a formal subprogram.
1808 -- If this is an instantiation, the corresponding actual is frozen and
1809 -- error messages can be made more precise. If this is a default
1810 -- subprogram, the entity is already established in the generic, and is
1811 -- not retrieved by visibility. If it is a default with a box, the
1812 -- candidate interpretations, if any, have been collected when building
1813 -- the renaming declaration. If overloaded, the proper interpretation is
1814 -- determined in Find_Renamed_Entity. If the entity is an operator,
1815 -- Find_Renamed_Entity applies additional visibility checks.
1818 Inst_Node := Unit_Declaration_Node (Formal_Spec);
1820 if Is_Entity_Name (Nam)
1821 and then Present (Entity (Nam))
1822 and then not Comes_From_Source (Nam)
1823 and then not Is_Overloaded (Nam)
1825 Old_S := Entity (Nam);
1826 New_S := Analyze_Subprogram_Specification (Spec);
1830 if Ekind (Entity (Nam)) = E_Operator then
1834 if Box_Present (Inst_Node) then
1835 Old_S := Find_Renamed_Entity (N, Name (N), New_S, Is_Actual);
1837 -- If there is an immediately visible homonym of the operator
1838 -- and the declaration has a default, this is worth a warning
1839 -- because the user probably did not intend to get the pre-
1840 -- defined operator, visible in the generic declaration. To
1841 -- find if there is an intended candidate, analyze the renaming
1842 -- again in the current context.
1844 elsif Scope (Old_S) = Standard_Standard
1845 and then Present (Default_Name (Inst_Node))
1848 Decl : constant Node_Id := New_Copy_Tree (N);
1852 Set_Entity (Name (Decl), Empty);
1853 Analyze (Name (Decl));
1855 Find_Renamed_Entity (Decl, Name (Decl), New_S, True);
1858 and then In_Open_Scopes (Scope (Hidden))
1859 and then Is_Immediately_Visible (Hidden)
1860 and then Comes_From_Source (Hidden)
1861 and then Hidden /= Old_S
1863 Error_Msg_Sloc := Sloc (Hidden);
1864 Error_Msg_N ("?default subprogram is resolved " &
1865 "in the generic declaration " &
1866 "(RM 12.6(17))", N);
1867 Error_Msg_NE ("\?and will not use & #", N, Hidden);
1875 New_S := Analyze_Subprogram_Specification (Spec);
1879 -- Renamed entity must be analyzed first, to avoid being hidden by
1880 -- new name (which might be the same in a generic instance).
1884 -- The renaming defines a new overloaded entity, which is analyzed
1885 -- like a subprogram declaration.
1887 New_S := Analyze_Subprogram_Specification (Spec);
1890 if Current_Scope /= Standard_Standard then
1891 Set_Is_Pure (New_S, Is_Pure (Current_Scope));
1894 Rename_Spec := Find_Corresponding_Spec (N);
1896 -- Case of Renaming_As_Body
1898 if Present (Rename_Spec) then
1900 -- Renaming declaration is the completion of the declaration of
1901 -- Rename_Spec. We build an actual body for it at the freezing point.
1903 Set_Corresponding_Spec (N, Rename_Spec);
1905 -- Deal with special case of stream functions of abstract types
1908 if Nkind (Unit_Declaration_Node (Rename_Spec)) =
1909 N_Abstract_Subprogram_Declaration
1911 -- Input stream functions are abstract if the object type is
1912 -- abstract. Similarly, all default stream functions for an
1913 -- interface type are abstract. However, these subprograms may
1914 -- receive explicit declarations in representation clauses, making
1915 -- the attribute subprograms usable as defaults in subsequent
1917 -- In this case we rewrite the declaration to make the subprogram
1918 -- non-abstract. We remove the previous declaration, and insert
1919 -- the new one at the point of the renaming, to prevent premature
1920 -- access to unfrozen types. The new declaration reuses the
1921 -- specification of the previous one, and must not be analyzed.
1924 (Is_Primitive (Entity (Nam))
1926 Is_Abstract_Type (Find_Dispatching_Type (Entity (Nam))));
1928 Old_Decl : constant Node_Id :=
1929 Unit_Declaration_Node (Rename_Spec);
1930 New_Decl : constant Node_Id :=
1931 Make_Subprogram_Declaration (Sloc (N),
1933 Relocate_Node (Specification (Old_Decl)));
1936 Insert_After (N, New_Decl);
1937 Set_Is_Abstract_Subprogram (Rename_Spec, False);
1938 Set_Analyzed (New_Decl);
1942 Set_Corresponding_Body (Unit_Declaration_Node (Rename_Spec), New_S);
1944 if Ada_Version = Ada_83 and then Comes_From_Source (N) then
1945 Error_Msg_N ("(Ada 83) renaming cannot serve as a body", N);
1948 Set_Convention (New_S, Convention (Rename_Spec));
1949 Check_Fully_Conformant (New_S, Rename_Spec);
1950 Set_Public_Status (New_S);
1952 -- The specification does not introduce new formals, but only
1953 -- repeats the formals of the original subprogram declaration.
1954 -- For cross-reference purposes, and for refactoring tools, we
1955 -- treat the formals of the renaming declaration as body formals.
1957 Reference_Body_Formals (Rename_Spec, New_S);
1959 -- Indicate that the entity in the declaration functions like the
1960 -- corresponding body, and is not a new entity. The body will be
1961 -- constructed later at the freeze point, so indicate that the
1962 -- completion has not been seen yet.
1964 Set_Ekind (New_S, E_Subprogram_Body);
1965 New_S := Rename_Spec;
1966 Set_Has_Completion (Rename_Spec, False);
1968 -- Ada 2005: check overriding indicator
1970 if Is_Overriding_Operation (Rename_Spec) then
1971 if Must_Not_Override (Specification (N)) then
1973 ("subprogram& overrides inherited operation",
1976 Style_Check and then not Must_Override (Specification (N))
1978 Style.Missing_Overriding (N, Rename_Spec);
1981 elsif Must_Override (Specification (N)) then
1982 Error_Msg_NE ("subprogram& is not overriding", N, Rename_Spec);
1985 -- Normal subprogram renaming (not renaming as body)
1988 Generate_Definition (New_S);
1989 New_Overloaded_Entity (New_S);
1991 if Is_Entity_Name (Nam)
1992 and then Is_Intrinsic_Subprogram (Entity (Nam))
1996 Check_Delayed_Subprogram (New_S);
2000 -- There is no need for elaboration checks on the new entity, which may
2001 -- be called before the next freezing point where the body will appear.
2002 -- Elaboration checks refer to the real entity, not the one created by
2003 -- the renaming declaration.
2005 Set_Kill_Elaboration_Checks (New_S, True);
2007 if Etype (Nam) = Any_Type then
2008 Set_Has_Completion (New_S);
2011 elsif Nkind (Nam) = N_Selected_Component then
2013 -- A prefix of the form A.B can designate an entry of task A, a
2014 -- protected operation of protected object A, or finally a primitive
2015 -- operation of object A. In the later case, A is an object of some
2016 -- tagged type, or an access type that denotes one such. To further
2017 -- distinguish these cases, note that the scope of a task entry or
2018 -- protected operation is type of the prefix.
2020 -- The prefix could be an overloaded function call that returns both
2021 -- kinds of operations. This overloading pathology is left to the
2022 -- dedicated reader ???
2025 T : constant Entity_Id := Etype (Prefix (Nam));
2034 Is_Tagged_Type (Designated_Type (T))))
2035 and then Scope (Entity (Selector_Name (Nam))) /= T
2037 Analyze_Renamed_Primitive_Operation
2038 (N, New_S, Present (Rename_Spec));
2042 -- Renamed entity is an entry or protected operation. For those
2043 -- cases an explicit body is built (at the point of freezing of
2044 -- this entity) that contains a call to the renamed entity.
2046 -- This is not allowed for renaming as body if the renamed
2047 -- spec is already frozen (see RM 8.5.4(5) for details).
2049 if Present (Rename_Spec)
2050 and then Is_Frozen (Rename_Spec)
2053 ("renaming-as-body cannot rename entry as subprogram", N);
2055 ("\since & is already frozen (RM 8.5.4(5))",
2058 Analyze_Renamed_Entry (N, New_S, Present (Rename_Spec));
2065 elsif Nkind (Nam) = N_Explicit_Dereference then
2067 -- Renamed entity is designated by access_to_subprogram expression.
2068 -- Must build body to encapsulate call, as in the entry case.
2070 Analyze_Renamed_Dereference (N, New_S, Present (Rename_Spec));
2073 elsif Nkind (Nam) = N_Indexed_Component then
2074 Analyze_Renamed_Family_Member (N, New_S, Present (Rename_Spec));
2077 elsif Nkind (Nam) = N_Character_Literal then
2078 Analyze_Renamed_Character (N, New_S, Present (Rename_Spec));
2081 elsif (not Is_Entity_Name (Nam)
2082 and then Nkind (Nam) /= N_Operator_Symbol)
2083 or else not Is_Overloadable (Entity (Nam))
2085 Error_Msg_N ("expect valid subprogram name in renaming", N);
2089 -- Find the renamed entity that matches the given specification. Disable
2090 -- Ada_83 because there is no requirement of full conformance between
2091 -- renamed entity and new entity, even though the same circuit is used.
2093 -- This is a bit of a kludge, which introduces a really irregular use of
2094 -- Ada_Version[_Explicit]. Would be nice to find cleaner way to do this
2097 Ada_Version := Ada_Version_Type'Max (Ada_Version, Ada_95);
2098 Ada_Version_Explicit := Ada_Version;
2101 Old_S := Find_Renamed_Entity (N, Name (N), New_S, Is_Actual);
2103 -- When the renamed subprogram is overloaded and used as an actual
2104 -- of a generic, its entity is set to the first available homonym.
2105 -- We must first disambiguate the name, then set the proper entity.
2108 and then Is_Overloaded (Nam)
2110 Set_Entity (Nam, Old_S);
2114 -- Most common case: subprogram renames subprogram. No body is generated
2115 -- in this case, so we must indicate the declaration is complete as is.
2116 -- and inherit various attributes of the renamed subprogram.
2118 if No (Rename_Spec) then
2119 Set_Has_Completion (New_S);
2120 Set_Is_Imported (New_S, Is_Imported (Entity (Nam)));
2121 Set_Is_Pure (New_S, Is_Pure (Entity (Nam)));
2122 Set_Is_Preelaborated (New_S, Is_Preelaborated (Entity (Nam)));
2124 -- Ada 2005 (AI-423): Check the consistency of null exclusions
2125 -- between a subprogram and its correct renaming.
2127 -- Note: the Any_Id check is a guard that prevents compiler crashes
2128 -- when performing a null exclusion check between a renaming and a
2129 -- renamed subprogram that has been found to be illegal.
2131 if Ada_Version >= Ada_05
2132 and then Entity (Nam) /= Any_Id
2134 Check_Null_Exclusion
2136 Sub => Entity (Nam));
2139 -- Enforce the Ada 2005 rule that the renamed entity cannot require
2140 -- overriding. The flag Requires_Overriding is set very selectively
2141 -- and misses some other illegal cases. The additional conditions
2142 -- checked below are sufficient but not necessary ???
2144 -- The rule does not apply to the renaming generated for an actual
2145 -- subprogram in an instance.
2150 -- Guard against previous errors, and omit renamings of predefined
2153 elsif Ekind (Old_S) /= E_Function
2154 and then Ekind (Old_S) /= E_Procedure
2158 elsif Requires_Overriding (Old_S)
2160 (Is_Abstract_Subprogram (Old_S)
2161 and then Present (Find_Dispatching_Type (Old_S))
2163 not Is_Abstract_Type (Find_Dispatching_Type (Old_S)))
2166 ("renamed entity cannot be "
2167 & "subprogram that requires overriding (RM 8.5.4 (5.1))", N);
2171 if Old_S /= Any_Id then
2173 and then From_Default (N)
2175 -- This is an implicit reference to the default actual
2177 Generate_Reference (Old_S, Nam, Typ => 'i', Force => True);
2179 Generate_Reference (Old_S, Nam);
2182 -- For a renaming-as-body, require subtype conformance, but if the
2183 -- declaration being completed has not been frozen, then inherit the
2184 -- convention of the renamed subprogram prior to checking conformance
2185 -- (unless the renaming has an explicit convention established; the
2186 -- rule stated in the RM doesn't seem to address this ???).
2188 if Present (Rename_Spec) then
2189 Generate_Reference (Rename_Spec, Defining_Entity (Spec), 'b');
2190 Style.Check_Identifier (Defining_Entity (Spec), Rename_Spec);
2192 if not Is_Frozen (Rename_Spec) then
2193 if not Has_Convention_Pragma (Rename_Spec) then
2194 Set_Convention (New_S, Convention (Old_S));
2197 if Ekind (Old_S) /= E_Operator then
2198 Check_Mode_Conformant (New_S, Old_S, Spec);
2201 if Original_Subprogram (Old_S) = Rename_Spec then
2202 Error_Msg_N ("unfrozen subprogram cannot rename itself ", N);
2205 Check_Subtype_Conformant (New_S, Old_S, Spec);
2208 Check_Frozen_Renaming (N, Rename_Spec);
2210 -- Check explicitly that renamed entity is not intrinsic, because
2211 -- in a generic the renamed body is not built. In this case,
2212 -- the renaming_as_body is a completion.
2214 if Inside_A_Generic then
2215 if Is_Frozen (Rename_Spec)
2216 and then Is_Intrinsic_Subprogram (Old_S)
2219 ("subprogram in renaming_as_body cannot be intrinsic",
2223 Set_Has_Completion (Rename_Spec);
2226 elsif Ekind (Old_S) /= E_Operator then
2227 Check_Mode_Conformant (New_S, Old_S);
2230 and then Error_Posted (New_S)
2232 Error_Msg_NE ("invalid actual subprogram: & #!", N, Old_S);
2236 if No (Rename_Spec) then
2238 -- The parameter profile of the new entity is that of the renamed
2239 -- entity: the subtypes given in the specification are irrelevant.
2241 Inherit_Renamed_Profile (New_S, Old_S);
2243 -- A call to the subprogram is transformed into a call to the
2244 -- renamed entity. This is transitive if the renamed entity is
2245 -- itself a renaming.
2247 if Present (Alias (Old_S)) then
2248 Set_Alias (New_S, Alias (Old_S));
2250 Set_Alias (New_S, Old_S);
2253 -- Note that we do not set Is_Intrinsic_Subprogram if we have a
2254 -- renaming as body, since the entity in this case is not an
2255 -- intrinsic (it calls an intrinsic, but we have a real body for
2256 -- this call, and it is in this body that the required intrinsic
2257 -- processing will take place).
2259 -- Also, if this is a renaming of inequality, the renamed operator
2260 -- is intrinsic, but what matters is the corresponding equality
2261 -- operator, which may be user-defined.
2263 Set_Is_Intrinsic_Subprogram
2265 Is_Intrinsic_Subprogram (Old_S)
2267 (Chars (Old_S) /= Name_Op_Ne
2268 or else Ekind (Old_S) = E_Operator
2270 Is_Intrinsic_Subprogram
2271 (Corresponding_Equality (Old_S))));
2273 if Ekind (Alias (New_S)) = E_Operator then
2274 Set_Has_Delayed_Freeze (New_S, False);
2277 -- If the renaming corresponds to an association for an abstract
2278 -- formal subprogram, then various attributes must be set to
2279 -- indicate that the renaming is an abstract dispatching operation
2280 -- with a controlling type.
2282 if Is_Actual and then Is_Abstract_Subprogram (Formal_Spec) then
2284 -- Mark the renaming as abstract here, so Find_Dispatching_Type
2285 -- see it as corresponding to a generic association for a
2286 -- formal abstract subprogram
2288 Set_Is_Abstract_Subprogram (New_S);
2291 New_S_Ctrl_Type : constant Entity_Id :=
2292 Find_Dispatching_Type (New_S);
2293 Old_S_Ctrl_Type : constant Entity_Id :=
2294 Find_Dispatching_Type (Old_S);
2297 if Old_S_Ctrl_Type /= New_S_Ctrl_Type then
2299 ("actual must be dispatching subprogram for type&",
2300 Nam, New_S_Ctrl_Type);
2303 Set_Is_Dispatching_Operation (New_S);
2304 Check_Controlling_Formals (New_S_Ctrl_Type, New_S);
2306 -- If the actual in the formal subprogram is itself a
2307 -- formal abstract subprogram association, there's no
2308 -- dispatch table component or position to inherit.
2310 if Present (DTC_Entity (Old_S)) then
2311 Set_DTC_Entity (New_S, DTC_Entity (Old_S));
2312 Set_DT_Position (New_S, DT_Position (Old_S));
2320 and then (Old_S = New_S
2321 or else (Nkind (Nam) /= N_Expanded_Name
2322 and then Chars (Old_S) = Chars (New_S)))
2324 Error_Msg_N ("subprogram cannot rename itself", N);
2327 Set_Convention (New_S, Convention (Old_S));
2329 if Is_Abstract_Subprogram (Old_S) then
2330 if Present (Rename_Spec) then
2332 ("a renaming-as-body cannot rename an abstract subprogram",
2334 Set_Has_Completion (Rename_Spec);
2336 Set_Is_Abstract_Subprogram (New_S);
2340 Check_Library_Unit_Renaming (N, Old_S);
2342 -- Pathological case: procedure renames entry in the scope of its
2343 -- task. Entry is given by simple name, but body must be built for
2344 -- procedure. Of course if called it will deadlock.
2346 if Ekind (Old_S) = E_Entry then
2347 Set_Has_Completion (New_S, False);
2348 Set_Alias (New_S, Empty);
2352 Freeze_Before (N, Old_S);
2353 Set_Has_Delayed_Freeze (New_S, False);
2354 Freeze_Before (N, New_S);
2356 -- An abstract subprogram is only allowed as an actual in the case
2357 -- where the formal subprogram is also abstract.
2359 if (Ekind (Old_S) = E_Procedure or else Ekind (Old_S) = E_Function)
2360 and then Is_Abstract_Subprogram (Old_S)
2361 and then not Is_Abstract_Subprogram (Formal_Spec)
2364 ("abstract subprogram not allowed as generic actual", Nam);
2369 -- A common error is to assume that implicit operators for types are
2370 -- defined in Standard, or in the scope of a subtype. In those cases
2371 -- where the renamed entity is given with an expanded name, it is
2372 -- worth mentioning that operators for the type are not declared in
2373 -- the scope given by the prefix.
2375 if Nkind (Nam) = N_Expanded_Name
2376 and then Nkind (Selector_Name (Nam)) = N_Operator_Symbol
2377 and then Scope (Entity (Nam)) = Standard_Standard
2380 T : constant Entity_Id :=
2381 Base_Type (Etype (First_Formal (New_S)));
2383 Error_Msg_Node_2 := Prefix (Nam);
2385 ("operator for type& is not declared in&", Prefix (Nam), T);
2390 ("no visible subprogram matches the specification for&",
2394 if Present (Candidate_Renaming) then
2401 F1 := First_Formal (Candidate_Renaming);
2402 F2 := First_Formal (New_S);
2403 T1 := First_Subtype (Etype (F1));
2405 while Present (F1) and then Present (F2) loop
2410 if Present (F1) and then Present (Default_Value (F1)) then
2411 if Present (Next_Formal (F1)) then
2413 ("\missing specification for &" &
2414 " and other formals with defaults", Spec, F1);
2417 ("\missing specification for &", Spec, F1);
2421 if Nkind (Nam) = N_Operator_Symbol
2422 and then From_Default (N)
2424 Error_Msg_Node_2 := T1;
2426 ("default & on & is not directly visible",
2433 -- Ada 2005 AI 404: if the new subprogram is dispatching, verify that
2434 -- controlling access parameters are known non-null for the renamed
2435 -- subprogram. Test also applies to a subprogram instantiation that
2436 -- is dispatching. Test is skipped if some previous error was detected
2437 -- that set Old_S to Any_Id.
2439 if Ada_Version >= Ada_05
2440 and then Old_S /= Any_Id
2441 and then not Is_Dispatching_Operation (Old_S)
2442 and then Is_Dispatching_Operation (New_S)
2449 Old_F := First_Formal (Old_S);
2450 New_F := First_Formal (New_S);
2451 while Present (Old_F) loop
2452 if Ekind (Etype (Old_F)) = E_Anonymous_Access_Type
2453 and then Is_Controlling_Formal (New_F)
2454 and then not Can_Never_Be_Null (Old_F)
2456 Error_Msg_N ("access parameter is controlling,", New_F);
2458 ("\corresponding parameter of& "
2459 & "must be explicitly null excluding", New_F, Old_S);
2462 Next_Formal (Old_F);
2463 Next_Formal (New_F);
2468 -- A useful warning, suggested by Ada Bug Finder (Ada-Europe 2005)
2470 if Comes_From_Source (N)
2471 and then Present (Old_S)
2472 and then Nkind (Old_S) = N_Defining_Operator_Symbol
2473 and then Nkind (New_S) = N_Defining_Operator_Symbol
2474 and then Chars (Old_S) /= Chars (New_S)
2477 ("?& is being renamed as a different operator",
2481 -- Another warning or some utility: if the new subprogram as the same
2482 -- name as the old one, the old one is not hidden by an outer homograph,
2483 -- the new one is not a public symbol, and the old one is otherwise
2484 -- directly visible, the renaming is superfluous.
2486 if Chars (Old_S) = Chars (New_S)
2487 and then Comes_From_Source (N)
2488 and then Scope (Old_S) /= Standard_Standard
2489 and then Warn_On_Redundant_Constructs
2491 (Is_Immediately_Visible (Old_S)
2492 or else Is_Potentially_Use_Visible (Old_S))
2493 and then Is_Overloadable (Current_Scope)
2494 and then Chars (Current_Scope) /= Chars (Old_S)
2497 ("?redundant renaming, entity is directly visible", Name (N));
2500 Ada_Version := Save_AV;
2501 Ada_Version_Explicit := Save_AV_Exp;
2502 end Analyze_Subprogram_Renaming;
2504 -------------------------
2505 -- Analyze_Use_Package --
2506 -------------------------
2508 -- Resolve the package names in the use clause, and make all the visible
2509 -- entities defined in the package potentially use-visible. If the package
2510 -- is already in use from a previous use clause, its visible entities are
2511 -- already use-visible. In that case, mark the occurrence as a redundant
2512 -- use. If the package is an open scope, i.e. if the use clause occurs
2513 -- within the package itself, ignore it.
2515 procedure Analyze_Use_Package (N : Node_Id) is
2516 Pack_Name : Node_Id;
2519 -- Start of processing for Analyze_Use_Package
2522 Set_Hidden_By_Use_Clause (N, No_Elist);
2524 -- Use clause is not allowed in a spec of a predefined package
2525 -- declaration except that packages whose file name starts a-n are OK
2526 -- (these are children of Ada.Numerics, and such packages are never
2527 -- loaded by Rtsfind).
2529 if Is_Predefined_File_Name (Unit_File_Name (Current_Sem_Unit))
2530 and then Name_Buffer (1 .. 3) /= "a-n"
2532 Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Declaration
2534 Error_Msg_N ("use clause not allowed in predefined spec", N);
2537 -- Chain clause to list of use clauses in current scope
2539 if Nkind (Parent (N)) /= N_Compilation_Unit then
2540 Chain_Use_Clause (N);
2543 -- Loop through package names to identify referenced packages
2545 Pack_Name := First (Names (N));
2546 while Present (Pack_Name) loop
2547 Analyze (Pack_Name);
2549 if Nkind (Parent (N)) = N_Compilation_Unit
2550 and then Nkind (Pack_Name) = N_Expanded_Name
2556 Pref := Prefix (Pack_Name);
2557 while Nkind (Pref) = N_Expanded_Name loop
2558 Pref := Prefix (Pref);
2561 if Entity (Pref) = Standard_Standard then
2563 ("predefined package Standard cannot appear"
2564 & " in a context clause", Pref);
2572 -- Loop through package names to mark all entities as potentially
2575 Pack_Name := First (Names (N));
2576 while Present (Pack_Name) loop
2577 if Is_Entity_Name (Pack_Name) then
2578 Pack := Entity (Pack_Name);
2580 if Ekind (Pack) /= E_Package
2581 and then Etype (Pack) /= Any_Type
2583 if Ekind (Pack) = E_Generic_Package then
2585 ("a generic package is not allowed in a use clause",
2588 Error_Msg_N ("& is not a usable package", Pack_Name);
2592 if Nkind (Parent (N)) = N_Compilation_Unit then
2593 Check_In_Previous_With_Clause (N, Pack_Name);
2596 if Applicable_Use (Pack_Name) then
2597 Use_One_Package (Pack, N);
2601 -- Report error because name denotes something other than a package
2604 Error_Msg_N ("& is not a package", Pack_Name);
2609 end Analyze_Use_Package;
2611 ----------------------
2612 -- Analyze_Use_Type --
2613 ----------------------
2615 procedure Analyze_Use_Type (N : Node_Id) is
2620 Set_Hidden_By_Use_Clause (N, No_Elist);
2622 -- Chain clause to list of use clauses in current scope
2624 if Nkind (Parent (N)) /= N_Compilation_Unit then
2625 Chain_Use_Clause (N);
2628 Id := First (Subtype_Marks (N));
2629 while Present (Id) loop
2633 if E /= Any_Type then
2636 if Nkind (Parent (N)) = N_Compilation_Unit then
2637 if Nkind (Id) = N_Identifier then
2638 Error_Msg_N ("type is not directly visible", Id);
2640 elsif Is_Child_Unit (Scope (E))
2641 and then Scope (E) /= System_Aux_Id
2643 Check_In_Previous_With_Clause (N, Prefix (Id));
2648 -- If the use_type_clause appears in a compilation unit context,
2649 -- check whether it comes from a unit that may appear in a
2650 -- limited_with_clause, for a better error message.
2652 if Nkind (Parent (N)) = N_Compilation_Unit
2653 and then Nkind (Id) /= N_Identifier
2659 function Mentioned (Nam : Node_Id) return Boolean;
2660 -- Check whether the prefix of expanded name for the type
2661 -- appears in the prefix of some limited_with_clause.
2667 function Mentioned (Nam : Node_Id) return Boolean is
2669 return Nkind (Name (Item)) = N_Selected_Component
2671 Chars (Prefix (Name (Item))) = Chars (Nam);
2675 Pref := Prefix (Id);
2676 Item := First (Context_Items (Parent (N)));
2678 while Present (Item) and then Item /= N loop
2679 if Nkind (Item) = N_With_Clause
2680 and then Limited_Present (Item)
2681 and then Mentioned (Pref)
2684 (Get_Msg_Id, "premature usage of incomplete type");
2695 end Analyze_Use_Type;
2697 --------------------
2698 -- Applicable_Use --
2699 --------------------
2701 function Applicable_Use (Pack_Name : Node_Id) return Boolean is
2702 Pack : constant Entity_Id := Entity (Pack_Name);
2705 if In_Open_Scopes (Pack) then
2706 if Warn_On_Redundant_Constructs
2707 and then Pack = Current_Scope
2710 ("& is already use-visible within itself?", Pack_Name, Pack);
2715 elsif In_Use (Pack) then
2716 Note_Redundant_Use (Pack_Name);
2719 elsif Present (Renamed_Object (Pack))
2720 and then In_Use (Renamed_Object (Pack))
2722 Note_Redundant_Use (Pack_Name);
2730 ------------------------
2731 -- Attribute_Renaming --
2732 ------------------------
2734 procedure Attribute_Renaming (N : Node_Id) is
2735 Loc : constant Source_Ptr := Sloc (N);
2736 Nam : constant Node_Id := Name (N);
2737 Spec : constant Node_Id := Specification (N);
2738 New_S : constant Entity_Id := Defining_Unit_Name (Spec);
2739 Aname : constant Name_Id := Attribute_Name (Nam);
2741 Form_Num : Nat := 0;
2742 Expr_List : List_Id := No_List;
2744 Attr_Node : Node_Id;
2745 Body_Node : Node_Id;
2746 Param_Spec : Node_Id;
2749 Generate_Definition (New_S);
2751 -- This procedure is called in the context of subprogram renaming, and
2752 -- thus the attribute must be one that is a subprogram. All of those
2753 -- have at least one formal parameter, with the singular exception of
2754 -- AST_Entry (which is a real oddity, it is odd that this can be renamed
2757 if not Is_Non_Empty_List (Parameter_Specifications (Spec)) then
2758 if Aname /= Name_AST_Entry then
2760 ("subprogram renaming an attribute must have formals", N);
2765 Param_Spec := First (Parameter_Specifications (Spec));
2766 while Present (Param_Spec) loop
2767 Form_Num := Form_Num + 1;
2769 if Nkind (Parameter_Type (Param_Spec)) /= N_Access_Definition then
2770 Find_Type (Parameter_Type (Param_Spec));
2772 -- The profile of the new entity denotes the base type (s) of
2773 -- the types given in the specification. For access parameters
2774 -- there are no subtypes involved.
2776 Rewrite (Parameter_Type (Param_Spec),
2778 (Base_Type (Entity (Parameter_Type (Param_Spec))), Loc));
2781 if No (Expr_List) then
2782 Expr_List := New_List;
2785 Append_To (Expr_List,
2786 Make_Identifier (Loc,
2787 Chars => Chars (Defining_Identifier (Param_Spec))));
2789 -- The expressions in the attribute reference are not freeze
2790 -- points. Neither is the attribute as a whole, see below.
2792 Set_Must_Not_Freeze (Last (Expr_List));
2797 -- Immediate error if too many formals. Other mismatches in number or
2798 -- types of parameters are detected when we analyze the body of the
2799 -- subprogram that we construct.
2801 if Form_Num > 2 then
2802 Error_Msg_N ("too many formals for attribute", N);
2804 -- Error if the attribute reference has expressions that look like
2805 -- formal parameters.
2807 elsif Present (Expressions (Nam)) then
2808 Error_Msg_N ("illegal expressions in attribute reference", Nam);
2811 Aname = Name_Compose or else
2812 Aname = Name_Exponent or else
2813 Aname = Name_Leading_Part or else
2814 Aname = Name_Pos or else
2815 Aname = Name_Round or else
2816 Aname = Name_Scaling or else
2819 if Nkind (N) = N_Subprogram_Renaming_Declaration
2820 and then Present (Corresponding_Formal_Spec (N))
2823 ("generic actual cannot be attribute involving universal type",
2827 ("attribute involving a universal type cannot be renamed",
2832 -- AST_Entry is an odd case. It doesn't really make much sense to allow
2833 -- it to be renamed, but that's the DEC rule, so we have to do it right.
2834 -- The point is that the AST_Entry call should be made now, and what the
2835 -- function will return is the returned value.
2837 -- Note that there is no Expr_List in this case anyway
2839 if Aname = Name_AST_Entry then
2845 Ent := Make_Defining_Identifier (Loc, New_Internal_Name ('R'));
2848 Make_Object_Declaration (Loc,
2849 Defining_Identifier => Ent,
2850 Object_Definition =>
2851 New_Occurrence_Of (RTE (RE_AST_Handler), Loc),
2853 Constant_Present => True);
2855 Set_Assignment_OK (Decl, True);
2856 Insert_Action (N, Decl);
2857 Attr_Node := Make_Identifier (Loc, Chars (Ent));
2860 -- For all other attributes, we rewrite the attribute node to have
2861 -- a list of expressions corresponding to the subprogram formals.
2862 -- A renaming declaration is not a freeze point, and the analysis of
2863 -- the attribute reference should not freeze the type of the prefix.
2867 Make_Attribute_Reference (Loc,
2868 Prefix => Prefix (Nam),
2869 Attribute_Name => Aname,
2870 Expressions => Expr_List);
2872 Set_Must_Not_Freeze (Attr_Node);
2873 Set_Must_Not_Freeze (Prefix (Nam));
2876 -- Case of renaming a function
2878 if Nkind (Spec) = N_Function_Specification then
2879 if Is_Procedure_Attribute_Name (Aname) then
2880 Error_Msg_N ("attribute can only be renamed as procedure", Nam);
2884 Find_Type (Result_Definition (Spec));
2885 Rewrite (Result_Definition (Spec),
2887 Base_Type (Entity (Result_Definition (Spec))), Loc));
2890 Make_Subprogram_Body (Loc,
2891 Specification => Spec,
2892 Declarations => New_List,
2893 Handled_Statement_Sequence =>
2894 Make_Handled_Sequence_Of_Statements (Loc,
2895 Statements => New_List (
2896 Make_Simple_Return_Statement (Loc,
2897 Expression => Attr_Node))));
2899 -- Case of renaming a procedure
2902 if not Is_Procedure_Attribute_Name (Aname) then
2903 Error_Msg_N ("attribute can only be renamed as function", Nam);
2908 Make_Subprogram_Body (Loc,
2909 Specification => Spec,
2910 Declarations => New_List,
2911 Handled_Statement_Sequence =>
2912 Make_Handled_Sequence_Of_Statements (Loc,
2913 Statements => New_List (Attr_Node)));
2916 -- In case of tagged types we add the body of the generated function to
2917 -- the freezing actions of the type (because in the general case such
2918 -- type is still not frozen). We exclude from this processing generic
2919 -- formal subprograms found in instantiations and AST_Entry renamings.
2921 if not Present (Corresponding_Formal_Spec (N))
2922 and then Etype (Nam) /= RTE (RE_AST_Handler)
2925 P : constant Entity_Id := Prefix (Nam);
2930 if Is_Tagged_Type (Etype (P)) then
2931 Ensure_Freeze_Node (Etype (P));
2932 Append_Freeze_Action (Etype (P), Body_Node);
2934 Rewrite (N, Body_Node);
2936 Set_Etype (New_S, Base_Type (Etype (New_S)));
2940 -- Generic formal subprograms or AST_Handler renaming
2943 Rewrite (N, Body_Node);
2945 Set_Etype (New_S, Base_Type (Etype (New_S)));
2948 if Is_Compilation_Unit (New_S) then
2950 ("a library unit can only rename another library unit", N);
2953 -- We suppress elaboration warnings for the resulting entity, since
2954 -- clearly they are not needed, and more particularly, in the case
2955 -- of a generic formal subprogram, the resulting entity can appear
2956 -- after the instantiation itself, and thus look like a bogus case
2957 -- of access before elaboration.
2959 Set_Suppress_Elaboration_Warnings (New_S);
2961 end Attribute_Renaming;
2963 ----------------------
2964 -- Chain_Use_Clause --
2965 ----------------------
2967 procedure Chain_Use_Clause (N : Node_Id) is
2969 Level : Int := Scope_Stack.Last;
2972 if not Is_Compilation_Unit (Current_Scope)
2973 or else not Is_Child_Unit (Current_Scope)
2975 null; -- Common case
2977 elsif Defining_Entity (Parent (N)) = Current_Scope then
2978 null; -- Common case for compilation unit
2981 -- If declaration appears in some other scope, it must be in some
2982 -- parent unit when compiling a child.
2984 Pack := Defining_Entity (Parent (N));
2985 if not In_Open_Scopes (Pack) then
2986 null; -- default as well
2989 -- Find entry for parent unit in scope stack
2991 while Scope_Stack.Table (Level).Entity /= Pack loop
2997 Set_Next_Use_Clause (N,
2998 Scope_Stack.Table (Level).First_Use_Clause);
2999 Scope_Stack.Table (Level).First_Use_Clause := N;
3000 end Chain_Use_Clause;
3002 ---------------------------
3003 -- Check_Frozen_Renaming --
3004 ---------------------------
3006 procedure Check_Frozen_Renaming (N : Node_Id; Subp : Entity_Id) is
3012 and then not Has_Completion (Subp)
3016 (Parent (Declaration_Node (Subp)), Defining_Entity (N));
3018 if Is_Entity_Name (Name (N)) then
3019 Old_S := Entity (Name (N));
3021 if not Is_Frozen (Old_S)
3022 and then Operating_Mode /= Check_Semantics
3024 Append_Freeze_Action (Old_S, B_Node);
3026 Insert_After (N, B_Node);
3030 if Is_Intrinsic_Subprogram (Old_S)
3031 and then not In_Instance
3034 ("subprogram used in renaming_as_body cannot be intrinsic",
3039 Insert_After (N, B_Node);
3043 end Check_Frozen_Renaming;
3045 -----------------------------------
3046 -- Check_In_Previous_With_Clause --
3047 -----------------------------------
3049 procedure Check_In_Previous_With_Clause
3053 Pack : constant Entity_Id := Entity (Original_Node (Nam));
3058 Item := First (Context_Items (Parent (N)));
3060 while Present (Item)
3063 if Nkind (Item) = N_With_Clause
3065 -- Protect the frontend against previous critical errors
3067 and then Nkind (Name (Item)) /= N_Selected_Component
3068 and then Entity (Name (Item)) = Pack
3072 -- Find root library unit in with_clause
3074 while Nkind (Par) = N_Expanded_Name loop
3075 Par := Prefix (Par);
3078 if Is_Child_Unit (Entity (Original_Node (Par))) then
3080 ("& is not directly visible", Par, Entity (Par));
3089 -- On exit, package is not mentioned in a previous with_clause.
3090 -- Check if its prefix is.
3092 if Nkind (Nam) = N_Expanded_Name then
3093 Check_In_Previous_With_Clause (N, Prefix (Nam));
3095 elsif Pack /= Any_Id then
3096 Error_Msg_NE ("& is not visible", Nam, Pack);
3098 end Check_In_Previous_With_Clause;
3100 ---------------------------------
3101 -- Check_Library_Unit_Renaming --
3102 ---------------------------------
3104 procedure Check_Library_Unit_Renaming (N : Node_Id; Old_E : Entity_Id) is
3108 if Nkind (Parent (N)) /= N_Compilation_Unit then
3111 -- Check for library unit. Note that we used to check for the scope
3112 -- being Standard here, but that was wrong for Standard itself.
3114 elsif not Is_Compilation_Unit (Old_E)
3115 and then not Is_Child_Unit (Old_E)
3117 Error_Msg_N ("renamed unit must be a library unit", Name (N));
3119 -- Entities defined in Standard (operators and boolean literals) cannot
3120 -- be renamed as library units.
3122 elsif Scope (Old_E) = Standard_Standard
3123 and then Sloc (Old_E) = Standard_Location
3125 Error_Msg_N ("renamed unit must be a library unit", Name (N));
3127 elsif Present (Parent_Spec (N))
3128 and then Nkind (Unit (Parent_Spec (N))) = N_Generic_Package_Declaration
3129 and then not Is_Child_Unit (Old_E)
3132 ("renamed unit must be a child unit of generic parent", Name (N));
3134 elsif Nkind (N) in N_Generic_Renaming_Declaration
3135 and then Nkind (Name (N)) = N_Expanded_Name
3136 and then Is_Generic_Instance (Entity (Prefix (Name (N))))
3137 and then Is_Generic_Unit (Old_E)
3140 ("renamed generic unit must be a library unit", Name (N));
3142 elsif Is_Package_Or_Generic_Package (Old_E) then
3144 -- Inherit categorization flags
3146 New_E := Defining_Entity (N);
3147 Set_Is_Pure (New_E, Is_Pure (Old_E));
3148 Set_Is_Preelaborated (New_E, Is_Preelaborated (Old_E));
3149 Set_Is_Remote_Call_Interface (New_E,
3150 Is_Remote_Call_Interface (Old_E));
3151 Set_Is_Remote_Types (New_E, Is_Remote_Types (Old_E));
3152 Set_Is_Shared_Passive (New_E, Is_Shared_Passive (Old_E));
3154 end Check_Library_Unit_Renaming;
3160 procedure End_Scope is
3166 Id := First_Entity (Current_Scope);
3167 while Present (Id) loop
3168 -- An entity in the current scope is not necessarily the first one
3169 -- on its homonym chain. Find its predecessor if any,
3170 -- If it is an internal entity, it will not be in the visibility
3171 -- chain altogether, and there is nothing to unchain.
3173 if Id /= Current_Entity (Id) then
3174 Prev := Current_Entity (Id);
3175 while Present (Prev)
3176 and then Present (Homonym (Prev))
3177 and then Homonym (Prev) /= Id
3179 Prev := Homonym (Prev);
3182 -- Skip to end of loop if Id is not in the visibility chain
3184 if No (Prev) or else Homonym (Prev) /= Id then
3192 Set_Is_Immediately_Visible (Id, False);
3194 Outer := Homonym (Id);
3195 while Present (Outer) and then Scope (Outer) = Current_Scope loop
3196 Outer := Homonym (Outer);
3199 -- Reset homonym link of other entities, but do not modify link
3200 -- between entities in current scope, so that the back-end can have
3201 -- a proper count of local overloadings.
3204 Set_Name_Entity_Id (Chars (Id), Outer);
3206 elsif Scope (Prev) /= Scope (Id) then
3207 Set_Homonym (Prev, Outer);
3214 -- If the scope generated freeze actions, place them before the
3215 -- current declaration and analyze them. Type declarations and
3216 -- the bodies of initialization procedures can generate such nodes.
3217 -- We follow the parent chain until we reach a list node, which is
3218 -- the enclosing list of declarations. If the list appears within
3219 -- a protected definition, move freeze nodes outside the protected
3223 (Scope_Stack.Table (Scope_Stack.Last).Pending_Freeze_Actions)
3227 L : constant List_Id := Scope_Stack.Table
3228 (Scope_Stack.Last).Pending_Freeze_Actions;
3231 if Is_Itype (Current_Scope) then
3232 Decl := Associated_Node_For_Itype (Current_Scope);
3234 Decl := Parent (Current_Scope);
3239 while not (Is_List_Member (Decl))
3240 or else Nkind_In (Parent (Decl), N_Protected_Definition,
3243 Decl := Parent (Decl);
3246 Insert_List_Before_And_Analyze (Decl, L);
3255 ---------------------
3256 -- End_Use_Clauses --
3257 ---------------------
3259 procedure End_Use_Clauses (Clause : Node_Id) is
3263 -- Remove Use_Type clauses first, because they affect the
3264 -- visibility of operators in subsequent used packages.
3267 while Present (U) loop
3268 if Nkind (U) = N_Use_Type_Clause then
3272 Next_Use_Clause (U);
3276 while Present (U) loop
3277 if Nkind (U) = N_Use_Package_Clause then
3278 End_Use_Package (U);
3281 Next_Use_Clause (U);
3283 end End_Use_Clauses;
3285 ---------------------
3286 -- End_Use_Package --
3287 ---------------------
3289 procedure End_Use_Package (N : Node_Id) is
3290 Pack_Name : Node_Id;
3295 function Is_Primitive_Operator
3297 F : Entity_Id) return Boolean;
3298 -- Check whether Op is a primitive operator of a use-visible type
3300 ---------------------------
3301 -- Is_Primitive_Operator --
3302 ---------------------------
3304 function Is_Primitive_Operator
3306 F : Entity_Id) return Boolean
3308 T : constant Entity_Id := Etype (F);
3311 and then Scope (T) = Scope (Op);
3312 end Is_Primitive_Operator;
3314 -- Start of processing for End_Use_Package
3317 Pack_Name := First (Names (N));
3318 while Present (Pack_Name) loop
3320 -- Test that Pack_Name actually denotes a package before processing
3322 if Is_Entity_Name (Pack_Name)
3323 and then Ekind (Entity (Pack_Name)) = E_Package
3325 Pack := Entity (Pack_Name);
3327 if In_Open_Scopes (Pack) then
3330 elsif not Redundant_Use (Pack_Name) then
3331 Set_In_Use (Pack, False);
3332 Set_Current_Use_Clause (Pack, Empty);
3334 Id := First_Entity (Pack);
3335 while Present (Id) loop
3337 -- Preserve use-visibility of operators that are primitive
3338 -- operators of a type that is use-visible through an active
3341 if Nkind (Id) = N_Defining_Operator_Symbol
3343 (Is_Primitive_Operator (Id, First_Formal (Id))
3345 (Present (Next_Formal (First_Formal (Id)))
3347 Is_Primitive_Operator
3348 (Id, Next_Formal (First_Formal (Id)))))
3353 Set_Is_Potentially_Use_Visible (Id, False);
3356 if Is_Private_Type (Id)
3357 and then Present (Full_View (Id))
3359 Set_Is_Potentially_Use_Visible (Full_View (Id), False);
3365 if Present (Renamed_Object (Pack)) then
3366 Set_In_Use (Renamed_Object (Pack), False);
3367 Set_Current_Use_Clause (Renamed_Object (Pack), Empty);
3370 if Chars (Pack) = Name_System
3371 and then Scope (Pack) = Standard_Standard
3372 and then Present_System_Aux
3374 Id := First_Entity (System_Aux_Id);
3375 while Present (Id) loop
3376 Set_Is_Potentially_Use_Visible (Id, False);
3378 if Is_Private_Type (Id)
3379 and then Present (Full_View (Id))
3381 Set_Is_Potentially_Use_Visible (Full_View (Id), False);
3387 Set_In_Use (System_Aux_Id, False);
3391 Set_Redundant_Use (Pack_Name, False);
3398 if Present (Hidden_By_Use_Clause (N)) then
3399 Elmt := First_Elmt (Hidden_By_Use_Clause (N));
3400 while Present (Elmt) loop
3402 E : constant Entity_Id := Node (Elmt);
3405 -- Reset either Use_Visibility or Direct_Visibility, depending
3406 -- on how the entity was hidden by the use clause.
3408 if In_Use (Scope (E))
3409 and then Used_As_Generic_Actual (Scope (E))
3411 Set_Is_Potentially_Use_Visible (Node (Elmt));
3413 Set_Is_Immediately_Visible (Node (Elmt));
3420 Set_Hidden_By_Use_Clause (N, No_Elist);
3422 end End_Use_Package;
3428 procedure End_Use_Type (N : Node_Id) is
3435 Id := First (Subtype_Marks (N));
3436 while Present (Id) loop
3438 -- A call to rtsfind may occur while analyzing a use_type clause,
3439 -- in which case the type marks are not resolved yet, and there is
3440 -- nothing to remove.
3442 if not Is_Entity_Name (Id)
3443 or else No (Entity (Id))
3451 or else From_With_Type (T)
3455 -- Note that the use_Type clause may mention a subtype of the type
3456 -- whose primitive operations have been made visible. Here as
3457 -- elsewhere, it is the base type that matters for visibility.
3459 elsif In_Open_Scopes (Scope (Base_Type (T))) then
3462 elsif not Redundant_Use (Id) then
3463 Set_In_Use (T, False);
3464 Set_In_Use (Base_Type (T), False);
3465 Set_Current_Use_Clause (T, Empty);
3466 Set_Current_Use_Clause (Base_Type (T), Empty);
3467 Op_List := Collect_Primitive_Operations (T);
3469 Elmt := First_Elmt (Op_List);
3470 while Present (Elmt) loop
3471 if Nkind (Node (Elmt)) = N_Defining_Operator_Symbol then
3472 Set_Is_Potentially_Use_Visible (Node (Elmt), False);
3484 ----------------------
3485 -- Find_Direct_Name --
3486 ----------------------
3488 procedure Find_Direct_Name (N : Node_Id) is
3493 Inst : Entity_Id := Empty;
3494 -- Enclosing instance, if any
3496 Homonyms : Entity_Id;
3497 -- Saves start of homonym chain
3499 Nvis_Entity : Boolean;
3500 -- Set True to indicate that there is at least one entity on the homonym
3501 -- chain which, while not visible, is visible enough from the user point
3502 -- of view to warrant an error message of "not visible" rather than
3505 Nvis_Is_Private_Subprg : Boolean := False;
3506 -- Ada 2005 (AI-262): Set True to indicate that a form of Beaujolais
3507 -- effect concerning library subprograms has been detected. Used to
3508 -- generate the precise error message.
3510 function From_Actual_Package (E : Entity_Id) return Boolean;
3511 -- Returns true if the entity is declared in a package that is
3512 -- an actual for a formal package of the current instance. Such an
3513 -- entity requires special handling because it may be use-visible
3514 -- but hides directly visible entities defined outside the instance.
3516 function Is_Actual_Parameter return Boolean;
3517 -- This function checks if the node N is an identifier that is an actual
3518 -- parameter of a procedure call. If so it returns True, otherwise it
3519 -- return False. The reason for this check is that at this stage we do
3520 -- not know what procedure is being called if the procedure might be
3521 -- overloaded, so it is premature to go setting referenced flags or
3522 -- making calls to Generate_Reference. We will wait till Resolve_Actuals
3523 -- for that processing
3525 function Known_But_Invisible (E : Entity_Id) return Boolean;
3526 -- This function determines whether the entity E (which is not
3527 -- visible) can reasonably be considered to be known to the writer
3528 -- of the reference. This is a heuristic test, used only for the
3529 -- purposes of figuring out whether we prefer to complain that an
3530 -- entity is undefined or invisible (and identify the declaration
3531 -- of the invisible entity in the latter case). The point here is
3532 -- that we don't want to complain that something is invisible and
3533 -- then point to something entirely mysterious to the writer.
3535 procedure Nvis_Messages;
3536 -- Called if there are no visible entries for N, but there is at least
3537 -- one non-directly visible, or hidden declaration. This procedure
3538 -- outputs an appropriate set of error messages.
3540 procedure Undefined (Nvis : Boolean);
3541 -- This function is called if the current node has no corresponding
3542 -- visible entity or entities. The value set in Msg indicates whether
3543 -- an error message was generated (multiple error messages for the
3544 -- same variable are generally suppressed, see body for details).
3545 -- Msg is True if an error message was generated, False if not. This
3546 -- value is used by the caller to determine whether or not to output
3547 -- additional messages where appropriate. The parameter is set False
3548 -- to get the message "X is undefined", and True to get the message
3549 -- "X is not visible".
3551 -------------------------
3552 -- From_Actual_Package --
3553 -------------------------
3555 function From_Actual_Package (E : Entity_Id) return Boolean is
3556 Scop : constant Entity_Id := Scope (E);
3560 if not In_Instance then
3563 Inst := Current_Scope;
3564 while Present (Inst)
3565 and then Ekind (Inst) /= E_Package
3566 and then not Is_Generic_Instance (Inst)
3568 Inst := Scope (Inst);
3575 Act := First_Entity (Inst);
3576 while Present (Act) loop
3577 if Ekind (Act) = E_Package then
3579 -- Check for end of actuals list
3581 if Renamed_Object (Act) = Inst then
3584 elsif Present (Associated_Formal_Package (Act))
3585 and then Renamed_Object (Act) = Scop
3587 -- Entity comes from (instance of) formal package
3602 end From_Actual_Package;
3604 -------------------------
3605 -- Is_Actual_Parameter --
3606 -------------------------
3608 function Is_Actual_Parameter return Boolean is
3611 Nkind (N) = N_Identifier
3613 (Nkind (Parent (N)) = N_Procedure_Call_Statement
3615 (Nkind (Parent (N)) = N_Parameter_Association
3616 and then N = Explicit_Actual_Parameter (Parent (N))
3617 and then Nkind (Parent (Parent (N))) =
3618 N_Procedure_Call_Statement));
3619 end Is_Actual_Parameter;
3621 -------------------------
3622 -- Known_But_Invisible --
3623 -------------------------
3625 function Known_But_Invisible (E : Entity_Id) return Boolean is
3626 Fname : File_Name_Type;
3629 -- Entities in Standard are always considered to be known
3631 if Sloc (E) <= Standard_Location then
3634 -- An entity that does not come from source is always considered
3635 -- to be unknown, since it is an artifact of code expansion.
3637 elsif not Comes_From_Source (E) then
3640 -- In gnat internal mode, we consider all entities known
3642 elsif GNAT_Mode then
3646 -- Here we have an entity that is not from package Standard, and
3647 -- which comes from Source. See if it comes from an internal file.
3649 Fname := Unit_File_Name (Get_Source_Unit (E));
3651 -- Case of from internal file
3653 if Is_Internal_File_Name (Fname) then
3655 -- Private part entities in internal files are never considered
3656 -- to be known to the writer of normal application code.
3658 if Is_Hidden (E) then
3662 -- Entities from System packages other than System and
3663 -- System.Storage_Elements are not considered to be known.
3664 -- System.Auxxxx files are also considered known to the user.
3666 -- Should refine this at some point to generally distinguish
3667 -- between known and unknown internal files ???
3669 Get_Name_String (Fname);
3674 Name_Buffer (1 .. 2) /= "s-"
3676 Name_Buffer (3 .. 8) = "stoele"
3678 Name_Buffer (3 .. 5) = "aux";
3680 -- If not an internal file, then entity is definitely known,
3681 -- even if it is in a private part (the message generated will
3682 -- note that it is in a private part)
3687 end Known_But_Invisible;
3693 procedure Nvis_Messages is
3694 Comp_Unit : Node_Id;
3696 Hidden : Boolean := False;
3700 -- Ada 2005 (AI-262): Generate a precise error concerning the
3701 -- Beaujolais effect that was previously detected
3703 if Nvis_Is_Private_Subprg then
3705 pragma Assert (Nkind (E2) = N_Defining_Identifier
3706 and then Ekind (E2) = E_Function
3707 and then Scope (E2) = Standard_Standard
3708 and then Has_Private_With (E2));
3710 -- Find the sloc corresponding to the private with'ed unit
3712 Comp_Unit := Cunit (Current_Sem_Unit);
3713 Error_Msg_Sloc := No_Location;
3715 Item := First (Context_Items (Comp_Unit));
3716 while Present (Item) loop
3717 if Nkind (Item) = N_With_Clause
3718 and then Private_Present (Item)
3719 and then Entity (Name (Item)) = E2
3721 Error_Msg_Sloc := Sloc (Item);
3728 pragma Assert (Error_Msg_Sloc /= No_Location);
3730 Error_Msg_N ("(Ada 2005): hidden by private with clause #", N);
3734 Undefined (Nvis => True);
3738 -- First loop does hidden declarations
3741 while Present (Ent) loop
3742 if Is_Potentially_Use_Visible (Ent) then
3744 Error_Msg_N -- CODEFIX
3745 ("multiple use clauses cause hiding!", N);
3749 Error_Msg_Sloc := Sloc (Ent);
3750 Error_Msg_N ("hidden declaration#!", N);
3753 Ent := Homonym (Ent);
3756 -- If we found hidden declarations, then that's enough, don't
3757 -- bother looking for non-visible declarations as well.
3763 -- Second loop does non-directly visible declarations
3766 while Present (Ent) loop
3767 if not Is_Potentially_Use_Visible (Ent) then
3769 -- Do not bother the user with unknown entities
3771 if not Known_But_Invisible (Ent) then
3775 Error_Msg_Sloc := Sloc (Ent);
3777 -- Output message noting that there is a non-visible
3778 -- declaration, distinguishing the private part case.
3780 if Is_Hidden (Ent) then
3781 Error_Msg_N ("non-visible (private) declaration#!", N);
3783 Error_Msg_N ("non-visible declaration#!", N);
3785 if Is_Compilation_Unit (Ent)
3787 Nkind (Parent (Parent (N))) = N_Use_Package_Clause
3789 Error_Msg_Qual_Level := 99;
3790 Error_Msg_NE ("\\missing `WITH &;`", N, Ent);
3791 Error_Msg_Qual_Level := 0;
3795 -- Set entity and its containing package as referenced. We
3796 -- can't be sure of this, but this seems a better choice
3797 -- to avoid unused entity messages.
3799 if Comes_From_Source (Ent) then
3800 Set_Referenced (Ent);
3801 Set_Referenced (Cunit_Entity (Get_Source_Unit (Ent)));
3806 Ent := Homonym (Ent);
3815 procedure Undefined (Nvis : Boolean) is
3816 Emsg : Error_Msg_Id;
3819 -- We should never find an undefined internal name. If we do, then
3820 -- see if we have previous errors. If so, ignore on the grounds that
3821 -- it is probably a cascaded message (e.g. a block label from a badly
3822 -- formed block). If no previous errors, then we have a real internal
3823 -- error of some kind so raise an exception.
3825 if Is_Internal_Name (Chars (N)) then
3826 if Total_Errors_Detected /= 0 then
3829 raise Program_Error;
3833 -- A very specialized error check, if the undefined variable is
3834 -- a case tag, and the case type is an enumeration type, check
3835 -- for a possible misspelling, and if so, modify the identifier
3837 -- Named aggregate should also be handled similarly ???
3839 if Nkind (N) = N_Identifier
3840 and then Nkind (Parent (N)) = N_Case_Statement_Alternative
3843 Case_Stm : constant Node_Id := Parent (Parent (N));
3844 Case_Typ : constant Entity_Id := Etype (Expression (Case_Stm));
3849 if Is_Enumeration_Type (Case_Typ)
3850 and then not Is_Standard_Character_Type (Case_Typ)
3852 Lit := First_Literal (Case_Typ);
3853 Get_Name_String (Chars (Lit));
3855 if Chars (Lit) /= Chars (N)
3856 and then Is_Bad_Spelling_Of (Chars (N), Chars (Lit)) then
3857 Error_Msg_Node_2 := Lit;
3859 ("& is undefined, assume misspelling of &", N);
3860 Rewrite (N, New_Occurrence_Of (Lit, Sloc (N)));
3864 Lit := Next_Literal (Lit);
3869 -- Normal processing
3871 Set_Entity (N, Any_Id);
3872 Set_Etype (N, Any_Type);
3874 -- We use the table Urefs to keep track of entities for which we
3875 -- have issued errors for undefined references. Multiple errors
3876 -- for a single name are normally suppressed, however we modify
3877 -- the error message to alert the programmer to this effect.
3879 for J in Urefs.First .. Urefs.Last loop
3880 if Chars (N) = Chars (Urefs.Table (J).Node) then
3881 if Urefs.Table (J).Err /= No_Error_Msg
3882 and then Sloc (N) /= Urefs.Table (J).Loc
3884 Error_Msg_Node_1 := Urefs.Table (J).Node;
3886 if Urefs.Table (J).Nvis then
3887 Change_Error_Text (Urefs.Table (J).Err,
3888 "& is not visible (more references follow)");
3890 Change_Error_Text (Urefs.Table (J).Err,
3891 "& is undefined (more references follow)");
3894 Urefs.Table (J).Err := No_Error_Msg;
3897 -- Although we will set Msg False, and thus suppress the
3898 -- message, we also set Error_Posted True, to avoid any
3899 -- cascaded messages resulting from the undefined reference.
3902 Set_Error_Posted (N, True);
3907 -- If entry not found, this is first undefined occurrence
3910 Error_Msg_N ("& is not visible!", N);
3914 Error_Msg_N ("& is undefined!", N);
3917 -- A very bizarre special check, if the undefined identifier
3918 -- is put or put_line, then add a special error message (since
3919 -- this is a very common error for beginners to make).
3921 if Chars (N) = Name_Put or else Chars (N) = Name_Put_Line then
3923 ("\\possible missing `WITH Ada.Text_'I'O; " &
3924 "USE Ada.Text_'I'O`!", N);
3926 -- Another special check if N is the prefix of a selected
3927 -- component which is a known unit, add message complaining
3928 -- about missing with for this unit.
3930 elsif Nkind (Parent (N)) = N_Selected_Component
3931 and then N = Prefix (Parent (N))
3932 and then Is_Known_Unit (Parent (N))
3934 Error_Msg_Node_2 := Selector_Name (Parent (N));
3935 Error_Msg_N ("\\missing `WITH &.&;`", Prefix (Parent (N)));
3938 -- Now check for possible misspellings
3942 Ematch : Entity_Id := Empty;
3944 Last_Name_Id : constant Name_Id :=
3945 Name_Id (Nat (First_Name_Id) +
3946 Name_Entries_Count - 1);
3949 for Nam in First_Name_Id .. Last_Name_Id loop
3950 E := Get_Name_Entity_Id (Nam);
3953 and then (Is_Immediately_Visible (E)
3955 Is_Potentially_Use_Visible (E))
3957 if Is_Bad_Spelling_Of (Chars (N), Nam) then
3964 if Present (Ematch) then
3965 Error_Msg_NE -- CODEFIX
3966 ("\possible misspelling of&", N, Ematch);
3971 -- Make entry in undefined references table unless the full errors
3972 -- switch is set, in which case by refraining from generating the
3973 -- table entry, we guarantee that we get an error message for every
3974 -- undefined reference.
3976 if not All_Errors_Mode then
3987 -- Start of processing for Find_Direct_Name
3990 -- If the entity pointer is already set, this is an internal node, or
3991 -- a node that is analyzed more than once, after a tree modification.
3992 -- In such a case there is no resolution to perform, just set the type.
3994 if Present (Entity (N)) then
3995 if Is_Type (Entity (N)) then
3996 Set_Etype (N, Entity (N));
4000 Entyp : constant Entity_Id := Etype (Entity (N));
4003 -- One special case here. If the Etype field is already set,
4004 -- and references the packed array type corresponding to the
4005 -- etype of the referenced entity, then leave it alone. This
4006 -- happens for trees generated from Exp_Pakd, where expressions
4007 -- can be deliberately "mis-typed" to the packed array type.
4009 if Is_Array_Type (Entyp)
4010 and then Is_Packed (Entyp)
4011 and then Present (Etype (N))
4012 and then Etype (N) = Packed_Array_Type (Entyp)
4016 -- If not that special case, then just reset the Etype
4019 Set_Etype (N, Etype (Entity (N)));
4027 -- Here if Entity pointer was not set, we need full visibility analysis
4028 -- First we generate debugging output if the debug E flag is set.
4030 if Debug_Flag_E then
4031 Write_Str ("Looking for ");
4032 Write_Name (Chars (N));
4036 Homonyms := Current_Entity (N);
4037 Nvis_Entity := False;
4040 while Present (E) loop
4042 -- If entity is immediately visible or potentially use visible, then
4043 -- process the entity and we are done.
4045 if Is_Immediately_Visible (E) then
4046 goto Immediately_Visible_Entity;
4048 elsif Is_Potentially_Use_Visible (E) then
4049 goto Potentially_Use_Visible_Entity;
4051 -- Note if a known but invisible entity encountered
4053 elsif Known_But_Invisible (E) then
4054 Nvis_Entity := True;
4057 -- Move to next entity in chain and continue search
4062 -- If no entries on homonym chain that were potentially visible,
4063 -- and no entities reasonably considered as non-visible, then
4064 -- we have a plain undefined reference, with no additional
4065 -- explanation required!
4067 if not Nvis_Entity then
4068 Undefined (Nvis => False);
4070 -- Otherwise there is at least one entry on the homonym chain that
4071 -- is reasonably considered as being known and non-visible.
4079 -- Processing for a potentially use visible entry found. We must search
4080 -- the rest of the homonym chain for two reasons. First, if there is a
4081 -- directly visible entry, then none of the potentially use-visible
4082 -- entities are directly visible (RM 8.4(10)). Second, we need to check
4083 -- for the case of multiple potentially use-visible entries hiding one
4084 -- another and as a result being non-directly visible (RM 8.4(11)).
4086 <<Potentially_Use_Visible_Entity>> declare
4087 Only_One_Visible : Boolean := True;
4088 All_Overloadable : Boolean := Is_Overloadable (E);
4092 while Present (E2) loop
4093 if Is_Immediately_Visible (E2) then
4095 -- If the use-visible entity comes from the actual for a
4096 -- formal package, it hides a directly visible entity from
4097 -- outside the instance.
4099 if From_Actual_Package (E)
4100 and then Scope_Depth (E2) < Scope_Depth (Inst)
4105 goto Immediately_Visible_Entity;
4108 elsif Is_Potentially_Use_Visible (E2) then
4109 Only_One_Visible := False;
4110 All_Overloadable := All_Overloadable and Is_Overloadable (E2);
4112 -- Ada 2005 (AI-262): Protect against a form of Beaujolais effect
4113 -- that can occur in private_with clauses. Example:
4116 -- private with B; package A is
4117 -- package C is function B return Integer;
4119 -- V1 : Integer := B;
4120 -- private function B return Integer;
4121 -- V2 : Integer := B;
4124 -- V1 resolves to A.B, but V2 resolves to library unit B
4126 elsif Ekind (E2) = E_Function
4127 and then Scope (E2) = Standard_Standard
4128 and then Has_Private_With (E2)
4130 Only_One_Visible := False;
4131 All_Overloadable := False;
4132 Nvis_Is_Private_Subprg := True;
4139 -- On falling through this loop, we have checked that there are no
4140 -- immediately visible entities. Only_One_Visible is set if exactly
4141 -- one potentially use visible entity exists. All_Overloadable is
4142 -- set if all the potentially use visible entities are overloadable.
4143 -- The condition for legality is that either there is one potentially
4144 -- use visible entity, or if there is more than one, then all of them
4145 -- are overloadable.
4147 if Only_One_Visible or All_Overloadable then
4150 -- If there is more than one potentially use-visible entity and at
4151 -- least one of them non-overloadable, we have an error (RM 8.4(11).
4152 -- Note that E points to the first such entity on the homonym list.
4153 -- Special case: if one of the entities is declared in an actual
4154 -- package, it was visible in the generic, and takes precedence over
4155 -- other entities that are potentially use-visible. Same if it is
4156 -- declared in a local instantiation of the current instance.
4161 -- Find current instance
4163 Inst := Current_Scope;
4164 while Present (Inst)
4165 and then Inst /= Standard_Standard
4167 if Is_Generic_Instance (Inst) then
4171 Inst := Scope (Inst);
4175 while Present (E2) loop
4176 if From_Actual_Package (E2)
4178 (Is_Generic_Instance (Scope (E2))
4179 and then Scope_Depth (Scope (E2)) > Scope_Depth (Inst))
4192 Is_Predefined_File_Name (Unit_File_Name (Current_Sem_Unit))
4194 -- A use-clause in the body of a system file creates conflict
4195 -- with some entity in a user scope, while rtsfind is active.
4196 -- Keep only the entity coming from another predefined unit.
4199 while Present (E2) loop
4200 if Is_Predefined_File_Name
4201 (Unit_File_Name (Get_Source_Unit (Sloc (E2))))
4210 -- Entity must exist because predefined unit is correct
4212 raise Program_Error;
4221 -- Come here with E set to the first immediately visible entity on
4222 -- the homonym chain. This is the one we want unless there is another
4223 -- immediately visible entity further on in the chain for an inner
4224 -- scope (RM 8.3(8)).
4226 <<Immediately_Visible_Entity>> declare
4231 -- Find scope level of initial entity. When compiling through
4232 -- Rtsfind, the previous context is not completely invisible, and
4233 -- an outer entity may appear on the chain, whose scope is below
4234 -- the entry for Standard that delimits the current scope stack.
4235 -- Indicate that the level for this spurious entry is outside of
4236 -- the current scope stack.
4238 Level := Scope_Stack.Last;
4240 Scop := Scope_Stack.Table (Level).Entity;
4241 exit when Scop = Scope (E);
4243 exit when Scop = Standard_Standard;
4246 -- Now search remainder of homonym chain for more inner entry
4247 -- If the entity is Standard itself, it has no scope, and we
4248 -- compare it with the stack entry directly.
4251 while Present (E2) loop
4252 if Is_Immediately_Visible (E2) then
4254 -- If a generic package contains a local declaration that
4255 -- has the same name as the generic, there may be a visibility
4256 -- conflict in an instance, where the local declaration must
4257 -- also hide the name of the corresponding package renaming.
4258 -- We check explicitly for a package declared by a renaming,
4259 -- whose renamed entity is an instance that is on the scope
4260 -- stack, and that contains a homonym in the same scope. Once
4261 -- we have found it, we know that the package renaming is not
4262 -- immediately visible, and that the identifier denotes the
4263 -- other entity (and its homonyms if overloaded).
4265 if Scope (E) = Scope (E2)
4266 and then Ekind (E) = E_Package
4267 and then Present (Renamed_Object (E))
4268 and then Is_Generic_Instance (Renamed_Object (E))
4269 and then In_Open_Scopes (Renamed_Object (E))
4270 and then Comes_From_Source (N)
4272 Set_Is_Immediately_Visible (E, False);
4276 for J in Level + 1 .. Scope_Stack.Last loop
4277 if Scope_Stack.Table (J).Entity = Scope (E2)
4278 or else Scope_Stack.Table (J).Entity = E2
4291 -- At the end of that loop, E is the innermost immediately
4292 -- visible entity, so we are all set.
4295 -- Come here with entity found, and stored in E
4299 -- When distribution features are available (Get_PCS_Name /=
4300 -- Name_No_DSA), a remote access-to-subprogram type is converted
4301 -- into a record type holding whatever information is needed to
4302 -- perform a remote call on an RCI subprogram. In that case we
4303 -- rewrite any occurrence of the RAS type into the equivalent record
4304 -- type here. 'Access attribute references and RAS dereferences are
4305 -- then implemented using specific TSSs. However when distribution is
4306 -- not available (case of Get_PCS_Name = Name_No_DSA), we bypass the
4307 -- generation of these TSSs, and we must keep the RAS type in its
4308 -- original access-to-subprogram form (since all calls through a
4309 -- value of such type will be local anyway in the absence of a PCS).
4311 if Comes_From_Source (N)
4312 and then Is_Remote_Access_To_Subprogram_Type (E)
4313 and then Expander_Active
4314 and then Get_PCS_Name /= Name_No_DSA
4317 New_Occurrence_Of (Equivalent_Type (E), Sloc (N)));
4322 -- Why no Style_Check here???
4327 Set_Etype (N, Get_Full_View (Etype (E)));
4330 if Debug_Flag_E then
4331 Write_Str (" found ");
4332 Write_Entity_Info (E, " ");
4335 -- If the Ekind of the entity is Void, it means that all homonyms
4336 -- are hidden from all visibility (RM 8.3(5,14-20)). However, this
4337 -- test is skipped if the current scope is a record and the name is
4338 -- a pragma argument expression (case of Atomic and Volatile pragmas
4339 -- and possibly other similar pragmas added later, which are allowed
4340 -- to reference components in the current record).
4342 if Ekind (E) = E_Void
4344 (not Is_Record_Type (Current_Scope)
4345 or else Nkind (Parent (N)) /= N_Pragma_Argument_Association)
4347 Premature_Usage (N);
4349 -- If the entity is overloadable, collect all interpretations of the
4350 -- name for subsequent overload resolution. We optimize a bit here to
4351 -- do this only if we have an overloadable entity that is not on its
4352 -- own on the homonym chain.
4354 elsif Is_Overloadable (E)
4355 and then (Present (Homonym (E)) or else Current_Entity (N) /= E)
4357 Collect_Interps (N);
4359 -- If no homonyms were visible, the entity is unambiguous
4361 if not Is_Overloaded (N) then
4362 if not Is_Actual_Parameter then
4363 Generate_Reference (E, N);
4367 -- Case of non-overloadable entity, set the entity providing that
4368 -- we do not have the case of a discriminant reference within a
4369 -- default expression. Such references are replaced with the
4370 -- corresponding discriminal, which is the formal corresponding to
4371 -- to the discriminant in the initialization procedure.
4374 -- Entity is unambiguous, indicate that it is referenced here
4376 -- For a renaming of an object, always generate simple reference,
4377 -- we don't try to keep track of assignments in this case.
4379 if Is_Object (E) and then Present (Renamed_Object (E)) then
4380 Generate_Reference (E, N);
4382 -- If the renamed entity is a private protected component,
4383 -- reference the original component as well. This needs to be
4384 -- done because the private renamings are installed before any
4385 -- analysis has occurred. Reference to a private component will
4386 -- resolve to the renaming and the original component will be
4387 -- left unreferenced, hence the following.
4389 if Is_Prival (E) then
4390 Generate_Reference (Prival_Link (E), N);
4393 -- One odd case is that we do not want to set the Referenced flag
4394 -- if the entity is a label, and the identifier is the label in
4395 -- the source, since this is not a reference from the point of
4396 -- view of the user.
4398 elsif Nkind (Parent (N)) = N_Label then
4400 R : constant Boolean := Referenced (E);
4403 -- Generate reference unless this is an actual parameter
4404 -- (see comment below)
4406 if Is_Actual_Parameter then
4407 Generate_Reference (E, N);
4408 Set_Referenced (E, R);
4412 -- Normal case, not a label: generate reference
4414 -- ??? It is too early to generate a reference here even if
4415 -- the entity is unambiguous, because the tree is not
4416 -- sufficiently typed at this point for Generate_Reference to
4417 -- determine whether this reference modifies the denoted object
4418 -- (because implicit dereferences cannot be identified prior to
4419 -- full type resolution).
4421 -- The Is_Actual_Parameter routine takes care of one of these
4422 -- cases but there are others probably ???
4425 if not Is_Actual_Parameter then
4426 Generate_Reference (E, N);
4429 Check_Nested_Access (E);
4432 -- Set Entity, with style check if need be. For a discriminant
4433 -- reference, replace by the corresponding discriminal, i.e. the
4434 -- parameter of the initialization procedure that corresponds to
4435 -- the discriminant. If this replacement is being performed, there
4436 -- is no style check to perform.
4438 -- This replacement must not be done if we are currently
4439 -- processing a generic spec or body, because the discriminal
4440 -- has not been not generated in this case.
4442 -- The replacement is also skipped if we are in special
4443 -- spec-expression mode. Why is this skipped in this case ???
4445 if not In_Spec_Expression
4446 or else Ekind (E) /= E_Discriminant
4447 or else Inside_A_Generic
4449 Set_Entity_With_Style_Check (N, E);
4451 -- The replacement is not done either for a task discriminant that
4452 -- appears in a default expression of an entry parameter. See
4453 -- Expand_Discriminant in exp_ch2 for details on their handling.
4455 elsif Is_Concurrent_Type (Scope (E)) then
4462 and then not Nkind_In (P, N_Parameter_Specification,
4463 N_Component_Declaration)
4469 and then Nkind (P) = N_Parameter_Specification
4473 Set_Entity (N, Discriminal (E));
4477 -- Otherwise, this is a discriminant in a context in which
4478 -- it is a reference to the corresponding parameter of the
4479 -- init proc for the enclosing type.
4482 Set_Entity (N, Discriminal (E));
4486 end Find_Direct_Name;
4488 ------------------------
4489 -- Find_Expanded_Name --
4490 ------------------------
4492 -- This routine searches the homonym chain of the entity until it finds
4493 -- an entity declared in the scope denoted by the prefix. If the entity
4494 -- is private, it may nevertheless be immediately visible, if we are in
4495 -- the scope of its declaration.
4497 procedure Find_Expanded_Name (N : Node_Id) is
4498 Selector : constant Node_Id := Selector_Name (N);
4499 Candidate : Entity_Id := Empty;
4505 P_Name := Entity (Prefix (N));
4508 -- If the prefix is a renamed package, look for the entity in the
4509 -- original package.
4511 if Ekind (P_Name) = E_Package
4512 and then Present (Renamed_Object (P_Name))
4514 P_Name := Renamed_Object (P_Name);
4516 -- Rewrite node with entity field pointing to renamed object
4518 Rewrite (Prefix (N), New_Copy (Prefix (N)));
4519 Set_Entity (Prefix (N), P_Name);
4521 -- If the prefix is an object of a concurrent type, look for
4522 -- the entity in the associated task or protected type.
4524 elsif Is_Concurrent_Type (Etype (P_Name)) then
4525 P_Name := Etype (P_Name);
4528 Id := Current_Entity (Selector);
4531 Is_New_Candidate : Boolean;
4534 while Present (Id) loop
4535 if Scope (Id) = P_Name then
4537 Is_New_Candidate := True;
4539 -- Ada 2005 (AI-217): Handle shadow entities associated with types
4540 -- declared in limited-withed nested packages. We don't need to
4541 -- handle E_Incomplete_Subtype entities because the entities in
4542 -- the limited view are always E_Incomplete_Type entities (see
4543 -- Build_Limited_Views). Regarding the expression used to evaluate
4544 -- the scope, it is important to note that the limited view also
4545 -- has shadow entities associated nested packages. For this reason
4546 -- the correct scope of the entity is the scope of the real entity
4547 -- The non-limited view may itself be incomplete, in which case
4548 -- get the full view if available.
4550 elsif From_With_Type (Id)
4551 and then Is_Type (Id)
4552 and then Ekind (Id) = E_Incomplete_Type
4553 and then Present (Non_Limited_View (Id))
4554 and then Scope (Non_Limited_View (Id)) = P_Name
4556 Candidate := Get_Full_View (Non_Limited_View (Id));
4557 Is_New_Candidate := True;
4560 Is_New_Candidate := False;
4563 if Is_New_Candidate then
4564 if Is_Child_Unit (Id) then
4565 exit when Is_Visible_Child_Unit (Id)
4566 or else Is_Immediately_Visible (Id);
4569 exit when not Is_Hidden (Id)
4570 or else Is_Immediately_Visible (Id);
4579 and then (Ekind (P_Name) = E_Procedure
4581 Ekind (P_Name) = E_Function)
4582 and then Is_Generic_Instance (P_Name)
4584 -- Expanded name denotes entity in (instance of) generic subprogram.
4585 -- The entity may be in the subprogram instance, or may denote one of
4586 -- the formals, which is declared in the enclosing wrapper package.
4588 P_Name := Scope (P_Name);
4590 Id := Current_Entity (Selector);
4591 while Present (Id) loop
4592 exit when Scope (Id) = P_Name;
4597 if No (Id) or else Chars (Id) /= Chars (Selector) then
4598 Set_Etype (N, Any_Type);
4600 -- If we are looking for an entity defined in System, try to find it
4601 -- in the child package that may have been provided as an extension
4602 -- to System. The Extend_System pragma will have supplied the name of
4603 -- the extension, which may have to be loaded.
4605 if Chars (P_Name) = Name_System
4606 and then Scope (P_Name) = Standard_Standard
4607 and then Present (System_Extend_Unit)
4608 and then Present_System_Aux (N)
4610 Set_Entity (Prefix (N), System_Aux_Id);
4611 Find_Expanded_Name (N);
4614 elsif Nkind (Selector) = N_Operator_Symbol
4615 and then Has_Implicit_Operator (N)
4617 -- There is an implicit instance of the predefined operator in
4618 -- the given scope. The operator entity is defined in Standard.
4619 -- Has_Implicit_Operator makes the node into an Expanded_Name.
4623 elsif Nkind (Selector) = N_Character_Literal
4624 and then Has_Implicit_Character_Literal (N)
4626 -- If there is no literal defined in the scope denoted by the
4627 -- prefix, the literal may belong to (a type derived from)
4628 -- Standard_Character, for which we have no explicit literals.
4633 -- If the prefix is a single concurrent object, use its name in
4634 -- the error message, rather than that of the anonymous type.
4636 if Is_Concurrent_Type (P_Name)
4637 and then Is_Internal_Name (Chars (P_Name))
4639 Error_Msg_Node_2 := Entity (Prefix (N));
4641 Error_Msg_Node_2 := P_Name;
4644 if P_Name = System_Aux_Id then
4645 P_Name := Scope (P_Name);
4646 Set_Entity (Prefix (N), P_Name);
4649 if Present (Candidate) then
4651 -- If we know that the unit is a child unit we can give a more
4652 -- accurate error message.
4654 if Is_Child_Unit (Candidate) then
4656 -- If the candidate is a private child unit and we are in
4657 -- the visible part of a public unit, specialize the error
4658 -- message. There might be a private with_clause for it,
4659 -- but it is not currently active.
4661 if Is_Private_Descendant (Candidate)
4662 and then Ekind (Current_Scope) = E_Package
4663 and then not In_Private_Part (Current_Scope)
4664 and then not Is_Private_Descendant (Current_Scope)
4666 Error_Msg_N ("private child unit& is not visible here",
4669 -- Normal case where we have a missing with for a child unit
4672 Error_Msg_Qual_Level := 99;
4673 Error_Msg_NE ("missing `WITH &;`", Selector, Candidate);
4674 Error_Msg_Qual_Level := 0;
4677 -- Here we don't know that this is a child unit
4680 Error_Msg_NE ("& is not a visible entity of&", N, Selector);
4684 -- Within the instantiation of a child unit, the prefix may
4685 -- denote the parent instance, but the selector has the name
4686 -- of the original child. Find whether we are within the
4687 -- corresponding instance, and get the proper entity, which
4688 -- can only be an enclosing scope.
4691 and then In_Open_Scopes (P_Name)
4692 and then Is_Generic_Instance (P_Name)
4695 S : Entity_Id := Current_Scope;
4699 for J in reverse 0 .. Scope_Stack.Last loop
4700 S := Scope_Stack.Table (J).Entity;
4702 exit when S = Standard_Standard;
4704 if Ekind (S) = E_Function
4705 or else Ekind (S) = E_Package
4706 or else Ekind (S) = E_Procedure
4708 P := Generic_Parent (Specification
4709 (Unit_Declaration_Node (S)));
4712 and then Chars (Scope (P)) = Chars (O_Name)
4713 and then Chars (P) = Chars (Selector)
4724 -- If this is a selection from Ada, System or Interfaces, then
4725 -- we assume a missing with for the corresponding package.
4727 if Is_Known_Unit (N) then
4728 if not Error_Posted (N) then
4729 Error_Msg_Node_2 := Selector;
4730 Error_Msg_N ("missing `WITH &.&;`", Prefix (N));
4733 -- If this is a selection from a dummy package, then suppress
4734 -- the error message, of course the entity is missing if the
4735 -- package is missing!
4737 elsif Sloc (Error_Msg_Node_2) = No_Location then
4740 -- Here we have the case of an undefined component
4743 Error_Msg_NE ("& not declared in&", N, Selector);
4745 -- Check for misspelling of some entity in prefix
4747 Id := First_Entity (P_Name);
4748 while Present (Id) loop
4749 if Is_Bad_Spelling_Of (Chars (Id), Chars (Selector))
4750 and then not Is_Internal_Name (Chars (Id))
4752 Error_Msg_NE -- CODEFIX
4753 ("possible misspelling of&", Selector, Id);
4760 -- Specialize the message if this may be an instantiation
4761 -- of a child unit that was not mentioned in the context.
4763 if Nkind (Parent (N)) = N_Package_Instantiation
4764 and then Is_Generic_Instance (Entity (Prefix (N)))
4765 and then Is_Compilation_Unit
4766 (Generic_Parent (Parent (Entity (Prefix (N)))))
4768 Error_Msg_Node_2 := Selector;
4769 Error_Msg_N ("\missing `WITH &.&;`", Prefix (N));
4779 if Comes_From_Source (N)
4780 and then Is_Remote_Access_To_Subprogram_Type (Id)
4781 and then Present (Equivalent_Type (Id))
4783 -- If we are not actually generating distribution code (i.e. the
4784 -- current PCS is the dummy non-distributed version), then the
4785 -- Equivalent_Type will be missing, and Id should be treated as
4786 -- a regular access-to-subprogram type.
4788 Id := Equivalent_Type (Id);
4789 Set_Chars (Selector, Chars (Id));
4792 -- Ada 2005 (AI-50217): Check usage of entities in limited withed units
4794 if Ekind (P_Name) = E_Package
4795 and then From_With_Type (P_Name)
4797 if From_With_Type (Id)
4798 or else Is_Type (Id)
4799 or else Ekind (Id) = E_Package
4804 ("limited withed package can only be used to access "
4805 & "incomplete types",
4810 if Is_Task_Type (P_Name)
4811 and then ((Ekind (Id) = E_Entry
4812 and then Nkind (Parent (N)) /= N_Attribute_Reference)
4814 (Ekind (Id) = E_Entry_Family
4816 Nkind (Parent (Parent (N))) /= N_Attribute_Reference))
4818 -- It is an entry call after all, either to the current task (which
4819 -- will deadlock) or to an enclosing task.
4821 Analyze_Selected_Component (N);
4825 Change_Selected_Component_To_Expanded_Name (N);
4827 -- Do style check and generate reference, but skip both steps if this
4828 -- entity has homonyms, since we may not have the right homonym set yet.
4829 -- The proper homonym will be set during the resolve phase.
4831 if Has_Homonym (Id) then
4834 Set_Entity_With_Style_Check (N, Id);
4835 Generate_Reference (Id, N);
4838 if Is_Type (Id) then
4841 Set_Etype (N, Get_Full_View (Etype (Id)));
4844 -- If the Ekind of the entity is Void, it means that all homonyms are
4845 -- hidden from all visibility (RM 8.3(5,14-20)).
4847 if Ekind (Id) = E_Void then
4848 Premature_Usage (N);
4850 elsif Is_Overloadable (Id)
4851 and then Present (Homonym (Id))
4854 H : Entity_Id := Homonym (Id);
4857 while Present (H) loop
4858 if Scope (H) = Scope (Id)
4861 or else Is_Immediately_Visible (H))
4863 Collect_Interps (N);
4870 -- If an extension of System is present, collect possible explicit
4871 -- overloadings declared in the extension.
4873 if Chars (P_Name) = Name_System
4874 and then Scope (P_Name) = Standard_Standard
4875 and then Present (System_Extend_Unit)
4876 and then Present_System_Aux (N)
4878 H := Current_Entity (Id);
4880 while Present (H) loop
4881 if Scope (H) = System_Aux_Id then
4882 Add_One_Interp (N, H, Etype (H));
4891 if Nkind (Selector_Name (N)) = N_Operator_Symbol
4892 and then Scope (Id) /= Standard_Standard
4894 -- In addition to user-defined operators in the given scope, there
4895 -- may be an implicit instance of the predefined operator. The
4896 -- operator (defined in Standard) is found in Has_Implicit_Operator,
4897 -- and added to the interpretations. Procedure Add_One_Interp will
4898 -- determine which hides which.
4900 if Has_Implicit_Operator (N) then
4904 end Find_Expanded_Name;
4906 -------------------------
4907 -- Find_Renamed_Entity --
4908 -------------------------
4910 function Find_Renamed_Entity
4914 Is_Actual : Boolean := False) return Entity_Id
4917 I1 : Interp_Index := 0; -- Suppress junk warnings
4923 function Enclosing_Instance return Entity_Id;
4924 -- If the renaming determines the entity for the default of a formal
4925 -- subprogram nested within another instance, choose the innermost
4926 -- candidate. This is because if the formal has a box, and we are within
4927 -- an enclosing instance where some candidate interpretations are local
4928 -- to this enclosing instance, we know that the default was properly
4929 -- resolved when analyzing the generic, so we prefer the local
4930 -- candidates to those that are external. This is not always the case
4931 -- but is a reasonable heuristic on the use of nested generics. The
4932 -- proper solution requires a full renaming model.
4934 function Is_Visible_Operation (Op : Entity_Id) return Boolean;
4935 -- If the renamed entity is an implicit operator, check whether it is
4936 -- visible because its operand type is properly visible. This check
4937 -- applies to explicit renamed entities that appear in the source in a
4938 -- renaming declaration or a formal subprogram instance, but not to
4939 -- default generic actuals with a name.
4941 function Report_Overload return Entity_Id;
4942 -- List possible interpretations, and specialize message in the
4943 -- case of a generic actual.
4945 function Within (Inner, Outer : Entity_Id) return Boolean;
4946 -- Determine whether a candidate subprogram is defined within the
4947 -- enclosing instance. If yes, it has precedence over outer candidates.
4949 ------------------------
4950 -- Enclosing_Instance --
4951 ------------------------
4953 function Enclosing_Instance return Entity_Id is
4957 if not Is_Generic_Instance (Current_Scope)
4958 and then not Is_Actual
4963 S := Scope (Current_Scope);
4964 while S /= Standard_Standard loop
4965 if Is_Generic_Instance (S) then
4973 end Enclosing_Instance;
4975 --------------------------
4976 -- Is_Visible_Operation --
4977 --------------------------
4979 function Is_Visible_Operation (Op : Entity_Id) return Boolean is
4985 if Ekind (Op) /= E_Operator
4986 or else Scope (Op) /= Standard_Standard
4987 or else (In_Instance
4990 or else Present (Enclosing_Instance)))
4995 -- For a fixed point type operator, check the resulting type,
4996 -- because it may be a mixed mode integer * fixed operation.
4998 if Present (Next_Formal (First_Formal (New_S)))
4999 and then Is_Fixed_Point_Type (Etype (New_S))
5001 Typ := Etype (New_S);
5003 Typ := Etype (First_Formal (New_S));
5006 Btyp := Base_Type (Typ);
5008 if Nkind (Nam) /= N_Expanded_Name then
5009 return (In_Open_Scopes (Scope (Btyp))
5010 or else Is_Potentially_Use_Visible (Btyp)
5011 or else In_Use (Btyp)
5012 or else In_Use (Scope (Btyp)));
5015 Scop := Entity (Prefix (Nam));
5017 if Ekind (Scop) = E_Package
5018 and then Present (Renamed_Object (Scop))
5020 Scop := Renamed_Object (Scop);
5023 -- Operator is visible if prefix of expanded name denotes
5024 -- scope of type, or else type is defined in System_Aux
5025 -- and the prefix denotes System.
5027 return Scope (Btyp) = Scop
5028 or else (Scope (Btyp) = System_Aux_Id
5029 and then Scope (Scope (Btyp)) = Scop);
5032 end Is_Visible_Operation;
5038 function Within (Inner, Outer : Entity_Id) return Boolean is
5042 Sc := Scope (Inner);
5043 while Sc /= Standard_Standard loop
5054 ---------------------
5055 -- Report_Overload --
5056 ---------------------
5058 function Report_Overload return Entity_Id is
5062 ("ambiguous actual subprogram&, " &
5063 "possible interpretations:", N, Nam);
5066 ("ambiguous subprogram, " &
5067 "possible interpretations:", N);
5070 List_Interps (Nam, N);
5072 end Report_Overload;
5074 -- Start of processing for Find_Renamed_Entry
5078 Candidate_Renaming := Empty;
5080 if not Is_Overloaded (Nam) then
5081 if Entity_Matches_Spec (Entity (Nam), New_S) then
5082 Candidate_Renaming := New_S;
5084 if Is_Visible_Operation (Entity (Nam)) then
5085 Old_S := Entity (Nam);
5089 Present (First_Formal (Entity (Nam)))
5090 and then Present (First_Formal (New_S))
5091 and then (Base_Type (Etype (First_Formal (Entity (Nam))))
5092 = Base_Type (Etype (First_Formal (New_S))))
5094 Candidate_Renaming := Entity (Nam);
5098 Get_First_Interp (Nam, Ind, It);
5099 while Present (It.Nam) loop
5100 if Entity_Matches_Spec (It.Nam, New_S)
5101 and then Is_Visible_Operation (It.Nam)
5103 if Old_S /= Any_Id then
5105 -- Note: The call to Disambiguate only happens if a
5106 -- previous interpretation was found, in which case I1
5107 -- has received a value.
5109 It1 := Disambiguate (Nam, I1, Ind, Etype (Old_S));
5111 if It1 = No_Interp then
5112 Inst := Enclosing_Instance;
5114 if Present (Inst) then
5115 if Within (It.Nam, Inst) then
5117 elsif Within (Old_S, Inst) then
5120 return Report_Overload;
5124 return Report_Overload;
5138 Present (First_Formal (It.Nam))
5139 and then Present (First_Formal (New_S))
5140 and then (Base_Type (Etype (First_Formal (It.Nam)))
5141 = Base_Type (Etype (First_Formal (New_S))))
5143 Candidate_Renaming := It.Nam;
5146 Get_Next_Interp (Ind, It);
5149 Set_Entity (Nam, Old_S);
5150 Set_Is_Overloaded (Nam, False);
5154 end Find_Renamed_Entity;
5156 -----------------------------
5157 -- Find_Selected_Component --
5158 -----------------------------
5160 procedure Find_Selected_Component (N : Node_Id) is
5161 P : constant Node_Id := Prefix (N);
5164 -- Entity denoted by prefix
5174 if Nkind (P) = N_Error then
5177 -- If the selector already has an entity, the node has been constructed
5178 -- in the course of expansion, and is known to be valid. Do not verify
5179 -- that it is defined for the type (it may be a private component used
5180 -- in the expansion of record equality).
5182 elsif Present (Entity (Selector_Name (N))) then
5184 or else Etype (N) = Any_Type
5187 Sel_Name : constant Node_Id := Selector_Name (N);
5188 Selector : constant Entity_Id := Entity (Sel_Name);
5192 Set_Etype (Sel_Name, Etype (Selector));
5194 if not Is_Entity_Name (P) then
5198 -- Build an actual subtype except for the first parameter
5199 -- of an init proc, where this actual subtype is by
5200 -- definition incorrect, since the object is uninitialized
5201 -- (and does not even have defined discriminants etc.)
5203 if Is_Entity_Name (P)
5204 and then Ekind (Entity (P)) = E_Function
5206 Nam := New_Copy (P);
5208 if Is_Overloaded (P) then
5209 Save_Interps (P, Nam);
5213 Make_Function_Call (Sloc (P), Name => Nam));
5215 Analyze_Selected_Component (N);
5218 elsif Ekind (Selector) = E_Component
5219 and then (not Is_Entity_Name (P)
5220 or else Chars (Entity (P)) /= Name_uInit)
5223 Build_Actual_Subtype_Of_Component (
5224 Etype (Selector), N);
5229 if No (C_Etype) then
5230 C_Etype := Etype (Selector);
5232 Insert_Action (N, C_Etype);
5233 C_Etype := Defining_Identifier (C_Etype);
5236 Set_Etype (N, C_Etype);
5239 -- If this is the name of an entry or protected operation, and
5240 -- the prefix is an access type, insert an explicit dereference,
5241 -- so that entry calls are treated uniformly.
5243 if Is_Access_Type (Etype (P))
5244 and then Is_Concurrent_Type (Designated_Type (Etype (P)))
5247 New_P : constant Node_Id :=
5248 Make_Explicit_Dereference (Sloc (P),
5249 Prefix => Relocate_Node (P));
5252 Set_Etype (P, Designated_Type (Etype (Prefix (P))));
5256 -- If the selected component appears within a default expression
5257 -- and it has an actual subtype, the pre-analysis has not yet
5258 -- completed its analysis, because Insert_Actions is disabled in
5259 -- that context. Within the init proc of the enclosing type we
5260 -- must complete this analysis, if an actual subtype was created.
5262 elsif Inside_Init_Proc then
5264 Typ : constant Entity_Id := Etype (N);
5265 Decl : constant Node_Id := Declaration_Node (Typ);
5267 if Nkind (Decl) = N_Subtype_Declaration
5268 and then not Analyzed (Decl)
5269 and then Is_List_Member (Decl)
5270 and then No (Parent (Decl))
5273 Insert_Action (N, Decl);
5280 elsif Is_Entity_Name (P) then
5281 P_Name := Entity (P);
5283 -- The prefix may denote an enclosing type which is the completion
5284 -- of an incomplete type declaration.
5286 if Is_Type (P_Name) then
5287 Set_Entity (P, Get_Full_View (P_Name));
5288 Set_Etype (P, Entity (P));
5289 P_Name := Entity (P);
5292 P_Type := Base_Type (Etype (P));
5294 if Debug_Flag_E then
5295 Write_Str ("Found prefix type to be ");
5296 Write_Entity_Info (P_Type, " "); Write_Eol;
5299 -- First check for components of a record object (not the
5300 -- result of a call, which is handled below).
5302 if Is_Appropriate_For_Record (P_Type)
5303 and then not Is_Overloadable (P_Name)
5304 and then not Is_Type (P_Name)
5306 -- Selected component of record. Type checking will validate
5307 -- name of selector.
5308 -- ??? could we rewrite an implicit dereference into an explicit
5311 Analyze_Selected_Component (N);
5313 elsif Is_Appropriate_For_Entry_Prefix (P_Type)
5314 and then not In_Open_Scopes (P_Name)
5315 and then (not Is_Concurrent_Type (Etype (P_Name))
5316 or else not In_Open_Scopes (Etype (P_Name)))
5318 -- Call to protected operation or entry. Type checking is
5319 -- needed on the prefix.
5321 Analyze_Selected_Component (N);
5323 elsif (In_Open_Scopes (P_Name)
5324 and then Ekind (P_Name) /= E_Void
5325 and then not Is_Overloadable (P_Name))
5326 or else (Is_Concurrent_Type (Etype (P_Name))
5327 and then In_Open_Scopes (Etype (P_Name)))
5329 -- Prefix denotes an enclosing loop, block, or task, i.e. an
5330 -- enclosing construct that is not a subprogram or accept.
5332 Find_Expanded_Name (N);
5334 elsif Ekind (P_Name) = E_Package then
5335 Find_Expanded_Name (N);
5337 elsif Is_Overloadable (P_Name) then
5339 -- The subprogram may be a renaming (of an enclosing scope) as
5340 -- in the case of the name of the generic within an instantiation.
5342 if (Ekind (P_Name) = E_Procedure
5343 or else Ekind (P_Name) = E_Function)
5344 and then Present (Alias (P_Name))
5345 and then Is_Generic_Instance (Alias (P_Name))
5347 P_Name := Alias (P_Name);
5350 if Is_Overloaded (P) then
5352 -- The prefix must resolve to a unique enclosing construct
5355 Found : Boolean := False;
5360 Get_First_Interp (P, Ind, It);
5361 while Present (It.Nam) loop
5362 if In_Open_Scopes (It.Nam) then
5365 "prefix must be unique enclosing scope", N);
5366 Set_Entity (N, Any_Id);
5367 Set_Etype (N, Any_Type);
5376 Get_Next_Interp (Ind, It);
5381 if In_Open_Scopes (P_Name) then
5382 Set_Entity (P, P_Name);
5383 Set_Is_Overloaded (P, False);
5384 Find_Expanded_Name (N);
5387 -- If no interpretation as an expanded name is possible, it
5388 -- must be a selected component of a record returned by a
5389 -- function call. Reformat prefix as a function call, the rest
5390 -- is done by type resolution. If the prefix is procedure or
5391 -- entry, as is P.X; this is an error.
5393 if Ekind (P_Name) /= E_Function
5394 and then (not Is_Overloaded (P)
5396 Nkind (Parent (N)) = N_Procedure_Call_Statement)
5398 -- Prefix may mention a package that is hidden by a local
5399 -- declaration: let the user know. Scan the full homonym
5400 -- chain, the candidate package may be anywhere on it.
5402 if Present (Homonym (Current_Entity (P_Name))) then
5404 P_Name := Current_Entity (P_Name);
5406 while Present (P_Name) loop
5407 exit when Ekind (P_Name) = E_Package;
5408 P_Name := Homonym (P_Name);
5411 if Present (P_Name) then
5412 Error_Msg_Sloc := Sloc (Entity (Prefix (N)));
5415 ("package& is hidden by declaration#",
5418 Set_Entity (Prefix (N), P_Name);
5419 Find_Expanded_Name (N);
5422 P_Name := Entity (Prefix (N));
5427 ("invalid prefix in selected component&", N, P_Name);
5428 Change_Selected_Component_To_Expanded_Name (N);
5429 Set_Entity (N, Any_Id);
5430 Set_Etype (N, Any_Type);
5433 Nam := New_Copy (P);
5434 Save_Interps (P, Nam);
5436 Make_Function_Call (Sloc (P), Name => Nam));
5438 Analyze_Selected_Component (N);
5442 -- Remaining cases generate various error messages
5445 -- Format node as expanded name, to avoid cascaded errors
5447 Change_Selected_Component_To_Expanded_Name (N);
5448 Set_Entity (N, Any_Id);
5449 Set_Etype (N, Any_Type);
5451 -- Issue error message, but avoid this if error issued already.
5452 -- Use identifier of prefix if one is available.
5454 if P_Name = Any_Id then
5457 elsif Ekind (P_Name) = E_Void then
5458 Premature_Usage (P);
5460 elsif Nkind (P) /= N_Attribute_Reference then
5462 "invalid prefix in selected component&", P);
5464 if Is_Access_Type (P_Type)
5465 and then Ekind (Designated_Type (P_Type)) = E_Incomplete_Type
5468 ("\dereference must not be of an incomplete type " &
5474 "invalid prefix in selected component", P);
5479 -- If prefix is not the name of an entity, it must be an expression,
5480 -- whose type is appropriate for a record. This is determined by
5483 Analyze_Selected_Component (N);
5485 end Find_Selected_Component;
5491 procedure Find_Type (N : Node_Id) is
5501 elsif Nkind (N) = N_Attribute_Reference then
5503 -- Class attribute. This is not valid in Ada 83 mode, but we do not
5504 -- need to enforce that at this point, since the declaration of the
5505 -- tagged type in the prefix would have been flagged already.
5507 if Attribute_Name (N) = Name_Class then
5508 Check_Restriction (No_Dispatch, N);
5509 Find_Type (Prefix (N));
5511 -- Propagate error from bad prefix
5513 if Etype (Prefix (N)) = Any_Type then
5514 Set_Entity (N, Any_Type);
5515 Set_Etype (N, Any_Type);
5519 T := Base_Type (Entity (Prefix (N)));
5521 -- Case where type is not known to be tagged. Its appearance in
5522 -- the prefix of the 'Class attribute indicates that the full view
5525 if not Is_Tagged_Type (T) then
5526 if Ekind (T) = E_Incomplete_Type then
5528 -- It is legal to denote the class type of an incomplete
5529 -- type. The full type will have to be tagged, of course.
5530 -- In Ada 2005 this usage is declared obsolescent, so we
5531 -- warn accordingly.
5533 -- ??? This test is temporarily disabled (always False)
5534 -- because it causes an unwanted warning on GNAT sources
5535 -- (built with -gnatg, which includes Warn_On_Obsolescent_
5536 -- Feature). Once this issue is cleared in the sources, it
5539 if not Is_Tagged_Type (T)
5540 and then Ada_Version >= Ada_05
5541 and then Warn_On_Obsolescent_Feature
5545 ("applying 'Class to an untagged incomplete type"
5546 & " is an obsolescent feature (RM J.11)", N);
5549 Set_Is_Tagged_Type (T);
5550 Set_Primitive_Operations (T, New_Elmt_List);
5551 Make_Class_Wide_Type (T);
5552 Set_Entity (N, Class_Wide_Type (T));
5553 Set_Etype (N, Class_Wide_Type (T));
5555 elsif Ekind (T) = E_Private_Type
5556 and then not Is_Generic_Type (T)
5557 and then In_Private_Part (Scope (T))
5559 -- The Class attribute can be applied to an untagged private
5560 -- type fulfilled by a tagged type prior to the full type
5561 -- declaration (but only within the parent package's private
5562 -- part). Create the class-wide type now and check that the
5563 -- full type is tagged later during its analysis. Note that
5564 -- we do not mark the private type as tagged, unlike the
5565 -- case of incomplete types, because the type must still
5566 -- appear untagged to outside units.
5568 if No (Class_Wide_Type (T)) then
5569 Make_Class_Wide_Type (T);
5572 Set_Entity (N, Class_Wide_Type (T));
5573 Set_Etype (N, Class_Wide_Type (T));
5576 -- Should we introduce a type Any_Tagged and use Wrong_Type
5577 -- here, it would be a bit more consistent???
5580 ("tagged type required, found}",
5581 Prefix (N), First_Subtype (T));
5582 Set_Entity (N, Any_Type);
5586 -- Case of tagged type
5589 if Is_Concurrent_Type (T) then
5590 if No (Corresponding_Record_Type (Entity (Prefix (N)))) then
5592 -- Previous error. Use current type, which at least
5593 -- provides some operations.
5595 C := Entity (Prefix (N));
5598 C := Class_Wide_Type
5599 (Corresponding_Record_Type (Entity (Prefix (N))));
5603 C := Class_Wide_Type (Entity (Prefix (N)));
5606 Set_Entity_With_Style_Check (N, C);
5607 Generate_Reference (C, N);
5611 -- Base attribute, not allowed in Ada 83
5613 elsif Attribute_Name (N) = Name_Base then
5614 if Ada_Version = Ada_83 and then Comes_From_Source (N) then
5616 ("(Ada 83) Base attribute not allowed in subtype mark", N);
5619 Find_Type (Prefix (N));
5620 Typ := Entity (Prefix (N));
5622 if Ada_Version >= Ada_95
5623 and then not Is_Scalar_Type (Typ)
5624 and then not Is_Generic_Type (Typ)
5627 ("prefix of Base attribute must be scalar type",
5630 elsif Sloc (Typ) = Standard_Location
5631 and then Base_Type (Typ) = Typ
5632 and then Warn_On_Redundant_Constructs
5635 ("?redundant attribute, & is its own base type", N, Typ);
5638 T := Base_Type (Typ);
5640 -- Rewrite attribute reference with type itself (see similar
5641 -- processing in Analyze_Attribute, case Base). Preserve
5642 -- prefix if present, for other legality checks.
5644 if Nkind (Prefix (N)) = N_Expanded_Name then
5646 Make_Expanded_Name (Sloc (N),
5648 Prefix => New_Copy (Prefix (Prefix (N))),
5649 Selector_Name => New_Reference_To (T, Sloc (N))));
5652 Rewrite (N, New_Reference_To (T, Sloc (N)));
5659 elsif Attribute_Name (N) = Name_Stub_Type then
5661 -- This is handled in Analyze_Attribute
5665 -- All other attributes are invalid in a subtype mark
5668 Error_Msg_N ("invalid attribute in subtype mark", N);
5674 if Is_Entity_Name (N) then
5675 T_Name := Entity (N);
5677 Error_Msg_N ("subtype mark required in this context", N);
5678 Set_Etype (N, Any_Type);
5682 if T_Name = Any_Id or else Etype (N) = Any_Type then
5684 -- Undefined id. Make it into a valid type
5686 Set_Entity (N, Any_Type);
5688 elsif not Is_Type (T_Name)
5689 and then T_Name /= Standard_Void_Type
5691 Error_Msg_Sloc := Sloc (T_Name);
5692 Error_Msg_N ("subtype mark required in this context", N);
5693 Error_Msg_NE ("\\found & declared#", N, T_Name);
5694 Set_Entity (N, Any_Type);
5697 -- If the type is an incomplete type created to handle
5698 -- anonymous access components of a record type, then the
5699 -- incomplete type is the visible entity and subsequent
5700 -- references will point to it. Mark the original full
5701 -- type as referenced, to prevent spurious warnings.
5703 if Is_Incomplete_Type (T_Name)
5704 and then Present (Full_View (T_Name))
5705 and then not Comes_From_Source (T_Name)
5707 Set_Referenced (Full_View (T_Name));
5710 T_Name := Get_Full_View (T_Name);
5712 -- Ada 2005 (AI-251, AI-50217): Handle interfaces visible through
5713 -- limited-with clauses
5715 if From_With_Type (T_Name)
5716 and then Ekind (T_Name) in Incomplete_Kind
5717 and then Present (Non_Limited_View (T_Name))
5718 and then Is_Interface (Non_Limited_View (T_Name))
5720 T_Name := Non_Limited_View (T_Name);
5723 if In_Open_Scopes (T_Name) then
5724 if Ekind (Base_Type (T_Name)) = E_Task_Type then
5726 -- In Ada 2005, a task name can be used in an access
5727 -- definition within its own body. It cannot be used
5728 -- in the discriminant part of the task declaration,
5729 -- nor anywhere else in the declaration because entries
5730 -- cannot have access parameters.
5732 if Ada_Version >= Ada_05
5733 and then Nkind (Parent (N)) = N_Access_Definition
5735 Set_Entity (N, T_Name);
5736 Set_Etype (N, T_Name);
5738 if Has_Completion (T_Name) then
5743 ("task type cannot be used as type mark " &
5744 "within its own declaration", N);
5749 ("task type cannot be used as type mark " &
5750 "within its own spec or body", N);
5753 elsif Ekind (Base_Type (T_Name)) = E_Protected_Type then
5755 -- In Ada 2005, a protected name can be used in an access
5756 -- definition within its own body.
5758 if Ada_Version >= Ada_05
5759 and then Nkind (Parent (N)) = N_Access_Definition
5761 Set_Entity (N, T_Name);
5762 Set_Etype (N, T_Name);
5767 ("protected type cannot be used as type mark " &
5768 "within its own spec or body", N);
5772 Error_Msg_N ("type declaration cannot refer to itself", N);
5775 Set_Etype (N, Any_Type);
5776 Set_Entity (N, Any_Type);
5777 Set_Error_Posted (T_Name);
5781 Set_Entity (N, T_Name);
5782 Set_Etype (N, T_Name);
5786 if Present (Etype (N)) and then Comes_From_Source (N) then
5787 if Is_Fixed_Point_Type (Etype (N)) then
5788 Check_Restriction (No_Fixed_Point, N);
5789 elsif Is_Floating_Point_Type (Etype (N)) then
5790 Check_Restriction (No_Floating_Point, N);
5795 ------------------------------------
5796 -- Has_Implicit_Character_Literal --
5797 ------------------------------------
5799 function Has_Implicit_Character_Literal (N : Node_Id) return Boolean is
5801 Found : Boolean := False;
5802 P : constant Entity_Id := Entity (Prefix (N));
5803 Priv_Id : Entity_Id := Empty;
5806 if Ekind (P) = E_Package
5807 and then not In_Open_Scopes (P)
5809 Priv_Id := First_Private_Entity (P);
5812 if P = Standard_Standard then
5813 Change_Selected_Component_To_Expanded_Name (N);
5814 Rewrite (N, Selector_Name (N));
5816 Set_Etype (Original_Node (N), Standard_Character);
5820 Id := First_Entity (P);
5822 and then Id /= Priv_Id
5824 if Is_Standard_Character_Type (Id)
5825 and then Id = Base_Type (Id)
5827 -- We replace the node with the literal itself, resolve as a
5828 -- character, and set the type correctly.
5831 Change_Selected_Component_To_Expanded_Name (N);
5832 Rewrite (N, Selector_Name (N));
5835 Set_Etype (Original_Node (N), Id);
5839 -- More than one type derived from Character in given scope.
5840 -- Collect all possible interpretations.
5842 Add_One_Interp (N, Id, Id);
5850 end Has_Implicit_Character_Literal;
5852 ----------------------
5853 -- Has_Private_With --
5854 ----------------------
5856 function Has_Private_With (E : Entity_Id) return Boolean is
5857 Comp_Unit : constant Node_Id := Cunit (Current_Sem_Unit);
5861 Item := First (Context_Items (Comp_Unit));
5862 while Present (Item) loop
5863 if Nkind (Item) = N_With_Clause
5864 and then Private_Present (Item)
5865 and then Entity (Name (Item)) = E
5874 end Has_Private_With;
5876 ---------------------------
5877 -- Has_Implicit_Operator --
5878 ---------------------------
5880 function Has_Implicit_Operator (N : Node_Id) return Boolean is
5881 Op_Id : constant Name_Id := Chars (Selector_Name (N));
5882 P : constant Entity_Id := Entity (Prefix (N));
5884 Priv_Id : Entity_Id := Empty;
5886 procedure Add_Implicit_Operator
5888 Op_Type : Entity_Id := Empty);
5889 -- Add implicit interpretation to node N, using the type for which a
5890 -- predefined operator exists. If the operator yields a boolean type,
5891 -- the Operand_Type is implicitly referenced by the operator, and a
5892 -- reference to it must be generated.
5894 ---------------------------
5895 -- Add_Implicit_Operator --
5896 ---------------------------
5898 procedure Add_Implicit_Operator
5900 Op_Type : Entity_Id := Empty)
5902 Predef_Op : Entity_Id;
5905 Predef_Op := Current_Entity (Selector_Name (N));
5907 while Present (Predef_Op)
5908 and then Scope (Predef_Op) /= Standard_Standard
5910 Predef_Op := Homonym (Predef_Op);
5913 if Nkind (N) = N_Selected_Component then
5914 Change_Selected_Component_To_Expanded_Name (N);
5917 Add_One_Interp (N, Predef_Op, T);
5919 -- For operators with unary and binary interpretations, add both
5921 if Present (Homonym (Predef_Op)) then
5922 Add_One_Interp (N, Homonym (Predef_Op), T);
5925 -- The node is a reference to a predefined operator, and
5926 -- an implicit reference to the type of its operands.
5928 if Present (Op_Type) then
5929 Generate_Operator_Reference (N, Op_Type);
5931 Generate_Operator_Reference (N, T);
5933 end Add_Implicit_Operator;
5935 -- Start of processing for Has_Implicit_Operator
5938 if Ekind (P) = E_Package
5939 and then not In_Open_Scopes (P)
5941 Priv_Id := First_Private_Entity (P);
5944 Id := First_Entity (P);
5948 -- Boolean operators: an implicit declaration exists if the scope
5949 -- contains a declaration for a derived Boolean type, or for an
5950 -- array of Boolean type.
5952 when Name_Op_And | Name_Op_Not | Name_Op_Or | Name_Op_Xor =>
5953 while Id /= Priv_Id loop
5954 if Valid_Boolean_Arg (Id)
5955 and then Id = Base_Type (Id)
5957 Add_Implicit_Operator (Id);
5964 -- Equality: look for any non-limited type (result is Boolean)
5966 when Name_Op_Eq | Name_Op_Ne =>
5967 while Id /= Priv_Id loop
5969 and then not Is_Limited_Type (Id)
5970 and then Id = Base_Type (Id)
5972 Add_Implicit_Operator (Standard_Boolean, Id);
5979 -- Comparison operators: scalar type, or array of scalar
5981 when Name_Op_Lt | Name_Op_Le | Name_Op_Gt | Name_Op_Ge =>
5982 while Id /= Priv_Id loop
5983 if (Is_Scalar_Type (Id)
5984 or else (Is_Array_Type (Id)
5985 and then Is_Scalar_Type (Component_Type (Id))))
5986 and then Id = Base_Type (Id)
5988 Add_Implicit_Operator (Standard_Boolean, Id);
5995 -- Arithmetic operators: any numeric type
6005 while Id /= Priv_Id loop
6006 if Is_Numeric_Type (Id)
6007 and then Id = Base_Type (Id)
6009 Add_Implicit_Operator (Id);
6016 -- Concatenation: any one-dimensional array type
6018 when Name_Op_Concat =>
6019 while Id /= Priv_Id loop
6020 if Is_Array_Type (Id) and then Number_Dimensions (Id) = 1
6021 and then Id = Base_Type (Id)
6023 Add_Implicit_Operator (Id);
6030 -- What is the others condition here? Should we be using a
6031 -- subtype of Name_Id that would restrict to operators ???
6033 when others => null;
6036 -- If we fall through, then we do not have an implicit operator
6040 end Has_Implicit_Operator;
6042 --------------------
6043 -- In_Open_Scopes --
6044 --------------------
6046 function In_Open_Scopes (S : Entity_Id) return Boolean is
6048 -- Several scope stacks are maintained by Scope_Stack. The base of the
6049 -- currently active scope stack is denoted by the Is_Active_Stack_Base
6050 -- flag in the scope stack entry. Note that the scope stacks used to
6051 -- simply be delimited implicitly by the presence of Standard_Standard
6052 -- at their base, but there now are cases where this is not sufficient
6053 -- because Standard_Standard actually may appear in the middle of the
6054 -- active set of scopes.
6056 for J in reverse 0 .. Scope_Stack.Last loop
6057 if Scope_Stack.Table (J).Entity = S then
6061 -- Check Is_Active_Stack_Base to tell us when to stop, as there are
6062 -- cases where Standard_Standard appears in the middle of the active
6063 -- set of scopes. This affects the declaration and overriding of
6064 -- private inherited operations in instantiations of generic child
6067 exit when Scope_Stack.Table (J).Is_Active_Stack_Base;
6073 -----------------------------
6074 -- Inherit_Renamed_Profile --
6075 -----------------------------
6077 procedure Inherit_Renamed_Profile (New_S : Entity_Id; Old_S : Entity_Id) is
6084 if Ekind (Old_S) = E_Operator then
6085 New_F := First_Formal (New_S);
6087 while Present (New_F) loop
6088 Set_Etype (New_F, Base_Type (Etype (New_F)));
6089 Next_Formal (New_F);
6092 Set_Etype (New_S, Base_Type (Etype (New_S)));
6095 New_F := First_Formal (New_S);
6096 Old_F := First_Formal (Old_S);
6098 while Present (New_F) loop
6099 New_T := Etype (New_F);
6100 Old_T := Etype (Old_F);
6102 -- If the new type is a renaming of the old one, as is the
6103 -- case for actuals in instances, retain its name, to simplify
6104 -- later disambiguation.
6106 if Nkind (Parent (New_T)) = N_Subtype_Declaration
6107 and then Is_Entity_Name (Subtype_Indication (Parent (New_T)))
6108 and then Entity (Subtype_Indication (Parent (New_T))) = Old_T
6112 Set_Etype (New_F, Old_T);
6115 Next_Formal (New_F);
6116 Next_Formal (Old_F);
6119 if Ekind (Old_S) = E_Function
6120 or else Ekind (Old_S) = E_Enumeration_Literal
6122 Set_Etype (New_S, Etype (Old_S));
6125 end Inherit_Renamed_Profile;
6131 procedure Initialize is
6136 -------------------------
6137 -- Install_Use_Clauses --
6138 -------------------------
6140 procedure Install_Use_Clauses
6142 Force_Installation : Boolean := False)
6150 while Present (U) loop
6152 -- Case of USE package
6154 if Nkind (U) = N_Use_Package_Clause then
6155 P := First (Names (U));
6156 while Present (P) loop
6159 if Ekind (Id) = E_Package then
6161 Note_Redundant_Use (P);
6163 elsif Present (Renamed_Object (Id))
6164 and then In_Use (Renamed_Object (Id))
6166 Note_Redundant_Use (P);
6168 elsif Force_Installation or else Applicable_Use (P) then
6169 Use_One_Package (Id, U);
6180 P := First (Subtype_Marks (U));
6181 while Present (P) loop
6182 if not Is_Entity_Name (P)
6183 or else No (Entity (P))
6187 elsif Entity (P) /= Any_Type then
6195 Next_Use_Clause (U);
6197 end Install_Use_Clauses;
6199 -------------------------------------
6200 -- Is_Appropriate_For_Entry_Prefix --
6201 -------------------------------------
6203 function Is_Appropriate_For_Entry_Prefix (T : Entity_Id) return Boolean is
6204 P_Type : Entity_Id := T;
6207 if Is_Access_Type (P_Type) then
6208 P_Type := Designated_Type (P_Type);
6211 return Is_Task_Type (P_Type) or else Is_Protected_Type (P_Type);
6212 end Is_Appropriate_For_Entry_Prefix;
6214 -------------------------------
6215 -- Is_Appropriate_For_Record --
6216 -------------------------------
6218 function Is_Appropriate_For_Record (T : Entity_Id) return Boolean is
6220 function Has_Components (T1 : Entity_Id) return Boolean;
6221 -- Determine if given type has components (i.e. is either a record
6222 -- type or a type that has discriminants).
6224 --------------------
6225 -- Has_Components --
6226 --------------------
6228 function Has_Components (T1 : Entity_Id) return Boolean is
6230 return Is_Record_Type (T1)
6231 or else (Is_Private_Type (T1) and then Has_Discriminants (T1))
6232 or else (Is_Task_Type (T1) and then Has_Discriminants (T1))
6233 or else (Is_Incomplete_Type (T1)
6234 and then From_With_Type (T1)
6235 and then Present (Non_Limited_View (T1))
6236 and then Is_Record_Type
6237 (Get_Full_View (Non_Limited_View (T1))));
6240 -- Start of processing for Is_Appropriate_For_Record
6245 and then (Has_Components (T)
6246 or else (Is_Access_Type (T)
6247 and then Has_Components (Designated_Type (T))));
6248 end Is_Appropriate_For_Record;
6250 ------------------------
6251 -- Note_Redundant_Use --
6252 ------------------------
6254 procedure Note_Redundant_Use (Clause : Node_Id) is
6255 Pack_Name : constant Entity_Id := Entity (Clause);
6256 Cur_Use : constant Node_Id := Current_Use_Clause (Pack_Name);
6257 Decl : constant Node_Id := Parent (Clause);
6259 Prev_Use : Node_Id := Empty;
6260 Redundant : Node_Id := Empty;
6261 -- The Use_Clause which is actually redundant. In the simplest case it
6262 -- is Pack itself, but when we compile a body we install its context
6263 -- before that of its spec, in which case it is the use_clause in the
6264 -- spec that will appear to be redundant, and we want the warning to be
6265 -- placed on the body. Similar complications appear when the redundancy
6266 -- is between a child unit and one of its ancestors.
6269 Set_Redundant_Use (Clause, True);
6271 if not Comes_From_Source (Clause)
6273 or else not Warn_On_Redundant_Constructs
6278 if not Is_Compilation_Unit (Current_Scope) then
6280 -- If the use_clause is in an inner scope, it is made redundant by
6281 -- some clause in the current context, with one exception: If we're
6282 -- compiling a nested package body, and the use_clause comes from the
6283 -- corresponding spec, the clause is not necessarily fully redundant,
6284 -- so we should not warn. If a warning was warranted, it would have
6285 -- been given when the spec was processed.
6287 if Nkind (Parent (Decl)) = N_Package_Specification then
6289 Package_Spec_Entity : constant Entity_Id :=
6290 Defining_Unit_Name (Parent (Decl));
6292 if In_Package_Body (Package_Spec_Entity) then
6298 Redundant := Clause;
6299 Prev_Use := Cur_Use;
6301 elsif Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Body then
6303 Cur_Unit : constant Unit_Number_Type := Get_Source_Unit (Cur_Use);
6304 New_Unit : constant Unit_Number_Type := Get_Source_Unit (Clause);
6308 if Cur_Unit = New_Unit then
6310 -- Redundant clause in same body
6312 Redundant := Clause;
6313 Prev_Use := Cur_Use;
6315 elsif Cur_Unit = Current_Sem_Unit then
6317 -- If the new clause is not in the current unit it has been
6318 -- analyzed first, and it makes the other one redundant.
6319 -- However, if the new clause appears in a subunit, Cur_Unit
6320 -- is still the parent, and in that case the redundant one
6321 -- is the one appearing in the subunit.
6323 if Nkind (Unit (Cunit (New_Unit))) = N_Subunit then
6324 Redundant := Clause;
6325 Prev_Use := Cur_Use;
6327 -- Most common case: redundant clause in body,
6328 -- original clause in spec. Current scope is spec entity.
6333 Unit (Library_Unit (Cunit (Current_Sem_Unit))))
6335 Redundant := Cur_Use;
6339 -- The new clause may appear in an unrelated unit, when
6340 -- the parents of a generic are being installed prior to
6341 -- instantiation. In this case there must be no warning.
6342 -- We detect this case by checking whether the current top
6343 -- of the stack is related to the current compilation.
6345 Scop := Current_Scope;
6346 while Present (Scop)
6347 and then Scop /= Standard_Standard
6349 if Is_Compilation_Unit (Scop)
6350 and then not Is_Child_Unit (Scop)
6354 elsif Scop = Cunit_Entity (Current_Sem_Unit) then
6358 Scop := Scope (Scop);
6361 Redundant := Cur_Use;
6365 elsif New_Unit = Current_Sem_Unit then
6366 Redundant := Clause;
6367 Prev_Use := Cur_Use;
6370 -- Neither is the current unit, so they appear in parent or
6371 -- sibling units. Warning will be emitted elsewhere.
6377 elsif Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Declaration
6378 and then Present (Parent_Spec (Unit (Cunit (Current_Sem_Unit))))
6380 -- Use_clause is in child unit of current unit, and the child unit
6381 -- appears in the context of the body of the parent, so it has been
6382 -- installed first, even though it is the redundant one. Depending on
6383 -- their placement in the context, the visible or the private parts
6384 -- of the two units, either might appear as redundant, but the
6385 -- message has to be on the current unit.
6387 if Get_Source_Unit (Cur_Use) = Current_Sem_Unit then
6388 Redundant := Cur_Use;
6391 Redundant := Clause;
6392 Prev_Use := Cur_Use;
6395 -- If the new use clause appears in the private part of a parent unit
6396 -- it may appear to be redundant w.r.t. a use clause in a child unit,
6397 -- but the previous use clause was needed in the visible part of the
6398 -- child, and no warning should be emitted.
6400 if Nkind (Parent (Decl)) = N_Package_Specification
6402 List_Containing (Decl) = Private_Declarations (Parent (Decl))
6405 Par : constant Entity_Id := Defining_Entity (Parent (Decl));
6406 Spec : constant Node_Id :=
6407 Specification (Unit (Cunit (Current_Sem_Unit)));
6410 if Is_Compilation_Unit (Par)
6411 and then Par /= Cunit_Entity (Current_Sem_Unit)
6412 and then Parent (Cur_Use) = Spec
6414 List_Containing (Cur_Use) = Visible_Declarations (Spec)
6421 -- Finally, if the current use clause is in the context then
6422 -- the clause is redundant when it is nested within the unit.
6424 elsif Nkind (Parent (Cur_Use)) = N_Compilation_Unit
6425 and then Nkind (Parent (Parent (Clause))) /= N_Compilation_Unit
6426 and then Get_Source_Unit (Cur_Use) = Get_Source_Unit (Clause)
6428 Redundant := Clause;
6429 Prev_Use := Cur_Use;
6435 if Present (Redundant) then
6436 Error_Msg_Sloc := Sloc (Prev_Use);
6438 ("& is already use-visible through previous use clause #?",
6439 Redundant, Pack_Name);
6441 end Note_Redundant_Use;
6447 procedure Pop_Scope is
6448 SST : Scope_Stack_Entry renames Scope_Stack.Table (Scope_Stack.Last);
6451 if Debug_Flag_E then
6455 Scope_Suppress := SST.Save_Scope_Suppress;
6456 Local_Suppress_Stack_Top := SST.Save_Local_Suppress_Stack_Top;
6457 Check_Policy_List := SST.Save_Check_Policy_List;
6459 if Debug_Flag_W then
6460 Write_Str ("--> exiting scope: ");
6461 Write_Name (Chars (Current_Scope));
6462 Write_Str (", Depth=");
6463 Write_Int (Int (Scope_Stack.Last));
6467 End_Use_Clauses (SST.First_Use_Clause);
6469 -- If the actions to be wrapped are still there they will get lost
6470 -- causing incomplete code to be generated. It is better to abort in
6471 -- this case (and we do the abort even with assertions off since the
6472 -- penalty is incorrect code generation)
6474 if SST.Actions_To_Be_Wrapped_Before /= No_List
6476 SST.Actions_To_Be_Wrapped_After /= No_List
6481 -- Free last subprogram name if allocated, and pop scope
6483 Free (SST.Last_Subprogram_Name);
6484 Scope_Stack.Decrement_Last;
6491 procedure Push_Scope (S : Entity_Id) is
6495 if Ekind (S) = E_Void then
6498 -- Set scope depth if not a non-concurrent type, and we have not yet set
6499 -- the scope depth. This means that we have the first occurrence of the
6500 -- scope, and this is where the depth is set.
6502 elsif (not Is_Type (S) or else Is_Concurrent_Type (S))
6503 and then not Scope_Depth_Set (S)
6505 if S = Standard_Standard then
6506 Set_Scope_Depth_Value (S, Uint_0);
6508 elsif Is_Child_Unit (S) then
6509 Set_Scope_Depth_Value (S, Uint_1);
6511 elsif not Is_Record_Type (Current_Scope) then
6512 if Ekind (S) = E_Loop then
6513 Set_Scope_Depth_Value (S, Scope_Depth (Current_Scope));
6515 Set_Scope_Depth_Value (S, Scope_Depth (Current_Scope) + 1);
6520 Scope_Stack.Increment_Last;
6523 SST : Scope_Stack_Entry renames Scope_Stack.Table (Scope_Stack.Last);
6527 SST.Save_Scope_Suppress := Scope_Suppress;
6528 SST.Save_Local_Suppress_Stack_Top := Local_Suppress_Stack_Top;
6529 SST.Save_Check_Policy_List := Check_Policy_List;
6531 if Scope_Stack.Last > Scope_Stack.First then
6532 SST.Component_Alignment_Default := Scope_Stack.Table
6533 (Scope_Stack.Last - 1).
6534 Component_Alignment_Default;
6537 SST.Last_Subprogram_Name := null;
6538 SST.Is_Transient := False;
6539 SST.Node_To_Be_Wrapped := Empty;
6540 SST.Pending_Freeze_Actions := No_List;
6541 SST.Actions_To_Be_Wrapped_Before := No_List;
6542 SST.Actions_To_Be_Wrapped_After := No_List;
6543 SST.First_Use_Clause := Empty;
6544 SST.Is_Active_Stack_Base := False;
6545 SST.Previous_Visibility := False;
6548 if Debug_Flag_W then
6549 Write_Str ("--> new scope: ");
6550 Write_Name (Chars (Current_Scope));
6551 Write_Str (", Id=");
6552 Write_Int (Int (Current_Scope));
6553 Write_Str (", Depth=");
6554 Write_Int (Int (Scope_Stack.Last));
6558 -- Deal with copying flags from the previous scope to this one. This is
6559 -- not necessary if either scope is standard, or if the new scope is a
6562 if S /= Standard_Standard
6563 and then Scope (S) /= Standard_Standard
6564 and then not Is_Child_Unit (S)
6568 if Nkind (E) not in N_Entity then
6572 -- Copy categorization flags from Scope (S) to S, this is not done
6573 -- when Scope (S) is Standard_Standard since propagation is from
6574 -- library unit entity inwards. Copy other relevant attributes as
6575 -- well (Discard_Names in particular).
6577 -- We only propagate inwards for library level entities,
6578 -- inner level subprograms do not inherit the categorization.
6580 if Is_Library_Level_Entity (S) then
6581 Set_Is_Preelaborated (S, Is_Preelaborated (E));
6582 Set_Is_Shared_Passive (S, Is_Shared_Passive (E));
6583 Set_Discard_Names (S, Discard_Names (E));
6584 Set_Suppress_Value_Tracking_On_Call
6585 (S, Suppress_Value_Tracking_On_Call (E));
6586 Set_Categorization_From_Scope (E => S, Scop => E);
6591 ---------------------
6592 -- Premature_Usage --
6593 ---------------------
6595 procedure Premature_Usage (N : Node_Id) is
6596 Kind : constant Node_Kind := Nkind (Parent (Entity (N)));
6597 E : Entity_Id := Entity (N);
6600 -- Within an instance, the analysis of the actual for a formal object
6601 -- does not see the name of the object itself. This is significant only
6602 -- if the object is an aggregate, where its analysis does not do any
6603 -- name resolution on component associations. (see 4717-008). In such a
6604 -- case, look for the visible homonym on the chain.
6607 and then Present (Homonym (E))
6612 and then not In_Open_Scopes (Scope (E))
6619 Set_Etype (N, Etype (E));
6624 if Kind = N_Component_Declaration then
6626 ("component&! cannot be used before end of record declaration", N);
6628 elsif Kind = N_Parameter_Specification then
6630 ("formal parameter&! cannot be used before end of specification",
6633 elsif Kind = N_Discriminant_Specification then
6635 ("discriminant&! cannot be used before end of discriminant part",
6638 elsif Kind = N_Procedure_Specification
6639 or else Kind = N_Function_Specification
6642 ("subprogram&! cannot be used before end of its declaration",
6645 elsif Kind = N_Full_Type_Declaration then
6647 ("type& cannot be used before end of its declaration!", N);
6651 ("object& cannot be used before end of its declaration!", N);
6653 end Premature_Usage;
6655 ------------------------
6656 -- Present_System_Aux --
6657 ------------------------
6659 function Present_System_Aux (N : Node_Id := Empty) return Boolean is
6661 Aux_Name : Unit_Name_Type;
6662 Unum : Unit_Number_Type;
6667 function Find_System (C_Unit : Node_Id) return Entity_Id;
6668 -- Scan context clause of compilation unit to find with_clause
6675 function Find_System (C_Unit : Node_Id) return Entity_Id is
6676 With_Clause : Node_Id;
6679 With_Clause := First (Context_Items (C_Unit));
6680 while Present (With_Clause) loop
6681 if (Nkind (With_Clause) = N_With_Clause
6682 and then Chars (Name (With_Clause)) = Name_System)
6683 and then Comes_From_Source (With_Clause)
6694 -- Start of processing for Present_System_Aux
6697 -- The child unit may have been loaded and analyzed already
6699 if Present (System_Aux_Id) then
6702 -- If no previous pragma for System.Aux, nothing to load
6704 elsif No (System_Extend_Unit) then
6707 -- Use the unit name given in the pragma to retrieve the unit.
6708 -- Verify that System itself appears in the context clause of the
6709 -- current compilation. If System is not present, an error will
6710 -- have been reported already.
6713 With_Sys := Find_System (Cunit (Current_Sem_Unit));
6715 The_Unit := Unit (Cunit (Current_Sem_Unit));
6719 (Nkind (The_Unit) = N_Package_Body
6720 or else (Nkind (The_Unit) = N_Subprogram_Body
6722 not Acts_As_Spec (Cunit (Current_Sem_Unit))))
6724 With_Sys := Find_System (Library_Unit (Cunit (Current_Sem_Unit)));
6728 and then Present (N)
6730 -- If we are compiling a subunit, we need to examine its
6731 -- context as well (Current_Sem_Unit is the parent unit);
6733 The_Unit := Parent (N);
6734 while Nkind (The_Unit) /= N_Compilation_Unit loop
6735 The_Unit := Parent (The_Unit);
6738 if Nkind (Unit (The_Unit)) = N_Subunit then
6739 With_Sys := Find_System (The_Unit);
6743 if No (With_Sys) then
6747 Loc := Sloc (With_Sys);
6748 Get_Name_String (Chars (Expression (System_Extend_Unit)));
6749 Name_Buffer (8 .. Name_Len + 7) := Name_Buffer (1 .. Name_Len);
6750 Name_Buffer (1 .. 7) := "system.";
6751 Name_Buffer (Name_Len + 8) := '%';
6752 Name_Buffer (Name_Len + 9) := 's';
6753 Name_Len := Name_Len + 9;
6754 Aux_Name := Name_Find;
6758 (Load_Name => Aux_Name,
6761 Error_Node => With_Sys);
6763 if Unum /= No_Unit then
6764 Semantics (Cunit (Unum));
6766 Defining_Entity (Specification (Unit (Cunit (Unum))));
6769 Make_With_Clause (Loc,
6771 Make_Expanded_Name (Loc,
6772 Chars => Chars (System_Aux_Id),
6773 Prefix => New_Reference_To (Scope (System_Aux_Id), Loc),
6774 Selector_Name => New_Reference_To (System_Aux_Id, Loc)));
6776 Set_Entity (Name (Withn), System_Aux_Id);
6778 Set_Library_Unit (Withn, Cunit (Unum));
6779 Set_Corresponding_Spec (Withn, System_Aux_Id);
6780 Set_First_Name (Withn, True);
6781 Set_Implicit_With (Withn, True);
6783 Insert_After (With_Sys, Withn);
6784 Mark_Rewrite_Insertion (Withn);
6785 Set_Context_Installed (Withn);
6789 -- Here if unit load failed
6792 Error_Msg_Name_1 := Name_System;
6793 Error_Msg_Name_2 := Chars (Expression (System_Extend_Unit));
6795 ("extension package `%.%` does not exist",
6796 Opt.System_Extend_Unit);
6800 end Present_System_Aux;
6802 -------------------------
6803 -- Restore_Scope_Stack --
6804 -------------------------
6806 procedure Restore_Scope_Stack (Handle_Use : Boolean := True) is
6809 Comp_Unit : Node_Id;
6810 In_Child : Boolean := False;
6811 Full_Vis : Boolean := True;
6812 SS_Last : constant Int := Scope_Stack.Last;
6815 -- Restore visibility of previous scope stack, if any
6817 for J in reverse 0 .. Scope_Stack.Last loop
6818 exit when Scope_Stack.Table (J).Entity = Standard_Standard
6819 or else No (Scope_Stack.Table (J).Entity);
6821 S := Scope_Stack.Table (J).Entity;
6823 if not Is_Hidden_Open_Scope (S) then
6825 -- If the parent scope is hidden, its entities are hidden as
6826 -- well, unless the entity is the instantiation currently
6829 if not Is_Hidden_Open_Scope (Scope (S))
6830 or else not Analyzed (Parent (S))
6831 or else Scope (S) = Standard_Standard
6833 Set_Is_Immediately_Visible (S, True);
6836 E := First_Entity (S);
6837 while Present (E) loop
6838 if Is_Child_Unit (E) then
6839 if not From_With_Type (E) then
6840 Set_Is_Immediately_Visible (E,
6841 Is_Visible_Child_Unit (E) or else In_Open_Scopes (E));
6845 (Nkind (Parent (E)) = N_Defining_Program_Unit_Name
6847 Nkind (Parent (Parent (E))) = N_Package_Specification);
6848 Set_Is_Immediately_Visible (E,
6849 Limited_View_Installed (Parent (Parent (E))));
6852 Set_Is_Immediately_Visible (E, True);
6858 and then Is_Package_Or_Generic_Package (S)
6860 -- We are in the visible part of the package scope
6862 exit when E = First_Private_Entity (S);
6866 -- The visibility of child units (siblings of current compilation)
6867 -- must be restored in any case. Their declarations may appear
6868 -- after the private part of the parent.
6870 if not Full_Vis then
6871 while Present (E) loop
6872 if Is_Child_Unit (E) then
6873 Set_Is_Immediately_Visible (E,
6874 Is_Visible_Child_Unit (E) or else In_Open_Scopes (E));
6882 if Is_Child_Unit (S)
6883 and not In_Child -- check only for current unit
6887 -- Restore visibility of parents according to whether the child
6888 -- is private and whether we are in its visible part.
6890 Comp_Unit := Parent (Unit_Declaration_Node (S));
6892 if Nkind (Comp_Unit) = N_Compilation_Unit
6893 and then Private_Present (Comp_Unit)
6897 elsif Is_Package_Or_Generic_Package (S)
6898 and then (In_Private_Part (S) or else In_Package_Body (S))
6902 -- if S is the scope of some instance (which has already been
6903 -- seen on the stack) it does not affect the visibility of
6906 elsif Is_Hidden_Open_Scope (S) then
6909 elsif (Ekind (S) = E_Procedure
6910 or else Ekind (S) = E_Function)
6911 and then Has_Completion (S)
6922 if SS_Last >= Scope_Stack.First
6923 and then Scope_Stack.Table (SS_Last).Entity /= Standard_Standard
6926 Install_Use_Clauses (Scope_Stack.Table (SS_Last).First_Use_Clause);
6928 end Restore_Scope_Stack;
6930 ----------------------
6931 -- Save_Scope_Stack --
6932 ----------------------
6934 procedure Save_Scope_Stack (Handle_Use : Boolean := True) is
6937 SS_Last : constant Int := Scope_Stack.Last;
6940 if SS_Last >= Scope_Stack.First
6941 and then Scope_Stack.Table (SS_Last).Entity /= Standard_Standard
6944 End_Use_Clauses (Scope_Stack.Table (SS_Last).First_Use_Clause);
6947 -- If the call is from within a compilation unit, as when called from
6948 -- Rtsfind, make current entries in scope stack invisible while we
6949 -- analyze the new unit.
6951 for J in reverse 0 .. SS_Last loop
6952 exit when Scope_Stack.Table (J).Entity = Standard_Standard
6953 or else No (Scope_Stack.Table (J).Entity);
6955 S := Scope_Stack.Table (J).Entity;
6956 Set_Is_Immediately_Visible (S, False);
6958 E := First_Entity (S);
6959 while Present (E) loop
6960 Set_Is_Immediately_Visible (E, False);
6966 end Save_Scope_Stack;
6972 procedure Set_Use (L : List_Id) is
6974 Pack_Name : Node_Id;
6981 while Present (Decl) loop
6982 if Nkind (Decl) = N_Use_Package_Clause then
6983 Chain_Use_Clause (Decl);
6985 Pack_Name := First (Names (Decl));
6986 while Present (Pack_Name) loop
6987 Pack := Entity (Pack_Name);
6989 if Ekind (Pack) = E_Package
6990 and then Applicable_Use (Pack_Name)
6992 Use_One_Package (Pack, Decl);
6998 elsif Nkind (Decl) = N_Use_Type_Clause then
6999 Chain_Use_Clause (Decl);
7001 Id := First (Subtype_Marks (Decl));
7002 while Present (Id) loop
7003 if Entity (Id) /= Any_Type then
7016 ---------------------
7017 -- Use_One_Package --
7018 ---------------------
7020 procedure Use_One_Package (P : Entity_Id; N : Node_Id) is
7023 Current_Instance : Entity_Id := Empty;
7025 Private_With_OK : Boolean := False;
7028 if Ekind (P) /= E_Package then
7033 Set_Current_Use_Clause (P, N);
7035 -- Ada 2005 (AI-50217): Check restriction
7037 if From_With_Type (P) then
7038 Error_Msg_N ("limited withed package cannot appear in use clause", N);
7041 -- Find enclosing instance, if any
7044 Current_Instance := Current_Scope;
7045 while not Is_Generic_Instance (Current_Instance) loop
7046 Current_Instance := Scope (Current_Instance);
7049 if No (Hidden_By_Use_Clause (N)) then
7050 Set_Hidden_By_Use_Clause (N, New_Elmt_List);
7054 -- If unit is a package renaming, indicate that the renamed
7055 -- package is also in use (the flags on both entities must
7056 -- remain consistent, and a subsequent use of either of them
7057 -- should be recognized as redundant).
7059 if Present (Renamed_Object (P)) then
7060 Set_In_Use (Renamed_Object (P));
7061 Set_Current_Use_Clause (Renamed_Object (P), N);
7062 Real_P := Renamed_Object (P);
7067 -- Ada 2005 (AI-262): Check the use_clause of a private withed package
7068 -- found in the private part of a package specification
7070 if In_Private_Part (Current_Scope)
7071 and then Has_Private_With (P)
7072 and then Is_Child_Unit (Current_Scope)
7073 and then Is_Child_Unit (P)
7074 and then Is_Ancestor_Package (Scope (Current_Scope), P)
7076 Private_With_OK := True;
7079 -- Loop through entities in one package making them potentially
7082 Id := First_Entity (P);
7084 and then (Id /= First_Private_Entity (P)
7085 or else Private_With_OK) -- Ada 2005 (AI-262)
7087 Prev := Current_Entity (Id);
7088 while Present (Prev) loop
7089 if Is_Immediately_Visible (Prev)
7090 and then (not Is_Overloadable (Prev)
7091 or else not Is_Overloadable (Id)
7092 or else (Type_Conformant (Id, Prev)))
7094 if No (Current_Instance) then
7096 -- Potentially use-visible entity remains hidden
7098 goto Next_Usable_Entity;
7100 -- A use clause within an instance hides outer global entities,
7101 -- which are not used to resolve local entities in the
7102 -- instance. Note that the predefined entities in Standard
7103 -- could not have been hidden in the generic by a use clause,
7104 -- and therefore remain visible. Other compilation units whose
7105 -- entities appear in Standard must be hidden in an instance.
7107 -- To determine whether an entity is external to the instance
7108 -- we compare the scope depth of its scope with that of the
7109 -- current instance. However, a generic actual of a subprogram
7110 -- instance is declared in the wrapper package but will not be
7111 -- hidden by a use-visible entity.
7113 -- If Id is called Standard, the predefined package with the
7114 -- same name is in the homonym chain. It has to be ignored
7115 -- because it has no defined scope (being the only entity in
7116 -- the system with this mandated behavior).
7118 elsif not Is_Hidden (Id)
7119 and then Present (Scope (Prev))
7120 and then not Is_Wrapper_Package (Scope (Prev))
7121 and then Scope_Depth (Scope (Prev)) <
7122 Scope_Depth (Current_Instance)
7123 and then (Scope (Prev) /= Standard_Standard
7124 or else Sloc (Prev) > Standard_Location)
7126 Set_Is_Potentially_Use_Visible (Id);
7127 Set_Is_Immediately_Visible (Prev, False);
7128 Append_Elmt (Prev, Hidden_By_Use_Clause (N));
7131 -- A user-defined operator is not use-visible if the predefined
7132 -- operator for the type is immediately visible, which is the case
7133 -- if the type of the operand is in an open scope. This does not
7134 -- apply to user-defined operators that have operands of different
7135 -- types, because the predefined mixed mode operations (multiply
7136 -- and divide) apply to universal types and do not hide anything.
7138 elsif Ekind (Prev) = E_Operator
7139 and then Operator_Matches_Spec (Prev, Id)
7140 and then In_Open_Scopes
7141 (Scope (Base_Type (Etype (First_Formal (Id)))))
7142 and then (No (Next_Formal (First_Formal (Id)))
7143 or else Etype (First_Formal (Id))
7144 = Etype (Next_Formal (First_Formal (Id)))
7145 or else Chars (Prev) = Name_Op_Expon)
7147 goto Next_Usable_Entity;
7149 -- In an instance, two homonyms may become use_visible through the
7150 -- actuals of distinct formal packages. In the generic, only the
7151 -- current one would have been visible, so make the other one
7154 elsif Present (Current_Instance)
7155 and then Is_Potentially_Use_Visible (Prev)
7156 and then not Is_Overloadable (Prev)
7157 and then Scope (Id) /= Scope (Prev)
7158 and then Used_As_Generic_Actual (Scope (Prev))
7159 and then Used_As_Generic_Actual (Scope (Id))
7160 and then List_Containing (Current_Use_Clause (Scope (Prev))) /=
7161 List_Containing (Current_Use_Clause (Scope (Id)))
7163 Set_Is_Potentially_Use_Visible (Prev, False);
7164 Append_Elmt (Prev, Hidden_By_Use_Clause (N));
7167 Prev := Homonym (Prev);
7170 -- On exit, we know entity is not hidden, unless it is private
7172 if not Is_Hidden (Id)
7173 and then ((not Is_Child_Unit (Id))
7174 or else Is_Visible_Child_Unit (Id))
7176 Set_Is_Potentially_Use_Visible (Id);
7178 if Is_Private_Type (Id)
7179 and then Present (Full_View (Id))
7181 Set_Is_Potentially_Use_Visible (Full_View (Id));
7185 <<Next_Usable_Entity>>
7189 -- Child units are also made use-visible by a use clause, but they may
7190 -- appear after all visible declarations in the parent entity list.
7192 while Present (Id) loop
7193 if Is_Child_Unit (Id)
7194 and then Is_Visible_Child_Unit (Id)
7196 Set_Is_Potentially_Use_Visible (Id);
7202 if Chars (Real_P) = Name_System
7203 and then Scope (Real_P) = Standard_Standard
7204 and then Present_System_Aux (N)
7206 Use_One_Package (System_Aux_Id, N);
7209 end Use_One_Package;
7215 procedure Use_One_Type (Id : Node_Id) is
7217 Is_Known_Used : Boolean;
7221 function Spec_Reloaded_For_Body return Boolean;
7222 -- Determine whether the compilation unit is a package body and the use
7223 -- type clause is in the spec of the same package. Even though the spec
7224 -- was analyzed first, its context is reloaded when analysing the body.
7226 ----------------------------
7227 -- Spec_Reloaded_For_Body --
7228 ----------------------------
7230 function Spec_Reloaded_For_Body return Boolean is
7232 if Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Body then
7234 Spec : constant Node_Id :=
7235 Parent (List_Containing (Parent (Id)));
7238 Nkind (Spec) = N_Package_Specification
7239 and then Corresponding_Body (Parent (Spec)) =
7240 Cunit_Entity (Current_Sem_Unit);
7245 end Spec_Reloaded_For_Body;
7247 -- Start of processing for Use_One_Type;
7250 -- It is the type determined by the subtype mark (8.4(8)) whose
7251 -- operations become potentially use-visible.
7253 T := Base_Type (Entity (Id));
7255 -- Either the type itself is used, the package where it is declared
7256 -- is in use or the entity is declared in the current package, thus
7261 or else In_Use (Scope (T))
7262 or else Scope (T) = Current_Scope;
7264 Set_Redundant_Use (Id,
7265 Is_Known_Used or else Is_Potentially_Use_Visible (T));
7267 if Ekind (T) = E_Incomplete_Type then
7268 Error_Msg_N ("premature usage of incomplete type", Id);
7270 elsif In_Open_Scopes (Scope (T)) then
7273 -- A limited view cannot appear in a use_type clause. However, an access
7274 -- type whose designated type is limited has the flag but is not itself
7275 -- a limited view unless we only have a limited view of its enclosing
7278 elsif From_With_Type (T)
7279 and then From_With_Type (Scope (T))
7282 ("incomplete type from limited view "
7283 & "cannot appear in use clause", Id);
7285 -- If the subtype mark designates a subtype in a different package,
7286 -- we have to check that the parent type is visible, otherwise the
7287 -- use type clause is a noop. Not clear how to do that???
7289 elsif not Redundant_Use (Id) then
7292 -- If T is tagged, primitive operators on class-wide operands
7293 -- are also available.
7295 if Is_Tagged_Type (T) then
7296 Set_In_Use (Class_Wide_Type (T));
7299 Set_Current_Use_Clause (T, Parent (Id));
7300 Op_List := Collect_Primitive_Operations (T);
7302 Elmt := First_Elmt (Op_List);
7303 while Present (Elmt) loop
7304 if (Nkind (Node (Elmt)) = N_Defining_Operator_Symbol
7305 or else Chars (Node (Elmt)) in Any_Operator_Name)
7306 and then not Is_Hidden (Node (Elmt))
7308 Set_Is_Potentially_Use_Visible (Node (Elmt));
7315 -- If warning on redundant constructs, check for unnecessary WITH
7317 if Warn_On_Redundant_Constructs
7318 and then Is_Known_Used
7320 -- with P; with P; use P;
7321 -- package P is package X is package body X is
7322 -- type T ... use P.T;
7324 -- The compilation unit is the body of X. GNAT first compiles the
7325 -- spec of X, then proceeds to the body. At that point P is marked
7326 -- as use visible. The analysis then reinstalls the spec along with
7327 -- its context. The use clause P.T is now recognized as redundant,
7328 -- but in the wrong context. Do not emit a warning in such cases.
7329 -- Do not emit a warning either if we are in an instance, there is
7330 -- no redundancy between an outer use_clause and one that appears
7331 -- within the generic.
7333 and then not Spec_Reloaded_For_Body
7334 and then not In_Instance
7336 -- The type already has a use clause
7340 -- Case where we know the current use clause for the type
7342 if Present (Current_Use_Clause (T)) then
7343 Use_Clause_Known : declare
7344 Clause1 : constant Node_Id := Parent (Id);
7345 Clause2 : constant Node_Id := Current_Use_Clause (T);
7352 function Entity_Of_Unit (U : Node_Id) return Entity_Id;
7353 -- Return the appropriate entity for determining which unit
7354 -- has a deeper scope: the defining entity for U, unless U
7355 -- is a package instance, in which case we retrieve the
7356 -- entity of the instance spec.
7358 --------------------
7359 -- Entity_Of_Unit --
7360 --------------------
7362 function Entity_Of_Unit (U : Node_Id) return Entity_Id is
7364 if Nkind (U) = N_Package_Instantiation
7365 and then Analyzed (U)
7367 return Defining_Entity (Instance_Spec (U));
7369 return Defining_Entity (U);
7373 -- Start of processing for Use_Clause_Known
7376 -- If both current use type clause and the use type clause
7377 -- for the type are at the compilation unit level, one of
7378 -- the units must be an ancestor of the other, and the
7379 -- warning belongs on the descendant.
7381 if Nkind (Parent (Clause1)) = N_Compilation_Unit
7383 Nkind (Parent (Clause2)) = N_Compilation_Unit
7386 -- If the unit is a subprogram body that acts as spec,
7387 -- the context clause is shared with the constructed
7388 -- subprogram spec. Clearly there is no redundancy.
7390 if Clause1 = Clause2 then
7394 Unit1 := Unit (Parent (Clause1));
7395 Unit2 := Unit (Parent (Clause2));
7397 -- If both clauses are on same unit, or one is the body
7398 -- of the other, or one of them is in a subunit, report
7399 -- redundancy on the later one.
7401 if Unit1 = Unit2 then
7402 Error_Msg_Sloc := Sloc (Current_Use_Clause (T));
7404 ("& is already use-visible through previous "
7405 & "use_type_clause #?", Clause1, T);
7408 elsif Nkind (Unit1) = N_Subunit then
7409 Error_Msg_Sloc := Sloc (Current_Use_Clause (T));
7411 ("& is already use-visible through previous "
7412 & "use_type_clause #?", Clause1, T);
7415 elsif Nkind_In (Unit2, N_Package_Body, N_Subprogram_Body)
7416 and then Nkind (Unit1) /= Nkind (Unit2)
7417 and then Nkind (Unit1) /= N_Subunit
7419 Error_Msg_Sloc := Sloc (Clause1);
7421 ("& is already use-visible through previous "
7422 & "use_type_clause #?", Current_Use_Clause (T), T);
7426 -- There is a redundant use type clause in a child unit.
7427 -- Determine which of the units is more deeply nested.
7428 -- If a unit is a package instance, retrieve the entity
7429 -- and its scope from the instance spec.
7431 Ent1 := Entity_Of_Unit (Unit1);
7432 Ent2 := Entity_Of_Unit (Unit2);
7434 if Scope (Ent2) = Standard_Standard then
7435 Error_Msg_Sloc := Sloc (Current_Use_Clause (T));
7438 elsif Scope (Ent1) = Standard_Standard then
7439 Error_Msg_Sloc := Sloc (Id);
7442 -- If both units are child units, we determine which one
7443 -- is the descendant by the scope distance to the
7444 -- ultimate parent unit.
7453 while S1 /= Standard_Standard
7455 S2 /= Standard_Standard
7461 if S1 = Standard_Standard then
7462 Error_Msg_Sloc := Sloc (Id);
7465 Error_Msg_Sloc := Sloc (Current_Use_Clause (T));
7472 ("& is already use-visible through previous "
7473 & "use_type_clause #?", Err_No, Id);
7475 -- Case where current use type clause and the use type
7476 -- clause for the type are not both at the compilation unit
7477 -- level. In this case we don't have location information.
7481 ("& is already use-visible through previous "
7482 & "use type clause?", Id, T);
7484 end Use_Clause_Known;
7486 -- Here if Current_Use_Clause is not set for T, another case
7487 -- where we do not have the location information available.
7491 ("& is already use-visible through previous "
7492 & "use type clause?", Id, T);
7495 -- The package where T is declared is already used
7497 elsif In_Use (Scope (T)) then
7498 Error_Msg_Sloc := Sloc (Current_Use_Clause (Scope (T)));
7500 ("& is already use-visible through package use clause #?",
7503 -- The current scope is the package where T is declared
7506 Error_Msg_Node_2 := Scope (T);
7508 ("& is already use-visible inside package &?", Id, T);
7517 procedure Write_Info is
7518 Id : Entity_Id := First_Entity (Current_Scope);
7521 -- No point in dumping standard entities
7523 if Current_Scope = Standard_Standard then
7527 Write_Str ("========================================================");
7529 Write_Str (" Defined Entities in ");
7530 Write_Name (Chars (Current_Scope));
7532 Write_Str ("========================================================");
7536 Write_Str ("-- none --");
7540 while Present (Id) loop
7541 Write_Entity_Info (Id, " ");
7546 if Scope (Current_Scope) = Standard_Standard then
7548 -- Print information on the current unit itself
7550 Write_Entity_Info (Current_Scope, " ");
7560 procedure Write_Scopes is
7563 for J in reverse 1 .. Scope_Stack.Last loop
7564 S := Scope_Stack.Table (J).Entity;
7565 Write_Int (Int (S));
7566 Write_Str (" === ");
7567 Write_Name (Chars (S));
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