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
453 -- of 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);
789 Typ : Entity_Id := Empty;
792 Get_First_Interp (Nam, I, It);
793 while Present (It.Typ) loop
795 if Ekind (It.Typ) = Ekind (T)
796 and then Covers (T, It.Typ)
799 Set_Etype (Nam, Typ);
800 Set_Is_Overloaded (Nam, False);
803 Error_Msg_N ("ambiguous expression in renaming", N);
806 Get_Next_Interp (I, It);
813 -- Ada 2005 (AI-231): "In the case where the type is defined by an
814 -- access_definition, the renamed entity shall be of an access-to-
815 -- constant type if and only if the access_definition defines an
816 -- access-to-constant type" ARM 8.5.1(4)
818 if Constant_Present (Access_Definition (N))
819 and then not Is_Access_Constant (Etype (Nam))
821 Error_Msg_N ("(Ada 2005): the renamed object is not "
822 & "access-to-constant (RM 8.5.1(6))", N);
824 elsif not Constant_Present (Access_Definition (N))
825 and then Is_Access_Constant (Etype (Nam))
827 Error_Msg_N ("(Ada 2005): the renamed object is not "
828 & "access-to-variable (RM 8.5.1(6))", N);
831 if Is_Access_Subprogram_Type (Etype (Nam)) then
832 Check_Subtype_Conformant
833 (Designated_Type (T), Designated_Type (Etype (Nam)));
835 elsif not Subtypes_Statically_Match
836 (Designated_Type (T), Designated_Type (Etype (Nam)))
839 ("subtype of renamed object does not statically match", N);
843 -- Special processing for renaming function return object
845 if Nkind (Nam) = N_Function_Call
846 and then Comes_From_Source (Nam)
850 -- Usage is illegal in Ada 83
854 ("(Ada 83) cannot rename function return object", Nam);
856 -- In Ada 95, warn for odd case of renaming parameterless function
857 -- call if this is not a limited type (where this is useful)
860 if Warn_On_Object_Renames_Function
861 and then No (Parameter_Associations (Nam))
862 and then not Is_Limited_Type (Etype (Nam))
865 ("?renaming function result object is suspicious",
868 ("\?function & will be called only once",
869 Nam, Entity (Name (Nam)));
871 ("\?suggest using an initialized constant object instead",
877 -- An object renaming requires an exact match of the type. Class-wide
878 -- matching is not allowed.
880 if Is_Class_Wide_Type (T)
881 and then Base_Type (Etype (Nam)) /= Base_Type (T)
888 -- (Ada 2005: AI-326): Handle wrong use of incomplete type
890 if Nkind (Nam) = N_Explicit_Dereference
891 and then Ekind (Etype (T2)) = E_Incomplete_Type
893 Error_Msg_NE ("invalid use of incomplete type&", Id, T2);
895 elsif Ekind (Etype (T)) = E_Incomplete_Type then
896 Error_Msg_NE ("invalid use of incomplete type&", Id, T);
902 if Ada_Version >= Ada_05
903 and then Nkind (Nam) = N_Attribute_Reference
904 and then Attribute_Name (Nam) = Name_Priority
908 elsif Ada_Version >= Ada_05
909 and then Nkind (Nam) in N_Has_Entity
916 if Nkind (Nam) = N_Attribute_Reference then
917 Nam_Ent := Entity (Prefix (Nam));
919 Nam_Ent := Entity (Nam);
922 Nam_Decl := Parent (Nam_Ent);
924 if Has_Null_Exclusion (N)
925 and then not Has_Null_Exclusion (Nam_Decl)
927 -- Ada 2005 (AI-423): If the object name denotes a generic
928 -- formal object of a generic unit G, and the object renaming
929 -- declaration occurs within the body of G or within the body
930 -- of a generic unit declared within the declarative region
931 -- of G, then the declaration of the formal object of G must
932 -- have a null exclusion.
934 if Is_Formal_Object (Nam_Ent)
935 and then In_Generic_Scope (Id)
938 ("renamed formal does not exclude `NULL` "
939 & "(RM 8.5.1(4.6/2))", N);
941 -- Ada 2005 (AI-423): Otherwise, the subtype of the object name
942 -- shall exclude null.
944 elsif not Can_Never_Be_Null (Etype (Nam_Ent)) then
946 ("renamed object does not exclude `NULL` "
947 & "(RM 8.5.1(4.6/2))", N);
949 elsif Can_Never_Be_Null (Etype (Nam_Ent)) then
951 ("`NOT NULL` not allowed (type of& already excludes null)",
956 elsif Has_Null_Exclusion (N)
957 and then No (Access_Definition (N))
958 and then Can_Never_Be_Null (T)
961 ("`NOT NULL` not allowed (& already excludes null)", N, T);
966 Set_Ekind (Id, E_Variable);
967 Init_Size_Align (Id);
969 if T = Any_Type or else Etype (Nam) = Any_Type then
972 -- Verify that the renamed entity is an object or a function call. It
973 -- may have been rewritten in several ways.
975 elsif Is_Object_Reference (Nam) then
976 if Comes_From_Source (N)
977 and then Is_Dependent_Component_Of_Mutable_Object (Nam)
980 ("illegal renaming of discriminant-dependent component", Nam);
985 -- A static function call may have been folded into a literal
987 elsif Nkind (Original_Node (Nam)) = N_Function_Call
989 -- When expansion is disabled, attribute reference is not
990 -- rewritten as function call. Otherwise it may be rewritten
991 -- as a conversion, so check original node.
993 or else (Nkind (Original_Node (Nam)) = N_Attribute_Reference
994 and then Is_Function_Attribute_Name
995 (Attribute_Name (Original_Node (Nam))))
997 -- Weird but legal, equivalent to renaming a function call.
998 -- Illegal if the literal is the result of constant-folding an
999 -- attribute reference that is not a function.
1001 or else (Is_Entity_Name (Nam)
1002 and then Ekind (Entity (Nam)) = E_Enumeration_Literal
1004 Nkind (Original_Node (Nam)) /= N_Attribute_Reference)
1006 or else (Nkind (Nam) = N_Type_Conversion
1007 and then Is_Tagged_Type (Entity (Subtype_Mark (Nam))))
1011 elsif Nkind (Nam) = N_Type_Conversion then
1013 ("renaming of conversion only allowed for tagged types", Nam);
1015 -- Ada 2005 (AI-327)
1017 elsif Ada_Version >= Ada_05
1018 and then Nkind (Nam) = N_Attribute_Reference
1019 and then Attribute_Name (Nam) = Name_Priority
1023 -- Allow internally generated x'Reference expression
1025 elsif Nkind (Nam) = N_Reference then
1029 Error_Msg_N ("expect object name in renaming", Nam);
1034 if not Is_Variable (Nam) then
1035 Set_Ekind (Id, E_Constant);
1036 Set_Never_Set_In_Source (Id, True);
1037 Set_Is_True_Constant (Id, True);
1040 Set_Renamed_Object (Id, Nam);
1041 end Analyze_Object_Renaming;
1043 ------------------------------
1044 -- Analyze_Package_Renaming --
1045 ------------------------------
1047 procedure Analyze_Package_Renaming (N : Node_Id) is
1048 New_P : constant Entity_Id := Defining_Entity (N);
1053 if Name (N) = Error then
1057 -- Apply Text_IO kludge here, since we may be renaming one of the
1058 -- children of Text_IO.
1060 Text_IO_Kludge (Name (N));
1062 if Current_Scope /= Standard_Standard then
1063 Set_Is_Pure (New_P, Is_Pure (Current_Scope));
1069 if Is_Entity_Name (Name (N)) then
1070 Old_P := Entity (Name (N));
1075 if Etype (Old_P) = Any_Type then
1077 ("expect package name in renaming", Name (N));
1079 elsif Ekind (Old_P) /= E_Package
1080 and then not (Ekind (Old_P) = E_Generic_Package
1081 and then In_Open_Scopes (Old_P))
1083 if Ekind (Old_P) = E_Generic_Package then
1085 ("generic package cannot be renamed as a package", Name (N));
1087 Error_Msg_Sloc := Sloc (Old_P);
1089 ("expect package name in renaming, found& declared#",
1093 -- Set basic attributes to minimize cascaded errors
1095 Set_Ekind (New_P, E_Package);
1096 Set_Etype (New_P, Standard_Void_Type);
1098 -- Here for OK package renaming
1101 -- Entities in the old package are accessible through the renaming
1102 -- entity. The simplest implementation is to have both packages share
1105 Set_Ekind (New_P, E_Package);
1106 Set_Etype (New_P, Standard_Void_Type);
1108 if Present (Renamed_Object (Old_P)) then
1109 Set_Renamed_Object (New_P, Renamed_Object (Old_P));
1111 Set_Renamed_Object (New_P, Old_P);
1114 Set_Has_Completion (New_P);
1116 Set_First_Entity (New_P, First_Entity (Old_P));
1117 Set_Last_Entity (New_P, Last_Entity (Old_P));
1118 Set_First_Private_Entity (New_P, First_Private_Entity (Old_P));
1119 Check_Library_Unit_Renaming (N, Old_P);
1120 Generate_Reference (Old_P, Name (N));
1122 -- If the renaming is in the visible part of a package, then we set
1123 -- Renamed_In_Spec for the renamed package, to prevent giving
1124 -- warnings about no entities referenced. Such a warning would be
1125 -- overenthusiastic, since clients can see entities in the renamed
1126 -- package via the visible package renaming.
1129 Ent : constant Entity_Id := Cunit_Entity (Current_Sem_Unit);
1131 if Ekind (Ent) = E_Package
1132 and then not In_Private_Part (Ent)
1133 and then In_Extended_Main_Source_Unit (N)
1134 and then Ekind (Old_P) = E_Package
1136 Set_Renamed_In_Spec (Old_P);
1140 -- If this is the renaming declaration of a package instantiation
1141 -- within itself, it is the declaration that ends the list of actuals
1142 -- for the instantiation. At this point, the subtypes that rename
1143 -- the actuals are flagged as generic, to avoid spurious ambiguities
1144 -- if the actuals for two distinct formals happen to coincide. If
1145 -- the actual is a private type, the subtype has a private completion
1146 -- that is flagged in the same fashion.
1148 -- Resolution is identical to what is was in the original generic.
1149 -- On exit from the generic instance, these are turned into regular
1150 -- subtypes again, so they are compatible with types in their class.
1152 if not Is_Generic_Instance (Old_P) then
1155 Spec := Specification (Unit_Declaration_Node (Old_P));
1158 if Nkind (Spec) = N_Package_Specification
1159 and then Present (Generic_Parent (Spec))
1160 and then Old_P = Current_Scope
1161 and then Chars (New_P) = Chars (Generic_Parent (Spec))
1167 E := First_Entity (Old_P);
1172 and then Nkind (Parent (E)) = N_Subtype_Declaration
1174 Set_Is_Generic_Actual_Type (E);
1176 if Is_Private_Type (E)
1177 and then Present (Full_View (E))
1179 Set_Is_Generic_Actual_Type (Full_View (E));
1188 end Analyze_Package_Renaming;
1190 -------------------------------
1191 -- Analyze_Renamed_Character --
1192 -------------------------------
1194 procedure Analyze_Renamed_Character
1199 C : constant Node_Id := Name (N);
1202 if Ekind (New_S) = E_Function then
1203 Resolve (C, Etype (New_S));
1206 Check_Frozen_Renaming (N, New_S);
1210 Error_Msg_N ("character literal can only be renamed as function", N);
1212 end Analyze_Renamed_Character;
1214 ---------------------------------
1215 -- Analyze_Renamed_Dereference --
1216 ---------------------------------
1218 procedure Analyze_Renamed_Dereference
1223 Nam : constant Node_Id := Name (N);
1224 P : constant Node_Id := Prefix (Nam);
1230 if not Is_Overloaded (P) then
1231 if Ekind (Etype (Nam)) /= E_Subprogram_Type
1232 or else not Type_Conformant (Etype (Nam), New_S) then
1233 Error_Msg_N ("designated type does not match specification", P);
1242 Get_First_Interp (Nam, Ind, It);
1244 while Present (It.Nam) loop
1246 if Ekind (It.Nam) = E_Subprogram_Type
1247 and then Type_Conformant (It.Nam, New_S) then
1249 if Typ /= Any_Id then
1250 Error_Msg_N ("ambiguous renaming", P);
1257 Get_Next_Interp (Ind, It);
1260 if Typ = Any_Type then
1261 Error_Msg_N ("designated type does not match specification", P);
1266 Check_Frozen_Renaming (N, New_S);
1270 end Analyze_Renamed_Dereference;
1272 ---------------------------
1273 -- Analyze_Renamed_Entry --
1274 ---------------------------
1276 procedure Analyze_Renamed_Entry
1281 Nam : constant Node_Id := Name (N);
1282 Sel : constant Node_Id := Selector_Name (Nam);
1286 if Entity (Sel) = Any_Id then
1288 -- Selector is undefined on prefix. Error emitted already
1290 Set_Has_Completion (New_S);
1294 -- Otherwise find renamed entity and build body of New_S as a call to it
1296 Old_S := Find_Renamed_Entity (N, Selector_Name (Nam), New_S);
1298 if Old_S = Any_Id then
1299 Error_Msg_N (" no subprogram or entry matches specification", N);
1302 Check_Subtype_Conformant (New_S, Old_S, N);
1303 Generate_Reference (New_S, Defining_Entity (N), 'b');
1304 Style.Check_Identifier (Defining_Entity (N), New_S);
1307 -- Only mode conformance required for a renaming_as_declaration
1309 Check_Mode_Conformant (New_S, Old_S, N);
1312 Inherit_Renamed_Profile (New_S, Old_S);
1314 -- The prefix can be an arbitrary expression that yields a task
1315 -- type, so it must be resolved.
1317 Resolve (Prefix (Nam), Scope (Old_S));
1320 Set_Convention (New_S, Convention (Old_S));
1321 Set_Has_Completion (New_S, Inside_A_Generic);
1324 Check_Frozen_Renaming (N, New_S);
1326 end Analyze_Renamed_Entry;
1328 -----------------------------------
1329 -- Analyze_Renamed_Family_Member --
1330 -----------------------------------
1332 procedure Analyze_Renamed_Family_Member
1337 Nam : constant Node_Id := Name (N);
1338 P : constant Node_Id := Prefix (Nam);
1342 if (Is_Entity_Name (P) and then Ekind (Entity (P)) = E_Entry_Family)
1343 or else (Nkind (P) = N_Selected_Component
1345 Ekind (Entity (Selector_Name (P))) = E_Entry_Family)
1347 if Is_Entity_Name (P) then
1348 Old_S := Entity (P);
1350 Old_S := Entity (Selector_Name (P));
1353 if not Entity_Matches_Spec (Old_S, New_S) then
1354 Error_Msg_N ("entry family does not match specification", N);
1357 Check_Subtype_Conformant (New_S, Old_S, N);
1358 Generate_Reference (New_S, Defining_Entity (N), 'b');
1359 Style.Check_Identifier (Defining_Entity (N), New_S);
1363 Error_Msg_N ("no entry family matches specification", N);
1366 Set_Has_Completion (New_S, Inside_A_Generic);
1369 Check_Frozen_Renaming (N, New_S);
1371 end Analyze_Renamed_Family_Member;
1373 -----------------------------------------
1374 -- Analyze_Renamed_Primitive_Operation --
1375 -----------------------------------------
1377 procedure Analyze_Renamed_Primitive_Operation
1386 Ctyp : Conformance_Type) return Boolean;
1387 -- Verify that the signatures of the renamed entity and the new entity
1388 -- match. The first formal of the renamed entity is skipped because it
1389 -- is the target object in any subsequent call.
1393 Ctyp : Conformance_Type) return Boolean
1399 if Ekind (Subp) /= Ekind (New_S) then
1403 Old_F := Next_Formal (First_Formal (Subp));
1404 New_F := First_Formal (New_S);
1405 while Present (Old_F) and then Present (New_F) loop
1406 if not Conforming_Types (Etype (Old_F), Etype (New_F), Ctyp) then
1410 if Ctyp >= Mode_Conformant
1411 and then Ekind (Old_F) /= Ekind (New_F)
1416 Next_Formal (New_F);
1417 Next_Formal (Old_F);
1424 if not Is_Overloaded (Selector_Name (Name (N))) then
1425 Old_S := Entity (Selector_Name (Name (N)));
1427 if not Conforms (Old_S, Type_Conformant) then
1432 -- Find the operation that matches the given signature
1440 Get_First_Interp (Selector_Name (Name (N)), Ind, It);
1442 while Present (It.Nam) loop
1443 if Conforms (It.Nam, Type_Conformant) then
1447 Get_Next_Interp (Ind, It);
1452 if Old_S = Any_Id then
1453 Error_Msg_N (" no subprogram or entry matches specification", N);
1457 if not Conforms (Old_S, Subtype_Conformant) then
1458 Error_Msg_N ("subtype conformance error in renaming", N);
1461 Generate_Reference (New_S, Defining_Entity (N), 'b');
1462 Style.Check_Identifier (Defining_Entity (N), New_S);
1465 -- Only mode conformance required for a renaming_as_declaration
1467 if not Conforms (Old_S, Mode_Conformant) then
1468 Error_Msg_N ("mode conformance error in renaming", N);
1472 -- Inherit_Renamed_Profile (New_S, Old_S);
1474 -- The prefix can be an arbitrary expression that yields an
1475 -- object, so it must be resolved.
1477 Resolve (Prefix (Name (N)));
1479 end Analyze_Renamed_Primitive_Operation;
1481 ---------------------------------
1482 -- Analyze_Subprogram_Renaming --
1483 ---------------------------------
1485 procedure Analyze_Subprogram_Renaming (N : Node_Id) is
1486 Formal_Spec : constant Node_Id := Corresponding_Formal_Spec (N);
1487 Is_Actual : constant Boolean := Present (Formal_Spec);
1488 Inst_Node : Node_Id := Empty;
1489 Nam : constant Node_Id := Name (N);
1491 Old_S : Entity_Id := Empty;
1492 Rename_Spec : Entity_Id;
1493 Save_AV : constant Ada_Version_Type := Ada_Version;
1494 Save_AV_Exp : constant Ada_Version_Type := Ada_Version_Explicit;
1495 Spec : constant Node_Id := Specification (N);
1497 procedure Check_Null_Exclusion
1500 -- Ada 2005 (AI-423): Given renaming Ren of subprogram Sub, check the
1501 -- following AI rules:
1503 -- If Ren is a renaming of a formal subprogram and one of its
1504 -- parameters has a null exclusion, then the corresponding formal
1505 -- in Sub must also have one. Otherwise the subtype of the Sub's
1506 -- formal parameter must exclude null.
1508 -- If Ren is a renaming of a formal function and its return
1509 -- profile has a null exclusion, then Sub's return profile must
1510 -- have one. Otherwise the subtype of Sub's return profile must
1513 function Original_Subprogram (Subp : Entity_Id) return Entity_Id;
1514 -- Find renamed entity when the declaration is a renaming_as_body and
1515 -- the renamed entity may itself be a renaming_as_body. Used to enforce
1516 -- rule that a renaming_as_body is illegal if the declaration occurs
1517 -- before the subprogram it completes is frozen, and renaming indirectly
1518 -- renames the subprogram itself.(Defect Report 8652/0027).
1520 --------------------------
1521 -- Check_Null_Exclusion --
1522 --------------------------
1524 procedure Check_Null_Exclusion
1528 Ren_Formal : Entity_Id;
1529 Sub_Formal : Entity_Id;
1534 Ren_Formal := First_Formal (Ren);
1535 Sub_Formal := First_Formal (Sub);
1536 while Present (Ren_Formal)
1537 and then Present (Sub_Formal)
1539 if Has_Null_Exclusion (Parent (Ren_Formal))
1541 not (Has_Null_Exclusion (Parent (Sub_Formal))
1542 or else Can_Never_Be_Null (Etype (Sub_Formal)))
1545 ("`NOT NULL` required for parameter &",
1546 Parent (Sub_Formal), Sub_Formal);
1549 Next_Formal (Ren_Formal);
1550 Next_Formal (Sub_Formal);
1553 -- Return profile check
1555 if Nkind (Parent (Ren)) = N_Function_Specification
1556 and then Nkind (Parent (Sub)) = N_Function_Specification
1557 and then Has_Null_Exclusion (Parent (Ren))
1559 not (Has_Null_Exclusion (Parent (Sub))
1560 or else Can_Never_Be_Null (Etype (Sub)))
1563 ("return must specify `NOT NULL`",
1564 Result_Definition (Parent (Sub)));
1566 end Check_Null_Exclusion;
1568 -------------------------
1569 -- Original_Subprogram --
1570 -------------------------
1572 function Original_Subprogram (Subp : Entity_Id) return Entity_Id is
1573 Orig_Decl : Node_Id;
1574 Orig_Subp : Entity_Id;
1577 -- First case: renamed entity is itself a renaming
1579 if Present (Alias (Subp)) then
1580 return Alias (Subp);
1583 Nkind (Unit_Declaration_Node (Subp)) = N_Subprogram_Declaration
1585 (Corresponding_Body (Unit_Declaration_Node (Subp)))
1587 -- Check if renamed entity is a renaming_as_body
1590 Unit_Declaration_Node
1591 (Corresponding_Body (Unit_Declaration_Node (Subp)));
1593 if Nkind (Orig_Decl) = N_Subprogram_Renaming_Declaration then
1594 Orig_Subp := Entity (Name (Orig_Decl));
1596 if Orig_Subp = Rename_Spec then
1598 -- Circularity detected
1603 return (Original_Subprogram (Orig_Subp));
1611 end Original_Subprogram;
1613 -- Start of processing for Analyze_Subprogram_Renaming
1616 -- We must test for the attribute renaming case before the Analyze
1617 -- call because otherwise Sem_Attr will complain that the attribute
1618 -- is missing an argument when it is analyzed.
1620 if Nkind (Nam) = N_Attribute_Reference then
1622 -- In the case of an abstract formal subprogram association, rewrite
1623 -- an actual given by a stream attribute as the name of the
1624 -- corresponding stream primitive of the type.
1626 -- In a generic context the stream operations are not generated, and
1627 -- this must be treated as a normal attribute reference, to be
1628 -- expanded in subsequent instantiations.
1630 if Is_Actual and then Is_Abstract_Subprogram (Formal_Spec)
1631 and then Expander_Active
1634 Stream_Prim : Entity_Id;
1635 Prefix_Type : constant Entity_Id := Entity (Prefix (Nam));
1638 -- The class-wide forms of the stream attributes are not
1639 -- primitive dispatching operations (even though they
1640 -- internally dispatch to a stream attribute).
1642 if Is_Class_Wide_Type (Prefix_Type) then
1644 ("attribute must be a primitive dispatching operation",
1649 -- Retrieve the primitive subprogram associated with the
1650 -- attribute. This can only be a stream attribute, since those
1651 -- are the only ones that are dispatching (and the actual for
1652 -- an abstract formal subprogram must be dispatching
1656 case Attribute_Name (Nam) is
1659 Find_Prim_Op (Prefix_Type, TSS_Stream_Input);
1662 Find_Prim_Op (Prefix_Type, TSS_Stream_Output);
1665 Find_Prim_Op (Prefix_Type, TSS_Stream_Read);
1668 Find_Prim_Op (Prefix_Type, TSS_Stream_Write);
1671 ("attribute must be a primitive"
1672 & " dispatching operation", Nam);
1678 -- If no operation was found, and the type is limited,
1679 -- the user should have defined one.
1681 when Program_Error =>
1682 if Is_Limited_Type (Prefix_Type) then
1684 ("stream operation not defined for type&",
1688 -- Otherwise, compiler should have generated default
1695 -- Rewrite the attribute into the name of its corresponding
1696 -- primitive dispatching subprogram. We can then proceed with
1697 -- the usual processing for subprogram renamings.
1700 Prim_Name : constant Node_Id :=
1701 Make_Identifier (Sloc (Nam),
1702 Chars => Chars (Stream_Prim));
1704 Set_Entity (Prim_Name, Stream_Prim);
1705 Rewrite (Nam, Prim_Name);
1710 -- Normal processing for a renaming of an attribute
1713 Attribute_Renaming (N);
1718 -- Check whether this declaration corresponds to the instantiation
1719 -- of a formal subprogram.
1721 -- If this is an instantiation, the corresponding actual is frozen and
1722 -- error messages can be made more precise. If this is a default
1723 -- subprogram, the entity is already established in the generic, and is
1724 -- not retrieved by visibility. If it is a default with a box, the
1725 -- candidate interpretations, if any, have been collected when building
1726 -- the renaming declaration. If overloaded, the proper interpretation is
1727 -- determined in Find_Renamed_Entity. If the entity is an operator,
1728 -- Find_Renamed_Entity applies additional visibility checks.
1731 Inst_Node := Unit_Declaration_Node (Formal_Spec);
1733 if Is_Entity_Name (Nam)
1734 and then Present (Entity (Nam))
1735 and then not Comes_From_Source (Nam)
1736 and then not Is_Overloaded (Nam)
1738 Old_S := Entity (Nam);
1739 New_S := Analyze_Subprogram_Specification (Spec);
1743 if Ekind (Entity (Nam)) = E_Operator then
1747 if Box_Present (Inst_Node) then
1748 Old_S := Find_Renamed_Entity (N, Name (N), New_S, Is_Actual);
1750 -- If there is an immediately visible homonym of the operator
1751 -- and the declaration has a default, this is worth a warning
1752 -- because the user probably did not intend to get the pre-
1753 -- defined operator, visible in the generic declaration. To
1754 -- find if there is an intended candidate, analyze the renaming
1755 -- again in the current context.
1757 elsif Scope (Old_S) = Standard_Standard
1758 and then Present (Default_Name (Inst_Node))
1761 Decl : constant Node_Id := New_Copy_Tree (N);
1765 Set_Entity (Name (Decl), Empty);
1766 Analyze (Name (Decl));
1768 Find_Renamed_Entity (Decl, Name (Decl), New_S, True);
1771 and then In_Open_Scopes (Scope (Hidden))
1772 and then Is_Immediately_Visible (Hidden)
1773 and then Comes_From_Source (Hidden)
1774 and then Hidden /= Old_S
1776 Error_Msg_Sloc := Sloc (Hidden);
1777 Error_Msg_N ("?default subprogram is resolved " &
1778 "in the generic declaration " &
1779 "(RM 12.6(17))", N);
1780 Error_Msg_NE ("\?and will not use & #", N, Hidden);
1788 New_S := Analyze_Subprogram_Specification (Spec);
1792 -- Renamed entity must be analyzed first, to avoid being hidden by
1793 -- new name (which might be the same in a generic instance).
1797 -- The renaming defines a new overloaded entity, which is analyzed
1798 -- like a subprogram declaration.
1800 New_S := Analyze_Subprogram_Specification (Spec);
1803 if Current_Scope /= Standard_Standard then
1804 Set_Is_Pure (New_S, Is_Pure (Current_Scope));
1807 Rename_Spec := Find_Corresponding_Spec (N);
1809 -- Case of Renaming_As_Body
1811 if Present (Rename_Spec) then
1813 -- Renaming declaration is the completion of the declaration of
1814 -- Rename_Spec. We build an actual body for it at the freezing point.
1816 Set_Corresponding_Spec (N, Rename_Spec);
1818 -- Deal with special case of stream functions of abstract types
1821 if Nkind (Unit_Declaration_Node (Rename_Spec)) =
1822 N_Abstract_Subprogram_Declaration
1824 -- Input stream functions are abstract if the object type is
1825 -- abstract. Similarly, all default stream functions for an
1826 -- interface type are abstract. However, these subprograms may
1827 -- receive explicit declarations in representation clauses, making
1828 -- the attribute subprograms usable as defaults in subsequent
1830 -- In this case we rewrite the declaration to make the subprogram
1831 -- non-abstract. We remove the previous declaration, and insert
1832 -- the new one at the point of the renaming, to prevent premature
1833 -- access to unfrozen types. The new declaration reuses the
1834 -- specification of the previous one, and must not be analyzed.
1837 (Is_Primitive (Entity (Nam))
1839 Is_Abstract_Type (Find_Dispatching_Type (Entity (Nam))));
1841 Old_Decl : constant Node_Id :=
1842 Unit_Declaration_Node (Rename_Spec);
1843 New_Decl : constant Node_Id :=
1844 Make_Subprogram_Declaration (Sloc (N),
1846 Relocate_Node (Specification (Old_Decl)));
1849 Insert_After (N, New_Decl);
1850 Set_Is_Abstract_Subprogram (Rename_Spec, False);
1851 Set_Analyzed (New_Decl);
1855 Set_Corresponding_Body (Unit_Declaration_Node (Rename_Spec), New_S);
1857 if Ada_Version = Ada_83 and then Comes_From_Source (N) then
1858 Error_Msg_N ("(Ada 83) renaming cannot serve as a body", N);
1861 Set_Convention (New_S, Convention (Rename_Spec));
1862 Check_Fully_Conformant (New_S, Rename_Spec);
1863 Set_Public_Status (New_S);
1865 -- The specification does not introduce new formals, but only
1866 -- repeats the formals of the original subprogram declaration.
1867 -- For cross-reference purposes, and for refactoring tools, we
1868 -- treat the formals of the renaming declaration as body formals.
1870 Reference_Body_Formals (Rename_Spec, New_S);
1872 -- Indicate that the entity in the declaration functions like the
1873 -- corresponding body, and is not a new entity. The body will be
1874 -- constructed later at the freeze point, so indicate that the
1875 -- completion has not been seen yet.
1877 Set_Ekind (New_S, E_Subprogram_Body);
1878 New_S := Rename_Spec;
1879 Set_Has_Completion (Rename_Spec, False);
1881 -- Ada 2005: check overriding indicator
1883 if Is_Overriding_Operation (Rename_Spec) then
1884 if Must_Not_Override (Specification (N)) then
1886 ("subprogram& overrides inherited operation",
1889 Style_Check and then not Must_Override (Specification (N))
1891 Style.Missing_Overriding (N, Rename_Spec);
1894 elsif Must_Override (Specification (N)) then
1895 Error_Msg_NE ("subprogram& is not overriding", N, Rename_Spec);
1898 -- Normal subprogram renaming (not renaming as body)
1901 Generate_Definition (New_S);
1902 New_Overloaded_Entity (New_S);
1904 if Is_Entity_Name (Nam)
1905 and then Is_Intrinsic_Subprogram (Entity (Nam))
1909 Check_Delayed_Subprogram (New_S);
1913 -- There is no need for elaboration checks on the new entity, which may
1914 -- be called before the next freezing point where the body will appear.
1915 -- Elaboration checks refer to the real entity, not the one created by
1916 -- the renaming declaration.
1918 Set_Kill_Elaboration_Checks (New_S, True);
1920 if Etype (Nam) = Any_Type then
1921 Set_Has_Completion (New_S);
1924 elsif Nkind (Nam) = N_Selected_Component then
1926 -- A prefix of the form A.B can designate an entry of task A, a
1927 -- protected operation of protected object A, or finally a primitive
1928 -- operation of object A. In the later case, A is an object of some
1929 -- tagged type, or an access type that denotes one such. To further
1930 -- distinguish these cases, note that the scope of a task entry or
1931 -- protected operation is type of the prefix.
1933 -- The prefix could be an overloaded function call that returns both
1934 -- kinds of operations. This overloading pathology is left to the
1935 -- dedicated reader ???
1938 T : constant Entity_Id := Etype (Prefix (Nam));
1947 Is_Tagged_Type (Designated_Type (T))))
1948 and then Scope (Entity (Selector_Name (Nam))) /= T
1950 Analyze_Renamed_Primitive_Operation
1951 (N, New_S, Present (Rename_Spec));
1955 -- Renamed entity is an entry or protected operation. For those
1956 -- cases an explicit body is built (at the point of freezing of
1957 -- this entity) that contains a call to the renamed entity.
1959 -- This is not allowed for renaming as body if the renamed
1960 -- spec is already frozen (see RM 8.5.4(5) for details).
1962 if Present (Rename_Spec)
1963 and then Is_Frozen (Rename_Spec)
1966 ("renaming-as-body cannot rename entry as subprogram", N);
1968 ("\since & is already frozen (RM 8.5.4(5))",
1971 Analyze_Renamed_Entry (N, New_S, Present (Rename_Spec));
1978 elsif Nkind (Nam) = N_Explicit_Dereference then
1980 -- Renamed entity is designated by access_to_subprogram expression.
1981 -- Must build body to encapsulate call, as in the entry case.
1983 Analyze_Renamed_Dereference (N, New_S, Present (Rename_Spec));
1986 elsif Nkind (Nam) = N_Indexed_Component then
1987 Analyze_Renamed_Family_Member (N, New_S, Present (Rename_Spec));
1990 elsif Nkind (Nam) = N_Character_Literal then
1991 Analyze_Renamed_Character (N, New_S, Present (Rename_Spec));
1994 elsif (not Is_Entity_Name (Nam)
1995 and then Nkind (Nam) /= N_Operator_Symbol)
1996 or else not Is_Overloadable (Entity (Nam))
1998 Error_Msg_N ("expect valid subprogram name in renaming", N);
2002 -- Find the renamed entity that matches the given specification. Disable
2003 -- Ada_83 because there is no requirement of full conformance between
2004 -- renamed entity and new entity, even though the same circuit is used.
2006 -- This is a bit of a kludge, which introduces a really irregular use of
2007 -- Ada_Version[_Explicit]. Would be nice to find cleaner way to do this
2010 Ada_Version := Ada_Version_Type'Max (Ada_Version, Ada_95);
2011 Ada_Version_Explicit := Ada_Version;
2014 Old_S := Find_Renamed_Entity (N, Name (N), New_S, Is_Actual);
2016 -- When the renamed subprogram is overloaded and used as an actual
2017 -- of a generic, its entity is set to the first available homonym.
2018 -- We must first disambiguate the name, then set the proper entity.
2021 and then Is_Overloaded (Nam)
2023 Set_Entity (Nam, Old_S);
2027 -- Most common case: subprogram renames subprogram. No body is generated
2028 -- in this case, so we must indicate the declaration is complete as is.
2029 -- and inherit various attributes of the renamed subprogram.
2031 if No (Rename_Spec) then
2032 Set_Has_Completion (New_S);
2033 Set_Is_Imported (New_S, Is_Imported (Entity (Nam)));
2034 Set_Is_Pure (New_S, Is_Pure (Entity (Nam)));
2035 Set_Is_Preelaborated (New_S, Is_Preelaborated (Entity (Nam)));
2037 -- Ada 2005 (AI-423): Check the consistency of null exclusions
2038 -- between a subprogram and its correct renaming.
2040 -- Note: the Any_Id check is a guard that prevents compiler crashes
2041 -- when performing a null exclusion check between a renaming and a
2042 -- renamed subprogram that has been found to be illegal.
2044 if Ada_Version >= Ada_05
2045 and then Entity (Nam) /= Any_Id
2047 Check_Null_Exclusion
2049 Sub => Entity (Nam));
2052 -- Enforce the Ada 2005 rule that the renamed entity cannot require
2053 -- overriding. The flag Requires_Overriding is set very selectively
2054 -- and misses some other illegal cases. The additional conditions
2055 -- checked below are sufficient but not necessary ???
2057 -- The rule does not apply to the renaming generated for an actual
2058 -- subprogram in an instance.
2063 -- Guard against previous errors, and omit renamings of predefined
2066 elsif Ekind (Old_S) /= E_Function
2067 and then Ekind (Old_S) /= E_Procedure
2071 elsif Requires_Overriding (Old_S)
2073 (Is_Abstract_Subprogram (Old_S)
2074 and then Present (Find_Dispatching_Type (Old_S))
2076 not Is_Abstract_Type (Find_Dispatching_Type (Old_S)))
2079 ("renamed entity cannot be "
2080 & "subprogram that requires overriding (RM 8.5.4 (5.1))", N);
2084 if Old_S /= Any_Id then
2086 and then From_Default (N)
2088 -- This is an implicit reference to the default actual
2090 Generate_Reference (Old_S, Nam, Typ => 'i', Force => True);
2092 Generate_Reference (Old_S, Nam);
2095 -- For a renaming-as-body, require subtype conformance, but if the
2096 -- declaration being completed has not been frozen, then inherit the
2097 -- convention of the renamed subprogram prior to checking conformance
2098 -- (unless the renaming has an explicit convention established; the
2099 -- rule stated in the RM doesn't seem to address this ???).
2101 if Present (Rename_Spec) then
2102 Generate_Reference (Rename_Spec, Defining_Entity (Spec), 'b');
2103 Style.Check_Identifier (Defining_Entity (Spec), Rename_Spec);
2105 if not Is_Frozen (Rename_Spec) then
2106 if not Has_Convention_Pragma (Rename_Spec) then
2107 Set_Convention (New_S, Convention (Old_S));
2110 if Ekind (Old_S) /= E_Operator then
2111 Check_Mode_Conformant (New_S, Old_S, Spec);
2114 if Original_Subprogram (Old_S) = Rename_Spec then
2115 Error_Msg_N ("unfrozen subprogram cannot rename itself ", N);
2118 Check_Subtype_Conformant (New_S, Old_S, Spec);
2121 Check_Frozen_Renaming (N, Rename_Spec);
2123 -- Check explicitly that renamed entity is not intrinsic, because
2124 -- in a generic the renamed body is not built. In this case,
2125 -- the renaming_as_body is a completion.
2127 if Inside_A_Generic then
2128 if Is_Frozen (Rename_Spec)
2129 and then Is_Intrinsic_Subprogram (Old_S)
2132 ("subprogram in renaming_as_body cannot be intrinsic",
2136 Set_Has_Completion (Rename_Spec);
2139 elsif Ekind (Old_S) /= E_Operator then
2140 Check_Mode_Conformant (New_S, Old_S);
2143 and then Error_Posted (New_S)
2145 Error_Msg_NE ("invalid actual subprogram: & #!", N, Old_S);
2149 if No (Rename_Spec) then
2151 -- The parameter profile of the new entity is that of the renamed
2152 -- entity: the subtypes given in the specification are irrelevant.
2154 Inherit_Renamed_Profile (New_S, Old_S);
2156 -- A call to the subprogram is transformed into a call to the
2157 -- renamed entity. This is transitive if the renamed entity is
2158 -- itself a renaming.
2160 if Present (Alias (Old_S)) then
2161 Set_Alias (New_S, Alias (Old_S));
2163 Set_Alias (New_S, Old_S);
2166 -- Note that we do not set Is_Intrinsic_Subprogram if we have a
2167 -- renaming as body, since the entity in this case is not an
2168 -- intrinsic (it calls an intrinsic, but we have a real body for
2169 -- this call, and it is in this body that the required intrinsic
2170 -- processing will take place).
2172 -- Also, if this is a renaming of inequality, the renamed operator
2173 -- is intrinsic, but what matters is the corresponding equality
2174 -- operator, which may be user-defined.
2176 Set_Is_Intrinsic_Subprogram
2178 Is_Intrinsic_Subprogram (Old_S)
2180 (Chars (Old_S) /= Name_Op_Ne
2181 or else Ekind (Old_S) = E_Operator
2183 Is_Intrinsic_Subprogram
2184 (Corresponding_Equality (Old_S))));
2186 if Ekind (Alias (New_S)) = E_Operator then
2187 Set_Has_Delayed_Freeze (New_S, False);
2190 -- If the renaming corresponds to an association for an abstract
2191 -- formal subprogram, then various attributes must be set to
2192 -- indicate that the renaming is an abstract dispatching operation
2193 -- with a controlling type.
2195 if Is_Actual and then Is_Abstract_Subprogram (Formal_Spec) then
2197 -- Mark the renaming as abstract here, so Find_Dispatching_Type
2198 -- see it as corresponding to a generic association for a
2199 -- formal abstract subprogram
2201 Set_Is_Abstract_Subprogram (New_S);
2204 New_S_Ctrl_Type : constant Entity_Id :=
2205 Find_Dispatching_Type (New_S);
2206 Old_S_Ctrl_Type : constant Entity_Id :=
2207 Find_Dispatching_Type (Old_S);
2210 if Old_S_Ctrl_Type /= New_S_Ctrl_Type then
2212 ("actual must be dispatching subprogram for type&",
2213 Nam, New_S_Ctrl_Type);
2216 Set_Is_Dispatching_Operation (New_S);
2217 Check_Controlling_Formals (New_S_Ctrl_Type, New_S);
2219 -- If the actual in the formal subprogram is itself a
2220 -- formal abstract subprogram association, there's no
2221 -- dispatch table component or position to inherit.
2223 if Present (DTC_Entity (Old_S)) then
2224 Set_DTC_Entity (New_S, DTC_Entity (Old_S));
2225 Set_DT_Position (New_S, DT_Position (Old_S));
2233 and then (Old_S = New_S
2234 or else (Nkind (Nam) /= N_Expanded_Name
2235 and then Chars (Old_S) = Chars (New_S)))
2237 Error_Msg_N ("subprogram cannot rename itself", N);
2240 Set_Convention (New_S, Convention (Old_S));
2242 if Is_Abstract_Subprogram (Old_S) then
2243 if Present (Rename_Spec) then
2245 ("a renaming-as-body cannot rename an abstract subprogram",
2247 Set_Has_Completion (Rename_Spec);
2249 Set_Is_Abstract_Subprogram (New_S);
2253 Check_Library_Unit_Renaming (N, Old_S);
2255 -- Pathological case: procedure renames entry in the scope of its
2256 -- task. Entry is given by simple name, but body must be built for
2257 -- procedure. Of course if called it will deadlock.
2259 if Ekind (Old_S) = E_Entry then
2260 Set_Has_Completion (New_S, False);
2261 Set_Alias (New_S, Empty);
2265 Freeze_Before (N, Old_S);
2266 Set_Has_Delayed_Freeze (New_S, False);
2267 Freeze_Before (N, New_S);
2269 -- An abstract subprogram is only allowed as an actual in the case
2270 -- where the formal subprogram is also abstract.
2272 if (Ekind (Old_S) = E_Procedure or else Ekind (Old_S) = E_Function)
2273 and then Is_Abstract_Subprogram (Old_S)
2274 and then not Is_Abstract_Subprogram (Formal_Spec)
2277 ("abstract subprogram not allowed as generic actual", Nam);
2282 -- A common error is to assume that implicit operators for types are
2283 -- defined in Standard, or in the scope of a subtype. In those cases
2284 -- where the renamed entity is given with an expanded name, it is
2285 -- worth mentioning that operators for the type are not declared in
2286 -- the scope given by the prefix.
2288 if Nkind (Nam) = N_Expanded_Name
2289 and then Nkind (Selector_Name (Nam)) = N_Operator_Symbol
2290 and then Scope (Entity (Nam)) = Standard_Standard
2293 T : constant Entity_Id :=
2294 Base_Type (Etype (First_Formal (New_S)));
2296 Error_Msg_Node_2 := Prefix (Nam);
2298 ("operator for type& is not declared in&", Prefix (Nam), T);
2303 ("no visible subprogram matches the specification for&",
2307 if Present (Candidate_Renaming) then
2313 F1 := First_Formal (Candidate_Renaming);
2314 F2 := First_Formal (New_S);
2316 while Present (F1) and then Present (F2) loop
2321 if Present (F1) and then Present (Default_Value (F1)) then
2322 if Present (Next_Formal (F1)) then
2324 ("\missing specification for &" &
2325 " and other formals with defaults", Spec, F1);
2328 ("\missing specification for &", Spec, F1);
2335 -- Ada 2005 AI 404: if the new subprogram is dispatching, verify that
2336 -- controlling access parameters are known non-null for the renamed
2337 -- subprogram. Test also applies to a subprogram instantiation that
2338 -- is dispatching. Test is skipped if some previous error was detected
2339 -- that set Old_S to Any_Id.
2341 if Ada_Version >= Ada_05
2342 and then Old_S /= Any_Id
2343 and then not Is_Dispatching_Operation (Old_S)
2344 and then Is_Dispatching_Operation (New_S)
2351 Old_F := First_Formal (Old_S);
2352 New_F := First_Formal (New_S);
2353 while Present (Old_F) loop
2354 if Ekind (Etype (Old_F)) = E_Anonymous_Access_Type
2355 and then Is_Controlling_Formal (New_F)
2356 and then not Can_Never_Be_Null (Old_F)
2358 Error_Msg_N ("access parameter is controlling,", New_F);
2360 ("\corresponding parameter of& "
2361 & "must be explicitly null excluding", New_F, Old_S);
2364 Next_Formal (Old_F);
2365 Next_Formal (New_F);
2370 -- A useful warning, suggested by Ada Bug Finder (Ada-Europe 2005)
2372 if Comes_From_Source (N)
2373 and then Present (Old_S)
2374 and then Nkind (Old_S) = N_Defining_Operator_Symbol
2375 and then Nkind (New_S) = N_Defining_Operator_Symbol
2376 and then Chars (Old_S) /= Chars (New_S)
2379 ("?& is being renamed as a different operator",
2383 -- Another warning or some utility: if the new subprogram as the same
2384 -- name as the old one, the old one is not hidden by an outer homograph,
2385 -- the new one is not a public symbol, and the old one is otherwise
2386 -- directly visible, the renaming is superfluous.
2388 if Chars (Old_S) = Chars (New_S)
2389 and then Comes_From_Source (N)
2390 and then Scope (Old_S) /= Standard_Standard
2391 and then Warn_On_Redundant_Constructs
2393 (Is_Immediately_Visible (Old_S)
2394 or else Is_Potentially_Use_Visible (Old_S))
2395 and then Is_Overloadable (Current_Scope)
2396 and then Chars (Current_Scope) /= Chars (Old_S)
2399 ("?redundant renaming, entity is directly visible", Name (N));
2402 Ada_Version := Save_AV;
2403 Ada_Version_Explicit := Save_AV_Exp;
2404 end Analyze_Subprogram_Renaming;
2406 -------------------------
2407 -- Analyze_Use_Package --
2408 -------------------------
2410 -- Resolve the package names in the use clause, and make all the visible
2411 -- entities defined in the package potentially use-visible. If the package
2412 -- is already in use from a previous use clause, its visible entities are
2413 -- already use-visible. In that case, mark the occurrence as a redundant
2414 -- use. If the package is an open scope, i.e. if the use clause occurs
2415 -- within the package itself, ignore it.
2417 procedure Analyze_Use_Package (N : Node_Id) is
2418 Pack_Name : Node_Id;
2421 -- Start of processing for Analyze_Use_Package
2424 Set_Hidden_By_Use_Clause (N, No_Elist);
2426 -- Use clause is not allowed in a spec of a predefined package
2427 -- declaration except that packages whose file name starts a-n are OK
2428 -- (these are children of Ada.Numerics, and such packages are never
2429 -- loaded by Rtsfind).
2431 if Is_Predefined_File_Name (Unit_File_Name (Current_Sem_Unit))
2432 and then Name_Buffer (1 .. 3) /= "a-n"
2434 Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Declaration
2436 Error_Msg_N ("use clause not allowed in predefined spec", N);
2439 -- Chain clause to list of use clauses in current scope
2441 if Nkind (Parent (N)) /= N_Compilation_Unit then
2442 Chain_Use_Clause (N);
2445 -- Loop through package names to identify referenced packages
2447 Pack_Name := First (Names (N));
2448 while Present (Pack_Name) loop
2449 Analyze (Pack_Name);
2451 if Nkind (Parent (N)) = N_Compilation_Unit
2452 and then Nkind (Pack_Name) = N_Expanded_Name
2458 Pref := Prefix (Pack_Name);
2459 while Nkind (Pref) = N_Expanded_Name loop
2460 Pref := Prefix (Pref);
2463 if Entity (Pref) = Standard_Standard then
2465 ("predefined package Standard cannot appear"
2466 & " in a context clause", Pref);
2474 -- Loop through package names to mark all entities as potentially
2477 Pack_Name := First (Names (N));
2478 while Present (Pack_Name) loop
2479 if Is_Entity_Name (Pack_Name) then
2480 Pack := Entity (Pack_Name);
2482 if Ekind (Pack) /= E_Package
2483 and then Etype (Pack) /= Any_Type
2485 if Ekind (Pack) = E_Generic_Package then
2487 ("a generic package is not allowed in a use clause",
2490 Error_Msg_N ("& is not a usable package", Pack_Name);
2494 if Nkind (Parent (N)) = N_Compilation_Unit then
2495 Check_In_Previous_With_Clause (N, Pack_Name);
2498 if Applicable_Use (Pack_Name) then
2499 Use_One_Package (Pack, N);
2503 -- Report error because name denotes something other than a package
2506 Error_Msg_N ("& is not a package", Pack_Name);
2511 end Analyze_Use_Package;
2513 ----------------------
2514 -- Analyze_Use_Type --
2515 ----------------------
2517 procedure Analyze_Use_Type (N : Node_Id) is
2522 Set_Hidden_By_Use_Clause (N, No_Elist);
2524 -- Chain clause to list of use clauses in current scope
2526 if Nkind (Parent (N)) /= N_Compilation_Unit then
2527 Chain_Use_Clause (N);
2530 Id := First (Subtype_Marks (N));
2531 while Present (Id) loop
2535 if E /= Any_Type then
2538 if Nkind (Parent (N)) = N_Compilation_Unit then
2539 if Nkind (Id) = N_Identifier then
2540 Error_Msg_N ("type is not directly visible", Id);
2542 elsif Is_Child_Unit (Scope (E))
2543 and then Scope (E) /= System_Aux_Id
2545 Check_In_Previous_With_Clause (N, Prefix (Id));
2550 -- If the use_type_clause appears in a compilation unit context,
2551 -- check whether it comes from a unit that may appear in a
2552 -- limited_with_clause, for a better error message.
2554 if Nkind (Parent (N)) = N_Compilation_Unit
2555 and then Nkind (Id) /= N_Identifier
2561 function Mentioned (Nam : Node_Id) return Boolean;
2562 -- Check whether the prefix of expanded name for the type
2563 -- appears in the prefix of some limited_with_clause.
2569 function Mentioned (Nam : Node_Id) return Boolean is
2571 return Nkind (Name (Item)) = N_Selected_Component
2573 Chars (Prefix (Name (Item))) = Chars (Nam);
2577 Pref := Prefix (Id);
2578 Item := First (Context_Items (Parent (N)));
2580 while Present (Item) and then Item /= N loop
2581 if Nkind (Item) = N_With_Clause
2582 and then Limited_Present (Item)
2583 and then Mentioned (Pref)
2586 (Get_Msg_Id, "premature usage of incomplete type");
2597 end Analyze_Use_Type;
2599 --------------------
2600 -- Applicable_Use --
2601 --------------------
2603 function Applicable_Use (Pack_Name : Node_Id) return Boolean is
2604 Pack : constant Entity_Id := Entity (Pack_Name);
2607 if In_Open_Scopes (Pack) then
2608 if Warn_On_Redundant_Constructs
2609 and then Pack = Current_Scope
2612 ("& is already use-visible within itself?", Pack_Name, Pack);
2617 elsif In_Use (Pack) then
2618 Note_Redundant_Use (Pack_Name);
2621 elsif Present (Renamed_Object (Pack))
2622 and then In_Use (Renamed_Object (Pack))
2624 Note_Redundant_Use (Pack_Name);
2632 ------------------------
2633 -- Attribute_Renaming --
2634 ------------------------
2636 procedure Attribute_Renaming (N : Node_Id) is
2637 Loc : constant Source_Ptr := Sloc (N);
2638 Nam : constant Node_Id := Name (N);
2639 Spec : constant Node_Id := Specification (N);
2640 New_S : constant Entity_Id := Defining_Unit_Name (Spec);
2641 Aname : constant Name_Id := Attribute_Name (Nam);
2643 Form_Num : Nat := 0;
2644 Expr_List : List_Id := No_List;
2646 Attr_Node : Node_Id;
2647 Body_Node : Node_Id;
2648 Param_Spec : Node_Id;
2651 Generate_Definition (New_S);
2653 -- This procedure is called in the context of subprogram renaming, and
2654 -- thus the attribute must be one that is a subprogram. All of those
2655 -- have at least one formal parameter, with the singular exception of
2656 -- AST_Entry (which is a real oddity, it is odd that this can be renamed
2659 if not Is_Non_Empty_List (Parameter_Specifications (Spec)) then
2660 if Aname /= Name_AST_Entry then
2662 ("subprogram renaming an attribute must have formals", N);
2667 Param_Spec := First (Parameter_Specifications (Spec));
2668 while Present (Param_Spec) loop
2669 Form_Num := Form_Num + 1;
2671 if Nkind (Parameter_Type (Param_Spec)) /= N_Access_Definition then
2672 Find_Type (Parameter_Type (Param_Spec));
2674 -- The profile of the new entity denotes the base type (s) of
2675 -- the types given in the specification. For access parameters
2676 -- there are no subtypes involved.
2678 Rewrite (Parameter_Type (Param_Spec),
2680 (Base_Type (Entity (Parameter_Type (Param_Spec))), Loc));
2683 if No (Expr_List) then
2684 Expr_List := New_List;
2687 Append_To (Expr_List,
2688 Make_Identifier (Loc,
2689 Chars => Chars (Defining_Identifier (Param_Spec))));
2691 -- The expressions in the attribute reference are not freeze
2692 -- points. Neither is the attribute as a whole, see below.
2694 Set_Must_Not_Freeze (Last (Expr_List));
2699 -- Immediate error if too many formals. Other mismatches in number or
2700 -- types of parameters are detected when we analyze the body of the
2701 -- subprogram that we construct.
2703 if Form_Num > 2 then
2704 Error_Msg_N ("too many formals for attribute", N);
2706 -- Error if the attribute reference has expressions that look like
2707 -- formal parameters.
2709 elsif Present (Expressions (Nam)) then
2710 Error_Msg_N ("illegal expressions in attribute reference", Nam);
2713 Aname = Name_Compose or else
2714 Aname = Name_Exponent or else
2715 Aname = Name_Leading_Part or else
2716 Aname = Name_Pos or else
2717 Aname = Name_Round or else
2718 Aname = Name_Scaling or else
2721 if Nkind (N) = N_Subprogram_Renaming_Declaration
2722 and then Present (Corresponding_Formal_Spec (N))
2725 ("generic actual cannot be attribute involving universal type",
2729 ("attribute involving a universal type cannot be renamed",
2734 -- AST_Entry is an odd case. It doesn't really make much sense to allow
2735 -- it to be renamed, but that's the DEC rule, so we have to do it right.
2736 -- The point is that the AST_Entry call should be made now, and what the
2737 -- function will return is the returned value.
2739 -- Note that there is no Expr_List in this case anyway
2741 if Aname = Name_AST_Entry then
2747 Ent := Make_Defining_Identifier (Loc, New_Internal_Name ('R'));
2750 Make_Object_Declaration (Loc,
2751 Defining_Identifier => Ent,
2752 Object_Definition =>
2753 New_Occurrence_Of (RTE (RE_AST_Handler), Loc),
2755 Constant_Present => True);
2757 Set_Assignment_OK (Decl, True);
2758 Insert_Action (N, Decl);
2759 Attr_Node := Make_Identifier (Loc, Chars (Ent));
2762 -- For all other attributes, we rewrite the attribute node to have
2763 -- a list of expressions corresponding to the subprogram formals.
2764 -- A renaming declaration is not a freeze point, and the analysis of
2765 -- the attribute reference should not freeze the type of the prefix.
2769 Make_Attribute_Reference (Loc,
2770 Prefix => Prefix (Nam),
2771 Attribute_Name => Aname,
2772 Expressions => Expr_List);
2774 Set_Must_Not_Freeze (Attr_Node);
2775 Set_Must_Not_Freeze (Prefix (Nam));
2778 -- Case of renaming a function
2780 if Nkind (Spec) = N_Function_Specification then
2781 if Is_Procedure_Attribute_Name (Aname) then
2782 Error_Msg_N ("attribute can only be renamed as procedure", Nam);
2786 Find_Type (Result_Definition (Spec));
2787 Rewrite (Result_Definition (Spec),
2789 Base_Type (Entity (Result_Definition (Spec))), Loc));
2792 Make_Subprogram_Body (Loc,
2793 Specification => Spec,
2794 Declarations => New_List,
2795 Handled_Statement_Sequence =>
2796 Make_Handled_Sequence_Of_Statements (Loc,
2797 Statements => New_List (
2798 Make_Simple_Return_Statement (Loc,
2799 Expression => Attr_Node))));
2801 -- Case of renaming a procedure
2804 if not Is_Procedure_Attribute_Name (Aname) then
2805 Error_Msg_N ("attribute can only be renamed as function", Nam);
2810 Make_Subprogram_Body (Loc,
2811 Specification => Spec,
2812 Declarations => New_List,
2813 Handled_Statement_Sequence =>
2814 Make_Handled_Sequence_Of_Statements (Loc,
2815 Statements => New_List (Attr_Node)));
2818 -- In case of tagged types we add the body of the generated function to
2819 -- the freezing actions of the type (because in the general case such
2820 -- type is still not frozen). We exclude from this processing generic
2821 -- formal subprograms found in instantiations and AST_Entry renamings.
2823 if not Present (Corresponding_Formal_Spec (N))
2824 and then Etype (Nam) /= RTE (RE_AST_Handler)
2827 P : constant Entity_Id := Prefix (Nam);
2832 if Is_Tagged_Type (Etype (P)) then
2833 Ensure_Freeze_Node (Etype (P));
2834 Append_Freeze_Action (Etype (P), Body_Node);
2836 Rewrite (N, Body_Node);
2838 Set_Etype (New_S, Base_Type (Etype (New_S)));
2842 -- Generic formal subprograms or AST_Handler renaming
2845 Rewrite (N, Body_Node);
2847 Set_Etype (New_S, Base_Type (Etype (New_S)));
2850 if Is_Compilation_Unit (New_S) then
2852 ("a library unit can only rename another library unit", N);
2855 -- We suppress elaboration warnings for the resulting entity, since
2856 -- clearly they are not needed, and more particularly, in the case
2857 -- of a generic formal subprogram, the resulting entity can appear
2858 -- after the instantiation itself, and thus look like a bogus case
2859 -- of access before elaboration.
2861 Set_Suppress_Elaboration_Warnings (New_S);
2863 end Attribute_Renaming;
2865 ----------------------
2866 -- Chain_Use_Clause --
2867 ----------------------
2869 procedure Chain_Use_Clause (N : Node_Id) is
2871 Level : Int := Scope_Stack.Last;
2874 if not Is_Compilation_Unit (Current_Scope)
2875 or else not Is_Child_Unit (Current_Scope)
2877 null; -- Common case
2879 elsif Defining_Entity (Parent (N)) = Current_Scope then
2880 null; -- Common case for compilation unit
2883 -- If declaration appears in some other scope, it must be in some
2884 -- parent unit when compiling a child.
2886 Pack := Defining_Entity (Parent (N));
2887 if not In_Open_Scopes (Pack) then
2888 null; -- default as well
2891 -- Find entry for parent unit in scope stack
2893 while Scope_Stack.Table (Level).Entity /= Pack loop
2899 Set_Next_Use_Clause (N,
2900 Scope_Stack.Table (Level).First_Use_Clause);
2901 Scope_Stack.Table (Level).First_Use_Clause := N;
2902 end Chain_Use_Clause;
2904 ---------------------------
2905 -- Check_Frozen_Renaming --
2906 ---------------------------
2908 procedure Check_Frozen_Renaming (N : Node_Id; Subp : Entity_Id) is
2914 and then not Has_Completion (Subp)
2918 (Parent (Declaration_Node (Subp)), Defining_Entity (N));
2920 if Is_Entity_Name (Name (N)) then
2921 Old_S := Entity (Name (N));
2923 if not Is_Frozen (Old_S)
2924 and then Operating_Mode /= Check_Semantics
2926 Append_Freeze_Action (Old_S, B_Node);
2928 Insert_After (N, B_Node);
2932 if Is_Intrinsic_Subprogram (Old_S)
2933 and then not In_Instance
2936 ("subprogram used in renaming_as_body cannot be intrinsic",
2941 Insert_After (N, B_Node);
2945 end Check_Frozen_Renaming;
2947 -----------------------------------
2948 -- Check_In_Previous_With_Clause --
2949 -----------------------------------
2951 procedure Check_In_Previous_With_Clause
2955 Pack : constant Entity_Id := Entity (Original_Node (Nam));
2960 Item := First (Context_Items (Parent (N)));
2962 while Present (Item)
2965 if Nkind (Item) = N_With_Clause
2967 -- Protect the frontend against previous critical errors
2969 and then Nkind (Name (Item)) /= N_Selected_Component
2970 and then Entity (Name (Item)) = Pack
2974 -- Find root library unit in with_clause
2976 while Nkind (Par) = N_Expanded_Name loop
2977 Par := Prefix (Par);
2980 if Is_Child_Unit (Entity (Original_Node (Par))) then
2982 ("& is not directly visible", Par, Entity (Par));
2991 -- On exit, package is not mentioned in a previous with_clause.
2992 -- Check if its prefix is.
2994 if Nkind (Nam) = N_Expanded_Name then
2995 Check_In_Previous_With_Clause (N, Prefix (Nam));
2997 elsif Pack /= Any_Id then
2998 Error_Msg_NE ("& is not visible", Nam, Pack);
3000 end Check_In_Previous_With_Clause;
3002 ---------------------------------
3003 -- Check_Library_Unit_Renaming --
3004 ---------------------------------
3006 procedure Check_Library_Unit_Renaming (N : Node_Id; Old_E : Entity_Id) is
3010 if Nkind (Parent (N)) /= N_Compilation_Unit then
3013 -- Check for library unit. Note that we used to check for the scope
3014 -- being Standard here, but that was wrong for Standard itself.
3016 elsif not Is_Compilation_Unit (Old_E)
3017 and then not Is_Child_Unit (Old_E)
3019 Error_Msg_N ("renamed unit must be a library unit", Name (N));
3021 -- Entities defined in Standard (operators and boolean literals) cannot
3022 -- be renamed as library units.
3024 elsif Scope (Old_E) = Standard_Standard
3025 and then Sloc (Old_E) = Standard_Location
3027 Error_Msg_N ("renamed unit must be a library unit", Name (N));
3029 elsif Present (Parent_Spec (N))
3030 and then Nkind (Unit (Parent_Spec (N))) = N_Generic_Package_Declaration
3031 and then not Is_Child_Unit (Old_E)
3034 ("renamed unit must be a child unit of generic parent", Name (N));
3036 elsif Nkind (N) in N_Generic_Renaming_Declaration
3037 and then Nkind (Name (N)) = N_Expanded_Name
3038 and then Is_Generic_Instance (Entity (Prefix (Name (N))))
3039 and then Is_Generic_Unit (Old_E)
3042 ("renamed generic unit must be a library unit", Name (N));
3044 elsif Is_Package_Or_Generic_Package (Old_E) then
3046 -- Inherit categorization flags
3048 New_E := Defining_Entity (N);
3049 Set_Is_Pure (New_E, Is_Pure (Old_E));
3050 Set_Is_Preelaborated (New_E, Is_Preelaborated (Old_E));
3051 Set_Is_Remote_Call_Interface (New_E,
3052 Is_Remote_Call_Interface (Old_E));
3053 Set_Is_Remote_Types (New_E, Is_Remote_Types (Old_E));
3054 Set_Is_Shared_Passive (New_E, Is_Shared_Passive (Old_E));
3056 end Check_Library_Unit_Renaming;
3062 procedure End_Scope is
3068 Id := First_Entity (Current_Scope);
3069 while Present (Id) loop
3070 -- An entity in the current scope is not necessarily the first one
3071 -- on its homonym chain. Find its predecessor if any,
3072 -- If it is an internal entity, it will not be in the visibility
3073 -- chain altogether, and there is nothing to unchain.
3075 if Id /= Current_Entity (Id) then
3076 Prev := Current_Entity (Id);
3077 while Present (Prev)
3078 and then Present (Homonym (Prev))
3079 and then Homonym (Prev) /= Id
3081 Prev := Homonym (Prev);
3084 -- Skip to end of loop if Id is not in the visibility chain
3086 if No (Prev) or else Homonym (Prev) /= Id then
3094 Set_Is_Immediately_Visible (Id, False);
3096 Outer := Homonym (Id);
3097 while Present (Outer) and then Scope (Outer) = Current_Scope loop
3098 Outer := Homonym (Outer);
3101 -- Reset homonym link of other entities, but do not modify link
3102 -- between entities in current scope, so that the back-end can have
3103 -- a proper count of local overloadings.
3106 Set_Name_Entity_Id (Chars (Id), Outer);
3108 elsif Scope (Prev) /= Scope (Id) then
3109 Set_Homonym (Prev, Outer);
3116 -- If the scope generated freeze actions, place them before the
3117 -- current declaration and analyze them. Type declarations and
3118 -- the bodies of initialization procedures can generate such nodes.
3119 -- We follow the parent chain until we reach a list node, which is
3120 -- the enclosing list of declarations. If the list appears within
3121 -- a protected definition, move freeze nodes outside the protected
3125 (Scope_Stack.Table (Scope_Stack.Last).Pending_Freeze_Actions)
3129 L : constant List_Id := Scope_Stack.Table
3130 (Scope_Stack.Last).Pending_Freeze_Actions;
3133 if Is_Itype (Current_Scope) then
3134 Decl := Associated_Node_For_Itype (Current_Scope);
3136 Decl := Parent (Current_Scope);
3141 while not (Is_List_Member (Decl))
3142 or else Nkind_In (Parent (Decl), N_Protected_Definition,
3145 Decl := Parent (Decl);
3148 Insert_List_Before_And_Analyze (Decl, L);
3157 ---------------------
3158 -- End_Use_Clauses --
3159 ---------------------
3161 procedure End_Use_Clauses (Clause : Node_Id) is
3165 -- Remove Use_Type clauses first, because they affect the
3166 -- visibility of operators in subsequent used packages.
3169 while Present (U) loop
3170 if Nkind (U) = N_Use_Type_Clause then
3174 Next_Use_Clause (U);
3178 while Present (U) loop
3179 if Nkind (U) = N_Use_Package_Clause then
3180 End_Use_Package (U);
3183 Next_Use_Clause (U);
3185 end End_Use_Clauses;
3187 ---------------------
3188 -- End_Use_Package --
3189 ---------------------
3191 procedure End_Use_Package (N : Node_Id) is
3192 Pack_Name : Node_Id;
3197 function Is_Primitive_Operator
3199 F : Entity_Id) return Boolean;
3200 -- Check whether Op is a primitive operator of a use-visible type
3202 ---------------------------
3203 -- Is_Primitive_Operator --
3204 ---------------------------
3206 function Is_Primitive_Operator
3208 F : Entity_Id) return Boolean
3210 T : constant Entity_Id := Etype (F);
3213 and then Scope (T) = Scope (Op);
3214 end Is_Primitive_Operator;
3216 -- Start of processing for End_Use_Package
3219 Pack_Name := First (Names (N));
3220 while Present (Pack_Name) loop
3222 -- Test that Pack_Name actually denotes a package before processing
3224 if Is_Entity_Name (Pack_Name)
3225 and then Ekind (Entity (Pack_Name)) = E_Package
3227 Pack := Entity (Pack_Name);
3229 if In_Open_Scopes (Pack) then
3232 elsif not Redundant_Use (Pack_Name) then
3233 Set_In_Use (Pack, False);
3234 Set_Current_Use_Clause (Pack, Empty);
3236 Id := First_Entity (Pack);
3237 while Present (Id) loop
3239 -- Preserve use-visibility of operators that are primitive
3240 -- operators of a type that is use-visible through an active
3243 if Nkind (Id) = N_Defining_Operator_Symbol
3245 (Is_Primitive_Operator (Id, First_Formal (Id))
3247 (Present (Next_Formal (First_Formal (Id)))
3249 Is_Primitive_Operator
3250 (Id, Next_Formal (First_Formal (Id)))))
3255 Set_Is_Potentially_Use_Visible (Id, False);
3258 if Is_Private_Type (Id)
3259 and then Present (Full_View (Id))
3261 Set_Is_Potentially_Use_Visible (Full_View (Id), False);
3267 if Present (Renamed_Object (Pack)) then
3268 Set_In_Use (Renamed_Object (Pack), False);
3269 Set_Current_Use_Clause (Renamed_Object (Pack), Empty);
3272 if Chars (Pack) = Name_System
3273 and then Scope (Pack) = Standard_Standard
3274 and then Present_System_Aux
3276 Id := First_Entity (System_Aux_Id);
3277 while Present (Id) loop
3278 Set_Is_Potentially_Use_Visible (Id, False);
3280 if Is_Private_Type (Id)
3281 and then Present (Full_View (Id))
3283 Set_Is_Potentially_Use_Visible (Full_View (Id), False);
3289 Set_In_Use (System_Aux_Id, False);
3293 Set_Redundant_Use (Pack_Name, False);
3300 if Present (Hidden_By_Use_Clause (N)) then
3301 Elmt := First_Elmt (Hidden_By_Use_Clause (N));
3302 while Present (Elmt) loop
3303 Set_Is_Immediately_Visible (Node (Elmt));
3307 Set_Hidden_By_Use_Clause (N, No_Elist);
3309 end End_Use_Package;
3315 procedure End_Use_Type (N : Node_Id) is
3322 Id := First (Subtype_Marks (N));
3323 while Present (Id) loop
3325 -- A call to rtsfind may occur while analyzing a use_type clause,
3326 -- in which case the type marks are not resolved yet, and there is
3327 -- nothing to remove.
3329 if not Is_Entity_Name (Id)
3330 or else No (Entity (Id))
3338 or else From_With_Type (T)
3342 -- Note that the use_Type clause may mention a subtype of the type
3343 -- whose primitive operations have been made visible. Here as
3344 -- elsewhere, it is the base type that matters for visibility.
3346 elsif In_Open_Scopes (Scope (Base_Type (T))) then
3349 elsif not Redundant_Use (Id) then
3350 Set_In_Use (T, False);
3351 Set_In_Use (Base_Type (T), False);
3352 Set_Current_Use_Clause (T, Empty);
3353 Set_Current_Use_Clause (Base_Type (T), Empty);
3354 Op_List := Collect_Primitive_Operations (T);
3356 Elmt := First_Elmt (Op_List);
3357 while Present (Elmt) loop
3358 if Nkind (Node (Elmt)) = N_Defining_Operator_Symbol then
3359 Set_Is_Potentially_Use_Visible (Node (Elmt), False);
3371 ----------------------
3372 -- Find_Direct_Name --
3373 ----------------------
3375 procedure Find_Direct_Name (N : Node_Id) is
3380 Inst : Entity_Id := Empty;
3381 -- Enclosing instance, if any
3383 Homonyms : Entity_Id;
3384 -- Saves start of homonym chain
3386 Nvis_Entity : Boolean;
3387 -- Set True to indicate that there is at least one entity on the homonym
3388 -- chain which, while not visible, is visible enough from the user point
3389 -- of view to warrant an error message of "not visible" rather than
3392 Nvis_Is_Private_Subprg : Boolean := False;
3393 -- Ada 2005 (AI-262): Set True to indicate that a form of Beaujolais
3394 -- effect concerning library subprograms has been detected. Used to
3395 -- generate the precise error message.
3397 function From_Actual_Package (E : Entity_Id) return Boolean;
3398 -- Returns true if the entity is declared in a package that is
3399 -- an actual for a formal package of the current instance. Such an
3400 -- entity requires special handling because it may be use-visible
3401 -- but hides directly visible entities defined outside the instance.
3403 function Is_Actual_Parameter return Boolean;
3404 -- This function checks if the node N is an identifier that is an actual
3405 -- parameter of a procedure call. If so it returns True, otherwise it
3406 -- return False. The reason for this check is that at this stage we do
3407 -- not know what procedure is being called if the procedure might be
3408 -- overloaded, so it is premature to go setting referenced flags or
3409 -- making calls to Generate_Reference. We will wait till Resolve_Actuals
3410 -- for that processing
3412 function Known_But_Invisible (E : Entity_Id) return Boolean;
3413 -- This function determines whether the entity E (which is not
3414 -- visible) can reasonably be considered to be known to the writer
3415 -- of the reference. This is a heuristic test, used only for the
3416 -- purposes of figuring out whether we prefer to complain that an
3417 -- entity is undefined or invisible (and identify the declaration
3418 -- of the invisible entity in the latter case). The point here is
3419 -- that we don't want to complain that something is invisible and
3420 -- then point to something entirely mysterious to the writer.
3422 procedure Nvis_Messages;
3423 -- Called if there are no visible entries for N, but there is at least
3424 -- one non-directly visible, or hidden declaration. This procedure
3425 -- outputs an appropriate set of error messages.
3427 procedure Undefined (Nvis : Boolean);
3428 -- This function is called if the current node has no corresponding
3429 -- visible entity or entities. The value set in Msg indicates whether
3430 -- an error message was generated (multiple error messages for the
3431 -- same variable are generally suppressed, see body for details).
3432 -- Msg is True if an error message was generated, False if not. This
3433 -- value is used by the caller to determine whether or not to output
3434 -- additional messages where appropriate. The parameter is set False
3435 -- to get the message "X is undefined", and True to get the message
3436 -- "X is not visible".
3438 -------------------------
3439 -- From_Actual_Package --
3440 -------------------------
3442 function From_Actual_Package (E : Entity_Id) return Boolean is
3443 Scop : constant Entity_Id := Scope (E);
3447 if not In_Instance then
3450 Inst := Current_Scope;
3451 while Present (Inst)
3452 and then Ekind (Inst) /= E_Package
3453 and then not Is_Generic_Instance (Inst)
3455 Inst := Scope (Inst);
3462 Act := First_Entity (Inst);
3463 while Present (Act) loop
3464 if Ekind (Act) = E_Package then
3466 -- Check for end of actuals list
3468 if Renamed_Object (Act) = Inst then
3471 elsif Present (Associated_Formal_Package (Act))
3472 and then Renamed_Object (Act) = Scop
3474 -- Entity comes from (instance of) formal package
3489 end From_Actual_Package;
3491 -------------------------
3492 -- Is_Actual_Parameter --
3493 -------------------------
3495 function Is_Actual_Parameter return Boolean is
3498 Nkind (N) = N_Identifier
3500 (Nkind (Parent (N)) = N_Procedure_Call_Statement
3502 (Nkind (Parent (N)) = N_Parameter_Association
3503 and then N = Explicit_Actual_Parameter (Parent (N))
3504 and then Nkind (Parent (Parent (N))) =
3505 N_Procedure_Call_Statement));
3506 end Is_Actual_Parameter;
3508 -------------------------
3509 -- Known_But_Invisible --
3510 -------------------------
3512 function Known_But_Invisible (E : Entity_Id) return Boolean is
3513 Fname : File_Name_Type;
3516 -- Entities in Standard are always considered to be known
3518 if Sloc (E) <= Standard_Location then
3521 -- An entity that does not come from source is always considered
3522 -- to be unknown, since it is an artifact of code expansion.
3524 elsif not Comes_From_Source (E) then
3527 -- In gnat internal mode, we consider all entities known
3529 elsif GNAT_Mode then
3533 -- Here we have an entity that is not from package Standard, and
3534 -- which comes from Source. See if it comes from an internal file.
3536 Fname := Unit_File_Name (Get_Source_Unit (E));
3538 -- Case of from internal file
3540 if Is_Internal_File_Name (Fname) then
3542 -- Private part entities in internal files are never considered
3543 -- to be known to the writer of normal application code.
3545 if Is_Hidden (E) then
3549 -- Entities from System packages other than System and
3550 -- System.Storage_Elements are not considered to be known.
3551 -- System.Auxxxx files are also considered known to the user.
3553 -- Should refine this at some point to generally distinguish
3554 -- between known and unknown internal files ???
3556 Get_Name_String (Fname);
3561 Name_Buffer (1 .. 2) /= "s-"
3563 Name_Buffer (3 .. 8) = "stoele"
3565 Name_Buffer (3 .. 5) = "aux";
3567 -- If not an internal file, then entity is definitely known,
3568 -- even if it is in a private part (the message generated will
3569 -- note that it is in a private part)
3574 end Known_But_Invisible;
3580 procedure Nvis_Messages is
3581 Comp_Unit : Node_Id;
3583 Hidden : Boolean := False;
3587 -- Ada 2005 (AI-262): Generate a precise error concerning the
3588 -- Beaujolais effect that was previously detected
3590 if Nvis_Is_Private_Subprg then
3592 pragma Assert (Nkind (E2) = N_Defining_Identifier
3593 and then Ekind (E2) = E_Function
3594 and then Scope (E2) = Standard_Standard
3595 and then Has_Private_With (E2));
3597 -- Find the sloc corresponding to the private with'ed unit
3599 Comp_Unit := Cunit (Current_Sem_Unit);
3600 Error_Msg_Sloc := No_Location;
3602 Item := First (Context_Items (Comp_Unit));
3603 while Present (Item) loop
3604 if Nkind (Item) = N_With_Clause
3605 and then Private_Present (Item)
3606 and then Entity (Name (Item)) = E2
3608 Error_Msg_Sloc := Sloc (Item);
3615 pragma Assert (Error_Msg_Sloc /= No_Location);
3617 Error_Msg_N ("(Ada 2005): hidden by private with clause #", N);
3621 Undefined (Nvis => True);
3625 -- First loop does hidden declarations
3628 while Present (Ent) loop
3629 if Is_Potentially_Use_Visible (Ent) then
3631 Error_Msg_N ("multiple use clauses cause hiding!", N);
3635 Error_Msg_Sloc := Sloc (Ent);
3636 Error_Msg_N ("hidden declaration#!", N);
3639 Ent := Homonym (Ent);
3642 -- If we found hidden declarations, then that's enough, don't
3643 -- bother looking for non-visible declarations as well.
3649 -- Second loop does non-directly visible declarations
3652 while Present (Ent) loop
3653 if not Is_Potentially_Use_Visible (Ent) then
3655 -- Do not bother the user with unknown entities
3657 if not Known_But_Invisible (Ent) then
3661 Error_Msg_Sloc := Sloc (Ent);
3663 -- Output message noting that there is a non-visible
3664 -- declaration, distinguishing the private part case.
3666 if Is_Hidden (Ent) then
3667 Error_Msg_N ("non-visible (private) declaration#!", N);
3669 Error_Msg_N ("non-visible declaration#!", N);
3671 if Is_Compilation_Unit (Ent)
3673 Nkind (Parent (Parent (N))) = N_Use_Package_Clause
3675 Error_Msg_Qual_Level := 99;
3676 Error_Msg_NE ("\\missing `WITH &;`", N, Ent);
3677 Error_Msg_Qual_Level := 0;
3681 -- Set entity and its containing package as referenced. We
3682 -- can't be sure of this, but this seems a better choice
3683 -- to avoid unused entity messages.
3685 if Comes_From_Source (Ent) then
3686 Set_Referenced (Ent);
3687 Set_Referenced (Cunit_Entity (Get_Source_Unit (Ent)));
3692 Ent := Homonym (Ent);
3701 procedure Undefined (Nvis : Boolean) is
3702 Emsg : Error_Msg_Id;
3705 -- We should never find an undefined internal name. If we do, then
3706 -- see if we have previous errors. If so, ignore on the grounds that
3707 -- it is probably a cascaded message (e.g. a block label from a badly
3708 -- formed block). If no previous errors, then we have a real internal
3709 -- error of some kind so raise an exception.
3711 if Is_Internal_Name (Chars (N)) then
3712 if Total_Errors_Detected /= 0 then
3715 raise Program_Error;
3719 -- A very specialized error check, if the undefined variable is
3720 -- a case tag, and the case type is an enumeration type, check
3721 -- for a possible misspelling, and if so, modify the identifier
3723 -- Named aggregate should also be handled similarly ???
3725 if Nkind (N) = N_Identifier
3726 and then Nkind (Parent (N)) = N_Case_Statement_Alternative
3729 Case_Stm : constant Node_Id := Parent (Parent (N));
3730 Case_Typ : constant Entity_Id := Etype (Expression (Case_Stm));
3735 if Is_Enumeration_Type (Case_Typ)
3736 and then not Is_Standard_Character_Type (Case_Typ)
3738 Lit := First_Literal (Case_Typ);
3739 Get_Name_String (Chars (Lit));
3741 if Chars (Lit) /= Chars (N)
3742 and then Is_Bad_Spelling_Of (Chars (N), Chars (Lit)) then
3743 Error_Msg_Node_2 := Lit;
3745 ("& is undefined, assume misspelling of &", N);
3746 Rewrite (N, New_Occurrence_Of (Lit, Sloc (N)));
3750 Lit := Next_Literal (Lit);
3755 -- Normal processing
3757 Set_Entity (N, Any_Id);
3758 Set_Etype (N, Any_Type);
3760 -- We use the table Urefs to keep track of entities for which we
3761 -- have issued errors for undefined references. Multiple errors
3762 -- for a single name are normally suppressed, however we modify
3763 -- the error message to alert the programmer to this effect.
3765 for J in Urefs.First .. Urefs.Last loop
3766 if Chars (N) = Chars (Urefs.Table (J).Node) then
3767 if Urefs.Table (J).Err /= No_Error_Msg
3768 and then Sloc (N) /= Urefs.Table (J).Loc
3770 Error_Msg_Node_1 := Urefs.Table (J).Node;
3772 if Urefs.Table (J).Nvis then
3773 Change_Error_Text (Urefs.Table (J).Err,
3774 "& is not visible (more references follow)");
3776 Change_Error_Text (Urefs.Table (J).Err,
3777 "& is undefined (more references follow)");
3780 Urefs.Table (J).Err := No_Error_Msg;
3783 -- Although we will set Msg False, and thus suppress the
3784 -- message, we also set Error_Posted True, to avoid any
3785 -- cascaded messages resulting from the undefined reference.
3788 Set_Error_Posted (N, True);
3793 -- If entry not found, this is first undefined occurrence
3796 Error_Msg_N ("& is not visible!", N);
3800 Error_Msg_N ("& is undefined!", N);
3803 -- A very bizarre special check, if the undefined identifier
3804 -- is put or put_line, then add a special error message (since
3805 -- this is a very common error for beginners to make).
3807 if Chars (N) = Name_Put or else Chars (N) = Name_Put_Line then
3809 ("\\possible missing `WITH Ada.Text_'I'O; " &
3810 "USE Ada.Text_'I'O`!", N);
3812 -- Another special check if N is the prefix of a selected
3813 -- component which is a known unit, add message complaining
3814 -- about missing with for this unit.
3816 elsif Nkind (Parent (N)) = N_Selected_Component
3817 and then N = Prefix (Parent (N))
3818 and then Is_Known_Unit (Parent (N))
3820 Error_Msg_Node_2 := Selector_Name (Parent (N));
3821 Error_Msg_N ("\\missing `WITH &.&;`", Prefix (Parent (N)));
3824 -- Now check for possible misspellings
3828 Ematch : Entity_Id := Empty;
3830 Last_Name_Id : constant Name_Id :=
3831 Name_Id (Nat (First_Name_Id) +
3832 Name_Entries_Count - 1);
3835 for Nam in First_Name_Id .. Last_Name_Id loop
3836 E := Get_Name_Entity_Id (Nam);
3839 and then (Is_Immediately_Visible (E)
3841 Is_Potentially_Use_Visible (E))
3843 if Is_Bad_Spelling_Of (Chars (N), Nam) then
3850 if Present (Ematch) then
3851 Error_Msg_NE ("\possible misspelling of&", N, Ematch);
3856 -- Make entry in undefined references table unless the full errors
3857 -- switch is set, in which case by refraining from generating the
3858 -- table entry, we guarantee that we get an error message for every
3859 -- undefined reference.
3861 if not All_Errors_Mode then
3872 -- Start of processing for Find_Direct_Name
3875 -- If the entity pointer is already set, this is an internal node, or
3876 -- a node that is analyzed more than once, after a tree modification.
3877 -- In such a case there is no resolution to perform, just set the type.
3879 if Present (Entity (N)) then
3880 if Is_Type (Entity (N)) then
3881 Set_Etype (N, Entity (N));
3885 Entyp : constant Entity_Id := Etype (Entity (N));
3888 -- One special case here. If the Etype field is already set,
3889 -- and references the packed array type corresponding to the
3890 -- etype of the referenced entity, then leave it alone. This
3891 -- happens for trees generated from Exp_Pakd, where expressions
3892 -- can be deliberately "mis-typed" to the packed array type.
3894 if Is_Array_Type (Entyp)
3895 and then Is_Packed (Entyp)
3896 and then Present (Etype (N))
3897 and then Etype (N) = Packed_Array_Type (Entyp)
3901 -- If not that special case, then just reset the Etype
3904 Set_Etype (N, Etype (Entity (N)));
3912 -- Here if Entity pointer was not set, we need full visibility analysis
3913 -- First we generate debugging output if the debug E flag is set.
3915 if Debug_Flag_E then
3916 Write_Str ("Looking for ");
3917 Write_Name (Chars (N));
3921 Homonyms := Current_Entity (N);
3922 Nvis_Entity := False;
3925 while Present (E) loop
3927 -- If entity is immediately visible or potentially use visible, then
3928 -- process the entity and we are done.
3930 if Is_Immediately_Visible (E) then
3931 goto Immediately_Visible_Entity;
3933 elsif Is_Potentially_Use_Visible (E) then
3934 goto Potentially_Use_Visible_Entity;
3936 -- Note if a known but invisible entity encountered
3938 elsif Known_But_Invisible (E) then
3939 Nvis_Entity := True;
3942 -- Move to next entity in chain and continue search
3947 -- If no entries on homonym chain that were potentially visible,
3948 -- and no entities reasonably considered as non-visible, then
3949 -- we have a plain undefined reference, with no additional
3950 -- explanation required!
3952 if not Nvis_Entity then
3953 Undefined (Nvis => False);
3955 -- Otherwise there is at least one entry on the homonym chain that
3956 -- is reasonably considered as being known and non-visible.
3964 -- Processing for a potentially use visible entry found. We must search
3965 -- the rest of the homonym chain for two reasons. First, if there is a
3966 -- directly visible entry, then none of the potentially use-visible
3967 -- entities are directly visible (RM 8.4(10)). Second, we need to check
3968 -- for the case of multiple potentially use-visible entries hiding one
3969 -- another and as a result being non-directly visible (RM 8.4(11)).
3971 <<Potentially_Use_Visible_Entity>> declare
3972 Only_One_Visible : Boolean := True;
3973 All_Overloadable : Boolean := Is_Overloadable (E);
3977 while Present (E2) loop
3978 if Is_Immediately_Visible (E2) then
3980 -- If the use-visible entity comes from the actual for a
3981 -- formal package, it hides a directly visible entity from
3982 -- outside the instance.
3984 if From_Actual_Package (E)
3985 and then Scope_Depth (E2) < Scope_Depth (Inst)
3990 goto Immediately_Visible_Entity;
3993 elsif Is_Potentially_Use_Visible (E2) then
3994 Only_One_Visible := False;
3995 All_Overloadable := All_Overloadable and Is_Overloadable (E2);
3997 -- Ada 2005 (AI-262): Protect against a form of Beaujolais effect
3998 -- that can occur in private_with clauses. Example:
4001 -- private with B; package A is
4002 -- package C is function B return Integer;
4004 -- V1 : Integer := B;
4005 -- private function B return Integer;
4006 -- V2 : Integer := B;
4009 -- V1 resolves to A.B, but V2 resolves to library unit B
4011 elsif Ekind (E2) = E_Function
4012 and then Scope (E2) = Standard_Standard
4013 and then Has_Private_With (E2)
4015 Only_One_Visible := False;
4016 All_Overloadable := False;
4017 Nvis_Is_Private_Subprg := True;
4024 -- On falling through this loop, we have checked that there are no
4025 -- immediately visible entities. Only_One_Visible is set if exactly
4026 -- one potentially use visible entity exists. All_Overloadable is
4027 -- set if all the potentially use visible entities are overloadable.
4028 -- The condition for legality is that either there is one potentially
4029 -- use visible entity, or if there is more than one, then all of them
4030 -- are overloadable.
4032 if Only_One_Visible or All_Overloadable then
4035 -- If there is more than one potentially use-visible entity and at
4036 -- least one of them non-overloadable, we have an error (RM 8.4(11).
4037 -- Note that E points to the first such entity on the homonym list.
4038 -- Special case: if one of the entities is declared in an actual
4039 -- package, it was visible in the generic, and takes precedence over
4040 -- other entities that are potentially use-visible. Same if it is
4041 -- declared in a local instantiation of the current instance.
4046 -- Find current instance
4048 Inst := Current_Scope;
4049 while Present (Inst)
4050 and then Inst /= Standard_Standard
4052 if Is_Generic_Instance (Inst) then
4056 Inst := Scope (Inst);
4060 while Present (E2) loop
4061 if From_Actual_Package (E2)
4063 (Is_Generic_Instance (Scope (E2))
4064 and then Scope_Depth (Scope (E2)) > Scope_Depth (Inst))
4077 Is_Predefined_File_Name (Unit_File_Name (Current_Sem_Unit))
4079 -- A use-clause in the body of a system file creates conflict
4080 -- with some entity in a user scope, while rtsfind is active.
4081 -- Keep only the entity coming from another predefined unit.
4084 while Present (E2) loop
4085 if Is_Predefined_File_Name
4086 (Unit_File_Name (Get_Source_Unit (Sloc (E2))))
4095 -- Entity must exist because predefined unit is correct
4097 raise Program_Error;
4106 -- Come here with E set to the first immediately visible entity on
4107 -- the homonym chain. This is the one we want unless there is another
4108 -- immediately visible entity further on in the chain for an inner
4109 -- scope (RM 8.3(8)).
4111 <<Immediately_Visible_Entity>> declare
4116 -- Find scope level of initial entity. When compiling through
4117 -- Rtsfind, the previous context is not completely invisible, and
4118 -- an outer entity may appear on the chain, whose scope is below
4119 -- the entry for Standard that delimits the current scope stack.
4120 -- Indicate that the level for this spurious entry is outside of
4121 -- the current scope stack.
4123 Level := Scope_Stack.Last;
4125 Scop := Scope_Stack.Table (Level).Entity;
4126 exit when Scop = Scope (E);
4128 exit when Scop = Standard_Standard;
4131 -- Now search remainder of homonym chain for more inner entry
4132 -- If the entity is Standard itself, it has no scope, and we
4133 -- compare it with the stack entry directly.
4136 while Present (E2) loop
4137 if Is_Immediately_Visible (E2) then
4139 -- If a generic package contains a local declaration that
4140 -- has the same name as the generic, there may be a visibility
4141 -- conflict in an instance, where the local declaration must
4142 -- also hide the name of the corresponding package renaming.
4143 -- We check explicitly for a package declared by a renaming,
4144 -- whose renamed entity is an instance that is on the scope
4145 -- stack, and that contains a homonym in the same scope. Once
4146 -- we have found it, we know that the package renaming is not
4147 -- immediately visible, and that the identifier denotes the
4148 -- other entity (and its homonyms if overloaded).
4150 if Scope (E) = Scope (E2)
4151 and then Ekind (E) = E_Package
4152 and then Present (Renamed_Object (E))
4153 and then Is_Generic_Instance (Renamed_Object (E))
4154 and then In_Open_Scopes (Renamed_Object (E))
4155 and then Comes_From_Source (N)
4157 Set_Is_Immediately_Visible (E, False);
4161 for J in Level + 1 .. Scope_Stack.Last loop
4162 if Scope_Stack.Table (J).Entity = Scope (E2)
4163 or else Scope_Stack.Table (J).Entity = E2
4176 -- At the end of that loop, E is the innermost immediately
4177 -- visible entity, so we are all set.
4180 -- Come here with entity found, and stored in E
4184 -- When distribution features are available (Get_PCS_Name /=
4185 -- Name_No_DSA), a remote access-to-subprogram type is converted
4186 -- into a record type holding whatever information is needed to
4187 -- perform a remote call on an RCI subprogram. In that case we
4188 -- rewrite any occurrence of the RAS type into the equivalent record
4189 -- type here. 'Access attribute references and RAS dereferences are
4190 -- then implemented using specific TSSs. However when distribution is
4191 -- not available (case of Get_PCS_Name = Name_No_DSA), we bypass the
4192 -- generation of these TSSs, and we must keep the RAS type in its
4193 -- original access-to-subprogram form (since all calls through a
4194 -- value of such type will be local anyway in the absence of a PCS).
4196 if Comes_From_Source (N)
4197 and then Is_Remote_Access_To_Subprogram_Type (E)
4198 and then Expander_Active
4199 and then Get_PCS_Name /= Name_No_DSA
4202 New_Occurrence_Of (Equivalent_Type (E), Sloc (N)));
4207 -- Why no Style_Check here???
4212 Set_Etype (N, Get_Full_View (Etype (E)));
4215 if Debug_Flag_E then
4216 Write_Str (" found ");
4217 Write_Entity_Info (E, " ");
4220 -- If the Ekind of the entity is Void, it means that all homonyms
4221 -- are hidden from all visibility (RM 8.3(5,14-20)). However, this
4222 -- test is skipped if the current scope is a record and the name is
4223 -- a pragma argument expression (case of Atomic and Volatile pragmas
4224 -- and possibly other similar pragmas added later, which are allowed
4225 -- to reference components in the current record).
4227 if Ekind (E) = E_Void
4229 (not Is_Record_Type (Current_Scope)
4230 or else Nkind (Parent (N)) /= N_Pragma_Argument_Association)
4232 Premature_Usage (N);
4234 -- If the entity is overloadable, collect all interpretations of the
4235 -- name for subsequent overload resolution. We optimize a bit here to
4236 -- do this only if we have an overloadable entity that is not on its
4237 -- own on the homonym chain.
4239 elsif Is_Overloadable (E)
4240 and then (Present (Homonym (E)) or else Current_Entity (N) /= E)
4242 Collect_Interps (N);
4244 -- If no homonyms were visible, the entity is unambiguous
4246 if not Is_Overloaded (N) then
4247 if not Is_Actual_Parameter then
4248 Generate_Reference (E, N);
4252 -- Case of non-overloadable entity, set the entity providing that
4253 -- we do not have the case of a discriminant reference within a
4254 -- default expression. Such references are replaced with the
4255 -- corresponding discriminal, which is the formal corresponding to
4256 -- to the discriminant in the initialization procedure.
4259 -- Entity is unambiguous, indicate that it is referenced here
4261 -- For a renaming of an object, always generate simple reference,
4262 -- we don't try to keep track of assignments in this case.
4264 if Is_Object (E) and then Present (Renamed_Object (E)) then
4265 Generate_Reference (E, N);
4267 -- If the renamed entity is a private protected component,
4268 -- reference the original component as well. This needs to be
4269 -- done because the private renamings are installed before any
4270 -- analysis has occurred. Reference to a private component will
4271 -- resolve to the renaming and the original component will be
4272 -- left unreferenced, hence the following.
4274 if Is_Prival (E) then
4275 Generate_Reference (Prival_Link (E), N);
4278 -- One odd case is that we do not want to set the Referenced flag
4279 -- if the entity is a label, and the identifier is the label in
4280 -- the source, since this is not a reference from the point of
4281 -- view of the user.
4283 elsif Nkind (Parent (N)) = N_Label then
4285 R : constant Boolean := Referenced (E);
4288 -- Generate reference unless this is an actual parameter
4289 -- (see comment below)
4291 if Is_Actual_Parameter then
4292 Generate_Reference (E, N);
4293 Set_Referenced (E, R);
4297 -- Normal case, not a label: generate reference
4299 -- ??? It is too early to generate a reference here even if
4300 -- the entity is unambiguous, because the tree is not
4301 -- sufficiently typed at this point for Generate_Reference to
4302 -- determine whether this reference modifies the denoted object
4303 -- (because implicit dereferences cannot be identified prior to
4304 -- full type resolution).
4306 -- The Is_Actual_Parameter routine takes care of one of these
4307 -- cases but there are others probably ???
4310 if not Is_Actual_Parameter then
4311 Generate_Reference (E, N);
4314 Check_Nested_Access (E);
4317 -- Set Entity, with style check if need be. For a discriminant
4318 -- reference, replace by the corresponding discriminal, i.e. the
4319 -- parameter of the initialization procedure that corresponds to
4320 -- the discriminant. If this replacement is being performed, there
4321 -- is no style check to perform.
4323 -- This replacement must not be done if we are currently
4324 -- processing a generic spec or body, because the discriminal
4325 -- has not been not generated in this case.
4327 -- The replacement is also skipped if we are in special
4328 -- spec-expression mode. Why is this skipped in this case ???
4330 if not In_Spec_Expression
4331 or else Ekind (E) /= E_Discriminant
4332 or else Inside_A_Generic
4334 Set_Entity_With_Style_Check (N, E);
4336 -- The replacement is not done either for a task discriminant that
4337 -- appears in a default expression of an entry parameter. See
4338 -- Expand_Discriminant in exp_ch2 for details on their handling.
4340 elsif Is_Concurrent_Type (Scope (E)) then
4347 and then not Nkind_In (P, N_Parameter_Specification,
4348 N_Component_Declaration)
4354 and then Nkind (P) = N_Parameter_Specification
4358 Set_Entity (N, Discriminal (E));
4362 -- Otherwise, this is a discriminant in a context in which
4363 -- it is a reference to the corresponding parameter of the
4364 -- init proc for the enclosing type.
4367 Set_Entity (N, Discriminal (E));
4371 end Find_Direct_Name;
4373 ------------------------
4374 -- Find_Expanded_Name --
4375 ------------------------
4377 -- This routine searches the homonym chain of the entity until it finds
4378 -- an entity declared in the scope denoted by the prefix. If the entity
4379 -- is private, it may nevertheless be immediately visible, if we are in
4380 -- the scope of its declaration.
4382 procedure Find_Expanded_Name (N : Node_Id) is
4383 Selector : constant Node_Id := Selector_Name (N);
4384 Candidate : Entity_Id := Empty;
4390 P_Name := Entity (Prefix (N));
4393 -- If the prefix is a renamed package, look for the entity in the
4394 -- original package.
4396 if Ekind (P_Name) = E_Package
4397 and then Present (Renamed_Object (P_Name))
4399 P_Name := Renamed_Object (P_Name);
4401 -- Rewrite node with entity field pointing to renamed object
4403 Rewrite (Prefix (N), New_Copy (Prefix (N)));
4404 Set_Entity (Prefix (N), P_Name);
4406 -- If the prefix is an object of a concurrent type, look for
4407 -- the entity in the associated task or protected type.
4409 elsif Is_Concurrent_Type (Etype (P_Name)) then
4410 P_Name := Etype (P_Name);
4413 Id := Current_Entity (Selector);
4416 Is_New_Candidate : Boolean;
4419 while Present (Id) loop
4420 if Scope (Id) = P_Name then
4422 Is_New_Candidate := True;
4424 -- Ada 2005 (AI-217): Handle shadow entities associated with types
4425 -- declared in limited-withed nested packages. We don't need to
4426 -- handle E_Incomplete_Subtype entities because the entities in
4427 -- the limited view are always E_Incomplete_Type entities (see
4428 -- Build_Limited_Views). Regarding the expression used to evaluate
4429 -- the scope, it is important to note that the limited view also
4430 -- has shadow entities associated nested packages. For this reason
4431 -- the correct scope of the entity is the scope of the real entity
4432 -- The non-limited view may itself be incomplete, in which case
4433 -- get the full view if available.
4435 elsif From_With_Type (Id)
4436 and then Is_Type (Id)
4437 and then Ekind (Id) = E_Incomplete_Type
4438 and then Present (Non_Limited_View (Id))
4439 and then Scope (Non_Limited_View (Id)) = P_Name
4441 Candidate := Get_Full_View (Non_Limited_View (Id));
4442 Is_New_Candidate := True;
4445 Is_New_Candidate := False;
4448 if Is_New_Candidate then
4449 if Is_Child_Unit (Id) then
4450 exit when Is_Visible_Child_Unit (Id)
4451 or else Is_Immediately_Visible (Id);
4454 exit when not Is_Hidden (Id)
4455 or else Is_Immediately_Visible (Id);
4464 and then (Ekind (P_Name) = E_Procedure
4466 Ekind (P_Name) = E_Function)
4467 and then Is_Generic_Instance (P_Name)
4469 -- Expanded name denotes entity in (instance of) generic subprogram.
4470 -- The entity may be in the subprogram instance, or may denote one of
4471 -- the formals, which is declared in the enclosing wrapper package.
4473 P_Name := Scope (P_Name);
4475 Id := Current_Entity (Selector);
4476 while Present (Id) loop
4477 exit when Scope (Id) = P_Name;
4482 if No (Id) or else Chars (Id) /= Chars (Selector) then
4483 Set_Etype (N, Any_Type);
4485 -- If we are looking for an entity defined in System, try to find it
4486 -- in the child package that may have been provided as an extension
4487 -- to System. The Extend_System pragma will have supplied the name of
4488 -- the extension, which may have to be loaded.
4490 if Chars (P_Name) = Name_System
4491 and then Scope (P_Name) = Standard_Standard
4492 and then Present (System_Extend_Unit)
4493 and then Present_System_Aux (N)
4495 Set_Entity (Prefix (N), System_Aux_Id);
4496 Find_Expanded_Name (N);
4499 elsif Nkind (Selector) = N_Operator_Symbol
4500 and then Has_Implicit_Operator (N)
4502 -- There is an implicit instance of the predefined operator in
4503 -- the given scope. The operator entity is defined in Standard.
4504 -- Has_Implicit_Operator makes the node into an Expanded_Name.
4508 elsif Nkind (Selector) = N_Character_Literal
4509 and then Has_Implicit_Character_Literal (N)
4511 -- If there is no literal defined in the scope denoted by the
4512 -- prefix, the literal may belong to (a type derived from)
4513 -- Standard_Character, for which we have no explicit literals.
4518 -- If the prefix is a single concurrent object, use its name in
4519 -- the error message, rather than that of the anonymous type.
4521 if Is_Concurrent_Type (P_Name)
4522 and then Is_Internal_Name (Chars (P_Name))
4524 Error_Msg_Node_2 := Entity (Prefix (N));
4526 Error_Msg_Node_2 := P_Name;
4529 if P_Name = System_Aux_Id then
4530 P_Name := Scope (P_Name);
4531 Set_Entity (Prefix (N), P_Name);
4534 if Present (Candidate) then
4536 -- If we know that the unit is a child unit we can give a more
4537 -- accurate error message.
4539 if Is_Child_Unit (Candidate) then
4541 -- If the candidate is a private child unit and we are in
4542 -- the visible part of a public unit, specialize the error
4543 -- message. There might be a private with_clause for it,
4544 -- but it is not currently active.
4546 if Is_Private_Descendant (Candidate)
4547 and then Ekind (Current_Scope) = E_Package
4548 and then not In_Private_Part (Current_Scope)
4549 and then not Is_Private_Descendant (Current_Scope)
4551 Error_Msg_N ("private child unit& is not visible here",
4554 -- Normal case where we have a missing with for a child unit
4557 Error_Msg_Qual_Level := 99;
4558 Error_Msg_NE ("missing `WITH &;`", Selector, Candidate);
4559 Error_Msg_Qual_Level := 0;
4562 -- Here we don't know that this is a child unit
4565 Error_Msg_NE ("& is not a visible entity of&", N, Selector);
4569 -- Within the instantiation of a child unit, the prefix may
4570 -- denote the parent instance, but the selector has the name
4571 -- of the original child. Find whether we are within the
4572 -- corresponding instance, and get the proper entity, which
4573 -- can only be an enclosing scope.
4576 and then In_Open_Scopes (P_Name)
4577 and then Is_Generic_Instance (P_Name)
4580 S : Entity_Id := Current_Scope;
4584 for J in reverse 0 .. Scope_Stack.Last loop
4585 S := Scope_Stack.Table (J).Entity;
4587 exit when S = Standard_Standard;
4589 if Ekind (S) = E_Function
4590 or else Ekind (S) = E_Package
4591 or else Ekind (S) = E_Procedure
4593 P := Generic_Parent (Specification
4594 (Unit_Declaration_Node (S)));
4597 and then Chars (Scope (P)) = Chars (O_Name)
4598 and then Chars (P) = Chars (Selector)
4609 -- If this is a selection from Ada, System or Interfaces, then
4610 -- we assume a missing with for the corresponding package.
4612 if Is_Known_Unit (N) then
4613 if not Error_Posted (N) then
4614 Error_Msg_Node_2 := Selector;
4615 Error_Msg_N ("missing `WITH &.&;`", Prefix (N));
4618 -- If this is a selection from a dummy package, then suppress
4619 -- the error message, of course the entity is missing if the
4620 -- package is missing!
4622 elsif Sloc (Error_Msg_Node_2) = No_Location then
4625 -- Here we have the case of an undefined component
4628 Error_Msg_NE ("& not declared in&", N, Selector);
4630 -- Check for misspelling of some entity in prefix
4632 Id := First_Entity (P_Name);
4633 while Present (Id) loop
4634 if Is_Bad_Spelling_Of (Chars (Id), Chars (Selector))
4635 and then not Is_Internal_Name (Chars (Id))
4638 ("possible misspelling of&", Selector, Id);
4645 -- Specialize the message if this may be an instantiation
4646 -- of a child unit that was not mentioned in the context.
4648 if Nkind (Parent (N)) = N_Package_Instantiation
4649 and then Is_Generic_Instance (Entity (Prefix (N)))
4650 and then Is_Compilation_Unit
4651 (Generic_Parent (Parent (Entity (Prefix (N)))))
4653 Error_Msg_Node_2 := Selector;
4654 Error_Msg_N ("\missing `WITH &.&;`", Prefix (N));
4664 if Comes_From_Source (N)
4665 and then Is_Remote_Access_To_Subprogram_Type (Id)
4666 and then Present (Equivalent_Type (Id))
4668 -- If we are not actually generating distribution code (i.e. the
4669 -- current PCS is the dummy non-distributed version), then the
4670 -- Equivalent_Type will be missing, and Id should be treated as
4671 -- a regular access-to-subprogram type.
4673 Id := Equivalent_Type (Id);
4674 Set_Chars (Selector, Chars (Id));
4677 -- Ada 2005 (AI-50217): Check usage of entities in limited withed units
4679 if Ekind (P_Name) = E_Package
4680 and then From_With_Type (P_Name)
4682 if From_With_Type (Id)
4683 or else Is_Type (Id)
4684 or else Ekind (Id) = E_Package
4689 ("limited withed package can only be used to access "
4690 & "incomplete types",
4695 if Is_Task_Type (P_Name)
4696 and then ((Ekind (Id) = E_Entry
4697 and then Nkind (Parent (N)) /= N_Attribute_Reference)
4699 (Ekind (Id) = E_Entry_Family
4701 Nkind (Parent (Parent (N))) /= N_Attribute_Reference))
4703 -- It is an entry call after all, either to the current task (which
4704 -- will deadlock) or to an enclosing task.
4706 Analyze_Selected_Component (N);
4710 Change_Selected_Component_To_Expanded_Name (N);
4712 -- Do style check and generate reference, but skip both steps if this
4713 -- entity has homonyms, since we may not have the right homonym set yet.
4714 -- The proper homonym will be set during the resolve phase.
4716 if Has_Homonym (Id) then
4719 Set_Entity_With_Style_Check (N, Id);
4720 Generate_Reference (Id, N);
4723 if Is_Type (Id) then
4726 Set_Etype (N, Get_Full_View (Etype (Id)));
4729 -- If the Ekind of the entity is Void, it means that all homonyms are
4730 -- hidden from all visibility (RM 8.3(5,14-20)).
4732 if Ekind (Id) = E_Void then
4733 Premature_Usage (N);
4735 elsif Is_Overloadable (Id)
4736 and then Present (Homonym (Id))
4739 H : Entity_Id := Homonym (Id);
4742 while Present (H) loop
4743 if Scope (H) = Scope (Id)
4746 or else Is_Immediately_Visible (H))
4748 Collect_Interps (N);
4755 -- If an extension of System is present, collect possible explicit
4756 -- overloadings declared in the extension.
4758 if Chars (P_Name) = Name_System
4759 and then Scope (P_Name) = Standard_Standard
4760 and then Present (System_Extend_Unit)
4761 and then Present_System_Aux (N)
4763 H := Current_Entity (Id);
4765 while Present (H) loop
4766 if Scope (H) = System_Aux_Id then
4767 Add_One_Interp (N, H, Etype (H));
4776 if Nkind (Selector_Name (N)) = N_Operator_Symbol
4777 and then Scope (Id) /= Standard_Standard
4779 -- In addition to user-defined operators in the given scope, there
4780 -- may be an implicit instance of the predefined operator. The
4781 -- operator (defined in Standard) is found in Has_Implicit_Operator,
4782 -- and added to the interpretations. Procedure Add_One_Interp will
4783 -- determine which hides which.
4785 if Has_Implicit_Operator (N) then
4789 end Find_Expanded_Name;
4791 -------------------------
4792 -- Find_Renamed_Entity --
4793 -------------------------
4795 function Find_Renamed_Entity
4799 Is_Actual : Boolean := False) return Entity_Id
4802 I1 : Interp_Index := 0; -- Suppress junk warnings
4808 function Enclosing_Instance return Entity_Id;
4809 -- If the renaming determines the entity for the default of a formal
4810 -- subprogram nested within another instance, choose the innermost
4811 -- candidate. This is because if the formal has a box, and we are within
4812 -- an enclosing instance where some candidate interpretations are local
4813 -- to this enclosing instance, we know that the default was properly
4814 -- resolved when analyzing the generic, so we prefer the local
4815 -- candidates to those that are external. This is not always the case
4816 -- but is a reasonable heuristic on the use of nested generics. The
4817 -- proper solution requires a full renaming model.
4819 function Is_Visible_Operation (Op : Entity_Id) return Boolean;
4820 -- If the renamed entity is an implicit operator, check whether it is
4821 -- visible because its operand type is properly visible. This check
4822 -- applies to explicit renamed entities that appear in the source in a
4823 -- renaming declaration or a formal subprogram instance, but not to
4824 -- default generic actuals with a name.
4826 function Report_Overload return Entity_Id;
4827 -- List possible interpretations, and specialize message in the
4828 -- case of a generic actual.
4830 function Within (Inner, Outer : Entity_Id) return Boolean;
4831 -- Determine whether a candidate subprogram is defined within the
4832 -- enclosing instance. If yes, it has precedence over outer candidates.
4834 ------------------------
4835 -- Enclosing_Instance --
4836 ------------------------
4838 function Enclosing_Instance return Entity_Id is
4842 if not Is_Generic_Instance (Current_Scope)
4843 and then not Is_Actual
4848 S := Scope (Current_Scope);
4849 while S /= Standard_Standard loop
4850 if Is_Generic_Instance (S) then
4858 end Enclosing_Instance;
4860 --------------------------
4861 -- Is_Visible_Operation --
4862 --------------------------
4864 function Is_Visible_Operation (Op : Entity_Id) return Boolean is
4870 if Ekind (Op) /= E_Operator
4871 or else Scope (Op) /= Standard_Standard
4872 or else (In_Instance
4875 or else Present (Enclosing_Instance)))
4880 -- For a fixed point type operator, check the resulting type,
4881 -- because it may be a mixed mode integer * fixed operation.
4883 if Present (Next_Formal (First_Formal (New_S)))
4884 and then Is_Fixed_Point_Type (Etype (New_S))
4886 Typ := Etype (New_S);
4888 Typ := Etype (First_Formal (New_S));
4891 Btyp := Base_Type (Typ);
4893 if Nkind (Nam) /= N_Expanded_Name then
4894 return (In_Open_Scopes (Scope (Btyp))
4895 or else Is_Potentially_Use_Visible (Btyp)
4896 or else In_Use (Btyp)
4897 or else In_Use (Scope (Btyp)));
4900 Scop := Entity (Prefix (Nam));
4902 if Ekind (Scop) = E_Package
4903 and then Present (Renamed_Object (Scop))
4905 Scop := Renamed_Object (Scop);
4908 -- Operator is visible if prefix of expanded name denotes
4909 -- scope of type, or else type is defined in System_Aux
4910 -- and the prefix denotes System.
4912 return Scope (Btyp) = Scop
4913 or else (Scope (Btyp) = System_Aux_Id
4914 and then Scope (Scope (Btyp)) = Scop);
4917 end Is_Visible_Operation;
4923 function Within (Inner, Outer : Entity_Id) return Boolean is
4927 Sc := Scope (Inner);
4928 while Sc /= Standard_Standard loop
4939 ---------------------
4940 -- Report_Overload --
4941 ---------------------
4943 function Report_Overload return Entity_Id is
4947 ("ambiguous actual subprogram&, " &
4948 "possible interpretations:", N, Nam);
4951 ("ambiguous subprogram, " &
4952 "possible interpretations:", N);
4955 List_Interps (Nam, N);
4957 end Report_Overload;
4959 -- Start of processing for Find_Renamed_Entry
4963 Candidate_Renaming := Empty;
4965 if not Is_Overloaded (Nam) then
4966 if Entity_Matches_Spec (Entity (Nam), New_S)
4967 and then Is_Visible_Operation (Entity (Nam))
4969 Old_S := Entity (Nam);
4972 Present (First_Formal (Entity (Nam)))
4973 and then Present (First_Formal (New_S))
4974 and then (Base_Type (Etype (First_Formal (Entity (Nam))))
4975 = Base_Type (Etype (First_Formal (New_S))))
4977 Candidate_Renaming := Entity (Nam);
4981 Get_First_Interp (Nam, Ind, It);
4982 while Present (It.Nam) loop
4983 if Entity_Matches_Spec (It.Nam, New_S)
4984 and then Is_Visible_Operation (It.Nam)
4986 if Old_S /= Any_Id then
4988 -- Note: The call to Disambiguate only happens if a
4989 -- previous interpretation was found, in which case I1
4990 -- has received a value.
4992 It1 := Disambiguate (Nam, I1, Ind, Etype (Old_S));
4994 if It1 = No_Interp then
4995 Inst := Enclosing_Instance;
4997 if Present (Inst) then
4998 if Within (It.Nam, Inst) then
5000 elsif Within (Old_S, Inst) then
5003 return Report_Overload;
5007 return Report_Overload;
5021 Present (First_Formal (It.Nam))
5022 and then Present (First_Formal (New_S))
5023 and then (Base_Type (Etype (First_Formal (It.Nam)))
5024 = Base_Type (Etype (First_Formal (New_S))))
5026 Candidate_Renaming := It.Nam;
5029 Get_Next_Interp (Ind, It);
5032 Set_Entity (Nam, Old_S);
5033 Set_Is_Overloaded (Nam, False);
5037 end Find_Renamed_Entity;
5039 -----------------------------
5040 -- Find_Selected_Component --
5041 -----------------------------
5043 procedure Find_Selected_Component (N : Node_Id) is
5044 P : constant Node_Id := Prefix (N);
5047 -- Entity denoted by prefix
5057 if Nkind (P) = N_Error then
5060 -- If the selector already has an entity, the node has been constructed
5061 -- in the course of expansion, and is known to be valid. Do not verify
5062 -- that it is defined for the type (it may be a private component used
5063 -- in the expansion of record equality).
5065 elsif Present (Entity (Selector_Name (N))) then
5067 or else Etype (N) = Any_Type
5070 Sel_Name : constant Node_Id := Selector_Name (N);
5071 Selector : constant Entity_Id := Entity (Sel_Name);
5075 Set_Etype (Sel_Name, Etype (Selector));
5077 if not Is_Entity_Name (P) then
5081 -- Build an actual subtype except for the first parameter
5082 -- of an init proc, where this actual subtype is by
5083 -- definition incorrect, since the object is uninitialized
5084 -- (and does not even have defined discriminants etc.)
5086 if Is_Entity_Name (P)
5087 and then Ekind (Entity (P)) = E_Function
5089 Nam := New_Copy (P);
5091 if Is_Overloaded (P) then
5092 Save_Interps (P, Nam);
5096 Make_Function_Call (Sloc (P), Name => Nam));
5098 Analyze_Selected_Component (N);
5101 elsif Ekind (Selector) = E_Component
5102 and then (not Is_Entity_Name (P)
5103 or else Chars (Entity (P)) /= Name_uInit)
5106 Build_Actual_Subtype_Of_Component (
5107 Etype (Selector), N);
5112 if No (C_Etype) then
5113 C_Etype := Etype (Selector);
5115 Insert_Action (N, C_Etype);
5116 C_Etype := Defining_Identifier (C_Etype);
5119 Set_Etype (N, C_Etype);
5122 -- If this is the name of an entry or protected operation, and
5123 -- the prefix is an access type, insert an explicit dereference,
5124 -- so that entry calls are treated uniformly.
5126 if Is_Access_Type (Etype (P))
5127 and then Is_Concurrent_Type (Designated_Type (Etype (P)))
5130 New_P : constant Node_Id :=
5131 Make_Explicit_Dereference (Sloc (P),
5132 Prefix => Relocate_Node (P));
5135 Set_Etype (P, Designated_Type (Etype (Prefix (P))));
5139 -- If the selected component appears within a default expression
5140 -- and it has an actual subtype, the pre-analysis has not yet
5141 -- completed its analysis, because Insert_Actions is disabled in
5142 -- that context. Within the init proc of the enclosing type we
5143 -- must complete this analysis, if an actual subtype was created.
5145 elsif Inside_Init_Proc then
5147 Typ : constant Entity_Id := Etype (N);
5148 Decl : constant Node_Id := Declaration_Node (Typ);
5150 if Nkind (Decl) = N_Subtype_Declaration
5151 and then not Analyzed (Decl)
5152 and then Is_List_Member (Decl)
5153 and then No (Parent (Decl))
5156 Insert_Action (N, Decl);
5163 elsif Is_Entity_Name (P) then
5164 P_Name := Entity (P);
5166 -- The prefix may denote an enclosing type which is the completion
5167 -- of an incomplete type declaration.
5169 if Is_Type (P_Name) then
5170 Set_Entity (P, Get_Full_View (P_Name));
5171 Set_Etype (P, Entity (P));
5172 P_Name := Entity (P);
5175 P_Type := Base_Type (Etype (P));
5177 if Debug_Flag_E then
5178 Write_Str ("Found prefix type to be ");
5179 Write_Entity_Info (P_Type, " "); Write_Eol;
5182 -- First check for components of a record object (not the
5183 -- result of a call, which is handled below).
5185 if Is_Appropriate_For_Record (P_Type)
5186 and then not Is_Overloadable (P_Name)
5187 and then not Is_Type (P_Name)
5189 -- Selected component of record. Type checking will validate
5190 -- name of selector.
5191 -- ??? could we rewrite an implicit dereference into an explicit
5194 Analyze_Selected_Component (N);
5196 elsif Is_Appropriate_For_Entry_Prefix (P_Type)
5197 and then not In_Open_Scopes (P_Name)
5198 and then (not Is_Concurrent_Type (Etype (P_Name))
5199 or else not In_Open_Scopes (Etype (P_Name)))
5201 -- Call to protected operation or entry. Type checking is
5202 -- needed on the prefix.
5204 Analyze_Selected_Component (N);
5206 elsif (In_Open_Scopes (P_Name)
5207 and then Ekind (P_Name) /= E_Void
5208 and then not Is_Overloadable (P_Name))
5209 or else (Is_Concurrent_Type (Etype (P_Name))
5210 and then In_Open_Scopes (Etype (P_Name)))
5212 -- Prefix denotes an enclosing loop, block, or task, i.e. an
5213 -- enclosing construct that is not a subprogram or accept.
5215 Find_Expanded_Name (N);
5217 elsif Ekind (P_Name) = E_Package then
5218 Find_Expanded_Name (N);
5220 elsif Is_Overloadable (P_Name) then
5222 -- The subprogram may be a renaming (of an enclosing scope) as
5223 -- in the case of the name of the generic within an instantiation.
5225 if (Ekind (P_Name) = E_Procedure
5226 or else Ekind (P_Name) = E_Function)
5227 and then Present (Alias (P_Name))
5228 and then Is_Generic_Instance (Alias (P_Name))
5230 P_Name := Alias (P_Name);
5233 if Is_Overloaded (P) then
5235 -- The prefix must resolve to a unique enclosing construct
5238 Found : Boolean := False;
5243 Get_First_Interp (P, Ind, It);
5244 while Present (It.Nam) loop
5245 if In_Open_Scopes (It.Nam) then
5248 "prefix must be unique enclosing scope", N);
5249 Set_Entity (N, Any_Id);
5250 Set_Etype (N, Any_Type);
5259 Get_Next_Interp (Ind, It);
5264 if In_Open_Scopes (P_Name) then
5265 Set_Entity (P, P_Name);
5266 Set_Is_Overloaded (P, False);
5267 Find_Expanded_Name (N);
5270 -- If no interpretation as an expanded name is possible, it
5271 -- must be a selected component of a record returned by a
5272 -- function call. Reformat prefix as a function call, the rest
5273 -- is done by type resolution. If the prefix is procedure or
5274 -- entry, as is P.X; this is an error.
5276 if Ekind (P_Name) /= E_Function
5277 and then (not Is_Overloaded (P)
5279 Nkind (Parent (N)) = N_Procedure_Call_Statement)
5281 -- Prefix may mention a package that is hidden by a local
5282 -- declaration: let the user know. Scan the full homonym
5283 -- chain, the candidate package may be anywhere on it.
5285 if Present (Homonym (Current_Entity (P_Name))) then
5287 P_Name := Current_Entity (P_Name);
5289 while Present (P_Name) loop
5290 exit when Ekind (P_Name) = E_Package;
5291 P_Name := Homonym (P_Name);
5294 if Present (P_Name) then
5295 Error_Msg_Sloc := Sloc (Entity (Prefix (N)));
5298 ("package& is hidden by declaration#",
5301 Set_Entity (Prefix (N), P_Name);
5302 Find_Expanded_Name (N);
5305 P_Name := Entity (Prefix (N));
5310 ("invalid prefix in selected component&", N, P_Name);
5311 Change_Selected_Component_To_Expanded_Name (N);
5312 Set_Entity (N, Any_Id);
5313 Set_Etype (N, Any_Type);
5316 Nam := New_Copy (P);
5317 Save_Interps (P, Nam);
5319 Make_Function_Call (Sloc (P), Name => Nam));
5321 Analyze_Selected_Component (N);
5325 -- Remaining cases generate various error messages
5328 -- Format node as expanded name, to avoid cascaded errors
5330 Change_Selected_Component_To_Expanded_Name (N);
5331 Set_Entity (N, Any_Id);
5332 Set_Etype (N, Any_Type);
5334 -- Issue error message, but avoid this if error issued already.
5335 -- Use identifier of prefix if one is available.
5337 if P_Name = Any_Id then
5340 elsif Ekind (P_Name) = E_Void then
5341 Premature_Usage (P);
5343 elsif Nkind (P) /= N_Attribute_Reference then
5345 "invalid prefix in selected component&", P);
5347 if Is_Access_Type (P_Type)
5348 and then Ekind (Designated_Type (P_Type)) = E_Incomplete_Type
5351 ("\dereference must not be of an incomplete type " &
5357 "invalid prefix in selected component", P);
5362 -- If prefix is not the name of an entity, it must be an expression,
5363 -- whose type is appropriate for a record. This is determined by
5366 Analyze_Selected_Component (N);
5368 end Find_Selected_Component;
5374 procedure Find_Type (N : Node_Id) is
5384 elsif Nkind (N) = N_Attribute_Reference then
5386 -- Class attribute. This is not valid in Ada 83 mode, but we do not
5387 -- need to enforce that at this point, since the declaration of the
5388 -- tagged type in the prefix would have been flagged already.
5390 if Attribute_Name (N) = Name_Class then
5391 Check_Restriction (No_Dispatch, N);
5392 Find_Type (Prefix (N));
5394 -- Propagate error from bad prefix
5396 if Etype (Prefix (N)) = Any_Type then
5397 Set_Entity (N, Any_Type);
5398 Set_Etype (N, Any_Type);
5402 T := Base_Type (Entity (Prefix (N)));
5404 -- Case where type is not known to be tagged. Its appearance in
5405 -- the prefix of the 'Class attribute indicates that the full view
5408 if not Is_Tagged_Type (T) then
5409 if Ekind (T) = E_Incomplete_Type then
5411 -- It is legal to denote the class type of an incomplete
5412 -- type. The full type will have to be tagged, of course.
5413 -- In Ada 2005 this usage is declared obsolescent, so we
5414 -- warn accordingly.
5416 -- ??? This test is temporarily disabled (always False)
5417 -- because it causes an unwanted warning on GNAT sources
5418 -- (built with -gnatg, which includes Warn_On_Obsolescent_
5419 -- Feature). Once this issue is cleared in the sources, it
5422 if not Is_Tagged_Type (T)
5423 and then Ada_Version >= Ada_05
5424 and then Warn_On_Obsolescent_Feature
5428 ("applying 'Class to an untagged incomplete type"
5429 & " is an obsolescent feature (RM J.11)", N);
5432 Set_Is_Tagged_Type (T);
5433 Set_Primitive_Operations (T, New_Elmt_List);
5434 Make_Class_Wide_Type (T);
5435 Set_Entity (N, Class_Wide_Type (T));
5436 Set_Etype (N, Class_Wide_Type (T));
5438 elsif Ekind (T) = E_Private_Type
5439 and then not Is_Generic_Type (T)
5440 and then In_Private_Part (Scope (T))
5442 -- The Class attribute can be applied to an untagged private
5443 -- type fulfilled by a tagged type prior to the full type
5444 -- declaration (but only within the parent package's private
5445 -- part). Create the class-wide type now and check that the
5446 -- full type is tagged later during its analysis. Note that
5447 -- we do not mark the private type as tagged, unlike the
5448 -- case of incomplete types, because the type must still
5449 -- appear untagged to outside units.
5451 if No (Class_Wide_Type (T)) then
5452 Make_Class_Wide_Type (T);
5455 Set_Entity (N, Class_Wide_Type (T));
5456 Set_Etype (N, Class_Wide_Type (T));
5459 -- Should we introduce a type Any_Tagged and use Wrong_Type
5460 -- here, it would be a bit more consistent???
5463 ("tagged type required, found}",
5464 Prefix (N), First_Subtype (T));
5465 Set_Entity (N, Any_Type);
5469 -- Case of tagged type
5472 if Is_Concurrent_Type (T) then
5473 if No (Corresponding_Record_Type (Entity (Prefix (N)))) then
5475 -- Previous error. Use current type, which at least
5476 -- provides some operations.
5478 C := Entity (Prefix (N));
5481 C := Class_Wide_Type
5482 (Corresponding_Record_Type (Entity (Prefix (N))));
5486 C := Class_Wide_Type (Entity (Prefix (N)));
5489 Set_Entity_With_Style_Check (N, C);
5490 Generate_Reference (C, N);
5494 -- Base attribute, not allowed in Ada 83
5496 elsif Attribute_Name (N) = Name_Base then
5497 if Ada_Version = Ada_83 and then Comes_From_Source (N) then
5499 ("(Ada 83) Base attribute not allowed in subtype mark", N);
5502 Find_Type (Prefix (N));
5503 Typ := Entity (Prefix (N));
5505 if Ada_Version >= Ada_95
5506 and then not Is_Scalar_Type (Typ)
5507 and then not Is_Generic_Type (Typ)
5510 ("prefix of Base attribute must be scalar type",
5513 elsif Sloc (Typ) = Standard_Location
5514 and then Base_Type (Typ) = Typ
5515 and then Warn_On_Redundant_Constructs
5518 ("?redundant attribute, & is its own base type", N, Typ);
5521 T := Base_Type (Typ);
5523 -- Rewrite attribute reference with type itself (see similar
5524 -- processing in Analyze_Attribute, case Base). Preserve
5525 -- prefix if present, for other legality checks.
5527 if Nkind (Prefix (N)) = N_Expanded_Name then
5529 Make_Expanded_Name (Sloc (N),
5531 Prefix => New_Copy (Prefix (Prefix (N))),
5532 Selector_Name => New_Reference_To (T, Sloc (N))));
5535 Rewrite (N, New_Reference_To (T, Sloc (N)));
5542 elsif Attribute_Name (N) = Name_Stub_Type then
5544 -- This is handled in Analyze_Attribute
5548 -- All other attributes are invalid in a subtype mark
5551 Error_Msg_N ("invalid attribute in subtype mark", N);
5557 if Is_Entity_Name (N) then
5558 T_Name := Entity (N);
5560 Error_Msg_N ("subtype mark required in this context", N);
5561 Set_Etype (N, Any_Type);
5565 if T_Name = Any_Id or else Etype (N) = Any_Type then
5567 -- Undefined id. Make it into a valid type
5569 Set_Entity (N, Any_Type);
5571 elsif not Is_Type (T_Name)
5572 and then T_Name /= Standard_Void_Type
5574 Error_Msg_Sloc := Sloc (T_Name);
5575 Error_Msg_N ("subtype mark required in this context", N);
5576 Error_Msg_NE ("\\found & declared#", N, T_Name);
5577 Set_Entity (N, Any_Type);
5580 -- If the type is an incomplete type created to handle
5581 -- anonymous access components of a record type, then the
5582 -- incomplete type is the visible entity and subsequent
5583 -- references will point to it. Mark the original full
5584 -- type as referenced, to prevent spurious warnings.
5586 if Is_Incomplete_Type (T_Name)
5587 and then Present (Full_View (T_Name))
5588 and then not Comes_From_Source (T_Name)
5590 Set_Referenced (Full_View (T_Name));
5593 T_Name := Get_Full_View (T_Name);
5595 -- Ada 2005 (AI-251, AI-50217): Handle interfaces visible through
5596 -- limited-with clauses
5598 if From_With_Type (T_Name)
5599 and then Ekind (T_Name) in Incomplete_Kind
5600 and then Present (Non_Limited_View (T_Name))
5601 and then Is_Interface (Non_Limited_View (T_Name))
5603 T_Name := Non_Limited_View (T_Name);
5606 if In_Open_Scopes (T_Name) then
5607 if Ekind (Base_Type (T_Name)) = E_Task_Type then
5609 -- In Ada 2005, a task name can be used in an access
5610 -- definition within its own body.
5612 if Ada_Version >= Ada_05
5613 and then Nkind (Parent (N)) = N_Access_Definition
5615 Set_Entity (N, T_Name);
5616 Set_Etype (N, T_Name);
5621 ("task type cannot be used as type mark " &
5622 "within its own spec or body", N);
5625 elsif Ekind (Base_Type (T_Name)) = E_Protected_Type then
5627 -- In Ada 2005, a protected name can be used in an access
5628 -- definition within its own body.
5630 if Ada_Version >= Ada_05
5631 and then Nkind (Parent (N)) = N_Access_Definition
5633 Set_Entity (N, T_Name);
5634 Set_Etype (N, T_Name);
5639 ("protected type cannot be used as type mark " &
5640 "within its own spec or body", N);
5644 Error_Msg_N ("type declaration cannot refer to itself", N);
5647 Set_Etype (N, Any_Type);
5648 Set_Entity (N, Any_Type);
5649 Set_Error_Posted (T_Name);
5653 Set_Entity (N, T_Name);
5654 Set_Etype (N, T_Name);
5658 if Present (Etype (N)) and then Comes_From_Source (N) then
5659 if Is_Fixed_Point_Type (Etype (N)) then
5660 Check_Restriction (No_Fixed_Point, N);
5661 elsif Is_Floating_Point_Type (Etype (N)) then
5662 Check_Restriction (No_Floating_Point, N);
5667 ------------------------------------
5668 -- Has_Implicit_Character_Literal --
5669 ------------------------------------
5671 function Has_Implicit_Character_Literal (N : Node_Id) return Boolean is
5673 Found : Boolean := False;
5674 P : constant Entity_Id := Entity (Prefix (N));
5675 Priv_Id : Entity_Id := Empty;
5678 if Ekind (P) = E_Package
5679 and then not In_Open_Scopes (P)
5681 Priv_Id := First_Private_Entity (P);
5684 if P = Standard_Standard then
5685 Change_Selected_Component_To_Expanded_Name (N);
5686 Rewrite (N, Selector_Name (N));
5688 Set_Etype (Original_Node (N), Standard_Character);
5692 Id := First_Entity (P);
5694 and then Id /= Priv_Id
5696 if Is_Standard_Character_Type (Id)
5697 and then Id = Base_Type (Id)
5699 -- We replace the node with the literal itself, resolve as a
5700 -- character, and set the type correctly.
5703 Change_Selected_Component_To_Expanded_Name (N);
5704 Rewrite (N, Selector_Name (N));
5707 Set_Etype (Original_Node (N), Id);
5711 -- More than one type derived from Character in given scope.
5712 -- Collect all possible interpretations.
5714 Add_One_Interp (N, Id, Id);
5722 end Has_Implicit_Character_Literal;
5724 ----------------------
5725 -- Has_Private_With --
5726 ----------------------
5728 function Has_Private_With (E : Entity_Id) return Boolean is
5729 Comp_Unit : constant Node_Id := Cunit (Current_Sem_Unit);
5733 Item := First (Context_Items (Comp_Unit));
5734 while Present (Item) loop
5735 if Nkind (Item) = N_With_Clause
5736 and then Private_Present (Item)
5737 and then Entity (Name (Item)) = E
5746 end Has_Private_With;
5748 ---------------------------
5749 -- Has_Implicit_Operator --
5750 ---------------------------
5752 function Has_Implicit_Operator (N : Node_Id) return Boolean is
5753 Op_Id : constant Name_Id := Chars (Selector_Name (N));
5754 P : constant Entity_Id := Entity (Prefix (N));
5756 Priv_Id : Entity_Id := Empty;
5758 procedure Add_Implicit_Operator
5760 Op_Type : Entity_Id := Empty);
5761 -- Add implicit interpretation to node N, using the type for which a
5762 -- predefined operator exists. If the operator yields a boolean type,
5763 -- the Operand_Type is implicitly referenced by the operator, and a
5764 -- reference to it must be generated.
5766 ---------------------------
5767 -- Add_Implicit_Operator --
5768 ---------------------------
5770 procedure Add_Implicit_Operator
5772 Op_Type : Entity_Id := Empty)
5774 Predef_Op : Entity_Id;
5777 Predef_Op := Current_Entity (Selector_Name (N));
5779 while Present (Predef_Op)
5780 and then Scope (Predef_Op) /= Standard_Standard
5782 Predef_Op := Homonym (Predef_Op);
5785 if Nkind (N) = N_Selected_Component then
5786 Change_Selected_Component_To_Expanded_Name (N);
5789 Add_One_Interp (N, Predef_Op, T);
5791 -- For operators with unary and binary interpretations, add both
5793 if Present (Homonym (Predef_Op)) then
5794 Add_One_Interp (N, Homonym (Predef_Op), T);
5797 -- The node is a reference to a predefined operator, and
5798 -- an implicit reference to the type of its operands.
5800 if Present (Op_Type) then
5801 Generate_Operator_Reference (N, Op_Type);
5803 Generate_Operator_Reference (N, T);
5805 end Add_Implicit_Operator;
5807 -- Start of processing for Has_Implicit_Operator
5810 if Ekind (P) = E_Package
5811 and then not In_Open_Scopes (P)
5813 Priv_Id := First_Private_Entity (P);
5816 Id := First_Entity (P);
5820 -- Boolean operators: an implicit declaration exists if the scope
5821 -- contains a declaration for a derived Boolean type, or for an
5822 -- array of Boolean type.
5824 when Name_Op_And | Name_Op_Not | Name_Op_Or | Name_Op_Xor =>
5825 while Id /= Priv_Id loop
5826 if Valid_Boolean_Arg (Id)
5827 and then Id = Base_Type (Id)
5829 Add_Implicit_Operator (Id);
5836 -- Equality: look for any non-limited type (result is Boolean)
5838 when Name_Op_Eq | Name_Op_Ne =>
5839 while Id /= Priv_Id loop
5841 and then not Is_Limited_Type (Id)
5842 and then Id = Base_Type (Id)
5844 Add_Implicit_Operator (Standard_Boolean, Id);
5851 -- Comparison operators: scalar type, or array of scalar
5853 when Name_Op_Lt | Name_Op_Le | Name_Op_Gt | Name_Op_Ge =>
5854 while Id /= Priv_Id loop
5855 if (Is_Scalar_Type (Id)
5856 or else (Is_Array_Type (Id)
5857 and then Is_Scalar_Type (Component_Type (Id))))
5858 and then Id = Base_Type (Id)
5860 Add_Implicit_Operator (Standard_Boolean, Id);
5867 -- Arithmetic operators: any numeric type
5877 while Id /= Priv_Id loop
5878 if Is_Numeric_Type (Id)
5879 and then Id = Base_Type (Id)
5881 Add_Implicit_Operator (Id);
5888 -- Concatenation: any one-dimensional array type
5890 when Name_Op_Concat =>
5891 while Id /= Priv_Id loop
5892 if Is_Array_Type (Id) and then Number_Dimensions (Id) = 1
5893 and then Id = Base_Type (Id)
5895 Add_Implicit_Operator (Id);
5902 -- What is the others condition here? Should we be using a
5903 -- subtype of Name_Id that would restrict to operators ???
5905 when others => null;
5908 -- If we fall through, then we do not have an implicit operator
5912 end Has_Implicit_Operator;
5914 --------------------
5915 -- In_Open_Scopes --
5916 --------------------
5918 function In_Open_Scopes (S : Entity_Id) return Boolean is
5920 -- Several scope stacks are maintained by Scope_Stack. The base of the
5921 -- currently active scope stack is denoted by the Is_Active_Stack_Base
5922 -- flag in the scope stack entry. Note that the scope stacks used to
5923 -- simply be delimited implicitly by the presence of Standard_Standard
5924 -- at their base, but there now are cases where this is not sufficient
5925 -- because Standard_Standard actually may appear in the middle of the
5926 -- active set of scopes.
5928 for J in reverse 0 .. Scope_Stack.Last loop
5929 if Scope_Stack.Table (J).Entity = S then
5933 -- Check Is_Active_Stack_Base to tell us when to stop, as there are
5934 -- cases where Standard_Standard appears in the middle of the active
5935 -- set of scopes. This affects the declaration and overriding of
5936 -- private inherited operations in instantiations of generic child
5939 exit when Scope_Stack.Table (J).Is_Active_Stack_Base;
5945 -----------------------------
5946 -- Inherit_Renamed_Profile --
5947 -----------------------------
5949 procedure Inherit_Renamed_Profile (New_S : Entity_Id; Old_S : Entity_Id) is
5956 if Ekind (Old_S) = E_Operator then
5957 New_F := First_Formal (New_S);
5959 while Present (New_F) loop
5960 Set_Etype (New_F, Base_Type (Etype (New_F)));
5961 Next_Formal (New_F);
5964 Set_Etype (New_S, Base_Type (Etype (New_S)));
5967 New_F := First_Formal (New_S);
5968 Old_F := First_Formal (Old_S);
5970 while Present (New_F) loop
5971 New_T := Etype (New_F);
5972 Old_T := Etype (Old_F);
5974 -- If the new type is a renaming of the old one, as is the
5975 -- case for actuals in instances, retain its name, to simplify
5976 -- later disambiguation.
5978 if Nkind (Parent (New_T)) = N_Subtype_Declaration
5979 and then Is_Entity_Name (Subtype_Indication (Parent (New_T)))
5980 and then Entity (Subtype_Indication (Parent (New_T))) = Old_T
5984 Set_Etype (New_F, Old_T);
5987 Next_Formal (New_F);
5988 Next_Formal (Old_F);
5991 if Ekind (Old_S) = E_Function
5992 or else Ekind (Old_S) = E_Enumeration_Literal
5994 Set_Etype (New_S, Etype (Old_S));
5997 end Inherit_Renamed_Profile;
6003 procedure Initialize is
6008 -------------------------
6009 -- Install_Use_Clauses --
6010 -------------------------
6012 procedure Install_Use_Clauses
6014 Force_Installation : Boolean := False)
6022 while Present (U) loop
6024 -- Case of USE package
6026 if Nkind (U) = N_Use_Package_Clause then
6027 P := First (Names (U));
6028 while Present (P) loop
6031 if Ekind (Id) = E_Package then
6033 Note_Redundant_Use (P);
6035 elsif Present (Renamed_Object (Id))
6036 and then In_Use (Renamed_Object (Id))
6038 Note_Redundant_Use (P);
6040 elsif Force_Installation or else Applicable_Use (P) then
6041 Use_One_Package (Id, U);
6052 P := First (Subtype_Marks (U));
6053 while Present (P) loop
6054 if not Is_Entity_Name (P)
6055 or else No (Entity (P))
6059 elsif Entity (P) /= Any_Type then
6067 Next_Use_Clause (U);
6069 end Install_Use_Clauses;
6071 -------------------------------------
6072 -- Is_Appropriate_For_Entry_Prefix --
6073 -------------------------------------
6075 function Is_Appropriate_For_Entry_Prefix (T : Entity_Id) return Boolean is
6076 P_Type : Entity_Id := T;
6079 if Is_Access_Type (P_Type) then
6080 P_Type := Designated_Type (P_Type);
6083 return Is_Task_Type (P_Type) or else Is_Protected_Type (P_Type);
6084 end Is_Appropriate_For_Entry_Prefix;
6086 -------------------------------
6087 -- Is_Appropriate_For_Record --
6088 -------------------------------
6090 function Is_Appropriate_For_Record (T : Entity_Id) return Boolean is
6092 function Has_Components (T1 : Entity_Id) return Boolean;
6093 -- Determine if given type has components (i.e. is either a record
6094 -- type or a type that has discriminants).
6096 --------------------
6097 -- Has_Components --
6098 --------------------
6100 function Has_Components (T1 : Entity_Id) return Boolean is
6102 return Is_Record_Type (T1)
6103 or else (Is_Private_Type (T1) and then Has_Discriminants (T1))
6104 or else (Is_Task_Type (T1) and then Has_Discriminants (T1))
6105 or else (Is_Incomplete_Type (T1)
6106 and then From_With_Type (T1)
6107 and then Present (Non_Limited_View (T1))
6108 and then Is_Record_Type
6109 (Get_Full_View (Non_Limited_View (T1))));
6112 -- Start of processing for Is_Appropriate_For_Record
6117 and then (Has_Components (T)
6118 or else (Is_Access_Type (T)
6119 and then Has_Components (Designated_Type (T))));
6120 end Is_Appropriate_For_Record;
6122 ------------------------
6123 -- Note_Redundant_Use --
6124 ------------------------
6126 procedure Note_Redundant_Use (Clause : Node_Id) is
6127 Pack_Name : constant Entity_Id := Entity (Clause);
6128 Cur_Use : constant Node_Id := Current_Use_Clause (Pack_Name);
6129 Decl : constant Node_Id := Parent (Clause);
6131 Prev_Use : Node_Id := Empty;
6132 Redundant : Node_Id := Empty;
6133 -- The Use_Clause which is actually redundant. In the simplest case
6134 -- it is Pack itself, but when we compile a body we install its
6135 -- context before that of its spec, in which case it is the use_clause
6136 -- in the spec that will appear to be redundant, and we want the
6137 -- warning to be placed on the body. Similar complications appear when
6138 -- the redundancy is between a child unit and one of its ancestors.
6141 Set_Redundant_Use (Clause, True);
6143 if not Comes_From_Source (Clause)
6145 or else not Warn_On_Redundant_Constructs
6150 if not Is_Compilation_Unit (Current_Scope) then
6152 -- If the use_clause is in an inner scope, it is made redundant
6153 -- by some clause in the current context, with one exception:
6154 -- If we're compiling a nested package body, and the use_clause
6155 -- comes from the corresponding spec, the clause is not necessarily
6156 -- fully redundant, so we should not warn. If a warning was
6157 -- warranted, it would have been given when the spec was processed.
6159 if Nkind (Parent (Decl)) = N_Package_Specification then
6161 Package_Spec_Entity : constant Entity_Id :=
6162 Defining_Unit_Name (Parent (Decl));
6164 if In_Package_Body (Package_Spec_Entity) then
6170 Redundant := Clause;
6171 Prev_Use := Cur_Use;
6173 elsif Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Body then
6175 Cur_Unit : constant Unit_Number_Type := Get_Source_Unit (Cur_Use);
6176 New_Unit : constant Unit_Number_Type := Get_Source_Unit (Clause);
6180 if Cur_Unit = New_Unit then
6182 -- Redundant clause in same body
6184 Redundant := Clause;
6185 Prev_Use := Cur_Use;
6187 elsif Cur_Unit = Current_Sem_Unit then
6189 -- If the new clause is not in the current unit it has been
6190 -- analyzed first, and it makes the other one redundant.
6191 -- However, if the new clause appears in a subunit, Cur_Unit
6192 -- is still the parent, and in that case the redundant one
6193 -- is the one appearing in the subunit.
6195 if Nkind (Unit (Cunit (New_Unit))) = N_Subunit then
6196 Redundant := Clause;
6197 Prev_Use := Cur_Use;
6199 -- Most common case: redundant clause in body,
6200 -- original clause in spec. Current scope is spec entity.
6205 Unit (Library_Unit (Cunit (Current_Sem_Unit))))
6207 Redundant := Cur_Use;
6211 -- The new clause may appear in an unrelated unit, when
6212 -- the parents of a generic are being installed prior to
6213 -- instantiation. In this case there must be no warning.
6214 -- We detect this case by checking whether the current top
6215 -- of the stack is related to the current compilation.
6217 Scop := Current_Scope;
6218 while Present (Scop)
6219 and then Scop /= Standard_Standard
6221 if Is_Compilation_Unit (Scop)
6222 and then not Is_Child_Unit (Scop)
6226 elsif Scop = Cunit_Entity (Current_Sem_Unit) then
6230 Scop := Scope (Scop);
6233 Redundant := Cur_Use;
6237 elsif New_Unit = Current_Sem_Unit then
6238 Redundant := Clause;
6239 Prev_Use := Cur_Use;
6242 -- Neither is the current unit, so they appear in parent or
6243 -- sibling units. Warning will be emitted elsewhere.
6249 elsif Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Declaration
6250 and then Present (Parent_Spec (Unit (Cunit (Current_Sem_Unit))))
6252 -- Use_clause is in child unit of current unit, and the child
6253 -- unit appears in the context of the body of the parent, so it
6254 -- has been installed first, even though it is the redundant one.
6255 -- Depending on their placement in the context, the visible or the
6256 -- private parts of the two units, either might appear as redundant,
6257 -- but the message has to be on the current unit.
6259 if Get_Source_Unit (Cur_Use) = Current_Sem_Unit then
6260 Redundant := Cur_Use;
6263 Redundant := Clause;
6264 Prev_Use := Cur_Use;
6267 -- If the new use clause appears in the private part of a parent unit
6268 -- it may appear to be redundant w.r.t. a use clause in a child unit,
6269 -- but the previous use clause was needed in the visible part of the
6270 -- child, and no warning should be emitted.
6272 if Nkind (Parent (Decl)) = N_Package_Specification
6274 List_Containing (Decl) = Private_Declarations (Parent (Decl))
6277 Par : constant Entity_Id := Defining_Entity (Parent (Decl));
6278 Spec : constant Node_Id :=
6279 Specification (Unit (Cunit (Current_Sem_Unit)));
6282 if Is_Compilation_Unit (Par)
6283 and then Par /= Cunit_Entity (Current_Sem_Unit)
6284 and then Parent (Cur_Use) = Spec
6286 List_Containing (Cur_Use) = Visible_Declarations (Spec)
6293 -- Finally, if the current use clause is in the context then
6294 -- the clause is redundant when it is nested within the unit.
6296 elsif Nkind (Parent (Cur_Use)) = N_Compilation_Unit
6297 and then Nkind (Parent (Parent (Clause))) /= N_Compilation_Unit
6298 and then Get_Source_Unit (Cur_Use) = Get_Source_Unit (Clause)
6300 Redundant := Clause;
6301 Prev_Use := Cur_Use;
6307 if Present (Redundant) then
6308 Error_Msg_Sloc := Sloc (Prev_Use);
6310 ("& is already use-visible through previous use clause #?",
6311 Redundant, Pack_Name);
6313 end Note_Redundant_Use;
6319 procedure Pop_Scope is
6320 SST : Scope_Stack_Entry renames Scope_Stack.Table (Scope_Stack.Last);
6323 if Debug_Flag_E then
6327 Scope_Suppress := SST.Save_Scope_Suppress;
6328 Local_Suppress_Stack_Top := SST.Save_Local_Suppress_Stack_Top;
6329 Check_Policy_List := SST.Save_Check_Policy_List;
6331 if Debug_Flag_W then
6332 Write_Str ("--> exiting scope: ");
6333 Write_Name (Chars (Current_Scope));
6334 Write_Str (", Depth=");
6335 Write_Int (Int (Scope_Stack.Last));
6339 End_Use_Clauses (SST.First_Use_Clause);
6341 -- If the actions to be wrapped are still there they will get lost
6342 -- causing incomplete code to be generated. It is better to abort in
6343 -- this case (and we do the abort even with assertions off since the
6344 -- penalty is incorrect code generation)
6346 if SST.Actions_To_Be_Wrapped_Before /= No_List
6348 SST.Actions_To_Be_Wrapped_After /= No_List
6353 -- Free last subprogram name if allocated, and pop scope
6355 Free (SST.Last_Subprogram_Name);
6356 Scope_Stack.Decrement_Last;
6363 procedure Push_Scope (S : Entity_Id) is
6367 if Ekind (S) = E_Void then
6370 -- Set scope depth if not a non-concurrent type, and we have not
6371 -- yet set the scope depth. This means that we have the first
6372 -- occurrence of the scope, and this is where the depth is set.
6374 elsif (not Is_Type (S) or else Is_Concurrent_Type (S))
6375 and then not Scope_Depth_Set (S)
6377 if S = Standard_Standard then
6378 Set_Scope_Depth_Value (S, Uint_0);
6380 elsif Is_Child_Unit (S) then
6381 Set_Scope_Depth_Value (S, Uint_1);
6383 elsif not Is_Record_Type (Current_Scope) then
6384 if Ekind (S) = E_Loop then
6385 Set_Scope_Depth_Value (S, Scope_Depth (Current_Scope));
6387 Set_Scope_Depth_Value (S, Scope_Depth (Current_Scope) + 1);
6392 Scope_Stack.Increment_Last;
6395 SST : Scope_Stack_Entry renames Scope_Stack.Table (Scope_Stack.Last);
6399 SST.Save_Scope_Suppress := Scope_Suppress;
6400 SST.Save_Local_Suppress_Stack_Top := Local_Suppress_Stack_Top;
6401 SST.Save_Check_Policy_List := Check_Policy_List;
6403 if Scope_Stack.Last > Scope_Stack.First then
6404 SST.Component_Alignment_Default := Scope_Stack.Table
6405 (Scope_Stack.Last - 1).
6406 Component_Alignment_Default;
6409 SST.Last_Subprogram_Name := null;
6410 SST.Is_Transient := False;
6411 SST.Node_To_Be_Wrapped := Empty;
6412 SST.Pending_Freeze_Actions := No_List;
6413 SST.Actions_To_Be_Wrapped_Before := No_List;
6414 SST.Actions_To_Be_Wrapped_After := No_List;
6415 SST.First_Use_Clause := Empty;
6416 SST.Is_Active_Stack_Base := False;
6417 SST.Previous_Visibility := False;
6420 if Debug_Flag_W then
6421 Write_Str ("--> new scope: ");
6422 Write_Name (Chars (Current_Scope));
6423 Write_Str (", Id=");
6424 Write_Int (Int (Current_Scope));
6425 Write_Str (", Depth=");
6426 Write_Int (Int (Scope_Stack.Last));
6430 -- Deal with copying flags from the previous scope to this one. This
6431 -- is not necessary if either scope is standard, or if the new scope
6434 if S /= Standard_Standard
6435 and then Scope (S) /= Standard_Standard
6436 and then not Is_Child_Unit (S)
6440 if Nkind (E) not in N_Entity then
6444 -- Copy categorization flags from Scope (S) to S, this is not done
6445 -- when Scope (S) is Standard_Standard since propagation is from
6446 -- library unit entity inwards. Copy other relevant attributes as
6447 -- well (Discard_Names in particular).
6449 -- We only propagate inwards for library level entities,
6450 -- inner level subprograms do not inherit the categorization.
6452 if Is_Library_Level_Entity (S) then
6453 Set_Is_Preelaborated (S, Is_Preelaborated (E));
6454 Set_Is_Shared_Passive (S, Is_Shared_Passive (E));
6455 Set_Discard_Names (S, Discard_Names (E));
6456 Set_Suppress_Value_Tracking_On_Call
6457 (S, Suppress_Value_Tracking_On_Call (E));
6458 Set_Categorization_From_Scope (E => S, Scop => E);
6463 ---------------------
6464 -- Premature_Usage --
6465 ---------------------
6467 procedure Premature_Usage (N : Node_Id) is
6468 Kind : constant Node_Kind := Nkind (Parent (Entity (N)));
6469 E : Entity_Id := Entity (N);
6472 -- Within an instance, the analysis of the actual for a formal object
6473 -- does not see the name of the object itself. This is significant only
6474 -- if the object is an aggregate, where its analysis does not do any
6475 -- name resolution on component associations. (see 4717-008). In such a
6476 -- case, look for the visible homonym on the chain.
6479 and then Present (Homonym (E))
6484 and then not In_Open_Scopes (Scope (E))
6491 Set_Etype (N, Etype (E));
6496 if Kind = N_Component_Declaration then
6498 ("component&! cannot be used before end of record declaration", N);
6500 elsif Kind = N_Parameter_Specification then
6502 ("formal parameter&! cannot be used before end of specification",
6505 elsif Kind = N_Discriminant_Specification then
6507 ("discriminant&! cannot be used before end of discriminant part",
6510 elsif Kind = N_Procedure_Specification
6511 or else Kind = N_Function_Specification
6514 ("subprogram&! cannot be used before end of its declaration",
6517 elsif Kind = N_Full_Type_Declaration then
6519 ("type& cannot be used before end of its declaration!", N);
6523 ("object& cannot be used before end of its declaration!", N);
6525 end Premature_Usage;
6527 ------------------------
6528 -- Present_System_Aux --
6529 ------------------------
6531 function Present_System_Aux (N : Node_Id := Empty) return Boolean is
6533 Aux_Name : Unit_Name_Type;
6534 Unum : Unit_Number_Type;
6539 function Find_System (C_Unit : Node_Id) return Entity_Id;
6540 -- Scan context clause of compilation unit to find with_clause
6547 function Find_System (C_Unit : Node_Id) return Entity_Id is
6548 With_Clause : Node_Id;
6551 With_Clause := First (Context_Items (C_Unit));
6552 while Present (With_Clause) loop
6553 if (Nkind (With_Clause) = N_With_Clause
6554 and then Chars (Name (With_Clause)) = Name_System)
6555 and then Comes_From_Source (With_Clause)
6566 -- Start of processing for Present_System_Aux
6569 -- The child unit may have been loaded and analyzed already
6571 if Present (System_Aux_Id) then
6574 -- If no previous pragma for System.Aux, nothing to load
6576 elsif No (System_Extend_Unit) then
6579 -- Use the unit name given in the pragma to retrieve the unit.
6580 -- Verify that System itself appears in the context clause of the
6581 -- current compilation. If System is not present, an error will
6582 -- have been reported already.
6585 With_Sys := Find_System (Cunit (Current_Sem_Unit));
6587 The_Unit := Unit (Cunit (Current_Sem_Unit));
6591 (Nkind (The_Unit) = N_Package_Body
6592 or else (Nkind (The_Unit) = N_Subprogram_Body
6594 not Acts_As_Spec (Cunit (Current_Sem_Unit))))
6596 With_Sys := Find_System (Library_Unit (Cunit (Current_Sem_Unit)));
6600 and then Present (N)
6602 -- If we are compiling a subunit, we need to examine its
6603 -- context as well (Current_Sem_Unit is the parent unit);
6605 The_Unit := Parent (N);
6606 while Nkind (The_Unit) /= N_Compilation_Unit loop
6607 The_Unit := Parent (The_Unit);
6610 if Nkind (Unit (The_Unit)) = N_Subunit then
6611 With_Sys := Find_System (The_Unit);
6615 if No (With_Sys) then
6619 Loc := Sloc (With_Sys);
6620 Get_Name_String (Chars (Expression (System_Extend_Unit)));
6621 Name_Buffer (8 .. Name_Len + 7) := Name_Buffer (1 .. Name_Len);
6622 Name_Buffer (1 .. 7) := "system.";
6623 Name_Buffer (Name_Len + 8) := '%';
6624 Name_Buffer (Name_Len + 9) := 's';
6625 Name_Len := Name_Len + 9;
6626 Aux_Name := Name_Find;
6630 (Load_Name => Aux_Name,
6633 Error_Node => With_Sys);
6635 if Unum /= No_Unit then
6636 Semantics (Cunit (Unum));
6638 Defining_Entity (Specification (Unit (Cunit (Unum))));
6641 Make_With_Clause (Loc,
6643 Make_Expanded_Name (Loc,
6644 Chars => Chars (System_Aux_Id),
6645 Prefix => New_Reference_To (Scope (System_Aux_Id), Loc),
6646 Selector_Name => New_Reference_To (System_Aux_Id, Loc)));
6648 Set_Entity (Name (Withn), System_Aux_Id);
6650 Set_Library_Unit (Withn, Cunit (Unum));
6651 Set_Corresponding_Spec (Withn, System_Aux_Id);
6652 Set_First_Name (Withn, True);
6653 Set_Implicit_With (Withn, True);
6655 Insert_After (With_Sys, Withn);
6656 Mark_Rewrite_Insertion (Withn);
6657 Set_Context_Installed (Withn);
6661 -- Here if unit load failed
6664 Error_Msg_Name_1 := Name_System;
6665 Error_Msg_Name_2 := Chars (Expression (System_Extend_Unit));
6667 ("extension package `%.%` does not exist",
6668 Opt.System_Extend_Unit);
6672 end Present_System_Aux;
6674 -------------------------
6675 -- Restore_Scope_Stack --
6676 -------------------------
6678 procedure Restore_Scope_Stack (Handle_Use : Boolean := True) is
6681 Comp_Unit : Node_Id;
6682 In_Child : Boolean := False;
6683 Full_Vis : Boolean := True;
6684 SS_Last : constant Int := Scope_Stack.Last;
6687 -- Restore visibility of previous scope stack, if any
6689 for J in reverse 0 .. Scope_Stack.Last loop
6690 exit when Scope_Stack.Table (J).Entity = Standard_Standard
6691 or else No (Scope_Stack.Table (J).Entity);
6693 S := Scope_Stack.Table (J).Entity;
6695 if not Is_Hidden_Open_Scope (S) then
6697 -- If the parent scope is hidden, its entities are hidden as
6698 -- well, unless the entity is the instantiation currently
6701 if not Is_Hidden_Open_Scope (Scope (S))
6702 or else not Analyzed (Parent (S))
6703 or else Scope (S) = Standard_Standard
6705 Set_Is_Immediately_Visible (S, True);
6708 E := First_Entity (S);
6709 while Present (E) loop
6710 if Is_Child_Unit (E) then
6711 Set_Is_Immediately_Visible (E,
6712 Is_Visible_Child_Unit (E) or else In_Open_Scopes (E));
6714 Set_Is_Immediately_Visible (E, True);
6720 and then Is_Package_Or_Generic_Package (S)
6722 -- We are in the visible part of the package scope
6724 exit when E = First_Private_Entity (S);
6728 -- The visibility of child units (siblings of current compilation)
6729 -- must be restored in any case. Their declarations may appear
6730 -- after the private part of the parent.
6732 if not Full_Vis then
6733 while Present (E) loop
6734 if Is_Child_Unit (E) then
6735 Set_Is_Immediately_Visible (E,
6736 Is_Visible_Child_Unit (E) or else In_Open_Scopes (E));
6744 if Is_Child_Unit (S)
6745 and not In_Child -- check only for current unit
6749 -- Restore visibility of parents according to whether the child
6750 -- is private and whether we are in its visible part.
6752 Comp_Unit := Parent (Unit_Declaration_Node (S));
6754 if Nkind (Comp_Unit) = N_Compilation_Unit
6755 and then Private_Present (Comp_Unit)
6759 elsif Is_Package_Or_Generic_Package (S)
6760 and then (In_Private_Part (S) or else In_Package_Body (S))
6764 -- if S is the scope of some instance (which has already been
6765 -- seen on the stack) it does not affect the visibility of
6768 elsif Is_Hidden_Open_Scope (S) then
6771 elsif (Ekind (S) = E_Procedure
6772 or else Ekind (S) = E_Function)
6773 and then Has_Completion (S)
6784 if SS_Last >= Scope_Stack.First
6785 and then Scope_Stack.Table (SS_Last).Entity /= Standard_Standard
6788 Install_Use_Clauses (Scope_Stack.Table (SS_Last).First_Use_Clause);
6790 end Restore_Scope_Stack;
6792 ----------------------
6793 -- Save_Scope_Stack --
6794 ----------------------
6796 procedure Save_Scope_Stack (Handle_Use : Boolean := True) is
6799 SS_Last : constant Int := Scope_Stack.Last;
6802 if SS_Last >= Scope_Stack.First
6803 and then Scope_Stack.Table (SS_Last).Entity /= Standard_Standard
6806 End_Use_Clauses (Scope_Stack.Table (SS_Last).First_Use_Clause);
6809 -- If the call is from within a compilation unit, as when called from
6810 -- Rtsfind, make current entries in scope stack invisible while we
6811 -- analyze the new unit.
6813 for J in reverse 0 .. SS_Last loop
6814 exit when Scope_Stack.Table (J).Entity = Standard_Standard
6815 or else No (Scope_Stack.Table (J).Entity);
6817 S := Scope_Stack.Table (J).Entity;
6818 Set_Is_Immediately_Visible (S, False);
6820 E := First_Entity (S);
6821 while Present (E) loop
6822 Set_Is_Immediately_Visible (E, False);
6828 end Save_Scope_Stack;
6834 procedure Set_Use (L : List_Id) is
6836 Pack_Name : Node_Id;
6843 while Present (Decl) loop
6844 if Nkind (Decl) = N_Use_Package_Clause then
6845 Chain_Use_Clause (Decl);
6847 Pack_Name := First (Names (Decl));
6848 while Present (Pack_Name) loop
6849 Pack := Entity (Pack_Name);
6851 if Ekind (Pack) = E_Package
6852 and then Applicable_Use (Pack_Name)
6854 Use_One_Package (Pack, Decl);
6860 elsif Nkind (Decl) = N_Use_Type_Clause then
6861 Chain_Use_Clause (Decl);
6863 Id := First (Subtype_Marks (Decl));
6864 while Present (Id) loop
6865 if Entity (Id) /= Any_Type then
6878 ---------------------
6879 -- Use_One_Package --
6880 ---------------------
6882 procedure Use_One_Package (P : Entity_Id; N : Node_Id) is
6885 Current_Instance : Entity_Id := Empty;
6887 Private_With_OK : Boolean := False;
6890 if Ekind (P) /= E_Package then
6895 Set_Current_Use_Clause (P, N);
6897 -- Ada 2005 (AI-50217): Check restriction
6899 if From_With_Type (P) then
6900 Error_Msg_N ("limited withed package cannot appear in use clause", N);
6903 -- Find enclosing instance, if any
6906 Current_Instance := Current_Scope;
6907 while not Is_Generic_Instance (Current_Instance) loop
6908 Current_Instance := Scope (Current_Instance);
6911 if No (Hidden_By_Use_Clause (N)) then
6912 Set_Hidden_By_Use_Clause (N, New_Elmt_List);
6916 -- If unit is a package renaming, indicate that the renamed
6917 -- package is also in use (the flags on both entities must
6918 -- remain consistent, and a subsequent use of either of them
6919 -- should be recognized as redundant).
6921 if Present (Renamed_Object (P)) then
6922 Set_In_Use (Renamed_Object (P));
6923 Set_Current_Use_Clause (Renamed_Object (P), N);
6924 Real_P := Renamed_Object (P);
6929 -- Ada 2005 (AI-262): Check the use_clause of a private withed package
6930 -- found in the private part of a package specification
6932 if In_Private_Part (Current_Scope)
6933 and then Has_Private_With (P)
6934 and then Is_Child_Unit (Current_Scope)
6935 and then Is_Child_Unit (P)
6936 and then Is_Ancestor_Package (Scope (Current_Scope), P)
6938 Private_With_OK := True;
6941 -- Loop through entities in one package making them potentially
6944 Id := First_Entity (P);
6946 and then (Id /= First_Private_Entity (P)
6947 or else Private_With_OK) -- Ada 2005 (AI-262)
6949 Prev := Current_Entity (Id);
6950 while Present (Prev) loop
6951 if Is_Immediately_Visible (Prev)
6952 and then (not Is_Overloadable (Prev)
6953 or else not Is_Overloadable (Id)
6954 or else (Type_Conformant (Id, Prev)))
6956 if No (Current_Instance) then
6958 -- Potentially use-visible entity remains hidden
6960 goto Next_Usable_Entity;
6962 -- A use clause within an instance hides outer global entities,
6963 -- which are not used to resolve local entities in the
6964 -- instance. Note that the predefined entities in Standard
6965 -- could not have been hidden in the generic by a use clause,
6966 -- and therefore remain visible. Other compilation units whose
6967 -- entities appear in Standard must be hidden in an instance.
6969 -- To determine whether an entity is external to the instance
6970 -- we compare the scope depth of its scope with that of the
6971 -- current instance. However, a generic actual of a subprogram
6972 -- instance is declared in the wrapper package but will not be
6973 -- hidden by a use-visible entity.
6975 -- If Id is called Standard, the predefined package with the
6976 -- same name is in the homonym chain. It has to be ignored
6977 -- because it has no defined scope (being the only entity in
6978 -- the system with this mandated behavior).
6980 elsif not Is_Hidden (Id)
6981 and then Present (Scope (Prev))
6982 and then not Is_Wrapper_Package (Scope (Prev))
6983 and then Scope_Depth (Scope (Prev)) <
6984 Scope_Depth (Current_Instance)
6985 and then (Scope (Prev) /= Standard_Standard
6986 or else Sloc (Prev) > Standard_Location)
6988 Set_Is_Potentially_Use_Visible (Id);
6989 Set_Is_Immediately_Visible (Prev, False);
6990 Append_Elmt (Prev, Hidden_By_Use_Clause (N));
6993 -- A user-defined operator is not use-visible if the predefined
6994 -- operator for the type is immediately visible, which is the case
6995 -- if the type of the operand is in an open scope. This does not
6996 -- apply to user-defined operators that have operands of different
6997 -- types, because the predefined mixed mode operations (multiply
6998 -- and divide) apply to universal types and do not hide anything.
7000 elsif Ekind (Prev) = E_Operator
7001 and then Operator_Matches_Spec (Prev, Id)
7002 and then In_Open_Scopes
7003 (Scope (Base_Type (Etype (First_Formal (Id)))))
7004 and then (No (Next_Formal (First_Formal (Id)))
7005 or else Etype (First_Formal (Id))
7006 = Etype (Next_Formal (First_Formal (Id)))
7007 or else Chars (Prev) = Name_Op_Expon)
7009 goto Next_Usable_Entity;
7012 Prev := Homonym (Prev);
7015 -- On exit, we know entity is not hidden, unless it is private
7017 if not Is_Hidden (Id)
7018 and then ((not Is_Child_Unit (Id))
7019 or else Is_Visible_Child_Unit (Id))
7021 Set_Is_Potentially_Use_Visible (Id);
7023 if Is_Private_Type (Id)
7024 and then Present (Full_View (Id))
7026 Set_Is_Potentially_Use_Visible (Full_View (Id));
7030 <<Next_Usable_Entity>>
7034 -- Child units are also made use-visible by a use clause, but they may
7035 -- appear after all visible declarations in the parent entity list.
7037 while Present (Id) loop
7038 if Is_Child_Unit (Id)
7039 and then Is_Visible_Child_Unit (Id)
7041 Set_Is_Potentially_Use_Visible (Id);
7047 if Chars (Real_P) = Name_System
7048 and then Scope (Real_P) = Standard_Standard
7049 and then Present_System_Aux (N)
7051 Use_One_Package (System_Aux_Id, N);
7054 end Use_One_Package;
7060 procedure Use_One_Type (Id : Node_Id) is
7062 Is_Known_Used : Boolean;
7066 function Spec_Reloaded_For_Body return Boolean;
7067 -- Determine whether the compilation unit is a package body and the use
7068 -- type clause is in the spec of the same package. Even though the spec
7069 -- was analyzed first, its context is reloaded when analysing the body.
7071 ----------------------------
7072 -- Spec_Reloaded_For_Body --
7073 ----------------------------
7075 function Spec_Reloaded_For_Body return Boolean is
7077 if Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Body then
7079 Spec : constant Node_Id :=
7080 Parent (List_Containing (Parent (Id)));
7083 Nkind (Spec) = N_Package_Specification
7084 and then Corresponding_Body (Parent (Spec)) =
7085 Cunit_Entity (Current_Sem_Unit);
7090 end Spec_Reloaded_For_Body;
7092 -- Start of processing for Use_One_Type;
7095 -- It is the type determined by the subtype mark (8.4(8)) whose
7096 -- operations become potentially use-visible.
7098 T := Base_Type (Entity (Id));
7100 -- Either the type itself is used, the package where it is declared
7101 -- is in use or the entity is declared in the current package, thus
7106 or else In_Use (Scope (T))
7107 or else Scope (T) = Current_Scope;
7109 Set_Redundant_Use (Id,
7110 Is_Known_Used or else Is_Potentially_Use_Visible (T));
7112 if Ekind (T) = E_Incomplete_Type then
7113 Error_Msg_N ("premature usage of incomplete type", Id);
7115 elsif In_Open_Scopes (Scope (T)) then
7118 -- A limited view cannot appear in a use_type clause. However, an
7119 -- access type whose designated type is limited has the flag but
7120 -- is not itself a limited view unless we only have a limited view
7121 -- of its enclosing package.
7123 elsif From_With_Type (T)
7124 and then From_With_Type (Scope (T))
7127 ("incomplete type from limited view "
7128 & "cannot appear in use clause", Id);
7130 -- If the subtype mark designates a subtype in a different package,
7131 -- we have to check that the parent type is visible, otherwise the
7132 -- use type clause is a noop. Not clear how to do that???
7134 elsif not Redundant_Use (Id) then
7136 Set_Current_Use_Clause (T, Parent (Id));
7137 Op_List := Collect_Primitive_Operations (T);
7139 Elmt := First_Elmt (Op_List);
7140 while Present (Elmt) loop
7141 if (Nkind (Node (Elmt)) = N_Defining_Operator_Symbol
7142 or else Chars (Node (Elmt)) in Any_Operator_Name)
7143 and then not Is_Hidden (Node (Elmt))
7145 Set_Is_Potentially_Use_Visible (Node (Elmt));
7152 -- If warning on redundant constructs, check for unnecessary WITH
7154 if Warn_On_Redundant_Constructs
7155 and then Is_Known_Used
7157 -- with P; with P; use P;
7158 -- package P is package X is package body X is
7159 -- type T ... use P.T;
7161 -- The compilation unit is the body of X. GNAT first compiles the
7162 -- spec of X, then proceeds to the body. At that point P is marked
7163 -- as use visible. The analysis then reinstalls the spec along with
7164 -- its context. The use clause P.T is now recognized as redundant,
7165 -- but in the wrong context. Do not emit a warning in such cases.
7166 -- Do not emit a warning either if we are in an instance, there
7167 -- is no redundancy between an outer use_clause and one that appears
7168 -- within the generic.
7170 and then not Spec_Reloaded_For_Body
7171 and then not In_Instance
7173 -- The type already has a use clause
7177 -- Case where we know the current use clause for the type
7179 if Present (Current_Use_Clause (T)) then
7180 Use_Clause_Known : declare
7181 Clause1 : constant Node_Id := Parent (Id);
7182 Clause2 : constant Node_Id := Current_Use_Clause (T);
7189 function Entity_Of_Unit (U : Node_Id) return Entity_Id;
7190 -- Return the appropriate entity for determining which unit
7191 -- has a deeper scope: the defining entity for U, unless U
7192 -- is a package instance, in which case we retrieve the
7193 -- entity of the instance spec.
7195 --------------------
7196 -- Entity_Of_Unit --
7197 --------------------
7199 function Entity_Of_Unit (U : Node_Id) return Entity_Id is
7201 if Nkind (U) = N_Package_Instantiation
7202 and then Analyzed (U)
7204 return Defining_Entity (Instance_Spec (U));
7206 return Defining_Entity (U);
7210 -- Start of processing for Use_Clause_Known
7213 -- If both current use type clause and the use type
7214 -- clause for the type are at the compilation unit level,
7215 -- one of the units must be an ancestor of the other, and
7216 -- the warning belongs on the descendant.
7218 if Nkind (Parent (Clause1)) = N_Compilation_Unit
7220 Nkind (Parent (Clause2)) = N_Compilation_Unit
7222 Unit1 := Unit (Parent (Clause1));
7223 Unit2 := Unit (Parent (Clause2));
7225 -- There is a redundant use type clause in a child unit.
7226 -- Determine which of the units is more deeply nested.
7227 -- If a unit is a package instance, retrieve the entity
7228 -- and its scope from the instance spec.
7230 Ent1 := Entity_Of_Unit (Unit1);
7231 Ent2 := Entity_Of_Unit (Unit2);
7233 if Scope (Ent2) = Standard_Standard then
7234 Error_Msg_Sloc := Sloc (Current_Use_Clause (T));
7237 elsif Scope (Ent1) = Standard_Standard then
7238 Error_Msg_Sloc := Sloc (Id);
7241 -- If both units are child units, we determine which one
7242 -- is the descendant by the scope distance to the
7243 -- ultimate parent unit.
7252 while S1 /= Standard_Standard
7254 S2 /= Standard_Standard
7260 if S1 = Standard_Standard then
7261 Error_Msg_Sloc := Sloc (Id);
7264 Error_Msg_Sloc := Sloc (Current_Use_Clause (T));
7271 ("& is already use-visible through previous "
7272 & "use_type_clause #?", Err_No, Id);
7274 -- Case where current use type clause and the use type
7275 -- clause for the type are not both at the compilation unit
7276 -- level. In this case we don't have location information.
7280 ("& is already use-visible through previous "
7281 & "use type clause?", Id, Id);
7283 end Use_Clause_Known;
7285 -- Here if Current_Use_Clause is not set for T, another case
7286 -- where we do not have the location information available.
7290 ("& is already use-visible through previous "
7291 & "use type clause?", Id, Id);
7294 -- The package where T is declared is already used
7296 elsif In_Use (Scope (T)) then
7297 Error_Msg_Sloc := Sloc (Current_Use_Clause (Scope (T)));
7299 ("& is already use-visible through package use clause #?",
7302 -- The current scope is the package where T is declared
7305 Error_Msg_Node_2 := Scope (T);
7307 ("& is already use-visible inside package &?", Id, Id);
7316 procedure Write_Info is
7317 Id : Entity_Id := First_Entity (Current_Scope);
7320 -- No point in dumping standard entities
7322 if Current_Scope = Standard_Standard then
7326 Write_Str ("========================================================");
7328 Write_Str (" Defined Entities in ");
7329 Write_Name (Chars (Current_Scope));
7331 Write_Str ("========================================================");
7335 Write_Str ("-- none --");
7339 while Present (Id) loop
7340 Write_Entity_Info (Id, " ");
7345 if Scope (Current_Scope) = Standard_Standard then
7347 -- Print information on the current unit itself
7349 Write_Entity_Info (Current_Scope, " ");
7359 procedure Write_Scopes is
7362 for J in reverse 1 .. Scope_Stack.Last loop
7363 S := Scope_Stack.Table (J).Entity;
7364 Write_Int (Int (S));
7365 Write_Str (" === ");
7366 Write_Name (Chars (S));