1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2007, 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 Nlists; use Nlists;
41 with Nmake; use Nmake;
43 with Output; use Output;
44 with Restrict; use Restrict;
45 with Rident; use Rident;
46 with Rtsfind; use Rtsfind;
48 with Sem_Cat; use Sem_Cat;
49 with Sem_Ch3; use Sem_Ch3;
50 with Sem_Ch4; use Sem_Ch4;
51 with Sem_Ch6; use Sem_Ch6;
52 with Sem_Ch12; use Sem_Ch12;
53 with Sem_Disp; use Sem_Disp;
54 with Sem_Dist; use Sem_Dist;
55 with Sem_Res; use Sem_Res;
56 with Sem_Util; use Sem_Util;
57 with Sem_Type; use Sem_Type;
58 with Stand; use Stand;
59 with Sinfo; use Sinfo;
60 with Sinfo.CN; use Sinfo.CN;
61 with Snames; use Snames;
62 with Style; use Style;
64 with Tbuild; use Tbuild;
65 with Uintp; use Uintp;
67 with GNAT.Spelling_Checker; use GNAT.Spelling_Checker;
69 package body Sem_Ch8 is
71 ------------------------------------
72 -- Visibility and Name Resolution --
73 ------------------------------------
75 -- This package handles name resolution and the collection of
76 -- interpretations for overloaded names, prior to overload resolution.
78 -- Name resolution is the process that establishes a mapping between source
79 -- identifiers and the entities they denote at each point in the program.
80 -- Each entity is represented by a defining occurrence. Each identifier
81 -- that denotes an entity points to the corresponding defining occurrence.
82 -- This is the entity of the applied occurrence. Each occurrence holds
83 -- an index into the names table, where source identifiers are stored.
85 -- Each entry in the names table for an identifier or designator uses the
86 -- Info pointer to hold a link to the currently visible entity that has
87 -- this name (see subprograms Get_Name_Entity_Id and Set_Name_Entity_Id
88 -- in package Sem_Util). The visibility is initialized at the beginning of
89 -- semantic processing to make entities in package Standard immediately
90 -- visible. The visibility table is used in a more subtle way when
91 -- compiling subunits (see below).
93 -- Entities that have the same name (i.e. homonyms) are chained. In the
94 -- case of overloaded entities, this chain holds all the possible meanings
95 -- of a given identifier. The process of overload resolution uses type
96 -- information to select from this chain the unique meaning of a given
99 -- Entities are also chained in their scope, through the Next_Entity link.
100 -- As a consequence, the name space is organized as a sparse matrix, where
101 -- each row corresponds to a scope, and each column to a source identifier.
102 -- Open scopes, that is to say scopes currently being compiled, have their
103 -- corresponding rows of entities in order, innermost scope first.
105 -- The scopes of packages that are mentioned in context clauses appear in
106 -- no particular order, interspersed among open scopes. This is because
107 -- in the course of analyzing the context of a compilation, a package
108 -- declaration is first an open scope, and subsequently an element of the
109 -- context. If subunits or child units are present, a parent unit may
110 -- appear under various guises at various times in the compilation.
112 -- When the compilation of the innermost scope is complete, the entities
113 -- defined therein are no longer visible. If the scope is not a package
114 -- declaration, these entities are never visible subsequently, and can be
115 -- removed from visibility chains. If the scope is a package declaration,
116 -- its visible declarations may still be accessible. Therefore the entities
117 -- defined in such a scope are left on the visibility chains, and only
118 -- their visibility (immediately visibility or potential use-visibility)
121 -- The ordering of homonyms on their chain does not necessarily follow
122 -- the order of their corresponding scopes on the scope stack. For
123 -- example, if package P and the enclosing scope both contain entities
124 -- named E, then when compiling the package body the chain for E will
125 -- hold the global entity first, and the local one (corresponding to
126 -- the current inner scope) next. As a result, name resolution routines
127 -- do not assume any relative ordering of the homonym chains, either
128 -- for scope nesting or to order of appearance of context clauses.
130 -- When compiling a child unit, entities in the parent scope are always
131 -- immediately visible. When compiling the body of a child unit, private
132 -- entities in the parent must also be made immediately visible. There
133 -- are separate routines to make the visible and private declarations
134 -- visible at various times (see package Sem_Ch7).
136 -- +--------+ +-----+
137 -- | In use |-------->| EU1 |-------------------------->
138 -- +--------+ +-----+
140 -- +--------+ +-----+ +-----+
141 -- | Stand. |---------------->| ES1 |--------------->| ES2 |--->
142 -- +--------+ +-----+ +-----+
144 -- +---------+ | +-----+
145 -- | with'ed |------------------------------>| EW2 |--->
146 -- +---------+ | +-----+
148 -- +--------+ +-----+ +-----+
149 -- | Scope2 |---------------->| E12 |--------------->| E22 |--->
150 -- +--------+ +-----+ +-----+
152 -- +--------+ +-----+ +-----+
153 -- | Scope1 |---------------->| E11 |--------------->| E12 |--->
154 -- +--------+ +-----+ +-----+
158 -- | | with'ed |----------------------------------------->
162 -- (innermost first) | |
163 -- +----------------------------+
164 -- Names table => | Id1 | | | | Id2 |
165 -- +----------------------------+
167 -- Name resolution must deal with several syntactic forms: simple names,
168 -- qualified names, indexed names, and various forms of calls.
170 -- Each identifier points to an entry in the names table. The resolution
171 -- of a simple name consists in traversing the homonym chain, starting
172 -- from the names table. If an entry is immediately visible, it is the one
173 -- designated by the identifier. If only potentially use-visible entities
174 -- are on the chain, we must verify that they do not hide each other. If
175 -- the entity we find is overloadable, we collect all other overloadable
176 -- entities on the chain as long as they are not hidden.
178 -- To resolve expanded names, we must find the entity at the intersection
179 -- of the entity chain for the scope (the prefix) and the homonym chain
180 -- for the selector. In general, homonym chains will be much shorter than
181 -- entity chains, so it is preferable to start from the names table as
182 -- well. If the entity found is overloadable, we must collect all other
183 -- interpretations that are defined in the scope denoted by the prefix.
185 -- For records, protected types, and tasks, their local entities are
186 -- removed from visibility chains on exit from the corresponding scope.
187 -- From the outside, these entities are always accessed by selected
188 -- notation, and the entity chain for the record type, protected type,
189 -- etc. is traversed sequentially in order to find the designated entity.
191 -- The discriminants of a type and the operations of a protected type or
192 -- task are unchained on exit from the first view of the type, (such as
193 -- a private or incomplete type declaration, or a protected type speci-
194 -- fication) and re-chained when compiling the second view.
196 -- In the case of operators, we do not make operators on derived types
197 -- explicit. As a result, the notation P."+" may denote either a user-
198 -- defined function with name "+", or else an implicit declaration of the
199 -- operator "+" in package P. The resolution of expanded names always
200 -- tries to resolve an operator name as such an implicitly defined entity,
201 -- in addition to looking for explicit declarations.
203 -- All forms of names that denote entities (simple names, expanded names,
204 -- character literals in some cases) have a Entity attribute, which
205 -- identifies the entity denoted by the name.
207 ---------------------
208 -- The Scope Stack --
209 ---------------------
211 -- The Scope stack keeps track of the scopes currently been compiled.
212 -- Every entity that contains declarations (including records) is placed
213 -- on the scope stack while it is being processed, and removed at the end.
214 -- Whenever a non-package scope is exited, the entities defined therein
215 -- are removed from the visibility table, so that entities in outer scopes
216 -- become visible (see previous description). On entry to Sem, the scope
217 -- stack only contains the package Standard. As usual, subunits complicate
218 -- this picture ever so slightly.
220 -- The Rtsfind mechanism can force a call to Semantics while another
221 -- compilation is in progress. The unit retrieved by Rtsfind must be
222 -- compiled in its own context, and has no access to the visibility of
223 -- the unit currently being compiled. The procedures Save_Scope_Stack and
224 -- Restore_Scope_Stack make entities in current open scopes invisible
225 -- before compiling the retrieved unit, and restore the compilation
226 -- environment afterwards.
228 ------------------------
229 -- Compiling subunits --
230 ------------------------
232 -- Subunits must be compiled in the environment of the corresponding stub,
233 -- that is to say with the same visibility into the parent (and its
234 -- context) that is available at the point of the stub declaration, but
235 -- with the additional visibility provided by the context clause of the
236 -- subunit itself. As a result, compilation of a subunit forces compilation
237 -- of the parent (see description in lib-). At the point of the stub
238 -- declaration, Analyze is called recursively to compile the proper body of
239 -- the subunit, but without reinitializing the names table, nor the scope
240 -- stack (i.e. standard is not pushed on the stack). In this fashion the
241 -- context of the subunit is added to the context of the parent, and the
242 -- subunit is compiled in the correct environment. Note that in the course
243 -- of processing the context of a subunit, Standard will appear twice on
244 -- the scope stack: once for the parent of the subunit, and once for the
245 -- unit in the context clause being compiled. However, the two sets of
246 -- entities are not linked by homonym chains, so that the compilation of
247 -- any context unit happens in a fresh visibility environment.
249 -------------------------------
250 -- Processing of USE Clauses --
251 -------------------------------
253 -- Every defining occurrence has a flag indicating if it is potentially use
254 -- visible. Resolution of simple names examines this flag. The processing
255 -- of use clauses consists in setting this flag on all visible entities
256 -- defined in the corresponding package. On exit from the scope of the use
257 -- clause, the corresponding flag must be reset. However, a package may
258 -- appear in several nested use clauses (pathological but legal, alas!)
259 -- which forces us to use a slightly more involved scheme:
261 -- a) The defining occurrence for a package holds a flag -In_Use- to
262 -- indicate that it is currently in the scope of a use clause. If a
263 -- redundant use clause is encountered, then the corresponding occurrence
264 -- of the package name is flagged -Redundant_Use-.
266 -- b) On exit from a scope, the use clauses in its declarative part are
267 -- scanned. The visibility flag is reset in all entities declared in
268 -- package named in a use clause, as long as the package is not flagged
269 -- as being in a redundant use clause (in which case the outer use
270 -- clause is still in effect, and the direct visibility of its entities
271 -- must be retained).
273 -- Note that entities are not removed from their homonym chains on exit
274 -- from the package specification. A subsequent use clause does not need
275 -- to rechain the visible entities, but only to establish their direct
278 -----------------------------------
279 -- Handling private declarations --
280 -----------------------------------
282 -- The principle that each entity has a single defining occurrence clashes
283 -- with the presence of two separate definitions for private types: the
284 -- first is the private type declaration, and second is the full type
285 -- declaration. It is important that all references to the type point to
286 -- the same defining occurrence, namely the first one. To enforce the two
287 -- separate views of the entity, the corresponding information is swapped
288 -- between the two declarations. Outside of the package, the defining
289 -- occurrence only contains the private declaration information, while in
290 -- the private part and the body of the package the defining occurrence
291 -- contains the full declaration. To simplify the swap, the defining
292 -- occurrence that currently holds the private declaration points to the
293 -- full declaration. During semantic processing the defining occurrence
294 -- also points to a list of private dependents, that is to say access types
295 -- or composite types whose designated types or component types are
296 -- subtypes or derived types of the private type in question. After the
297 -- full declaration has been seen, the private dependents are updated to
298 -- indicate that they have full definitions.
300 ------------------------------------
301 -- Handling of Undefined Messages --
302 ------------------------------------
304 -- In normal mode, only the first use of an undefined identifier generates
305 -- a message. The table Urefs is used to record error messages that have
306 -- been issued so that second and subsequent ones do not generate further
307 -- messages. However, the second reference causes text to be added to the
308 -- original undefined message noting "(more references follow)". The
309 -- full error list option (-gnatf) forces messages to be generated for
310 -- every reference and disconnects the use of this table.
312 type Uref_Entry is record
314 -- Node for identifier for which original message was posted. The
315 -- Chars field of this identifier is used to detect later references
316 -- to the same identifier.
319 -- Records error message Id of original undefined message. Reset to
320 -- No_Error_Msg after the second occurrence, where it is used to add
321 -- text to the original message as described above.
324 -- Set if the message is not visible rather than undefined
327 -- Records location of error message. Used to make sure that we do
328 -- not consider a, b : undefined as two separate instances, which
329 -- would otherwise happen, since the parser converts this sequence
330 -- to a : undefined; b : undefined.
334 package Urefs is new Table.Table (
335 Table_Component_Type => Uref_Entry,
336 Table_Index_Type => Nat,
337 Table_Low_Bound => 1,
339 Table_Increment => 100,
340 Table_Name => "Urefs");
342 Candidate_Renaming : Entity_Id;
343 -- Holds a candidate interpretation that appears in a subprogram renaming
344 -- declaration and does not match the given specification, but matches at
345 -- least on the first formal. Allows better error message when given
346 -- specification omits defaulted parameters, a common error.
348 -----------------------
349 -- Local Subprograms --
350 -----------------------
352 procedure Analyze_Generic_Renaming
355 -- Common processing for all three kinds of generic renaming declarations.
356 -- Enter new name and indicate that it renames the generic unit.
358 procedure Analyze_Renamed_Character
362 -- Renamed entity is given by a character literal, which must belong
363 -- to the return type of the new entity. Is_Body indicates whether the
364 -- declaration is a renaming_as_body. If the original declaration has
365 -- already been frozen (because of an intervening body, e.g.) the body of
366 -- the function must be built now. The same applies to the following
367 -- various renaming procedures.
369 procedure Analyze_Renamed_Dereference
373 -- Renamed entity is given by an explicit dereference. Prefix must be a
374 -- conformant access_to_subprogram type.
376 procedure Analyze_Renamed_Entry
380 -- If the renamed entity in a subprogram renaming is an entry or protected
381 -- subprogram, build a body for the new entity whose only statement is a
382 -- call to the renamed entity.
384 procedure Analyze_Renamed_Family_Member
388 -- Used when the renamed entity is an indexed component. The prefix must
389 -- denote an entry family.
391 function Applicable_Use (Pack_Name : Node_Id) return Boolean;
392 -- Common code to Use_One_Package and Set_Use, to determine whether
393 -- use clause must be processed. Pack_Name is an entity name that
394 -- references the package in question.
396 procedure Attribute_Renaming (N : Node_Id);
397 -- Analyze renaming of attribute as function. The renaming declaration N
398 -- is rewritten as a function body that returns the attribute reference
399 -- applied to the formals of the function.
401 procedure Check_Frozen_Renaming (N : Node_Id; Subp : Entity_Id);
402 -- A renaming_as_body may occur after the entity of the original decla-
403 -- ration has been frozen. In that case, the body of the new entity must
404 -- be built now, because the usual mechanism of building the renamed
405 -- body at the point of freezing will not work. Subp is the subprogram
406 -- for which N provides the Renaming_As_Body.
408 procedure Check_In_Previous_With_Clause
411 -- N is a use_package clause and Nam the package name, or N is a use_type
412 -- clause and Nam is the prefix of the type name. In either case, verify
413 -- that the package is visible at that point in the context: either it
414 -- appears in a previous with_clause, or because it is a fully qualified
415 -- name and the root ancestor appears in a previous with_clause.
417 procedure Check_Library_Unit_Renaming (N : Node_Id; Old_E : Entity_Id);
418 -- Verify that the entity in a renaming declaration that is a library unit
419 -- is itself a library unit and not a nested unit or subunit. Also check
420 -- that if the renaming is a child unit of a generic parent, then the
421 -- renamed unit must also be a child unit of that parent. Finally, verify
422 -- that a renamed generic unit is not an implicit child declared within
423 -- an instance of the parent.
425 procedure Chain_Use_Clause (N : Node_Id);
426 -- Chain use clause onto list of uses clauses headed by First_Use_Clause in
427 -- the proper scope table entry. This is usually the current scope, but it
428 -- will be an inner scope when installing the use clauses of the private
429 -- declarations of a parent unit prior to compiling the private part of a
430 -- child unit. This chain is traversed when installing/removing use clauses
431 -- when compiling a subunit or instantiating a generic body on the fly,
432 -- when it is necessary to save and restore full environments.
434 function Has_Implicit_Character_Literal (N : Node_Id) return Boolean;
435 -- Find a type derived from Character or Wide_Character in the prefix of N.
436 -- Used to resolved qualified names whose selector is a character literal.
438 function Has_Private_With (E : Entity_Id) return Boolean;
439 -- Ada 2005 (AI-262): Determines if the current compilation unit has a
440 -- private with on E.
442 procedure Find_Expanded_Name (N : Node_Id);
443 -- Selected component is known to be expanded name. Verify legality
444 -- of selector given the scope denoted by prefix.
446 function Find_Renamed_Entity
450 Is_Actual : Boolean := False) return Entity_Id;
451 -- Find the renamed entity that corresponds to the given parameter profile
452 -- in a subprogram renaming declaration. The renamed entity may be an
453 -- operator, a subprogram, an entry, or a protected operation. Is_Actual
454 -- indicates that the renaming is the one generated for an actual subpro-
455 -- gram in an instance, for which special visibility checks apply.
457 function Has_Implicit_Operator (N : Node_Id) return Boolean;
458 -- N is an expanded name whose selector is an operator name (eg P."+").
459 -- declarative part contains an implicit declaration of an operator if it
460 -- has a declaration of a type to which one of the predefined operators
461 -- apply. The existence of this routine is an implementation artifact. A
462 -- more straightforward but more space-consuming choice would be to make
463 -- all inherited operators explicit in the symbol table.
465 procedure Inherit_Renamed_Profile (New_S : Entity_Id; Old_S : Entity_Id);
466 -- A subprogram defined by a renaming declaration inherits the parameter
467 -- profile of the renamed entity. The subtypes given in the subprogram
468 -- specification are discarded and replaced with those of the renamed
469 -- subprogram, which are then used to recheck the default values.
471 function Is_Appropriate_For_Record (T : Entity_Id) return Boolean;
472 -- Prefix is appropriate for record if it is of a record type, or an access
475 function Is_Appropriate_For_Entry_Prefix (T : Entity_Id) return Boolean;
476 -- True if it is of a task type, a protected type, or else an access to one
479 procedure Note_Redundant_Use (Clause : Node_Id);
480 -- Mark the name in a use clause as redundant if the corresponding entity
481 -- is already use-visible. Emit a warning if the use clause comes from
482 -- source and the proper warnings are enabled.
484 procedure Premature_Usage (N : Node_Id);
485 -- Diagnose usage of an entity before it is visible
487 procedure Use_One_Package (P : Entity_Id; N : Node_Id);
488 -- Make visible entities declared in package P potentially use-visible
489 -- in the current context. Also used in the analysis of subunits, when
490 -- re-installing use clauses of parent units. N is the use_clause that
491 -- names P (and possibly other packages).
493 procedure Use_One_Type (Id : Node_Id);
494 -- Id is the subtype mark from a use type clause. This procedure makes
495 -- the primitive operators of the type potentially use-visible.
497 procedure Write_Info;
498 -- Write debugging information on entities declared in current scope
500 procedure Write_Scopes;
501 pragma Warnings (Off, Write_Scopes);
502 -- Debugging information: dump all entities on scope stack
504 --------------------------------
505 -- Analyze_Exception_Renaming --
506 --------------------------------
508 -- The language only allows a single identifier, but the tree holds an
509 -- identifier list. The parser has already issued an error message if
510 -- there is more than one element in the list.
512 procedure Analyze_Exception_Renaming (N : Node_Id) is
513 Id : constant Node_Id := Defining_Identifier (N);
514 Nam : constant Node_Id := Name (N);
520 Set_Ekind (Id, E_Exception);
521 Set_Exception_Code (Id, Uint_0);
522 Set_Etype (Id, Standard_Exception_Type);
523 Set_Is_Pure (Id, Is_Pure (Current_Scope));
525 if not Is_Entity_Name (Nam) or else
526 Ekind (Entity (Nam)) /= E_Exception
528 Error_Msg_N ("invalid exception name in renaming", Nam);
530 if Present (Renamed_Object (Entity (Nam))) then
531 Set_Renamed_Object (Id, Renamed_Object (Entity (Nam)));
533 Set_Renamed_Object (Id, Entity (Nam));
536 end Analyze_Exception_Renaming;
538 ---------------------------
539 -- Analyze_Expanded_Name --
540 ---------------------------
542 procedure Analyze_Expanded_Name (N : Node_Id) is
544 -- If the entity pointer is already set, this is an internal node, or a
545 -- node that is analyzed more than once, after a tree modification. In
546 -- such a case there is no resolution to perform, just set the type. For
547 -- completeness, analyze prefix as well.
549 if Present (Entity (N)) then
550 if Is_Type (Entity (N)) then
551 Set_Etype (N, Entity (N));
553 Set_Etype (N, Etype (Entity (N)));
556 Analyze (Prefix (N));
559 Find_Expanded_Name (N);
561 end Analyze_Expanded_Name;
563 ---------------------------------------
564 -- Analyze_Generic_Function_Renaming --
565 ---------------------------------------
567 procedure Analyze_Generic_Function_Renaming (N : Node_Id) is
569 Analyze_Generic_Renaming (N, E_Generic_Function);
570 end Analyze_Generic_Function_Renaming;
572 --------------------------------------
573 -- Analyze_Generic_Package_Renaming --
574 --------------------------------------
576 procedure Analyze_Generic_Package_Renaming (N : Node_Id) is
578 -- Apply the Text_IO Kludge here, since we may be renaming one of the
579 -- subpackages of Text_IO, then join common routine.
581 Text_IO_Kludge (Name (N));
583 Analyze_Generic_Renaming (N, E_Generic_Package);
584 end Analyze_Generic_Package_Renaming;
586 ----------------------------------------
587 -- Analyze_Generic_Procedure_Renaming --
588 ----------------------------------------
590 procedure Analyze_Generic_Procedure_Renaming (N : Node_Id) is
592 Analyze_Generic_Renaming (N, E_Generic_Procedure);
593 end Analyze_Generic_Procedure_Renaming;
595 ------------------------------
596 -- Analyze_Generic_Renaming --
597 ------------------------------
599 procedure Analyze_Generic_Renaming
603 New_P : constant Entity_Id := Defining_Entity (N);
605 Inst : Boolean := False; -- prevent junk warning
608 if Name (N) = Error then
612 Generate_Definition (New_P);
614 if Current_Scope /= Standard_Standard then
615 Set_Is_Pure (New_P, Is_Pure (Current_Scope));
618 if Nkind (Name (N)) = N_Selected_Component then
619 Check_Generic_Child_Unit (Name (N), Inst);
624 if not Is_Entity_Name (Name (N)) then
625 Error_Msg_N ("expect entity name in renaming declaration", Name (N));
628 Old_P := Entity (Name (N));
632 Set_Ekind (New_P, K);
634 if Etype (Old_P) = Any_Type then
637 elsif Ekind (Old_P) /= K then
638 Error_Msg_N ("invalid generic unit name", Name (N));
641 if Present (Renamed_Object (Old_P)) then
642 Set_Renamed_Object (New_P, Renamed_Object (Old_P));
644 Set_Renamed_Object (New_P, Old_P);
647 Set_Is_Pure (New_P, Is_Pure (Old_P));
648 Set_Is_Preelaborated (New_P, Is_Preelaborated (Old_P));
650 Set_Etype (New_P, Etype (Old_P));
651 Set_Has_Completion (New_P);
653 if In_Open_Scopes (Old_P) then
654 Error_Msg_N ("within its scope, generic denotes its instance", N);
657 Check_Library_Unit_Renaming (N, Old_P);
659 end Analyze_Generic_Renaming;
661 -----------------------------
662 -- Analyze_Object_Renaming --
663 -----------------------------
665 procedure Analyze_Object_Renaming (N : Node_Id) is
666 Id : constant Entity_Id := Defining_Identifier (N);
668 Nam : constant Node_Id := Name (N);
672 function In_Generic_Scope (E : Entity_Id) return Boolean;
673 -- Determine whether entity E is inside a generic cope
675 ----------------------
676 -- In_Generic_Scope --
677 ----------------------
679 function In_Generic_Scope (E : Entity_Id) return Boolean is
684 while Present (S) and then S /= Standard_Standard loop
685 if Is_Generic_Unit (S) then
693 end In_Generic_Scope;
695 -- Start of processing for Analyze_Object_Renaming
702 Set_Is_Pure (Id, Is_Pure (Current_Scope));
705 -- The renaming of a component that depends on a discriminant requires
706 -- an actual subtype, because in subsequent use of the object Gigi will
707 -- be unable to locate the actual bounds. This explicit step is required
708 -- when the renaming is generated in removing side effects of an
709 -- already-analyzed expression.
711 if Nkind (Nam) = N_Selected_Component
712 and then Analyzed (Nam)
715 Dec := Build_Actual_Subtype_Of_Component (Etype (Nam), Nam);
717 if Present (Dec) then
718 Insert_Action (N, Dec);
719 T := Defining_Identifier (Dec);
723 -- Complete analysis of the subtype mark in any case, for ASIS use
725 if Present (Subtype_Mark (N)) then
726 Find_Type (Subtype_Mark (N));
729 elsif Present (Subtype_Mark (N)) then
730 Find_Type (Subtype_Mark (N));
731 T := Entity (Subtype_Mark (N));
734 if Nkind (Nam) = N_Type_Conversion
735 and then not Is_Tagged_Type (T)
738 ("renaming of conversion only allowed for tagged types", Nam);
743 -- Ada 2005 (AI-230/AI-254): Access renaming
745 else pragma Assert (Present (Access_Definition (N)));
746 T := Access_Definition
748 N => Access_Definition (N));
750 Analyze_And_Resolve (Nam, T);
752 -- Ada 2005 (AI-231): "In the case where the type is defined by an
753 -- access_definition, the renamed entity shall be of an access-to-
754 -- constant type if and only if the access_definition defines an
755 -- access-to-constant type" ARM 8.5.1(4)
757 if Constant_Present (Access_Definition (N))
758 and then not Is_Access_Constant (Etype (Nam))
760 Error_Msg_N ("(Ada 2005): the renamed object is not "
761 & "access-to-constant (RM 8.5.1(6))", N);
765 -- Special processing for renaming function return object
767 if Nkind (Nam) = N_Function_Call
768 and then Comes_From_Source (Nam)
772 -- Usage is illegal in Ada 83
776 ("(Ada 83) cannot rename function return object", Nam);
778 -- In Ada 95, warn for odd case of renaming parameterless function
779 -- call if this is not a limited type (where this is useful)
782 if Warn_On_Object_Renames_Function
783 and then No (Parameter_Associations (Nam))
784 and then not Is_Limited_Type (Etype (Nam))
787 ("?renaming function result object is suspicious",
790 ("\?function & will be called only once",
791 Nam, Entity (Name (Nam)));
793 ("\?suggest using an initialized constant object instead",
799 -- An object renaming requires an exact match of the type. Class-wide
800 -- matching is not allowed.
802 if Is_Class_Wide_Type (T)
803 and then Base_Type (Etype (Nam)) /= Base_Type (T)
810 -- (Ada 2005: AI-326): Handle wrong use of incomplete type
812 if Nkind (Nam) = N_Explicit_Dereference
813 and then Ekind (Etype (T2)) = E_Incomplete_Type
815 Error_Msg_N ("invalid use of incomplete type", Id);
821 if Ada_Version >= Ada_05
822 and then Nkind (Nam) = N_Attribute_Reference
823 and then Attribute_Name (Nam) = Name_Priority
827 elsif Ada_Version >= Ada_05
828 and then Nkind (Nam) in N_Has_Entity
831 Error_Node : Node_Id;
834 Subtyp_Decl : Node_Id;
837 if Nkind (Nam) = N_Attribute_Reference then
838 Nam_Ent := Entity (Prefix (Nam));
840 Nam_Ent := Entity (Nam);
843 Nam_Decl := Parent (Nam_Ent);
844 Subtyp_Decl := Parent (Etype (Nam_Ent));
846 if Has_Null_Exclusion (N)
847 and then not Has_Null_Exclusion (Nam_Decl)
849 -- Ada 2005 (AI-423): If the object name denotes a generic
850 -- formal object of a generic unit G, and the object renaming
851 -- declaration occurs within the body of G or within the body
852 -- of a generic unit declared within the declarative region
853 -- of G, then the declaration of the formal object of G must
854 -- have a null exclusion.
856 if Is_Formal_Object (Nam_Ent)
857 and then In_Generic_Scope (Id)
859 if Present (Subtype_Mark (Nam_Decl)) then
860 Error_Node := Subtype_Mark (Nam_Decl);
863 (Ada_Version >= Ada_05
864 and then Present (Access_Definition (Nam_Decl)));
866 Error_Node := Access_Definition (Nam_Decl);
870 ("`NOT NULL` required in formal object declaration",
872 Error_Msg_Sloc := Sloc (N);
874 ("\because of renaming # (RM 8.5.4(4))", Error_Node);
876 -- Ada 2005 (AI-423): Otherwise, the subtype of the object name
877 -- shall exclude null.
879 elsif Nkind (Subtyp_Decl) = N_Subtype_Declaration
880 and then not Has_Null_Exclusion (Subtyp_Decl)
883 ("`NOT NULL` required for subtype & (RM 8.5.1(4.6/2))",
884 Defining_Identifier (Subtyp_Decl));
890 Set_Ekind (Id, E_Variable);
891 Init_Size_Align (Id);
893 if T = Any_Type or else Etype (Nam) = Any_Type then
896 -- Verify that the renamed entity is an object or a function call. It
897 -- may have been rewritten in several ways.
899 elsif Is_Object_Reference (Nam) then
900 if Comes_From_Source (N)
901 and then Is_Dependent_Component_Of_Mutable_Object (Nam)
904 ("illegal renaming of discriminant-dependent component", Nam);
909 -- A static function call may have been folded into a literal
911 elsif Nkind (Original_Node (Nam)) = N_Function_Call
913 -- When expansion is disabled, attribute reference is not
914 -- rewritten as function call. Otherwise it may be rewritten
915 -- as a conversion, so check original node.
917 or else (Nkind (Original_Node (Nam)) = N_Attribute_Reference
918 and then Is_Function_Attribute_Name
919 (Attribute_Name (Original_Node (Nam))))
921 -- Weird but legal, equivalent to renaming a function call.
922 -- Illegal if the literal is the result of constant-folding an
923 -- attribute reference that is not a function.
925 or else (Is_Entity_Name (Nam)
926 and then Ekind (Entity (Nam)) = E_Enumeration_Literal
928 Nkind (Original_Node (Nam)) /= N_Attribute_Reference)
930 or else (Nkind (Nam) = N_Type_Conversion
931 and then Is_Tagged_Type (Entity (Subtype_Mark (Nam))))
935 elsif Nkind (Nam) = N_Type_Conversion then
937 ("renaming of conversion only allowed for tagged types", Nam);
941 elsif Ada_Version >= Ada_05
942 and then Nkind (Nam) = N_Attribute_Reference
943 and then Attribute_Name (Nam) = Name_Priority
948 Error_Msg_N ("expect object name in renaming", Nam);
953 if not Is_Variable (Nam) then
954 Set_Ekind (Id, E_Constant);
955 Set_Never_Set_In_Source (Id, True);
956 Set_Is_True_Constant (Id, True);
959 Set_Renamed_Object (Id, Nam);
960 end Analyze_Object_Renaming;
962 ------------------------------
963 -- Analyze_Package_Renaming --
964 ------------------------------
966 procedure Analyze_Package_Renaming (N : Node_Id) is
967 New_P : constant Entity_Id := Defining_Entity (N);
972 if Name (N) = Error then
976 -- Apply Text_IO kludge here, since we may be renaming one of the
977 -- children of Text_IO
979 Text_IO_Kludge (Name (N));
981 if Current_Scope /= Standard_Standard then
982 Set_Is_Pure (New_P, Is_Pure (Current_Scope));
988 if Is_Entity_Name (Name (N)) then
989 Old_P := Entity (Name (N));
994 if Etype (Old_P) = Any_Type then
996 ("expect package name in renaming", Name (N));
998 elsif Ekind (Old_P) /= E_Package
999 and then not (Ekind (Old_P) = E_Generic_Package
1000 and then In_Open_Scopes (Old_P))
1002 if Ekind (Old_P) = E_Generic_Package then
1004 ("generic package cannot be renamed as a package", Name (N));
1006 Error_Msg_Sloc := Sloc (Old_P);
1008 ("expect package name in renaming, found& declared#",
1012 -- Set basic attributes to minimize cascaded errors
1014 Set_Ekind (New_P, E_Package);
1015 Set_Etype (New_P, Standard_Void_Type);
1018 -- Entities in the old package are accessible through the renaming
1019 -- entity. The simplest implementation is to have both packages share
1022 Set_Ekind (New_P, E_Package);
1023 Set_Etype (New_P, Standard_Void_Type);
1025 if Present (Renamed_Object (Old_P)) then
1026 Set_Renamed_Object (New_P, Renamed_Object (Old_P));
1028 Set_Renamed_Object (New_P, Old_P);
1031 Set_Has_Completion (New_P);
1033 Set_First_Entity (New_P, First_Entity (Old_P));
1034 Set_Last_Entity (New_P, Last_Entity (Old_P));
1035 Set_First_Private_Entity (New_P, First_Private_Entity (Old_P));
1036 Check_Library_Unit_Renaming (N, Old_P);
1037 Generate_Reference (Old_P, Name (N));
1039 -- If this is the renaming declaration of a package instantiation
1040 -- within itself, it is the declaration that ends the list of actuals
1041 -- for the instantiation. At this point, the subtypes that rename
1042 -- the actuals are flagged as generic, to avoid spurious ambiguities
1043 -- if the actuals for two distinct formals happen to coincide. If
1044 -- the actual is a private type, the subtype has a private completion
1045 -- that is flagged in the same fashion.
1047 -- Resolution is identical to what is was in the original generic.
1048 -- On exit from the generic instance, these are turned into regular
1049 -- subtypes again, so they are compatible with types in their class.
1051 if not Is_Generic_Instance (Old_P) then
1054 Spec := Specification (Unit_Declaration_Node (Old_P));
1057 if Nkind (Spec) = N_Package_Specification
1058 and then Present (Generic_Parent (Spec))
1059 and then Old_P = Current_Scope
1060 and then Chars (New_P) = Chars (Generic_Parent (Spec))
1066 E := First_Entity (Old_P);
1071 and then Nkind (Parent (E)) = N_Subtype_Declaration
1073 Set_Is_Generic_Actual_Type (E);
1075 if Is_Private_Type (E)
1076 and then Present (Full_View (E))
1078 Set_Is_Generic_Actual_Type (Full_View (E));
1088 end Analyze_Package_Renaming;
1090 -------------------------------
1091 -- Analyze_Renamed_Character --
1092 -------------------------------
1094 procedure Analyze_Renamed_Character
1099 C : constant Node_Id := Name (N);
1102 if Ekind (New_S) = E_Function then
1103 Resolve (C, Etype (New_S));
1106 Check_Frozen_Renaming (N, New_S);
1110 Error_Msg_N ("character literal can only be renamed as function", N);
1112 end Analyze_Renamed_Character;
1114 ---------------------------------
1115 -- Analyze_Renamed_Dereference --
1116 ---------------------------------
1118 procedure Analyze_Renamed_Dereference
1123 Nam : constant Node_Id := Name (N);
1124 P : constant Node_Id := Prefix (Nam);
1130 if not Is_Overloaded (P) then
1131 if Ekind (Etype (Nam)) /= E_Subprogram_Type
1132 or else not Type_Conformant (Etype (Nam), New_S) then
1133 Error_Msg_N ("designated type does not match specification", P);
1142 Get_First_Interp (Nam, Ind, It);
1144 while Present (It.Nam) loop
1146 if Ekind (It.Nam) = E_Subprogram_Type
1147 and then Type_Conformant (It.Nam, New_S) then
1149 if Typ /= Any_Id then
1150 Error_Msg_N ("ambiguous renaming", P);
1157 Get_Next_Interp (Ind, It);
1160 if Typ = Any_Type then
1161 Error_Msg_N ("designated type does not match specification", P);
1166 Check_Frozen_Renaming (N, New_S);
1170 end Analyze_Renamed_Dereference;
1172 ---------------------------
1173 -- Analyze_Renamed_Entry --
1174 ---------------------------
1176 procedure Analyze_Renamed_Entry
1181 Nam : constant Node_Id := Name (N);
1182 Sel : constant Node_Id := Selector_Name (Nam);
1186 if Entity (Sel) = Any_Id then
1188 -- Selector is undefined on prefix. Error emitted already
1190 Set_Has_Completion (New_S);
1194 -- Otherwise find renamed entity and build body of New_S as a call to it
1196 Old_S := Find_Renamed_Entity (N, Selector_Name (Nam), New_S);
1198 if Old_S = Any_Id then
1199 Error_Msg_N (" no subprogram or entry matches specification", N);
1202 Check_Subtype_Conformant (New_S, Old_S, N);
1203 Generate_Reference (New_S, Defining_Entity (N), 'b');
1204 Style.Check_Identifier (Defining_Entity (N), New_S);
1207 -- Only mode conformance required for a renaming_as_declaration
1209 Check_Mode_Conformant (New_S, Old_S, N);
1212 Inherit_Renamed_Profile (New_S, Old_S);
1215 Set_Convention (New_S, Convention (Old_S));
1216 Set_Has_Completion (New_S, Inside_A_Generic);
1219 Check_Frozen_Renaming (N, New_S);
1221 end Analyze_Renamed_Entry;
1223 -----------------------------------
1224 -- Analyze_Renamed_Family_Member --
1225 -----------------------------------
1227 procedure Analyze_Renamed_Family_Member
1232 Nam : constant Node_Id := Name (N);
1233 P : constant Node_Id := Prefix (Nam);
1237 if (Is_Entity_Name (P) and then Ekind (Entity (P)) = E_Entry_Family)
1238 or else (Nkind (P) = N_Selected_Component
1240 Ekind (Entity (Selector_Name (P))) = E_Entry_Family)
1242 if Is_Entity_Name (P) then
1243 Old_S := Entity (P);
1245 Old_S := Entity (Selector_Name (P));
1248 if not Entity_Matches_Spec (Old_S, New_S) then
1249 Error_Msg_N ("entry family does not match specification", N);
1252 Check_Subtype_Conformant (New_S, Old_S, N);
1253 Generate_Reference (New_S, Defining_Entity (N), 'b');
1254 Style.Check_Identifier (Defining_Entity (N), New_S);
1258 Error_Msg_N ("no entry family matches specification", N);
1261 Set_Has_Completion (New_S, Inside_A_Generic);
1264 Check_Frozen_Renaming (N, New_S);
1266 end Analyze_Renamed_Family_Member;
1268 ---------------------------------
1269 -- Analyze_Subprogram_Renaming --
1270 ---------------------------------
1272 procedure Analyze_Subprogram_Renaming (N : Node_Id) is
1273 Formal_Spec : constant Node_Id := Corresponding_Formal_Spec (N);
1274 Is_Actual : constant Boolean := Present (Formal_Spec);
1275 Inst_Node : Node_Id := Empty;
1276 Nam : constant Node_Id := Name (N);
1278 Old_S : Entity_Id := Empty;
1279 Rename_Spec : Entity_Id;
1280 Save_AV : constant Ada_Version_Type := Ada_Version;
1281 Save_AV_Exp : constant Ada_Version_Type := Ada_Version_Explicit;
1282 Spec : constant Node_Id := Specification (N);
1284 procedure Check_Null_Exclusion
1287 -- Ada 2005 (AI-423): Given renaming Ren of subprogram Sub, check the
1288 -- following AI rules:
1290 -- If Ren is a renaming of a formal subprogram and one of its
1291 -- parameters has a null exclusion, then the corresponding formal
1292 -- in Sub must also have one. Otherwise the subtype of the Sub's
1293 -- formal parameter must exclude null.
1295 -- If Ren is a renaming of a formal function and its retrun
1296 -- profile has a null exclusion, then Sub's return profile must
1297 -- have one. Otherwise the subtype of Sub's return profile must
1300 function Original_Subprogram (Subp : Entity_Id) return Entity_Id;
1301 -- Find renamed entity when the declaration is a renaming_as_body and
1302 -- the renamed entity may itself be a renaming_as_body. Used to enforce
1303 -- rule that a renaming_as_body is illegal if the declaration occurs
1304 -- before the subprogram it completes is frozen, and renaming indirectly
1305 -- renames the subprogram itself.(Defect Report 8652/0027).
1307 --------------------------
1308 -- Check_Null_Exclusion --
1309 --------------------------
1311 procedure Check_Null_Exclusion
1315 Ren_Formal : Entity_Id;
1316 Sub_Formal : Entity_Id;
1321 Ren_Formal := First_Formal (Ren);
1322 Sub_Formal := First_Formal (Sub);
1323 while Present (Ren_Formal)
1324 and then Present (Sub_Formal)
1326 if Has_Null_Exclusion (Parent (Ren_Formal))
1328 not (Has_Null_Exclusion (Parent (Sub_Formal))
1329 or else Can_Never_Be_Null (Etype (Sub_Formal)))
1332 ("`NOT NULL` required for parameter &",
1333 Parent (Sub_Formal), Sub_Formal);
1336 Next_Formal (Ren_Formal);
1337 Next_Formal (Sub_Formal);
1340 -- Return profile check
1342 if Nkind (Parent (Ren)) = N_Function_Specification
1343 and then Nkind (Parent (Sub)) = N_Function_Specification
1344 and then Has_Null_Exclusion (Parent (Ren))
1346 not (Has_Null_Exclusion (Parent (Sub))
1347 or else Can_Never_Be_Null (Etype (Sub)))
1350 ("return must specify `NOT NULL`",
1351 Result_Definition (Parent (Sub)));
1353 end Check_Null_Exclusion;
1355 -------------------------
1356 -- Original_Subprogram --
1357 -------------------------
1359 function Original_Subprogram (Subp : Entity_Id) return Entity_Id is
1360 Orig_Decl : Node_Id;
1361 Orig_Subp : Entity_Id;
1364 -- First case: renamed entity is itself a renaming
1366 if Present (Alias (Subp)) then
1367 return Alias (Subp);
1370 Nkind (Unit_Declaration_Node (Subp)) = N_Subprogram_Declaration
1372 (Corresponding_Body (Unit_Declaration_Node (Subp)))
1374 -- Check if renamed entity is a renaming_as_body
1377 Unit_Declaration_Node
1378 (Corresponding_Body (Unit_Declaration_Node (Subp)));
1380 if Nkind (Orig_Decl) = N_Subprogram_Renaming_Declaration then
1381 Orig_Subp := Entity (Name (Orig_Decl));
1383 if Orig_Subp = Rename_Spec then
1385 -- Circularity detected
1390 return (Original_Subprogram (Orig_Subp));
1398 end Original_Subprogram;
1400 -- Start of processing for Analyze_Subprogram_Renaming
1403 -- We must test for the attribute renaming case before the Analyze
1404 -- call because otherwise Sem_Attr will complain that the attribute
1405 -- is missing an argument when it is analyzed.
1407 if Nkind (Nam) = N_Attribute_Reference then
1409 -- In the case of an abstract formal subprogram association, rewrite
1410 -- an actual given by a stream attribute as the name of the
1411 -- corresponding stream primitive of the type.
1413 -- In a generic context the stream operations are not generated, and
1414 -- this must be treated as a normal attribute reference, to be
1415 -- expanded in subsequent instantiations.
1417 if Is_Actual and then Is_Abstract_Subprogram (Formal_Spec)
1418 and then Expander_Active
1421 Stream_Prim : Entity_Id;
1422 Prefix_Type : constant Entity_Id := Entity (Prefix (Nam));
1425 -- The class-wide forms of the stream attributes are not
1426 -- primitive dispatching operations (even though they
1427 -- internally dispatch to a stream attribute).
1429 if Is_Class_Wide_Type (Prefix_Type) then
1431 ("attribute must be a primitive dispatching operation",
1436 -- Retrieve the primitive subprogram associated with the
1437 -- attribute. This can only be a stream attribute, since those
1438 -- are the only ones that are dispatching (and the actual for
1439 -- an abstract formal subprogram must be dispatching
1442 case Attribute_Name (Nam) is
1445 Find_Prim_Op (Prefix_Type, TSS_Stream_Input);
1448 Find_Prim_Op (Prefix_Type, TSS_Stream_Output);
1451 Find_Prim_Op (Prefix_Type, TSS_Stream_Read);
1454 Find_Prim_Op (Prefix_Type, TSS_Stream_Write);
1457 ("attribute must be a primitive dispatching operation",
1462 -- Rewrite the attribute into the name of its corresponding
1463 -- primitive dispatching subprogram. We can then proceed with
1464 -- the usual processing for subprogram renamings.
1467 Prim_Name : constant Node_Id :=
1468 Make_Identifier (Sloc (Nam),
1469 Chars => Chars (Stream_Prim));
1471 Set_Entity (Prim_Name, Stream_Prim);
1472 Rewrite (Nam, Prim_Name);
1477 -- Normal processing for a renaming of an attribute
1480 Attribute_Renaming (N);
1485 -- Check whether this declaration corresponds to the instantiation
1486 -- of a formal subprogram.
1488 -- If this is an instantiation, the corresponding actual is frozen and
1489 -- error messages can be made more precise. If this is a default
1490 -- subprogram, the entity is already established in the generic, and is
1491 -- not retrieved by visibility. If it is a default with a box, the
1492 -- candidate interpretations, if any, have been collected when building
1493 -- the renaming declaration. If overloaded, the proper interpretation is
1494 -- determined in Find_Renamed_Entity. If the entity is an operator,
1495 -- Find_Renamed_Entity applies additional visibility checks.
1498 Inst_Node := Unit_Declaration_Node (Formal_Spec);
1500 if Is_Entity_Name (Nam)
1501 and then Present (Entity (Nam))
1502 and then not Comes_From_Source (Nam)
1503 and then not Is_Overloaded (Nam)
1505 Old_S := Entity (Nam);
1506 New_S := Analyze_Subprogram_Specification (Spec);
1510 if Ekind (Entity (Nam)) = E_Operator then
1514 if Box_Present (Inst_Node) then
1515 Old_S := Find_Renamed_Entity (N, Name (N), New_S, Is_Actual);
1517 -- If there is an immediately visible homonym of the operator
1518 -- and the declaration has a default, this is worth a warning
1519 -- because the user probably did not intend to get the pre-
1520 -- defined operator, visible in the generic declaration. To
1521 -- find if there is an intended candidate, analyze the renaming
1522 -- again in the current context.
1524 elsif Scope (Old_S) = Standard_Standard
1525 and then Present (Default_Name (Inst_Node))
1528 Decl : constant Node_Id := New_Copy_Tree (N);
1532 Set_Entity (Name (Decl), Empty);
1533 Analyze (Name (Decl));
1535 Find_Renamed_Entity (Decl, Name (Decl), New_S, True);
1538 and then In_Open_Scopes (Scope (Hidden))
1539 and then Is_Immediately_Visible (Hidden)
1540 and then Comes_From_Source (Hidden)
1541 and then Hidden /= Old_S
1543 Error_Msg_Sloc := Sloc (Hidden);
1544 Error_Msg_N ("?default subprogram is resolved " &
1545 "in the generic declaration " &
1546 "(RM 12.6(17))", N);
1547 Error_Msg_NE ("\?and will not use & #", N, Hidden);
1555 New_S := Analyze_Subprogram_Specification (Spec);
1559 -- Renamed entity must be analyzed first, to avoid being hidden by
1560 -- new name (which might be the same in a generic instance).
1564 -- The renaming defines a new overloaded entity, which is analyzed
1565 -- like a subprogram declaration.
1567 New_S := Analyze_Subprogram_Specification (Spec);
1570 if Current_Scope /= Standard_Standard then
1571 Set_Is_Pure (New_S, Is_Pure (Current_Scope));
1574 Rename_Spec := Find_Corresponding_Spec (N);
1576 if Present (Rename_Spec) then
1578 -- Renaming_As_Body. Renaming declaration is the completion of
1579 -- the declaration of Rename_Spec. We will build an actual body
1580 -- for it at the freezing point.
1582 Set_Corresponding_Spec (N, Rename_Spec);
1584 if Nkind (Unit_Declaration_Node (Rename_Spec)) =
1585 N_Abstract_Subprogram_Declaration
1587 -- Input and Output stream functions are abstract if the object
1588 -- type is abstract. However, these functions may receive explicit
1589 -- declarations in representation clauses, making the attribute
1590 -- subprograms usable as defaults in subsequent type extensions.
1591 -- In this case we rewrite the declaration to make the subprogram
1592 -- non-abstract. We remove the previous declaration, and insert
1593 -- the new one at the point of the renaming, to prevent premature
1594 -- access to unfrozen types. The new declaration reuses the
1595 -- specification of the previous one, and must not be analyzed.
1597 pragma Assert (Is_TSS (Rename_Spec, TSS_Stream_Output)
1598 or else Is_TSS (Rename_Spec, TSS_Stream_Input));
1601 Old_Decl : constant Node_Id :=
1602 Unit_Declaration_Node (Rename_Spec);
1603 New_Decl : constant Node_Id :=
1604 Make_Subprogram_Declaration (Sloc (N),
1606 Relocate_Node (Specification (Old_Decl)));
1609 Insert_After (N, New_Decl);
1610 Set_Is_Abstract_Subprogram (Rename_Spec, False);
1611 Set_Analyzed (New_Decl);
1615 Set_Corresponding_Body (Unit_Declaration_Node (Rename_Spec), New_S);
1617 if Ada_Version = Ada_83 and then Comes_From_Source (N) then
1618 Error_Msg_N ("(Ada 83) renaming cannot serve as a body", N);
1621 Set_Convention (New_S, Convention (Rename_Spec));
1622 Check_Fully_Conformant (New_S, Rename_Spec);
1623 Set_Public_Status (New_S);
1625 -- Indicate that the entity in the declaration functions like the
1626 -- corresponding body, and is not a new entity. The body will be
1627 -- constructed later at the freeze point, so indicate that the
1628 -- completion has not been seen yet.
1630 Set_Ekind (New_S, E_Subprogram_Body);
1631 New_S := Rename_Spec;
1632 Set_Has_Completion (Rename_Spec, False);
1634 -- Ada 2005: check overriding indicator
1636 if Must_Override (Specification (N))
1637 and then not Is_Overriding_Operation (Rename_Spec)
1639 Error_Msg_NE ("subprogram& is not overriding", N, Rename_Spec);
1641 elsif Must_Not_Override (Specification (N))
1642 and then Is_Overriding_Operation (Rename_Spec)
1645 ("subprogram& overrides inherited operation", N, Rename_Spec);
1649 Generate_Definition (New_S);
1650 New_Overloaded_Entity (New_S);
1652 if Is_Entity_Name (Nam)
1653 and then Is_Intrinsic_Subprogram (Entity (Nam))
1657 Check_Delayed_Subprogram (New_S);
1661 -- There is no need for elaboration checks on the new entity, which may
1662 -- be called before the next freezing point where the body will appear.
1663 -- Elaboration checks refer to the real entity, not the one created by
1664 -- the renaming declaration.
1666 Set_Kill_Elaboration_Checks (New_S, True);
1668 if Etype (Nam) = Any_Type then
1669 Set_Has_Completion (New_S);
1672 elsif Nkind (Nam) = N_Selected_Component then
1674 -- Renamed entity is an entry or protected subprogram. For those
1675 -- cases an explicit body is built (at the point of freezing of this
1676 -- entity) that contains a call to the renamed entity.
1678 Analyze_Renamed_Entry (N, New_S, Present (Rename_Spec));
1681 elsif Nkind (Nam) = N_Explicit_Dereference then
1683 -- Renamed entity is designated by access_to_subprogram expression.
1684 -- Must build body to encapsulate call, as in the entry case.
1686 Analyze_Renamed_Dereference (N, New_S, Present (Rename_Spec));
1689 elsif Nkind (Nam) = N_Indexed_Component then
1690 Analyze_Renamed_Family_Member (N, New_S, Present (Rename_Spec));
1693 elsif Nkind (Nam) = N_Character_Literal then
1694 Analyze_Renamed_Character (N, New_S, Present (Rename_Spec));
1697 elsif (not Is_Entity_Name (Nam)
1698 and then Nkind (Nam) /= N_Operator_Symbol)
1699 or else not Is_Overloadable (Entity (Nam))
1701 Error_Msg_N ("expect valid subprogram name in renaming", N);
1705 -- Find the renamed entity that matches the given specification. Disable
1706 -- Ada_83 because there is no requirement of full conformance between
1707 -- renamed entity and new entity, even though the same circuit is used.
1709 -- This is a bit of a kludge, which introduces a really irregular use of
1710 -- Ada_Version[_Explicit]. Would be nice to find cleaner way to do this
1713 Ada_Version := Ada_Version_Type'Max (Ada_Version, Ada_95);
1714 Ada_Version_Explicit := Ada_Version;
1717 Old_S := Find_Renamed_Entity (N, Name (N), New_S, Is_Actual);
1719 -- When the renamed subprogram is overloaded and used as an actual
1720 -- of a generic, its entity is set to the first available homonym.
1721 -- We must first disambiguate the name, then set the proper entity.
1724 and then Is_Overloaded (Nam)
1726 Set_Entity (Nam, Old_S);
1730 -- Most common case: subprogram renames subprogram. No body is generated
1731 -- in this case, so we must indicate the declaration is complete as is.
1733 if No (Rename_Spec) then
1734 Set_Has_Completion (New_S);
1735 Set_Is_Pure (New_S, Is_Pure (Entity (Nam)));
1736 Set_Is_Preelaborated (New_S, Is_Preelaborated (Entity (Nam)));
1738 -- Ada 2005 (AI-423): Check the consistency of null exclusions
1739 -- between a subprogram and its correct renaming.
1741 -- Note: the Any_Id check is a guard that prevents compiler crashes
1742 -- when performing a null exclusion check between a renaming and a
1743 -- renamed subprogram that has been found to be illegal.
1745 if Ada_Version >= Ada_05
1746 and then Entity (Nam) /= Any_Id
1748 Check_Null_Exclusion
1750 Sub => Entity (Nam));
1754 if Old_S /= Any_Id then
1756 and then From_Default (N)
1758 -- This is an implicit reference to the default actual
1760 Generate_Reference (Old_S, Nam, Typ => 'i', Force => True);
1762 Generate_Reference (Old_S, Nam);
1765 -- For a renaming-as-body, require subtype conformance, but if the
1766 -- declaration being completed has not been frozen, then inherit the
1767 -- convention of the renamed subprogram prior to checking conformance
1768 -- (unless the renaming has an explicit convention established; the
1769 -- rule stated in the RM doesn't seem to address this ???).
1771 if Present (Rename_Spec) then
1772 Generate_Reference (Rename_Spec, Defining_Entity (Spec), 'b');
1773 Style.Check_Identifier (Defining_Entity (Spec), Rename_Spec);
1775 if not Is_Frozen (Rename_Spec) then
1776 if not Has_Convention_Pragma (Rename_Spec) then
1777 Set_Convention (New_S, Convention (Old_S));
1780 if Ekind (Old_S) /= E_Operator then
1781 Check_Mode_Conformant (New_S, Old_S, Spec);
1784 if Original_Subprogram (Old_S) = Rename_Spec then
1785 Error_Msg_N ("unfrozen subprogram cannot rename itself ", N);
1788 Check_Subtype_Conformant (New_S, Old_S, Spec);
1791 Check_Frozen_Renaming (N, Rename_Spec);
1793 -- Check explicitly that renamed entity is not intrinsic, because
1794 -- in in a generic the renamed body is not built. In this case,
1795 -- the renaming_as_body is a completion.
1797 if Inside_A_Generic then
1798 if Is_Frozen (Rename_Spec)
1799 and then Is_Intrinsic_Subprogram (Old_S)
1802 ("subprogram in renaming_as_body cannot be intrinsic",
1806 Set_Has_Completion (Rename_Spec);
1809 elsif Ekind (Old_S) /= E_Operator then
1810 Check_Mode_Conformant (New_S, Old_S);
1813 and then Error_Posted (New_S)
1815 Error_Msg_NE ("invalid actual subprogram: & #!", N, Old_S);
1819 if No (Rename_Spec) then
1821 -- The parameter profile of the new entity is that of the renamed
1822 -- entity: the subtypes given in the specification are irrelevant.
1824 Inherit_Renamed_Profile (New_S, Old_S);
1826 -- A call to the subprogram is transformed into a call to the
1827 -- renamed entity. This is transitive if the renamed entity is
1828 -- itself a renaming.
1830 if Present (Alias (Old_S)) then
1831 Set_Alias (New_S, Alias (Old_S));
1833 Set_Alias (New_S, Old_S);
1836 -- Note that we do not set Is_Intrinsic_Subprogram if we have a
1837 -- renaming as body, since the entity in this case is not an
1838 -- intrinsic (it calls an intrinsic, but we have a real body for
1839 -- this call, and it is in this body that the required intrinsic
1840 -- processing will take place).
1842 -- Also, if this is a renaming of inequality, the renamed operator
1843 -- is intrinsic, but what matters is the corresponding equality
1844 -- operator, which may be user-defined.
1846 Set_Is_Intrinsic_Subprogram
1848 Is_Intrinsic_Subprogram (Old_S)
1850 (Chars (Old_S) /= Name_Op_Ne
1851 or else Ekind (Old_S) = E_Operator
1853 Is_Intrinsic_Subprogram
1854 (Corresponding_Equality (Old_S))));
1856 if Ekind (Alias (New_S)) = E_Operator then
1857 Set_Has_Delayed_Freeze (New_S, False);
1860 -- If the renaming corresponds to an association for an abstract
1861 -- formal subprogram, then various attributes must be set to
1862 -- indicate that the renaming is an abstract dispatching operation
1863 -- with a controlling type.
1865 if Is_Actual and then Is_Abstract_Subprogram (Formal_Spec) then
1867 -- Mark the renaming as abstract here, so Find_Dispatching_Type
1868 -- see it as corresponding to a generic association for a
1869 -- formal abstract subprogram
1871 Set_Is_Abstract_Subprogram (New_S);
1874 New_S_Ctrl_Type : constant Entity_Id :=
1875 Find_Dispatching_Type (New_S);
1876 Old_S_Ctrl_Type : constant Entity_Id :=
1877 Find_Dispatching_Type (Old_S);
1880 if Old_S_Ctrl_Type /= New_S_Ctrl_Type then
1882 ("actual must be dispatching subprogram for type&",
1883 Nam, New_S_Ctrl_Type);
1886 Set_Is_Dispatching_Operation (New_S);
1887 Check_Controlling_Formals (New_S_Ctrl_Type, New_S);
1889 -- If the actual in the formal subprogram is itself a
1890 -- formal abstract subprogram association, there's no
1891 -- dispatch table component or position to inherit.
1893 if Present (DTC_Entity (Old_S)) then
1894 Set_DTC_Entity (New_S, DTC_Entity (Old_S));
1895 Set_DT_Position (New_S, DT_Position (Old_S));
1903 and then (Old_S = New_S
1904 or else (Nkind (Nam) /= N_Expanded_Name
1905 and then Chars (Old_S) = Chars (New_S)))
1907 Error_Msg_N ("subprogram cannot rename itself", N);
1910 Set_Convention (New_S, Convention (Old_S));
1912 if Is_Abstract_Subprogram (Old_S) then
1913 if Present (Rename_Spec) then
1915 ("a renaming-as-body cannot rename an abstract subprogram",
1917 Set_Has_Completion (Rename_Spec);
1919 Set_Is_Abstract_Subprogram (New_S);
1923 Check_Library_Unit_Renaming (N, Old_S);
1925 -- Pathological case: procedure renames entry in the scope of its
1926 -- task. Entry is given by simple name, but body must be built for
1927 -- procedure. Of course if called it will deadlock.
1929 if Ekind (Old_S) = E_Entry then
1930 Set_Has_Completion (New_S, False);
1931 Set_Alias (New_S, Empty);
1935 Freeze_Before (N, Old_S);
1936 Set_Has_Delayed_Freeze (New_S, False);
1937 Freeze_Before (N, New_S);
1939 -- An abstract subprogram is only allowed as an actual in the case
1940 -- where the formal subprogram is also abstract.
1942 if (Ekind (Old_S) = E_Procedure or else Ekind (Old_S) = E_Function)
1943 and then Is_Abstract_Subprogram (Old_S)
1944 and then not Is_Abstract_Subprogram (Formal_Spec)
1947 ("abstract subprogram not allowed as generic actual", Nam);
1952 -- A common error is to assume that implicit operators for types are
1953 -- defined in Standard, or in the scope of a subtype. In those cases
1954 -- where the renamed entity is given with an expanded name, it is
1955 -- worth mentioning that operators for the type are not declared in
1956 -- the scope given by the prefix.
1958 if Nkind (Nam) = N_Expanded_Name
1959 and then Nkind (Selector_Name (Nam)) = N_Operator_Symbol
1960 and then Scope (Entity (Nam)) = Standard_Standard
1963 T : constant Entity_Id :=
1964 Base_Type (Etype (First_Formal (New_S)));
1966 Error_Msg_Node_2 := Prefix (Nam);
1968 ("operator for type& is not declared in&", Prefix (Nam), T);
1973 ("no visible subprogram matches the specification for&",
1977 if Present (Candidate_Renaming) then
1983 F1 := First_Formal (Candidate_Renaming);
1984 F2 := First_Formal (New_S);
1986 while Present (F1) and then Present (F2) loop
1991 if Present (F1) and then Present (Default_Value (F1)) then
1992 if Present (Next_Formal (F1)) then
1994 ("\missing specification for &" &
1995 " and other formals with defaults", Spec, F1);
1998 ("\missing specification for &", Spec, F1);
2005 -- Ada 2005 AI 404: if the new subprogram is dispatching, verify that
2006 -- controlling access parameters are known non-null for the renamed
2007 -- subprogram. Test also applies to a subprogram instantiation that
2008 -- is dispatching. Test is skipped if some previous error was detected
2009 -- that set Old_S to Any_Id.
2011 if Ada_Version >= Ada_05
2012 and then Old_S /= Any_Id
2013 and then not Is_Dispatching_Operation (Old_S)
2014 and then Is_Dispatching_Operation (New_S)
2021 Old_F := First_Formal (Old_S);
2022 New_F := First_Formal (New_S);
2023 while Present (Old_F) loop
2024 if Ekind (Etype (Old_F)) = E_Anonymous_Access_Type
2025 and then Is_Controlling_Formal (New_F)
2026 and then not Can_Never_Be_Null (Old_F)
2028 Error_Msg_N ("access parameter is controlling,", New_F);
2030 ("\corresponding parameter of& "
2031 & "must be explicitly null excluding", New_F, Old_S);
2034 Next_Formal (Old_F);
2035 Next_Formal (New_F);
2040 -- A useful warning, suggested by Ada Bug Finder (Ada-Europe 2005)
2042 if Comes_From_Source (N)
2043 and then Present (Old_S)
2044 and then Nkind (Old_S) = N_Defining_Operator_Symbol
2045 and then Nkind (New_S) = N_Defining_Operator_Symbol
2046 and then Chars (Old_S) /= Chars (New_S)
2049 ("?& is being renamed as a different operator",
2053 -- Another warning or some utility: if the new subprogram as the same
2054 -- name as the old one, the old one is not hidden by an outer homograph,
2055 -- the new one is not a public symbol, and the old one is otherwise
2056 -- directly visible, the renaming is superfluous.
2058 if Chars (Old_S) = Chars (New_S)
2059 and then Comes_From_Source (N)
2060 and then Scope (Old_S) /= Standard_Standard
2061 and then Warn_On_Redundant_Constructs
2063 (Is_Immediately_Visible (Old_S)
2064 or else Is_Potentially_Use_Visible (Old_S))
2065 and then Is_Overloadable (Current_Scope)
2066 and then Chars (Current_Scope) /= Chars (Old_S)
2069 ("?redundant renaming, entity is directly visible", Name (N));
2072 Ada_Version := Save_AV;
2073 Ada_Version_Explicit := Save_AV_Exp;
2074 end Analyze_Subprogram_Renaming;
2076 -------------------------
2077 -- Analyze_Use_Package --
2078 -------------------------
2080 -- Resolve the package names in the use clause, and make all the visible
2081 -- entities defined in the package potentially use-visible. If the package
2082 -- is already in use from a previous use clause, its visible entities are
2083 -- already use-visible. In that case, mark the occurrence as a redundant
2084 -- use. If the package is an open scope, i.e. if the use clause occurs
2085 -- within the package itself, ignore it.
2087 procedure Analyze_Use_Package (N : Node_Id) is
2088 Pack_Name : Node_Id;
2091 -- Start of processing for Analyze_Use_Package
2094 Set_Hidden_By_Use_Clause (N, No_Elist);
2096 -- Use clause is not allowed in a spec of a predefined package
2097 -- declaration except that packages whose file name starts a-n are OK
2098 -- (these are children of Ada.Numerics, and such packages are never
2099 -- loaded by Rtsfind).
2101 if Is_Predefined_File_Name (Unit_File_Name (Current_Sem_Unit))
2102 and then Name_Buffer (1 .. 3) /= "a-n"
2104 Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Declaration
2106 Error_Msg_N ("use clause not allowed in predefined spec", N);
2109 -- Chain clause to list of use clauses in current scope
2111 if Nkind (Parent (N)) /= N_Compilation_Unit then
2112 Chain_Use_Clause (N);
2115 -- Loop through package names to identify referenced packages
2117 Pack_Name := First (Names (N));
2118 while Present (Pack_Name) loop
2119 Analyze (Pack_Name);
2121 if Nkind (Parent (N)) = N_Compilation_Unit
2122 and then Nkind (Pack_Name) = N_Expanded_Name
2128 Pref := Prefix (Pack_Name);
2129 while Nkind (Pref) = N_Expanded_Name loop
2130 Pref := Prefix (Pref);
2133 if Entity (Pref) = Standard_Standard then
2135 ("predefined package Standard cannot appear"
2136 & " in a context clause", Pref);
2144 -- Loop through package names to mark all entities as potentially
2147 Pack_Name := First (Names (N));
2148 while Present (Pack_Name) loop
2149 if Is_Entity_Name (Pack_Name) then
2150 Pack := Entity (Pack_Name);
2152 if Ekind (Pack) /= E_Package
2153 and then Etype (Pack) /= Any_Type
2155 if Ekind (Pack) = E_Generic_Package then
2157 ("a generic package is not allowed in a use clause",
2160 Error_Msg_N ("& is not a usable package", Pack_Name);
2164 if Nkind (Parent (N)) = N_Compilation_Unit then
2165 Check_In_Previous_With_Clause (N, Pack_Name);
2168 if Applicable_Use (Pack_Name) then
2169 Use_One_Package (Pack, N);
2176 end Analyze_Use_Package;
2178 ----------------------
2179 -- Analyze_Use_Type --
2180 ----------------------
2182 procedure Analyze_Use_Type (N : Node_Id) is
2187 Set_Hidden_By_Use_Clause (N, No_Elist);
2189 -- Chain clause to list of use clauses in current scope
2191 if Nkind (Parent (N)) /= N_Compilation_Unit then
2192 Chain_Use_Clause (N);
2195 Id := First (Subtype_Marks (N));
2196 while Present (Id) loop
2200 if E /= Any_Type then
2203 if Nkind (Parent (N)) = N_Compilation_Unit then
2204 if Nkind (Id) = N_Identifier then
2205 Error_Msg_N ("type is not directly visible", Id);
2207 elsif Is_Child_Unit (Scope (E))
2208 and then Scope (E) /= System_Aux_Id
2210 Check_In_Previous_With_Clause (N, Prefix (Id));
2217 end Analyze_Use_Type;
2219 --------------------
2220 -- Applicable_Use --
2221 --------------------
2223 function Applicable_Use (Pack_Name : Node_Id) return Boolean is
2224 Pack : constant Entity_Id := Entity (Pack_Name);
2227 if In_Open_Scopes (Pack) then
2228 if Warn_On_Redundant_Constructs
2229 and then Pack = Current_Scope
2232 ("& is already use-visible within itself?", Pack_Name, Pack);
2237 elsif In_Use (Pack) then
2238 Note_Redundant_Use (Pack_Name);
2241 elsif Present (Renamed_Object (Pack))
2242 and then In_Use (Renamed_Object (Pack))
2244 Note_Redundant_Use (Pack_Name);
2252 ------------------------
2253 -- Attribute_Renaming --
2254 ------------------------
2256 procedure Attribute_Renaming (N : Node_Id) is
2257 Loc : constant Source_Ptr := Sloc (N);
2258 Nam : constant Node_Id := Name (N);
2259 Spec : constant Node_Id := Specification (N);
2260 New_S : constant Entity_Id := Defining_Unit_Name (Spec);
2261 Aname : constant Name_Id := Attribute_Name (Nam);
2263 Form_Num : Nat := 0;
2264 Expr_List : List_Id := No_List;
2266 Attr_Node : Node_Id;
2267 Body_Node : Node_Id;
2268 Param_Spec : Node_Id;
2271 Generate_Definition (New_S);
2273 -- This procedure is called in the context of subprogram renaming,
2274 -- and thus the attribute must be one that is a subprogram. All of
2275 -- those have at least one formal parameter, with the singular
2276 -- exception of AST_Entry (which is a real oddity, it is odd that
2277 -- this can be renamed at all!)
2279 if not Is_Non_Empty_List (Parameter_Specifications (Spec)) then
2280 if Aname /= Name_AST_Entry then
2282 ("subprogram renaming an attribute must have formals", N);
2287 Param_Spec := First (Parameter_Specifications (Spec));
2288 while Present (Param_Spec) loop
2289 Form_Num := Form_Num + 1;
2291 if Nkind (Parameter_Type (Param_Spec)) /= N_Access_Definition then
2292 Find_Type (Parameter_Type (Param_Spec));
2294 -- The profile of the new entity denotes the base type (s) of
2295 -- the types given in the specification. For access parameters
2296 -- there are no subtypes involved.
2298 Rewrite (Parameter_Type (Param_Spec),
2300 (Base_Type (Entity (Parameter_Type (Param_Spec))), Loc));
2303 if No (Expr_List) then
2304 Expr_List := New_List;
2307 Append_To (Expr_List,
2308 Make_Identifier (Loc,
2309 Chars => Chars (Defining_Identifier (Param_Spec))));
2311 -- The expressions in the attribute reference are not freeze
2312 -- points. Neither is the attribute as a whole, see below.
2314 Set_Must_Not_Freeze (Last (Expr_List));
2319 -- Immediate error if too many formals. Other mismatches in numbers
2320 -- of number of types of parameters are detected when we analyze the
2321 -- body of the subprogram that we construct.
2323 if Form_Num > 2 then
2324 Error_Msg_N ("too many formals for attribute", N);
2326 -- Error if the attribute reference has expressions that look
2327 -- like formal parameters.
2329 elsif Present (Expressions (Nam)) then
2330 Error_Msg_N ("illegal expressions in attribute reference", Nam);
2333 Aname = Name_Compose or else
2334 Aname = Name_Exponent or else
2335 Aname = Name_Leading_Part or else
2336 Aname = Name_Pos or else
2337 Aname = Name_Round or else
2338 Aname = Name_Scaling or else
2341 if Nkind (N) = N_Subprogram_Renaming_Declaration
2342 and then Present (Corresponding_Formal_Spec (N))
2345 ("generic actual cannot be attribute involving universal type",
2349 ("attribute involving a universal type cannot be renamed",
2354 -- AST_Entry is an odd case. It doesn't really make much sense to
2355 -- allow it to be renamed, but that's the DEC rule, so we have to
2356 -- do it right. The point is that the AST_Entry call should be made
2357 -- now, and what the function will return is the returned value.
2359 -- Note that there is no Expr_List in this case anyway
2361 if Aname = Name_AST_Entry then
2367 Ent := Make_Defining_Identifier (Loc, New_Internal_Name ('R'));
2370 Make_Object_Declaration (Loc,
2371 Defining_Identifier => Ent,
2372 Object_Definition =>
2373 New_Occurrence_Of (RTE (RE_AST_Handler), Loc),
2375 Constant_Present => True);
2377 Set_Assignment_OK (Decl, True);
2378 Insert_Action (N, Decl);
2379 Attr_Node := Make_Identifier (Loc, Chars (Ent));
2382 -- For all other attributes, we rewrite the attribute node to have
2383 -- a list of expressions corresponding to the subprogram formals.
2384 -- A renaming declaration is not a freeze point, and the analysis of
2385 -- the attribute reference should not freeze the type of the prefix.
2389 Make_Attribute_Reference (Loc,
2390 Prefix => Prefix (Nam),
2391 Attribute_Name => Aname,
2392 Expressions => Expr_List);
2394 Set_Must_Not_Freeze (Attr_Node);
2395 Set_Must_Not_Freeze (Prefix (Nam));
2398 -- Case of renaming a function
2400 if Nkind (Spec) = N_Function_Specification then
2401 if Is_Procedure_Attribute_Name (Aname) then
2402 Error_Msg_N ("attribute can only be renamed as procedure", Nam);
2406 Find_Type (Result_Definition (Spec));
2407 Rewrite (Result_Definition (Spec),
2409 Base_Type (Entity (Result_Definition (Spec))), Loc));
2412 Make_Subprogram_Body (Loc,
2413 Specification => Spec,
2414 Declarations => New_List,
2415 Handled_Statement_Sequence =>
2416 Make_Handled_Sequence_Of_Statements (Loc,
2417 Statements => New_List (
2418 Make_Simple_Return_Statement (Loc,
2419 Expression => Attr_Node))));
2421 -- Case of renaming a procedure
2424 if not Is_Procedure_Attribute_Name (Aname) then
2425 Error_Msg_N ("attribute can only be renamed as function", Nam);
2430 Make_Subprogram_Body (Loc,
2431 Specification => Spec,
2432 Declarations => New_List,
2433 Handled_Statement_Sequence =>
2434 Make_Handled_Sequence_Of_Statements (Loc,
2435 Statements => New_List (Attr_Node)));
2438 -- In case of tagged types we add the body of the generated function to
2439 -- the freezing actions of the type (because in the general case such
2440 -- type is still not frozen). We exclude from this processing generic
2441 -- formal subprograms found in instantiations and AST_Entry renamings.
2443 if not Present (Corresponding_Formal_Spec (N))
2444 and then Etype (Nam) /= RTE (RE_AST_Handler)
2447 P : constant Entity_Id := Prefix (Nam);
2452 if Is_Tagged_Type (Etype (P)) then
2453 Ensure_Freeze_Node (Etype (P));
2454 Append_Freeze_Action (Etype (P), Body_Node);
2456 Rewrite (N, Body_Node);
2458 Set_Etype (New_S, Base_Type (Etype (New_S)));
2462 -- Generic formal subprograms or AST_Handler renaming
2465 Rewrite (N, Body_Node);
2467 Set_Etype (New_S, Base_Type (Etype (New_S)));
2470 if Is_Compilation_Unit (New_S) then
2472 ("a library unit can only rename another library unit", N);
2475 -- We suppress elaboration warnings for the resulting entity, since
2476 -- clearly they are not needed, and more particularly, in the case
2477 -- of a generic formal subprogram, the resulting entity can appear
2478 -- after the instantiation itself, and thus look like a bogus case
2479 -- of access before elaboration.
2481 Set_Suppress_Elaboration_Warnings (New_S);
2483 end Attribute_Renaming;
2485 ----------------------
2486 -- Chain_Use_Clause --
2487 ----------------------
2489 procedure Chain_Use_Clause (N : Node_Id) is
2491 Level : Int := Scope_Stack.Last;
2494 if not Is_Compilation_Unit (Current_Scope)
2495 or else not Is_Child_Unit (Current_Scope)
2497 null; -- Common case
2499 elsif Defining_Entity (Parent (N)) = Current_Scope then
2500 null; -- Common case for compilation unit
2503 -- If declaration appears in some other scope, it must be in some
2504 -- parent unit when compiling a child.
2506 Pack := Defining_Entity (Parent (N));
2507 if not In_Open_Scopes (Pack) then
2508 null; -- default as well
2511 -- Find entry for parent unit in scope stack
2513 while Scope_Stack.Table (Level).Entity /= Pack loop
2519 Set_Next_Use_Clause (N,
2520 Scope_Stack.Table (Level).First_Use_Clause);
2521 Scope_Stack.Table (Level).First_Use_Clause := N;
2522 end Chain_Use_Clause;
2524 ---------------------------
2525 -- Check_Frozen_Renaming --
2526 ---------------------------
2528 procedure Check_Frozen_Renaming (N : Node_Id; Subp : Entity_Id) is
2534 and then not Has_Completion (Subp)
2538 (Parent (Declaration_Node (Subp)), Defining_Entity (N));
2540 if Is_Entity_Name (Name (N)) then
2541 Old_S := Entity (Name (N));
2543 if not Is_Frozen (Old_S)
2544 and then Operating_Mode /= Check_Semantics
2546 Append_Freeze_Action (Old_S, B_Node);
2548 Insert_After (N, B_Node);
2552 if Is_Intrinsic_Subprogram (Old_S)
2553 and then not In_Instance
2556 ("subprogram used in renaming_as_body cannot be intrinsic",
2561 Insert_After (N, B_Node);
2565 end Check_Frozen_Renaming;
2567 -----------------------------------
2568 -- Check_In_Previous_With_Clause --
2569 -----------------------------------
2571 procedure Check_In_Previous_With_Clause
2575 Pack : constant Entity_Id := Entity (Original_Node (Nam));
2580 Item := First (Context_Items (Parent (N)));
2582 while Present (Item)
2585 if Nkind (Item) = N_With_Clause
2587 -- Protect the frontend against previous critical errors
2589 and then Nkind (Name (Item)) /= N_Selected_Component
2590 and then Entity (Name (Item)) = Pack
2594 -- Find root library unit in with_clause
2596 while Nkind (Par) = N_Expanded_Name loop
2597 Par := Prefix (Par);
2600 if Is_Child_Unit (Entity (Original_Node (Par))) then
2602 ("& is not directly visible", Par, Entity (Par));
2611 -- On exit, package is not mentioned in a previous with_clause.
2612 -- Check if its prefix is.
2614 if Nkind (Nam) = N_Expanded_Name then
2615 Check_In_Previous_With_Clause (N, Prefix (Nam));
2617 elsif Pack /= Any_Id then
2618 Error_Msg_NE ("& is not visible", Nam, Pack);
2620 end Check_In_Previous_With_Clause;
2622 ---------------------------------
2623 -- Check_Library_Unit_Renaming --
2624 ---------------------------------
2626 procedure Check_Library_Unit_Renaming (N : Node_Id; Old_E : Entity_Id) is
2630 if Nkind (Parent (N)) /= N_Compilation_Unit then
2633 -- Check for library unit. Note that we used to check for the scope
2634 -- being Standard here, but that was wrong for Standard itself.
2636 elsif not Is_Compilation_Unit (Old_E)
2637 and then not Is_Child_Unit (Old_E)
2639 Error_Msg_N ("renamed unit must be a library unit", Name (N));
2641 -- Entities defined in Standard (operators and boolean literals) cannot
2642 -- be renamed as library units.
2644 elsif Scope (Old_E) = Standard_Standard
2645 and then Sloc (Old_E) = Standard_Location
2647 Error_Msg_N ("renamed unit must be a library unit", Name (N));
2649 elsif Present (Parent_Spec (N))
2650 and then Nkind (Unit (Parent_Spec (N))) = N_Generic_Package_Declaration
2651 and then not Is_Child_Unit (Old_E)
2654 ("renamed unit must be a child unit of generic parent", Name (N));
2656 elsif Nkind (N) in N_Generic_Renaming_Declaration
2657 and then Nkind (Name (N)) = N_Expanded_Name
2658 and then Is_Generic_Instance (Entity (Prefix (Name (N))))
2659 and then Is_Generic_Unit (Old_E)
2662 ("renamed generic unit must be a library unit", Name (N));
2664 elsif Ekind (Old_E) = E_Package
2665 or else Ekind (Old_E) = E_Generic_Package
2667 -- Inherit categorization flags
2669 New_E := Defining_Entity (N);
2670 Set_Is_Pure (New_E, Is_Pure (Old_E));
2671 Set_Is_Preelaborated (New_E, Is_Preelaborated (Old_E));
2672 Set_Is_Remote_Call_Interface (New_E,
2673 Is_Remote_Call_Interface (Old_E));
2674 Set_Is_Remote_Types (New_E, Is_Remote_Types (Old_E));
2675 Set_Is_Shared_Passive (New_E, Is_Shared_Passive (Old_E));
2677 end Check_Library_Unit_Renaming;
2683 procedure End_Scope is
2689 Id := First_Entity (Current_Scope);
2690 while Present (Id) loop
2691 -- An entity in the current scope is not necessarily the first one
2692 -- on its homonym chain. Find its predecessor if any,
2693 -- If it is an internal entity, it will not be in the visibility
2694 -- chain altogether, and there is nothing to unchain.
2696 if Id /= Current_Entity (Id) then
2697 Prev := Current_Entity (Id);
2698 while Present (Prev)
2699 and then Present (Homonym (Prev))
2700 and then Homonym (Prev) /= Id
2702 Prev := Homonym (Prev);
2705 -- Skip to end of loop if Id is not in the visibility chain
2707 if No (Prev) or else Homonym (Prev) /= Id then
2715 Set_Is_Immediately_Visible (Id, False);
2717 Outer := Homonym (Id);
2718 while Present (Outer) and then Scope (Outer) = Current_Scope loop
2719 Outer := Homonym (Outer);
2722 -- Reset homonym link of other entities, but do not modify link
2723 -- between entities in current scope, so that the back-end can have
2724 -- a proper count of local overloadings.
2727 Set_Name_Entity_Id (Chars (Id), Outer);
2729 elsif Scope (Prev) /= Scope (Id) then
2730 Set_Homonym (Prev, Outer);
2737 -- If the scope generated freeze actions, place them before the
2738 -- current declaration and analyze them. Type declarations and
2739 -- the bodies of initialization procedures can generate such nodes.
2740 -- We follow the parent chain until we reach a list node, which is
2741 -- the enclosing list of declarations. If the list appears within
2742 -- a protected definition, move freeze nodes outside the protected
2746 (Scope_Stack.Table (Scope_Stack.Last).Pending_Freeze_Actions)
2750 L : constant List_Id := Scope_Stack.Table
2751 (Scope_Stack.Last).Pending_Freeze_Actions;
2754 if Is_Itype (Current_Scope) then
2755 Decl := Associated_Node_For_Itype (Current_Scope);
2757 Decl := Parent (Current_Scope);
2762 while not (Is_List_Member (Decl))
2763 or else Nkind (Parent (Decl)) = N_Protected_Definition
2764 or else Nkind (Parent (Decl)) = N_Task_Definition
2766 Decl := Parent (Decl);
2769 Insert_List_Before_And_Analyze (Decl, L);
2778 ---------------------
2779 -- End_Use_Clauses --
2780 ---------------------
2782 procedure End_Use_Clauses (Clause : Node_Id) is
2786 -- Remove Use_Type clauses first, because they affect the
2787 -- visibility of operators in subsequent used packages.
2790 while Present (U) loop
2791 if Nkind (U) = N_Use_Type_Clause then
2795 Next_Use_Clause (U);
2799 while Present (U) loop
2800 if Nkind (U) = N_Use_Package_Clause then
2801 End_Use_Package (U);
2804 Next_Use_Clause (U);
2806 end End_Use_Clauses;
2808 ---------------------
2809 -- End_Use_Package --
2810 ---------------------
2812 procedure End_Use_Package (N : Node_Id) is
2813 Pack_Name : Node_Id;
2818 function Is_Primitive_Operator
2820 F : Entity_Id) return Boolean;
2821 -- Check whether Op is a primitive operator of a use-visible type
2823 ---------------------------
2824 -- Is_Primitive_Operator --
2825 ---------------------------
2827 function Is_Primitive_Operator
2829 F : Entity_Id) return Boolean
2831 T : constant Entity_Id := Etype (F);
2834 and then Scope (T) = Scope (Op);
2835 end Is_Primitive_Operator;
2837 -- Start of processing for End_Use_Package
2840 Pack_Name := First (Names (N));
2841 while Present (Pack_Name) loop
2842 Pack := Entity (Pack_Name);
2844 if Ekind (Pack) = E_Package then
2845 if In_Open_Scopes (Pack) then
2848 elsif not Redundant_Use (Pack_Name) then
2849 Set_In_Use (Pack, False);
2850 Set_Current_Use_Clause (Pack, Empty);
2852 Id := First_Entity (Pack);
2853 while Present (Id) loop
2855 -- Preserve use-visibility of operators that are primitive
2856 -- operators of a type that is use-visible through an active
2859 if Nkind (Id) = N_Defining_Operator_Symbol
2861 (Is_Primitive_Operator (Id, First_Formal (Id))
2863 (Present (Next_Formal (First_Formal (Id)))
2865 Is_Primitive_Operator
2866 (Id, Next_Formal (First_Formal (Id)))))
2871 Set_Is_Potentially_Use_Visible (Id, False);
2874 if Is_Private_Type (Id)
2875 and then Present (Full_View (Id))
2877 Set_Is_Potentially_Use_Visible (Full_View (Id), False);
2883 if Present (Renamed_Object (Pack)) then
2884 Set_In_Use (Renamed_Object (Pack), False);
2885 Set_Current_Use_Clause (Renamed_Object (Pack), Empty);
2888 if Chars (Pack) = Name_System
2889 and then Scope (Pack) = Standard_Standard
2890 and then Present_System_Aux
2892 Id := First_Entity (System_Aux_Id);
2893 while Present (Id) loop
2894 Set_Is_Potentially_Use_Visible (Id, False);
2896 if Is_Private_Type (Id)
2897 and then Present (Full_View (Id))
2899 Set_Is_Potentially_Use_Visible (Full_View (Id), False);
2905 Set_In_Use (System_Aux_Id, False);
2909 Set_Redundant_Use (Pack_Name, False);
2916 if Present (Hidden_By_Use_Clause (N)) then
2917 Elmt := First_Elmt (Hidden_By_Use_Clause (N));
2918 while Present (Elmt) loop
2919 Set_Is_Immediately_Visible (Node (Elmt));
2923 Set_Hidden_By_Use_Clause (N, No_Elist);
2925 end End_Use_Package;
2931 procedure End_Use_Type (N : Node_Id) is
2938 Id := First (Subtype_Marks (N));
2939 while Present (Id) loop
2941 -- A call to rtsfind may occur while analyzing a use_type clause,
2942 -- in which case the type marks are not resolved yet, and there is
2943 -- nothing to remove.
2945 if not Is_Entity_Name (Id)
2946 or else No (Entity (Id))
2954 or else From_With_Type (T)
2958 -- Note that the use_Type clause may mention a subtype of the type
2959 -- whose primitive operations have been made visible. Here as
2960 -- elsewhere, it is the base type that matters for visibility.
2962 elsif In_Open_Scopes (Scope (Base_Type (T))) then
2965 elsif not Redundant_Use (Id) then
2966 Set_In_Use (T, False);
2967 Set_In_Use (Base_Type (T), False);
2968 Op_List := Collect_Primitive_Operations (T);
2970 Elmt := First_Elmt (Op_List);
2971 while Present (Elmt) loop
2972 if Nkind (Node (Elmt)) = N_Defining_Operator_Symbol then
2973 Set_Is_Potentially_Use_Visible (Node (Elmt), False);
2985 ----------------------
2986 -- Find_Direct_Name --
2987 ----------------------
2989 procedure Find_Direct_Name (N : Node_Id) is
2994 Inst : Entity_Id := Empty;
2995 -- Enclosing instance, if any
2997 Homonyms : Entity_Id;
2998 -- Saves start of homonym chain
3000 Nvis_Entity : Boolean;
3001 -- Set True to indicate that at there is at least one entity on the
3002 -- homonym chain which, while not visible, is visible enough from the
3003 -- user point of view to warrant an error message of "not visible"
3004 -- rather than undefined.
3006 Nvis_Is_Private_Subprg : Boolean := False;
3007 -- Ada 2005 (AI-262): Set True to indicate that a form of Beaujolais
3008 -- effect concerning library subprograms has been detected. Used to
3009 -- generate the precise error message.
3011 function From_Actual_Package (E : Entity_Id) return Boolean;
3012 -- Returns true if the entity is declared in a package that is
3013 -- an actual for a formal package of the current instance. Such an
3014 -- entity requires special handling because it may be use-visible
3015 -- but hides directly visible entities defined outside the instance.
3017 function Known_But_Invisible (E : Entity_Id) return Boolean;
3018 -- This function determines whether the entity E (which is not
3019 -- visible) can reasonably be considered to be known to the writer
3020 -- of the reference. This is a heuristic test, used only for the
3021 -- purposes of figuring out whether we prefer to complain that an
3022 -- entity is undefined or invisible (and identify the declaration
3023 -- of the invisible entity in the latter case). The point here is
3024 -- that we don't want to complain that something is invisible and
3025 -- then point to something entirely mysterious to the writer.
3027 procedure Nvis_Messages;
3028 -- Called if there are no visible entries for N, but there is at least
3029 -- one non-directly visible, or hidden declaration. This procedure
3030 -- outputs an appropriate set of error messages.
3032 procedure Undefined (Nvis : Boolean);
3033 -- This function is called if the current node has no corresponding
3034 -- visible entity or entities. The value set in Msg indicates whether
3035 -- an error message was generated (multiple error messages for the
3036 -- same variable are generally suppressed, see body for details).
3037 -- Msg is True if an error message was generated, False if not. This
3038 -- value is used by the caller to determine whether or not to output
3039 -- additional messages where appropriate. The parameter is set False
3040 -- to get the message "X is undefined", and True to get the message
3041 -- "X is not visible".
3043 -------------------------
3044 -- From_Actual_Package --
3045 -------------------------
3047 function From_Actual_Package (E : Entity_Id) return Boolean is
3048 Scop : constant Entity_Id := Scope (E);
3052 if not In_Instance then
3055 Inst := Current_Scope;
3056 while Present (Inst)
3057 and then Ekind (Inst) /= E_Package
3058 and then not Is_Generic_Instance (Inst)
3060 Inst := Scope (Inst);
3067 Act := First_Entity (Inst);
3068 while Present (Act) loop
3069 if Ekind (Act) = E_Package then
3071 -- Check for end of actuals list
3073 if Renamed_Object (Act) = Inst then
3076 elsif Present (Associated_Formal_Package (Act))
3077 and then Renamed_Object (Act) = Scop
3079 -- Entity comes from (instance of) formal package
3094 end From_Actual_Package;
3096 -------------------------
3097 -- Known_But_Invisible --
3098 -------------------------
3100 function Known_But_Invisible (E : Entity_Id) return Boolean is
3101 Fname : File_Name_Type;
3104 -- Entities in Standard are always considered to be known
3106 if Sloc (E) <= Standard_Location then
3109 -- An entity that does not come from source is always considered
3110 -- to be unknown, since it is an artifact of code expansion.
3112 elsif not Comes_From_Source (E) then
3115 -- In gnat internal mode, we consider all entities known
3117 elsif GNAT_Mode then
3121 -- Here we have an entity that is not from package Standard, and
3122 -- which comes from Source. See if it comes from an internal file.
3124 Fname := Unit_File_Name (Get_Source_Unit (E));
3126 -- Case of from internal file
3128 if Is_Internal_File_Name (Fname) then
3130 -- Private part entities in internal files are never considered
3131 -- to be known to the writer of normal application code.
3133 if Is_Hidden (E) then
3137 -- Entities from System packages other than System and
3138 -- System.Storage_Elements are not considered to be known.
3139 -- System.Auxxxx files are also considered known to the user.
3141 -- Should refine this at some point to generally distinguish
3142 -- between known and unknown internal files ???
3144 Get_Name_String (Fname);
3149 Name_Buffer (1 .. 2) /= "s-"
3151 Name_Buffer (3 .. 8) = "stoele"
3153 Name_Buffer (3 .. 5) = "aux";
3155 -- If not an internal file, then entity is definitely known,
3156 -- even if it is in a private part (the message generated will
3157 -- note that it is in a private part)
3162 end Known_But_Invisible;
3168 procedure Nvis_Messages is
3169 Comp_Unit : Node_Id;
3171 Hidden : Boolean := False;
3175 -- Ada 2005 (AI-262): Generate a precise error concerning the
3176 -- Beaujolais effect that was previously detected
3178 if Nvis_Is_Private_Subprg then
3180 pragma Assert (Nkind (E2) = N_Defining_Identifier
3181 and then Ekind (E2) = E_Function
3182 and then Scope (E2) = Standard_Standard
3183 and then Has_Private_With (E2));
3185 -- Find the sloc corresponding to the private with'ed unit
3187 Comp_Unit := Cunit (Current_Sem_Unit);
3188 Error_Msg_Sloc := No_Location;
3190 Item := First (Context_Items (Comp_Unit));
3191 while Present (Item) loop
3192 if Nkind (Item) = N_With_Clause
3193 and then Private_Present (Item)
3194 and then Entity (Name (Item)) = E2
3196 Error_Msg_Sloc := Sloc (Item);
3203 pragma Assert (Error_Msg_Sloc /= No_Location);
3205 Error_Msg_N ("(Ada 2005): hidden by private with clause #", N);
3209 Undefined (Nvis => True);
3213 -- First loop does hidden declarations
3216 while Present (Ent) loop
3217 if Is_Potentially_Use_Visible (Ent) then
3219 Error_Msg_N ("multiple use clauses cause hiding!", N);
3223 Error_Msg_Sloc := Sloc (Ent);
3224 Error_Msg_N ("hidden declaration#!", N);
3227 Ent := Homonym (Ent);
3230 -- If we found hidden declarations, then that's enough, don't
3231 -- bother looking for non-visible declarations as well.
3237 -- Second loop does non-directly visible declarations
3240 while Present (Ent) loop
3241 if not Is_Potentially_Use_Visible (Ent) then
3243 -- Do not bother the user with unknown entities
3245 if not Known_But_Invisible (Ent) then
3249 Error_Msg_Sloc := Sloc (Ent);
3251 -- Output message noting that there is a non-visible
3252 -- declaration, distinguishing the private part case.
3254 if Is_Hidden (Ent) then
3255 Error_Msg_N ("non-visible (private) declaration#!", N);
3257 Error_Msg_N ("non-visible declaration#!", N);
3259 if Is_Compilation_Unit (Ent)
3261 Nkind (Parent (Parent (N))) = N_Use_Package_Clause
3263 Error_Msg_Qual_Level := 99;
3264 Error_Msg_NE ("\\missing `WITH &;`", N, Ent);
3265 Error_Msg_Qual_Level := 0;
3269 -- Set entity and its containing package as referenced. We
3270 -- can't be sure of this, but this seems a better choice
3271 -- to avoid unused entity messages.
3273 if Comes_From_Source (Ent) then
3274 Set_Referenced (Ent);
3275 Set_Referenced (Cunit_Entity (Get_Source_Unit (Ent)));
3280 Ent := Homonym (Ent);
3289 procedure Undefined (Nvis : Boolean) is
3290 Emsg : Error_Msg_Id;
3293 -- We should never find an undefined internal name. If we do, then
3294 -- see if we have previous errors. If so, ignore on the grounds that
3295 -- it is probably a cascaded message (e.g. a block label from a badly
3296 -- formed block). If no previous errors, then we have a real internal
3297 -- error of some kind so raise an exception.
3299 if Is_Internal_Name (Chars (N)) then
3300 if Total_Errors_Detected /= 0 then
3303 raise Program_Error;
3307 -- A very specialized error check, if the undefined variable is
3308 -- a case tag, and the case type is an enumeration type, check
3309 -- for a possible misspelling, and if so, modify the identifier
3311 -- Named aggregate should also be handled similarly ???
3313 if Nkind (N) = N_Identifier
3314 and then Nkind (Parent (N)) = N_Case_Statement_Alternative
3316 Get_Name_String (Chars (N));
3319 Case_Str : constant String := Name_Buffer (1 .. Name_Len);
3320 Case_Stm : constant Node_Id := Parent (Parent (N));
3321 Case_Typ : constant Entity_Id := Etype (Expression (Case_Stm));
3322 Case_Rtp : constant Entity_Id := Root_Type (Case_Typ);
3327 if Is_Enumeration_Type (Case_Typ)
3328 and then Case_Rtp /= Standard_Character
3329 and then Case_Rtp /= Standard_Wide_Character
3330 and then Case_Rtp /= Standard_Wide_Wide_Character
3332 Lit := First_Literal (Case_Typ);
3333 Get_Name_String (Chars (Lit));
3335 if Chars (Lit) /= Chars (N)
3336 and then Is_Bad_Spelling_Of
3337 (Case_Str, Name_Buffer (1 .. Name_Len))
3339 Error_Msg_Node_2 := Lit;
3341 ("& is undefined, assume misspelling of &", N);
3342 Rewrite (N, New_Occurrence_Of (Lit, Sloc (N)));
3346 Lit := Next_Literal (Lit);
3351 -- Normal processing
3353 Set_Entity (N, Any_Id);
3354 Set_Etype (N, Any_Type);
3356 -- We use the table Urefs to keep track of entities for which we
3357 -- have issued errors for undefined references. Multiple errors
3358 -- for a single name are normally suppressed, however we modify
3359 -- the error message to alert the programmer to this effect.
3361 for J in Urefs.First .. Urefs.Last loop
3362 if Chars (N) = Chars (Urefs.Table (J).Node) then
3363 if Urefs.Table (J).Err /= No_Error_Msg
3364 and then Sloc (N) /= Urefs.Table (J).Loc
3366 Error_Msg_Node_1 := Urefs.Table (J).Node;
3368 if Urefs.Table (J).Nvis then
3369 Change_Error_Text (Urefs.Table (J).Err,
3370 "& is not visible (more references follow)");
3372 Change_Error_Text (Urefs.Table (J).Err,
3373 "& is undefined (more references follow)");
3376 Urefs.Table (J).Err := No_Error_Msg;
3379 -- Although we will set Msg False, and thus suppress the
3380 -- message, we also set Error_Posted True, to avoid any
3381 -- cascaded messages resulting from the undefined reference.
3384 Set_Error_Posted (N, True);
3389 -- If entry not found, this is first undefined occurrence
3392 Error_Msg_N ("& is not visible!", N);
3396 Error_Msg_N ("& is undefined!", N);
3399 -- A very bizarre special check, if the undefined identifier
3400 -- is put or put_line, then add a special error message (since
3401 -- this is a very common error for beginners to make).
3403 if Chars (N) = Name_Put or else Chars (N) = Name_Put_Line then
3405 ("\\possible missing `WITH Ada.Text_'I'O; " &
3406 "USE Ada.Text_'I'O`!", N);
3408 -- Another special check if N is the prefix of a selected
3409 -- component which is a known unit, add message complaining
3410 -- about missing with for this unit.
3412 elsif Nkind (Parent (N)) = N_Selected_Component
3413 and then N = Prefix (Parent (N))
3414 and then Is_Known_Unit (Parent (N))
3416 Error_Msg_Node_2 := Selector_Name (Parent (N));
3417 Error_Msg_N ("\\missing `WITH &.&;`", Prefix (Parent (N)));
3420 -- Now check for possible misspellings
3422 Get_Name_String (Chars (N));
3426 Ematch : Entity_Id := Empty;
3428 Last_Name_Id : constant Name_Id :=
3429 Name_Id (Nat (First_Name_Id) +
3430 Name_Entries_Count - 1);
3432 S : constant String (1 .. Name_Len) :=
3433 Name_Buffer (1 .. Name_Len);
3436 for N in First_Name_Id .. Last_Name_Id loop
3437 E := Get_Name_Entity_Id (N);
3440 and then (Is_Immediately_Visible (E)
3442 Is_Potentially_Use_Visible (E))
3444 Get_Name_String (N);
3446 if Is_Bad_Spelling_Of
3447 (S, Name_Buffer (1 .. Name_Len))
3455 if Present (Ematch) then
3456 Error_Msg_NE ("\possible misspelling of&", N, Ematch);
3461 -- Make entry in undefined references table unless the full errors
3462 -- switch is set, in which case by refraining from generating the
3463 -- table entry, we guarantee that we get an error message for every
3464 -- undefined reference.
3466 if not All_Errors_Mode then
3477 -- Start of processing for Find_Direct_Name
3480 -- If the entity pointer is already set, this is an internal node, or
3481 -- a node that is analyzed more than once, after a tree modification.
3482 -- In such a case there is no resolution to perform, just set the type.
3484 if Present (Entity (N)) then
3485 if Is_Type (Entity (N)) then
3486 Set_Etype (N, Entity (N));
3490 Entyp : constant Entity_Id := Etype (Entity (N));
3493 -- One special case here. If the Etype field is already set,
3494 -- and references the packed array type corresponding to the
3495 -- etype of the referenced entity, then leave it alone. This
3496 -- happens for trees generated from Exp_Pakd, where expressions
3497 -- can be deliberately "mis-typed" to the packed array type.
3499 if Is_Array_Type (Entyp)
3500 and then Is_Packed (Entyp)
3501 and then Present (Etype (N))
3502 and then Etype (N) = Packed_Array_Type (Entyp)
3506 -- If not that special case, then just reset the Etype
3509 Set_Etype (N, Etype (Entity (N)));
3517 -- Here if Entity pointer was not set, we need full visibility analysis
3518 -- First we generate debugging output if the debug E flag is set.
3520 if Debug_Flag_E then
3521 Write_Str ("Looking for ");
3522 Write_Name (Chars (N));
3526 Homonyms := Current_Entity (N);
3527 Nvis_Entity := False;
3530 while Present (E) loop
3532 -- If entity is immediately visible or potentially use
3533 -- visible, then process the entity and we are done.
3535 if Is_Immediately_Visible (E) then
3536 goto Immediately_Visible_Entity;
3538 elsif Is_Potentially_Use_Visible (E) then
3539 goto Potentially_Use_Visible_Entity;
3541 -- Note if a known but invisible entity encountered
3543 elsif Known_But_Invisible (E) then
3544 Nvis_Entity := True;
3547 -- Move to next entity in chain and continue search
3552 -- If no entries on homonym chain that were potentially visible,
3553 -- and no entities reasonably considered as non-visible, then
3554 -- we have a plain undefined reference, with no additional
3555 -- explanation required!
3557 if not Nvis_Entity then
3558 Undefined (Nvis => False);
3560 -- Otherwise there is at least one entry on the homonym chain that
3561 -- is reasonably considered as being known and non-visible.
3569 -- Processing for a potentially use visible entry found. We must search
3570 -- the rest of the homonym chain for two reasons. First, if there is a
3571 -- directly visible entry, then none of the potentially use-visible
3572 -- entities are directly visible (RM 8.4(10)). Second, we need to check
3573 -- for the case of multiple potentially use-visible entries hiding one
3574 -- another and as a result being non-directly visible (RM 8.4(11)).
3576 <<Potentially_Use_Visible_Entity>> declare
3577 Only_One_Visible : Boolean := True;
3578 All_Overloadable : Boolean := Is_Overloadable (E);
3582 while Present (E2) loop
3583 if Is_Immediately_Visible (E2) then
3585 -- If the use-visible entity comes from the actual for a
3586 -- formal package, it hides a directly visible entity from
3587 -- outside the instance.
3589 if From_Actual_Package (E)
3590 and then Scope_Depth (E2) < Scope_Depth (Inst)
3595 goto Immediately_Visible_Entity;
3598 elsif Is_Potentially_Use_Visible (E2) then
3599 Only_One_Visible := False;
3600 All_Overloadable := All_Overloadable and Is_Overloadable (E2);
3602 -- Ada 2005 (AI-262): Protect against a form of Beujolais effect
3603 -- that can occurr in private_with clauses. Example:
3606 -- private with B; package A is
3607 -- package C is function B return Integer;
3609 -- V1 : Integer := B;
3610 -- private function B return Integer;
3611 -- V2 : Integer := B;
3614 -- V1 resolves to A.B, but V2 resolves to library unit B
3616 elsif Ekind (E2) = E_Function
3617 and then Scope (E2) = Standard_Standard
3618 and then Has_Private_With (E2)
3620 Only_One_Visible := False;
3621 All_Overloadable := False;
3622 Nvis_Is_Private_Subprg := True;
3629 -- On falling through this loop, we have checked that there are no
3630 -- immediately visible entities. Only_One_Visible is set if exactly
3631 -- one potentially use visible entity exists. All_Overloadable is
3632 -- set if all the potentially use visible entities are overloadable.
3633 -- The condition for legality is that either there is one potentially
3634 -- use visible entity, or if there is more than one, then all of them
3635 -- are overloadable.
3637 if Only_One_Visible or All_Overloadable then
3640 -- If there is more than one potentially use-visible entity and at
3641 -- least one of them non-overloadable, we have an error (RM 8.4(11).
3642 -- Note that E points to the first such entity on the homonym list.
3643 -- Special case: if one of the entities is declared in an actual
3644 -- package, it was visible in the generic, and takes precedence over
3645 -- other entities that are potentially use-visible. Same if it is
3646 -- declared in a local instantiation of the current instance.
3651 -- Find current instance
3653 Inst := Current_Scope;
3654 while Present (Inst)
3655 and then Inst /= Standard_Standard
3657 if Is_Generic_Instance (Inst) then
3661 Inst := Scope (Inst);
3665 while Present (E2) loop
3666 if From_Actual_Package (E2)
3668 (Is_Generic_Instance (Scope (E2))
3669 and then Scope_Depth (Scope (E2)) > Scope_Depth (Inst))
3682 Is_Predefined_File_Name (Unit_File_Name (Current_Sem_Unit))
3684 -- A use-clause in the body of a system file creates conflict
3685 -- with some entity in a user scope, while rtsfind is active.
3686 -- Keep only the entity coming from another predefined unit.
3689 while Present (E2) loop
3690 if Is_Predefined_File_Name
3691 (Unit_File_Name (Get_Source_Unit (Sloc (E2))))
3700 -- Entity must exist because predefined unit is correct
3702 raise Program_Error;
3711 -- Come here with E set to the first immediately visible entity on
3712 -- the homonym chain. This is the one we want unless there is another
3713 -- immediately visible entity further on in the chain for a more
3714 -- inner scope (RM 8.3(8)).
3716 <<Immediately_Visible_Entity>> declare
3721 -- Find scope level of initial entity. When compiling through
3722 -- Rtsfind, the previous context is not completely invisible, and
3723 -- an outer entity may appear on the chain, whose scope is below
3724 -- the entry for Standard that delimits the current scope stack.
3725 -- Indicate that the level for this spurious entry is outside of
3726 -- the current scope stack.
3728 Level := Scope_Stack.Last;
3730 Scop := Scope_Stack.Table (Level).Entity;
3731 exit when Scop = Scope (E);
3733 exit when Scop = Standard_Standard;
3736 -- Now search remainder of homonym chain for more inner entry
3737 -- If the entity is Standard itself, it has no scope, and we
3738 -- compare it with the stack entry directly.
3741 while Present (E2) loop
3742 if Is_Immediately_Visible (E2) then
3744 -- If a generic package contains a local declaration that
3745 -- has the same name as the generic, there may be a visibility
3746 -- conflict in an instance, where the local declaration must
3747 -- also hide the name of the corresponding package renaming.
3748 -- We check explicitly for a package declared by a renaming,
3749 -- whose renamed entity is an instance that is on the scope
3750 -- stack, and that contains a homonym in the same scope. Once
3751 -- we have found it, we know that the package renaming is not
3752 -- immediately visible, and that the identifier denotes the
3753 -- other entity (and its homonyms if overloaded).
3755 if Scope (E) = Scope (E2)
3756 and then Ekind (E) = E_Package
3757 and then Present (Renamed_Object (E))
3758 and then Is_Generic_Instance (Renamed_Object (E))
3759 and then In_Open_Scopes (Renamed_Object (E))
3760 and then Comes_From_Source (N)
3762 Set_Is_Immediately_Visible (E, False);
3766 for J in Level + 1 .. Scope_Stack.Last loop
3767 if Scope_Stack.Table (J).Entity = Scope (E2)
3768 or else Scope_Stack.Table (J).Entity = E2
3781 -- At the end of that loop, E is the innermost immediately
3782 -- visible entity, so we are all set.
3785 -- Come here with entity found, and stored in E
3789 if Comes_From_Source (N)
3790 and then Is_Remote_Access_To_Subprogram_Type (E)
3791 and then Expander_Active
3792 and then Get_PCS_Name /= Name_No_DSA
3795 New_Occurrence_Of (Equivalent_Type (E), Sloc (N)));
3800 -- Why no Style_Check here???
3805 Set_Etype (N, Get_Full_View (Etype (E)));
3808 if Debug_Flag_E then
3809 Write_Str (" found ");
3810 Write_Entity_Info (E, " ");
3813 -- If the Ekind of the entity is Void, it means that all homonyms
3814 -- are hidden from all visibility (RM 8.3(5,14-20)). However, this
3815 -- test is skipped if the current scope is a record and the name is
3816 -- a pragma argument expression (case of Atomic and Volatile pragmas
3817 -- and possibly other similar pragmas added later, which are allowed
3818 -- to reference components in the current record).
3820 if Ekind (E) = E_Void
3822 (not Is_Record_Type (Current_Scope)
3823 or else Nkind (Parent (N)) /= N_Pragma_Argument_Association)
3825 Premature_Usage (N);
3827 -- If the entity is overloadable, collect all interpretations of the
3828 -- name for subsequent overload resolution. We optimize a bit here to
3829 -- do this only if we have an overloadable entity that is not on its
3830 -- own on the homonym chain.
3832 elsif Is_Overloadable (E)
3833 and then (Present (Homonym (E)) or else Current_Entity (N) /= E)
3835 Collect_Interps (N);
3837 -- If no homonyms were visible, the entity is unambiguous
3839 if not Is_Overloaded (N) then
3840 Generate_Reference (E, N);
3843 -- Case of non-overloadable entity, set the entity providing that
3844 -- we do not have the case of a discriminant reference within a
3845 -- default expression. Such references are replaced with the
3846 -- corresponding discriminal, which is the formal corresponding to
3847 -- to the discriminant in the initialization procedure.
3850 -- Entity is unambiguous, indicate that it is referenced here. One
3851 -- slightly odd case is that we do not want to set the Referenced
3852 -- flag if the entity is a label, and the identifier is the label
3853 -- in the source, since this is not a reference from the point of
3856 if Nkind (Parent (N)) = N_Label then
3858 R : constant Boolean := Referenced (E);
3861 Generate_Reference (E, N);
3862 Set_Referenced (E, R);
3865 -- Normal case, not a label: generate reference
3867 -- ??? It is too early to generate a reference here even if
3868 -- the entity is unambiguous, because the tree is not
3869 -- sufficiently typed at this point for Generate_Reference to
3870 -- determine whether this reference modifies the denoted object
3871 -- (because implicit derefences cannot be identified prior to
3872 -- full type resolution).
3875 Generate_Reference (E, N);
3876 Check_Nested_Access (E);
3879 -- Set Entity, with style check if need be. For a discriminant
3880 -- reference, replace by the corresponding discriminal, i.e. the
3881 -- parameter of the initialization procedure that corresponds to
3882 -- the discriminant. If this replacement is being performed, there
3883 -- is no style check to perform.
3885 -- This replacement must not be done if we are currently
3886 -- processing a generic spec or body, because the discriminal
3887 -- has not been not generated in this case.
3889 if not In_Default_Expression
3890 or else Ekind (E) /= E_Discriminant
3891 or else Inside_A_Generic
3893 Set_Entity_With_Style_Check (N, E);
3895 -- The replacement is not done either for a task discriminant that
3896 -- appears in a default expression of an entry parameter. See
3897 -- Expand_Discriminant in exp_ch2 for details on their handling.
3899 elsif Is_Concurrent_Type (Scope (E)) then
3906 and then Nkind (P) /= N_Parameter_Specification
3907 and then Nkind (P) /= N_Component_Declaration
3913 and then Nkind (P) = N_Parameter_Specification
3917 Set_Entity (N, Discriminal (E));
3921 -- Otherwise, this is a discriminant in a context in which
3922 -- it is a reference to the corresponding parameter of the
3923 -- init proc for the enclosing type.
3926 Set_Entity (N, Discriminal (E));
3930 end Find_Direct_Name;
3932 ------------------------
3933 -- Find_Expanded_Name --
3934 ------------------------
3936 -- This routine searches the homonym chain of the entity until it finds
3937 -- an entity declared in the scope denoted by the prefix. If the entity
3938 -- is private, it may nevertheless be immediately visible, if we are in
3939 -- the scope of its declaration.
3941 procedure Find_Expanded_Name (N : Node_Id) is
3942 Selector : constant Node_Id := Selector_Name (N);
3943 Candidate : Entity_Id := Empty;
3949 P_Name := Entity (Prefix (N));
3952 -- If the prefix is a renamed package, look for the entity
3953 -- in the original package.
3955 if Ekind (P_Name) = E_Package
3956 and then Present (Renamed_Object (P_Name))
3958 P_Name := Renamed_Object (P_Name);
3960 -- Rewrite node with entity field pointing to renamed object
3962 Rewrite (Prefix (N), New_Copy (Prefix (N)));
3963 Set_Entity (Prefix (N), P_Name);
3965 -- If the prefix is an object of a concurrent type, look for
3966 -- the entity in the associated task or protected type.
3968 elsif Is_Concurrent_Type (Etype (P_Name)) then
3969 P_Name := Etype (P_Name);
3972 Id := Current_Entity (Selector);
3975 Is_New_Candidate : Boolean;
3978 while Present (Id) loop
3979 if Scope (Id) = P_Name then
3981 Is_New_Candidate := True;
3983 -- Ada 2005 (AI-217): Handle shadow entities associated with types
3984 -- declared in limited-withed nested packages. We don't need to
3985 -- handle E_Incomplete_Subtype entities because the entities in
3986 -- the limited view are always E_Incomplete_Type entities (see
3987 -- Build_Limited_Views). Regarding the expression used to evaluate
3988 -- the scope, it is important to note that the limited view also
3989 -- has shadow entities associated nested packages. For this reason
3990 -- the correct scope of the entity is the scope of the real entity
3991 -- The non-limited view may itself be incomplete, in which case
3992 -- get the full view if available.
3994 elsif From_With_Type (Id)
3995 and then Is_Type (Id)
3996 and then Ekind (Id) = E_Incomplete_Type
3997 and then Present (Non_Limited_View (Id))
3998 and then Scope (Non_Limited_View (Id)) = P_Name
4000 Candidate := Get_Full_View (Non_Limited_View (Id));
4001 Is_New_Candidate := True;
4004 Is_New_Candidate := False;
4007 if Is_New_Candidate then
4008 if Is_Child_Unit (Id) then
4009 exit when Is_Visible_Child_Unit (Id)
4010 or else Is_Immediately_Visible (Id);
4013 exit when not Is_Hidden (Id)
4014 or else Is_Immediately_Visible (Id);
4023 and then (Ekind (P_Name) = E_Procedure
4025 Ekind (P_Name) = E_Function)
4026 and then Is_Generic_Instance (P_Name)
4028 -- Expanded name denotes entity in (instance of) generic subprogram.
4029 -- The entity may be in the subprogram instance, or may denote one of
4030 -- the formals, which is declared in the enclosing wrapper package.
4032 P_Name := Scope (P_Name);
4034 Id := Current_Entity (Selector);
4035 while Present (Id) loop
4036 exit when Scope (Id) = P_Name;
4041 if No (Id) or else Chars (Id) /= Chars (Selector) then
4042 Set_Etype (N, Any_Type);
4044 -- If we are looking for an entity defined in System, try to
4045 -- find it in the child package that may have been provided as
4046 -- an extension to System. The Extend_System pragma will have
4047 -- supplied the name of the extension, which may have to be loaded.
4049 if Chars (P_Name) = Name_System
4050 and then Scope (P_Name) = Standard_Standard
4051 and then Present (System_Extend_Unit)
4052 and then Present_System_Aux (N)
4054 Set_Entity (Prefix (N), System_Aux_Id);
4055 Find_Expanded_Name (N);
4058 elsif Nkind (Selector) = N_Operator_Symbol
4059 and then Has_Implicit_Operator (N)
4061 -- There is an implicit instance of the predefined operator in
4062 -- the given scope. The operator entity is defined in Standard.
4063 -- Has_Implicit_Operator makes the node into an Expanded_Name.
4067 elsif Nkind (Selector) = N_Character_Literal
4068 and then Has_Implicit_Character_Literal (N)
4070 -- If there is no literal defined in the scope denoted by the
4071 -- prefix, the literal may belong to (a type derived from)
4072 -- Standard_Character, for which we have no explicit literals.
4077 -- If the prefix is a single concurrent object, use its
4078 -- name in the error message, rather than that of the
4081 if Is_Concurrent_Type (P_Name)
4082 and then Is_Internal_Name (Chars (P_Name))
4084 Error_Msg_Node_2 := Entity (Prefix (N));
4086 Error_Msg_Node_2 := P_Name;
4089 if P_Name = System_Aux_Id then
4090 P_Name := Scope (P_Name);
4091 Set_Entity (Prefix (N), P_Name);
4094 if Present (Candidate) then
4096 -- If we know that the unit is a child unit we can give a more
4097 -- accurate error message.
4099 if Is_Child_Unit (Candidate) then
4101 -- If the candidate is a private child unit and we are in
4102 -- the visible part of a public unit, specialize the error
4103 -- message. There might be a private with_clause for it,
4104 -- but it is not currently active.
4106 if Is_Private_Descendant (Candidate)
4107 and then Ekind (Current_Scope) = E_Package
4108 and then not In_Private_Part (Current_Scope)
4109 and then not Is_Private_Descendant (Current_Scope)
4111 Error_Msg_N ("private child unit& is not visible here",
4114 -- Normal case where we have a missing with for a child unit
4117 Error_Msg_Qual_Level := 99;
4118 Error_Msg_NE ("missing `WITH &;`", Selector, Candidate);
4119 Error_Msg_Qual_Level := 0;
4122 -- Here we don't know that this is a child unit
4125 Error_Msg_NE ("& is not a visible entity of&", N, Selector);
4129 -- Within the instantiation of a child unit, the prefix may
4130 -- denote the parent instance, but the selector has the name
4131 -- of the original child. Find whether we are within the
4132 -- corresponding instance, and get the proper entity, which
4133 -- can only be an enclosing scope.
4136 and then In_Open_Scopes (P_Name)
4137 and then Is_Generic_Instance (P_Name)
4140 S : Entity_Id := Current_Scope;
4144 for J in reverse 0 .. Scope_Stack.Last loop
4145 S := Scope_Stack.Table (J).Entity;
4147 exit when S = Standard_Standard;
4149 if Ekind (S) = E_Function
4150 or else Ekind (S) = E_Package
4151 or else Ekind (S) = E_Procedure
4153 P := Generic_Parent (Specification
4154 (Unit_Declaration_Node (S)));
4157 and then Chars (Scope (P)) = Chars (O_Name)
4158 and then Chars (P) = Chars (Selector)
4169 -- If this is a selection from Ada, System or Interfaces, then
4170 -- we assume a missing with for the corresponding package.
4172 if Is_Known_Unit (N) then
4173 if not Error_Posted (N) then
4174 Error_Msg_Node_2 := Selector;
4175 Error_Msg_N ("missing `WITH &.&;`", Prefix (N));
4178 -- If this is a selection from a dummy package, then suppress
4179 -- the error message, of course the entity is missing if the
4180 -- package is missing!
4182 elsif Sloc (Error_Msg_Node_2) = No_Location then
4185 -- Here we have the case of an undefined component
4188 Error_Msg_NE ("& not declared in&", N, Selector);
4190 -- Check for misspelling of some entity in prefix
4192 Id := First_Entity (P_Name);
4193 Get_Name_String (Chars (Selector));
4196 S : constant String (1 .. Name_Len) :=
4197 Name_Buffer (1 .. Name_Len);
4199 while Present (Id) loop
4200 Get_Name_String (Chars (Id));
4201 if Is_Bad_Spelling_Of
4202 (Name_Buffer (1 .. Name_Len), S)
4203 and then not Is_Internal_Name (Chars (Id))
4206 ("possible misspelling of&", Selector, Id);
4214 -- Specialize the message if this may be an instantiation
4215 -- of a child unit that was not mentioned in the context.
4217 if Nkind (Parent (N)) = N_Package_Instantiation
4218 and then Is_Generic_Instance (Entity (Prefix (N)))
4219 and then Is_Compilation_Unit
4220 (Generic_Parent (Parent (Entity (Prefix (N)))))
4222 Error_Msg_Node_2 := Selector;
4223 Error_Msg_N ("\missing `WITH &.&;`", Prefix (N));
4233 if Comes_From_Source (N)
4234 and then Is_Remote_Access_To_Subprogram_Type (Id)
4235 and then Present (Equivalent_Type (Id))
4237 -- If we are not actually generating distribution code (i.e. the
4238 -- current PCS is the dummy non-distributed version), then the
4239 -- Equivalent_Type will be missing, and Id should be treated as
4240 -- a regular access-to-subprogram type.
4242 Id := Equivalent_Type (Id);
4243 Set_Chars (Selector, Chars (Id));
4246 -- Ada 2005 (AI-50217): Check usage of entities in limited withed units
4248 if Ekind (P_Name) = E_Package
4249 and then From_With_Type (P_Name)
4251 if From_With_Type (Id)
4252 or else Is_Type (Id)
4253 or else Ekind (Id) = E_Package
4258 ("limited withed package can only be used to access "
4259 & " incomplete types",
4264 if Is_Task_Type (P_Name)
4265 and then ((Ekind (Id) = E_Entry
4266 and then Nkind (Parent (N)) /= N_Attribute_Reference)
4268 (Ekind (Id) = E_Entry_Family
4270 Nkind (Parent (Parent (N))) /= N_Attribute_Reference))
4272 -- It is an entry call after all, either to the current task (which
4273 -- will deadlock) or to an enclosing task.
4275 Analyze_Selected_Component (N);
4279 Change_Selected_Component_To_Expanded_Name (N);
4281 -- Do style check and generate reference, but skip both steps if this
4282 -- entity has homonyms, since we may not have the right homonym set yet.
4283 -- The proper homonym will be set during the resolve phase.
4285 if Has_Homonym (Id) then
4288 Set_Entity_With_Style_Check (N, Id);
4289 Generate_Reference (Id, N);
4292 if Is_Type (Id) then
4295 Set_Etype (N, Get_Full_View (Etype (Id)));
4298 -- If the Ekind of the entity is Void, it means that all homonyms are
4299 -- hidden from all visibility (RM 8.3(5,14-20)).
4301 if Ekind (Id) = E_Void then
4302 Premature_Usage (N);
4304 elsif Is_Overloadable (Id)
4305 and then Present (Homonym (Id))
4308 H : Entity_Id := Homonym (Id);
4311 while Present (H) loop
4312 if Scope (H) = Scope (Id)
4315 or else Is_Immediately_Visible (H))
4317 Collect_Interps (N);
4324 -- If an extension of System is present, collect possible explicit
4325 -- overloadings declared in the extension.
4327 if Chars (P_Name) = Name_System
4328 and then Scope (P_Name) = Standard_Standard
4329 and then Present (System_Extend_Unit)
4330 and then Present_System_Aux (N)
4332 H := Current_Entity (Id);
4334 while Present (H) loop
4335 if Scope (H) = System_Aux_Id then
4336 Add_One_Interp (N, H, Etype (H));
4345 if Nkind (Selector_Name (N)) = N_Operator_Symbol
4346 and then Scope (Id) /= Standard_Standard
4348 -- In addition to user-defined operators in the given scope, there
4349 -- may be an implicit instance of the predefined operator. The
4350 -- operator (defined in Standard) is found in Has_Implicit_Operator,
4351 -- and added to the interpretations. Procedure Add_One_Interp will
4352 -- determine which hides which.
4354 if Has_Implicit_Operator (N) then
4358 end Find_Expanded_Name;
4360 -------------------------
4361 -- Find_Renamed_Entity --
4362 -------------------------
4364 function Find_Renamed_Entity
4368 Is_Actual : Boolean := False) return Entity_Id
4371 I1 : Interp_Index := 0; -- Suppress junk warnings
4377 function Enclosing_Instance return Entity_Id;
4378 -- If the renaming determines the entity for the default of a formal
4379 -- subprogram nested within another instance, choose the innermost
4380 -- candidate. This is because if the formal has a box, and we are within
4381 -- an enclosing instance where some candidate interpretations are local
4382 -- to this enclosing instance, we know that the default was properly
4383 -- resolved when analyzing the generic, so we prefer the local
4384 -- candidates to those that are external. This is not always the case
4385 -- but is a reasonable heuristic on the use of nested generics. The
4386 -- proper solution requires a full renaming model.
4388 function Is_Visible_Operation (Op : Entity_Id) return Boolean;
4389 -- If the renamed entity is an implicit operator, check whether it is
4390 -- visible because its operand type is properly visible. This check
4391 -- applies to explicit renamed entities that appear in the source in a
4392 -- renaming declaration or a formal subprogram instance, but not to
4393 -- default generic actuals with a name.
4395 function Report_Overload return Entity_Id;
4396 -- List possible interpretations, and specialize message in the
4397 -- case of a generic actual.
4399 function Within (Inner, Outer : Entity_Id) return Boolean;
4400 -- Determine whether a candidate subprogram is defined within the
4401 -- enclosing instance. If yes, it has precedence over outer candidates.
4403 ------------------------
4404 -- Enclosing_Instance --
4405 ------------------------
4407 function Enclosing_Instance return Entity_Id is
4411 if not Is_Generic_Instance (Current_Scope)
4412 and then not Is_Actual
4417 S := Scope (Current_Scope);
4418 while S /= Standard_Standard loop
4419 if Is_Generic_Instance (S) then
4427 end Enclosing_Instance;
4429 --------------------------
4430 -- Is_Visible_Operation --
4431 --------------------------
4433 function Is_Visible_Operation (Op : Entity_Id) return Boolean is
4439 if Ekind (Op) /= E_Operator
4440 or else Scope (Op) /= Standard_Standard
4441 or else (In_Instance
4444 or else Present (Enclosing_Instance)))
4449 -- For a fixed point type operator, check the resulting type,
4450 -- because it may be a mixed mode integer * fixed operation.
4452 if Present (Next_Formal (First_Formal (New_S)))
4453 and then Is_Fixed_Point_Type (Etype (New_S))
4455 Typ := Etype (New_S);
4457 Typ := Etype (First_Formal (New_S));
4460 Btyp := Base_Type (Typ);
4462 if Nkind (Nam) /= N_Expanded_Name then
4463 return (In_Open_Scopes (Scope (Btyp))
4464 or else Is_Potentially_Use_Visible (Btyp)
4465 or else In_Use (Btyp)
4466 or else In_Use (Scope (Btyp)));
4469 Scop := Entity (Prefix (Nam));
4471 if Ekind (Scop) = E_Package
4472 and then Present (Renamed_Object (Scop))
4474 Scop := Renamed_Object (Scop);
4477 -- Operator is visible if prefix of expanded name denotes
4478 -- scope of type, or else type type is defined in System_Aux
4479 -- and the prefix denotes System.
4481 return Scope (Btyp) = Scop
4482 or else (Scope (Btyp) = System_Aux_Id
4483 and then Scope (Scope (Btyp)) = Scop);
4486 end Is_Visible_Operation;
4492 function Within (Inner, Outer : Entity_Id) return Boolean is
4496 Sc := Scope (Inner);
4497 while Sc /= Standard_Standard loop
4508 ---------------------
4509 -- Report_Overload --
4510 ---------------------
4512 function Report_Overload return Entity_Id is
4516 ("ambiguous actual subprogram&, " &
4517 "possible interpretations:", N, Nam);
4520 ("ambiguous subprogram, " &
4521 "possible interpretations:", N);
4524 List_Interps (Nam, N);
4526 end Report_Overload;
4528 -- Start of processing for Find_Renamed_Entry
4532 Candidate_Renaming := Empty;
4534 if not Is_Overloaded (Nam) then
4535 if Entity_Matches_Spec (Entity (Nam), New_S)
4536 and then Is_Visible_Operation (Entity (Nam))
4538 Old_S := Entity (Nam);
4541 Present (First_Formal (Entity (Nam)))
4542 and then Present (First_Formal (New_S))
4543 and then (Base_Type (Etype (First_Formal (Entity (Nam))))
4544 = Base_Type (Etype (First_Formal (New_S))))
4546 Candidate_Renaming := Entity (Nam);
4550 Get_First_Interp (Nam, Ind, It);
4551 while Present (It.Nam) loop
4552 if Entity_Matches_Spec (It.Nam, New_S)
4553 and then Is_Visible_Operation (It.Nam)
4555 if Old_S /= Any_Id then
4557 -- Note: The call to Disambiguate only happens if a
4558 -- previous interpretation was found, in which case I1
4559 -- has received a value.
4561 It1 := Disambiguate (Nam, I1, Ind, Etype (Old_S));
4563 if It1 = No_Interp then
4564 Inst := Enclosing_Instance;
4566 if Present (Inst) then
4567 if Within (It.Nam, Inst) then
4569 elsif Within (Old_S, Inst) then
4572 return Report_Overload;
4576 return Report_Overload;
4590 Present (First_Formal (It.Nam))
4591 and then Present (First_Formal (New_S))
4592 and then (Base_Type (Etype (First_Formal (It.Nam)))
4593 = Base_Type (Etype (First_Formal (New_S))))
4595 Candidate_Renaming := It.Nam;
4598 Get_Next_Interp (Ind, It);
4601 Set_Entity (Nam, Old_S);
4602 Set_Is_Overloaded (Nam, False);
4606 end Find_Renamed_Entity;
4608 -----------------------------
4609 -- Find_Selected_Component --
4610 -----------------------------
4612 procedure Find_Selected_Component (N : Node_Id) is
4613 P : constant Node_Id := Prefix (N);
4616 -- Entity denoted by prefix
4626 if Nkind (P) = N_Error then
4629 -- If the selector already has an entity, the node has been constructed
4630 -- in the course of expansion, and is known to be valid. Do not verify
4631 -- that it is defined for the type (it may be a private component used
4632 -- in the expansion of record equality).
4634 elsif Present (Entity (Selector_Name (N))) then
4637 or else Etype (N) = Any_Type
4640 Sel_Name : constant Node_Id := Selector_Name (N);
4641 Selector : constant Entity_Id := Entity (Sel_Name);
4645 Set_Etype (Sel_Name, Etype (Selector));
4647 if not Is_Entity_Name (P) then
4651 -- Build an actual subtype except for the first parameter
4652 -- of an init proc, where this actual subtype is by
4653 -- definition incorrect, since the object is uninitialized
4654 -- (and does not even have defined discriminants etc.)
4656 if Is_Entity_Name (P)
4657 and then Ekind (Entity (P)) = E_Function
4659 Nam := New_Copy (P);
4661 if Is_Overloaded (P) then
4662 Save_Interps (P, Nam);
4666 Make_Function_Call (Sloc (P), Name => Nam));
4668 Analyze_Selected_Component (N);
4671 elsif Ekind (Selector) = E_Component
4672 and then (not Is_Entity_Name (P)
4673 or else Chars (Entity (P)) /= Name_uInit)
4676 Build_Actual_Subtype_Of_Component (
4677 Etype (Selector), N);
4682 if No (C_Etype) then
4683 C_Etype := Etype (Selector);
4685 Insert_Action (N, C_Etype);
4686 C_Etype := Defining_Identifier (C_Etype);
4689 Set_Etype (N, C_Etype);
4692 -- If this is the name of an entry or protected operation, and
4693 -- the prefix is an access type, insert an explicit dereference,
4694 -- so that entry calls are treated uniformly.
4696 if Is_Access_Type (Etype (P))
4697 and then Is_Concurrent_Type (Designated_Type (Etype (P)))
4700 New_P : constant Node_Id :=
4701 Make_Explicit_Dereference (Sloc (P),
4702 Prefix => Relocate_Node (P));
4705 Set_Etype (P, Designated_Type (Etype (Prefix (P))));
4709 -- If the selected component appears within a default expression
4710 -- and it has an actual subtype, the pre-analysis has not yet
4711 -- completed its analysis, because Insert_Actions is disabled in
4712 -- that context. Within the init proc of the enclosing type we
4713 -- must complete this analysis, if an actual subtype was created.
4715 elsif Inside_Init_Proc then
4717 Typ : constant Entity_Id := Etype (N);
4718 Decl : constant Node_Id := Declaration_Node (Typ);
4720 if Nkind (Decl) = N_Subtype_Declaration
4721 and then not Analyzed (Decl)
4722 and then Is_List_Member (Decl)
4723 and then No (Parent (Decl))
4726 Insert_Action (N, Decl);
4733 elsif Is_Entity_Name (P) then
4734 P_Name := Entity (P);
4736 -- The prefix may denote an enclosing type which is the completion
4737 -- of an incomplete type declaration.
4739 if Is_Type (P_Name) then
4740 Set_Entity (P, Get_Full_View (P_Name));
4741 Set_Etype (P, Entity (P));
4742 P_Name := Entity (P);
4745 P_Type := Base_Type (Etype (P));
4747 if Debug_Flag_E then
4748 Write_Str ("Found prefix type to be ");
4749 Write_Entity_Info (P_Type, " "); Write_Eol;
4752 -- First check for components of a record object (not the
4753 -- result of a call, which is handled below).
4755 if Is_Appropriate_For_Record (P_Type)
4756 and then not Is_Overloadable (P_Name)
4757 and then not Is_Type (P_Name)
4759 -- Selected component of record. Type checking will validate
4760 -- name of selector.
4761 -- ??? could we rewrite an implicit dereference into an explicit
4764 Analyze_Selected_Component (N);
4766 elsif Is_Appropriate_For_Entry_Prefix (P_Type)
4767 and then not In_Open_Scopes (P_Name)
4768 and then (not Is_Concurrent_Type (Etype (P_Name))
4769 or else not In_Open_Scopes (Etype (P_Name)))
4771 -- Call to protected operation or entry. Type checking is
4772 -- needed on the prefix.
4774 Analyze_Selected_Component (N);
4776 elsif (In_Open_Scopes (P_Name)
4777 and then Ekind (P_Name) /= E_Void
4778 and then not Is_Overloadable (P_Name))
4779 or else (Is_Concurrent_Type (Etype (P_Name))
4780 and then In_Open_Scopes (Etype (P_Name)))
4782 -- Prefix denotes an enclosing loop, block, or task, i.e. an
4783 -- enclosing construct that is not a subprogram or accept.
4785 Find_Expanded_Name (N);
4787 elsif Ekind (P_Name) = E_Package then
4788 Find_Expanded_Name (N);
4790 elsif Is_Overloadable (P_Name) then
4792 -- The subprogram may be a renaming (of an enclosing scope) as
4793 -- in the case of the name of the generic within an instantiation.
4795 if (Ekind (P_Name) = E_Procedure
4796 or else Ekind (P_Name) = E_Function)
4797 and then Present (Alias (P_Name))
4798 and then Is_Generic_Instance (Alias (P_Name))
4800 P_Name := Alias (P_Name);
4803 if Is_Overloaded (P) then
4805 -- The prefix must resolve to a unique enclosing construct
4808 Found : Boolean := False;
4813 Get_First_Interp (P, Ind, It);
4814 while Present (It.Nam) loop
4815 if In_Open_Scopes (It.Nam) then
4818 "prefix must be unique enclosing scope", N);
4819 Set_Entity (N, Any_Id);
4820 Set_Etype (N, Any_Type);
4829 Get_Next_Interp (Ind, It);
4834 if In_Open_Scopes (P_Name) then
4835 Set_Entity (P, P_Name);
4836 Set_Is_Overloaded (P, False);
4837 Find_Expanded_Name (N);
4840 -- If no interpretation as an expanded name is possible, it
4841 -- must be a selected component of a record returned by a
4842 -- function call. Reformat prefix as a function call, the rest
4843 -- is done by type resolution. If the prefix is procedure or
4844 -- entry, as is P.X; this is an error.
4846 if Ekind (P_Name) /= E_Function
4847 and then (not Is_Overloaded (P)
4849 Nkind (Parent (N)) = N_Procedure_Call_Statement)
4851 -- Prefix may mention a package that is hidden by a local
4852 -- declaration: let the user know. Scan the full homonym
4853 -- chain, the candidate package may be anywhere on it.
4855 if Present (Homonym (Current_Entity (P_Name))) then
4857 P_Name := Current_Entity (P_Name);
4859 while Present (P_Name) loop
4860 exit when Ekind (P_Name) = E_Package;
4861 P_Name := Homonym (P_Name);
4864 if Present (P_Name) then
4865 Error_Msg_Sloc := Sloc (Entity (Prefix (N)));
4868 ("package& is hidden by declaration#",
4871 Set_Entity (Prefix (N), P_Name);
4872 Find_Expanded_Name (N);
4875 P_Name := Entity (Prefix (N));
4880 ("invalid prefix in selected component&", N, P_Name);
4881 Change_Selected_Component_To_Expanded_Name (N);
4882 Set_Entity (N, Any_Id);
4883 Set_Etype (N, Any_Type);
4886 Nam := New_Copy (P);
4887 Save_Interps (P, Nam);
4889 Make_Function_Call (Sloc (P), Name => Nam));
4891 Analyze_Selected_Component (N);
4895 -- Remaining cases generate various error messages
4898 -- Format node as expanded name, to avoid cascaded errors
4900 Change_Selected_Component_To_Expanded_Name (N);
4901 Set_Entity (N, Any_Id);
4902 Set_Etype (N, Any_Type);
4904 -- Issue error message, but avoid this if error issued already.
4905 -- Use identifier of prefix if one is available.
4907 if P_Name = Any_Id then
4910 elsif Ekind (P_Name) = E_Void then
4911 Premature_Usage (P);
4913 elsif Nkind (P) /= N_Attribute_Reference then
4915 "invalid prefix in selected component&", P);
4917 if Is_Access_Type (P_Type)
4918 and then Ekind (Designated_Type (P_Type)) = E_Incomplete_Type
4921 ("\dereference must not be of an incomplete type " &
4927 "invalid prefix in selected component", P);
4932 -- If prefix is not the name of an entity, it must be an expression,
4933 -- whose type is appropriate for a record. This is determined by
4936 Analyze_Selected_Component (N);
4938 end Find_Selected_Component;
4944 procedure Find_Type (N : Node_Id) is
4954 elsif Nkind (N) = N_Attribute_Reference then
4956 -- Class attribute. This is not valid in Ada 83 mode, but we do not
4957 -- need to enforce that at this point, since the declaration of the
4958 -- tagged type in the prefix would have been flagged already.
4960 if Attribute_Name (N) = Name_Class then
4961 Check_Restriction (No_Dispatch, N);
4962 Find_Type (Prefix (N));
4964 -- Propagate error from bad prefix
4966 if Etype (Prefix (N)) = Any_Type then
4967 Set_Entity (N, Any_Type);
4968 Set_Etype (N, Any_Type);
4972 T := Base_Type (Entity (Prefix (N)));
4974 -- Case where type is not known to be tagged. Its appearance in
4975 -- the prefix of the 'Class attribute indicates that the full view
4978 if not Is_Tagged_Type (T) then
4979 if Ekind (T) = E_Incomplete_Type then
4981 -- It is legal to denote the class type of an incomplete
4982 -- type. The full type will have to be tagged, of course.
4983 -- In Ada2005 this usage is declared obsolescent, so we
4984 -- warn accordingly.
4986 -- ??? This test is temporarily disabled (always False)
4987 -- because it causes an unwanted warning on GNAT sources
4988 -- (built with -gnatg, which includes Warn_On_Obsolescent_
4989 -- Feature). Once this issue is cleared in the sources, it
4992 if not Is_Tagged_Type (T)
4993 and then Ada_Version >= Ada_05
4994 and then Warn_On_Obsolescent_Feature
4998 ("applying 'Class to an untagged imcomplete type"
4999 & " is an obsolescent feature (RM J.11)", N);
5002 Set_Is_Tagged_Type (T);
5003 Set_Primitive_Operations (T, New_Elmt_List);
5004 Make_Class_Wide_Type (T);
5005 Set_Entity (N, Class_Wide_Type (T));
5006 Set_Etype (N, Class_Wide_Type (T));
5008 elsif Ekind (T) = E_Private_Type
5009 and then not Is_Generic_Type (T)
5010 and then In_Private_Part (Scope (T))
5012 -- The Class attribute can be applied to an untagged private
5013 -- type fulfilled by a tagged type prior to the full type
5014 -- declaration (but only within the parent package's private
5015 -- part). Create the class-wide type now and check that the
5016 -- full type is tagged later during its analysis. Note that
5017 -- we do not mark the private type as tagged, unlike the
5018 -- case of incomplete types, because the type must still
5019 -- appear untagged to outside units.
5021 if No (Class_Wide_Type (T)) then
5022 Make_Class_Wide_Type (T);
5025 Set_Entity (N, Class_Wide_Type (T));
5026 Set_Etype (N, Class_Wide_Type (T));
5029 -- Should we introduce a type Any_Tagged and use Wrong_Type
5030 -- here, it would be a bit more consistent???
5033 ("tagged type required, found}",
5034 Prefix (N), First_Subtype (T));
5035 Set_Entity (N, Any_Type);
5039 -- Case of tagged type
5042 if Is_Concurrent_Type (T) then
5043 if No (Corresponding_Record_Type (Entity (Prefix (N)))) then
5045 -- Previous error. Use current type, which at least
5046 -- provides some operations.
5048 C := Entity (Prefix (N));
5051 C := Class_Wide_Type
5052 (Corresponding_Record_Type (Entity (Prefix (N))));
5056 C := Class_Wide_Type (Entity (Prefix (N)));
5059 Set_Entity_With_Style_Check (N, C);
5060 Generate_Reference (C, N);
5064 -- Base attribute, not allowed in Ada 83
5066 elsif Attribute_Name (N) = Name_Base then
5067 if Ada_Version = Ada_83 and then Comes_From_Source (N) then
5069 ("(Ada 83) Base attribute not allowed in subtype mark", N);
5072 Find_Type (Prefix (N));
5073 Typ := Entity (Prefix (N));
5075 if Ada_Version >= Ada_95
5076 and then not Is_Scalar_Type (Typ)
5077 and then not Is_Generic_Type (Typ)
5080 ("prefix of Base attribute must be scalar type",
5083 elsif Sloc (Typ) = Standard_Location
5084 and then Base_Type (Typ) = Typ
5085 and then Warn_On_Redundant_Constructs
5088 ("?redudant attribute, & is its own base type", N, Typ);
5091 T := Base_Type (Typ);
5093 -- Rewrite attribute reference with type itself (see similar
5094 -- processing in Analyze_Attribute, case Base). Preserve
5095 -- prefix if present, for other legality checks.
5097 if Nkind (Prefix (N)) = N_Expanded_Name then
5099 Make_Expanded_Name (Sloc (N),
5101 Prefix => New_Copy (Prefix (Prefix (N))),
5102 Selector_Name => New_Reference_To (T, Sloc (N))));
5105 Rewrite (N, New_Reference_To (T, Sloc (N)));
5112 elsif Attribute_Name (N) = Name_Stub_Type then
5114 -- This is handled in Analyze_Attribute
5118 -- All other attributes are invalid in a subtype mark
5121 Error_Msg_N ("invalid attribute in subtype mark", N);
5127 if Is_Entity_Name (N) then
5128 T_Name := Entity (N);
5130 Error_Msg_N ("subtype mark required in this context", N);
5131 Set_Etype (N, Any_Type);
5135 if T_Name = Any_Id or else Etype (N) = Any_Type then
5137 -- Undefined id. Make it into a valid type
5139 Set_Entity (N, Any_Type);
5141 elsif not Is_Type (T_Name)
5142 and then T_Name /= Standard_Void_Type
5144 Error_Msg_Sloc := Sloc (T_Name);
5145 Error_Msg_N ("subtype mark required in this context", N);
5146 Error_Msg_NE ("\\found & declared#", N, T_Name);
5147 Set_Entity (N, Any_Type);
5150 -- If the type is an incomplete type created to handle
5151 -- anonymous access components of a record type, then the
5152 -- incomplete type is the visible entity and subsequent
5153 -- references will point to it. Mark the original full
5154 -- type as referenced, to prevent spurious warnings.
5156 if Is_Incomplete_Type (T_Name)
5157 and then Present (Full_View (T_Name))
5158 and then not Comes_From_Source (T_Name)
5160 Set_Referenced (Full_View (T_Name));
5163 T_Name := Get_Full_View (T_Name);
5165 -- Ada 2005 (AI-251, AI-50217): Handle interfaces visible through
5166 -- limited-with clauses
5168 if From_With_Type (T_Name)
5169 and then Ekind (T_Name) in Incomplete_Kind
5170 and then Present (Non_Limited_View (T_Name))
5171 and then Is_Interface (Non_Limited_View (T_Name))
5173 T_Name := Non_Limited_View (T_Name);
5176 if In_Open_Scopes (T_Name) then
5177 if Ekind (Base_Type (T_Name)) = E_Task_Type then
5179 -- In Ada 2005, a task name can be used in an access
5180 -- definition within its own body.
5182 if Ada_Version >= Ada_05
5183 and then Nkind (Parent (N)) = N_Access_Definition
5185 Set_Entity (N, T_Name);
5186 Set_Etype (N, T_Name);
5191 ("task type cannot be used as type mark " &
5192 "within its own spec or body", N);
5195 elsif Ekind (Base_Type (T_Name)) = E_Protected_Type then
5197 -- In Ada 2005, a protected name can be used in an access
5198 -- definition within its own body.
5200 if Ada_Version >= Ada_05
5201 and then Nkind (Parent (N)) = N_Access_Definition
5203 Set_Entity (N, T_Name);
5204 Set_Etype (N, T_Name);
5209 ("protected type cannot be used as type mark " &
5210 "within its own spec or body", N);
5214 Error_Msg_N ("type declaration cannot refer to itself", N);
5217 Set_Etype (N, Any_Type);
5218 Set_Entity (N, Any_Type);
5219 Set_Error_Posted (T_Name);
5223 Set_Entity (N, T_Name);
5224 Set_Etype (N, T_Name);
5228 if Present (Etype (N)) and then Comes_From_Source (N) then
5229 if Is_Fixed_Point_Type (Etype (N)) then
5230 Check_Restriction (No_Fixed_Point, N);
5231 elsif Is_Floating_Point_Type (Etype (N)) then
5232 Check_Restriction (No_Floating_Point, N);
5237 ------------------------------------
5238 -- Has_Implicit_Character_Literal --
5239 ------------------------------------
5241 function Has_Implicit_Character_Literal (N : Node_Id) return Boolean is
5243 Found : Boolean := False;
5244 P : constant Entity_Id := Entity (Prefix (N));
5245 Priv_Id : Entity_Id := Empty;
5248 if Ekind (P) = E_Package
5249 and then not In_Open_Scopes (P)
5251 Priv_Id := First_Private_Entity (P);
5254 if P = Standard_Standard then
5255 Change_Selected_Component_To_Expanded_Name (N);
5256 Rewrite (N, Selector_Name (N));
5258 Set_Etype (Original_Node (N), Standard_Character);
5262 Id := First_Entity (P);
5265 and then Id /= Priv_Id
5267 if Is_Character_Type (Id)
5268 and then (Root_Type (Id) = Standard_Character
5269 or else Root_Type (Id) = Standard_Wide_Character
5270 or else Root_Type (Id) = Standard_Wide_Wide_Character)
5271 and then Id = Base_Type (Id)
5273 -- We replace the node with the literal itself, resolve as a
5274 -- character, and set the type correctly.
5277 Change_Selected_Component_To_Expanded_Name (N);
5278 Rewrite (N, Selector_Name (N));
5281 Set_Etype (Original_Node (N), Id);
5285 -- More than one type derived from Character in given scope.
5286 -- Collect all possible interpretations.
5288 Add_One_Interp (N, Id, Id);
5296 end Has_Implicit_Character_Literal;
5298 ----------------------
5299 -- Has_Private_With --
5300 ----------------------
5302 function Has_Private_With (E : Entity_Id) return Boolean is
5303 Comp_Unit : constant Node_Id := Cunit (Current_Sem_Unit);
5307 Item := First (Context_Items (Comp_Unit));
5308 while Present (Item) loop
5309 if Nkind (Item) = N_With_Clause
5310 and then Private_Present (Item)
5311 and then Entity (Name (Item)) = E
5320 end Has_Private_With;
5322 ---------------------------
5323 -- Has_Implicit_Operator --
5324 ---------------------------
5326 function Has_Implicit_Operator (N : Node_Id) return Boolean is
5327 Op_Id : constant Name_Id := Chars (Selector_Name (N));
5328 P : constant Entity_Id := Entity (Prefix (N));
5330 Priv_Id : Entity_Id := Empty;
5332 procedure Add_Implicit_Operator
5334 Op_Type : Entity_Id := Empty);
5335 -- Add implicit interpretation to node N, using the type for which a
5336 -- predefined operator exists. If the operator yields a boolean type,
5337 -- the Operand_Type is implicitly referenced by the operator, and a
5338 -- reference to it must be generated.
5340 ---------------------------
5341 -- Add_Implicit_Operator --
5342 ---------------------------
5344 procedure Add_Implicit_Operator
5346 Op_Type : Entity_Id := Empty)
5348 Predef_Op : Entity_Id;
5351 Predef_Op := Current_Entity (Selector_Name (N));
5353 while Present (Predef_Op)
5354 and then Scope (Predef_Op) /= Standard_Standard
5356 Predef_Op := Homonym (Predef_Op);
5359 if Nkind (N) = N_Selected_Component then
5360 Change_Selected_Component_To_Expanded_Name (N);
5363 Add_One_Interp (N, Predef_Op, T);
5365 -- For operators with unary and binary interpretations, add both
5367 if Present (Homonym (Predef_Op)) then
5368 Add_One_Interp (N, Homonym (Predef_Op), T);
5371 -- The node is a reference to a predefined operator, and
5372 -- an implicit reference to the type of its operands.
5374 if Present (Op_Type) then
5375 Generate_Operator_Reference (N, Op_Type);
5377 Generate_Operator_Reference (N, T);
5379 end Add_Implicit_Operator;
5381 -- Start of processing for Has_Implicit_Operator
5384 if Ekind (P) = E_Package
5385 and then not In_Open_Scopes (P)
5387 Priv_Id := First_Private_Entity (P);
5390 Id := First_Entity (P);
5394 -- Boolean operators: an implicit declaration exists if the scope
5395 -- contains a declaration for a derived Boolean type, or for an
5396 -- array of Boolean type.
5398 when Name_Op_And | Name_Op_Not | Name_Op_Or | Name_Op_Xor =>
5399 while Id /= Priv_Id loop
5400 if Valid_Boolean_Arg (Id)
5401 and then Id = Base_Type (Id)
5403 Add_Implicit_Operator (Id);
5410 -- Equality: look for any non-limited type (result is Boolean)
5412 when Name_Op_Eq | Name_Op_Ne =>
5413 while Id /= Priv_Id loop
5415 and then not Is_Limited_Type (Id)
5416 and then Id = Base_Type (Id)
5418 Add_Implicit_Operator (Standard_Boolean, Id);
5425 -- Comparison operators: scalar type, or array of scalar
5427 when Name_Op_Lt | Name_Op_Le | Name_Op_Gt | Name_Op_Ge =>
5428 while Id /= Priv_Id loop
5429 if (Is_Scalar_Type (Id)
5430 or else (Is_Array_Type (Id)
5431 and then Is_Scalar_Type (Component_Type (Id))))
5432 and then Id = Base_Type (Id)
5434 Add_Implicit_Operator (Standard_Boolean, Id);
5441 -- Arithmetic operators: any numeric type
5451 while Id /= Priv_Id loop
5452 if Is_Numeric_Type (Id)
5453 and then Id = Base_Type (Id)
5455 Add_Implicit_Operator (Id);
5462 -- Concatenation: any one-dimensional array type
5464 when Name_Op_Concat =>
5465 while Id /= Priv_Id loop
5466 if Is_Array_Type (Id) and then Number_Dimensions (Id) = 1
5467 and then Id = Base_Type (Id)
5469 Add_Implicit_Operator (Id);
5476 -- What is the others condition here? Should we be using a
5477 -- subtype of Name_Id that would restrict to operators ???
5479 when others => null;
5482 -- If we fall through, then we do not have an implicit operator
5486 end Has_Implicit_Operator;
5488 --------------------
5489 -- In_Open_Scopes --
5490 --------------------
5492 function In_Open_Scopes (S : Entity_Id) return Boolean is
5494 -- Several scope stacks are maintained by Scope_Stack. The base of the
5495 -- currently active scope stack is denoted by the Is_Active_Stack_Base
5496 -- flag in the scope stack entry. Note that the scope stacks used to
5497 -- simply be delimited implicitly by the presence of Standard_Standard
5498 -- at their base, but there now are cases where this is not sufficient
5499 -- because Standard_Standard actually may appear in the middle of the
5500 -- active set of scopes.
5502 for J in reverse 0 .. Scope_Stack.Last loop
5503 if Scope_Stack.Table (J).Entity = S then
5507 -- Check Is_Active_Stack_Base to tell us when to stop, as there are
5508 -- cases where Standard_Standard appears in the middle of the active
5509 -- set of scopes. This affects the declaration and overriding of
5510 -- private inherited operations in instantiations of generic child
5513 exit when Scope_Stack.Table (J).Is_Active_Stack_Base;
5519 -----------------------------
5520 -- Inherit_Renamed_Profile --
5521 -----------------------------
5523 procedure Inherit_Renamed_Profile (New_S : Entity_Id; Old_S : Entity_Id) is
5530 if Ekind (Old_S) = E_Operator then
5531 New_F := First_Formal (New_S);
5533 while Present (New_F) loop
5534 Set_Etype (New_F, Base_Type (Etype (New_F)));
5535 Next_Formal (New_F);
5538 Set_Etype (New_S, Base_Type (Etype (New_S)));
5541 New_F := First_Formal (New_S);
5542 Old_F := First_Formal (Old_S);
5544 while Present (New_F) loop
5545 New_T := Etype (New_F);
5546 Old_T := Etype (Old_F);
5548 -- If the new type is a renaming of the old one, as is the
5549 -- case for actuals in instances, retain its name, to simplify
5550 -- later disambiguation.
5552 if Nkind (Parent (New_T)) = N_Subtype_Declaration
5553 and then Is_Entity_Name (Subtype_Indication (Parent (New_T)))
5554 and then Entity (Subtype_Indication (Parent (New_T))) = Old_T
5558 Set_Etype (New_F, Old_T);
5561 Next_Formal (New_F);
5562 Next_Formal (Old_F);
5565 if Ekind (Old_S) = E_Function
5566 or else Ekind (Old_S) = E_Enumeration_Literal
5568 Set_Etype (New_S, Etype (Old_S));
5571 end Inherit_Renamed_Profile;
5577 procedure Initialize is
5582 -------------------------
5583 -- Install_Use_Clauses --
5584 -------------------------
5586 procedure Install_Use_Clauses
5588 Force_Installation : Boolean := False)
5596 while Present (U) loop
5598 -- Case of USE package
5600 if Nkind (U) = N_Use_Package_Clause then
5601 P := First (Names (U));
5602 while Present (P) loop
5605 if Ekind (Id) = E_Package then
5607 Note_Redundant_Use (P);
5609 elsif Present (Renamed_Object (Id))
5610 and then In_Use (Renamed_Object (Id))
5612 Note_Redundant_Use (P);
5614 elsif Force_Installation or else Applicable_Use (P) then
5615 Use_One_Package (Id, U);
5626 P := First (Subtype_Marks (U));
5627 while Present (P) loop
5628 if not Is_Entity_Name (P)
5629 or else No (Entity (P))
5633 elsif Entity (P) /= Any_Type then
5641 Next_Use_Clause (U);
5643 end Install_Use_Clauses;
5645 -------------------------------------
5646 -- Is_Appropriate_For_Entry_Prefix --
5647 -------------------------------------
5649 function Is_Appropriate_For_Entry_Prefix (T : Entity_Id) return Boolean is
5650 P_Type : Entity_Id := T;
5653 if Is_Access_Type (P_Type) then
5654 P_Type := Designated_Type (P_Type);
5657 return Is_Task_Type (P_Type) or else Is_Protected_Type (P_Type);
5658 end Is_Appropriate_For_Entry_Prefix;
5660 -------------------------------
5661 -- Is_Appropriate_For_Record --
5662 -------------------------------
5664 function Is_Appropriate_For_Record (T : Entity_Id) return Boolean is
5666 function Has_Components (T1 : Entity_Id) return Boolean;
5667 -- Determine if given type has components (i.e. is either a record
5668 -- type or a type that has discriminants).
5670 --------------------
5671 -- Has_Components --
5672 --------------------
5674 function Has_Components (T1 : Entity_Id) return Boolean is
5676 return Is_Record_Type (T1)
5677 or else (Is_Private_Type (T1) and then Has_Discriminants (T1))
5678 or else (Is_Task_Type (T1) and then Has_Discriminants (T1))
5679 or else (Is_Incomplete_Type (T1)
5680 and then From_With_Type (T1)
5681 and then Present (Non_Limited_View (T1))
5682 and then Is_Record_Type
5683 (Get_Full_View (Non_Limited_View (T1))));
5686 -- Start of processing for Is_Appropriate_For_Record
5691 and then (Has_Components (T)
5692 or else (Is_Access_Type (T)
5693 and then Has_Components (Designated_Type (T))));
5694 end Is_Appropriate_For_Record;
5696 ------------------------
5697 -- Note_Redundant_Use --
5698 ------------------------
5700 procedure Note_Redundant_Use (Clause : Node_Id) is
5701 Pack_Name : constant Entity_Id := Entity (Clause);
5702 Cur_Use : constant Node_Id := Current_Use_Clause (Pack_Name);
5703 Decl : constant Node_Id := Parent (Clause);
5705 Prev_Use : Node_Id := Empty;
5706 Redundant : Node_Id := Empty;
5707 -- The Use_Clause which is actually redundant. In the simplest case
5708 -- it is Pack itself, but when we compile a body we install its
5709 -- context before that of its spec, in which case it is the use_clause
5710 -- in the spec that will appear to be redundant, and we want the
5711 -- warning to be placed on the body. Similar complications appear when
5712 -- the redundancy is between a child unit and one of its ancestors.
5715 Set_Redundant_Use (Clause, True);
5717 if not Comes_From_Source (Clause)
5719 or else not Warn_On_Redundant_Constructs
5724 if not Is_Compilation_Unit (Current_Scope) then
5726 -- If the use_clause is in an inner scope, it is made redundant
5727 -- by some clause in the current context, with one exception:
5728 -- If we're compiling a nested package body, and the use_clause
5729 -- comes from the corresponding spec, the clause is not necessarily
5730 -- fully redundant, so we should not warn. If a warning was
5731 -- warranted, it would have been given when the spec was processed.
5733 if Nkind (Parent (Decl)) = N_Package_Specification then
5735 Package_Spec_Entity : constant Entity_Id :=
5736 Defining_Unit_Name (Parent (Decl));
5738 if In_Package_Body (Package_Spec_Entity) then
5744 Redundant := Clause;
5745 Prev_Use := Cur_Use;
5747 elsif Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Body then
5749 Cur_Unit : constant Unit_Number_Type := Get_Source_Unit (Cur_Use);
5750 New_Unit : constant Unit_Number_Type := Get_Source_Unit (Clause);
5754 if Cur_Unit = New_Unit then
5756 -- Redundant clause in same body
5758 Redundant := Clause;
5759 Prev_Use := Cur_Use;
5761 elsif Cur_Unit = Current_Sem_Unit then
5763 -- If the new clause is not in the current unit it has been
5764 -- analyzed first, and it makes the other one redundant.
5765 -- However, if the new clause appears in a subunit, Cur_Unit
5766 -- is still the parent, and in that case the redundant one
5767 -- is the one appearing in the subunit.
5769 if Nkind (Unit (Cunit (New_Unit))) = N_Subunit then
5770 Redundant := Clause;
5771 Prev_Use := Cur_Use;
5773 -- Most common case: redundant clause in body,
5774 -- original clause in spec. Current scope is spec entity.
5779 Unit (Library_Unit (Cunit (Current_Sem_Unit))))
5781 Redundant := Cur_Use;
5785 -- The new clause may appear in an unrelated unit, when
5786 -- the parents of a generic are being installed prior to
5787 -- instantiation. In this case there must be no warning.
5788 -- We detect this case by checking whether the current top
5789 -- of the stack is related to the current compilation.
5791 Scop := Current_Scope;
5792 while Present (Scop)
5793 and then Scop /= Standard_Standard
5795 if Is_Compilation_Unit (Scop)
5796 and then not Is_Child_Unit (Scop)
5800 elsif Scop = Cunit_Entity (Current_Sem_Unit) then
5804 Scop := Scope (Scop);
5807 Redundant := Cur_Use;
5811 elsif New_Unit = Current_Sem_Unit then
5812 Redundant := Clause;
5813 Prev_Use := Cur_Use;
5816 -- Neither is the current unit, so they appear in parent or
5817 -- sibling units. Warning will be emitted elsewhere.
5823 elsif Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Declaration
5824 and then Present (Parent_Spec (Unit (Cunit (Current_Sem_Unit))))
5826 -- Use_clause is in child unit of current unit, and the child
5827 -- unit appears in the context of the body of the parent, so it
5828 -- has been installed first, even though it is the redundant one.
5829 -- Depending on their placement in the context, the visible or the
5830 -- private parts of the two units, either might appear as redundant,
5831 -- but the message has to be on the current unit.
5833 if Get_Source_Unit (Cur_Use) = Current_Sem_Unit then
5834 Redundant := Cur_Use;
5837 Redundant := Clause;
5838 Prev_Use := Cur_Use;
5841 -- If the new use clause appears in the private part of a parent unit
5842 -- it may appear to be redudant w.r.t. a use clause in a child unit,
5843 -- but the previous use clause was needed in the visible part of the
5844 -- child, and no warning should be emitted.
5846 if Nkind (Parent (Decl)) = N_Package_Specification
5848 List_Containing (Decl) = Private_Declarations (Parent (Decl))
5851 Par : constant Entity_Id := Defining_Entity (Parent (Decl));
5852 Spec : constant Node_Id :=
5853 Specification (Unit (Cunit (Current_Sem_Unit)));
5856 if Is_Compilation_Unit (Par)
5857 and then Par /= Cunit_Entity (Current_Sem_Unit)
5858 and then Parent (Cur_Use) = Spec
5860 List_Containing (Cur_Use) = Visible_Declarations (Spec)
5871 if Present (Redundant) then
5872 Error_Msg_Sloc := Sloc (Prev_Use);
5874 ("& is already use-visible through previous use clause #?",
5875 Redundant, Pack_Name);
5877 end Note_Redundant_Use;
5883 procedure Pop_Scope is
5884 SST : Scope_Stack_Entry renames Scope_Stack.Table (Scope_Stack.Last);
5887 if Debug_Flag_E then
5891 Scope_Suppress := SST.Save_Scope_Suppress;
5892 Local_Suppress_Stack_Top := SST.Save_Local_Suppress_Stack_Top;
5894 if Debug_Flag_W then
5895 Write_Str ("--> exiting scope: ");
5896 Write_Name (Chars (Current_Scope));
5897 Write_Str (", Depth=");
5898 Write_Int (Int (Scope_Stack.Last));
5902 End_Use_Clauses (SST.First_Use_Clause);
5904 -- If the actions to be wrapped are still there they will get lost
5905 -- causing incomplete code to be generated. It is better to abort in
5906 -- this case (and we do the abort even with assertions off since the
5907 -- penalty is incorrect code generation)
5909 if SST.Actions_To_Be_Wrapped_Before /= No_List
5911 SST.Actions_To_Be_Wrapped_After /= No_List
5916 -- Free last subprogram name if allocated, and pop scope
5918 Free (SST.Last_Subprogram_Name);
5919 Scope_Stack.Decrement_Last;
5926 procedure Push_Scope (S : Entity_Id) is
5930 if Ekind (S) = E_Void then
5933 -- Set scope depth if not a non-concurrent type, and we have not
5934 -- yet set the scope depth. This means that we have the first
5935 -- occurrence of the scope, and this is where the depth is set.
5937 elsif (not Is_Type (S) or else Is_Concurrent_Type (S))
5938 and then not Scope_Depth_Set (S)
5940 if S = Standard_Standard then
5941 Set_Scope_Depth_Value (S, Uint_0);
5943 elsif Is_Child_Unit (S) then
5944 Set_Scope_Depth_Value (S, Uint_1);
5946 elsif not Is_Record_Type (Current_Scope) then
5947 if Ekind (S) = E_Loop then
5948 Set_Scope_Depth_Value (S, Scope_Depth (Current_Scope));
5950 Set_Scope_Depth_Value (S, Scope_Depth (Current_Scope) + 1);
5955 Scope_Stack.Increment_Last;
5958 SST : Scope_Stack_Entry renames Scope_Stack.Table (Scope_Stack.Last);
5962 SST.Save_Scope_Suppress := Scope_Suppress;
5963 SST.Save_Local_Suppress_Stack_Top := Local_Suppress_Stack_Top;
5965 if Scope_Stack.Last > Scope_Stack.First then
5966 SST.Component_Alignment_Default := Scope_Stack.Table
5967 (Scope_Stack.Last - 1).
5968 Component_Alignment_Default;
5971 SST.Last_Subprogram_Name := null;
5972 SST.Is_Transient := False;
5973 SST.Node_To_Be_Wrapped := Empty;
5974 SST.Pending_Freeze_Actions := No_List;
5975 SST.Actions_To_Be_Wrapped_Before := No_List;
5976 SST.Actions_To_Be_Wrapped_After := No_List;
5977 SST.First_Use_Clause := Empty;
5978 SST.Is_Active_Stack_Base := False;
5979 SST.Previous_Visibility := False;
5982 if Debug_Flag_W then
5983 Write_Str ("--> new scope: ");
5984 Write_Name (Chars (Current_Scope));
5985 Write_Str (", Id=");
5986 Write_Int (Int (Current_Scope));
5987 Write_Str (", Depth=");
5988 Write_Int (Int (Scope_Stack.Last));
5992 -- Deal with copying flags from the previous scope to this one. This
5993 -- is not necessary if either scope is standard, or if the new scope
5996 if S /= Standard_Standard
5997 and then Scope (S) /= Standard_Standard
5998 and then not Is_Child_Unit (S)
6002 if Nkind (E) not in N_Entity then
6006 -- Copy categorization flags from Scope (S) to S, this is not done
6007 -- when Scope (S) is Standard_Standard since propagation is from
6008 -- library unit entity inwards. Copy other relevant attributes as
6009 -- well (Discard_Names in particular).
6011 -- We only propagate inwards for library level entities,
6012 -- inner level subprograms do not inherit the categorization.
6014 if Is_Library_Level_Entity (S) then
6015 Set_Is_Preelaborated (S, Is_Preelaborated (E));
6016 Set_Is_Shared_Passive (S, Is_Shared_Passive (E));
6017 Set_Discard_Names (S, Discard_Names (E));
6018 Set_Suppress_Value_Tracking_On_Call
6019 (S, Suppress_Value_Tracking_On_Call (E));
6020 Set_Categorization_From_Scope (E => S, Scop => E);
6025 ---------------------
6026 -- Premature_Usage --
6027 ---------------------
6029 procedure Premature_Usage (N : Node_Id) is
6030 Kind : constant Node_Kind := Nkind (Parent (Entity (N)));
6031 E : Entity_Id := Entity (N);
6034 -- Within an instance, the analysis of the actual for a formal object
6035 -- does not see the name of the object itself. This is significant only
6036 -- if the object is an aggregate, where its analysis does not do any
6037 -- name resolution on component associations. (see 4717-008). In such a
6038 -- case, look for the visible homonym on the chain.
6041 and then Present (Homonym (E))
6046 and then not In_Open_Scopes (Scope (E))
6053 Set_Etype (N, Etype (E));
6058 if Kind = N_Component_Declaration then
6060 ("component&! cannot be used before end of record declaration", N);
6062 elsif Kind = N_Parameter_Specification then
6064 ("formal parameter&! cannot be used before end of specification",
6067 elsif Kind = N_Discriminant_Specification then
6069 ("discriminant&! cannot be used before end of discriminant part",
6072 elsif Kind = N_Procedure_Specification
6073 or else Kind = N_Function_Specification
6076 ("subprogram&! cannot be used before end of its declaration",
6080 ("object& cannot be used before end of its declaration!", N);
6082 end Premature_Usage;
6084 ------------------------
6085 -- Present_System_Aux --
6086 ------------------------
6088 function Present_System_Aux (N : Node_Id := Empty) return Boolean is
6090 Aux_Name : Unit_Name_Type;
6091 Unum : Unit_Number_Type;
6096 function Find_System (C_Unit : Node_Id) return Entity_Id;
6097 -- Scan context clause of compilation unit to find with_clause
6104 function Find_System (C_Unit : Node_Id) return Entity_Id is
6105 With_Clause : Node_Id;
6108 With_Clause := First (Context_Items (C_Unit));
6109 while Present (With_Clause) loop
6110 if (Nkind (With_Clause) = N_With_Clause
6111 and then Chars (Name (With_Clause)) = Name_System)
6112 and then Comes_From_Source (With_Clause)
6123 -- Start of processing for Present_System_Aux
6126 -- The child unit may have been loaded and analyzed already
6128 if Present (System_Aux_Id) then
6131 -- If no previous pragma for System.Aux, nothing to load
6133 elsif No (System_Extend_Unit) then
6136 -- Use the unit name given in the pragma to retrieve the unit.
6137 -- Verify that System itself appears in the context clause of the
6138 -- current compilation. If System is not present, an error will
6139 -- have been reported already.
6142 With_Sys := Find_System (Cunit (Current_Sem_Unit));
6144 The_Unit := Unit (Cunit (Current_Sem_Unit));
6147 and then (Nkind (The_Unit) = N_Package_Body
6148 or else (Nkind (The_Unit) = N_Subprogram_Body
6149 and then not Acts_As_Spec (Cunit (Current_Sem_Unit))))
6151 With_Sys := Find_System (Library_Unit (Cunit (Current_Sem_Unit)));
6155 and then Present (N)
6157 -- If we are compiling a subunit, we need to examine its
6158 -- context as well (Current_Sem_Unit is the parent unit);
6160 The_Unit := Parent (N);
6162 while Nkind (The_Unit) /= N_Compilation_Unit loop
6163 The_Unit := Parent (The_Unit);
6166 if Nkind (Unit (The_Unit)) = N_Subunit then
6167 With_Sys := Find_System (The_Unit);
6171 if No (With_Sys) then
6175 Loc := Sloc (With_Sys);
6176 Get_Name_String (Chars (Expression (System_Extend_Unit)));
6177 Name_Buffer (8 .. Name_Len + 7) := Name_Buffer (1 .. Name_Len);
6178 Name_Buffer (1 .. 7) := "system.";
6179 Name_Buffer (Name_Len + 8) := '%';
6180 Name_Buffer (Name_Len + 9) := 's';
6181 Name_Len := Name_Len + 9;
6182 Aux_Name := Name_Find;
6186 (Load_Name => Aux_Name,
6189 Error_Node => With_Sys);
6191 if Unum /= No_Unit then
6192 Semantics (Cunit (Unum));
6194 Defining_Entity (Specification (Unit (Cunit (Unum))));
6197 Make_With_Clause (Loc,
6199 Make_Expanded_Name (Loc,
6200 Chars => Chars (System_Aux_Id),
6201 Prefix => New_Reference_To (Scope (System_Aux_Id), Loc),
6202 Selector_Name => New_Reference_To (System_Aux_Id, Loc)));
6204 Set_Entity (Name (Withn), System_Aux_Id);
6206 Set_Library_Unit (Withn, Cunit (Unum));
6207 Set_Corresponding_Spec (Withn, System_Aux_Id);
6208 Set_First_Name (Withn, True);
6209 Set_Implicit_With (Withn, True);
6211 Insert_After (With_Sys, Withn);
6212 Mark_Rewrite_Insertion (Withn);
6213 Set_Context_Installed (Withn);
6217 -- Here if unit load failed
6220 Error_Msg_Name_1 := Name_System;
6221 Error_Msg_Name_2 := Chars (Expression (System_Extend_Unit));
6223 ("extension package `%.%` does not exist",
6224 Opt.System_Extend_Unit);
6228 end Present_System_Aux;
6230 -------------------------
6231 -- Restore_Scope_Stack --
6232 -------------------------
6234 procedure Restore_Scope_Stack (Handle_Use : Boolean := True) is
6237 Comp_Unit : Node_Id;
6238 In_Child : Boolean := False;
6239 Full_Vis : Boolean := True;
6240 SS_Last : constant Int := Scope_Stack.Last;
6243 -- Restore visibility of previous scope stack, if any
6245 for J in reverse 0 .. Scope_Stack.Last loop
6246 exit when Scope_Stack.Table (J).Entity = Standard_Standard
6247 or else No (Scope_Stack.Table (J).Entity);
6249 S := Scope_Stack.Table (J).Entity;
6251 if not Is_Hidden_Open_Scope (S) then
6253 -- If the parent scope is hidden, its entities are hidden as
6254 -- well, unless the entity is the instantiation currently
6257 if not Is_Hidden_Open_Scope (Scope (S))
6258 or else not Analyzed (Parent (S))
6259 or else Scope (S) = Standard_Standard
6261 Set_Is_Immediately_Visible (S, True);
6264 E := First_Entity (S);
6265 while Present (E) loop
6266 if Is_Child_Unit (E) then
6267 Set_Is_Immediately_Visible (E,
6268 Is_Visible_Child_Unit (E) or else In_Open_Scopes (E));
6270 Set_Is_Immediately_Visible (E, True);
6275 if not Full_Vis then
6276 exit when E = First_Private_Entity (S);
6280 -- The visibility of child units (siblings of current compilation)
6281 -- must be restored in any case. Their declarations may appear
6282 -- after the private part of the parent.
6284 if not Full_Vis then
6285 while Present (E) loop
6286 if Is_Child_Unit (E) then
6287 Set_Is_Immediately_Visible (E,
6288 Is_Visible_Child_Unit (E) or else In_Open_Scopes (E));
6296 if Is_Child_Unit (S)
6297 and not In_Child -- check only for current unit
6301 -- Restore visibility of parents according to whether the child
6302 -- is private and whether we are in its visible part.
6304 Comp_Unit := Parent (Unit_Declaration_Node (S));
6306 if Nkind (Comp_Unit) = N_Compilation_Unit
6307 and then Private_Present (Comp_Unit)
6311 elsif (Ekind (S) = E_Package
6312 or else Ekind (S) = E_Generic_Package)
6313 and then (In_Private_Part (S)
6314 or else In_Package_Body (S))
6318 elsif (Ekind (S) = E_Procedure
6319 or else Ekind (S) = E_Function)
6320 and then Has_Completion (S)
6331 if SS_Last >= Scope_Stack.First
6332 and then Scope_Stack.Table (SS_Last).Entity /= Standard_Standard
6335 Install_Use_Clauses (Scope_Stack.Table (SS_Last).First_Use_Clause);
6337 end Restore_Scope_Stack;
6339 ----------------------
6340 -- Save_Scope_Stack --
6341 ----------------------
6343 procedure Save_Scope_Stack (Handle_Use : Boolean := True) is
6346 SS_Last : constant Int := Scope_Stack.Last;
6349 if SS_Last >= Scope_Stack.First
6350 and then Scope_Stack.Table (SS_Last).Entity /= Standard_Standard
6353 End_Use_Clauses (Scope_Stack.Table (SS_Last).First_Use_Clause);
6356 -- If the call is from within a compilation unit, as when called from
6357 -- Rtsfind, make current entries in scope stack invisible while we
6358 -- analyze the new unit.
6360 for J in reverse 0 .. SS_Last loop
6361 exit when Scope_Stack.Table (J).Entity = Standard_Standard
6362 or else No (Scope_Stack.Table (J).Entity);
6364 S := Scope_Stack.Table (J).Entity;
6365 Set_Is_Immediately_Visible (S, False);
6367 E := First_Entity (S);
6368 while Present (E) loop
6369 Set_Is_Immediately_Visible (E, False);
6375 end Save_Scope_Stack;
6381 procedure Set_Use (L : List_Id) is
6383 Pack_Name : Node_Id;
6390 while Present (Decl) loop
6391 if Nkind (Decl) = N_Use_Package_Clause then
6392 Chain_Use_Clause (Decl);
6394 Pack_Name := First (Names (Decl));
6395 while Present (Pack_Name) loop
6396 Pack := Entity (Pack_Name);
6398 if Ekind (Pack) = E_Package
6399 and then Applicable_Use (Pack_Name)
6401 Use_One_Package (Pack, Decl);
6407 elsif Nkind (Decl) = N_Use_Type_Clause then
6408 Chain_Use_Clause (Decl);
6410 Id := First (Subtype_Marks (Decl));
6411 while Present (Id) loop
6412 if Entity (Id) /= Any_Type then
6425 ---------------------
6426 -- Use_One_Package --
6427 ---------------------
6429 procedure Use_One_Package (P : Entity_Id; N : Node_Id) is
6432 Current_Instance : Entity_Id := Empty;
6434 Private_With_OK : Boolean := False;
6437 if Ekind (P) /= E_Package then
6442 Set_Current_Use_Clause (P, N);
6444 -- Ada 2005 (AI-50217): Check restriction
6446 if From_With_Type (P) then
6447 Error_Msg_N ("limited withed package cannot appear in use clause", N);
6450 -- Find enclosing instance, if any
6453 Current_Instance := Current_Scope;
6454 while not Is_Generic_Instance (Current_Instance) loop
6455 Current_Instance := Scope (Current_Instance);
6458 if No (Hidden_By_Use_Clause (N)) then
6459 Set_Hidden_By_Use_Clause (N, New_Elmt_List);
6463 -- If unit is a package renaming, indicate that the renamed
6464 -- package is also in use (the flags on both entities must
6465 -- remain consistent, and a subsequent use of either of them
6466 -- should be recognized as redundant).
6468 if Present (Renamed_Object (P)) then
6469 Set_In_Use (Renamed_Object (P));
6470 Set_Current_Use_Clause (Renamed_Object (P), N);
6471 Real_P := Renamed_Object (P);
6476 -- Ada 2005 (AI-262): Check the use_clause of a private withed package
6477 -- found in the private part of a package specification
6479 if In_Private_Part (Current_Scope)
6480 and then Has_Private_With (P)
6481 and then Is_Child_Unit (Current_Scope)
6482 and then Is_Child_Unit (P)
6483 and then Is_Ancestor_Package (Scope (Current_Scope), P)
6485 Private_With_OK := True;
6488 -- Loop through entities in one package making them potentially
6491 Id := First_Entity (P);
6493 and then (Id /= First_Private_Entity (P)
6494 or else Private_With_OK) -- Ada 2005 (AI-262)
6496 Prev := Current_Entity (Id);
6497 while Present (Prev) loop
6498 if Is_Immediately_Visible (Prev)
6499 and then (not Is_Overloadable (Prev)
6500 or else not Is_Overloadable (Id)
6501 or else (Type_Conformant (Id, Prev)))
6503 if No (Current_Instance) then
6505 -- Potentially use-visible entity remains hidden
6507 goto Next_Usable_Entity;
6509 -- A use clause within an instance hides outer global entities,
6510 -- which are not used to resolve local entities in the
6511 -- instance. Note that the predefined entities in Standard
6512 -- could not have been hidden in the generic by a use clause,
6513 -- and therefore remain visible. Other compilation units whose
6514 -- entities appear in Standard must be hidden in an instance.
6516 -- To determine whether an entity is external to the instance
6517 -- we compare the scope depth of its scope with that of the
6518 -- current instance. However, a generic actual of a subprogram
6519 -- instance is declared in the wrapper package but will not be
6520 -- hidden by a use-visible entity.
6522 -- If Id is called Standard, the predefined package with the
6523 -- same name is in the homonym chain. It has to be ignored
6524 -- because it has no defined scope (being the only entity in
6525 -- the system with this mandated behavior).
6527 elsif not Is_Hidden (Id)
6528 and then Present (Scope (Prev))
6529 and then not Is_Wrapper_Package (Scope (Prev))
6530 and then Scope_Depth (Scope (Prev)) <
6531 Scope_Depth (Current_Instance)
6532 and then (Scope (Prev) /= Standard_Standard
6533 or else Sloc (Prev) > Standard_Location)
6535 Set_Is_Potentially_Use_Visible (Id);
6536 Set_Is_Immediately_Visible (Prev, False);
6537 Append_Elmt (Prev, Hidden_By_Use_Clause (N));
6540 -- A user-defined operator is not use-visible if the predefined
6541 -- operator for the type is immediately visible, which is the case
6542 -- if the type of the operand is in an open scope. This does not
6543 -- apply to user-defined operators that have operands of different
6544 -- types, because the predefined mixed mode operations (multiply
6545 -- and divide) apply to universal types and do not hide anything.
6547 elsif Ekind (Prev) = E_Operator
6548 and then Operator_Matches_Spec (Prev, Id)
6549 and then In_Open_Scopes
6550 (Scope (Base_Type (Etype (First_Formal (Id)))))
6551 and then (No (Next_Formal (First_Formal (Id)))
6552 or else Etype (First_Formal (Id))
6553 = Etype (Next_Formal (First_Formal (Id)))
6554 or else Chars (Prev) = Name_Op_Expon)
6556 goto Next_Usable_Entity;
6559 Prev := Homonym (Prev);
6562 -- On exit, we know entity is not hidden, unless it is private
6564 if not Is_Hidden (Id)
6565 and then ((not Is_Child_Unit (Id))
6566 or else Is_Visible_Child_Unit (Id))
6568 Set_Is_Potentially_Use_Visible (Id);
6570 if Is_Private_Type (Id)
6571 and then Present (Full_View (Id))
6573 Set_Is_Potentially_Use_Visible (Full_View (Id));
6577 <<Next_Usable_Entity>>
6581 -- Child units are also made use-visible by a use clause, but they may
6582 -- appear after all visible declarations in the parent entity list.
6584 while Present (Id) loop
6585 if Is_Child_Unit (Id)
6586 and then Is_Visible_Child_Unit (Id)
6588 Set_Is_Potentially_Use_Visible (Id);
6594 if Chars (Real_P) = Name_System
6595 and then Scope (Real_P) = Standard_Standard
6596 and then Present_System_Aux (N)
6598 Use_One_Package (System_Aux_Id, N);
6601 end Use_One_Package;
6607 procedure Use_One_Type (Id : Node_Id) is
6609 Is_Known_Used : Boolean;
6613 function Spec_Reloaded_For_Body return Boolean;
6614 -- Determine whether the compilation unit is a package body and the use
6615 -- type clause is in the spec of the same package. Even though the spec
6616 -- was analyzed first, its context is reloaded when analysing the body.
6618 ----------------------------
6619 -- Spec_Reloaded_For_Body --
6620 ----------------------------
6622 function Spec_Reloaded_For_Body return Boolean is
6624 if Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Body then
6626 Spec : constant Node_Id :=
6627 Parent (List_Containing (Parent (Id)));
6630 Nkind (Spec) = N_Package_Specification
6631 and then Corresponding_Body (Parent (Spec)) =
6632 Cunit_Entity (Current_Sem_Unit);
6637 end Spec_Reloaded_For_Body;
6639 -- Start of processing for Use_One_Type;
6642 -- It is the type determined by the subtype mark (8.4(8)) whose
6643 -- operations become potentially use-visible.
6645 T := Base_Type (Entity (Id));
6647 -- Either the type itself is used, the package where it is declared
6648 -- is in use or the entity is declared in the current package, thus
6653 or else In_Use (Scope (T))
6654 or else Scope (T) = Current_Scope;
6656 Set_Redundant_Use (Id,
6657 Is_Known_Used or else Is_Potentially_Use_Visible (T));
6659 if In_Open_Scopes (Scope (T)) then
6662 elsif From_With_Type (T) then
6664 ("incomplete type from limited view "
6665 & "cannot appear in use clause", Id);
6667 -- If the subtype mark designates a subtype in a different package,
6668 -- we have to check that the parent type is visible, otherwise the
6669 -- use type clause is a noop. Not clear how to do that???
6671 elsif not Redundant_Use (Id) then
6673 Op_List := Collect_Primitive_Operations (T);
6675 Elmt := First_Elmt (Op_List);
6676 while Present (Elmt) loop
6677 if (Nkind (Node (Elmt)) = N_Defining_Operator_Symbol
6678 or else Chars (Node (Elmt)) in Any_Operator_Name)
6679 and then not Is_Hidden (Node (Elmt))
6681 Set_Is_Potentially_Use_Visible (Node (Elmt));
6688 -- If warning on redundant constructs, check for unnecessary WITH
6690 if Warn_On_Redundant_Constructs
6691 and then Is_Known_Used
6693 -- with P; with P; use P;
6694 -- package P is package X is package body X is
6695 -- type T ... use P.T;
6697 -- The compilation unit is the body of X. GNAT first compiles the
6698 -- spec of X, then procedes to the body. At that point P is marked
6699 -- as use visible. The analysis then reinstalls the spec along with
6700 -- its context. The use clause P.T is now recognized as redundant,
6701 -- but in the wrong context. Do not emit a warning in such cases.
6703 and then not Spec_Reloaded_For_Body
6705 -- The type already has a use clause
6709 ("& is already use-visible through previous use type clause?",
6712 -- The package where T is declared is already used
6714 elsif In_Use (Scope (T)) then
6715 Error_Msg_Sloc := Sloc (Current_Use_Clause (Scope (T)));
6717 ("& is already use-visible through package use clause #?",
6720 -- The current scope is the package where T is declared
6723 Error_Msg_Node_2 := Scope (T);
6725 ("& is already use-visible inside package &?", Id, Id);
6734 procedure Write_Info is
6735 Id : Entity_Id := First_Entity (Current_Scope);
6738 -- No point in dumping standard entities
6740 if Current_Scope = Standard_Standard then
6744 Write_Str ("========================================================");
6746 Write_Str (" Defined Entities in ");
6747 Write_Name (Chars (Current_Scope));
6749 Write_Str ("========================================================");
6753 Write_Str ("-- none --");
6757 while Present (Id) loop
6758 Write_Entity_Info (Id, " ");
6763 if Scope (Current_Scope) = Standard_Standard then
6765 -- Print information on the current unit itself
6767 Write_Entity_Info (Current_Scope, " ");
6777 procedure Write_Scopes is
6780 for J in reverse 1 .. Scope_Stack.Last loop
6781 S := Scope_Stack.Table (J).Entity;
6782 Write_Int (Int (S));
6783 Write_Str (" === ");
6784 Write_Name (Chars (S));
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