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
2186 Set_Hidden_By_Use_Clause (N, No_Elist);
2188 -- Chain clause to list of use clauses in current scope
2190 if Nkind (Parent (N)) /= N_Compilation_Unit then
2191 Chain_Use_Clause (N);
2194 Id := First (Subtype_Marks (N));
2195 while Present (Id) loop
2198 if Entity (Id) /= Any_Type then
2201 if Nkind (Parent (N)) = N_Compilation_Unit then
2202 if Nkind (Id) = N_Identifier then
2203 Error_Msg_N ("type is not directly visible", Id);
2205 elsif Is_Child_Unit (Scope (Entity (Id)))
2206 and then Scope (Entity (Id)) /= System_Aux_Id
2208 Check_In_Previous_With_Clause (N, Prefix (Id));
2215 end Analyze_Use_Type;
2217 --------------------
2218 -- Applicable_Use --
2219 --------------------
2221 function Applicable_Use (Pack_Name : Node_Id) return Boolean is
2222 Pack : constant Entity_Id := Entity (Pack_Name);
2225 if In_Open_Scopes (Pack) then
2228 elsif In_Use (Pack) then
2229 Note_Redundant_Use (Pack_Name);
2232 elsif Present (Renamed_Object (Pack))
2233 and then In_Use (Renamed_Object (Pack))
2235 Note_Redundant_Use (Pack_Name);
2243 ------------------------
2244 -- Attribute_Renaming --
2245 ------------------------
2247 procedure Attribute_Renaming (N : Node_Id) is
2248 Loc : constant Source_Ptr := Sloc (N);
2249 Nam : constant Node_Id := Name (N);
2250 Spec : constant Node_Id := Specification (N);
2251 New_S : constant Entity_Id := Defining_Unit_Name (Spec);
2252 Aname : constant Name_Id := Attribute_Name (Nam);
2254 Form_Num : Nat := 0;
2255 Expr_List : List_Id := No_List;
2257 Attr_Node : Node_Id;
2258 Body_Node : Node_Id;
2259 Param_Spec : Node_Id;
2262 Generate_Definition (New_S);
2264 -- This procedure is called in the context of subprogram renaming,
2265 -- and thus the attribute must be one that is a subprogram. All of
2266 -- those have at least one formal parameter, with the singular
2267 -- exception of AST_Entry (which is a real oddity, it is odd that
2268 -- this can be renamed at all!)
2270 if not Is_Non_Empty_List (Parameter_Specifications (Spec)) then
2271 if Aname /= Name_AST_Entry then
2273 ("subprogram renaming an attribute must have formals", N);
2278 Param_Spec := First (Parameter_Specifications (Spec));
2279 while Present (Param_Spec) loop
2280 Form_Num := Form_Num + 1;
2282 if Nkind (Parameter_Type (Param_Spec)) /= N_Access_Definition then
2283 Find_Type (Parameter_Type (Param_Spec));
2285 -- The profile of the new entity denotes the base type (s) of
2286 -- the types given in the specification. For access parameters
2287 -- there are no subtypes involved.
2289 Rewrite (Parameter_Type (Param_Spec),
2291 (Base_Type (Entity (Parameter_Type (Param_Spec))), Loc));
2294 if No (Expr_List) then
2295 Expr_List := New_List;
2298 Append_To (Expr_List,
2299 Make_Identifier (Loc,
2300 Chars => Chars (Defining_Identifier (Param_Spec))));
2302 -- The expressions in the attribute reference are not freeze
2303 -- points. Neither is the attribute as a whole, see below.
2305 Set_Must_Not_Freeze (Last (Expr_List));
2310 -- Immediate error if too many formals. Other mismatches in numbers
2311 -- of number of types of parameters are detected when we analyze the
2312 -- body of the subprogram that we construct.
2314 if Form_Num > 2 then
2315 Error_Msg_N ("too many formals for attribute", N);
2317 -- Error if the attribute reference has expressions that look
2318 -- like formal parameters.
2320 elsif Present (Expressions (Nam)) then
2321 Error_Msg_N ("illegal expressions in attribute reference", Nam);
2324 Aname = Name_Compose or else
2325 Aname = Name_Exponent or else
2326 Aname = Name_Leading_Part or else
2327 Aname = Name_Pos or else
2328 Aname = Name_Round or else
2329 Aname = Name_Scaling or else
2332 if Nkind (N) = N_Subprogram_Renaming_Declaration
2333 and then Present (Corresponding_Formal_Spec (N))
2336 ("generic actual cannot be attribute involving universal type",
2340 ("attribute involving a universal type cannot be renamed",
2345 -- AST_Entry is an odd case. It doesn't really make much sense to
2346 -- allow it to be renamed, but that's the DEC rule, so we have to
2347 -- do it right. The point is that the AST_Entry call should be made
2348 -- now, and what the function will return is the returned value.
2350 -- Note that there is no Expr_List in this case anyway
2352 if Aname = Name_AST_Entry then
2358 Ent := Make_Defining_Identifier (Loc, New_Internal_Name ('R'));
2361 Make_Object_Declaration (Loc,
2362 Defining_Identifier => Ent,
2363 Object_Definition =>
2364 New_Occurrence_Of (RTE (RE_AST_Handler), Loc),
2366 Constant_Present => True);
2368 Set_Assignment_OK (Decl, True);
2369 Insert_Action (N, Decl);
2370 Attr_Node := Make_Identifier (Loc, Chars (Ent));
2373 -- For all other attributes, we rewrite the attribute node to have
2374 -- a list of expressions corresponding to the subprogram formals.
2375 -- A renaming declaration is not a freeze point, and the analysis of
2376 -- the attribute reference should not freeze the type of the prefix.
2380 Make_Attribute_Reference (Loc,
2381 Prefix => Prefix (Nam),
2382 Attribute_Name => Aname,
2383 Expressions => Expr_List);
2385 Set_Must_Not_Freeze (Attr_Node);
2386 Set_Must_Not_Freeze (Prefix (Nam));
2389 -- Case of renaming a function
2391 if Nkind (Spec) = N_Function_Specification then
2392 if Is_Procedure_Attribute_Name (Aname) then
2393 Error_Msg_N ("attribute can only be renamed as procedure", Nam);
2397 Find_Type (Result_Definition (Spec));
2398 Rewrite (Result_Definition (Spec),
2400 Base_Type (Entity (Result_Definition (Spec))), Loc));
2403 Make_Subprogram_Body (Loc,
2404 Specification => Spec,
2405 Declarations => New_List,
2406 Handled_Statement_Sequence =>
2407 Make_Handled_Sequence_Of_Statements (Loc,
2408 Statements => New_List (
2409 Make_Simple_Return_Statement (Loc,
2410 Expression => Attr_Node))));
2412 -- Case of renaming a procedure
2415 if not Is_Procedure_Attribute_Name (Aname) then
2416 Error_Msg_N ("attribute can only be renamed as function", Nam);
2421 Make_Subprogram_Body (Loc,
2422 Specification => Spec,
2423 Declarations => New_List,
2424 Handled_Statement_Sequence =>
2425 Make_Handled_Sequence_Of_Statements (Loc,
2426 Statements => New_List (Attr_Node)));
2429 -- In case of tagged types we add the body of the generated function to
2430 -- the freezing actions of the type (because in the general case such
2431 -- type is still not frozen). We exclude from this processing generic
2432 -- formal subprograms found in instantiations and AST_Entry renamings.
2434 if not Present (Corresponding_Formal_Spec (N))
2435 and then Etype (Nam) /= RTE (RE_AST_Handler)
2438 P : constant Entity_Id := Prefix (Nam);
2443 if Is_Tagged_Type (Etype (P)) then
2444 Ensure_Freeze_Node (Etype (P));
2445 Append_Freeze_Action (Etype (P), Body_Node);
2447 Rewrite (N, Body_Node);
2449 Set_Etype (New_S, Base_Type (Etype (New_S)));
2453 -- Generic formal subprograms or AST_Handler renaming
2456 Rewrite (N, Body_Node);
2458 Set_Etype (New_S, Base_Type (Etype (New_S)));
2461 if Is_Compilation_Unit (New_S) then
2463 ("a library unit can only rename another library unit", N);
2466 -- We suppress elaboration warnings for the resulting entity, since
2467 -- clearly they are not needed, and more particularly, in the case
2468 -- of a generic formal subprogram, the resulting entity can appear
2469 -- after the instantiation itself, and thus look like a bogus case
2470 -- of access before elaboration.
2472 Set_Suppress_Elaboration_Warnings (New_S);
2474 end Attribute_Renaming;
2476 ----------------------
2477 -- Chain_Use_Clause --
2478 ----------------------
2480 procedure Chain_Use_Clause (N : Node_Id) is
2482 Level : Int := Scope_Stack.Last;
2485 if not Is_Compilation_Unit (Current_Scope)
2486 or else not Is_Child_Unit (Current_Scope)
2488 null; -- Common case
2490 elsif Defining_Entity (Parent (N)) = Current_Scope then
2491 null; -- Common case for compilation unit
2494 -- If declaration appears in some other scope, it must be in some
2495 -- parent unit when compiling a child.
2497 Pack := Defining_Entity (Parent (N));
2498 if not In_Open_Scopes (Pack) then
2499 null; -- default as well
2502 -- Find entry for parent unit in scope stack
2504 while Scope_Stack.Table (Level).Entity /= Pack loop
2510 Set_Next_Use_Clause (N,
2511 Scope_Stack.Table (Level).First_Use_Clause);
2512 Scope_Stack.Table (Level).First_Use_Clause := N;
2513 end Chain_Use_Clause;
2515 ---------------------------
2516 -- Check_Frozen_Renaming --
2517 ---------------------------
2519 procedure Check_Frozen_Renaming (N : Node_Id; Subp : Entity_Id) is
2525 and then not Has_Completion (Subp)
2529 (Parent (Declaration_Node (Subp)), Defining_Entity (N));
2531 if Is_Entity_Name (Name (N)) then
2532 Old_S := Entity (Name (N));
2534 if not Is_Frozen (Old_S)
2535 and then Operating_Mode /= Check_Semantics
2537 Append_Freeze_Action (Old_S, B_Node);
2539 Insert_After (N, B_Node);
2543 if Is_Intrinsic_Subprogram (Old_S)
2544 and then not In_Instance
2547 ("subprogram used in renaming_as_body cannot be intrinsic",
2552 Insert_After (N, B_Node);
2556 end Check_Frozen_Renaming;
2558 -----------------------------------
2559 -- Check_In_Previous_With_Clause --
2560 -----------------------------------
2562 procedure Check_In_Previous_With_Clause
2566 Pack : constant Entity_Id := Entity (Original_Node (Nam));
2571 Item := First (Context_Items (Parent (N)));
2573 while Present (Item)
2576 if Nkind (Item) = N_With_Clause
2578 -- Protect the frontend against previous critical errors
2580 and then Nkind (Name (Item)) /= N_Selected_Component
2581 and then Entity (Name (Item)) = Pack
2585 -- Find root library unit in with_clause
2587 while Nkind (Par) = N_Expanded_Name loop
2588 Par := Prefix (Par);
2591 if Is_Child_Unit (Entity (Original_Node (Par))) then
2593 ("& is not directly visible", Par, Entity (Par));
2602 -- On exit, package is not mentioned in a previous with_clause.
2603 -- Check if its prefix is.
2605 if Nkind (Nam) = N_Expanded_Name then
2606 Check_In_Previous_With_Clause (N, Prefix (Nam));
2608 elsif Pack /= Any_Id then
2609 Error_Msg_NE ("& is not visible", Nam, Pack);
2611 end Check_In_Previous_With_Clause;
2613 ---------------------------------
2614 -- Check_Library_Unit_Renaming --
2615 ---------------------------------
2617 procedure Check_Library_Unit_Renaming (N : Node_Id; Old_E : Entity_Id) is
2621 if Nkind (Parent (N)) /= N_Compilation_Unit then
2624 -- Check for library unit. Note that we used to check for the scope
2625 -- being Standard here, but that was wrong for Standard itself.
2627 elsif not Is_Compilation_Unit (Old_E)
2628 and then not Is_Child_Unit (Old_E)
2630 Error_Msg_N ("renamed unit must be a library unit", Name (N));
2632 -- Entities defined in Standard (operators and boolean literals) cannot
2633 -- be renamed as library units.
2635 elsif Scope (Old_E) = Standard_Standard
2636 and then Sloc (Old_E) = Standard_Location
2638 Error_Msg_N ("renamed unit must be a library unit", Name (N));
2640 elsif Present (Parent_Spec (N))
2641 and then Nkind (Unit (Parent_Spec (N))) = N_Generic_Package_Declaration
2642 and then not Is_Child_Unit (Old_E)
2645 ("renamed unit must be a child unit of generic parent", Name (N));
2647 elsif Nkind (N) in N_Generic_Renaming_Declaration
2648 and then Nkind (Name (N)) = N_Expanded_Name
2649 and then Is_Generic_Instance (Entity (Prefix (Name (N))))
2650 and then Is_Generic_Unit (Old_E)
2653 ("renamed generic unit must be a library unit", Name (N));
2655 elsif Ekind (Old_E) = E_Package
2656 or else Ekind (Old_E) = E_Generic_Package
2658 -- Inherit categorization flags
2660 New_E := Defining_Entity (N);
2661 Set_Is_Pure (New_E, Is_Pure (Old_E));
2662 Set_Is_Preelaborated (New_E, Is_Preelaborated (Old_E));
2663 Set_Is_Remote_Call_Interface (New_E,
2664 Is_Remote_Call_Interface (Old_E));
2665 Set_Is_Remote_Types (New_E, Is_Remote_Types (Old_E));
2666 Set_Is_Shared_Passive (New_E, Is_Shared_Passive (Old_E));
2668 end Check_Library_Unit_Renaming;
2674 procedure End_Scope is
2680 Id := First_Entity (Current_Scope);
2681 while Present (Id) loop
2682 -- An entity in the current scope is not necessarily the first one
2683 -- on its homonym chain. Find its predecessor if any,
2684 -- If it is an internal entity, it will not be in the visibility
2685 -- chain altogether, and there is nothing to unchain.
2687 if Id /= Current_Entity (Id) then
2688 Prev := Current_Entity (Id);
2689 while Present (Prev)
2690 and then Present (Homonym (Prev))
2691 and then Homonym (Prev) /= Id
2693 Prev := Homonym (Prev);
2696 -- Skip to end of loop if Id is not in the visibility chain
2698 if No (Prev) or else Homonym (Prev) /= Id then
2706 Set_Is_Immediately_Visible (Id, False);
2708 Outer := Homonym (Id);
2709 while Present (Outer) and then Scope (Outer) = Current_Scope loop
2710 Outer := Homonym (Outer);
2713 -- Reset homonym link of other entities, but do not modify link
2714 -- between entities in current scope, so that the back-end can have
2715 -- a proper count of local overloadings.
2718 Set_Name_Entity_Id (Chars (Id), Outer);
2720 elsif Scope (Prev) /= Scope (Id) then
2721 Set_Homonym (Prev, Outer);
2728 -- If the scope generated freeze actions, place them before the
2729 -- current declaration and analyze them. Type declarations and
2730 -- the bodies of initialization procedures can generate such nodes.
2731 -- We follow the parent chain until we reach a list node, which is
2732 -- the enclosing list of declarations. If the list appears within
2733 -- a protected definition, move freeze nodes outside the protected
2737 (Scope_Stack.Table (Scope_Stack.Last).Pending_Freeze_Actions)
2741 L : constant List_Id := Scope_Stack.Table
2742 (Scope_Stack.Last).Pending_Freeze_Actions;
2745 if Is_Itype (Current_Scope) then
2746 Decl := Associated_Node_For_Itype (Current_Scope);
2748 Decl := Parent (Current_Scope);
2753 while not (Is_List_Member (Decl))
2754 or else Nkind (Parent (Decl)) = N_Protected_Definition
2755 or else Nkind (Parent (Decl)) = N_Task_Definition
2757 Decl := Parent (Decl);
2760 Insert_List_Before_And_Analyze (Decl, L);
2769 ---------------------
2770 -- End_Use_Clauses --
2771 ---------------------
2773 procedure End_Use_Clauses (Clause : Node_Id) is
2777 -- Remove Use_Type clauses first, because they affect the
2778 -- visibility of operators in subsequent used packages.
2781 while Present (U) loop
2782 if Nkind (U) = N_Use_Type_Clause then
2786 Next_Use_Clause (U);
2790 while Present (U) loop
2791 if Nkind (U) = N_Use_Package_Clause then
2792 End_Use_Package (U);
2795 Next_Use_Clause (U);
2797 end End_Use_Clauses;
2799 ---------------------
2800 -- End_Use_Package --
2801 ---------------------
2803 procedure End_Use_Package (N : Node_Id) is
2804 Pack_Name : Node_Id;
2809 function Is_Primitive_Operator
2811 F : Entity_Id) return Boolean;
2812 -- Check whether Op is a primitive operator of a use-visible type
2814 ---------------------------
2815 -- Is_Primitive_Operator --
2816 ---------------------------
2818 function Is_Primitive_Operator
2820 F : Entity_Id) return Boolean
2822 T : constant Entity_Id := Etype (F);
2825 and then Scope (T) = Scope (Op);
2826 end Is_Primitive_Operator;
2828 -- Start of processing for End_Use_Package
2831 Pack_Name := First (Names (N));
2832 while Present (Pack_Name) loop
2833 Pack := Entity (Pack_Name);
2835 if Ekind (Pack) = E_Package then
2836 if In_Open_Scopes (Pack) then
2839 elsif not Redundant_Use (Pack_Name) then
2840 Set_In_Use (Pack, False);
2841 Set_Current_Use_Clause (Pack, Empty);
2843 Id := First_Entity (Pack);
2844 while Present (Id) loop
2846 -- Preserve use-visibility of operators that are primitive
2847 -- operators of a type that is use_visible through an active
2850 if Nkind (Id) = N_Defining_Operator_Symbol
2852 (Is_Primitive_Operator (Id, First_Formal (Id))
2854 (Present (Next_Formal (First_Formal (Id)))
2856 Is_Primitive_Operator
2857 (Id, Next_Formal (First_Formal (Id)))))
2862 Set_Is_Potentially_Use_Visible (Id, False);
2865 if Is_Private_Type (Id)
2866 and then Present (Full_View (Id))
2868 Set_Is_Potentially_Use_Visible (Full_View (Id), False);
2874 if Present (Renamed_Object (Pack)) then
2875 Set_In_Use (Renamed_Object (Pack), False);
2876 Set_Current_Use_Clause (Renamed_Object (Pack), Empty);
2879 if Chars (Pack) = Name_System
2880 and then Scope (Pack) = Standard_Standard
2881 and then Present_System_Aux
2883 Id := First_Entity (System_Aux_Id);
2884 while Present (Id) loop
2885 Set_Is_Potentially_Use_Visible (Id, False);
2887 if Is_Private_Type (Id)
2888 and then Present (Full_View (Id))
2890 Set_Is_Potentially_Use_Visible (Full_View (Id), False);
2896 Set_In_Use (System_Aux_Id, False);
2900 Set_Redundant_Use (Pack_Name, False);
2907 if Present (Hidden_By_Use_Clause (N)) then
2908 Elmt := First_Elmt (Hidden_By_Use_Clause (N));
2909 while Present (Elmt) loop
2910 Set_Is_Immediately_Visible (Node (Elmt));
2914 Set_Hidden_By_Use_Clause (N, No_Elist);
2916 end End_Use_Package;
2922 procedure End_Use_Type (N : Node_Id) is
2929 Id := First (Subtype_Marks (N));
2930 while Present (Id) loop
2932 -- A call to rtsfind may occur while analyzing a use_type clause,
2933 -- in which case the type marks are not resolved yet, and there is
2934 -- nothing to remove.
2936 if not Is_Entity_Name (Id)
2937 or else No (Entity (Id))
2945 or else From_With_Type (T)
2949 -- Note that the use_Type clause may mention a subtype of the type
2950 -- whose primitive operations have been made visible. Here as
2951 -- elsewhere, it is the base type that matters for visibility.
2953 elsif In_Open_Scopes (Scope (Base_Type (T))) then
2956 elsif not Redundant_Use (Id) then
2957 Set_In_Use (T, False);
2958 Set_In_Use (Base_Type (T), False);
2959 Op_List := Collect_Primitive_Operations (T);
2961 Elmt := First_Elmt (Op_List);
2962 while Present (Elmt) loop
2963 if Nkind (Node (Elmt)) = N_Defining_Operator_Symbol then
2964 Set_Is_Potentially_Use_Visible (Node (Elmt), False);
2976 ----------------------
2977 -- Find_Direct_Name --
2978 ----------------------
2980 procedure Find_Direct_Name (N : Node_Id) is
2985 Inst : Entity_Id := Empty;
2986 -- Enclosing instance, if any
2988 Homonyms : Entity_Id;
2989 -- Saves start of homonym chain
2991 Nvis_Entity : Boolean;
2992 -- Set True to indicate that at there is at least one entity on the
2993 -- homonym chain which, while not visible, is visible enough from the
2994 -- user point of view to warrant an error message of "not visible"
2995 -- rather than undefined.
2997 Nvis_Is_Private_Subprg : Boolean := False;
2998 -- Ada 2005 (AI-262): Set True to indicate that a form of Beaujolais
2999 -- effect concerning library subprograms has been detected. Used to
3000 -- generate the precise error message.
3002 function From_Actual_Package (E : Entity_Id) return Boolean;
3003 -- Returns true if the entity is declared in a package that is
3004 -- an actual for a formal package of the current instance. Such an
3005 -- entity requires special handling because it may be use-visible
3006 -- but hides directly visible entities defined outside the instance.
3008 function Known_But_Invisible (E : Entity_Id) return Boolean;
3009 -- This function determines whether the entity E (which is not
3010 -- visible) can reasonably be considered to be known to the writer
3011 -- of the reference. This is a heuristic test, used only for the
3012 -- purposes of figuring out whether we prefer to complain that an
3013 -- entity is undefined or invisible (and identify the declaration
3014 -- of the invisible entity in the latter case). The point here is
3015 -- that we don't want to complain that something is invisible and
3016 -- then point to something entirely mysterious to the writer.
3018 procedure Nvis_Messages;
3019 -- Called if there are no visible entries for N, but there is at least
3020 -- one non-directly visible, or hidden declaration. This procedure
3021 -- outputs an appropriate set of error messages.
3023 procedure Undefined (Nvis : Boolean);
3024 -- This function is called if the current node has no corresponding
3025 -- visible entity or entities. The value set in Msg indicates whether
3026 -- an error message was generated (multiple error messages for the
3027 -- same variable are generally suppressed, see body for details).
3028 -- Msg is True if an error message was generated, False if not. This
3029 -- value is used by the caller to determine whether or not to output
3030 -- additional messages where appropriate. The parameter is set False
3031 -- to get the message "X is undefined", and True to get the message
3032 -- "X is not visible".
3034 -------------------------
3035 -- From_Actual_Package --
3036 -------------------------
3038 function From_Actual_Package (E : Entity_Id) return Boolean is
3039 Scop : constant Entity_Id := Scope (E);
3043 if not In_Instance then
3046 Inst := Current_Scope;
3047 while Present (Inst)
3048 and then Ekind (Inst) /= E_Package
3049 and then not Is_Generic_Instance (Inst)
3051 Inst := Scope (Inst);
3058 Act := First_Entity (Inst);
3059 while Present (Act) loop
3060 if Ekind (Act) = E_Package then
3062 -- Check for end of actuals list
3064 if Renamed_Object (Act) = Inst then
3067 elsif Present (Associated_Formal_Package (Act))
3068 and then Renamed_Object (Act) = Scop
3070 -- Entity comes from (instance of) formal package
3085 end From_Actual_Package;
3087 -------------------------
3088 -- Known_But_Invisible --
3089 -------------------------
3091 function Known_But_Invisible (E : Entity_Id) return Boolean is
3092 Fname : File_Name_Type;
3095 -- Entities in Standard are always considered to be known
3097 if Sloc (E) <= Standard_Location then
3100 -- An entity that does not come from source is always considered
3101 -- to be unknown, since it is an artifact of code expansion.
3103 elsif not Comes_From_Source (E) then
3106 -- In gnat internal mode, we consider all entities known
3108 elsif GNAT_Mode then
3112 -- Here we have an entity that is not from package Standard, and
3113 -- which comes from Source. See if it comes from an internal file.
3115 Fname := Unit_File_Name (Get_Source_Unit (E));
3117 -- Case of from internal file
3119 if Is_Internal_File_Name (Fname) then
3121 -- Private part entities in internal files are never considered
3122 -- to be known to the writer of normal application code.
3124 if Is_Hidden (E) then
3128 -- Entities from System packages other than System and
3129 -- System.Storage_Elements are not considered to be known.
3130 -- System.Auxxxx files are also considered known to the user.
3132 -- Should refine this at some point to generally distinguish
3133 -- between known and unknown internal files ???
3135 Get_Name_String (Fname);
3140 Name_Buffer (1 .. 2) /= "s-"
3142 Name_Buffer (3 .. 8) = "stoele"
3144 Name_Buffer (3 .. 5) = "aux";
3146 -- If not an internal file, then entity is definitely known,
3147 -- even if it is in a private part (the message generated will
3148 -- note that it is in a private part)
3153 end Known_But_Invisible;
3159 procedure Nvis_Messages is
3160 Comp_Unit : Node_Id;
3162 Hidden : Boolean := False;
3166 -- Ada 2005 (AI-262): Generate a precise error concerning the
3167 -- Beaujolais effect that was previously detected
3169 if Nvis_Is_Private_Subprg then
3171 pragma Assert (Nkind (E2) = N_Defining_Identifier
3172 and then Ekind (E2) = E_Function
3173 and then Scope (E2) = Standard_Standard
3174 and then Has_Private_With (E2));
3176 -- Find the sloc corresponding to the private with'ed unit
3178 Comp_Unit := Cunit (Current_Sem_Unit);
3179 Error_Msg_Sloc := No_Location;
3181 Item := First (Context_Items (Comp_Unit));
3182 while Present (Item) loop
3183 if Nkind (Item) = N_With_Clause
3184 and then Private_Present (Item)
3185 and then Entity (Name (Item)) = E2
3187 Error_Msg_Sloc := Sloc (Item);
3194 pragma Assert (Error_Msg_Sloc /= No_Location);
3196 Error_Msg_N ("(Ada 2005): hidden by private with clause #", N);
3200 Undefined (Nvis => True);
3204 -- First loop does hidden declarations
3207 while Present (Ent) loop
3208 if Is_Potentially_Use_Visible (Ent) then
3210 Error_Msg_N ("multiple use clauses cause hiding!", N);
3214 Error_Msg_Sloc := Sloc (Ent);
3215 Error_Msg_N ("hidden declaration#!", N);
3218 Ent := Homonym (Ent);
3221 -- If we found hidden declarations, then that's enough, don't
3222 -- bother looking for non-visible declarations as well.
3228 -- Second loop does non-directly visible declarations
3231 while Present (Ent) loop
3232 if not Is_Potentially_Use_Visible (Ent) then
3234 -- Do not bother the user with unknown entities
3236 if not Known_But_Invisible (Ent) then
3240 Error_Msg_Sloc := Sloc (Ent);
3242 -- Output message noting that there is a non-visible
3243 -- declaration, distinguishing the private part case.
3245 if Is_Hidden (Ent) then
3246 Error_Msg_N ("non-visible (private) declaration#!", N);
3248 Error_Msg_N ("non-visible declaration#!", N);
3250 if Is_Compilation_Unit (Ent)
3252 Nkind (Parent (Parent (N))) = N_Use_Package_Clause
3254 Error_Msg_Qual_Level := 99;
3255 Error_Msg_NE ("\\missing `WITH &;`", N, Ent);
3256 Error_Msg_Qual_Level := 0;
3260 -- Set entity and its containing package as referenced. We
3261 -- can't be sure of this, but this seems a better choice
3262 -- to avoid unused entity messages.
3264 if Comes_From_Source (Ent) then
3265 Set_Referenced (Ent);
3266 Set_Referenced (Cunit_Entity (Get_Source_Unit (Ent)));
3271 Ent := Homonym (Ent);
3280 procedure Undefined (Nvis : Boolean) is
3281 Emsg : Error_Msg_Id;
3284 -- We should never find an undefined internal name. If we do, then
3285 -- see if we have previous errors. If so, ignore on the grounds that
3286 -- it is probably a cascaded message (e.g. a block label from a badly
3287 -- formed block). If no previous errors, then we have a real internal
3288 -- error of some kind so raise an exception.
3290 if Is_Internal_Name (Chars (N)) then
3291 if Total_Errors_Detected /= 0 then
3294 raise Program_Error;
3298 -- A very specialized error check, if the undefined variable is
3299 -- a case tag, and the case type is an enumeration type, check
3300 -- for a possible misspelling, and if so, modify the identifier
3302 -- Named aggregate should also be handled similarly ???
3304 if Nkind (N) = N_Identifier
3305 and then Nkind (Parent (N)) = N_Case_Statement_Alternative
3307 Get_Name_String (Chars (N));
3310 Case_Str : constant String := Name_Buffer (1 .. Name_Len);
3311 Case_Stm : constant Node_Id := Parent (Parent (N));
3312 Case_Typ : constant Entity_Id := Etype (Expression (Case_Stm));
3313 Case_Rtp : constant Entity_Id := Root_Type (Case_Typ);
3318 if Is_Enumeration_Type (Case_Typ)
3319 and then Case_Rtp /= Standard_Character
3320 and then Case_Rtp /= Standard_Wide_Character
3321 and then Case_Rtp /= Standard_Wide_Wide_Character
3323 Lit := First_Literal (Case_Typ);
3324 Get_Name_String (Chars (Lit));
3326 if Chars (Lit) /= Chars (N)
3327 and then Is_Bad_Spelling_Of
3328 (Case_Str, Name_Buffer (1 .. Name_Len))
3330 Error_Msg_Node_2 := Lit;
3332 ("& is undefined, assume misspelling of &", N);
3333 Rewrite (N, New_Occurrence_Of (Lit, Sloc (N)));
3337 Lit := Next_Literal (Lit);
3342 -- Normal processing
3344 Set_Entity (N, Any_Id);
3345 Set_Etype (N, Any_Type);
3347 -- We use the table Urefs to keep track of entities for which we
3348 -- have issued errors for undefined references. Multiple errors
3349 -- for a single name are normally suppressed, however we modify
3350 -- the error message to alert the programmer to this effect.
3352 for J in Urefs.First .. Urefs.Last loop
3353 if Chars (N) = Chars (Urefs.Table (J).Node) then
3354 if Urefs.Table (J).Err /= No_Error_Msg
3355 and then Sloc (N) /= Urefs.Table (J).Loc
3357 Error_Msg_Node_1 := Urefs.Table (J).Node;
3359 if Urefs.Table (J).Nvis then
3360 Change_Error_Text (Urefs.Table (J).Err,
3361 "& is not visible (more references follow)");
3363 Change_Error_Text (Urefs.Table (J).Err,
3364 "& is undefined (more references follow)");
3367 Urefs.Table (J).Err := No_Error_Msg;
3370 -- Although we will set Msg False, and thus suppress the
3371 -- message, we also set Error_Posted True, to avoid any
3372 -- cascaded messages resulting from the undefined reference.
3375 Set_Error_Posted (N, True);
3380 -- If entry not found, this is first undefined occurrence
3383 Error_Msg_N ("& is not visible!", N);
3387 Error_Msg_N ("& is undefined!", N);
3390 -- A very bizarre special check, if the undefined identifier
3391 -- is put or put_line, then add a special error message (since
3392 -- this is a very common error for beginners to make).
3394 if Chars (N) = Name_Put or else Chars (N) = Name_Put_Line then
3396 ("\\possible missing `WITH Ada.Text_'I'O; " &
3397 "USE Ada.Text_'I'O`!", N);
3399 -- Another special check if N is the prefix of a selected
3400 -- component which is a known unit, add message complaining
3401 -- about missing with for this unit.
3403 elsif Nkind (Parent (N)) = N_Selected_Component
3404 and then N = Prefix (Parent (N))
3405 and then Is_Known_Unit (Parent (N))
3407 Error_Msg_Node_2 := Selector_Name (Parent (N));
3408 Error_Msg_N ("\\missing `WITH &.&;`", Prefix (Parent (N)));
3411 -- Now check for possible misspellings
3413 Get_Name_String (Chars (N));
3417 Ematch : Entity_Id := Empty;
3419 Last_Name_Id : constant Name_Id :=
3420 Name_Id (Nat (First_Name_Id) +
3421 Name_Entries_Count - 1);
3423 S : constant String (1 .. Name_Len) :=
3424 Name_Buffer (1 .. Name_Len);
3427 for N in First_Name_Id .. Last_Name_Id loop
3428 E := Get_Name_Entity_Id (N);
3431 and then (Is_Immediately_Visible (E)
3433 Is_Potentially_Use_Visible (E))
3435 Get_Name_String (N);
3437 if Is_Bad_Spelling_Of
3438 (S, Name_Buffer (1 .. Name_Len))
3446 if Present (Ematch) then
3447 Error_Msg_NE ("\possible misspelling of&", N, Ematch);
3452 -- Make entry in undefined references table unless the full errors
3453 -- switch is set, in which case by refraining from generating the
3454 -- table entry, we guarantee that we get an error message for every
3455 -- undefined reference.
3457 if not All_Errors_Mode then
3468 -- Start of processing for Find_Direct_Name
3471 -- If the entity pointer is already set, this is an internal node, or
3472 -- a node that is analyzed more than once, after a tree modification.
3473 -- In such a case there is no resolution to perform, just set the type.
3475 if Present (Entity (N)) then
3476 if Is_Type (Entity (N)) then
3477 Set_Etype (N, Entity (N));
3481 Entyp : constant Entity_Id := Etype (Entity (N));
3484 -- One special case here. If the Etype field is already set,
3485 -- and references the packed array type corresponding to the
3486 -- etype of the referenced entity, then leave it alone. This
3487 -- happens for trees generated from Exp_Pakd, where expressions
3488 -- can be deliberately "mis-typed" to the packed array type.
3490 if Is_Array_Type (Entyp)
3491 and then Is_Packed (Entyp)
3492 and then Present (Etype (N))
3493 and then Etype (N) = Packed_Array_Type (Entyp)
3497 -- If not that special case, then just reset the Etype
3500 Set_Etype (N, Etype (Entity (N)));
3508 -- Here if Entity pointer was not set, we need full visibility analysis
3509 -- First we generate debugging output if the debug E flag is set.
3511 if Debug_Flag_E then
3512 Write_Str ("Looking for ");
3513 Write_Name (Chars (N));
3517 Homonyms := Current_Entity (N);
3518 Nvis_Entity := False;
3521 while Present (E) loop
3523 -- If entity is immediately visible or potentially use
3524 -- visible, then process the entity and we are done.
3526 if Is_Immediately_Visible (E) then
3527 goto Immediately_Visible_Entity;
3529 elsif Is_Potentially_Use_Visible (E) then
3530 goto Potentially_Use_Visible_Entity;
3532 -- Note if a known but invisible entity encountered
3534 elsif Known_But_Invisible (E) then
3535 Nvis_Entity := True;
3538 -- Move to next entity in chain and continue search
3543 -- If no entries on homonym chain that were potentially visible,
3544 -- and no entities reasonably considered as non-visible, then
3545 -- we have a plain undefined reference, with no additional
3546 -- explanation required!
3548 if not Nvis_Entity then
3549 Undefined (Nvis => False);
3551 -- Otherwise there is at least one entry on the homonym chain that
3552 -- is reasonably considered as being known and non-visible.
3560 -- Processing for a potentially use visible entry found. We must search
3561 -- the rest of the homonym chain for two reasons. First, if there is a
3562 -- directly visible entry, then none of the potentially use-visible
3563 -- entities are directly visible (RM 8.4(10)). Second, we need to check
3564 -- for the case of multiple potentially use-visible entries hiding one
3565 -- another and as a result being non-directly visible (RM 8.4(11)).
3567 <<Potentially_Use_Visible_Entity>> declare
3568 Only_One_Visible : Boolean := True;
3569 All_Overloadable : Boolean := Is_Overloadable (E);
3573 while Present (E2) loop
3574 if Is_Immediately_Visible (E2) then
3576 -- If the use-visible entity comes from the actual for a
3577 -- formal package, it hides a directly visible entity from
3578 -- outside the instance.
3580 if From_Actual_Package (E)
3581 and then Scope_Depth (E2) < Scope_Depth (Inst)
3586 goto Immediately_Visible_Entity;
3589 elsif Is_Potentially_Use_Visible (E2) then
3590 Only_One_Visible := False;
3591 All_Overloadable := All_Overloadable and Is_Overloadable (E2);
3593 -- Ada 2005 (AI-262): Protect against a form of Beujolais effect
3594 -- that can occurr in private_with clauses. Example:
3597 -- private with B; package A is
3598 -- package C is function B return Integer;
3600 -- V1 : Integer := B;
3601 -- private function B return Integer;
3602 -- V2 : Integer := B;
3605 -- V1 resolves to A.B, but V2 resolves to library unit B
3607 elsif Ekind (E2) = E_Function
3608 and then Scope (E2) = Standard_Standard
3609 and then Has_Private_With (E2)
3611 Only_One_Visible := False;
3612 All_Overloadable := False;
3613 Nvis_Is_Private_Subprg := True;
3620 -- On falling through this loop, we have checked that there are no
3621 -- immediately visible entities. Only_One_Visible is set if exactly
3622 -- one potentially use visible entity exists. All_Overloadable is
3623 -- set if all the potentially use visible entities are overloadable.
3624 -- The condition for legality is that either there is one potentially
3625 -- use visible entity, or if there is more than one, then all of them
3626 -- are overloadable.
3628 if Only_One_Visible or All_Overloadable then
3631 -- If there is more than one potentially use-visible entity and at
3632 -- least one of them non-overloadable, we have an error (RM 8.4(11).
3633 -- Note that E points to the first such entity on the homonym list.
3634 -- Special case: if one of the entities is declared in an actual
3635 -- package, it was visible in the generic, and takes precedence over
3636 -- other entities that are potentially use-visible. Same if it is
3637 -- declared in a local instantiation of the current instance.
3642 -- Find current instance
3644 Inst := Current_Scope;
3645 while Present (Inst)
3646 and then Inst /= Standard_Standard
3648 if Is_Generic_Instance (Inst) then
3652 Inst := Scope (Inst);
3656 while Present (E2) loop
3657 if From_Actual_Package (E2)
3659 (Is_Generic_Instance (Scope (E2))
3660 and then Scope_Depth (Scope (E2)) > Scope_Depth (Inst))
3673 Is_Predefined_File_Name (Unit_File_Name (Current_Sem_Unit))
3675 -- A use-clause in the body of a system file creates conflict
3676 -- with some entity in a user scope, while rtsfind is active.
3677 -- Keep only the entity coming from another predefined unit.
3680 while Present (E2) loop
3681 if Is_Predefined_File_Name
3682 (Unit_File_Name (Get_Source_Unit (Sloc (E2))))
3691 -- Entity must exist because predefined unit is correct
3693 raise Program_Error;
3702 -- Come here with E set to the first immediately visible entity on
3703 -- the homonym chain. This is the one we want unless there is another
3704 -- immediately visible entity further on in the chain for a more
3705 -- inner scope (RM 8.3(8)).
3707 <<Immediately_Visible_Entity>> declare
3712 -- Find scope level of initial entity. When compiling through
3713 -- Rtsfind, the previous context is not completely invisible, and
3714 -- an outer entity may appear on the chain, whose scope is below
3715 -- the entry for Standard that delimits the current scope stack.
3716 -- Indicate that the level for this spurious entry is outside of
3717 -- the current scope stack.
3719 Level := Scope_Stack.Last;
3721 Scop := Scope_Stack.Table (Level).Entity;
3722 exit when Scop = Scope (E);
3724 exit when Scop = Standard_Standard;
3727 -- Now search remainder of homonym chain for more inner entry
3728 -- If the entity is Standard itself, it has no scope, and we
3729 -- compare it with the stack entry directly.
3732 while Present (E2) loop
3733 if Is_Immediately_Visible (E2) then
3735 -- If a generic package contains a local declaration that
3736 -- has the same name as the generic, there may be a visibility
3737 -- conflict in an instance, where the local declaration must
3738 -- also hide the name of the corresponding package renaming.
3739 -- We check explicitly for a package declared by a renaming,
3740 -- whose renamed entity is an instance that is on the scope
3741 -- stack, and that contains a homonym in the same scope. Once
3742 -- we have found it, we know that the package renaming is not
3743 -- immediately visible, and that the identifier denotes the
3744 -- other entity (and its homonyms if overloaded).
3746 if Scope (E) = Scope (E2)
3747 and then Ekind (E) = E_Package
3748 and then Present (Renamed_Object (E))
3749 and then Is_Generic_Instance (Renamed_Object (E))
3750 and then In_Open_Scopes (Renamed_Object (E))
3751 and then Comes_From_Source (N)
3753 Set_Is_Immediately_Visible (E, False);
3757 for J in Level + 1 .. Scope_Stack.Last loop
3758 if Scope_Stack.Table (J).Entity = Scope (E2)
3759 or else Scope_Stack.Table (J).Entity = E2
3772 -- At the end of that loop, E is the innermost immediately
3773 -- visible entity, so we are all set.
3776 -- Come here with entity found, and stored in E
3780 if Comes_From_Source (N)
3781 and then Is_Remote_Access_To_Subprogram_Type (E)
3782 and then Expander_Active
3783 and then Get_PCS_Name /= Name_No_DSA
3786 New_Occurrence_Of (Equivalent_Type (E), Sloc (N)));
3791 -- Why no Style_Check here???
3796 Set_Etype (N, Get_Full_View (Etype (E)));
3799 if Debug_Flag_E then
3800 Write_Str (" found ");
3801 Write_Entity_Info (E, " ");
3804 -- If the Ekind of the entity is Void, it means that all homonyms
3805 -- are hidden from all visibility (RM 8.3(5,14-20)). However, this
3806 -- test is skipped if the current scope is a record and the name is
3807 -- a pragma argument expression (case of Atomic and Volatile pragmas
3808 -- and possibly other similar pragmas added later, which are allowed
3809 -- to reference components in the current record).
3811 if Ekind (E) = E_Void
3813 (not Is_Record_Type (Current_Scope)
3814 or else Nkind (Parent (N)) /= N_Pragma_Argument_Association)
3816 Premature_Usage (N);
3818 -- If the entity is overloadable, collect all interpretations of the
3819 -- name for subsequent overload resolution. We optimize a bit here to
3820 -- do this only if we have an overloadable entity that is not on its
3821 -- own on the homonym chain.
3823 elsif Is_Overloadable (E)
3824 and then (Present (Homonym (E)) or else Current_Entity (N) /= E)
3826 Collect_Interps (N);
3828 -- If no homonyms were visible, the entity is unambiguous
3830 if not Is_Overloaded (N) then
3831 Generate_Reference (E, N);
3834 -- Case of non-overloadable entity, set the entity providing that
3835 -- we do not have the case of a discriminant reference within a
3836 -- default expression. Such references are replaced with the
3837 -- corresponding discriminal, which is the formal corresponding to
3838 -- to the discriminant in the initialization procedure.
3841 -- Entity is unambiguous, indicate that it is referenced here. One
3842 -- slightly odd case is that we do not want to set the Referenced
3843 -- flag if the entity is a label, and the identifier is the label
3844 -- in the source, since this is not a reference from the point of
3847 if Nkind (Parent (N)) = N_Label then
3849 R : constant Boolean := Referenced (E);
3852 Generate_Reference (E, N);
3853 Set_Referenced (E, R);
3856 -- Normal case, not a label: generate reference
3858 -- ??? It is too early to generate a reference here even if
3859 -- the entity is unambiguous, because the tree is not
3860 -- sufficiently typed at this point for Generate_Reference to
3861 -- determine whether this reference modifies the denoted object
3862 -- (because implicit derefences cannot be identified prior to
3863 -- full type resolution).
3866 Generate_Reference (E, N);
3867 Check_Nested_Access (E);
3870 -- Set Entity, with style check if need be. For a discriminant
3871 -- reference, replace by the corresponding discriminal, i.e. the
3872 -- parameter of the initialization procedure that corresponds to
3873 -- the discriminant. If this replacement is being performed, there
3874 -- is no style check to perform.
3876 -- This replacement must not be done if we are currently
3877 -- processing a generic spec or body, because the discriminal
3878 -- has not been not generated in this case.
3880 if not In_Default_Expression
3881 or else Ekind (E) /= E_Discriminant
3882 or else Inside_A_Generic
3884 Set_Entity_With_Style_Check (N, E);
3886 -- The replacement is not done either for a task discriminant that
3887 -- appears in a default expression of an entry parameter. See
3888 -- Expand_Discriminant in exp_ch2 for details on their handling.
3890 elsif Is_Concurrent_Type (Scope (E)) then
3897 and then Nkind (P) /= N_Parameter_Specification
3898 and then Nkind (P) /= N_Component_Declaration
3904 and then Nkind (P) = N_Parameter_Specification
3908 Set_Entity (N, Discriminal (E));
3912 -- Otherwise, this is a discriminant in a context in which
3913 -- it is a reference to the corresponding parameter of the
3914 -- init proc for the enclosing type.
3917 Set_Entity (N, Discriminal (E));
3921 end Find_Direct_Name;
3923 ------------------------
3924 -- Find_Expanded_Name --
3925 ------------------------
3927 -- This routine searches the homonym chain of the entity until it finds
3928 -- an entity declared in the scope denoted by the prefix. If the entity
3929 -- is private, it may nevertheless be immediately visible, if we are in
3930 -- the scope of its declaration.
3932 procedure Find_Expanded_Name (N : Node_Id) is
3933 Selector : constant Node_Id := Selector_Name (N);
3934 Candidate : Entity_Id := Empty;
3940 P_Name := Entity (Prefix (N));
3943 -- If the prefix is a renamed package, look for the entity
3944 -- in the original package.
3946 if Ekind (P_Name) = E_Package
3947 and then Present (Renamed_Object (P_Name))
3949 P_Name := Renamed_Object (P_Name);
3951 -- Rewrite node with entity field pointing to renamed object
3953 Rewrite (Prefix (N), New_Copy (Prefix (N)));
3954 Set_Entity (Prefix (N), P_Name);
3956 -- If the prefix is an object of a concurrent type, look for
3957 -- the entity in the associated task or protected type.
3959 elsif Is_Concurrent_Type (Etype (P_Name)) then
3960 P_Name := Etype (P_Name);
3963 Id := Current_Entity (Selector);
3966 Is_New_Candidate : Boolean;
3969 while Present (Id) loop
3970 if Scope (Id) = P_Name then
3972 Is_New_Candidate := True;
3974 -- Ada 2005 (AI-217): Handle shadow entities associated with types
3975 -- declared in limited-withed nested packages. We don't need to
3976 -- handle E_Incomplete_Subtype entities because the entities in
3977 -- the limited view are always E_Incomplete_Type entities (see
3978 -- Build_Limited_Views). Regarding the expression used to evaluate
3979 -- the scope, it is important to note that the limited view also
3980 -- has shadow entities associated nested packages. For this reason
3981 -- the correct scope of the entity is the scope of the real entity
3982 -- The non-limited view may itself be incomplete, in which case
3983 -- get the full view if available.
3985 elsif From_With_Type (Id)
3986 and then Is_Type (Id)
3987 and then Ekind (Id) = E_Incomplete_Type
3988 and then Present (Non_Limited_View (Id))
3989 and then Scope (Non_Limited_View (Id)) = P_Name
3991 Candidate := Get_Full_View (Non_Limited_View (Id));
3992 Is_New_Candidate := True;
3995 Is_New_Candidate := False;
3998 if Is_New_Candidate then
3999 if Is_Child_Unit (Id) then
4000 exit when Is_Visible_Child_Unit (Id)
4001 or else Is_Immediately_Visible (Id);
4004 exit when not Is_Hidden (Id)
4005 or else Is_Immediately_Visible (Id);
4014 and then (Ekind (P_Name) = E_Procedure
4016 Ekind (P_Name) = E_Function)
4017 and then Is_Generic_Instance (P_Name)
4019 -- Expanded name denotes entity in (instance of) generic subprogram.
4020 -- The entity may be in the subprogram instance, or may denote one of
4021 -- the formals, which is declared in the enclosing wrapper package.
4023 P_Name := Scope (P_Name);
4025 Id := Current_Entity (Selector);
4026 while Present (Id) loop
4027 exit when Scope (Id) = P_Name;
4032 if No (Id) or else Chars (Id) /= Chars (Selector) then
4033 Set_Etype (N, Any_Type);
4035 -- If we are looking for an entity defined in System, try to
4036 -- find it in the child package that may have been provided as
4037 -- an extension to System. The Extend_System pragma will have
4038 -- supplied the name of the extension, which may have to be loaded.
4040 if Chars (P_Name) = Name_System
4041 and then Scope (P_Name) = Standard_Standard
4042 and then Present (System_Extend_Unit)
4043 and then Present_System_Aux (N)
4045 Set_Entity (Prefix (N), System_Aux_Id);
4046 Find_Expanded_Name (N);
4049 elsif Nkind (Selector) = N_Operator_Symbol
4050 and then Has_Implicit_Operator (N)
4052 -- There is an implicit instance of the predefined operator in
4053 -- the given scope. The operator entity is defined in Standard.
4054 -- Has_Implicit_Operator makes the node into an Expanded_Name.
4058 elsif Nkind (Selector) = N_Character_Literal
4059 and then Has_Implicit_Character_Literal (N)
4061 -- If there is no literal defined in the scope denoted by the
4062 -- prefix, the literal may belong to (a type derived from)
4063 -- Standard_Character, for which we have no explicit literals.
4068 -- If the prefix is a single concurrent object, use its
4069 -- name in the error message, rather than that of the
4072 if Is_Concurrent_Type (P_Name)
4073 and then Is_Internal_Name (Chars (P_Name))
4075 Error_Msg_Node_2 := Entity (Prefix (N));
4077 Error_Msg_Node_2 := P_Name;
4080 if P_Name = System_Aux_Id then
4081 P_Name := Scope (P_Name);
4082 Set_Entity (Prefix (N), P_Name);
4085 if Present (Candidate) then
4087 -- If we know that the unit is a child unit we can give a more
4088 -- accurate error message.
4090 if Is_Child_Unit (Candidate) then
4092 -- If the candidate is a private child unit and we are in
4093 -- the visible part of a public unit, specialize the error
4094 -- message. There might be a private with_clause for it,
4095 -- but it is not currently active.
4097 if Is_Private_Descendant (Candidate)
4098 and then Ekind (Current_Scope) = E_Package
4099 and then not In_Private_Part (Current_Scope)
4100 and then not Is_Private_Descendant (Current_Scope)
4102 Error_Msg_N ("private child unit& is not visible here",
4105 -- Normal case where we have a missing with for a child unit
4108 Error_Msg_Qual_Level := 99;
4109 Error_Msg_NE ("missing `WITH &;`", Selector, Candidate);
4110 Error_Msg_Qual_Level := 0;
4113 -- Here we don't know that this is a child unit
4116 Error_Msg_NE ("& is not a visible entity of&", N, Selector);
4120 -- Within the instantiation of a child unit, the prefix may
4121 -- denote the parent instance, but the selector has the name
4122 -- of the original child. Find whether we are within the
4123 -- corresponding instance, and get the proper entity, which
4124 -- can only be an enclosing scope.
4127 and then In_Open_Scopes (P_Name)
4128 and then Is_Generic_Instance (P_Name)
4131 S : Entity_Id := Current_Scope;
4135 for J in reverse 0 .. Scope_Stack.Last loop
4136 S := Scope_Stack.Table (J).Entity;
4138 exit when S = Standard_Standard;
4140 if Ekind (S) = E_Function
4141 or else Ekind (S) = E_Package
4142 or else Ekind (S) = E_Procedure
4144 P := Generic_Parent (Specification
4145 (Unit_Declaration_Node (S)));
4148 and then Chars (Scope (P)) = Chars (O_Name)
4149 and then Chars (P) = Chars (Selector)
4160 -- If this is a selection from Ada, System or Interfaces, then
4161 -- we assume a missing with for the corresponding package.
4163 if Is_Known_Unit (N) then
4164 if not Error_Posted (N) then
4165 Error_Msg_Node_2 := Selector;
4166 Error_Msg_N ("missing `WITH &.&;`", Prefix (N));
4169 -- If this is a selection from a dummy package, then suppress
4170 -- the error message, of course the entity is missing if the
4171 -- package is missing!
4173 elsif Sloc (Error_Msg_Node_2) = No_Location then
4176 -- Here we have the case of an undefined component
4179 Error_Msg_NE ("& not declared in&", N, Selector);
4181 -- Check for misspelling of some entity in prefix
4183 Id := First_Entity (P_Name);
4184 Get_Name_String (Chars (Selector));
4187 S : constant String (1 .. Name_Len) :=
4188 Name_Buffer (1 .. Name_Len);
4190 while Present (Id) loop
4191 Get_Name_String (Chars (Id));
4192 if Is_Bad_Spelling_Of
4193 (Name_Buffer (1 .. Name_Len), S)
4194 and then not Is_Internal_Name (Chars (Id))
4197 ("possible misspelling of&", Selector, Id);
4205 -- Specialize the message if this may be an instantiation
4206 -- of a child unit that was not mentioned in the context.
4208 if Nkind (Parent (N)) = N_Package_Instantiation
4209 and then Is_Generic_Instance (Entity (Prefix (N)))
4210 and then Is_Compilation_Unit
4211 (Generic_Parent (Parent (Entity (Prefix (N)))))
4213 Error_Msg_Node_2 := Selector;
4214 Error_Msg_N ("\missing `WITH &.&;`", Prefix (N));
4224 if Comes_From_Source (N)
4225 and then Is_Remote_Access_To_Subprogram_Type (Id)
4226 and then Present (Equivalent_Type (Id))
4228 -- If we are not actually generating distribution code (i.e. the
4229 -- current PCS is the dummy non-distributed version), then the
4230 -- Equivalent_Type will be missing, and Id should be treated as
4231 -- a regular access-to-subprogram type.
4233 Id := Equivalent_Type (Id);
4234 Set_Chars (Selector, Chars (Id));
4237 -- Ada 2005 (AI-50217): Check usage of entities in limited withed units
4239 if Ekind (P_Name) = E_Package
4240 and then From_With_Type (P_Name)
4242 if From_With_Type (Id)
4243 or else Is_Type (Id)
4244 or else Ekind (Id) = E_Package
4249 ("limited withed package can only be used to access "
4250 & " incomplete types",
4255 if Is_Task_Type (P_Name)
4256 and then ((Ekind (Id) = E_Entry
4257 and then Nkind (Parent (N)) /= N_Attribute_Reference)
4259 (Ekind (Id) = E_Entry_Family
4261 Nkind (Parent (Parent (N))) /= N_Attribute_Reference))
4263 -- It is an entry call after all, either to the current task (which
4264 -- will deadlock) or to an enclosing task.
4266 Analyze_Selected_Component (N);
4270 Change_Selected_Component_To_Expanded_Name (N);
4272 -- Do style check and generate reference, but skip both steps if this
4273 -- entity has homonyms, since we may not have the right homonym set yet.
4274 -- The proper homonym will be set during the resolve phase.
4276 if Has_Homonym (Id) then
4279 Set_Entity_With_Style_Check (N, Id);
4280 Generate_Reference (Id, N);
4283 if Is_Type (Id) then
4286 Set_Etype (N, Get_Full_View (Etype (Id)));
4289 -- If the Ekind of the entity is Void, it means that all homonyms are
4290 -- hidden from all visibility (RM 8.3(5,14-20)).
4292 if Ekind (Id) = E_Void then
4293 Premature_Usage (N);
4295 elsif Is_Overloadable (Id)
4296 and then Present (Homonym (Id))
4299 H : Entity_Id := Homonym (Id);
4302 while Present (H) loop
4303 if Scope (H) = Scope (Id)
4306 or else Is_Immediately_Visible (H))
4308 Collect_Interps (N);
4315 -- If an extension of System is present, collect possible explicit
4316 -- overloadings declared in the extension.
4318 if Chars (P_Name) = Name_System
4319 and then Scope (P_Name) = Standard_Standard
4320 and then Present (System_Extend_Unit)
4321 and then Present_System_Aux (N)
4323 H := Current_Entity (Id);
4325 while Present (H) loop
4326 if Scope (H) = System_Aux_Id then
4327 Add_One_Interp (N, H, Etype (H));
4336 if Nkind (Selector_Name (N)) = N_Operator_Symbol
4337 and then Scope (Id) /= Standard_Standard
4339 -- In addition to user-defined operators in the given scope, there
4340 -- may be an implicit instance of the predefined operator. The
4341 -- operator (defined in Standard) is found in Has_Implicit_Operator,
4342 -- and added to the interpretations. Procedure Add_One_Interp will
4343 -- determine which hides which.
4345 if Has_Implicit_Operator (N) then
4349 end Find_Expanded_Name;
4351 -------------------------
4352 -- Find_Renamed_Entity --
4353 -------------------------
4355 function Find_Renamed_Entity
4359 Is_Actual : Boolean := False) return Entity_Id
4362 I1 : Interp_Index := 0; -- Suppress junk warnings
4368 function Enclosing_Instance return Entity_Id;
4369 -- If the renaming determines the entity for the default of a formal
4370 -- subprogram nested within another instance, choose the innermost
4371 -- candidate. This is because if the formal has a box, and we are within
4372 -- an enclosing instance where some candidate interpretations are local
4373 -- to this enclosing instance, we know that the default was properly
4374 -- resolved when analyzing the generic, so we prefer the local
4375 -- candidates to those that are external. This is not always the case
4376 -- but is a reasonable heuristic on the use of nested generics. The
4377 -- proper solution requires a full renaming model.
4379 function Is_Visible_Operation (Op : Entity_Id) return Boolean;
4380 -- If the renamed entity is an implicit operator, check whether it is
4381 -- visible because its operand type is properly visible. This check
4382 -- applies to explicit renamed entities that appear in the source in a
4383 -- renaming declaration or a formal subprogram instance, but not to
4384 -- default generic actuals with a name.
4386 function Report_Overload return Entity_Id;
4387 -- List possible interpretations, and specialize message in the
4388 -- case of a generic actual.
4390 function Within (Inner, Outer : Entity_Id) return Boolean;
4391 -- Determine whether a candidate subprogram is defined within the
4392 -- enclosing instance. If yes, it has precedence over outer candidates.
4394 ------------------------
4395 -- Enclosing_Instance --
4396 ------------------------
4398 function Enclosing_Instance return Entity_Id is
4402 if not Is_Generic_Instance (Current_Scope)
4403 and then not Is_Actual
4408 S := Scope (Current_Scope);
4409 while S /= Standard_Standard loop
4410 if Is_Generic_Instance (S) then
4418 end Enclosing_Instance;
4420 --------------------------
4421 -- Is_Visible_Operation --
4422 --------------------------
4424 function Is_Visible_Operation (Op : Entity_Id) return Boolean is
4430 if Ekind (Op) /= E_Operator
4431 or else Scope (Op) /= Standard_Standard
4432 or else (In_Instance
4435 or else Present (Enclosing_Instance)))
4440 -- For a fixed point type operator, check the resulting type,
4441 -- because it may be a mixed mode integer * fixed operation.
4443 if Present (Next_Formal (First_Formal (New_S)))
4444 and then Is_Fixed_Point_Type (Etype (New_S))
4446 Typ := Etype (New_S);
4448 Typ := Etype (First_Formal (New_S));
4451 Btyp := Base_Type (Typ);
4453 if Nkind (Nam) /= N_Expanded_Name then
4454 return (In_Open_Scopes (Scope (Btyp))
4455 or else Is_Potentially_Use_Visible (Btyp)
4456 or else In_Use (Btyp)
4457 or else In_Use (Scope (Btyp)));
4460 Scop := Entity (Prefix (Nam));
4462 if Ekind (Scop) = E_Package
4463 and then Present (Renamed_Object (Scop))
4465 Scop := Renamed_Object (Scop);
4468 -- Operator is visible if prefix of expanded name denotes
4469 -- scope of type, or else type type is defined in System_Aux
4470 -- and the prefix denotes System.
4472 return Scope (Btyp) = Scop
4473 or else (Scope (Btyp) = System_Aux_Id
4474 and then Scope (Scope (Btyp)) = Scop);
4477 end Is_Visible_Operation;
4483 function Within (Inner, Outer : Entity_Id) return Boolean is
4487 Sc := Scope (Inner);
4488 while Sc /= Standard_Standard loop
4499 ---------------------
4500 -- Report_Overload --
4501 ---------------------
4503 function Report_Overload return Entity_Id is
4507 ("ambiguous actual subprogram&, " &
4508 "possible interpretations:", N, Nam);
4511 ("ambiguous subprogram, " &
4512 "possible interpretations:", N);
4515 List_Interps (Nam, N);
4517 end Report_Overload;
4519 -- Start of processing for Find_Renamed_Entry
4523 Candidate_Renaming := Empty;
4525 if not Is_Overloaded (Nam) then
4526 if Entity_Matches_Spec (Entity (Nam), New_S)
4527 and then Is_Visible_Operation (Entity (Nam))
4529 Old_S := Entity (Nam);
4532 Present (First_Formal (Entity (Nam)))
4533 and then Present (First_Formal (New_S))
4534 and then (Base_Type (Etype (First_Formal (Entity (Nam))))
4535 = Base_Type (Etype (First_Formal (New_S))))
4537 Candidate_Renaming := Entity (Nam);
4541 Get_First_Interp (Nam, Ind, It);
4542 while Present (It.Nam) loop
4543 if Entity_Matches_Spec (It.Nam, New_S)
4544 and then Is_Visible_Operation (It.Nam)
4546 if Old_S /= Any_Id then
4548 -- Note: The call to Disambiguate only happens if a
4549 -- previous interpretation was found, in which case I1
4550 -- has received a value.
4552 It1 := Disambiguate (Nam, I1, Ind, Etype (Old_S));
4554 if It1 = No_Interp then
4555 Inst := Enclosing_Instance;
4557 if Present (Inst) then
4558 if Within (It.Nam, Inst) then
4560 elsif Within (Old_S, Inst) then
4563 return Report_Overload;
4567 return Report_Overload;
4581 Present (First_Formal (It.Nam))
4582 and then Present (First_Formal (New_S))
4583 and then (Base_Type (Etype (First_Formal (It.Nam)))
4584 = Base_Type (Etype (First_Formal (New_S))))
4586 Candidate_Renaming := It.Nam;
4589 Get_Next_Interp (Ind, It);
4592 Set_Entity (Nam, Old_S);
4593 Set_Is_Overloaded (Nam, False);
4597 end Find_Renamed_Entity;
4599 -----------------------------
4600 -- Find_Selected_Component --
4601 -----------------------------
4603 procedure Find_Selected_Component (N : Node_Id) is
4604 P : constant Node_Id := Prefix (N);
4607 -- Entity denoted by prefix
4617 if Nkind (P) = N_Error then
4620 -- If the selector already has an entity, the node has been constructed
4621 -- in the course of expansion, and is known to be valid. Do not verify
4622 -- that it is defined for the type (it may be a private component used
4623 -- in the expansion of record equality).
4625 elsif Present (Entity (Selector_Name (N))) then
4628 or else Etype (N) = Any_Type
4631 Sel_Name : constant Node_Id := Selector_Name (N);
4632 Selector : constant Entity_Id := Entity (Sel_Name);
4636 Set_Etype (Sel_Name, Etype (Selector));
4638 if not Is_Entity_Name (P) then
4642 -- Build an actual subtype except for the first parameter
4643 -- of an init proc, where this actual subtype is by
4644 -- definition incorrect, since the object is uninitialized
4645 -- (and does not even have defined discriminants etc.)
4647 if Is_Entity_Name (P)
4648 and then Ekind (Entity (P)) = E_Function
4650 Nam := New_Copy (P);
4652 if Is_Overloaded (P) then
4653 Save_Interps (P, Nam);
4657 Make_Function_Call (Sloc (P), Name => Nam));
4659 Analyze_Selected_Component (N);
4662 elsif Ekind (Selector) = E_Component
4663 and then (not Is_Entity_Name (P)
4664 or else Chars (Entity (P)) /= Name_uInit)
4667 Build_Actual_Subtype_Of_Component (
4668 Etype (Selector), N);
4673 if No (C_Etype) then
4674 C_Etype := Etype (Selector);
4676 Insert_Action (N, C_Etype);
4677 C_Etype := Defining_Identifier (C_Etype);
4680 Set_Etype (N, C_Etype);
4683 -- If this is the name of an entry or protected operation, and
4684 -- the prefix is an access type, insert an explicit dereference,
4685 -- so that entry calls are treated uniformly.
4687 if Is_Access_Type (Etype (P))
4688 and then Is_Concurrent_Type (Designated_Type (Etype (P)))
4691 New_P : constant Node_Id :=
4692 Make_Explicit_Dereference (Sloc (P),
4693 Prefix => Relocate_Node (P));
4696 Set_Etype (P, Designated_Type (Etype (Prefix (P))));
4700 -- If the selected component appears within a default expression
4701 -- and it has an actual subtype, the pre-analysis has not yet
4702 -- completed its analysis, because Insert_Actions is disabled in
4703 -- that context. Within the init proc of the enclosing type we
4704 -- must complete this analysis, if an actual subtype was created.
4706 elsif Inside_Init_Proc then
4708 Typ : constant Entity_Id := Etype (N);
4709 Decl : constant Node_Id := Declaration_Node (Typ);
4711 if Nkind (Decl) = N_Subtype_Declaration
4712 and then not Analyzed (Decl)
4713 and then Is_List_Member (Decl)
4714 and then No (Parent (Decl))
4717 Insert_Action (N, Decl);
4724 elsif Is_Entity_Name (P) then
4725 P_Name := Entity (P);
4727 -- The prefix may denote an enclosing type which is the completion
4728 -- of an incomplete type declaration.
4730 if Is_Type (P_Name) then
4731 Set_Entity (P, Get_Full_View (P_Name));
4732 Set_Etype (P, Entity (P));
4733 P_Name := Entity (P);
4736 P_Type := Base_Type (Etype (P));
4738 if Debug_Flag_E then
4739 Write_Str ("Found prefix type to be ");
4740 Write_Entity_Info (P_Type, " "); Write_Eol;
4743 -- First check for components of a record object (not the
4744 -- result of a call, which is handled below).
4746 if Is_Appropriate_For_Record (P_Type)
4747 and then not Is_Overloadable (P_Name)
4748 and then not Is_Type (P_Name)
4750 -- Selected component of record. Type checking will validate
4751 -- name of selector.
4752 -- ??? could we rewrite an implicit dereference into an explicit
4755 Analyze_Selected_Component (N);
4757 elsif Is_Appropriate_For_Entry_Prefix (P_Type)
4758 and then not In_Open_Scopes (P_Name)
4759 and then (not Is_Concurrent_Type (Etype (P_Name))
4760 or else not In_Open_Scopes (Etype (P_Name)))
4762 -- Call to protected operation or entry. Type checking is
4763 -- needed on the prefix.
4765 Analyze_Selected_Component (N);
4767 elsif (In_Open_Scopes (P_Name)
4768 and then Ekind (P_Name) /= E_Void
4769 and then not Is_Overloadable (P_Name))
4770 or else (Is_Concurrent_Type (Etype (P_Name))
4771 and then In_Open_Scopes (Etype (P_Name)))
4773 -- Prefix denotes an enclosing loop, block, or task, i.e. an
4774 -- enclosing construct that is not a subprogram or accept.
4776 Find_Expanded_Name (N);
4778 elsif Ekind (P_Name) = E_Package then
4779 Find_Expanded_Name (N);
4781 elsif Is_Overloadable (P_Name) then
4783 -- The subprogram may be a renaming (of an enclosing scope) as
4784 -- in the case of the name of the generic within an instantiation.
4786 if (Ekind (P_Name) = E_Procedure
4787 or else Ekind (P_Name) = E_Function)
4788 and then Present (Alias (P_Name))
4789 and then Is_Generic_Instance (Alias (P_Name))
4791 P_Name := Alias (P_Name);
4794 if Is_Overloaded (P) then
4796 -- The prefix must resolve to a unique enclosing construct
4799 Found : Boolean := False;
4804 Get_First_Interp (P, Ind, It);
4805 while Present (It.Nam) loop
4806 if In_Open_Scopes (It.Nam) then
4809 "prefix must be unique enclosing scope", N);
4810 Set_Entity (N, Any_Id);
4811 Set_Etype (N, Any_Type);
4820 Get_Next_Interp (Ind, It);
4825 if In_Open_Scopes (P_Name) then
4826 Set_Entity (P, P_Name);
4827 Set_Is_Overloaded (P, False);
4828 Find_Expanded_Name (N);
4831 -- If no interpretation as an expanded name is possible, it
4832 -- must be a selected component of a record returned by a
4833 -- function call. Reformat prefix as a function call, the rest
4834 -- is done by type resolution. If the prefix is procedure or
4835 -- entry, as is P.X; this is an error.
4837 if Ekind (P_Name) /= E_Function
4838 and then (not Is_Overloaded (P)
4840 Nkind (Parent (N)) = N_Procedure_Call_Statement)
4842 -- Prefix may mention a package that is hidden by a local
4843 -- declaration: let the user know. Scan the full homonym
4844 -- chain, the candidate package may be anywhere on it.
4846 if Present (Homonym (Current_Entity (P_Name))) then
4848 P_Name := Current_Entity (P_Name);
4850 while Present (P_Name) loop
4851 exit when Ekind (P_Name) = E_Package;
4852 P_Name := Homonym (P_Name);
4855 if Present (P_Name) then
4856 Error_Msg_Sloc := Sloc (Entity (Prefix (N)));
4859 ("package& is hidden by declaration#",
4862 Set_Entity (Prefix (N), P_Name);
4863 Find_Expanded_Name (N);
4866 P_Name := Entity (Prefix (N));
4871 ("invalid prefix in selected component&", N, P_Name);
4872 Change_Selected_Component_To_Expanded_Name (N);
4873 Set_Entity (N, Any_Id);
4874 Set_Etype (N, Any_Type);
4877 Nam := New_Copy (P);
4878 Save_Interps (P, Nam);
4880 Make_Function_Call (Sloc (P), Name => Nam));
4882 Analyze_Selected_Component (N);
4886 -- Remaining cases generate various error messages
4889 -- Format node as expanded name, to avoid cascaded errors
4891 Change_Selected_Component_To_Expanded_Name (N);
4892 Set_Entity (N, Any_Id);
4893 Set_Etype (N, Any_Type);
4895 -- Issue error message, but avoid this if error issued already.
4896 -- Use identifier of prefix if one is available.
4898 if P_Name = Any_Id then
4901 elsif Ekind (P_Name) = E_Void then
4902 Premature_Usage (P);
4904 elsif Nkind (P) /= N_Attribute_Reference then
4906 "invalid prefix in selected component&", P);
4908 if Is_Access_Type (P_Type)
4909 and then Ekind (Designated_Type (P_Type)) = E_Incomplete_Type
4912 ("\dereference must not be of an incomplete type " &
4918 "invalid prefix in selected component", P);
4923 -- If prefix is not the name of an entity, it must be an expression,
4924 -- whose type is appropriate for a record. This is determined by
4927 Analyze_Selected_Component (N);
4929 end Find_Selected_Component;
4935 procedure Find_Type (N : Node_Id) is
4945 elsif Nkind (N) = N_Attribute_Reference then
4947 -- Class attribute. This is not valid in Ada 83 mode, but we do not
4948 -- need to enforce that at this point, since the declaration of the
4949 -- tagged type in the prefix would have been flagged already.
4951 if Attribute_Name (N) = Name_Class then
4952 Check_Restriction (No_Dispatch, N);
4953 Find_Type (Prefix (N));
4955 -- Propagate error from bad prefix
4957 if Etype (Prefix (N)) = Any_Type then
4958 Set_Entity (N, Any_Type);
4959 Set_Etype (N, Any_Type);
4963 T := Base_Type (Entity (Prefix (N)));
4965 -- Case where type is not known to be tagged. Its appearance in
4966 -- the prefix of the 'Class attribute indicates that the full view
4969 if not Is_Tagged_Type (T) then
4970 if Ekind (T) = E_Incomplete_Type then
4972 -- It is legal to denote the class type of an incomplete
4973 -- type. The full type will have to be tagged, of course.
4974 -- In Ada2005 this usage is declared obsolescent, so we
4975 -- warn accordingly.
4977 -- ??? This test is temporarily disabled (always False)
4978 -- because it causes an unwanted warning on GNAT sources
4979 -- (built with -gnatg, which includes Warn_On_Obsolescent_
4980 -- Feature). Once this issue is cleared in the sources, it
4983 if not Is_Tagged_Type (T)
4984 and then Ada_Version >= Ada_05
4985 and then Warn_On_Obsolescent_Feature
4989 ("applying 'Class to an untagged imcomplete type"
4990 & " is an obsolescent feature (RM J.11)", N);
4993 Set_Is_Tagged_Type (T);
4994 Set_Primitive_Operations (T, New_Elmt_List);
4995 Make_Class_Wide_Type (T);
4996 Set_Entity (N, Class_Wide_Type (T));
4997 Set_Etype (N, Class_Wide_Type (T));
4999 elsif Ekind (T) = E_Private_Type
5000 and then not Is_Generic_Type (T)
5001 and then In_Private_Part (Scope (T))
5003 -- The Class attribute can be applied to an untagged private
5004 -- type fulfilled by a tagged type prior to the full type
5005 -- declaration (but only within the parent package's private
5006 -- part). Create the class-wide type now and check that the
5007 -- full type is tagged later during its analysis. Note that
5008 -- we do not mark the private type as tagged, unlike the
5009 -- case of incomplete types, because the type must still
5010 -- appear untagged to outside units.
5012 if No (Class_Wide_Type (T)) then
5013 Make_Class_Wide_Type (T);
5016 Set_Entity (N, Class_Wide_Type (T));
5017 Set_Etype (N, Class_Wide_Type (T));
5020 -- Should we introduce a type Any_Tagged and use Wrong_Type
5021 -- here, it would be a bit more consistent???
5024 ("tagged type required, found}",
5025 Prefix (N), First_Subtype (T));
5026 Set_Entity (N, Any_Type);
5030 -- Case of tagged type
5033 if Is_Concurrent_Type (T) then
5034 if No (Corresponding_Record_Type (Entity (Prefix (N)))) then
5036 -- Previous error. Use current type, which at least
5037 -- provides some operations.
5039 C := Entity (Prefix (N));
5042 C := Class_Wide_Type
5043 (Corresponding_Record_Type (Entity (Prefix (N))));
5047 C := Class_Wide_Type (Entity (Prefix (N)));
5050 Set_Entity_With_Style_Check (N, C);
5051 Generate_Reference (C, N);
5055 -- Base attribute, not allowed in Ada 83
5057 elsif Attribute_Name (N) = Name_Base then
5058 if Ada_Version = Ada_83 and then Comes_From_Source (N) then
5060 ("(Ada 83) Base attribute not allowed in subtype mark", N);
5063 Find_Type (Prefix (N));
5064 Typ := Entity (Prefix (N));
5066 if Ada_Version >= Ada_95
5067 and then not Is_Scalar_Type (Typ)
5068 and then not Is_Generic_Type (Typ)
5071 ("prefix of Base attribute must be scalar type",
5074 elsif Sloc (Typ) = Standard_Location
5075 and then Base_Type (Typ) = Typ
5076 and then Warn_On_Redundant_Constructs
5079 ("?redudant attribute, & is its own base type", N, Typ);
5082 T := Base_Type (Typ);
5084 -- Rewrite attribute reference with type itself (see similar
5085 -- processing in Analyze_Attribute, case Base). Preserve
5086 -- prefix if present, for other legality checks.
5088 if Nkind (Prefix (N)) = N_Expanded_Name then
5090 Make_Expanded_Name (Sloc (N),
5092 Prefix => New_Copy (Prefix (Prefix (N))),
5093 Selector_Name => New_Reference_To (T, Sloc (N))));
5096 Rewrite (N, New_Reference_To (T, Sloc (N)));
5103 elsif Attribute_Name (N) = Name_Stub_Type then
5105 -- This is handled in Analyze_Attribute
5109 -- All other attributes are invalid in a subtype mark
5112 Error_Msg_N ("invalid attribute in subtype mark", N);
5118 if Is_Entity_Name (N) then
5119 T_Name := Entity (N);
5121 Error_Msg_N ("subtype mark required in this context", N);
5122 Set_Etype (N, Any_Type);
5126 if T_Name = Any_Id or else Etype (N) = Any_Type then
5128 -- Undefined id. Make it into a valid type
5130 Set_Entity (N, Any_Type);
5132 elsif not Is_Type (T_Name)
5133 and then T_Name /= Standard_Void_Type
5135 Error_Msg_Sloc := Sloc (T_Name);
5136 Error_Msg_N ("subtype mark required in this context", N);
5137 Error_Msg_NE ("\\found & declared#", N, T_Name);
5138 Set_Entity (N, Any_Type);
5141 -- If the type is an incomplete type created to handle
5142 -- anonymous access components of a record type, then the
5143 -- incomplete type is the visible entity and subsequent
5144 -- references will point to it. Mark the original full
5145 -- type as referenced, to prevent spurious warnings.
5147 if Is_Incomplete_Type (T_Name)
5148 and then Present (Full_View (T_Name))
5149 and then not Comes_From_Source (T_Name)
5151 Set_Referenced (Full_View (T_Name));
5154 T_Name := Get_Full_View (T_Name);
5156 -- Ada 2005 (AI-251, AI-50217): Handle interfaces visible through
5157 -- limited-with clauses
5159 if From_With_Type (T_Name)
5160 and then Ekind (T_Name) in Incomplete_Kind
5161 and then Present (Non_Limited_View (T_Name))
5162 and then Is_Interface (Non_Limited_View (T_Name))
5164 T_Name := Non_Limited_View (T_Name);
5167 if In_Open_Scopes (T_Name) then
5168 if Ekind (Base_Type (T_Name)) = E_Task_Type then
5170 -- In Ada 2005, a task name can be used in an access
5171 -- definition within its own body.
5173 if Ada_Version >= Ada_05
5174 and then Nkind (Parent (N)) = N_Access_Definition
5176 Set_Entity (N, T_Name);
5177 Set_Etype (N, T_Name);
5182 ("task type cannot be used as type mark " &
5183 "within its own spec or body", N);
5186 elsif Ekind (Base_Type (T_Name)) = E_Protected_Type then
5188 -- In Ada 2005, a protected name can be used in an access
5189 -- definition within its own body.
5191 if Ada_Version >= Ada_05
5192 and then Nkind (Parent (N)) = N_Access_Definition
5194 Set_Entity (N, T_Name);
5195 Set_Etype (N, T_Name);
5200 ("protected type cannot be used as type mark " &
5201 "within its own spec or body", N);
5205 Error_Msg_N ("type declaration cannot refer to itself", N);
5208 Set_Etype (N, Any_Type);
5209 Set_Entity (N, Any_Type);
5210 Set_Error_Posted (T_Name);
5214 Set_Entity (N, T_Name);
5215 Set_Etype (N, T_Name);
5219 if Present (Etype (N)) and then Comes_From_Source (N) then
5220 if Is_Fixed_Point_Type (Etype (N)) then
5221 Check_Restriction (No_Fixed_Point, N);
5222 elsif Is_Floating_Point_Type (Etype (N)) then
5223 Check_Restriction (No_Floating_Point, N);
5228 ------------------------------------
5229 -- Has_Implicit_Character_Literal --
5230 ------------------------------------
5232 function Has_Implicit_Character_Literal (N : Node_Id) return Boolean is
5234 Found : Boolean := False;
5235 P : constant Entity_Id := Entity (Prefix (N));
5236 Priv_Id : Entity_Id := Empty;
5239 if Ekind (P) = E_Package
5240 and then not In_Open_Scopes (P)
5242 Priv_Id := First_Private_Entity (P);
5245 if P = Standard_Standard then
5246 Change_Selected_Component_To_Expanded_Name (N);
5247 Rewrite (N, Selector_Name (N));
5249 Set_Etype (Original_Node (N), Standard_Character);
5253 Id := First_Entity (P);
5256 and then Id /= Priv_Id
5258 if Is_Character_Type (Id)
5259 and then (Root_Type (Id) = Standard_Character
5260 or else Root_Type (Id) = Standard_Wide_Character
5261 or else Root_Type (Id) = Standard_Wide_Wide_Character)
5262 and then Id = Base_Type (Id)
5264 -- We replace the node with the literal itself, resolve as a
5265 -- character, and set the type correctly.
5268 Change_Selected_Component_To_Expanded_Name (N);
5269 Rewrite (N, Selector_Name (N));
5272 Set_Etype (Original_Node (N), Id);
5276 -- More than one type derived from Character in given scope.
5277 -- Collect all possible interpretations.
5279 Add_One_Interp (N, Id, Id);
5287 end Has_Implicit_Character_Literal;
5289 ----------------------
5290 -- Has_Private_With --
5291 ----------------------
5293 function Has_Private_With (E : Entity_Id) return Boolean is
5294 Comp_Unit : constant Node_Id := Cunit (Current_Sem_Unit);
5298 Item := First (Context_Items (Comp_Unit));
5299 while Present (Item) loop
5300 if Nkind (Item) = N_With_Clause
5301 and then Private_Present (Item)
5302 and then Entity (Name (Item)) = E
5311 end Has_Private_With;
5313 ---------------------------
5314 -- Has_Implicit_Operator --
5315 ---------------------------
5317 function Has_Implicit_Operator (N : Node_Id) return Boolean is
5318 Op_Id : constant Name_Id := Chars (Selector_Name (N));
5319 P : constant Entity_Id := Entity (Prefix (N));
5321 Priv_Id : Entity_Id := Empty;
5323 procedure Add_Implicit_Operator
5325 Op_Type : Entity_Id := Empty);
5326 -- Add implicit interpretation to node N, using the type for which a
5327 -- predefined operator exists. If the operator yields a boolean type,
5328 -- the Operand_Type is implicitly referenced by the operator, and a
5329 -- reference to it must be generated.
5331 ---------------------------
5332 -- Add_Implicit_Operator --
5333 ---------------------------
5335 procedure Add_Implicit_Operator
5337 Op_Type : Entity_Id := Empty)
5339 Predef_Op : Entity_Id;
5342 Predef_Op := Current_Entity (Selector_Name (N));
5344 while Present (Predef_Op)
5345 and then Scope (Predef_Op) /= Standard_Standard
5347 Predef_Op := Homonym (Predef_Op);
5350 if Nkind (N) = N_Selected_Component then
5351 Change_Selected_Component_To_Expanded_Name (N);
5354 Add_One_Interp (N, Predef_Op, T);
5356 -- For operators with unary and binary interpretations, add both
5358 if Present (Homonym (Predef_Op)) then
5359 Add_One_Interp (N, Homonym (Predef_Op), T);
5362 -- The node is a reference to a predefined operator, and
5363 -- an implicit reference to the type of its operands.
5365 if Present (Op_Type) then
5366 Generate_Operator_Reference (N, Op_Type);
5368 Generate_Operator_Reference (N, T);
5370 end Add_Implicit_Operator;
5372 -- Start of processing for Has_Implicit_Operator
5375 if Ekind (P) = E_Package
5376 and then not In_Open_Scopes (P)
5378 Priv_Id := First_Private_Entity (P);
5381 Id := First_Entity (P);
5385 -- Boolean operators: an implicit declaration exists if the scope
5386 -- contains a declaration for a derived Boolean type, or for an
5387 -- array of Boolean type.
5389 when Name_Op_And | Name_Op_Not | Name_Op_Or | Name_Op_Xor =>
5390 while Id /= Priv_Id loop
5391 if Valid_Boolean_Arg (Id)
5392 and then Id = Base_Type (Id)
5394 Add_Implicit_Operator (Id);
5401 -- Equality: look for any non-limited type (result is Boolean)
5403 when Name_Op_Eq | Name_Op_Ne =>
5404 while Id /= Priv_Id loop
5406 and then not Is_Limited_Type (Id)
5407 and then Id = Base_Type (Id)
5409 Add_Implicit_Operator (Standard_Boolean, Id);
5416 -- Comparison operators: scalar type, or array of scalar
5418 when Name_Op_Lt | Name_Op_Le | Name_Op_Gt | Name_Op_Ge =>
5419 while Id /= Priv_Id loop
5420 if (Is_Scalar_Type (Id)
5421 or else (Is_Array_Type (Id)
5422 and then Is_Scalar_Type (Component_Type (Id))))
5423 and then Id = Base_Type (Id)
5425 Add_Implicit_Operator (Standard_Boolean, Id);
5432 -- Arithmetic operators: any numeric type
5442 while Id /= Priv_Id loop
5443 if Is_Numeric_Type (Id)
5444 and then Id = Base_Type (Id)
5446 Add_Implicit_Operator (Id);
5453 -- Concatenation: any one-dimensional array type
5455 when Name_Op_Concat =>
5456 while Id /= Priv_Id loop
5457 if Is_Array_Type (Id) and then Number_Dimensions (Id) = 1
5458 and then Id = Base_Type (Id)
5460 Add_Implicit_Operator (Id);
5467 -- What is the others condition here? Should we be using a
5468 -- subtype of Name_Id that would restrict to operators ???
5470 when others => null;
5473 -- If we fall through, then we do not have an implicit operator
5477 end Has_Implicit_Operator;
5479 --------------------
5480 -- In_Open_Scopes --
5481 --------------------
5483 function In_Open_Scopes (S : Entity_Id) return Boolean is
5485 -- Several scope stacks are maintained by Scope_Stack. The base of the
5486 -- currently active scope stack is denoted by the Is_Active_Stack_Base
5487 -- flag in the scope stack entry. Note that the scope stacks used to
5488 -- simply be delimited implicitly by the presence of Standard_Standard
5489 -- at their base, but there now are cases where this is not sufficient
5490 -- because Standard_Standard actually may appear in the middle of the
5491 -- active set of scopes.
5493 for J in reverse 0 .. Scope_Stack.Last loop
5494 if Scope_Stack.Table (J).Entity = S then
5498 -- Check Is_Active_Stack_Base to tell us when to stop, as there are
5499 -- cases where Standard_Standard appears in the middle of the active
5500 -- set of scopes. This affects the declaration and overriding of
5501 -- private inherited operations in instantiations of generic child
5504 exit when Scope_Stack.Table (J).Is_Active_Stack_Base;
5510 -----------------------------
5511 -- Inherit_Renamed_Profile --
5512 -----------------------------
5514 procedure Inherit_Renamed_Profile (New_S : Entity_Id; Old_S : Entity_Id) is
5521 if Ekind (Old_S) = E_Operator then
5522 New_F := First_Formal (New_S);
5524 while Present (New_F) loop
5525 Set_Etype (New_F, Base_Type (Etype (New_F)));
5526 Next_Formal (New_F);
5529 Set_Etype (New_S, Base_Type (Etype (New_S)));
5532 New_F := First_Formal (New_S);
5533 Old_F := First_Formal (Old_S);
5535 while Present (New_F) loop
5536 New_T := Etype (New_F);
5537 Old_T := Etype (Old_F);
5539 -- If the new type is a renaming of the old one, as is the
5540 -- case for actuals in instances, retain its name, to simplify
5541 -- later disambiguation.
5543 if Nkind (Parent (New_T)) = N_Subtype_Declaration
5544 and then Is_Entity_Name (Subtype_Indication (Parent (New_T)))
5545 and then Entity (Subtype_Indication (Parent (New_T))) = Old_T
5549 Set_Etype (New_F, Old_T);
5552 Next_Formal (New_F);
5553 Next_Formal (Old_F);
5556 if Ekind (Old_S) = E_Function
5557 or else Ekind (Old_S) = E_Enumeration_Literal
5559 Set_Etype (New_S, Etype (Old_S));
5562 end Inherit_Renamed_Profile;
5568 procedure Initialize is
5573 -------------------------
5574 -- Install_Use_Clauses --
5575 -------------------------
5577 procedure Install_Use_Clauses
5579 Force_Installation : Boolean := False)
5587 while Present (U) loop
5589 -- Case of USE package
5591 if Nkind (U) = N_Use_Package_Clause then
5592 P := First (Names (U));
5593 while Present (P) loop
5596 if Ekind (Id) = E_Package then
5598 Note_Redundant_Use (P);
5600 elsif Present (Renamed_Object (Id))
5601 and then In_Use (Renamed_Object (Id))
5603 Note_Redundant_Use (P);
5605 elsif Force_Installation or else Applicable_Use (P) then
5606 Use_One_Package (Id, U);
5617 P := First (Subtype_Marks (U));
5618 while Present (P) loop
5619 if not Is_Entity_Name (P)
5620 or else No (Entity (P))
5624 elsif Entity (P) /= Any_Type then
5632 Next_Use_Clause (U);
5634 end Install_Use_Clauses;
5636 -------------------------------------
5637 -- Is_Appropriate_For_Entry_Prefix --
5638 -------------------------------------
5640 function Is_Appropriate_For_Entry_Prefix (T : Entity_Id) return Boolean is
5641 P_Type : Entity_Id := T;
5644 if Is_Access_Type (P_Type) then
5645 P_Type := Designated_Type (P_Type);
5648 return Is_Task_Type (P_Type) or else Is_Protected_Type (P_Type);
5649 end Is_Appropriate_For_Entry_Prefix;
5651 -------------------------------
5652 -- Is_Appropriate_For_Record --
5653 -------------------------------
5655 function Is_Appropriate_For_Record (T : Entity_Id) return Boolean is
5657 function Has_Components (T1 : Entity_Id) return Boolean;
5658 -- Determine if given type has components (i.e. is either a record
5659 -- type or a type that has discriminants).
5661 --------------------
5662 -- Has_Components --
5663 --------------------
5665 function Has_Components (T1 : Entity_Id) return Boolean is
5667 return Is_Record_Type (T1)
5668 or else (Is_Private_Type (T1) and then Has_Discriminants (T1))
5669 or else (Is_Task_Type (T1) and then Has_Discriminants (T1))
5670 or else (Is_Incomplete_Type (T1)
5671 and then From_With_Type (T1)
5672 and then Present (Non_Limited_View (T1))
5673 and then Is_Record_Type
5674 (Get_Full_View (Non_Limited_View (T1))));
5677 -- Start of processing for Is_Appropriate_For_Record
5682 and then (Has_Components (T)
5683 or else (Is_Access_Type (T)
5684 and then Has_Components (Designated_Type (T))));
5685 end Is_Appropriate_For_Record;
5687 ------------------------
5688 -- Note_Redundant_Use --
5689 ------------------------
5691 procedure Note_Redundant_Use (Clause : Node_Id) is
5692 Pack_Name : constant Entity_Id := Entity (Clause);
5693 Cur_Use : constant Node_Id := Current_Use_Clause (Pack_Name);
5694 Decl : constant Node_Id := Parent (Clause);
5696 Prev_Use : Node_Id := Empty;
5697 Redundant : Node_Id := Empty;
5698 -- The Use_Clause which is actually redundant. In the simplest case
5699 -- it is Pack itself, but when we compile a body we install its
5700 -- context before that of its spec, in which case it is the use_clause
5701 -- in the spec that will appear to be redundant, and we want the
5702 -- warning to be placed on the body. Similar complications appear when
5703 -- the redundancy is between a child unit and one of its ancestors.
5706 Set_Redundant_Use (Clause, True);
5708 if not Comes_From_Source (Clause)
5710 or else not Warn_On_Redundant_Constructs
5715 if not Is_Compilation_Unit (Current_Scope) then
5717 -- If the use_clause is in an inner scope, it is made redundant
5718 -- by some clause in the current context, with one exception:
5719 -- If we're compiling a nested package body, and the use_clause
5720 -- comes from the corresponding spec, the clause is not necessarily
5721 -- fully redundant, so we should not warn. If a warning was
5722 -- warranted, it would have been given when the spec was processed.
5724 if Nkind (Parent (Decl)) = N_Package_Specification then
5726 Package_Spec_Entity : constant Entity_Id :=
5727 Defining_Unit_Name (Parent (Decl));
5729 if In_Package_Body (Package_Spec_Entity) then
5735 Redundant := Clause;
5736 Prev_Use := Cur_Use;
5738 elsif Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Body then
5740 Cur_Unit : constant Unit_Number_Type := Get_Source_Unit (Cur_Use);
5741 New_Unit : constant Unit_Number_Type := Get_Source_Unit (Clause);
5745 if Cur_Unit = New_Unit then
5747 -- Redundant clause in same body
5749 Redundant := Clause;
5750 Prev_Use := Cur_Use;
5752 elsif Cur_Unit = Current_Sem_Unit then
5754 -- If the new clause is not in the current unit it has been
5755 -- analyzed first, and it makes the other one redundant.
5756 -- However, if the new clause appears in a subunit, Cur_Unit
5757 -- is still the parent, and in that case the redundant one
5758 -- is the one appearing in the subunit.
5760 if Nkind (Unit (Cunit (New_Unit))) = N_Subunit then
5761 Redundant := Clause;
5762 Prev_Use := Cur_Use;
5764 -- Most common case: redundant clause in body,
5765 -- original clause in spec. Current scope is spec entity.
5770 Unit (Library_Unit (Cunit (Current_Sem_Unit))))
5772 Redundant := Cur_Use;
5776 -- The new clause may appear in an unrelated unit, when
5777 -- the parents of a generic are being installed prior to
5778 -- instantiation. In this case there must be no warning.
5779 -- We detect this case by checking whether the current top
5780 -- of the stack is related to the current compilation.
5782 Scop := Current_Scope;
5783 while Present (Scop)
5784 and then Scop /= Standard_Standard
5786 if Is_Compilation_Unit (Scop)
5787 and then not Is_Child_Unit (Scop)
5791 elsif Scop = Cunit_Entity (Current_Sem_Unit) then
5795 Scop := Scope (Scop);
5798 Redundant := Cur_Use;
5802 elsif New_Unit = Current_Sem_Unit then
5803 Redundant := Clause;
5804 Prev_Use := Cur_Use;
5807 -- Neither is the current unit, so they appear in parent or
5808 -- sibling units. Warning will be emitted elsewhere.
5814 elsif Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Declaration
5815 and then Present (Parent_Spec (Unit (Cunit (Current_Sem_Unit))))
5817 -- Use_clause is in child unit of current unit, and the child
5818 -- unit appears in the context of the body of the parent, so it
5819 -- has been installed first, even though it is the redundant one.
5820 -- Depending on their placement in the context, the visible or the
5821 -- private parts of the two units, either might appear as redundant,
5822 -- but the message has to be on the current unit.
5824 if Get_Source_Unit (Cur_Use) = Current_Sem_Unit then
5825 Redundant := Cur_Use;
5828 Redundant := Clause;
5829 Prev_Use := Cur_Use;
5832 -- If the new use clause appears in the private part of a parent unit
5833 -- it may appear to be redudant w.r.t. a use clause in a child unit,
5834 -- but the previous use clause was needed in the visible part of the
5835 -- child, and no warning should be emitted.
5837 if Nkind (Parent (Decl)) = N_Package_Specification
5839 List_Containing (Decl) = Private_Declarations (Parent (Decl))
5842 Par : constant Entity_Id := Defining_Entity (Parent (Decl));
5843 Spec : constant Node_Id :=
5844 Specification (Unit (Cunit (Current_Sem_Unit)));
5847 if Is_Compilation_Unit (Par)
5848 and then Par /= Cunit_Entity (Current_Sem_Unit)
5849 and then Parent (Cur_Use) = Spec
5851 List_Containing (Cur_Use) = Visible_Declarations (Spec)
5862 if Present (Redundant) then
5863 Error_Msg_Sloc := Sloc (Prev_Use);
5865 "& is already use_visible through declaration #?",
5866 Redundant, Pack_Name);
5868 end Note_Redundant_Use;
5874 procedure Pop_Scope is
5875 SST : Scope_Stack_Entry renames Scope_Stack.Table (Scope_Stack.Last);
5878 if Debug_Flag_E then
5882 Scope_Suppress := SST.Save_Scope_Suppress;
5883 Local_Suppress_Stack_Top := SST.Save_Local_Suppress_Stack_Top;
5885 if Debug_Flag_W then
5886 Write_Str ("--> exiting scope: ");
5887 Write_Name (Chars (Current_Scope));
5888 Write_Str (", Depth=");
5889 Write_Int (Int (Scope_Stack.Last));
5893 End_Use_Clauses (SST.First_Use_Clause);
5895 -- If the actions to be wrapped are still there they will get lost
5896 -- causing incomplete code to be generated. It is better to abort in
5897 -- this case (and we do the abort even with assertions off since the
5898 -- penalty is incorrect code generation)
5900 if SST.Actions_To_Be_Wrapped_Before /= No_List
5902 SST.Actions_To_Be_Wrapped_After /= No_List
5907 -- Free last subprogram name if allocated, and pop scope
5909 Free (SST.Last_Subprogram_Name);
5910 Scope_Stack.Decrement_Last;
5917 procedure Push_Scope (S : Entity_Id) is
5921 if Ekind (S) = E_Void then
5924 -- Set scope depth if not a non-concurrent type, and we have not
5925 -- yet set the scope depth. This means that we have the first
5926 -- occurrence of the scope, and this is where the depth is set.
5928 elsif (not Is_Type (S) or else Is_Concurrent_Type (S))
5929 and then not Scope_Depth_Set (S)
5931 if S = Standard_Standard then
5932 Set_Scope_Depth_Value (S, Uint_0);
5934 elsif Is_Child_Unit (S) then
5935 Set_Scope_Depth_Value (S, Uint_1);
5937 elsif not Is_Record_Type (Current_Scope) then
5938 if Ekind (S) = E_Loop then
5939 Set_Scope_Depth_Value (S, Scope_Depth (Current_Scope));
5941 Set_Scope_Depth_Value (S, Scope_Depth (Current_Scope) + 1);
5946 Scope_Stack.Increment_Last;
5949 SST : Scope_Stack_Entry renames Scope_Stack.Table (Scope_Stack.Last);
5953 SST.Save_Scope_Suppress := Scope_Suppress;
5954 SST.Save_Local_Suppress_Stack_Top := Local_Suppress_Stack_Top;
5956 if Scope_Stack.Last > Scope_Stack.First then
5957 SST.Component_Alignment_Default := Scope_Stack.Table
5958 (Scope_Stack.Last - 1).
5959 Component_Alignment_Default;
5962 SST.Last_Subprogram_Name := null;
5963 SST.Is_Transient := False;
5964 SST.Node_To_Be_Wrapped := Empty;
5965 SST.Pending_Freeze_Actions := No_List;
5966 SST.Actions_To_Be_Wrapped_Before := No_List;
5967 SST.Actions_To_Be_Wrapped_After := No_List;
5968 SST.First_Use_Clause := Empty;
5969 SST.Is_Active_Stack_Base := False;
5970 SST.Previous_Visibility := False;
5973 if Debug_Flag_W then
5974 Write_Str ("--> new scope: ");
5975 Write_Name (Chars (Current_Scope));
5976 Write_Str (", Id=");
5977 Write_Int (Int (Current_Scope));
5978 Write_Str (", Depth=");
5979 Write_Int (Int (Scope_Stack.Last));
5983 -- Deal with copying flags from the previous scope to this one. This
5984 -- is not necessary if either scope is standard, or if the new scope
5987 if S /= Standard_Standard
5988 and then Scope (S) /= Standard_Standard
5989 and then not Is_Child_Unit (S)
5993 if Nkind (E) not in N_Entity then
5997 -- Copy categorization flags from Scope (S) to S, this is not done
5998 -- when Scope (S) is Standard_Standard since propagation is from
5999 -- library unit entity inwards. Copy other relevant attributes as
6000 -- well (Discard_Names in particular).
6002 -- We only propagate inwards for library level entities,
6003 -- inner level subprograms do not inherit the categorization.
6005 if Is_Library_Level_Entity (S) then
6006 Set_Is_Preelaborated (S, Is_Preelaborated (E));
6007 Set_Is_Shared_Passive (S, Is_Shared_Passive (E));
6008 Set_Discard_Names (S, Discard_Names (E));
6009 Set_Suppress_Value_Tracking_On_Call
6010 (S, Suppress_Value_Tracking_On_Call (E));
6011 Set_Categorization_From_Scope (E => S, Scop => E);
6016 ---------------------
6017 -- Premature_Usage --
6018 ---------------------
6020 procedure Premature_Usage (N : Node_Id) is
6021 Kind : constant Node_Kind := Nkind (Parent (Entity (N)));
6022 E : Entity_Id := Entity (N);
6025 -- Within an instance, the analysis of the actual for a formal object
6026 -- does not see the name of the object itself. This is significant only
6027 -- if the object is an aggregate, where its analysis does not do any
6028 -- name resolution on component associations. (see 4717-008). In such a
6029 -- case, look for the visible homonym on the chain.
6032 and then Present (Homonym (E))
6037 and then not In_Open_Scopes (Scope (E))
6044 Set_Etype (N, Etype (E));
6049 if Kind = N_Component_Declaration then
6051 ("component&! cannot be used before end of record declaration", N);
6053 elsif Kind = N_Parameter_Specification then
6055 ("formal parameter&! cannot be used before end of specification",
6058 elsif Kind = N_Discriminant_Specification then
6060 ("discriminant&! cannot be used before end of discriminant part",
6063 elsif Kind = N_Procedure_Specification
6064 or else Kind = N_Function_Specification
6067 ("subprogram&! cannot be used before end of its declaration",
6071 ("object& cannot be used before end of its declaration!", N);
6073 end Premature_Usage;
6075 ------------------------
6076 -- Present_System_Aux --
6077 ------------------------
6079 function Present_System_Aux (N : Node_Id := Empty) return Boolean is
6081 Aux_Name : Unit_Name_Type;
6082 Unum : Unit_Number_Type;
6087 function Find_System (C_Unit : Node_Id) return Entity_Id;
6088 -- Scan context clause of compilation unit to find with_clause
6095 function Find_System (C_Unit : Node_Id) return Entity_Id is
6096 With_Clause : Node_Id;
6099 With_Clause := First (Context_Items (C_Unit));
6100 while Present (With_Clause) loop
6101 if (Nkind (With_Clause) = N_With_Clause
6102 and then Chars (Name (With_Clause)) = Name_System)
6103 and then Comes_From_Source (With_Clause)
6114 -- Start of processing for Present_System_Aux
6117 -- The child unit may have been loaded and analyzed already
6119 if Present (System_Aux_Id) then
6122 -- If no previous pragma for System.Aux, nothing to load
6124 elsif No (System_Extend_Unit) then
6127 -- Use the unit name given in the pragma to retrieve the unit.
6128 -- Verify that System itself appears in the context clause of the
6129 -- current compilation. If System is not present, an error will
6130 -- have been reported already.
6133 With_Sys := Find_System (Cunit (Current_Sem_Unit));
6135 The_Unit := Unit (Cunit (Current_Sem_Unit));
6138 and then (Nkind (The_Unit) = N_Package_Body
6139 or else (Nkind (The_Unit) = N_Subprogram_Body
6140 and then not Acts_As_Spec (Cunit (Current_Sem_Unit))))
6142 With_Sys := Find_System (Library_Unit (Cunit (Current_Sem_Unit)));
6146 and then Present (N)
6148 -- If we are compiling a subunit, we need to examine its
6149 -- context as well (Current_Sem_Unit is the parent unit);
6151 The_Unit := Parent (N);
6153 while Nkind (The_Unit) /= N_Compilation_Unit loop
6154 The_Unit := Parent (The_Unit);
6157 if Nkind (Unit (The_Unit)) = N_Subunit then
6158 With_Sys := Find_System (The_Unit);
6162 if No (With_Sys) then
6166 Loc := Sloc (With_Sys);
6167 Get_Name_String (Chars (Expression (System_Extend_Unit)));
6168 Name_Buffer (8 .. Name_Len + 7) := Name_Buffer (1 .. Name_Len);
6169 Name_Buffer (1 .. 7) := "system.";
6170 Name_Buffer (Name_Len + 8) := '%';
6171 Name_Buffer (Name_Len + 9) := 's';
6172 Name_Len := Name_Len + 9;
6173 Aux_Name := Name_Find;
6177 (Load_Name => Aux_Name,
6180 Error_Node => With_Sys);
6182 if Unum /= No_Unit then
6183 Semantics (Cunit (Unum));
6185 Defining_Entity (Specification (Unit (Cunit (Unum))));
6188 Make_With_Clause (Loc,
6190 Make_Expanded_Name (Loc,
6191 Chars => Chars (System_Aux_Id),
6192 Prefix => New_Reference_To (Scope (System_Aux_Id), Loc),
6193 Selector_Name => New_Reference_To (System_Aux_Id, Loc)));
6195 Set_Entity (Name (Withn), System_Aux_Id);
6197 Set_Library_Unit (Withn, Cunit (Unum));
6198 Set_Corresponding_Spec (Withn, System_Aux_Id);
6199 Set_First_Name (Withn, True);
6200 Set_Implicit_With (Withn, True);
6202 Insert_After (With_Sys, Withn);
6203 Mark_Rewrite_Insertion (Withn);
6204 Set_Context_Installed (Withn);
6208 -- Here if unit load failed
6211 Error_Msg_Name_1 := Name_System;
6212 Error_Msg_Name_2 := Chars (Expression (System_Extend_Unit));
6214 ("extension package `%.%` does not exist",
6215 Opt.System_Extend_Unit);
6219 end Present_System_Aux;
6221 -------------------------
6222 -- Restore_Scope_Stack --
6223 -------------------------
6225 procedure Restore_Scope_Stack (Handle_Use : Boolean := True) is
6228 Comp_Unit : Node_Id;
6229 In_Child : Boolean := False;
6230 Full_Vis : Boolean := True;
6231 SS_Last : constant Int := Scope_Stack.Last;
6234 -- Restore visibility of previous scope stack, if any
6236 for J in reverse 0 .. Scope_Stack.Last loop
6237 exit when Scope_Stack.Table (J).Entity = Standard_Standard
6238 or else No (Scope_Stack.Table (J).Entity);
6240 S := Scope_Stack.Table (J).Entity;
6242 if not Is_Hidden_Open_Scope (S) then
6244 -- If the parent scope is hidden, its entities are hidden as
6245 -- well, unless the entity is the instantiation currently
6248 if not Is_Hidden_Open_Scope (Scope (S))
6249 or else not Analyzed (Parent (S))
6250 or else Scope (S) = Standard_Standard
6252 Set_Is_Immediately_Visible (S, True);
6255 E := First_Entity (S);
6256 while Present (E) loop
6257 if Is_Child_Unit (E) then
6258 Set_Is_Immediately_Visible (E,
6259 Is_Visible_Child_Unit (E) or else In_Open_Scopes (E));
6261 Set_Is_Immediately_Visible (E, True);
6266 if not Full_Vis then
6267 exit when E = First_Private_Entity (S);
6271 -- The visibility of child units (siblings of current compilation)
6272 -- must be restored in any case. Their declarations may appear
6273 -- after the private part of the parent.
6275 if not Full_Vis then
6276 while Present (E) loop
6277 if Is_Child_Unit (E) then
6278 Set_Is_Immediately_Visible (E,
6279 Is_Visible_Child_Unit (E) or else In_Open_Scopes (E));
6287 if Is_Child_Unit (S)
6288 and not In_Child -- check only for current unit
6292 -- Restore visibility of parents according to whether the child
6293 -- is private and whether we are in its visible part.
6295 Comp_Unit := Parent (Unit_Declaration_Node (S));
6297 if Nkind (Comp_Unit) = N_Compilation_Unit
6298 and then Private_Present (Comp_Unit)
6302 elsif (Ekind (S) = E_Package
6303 or else Ekind (S) = E_Generic_Package)
6304 and then (In_Private_Part (S)
6305 or else In_Package_Body (S))
6309 elsif (Ekind (S) = E_Procedure
6310 or else Ekind (S) = E_Function)
6311 and then Has_Completion (S)
6322 if SS_Last >= Scope_Stack.First
6323 and then Scope_Stack.Table (SS_Last).Entity /= Standard_Standard
6326 Install_Use_Clauses (Scope_Stack.Table (SS_Last).First_Use_Clause);
6328 end Restore_Scope_Stack;
6330 ----------------------
6331 -- Save_Scope_Stack --
6332 ----------------------
6334 procedure Save_Scope_Stack (Handle_Use : Boolean := True) is
6337 SS_Last : constant Int := Scope_Stack.Last;
6340 if SS_Last >= Scope_Stack.First
6341 and then Scope_Stack.Table (SS_Last).Entity /= Standard_Standard
6344 End_Use_Clauses (Scope_Stack.Table (SS_Last).First_Use_Clause);
6347 -- If the call is from within a compilation unit, as when called from
6348 -- Rtsfind, make current entries in scope stack invisible while we
6349 -- analyze the new unit.
6351 for J in reverse 0 .. SS_Last loop
6352 exit when Scope_Stack.Table (J).Entity = Standard_Standard
6353 or else No (Scope_Stack.Table (J).Entity);
6355 S := Scope_Stack.Table (J).Entity;
6356 Set_Is_Immediately_Visible (S, False);
6358 E := First_Entity (S);
6359 while Present (E) loop
6360 Set_Is_Immediately_Visible (E, False);
6366 end Save_Scope_Stack;
6372 procedure Set_Use (L : List_Id) is
6374 Pack_Name : Node_Id;
6381 while Present (Decl) loop
6382 if Nkind (Decl) = N_Use_Package_Clause then
6383 Chain_Use_Clause (Decl);
6385 Pack_Name := First (Names (Decl));
6386 while Present (Pack_Name) loop
6387 Pack := Entity (Pack_Name);
6389 if Ekind (Pack) = E_Package
6390 and then Applicable_Use (Pack_Name)
6392 Use_One_Package (Pack, Decl);
6398 elsif Nkind (Decl) = N_Use_Type_Clause then
6399 Chain_Use_Clause (Decl);
6401 Id := First (Subtype_Marks (Decl));
6402 while Present (Id) loop
6403 if Entity (Id) /= Any_Type then
6416 ---------------------
6417 -- Use_One_Package --
6418 ---------------------
6420 procedure Use_One_Package (P : Entity_Id; N : Node_Id) is
6423 Current_Instance : Entity_Id := Empty;
6425 Private_With_OK : Boolean := False;
6428 if Ekind (P) /= E_Package then
6433 Set_Current_Use_Clause (P, N);
6435 -- Ada 2005 (AI-50217): Check restriction
6437 if From_With_Type (P) then
6438 Error_Msg_N ("limited withed package cannot appear in use clause", N);
6441 -- Find enclosing instance, if any
6444 Current_Instance := Current_Scope;
6445 while not Is_Generic_Instance (Current_Instance) loop
6446 Current_Instance := Scope (Current_Instance);
6449 if No (Hidden_By_Use_Clause (N)) then
6450 Set_Hidden_By_Use_Clause (N, New_Elmt_List);
6454 -- If unit is a package renaming, indicate that the renamed
6455 -- package is also in use (the flags on both entities must
6456 -- remain consistent, and a subsequent use of either of them
6457 -- should be recognized as redundant).
6459 if Present (Renamed_Object (P)) then
6460 Set_In_Use (Renamed_Object (P));
6461 Set_Current_Use_Clause (Renamed_Object (P), N);
6462 Real_P := Renamed_Object (P);
6467 -- Ada 2005 (AI-262): Check the use_clause of a private withed package
6468 -- found in the private part of a package specification
6470 if In_Private_Part (Current_Scope)
6471 and then Has_Private_With (P)
6472 and then Is_Child_Unit (Current_Scope)
6473 and then Is_Child_Unit (P)
6474 and then Is_Ancestor_Package (Scope (Current_Scope), P)
6476 Private_With_OK := True;
6479 -- Loop through entities in one package making them potentially
6482 Id := First_Entity (P);
6484 and then (Id /= First_Private_Entity (P)
6485 or else Private_With_OK) -- Ada 2005 (AI-262)
6487 Prev := Current_Entity (Id);
6488 while Present (Prev) loop
6489 if Is_Immediately_Visible (Prev)
6490 and then (not Is_Overloadable (Prev)
6491 or else not Is_Overloadable (Id)
6492 or else (Type_Conformant (Id, Prev)))
6494 if No (Current_Instance) then
6496 -- Potentially use-visible entity remains hidden
6498 goto Next_Usable_Entity;
6500 -- A use clause within an instance hides outer global entities,
6501 -- which are not used to resolve local entities in the
6502 -- instance. Note that the predefined entities in Standard
6503 -- could not have been hidden in the generic by a use clause,
6504 -- and therefore remain visible. Other compilation units whose
6505 -- entities appear in Standard must be hidden in an instance.
6507 -- To determine whether an entity is external to the instance
6508 -- we compare the scope depth of its scope with that of the
6509 -- current instance. However, a generic actual of a subprogram
6510 -- instance is declared in the wrapper package but will not be
6511 -- hidden by a use-visible entity.
6513 -- If Id is called Standard, the predefined package with the
6514 -- same name is in the homonym chain. It has to be ignored
6515 -- because it has no defined scope (being the only entity in
6516 -- the system with this mandated behavior).
6518 elsif not Is_Hidden (Id)
6519 and then Present (Scope (Prev))
6520 and then not Is_Wrapper_Package (Scope (Prev))
6521 and then Scope_Depth (Scope (Prev)) <
6522 Scope_Depth (Current_Instance)
6523 and then (Scope (Prev) /= Standard_Standard
6524 or else Sloc (Prev) > Standard_Location)
6526 Set_Is_Potentially_Use_Visible (Id);
6527 Set_Is_Immediately_Visible (Prev, False);
6528 Append_Elmt (Prev, Hidden_By_Use_Clause (N));
6531 -- A user-defined operator is not use-visible if the predefined
6532 -- operator for the type is immediately visible, which is the case
6533 -- if the type of the operand is in an open scope. This does not
6534 -- apply to user-defined operators that have operands of different
6535 -- types, because the predefined mixed mode operations (multiply
6536 -- and divide) apply to universal types and do not hide anything.
6538 elsif Ekind (Prev) = E_Operator
6539 and then Operator_Matches_Spec (Prev, Id)
6540 and then In_Open_Scopes
6541 (Scope (Base_Type (Etype (First_Formal (Id)))))
6542 and then (No (Next_Formal (First_Formal (Id)))
6543 or else Etype (First_Formal (Id))
6544 = Etype (Next_Formal (First_Formal (Id)))
6545 or else Chars (Prev) = Name_Op_Expon)
6547 goto Next_Usable_Entity;
6550 Prev := Homonym (Prev);
6553 -- On exit, we know entity is not hidden, unless it is private
6555 if not Is_Hidden (Id)
6556 and then ((not Is_Child_Unit (Id))
6557 or else Is_Visible_Child_Unit (Id))
6559 Set_Is_Potentially_Use_Visible (Id);
6561 if Is_Private_Type (Id)
6562 and then Present (Full_View (Id))
6564 Set_Is_Potentially_Use_Visible (Full_View (Id));
6568 <<Next_Usable_Entity>>
6572 -- Child units are also made use-visible by a use clause, but they may
6573 -- appear after all visible declarations in the parent entity list.
6575 while Present (Id) loop
6576 if Is_Child_Unit (Id)
6577 and then Is_Visible_Child_Unit (Id)
6579 Set_Is_Potentially_Use_Visible (Id);
6585 if Chars (Real_P) = Name_System
6586 and then Scope (Real_P) = Standard_Standard
6587 and then Present_System_Aux (N)
6589 Use_One_Package (System_Aux_Id, N);
6592 end Use_One_Package;
6598 procedure Use_One_Type (Id : Node_Id) is
6604 -- It is the type determined by the subtype mark (8.4(8)) whose
6605 -- operations become potentially use-visible.
6607 T := Base_Type (Entity (Id));
6612 or else Is_Potentially_Use_Visible (T)
6613 or else In_Use (Scope (T)));
6615 if In_Open_Scopes (Scope (T)) then
6618 elsif From_With_Type (T) then
6620 ("incomplete type from limited view "
6621 & "cannot appear in use clause", Id);
6623 -- If the subtype mark designates a subtype in a different package,
6624 -- we have to check that the parent type is visible, otherwise the
6625 -- use type clause is a noop. Not clear how to do that???
6627 elsif not Redundant_Use (Id) then
6629 Op_List := Collect_Primitive_Operations (T);
6631 Elmt := First_Elmt (Op_List);
6632 while Present (Elmt) loop
6633 if (Nkind (Node (Elmt)) = N_Defining_Operator_Symbol
6634 or else Chars (Node (Elmt)) in Any_Operator_Name)
6635 and then not Is_Hidden (Node (Elmt))
6637 Set_Is_Potentially_Use_Visible (Node (Elmt));
6649 procedure Write_Info is
6650 Id : Entity_Id := First_Entity (Current_Scope);
6653 -- No point in dumping standard entities
6655 if Current_Scope = Standard_Standard then
6659 Write_Str ("========================================================");
6661 Write_Str (" Defined Entities in ");
6662 Write_Name (Chars (Current_Scope));
6664 Write_Str ("========================================================");
6668 Write_Str ("-- none --");
6672 while Present (Id) loop
6673 Write_Entity_Info (Id, " ");
6678 if Scope (Current_Scope) = Standard_Standard then
6680 -- Print information on the current unit itself
6682 Write_Entity_Info (Current_Scope, " ");
6692 procedure Write_Scopes is
6695 for J in reverse 1 .. Scope_Stack.Last loop
6696 S := Scope_Stack.Table (J).Entity;
6697 Write_Int (Int (S));
6698 Write_Str (" === ");
6699 Write_Name (Chars (S));
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