1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2005, 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 2, 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 COPYING. If not, write --
19 -- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, --
20 -- MA 02111-1307, USA. --
22 -- GNAT was originally developed by the GNAT team at New York University. --
23 -- Extensive contributions were provided by Ada Core Technologies Inc. --
25 ------------------------------------------------------------------------------
27 with Atree; use Atree;
28 with Debug; use Debug;
29 with Einfo; use Einfo;
30 with Elists; use Elists;
31 with Errout; use Errout;
32 with Exp_Tss; use Exp_Tss;
33 with Exp_Util; use Exp_Util;
34 with Fname; use Fname;
35 with Freeze; use Freeze;
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
233 -- stub, 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
239 -- of the subunit, but without reinitializing the names table, nor the
240 -- scope stack (i.e. standard is not pushed on the stack). In this fashion
241 -- the context of the subunit is added to the context of the parent, and
242 -- the subunit is compiled in the correct environment. Note that in the
243 -- course of processing the context of a subunit, Standard will appear
244 -- twice on the scope stack: once for the parent of the subunit, and
245 -- once for the unit in the context clause being compiled. However, the
246 -- two sets of entities are not linked by homonym chains, so that the
247 -- compilation of any context unit happens in a fresh visibility
250 -------------------------------
251 -- Processing of USE Clauses --
252 -------------------------------
254 -- Every defining occurrence has a flag indicating if it is potentially use
255 -- visible. Resolution of simple names examines this flag. The processing
256 -- of use clauses consists in setting this flag on all visible entities
257 -- defined in the corresponding package. On exit from the scope of the use
258 -- clause, the corresponding flag must be reset. However, a package may
259 -- appear in several nested use clauses (pathological but legal, alas!)
260 -- which forces us to use a slightly more involved scheme:
262 -- a) The defining occurrence for a package holds a flag -In_Use- to
263 -- indicate that it is currently in the scope of a use clause. If a
264 -- redundant use clause is encountered, then the corresponding occurrence
265 -- of the package name is flagged -Redundant_Use-.
267 -- b) On exit from a scope, the use clauses in its declarative part are
268 -- scanned. The visibility flag is reset in all entities declared in
269 -- package named in a use clause, as long as the package is not flagged
270 -- as being in a redundant use clause (in which case the outer use
271 -- clause is still in effect, and the direct visibility of its entities
272 -- must be retained).
274 -- Note that entities are not removed from their homonym chains on exit
275 -- from the package specification. A subsequent use clause does not need
276 -- to rechain the visible entities, but only to establish their direct
279 -----------------------------------
280 -- Handling private declarations --
281 -----------------------------------
283 -- The principle that each entity has a single defining occurrence clashes
284 -- with the presence of two separate definitions for private types: the
285 -- first is the private type declaration, and second is the full type
286 -- declaration. It is important that all references to the type point to
287 -- the same defining occurrence, namely the first one. To enforce the two
288 -- separate views of the entity, the corresponding information is swapped
289 -- between the two declarations. Outside of the package, the defining
290 -- occurrence only contains the private declaration information, while in
291 -- the private part and the body of the package the defining occurrence
292 -- contains the full declaration. To simplify the swap, the defining
293 -- occurrence that currently holds the private declaration points to the
294 -- full declaration. During semantic processing the defining occurrence
295 -- also points to a list of private dependents, that is to say access
296 -- types or composite types whose designated types or component types are
297 -- subtypes or derived types of the private type in question. After the
298 -- full declaration has been seen, the private dependents are updated to
299 -- indicate that they have full definitions.
301 ------------------------------------
302 -- Handling of Undefined Messages --
303 ------------------------------------
305 -- In normal mode, only the first use of an undefined identifier generates
306 -- a message. The table Urefs is used to record error messages that have
307 -- been issued so that second and subsequent ones do not generate further
308 -- messages. However, the second reference causes text to be added to the
309 -- original undefined message noting "(more references follow)". The
310 -- full error list option (-gnatf) forces messages to be generated for
311 -- every reference and disconnects the use of this table.
313 type Uref_Entry is record
315 -- Node for identifier for which original message was posted. The
316 -- Chars field of this identifier is used to detect later references
317 -- to the same identifier.
320 -- Records error message Id of original undefined message. Reset to
321 -- No_Error_Msg after the second occurrence, where it is used to add
322 -- text to the original message as described above.
325 -- Set if the message is not visible rather than undefined
328 -- Records location of error message. Used to make sure that we do
329 -- not consider a, b : undefined as two separate instances, which
330 -- would otherwise happen, since the parser converts this sequence
331 -- to a : undefined; b : undefined.
335 package Urefs is new Table.Table (
336 Table_Component_Type => Uref_Entry,
337 Table_Index_Type => Nat,
338 Table_Low_Bound => 1,
340 Table_Increment => 100,
341 Table_Name => "Urefs");
343 Candidate_Renaming : Entity_Id;
344 -- Holds a candidate interpretation that appears in a subprogram renaming
345 -- declaration and does not match the given specification, but matches at
346 -- least on the first formal. Allows better error message when given
347 -- specification omits defaulted parameters, a common error.
349 -----------------------
350 -- Local Subprograms --
351 -----------------------
353 procedure Analyze_Generic_Renaming
356 -- Common processing for all three kinds of generic renaming declarations.
357 -- Enter new name and indicate that it renames the generic unit.
359 procedure Analyze_Renamed_Character
363 -- Renamed entity is given by a character literal, which must belong
364 -- to the return type of the new entity. Is_Body indicates whether the
365 -- declaration is a renaming_as_body. If the original declaration has
366 -- already been frozen (because of an intervening body, e.g.) the body of
367 -- the function must be built now. The same applies to the following
368 -- various renaming procedures.
370 procedure Analyze_Renamed_Dereference
374 -- Renamed entity is given by an explicit dereference. Prefix must be a
375 -- conformant access_to_subprogram type.
377 procedure Analyze_Renamed_Entry
381 -- If the renamed entity in a subprogram renaming is an entry or protected
382 -- subprogram, build a body for the new entity whose only statement is a
383 -- call to the renamed entity.
385 procedure Analyze_Renamed_Family_Member
389 -- Used when the renamed entity is an indexed component. The prefix must
390 -- denote an entry family.
392 function Applicable_Use (Pack_Name : Node_Id) return Boolean;
393 -- Common code to Use_One_Package and Set_Use, to determine whether
394 -- use clause must be processed. Pack_Name is an entity name that
395 -- references the package in question.
397 procedure Attribute_Renaming (N : Node_Id);
398 -- Analyze renaming of attribute as function. The renaming declaration N
399 -- is rewritten as a function body that returns the attribute reference
400 -- applied to the formals of the function.
402 procedure Check_Frozen_Renaming (N : Node_Id; Subp : Entity_Id);
403 -- A renaming_as_body may occur after the entity of the original decla-
404 -- ration has been frozen. In that case, the body of the new entity must
405 -- be built now, because the usual mechanism of building the renamed
406 -- body at the point of freezing will not work. Subp is the subprogram
407 -- for which N provides the Renaming_As_Body.
409 procedure Check_In_Previous_With_Clause
412 -- N is a use_package clause and Nam the package name, or N is a use_type
413 -- clause and Nam is the prefix of the type name. In either case, verify
414 -- that the package is visible at that point in the context: either it
415 -- appears in a previous with_clause, or because it is a fully qualified
416 -- name and the root ancestor appears in a previous with_clause.
418 procedure Check_Library_Unit_Renaming (N : Node_Id; Old_E : Entity_Id);
419 -- Verify that the entity in a renaming declaration that is a library unit
420 -- is itself a library unit and not a nested unit or subunit. Also check
421 -- that if the renaming is a child unit of a generic parent, then the
422 -- renamed unit must also be a child unit of that parent. Finally, verify
423 -- that a renamed generic unit is not an implicit child declared within
424 -- an instance of the parent.
426 procedure Chain_Use_Clause (N : Node_Id);
427 -- Chain use clause onto list of uses clauses headed by First_Use_Clause
428 -- in the top scope table entry.
430 function Has_Implicit_Character_Literal (N : Node_Id) return Boolean;
431 -- Find a type derived from Character or Wide_Character in the prefix of N.
432 -- Used to resolved qualified names whose selector is a character literal.
434 function Has_Private_With (E : Entity_Id) return Boolean;
435 -- Ada 2005 (AI-262): Determines if the current compilation unit has a
438 procedure Find_Expanded_Name (N : Node_Id);
439 -- Selected component is known to be expanded name. Verify legality
440 -- of selector given the scope denoted by prefix.
442 function Find_Renamed_Entity
446 Is_Actual : Boolean := False) return Entity_Id;
447 -- Find the renamed entity that corresponds to the given parameter profile
448 -- in a subprogram renaming declaration. The renamed entity may be an
449 -- operator, a subprogram, an entry, or a protected operation. Is_Actual
450 -- indicates that the renaming is the one generated for an actual subpro-
451 -- gram in an instance, for which special visibility checks apply.
453 function Has_Implicit_Operator (N : Node_Id) return Boolean;
454 -- N is an expanded name whose selector is an operator name (eg P."+").
455 -- A declarative part contains an implicit declaration of an operator
456 -- if it has a declaration of a type to which one of the predefined
457 -- operators apply. The existence of this routine is an artifact of
458 -- our implementation: a more straightforward but more space-consuming
459 -- choice would be to make all inherited operators explicit in the
462 procedure Inherit_Renamed_Profile (New_S : Entity_Id; Old_S : Entity_Id);
463 -- A subprogram defined by a renaming declaration inherits the parameter
464 -- profile of the renamed entity. The subtypes given in the subprogram
465 -- specification are discarded and replaced with those of the renamed
466 -- subprogram, which are then used to recheck the default values.
468 function Is_Appropriate_For_Record (T : Entity_Id) return Boolean;
469 -- Prefix is appropriate for record if it is of a record type, or
470 -- an access to such.
472 function Is_Appropriate_For_Entry_Prefix (T : Entity_Id) return Boolean;
473 -- True if it is of a task type, a protected type, or else an access
474 -- to one of these types.
476 procedure Premature_Usage (N : Node_Id);
477 -- Diagnose usage of an entity before it is visible
479 procedure Use_One_Package (P : Entity_Id; N : Node_Id);
480 -- Make visible entities declared in package P potentially use-visible
481 -- in the current context. Also used in the analysis of subunits, when
482 -- re-installing use clauses of parent units. N is the use_clause that
483 -- names P (and possibly other packages).
485 procedure Use_One_Type (Id : Node_Id);
486 -- Id is the subtype mark from a use type clause. This procedure makes
487 -- the primitive operators of the type potentially use-visible.
489 procedure Write_Info;
490 -- Write debugging information on entities declared in current scope
492 procedure Write_Scopes;
493 pragma Warnings (Off, Write_Scopes);
494 -- Debugging information: dump all entities on scope stack
496 --------------------------------
497 -- Analyze_Exception_Renaming --
498 --------------------------------
500 -- The language only allows a single identifier, but the tree holds
501 -- an identifier list. The parser has already issued an error message
502 -- if there is more than one element in the list.
504 procedure Analyze_Exception_Renaming (N : Node_Id) is
505 Id : constant Node_Id := Defining_Identifier (N);
506 Nam : constant Node_Id := Name (N);
512 Set_Ekind (Id, E_Exception);
513 Set_Exception_Code (Id, Uint_0);
514 Set_Etype (Id, Standard_Exception_Type);
515 Set_Is_Pure (Id, Is_Pure (Current_Scope));
517 if not Is_Entity_Name (Nam) or else
518 Ekind (Entity (Nam)) /= E_Exception
520 Error_Msg_N ("invalid exception name in renaming", Nam);
522 if Present (Renamed_Object (Entity (Nam))) then
523 Set_Renamed_Object (Id, Renamed_Object (Entity (Nam)));
525 Set_Renamed_Object (Id, Entity (Nam));
528 end Analyze_Exception_Renaming;
530 ---------------------------
531 -- Analyze_Expanded_Name --
532 ---------------------------
534 procedure Analyze_Expanded_Name (N : Node_Id) is
536 -- If the entity pointer is already set, this is an internal node, or
537 -- a node that is analyzed more than once, after a tree modification.
538 -- In such a case there is no resolution to perform, just set the type.
539 -- For completeness, analyze prefix as well.
541 if Present (Entity (N)) then
542 if Is_Type (Entity (N)) then
543 Set_Etype (N, Entity (N));
545 Set_Etype (N, Etype (Entity (N)));
548 Analyze (Prefix (N));
551 Find_Expanded_Name (N);
553 end Analyze_Expanded_Name;
555 ---------------------------------------
556 -- Analyze_Generic_Function_Renaming --
557 ---------------------------------------
559 procedure Analyze_Generic_Function_Renaming (N : Node_Id) is
561 Analyze_Generic_Renaming (N, E_Generic_Function);
562 end Analyze_Generic_Function_Renaming;
564 --------------------------------------
565 -- Analyze_Generic_Package_Renaming --
566 --------------------------------------
568 procedure Analyze_Generic_Package_Renaming (N : Node_Id) is
570 -- Apply the Text_IO Kludge here, since we may be renaming
571 -- one of the subpackages of Text_IO, then join common routine.
573 Text_IO_Kludge (Name (N));
575 Analyze_Generic_Renaming (N, E_Generic_Package);
576 end Analyze_Generic_Package_Renaming;
578 ----------------------------------------
579 -- Analyze_Generic_Procedure_Renaming --
580 ----------------------------------------
582 procedure Analyze_Generic_Procedure_Renaming (N : Node_Id) is
584 Analyze_Generic_Renaming (N, E_Generic_Procedure);
585 end Analyze_Generic_Procedure_Renaming;
587 ------------------------------
588 -- Analyze_Generic_Renaming --
589 ------------------------------
591 procedure Analyze_Generic_Renaming
595 New_P : constant Entity_Id := Defining_Entity (N);
597 Inst : Boolean := False; -- prevent junk warning
600 if Name (N) = Error then
604 Generate_Definition (New_P);
606 if Current_Scope /= Standard_Standard then
607 Set_Is_Pure (New_P, Is_Pure (Current_Scope));
610 if Nkind (Name (N)) = N_Selected_Component then
611 Check_Generic_Child_Unit (Name (N), Inst);
616 if not Is_Entity_Name (Name (N)) then
617 Error_Msg_N ("expect entity name in renaming declaration", Name (N));
620 Old_P := Entity (Name (N));
624 Set_Ekind (New_P, K);
626 if Etype (Old_P) = Any_Type then
629 elsif Ekind (Old_P) /= K then
630 Error_Msg_N ("invalid generic unit name", Name (N));
633 if Present (Renamed_Object (Old_P)) then
634 Set_Renamed_Object (New_P, Renamed_Object (Old_P));
636 Set_Renamed_Object (New_P, Old_P);
639 Set_Etype (New_P, Etype (Old_P));
640 Set_Has_Completion (New_P);
642 if In_Open_Scopes (Old_P) then
643 Error_Msg_N ("within its scope, generic denotes its instance", N);
646 Check_Library_Unit_Renaming (N, Old_P);
649 end Analyze_Generic_Renaming;
651 -----------------------------
652 -- Analyze_Object_Renaming --
653 -----------------------------
655 procedure Analyze_Object_Renaming (N : Node_Id) is
656 Id : constant Entity_Id := Defining_Identifier (N);
658 Nam : constant Node_Id := Name (N);
667 Set_Is_Pure (Id, Is_Pure (Current_Scope));
670 -- The renaming of a component that depends on a discriminant
671 -- requires an actual subtype, because in subsequent use of the object
672 -- Gigi will be unable to locate the actual bounds. This explicit step
673 -- is required when the renaming is generated in removing side effects
674 -- of an already-analyzed expression.
676 if Nkind (Nam) = N_Selected_Component
677 and then Analyzed (Nam)
680 Dec := Build_Actual_Subtype_Of_Component (Etype (Nam), Nam);
682 if Present (Dec) then
683 Insert_Action (N, Dec);
684 T := Defining_Identifier (Dec);
688 elsif Present (Subtype_Mark (N)) then
689 Find_Type (Subtype_Mark (N));
690 T := Entity (Subtype_Mark (N));
691 Analyze_And_Resolve (Nam, T);
693 -- Ada 2005 (AI-230/AI-254): Access renaming
695 else pragma Assert (Present (Access_Definition (N)));
696 T := Access_Definition
698 N => Access_Definition (N));
700 Analyze_And_Resolve (Nam, T);
702 -- Ada 2005 (AI-231): "In the case where the type is defined by an
703 -- access_definition, the renamed entity shall be of an access-to-
704 -- constant type if and only if the access_definition defines an
705 -- access-to-constant type" ARM 8.5.1(4)
707 if Constant_Present (Access_Definition (N))
708 and then not Is_Access_Constant (Etype (Nam))
710 Error_Msg_N ("(Ada 2005): the renamed object is not "
711 & "access-to-constant ('R'M 8.5.1(6))", N);
713 elsif Null_Exclusion_Present (Access_Definition (N)) then
714 Error_Msg_N ("(Ada 2005): null-excluding attribute ignored "
715 & "('R'M 8.5.1(6))?", N);
719 -- An object renaming requires an exact match of the type;
720 -- class-wide matching is not allowed.
722 if Is_Class_Wide_Type (T)
723 and then Base_Type (Etype (Nam)) /= Base_Type (T)
729 Set_Ekind (Id, E_Variable);
730 Init_Size_Align (Id);
732 if T = Any_Type or else Etype (Nam) = Any_Type then
735 -- Verify that the renamed entity is an object or a function call.
736 -- It may have been rewritten in several ways.
738 elsif Is_Object_Reference (Nam) then
739 if Comes_From_Source (N)
740 and then Is_Dependent_Component_Of_Mutable_Object (Nam)
743 ("illegal renaming of discriminant-dependent component", Nam);
748 -- A static function call may have been folded into a literal
750 elsif Nkind (Original_Node (Nam)) = N_Function_Call
752 -- When expansion is disabled, attribute reference is not
753 -- rewritten as function call. Otherwise it may be rewritten
754 -- as a conversion, so check original node.
756 or else (Nkind (Original_Node (Nam)) = N_Attribute_Reference
757 and then Is_Function_Attribute_Name
758 (Attribute_Name (Original_Node (Nam))))
760 -- Weird but legal, equivalent to renaming a function call
762 or else (Is_Entity_Name (Nam)
763 and then Ekind (Entity (Nam)) = E_Enumeration_Literal)
765 or else (Nkind (Nam) = N_Type_Conversion
766 and then Is_Tagged_Type (Entity (Subtype_Mark (Nam))))
771 if Nkind (Nam) = N_Type_Conversion then
773 ("renaming of conversion only allowed for tagged types", Nam);
776 Error_Msg_N ("expect object name in renaming", Nam);
782 if not Is_Variable (Nam) then
783 Set_Ekind (Id, E_Constant);
784 Set_Never_Set_In_Source (Id, True);
785 Set_Is_True_Constant (Id, True);
788 Set_Renamed_Object (Id, Nam);
789 end Analyze_Object_Renaming;
791 ------------------------------
792 -- Analyze_Package_Renaming --
793 ------------------------------
795 procedure Analyze_Package_Renaming (N : Node_Id) is
796 New_P : constant Entity_Id := Defining_Entity (N);
801 if Name (N) = Error then
805 -- Apply Text_IO kludge here, since we may be renaming one of
806 -- the children of Text_IO
808 Text_IO_Kludge (Name (N));
810 if Current_Scope /= Standard_Standard then
811 Set_Is_Pure (New_P, Is_Pure (Current_Scope));
816 if Is_Entity_Name (Name (N)) then
817 Old_P := Entity (Name (N));
822 if Etype (Old_P) = Any_Type then
824 ("expect package name in renaming", Name (N));
826 -- Ada 2005 (AI-50217): Limited withed packages can not be renamed
828 elsif Ekind (Old_P) = E_Package
829 and then From_With_Type (Old_P)
832 ("limited withed package cannot be renamed", Name (N));
834 elsif Ekind (Old_P) /= E_Package
835 and then not (Ekind (Old_P) = E_Generic_Package
836 and then In_Open_Scopes (Old_P))
838 if Ekind (Old_P) = E_Generic_Package then
840 ("generic package cannot be renamed as a package", Name (N));
842 Error_Msg_Sloc := Sloc (Old_P);
844 ("expect package name in renaming, found& declared#",
848 -- Set basic attributes to minimize cascaded errors
850 Set_Ekind (New_P, E_Package);
851 Set_Etype (New_P, Standard_Void_Type);
854 -- Entities in the old package are accessible through the
855 -- renaming entity. The simplest implementation is to have
856 -- both packages share the entity list.
858 Set_Ekind (New_P, E_Package);
859 Set_Etype (New_P, Standard_Void_Type);
861 if Present (Renamed_Object (Old_P)) then
862 Set_Renamed_Object (New_P, Renamed_Object (Old_P));
864 Set_Renamed_Object (New_P, Old_P);
867 Set_Has_Completion (New_P);
869 Set_First_Entity (New_P, First_Entity (Old_P));
870 Set_Last_Entity (New_P, Last_Entity (Old_P));
871 Set_First_Private_Entity (New_P, First_Private_Entity (Old_P));
872 Check_Library_Unit_Renaming (N, Old_P);
873 Generate_Reference (Old_P, Name (N));
875 -- If this is the renaming declaration of a package instantiation
876 -- within itself, it is the declaration that ends the list of actuals
877 -- for the instantiation. At this point, the subtypes that rename
878 -- the actuals are flagged as generic, to avoid spurious ambiguities
879 -- if the actuals for two distinct formals happen to coincide. If
880 -- the actual is a private type, the subtype has a private completion
881 -- that is flagged in the same fashion.
883 -- Resolution is identical to what is was in the original generic.
884 -- On exit from the generic instance, these are turned into regular
885 -- subtypes again, so they are compatible with types in their class.
887 if not Is_Generic_Instance (Old_P) then
890 Spec := Specification (Unit_Declaration_Node (Old_P));
893 if Nkind (Spec) = N_Package_Specification
894 and then Present (Generic_Parent (Spec))
895 and then Old_P = Current_Scope
896 and then Chars (New_P) = Chars (Generic_Parent (Spec))
899 E : Entity_Id := First_Entity (Old_P);
905 and then Nkind (Parent (E)) = N_Subtype_Declaration
907 Set_Is_Generic_Actual_Type (E);
909 if Is_Private_Type (E)
910 and then Present (Full_View (E))
912 Set_Is_Generic_Actual_Type (Full_View (E));
922 end Analyze_Package_Renaming;
924 -------------------------------
925 -- Analyze_Renamed_Character --
926 -------------------------------
928 procedure Analyze_Renamed_Character
933 C : constant Node_Id := Name (N);
936 if Ekind (New_S) = E_Function then
937 Resolve (C, Etype (New_S));
940 Check_Frozen_Renaming (N, New_S);
944 Error_Msg_N ("character literal can only be renamed as function", N);
946 end Analyze_Renamed_Character;
948 ---------------------------------
949 -- Analyze_Renamed_Dereference --
950 ---------------------------------
952 procedure Analyze_Renamed_Dereference
957 Nam : constant Node_Id := Name (N);
958 P : constant Node_Id := Prefix (Nam);
964 if not Is_Overloaded (P) then
965 if Ekind (Etype (Nam)) /= E_Subprogram_Type
966 or else not Type_Conformant (Etype (Nam), New_S) then
967 Error_Msg_N ("designated type does not match specification", P);
976 Get_First_Interp (Nam, Ind, It);
978 while Present (It.Nam) loop
980 if Ekind (It.Nam) = E_Subprogram_Type
981 and then Type_Conformant (It.Nam, New_S) then
983 if Typ /= Any_Id then
984 Error_Msg_N ("ambiguous renaming", P);
991 Get_Next_Interp (Ind, It);
994 if Typ = Any_Type then
995 Error_Msg_N ("designated type does not match specification", P);
1000 Check_Frozen_Renaming (N, New_S);
1004 end Analyze_Renamed_Dereference;
1006 ---------------------------
1007 -- Analyze_Renamed_Entry --
1008 ---------------------------
1010 procedure Analyze_Renamed_Entry
1015 Nam : constant Node_Id := Name (N);
1016 Sel : constant Node_Id := Selector_Name (Nam);
1020 if Entity (Sel) = Any_Id then
1022 -- Selector is undefined on prefix. Error emitted already
1024 Set_Has_Completion (New_S);
1028 -- Otherwise, find renamed entity, and build body of New_S as a call
1031 Old_S := Find_Renamed_Entity (N, Selector_Name (Nam), New_S);
1033 if Old_S = Any_Id then
1034 Error_Msg_N (" no subprogram or entry matches specification", N);
1037 Check_Subtype_Conformant (New_S, Old_S, N);
1038 Generate_Reference (New_S, Defining_Entity (N), 'b');
1039 Style.Check_Identifier (Defining_Entity (N), New_S);
1042 Inherit_Renamed_Profile (New_S, Old_S);
1045 Set_Convention (New_S, Convention (Old_S));
1046 Set_Has_Completion (New_S, Inside_A_Generic);
1049 Check_Frozen_Renaming (N, New_S);
1051 end Analyze_Renamed_Entry;
1053 -----------------------------------
1054 -- Analyze_Renamed_Family_Member --
1055 -----------------------------------
1057 procedure Analyze_Renamed_Family_Member
1062 Nam : constant Node_Id := Name (N);
1063 P : constant Node_Id := Prefix (Nam);
1067 if (Is_Entity_Name (P) and then Ekind (Entity (P)) = E_Entry_Family)
1068 or else (Nkind (P) = N_Selected_Component
1070 Ekind (Entity (Selector_Name (P))) = E_Entry_Family)
1072 if Is_Entity_Name (P) then
1073 Old_S := Entity (P);
1075 Old_S := Entity (Selector_Name (P));
1078 if not Entity_Matches_Spec (Old_S, New_S) then
1079 Error_Msg_N ("entry family does not match specification", N);
1082 Check_Subtype_Conformant (New_S, Old_S, N);
1083 Generate_Reference (New_S, Defining_Entity (N), 'b');
1084 Style.Check_Identifier (Defining_Entity (N), New_S);
1087 Error_Msg_N ("no entry family matches specification", N);
1090 Set_Has_Completion (New_S, Inside_A_Generic);
1093 Check_Frozen_Renaming (N, New_S);
1095 end Analyze_Renamed_Family_Member;
1097 ---------------------------------
1098 -- Analyze_Subprogram_Renaming --
1099 ---------------------------------
1101 procedure Analyze_Subprogram_Renaming (N : Node_Id) is
1102 Spec : constant Node_Id := Specification (N);
1103 Save_AV : constant Ada_Version_Type := Ada_Version;
1104 Nam : constant Node_Id := Name (N);
1106 Old_S : Entity_Id := Empty;
1107 Rename_Spec : Entity_Id;
1108 Formal_Spec : constant Node_Id := Corresponding_Formal_Spec (N);
1109 Is_Actual : constant Boolean := Present (Formal_Spec);
1110 Inst_Node : Node_Id := Empty;
1112 function Original_Subprogram (Subp : Entity_Id) return Entity_Id;
1113 -- Find renamed entity when the declaration is a renaming_as_body
1114 -- and the renamed entity may itself be a renaming_as_body. Used to
1115 -- enforce rule that a renaming_as_body is illegal if the declaration
1116 -- occurs before the subprogram it completes is frozen, and renaming
1117 -- indirectly renames the subprogram itself.(Defect Report 8652/0027).
1119 -------------------------
1120 -- Original_Subprogram --
1121 -------------------------
1123 function Original_Subprogram (Subp : Entity_Id) return Entity_Id is
1124 Orig_Decl : Node_Id;
1125 Orig_Subp : Entity_Id;
1128 -- First case: renamed entity is itself a renaming
1130 if Present (Alias (Subp)) then
1131 return Alias (Subp);
1134 Nkind (Unit_Declaration_Node (Subp)) = N_Subprogram_Declaration
1136 (Corresponding_Body (Unit_Declaration_Node (Subp)))
1138 -- Check if renamed entity is a renaming_as_body
1141 Unit_Declaration_Node
1142 (Corresponding_Body (Unit_Declaration_Node (Subp)));
1144 if Nkind (Orig_Decl) = N_Subprogram_Renaming_Declaration then
1145 Orig_Subp := Entity (Name (Orig_Decl));
1147 if Orig_Subp = Rename_Spec then
1149 -- Circularity detected
1154 return (Original_Subprogram (Orig_Subp));
1162 end Original_Subprogram;
1164 -- Start of processing for Analyze_Subprogram_Renaming
1167 -- We must test for the attribute renaming case before the Analyze
1168 -- call because otherwise Sem_Attr will complain that the attribute
1169 -- is missing an argument when it is analyzed.
1171 if Nkind (Nam) = N_Attribute_Reference then
1173 -- In the case of an abstract formal subprogram association,
1174 -- rewrite an actual given by a stream attribute as the name
1175 -- of the corresponding stream primitive of the type.
1177 if Is_Actual and then Is_Abstract (Formal_Spec) then
1179 Stream_Prim : Entity_Id;
1180 Prefix_Type : constant Entity_Id := Entity (Prefix (Nam));
1183 -- The class-wide forms of the stream attributes are not
1184 -- primitive dispatching operations (even though they
1185 -- internally dispatch to a stream attribute).
1187 if Is_Class_Wide_Type (Prefix_Type) then
1189 ("attribute must be a primitive dispatching operation",
1194 -- Retrieve the primitive subprogram associated with the
1195 -- attribute. This can only be a stream attribute, since
1196 -- those are the only ones that are dispatching (and the
1197 -- actual for an abstract formal subprogram must be a
1198 -- dispatching operation).
1200 case Attribute_Name (Nam) is
1203 Find_Prim_Op (Prefix_Type, TSS_Stream_Input);
1206 Find_Prim_Op (Prefix_Type, TSS_Stream_Output);
1209 Find_Prim_Op (Prefix_Type, TSS_Stream_Read);
1212 Find_Prim_Op (Prefix_Type, TSS_Stream_Write);
1215 ("attribute must be a primitive dispatching operation",
1220 -- Rewrite the attribute into the name of its corresponding
1221 -- primitive dispatching subprogram. We can then proceed with
1222 -- the usual processing for subprogram renamings.
1225 Prim_Name : constant Node_Id :=
1226 Make_Identifier (Sloc (Nam),
1227 Chars => Chars (Stream_Prim));
1229 Set_Entity (Prim_Name, Stream_Prim);
1230 Rewrite (Nam, Prim_Name);
1235 -- Normal processing for a renaming of an attribute
1238 Attribute_Renaming (N);
1243 -- Check whether this declaration corresponds to the instantiation
1244 -- of a formal subprogram.
1246 -- If this is an instantiation, the corresponding actual is frozen
1247 -- and error messages can be made more precise. If this is a default
1248 -- subprogram, the entity is already established in the generic, and
1249 -- is not retrieved by visibility. If it is a default with a box, the
1250 -- candidate interpretations, if any, have been collected when building
1251 -- the renaming declaration. If overloaded, the proper interpretation
1252 -- is determined in Find_Renamed_Entity. If the entity is an operator,
1253 -- Find_Renamed_Entity applies additional visibility checks.
1256 Inst_Node := Unit_Declaration_Node (Formal_Spec);
1258 if Is_Entity_Name (Nam)
1259 and then Present (Entity (Nam))
1260 and then not Comes_From_Source (Nam)
1261 and then not Is_Overloaded (Nam)
1263 Old_S := Entity (Nam);
1264 New_S := Analyze_Subprogram_Specification (Spec);
1268 if Ekind (Entity (Nam)) = E_Operator then
1272 if Box_Present (Inst_Node) then
1273 Old_S := Find_Renamed_Entity (N, Name (N), New_S, Is_Actual);
1275 -- If there is an immediately visible homonym of the operator
1276 -- and the declaration has a default, this is worth a warning
1277 -- because the user probably did not intend to get the pre-
1278 -- defined operator, visible in the generic declaration.
1279 -- To find if there is an intended candidate, analyze the
1280 -- renaming again in the current context.
1282 elsif Scope (Old_S) = Standard_Standard
1283 and then Present (Default_Name (Inst_Node))
1286 Decl : constant Node_Id := New_Copy_Tree (N);
1290 Set_Entity (Name (Decl), Empty);
1291 Analyze (Name (Decl));
1293 Find_Renamed_Entity (Decl, Name (Decl), New_S, True);
1296 and then In_Open_Scopes (Scope (Hidden))
1297 and then Is_Immediately_Visible (Hidden)
1298 and then Comes_From_Source (Hidden)
1299 and then Hidden /= Old_S
1301 Error_Msg_Sloc := Sloc (Hidden);
1302 Error_Msg_N ("?default subprogram is resolved " &
1303 "in the generic declaration " &
1304 "('R'M 12.6(17))", N);
1305 Error_Msg_NE ("\?and will not use & #", N, Hidden);
1313 New_S := Analyze_Subprogram_Specification (Spec);
1317 -- Renamed entity must be analyzed first, to avoid being hidden by
1318 -- new name (which might be the same in a generic instance).
1322 -- The renaming defines a new overloaded entity, which is analyzed
1323 -- like a subprogram declaration.
1325 New_S := Analyze_Subprogram_Specification (Spec);
1328 if Current_Scope /= Standard_Standard then
1329 Set_Is_Pure (New_S, Is_Pure (Current_Scope));
1332 Rename_Spec := Find_Corresponding_Spec (N);
1334 if Present (Rename_Spec) then
1336 -- Renaming_As_Body. Renaming declaration is the completion of
1337 -- the declaration of Rename_Spec. We will build an actual body
1338 -- for it at the freezing point.
1340 Set_Corresponding_Spec (N, Rename_Spec);
1341 Set_Corresponding_Body (Unit_Declaration_Node (Rename_Spec), New_S);
1343 if Ada_Version = Ada_83 and then Comes_From_Source (N) then
1344 Error_Msg_N ("(Ada 83) renaming cannot serve as a body", N);
1347 Set_Convention (New_S, Convention (Rename_Spec));
1348 Check_Fully_Conformant (New_S, Rename_Spec);
1349 Set_Public_Status (New_S);
1351 -- Indicate that the entity in the declaration functions like
1352 -- the corresponding body, and is not a new entity. The body will
1353 -- be constructed later at the freeze point, so indicate that
1354 -- the completion has not been seen yet.
1356 Set_Ekind (New_S, E_Subprogram_Body);
1357 New_S := Rename_Spec;
1358 Set_Has_Completion (Rename_Spec, False);
1361 Generate_Definition (New_S);
1362 New_Overloaded_Entity (New_S);
1363 if Is_Entity_Name (Nam)
1364 and then Is_Intrinsic_Subprogram (Entity (Nam))
1368 Check_Delayed_Subprogram (New_S);
1372 -- There is no need for elaboration checks on the new entity, which
1373 -- may be called before the next freezing point where the body will
1374 -- appear. Elaboration checks refer to the real entity, not the one
1375 -- created by the renaming declaration.
1377 Set_Kill_Elaboration_Checks (New_S, True);
1379 if Etype (Nam) = Any_Type then
1380 Set_Has_Completion (New_S);
1383 elsif Nkind (Nam) = N_Selected_Component then
1385 -- Renamed entity is an entry or protected subprogram. For those
1386 -- cases an explicit body is built (at the point of freezing of
1387 -- this entity) that contains a call to the renamed entity.
1389 Analyze_Renamed_Entry (N, New_S, Present (Rename_Spec));
1392 elsif Nkind (Nam) = N_Explicit_Dereference then
1394 -- Renamed entity is designated by access_to_subprogram expression.
1395 -- Must build body to encapsulate call, as in the entry case.
1397 Analyze_Renamed_Dereference (N, New_S, Present (Rename_Spec));
1400 elsif Nkind (Nam) = N_Indexed_Component then
1401 Analyze_Renamed_Family_Member (N, New_S, Present (Rename_Spec));
1404 elsif Nkind (Nam) = N_Character_Literal then
1405 Analyze_Renamed_Character (N, New_S, Present (Rename_Spec));
1408 elsif (not Is_Entity_Name (Nam)
1409 and then Nkind (Nam) /= N_Operator_Symbol)
1410 or else not Is_Overloadable (Entity (Nam))
1412 Error_Msg_N ("expect valid subprogram name in renaming", N);
1417 -- Most common case: subprogram renames subprogram. No body is
1418 -- generated in this case, so we must indicate that the declaration
1419 -- is complete as is.
1421 if No (Rename_Spec) then
1422 Set_Has_Completion (New_S);
1425 -- Find the renamed entity that matches the given specification.
1426 -- Disable Ada_83 because there is no requirement of full conformance
1427 -- between renamed entity and new entity, even though the same circuit
1430 Ada_Version := Ada_Version_Type'Max (Ada_Version, Ada_95);
1433 Old_S := Find_Renamed_Entity (N, Name (N), New_S, Is_Actual);
1436 if Old_S /= Any_Id then
1438 and then From_Default (N)
1440 -- This is an implicit reference to the default actual
1442 Generate_Reference (Old_S, Nam, Typ => 'i', Force => True);
1444 Generate_Reference (Old_S, Nam);
1447 -- For a renaming-as-body, require subtype conformance,
1448 -- but if the declaration being completed has not been
1449 -- frozen, then inherit the convention of the renamed
1450 -- subprogram prior to checking conformance (unless the
1451 -- renaming has an explicit convention established; the
1452 -- rule stated in the RM doesn't seem to address this ???).
1454 if Present (Rename_Spec) then
1455 Generate_Reference (Rename_Spec, Defining_Entity (Spec), 'b');
1456 Style.Check_Identifier (Defining_Entity (Spec), Rename_Spec);
1458 if not Is_Frozen (Rename_Spec) then
1459 if not Has_Convention_Pragma (Rename_Spec) then
1460 Set_Convention (New_S, Convention (Old_S));
1463 if Ekind (Old_S) /= E_Operator then
1464 Check_Mode_Conformant (New_S, Old_S, Spec);
1467 if Original_Subprogram (Old_S) = Rename_Spec then
1468 Error_Msg_N ("unfrozen subprogram cannot rename itself ", N);
1471 Check_Subtype_Conformant (New_S, Old_S, Spec);
1474 Check_Frozen_Renaming (N, Rename_Spec);
1476 -- Check explicitly that renamed entity is not intrinsic, because
1477 -- in in a generic the renamed body is not built. In this case,
1478 -- the renaming_as_body is a completion.
1480 if Inside_A_Generic then
1481 if Is_Frozen (Rename_Spec)
1482 and then Is_Intrinsic_Subprogram (Old_S)
1485 ("subprogram in renaming_as_body cannot be intrinsic",
1489 Set_Has_Completion (Rename_Spec);
1492 elsif Ekind (Old_S) /= E_Operator then
1493 Check_Mode_Conformant (New_S, Old_S);
1496 and then Error_Posted (New_S)
1498 Error_Msg_NE ("invalid actual subprogram: & #!", N, Old_S);
1502 if No (Rename_Spec) then
1504 -- The parameter profile of the new entity is that of the renamed
1505 -- entity: the subtypes given in the specification are irrelevant.
1507 Inherit_Renamed_Profile (New_S, Old_S);
1509 -- A call to the subprogram is transformed into a call to the
1510 -- renamed entity. This is transitive if the renamed entity is
1511 -- itself a renaming.
1513 if Present (Alias (Old_S)) then
1514 Set_Alias (New_S, Alias (Old_S));
1516 Set_Alias (New_S, Old_S);
1519 -- Note that we do not set Is_Intrinsic_Subprogram if we have
1520 -- a renaming as body, since the entity in this case is not an
1521 -- intrinsic (it calls an intrinsic, but we have a real body
1522 -- for this call, and it is in this body that the required
1523 -- intrinsic processing will take place).
1525 -- Also, if this is a renaming of inequality, the renamed
1526 -- operator is intrinsic, but what matters is the corresponding
1527 -- equality operator, which may be user-defined.
1529 Set_Is_Intrinsic_Subprogram
1531 Is_Intrinsic_Subprogram (Old_S)
1533 (Chars (Old_S) /= Name_Op_Ne
1534 or else Ekind (Old_S) = E_Operator
1536 Is_Intrinsic_Subprogram
1537 (Corresponding_Equality (Old_S))));
1539 if Ekind (Alias (New_S)) = E_Operator then
1540 Set_Has_Delayed_Freeze (New_S, False);
1543 -- If the renaming corresponds to an association for an abstract
1544 -- formal subprogram, then various attributes must be set to
1545 -- indicate that the renaming is an abstract dispatching operation
1546 -- with a controlling type.
1548 if Is_Actual and then Is_Abstract (Formal_Spec) then
1549 -- Mark the renaming as abstract here, so Find_Dispatching_Type
1550 -- see it as corresponding to a generic association for a
1551 -- formal abstract subprogram
1553 Set_Is_Abstract (New_S);
1556 New_S_Ctrl_Type : constant Entity_Id :=
1557 Find_Dispatching_Type (New_S);
1558 Old_S_Ctrl_Type : constant Entity_Id :=
1559 Find_Dispatching_Type (Old_S);
1562 if Old_S_Ctrl_Type /= New_S_Ctrl_Type then
1564 ("actual must be dispatching subprogram for type&",
1565 Nam, New_S_Ctrl_Type);
1568 Set_Is_Dispatching_Operation (New_S);
1569 Check_Controlling_Formals (New_S_Ctrl_Type, New_S);
1571 -- In the case where the actual in the formal subprogram
1572 -- is itself a formal abstract subprogram association,
1573 -- there's no dispatch table component or position to
1576 if Present (DTC_Entity (Old_S)) then
1577 Set_DTC_Entity (New_S, DTC_Entity (Old_S));
1578 Set_DT_Position (New_S, DT_Position (Old_S));
1586 and then (Old_S = New_S
1587 or else (Nkind (Nam) /= N_Expanded_Name
1588 and then Chars (Old_S) = Chars (New_S)))
1590 Error_Msg_N ("subprogram cannot rename itself", N);
1593 Set_Convention (New_S, Convention (Old_S));
1594 Set_Is_Abstract (New_S, Is_Abstract (Old_S));
1595 Check_Library_Unit_Renaming (N, Old_S);
1597 -- Pathological case: procedure renames entry in the scope of
1598 -- its task. Entry is given by simple name, but body must be built
1599 -- for procedure. Of course if called it will deadlock.
1601 if Ekind (Old_S) = E_Entry then
1602 Set_Has_Completion (New_S, False);
1603 Set_Alias (New_S, Empty);
1607 Freeze_Before (N, Old_S);
1608 Set_Has_Delayed_Freeze (New_S, False);
1609 Freeze_Before (N, New_S);
1611 -- An abstract subprogram is only allowed as an actual in the case
1612 -- where the formal subprogram is also abstract.
1614 if (Ekind (Old_S) = E_Procedure or else Ekind (Old_S) = E_Function)
1615 and then Is_Abstract (Old_S)
1616 and then not Is_Abstract (Formal_Spec)
1619 ("abstract subprogram not allowed as generic actual", Nam);
1624 -- A common error is to assume that implicit operators for types
1625 -- are defined in Standard, or in the scope of a subtype. In those
1626 -- cases where the renamed entity is given with an expanded name,
1627 -- it is worth mentioning that operators for the type are not
1628 -- declared in the scope given by the prefix.
1630 if Nkind (Nam) = N_Expanded_Name
1631 and then Nkind (Selector_Name (Nam)) = N_Operator_Symbol
1632 and then Scope (Entity (Nam)) = Standard_Standard
1635 T : constant Entity_Id :=
1636 Base_Type (Etype (First_Formal (New_S)));
1639 Error_Msg_Node_2 := Prefix (Nam);
1641 ("operator for type& is not declared in&", Prefix (Nam), T);
1646 ("no visible subprogram matches the specification for&",
1650 if Present (Candidate_Renaming) then
1656 F1 := First_Formal (Candidate_Renaming);
1657 F2 := First_Formal (New_S);
1659 while Present (F1) and then Present (F2) loop
1664 if Present (F1) and then Present (Default_Value (F1)) then
1665 if Present (Next_Formal (F1)) then
1667 ("\missing specification for &" &
1668 " and other formals with defaults", Spec, F1);
1671 ("\missing specification for &", Spec, F1);
1678 Ada_Version := Save_AV;
1679 end Analyze_Subprogram_Renaming;
1681 -------------------------
1682 -- Analyze_Use_Package --
1683 -------------------------
1685 -- Resolve the package names in the use clause, and make all the visible
1686 -- entities defined in the package potentially use-visible. If the package
1687 -- is already in use from a previous use clause, its visible entities are
1688 -- already use-visible. In that case, mark the occurrence as a redundant
1689 -- use. If the package is an open scope, i.e. if the use clause occurs
1690 -- within the package itself, ignore it.
1692 procedure Analyze_Use_Package (N : Node_Id) is
1693 Pack_Name : Node_Id;
1696 -- Start of processing for Analyze_Use_Package
1699 Set_Hidden_By_Use_Clause (N, No_Elist);
1701 -- Use clause is not allowed in a spec of a predefined package
1702 -- declaration except that packages whose file name starts a-n
1703 -- are OK (these are children of Ada.Numerics, and such packages
1704 -- are never loaded by Rtsfind).
1706 if Is_Predefined_File_Name (Unit_File_Name (Current_Sem_Unit))
1707 and then Name_Buffer (1 .. 3) /= "a-n"
1709 Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Declaration
1711 Error_Msg_N ("use clause not allowed in predefined spec", N);
1714 -- Chain clause to list of use clauses in current scope
1716 if Nkind (Parent (N)) /= N_Compilation_Unit then
1717 Chain_Use_Clause (N);
1720 -- Loop through package names to identify referenced packages
1722 Pack_Name := First (Names (N));
1724 while Present (Pack_Name) loop
1725 Analyze (Pack_Name);
1727 if Nkind (Parent (N)) = N_Compilation_Unit
1728 and then Nkind (Pack_Name) = N_Expanded_Name
1731 Pref : Node_Id := Prefix (Pack_Name);
1734 while Nkind (Pref) = N_Expanded_Name loop
1735 Pref := Prefix (Pref);
1738 if Entity (Pref) = Standard_Standard then
1740 ("predefined package Standard cannot appear"
1741 & " in a context clause", Pref);
1749 -- Loop through package names to mark all entities as potentially
1752 Pack_Name := First (Names (N));
1754 while Present (Pack_Name) loop
1756 if Is_Entity_Name (Pack_Name) then
1757 Pack := Entity (Pack_Name);
1759 if Ekind (Pack) /= E_Package
1760 and then Etype (Pack) /= Any_Type
1762 if Ekind (Pack) = E_Generic_Package then
1764 ("a generic package is not allowed in a use clause",
1767 Error_Msg_N ("& is not a usable package", Pack_Name);
1771 if Nkind (Parent (N)) = N_Compilation_Unit then
1772 Check_In_Previous_With_Clause (N, Pack_Name);
1775 if Applicable_Use (Pack_Name) then
1776 Use_One_Package (Pack, N);
1784 end Analyze_Use_Package;
1786 ----------------------
1787 -- Analyze_Use_Type --
1788 ----------------------
1790 procedure Analyze_Use_Type (N : Node_Id) is
1794 Set_Hidden_By_Use_Clause (N, No_Elist);
1796 -- Chain clause to list of use clauses in current scope
1798 if Nkind (Parent (N)) /= N_Compilation_Unit then
1799 Chain_Use_Clause (N);
1802 Id := First (Subtype_Marks (N));
1804 while Present (Id) loop
1807 if Entity (Id) /= Any_Type then
1810 if Nkind (Parent (N)) = N_Compilation_Unit then
1811 if Nkind (Id) = N_Identifier then
1812 Error_Msg_N ("Type is not directly visible", Id);
1814 elsif Is_Child_Unit (Scope (Entity (Id)))
1815 and then Scope (Entity (Id)) /= System_Aux_Id
1817 Check_In_Previous_With_Clause (N, Prefix (Id));
1824 end Analyze_Use_Type;
1826 --------------------
1827 -- Applicable_Use --
1828 --------------------
1830 function Applicable_Use (Pack_Name : Node_Id) return Boolean is
1831 Pack : constant Entity_Id := Entity (Pack_Name);
1834 if In_Open_Scopes (Pack) then
1837 elsif In_Use (Pack) then
1838 Set_Redundant_Use (Pack_Name, True);
1841 elsif Present (Renamed_Object (Pack))
1842 and then In_Use (Renamed_Object (Pack))
1844 Set_Redundant_Use (Pack_Name, True);
1852 ------------------------
1853 -- Attribute_Renaming --
1854 ------------------------
1856 procedure Attribute_Renaming (N : Node_Id) is
1857 Loc : constant Source_Ptr := Sloc (N);
1858 Nam : constant Node_Id := Name (N);
1859 Spec : constant Node_Id := Specification (N);
1860 New_S : constant Entity_Id := Defining_Unit_Name (Spec);
1861 Aname : constant Name_Id := Attribute_Name (Nam);
1863 Form_Num : Nat := 0;
1864 Expr_List : List_Id := No_List;
1866 Attr_Node : Node_Id;
1867 Body_Node : Node_Id;
1868 Param_Spec : Node_Id;
1871 Generate_Definition (New_S);
1873 -- This procedure is called in the context of subprogram renaming,
1874 -- and thus the attribute must be one that is a subprogram. All of
1875 -- those have at least one formal parameter, with the singular
1876 -- exception of AST_Entry (which is a real oddity, it is odd that
1877 -- this can be renamed at all!)
1879 if not Is_Non_Empty_List (Parameter_Specifications (Spec)) then
1880 if Aname /= Name_AST_Entry then
1882 ("subprogram renaming an attribute must have formals", N);
1887 Param_Spec := First (Parameter_Specifications (Spec));
1889 while Present (Param_Spec) loop
1890 Form_Num := Form_Num + 1;
1892 if Nkind (Parameter_Type (Param_Spec)) /= N_Access_Definition then
1893 Find_Type (Parameter_Type (Param_Spec));
1895 -- The profile of the new entity denotes the base type (s) of
1896 -- the types given in the specification. For access parameters
1897 -- there are no subtypes involved.
1899 Rewrite (Parameter_Type (Param_Spec),
1901 (Base_Type (Entity (Parameter_Type (Param_Spec))), Loc));
1904 if No (Expr_List) then
1905 Expr_List := New_List;
1908 Append_To (Expr_List,
1909 Make_Identifier (Loc,
1910 Chars => Chars (Defining_Identifier (Param_Spec))));
1912 -- The expressions in the attribute reference are not freeze
1913 -- points. Neither is the attribute as a whole, see below.
1915 Set_Must_Not_Freeze (Last (Expr_List));
1920 -- Immediate error if too many formals. Other mismatches in numbers
1921 -- of number of types of parameters are detected when we analyze the
1922 -- body of the subprogram that we construct.
1924 if Form_Num > 2 then
1925 Error_Msg_N ("too many formals for attribute", N);
1927 -- Error if the attribute reference has expressions that look
1928 -- like formal parameters.
1930 elsif Present (Expressions (Nam)) then
1931 Error_Msg_N ("illegal expressions in attribute reference", Nam);
1934 Aname = Name_Compose or else
1935 Aname = Name_Exponent or else
1936 Aname = Name_Leading_Part or else
1937 Aname = Name_Pos or else
1938 Aname = Name_Round or else
1939 Aname = Name_Scaling or else
1942 if Nkind (N) = N_Subprogram_Renaming_Declaration
1943 and then Present (Corresponding_Formal_Spec (N))
1946 ("generic actual cannot be attribute involving universal type",
1950 ("attribute involving a universal type cannot be renamed",
1955 -- AST_Entry is an odd case. It doesn't really make much sense to
1956 -- allow it to be renamed, but that's the DEC rule, so we have to
1957 -- do it right. The point is that the AST_Entry call should be made
1958 -- now, and what the function will return is the returned value.
1960 -- Note that there is no Expr_List in this case anyway
1962 if Aname = Name_AST_Entry then
1969 Ent := Make_Defining_Identifier (Loc, New_Internal_Name ('R'));
1972 Make_Object_Declaration (Loc,
1973 Defining_Identifier => Ent,
1974 Object_Definition =>
1975 New_Occurrence_Of (RTE (RE_AST_Handler), Loc),
1977 Constant_Present => True);
1979 Set_Assignment_OK (Decl, True);
1980 Insert_Action (N, Decl);
1981 Attr_Node := Make_Identifier (Loc, Chars (Ent));
1984 -- For all other attributes, we rewrite the attribute node to have
1985 -- a list of expressions corresponding to the subprogram formals.
1986 -- A renaming declaration is not a freeze point, and the analysis of
1987 -- the attribute reference should not freeze the type of the prefix.
1991 Make_Attribute_Reference (Loc,
1992 Prefix => Prefix (Nam),
1993 Attribute_Name => Aname,
1994 Expressions => Expr_List);
1996 Set_Must_Not_Freeze (Attr_Node);
1997 Set_Must_Not_Freeze (Prefix (Nam));
2000 -- Case of renaming a function
2002 if Nkind (Spec) = N_Function_Specification then
2004 if Is_Procedure_Attribute_Name (Aname) then
2005 Error_Msg_N ("attribute can only be renamed as procedure", Nam);
2009 Find_Type (Subtype_Mark (Spec));
2010 Rewrite (Subtype_Mark (Spec),
2011 New_Reference_To (Base_Type (Entity (Subtype_Mark (Spec))), Loc));
2014 Make_Subprogram_Body (Loc,
2015 Specification => Spec,
2016 Declarations => New_List,
2017 Handled_Statement_Sequence =>
2018 Make_Handled_Sequence_Of_Statements (Loc,
2019 Statements => New_List (
2020 Make_Return_Statement (Loc,
2021 Expression => Attr_Node))));
2023 -- Case of renaming a procedure
2026 if not Is_Procedure_Attribute_Name (Aname) then
2027 Error_Msg_N ("attribute can only be renamed as function", Nam);
2032 Make_Subprogram_Body (Loc,
2033 Specification => Spec,
2034 Declarations => New_List,
2035 Handled_Statement_Sequence =>
2036 Make_Handled_Sequence_Of_Statements (Loc,
2037 Statements => New_List (Attr_Node)));
2040 Rewrite (N, Body_Node);
2043 if Is_Compilation_Unit (New_S) then
2045 ("a library unit can only rename another library unit", N);
2048 Set_Etype (New_S, Base_Type (Etype (New_S)));
2050 -- We suppress elaboration warnings for the resulting entity, since
2051 -- clearly they are not needed, and more particularly, in the case
2052 -- of a generic formal subprogram, the resulting entity can appear
2053 -- after the instantiation itself, and thus look like a bogus case
2054 -- of access before elaboration.
2056 Set_Suppress_Elaboration_Warnings (New_S);
2058 end Attribute_Renaming;
2060 ----------------------
2061 -- Chain_Use_Clause --
2062 ----------------------
2064 procedure Chain_Use_Clause (N : Node_Id) is
2066 Set_Next_Use_Clause (N,
2067 Scope_Stack.Table (Scope_Stack.Last).First_Use_Clause);
2068 Scope_Stack.Table (Scope_Stack.Last).First_Use_Clause := N;
2069 end Chain_Use_Clause;
2071 ---------------------------
2072 -- Check_Frozen_Renaming --
2073 ---------------------------
2075 procedure Check_Frozen_Renaming (N : Node_Id; Subp : Entity_Id) is
2081 and then not Has_Completion (Subp)
2085 (Parent (Declaration_Node (Subp)), Defining_Entity (N));
2087 if Is_Entity_Name (Name (N)) then
2088 Old_S := Entity (Name (N));
2090 if not Is_Frozen (Old_S)
2091 and then Operating_Mode /= Check_Semantics
2093 Append_Freeze_Action (Old_S, B_Node);
2095 Insert_After (N, B_Node);
2099 if Is_Intrinsic_Subprogram (Old_S)
2100 and then not In_Instance
2103 ("subprogram used in renaming_as_body cannot be intrinsic",
2108 Insert_After (N, B_Node);
2112 end Check_Frozen_Renaming;
2114 -----------------------------------
2115 -- Check_In_Previous_With_Clause --
2116 -----------------------------------
2118 procedure Check_In_Previous_With_Clause
2122 Pack : constant Entity_Id := Entity (Original_Node (Nam));
2127 Item := First (Context_Items (Parent (N)));
2129 while Present (Item)
2132 if Nkind (Item) = N_With_Clause
2133 and then Entity (Name (Item)) = Pack
2137 -- Find root library unit in with_clause
2139 while Nkind (Par) = N_Expanded_Name loop
2140 Par := Prefix (Par);
2143 if Is_Child_Unit (Entity (Original_Node (Par))) then
2145 ("& is not directly visible", Par, Entity (Par));
2154 -- On exit, package is not mentioned in a previous with_clause.
2155 -- Check if its prefix is.
2157 if Nkind (Nam) = N_Expanded_Name then
2158 Check_In_Previous_With_Clause (N, Prefix (Nam));
2160 elsif Pack /= Any_Id then
2161 Error_Msg_NE ("& is not visible", Nam, Pack);
2163 end Check_In_Previous_With_Clause;
2165 ---------------------------------
2166 -- Check_Library_Unit_Renaming --
2167 ---------------------------------
2169 procedure Check_Library_Unit_Renaming (N : Node_Id; Old_E : Entity_Id) is
2173 if Nkind (Parent (N)) /= N_Compilation_Unit then
2176 elsif Scope (Old_E) /= Standard_Standard
2177 and then not Is_Child_Unit (Old_E)
2179 Error_Msg_N ("renamed unit must be a library unit", Name (N));
2181 -- Entities defined in Standard (operators and boolean literals) cannot
2182 -- be renamed as library units.
2184 elsif Scope (Old_E) = Standard_Standard
2185 and then Sloc (Old_E) = Standard_Location
2187 Error_Msg_N ("renamed unit must be a library unit", Name (N));
2189 elsif Present (Parent_Spec (N))
2190 and then Nkind (Unit (Parent_Spec (N))) = N_Generic_Package_Declaration
2191 and then not Is_Child_Unit (Old_E)
2194 ("renamed unit must be a child unit of generic parent", Name (N));
2196 elsif Nkind (N) in N_Generic_Renaming_Declaration
2197 and then Nkind (Name (N)) = N_Expanded_Name
2198 and then Is_Generic_Instance (Entity (Prefix (Name (N))))
2199 and then Is_Generic_Unit (Old_E)
2202 ("renamed generic unit must be a library unit", Name (N));
2204 elsif Ekind (Old_E) = E_Package
2205 or else Ekind (Old_E) = E_Generic_Package
2207 -- Inherit categorization flags
2209 New_E := Defining_Entity (N);
2210 Set_Is_Pure (New_E, Is_Pure (Old_E));
2211 Set_Is_Preelaborated (New_E, Is_Preelaborated (Old_E));
2212 Set_Is_Remote_Call_Interface (New_E,
2213 Is_Remote_Call_Interface (Old_E));
2214 Set_Is_Remote_Types (New_E, Is_Remote_Types (Old_E));
2215 Set_Is_Shared_Passive (New_E, Is_Shared_Passive (Old_E));
2217 end Check_Library_Unit_Renaming;
2223 procedure End_Scope is
2229 Id := First_Entity (Current_Scope);
2231 while Present (Id) loop
2232 -- An entity in the current scope is not necessarily the first one
2233 -- on its homonym chain. Find its predecessor if any,
2234 -- If it is an internal entity, it will not be in the visibility
2235 -- chain altogether, and there is nothing to unchain.
2237 if Id /= Current_Entity (Id) then
2238 Prev := Current_Entity (Id);
2239 while Present (Prev)
2240 and then Present (Homonym (Prev))
2241 and then Homonym (Prev) /= Id
2243 Prev := Homonym (Prev);
2246 -- Skip to end of loop if Id is not in the visibility chain
2248 if No (Prev) or else Homonym (Prev) /= Id then
2256 Outer := Homonym (Id);
2257 Set_Is_Immediately_Visible (Id, False);
2259 while Present (Outer) and then Scope (Outer) = Current_Scope loop
2260 Outer := Homonym (Outer);
2263 -- Reset homonym link of other entities, but do not modify link
2264 -- between entities in current scope, so that the back-end can have
2265 -- a proper count of local overloadings.
2268 Set_Name_Entity_Id (Chars (Id), Outer);
2270 elsif Scope (Prev) /= Scope (Id) then
2271 Set_Homonym (Prev, Outer);
2278 -- If the scope generated freeze actions, place them before the
2279 -- current declaration and analyze them. Type declarations and
2280 -- the bodies of initialization procedures can generate such nodes.
2281 -- We follow the parent chain until we reach a list node, which is
2282 -- the enclosing list of declarations. If the list appears within
2283 -- a protected definition, move freeze nodes outside the protected
2287 (Scope_Stack.Table (Scope_Stack.Last).Pending_Freeze_Actions)
2291 L : constant List_Id := Scope_Stack.Table
2292 (Scope_Stack.Last).Pending_Freeze_Actions;
2295 if Is_Itype (Current_Scope) then
2296 Decl := Associated_Node_For_Itype (Current_Scope);
2298 Decl := Parent (Current_Scope);
2303 while not (Is_List_Member (Decl))
2304 or else Nkind (Parent (Decl)) = N_Protected_Definition
2305 or else Nkind (Parent (Decl)) = N_Task_Definition
2307 Decl := Parent (Decl);
2310 Insert_List_Before_And_Analyze (Decl, L);
2319 ---------------------
2320 -- End_Use_Clauses --
2321 ---------------------
2323 procedure End_Use_Clauses (Clause : Node_Id) is
2327 -- Remove Use_Type clauses first, because they affect the
2328 -- visibility of operators in subsequent used packages.
2331 while Present (U) loop
2332 if Nkind (U) = N_Use_Type_Clause then
2336 Next_Use_Clause (U);
2340 while Present (U) loop
2341 if Nkind (U) = N_Use_Package_Clause then
2342 End_Use_Package (U);
2345 Next_Use_Clause (U);
2347 end End_Use_Clauses;
2349 ---------------------
2350 -- End_Use_Package --
2351 ---------------------
2353 procedure End_Use_Package (N : Node_Id) is
2354 Pack_Name : Node_Id;
2359 function Is_Primitive_Operator
2361 F : Entity_Id) return Boolean;
2362 -- Check whether Op is a primitive operator of a use-visible type
2364 ---------------------------
2365 -- Is_Primitive_Operator --
2366 ---------------------------
2368 function Is_Primitive_Operator
2370 F : Entity_Id) return Boolean
2372 T : constant Entity_Id := Etype (F);
2376 and then Scope (T) = Scope (Op);
2377 end Is_Primitive_Operator;
2379 -- Start of processing for End_Use_Package
2382 Pack_Name := First (Names (N));
2384 while Present (Pack_Name) loop
2385 Pack := Entity (Pack_Name);
2387 if Ekind (Pack) = E_Package then
2389 if In_Open_Scopes (Pack) then
2392 elsif not Redundant_Use (Pack_Name) then
2393 Set_In_Use (Pack, False);
2394 Id := First_Entity (Pack);
2396 while Present (Id) loop
2398 -- Preserve use-visibility of operators that are primitive
2399 -- operators of a type that is use_visible through an active
2402 if Nkind (Id) = N_Defining_Operator_Symbol
2404 (Is_Primitive_Operator (Id, First_Formal (Id))
2406 (Present (Next_Formal (First_Formal (Id)))
2408 Is_Primitive_Operator
2409 (Id, Next_Formal (First_Formal (Id)))))
2414 Set_Is_Potentially_Use_Visible (Id, False);
2417 if Is_Private_Type (Id)
2418 and then Present (Full_View (Id))
2420 Set_Is_Potentially_Use_Visible (Full_View (Id), False);
2426 if Present (Renamed_Object (Pack)) then
2427 Set_In_Use (Renamed_Object (Pack), False);
2430 if Chars (Pack) = Name_System
2431 and then Scope (Pack) = Standard_Standard
2432 and then Present_System_Aux
2434 Id := First_Entity (System_Aux_Id);
2436 while Present (Id) loop
2437 Set_Is_Potentially_Use_Visible (Id, False);
2439 if Is_Private_Type (Id)
2440 and then Present (Full_View (Id))
2442 Set_Is_Potentially_Use_Visible (Full_View (Id), False);
2448 Set_In_Use (System_Aux_Id, False);
2452 Set_Redundant_Use (Pack_Name, False);
2460 if Present (Hidden_By_Use_Clause (N)) then
2461 Elmt := First_Elmt (Hidden_By_Use_Clause (N));
2463 while Present (Elmt) loop
2464 Set_Is_Immediately_Visible (Node (Elmt));
2468 Set_Hidden_By_Use_Clause (N, No_Elist);
2470 end End_Use_Package;
2476 procedure End_Use_Type (N : Node_Id) is
2483 Id := First (Subtype_Marks (N));
2485 while Present (Id) loop
2487 -- A call to rtsfind may occur while analyzing a use_type clause,
2488 -- in which case the type marks are not resolved yet, and there is
2489 -- nothing to remove.
2491 if not Is_Entity_Name (Id)
2492 or else No (Entity (Id))
2499 if T = Any_Type then
2502 -- Note that the use_Type clause may mention a subtype of the
2503 -- type whose primitive operations have been made visible. Here
2504 -- as elsewhere, it is the base type that matters for visibility.
2506 elsif In_Open_Scopes (Scope (Base_Type (T))) then
2509 elsif not Redundant_Use (Id) then
2510 Set_In_Use (T, False);
2511 Set_In_Use (Base_Type (T), False);
2512 Op_List := Collect_Primitive_Operations (T);
2513 Elmt := First_Elmt (Op_List);
2515 while Present (Elmt) loop
2517 if Nkind (Node (Elmt)) = N_Defining_Operator_Symbol then
2518 Set_Is_Potentially_Use_Visible (Node (Elmt), False);
2530 ----------------------
2531 -- Find_Direct_Name --
2532 ----------------------
2534 procedure Find_Direct_Name (N : Node_Id) is
2539 Inst : Entity_Id := Empty;
2540 -- Enclosing instance, if any
2542 Homonyms : Entity_Id;
2543 -- Saves start of homonym chain
2545 Nvis_Entity : Boolean;
2546 -- Set True to indicate that at there is at least one entity on the
2547 -- homonym chain which, while not visible, is visible enough from the
2548 -- user point of view to warrant an error message of "not visible"
2549 -- rather than undefined.
2551 Nvis_Is_Private_Subprg : Boolean := False;
2552 -- Ada 2005 (AI-262): Set True to indicate that a form of Beaujolais
2553 -- effect concerning library subprograms has been detected. Used to
2554 -- generate the precise error message.
2556 function From_Actual_Package (E : Entity_Id) return Boolean;
2557 -- Returns true if the entity is declared in a package that is
2558 -- an actual for a formal package of the current instance. Such an
2559 -- entity requires special handling because it may be use-visible
2560 -- but hides directly visible entities defined outside the instance.
2562 function Known_But_Invisible (E : Entity_Id) return Boolean;
2563 -- This function determines whether the entity E (which is not
2564 -- visible) can reasonably be considered to be known to the writer
2565 -- of the reference. This is a heuristic test, used only for the
2566 -- purposes of figuring out whether we prefer to complain that an
2567 -- entity is undefined or invisible (and identify the declaration
2568 -- of the invisible entity in the latter case). The point here is
2569 -- that we don't want to complain that something is invisible and
2570 -- then point to something entirely mysterious to the writer.
2572 procedure Nvis_Messages;
2573 -- Called if there are no visible entries for N, but there is at least
2574 -- one non-directly visible, or hidden declaration. This procedure
2575 -- outputs an appropriate set of error messages.
2577 procedure Undefined (Nvis : Boolean);
2578 -- This function is called if the current node has no corresponding
2579 -- visible entity or entities. The value set in Msg indicates whether
2580 -- an error message was generated (multiple error messages for the
2581 -- same variable are generally suppressed, see body for details).
2582 -- Msg is True if an error message was generated, False if not. This
2583 -- value is used by the caller to determine whether or not to output
2584 -- additional messages where appropriate. The parameter is set False
2585 -- to get the message "X is undefined", and True to get the message
2586 -- "X is not visible".
2588 -------------------------
2589 -- From_Actual_Package --
2590 -------------------------
2592 function From_Actual_Package (E : Entity_Id) return Boolean is
2593 Scop : constant Entity_Id := Scope (E);
2597 if not In_Instance then
2600 Inst := Current_Scope;
2602 while Present (Inst)
2603 and then Ekind (Inst) /= E_Package
2604 and then not Is_Generic_Instance (Inst)
2606 Inst := Scope (Inst);
2613 Act := First_Entity (Inst);
2615 while Present (Act) loop
2616 if Ekind (Act) = E_Package then
2618 -- Check for end of actuals list
2620 if Renamed_Object (Act) = Inst then
2623 elsif Present (Associated_Formal_Package (Act))
2624 and then Renamed_Object (Act) = Scop
2626 -- Entity comes from (instance of) formal package
2641 end From_Actual_Package;
2643 -------------------------
2644 -- Known_But_Invisible --
2645 -------------------------
2647 function Known_But_Invisible (E : Entity_Id) return Boolean is
2648 Fname : File_Name_Type;
2651 -- Entities in Standard are always considered to be known
2653 if Sloc (E) <= Standard_Location then
2656 -- An entity that does not come from source is always considered
2657 -- to be unknown, since it is an artifact of code expansion.
2659 elsif not Comes_From_Source (E) then
2662 -- In gnat internal mode, we consider all entities known
2664 elsif GNAT_Mode then
2668 -- Here we have an entity that is not from package Standard, and
2669 -- which comes from Source. See if it comes from an internal file.
2671 Fname := Unit_File_Name (Get_Source_Unit (E));
2673 -- Case of from internal file
2675 if Is_Internal_File_Name (Fname) then
2677 -- Private part entities in internal files are never considered
2678 -- to be known to the writer of normal application code.
2680 if Is_Hidden (E) then
2684 -- Entities from System packages other than System and
2685 -- System.Storage_Elements are not considered to be known.
2686 -- System.Auxxxx files are also considered known to the user.
2688 -- Should refine this at some point to generally distinguish
2689 -- between known and unknown internal files ???
2691 Get_Name_String (Fname);
2696 Name_Buffer (1 .. 2) /= "s-"
2698 Name_Buffer (3 .. 8) = "stoele"
2700 Name_Buffer (3 .. 5) = "aux";
2702 -- If not an internal file, then entity is definitely known,
2703 -- even if it is in a private part (the message generated will
2704 -- note that it is in a private part)
2709 end Known_But_Invisible;
2715 procedure Nvis_Messages is
2716 Comp_Unit : Node_Id;
2718 Hidden : Boolean := False;
2722 -- Ada 2005 (AI-262): Generate a precise error concerning the
2723 -- Beaujolais effect that was previously detected
2725 if Nvis_Is_Private_Subprg then
2727 pragma Assert (Nkind (E2) = N_Defining_Identifier
2728 and then Ekind (E2) = E_Function
2729 and then Scope (E2) = Standard_Standard
2730 and then Has_Private_With (E2));
2732 -- Find the sloc corresponding to the private with'ed unit
2734 Comp_Unit := Cunit (Current_Sem_Unit);
2735 Item := First (Context_Items (Comp_Unit));
2736 Error_Msg_Sloc := No_Location;
2738 while Present (Item) loop
2739 if Nkind (Item) = N_With_Clause
2740 and then Private_Present (Item)
2741 and then Entity (Name (Item)) = E2
2743 Error_Msg_Sloc := Sloc (Item);
2750 pragma Assert (Error_Msg_Sloc /= No_Location);
2752 Error_Msg_N ("(Ada 2005): hidden by private with clause #", N);
2756 Undefined (Nvis => True);
2760 -- First loop does hidden declarations
2763 while Present (Ent) loop
2764 if Is_Potentially_Use_Visible (Ent) then
2767 Error_Msg_N ("multiple use clauses cause hiding!", N);
2771 Error_Msg_Sloc := Sloc (Ent);
2772 Error_Msg_N ("hidden declaration#!", N);
2775 Ent := Homonym (Ent);
2778 -- If we found hidden declarations, then that's enough, don't
2779 -- bother looking for non-visible declarations as well.
2785 -- Second loop does non-directly visible declarations
2788 while Present (Ent) loop
2789 if not Is_Potentially_Use_Visible (Ent) then
2791 -- Do not bother the user with unknown entities
2793 if not Known_But_Invisible (Ent) then
2797 Error_Msg_Sloc := Sloc (Ent);
2799 -- Output message noting that there is a non-visible
2800 -- declaration, distinguishing the private part case.
2802 if Is_Hidden (Ent) then
2803 Error_Msg_N ("non-visible (private) declaration#!", N);
2805 Error_Msg_N ("non-visible declaration#!", N);
2807 if Is_Compilation_Unit (Ent)
2809 Nkind (Parent (Parent (N))) = N_Use_Package_Clause
2812 ("\possibly missing with_clause for&", N, Ent);
2816 -- Set entity and its containing package as referenced. We
2817 -- can't be sure of this, but this seems a better choice
2818 -- to avoid unused entity messages.
2820 if Comes_From_Source (Ent) then
2821 Set_Referenced (Ent);
2822 Set_Referenced (Cunit_Entity (Get_Source_Unit (Ent)));
2827 Ent := Homonym (Ent);
2837 procedure Undefined (Nvis : Boolean) is
2838 Emsg : Error_Msg_Id;
2841 -- We should never find an undefined internal name. If we do, then
2842 -- see if we have previous errors. If so, ignore on the grounds that
2843 -- it is probably a cascaded message (e.g. a block label from a badly
2844 -- formed block). If no previous errors, then we have a real internal
2845 -- error of some kind so raise an exception.
2847 if Is_Internal_Name (Chars (N)) then
2848 if Total_Errors_Detected /= 0 then
2851 raise Program_Error;
2855 -- A very specialized error check, if the undefined variable is
2856 -- a case tag, and the case type is an enumeration type, check
2857 -- for a possible misspelling, and if so, modify the identifier
2859 -- Named aggregate should also be handled similarly ???
2861 if Nkind (N) = N_Identifier
2862 and then Nkind (Parent (N)) = N_Case_Statement_Alternative
2864 Get_Name_String (Chars (N));
2867 Case_Str : constant String := Name_Buffer (1 .. Name_Len);
2868 Case_Stm : constant Node_Id := Parent (Parent (N));
2869 Case_Typ : constant Entity_Id := Etype (Expression (Case_Stm));
2870 Case_Rtp : constant Entity_Id := Root_Type (Case_Typ);
2875 if Is_Enumeration_Type (Case_Typ)
2876 and then Case_Rtp /= Standard_Character
2877 and then Case_Rtp /= Standard_Wide_Character
2878 and then Case_Rtp /= Standard_Wide_Wide_Character
2880 Lit := First_Literal (Case_Typ);
2881 Get_Name_String (Chars (Lit));
2883 if Chars (Lit) /= Chars (N)
2884 and then Is_Bad_Spelling_Of
2885 (Case_Str, Name_Buffer (1 .. Name_Len))
2887 Error_Msg_Node_2 := Lit;
2889 ("& is undefined, assume misspelling of &", N);
2890 Rewrite (N, New_Occurrence_Of (Lit, Sloc (N)));
2894 Lit := Next_Literal (Lit);
2899 -- Normal processing
2901 Set_Entity (N, Any_Id);
2902 Set_Etype (N, Any_Type);
2904 -- We use the table Urefs to keep track of entities for which we
2905 -- have issued errors for undefined references. Multiple errors
2906 -- for a single name are normally suppressed, however we modify
2907 -- the error message to alert the programmer to this effect.
2909 for J in Urefs.First .. Urefs.Last loop
2910 if Chars (N) = Chars (Urefs.Table (J).Node) then
2911 if Urefs.Table (J).Err /= No_Error_Msg
2912 and then Sloc (N) /= Urefs.Table (J).Loc
2914 Error_Msg_Node_1 := Urefs.Table (J).Node;
2916 if Urefs.Table (J).Nvis then
2917 Change_Error_Text (Urefs.Table (J).Err,
2918 "& is not visible (more references follow)");
2920 Change_Error_Text (Urefs.Table (J).Err,
2921 "& is undefined (more references follow)");
2924 Urefs.Table (J).Err := No_Error_Msg;
2927 -- Although we will set Msg False, and thus suppress the
2928 -- message, we also set Error_Posted True, to avoid any
2929 -- cascaded messages resulting from the undefined reference.
2932 Set_Error_Posted (N, True);
2937 -- If entry not found, this is first undefined occurrence
2940 Error_Msg_N ("& is not visible!", N);
2944 Error_Msg_N ("& is undefined!", N);
2947 -- A very bizarre special check, if the undefined identifier
2948 -- is put or put_line, then add a special error message (since
2949 -- this is a very common error for beginners to make).
2951 if Chars (N) = Name_Put or else Chars (N) = Name_Put_Line then
2952 Error_Msg_N ("\possible missing with of 'Text_'I'O!", N);
2955 -- Now check for possible misspellings
2957 Get_Name_String (Chars (N));
2961 Ematch : Entity_Id := Empty;
2963 Last_Name_Id : constant Name_Id :=
2964 Name_Id (Nat (First_Name_Id) +
2965 Name_Entries_Count - 1);
2967 S : constant String (1 .. Name_Len) :=
2968 Name_Buffer (1 .. Name_Len);
2971 for N in First_Name_Id .. Last_Name_Id loop
2972 E := Get_Name_Entity_Id (N);
2975 and then (Is_Immediately_Visible (E)
2977 Is_Potentially_Use_Visible (E))
2979 Get_Name_String (N);
2981 if Is_Bad_Spelling_Of
2982 (Name_Buffer (1 .. Name_Len), S)
2990 if Present (Ematch) then
2991 Error_Msg_NE ("\possible misspelling of&", N, Ematch);
2996 -- Make entry in undefined references table unless the full
2997 -- errors switch is set, in which case by refraining from
2998 -- generating the table entry, we guarantee that we get an
2999 -- error message for every undefined reference.
3001 if not All_Errors_Mode then
3002 Urefs.Increment_Last;
3003 Urefs.Table (Urefs.Last).Node := N;
3004 Urefs.Table (Urefs.Last).Err := Emsg;
3005 Urefs.Table (Urefs.Last).Nvis := Nvis;
3006 Urefs.Table (Urefs.Last).Loc := Sloc (N);
3012 -- Start of processing for Find_Direct_Name
3015 -- If the entity pointer is already set, this is an internal node, or
3016 -- a node that is analyzed more than once, after a tree modification.
3017 -- In such a case there is no resolution to perform, just set the type.
3019 if Present (Entity (N)) then
3020 if Is_Type (Entity (N)) then
3021 Set_Etype (N, Entity (N));
3025 Entyp : constant Entity_Id := Etype (Entity (N));
3028 -- One special case here. If the Etype field is already set,
3029 -- and references the packed array type corresponding to the
3030 -- etype of the referenced entity, then leave it alone. This
3031 -- happens for trees generated from Exp_Pakd, where expressions
3032 -- can be deliberately "mis-typed" to the packed array type.
3034 if Is_Array_Type (Entyp)
3035 and then Is_Packed (Entyp)
3036 and then Present (Etype (N))
3037 and then Etype (N) = Packed_Array_Type (Entyp)
3041 -- If not that special case, then just reset the Etype
3044 Set_Etype (N, Etype (Entity (N)));
3052 -- Here if Entity pointer was not set, we need full visibility analysis
3053 -- First we generate debugging output if the debug E flag is set.
3055 if Debug_Flag_E then
3056 Write_Str ("Looking for ");
3057 Write_Name (Chars (N));
3061 Homonyms := Current_Entity (N);
3062 Nvis_Entity := False;
3065 while Present (E) loop
3067 -- If entity is immediately visible or potentially use
3068 -- visible, then process the entity and we are done.
3070 if Is_Immediately_Visible (E) then
3071 goto Immediately_Visible_Entity;
3073 elsif Is_Potentially_Use_Visible (E) then
3074 goto Potentially_Use_Visible_Entity;
3076 -- Note if a known but invisible entity encountered
3078 elsif Known_But_Invisible (E) then
3079 Nvis_Entity := True;
3082 -- Move to next entity in chain and continue search
3087 -- If no entries on homonym chain that were potentially visible,
3088 -- and no entities reasonably considered as non-visible, then
3089 -- we have a plain undefined reference, with no additional
3090 -- explanation required!
3092 if not Nvis_Entity then
3093 Undefined (Nvis => False);
3095 -- Otherwise there is at least one entry on the homonym chain that
3096 -- is reasonably considered as being known and non-visible.
3104 -- Processing for a potentially use visible entry found. We must search
3105 -- the rest of the homonym chain for two reasons. First, if there is a
3106 -- directly visible entry, then none of the potentially use-visible
3107 -- entities are directly visible (RM 8.4(10)). Second, we need to check
3108 -- for the case of multiple potentially use-visible entries hiding one
3109 -- another and as a result being non-directly visible (RM 8.4(11)).
3111 <<Potentially_Use_Visible_Entity>> declare
3112 Only_One_Visible : Boolean := True;
3113 All_Overloadable : Boolean := Is_Overloadable (E);
3118 while Present (E2) loop
3119 if Is_Immediately_Visible (E2) then
3121 -- If the use-visible entity comes from the actual for a
3122 -- formal package, it hides a directly visible entity from
3123 -- outside the instance.
3125 if From_Actual_Package (E)
3126 and then Scope_Depth (E2) < Scope_Depth (Inst)
3131 goto Immediately_Visible_Entity;
3134 elsif Is_Potentially_Use_Visible (E2) then
3135 Only_One_Visible := False;
3136 All_Overloadable := All_Overloadable and Is_Overloadable (E2);
3138 -- Ada 2005 (AI-262): Protect against a form of Beujolais effect
3139 -- that can occurr in private_with clauses. Example:
3142 -- private with B; package A is
3143 -- package C is function B return Integer;
3145 -- V1 : Integer := B;
3146 -- private function B return Integer;
3147 -- V2 : Integer := B;
3150 -- V1 resolves to A.B, but V2 resolves to library unit B
3152 elsif Ekind (E2) = E_Function
3153 and then Scope (E2) = Standard_Standard
3154 and then Has_Private_With (E2)
3156 Only_One_Visible := False;
3157 All_Overloadable := False;
3158 Nvis_Is_Private_Subprg := True;
3165 -- On falling through this loop, we have checked that there are no
3166 -- immediately visible entities. Only_One_Visible is set if exactly
3167 -- one potentially use visible entity exists. All_Overloadable is
3168 -- set if all the potentially use visible entities are overloadable.
3169 -- The condition for legality is that either there is one potentially
3170 -- use visible entity, or if there is more than one, then all of them
3171 -- are overloadable.
3173 if Only_One_Visible or All_Overloadable then
3176 -- If there is more than one potentially use-visible entity and at
3177 -- least one of them non-overloadable, we have an error (RM 8.4(11).
3178 -- Note that E points to the first such entity on the homonym list.
3179 -- Special case: if one of the entities is declared in an actual
3180 -- package, it was visible in the generic, and takes precedence over
3181 -- other entities that are potentially use-visible. Same if it is
3182 -- declared in a local instantiation of the current instance.
3186 Inst := Current_Scope;
3188 -- Find current instance
3190 while Present (Inst)
3191 and then Inst /= Standard_Standard
3193 if Is_Generic_Instance (Inst) then
3197 Inst := Scope (Inst);
3202 while Present (E2) loop
3203 if From_Actual_Package (E2)
3205 (Is_Generic_Instance (Scope (E2))
3206 and then Scope_Depth (Scope (E2)) > Scope_Depth (Inst))
3219 Is_Predefined_File_Name (Unit_File_Name (Current_Sem_Unit))
3221 -- A use-clause in the body of a system file creates a
3222 -- conflict with some entity in a user scope, while rtsfind
3223 -- is active. Keep only the entity that comes from another
3227 while Present (E2) loop
3228 if Is_Predefined_File_Name
3229 (Unit_File_Name (Get_Source_Unit (Sloc (E2))))
3238 -- Entity must exist because predefined unit is correct.
3240 raise Program_Error;
3249 -- Come here with E set to the first immediately visible entity on
3250 -- the homonym chain. This is the one we want unless there is another
3251 -- immediately visible entity further on in the chain for a more
3252 -- inner scope (RM 8.3(8)).
3254 <<Immediately_Visible_Entity>> declare
3259 -- Find scope level of initial entity. When compiling through
3260 -- Rtsfind, the previous context is not completely invisible, and
3261 -- an outer entity may appear on the chain, whose scope is below
3262 -- the entry for Standard that delimits the current scope stack.
3263 -- Indicate that the level for this spurious entry is outside of
3264 -- the current scope stack.
3266 Level := Scope_Stack.Last;
3268 Scop := Scope_Stack.Table (Level).Entity;
3269 exit when Scop = Scope (E);
3271 exit when Scop = Standard_Standard;
3274 -- Now search remainder of homonym chain for more inner entry
3275 -- If the entity is Standard itself, it has no scope, and we
3276 -- compare it with the stack entry directly.
3279 while Present (E2) loop
3280 if Is_Immediately_Visible (E2) then
3281 for J in Level + 1 .. Scope_Stack.Last loop
3282 if Scope_Stack.Table (J).Entity = Scope (E2)
3283 or else Scope_Stack.Table (J).Entity = E2
3295 -- At the end of that loop, E is the innermost immediately
3296 -- visible entity, so we are all set.
3299 -- Come here with entity found, and stored in E
3303 if Comes_From_Source (N)
3304 and then Is_Remote_Access_To_Subprogram_Type (E)
3305 and then Expander_Active
3306 and then Get_PCS_Name /= Name_No_DSA
3309 New_Occurrence_Of (Equivalent_Type (E), Sloc (N)));
3314 -- Why no Style_Check here???
3319 Set_Etype (N, Get_Full_View (Etype (E)));
3322 if Debug_Flag_E then
3323 Write_Str (" found ");
3324 Write_Entity_Info (E, " ");
3327 -- If the Ekind of the entity is Void, it means that all homonyms
3328 -- are hidden from all visibility (RM 8.3(5,14-20)). However, this
3329 -- test is skipped if the current scope is a record and the name is
3330 -- a pragma argument expression (case of Atomic and Volatile pragmas
3331 -- and possibly other similar pragmas added later, which are allowed
3332 -- to reference components in the current record).
3334 if Ekind (E) = E_Void
3336 (not Is_Record_Type (Current_Scope)
3337 or else Nkind (Parent (N)) /= N_Pragma_Argument_Association)
3339 Premature_Usage (N);
3341 -- If the entity is overloadable, collect all interpretations
3342 -- of the name for subsequent overload resolution. We optimize
3343 -- a bit here to do this only if we have an overloadable entity
3344 -- that is not on its own on the homonym chain.
3346 elsif Is_Overloadable (E)
3347 and then (Present (Homonym (E)) or else Current_Entity (N) /= E)
3349 Collect_Interps (N);
3351 -- If no homonyms were visible, the entity is unambiguous
3353 if not Is_Overloaded (N) then
3354 Generate_Reference (E, N);
3357 -- Case of non-overloadable entity, set the entity providing that
3358 -- we do not have the case of a discriminant reference within a
3359 -- default expression. Such references are replaced with the
3360 -- corresponding discriminal, which is the formal corresponding to
3361 -- to the discriminant in the initialization procedure.
3364 -- Entity is unambiguous, indicate that it is referenced here
3365 -- One slightly odd case is that we do not want to set the
3366 -- Referenced flag if the entity is a label, and the identifier
3367 -- is the label in the source, since this is not a reference
3368 -- from the point of view of the user
3370 if Nkind (Parent (N)) = N_Label then
3372 R : constant Boolean := Referenced (E);
3375 Generate_Reference (E, N);
3376 Set_Referenced (E, R);
3379 -- Normal case, not a label. Generate reference
3382 Generate_Reference (E, N);
3385 -- Set Entity, with style check if need be. If this is a
3386 -- discriminant reference, it must be replaced by the
3387 -- corresponding discriminal, that is to say the parameter
3388 -- of the initialization procedure that corresponds to the
3389 -- discriminant. If this replacement is being performed, there
3390 -- is no style check to perform.
3392 -- This replacement must not be done if we are currently
3393 -- processing a generic spec or body, because the discriminal
3394 -- has not been not generated in this case.
3396 if not In_Default_Expression
3397 or else Ekind (E) /= E_Discriminant
3398 or else Inside_A_Generic
3400 Set_Entity_With_Style_Check (N, E);
3402 -- The replacement is not done either for a task discriminant that
3403 -- appears in a default expression of an entry parameter. See
3404 -- Expand_Discriminant in exp_ch2 for details on their handling.
3406 elsif Is_Concurrent_Type (Scope (E)) then
3408 P : Node_Id := Parent (N);
3412 and then Nkind (P) /= N_Parameter_Specification
3413 and then Nkind (P) /= N_Component_Declaration
3419 and then Nkind (P) = N_Parameter_Specification
3423 Set_Entity (N, Discriminal (E));
3427 -- Otherwise, this is a discriminant in a context in which
3428 -- it is a reference to the corresponding parameter of the
3429 -- init proc for the enclosing type.
3432 Set_Entity (N, Discriminal (E));
3436 end Find_Direct_Name;
3438 ------------------------
3439 -- Find_Expanded_Name --
3440 ------------------------
3442 -- This routine searches the homonym chain of the entity until it finds
3443 -- an entity declared in the scope denoted by the prefix. If the entity
3444 -- is private, it may nevertheless be immediately visible, if we are in
3445 -- the scope of its declaration.
3447 procedure Find_Expanded_Name (N : Node_Id) is
3448 Selector : constant Node_Id := Selector_Name (N);
3449 Candidate : Entity_Id := Empty;
3455 P_Name := Entity (Prefix (N));
3458 -- If the prefix is a renamed package, look for the entity
3459 -- in the original package.
3461 if Ekind (P_Name) = E_Package
3462 and then Present (Renamed_Object (P_Name))
3464 P_Name := Renamed_Object (P_Name);
3466 -- Rewrite node with entity field pointing to renamed object
3468 Rewrite (Prefix (N), New_Copy (Prefix (N)));
3469 Set_Entity (Prefix (N), P_Name);
3471 -- If the prefix is an object of a concurrent type, look for
3472 -- the entity in the associated task or protected type.
3474 elsif Is_Concurrent_Type (Etype (P_Name)) then
3475 P_Name := Etype (P_Name);
3478 Id := Current_Entity (Selector);
3480 while Present (Id) loop
3482 if Scope (Id) = P_Name then
3485 if Is_Child_Unit (Id) then
3486 exit when Is_Visible_Child_Unit (Id)
3487 or else Is_Immediately_Visible (Id);
3490 exit when not Is_Hidden (Id)
3491 or else Is_Immediately_Visible (Id);
3499 and then (Ekind (P_Name) = E_Procedure
3501 Ekind (P_Name) = E_Function)
3502 and then Is_Generic_Instance (P_Name)
3504 -- Expanded name denotes entity in (instance of) generic subprogram.
3505 -- The entity may be in the subprogram instance, or may denote one of
3506 -- the formals, which is declared in the enclosing wrapper package.
3508 P_Name := Scope (P_Name);
3510 Id := Current_Entity (Selector);
3511 while Present (Id) loop
3512 exit when Scope (Id) = P_Name;
3517 if No (Id) or else Chars (Id) /= Chars (Selector) then
3518 Set_Etype (N, Any_Type);
3520 -- If we are looking for an entity defined in System, try to
3521 -- find it in the child package that may have been provided as
3522 -- an extension to System. The Extend_System pragma will have
3523 -- supplied the name of the extension, which may have to be loaded.
3525 if Chars (P_Name) = Name_System
3526 and then Scope (P_Name) = Standard_Standard
3527 and then Present (System_Extend_Unit)
3528 and then Present_System_Aux (N)
3530 Set_Entity (Prefix (N), System_Aux_Id);
3531 Find_Expanded_Name (N);
3534 elsif Nkind (Selector) = N_Operator_Symbol
3535 and then Has_Implicit_Operator (N)
3537 -- There is an implicit instance of the predefined operator in
3538 -- the given scope. The operator entity is defined in Standard.
3539 -- Has_Implicit_Operator makes the node into an Expanded_Name.
3543 elsif Nkind (Selector) = N_Character_Literal
3544 and then Has_Implicit_Character_Literal (N)
3546 -- If there is no literal defined in the scope denoted by the
3547 -- prefix, the literal may belong to (a type derived from)
3548 -- Standard_Character, for which we have no explicit literals.
3553 -- If the prefix is a single concurrent object, use its
3554 -- name in the error message, rather than that of the
3557 if Is_Concurrent_Type (P_Name)
3558 and then Is_Internal_Name (Chars (P_Name))
3560 Error_Msg_Node_2 := Entity (Prefix (N));
3562 Error_Msg_Node_2 := P_Name;
3565 if P_Name = System_Aux_Id then
3566 P_Name := Scope (P_Name);
3567 Set_Entity (Prefix (N), P_Name);
3570 if Present (Candidate) then
3572 if Is_Child_Unit (Candidate) then
3574 ("missing with_clause for child unit &", Selector);
3576 Error_Msg_NE ("& is not a visible entity of&", N, Selector);
3580 -- Within the instantiation of a child unit, the prefix may
3581 -- denote the parent instance, but the selector has the
3582 -- name of the original child. Find whether we are within
3583 -- the corresponding instance, and get the proper entity, which
3584 -- can only be an enclosing scope.
3587 and then In_Open_Scopes (P_Name)
3588 and then Is_Generic_Instance (P_Name)
3591 S : Entity_Id := Current_Scope;
3595 for J in reverse 0 .. Scope_Stack.Last loop
3596 S := Scope_Stack.Table (J).Entity;
3598 exit when S = Standard_Standard;
3600 if Ekind (S) = E_Function
3601 or else Ekind (S) = E_Package
3602 or else Ekind (S) = E_Procedure
3604 P := Generic_Parent (Specification
3605 (Unit_Declaration_Node (S)));
3608 and then Chars (Scope (P)) = Chars (O_Name)
3609 and then Chars (P) = Chars (Selector)
3620 if Chars (P_Name) = Name_Ada
3621 and then Scope (P_Name) = Standard_Standard
3623 Error_Msg_Node_2 := Selector;
3624 Error_Msg_NE ("missing with for `&.&`", N, P_Name);
3626 -- If this is a selection from a dummy package, then
3627 -- suppress the error message, of course the entity
3628 -- is missing if the package is missing!
3630 elsif Sloc (Error_Msg_Node_2) = No_Location then
3633 -- Here we have the case of an undefined component
3637 Error_Msg_NE ("& not declared in&", N, Selector);
3639 -- Check for misspelling of some entity in prefix
3641 Id := First_Entity (P_Name);
3642 Get_Name_String (Chars (Selector));
3645 S : constant String (1 .. Name_Len) :=
3646 Name_Buffer (1 .. Name_Len);
3648 while Present (Id) loop
3649 Get_Name_String (Chars (Id));
3650 if Is_Bad_Spelling_Of
3651 (Name_Buffer (1 .. Name_Len), S)
3652 and then not Is_Internal_Name (Chars (Id))
3655 ("possible misspelling of&", Selector, Id);
3663 -- Specialize the message if this may be an instantiation
3664 -- of a child unit that was not mentioned in the context.
3666 if Nkind (Parent (N)) = N_Package_Instantiation
3667 and then Is_Generic_Instance (Entity (Prefix (N)))
3668 and then Is_Compilation_Unit
3669 (Generic_Parent (Parent (Entity (Prefix (N)))))
3672 ("\possible missing with clause on child unit&",
3683 if Comes_From_Source (N)
3684 and then Is_Remote_Access_To_Subprogram_Type (Id)
3685 and then Present (Equivalent_Type (Id))
3687 -- If we are not actually generating distribution code (i.e.
3688 -- the current PCS is the dummy non-distributed version), then
3689 -- the Equivalent_Type will be missing, and Id should be treated
3690 -- as a regular access-to-subprogram type.
3692 Id := Equivalent_Type (Id);
3693 Set_Chars (Selector, Chars (Id));
3696 -- Ada 2005 (AI-50217): Check usage of entities in limited withed units
3698 if Ekind (P_Name) = E_Package
3699 and then From_With_Type (P_Name)
3701 if From_With_Type (Id)
3702 or else Is_Type (Id)
3703 or else Ekind (Id) = E_Package
3708 ("limited withed package can only be used to access "
3709 & " incomplete types",
3714 if Is_Task_Type (P_Name)
3715 and then ((Ekind (Id) = E_Entry
3716 and then Nkind (Parent (N)) /= N_Attribute_Reference)
3718 (Ekind (Id) = E_Entry_Family
3720 Nkind (Parent (Parent (N))) /= N_Attribute_Reference))
3722 -- It is an entry call after all, either to the current task
3723 -- (which will deadlock) or to an enclosing task.
3725 Analyze_Selected_Component (N);
3729 Change_Selected_Component_To_Expanded_Name (N);
3731 -- Do style check and generate reference, but skip both steps if this
3732 -- entity has homonyms, since we may not have the right homonym set
3733 -- yet. The proper homonym will be set during the resolve phase.
3735 if Has_Homonym (Id) then
3738 Set_Entity_With_Style_Check (N, Id);
3739 Generate_Reference (Id, N);
3742 if Is_Type (Id) then
3745 Set_Etype (N, Get_Full_View (Etype (Id)));
3748 -- If the Ekind of the entity is Void, it means that all homonyms
3749 -- are hidden from all visibility (RM 8.3(5,14-20)).
3751 if Ekind (Id) = E_Void then
3752 Premature_Usage (N);
3754 elsif Is_Overloadable (Id)
3755 and then Present (Homonym (Id))
3758 H : Entity_Id := Homonym (Id);
3761 while Present (H) loop
3762 if Scope (H) = Scope (Id)
3765 or else Is_Immediately_Visible (H))
3767 Collect_Interps (N);
3774 -- If an extension of System is present, collect possible
3775 -- explicit overloadings declared in the extension.
3777 if Chars (P_Name) = Name_System
3778 and then Scope (P_Name) = Standard_Standard
3779 and then Present (System_Extend_Unit)
3780 and then Present_System_Aux (N)
3782 H := Current_Entity (Id);
3784 while Present (H) loop
3785 if Scope (H) = System_Aux_Id then
3786 Add_One_Interp (N, H, Etype (H));
3795 if Nkind (Selector_Name (N)) = N_Operator_Symbol
3796 and then Scope (Id) /= Standard_Standard
3798 -- In addition to user-defined operators in the given scope,
3799 -- there may be an implicit instance of the predefined
3800 -- operator. The operator (defined in Standard) is found
3801 -- in Has_Implicit_Operator, and added to the interpretations.
3802 -- Procedure Add_One_Interp will determine which hides which.
3804 if Has_Implicit_Operator (N) then
3808 end Find_Expanded_Name;
3810 -------------------------
3811 -- Find_Renamed_Entity --
3812 -------------------------
3814 function Find_Renamed_Entity
3818 Is_Actual : Boolean := False) return Entity_Id
3821 I1 : Interp_Index := 0; -- Suppress junk warnings
3827 function Enclosing_Instance return Entity_Id;
3828 -- If the renaming determines the entity for the default of a formal
3829 -- subprogram nested within another instance, choose the innermost
3830 -- candidate. This is because if the formal has a box, and we are within
3831 -- an enclosing instance where some candidate interpretations are local
3832 -- to this enclosing instance, we know that the default was properly
3833 -- resolved when analyzing the generic, so we prefer the local
3834 -- candidates to those that are external. This is not always the case
3835 -- but is a reasonable heuristic on the use of nested generics.
3836 -- The proper solution requires a full renaming model.
3838 function Within (Inner, Outer : Entity_Id) return Boolean;
3839 -- Determine whether a candidate subprogram is defined within
3840 -- the enclosing instance. If yes, it has precedence over outer
3843 function Is_Visible_Operation (Op : Entity_Id) return Boolean;
3844 -- If the renamed entity is an implicit operator, check whether it is
3845 -- visible because its operand type is properly visible. This
3846 -- check applies to explicit renamed entities that appear in the
3847 -- source in a renaming declaration or a formal subprogram instance,
3848 -- but not to default generic actuals with a name.
3850 ------------------------
3851 -- Enclosing_Instance --
3852 ------------------------
3854 function Enclosing_Instance return Entity_Id is
3858 if not Is_Generic_Instance (Current_Scope)
3859 and then not Is_Actual
3864 S := Scope (Current_Scope);
3866 while S /= Standard_Standard loop
3868 if Is_Generic_Instance (S) then
3876 end Enclosing_Instance;
3878 --------------------------
3879 -- Is_Visible_Operation --
3880 --------------------------
3882 function Is_Visible_Operation (Op : Entity_Id) return Boolean is
3888 if Ekind (Op) /= E_Operator
3889 or else Scope (Op) /= Standard_Standard
3890 or else (In_Instance
3893 or else Present (Enclosing_Instance)))
3898 -- For a fixed point type operator, check the resulting type,
3899 -- because it may be a mixed mode integer * fixed operation.
3901 if Present (Next_Formal (First_Formal (New_S)))
3902 and then Is_Fixed_Point_Type (Etype (New_S))
3904 Typ := Etype (New_S);
3906 Typ := Etype (First_Formal (New_S));
3909 Btyp := Base_Type (Typ);
3911 if Nkind (Nam) /= N_Expanded_Name then
3912 return (In_Open_Scopes (Scope (Btyp))
3913 or else Is_Potentially_Use_Visible (Btyp)
3914 or else In_Use (Btyp)
3915 or else In_Use (Scope (Btyp)));
3918 Scop := Entity (Prefix (Nam));
3920 if Ekind (Scop) = E_Package
3921 and then Present (Renamed_Object (Scop))
3923 Scop := Renamed_Object (Scop);
3926 -- Operator is visible if prefix of expanded name denotes
3927 -- scope of type, or else type type is defined in System_Aux
3928 -- and the prefix denotes System.
3930 return Scope (Btyp) = Scop
3931 or else (Scope (Btyp) = System_Aux_Id
3932 and then Scope (Scope (Btyp)) = Scop);
3935 end Is_Visible_Operation;
3941 function Within (Inner, Outer : Entity_Id) return Boolean is
3942 Sc : Entity_Id := Scope (Inner);
3945 while Sc /= Standard_Standard loop
3957 function Report_Overload return Entity_Id;
3958 -- List possible interpretations, and specialize message in the
3959 -- case of a generic actual.
3961 function Report_Overload return Entity_Id is
3965 ("ambiguous actual subprogram&, " &
3966 "possible interpretations: ", N, Nam);
3969 ("ambiguous subprogram, " &
3970 "possible interpretations: ", N);
3973 List_Interps (Nam, N);
3975 end Report_Overload;
3977 -- Start of processing for Find_Renamed_Entry
3981 Candidate_Renaming := Empty;
3983 if not Is_Overloaded (Nam) then
3984 if Entity_Matches_Spec (Entity (Nam), New_S)
3985 and then Is_Visible_Operation (Entity (Nam))
3987 Old_S := Entity (Nam);
3990 Present (First_Formal (Entity (Nam)))
3991 and then Present (First_Formal (New_S))
3992 and then (Base_Type (Etype (First_Formal (Entity (Nam))))
3993 = Base_Type (Etype (First_Formal (New_S))))
3995 Candidate_Renaming := Entity (Nam);
3999 Get_First_Interp (Nam, Ind, It);
4001 while Present (It.Nam) loop
4003 if Entity_Matches_Spec (It.Nam, New_S)
4004 and then Is_Visible_Operation (It.Nam)
4006 if Old_S /= Any_Id then
4008 -- Note: The call to Disambiguate only happens if a
4009 -- previous interpretation was found, in which case I1
4010 -- has received a value.
4012 It1 := Disambiguate (Nam, I1, Ind, Etype (Old_S));
4014 if It1 = No_Interp then
4016 Inst := Enclosing_Instance;
4018 if Present (Inst) then
4020 if Within (It.Nam, Inst) then
4023 elsif Within (Old_S, Inst) then
4027 return Report_Overload;
4031 return Report_Overload;
4045 Present (First_Formal (It.Nam))
4046 and then Present (First_Formal (New_S))
4047 and then (Base_Type (Etype (First_Formal (It.Nam)))
4048 = Base_Type (Etype (First_Formal (New_S))))
4050 Candidate_Renaming := It.Nam;
4053 Get_Next_Interp (Ind, It);
4056 Set_Entity (Nam, Old_S);
4057 Set_Is_Overloaded (Nam, False);
4061 end Find_Renamed_Entity;
4063 -----------------------------
4064 -- Find_Selected_Component --
4065 -----------------------------
4067 procedure Find_Selected_Component (N : Node_Id) is
4068 P : constant Node_Id := Prefix (N);
4071 -- Entity denoted by prefix
4081 if Nkind (P) = N_Error then
4084 -- If the selector already has an entity, the node has been
4085 -- constructed in the course of expansion, and is known to be
4086 -- valid. Do not verify that it is defined for the type (it may
4087 -- be a private component used in the expansion of record equality).
4089 elsif Present (Entity (Selector_Name (N))) then
4092 or else Etype (N) = Any_Type
4095 Sel_Name : constant Node_Id := Selector_Name (N);
4096 Selector : constant Entity_Id := Entity (Sel_Name);
4100 Set_Etype (Sel_Name, Etype (Selector));
4102 if not Is_Entity_Name (P) then
4106 -- Build an actual subtype except for the first parameter
4107 -- of an init proc, where this actual subtype is by
4108 -- definition incorrect, since the object is uninitialized
4109 -- (and does not even have defined discriminants etc.)
4111 if Is_Entity_Name (P)
4112 and then Ekind (Entity (P)) = E_Function
4114 Nam := New_Copy (P);
4116 if Is_Overloaded (P) then
4117 Save_Interps (P, Nam);
4121 Make_Function_Call (Sloc (P), Name => Nam));
4123 Analyze_Selected_Component (N);
4126 elsif Ekind (Selector) = E_Component
4127 and then (not Is_Entity_Name (P)
4128 or else Chars (Entity (P)) /= Name_uInit)
4131 Build_Actual_Subtype_Of_Component (
4132 Etype (Selector), N);
4137 if No (C_Etype) then
4138 C_Etype := Etype (Selector);
4140 Insert_Action (N, C_Etype);
4141 C_Etype := Defining_Identifier (C_Etype);
4144 Set_Etype (N, C_Etype);
4147 -- If this is the name of an entry or protected operation, and
4148 -- the prefix is an access type, insert an explicit dereference,
4149 -- so that entry calls are treated uniformly.
4151 if Is_Access_Type (Etype (P))
4152 and then Is_Concurrent_Type (Designated_Type (Etype (P)))
4155 New_P : constant Node_Id :=
4156 Make_Explicit_Dereference (Sloc (P),
4157 Prefix => Relocate_Node (P));
4160 Set_Etype (P, Designated_Type (Etype (Prefix (P))));
4164 -- If the selected component appears within a default expression
4165 -- and it has an actual subtype, the pre-analysis has not yet
4166 -- completed its analysis, because Insert_Actions is disabled in
4167 -- that context. Within the init proc of the enclosing type we
4168 -- must complete this analysis, if an actual subtype was created.
4170 elsif Inside_Init_Proc then
4172 Typ : constant Entity_Id := Etype (N);
4173 Decl : constant Node_Id := Declaration_Node (Typ);
4176 if Nkind (Decl) = N_Subtype_Declaration
4177 and then not Analyzed (Decl)
4178 and then Is_List_Member (Decl)
4179 and then No (Parent (Decl))
4182 Insert_Action (N, Decl);
4189 elsif Is_Entity_Name (P) then
4190 P_Name := Entity (P);
4192 -- The prefix may denote an enclosing type which is the completion
4193 -- of an incomplete type declaration.
4195 if Is_Type (P_Name) then
4196 Set_Entity (P, Get_Full_View (P_Name));
4197 Set_Etype (P, Entity (P));
4198 P_Name := Entity (P);
4201 P_Type := Base_Type (Etype (P));
4203 if Debug_Flag_E then
4204 Write_Str ("Found prefix type to be ");
4205 Write_Entity_Info (P_Type, " "); Write_Eol;
4208 -- First check for components of a record object (not the
4209 -- result of a call, which is handled below).
4211 if Is_Appropriate_For_Record (P_Type)
4212 and then not Is_Overloadable (P_Name)
4213 and then not Is_Type (P_Name)
4215 -- Selected component of record. Type checking will validate
4216 -- name of selector.
4218 Analyze_Selected_Component (N);
4220 elsif Is_Appropriate_For_Entry_Prefix (P_Type)
4221 and then not In_Open_Scopes (P_Name)
4222 and then (not Is_Concurrent_Type (Etype (P_Name))
4223 or else not In_Open_Scopes (Etype (P_Name)))
4225 -- Call to protected operation or entry. Type checking is
4226 -- needed on the prefix.
4228 Analyze_Selected_Component (N);
4230 elsif (In_Open_Scopes (P_Name)
4231 and then Ekind (P_Name) /= E_Void
4232 and then not Is_Overloadable (P_Name))
4233 or else (Is_Concurrent_Type (Etype (P_Name))
4234 and then In_Open_Scopes (Etype (P_Name)))
4236 -- Prefix denotes an enclosing loop, block, or task, i.e. an
4237 -- enclosing construct that is not a subprogram or accept.
4239 Find_Expanded_Name (N);
4241 elsif Ekind (P_Name) = E_Package then
4242 Find_Expanded_Name (N);
4244 elsif Is_Overloadable (P_Name) then
4246 -- The subprogram may be a renaming (of an enclosing scope) as
4247 -- in the case of the name of the generic within an instantiation.
4249 if (Ekind (P_Name) = E_Procedure
4250 or else Ekind (P_Name) = E_Function)
4251 and then Present (Alias (P_Name))
4252 and then Is_Generic_Instance (Alias (P_Name))
4254 P_Name := Alias (P_Name);
4257 if Is_Overloaded (P) then
4259 -- The prefix must resolve to a unique enclosing construct
4262 Found : Boolean := False;
4267 Get_First_Interp (P, Ind, It);
4269 while Present (It.Nam) loop
4271 if In_Open_Scopes (It.Nam) then
4274 "prefix must be unique enclosing scope", N);
4275 Set_Entity (N, Any_Id);
4276 Set_Etype (N, Any_Type);
4285 Get_Next_Interp (Ind, It);
4290 if In_Open_Scopes (P_Name) then
4291 Set_Entity (P, P_Name);
4292 Set_Is_Overloaded (P, False);
4293 Find_Expanded_Name (N);
4296 -- If no interpretation as an expanded name is possible, it
4297 -- must be a selected component of a record returned by a
4298 -- function call. Reformat prefix as a function call, the
4299 -- rest is done by type resolution. If the prefix is a
4300 -- procedure or entry, as is P.X; this is an error.
4302 if Ekind (P_Name) /= E_Function
4303 and then (not Is_Overloaded (P)
4305 Nkind (Parent (N)) = N_Procedure_Call_Statement)
4308 -- Prefix may mention a package that is hidden by a local
4309 -- declaration: let the user know. Scan the full homonym
4310 -- chain, the candidate package may be anywhere on it.
4312 if Present (Homonym (Current_Entity (P_Name))) then
4314 P_Name := Current_Entity (P_Name);
4316 while Present (P_Name) loop
4317 exit when Ekind (P_Name) = E_Package;
4318 P_Name := Homonym (P_Name);
4321 if Present (P_Name) then
4322 Error_Msg_Sloc := Sloc (Entity (Prefix (N)));
4325 ("package& is hidden by declaration#",
4328 Set_Entity (Prefix (N), P_Name);
4329 Find_Expanded_Name (N);
4332 P_Name := Entity (Prefix (N));
4337 ("invalid prefix in selected component&", N, P_Name);
4338 Change_Selected_Component_To_Expanded_Name (N);
4339 Set_Entity (N, Any_Id);
4340 Set_Etype (N, Any_Type);
4343 Nam := New_Copy (P);
4344 Save_Interps (P, Nam);
4346 Make_Function_Call (Sloc (P), Name => Nam));
4348 Analyze_Selected_Component (N);
4352 -- Remaining cases generate various error messages
4355 -- Format node as expanded name, to avoid cascaded errors
4357 Change_Selected_Component_To_Expanded_Name (N);
4358 Set_Entity (N, Any_Id);
4359 Set_Etype (N, Any_Type);
4361 -- Issue error message, but avoid this if error issued already.
4362 -- Use identifier of prefix if one is available.
4364 if P_Name = Any_Id then
4367 elsif Ekind (P_Name) = E_Void then
4368 Premature_Usage (P);
4370 elsif Nkind (P) /= N_Attribute_Reference then
4372 "invalid prefix in selected component&", P);
4374 if Is_Access_Type (P_Type)
4375 and then Ekind (Designated_Type (P_Type)) = E_Incomplete_Type
4378 ("\dereference must not be of an incomplete type " &
4379 "('R'M 3.10.1)", P);
4384 "invalid prefix in selected component", P);
4389 -- If prefix is not the name of an entity, it must be an expression,
4390 -- whose type is appropriate for a record. This is determined by
4393 Analyze_Selected_Component (N);
4395 end Find_Selected_Component;
4401 procedure Find_Type (N : Node_Id) is
4411 elsif Nkind (N) = N_Attribute_Reference then
4413 -- Class attribute. This is only valid in Ada 95 mode, but we don't
4414 -- do a check, since the tagged type referenced could only exist if
4415 -- we were in 95 mode when it was declared (or, if we were in Ada
4416 -- 83 mode, then an error message would already have been issued).
4418 if Attribute_Name (N) = Name_Class then
4419 Check_Restriction (No_Dispatch, N);
4420 Find_Type (Prefix (N));
4422 -- Propagate error from bad prefix
4424 if Etype (Prefix (N)) = Any_Type then
4425 Set_Entity (N, Any_Type);
4426 Set_Etype (N, Any_Type);
4430 T := Base_Type (Entity (Prefix (N)));
4432 -- Case of non-tagged type
4434 if not Is_Tagged_Type (T) then
4435 if Ekind (T) = E_Incomplete_Type then
4437 -- It is legal to denote the class type of an incomplete
4438 -- type. The full type will have to be tagged, of course.
4440 Set_Is_Tagged_Type (T);
4441 Make_Class_Wide_Type (T);
4442 Set_Entity (N, Class_Wide_Type (T));
4443 Set_Etype (N, Class_Wide_Type (T));
4445 elsif Ekind (T) = E_Private_Type
4446 and then not Is_Generic_Type (T)
4447 and then In_Private_Part (Scope (T))
4449 -- The Class attribute can be applied to an untagged
4450 -- private type fulfilled by a tagged type prior to
4451 -- the full type declaration (but only within the
4452 -- parent package's private part). Create the class-wide
4453 -- type now and check that the full type is tagged
4454 -- later during its analysis. Note that we do not
4455 -- mark the private type as tagged, unlike the case
4456 -- of incomplete types, because the type must still
4457 -- appear untagged to outside units.
4459 if not Present (Class_Wide_Type (T)) then
4460 Make_Class_Wide_Type (T);
4463 Set_Entity (N, Class_Wide_Type (T));
4464 Set_Etype (N, Class_Wide_Type (T));
4467 -- Should we introduce a type Any_Tagged and use
4468 -- Wrong_Type here, it would be a bit more consistent???
4471 ("tagged type required, found}",
4472 Prefix (N), First_Subtype (T));
4473 Set_Entity (N, Any_Type);
4477 -- Case of tagged type
4480 C := Class_Wide_Type (Entity (Prefix (N)));
4481 Set_Entity_With_Style_Check (N, C);
4482 Generate_Reference (C, N);
4486 -- Base attribute, not allowed in Ada 83
4488 elsif Attribute_Name (N) = Name_Base then
4489 if Ada_Version = Ada_83 and then Comes_From_Source (N) then
4491 ("(Ada 83) Base attribute not allowed in subtype mark", N);
4494 Find_Type (Prefix (N));
4495 Typ := Entity (Prefix (N));
4497 if Ada_Version >= Ada_95
4498 and then not Is_Scalar_Type (Typ)
4499 and then not Is_Generic_Type (Typ)
4502 ("prefix of Base attribute must be scalar type",
4505 elsif Sloc (Typ) = Standard_Location
4506 and then Base_Type (Typ) = Typ
4507 and then Warn_On_Redundant_Constructs
4510 ("?redudant attribute, & is its own base type", N, Typ);
4513 T := Base_Type (Typ);
4515 -- Rewrite attribute reference with type itself (see similar
4516 -- processing in Analyze_Attribute, case Base). Preserve
4517 -- prefix if present, for other legality checks.
4519 if Nkind (Prefix (N)) = N_Expanded_Name then
4521 Make_Expanded_Name (Sloc (N),
4522 Chars => Chars (Entity (N)),
4523 Prefix => New_Copy (Prefix (Prefix (N))),
4525 New_Reference_To (Entity (N), Sloc (N))));
4529 New_Reference_To (Entity (N), Sloc (N)));
4536 -- All other attributes are invalid in a subtype mark
4539 Error_Msg_N ("invalid attribute in subtype mark", N);
4545 if Is_Entity_Name (N) then
4546 T_Name := Entity (N);
4548 Error_Msg_N ("subtype mark required in this context", N);
4549 Set_Etype (N, Any_Type);
4553 if T_Name = Any_Id or else Etype (N) = Any_Type then
4555 -- Undefined id. Make it into a valid type
4557 Set_Entity (N, Any_Type);
4559 elsif not Is_Type (T_Name)
4560 and then T_Name /= Standard_Void_Type
4562 Error_Msg_Sloc := Sloc (T_Name);
4563 Error_Msg_N ("subtype mark required in this context", N);
4564 Error_Msg_NE ("\found & declared#", N, T_Name);
4565 Set_Entity (N, Any_Type);
4568 T_Name := Get_Full_View (T_Name);
4570 if In_Open_Scopes (T_Name) then
4571 if Ekind (Base_Type (T_Name)) = E_Task_Type then
4572 Error_Msg_N ("task type cannot be used as type mark " &
4573 "within its own body", N);
4575 Error_Msg_N ("type declaration cannot refer to itself", N);
4578 Set_Etype (N, Any_Type);
4579 Set_Entity (N, Any_Type);
4580 Set_Error_Posted (T_Name);
4584 Set_Entity (N, T_Name);
4585 Set_Etype (N, T_Name);
4589 if Present (Etype (N)) and then Comes_From_Source (N) then
4590 if Is_Fixed_Point_Type (Etype (N)) then
4591 Check_Restriction (No_Fixed_Point, N);
4592 elsif Is_Floating_Point_Type (Etype (N)) then
4593 Check_Restriction (No_Floating_Point, N);
4602 function Get_Full_View (T_Name : Entity_Id) return Entity_Id is
4604 if Ekind (T_Name) = E_Incomplete_Type
4605 and then Present (Full_View (T_Name))
4607 return Full_View (T_Name);
4609 elsif Is_Class_Wide_Type (T_Name)
4610 and then Ekind (Root_Type (T_Name)) = E_Incomplete_Type
4611 and then Present (Full_View (Root_Type (T_Name)))
4613 return Class_Wide_Type (Full_View (Root_Type (T_Name)));
4620 ------------------------------------
4621 -- Has_Implicit_Character_Literal --
4622 ------------------------------------
4624 function Has_Implicit_Character_Literal (N : Node_Id) return Boolean is
4626 Found : Boolean := False;
4627 P : constant Entity_Id := Entity (Prefix (N));
4628 Priv_Id : Entity_Id := Empty;
4631 if Ekind (P) = E_Package
4632 and then not In_Open_Scopes (P)
4634 Priv_Id := First_Private_Entity (P);
4637 if P = Standard_Standard then
4638 Change_Selected_Component_To_Expanded_Name (N);
4639 Rewrite (N, Selector_Name (N));
4641 Set_Etype (Original_Node (N), Standard_Character);
4645 Id := First_Entity (P);
4648 and then Id /= Priv_Id
4650 if Is_Character_Type (Id)
4651 and then (Root_Type (Id) = Standard_Character
4652 or else Root_Type (Id) = Standard_Wide_Character
4653 or else Root_Type (Id) = Standard_Wide_Wide_Character)
4654 and then Id = Base_Type (Id)
4656 -- We replace the node with the literal itself, resolve as a
4657 -- character, and set the type correctly.
4660 Change_Selected_Component_To_Expanded_Name (N);
4661 Rewrite (N, Selector_Name (N));
4664 Set_Etype (Original_Node (N), Id);
4668 -- More than one type derived from Character in given scope.
4669 -- Collect all possible interpretations.
4671 Add_One_Interp (N, Id, Id);
4679 end Has_Implicit_Character_Literal;
4681 ----------------------
4682 -- Has_Private_With --
4683 ----------------------
4685 function Has_Private_With (E : Entity_Id) return Boolean is
4686 Comp_Unit : constant Node_Id := Cunit (Current_Sem_Unit);
4690 Item := First (Context_Items (Comp_Unit));
4691 while Present (Item) loop
4692 if Nkind (Item) = N_With_Clause
4693 and then Private_Present (Item)
4694 and then Entity (Name (Item)) = E
4703 end Has_Private_With;
4705 ---------------------------
4706 -- Has_Implicit_Operator --
4707 ---------------------------
4709 function Has_Implicit_Operator (N : Node_Id) return Boolean is
4710 Op_Id : constant Name_Id := Chars (Selector_Name (N));
4711 P : constant Entity_Id := Entity (Prefix (N));
4713 Priv_Id : Entity_Id := Empty;
4715 procedure Add_Implicit_Operator
4717 Op_Type : Entity_Id := Empty);
4718 -- Add implicit interpretation to node N, using the type for which
4719 -- a predefined operator exists. If the operator yields a boolean
4720 -- type, the Operand_Type is implicitly referenced by the operator,
4721 -- and a reference to it must be generated.
4723 ---------------------------
4724 -- Add_Implicit_Operator --
4725 ---------------------------
4727 procedure Add_Implicit_Operator
4729 Op_Type : Entity_Id := Empty)
4731 Predef_Op : Entity_Id;
4734 Predef_Op := Current_Entity (Selector_Name (N));
4736 while Present (Predef_Op)
4737 and then Scope (Predef_Op) /= Standard_Standard
4739 Predef_Op := Homonym (Predef_Op);
4742 if Nkind (N) = N_Selected_Component then
4743 Change_Selected_Component_To_Expanded_Name (N);
4746 Add_One_Interp (N, Predef_Op, T);
4748 -- For operators with unary and binary interpretations, add both
4750 if Present (Homonym (Predef_Op)) then
4751 Add_One_Interp (N, Homonym (Predef_Op), T);
4754 -- The node is a reference to a predefined operator, and
4755 -- an implicit reference to the type of its operands.
4757 if Present (Op_Type) then
4758 Generate_Operator_Reference (N, Op_Type);
4760 Generate_Operator_Reference (N, T);
4762 end Add_Implicit_Operator;
4764 -- Start of processing for Has_Implicit_Operator
4768 if Ekind (P) = E_Package
4769 and then not In_Open_Scopes (P)
4771 Priv_Id := First_Private_Entity (P);
4774 Id := First_Entity (P);
4778 -- Boolean operators: an implicit declaration exists if the scope
4779 -- contains a declaration for a derived Boolean type, or for an
4780 -- array of Boolean type.
4782 when Name_Op_And | Name_Op_Not | Name_Op_Or | Name_Op_Xor =>
4784 while Id /= Priv_Id loop
4786 if Valid_Boolean_Arg (Id)
4787 and then Id = Base_Type (Id)
4789 Add_Implicit_Operator (Id);
4796 -- Equality: look for any non-limited type (result is Boolean)
4798 when Name_Op_Eq | Name_Op_Ne =>
4800 while Id /= Priv_Id loop
4803 and then not Is_Limited_Type (Id)
4804 and then Id = Base_Type (Id)
4806 Add_Implicit_Operator (Standard_Boolean, Id);
4813 -- Comparison operators: scalar type, or array of scalar
4815 when Name_Op_Lt | Name_Op_Le | Name_Op_Gt | Name_Op_Ge =>
4817 while Id /= Priv_Id loop
4818 if (Is_Scalar_Type (Id)
4819 or else (Is_Array_Type (Id)
4820 and then Is_Scalar_Type (Component_Type (Id))))
4821 and then Id = Base_Type (Id)
4823 Add_Implicit_Operator (Standard_Boolean, Id);
4830 -- Arithmetic operators: any numeric type
4841 while Id /= Priv_Id loop
4842 if Is_Numeric_Type (Id)
4843 and then Id = Base_Type (Id)
4845 Add_Implicit_Operator (Id);
4852 -- Concatenation: any one-dimensional array type
4854 when Name_Op_Concat =>
4856 while Id /= Priv_Id loop
4857 if Is_Array_Type (Id) and then Number_Dimensions (Id) = 1
4858 and then Id = Base_Type (Id)
4860 Add_Implicit_Operator (Id);
4867 -- What is the others condition here? Should we be using a
4868 -- subtype of Name_Id that would restrict to operators ???
4870 when others => null;
4874 -- If we fall through, then we do not have an implicit operator
4878 end Has_Implicit_Operator;
4880 --------------------
4881 -- In_Open_Scopes --
4882 --------------------
4884 function In_Open_Scopes (S : Entity_Id) return Boolean is
4886 -- Since there are several scope stacks maintained by Scope_Stack each
4887 -- delineated by Standard (see comments by definition of Scope_Stack)
4888 -- it is necessary to end the search when Standard is reached.
4890 for J in reverse 0 .. Scope_Stack.Last loop
4891 if Scope_Stack.Table (J).Entity = S then
4895 -- We need Is_Active_Stack_Base to tell us when to stop rather
4896 -- than checking for Standard_Standard because there are cases
4897 -- where Standard_Standard appears in the middle of the active
4898 -- set of scopes. This affects the declaration and overriding
4899 -- of private inherited operations in instantiations of generic
4902 exit when Scope_Stack.Table (J).Is_Active_Stack_Base;
4908 -----------------------------
4909 -- Inherit_Renamed_Profile --
4910 -----------------------------
4912 procedure Inherit_Renamed_Profile (New_S : Entity_Id; Old_S : Entity_Id) is
4919 if Ekind (Old_S) = E_Operator then
4921 New_F := First_Formal (New_S);
4923 while Present (New_F) loop
4924 Set_Etype (New_F, Base_Type (Etype (New_F)));
4925 Next_Formal (New_F);
4928 Set_Etype (New_S, Base_Type (Etype (New_S)));
4931 New_F := First_Formal (New_S);
4932 Old_F := First_Formal (Old_S);
4934 while Present (New_F) loop
4935 New_T := Etype (New_F);
4936 Old_T := Etype (Old_F);
4938 -- If the new type is a renaming of the old one, as is the
4939 -- case for actuals in instances, retain its name, to simplify
4940 -- later disambiguation.
4942 if Nkind (Parent (New_T)) = N_Subtype_Declaration
4943 and then Is_Entity_Name (Subtype_Indication (Parent (New_T)))
4944 and then Entity (Subtype_Indication (Parent (New_T))) = Old_T
4948 Set_Etype (New_F, Old_T);
4951 Next_Formal (New_F);
4952 Next_Formal (Old_F);
4955 if Ekind (Old_S) = E_Function
4956 or else Ekind (Old_S) = E_Enumeration_Literal
4958 Set_Etype (New_S, Etype (Old_S));
4961 end Inherit_Renamed_Profile;
4967 procedure Initialize is
4972 -------------------------
4973 -- Install_Use_Clauses --
4974 -------------------------
4976 procedure Install_Use_Clauses
4978 Force_Installation : Boolean := False)
4980 U : Node_Id := Clause;
4985 while Present (U) loop
4987 -- Case of USE package
4989 if Nkind (U) = N_Use_Package_Clause then
4990 P := First (Names (U));
4992 while Present (P) loop
4995 if Ekind (Id) = E_Package then
4998 Set_Redundant_Use (P, True);
5000 elsif Present (Renamed_Object (Id))
5001 and then In_Use (Renamed_Object (Id))
5003 Set_Redundant_Use (P, True);
5005 elsif Force_Installation or else Applicable_Use (P) then
5006 Use_One_Package (Id, U);
5017 P := First (Subtype_Marks (U));
5019 while Present (P) loop
5020 if not Is_Entity_Name (P)
5021 or else No (Entity (P))
5025 elsif Entity (P) /= Any_Type then
5033 Next_Use_Clause (U);
5035 end Install_Use_Clauses;
5037 -------------------------------------
5038 -- Is_Appropriate_For_Entry_Prefix --
5039 -------------------------------------
5041 function Is_Appropriate_For_Entry_Prefix (T : Entity_Id) return Boolean is
5042 P_Type : Entity_Id := T;
5045 if Is_Access_Type (P_Type) then
5046 P_Type := Designated_Type (P_Type);
5049 return Is_Task_Type (P_Type) or else Is_Protected_Type (P_Type);
5050 end Is_Appropriate_For_Entry_Prefix;
5052 -------------------------------
5053 -- Is_Appropriate_For_Record --
5054 -------------------------------
5056 function Is_Appropriate_For_Record (T : Entity_Id) return Boolean is
5058 function Has_Components (T1 : Entity_Id) return Boolean;
5059 -- Determine if given type has components (i.e. is either a record
5060 -- type or a type that has discriminants).
5062 function Has_Components (T1 : Entity_Id) return Boolean is
5064 return Is_Record_Type (T1)
5065 or else (Is_Private_Type (T1) and then Has_Discriminants (T1))
5066 or else (Is_Task_Type (T1) and then Has_Discriminants (T1));
5069 -- Start of processing for Is_Appropriate_For_Record
5074 and then (Has_Components (T)
5075 or else (Is_Access_Type (T)
5077 Has_Components (Designated_Type (T))));
5078 end Is_Appropriate_For_Record;
5084 procedure New_Scope (S : Entity_Id) is
5088 if Ekind (S) = E_Void then
5091 -- Set scope depth if not a non-concurrent type, and we have not
5092 -- yet set the scope depth. This means that we have the first
5093 -- occurrence of the scope, and this is where the depth is set.
5095 elsif (not Is_Type (S) or else Is_Concurrent_Type (S))
5096 and then not Scope_Depth_Set (S)
5098 if S = Standard_Standard then
5099 Set_Scope_Depth_Value (S, Uint_0);
5101 elsif Is_Child_Unit (S) then
5102 Set_Scope_Depth_Value (S, Uint_1);
5104 elsif not Is_Record_Type (Current_Scope) then
5105 if Ekind (S) = E_Loop then
5106 Set_Scope_Depth_Value (S, Scope_Depth (Current_Scope));
5108 Set_Scope_Depth_Value (S, Scope_Depth (Current_Scope) + 1);
5113 Scope_Stack.Increment_Last;
5116 SST : Scope_Stack_Entry renames Scope_Stack.Table (Scope_Stack.Last);
5120 SST.Save_Scope_Suppress := Scope_Suppress;
5121 SST.Save_Local_Entity_Suppress := Local_Entity_Suppress.Last;
5123 if Scope_Stack.Last > Scope_Stack.First then
5124 SST.Component_Alignment_Default := Scope_Stack.Table
5125 (Scope_Stack.Last - 1).
5126 Component_Alignment_Default;
5129 SST.Last_Subprogram_Name := null;
5130 SST.Is_Transient := False;
5131 SST.Node_To_Be_Wrapped := Empty;
5132 SST.Pending_Freeze_Actions := No_List;
5133 SST.Actions_To_Be_Wrapped_Before := No_List;
5134 SST.Actions_To_Be_Wrapped_After := No_List;
5135 SST.First_Use_Clause := Empty;
5136 SST.Is_Active_Stack_Base := False;
5139 if Debug_Flag_W then
5140 Write_Str ("--> new scope: ");
5141 Write_Name (Chars (Current_Scope));
5142 Write_Str (", Id=");
5143 Write_Int (Int (Current_Scope));
5144 Write_Str (", Depth=");
5145 Write_Int (Int (Scope_Stack.Last));
5149 -- Copy from Scope (S) the categorization flags to S, this is not
5150 -- done in case Scope (S) is Standard_Standard since propagation
5151 -- is from library unit entity inwards.
5153 if S /= Standard_Standard
5154 and then Scope (S) /= Standard_Standard
5155 and then not Is_Child_Unit (S)
5159 if Nkind (E) not in N_Entity then
5163 -- We only propagate inwards for library level entities,
5164 -- inner level subprograms do not inherit the categorization.
5166 if Is_Library_Level_Entity (S) then
5167 Set_Is_Preelaborated (S, Is_Preelaborated (E));
5168 Set_Is_Shared_Passive (S, Is_Shared_Passive (E));
5169 Set_Categorization_From_Scope (E => S, Scop => E);
5178 procedure Pop_Scope is
5179 SST : Scope_Stack_Entry renames Scope_Stack.Table (Scope_Stack.Last);
5182 if Debug_Flag_E then
5186 Scope_Suppress := SST.Save_Scope_Suppress;
5187 Local_Entity_Suppress.Set_Last (SST.Save_Local_Entity_Suppress);
5189 if Debug_Flag_W then
5190 Write_Str ("--> exiting scope: ");
5191 Write_Name (Chars (Current_Scope));
5192 Write_Str (", Depth=");
5193 Write_Int (Int (Scope_Stack.Last));
5197 End_Use_Clauses (SST.First_Use_Clause);
5199 -- If the actions to be wrapped are still there they will get lost
5200 -- causing incomplete code to be generated. It is better to abort in
5201 -- this case (and we do the abort even with assertions off since the
5202 -- penalty is incorrect code generation)
5204 if SST.Actions_To_Be_Wrapped_Before /= No_List
5206 SST.Actions_To_Be_Wrapped_After /= No_List
5211 -- Free last subprogram name if allocated, and pop scope
5213 Free (SST.Last_Subprogram_Name);
5214 Scope_Stack.Decrement_Last;
5217 ---------------------
5218 -- Premature_Usage --
5219 ---------------------
5221 procedure Premature_Usage (N : Node_Id) is
5222 Kind : constant Node_Kind := Nkind (Parent (Entity (N)));
5223 E : Entity_Id := Entity (N);
5226 -- Within an instance, the analysis of the actual for a formal object
5227 -- does not see the name of the object itself. This is significant
5228 -- only if the object is an aggregate, where its analysis does not do
5229 -- any name resolution on component associations. (see 4717-008). In
5230 -- such a case, look for the visible homonym on the chain.
5233 and then Present (Homonym (E))
5238 and then not In_Open_Scopes (Scope (E))
5245 Set_Etype (N, Etype (E));
5250 if Kind = N_Component_Declaration then
5252 ("component&! cannot be used before end of record declaration", N);
5254 elsif Kind = N_Parameter_Specification then
5256 ("formal parameter&! cannot be used before end of specification",
5259 elsif Kind = N_Discriminant_Specification then
5261 ("discriminant&! cannot be used before end of discriminant part",
5264 elsif Kind = N_Procedure_Specification
5265 or else Kind = N_Function_Specification
5268 ("subprogram&! cannot be used before end of its declaration",
5272 ("object& cannot be used before end of its declaration!", N);
5274 end Premature_Usage;
5276 ------------------------
5277 -- Present_System_Aux --
5278 ------------------------
5280 function Present_System_Aux (N : Node_Id := Empty) return Boolean is
5283 Unum : Unit_Number_Type;
5288 function Find_System (C_Unit : Node_Id) return Entity_Id;
5289 -- Scan context clause of compilation unit to find a with_clause
5296 function Find_System (C_Unit : Node_Id) return Entity_Id is
5297 With_Clause : Node_Id;
5300 With_Clause := First (Context_Items (C_Unit));
5302 while Present (With_Clause) loop
5303 if (Nkind (With_Clause) = N_With_Clause
5304 and then Chars (Name (With_Clause)) = Name_System)
5305 and then Comes_From_Source (With_Clause)
5316 -- Start of processing for Present_System_Aux
5319 -- The child unit may have been loaded and analyzed already
5321 if Present (System_Aux_Id) then
5324 -- If no previous pragma for System.Aux, nothing to load
5326 elsif No (System_Extend_Unit) then
5329 -- Use the unit name given in the pragma to retrieve the unit.
5330 -- Verify that System itself appears in the context clause of the
5331 -- current compilation. If System is not present, an error will
5332 -- have been reported already.
5335 With_Sys := Find_System (Cunit (Current_Sem_Unit));
5337 The_Unit := Unit (Cunit (Current_Sem_Unit));
5340 and then (Nkind (The_Unit) = N_Package_Body
5341 or else (Nkind (The_Unit) = N_Subprogram_Body
5342 and then not Acts_As_Spec (Cunit (Current_Sem_Unit))))
5344 With_Sys := Find_System (Library_Unit (Cunit (Current_Sem_Unit)));
5348 and then Present (N)
5350 -- If we are compiling a subunit, we need to examine its
5351 -- context as well (Current_Sem_Unit is the parent unit);
5353 The_Unit := Parent (N);
5355 while Nkind (The_Unit) /= N_Compilation_Unit loop
5356 The_Unit := Parent (The_Unit);
5359 if Nkind (Unit (The_Unit)) = N_Subunit then
5360 With_Sys := Find_System (The_Unit);
5364 if No (With_Sys) then
5368 Loc := Sloc (With_Sys);
5369 Get_Name_String (Chars (Expression (System_Extend_Unit)));
5370 Name_Buffer (8 .. Name_Len + 7) := Name_Buffer (1 .. Name_Len);
5371 Name_Buffer (1 .. 7) := "system.";
5372 Name_Buffer (Name_Len + 8) := '%';
5373 Name_Buffer (Name_Len + 9) := 's';
5374 Name_Len := Name_Len + 9;
5375 Aux_Name := Name_Find;
5379 (Load_Name => Aux_Name,
5382 Error_Node => With_Sys);
5384 if Unum /= No_Unit then
5385 Semantics (Cunit (Unum));
5387 Defining_Entity (Specification (Unit (Cunit (Unum))));
5389 Withn := Make_With_Clause (Loc,
5391 Make_Expanded_Name (Loc,
5392 Chars => Chars (System_Aux_Id),
5394 New_Reference_To (Scope (System_Aux_Id), Loc),
5396 New_Reference_To (System_Aux_Id, Loc)));
5398 Set_Entity (Name (Withn), System_Aux_Id);
5400 Set_Library_Unit (Withn, Cunit (Unum));
5401 Set_Corresponding_Spec (Withn, System_Aux_Id);
5402 Set_First_Name (Withn, True);
5403 Set_Implicit_With (Withn, True);
5405 Insert_After (With_Sys, Withn);
5406 Mark_Rewrite_Insertion (Withn);
5407 Set_Context_Installed (Withn);
5411 -- Here if unit load failed
5414 Error_Msg_Name_1 := Name_System;
5415 Error_Msg_Name_2 := Chars (Expression (System_Extend_Unit));
5417 ("extension package `%.%` does not exist",
5418 Opt.System_Extend_Unit);
5422 end Present_System_Aux;
5424 -------------------------
5425 -- Restore_Scope_Stack --
5426 -------------------------
5428 procedure Restore_Scope_Stack (Handle_Use : Boolean := True) is
5431 Comp_Unit : Node_Id;
5432 In_Child : Boolean := False;
5433 Full_Vis : Boolean := True;
5434 SS_Last : constant Int := Scope_Stack.Last;
5437 -- Restore visibility of previous scope stack, if any
5439 for J in reverse 0 .. Scope_Stack.Last loop
5440 exit when Scope_Stack.Table (J).Entity = Standard_Standard
5441 or else No (Scope_Stack.Table (J).Entity);
5443 S := Scope_Stack.Table (J).Entity;
5445 if not Is_Hidden_Open_Scope (S) then
5447 -- If the parent scope is hidden, its entities are hidden as
5448 -- well, unless the entity is the instantiation currently
5451 if not Is_Hidden_Open_Scope (Scope (S))
5452 or else not Analyzed (Parent (S))
5453 or else Scope (S) = Standard_Standard
5455 Set_Is_Immediately_Visible (S, True);
5458 E := First_Entity (S);
5460 while Present (E) loop
5461 if Is_Child_Unit (E) then
5462 Set_Is_Immediately_Visible (E,
5463 Is_Visible_Child_Unit (E) or else In_Open_Scopes (E));
5465 Set_Is_Immediately_Visible (E, True);
5470 if not Full_Vis then
5471 exit when E = First_Private_Entity (S);
5475 -- The visibility of child units (siblings of current compilation)
5476 -- must be restored in any case. Their declarations may appear
5477 -- after the private part of the parent.
5480 and then Present (E)
5482 while Present (E) loop
5483 if Is_Child_Unit (E) then
5484 Set_Is_Immediately_Visible (E,
5485 Is_Visible_Child_Unit (E) or else In_Open_Scopes (E));
5493 if Is_Child_Unit (S)
5494 and not In_Child -- check only for current unit.
5498 -- restore visibility of parents according to whether the child
5499 -- is private and whether we are in its visible part.
5501 Comp_Unit := Parent (Unit_Declaration_Node (S));
5503 if Nkind (Comp_Unit) = N_Compilation_Unit
5504 and then Private_Present (Comp_Unit)
5508 elsif (Ekind (S) = E_Package
5509 or else Ekind (S) = E_Generic_Package)
5510 and then (In_Private_Part (S)
5511 or else In_Package_Body (S))
5515 elsif (Ekind (S) = E_Procedure
5516 or else Ekind (S) = E_Function)
5517 and then Has_Completion (S)
5528 if SS_Last >= Scope_Stack.First
5529 and then Scope_Stack.Table (SS_Last).Entity /= Standard_Standard
5532 Install_Use_Clauses (Scope_Stack.Table (SS_Last).First_Use_Clause);
5534 end Restore_Scope_Stack;
5536 ----------------------
5537 -- Save_Scope_Stack --
5538 ----------------------
5540 procedure Save_Scope_Stack (Handle_Use : Boolean := True) is
5543 SS_Last : constant Int := Scope_Stack.Last;
5546 if SS_Last >= Scope_Stack.First
5547 and then Scope_Stack.Table (SS_Last).Entity /= Standard_Standard
5550 End_Use_Clauses (Scope_Stack.Table (SS_Last).First_Use_Clause);
5553 -- If the call is from within a compilation unit, as when
5554 -- called from Rtsfind, make current entries in scope stack
5555 -- invisible while we analyze the new unit.
5557 for J in reverse 0 .. SS_Last loop
5558 exit when Scope_Stack.Table (J).Entity = Standard_Standard
5559 or else No (Scope_Stack.Table (J).Entity);
5561 S := Scope_Stack.Table (J).Entity;
5562 Set_Is_Immediately_Visible (S, False);
5563 E := First_Entity (S);
5565 while Present (E) loop
5566 Set_Is_Immediately_Visible (E, False);
5572 end Save_Scope_Stack;
5578 procedure Set_Use (L : List_Id) is
5580 Pack_Name : Node_Id;
5588 while Present (Decl) loop
5589 if Nkind (Decl) = N_Use_Package_Clause then
5590 Chain_Use_Clause (Decl);
5591 Pack_Name := First (Names (Decl));
5593 while Present (Pack_Name) loop
5594 Pack := Entity (Pack_Name);
5596 if Ekind (Pack) = E_Package
5597 and then Applicable_Use (Pack_Name)
5599 Use_One_Package (Pack, Decl);
5605 elsif Nkind (Decl) = N_Use_Type_Clause then
5606 Chain_Use_Clause (Decl);
5607 Id := First (Subtype_Marks (Decl));
5609 while Present (Id) loop
5610 if Entity (Id) /= Any_Type then
5623 ---------------------
5624 -- Use_One_Package --
5625 ---------------------
5627 procedure Use_One_Package (P : Entity_Id; N : Node_Id) is
5630 Current_Instance : Entity_Id := Empty;
5632 Private_With_OK : Boolean := False;
5635 if Ekind (P) /= E_Package then
5641 -- Ada 2005 (AI-50217): Check restriction
5643 if From_With_Type (P) then
5644 Error_Msg_N ("limited withed package cannot appear in use clause", N);
5647 -- Find enclosing instance, if any
5650 Current_Instance := Current_Scope;
5652 while not Is_Generic_Instance (Current_Instance) loop
5653 Current_Instance := Scope (Current_Instance);
5656 if No (Hidden_By_Use_Clause (N)) then
5657 Set_Hidden_By_Use_Clause (N, New_Elmt_List);
5661 -- If unit is a package renaming, indicate that the renamed
5662 -- package is also in use (the flags on both entities must
5663 -- remain consistent, and a subsequent use of either of them
5664 -- should be recognized as redundant).
5666 if Present (Renamed_Object (P)) then
5667 Set_In_Use (Renamed_Object (P));
5668 Real_P := Renamed_Object (P);
5673 -- Ada 2005 (AI-262): Check the use_clause of a private withed package
5674 -- found in the private part of a package specification
5676 if In_Private_Part (Current_Scope)
5677 and then Has_Private_With (P)
5678 and then Is_Child_Unit (Current_Scope)
5679 and then Is_Child_Unit (P)
5680 and then Is_Ancestor_Package (Scope (Current_Scope), P)
5682 Private_With_OK := True;
5685 -- Loop through entities in one package making them potentially
5688 Id := First_Entity (P);
5690 and then (Id /= First_Private_Entity (P)
5691 or else Private_With_OK) -- Ada 2005 (AI-262)
5693 Prev := Current_Entity (Id);
5695 while Present (Prev) loop
5696 if Is_Immediately_Visible (Prev)
5697 and then (not Is_Overloadable (Prev)
5698 or else not Is_Overloadable (Id)
5699 or else (Type_Conformant (Id, Prev)))
5701 if No (Current_Instance) then
5703 -- Potentially use-visible entity remains hidden
5705 goto Next_Usable_Entity;
5707 -- A use clause within an instance hides outer global
5708 -- entities, which are not used to resolve local entities
5709 -- in the instance. Note that the predefined entities in
5710 -- Standard could not have been hidden in the generic by
5711 -- a use clause, and therefore remain visible. Other
5712 -- compilation units whose entities appear in Standard must
5713 -- be hidden in an instance.
5715 -- To determine whether an entity is external to the instance
5716 -- we compare the scope depth of its scope with that of the
5717 -- current instance. However, a generic actual of a subprogram
5718 -- instance is declared in the wrapper package but will not be
5719 -- hidden by a use-visible entity.
5721 -- If Id is called Standard, the predefined package with the
5722 -- same name is in the homonym chain. It has to be ignored
5723 -- because it has no defined scope (being the only entity in
5724 -- the system with this mandated behavior).
5726 elsif not Is_Hidden (Id)
5727 and then Present (Scope (Prev))
5728 and then not Is_Wrapper_Package (Scope (Prev))
5729 and then Scope_Depth (Scope (Prev)) <
5730 Scope_Depth (Current_Instance)
5731 and then (Scope (Prev) /= Standard_Standard
5732 or else Sloc (Prev) > Standard_Location)
5734 Set_Is_Potentially_Use_Visible (Id);
5735 Set_Is_Immediately_Visible (Prev, False);
5736 Append_Elmt (Prev, Hidden_By_Use_Clause (N));
5739 -- A user-defined operator is not use-visible if the
5740 -- predefined operator for the type is immediately visible,
5741 -- which is the case if the type of the operand is in an open
5742 -- scope. This does not apply to user-defined operators that
5743 -- have operands of different types, because the predefined
5744 -- mixed mode operations (multiplication and division) apply to
5745 -- universal types and do not hide anything.
5747 elsif Ekind (Prev) = E_Operator
5748 and then Operator_Matches_Spec (Prev, Id)
5749 and then In_Open_Scopes
5750 (Scope (Base_Type (Etype (First_Formal (Id)))))
5751 and then (No (Next_Formal (First_Formal (Id)))
5752 or else Etype (First_Formal (Id))
5753 = Etype (Next_Formal (First_Formal (Id)))
5754 or else Chars (Prev) = Name_Op_Expon)
5756 goto Next_Usable_Entity;
5759 Prev := Homonym (Prev);
5762 -- On exit, we know entity is not hidden, unless it is private
5764 if not Is_Hidden (Id)
5765 and then ((not Is_Child_Unit (Id))
5766 or else Is_Visible_Child_Unit (Id))
5768 Set_Is_Potentially_Use_Visible (Id);
5770 if Is_Private_Type (Id)
5771 and then Present (Full_View (Id))
5773 Set_Is_Potentially_Use_Visible (Full_View (Id));
5777 <<Next_Usable_Entity>>
5781 -- Child units are also made use-visible by a use clause, but they
5782 -- may appear after all visible declarations in the parent entity list.
5784 while Present (Id) loop
5786 if Is_Child_Unit (Id)
5787 and then Is_Visible_Child_Unit (Id)
5789 Set_Is_Potentially_Use_Visible (Id);
5795 if Chars (Real_P) = Name_System
5796 and then Scope (Real_P) = Standard_Standard
5797 and then Present_System_Aux (N)
5799 Use_One_Package (System_Aux_Id, N);
5802 end Use_One_Package;
5808 procedure Use_One_Type (Id : Node_Id) is
5814 -- It is the type determined by the subtype mark (8.4(8)) whose
5815 -- operations become potentially use-visible.
5817 T := Base_Type (Entity (Id));
5822 or else Is_Potentially_Use_Visible (T)
5823 or else In_Use (Scope (T)));
5825 if In_Open_Scopes (Scope (T)) then
5828 -- If the subtype mark designates a subtype in a different package,
5829 -- we have to check that the parent type is visible, otherwise the
5830 -- use type clause is a noop. Not clear how to do that???
5832 elsif not Redundant_Use (Id) then
5834 Op_List := Collect_Primitive_Operations (T);
5835 Elmt := First_Elmt (Op_List);
5837 while Present (Elmt) loop
5839 if (Nkind (Node (Elmt)) = N_Defining_Operator_Symbol
5840 or else Chars (Node (Elmt)) in Any_Operator_Name)
5841 and then not Is_Hidden (Node (Elmt))
5843 Set_Is_Potentially_Use_Visible (Node (Elmt));
5855 procedure Write_Info is
5856 Id : Entity_Id := First_Entity (Current_Scope);
5859 -- No point in dumping standard entities
5861 if Current_Scope = Standard_Standard then
5865 Write_Str ("========================================================");
5867 Write_Str (" Defined Entities in ");
5868 Write_Name (Chars (Current_Scope));
5870 Write_Str ("========================================================");
5874 Write_Str ("-- none --");
5878 while Present (Id) loop
5879 Write_Entity_Info (Id, " ");
5884 if Scope (Current_Scope) = Standard_Standard then
5886 -- Print information on the current unit itself
5888 Write_Entity_Info (Current_Scope, " ");
5898 procedure Write_Scopes is
5902 for J in reverse 1 .. Scope_Stack.Last loop
5903 S := Scope_Stack.Table (J).Entity;
5904 Write_Int (Int (S));
5905 Write_Str (" === ");
5906 Write_Name (Chars (S));
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