1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2007, Free Software Foundation, Inc. --
11 -- GNAT is free software; you can redistribute it and/or modify it under --
12 -- terms of the GNU General Public License as published by the Free Soft- --
13 -- ware Foundation; either version 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, 51 Franklin Street, Fifth Floor, --
20 -- Boston, MA 02110-1301, 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;
36 with Impunit; use Impunit;
38 with Lib.Load; use Lib.Load;
39 with Lib.Xref; use Lib.Xref;
40 with Namet; use Namet;
41 with Nlists; use Nlists;
42 with Nmake; use Nmake;
44 with Output; use Output;
45 with Restrict; use Restrict;
46 with Rident; use Rident;
47 with Rtsfind; use Rtsfind;
49 with Sem_Cat; use Sem_Cat;
50 with Sem_Ch3; use Sem_Ch3;
51 with Sem_Ch4; use Sem_Ch4;
52 with Sem_Ch6; use Sem_Ch6;
53 with Sem_Ch12; use Sem_Ch12;
54 with Sem_Disp; use Sem_Disp;
55 with Sem_Dist; use Sem_Dist;
56 with Sem_Res; use Sem_Res;
57 with Sem_Util; use Sem_Util;
58 with Sem_Type; use Sem_Type;
59 with Stand; use Stand;
60 with Sinfo; use Sinfo;
61 with Sinfo.CN; use Sinfo.CN;
62 with Snames; use Snames;
63 with Style; use Style;
65 with Tbuild; use Tbuild;
66 with Uintp; use Uintp;
68 with GNAT.Spelling_Checker; use GNAT.Spelling_Checker;
70 package body Sem_Ch8 is
72 ------------------------------------
73 -- Visibility and Name Resolution --
74 ------------------------------------
76 -- This package handles name resolution and the collection of
77 -- interpretations for overloaded names, prior to overload resolution.
79 -- Name resolution is the process that establishes a mapping between source
80 -- identifiers and the entities they denote at each point in the program.
81 -- Each entity is represented by a defining occurrence. Each identifier
82 -- that denotes an entity points to the corresponding defining occurrence.
83 -- This is the entity of the applied occurrence. Each occurrence holds
84 -- an index into the names table, where source identifiers are stored.
86 -- Each entry in the names table for an identifier or designator uses the
87 -- Info pointer to hold a link to the currently visible entity that has
88 -- this name (see subprograms Get_Name_Entity_Id and Set_Name_Entity_Id
89 -- in package Sem_Util). The visibility is initialized at the beginning of
90 -- semantic processing to make entities in package Standard immediately
91 -- visible. The visibility table is used in a more subtle way when
92 -- compiling subunits (see below).
94 -- Entities that have the same name (i.e. homonyms) are chained. In the
95 -- case of overloaded entities, this chain holds all the possible meanings
96 -- of a given identifier. The process of overload resolution uses type
97 -- information to select from this chain the unique meaning of a given
100 -- Entities are also chained in their scope, through the Next_Entity link.
101 -- As a consequence, the name space is organized as a sparse matrix, where
102 -- each row corresponds to a scope, and each column to a source identifier.
103 -- Open scopes, that is to say scopes currently being compiled, have their
104 -- corresponding rows of entities in order, innermost scope first.
106 -- The scopes of packages that are mentioned in context clauses appear in
107 -- no particular order, interspersed among open scopes. This is because
108 -- in the course of analyzing the context of a compilation, a package
109 -- declaration is first an open scope, and subsequently an element of the
110 -- context. If subunits or child units are present, a parent unit may
111 -- appear under various guises at various times in the compilation.
113 -- When the compilation of the innermost scope is complete, the entities
114 -- defined therein are no longer visible. If the scope is not a package
115 -- declaration, these entities are never visible subsequently, and can be
116 -- removed from visibility chains. If the scope is a package declaration,
117 -- its visible declarations may still be accessible. Therefore the entities
118 -- defined in such a scope are left on the visibility chains, and only
119 -- their visibility (immediately visibility or potential use-visibility)
122 -- The ordering of homonyms on their chain does not necessarily follow
123 -- the order of their corresponding scopes on the scope stack. For
124 -- example, if package P and the enclosing scope both contain entities
125 -- named E, then when compiling the package body the chain for E will
126 -- hold the global entity first, and the local one (corresponding to
127 -- the current inner scope) next. As a result, name resolution routines
128 -- do not assume any relative ordering of the homonym chains, either
129 -- for scope nesting or to order of appearance of context clauses.
131 -- When compiling a child unit, entities in the parent scope are always
132 -- immediately visible. When compiling the body of a child unit, private
133 -- entities in the parent must also be made immediately visible. There
134 -- are separate routines to make the visible and private declarations
135 -- visible at various times (see package Sem_Ch7).
137 -- +--------+ +-----+
138 -- | In use |-------->| EU1 |-------------------------->
139 -- +--------+ +-----+
141 -- +--------+ +-----+ +-----+
142 -- | Stand. |---------------->| ES1 |--------------->| ES2 |--->
143 -- +--------+ +-----+ +-----+
145 -- +---------+ | +-----+
146 -- | with'ed |------------------------------>| EW2 |--->
147 -- +---------+ | +-----+
149 -- +--------+ +-----+ +-----+
150 -- | Scope2 |---------------->| E12 |--------------->| E22 |--->
151 -- +--------+ +-----+ +-----+
153 -- +--------+ +-----+ +-----+
154 -- | Scope1 |---------------->| E11 |--------------->| E12 |--->
155 -- +--------+ +-----+ +-----+
159 -- | | with'ed |----------------------------------------->
163 -- (innermost first) | |
164 -- +----------------------------+
165 -- Names table => | Id1 | | | | Id2 |
166 -- +----------------------------+
168 -- Name resolution must deal with several syntactic forms: simple names,
169 -- qualified names, indexed names, and various forms of calls.
171 -- Each identifier points to an entry in the names table. The resolution
172 -- of a simple name consists in traversing the homonym chain, starting
173 -- from the names table. If an entry is immediately visible, it is the one
174 -- designated by the identifier. If only potentially use-visible entities
175 -- are on the chain, we must verify that they do not hide each other. If
176 -- the entity we find is overloadable, we collect all other overloadable
177 -- entities on the chain as long as they are not hidden.
179 -- To resolve expanded names, we must find the entity at the intersection
180 -- of the entity chain for the scope (the prefix) and the homonym chain
181 -- for the selector. In general, homonym chains will be much shorter than
182 -- entity chains, so it is preferable to start from the names table as
183 -- well. If the entity found is overloadable, we must collect all other
184 -- interpretations that are defined in the scope denoted by the prefix.
186 -- For records, protected types, and tasks, their local entities are
187 -- removed from visibility chains on exit from the corresponding scope.
188 -- From the outside, these entities are always accessed by selected
189 -- notation, and the entity chain for the record type, protected type,
190 -- etc. is traversed sequentially in order to find the designated entity.
192 -- The discriminants of a type and the operations of a protected type or
193 -- task are unchained on exit from the first view of the type, (such as
194 -- a private or incomplete type declaration, or a protected type speci-
195 -- fication) and re-chained when compiling the second view.
197 -- In the case of operators, we do not make operators on derived types
198 -- explicit. As a result, the notation P."+" may denote either a user-
199 -- defined function with name "+", or else an implicit declaration of the
200 -- operator "+" in package P. The resolution of expanded names always
201 -- tries to resolve an operator name as such an implicitly defined entity,
202 -- in addition to looking for explicit declarations.
204 -- All forms of names that denote entities (simple names, expanded names,
205 -- character literals in some cases) have a Entity attribute, which
206 -- identifies the entity denoted by the name.
208 ---------------------
209 -- The Scope Stack --
210 ---------------------
212 -- The Scope stack keeps track of the scopes currently been compiled.
213 -- Every entity that contains declarations (including records) is placed
214 -- on the scope stack while it is being processed, and removed at the end.
215 -- Whenever a non-package scope is exited, the entities defined therein
216 -- are removed from the visibility table, so that entities in outer scopes
217 -- become visible (see previous description). On entry to Sem, the scope
218 -- stack only contains the package Standard. As usual, subunits complicate
219 -- this picture ever so slightly.
221 -- The Rtsfind mechanism can force a call to Semantics while another
222 -- compilation is in progress. The unit retrieved by Rtsfind must be
223 -- compiled in its own context, and has no access to the visibility of
224 -- the unit currently being compiled. The procedures Save_Scope_Stack and
225 -- Restore_Scope_Stack make entities in current open scopes invisible
226 -- before compiling the retrieved unit, and restore the compilation
227 -- environment afterwards.
229 ------------------------
230 -- Compiling subunits --
231 ------------------------
233 -- Subunits must be compiled in the environment of the corresponding stub,
234 -- that is to say with the same visibility into the parent (and its
235 -- context) that is available at the point of the stub declaration, but
236 -- with the additional visibility provided by the context clause of the
237 -- subunit itself. As a result, compilation of a subunit forces compilation
238 -- of the parent (see description in lib-). At the point of the stub
239 -- declaration, Analyze is called recursively to compile the proper body of
240 -- the subunit, but without reinitializing the names table, nor the scope
241 -- stack (i.e. standard is not pushed on the stack). In this fashion the
242 -- context of the subunit is added to the context of the parent, and the
243 -- subunit is compiled in the correct environment. Note that in the course
244 -- of processing the context of a subunit, Standard will appear twice on
245 -- the scope stack: once for the parent of the subunit, and once for the
246 -- unit in the context clause being compiled. However, the two sets of
247 -- entities are not linked by homonym chains, so that the compilation of
248 -- any context unit happens in a fresh visibility environment.
250 -------------------------------
251 -- Processing of USE Clauses --
252 -------------------------------
254 -- Every defining occurrence has a flag indicating if it is potentially use
255 -- visible. Resolution of simple names examines this flag. The processing
256 -- of use clauses consists in setting this flag on all visible entities
257 -- defined in the corresponding package. On exit from the scope of the use
258 -- clause, the corresponding flag must be reset. However, a package may
259 -- appear in several nested use clauses (pathological but legal, alas!)
260 -- which forces us to use a slightly more involved scheme:
262 -- a) The defining occurrence for a package holds a flag -In_Use- to
263 -- indicate that it is currently in the scope of a use clause. If a
264 -- redundant use clause is encountered, then the corresponding occurrence
265 -- of the package name is flagged -Redundant_Use-.
267 -- b) On exit from a scope, the use clauses in its declarative part are
268 -- scanned. The visibility flag is reset in all entities declared in
269 -- package named in a use clause, as long as the package is not flagged
270 -- as being in a redundant use clause (in which case the outer use
271 -- clause is still in effect, and the direct visibility of its entities
272 -- must be retained).
274 -- Note that entities are not removed from their homonym chains on exit
275 -- from the package specification. A subsequent use clause does not need
276 -- to rechain the visible entities, but only to establish their direct
279 -----------------------------------
280 -- Handling private declarations --
281 -----------------------------------
283 -- The principle that each entity has a single defining occurrence clashes
284 -- with the presence of two separate definitions for private types: the
285 -- first is the private type declaration, and second is the full type
286 -- declaration. It is important that all references to the type point to
287 -- the same defining occurrence, namely the first one. To enforce the two
288 -- separate views of the entity, the corresponding information is swapped
289 -- between the two declarations. Outside of the package, the defining
290 -- occurrence only contains the private declaration information, while in
291 -- the private part and the body of the package the defining occurrence
292 -- contains the full declaration. To simplify the swap, the defining
293 -- occurrence that currently holds the private declaration points to the
294 -- full declaration. During semantic processing the defining occurrence
295 -- also points to a list of private dependents, that is to say access types
296 -- or composite types whose designated types or component types are
297 -- subtypes or derived types of the private type in question. After the
298 -- full declaration has been seen, the private dependents are updated to
299 -- indicate that they have full definitions.
301 ------------------------------------
302 -- Handling of Undefined Messages --
303 ------------------------------------
305 -- In normal mode, only the first use of an undefined identifier generates
306 -- a message. The table Urefs is used to record error messages that have
307 -- been issued so that second and subsequent ones do not generate further
308 -- messages. However, the second reference causes text to be added to the
309 -- original undefined message noting "(more references follow)". The
310 -- full error list option (-gnatf) forces messages to be generated for
311 -- every reference and disconnects the use of this table.
313 type Uref_Entry is record
315 -- Node for identifier for which original message was posted. The
316 -- Chars field of this identifier is used to detect later references
317 -- to the same identifier.
320 -- Records error message Id of original undefined message. Reset to
321 -- No_Error_Msg after the second occurrence, where it is used to add
322 -- text to the original message as described above.
325 -- Set if the message is not visible rather than undefined
328 -- Records location of error message. Used to make sure that we do
329 -- not consider a, b : undefined as two separate instances, which
330 -- would otherwise happen, since the parser converts this sequence
331 -- to a : undefined; b : undefined.
335 package Urefs is new Table.Table (
336 Table_Component_Type => Uref_Entry,
337 Table_Index_Type => Nat,
338 Table_Low_Bound => 1,
340 Table_Increment => 100,
341 Table_Name => "Urefs");
343 Candidate_Renaming : Entity_Id;
344 -- Holds a candidate interpretation that appears in a subprogram renaming
345 -- declaration and does not match the given specification, but matches at
346 -- least on the first formal. Allows better error message when given
347 -- specification omits defaulted parameters, a common error.
349 -----------------------
350 -- Local Subprograms --
351 -----------------------
353 procedure Analyze_Generic_Renaming
356 -- Common processing for all three kinds of generic renaming declarations.
357 -- Enter new name and indicate that it renames the generic unit.
359 procedure Analyze_Renamed_Character
363 -- Renamed entity is given by a character literal, which must belong
364 -- to the return type of the new entity. Is_Body indicates whether the
365 -- declaration is a renaming_as_body. If the original declaration has
366 -- already been frozen (because of an intervening body, e.g.) the body of
367 -- the function must be built now. The same applies to the following
368 -- various renaming procedures.
370 procedure Analyze_Renamed_Dereference
374 -- Renamed entity is given by an explicit dereference. Prefix must be a
375 -- conformant access_to_subprogram type.
377 procedure Analyze_Renamed_Entry
381 -- If the renamed entity in a subprogram renaming is an entry or protected
382 -- subprogram, build a body for the new entity whose only statement is a
383 -- call to the renamed entity.
385 procedure Analyze_Renamed_Family_Member
389 -- Used when the renamed entity is an indexed component. The prefix must
390 -- denote an entry family.
392 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 in
428 -- the proper scope table entry. This is usually the current scope, but it
429 -- will be an inner scope when installing the use clauses of the private
430 -- declarations of a parent unit prior to compiling the private part of a
431 -- child unit. This chain is traversed when installing/removing use clauses
432 -- when compiling a subunit or instantiating a generic body on the fly,
433 -- when it is necessary to save and restore full environments.
435 function Has_Implicit_Character_Literal (N : Node_Id) return Boolean;
436 -- Find a type derived from Character or Wide_Character in the prefix of N.
437 -- Used to resolved qualified names whose selector is a character literal.
439 function Has_Private_With (E : Entity_Id) return Boolean;
440 -- Ada 2005 (AI-262): Determines if the current compilation unit has a
441 -- private with on E.
443 procedure Find_Expanded_Name (N : Node_Id);
444 -- Selected component is known to be expanded name. Verify legality
445 -- of selector given the scope denoted by prefix.
447 function Find_Renamed_Entity
451 Is_Actual : Boolean := False) return Entity_Id;
452 -- Find the renamed entity that corresponds to the given parameter profile
453 -- in a subprogram renaming declaration. The renamed entity may be an
454 -- operator, a subprogram, an entry, or a protected operation. Is_Actual
455 -- indicates that the renaming is the one generated for an actual subpro-
456 -- gram in an instance, for which special visibility checks apply.
458 function Has_Implicit_Operator (N : Node_Id) return Boolean;
459 -- N is an expanded name whose selector is an operator name (eg P."+").
460 -- declarative part contains an implicit declaration of an operator if it
461 -- has a declaration of a type to which one of the predefined operators
462 -- apply. The existence of this routine is an implementation artifact. A
463 -- more straightforward but more space-consuming choice would be to make
464 -- all inherited operators explicit in the symbol table.
466 procedure Inherit_Renamed_Profile (New_S : Entity_Id; Old_S : Entity_Id);
467 -- A subprogram defined by a renaming declaration inherits the parameter
468 -- profile of the renamed entity. The subtypes given in the subprogram
469 -- specification are discarded and replaced with those of the renamed
470 -- subprogram, which are then used to recheck the default values.
472 function Is_Appropriate_For_Record (T : Entity_Id) return Boolean;
473 -- Prefix is appropriate for record if it is of a record type, or an access
476 function Is_Appropriate_For_Entry_Prefix (T : Entity_Id) return Boolean;
477 -- True if it is of a task type, a protected type, or else an access to one
480 procedure Note_Redundant_Use (Clause : Node_Id);
481 -- Mark the name in a use clause as redundant if the corresponding entity
482 -- is already use-visible. Emit a warning if the use clause comes from
483 -- source and the proper warnings are enabled.
485 procedure Premature_Usage (N : Node_Id);
486 -- Diagnose usage of an entity before it is visible
488 procedure Use_One_Package (P : Entity_Id; N : Node_Id);
489 -- Make visible entities declared in package P potentially use-visible
490 -- in the current context. Also used in the analysis of subunits, when
491 -- re-installing use clauses of parent units. N is the use_clause that
492 -- names P (and possibly other packages).
494 procedure Use_One_Type (Id : Node_Id);
495 -- Id is the subtype mark from a use type clause. This procedure makes
496 -- the primitive operators of the type potentially use-visible.
498 procedure Write_Info;
499 -- Write debugging information on entities declared in current scope
501 procedure Write_Scopes;
502 pragma Warnings (Off, Write_Scopes);
503 -- Debugging information: dump all entities on scope stack
505 --------------------------------
506 -- Analyze_Exception_Renaming --
507 --------------------------------
509 -- The language only allows a single identifier, but the tree holds an
510 -- identifier list. The parser has already issued an error message if
511 -- there is more than one element in the list.
513 procedure Analyze_Exception_Renaming (N : Node_Id) is
514 Id : constant Node_Id := Defining_Identifier (N);
515 Nam : constant Node_Id := Name (N);
521 Set_Ekind (Id, E_Exception);
522 Set_Exception_Code (Id, Uint_0);
523 Set_Etype (Id, Standard_Exception_Type);
524 Set_Is_Pure (Id, Is_Pure (Current_Scope));
526 if not Is_Entity_Name (Nam) or else
527 Ekind (Entity (Nam)) /= E_Exception
529 Error_Msg_N ("invalid exception name in renaming", Nam);
531 if Present (Renamed_Object (Entity (Nam))) then
532 Set_Renamed_Object (Id, Renamed_Object (Entity (Nam)));
534 Set_Renamed_Object (Id, Entity (Nam));
537 end Analyze_Exception_Renaming;
539 ---------------------------
540 -- Analyze_Expanded_Name --
541 ---------------------------
543 procedure Analyze_Expanded_Name (N : Node_Id) is
545 -- If the entity pointer is already set, this is an internal node, or a
546 -- node that is analyzed more than once, after a tree modification. In
547 -- such a case there is no resolution to perform, just set the type. For
548 -- completeness, analyze prefix as well.
550 if Present (Entity (N)) then
551 if Is_Type (Entity (N)) then
552 Set_Etype (N, Entity (N));
554 Set_Etype (N, Etype (Entity (N)));
557 Analyze (Prefix (N));
560 Find_Expanded_Name (N);
562 end Analyze_Expanded_Name;
564 ---------------------------------------
565 -- Analyze_Generic_Function_Renaming --
566 ---------------------------------------
568 procedure Analyze_Generic_Function_Renaming (N : Node_Id) is
570 Analyze_Generic_Renaming (N, E_Generic_Function);
571 end Analyze_Generic_Function_Renaming;
573 --------------------------------------
574 -- Analyze_Generic_Package_Renaming --
575 --------------------------------------
577 procedure Analyze_Generic_Package_Renaming (N : Node_Id) is
579 -- Apply the Text_IO Kludge here, since we may be renaming one of the
580 -- subpackages of Text_IO, then join common routine.
582 Text_IO_Kludge (Name (N));
584 Analyze_Generic_Renaming (N, E_Generic_Package);
585 end Analyze_Generic_Package_Renaming;
587 ----------------------------------------
588 -- Analyze_Generic_Procedure_Renaming --
589 ----------------------------------------
591 procedure Analyze_Generic_Procedure_Renaming (N : Node_Id) is
593 Analyze_Generic_Renaming (N, E_Generic_Procedure);
594 end Analyze_Generic_Procedure_Renaming;
596 ------------------------------
597 -- Analyze_Generic_Renaming --
598 ------------------------------
600 procedure Analyze_Generic_Renaming
604 New_P : constant Entity_Id := Defining_Entity (N);
606 Inst : Boolean := False; -- prevent junk warning
609 if Name (N) = Error then
613 Generate_Definition (New_P);
615 if Current_Scope /= Standard_Standard then
616 Set_Is_Pure (New_P, Is_Pure (Current_Scope));
619 if Nkind (Name (N)) = N_Selected_Component then
620 Check_Generic_Child_Unit (Name (N), Inst);
625 if not Is_Entity_Name (Name (N)) then
626 Error_Msg_N ("expect entity name in renaming declaration", Name (N));
629 Old_P := Entity (Name (N));
633 Set_Ekind (New_P, K);
635 if Etype (Old_P) = Any_Type then
638 elsif Ekind (Old_P) /= K then
639 Error_Msg_N ("invalid generic unit name", Name (N));
642 if Present (Renamed_Object (Old_P)) then
643 Set_Renamed_Object (New_P, Renamed_Object (Old_P));
645 Set_Renamed_Object (New_P, Old_P);
648 Set_Is_Pure (New_P, Is_Pure (Old_P));
649 Set_Is_Preelaborated (New_P, Is_Preelaborated (Old_P));
651 Set_Etype (New_P, Etype (Old_P));
652 Set_Has_Completion (New_P);
654 if In_Open_Scopes (Old_P) then
655 Error_Msg_N ("within its scope, generic denotes its instance", N);
658 Check_Library_Unit_Renaming (N, Old_P);
660 end Analyze_Generic_Renaming;
662 -----------------------------
663 -- Analyze_Object_Renaming --
664 -----------------------------
666 procedure Analyze_Object_Renaming (N : Node_Id) is
667 Id : constant Entity_Id := Defining_Identifier (N);
669 Nam : constant Node_Id := Name (N);
673 function In_Generic_Scope (E : Entity_Id) return Boolean;
674 -- Determine whether entity E is inside a generic cope
676 ----------------------
677 -- In_Generic_Scope --
678 ----------------------
680 function In_Generic_Scope (E : Entity_Id) return Boolean is
685 while Present (S) and then S /= Standard_Standard loop
686 if Is_Generic_Unit (S) then
694 end In_Generic_Scope;
696 -- Start of processing for Analyze_Object_Renaming
703 Set_Is_Pure (Id, Is_Pure (Current_Scope));
706 -- The renaming of a component that depends on a discriminant requires
707 -- an actual subtype, because in subsequent use of the object Gigi will
708 -- be unable to locate the actual bounds. This explicit step is required
709 -- when the renaming is generated in removing side effects of an
710 -- already-analyzed expression.
712 if Nkind (Nam) = N_Selected_Component
713 and then Analyzed (Nam)
716 Dec := Build_Actual_Subtype_Of_Component (Etype (Nam), Nam);
718 if Present (Dec) then
719 Insert_Action (N, Dec);
720 T := Defining_Identifier (Dec);
724 -- Complete analysis of the subtype mark in any case, for ASIS use
726 if Present (Subtype_Mark (N)) then
727 Find_Type (Subtype_Mark (N));
730 elsif Present (Subtype_Mark (N)) then
731 Find_Type (Subtype_Mark (N));
732 T := Entity (Subtype_Mark (N));
735 if Nkind (Nam) = N_Type_Conversion
736 and then not Is_Tagged_Type (T)
739 ("renaming of conversion only allowed for tagged types", Nam);
744 -- Ada 2005 (AI-230/AI-254): Access renaming
746 else pragma Assert (Present (Access_Definition (N)));
747 T := Access_Definition
749 N => Access_Definition (N));
751 Analyze_And_Resolve (Nam, T);
753 -- Ada 2005 (AI-231): "In the case where the type is defined by an
754 -- access_definition, the renamed entity shall be of an access-to-
755 -- constant type if and only if the access_definition defines an
756 -- access-to-constant type" ARM 8.5.1(4)
758 if Constant_Present (Access_Definition (N))
759 and then not Is_Access_Constant (Etype (Nam))
761 Error_Msg_N ("(Ada 2005): the renamed object is not "
762 & "access-to-constant (RM 8.5.1(6))", N);
766 -- Special processing for renaming function return object
768 if Nkind (Nam) = N_Function_Call
769 and then Comes_From_Source (Nam)
773 -- Usage is illegal in Ada 83
777 ("(Ada 83) cannot rename function return object", Nam);
779 -- In Ada 95, warn for odd case of renaming parameterless function
780 -- call if this is not a limited type (where this is useful)
783 if Warn_On_Object_Renames_Function
784 and then No (Parameter_Associations (Nam))
785 and then not Is_Limited_Type (Etype (Nam))
788 ("?renaming function result object is suspicious",
791 ("\?function & will be called only once",
792 Nam, Entity (Name (Nam)));
794 ("\?suggest using an initialized constant object instead",
800 -- An object renaming requires an exact match of the type. Class-wide
801 -- matching is not allowed.
803 if Is_Class_Wide_Type (T)
804 and then Base_Type (Etype (Nam)) /= Base_Type (T)
811 -- (Ada 2005: AI-326): Handle wrong use of incomplete type
813 if Nkind (Nam) = N_Explicit_Dereference
814 and then Ekind (Etype (T2)) = E_Incomplete_Type
816 Error_Msg_N ("invalid use of incomplete type", Id);
822 if Ada_Version >= Ada_05
823 and then Nkind (Nam) = N_Attribute_Reference
824 and then Attribute_Name (Nam) = Name_Priority
828 elsif Ada_Version >= Ada_05
829 and then Nkind (Nam) in N_Has_Entity
832 Error_Node : Node_Id;
835 Subtyp_Decl : Node_Id;
838 if Nkind (Nam) = N_Attribute_Reference then
839 Nam_Ent := Entity (Prefix (Nam));
841 Nam_Ent := Entity (Nam);
844 Nam_Decl := Parent (Nam_Ent);
845 Subtyp_Decl := Parent (Etype (Nam_Ent));
847 if Has_Null_Exclusion (N)
848 and then not Has_Null_Exclusion (Nam_Decl)
850 -- Ada 2005 (AI-423): If the object name denotes a generic
851 -- formal object of a generic unit G, and the object renaming
852 -- declaration occurs within the body of G or within the body
853 -- of a generic unit declared within the declarative region
854 -- of G, then the declaration of the formal object of G must
855 -- have a null exclusion.
857 if Is_Formal_Object (Nam_Ent)
858 and then In_Generic_Scope (Id)
860 if Present (Subtype_Mark (Nam_Decl)) then
861 Error_Node := Subtype_Mark (Nam_Decl);
864 (Ada_Version >= Ada_05
865 and then Present (Access_Definition (Nam_Decl)));
867 Error_Node := Access_Definition (Nam_Decl);
871 ("`NOT NULL` required in formal object declaration",
873 Error_Msg_Sloc := Sloc (N);
875 ("\because of renaming # (RM 8.5.4(4))", Error_Node);
877 -- Ada 2005 (AI-423): Otherwise, the subtype of the object name
878 -- shall exclude null.
880 elsif Nkind (Subtyp_Decl) = N_Subtype_Declaration
881 and then not Has_Null_Exclusion (Subtyp_Decl)
884 ("`NOT NULL` required for subtype & (RM 8.5.1(4.6/2))",
885 Defining_Identifier (Subtyp_Decl));
891 Set_Ekind (Id, E_Variable);
892 Init_Size_Align (Id);
894 if T = Any_Type or else Etype (Nam) = Any_Type then
897 -- Verify that the renamed entity is an object or a function call. It
898 -- may have been rewritten in several ways.
900 elsif Is_Object_Reference (Nam) then
901 if Comes_From_Source (N)
902 and then Is_Dependent_Component_Of_Mutable_Object (Nam)
905 ("illegal renaming of discriminant-dependent component", Nam);
910 -- A static function call may have been folded into a literal
912 elsif Nkind (Original_Node (Nam)) = N_Function_Call
914 -- When expansion is disabled, attribute reference is not
915 -- rewritten as function call. Otherwise it may be rewritten
916 -- as a conversion, so check original node.
918 or else (Nkind (Original_Node (Nam)) = N_Attribute_Reference
919 and then Is_Function_Attribute_Name
920 (Attribute_Name (Original_Node (Nam))))
922 -- Weird but legal, equivalent to renaming a function call.
923 -- Illegal if the literal is the result of constant-folding an
924 -- attribute reference that is not a function.
926 or else (Is_Entity_Name (Nam)
927 and then Ekind (Entity (Nam)) = E_Enumeration_Literal
929 Nkind (Original_Node (Nam)) /= N_Attribute_Reference)
931 or else (Nkind (Nam) = N_Type_Conversion
932 and then Is_Tagged_Type (Entity (Subtype_Mark (Nam))))
936 elsif Nkind (Nam) = N_Type_Conversion then
938 ("renaming of conversion only allowed for tagged types", Nam);
942 elsif Ada_Version >= Ada_05
943 and then Nkind (Nam) = N_Attribute_Reference
944 and then Attribute_Name (Nam) = Name_Priority
949 Error_Msg_N ("expect object name in renaming", Nam);
954 if not Is_Variable (Nam) then
955 Set_Ekind (Id, E_Constant);
956 Set_Never_Set_In_Source (Id, True);
957 Set_Is_True_Constant (Id, True);
960 Set_Renamed_Object (Id, Nam);
961 end Analyze_Object_Renaming;
963 ------------------------------
964 -- Analyze_Package_Renaming --
965 ------------------------------
967 procedure Analyze_Package_Renaming (N : Node_Id) is
968 New_P : constant Entity_Id := Defining_Entity (N);
973 if Name (N) = Error then
977 -- Apply Text_IO kludge here, since we may be renaming one of the
978 -- children of Text_IO
980 Text_IO_Kludge (Name (N));
982 if Current_Scope /= Standard_Standard then
983 Set_Is_Pure (New_P, Is_Pure (Current_Scope));
989 if Is_Entity_Name (Name (N)) then
990 Old_P := Entity (Name (N));
995 if Etype (Old_P) = Any_Type then
997 ("expect package name in renaming", Name (N));
999 elsif Ekind (Old_P) /= E_Package
1000 and then not (Ekind (Old_P) = E_Generic_Package
1001 and then In_Open_Scopes (Old_P))
1003 if Ekind (Old_P) = E_Generic_Package then
1005 ("generic package cannot be renamed as a package", Name (N));
1007 Error_Msg_Sloc := Sloc (Old_P);
1009 ("expect package name in renaming, found& declared#",
1013 -- Set basic attributes to minimize cascaded errors
1015 Set_Ekind (New_P, E_Package);
1016 Set_Etype (New_P, Standard_Void_Type);
1019 -- Entities in the old package are accessible through the renaming
1020 -- entity. The simplest implementation is to have both packages share
1023 Set_Ekind (New_P, E_Package);
1024 Set_Etype (New_P, Standard_Void_Type);
1026 if Present (Renamed_Object (Old_P)) then
1027 Set_Renamed_Object (New_P, Renamed_Object (Old_P));
1029 Set_Renamed_Object (New_P, Old_P);
1032 Set_Has_Completion (New_P);
1034 Set_First_Entity (New_P, First_Entity (Old_P));
1035 Set_Last_Entity (New_P, Last_Entity (Old_P));
1036 Set_First_Private_Entity (New_P, First_Private_Entity (Old_P));
1037 Check_Library_Unit_Renaming (N, Old_P);
1038 Generate_Reference (Old_P, Name (N));
1040 -- If this is the renaming declaration of a package instantiation
1041 -- within itself, it is the declaration that ends the list of actuals
1042 -- for the instantiation. At this point, the subtypes that rename
1043 -- the actuals are flagged as generic, to avoid spurious ambiguities
1044 -- if the actuals for two distinct formals happen to coincide. If
1045 -- the actual is a private type, the subtype has a private completion
1046 -- that is flagged in the same fashion.
1048 -- Resolution is identical to what is was in the original generic.
1049 -- On exit from the generic instance, these are turned into regular
1050 -- subtypes again, so they are compatible with types in their class.
1052 if not Is_Generic_Instance (Old_P) then
1055 Spec := Specification (Unit_Declaration_Node (Old_P));
1058 if Nkind (Spec) = N_Package_Specification
1059 and then Present (Generic_Parent (Spec))
1060 and then Old_P = Current_Scope
1061 and then Chars (New_P) = Chars (Generic_Parent (Spec))
1067 E := First_Entity (Old_P);
1072 and then Nkind (Parent (E)) = N_Subtype_Declaration
1074 Set_Is_Generic_Actual_Type (E);
1076 if Is_Private_Type (E)
1077 and then Present (Full_View (E))
1079 Set_Is_Generic_Actual_Type (Full_View (E));
1089 end Analyze_Package_Renaming;
1091 -------------------------------
1092 -- Analyze_Renamed_Character --
1093 -------------------------------
1095 procedure Analyze_Renamed_Character
1100 C : constant Node_Id := Name (N);
1103 if Ekind (New_S) = E_Function then
1104 Resolve (C, Etype (New_S));
1107 Check_Frozen_Renaming (N, New_S);
1111 Error_Msg_N ("character literal can only be renamed as function", N);
1113 end Analyze_Renamed_Character;
1115 ---------------------------------
1116 -- Analyze_Renamed_Dereference --
1117 ---------------------------------
1119 procedure Analyze_Renamed_Dereference
1124 Nam : constant Node_Id := Name (N);
1125 P : constant Node_Id := Prefix (Nam);
1131 if not Is_Overloaded (P) then
1132 if Ekind (Etype (Nam)) /= E_Subprogram_Type
1133 or else not Type_Conformant (Etype (Nam), New_S) then
1134 Error_Msg_N ("designated type does not match specification", P);
1143 Get_First_Interp (Nam, Ind, It);
1145 while Present (It.Nam) loop
1147 if Ekind (It.Nam) = E_Subprogram_Type
1148 and then Type_Conformant (It.Nam, New_S) then
1150 if Typ /= Any_Id then
1151 Error_Msg_N ("ambiguous renaming", P);
1158 Get_Next_Interp (Ind, It);
1161 if Typ = Any_Type then
1162 Error_Msg_N ("designated type does not match specification", P);
1167 Check_Frozen_Renaming (N, New_S);
1171 end Analyze_Renamed_Dereference;
1173 ---------------------------
1174 -- Analyze_Renamed_Entry --
1175 ---------------------------
1177 procedure Analyze_Renamed_Entry
1182 Nam : constant Node_Id := Name (N);
1183 Sel : constant Node_Id := Selector_Name (Nam);
1187 if Entity (Sel) = Any_Id then
1189 -- Selector is undefined on prefix. Error emitted already
1191 Set_Has_Completion (New_S);
1195 -- Otherwise find renamed entity and build body of New_S as a call to it
1197 Old_S := Find_Renamed_Entity (N, Selector_Name (Nam), New_S);
1199 if Old_S = Any_Id then
1200 Error_Msg_N (" no subprogram or entry matches specification", N);
1203 Check_Subtype_Conformant (New_S, Old_S, N);
1204 Generate_Reference (New_S, Defining_Entity (N), 'b');
1205 Style.Check_Identifier (Defining_Entity (N), New_S);
1208 -- Only mode conformance required for a renaming_as_declaration
1210 Check_Mode_Conformant (New_S, Old_S, N);
1213 Inherit_Renamed_Profile (New_S, Old_S);
1216 Set_Convention (New_S, Convention (Old_S));
1217 Set_Has_Completion (New_S, Inside_A_Generic);
1220 Check_Frozen_Renaming (N, New_S);
1222 end Analyze_Renamed_Entry;
1224 -----------------------------------
1225 -- Analyze_Renamed_Family_Member --
1226 -----------------------------------
1228 procedure Analyze_Renamed_Family_Member
1233 Nam : constant Node_Id := Name (N);
1234 P : constant Node_Id := Prefix (Nam);
1238 if (Is_Entity_Name (P) and then Ekind (Entity (P)) = E_Entry_Family)
1239 or else (Nkind (P) = N_Selected_Component
1241 Ekind (Entity (Selector_Name (P))) = E_Entry_Family)
1243 if Is_Entity_Name (P) then
1244 Old_S := Entity (P);
1246 Old_S := Entity (Selector_Name (P));
1249 if not Entity_Matches_Spec (Old_S, New_S) then
1250 Error_Msg_N ("entry family does not match specification", N);
1253 Check_Subtype_Conformant (New_S, Old_S, N);
1254 Generate_Reference (New_S, Defining_Entity (N), 'b');
1255 Style.Check_Identifier (Defining_Entity (N), New_S);
1259 Error_Msg_N ("no entry family matches specification", N);
1262 Set_Has_Completion (New_S, Inside_A_Generic);
1265 Check_Frozen_Renaming (N, New_S);
1267 end Analyze_Renamed_Family_Member;
1269 ---------------------------------
1270 -- Analyze_Subprogram_Renaming --
1271 ---------------------------------
1273 procedure Analyze_Subprogram_Renaming (N : Node_Id) is
1274 Formal_Spec : constant Node_Id := Corresponding_Formal_Spec (N);
1275 Is_Actual : constant Boolean := Present (Formal_Spec);
1276 Inst_Node : Node_Id := Empty;
1277 Nam : constant Node_Id := Name (N);
1279 Old_S : Entity_Id := Empty;
1280 Rename_Spec : Entity_Id;
1281 Save_AV : constant Ada_Version_Type := Ada_Version;
1282 Save_AV_Exp : constant Ada_Version_Type := Ada_Version_Explicit;
1283 Spec : constant Node_Id := Specification (N);
1285 procedure Check_Null_Exclusion
1288 -- Ada 2005 (AI-423): Given renaming Ren of subprogram Sub, check the
1289 -- following AI rules:
1291 -- If Ren is a renaming of a formal subprogram and one of its
1292 -- parameters has a null exclusion, then the corresponding formal
1293 -- in Sub must also have one. Otherwise the subtype of the Sub's
1294 -- formal parameter must exclude null.
1296 -- If Ren is a renaming of a formal function and its retrun
1297 -- profile has a null exclusion, then Sub's return profile must
1298 -- have one. Otherwise the subtype of Sub's return profile must
1301 function Original_Subprogram (Subp : Entity_Id) return Entity_Id;
1302 -- Find renamed entity when the declaration is a renaming_as_body and
1303 -- the renamed entity may itself be a renaming_as_body. Used to enforce
1304 -- rule that a renaming_as_body is illegal if the declaration occurs
1305 -- before the subprogram it completes is frozen, and renaming indirectly
1306 -- renames the subprogram itself.(Defect Report 8652/0027).
1308 --------------------------
1309 -- Check_Null_Exclusion --
1310 --------------------------
1312 procedure Check_Null_Exclusion
1316 Ren_Formal : Entity_Id;
1317 Sub_Formal : Entity_Id;
1322 Ren_Formal := First_Formal (Ren);
1323 Sub_Formal := First_Formal (Sub);
1324 while Present (Ren_Formal)
1325 and then Present (Sub_Formal)
1327 if Has_Null_Exclusion (Parent (Ren_Formal))
1329 not (Has_Null_Exclusion (Parent (Sub_Formal))
1330 or else Can_Never_Be_Null (Etype (Sub_Formal)))
1333 ("`NOT NULL` required for parameter &",
1334 Parent (Sub_Formal), Sub_Formal);
1337 Next_Formal (Ren_Formal);
1338 Next_Formal (Sub_Formal);
1341 -- Return profile check
1343 if Nkind (Parent (Ren)) = N_Function_Specification
1344 and then Nkind (Parent (Sub)) = N_Function_Specification
1345 and then Has_Null_Exclusion (Parent (Ren))
1347 not (Has_Null_Exclusion (Parent (Sub))
1348 or else Can_Never_Be_Null (Etype (Sub)))
1351 ("return must specify `NOT NULL`",
1352 Result_Definition (Parent (Sub)));
1354 end Check_Null_Exclusion;
1356 -------------------------
1357 -- Original_Subprogram --
1358 -------------------------
1360 function Original_Subprogram (Subp : Entity_Id) return Entity_Id is
1361 Orig_Decl : Node_Id;
1362 Orig_Subp : Entity_Id;
1365 -- First case: renamed entity is itself a renaming
1367 if Present (Alias (Subp)) then
1368 return Alias (Subp);
1371 Nkind (Unit_Declaration_Node (Subp)) = N_Subprogram_Declaration
1373 (Corresponding_Body (Unit_Declaration_Node (Subp)))
1375 -- Check if renamed entity is a renaming_as_body
1378 Unit_Declaration_Node
1379 (Corresponding_Body (Unit_Declaration_Node (Subp)));
1381 if Nkind (Orig_Decl) = N_Subprogram_Renaming_Declaration then
1382 Orig_Subp := Entity (Name (Orig_Decl));
1384 if Orig_Subp = Rename_Spec then
1386 -- Circularity detected
1391 return (Original_Subprogram (Orig_Subp));
1399 end Original_Subprogram;
1401 -- Start of processing for Analyze_Subprogram_Renaming
1404 -- We must test for the attribute renaming case before the Analyze
1405 -- call because otherwise Sem_Attr will complain that the attribute
1406 -- is missing an argument when it is analyzed.
1408 if Nkind (Nam) = N_Attribute_Reference then
1410 -- In the case of an abstract formal subprogram association, rewrite
1411 -- an actual given by a stream attribute as the name of the
1412 -- corresponding stream primitive of the type.
1414 -- In a generic context the stream operations are not generated, and
1415 -- this must be treated as a normal attribute reference, to be
1416 -- expanded in subsequent instantiations.
1418 if Is_Actual and then Is_Abstract_Subprogram (Formal_Spec)
1419 and then Expander_Active
1422 Stream_Prim : Entity_Id;
1423 Prefix_Type : constant Entity_Id := Entity (Prefix (Nam));
1426 -- The class-wide forms of the stream attributes are not
1427 -- primitive dispatching operations (even though they
1428 -- internally dispatch to a stream attribute).
1430 if Is_Class_Wide_Type (Prefix_Type) then
1432 ("attribute must be a primitive dispatching operation",
1437 -- Retrieve the primitive subprogram associated with the
1438 -- attribute. This can only be a stream attribute, since those
1439 -- are the only ones that are dispatching (and the actual for
1440 -- an abstract formal subprogram must be dispatching
1443 case Attribute_Name (Nam) is
1446 Find_Prim_Op (Prefix_Type, TSS_Stream_Input);
1449 Find_Prim_Op (Prefix_Type, TSS_Stream_Output);
1452 Find_Prim_Op (Prefix_Type, TSS_Stream_Read);
1455 Find_Prim_Op (Prefix_Type, TSS_Stream_Write);
1458 ("attribute must be a primitive dispatching operation",
1463 -- Rewrite the attribute into the name of its corresponding
1464 -- primitive dispatching subprogram. We can then proceed with
1465 -- the usual processing for subprogram renamings.
1468 Prim_Name : constant Node_Id :=
1469 Make_Identifier (Sloc (Nam),
1470 Chars => Chars (Stream_Prim));
1472 Set_Entity (Prim_Name, Stream_Prim);
1473 Rewrite (Nam, Prim_Name);
1478 -- Normal processing for a renaming of an attribute
1481 Attribute_Renaming (N);
1486 -- Check whether this declaration corresponds to the instantiation
1487 -- of a formal subprogram.
1489 -- If this is an instantiation, the corresponding actual is frozen and
1490 -- error messages can be made more precise. If this is a default
1491 -- subprogram, the entity is already established in the generic, and is
1492 -- not retrieved by visibility. If it is a default with a box, the
1493 -- candidate interpretations, if any, have been collected when building
1494 -- the renaming declaration. If overloaded, the proper interpretation is
1495 -- determined in Find_Renamed_Entity. If the entity is an operator,
1496 -- Find_Renamed_Entity applies additional visibility checks.
1499 Inst_Node := Unit_Declaration_Node (Formal_Spec);
1501 if Is_Entity_Name (Nam)
1502 and then Present (Entity (Nam))
1503 and then not Comes_From_Source (Nam)
1504 and then not Is_Overloaded (Nam)
1506 Old_S := Entity (Nam);
1507 New_S := Analyze_Subprogram_Specification (Spec);
1511 if Ekind (Entity (Nam)) = E_Operator then
1515 if Box_Present (Inst_Node) then
1516 Old_S := Find_Renamed_Entity (N, Name (N), New_S, Is_Actual);
1518 -- If there is an immediately visible homonym of the operator
1519 -- and the declaration has a default, this is worth a warning
1520 -- because the user probably did not intend to get the pre-
1521 -- defined operator, visible in the generic declaration. To
1522 -- find if there is an intended candidate, analyze the renaming
1523 -- again in the current context.
1525 elsif Scope (Old_S) = Standard_Standard
1526 and then Present (Default_Name (Inst_Node))
1529 Decl : constant Node_Id := New_Copy_Tree (N);
1533 Set_Entity (Name (Decl), Empty);
1534 Analyze (Name (Decl));
1536 Find_Renamed_Entity (Decl, Name (Decl), New_S, True);
1539 and then In_Open_Scopes (Scope (Hidden))
1540 and then Is_Immediately_Visible (Hidden)
1541 and then Comes_From_Source (Hidden)
1542 and then Hidden /= Old_S
1544 Error_Msg_Sloc := Sloc (Hidden);
1545 Error_Msg_N ("?default subprogram is resolved " &
1546 "in the generic declaration " &
1547 "(RM 12.6(17))", N);
1548 Error_Msg_NE ("\?and will not use & #", N, Hidden);
1556 New_S := Analyze_Subprogram_Specification (Spec);
1560 -- Renamed entity must be analyzed first, to avoid being hidden by
1561 -- new name (which might be the same in a generic instance).
1565 -- The renaming defines a new overloaded entity, which is analyzed
1566 -- like a subprogram declaration.
1568 New_S := Analyze_Subprogram_Specification (Spec);
1571 if Current_Scope /= Standard_Standard then
1572 Set_Is_Pure (New_S, Is_Pure (Current_Scope));
1575 Rename_Spec := Find_Corresponding_Spec (N);
1577 if Present (Rename_Spec) then
1579 -- Renaming_As_Body. Renaming declaration is the completion of
1580 -- the declaration of Rename_Spec. We will build an actual body
1581 -- for it at the freezing point.
1583 Set_Corresponding_Spec (N, Rename_Spec);
1585 if Nkind (Unit_Declaration_Node (Rename_Spec)) =
1586 N_Abstract_Subprogram_Declaration
1588 -- Input and Output stream functions are abstract if the object
1589 -- type is abstract. However, these functions may receive explicit
1590 -- declarations in representation clauses, making the attribute
1591 -- subprograms usable as defaults in subsequent type extensions.
1592 -- In this case we rewrite the declaration to make the subprogram
1593 -- non-abstract. We remove the previous declaration, and insert
1594 -- the new one at the point of the renaming, to prevent premature
1595 -- access to unfrozen types. The new declaration reuses the
1596 -- specification of the previous one, and must not be analyzed.
1598 pragma Assert (Is_TSS (Rename_Spec, TSS_Stream_Output)
1599 or else Is_TSS (Rename_Spec, TSS_Stream_Input));
1602 Old_Decl : constant Node_Id :=
1603 Unit_Declaration_Node (Rename_Spec);
1604 New_Decl : constant Node_Id :=
1605 Make_Subprogram_Declaration (Sloc (N),
1607 Relocate_Node (Specification (Old_Decl)));
1610 Insert_After (N, New_Decl);
1611 Set_Is_Abstract_Subprogram (Rename_Spec, False);
1612 Set_Analyzed (New_Decl);
1616 Set_Corresponding_Body (Unit_Declaration_Node (Rename_Spec), New_S);
1618 if Ada_Version = Ada_83 and then Comes_From_Source (N) then
1619 Error_Msg_N ("(Ada 83) renaming cannot serve as a body", N);
1622 Set_Convention (New_S, Convention (Rename_Spec));
1623 Check_Fully_Conformant (New_S, Rename_Spec);
1624 Set_Public_Status (New_S);
1626 -- Indicate that the entity in the declaration functions like the
1627 -- corresponding body, and is not a new entity. The body will be
1628 -- constructed later at the freeze point, so indicate that the
1629 -- completion has not been seen yet.
1631 Set_Ekind (New_S, E_Subprogram_Body);
1632 New_S := Rename_Spec;
1633 Set_Has_Completion (Rename_Spec, False);
1635 -- Ada 2005: check overriding indicator
1637 if Must_Override (Specification (N))
1638 and then not Is_Overriding_Operation (Rename_Spec)
1640 Error_Msg_NE ("subprogram& is not overriding", N, Rename_Spec);
1642 elsif Must_Not_Override (Specification (N))
1643 and then Is_Overriding_Operation (Rename_Spec)
1646 ("subprogram& overrides inherited operation", N, Rename_Spec);
1650 Generate_Definition (New_S);
1651 New_Overloaded_Entity (New_S);
1653 if Is_Entity_Name (Nam)
1654 and then Is_Intrinsic_Subprogram (Entity (Nam))
1658 Check_Delayed_Subprogram (New_S);
1662 -- There is no need for elaboration checks on the new entity, which may
1663 -- be called before the next freezing point where the body will appear.
1664 -- Elaboration checks refer to the real entity, not the one created by
1665 -- the renaming declaration.
1667 Set_Kill_Elaboration_Checks (New_S, True);
1669 if Etype (Nam) = Any_Type then
1670 Set_Has_Completion (New_S);
1673 elsif Nkind (Nam) = N_Selected_Component then
1675 -- Renamed entity is an entry or protected subprogram. For those
1676 -- cases an explicit body is built (at the point of freezing of this
1677 -- entity) that contains a call to the renamed entity.
1679 Analyze_Renamed_Entry (N, New_S, Present (Rename_Spec));
1682 elsif Nkind (Nam) = N_Explicit_Dereference then
1684 -- Renamed entity is designated by access_to_subprogram expression.
1685 -- Must build body to encapsulate call, as in the entry case.
1687 Analyze_Renamed_Dereference (N, New_S, Present (Rename_Spec));
1690 elsif Nkind (Nam) = N_Indexed_Component then
1691 Analyze_Renamed_Family_Member (N, New_S, Present (Rename_Spec));
1694 elsif Nkind (Nam) = N_Character_Literal then
1695 Analyze_Renamed_Character (N, New_S, Present (Rename_Spec));
1698 elsif (not Is_Entity_Name (Nam)
1699 and then Nkind (Nam) /= N_Operator_Symbol)
1700 or else not Is_Overloadable (Entity (Nam))
1702 Error_Msg_N ("expect valid subprogram name in renaming", N);
1706 -- Find the renamed entity that matches the given specification. Disable
1707 -- Ada_83 because there is no requirement of full conformance between
1708 -- renamed entity and new entity, even though the same circuit is used.
1710 -- This is a bit of a kludge, which introduces a really irregular use of
1711 -- Ada_Version[_Explicit]. Would be nice to find cleaner way to do this
1714 Ada_Version := Ada_Version_Type'Max (Ada_Version, Ada_95);
1715 Ada_Version_Explicit := Ada_Version;
1718 Old_S := Find_Renamed_Entity (N, Name (N), New_S, Is_Actual);
1720 -- When the renamed subprogram is overloaded and used as an actual
1721 -- of a generic, its entity is set to the first available homonym.
1722 -- We must first disambiguate the name, then set the proper entity.
1725 and then Is_Overloaded (Nam)
1727 Set_Entity (Nam, Old_S);
1731 -- Most common case: subprogram renames subprogram. No body is generated
1732 -- in this case, so we must indicate the declaration is complete as is.
1734 if No (Rename_Spec) then
1735 Set_Has_Completion (New_S);
1736 Set_Is_Pure (New_S, Is_Pure (Entity (Nam)));
1737 Set_Is_Preelaborated (New_S, Is_Preelaborated (Entity (Nam)));
1739 -- Ada 2005 (AI-423): Check the consistency of null exclusions
1740 -- between a subprogram and its correct renaming.
1742 -- Note: the Any_Id check is a guard that prevents compiler crashes
1743 -- when performing a null exclusion check between a renaming and a
1744 -- renamed subprogram that has been found to be illegal.
1746 if Ada_Version >= Ada_05
1747 and then Entity (Nam) /= Any_Id
1749 Check_Null_Exclusion
1751 Sub => Entity (Nam));
1755 if Old_S /= Any_Id then
1757 and then From_Default (N)
1759 -- This is an implicit reference to the default actual
1761 Generate_Reference (Old_S, Nam, Typ => 'i', Force => True);
1763 Generate_Reference (Old_S, Nam);
1766 -- For a renaming-as-body, require subtype conformance, but if the
1767 -- declaration being completed has not been frozen, then inherit the
1768 -- convention of the renamed subprogram prior to checking conformance
1769 -- (unless the renaming has an explicit convention established; the
1770 -- rule stated in the RM doesn't seem to address this ???).
1772 if Present (Rename_Spec) then
1773 Generate_Reference (Rename_Spec, Defining_Entity (Spec), 'b');
1774 Style.Check_Identifier (Defining_Entity (Spec), Rename_Spec);
1776 if not Is_Frozen (Rename_Spec) then
1777 if not Has_Convention_Pragma (Rename_Spec) then
1778 Set_Convention (New_S, Convention (Old_S));
1781 if Ekind (Old_S) /= E_Operator then
1782 Check_Mode_Conformant (New_S, Old_S, Spec);
1785 if Original_Subprogram (Old_S) = Rename_Spec then
1786 Error_Msg_N ("unfrozen subprogram cannot rename itself ", N);
1789 Check_Subtype_Conformant (New_S, Old_S, Spec);
1792 Check_Frozen_Renaming (N, Rename_Spec);
1794 -- Check explicitly that renamed entity is not intrinsic, because
1795 -- in in a generic the renamed body is not built. In this case,
1796 -- the renaming_as_body is a completion.
1798 if Inside_A_Generic then
1799 if Is_Frozen (Rename_Spec)
1800 and then Is_Intrinsic_Subprogram (Old_S)
1803 ("subprogram in renaming_as_body cannot be intrinsic",
1807 Set_Has_Completion (Rename_Spec);
1810 elsif Ekind (Old_S) /= E_Operator then
1811 Check_Mode_Conformant (New_S, Old_S);
1814 and then Error_Posted (New_S)
1816 Error_Msg_NE ("invalid actual subprogram: & #!", N, Old_S);
1820 if No (Rename_Spec) then
1822 -- The parameter profile of the new entity is that of the renamed
1823 -- entity: the subtypes given in the specification are irrelevant.
1825 Inherit_Renamed_Profile (New_S, Old_S);
1827 -- A call to the subprogram is transformed into a call to the
1828 -- renamed entity. This is transitive if the renamed entity is
1829 -- itself a renaming.
1831 if Present (Alias (Old_S)) then
1832 Set_Alias (New_S, Alias (Old_S));
1834 Set_Alias (New_S, Old_S);
1837 -- Note that we do not set Is_Intrinsic_Subprogram if we have a
1838 -- renaming as body, since the entity in this case is not an
1839 -- intrinsic (it calls an intrinsic, but we have a real body for
1840 -- this call, and it is in this body that the required intrinsic
1841 -- processing will take place).
1843 -- Also, if this is a renaming of inequality, the renamed operator
1844 -- is intrinsic, but what matters is the corresponding equality
1845 -- operator, which may be user-defined.
1847 Set_Is_Intrinsic_Subprogram
1849 Is_Intrinsic_Subprogram (Old_S)
1851 (Chars (Old_S) /= Name_Op_Ne
1852 or else Ekind (Old_S) = E_Operator
1854 Is_Intrinsic_Subprogram
1855 (Corresponding_Equality (Old_S))));
1857 if Ekind (Alias (New_S)) = E_Operator then
1858 Set_Has_Delayed_Freeze (New_S, False);
1861 -- If the renaming corresponds to an association for an abstract
1862 -- formal subprogram, then various attributes must be set to
1863 -- indicate that the renaming is an abstract dispatching operation
1864 -- with a controlling type.
1866 if Is_Actual and then Is_Abstract_Subprogram (Formal_Spec) then
1868 -- Mark the renaming as abstract here, so Find_Dispatching_Type
1869 -- see it as corresponding to a generic association for a
1870 -- formal abstract subprogram
1872 Set_Is_Abstract_Subprogram (New_S);
1875 New_S_Ctrl_Type : constant Entity_Id :=
1876 Find_Dispatching_Type (New_S);
1877 Old_S_Ctrl_Type : constant Entity_Id :=
1878 Find_Dispatching_Type (Old_S);
1881 if Old_S_Ctrl_Type /= New_S_Ctrl_Type then
1883 ("actual must be dispatching subprogram for type&",
1884 Nam, New_S_Ctrl_Type);
1887 Set_Is_Dispatching_Operation (New_S);
1888 Check_Controlling_Formals (New_S_Ctrl_Type, New_S);
1890 -- If the actual in the formal subprogram is itself a
1891 -- formal abstract subprogram association, there's no
1892 -- dispatch table component or position to inherit.
1894 if Present (DTC_Entity (Old_S)) then
1895 Set_DTC_Entity (New_S, DTC_Entity (Old_S));
1896 Set_DT_Position (New_S, DT_Position (Old_S));
1904 and then (Old_S = New_S
1905 or else (Nkind (Nam) /= N_Expanded_Name
1906 and then Chars (Old_S) = Chars (New_S)))
1908 Error_Msg_N ("subprogram cannot rename itself", N);
1911 Set_Convention (New_S, Convention (Old_S));
1913 if Is_Abstract_Subprogram (Old_S) then
1914 if Present (Rename_Spec) then
1916 ("a renaming-as-body cannot rename an abstract subprogram",
1918 Set_Has_Completion (Rename_Spec);
1920 Set_Is_Abstract_Subprogram (New_S);
1924 Check_Library_Unit_Renaming (N, Old_S);
1926 -- Pathological case: procedure renames entry in the scope of its
1927 -- task. Entry is given by simple name, but body must be built for
1928 -- procedure. Of course if called it will deadlock.
1930 if Ekind (Old_S) = E_Entry then
1931 Set_Has_Completion (New_S, False);
1932 Set_Alias (New_S, Empty);
1936 Freeze_Before (N, Old_S);
1937 Set_Has_Delayed_Freeze (New_S, False);
1938 Freeze_Before (N, New_S);
1940 -- An abstract subprogram is only allowed as an actual in the case
1941 -- where the formal subprogram is also abstract.
1943 if (Ekind (Old_S) = E_Procedure or else Ekind (Old_S) = E_Function)
1944 and then Is_Abstract_Subprogram (Old_S)
1945 and then not Is_Abstract_Subprogram (Formal_Spec)
1948 ("abstract subprogram not allowed as generic actual", Nam);
1953 -- A common error is to assume that implicit operators for types are
1954 -- defined in Standard, or in the scope of a subtype. In those cases
1955 -- where the renamed entity is given with an expanded name, it is
1956 -- worth mentioning that operators for the type are not declared in
1957 -- the scope given by the prefix.
1959 if Nkind (Nam) = N_Expanded_Name
1960 and then Nkind (Selector_Name (Nam)) = N_Operator_Symbol
1961 and then Scope (Entity (Nam)) = Standard_Standard
1964 T : constant Entity_Id :=
1965 Base_Type (Etype (First_Formal (New_S)));
1967 Error_Msg_Node_2 := Prefix (Nam);
1969 ("operator for type& is not declared in&", Prefix (Nam), T);
1974 ("no visible subprogram matches the specification for&",
1978 if Present (Candidate_Renaming) then
1984 F1 := First_Formal (Candidate_Renaming);
1985 F2 := First_Formal (New_S);
1987 while Present (F1) and then Present (F2) loop
1992 if Present (F1) and then Present (Default_Value (F1)) then
1993 if Present (Next_Formal (F1)) then
1995 ("\missing specification for &" &
1996 " and other formals with defaults", Spec, F1);
1999 ("\missing specification for &", Spec, F1);
2006 -- Ada 2005 AI 404: if the new subprogram is dispatching, verify that
2007 -- controlling access parameters are known non-null for the renamed
2008 -- subprogram. Test also applies to a subprogram instantiation that
2009 -- is dispatching. Test is skipped if some previous error was detected
2010 -- that set Old_S to Any_Id.
2012 if Ada_Version >= Ada_05
2013 and then Old_S /= Any_Id
2014 and then not Is_Dispatching_Operation (Old_S)
2015 and then Is_Dispatching_Operation (New_S)
2022 Old_F := First_Formal (Old_S);
2023 New_F := First_Formal (New_S);
2024 while Present (Old_F) loop
2025 if Ekind (Etype (Old_F)) = E_Anonymous_Access_Type
2026 and then Is_Controlling_Formal (New_F)
2027 and then not Can_Never_Be_Null (Old_F)
2029 Error_Msg_N ("access parameter is controlling,", New_F);
2031 ("\corresponding parameter of& "
2032 & "must be explicitly null excluding", New_F, Old_S);
2035 Next_Formal (Old_F);
2036 Next_Formal (New_F);
2041 -- A useful warning, suggested by Ada Bug Finder (Ada-Europe 2005)
2043 if Comes_From_Source (N)
2044 and then Present (Old_S)
2045 and then Nkind (Old_S) = N_Defining_Operator_Symbol
2046 and then Nkind (New_S) = N_Defining_Operator_Symbol
2047 and then Chars (Old_S) /= Chars (New_S)
2050 ("?& is being renamed as a different operator",
2054 -- Another warning or some utility: if the new subprogram as the same
2055 -- name as the old one, the old one is not hidden by an outer homograph,
2056 -- the new one is not a public symbol, and the old one is otherwise
2057 -- directly visible, the renaming is superfluous.
2059 if Chars (Old_S) = Chars (New_S)
2060 and then Comes_From_Source (N)
2061 and then Scope (Old_S) /= Standard_Standard
2062 and then Warn_On_Redundant_Constructs
2064 (Is_Immediately_Visible (Old_S)
2065 or else Is_Potentially_Use_Visible (Old_S))
2066 and then Is_Overloadable (Current_Scope)
2067 and then Chars (Current_Scope) /= Chars (Old_S)
2070 ("?redundant renaming, entity is directly visible", Name (N));
2073 Ada_Version := Save_AV;
2074 Ada_Version_Explicit := Save_AV_Exp;
2075 end Analyze_Subprogram_Renaming;
2077 -------------------------
2078 -- Analyze_Use_Package --
2079 -------------------------
2081 -- Resolve the package names in the use clause, and make all the visible
2082 -- entities defined in the package potentially use-visible. If the package
2083 -- is already in use from a previous use clause, its visible entities are
2084 -- already use-visible. In that case, mark the occurrence as a redundant
2085 -- use. If the package is an open scope, i.e. if the use clause occurs
2086 -- within the package itself, ignore it.
2088 procedure Analyze_Use_Package (N : Node_Id) is
2089 Pack_Name : Node_Id;
2092 -- Start of processing for Analyze_Use_Package
2095 Set_Hidden_By_Use_Clause (N, No_Elist);
2097 -- Use clause is not allowed in a spec of a predefined package
2098 -- declaration except that packages whose file name starts a-n are OK
2099 -- (these are children of Ada.Numerics, and such packages are never
2100 -- loaded by Rtsfind).
2102 if Is_Predefined_File_Name (Unit_File_Name (Current_Sem_Unit))
2103 and then Name_Buffer (1 .. 3) /= "a-n"
2105 Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Declaration
2107 Error_Msg_N ("use clause not allowed in predefined spec", N);
2110 -- Chain clause to list of use clauses in current scope
2112 if Nkind (Parent (N)) /= N_Compilation_Unit then
2113 Chain_Use_Clause (N);
2116 -- Loop through package names to identify referenced packages
2118 Pack_Name := First (Names (N));
2119 while Present (Pack_Name) loop
2120 Analyze (Pack_Name);
2122 if Nkind (Parent (N)) = N_Compilation_Unit
2123 and then Nkind (Pack_Name) = N_Expanded_Name
2129 Pref := Prefix (Pack_Name);
2130 while Nkind (Pref) = N_Expanded_Name loop
2131 Pref := Prefix (Pref);
2134 if Entity (Pref) = Standard_Standard then
2136 ("predefined package Standard cannot appear"
2137 & " in a context clause", Pref);
2145 -- Loop through package names to mark all entities as potentially
2148 Pack_Name := First (Names (N));
2149 while Present (Pack_Name) loop
2150 if Is_Entity_Name (Pack_Name) then
2151 Pack := Entity (Pack_Name);
2153 if Ekind (Pack) /= E_Package
2154 and then Etype (Pack) /= Any_Type
2156 if Ekind (Pack) = E_Generic_Package then
2158 ("a generic package is not allowed in a use clause",
2161 Error_Msg_N ("& is not a usable package", Pack_Name);
2165 if Nkind (Parent (N)) = N_Compilation_Unit then
2166 Check_In_Previous_With_Clause (N, Pack_Name);
2169 if Applicable_Use (Pack_Name) then
2170 Use_One_Package (Pack, N);
2177 end Analyze_Use_Package;
2179 ----------------------
2180 -- Analyze_Use_Type --
2181 ----------------------
2183 procedure Analyze_Use_Type (N : Node_Id) is
2187 Set_Hidden_By_Use_Clause (N, No_Elist);
2189 -- Chain clause to list of use clauses in current scope
2191 if Nkind (Parent (N)) /= N_Compilation_Unit then
2192 Chain_Use_Clause (N);
2195 Id := First (Subtype_Marks (N));
2196 while Present (Id) loop
2199 if Entity (Id) /= Any_Type then
2202 if Nkind (Parent (N)) = N_Compilation_Unit then
2203 if Nkind (Id) = N_Identifier then
2204 Error_Msg_N ("type is not directly visible", Id);
2206 elsif Is_Child_Unit (Scope (Entity (Id)))
2207 and then Scope (Entity (Id)) /= System_Aux_Id
2209 Check_In_Previous_With_Clause (N, Prefix (Id));
2216 end Analyze_Use_Type;
2218 --------------------
2219 -- Applicable_Use --
2220 --------------------
2222 function Applicable_Use (Pack_Name : Node_Id) return Boolean is
2223 Pack : constant Entity_Id := Entity (Pack_Name);
2226 if In_Open_Scopes (Pack) then
2229 elsif In_Use (Pack) then
2230 Note_Redundant_Use (Pack_Name);
2233 elsif Present (Renamed_Object (Pack))
2234 and then In_Use (Renamed_Object (Pack))
2236 Note_Redundant_Use (Pack_Name);
2244 ------------------------
2245 -- Attribute_Renaming --
2246 ------------------------
2248 procedure Attribute_Renaming (N : Node_Id) is
2249 Loc : constant Source_Ptr := Sloc (N);
2250 Nam : constant Node_Id := Name (N);
2251 Spec : constant Node_Id := Specification (N);
2252 New_S : constant Entity_Id := Defining_Unit_Name (Spec);
2253 Aname : constant Name_Id := Attribute_Name (Nam);
2255 Form_Num : Nat := 0;
2256 Expr_List : List_Id := No_List;
2258 Attr_Node : Node_Id;
2259 Body_Node : Node_Id;
2260 Param_Spec : Node_Id;
2263 Generate_Definition (New_S);
2265 -- This procedure is called in the context of subprogram renaming,
2266 -- and thus the attribute must be one that is a subprogram. All of
2267 -- those have at least one formal parameter, with the singular
2268 -- exception of AST_Entry (which is a real oddity, it is odd that
2269 -- this can be renamed at all!)
2271 if not Is_Non_Empty_List (Parameter_Specifications (Spec)) then
2272 if Aname /= Name_AST_Entry then
2274 ("subprogram renaming an attribute must have formals", N);
2279 Param_Spec := First (Parameter_Specifications (Spec));
2280 while Present (Param_Spec) loop
2281 Form_Num := Form_Num + 1;
2283 if Nkind (Parameter_Type (Param_Spec)) /= N_Access_Definition then
2284 Find_Type (Parameter_Type (Param_Spec));
2286 -- The profile of the new entity denotes the base type (s) of
2287 -- the types given in the specification. For access parameters
2288 -- there are no subtypes involved.
2290 Rewrite (Parameter_Type (Param_Spec),
2292 (Base_Type (Entity (Parameter_Type (Param_Spec))), Loc));
2295 if No (Expr_List) then
2296 Expr_List := New_List;
2299 Append_To (Expr_List,
2300 Make_Identifier (Loc,
2301 Chars => Chars (Defining_Identifier (Param_Spec))));
2303 -- The expressions in the attribute reference are not freeze
2304 -- points. Neither is the attribute as a whole, see below.
2306 Set_Must_Not_Freeze (Last (Expr_List));
2311 -- Immediate error if too many formals. Other mismatches in numbers
2312 -- of number of types of parameters are detected when we analyze the
2313 -- body of the subprogram that we construct.
2315 if Form_Num > 2 then
2316 Error_Msg_N ("too many formals for attribute", N);
2318 -- Error if the attribute reference has expressions that look
2319 -- like formal parameters.
2321 elsif Present (Expressions (Nam)) then
2322 Error_Msg_N ("illegal expressions in attribute reference", Nam);
2325 Aname = Name_Compose or else
2326 Aname = Name_Exponent or else
2327 Aname = Name_Leading_Part or else
2328 Aname = Name_Pos or else
2329 Aname = Name_Round or else
2330 Aname = Name_Scaling or else
2333 if Nkind (N) = N_Subprogram_Renaming_Declaration
2334 and then Present (Corresponding_Formal_Spec (N))
2337 ("generic actual cannot be attribute involving universal type",
2341 ("attribute involving a universal type cannot be renamed",
2346 -- AST_Entry is an odd case. It doesn't really make much sense to
2347 -- allow it to be renamed, but that's the DEC rule, so we have to
2348 -- do it right. The point is that the AST_Entry call should be made
2349 -- now, and what the function will return is the returned value.
2351 -- Note that there is no Expr_List in this case anyway
2353 if Aname = Name_AST_Entry then
2359 Ent := Make_Defining_Identifier (Loc, New_Internal_Name ('R'));
2362 Make_Object_Declaration (Loc,
2363 Defining_Identifier => Ent,
2364 Object_Definition =>
2365 New_Occurrence_Of (RTE (RE_AST_Handler), Loc),
2367 Constant_Present => True);
2369 Set_Assignment_OK (Decl, True);
2370 Insert_Action (N, Decl);
2371 Attr_Node := Make_Identifier (Loc, Chars (Ent));
2374 -- For all other attributes, we rewrite the attribute node to have
2375 -- a list of expressions corresponding to the subprogram formals.
2376 -- A renaming declaration is not a freeze point, and the analysis of
2377 -- the attribute reference should not freeze the type of the prefix.
2381 Make_Attribute_Reference (Loc,
2382 Prefix => Prefix (Nam),
2383 Attribute_Name => Aname,
2384 Expressions => Expr_List);
2386 Set_Must_Not_Freeze (Attr_Node);
2387 Set_Must_Not_Freeze (Prefix (Nam));
2390 -- Case of renaming a function
2392 if Nkind (Spec) = N_Function_Specification then
2393 if Is_Procedure_Attribute_Name (Aname) then
2394 Error_Msg_N ("attribute can only be renamed as procedure", Nam);
2398 Find_Type (Result_Definition (Spec));
2399 Rewrite (Result_Definition (Spec),
2401 Base_Type (Entity (Result_Definition (Spec))), Loc));
2404 Make_Subprogram_Body (Loc,
2405 Specification => Spec,
2406 Declarations => New_List,
2407 Handled_Statement_Sequence =>
2408 Make_Handled_Sequence_Of_Statements (Loc,
2409 Statements => New_List (
2410 Make_Simple_Return_Statement (Loc,
2411 Expression => Attr_Node))));
2413 -- Case of renaming a procedure
2416 if not Is_Procedure_Attribute_Name (Aname) then
2417 Error_Msg_N ("attribute can only be renamed as function", Nam);
2422 Make_Subprogram_Body (Loc,
2423 Specification => Spec,
2424 Declarations => New_List,
2425 Handled_Statement_Sequence =>
2426 Make_Handled_Sequence_Of_Statements (Loc,
2427 Statements => New_List (Attr_Node)));
2430 -- In case of tagged types we add the body of the generated function to
2431 -- the freezing actions of the type (because in the general case such
2432 -- type is still not frozen). We exclude from this processing generic
2433 -- formal subprograms found in instantiations and AST_Entry renamings.
2435 if not Present (Corresponding_Formal_Spec (N))
2436 and then Etype (Nam) /= RTE (RE_AST_Handler)
2439 P : constant Entity_Id := Prefix (Nam);
2444 if Is_Tagged_Type (Etype (P)) then
2445 Ensure_Freeze_Node (Etype (P));
2446 Append_Freeze_Action (Etype (P), Body_Node);
2448 Rewrite (N, Body_Node);
2450 Set_Etype (New_S, Base_Type (Etype (New_S)));
2454 -- Generic formal subprograms or AST_Handler renaming
2457 Rewrite (N, Body_Node);
2459 Set_Etype (New_S, Base_Type (Etype (New_S)));
2462 if Is_Compilation_Unit (New_S) then
2464 ("a library unit can only rename another library unit", N);
2467 -- We suppress elaboration warnings for the resulting entity, since
2468 -- clearly they are not needed, and more particularly, in the case
2469 -- of a generic formal subprogram, the resulting entity can appear
2470 -- after the instantiation itself, and thus look like a bogus case
2471 -- of access before elaboration.
2473 Set_Suppress_Elaboration_Warnings (New_S);
2475 end Attribute_Renaming;
2477 ----------------------
2478 -- Chain_Use_Clause --
2479 ----------------------
2481 procedure Chain_Use_Clause (N : Node_Id) is
2483 Level : Int := Scope_Stack.Last;
2486 if not Is_Compilation_Unit (Current_Scope)
2487 or else not Is_Child_Unit (Current_Scope)
2489 null; -- Common case
2491 elsif Defining_Entity (Parent (N)) = Current_Scope then
2492 null; -- Common case for compilation unit
2495 -- If declaration appears in some other scope, it must be in some
2496 -- parent unit when compiling a child.
2498 Pack := Defining_Entity (Parent (N));
2499 if not In_Open_Scopes (Pack) then
2500 null; -- default as well
2503 -- Find entry for parent unit in scope stack
2505 while Scope_Stack.Table (Level).Entity /= Pack loop
2511 Set_Next_Use_Clause (N,
2512 Scope_Stack.Table (Level).First_Use_Clause);
2513 Scope_Stack.Table (Level).First_Use_Clause := N;
2514 end Chain_Use_Clause;
2516 ---------------------------
2517 -- Check_Frozen_Renaming --
2518 ---------------------------
2520 procedure Check_Frozen_Renaming (N : Node_Id; Subp : Entity_Id) is
2526 and then not Has_Completion (Subp)
2530 (Parent (Declaration_Node (Subp)), Defining_Entity (N));
2532 if Is_Entity_Name (Name (N)) then
2533 Old_S := Entity (Name (N));
2535 if not Is_Frozen (Old_S)
2536 and then Operating_Mode /= Check_Semantics
2538 Append_Freeze_Action (Old_S, B_Node);
2540 Insert_After (N, B_Node);
2544 if Is_Intrinsic_Subprogram (Old_S)
2545 and then not In_Instance
2548 ("subprogram used in renaming_as_body cannot be intrinsic",
2553 Insert_After (N, B_Node);
2557 end Check_Frozen_Renaming;
2559 -----------------------------------
2560 -- Check_In_Previous_With_Clause --
2561 -----------------------------------
2563 procedure Check_In_Previous_With_Clause
2567 Pack : constant Entity_Id := Entity (Original_Node (Nam));
2572 Item := First (Context_Items (Parent (N)));
2574 while Present (Item)
2577 if Nkind (Item) = N_With_Clause
2579 -- Protect the frontend against previous critical errors
2581 and then Nkind (Name (Item)) /= N_Selected_Component
2582 and then Entity (Name (Item)) = Pack
2586 -- Find root library unit in with_clause
2588 while Nkind (Par) = N_Expanded_Name loop
2589 Par := Prefix (Par);
2592 if Is_Child_Unit (Entity (Original_Node (Par))) then
2594 ("& is not directly visible", Par, Entity (Par));
2603 -- On exit, package is not mentioned in a previous with_clause.
2604 -- Check if its prefix is.
2606 if Nkind (Nam) = N_Expanded_Name then
2607 Check_In_Previous_With_Clause (N, Prefix (Nam));
2609 elsif Pack /= Any_Id then
2610 Error_Msg_NE ("& is not visible", Nam, Pack);
2612 end Check_In_Previous_With_Clause;
2614 ---------------------------------
2615 -- Check_Library_Unit_Renaming --
2616 ---------------------------------
2618 procedure Check_Library_Unit_Renaming (N : Node_Id; Old_E : Entity_Id) is
2622 if Nkind (Parent (N)) /= N_Compilation_Unit then
2625 -- Check for library unit. Note that we used to check for the scope
2626 -- being Standard here, but that was wrong for Standard itself.
2628 elsif not Is_Compilation_Unit (Old_E)
2629 and then not Is_Child_Unit (Old_E)
2631 Error_Msg_N ("renamed unit must be a library unit", Name (N));
2633 -- Entities defined in Standard (operators and boolean literals) cannot
2634 -- be renamed as library units.
2636 elsif Scope (Old_E) = Standard_Standard
2637 and then Sloc (Old_E) = Standard_Location
2639 Error_Msg_N ("renamed unit must be a library unit", Name (N));
2641 elsif Present (Parent_Spec (N))
2642 and then Nkind (Unit (Parent_Spec (N))) = N_Generic_Package_Declaration
2643 and then not Is_Child_Unit (Old_E)
2646 ("renamed unit must be a child unit of generic parent", Name (N));
2648 elsif Nkind (N) in N_Generic_Renaming_Declaration
2649 and then Nkind (Name (N)) = N_Expanded_Name
2650 and then Is_Generic_Instance (Entity (Prefix (Name (N))))
2651 and then Is_Generic_Unit (Old_E)
2654 ("renamed generic unit must be a library unit", Name (N));
2656 elsif Ekind (Old_E) = E_Package
2657 or else Ekind (Old_E) = E_Generic_Package
2659 -- Inherit categorization flags
2661 New_E := Defining_Entity (N);
2662 Set_Is_Pure (New_E, Is_Pure (Old_E));
2663 Set_Is_Preelaborated (New_E, Is_Preelaborated (Old_E));
2664 Set_Is_Remote_Call_Interface (New_E,
2665 Is_Remote_Call_Interface (Old_E));
2666 Set_Is_Remote_Types (New_E, Is_Remote_Types (Old_E));
2667 Set_Is_Shared_Passive (New_E, Is_Shared_Passive (Old_E));
2669 end Check_Library_Unit_Renaming;
2675 procedure End_Scope is
2681 Id := First_Entity (Current_Scope);
2682 while Present (Id) loop
2683 -- An entity in the current scope is not necessarily the first one
2684 -- on its homonym chain. Find its predecessor if any,
2685 -- If it is an internal entity, it will not be in the visibility
2686 -- chain altogether, and there is nothing to unchain.
2688 if Id /= Current_Entity (Id) then
2689 Prev := Current_Entity (Id);
2690 while Present (Prev)
2691 and then Present (Homonym (Prev))
2692 and then Homonym (Prev) /= Id
2694 Prev := Homonym (Prev);
2697 -- Skip to end of loop if Id is not in the visibility chain
2699 if No (Prev) or else Homonym (Prev) /= Id then
2707 Set_Is_Immediately_Visible (Id, False);
2709 Outer := Homonym (Id);
2710 while Present (Outer) and then Scope (Outer) = Current_Scope loop
2711 Outer := Homonym (Outer);
2714 -- Reset homonym link of other entities, but do not modify link
2715 -- between entities in current scope, so that the back-end can have
2716 -- a proper count of local overloadings.
2719 Set_Name_Entity_Id (Chars (Id), Outer);
2721 elsif Scope (Prev) /= Scope (Id) then
2722 Set_Homonym (Prev, Outer);
2729 -- If the scope generated freeze actions, place them before the
2730 -- current declaration and analyze them. Type declarations and
2731 -- the bodies of initialization procedures can generate such nodes.
2732 -- We follow the parent chain until we reach a list node, which is
2733 -- the enclosing list of declarations. If the list appears within
2734 -- a protected definition, move freeze nodes outside the protected
2738 (Scope_Stack.Table (Scope_Stack.Last).Pending_Freeze_Actions)
2742 L : constant List_Id := Scope_Stack.Table
2743 (Scope_Stack.Last).Pending_Freeze_Actions;
2746 if Is_Itype (Current_Scope) then
2747 Decl := Associated_Node_For_Itype (Current_Scope);
2749 Decl := Parent (Current_Scope);
2754 while not (Is_List_Member (Decl))
2755 or else Nkind (Parent (Decl)) = N_Protected_Definition
2756 or else Nkind (Parent (Decl)) = N_Task_Definition
2758 Decl := Parent (Decl);
2761 Insert_List_Before_And_Analyze (Decl, L);
2770 ---------------------
2771 -- End_Use_Clauses --
2772 ---------------------
2774 procedure End_Use_Clauses (Clause : Node_Id) is
2778 -- Remove Use_Type clauses first, because they affect the
2779 -- visibility of operators in subsequent used packages.
2782 while Present (U) loop
2783 if Nkind (U) = N_Use_Type_Clause then
2787 Next_Use_Clause (U);
2791 while Present (U) loop
2792 if Nkind (U) = N_Use_Package_Clause then
2793 End_Use_Package (U);
2796 Next_Use_Clause (U);
2798 end End_Use_Clauses;
2800 ---------------------
2801 -- End_Use_Package --
2802 ---------------------
2804 procedure End_Use_Package (N : Node_Id) is
2805 Pack_Name : Node_Id;
2810 function Is_Primitive_Operator
2812 F : Entity_Id) return Boolean;
2813 -- Check whether Op is a primitive operator of a use-visible type
2815 ---------------------------
2816 -- Is_Primitive_Operator --
2817 ---------------------------
2819 function Is_Primitive_Operator
2821 F : Entity_Id) return Boolean
2823 T : constant Entity_Id := Etype (F);
2826 and then Scope (T) = Scope (Op);
2827 end Is_Primitive_Operator;
2829 -- Start of processing for End_Use_Package
2832 Pack_Name := First (Names (N));
2833 while Present (Pack_Name) loop
2834 Pack := Entity (Pack_Name);
2836 if Ekind (Pack) = E_Package then
2837 if In_Open_Scopes (Pack) then
2840 elsif not Redundant_Use (Pack_Name) then
2841 Set_In_Use (Pack, False);
2842 Set_Current_Use_Clause (Pack, Empty);
2844 Id := First_Entity (Pack);
2845 while Present (Id) loop
2847 -- Preserve use-visibility of operators that are primitive
2848 -- operators of a type that is use_visible through an active
2851 if Nkind (Id) = N_Defining_Operator_Symbol
2853 (Is_Primitive_Operator (Id, First_Formal (Id))
2855 (Present (Next_Formal (First_Formal (Id)))
2857 Is_Primitive_Operator
2858 (Id, Next_Formal (First_Formal (Id)))))
2863 Set_Is_Potentially_Use_Visible (Id, False);
2866 if Is_Private_Type (Id)
2867 and then Present (Full_View (Id))
2869 Set_Is_Potentially_Use_Visible (Full_View (Id), False);
2875 if Present (Renamed_Object (Pack)) then
2876 Set_In_Use (Renamed_Object (Pack), False);
2877 Set_Current_Use_Clause (Renamed_Object (Pack), Empty);
2880 if Chars (Pack) = Name_System
2881 and then Scope (Pack) = Standard_Standard
2882 and then Present_System_Aux
2884 Id := First_Entity (System_Aux_Id);
2885 while Present (Id) loop
2886 Set_Is_Potentially_Use_Visible (Id, False);
2888 if Is_Private_Type (Id)
2889 and then Present (Full_View (Id))
2891 Set_Is_Potentially_Use_Visible (Full_View (Id), False);
2897 Set_In_Use (System_Aux_Id, False);
2901 Set_Redundant_Use (Pack_Name, False);
2908 if Present (Hidden_By_Use_Clause (N)) then
2909 Elmt := First_Elmt (Hidden_By_Use_Clause (N));
2910 while Present (Elmt) loop
2911 Set_Is_Immediately_Visible (Node (Elmt));
2915 Set_Hidden_By_Use_Clause (N, No_Elist);
2917 end End_Use_Package;
2923 procedure End_Use_Type (N : Node_Id) is
2930 Id := First (Subtype_Marks (N));
2931 while Present (Id) loop
2933 -- A call to rtsfind may occur while analyzing a use_type clause,
2934 -- in which case the type marks are not resolved yet, and there is
2935 -- nothing to remove.
2937 if not Is_Entity_Name (Id)
2938 or else No (Entity (Id))
2946 or else From_With_Type (T)
2950 -- Note that the use_Type clause may mention a subtype of the type
2951 -- whose primitive operations have been made visible. Here as
2952 -- elsewhere, it is the base type that matters for visibility.
2954 elsif In_Open_Scopes (Scope (Base_Type (T))) then
2957 elsif not Redundant_Use (Id) then
2958 Set_In_Use (T, False);
2959 Set_In_Use (Base_Type (T), False);
2960 Op_List := Collect_Primitive_Operations (T);
2962 Elmt := First_Elmt (Op_List);
2963 while Present (Elmt) loop
2964 if Nkind (Node (Elmt)) = N_Defining_Operator_Symbol then
2965 Set_Is_Potentially_Use_Visible (Node (Elmt), False);
2977 ----------------------
2978 -- Find_Direct_Name --
2979 ----------------------
2981 procedure Find_Direct_Name (N : Node_Id) is
2986 Inst : Entity_Id := Empty;
2987 -- Enclosing instance, if any
2989 Homonyms : Entity_Id;
2990 -- Saves start of homonym chain
2992 Nvis_Entity : Boolean;
2993 -- Set True to indicate that at there is at least one entity on the
2994 -- homonym chain which, while not visible, is visible enough from the
2995 -- user point of view to warrant an error message of "not visible"
2996 -- rather than undefined.
2998 Nvis_Is_Private_Subprg : Boolean := False;
2999 -- Ada 2005 (AI-262): Set True to indicate that a form of Beaujolais
3000 -- effect concerning library subprograms has been detected. Used to
3001 -- generate the precise error message.
3003 function From_Actual_Package (E : Entity_Id) return Boolean;
3004 -- Returns true if the entity is declared in a package that is
3005 -- an actual for a formal package of the current instance. Such an
3006 -- entity requires special handling because it may be use-visible
3007 -- but hides directly visible entities defined outside the instance.
3009 function Known_But_Invisible (E : Entity_Id) return Boolean;
3010 -- This function determines whether the entity E (which is not
3011 -- visible) can reasonably be considered to be known to the writer
3012 -- of the reference. This is a heuristic test, used only for the
3013 -- purposes of figuring out whether we prefer to complain that an
3014 -- entity is undefined or invisible (and identify the declaration
3015 -- of the invisible entity in the latter case). The point here is
3016 -- that we don't want to complain that something is invisible and
3017 -- then point to something entirely mysterious to the writer.
3019 procedure Nvis_Messages;
3020 -- Called if there are no visible entries for N, but there is at least
3021 -- one non-directly visible, or hidden declaration. This procedure
3022 -- outputs an appropriate set of error messages.
3024 procedure Undefined (Nvis : Boolean);
3025 -- This function is called if the current node has no corresponding
3026 -- visible entity or entities. The value set in Msg indicates whether
3027 -- an error message was generated (multiple error messages for the
3028 -- same variable are generally suppressed, see body for details).
3029 -- Msg is True if an error message was generated, False if not. This
3030 -- value is used by the caller to determine whether or not to output
3031 -- additional messages where appropriate. The parameter is set False
3032 -- to get the message "X is undefined", and True to get the message
3033 -- "X is not visible".
3035 -------------------------
3036 -- From_Actual_Package --
3037 -------------------------
3039 function From_Actual_Package (E : Entity_Id) return Boolean is
3040 Scop : constant Entity_Id := Scope (E);
3044 if not In_Instance then
3047 Inst := Current_Scope;
3048 while Present (Inst)
3049 and then Ekind (Inst) /= E_Package
3050 and then not Is_Generic_Instance (Inst)
3052 Inst := Scope (Inst);
3059 Act := First_Entity (Inst);
3060 while Present (Act) loop
3061 if Ekind (Act) = E_Package then
3063 -- Check for end of actuals list
3065 if Renamed_Object (Act) = Inst then
3068 elsif Present (Associated_Formal_Package (Act))
3069 and then Renamed_Object (Act) = Scop
3071 -- Entity comes from (instance of) formal package
3086 end From_Actual_Package;
3088 -------------------------
3089 -- Known_But_Invisible --
3090 -------------------------
3092 function Known_But_Invisible (E : Entity_Id) return Boolean is
3093 Fname : File_Name_Type;
3096 -- Entities in Standard are always considered to be known
3098 if Sloc (E) <= Standard_Location then
3101 -- An entity that does not come from source is always considered
3102 -- to be unknown, since it is an artifact of code expansion.
3104 elsif not Comes_From_Source (E) then
3107 -- In gnat internal mode, we consider all entities known
3109 elsif GNAT_Mode then
3113 -- Here we have an entity that is not from package Standard, and
3114 -- which comes from Source. See if it comes from an internal file.
3116 Fname := Unit_File_Name (Get_Source_Unit (E));
3118 -- Case of from internal file
3120 if Is_Internal_File_Name (Fname) then
3122 -- Private part entities in internal files are never considered
3123 -- to be known to the writer of normal application code.
3125 if Is_Hidden (E) then
3129 -- Entities from System packages other than System and
3130 -- System.Storage_Elements are not considered to be known.
3131 -- System.Auxxxx files are also considered known to the user.
3133 -- Should refine this at some point to generally distinguish
3134 -- between known and unknown internal files ???
3136 Get_Name_String (Fname);
3141 Name_Buffer (1 .. 2) /= "s-"
3143 Name_Buffer (3 .. 8) = "stoele"
3145 Name_Buffer (3 .. 5) = "aux";
3147 -- If not an internal file, then entity is definitely known,
3148 -- even if it is in a private part (the message generated will
3149 -- note that it is in a private part)
3154 end Known_But_Invisible;
3160 procedure Nvis_Messages is
3161 Comp_Unit : Node_Id;
3163 Hidden : Boolean := False;
3167 -- Ada 2005 (AI-262): Generate a precise error concerning the
3168 -- Beaujolais effect that was previously detected
3170 if Nvis_Is_Private_Subprg then
3172 pragma Assert (Nkind (E2) = N_Defining_Identifier
3173 and then Ekind (E2) = E_Function
3174 and then Scope (E2) = Standard_Standard
3175 and then Has_Private_With (E2));
3177 -- Find the sloc corresponding to the private with'ed unit
3179 Comp_Unit := Cunit (Current_Sem_Unit);
3180 Error_Msg_Sloc := No_Location;
3182 Item := First (Context_Items (Comp_Unit));
3183 while Present (Item) loop
3184 if Nkind (Item) = N_With_Clause
3185 and then Private_Present (Item)
3186 and then Entity (Name (Item)) = E2
3188 Error_Msg_Sloc := Sloc (Item);
3195 pragma Assert (Error_Msg_Sloc /= No_Location);
3197 Error_Msg_N ("(Ada 2005): hidden by private with clause #", N);
3201 Undefined (Nvis => True);
3205 -- First loop does hidden declarations
3208 while Present (Ent) loop
3209 if Is_Potentially_Use_Visible (Ent) then
3211 Error_Msg_N ("multiple use clauses cause hiding!", N);
3215 Error_Msg_Sloc := Sloc (Ent);
3216 Error_Msg_N ("hidden declaration#!", N);
3219 Ent := Homonym (Ent);
3222 -- If we found hidden declarations, then that's enough, don't
3223 -- bother looking for non-visible declarations as well.
3229 -- Second loop does non-directly visible declarations
3232 while Present (Ent) loop
3233 if not Is_Potentially_Use_Visible (Ent) then
3235 -- Do not bother the user with unknown entities
3237 if not Known_But_Invisible (Ent) then
3241 Error_Msg_Sloc := Sloc (Ent);
3243 -- Output message noting that there is a non-visible
3244 -- declaration, distinguishing the private part case.
3246 if Is_Hidden (Ent) then
3247 Error_Msg_N ("non-visible (private) declaration#!", N);
3249 Error_Msg_N ("non-visible declaration#!", N);
3251 if Is_Compilation_Unit (Ent)
3253 Nkind (Parent (Parent (N))) = N_Use_Package_Clause
3255 Error_Msg_Qual_Level := 99;
3256 Error_Msg_NE ("\\missing `WITH &;`", N, Ent);
3257 Error_Msg_Qual_Level := 0;
3261 -- Set entity and its containing package as referenced. We
3262 -- can't be sure of this, but this seems a better choice
3263 -- to avoid unused entity messages.
3265 if Comes_From_Source (Ent) then
3266 Set_Referenced (Ent);
3267 Set_Referenced (Cunit_Entity (Get_Source_Unit (Ent)));
3272 Ent := Homonym (Ent);
3281 procedure Undefined (Nvis : Boolean) is
3282 Emsg : Error_Msg_Id;
3285 -- We should never find an undefined internal name. If we do, then
3286 -- see if we have previous errors. If so, ignore on the grounds that
3287 -- it is probably a cascaded message (e.g. a block label from a badly
3288 -- formed block). If no previous errors, then we have a real internal
3289 -- error of some kind so raise an exception.
3291 if Is_Internal_Name (Chars (N)) then
3292 if Total_Errors_Detected /= 0 then
3295 raise Program_Error;
3299 -- A very specialized error check, if the undefined variable is
3300 -- a case tag, and the case type is an enumeration type, check
3301 -- for a possible misspelling, and if so, modify the identifier
3303 -- Named aggregate should also be handled similarly ???
3305 if Nkind (N) = N_Identifier
3306 and then Nkind (Parent (N)) = N_Case_Statement_Alternative
3308 Get_Name_String (Chars (N));
3311 Case_Str : constant String := Name_Buffer (1 .. Name_Len);
3312 Case_Stm : constant Node_Id := Parent (Parent (N));
3313 Case_Typ : constant Entity_Id := Etype (Expression (Case_Stm));
3314 Case_Rtp : constant Entity_Id := Root_Type (Case_Typ);
3319 if Is_Enumeration_Type (Case_Typ)
3320 and then Case_Rtp /= Standard_Character
3321 and then Case_Rtp /= Standard_Wide_Character
3322 and then Case_Rtp /= Standard_Wide_Wide_Character
3324 Lit := First_Literal (Case_Typ);
3325 Get_Name_String (Chars (Lit));
3327 if Chars (Lit) /= Chars (N)
3328 and then Is_Bad_Spelling_Of
3329 (Case_Str, Name_Buffer (1 .. Name_Len))
3331 Error_Msg_Node_2 := Lit;
3333 ("& is undefined, assume misspelling of &", N);
3334 Rewrite (N, New_Occurrence_Of (Lit, Sloc (N)));
3338 Lit := Next_Literal (Lit);
3343 -- Normal processing
3345 Set_Entity (N, Any_Id);
3346 Set_Etype (N, Any_Type);
3348 -- We use the table Urefs to keep track of entities for which we
3349 -- have issued errors for undefined references. Multiple errors
3350 -- for a single name are normally suppressed, however we modify
3351 -- the error message to alert the programmer to this effect.
3353 for J in Urefs.First .. Urefs.Last loop
3354 if Chars (N) = Chars (Urefs.Table (J).Node) then
3355 if Urefs.Table (J).Err /= No_Error_Msg
3356 and then Sloc (N) /= Urefs.Table (J).Loc
3358 Error_Msg_Node_1 := Urefs.Table (J).Node;
3360 if Urefs.Table (J).Nvis then
3361 Change_Error_Text (Urefs.Table (J).Err,
3362 "& is not visible (more references follow)");
3364 Change_Error_Text (Urefs.Table (J).Err,
3365 "& is undefined (more references follow)");
3368 Urefs.Table (J).Err := No_Error_Msg;
3371 -- Although we will set Msg False, and thus suppress the
3372 -- message, we also set Error_Posted True, to avoid any
3373 -- cascaded messages resulting from the undefined reference.
3376 Set_Error_Posted (N, True);
3381 -- If entry not found, this is first undefined occurrence
3384 Error_Msg_N ("& is not visible!", N);
3388 Error_Msg_N ("& is undefined!", N);
3391 -- A very bizarre special check, if the undefined identifier
3392 -- is put or put_line, then add a special error message (since
3393 -- this is a very common error for beginners to make).
3395 if Chars (N) = Name_Put or else Chars (N) = Name_Put_Line then
3397 ("\\possible missing `WITH Ada.Text_'I'O; " &
3398 "USE Ada.Text_'I'O`!", N);
3400 -- Another special check if N is the prefix of a selected
3401 -- component which is a known unit, add message complaining
3402 -- about missing with for this unit.
3404 elsif Nkind (Parent (N)) = N_Selected_Component
3405 and then N = Prefix (Parent (N))
3406 and then Is_Known_Unit (Parent (N))
3408 Error_Msg_Node_2 := Selector_Name (Parent (N));
3409 Error_Msg_N ("\\missing `WITH &.&;`", Prefix (Parent (N)));
3412 -- Now check for possible misspellings
3414 Get_Name_String (Chars (N));
3418 Ematch : Entity_Id := Empty;
3420 Last_Name_Id : constant Name_Id :=
3421 Name_Id (Nat (First_Name_Id) +
3422 Name_Entries_Count - 1);
3424 S : constant String (1 .. Name_Len) :=
3425 Name_Buffer (1 .. Name_Len);
3428 for N in First_Name_Id .. Last_Name_Id loop
3429 E := Get_Name_Entity_Id (N);
3432 and then (Is_Immediately_Visible (E)
3434 Is_Potentially_Use_Visible (E))
3436 Get_Name_String (N);
3438 if Is_Bad_Spelling_Of
3439 (S, Name_Buffer (1 .. Name_Len))
3447 if Present (Ematch) then
3448 Error_Msg_NE ("\possible misspelling of&", N, Ematch);
3453 -- Make entry in undefined references table unless the full errors
3454 -- switch is set, in which case by refraining from generating the
3455 -- table entry, we guarantee that we get an error message for every
3456 -- undefined reference.
3458 if not All_Errors_Mode then
3469 -- Start of processing for Find_Direct_Name
3472 -- If the entity pointer is already set, this is an internal node, or
3473 -- a node that is analyzed more than once, after a tree modification.
3474 -- In such a case there is no resolution to perform, just set the type.
3476 if Present (Entity (N)) then
3477 if Is_Type (Entity (N)) then
3478 Set_Etype (N, Entity (N));
3482 Entyp : constant Entity_Id := Etype (Entity (N));
3485 -- One special case here. If the Etype field is already set,
3486 -- and references the packed array type corresponding to the
3487 -- etype of the referenced entity, then leave it alone. This
3488 -- happens for trees generated from Exp_Pakd, where expressions
3489 -- can be deliberately "mis-typed" to the packed array type.
3491 if Is_Array_Type (Entyp)
3492 and then Is_Packed (Entyp)
3493 and then Present (Etype (N))
3494 and then Etype (N) = Packed_Array_Type (Entyp)
3498 -- If not that special case, then just reset the Etype
3501 Set_Etype (N, Etype (Entity (N)));
3509 -- Here if Entity pointer was not set, we need full visibility analysis
3510 -- First we generate debugging output if the debug E flag is set.
3512 if Debug_Flag_E then
3513 Write_Str ("Looking for ");
3514 Write_Name (Chars (N));
3518 Homonyms := Current_Entity (N);
3519 Nvis_Entity := False;
3522 while Present (E) loop
3524 -- If entity is immediately visible or potentially use
3525 -- visible, then process the entity and we are done.
3527 if Is_Immediately_Visible (E) then
3528 goto Immediately_Visible_Entity;
3530 elsif Is_Potentially_Use_Visible (E) then
3531 goto Potentially_Use_Visible_Entity;
3533 -- Note if a known but invisible entity encountered
3535 elsif Known_But_Invisible (E) then
3536 Nvis_Entity := True;
3539 -- Move to next entity in chain and continue search
3544 -- If no entries on homonym chain that were potentially visible,
3545 -- and no entities reasonably considered as non-visible, then
3546 -- we have a plain undefined reference, with no additional
3547 -- explanation required!
3549 if not Nvis_Entity then
3550 Undefined (Nvis => False);
3552 -- Otherwise there is at least one entry on the homonym chain that
3553 -- is reasonably considered as being known and non-visible.
3561 -- Processing for a potentially use visible entry found. We must search
3562 -- the rest of the homonym chain for two reasons. First, if there is a
3563 -- directly visible entry, then none of the potentially use-visible
3564 -- entities are directly visible (RM 8.4(10)). Second, we need to check
3565 -- for the case of multiple potentially use-visible entries hiding one
3566 -- another and as a result being non-directly visible (RM 8.4(11)).
3568 <<Potentially_Use_Visible_Entity>> declare
3569 Only_One_Visible : Boolean := True;
3570 All_Overloadable : Boolean := Is_Overloadable (E);
3574 while Present (E2) loop
3575 if Is_Immediately_Visible (E2) then
3577 -- If the use-visible entity comes from the actual for a
3578 -- formal package, it hides a directly visible entity from
3579 -- outside the instance.
3581 if From_Actual_Package (E)
3582 and then Scope_Depth (E2) < Scope_Depth (Inst)
3587 goto Immediately_Visible_Entity;
3590 elsif Is_Potentially_Use_Visible (E2) then
3591 Only_One_Visible := False;
3592 All_Overloadable := All_Overloadable and Is_Overloadable (E2);
3594 -- Ada 2005 (AI-262): Protect against a form of Beujolais effect
3595 -- that can occurr in private_with clauses. Example:
3598 -- private with B; package A is
3599 -- package C is function B return Integer;
3601 -- V1 : Integer := B;
3602 -- private function B return Integer;
3603 -- V2 : Integer := B;
3606 -- V1 resolves to A.B, but V2 resolves to library unit B
3608 elsif Ekind (E2) = E_Function
3609 and then Scope (E2) = Standard_Standard
3610 and then Has_Private_With (E2)
3612 Only_One_Visible := False;
3613 All_Overloadable := False;
3614 Nvis_Is_Private_Subprg := True;
3621 -- On falling through this loop, we have checked that there are no
3622 -- immediately visible entities. Only_One_Visible is set if exactly
3623 -- one potentially use visible entity exists. All_Overloadable is
3624 -- set if all the potentially use visible entities are overloadable.
3625 -- The condition for legality is that either there is one potentially
3626 -- use visible entity, or if there is more than one, then all of them
3627 -- are overloadable.
3629 if Only_One_Visible or All_Overloadable then
3632 -- If there is more than one potentially use-visible entity and at
3633 -- least one of them non-overloadable, we have an error (RM 8.4(11).
3634 -- Note that E points to the first such entity on the homonym list.
3635 -- Special case: if one of the entities is declared in an actual
3636 -- package, it was visible in the generic, and takes precedence over
3637 -- other entities that are potentially use-visible. Same if it is
3638 -- declared in a local instantiation of the current instance.
3643 -- Find current instance
3645 Inst := Current_Scope;
3646 while Present (Inst)
3647 and then Inst /= Standard_Standard
3649 if Is_Generic_Instance (Inst) then
3653 Inst := Scope (Inst);
3657 while Present (E2) loop
3658 if From_Actual_Package (E2)
3660 (Is_Generic_Instance (Scope (E2))
3661 and then Scope_Depth (Scope (E2)) > Scope_Depth (Inst))
3674 Is_Predefined_File_Name (Unit_File_Name (Current_Sem_Unit))
3676 -- A use-clause in the body of a system file creates conflict
3677 -- with some entity in a user scope, while rtsfind is active.
3678 -- Keep only the entity coming from another predefined unit.
3681 while Present (E2) loop
3682 if Is_Predefined_File_Name
3683 (Unit_File_Name (Get_Source_Unit (Sloc (E2))))
3692 -- Entity must exist because predefined unit is correct
3694 raise Program_Error;
3703 -- Come here with E set to the first immediately visible entity on
3704 -- the homonym chain. This is the one we want unless there is another
3705 -- immediately visible entity further on in the chain for a more
3706 -- inner scope (RM 8.3(8)).
3708 <<Immediately_Visible_Entity>> declare
3713 -- Find scope level of initial entity. When compiling through
3714 -- Rtsfind, the previous context is not completely invisible, and
3715 -- an outer entity may appear on the chain, whose scope is below
3716 -- the entry for Standard that delimits the current scope stack.
3717 -- Indicate that the level for this spurious entry is outside of
3718 -- the current scope stack.
3720 Level := Scope_Stack.Last;
3722 Scop := Scope_Stack.Table (Level).Entity;
3723 exit when Scop = Scope (E);
3725 exit when Scop = Standard_Standard;
3728 -- Now search remainder of homonym chain for more inner entry
3729 -- If the entity is Standard itself, it has no scope, and we
3730 -- compare it with the stack entry directly.
3733 while Present (E2) loop
3734 if Is_Immediately_Visible (E2) then
3736 -- If a generic package contains a local declaration that
3737 -- has the same name as the generic, there may be a visibility
3738 -- conflict in an instance, where the local declaration must
3739 -- also hide the name of the corresponding package renaming.
3740 -- We check explicitly for a package declared by a renaming,
3741 -- whose renamed entity is an instance that is on the scope
3742 -- stack, and that contains a homonym in the same scope. Once
3743 -- we have found it, we know that the package renaming is not
3744 -- immediately visible, and that the identifier denotes the
3745 -- other entity (and its homonyms if overloaded).
3747 if Scope (E) = Scope (E2)
3748 and then Ekind (E) = E_Package
3749 and then Present (Renamed_Object (E))
3750 and then Is_Generic_Instance (Renamed_Object (E))
3751 and then In_Open_Scopes (Renamed_Object (E))
3752 and then Comes_From_Source (N)
3754 Set_Is_Immediately_Visible (E, False);
3758 for J in Level + 1 .. Scope_Stack.Last loop
3759 if Scope_Stack.Table (J).Entity = Scope (E2)
3760 or else Scope_Stack.Table (J).Entity = E2
3773 -- At the end of that loop, E is the innermost immediately
3774 -- visible entity, so we are all set.
3777 -- Come here with entity found, and stored in E
3781 if Comes_From_Source (N)
3782 and then Is_Remote_Access_To_Subprogram_Type (E)
3783 and then Expander_Active
3784 and then Get_PCS_Name /= Name_No_DSA
3787 New_Occurrence_Of (Equivalent_Type (E), Sloc (N)));
3792 -- Why no Style_Check here???
3797 Set_Etype (N, Get_Full_View (Etype (E)));
3800 if Debug_Flag_E then
3801 Write_Str (" found ");
3802 Write_Entity_Info (E, " ");
3805 -- If the Ekind of the entity is Void, it means that all homonyms
3806 -- are hidden from all visibility (RM 8.3(5,14-20)). However, this
3807 -- test is skipped if the current scope is a record and the name is
3808 -- a pragma argument expression (case of Atomic and Volatile pragmas
3809 -- and possibly other similar pragmas added later, which are allowed
3810 -- to reference components in the current record).
3812 if Ekind (E) = E_Void
3814 (not Is_Record_Type (Current_Scope)
3815 or else Nkind (Parent (N)) /= N_Pragma_Argument_Association)
3817 Premature_Usage (N);
3819 -- If the entity is overloadable, collect all interpretations of the
3820 -- name for subsequent overload resolution. We optimize a bit here to
3821 -- do this only if we have an overloadable entity that is not on its
3822 -- own on the homonym chain.
3824 elsif Is_Overloadable (E)
3825 and then (Present (Homonym (E)) or else Current_Entity (N) /= E)
3827 Collect_Interps (N);
3829 -- If no homonyms were visible, the entity is unambiguous
3831 if not Is_Overloaded (N) then
3832 Generate_Reference (E, N);
3835 -- Case of non-overloadable entity, set the entity providing that
3836 -- we do not have the case of a discriminant reference within a
3837 -- default expression. Such references are replaced with the
3838 -- corresponding discriminal, which is the formal corresponding to
3839 -- to the discriminant in the initialization procedure.
3842 -- Entity is unambiguous, indicate that it is referenced here. One
3843 -- slightly odd case is that we do not want to set the Referenced
3844 -- flag if the entity is a label, and the identifier is the label
3845 -- in the source, since this is not a reference from the point of
3848 if Nkind (Parent (N)) = N_Label then
3850 R : constant Boolean := Referenced (E);
3853 Generate_Reference (E, N);
3854 Set_Referenced (E, R);
3857 -- Normal case, not a label: generate reference
3859 -- ??? It is too early to generate a reference here even if
3860 -- the entity is unambiguous, because the tree is not
3861 -- sufficiently typed at this point for Generate_Reference to
3862 -- determine whether this reference modifies the denoted object
3863 -- (because implicit derefences cannot be identified prior to
3864 -- full type resolution).
3867 Generate_Reference (E, N);
3868 Check_Nested_Access (E);
3871 -- Set Entity, with style check if need be. For a discriminant
3872 -- reference, replace by the corresponding discriminal, i.e. the
3873 -- parameter of the initialization procedure that corresponds to
3874 -- the discriminant. If this replacement is being performed, there
3875 -- is no style check to perform.
3877 -- This replacement must not be done if we are currently
3878 -- processing a generic spec or body, because the discriminal
3879 -- has not been not generated in this case.
3881 if not In_Default_Expression
3882 or else Ekind (E) /= E_Discriminant
3883 or else Inside_A_Generic
3885 Set_Entity_With_Style_Check (N, E);
3887 -- The replacement is not done either for a task discriminant that
3888 -- appears in a default expression of an entry parameter. See
3889 -- Expand_Discriminant in exp_ch2 for details on their handling.
3891 elsif Is_Concurrent_Type (Scope (E)) then
3898 and then Nkind (P) /= N_Parameter_Specification
3899 and then Nkind (P) /= N_Component_Declaration
3905 and then Nkind (P) = N_Parameter_Specification
3909 Set_Entity (N, Discriminal (E));
3913 -- Otherwise, this is a discriminant in a context in which
3914 -- it is a reference to the corresponding parameter of the
3915 -- init proc for the enclosing type.
3918 Set_Entity (N, Discriminal (E));
3922 end Find_Direct_Name;
3924 ------------------------
3925 -- Find_Expanded_Name --
3926 ------------------------
3928 -- This routine searches the homonym chain of the entity until it finds
3929 -- an entity declared in the scope denoted by the prefix. If the entity
3930 -- is private, it may nevertheless be immediately visible, if we are in
3931 -- the scope of its declaration.
3933 procedure Find_Expanded_Name (N : Node_Id) is
3934 Selector : constant Node_Id := Selector_Name (N);
3935 Candidate : Entity_Id := Empty;
3941 P_Name := Entity (Prefix (N));
3944 -- If the prefix is a renamed package, look for the entity
3945 -- in the original package.
3947 if Ekind (P_Name) = E_Package
3948 and then Present (Renamed_Object (P_Name))
3950 P_Name := Renamed_Object (P_Name);
3952 -- Rewrite node with entity field pointing to renamed object
3954 Rewrite (Prefix (N), New_Copy (Prefix (N)));
3955 Set_Entity (Prefix (N), P_Name);
3957 -- If the prefix is an object of a concurrent type, look for
3958 -- the entity in the associated task or protected type.
3960 elsif Is_Concurrent_Type (Etype (P_Name)) then
3961 P_Name := Etype (P_Name);
3964 Id := Current_Entity (Selector);
3967 Is_New_Candidate : Boolean;
3970 while Present (Id) loop
3971 if Scope (Id) = P_Name then
3973 Is_New_Candidate := True;
3975 -- Ada 2005 (AI-217): Handle shadow entities associated with types
3976 -- declared in limited-withed nested packages. We don't need to
3977 -- handle E_Incomplete_Subtype entities because the entities in
3978 -- the limited view are always E_Incomplete_Type entities (see
3979 -- Build_Limited_Views). Regarding the expression used to evaluate
3980 -- the scope, it is important to note that the limited view also
3981 -- has shadow entities associated nested packages. For this reason
3982 -- the correct scope of the entity is the scope of the real entity
3983 -- The non-limited view may itself be incomplete, in which case
3984 -- get the full view if available.
3986 elsif From_With_Type (Id)
3987 and then Is_Type (Id)
3988 and then Ekind (Id) = E_Incomplete_Type
3989 and then Present (Non_Limited_View (Id))
3990 and then Scope (Non_Limited_View (Id)) = P_Name
3992 Candidate := Get_Full_View (Non_Limited_View (Id));
3993 Is_New_Candidate := True;
3996 Is_New_Candidate := False;
3999 if Is_New_Candidate then
4000 if Is_Child_Unit (Id) then
4001 exit when Is_Visible_Child_Unit (Id)
4002 or else Is_Immediately_Visible (Id);
4005 exit when not Is_Hidden (Id)
4006 or else Is_Immediately_Visible (Id);
4015 and then (Ekind (P_Name) = E_Procedure
4017 Ekind (P_Name) = E_Function)
4018 and then Is_Generic_Instance (P_Name)
4020 -- Expanded name denotes entity in (instance of) generic subprogram.
4021 -- The entity may be in the subprogram instance, or may denote one of
4022 -- the formals, which is declared in the enclosing wrapper package.
4024 P_Name := Scope (P_Name);
4026 Id := Current_Entity (Selector);
4027 while Present (Id) loop
4028 exit when Scope (Id) = P_Name;
4033 if No (Id) or else Chars (Id) /= Chars (Selector) then
4034 Set_Etype (N, Any_Type);
4036 -- If we are looking for an entity defined in System, try to
4037 -- find it in the child package that may have been provided as
4038 -- an extension to System. The Extend_System pragma will have
4039 -- supplied the name of the extension, which may have to be loaded.
4041 if Chars (P_Name) = Name_System
4042 and then Scope (P_Name) = Standard_Standard
4043 and then Present (System_Extend_Unit)
4044 and then Present_System_Aux (N)
4046 Set_Entity (Prefix (N), System_Aux_Id);
4047 Find_Expanded_Name (N);
4050 elsif Nkind (Selector) = N_Operator_Symbol
4051 and then Has_Implicit_Operator (N)
4053 -- There is an implicit instance of the predefined operator in
4054 -- the given scope. The operator entity is defined in Standard.
4055 -- Has_Implicit_Operator makes the node into an Expanded_Name.
4059 elsif Nkind (Selector) = N_Character_Literal
4060 and then Has_Implicit_Character_Literal (N)
4062 -- If there is no literal defined in the scope denoted by the
4063 -- prefix, the literal may belong to (a type derived from)
4064 -- Standard_Character, for which we have no explicit literals.
4069 -- If the prefix is a single concurrent object, use its
4070 -- name in the error message, rather than that of the
4073 if Is_Concurrent_Type (P_Name)
4074 and then Is_Internal_Name (Chars (P_Name))
4076 Error_Msg_Node_2 := Entity (Prefix (N));
4078 Error_Msg_Node_2 := P_Name;
4081 if P_Name = System_Aux_Id then
4082 P_Name := Scope (P_Name);
4083 Set_Entity (Prefix (N), P_Name);
4086 if Present (Candidate) then
4088 -- If we know that the unit is a child unit we can give a more
4089 -- accurate error message.
4091 if Is_Child_Unit (Candidate) then
4093 -- If the candidate is a private child unit and we are in
4094 -- the visible part of a public unit, specialize the error
4095 -- message. There might be a private with_clause for it,
4096 -- but it is not currently active.
4098 if Is_Private_Descendant (Candidate)
4099 and then Ekind (Current_Scope) = E_Package
4100 and then not In_Private_Part (Current_Scope)
4101 and then not Is_Private_Descendant (Current_Scope)
4103 Error_Msg_N ("private child unit& is not visible here",
4106 -- Normal case where we have a missing with for a child unit
4109 Error_Msg_Qual_Level := 99;
4110 Error_Msg_NE ("missing `WITH &;`", Selector, Candidate);
4111 Error_Msg_Qual_Level := 0;
4114 -- Here we don't know that this is a child unit
4117 Error_Msg_NE ("& is not a visible entity of&", N, Selector);
4121 -- Within the instantiation of a child unit, the prefix may
4122 -- denote the parent instance, but the selector has the name
4123 -- of the original child. Find whether we are within the
4124 -- corresponding instance, and get the proper entity, which
4125 -- can only be an enclosing scope.
4128 and then In_Open_Scopes (P_Name)
4129 and then Is_Generic_Instance (P_Name)
4132 S : Entity_Id := Current_Scope;
4136 for J in reverse 0 .. Scope_Stack.Last loop
4137 S := Scope_Stack.Table (J).Entity;
4139 exit when S = Standard_Standard;
4141 if Ekind (S) = E_Function
4142 or else Ekind (S) = E_Package
4143 or else Ekind (S) = E_Procedure
4145 P := Generic_Parent (Specification
4146 (Unit_Declaration_Node (S)));
4149 and then Chars (Scope (P)) = Chars (O_Name)
4150 and then Chars (P) = Chars (Selector)
4161 -- If this is a selection from Ada, System or Interfaces, then
4162 -- we assume a missing with for the corresponding package.
4164 if Is_Known_Unit (N) then
4165 if not Error_Posted (N) then
4166 Error_Msg_Node_2 := Selector;
4167 Error_Msg_N ("missing `WITH &.&;`", Prefix (N));
4170 -- If this is a selection from a dummy package, then suppress
4171 -- the error message, of course the entity is missing if the
4172 -- package is missing!
4174 elsif Sloc (Error_Msg_Node_2) = No_Location then
4177 -- Here we have the case of an undefined component
4180 Error_Msg_NE ("& not declared in&", N, Selector);
4182 -- Check for misspelling of some entity in prefix
4184 Id := First_Entity (P_Name);
4185 Get_Name_String (Chars (Selector));
4188 S : constant String (1 .. Name_Len) :=
4189 Name_Buffer (1 .. Name_Len);
4191 while Present (Id) loop
4192 Get_Name_String (Chars (Id));
4193 if Is_Bad_Spelling_Of
4194 (Name_Buffer (1 .. Name_Len), S)
4195 and then not Is_Internal_Name (Chars (Id))
4198 ("possible misspelling of&", Selector, Id);
4206 -- Specialize the message if this may be an instantiation
4207 -- of a child unit that was not mentioned in the context.
4209 if Nkind (Parent (N)) = N_Package_Instantiation
4210 and then Is_Generic_Instance (Entity (Prefix (N)))
4211 and then Is_Compilation_Unit
4212 (Generic_Parent (Parent (Entity (Prefix (N)))))
4214 Error_Msg_Node_2 := Selector;
4215 Error_Msg_N ("\missing `WITH &.&;`", Prefix (N));
4225 if Comes_From_Source (N)
4226 and then Is_Remote_Access_To_Subprogram_Type (Id)
4227 and then Present (Equivalent_Type (Id))
4229 -- If we are not actually generating distribution code (i.e. the
4230 -- current PCS is the dummy non-distributed version), then the
4231 -- Equivalent_Type will be missing, and Id should be treated as
4232 -- a regular access-to-subprogram type.
4234 Id := Equivalent_Type (Id);
4235 Set_Chars (Selector, Chars (Id));
4238 -- Ada 2005 (AI-50217): Check usage of entities in limited withed units
4240 if Ekind (P_Name) = E_Package
4241 and then From_With_Type (P_Name)
4243 if From_With_Type (Id)
4244 or else Is_Type (Id)
4245 or else Ekind (Id) = E_Package
4250 ("limited withed package can only be used to access "
4251 & " incomplete types",
4256 if Is_Task_Type (P_Name)
4257 and then ((Ekind (Id) = E_Entry
4258 and then Nkind (Parent (N)) /= N_Attribute_Reference)
4260 (Ekind (Id) = E_Entry_Family
4262 Nkind (Parent (Parent (N))) /= N_Attribute_Reference))
4264 -- It is an entry call after all, either to the current task (which
4265 -- will deadlock) or to an enclosing task.
4267 Analyze_Selected_Component (N);
4271 Change_Selected_Component_To_Expanded_Name (N);
4273 -- Do style check and generate reference, but skip both steps if this
4274 -- entity has homonyms, since we may not have the right homonym set yet.
4275 -- The proper homonym will be set during the resolve phase.
4277 if Has_Homonym (Id) then
4280 Set_Entity_With_Style_Check (N, Id);
4281 Generate_Reference (Id, N);
4284 if Is_Type (Id) then
4287 Set_Etype (N, Get_Full_View (Etype (Id)));
4290 -- If the Ekind of the entity is Void, it means that all homonyms are
4291 -- hidden from all visibility (RM 8.3(5,14-20)).
4293 if Ekind (Id) = E_Void then
4294 Premature_Usage (N);
4296 elsif Is_Overloadable (Id)
4297 and then Present (Homonym (Id))
4300 H : Entity_Id := Homonym (Id);
4303 while Present (H) loop
4304 if Scope (H) = Scope (Id)
4307 or else Is_Immediately_Visible (H))
4309 Collect_Interps (N);
4316 -- If an extension of System is present, collect possible explicit
4317 -- overloadings declared in the extension.
4319 if Chars (P_Name) = Name_System
4320 and then Scope (P_Name) = Standard_Standard
4321 and then Present (System_Extend_Unit)
4322 and then Present_System_Aux (N)
4324 H := Current_Entity (Id);
4326 while Present (H) loop
4327 if Scope (H) = System_Aux_Id then
4328 Add_One_Interp (N, H, Etype (H));
4337 if Nkind (Selector_Name (N)) = N_Operator_Symbol
4338 and then Scope (Id) /= Standard_Standard
4340 -- In addition to user-defined operators in the given scope, there
4341 -- may be an implicit instance of the predefined operator. The
4342 -- operator (defined in Standard) is found in Has_Implicit_Operator,
4343 -- and added to the interpretations. Procedure Add_One_Interp will
4344 -- determine which hides which.
4346 if Has_Implicit_Operator (N) then
4350 end Find_Expanded_Name;
4352 -------------------------
4353 -- Find_Renamed_Entity --
4354 -------------------------
4356 function Find_Renamed_Entity
4360 Is_Actual : Boolean := False) return Entity_Id
4363 I1 : Interp_Index := 0; -- Suppress junk warnings
4369 function Enclosing_Instance return Entity_Id;
4370 -- If the renaming determines the entity for the default of a formal
4371 -- subprogram nested within another instance, choose the innermost
4372 -- candidate. This is because if the formal has a box, and we are within
4373 -- an enclosing instance where some candidate interpretations are local
4374 -- to this enclosing instance, we know that the default was properly
4375 -- resolved when analyzing the generic, so we prefer the local
4376 -- candidates to those that are external. This is not always the case
4377 -- but is a reasonable heuristic on the use of nested generics. The
4378 -- proper solution requires a full renaming model.
4380 function Is_Visible_Operation (Op : Entity_Id) return Boolean;
4381 -- If the renamed entity is an implicit operator, check whether it is
4382 -- visible because its operand type is properly visible. This check
4383 -- applies to explicit renamed entities that appear in the source in a
4384 -- renaming declaration or a formal subprogram instance, but not to
4385 -- default generic actuals with a name.
4387 function Report_Overload return Entity_Id;
4388 -- List possible interpretations, and specialize message in the
4389 -- case of a generic actual.
4391 function Within (Inner, Outer : Entity_Id) return Boolean;
4392 -- Determine whether a candidate subprogram is defined within the
4393 -- enclosing instance. If yes, it has precedence over outer candidates.
4395 ------------------------
4396 -- Enclosing_Instance --
4397 ------------------------
4399 function Enclosing_Instance return Entity_Id is
4403 if not Is_Generic_Instance (Current_Scope)
4404 and then not Is_Actual
4409 S := Scope (Current_Scope);
4410 while S /= Standard_Standard loop
4411 if Is_Generic_Instance (S) then
4419 end Enclosing_Instance;
4421 --------------------------
4422 -- Is_Visible_Operation --
4423 --------------------------
4425 function Is_Visible_Operation (Op : Entity_Id) return Boolean is
4431 if Ekind (Op) /= E_Operator
4432 or else Scope (Op) /= Standard_Standard
4433 or else (In_Instance
4436 or else Present (Enclosing_Instance)))
4441 -- For a fixed point type operator, check the resulting type,
4442 -- because it may be a mixed mode integer * fixed operation.
4444 if Present (Next_Formal (First_Formal (New_S)))
4445 and then Is_Fixed_Point_Type (Etype (New_S))
4447 Typ := Etype (New_S);
4449 Typ := Etype (First_Formal (New_S));
4452 Btyp := Base_Type (Typ);
4454 if Nkind (Nam) /= N_Expanded_Name then
4455 return (In_Open_Scopes (Scope (Btyp))
4456 or else Is_Potentially_Use_Visible (Btyp)
4457 or else In_Use (Btyp)
4458 or else In_Use (Scope (Btyp)));
4461 Scop := Entity (Prefix (Nam));
4463 if Ekind (Scop) = E_Package
4464 and then Present (Renamed_Object (Scop))
4466 Scop := Renamed_Object (Scop);
4469 -- Operator is visible if prefix of expanded name denotes
4470 -- scope of type, or else type type is defined in System_Aux
4471 -- and the prefix denotes System.
4473 return Scope (Btyp) = Scop
4474 or else (Scope (Btyp) = System_Aux_Id
4475 and then Scope (Scope (Btyp)) = Scop);
4478 end Is_Visible_Operation;
4484 function Within (Inner, Outer : Entity_Id) return Boolean is
4488 Sc := Scope (Inner);
4489 while Sc /= Standard_Standard loop
4500 ---------------------
4501 -- Report_Overload --
4502 ---------------------
4504 function Report_Overload return Entity_Id is
4508 ("ambiguous actual subprogram&, " &
4509 "possible interpretations:", N, Nam);
4512 ("ambiguous subprogram, " &
4513 "possible interpretations:", N);
4516 List_Interps (Nam, N);
4518 end Report_Overload;
4520 -- Start of processing for Find_Renamed_Entry
4524 Candidate_Renaming := Empty;
4526 if not Is_Overloaded (Nam) then
4527 if Entity_Matches_Spec (Entity (Nam), New_S)
4528 and then Is_Visible_Operation (Entity (Nam))
4530 Old_S := Entity (Nam);
4533 Present (First_Formal (Entity (Nam)))
4534 and then Present (First_Formal (New_S))
4535 and then (Base_Type (Etype (First_Formal (Entity (Nam))))
4536 = Base_Type (Etype (First_Formal (New_S))))
4538 Candidate_Renaming := Entity (Nam);
4542 Get_First_Interp (Nam, Ind, It);
4543 while Present (It.Nam) loop
4544 if Entity_Matches_Spec (It.Nam, New_S)
4545 and then Is_Visible_Operation (It.Nam)
4547 if Old_S /= Any_Id then
4549 -- Note: The call to Disambiguate only happens if a
4550 -- previous interpretation was found, in which case I1
4551 -- has received a value.
4553 It1 := Disambiguate (Nam, I1, Ind, Etype (Old_S));
4555 if It1 = No_Interp then
4556 Inst := Enclosing_Instance;
4558 if Present (Inst) then
4559 if Within (It.Nam, Inst) then
4561 elsif Within (Old_S, Inst) then
4564 return Report_Overload;
4568 return Report_Overload;
4582 Present (First_Formal (It.Nam))
4583 and then Present (First_Formal (New_S))
4584 and then (Base_Type (Etype (First_Formal (It.Nam)))
4585 = Base_Type (Etype (First_Formal (New_S))))
4587 Candidate_Renaming := It.Nam;
4590 Get_Next_Interp (Ind, It);
4593 Set_Entity (Nam, Old_S);
4594 Set_Is_Overloaded (Nam, False);
4598 end Find_Renamed_Entity;
4600 -----------------------------
4601 -- Find_Selected_Component --
4602 -----------------------------
4604 procedure Find_Selected_Component (N : Node_Id) is
4605 P : constant Node_Id := Prefix (N);
4608 -- Entity denoted by prefix
4618 if Nkind (P) = N_Error then
4621 -- If the selector already has an entity, the node has been constructed
4622 -- in the course of expansion, and is known to be valid. Do not verify
4623 -- that it is defined for the type (it may be a private component used
4624 -- in the expansion of record equality).
4626 elsif Present (Entity (Selector_Name (N))) then
4629 or else Etype (N) = Any_Type
4632 Sel_Name : constant Node_Id := Selector_Name (N);
4633 Selector : constant Entity_Id := Entity (Sel_Name);
4637 Set_Etype (Sel_Name, Etype (Selector));
4639 if not Is_Entity_Name (P) then
4643 -- Build an actual subtype except for the first parameter
4644 -- of an init proc, where this actual subtype is by
4645 -- definition incorrect, since the object is uninitialized
4646 -- (and does not even have defined discriminants etc.)
4648 if Is_Entity_Name (P)
4649 and then Ekind (Entity (P)) = E_Function
4651 Nam := New_Copy (P);
4653 if Is_Overloaded (P) then
4654 Save_Interps (P, Nam);
4658 Make_Function_Call (Sloc (P), Name => Nam));
4660 Analyze_Selected_Component (N);
4663 elsif Ekind (Selector) = E_Component
4664 and then (not Is_Entity_Name (P)
4665 or else Chars (Entity (P)) /= Name_uInit)
4668 Build_Actual_Subtype_Of_Component (
4669 Etype (Selector), N);
4674 if No (C_Etype) then
4675 C_Etype := Etype (Selector);
4677 Insert_Action (N, C_Etype);
4678 C_Etype := Defining_Identifier (C_Etype);
4681 Set_Etype (N, C_Etype);
4684 -- If this is the name of an entry or protected operation, and
4685 -- the prefix is an access type, insert an explicit dereference,
4686 -- so that entry calls are treated uniformly.
4688 if Is_Access_Type (Etype (P))
4689 and then Is_Concurrent_Type (Designated_Type (Etype (P)))
4692 New_P : constant Node_Id :=
4693 Make_Explicit_Dereference (Sloc (P),
4694 Prefix => Relocate_Node (P));
4697 Set_Etype (P, Designated_Type (Etype (Prefix (P))));
4701 -- If the selected component appears within a default expression
4702 -- and it has an actual subtype, the pre-analysis has not yet
4703 -- completed its analysis, because Insert_Actions is disabled in
4704 -- that context. Within the init proc of the enclosing type we
4705 -- must complete this analysis, if an actual subtype was created.
4707 elsif Inside_Init_Proc then
4709 Typ : constant Entity_Id := Etype (N);
4710 Decl : constant Node_Id := Declaration_Node (Typ);
4712 if Nkind (Decl) = N_Subtype_Declaration
4713 and then not Analyzed (Decl)
4714 and then Is_List_Member (Decl)
4715 and then No (Parent (Decl))
4718 Insert_Action (N, Decl);
4725 elsif Is_Entity_Name (P) then
4726 P_Name := Entity (P);
4728 -- The prefix may denote an enclosing type which is the completion
4729 -- of an incomplete type declaration.
4731 if Is_Type (P_Name) then
4732 Set_Entity (P, Get_Full_View (P_Name));
4733 Set_Etype (P, Entity (P));
4734 P_Name := Entity (P);
4737 P_Type := Base_Type (Etype (P));
4739 if Debug_Flag_E then
4740 Write_Str ("Found prefix type to be ");
4741 Write_Entity_Info (P_Type, " "); Write_Eol;
4744 -- First check for components of a record object (not the
4745 -- result of a call, which is handled below).
4747 if Is_Appropriate_For_Record (P_Type)
4748 and then not Is_Overloadable (P_Name)
4749 and then not Is_Type (P_Name)
4751 -- Selected component of record. Type checking will validate
4752 -- name of selector.
4753 -- ??? could we rewrite an implicit dereference into an explicit
4756 Analyze_Selected_Component (N);
4758 elsif Is_Appropriate_For_Entry_Prefix (P_Type)
4759 and then not In_Open_Scopes (P_Name)
4760 and then (not Is_Concurrent_Type (Etype (P_Name))
4761 or else not In_Open_Scopes (Etype (P_Name)))
4763 -- Call to protected operation or entry. Type checking is
4764 -- needed on the prefix.
4766 Analyze_Selected_Component (N);
4768 elsif (In_Open_Scopes (P_Name)
4769 and then Ekind (P_Name) /= E_Void
4770 and then not Is_Overloadable (P_Name))
4771 or else (Is_Concurrent_Type (Etype (P_Name))
4772 and then In_Open_Scopes (Etype (P_Name)))
4774 -- Prefix denotes an enclosing loop, block, or task, i.e. an
4775 -- enclosing construct that is not a subprogram or accept.
4777 Find_Expanded_Name (N);
4779 elsif Ekind (P_Name) = E_Package then
4780 Find_Expanded_Name (N);
4782 elsif Is_Overloadable (P_Name) then
4784 -- The subprogram may be a renaming (of an enclosing scope) as
4785 -- in the case of the name of the generic within an instantiation.
4787 if (Ekind (P_Name) = E_Procedure
4788 or else Ekind (P_Name) = E_Function)
4789 and then Present (Alias (P_Name))
4790 and then Is_Generic_Instance (Alias (P_Name))
4792 P_Name := Alias (P_Name);
4795 if Is_Overloaded (P) then
4797 -- The prefix must resolve to a unique enclosing construct
4800 Found : Boolean := False;
4805 Get_First_Interp (P, Ind, It);
4806 while Present (It.Nam) loop
4807 if In_Open_Scopes (It.Nam) then
4810 "prefix must be unique enclosing scope", N);
4811 Set_Entity (N, Any_Id);
4812 Set_Etype (N, Any_Type);
4821 Get_Next_Interp (Ind, It);
4826 if In_Open_Scopes (P_Name) then
4827 Set_Entity (P, P_Name);
4828 Set_Is_Overloaded (P, False);
4829 Find_Expanded_Name (N);
4832 -- If no interpretation as an expanded name is possible, it
4833 -- must be a selected component of a record returned by a
4834 -- function call. Reformat prefix as a function call, the rest
4835 -- is done by type resolution. If the prefix is procedure or
4836 -- entry, as is P.X; this is an error.
4838 if Ekind (P_Name) /= E_Function
4839 and then (not Is_Overloaded (P)
4841 Nkind (Parent (N)) = N_Procedure_Call_Statement)
4843 -- Prefix may mention a package that is hidden by a local
4844 -- declaration: let the user know. Scan the full homonym
4845 -- chain, the candidate package may be anywhere on it.
4847 if Present (Homonym (Current_Entity (P_Name))) then
4849 P_Name := Current_Entity (P_Name);
4851 while Present (P_Name) loop
4852 exit when Ekind (P_Name) = E_Package;
4853 P_Name := Homonym (P_Name);
4856 if Present (P_Name) then
4857 Error_Msg_Sloc := Sloc (Entity (Prefix (N)));
4860 ("package& is hidden by declaration#",
4863 Set_Entity (Prefix (N), P_Name);
4864 Find_Expanded_Name (N);
4867 P_Name := Entity (Prefix (N));
4872 ("invalid prefix in selected component&", N, P_Name);
4873 Change_Selected_Component_To_Expanded_Name (N);
4874 Set_Entity (N, Any_Id);
4875 Set_Etype (N, Any_Type);
4878 Nam := New_Copy (P);
4879 Save_Interps (P, Nam);
4881 Make_Function_Call (Sloc (P), Name => Nam));
4883 Analyze_Selected_Component (N);
4887 -- Remaining cases generate various error messages
4890 -- Format node as expanded name, to avoid cascaded errors
4892 Change_Selected_Component_To_Expanded_Name (N);
4893 Set_Entity (N, Any_Id);
4894 Set_Etype (N, Any_Type);
4896 -- Issue error message, but avoid this if error issued already.
4897 -- Use identifier of prefix if one is available.
4899 if P_Name = Any_Id then
4902 elsif Ekind (P_Name) = E_Void then
4903 Premature_Usage (P);
4905 elsif Nkind (P) /= N_Attribute_Reference then
4907 "invalid prefix in selected component&", P);
4909 if Is_Access_Type (P_Type)
4910 and then Ekind (Designated_Type (P_Type)) = E_Incomplete_Type
4913 ("\dereference must not be of an incomplete type " &
4919 "invalid prefix in selected component", P);
4924 -- If prefix is not the name of an entity, it must be an expression,
4925 -- whose type is appropriate for a record. This is determined by
4928 Analyze_Selected_Component (N);
4930 end Find_Selected_Component;
4936 procedure Find_Type (N : Node_Id) is
4946 elsif Nkind (N) = N_Attribute_Reference then
4948 -- Class attribute. This is not valid in Ada 83 mode, but we do not
4949 -- need to enforce that at this point, since the declaration of the
4950 -- tagged type in the prefix would have been flagged already.
4952 if Attribute_Name (N) = Name_Class then
4953 Check_Restriction (No_Dispatch, N);
4954 Find_Type (Prefix (N));
4956 -- Propagate error from bad prefix
4958 if Etype (Prefix (N)) = Any_Type then
4959 Set_Entity (N, Any_Type);
4960 Set_Etype (N, Any_Type);
4964 T := Base_Type (Entity (Prefix (N)));
4966 -- Case where type is not known to be tagged. Its appearance in
4967 -- the prefix of the 'Class attribute indicates that the full view
4970 if not Is_Tagged_Type (T) then
4971 if Ekind (T) = E_Incomplete_Type then
4973 -- It is legal to denote the class type of an incomplete
4974 -- type. The full type will have to be tagged, of course.
4975 -- In Ada2005 this usage is declared obsolescent, so we
4976 -- warn accordingly.
4978 -- ??? This test is temporarily disabled (always False)
4979 -- because it causes an unwanted warning on GNAT sources
4980 -- (built with -gnatg, which includes Warn_On_Obsolescent_
4981 -- Feature). Once this issue is cleared in the sources, it
4984 if not Is_Tagged_Type (T)
4985 and then Ada_Version >= Ada_05
4986 and then Warn_On_Obsolescent_Feature
4990 ("applying 'Class to an untagged imcomplete type"
4991 & " is an obsolescent feature (RM J.11)", N);
4994 Set_Is_Tagged_Type (T);
4995 Set_Primitive_Operations (T, New_Elmt_List);
4996 Make_Class_Wide_Type (T);
4997 Set_Entity (N, Class_Wide_Type (T));
4998 Set_Etype (N, Class_Wide_Type (T));
5000 elsif Ekind (T) = E_Private_Type
5001 and then not Is_Generic_Type (T)
5002 and then In_Private_Part (Scope (T))
5004 -- The Class attribute can be applied to an untagged private
5005 -- type fulfilled by a tagged type prior to the full type
5006 -- declaration (but only within the parent package's private
5007 -- part). Create the class-wide type now and check that the
5008 -- full type is tagged later during its analysis. Note that
5009 -- we do not mark the private type as tagged, unlike the
5010 -- case of incomplete types, because the type must still
5011 -- appear untagged to outside units.
5013 if No (Class_Wide_Type (T)) then
5014 Make_Class_Wide_Type (T);
5017 Set_Entity (N, Class_Wide_Type (T));
5018 Set_Etype (N, Class_Wide_Type (T));
5021 -- Should we introduce a type Any_Tagged and use Wrong_Type
5022 -- here, it would be a bit more consistent???
5025 ("tagged type required, found}",
5026 Prefix (N), First_Subtype (T));
5027 Set_Entity (N, Any_Type);
5031 -- Case of tagged type
5034 if Is_Concurrent_Type (T) then
5035 if No (Corresponding_Record_Type (Entity (Prefix (N)))) then
5037 -- Previous error. Use current type, which at least
5038 -- provides some operations.
5040 C := Entity (Prefix (N));
5043 C := Class_Wide_Type
5044 (Corresponding_Record_Type (Entity (Prefix (N))));
5048 C := Class_Wide_Type (Entity (Prefix (N)));
5051 Set_Entity_With_Style_Check (N, C);
5052 Generate_Reference (C, N);
5056 -- Base attribute, not allowed in Ada 83
5058 elsif Attribute_Name (N) = Name_Base then
5059 if Ada_Version = Ada_83 and then Comes_From_Source (N) then
5061 ("(Ada 83) Base attribute not allowed in subtype mark", N);
5064 Find_Type (Prefix (N));
5065 Typ := Entity (Prefix (N));
5067 if Ada_Version >= Ada_95
5068 and then not Is_Scalar_Type (Typ)
5069 and then not Is_Generic_Type (Typ)
5072 ("prefix of Base attribute must be scalar type",
5075 elsif Sloc (Typ) = Standard_Location
5076 and then Base_Type (Typ) = Typ
5077 and then Warn_On_Redundant_Constructs
5080 ("?redudant attribute, & is its own base type", N, Typ);
5083 T := Base_Type (Typ);
5085 -- Rewrite attribute reference with type itself (see similar
5086 -- processing in Analyze_Attribute, case Base). Preserve
5087 -- prefix if present, for other legality checks.
5089 if Nkind (Prefix (N)) = N_Expanded_Name then
5091 Make_Expanded_Name (Sloc (N),
5093 Prefix => New_Copy (Prefix (Prefix (N))),
5094 Selector_Name => New_Reference_To (T, Sloc (N))));
5097 Rewrite (N, New_Reference_To (T, Sloc (N)));
5104 elsif Attribute_Name (N) = Name_Stub_Type then
5106 -- This is handled in Analyze_Attribute
5110 -- All other attributes are invalid in a subtype mark
5113 Error_Msg_N ("invalid attribute in subtype mark", N);
5119 if Is_Entity_Name (N) then
5120 T_Name := Entity (N);
5122 Error_Msg_N ("subtype mark required in this context", N);
5123 Set_Etype (N, Any_Type);
5127 if T_Name = Any_Id or else Etype (N) = Any_Type then
5129 -- Undefined id. Make it into a valid type
5131 Set_Entity (N, Any_Type);
5133 elsif not Is_Type (T_Name)
5134 and then T_Name /= Standard_Void_Type
5136 Error_Msg_Sloc := Sloc (T_Name);
5137 Error_Msg_N ("subtype mark required in this context", N);
5138 Error_Msg_NE ("\\found & declared#", N, T_Name);
5139 Set_Entity (N, Any_Type);
5142 -- If the type is an incomplete type created to handle
5143 -- anonymous access components of a record type, then the
5144 -- incomplete type is the visible entity and subsequent
5145 -- references will point to it. Mark the original full
5146 -- type as referenced, to prevent spurious warnings.
5148 if Is_Incomplete_Type (T_Name)
5149 and then Present (Full_View (T_Name))
5150 and then not Comes_From_Source (T_Name)
5152 Set_Referenced (Full_View (T_Name));
5155 T_Name := Get_Full_View (T_Name);
5157 -- Ada 2005 (AI-251, AI-50217): Handle interfaces visible through
5158 -- limited-with clauses
5160 if From_With_Type (T_Name)
5161 and then Ekind (T_Name) in Incomplete_Kind
5162 and then Present (Non_Limited_View (T_Name))
5163 and then Is_Interface (Non_Limited_View (T_Name))
5165 T_Name := Non_Limited_View (T_Name);
5168 if In_Open_Scopes (T_Name) then
5169 if Ekind (Base_Type (T_Name)) = E_Task_Type then
5171 -- In Ada 2005, a task name can be used in an access
5172 -- definition within its own body.
5174 if Ada_Version >= Ada_05
5175 and then Nkind (Parent (N)) = N_Access_Definition
5177 Set_Entity (N, T_Name);
5178 Set_Etype (N, T_Name);
5183 ("task type cannot be used as type mark " &
5184 "within its own spec or body", N);
5187 elsif Ekind (Base_Type (T_Name)) = E_Protected_Type then
5189 -- In Ada 2005, a protected name can be used in an access
5190 -- definition within its own body.
5192 if Ada_Version >= Ada_05
5193 and then Nkind (Parent (N)) = N_Access_Definition
5195 Set_Entity (N, T_Name);
5196 Set_Etype (N, T_Name);
5201 ("protected type cannot be used as type mark " &
5202 "within its own spec or body", N);
5206 Error_Msg_N ("type declaration cannot refer to itself", N);
5209 Set_Etype (N, Any_Type);
5210 Set_Entity (N, Any_Type);
5211 Set_Error_Posted (T_Name);
5215 Set_Entity (N, T_Name);
5216 Set_Etype (N, T_Name);
5220 if Present (Etype (N)) and then Comes_From_Source (N) then
5221 if Is_Fixed_Point_Type (Etype (N)) then
5222 Check_Restriction (No_Fixed_Point, N);
5223 elsif Is_Floating_Point_Type (Etype (N)) then
5224 Check_Restriction (No_Floating_Point, N);
5229 ------------------------------------
5230 -- Has_Implicit_Character_Literal --
5231 ------------------------------------
5233 function Has_Implicit_Character_Literal (N : Node_Id) return Boolean is
5235 Found : Boolean := False;
5236 P : constant Entity_Id := Entity (Prefix (N));
5237 Priv_Id : Entity_Id := Empty;
5240 if Ekind (P) = E_Package
5241 and then not In_Open_Scopes (P)
5243 Priv_Id := First_Private_Entity (P);
5246 if P = Standard_Standard then
5247 Change_Selected_Component_To_Expanded_Name (N);
5248 Rewrite (N, Selector_Name (N));
5250 Set_Etype (Original_Node (N), Standard_Character);
5254 Id := First_Entity (P);
5257 and then Id /= Priv_Id
5259 if Is_Character_Type (Id)
5260 and then (Root_Type (Id) = Standard_Character
5261 or else Root_Type (Id) = Standard_Wide_Character
5262 or else Root_Type (Id) = Standard_Wide_Wide_Character)
5263 and then Id = Base_Type (Id)
5265 -- We replace the node with the literal itself, resolve as a
5266 -- character, and set the type correctly.
5269 Change_Selected_Component_To_Expanded_Name (N);
5270 Rewrite (N, Selector_Name (N));
5273 Set_Etype (Original_Node (N), Id);
5277 -- More than one type derived from Character in given scope.
5278 -- Collect all possible interpretations.
5280 Add_One_Interp (N, Id, Id);
5288 end Has_Implicit_Character_Literal;
5290 ----------------------
5291 -- Has_Private_With --
5292 ----------------------
5294 function Has_Private_With (E : Entity_Id) return Boolean is
5295 Comp_Unit : constant Node_Id := Cunit (Current_Sem_Unit);
5299 Item := First (Context_Items (Comp_Unit));
5300 while Present (Item) loop
5301 if Nkind (Item) = N_With_Clause
5302 and then Private_Present (Item)
5303 and then Entity (Name (Item)) = E
5312 end Has_Private_With;
5314 ---------------------------
5315 -- Has_Implicit_Operator --
5316 ---------------------------
5318 function Has_Implicit_Operator (N : Node_Id) return Boolean is
5319 Op_Id : constant Name_Id := Chars (Selector_Name (N));
5320 P : constant Entity_Id := Entity (Prefix (N));
5322 Priv_Id : Entity_Id := Empty;
5324 procedure Add_Implicit_Operator
5326 Op_Type : Entity_Id := Empty);
5327 -- Add implicit interpretation to node N, using the type for which a
5328 -- predefined operator exists. If the operator yields a boolean type,
5329 -- the Operand_Type is implicitly referenced by the operator, and a
5330 -- reference to it must be generated.
5332 ---------------------------
5333 -- Add_Implicit_Operator --
5334 ---------------------------
5336 procedure Add_Implicit_Operator
5338 Op_Type : Entity_Id := Empty)
5340 Predef_Op : Entity_Id;
5343 Predef_Op := Current_Entity (Selector_Name (N));
5345 while Present (Predef_Op)
5346 and then Scope (Predef_Op) /= Standard_Standard
5348 Predef_Op := Homonym (Predef_Op);
5351 if Nkind (N) = N_Selected_Component then
5352 Change_Selected_Component_To_Expanded_Name (N);
5355 Add_One_Interp (N, Predef_Op, T);
5357 -- For operators with unary and binary interpretations, add both
5359 if Present (Homonym (Predef_Op)) then
5360 Add_One_Interp (N, Homonym (Predef_Op), T);
5363 -- The node is a reference to a predefined operator, and
5364 -- an implicit reference to the type of its operands.
5366 if Present (Op_Type) then
5367 Generate_Operator_Reference (N, Op_Type);
5369 Generate_Operator_Reference (N, T);
5371 end Add_Implicit_Operator;
5373 -- Start of processing for Has_Implicit_Operator
5376 if Ekind (P) = E_Package
5377 and then not In_Open_Scopes (P)
5379 Priv_Id := First_Private_Entity (P);
5382 Id := First_Entity (P);
5386 -- Boolean operators: an implicit declaration exists if the scope
5387 -- contains a declaration for a derived Boolean type, or for an
5388 -- array of Boolean type.
5390 when Name_Op_And | Name_Op_Not | Name_Op_Or | Name_Op_Xor =>
5391 while Id /= Priv_Id loop
5392 if Valid_Boolean_Arg (Id)
5393 and then Id = Base_Type (Id)
5395 Add_Implicit_Operator (Id);
5402 -- Equality: look for any non-limited type (result is Boolean)
5404 when Name_Op_Eq | Name_Op_Ne =>
5405 while Id /= Priv_Id loop
5407 and then not Is_Limited_Type (Id)
5408 and then Id = Base_Type (Id)
5410 Add_Implicit_Operator (Standard_Boolean, Id);
5417 -- Comparison operators: scalar type, or array of scalar
5419 when Name_Op_Lt | Name_Op_Le | Name_Op_Gt | Name_Op_Ge =>
5420 while Id /= Priv_Id loop
5421 if (Is_Scalar_Type (Id)
5422 or else (Is_Array_Type (Id)
5423 and then Is_Scalar_Type (Component_Type (Id))))
5424 and then Id = Base_Type (Id)
5426 Add_Implicit_Operator (Standard_Boolean, Id);
5433 -- Arithmetic operators: any numeric type
5443 while Id /= Priv_Id loop
5444 if Is_Numeric_Type (Id)
5445 and then Id = Base_Type (Id)
5447 Add_Implicit_Operator (Id);
5454 -- Concatenation: any one-dimensional array type
5456 when Name_Op_Concat =>
5457 while Id /= Priv_Id loop
5458 if Is_Array_Type (Id) and then Number_Dimensions (Id) = 1
5459 and then Id = Base_Type (Id)
5461 Add_Implicit_Operator (Id);
5468 -- What is the others condition here? Should we be using a
5469 -- subtype of Name_Id that would restrict to operators ???
5471 when others => null;
5474 -- If we fall through, then we do not have an implicit operator
5478 end Has_Implicit_Operator;
5480 --------------------
5481 -- In_Open_Scopes --
5482 --------------------
5484 function In_Open_Scopes (S : Entity_Id) return Boolean is
5486 -- Several scope stacks are maintained by Scope_Stack. The base of the
5487 -- currently active scope stack is denoted by the Is_Active_Stack_Base
5488 -- flag in the scope stack entry. Note that the scope stacks used to
5489 -- simply be delimited implicitly by the presence of Standard_Standard
5490 -- at their base, but there now are cases where this is not sufficient
5491 -- because Standard_Standard actually may appear in the middle of the
5492 -- active set of scopes.
5494 for J in reverse 0 .. Scope_Stack.Last loop
5495 if Scope_Stack.Table (J).Entity = S then
5499 -- Check Is_Active_Stack_Base to tell us when to stop, as there are
5500 -- cases where Standard_Standard appears in the middle of the active
5501 -- set of scopes. This affects the declaration and overriding of
5502 -- private inherited operations in instantiations of generic child
5505 exit when Scope_Stack.Table (J).Is_Active_Stack_Base;
5511 -----------------------------
5512 -- Inherit_Renamed_Profile --
5513 -----------------------------
5515 procedure Inherit_Renamed_Profile (New_S : Entity_Id; Old_S : Entity_Id) is
5522 if Ekind (Old_S) = E_Operator then
5523 New_F := First_Formal (New_S);
5525 while Present (New_F) loop
5526 Set_Etype (New_F, Base_Type (Etype (New_F)));
5527 Next_Formal (New_F);
5530 Set_Etype (New_S, Base_Type (Etype (New_S)));
5533 New_F := First_Formal (New_S);
5534 Old_F := First_Formal (Old_S);
5536 while Present (New_F) loop
5537 New_T := Etype (New_F);
5538 Old_T := Etype (Old_F);
5540 -- If the new type is a renaming of the old one, as is the
5541 -- case for actuals in instances, retain its name, to simplify
5542 -- later disambiguation.
5544 if Nkind (Parent (New_T)) = N_Subtype_Declaration
5545 and then Is_Entity_Name (Subtype_Indication (Parent (New_T)))
5546 and then Entity (Subtype_Indication (Parent (New_T))) = Old_T
5550 Set_Etype (New_F, Old_T);
5553 Next_Formal (New_F);
5554 Next_Formal (Old_F);
5557 if Ekind (Old_S) = E_Function
5558 or else Ekind (Old_S) = E_Enumeration_Literal
5560 Set_Etype (New_S, Etype (Old_S));
5563 end Inherit_Renamed_Profile;
5569 procedure Initialize is
5574 -------------------------
5575 -- Install_Use_Clauses --
5576 -------------------------
5578 procedure Install_Use_Clauses
5580 Force_Installation : Boolean := False)
5588 while Present (U) loop
5590 -- Case of USE package
5592 if Nkind (U) = N_Use_Package_Clause then
5593 P := First (Names (U));
5594 while Present (P) loop
5597 if Ekind (Id) = E_Package then
5599 Note_Redundant_Use (P);
5601 elsif Present (Renamed_Object (Id))
5602 and then In_Use (Renamed_Object (Id))
5604 Note_Redundant_Use (P);
5606 elsif Force_Installation or else Applicable_Use (P) then
5607 Use_One_Package (Id, U);
5618 P := First (Subtype_Marks (U));
5619 while Present (P) loop
5620 if not Is_Entity_Name (P)
5621 or else No (Entity (P))
5625 elsif Entity (P) /= Any_Type then
5633 Next_Use_Clause (U);
5635 end Install_Use_Clauses;
5637 -------------------------------------
5638 -- Is_Appropriate_For_Entry_Prefix --
5639 -------------------------------------
5641 function Is_Appropriate_For_Entry_Prefix (T : Entity_Id) return Boolean is
5642 P_Type : Entity_Id := T;
5645 if Is_Access_Type (P_Type) then
5646 P_Type := Designated_Type (P_Type);
5649 return Is_Task_Type (P_Type) or else Is_Protected_Type (P_Type);
5650 end Is_Appropriate_For_Entry_Prefix;
5652 -------------------------------
5653 -- Is_Appropriate_For_Record --
5654 -------------------------------
5656 function Is_Appropriate_For_Record (T : Entity_Id) return Boolean is
5658 function Has_Components (T1 : Entity_Id) return Boolean;
5659 -- Determine if given type has components (i.e. is either a record
5660 -- type or a type that has discriminants).
5662 --------------------
5663 -- Has_Components --
5664 --------------------
5666 function Has_Components (T1 : Entity_Id) return Boolean is
5668 return Is_Record_Type (T1)
5669 or else (Is_Private_Type (T1) and then Has_Discriminants (T1))
5670 or else (Is_Task_Type (T1) and then Has_Discriminants (T1))
5671 or else (Is_Incomplete_Type (T1)
5672 and then From_With_Type (T1)
5673 and then Present (Non_Limited_View (T1))
5674 and then Is_Record_Type
5675 (Get_Full_View (Non_Limited_View (T1))));
5678 -- Start of processing for Is_Appropriate_For_Record
5683 and then (Has_Components (T)
5684 or else (Is_Access_Type (T)
5685 and then Has_Components (Designated_Type (T))));
5686 end Is_Appropriate_For_Record;
5688 ------------------------
5689 -- Note_Redundant_Use --
5690 ------------------------
5692 procedure Note_Redundant_Use (Clause : Node_Id) is
5693 Pack_Name : constant Entity_Id := Entity (Clause);
5694 Cur_Use : constant Node_Id := Current_Use_Clause (Pack_Name);
5695 Decl : constant Node_Id := Parent (Clause);
5697 Prev_Use : Node_Id := Empty;
5698 Redundant : Node_Id := Empty;
5699 -- The Use_Clause which is actually redundant. In the simplest case
5700 -- it is Pack itself, but when we compile a body we install its
5701 -- context before that of its spec, in which case it is the use_clause
5702 -- in the spec that will appear to be redundant, and we want the
5703 -- warning to be placed on the body. Similar complications appear when
5704 -- the redundancy is between a child unit and one of its ancestors.
5707 Set_Redundant_Use (Clause, True);
5709 if not Comes_From_Source (Clause)
5711 or else not Warn_On_Redundant_Constructs
5716 if not Is_Compilation_Unit (Current_Scope) then
5718 -- If the use_clause is in an inner scope, it is made redundant
5719 -- by some clause in the current context, with one exception:
5720 -- If we're compiling a nested package body, and the use_clause
5721 -- comes from the corresponding spec, the clause is not necessarily
5722 -- fully redundant, so we should not warn. If a warning was
5723 -- warranted, it would have been given when the spec was processed.
5725 if Nkind (Parent (Decl)) = N_Package_Specification then
5727 Package_Spec_Entity : constant Entity_Id :=
5728 Defining_Unit_Name (Parent (Decl));
5730 if In_Package_Body (Package_Spec_Entity) then
5736 Redundant := Clause;
5737 Prev_Use := Cur_Use;
5739 elsif Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Body then
5741 Cur_Unit : constant Unit_Number_Type := Get_Source_Unit (Cur_Use);
5742 New_Unit : constant Unit_Number_Type := Get_Source_Unit (Clause);
5746 if Cur_Unit = New_Unit then
5748 -- Redundant clause in same body
5750 Redundant := Clause;
5751 Prev_Use := Cur_Use;
5753 elsif Cur_Unit = Current_Sem_Unit then
5755 -- If the new clause is not in the current unit it has been
5756 -- analyzed first, and it makes the other one redundant.
5757 -- However, if the new clause appears in a subunit, Cur_Unit
5758 -- is still the parent, and in that case the redundant one
5759 -- is the one appearing in the subunit.
5761 if Nkind (Unit (Cunit (New_Unit))) = N_Subunit then
5762 Redundant := Clause;
5763 Prev_Use := Cur_Use;
5765 -- Most common case: redundant clause in body,
5766 -- original clause in spec. Current scope is spec entity.
5771 Unit (Library_Unit (Cunit (Current_Sem_Unit))))
5773 Redundant := Cur_Use;
5777 -- The new clause may appear in an unrelated unit, when
5778 -- the parents of a generic are being installed prior to
5779 -- instantiation. In this case there must be no warning.
5780 -- We detect this case by checking whether the current top
5781 -- of the stack is related to the current compilation.
5783 Scop := Current_Scope;
5784 while Present (Scop)
5785 and then Scop /= Standard_Standard
5787 if Is_Compilation_Unit (Scop)
5788 and then not Is_Child_Unit (Scop)
5792 elsif Scop = Cunit_Entity (Current_Sem_Unit) then
5796 Scop := Scope (Scop);
5799 Redundant := Cur_Use;
5803 elsif New_Unit = Current_Sem_Unit then
5804 Redundant := Clause;
5805 Prev_Use := Cur_Use;
5808 -- Neither is the current unit, so they appear in parent or
5809 -- sibling units. Warning will be emitted elsewhere.
5815 elsif Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Declaration
5816 and then Present (Parent_Spec (Unit (Cunit (Current_Sem_Unit))))
5818 -- Use_clause is in child unit of current unit, and the child
5819 -- unit appears in the context of the body of the parent, so it
5820 -- has been installed first, even though it is the redundant one.
5821 -- Depending on their placement in the context, the visible or the
5822 -- private parts of the two units, either might appear as redundant,
5823 -- but the message has to be on the current unit.
5825 if Get_Source_Unit (Cur_Use) = Current_Sem_Unit then
5826 Redundant := Cur_Use;
5829 Redundant := Clause;
5830 Prev_Use := Cur_Use;
5833 -- If the new use clause appears in the private part of a parent unit
5834 -- it may appear to be redudant w.r.t. a use clause in a child unit,
5835 -- but the previous use clause was needed in the visible part of the
5836 -- child, and no warning should be emitted.
5838 if Nkind (Parent (Decl)) = N_Package_Specification
5840 List_Containing (Decl) = Private_Declarations (Parent (Decl))
5843 Par : constant Entity_Id := Defining_Entity (Parent (Decl));
5844 Spec : constant Node_Id :=
5845 Specification (Unit (Cunit (Current_Sem_Unit)));
5848 if Is_Compilation_Unit (Par)
5849 and then Par /= Cunit_Entity (Current_Sem_Unit)
5850 and then Parent (Cur_Use) = Spec
5852 List_Containing (Cur_Use) = Visible_Declarations (Spec)
5863 if Present (Redundant) then
5864 Error_Msg_Sloc := Sloc (Prev_Use);
5866 "& is already use_visible through declaration #?",
5867 Redundant, Pack_Name);
5869 end Note_Redundant_Use;
5875 procedure Pop_Scope is
5876 SST : Scope_Stack_Entry renames Scope_Stack.Table (Scope_Stack.Last);
5879 if Debug_Flag_E then
5883 Scope_Suppress := SST.Save_Scope_Suppress;
5884 Local_Suppress_Stack_Top := SST.Save_Local_Suppress_Stack_Top;
5886 if Debug_Flag_W then
5887 Write_Str ("--> exiting scope: ");
5888 Write_Name (Chars (Current_Scope));
5889 Write_Str (", Depth=");
5890 Write_Int (Int (Scope_Stack.Last));
5894 End_Use_Clauses (SST.First_Use_Clause);
5896 -- If the actions to be wrapped are still there they will get lost
5897 -- causing incomplete code to be generated. It is better to abort in
5898 -- this case (and we do the abort even with assertions off since the
5899 -- penalty is incorrect code generation)
5901 if SST.Actions_To_Be_Wrapped_Before /= No_List
5903 SST.Actions_To_Be_Wrapped_After /= No_List
5908 -- Free last subprogram name if allocated, and pop scope
5910 Free (SST.Last_Subprogram_Name);
5911 Scope_Stack.Decrement_Last;
5918 procedure Push_Scope (S : Entity_Id) is
5922 if Ekind (S) = E_Void then
5925 -- Set scope depth if not a non-concurrent type, and we have not
5926 -- yet set the scope depth. This means that we have the first
5927 -- occurrence of the scope, and this is where the depth is set.
5929 elsif (not Is_Type (S) or else Is_Concurrent_Type (S))
5930 and then not Scope_Depth_Set (S)
5932 if S = Standard_Standard then
5933 Set_Scope_Depth_Value (S, Uint_0);
5935 elsif Is_Child_Unit (S) then
5936 Set_Scope_Depth_Value (S, Uint_1);
5938 elsif not Is_Record_Type (Current_Scope) then
5939 if Ekind (S) = E_Loop then
5940 Set_Scope_Depth_Value (S, Scope_Depth (Current_Scope));
5942 Set_Scope_Depth_Value (S, Scope_Depth (Current_Scope) + 1);
5947 Scope_Stack.Increment_Last;
5950 SST : Scope_Stack_Entry renames Scope_Stack.Table (Scope_Stack.Last);
5954 SST.Save_Scope_Suppress := Scope_Suppress;
5955 SST.Save_Local_Suppress_Stack_Top := Local_Suppress_Stack_Top;
5957 if Scope_Stack.Last > Scope_Stack.First then
5958 SST.Component_Alignment_Default := Scope_Stack.Table
5959 (Scope_Stack.Last - 1).
5960 Component_Alignment_Default;
5963 SST.Last_Subprogram_Name := null;
5964 SST.Is_Transient := False;
5965 SST.Node_To_Be_Wrapped := Empty;
5966 SST.Pending_Freeze_Actions := No_List;
5967 SST.Actions_To_Be_Wrapped_Before := No_List;
5968 SST.Actions_To_Be_Wrapped_After := No_List;
5969 SST.First_Use_Clause := Empty;
5970 SST.Is_Active_Stack_Base := False;
5971 SST.Previous_Visibility := False;
5974 if Debug_Flag_W then
5975 Write_Str ("--> new scope: ");
5976 Write_Name (Chars (Current_Scope));
5977 Write_Str (", Id=");
5978 Write_Int (Int (Current_Scope));
5979 Write_Str (", Depth=");
5980 Write_Int (Int (Scope_Stack.Last));
5984 -- Deal with copying flags from the previous scope to this one. This
5985 -- is not necessary if either scope is standard, or if the new scope
5988 if S /= Standard_Standard
5989 and then Scope (S) /= Standard_Standard
5990 and then not Is_Child_Unit (S)
5994 if Nkind (E) not in N_Entity then
5998 -- Copy categorization flags from Scope (S) to S, this is not done
5999 -- when Scope (S) is Standard_Standard since propagation is from
6000 -- library unit entity inwards. Copy other relevant attributes as
6001 -- well (Discard_Names in particular).
6003 -- We only propagate inwards for library level entities,
6004 -- inner level subprograms do not inherit the categorization.
6006 if Is_Library_Level_Entity (S) then
6007 Set_Is_Preelaborated (S, Is_Preelaborated (E));
6008 Set_Is_Shared_Passive (S, Is_Shared_Passive (E));
6009 Set_Discard_Names (S, Discard_Names (E));
6010 Set_Suppress_Value_Tracking_On_Call
6011 (S, Suppress_Value_Tracking_On_Call (E));
6012 Set_Categorization_From_Scope (E => S, Scop => E);
6017 ---------------------
6018 -- Premature_Usage --
6019 ---------------------
6021 procedure Premature_Usage (N : Node_Id) is
6022 Kind : constant Node_Kind := Nkind (Parent (Entity (N)));
6023 E : Entity_Id := Entity (N);
6026 -- Within an instance, the analysis of the actual for a formal object
6027 -- does not see the name of the object itself. This is significant only
6028 -- if the object is an aggregate, where its analysis does not do any
6029 -- name resolution on component associations. (see 4717-008). In such a
6030 -- case, look for the visible homonym on the chain.
6033 and then Present (Homonym (E))
6038 and then not In_Open_Scopes (Scope (E))
6045 Set_Etype (N, Etype (E));
6050 if Kind = N_Component_Declaration then
6052 ("component&! cannot be used before end of record declaration", N);
6054 elsif Kind = N_Parameter_Specification then
6056 ("formal parameter&! cannot be used before end of specification",
6059 elsif Kind = N_Discriminant_Specification then
6061 ("discriminant&! cannot be used before end of discriminant part",
6064 elsif Kind = N_Procedure_Specification
6065 or else Kind = N_Function_Specification
6068 ("subprogram&! cannot be used before end of its declaration",
6072 ("object& cannot be used before end of its declaration!", N);
6074 end Premature_Usage;
6076 ------------------------
6077 -- Present_System_Aux --
6078 ------------------------
6080 function Present_System_Aux (N : Node_Id := Empty) return Boolean is
6082 Aux_Name : Unit_Name_Type;
6083 Unum : Unit_Number_Type;
6088 function Find_System (C_Unit : Node_Id) return Entity_Id;
6089 -- Scan context clause of compilation unit to find with_clause
6096 function Find_System (C_Unit : Node_Id) return Entity_Id is
6097 With_Clause : Node_Id;
6100 With_Clause := First (Context_Items (C_Unit));
6101 while Present (With_Clause) loop
6102 if (Nkind (With_Clause) = N_With_Clause
6103 and then Chars (Name (With_Clause)) = Name_System)
6104 and then Comes_From_Source (With_Clause)
6115 -- Start of processing for Present_System_Aux
6118 -- The child unit may have been loaded and analyzed already
6120 if Present (System_Aux_Id) then
6123 -- If no previous pragma for System.Aux, nothing to load
6125 elsif No (System_Extend_Unit) then
6128 -- Use the unit name given in the pragma to retrieve the unit.
6129 -- Verify that System itself appears in the context clause of the
6130 -- current compilation. If System is not present, an error will
6131 -- have been reported already.
6134 With_Sys := Find_System (Cunit (Current_Sem_Unit));
6136 The_Unit := Unit (Cunit (Current_Sem_Unit));
6139 and then (Nkind (The_Unit) = N_Package_Body
6140 or else (Nkind (The_Unit) = N_Subprogram_Body
6141 and then not Acts_As_Spec (Cunit (Current_Sem_Unit))))
6143 With_Sys := Find_System (Library_Unit (Cunit (Current_Sem_Unit)));
6147 and then Present (N)
6149 -- If we are compiling a subunit, we need to examine its
6150 -- context as well (Current_Sem_Unit is the parent unit);
6152 The_Unit := Parent (N);
6154 while Nkind (The_Unit) /= N_Compilation_Unit loop
6155 The_Unit := Parent (The_Unit);
6158 if Nkind (Unit (The_Unit)) = N_Subunit then
6159 With_Sys := Find_System (The_Unit);
6163 if No (With_Sys) then
6167 Loc := Sloc (With_Sys);
6168 Get_Name_String (Chars (Expression (System_Extend_Unit)));
6169 Name_Buffer (8 .. Name_Len + 7) := Name_Buffer (1 .. Name_Len);
6170 Name_Buffer (1 .. 7) := "system.";
6171 Name_Buffer (Name_Len + 8) := '%';
6172 Name_Buffer (Name_Len + 9) := 's';
6173 Name_Len := Name_Len + 9;
6174 Aux_Name := Name_Find;
6178 (Load_Name => Aux_Name,
6181 Error_Node => With_Sys);
6183 if Unum /= No_Unit then
6184 Semantics (Cunit (Unum));
6186 Defining_Entity (Specification (Unit (Cunit (Unum))));
6189 Make_With_Clause (Loc,
6191 Make_Expanded_Name (Loc,
6192 Chars => Chars (System_Aux_Id),
6193 Prefix => New_Reference_To (Scope (System_Aux_Id), Loc),
6194 Selector_Name => New_Reference_To (System_Aux_Id, Loc)));
6196 Set_Entity (Name (Withn), System_Aux_Id);
6198 Set_Library_Unit (Withn, Cunit (Unum));
6199 Set_Corresponding_Spec (Withn, System_Aux_Id);
6200 Set_First_Name (Withn, True);
6201 Set_Implicit_With (Withn, True);
6203 Insert_After (With_Sys, Withn);
6204 Mark_Rewrite_Insertion (Withn);
6205 Set_Context_Installed (Withn);
6209 -- Here if unit load failed
6212 Error_Msg_Name_1 := Name_System;
6213 Error_Msg_Name_2 := Chars (Expression (System_Extend_Unit));
6215 ("extension package `%.%` does not exist",
6216 Opt.System_Extend_Unit);
6220 end Present_System_Aux;
6222 -------------------------
6223 -- Restore_Scope_Stack --
6224 -------------------------
6226 procedure Restore_Scope_Stack (Handle_Use : Boolean := True) is
6229 Comp_Unit : Node_Id;
6230 In_Child : Boolean := False;
6231 Full_Vis : Boolean := True;
6232 SS_Last : constant Int := Scope_Stack.Last;
6235 -- Restore visibility of previous scope stack, if any
6237 for J in reverse 0 .. Scope_Stack.Last loop
6238 exit when Scope_Stack.Table (J).Entity = Standard_Standard
6239 or else No (Scope_Stack.Table (J).Entity);
6241 S := Scope_Stack.Table (J).Entity;
6243 if not Is_Hidden_Open_Scope (S) then
6245 -- If the parent scope is hidden, its entities are hidden as
6246 -- well, unless the entity is the instantiation currently
6249 if not Is_Hidden_Open_Scope (Scope (S))
6250 or else not Analyzed (Parent (S))
6251 or else Scope (S) = Standard_Standard
6253 Set_Is_Immediately_Visible (S, True);
6256 E := First_Entity (S);
6257 while Present (E) loop
6258 if Is_Child_Unit (E) then
6259 Set_Is_Immediately_Visible (E,
6260 Is_Visible_Child_Unit (E) or else In_Open_Scopes (E));
6262 Set_Is_Immediately_Visible (E, True);
6267 if not Full_Vis then
6268 exit when E = First_Private_Entity (S);
6272 -- The visibility of child units (siblings of current compilation)
6273 -- must be restored in any case. Their declarations may appear
6274 -- after the private part of the parent.
6276 if not Full_Vis then
6277 while Present (E) loop
6278 if Is_Child_Unit (E) then
6279 Set_Is_Immediately_Visible (E,
6280 Is_Visible_Child_Unit (E) or else In_Open_Scopes (E));
6288 if Is_Child_Unit (S)
6289 and not In_Child -- check only for current unit
6293 -- Restore visibility of parents according to whether the child
6294 -- is private and whether we are in its visible part.
6296 Comp_Unit := Parent (Unit_Declaration_Node (S));
6298 if Nkind (Comp_Unit) = N_Compilation_Unit
6299 and then Private_Present (Comp_Unit)
6303 elsif (Ekind (S) = E_Package
6304 or else Ekind (S) = E_Generic_Package)
6305 and then (In_Private_Part (S)
6306 or else In_Package_Body (S))
6310 elsif (Ekind (S) = E_Procedure
6311 or else Ekind (S) = E_Function)
6312 and then Has_Completion (S)
6323 if SS_Last >= Scope_Stack.First
6324 and then Scope_Stack.Table (SS_Last).Entity /= Standard_Standard
6327 Install_Use_Clauses (Scope_Stack.Table (SS_Last).First_Use_Clause);
6329 end Restore_Scope_Stack;
6331 ----------------------
6332 -- Save_Scope_Stack --
6333 ----------------------
6335 procedure Save_Scope_Stack (Handle_Use : Boolean := True) is
6338 SS_Last : constant Int := Scope_Stack.Last;
6341 if SS_Last >= Scope_Stack.First
6342 and then Scope_Stack.Table (SS_Last).Entity /= Standard_Standard
6345 End_Use_Clauses (Scope_Stack.Table (SS_Last).First_Use_Clause);
6348 -- If the call is from within a compilation unit, as when called from
6349 -- Rtsfind, make current entries in scope stack invisible while we
6350 -- analyze the new unit.
6352 for J in reverse 0 .. SS_Last loop
6353 exit when Scope_Stack.Table (J).Entity = Standard_Standard
6354 or else No (Scope_Stack.Table (J).Entity);
6356 S := Scope_Stack.Table (J).Entity;
6357 Set_Is_Immediately_Visible (S, False);
6359 E := First_Entity (S);
6360 while Present (E) loop
6361 Set_Is_Immediately_Visible (E, False);
6367 end Save_Scope_Stack;
6373 procedure Set_Use (L : List_Id) is
6375 Pack_Name : Node_Id;
6382 while Present (Decl) loop
6383 if Nkind (Decl) = N_Use_Package_Clause then
6384 Chain_Use_Clause (Decl);
6386 Pack_Name := First (Names (Decl));
6387 while Present (Pack_Name) loop
6388 Pack := Entity (Pack_Name);
6390 if Ekind (Pack) = E_Package
6391 and then Applicable_Use (Pack_Name)
6393 Use_One_Package (Pack, Decl);
6399 elsif Nkind (Decl) = N_Use_Type_Clause then
6400 Chain_Use_Clause (Decl);
6402 Id := First (Subtype_Marks (Decl));
6403 while Present (Id) loop
6404 if Entity (Id) /= Any_Type then
6417 ---------------------
6418 -- Use_One_Package --
6419 ---------------------
6421 procedure Use_One_Package (P : Entity_Id; N : Node_Id) is
6424 Current_Instance : Entity_Id := Empty;
6426 Private_With_OK : Boolean := False;
6429 if Ekind (P) /= E_Package then
6434 Set_Current_Use_Clause (P, N);
6436 -- Ada 2005 (AI-50217): Check restriction
6438 if From_With_Type (P) then
6439 Error_Msg_N ("limited withed package cannot appear in use clause", N);
6442 -- Find enclosing instance, if any
6445 Current_Instance := Current_Scope;
6446 while not Is_Generic_Instance (Current_Instance) loop
6447 Current_Instance := Scope (Current_Instance);
6450 if No (Hidden_By_Use_Clause (N)) then
6451 Set_Hidden_By_Use_Clause (N, New_Elmt_List);
6455 -- If unit is a package renaming, indicate that the renamed
6456 -- package is also in use (the flags on both entities must
6457 -- remain consistent, and a subsequent use of either of them
6458 -- should be recognized as redundant).
6460 if Present (Renamed_Object (P)) then
6461 Set_In_Use (Renamed_Object (P));
6462 Set_Current_Use_Clause (Renamed_Object (P), N);
6463 Real_P := Renamed_Object (P);
6468 -- Ada 2005 (AI-262): Check the use_clause of a private withed package
6469 -- found in the private part of a package specification
6471 if In_Private_Part (Current_Scope)
6472 and then Has_Private_With (P)
6473 and then Is_Child_Unit (Current_Scope)
6474 and then Is_Child_Unit (P)
6475 and then Is_Ancestor_Package (Scope (Current_Scope), P)
6477 Private_With_OK := True;
6480 -- Loop through entities in one package making them potentially
6483 Id := First_Entity (P);
6485 and then (Id /= First_Private_Entity (P)
6486 or else Private_With_OK) -- Ada 2005 (AI-262)
6488 Prev := Current_Entity (Id);
6489 while Present (Prev) loop
6490 if Is_Immediately_Visible (Prev)
6491 and then (not Is_Overloadable (Prev)
6492 or else not Is_Overloadable (Id)
6493 or else (Type_Conformant (Id, Prev)))
6495 if No (Current_Instance) then
6497 -- Potentially use-visible entity remains hidden
6499 goto Next_Usable_Entity;
6501 -- A use clause within an instance hides outer global entities,
6502 -- which are not used to resolve local entities in the
6503 -- instance. Note that the predefined entities in Standard
6504 -- could not have been hidden in the generic by a use clause,
6505 -- and therefore remain visible. Other compilation units whose
6506 -- entities appear in Standard must be hidden in an instance.
6508 -- To determine whether an entity is external to the instance
6509 -- we compare the scope depth of its scope with that of the
6510 -- current instance. However, a generic actual of a subprogram
6511 -- instance is declared in the wrapper package but will not be
6512 -- hidden by a use-visible entity.
6514 -- If Id is called Standard, the predefined package with the
6515 -- same name is in the homonym chain. It has to be ignored
6516 -- because it has no defined scope (being the only entity in
6517 -- the system with this mandated behavior).
6519 elsif not Is_Hidden (Id)
6520 and then Present (Scope (Prev))
6521 and then not Is_Wrapper_Package (Scope (Prev))
6522 and then Scope_Depth (Scope (Prev)) <
6523 Scope_Depth (Current_Instance)
6524 and then (Scope (Prev) /= Standard_Standard
6525 or else Sloc (Prev) > Standard_Location)
6527 Set_Is_Potentially_Use_Visible (Id);
6528 Set_Is_Immediately_Visible (Prev, False);
6529 Append_Elmt (Prev, Hidden_By_Use_Clause (N));
6532 -- A user-defined operator is not use-visible if the predefined
6533 -- operator for the type is immediately visible, which is the case
6534 -- if the type of the operand is in an open scope. This does not
6535 -- apply to user-defined operators that have operands of different
6536 -- types, because the predefined mixed mode operations (multiply
6537 -- and divide) apply to universal types and do not hide anything.
6539 elsif Ekind (Prev) = E_Operator
6540 and then Operator_Matches_Spec (Prev, Id)
6541 and then In_Open_Scopes
6542 (Scope (Base_Type (Etype (First_Formal (Id)))))
6543 and then (No (Next_Formal (First_Formal (Id)))
6544 or else Etype (First_Formal (Id))
6545 = Etype (Next_Formal (First_Formal (Id)))
6546 or else Chars (Prev) = Name_Op_Expon)
6548 goto Next_Usable_Entity;
6551 Prev := Homonym (Prev);
6554 -- On exit, we know entity is not hidden, unless it is private
6556 if not Is_Hidden (Id)
6557 and then ((not Is_Child_Unit (Id))
6558 or else Is_Visible_Child_Unit (Id))
6560 Set_Is_Potentially_Use_Visible (Id);
6562 if Is_Private_Type (Id)
6563 and then Present (Full_View (Id))
6565 Set_Is_Potentially_Use_Visible (Full_View (Id));
6569 <<Next_Usable_Entity>>
6573 -- Child units are also made use-visible by a use clause, but they may
6574 -- appear after all visible declarations in the parent entity list.
6576 while Present (Id) loop
6577 if Is_Child_Unit (Id)
6578 and then Is_Visible_Child_Unit (Id)
6580 Set_Is_Potentially_Use_Visible (Id);
6586 if Chars (Real_P) = Name_System
6587 and then Scope (Real_P) = Standard_Standard
6588 and then Present_System_Aux (N)
6590 Use_One_Package (System_Aux_Id, N);
6593 end Use_One_Package;
6599 procedure Use_One_Type (Id : Node_Id) is
6605 -- It is the type determined by the subtype mark (8.4(8)) whose
6606 -- operations become potentially use-visible.
6608 T := Base_Type (Entity (Id));
6613 or else Is_Potentially_Use_Visible (T)
6614 or else In_Use (Scope (T)));
6616 if In_Open_Scopes (Scope (T)) then
6619 elsif From_With_Type (T) then
6621 ("incomplete type from limited view "
6622 & "cannot appear in use clause", Id);
6624 -- If the subtype mark designates a subtype in a different package,
6625 -- we have to check that the parent type is visible, otherwise the
6626 -- use type clause is a noop. Not clear how to do that???
6628 elsif not Redundant_Use (Id) then
6630 Op_List := Collect_Primitive_Operations (T);
6632 Elmt := First_Elmt (Op_List);
6633 while Present (Elmt) loop
6634 if (Nkind (Node (Elmt)) = N_Defining_Operator_Symbol
6635 or else Chars (Node (Elmt)) in Any_Operator_Name)
6636 and then not Is_Hidden (Node (Elmt))
6638 Set_Is_Potentially_Use_Visible (Node (Elmt));
6650 procedure Write_Info is
6651 Id : Entity_Id := First_Entity (Current_Scope);
6654 -- No point in dumping standard entities
6656 if Current_Scope = Standard_Standard then
6660 Write_Str ("========================================================");
6662 Write_Str (" Defined Entities in ");
6663 Write_Name (Chars (Current_Scope));
6665 Write_Str ("========================================================");
6669 Write_Str ("-- none --");
6673 while Present (Id) loop
6674 Write_Entity_Info (Id, " ");
6679 if Scope (Current_Scope) = Standard_Standard then
6681 -- Print information on the current unit itself
6683 Write_Entity_Info (Current_Scope, " ");
6693 procedure Write_Scopes is
6696 for J in reverse 1 .. Scope_Stack.Last loop
6697 S := Scope_Stack.Table (J).Entity;
6698 Write_Int (Int (S));
6699 Write_Str (" === ");
6700 Write_Name (Chars (S));
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