1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2005, Free Software Foundation, Inc. --
11 -- GNAT is free software; you can redistribute it and/or modify it under --
12 -- terms of the GNU General Public License as published by the Free Soft- --
13 -- ware Foundation; either version 2, or (at your option) any later ver- --
14 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
15 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
16 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
17 -- for more details. You should have received a copy of the GNU General --
18 -- Public License distributed with GNAT; see file COPYING. If not, write --
19 -- to the Free Software Foundation, 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;
37 with Lib.Load; use Lib.Load;
38 with Lib.Xref; use Lib.Xref;
39 with Namet; use Namet;
40 with Nlists; use Nlists;
41 with Nmake; use Nmake;
43 with Output; use Output;
44 with Restrict; use Restrict;
45 with Rident; use Rident;
46 with Rtsfind; use Rtsfind;
48 with Sem_Cat; use Sem_Cat;
49 with Sem_Ch3; use Sem_Ch3;
50 with Sem_Ch4; use Sem_Ch4;
51 with Sem_Ch6; use Sem_Ch6;
52 with Sem_Ch12; use Sem_Ch12;
53 with Sem_Disp; use Sem_Disp;
54 with Sem_Dist; use Sem_Dist;
55 with Sem_Res; use Sem_Res;
56 with Sem_Util; use Sem_Util;
57 with Sem_Type; use Sem_Type;
58 with Stand; use Stand;
59 with Sinfo; use Sinfo;
60 with Sinfo.CN; use Sinfo.CN;
61 with Snames; use Snames;
62 with Style; use Style;
64 with Tbuild; use Tbuild;
65 with Uintp; use Uintp;
67 with GNAT.Spelling_Checker; use GNAT.Spelling_Checker;
69 package body Sem_Ch8 is
71 ------------------------------------
72 -- Visibility and Name Resolution --
73 ------------------------------------
75 -- This package handles name resolution and the collection of
76 -- interpretations for overloaded names, prior to overload resolution.
78 -- Name resolution is the process that establishes a mapping between source
79 -- identifiers and the entities they denote at each point in the program.
80 -- Each entity is represented by a defining occurrence. Each identifier
81 -- that denotes an entity points to the corresponding defining occurrence.
82 -- This is the entity of the applied occurrence. Each occurrence holds
83 -- an index into the names table, where source identifiers are stored.
85 -- Each entry in the names table for an identifier or designator uses the
86 -- Info pointer to hold a link to the currently visible entity that has
87 -- this name (see subprograms Get_Name_Entity_Id and Set_Name_Entity_Id
88 -- in package Sem_Util). The visibility is initialized at the beginning of
89 -- semantic processing to make entities in package Standard immediately
90 -- visible. The visibility table is used in a more subtle way when
91 -- compiling subunits (see below).
93 -- Entities that have the same name (i.e. homonyms) are chained. In the
94 -- case of overloaded entities, this chain holds all the possible meanings
95 -- of a given identifier. The process of overload resolution uses type
96 -- information to select from this chain the unique meaning of a given
99 -- Entities are also chained in their scope, through the Next_Entity link.
100 -- As a consequence, the name space is organized as a sparse matrix, where
101 -- each row corresponds to a scope, and each column to a source identifier.
102 -- Open scopes, that is to say scopes currently being compiled, have their
103 -- corresponding rows of entities in order, innermost scope first.
105 -- The scopes of packages that are mentioned in context clauses appear in
106 -- no particular order, interspersed among open scopes. This is because
107 -- in the course of analyzing the context of a compilation, a package
108 -- declaration is first an open scope, and subsequently an element of the
109 -- context. If subunits or child units are present, a parent unit may
110 -- appear under various guises at various times in the compilation.
112 -- When the compilation of the innermost scope is complete, the entities
113 -- defined therein are no longer visible. If the scope is not a package
114 -- declaration, these entities are never visible subsequently, and can be
115 -- removed from visibility chains. If the scope is a package declaration,
116 -- its visible declarations may still be accessible. Therefore the entities
117 -- defined in such a scope are left on the visibility chains, and only
118 -- their visibility (immediately visibility or potential use-visibility)
121 -- The ordering of homonyms on their chain does not necessarily follow
122 -- the order of their corresponding scopes on the scope stack. For
123 -- example, if package P and the enclosing scope both contain entities
124 -- named E, then when compiling the package body the chain for E will
125 -- hold the global entity first, and the local one (corresponding to
126 -- the current inner scope) next. As a result, name resolution routines
127 -- do not assume any relative ordering of the homonym chains, either
128 -- for scope nesting or to order of appearance of context clauses.
130 -- When compiling a child unit, entities in the parent scope are always
131 -- immediately visible. When compiling the body of a child unit, private
132 -- entities in the parent must also be made immediately visible. There
133 -- are separate routines to make the visible and private declarations
134 -- visible at various times (see package Sem_Ch7).
136 -- +--------+ +-----+
137 -- | In use |-------->| EU1 |-------------------------->
138 -- +--------+ +-----+
140 -- +--------+ +-----+ +-----+
141 -- | Stand. |---------------->| ES1 |--------------->| ES2 |--->
142 -- +--------+ +-----+ +-----+
144 -- +---------+ | +-----+
145 -- | with'ed |------------------------------>| EW2 |--->
146 -- +---------+ | +-----+
148 -- +--------+ +-----+ +-----+
149 -- | Scope2 |---------------->| E12 |--------------->| E22 |--->
150 -- +--------+ +-----+ +-----+
152 -- +--------+ +-----+ +-----+
153 -- | Scope1 |---------------->| E11 |--------------->| E12 |--->
154 -- +--------+ +-----+ +-----+
158 -- | | with'ed |----------------------------------------->
162 -- (innermost first) | |
163 -- +----------------------------+
164 -- Names table => | Id1 | | | | Id2 |
165 -- +----------------------------+
167 -- Name resolution must deal with several syntactic forms: simple names,
168 -- qualified names, indexed names, and various forms of calls.
170 -- Each identifier points to an entry in the names table. The resolution
171 -- of a simple name consists in traversing the homonym chain, starting
172 -- from the names table. If an entry is immediately visible, it is the one
173 -- designated by the identifier. If only potentially use-visible entities
174 -- are on the chain, we must verify that they do not hide each other. If
175 -- the entity we find is overloadable, we collect all other overloadable
176 -- entities on the chain as long as they are not hidden.
178 -- To resolve expanded names, we must find the entity at the intersection
179 -- of the entity chain for the scope (the prefix) and the homonym chain
180 -- for the selector. In general, homonym chains will be much shorter than
181 -- entity chains, so it is preferable to start from the names table as
182 -- well. If the entity found is overloadable, we must collect all other
183 -- interpretations that are defined in the scope denoted by the prefix.
185 -- For records, protected types, and tasks, their local entities are
186 -- removed from visibility chains on exit from the corresponding scope.
187 -- From the outside, these entities are always accessed by selected
188 -- notation, and the entity chain for the record type, protected type,
189 -- etc. is traversed sequentially in order to find the designated entity.
191 -- The discriminants of a type and the operations of a protected type or
192 -- task are unchained on exit from the first view of the type, (such as
193 -- a private or incomplete type declaration, or a protected type speci-
194 -- fication) and re-chained when compiling the second view.
196 -- In the case of operators, we do not make operators on derived types
197 -- explicit. As a result, the notation P."+" may denote either a user-
198 -- defined function with name "+", or else an implicit declaration of the
199 -- operator "+" in package P. The resolution of expanded names always
200 -- tries to resolve an operator name as such an implicitly defined entity,
201 -- in addition to looking for explicit declarations.
203 -- All forms of names that denote entities (simple names, expanded names,
204 -- character literals in some cases) have a Entity attribute, which
205 -- identifies the entity denoted by the name.
207 ---------------------
208 -- The Scope Stack --
209 ---------------------
211 -- The Scope stack keeps track of the scopes currently been compiled.
212 -- Every entity that contains declarations (including records) is placed
213 -- on the scope stack while it is being processed, and removed at the end.
214 -- Whenever a non-package scope is exited, the entities defined therein
215 -- are removed from the visibility table, so that entities in outer scopes
216 -- become visible (see previous description). On entry to Sem, the scope
217 -- stack only contains the package Standard. As usual, subunits complicate
218 -- this picture ever so slightly.
220 -- The Rtsfind mechanism can force a call to Semantics while another
221 -- compilation is in progress. The unit retrieved by Rtsfind must be
222 -- compiled in its own context, and has no access to the visibility of
223 -- the unit currently being compiled. The procedures Save_Scope_Stack and
224 -- Restore_Scope_Stack make entities in current open scopes invisible
225 -- before compiling the retrieved unit, and restore the compilation
226 -- environment afterwards.
228 ------------------------
229 -- Compiling subunits --
230 ------------------------
232 -- Subunits must be compiled in the environment of the corresponding
233 -- stub, that is to say with the same visibility into the parent (and its
234 -- context) that is available at the point of the stub declaration, but
235 -- with the additional visibility provided by the context clause of the
236 -- subunit itself. As a result, compilation of a subunit forces compilation
237 -- of the parent (see description in lib-). At the point of the stub
238 -- declaration, Analyze is called recursively to compile the proper body
239 -- of the subunit, but without reinitializing the names table, nor the
240 -- scope stack (i.e. standard is not pushed on the stack). In this fashion
241 -- the context of the subunit is added to the context of the parent, and
242 -- the subunit is compiled in the correct environment. Note that in the
243 -- course of processing the context of a subunit, Standard will appear
244 -- twice on the scope stack: once for the parent of the subunit, and
245 -- once for the unit in the context clause being compiled. However, the
246 -- two sets of entities are not linked by homonym chains, so that the
247 -- compilation of any context unit happens in a fresh visibility
250 -------------------------------
251 -- Processing of USE Clauses --
252 -------------------------------
254 -- Every defining occurrence has a flag indicating if it is potentially use
255 -- visible. Resolution of simple names examines this flag. The processing
256 -- of use clauses consists in setting this flag on all visible entities
257 -- defined in the corresponding package. On exit from the scope of the use
258 -- clause, the corresponding flag must be reset. However, a package may
259 -- appear in several nested use clauses (pathological but legal, alas!)
260 -- which forces us to use a slightly more involved scheme:
262 -- a) The defining occurrence for a package holds a flag -In_Use- to
263 -- indicate that it is currently in the scope of a use clause. If a
264 -- redundant use clause is encountered, then the corresponding occurrence
265 -- of the package name is flagged -Redundant_Use-.
267 -- b) On exit from a scope, the use clauses in its declarative part are
268 -- scanned. The visibility flag is reset in all entities declared in
269 -- package named in a use clause, as long as the package is not flagged
270 -- as being in a redundant use clause (in which case the outer use
271 -- clause is still in effect, and the direct visibility of its entities
272 -- must be retained).
274 -- Note that entities are not removed from their homonym chains on exit
275 -- from the package specification. A subsequent use clause does not need
276 -- to rechain the visible entities, but only to establish their direct
279 -----------------------------------
280 -- Handling private declarations --
281 -----------------------------------
283 -- The principle that each entity has a single defining occurrence clashes
284 -- with the presence of two separate definitions for private types: the
285 -- first is the private type declaration, and second is the full type
286 -- declaration. It is important that all references to the type point to
287 -- the same defining occurrence, namely the first one. To enforce the two
288 -- separate views of the entity, the corresponding information is swapped
289 -- between the two declarations. Outside of the package, the defining
290 -- occurrence only contains the private declaration information, while in
291 -- the private part and the body of the package the defining occurrence
292 -- contains the full declaration. To simplify the swap, the defining
293 -- occurrence that currently holds the private declaration points to the
294 -- full declaration. During semantic processing the defining occurrence
295 -- also points to a list of private dependents, that is to say access
296 -- types or composite types whose designated types or component types are
297 -- subtypes or derived types of the private type in question. After the
298 -- full declaration has been seen, the private dependents are updated to
299 -- indicate that they have full definitions.
301 ------------------------------------
302 -- Handling of Undefined Messages --
303 ------------------------------------
305 -- In normal mode, only the first use of an undefined identifier generates
306 -- a message. The table Urefs is used to record error messages that have
307 -- been issued so that second and subsequent ones do not generate further
308 -- messages. However, the second reference causes text to be added to the
309 -- original undefined message noting "(more references follow)". The
310 -- full error list option (-gnatf) forces messages to be generated for
311 -- every reference and disconnects the use of this table.
313 type Uref_Entry is record
315 -- Node for identifier for which original message was posted. The
316 -- Chars field of this identifier is used to detect later references
317 -- to the same identifier.
320 -- Records error message Id of original undefined message. Reset to
321 -- No_Error_Msg after the second occurrence, where it is used to add
322 -- text to the original message as described above.
325 -- Set if the message is not visible rather than undefined
328 -- Records location of error message. Used to make sure that we do
329 -- not consider a, b : undefined as two separate instances, which
330 -- would otherwise happen, since the parser converts this sequence
331 -- to a : undefined; b : undefined.
335 package Urefs is new Table.Table (
336 Table_Component_Type => Uref_Entry,
337 Table_Index_Type => Nat,
338 Table_Low_Bound => 1,
340 Table_Increment => 100,
341 Table_Name => "Urefs");
343 Candidate_Renaming : Entity_Id;
344 -- Holds a candidate interpretation that appears in a subprogram renaming
345 -- declaration and does not match the given specification, but matches at
346 -- least on the first formal. Allows better error message when given
347 -- specification omits defaulted parameters, a common error.
349 -----------------------
350 -- Local Subprograms --
351 -----------------------
353 procedure Analyze_Generic_Renaming
356 -- Common processing for all three kinds of generic renaming declarations.
357 -- Enter new name and indicate that it renames the generic unit.
359 procedure Analyze_Renamed_Character
363 -- Renamed entity is given by a character literal, which must belong
364 -- to the return type of the new entity. Is_Body indicates whether the
365 -- declaration is a renaming_as_body. If the original declaration has
366 -- already been frozen (because of an intervening body, e.g.) the body of
367 -- the function must be built now. The same applies to the following
368 -- various renaming procedures.
370 procedure Analyze_Renamed_Dereference
374 -- Renamed entity is given by an explicit dereference. Prefix must be a
375 -- conformant access_to_subprogram type.
377 procedure Analyze_Renamed_Entry
381 -- If the renamed entity in a subprogram renaming is an entry or protected
382 -- subprogram, build a body for the new entity whose only statement is a
383 -- call to the renamed entity.
385 procedure Analyze_Renamed_Family_Member
389 -- Used when the renamed entity is an indexed component. The prefix must
390 -- denote an entry family.
392 function Applicable_Use (Pack_Name : Node_Id) return Boolean;
393 -- Common code to Use_One_Package and Set_Use, to determine whether
394 -- use clause must be processed. Pack_Name is an entity name that
395 -- references the package in question.
397 procedure Attribute_Renaming (N : Node_Id);
398 -- Analyze renaming of attribute as function. The renaming declaration N
399 -- is rewritten as a function body that returns the attribute reference
400 -- applied to the formals of the function.
402 procedure Check_Frozen_Renaming (N : Node_Id; Subp : Entity_Id);
403 -- A renaming_as_body may occur after the entity of the original decla-
404 -- ration has been frozen. In that case, the body of the new entity must
405 -- be built now, because the usual mechanism of building the renamed
406 -- body at the point of freezing will not work. Subp is the subprogram
407 -- for which N provides the Renaming_As_Body.
409 procedure Check_In_Previous_With_Clause
412 -- N is a use_package clause and Nam the package name, or N is a use_type
413 -- clause and Nam is the prefix of the type name. In either case, verify
414 -- that the package is visible at that point in the context: either it
415 -- appears in a previous with_clause, or because it is a fully qualified
416 -- name and the root ancestor appears in a previous with_clause.
418 procedure Check_Library_Unit_Renaming (N : Node_Id; Old_E : Entity_Id);
419 -- Verify that the entity in a renaming declaration that is a library unit
420 -- is itself a library unit and not a nested unit or subunit. Also check
421 -- that if the renaming is a child unit of a generic parent, then the
422 -- renamed unit must also be a child unit of that parent. Finally, verify
423 -- that a renamed generic unit is not an implicit child declared within
424 -- an instance of the parent.
426 procedure Chain_Use_Clause (N : Node_Id);
427 -- Chain use clause onto list of uses clauses headed by First_Use_Clause
428 -- in the top scope table entry.
430 function Has_Implicit_Character_Literal (N : Node_Id) return Boolean;
431 -- Find a type derived from Character or Wide_Character in the prefix of N.
432 -- Used to resolved qualified names whose selector is a character literal.
434 function Has_Private_With (E : Entity_Id) return Boolean;
435 -- Ada 2005 (AI-262): Determines if the current compilation unit has a
438 procedure Find_Expanded_Name (N : Node_Id);
439 -- Selected component is known to be expanded name. Verify legality
440 -- of selector given the scope denoted by prefix.
442 function Find_Renamed_Entity
446 Is_Actual : Boolean := False) return Entity_Id;
447 -- Find the renamed entity that corresponds to the given parameter profile
448 -- in a subprogram renaming declaration. The renamed entity may be an
449 -- operator, a subprogram, an entry, or a protected operation. Is_Actual
450 -- indicates that the renaming is the one generated for an actual subpro-
451 -- gram in an instance, for which special visibility checks apply.
453 function Has_Implicit_Operator (N : Node_Id) return Boolean;
454 -- N is an expanded name whose selector is an operator name (eg P."+").
455 -- A declarative part contains an implicit declaration of an operator
456 -- if it has a declaration of a type to which one of the predefined
457 -- operators apply. The existence of this routine is an artifact of
458 -- our implementation: a more straightforward but more space-consuming
459 -- choice would be to make all inherited operators explicit in the
462 procedure Inherit_Renamed_Profile (New_S : Entity_Id; Old_S : Entity_Id);
463 -- A subprogram defined by a renaming declaration inherits the parameter
464 -- profile of the renamed entity. The subtypes given in the subprogram
465 -- specification are discarded and replaced with those of the renamed
466 -- subprogram, which are then used to recheck the default values.
468 function Is_Appropriate_For_Record (T : Entity_Id) return Boolean;
469 -- Prefix is appropriate for record if it is of a record type, or
470 -- an access to such.
472 function Is_Appropriate_For_Entry_Prefix (T : Entity_Id) return Boolean;
473 -- True if it is of a task type, a protected type, or else an access
474 -- to one of these types.
476 procedure Premature_Usage (N : Node_Id);
477 -- Diagnose usage of an entity before it is visible
479 procedure Use_One_Package (P : Entity_Id; N : Node_Id);
480 -- Make visible entities declared in package P potentially use-visible
481 -- in the current context. Also used in the analysis of subunits, when
482 -- re-installing use clauses of parent units. N is the use_clause that
483 -- names P (and possibly other packages).
485 procedure Use_One_Type (Id : Node_Id);
486 -- Id is the subtype mark from a use type clause. This procedure makes
487 -- the primitive operators of the type potentially use-visible.
489 procedure Write_Info;
490 -- Write debugging information on entities declared in current scope
492 procedure Write_Scopes;
493 pragma Warnings (Off, Write_Scopes);
494 -- Debugging information: dump all entities on scope stack
496 --------------------------------
497 -- Analyze_Exception_Renaming --
498 --------------------------------
500 -- The language only allows a single identifier, but the tree holds
501 -- an identifier list. The parser has already issued an error message
502 -- if there is more than one element in the list.
504 procedure Analyze_Exception_Renaming (N : Node_Id) is
505 Id : constant Node_Id := Defining_Identifier (N);
506 Nam : constant Node_Id := Name (N);
512 Set_Ekind (Id, E_Exception);
513 Set_Exception_Code (Id, Uint_0);
514 Set_Etype (Id, Standard_Exception_Type);
515 Set_Is_Pure (Id, Is_Pure (Current_Scope));
517 if not Is_Entity_Name (Nam) or else
518 Ekind (Entity (Nam)) /= E_Exception
520 Error_Msg_N ("invalid exception name in renaming", Nam);
522 if Present (Renamed_Object (Entity (Nam))) then
523 Set_Renamed_Object (Id, Renamed_Object (Entity (Nam)));
525 Set_Renamed_Object (Id, Entity (Nam));
528 end Analyze_Exception_Renaming;
530 ---------------------------
531 -- Analyze_Expanded_Name --
532 ---------------------------
534 procedure Analyze_Expanded_Name (N : Node_Id) is
536 -- If the entity pointer is already set, this is an internal node, or
537 -- a node that is analyzed more than once, after a tree modification.
538 -- In such a case there is no resolution to perform, just set the type.
539 -- For completeness, analyze prefix as well.
541 if Present (Entity (N)) then
542 if Is_Type (Entity (N)) then
543 Set_Etype (N, Entity (N));
545 Set_Etype (N, Etype (Entity (N)));
548 Analyze (Prefix (N));
551 Find_Expanded_Name (N);
553 end Analyze_Expanded_Name;
555 ---------------------------------------
556 -- Analyze_Generic_Function_Renaming --
557 ---------------------------------------
559 procedure Analyze_Generic_Function_Renaming (N : Node_Id) is
561 Analyze_Generic_Renaming (N, E_Generic_Function);
562 end Analyze_Generic_Function_Renaming;
564 --------------------------------------
565 -- Analyze_Generic_Package_Renaming --
566 --------------------------------------
568 procedure Analyze_Generic_Package_Renaming (N : Node_Id) is
570 -- Apply the Text_IO Kludge here, since we may be renaming
571 -- one of the subpackages of Text_IO, then join common routine.
573 Text_IO_Kludge (Name (N));
575 Analyze_Generic_Renaming (N, E_Generic_Package);
576 end Analyze_Generic_Package_Renaming;
578 ----------------------------------------
579 -- Analyze_Generic_Procedure_Renaming --
580 ----------------------------------------
582 procedure Analyze_Generic_Procedure_Renaming (N : Node_Id) is
584 Analyze_Generic_Renaming (N, E_Generic_Procedure);
585 end Analyze_Generic_Procedure_Renaming;
587 ------------------------------
588 -- Analyze_Generic_Renaming --
589 ------------------------------
591 procedure Analyze_Generic_Renaming
595 New_P : constant Entity_Id := Defining_Entity (N);
597 Inst : Boolean := False; -- prevent junk warning
600 if Name (N) = Error then
604 Generate_Definition (New_P);
606 if Current_Scope /= Standard_Standard then
607 Set_Is_Pure (New_P, Is_Pure (Current_Scope));
610 if Nkind (Name (N)) = N_Selected_Component then
611 Check_Generic_Child_Unit (Name (N), Inst);
616 if not Is_Entity_Name (Name (N)) then
617 Error_Msg_N ("expect entity name in renaming declaration", Name (N));
620 Old_P := Entity (Name (N));
624 Set_Ekind (New_P, K);
626 if Etype (Old_P) = Any_Type then
629 elsif Ekind (Old_P) /= K then
630 Error_Msg_N ("invalid generic unit name", Name (N));
633 if Present (Renamed_Object (Old_P)) then
634 Set_Renamed_Object (New_P, Renamed_Object (Old_P));
636 Set_Renamed_Object (New_P, Old_P);
639 Set_Etype (New_P, Etype (Old_P));
640 Set_Has_Completion (New_P);
642 if In_Open_Scopes (Old_P) then
643 Error_Msg_N ("within its scope, generic denotes its instance", N);
646 Check_Library_Unit_Renaming (N, Old_P);
649 end Analyze_Generic_Renaming;
651 -----------------------------
652 -- Analyze_Object_Renaming --
653 -----------------------------
655 procedure Analyze_Object_Renaming (N : Node_Id) is
656 Id : constant Entity_Id := Defining_Identifier (N);
658 Nam : constant Node_Id := Name (N);
667 Set_Is_Pure (Id, Is_Pure (Current_Scope));
670 -- The renaming of a component that depends on a discriminant
671 -- requires an actual subtype, because in subsequent use of the object
672 -- Gigi will be unable to locate the actual bounds. This explicit step
673 -- is required when the renaming is generated in removing side effects
674 -- of an already-analyzed expression.
676 if Nkind (Nam) = N_Selected_Component
677 and then Analyzed (Nam)
680 Dec := Build_Actual_Subtype_Of_Component (Etype (Nam), Nam);
682 if Present (Dec) then
683 Insert_Action (N, Dec);
684 T := Defining_Identifier (Dec);
688 elsif Present (Subtype_Mark (N)) then
689 Find_Type (Subtype_Mark (N));
690 T := Entity (Subtype_Mark (N));
691 Analyze_And_Resolve (Nam, T);
693 -- Ada 2005 (AI-230/AI-254): Access renaming
695 else pragma Assert (Present (Access_Definition (N)));
696 T := Access_Definition
698 N => Access_Definition (N));
700 Analyze_And_Resolve (Nam, T);
702 -- Ada 2005 (AI-231): "In the case where the type is defined by an
703 -- access_definition, the renamed entity shall be of an access-to-
704 -- constant type if and only if the access_definition defines an
705 -- access-to-constant type" ARM 8.5.1(4)
707 if Constant_Present (Access_Definition (N))
708 and then not Is_Access_Constant (Etype (Nam))
710 Error_Msg_N ("(Ada 2005): the renamed object is not "
711 & "access-to-constant ('R'M 8.5.1(6))", N);
713 elsif Null_Exclusion_Present (Access_Definition (N)) then
714 Error_Msg_N ("(Ada 2005): null-excluding attribute ignored "
715 & "('R'M 8.5.1(6))?", N);
719 -- An object renaming requires an exact match of the type;
720 -- class-wide matching is not allowed.
722 if Is_Class_Wide_Type (T)
723 and then Base_Type (Etype (Nam)) /= Base_Type (T)
729 Set_Ekind (Id, E_Variable);
730 Init_Size_Align (Id);
732 if T = Any_Type or else Etype (Nam) = Any_Type then
735 -- Verify that the renamed entity is an object or a function call.
736 -- It may have been rewritten in several ways.
738 elsif Is_Object_Reference (Nam) then
739 if Comes_From_Source (N)
740 and then Is_Dependent_Component_Of_Mutable_Object (Nam)
743 ("illegal renaming of discriminant-dependent component", Nam);
748 -- A static function call may have been folded into a literal
750 elsif Nkind (Original_Node (Nam)) = N_Function_Call
752 -- When expansion is disabled, attribute reference is not
753 -- rewritten as function call. Otherwise it may be rewritten
754 -- as a conversion, so check original node.
756 or else (Nkind (Original_Node (Nam)) = N_Attribute_Reference
757 and then Is_Function_Attribute_Name
758 (Attribute_Name (Original_Node (Nam))))
760 -- Weird but legal, equivalent to renaming a function call
762 or else (Is_Entity_Name (Nam)
763 and then Ekind (Entity (Nam)) = E_Enumeration_Literal)
765 or else (Nkind (Nam) = N_Type_Conversion
766 and then Is_Tagged_Type (Entity (Subtype_Mark (Nam))))
771 if Nkind (Nam) = N_Type_Conversion then
773 ("renaming of conversion only allowed for tagged types", Nam);
776 Error_Msg_N ("expect object name in renaming", Nam);
782 if not Is_Variable (Nam) then
783 Set_Ekind (Id, E_Constant);
784 Set_Never_Set_In_Source (Id, True);
785 Set_Is_True_Constant (Id, True);
788 Set_Renamed_Object (Id, Nam);
789 end Analyze_Object_Renaming;
791 ------------------------------
792 -- Analyze_Package_Renaming --
793 ------------------------------
795 procedure Analyze_Package_Renaming (N : Node_Id) is
796 New_P : constant Entity_Id := Defining_Entity (N);
801 if Name (N) = Error then
805 -- Apply Text_IO kludge here, since we may be renaming one of
806 -- the children of Text_IO
808 Text_IO_Kludge (Name (N));
810 if Current_Scope /= Standard_Standard then
811 Set_Is_Pure (New_P, Is_Pure (Current_Scope));
816 if Is_Entity_Name (Name (N)) then
817 Old_P := Entity (Name (N));
822 if Etype (Old_P) = Any_Type then
824 ("expect package name in renaming", Name (N));
826 -- Ada 2005 (AI-50217): Limited withed packages can not be renamed
828 elsif Ekind (Old_P) = E_Package
829 and then From_With_Type (Old_P)
832 ("limited withed package cannot be renamed", Name (N));
834 elsif Ekind (Old_P) /= E_Package
835 and then not (Ekind (Old_P) = E_Generic_Package
836 and then In_Open_Scopes (Old_P))
838 if Ekind (Old_P) = E_Generic_Package then
840 ("generic package cannot be renamed as a package", Name (N));
842 Error_Msg_Sloc := Sloc (Old_P);
844 ("expect package name in renaming, found& declared#",
848 -- Set basic attributes to minimize cascaded errors
850 Set_Ekind (New_P, E_Package);
851 Set_Etype (New_P, Standard_Void_Type);
854 -- Entities in the old package are accessible through the
855 -- renaming entity. The simplest implementation is to have
856 -- both packages share the entity list.
858 Set_Ekind (New_P, E_Package);
859 Set_Etype (New_P, Standard_Void_Type);
861 if Present (Renamed_Object (Old_P)) then
862 Set_Renamed_Object (New_P, Renamed_Object (Old_P));
864 Set_Renamed_Object (New_P, Old_P);
867 Set_Has_Completion (New_P);
869 Set_First_Entity (New_P, First_Entity (Old_P));
870 Set_Last_Entity (New_P, Last_Entity (Old_P));
871 Set_First_Private_Entity (New_P, First_Private_Entity (Old_P));
872 Check_Library_Unit_Renaming (N, Old_P);
873 Generate_Reference (Old_P, Name (N));
875 -- If this is the renaming declaration of a package instantiation
876 -- within itself, it is the declaration that ends the list of actuals
877 -- for the instantiation. At this point, the subtypes that rename
878 -- the actuals are flagged as generic, to avoid spurious ambiguities
879 -- if the actuals for two distinct formals happen to coincide. If
880 -- the actual is a private type, the subtype has a private completion
881 -- that is flagged in the same fashion.
883 -- Resolution is identical to what is was in the original generic.
884 -- On exit from the generic instance, these are turned into regular
885 -- subtypes again, so they are compatible with types in their class.
887 if not Is_Generic_Instance (Old_P) then
890 Spec := Specification (Unit_Declaration_Node (Old_P));
893 if Nkind (Spec) = N_Package_Specification
894 and then Present (Generic_Parent (Spec))
895 and then Old_P = Current_Scope
896 and then Chars (New_P) = Chars (Generic_Parent (Spec))
899 E : Entity_Id := First_Entity (Old_P);
905 and then Nkind (Parent (E)) = N_Subtype_Declaration
907 Set_Is_Generic_Actual_Type (E);
909 if Is_Private_Type (E)
910 and then Present (Full_View (E))
912 Set_Is_Generic_Actual_Type (Full_View (E));
922 end Analyze_Package_Renaming;
924 -------------------------------
925 -- Analyze_Renamed_Character --
926 -------------------------------
928 procedure Analyze_Renamed_Character
933 C : constant Node_Id := Name (N);
936 if Ekind (New_S) = E_Function then
937 Resolve (C, Etype (New_S));
940 Check_Frozen_Renaming (N, New_S);
944 Error_Msg_N ("character literal can only be renamed as function", N);
946 end Analyze_Renamed_Character;
948 ---------------------------------
949 -- Analyze_Renamed_Dereference --
950 ---------------------------------
952 procedure Analyze_Renamed_Dereference
957 Nam : constant Node_Id := Name (N);
958 P : constant Node_Id := Prefix (Nam);
964 if not Is_Overloaded (P) then
965 if Ekind (Etype (Nam)) /= E_Subprogram_Type
966 or else not Type_Conformant (Etype (Nam), New_S) then
967 Error_Msg_N ("designated type does not match specification", P);
976 Get_First_Interp (Nam, Ind, It);
978 while Present (It.Nam) loop
980 if Ekind (It.Nam) = E_Subprogram_Type
981 and then Type_Conformant (It.Nam, New_S) then
983 if Typ /= Any_Id then
984 Error_Msg_N ("ambiguous renaming", P);
991 Get_Next_Interp (Ind, It);
994 if Typ = Any_Type then
995 Error_Msg_N ("designated type does not match specification", P);
1000 Check_Frozen_Renaming (N, New_S);
1004 end Analyze_Renamed_Dereference;
1006 ---------------------------
1007 -- Analyze_Renamed_Entry --
1008 ---------------------------
1010 procedure Analyze_Renamed_Entry
1015 Nam : constant Node_Id := Name (N);
1016 Sel : constant Node_Id := Selector_Name (Nam);
1020 if Entity (Sel) = Any_Id then
1022 -- Selector is undefined on prefix. Error emitted already
1024 Set_Has_Completion (New_S);
1028 -- Otherwise, find renamed entity, and build body of New_S as a call
1031 Old_S := Find_Renamed_Entity (N, Selector_Name (Nam), New_S);
1033 if Old_S = Any_Id then
1034 Error_Msg_N (" no subprogram or entry matches specification", N);
1037 Check_Subtype_Conformant (New_S, Old_S, N);
1038 Generate_Reference (New_S, Defining_Entity (N), 'b');
1039 Style.Check_Identifier (Defining_Entity (N), New_S);
1042 Inherit_Renamed_Profile (New_S, Old_S);
1045 Set_Convention (New_S, Convention (Old_S));
1046 Set_Has_Completion (New_S, Inside_A_Generic);
1049 Check_Frozen_Renaming (N, New_S);
1051 end Analyze_Renamed_Entry;
1053 -----------------------------------
1054 -- Analyze_Renamed_Family_Member --
1055 -----------------------------------
1057 procedure Analyze_Renamed_Family_Member
1062 Nam : constant Node_Id := Name (N);
1063 P : constant Node_Id := Prefix (Nam);
1067 if (Is_Entity_Name (P) and then Ekind (Entity (P)) = E_Entry_Family)
1068 or else (Nkind (P) = N_Selected_Component
1070 Ekind (Entity (Selector_Name (P))) = E_Entry_Family)
1072 if Is_Entity_Name (P) then
1073 Old_S := Entity (P);
1075 Old_S := Entity (Selector_Name (P));
1078 if not Entity_Matches_Spec (Old_S, New_S) then
1079 Error_Msg_N ("entry family does not match specification", N);
1082 Check_Subtype_Conformant (New_S, Old_S, N);
1083 Generate_Reference (New_S, Defining_Entity (N), 'b');
1084 Style.Check_Identifier (Defining_Entity (N), New_S);
1087 Error_Msg_N ("no entry family matches specification", N);
1090 Set_Has_Completion (New_S, Inside_A_Generic);
1093 Check_Frozen_Renaming (N, New_S);
1095 end Analyze_Renamed_Family_Member;
1097 ---------------------------------
1098 -- Analyze_Subprogram_Renaming --
1099 ---------------------------------
1101 procedure Analyze_Subprogram_Renaming (N : Node_Id) is
1102 Spec : constant Node_Id := Specification (N);
1103 Save_AV : constant Ada_Version_Type := Ada_Version;
1104 Save_AV_Exp : constant Ada_Version_Type := Ada_Version_Explicit;
1105 Nam : constant Node_Id := Name (N);
1107 Old_S : Entity_Id := Empty;
1108 Rename_Spec : Entity_Id;
1109 Formal_Spec : constant Node_Id := Corresponding_Formal_Spec (N);
1110 Is_Actual : constant Boolean := Present (Formal_Spec);
1111 Inst_Node : Node_Id := Empty;
1113 function Original_Subprogram (Subp : Entity_Id) return Entity_Id;
1114 -- Find renamed entity when the declaration is a renaming_as_body
1115 -- and the renamed entity may itself be a renaming_as_body. Used to
1116 -- enforce rule that a renaming_as_body is illegal if the declaration
1117 -- occurs before the subprogram it completes is frozen, and renaming
1118 -- indirectly renames the subprogram itself.(Defect Report 8652/0027).
1120 -------------------------
1121 -- Original_Subprogram --
1122 -------------------------
1124 function Original_Subprogram (Subp : Entity_Id) return Entity_Id is
1125 Orig_Decl : Node_Id;
1126 Orig_Subp : Entity_Id;
1129 -- First case: renamed entity is itself a renaming
1131 if Present (Alias (Subp)) then
1132 return Alias (Subp);
1135 Nkind (Unit_Declaration_Node (Subp)) = N_Subprogram_Declaration
1137 (Corresponding_Body (Unit_Declaration_Node (Subp)))
1139 -- Check if renamed entity is a renaming_as_body
1142 Unit_Declaration_Node
1143 (Corresponding_Body (Unit_Declaration_Node (Subp)));
1145 if Nkind (Orig_Decl) = N_Subprogram_Renaming_Declaration then
1146 Orig_Subp := Entity (Name (Orig_Decl));
1148 if Orig_Subp = Rename_Spec then
1150 -- Circularity detected
1155 return (Original_Subprogram (Orig_Subp));
1163 end Original_Subprogram;
1165 -- Start of processing for Analyze_Subprogram_Renaming
1168 -- We must test for the attribute renaming case before the Analyze
1169 -- call because otherwise Sem_Attr will complain that the attribute
1170 -- is missing an argument when it is analyzed.
1172 if Nkind (Nam) = N_Attribute_Reference then
1174 -- In the case of an abstract formal subprogram association,
1175 -- rewrite an actual given by a stream attribute as the name
1176 -- of the corresponding stream primitive of the type.
1178 if Is_Actual and then Is_Abstract (Formal_Spec) then
1180 Stream_Prim : Entity_Id;
1181 Prefix_Type : constant Entity_Id := Entity (Prefix (Nam));
1184 -- The class-wide forms of the stream attributes are not
1185 -- primitive dispatching operations (even though they
1186 -- internally dispatch to a stream attribute).
1188 if Is_Class_Wide_Type (Prefix_Type) then
1190 ("attribute must be a primitive dispatching operation",
1195 -- Retrieve the primitive subprogram associated with the
1196 -- attribute. This can only be a stream attribute, since
1197 -- those are the only ones that are dispatching (and the
1198 -- actual for an abstract formal subprogram must be a
1199 -- dispatching operation).
1201 case Attribute_Name (Nam) is
1204 Find_Prim_Op (Prefix_Type, TSS_Stream_Input);
1207 Find_Prim_Op (Prefix_Type, TSS_Stream_Output);
1210 Find_Prim_Op (Prefix_Type, TSS_Stream_Read);
1213 Find_Prim_Op (Prefix_Type, TSS_Stream_Write);
1216 ("attribute must be a primitive dispatching operation",
1221 -- Rewrite the attribute into the name of its corresponding
1222 -- primitive dispatching subprogram. We can then proceed with
1223 -- the usual processing for subprogram renamings.
1226 Prim_Name : constant Node_Id :=
1227 Make_Identifier (Sloc (Nam),
1228 Chars => Chars (Stream_Prim));
1230 Set_Entity (Prim_Name, Stream_Prim);
1231 Rewrite (Nam, Prim_Name);
1236 -- Normal processing for a renaming of an attribute
1239 Attribute_Renaming (N);
1244 -- Check whether this declaration corresponds to the instantiation
1245 -- of a formal subprogram.
1247 -- If this is an instantiation, the corresponding actual is frozen
1248 -- and error messages can be made more precise. If this is a default
1249 -- subprogram, the entity is already established in the generic, and
1250 -- is not retrieved by visibility. If it is a default with a box, the
1251 -- candidate interpretations, if any, have been collected when building
1252 -- the renaming declaration. If overloaded, the proper interpretation
1253 -- is determined in Find_Renamed_Entity. If the entity is an operator,
1254 -- Find_Renamed_Entity applies additional visibility checks.
1257 Inst_Node := Unit_Declaration_Node (Formal_Spec);
1259 if Is_Entity_Name (Nam)
1260 and then Present (Entity (Nam))
1261 and then not Comes_From_Source (Nam)
1262 and then not Is_Overloaded (Nam)
1264 Old_S := Entity (Nam);
1265 New_S := Analyze_Subprogram_Specification (Spec);
1269 if Ekind (Entity (Nam)) = E_Operator then
1273 if Box_Present (Inst_Node) then
1274 Old_S := Find_Renamed_Entity (N, Name (N), New_S, Is_Actual);
1276 -- If there is an immediately visible homonym of the operator
1277 -- and the declaration has a default, this is worth a warning
1278 -- because the user probably did not intend to get the pre-
1279 -- defined operator, visible in the generic declaration.
1280 -- To find if there is an intended candidate, analyze the
1281 -- renaming again in the current context.
1283 elsif Scope (Old_S) = Standard_Standard
1284 and then Present (Default_Name (Inst_Node))
1287 Decl : constant Node_Id := New_Copy_Tree (N);
1291 Set_Entity (Name (Decl), Empty);
1292 Analyze (Name (Decl));
1294 Find_Renamed_Entity (Decl, Name (Decl), New_S, True);
1297 and then In_Open_Scopes (Scope (Hidden))
1298 and then Is_Immediately_Visible (Hidden)
1299 and then Comes_From_Source (Hidden)
1300 and then Hidden /= Old_S
1302 Error_Msg_Sloc := Sloc (Hidden);
1303 Error_Msg_N ("?default subprogram is resolved " &
1304 "in the generic declaration " &
1305 "('R'M 12.6(17))", N);
1306 Error_Msg_NE ("\?and will not use & #", N, Hidden);
1314 New_S := Analyze_Subprogram_Specification (Spec);
1318 -- Renamed entity must be analyzed first, to avoid being hidden by
1319 -- new name (which might be the same in a generic instance).
1323 -- The renaming defines a new overloaded entity, which is analyzed
1324 -- like a subprogram declaration.
1326 New_S := Analyze_Subprogram_Specification (Spec);
1329 if Current_Scope /= Standard_Standard then
1330 Set_Is_Pure (New_S, Is_Pure (Current_Scope));
1333 Rename_Spec := Find_Corresponding_Spec (N);
1335 if Present (Rename_Spec) then
1337 -- Renaming_As_Body. Renaming declaration is the completion of
1338 -- the declaration of Rename_Spec. We will build an actual body
1339 -- for it at the freezing point.
1341 Set_Corresponding_Spec (N, Rename_Spec);
1342 Set_Corresponding_Body (Unit_Declaration_Node (Rename_Spec), New_S);
1344 if Ada_Version = Ada_83 and then Comes_From_Source (N) then
1345 Error_Msg_N ("(Ada 83) renaming cannot serve as a body", N);
1348 Set_Convention (New_S, Convention (Rename_Spec));
1349 Check_Fully_Conformant (New_S, Rename_Spec);
1350 Set_Public_Status (New_S);
1352 -- Indicate that the entity in the declaration functions like
1353 -- the corresponding body, and is not a new entity. The body will
1354 -- be constructed later at the freeze point, so indicate that
1355 -- the completion has not been seen yet.
1357 Set_Ekind (New_S, E_Subprogram_Body);
1358 New_S := Rename_Spec;
1359 Set_Has_Completion (Rename_Spec, False);
1361 -- Ada 2005: check overriding indicator.
1363 if Must_Override (Specification (N))
1364 and then not Is_Overriding_Operation (Rename_Spec)
1366 Error_Msg_NE ("subprogram& is not overriding", N, Rename_Spec);
1368 elsif Must_Not_Override (Specification (N))
1369 and then Is_Overriding_Operation (Rename_Spec)
1372 ("subprogram& overrides inherited operation", N, Rename_Spec);
1376 Generate_Definition (New_S);
1377 New_Overloaded_Entity (New_S);
1379 if Is_Entity_Name (Nam)
1380 and then Is_Intrinsic_Subprogram (Entity (Nam))
1384 Check_Delayed_Subprogram (New_S);
1388 -- There is no need for elaboration checks on the new entity, which
1389 -- may be called before the next freezing point where the body will
1390 -- appear. Elaboration checks refer to the real entity, not the one
1391 -- created by the renaming declaration.
1393 Set_Kill_Elaboration_Checks (New_S, True);
1395 if Etype (Nam) = Any_Type then
1396 Set_Has_Completion (New_S);
1399 elsif Nkind (Nam) = N_Selected_Component then
1401 -- Renamed entity is an entry or protected subprogram. For those
1402 -- cases an explicit body is built (at the point of freezing of
1403 -- this entity) that contains a call to the renamed entity.
1405 Analyze_Renamed_Entry (N, New_S, Present (Rename_Spec));
1408 elsif Nkind (Nam) = N_Explicit_Dereference then
1410 -- Renamed entity is designated by access_to_subprogram expression.
1411 -- Must build body to encapsulate call, as in the entry case.
1413 Analyze_Renamed_Dereference (N, New_S, Present (Rename_Spec));
1416 elsif Nkind (Nam) = N_Indexed_Component then
1417 Analyze_Renamed_Family_Member (N, New_S, Present (Rename_Spec));
1420 elsif Nkind (Nam) = N_Character_Literal then
1421 Analyze_Renamed_Character (N, New_S, Present (Rename_Spec));
1424 elsif (not Is_Entity_Name (Nam)
1425 and then Nkind (Nam) /= N_Operator_Symbol)
1426 or else not Is_Overloadable (Entity (Nam))
1428 Error_Msg_N ("expect valid subprogram name in renaming", N);
1433 -- Most common case: subprogram renames subprogram. No body is
1434 -- generated in this case, so we must indicate that the declaration
1435 -- is complete as is.
1437 if No (Rename_Spec) then
1438 Set_Has_Completion (New_S);
1441 -- Find the renamed entity that matches the given specification. Disable
1442 -- Ada_83 because there is no requirement of full conformance between
1443 -- renamed entity and new entity, even though the same circuit is used.
1444 -- This is a bit of a kludge, which introduces a really irregular use of
1445 -- Ada_Version[_Explicit]. Would be nice to find cleaner way to do this
1448 Ada_Version := Ada_Version_Type'Max (Ada_Version, Ada_95);
1449 Ada_Version_Explicit := Ada_Version;
1452 Old_S := Find_Renamed_Entity (N, Name (N), New_S, Is_Actual);
1455 if Old_S /= Any_Id then
1457 and then From_Default (N)
1459 -- This is an implicit reference to the default actual
1461 Generate_Reference (Old_S, Nam, Typ => 'i', Force => True);
1463 Generate_Reference (Old_S, Nam);
1466 -- For a renaming-as-body, require subtype conformance, but if the
1467 -- declaration being completed has not been frozen, then inherit the
1468 -- convention of the renamed subprogram prior to checking conformance
1469 -- (unless the renaming has an explicit convention established; the
1470 -- rule stated in the RM doesn't seem to address this ???).
1472 if Present (Rename_Spec) then
1473 Generate_Reference (Rename_Spec, Defining_Entity (Spec), 'b');
1474 Style.Check_Identifier (Defining_Entity (Spec), Rename_Spec);
1476 if not Is_Frozen (Rename_Spec) then
1477 if not Has_Convention_Pragma (Rename_Spec) then
1478 Set_Convention (New_S, Convention (Old_S));
1481 if Ekind (Old_S) /= E_Operator then
1482 Check_Mode_Conformant (New_S, Old_S, Spec);
1485 if Original_Subprogram (Old_S) = Rename_Spec then
1486 Error_Msg_N ("unfrozen subprogram cannot rename itself ", N);
1489 Check_Subtype_Conformant (New_S, Old_S, Spec);
1492 Check_Frozen_Renaming (N, Rename_Spec);
1494 -- Check explicitly that renamed entity is not intrinsic, because
1495 -- in in a generic the renamed body is not built. In this case,
1496 -- the renaming_as_body is a completion.
1498 if Inside_A_Generic then
1499 if Is_Frozen (Rename_Spec)
1500 and then Is_Intrinsic_Subprogram (Old_S)
1503 ("subprogram in renaming_as_body cannot be intrinsic",
1507 Set_Has_Completion (Rename_Spec);
1510 elsif Ekind (Old_S) /= E_Operator then
1511 Check_Mode_Conformant (New_S, Old_S);
1514 and then Error_Posted (New_S)
1516 Error_Msg_NE ("invalid actual subprogram: & #!", N, Old_S);
1520 if No (Rename_Spec) then
1522 -- The parameter profile of the new entity is that of the renamed
1523 -- entity: the subtypes given in the specification are irrelevant.
1525 Inherit_Renamed_Profile (New_S, Old_S);
1527 -- A call to the subprogram is transformed into a call to the
1528 -- renamed entity. This is transitive if the renamed entity is
1529 -- itself a renaming.
1531 if Present (Alias (Old_S)) then
1532 Set_Alias (New_S, Alias (Old_S));
1534 Set_Alias (New_S, Old_S);
1537 -- Note that we do not set Is_Intrinsic_Subprogram if we have a
1538 -- renaming as body, since the entity in this case is not an
1539 -- intrinsic (it calls an intrinsic, but we have a real body for
1540 -- this call, and it is in this body that the required intrinsic
1541 -- processing will take place).
1543 -- Also, if this is a renaming of inequality, the renamed operator
1544 -- is intrinsic, but what matters is the corresponding equality
1545 -- operator, which may be user-defined.
1547 Set_Is_Intrinsic_Subprogram
1549 Is_Intrinsic_Subprogram (Old_S)
1551 (Chars (Old_S) /= Name_Op_Ne
1552 or else Ekind (Old_S) = E_Operator
1554 Is_Intrinsic_Subprogram
1555 (Corresponding_Equality (Old_S))));
1557 if Ekind (Alias (New_S)) = E_Operator then
1558 Set_Has_Delayed_Freeze (New_S, False);
1561 -- If the renaming corresponds to an association for an abstract
1562 -- formal subprogram, then various attributes must be set to
1563 -- indicate that the renaming is an abstract dispatching operation
1564 -- with a controlling type.
1566 if Is_Actual and then Is_Abstract (Formal_Spec) then
1567 -- Mark the renaming as abstract here, so Find_Dispatching_Type
1568 -- see it as corresponding to a generic association for a
1569 -- formal abstract subprogram
1571 Set_Is_Abstract (New_S);
1574 New_S_Ctrl_Type : constant Entity_Id :=
1575 Find_Dispatching_Type (New_S);
1576 Old_S_Ctrl_Type : constant Entity_Id :=
1577 Find_Dispatching_Type (Old_S);
1580 if Old_S_Ctrl_Type /= New_S_Ctrl_Type then
1582 ("actual must be dispatching subprogram for type&",
1583 Nam, New_S_Ctrl_Type);
1586 Set_Is_Dispatching_Operation (New_S);
1587 Check_Controlling_Formals (New_S_Ctrl_Type, New_S);
1589 -- In the case where the actual in the formal subprogram
1590 -- is itself a formal abstract subprogram association,
1591 -- there's no dispatch table component or position to
1594 if Present (DTC_Entity (Old_S)) then
1595 Set_DTC_Entity (New_S, DTC_Entity (Old_S));
1596 Set_DT_Position (New_S, DT_Position (Old_S));
1604 and then (Old_S = New_S
1605 or else (Nkind (Nam) /= N_Expanded_Name
1606 and then Chars (Old_S) = Chars (New_S)))
1608 Error_Msg_N ("subprogram cannot rename itself", N);
1611 Set_Convention (New_S, Convention (Old_S));
1612 Set_Is_Abstract (New_S, Is_Abstract (Old_S));
1613 Check_Library_Unit_Renaming (N, Old_S);
1615 -- Pathological case: procedure renames entry in the scope of its
1616 -- task. Entry is given by simple name, but body must be built for
1617 -- procedure. Of course if called it will deadlock.
1619 if Ekind (Old_S) = E_Entry then
1620 Set_Has_Completion (New_S, False);
1621 Set_Alias (New_S, Empty);
1625 Freeze_Before (N, Old_S);
1626 Set_Has_Delayed_Freeze (New_S, False);
1627 Freeze_Before (N, New_S);
1629 -- An abstract subprogram is only allowed as an actual in the case
1630 -- where the formal subprogram is also abstract.
1632 if (Ekind (Old_S) = E_Procedure or else Ekind (Old_S) = E_Function)
1633 and then Is_Abstract (Old_S)
1634 and then not Is_Abstract (Formal_Spec)
1637 ("abstract subprogram not allowed as generic actual", Nam);
1642 -- A common error is to assume that implicit operators for types are
1643 -- defined in Standard, or in the scope of a subtype. In those cases
1644 -- where the renamed entity is given with an expanded name, it is
1645 -- worth mentioning that operators for the type are not declared in
1646 -- the scope given by the prefix.
1648 if Nkind (Nam) = N_Expanded_Name
1649 and then Nkind (Selector_Name (Nam)) = N_Operator_Symbol
1650 and then Scope (Entity (Nam)) = Standard_Standard
1653 T : constant Entity_Id :=
1654 Base_Type (Etype (First_Formal (New_S)));
1657 Error_Msg_Node_2 := Prefix (Nam);
1659 ("operator for type& is not declared in&", Prefix (Nam), T);
1664 ("no visible subprogram matches the specification for&",
1668 if Present (Candidate_Renaming) then
1674 F1 := First_Formal (Candidate_Renaming);
1675 F2 := First_Formal (New_S);
1677 while Present (F1) and then Present (F2) loop
1682 if Present (F1) and then Present (Default_Value (F1)) then
1683 if Present (Next_Formal (F1)) then
1685 ("\missing specification for &" &
1686 " and other formals with defaults", Spec, F1);
1689 ("\missing specification for &", Spec, F1);
1696 -- Ada 2005 AI 404: if the new subprogram is dispatching, verify that
1697 -- controlling access parameters are known non-null for the renamed
1698 -- subprogram. Test also applies to a subprogram instantiation that
1701 if Ada_Version >= Ada_05
1702 and then not Is_Dispatching_Operation (Old_S)
1703 and then Is_Dispatching_Operation (New_S)
1710 Old_F := First_Formal (Old_S);
1711 New_F := First_Formal (New_S);
1712 while Present (Old_F) loop
1713 if Ekind (Etype (Old_F)) = E_Anonymous_Access_Type
1714 and then Is_Controlling_Formal (New_F)
1715 and then not Can_Never_Be_Null (Old_F)
1717 Error_Msg_N ("access parameter is controlling,", New_F);
1718 Error_Msg_NE ("\corresponding parameter of& " &
1719 " must be explicitly null excluding", New_F, Old_S);
1722 Next_Formal (Old_F);
1723 Next_Formal (New_F);
1728 Ada_Version := Save_AV;
1729 Ada_Version_Explicit := Save_AV_Exp;
1730 end Analyze_Subprogram_Renaming;
1732 -------------------------
1733 -- Analyze_Use_Package --
1734 -------------------------
1736 -- Resolve the package names in the use clause, and make all the visible
1737 -- entities defined in the package potentially use-visible. If the package
1738 -- is already in use from a previous use clause, its visible entities are
1739 -- already use-visible. In that case, mark the occurrence as a redundant
1740 -- use. If the package is an open scope, i.e. if the use clause occurs
1741 -- within the package itself, ignore it.
1743 procedure Analyze_Use_Package (N : Node_Id) is
1744 Pack_Name : Node_Id;
1747 -- Start of processing for Analyze_Use_Package
1750 Set_Hidden_By_Use_Clause (N, No_Elist);
1752 -- Use clause is not allowed in a spec of a predefined package
1753 -- declaration except that packages whose file name starts a-n are OK
1754 -- (these are children of Ada.Numerics, and such packages are never
1755 -- loaded by Rtsfind).
1757 if Is_Predefined_File_Name (Unit_File_Name (Current_Sem_Unit))
1758 and then Name_Buffer (1 .. 3) /= "a-n"
1760 Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Declaration
1762 Error_Msg_N ("use clause not allowed in predefined spec", N);
1765 -- Chain clause to list of use clauses in current scope
1767 if Nkind (Parent (N)) /= N_Compilation_Unit then
1768 Chain_Use_Clause (N);
1771 -- Loop through package names to identify referenced packages
1773 Pack_Name := First (Names (N));
1775 while Present (Pack_Name) loop
1776 Analyze (Pack_Name);
1778 if Nkind (Parent (N)) = N_Compilation_Unit
1779 and then Nkind (Pack_Name) = N_Expanded_Name
1782 Pref : Node_Id := Prefix (Pack_Name);
1785 while Nkind (Pref) = N_Expanded_Name loop
1786 Pref := Prefix (Pref);
1789 if Entity (Pref) = Standard_Standard then
1791 ("predefined package Standard cannot appear"
1792 & " in a context clause", Pref);
1800 -- Loop through package names to mark all entities as potentially
1803 Pack_Name := First (Names (N));
1805 while Present (Pack_Name) loop
1807 if Is_Entity_Name (Pack_Name) then
1808 Pack := Entity (Pack_Name);
1810 if Ekind (Pack) /= E_Package
1811 and then Etype (Pack) /= Any_Type
1813 if Ekind (Pack) = E_Generic_Package then
1815 ("a generic package is not allowed in a use clause",
1818 Error_Msg_N ("& is not a usable package", Pack_Name);
1822 if Nkind (Parent (N)) = N_Compilation_Unit then
1823 Check_In_Previous_With_Clause (N, Pack_Name);
1826 if Applicable_Use (Pack_Name) then
1827 Use_One_Package (Pack, N);
1835 end Analyze_Use_Package;
1837 ----------------------
1838 -- Analyze_Use_Type --
1839 ----------------------
1841 procedure Analyze_Use_Type (N : Node_Id) is
1845 Set_Hidden_By_Use_Clause (N, No_Elist);
1847 -- Chain clause to list of use clauses in current scope
1849 if Nkind (Parent (N)) /= N_Compilation_Unit then
1850 Chain_Use_Clause (N);
1853 Id := First (Subtype_Marks (N));
1855 while Present (Id) loop
1858 if Entity (Id) /= Any_Type then
1861 if Nkind (Parent (N)) = N_Compilation_Unit then
1862 if Nkind (Id) = N_Identifier then
1863 Error_Msg_N ("type is not directly visible", Id);
1865 elsif Is_Child_Unit (Scope (Entity (Id)))
1866 and then Scope (Entity (Id)) /= System_Aux_Id
1868 Check_In_Previous_With_Clause (N, Prefix (Id));
1875 end Analyze_Use_Type;
1877 --------------------
1878 -- Applicable_Use --
1879 --------------------
1881 function Applicable_Use (Pack_Name : Node_Id) return Boolean is
1882 Pack : constant Entity_Id := Entity (Pack_Name);
1885 if In_Open_Scopes (Pack) then
1888 elsif In_Use (Pack) then
1889 Set_Redundant_Use (Pack_Name, True);
1892 elsif Present (Renamed_Object (Pack))
1893 and then In_Use (Renamed_Object (Pack))
1895 Set_Redundant_Use (Pack_Name, True);
1903 ------------------------
1904 -- Attribute_Renaming --
1905 ------------------------
1907 procedure Attribute_Renaming (N : Node_Id) is
1908 Loc : constant Source_Ptr := Sloc (N);
1909 Nam : constant Node_Id := Name (N);
1910 Spec : constant Node_Id := Specification (N);
1911 New_S : constant Entity_Id := Defining_Unit_Name (Spec);
1912 Aname : constant Name_Id := Attribute_Name (Nam);
1914 Form_Num : Nat := 0;
1915 Expr_List : List_Id := No_List;
1917 Attr_Node : Node_Id;
1918 Body_Node : Node_Id;
1919 Param_Spec : Node_Id;
1922 Generate_Definition (New_S);
1924 -- This procedure is called in the context of subprogram renaming,
1925 -- and thus the attribute must be one that is a subprogram. All of
1926 -- those have at least one formal parameter, with the singular
1927 -- exception of AST_Entry (which is a real oddity, it is odd that
1928 -- this can be renamed at all!)
1930 if not Is_Non_Empty_List (Parameter_Specifications (Spec)) then
1931 if Aname /= Name_AST_Entry then
1933 ("subprogram renaming an attribute must have formals", N);
1938 Param_Spec := First (Parameter_Specifications (Spec));
1940 while Present (Param_Spec) loop
1941 Form_Num := Form_Num + 1;
1943 if Nkind (Parameter_Type (Param_Spec)) /= N_Access_Definition then
1944 Find_Type (Parameter_Type (Param_Spec));
1946 -- The profile of the new entity denotes the base type (s) of
1947 -- the types given in the specification. For access parameters
1948 -- there are no subtypes involved.
1950 Rewrite (Parameter_Type (Param_Spec),
1952 (Base_Type (Entity (Parameter_Type (Param_Spec))), Loc));
1955 if No (Expr_List) then
1956 Expr_List := New_List;
1959 Append_To (Expr_List,
1960 Make_Identifier (Loc,
1961 Chars => Chars (Defining_Identifier (Param_Spec))));
1963 -- The expressions in the attribute reference are not freeze
1964 -- points. Neither is the attribute as a whole, see below.
1966 Set_Must_Not_Freeze (Last (Expr_List));
1971 -- Immediate error if too many formals. Other mismatches in numbers
1972 -- of number of types of parameters are detected when we analyze the
1973 -- body of the subprogram that we construct.
1975 if Form_Num > 2 then
1976 Error_Msg_N ("too many formals for attribute", N);
1978 -- Error if the attribute reference has expressions that look
1979 -- like formal parameters.
1981 elsif Present (Expressions (Nam)) then
1982 Error_Msg_N ("illegal expressions in attribute reference", Nam);
1985 Aname = Name_Compose or else
1986 Aname = Name_Exponent or else
1987 Aname = Name_Leading_Part or else
1988 Aname = Name_Pos or else
1989 Aname = Name_Round or else
1990 Aname = Name_Scaling or else
1993 if Nkind (N) = N_Subprogram_Renaming_Declaration
1994 and then Present (Corresponding_Formal_Spec (N))
1997 ("generic actual cannot be attribute involving universal type",
2001 ("attribute involving a universal type cannot be renamed",
2006 -- AST_Entry is an odd case. It doesn't really make much sense to
2007 -- allow it to be renamed, but that's the DEC rule, so we have to
2008 -- do it right. The point is that the AST_Entry call should be made
2009 -- now, and what the function will return is the returned value.
2011 -- Note that there is no Expr_List in this case anyway
2013 if Aname = Name_AST_Entry then
2020 Ent := Make_Defining_Identifier (Loc, New_Internal_Name ('R'));
2023 Make_Object_Declaration (Loc,
2024 Defining_Identifier => Ent,
2025 Object_Definition =>
2026 New_Occurrence_Of (RTE (RE_AST_Handler), Loc),
2028 Constant_Present => True);
2030 Set_Assignment_OK (Decl, True);
2031 Insert_Action (N, Decl);
2032 Attr_Node := Make_Identifier (Loc, Chars (Ent));
2035 -- For all other attributes, we rewrite the attribute node to have
2036 -- a list of expressions corresponding to the subprogram formals.
2037 -- A renaming declaration is not a freeze point, and the analysis of
2038 -- the attribute reference should not freeze the type of the prefix.
2042 Make_Attribute_Reference (Loc,
2043 Prefix => Prefix (Nam),
2044 Attribute_Name => Aname,
2045 Expressions => Expr_List);
2047 Set_Must_Not_Freeze (Attr_Node);
2048 Set_Must_Not_Freeze (Prefix (Nam));
2051 -- Case of renaming a function
2053 if Nkind (Spec) = N_Function_Specification then
2055 if Is_Procedure_Attribute_Name (Aname) then
2056 Error_Msg_N ("attribute can only be renamed as procedure", Nam);
2060 Find_Type (Subtype_Mark (Spec));
2061 Rewrite (Subtype_Mark (Spec),
2062 New_Reference_To (Base_Type (Entity (Subtype_Mark (Spec))), Loc));
2065 Make_Subprogram_Body (Loc,
2066 Specification => Spec,
2067 Declarations => New_List,
2068 Handled_Statement_Sequence =>
2069 Make_Handled_Sequence_Of_Statements (Loc,
2070 Statements => New_List (
2071 Make_Return_Statement (Loc,
2072 Expression => Attr_Node))));
2074 -- Case of renaming a procedure
2077 if not Is_Procedure_Attribute_Name (Aname) then
2078 Error_Msg_N ("attribute can only be renamed as function", Nam);
2083 Make_Subprogram_Body (Loc,
2084 Specification => Spec,
2085 Declarations => New_List,
2086 Handled_Statement_Sequence =>
2087 Make_Handled_Sequence_Of_Statements (Loc,
2088 Statements => New_List (Attr_Node)));
2091 Rewrite (N, Body_Node);
2094 if Is_Compilation_Unit (New_S) then
2096 ("a library unit can only rename another library unit", N);
2099 Set_Etype (New_S, Base_Type (Etype (New_S)));
2101 -- We suppress elaboration warnings for the resulting entity, since
2102 -- clearly they are not needed, and more particularly, in the case
2103 -- of a generic formal subprogram, the resulting entity can appear
2104 -- after the instantiation itself, and thus look like a bogus case
2105 -- of access before elaboration.
2107 Set_Suppress_Elaboration_Warnings (New_S);
2109 end Attribute_Renaming;
2111 ----------------------
2112 -- Chain_Use_Clause --
2113 ----------------------
2115 procedure Chain_Use_Clause (N : Node_Id) is
2117 Set_Next_Use_Clause (N,
2118 Scope_Stack.Table (Scope_Stack.Last).First_Use_Clause);
2119 Scope_Stack.Table (Scope_Stack.Last).First_Use_Clause := N;
2120 end Chain_Use_Clause;
2122 ---------------------------
2123 -- Check_Frozen_Renaming --
2124 ---------------------------
2126 procedure Check_Frozen_Renaming (N : Node_Id; Subp : Entity_Id) is
2132 and then not Has_Completion (Subp)
2136 (Parent (Declaration_Node (Subp)), Defining_Entity (N));
2138 if Is_Entity_Name (Name (N)) then
2139 Old_S := Entity (Name (N));
2141 if not Is_Frozen (Old_S)
2142 and then Operating_Mode /= Check_Semantics
2144 Append_Freeze_Action (Old_S, B_Node);
2146 Insert_After (N, B_Node);
2150 if Is_Intrinsic_Subprogram (Old_S)
2151 and then not In_Instance
2154 ("subprogram used in renaming_as_body cannot be intrinsic",
2159 Insert_After (N, B_Node);
2163 end Check_Frozen_Renaming;
2165 -----------------------------------
2166 -- Check_In_Previous_With_Clause --
2167 -----------------------------------
2169 procedure Check_In_Previous_With_Clause
2173 Pack : constant Entity_Id := Entity (Original_Node (Nam));
2178 Item := First (Context_Items (Parent (N)));
2180 while Present (Item)
2183 if Nkind (Item) = N_With_Clause
2185 -- Protect the frontend against previously reported
2188 and then Nkind (Name (Item)) /= N_Selected_Component
2189 and then Entity (Name (Item)) = Pack
2193 -- Find root library unit in with_clause
2195 while Nkind (Par) = N_Expanded_Name loop
2196 Par := Prefix (Par);
2199 if Is_Child_Unit (Entity (Original_Node (Par))) then
2201 ("& is not directly visible", Par, Entity (Par));
2210 -- On exit, package is not mentioned in a previous with_clause.
2211 -- Check if its prefix is.
2213 if Nkind (Nam) = N_Expanded_Name then
2214 Check_In_Previous_With_Clause (N, Prefix (Nam));
2216 elsif Pack /= Any_Id then
2217 Error_Msg_NE ("& is not visible", Nam, Pack);
2219 end Check_In_Previous_With_Clause;
2221 ---------------------------------
2222 -- Check_Library_Unit_Renaming --
2223 ---------------------------------
2225 procedure Check_Library_Unit_Renaming (N : Node_Id; Old_E : Entity_Id) is
2229 if Nkind (Parent (N)) /= N_Compilation_Unit then
2232 elsif Scope (Old_E) /= Standard_Standard
2233 and then not Is_Child_Unit (Old_E)
2235 Error_Msg_N ("renamed unit must be a library unit", Name (N));
2237 -- Entities defined in Standard (operators and boolean literals) cannot
2238 -- be renamed as library units.
2240 elsif Scope (Old_E) = Standard_Standard
2241 and then Sloc (Old_E) = Standard_Location
2243 Error_Msg_N ("renamed unit must be a library unit", Name (N));
2245 elsif Present (Parent_Spec (N))
2246 and then Nkind (Unit (Parent_Spec (N))) = N_Generic_Package_Declaration
2247 and then not Is_Child_Unit (Old_E)
2250 ("renamed unit must be a child unit of generic parent", Name (N));
2252 elsif Nkind (N) in N_Generic_Renaming_Declaration
2253 and then Nkind (Name (N)) = N_Expanded_Name
2254 and then Is_Generic_Instance (Entity (Prefix (Name (N))))
2255 and then Is_Generic_Unit (Old_E)
2258 ("renamed generic unit must be a library unit", Name (N));
2260 elsif Ekind (Old_E) = E_Package
2261 or else Ekind (Old_E) = E_Generic_Package
2263 -- Inherit categorization flags
2265 New_E := Defining_Entity (N);
2266 Set_Is_Pure (New_E, Is_Pure (Old_E));
2267 Set_Is_Preelaborated (New_E, Is_Preelaborated (Old_E));
2268 Set_Is_Remote_Call_Interface (New_E,
2269 Is_Remote_Call_Interface (Old_E));
2270 Set_Is_Remote_Types (New_E, Is_Remote_Types (Old_E));
2271 Set_Is_Shared_Passive (New_E, Is_Shared_Passive (Old_E));
2273 end Check_Library_Unit_Renaming;
2279 procedure End_Scope is
2285 Id := First_Entity (Current_Scope);
2287 while Present (Id) loop
2288 -- An entity in the current scope is not necessarily the first one
2289 -- on its homonym chain. Find its predecessor if any,
2290 -- If it is an internal entity, it will not be in the visibility
2291 -- chain altogether, and there is nothing to unchain.
2293 if Id /= Current_Entity (Id) then
2294 Prev := Current_Entity (Id);
2295 while Present (Prev)
2296 and then Present (Homonym (Prev))
2297 and then Homonym (Prev) /= Id
2299 Prev := Homonym (Prev);
2302 -- Skip to end of loop if Id is not in the visibility chain
2304 if No (Prev) or else Homonym (Prev) /= Id then
2312 Outer := Homonym (Id);
2313 Set_Is_Immediately_Visible (Id, False);
2315 while Present (Outer) and then Scope (Outer) = Current_Scope loop
2316 Outer := Homonym (Outer);
2319 -- Reset homonym link of other entities, but do not modify link
2320 -- between entities in current scope, so that the back-end can have
2321 -- a proper count of local overloadings.
2324 Set_Name_Entity_Id (Chars (Id), Outer);
2326 elsif Scope (Prev) /= Scope (Id) then
2327 Set_Homonym (Prev, Outer);
2334 -- If the scope generated freeze actions, place them before the
2335 -- current declaration and analyze them. Type declarations and
2336 -- the bodies of initialization procedures can generate such nodes.
2337 -- We follow the parent chain until we reach a list node, which is
2338 -- the enclosing list of declarations. If the list appears within
2339 -- a protected definition, move freeze nodes outside the protected
2343 (Scope_Stack.Table (Scope_Stack.Last).Pending_Freeze_Actions)
2347 L : constant List_Id := Scope_Stack.Table
2348 (Scope_Stack.Last).Pending_Freeze_Actions;
2351 if Is_Itype (Current_Scope) then
2352 Decl := Associated_Node_For_Itype (Current_Scope);
2354 Decl := Parent (Current_Scope);
2359 while not (Is_List_Member (Decl))
2360 or else Nkind (Parent (Decl)) = N_Protected_Definition
2361 or else Nkind (Parent (Decl)) = N_Task_Definition
2363 Decl := Parent (Decl);
2366 Insert_List_Before_And_Analyze (Decl, L);
2375 ---------------------
2376 -- End_Use_Clauses --
2377 ---------------------
2379 procedure End_Use_Clauses (Clause : Node_Id) is
2383 -- Remove Use_Type clauses first, because they affect the
2384 -- visibility of operators in subsequent used packages.
2387 while Present (U) loop
2388 if Nkind (U) = N_Use_Type_Clause then
2392 Next_Use_Clause (U);
2396 while Present (U) loop
2397 if Nkind (U) = N_Use_Package_Clause then
2398 End_Use_Package (U);
2401 Next_Use_Clause (U);
2403 end End_Use_Clauses;
2405 ---------------------
2406 -- End_Use_Package --
2407 ---------------------
2409 procedure End_Use_Package (N : Node_Id) is
2410 Pack_Name : Node_Id;
2415 function Is_Primitive_Operator
2417 F : Entity_Id) return Boolean;
2418 -- Check whether Op is a primitive operator of a use-visible type
2420 ---------------------------
2421 -- Is_Primitive_Operator --
2422 ---------------------------
2424 function Is_Primitive_Operator
2426 F : Entity_Id) return Boolean
2428 T : constant Entity_Id := Etype (F);
2432 and then Scope (T) = Scope (Op);
2433 end Is_Primitive_Operator;
2435 -- Start of processing for End_Use_Package
2438 Pack_Name := First (Names (N));
2440 while Present (Pack_Name) loop
2441 Pack := Entity (Pack_Name);
2443 if Ekind (Pack) = E_Package then
2445 if In_Open_Scopes (Pack) then
2448 elsif not Redundant_Use (Pack_Name) then
2449 Set_In_Use (Pack, False);
2450 Id := First_Entity (Pack);
2452 while Present (Id) loop
2454 -- Preserve use-visibility of operators that are primitive
2455 -- operators of a type that is use_visible through an active
2458 if Nkind (Id) = N_Defining_Operator_Symbol
2460 (Is_Primitive_Operator (Id, First_Formal (Id))
2462 (Present (Next_Formal (First_Formal (Id)))
2464 Is_Primitive_Operator
2465 (Id, Next_Formal (First_Formal (Id)))))
2470 Set_Is_Potentially_Use_Visible (Id, False);
2473 if Is_Private_Type (Id)
2474 and then Present (Full_View (Id))
2476 Set_Is_Potentially_Use_Visible (Full_View (Id), False);
2482 if Present (Renamed_Object (Pack)) then
2483 Set_In_Use (Renamed_Object (Pack), False);
2486 if Chars (Pack) = Name_System
2487 and then Scope (Pack) = Standard_Standard
2488 and then Present_System_Aux
2490 Id := First_Entity (System_Aux_Id);
2492 while Present (Id) loop
2493 Set_Is_Potentially_Use_Visible (Id, False);
2495 if Is_Private_Type (Id)
2496 and then Present (Full_View (Id))
2498 Set_Is_Potentially_Use_Visible (Full_View (Id), False);
2504 Set_In_Use (System_Aux_Id, False);
2508 Set_Redundant_Use (Pack_Name, False);
2516 if Present (Hidden_By_Use_Clause (N)) then
2517 Elmt := First_Elmt (Hidden_By_Use_Clause (N));
2519 while Present (Elmt) loop
2520 Set_Is_Immediately_Visible (Node (Elmt));
2524 Set_Hidden_By_Use_Clause (N, No_Elist);
2526 end End_Use_Package;
2532 procedure End_Use_Type (N : Node_Id) is
2539 Id := First (Subtype_Marks (N));
2541 while Present (Id) loop
2543 -- A call to rtsfind may occur while analyzing a use_type clause,
2544 -- in which case the type marks are not resolved yet, and there is
2545 -- nothing to remove.
2547 if not Is_Entity_Name (Id)
2548 or else No (Entity (Id))
2555 if T = Any_Type then
2558 -- Note that the use_Type clause may mention a subtype of the
2559 -- type whose primitive operations have been made visible. Here
2560 -- as elsewhere, it is the base type that matters for visibility.
2562 elsif In_Open_Scopes (Scope (Base_Type (T))) then
2565 elsif not Redundant_Use (Id) then
2566 Set_In_Use (T, False);
2567 Set_In_Use (Base_Type (T), False);
2568 Op_List := Collect_Primitive_Operations (T);
2569 Elmt := First_Elmt (Op_List);
2571 while Present (Elmt) loop
2573 if Nkind (Node (Elmt)) = N_Defining_Operator_Symbol then
2574 Set_Is_Potentially_Use_Visible (Node (Elmt), False);
2586 ----------------------
2587 -- Find_Direct_Name --
2588 ----------------------
2590 procedure Find_Direct_Name (N : Node_Id) is
2595 Inst : Entity_Id := Empty;
2596 -- Enclosing instance, if any
2598 Homonyms : Entity_Id;
2599 -- Saves start of homonym chain
2601 Nvis_Entity : Boolean;
2602 -- Set True to indicate that at there is at least one entity on the
2603 -- homonym chain which, while not visible, is visible enough from the
2604 -- user point of view to warrant an error message of "not visible"
2605 -- rather than undefined.
2607 Nvis_Is_Private_Subprg : Boolean := False;
2608 -- Ada 2005 (AI-262): Set True to indicate that a form of Beaujolais
2609 -- effect concerning library subprograms has been detected. Used to
2610 -- generate the precise error message.
2612 function From_Actual_Package (E : Entity_Id) return Boolean;
2613 -- Returns true if the entity is declared in a package that is
2614 -- an actual for a formal package of the current instance. Such an
2615 -- entity requires special handling because it may be use-visible
2616 -- but hides directly visible entities defined outside the instance.
2618 function Known_But_Invisible (E : Entity_Id) return Boolean;
2619 -- This function determines whether the entity E (which is not
2620 -- visible) can reasonably be considered to be known to the writer
2621 -- of the reference. This is a heuristic test, used only for the
2622 -- purposes of figuring out whether we prefer to complain that an
2623 -- entity is undefined or invisible (and identify the declaration
2624 -- of the invisible entity in the latter case). The point here is
2625 -- that we don't want to complain that something is invisible and
2626 -- then point to something entirely mysterious to the writer.
2628 procedure Nvis_Messages;
2629 -- Called if there are no visible entries for N, but there is at least
2630 -- one non-directly visible, or hidden declaration. This procedure
2631 -- outputs an appropriate set of error messages.
2633 procedure Undefined (Nvis : Boolean);
2634 -- This function is called if the current node has no corresponding
2635 -- visible entity or entities. The value set in Msg indicates whether
2636 -- an error message was generated (multiple error messages for the
2637 -- same variable are generally suppressed, see body for details).
2638 -- Msg is True if an error message was generated, False if not. This
2639 -- value is used by the caller to determine whether or not to output
2640 -- additional messages where appropriate. The parameter is set False
2641 -- to get the message "X is undefined", and True to get the message
2642 -- "X is not visible".
2644 -------------------------
2645 -- From_Actual_Package --
2646 -------------------------
2648 function From_Actual_Package (E : Entity_Id) return Boolean is
2649 Scop : constant Entity_Id := Scope (E);
2653 if not In_Instance then
2656 Inst := Current_Scope;
2658 while Present (Inst)
2659 and then Ekind (Inst) /= E_Package
2660 and then not Is_Generic_Instance (Inst)
2662 Inst := Scope (Inst);
2669 Act := First_Entity (Inst);
2671 while Present (Act) loop
2672 if Ekind (Act) = E_Package then
2674 -- Check for end of actuals list
2676 if Renamed_Object (Act) = Inst then
2679 elsif Present (Associated_Formal_Package (Act))
2680 and then Renamed_Object (Act) = Scop
2682 -- Entity comes from (instance of) formal package
2697 end From_Actual_Package;
2699 -------------------------
2700 -- Known_But_Invisible --
2701 -------------------------
2703 function Known_But_Invisible (E : Entity_Id) return Boolean is
2704 Fname : File_Name_Type;
2707 -- Entities in Standard are always considered to be known
2709 if Sloc (E) <= Standard_Location then
2712 -- An entity that does not come from source is always considered
2713 -- to be unknown, since it is an artifact of code expansion.
2715 elsif not Comes_From_Source (E) then
2718 -- In gnat internal mode, we consider all entities known
2720 elsif GNAT_Mode then
2724 -- Here we have an entity that is not from package Standard, and
2725 -- which comes from Source. See if it comes from an internal file.
2727 Fname := Unit_File_Name (Get_Source_Unit (E));
2729 -- Case of from internal file
2731 if Is_Internal_File_Name (Fname) then
2733 -- Private part entities in internal files are never considered
2734 -- to be known to the writer of normal application code.
2736 if Is_Hidden (E) then
2740 -- Entities from System packages other than System and
2741 -- System.Storage_Elements are not considered to be known.
2742 -- System.Auxxxx files are also considered known to the user.
2744 -- Should refine this at some point to generally distinguish
2745 -- between known and unknown internal files ???
2747 Get_Name_String (Fname);
2752 Name_Buffer (1 .. 2) /= "s-"
2754 Name_Buffer (3 .. 8) = "stoele"
2756 Name_Buffer (3 .. 5) = "aux";
2758 -- If not an internal file, then entity is definitely known,
2759 -- even if it is in a private part (the message generated will
2760 -- note that it is in a private part)
2765 end Known_But_Invisible;
2771 procedure Nvis_Messages is
2772 Comp_Unit : Node_Id;
2774 Hidden : Boolean := False;
2778 -- Ada 2005 (AI-262): Generate a precise error concerning the
2779 -- Beaujolais effect that was previously detected
2781 if Nvis_Is_Private_Subprg then
2783 pragma Assert (Nkind (E2) = N_Defining_Identifier
2784 and then Ekind (E2) = E_Function
2785 and then Scope (E2) = Standard_Standard
2786 and then Has_Private_With (E2));
2788 -- Find the sloc corresponding to the private with'ed unit
2790 Comp_Unit := Cunit (Current_Sem_Unit);
2791 Item := First (Context_Items (Comp_Unit));
2792 Error_Msg_Sloc := No_Location;
2794 while Present (Item) loop
2795 if Nkind (Item) = N_With_Clause
2796 and then Private_Present (Item)
2797 and then Entity (Name (Item)) = E2
2799 Error_Msg_Sloc := Sloc (Item);
2806 pragma Assert (Error_Msg_Sloc /= No_Location);
2808 Error_Msg_N ("(Ada 2005): hidden by private with clause #", N);
2812 Undefined (Nvis => True);
2816 -- First loop does hidden declarations
2819 while Present (Ent) loop
2820 if Is_Potentially_Use_Visible (Ent) then
2823 Error_Msg_N ("multiple use clauses cause hiding!", N);
2827 Error_Msg_Sloc := Sloc (Ent);
2828 Error_Msg_N ("hidden declaration#!", N);
2831 Ent := Homonym (Ent);
2834 -- If we found hidden declarations, then that's enough, don't
2835 -- bother looking for non-visible declarations as well.
2841 -- Second loop does non-directly visible declarations
2844 while Present (Ent) loop
2845 if not Is_Potentially_Use_Visible (Ent) then
2847 -- Do not bother the user with unknown entities
2849 if not Known_But_Invisible (Ent) then
2853 Error_Msg_Sloc := Sloc (Ent);
2855 -- Output message noting that there is a non-visible
2856 -- declaration, distinguishing the private part case.
2858 if Is_Hidden (Ent) then
2859 Error_Msg_N ("non-visible (private) declaration#!", N);
2861 Error_Msg_N ("non-visible declaration#!", N);
2863 if Is_Compilation_Unit (Ent)
2865 Nkind (Parent (Parent (N))) = N_Use_Package_Clause
2868 ("\possibly missing with_clause for&", N, Ent);
2872 -- Set entity and its containing package as referenced. We
2873 -- can't be sure of this, but this seems a better choice
2874 -- to avoid unused entity messages.
2876 if Comes_From_Source (Ent) then
2877 Set_Referenced (Ent);
2878 Set_Referenced (Cunit_Entity (Get_Source_Unit (Ent)));
2883 Ent := Homonym (Ent);
2893 procedure Undefined (Nvis : Boolean) is
2894 Emsg : Error_Msg_Id;
2897 -- We should never find an undefined internal name. If we do, then
2898 -- see if we have previous errors. If so, ignore on the grounds that
2899 -- it is probably a cascaded message (e.g. a block label from a badly
2900 -- formed block). If no previous errors, then we have a real internal
2901 -- error of some kind so raise an exception.
2903 if Is_Internal_Name (Chars (N)) then
2904 if Total_Errors_Detected /= 0 then
2907 raise Program_Error;
2911 -- A very specialized error check, if the undefined variable is
2912 -- a case tag, and the case type is an enumeration type, check
2913 -- for a possible misspelling, and if so, modify the identifier
2915 -- Named aggregate should also be handled similarly ???
2917 if Nkind (N) = N_Identifier
2918 and then Nkind (Parent (N)) = N_Case_Statement_Alternative
2920 Get_Name_String (Chars (N));
2923 Case_Str : constant String := Name_Buffer (1 .. Name_Len);
2924 Case_Stm : constant Node_Id := Parent (Parent (N));
2925 Case_Typ : constant Entity_Id := Etype (Expression (Case_Stm));
2926 Case_Rtp : constant Entity_Id := Root_Type (Case_Typ);
2931 if Is_Enumeration_Type (Case_Typ)
2932 and then Case_Rtp /= Standard_Character
2933 and then Case_Rtp /= Standard_Wide_Character
2934 and then Case_Rtp /= Standard_Wide_Wide_Character
2936 Lit := First_Literal (Case_Typ);
2937 Get_Name_String (Chars (Lit));
2939 if Chars (Lit) /= Chars (N)
2940 and then Is_Bad_Spelling_Of
2941 (Case_Str, Name_Buffer (1 .. Name_Len))
2943 Error_Msg_Node_2 := Lit;
2945 ("& is undefined, assume misspelling of &", N);
2946 Rewrite (N, New_Occurrence_Of (Lit, Sloc (N)));
2950 Lit := Next_Literal (Lit);
2955 -- Normal processing
2957 Set_Entity (N, Any_Id);
2958 Set_Etype (N, Any_Type);
2960 -- We use the table Urefs to keep track of entities for which we
2961 -- have issued errors for undefined references. Multiple errors
2962 -- for a single name are normally suppressed, however we modify
2963 -- the error message to alert the programmer to this effect.
2965 for J in Urefs.First .. Urefs.Last loop
2966 if Chars (N) = Chars (Urefs.Table (J).Node) then
2967 if Urefs.Table (J).Err /= No_Error_Msg
2968 and then Sloc (N) /= Urefs.Table (J).Loc
2970 Error_Msg_Node_1 := Urefs.Table (J).Node;
2972 if Urefs.Table (J).Nvis then
2973 Change_Error_Text (Urefs.Table (J).Err,
2974 "& is not visible (more references follow)");
2976 Change_Error_Text (Urefs.Table (J).Err,
2977 "& is undefined (more references follow)");
2980 Urefs.Table (J).Err := No_Error_Msg;
2983 -- Although we will set Msg False, and thus suppress the
2984 -- message, we also set Error_Posted True, to avoid any
2985 -- cascaded messages resulting from the undefined reference.
2988 Set_Error_Posted (N, True);
2993 -- If entry not found, this is first undefined occurrence
2996 Error_Msg_N ("& is not visible!", N);
3000 Error_Msg_N ("& is undefined!", N);
3003 -- A very bizarre special check, if the undefined identifier
3004 -- is put or put_line, then add a special error message (since
3005 -- this is a very common error for beginners to make).
3007 if Chars (N) = Name_Put or else Chars (N) = Name_Put_Line then
3008 Error_Msg_N ("\possible missing with of 'Text_'I'O!", N);
3011 -- Now check for possible misspellings
3013 Get_Name_String (Chars (N));
3017 Ematch : Entity_Id := Empty;
3019 Last_Name_Id : constant Name_Id :=
3020 Name_Id (Nat (First_Name_Id) +
3021 Name_Entries_Count - 1);
3023 S : constant String (1 .. Name_Len) :=
3024 Name_Buffer (1 .. Name_Len);
3027 for N in First_Name_Id .. Last_Name_Id loop
3028 E := Get_Name_Entity_Id (N);
3031 and then (Is_Immediately_Visible (E)
3033 Is_Potentially_Use_Visible (E))
3035 Get_Name_String (N);
3037 if Is_Bad_Spelling_Of
3038 (Name_Buffer (1 .. Name_Len), S)
3046 if Present (Ematch) then
3047 Error_Msg_NE ("\possible misspelling of&", N, Ematch);
3052 -- Make entry in undefined references table unless the full
3053 -- errors switch is set, in which case by refraining from
3054 -- generating the table entry, we guarantee that we get an
3055 -- error message for every undefined reference.
3057 if not All_Errors_Mode then
3058 Urefs.Increment_Last;
3059 Urefs.Table (Urefs.Last).Node := N;
3060 Urefs.Table (Urefs.Last).Err := Emsg;
3061 Urefs.Table (Urefs.Last).Nvis := Nvis;
3062 Urefs.Table (Urefs.Last).Loc := Sloc (N);
3068 -- Start of processing for Find_Direct_Name
3071 -- If the entity pointer is already set, this is an internal node, or
3072 -- a node that is analyzed more than once, after a tree modification.
3073 -- In such a case there is no resolution to perform, just set the type.
3075 if Present (Entity (N)) then
3076 if Is_Type (Entity (N)) then
3077 Set_Etype (N, Entity (N));
3081 Entyp : constant Entity_Id := Etype (Entity (N));
3084 -- One special case here. If the Etype field is already set,
3085 -- and references the packed array type corresponding to the
3086 -- etype of the referenced entity, then leave it alone. This
3087 -- happens for trees generated from Exp_Pakd, where expressions
3088 -- can be deliberately "mis-typed" to the packed array type.
3090 if Is_Array_Type (Entyp)
3091 and then Is_Packed (Entyp)
3092 and then Present (Etype (N))
3093 and then Etype (N) = Packed_Array_Type (Entyp)
3097 -- If not that special case, then just reset the Etype
3100 Set_Etype (N, Etype (Entity (N)));
3108 -- Here if Entity pointer was not set, we need full visibility analysis
3109 -- First we generate debugging output if the debug E flag is set.
3111 if Debug_Flag_E then
3112 Write_Str ("Looking for ");
3113 Write_Name (Chars (N));
3117 Homonyms := Current_Entity (N);
3118 Nvis_Entity := False;
3121 while Present (E) loop
3123 -- If entity is immediately visible or potentially use
3124 -- visible, then process the entity and we are done.
3126 if Is_Immediately_Visible (E) then
3127 goto Immediately_Visible_Entity;
3129 elsif Is_Potentially_Use_Visible (E) then
3130 goto Potentially_Use_Visible_Entity;
3132 -- Note if a known but invisible entity encountered
3134 elsif Known_But_Invisible (E) then
3135 Nvis_Entity := True;
3138 -- Move to next entity in chain and continue search
3143 -- If no entries on homonym chain that were potentially visible,
3144 -- and no entities reasonably considered as non-visible, then
3145 -- we have a plain undefined reference, with no additional
3146 -- explanation required!
3148 if not Nvis_Entity then
3149 Undefined (Nvis => False);
3151 -- Otherwise there is at least one entry on the homonym chain that
3152 -- is reasonably considered as being known and non-visible.
3160 -- Processing for a potentially use visible entry found. We must search
3161 -- the rest of the homonym chain for two reasons. First, if there is a
3162 -- directly visible entry, then none of the potentially use-visible
3163 -- entities are directly visible (RM 8.4(10)). Second, we need to check
3164 -- for the case of multiple potentially use-visible entries hiding one
3165 -- another and as a result being non-directly visible (RM 8.4(11)).
3167 <<Potentially_Use_Visible_Entity>> declare
3168 Only_One_Visible : Boolean := True;
3169 All_Overloadable : Boolean := Is_Overloadable (E);
3174 while Present (E2) loop
3175 if Is_Immediately_Visible (E2) then
3177 -- If the use-visible entity comes from the actual for a
3178 -- formal package, it hides a directly visible entity from
3179 -- outside the instance.
3181 if From_Actual_Package (E)
3182 and then Scope_Depth (E2) < Scope_Depth (Inst)
3187 goto Immediately_Visible_Entity;
3190 elsif Is_Potentially_Use_Visible (E2) then
3191 Only_One_Visible := False;
3192 All_Overloadable := All_Overloadable and Is_Overloadable (E2);
3194 -- Ada 2005 (AI-262): Protect against a form of Beujolais effect
3195 -- that can occurr in private_with clauses. Example:
3198 -- private with B; package A is
3199 -- package C is function B return Integer;
3201 -- V1 : Integer := B;
3202 -- private function B return Integer;
3203 -- V2 : Integer := B;
3206 -- V1 resolves to A.B, but V2 resolves to library unit B
3208 elsif Ekind (E2) = E_Function
3209 and then Scope (E2) = Standard_Standard
3210 and then Has_Private_With (E2)
3212 Only_One_Visible := False;
3213 All_Overloadable := False;
3214 Nvis_Is_Private_Subprg := True;
3221 -- On falling through this loop, we have checked that there are no
3222 -- immediately visible entities. Only_One_Visible is set if exactly
3223 -- one potentially use visible entity exists. All_Overloadable is
3224 -- set if all the potentially use visible entities are overloadable.
3225 -- The condition for legality is that either there is one potentially
3226 -- use visible entity, or if there is more than one, then all of them
3227 -- are overloadable.
3229 if Only_One_Visible or All_Overloadable then
3232 -- If there is more than one potentially use-visible entity and at
3233 -- least one of them non-overloadable, we have an error (RM 8.4(11).
3234 -- Note that E points to the first such entity on the homonym list.
3235 -- Special case: if one of the entities is declared in an actual
3236 -- package, it was visible in the generic, and takes precedence over
3237 -- other entities that are potentially use-visible. Same if it is
3238 -- declared in a local instantiation of the current instance.
3242 Inst := Current_Scope;
3244 -- Find current instance
3246 while Present (Inst)
3247 and then Inst /= Standard_Standard
3249 if Is_Generic_Instance (Inst) then
3253 Inst := Scope (Inst);
3258 while Present (E2) loop
3259 if From_Actual_Package (E2)
3261 (Is_Generic_Instance (Scope (E2))
3262 and then Scope_Depth (Scope (E2)) > Scope_Depth (Inst))
3275 Is_Predefined_File_Name (Unit_File_Name (Current_Sem_Unit))
3277 -- A use-clause in the body of a system file creates a
3278 -- conflict with some entity in a user scope, while rtsfind
3279 -- is active. Keep only the entity that comes from another
3283 while Present (E2) loop
3284 if Is_Predefined_File_Name
3285 (Unit_File_Name (Get_Source_Unit (Sloc (E2))))
3294 -- Entity must exist because predefined unit is correct.
3296 raise Program_Error;
3305 -- Come here with E set to the first immediately visible entity on
3306 -- the homonym chain. This is the one we want unless there is another
3307 -- immediately visible entity further on in the chain for a more
3308 -- inner scope (RM 8.3(8)).
3310 <<Immediately_Visible_Entity>> declare
3315 -- Find scope level of initial entity. When compiling through
3316 -- Rtsfind, the previous context is not completely invisible, and
3317 -- an outer entity may appear on the chain, whose scope is below
3318 -- the entry for Standard that delimits the current scope stack.
3319 -- Indicate that the level for this spurious entry is outside of
3320 -- the current scope stack.
3322 Level := Scope_Stack.Last;
3324 Scop := Scope_Stack.Table (Level).Entity;
3325 exit when Scop = Scope (E);
3327 exit when Scop = Standard_Standard;
3330 -- Now search remainder of homonym chain for more inner entry
3331 -- If the entity is Standard itself, it has no scope, and we
3332 -- compare it with the stack entry directly.
3335 while Present (E2) loop
3336 if Is_Immediately_Visible (E2) then
3337 for J in Level + 1 .. Scope_Stack.Last loop
3338 if Scope_Stack.Table (J).Entity = Scope (E2)
3339 or else Scope_Stack.Table (J).Entity = E2
3351 -- At the end of that loop, E is the innermost immediately
3352 -- visible entity, so we are all set.
3355 -- Come here with entity found, and stored in E
3359 if Comes_From_Source (N)
3360 and then Is_Remote_Access_To_Subprogram_Type (E)
3361 and then Expander_Active
3362 and then Get_PCS_Name /= Name_No_DSA
3365 New_Occurrence_Of (Equivalent_Type (E), Sloc (N)));
3370 -- Why no Style_Check here???
3375 Set_Etype (N, Get_Full_View (Etype (E)));
3378 if Debug_Flag_E then
3379 Write_Str (" found ");
3380 Write_Entity_Info (E, " ");
3383 -- If the Ekind of the entity is Void, it means that all homonyms
3384 -- are hidden from all visibility (RM 8.3(5,14-20)). However, this
3385 -- test is skipped if the current scope is a record and the name is
3386 -- a pragma argument expression (case of Atomic and Volatile pragmas
3387 -- and possibly other similar pragmas added later, which are allowed
3388 -- to reference components in the current record).
3390 if Ekind (E) = E_Void
3392 (not Is_Record_Type (Current_Scope)
3393 or else Nkind (Parent (N)) /= N_Pragma_Argument_Association)
3395 Premature_Usage (N);
3397 -- If the entity is overloadable, collect all interpretations
3398 -- of the name for subsequent overload resolution. We optimize
3399 -- a bit here to do this only if we have an overloadable entity
3400 -- that is not on its own on the homonym chain.
3402 elsif Is_Overloadable (E)
3403 and then (Present (Homonym (E)) or else Current_Entity (N) /= E)
3405 Collect_Interps (N);
3407 -- If no homonyms were visible, the entity is unambiguous
3409 if not Is_Overloaded (N) then
3410 Generate_Reference (E, N);
3413 -- Case of non-overloadable entity, set the entity providing that
3414 -- we do not have the case of a discriminant reference within a
3415 -- default expression. Such references are replaced with the
3416 -- corresponding discriminal, which is the formal corresponding to
3417 -- to the discriminant in the initialization procedure.
3420 -- Entity is unambiguous, indicate that it is referenced here
3421 -- One slightly odd case is that we do not want to set the
3422 -- Referenced flag if the entity is a label, and the identifier
3423 -- is the label in the source, since this is not a reference
3424 -- from the point of view of the user
3426 if Nkind (Parent (N)) = N_Label then
3428 R : constant Boolean := Referenced (E);
3431 Generate_Reference (E, N);
3432 Set_Referenced (E, R);
3435 -- Normal case, not a label. Generate reference
3438 Generate_Reference (E, N);
3441 -- Set Entity, with style check if need be. If this is a
3442 -- discriminant reference, it must be replaced by the
3443 -- corresponding discriminal, that is to say the parameter
3444 -- of the initialization procedure that corresponds to the
3445 -- discriminant. If this replacement is being performed, there
3446 -- is no style check to perform.
3448 -- This replacement must not be done if we are currently
3449 -- processing a generic spec or body, because the discriminal
3450 -- has not been not generated in this case.
3452 if not In_Default_Expression
3453 or else Ekind (E) /= E_Discriminant
3454 or else Inside_A_Generic
3456 Set_Entity_With_Style_Check (N, E);
3458 -- The replacement is not done either for a task discriminant that
3459 -- appears in a default expression of an entry parameter. See
3460 -- Expand_Discriminant in exp_ch2 for details on their handling.
3462 elsif Is_Concurrent_Type (Scope (E)) then
3464 P : Node_Id := Parent (N);
3468 and then Nkind (P) /= N_Parameter_Specification
3469 and then Nkind (P) /= N_Component_Declaration
3475 and then Nkind (P) = N_Parameter_Specification
3479 Set_Entity (N, Discriminal (E));
3483 -- Otherwise, this is a discriminant in a context in which
3484 -- it is a reference to the corresponding parameter of the
3485 -- init proc for the enclosing type.
3488 Set_Entity (N, Discriminal (E));
3492 end Find_Direct_Name;
3494 ------------------------
3495 -- Find_Expanded_Name --
3496 ------------------------
3498 -- This routine searches the homonym chain of the entity until it finds
3499 -- an entity declared in the scope denoted by the prefix. If the entity
3500 -- is private, it may nevertheless be immediately visible, if we are in
3501 -- the scope of its declaration.
3503 procedure Find_Expanded_Name (N : Node_Id) is
3504 Selector : constant Node_Id := Selector_Name (N);
3505 Candidate : Entity_Id := Empty;
3511 P_Name := Entity (Prefix (N));
3514 -- If the prefix is a renamed package, look for the entity
3515 -- in the original package.
3517 if Ekind (P_Name) = E_Package
3518 and then Present (Renamed_Object (P_Name))
3520 P_Name := Renamed_Object (P_Name);
3522 -- Rewrite node with entity field pointing to renamed object
3524 Rewrite (Prefix (N), New_Copy (Prefix (N)));
3525 Set_Entity (Prefix (N), P_Name);
3527 -- If the prefix is an object of a concurrent type, look for
3528 -- the entity in the associated task or protected type.
3530 elsif Is_Concurrent_Type (Etype (P_Name)) then
3531 P_Name := Etype (P_Name);
3534 Id := Current_Entity (Selector);
3536 while Present (Id) loop
3538 if Scope (Id) = P_Name then
3541 if Is_Child_Unit (Id) then
3542 exit when Is_Visible_Child_Unit (Id)
3543 or else Is_Immediately_Visible (Id);
3546 exit when not Is_Hidden (Id)
3547 or else Is_Immediately_Visible (Id);
3555 and then (Ekind (P_Name) = E_Procedure
3557 Ekind (P_Name) = E_Function)
3558 and then Is_Generic_Instance (P_Name)
3560 -- Expanded name denotes entity in (instance of) generic subprogram.
3561 -- The entity may be in the subprogram instance, or may denote one of
3562 -- the formals, which is declared in the enclosing wrapper package.
3564 P_Name := Scope (P_Name);
3566 Id := Current_Entity (Selector);
3567 while Present (Id) loop
3568 exit when Scope (Id) = P_Name;
3573 if No (Id) or else Chars (Id) /= Chars (Selector) then
3574 Set_Etype (N, Any_Type);
3576 -- If we are looking for an entity defined in System, try to
3577 -- find it in the child package that may have been provided as
3578 -- an extension to System. The Extend_System pragma will have
3579 -- supplied the name of the extension, which may have to be loaded.
3581 if Chars (P_Name) = Name_System
3582 and then Scope (P_Name) = Standard_Standard
3583 and then Present (System_Extend_Unit)
3584 and then Present_System_Aux (N)
3586 Set_Entity (Prefix (N), System_Aux_Id);
3587 Find_Expanded_Name (N);
3590 elsif Nkind (Selector) = N_Operator_Symbol
3591 and then Has_Implicit_Operator (N)
3593 -- There is an implicit instance of the predefined operator in
3594 -- the given scope. The operator entity is defined in Standard.
3595 -- Has_Implicit_Operator makes the node into an Expanded_Name.
3599 elsif Nkind (Selector) = N_Character_Literal
3600 and then Has_Implicit_Character_Literal (N)
3602 -- If there is no literal defined in the scope denoted by the
3603 -- prefix, the literal may belong to (a type derived from)
3604 -- Standard_Character, for which we have no explicit literals.
3609 -- If the prefix is a single concurrent object, use its
3610 -- name in the error message, rather than that of the
3613 if Is_Concurrent_Type (P_Name)
3614 and then Is_Internal_Name (Chars (P_Name))
3616 Error_Msg_Node_2 := Entity (Prefix (N));
3618 Error_Msg_Node_2 := P_Name;
3621 if P_Name = System_Aux_Id then
3622 P_Name := Scope (P_Name);
3623 Set_Entity (Prefix (N), P_Name);
3626 if Present (Candidate) then
3628 if Is_Child_Unit (Candidate) then
3630 -- If the candidate is a private child unit and we are
3631 -- in the visible part of a public unit, specialize the
3632 -- error message. There might be a private with_clause for
3633 -- it, but it is not currently active.
3635 if Is_Private_Descendant (Candidate)
3636 and then Ekind (Current_Scope) = E_Package
3637 and then not In_Private_Part (Current_Scope)
3638 and then not Is_Private_Descendant (Current_Scope)
3640 Error_Msg_N ("private child unit& is not visible here",
3644 ("missing with_clause for child unit &", Selector);
3647 Error_Msg_NE ("& is not a visible entity of&", N, Selector);
3651 -- Within the instantiation of a child unit, the prefix may
3652 -- denote the parent instance, but the selector has the
3653 -- name of the original child. Find whether we are within
3654 -- the corresponding instance, and get the proper entity, which
3655 -- can only be an enclosing scope.
3658 and then In_Open_Scopes (P_Name)
3659 and then Is_Generic_Instance (P_Name)
3662 S : Entity_Id := Current_Scope;
3666 for J in reverse 0 .. Scope_Stack.Last loop
3667 S := Scope_Stack.Table (J).Entity;
3669 exit when S = Standard_Standard;
3671 if Ekind (S) = E_Function
3672 or else Ekind (S) = E_Package
3673 or else Ekind (S) = E_Procedure
3675 P := Generic_Parent (Specification
3676 (Unit_Declaration_Node (S)));
3679 and then Chars (Scope (P)) = Chars (O_Name)
3680 and then Chars (P) = Chars (Selector)
3691 if Chars (P_Name) = Name_Ada
3692 and then Scope (P_Name) = Standard_Standard
3694 Error_Msg_Node_2 := Selector;
3695 Error_Msg_NE ("missing with for `&.&`", N, P_Name);
3697 -- If this is a selection from a dummy package, then
3698 -- suppress the error message, of course the entity
3699 -- is missing if the package is missing!
3701 elsif Sloc (Error_Msg_Node_2) = No_Location then
3704 -- Here we have the case of an undefined component
3708 Error_Msg_NE ("& not declared in&", N, Selector);
3710 -- Check for misspelling of some entity in prefix
3712 Id := First_Entity (P_Name);
3713 Get_Name_String (Chars (Selector));
3716 S : constant String (1 .. Name_Len) :=
3717 Name_Buffer (1 .. Name_Len);
3719 while Present (Id) loop
3720 Get_Name_String (Chars (Id));
3721 if Is_Bad_Spelling_Of
3722 (Name_Buffer (1 .. Name_Len), S)
3723 and then not Is_Internal_Name (Chars (Id))
3726 ("possible misspelling of&", Selector, Id);
3734 -- Specialize the message if this may be an instantiation
3735 -- of a child unit that was not mentioned in the context.
3737 if Nkind (Parent (N)) = N_Package_Instantiation
3738 and then Is_Generic_Instance (Entity (Prefix (N)))
3739 and then Is_Compilation_Unit
3740 (Generic_Parent (Parent (Entity (Prefix (N)))))
3743 ("\possible missing with clause on child unit&",
3754 if Comes_From_Source (N)
3755 and then Is_Remote_Access_To_Subprogram_Type (Id)
3756 and then Present (Equivalent_Type (Id))
3758 -- If we are not actually generating distribution code (i.e.
3759 -- the current PCS is the dummy non-distributed version), then
3760 -- the Equivalent_Type will be missing, and Id should be treated
3761 -- as a regular access-to-subprogram type.
3763 Id := Equivalent_Type (Id);
3764 Set_Chars (Selector, Chars (Id));
3767 -- Ada 2005 (AI-50217): Check usage of entities in limited withed units
3769 if Ekind (P_Name) = E_Package
3770 and then From_With_Type (P_Name)
3772 if From_With_Type (Id)
3773 or else Is_Type (Id)
3774 or else Ekind (Id) = E_Package
3779 ("limited withed package can only be used to access "
3780 & " incomplete types",
3785 if Is_Task_Type (P_Name)
3786 and then ((Ekind (Id) = E_Entry
3787 and then Nkind (Parent (N)) /= N_Attribute_Reference)
3789 (Ekind (Id) = E_Entry_Family
3791 Nkind (Parent (Parent (N))) /= N_Attribute_Reference))
3793 -- It is an entry call after all, either to the current task
3794 -- (which will deadlock) or to an enclosing task.
3796 Analyze_Selected_Component (N);
3800 Change_Selected_Component_To_Expanded_Name (N);
3802 -- Do style check and generate reference, but skip both steps if this
3803 -- entity has homonyms, since we may not have the right homonym set
3804 -- yet. The proper homonym will be set during the resolve phase.
3806 if Has_Homonym (Id) then
3809 Set_Entity_With_Style_Check (N, Id);
3810 Generate_Reference (Id, N);
3813 if Is_Type (Id) then
3816 Set_Etype (N, Get_Full_View (Etype (Id)));
3819 -- If the Ekind of the entity is Void, it means that all homonyms
3820 -- are hidden from all visibility (RM 8.3(5,14-20)).
3822 if Ekind (Id) = E_Void then
3823 Premature_Usage (N);
3825 elsif Is_Overloadable (Id)
3826 and then Present (Homonym (Id))
3829 H : Entity_Id := Homonym (Id);
3832 while Present (H) loop
3833 if Scope (H) = Scope (Id)
3836 or else Is_Immediately_Visible (H))
3838 Collect_Interps (N);
3845 -- If an extension of System is present, collect possible
3846 -- explicit overloadings declared in the extension.
3848 if Chars (P_Name) = Name_System
3849 and then Scope (P_Name) = Standard_Standard
3850 and then Present (System_Extend_Unit)
3851 and then Present_System_Aux (N)
3853 H := Current_Entity (Id);
3855 while Present (H) loop
3856 if Scope (H) = System_Aux_Id then
3857 Add_One_Interp (N, H, Etype (H));
3866 if Nkind (Selector_Name (N)) = N_Operator_Symbol
3867 and then Scope (Id) /= Standard_Standard
3869 -- In addition to user-defined operators in the given scope,
3870 -- there may be an implicit instance of the predefined
3871 -- operator. The operator (defined in Standard) is found
3872 -- in Has_Implicit_Operator, and added to the interpretations.
3873 -- Procedure Add_One_Interp will determine which hides which.
3875 if Has_Implicit_Operator (N) then
3879 end Find_Expanded_Name;
3881 -------------------------
3882 -- Find_Renamed_Entity --
3883 -------------------------
3885 function Find_Renamed_Entity
3889 Is_Actual : Boolean := False) return Entity_Id
3892 I1 : Interp_Index := 0; -- Suppress junk warnings
3898 function Enclosing_Instance return Entity_Id;
3899 -- If the renaming determines the entity for the default of a formal
3900 -- subprogram nested within another instance, choose the innermost
3901 -- candidate. This is because if the formal has a box, and we are within
3902 -- an enclosing instance where some candidate interpretations are local
3903 -- to this enclosing instance, we know that the default was properly
3904 -- resolved when analyzing the generic, so we prefer the local
3905 -- candidates to those that are external. This is not always the case
3906 -- but is a reasonable heuristic on the use of nested generics.
3907 -- The proper solution requires a full renaming model.
3909 function Within (Inner, Outer : Entity_Id) return Boolean;
3910 -- Determine whether a candidate subprogram is defined within
3911 -- the enclosing instance. If yes, it has precedence over outer
3914 function Is_Visible_Operation (Op : Entity_Id) return Boolean;
3915 -- If the renamed entity is an implicit operator, check whether it is
3916 -- visible because its operand type is properly visible. This
3917 -- check applies to explicit renamed entities that appear in the
3918 -- source in a renaming declaration or a formal subprogram instance,
3919 -- but not to default generic actuals with a name.
3921 ------------------------
3922 -- Enclosing_Instance --
3923 ------------------------
3925 function Enclosing_Instance return Entity_Id is
3929 if not Is_Generic_Instance (Current_Scope)
3930 and then not Is_Actual
3935 S := Scope (Current_Scope);
3937 while S /= Standard_Standard loop
3939 if Is_Generic_Instance (S) then
3947 end Enclosing_Instance;
3949 --------------------------
3950 -- Is_Visible_Operation --
3951 --------------------------
3953 function Is_Visible_Operation (Op : Entity_Id) return Boolean is
3959 if Ekind (Op) /= E_Operator
3960 or else Scope (Op) /= Standard_Standard
3961 or else (In_Instance
3964 or else Present (Enclosing_Instance)))
3969 -- For a fixed point type operator, check the resulting type,
3970 -- because it may be a mixed mode integer * fixed operation.
3972 if Present (Next_Formal (First_Formal (New_S)))
3973 and then Is_Fixed_Point_Type (Etype (New_S))
3975 Typ := Etype (New_S);
3977 Typ := Etype (First_Formal (New_S));
3980 Btyp := Base_Type (Typ);
3982 if Nkind (Nam) /= N_Expanded_Name then
3983 return (In_Open_Scopes (Scope (Btyp))
3984 or else Is_Potentially_Use_Visible (Btyp)
3985 or else In_Use (Btyp)
3986 or else In_Use (Scope (Btyp)));
3989 Scop := Entity (Prefix (Nam));
3991 if Ekind (Scop) = E_Package
3992 and then Present (Renamed_Object (Scop))
3994 Scop := Renamed_Object (Scop);
3997 -- Operator is visible if prefix of expanded name denotes
3998 -- scope of type, or else type type is defined in System_Aux
3999 -- and the prefix denotes System.
4001 return Scope (Btyp) = Scop
4002 or else (Scope (Btyp) = System_Aux_Id
4003 and then Scope (Scope (Btyp)) = Scop);
4006 end Is_Visible_Operation;
4012 function Within (Inner, Outer : Entity_Id) return Boolean is
4013 Sc : Entity_Id := Scope (Inner);
4016 while Sc /= Standard_Standard loop
4028 function Report_Overload return Entity_Id;
4029 -- List possible interpretations, and specialize message in the
4030 -- case of a generic actual.
4032 function Report_Overload return Entity_Id is
4036 ("ambiguous actual subprogram&, " &
4037 "possible interpretations: ", N, Nam);
4040 ("ambiguous subprogram, " &
4041 "possible interpretations: ", N);
4044 List_Interps (Nam, N);
4046 end Report_Overload;
4048 -- Start of processing for Find_Renamed_Entry
4052 Candidate_Renaming := Empty;
4054 if not Is_Overloaded (Nam) then
4055 if Entity_Matches_Spec (Entity (Nam), New_S)
4056 and then Is_Visible_Operation (Entity (Nam))
4058 Old_S := Entity (Nam);
4061 Present (First_Formal (Entity (Nam)))
4062 and then Present (First_Formal (New_S))
4063 and then (Base_Type (Etype (First_Formal (Entity (Nam))))
4064 = Base_Type (Etype (First_Formal (New_S))))
4066 Candidate_Renaming := Entity (Nam);
4070 Get_First_Interp (Nam, Ind, It);
4072 while Present (It.Nam) loop
4074 if Entity_Matches_Spec (It.Nam, New_S)
4075 and then Is_Visible_Operation (It.Nam)
4077 if Old_S /= Any_Id then
4079 -- Note: The call to Disambiguate only happens if a
4080 -- previous interpretation was found, in which case I1
4081 -- has received a value.
4083 It1 := Disambiguate (Nam, I1, Ind, Etype (Old_S));
4085 if It1 = No_Interp then
4087 Inst := Enclosing_Instance;
4089 if Present (Inst) then
4091 if Within (It.Nam, Inst) then
4094 elsif Within (Old_S, Inst) then
4098 return Report_Overload;
4102 return Report_Overload;
4116 Present (First_Formal (It.Nam))
4117 and then Present (First_Formal (New_S))
4118 and then (Base_Type (Etype (First_Formal (It.Nam)))
4119 = Base_Type (Etype (First_Formal (New_S))))
4121 Candidate_Renaming := It.Nam;
4124 Get_Next_Interp (Ind, It);
4127 Set_Entity (Nam, Old_S);
4128 Set_Is_Overloaded (Nam, False);
4132 end Find_Renamed_Entity;
4134 -----------------------------
4135 -- Find_Selected_Component --
4136 -----------------------------
4138 procedure Find_Selected_Component (N : Node_Id) is
4139 P : constant Node_Id := Prefix (N);
4142 -- Entity denoted by prefix
4152 if Nkind (P) = N_Error then
4155 -- If the selector already has an entity, the node has been
4156 -- constructed in the course of expansion, and is known to be
4157 -- valid. Do not verify that it is defined for the type (it may
4158 -- be a private component used in the expansion of record equality).
4160 elsif Present (Entity (Selector_Name (N))) then
4163 or else Etype (N) = Any_Type
4166 Sel_Name : constant Node_Id := Selector_Name (N);
4167 Selector : constant Entity_Id := Entity (Sel_Name);
4171 Set_Etype (Sel_Name, Etype (Selector));
4173 if not Is_Entity_Name (P) then
4177 -- Build an actual subtype except for the first parameter
4178 -- of an init proc, where this actual subtype is by
4179 -- definition incorrect, since the object is uninitialized
4180 -- (and does not even have defined discriminants etc.)
4182 if Is_Entity_Name (P)
4183 and then Ekind (Entity (P)) = E_Function
4185 Nam := New_Copy (P);
4187 if Is_Overloaded (P) then
4188 Save_Interps (P, Nam);
4192 Make_Function_Call (Sloc (P), Name => Nam));
4194 Analyze_Selected_Component (N);
4197 elsif Ekind (Selector) = E_Component
4198 and then (not Is_Entity_Name (P)
4199 or else Chars (Entity (P)) /= Name_uInit)
4202 Build_Actual_Subtype_Of_Component (
4203 Etype (Selector), N);
4208 if No (C_Etype) then
4209 C_Etype := Etype (Selector);
4211 Insert_Action (N, C_Etype);
4212 C_Etype := Defining_Identifier (C_Etype);
4215 Set_Etype (N, C_Etype);
4218 -- If this is the name of an entry or protected operation, and
4219 -- the prefix is an access type, insert an explicit dereference,
4220 -- so that entry calls are treated uniformly.
4222 if Is_Access_Type (Etype (P))
4223 and then Is_Concurrent_Type (Designated_Type (Etype (P)))
4226 New_P : constant Node_Id :=
4227 Make_Explicit_Dereference (Sloc (P),
4228 Prefix => Relocate_Node (P));
4231 Set_Etype (P, Designated_Type (Etype (Prefix (P))));
4235 -- If the selected component appears within a default expression
4236 -- and it has an actual subtype, the pre-analysis has not yet
4237 -- completed its analysis, because Insert_Actions is disabled in
4238 -- that context. Within the init proc of the enclosing type we
4239 -- must complete this analysis, if an actual subtype was created.
4241 elsif Inside_Init_Proc then
4243 Typ : constant Entity_Id := Etype (N);
4244 Decl : constant Node_Id := Declaration_Node (Typ);
4247 if Nkind (Decl) = N_Subtype_Declaration
4248 and then not Analyzed (Decl)
4249 and then Is_List_Member (Decl)
4250 and then No (Parent (Decl))
4253 Insert_Action (N, Decl);
4260 elsif Is_Entity_Name (P) then
4261 P_Name := Entity (P);
4263 -- The prefix may denote an enclosing type which is the completion
4264 -- of an incomplete type declaration.
4266 if Is_Type (P_Name) then
4267 Set_Entity (P, Get_Full_View (P_Name));
4268 Set_Etype (P, Entity (P));
4269 P_Name := Entity (P);
4272 P_Type := Base_Type (Etype (P));
4274 if Debug_Flag_E then
4275 Write_Str ("Found prefix type to be ");
4276 Write_Entity_Info (P_Type, " "); Write_Eol;
4279 -- First check for components of a record object (not the
4280 -- result of a call, which is handled below).
4282 if Is_Appropriate_For_Record (P_Type)
4283 and then not Is_Overloadable (P_Name)
4284 and then not Is_Type (P_Name)
4286 -- Selected component of record. Type checking will validate
4287 -- name of selector.
4289 Analyze_Selected_Component (N);
4291 elsif Is_Appropriate_For_Entry_Prefix (P_Type)
4292 and then not In_Open_Scopes (P_Name)
4293 and then (not Is_Concurrent_Type (Etype (P_Name))
4294 or else not In_Open_Scopes (Etype (P_Name)))
4296 -- Call to protected operation or entry. Type checking is
4297 -- needed on the prefix.
4299 Analyze_Selected_Component (N);
4301 elsif (In_Open_Scopes (P_Name)
4302 and then Ekind (P_Name) /= E_Void
4303 and then not Is_Overloadable (P_Name))
4304 or else (Is_Concurrent_Type (Etype (P_Name))
4305 and then In_Open_Scopes (Etype (P_Name)))
4307 -- Prefix denotes an enclosing loop, block, or task, i.e. an
4308 -- enclosing construct that is not a subprogram or accept.
4310 Find_Expanded_Name (N);
4312 elsif Ekind (P_Name) = E_Package then
4313 Find_Expanded_Name (N);
4315 elsif Is_Overloadable (P_Name) then
4317 -- The subprogram may be a renaming (of an enclosing scope) as
4318 -- in the case of the name of the generic within an instantiation.
4320 if (Ekind (P_Name) = E_Procedure
4321 or else Ekind (P_Name) = E_Function)
4322 and then Present (Alias (P_Name))
4323 and then Is_Generic_Instance (Alias (P_Name))
4325 P_Name := Alias (P_Name);
4328 if Is_Overloaded (P) then
4330 -- The prefix must resolve to a unique enclosing construct
4333 Found : Boolean := False;
4338 Get_First_Interp (P, Ind, It);
4340 while Present (It.Nam) loop
4342 if In_Open_Scopes (It.Nam) then
4345 "prefix must be unique enclosing scope", N);
4346 Set_Entity (N, Any_Id);
4347 Set_Etype (N, Any_Type);
4356 Get_Next_Interp (Ind, It);
4361 if In_Open_Scopes (P_Name) then
4362 Set_Entity (P, P_Name);
4363 Set_Is_Overloaded (P, False);
4364 Find_Expanded_Name (N);
4367 -- If no interpretation as an expanded name is possible, it
4368 -- must be a selected component of a record returned by a
4369 -- function call. Reformat prefix as a function call, the
4370 -- rest is done by type resolution. If the prefix is a
4371 -- procedure or entry, as is P.X; this is an error.
4373 if Ekind (P_Name) /= E_Function
4374 and then (not Is_Overloaded (P)
4376 Nkind (Parent (N)) = N_Procedure_Call_Statement)
4379 -- Prefix may mention a package that is hidden by a local
4380 -- declaration: let the user know. Scan the full homonym
4381 -- chain, the candidate package may be anywhere on it.
4383 if Present (Homonym (Current_Entity (P_Name))) then
4385 P_Name := Current_Entity (P_Name);
4387 while Present (P_Name) loop
4388 exit when Ekind (P_Name) = E_Package;
4389 P_Name := Homonym (P_Name);
4392 if Present (P_Name) then
4393 Error_Msg_Sloc := Sloc (Entity (Prefix (N)));
4396 ("package& is hidden by declaration#",
4399 Set_Entity (Prefix (N), P_Name);
4400 Find_Expanded_Name (N);
4403 P_Name := Entity (Prefix (N));
4408 ("invalid prefix in selected component&", N, P_Name);
4409 Change_Selected_Component_To_Expanded_Name (N);
4410 Set_Entity (N, Any_Id);
4411 Set_Etype (N, Any_Type);
4414 Nam := New_Copy (P);
4415 Save_Interps (P, Nam);
4417 Make_Function_Call (Sloc (P), Name => Nam));
4419 Analyze_Selected_Component (N);
4423 -- Remaining cases generate various error messages
4426 -- Format node as expanded name, to avoid cascaded errors
4428 Change_Selected_Component_To_Expanded_Name (N);
4429 Set_Entity (N, Any_Id);
4430 Set_Etype (N, Any_Type);
4432 -- Issue error message, but avoid this if error issued already.
4433 -- Use identifier of prefix if one is available.
4435 if P_Name = Any_Id then
4438 elsif Ekind (P_Name) = E_Void then
4439 Premature_Usage (P);
4441 elsif Nkind (P) /= N_Attribute_Reference then
4443 "invalid prefix in selected component&", P);
4445 if Is_Access_Type (P_Type)
4446 and then Ekind (Designated_Type (P_Type)) = E_Incomplete_Type
4449 ("\dereference must not be of an incomplete type " &
4450 "('R'M 3.10.1)", P);
4455 "invalid prefix in selected component", P);
4460 -- If prefix is not the name of an entity, it must be an expression,
4461 -- whose type is appropriate for a record. This is determined by
4464 Analyze_Selected_Component (N);
4466 end Find_Selected_Component;
4472 procedure Find_Type (N : Node_Id) is
4482 elsif Nkind (N) = N_Attribute_Reference then
4484 -- Class attribute. This is only valid in Ada 95 mode, but we don't
4485 -- do a check, since the tagged type referenced could only exist if
4486 -- we were in 95 mode when it was declared (or, if we were in Ada
4487 -- 83 mode, then an error message would already have been issued).
4489 if Attribute_Name (N) = Name_Class then
4490 Check_Restriction (No_Dispatch, N);
4491 Find_Type (Prefix (N));
4493 -- Propagate error from bad prefix
4495 if Etype (Prefix (N)) = Any_Type then
4496 Set_Entity (N, Any_Type);
4497 Set_Etype (N, Any_Type);
4501 T := Base_Type (Entity (Prefix (N)));
4503 -- Case of non-tagged type
4505 if not Is_Tagged_Type (T) then
4506 if Ekind (T) = E_Incomplete_Type then
4508 -- It is legal to denote the class type of an incomplete
4509 -- type. The full type will have to be tagged, of course.
4511 Set_Is_Tagged_Type (T);
4512 Make_Class_Wide_Type (T);
4513 Set_Entity (N, Class_Wide_Type (T));
4514 Set_Etype (N, Class_Wide_Type (T));
4516 elsif Ekind (T) = E_Private_Type
4517 and then not Is_Generic_Type (T)
4518 and then In_Private_Part (Scope (T))
4520 -- The Class attribute can be applied to an untagged
4521 -- private type fulfilled by a tagged type prior to
4522 -- the full type declaration (but only within the
4523 -- parent package's private part). Create the class-wide
4524 -- type now and check that the full type is tagged
4525 -- later during its analysis. Note that we do not
4526 -- mark the private type as tagged, unlike the case
4527 -- of incomplete types, because the type must still
4528 -- appear untagged to outside units.
4530 if not Present (Class_Wide_Type (T)) then
4531 Make_Class_Wide_Type (T);
4534 Set_Entity (N, Class_Wide_Type (T));
4535 Set_Etype (N, Class_Wide_Type (T));
4538 -- Should we introduce a type Any_Tagged and use
4539 -- Wrong_Type here, it would be a bit more consistent???
4542 ("tagged type required, found}",
4543 Prefix (N), First_Subtype (T));
4544 Set_Entity (N, Any_Type);
4548 -- Case of tagged type
4551 C := Class_Wide_Type (Entity (Prefix (N)));
4552 Set_Entity_With_Style_Check (N, C);
4553 Generate_Reference (C, N);
4557 -- Base attribute, not allowed in Ada 83
4559 elsif Attribute_Name (N) = Name_Base then
4560 if Ada_Version = Ada_83 and then Comes_From_Source (N) then
4562 ("(Ada 83) Base attribute not allowed in subtype mark", N);
4565 Find_Type (Prefix (N));
4566 Typ := Entity (Prefix (N));
4568 if Ada_Version >= Ada_95
4569 and then not Is_Scalar_Type (Typ)
4570 and then not Is_Generic_Type (Typ)
4573 ("prefix of Base attribute must be scalar type",
4576 elsif Sloc (Typ) = Standard_Location
4577 and then Base_Type (Typ) = Typ
4578 and then Warn_On_Redundant_Constructs
4581 ("?redudant attribute, & is its own base type", N, Typ);
4584 T := Base_Type (Typ);
4586 -- Rewrite attribute reference with type itself (see similar
4587 -- processing in Analyze_Attribute, case Base). Preserve
4588 -- prefix if present, for other legality checks.
4590 if Nkind (Prefix (N)) = N_Expanded_Name then
4592 Make_Expanded_Name (Sloc (N),
4593 Chars => Chars (Entity (N)),
4594 Prefix => New_Copy (Prefix (Prefix (N))),
4596 New_Reference_To (Entity (N), Sloc (N))));
4600 New_Reference_To (Entity (N), Sloc (N)));
4607 -- All other attributes are invalid in a subtype mark
4610 Error_Msg_N ("invalid attribute in subtype mark", N);
4616 if Is_Entity_Name (N) then
4617 T_Name := Entity (N);
4619 Error_Msg_N ("subtype mark required in this context", N);
4620 Set_Etype (N, Any_Type);
4624 if T_Name = Any_Id or else Etype (N) = Any_Type then
4626 -- Undefined id. Make it into a valid type
4628 Set_Entity (N, Any_Type);
4630 elsif not Is_Type (T_Name)
4631 and then T_Name /= Standard_Void_Type
4633 Error_Msg_Sloc := Sloc (T_Name);
4634 Error_Msg_N ("subtype mark required in this context", N);
4635 Error_Msg_NE ("\found & declared#", N, T_Name);
4636 Set_Entity (N, Any_Type);
4639 T_Name := Get_Full_View (T_Name);
4641 if In_Open_Scopes (T_Name) then
4642 if Ekind (Base_Type (T_Name)) = E_Task_Type then
4643 Error_Msg_N ("task type cannot be used as type mark " &
4644 "within its own body", N);
4646 Error_Msg_N ("type declaration cannot refer to itself", N);
4649 Set_Etype (N, Any_Type);
4650 Set_Entity (N, Any_Type);
4651 Set_Error_Posted (T_Name);
4655 Set_Entity (N, T_Name);
4656 Set_Etype (N, T_Name);
4660 if Present (Etype (N)) and then Comes_From_Source (N) then
4661 if Is_Fixed_Point_Type (Etype (N)) then
4662 Check_Restriction (No_Fixed_Point, N);
4663 elsif Is_Floating_Point_Type (Etype (N)) then
4664 Check_Restriction (No_Floating_Point, N);
4673 function Get_Full_View (T_Name : Entity_Id) return Entity_Id is
4675 if Ekind (T_Name) = E_Incomplete_Type
4676 and then Present (Full_View (T_Name))
4678 return Full_View (T_Name);
4680 elsif Is_Class_Wide_Type (T_Name)
4681 and then Ekind (Root_Type (T_Name)) = E_Incomplete_Type
4682 and then Present (Full_View (Root_Type (T_Name)))
4684 return Class_Wide_Type (Full_View (Root_Type (T_Name)));
4691 ------------------------------------
4692 -- Has_Implicit_Character_Literal --
4693 ------------------------------------
4695 function Has_Implicit_Character_Literal (N : Node_Id) return Boolean is
4697 Found : Boolean := False;
4698 P : constant Entity_Id := Entity (Prefix (N));
4699 Priv_Id : Entity_Id := Empty;
4702 if Ekind (P) = E_Package
4703 and then not In_Open_Scopes (P)
4705 Priv_Id := First_Private_Entity (P);
4708 if P = Standard_Standard then
4709 Change_Selected_Component_To_Expanded_Name (N);
4710 Rewrite (N, Selector_Name (N));
4712 Set_Etype (Original_Node (N), Standard_Character);
4716 Id := First_Entity (P);
4719 and then Id /= Priv_Id
4721 if Is_Character_Type (Id)
4722 and then (Root_Type (Id) = Standard_Character
4723 or else Root_Type (Id) = Standard_Wide_Character
4724 or else Root_Type (Id) = Standard_Wide_Wide_Character)
4725 and then Id = Base_Type (Id)
4727 -- We replace the node with the literal itself, resolve as a
4728 -- character, and set the type correctly.
4731 Change_Selected_Component_To_Expanded_Name (N);
4732 Rewrite (N, Selector_Name (N));
4735 Set_Etype (Original_Node (N), Id);
4739 -- More than one type derived from Character in given scope.
4740 -- Collect all possible interpretations.
4742 Add_One_Interp (N, Id, Id);
4750 end Has_Implicit_Character_Literal;
4752 ----------------------
4753 -- Has_Private_With --
4754 ----------------------
4756 function Has_Private_With (E : Entity_Id) return Boolean is
4757 Comp_Unit : constant Node_Id := Cunit (Current_Sem_Unit);
4761 Item := First (Context_Items (Comp_Unit));
4762 while Present (Item) loop
4763 if Nkind (Item) = N_With_Clause
4764 and then Private_Present (Item)
4765 and then Entity (Name (Item)) = E
4774 end Has_Private_With;
4776 ---------------------------
4777 -- Has_Implicit_Operator --
4778 ---------------------------
4780 function Has_Implicit_Operator (N : Node_Id) return Boolean is
4781 Op_Id : constant Name_Id := Chars (Selector_Name (N));
4782 P : constant Entity_Id := Entity (Prefix (N));
4784 Priv_Id : Entity_Id := Empty;
4786 procedure Add_Implicit_Operator
4788 Op_Type : Entity_Id := Empty);
4789 -- Add implicit interpretation to node N, using the type for which
4790 -- a predefined operator exists. If the operator yields a boolean
4791 -- type, the Operand_Type is implicitly referenced by the operator,
4792 -- and a reference to it must be generated.
4794 ---------------------------
4795 -- Add_Implicit_Operator --
4796 ---------------------------
4798 procedure Add_Implicit_Operator
4800 Op_Type : Entity_Id := Empty)
4802 Predef_Op : Entity_Id;
4805 Predef_Op := Current_Entity (Selector_Name (N));
4807 while Present (Predef_Op)
4808 and then Scope (Predef_Op) /= Standard_Standard
4810 Predef_Op := Homonym (Predef_Op);
4813 if Nkind (N) = N_Selected_Component then
4814 Change_Selected_Component_To_Expanded_Name (N);
4817 Add_One_Interp (N, Predef_Op, T);
4819 -- For operators with unary and binary interpretations, add both
4821 if Present (Homonym (Predef_Op)) then
4822 Add_One_Interp (N, Homonym (Predef_Op), T);
4825 -- The node is a reference to a predefined operator, and
4826 -- an implicit reference to the type of its operands.
4828 if Present (Op_Type) then
4829 Generate_Operator_Reference (N, Op_Type);
4831 Generate_Operator_Reference (N, T);
4833 end Add_Implicit_Operator;
4835 -- Start of processing for Has_Implicit_Operator
4839 if Ekind (P) = E_Package
4840 and then not In_Open_Scopes (P)
4842 Priv_Id := First_Private_Entity (P);
4845 Id := First_Entity (P);
4849 -- Boolean operators: an implicit declaration exists if the scope
4850 -- contains a declaration for a derived Boolean type, or for an
4851 -- array of Boolean type.
4853 when Name_Op_And | Name_Op_Not | Name_Op_Or | Name_Op_Xor =>
4855 while Id /= Priv_Id loop
4857 if Valid_Boolean_Arg (Id)
4858 and then Id = Base_Type (Id)
4860 Add_Implicit_Operator (Id);
4867 -- Equality: look for any non-limited type (result is Boolean)
4869 when Name_Op_Eq | Name_Op_Ne =>
4871 while Id /= Priv_Id loop
4874 and then not Is_Limited_Type (Id)
4875 and then Id = Base_Type (Id)
4877 Add_Implicit_Operator (Standard_Boolean, Id);
4884 -- Comparison operators: scalar type, or array of scalar
4886 when Name_Op_Lt | Name_Op_Le | Name_Op_Gt | Name_Op_Ge =>
4888 while Id /= Priv_Id loop
4889 if (Is_Scalar_Type (Id)
4890 or else (Is_Array_Type (Id)
4891 and then Is_Scalar_Type (Component_Type (Id))))
4892 and then Id = Base_Type (Id)
4894 Add_Implicit_Operator (Standard_Boolean, Id);
4901 -- Arithmetic operators: any numeric type
4912 while Id /= Priv_Id loop
4913 if Is_Numeric_Type (Id)
4914 and then Id = Base_Type (Id)
4916 Add_Implicit_Operator (Id);
4923 -- Concatenation: any one-dimensional array type
4925 when Name_Op_Concat =>
4927 while Id /= Priv_Id loop
4928 if Is_Array_Type (Id) and then Number_Dimensions (Id) = 1
4929 and then Id = Base_Type (Id)
4931 Add_Implicit_Operator (Id);
4938 -- What is the others condition here? Should we be using a
4939 -- subtype of Name_Id that would restrict to operators ???
4941 when others => null;
4945 -- If we fall through, then we do not have an implicit operator
4949 end Has_Implicit_Operator;
4951 --------------------
4952 -- In_Open_Scopes --
4953 --------------------
4955 function In_Open_Scopes (S : Entity_Id) return Boolean is
4957 -- Since there are several scope stacks maintained by Scope_Stack each
4958 -- delineated by Standard (see comments by definition of Scope_Stack)
4959 -- it is necessary to end the search when Standard is reached.
4961 for J in reverse 0 .. Scope_Stack.Last loop
4962 if Scope_Stack.Table (J).Entity = S then
4966 -- We need Is_Active_Stack_Base to tell us when to stop rather
4967 -- than checking for Standard_Standard because there are cases
4968 -- where Standard_Standard appears in the middle of the active
4969 -- set of scopes. This affects the declaration and overriding
4970 -- of private inherited operations in instantiations of generic
4973 exit when Scope_Stack.Table (J).Is_Active_Stack_Base;
4979 -----------------------------
4980 -- Inherit_Renamed_Profile --
4981 -----------------------------
4983 procedure Inherit_Renamed_Profile (New_S : Entity_Id; Old_S : Entity_Id) is
4990 if Ekind (Old_S) = E_Operator then
4992 New_F := First_Formal (New_S);
4994 while Present (New_F) loop
4995 Set_Etype (New_F, Base_Type (Etype (New_F)));
4996 Next_Formal (New_F);
4999 Set_Etype (New_S, Base_Type (Etype (New_S)));
5002 New_F := First_Formal (New_S);
5003 Old_F := First_Formal (Old_S);
5005 while Present (New_F) loop
5006 New_T := Etype (New_F);
5007 Old_T := Etype (Old_F);
5009 -- If the new type is a renaming of the old one, as is the
5010 -- case for actuals in instances, retain its name, to simplify
5011 -- later disambiguation.
5013 if Nkind (Parent (New_T)) = N_Subtype_Declaration
5014 and then Is_Entity_Name (Subtype_Indication (Parent (New_T)))
5015 and then Entity (Subtype_Indication (Parent (New_T))) = Old_T
5019 Set_Etype (New_F, Old_T);
5022 Next_Formal (New_F);
5023 Next_Formal (Old_F);
5026 if Ekind (Old_S) = E_Function
5027 or else Ekind (Old_S) = E_Enumeration_Literal
5029 Set_Etype (New_S, Etype (Old_S));
5032 end Inherit_Renamed_Profile;
5038 procedure Initialize is
5043 -------------------------
5044 -- Install_Use_Clauses --
5045 -------------------------
5047 procedure Install_Use_Clauses
5049 Force_Installation : Boolean := False)
5051 U : Node_Id := Clause;
5056 while Present (U) loop
5058 -- Case of USE package
5060 if Nkind (U) = N_Use_Package_Clause then
5061 P := First (Names (U));
5063 while Present (P) loop
5066 if Ekind (Id) = E_Package then
5069 Set_Redundant_Use (P, True);
5071 elsif Present (Renamed_Object (Id))
5072 and then In_Use (Renamed_Object (Id))
5074 Set_Redundant_Use (P, True);
5076 elsif Force_Installation or else Applicable_Use (P) then
5077 Use_One_Package (Id, U);
5088 P := First (Subtype_Marks (U));
5090 while Present (P) loop
5091 if not Is_Entity_Name (P)
5092 or else No (Entity (P))
5096 elsif Entity (P) /= Any_Type then
5104 Next_Use_Clause (U);
5106 end Install_Use_Clauses;
5108 -------------------------------------
5109 -- Is_Appropriate_For_Entry_Prefix --
5110 -------------------------------------
5112 function Is_Appropriate_For_Entry_Prefix (T : Entity_Id) return Boolean is
5113 P_Type : Entity_Id := T;
5116 if Is_Access_Type (P_Type) then
5117 P_Type := Designated_Type (P_Type);
5120 return Is_Task_Type (P_Type) or else Is_Protected_Type (P_Type);
5121 end Is_Appropriate_For_Entry_Prefix;
5123 -------------------------------
5124 -- Is_Appropriate_For_Record --
5125 -------------------------------
5127 function Is_Appropriate_For_Record (T : Entity_Id) return Boolean is
5129 function Has_Components (T1 : Entity_Id) return Boolean;
5130 -- Determine if given type has components (i.e. is either a record
5131 -- type or a type that has discriminants).
5133 function Has_Components (T1 : Entity_Id) return Boolean is
5135 return Is_Record_Type (T1)
5136 or else (Is_Private_Type (T1) and then Has_Discriminants (T1))
5137 or else (Is_Task_Type (T1) and then Has_Discriminants (T1));
5140 -- Start of processing for Is_Appropriate_For_Record
5145 and then (Has_Components (T)
5146 or else (Is_Access_Type (T)
5148 Has_Components (Designated_Type (T))));
5149 end Is_Appropriate_For_Record;
5155 procedure New_Scope (S : Entity_Id) is
5159 if Ekind (S) = E_Void then
5162 -- Set scope depth if not a non-concurrent type, and we have not
5163 -- yet set the scope depth. This means that we have the first
5164 -- occurrence of the scope, and this is where the depth is set.
5166 elsif (not Is_Type (S) or else Is_Concurrent_Type (S))
5167 and then not Scope_Depth_Set (S)
5169 if S = Standard_Standard then
5170 Set_Scope_Depth_Value (S, Uint_0);
5172 elsif Is_Child_Unit (S) then
5173 Set_Scope_Depth_Value (S, Uint_1);
5175 elsif not Is_Record_Type (Current_Scope) then
5176 if Ekind (S) = E_Loop then
5177 Set_Scope_Depth_Value (S, Scope_Depth (Current_Scope));
5179 Set_Scope_Depth_Value (S, Scope_Depth (Current_Scope) + 1);
5184 Scope_Stack.Increment_Last;
5187 SST : Scope_Stack_Entry renames Scope_Stack.Table (Scope_Stack.Last);
5191 SST.Save_Scope_Suppress := Scope_Suppress;
5192 SST.Save_Local_Entity_Suppress := Local_Entity_Suppress.Last;
5194 if Scope_Stack.Last > Scope_Stack.First then
5195 SST.Component_Alignment_Default := Scope_Stack.Table
5196 (Scope_Stack.Last - 1).
5197 Component_Alignment_Default;
5200 SST.Last_Subprogram_Name := null;
5201 SST.Is_Transient := False;
5202 SST.Node_To_Be_Wrapped := Empty;
5203 SST.Pending_Freeze_Actions := No_List;
5204 SST.Actions_To_Be_Wrapped_Before := No_List;
5205 SST.Actions_To_Be_Wrapped_After := No_List;
5206 SST.First_Use_Clause := Empty;
5207 SST.Is_Active_Stack_Base := False;
5210 if Debug_Flag_W then
5211 Write_Str ("--> new scope: ");
5212 Write_Name (Chars (Current_Scope));
5213 Write_Str (", Id=");
5214 Write_Int (Int (Current_Scope));
5215 Write_Str (", Depth=");
5216 Write_Int (Int (Scope_Stack.Last));
5220 -- Copy from Scope (S) the categorization flags to S, this is not
5221 -- done in case Scope (S) is Standard_Standard since propagation
5222 -- is from library unit entity inwards.
5224 if S /= Standard_Standard
5225 and then Scope (S) /= Standard_Standard
5226 and then not Is_Child_Unit (S)
5230 if Nkind (E) not in N_Entity then
5234 -- We only propagate inwards for library level entities,
5235 -- inner level subprograms do not inherit the categorization.
5237 if Is_Library_Level_Entity (S) then
5238 Set_Is_Preelaborated (S, Is_Preelaborated (E));
5239 Set_Is_Shared_Passive (S, Is_Shared_Passive (E));
5240 Set_Categorization_From_Scope (E => S, Scop => E);
5249 procedure Pop_Scope is
5250 SST : Scope_Stack_Entry renames Scope_Stack.Table (Scope_Stack.Last);
5253 if Debug_Flag_E then
5257 Scope_Suppress := SST.Save_Scope_Suppress;
5258 Local_Entity_Suppress.Set_Last (SST.Save_Local_Entity_Suppress);
5260 if Debug_Flag_W then
5261 Write_Str ("--> exiting scope: ");
5262 Write_Name (Chars (Current_Scope));
5263 Write_Str (", Depth=");
5264 Write_Int (Int (Scope_Stack.Last));
5268 End_Use_Clauses (SST.First_Use_Clause);
5270 -- If the actions to be wrapped are still there they will get lost
5271 -- causing incomplete code to be generated. It is better to abort in
5272 -- this case (and we do the abort even with assertions off since the
5273 -- penalty is incorrect code generation)
5275 if SST.Actions_To_Be_Wrapped_Before /= No_List
5277 SST.Actions_To_Be_Wrapped_After /= No_List
5282 -- Free last subprogram name if allocated, and pop scope
5284 Free (SST.Last_Subprogram_Name);
5285 Scope_Stack.Decrement_Last;
5288 ---------------------
5289 -- Premature_Usage --
5290 ---------------------
5292 procedure Premature_Usage (N : Node_Id) is
5293 Kind : constant Node_Kind := Nkind (Parent (Entity (N)));
5294 E : Entity_Id := Entity (N);
5297 -- Within an instance, the analysis of the actual for a formal object
5298 -- does not see the name of the object itself. This is significant
5299 -- only if the object is an aggregate, where its analysis does not do
5300 -- any name resolution on component associations. (see 4717-008). In
5301 -- such a case, look for the visible homonym on the chain.
5304 and then Present (Homonym (E))
5309 and then not In_Open_Scopes (Scope (E))
5316 Set_Etype (N, Etype (E));
5321 if Kind = N_Component_Declaration then
5323 ("component&! cannot be used before end of record declaration", N);
5325 elsif Kind = N_Parameter_Specification then
5327 ("formal parameter&! cannot be used before end of specification",
5330 elsif Kind = N_Discriminant_Specification then
5332 ("discriminant&! cannot be used before end of discriminant part",
5335 elsif Kind = N_Procedure_Specification
5336 or else Kind = N_Function_Specification
5339 ("subprogram&! cannot be used before end of its declaration",
5343 ("object& cannot be used before end of its declaration!", N);
5345 end Premature_Usage;
5347 ------------------------
5348 -- Present_System_Aux --
5349 ------------------------
5351 function Present_System_Aux (N : Node_Id := Empty) return Boolean is
5354 Unum : Unit_Number_Type;
5359 function Find_System (C_Unit : Node_Id) return Entity_Id;
5360 -- Scan context clause of compilation unit to find a with_clause
5367 function Find_System (C_Unit : Node_Id) return Entity_Id is
5368 With_Clause : Node_Id;
5371 With_Clause := First (Context_Items (C_Unit));
5373 while Present (With_Clause) loop
5374 if (Nkind (With_Clause) = N_With_Clause
5375 and then Chars (Name (With_Clause)) = Name_System)
5376 and then Comes_From_Source (With_Clause)
5387 -- Start of processing for Present_System_Aux
5390 -- The child unit may have been loaded and analyzed already
5392 if Present (System_Aux_Id) then
5395 -- If no previous pragma for System.Aux, nothing to load
5397 elsif No (System_Extend_Unit) then
5400 -- Use the unit name given in the pragma to retrieve the unit.
5401 -- Verify that System itself appears in the context clause of the
5402 -- current compilation. If System is not present, an error will
5403 -- have been reported already.
5406 With_Sys := Find_System (Cunit (Current_Sem_Unit));
5408 The_Unit := Unit (Cunit (Current_Sem_Unit));
5411 and then (Nkind (The_Unit) = N_Package_Body
5412 or else (Nkind (The_Unit) = N_Subprogram_Body
5413 and then not Acts_As_Spec (Cunit (Current_Sem_Unit))))
5415 With_Sys := Find_System (Library_Unit (Cunit (Current_Sem_Unit)));
5419 and then Present (N)
5421 -- If we are compiling a subunit, we need to examine its
5422 -- context as well (Current_Sem_Unit is the parent unit);
5424 The_Unit := Parent (N);
5426 while Nkind (The_Unit) /= N_Compilation_Unit loop
5427 The_Unit := Parent (The_Unit);
5430 if Nkind (Unit (The_Unit)) = N_Subunit then
5431 With_Sys := Find_System (The_Unit);
5435 if No (With_Sys) then
5439 Loc := Sloc (With_Sys);
5440 Get_Name_String (Chars (Expression (System_Extend_Unit)));
5441 Name_Buffer (8 .. Name_Len + 7) := Name_Buffer (1 .. Name_Len);
5442 Name_Buffer (1 .. 7) := "system.";
5443 Name_Buffer (Name_Len + 8) := '%';
5444 Name_Buffer (Name_Len + 9) := 's';
5445 Name_Len := Name_Len + 9;
5446 Aux_Name := Name_Find;
5450 (Load_Name => Aux_Name,
5453 Error_Node => With_Sys);
5455 if Unum /= No_Unit then
5456 Semantics (Cunit (Unum));
5458 Defining_Entity (Specification (Unit (Cunit (Unum))));
5460 Withn := Make_With_Clause (Loc,
5462 Make_Expanded_Name (Loc,
5463 Chars => Chars (System_Aux_Id),
5465 New_Reference_To (Scope (System_Aux_Id), Loc),
5467 New_Reference_To (System_Aux_Id, Loc)));
5469 Set_Entity (Name (Withn), System_Aux_Id);
5471 Set_Library_Unit (Withn, Cunit (Unum));
5472 Set_Corresponding_Spec (Withn, System_Aux_Id);
5473 Set_First_Name (Withn, True);
5474 Set_Implicit_With (Withn, True);
5476 Insert_After (With_Sys, Withn);
5477 Mark_Rewrite_Insertion (Withn);
5478 Set_Context_Installed (Withn);
5482 -- Here if unit load failed
5485 Error_Msg_Name_1 := Name_System;
5486 Error_Msg_Name_2 := Chars (Expression (System_Extend_Unit));
5488 ("extension package `%.%` does not exist",
5489 Opt.System_Extend_Unit);
5493 end Present_System_Aux;
5495 -------------------------
5496 -- Restore_Scope_Stack --
5497 -------------------------
5499 procedure Restore_Scope_Stack (Handle_Use : Boolean := True) is
5502 Comp_Unit : Node_Id;
5503 In_Child : Boolean := False;
5504 Full_Vis : Boolean := True;
5505 SS_Last : constant Int := Scope_Stack.Last;
5508 -- Restore visibility of previous scope stack, if any
5510 for J in reverse 0 .. Scope_Stack.Last loop
5511 exit when Scope_Stack.Table (J).Entity = Standard_Standard
5512 or else No (Scope_Stack.Table (J).Entity);
5514 S := Scope_Stack.Table (J).Entity;
5516 if not Is_Hidden_Open_Scope (S) then
5518 -- If the parent scope is hidden, its entities are hidden as
5519 -- well, unless the entity is the instantiation currently
5522 if not Is_Hidden_Open_Scope (Scope (S))
5523 or else not Analyzed (Parent (S))
5524 or else Scope (S) = Standard_Standard
5526 Set_Is_Immediately_Visible (S, True);
5529 E := First_Entity (S);
5531 while Present (E) loop
5532 if Is_Child_Unit (E) then
5533 Set_Is_Immediately_Visible (E,
5534 Is_Visible_Child_Unit (E) or else In_Open_Scopes (E));
5536 Set_Is_Immediately_Visible (E, True);
5541 if not Full_Vis then
5542 exit when E = First_Private_Entity (S);
5546 -- The visibility of child units (siblings of current compilation)
5547 -- must be restored in any case. Their declarations may appear
5548 -- after the private part of the parent.
5551 and then Present (E)
5553 while Present (E) loop
5554 if Is_Child_Unit (E) then
5555 Set_Is_Immediately_Visible (E,
5556 Is_Visible_Child_Unit (E) or else In_Open_Scopes (E));
5564 if Is_Child_Unit (S)
5565 and not In_Child -- check only for current unit.
5569 -- restore visibility of parents according to whether the child
5570 -- is private and whether we are in its visible part.
5572 Comp_Unit := Parent (Unit_Declaration_Node (S));
5574 if Nkind (Comp_Unit) = N_Compilation_Unit
5575 and then Private_Present (Comp_Unit)
5579 elsif (Ekind (S) = E_Package
5580 or else Ekind (S) = E_Generic_Package)
5581 and then (In_Private_Part (S)
5582 or else In_Package_Body (S))
5586 elsif (Ekind (S) = E_Procedure
5587 or else Ekind (S) = E_Function)
5588 and then Has_Completion (S)
5599 if SS_Last >= Scope_Stack.First
5600 and then Scope_Stack.Table (SS_Last).Entity /= Standard_Standard
5603 Install_Use_Clauses (Scope_Stack.Table (SS_Last).First_Use_Clause);
5605 end Restore_Scope_Stack;
5607 ----------------------
5608 -- Save_Scope_Stack --
5609 ----------------------
5611 procedure Save_Scope_Stack (Handle_Use : Boolean := True) is
5614 SS_Last : constant Int := Scope_Stack.Last;
5617 if SS_Last >= Scope_Stack.First
5618 and then Scope_Stack.Table (SS_Last).Entity /= Standard_Standard
5621 End_Use_Clauses (Scope_Stack.Table (SS_Last).First_Use_Clause);
5624 -- If the call is from within a compilation unit, as when
5625 -- called from Rtsfind, make current entries in scope stack
5626 -- invisible while we analyze the new unit.
5628 for J in reverse 0 .. SS_Last loop
5629 exit when Scope_Stack.Table (J).Entity = Standard_Standard
5630 or else No (Scope_Stack.Table (J).Entity);
5632 S := Scope_Stack.Table (J).Entity;
5633 Set_Is_Immediately_Visible (S, False);
5634 E := First_Entity (S);
5636 while Present (E) loop
5637 Set_Is_Immediately_Visible (E, False);
5643 end Save_Scope_Stack;
5649 procedure Set_Use (L : List_Id) is
5651 Pack_Name : Node_Id;
5659 while Present (Decl) loop
5660 if Nkind (Decl) = N_Use_Package_Clause then
5661 Chain_Use_Clause (Decl);
5662 Pack_Name := First (Names (Decl));
5664 while Present (Pack_Name) loop
5665 Pack := Entity (Pack_Name);
5667 if Ekind (Pack) = E_Package
5668 and then Applicable_Use (Pack_Name)
5670 Use_One_Package (Pack, Decl);
5676 elsif Nkind (Decl) = N_Use_Type_Clause then
5677 Chain_Use_Clause (Decl);
5678 Id := First (Subtype_Marks (Decl));
5680 while Present (Id) loop
5681 if Entity (Id) /= Any_Type then
5694 ---------------------
5695 -- Use_One_Package --
5696 ---------------------
5698 procedure Use_One_Package (P : Entity_Id; N : Node_Id) is
5701 Current_Instance : Entity_Id := Empty;
5703 Private_With_OK : Boolean := False;
5706 if Ekind (P) /= E_Package then
5712 -- Ada 2005 (AI-50217): Check restriction
5714 if From_With_Type (P) then
5715 Error_Msg_N ("limited withed package cannot appear in use clause", N);
5718 -- Find enclosing instance, if any
5721 Current_Instance := Current_Scope;
5723 while not Is_Generic_Instance (Current_Instance) loop
5724 Current_Instance := Scope (Current_Instance);
5727 if No (Hidden_By_Use_Clause (N)) then
5728 Set_Hidden_By_Use_Clause (N, New_Elmt_List);
5732 -- If unit is a package renaming, indicate that the renamed
5733 -- package is also in use (the flags on both entities must
5734 -- remain consistent, and a subsequent use of either of them
5735 -- should be recognized as redundant).
5737 if Present (Renamed_Object (P)) then
5738 Set_In_Use (Renamed_Object (P));
5739 Real_P := Renamed_Object (P);
5744 -- Ada 2005 (AI-262): Check the use_clause of a private withed package
5745 -- found in the private part of a package specification
5747 if In_Private_Part (Current_Scope)
5748 and then Has_Private_With (P)
5749 and then Is_Child_Unit (Current_Scope)
5750 and then Is_Child_Unit (P)
5751 and then Is_Ancestor_Package (Scope (Current_Scope), P)
5753 Private_With_OK := True;
5756 -- Loop through entities in one package making them potentially
5759 Id := First_Entity (P);
5761 and then (Id /= First_Private_Entity (P)
5762 or else Private_With_OK) -- Ada 2005 (AI-262)
5764 Prev := Current_Entity (Id);
5766 while Present (Prev) loop
5767 if Is_Immediately_Visible (Prev)
5768 and then (not Is_Overloadable (Prev)
5769 or else not Is_Overloadable (Id)
5770 or else (Type_Conformant (Id, Prev)))
5772 if No (Current_Instance) then
5774 -- Potentially use-visible entity remains hidden
5776 goto Next_Usable_Entity;
5778 -- A use clause within an instance hides outer global
5779 -- entities, which are not used to resolve local entities
5780 -- in the instance. Note that the predefined entities in
5781 -- Standard could not have been hidden in the generic by
5782 -- a use clause, and therefore remain visible. Other
5783 -- compilation units whose entities appear in Standard must
5784 -- be hidden in an instance.
5786 -- To determine whether an entity is external to the instance
5787 -- we compare the scope depth of its scope with that of the
5788 -- current instance. However, a generic actual of a subprogram
5789 -- instance is declared in the wrapper package but will not be
5790 -- hidden by a use-visible entity.
5792 -- If Id is called Standard, the predefined package with the
5793 -- same name is in the homonym chain. It has to be ignored
5794 -- because it has no defined scope (being the only entity in
5795 -- the system with this mandated behavior).
5797 elsif not Is_Hidden (Id)
5798 and then Present (Scope (Prev))
5799 and then not Is_Wrapper_Package (Scope (Prev))
5800 and then Scope_Depth (Scope (Prev)) <
5801 Scope_Depth (Current_Instance)
5802 and then (Scope (Prev) /= Standard_Standard
5803 or else Sloc (Prev) > Standard_Location)
5805 Set_Is_Potentially_Use_Visible (Id);
5806 Set_Is_Immediately_Visible (Prev, False);
5807 Append_Elmt (Prev, Hidden_By_Use_Clause (N));
5810 -- A user-defined operator is not use-visible if the
5811 -- predefined operator for the type is immediately visible,
5812 -- which is the case if the type of the operand is in an open
5813 -- scope. This does not apply to user-defined operators that
5814 -- have operands of different types, because the predefined
5815 -- mixed mode operations (multiplication and division) apply to
5816 -- universal types and do not hide anything.
5818 elsif Ekind (Prev) = E_Operator
5819 and then Operator_Matches_Spec (Prev, Id)
5820 and then In_Open_Scopes
5821 (Scope (Base_Type (Etype (First_Formal (Id)))))
5822 and then (No (Next_Formal (First_Formal (Id)))
5823 or else Etype (First_Formal (Id))
5824 = Etype (Next_Formal (First_Formal (Id)))
5825 or else Chars (Prev) = Name_Op_Expon)
5827 goto Next_Usable_Entity;
5830 Prev := Homonym (Prev);
5833 -- On exit, we know entity is not hidden, unless it is private
5835 if not Is_Hidden (Id)
5836 and then ((not Is_Child_Unit (Id))
5837 or else Is_Visible_Child_Unit (Id))
5839 Set_Is_Potentially_Use_Visible (Id);
5841 if Is_Private_Type (Id)
5842 and then Present (Full_View (Id))
5844 Set_Is_Potentially_Use_Visible (Full_View (Id));
5848 <<Next_Usable_Entity>>
5852 -- Child units are also made use-visible by a use clause, but they
5853 -- may appear after all visible declarations in the parent entity list.
5855 while Present (Id) loop
5857 if Is_Child_Unit (Id)
5858 and then Is_Visible_Child_Unit (Id)
5860 Set_Is_Potentially_Use_Visible (Id);
5866 if Chars (Real_P) = Name_System
5867 and then Scope (Real_P) = Standard_Standard
5868 and then Present_System_Aux (N)
5870 Use_One_Package (System_Aux_Id, N);
5873 end Use_One_Package;
5879 procedure Use_One_Type (Id : Node_Id) is
5885 -- It is the type determined by the subtype mark (8.4(8)) whose
5886 -- operations become potentially use-visible.
5888 T := Base_Type (Entity (Id));
5893 or else Is_Potentially_Use_Visible (T)
5894 or else In_Use (Scope (T)));
5896 if In_Open_Scopes (Scope (T)) then
5899 -- If the subtype mark designates a subtype in a different package,
5900 -- we have to check that the parent type is visible, otherwise the
5901 -- use type clause is a noop. Not clear how to do that???
5903 elsif not Redundant_Use (Id) then
5905 Op_List := Collect_Primitive_Operations (T);
5906 Elmt := First_Elmt (Op_List);
5908 while Present (Elmt) loop
5910 if (Nkind (Node (Elmt)) = N_Defining_Operator_Symbol
5911 or else Chars (Node (Elmt)) in Any_Operator_Name)
5912 and then not Is_Hidden (Node (Elmt))
5914 Set_Is_Potentially_Use_Visible (Node (Elmt));
5926 procedure Write_Info is
5927 Id : Entity_Id := First_Entity (Current_Scope);
5930 -- No point in dumping standard entities
5932 if Current_Scope = Standard_Standard then
5936 Write_Str ("========================================================");
5938 Write_Str (" Defined Entities in ");
5939 Write_Name (Chars (Current_Scope));
5941 Write_Str ("========================================================");
5945 Write_Str ("-- none --");
5949 while Present (Id) loop
5950 Write_Entity_Info (Id, " ");
5955 if Scope (Current_Scope) = Standard_Standard then
5957 -- Print information on the current unit itself
5959 Write_Entity_Info (Current_Scope, " ");
5969 procedure Write_Scopes is
5973 for J in reverse 1 .. Scope_Stack.Last loop
5974 S := Scope_Stack.Table (J).Entity;
5975 Write_Int (Int (S));
5976 Write_Str (" === ");
5977 Write_Name (Chars (S));
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