1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
11 -- Copyright (C) 1992-2001, Free Software Foundation, Inc. --
13 -- GNAT is free software; you can redistribute it and/or modify it under --
14 -- terms of the GNU General Public License as published by the Free Soft- --
15 -- ware Foundation; either version 2, or (at your option) any later ver- --
16 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
17 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
18 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
19 -- for more details. You should have received a copy of the GNU General --
20 -- Public License distributed with GNAT; see file COPYING. If not, write --
21 -- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, --
22 -- MA 02111-1307, USA. --
24 -- GNAT was originally developed by the GNAT team at New York University. --
25 -- It is now maintained by Ada Core Technologies Inc (http://www.gnat.com). --
27 ------------------------------------------------------------------------------
29 with Atree; use Atree;
30 with Debug; use Debug;
31 with Einfo; use Einfo;
32 with Elists; use Elists;
33 with Errout; use Errout;
34 with Exp_Util; use Exp_Util;
35 with Fname; use Fname;
36 with Freeze; use Freeze;
38 with Lib.Load; use Lib.Load;
39 with Lib.Xref; use Lib.Xref;
40 with Namet; use Namet;
41 with Nlists; use Nlists;
42 with Nmake; use Nmake;
44 with Output; use Output;
45 with Restrict; use Restrict;
46 with Rtsfind; use Rtsfind;
48 with Sem_Ch3; use Sem_Ch3;
49 with Sem_Ch4; use Sem_Ch4;
50 with Sem_Ch6; use Sem_Ch6;
51 with Sem_Ch12; use Sem_Ch12;
52 with Sem_Res; use Sem_Res;
53 with Sem_Util; use Sem_Util;
54 with Sem_Type; use Sem_Type;
55 with Stand; use Stand;
56 with Sinfo; use Sinfo;
57 with Sinfo.CN; use Sinfo.CN;
58 with Snames; use Snames;
59 with Style; use Style;
61 with Tbuild; use Tbuild;
62 with Uintp; use Uintp;
64 with GNAT.Spelling_Checker; use GNAT.Spelling_Checker;
66 package body Sem_Ch8 is
68 ------------------------------------
69 -- Visibility and Name Resolution --
70 ------------------------------------
72 -- This package handles name resolution and the collection of
73 -- interpretations for overloaded names, prior to overload resolution.
75 -- Name resolution is the process that establishes a mapping between source
76 -- identifiers and the entities they denote at each point in the program.
77 -- Each entity is represented by a defining occurrence. Each identifier
78 -- that denotes an entity points to the corresponding defining occurrence.
79 -- This is the entity of the applied occurrence. Each occurrence holds
80 -- an index into the names table, where source identifiers are stored.
82 -- Each entry in the names table for an identifier or designator uses the
83 -- Info pointer to hold a link to the currently visible entity that has
84 -- this name (see subprograms Get_Name_Entity_Id and Set_Name_Entity_Id
85 -- in package Sem_Util). The visibility is initialized at the beginning of
86 -- semantic processing to make entities in package Standard immediately
87 -- visible. The visibility table is used in a more subtle way when
88 -- compiling subunits (see below).
90 -- Entities that have the same name (i.e. homonyms) are chained. In the
91 -- case of overloaded entities, this chain holds all the possible meanings
92 -- of a given identifier. The process of overload resolution uses type
93 -- information to select from this chain the unique meaning of a given
96 -- Entities are also chained in their scope, through the Next_Entity link.
97 -- As a consequence, the name space is organized as a sparse matrix, where
98 -- each row corresponds to a scope, and each column to a source identifier.
99 -- Open scopes, that is to say scopes currently being compiled, have their
100 -- corresponding rows of entities in order, innermost scope first.
102 -- The scopes of packages that are mentioned in context clauses appear in
103 -- no particular order, interspersed among open scopes. This is because
104 -- in the course of analyzing the context of a compilation, a package
105 -- declaration is first an open scope, and subsequently an element of the
106 -- context. If subunits or child units are present, a parent unit may
107 -- appear under various guises at various times in the compilation.
109 -- When the compilation of the innermost scope is complete, the entities
110 -- defined therein are no longer visible. If the scope is not a package
111 -- declaration, these entities are never visible subsequently, and can be
112 -- removed from visibility chains. If the scope is a package declaration,
113 -- its visible declarations may still be accessible. Therefore the entities
114 -- defined in such a scope are left on the visibility chains, and only
115 -- their visibility (immediately visibility or potential use-visibility)
118 -- The ordering of homonyms on their chain does not necessarily follow
119 -- the order of their corresponding scopes on the scope stack. For
120 -- example, if package P and the enclosing scope both contain entities
121 -- named E, then when compiling the package body the chain for E will
122 -- hold the global entity first, and the local one (corresponding to
123 -- the current inner scope) next. As a result, name resolution routines
124 -- do not assume any relative ordering of the homonym chains, either
125 -- for scope nesting or to order of appearance of context clauses.
127 -- When compiling a child unit, entities in the parent scope are always
128 -- immediately visible. When compiling the body of a child unit, private
129 -- entities in the parent must also be made immediately visible. There
130 -- are separate routines to make the visible and private declarations
131 -- visible at various times (see package Sem_Ch7).
133 -- +--------+ +-----+
134 -- | In use |-------->| EU1 |-------------------------->
135 -- +--------+ +-----+
137 -- +--------+ +-----+ +-----+
138 -- | Stand. |---------------->| ES1 |--------------->| ES2 |--->
139 -- +--------+ +-----+ +-----+
141 -- +---------+ | +-----+
142 -- | with'ed |------------------------------>| EW2 |--->
143 -- +---------+ | +-----+
145 -- +--------+ +-----+ +-----+
146 -- | Scope2 |---------------->| E12 |--------------->| E22 |--->
147 -- +--------+ +-----+ +-----+
149 -- +--------+ +-----+ +-----+
150 -- | Scope1 |---------------->| E11 |--------------->| E12 |--->
151 -- +--------+ +-----+ +-----+
155 -- | | with'ed |----------------------------------------->
159 -- (innermost first) | |
160 -- +----------------------------+
161 -- Names table => | Id1 | | | | Id2 |
162 -- +----------------------------+
164 -- Name resolution must deal with several syntactic forms: simple names,
165 -- qualified names, indexed names, and various forms of calls.
167 -- Each identifier points to an entry in the names table. The resolution
168 -- of a simple name consists in traversing the homonym chain, starting
169 -- from the names table. If an entry is immediately visible, it is the one
170 -- designated by the identifier. If only potemtially use-visible entities
171 -- are on the chain, we must verify that they do not hide each other. If
172 -- the entity we find is overloadable, we collect all other overloadable
173 -- entities on the chain as long as they are not hidden.
175 -- To resolve expanded names, we must find the entity at the intersection
176 -- of the entity chain for the scope (the prefix) and the homonym chain
177 -- for the selector. In general, homonym chains will be much shorter than
178 -- entity chains, so it is preferable to start from the names table as
179 -- well. If the entity found is overloadable, we must collect all other
180 -- interpretations that are defined in the scope denoted by the prefix.
182 -- For records, protected types, and tasks, their local entities are
183 -- removed from visibility chains on exit from the corresponding scope.
184 -- From the outside, these entities are always accessed by selected
185 -- notation, and the entity chain for the record type, protected type,
186 -- etc. is traversed sequentially in order to find the designated entity.
188 -- The discriminants of a type and the operations of a protected type or
189 -- task are unchained on exit from the first view of the type, (such as
190 -- a private or incomplete type declaration, or a protected type speci-
191 -- fication) and rechained when compiling the second view.
193 -- In the case of operators, we do not make operators on derived types
194 -- explicit. As a result, the notation P."+" may denote either a user-
195 -- defined function with name "+", or else an implicit declaration of the
196 -- operator "+" in package P. The resolution of expanded names always
197 -- tries to resolve an operator name as such an implicitly defined entity,
198 -- in addition to looking for explicit declarations.
200 -- All forms of names that denote entities (simple names, expanded names,
201 -- character literals in some cases) have a Entity attribute, which
202 -- identifies the entity denoted by the name.
204 ---------------------
205 -- The Scope Stack --
206 ---------------------
208 -- The Scope stack keeps track of the scopes currently been compiled.
209 -- Every entity that contains declarations (including records) is placed
210 -- on the scope stack while it is being processed, and removed at the end.
211 -- Whenever a non-package scope is exited, the entities defined therein
212 -- are removed from the visibility table, so that entities in outer scopes
213 -- become visible (see previous description). On entry to Sem, the scope
214 -- stack only contains the package Standard. As usual, subunits complicate
215 -- this picture ever so slightly.
217 -- The Rtsfind mechanism can force a call to Semantics while another
218 -- compilation is in progress. The unit retrieved by Rtsfind must be
219 -- compiled in its own context, and has no access to the visibility of
220 -- the unit currently being compiled. The procedures Save_Scope_Stack and
221 -- Restore_Scope_Stack make entities in current open scopes invisible
222 -- before compiling the retrieved unit, and restore the compilation
223 -- environment afterwards.
225 ------------------------
226 -- Compiling subunits --
227 ------------------------
229 -- Subunits must be compiled in the environment of the corresponding
230 -- stub, that is to say with the same visibility into the parent (and its
231 -- context) that is available at the point of the stub declaration, but
232 -- with the additional visibility provided by the context clause of the
233 -- subunit itself. As a result, compilation of a subunit forces compilation
234 -- of the parent (see description in lib-). At the point of the stub
235 -- declaration, Analyze is called recursively to compile the proper body
236 -- of the subunit, but without reinitializing the names table, nor the
237 -- scope stack (i.e. standard is not pushed on the stack). In this fashion
238 -- the context of the subunit is added to the context of the parent, and
239 -- the subunit is compiled in the correct environment. Note that in the
240 -- course of processing the context of a subunit, Standard will appear
241 -- twice on the scope stack: once for the parent of the subunit, and
242 -- once for the unit in the context clause being compiled. However, the
243 -- two sets of entities are not linked by homonym chains, so that the
244 -- compilation of any context unit happens in a fresh visibility
247 -------------------------------
248 -- Processing of USE Clauses --
249 -------------------------------
251 -- Every defining occurrence has a flag indicating if it is potentially use
252 -- visible. Resolution of simple names examines this flag. The processing
253 -- of use clauses consists in setting this flag on all visible entities
254 -- defined in the corresponding package. On exit from the scope of the use
255 -- clause, the corresponding flag must be reset. However, a package may
256 -- appear in several nested use clauses (pathological but legal, alas!)
257 -- which forces us to use a slightly more involved scheme:
259 -- a) The defining occurrence for a package holds a flag -In_Use- to
260 -- indicate that it is currently in the scope of a use clause. If a
261 -- redundant use clause is encountered, then the corresponding occurrence
262 -- of the package name is flagged -Redundant_Use-.
264 -- b) On exit from a scope, the use clauses in its declarative part are
265 -- scanned. The visibility flag is reset in all entities declared in
266 -- package named in a use clause, as long as the package is not flagged
267 -- as being in a redundant use clause (in which case the outer use
268 -- clause is still in effect, and the direct visibility of its entities
269 -- must be retained).
271 -- Note that entities are not removed from their homonym chains on exit
272 -- from the package specification. A subsequent use clause does not need
273 -- to rechain the visible entities, but only to establish their direct
276 -----------------------------------
277 -- Handling private declarations --
278 -----------------------------------
280 -- The principle that each entity has a single defining occurrence clashes
281 -- with the presence of two separate definitions for private types: the
282 -- first is the private type declaration, and second is the full type
283 -- declaration. It is important that all references to the type point to
284 -- the same defining occurrence, namely the first one. To enforce the two
285 -- separate views of the entity, the corresponding information is swapped
286 -- between the two declarations. Outside of the package, the defining
287 -- occurrence only contains the private declaration information, while in
288 -- the private part and the body of the package the defining occurrence
289 -- contains the full declaration. To simplify the swap, the defining
290 -- occurrence that currently holds the private declaration points to the
291 -- full declaration. During semantic processing the defining occurrence
292 -- also points to a list of private dependents, that is to say access
293 -- types or composite types whose designated types or component types are
294 -- subtypes or derived types of the private type in question. After the
295 -- full declaration has been seen, the private dependents are updated to
296 -- indicate that they have full definitions.
298 ------------------------------------
299 -- Handling of Undefined Messages --
300 ------------------------------------
302 -- In normal mode, only the first use of an undefined identifier generates
303 -- a message. The table Urefs is used to record error messages that have
304 -- been issued so that second and subsequent ones do not generate further
305 -- messages. However, the second reference causes text to be added to the
306 -- original undefined message noting "(more references follow)". The
307 -- full error list option (-gnatf) forces messages to be generated for
308 -- every reference and disconnects the use of this table.
310 type Uref_Entry is record
312 -- Node for identifier for which original message was posted. The
313 -- Chars field of this identifier is used to detect later references
314 -- to the same identifier.
317 -- Records error message Id of original undefined message. Reset to
318 -- No_Error_Msg after the second occurrence, where it is used to add
319 -- text to the original message as described above.
322 -- Set if the message is not visible rather than undefined
325 -- Records location of error message. Used to make sure that we do
326 -- not consider a, b : undefined as two separate instances, which
327 -- would otherwise happen, since the parser converts this sequence
328 -- to a : undefined; b : undefined.
332 package Urefs is new Table.Table (
333 Table_Component_Type => Uref_Entry,
334 Table_Index_Type => Nat,
335 Table_Low_Bound => 1,
337 Table_Increment => 100,
338 Table_Name => "Urefs");
340 Candidate_Renaming : Entity_Id;
341 -- Holds a candidate interpretation that appears in a subprogram renaming
342 -- declaration and does not match the given specification, but matches at
343 -- least on the first formal. Allows better error message when given
344 -- specification omits defaulted parameters, a common error.
346 -----------------------
347 -- Local Subprograms --
348 -----------------------
350 procedure Analyze_Generic_Renaming
353 -- Common processing for all three kinds of generic renaming declarations.
354 -- Enter new name and indicate that it renames the generic unit.
356 procedure Analyze_Renamed_Character
360 -- Renamed entity is given by a character literal, which must belong
361 -- to the return type of the new entity. Is_Body indicates whether the
362 -- declaration is a renaming_as_body. If the original declaration has
363 -- already been frozen (because of an intervening body, e.g.) the body of
364 -- the function must be built now. The same applies to the following
365 -- various renaming procedures.
367 procedure Analyze_Renamed_Dereference
371 -- Renamed entity is given by an explicit dereference. Prefix must be a
372 -- conformant access_to_subprogram type.
374 procedure Analyze_Renamed_Entry
378 -- If the renamed entity in a subprogram renaming is an entry or protected
379 -- subprogram, build a body for the new entity whose only statement is a
380 -- call to the renamed entity.
382 procedure Analyze_Renamed_Family_Member
386 -- Used when the renamed entity is an indexed component. The prefix must
387 -- denote an entry family.
389 procedure Attribute_Renaming (N : Node_Id);
390 -- Analyze renaming of attribute as function. The renaming declaration N
391 -- is rewritten as a function body that returns the attribute reference
392 -- applied to the formals of the function.
394 procedure Check_Frozen_Renaming (N : Node_Id; Subp : Entity_Id);
395 -- A renaming_as_body may occur after the entity of the original decla-
396 -- ration has been frozen. In that case, the body of the new entity must
397 -- be built now, because the usual mechanism of building the renamed
398 -- body at the point of freezing will not work. Subp is the subprogram
399 -- for which N provides the Renaming_As_Body.
401 procedure Check_Library_Unit_Renaming (N : Node_Id; Old_E : Entity_Id);
402 -- Verify that the entity in a renaming declaration that is a library unit
403 -- is itself a library unit and not a nested unit or subunit. Also check
404 -- that if the renaming is a child unit of a generic parent, then the
405 -- renamed unit must also be a child unit of that parent. Finally, verify
406 -- that a renamed generic unit is not an implicit child declared within
407 -- an instance of the parent.
409 procedure Chain_Use_Clause (N : Node_Id);
410 -- Chain use clause onto list of uses clauses headed by First_Use_Clause
411 -- in the top scope table entry.
413 function Has_Implicit_Character_Literal (N : Node_Id) return Boolean;
414 -- Find a type derived from Character or Wide_Character in the prefix of N.
415 -- Used to resolved qualified names whose selector is a character literal.
417 function Find_Renamed_Entity
421 Is_Actual : Boolean := False) return Entity_Id;
422 -- Find the renamed entity that corresponds to the given parameter profile
423 -- in a subprogram renaming declaration. The renamed entity may be an
424 -- operator, a subprogram, an entry, or a protected operation. Is_Actual
425 -- indicates that the renaming is the one generated for an actual subpro-
426 -- gram in an instance, for which special visibility checks apply.
428 procedure Inherit_Renamed_Profile (New_S : Entity_Id; Old_S : Entity_Id);
429 -- A subprogram defined by a renaming declaration inherits the parameter
430 -- profile of the renamed entity. The subtypes given in the subprogram
431 -- specification are discarded and replaced with those of the renamed
432 -- subprogram, which are then used to recheck the default values.
434 procedure Premature_Usage (N : Node_Id);
435 -- Diagnose usage of an entity before it is visible.
437 procedure Write_Info;
438 -- Write debugging information on entities declared in current scope
440 procedure Write_Scopes;
441 pragma Warnings (Off, Write_Scopes);
442 -- Debugging information: dump all entities on scope stack
444 --------------------------------
445 -- Analyze_Exception_Renaming --
446 --------------------------------
448 -- The language only allows a single identifier, but the tree holds
449 -- an identifier list. The parser has already issued an error message
450 -- if there is more than one element in the list.
452 procedure Analyze_Exception_Renaming (N : Node_Id) is
453 Id : constant Node_Id := Defining_Identifier (N);
454 Nam : constant Node_Id := Name (N);
460 Set_Ekind (Id, E_Exception);
461 Set_Exception_Code (Id, Uint_0);
462 Set_Etype (Id, Standard_Exception_Type);
463 Set_Is_Pure (Id, Is_Pure (Current_Scope));
465 if not Is_Entity_Name (Nam) or else
466 Ekind (Entity (Nam)) /= E_Exception
468 Error_Msg_N ("invalid exception name in renaming", Nam);
470 if Present (Renamed_Object (Entity (Nam))) then
471 Set_Renamed_Object (Id, Renamed_Object (Entity (Nam)));
473 Set_Renamed_Object (Id, Entity (Nam));
476 end Analyze_Exception_Renaming;
478 ---------------------------
479 -- Analyze_Expanded_Name --
480 ---------------------------
482 procedure Analyze_Expanded_Name (N : Node_Id) is
484 -- If the entity pointer is already set, this is an internal node, or
485 -- a node that is analyzed more than once, after a tree modification.
486 -- In such a case there is no resolution to perform, just set the type.
487 -- For completeness, analyze prefix as well.
489 if Present (Entity (N)) then
490 if Is_Type (Entity (N)) then
491 Set_Etype (N, Entity (N));
493 Set_Etype (N, Etype (Entity (N)));
496 Analyze (Prefix (N));
499 Find_Expanded_Name (N);
501 end Analyze_Expanded_Name;
503 ----------------------------------------
504 -- Analyze_Generic_Function_Renaming --
505 ----------------------------------------
507 procedure Analyze_Generic_Function_Renaming (N : Node_Id) is
509 Analyze_Generic_Renaming (N, E_Generic_Function);
510 end Analyze_Generic_Function_Renaming;
512 ---------------------------------------
513 -- Analyze_Generic_Package_Renaming --
514 ---------------------------------------
516 procedure Analyze_Generic_Package_Renaming (N : Node_Id) is
518 -- Apply the Text_IO Kludge here, since we may be renaming
519 -- one of the subpackages of Text_IO, then join common routine.
521 Text_IO_Kludge (Name (N));
523 Analyze_Generic_Renaming (N, E_Generic_Package);
524 end Analyze_Generic_Package_Renaming;
526 -----------------------------------------
527 -- Analyze_Generic_Procedure_Renaming --
528 -----------------------------------------
530 procedure Analyze_Generic_Procedure_Renaming (N : Node_Id) is
532 Analyze_Generic_Renaming (N, E_Generic_Procedure);
533 end Analyze_Generic_Procedure_Renaming;
535 ------------------------------
536 -- Analyze_Generic_Renaming --
537 ------------------------------
539 procedure Analyze_Generic_Renaming
543 New_P : Entity_Id := Defining_Entity (N);
545 Inst : Boolean := False; -- prevent junk warning
548 if Name (N) = Error then
552 Generate_Definition (New_P);
554 if Current_Scope /= Standard_Standard then
555 Set_Is_Pure (New_P, Is_Pure (Current_Scope));
558 if Nkind (Name (N)) = N_Selected_Component then
559 Check_Generic_Child_Unit (Name (N), Inst);
564 if not Is_Entity_Name (Name (N)) then
565 Error_Msg_N ("expect entity name in renaming declaration", Name (N));
568 Old_P := Entity (Name (N));
572 Set_Ekind (New_P, K);
574 if Etype (Old_P) = Any_Type then
577 elsif Ekind (Old_P) /= K then
578 Error_Msg_N ("invalid generic unit name", Name (N));
581 if Present (Renamed_Object (Old_P)) then
582 Set_Renamed_Object (New_P, Renamed_Object (Old_P));
584 Set_Renamed_Object (New_P, Old_P);
587 Set_Etype (New_P, Etype (Old_P));
588 Set_Has_Completion (New_P);
590 if In_Open_Scopes (Old_P) then
591 Error_Msg_N ("within its scope, generic denotes its instance", N);
594 Check_Library_Unit_Renaming (N, Old_P);
597 end Analyze_Generic_Renaming;
599 -----------------------------
600 -- Analyze_Object_Renaming --
601 -----------------------------
603 procedure Analyze_Object_Renaming (N : Node_Id) is
604 Id : constant Entity_Id := Defining_Identifier (N);
606 Nam : constant Node_Id := Name (N);
607 S : constant Entity_Id := Subtype_Mark (N);
616 Set_Is_Pure (Id, Is_Pure (Current_Scope));
619 -- The renaming of a component that depends on a discriminant
620 -- requires an actual subtype, because in subsequent use of the object
621 -- Gigi will be unable to locate the actual bounds. This explicit step
622 -- is required when the renaming is generated in removing side effects
623 -- of an already-analyzed expression.
625 if Nkind (Nam) = N_Selected_Component
626 and then Analyzed (Nam)
629 Dec := Build_Actual_Subtype_Of_Component (Etype (Nam), Nam);
631 if Present (Dec) then
632 Insert_Action (N, Dec);
633 T := Defining_Identifier (Dec);
640 Analyze_And_Resolve (Nam, T);
643 -- An object renaming requires an exact match of the type;
644 -- class-wide matching is not allowed.
646 if Is_Class_Wide_Type (T)
647 and then Base_Type (Etype (Nam)) /= Base_Type (T)
653 Set_Ekind (Id, E_Variable);
654 Init_Size_Align (Id);
656 if T = Any_Type or else Etype (Nam) = Any_Type then
659 -- Verify that the renamed entity is an object or a function call.
660 -- It may have been rewritten in several ways.
662 elsif Is_Object_Reference (Nam) then
664 if Comes_From_Source (N)
665 and then Is_Dependent_Component_Of_Mutable_Object (Nam)
668 ("illegal renaming of discriminant-dependent component", Nam);
673 -- A static function call may have been folded into a literal
675 elsif Nkind (Original_Node (Nam)) = N_Function_Call
677 -- When expansion is disabled, attribute reference is not
678 -- rewritten as function call. Otherwise it may be rewritten
679 -- as a conversion, so check original node.
681 or else (Nkind (Original_Node (Nam)) = N_Attribute_Reference
682 and then Is_Function_Attribute_Name
683 (Attribute_Name (Original_Node (Nam))))
685 -- Weird but legal, equivalent to renaming a function call.
687 or else (Is_Entity_Name (Nam)
688 and then Ekind (Entity (Nam)) = E_Enumeration_Literal)
690 or else (Nkind (Nam) = N_Type_Conversion
691 and then Is_Tagged_Type (Entity (Subtype_Mark (Nam))))
696 if Nkind (Nam) = N_Type_Conversion then
698 ("renaming of conversion only allowed for tagged types", Nam);
701 Error_Msg_N ("expect object name in renaming", Nam);
708 if not Is_Variable (Nam) then
709 Set_Ekind (Id, E_Constant);
710 Set_Not_Source_Assigned (Id, True);
711 Set_Is_True_Constant (Id, True);
714 Set_Renamed_Object (Id, Nam);
715 end Analyze_Object_Renaming;
717 ------------------------------
718 -- Analyze_Package_Renaming --
719 ------------------------------
721 procedure Analyze_Package_Renaming (N : Node_Id) is
722 New_P : constant Entity_Id := Defining_Entity (N);
727 if Name (N) = Error then
731 -- Apply Text_IO kludge here, since we may be renaming one of
732 -- the children of Text_IO
734 Text_IO_Kludge (Name (N));
736 if Current_Scope /= Standard_Standard then
737 Set_Is_Pure (New_P, Is_Pure (Current_Scope));
742 if Is_Entity_Name (Name (N)) then
743 Old_P := Entity (Name (N));
748 if Etype (Old_P) = Any_Type then
750 ("expect package name in renaming", Name (N));
752 elsif Ekind (Old_P) /= E_Package
753 and then not (Ekind (Old_P) = E_Generic_Package
754 and then In_Open_Scopes (Old_P))
756 if Ekind (Old_P) = E_Generic_Package then
758 ("generic package cannot be renamed as a package", Name (N));
760 Error_Msg_Sloc := Sloc (Old_P);
762 ("expect package name in renaming, found& declared#",
766 -- Set basic attributes to minimize cascaded errors.
768 Set_Ekind (New_P, E_Package);
769 Set_Etype (New_P, Standard_Void_Type);
771 elsif Ekind (Old_P) = E_Package
772 and then From_With_Type (Old_P)
774 Error_Msg_N ("imported package cannot be renamed", Name (N));
777 -- Entities in the old package are accessible through the
778 -- renaming entity. The simplest implementation is to have
779 -- both packages share the entity list.
781 Set_Ekind (New_P, E_Package);
782 Set_Etype (New_P, Standard_Void_Type);
784 if Present (Renamed_Object (Old_P)) then
785 Set_Renamed_Object (New_P, Renamed_Object (Old_P));
787 Set_Renamed_Object (New_P, Old_P);
790 Set_Has_Completion (New_P);
792 Set_First_Entity (New_P, First_Entity (Old_P));
793 Set_Last_Entity (New_P, Last_Entity (Old_P));
794 Set_First_Private_Entity (New_P, First_Private_Entity (Old_P));
795 Check_Library_Unit_Renaming (N, Old_P);
796 Generate_Reference (Old_P, Name (N));
798 -- If this is the renaming declaration of a package instantiation
799 -- within itself, it is the declaration that ends the list of actuals
800 -- for the instantiation. At this point, the subtypes that rename
801 -- the actuals are flagged as generic, to avoid spurious ambiguities
802 -- if the actuals for two distinct formals happen to coincide. If
803 -- the actual is a private type, the subtype has a private completion
804 -- that is flagged in the same fashion.
806 -- Resolution is identical to what is was in the original generic.
807 -- On exit from the generic instance, these are turned into regular
808 -- subtypes again, so they are compatible with types in their class.
810 if not Is_Generic_Instance (Old_P) then
813 Spec := Specification (Unit_Declaration_Node (Old_P));
816 if Nkind (Spec) = N_Package_Specification
817 and then Present (Generic_Parent (Spec))
818 and then Old_P = Current_Scope
819 and then Chars (New_P) = Chars (Generic_Parent (Spec))
822 E : Entity_Id := First_Entity (Old_P);
828 and then Nkind (Parent (E)) = N_Subtype_Declaration
830 Set_Is_Generic_Actual_Type (E);
832 if Is_Private_Type (E)
833 and then Present (Full_View (E))
835 Set_Is_Generic_Actual_Type (Full_View (E));
845 end Analyze_Package_Renaming;
847 -------------------------------
848 -- Analyze_Renamed_Character --
849 -------------------------------
851 procedure Analyze_Renamed_Character
856 C : constant Node_Id := Name (N);
859 if Ekind (New_S) = E_Function then
860 Resolve (C, Etype (New_S));
863 Check_Frozen_Renaming (N, New_S);
867 Error_Msg_N ("character literal can only be renamed as function", N);
869 end Analyze_Renamed_Character;
871 ---------------------------------
872 -- Analyze_Renamed_Dereference --
873 ---------------------------------
875 procedure Analyze_Renamed_Dereference
880 Nam : constant Node_Id := Name (N);
881 P : constant Node_Id := Prefix (Nam);
887 if not Is_Overloaded (P) then
889 if Ekind (Etype (Nam)) /= E_Subprogram_Type
890 or else not Type_Conformant (Etype (Nam), New_S) then
891 Error_Msg_N ("designated type does not match specification", P);
893 Resolve (P, Etype (P));
900 Get_First_Interp (Nam, I, It);
902 while Present (It.Nam) loop
904 if Ekind (It.Nam) = E_Subprogram_Type
905 and then Type_Conformant (It.Nam, New_S) then
907 if Typ /= Any_Id then
908 Error_Msg_N ("ambiguous renaming", P);
915 Get_Next_Interp (I, It);
918 if Typ = Any_Type then
919 Error_Msg_N ("designated type does not match specification", P);
924 Check_Frozen_Renaming (N, New_S);
928 end Analyze_Renamed_Dereference;
930 ---------------------------
931 -- Analyze_Renamed_Entry --
932 ---------------------------
934 procedure Analyze_Renamed_Entry
939 Nam : Node_Id := Name (N);
940 Sel : Node_Id := Selector_Name (Nam);
944 if Entity (Sel) = Any_Id then
946 -- Selector is undefined on prefix. Error emitted already.
948 Set_Has_Completion (New_S);
952 -- Otherwise, find renamed entity, and build body of New_S as a call
955 Old_S := Find_Renamed_Entity (N, Selector_Name (Nam), New_S);
957 if Old_S = Any_Id then
958 Error_Msg_N (" no subprogram or entry matches specification", N);
961 Check_Subtype_Conformant (New_S, Old_S, N);
962 Generate_Reference (New_S, Defining_Entity (N), 'b');
963 Style.Check_Identifier (Defining_Entity (N), New_S);
966 Inherit_Renamed_Profile (New_S, Old_S);
969 Set_Convention (New_S, Convention (Old_S));
970 Set_Has_Completion (New_S, Inside_A_Generic);
973 Check_Frozen_Renaming (N, New_S);
975 end Analyze_Renamed_Entry;
977 -----------------------------------
978 -- Analyze_Renamed_Family_Member --
979 -----------------------------------
981 procedure Analyze_Renamed_Family_Member
986 Nam : Node_Id := Name (N);
987 P : Node_Id := Prefix (Nam);
991 if (Is_Entity_Name (P) and then Ekind (Entity (P)) = E_Entry_Family)
992 or else (Nkind (P) = N_Selected_Component
994 Ekind (Entity (Selector_Name (P))) = E_Entry_Family)
996 if Is_Entity_Name (P) then
999 Old_S := Entity (Selector_Name (P));
1002 if not Entity_Matches_Spec (Old_S, New_S) then
1003 Error_Msg_N ("entry family does not match specification", N);
1006 Check_Subtype_Conformant (New_S, Old_S, N);
1007 Generate_Reference (New_S, Defining_Entity (N), 'b');
1008 Style.Check_Identifier (Defining_Entity (N), New_S);
1011 Error_Msg_N ("no entry family matches specification", N);
1014 Set_Has_Completion (New_S, Inside_A_Generic);
1017 Check_Frozen_Renaming (N, New_S);
1019 end Analyze_Renamed_Family_Member;
1021 ---------------------------------
1022 -- Analyze_Subprogram_Renaming --
1023 ---------------------------------
1025 procedure Analyze_Subprogram_Renaming (N : Node_Id) is
1026 Nam : Node_Id := Name (N);
1027 Spec : constant Node_Id := Specification (N);
1029 Old_S : Entity_Id := Empty;
1030 Rename_Spec : Entity_Id;
1031 Is_Actual : Boolean := False;
1032 Inst_Node : Node_Id := Empty;
1033 Save_83 : Boolean := Ada_83;
1036 -- We must test for the attribute renaming case before the Analyze
1037 -- call because otherwise Sem_Attr will complain that the attribute
1038 -- is missing an argument when it is analyzed.
1040 if Nkind (Nam) = N_Attribute_Reference then
1041 Attribute_Renaming (N);
1045 -- Check whether this declaration corresponds to the instantiation
1046 -- of a formal subprogram. This is indicated by the presence of a
1047 -- Corresponding_Spec that is the instantiation declaration.
1049 -- If this is an instantiation, the corresponding actual is frozen
1050 -- and error messages can be made more precise. If this is a default
1051 -- subprogram, the entity is already established in the generic, and
1052 -- is not retrieved by visibility. If it is a default with a box, the
1053 -- candidate interpretations, if any, have been collected when building
1054 -- the renaming declaration. If overloaded, the proper interpretation
1055 -- is determined in Find_Renamed_Entity. If the entity is an operator,
1056 -- Find_Renamed_Entity applies additional visibility checks.
1058 if Present (Corresponding_Spec (N)) then
1060 Inst_Node := Corresponding_Spec (N);
1062 if Is_Entity_Name (Nam)
1063 and then Present (Entity (Nam))
1064 and then not Comes_From_Source (Nam)
1065 and then not Is_Overloaded (Nam)
1067 Old_S := Entity (Nam);
1068 New_S := Analyze_Spec (Spec);
1070 if Ekind (Entity (Nam)) = E_Operator
1071 and then Box_Present (Corresponding_Spec (N))
1073 Old_S := Find_Renamed_Entity (N, Name (N), New_S, Is_Actual);
1078 New_S := Analyze_Spec (Spec);
1081 Set_Corresponding_Spec (N, Empty);
1084 -- Renamed entity must be analyzed first, to avoid being hidden by
1085 -- new name (which might be the same in a generic instance).
1089 -- The renaming defines a new overloaded entity, which is analyzed
1090 -- like a subprogram declaration.
1092 New_S := Analyze_Spec (Spec);
1095 if Current_Scope /= Standard_Standard then
1096 Set_Is_Pure (New_S, Is_Pure (Current_Scope));
1099 Rename_Spec := Find_Corresponding_Spec (N);
1101 if Present (Rename_Spec) then
1103 -- Renaming_As_Body. Renaming declaration is the completion of
1104 -- the declaration of Rename_Spec. We will build an actual body
1105 -- for it at the freezing point.
1107 Set_Corresponding_Spec (N, Rename_Spec);
1108 Set_Corresponding_Body (Unit_Declaration_Node (Rename_Spec), New_S);
1110 -- The body is created when the entity is frozen. If the context
1111 -- is generic, freeze_all is not invoked, so we need to indicate
1112 -- that the entity has a completion.
1114 Set_Has_Completion (Rename_Spec, Inside_A_Generic);
1116 if Ada_83 and then Comes_From_Source (N) then
1117 Error_Msg_N ("(Ada 83) renaming cannot serve as a body", N);
1120 Set_Convention (New_S, Convention (Rename_Spec));
1121 Check_Fully_Conformant (New_S, Rename_Spec);
1122 Set_Public_Status (New_S);
1124 -- Indicate that the entity in the declaration functions like
1125 -- the corresponding body, and is not a new entity.
1127 Set_Ekind (New_S, E_Subprogram_Body);
1128 New_S := Rename_Spec;
1131 Generate_Definition (New_S);
1132 New_Overloaded_Entity (New_S);
1133 if Is_Entity_Name (Nam)
1134 and then Is_Intrinsic_Subprogram (Entity (Nam))
1138 Check_Delayed_Subprogram (New_S);
1142 -- There is no need for elaboration checks on the new entity, which
1143 -- may be called before the next freezing point where the body will
1146 Set_Suppress_Elaboration_Checks (New_S, True);
1148 if Etype (Nam) = Any_Type then
1149 Set_Has_Completion (New_S);
1152 elsif Nkind (Nam) = N_Selected_Component then
1154 -- Renamed entity is an entry or protected subprogram. For those
1155 -- cases an explicit body is built (at the point of freezing of
1156 -- this entity) that contains a call to the renamed entity.
1158 Analyze_Renamed_Entry (N, New_S, Present (Rename_Spec));
1161 elsif Nkind (Nam) = N_Explicit_Dereference then
1163 -- Renamed entity is designated by access_to_subprogram expression.
1164 -- Must build body to encapsulate call, as in the entry case.
1166 Analyze_Renamed_Dereference (N, New_S, Present (Rename_Spec));
1169 elsif Nkind (Nam) = N_Indexed_Component then
1170 Analyze_Renamed_Family_Member (N, New_S, Present (Rename_Spec));
1173 elsif Nkind (Nam) = N_Character_Literal then
1174 Analyze_Renamed_Character (N, New_S, Present (Rename_Spec));
1177 elsif (not Is_Entity_Name (Nam)
1178 and then Nkind (Nam) /= N_Operator_Symbol)
1179 or else not Is_Overloadable (Entity (Nam))
1181 Error_Msg_N ("expect valid subprogram name in renaming", N);
1186 -- Most common case: subprogram renames subprogram. No body is
1187 -- generated in this case, so we must indicate that the declaration
1188 -- is complete as is.
1190 if No (Rename_Spec) then
1191 Set_Has_Completion (New_S);
1194 -- Find the renamed entity that matches the given specification.
1195 -- Disable Ada_83 because there is no requirement of full conformance
1196 -- between renamed entity and new entity, even though the same circuit
1202 Old_S := Find_Renamed_Entity (N, Name (N), New_S, Is_Actual);
1205 if Old_S /= Any_Id then
1208 and then Box_Present (Inst_Node)
1210 -- This is an implicit reference to the default actual
1212 Generate_Reference (Old_S, Nam, Typ => 'i', Force => True);
1214 Generate_Reference (Old_S, Nam);
1217 -- For a renaming-as-body, require subtype conformance,
1218 -- but if the declaration being completed has not been
1219 -- frozen, then inherit the convention of the renamed
1220 -- subprogram prior to checking conformance (unless the
1221 -- renaming has an explicit convention established; the
1222 -- rule stated in the RM doesn't seem to address this ???).
1224 if Present (Rename_Spec) then
1225 Generate_Reference (Rename_Spec, Defining_Entity (Spec), 'b');
1226 Style.Check_Identifier (Defining_Entity (Spec), Rename_Spec);
1228 if not Is_Frozen (Rename_Spec)
1229 and then not Has_Convention_Pragma (Rename_Spec)
1231 Set_Convention (New_S, Convention (Old_S));
1234 Check_Frozen_Renaming (N, Rename_Spec);
1235 Check_Subtype_Conformant (New_S, Old_S, Spec);
1237 elsif Ekind (Old_S) /= E_Operator then
1238 Check_Mode_Conformant (New_S, Old_S);
1241 and then Error_Posted (New_S)
1243 Error_Msg_NE ("invalid actual subprogram: & #!", N, Old_S);
1247 if No (Rename_Spec) then
1249 -- The parameter profile of the new entity is that of the renamed
1250 -- entity: the subtypes given in the specification are irrelevant.
1252 Inherit_Renamed_Profile (New_S, Old_S);
1254 -- A call to the subprogram is transformed into a call to the
1255 -- renamed entity. This is transitive if the renamed entity is
1256 -- itself a renaming.
1258 if Present (Alias (Old_S)) then
1259 Set_Alias (New_S, Alias (Old_S));
1261 Set_Alias (New_S, Old_S);
1264 -- Note that we do not set Is_Instrinsic_Subprogram if we have
1265 -- a renaming as body, since the entity in this case is not an
1266 -- intrinsic (it calls an intrinsic, but we have a real body
1267 -- for this call, and it is in this body that the required
1268 -- intrinsic processing will take place).
1270 Set_Is_Intrinsic_Subprogram
1271 (New_S, Is_Intrinsic_Subprogram (Old_S));
1273 if Ekind (Alias (New_S)) = E_Operator then
1274 Set_Has_Delayed_Freeze (New_S, False);
1280 and then (Old_S = New_S
1281 or else (Nkind (Nam) /= N_Expanded_Name
1282 and then Chars (Old_S) = Chars (New_S)))
1284 Error_Msg_N ("subprogram cannot rename itself", N);
1287 Set_Convention (New_S, Convention (Old_S));
1288 Set_Is_Abstract (New_S, Is_Abstract (Old_S));
1289 Check_Library_Unit_Renaming (N, Old_S);
1291 -- Pathological case: procedure renames entry in the scope of
1292 -- its task. Entry is given by simple name, but body must be built
1293 -- for procedure. Of course if called it will deadlock.
1295 if Ekind (Old_S) = E_Entry then
1296 Set_Has_Completion (New_S, False);
1297 Set_Alias (New_S, Empty);
1301 Freeze_Before (N, Old_S);
1302 Set_Has_Delayed_Freeze (New_S, False);
1303 Freeze_Before (N, New_S);
1305 if (Ekind (Old_S) = E_Procedure or else Ekind (Old_S) = E_Function)
1306 and then Is_Abstract (Old_S)
1309 ("abstract subprogram not allowed as generic actual", Nam);
1314 -- A common error is to assume that implicit operators for types
1315 -- are defined in Standard, or in the scope of a subtype. In those
1316 -- cases where the renamed entity is given with an expanded name,
1317 -- it is worth mentioning that operators for the type are not
1318 -- declared in the scope given by the prefix.
1320 if Nkind (Nam) = N_Expanded_Name
1321 and then Nkind (Selector_Name (Nam)) = N_Operator_Symbol
1322 and then Scope (Entity (Nam)) = Standard_Standard
1325 T : constant Entity_Id :=
1326 Base_Type (Etype (First_Formal (New_S)));
1329 Error_Msg_Node_2 := Prefix (Nam);
1330 Error_Msg_NE ("\operator for type& is not declared in&",
1335 ("no visible subprogram matches the specification for&",
1339 if Present (Candidate_Renaming) then
1345 F1 := First_Formal (Candidate_Renaming);
1346 F2 := First_Formal (New_S);
1348 while Present (F1) and then Present (F2) loop
1353 if Present (F1) and then Present (Default_Value (F1)) then
1354 if Present (Next_Formal (F1)) then
1356 ("\missing specification for &" &
1357 " and other formals with defaults", Spec, F1);
1360 ("\missing specification for &", Spec, F1);
1368 end Analyze_Subprogram_Renaming;
1370 -------------------------
1371 -- Analyze_Use_Package --
1372 -------------------------
1374 -- Resolve the package names in the use clause, and make all the visible
1375 -- entities defined in the package potentially use-visible. If the package
1376 -- is already in use from a previous use clause, its visible entities are
1377 -- already use-visible. In that case, mark the occurrence as a redundant
1378 -- use. If the package is an open scope, i.e. if the use clause occurs
1379 -- within the package itself, ignore it.
1381 procedure Analyze_Use_Package (N : Node_Id) is
1382 Pack_Name : Node_Id;
1385 function In_Previous_With_Clause (P : Entity_Id) return Boolean;
1386 -- For use clauses in a context clause, the indicated package may
1387 -- be visible and yet illegal, if it did not appear in a previous
1390 -----------------------------
1391 -- In_Previous_With_Clause --
1392 -----------------------------
1394 function In_Previous_With_Clause (P : Entity_Id) return Boolean is
1398 Item := First (Context_Items (Parent (N)));
1400 while Present (Item)
1403 if Nkind (Item) = N_With_Clause
1404 and then Entity (Name (Item)) = Pack
1413 end In_Previous_With_Clause;
1415 -- Start of processing for Analyze_Use_Package
1418 Set_Hidden_By_Use_Clause (N, No_Elist);
1420 -- Use clause is not allowed in a spec of a predefined package
1421 -- declaration except that packages whose file name starts a-n
1422 -- are OK (these are children of Ada.Numerics, and such packages
1423 -- are never loaded by Rtsfind).
1425 if Is_Predefined_File_Name (Unit_File_Name (Current_Sem_Unit))
1426 and then Name_Buffer (1 .. 3) /= "a-n"
1428 Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Declaration
1430 Error_Msg_N ("use clause not allowed in predefined spec", N);
1433 -- Chain clause to list of use clauses in current scope.
1435 if Nkind (Parent (N)) /= N_Compilation_Unit then
1436 Chain_Use_Clause (N);
1439 -- Loop through package names to identify referenced packages
1441 Pack_Name := First (Names (N));
1443 while Present (Pack_Name) loop
1444 Analyze (Pack_Name);
1446 if Nkind (Parent (N)) = N_Compilation_Unit
1447 and then Nkind (Pack_Name) = N_Expanded_Name
1450 Pref : Node_Id := Prefix (Pack_Name);
1453 while Nkind (Pref) = N_Expanded_Name loop
1454 Pref := Prefix (Pref);
1457 if Entity (Pref) = Standard_Standard then
1459 ("predefined package Standard cannot appear"
1460 & " in a context clause", Pref);
1468 -- Loop through package names to mark all entities as potentially
1471 Pack_Name := First (Names (N));
1473 while Present (Pack_Name) loop
1475 if Is_Entity_Name (Pack_Name) then
1476 Pack := Entity (Pack_Name);
1478 if Ekind (Pack) /= E_Package
1479 and then Etype (Pack) /= Any_Type
1481 if Ekind (Pack) = E_Generic_Package then
1483 ("a generic package is not allowed in a use clause",
1486 Error_Msg_N ("& is not a usable package", Pack_Name);
1489 elsif Nkind (Parent (N)) = N_Compilation_Unit
1490 and then Nkind (Pack_Name) /= N_Expanded_Name
1491 and then not In_Previous_With_Clause (Pack)
1493 Error_Msg_N ("package is not directly visible", Pack_Name);
1495 elsif Applicable_Use (Pack_Name) then
1496 Use_One_Package (Pack, N);
1503 end Analyze_Use_Package;
1505 ----------------------
1506 -- Analyze_Use_Type --
1507 ----------------------
1509 procedure Analyze_Use_Type (N : Node_Id) is
1513 Set_Hidden_By_Use_Clause (N, No_Elist);
1515 -- Chain clause to list of use clauses in current scope.
1517 if Nkind (Parent (N)) /= N_Compilation_Unit then
1518 Chain_Use_Clause (N);
1521 Id := First (Subtype_Marks (N));
1523 while Present (Id) loop
1526 if Entity (Id) /= Any_Type then
1527 Use_One_Type (Id, N);
1532 end Analyze_Use_Type;
1534 --------------------
1535 -- Applicable_Use --
1536 --------------------
1538 function Applicable_Use (Pack_Name : Node_Id) return Boolean is
1539 Pack : constant Entity_Id := Entity (Pack_Name);
1542 if In_Open_Scopes (Pack) then
1545 elsif In_Use (Pack) then
1546 Set_Redundant_Use (Pack_Name, True);
1549 elsif Present (Renamed_Object (Pack))
1550 and then In_Use (Renamed_Object (Pack))
1552 Set_Redundant_Use (Pack_Name, True);
1560 ------------------------
1561 -- Attribute_Renaming --
1562 ------------------------
1564 procedure Attribute_Renaming (N : Node_Id) is
1565 Loc : constant Source_Ptr := Sloc (N);
1566 Nam : constant Node_Id := Name (N);
1567 Spec : constant Node_Id := Specification (N);
1568 New_S : constant Entity_Id := Defining_Unit_Name (Spec);
1569 Aname : constant Name_Id := Attribute_Name (Nam);
1571 Form_Num : Nat := 0;
1572 Expr_List : List_Id := No_List;
1574 Attr_Node : Node_Id;
1575 Body_Node : Node_Id;
1576 Param_Spec : Node_Id;
1579 Generate_Definition (New_S);
1581 -- This procedure is called in the context of subprogram renaming,
1582 -- and thus the attribute must be one that is a subprogram. All of
1583 -- those have at least one formal parameter, with the singular
1584 -- exception of AST_Entry (which is a real oddity, it is odd that
1585 -- this can be renamed at all!)
1587 if not Is_Non_Empty_List (Parameter_Specifications (Spec)) then
1588 if Aname /= Name_AST_Entry then
1590 ("subprogram renaming an attribute must have formals", N);
1595 Param_Spec := First (Parameter_Specifications (Spec));
1597 while Present (Param_Spec) loop
1598 Form_Num := Form_Num + 1;
1600 if Nkind (Parameter_Type (Param_Spec)) /= N_Access_Definition then
1601 Find_Type (Parameter_Type (Param_Spec));
1603 -- The profile of the new entity denotes the base type (s) of
1604 -- the types given in the specification. For access parameters
1605 -- there are no subtypes involved.
1607 Rewrite (Parameter_Type (Param_Spec),
1609 (Base_Type (Entity (Parameter_Type (Param_Spec))), Loc));
1612 if No (Expr_List) then
1613 Expr_List := New_List;
1616 Append_To (Expr_List,
1617 Make_Identifier (Loc,
1618 Chars => Chars (Defining_Identifier (Param_Spec))));
1624 -- Immediate error if too many formals. Other mismatches in numbers
1625 -- of number of types of parameters are detected when we analyze the
1626 -- body of the subprogram that we construct.
1628 if Form_Num > 2 then
1629 Error_Msg_N ("too many formals for attribute", N);
1632 Aname = Name_Compose or else
1633 Aname = Name_Exponent or else
1634 Aname = Name_Leading_Part or else
1635 Aname = Name_Pos or else
1636 Aname = Name_Round or else
1637 Aname = Name_Scaling or else
1640 if Nkind (N) = N_Subprogram_Renaming_Declaration
1641 and then Present (Corresponding_Spec (N))
1642 and then Nkind (Corresponding_Spec (N)) =
1643 N_Formal_Subprogram_Declaration
1646 ("generic actual cannot be attribute involving universal type",
1650 ("attribute involving a universal type cannot be renamed",
1655 -- AST_Entry is an odd case. It doesn't really make much sense to
1656 -- allow it to be renamed, but that's the DEC rule, so we have to
1657 -- do it right. The point is that the AST_Entry call should be made
1658 -- now, and what the function will return is the returned value.
1660 -- Note that there is no Expr_List in this case anyway
1662 if Aname = Name_AST_Entry then
1669 Ent := Make_Defining_Identifier (Loc, New_Internal_Name ('R'));
1672 Make_Object_Declaration (Loc,
1673 Defining_Identifier => Ent,
1674 Object_Definition =>
1675 New_Occurrence_Of (RTE (RE_AST_Handler), Loc),
1677 Constant_Present => True);
1679 Set_Assignment_OK (Decl, True);
1680 Insert_Action (N, Decl);
1681 Attr_Node := Make_Identifier (Loc, Chars (Ent));
1684 -- For all other attributes, we rewrite the attribute node to have
1685 -- a list of expressions corresponding to the subprogram formals.
1686 -- A renaming declaration is not a freeze point, and the analysis of
1687 -- the attribute reference should not freeze the type of the prefix.
1691 Make_Attribute_Reference (Loc,
1692 Prefix => Prefix (Nam),
1693 Attribute_Name => Aname,
1694 Expressions => Expr_List);
1696 Set_Must_Not_Freeze (Attr_Node);
1697 Set_Must_Not_Freeze (Prefix (Nam));
1700 -- Case of renaming a function
1702 if Nkind (Spec) = N_Function_Specification then
1704 if Is_Procedure_Attribute_Name (Aname) then
1705 Error_Msg_N ("attribute can only be renamed as procedure", Nam);
1709 Find_Type (Subtype_Mark (Spec));
1710 Rewrite (Subtype_Mark (Spec),
1711 New_Reference_To (Base_Type (Entity (Subtype_Mark (Spec))), Loc));
1714 Make_Subprogram_Body (Loc,
1715 Specification => Spec,
1716 Declarations => New_List,
1717 Handled_Statement_Sequence =>
1718 Make_Handled_Sequence_Of_Statements (Loc,
1719 Statements => New_List (
1720 Make_Return_Statement (Loc,
1721 Expression => Attr_Node))));
1723 -- Case of renaming a procedure
1726 if not Is_Procedure_Attribute_Name (Aname) then
1727 Error_Msg_N ("attribute can only be renamed as function", Nam);
1732 Make_Subprogram_Body (Loc,
1733 Specification => Spec,
1734 Declarations => New_List,
1735 Handled_Statement_Sequence =>
1736 Make_Handled_Sequence_Of_Statements (Loc,
1737 Statements => New_List (Attr_Node)));
1740 Rewrite (N, Body_Node);
1743 Set_Etype (New_S, Base_Type (Etype (New_S)));
1745 -- We suppress elaboration warnings for the resulting entity, since
1746 -- clearly they are not needed, and more particularly, in the case
1747 -- of a generic formal subprogram, the resulting entity can appear
1748 -- after the instantiation itself, and thus look like a bogus case
1749 -- of access before elaboration.
1751 Set_Suppress_Elaboration_Warnings (New_S);
1753 end Attribute_Renaming;
1755 ----------------------
1756 -- Chain_Use_Clause --
1757 ----------------------
1759 procedure Chain_Use_Clause (N : Node_Id) is
1761 Set_Next_Use_Clause (N,
1762 Scope_Stack.Table (Scope_Stack.Last).First_Use_Clause);
1763 Scope_Stack.Table (Scope_Stack.Last).First_Use_Clause := N;
1764 end Chain_Use_Clause;
1766 ----------------------------
1767 -- Check_Frozen_Renaming --
1768 ----------------------------
1770 procedure Check_Frozen_Renaming (N : Node_Id; Subp : Entity_Id) is
1776 and then not Has_Completion (Subp)
1780 (Parent (Declaration_Node (Subp)), Defining_Entity (N));
1782 if Is_Entity_Name (Name (N)) then
1783 Old_S := Entity (Name (N));
1785 if not Is_Frozen (Old_S) then
1786 Ensure_Freeze_Node (Old_S);
1787 if No (Actions (Freeze_Node (Old_S))) then
1788 Set_Actions (Freeze_Node (Old_S), New_List (B_Node));
1790 Append (B_Node, Actions (Freeze_Node (Old_S)));
1793 Insert_After (N, B_Node);
1797 if Is_Intrinsic_Subprogram (Old_S)
1798 and then not In_Instance
1801 ("subprogram used in renaming_as_body cannot be intrinsic",
1806 Insert_After (N, B_Node);
1810 end Check_Frozen_Renaming;
1812 ---------------------------------
1813 -- Check_Library_Unit_Renaming --
1814 ---------------------------------
1816 procedure Check_Library_Unit_Renaming (N : Node_Id; Old_E : Entity_Id) is
1820 if Nkind (Parent (N)) /= N_Compilation_Unit then
1823 elsif Scope (Old_E) /= Standard_Standard
1824 and then not Is_Child_Unit (Old_E)
1826 Error_Msg_N ("renamed unit must be a library unit", Name (N));
1828 elsif Present (Parent_Spec (N))
1829 and then Nkind (Unit (Parent_Spec (N))) = N_Generic_Package_Declaration
1830 and then not Is_Child_Unit (Old_E)
1833 ("renamed unit must be a child unit of generic parent", Name (N));
1835 elsif Nkind (N) in N_Generic_Renaming_Declaration
1836 and then Nkind (Name (N)) = N_Expanded_Name
1837 and then Is_Generic_Instance (Entity (Prefix (Name (N))))
1838 and then Is_Generic_Unit (Old_E)
1841 ("renamed generic unit must be a library unit", Name (N));
1843 elsif Ekind (Old_E) = E_Package
1844 or else Ekind (Old_E) = E_Generic_Package
1846 -- Inherit categorization flags
1848 New_E := Defining_Entity (N);
1849 Set_Is_Pure (New_E, Is_Pure (Old_E));
1850 Set_Is_Preelaborated (New_E, Is_Preelaborated (Old_E));
1851 Set_Is_Remote_Call_Interface (New_E,
1852 Is_Remote_Call_Interface (Old_E));
1853 Set_Is_Remote_Types (New_E, Is_Remote_Types (Old_E));
1854 Set_Is_Shared_Passive (New_E, Is_Shared_Passive (Old_E));
1856 end Check_Library_Unit_Renaming;
1862 procedure End_Scope is
1868 Id := First_Entity (Current_Scope);
1870 while Present (Id) loop
1871 -- An entity in the current scope is not necessarily the first one
1872 -- on its homonym chain. Find its predecessor if any,
1873 -- If it is an internal entity, it will not be in the visibility
1874 -- chain altogether, and there is nothing to unchain.
1876 if Id /= Current_Entity (Id) then
1877 Prev := Current_Entity (Id);
1878 while Present (Prev)
1879 and then Present (Homonym (Prev))
1880 and then Homonym (Prev) /= Id
1882 Prev := Homonym (Prev);
1885 -- Skip to end of loop if Id is not in the visibility chain
1887 if No (Prev) or else Homonym (Prev) /= Id then
1895 Outer := Homonym (Id);
1896 Set_Is_Immediately_Visible (Id, False);
1898 while Present (Outer) and then Scope (Outer) = Current_Scope loop
1899 Outer := Homonym (Outer);
1902 -- Reset homonym link of other entities, but do not modify link
1903 -- between entities in current scope, so that the back-end can have
1904 -- a proper count of local overloadings.
1907 Set_Name_Entity_Id (Chars (Id), Outer);
1909 elsif Scope (Prev) /= Scope (Id) then
1910 Set_Homonym (Prev, Outer);
1917 -- If the scope generated freeze actions, place them before the
1918 -- current declaration and analyze them. Type declarations and
1919 -- the bodies of initialization procedures can generate such nodes.
1920 -- We follow the parent chain until we reach a list node, which is
1921 -- the enclosing list of declarations. If the list appears within
1922 -- a protected definition, move freeze nodes outside the protected
1926 (Scope_Stack.Table (Scope_Stack.Last).Pending_Freeze_Actions)
1930 L : constant List_Id := Scope_Stack.Table
1931 (Scope_Stack.Last).Pending_Freeze_Actions;
1934 if Is_Itype (Current_Scope) then
1935 Decl := Associated_Node_For_Itype (Current_Scope);
1937 Decl := Parent (Current_Scope);
1942 while not (Is_List_Member (Decl))
1943 or else Nkind (Parent (Decl)) = N_Protected_Definition
1944 or else Nkind (Parent (Decl)) = N_Task_Definition
1946 Decl := Parent (Decl);
1949 Insert_List_Before_And_Analyze (Decl, L);
1958 ---------------------
1959 -- End_Use_Clauses --
1960 ---------------------
1962 procedure End_Use_Clauses (Clause : Node_Id) is
1963 U : Node_Id := Clause;
1966 while Present (U) loop
1967 if Nkind (U) = N_Use_Package_Clause then
1968 End_Use_Package (U);
1969 elsif Nkind (U) = N_Use_Type_Clause then
1973 Next_Use_Clause (U);
1975 end End_Use_Clauses;
1977 ---------------------
1978 -- End_Use_Package --
1979 ---------------------
1981 procedure End_Use_Package (N : Node_Id) is
1982 Pack_Name : Node_Id;
1988 Pack_Name := First (Names (N));
1990 while Present (Pack_Name) loop
1991 Pack := Entity (Pack_Name);
1993 if Ekind (Pack) = E_Package then
1995 if In_Open_Scopes (Pack) then
1998 elsif not Redundant_Use (Pack_Name) then
1999 Set_In_Use (Pack, False);
2000 Id := First_Entity (Pack);
2002 while Present (Id) loop
2004 -- Preserve use-visibility of operators whose formals have
2005 -- a type that is use_visible thanks to a previous use_type
2008 if Nkind (Id) = N_Defining_Operator_Symbol
2010 (In_Use (Etype (First_Formal (Id)))
2012 (Present (Next_Formal (First_Formal (Id)))
2013 and then In_Use (Etype (Next_Formal
2014 (First_Formal (Id))))))
2019 Set_Is_Potentially_Use_Visible (Id, False);
2022 if Is_Private_Type (Id)
2023 and then Present (Full_View (Id))
2025 Set_Is_Potentially_Use_Visible (Full_View (Id), False);
2031 if Present (Renamed_Object (Pack)) then
2032 Set_In_Use (Renamed_Object (Pack), False);
2035 if Chars (Pack) = Name_System
2036 and then Scope (Pack) = Standard_Standard
2037 and then Present_System_Aux
2039 Id := First_Entity (System_Aux_Id);
2041 while Present (Id) loop
2042 Set_Is_Potentially_Use_Visible (Id, False);
2044 if Is_Private_Type (Id)
2045 and then Present (Full_View (Id))
2047 Set_Is_Potentially_Use_Visible (Full_View (Id), False);
2053 Set_In_Use (System_Aux_Id, False);
2057 Set_Redundant_Use (Pack_Name, False);
2065 if Present (Hidden_By_Use_Clause (N)) then
2066 Elmt := First_Elmt (Hidden_By_Use_Clause (N));
2068 while Present (Elmt) loop
2069 Set_Is_Immediately_Visible (Node (Elmt));
2073 Set_Hidden_By_Use_Clause (N, No_Elist);
2075 end End_Use_Package;
2081 procedure End_Use_Type (N : Node_Id) is
2088 Id := First (Subtype_Marks (N));
2090 while Present (Id) loop
2093 if T = Any_Type then
2096 -- Note that the use_Type clause may mention a subtype of the
2097 -- type whose primitive operations have been made visible. Here
2098 -- as elsewhere, it is the base type that matters for visibility.
2100 elsif In_Open_Scopes (Scope (Base_Type (T))) then
2103 elsif not Redundant_Use (Id) then
2104 Set_In_Use (T, False);
2105 Set_In_Use (Base_Type (T), False);
2106 Op_List := Collect_Primitive_Operations (T);
2107 Elmt := First_Elmt (Op_List);
2109 while Present (Elmt) loop
2111 if Nkind (Node (Elmt)) = N_Defining_Operator_Symbol then
2112 Set_Is_Potentially_Use_Visible (Node (Elmt), False);
2123 ----------------------
2124 -- Find_Direct_Name --
2125 ----------------------
2127 procedure Find_Direct_Name (N : Node_Id) is
2132 Inst : Entity_Id := Empty;
2133 -- Enclosing instance, if any.
2135 Homonyms : Entity_Id;
2136 -- Saves start of homonym chain
2138 Nvis_Entity : Boolean;
2139 -- Set True to indicate that at there is at least one entity on the
2140 -- homonym chain which, while not visible, is visible enough from the
2141 -- user point of view to warrant an error message of "not visible"
2142 -- rather than undefined.
2144 function From_Actual_Package (E : Entity_Id) return Boolean;
2145 -- Returns true if the entity is declared in a package that is
2146 -- an actual for a formal package of the current instance. Such an
2147 -- entity requires special handling because it may be use-visible
2148 -- but hides directly visible entities defined outside the instance.
2150 function Known_But_Invisible (E : Entity_Id) return Boolean;
2151 -- This function determines whether the entity E (which is not
2152 -- visible) can reasonably be considered to be known to the writer
2153 -- of the reference. This is a heuristic test, used only for the
2154 -- purposes of figuring out whether we prefer to complain that an
2155 -- entity is undefined or invisible (and identify the declaration
2156 -- of the invisible entity in the latter case). The point here is
2157 -- that we don't want to complain that something is invisible and
2158 -- then point to something entirely mysterious to the writer.
2160 procedure Nvis_Messages;
2161 -- Called if there are no visible entries for N, but there is at least
2162 -- one non-directly visible, or hidden declaration. This procedure
2163 -- outputs an appropriate set of error messages.
2165 procedure Undefined (Nvis : Boolean);
2166 -- This function is called if the current node has no corresponding
2167 -- visible entity or entities. The value set in Msg indicates whether
2168 -- an error message was generated (multiple error messages for the
2169 -- same variable are generally suppressed, see body for details).
2170 -- Msg is True if an error message was generated, False if not. This
2171 -- value is used by the caller to determine whether or not to output
2172 -- additional messages where appropriate. The parameter is set False
2173 -- to get the message "X is undefined", and True to get the message
2174 -- "X is not visible".
2176 -------------------------
2177 -- From_Actual_Package --
2178 -------------------------
2180 function From_Actual_Package (E : Entity_Id) return Boolean is
2181 Scop : constant Entity_Id := Scope (E);
2185 if not In_Instance then
2188 Inst := Current_Scope;
2190 while Present (Inst)
2191 and then Ekind (Inst) /= E_Package
2192 and then not Is_Generic_Instance (Inst)
2194 Inst := Scope (Inst);
2201 Act := First_Entity (Inst);
2203 while Present (Act) loop
2204 if Ekind (Act) = E_Package then
2206 -- Check for end of actuals list
2208 if Renamed_Object (Act) = Inst then
2211 elsif Present (Associated_Formal_Package (Act))
2212 and then Renamed_Object (Act) = Scop
2214 -- Entity comes from (instance of) formal package
2229 end From_Actual_Package;
2231 -------------------------
2232 -- Known_But_Invisible --
2233 -------------------------
2235 function Known_But_Invisible (E : Entity_Id) return Boolean is
2236 Fname : File_Name_Type;
2239 -- Entities in Standard are always considered to be known
2241 if Sloc (E) <= Standard_Location then
2244 -- An entity that does not come from source is always considered
2245 -- to be unknown, since it is an artifact of code expansion.
2247 elsif not Comes_From_Source (E) then
2250 -- In gnat internal mode, we consider all entities known
2252 elsif GNAT_Mode then
2256 -- Here we have an entity that is not from package Standard, and
2257 -- which comes from Source. See if it comes from an internal file.
2259 Fname := Unit_File_Name (Get_Source_Unit (E));
2261 -- Case of from internal file
2263 if Is_Internal_File_Name (Fname) then
2265 -- Private part entities in internal files are never considered
2266 -- to be known to the writer of normal application code.
2268 if Is_Hidden (E) then
2272 -- Entities from System packages other than System and
2273 -- System.Storage_Elements are not considered to be known.
2274 -- System.Auxxxx files are also considered known to the user.
2276 -- Should refine this at some point to generally distinguish
2277 -- between known and unknown internal files ???
2279 Get_Name_String (Fname);
2284 Name_Buffer (1 .. 2) /= "s-"
2286 Name_Buffer (3 .. 8) = "stoele"
2288 Name_Buffer (3 .. 5) = "aux";
2290 -- If not an internal file, then entity is definitely known,
2291 -- even if it is in a private part (the message generated will
2292 -- note that it is in a private part)
2297 end Known_But_Invisible;
2303 procedure Nvis_Messages is
2305 Hidden : Boolean := False;
2308 Undefined (Nvis => True);
2312 -- First loop does hidden declarations
2315 while Present (Ent) loop
2316 if Is_Potentially_Use_Visible (Ent) then
2319 Error_Msg_N ("multiple use clauses cause hiding!", N);
2323 Error_Msg_Sloc := Sloc (Ent);
2324 Error_Msg_N ("hidden declaration#!", N);
2327 Ent := Homonym (Ent);
2330 -- If we found hidden declarations, then that's enough, don't
2331 -- bother looking for non-visible declarations as well.
2337 -- Second loop does non-directly visible declarations
2340 while Present (Ent) loop
2341 if not Is_Potentially_Use_Visible (Ent) then
2343 -- Do not bother the user with unknown entities
2345 if not Known_But_Invisible (Ent) then
2349 Error_Msg_Sloc := Sloc (Ent);
2351 -- Output message noting that there is a non-visible
2352 -- declaration, distinguishing the private part case.
2354 if Is_Hidden (Ent) then
2355 Error_Msg_N ("non-visible (private) declaration#!", N);
2357 Error_Msg_N ("non-visible declaration#!", N);
2362 Ent := Homonym (Ent);
2372 procedure Undefined (Nvis : Boolean) is
2373 Emsg : Error_Msg_Id;
2376 -- A very specialized error check, if the undefined variable is
2377 -- a case tag, and the case type is an enumeration type, check
2378 -- for a possible misspelling, and if so, modify the identifier
2380 -- Named aggregate should also be handled similarly ???
2382 if Nkind (N) = N_Identifier
2383 and then Nkind (Parent (N)) = N_Case_Statement_Alternative
2385 Get_Name_String (Chars (N));
2388 Case_Str : constant String := Name_Buffer (1 .. Name_Len);
2389 Case_Stm : constant Node_Id := Parent (Parent (N));
2390 Case_Typ : constant Entity_Id := Etype (Expression (Case_Stm));
2395 if Is_Enumeration_Type (Case_Typ)
2396 and then Case_Typ /= Standard_Character
2397 and then Case_Typ /= Standard_Wide_Character
2399 Lit := First_Literal (Case_Typ);
2400 Get_Name_String (Chars (Lit));
2402 if Chars (Lit) /= Chars (N)
2403 and then Is_Bad_Spelling_Of
2404 (Case_Str, Name_Buffer (1 .. Name_Len))
2406 Error_Msg_Node_2 := Lit;
2408 ("& is undefined, assume misspelling of &", N);
2409 Rewrite (N, New_Occurrence_Of (Lit, Sloc (N)));
2413 Lit := Next_Literal (Lit);
2418 -- Normal processing
2420 Set_Entity (N, Any_Id);
2421 Set_Etype (N, Any_Type);
2423 -- We use the table Urefs to keep track of entities for which we
2424 -- have issued errors for undefined references. Multiple errors
2425 -- for a single name are normally suppressed, however we modify
2426 -- the error message to alert the programmer to this effect.
2428 for J in Urefs.First .. Urefs.Last loop
2429 if Chars (N) = Chars (Urefs.Table (J).Node) then
2430 if Urefs.Table (J).Err /= No_Error_Msg
2431 and then Sloc (N) /= Urefs.Table (J).Loc
2433 Error_Msg_Node_1 := Urefs.Table (J).Node;
2435 if Urefs.Table (J).Nvis then
2436 Change_Error_Text (Urefs.Table (J).Err,
2437 "& is not visible (more references follow)");
2439 Change_Error_Text (Urefs.Table (J).Err,
2440 "& is undefined (more references follow)");
2443 Urefs.Table (J).Err := No_Error_Msg;
2446 -- Although we will set Msg False, and thus suppress the
2447 -- message, we also set Error_Posted True, to avoid any
2448 -- cascaded messages resulting from the undefined reference.
2451 Set_Error_Posted (N, True);
2456 -- If entry not found, this is first undefined occurrence
2459 Error_Msg_N ("& is not visible!", N);
2463 Error_Msg_N ("& is undefined!", N);
2466 -- A very bizarre special check, if the undefined identifier
2467 -- is put or put_line, then add a special error message (since
2468 -- this is a very common error for beginners to make).
2470 if Chars (N) = Name_Put or else Chars (N) = Name_Put_Line then
2471 Error_Msg_N ("\possible missing with of 'Text_'I'O!", N);
2474 -- Now check for possible misspellings
2476 Get_Name_String (Chars (N));
2480 Ematch : Entity_Id := Empty;
2482 Last_Name_Id : constant Name_Id :=
2483 Name_Id (Nat (First_Name_Id) +
2484 Name_Entries_Count - 1);
2486 S : constant String (1 .. Name_Len) :=
2487 Name_Buffer (1 .. Name_Len);
2490 for N in First_Name_Id .. Last_Name_Id loop
2491 E := Get_Name_Entity_Id (N);
2494 and then (Is_Immediately_Visible (E)
2496 Is_Potentially_Use_Visible (E))
2498 Get_Name_String (N);
2500 if Is_Bad_Spelling_Of
2501 (Name_Buffer (1 .. Name_Len), S)
2509 if Present (Ematch) then
2510 Error_Msg_NE ("\possible misspelling of&", N, Ematch);
2515 -- Make entry in undefined references table unless the full
2516 -- errors switch is set, in which case by refraining from
2517 -- generating the table entry, we guarantee that we get an
2518 -- error message for every undefined reference.
2520 if not All_Errors_Mode then
2521 Urefs.Increment_Last;
2522 Urefs.Table (Urefs.Last).Node := N;
2523 Urefs.Table (Urefs.Last).Err := Emsg;
2524 Urefs.Table (Urefs.Last).Nvis := Nvis;
2525 Urefs.Table (Urefs.Last).Loc := Sloc (N);
2531 -- Start of processing for Find_Direct_Name
2534 -- If the entity pointer is already set, this is an internal node, or
2535 -- a node that is analyzed more than once, after a tree modification.
2536 -- In such a case there is no resolution to perform, just set the type.
2538 if Present (Entity (N)) then
2539 if Is_Type (Entity (N)) then
2540 Set_Etype (N, Entity (N));
2544 Entyp : constant Entity_Id := Etype (Entity (N));
2547 -- One special case here. If the Etype field is already set,
2548 -- and references the packed array type corresponding to the
2549 -- etype of the referenced entity, then leave it alone. This
2550 -- happens for trees generated from Exp_Pakd, where expressions
2551 -- can be deliberately "mis-typed" to the packed array type.
2553 if Is_Array_Type (Entyp)
2554 and then Is_Packed (Entyp)
2555 and then Present (Etype (N))
2556 and then Etype (N) = Packed_Array_Type (Entyp)
2560 -- If not that special case, then just reset the Etype
2563 Set_Etype (N, Etype (Entity (N)));
2571 -- Here if Entity pointer was not set, we need full visibility analysis
2572 -- First we generate debugging output if the debug E flag is set.
2574 if Debug_Flag_E then
2575 Write_Str ("Looking for ");
2576 Write_Name (Chars (N));
2580 Homonyms := Current_Entity (N);
2581 Nvis_Entity := False;
2584 while Present (E) loop
2586 -- If entity is immediately visible or potentially use
2587 -- visible, then process the entity and we are done.
2589 if Is_Immediately_Visible (E) then
2590 goto Immediately_Visible_Entity;
2592 elsif Is_Potentially_Use_Visible (E) then
2593 goto Potentially_Use_Visible_Entity;
2595 -- Note if a known but invisible entity encountered
2597 elsif Known_But_Invisible (E) then
2598 Nvis_Entity := True;
2601 -- Move to next entity in chain and continue search
2606 -- If no entries on homonym chain that were potentially visible,
2607 -- and no entities reasonably considered as non-visible, then
2608 -- we have a plain undefined reference, with no additional
2609 -- explanation required!
2611 if not Nvis_Entity then
2612 Undefined (Nvis => False);
2615 -- Otherwise there is at least one entry on the homonym chain that
2616 -- is reasonably considered as being known and non-visible.
2623 -- Processing for a potentially use visible entry found. We must search
2624 -- the rest of the homonym chain for two reasons. First, if there is a
2625 -- directly visible entry, then none of the potentially use-visible
2626 -- entities are directly visible (RM 8.4(10)). Second, we need to check
2627 -- for the case of multiple potentially use-visible entries hiding one
2628 -- another and as a result being non-directly visible (RM 8.4(11)).
2630 <<Potentially_Use_Visible_Entity>> declare
2631 Only_One_Visible : Boolean := True;
2632 All_Overloadable : Boolean := Is_Overloadable (E);
2637 while Present (E2) loop
2638 if Is_Immediately_Visible (E2) then
2640 -- If the use-visible entity comes from the actual for a
2641 -- formal package, it hides a directly visible entity from
2642 -- outside the instance.
2644 if From_Actual_Package (E)
2645 and then Scope_Depth (E2) < Scope_Depth (Inst)
2650 goto Immediately_Visible_Entity;
2653 elsif Is_Potentially_Use_Visible (E2) then
2654 Only_One_Visible := False;
2655 All_Overloadable := All_Overloadable and Is_Overloadable (E2);
2661 -- On falling through this loop, we have checked that there are no
2662 -- immediately visible entities. Only_One_Visible is set if exactly
2663 -- one potentially use visible entity exists. All_Overloadable is
2664 -- set if all the potentially use visible entities are overloadable.
2665 -- The condition for legality is that either there is one potentially
2666 -- use visible entity, or if there is more than one, then all of them
2667 -- are overloadable.
2669 if Only_One_Visible or All_Overloadable then
2672 -- If there is more than one potentially use-visible entity and at
2673 -- least one of them non-overloadable, we have an error (RM 8.4(11).
2674 -- Note that E points to the first such entity on the homonym list.
2675 -- Special case: if one of the entities is declared in an actual
2676 -- package, it was visible in the generic, and takes precedence over
2677 -- other entities that are potentially use-visible.
2683 while Present (E2) loop
2684 if Is_Generic_Instance (Scope (E2)) then
2702 -- Come here with E set to the first immediately visible entity on
2703 -- the homonym chain. This is the one we want unless there is another
2704 -- immediately visible entity further on in the chain for a more
2705 -- inner scope (RM 8.3(8)).
2707 <<Immediately_Visible_Entity>> declare
2712 -- Find scope level of initial entity. When compiling through
2713 -- Rtsfind, the previous context is not completely invisible, and
2714 -- an outer entity may appear on the chain, whose scope is below
2715 -- the entry for Standard that delimits the current scope stack.
2716 -- Indicate that the level for this spurious entry is outside of
2717 -- the current scope stack.
2719 Level := Scope_Stack.Last;
2721 Scop := Scope_Stack.Table (Level).Entity;
2722 exit when Scop = Scope (E);
2724 exit when Scop = Standard_Standard;
2727 -- Now search remainder of homonym chain for more inner entry
2728 -- If the entity is Standard itself, it has no scope, and we
2729 -- compare it with the stack entry directly.
2732 while Present (E2) loop
2733 if Is_Immediately_Visible (E2) then
2734 for J in Level + 1 .. Scope_Stack.Last loop
2735 if Scope_Stack.Table (J).Entity = Scope (E2)
2736 or else Scope_Stack.Table (J).Entity = E2
2748 -- At the end of that loop, E is the innermost immediately
2749 -- visible entity, so we are all set.
2752 -- Come here with entity found, and stored in E
2756 if Comes_From_Source (N)
2757 and then Is_Remote_Access_To_Subprogram_Type (E)
2758 and then Expander_Active
2761 New_Occurrence_Of (Equivalent_Type (E), Sloc (N)));
2766 -- Why no Style_Check here???
2771 Set_Etype (N, Get_Full_View (Etype (E)));
2774 if Debug_Flag_E then
2775 Write_Str (" found ");
2776 Write_Entity_Info (E, " ");
2779 -- If the Ekind of the entity is Void, it means that all homonyms
2780 -- are hidden from all visibility (RM 8.3(5,14-20)). However, this
2781 -- test is skipped if the current scope is a record and the name is
2782 -- a pragma argument expression (case of Atomic and Volatile pragmas
2783 -- and possibly other similar pragmas added later, which are allowed
2784 -- to reference components in the current record).
2786 if Ekind (E) = E_Void
2788 (not Is_Record_Type (Current_Scope)
2789 or else Nkind (Parent (N)) /= N_Pragma_Argument_Association)
2791 Premature_Usage (N);
2793 -- If the entity is overloadable, collect all interpretations
2794 -- of the name for subsequent overload resolution. We optimize
2795 -- a bit here to do this only if we have an overloadable entity
2796 -- that is not on its own on the homonym chain.
2798 elsif Is_Overloadable (E)
2799 and then (Present (Homonym (E)) or else Current_Entity (N) /= E)
2801 Collect_Interps (N);
2803 -- If no homonyms were visible, the entity is unambiguous.
2805 if not Is_Overloaded (N) then
2806 Generate_Reference (E, N);
2809 -- Case of non-overloadable entity, set the entity providing that
2810 -- we do not have the case of a discriminant reference within a
2811 -- default expression. Such references are replaced with the
2812 -- corresponding discriminal, which is the formal corresponding to
2813 -- to the discriminant in the initialization procedure.
2815 -- This replacement must not be done if we are currently processing
2816 -- a generic spec or body.
2818 -- The replacement is not done either for a task discriminant that
2819 -- appears in a default expression of an entry parameter. See
2820 -- Expand_Discriminant in exp_ch2 for details on their handling.
2823 -- Entity is unambiguous, indicate that it is referenced here
2824 -- One slightly odd case is that we do not want to set the
2825 -- Referenced flag if the entity is a label, and the identifier
2826 -- is the label in the source, since this is not a reference
2827 -- from the point of view of the user
2829 if Nkind (Parent (N)) = N_Label then
2831 R : constant Boolean := Referenced (E);
2834 Generate_Reference (E, N);
2835 Set_Referenced (E, R);
2839 Generate_Reference (E, N);
2842 if not In_Default_Expression
2843 or else Ekind (E) /= E_Discriminant
2844 or else Inside_A_Generic
2846 Set_Entity_With_Style_Check (N, E);
2848 elsif Is_Concurrent_Type (Scope (E)) then
2850 P : Node_Id := Parent (N);
2854 and then Nkind (P) /= N_Parameter_Specification
2855 and then Nkind (P) /= N_Component_Declaration
2861 and then Nkind (P) = N_Parameter_Specification
2865 Set_Entity (N, Discriminal (E));
2870 Set_Entity (N, Discriminal (E));
2874 end Find_Direct_Name;
2876 ------------------------
2877 -- Find_Expanded_Name --
2878 ------------------------
2880 -- This routine searches the homonym chain of the entity until it finds
2881 -- an entity declared in the scope denoted by the prefix. If the entity
2882 -- is private, it may nevertheless be immediately visible, if we are in
2883 -- the scope of its declaration.
2885 procedure Find_Expanded_Name (N : Node_Id) is
2886 Candidate : Entity_Id := Empty;
2887 Selector : constant Node_Id := Selector_Name (N);
2893 P_Name := Entity (Prefix (N));
2896 -- If the prefix is a renamed package, look for the entity
2897 -- in the original package.
2899 if Ekind (P_Name) = E_Package
2900 and then Present (Renamed_Object (P_Name))
2902 P_Name := Renamed_Object (P_Name);
2904 -- Rewrite node with entity field pointing to renamed object
2906 Rewrite (Prefix (N), New_Copy (Prefix (N)));
2907 Set_Entity (Prefix (N), P_Name);
2909 -- If the prefix is an object of a concurrent type, look for
2910 -- the entity in the associated task or protected type.
2912 elsif Is_Concurrent_Type (Etype (P_Name)) then
2913 P_Name := Etype (P_Name);
2916 Id := Current_Entity (Selector);
2918 while Present (Id) loop
2920 if Scope (Id) = P_Name then
2923 if Is_Child_Unit (Id) then
2925 (Is_Visible_Child_Unit (Id)
2926 or else Is_Immediately_Visible (Id));
2930 (not Is_Hidden (Id) or else Is_Immediately_Visible (Id));
2938 and then (Ekind (P_Name) = E_Procedure
2940 Ekind (P_Name) = E_Function)
2941 and then Is_Generic_Instance (P_Name)
2943 -- Expanded name denotes entity in (instance of) generic subprogram.
2944 -- The entity may be in the subprogram instance, or may denote one of
2945 -- the formals, which is declared in the enclosing wrapper package.
2947 P_Name := Scope (P_Name);
2948 Id := Current_Entity (Selector);
2950 while Present (Id) loop
2951 exit when Scope (Id) = P_Name;
2956 if No (Id) or else Chars (Id) /= Chars (Selector) then
2958 Set_Etype (N, Any_Type);
2960 -- If we are looking for an entity defined in System, try to
2961 -- find it in the child package that may have been provided as
2962 -- an extension to System. The Extend_System pragma will have
2963 -- supplied the name of the extension, which may have to be loaded.
2965 if Chars (P_Name) = Name_System
2966 and then Scope (P_Name) = Standard_Standard
2967 and then Present (System_Extend_Pragma_Arg)
2968 and then Present_System_Aux (N)
2970 Set_Entity (Prefix (N), System_Aux_Id);
2971 Find_Expanded_Name (N);
2974 elsif (Nkind (Selector) = N_Operator_Symbol
2975 and then Has_Implicit_Operator (N))
2977 -- There is an implicit instance of the predefined operator in
2978 -- the given scope. The operator entity is defined in Standard.
2979 -- Has_Implicit_Operator makes the node into an Expanded_Name.
2983 elsif Nkind (Selector) = N_Character_Literal
2984 and then Has_Implicit_Character_Literal (N)
2986 -- If there is no literal defined in the scope denoted by the
2987 -- prefix, the literal may belong to (a type derived from)
2988 -- Standard_Character, for which we have no explicit literals.
2993 -- If the prefix is a single concurrent object, use its
2994 -- name in the error message, rather than that of the
2997 if Is_Concurrent_Type (P_Name)
2998 and then Is_Internal_Name (Chars (P_Name))
3000 Error_Msg_Node_2 := Entity (Prefix (N));
3002 Error_Msg_Node_2 := P_Name;
3005 if P_Name = System_Aux_Id then
3006 P_Name := Scope (P_Name);
3007 Set_Entity (Prefix (N), P_Name);
3010 if Present (Candidate) then
3012 if Is_Child_Unit (Candidate) then
3014 ("missing with_clause for child unit &", Selector);
3016 Error_Msg_NE ("& is not a visible entity of&", N, Selector);
3020 -- Within the instantiation of a child unit, the prefix may
3021 -- denote the parent instance, but the selector has the
3022 -- name of the original child. Find whether we are within
3023 -- the corresponding instance, and get the proper entity, which
3024 -- can only be an enclosing scope.
3027 and then In_Open_Scopes (P_Name)
3028 and then Is_Generic_Instance (P_Name)
3031 S : Entity_Id := Current_Scope;
3035 for J in reverse 0 .. Scope_Stack.Last loop
3036 S := Scope_Stack.Table (J).Entity;
3038 exit when S = Standard_Standard;
3040 if Ekind (S) = E_Function
3041 or else Ekind (S) = E_Package
3042 or else Ekind (S) = E_Procedure
3044 P := Generic_Parent (Specification
3045 (Unit_Declaration_Node (S)));
3048 and then Chars (Scope (P)) = Chars (O_Name)
3049 and then Chars (P) = Chars (Selector)
3060 if (Chars (P_Name) = Name_Ada
3061 and then Scope (P_Name) = Standard_Standard)
3063 Error_Msg_Node_2 := Selector;
3065 ("\missing with for `&.&`", N, P_Name);
3067 -- If this is a selection from a dummy package, then
3068 -- suppress the error message, of course the entity
3069 -- is missing if the package is missing!
3071 elsif Sloc (Error_Msg_Node_2) = No_Location then
3074 -- Here we have the case of an undefined component
3078 Error_Msg_NE ("& not declared in&", N, Selector);
3080 -- Check for misspelling of some entity in prefix.
3082 Id := First_Entity (P_Name);
3083 Get_Name_String (Chars (Selector));
3086 S : constant String (1 .. Name_Len) :=
3087 Name_Buffer (1 .. Name_Len);
3089 while Present (Id) loop
3090 Get_Name_String (Chars (Id));
3091 if Is_Bad_Spelling_Of
3092 (Name_Buffer (1 .. Name_Len), S)
3093 and then not Is_Internal_Name (Chars (Id))
3096 ("possible misspelling of&", Selector, Id);
3104 -- Specialize the message if this may be an instantiation
3105 -- of a child unit that was not mentioned in the context.
3107 if Nkind (Parent (N)) = N_Package_Instantiation
3108 and then Is_Generic_Instance (Entity (Prefix (N)))
3109 and then Is_Compilation_Unit
3110 (Generic_Parent (Parent (Entity (Prefix (N)))))
3113 ("\possible missing with clause on child unit&",
3124 if Comes_From_Source (N)
3125 and then Is_Remote_Access_To_Subprogram_Type (Id)
3127 Id := Equivalent_Type (Id);
3128 Set_Chars (Selector, Chars (Id));
3131 if Ekind (P_Name) = E_Package
3132 and then From_With_Type (P_Name)
3134 if From_With_Type (Id)
3135 or else (Ekind (Id) = E_Package and then From_With_Type (Id))
3140 ("imported package can only be used to access imported type",
3145 if Is_Task_Type (P_Name)
3146 and then ((Ekind (Id) = E_Entry
3147 and then Nkind (Parent (N)) /= N_Attribute_Reference)
3149 (Ekind (Id) = E_Entry_Family
3151 Nkind (Parent (Parent (N))) /= N_Attribute_Reference))
3153 -- It is an entry call after all, either to the current task
3154 -- (which will deadlock) or to an enclosing task.
3156 Analyze_Selected_Component (N);
3160 Change_Selected_Component_To_Expanded_Name (N);
3161 Set_Entity_With_Style_Check (N, Id);
3162 Generate_Reference (Id, N);
3164 if Is_Type (Id) then
3167 Set_Etype (N, Get_Full_View (Etype (Id)));
3170 -- If the Ekind of the entity is Void, it means that all homonyms
3171 -- are hidden from all visibility (RM 8.3(5,14-20)).
3173 if Ekind (Id) = E_Void then
3174 Premature_Usage (N);
3176 elsif Is_Overloadable (Id)
3177 and then Present (Homonym (Id))
3180 H : Entity_Id := Homonym (Id);
3183 while Present (H) loop
3184 if Scope (H) = Scope (Id) then
3185 Collect_Interps (N);
3194 if Nkind (Selector_Name (N)) = N_Operator_Symbol
3195 and then Scope (Id) /= Standard_Standard
3197 -- In addition to user-defined operators in the given scope,
3198 -- there may be an implicit instance of the predefined
3199 -- operator. The operator (defined in Standard) is found
3200 -- in Has_Implicit_Operator, and added to the interpretations.
3201 -- Procedure Add_One_Interp will determine which hides which.
3203 if Has_Implicit_Operator (N) then
3207 end Find_Expanded_Name;
3209 -------------------------
3210 -- Find_Renamed_Entity --
3211 -------------------------
3213 function Find_Renamed_Entity
3217 Is_Actual : Boolean := False) return Entity_Id
3220 I1 : Interp_Index := 0; -- Suppress junk warnings
3226 function Enclosing_Instance return Entity_Id;
3227 -- If the renaming determines the entity for the default of a formal
3228 -- subprogram nested within another instance, choose the innermost
3229 -- candidate. This is because if the formal has a box, and we are within
3230 -- an enclosing instance where some candidate interpretations are local
3231 -- to this enclosing instance, we know that the default was properly
3232 -- resolved when analyzing the generic, so we prefer the local
3233 -- candidates to those that are external. This is not always the case
3234 -- but is a reasonable heuristic on the use of nested generics.
3235 -- The proper solution requires a full renaming model.
3237 function Within (Inner, Outer : Entity_Id) return Boolean;
3238 -- Determine whether a candidate subprogram is defined within
3239 -- the enclosing instance. If yes, it has precedence over outer
3242 function Is_Visible_Operation (Op : Entity_Id) return Boolean;
3243 -- If the renamed entity is an implicit operator, check whether it is
3244 -- visible because its operand type is properly visible. This
3245 -- check applies to explicit renamed entities that appear in the
3246 -- source in a renaming declaration or a formal subprogram instance,
3247 -- but not to default generic actuals with a name.
3249 ------------------------
3250 -- Enclosing_Instance --
3251 ------------------------
3253 function Enclosing_Instance return Entity_Id is
3257 if not Is_Generic_Instance (Current_Scope)
3258 and then not Is_Actual
3263 S := Scope (Current_Scope);
3265 while S /= Standard_Standard loop
3267 if Is_Generic_Instance (S) then
3275 end Enclosing_Instance;
3277 --------------------------
3278 -- Is_Visible_Operation --
3279 --------------------------
3281 function Is_Visible_Operation (Op : Entity_Id) return Boolean is
3287 if Ekind (Op) /= E_Operator
3288 or else Scope (Op) /= Standard_Standard
3289 or else (In_Instance
3292 or else Present (Enclosing_Instance)))
3297 -- For a fixed point type operator, check the resulting type,
3298 -- because it may be a mixed mode integer * fixed operation.
3300 if Present (Next_Formal (First_Formal (New_S)))
3301 and then Is_Fixed_Point_Type (Etype (New_S))
3303 Typ := Etype (New_S);
3305 Typ := Etype (First_Formal (New_S));
3308 Btyp := Base_Type (Typ);
3310 if Nkind (Nam) /= N_Expanded_Name then
3311 return (In_Open_Scopes (Scope (Btyp))
3312 or else Is_Potentially_Use_Visible (Btyp)
3313 or else In_Use (Btyp)
3314 or else In_Use (Scope (Btyp)));
3317 Scop := Entity (Prefix (Nam));
3319 if Ekind (Scop) = E_Package
3320 and then Present (Renamed_Object (Scop))
3322 Scop := Renamed_Object (Scop);
3325 -- Operator is visible if prefix of expanded name denotes
3326 -- scope of type, or else type type is defined in System_Aux
3327 -- and the prefix denotes System.
3329 return Scope (Btyp) = Scop
3330 or else (Scope (Btyp) = System_Aux_Id
3331 and then Scope (Scope (Btyp)) = Scop);
3334 end Is_Visible_Operation;
3340 function Within (Inner, Outer : Entity_Id) return Boolean is
3341 Sc : Entity_Id := Scope (Inner);
3344 while Sc /= Standard_Standard loop
3356 -- Start of processing for Find_Renamed_Entry
3360 Candidate_Renaming := Empty;
3362 if not Is_Overloaded (Nam) then
3363 if Entity_Matches_Spec (Entity (Nam), New_S)
3364 and then Is_Visible_Operation (Entity (Nam))
3366 Old_S := Entity (Nam);
3369 Present (First_Formal (Entity (Nam)))
3370 and then Present (First_Formal (New_S))
3371 and then (Base_Type (Etype (First_Formal (Entity (Nam))))
3372 = Base_Type (Etype (First_Formal (New_S))))
3374 Candidate_Renaming := Entity (Nam);
3378 Get_First_Interp (Nam, I, It);
3380 while Present (It.Nam) loop
3382 if Entity_Matches_Spec (It.Nam, New_S)
3383 and then Is_Visible_Operation (It.Nam)
3385 if Old_S /= Any_Id then
3387 -- Note: The call to Disambiguate only happens if a
3388 -- previous interpretation was found, in which case I1
3389 -- has received a value.
3391 It1 := Disambiguate (Nam, I1, I, Etype (Old_S));
3393 if It1 = No_Interp then
3395 Inst := Enclosing_Instance;
3397 if Present (Inst) then
3399 if Within (It.Nam, Inst) then
3402 elsif Within (Old_S, Inst) then
3406 Error_Msg_N ("ambiguous renaming", N);
3411 Error_Msg_N ("ambiguous renaming", N);
3426 Present (First_Formal (It.Nam))
3427 and then Present (First_Formal (New_S))
3428 and then (Base_Type (Etype (First_Formal (It.Nam)))
3429 = Base_Type (Etype (First_Formal (New_S))))
3431 Candidate_Renaming := It.Nam;
3434 Get_Next_Interp (I, It);
3437 Set_Entity (Nam, Old_S);
3438 Set_Is_Overloaded (Nam, False);
3442 end Find_Renamed_Entity;
3444 -----------------------------
3445 -- Find_Selected_Component --
3446 -----------------------------
3448 procedure Find_Selected_Component (N : Node_Id) is
3449 P : Node_Id := Prefix (N);
3452 -- Entity denoted by prefix
3462 if Nkind (P) = N_Error then
3465 -- If the selector already has an entity, the node has been
3466 -- constructed in the course of expansion, and is known to be
3467 -- valid. Do not verify that it is defined for the type (it may
3468 -- be a private component used in the expansion of record equality).
3470 elsif Present (Entity (Selector_Name (N))) then
3473 or else Etype (N) = Any_Type
3476 Sel_Name : Node_Id := Selector_Name (N);
3477 Selector : Entity_Id := Entity (Sel_Name);
3481 Set_Etype (Sel_Name, Etype (Selector));
3483 if not Is_Entity_Name (P) then
3484 Resolve (P, Etype (P));
3487 -- Build an actual subtype except for the first parameter
3488 -- of an init_proc, where this actual subtype is by
3489 -- definition incorrect, since the object is uninitialized
3490 -- (and does not even have defined discriminants etc.)
3492 if Is_Entity_Name (P)
3493 and then Ekind (Entity (P)) = E_Function
3495 Nam := New_Copy (P);
3497 if Is_Overloaded (P) then
3498 Save_Interps (P, Nam);
3502 Make_Function_Call (Sloc (P), Name => Nam));
3504 Analyze_Selected_Component (N);
3507 elsif Ekind (Selector) = E_Component
3508 and then (not Is_Entity_Name (P)
3509 or else Chars (Entity (P)) /= Name_uInit)
3512 Build_Actual_Subtype_Of_Component (
3513 Etype (Selector), N);
3518 if No (C_Etype) then
3519 C_Etype := Etype (Selector);
3521 Insert_Action (N, C_Etype);
3522 C_Etype := Defining_Identifier (C_Etype);
3525 Set_Etype (N, C_Etype);
3528 -- If this is the name of an entry or protected operation, and
3529 -- the prefix is an access type, insert an explicit dereference,
3530 -- so that entry calls are treated uniformly.
3532 if Is_Access_Type (Etype (P))
3533 and then Is_Concurrent_Type (Designated_Type (Etype (P)))
3537 Make_Explicit_Dereference (Sloc (P),
3538 Prefix => Relocate_Node (P));
3541 Set_Etype (P, Designated_Type (Etype (Prefix (P))));
3545 -- If the selected component appears within a default expression
3546 -- and it has an actual subtype, the pre-analysis has not yet
3547 -- completed its analysis, because Insert_Actions is disabled in
3548 -- that context. Within the init_proc of the enclosing type we
3549 -- must complete this analysis, if an actual subtype was created.
3551 elsif Inside_Init_Proc then
3553 Typ : constant Entity_Id := Etype (N);
3554 Decl : constant Node_Id := Declaration_Node (Typ);
3557 if Nkind (Decl) = N_Subtype_Declaration
3558 and then not Analyzed (Decl)
3559 and then Is_List_Member (Decl)
3560 and then No (Parent (Decl))
3563 Insert_Action (N, Decl);
3570 elsif Is_Entity_Name (P) then
3571 P_Name := Entity (P);
3573 -- The prefix may denote an enclosing type which is the completion
3574 -- of an incomplete type declaration.
3576 if Is_Type (P_Name) then
3577 Set_Entity (P, Get_Full_View (P_Name));
3578 Set_Etype (P, Entity (P));
3579 P_Name := Entity (P);
3582 P_Type := Base_Type (Etype (P));
3584 if Debug_Flag_E then
3585 Write_Str ("Found prefix type to be ");
3586 Write_Entity_Info (P_Type, " "); Write_Eol;
3589 -- First check for components of a record object (not the
3590 -- result of a call, which is handled below).
3592 if Is_Appropriate_For_Record (P_Type)
3593 and then not Is_Overloadable (P_Name)
3594 and then not Is_Type (P_Name)
3596 -- Selected component of record. Type checking will validate
3597 -- name of selector.
3599 Analyze_Selected_Component (N);
3601 elsif Is_Appropriate_For_Entry_Prefix (P_Type)
3602 and then not In_Open_Scopes (P_Name)
3603 and then (not Is_Concurrent_Type (Etype (P_Name))
3604 or else not In_Open_Scopes (Etype (P_Name)))
3606 -- Call to protected operation or entry. Type checking is
3607 -- needed on the prefix.
3609 Analyze_Selected_Component (N);
3611 elsif (In_Open_Scopes (P_Name)
3612 and then Ekind (P_Name) /= E_Void
3613 and then not Is_Overloadable (P_Name))
3614 or else (Is_Concurrent_Type (Etype (P_Name))
3615 and then In_Open_Scopes (Etype (P_Name)))
3617 -- Prefix denotes an enclosing loop, block, or task, i.e. an
3618 -- enclosing construct that is not a subprogram or accept.
3620 Find_Expanded_Name (N);
3622 elsif Ekind (P_Name) = E_Package then
3623 Find_Expanded_Name (N);
3625 elsif Is_Overloadable (P_Name) then
3627 -- The subprogram may be a renaming (of an enclosing scope) as
3628 -- in the case of the name of the generic within an instantiation.
3630 if (Ekind (P_Name) = E_Procedure
3631 or else Ekind (P_Name) = E_Function)
3632 and then Present (Alias (P_Name))
3633 and then Is_Generic_Instance (Alias (P_Name))
3635 P_Name := Alias (P_Name);
3638 if Is_Overloaded (P) then
3640 -- The prefix must resolve to a unique enclosing construct.
3643 Found : Boolean := False;
3648 Get_First_Interp (P, I, It);
3650 while Present (It.Nam) loop
3652 if In_Open_Scopes (It.Nam) then
3655 "prefix must be unique enclosing scope", N);
3656 Set_Entity (N, Any_Id);
3657 Set_Etype (N, Any_Type);
3666 Get_Next_Interp (I, It);
3671 if In_Open_Scopes (P_Name) then
3672 Set_Entity (P, P_Name);
3673 Set_Is_Overloaded (P, False);
3674 Find_Expanded_Name (N);
3677 -- If no interpretation as an expanded name is possible, it
3678 -- must be a selected component of a record returned by a
3679 -- function call. Reformat prefix as a function call, the
3680 -- rest is done by type resolution. If the prefix is a
3681 -- procedure or entry, as is P.X; this is an error.
3683 if Ekind (P_Name) /= E_Function
3684 and then (not Is_Overloaded (P)
3686 Nkind (Parent (N)) = N_Procedure_Call_Statement)
3689 -- Prefix may mention a package that is hidden by a local
3690 -- declaration: let the user know. Scan the full homonym
3691 -- chain, the candidate package may be anywhere on it.
3693 if Present (Homonym (Current_Entity (P_Name))) then
3695 P_Name := Current_Entity (P_Name);
3697 while Present (P_Name) loop
3698 exit when Ekind (P_Name) = E_Package;
3699 P_Name := Homonym (P_Name);
3702 if Present (P_Name) then
3703 Error_Msg_Sloc := Sloc (Entity (Prefix (N)));
3706 ("package& is hidden by declaration#",
3709 Set_Entity (Prefix (N), P_Name);
3710 Find_Expanded_Name (N);
3713 P_Name := Entity (Prefix (N));
3718 ("invalid prefix in selected component&", N, P_Name);
3719 Change_Selected_Component_To_Expanded_Name (N);
3720 Set_Entity (N, Any_Id);
3721 Set_Etype (N, Any_Type);
3724 Nam := New_Copy (P);
3725 Save_Interps (P, Nam);
3727 Make_Function_Call (Sloc (P), Name => Nam));
3729 Analyze_Selected_Component (N);
3733 -- Remaining cases generate various error messages
3736 -- Format node as expanded name, to avoid cascaded errors
3738 Change_Node (N, N_Expanded_Name);
3740 Set_Entity (N, Any_Id);
3741 Set_Etype (N, Any_Type);
3743 -- Set_Selector_Name (N, Empty); ????
3745 -- Issue error message, but avoid this if error issued already.
3746 -- Use identifier of prefix if one is available.
3748 if P_Name = Any_Id then
3751 elsif Ekind (P_Name) = E_Void then
3752 Premature_Usage (P);
3754 elsif Nkind (P) /= N_Attribute_Reference then
3756 "invalid prefix in selected component&", P);
3760 "invalid prefix in selected component", P);
3765 -- If prefix is not the name of an entity, it must be an expression,
3766 -- whose type is appropriate for a record. This is determined by
3769 Analyze_Selected_Component (N);
3771 end Find_Selected_Component;
3777 procedure Find_Type (N : Node_Id) is
3787 elsif Nkind (N) = N_Attribute_Reference then
3789 -- Class attribute. This is only valid in Ada 95 mode, but we don't
3790 -- do a check, since the tagged type referenced could only exist if
3791 -- we were in 95 mode when it was declared (or, if we were in Ada
3792 -- 83 mode, then an error message would already have been issued).
3794 if Attribute_Name (N) = Name_Class then
3795 Check_Restriction (No_Dispatch, N);
3796 Find_Type (Prefix (N));
3798 -- Propagate error from bad prefix
3800 if Etype (Prefix (N)) = Any_Type then
3801 Set_Entity (N, Any_Type);
3802 Set_Etype (N, Any_Type);
3806 T := Base_Type (Entity (Prefix (N)));
3808 -- Case of non-tagged type
3810 if not Is_Tagged_Type (T) then
3811 if Ekind (T) = E_Incomplete_Type then
3813 -- It is legal to denote the class type of an incomplete
3814 -- type. The full type will have to be tagged, of course.
3816 Set_Is_Tagged_Type (T);
3817 Make_Class_Wide_Type (T);
3818 Set_Entity (N, Class_Wide_Type (T));
3819 Set_Etype (N, Class_Wide_Type (T));
3821 elsif Ekind (T) = E_Private_Type
3822 and then not Is_Generic_Type (T)
3823 and then In_Private_Part (Scope (T))
3825 -- The Class attribute can be applied to an untagged
3826 -- private type fulfilled by a tagged type prior to
3827 -- the full type declaration (but only within the
3828 -- parent package's private part). Create the class-wide
3829 -- type now and check that the full type is tagged
3830 -- later during its analysis. Note that we do not
3831 -- mark the private type as tagged, unlike the case
3832 -- of incomplete types, because the type must still
3833 -- appear untagged to outside units.
3835 if not Present (Class_Wide_Type (T)) then
3836 Make_Class_Wide_Type (T);
3839 Set_Entity (N, Class_Wide_Type (T));
3840 Set_Etype (N, Class_Wide_Type (T));
3843 -- Should we introduce a type Any_Tagged and use
3844 -- Wrong_Type here, it would be a bit more consistent???
3847 ("tagged type required, found}",
3848 Prefix (N), First_Subtype (T));
3849 Set_Entity (N, Any_Type);
3853 -- Case of tagged type
3856 C := Class_Wide_Type (Entity (Prefix (N)));
3857 Set_Entity_With_Style_Check (N, C);
3858 Generate_Reference (C, N);
3861 if From_With_Type (C)
3862 and then Nkind (Parent (N)) /= N_Access_Definition
3863 and then not Analyzed (T)
3866 ("imported class-wide type can only be used" &
3867 " for access parameters", N);
3871 -- Base attribute, allowed in Ada 95 mode only
3873 elsif Attribute_Name (N) = Name_Base then
3874 if Ada_83 and then Comes_From_Source (N) then
3876 ("(Ada 83) Base attribute not allowed in subtype mark", N);
3879 Find_Type (Prefix (N));
3880 Typ := Entity (Prefix (N));
3882 if Sloc (Typ) = Standard_Location
3883 and then Base_Type (Typ) = Typ
3884 and then Warn_On_Redundant_Constructs
3887 ("?redudant attribute, & is its own base type", N, Typ);
3890 T := Base_Type (Typ);
3894 -- Rewrite attribute reference with type itself (see similar
3895 -- processing in Analyze_Attribute, case Base)
3898 New_Reference_To (Entity (N), Sloc (N)));
3902 -- All other attributes are invalid in a subtype mark
3905 Error_Msg_N ("invalid attribute in subtype mark", N);
3911 if Is_Entity_Name (N) then
3912 T_Name := Entity (N);
3914 Error_Msg_N ("subtype mark required in this context", N);
3915 Set_Etype (N, Any_Type);
3919 if T_Name = Any_Id or else Etype (N) = Any_Type then
3921 -- Undefined id. Make it into a valid type
3923 Set_Entity (N, Any_Type);
3925 elsif not Is_Type (T_Name)
3926 and then T_Name /= Standard_Void_Type
3928 Error_Msg_Sloc := Sloc (T_Name);
3929 Error_Msg_N ("subtype mark required in this context", N);
3930 Error_Msg_NE ("\found & declared#", N, T_Name);
3931 Set_Entity (N, Any_Type);
3934 T_Name := Get_Full_View (T_Name);
3936 if In_Open_Scopes (T_Name) then
3937 if Ekind (Base_Type (T_Name)) = E_Task_Type then
3938 Error_Msg_N ("task type cannot be used as type mark " &
3939 "within its own body", N);
3941 Error_Msg_N ("type declaration cannot refer to itself", N);
3944 Set_Etype (N, Any_Type);
3945 Set_Entity (N, Any_Type);
3946 Set_Error_Posted (T_Name);
3950 Set_Entity (N, T_Name);
3951 Set_Etype (N, T_Name);
3955 if Present (Etype (N)) then
3956 if Is_Fixed_Point_Type (Etype (N)) then
3957 Check_Restriction (No_Fixed_Point, N);
3958 elsif Is_Floating_Point_Type (Etype (N)) then
3959 Check_Restriction (No_Floating_Point, N);
3968 function Get_Full_View (T_Name : Entity_Id) return Entity_Id is
3970 if (Ekind (T_Name) = E_Incomplete_Type
3971 and then Present (Full_View (T_Name)))
3973 return Full_View (T_Name);
3975 elsif Is_Class_Wide_Type (T_Name)
3976 and then Ekind (Root_Type (T_Name)) = E_Incomplete_Type
3977 and then Present (Full_View (Root_Type (T_Name)))
3979 return Class_Wide_Type (Full_View (Root_Type (T_Name)));
3986 ------------------------------------
3987 -- Has_Implicit_Character_Literal --
3988 ------------------------------------
3990 function Has_Implicit_Character_Literal (N : Node_Id) return Boolean is
3992 Found : Boolean := False;
3993 P : constant Entity_Id := Entity (Prefix (N));
3994 Priv_Id : Entity_Id := Empty;
3997 if Ekind (P) = E_Package
3998 and then not In_Open_Scopes (P)
4000 Priv_Id := First_Private_Entity (P);
4003 if P = Standard_Standard then
4004 Change_Selected_Component_To_Expanded_Name (N);
4005 Rewrite (N, Selector_Name (N));
4007 Set_Etype (Original_Node (N), Standard_Character);
4011 Id := First_Entity (P);
4014 and then Id /= Priv_Id
4016 if Is_Character_Type (Id)
4017 and then (Root_Type (Id) = Standard_Character
4018 or else Root_Type (Id) = Standard_Wide_Character)
4019 and then Id = Base_Type (Id)
4021 -- We replace the node with the literal itself, resolve as a
4022 -- character, and set the type correctly.
4025 Change_Selected_Component_To_Expanded_Name (N);
4026 Rewrite (N, Selector_Name (N));
4029 Set_Etype (Original_Node (N), Id);
4033 -- More than one type derived from Character in given scope.
4034 -- Collect all possible interpretations.
4036 Add_One_Interp (N, Id, Id);
4044 end Has_Implicit_Character_Literal;
4046 ---------------------------
4047 -- Has_Implicit_Operator --
4048 ---------------------------
4050 function Has_Implicit_Operator (N : Node_Id) return Boolean is
4051 Op_Id : constant Name_Id := Chars (Selector_Name (N));
4052 P : constant Entity_Id := Entity (Prefix (N));
4054 Priv_Id : Entity_Id := Empty;
4056 procedure Add_Implicit_Operator (T : Entity_Id);
4057 -- Add implicit interpretation to node N, using the type for which
4058 -- a predefined operator exists.
4060 ---------------------------
4061 -- Add_Implicit_Operator --
4062 ---------------------------
4064 procedure Add_Implicit_Operator (T : Entity_Id) is
4065 Predef_Op : Entity_Id;
4068 Predef_Op := Current_Entity (Selector_Name (N));
4070 while Present (Predef_Op)
4071 and then Scope (Predef_Op) /= Standard_Standard
4073 Predef_Op := Homonym (Predef_Op);
4076 if Nkind (N) = N_Selected_Component then
4077 Change_Selected_Component_To_Expanded_Name (N);
4080 Add_One_Interp (N, Predef_Op, T);
4082 -- For operators with unary and binary interpretations, add both
4084 if Present (Homonym (Predef_Op)) then
4085 Add_One_Interp (N, Homonym (Predef_Op), T);
4087 end Add_Implicit_Operator;
4089 -- Start of processing for Has_Implicit_Operator
4093 if Ekind (P) = E_Package
4094 and then not In_Open_Scopes (P)
4096 Priv_Id := First_Private_Entity (P);
4099 Id := First_Entity (P);
4103 -- Boolean operators: an implicit declaration exists if the scope
4104 -- contains a declaration for a derived Boolean type, or for an
4105 -- array of Boolean type.
4107 when Name_Op_And | Name_Op_Not | Name_Op_Or | Name_Op_Xor =>
4109 while Id /= Priv_Id loop
4111 if Valid_Boolean_Arg (Id)
4112 and then Id = Base_Type (Id)
4114 Add_Implicit_Operator (Id);
4121 -- Equality: look for any non-limited type. Result is Boolean.
4123 when Name_Op_Eq | Name_Op_Ne =>
4125 while Id /= Priv_Id loop
4128 and then not Is_Limited_Type (Id)
4129 and then Id = Base_Type (Id)
4131 Add_Implicit_Operator (Standard_Boolean);
4138 -- Comparison operators: scalar type, or array of scalar.
4140 when Name_Op_Lt | Name_Op_Le | Name_Op_Gt | Name_Op_Ge =>
4142 while Id /= Priv_Id loop
4143 if (Is_Scalar_Type (Id)
4144 or else (Is_Array_Type (Id)
4145 and then Is_Scalar_Type (Component_Type (Id))))
4146 and then Id = Base_Type (Id)
4148 Add_Implicit_Operator (Standard_Boolean);
4155 -- Arithmetic operators: any numeric type
4166 while Id /= Priv_Id loop
4167 if Is_Numeric_Type (Id)
4168 and then Id = Base_Type (Id)
4170 Add_Implicit_Operator (Id);
4177 -- Concatenation: any one-dimensional array type
4179 when Name_Op_Concat =>
4181 while Id /= Priv_Id loop
4182 if Is_Array_Type (Id) and then Number_Dimensions (Id) = 1
4183 and then Id = Base_Type (Id)
4185 Add_Implicit_Operator (Id);
4192 -- What is the others condition here? Should we be using a
4193 -- subtype of Name_Id that would restrict to operators ???
4195 when others => null;
4199 -- If we fall through, then we do not have an implicit operator
4203 end Has_Implicit_Operator;
4205 --------------------
4206 -- In_Open_Scopes --
4207 --------------------
4209 function In_Open_Scopes (S : Entity_Id) return Boolean is
4211 -- Since there are several scope stacks maintained by Scope_Stack each
4212 -- delineated by Standard (see comments by definition of Scope_Stack)
4213 -- it is necessary to end the search when Standard is reached.
4215 for J in reverse 0 .. Scope_Stack.Last loop
4216 if Scope_Stack.Table (J).Entity = S then
4220 -- We need Is_Active_Stack_Base to tell us when to stop rather
4221 -- than checking for Standard_Standard because there are cases
4222 -- where Standard_Standard appears in the middle of the active
4223 -- set of scopes. This affects the declaration and overriding
4224 -- of private inherited operations in instantiations of generic
4227 exit when Scope_Stack.Table (J).Is_Active_Stack_Base;
4233 -----------------------------
4234 -- Inherit_Renamed_Profile --
4235 -----------------------------
4237 procedure Inherit_Renamed_Profile (New_S : Entity_Id; Old_S : Entity_Id) is
4244 if Ekind (Old_S) = E_Operator then
4246 New_F := First_Formal (New_S);
4248 while Present (New_F) loop
4249 Set_Etype (New_F, Base_Type (Etype (New_F)));
4250 Next_Formal (New_F);
4253 Set_Etype (New_S, Base_Type (Etype (New_S)));
4256 New_F := First_Formal (New_S);
4257 Old_F := First_Formal (Old_S);
4259 while Present (New_F) loop
4260 New_T := Etype (New_F);
4261 Old_T := Etype (Old_F);
4263 -- If the new type is a renaming of the old one, as is the
4264 -- case for actuals in instances, retain its name, to simplify
4265 -- later disambiguation.
4267 if Nkind (Parent (New_T)) = N_Subtype_Declaration
4268 and then Is_Entity_Name (Subtype_Indication (Parent (New_T)))
4269 and then Entity (Subtype_Indication (Parent (New_T))) = Old_T
4273 Set_Etype (New_F, Old_T);
4276 Next_Formal (New_F);
4277 Next_Formal (Old_F);
4280 if Ekind (Old_S) = E_Function
4281 or else Ekind (Old_S) = E_Enumeration_Literal
4283 Set_Etype (New_S, Etype (Old_S));
4286 end Inherit_Renamed_Profile;
4292 procedure Initialize is
4297 -------------------------
4298 -- Install_Use_Clauses --
4299 -------------------------
4301 procedure Install_Use_Clauses (Clause : Node_Id) is
4302 U : Node_Id := Clause;
4307 while Present (U) loop
4309 -- Case of USE package
4311 if Nkind (U) = N_Use_Package_Clause then
4312 P := First (Names (U));
4314 while Present (P) loop
4317 if Ekind (Id) = E_Package then
4320 Set_Redundant_Use (P, True);
4322 elsif Present (Renamed_Object (Id))
4323 and then In_Use (Renamed_Object (Id))
4325 Set_Redundant_Use (P, True);
4328 Use_One_Package (Id, U);
4338 P := First (Subtype_Marks (U));
4340 while Present (P) loop
4342 if Entity (P) /= Any_Type then
4343 Use_One_Type (P, U);
4350 Next_Use_Clause (U);
4352 end Install_Use_Clauses;
4354 -------------------------------------
4355 -- Is_Appropriate_For_Entry_Prefix --
4356 -------------------------------------
4358 function Is_Appropriate_For_Entry_Prefix (T : Entity_Id) return Boolean is
4359 P_Type : Entity_Id := T;
4362 if Is_Access_Type (P_Type) then
4363 P_Type := Designated_Type (P_Type);
4366 return Is_Task_Type (P_Type) or else Is_Protected_Type (P_Type);
4367 end Is_Appropriate_For_Entry_Prefix;
4369 -------------------------------
4370 -- Is_Appropriate_For_Record --
4371 -------------------------------
4373 function Is_Appropriate_For_Record
4377 function Has_Components (T1 : Entity_Id) return Boolean;
4378 -- Determine if given type has components (i.e. is either a record
4379 -- type or a type that has discriminants).
4381 function Has_Components (T1 : Entity_Id) return Boolean is
4383 return Is_Record_Type (T1)
4384 or else (Is_Private_Type (T1) and then Has_Discriminants (T1))
4385 or else (Is_Task_Type (T1) and then Has_Discriminants (T1));
4388 -- Start of processing for Is_Appropriate_For_Record
4393 and then (Has_Components (T)
4394 or else (Is_Access_Type (T)
4396 Has_Components (Designated_Type (T))));
4397 end Is_Appropriate_For_Record;
4403 procedure New_Scope (S : Entity_Id) is
4407 if Ekind (S) = E_Void then
4410 -- Set scope depth if not a non-concurrent type, and we have not
4411 -- yet set the scope depth. This means that we have the first
4412 -- occurrence of the scope, and this is where the depth is set.
4414 elsif (not Is_Type (S) or else Is_Concurrent_Type (S))
4415 and then not Scope_Depth_Set (S)
4417 if S = Standard_Standard then
4418 Set_Scope_Depth_Value (S, Uint_0);
4420 elsif Is_Child_Unit (S) then
4421 Set_Scope_Depth_Value (S, Uint_1);
4423 elsif not Is_Record_Type (Current_Scope) then
4424 if Ekind (S) = E_Loop then
4425 Set_Scope_Depth_Value (S, Scope_Depth (Current_Scope));
4427 Set_Scope_Depth_Value (S, Scope_Depth (Current_Scope) + 1);
4432 Scope_Stack.Increment_Last;
4434 Scope_Stack.Table (Scope_Stack.Last).Entity := S;
4436 Scope_Stack.Table (Scope_Stack.Last).Save_Scope_Suppress :=
4439 Scope_Stack.Table (Scope_Stack.Last).Save_Entity_Suppress :=
4440 Entity_Suppress.Last;
4442 if Scope_Stack.Last > Scope_Stack.First then
4443 Scope_Stack.Table (Scope_Stack.Last).Component_Alignment_Default :=
4444 Scope_Stack.Table (Scope_Stack.Last - 1).Component_Alignment_Default;
4447 Scope_Stack.Table (Scope_Stack.Last).Last_Subprogram_Name := null;
4448 Scope_Stack.Table (Scope_Stack.Last).Is_Transient := False;
4449 Scope_Stack.Table (Scope_Stack.Last).Node_To_Be_Wrapped := Empty;
4450 Scope_Stack.Table (Scope_Stack.Last).Pending_Freeze_Actions := No_List;
4452 (Scope_Stack.Last).Actions_To_Be_Wrapped_Before := No_List;
4454 (Scope_Stack.Last).Actions_To_Be_Wrapped_After := No_List;
4455 Scope_Stack.Table (Scope_Stack.Last).First_Use_Clause := Empty;
4456 Scope_Stack.Table (Scope_Stack.Last).Is_Active_Stack_Base := False;
4458 if Debug_Flag_W then
4459 Write_Str ("--> new scope: ");
4460 Write_Name (Chars (Current_Scope));
4461 Write_Str (", Id=");
4462 Write_Int (Int (Current_Scope));
4463 Write_Str (", Depth=");
4464 Write_Int (Int (Scope_Stack.Last));
4468 -- Copy from Scope (S) the categorization flags to S, this is not
4469 -- done in case Scope (S) is Standard_Standard since propagation
4470 -- is from library unit entity inwards.
4472 if S /= Standard_Standard
4473 and then Scope (S) /= Standard_Standard
4474 and then not Is_Child_Unit (S)
4478 if Nkind (E) not in N_Entity then
4482 -- We only propagate inwards for library level entities,
4483 -- inner level subprograms do not inherit the categorization.
4485 if Is_Library_Level_Entity (S) then
4486 Set_Is_Pure (S, Is_Pure (E));
4487 Set_Is_Preelaborated (S, Is_Preelaborated (E));
4488 Set_Is_Remote_Call_Interface (S, Is_Remote_Call_Interface (E));
4489 Set_Is_Remote_Types (S, Is_Remote_Types (E));
4490 Set_Is_Shared_Passive (S, Is_Shared_Passive (E));
4499 procedure Pop_Scope is
4503 if Debug_Flag_E then
4508 Scope_Stack.Table (Scope_Stack.Last).Save_Scope_Suppress;
4510 while Entity_Suppress.Last >
4511 Scope_Stack.Table (Scope_Stack.Last).Save_Entity_Suppress
4513 E := Entity_Suppress.Table (Entity_Suppress.Last).Entity;
4515 case Entity_Suppress.Table (Entity_Suppress.Last).Check is
4517 when Access_Check =>
4518 Set_Suppress_Access_Checks (E, False);
4520 when Accessibility_Check =>
4521 Set_Suppress_Accessibility_Checks (E, False);
4523 when Discriminant_Check =>
4524 Set_Suppress_Discriminant_Checks (E, False);
4526 when Division_Check =>
4527 Set_Suppress_Division_Checks (E, False);
4529 when Elaboration_Check =>
4530 Set_Suppress_Elaboration_Checks (E, False);
4533 Set_Suppress_Index_Checks (E, False);
4535 when Length_Check =>
4536 Set_Suppress_Length_Checks (E, False);
4538 when Overflow_Check =>
4539 Set_Suppress_Overflow_Checks (E, False);
4542 Set_Suppress_Range_Checks (E, False);
4544 when Storage_Check =>
4545 Set_Suppress_Storage_Checks (E, False);
4548 Set_Suppress_Tag_Checks (E, False);
4550 -- All_Checks should not appear here (since it is entered as a
4551 -- series of its separate checks). Bomb if it is encountered
4554 raise Program_Error;
4557 Entity_Suppress.Decrement_Last;
4560 if Debug_Flag_W then
4561 Write_Str ("--> exiting scope: ");
4562 Write_Name (Chars (Current_Scope));
4563 Write_Str (", Depth=");
4564 Write_Int (Int (Scope_Stack.Last));
4568 End_Use_Clauses (Scope_Stack.Table (Scope_Stack.Last).First_Use_Clause);
4570 -- If the actions to be wrapped are still there they will get lost
4571 -- causing incomplete code to be generated. It is better to abort in
4574 pragma Assert (Scope_Stack.Table
4575 (Scope_Stack.Last).Actions_To_Be_Wrapped_Before = No_List);
4577 pragma Assert (Scope_Stack.Table
4578 (Scope_Stack.Last).Actions_To_Be_Wrapped_After = No_List);
4580 -- Free last subprogram name if allocated, and pop scope
4582 Free (Scope_Stack.Table (Scope_Stack.Last).Last_Subprogram_Name);
4583 Scope_Stack.Decrement_Last;
4586 ---------------------
4587 -- Premature_Usage --
4588 ---------------------
4590 procedure Premature_Usage (N : Node_Id) is
4591 Kind : Node_Kind := Nkind (Parent (Entity (N)));
4592 E : Entity_Id := Entity (N);
4595 -- Within an instance, the analysis of the actual for a formal object
4596 -- does not see the name of the object itself. This is significant
4597 -- only if the object is an aggregate, where its analysis does not do
4598 -- any name resolution on component associations. (see 4717-008). In
4599 -- such a case, look for the visible homonym on the chain.
4602 and then Present (Homonym (E))
4607 and then not In_Open_Scopes (Scope (E))
4614 Set_Etype (N, Etype (E));
4619 if Kind = N_Component_Declaration then
4621 ("component&! cannot be used before end of record declaration", N);
4623 elsif Kind = N_Parameter_Specification then
4625 ("formal parameter&! cannot be used before end of specification",
4628 elsif Kind = N_Discriminant_Specification then
4630 ("discriminant&! cannot be used before end of discriminant part",
4633 elsif Kind = N_Procedure_Specification
4634 or else Kind = N_Function_Specification
4637 ("subprogram&! cannot be used before end of its declaration",
4641 ("object& cannot be used before end of its declaration!", N);
4643 end Premature_Usage;
4645 ------------------------
4646 -- Present_System_Aux --
4647 ------------------------
4649 function Present_System_Aux (N : Node_Id := Empty) return Boolean is
4652 Unum : Unit_Number_Type;
4657 function Find_System (C_Unit : Node_Id) return Entity_Id;
4658 -- Scan context clause of compilation unit to find a with_clause
4661 function Find_System (C_Unit : Node_Id) return Entity_Id is
4662 With_Clause : Node_Id;
4665 With_Clause := First (Context_Items (C_Unit));
4667 while Present (With_Clause) loop
4668 if (Nkind (With_Clause) = N_With_Clause
4669 and then Chars (Name (With_Clause)) = Name_System)
4670 and then Comes_From_Source (With_Clause)
4681 -- Start of processing for Present_System_Aux
4684 -- The child unit may have been loaded and analyzed already.
4686 if Present (System_Aux_Id) then
4689 -- If no previous pragma for System.Aux, nothing to load
4691 elsif No (System_Extend_Pragma_Arg) then
4694 -- Use the unit name given in the pragma to retrieve the unit.
4695 -- Verify that System itself appears in the context clause of the
4696 -- current compilation. If System is not present, an error will
4697 -- have been reported already.
4700 With_Sys := Find_System (Cunit (Current_Sem_Unit));
4702 The_Unit := Unit (Cunit (Current_Sem_Unit));
4705 and then (Nkind (The_Unit) = N_Package_Body
4706 or else (Nkind (The_Unit) = N_Subprogram_Body
4707 and then not Acts_As_Spec (Cunit (Current_Sem_Unit))))
4709 With_Sys := Find_System (Library_Unit (Cunit (Current_Sem_Unit)));
4713 and then Present (N)
4715 -- If we are compiling a subunit, we need to examine its
4716 -- context as well (Current_Sem_Unit is the parent unit);
4718 The_Unit := Parent (N);
4720 while Nkind (The_Unit) /= N_Compilation_Unit loop
4721 The_Unit := Parent (The_Unit);
4724 if Nkind (Unit (The_Unit)) = N_Subunit then
4725 With_Sys := Find_System (The_Unit);
4729 if No (With_Sys) then
4733 Loc := Sloc (With_Sys);
4734 Get_Name_String (Chars (Expression (System_Extend_Pragma_Arg)));
4735 Name_Buffer (8 .. Name_Len + 7) := Name_Buffer (1 .. Name_Len);
4736 Name_Buffer (1 .. 7) := "system.";
4737 Name_Buffer (Name_Len + 8) := '%';
4738 Name_Buffer (Name_Len + 9) := 's';
4739 Name_Len := Name_Len + 9;
4740 Aux_Name := Name_Find;
4744 (Load_Name => Aux_Name,
4747 Error_Node => With_Sys);
4749 if Unum /= No_Unit then
4750 Semantics (Cunit (Unum));
4752 Defining_Entity (Specification (Unit (Cunit (Unum))));
4754 Withn := Make_With_Clause (Loc,
4756 Make_Expanded_Name (Loc,
4757 Chars => Chars (System_Aux_Id),
4759 New_Reference_To (Scope (System_Aux_Id), Loc),
4761 New_Reference_To (System_Aux_Id, Loc)));
4763 Set_Entity (Name (Withn), System_Aux_Id);
4765 Set_Library_Unit (Withn, Cunit (Unum));
4766 Set_Corresponding_Spec (Withn, System_Aux_Id);
4767 Set_First_Name (Withn, True);
4768 Set_Implicit_With (Withn, True);
4770 Insert_After (With_Sys, Withn);
4771 Mark_Rewrite_Insertion (Withn);
4772 Set_Context_Installed (Withn);
4776 -- Here if unit load failed
4779 Error_Msg_Name_1 := Name_System;
4780 Error_Msg_Name_2 := Chars (Expression (System_Extend_Pragma_Arg));
4782 ("extension package `%.%` does not exist",
4783 Opt.System_Extend_Pragma_Arg);
4787 end Present_System_Aux;
4789 -------------------------
4790 -- Restore_Scope_Stack --
4791 -------------------------
4793 procedure Restore_Scope_Stack is
4796 Comp_Unit : Node_Id;
4797 In_Child : Boolean := False;
4798 Full_Vis : Boolean := True;
4801 -- Restore visibility of previous scope stack, if any.
4803 for J in reverse 0 .. Scope_Stack.Last loop
4804 exit when Scope_Stack.Table (J).Entity = Standard_Standard
4805 or else No (Scope_Stack.Table (J).Entity);
4807 S := Scope_Stack.Table (J).Entity;
4809 if not Is_Hidden_Open_Scope (S) then
4811 -- If the parent scope is hidden, its entities are hidden as
4812 -- well, unless the entity is the instantiation currently
4815 if not Is_Hidden_Open_Scope (Scope (S))
4816 or else not Analyzed (Parent (S))
4817 or else Scope (S) = Standard_Standard
4819 Set_Is_Immediately_Visible (S, True);
4822 E := First_Entity (S);
4824 while Present (E) loop
4825 if Is_Child_Unit (E) then
4826 Set_Is_Immediately_Visible (E,
4827 Is_Visible_Child_Unit (E) or else In_Open_Scopes (E));
4829 Set_Is_Immediately_Visible (E, True);
4834 if not Full_Vis then
4835 exit when E = First_Private_Entity (S);
4839 -- The visibility of child units (siblings of current compilation)
4840 -- must be restored in any case. Their declarations may appear
4841 -- after the private part of the parent.
4844 and then Present (E)
4846 while Present (E) loop
4847 if Is_Child_Unit (E) then
4848 Set_Is_Immediately_Visible (E,
4849 Is_Visible_Child_Unit (E) or else In_Open_Scopes (E));
4857 if Is_Child_Unit (S)
4858 and not In_Child -- check only for current unit.
4862 -- restore visibility of parents according to whether the child
4863 -- is private and whether we are in its visible part.
4865 Comp_Unit := Parent (Unit_Declaration_Node (S));
4867 if Nkind (Comp_Unit) = N_Compilation_Unit
4868 and then Private_Present (Comp_Unit)
4872 elsif (Ekind (S) = E_Package
4873 or else Ekind (S) = E_Generic_Package)
4874 and then (In_Private_Part (S)
4875 or else In_Package_Body (S))
4879 elsif (Ekind (S) = E_Procedure
4880 or else Ekind (S) = E_Function)
4881 and then Has_Completion (S)
4891 end Restore_Scope_Stack;
4893 ----------------------
4894 -- Save_Scope_Stack --
4895 ----------------------
4897 procedure Save_Scope_Stack is
4900 SS_Last : constant Int := Scope_Stack.Last;
4903 if SS_Last >= Scope_Stack.First
4904 and then Scope_Stack.Table (SS_Last).Entity /= Standard_Standard
4907 -- If the call is from within a compilation unit, as when
4908 -- called from Rtsfind, make current entries in scope stack
4909 -- invisible while we analyze the new unit.
4911 for J in reverse 0 .. SS_Last loop
4912 exit when Scope_Stack.Table (J).Entity = Standard_Standard
4913 or else No (Scope_Stack.Table (J).Entity);
4915 S := Scope_Stack.Table (J).Entity;
4916 Set_Is_Immediately_Visible (S, False);
4917 E := First_Entity (S);
4919 while Present (E) loop
4920 Set_Is_Immediately_Visible (E, False);
4926 end Save_Scope_Stack;
4932 procedure Set_Use (L : List_Id) is
4934 Pack_Name : Node_Id;
4942 while Present (Decl) loop
4943 if Nkind (Decl) = N_Use_Package_Clause then
4944 Chain_Use_Clause (Decl);
4945 Pack_Name := First (Names (Decl));
4947 while Present (Pack_Name) loop
4948 Pack := Entity (Pack_Name);
4950 if Ekind (Pack) = E_Package
4951 and then Applicable_Use (Pack_Name)
4953 Use_One_Package (Pack, Decl);
4959 elsif Nkind (Decl) = N_Use_Type_Clause then
4960 Chain_Use_Clause (Decl);
4961 Id := First (Subtype_Marks (Decl));
4963 while Present (Id) loop
4964 if Entity (Id) /= Any_Type then
4965 Use_One_Type (Id, Decl);
4977 ---------------------
4978 -- Use_One_Package --
4979 ---------------------
4981 procedure Use_One_Package (P : Entity_Id; N : Node_Id) is
4984 Current_Instance : Entity_Id := Empty;
4988 if Ekind (P) /= E_Package then
4994 if From_With_Type (P) then
4995 Error_Msg_N ("imported package cannot appear in use clause", N);
4998 -- Find enclosing instance, if any.
5001 Current_Instance := Current_Scope;
5003 while not Is_Generic_Instance (Current_Instance) loop
5004 Current_Instance := Scope (Current_Instance);
5007 if No (Hidden_By_Use_Clause (N)) then
5008 Set_Hidden_By_Use_Clause (N, New_Elmt_List);
5012 -- If unit is a package renaming, indicate that the renamed
5013 -- package is also in use (the flags on both entities must
5014 -- remain consistent, and a subsequent use of either of them
5015 -- should be recognized as redundant).
5017 if Present (Renamed_Object (P)) then
5018 Set_In_Use (Renamed_Object (P));
5019 Real_P := Renamed_Object (P);
5024 -- Loop through entities in one package making them potentially
5027 Id := First_Entity (P);
5029 and then Id /= First_Private_Entity (P)
5031 Prev := Current_Entity (Id);
5033 while Present (Prev) loop
5034 if Is_Immediately_Visible (Prev)
5035 and then (not Is_Overloadable (Prev)
5036 or else not Is_Overloadable (Id)
5037 or else (Type_Conformant (Id, Prev)))
5039 if No (Current_Instance) then
5041 -- Potentially use-visible entity remains hidden
5043 goto Next_Usable_Entity;
5045 -- A use clause within an instance hides outer global
5046 -- entities, which are not used to resolve local entities
5047 -- in the instance. Note that the predefined entities in
5048 -- Standard could not have been hidden in the generic by
5049 -- a use clause, and therefore remain visible. Other
5050 -- compilation units whose entities appear in Standard must
5051 -- be hidden in an instance.
5053 -- To determine whether an entity is external to the instance
5054 -- we compare the scope depth of its scope with that of the
5055 -- current instance. However, a generic actual of a subprogram
5056 -- instance is declared in the wrapper package but will not be
5057 -- hidden by a use-visible entity.
5059 elsif not Is_Hidden (Id)
5060 and then not Is_Wrapper_Package (Scope (Prev))
5061 and then Scope_Depth (Scope (Prev)) <
5062 Scope_Depth (Current_Instance)
5063 and then (Scope (Prev) /= Standard_Standard
5064 or else Sloc (Prev) > Standard_Location)
5066 Set_Is_Potentially_Use_Visible (Id);
5067 Set_Is_Immediately_Visible (Prev, False);
5068 Append_Elmt (Prev, Hidden_By_Use_Clause (N));
5071 -- A user-defined operator is not use-visible if the
5072 -- predefined operator for the type is immediately visible,
5073 -- which is the case if the type of the operand is in an open
5074 -- scope. This does not apply to user-defined operators that
5075 -- have operands of different types, because the predefined
5076 -- mixed mode operations (multiplication and division) apply to
5077 -- universal types and do not hide anything.
5079 elsif Ekind (Prev) = E_Operator
5080 and then Operator_Matches_Spec (Prev, Id)
5081 and then In_Open_Scopes
5082 (Scope (Base_Type (Etype (First_Formal (Id)))))
5083 and then (No (Next_Formal (First_Formal (Id)))
5084 or else Etype (First_Formal (Id))
5085 = Etype (Next_Formal (First_Formal (Id)))
5086 or else Chars (Prev) = Name_Op_Expon)
5088 goto Next_Usable_Entity;
5091 Prev := Homonym (Prev);
5094 -- On exit, we know entity is not hidden, unless it is private.
5096 if not Is_Hidden (Id)
5097 and then ((not Is_Child_Unit (Id))
5098 or else Is_Visible_Child_Unit (Id))
5100 Set_Is_Potentially_Use_Visible (Id);
5102 if Is_Private_Type (Id)
5103 and then Present (Full_View (Id))
5105 Set_Is_Potentially_Use_Visible (Full_View (Id));
5109 <<Next_Usable_Entity>>
5113 -- Child units are also made use-visible by a use clause, but they
5114 -- may appear after all visible declarations in the parent entity list.
5116 while Present (Id) loop
5118 if Is_Child_Unit (Id)
5119 and then Is_Visible_Child_Unit (Id)
5121 Set_Is_Potentially_Use_Visible (Id);
5127 if Chars (Real_P) = Name_System
5128 and then Scope (Real_P) = Standard_Standard
5129 and then Present_System_Aux (N)
5131 Use_One_Package (System_Aux_Id, N);
5134 end Use_One_Package;
5140 procedure Use_One_Type (Id : Node_Id; N : Node_Id) is
5146 -- It is the type determined by the subtype mark (8.4(8)) whose
5147 -- operations become potentially use-visible.
5149 T := Base_Type (Entity (Id));
5151 -- Save current visibility status of type, before setting.
5154 (Id, In_Use (T) or else Is_Potentially_Use_Visible (T));
5156 if In_Open_Scopes (Scope (T)) then
5159 elsif not Redundant_Use (Id) then
5161 Op_List := Collect_Primitive_Operations (T);
5162 Elmt := First_Elmt (Op_List);
5164 while Present (Elmt) loop
5166 if (Nkind (Node (Elmt)) = N_Defining_Operator_Symbol
5167 or else Chars (Node (Elmt)) in Any_Operator_Name)
5168 and then not Is_Hidden (Node (Elmt))
5170 Set_Is_Potentially_Use_Visible (Node (Elmt));
5183 procedure Write_Info is
5184 Id : Entity_Id := First_Entity (Current_Scope);
5187 -- No point in dumping standard entities
5189 if Current_Scope = Standard_Standard then
5193 Write_Str ("========================================================");
5195 Write_Str (" Defined Entities in ");
5196 Write_Name (Chars (Current_Scope));
5198 Write_Str ("========================================================");
5202 Write_Str ("-- none --");
5206 while Present (Id) loop
5207 Write_Entity_Info (Id, " ");
5212 if Scope (Current_Scope) = Standard_Standard then
5214 -- Print information on the current unit itself
5216 Write_Entity_Info (Current_Scope, " ");
5226 procedure Write_Scopes is
5230 for J in reverse 1 .. Scope_Stack.Last loop
5231 S := Scope_Stack.Table (J).Entity;
5232 Write_Int (Int (S));
5233 Write_Str (" === ");
5234 Write_Name (Chars (S));