1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2010, Free Software Foundation, Inc. --
11 -- GNAT is free software; you can redistribute it and/or modify it under --
12 -- terms of the GNU General Public License as published by the Free Soft- --
13 -- ware Foundation; either version 3, or (at your option) any later ver- --
14 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
15 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
16 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
17 -- for more details. You should have received a copy of the GNU General --
18 -- Public License distributed with GNAT; see file COPYING3. If not, go to --
19 -- http://www.gnu.org/licenses for a complete copy of the license. --
21 -- GNAT was originally developed by the GNAT team at New York University. --
22 -- Extensive contributions were provided by Ada Core Technologies Inc. --
24 ------------------------------------------------------------------------------
26 with Atree; use Atree;
27 with Debug; use Debug;
28 with Einfo; use Einfo;
29 with Elists; use Elists;
30 with Errout; use Errout;
31 with Exp_Tss; use Exp_Tss;
32 with Exp_Util; use Exp_Util;
33 with Fname; use Fname;
34 with Freeze; use Freeze;
35 with Impunit; use Impunit;
37 with Lib.Load; use Lib.Load;
38 with Lib.Xref; use Lib.Xref;
39 with Namet; use Namet;
40 with Namet.Sp; use Namet.Sp;
41 with Nlists; use Nlists;
42 with Nmake; use Nmake;
44 with Output; use Output;
45 with Restrict; use Restrict;
46 with Rident; use Rident;
47 with Rtsfind; use Rtsfind;
49 with Sem_Aux; use Sem_Aux;
50 with Sem_Cat; use Sem_Cat;
51 with Sem_Ch3; use Sem_Ch3;
52 with Sem_Ch4; use Sem_Ch4;
53 with Sem_Ch6; use Sem_Ch6;
54 with Sem_Ch12; use Sem_Ch12;
55 with Sem_Disp; use Sem_Disp;
56 with Sem_Dist; use Sem_Dist;
57 with Sem_Eval; use Sem_Eval;
58 with Sem_Res; use Sem_Res;
59 with Sem_Util; use Sem_Util;
60 with Sem_Type; use Sem_Type;
61 with Stand; use Stand;
62 with Sinfo; use Sinfo;
63 with Sinfo.CN; use Sinfo.CN;
64 with Snames; use Snames;
65 with Style; use Style;
67 with Targparm; use Targparm;
68 with Tbuild; use Tbuild;
69 with Uintp; use Uintp;
71 package body Sem_Ch8 is
73 ------------------------------------
74 -- Visibility and Name Resolution --
75 ------------------------------------
77 -- This package handles name resolution and the collection of
78 -- interpretations for overloaded names, prior to overload resolution.
80 -- Name resolution is the process that establishes a mapping between source
81 -- identifiers and the entities they denote at each point in the program.
82 -- Each entity is represented by a defining occurrence. Each identifier
83 -- that denotes an entity points to the corresponding defining occurrence.
84 -- This is the entity of the applied occurrence. Each occurrence holds
85 -- an index into the names table, where source identifiers are stored.
87 -- Each entry in the names table for an identifier or designator uses the
88 -- Info pointer to hold a link to the currently visible entity that has
89 -- this name (see subprograms Get_Name_Entity_Id and Set_Name_Entity_Id
90 -- in package Sem_Util). The visibility is initialized at the beginning of
91 -- semantic processing to make entities in package Standard immediately
92 -- visible. The visibility table is used in a more subtle way when
93 -- compiling subunits (see below).
95 -- Entities that have the same name (i.e. homonyms) are chained. In the
96 -- case of overloaded entities, this chain holds all the possible meanings
97 -- of a given identifier. The process of overload resolution uses type
98 -- information to select from this chain the unique meaning of a given
101 -- Entities are also chained in their scope, through the Next_Entity link.
102 -- As a consequence, the name space is organized as a sparse matrix, where
103 -- each row corresponds to a scope, and each column to a source identifier.
104 -- Open scopes, that is to say scopes currently being compiled, have their
105 -- corresponding rows of entities in order, innermost scope first.
107 -- The scopes of packages that are mentioned in context clauses appear in
108 -- no particular order, interspersed among open scopes. This is because
109 -- in the course of analyzing the context of a compilation, a package
110 -- declaration is first an open scope, and subsequently an element of the
111 -- context. If subunits or child units are present, a parent unit may
112 -- appear under various guises at various times in the compilation.
114 -- When the compilation of the innermost scope is complete, the entities
115 -- defined therein are no longer visible. If the scope is not a package
116 -- declaration, these entities are never visible subsequently, and can be
117 -- removed from visibility chains. If the scope is a package declaration,
118 -- its visible declarations may still be accessible. Therefore the entities
119 -- defined in such a scope are left on the visibility chains, and only
120 -- their visibility (immediately visibility or potential use-visibility)
123 -- The ordering of homonyms on their chain does not necessarily follow
124 -- the order of their corresponding scopes on the scope stack. For
125 -- example, if package P and the enclosing scope both contain entities
126 -- named E, then when compiling the package body the chain for E will
127 -- hold the global entity first, and the local one (corresponding to
128 -- the current inner scope) next. As a result, name resolution routines
129 -- do not assume any relative ordering of the homonym chains, either
130 -- for scope nesting or to order of appearance of context clauses.
132 -- When compiling a child unit, entities in the parent scope are always
133 -- immediately visible. When compiling the body of a child unit, private
134 -- entities in the parent must also be made immediately visible. There
135 -- are separate routines to make the visible and private declarations
136 -- visible at various times (see package Sem_Ch7).
138 -- +--------+ +-----+
139 -- | In use |-------->| EU1 |-------------------------->
140 -- +--------+ +-----+
142 -- +--------+ +-----+ +-----+
143 -- | Stand. |---------------->| ES1 |--------------->| ES2 |--->
144 -- +--------+ +-----+ +-----+
146 -- +---------+ | +-----+
147 -- | with'ed |------------------------------>| EW2 |--->
148 -- +---------+ | +-----+
150 -- +--------+ +-----+ +-----+
151 -- | Scope2 |---------------->| E12 |--------------->| E22 |--->
152 -- +--------+ +-----+ +-----+
154 -- +--------+ +-----+ +-----+
155 -- | Scope1 |---------------->| E11 |--------------->| E12 |--->
156 -- +--------+ +-----+ +-----+
160 -- | | with'ed |----------------------------------------->
164 -- (innermost first) | |
165 -- +----------------------------+
166 -- Names table => | Id1 | | | | Id2 |
167 -- +----------------------------+
169 -- Name resolution must deal with several syntactic forms: simple names,
170 -- qualified names, indexed names, and various forms of calls.
172 -- Each identifier points to an entry in the names table. The resolution
173 -- of a simple name consists in traversing the homonym chain, starting
174 -- from the names table. If an entry is immediately visible, it is the one
175 -- designated by the identifier. If only potentially use-visible entities
176 -- are on the chain, we must verify that they do not hide each other. If
177 -- the entity we find is overloadable, we collect all other overloadable
178 -- entities on the chain as long as they are not hidden.
180 -- To resolve expanded names, we must find the entity at the intersection
181 -- of the entity chain for the scope (the prefix) and the homonym chain
182 -- for the selector. In general, homonym chains will be much shorter than
183 -- entity chains, so it is preferable to start from the names table as
184 -- well. If the entity found is overloadable, we must collect all other
185 -- interpretations that are defined in the scope denoted by the prefix.
187 -- For records, protected types, and tasks, their local entities are
188 -- removed from visibility chains on exit from the corresponding scope.
189 -- From the outside, these entities are always accessed by selected
190 -- notation, and the entity chain for the record type, protected type,
191 -- etc. is traversed sequentially in order to find the designated entity.
193 -- The discriminants of a type and the operations of a protected type or
194 -- task are unchained on exit from the first view of the type, (such as
195 -- a private or incomplete type declaration, or a protected type speci-
196 -- fication) and re-chained when compiling the second view.
198 -- In the case of operators, we do not make operators on derived types
199 -- explicit. As a result, the notation P."+" may denote either a user-
200 -- defined function with name "+", or else an implicit declaration of the
201 -- operator "+" in package P. The resolution of expanded names always
202 -- tries to resolve an operator name as such an implicitly defined entity,
203 -- in addition to looking for explicit declarations.
205 -- All forms of names that denote entities (simple names, expanded names,
206 -- character literals in some cases) have a Entity attribute, which
207 -- identifies the entity denoted by the name.
209 ---------------------
210 -- The Scope Stack --
211 ---------------------
213 -- The Scope stack keeps track of the scopes currently been compiled.
214 -- Every entity that contains declarations (including records) is placed
215 -- on the scope stack while it is being processed, and removed at the end.
216 -- Whenever a non-package scope is exited, the entities defined therein
217 -- are removed from the visibility table, so that entities in outer scopes
218 -- become visible (see previous description). On entry to Sem, the scope
219 -- stack only contains the package Standard. As usual, subunits complicate
220 -- this picture ever so slightly.
222 -- The Rtsfind mechanism can force a call to Semantics while another
223 -- compilation is in progress. The unit retrieved by Rtsfind must be
224 -- compiled in its own context, and has no access to the visibility of
225 -- the unit currently being compiled. The procedures Save_Scope_Stack and
226 -- Restore_Scope_Stack make entities in current open scopes invisible
227 -- before compiling the retrieved unit, and restore the compilation
228 -- environment afterwards.
230 ------------------------
231 -- Compiling subunits --
232 ------------------------
234 -- Subunits must be compiled in the environment of the corresponding stub,
235 -- that is to say with the same visibility into the parent (and its
236 -- context) that is available at the point of the stub declaration, but
237 -- with the additional visibility provided by the context clause of the
238 -- subunit itself. As a result, compilation of a subunit forces compilation
239 -- of the parent (see description in lib-). At the point of the stub
240 -- declaration, Analyze is called recursively to compile the proper body of
241 -- the subunit, but without reinitializing the names table, nor the scope
242 -- stack (i.e. standard is not pushed on the stack). In this fashion the
243 -- context of the subunit is added to the context of the parent, and the
244 -- subunit is compiled in the correct environment. Note that in the course
245 -- of processing the context of a subunit, Standard will appear twice on
246 -- the scope stack: once for the parent of the subunit, and once for the
247 -- unit in the context clause being compiled. However, the two sets of
248 -- entities are not linked by homonym chains, so that the compilation of
249 -- any context unit happens in a fresh visibility environment.
251 -------------------------------
252 -- Processing of USE Clauses --
253 -------------------------------
255 -- Every defining occurrence has a flag indicating if it is potentially use
256 -- visible. Resolution of simple names examines this flag. The processing
257 -- of use clauses consists in setting this flag on all visible entities
258 -- defined in the corresponding package. On exit from the scope of the use
259 -- clause, the corresponding flag must be reset. However, a package may
260 -- appear in several nested use clauses (pathological but legal, alas!)
261 -- which forces us to use a slightly more involved scheme:
263 -- a) The defining occurrence for a package holds a flag -In_Use- to
264 -- indicate that it is currently in the scope of a use clause. If a
265 -- redundant use clause is encountered, then the corresponding occurrence
266 -- of the package name is flagged -Redundant_Use-.
268 -- b) On exit from a scope, the use clauses in its declarative part are
269 -- scanned. The visibility flag is reset in all entities declared in
270 -- package named in a use clause, as long as the package is not flagged
271 -- as being in a redundant use clause (in which case the outer use
272 -- clause is still in effect, and the direct visibility of its entities
273 -- must be retained).
275 -- Note that entities are not removed from their homonym chains on exit
276 -- from the package specification. A subsequent use clause does not need
277 -- to rechain the visible entities, but only to establish their direct
280 -----------------------------------
281 -- Handling private declarations --
282 -----------------------------------
284 -- The principle that each entity has a single defining occurrence clashes
285 -- with the presence of two separate definitions for private types: the
286 -- first is the private type declaration, and second is the full type
287 -- declaration. It is important that all references to the type point to
288 -- the same defining occurrence, namely the first one. To enforce the two
289 -- separate views of the entity, the corresponding information is swapped
290 -- between the two declarations. Outside of the package, the defining
291 -- occurrence only contains the private declaration information, while in
292 -- the private part and the body of the package the defining occurrence
293 -- contains the full declaration. To simplify the swap, the defining
294 -- occurrence that currently holds the private declaration points to the
295 -- full declaration. During semantic processing the defining occurrence
296 -- also points to a list of private dependents, that is to say access types
297 -- or composite types whose designated types or component types are
298 -- subtypes or derived types of the private type in question. After the
299 -- full declaration has been seen, the private dependents are updated to
300 -- indicate that they have full definitions.
302 ------------------------------------
303 -- Handling of Undefined Messages --
304 ------------------------------------
306 -- In normal mode, only the first use of an undefined identifier generates
307 -- a message. The table Urefs is used to record error messages that have
308 -- been issued so that second and subsequent ones do not generate further
309 -- messages. However, the second reference causes text to be added to the
310 -- original undefined message noting "(more references follow)". The
311 -- full error list option (-gnatf) forces messages to be generated for
312 -- every reference and disconnects the use of this table.
314 type Uref_Entry is record
316 -- Node for identifier for which original message was posted. The
317 -- Chars field of this identifier is used to detect later references
318 -- to the same identifier.
321 -- Records error message Id of original undefined message. Reset to
322 -- No_Error_Msg after the second occurrence, where it is used to add
323 -- text to the original message as described above.
326 -- Set if the message is not visible rather than undefined
329 -- Records location of error message. Used to make sure that we do
330 -- not consider a, b : undefined as two separate instances, which
331 -- would otherwise happen, since the parser converts this sequence
332 -- to a : undefined; b : undefined.
336 package Urefs is new Table.Table (
337 Table_Component_Type => Uref_Entry,
338 Table_Index_Type => Nat,
339 Table_Low_Bound => 1,
341 Table_Increment => 100,
342 Table_Name => "Urefs");
344 Candidate_Renaming : Entity_Id;
345 -- Holds a candidate interpretation that appears in a subprogram renaming
346 -- declaration and does not match the given specification, but matches at
347 -- least on the first formal. Allows better error message when given
348 -- specification omits defaulted parameters, a common error.
350 -----------------------
351 -- Local Subprograms --
352 -----------------------
354 procedure Analyze_Generic_Renaming
357 -- Common processing for all three kinds of generic renaming declarations.
358 -- Enter new name and indicate that it renames the generic unit.
360 procedure Analyze_Renamed_Character
364 -- Renamed entity is given by a character literal, which must belong
365 -- to the return type of the new entity. Is_Body indicates whether the
366 -- declaration is a renaming_as_body. If the original declaration has
367 -- already been frozen (because of an intervening body, e.g.) the body of
368 -- the function must be built now. The same applies to the following
369 -- various renaming procedures.
371 procedure Analyze_Renamed_Dereference
375 -- Renamed entity is given by an explicit dereference. Prefix must be a
376 -- conformant access_to_subprogram type.
378 procedure Analyze_Renamed_Entry
382 -- If the renamed entity in a subprogram renaming is an entry or protected
383 -- subprogram, build a body for the new entity whose only statement is a
384 -- call to the renamed entity.
386 procedure Analyze_Renamed_Family_Member
390 -- Used when the renamed entity is an indexed component. The prefix must
391 -- denote an entry family.
393 procedure Analyze_Renamed_Primitive_Operation
397 -- If the renamed entity in a subprogram renaming is a primitive operation
398 -- or a class-wide operation in prefix form, save the target object, which
399 -- must be added to the list of actuals in any subsequent call.
401 function Applicable_Use (Pack_Name : Node_Id) return Boolean;
402 -- Common code to Use_One_Package and Set_Use, to determine whether use
403 -- clause must be processed. Pack_Name is an entity name that references
404 -- the package in question.
406 procedure Attribute_Renaming (N : Node_Id);
407 -- Analyze renaming of attribute as subprogram. The renaming declaration N
408 -- is rewritten as a subprogram body that returns the attribute reference
409 -- applied to the formals of the function.
411 procedure Set_Entity_Or_Discriminal (N : Node_Id; E : Entity_Id);
412 -- Set Entity, with style check if need be. For a discriminant reference,
413 -- replace by the corresponding discriminal, i.e. the parameter of the
414 -- initialization procedure that corresponds to the discriminant.
416 procedure Check_Frozen_Renaming (N : Node_Id; Subp : Entity_Id);
417 -- A renaming_as_body may occur after the entity of the original decla-
418 -- ration has been frozen. In that case, the body of the new entity must
419 -- be built now, because the usual mechanism of building the renamed
420 -- body at the point of freezing will not work. Subp is the subprogram
421 -- for which N provides the Renaming_As_Body.
423 procedure Check_In_Previous_With_Clause
426 -- N is a use_package clause and Nam the package name, or N is a use_type
427 -- clause and Nam is the prefix of the type name. In either case, verify
428 -- that the package is visible at that point in the context: either it
429 -- appears in a previous with_clause, or because it is a fully qualified
430 -- name and the root ancestor appears in a previous with_clause.
432 procedure Check_Library_Unit_Renaming (N : Node_Id; Old_E : Entity_Id);
433 -- Verify that the entity in a renaming declaration that is a library unit
434 -- is itself a library unit and not a nested unit or subunit. Also check
435 -- that if the renaming is a child unit of a generic parent, then the
436 -- renamed unit must also be a child unit of that parent. Finally, verify
437 -- that a renamed generic unit is not an implicit child declared within
438 -- an instance of the parent.
440 procedure Chain_Use_Clause (N : Node_Id);
441 -- Chain use clause onto list of uses clauses headed by First_Use_Clause in
442 -- the proper scope table entry. This is usually the current scope, but it
443 -- will be an inner scope when installing the use clauses of the private
444 -- declarations of a parent unit prior to compiling the private part of a
445 -- child unit. This chain is traversed when installing/removing use clauses
446 -- when compiling a subunit or instantiating a generic body on the fly,
447 -- when it is necessary to save and restore full environments.
449 function Has_Implicit_Character_Literal (N : Node_Id) return Boolean;
450 -- Find a type derived from Character or Wide_Character in the prefix of N.
451 -- Used to resolved qualified names whose selector is a character literal.
453 function Has_Private_With (E : Entity_Id) return Boolean;
454 -- Ada 2005 (AI-262): Determines if the current compilation unit has a
455 -- private with on E.
457 procedure Find_Expanded_Name (N : Node_Id);
458 -- The input is a selected component is known to be expanded name. Verify
459 -- legality of selector given the scope denoted by prefix, and change node
460 -- N into a expanded name with a properly set Entity field.
462 function Find_Renamed_Entity
466 Is_Actual : Boolean := False) return Entity_Id;
467 -- Find the renamed entity that corresponds to the given parameter profile
468 -- in a subprogram renaming declaration. The renamed entity may be an
469 -- operator, a subprogram, an entry, or a protected operation. Is_Actual
470 -- indicates that the renaming is the one generated for an actual subpro-
471 -- gram in an instance, for which special visibility checks apply.
473 function Has_Implicit_Operator (N : Node_Id) return Boolean;
474 -- N is an expanded name whose selector is an operator name (e.g. P."+").
475 -- declarative part contains an implicit declaration of an operator if it
476 -- has a declaration of a type to which one of the predefined operators
477 -- apply. The existence of this routine is an implementation artifact. A
478 -- more straightforward but more space-consuming choice would be to make
479 -- all inherited operators explicit in the symbol table.
481 procedure Inherit_Renamed_Profile (New_S : Entity_Id; Old_S : Entity_Id);
482 -- A subprogram defined by a renaming declaration inherits the parameter
483 -- profile of the renamed entity. The subtypes given in the subprogram
484 -- specification are discarded and replaced with those of the renamed
485 -- subprogram, which are then used to recheck the default values.
487 function Is_Appropriate_For_Record (T : Entity_Id) return Boolean;
488 -- Prefix is appropriate for record if it is of a record type, or an access
491 function Is_Appropriate_For_Entry_Prefix (T : Entity_Id) return Boolean;
492 -- True if it is of a task type, a protected type, or else an access to one
495 procedure Note_Redundant_Use (Clause : Node_Id);
496 -- Mark the name in a use clause as redundant if the corresponding entity
497 -- is already use-visible. Emit a warning if the use clause comes from
498 -- source and the proper warnings are enabled.
500 procedure Premature_Usage (N : Node_Id);
501 -- Diagnose usage of an entity before it is visible
503 procedure Use_One_Package (P : Entity_Id; N : Node_Id);
504 -- Make visible entities declared in package P potentially use-visible
505 -- in the current context. Also used in the analysis of subunits, when
506 -- re-installing use clauses of parent units. N is the use_clause that
507 -- names P (and possibly other packages).
509 procedure Use_One_Type (Id : Node_Id);
510 -- Id is the subtype mark from a use type clause. This procedure makes
511 -- the primitive operators of the type potentially use-visible.
513 procedure Write_Info;
514 -- Write debugging information on entities declared in current scope
516 --------------------------------
517 -- Analyze_Exception_Renaming --
518 --------------------------------
520 -- The language only allows a single identifier, but the tree holds an
521 -- identifier list. The parser has already issued an error message if
522 -- there is more than one element in the list.
524 procedure Analyze_Exception_Renaming (N : Node_Id) is
525 Id : constant Node_Id := Defining_Identifier (N);
526 Nam : constant Node_Id := Name (N);
532 Set_Ekind (Id, E_Exception);
533 Set_Exception_Code (Id, Uint_0);
534 Set_Etype (Id, Standard_Exception_Type);
535 Set_Is_Pure (Id, Is_Pure (Current_Scope));
537 if not Is_Entity_Name (Nam) or else
538 Ekind (Entity (Nam)) /= E_Exception
540 Error_Msg_N ("invalid exception name in renaming", Nam);
542 if Present (Renamed_Object (Entity (Nam))) then
543 Set_Renamed_Object (Id, Renamed_Object (Entity (Nam)));
545 Set_Renamed_Object (Id, Entity (Nam));
548 end Analyze_Exception_Renaming;
550 ---------------------------
551 -- Analyze_Expanded_Name --
552 ---------------------------
554 procedure Analyze_Expanded_Name (N : Node_Id) is
556 -- If the entity pointer is already set, this is an internal node, or a
557 -- node that is analyzed more than once, after a tree modification. In
558 -- such a case there is no resolution to perform, just set the type. For
559 -- completeness, analyze prefix as well.
561 if Present (Entity (N)) then
562 if Is_Type (Entity (N)) then
563 Set_Etype (N, Entity (N));
565 Set_Etype (N, Etype (Entity (N)));
568 Analyze (Prefix (N));
571 Find_Expanded_Name (N);
573 end Analyze_Expanded_Name;
575 ---------------------------------------
576 -- Analyze_Generic_Function_Renaming --
577 ---------------------------------------
579 procedure Analyze_Generic_Function_Renaming (N : Node_Id) is
581 Analyze_Generic_Renaming (N, E_Generic_Function);
582 end Analyze_Generic_Function_Renaming;
584 --------------------------------------
585 -- Analyze_Generic_Package_Renaming --
586 --------------------------------------
588 procedure Analyze_Generic_Package_Renaming (N : Node_Id) is
590 -- Apply the Text_IO Kludge here, since we may be renaming one of the
591 -- subpackages of Text_IO, then join common routine.
593 Text_IO_Kludge (Name (N));
595 Analyze_Generic_Renaming (N, E_Generic_Package);
596 end Analyze_Generic_Package_Renaming;
598 ----------------------------------------
599 -- Analyze_Generic_Procedure_Renaming --
600 ----------------------------------------
602 procedure Analyze_Generic_Procedure_Renaming (N : Node_Id) is
604 Analyze_Generic_Renaming (N, E_Generic_Procedure);
605 end Analyze_Generic_Procedure_Renaming;
607 ------------------------------
608 -- Analyze_Generic_Renaming --
609 ------------------------------
611 procedure Analyze_Generic_Renaming
615 New_P : constant Entity_Id := Defining_Entity (N);
617 Inst : Boolean := False; -- prevent junk warning
620 if Name (N) = Error then
624 Generate_Definition (New_P);
626 if Current_Scope /= Standard_Standard then
627 Set_Is_Pure (New_P, Is_Pure (Current_Scope));
630 if Nkind (Name (N)) = N_Selected_Component then
631 Check_Generic_Child_Unit (Name (N), Inst);
636 if not Is_Entity_Name (Name (N)) then
637 Error_Msg_N ("expect entity name in renaming declaration", Name (N));
640 Old_P := Entity (Name (N));
644 Set_Ekind (New_P, K);
646 if Etype (Old_P) = Any_Type then
649 elsif Ekind (Old_P) /= K then
650 Error_Msg_N ("invalid generic unit name", Name (N));
653 if Present (Renamed_Object (Old_P)) then
654 Set_Renamed_Object (New_P, Renamed_Object (Old_P));
656 Set_Renamed_Object (New_P, Old_P);
659 Set_Is_Pure (New_P, Is_Pure (Old_P));
660 Set_Is_Preelaborated (New_P, Is_Preelaborated (Old_P));
662 Set_Etype (New_P, Etype (Old_P));
663 Set_Has_Completion (New_P);
665 if In_Open_Scopes (Old_P) then
666 Error_Msg_N ("within its scope, generic denotes its instance", N);
669 Check_Library_Unit_Renaming (N, Old_P);
671 end Analyze_Generic_Renaming;
673 -----------------------------
674 -- Analyze_Object_Renaming --
675 -----------------------------
677 procedure Analyze_Object_Renaming (N : Node_Id) is
678 Id : constant Entity_Id := Defining_Identifier (N);
680 Nam : constant Node_Id := Name (N);
684 function In_Generic_Scope (E : Entity_Id) return Boolean;
685 -- Determine whether entity E is inside a generic cope
687 ----------------------
688 -- In_Generic_Scope --
689 ----------------------
691 function In_Generic_Scope (E : Entity_Id) return Boolean is
696 while Present (S) and then S /= Standard_Standard loop
697 if Is_Generic_Unit (S) then
705 end In_Generic_Scope;
707 -- Start of processing for Analyze_Object_Renaming
714 Set_Is_Pure (Id, Is_Pure (Current_Scope));
717 -- The renaming of a component that depends on a discriminant requires
718 -- an actual subtype, because in subsequent use of the object Gigi will
719 -- be unable to locate the actual bounds. This explicit step is required
720 -- when the renaming is generated in removing side effects of an
721 -- already-analyzed expression.
723 if Nkind (Nam) = N_Selected_Component
724 and then Analyzed (Nam)
727 Dec := Build_Actual_Subtype_Of_Component (Etype (Nam), Nam);
729 if Present (Dec) then
730 Insert_Action (N, Dec);
731 T := Defining_Identifier (Dec);
735 -- Complete analysis of the subtype mark in any case, for ASIS use
737 if Present (Subtype_Mark (N)) then
738 Find_Type (Subtype_Mark (N));
741 elsif Present (Subtype_Mark (N)) then
742 Find_Type (Subtype_Mark (N));
743 T := Entity (Subtype_Mark (N));
746 if Nkind (Nam) = N_Type_Conversion
747 and then not Is_Tagged_Type (T)
750 ("renaming of conversion only allowed for tagged types", Nam);
755 -- Check that a class-wide object is not being renamed as an object
756 -- of a specific type. The test for access types is needed to exclude
757 -- cases where the renamed object is a dynamically tagged access
758 -- result, such as occurs in certain expansions.
760 if Is_Tagged_Type (T) then
761 Check_Dynamically_Tagged_Expression
767 -- Ada 2005 (AI-230/AI-254): Access renaming
769 else pragma Assert (Present (Access_Definition (N)));
770 T := Access_Definition
772 N => Access_Definition (N));
776 -- Ada 2005 AI05-105: if the declaration has an anonymous access
777 -- type, the renamed object must also have an anonymous type, and
778 -- this is a name resolution rule. This was implicit in the last
779 -- part of the first sentence in 8.5.1.(3/2), and is made explicit
780 -- by this recent AI.
782 if not Is_Overloaded (Nam) then
783 if Ekind (Etype (Nam)) /= Ekind (T) then
785 ("expect anonymous access type in object renaming", N);
792 Typ : Entity_Id := Empty;
793 Seen : Boolean := False;
796 Get_First_Interp (Nam, I, It);
797 while Present (It.Typ) loop
799 -- Renaming is ambiguous if more than one candidate
800 -- interpretation is type-conformant with the context.
802 if Ekind (It.Typ) = Ekind (T) then
803 if Ekind (T) = E_Anonymous_Access_Subprogram_Type
806 (Designated_Type (T), Designated_Type (It.Typ))
812 ("ambiguous expression in renaming", Nam);
815 elsif Ekind (T) = E_Anonymous_Access_Type
817 Covers (Designated_Type (T), Designated_Type (It.Typ))
823 ("ambiguous expression in renaming", Nam);
827 if Covers (T, It.Typ) then
829 Set_Etype (Nam, Typ);
830 Set_Is_Overloaded (Nam, False);
834 Get_Next_Interp (I, It);
841 -- Ada 2005 (AI-231): "In the case where the type is defined by an
842 -- access_definition, the renamed entity shall be of an access-to-
843 -- constant type if and only if the access_definition defines an
844 -- access-to-constant type" ARM 8.5.1(4)
846 if Constant_Present (Access_Definition (N))
847 and then not Is_Access_Constant (Etype (Nam))
849 Error_Msg_N ("(Ada 2005): the renamed object is not "
850 & "access-to-constant (RM 8.5.1(6))", N);
852 elsif not Constant_Present (Access_Definition (N))
853 and then Is_Access_Constant (Etype (Nam))
855 Error_Msg_N ("(Ada 2005): the renamed object is not "
856 & "access-to-variable (RM 8.5.1(6))", N);
859 if Is_Access_Subprogram_Type (Etype (Nam)) then
860 Check_Subtype_Conformant
861 (Designated_Type (T), Designated_Type (Etype (Nam)));
863 elsif not Subtypes_Statically_Match
864 (Designated_Type (T), Designated_Type (Etype (Nam)))
867 ("subtype of renamed object does not statically match", N);
871 -- Special processing for renaming function return object. Some errors
872 -- and warnings are produced only for calls that come from source.
874 if Nkind (Nam) = N_Function_Call then
877 -- Usage is illegal in Ada 83
880 if Comes_From_Source (Nam) then
882 ("(Ada 83) cannot rename function return object", Nam);
885 -- In Ada 95, warn for odd case of renaming parameterless function
886 -- call if this is not a limited type (where this is useful).
889 if Warn_On_Object_Renames_Function
890 and then No (Parameter_Associations (Nam))
891 and then not Is_Limited_Type (Etype (Nam))
892 and then Comes_From_Source (Nam)
895 ("?renaming function result object is suspicious", Nam);
897 ("\?function & will be called only once", Nam,
898 Entity (Name (Nam)));
899 Error_Msg_N -- CODEFIX
900 ("\?suggest using an initialized constant object instead",
904 -- If the function call returns an unconstrained type, we must
905 -- build a constrained subtype for the new entity, in a way
906 -- similar to what is done for an object declaration with an
907 -- unconstrained nominal type.
909 if Is_Composite_Type (Etype (Nam))
910 and then not Is_Constrained (Etype (Nam))
911 and then not Has_Unknown_Discriminants (Etype (Nam))
912 and then Expander_Active
915 Loc : constant Source_Ptr := Sloc (N);
916 Subt : constant Entity_Id := Make_Temporary (Loc, 'T');
918 Remove_Side_Effects (Nam);
920 Make_Subtype_Declaration (Loc,
921 Defining_Identifier => Subt,
922 Subtype_Indication =>
923 Make_Subtype_From_Expr (Nam, Etype (Nam))));
924 Rewrite (Subtype_Mark (N), New_Occurrence_Of (Subt, Loc));
925 Set_Etype (Nam, Subt);
931 -- An object renaming requires an exact match of the type. Class-wide
932 -- matching is not allowed.
934 if Is_Class_Wide_Type (T)
935 and then Base_Type (Etype (Nam)) /= Base_Type (T)
942 -- (Ada 2005: AI-326): Handle wrong use of incomplete type
944 if Nkind (Nam) = N_Explicit_Dereference
945 and then Ekind (Etype (T2)) = E_Incomplete_Type
947 Error_Msg_NE ("invalid use of incomplete type&", Id, T2);
950 elsif Ekind (Etype (T)) = E_Incomplete_Type then
951 Error_Msg_NE ("invalid use of incomplete type&", Id, T);
957 if Ada_Version >= Ada_2005
958 and then Nkind (Nam) = N_Attribute_Reference
959 and then Attribute_Name (Nam) = Name_Priority
963 elsif Ada_Version >= Ada_2005
964 and then Nkind (Nam) in N_Has_Entity
971 if Nkind (Nam) = N_Attribute_Reference then
972 Nam_Ent := Entity (Prefix (Nam));
974 Nam_Ent := Entity (Nam);
977 Nam_Decl := Parent (Nam_Ent);
979 if Has_Null_Exclusion (N)
980 and then not Has_Null_Exclusion (Nam_Decl)
982 -- Ada 2005 (AI-423): If the object name denotes a generic
983 -- formal object of a generic unit G, and the object renaming
984 -- declaration occurs within the body of G or within the body
985 -- of a generic unit declared within the declarative region
986 -- of G, then the declaration of the formal object of G must
987 -- have a null exclusion or a null-excluding subtype.
989 if Is_Formal_Object (Nam_Ent)
990 and then In_Generic_Scope (Id)
992 if not Can_Never_Be_Null (Etype (Nam_Ent)) then
994 ("renamed formal does not exclude `NULL` "
995 & "(RM 8.5.1(4.6/2))", N);
997 elsif In_Package_Body (Scope (Id)) then
999 ("formal object does not have a null exclusion"
1000 & "(RM 8.5.1(4.6/2))", N);
1003 -- Ada 2005 (AI-423): Otherwise, the subtype of the object name
1004 -- shall exclude null.
1006 elsif not Can_Never_Be_Null (Etype (Nam_Ent)) then
1008 ("renamed object does not exclude `NULL` "
1009 & "(RM 8.5.1(4.6/2))", N);
1011 -- An instance is illegal if it contains a renaming that
1012 -- excludes null, and the actual does not. The renaming
1013 -- declaration has already indicated that the declaration
1014 -- of the renamed actual in the instance will raise
1015 -- constraint_error.
1017 elsif Nkind (Nam_Decl) = N_Object_Declaration
1018 and then In_Instance
1020 (Corresponding_Generic_Association (Nam_Decl))
1021 and then Nkind (Expression (Nam_Decl))
1022 = N_Raise_Constraint_Error
1025 ("renamed actual does not exclude `NULL` "
1026 & "(RM 8.5.1(4.6/2))", N);
1028 -- Finally, if there is a null exclusion, the subtype mark
1029 -- must not be null-excluding.
1031 elsif No (Access_Definition (N))
1032 and then Can_Never_Be_Null (T)
1035 ("`NOT NULL` not allowed (& already excludes null)",
1040 elsif Can_Never_Be_Null (T)
1041 and then not Can_Never_Be_Null (Etype (Nam_Ent))
1044 ("renamed object does not exclude `NULL` "
1045 & "(RM 8.5.1(4.6/2))", N);
1047 elsif Has_Null_Exclusion (N)
1048 and then No (Access_Definition (N))
1049 and then Can_Never_Be_Null (T)
1052 ("`NOT NULL` not allowed (& already excludes null)", N, T);
1057 Set_Ekind (Id, E_Variable);
1058 Init_Size_Align (Id);
1060 if T = Any_Type or else Etype (Nam) = Any_Type then
1063 -- Verify that the renamed entity is an object or a function call. It
1064 -- may have been rewritten in several ways.
1066 elsif Is_Object_Reference (Nam) then
1067 if Comes_From_Source (N)
1068 and then Is_Dependent_Component_Of_Mutable_Object (Nam)
1071 ("illegal renaming of discriminant-dependent component", Nam);
1074 -- A static function call may have been folded into a literal
1076 elsif Nkind (Original_Node (Nam)) = N_Function_Call
1078 -- When expansion is disabled, attribute reference is not
1079 -- rewritten as function call. Otherwise it may be rewritten
1080 -- as a conversion, so check original node.
1082 or else (Nkind (Original_Node (Nam)) = N_Attribute_Reference
1083 and then Is_Function_Attribute_Name
1084 (Attribute_Name (Original_Node (Nam))))
1086 -- Weird but legal, equivalent to renaming a function call.
1087 -- Illegal if the literal is the result of constant-folding an
1088 -- attribute reference that is not a function.
1090 or else (Is_Entity_Name (Nam)
1091 and then Ekind (Entity (Nam)) = E_Enumeration_Literal
1093 Nkind (Original_Node (Nam)) /= N_Attribute_Reference)
1095 or else (Nkind (Nam) = N_Type_Conversion
1096 and then Is_Tagged_Type (Entity (Subtype_Mark (Nam))))
1100 elsif Nkind (Nam) = N_Type_Conversion then
1102 ("renaming of conversion only allowed for tagged types", Nam);
1104 -- Ada 2005 (AI-327)
1106 elsif Ada_Version >= Ada_2005
1107 and then Nkind (Nam) = N_Attribute_Reference
1108 and then Attribute_Name (Nam) = Name_Priority
1112 -- Allow internally generated x'Reference expression
1114 elsif Nkind (Nam) = N_Reference then
1118 Error_Msg_N ("expect object name in renaming", Nam);
1123 if not Is_Variable (Nam) then
1124 Set_Ekind (Id, E_Constant);
1125 Set_Never_Set_In_Source (Id, True);
1126 Set_Is_True_Constant (Id, True);
1129 Set_Renamed_Object (Id, Nam);
1130 end Analyze_Object_Renaming;
1132 ------------------------------
1133 -- Analyze_Package_Renaming --
1134 ------------------------------
1136 procedure Analyze_Package_Renaming (N : Node_Id) is
1137 New_P : constant Entity_Id := Defining_Entity (N);
1142 if Name (N) = Error then
1146 -- Apply Text_IO kludge here since we may be renaming a child of Text_IO
1148 Text_IO_Kludge (Name (N));
1150 if Current_Scope /= Standard_Standard then
1151 Set_Is_Pure (New_P, Is_Pure (Current_Scope));
1157 if Is_Entity_Name (Name (N)) then
1158 Old_P := Entity (Name (N));
1163 if Etype (Old_P) = Any_Type then
1164 Error_Msg_N ("expect package name in renaming", Name (N));
1166 elsif Ekind (Old_P) /= E_Package
1167 and then not (Ekind (Old_P) = E_Generic_Package
1168 and then In_Open_Scopes (Old_P))
1170 if Ekind (Old_P) = E_Generic_Package then
1172 ("generic package cannot be renamed as a package", Name (N));
1174 Error_Msg_Sloc := Sloc (Old_P);
1176 ("expect package name in renaming, found& declared#",
1180 -- Set basic attributes to minimize cascaded errors
1182 Set_Ekind (New_P, E_Package);
1183 Set_Etype (New_P, Standard_Void_Type);
1185 -- Here for OK package renaming
1188 -- Entities in the old package are accessible through the renaming
1189 -- entity. The simplest implementation is to have both packages share
1192 Set_Ekind (New_P, E_Package);
1193 Set_Etype (New_P, Standard_Void_Type);
1195 if Present (Renamed_Object (Old_P)) then
1196 Set_Renamed_Object (New_P, Renamed_Object (Old_P));
1198 Set_Renamed_Object (New_P, Old_P);
1201 Set_Has_Completion (New_P);
1203 Set_First_Entity (New_P, First_Entity (Old_P));
1204 Set_Last_Entity (New_P, Last_Entity (Old_P));
1205 Set_First_Private_Entity (New_P, First_Private_Entity (Old_P));
1206 Check_Library_Unit_Renaming (N, Old_P);
1207 Generate_Reference (Old_P, Name (N));
1209 -- If the renaming is in the visible part of a package, then we set
1210 -- Renamed_In_Spec for the renamed package, to prevent giving
1211 -- warnings about no entities referenced. Such a warning would be
1212 -- overenthusiastic, since clients can see entities in the renamed
1213 -- package via the visible package renaming.
1216 Ent : constant Entity_Id := Cunit_Entity (Current_Sem_Unit);
1218 if Ekind (Ent) = E_Package
1219 and then not In_Private_Part (Ent)
1220 and then In_Extended_Main_Source_Unit (N)
1221 and then Ekind (Old_P) = E_Package
1223 Set_Renamed_In_Spec (Old_P);
1227 -- If this is the renaming declaration of a package instantiation
1228 -- within itself, it is the declaration that ends the list of actuals
1229 -- for the instantiation. At this point, the subtypes that rename
1230 -- the actuals are flagged as generic, to avoid spurious ambiguities
1231 -- if the actuals for two distinct formals happen to coincide. If
1232 -- the actual is a private type, the subtype has a private completion
1233 -- that is flagged in the same fashion.
1235 -- Resolution is identical to what is was in the original generic.
1236 -- On exit from the generic instance, these are turned into regular
1237 -- subtypes again, so they are compatible with types in their class.
1239 if not Is_Generic_Instance (Old_P) then
1242 Spec := Specification (Unit_Declaration_Node (Old_P));
1245 if Nkind (Spec) = N_Package_Specification
1246 and then Present (Generic_Parent (Spec))
1247 and then Old_P = Current_Scope
1248 and then Chars (New_P) = Chars (Generic_Parent (Spec))
1254 E := First_Entity (Old_P);
1259 and then Nkind (Parent (E)) = N_Subtype_Declaration
1261 Set_Is_Generic_Actual_Type (E);
1263 if Is_Private_Type (E)
1264 and then Present (Full_View (E))
1266 Set_Is_Generic_Actual_Type (Full_View (E));
1275 end Analyze_Package_Renaming;
1277 -------------------------------
1278 -- Analyze_Renamed_Character --
1279 -------------------------------
1281 procedure Analyze_Renamed_Character
1286 C : constant Node_Id := Name (N);
1289 if Ekind (New_S) = E_Function then
1290 Resolve (C, Etype (New_S));
1293 Check_Frozen_Renaming (N, New_S);
1297 Error_Msg_N ("character literal can only be renamed as function", N);
1299 end Analyze_Renamed_Character;
1301 ---------------------------------
1302 -- Analyze_Renamed_Dereference --
1303 ---------------------------------
1305 procedure Analyze_Renamed_Dereference
1310 Nam : constant Node_Id := Name (N);
1311 P : constant Node_Id := Prefix (Nam);
1317 if not Is_Overloaded (P) then
1318 if Ekind (Etype (Nam)) /= E_Subprogram_Type
1319 or else not Type_Conformant (Etype (Nam), New_S)
1321 Error_Msg_N ("designated type does not match specification", P);
1330 Get_First_Interp (Nam, Ind, It);
1332 while Present (It.Nam) loop
1334 if Ekind (It.Nam) = E_Subprogram_Type
1335 and then Type_Conformant (It.Nam, New_S)
1337 if Typ /= Any_Id then
1338 Error_Msg_N ("ambiguous renaming", P);
1345 Get_Next_Interp (Ind, It);
1348 if Typ = Any_Type then
1349 Error_Msg_N ("designated type does not match specification", P);
1354 Check_Frozen_Renaming (N, New_S);
1358 end Analyze_Renamed_Dereference;
1360 ---------------------------
1361 -- Analyze_Renamed_Entry --
1362 ---------------------------
1364 procedure Analyze_Renamed_Entry
1369 Nam : constant Node_Id := Name (N);
1370 Sel : constant Node_Id := Selector_Name (Nam);
1374 if Entity (Sel) = Any_Id then
1376 -- Selector is undefined on prefix. Error emitted already
1378 Set_Has_Completion (New_S);
1382 -- Otherwise find renamed entity and build body of New_S as a call to it
1384 Old_S := Find_Renamed_Entity (N, Selector_Name (Nam), New_S);
1386 if Old_S = Any_Id then
1387 Error_Msg_N (" no subprogram or entry matches specification", N);
1390 Check_Subtype_Conformant (New_S, Old_S, N);
1391 Generate_Reference (New_S, Defining_Entity (N), 'b');
1392 Style.Check_Identifier (Defining_Entity (N), New_S);
1395 -- Only mode conformance required for a renaming_as_declaration
1397 Check_Mode_Conformant (New_S, Old_S, N);
1400 Inherit_Renamed_Profile (New_S, Old_S);
1402 -- The prefix can be an arbitrary expression that yields a task type,
1403 -- so it must be resolved.
1405 Resolve (Prefix (Nam), Scope (Old_S));
1408 Set_Convention (New_S, Convention (Old_S));
1409 Set_Has_Completion (New_S, Inside_A_Generic);
1412 Check_Frozen_Renaming (N, New_S);
1414 end Analyze_Renamed_Entry;
1416 -----------------------------------
1417 -- Analyze_Renamed_Family_Member --
1418 -----------------------------------
1420 procedure Analyze_Renamed_Family_Member
1425 Nam : constant Node_Id := Name (N);
1426 P : constant Node_Id := Prefix (Nam);
1430 if (Is_Entity_Name (P) and then Ekind (Entity (P)) = E_Entry_Family)
1431 or else (Nkind (P) = N_Selected_Component
1433 Ekind (Entity (Selector_Name (P))) = E_Entry_Family)
1435 if Is_Entity_Name (P) then
1436 Old_S := Entity (P);
1438 Old_S := Entity (Selector_Name (P));
1441 if not Entity_Matches_Spec (Old_S, New_S) then
1442 Error_Msg_N ("entry family does not match specification", N);
1445 Check_Subtype_Conformant (New_S, Old_S, N);
1446 Generate_Reference (New_S, Defining_Entity (N), 'b');
1447 Style.Check_Identifier (Defining_Entity (N), New_S);
1451 Error_Msg_N ("no entry family matches specification", N);
1454 Set_Has_Completion (New_S, Inside_A_Generic);
1457 Check_Frozen_Renaming (N, New_S);
1459 end Analyze_Renamed_Family_Member;
1461 -----------------------------------------
1462 -- Analyze_Renamed_Primitive_Operation --
1463 -----------------------------------------
1465 procedure Analyze_Renamed_Primitive_Operation
1474 Ctyp : Conformance_Type) return Boolean;
1475 -- Verify that the signatures of the renamed entity and the new entity
1476 -- match. The first formal of the renamed entity is skipped because it
1477 -- is the target object in any subsequent call.
1481 Ctyp : Conformance_Type) return Boolean
1487 if Ekind (Subp) /= Ekind (New_S) then
1491 Old_F := Next_Formal (First_Formal (Subp));
1492 New_F := First_Formal (New_S);
1493 while Present (Old_F) and then Present (New_F) loop
1494 if not Conforming_Types (Etype (Old_F), Etype (New_F), Ctyp) then
1498 if Ctyp >= Mode_Conformant
1499 and then Ekind (Old_F) /= Ekind (New_F)
1504 Next_Formal (New_F);
1505 Next_Formal (Old_F);
1512 if not Is_Overloaded (Selector_Name (Name (N))) then
1513 Old_S := Entity (Selector_Name (Name (N)));
1515 if not Conforms (Old_S, Type_Conformant) then
1520 -- Find the operation that matches the given signature
1528 Get_First_Interp (Selector_Name (Name (N)), Ind, It);
1530 while Present (It.Nam) loop
1531 if Conforms (It.Nam, Type_Conformant) then
1535 Get_Next_Interp (Ind, It);
1540 if Old_S = Any_Id then
1541 Error_Msg_N (" no subprogram or entry matches specification", N);
1545 if not Conforms (Old_S, Subtype_Conformant) then
1546 Error_Msg_N ("subtype conformance error in renaming", N);
1549 Generate_Reference (New_S, Defining_Entity (N), 'b');
1550 Style.Check_Identifier (Defining_Entity (N), New_S);
1553 -- Only mode conformance required for a renaming_as_declaration
1555 if not Conforms (Old_S, Mode_Conformant) then
1556 Error_Msg_N ("mode conformance error in renaming", N);
1560 -- Inherit_Renamed_Profile (New_S, Old_S);
1562 -- The prefix can be an arbitrary expression that yields an
1563 -- object, so it must be resolved.
1565 Resolve (Prefix (Name (N)));
1567 end Analyze_Renamed_Primitive_Operation;
1569 ---------------------------------
1570 -- Analyze_Subprogram_Renaming --
1571 ---------------------------------
1573 procedure Analyze_Subprogram_Renaming (N : Node_Id) is
1574 Formal_Spec : constant Node_Id := Corresponding_Formal_Spec (N);
1575 Is_Actual : constant Boolean := Present (Formal_Spec);
1576 Inst_Node : Node_Id := Empty;
1577 Nam : constant Node_Id := Name (N);
1579 Old_S : Entity_Id := Empty;
1580 Rename_Spec : Entity_Id;
1581 Save_AV : constant Ada_Version_Type := Ada_Version;
1582 Save_AV_Exp : constant Ada_Version_Type := Ada_Version_Explicit;
1583 Spec : constant Node_Id := Specification (N);
1585 procedure Check_Null_Exclusion
1588 -- Ada 2005 (AI-423): Given renaming Ren of subprogram Sub, check the
1589 -- following AI rules:
1591 -- If Ren is a renaming of a formal subprogram and one of its
1592 -- parameters has a null exclusion, then the corresponding formal
1593 -- in Sub must also have one. Otherwise the subtype of the Sub's
1594 -- formal parameter must exclude null.
1596 -- If Ren is a renaming of a formal function and its return
1597 -- profile has a null exclusion, then Sub's return profile must
1598 -- have one. Otherwise the subtype of Sub's return profile must
1601 function Original_Subprogram (Subp : Entity_Id) return Entity_Id;
1602 -- Find renamed entity when the declaration is a renaming_as_body and
1603 -- the renamed entity may itself be a renaming_as_body. Used to enforce
1604 -- rule that a renaming_as_body is illegal if the declaration occurs
1605 -- before the subprogram it completes is frozen, and renaming indirectly
1606 -- renames the subprogram itself.(Defect Report 8652/0027).
1608 --------------------------
1609 -- Check_Null_Exclusion --
1610 --------------------------
1612 procedure Check_Null_Exclusion
1616 Ren_Formal : Entity_Id;
1617 Sub_Formal : Entity_Id;
1622 Ren_Formal := First_Formal (Ren);
1623 Sub_Formal := First_Formal (Sub);
1624 while Present (Ren_Formal)
1625 and then Present (Sub_Formal)
1627 if Has_Null_Exclusion (Parent (Ren_Formal))
1629 not (Has_Null_Exclusion (Parent (Sub_Formal))
1630 or else Can_Never_Be_Null (Etype (Sub_Formal)))
1633 ("`NOT NULL` required for parameter &",
1634 Parent (Sub_Formal), Sub_Formal);
1637 Next_Formal (Ren_Formal);
1638 Next_Formal (Sub_Formal);
1641 -- Return profile check
1643 if Nkind (Parent (Ren)) = N_Function_Specification
1644 and then Nkind (Parent (Sub)) = N_Function_Specification
1645 and then Has_Null_Exclusion (Parent (Ren))
1647 not (Has_Null_Exclusion (Parent (Sub))
1648 or else Can_Never_Be_Null (Etype (Sub)))
1651 ("return must specify `NOT NULL`",
1652 Result_Definition (Parent (Sub)));
1654 end Check_Null_Exclusion;
1656 -------------------------
1657 -- Original_Subprogram --
1658 -------------------------
1660 function Original_Subprogram (Subp : Entity_Id) return Entity_Id is
1661 Orig_Decl : Node_Id;
1662 Orig_Subp : Entity_Id;
1665 -- First case: renamed entity is itself a renaming
1667 if Present (Alias (Subp)) then
1668 return Alias (Subp);
1671 Nkind (Unit_Declaration_Node (Subp)) = N_Subprogram_Declaration
1673 (Corresponding_Body (Unit_Declaration_Node (Subp)))
1675 -- Check if renamed entity is a renaming_as_body
1678 Unit_Declaration_Node
1679 (Corresponding_Body (Unit_Declaration_Node (Subp)));
1681 if Nkind (Orig_Decl) = N_Subprogram_Renaming_Declaration then
1682 Orig_Subp := Entity (Name (Orig_Decl));
1684 if Orig_Subp = Rename_Spec then
1686 -- Circularity detected
1691 return (Original_Subprogram (Orig_Subp));
1699 end Original_Subprogram;
1701 -- Start of processing for Analyze_Subprogram_Renaming
1704 -- We must test for the attribute renaming case before the Analyze
1705 -- call because otherwise Sem_Attr will complain that the attribute
1706 -- is missing an argument when it is analyzed.
1708 if Nkind (Nam) = N_Attribute_Reference then
1710 -- In the case of an abstract formal subprogram association, rewrite
1711 -- an actual given by a stream attribute as the name of the
1712 -- corresponding stream primitive of the type.
1714 -- In a generic context the stream operations are not generated, and
1715 -- this must be treated as a normal attribute reference, to be
1716 -- expanded in subsequent instantiations.
1718 if Is_Actual and then Is_Abstract_Subprogram (Formal_Spec)
1719 and then Expander_Active
1722 Stream_Prim : Entity_Id;
1723 Prefix_Type : constant Entity_Id := Entity (Prefix (Nam));
1726 -- The class-wide forms of the stream attributes are not
1727 -- primitive dispatching operations (even though they
1728 -- internally dispatch to a stream attribute).
1730 if Is_Class_Wide_Type (Prefix_Type) then
1732 ("attribute must be a primitive dispatching operation",
1737 -- Retrieve the primitive subprogram associated with the
1738 -- attribute. This can only be a stream attribute, since those
1739 -- are the only ones that are dispatching (and the actual for
1740 -- an abstract formal subprogram must be dispatching
1744 case Attribute_Name (Nam) is
1747 Find_Prim_Op (Prefix_Type, TSS_Stream_Input);
1750 Find_Prim_Op (Prefix_Type, TSS_Stream_Output);
1753 Find_Prim_Op (Prefix_Type, TSS_Stream_Read);
1756 Find_Prim_Op (Prefix_Type, TSS_Stream_Write);
1759 ("attribute must be a primitive"
1760 & " dispatching operation", Nam);
1766 -- If no operation was found, and the type is limited,
1767 -- the user should have defined one.
1769 when Program_Error =>
1770 if Is_Limited_Type (Prefix_Type) then
1772 ("stream operation not defined for type&",
1776 -- Otherwise, compiler should have generated default
1783 -- Rewrite the attribute into the name of its corresponding
1784 -- primitive dispatching subprogram. We can then proceed with
1785 -- the usual processing for subprogram renamings.
1788 Prim_Name : constant Node_Id :=
1789 Make_Identifier (Sloc (Nam),
1790 Chars => Chars (Stream_Prim));
1792 Set_Entity (Prim_Name, Stream_Prim);
1793 Rewrite (Nam, Prim_Name);
1798 -- Normal processing for a renaming of an attribute
1801 Attribute_Renaming (N);
1806 -- Check whether this declaration corresponds to the instantiation
1807 -- of a formal subprogram.
1809 -- If this is an instantiation, the corresponding actual is frozen and
1810 -- error messages can be made more precise. If this is a default
1811 -- subprogram, the entity is already established in the generic, and is
1812 -- not retrieved by visibility. If it is a default with a box, the
1813 -- candidate interpretations, if any, have been collected when building
1814 -- the renaming declaration. If overloaded, the proper interpretation is
1815 -- determined in Find_Renamed_Entity. If the entity is an operator,
1816 -- Find_Renamed_Entity applies additional visibility checks.
1819 Inst_Node := Unit_Declaration_Node (Formal_Spec);
1821 if Is_Entity_Name (Nam)
1822 and then Present (Entity (Nam))
1823 and then not Comes_From_Source (Nam)
1824 and then not Is_Overloaded (Nam)
1826 Old_S := Entity (Nam);
1827 New_S := Analyze_Subprogram_Specification (Spec);
1831 if Ekind (Entity (Nam)) = E_Operator then
1835 if Box_Present (Inst_Node) then
1836 Old_S := Find_Renamed_Entity (N, Name (N), New_S, Is_Actual);
1838 -- If there is an immediately visible homonym of the operator
1839 -- and the declaration has a default, this is worth a warning
1840 -- because the user probably did not intend to get the pre-
1841 -- defined operator, visible in the generic declaration. To
1842 -- find if there is an intended candidate, analyze the renaming
1843 -- again in the current context.
1845 elsif Scope (Old_S) = Standard_Standard
1846 and then Present (Default_Name (Inst_Node))
1849 Decl : constant Node_Id := New_Copy_Tree (N);
1853 Set_Entity (Name (Decl), Empty);
1854 Analyze (Name (Decl));
1856 Find_Renamed_Entity (Decl, Name (Decl), New_S, True);
1859 and then In_Open_Scopes (Scope (Hidden))
1860 and then Is_Immediately_Visible (Hidden)
1861 and then Comes_From_Source (Hidden)
1862 and then Hidden /= Old_S
1864 Error_Msg_Sloc := Sloc (Hidden);
1865 Error_Msg_N ("?default subprogram is resolved " &
1866 "in the generic declaration " &
1867 "(RM 12.6(17))", N);
1868 Error_Msg_NE ("\?and will not use & #", N, Hidden);
1876 New_S := Analyze_Subprogram_Specification (Spec);
1880 -- Renamed entity must be analyzed first, to avoid being hidden by
1881 -- new name (which might be the same in a generic instance).
1885 -- The renaming defines a new overloaded entity, which is analyzed
1886 -- like a subprogram declaration.
1888 New_S := Analyze_Subprogram_Specification (Spec);
1891 if Current_Scope /= Standard_Standard then
1892 Set_Is_Pure (New_S, Is_Pure (Current_Scope));
1895 Rename_Spec := Find_Corresponding_Spec (N);
1897 -- Case of Renaming_As_Body
1899 if Present (Rename_Spec) then
1901 -- Renaming declaration is the completion of the declaration of
1902 -- Rename_Spec. We build an actual body for it at the freezing point.
1904 Set_Corresponding_Spec (N, Rename_Spec);
1906 -- Deal with special case of stream functions of abstract types
1909 if Nkind (Unit_Declaration_Node (Rename_Spec)) =
1910 N_Abstract_Subprogram_Declaration
1912 -- Input stream functions are abstract if the object type is
1913 -- abstract. Similarly, all default stream functions for an
1914 -- interface type are abstract. However, these subprograms may
1915 -- receive explicit declarations in representation clauses, making
1916 -- the attribute subprograms usable as defaults in subsequent
1918 -- In this case we rewrite the declaration to make the subprogram
1919 -- non-abstract. We remove the previous declaration, and insert
1920 -- the new one at the point of the renaming, to prevent premature
1921 -- access to unfrozen types. The new declaration reuses the
1922 -- specification of the previous one, and must not be analyzed.
1925 (Is_Primitive (Entity (Nam))
1927 Is_Abstract_Type (Find_Dispatching_Type (Entity (Nam))));
1929 Old_Decl : constant Node_Id :=
1930 Unit_Declaration_Node (Rename_Spec);
1931 New_Decl : constant Node_Id :=
1932 Make_Subprogram_Declaration (Sloc (N),
1934 Relocate_Node (Specification (Old_Decl)));
1937 Insert_After (N, New_Decl);
1938 Set_Is_Abstract_Subprogram (Rename_Spec, False);
1939 Set_Analyzed (New_Decl);
1943 Set_Corresponding_Body (Unit_Declaration_Node (Rename_Spec), New_S);
1945 if Ada_Version = Ada_83 and then Comes_From_Source (N) then
1946 Error_Msg_N ("(Ada 83) renaming cannot serve as a body", N);
1949 Set_Convention (New_S, Convention (Rename_Spec));
1950 Check_Fully_Conformant (New_S, Rename_Spec);
1951 Set_Public_Status (New_S);
1953 -- The specification does not introduce new formals, but only
1954 -- repeats the formals of the original subprogram declaration.
1955 -- For cross-reference purposes, and for refactoring tools, we
1956 -- treat the formals of the renaming declaration as body formals.
1958 Reference_Body_Formals (Rename_Spec, New_S);
1960 -- Indicate that the entity in the declaration functions like the
1961 -- corresponding body, and is not a new entity. The body will be
1962 -- constructed later at the freeze point, so indicate that the
1963 -- completion has not been seen yet.
1965 Set_Ekind (New_S, E_Subprogram_Body);
1966 New_S := Rename_Spec;
1967 Set_Has_Completion (Rename_Spec, False);
1969 -- Ada 2005: check overriding indicator
1971 if Is_Overriding_Operation (Rename_Spec) then
1972 if Must_Not_Override (Specification (N)) then
1974 ("subprogram& overrides inherited operation",
1977 Style_Check and then not Must_Override (Specification (N))
1979 Style.Missing_Overriding (N, Rename_Spec);
1982 elsif Must_Override (Specification (N)) then
1983 Error_Msg_NE ("subprogram& is not overriding", N, Rename_Spec);
1986 -- Normal subprogram renaming (not renaming as body)
1989 Generate_Definition (New_S);
1990 New_Overloaded_Entity (New_S);
1992 if Is_Entity_Name (Nam)
1993 and then Is_Intrinsic_Subprogram (Entity (Nam))
1997 Check_Delayed_Subprogram (New_S);
2001 -- There is no need for elaboration checks on the new entity, which may
2002 -- be called before the next freezing point where the body will appear.
2003 -- Elaboration checks refer to the real entity, not the one created by
2004 -- the renaming declaration.
2006 Set_Kill_Elaboration_Checks (New_S, True);
2008 if Etype (Nam) = Any_Type then
2009 Set_Has_Completion (New_S);
2012 elsif Nkind (Nam) = N_Selected_Component then
2014 -- A prefix of the form A.B can designate an entry of task A, a
2015 -- protected operation of protected object A, or finally a primitive
2016 -- operation of object A. In the later case, A is an object of some
2017 -- tagged type, or an access type that denotes one such. To further
2018 -- distinguish these cases, note that the scope of a task entry or
2019 -- protected operation is type of the prefix.
2021 -- The prefix could be an overloaded function call that returns both
2022 -- kinds of operations. This overloading pathology is left to the
2023 -- dedicated reader ???
2026 T : constant Entity_Id := Etype (Prefix (Nam));
2035 Is_Tagged_Type (Designated_Type (T))))
2036 and then Scope (Entity (Selector_Name (Nam))) /= T
2038 Analyze_Renamed_Primitive_Operation
2039 (N, New_S, Present (Rename_Spec));
2043 -- Renamed entity is an entry or protected operation. For those
2044 -- cases an explicit body is built (at the point of freezing of
2045 -- this entity) that contains a call to the renamed entity.
2047 -- This is not allowed for renaming as body if the renamed
2048 -- spec is already frozen (see RM 8.5.4(5) for details).
2050 if Present (Rename_Spec)
2051 and then Is_Frozen (Rename_Spec)
2054 ("renaming-as-body cannot rename entry as subprogram", N);
2056 ("\since & is already frozen (RM 8.5.4(5))",
2059 Analyze_Renamed_Entry (N, New_S, Present (Rename_Spec));
2066 elsif Nkind (Nam) = N_Explicit_Dereference then
2068 -- Renamed entity is designated by access_to_subprogram expression.
2069 -- Must build body to encapsulate call, as in the entry case.
2071 Analyze_Renamed_Dereference (N, New_S, Present (Rename_Spec));
2074 elsif Nkind (Nam) = N_Indexed_Component then
2075 Analyze_Renamed_Family_Member (N, New_S, Present (Rename_Spec));
2078 elsif Nkind (Nam) = N_Character_Literal then
2079 Analyze_Renamed_Character (N, New_S, Present (Rename_Spec));
2082 elsif not Is_Entity_Name (Nam)
2083 or else not Is_Overloadable (Entity (Nam))
2085 Error_Msg_N ("expect valid subprogram name in renaming", N);
2089 -- Find the renamed entity that matches the given specification. Disable
2090 -- Ada_83 because there is no requirement of full conformance between
2091 -- renamed entity and new entity, even though the same circuit is used.
2093 -- This is a bit of a kludge, which introduces a really irregular use of
2094 -- Ada_Version[_Explicit]. Would be nice to find cleaner way to do this
2097 Ada_Version := Ada_Version_Type'Max (Ada_Version, Ada_95);
2098 Ada_Version_Explicit := Ada_Version;
2101 Old_S := Find_Renamed_Entity (N, Name (N), New_S, Is_Actual);
2103 -- The visible operation may be an inherited abstract operation that
2104 -- was overridden in the private part, in which case a call will
2105 -- dispatch to the overriding operation. Use the overriding one in
2106 -- the renaming declaration, to prevent spurious errors below.
2108 if Is_Overloadable (Old_S)
2109 and then Is_Abstract_Subprogram (Old_S)
2110 and then No (DTC_Entity (Old_S))
2111 and then Present (Alias (Old_S))
2112 and then not Is_Abstract_Subprogram (Alias (Old_S))
2113 and then Is_Overriding_Operation (Alias (Old_S))
2115 Old_S := Alias (Old_S);
2118 -- When the renamed subprogram is overloaded and used as an actual
2119 -- of a generic, its entity is set to the first available homonym.
2120 -- We must first disambiguate the name, then set the proper entity.
2123 and then Is_Overloaded (Nam)
2125 Set_Entity (Nam, Old_S);
2129 -- Most common case: subprogram renames subprogram. No body is generated
2130 -- in this case, so we must indicate the declaration is complete as is.
2131 -- and inherit various attributes of the renamed subprogram.
2133 if No (Rename_Spec) then
2134 Set_Has_Completion (New_S);
2135 Set_Is_Imported (New_S, Is_Imported (Entity (Nam)));
2136 Set_Is_Pure (New_S, Is_Pure (Entity (Nam)));
2137 Set_Is_Preelaborated (New_S, Is_Preelaborated (Entity (Nam)));
2139 -- Ada 2005 (AI-423): Check the consistency of null exclusions
2140 -- between a subprogram and its correct renaming.
2142 -- Note: the Any_Id check is a guard that prevents compiler crashes
2143 -- when performing a null exclusion check between a renaming and a
2144 -- renamed subprogram that has been found to be illegal.
2146 if Ada_Version >= Ada_2005
2147 and then Entity (Nam) /= Any_Id
2149 Check_Null_Exclusion
2151 Sub => Entity (Nam));
2154 -- Enforce the Ada 2005 rule that the renamed entity cannot require
2155 -- overriding. The flag Requires_Overriding is set very selectively
2156 -- and misses some other illegal cases. The additional conditions
2157 -- checked below are sufficient but not necessary ???
2159 -- The rule does not apply to the renaming generated for an actual
2160 -- subprogram in an instance.
2165 -- Guard against previous errors, and omit renamings of predefined
2168 elsif not Ekind_In (Old_S, E_Function, E_Procedure) then
2171 elsif Requires_Overriding (Old_S)
2173 (Is_Abstract_Subprogram (Old_S)
2174 and then Present (Find_Dispatching_Type (Old_S))
2176 not Is_Abstract_Type (Find_Dispatching_Type (Old_S)))
2179 ("renamed entity cannot be "
2180 & "subprogram that requires overriding (RM 8.5.4 (5.1))", N);
2184 if Old_S /= Any_Id then
2186 and then From_Default (N)
2188 -- This is an implicit reference to the default actual
2190 Generate_Reference (Old_S, Nam, Typ => 'i', Force => True);
2192 Generate_Reference (Old_S, Nam);
2195 -- For a renaming-as-body, require subtype conformance, but if the
2196 -- declaration being completed has not been frozen, then inherit the
2197 -- convention of the renamed subprogram prior to checking conformance
2198 -- (unless the renaming has an explicit convention established; the
2199 -- rule stated in the RM doesn't seem to address this ???).
2201 if Present (Rename_Spec) then
2202 Generate_Reference (Rename_Spec, Defining_Entity (Spec), 'b');
2203 Style.Check_Identifier (Defining_Entity (Spec), Rename_Spec);
2205 if not Is_Frozen (Rename_Spec) then
2206 if not Has_Convention_Pragma (Rename_Spec) then
2207 Set_Convention (New_S, Convention (Old_S));
2210 if Ekind (Old_S) /= E_Operator then
2211 Check_Mode_Conformant (New_S, Old_S, Spec);
2214 if Original_Subprogram (Old_S) = Rename_Spec then
2215 Error_Msg_N ("unfrozen subprogram cannot rename itself ", N);
2218 Check_Subtype_Conformant (New_S, Old_S, Spec);
2221 Check_Frozen_Renaming (N, Rename_Spec);
2223 -- Check explicitly that renamed entity is not intrinsic, because
2224 -- in a generic the renamed body is not built. In this case,
2225 -- the renaming_as_body is a completion.
2227 if Inside_A_Generic then
2228 if Is_Frozen (Rename_Spec)
2229 and then Is_Intrinsic_Subprogram (Old_S)
2232 ("subprogram in renaming_as_body cannot be intrinsic",
2236 Set_Has_Completion (Rename_Spec);
2239 elsif Ekind (Old_S) /= E_Operator then
2240 Check_Mode_Conformant (New_S, Old_S);
2243 and then Error_Posted (New_S)
2245 Error_Msg_NE ("invalid actual subprogram: & #!", N, Old_S);
2249 if No (Rename_Spec) then
2251 -- The parameter profile of the new entity is that of the renamed
2252 -- entity: the subtypes given in the specification are irrelevant.
2254 Inherit_Renamed_Profile (New_S, Old_S);
2256 -- A call to the subprogram is transformed into a call to the
2257 -- renamed entity. This is transitive if the renamed entity is
2258 -- itself a renaming.
2260 if Present (Alias (Old_S)) then
2261 Set_Alias (New_S, Alias (Old_S));
2263 Set_Alias (New_S, Old_S);
2266 -- Note that we do not set Is_Intrinsic_Subprogram if we have a
2267 -- renaming as body, since the entity in this case is not an
2268 -- intrinsic (it calls an intrinsic, but we have a real body for
2269 -- this call, and it is in this body that the required intrinsic
2270 -- processing will take place).
2272 -- Also, if this is a renaming of inequality, the renamed operator
2273 -- is intrinsic, but what matters is the corresponding equality
2274 -- operator, which may be user-defined.
2276 Set_Is_Intrinsic_Subprogram
2278 Is_Intrinsic_Subprogram (Old_S)
2280 (Chars (Old_S) /= Name_Op_Ne
2281 or else Ekind (Old_S) = E_Operator
2283 Is_Intrinsic_Subprogram
2284 (Corresponding_Equality (Old_S))));
2286 if Ekind (Alias (New_S)) = E_Operator then
2287 Set_Has_Delayed_Freeze (New_S, False);
2290 -- If the renaming corresponds to an association for an abstract
2291 -- formal subprogram, then various attributes must be set to
2292 -- indicate that the renaming is an abstract dispatching operation
2293 -- with a controlling type.
2295 if Is_Actual and then Is_Abstract_Subprogram (Formal_Spec) then
2297 -- Mark the renaming as abstract here, so Find_Dispatching_Type
2298 -- see it as corresponding to a generic association for a
2299 -- formal abstract subprogram
2301 Set_Is_Abstract_Subprogram (New_S);
2304 New_S_Ctrl_Type : constant Entity_Id :=
2305 Find_Dispatching_Type (New_S);
2306 Old_S_Ctrl_Type : constant Entity_Id :=
2307 Find_Dispatching_Type (Old_S);
2310 if Old_S_Ctrl_Type /= New_S_Ctrl_Type then
2312 ("actual must be dispatching subprogram for type&",
2313 Nam, New_S_Ctrl_Type);
2316 Set_Is_Dispatching_Operation (New_S);
2317 Check_Controlling_Formals (New_S_Ctrl_Type, New_S);
2319 -- If the actual in the formal subprogram is itself a
2320 -- formal abstract subprogram association, there's no
2321 -- dispatch table component or position to inherit.
2323 if Present (DTC_Entity (Old_S)) then
2324 Set_DTC_Entity (New_S, DTC_Entity (Old_S));
2325 Set_DT_Position (New_S, DT_Position (Old_S));
2333 and then (Old_S = New_S
2334 or else (Nkind (Nam) /= N_Expanded_Name
2335 and then Chars (Old_S) = Chars (New_S)))
2337 Error_Msg_N ("subprogram cannot rename itself", N);
2340 Set_Convention (New_S, Convention (Old_S));
2342 if Is_Abstract_Subprogram (Old_S) then
2343 if Present (Rename_Spec) then
2345 ("a renaming-as-body cannot rename an abstract subprogram",
2347 Set_Has_Completion (Rename_Spec);
2349 Set_Is_Abstract_Subprogram (New_S);
2353 Check_Library_Unit_Renaming (N, Old_S);
2355 -- Pathological case: procedure renames entry in the scope of its
2356 -- task. Entry is given by simple name, but body must be built for
2357 -- procedure. Of course if called it will deadlock.
2359 if Ekind (Old_S) = E_Entry then
2360 Set_Has_Completion (New_S, False);
2361 Set_Alias (New_S, Empty);
2365 Freeze_Before (N, Old_S);
2366 Set_Has_Delayed_Freeze (New_S, False);
2367 Freeze_Before (N, New_S);
2369 -- An abstract subprogram is only allowed as an actual in the case
2370 -- where the formal subprogram is also abstract.
2372 if (Ekind (Old_S) = E_Procedure or else Ekind (Old_S) = E_Function)
2373 and then Is_Abstract_Subprogram (Old_S)
2374 and then not Is_Abstract_Subprogram (Formal_Spec)
2377 ("abstract subprogram not allowed as generic actual", Nam);
2382 -- A common error is to assume that implicit operators for types are
2383 -- defined in Standard, or in the scope of a subtype. In those cases
2384 -- where the renamed entity is given with an expanded name, it is
2385 -- worth mentioning that operators for the type are not declared in
2386 -- the scope given by the prefix.
2388 if Nkind (Nam) = N_Expanded_Name
2389 and then Nkind (Selector_Name (Nam)) = N_Operator_Symbol
2390 and then Scope (Entity (Nam)) = Standard_Standard
2393 T : constant Entity_Id :=
2394 Base_Type (Etype (First_Formal (New_S)));
2396 Error_Msg_Node_2 := Prefix (Nam);
2398 ("operator for type& is not declared in&", Prefix (Nam), T);
2403 ("no visible subprogram matches the specification for&",
2407 if Present (Candidate_Renaming) then
2414 F1 := First_Formal (Candidate_Renaming);
2415 F2 := First_Formal (New_S);
2416 T1 := First_Subtype (Etype (F1));
2418 while Present (F1) and then Present (F2) loop
2423 if Present (F1) and then Present (Default_Value (F1)) then
2424 if Present (Next_Formal (F1)) then
2426 ("\missing specification for &" &
2427 " and other formals with defaults", Spec, F1);
2430 ("\missing specification for &", Spec, F1);
2434 if Nkind (Nam) = N_Operator_Symbol
2435 and then From_Default (N)
2437 Error_Msg_Node_2 := T1;
2439 ("default & on & is not directly visible",
2446 -- Ada 2005 AI 404: if the new subprogram is dispatching, verify that
2447 -- controlling access parameters are known non-null for the renamed
2448 -- subprogram. Test also applies to a subprogram instantiation that
2449 -- is dispatching. Test is skipped if some previous error was detected
2450 -- that set Old_S to Any_Id.
2452 if Ada_Version >= Ada_2005
2453 and then Old_S /= Any_Id
2454 and then not Is_Dispatching_Operation (Old_S)
2455 and then Is_Dispatching_Operation (New_S)
2462 Old_F := First_Formal (Old_S);
2463 New_F := First_Formal (New_S);
2464 while Present (Old_F) loop
2465 if Ekind (Etype (Old_F)) = E_Anonymous_Access_Type
2466 and then Is_Controlling_Formal (New_F)
2467 and then not Can_Never_Be_Null (Old_F)
2469 Error_Msg_N ("access parameter is controlling,", New_F);
2471 ("\corresponding parameter of& "
2472 & "must be explicitly null excluding", New_F, Old_S);
2475 Next_Formal (Old_F);
2476 Next_Formal (New_F);
2481 -- A useful warning, suggested by Ada Bug Finder (Ada-Europe 2005)
2482 -- is to warn if an operator is being renamed as a different operator.
2484 if Comes_From_Source (N)
2485 and then Present (Old_S)
2486 and then Nkind (Old_S) = N_Defining_Operator_Symbol
2487 and then Nkind (New_S) = N_Defining_Operator_Symbol
2488 and then Chars (Old_S) /= Chars (New_S)
2491 ("?& is being renamed as a different operator",
2495 -- Check for renaming of obsolescent subprogram
2497 Check_Obsolescent_2005_Entity (Entity (Nam), Nam);
2499 -- Another warning or some utility: if the new subprogram as the same
2500 -- name as the old one, the old one is not hidden by an outer homograph,
2501 -- the new one is not a public symbol, and the old one is otherwise
2502 -- directly visible, the renaming is superfluous.
2504 if Chars (Old_S) = Chars (New_S)
2505 and then Comes_From_Source (N)
2506 and then Scope (Old_S) /= Standard_Standard
2507 and then Warn_On_Redundant_Constructs
2509 (Is_Immediately_Visible (Old_S)
2510 or else Is_Potentially_Use_Visible (Old_S))
2511 and then Is_Overloadable (Current_Scope)
2512 and then Chars (Current_Scope) /= Chars (Old_S)
2515 ("?redundant renaming, entity is directly visible", Name (N));
2518 Ada_Version := Save_AV;
2519 Ada_Version_Explicit := Save_AV_Exp;
2520 end Analyze_Subprogram_Renaming;
2522 -------------------------
2523 -- Analyze_Use_Package --
2524 -------------------------
2526 -- Resolve the package names in the use clause, and make all the visible
2527 -- entities defined in the package potentially use-visible. If the package
2528 -- is already in use from a previous use clause, its visible entities are
2529 -- already use-visible. In that case, mark the occurrence as a redundant
2530 -- use. If the package is an open scope, i.e. if the use clause occurs
2531 -- within the package itself, ignore it.
2533 procedure Analyze_Use_Package (N : Node_Id) is
2534 Pack_Name : Node_Id;
2537 -- Start of processing for Analyze_Use_Package
2540 Set_Hidden_By_Use_Clause (N, No_Elist);
2542 -- Use clause is not allowed in a spec of a predefined package
2543 -- declaration except that packages whose file name starts a-n are OK
2544 -- (these are children of Ada.Numerics, and such packages are never
2545 -- loaded by Rtsfind).
2547 if Is_Predefined_File_Name (Unit_File_Name (Current_Sem_Unit))
2548 and then Name_Buffer (1 .. 3) /= "a-n"
2550 Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Declaration
2552 Error_Msg_N ("use clause not allowed in predefined spec", N);
2555 -- Chain clause to list of use clauses in current scope
2557 if Nkind (Parent (N)) /= N_Compilation_Unit then
2558 Chain_Use_Clause (N);
2561 -- Loop through package names to identify referenced packages
2563 Pack_Name := First (Names (N));
2564 while Present (Pack_Name) loop
2565 Analyze (Pack_Name);
2567 if Nkind (Parent (N)) = N_Compilation_Unit
2568 and then Nkind (Pack_Name) = N_Expanded_Name
2574 Pref := Prefix (Pack_Name);
2575 while Nkind (Pref) = N_Expanded_Name loop
2576 Pref := Prefix (Pref);
2579 if Entity (Pref) = Standard_Standard then
2581 ("predefined package Standard cannot appear"
2582 & " in a context clause", Pref);
2590 -- Loop through package names to mark all entities as potentially
2593 Pack_Name := First (Names (N));
2594 while Present (Pack_Name) loop
2595 if Is_Entity_Name (Pack_Name) then
2596 Pack := Entity (Pack_Name);
2598 if Ekind (Pack) /= E_Package
2599 and then Etype (Pack) /= Any_Type
2601 if Ekind (Pack) = E_Generic_Package then
2602 Error_Msg_N -- CODEFIX
2603 ("a generic package is not allowed in a use clause",
2606 Error_Msg_N ("& is not a usable package", Pack_Name);
2610 if Nkind (Parent (N)) = N_Compilation_Unit then
2611 Check_In_Previous_With_Clause (N, Pack_Name);
2614 if Applicable_Use (Pack_Name) then
2615 Use_One_Package (Pack, N);
2619 -- Report error because name denotes something other than a package
2622 Error_Msg_N ("& is not a package", Pack_Name);
2627 end Analyze_Use_Package;
2629 ----------------------
2630 -- Analyze_Use_Type --
2631 ----------------------
2633 procedure Analyze_Use_Type (N : Node_Id) is
2638 Set_Hidden_By_Use_Clause (N, No_Elist);
2640 -- Chain clause to list of use clauses in current scope
2642 if Nkind (Parent (N)) /= N_Compilation_Unit then
2643 Chain_Use_Clause (N);
2646 Id := First (Subtype_Marks (N));
2647 while Present (Id) loop
2651 if E /= Any_Type then
2654 if Nkind (Parent (N)) = N_Compilation_Unit then
2655 if Nkind (Id) = N_Identifier then
2656 Error_Msg_N ("type is not directly visible", Id);
2658 elsif Is_Child_Unit (Scope (E))
2659 and then Scope (E) /= System_Aux_Id
2661 Check_In_Previous_With_Clause (N, Prefix (Id));
2666 -- If the use_type_clause appears in a compilation unit context,
2667 -- check whether it comes from a unit that may appear in a
2668 -- limited_with_clause, for a better error message.
2670 if Nkind (Parent (N)) = N_Compilation_Unit
2671 and then Nkind (Id) /= N_Identifier
2677 function Mentioned (Nam : Node_Id) return Boolean;
2678 -- Check whether the prefix of expanded name for the type
2679 -- appears in the prefix of some limited_with_clause.
2685 function Mentioned (Nam : Node_Id) return Boolean is
2687 return Nkind (Name (Item)) = N_Selected_Component
2689 Chars (Prefix (Name (Item))) = Chars (Nam);
2693 Pref := Prefix (Id);
2694 Item := First (Context_Items (Parent (N)));
2696 while Present (Item) and then Item /= N loop
2697 if Nkind (Item) = N_With_Clause
2698 and then Limited_Present (Item)
2699 and then Mentioned (Pref)
2702 (Get_Msg_Id, "premature usage of incomplete type");
2713 end Analyze_Use_Type;
2715 --------------------
2716 -- Applicable_Use --
2717 --------------------
2719 function Applicable_Use (Pack_Name : Node_Id) return Boolean is
2720 Pack : constant Entity_Id := Entity (Pack_Name);
2723 if In_Open_Scopes (Pack) then
2724 if Warn_On_Redundant_Constructs
2725 and then Pack = Current_Scope
2727 Error_Msg_NE -- CODEFIX
2728 ("& is already use-visible within itself?", Pack_Name, Pack);
2733 elsif In_Use (Pack) then
2734 Note_Redundant_Use (Pack_Name);
2737 elsif Present (Renamed_Object (Pack))
2738 and then In_Use (Renamed_Object (Pack))
2740 Note_Redundant_Use (Pack_Name);
2748 ------------------------
2749 -- Attribute_Renaming --
2750 ------------------------
2752 procedure Attribute_Renaming (N : Node_Id) is
2753 Loc : constant Source_Ptr := Sloc (N);
2754 Nam : constant Node_Id := Name (N);
2755 Spec : constant Node_Id := Specification (N);
2756 New_S : constant Entity_Id := Defining_Unit_Name (Spec);
2757 Aname : constant Name_Id := Attribute_Name (Nam);
2759 Form_Num : Nat := 0;
2760 Expr_List : List_Id := No_List;
2762 Attr_Node : Node_Id;
2763 Body_Node : Node_Id;
2764 Param_Spec : Node_Id;
2767 Generate_Definition (New_S);
2769 -- This procedure is called in the context of subprogram renaming, and
2770 -- thus the attribute must be one that is a subprogram. All of those
2771 -- have at least one formal parameter, with the singular exception of
2772 -- AST_Entry (which is a real oddity, it is odd that this can be renamed
2775 if not Is_Non_Empty_List (Parameter_Specifications (Spec)) then
2776 if Aname /= Name_AST_Entry then
2778 ("subprogram renaming an attribute must have formals", N);
2783 Param_Spec := First (Parameter_Specifications (Spec));
2784 while Present (Param_Spec) loop
2785 Form_Num := Form_Num + 1;
2787 if Nkind (Parameter_Type (Param_Spec)) /= N_Access_Definition then
2788 Find_Type (Parameter_Type (Param_Spec));
2790 -- The profile of the new entity denotes the base type (s) of
2791 -- the types given in the specification. For access parameters
2792 -- there are no subtypes involved.
2794 Rewrite (Parameter_Type (Param_Spec),
2796 (Base_Type (Entity (Parameter_Type (Param_Spec))), Loc));
2799 if No (Expr_List) then
2800 Expr_List := New_List;
2803 Append_To (Expr_List,
2804 Make_Identifier (Loc,
2805 Chars => Chars (Defining_Identifier (Param_Spec))));
2807 -- The expressions in the attribute reference are not freeze
2808 -- points. Neither is the attribute as a whole, see below.
2810 Set_Must_Not_Freeze (Last (Expr_List));
2815 -- Immediate error if too many formals. Other mismatches in number or
2816 -- types of parameters are detected when we analyze the body of the
2817 -- subprogram that we construct.
2819 if Form_Num > 2 then
2820 Error_Msg_N ("too many formals for attribute", N);
2822 -- Error if the attribute reference has expressions that look like
2823 -- formal parameters.
2825 elsif Present (Expressions (Nam)) then
2826 Error_Msg_N ("illegal expressions in attribute reference", Nam);
2829 Aname = Name_Compose or else
2830 Aname = Name_Exponent or else
2831 Aname = Name_Leading_Part or else
2832 Aname = Name_Pos or else
2833 Aname = Name_Round or else
2834 Aname = Name_Scaling or else
2837 if Nkind (N) = N_Subprogram_Renaming_Declaration
2838 and then Present (Corresponding_Formal_Spec (N))
2841 ("generic actual cannot be attribute involving universal type",
2845 ("attribute involving a universal type cannot be renamed",
2850 -- AST_Entry is an odd case. It doesn't really make much sense to allow
2851 -- it to be renamed, but that's the DEC rule, so we have to do it right.
2852 -- The point is that the AST_Entry call should be made now, and what the
2853 -- function will return is the returned value.
2855 -- Note that there is no Expr_List in this case anyway
2857 if Aname = Name_AST_Entry then
2859 Ent : constant Entity_Id := Make_Temporary (Loc, 'R', Nam);
2864 Make_Object_Declaration (Loc,
2865 Defining_Identifier => Ent,
2866 Object_Definition =>
2867 New_Occurrence_Of (RTE (RE_AST_Handler), Loc),
2869 Constant_Present => True);
2871 Set_Assignment_OK (Decl, True);
2872 Insert_Action (N, Decl);
2873 Attr_Node := Make_Identifier (Loc, Chars (Ent));
2876 -- For all other attributes, we rewrite the attribute node to have
2877 -- a list of expressions corresponding to the subprogram formals.
2878 -- A renaming declaration is not a freeze point, and the analysis of
2879 -- the attribute reference should not freeze the type of the prefix.
2883 Make_Attribute_Reference (Loc,
2884 Prefix => Prefix (Nam),
2885 Attribute_Name => Aname,
2886 Expressions => Expr_List);
2888 Set_Must_Not_Freeze (Attr_Node);
2889 Set_Must_Not_Freeze (Prefix (Nam));
2892 -- Case of renaming a function
2894 if Nkind (Spec) = N_Function_Specification then
2895 if Is_Procedure_Attribute_Name (Aname) then
2896 Error_Msg_N ("attribute can only be renamed as procedure", Nam);
2900 Find_Type (Result_Definition (Spec));
2901 Rewrite (Result_Definition (Spec),
2903 Base_Type (Entity (Result_Definition (Spec))), Loc));
2906 Make_Subprogram_Body (Loc,
2907 Specification => Spec,
2908 Declarations => New_List,
2909 Handled_Statement_Sequence =>
2910 Make_Handled_Sequence_Of_Statements (Loc,
2911 Statements => New_List (
2912 Make_Simple_Return_Statement (Loc,
2913 Expression => Attr_Node))));
2915 -- Case of renaming a procedure
2918 if not Is_Procedure_Attribute_Name (Aname) then
2919 Error_Msg_N ("attribute can only be renamed as function", Nam);
2924 Make_Subprogram_Body (Loc,
2925 Specification => Spec,
2926 Declarations => New_List,
2927 Handled_Statement_Sequence =>
2928 Make_Handled_Sequence_Of_Statements (Loc,
2929 Statements => New_List (Attr_Node)));
2932 -- In case of tagged types we add the body of the generated function to
2933 -- the freezing actions of the type (because in the general case such
2934 -- type is still not frozen). We exclude from this processing generic
2935 -- formal subprograms found in instantiations and AST_Entry renamings.
2937 -- We must exclude VM targets because entity AST_Handler is defined in
2938 -- package System.Aux_Dec which is not available in those platforms.
2940 if VM_Target = No_VM
2941 and then not Present (Corresponding_Formal_Spec (N))
2942 and then Etype (Nam) /= RTE (RE_AST_Handler)
2945 P : constant Entity_Id := Prefix (Nam);
2950 if Is_Tagged_Type (Etype (P)) then
2951 Ensure_Freeze_Node (Etype (P));
2952 Append_Freeze_Action (Etype (P), Body_Node);
2954 Rewrite (N, Body_Node);
2956 Set_Etype (New_S, Base_Type (Etype (New_S)));
2960 -- Generic formal subprograms or AST_Handler renaming
2963 Rewrite (N, Body_Node);
2965 Set_Etype (New_S, Base_Type (Etype (New_S)));
2968 if Is_Compilation_Unit (New_S) then
2970 ("a library unit can only rename another library unit", N);
2973 -- We suppress elaboration warnings for the resulting entity, since
2974 -- clearly they are not needed, and more particularly, in the case
2975 -- of a generic formal subprogram, the resulting entity can appear
2976 -- after the instantiation itself, and thus look like a bogus case
2977 -- of access before elaboration.
2979 Set_Suppress_Elaboration_Warnings (New_S);
2981 end Attribute_Renaming;
2983 ----------------------
2984 -- Chain_Use_Clause --
2985 ----------------------
2987 procedure Chain_Use_Clause (N : Node_Id) is
2989 Level : Int := Scope_Stack.Last;
2992 if not Is_Compilation_Unit (Current_Scope)
2993 or else not Is_Child_Unit (Current_Scope)
2995 null; -- Common case
2997 elsif Defining_Entity (Parent (N)) = Current_Scope then
2998 null; -- Common case for compilation unit
3001 -- If declaration appears in some other scope, it must be in some
3002 -- parent unit when compiling a child.
3004 Pack := Defining_Entity (Parent (N));
3005 if not In_Open_Scopes (Pack) then
3006 null; -- default as well
3009 -- Find entry for parent unit in scope stack
3011 while Scope_Stack.Table (Level).Entity /= Pack loop
3017 Set_Next_Use_Clause (N,
3018 Scope_Stack.Table (Level).First_Use_Clause);
3019 Scope_Stack.Table (Level).First_Use_Clause := N;
3020 end Chain_Use_Clause;
3022 ---------------------------
3023 -- Check_Frozen_Renaming --
3024 ---------------------------
3026 procedure Check_Frozen_Renaming (N : Node_Id; Subp : Entity_Id) is
3032 and then not Has_Completion (Subp)
3036 (Parent (Declaration_Node (Subp)), Defining_Entity (N));
3038 if Is_Entity_Name (Name (N)) then
3039 Old_S := Entity (Name (N));
3041 if not Is_Frozen (Old_S)
3042 and then Operating_Mode /= Check_Semantics
3044 Append_Freeze_Action (Old_S, B_Node);
3046 Insert_After (N, B_Node);
3050 if Is_Intrinsic_Subprogram (Old_S)
3051 and then not In_Instance
3054 ("subprogram used in renaming_as_body cannot be intrinsic",
3059 Insert_After (N, B_Node);
3063 end Check_Frozen_Renaming;
3065 -------------------------------
3066 -- Set_Entity_Or_Discriminal --
3067 -------------------------------
3069 procedure Set_Entity_Or_Discriminal (N : Node_Id; E : Entity_Id) is
3073 -- If the entity is not a discriminant, or else expansion is disabled,
3074 -- simply set the entity.
3076 if not In_Spec_Expression
3077 or else Ekind (E) /= E_Discriminant
3078 or else Inside_A_Generic
3080 Set_Entity_With_Style_Check (N, E);
3082 -- The replacement of a discriminant by the corresponding discriminal
3083 -- is not done for a task discriminant that appears in a default
3084 -- expression of an entry parameter. See Exp_Ch2.Expand_Discriminant
3085 -- for details on their handling.
3087 elsif Is_Concurrent_Type (Scope (E)) then
3091 and then not Nkind_In (P, N_Parameter_Specification,
3092 N_Component_Declaration)
3098 and then Nkind (P) = N_Parameter_Specification
3103 Set_Entity (N, Discriminal (E));
3106 -- Otherwise, this is a discriminant in a context in which
3107 -- it is a reference to the corresponding parameter of the
3108 -- init proc for the enclosing type.
3111 Set_Entity (N, Discriminal (E));
3113 end Set_Entity_Or_Discriminal;
3115 -----------------------------------
3116 -- Check_In_Previous_With_Clause --
3117 -----------------------------------
3119 procedure Check_In_Previous_With_Clause
3123 Pack : constant Entity_Id := Entity (Original_Node (Nam));
3128 Item := First (Context_Items (Parent (N)));
3130 while Present (Item)
3133 if Nkind (Item) = N_With_Clause
3135 -- Protect the frontend against previous critical errors
3137 and then Nkind (Name (Item)) /= N_Selected_Component
3138 and then Entity (Name (Item)) = Pack
3142 -- Find root library unit in with_clause
3144 while Nkind (Par) = N_Expanded_Name loop
3145 Par := Prefix (Par);
3148 if Is_Child_Unit (Entity (Original_Node (Par))) then
3149 Error_Msg_NE ("& is not directly visible", Par, Entity (Par));
3158 -- On exit, package is not mentioned in a previous with_clause.
3159 -- Check if its prefix is.
3161 if Nkind (Nam) = N_Expanded_Name then
3162 Check_In_Previous_With_Clause (N, Prefix (Nam));
3164 elsif Pack /= Any_Id then
3165 Error_Msg_NE ("& is not visible", Nam, Pack);
3167 end Check_In_Previous_With_Clause;
3169 ---------------------------------
3170 -- Check_Library_Unit_Renaming --
3171 ---------------------------------
3173 procedure Check_Library_Unit_Renaming (N : Node_Id; Old_E : Entity_Id) is
3177 if Nkind (Parent (N)) /= N_Compilation_Unit then
3180 -- Check for library unit. Note that we used to check for the scope
3181 -- being Standard here, but that was wrong for Standard itself.
3183 elsif not Is_Compilation_Unit (Old_E)
3184 and then not Is_Child_Unit (Old_E)
3186 Error_Msg_N ("renamed unit must be a library unit", Name (N));
3188 -- Entities defined in Standard (operators and boolean literals) cannot
3189 -- be renamed as library units.
3191 elsif Scope (Old_E) = Standard_Standard
3192 and then Sloc (Old_E) = Standard_Location
3194 Error_Msg_N ("renamed unit must be a library unit", Name (N));
3196 elsif Present (Parent_Spec (N))
3197 and then Nkind (Unit (Parent_Spec (N))) = N_Generic_Package_Declaration
3198 and then not Is_Child_Unit (Old_E)
3201 ("renamed unit must be a child unit of generic parent", Name (N));
3203 elsif Nkind (N) in N_Generic_Renaming_Declaration
3204 and then Nkind (Name (N)) = N_Expanded_Name
3205 and then Is_Generic_Instance (Entity (Prefix (Name (N))))
3206 and then Is_Generic_Unit (Old_E)
3209 ("renamed generic unit must be a library unit", Name (N));
3211 elsif Is_Package_Or_Generic_Package (Old_E) then
3213 -- Inherit categorization flags
3215 New_E := Defining_Entity (N);
3216 Set_Is_Pure (New_E, Is_Pure (Old_E));
3217 Set_Is_Preelaborated (New_E, Is_Preelaborated (Old_E));
3218 Set_Is_Remote_Call_Interface (New_E,
3219 Is_Remote_Call_Interface (Old_E));
3220 Set_Is_Remote_Types (New_E, Is_Remote_Types (Old_E));
3221 Set_Is_Shared_Passive (New_E, Is_Shared_Passive (Old_E));
3223 end Check_Library_Unit_Renaming;
3229 procedure End_Scope is
3235 Id := First_Entity (Current_Scope);
3236 while Present (Id) loop
3237 -- An entity in the current scope is not necessarily the first one
3238 -- on its homonym chain. Find its predecessor if any,
3239 -- If it is an internal entity, it will not be in the visibility
3240 -- chain altogether, and there is nothing to unchain.
3242 if Id /= Current_Entity (Id) then
3243 Prev := Current_Entity (Id);
3244 while Present (Prev)
3245 and then Present (Homonym (Prev))
3246 and then Homonym (Prev) /= Id
3248 Prev := Homonym (Prev);
3251 -- Skip to end of loop if Id is not in the visibility chain
3253 if No (Prev) or else Homonym (Prev) /= Id then
3261 Set_Is_Immediately_Visible (Id, False);
3263 Outer := Homonym (Id);
3264 while Present (Outer) and then Scope (Outer) = Current_Scope loop
3265 Outer := Homonym (Outer);
3268 -- Reset homonym link of other entities, but do not modify link
3269 -- between entities in current scope, so that the back-end can have
3270 -- a proper count of local overloadings.
3273 Set_Name_Entity_Id (Chars (Id), Outer);
3275 elsif Scope (Prev) /= Scope (Id) then
3276 Set_Homonym (Prev, Outer);
3283 -- If the scope generated freeze actions, place them before the
3284 -- current declaration and analyze them. Type declarations and
3285 -- the bodies of initialization procedures can generate such nodes.
3286 -- We follow the parent chain until we reach a list node, which is
3287 -- the enclosing list of declarations. If the list appears within
3288 -- a protected definition, move freeze nodes outside the protected
3292 (Scope_Stack.Table (Scope_Stack.Last).Pending_Freeze_Actions)
3296 L : constant List_Id := Scope_Stack.Table
3297 (Scope_Stack.Last).Pending_Freeze_Actions;
3300 if Is_Itype (Current_Scope) then
3301 Decl := Associated_Node_For_Itype (Current_Scope);
3303 Decl := Parent (Current_Scope);
3308 while not (Is_List_Member (Decl))
3309 or else Nkind_In (Parent (Decl), N_Protected_Definition,
3312 Decl := Parent (Decl);
3315 Insert_List_Before_And_Analyze (Decl, L);
3324 ---------------------
3325 -- End_Use_Clauses --
3326 ---------------------
3328 procedure End_Use_Clauses (Clause : Node_Id) is
3332 -- Remove Use_Type clauses first, because they affect the
3333 -- visibility of operators in subsequent used packages.
3336 while Present (U) loop
3337 if Nkind (U) = N_Use_Type_Clause then
3341 Next_Use_Clause (U);
3345 while Present (U) loop
3346 if Nkind (U) = N_Use_Package_Clause then
3347 End_Use_Package (U);
3350 Next_Use_Clause (U);
3352 end End_Use_Clauses;
3354 ---------------------
3355 -- End_Use_Package --
3356 ---------------------
3358 procedure End_Use_Package (N : Node_Id) is
3359 Pack_Name : Node_Id;
3364 function Is_Primitive_Operator_In_Use
3366 F : Entity_Id) return Boolean;
3367 -- Check whether Op is a primitive operator of a use-visible type
3369 ----------------------------------
3370 -- Is_Primitive_Operator_In_Use --
3371 ----------------------------------
3373 function Is_Primitive_Operator_In_Use
3375 F : Entity_Id) return Boolean
3377 T : constant Entity_Id := Etype (F);
3380 or else Present (Current_Use_Clause (Base_Type (T))))
3381 and then Scope (T) = Scope (Op);
3382 end Is_Primitive_Operator_In_Use;
3384 -- Start of processing for End_Use_Package
3387 Pack_Name := First (Names (N));
3388 while Present (Pack_Name) loop
3390 -- Test that Pack_Name actually denotes a package before processing
3392 if Is_Entity_Name (Pack_Name)
3393 and then Ekind (Entity (Pack_Name)) = E_Package
3395 Pack := Entity (Pack_Name);
3397 if In_Open_Scopes (Pack) then
3400 elsif not Redundant_Use (Pack_Name) then
3401 Set_In_Use (Pack, False);
3402 Set_Current_Use_Clause (Pack, Empty);
3404 Id := First_Entity (Pack);
3405 while Present (Id) loop
3407 -- Preserve use-visibility of operators that are primitive
3408 -- operators of a type that is use-visible through an active
3411 if Nkind (Id) = N_Defining_Operator_Symbol
3413 (Is_Primitive_Operator_In_Use
3414 (Id, First_Formal (Id))
3416 (Present (Next_Formal (First_Formal (Id)))
3418 Is_Primitive_Operator_In_Use
3419 (Id, Next_Formal (First_Formal (Id)))))
3424 Set_Is_Potentially_Use_Visible (Id, False);
3427 if Is_Private_Type (Id)
3428 and then Present (Full_View (Id))
3430 Set_Is_Potentially_Use_Visible (Full_View (Id), False);
3436 if Present (Renamed_Object (Pack)) then
3437 Set_In_Use (Renamed_Object (Pack), False);
3438 Set_Current_Use_Clause (Renamed_Object (Pack), Empty);
3441 if Chars (Pack) = Name_System
3442 and then Scope (Pack) = Standard_Standard
3443 and then Present_System_Aux
3445 Id := First_Entity (System_Aux_Id);
3446 while Present (Id) loop
3447 Set_Is_Potentially_Use_Visible (Id, False);
3449 if Is_Private_Type (Id)
3450 and then Present (Full_View (Id))
3452 Set_Is_Potentially_Use_Visible (Full_View (Id), False);
3458 Set_In_Use (System_Aux_Id, False);
3462 Set_Redundant_Use (Pack_Name, False);
3469 if Present (Hidden_By_Use_Clause (N)) then
3470 Elmt := First_Elmt (Hidden_By_Use_Clause (N));
3471 while Present (Elmt) loop
3473 E : constant Entity_Id := Node (Elmt);
3476 -- Reset either Use_Visibility or Direct_Visibility, depending
3477 -- on how the entity was hidden by the use clause.
3479 if In_Use (Scope (E))
3480 and then Used_As_Generic_Actual (Scope (E))
3482 Set_Is_Potentially_Use_Visible (Node (Elmt));
3484 Set_Is_Immediately_Visible (Node (Elmt));
3491 Set_Hidden_By_Use_Clause (N, No_Elist);
3493 end End_Use_Package;
3499 procedure End_Use_Type (N : Node_Id) is
3506 function May_Be_Used_Primitive_Of (T : Entity_Id) return Boolean;
3507 -- An operator may be primitive in several types, if they are declared
3508 -- in the same scope as the operator. To determine the use-visiblity of
3509 -- the operator in such cases we must examine all types in the profile.
3511 ------------------------------
3512 -- May_Be_Used_Primitive_Of --
3513 ------------------------------
3515 function May_Be_Used_Primitive_Of (T : Entity_Id) return Boolean is
3517 return Scope (Op) = Scope (T)
3518 and then (In_Use (T) or else Is_Potentially_Use_Visible (T));
3519 end May_Be_Used_Primitive_Of;
3521 -- Start of processing for End_Use_Type
3524 Id := First (Subtype_Marks (N));
3525 while Present (Id) loop
3527 -- A call to Rtsfind may occur while analyzing a use_type clause,
3528 -- in which case the type marks are not resolved yet, and there is
3529 -- nothing to remove.
3531 if not Is_Entity_Name (Id) or else No (Entity (Id)) then
3537 if T = Any_Type or else From_With_Type (T) then
3540 -- Note that the use_type clause may mention a subtype of the type
3541 -- whose primitive operations have been made visible. Here as
3542 -- elsewhere, it is the base type that matters for visibility.
3544 elsif In_Open_Scopes (Scope (Base_Type (T))) then
3547 elsif not Redundant_Use (Id) then
3548 Set_In_Use (T, False);
3549 Set_In_Use (Base_Type (T), False);
3550 Set_Current_Use_Clause (T, Empty);
3551 Set_Current_Use_Clause (Base_Type (T), Empty);
3552 Op_List := Collect_Primitive_Operations (T);
3554 Elmt := First_Elmt (Op_List);
3555 while Present (Elmt) loop
3558 if Nkind (Op) = N_Defining_Operator_Symbol then
3560 T_First : constant Entity_Id :=
3561 Base_Type (Etype (First_Formal (Op)));
3562 T_Res : constant Entity_Id := Base_Type (Etype (Op));
3566 if Present (Next_Formal (First_Formal (Op))) then
3568 Base_Type (Etype (Next_Formal (First_Formal (Op))));
3573 if not May_Be_Used_Primitive_Of (T_First)
3574 and then not May_Be_Used_Primitive_Of (T_Next)
3575 and then not May_Be_Used_Primitive_Of (T_Res)
3577 Set_Is_Potentially_Use_Visible (Op, False);
3591 ----------------------
3592 -- Find_Direct_Name --
3593 ----------------------
3595 procedure Find_Direct_Name (N : Node_Id) is
3600 Inst : Entity_Id := Empty;
3601 -- Enclosing instance, if any
3603 Homonyms : Entity_Id;
3604 -- Saves start of homonym chain
3606 Nvis_Entity : Boolean;
3607 -- Set True to indicate that there is at least one entity on the homonym
3608 -- chain which, while not visible, is visible enough from the user point
3609 -- of view to warrant an error message of "not visible" rather than
3612 Nvis_Is_Private_Subprg : Boolean := False;
3613 -- Ada 2005 (AI-262): Set True to indicate that a form of Beaujolais
3614 -- effect concerning library subprograms has been detected. Used to
3615 -- generate the precise error message.
3617 function From_Actual_Package (E : Entity_Id) return Boolean;
3618 -- Returns true if the entity is declared in a package that is
3619 -- an actual for a formal package of the current instance. Such an
3620 -- entity requires special handling because it may be use-visible
3621 -- but hides directly visible entities defined outside the instance.
3623 function Is_Actual_Parameter return Boolean;
3624 -- This function checks if the node N is an identifier that is an actual
3625 -- parameter of a procedure call. If so it returns True, otherwise it
3626 -- return False. The reason for this check is that at this stage we do
3627 -- not know what procedure is being called if the procedure might be
3628 -- overloaded, so it is premature to go setting referenced flags or
3629 -- making calls to Generate_Reference. We will wait till Resolve_Actuals
3630 -- for that processing
3632 function Known_But_Invisible (E : Entity_Id) return Boolean;
3633 -- This function determines whether the entity E (which is not
3634 -- visible) can reasonably be considered to be known to the writer
3635 -- of the reference. This is a heuristic test, used only for the
3636 -- purposes of figuring out whether we prefer to complain that an
3637 -- entity is undefined or invisible (and identify the declaration
3638 -- of the invisible entity in the latter case). The point here is
3639 -- that we don't want to complain that something is invisible and
3640 -- then point to something entirely mysterious to the writer.
3642 procedure Nvis_Messages;
3643 -- Called if there are no visible entries for N, but there is at least
3644 -- one non-directly visible, or hidden declaration. This procedure
3645 -- outputs an appropriate set of error messages.
3647 procedure Undefined (Nvis : Boolean);
3648 -- This function is called if the current node has no corresponding
3649 -- visible entity or entities. The value set in Msg indicates whether
3650 -- an error message was generated (multiple error messages for the
3651 -- same variable are generally suppressed, see body for details).
3652 -- Msg is True if an error message was generated, False if not. This
3653 -- value is used by the caller to determine whether or not to output
3654 -- additional messages where appropriate. The parameter is set False
3655 -- to get the message "X is undefined", and True to get the message
3656 -- "X is not visible".
3658 -------------------------
3659 -- From_Actual_Package --
3660 -------------------------
3662 function From_Actual_Package (E : Entity_Id) return Boolean is
3663 Scop : constant Entity_Id := Scope (E);
3667 if not In_Instance then
3670 Inst := Current_Scope;
3671 while Present (Inst)
3672 and then Ekind (Inst) /= E_Package
3673 and then not Is_Generic_Instance (Inst)
3675 Inst := Scope (Inst);
3682 Act := First_Entity (Inst);
3683 while Present (Act) loop
3684 if Ekind (Act) = E_Package then
3686 -- Check for end of actuals list
3688 if Renamed_Object (Act) = Inst then
3691 elsif Present (Associated_Formal_Package (Act))
3692 and then Renamed_Object (Act) = Scop
3694 -- Entity comes from (instance of) formal package
3709 end From_Actual_Package;
3711 -------------------------
3712 -- Is_Actual_Parameter --
3713 -------------------------
3715 function Is_Actual_Parameter return Boolean is
3718 Nkind (N) = N_Identifier
3720 (Nkind (Parent (N)) = N_Procedure_Call_Statement
3722 (Nkind (Parent (N)) = N_Parameter_Association
3723 and then N = Explicit_Actual_Parameter (Parent (N))
3724 and then Nkind (Parent (Parent (N))) =
3725 N_Procedure_Call_Statement));
3726 end Is_Actual_Parameter;
3728 -------------------------
3729 -- Known_But_Invisible --
3730 -------------------------
3732 function Known_But_Invisible (E : Entity_Id) return Boolean is
3733 Fname : File_Name_Type;
3736 -- Entities in Standard are always considered to be known
3738 if Sloc (E) <= Standard_Location then
3741 -- An entity that does not come from source is always considered
3742 -- to be unknown, since it is an artifact of code expansion.
3744 elsif not Comes_From_Source (E) then
3747 -- In gnat internal mode, we consider all entities known
3749 elsif GNAT_Mode then
3753 -- Here we have an entity that is not from package Standard, and
3754 -- which comes from Source. See if it comes from an internal file.
3756 Fname := Unit_File_Name (Get_Source_Unit (E));
3758 -- Case of from internal file
3760 if Is_Internal_File_Name (Fname) then
3762 -- Private part entities in internal files are never considered
3763 -- to be known to the writer of normal application code.
3765 if Is_Hidden (E) then
3769 -- Entities from System packages other than System and
3770 -- System.Storage_Elements are not considered to be known.
3771 -- System.Auxxxx files are also considered known to the user.
3773 -- Should refine this at some point to generally distinguish
3774 -- between known and unknown internal files ???
3776 Get_Name_String (Fname);
3781 Name_Buffer (1 .. 2) /= "s-"
3783 Name_Buffer (3 .. 8) = "stoele"
3785 Name_Buffer (3 .. 5) = "aux";
3787 -- If not an internal file, then entity is definitely known,
3788 -- even if it is in a private part (the message generated will
3789 -- note that it is in a private part)
3794 end Known_But_Invisible;
3800 procedure Nvis_Messages is
3801 Comp_Unit : Node_Id;
3803 Found : Boolean := False;
3804 Hidden : Boolean := False;
3808 -- Ada 2005 (AI-262): Generate a precise error concerning the
3809 -- Beaujolais effect that was previously detected
3811 if Nvis_Is_Private_Subprg then
3813 pragma Assert (Nkind (E2) = N_Defining_Identifier
3814 and then Ekind (E2) = E_Function
3815 and then Scope (E2) = Standard_Standard
3816 and then Has_Private_With (E2));
3818 -- Find the sloc corresponding to the private with'ed unit
3820 Comp_Unit := Cunit (Current_Sem_Unit);
3821 Error_Msg_Sloc := No_Location;
3823 Item := First (Context_Items (Comp_Unit));
3824 while Present (Item) loop
3825 if Nkind (Item) = N_With_Clause
3826 and then Private_Present (Item)
3827 and then Entity (Name (Item)) = E2
3829 Error_Msg_Sloc := Sloc (Item);
3836 pragma Assert (Error_Msg_Sloc /= No_Location);
3838 Error_Msg_N ("(Ada 2005): hidden by private with clause #", N);
3842 Undefined (Nvis => True);
3846 -- First loop does hidden declarations
3849 while Present (Ent) loop
3850 if Is_Potentially_Use_Visible (Ent) then
3852 Error_Msg_N -- CODEFIX
3853 ("multiple use clauses cause hiding!", N);
3857 Error_Msg_Sloc := Sloc (Ent);
3858 Error_Msg_N -- CODEFIX
3859 ("hidden declaration#!", N);
3862 Ent := Homonym (Ent);
3865 -- If we found hidden declarations, then that's enough, don't
3866 -- bother looking for non-visible declarations as well.
3872 -- Second loop does non-directly visible declarations
3875 while Present (Ent) loop
3876 if not Is_Potentially_Use_Visible (Ent) then
3878 -- Do not bother the user with unknown entities
3880 if not Known_But_Invisible (Ent) then
3884 Error_Msg_Sloc := Sloc (Ent);
3886 -- Output message noting that there is a non-visible
3887 -- declaration, distinguishing the private part case.
3889 if Is_Hidden (Ent) then
3890 Error_Msg_N ("non-visible (private) declaration#!", N);
3892 -- If the entity is declared in a generic package, it
3893 -- cannot be visible, so there is no point in adding it
3894 -- to the list of candidates if another homograph from a
3895 -- non-generic package has been seen.
3897 elsif Ekind (Scope (Ent)) = E_Generic_Package
3903 Error_Msg_N -- CODEFIX
3904 ("non-visible declaration#!", N);
3906 if Ekind (Scope (Ent)) /= E_Generic_Package then
3910 if Is_Compilation_Unit (Ent)
3912 Nkind (Parent (Parent (N))) = N_Use_Package_Clause
3914 Error_Msg_Qual_Level := 99;
3915 Error_Msg_NE -- CODEFIX
3916 ("\\missing `WITH &;`", N, Ent);
3917 Error_Msg_Qual_Level := 0;
3920 if Ekind (Ent) = E_Discriminant
3921 and then Present (Corresponding_Discriminant (Ent))
3922 and then Scope (Corresponding_Discriminant (Ent)) =
3926 ("inherited discriminant not allowed here" &
3927 " (RM 3.8 (12), 3.8.1 (6))!", N);
3931 -- Set entity and its containing package as referenced. We
3932 -- can't be sure of this, but this seems a better choice
3933 -- to avoid unused entity messages.
3935 if Comes_From_Source (Ent) then
3936 Set_Referenced (Ent);
3937 Set_Referenced (Cunit_Entity (Get_Source_Unit (Ent)));
3942 Ent := Homonym (Ent);
3951 procedure Undefined (Nvis : Boolean) is
3952 Emsg : Error_Msg_Id;
3955 -- We should never find an undefined internal name. If we do, then
3956 -- see if we have previous errors. If so, ignore on the grounds that
3957 -- it is probably a cascaded message (e.g. a block label from a badly
3958 -- formed block). If no previous errors, then we have a real internal
3959 -- error of some kind so raise an exception.
3961 if Is_Internal_Name (Chars (N)) then
3962 if Total_Errors_Detected /= 0 then
3965 raise Program_Error;
3969 -- A very specialized error check, if the undefined variable is
3970 -- a case tag, and the case type is an enumeration type, check
3971 -- for a possible misspelling, and if so, modify the identifier
3973 -- Named aggregate should also be handled similarly ???
3975 if Nkind (N) = N_Identifier
3976 and then Nkind (Parent (N)) = N_Case_Statement_Alternative
3979 Case_Stm : constant Node_Id := Parent (Parent (N));
3980 Case_Typ : constant Entity_Id := Etype (Expression (Case_Stm));
3985 if Is_Enumeration_Type (Case_Typ)
3986 and then not Is_Standard_Character_Type (Case_Typ)
3988 Lit := First_Literal (Case_Typ);
3989 Get_Name_String (Chars (Lit));
3991 if Chars (Lit) /= Chars (N)
3992 and then Is_Bad_Spelling_Of (Chars (N), Chars (Lit)) then
3993 Error_Msg_Node_2 := Lit;
3994 Error_Msg_N -- CODEFIX
3995 ("& is undefined, assume misspelling of &", N);
3996 Rewrite (N, New_Occurrence_Of (Lit, Sloc (N)));
4000 Lit := Next_Literal (Lit);
4005 -- Normal processing
4007 Set_Entity (N, Any_Id);
4008 Set_Etype (N, Any_Type);
4010 -- We use the table Urefs to keep track of entities for which we
4011 -- have issued errors for undefined references. Multiple errors
4012 -- for a single name are normally suppressed, however we modify
4013 -- the error message to alert the programmer to this effect.
4015 for J in Urefs.First .. Urefs.Last loop
4016 if Chars (N) = Chars (Urefs.Table (J).Node) then
4017 if Urefs.Table (J).Err /= No_Error_Msg
4018 and then Sloc (N) /= Urefs.Table (J).Loc
4020 Error_Msg_Node_1 := Urefs.Table (J).Node;
4022 if Urefs.Table (J).Nvis then
4023 Change_Error_Text (Urefs.Table (J).Err,
4024 "& is not visible (more references follow)");
4026 Change_Error_Text (Urefs.Table (J).Err,
4027 "& is undefined (more references follow)");
4030 Urefs.Table (J).Err := No_Error_Msg;
4033 -- Although we will set Msg False, and thus suppress the
4034 -- message, we also set Error_Posted True, to avoid any
4035 -- cascaded messages resulting from the undefined reference.
4038 Set_Error_Posted (N, True);
4043 -- If entry not found, this is first undefined occurrence
4046 Error_Msg_N ("& is not visible!", N);
4050 Error_Msg_N ("& is undefined!", N);
4053 -- A very bizarre special check, if the undefined identifier
4054 -- is put or put_line, then add a special error message (since
4055 -- this is a very common error for beginners to make).
4057 if Chars (N) = Name_Put or else Chars (N) = Name_Put_Line then
4058 Error_Msg_N -- CODEFIX
4059 ("\\possible missing `WITH Ada.Text_'I'O; " &
4060 "USE Ada.Text_'I'O`!", N);
4062 -- Another special check if N is the prefix of a selected
4063 -- component which is a known unit, add message complaining
4064 -- about missing with for this unit.
4066 elsif Nkind (Parent (N)) = N_Selected_Component
4067 and then N = Prefix (Parent (N))
4068 and then Is_Known_Unit (Parent (N))
4070 Error_Msg_Node_2 := Selector_Name (Parent (N));
4071 Error_Msg_N -- CODEFIX
4072 ("\\missing `WITH &.&;`", Prefix (Parent (N)));
4075 -- Now check for possible misspellings
4079 Ematch : Entity_Id := Empty;
4081 Last_Name_Id : constant Name_Id :=
4082 Name_Id (Nat (First_Name_Id) +
4083 Name_Entries_Count - 1);
4086 for Nam in First_Name_Id .. Last_Name_Id loop
4087 E := Get_Name_Entity_Id (Nam);
4090 and then (Is_Immediately_Visible (E)
4092 Is_Potentially_Use_Visible (E))
4094 if Is_Bad_Spelling_Of (Chars (N), Nam) then
4101 if Present (Ematch) then
4102 Error_Msg_NE -- CODEFIX
4103 ("\possible misspelling of&", N, Ematch);
4108 -- Make entry in undefined references table unless the full errors
4109 -- switch is set, in which case by refraining from generating the
4110 -- table entry, we guarantee that we get an error message for every
4111 -- undefined reference.
4113 if not All_Errors_Mode then
4124 -- Start of processing for Find_Direct_Name
4127 -- If the entity pointer is already set, this is an internal node, or
4128 -- a node that is analyzed more than once, after a tree modification.
4129 -- In such a case there is no resolution to perform, just set the type.
4131 if Present (Entity (N)) then
4132 if Is_Type (Entity (N)) then
4133 Set_Etype (N, Entity (N));
4137 Entyp : constant Entity_Id := Etype (Entity (N));
4140 -- One special case here. If the Etype field is already set,
4141 -- and references the packed array type corresponding to the
4142 -- etype of the referenced entity, then leave it alone. This
4143 -- happens for trees generated from Exp_Pakd, where expressions
4144 -- can be deliberately "mis-typed" to the packed array type.
4146 if Is_Array_Type (Entyp)
4147 and then Is_Packed (Entyp)
4148 and then Present (Etype (N))
4149 and then Etype (N) = Packed_Array_Type (Entyp)
4153 -- If not that special case, then just reset the Etype
4156 Set_Etype (N, Etype (Entity (N)));
4164 -- Here if Entity pointer was not set, we need full visibility analysis
4165 -- First we generate debugging output if the debug E flag is set.
4167 if Debug_Flag_E then
4168 Write_Str ("Looking for ");
4169 Write_Name (Chars (N));
4173 Homonyms := Current_Entity (N);
4174 Nvis_Entity := False;
4177 while Present (E) loop
4179 -- If entity is immediately visible or potentially use visible, then
4180 -- process the entity and we are done.
4182 if Is_Immediately_Visible (E) then
4183 goto Immediately_Visible_Entity;
4185 elsif Is_Potentially_Use_Visible (E) then
4186 goto Potentially_Use_Visible_Entity;
4188 -- Note if a known but invisible entity encountered
4190 elsif Known_But_Invisible (E) then
4191 Nvis_Entity := True;
4194 -- Move to next entity in chain and continue search
4199 -- If no entries on homonym chain that were potentially visible,
4200 -- and no entities reasonably considered as non-visible, then
4201 -- we have a plain undefined reference, with no additional
4202 -- explanation required!
4204 if not Nvis_Entity then
4205 Undefined (Nvis => False);
4207 -- Otherwise there is at least one entry on the homonym chain that
4208 -- is reasonably considered as being known and non-visible.
4216 -- Processing for a potentially use visible entry found. We must search
4217 -- the rest of the homonym chain for two reasons. First, if there is a
4218 -- directly visible entry, then none of the potentially use-visible
4219 -- entities are directly visible (RM 8.4(10)). Second, we need to check
4220 -- for the case of multiple potentially use-visible entries hiding one
4221 -- another and as a result being non-directly visible (RM 8.4(11)).
4223 <<Potentially_Use_Visible_Entity>> declare
4224 Only_One_Visible : Boolean := True;
4225 All_Overloadable : Boolean := Is_Overloadable (E);
4229 while Present (E2) loop
4230 if Is_Immediately_Visible (E2) then
4232 -- If the use-visible entity comes from the actual for a
4233 -- formal package, it hides a directly visible entity from
4234 -- outside the instance.
4236 if From_Actual_Package (E)
4237 and then Scope_Depth (E2) < Scope_Depth (Inst)
4242 goto Immediately_Visible_Entity;
4245 elsif Is_Potentially_Use_Visible (E2) then
4246 Only_One_Visible := False;
4247 All_Overloadable := All_Overloadable and Is_Overloadable (E2);
4249 -- Ada 2005 (AI-262): Protect against a form of Beaujolais effect
4250 -- that can occur in private_with clauses. Example:
4253 -- private with B; package A is
4254 -- package C is function B return Integer;
4256 -- V1 : Integer := B;
4257 -- private function B return Integer;
4258 -- V2 : Integer := B;
4261 -- V1 resolves to A.B, but V2 resolves to library unit B
4263 elsif Ekind (E2) = E_Function
4264 and then Scope (E2) = Standard_Standard
4265 and then Has_Private_With (E2)
4267 Only_One_Visible := False;
4268 All_Overloadable := False;
4269 Nvis_Is_Private_Subprg := True;
4276 -- On falling through this loop, we have checked that there are no
4277 -- immediately visible entities. Only_One_Visible is set if exactly
4278 -- one potentially use visible entity exists. All_Overloadable is
4279 -- set if all the potentially use visible entities are overloadable.
4280 -- The condition for legality is that either there is one potentially
4281 -- use visible entity, or if there is more than one, then all of them
4282 -- are overloadable.
4284 if Only_One_Visible or All_Overloadable then
4287 -- If there is more than one potentially use-visible entity and at
4288 -- least one of them non-overloadable, we have an error (RM 8.4(11).
4289 -- Note that E points to the first such entity on the homonym list.
4290 -- Special case: if one of the entities is declared in an actual
4291 -- package, it was visible in the generic, and takes precedence over
4292 -- other entities that are potentially use-visible. Same if it is
4293 -- declared in a local instantiation of the current instance.
4298 -- Find current instance
4300 Inst := Current_Scope;
4301 while Present (Inst)
4302 and then Inst /= Standard_Standard
4304 if Is_Generic_Instance (Inst) then
4308 Inst := Scope (Inst);
4312 while Present (E2) loop
4313 if From_Actual_Package (E2)
4315 (Is_Generic_Instance (Scope (E2))
4316 and then Scope_Depth (Scope (E2)) > Scope_Depth (Inst))
4329 Is_Predefined_File_Name (Unit_File_Name (Current_Sem_Unit))
4331 -- A use-clause in the body of a system file creates conflict
4332 -- with some entity in a user scope, while rtsfind is active.
4333 -- Keep only the entity coming from another predefined unit.
4336 while Present (E2) loop
4337 if Is_Predefined_File_Name
4338 (Unit_File_Name (Get_Source_Unit (Sloc (E2))))
4347 -- Entity must exist because predefined unit is correct
4349 raise Program_Error;
4358 -- Come here with E set to the first immediately visible entity on
4359 -- the homonym chain. This is the one we want unless there is another
4360 -- immediately visible entity further on in the chain for an inner
4361 -- scope (RM 8.3(8)).
4363 <<Immediately_Visible_Entity>> declare
4368 -- Find scope level of initial entity. When compiling through
4369 -- Rtsfind, the previous context is not completely invisible, and
4370 -- an outer entity may appear on the chain, whose scope is below
4371 -- the entry for Standard that delimits the current scope stack.
4372 -- Indicate that the level for this spurious entry is outside of
4373 -- the current scope stack.
4375 Level := Scope_Stack.Last;
4377 Scop := Scope_Stack.Table (Level).Entity;
4378 exit when Scop = Scope (E);
4380 exit when Scop = Standard_Standard;
4383 -- Now search remainder of homonym chain for more inner entry
4384 -- If the entity is Standard itself, it has no scope, and we
4385 -- compare it with the stack entry directly.
4388 while Present (E2) loop
4389 if Is_Immediately_Visible (E2) then
4391 -- If a generic package contains a local declaration that
4392 -- has the same name as the generic, there may be a visibility
4393 -- conflict in an instance, where the local declaration must
4394 -- also hide the name of the corresponding package renaming.
4395 -- We check explicitly for a package declared by a renaming,
4396 -- whose renamed entity is an instance that is on the scope
4397 -- stack, and that contains a homonym in the same scope. Once
4398 -- we have found it, we know that the package renaming is not
4399 -- immediately visible, and that the identifier denotes the
4400 -- other entity (and its homonyms if overloaded).
4402 if Scope (E) = Scope (E2)
4403 and then Ekind (E) = E_Package
4404 and then Present (Renamed_Object (E))
4405 and then Is_Generic_Instance (Renamed_Object (E))
4406 and then In_Open_Scopes (Renamed_Object (E))
4407 and then Comes_From_Source (N)
4409 Set_Is_Immediately_Visible (E, False);
4413 for J in Level + 1 .. Scope_Stack.Last loop
4414 if Scope_Stack.Table (J).Entity = Scope (E2)
4415 or else Scope_Stack.Table (J).Entity = E2
4428 -- At the end of that loop, E is the innermost immediately
4429 -- visible entity, so we are all set.
4432 -- Come here with entity found, and stored in E
4436 -- Check violation of No_Wide_Characters restriction
4438 Check_Wide_Character_Restriction (E, N);
4440 -- When distribution features are available (Get_PCS_Name /=
4441 -- Name_No_DSA), a remote access-to-subprogram type is converted
4442 -- into a record type holding whatever information is needed to
4443 -- perform a remote call on an RCI subprogram. In that case we
4444 -- rewrite any occurrence of the RAS type into the equivalent record
4445 -- type here. 'Access attribute references and RAS dereferences are
4446 -- then implemented using specific TSSs. However when distribution is
4447 -- not available (case of Get_PCS_Name = Name_No_DSA), we bypass the
4448 -- generation of these TSSs, and we must keep the RAS type in its
4449 -- original access-to-subprogram form (since all calls through a
4450 -- value of such type will be local anyway in the absence of a PCS).
4452 if Comes_From_Source (N)
4453 and then Is_Remote_Access_To_Subprogram_Type (E)
4454 and then Expander_Active
4455 and then Get_PCS_Name /= Name_No_DSA
4458 New_Occurrence_Of (Equivalent_Type (E), Sloc (N)));
4462 -- Set the entity. Note that the reason we call Set_Entity for the
4463 -- overloadable case, as opposed to Set_Entity_With_Style_Check is
4464 -- that in the overloaded case, the initial call can set the wrong
4465 -- homonym. The call that sets the right homonym is in Sem_Res and
4466 -- that call does use Set_Entity_With_Style_Check, so we don't miss
4469 if Is_Overloadable (E) then
4472 Set_Entity_With_Style_Check (N, E);
4478 Set_Etype (N, Get_Full_View (Etype (E)));
4481 if Debug_Flag_E then
4482 Write_Str (" found ");
4483 Write_Entity_Info (E, " ");
4486 -- If the Ekind of the entity is Void, it means that all homonyms
4487 -- are hidden from all visibility (RM 8.3(5,14-20)). However, this
4488 -- test is skipped if the current scope is a record and the name is
4489 -- a pragma argument expression (case of Atomic and Volatile pragmas
4490 -- and possibly other similar pragmas added later, which are allowed
4491 -- to reference components in the current record).
4493 if Ekind (E) = E_Void
4495 (not Is_Record_Type (Current_Scope)
4496 or else Nkind (Parent (N)) /= N_Pragma_Argument_Association)
4498 Premature_Usage (N);
4500 -- If the entity is overloadable, collect all interpretations of the
4501 -- name for subsequent overload resolution. We optimize a bit here to
4502 -- do this only if we have an overloadable entity that is not on its
4503 -- own on the homonym chain.
4505 elsif Is_Overloadable (E)
4506 and then (Present (Homonym (E)) or else Current_Entity (N) /= E)
4508 Collect_Interps (N);
4510 -- If no homonyms were visible, the entity is unambiguous
4512 if not Is_Overloaded (N) then
4513 if not Is_Actual_Parameter then
4514 Generate_Reference (E, N);
4518 -- Case of non-overloadable entity, set the entity providing that
4519 -- we do not have the case of a discriminant reference within a
4520 -- default expression. Such references are replaced with the
4521 -- corresponding discriminal, which is the formal corresponding to
4522 -- to the discriminant in the initialization procedure.
4525 -- Entity is unambiguous, indicate that it is referenced here
4527 -- For a renaming of an object, always generate simple reference,
4528 -- we don't try to keep track of assignments in this case.
4530 if Is_Object (E) and then Present (Renamed_Object (E)) then
4531 Generate_Reference (E, N);
4533 -- If the renamed entity is a private protected component,
4534 -- reference the original component as well. This needs to be
4535 -- done because the private renamings are installed before any
4536 -- analysis has occurred. Reference to a private component will
4537 -- resolve to the renaming and the original component will be
4538 -- left unreferenced, hence the following.
4540 if Is_Prival (E) then
4541 Generate_Reference (Prival_Link (E), N);
4544 -- One odd case is that we do not want to set the Referenced flag
4545 -- if the entity is a label, and the identifier is the label in
4546 -- the source, since this is not a reference from the point of
4547 -- view of the user.
4549 elsif Nkind (Parent (N)) = N_Label then
4551 R : constant Boolean := Referenced (E);
4554 -- Generate reference unless this is an actual parameter
4555 -- (see comment below)
4557 if Is_Actual_Parameter then
4558 Generate_Reference (E, N);
4559 Set_Referenced (E, R);
4563 -- Normal case, not a label: generate reference
4565 -- ??? It is too early to generate a reference here even if
4566 -- the entity is unambiguous, because the tree is not
4567 -- sufficiently typed at this point for Generate_Reference to
4568 -- determine whether this reference modifies the denoted object
4569 -- (because implicit dereferences cannot be identified prior to
4570 -- full type resolution).
4572 -- The Is_Actual_Parameter routine takes care of one of these
4573 -- cases but there are others probably ???
4576 if not Is_Actual_Parameter then
4577 Generate_Reference (E, N);
4580 Check_Nested_Access (E);
4583 Set_Entity_Or_Discriminal (N, E);
4586 end Find_Direct_Name;
4588 ------------------------
4589 -- Find_Expanded_Name --
4590 ------------------------
4592 -- This routine searches the homonym chain of the entity until it finds
4593 -- an entity declared in the scope denoted by the prefix. If the entity
4594 -- is private, it may nevertheless be immediately visible, if we are in
4595 -- the scope of its declaration.
4597 procedure Find_Expanded_Name (N : Node_Id) is
4598 Selector : constant Node_Id := Selector_Name (N);
4599 Candidate : Entity_Id := Empty;
4605 P_Name := Entity (Prefix (N));
4608 -- If the prefix is a renamed package, look for the entity in the
4609 -- original package.
4611 if Ekind (P_Name) = E_Package
4612 and then Present (Renamed_Object (P_Name))
4614 P_Name := Renamed_Object (P_Name);
4616 -- Rewrite node with entity field pointing to renamed object
4618 Rewrite (Prefix (N), New_Copy (Prefix (N)));
4619 Set_Entity (Prefix (N), P_Name);
4621 -- If the prefix is an object of a concurrent type, look for
4622 -- the entity in the associated task or protected type.
4624 elsif Is_Concurrent_Type (Etype (P_Name)) then
4625 P_Name := Etype (P_Name);
4628 Id := Current_Entity (Selector);
4631 Is_New_Candidate : Boolean;
4634 while Present (Id) loop
4635 if Scope (Id) = P_Name then
4637 Is_New_Candidate := True;
4639 -- Ada 2005 (AI-217): Handle shadow entities associated with types
4640 -- declared in limited-withed nested packages. We don't need to
4641 -- handle E_Incomplete_Subtype entities because the entities in
4642 -- the limited view are always E_Incomplete_Type entities (see
4643 -- Build_Limited_Views). Regarding the expression used to evaluate
4644 -- the scope, it is important to note that the limited view also
4645 -- has shadow entities associated nested packages. For this reason
4646 -- the correct scope of the entity is the scope of the real entity
4647 -- The non-limited view may itself be incomplete, in which case
4648 -- get the full view if available.
4650 elsif From_With_Type (Id)
4651 and then Is_Type (Id)
4652 and then Ekind (Id) = E_Incomplete_Type
4653 and then Present (Non_Limited_View (Id))
4654 and then Scope (Non_Limited_View (Id)) = P_Name
4656 Candidate := Get_Full_View (Non_Limited_View (Id));
4657 Is_New_Candidate := True;
4660 Is_New_Candidate := False;
4663 if Is_New_Candidate then
4664 if Is_Child_Unit (Id) then
4665 exit when Is_Visible_Child_Unit (Id)
4666 or else Is_Immediately_Visible (Id);
4669 exit when not Is_Hidden (Id)
4670 or else Is_Immediately_Visible (Id);
4679 and then (Ekind (P_Name) = E_Procedure
4681 Ekind (P_Name) = E_Function)
4682 and then Is_Generic_Instance (P_Name)
4684 -- Expanded name denotes entity in (instance of) generic subprogram.
4685 -- The entity may be in the subprogram instance, or may denote one of
4686 -- the formals, which is declared in the enclosing wrapper package.
4688 P_Name := Scope (P_Name);
4690 Id := Current_Entity (Selector);
4691 while Present (Id) loop
4692 exit when Scope (Id) = P_Name;
4697 if No (Id) or else Chars (Id) /= Chars (Selector) then
4698 Set_Etype (N, Any_Type);
4700 -- If we are looking for an entity defined in System, try to find it
4701 -- in the child package that may have been provided as an extension
4702 -- to System. The Extend_System pragma will have supplied the name of
4703 -- the extension, which may have to be loaded.
4705 if Chars (P_Name) = Name_System
4706 and then Scope (P_Name) = Standard_Standard
4707 and then Present (System_Extend_Unit)
4708 and then Present_System_Aux (N)
4710 Set_Entity (Prefix (N), System_Aux_Id);
4711 Find_Expanded_Name (N);
4714 elsif Nkind (Selector) = N_Operator_Symbol
4715 and then Has_Implicit_Operator (N)
4717 -- There is an implicit instance of the predefined operator in
4718 -- the given scope. The operator entity is defined in Standard.
4719 -- Has_Implicit_Operator makes the node into an Expanded_Name.
4723 elsif Nkind (Selector) = N_Character_Literal
4724 and then Has_Implicit_Character_Literal (N)
4726 -- If there is no literal defined in the scope denoted by the
4727 -- prefix, the literal may belong to (a type derived from)
4728 -- Standard_Character, for which we have no explicit literals.
4733 -- If the prefix is a single concurrent object, use its name in
4734 -- the error message, rather than that of the anonymous type.
4736 if Is_Concurrent_Type (P_Name)
4737 and then Is_Internal_Name (Chars (P_Name))
4739 Error_Msg_Node_2 := Entity (Prefix (N));
4741 Error_Msg_Node_2 := P_Name;
4744 if P_Name = System_Aux_Id then
4745 P_Name := Scope (P_Name);
4746 Set_Entity (Prefix (N), P_Name);
4749 if Present (Candidate) then
4751 -- If we know that the unit is a child unit we can give a more
4752 -- accurate error message.
4754 if Is_Child_Unit (Candidate) then
4756 -- If the candidate is a private child unit and we are in
4757 -- the visible part of a public unit, specialize the error
4758 -- message. There might be a private with_clause for it,
4759 -- but it is not currently active.
4761 if Is_Private_Descendant (Candidate)
4762 and then Ekind (Current_Scope) = E_Package
4763 and then not In_Private_Part (Current_Scope)
4764 and then not Is_Private_Descendant (Current_Scope)
4766 Error_Msg_N ("private child unit& is not visible here",
4769 -- Normal case where we have a missing with for a child unit
4772 Error_Msg_Qual_Level := 99;
4773 Error_Msg_NE -- CODEFIX
4774 ("missing `WITH &;`", Selector, Candidate);
4775 Error_Msg_Qual_Level := 0;
4778 -- Here we don't know that this is a child unit
4781 Error_Msg_NE ("& is not a visible entity of&", N, Selector);
4785 -- Within the instantiation of a child unit, the prefix may
4786 -- denote the parent instance, but the selector has the name
4787 -- of the original child. Find whether we are within the
4788 -- corresponding instance, and get the proper entity, which
4789 -- can only be an enclosing scope.
4792 and then In_Open_Scopes (P_Name)
4793 and then Is_Generic_Instance (P_Name)
4796 S : Entity_Id := Current_Scope;
4800 for J in reverse 0 .. Scope_Stack.Last loop
4801 S := Scope_Stack.Table (J).Entity;
4803 exit when S = Standard_Standard;
4805 if Ekind_In (S, E_Function,
4809 P := Generic_Parent (Specification
4810 (Unit_Declaration_Node (S)));
4813 and then Chars (Scope (P)) = Chars (O_Name)
4814 and then Chars (P) = Chars (Selector)
4825 -- If this is a selection from Ada, System or Interfaces, then
4826 -- we assume a missing with for the corresponding package.
4828 if Is_Known_Unit (N) then
4829 if not Error_Posted (N) then
4830 Error_Msg_Node_2 := Selector;
4831 Error_Msg_N -- CODEFIX
4832 ("missing `WITH &.&;`", Prefix (N));
4835 -- If this is a selection from a dummy package, then suppress
4836 -- the error message, of course the entity is missing if the
4837 -- package is missing!
4839 elsif Sloc (Error_Msg_Node_2) = No_Location then
4842 -- Here we have the case of an undefined component
4846 -- The prefix may hide a homonym in the context that
4847 -- declares the desired entity. This error can use a
4848 -- specialized message.
4850 if In_Open_Scopes (P_Name)
4851 and then Present (Homonym (P_Name))
4852 and then Is_Compilation_Unit (Homonym (P_Name))
4854 (Is_Immediately_Visible (Homonym (P_Name))
4855 or else Is_Visible_Child_Unit (Homonym (P_Name)))
4858 H : constant Entity_Id := Homonym (P_Name);
4861 Id := First_Entity (H);
4862 while Present (Id) loop
4863 if Chars (Id) = Chars (Selector) then
4864 Error_Msg_Qual_Level := 99;
4865 Error_Msg_Name_1 := Chars (Selector);
4867 ("% not declared in&", N, P_Name);
4869 ("\use fully qualified name starting with"
4870 & " Standard to make& visible", N, H);
4871 Error_Msg_Qual_Level := 0;
4878 -- If not found, standard error message.
4880 Error_Msg_NE ("& not declared in&", N, Selector);
4886 Error_Msg_NE ("& not declared in&", N, Selector);
4889 -- Check for misspelling of some entity in prefix
4891 Id := First_Entity (P_Name);
4892 while Present (Id) loop
4893 if Is_Bad_Spelling_Of (Chars (Id), Chars (Selector))
4894 and then not Is_Internal_Name (Chars (Id))
4896 Error_Msg_NE -- CODEFIX
4897 ("possible misspelling of&", Selector, Id);
4904 -- Specialize the message if this may be an instantiation
4905 -- of a child unit that was not mentioned in the context.
4907 if Nkind (Parent (N)) = N_Package_Instantiation
4908 and then Is_Generic_Instance (Entity (Prefix (N)))
4909 and then Is_Compilation_Unit
4910 (Generic_Parent (Parent (Entity (Prefix (N)))))
4912 Error_Msg_Node_2 := Selector;
4913 Error_Msg_N -- CODEFIX
4914 ("\missing `WITH &.&;`", Prefix (N));
4924 if Comes_From_Source (N)
4925 and then Is_Remote_Access_To_Subprogram_Type (Id)
4926 and then Present (Equivalent_Type (Id))
4928 -- If we are not actually generating distribution code (i.e. the
4929 -- current PCS is the dummy non-distributed version), then the
4930 -- Equivalent_Type will be missing, and Id should be treated as
4931 -- a regular access-to-subprogram type.
4933 Id := Equivalent_Type (Id);
4934 Set_Chars (Selector, Chars (Id));
4937 -- Ada 2005 (AI-50217): Check usage of entities in limited withed units
4939 if Ekind (P_Name) = E_Package
4940 and then From_With_Type (P_Name)
4942 if From_With_Type (Id)
4943 or else Is_Type (Id)
4944 or else Ekind (Id) = E_Package
4949 ("limited withed package can only be used to access "
4950 & "incomplete types",
4955 if Is_Task_Type (P_Name)
4956 and then ((Ekind (Id) = E_Entry
4957 and then Nkind (Parent (N)) /= N_Attribute_Reference)
4959 (Ekind (Id) = E_Entry_Family
4961 Nkind (Parent (Parent (N))) /= N_Attribute_Reference))
4963 -- It is an entry call after all, either to the current task (which
4964 -- will deadlock) or to an enclosing task.
4966 Analyze_Selected_Component (N);
4970 Change_Selected_Component_To_Expanded_Name (N);
4972 -- Do style check and generate reference, but skip both steps if this
4973 -- entity has homonyms, since we may not have the right homonym set yet.
4974 -- The proper homonym will be set during the resolve phase.
4976 if Has_Homonym (Id) then
4979 Set_Entity_Or_Discriminal (N, Id);
4980 Generate_Reference (Id, N);
4983 if Is_Type (Id) then
4986 Set_Etype (N, Get_Full_View (Etype (Id)));
4989 -- Check for violation of No_Wide_Characters
4991 Check_Wide_Character_Restriction (Id, N);
4993 -- If the Ekind of the entity is Void, it means that all homonyms are
4994 -- hidden from all visibility (RM 8.3(5,14-20)).
4996 if Ekind (Id) = E_Void then
4997 Premature_Usage (N);
4999 elsif Is_Overloadable (Id)
5000 and then Present (Homonym (Id))
5003 H : Entity_Id := Homonym (Id);
5006 while Present (H) loop
5007 if Scope (H) = Scope (Id)
5010 or else Is_Immediately_Visible (H))
5012 Collect_Interps (N);
5019 -- If an extension of System is present, collect possible explicit
5020 -- overloadings declared in the extension.
5022 if Chars (P_Name) = Name_System
5023 and then Scope (P_Name) = Standard_Standard
5024 and then Present (System_Extend_Unit)
5025 and then Present_System_Aux (N)
5027 H := Current_Entity (Id);
5029 while Present (H) loop
5030 if Scope (H) = System_Aux_Id then
5031 Add_One_Interp (N, H, Etype (H));
5040 if Nkind (Selector_Name (N)) = N_Operator_Symbol
5041 and then Scope (Id) /= Standard_Standard
5043 -- In addition to user-defined operators in the given scope, there
5044 -- may be an implicit instance of the predefined operator. The
5045 -- operator (defined in Standard) is found in Has_Implicit_Operator,
5046 -- and added to the interpretations. Procedure Add_One_Interp will
5047 -- determine which hides which.
5049 if Has_Implicit_Operator (N) then
5053 end Find_Expanded_Name;
5055 -------------------------
5056 -- Find_Renamed_Entity --
5057 -------------------------
5059 function Find_Renamed_Entity
5063 Is_Actual : Boolean := False) return Entity_Id
5066 I1 : Interp_Index := 0; -- Suppress junk warnings
5072 function Enclosing_Instance return Entity_Id;
5073 -- If the renaming determines the entity for the default of a formal
5074 -- subprogram nested within another instance, choose the innermost
5075 -- candidate. This is because if the formal has a box, and we are within
5076 -- an enclosing instance where some candidate interpretations are local
5077 -- to this enclosing instance, we know that the default was properly
5078 -- resolved when analyzing the generic, so we prefer the local
5079 -- candidates to those that are external. This is not always the case
5080 -- but is a reasonable heuristic on the use of nested generics. The
5081 -- proper solution requires a full renaming model.
5083 function Is_Visible_Operation (Op : Entity_Id) return Boolean;
5084 -- If the renamed entity is an implicit operator, check whether it is
5085 -- visible because its operand type is properly visible. This check
5086 -- applies to explicit renamed entities that appear in the source in a
5087 -- renaming declaration or a formal subprogram instance, but not to
5088 -- default generic actuals with a name.
5090 function Report_Overload return Entity_Id;
5091 -- List possible interpretations, and specialize message in the
5092 -- case of a generic actual.
5094 function Within (Inner, Outer : Entity_Id) return Boolean;
5095 -- Determine whether a candidate subprogram is defined within the
5096 -- enclosing instance. If yes, it has precedence over outer candidates.
5098 ------------------------
5099 -- Enclosing_Instance --
5100 ------------------------
5102 function Enclosing_Instance return Entity_Id is
5106 if not Is_Generic_Instance (Current_Scope)
5107 and then not Is_Actual
5112 S := Scope (Current_Scope);
5113 while S /= Standard_Standard loop
5114 if Is_Generic_Instance (S) then
5122 end Enclosing_Instance;
5124 --------------------------
5125 -- Is_Visible_Operation --
5126 --------------------------
5128 function Is_Visible_Operation (Op : Entity_Id) return Boolean is
5134 if Ekind (Op) /= E_Operator
5135 or else Scope (Op) /= Standard_Standard
5136 or else (In_Instance
5139 or else Present (Enclosing_Instance)))
5144 -- For a fixed point type operator, check the resulting type,
5145 -- because it may be a mixed mode integer * fixed operation.
5147 if Present (Next_Formal (First_Formal (New_S)))
5148 and then Is_Fixed_Point_Type (Etype (New_S))
5150 Typ := Etype (New_S);
5152 Typ := Etype (First_Formal (New_S));
5155 Btyp := Base_Type (Typ);
5157 if Nkind (Nam) /= N_Expanded_Name then
5158 return (In_Open_Scopes (Scope (Btyp))
5159 or else Is_Potentially_Use_Visible (Btyp)
5160 or else In_Use (Btyp)
5161 or else In_Use (Scope (Btyp)));
5164 Scop := Entity (Prefix (Nam));
5166 if Ekind (Scop) = E_Package
5167 and then Present (Renamed_Object (Scop))
5169 Scop := Renamed_Object (Scop);
5172 -- Operator is visible if prefix of expanded name denotes
5173 -- scope of type, or else type is defined in System_Aux
5174 -- and the prefix denotes System.
5176 return Scope (Btyp) = Scop
5177 or else (Scope (Btyp) = System_Aux_Id
5178 and then Scope (Scope (Btyp)) = Scop);
5181 end Is_Visible_Operation;
5187 function Within (Inner, Outer : Entity_Id) return Boolean is
5191 Sc := Scope (Inner);
5192 while Sc /= Standard_Standard loop
5203 ---------------------
5204 -- Report_Overload --
5205 ---------------------
5207 function Report_Overload return Entity_Id is
5210 Error_Msg_NE -- CODEFIX
5211 ("ambiguous actual subprogram&, " &
5212 "possible interpretations:", N, Nam);
5214 Error_Msg_N -- CODEFIX
5215 ("ambiguous subprogram, " &
5216 "possible interpretations:", N);
5219 List_Interps (Nam, N);
5221 end Report_Overload;
5223 -- Start of processing for Find_Renamed_Entry
5227 Candidate_Renaming := Empty;
5229 if not Is_Overloaded (Nam) then
5230 if Entity_Matches_Spec (Entity (Nam), New_S) then
5231 Candidate_Renaming := New_S;
5233 if Is_Visible_Operation (Entity (Nam)) then
5234 Old_S := Entity (Nam);
5238 Present (First_Formal (Entity (Nam)))
5239 and then Present (First_Formal (New_S))
5240 and then (Base_Type (Etype (First_Formal (Entity (Nam))))
5241 = Base_Type (Etype (First_Formal (New_S))))
5243 Candidate_Renaming := Entity (Nam);
5247 Get_First_Interp (Nam, Ind, It);
5248 while Present (It.Nam) loop
5249 if Entity_Matches_Spec (It.Nam, New_S)
5250 and then Is_Visible_Operation (It.Nam)
5252 if Old_S /= Any_Id then
5254 -- Note: The call to Disambiguate only happens if a
5255 -- previous interpretation was found, in which case I1
5256 -- has received a value.
5258 It1 := Disambiguate (Nam, I1, Ind, Etype (Old_S));
5260 if It1 = No_Interp then
5261 Inst := Enclosing_Instance;
5263 if Present (Inst) then
5264 if Within (It.Nam, Inst) then
5266 elsif Within (Old_S, Inst) then
5269 return Report_Overload;
5273 return Report_Overload;
5287 Present (First_Formal (It.Nam))
5288 and then Present (First_Formal (New_S))
5289 and then (Base_Type (Etype (First_Formal (It.Nam)))
5290 = Base_Type (Etype (First_Formal (New_S))))
5292 Candidate_Renaming := It.Nam;
5295 Get_Next_Interp (Ind, It);
5298 Set_Entity (Nam, Old_S);
5299 Set_Is_Overloaded (Nam, False);
5303 end Find_Renamed_Entity;
5305 -----------------------------
5306 -- Find_Selected_Component --
5307 -----------------------------
5309 procedure Find_Selected_Component (N : Node_Id) is
5310 P : constant Node_Id := Prefix (N);
5313 -- Entity denoted by prefix
5323 if Nkind (P) = N_Error then
5326 -- If the selector already has an entity, the node has been constructed
5327 -- in the course of expansion, and is known to be valid. Do not verify
5328 -- that it is defined for the type (it may be a private component used
5329 -- in the expansion of record equality).
5331 elsif Present (Entity (Selector_Name (N))) then
5333 or else Etype (N) = Any_Type
5336 Sel_Name : constant Node_Id := Selector_Name (N);
5337 Selector : constant Entity_Id := Entity (Sel_Name);
5341 Set_Etype (Sel_Name, Etype (Selector));
5343 if not Is_Entity_Name (P) then
5347 -- Build an actual subtype except for the first parameter
5348 -- of an init proc, where this actual subtype is by
5349 -- definition incorrect, since the object is uninitialized
5350 -- (and does not even have defined discriminants etc.)
5352 if Is_Entity_Name (P)
5353 and then Ekind (Entity (P)) = E_Function
5355 Nam := New_Copy (P);
5357 if Is_Overloaded (P) then
5358 Save_Interps (P, Nam);
5362 Make_Function_Call (Sloc (P), Name => Nam));
5364 Analyze_Selected_Component (N);
5367 elsif Ekind (Selector) = E_Component
5368 and then (not Is_Entity_Name (P)
5369 or else Chars (Entity (P)) /= Name_uInit)
5371 -- Do not build the subtype when referencing components of
5372 -- dispatch table wrappers. Required to avoid generating
5373 -- elaboration code with HI runtimes.
5375 if RTU_Loaded (Ada_Tags)
5376 and then RTE_Available (RE_Dispatch_Table_Wrapper)
5377 and then Scope (Selector) = RTE (RE_Dispatch_Table_Wrapper)
5381 elsif RTU_Loaded (Ada_Tags)
5382 and then RTE_Available (RE_No_Dispatch_Table_Wrapper)
5383 and then Scope (Selector)
5384 = RTE (RE_No_Dispatch_Table_Wrapper)
5390 Build_Actual_Subtype_Of_Component (
5391 Etype (Selector), N);
5398 if No (C_Etype) then
5399 C_Etype := Etype (Selector);
5401 Insert_Action (N, C_Etype);
5402 C_Etype := Defining_Identifier (C_Etype);
5405 Set_Etype (N, C_Etype);
5408 -- If this is the name of an entry or protected operation, and
5409 -- the prefix is an access type, insert an explicit dereference,
5410 -- so that entry calls are treated uniformly.
5412 if Is_Access_Type (Etype (P))
5413 and then Is_Concurrent_Type (Designated_Type (Etype (P)))
5416 New_P : constant Node_Id :=
5417 Make_Explicit_Dereference (Sloc (P),
5418 Prefix => Relocate_Node (P));
5421 Set_Etype (P, Designated_Type (Etype (Prefix (P))));
5425 -- If the selected component appears within a default expression
5426 -- and it has an actual subtype, the pre-analysis has not yet
5427 -- completed its analysis, because Insert_Actions is disabled in
5428 -- that context. Within the init proc of the enclosing type we
5429 -- must complete this analysis, if an actual subtype was created.
5431 elsif Inside_Init_Proc then
5433 Typ : constant Entity_Id := Etype (N);
5434 Decl : constant Node_Id := Declaration_Node (Typ);
5436 if Nkind (Decl) = N_Subtype_Declaration
5437 and then not Analyzed (Decl)
5438 and then Is_List_Member (Decl)
5439 and then No (Parent (Decl))
5442 Insert_Action (N, Decl);
5449 elsif Is_Entity_Name (P) then
5450 P_Name := Entity (P);
5452 -- The prefix may denote an enclosing type which is the completion
5453 -- of an incomplete type declaration.
5455 if Is_Type (P_Name) then
5456 Set_Entity (P, Get_Full_View (P_Name));
5457 Set_Etype (P, Entity (P));
5458 P_Name := Entity (P);
5461 P_Type := Base_Type (Etype (P));
5463 if Debug_Flag_E then
5464 Write_Str ("Found prefix type to be ");
5465 Write_Entity_Info (P_Type, " "); Write_Eol;
5468 -- First check for components of a record object (not the
5469 -- result of a call, which is handled below).
5471 if Is_Appropriate_For_Record (P_Type)
5472 and then not Is_Overloadable (P_Name)
5473 and then not Is_Type (P_Name)
5475 -- Selected component of record. Type checking will validate
5476 -- name of selector.
5477 -- ??? could we rewrite an implicit dereference into an explicit
5480 Analyze_Selected_Component (N);
5482 -- Reference to type name in predicate/invariant expression
5484 elsif OK_To_Reference (Etype (P)) then
5485 Analyze_Selected_Component (N);
5487 elsif Is_Appropriate_For_Entry_Prefix (P_Type)
5488 and then not In_Open_Scopes (P_Name)
5489 and then (not Is_Concurrent_Type (Etype (P_Name))
5490 or else not In_Open_Scopes (Etype (P_Name)))
5492 -- Call to protected operation or entry. Type checking is
5493 -- needed on the prefix.
5495 Analyze_Selected_Component (N);
5497 elsif (In_Open_Scopes (P_Name)
5498 and then Ekind (P_Name) /= E_Void
5499 and then not Is_Overloadable (P_Name))
5500 or else (Is_Concurrent_Type (Etype (P_Name))
5501 and then In_Open_Scopes (Etype (P_Name)))
5503 -- Prefix denotes an enclosing loop, block, or task, i.e. an
5504 -- enclosing construct that is not a subprogram or accept.
5506 Find_Expanded_Name (N);
5508 elsif Ekind (P_Name) = E_Package then
5509 Find_Expanded_Name (N);
5511 elsif Is_Overloadable (P_Name) then
5513 -- The subprogram may be a renaming (of an enclosing scope) as
5514 -- in the case of the name of the generic within an instantiation.
5516 if Ekind_In (P_Name, E_Procedure, E_Function)
5517 and then Present (Alias (P_Name))
5518 and then Is_Generic_Instance (Alias (P_Name))
5520 P_Name := Alias (P_Name);
5523 if Is_Overloaded (P) then
5525 -- The prefix must resolve to a unique enclosing construct
5528 Found : Boolean := False;
5533 Get_First_Interp (P, Ind, It);
5534 while Present (It.Nam) loop
5535 if In_Open_Scopes (It.Nam) then
5538 "prefix must be unique enclosing scope", N);
5539 Set_Entity (N, Any_Id);
5540 Set_Etype (N, Any_Type);
5549 Get_Next_Interp (Ind, It);
5554 if In_Open_Scopes (P_Name) then
5555 Set_Entity (P, P_Name);
5556 Set_Is_Overloaded (P, False);
5557 Find_Expanded_Name (N);
5560 -- If no interpretation as an expanded name is possible, it
5561 -- must be a selected component of a record returned by a
5562 -- function call. Reformat prefix as a function call, the rest
5563 -- is done by type resolution. If the prefix is procedure or
5564 -- entry, as is P.X; this is an error.
5566 if Ekind (P_Name) /= E_Function
5567 and then (not Is_Overloaded (P)
5569 Nkind (Parent (N)) = N_Procedure_Call_Statement)
5571 -- Prefix may mention a package that is hidden by a local
5572 -- declaration: let the user know. Scan the full homonym
5573 -- chain, the candidate package may be anywhere on it.
5575 if Present (Homonym (Current_Entity (P_Name))) then
5577 P_Name := Current_Entity (P_Name);
5579 while Present (P_Name) loop
5580 exit when Ekind (P_Name) = E_Package;
5581 P_Name := Homonym (P_Name);
5584 if Present (P_Name) then
5585 Error_Msg_Sloc := Sloc (Entity (Prefix (N)));
5588 ("package& is hidden by declaration#",
5591 Set_Entity (Prefix (N), P_Name);
5592 Find_Expanded_Name (N);
5595 P_Name := Entity (Prefix (N));
5600 ("invalid prefix in selected component&", N, P_Name);
5601 Change_Selected_Component_To_Expanded_Name (N);
5602 Set_Entity (N, Any_Id);
5603 Set_Etype (N, Any_Type);
5606 Nam := New_Copy (P);
5607 Save_Interps (P, Nam);
5609 Make_Function_Call (Sloc (P), Name => Nam));
5611 Analyze_Selected_Component (N);
5615 -- Remaining cases generate various error messages
5618 -- Format node as expanded name, to avoid cascaded errors
5620 Change_Selected_Component_To_Expanded_Name (N);
5621 Set_Entity (N, Any_Id);
5622 Set_Etype (N, Any_Type);
5624 -- Issue error message, but avoid this if error issued already.
5625 -- Use identifier of prefix if one is available.
5627 if P_Name = Any_Id then
5630 elsif Ekind (P_Name) = E_Void then
5631 Premature_Usage (P);
5633 elsif Nkind (P) /= N_Attribute_Reference then
5635 "invalid prefix in selected component&", P);
5637 if Is_Access_Type (P_Type)
5638 and then Ekind (Designated_Type (P_Type)) = E_Incomplete_Type
5641 ("\dereference must not be of an incomplete type " &
5647 "invalid prefix in selected component", P);
5652 -- If prefix is not the name of an entity, it must be an expression,
5653 -- whose type is appropriate for a record. This is determined by
5656 Analyze_Selected_Component (N);
5658 end Find_Selected_Component;
5664 procedure Find_Type (N : Node_Id) is
5674 elsif Nkind (N) = N_Attribute_Reference then
5676 -- Class attribute. This is not valid in Ada 83 mode, but we do not
5677 -- need to enforce that at this point, since the declaration of the
5678 -- tagged type in the prefix would have been flagged already.
5680 if Attribute_Name (N) = Name_Class then
5681 Check_Restriction (No_Dispatch, N);
5682 Find_Type (Prefix (N));
5684 -- Propagate error from bad prefix
5686 if Etype (Prefix (N)) = Any_Type then
5687 Set_Entity (N, Any_Type);
5688 Set_Etype (N, Any_Type);
5692 T := Base_Type (Entity (Prefix (N)));
5694 -- Case where type is not known to be tagged. Its appearance in
5695 -- the prefix of the 'Class attribute indicates that the full view
5698 if not Is_Tagged_Type (T) then
5699 if Ekind (T) = E_Incomplete_Type then
5701 -- It is legal to denote the class type of an incomplete
5702 -- type. The full type will have to be tagged, of course.
5703 -- In Ada 2005 this usage is declared obsolescent, so we
5704 -- warn accordingly. This usage is only legal if the type
5705 -- is completed in the current scope, and not for a limited
5708 if not Is_Tagged_Type (T)
5709 and then Ada_Version >= Ada_2005
5711 if From_With_Type (T) then
5713 ("prefix of Class attribute must be tagged", N);
5714 Set_Etype (N, Any_Type);
5715 Set_Entity (N, Any_Type);
5718 -- ??? This test is temporarily disabled (always False)
5719 -- because it causes an unwanted warning on GNAT sources
5720 -- (built with -gnatg, which includes Warn_On_Obsolescent_
5721 -- Feature). Once this issue is cleared in the sources, it
5724 elsif Warn_On_Obsolescent_Feature
5728 ("applying 'Class to an untagged incomplete type"
5729 & " is an obsolescent feature (RM J.11)", N);
5733 Set_Is_Tagged_Type (T);
5734 Set_Direct_Primitive_Operations (T, New_Elmt_List);
5735 Make_Class_Wide_Type (T);
5736 Set_Entity (N, Class_Wide_Type (T));
5737 Set_Etype (N, Class_Wide_Type (T));
5739 elsif Ekind (T) = E_Private_Type
5740 and then not Is_Generic_Type (T)
5741 and then In_Private_Part (Scope (T))
5743 -- The Class attribute can be applied to an untagged private
5744 -- type fulfilled by a tagged type prior to the full type
5745 -- declaration (but only within the parent package's private
5746 -- part). Create the class-wide type now and check that the
5747 -- full type is tagged later during its analysis. Note that
5748 -- we do not mark the private type as tagged, unlike the
5749 -- case of incomplete types, because the type must still
5750 -- appear untagged to outside units.
5752 if No (Class_Wide_Type (T)) then
5753 Make_Class_Wide_Type (T);
5756 Set_Entity (N, Class_Wide_Type (T));
5757 Set_Etype (N, Class_Wide_Type (T));
5760 -- Should we introduce a type Any_Tagged and use Wrong_Type
5761 -- here, it would be a bit more consistent???
5764 ("tagged type required, found}",
5765 Prefix (N), First_Subtype (T));
5766 Set_Entity (N, Any_Type);
5770 -- Case of tagged type
5773 if Is_Concurrent_Type (T) then
5774 if No (Corresponding_Record_Type (Entity (Prefix (N)))) then
5776 -- Previous error. Use current type, which at least
5777 -- provides some operations.
5779 C := Entity (Prefix (N));
5782 C := Class_Wide_Type
5783 (Corresponding_Record_Type (Entity (Prefix (N))));
5787 C := Class_Wide_Type (Entity (Prefix (N)));
5790 Set_Entity_With_Style_Check (N, C);
5791 Generate_Reference (C, N);
5795 -- Base attribute, not allowed in Ada 83
5797 elsif Attribute_Name (N) = Name_Base then
5798 if Ada_Version = Ada_83 and then Comes_From_Source (N) then
5800 ("(Ada 83) Base attribute not allowed in subtype mark", N);
5803 Find_Type (Prefix (N));
5804 Typ := Entity (Prefix (N));
5806 if Ada_Version >= Ada_95
5807 and then not Is_Scalar_Type (Typ)
5808 and then not Is_Generic_Type (Typ)
5811 ("prefix of Base attribute must be scalar type",
5814 elsif Warn_On_Redundant_Constructs
5815 and then Base_Type (Typ) = Typ
5817 Error_Msg_NE -- CODEFIX
5818 ("?redundant attribute, & is its own base type", N, Typ);
5821 T := Base_Type (Typ);
5823 -- Rewrite attribute reference with type itself (see similar
5824 -- processing in Analyze_Attribute, case Base). Preserve prefix
5825 -- if present, for other legality checks.
5827 if Nkind (Prefix (N)) = N_Expanded_Name then
5829 Make_Expanded_Name (Sloc (N),
5831 Prefix => New_Copy (Prefix (Prefix (N))),
5832 Selector_Name => New_Reference_To (T, Sloc (N))));
5835 Rewrite (N, New_Reference_To (T, Sloc (N)));
5842 elsif Attribute_Name (N) = Name_Stub_Type then
5844 -- This is handled in Analyze_Attribute
5848 -- All other attributes are invalid in a subtype mark
5851 Error_Msg_N ("invalid attribute in subtype mark", N);
5857 if Is_Entity_Name (N) then
5858 T_Name := Entity (N);
5860 Error_Msg_N ("subtype mark required in this context", N);
5861 Set_Etype (N, Any_Type);
5865 if T_Name = Any_Id or else Etype (N) = Any_Type then
5867 -- Undefined id. Make it into a valid type
5869 Set_Entity (N, Any_Type);
5871 elsif not Is_Type (T_Name)
5872 and then T_Name /= Standard_Void_Type
5874 Error_Msg_Sloc := Sloc (T_Name);
5875 Error_Msg_N ("subtype mark required in this context", N);
5876 Error_Msg_NE ("\\found & declared#", N, T_Name);
5877 Set_Entity (N, Any_Type);
5880 -- If the type is an incomplete type created to handle
5881 -- anonymous access components of a record type, then the
5882 -- incomplete type is the visible entity and subsequent
5883 -- references will point to it. Mark the original full
5884 -- type as referenced, to prevent spurious warnings.
5886 if Is_Incomplete_Type (T_Name)
5887 and then Present (Full_View (T_Name))
5888 and then not Comes_From_Source (T_Name)
5890 Set_Referenced (Full_View (T_Name));
5893 T_Name := Get_Full_View (T_Name);
5895 -- Ada 2005 (AI-251, AI-50217): Handle interfaces visible through
5896 -- limited-with clauses
5898 if From_With_Type (T_Name)
5899 and then Ekind (T_Name) in Incomplete_Kind
5900 and then Present (Non_Limited_View (T_Name))
5901 and then Is_Interface (Non_Limited_View (T_Name))
5903 T_Name := Non_Limited_View (T_Name);
5906 if In_Open_Scopes (T_Name) then
5907 if Ekind (Base_Type (T_Name)) = E_Task_Type then
5909 -- In Ada 2005, a task name can be used in an access
5910 -- definition within its own body. It cannot be used
5911 -- in the discriminant part of the task declaration,
5912 -- nor anywhere else in the declaration because entries
5913 -- cannot have access parameters.
5915 if Ada_Version >= Ada_2005
5916 and then Nkind (Parent (N)) = N_Access_Definition
5918 Set_Entity (N, T_Name);
5919 Set_Etype (N, T_Name);
5921 if Has_Completion (T_Name) then
5926 ("task type cannot be used as type mark " &
5927 "within its own declaration", N);
5932 ("task type cannot be used as type mark " &
5933 "within its own spec or body", N);
5936 elsif Ekind (Base_Type (T_Name)) = E_Protected_Type then
5938 -- In Ada 2005, a protected name can be used in an access
5939 -- definition within its own body.
5941 if Ada_Version >= Ada_2005
5942 and then Nkind (Parent (N)) = N_Access_Definition
5944 Set_Entity (N, T_Name);
5945 Set_Etype (N, T_Name);
5950 ("protected type cannot be used as type mark " &
5951 "within its own spec or body", N);
5955 Error_Msg_N ("type declaration cannot refer to itself", N);
5958 Set_Etype (N, Any_Type);
5959 Set_Entity (N, Any_Type);
5960 Set_Error_Posted (T_Name);
5964 Set_Entity (N, T_Name);
5965 Set_Etype (N, T_Name);
5969 if Present (Etype (N)) and then Comes_From_Source (N) then
5970 if Is_Fixed_Point_Type (Etype (N)) then
5971 Check_Restriction (No_Fixed_Point, N);
5972 elsif Is_Floating_Point_Type (Etype (N)) then
5973 Check_Restriction (No_Floating_Point, N);
5978 ------------------------------------
5979 -- Has_Implicit_Character_Literal --
5980 ------------------------------------
5982 function Has_Implicit_Character_Literal (N : Node_Id) return Boolean is
5984 Found : Boolean := False;
5985 P : constant Entity_Id := Entity (Prefix (N));
5986 Priv_Id : Entity_Id := Empty;
5989 if Ekind (P) = E_Package
5990 and then not In_Open_Scopes (P)
5992 Priv_Id := First_Private_Entity (P);
5995 if P = Standard_Standard then
5996 Change_Selected_Component_To_Expanded_Name (N);
5997 Rewrite (N, Selector_Name (N));
5999 Set_Etype (Original_Node (N), Standard_Character);
6003 Id := First_Entity (P);
6005 and then Id /= Priv_Id
6007 if Is_Standard_Character_Type (Id)
6008 and then Id = Base_Type (Id)
6010 -- We replace the node with the literal itself, resolve as a
6011 -- character, and set the type correctly.
6014 Change_Selected_Component_To_Expanded_Name (N);
6015 Rewrite (N, Selector_Name (N));
6018 Set_Etype (Original_Node (N), Id);
6022 -- More than one type derived from Character in given scope.
6023 -- Collect all possible interpretations.
6025 Add_One_Interp (N, Id, Id);
6033 end Has_Implicit_Character_Literal;
6035 ----------------------
6036 -- Has_Private_With --
6037 ----------------------
6039 function Has_Private_With (E : Entity_Id) return Boolean is
6040 Comp_Unit : constant Node_Id := Cunit (Current_Sem_Unit);
6044 Item := First (Context_Items (Comp_Unit));
6045 while Present (Item) loop
6046 if Nkind (Item) = N_With_Clause
6047 and then Private_Present (Item)
6048 and then Entity (Name (Item)) = E
6057 end Has_Private_With;
6059 ---------------------------
6060 -- Has_Implicit_Operator --
6061 ---------------------------
6063 function Has_Implicit_Operator (N : Node_Id) return Boolean is
6064 Op_Id : constant Name_Id := Chars (Selector_Name (N));
6065 P : constant Entity_Id := Entity (Prefix (N));
6067 Priv_Id : Entity_Id := Empty;
6069 procedure Add_Implicit_Operator
6071 Op_Type : Entity_Id := Empty);
6072 -- Add implicit interpretation to node N, using the type for which a
6073 -- predefined operator exists. If the operator yields a boolean type,
6074 -- the Operand_Type is implicitly referenced by the operator, and a
6075 -- reference to it must be generated.
6077 ---------------------------
6078 -- Add_Implicit_Operator --
6079 ---------------------------
6081 procedure Add_Implicit_Operator
6083 Op_Type : Entity_Id := Empty)
6085 Predef_Op : Entity_Id;
6088 Predef_Op := Current_Entity (Selector_Name (N));
6090 while Present (Predef_Op)
6091 and then Scope (Predef_Op) /= Standard_Standard
6093 Predef_Op := Homonym (Predef_Op);
6096 if Nkind (N) = N_Selected_Component then
6097 Change_Selected_Component_To_Expanded_Name (N);
6100 -- If the context is an unanalyzed function call, determine whether
6101 -- a binary or unary interpretation is required.
6103 if Nkind (Parent (N)) = N_Indexed_Component then
6105 Is_Binary_Call : constant Boolean :=
6107 (Next (First (Expressions (Parent (N)))));
6108 Is_Binary_Op : constant Boolean :=
6110 (Predef_Op) /= Last_Entity (Predef_Op);
6111 Predef_Op2 : constant Entity_Id := Homonym (Predef_Op);
6114 if Is_Binary_Call then
6115 if Is_Binary_Op then
6116 Add_One_Interp (N, Predef_Op, T);
6118 Add_One_Interp (N, Predef_Op2, T);
6122 if not Is_Binary_Op then
6123 Add_One_Interp (N, Predef_Op, T);
6125 Add_One_Interp (N, Predef_Op2, T);
6131 Add_One_Interp (N, Predef_Op, T);
6133 -- For operators with unary and binary interpretations, if
6134 -- context is not a call, add both
6136 if Present (Homonym (Predef_Op)) then
6137 Add_One_Interp (N, Homonym (Predef_Op), T);
6141 -- The node is a reference to a predefined operator, and
6142 -- an implicit reference to the type of its operands.
6144 if Present (Op_Type) then
6145 Generate_Operator_Reference (N, Op_Type);
6147 Generate_Operator_Reference (N, T);
6149 end Add_Implicit_Operator;
6151 -- Start of processing for Has_Implicit_Operator
6154 if Ekind (P) = E_Package
6155 and then not In_Open_Scopes (P)
6157 Priv_Id := First_Private_Entity (P);
6160 Id := First_Entity (P);
6164 -- Boolean operators: an implicit declaration exists if the scope
6165 -- contains a declaration for a derived Boolean type, or for an
6166 -- array of Boolean type.
6168 when Name_Op_And | Name_Op_Not | Name_Op_Or | Name_Op_Xor =>
6169 while Id /= Priv_Id loop
6170 if Valid_Boolean_Arg (Id)
6171 and then Id = Base_Type (Id)
6173 Add_Implicit_Operator (Id);
6180 -- Equality: look for any non-limited type (result is Boolean)
6182 when Name_Op_Eq | Name_Op_Ne =>
6183 while Id /= Priv_Id loop
6185 and then not Is_Limited_Type (Id)
6186 and then Id = Base_Type (Id)
6188 Add_Implicit_Operator (Standard_Boolean, Id);
6195 -- Comparison operators: scalar type, or array of scalar
6197 when Name_Op_Lt | Name_Op_Le | Name_Op_Gt | Name_Op_Ge =>
6198 while Id /= Priv_Id loop
6199 if (Is_Scalar_Type (Id)
6200 or else (Is_Array_Type (Id)
6201 and then Is_Scalar_Type (Component_Type (Id))))
6202 and then Id = Base_Type (Id)
6204 Add_Implicit_Operator (Standard_Boolean, Id);
6211 -- Arithmetic operators: any numeric type
6221 while Id /= Priv_Id loop
6222 if Is_Numeric_Type (Id)
6223 and then Id = Base_Type (Id)
6225 Add_Implicit_Operator (Id);
6232 -- Concatenation: any one-dimensional array type
6234 when Name_Op_Concat =>
6235 while Id /= Priv_Id loop
6236 if Is_Array_Type (Id) and then Number_Dimensions (Id) = 1
6237 and then Id = Base_Type (Id)
6239 Add_Implicit_Operator (Id);
6246 -- What is the others condition here? Should we be using a
6247 -- subtype of Name_Id that would restrict to operators ???
6249 when others => null;
6252 -- If we fall through, then we do not have an implicit operator
6256 end Has_Implicit_Operator;
6258 --------------------
6259 -- In_Open_Scopes --
6260 --------------------
6262 function In_Open_Scopes (S : Entity_Id) return Boolean is
6264 -- Several scope stacks are maintained by Scope_Stack. The base of the
6265 -- currently active scope stack is denoted by the Is_Active_Stack_Base
6266 -- flag in the scope stack entry. Note that the scope stacks used to
6267 -- simply be delimited implicitly by the presence of Standard_Standard
6268 -- at their base, but there now are cases where this is not sufficient
6269 -- because Standard_Standard actually may appear in the middle of the
6270 -- active set of scopes.
6272 for J in reverse 0 .. Scope_Stack.Last loop
6273 if Scope_Stack.Table (J).Entity = S then
6277 -- Check Is_Active_Stack_Base to tell us when to stop, as there are
6278 -- cases where Standard_Standard appears in the middle of the active
6279 -- set of scopes. This affects the declaration and overriding of
6280 -- private inherited operations in instantiations of generic child
6283 exit when Scope_Stack.Table (J).Is_Active_Stack_Base;
6289 -----------------------------
6290 -- Inherit_Renamed_Profile --
6291 -----------------------------
6293 procedure Inherit_Renamed_Profile (New_S : Entity_Id; Old_S : Entity_Id) is
6300 if Ekind (Old_S) = E_Operator then
6301 New_F := First_Formal (New_S);
6303 while Present (New_F) loop
6304 Set_Etype (New_F, Base_Type (Etype (New_F)));
6305 Next_Formal (New_F);
6308 Set_Etype (New_S, Base_Type (Etype (New_S)));
6311 New_F := First_Formal (New_S);
6312 Old_F := First_Formal (Old_S);
6314 while Present (New_F) loop
6315 New_T := Etype (New_F);
6316 Old_T := Etype (Old_F);
6318 -- If the new type is a renaming of the old one, as is the
6319 -- case for actuals in instances, retain its name, to simplify
6320 -- later disambiguation.
6322 if Nkind (Parent (New_T)) = N_Subtype_Declaration
6323 and then Is_Entity_Name (Subtype_Indication (Parent (New_T)))
6324 and then Entity (Subtype_Indication (Parent (New_T))) = Old_T
6328 Set_Etype (New_F, Old_T);
6331 Next_Formal (New_F);
6332 Next_Formal (Old_F);
6335 if Ekind_In (Old_S, E_Function, E_Enumeration_Literal) then
6336 Set_Etype (New_S, Etype (Old_S));
6339 end Inherit_Renamed_Profile;
6345 procedure Initialize is
6350 -------------------------
6351 -- Install_Use_Clauses --
6352 -------------------------
6354 procedure Install_Use_Clauses
6356 Force_Installation : Boolean := False)
6364 while Present (U) loop
6366 -- Case of USE package
6368 if Nkind (U) = N_Use_Package_Clause then
6369 P := First (Names (U));
6370 while Present (P) loop
6373 if Ekind (Id) = E_Package then
6375 Note_Redundant_Use (P);
6377 elsif Present (Renamed_Object (Id))
6378 and then In_Use (Renamed_Object (Id))
6380 Note_Redundant_Use (P);
6382 elsif Force_Installation or else Applicable_Use (P) then
6383 Use_One_Package (Id, U);
6394 P := First (Subtype_Marks (U));
6395 while Present (P) loop
6396 if not Is_Entity_Name (P)
6397 or else No (Entity (P))
6401 elsif Entity (P) /= Any_Type then
6409 Next_Use_Clause (U);
6411 end Install_Use_Clauses;
6413 -------------------------------------
6414 -- Is_Appropriate_For_Entry_Prefix --
6415 -------------------------------------
6417 function Is_Appropriate_For_Entry_Prefix (T : Entity_Id) return Boolean is
6418 P_Type : Entity_Id := T;
6421 if Is_Access_Type (P_Type) then
6422 P_Type := Designated_Type (P_Type);
6425 return Is_Task_Type (P_Type) or else Is_Protected_Type (P_Type);
6426 end Is_Appropriate_For_Entry_Prefix;
6428 -------------------------------
6429 -- Is_Appropriate_For_Record --
6430 -------------------------------
6432 function Is_Appropriate_For_Record (T : Entity_Id) return Boolean is
6434 function Has_Components (T1 : Entity_Id) return Boolean;
6435 -- Determine if given type has components (i.e. is either a record
6436 -- type or a type that has discriminants).
6438 --------------------
6439 -- Has_Components --
6440 --------------------
6442 function Has_Components (T1 : Entity_Id) return Boolean is
6444 return Is_Record_Type (T1)
6445 or else (Is_Private_Type (T1) and then Has_Discriminants (T1))
6446 or else (Is_Task_Type (T1) and then Has_Discriminants (T1))
6447 or else (Is_Incomplete_Type (T1)
6448 and then From_With_Type (T1)
6449 and then Present (Non_Limited_View (T1))
6450 and then Is_Record_Type
6451 (Get_Full_View (Non_Limited_View (T1))));
6454 -- Start of processing for Is_Appropriate_For_Record
6459 and then (Has_Components (T)
6460 or else (Is_Access_Type (T)
6461 and then Has_Components (Designated_Type (T))));
6462 end Is_Appropriate_For_Record;
6464 ------------------------
6465 -- Note_Redundant_Use --
6466 ------------------------
6468 procedure Note_Redundant_Use (Clause : Node_Id) is
6469 Pack_Name : constant Entity_Id := Entity (Clause);
6470 Cur_Use : constant Node_Id := Current_Use_Clause (Pack_Name);
6471 Decl : constant Node_Id := Parent (Clause);
6473 Prev_Use : Node_Id := Empty;
6474 Redundant : Node_Id := Empty;
6475 -- The Use_Clause which is actually redundant. In the simplest case it
6476 -- is Pack itself, but when we compile a body we install its context
6477 -- before that of its spec, in which case it is the use_clause in the
6478 -- spec that will appear to be redundant, and we want the warning to be
6479 -- placed on the body. Similar complications appear when the redundancy
6480 -- is between a child unit and one of its ancestors.
6483 Set_Redundant_Use (Clause, True);
6485 if not Comes_From_Source (Clause)
6487 or else not Warn_On_Redundant_Constructs
6492 if not Is_Compilation_Unit (Current_Scope) then
6494 -- If the use_clause is in an inner scope, it is made redundant by
6495 -- some clause in the current context, with one exception: If we're
6496 -- compiling a nested package body, and the use_clause comes from the
6497 -- corresponding spec, the clause is not necessarily fully redundant,
6498 -- so we should not warn. If a warning was warranted, it would have
6499 -- been given when the spec was processed.
6501 if Nkind (Parent (Decl)) = N_Package_Specification then
6503 Package_Spec_Entity : constant Entity_Id :=
6504 Defining_Unit_Name (Parent (Decl));
6506 if In_Package_Body (Package_Spec_Entity) then
6512 Redundant := Clause;
6513 Prev_Use := Cur_Use;
6515 elsif Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Body then
6517 Cur_Unit : constant Unit_Number_Type := Get_Source_Unit (Cur_Use);
6518 New_Unit : constant Unit_Number_Type := Get_Source_Unit (Clause);
6522 if Cur_Unit = New_Unit then
6524 -- Redundant clause in same body
6526 Redundant := Clause;
6527 Prev_Use := Cur_Use;
6529 elsif Cur_Unit = Current_Sem_Unit then
6531 -- If the new clause is not in the current unit it has been
6532 -- analyzed first, and it makes the other one redundant.
6533 -- However, if the new clause appears in a subunit, Cur_Unit
6534 -- is still the parent, and in that case the redundant one
6535 -- is the one appearing in the subunit.
6537 if Nkind (Unit (Cunit (New_Unit))) = N_Subunit then
6538 Redundant := Clause;
6539 Prev_Use := Cur_Use;
6541 -- Most common case: redundant clause in body,
6542 -- original clause in spec. Current scope is spec entity.
6547 Unit (Library_Unit (Cunit (Current_Sem_Unit))))
6549 Redundant := Cur_Use;
6553 -- The new clause may appear in an unrelated unit, when
6554 -- the parents of a generic are being installed prior to
6555 -- instantiation. In this case there must be no warning.
6556 -- We detect this case by checking whether the current top
6557 -- of the stack is related to the current compilation.
6559 Scop := Current_Scope;
6560 while Present (Scop)
6561 and then Scop /= Standard_Standard
6563 if Is_Compilation_Unit (Scop)
6564 and then not Is_Child_Unit (Scop)
6568 elsif Scop = Cunit_Entity (Current_Sem_Unit) then
6572 Scop := Scope (Scop);
6575 Redundant := Cur_Use;
6579 elsif New_Unit = Current_Sem_Unit then
6580 Redundant := Clause;
6581 Prev_Use := Cur_Use;
6584 -- Neither is the current unit, so they appear in parent or
6585 -- sibling units. Warning will be emitted elsewhere.
6591 elsif Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Declaration
6592 and then Present (Parent_Spec (Unit (Cunit (Current_Sem_Unit))))
6594 -- Use_clause is in child unit of current unit, and the child unit
6595 -- appears in the context of the body of the parent, so it has been
6596 -- installed first, even though it is the redundant one. Depending on
6597 -- their placement in the context, the visible or the private parts
6598 -- of the two units, either might appear as redundant, but the
6599 -- message has to be on the current unit.
6601 if Get_Source_Unit (Cur_Use) = Current_Sem_Unit then
6602 Redundant := Cur_Use;
6605 Redundant := Clause;
6606 Prev_Use := Cur_Use;
6609 -- If the new use clause appears in the private part of a parent unit
6610 -- it may appear to be redundant w.r.t. a use clause in a child unit,
6611 -- but the previous use clause was needed in the visible part of the
6612 -- child, and no warning should be emitted.
6614 if Nkind (Parent (Decl)) = N_Package_Specification
6616 List_Containing (Decl) = Private_Declarations (Parent (Decl))
6619 Par : constant Entity_Id := Defining_Entity (Parent (Decl));
6620 Spec : constant Node_Id :=
6621 Specification (Unit (Cunit (Current_Sem_Unit)));
6624 if Is_Compilation_Unit (Par)
6625 and then Par /= Cunit_Entity (Current_Sem_Unit)
6626 and then Parent (Cur_Use) = Spec
6628 List_Containing (Cur_Use) = Visible_Declarations (Spec)
6635 -- Finally, if the current use clause is in the context then
6636 -- the clause is redundant when it is nested within the unit.
6638 elsif Nkind (Parent (Cur_Use)) = N_Compilation_Unit
6639 and then Nkind (Parent (Parent (Clause))) /= N_Compilation_Unit
6640 and then Get_Source_Unit (Cur_Use) = Get_Source_Unit (Clause)
6642 Redundant := Clause;
6643 Prev_Use := Cur_Use;
6649 if Present (Redundant) then
6650 Error_Msg_Sloc := Sloc (Prev_Use);
6651 Error_Msg_NE -- CODEFIX
6652 ("& is already use-visible through previous use clause #?",
6653 Redundant, Pack_Name);
6655 end Note_Redundant_Use;
6661 procedure Pop_Scope is
6662 SST : Scope_Stack_Entry renames Scope_Stack.Table (Scope_Stack.Last);
6663 S : constant Entity_Id := SST.Entity;
6666 if Debug_Flag_E then
6670 -- Set Default_Storage_Pool field of the library unit if necessary
6672 if Ekind_In (S, E_Package, E_Generic_Package)
6674 Nkind (Parent (Unit_Declaration_Node (S))) = N_Compilation_Unit
6677 Aux : constant Node_Id :=
6678 Aux_Decls_Node (Parent (Unit_Declaration_Node (S)));
6680 if No (Default_Storage_Pool (Aux)) then
6681 Set_Default_Storage_Pool (Aux, Default_Pool);
6686 Scope_Suppress := SST.Save_Scope_Suppress;
6687 Local_Suppress_Stack_Top := SST.Save_Local_Suppress_Stack_Top;
6688 Check_Policy_List := SST.Save_Check_Policy_List;
6689 Default_Pool := SST.Save_Default_Storage_Pool;
6691 if Debug_Flag_W then
6692 Write_Str ("<-- exiting scope: ");
6693 Write_Name (Chars (Current_Scope));
6694 Write_Str (", Depth=");
6695 Write_Int (Int (Scope_Stack.Last));
6699 End_Use_Clauses (SST.First_Use_Clause);
6701 -- If the actions to be wrapped are still there they will get lost
6702 -- causing incomplete code to be generated. It is better to abort in
6703 -- this case (and we do the abort even with assertions off since the
6704 -- penalty is incorrect code generation)
6706 if SST.Actions_To_Be_Wrapped_Before /= No_List
6708 SST.Actions_To_Be_Wrapped_After /= No_List
6710 raise Program_Error;
6713 -- Free last subprogram name if allocated, and pop scope
6715 Free (SST.Last_Subprogram_Name);
6716 Scope_Stack.Decrement_Last;
6723 procedure Push_Scope (S : Entity_Id) is
6724 E : constant Entity_Id := Scope (S);
6727 if Ekind (S) = E_Void then
6730 -- Set scope depth if not a non-concurrent type, and we have not yet set
6731 -- the scope depth. This means that we have the first occurrence of the
6732 -- scope, and this is where the depth is set.
6734 elsif (not Is_Type (S) or else Is_Concurrent_Type (S))
6735 and then not Scope_Depth_Set (S)
6737 if S = Standard_Standard then
6738 Set_Scope_Depth_Value (S, Uint_0);
6740 elsif Is_Child_Unit (S) then
6741 Set_Scope_Depth_Value (S, Uint_1);
6743 elsif not Is_Record_Type (Current_Scope) then
6744 if Ekind (S) = E_Loop then
6745 Set_Scope_Depth_Value (S, Scope_Depth (Current_Scope));
6747 Set_Scope_Depth_Value (S, Scope_Depth (Current_Scope) + 1);
6752 Scope_Stack.Increment_Last;
6755 SST : Scope_Stack_Entry renames Scope_Stack.Table (Scope_Stack.Last);
6759 SST.Save_Scope_Suppress := Scope_Suppress;
6760 SST.Save_Local_Suppress_Stack_Top := Local_Suppress_Stack_Top;
6761 SST.Save_Check_Policy_List := Check_Policy_List;
6762 SST.Save_Default_Storage_Pool := Default_Pool;
6764 if Scope_Stack.Last > Scope_Stack.First then
6765 SST.Component_Alignment_Default := Scope_Stack.Table
6766 (Scope_Stack.Last - 1).
6767 Component_Alignment_Default;
6770 SST.Last_Subprogram_Name := null;
6771 SST.Is_Transient := False;
6772 SST.Node_To_Be_Wrapped := Empty;
6773 SST.Pending_Freeze_Actions := No_List;
6774 SST.Actions_To_Be_Wrapped_Before := No_List;
6775 SST.Actions_To_Be_Wrapped_After := No_List;
6776 SST.First_Use_Clause := Empty;
6777 SST.Is_Active_Stack_Base := False;
6778 SST.Previous_Visibility := False;
6781 if Debug_Flag_W then
6782 Write_Str ("--> new scope: ");
6783 Write_Name (Chars (Current_Scope));
6784 Write_Str (", Id=");
6785 Write_Int (Int (Current_Scope));
6786 Write_Str (", Depth=");
6787 Write_Int (Int (Scope_Stack.Last));
6791 -- Deal with copying flags from the previous scope to this one. This is
6792 -- not necessary if either scope is standard, or if the new scope is a
6795 if S /= Standard_Standard
6796 and then Scope (S) /= Standard_Standard
6797 and then not Is_Child_Unit (S)
6799 if Nkind (E) not in N_Entity then
6803 -- Copy categorization flags from Scope (S) to S, this is not done
6804 -- when Scope (S) is Standard_Standard since propagation is from
6805 -- library unit entity inwards. Copy other relevant attributes as
6806 -- well (Discard_Names in particular).
6808 -- We only propagate inwards for library level entities,
6809 -- inner level subprograms do not inherit the categorization.
6811 if Is_Library_Level_Entity (S) then
6812 Set_Is_Preelaborated (S, Is_Preelaborated (E));
6813 Set_Is_Shared_Passive (S, Is_Shared_Passive (E));
6814 Set_Discard_Names (S, Discard_Names (E));
6815 Set_Suppress_Value_Tracking_On_Call
6816 (S, Suppress_Value_Tracking_On_Call (E));
6817 Set_Categorization_From_Scope (E => S, Scop => E);
6821 if Is_Child_Unit (S)
6822 and then Present (E)
6823 and then Ekind_In (E, E_Package, E_Generic_Package)
6825 Nkind (Parent (Unit_Declaration_Node (E))) = N_Compilation_Unit
6828 Aux : constant Node_Id :=
6829 Aux_Decls_Node (Parent (Unit_Declaration_Node (E)));
6831 if Present (Default_Storage_Pool (Aux)) then
6832 Default_Pool := Default_Storage_Pool (Aux);
6838 ---------------------
6839 -- Premature_Usage --
6840 ---------------------
6842 procedure Premature_Usage (N : Node_Id) is
6843 Kind : constant Node_Kind := Nkind (Parent (Entity (N)));
6844 E : Entity_Id := Entity (N);
6847 -- Within an instance, the analysis of the actual for a formal object
6848 -- does not see the name of the object itself. This is significant only
6849 -- if the object is an aggregate, where its analysis does not do any
6850 -- name resolution on component associations. (see 4717-008). In such a
6851 -- case, look for the visible homonym on the chain.
6854 and then Present (Homonym (E))
6859 and then not In_Open_Scopes (Scope (E))
6866 Set_Etype (N, Etype (E));
6871 if Kind = N_Component_Declaration then
6873 ("component&! cannot be used before end of record declaration", N);
6875 elsif Kind = N_Parameter_Specification then
6877 ("formal parameter&! cannot be used before end of specification",
6880 elsif Kind = N_Discriminant_Specification then
6882 ("discriminant&! cannot be used before end of discriminant part",
6885 elsif Kind = N_Procedure_Specification
6886 or else Kind = N_Function_Specification
6889 ("subprogram&! cannot be used before end of its declaration",
6892 elsif Kind = N_Full_Type_Declaration then
6894 ("type& cannot be used before end of its declaration!", N);
6898 ("object& cannot be used before end of its declaration!", N);
6900 end Premature_Usage;
6902 ------------------------
6903 -- Present_System_Aux --
6904 ------------------------
6906 function Present_System_Aux (N : Node_Id := Empty) return Boolean is
6908 Aux_Name : Unit_Name_Type;
6909 Unum : Unit_Number_Type;
6914 function Find_System (C_Unit : Node_Id) return Entity_Id;
6915 -- Scan context clause of compilation unit to find with_clause
6922 function Find_System (C_Unit : Node_Id) return Entity_Id is
6923 With_Clause : Node_Id;
6926 With_Clause := First (Context_Items (C_Unit));
6927 while Present (With_Clause) loop
6928 if (Nkind (With_Clause) = N_With_Clause
6929 and then Chars (Name (With_Clause)) = Name_System)
6930 and then Comes_From_Source (With_Clause)
6941 -- Start of processing for Present_System_Aux
6944 -- The child unit may have been loaded and analyzed already
6946 if Present (System_Aux_Id) then
6949 -- If no previous pragma for System.Aux, nothing to load
6951 elsif No (System_Extend_Unit) then
6954 -- Use the unit name given in the pragma to retrieve the unit.
6955 -- Verify that System itself appears in the context clause of the
6956 -- current compilation. If System is not present, an error will
6957 -- have been reported already.
6960 With_Sys := Find_System (Cunit (Current_Sem_Unit));
6962 The_Unit := Unit (Cunit (Current_Sem_Unit));
6966 (Nkind (The_Unit) = N_Package_Body
6967 or else (Nkind (The_Unit) = N_Subprogram_Body
6969 not Acts_As_Spec (Cunit (Current_Sem_Unit))))
6971 With_Sys := Find_System (Library_Unit (Cunit (Current_Sem_Unit)));
6975 and then Present (N)
6977 -- If we are compiling a subunit, we need to examine its
6978 -- context as well (Current_Sem_Unit is the parent unit);
6980 The_Unit := Parent (N);
6981 while Nkind (The_Unit) /= N_Compilation_Unit loop
6982 The_Unit := Parent (The_Unit);
6985 if Nkind (Unit (The_Unit)) = N_Subunit then
6986 With_Sys := Find_System (The_Unit);
6990 if No (With_Sys) then
6994 Loc := Sloc (With_Sys);
6995 Get_Name_String (Chars (Expression (System_Extend_Unit)));
6996 Name_Buffer (8 .. Name_Len + 7) := Name_Buffer (1 .. Name_Len);
6997 Name_Buffer (1 .. 7) := "system.";
6998 Name_Buffer (Name_Len + 8) := '%';
6999 Name_Buffer (Name_Len + 9) := 's';
7000 Name_Len := Name_Len + 9;
7001 Aux_Name := Name_Find;
7005 (Load_Name => Aux_Name,
7008 Error_Node => With_Sys);
7010 if Unum /= No_Unit then
7011 Semantics (Cunit (Unum));
7013 Defining_Entity (Specification (Unit (Cunit (Unum))));
7016 Make_With_Clause (Loc,
7018 Make_Expanded_Name (Loc,
7019 Chars => Chars (System_Aux_Id),
7020 Prefix => New_Reference_To (Scope (System_Aux_Id), Loc),
7021 Selector_Name => New_Reference_To (System_Aux_Id, Loc)));
7023 Set_Entity (Name (Withn), System_Aux_Id);
7025 Set_Library_Unit (Withn, Cunit (Unum));
7026 Set_Corresponding_Spec (Withn, System_Aux_Id);
7027 Set_First_Name (Withn, True);
7028 Set_Implicit_With (Withn, True);
7030 Insert_After (With_Sys, Withn);
7031 Mark_Rewrite_Insertion (Withn);
7032 Set_Context_Installed (Withn);
7036 -- Here if unit load failed
7039 Error_Msg_Name_1 := Name_System;
7040 Error_Msg_Name_2 := Chars (Expression (System_Extend_Unit));
7042 ("extension package `%.%` does not exist",
7043 Opt.System_Extend_Unit);
7047 end Present_System_Aux;
7049 -------------------------
7050 -- Restore_Scope_Stack --
7051 -------------------------
7053 procedure Restore_Scope_Stack (Handle_Use : Boolean := True) is
7056 Comp_Unit : Node_Id;
7057 In_Child : Boolean := False;
7058 Full_Vis : Boolean := True;
7059 SS_Last : constant Int := Scope_Stack.Last;
7062 -- Restore visibility of previous scope stack, if any
7064 for J in reverse 0 .. Scope_Stack.Last loop
7065 exit when Scope_Stack.Table (J).Entity = Standard_Standard
7066 or else No (Scope_Stack.Table (J).Entity);
7068 S := Scope_Stack.Table (J).Entity;
7070 if not Is_Hidden_Open_Scope (S) then
7072 -- If the parent scope is hidden, its entities are hidden as
7073 -- well, unless the entity is the instantiation currently
7076 if not Is_Hidden_Open_Scope (Scope (S))
7077 or else not Analyzed (Parent (S))
7078 or else Scope (S) = Standard_Standard
7080 Set_Is_Immediately_Visible (S, True);
7083 E := First_Entity (S);
7084 while Present (E) loop
7085 if Is_Child_Unit (E) then
7086 if not From_With_Type (E) then
7087 Set_Is_Immediately_Visible (E,
7088 Is_Visible_Child_Unit (E) or else In_Open_Scopes (E));
7092 (Nkind (Parent (E)) = N_Defining_Program_Unit_Name
7094 Nkind (Parent (Parent (E))) = N_Package_Specification);
7095 Set_Is_Immediately_Visible (E,
7096 Limited_View_Installed (Parent (Parent (E))));
7099 Set_Is_Immediately_Visible (E, True);
7105 and then Is_Package_Or_Generic_Package (S)
7107 -- We are in the visible part of the package scope
7109 exit when E = First_Private_Entity (S);
7113 -- The visibility of child units (siblings of current compilation)
7114 -- must be restored in any case. Their declarations may appear
7115 -- after the private part of the parent.
7117 if not Full_Vis then
7118 while Present (E) loop
7119 if Is_Child_Unit (E) then
7120 Set_Is_Immediately_Visible (E,
7121 Is_Visible_Child_Unit (E) or else In_Open_Scopes (E));
7129 if Is_Child_Unit (S)
7130 and not In_Child -- check only for current unit
7134 -- Restore visibility of parents according to whether the child
7135 -- is private and whether we are in its visible part.
7137 Comp_Unit := Parent (Unit_Declaration_Node (S));
7139 if Nkind (Comp_Unit) = N_Compilation_Unit
7140 and then Private_Present (Comp_Unit)
7144 elsif Is_Package_Or_Generic_Package (S)
7145 and then (In_Private_Part (S) or else In_Package_Body (S))
7149 -- if S is the scope of some instance (which has already been
7150 -- seen on the stack) it does not affect the visibility of
7153 elsif Is_Hidden_Open_Scope (S) then
7156 elsif (Ekind (S) = E_Procedure
7157 or else Ekind (S) = E_Function)
7158 and then Has_Completion (S)
7169 if SS_Last >= Scope_Stack.First
7170 and then Scope_Stack.Table (SS_Last).Entity /= Standard_Standard
7173 Install_Use_Clauses (Scope_Stack.Table (SS_Last).First_Use_Clause);
7175 end Restore_Scope_Stack;
7177 ----------------------
7178 -- Save_Scope_Stack --
7179 ----------------------
7181 procedure Save_Scope_Stack (Handle_Use : Boolean := True) is
7184 SS_Last : constant Int := Scope_Stack.Last;
7187 if SS_Last >= Scope_Stack.First
7188 and then Scope_Stack.Table (SS_Last).Entity /= Standard_Standard
7191 End_Use_Clauses (Scope_Stack.Table (SS_Last).First_Use_Clause);
7194 -- If the call is from within a compilation unit, as when called from
7195 -- Rtsfind, make current entries in scope stack invisible while we
7196 -- analyze the new unit.
7198 for J in reverse 0 .. SS_Last loop
7199 exit when Scope_Stack.Table (J).Entity = Standard_Standard
7200 or else No (Scope_Stack.Table (J).Entity);
7202 S := Scope_Stack.Table (J).Entity;
7203 Set_Is_Immediately_Visible (S, False);
7205 E := First_Entity (S);
7206 while Present (E) loop
7207 Set_Is_Immediately_Visible (E, False);
7213 end Save_Scope_Stack;
7219 procedure Set_Use (L : List_Id) is
7221 Pack_Name : Node_Id;
7228 while Present (Decl) loop
7229 if Nkind (Decl) = N_Use_Package_Clause then
7230 Chain_Use_Clause (Decl);
7232 Pack_Name := First (Names (Decl));
7233 while Present (Pack_Name) loop
7234 Pack := Entity (Pack_Name);
7236 if Ekind (Pack) = E_Package
7237 and then Applicable_Use (Pack_Name)
7239 Use_One_Package (Pack, Decl);
7245 elsif Nkind (Decl) = N_Use_Type_Clause then
7246 Chain_Use_Clause (Decl);
7248 Id := First (Subtype_Marks (Decl));
7249 while Present (Id) loop
7250 if Entity (Id) /= Any_Type then
7263 ---------------------
7264 -- Use_One_Package --
7265 ---------------------
7267 procedure Use_One_Package (P : Entity_Id; N : Node_Id) is
7270 Current_Instance : Entity_Id := Empty;
7272 Private_With_OK : Boolean := False;
7275 if Ekind (P) /= E_Package then
7280 Set_Current_Use_Clause (P, N);
7282 -- Ada 2005 (AI-50217): Check restriction
7284 if From_With_Type (P) then
7285 Error_Msg_N ("limited withed package cannot appear in use clause", N);
7288 -- Find enclosing instance, if any
7291 Current_Instance := Current_Scope;
7292 while not Is_Generic_Instance (Current_Instance) loop
7293 Current_Instance := Scope (Current_Instance);
7296 if No (Hidden_By_Use_Clause (N)) then
7297 Set_Hidden_By_Use_Clause (N, New_Elmt_List);
7301 -- If unit is a package renaming, indicate that the renamed
7302 -- package is also in use (the flags on both entities must
7303 -- remain consistent, and a subsequent use of either of them
7304 -- should be recognized as redundant).
7306 if Present (Renamed_Object (P)) then
7307 Set_In_Use (Renamed_Object (P));
7308 Set_Current_Use_Clause (Renamed_Object (P), N);
7309 Real_P := Renamed_Object (P);
7314 -- Ada 2005 (AI-262): Check the use_clause of a private withed package
7315 -- found in the private part of a package specification
7317 if In_Private_Part (Current_Scope)
7318 and then Has_Private_With (P)
7319 and then Is_Child_Unit (Current_Scope)
7320 and then Is_Child_Unit (P)
7321 and then Is_Ancestor_Package (Scope (Current_Scope), P)
7323 Private_With_OK := True;
7326 -- Loop through entities in one package making them potentially
7329 Id := First_Entity (P);
7331 and then (Id /= First_Private_Entity (P)
7332 or else Private_With_OK) -- Ada 2005 (AI-262)
7334 Prev := Current_Entity (Id);
7335 while Present (Prev) loop
7336 if Is_Immediately_Visible (Prev)
7337 and then (not Is_Overloadable (Prev)
7338 or else not Is_Overloadable (Id)
7339 or else (Type_Conformant (Id, Prev)))
7341 if No (Current_Instance) then
7343 -- Potentially use-visible entity remains hidden
7345 goto Next_Usable_Entity;
7347 -- A use clause within an instance hides outer global entities,
7348 -- which are not used to resolve local entities in the
7349 -- instance. Note that the predefined entities in Standard
7350 -- could not have been hidden in the generic by a use clause,
7351 -- and therefore remain visible. Other compilation units whose
7352 -- entities appear in Standard must be hidden in an instance.
7354 -- To determine whether an entity is external to the instance
7355 -- we compare the scope depth of its scope with that of the
7356 -- current instance. However, a generic actual of a subprogram
7357 -- instance is declared in the wrapper package but will not be
7358 -- hidden by a use-visible entity. similarly, an entity that is
7359 -- declared in an enclosing instance will not be hidden by an
7360 -- an entity declared in a generic actual, which can only have
7361 -- been use-visible in the generic and will not have hidden the
7362 -- entity in the generic parent.
7364 -- If Id is called Standard, the predefined package with the
7365 -- same name is in the homonym chain. It has to be ignored
7366 -- because it has no defined scope (being the only entity in
7367 -- the system with this mandated behavior).
7369 elsif not Is_Hidden (Id)
7370 and then Present (Scope (Prev))
7371 and then not Is_Wrapper_Package (Scope (Prev))
7372 and then Scope_Depth (Scope (Prev)) <
7373 Scope_Depth (Current_Instance)
7374 and then (Scope (Prev) /= Standard_Standard
7375 or else Sloc (Prev) > Standard_Location)
7377 if In_Open_Scopes (Scope (Prev))
7378 and then Is_Generic_Instance (Scope (Prev))
7379 and then Present (Associated_Formal_Package (P))
7384 Set_Is_Potentially_Use_Visible (Id);
7385 Set_Is_Immediately_Visible (Prev, False);
7386 Append_Elmt (Prev, Hidden_By_Use_Clause (N));
7390 -- A user-defined operator is not use-visible if the predefined
7391 -- operator for the type is immediately visible, which is the case
7392 -- if the type of the operand is in an open scope. This does not
7393 -- apply to user-defined operators that have operands of different
7394 -- types, because the predefined mixed mode operations (multiply
7395 -- and divide) apply to universal types and do not hide anything.
7397 elsif Ekind (Prev) = E_Operator
7398 and then Operator_Matches_Spec (Prev, Id)
7399 and then In_Open_Scopes
7400 (Scope (Base_Type (Etype (First_Formal (Id)))))
7401 and then (No (Next_Formal (First_Formal (Id)))
7402 or else Etype (First_Formal (Id))
7403 = Etype (Next_Formal (First_Formal (Id)))
7404 or else Chars (Prev) = Name_Op_Expon)
7406 goto Next_Usable_Entity;
7408 -- In an instance, two homonyms may become use_visible through the
7409 -- actuals of distinct formal packages. In the generic, only the
7410 -- current one would have been visible, so make the other one
7413 elsif Present (Current_Instance)
7414 and then Is_Potentially_Use_Visible (Prev)
7415 and then not Is_Overloadable (Prev)
7416 and then Scope (Id) /= Scope (Prev)
7417 and then Used_As_Generic_Actual (Scope (Prev))
7418 and then Used_As_Generic_Actual (Scope (Id))
7419 and then not In_Same_List (Current_Use_Clause (Scope (Prev)),
7420 Current_Use_Clause (Scope (Id)))
7422 Set_Is_Potentially_Use_Visible (Prev, False);
7423 Append_Elmt (Prev, Hidden_By_Use_Clause (N));
7426 Prev := Homonym (Prev);
7429 -- On exit, we know entity is not hidden, unless it is private
7431 if not Is_Hidden (Id)
7432 and then ((not Is_Child_Unit (Id))
7433 or else Is_Visible_Child_Unit (Id))
7435 Set_Is_Potentially_Use_Visible (Id);
7437 if Is_Private_Type (Id)
7438 and then Present (Full_View (Id))
7440 Set_Is_Potentially_Use_Visible (Full_View (Id));
7444 <<Next_Usable_Entity>>
7448 -- Child units are also made use-visible by a use clause, but they may
7449 -- appear after all visible declarations in the parent entity list.
7451 while Present (Id) loop
7452 if Is_Child_Unit (Id)
7453 and then Is_Visible_Child_Unit (Id)
7455 Set_Is_Potentially_Use_Visible (Id);
7461 if Chars (Real_P) = Name_System
7462 and then Scope (Real_P) = Standard_Standard
7463 and then Present_System_Aux (N)
7465 Use_One_Package (System_Aux_Id, N);
7468 end Use_One_Package;
7474 procedure Use_One_Type (Id : Node_Id) is
7476 Is_Known_Used : Boolean;
7480 function Spec_Reloaded_For_Body return Boolean;
7481 -- Determine whether the compilation unit is a package body and the use
7482 -- type clause is in the spec of the same package. Even though the spec
7483 -- was analyzed first, its context is reloaded when analysing the body.
7485 ----------------------------
7486 -- Spec_Reloaded_For_Body --
7487 ----------------------------
7489 function Spec_Reloaded_For_Body return Boolean is
7491 if Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Body then
7493 Spec : constant Node_Id :=
7494 Parent (List_Containing (Parent (Id)));
7497 Nkind (Spec) = N_Package_Specification
7498 and then Corresponding_Body (Parent (Spec)) =
7499 Cunit_Entity (Current_Sem_Unit);
7504 end Spec_Reloaded_For_Body;
7506 -- Start of processing for Use_One_Type;
7509 -- It is the type determined by the subtype mark (8.4(8)) whose
7510 -- operations become potentially use-visible.
7512 T := Base_Type (Entity (Id));
7514 -- Either the type itself is used, the package where it is declared
7515 -- is in use or the entity is declared in the current package, thus
7520 or else In_Use (Scope (T))
7521 or else Scope (T) = Current_Scope;
7523 Set_Redundant_Use (Id,
7524 Is_Known_Used or else Is_Potentially_Use_Visible (T));
7526 if Ekind (T) = E_Incomplete_Type then
7527 Error_Msg_N ("premature usage of incomplete type", Id);
7529 elsif In_Open_Scopes (Scope (T)) then
7532 -- A limited view cannot appear in a use_type clause. However, an access
7533 -- type whose designated type is limited has the flag but is not itself
7534 -- a limited view unless we only have a limited view of its enclosing
7537 elsif From_With_Type (T)
7538 and then From_With_Type (Scope (T))
7541 ("incomplete type from limited view "
7542 & "cannot appear in use clause", Id);
7544 -- If the subtype mark designates a subtype in a different package,
7545 -- we have to check that the parent type is visible, otherwise the
7546 -- use type clause is a noop. Not clear how to do that???
7548 elsif not Redundant_Use (Id) then
7551 -- If T is tagged, primitive operators on class-wide operands
7552 -- are also available.
7554 if Is_Tagged_Type (T) then
7555 Set_In_Use (Class_Wide_Type (T));
7558 Set_Current_Use_Clause (T, Parent (Id));
7559 Op_List := Collect_Primitive_Operations (T);
7561 Elmt := First_Elmt (Op_List);
7562 while Present (Elmt) loop
7563 if (Nkind (Node (Elmt)) = N_Defining_Operator_Symbol
7564 or else Chars (Node (Elmt)) in Any_Operator_Name)
7565 and then not Is_Hidden (Node (Elmt))
7567 Set_Is_Potentially_Use_Visible (Node (Elmt));
7574 -- If warning on redundant constructs, check for unnecessary WITH
7576 if Warn_On_Redundant_Constructs
7577 and then Is_Known_Used
7579 -- with P; with P; use P;
7580 -- package P is package X is package body X is
7581 -- type T ... use P.T;
7583 -- The compilation unit is the body of X. GNAT first compiles the
7584 -- spec of X, then proceeds to the body. At that point P is marked
7585 -- as use visible. The analysis then reinstalls the spec along with
7586 -- its context. The use clause P.T is now recognized as redundant,
7587 -- but in the wrong context. Do not emit a warning in such cases.
7588 -- Do not emit a warning either if we are in an instance, there is
7589 -- no redundancy between an outer use_clause and one that appears
7590 -- within the generic.
7592 and then not Spec_Reloaded_For_Body
7593 and then not In_Instance
7595 -- The type already has a use clause
7599 -- Case where we know the current use clause for the type
7601 if Present (Current_Use_Clause (T)) then
7602 Use_Clause_Known : declare
7603 Clause1 : constant Node_Id := Parent (Id);
7604 Clause2 : constant Node_Id := Current_Use_Clause (T);
7611 function Entity_Of_Unit (U : Node_Id) return Entity_Id;
7612 -- Return the appropriate entity for determining which unit
7613 -- has a deeper scope: the defining entity for U, unless U
7614 -- is a package instance, in which case we retrieve the
7615 -- entity of the instance spec.
7617 --------------------
7618 -- Entity_Of_Unit --
7619 --------------------
7621 function Entity_Of_Unit (U : Node_Id) return Entity_Id is
7623 if Nkind (U) = N_Package_Instantiation
7624 and then Analyzed (U)
7626 return Defining_Entity (Instance_Spec (U));
7628 return Defining_Entity (U);
7632 -- Start of processing for Use_Clause_Known
7635 -- If both current use type clause and the use type clause
7636 -- for the type are at the compilation unit level, one of
7637 -- the units must be an ancestor of the other, and the
7638 -- warning belongs on the descendant.
7640 if Nkind (Parent (Clause1)) = N_Compilation_Unit
7642 Nkind (Parent (Clause2)) = N_Compilation_Unit
7645 -- If the unit is a subprogram body that acts as spec,
7646 -- the context clause is shared with the constructed
7647 -- subprogram spec. Clearly there is no redundancy.
7649 if Clause1 = Clause2 then
7653 Unit1 := Unit (Parent (Clause1));
7654 Unit2 := Unit (Parent (Clause2));
7656 -- If both clauses are on same unit, or one is the body
7657 -- of the other, or one of them is in a subunit, report
7658 -- redundancy on the later one.
7660 if Unit1 = Unit2 then
7661 Error_Msg_Sloc := Sloc (Current_Use_Clause (T));
7662 Error_Msg_NE -- CODEFIX
7663 ("& is already use-visible through previous "
7664 & "use_type_clause #?", Clause1, T);
7667 elsif Nkind (Unit1) = N_Subunit then
7668 Error_Msg_Sloc := Sloc (Current_Use_Clause (T));
7669 Error_Msg_NE -- CODEFIX
7670 ("& is already use-visible through previous "
7671 & "use_type_clause #?", Clause1, T);
7674 elsif Nkind_In (Unit2, N_Package_Body, N_Subprogram_Body)
7675 and then Nkind (Unit1) /= Nkind (Unit2)
7676 and then Nkind (Unit1) /= N_Subunit
7678 Error_Msg_Sloc := Sloc (Clause1);
7679 Error_Msg_NE -- CODEFIX
7680 ("& is already use-visible through previous "
7681 & "use_type_clause #?", Current_Use_Clause (T), T);
7685 -- There is a redundant use type clause in a child unit.
7686 -- Determine which of the units is more deeply nested.
7687 -- If a unit is a package instance, retrieve the entity
7688 -- and its scope from the instance spec.
7690 Ent1 := Entity_Of_Unit (Unit1);
7691 Ent2 := Entity_Of_Unit (Unit2);
7693 if Scope (Ent2) = Standard_Standard then
7694 Error_Msg_Sloc := Sloc (Current_Use_Clause (T));
7697 elsif Scope (Ent1) = Standard_Standard then
7698 Error_Msg_Sloc := Sloc (Id);
7701 -- If both units are child units, we determine which one
7702 -- is the descendant by the scope distance to the
7703 -- ultimate parent unit.
7713 and then Present (S2)
7714 and then S1 /= Standard_Standard
7715 and then S2 /= Standard_Standard
7721 if S1 = Standard_Standard then
7722 Error_Msg_Sloc := Sloc (Id);
7725 Error_Msg_Sloc := Sloc (Current_Use_Clause (T));
7731 Error_Msg_NE -- CODEFIX
7732 ("& is already use-visible through previous "
7733 & "use_type_clause #?", Err_No, Id);
7735 -- Case where current use type clause and the use type
7736 -- clause for the type are not both at the compilation unit
7737 -- level. In this case we don't have location information.
7740 Error_Msg_NE -- CODEFIX
7741 ("& is already use-visible through previous "
7742 & "use type clause?", Id, T);
7744 end Use_Clause_Known;
7746 -- Here if Current_Use_Clause is not set for T, another case
7747 -- where we do not have the location information available.
7750 Error_Msg_NE -- CODEFIX
7751 ("& is already use-visible through previous "
7752 & "use type clause?", Id, T);
7755 -- The package where T is declared is already used
7757 elsif In_Use (Scope (T)) then
7758 Error_Msg_Sloc := Sloc (Current_Use_Clause (Scope (T)));
7759 Error_Msg_NE -- CODEFIX
7760 ("& is already use-visible through package use clause #?",
7763 -- The current scope is the package where T is declared
7766 Error_Msg_Node_2 := Scope (T);
7767 Error_Msg_NE -- CODEFIX
7768 ("& is already use-visible inside package &?", Id, T);
7777 procedure Write_Info is
7778 Id : Entity_Id := First_Entity (Current_Scope);
7781 -- No point in dumping standard entities
7783 if Current_Scope = Standard_Standard then
7787 Write_Str ("========================================================");
7789 Write_Str (" Defined Entities in ");
7790 Write_Name (Chars (Current_Scope));
7792 Write_Str ("========================================================");
7796 Write_Str ("-- none --");
7800 while Present (Id) loop
7801 Write_Entity_Info (Id, " ");
7806 if Scope (Current_Scope) = Standard_Standard then
7808 -- Print information on the current unit itself
7810 Write_Entity_Info (Current_Scope, " ");
7823 for J in reverse 1 .. Scope_Stack.Last loop
7824 S := Scope_Stack.Table (J).Entity;
7825 Write_Int (Int (S));
7826 Write_Str (" === ");
7827 Write_Name (Chars (S));
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