1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2011, 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 possible
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 known to be an 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; Installed : Boolean := False);
510 -- Id is the subtype mark from a use type clause. This procedure makes
511 -- the primitive operators of the type potentially use-visible. The
512 -- boolean flag Installed indicates that the clause is being reinstalled
513 -- after previous analysis, and primitive operations are already chained
514 -- on the Used_Operations list of the clause.
516 procedure Write_Info;
517 -- Write debugging information on entities declared in current scope
519 --------------------------------
520 -- Analyze_Exception_Renaming --
521 --------------------------------
523 -- The language only allows a single identifier, but the tree holds an
524 -- identifier list. The parser has already issued an error message if
525 -- there is more than one element in the list.
527 procedure Analyze_Exception_Renaming (N : Node_Id) is
528 Id : constant Node_Id := Defining_Identifier (N);
529 Nam : constant Node_Id := Name (N);
532 Check_SPARK_Restriction ("exception renaming is not allowed", N);
537 Set_Ekind (Id, E_Exception);
538 Set_Exception_Code (Id, Uint_0);
539 Set_Etype (Id, Standard_Exception_Type);
540 Set_Is_Pure (Id, Is_Pure (Current_Scope));
542 if not Is_Entity_Name (Nam) or else
543 Ekind (Entity (Nam)) /= E_Exception
545 Error_Msg_N ("invalid exception name in renaming", Nam);
547 if Present (Renamed_Object (Entity (Nam))) then
548 Set_Renamed_Object (Id, Renamed_Object (Entity (Nam)));
550 Set_Renamed_Object (Id, Entity (Nam));
553 end Analyze_Exception_Renaming;
555 ---------------------------
556 -- Analyze_Expanded_Name --
557 ---------------------------
559 procedure Analyze_Expanded_Name (N : Node_Id) is
561 -- If the entity pointer is already set, this is an internal node, or a
562 -- node that is analyzed more than once, after a tree modification. In
563 -- such a case there is no resolution to perform, just set the type. For
564 -- completeness, analyze prefix as well.
566 if Present (Entity (N)) then
567 if Is_Type (Entity (N)) then
568 Set_Etype (N, Entity (N));
570 Set_Etype (N, Etype (Entity (N)));
573 Analyze (Prefix (N));
576 Find_Expanded_Name (N);
578 end Analyze_Expanded_Name;
580 ---------------------------------------
581 -- Analyze_Generic_Function_Renaming --
582 ---------------------------------------
584 procedure Analyze_Generic_Function_Renaming (N : Node_Id) is
586 Analyze_Generic_Renaming (N, E_Generic_Function);
587 end Analyze_Generic_Function_Renaming;
589 --------------------------------------
590 -- Analyze_Generic_Package_Renaming --
591 --------------------------------------
593 procedure Analyze_Generic_Package_Renaming (N : Node_Id) is
595 -- Apply the Text_IO Kludge here, since we may be renaming one of the
596 -- subpackages of Text_IO, then join common routine.
598 Text_IO_Kludge (Name (N));
600 Analyze_Generic_Renaming (N, E_Generic_Package);
601 end Analyze_Generic_Package_Renaming;
603 ----------------------------------------
604 -- Analyze_Generic_Procedure_Renaming --
605 ----------------------------------------
607 procedure Analyze_Generic_Procedure_Renaming (N : Node_Id) is
609 Analyze_Generic_Renaming (N, E_Generic_Procedure);
610 end Analyze_Generic_Procedure_Renaming;
612 ------------------------------
613 -- Analyze_Generic_Renaming --
614 ------------------------------
616 procedure Analyze_Generic_Renaming
620 New_P : constant Entity_Id := Defining_Entity (N);
622 Inst : Boolean := False; -- prevent junk warning
625 if Name (N) = Error then
629 Check_SPARK_Restriction ("generic renaming is not allowed", N);
631 Generate_Definition (New_P);
633 if Current_Scope /= Standard_Standard then
634 Set_Is_Pure (New_P, Is_Pure (Current_Scope));
637 if Nkind (Name (N)) = N_Selected_Component then
638 Check_Generic_Child_Unit (Name (N), Inst);
643 if not Is_Entity_Name (Name (N)) then
644 Error_Msg_N ("expect entity name in renaming declaration", Name (N));
647 Old_P := Entity (Name (N));
651 Set_Ekind (New_P, K);
653 if Etype (Old_P) = Any_Type then
656 elsif Ekind (Old_P) /= K then
657 Error_Msg_N ("invalid generic unit name", Name (N));
660 if Present (Renamed_Object (Old_P)) then
661 Set_Renamed_Object (New_P, Renamed_Object (Old_P));
663 Set_Renamed_Object (New_P, Old_P);
666 Set_Is_Pure (New_P, Is_Pure (Old_P));
667 Set_Is_Preelaborated (New_P, Is_Preelaborated (Old_P));
669 Set_Etype (New_P, Etype (Old_P));
670 Set_Has_Completion (New_P);
672 if In_Open_Scopes (Old_P) then
673 Error_Msg_N ("within its scope, generic denotes its instance", N);
676 Check_Library_Unit_Renaming (N, Old_P);
678 end Analyze_Generic_Renaming;
680 -----------------------------
681 -- Analyze_Object_Renaming --
682 -----------------------------
684 procedure Analyze_Object_Renaming (N : Node_Id) is
685 Loc : constant Source_Ptr := Sloc (N);
686 Id : constant Entity_Id := Defining_Identifier (N);
688 Nam : constant Node_Id := Name (N);
692 procedure Check_Constrained_Object;
693 -- If the nominal type is unconstrained but the renamed object is
694 -- constrained, as can happen with renaming an explicit dereference or
695 -- a function return, build a constrained subtype from the object. If
696 -- the renaming is for a formal in an accept statement, the analysis
697 -- has already established its actual subtype. This is only relevant
698 -- if the renamed object is an explicit dereference.
700 function In_Generic_Scope (E : Entity_Id) return Boolean;
701 -- Determine whether entity E is inside a generic cope
703 ------------------------------
704 -- Check_Constrained_Object --
705 ------------------------------
707 procedure Check_Constrained_Object is
711 if Nkind_In (Nam, N_Function_Call, N_Explicit_Dereference)
712 and then Is_Composite_Type (Etype (Nam))
713 and then not Is_Constrained (Etype (Nam))
714 and then not Has_Unknown_Discriminants (Etype (Nam))
715 and then Expander_Active
717 -- If Actual_Subtype is already set, nothing to do
719 if Ekind_In (Id, E_Variable, E_Constant)
720 and then Present (Actual_Subtype (Id))
725 Subt := Make_Temporary (Loc, 'T');
726 Remove_Side_Effects (Nam);
728 Make_Subtype_Declaration (Loc,
729 Defining_Identifier => Subt,
730 Subtype_Indication =>
731 Make_Subtype_From_Expr (Nam, Etype (Nam))));
732 Rewrite (Subtype_Mark (N), New_Occurrence_Of (Subt, Loc));
733 Set_Etype (Nam, Subt);
736 end Check_Constrained_Object;
738 ----------------------
739 -- In_Generic_Scope --
740 ----------------------
742 function In_Generic_Scope (E : Entity_Id) return Boolean is
747 while Present (S) and then S /= Standard_Standard loop
748 if Is_Generic_Unit (S) then
756 end In_Generic_Scope;
758 -- Start of processing for Analyze_Object_Renaming
765 Check_SPARK_Restriction ("object renaming is not allowed", N);
767 Set_Is_Pure (Id, Is_Pure (Current_Scope));
770 -- The renaming of a component that depends on a discriminant requires
771 -- an actual subtype, because in subsequent use of the object Gigi will
772 -- be unable to locate the actual bounds. This explicit step is required
773 -- when the renaming is generated in removing side effects of an
774 -- already-analyzed expression.
776 if Nkind (Nam) = N_Selected_Component
777 and then Analyzed (Nam)
780 Dec := Build_Actual_Subtype_Of_Component (Etype (Nam), Nam);
782 if Present (Dec) then
783 Insert_Action (N, Dec);
784 T := Defining_Identifier (Dec);
788 -- Complete analysis of the subtype mark in any case, for ASIS use
790 if Present (Subtype_Mark (N)) then
791 Find_Type (Subtype_Mark (N));
794 elsif Present (Subtype_Mark (N)) then
795 Find_Type (Subtype_Mark (N));
796 T := Entity (Subtype_Mark (N));
799 if Nkind (Nam) = N_Type_Conversion
800 and then not Is_Tagged_Type (T)
803 ("renaming of conversion only allowed for tagged types", Nam);
808 -- If the renamed object is a function call of a limited type,
809 -- the expansion of the renaming is complicated by the presence
810 -- of various temporaries and subtypes that capture constraints
811 -- of the renamed object. Rewrite node as an object declaration,
812 -- whose expansion is simpler. Given that the object is limited
813 -- there is no copy involved and no performance hit.
815 if Nkind (Nam) = N_Function_Call
816 and then Is_Immutably_Limited_Type (Etype (Nam))
817 and then not Is_Constrained (Etype (Nam))
818 and then Comes_From_Source (N)
821 Set_Ekind (Id, E_Constant);
823 Make_Object_Declaration (Loc,
824 Defining_Identifier => Id,
825 Constant_Present => True,
826 Object_Definition => New_Occurrence_Of (Etype (Nam), Loc),
827 Expression => Relocate_Node (Nam)));
831 -- Check that a class-wide object is not being renamed as an object
832 -- of a specific type. The test for access types is needed to exclude
833 -- cases where the renamed object is a dynamically tagged access
834 -- result, such as occurs in certain expansions.
836 if Is_Tagged_Type (T) then
837 Check_Dynamically_Tagged_Expression
843 -- Ada 2005 (AI-230/AI-254): Access renaming
845 else pragma Assert (Present (Access_Definition (N)));
846 T := Access_Definition
848 N => Access_Definition (N));
852 -- Ada 2005 AI05-105: if the declaration has an anonymous access
853 -- type, the renamed object must also have an anonymous type, and
854 -- this is a name resolution rule. This was implicit in the last part
855 -- of the first sentence in 8.5.1(3/2), and is made explicit by this
858 if not Is_Overloaded (Nam) then
859 if Ekind (Etype (Nam)) /= Ekind (T) then
861 ("expect anonymous access type in object renaming", N);
868 Typ : Entity_Id := Empty;
869 Seen : Boolean := False;
872 Get_First_Interp (Nam, I, It);
873 while Present (It.Typ) loop
875 -- Renaming is ambiguous if more than one candidate
876 -- interpretation is type-conformant with the context.
878 if Ekind (It.Typ) = Ekind (T) then
879 if Ekind (T) = E_Anonymous_Access_Subprogram_Type
882 (Designated_Type (T), Designated_Type (It.Typ))
888 ("ambiguous expression in renaming", Nam);
891 elsif Ekind (T) = E_Anonymous_Access_Type
893 Covers (Designated_Type (T), Designated_Type (It.Typ))
899 ("ambiguous expression in renaming", Nam);
903 if Covers (T, It.Typ) then
905 Set_Etype (Nam, Typ);
906 Set_Is_Overloaded (Nam, False);
910 Get_Next_Interp (I, It);
917 -- Ada 2005 (AI-231): "In the case where the type is defined by an
918 -- access_definition, the renamed entity shall be of an access-to-
919 -- constant type if and only if the access_definition defines an
920 -- access-to-constant type" ARM 8.5.1(4)
922 if Constant_Present (Access_Definition (N))
923 and then not Is_Access_Constant (Etype (Nam))
925 Error_Msg_N ("(Ada 2005): the renamed object is not "
926 & "access-to-constant (RM 8.5.1(6))", N);
928 elsif not Constant_Present (Access_Definition (N))
929 and then Is_Access_Constant (Etype (Nam))
931 Error_Msg_N ("(Ada 2005): the renamed object is not "
932 & "access-to-variable (RM 8.5.1(6))", N);
935 if Is_Access_Subprogram_Type (Etype (Nam)) then
936 Check_Subtype_Conformant
937 (Designated_Type (T), Designated_Type (Etype (Nam)));
939 elsif not Subtypes_Statically_Match
940 (Designated_Type (T),
941 Available_View (Designated_Type (Etype (Nam))))
944 ("subtype of renamed object does not statically match", N);
948 -- Special processing for renaming function return object. Some errors
949 -- and warnings are produced only for calls that come from source.
951 if Nkind (Nam) = N_Function_Call then
954 -- Usage is illegal in Ada 83
957 if Comes_From_Source (Nam) then
959 ("(Ada 83) cannot rename function return object", Nam);
962 -- In Ada 95, warn for odd case of renaming parameterless function
963 -- call if this is not a limited type (where this is useful).
966 if Warn_On_Object_Renames_Function
967 and then No (Parameter_Associations (Nam))
968 and then not Is_Limited_Type (Etype (Nam))
969 and then Comes_From_Source (Nam)
972 ("?renaming function result object is suspicious", Nam);
974 ("\?function & will be called only once", Nam,
975 Entity (Name (Nam)));
976 Error_Msg_N -- CODEFIX
977 ("\?suggest using an initialized constant object instead",
984 Check_Constrained_Object;
986 -- An object renaming requires an exact match of the type. Class-wide
987 -- matching is not allowed.
989 if Is_Class_Wide_Type (T)
990 and then Base_Type (Etype (Nam)) /= Base_Type (T)
997 -- Ada 2005 (AI-326): Handle wrong use of incomplete type
999 if Nkind (Nam) = N_Explicit_Dereference
1000 and then Ekind (Etype (T2)) = E_Incomplete_Type
1002 Error_Msg_NE ("invalid use of incomplete type&", Id, T2);
1005 elsif Ekind (Etype (T)) = E_Incomplete_Type then
1006 Error_Msg_NE ("invalid use of incomplete type&", Id, T);
1010 -- Ada 2005 (AI-327)
1012 if Ada_Version >= Ada_2005
1013 and then Nkind (Nam) = N_Attribute_Reference
1014 and then Attribute_Name (Nam) = Name_Priority
1018 elsif Ada_Version >= Ada_2005
1019 and then Nkind (Nam) in N_Has_Entity
1023 Nam_Ent : Entity_Id;
1026 if Nkind (Nam) = N_Attribute_Reference then
1027 Nam_Ent := Entity (Prefix (Nam));
1029 Nam_Ent := Entity (Nam);
1032 Nam_Decl := Parent (Nam_Ent);
1034 if Has_Null_Exclusion (N)
1035 and then not Has_Null_Exclusion (Nam_Decl)
1037 -- Ada 2005 (AI-423): If the object name denotes a generic
1038 -- formal object of a generic unit G, and the object renaming
1039 -- declaration occurs within the body of G or within the body
1040 -- of a generic unit declared within the declarative region
1041 -- of G, then the declaration of the formal object of G must
1042 -- have a null exclusion or a null-excluding subtype.
1044 if Is_Formal_Object (Nam_Ent)
1045 and then In_Generic_Scope (Id)
1047 if not Can_Never_Be_Null (Etype (Nam_Ent)) then
1049 ("renamed formal does not exclude `NULL` "
1050 & "(RM 8.5.1(4.6/2))", N);
1052 elsif In_Package_Body (Scope (Id)) then
1054 ("formal object does not have a null exclusion"
1055 & "(RM 8.5.1(4.6/2))", N);
1058 -- Ada 2005 (AI-423): Otherwise, the subtype of the object name
1059 -- shall exclude null.
1061 elsif not Can_Never_Be_Null (Etype (Nam_Ent)) then
1063 ("renamed object does not exclude `NULL` "
1064 & "(RM 8.5.1(4.6/2))", N);
1066 -- An instance is illegal if it contains a renaming that
1067 -- excludes null, and the actual does not. The renaming
1068 -- declaration has already indicated that the declaration
1069 -- of the renamed actual in the instance will raise
1070 -- constraint_error.
1072 elsif Nkind (Nam_Decl) = N_Object_Declaration
1073 and then In_Instance
1075 (Corresponding_Generic_Association (Nam_Decl))
1076 and then Nkind (Expression (Nam_Decl))
1077 = N_Raise_Constraint_Error
1080 ("renamed actual does not exclude `NULL` "
1081 & "(RM 8.5.1(4.6/2))", N);
1083 -- Finally, if there is a null exclusion, the subtype mark
1084 -- must not be null-excluding.
1086 elsif No (Access_Definition (N))
1087 and then Can_Never_Be_Null (T)
1090 ("`NOT NULL` not allowed (& already excludes null)",
1095 elsif Can_Never_Be_Null (T)
1096 and then not Can_Never_Be_Null (Etype (Nam_Ent))
1099 ("renamed object does not exclude `NULL` "
1100 & "(RM 8.5.1(4.6/2))", N);
1102 elsif Has_Null_Exclusion (N)
1103 and then No (Access_Definition (N))
1104 and then Can_Never_Be_Null (T)
1107 ("`NOT NULL` not allowed (& already excludes null)", N, T);
1112 Set_Ekind (Id, E_Variable);
1113 Init_Size_Align (Id);
1115 if T = Any_Type or else Etype (Nam) = Any_Type then
1118 -- Verify that the renamed entity is an object or a function call. It
1119 -- may have been rewritten in several ways.
1121 elsif Is_Object_Reference (Nam) then
1122 if Comes_From_Source (N)
1123 and then Is_Dependent_Component_Of_Mutable_Object (Nam)
1126 ("illegal renaming of discriminant-dependent component", Nam);
1129 -- A static function call may have been folded into a literal
1131 elsif Nkind (Original_Node (Nam)) = N_Function_Call
1133 -- When expansion is disabled, attribute reference is not
1134 -- rewritten as function call. Otherwise it may be rewritten
1135 -- as a conversion, so check original node.
1137 or else (Nkind (Original_Node (Nam)) = N_Attribute_Reference
1138 and then Is_Function_Attribute_Name
1139 (Attribute_Name (Original_Node (Nam))))
1141 -- Weird but legal, equivalent to renaming a function call.
1142 -- Illegal if the literal is the result of constant-folding an
1143 -- attribute reference that is not a function.
1145 or else (Is_Entity_Name (Nam)
1146 and then Ekind (Entity (Nam)) = E_Enumeration_Literal
1148 Nkind (Original_Node (Nam)) /= N_Attribute_Reference)
1150 or else (Nkind (Nam) = N_Type_Conversion
1151 and then Is_Tagged_Type (Entity (Subtype_Mark (Nam))))
1155 elsif Nkind (Nam) = N_Type_Conversion then
1157 ("renaming of conversion only allowed for tagged types", Nam);
1159 -- Ada 2005 (AI-327)
1161 elsif Ada_Version >= Ada_2005
1162 and then Nkind (Nam) = N_Attribute_Reference
1163 and then Attribute_Name (Nam) = Name_Priority
1167 -- Allow internally generated x'Reference expression
1169 elsif Nkind (Nam) = N_Reference then
1173 Error_Msg_N ("expect object name in renaming", Nam);
1178 if not Is_Variable (Nam) then
1179 Set_Ekind (Id, E_Constant);
1180 Set_Never_Set_In_Source (Id, True);
1181 Set_Is_True_Constant (Id, True);
1184 Set_Renamed_Object (Id, Nam);
1185 end Analyze_Object_Renaming;
1187 ------------------------------
1188 -- Analyze_Package_Renaming --
1189 ------------------------------
1191 procedure Analyze_Package_Renaming (N : Node_Id) is
1192 New_P : constant Entity_Id := Defining_Entity (N);
1197 if Name (N) = Error then
1201 -- Apply Text_IO kludge here since we may be renaming a child of Text_IO
1203 Text_IO_Kludge (Name (N));
1205 if Current_Scope /= Standard_Standard then
1206 Set_Is_Pure (New_P, Is_Pure (Current_Scope));
1212 if Is_Entity_Name (Name (N)) then
1213 Old_P := Entity (Name (N));
1218 if Etype (Old_P) = Any_Type then
1219 Error_Msg_N ("expect package name in renaming", Name (N));
1221 elsif Ekind (Old_P) /= E_Package
1222 and then not (Ekind (Old_P) = E_Generic_Package
1223 and then In_Open_Scopes (Old_P))
1225 if Ekind (Old_P) = E_Generic_Package then
1227 ("generic package cannot be renamed as a package", Name (N));
1229 Error_Msg_Sloc := Sloc (Old_P);
1231 ("expect package name in renaming, found& declared#",
1235 -- Set basic attributes to minimize cascaded errors
1237 Set_Ekind (New_P, E_Package);
1238 Set_Etype (New_P, Standard_Void_Type);
1240 -- Here for OK package renaming
1243 -- Entities in the old package are accessible through the renaming
1244 -- entity. The simplest implementation is to have both packages share
1247 Set_Ekind (New_P, E_Package);
1248 Set_Etype (New_P, Standard_Void_Type);
1250 if Present (Renamed_Object (Old_P)) then
1251 Set_Renamed_Object (New_P, Renamed_Object (Old_P));
1253 Set_Renamed_Object (New_P, Old_P);
1256 Set_Has_Completion (New_P);
1258 Set_First_Entity (New_P, First_Entity (Old_P));
1259 Set_Last_Entity (New_P, Last_Entity (Old_P));
1260 Set_First_Private_Entity (New_P, First_Private_Entity (Old_P));
1261 Check_Library_Unit_Renaming (N, Old_P);
1262 Generate_Reference (Old_P, Name (N));
1264 -- If the renaming is in the visible part of a package, then we set
1265 -- Renamed_In_Spec for the renamed package, to prevent giving
1266 -- warnings about no entities referenced. Such a warning would be
1267 -- overenthusiastic, since clients can see entities in the renamed
1268 -- package via the visible package renaming.
1271 Ent : constant Entity_Id := Cunit_Entity (Current_Sem_Unit);
1273 if Ekind (Ent) = E_Package
1274 and then not In_Private_Part (Ent)
1275 and then In_Extended_Main_Source_Unit (N)
1276 and then Ekind (Old_P) = E_Package
1278 Set_Renamed_In_Spec (Old_P);
1282 -- If this is the renaming declaration of a package instantiation
1283 -- within itself, it is the declaration that ends the list of actuals
1284 -- for the instantiation. At this point, the subtypes that rename
1285 -- the actuals are flagged as generic, to avoid spurious ambiguities
1286 -- if the actuals for two distinct formals happen to coincide. If
1287 -- the actual is a private type, the subtype has a private completion
1288 -- that is flagged in the same fashion.
1290 -- Resolution is identical to what is was in the original generic.
1291 -- On exit from the generic instance, these are turned into regular
1292 -- subtypes again, so they are compatible with types in their class.
1294 if not Is_Generic_Instance (Old_P) then
1297 Spec := Specification (Unit_Declaration_Node (Old_P));
1300 if Nkind (Spec) = N_Package_Specification
1301 and then Present (Generic_Parent (Spec))
1302 and then Old_P = Current_Scope
1303 and then Chars (New_P) = Chars (Generic_Parent (Spec))
1309 E := First_Entity (Old_P);
1314 and then Nkind (Parent (E)) = N_Subtype_Declaration
1316 Set_Is_Generic_Actual_Type (E);
1318 if Is_Private_Type (E)
1319 and then Present (Full_View (E))
1321 Set_Is_Generic_Actual_Type (Full_View (E));
1330 end Analyze_Package_Renaming;
1332 -------------------------------
1333 -- Analyze_Renamed_Character --
1334 -------------------------------
1336 procedure Analyze_Renamed_Character
1341 C : constant Node_Id := Name (N);
1344 if Ekind (New_S) = E_Function then
1345 Resolve (C, Etype (New_S));
1348 Check_Frozen_Renaming (N, New_S);
1352 Error_Msg_N ("character literal can only be renamed as function", N);
1354 end Analyze_Renamed_Character;
1356 ---------------------------------
1357 -- Analyze_Renamed_Dereference --
1358 ---------------------------------
1360 procedure Analyze_Renamed_Dereference
1365 Nam : constant Node_Id := Name (N);
1366 P : constant Node_Id := Prefix (Nam);
1372 if not Is_Overloaded (P) then
1373 if Ekind (Etype (Nam)) /= E_Subprogram_Type
1374 or else not Type_Conformant (Etype (Nam), New_S)
1376 Error_Msg_N ("designated type does not match specification", P);
1385 Get_First_Interp (Nam, Ind, It);
1387 while Present (It.Nam) loop
1389 if Ekind (It.Nam) = E_Subprogram_Type
1390 and then Type_Conformant (It.Nam, New_S)
1392 if Typ /= Any_Id then
1393 Error_Msg_N ("ambiguous renaming", P);
1400 Get_Next_Interp (Ind, It);
1403 if Typ = Any_Type then
1404 Error_Msg_N ("designated type does not match specification", P);
1409 Check_Frozen_Renaming (N, New_S);
1413 end Analyze_Renamed_Dereference;
1415 ---------------------------
1416 -- Analyze_Renamed_Entry --
1417 ---------------------------
1419 procedure Analyze_Renamed_Entry
1424 Nam : constant Node_Id := Name (N);
1425 Sel : constant Node_Id := Selector_Name (Nam);
1429 if Entity (Sel) = Any_Id then
1431 -- Selector is undefined on prefix. Error emitted already
1433 Set_Has_Completion (New_S);
1437 -- Otherwise find renamed entity and build body of New_S as a call to it
1439 Old_S := Find_Renamed_Entity (N, Selector_Name (Nam), New_S);
1441 if Old_S = Any_Id then
1442 Error_Msg_N (" no subprogram or entry matches 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);
1450 -- Only mode conformance required for a renaming_as_declaration
1452 Check_Mode_Conformant (New_S, Old_S, N);
1455 Inherit_Renamed_Profile (New_S, Old_S);
1457 -- The prefix can be an arbitrary expression that yields a task type,
1458 -- so it must be resolved.
1460 Resolve (Prefix (Nam), Scope (Old_S));
1463 Set_Convention (New_S, Convention (Old_S));
1464 Set_Has_Completion (New_S, Inside_A_Generic);
1467 Check_Frozen_Renaming (N, New_S);
1469 end Analyze_Renamed_Entry;
1471 -----------------------------------
1472 -- Analyze_Renamed_Family_Member --
1473 -----------------------------------
1475 procedure Analyze_Renamed_Family_Member
1480 Nam : constant Node_Id := Name (N);
1481 P : constant Node_Id := Prefix (Nam);
1485 if (Is_Entity_Name (P) and then Ekind (Entity (P)) = E_Entry_Family)
1486 or else (Nkind (P) = N_Selected_Component
1488 Ekind (Entity (Selector_Name (P))) = E_Entry_Family)
1490 if Is_Entity_Name (P) then
1491 Old_S := Entity (P);
1493 Old_S := Entity (Selector_Name (P));
1496 if not Entity_Matches_Spec (Old_S, New_S) then
1497 Error_Msg_N ("entry family does not match specification", N);
1500 Check_Subtype_Conformant (New_S, Old_S, N);
1501 Generate_Reference (New_S, Defining_Entity (N), 'b');
1502 Style.Check_Identifier (Defining_Entity (N), New_S);
1506 Error_Msg_N ("no entry family matches specification", N);
1509 Set_Has_Completion (New_S, Inside_A_Generic);
1512 Check_Frozen_Renaming (N, New_S);
1514 end Analyze_Renamed_Family_Member;
1516 -----------------------------------------
1517 -- Analyze_Renamed_Primitive_Operation --
1518 -----------------------------------------
1520 procedure Analyze_Renamed_Primitive_Operation
1529 Ctyp : Conformance_Type) return Boolean;
1530 -- Verify that the signatures of the renamed entity and the new entity
1531 -- match. The first formal of the renamed entity is skipped because it
1532 -- is the target object in any subsequent call.
1536 Ctyp : Conformance_Type) return Boolean
1542 if Ekind (Subp) /= Ekind (New_S) then
1546 Old_F := Next_Formal (First_Formal (Subp));
1547 New_F := First_Formal (New_S);
1548 while Present (Old_F) and then Present (New_F) loop
1549 if not Conforming_Types (Etype (Old_F), Etype (New_F), Ctyp) then
1553 if Ctyp >= Mode_Conformant
1554 and then Ekind (Old_F) /= Ekind (New_F)
1559 Next_Formal (New_F);
1560 Next_Formal (Old_F);
1567 if not Is_Overloaded (Selector_Name (Name (N))) then
1568 Old_S := Entity (Selector_Name (Name (N)));
1570 if not Conforms (Old_S, Type_Conformant) then
1575 -- Find the operation that matches the given signature
1583 Get_First_Interp (Selector_Name (Name (N)), Ind, It);
1585 while Present (It.Nam) loop
1586 if Conforms (It.Nam, Type_Conformant) then
1590 Get_Next_Interp (Ind, It);
1595 if Old_S = Any_Id then
1596 Error_Msg_N (" no subprogram or entry matches specification", N);
1600 if not Conforms (Old_S, Subtype_Conformant) then
1601 Error_Msg_N ("subtype conformance error in renaming", N);
1604 Generate_Reference (New_S, Defining_Entity (N), 'b');
1605 Style.Check_Identifier (Defining_Entity (N), New_S);
1608 -- Only mode conformance required for a renaming_as_declaration
1610 if not Conforms (Old_S, Mode_Conformant) then
1611 Error_Msg_N ("mode conformance error in renaming", N);
1615 -- Inherit_Renamed_Profile (New_S, Old_S);
1617 -- The prefix can be an arbitrary expression that yields an
1618 -- object, so it must be resolved.
1620 Resolve (Prefix (Name (N)));
1622 end Analyze_Renamed_Primitive_Operation;
1624 ---------------------------------
1625 -- Analyze_Subprogram_Renaming --
1626 ---------------------------------
1628 procedure Analyze_Subprogram_Renaming (N : Node_Id) is
1629 Formal_Spec : constant Node_Id := Corresponding_Formal_Spec (N);
1630 Is_Actual : constant Boolean := Present (Formal_Spec);
1632 CW_Actual : Boolean := False;
1633 -- True if the renaming is for a defaulted formal subprogram when the
1634 -- actual for a related formal type is class-wide. For AI05-0071.
1636 Inst_Node : Node_Id := Empty;
1637 Nam : constant Node_Id := Name (N);
1639 Old_S : Entity_Id := Empty;
1640 Rename_Spec : Entity_Id;
1641 Save_AV : constant Ada_Version_Type := Ada_Version;
1642 Save_AV_Exp : constant Ada_Version_Type := Ada_Version_Explicit;
1643 Spec : constant Node_Id := Specification (N);
1645 procedure Check_Null_Exclusion
1648 -- Ada 2005 (AI-423): Given renaming Ren of subprogram Sub, check the
1649 -- following AI rules:
1651 -- If Ren is a renaming of a formal subprogram and one of its
1652 -- parameters has a null exclusion, then the corresponding formal
1653 -- in Sub must also have one. Otherwise the subtype of the Sub's
1654 -- formal parameter must exclude null.
1656 -- If Ren is a renaming of a formal function and its return
1657 -- profile has a null exclusion, then Sub's return profile must
1658 -- have one. Otherwise the subtype of Sub's return profile must
1661 function Original_Subprogram (Subp : Entity_Id) return Entity_Id;
1662 -- Find renamed entity when the declaration is a renaming_as_body and
1663 -- the renamed entity may itself be a renaming_as_body. Used to enforce
1664 -- rule that a renaming_as_body is illegal if the declaration occurs
1665 -- before the subprogram it completes is frozen, and renaming indirectly
1666 -- renames the subprogram itself.(Defect Report 8652/0027).
1668 function Check_Class_Wide_Actual return Entity_Id;
1669 -- AI05-0071: In an instance, if the actual for a formal type FT with
1670 -- unknown discriminants is a class-wide type CT, and the generic has
1671 -- a formal subprogram with a box for a primitive operation of FT,
1672 -- then the corresponding actual subprogram denoted by the default is a
1673 -- class-wide operation whose body is a dispatching call. We replace the
1674 -- generated renaming declaration:
1676 -- procedure P (X : CT) renames P;
1678 -- by a different renaming and a class-wide operation:
1680 -- procedure Pr (X : T) renames P; -- renames primitive operation
1681 -- procedure P (X : CT); -- class-wide operation
1683 -- procedure P (X : CT) is begin Pr (X); end; -- dispatching call
1685 -- This rule only applies if there is no explicit visible class-wide
1686 -- operation at the point of the instantiation.
1688 -----------------------------
1689 -- Check_Class_Wide_Actual --
1690 -----------------------------
1692 function Check_Class_Wide_Actual return Entity_Id is
1693 Loc : constant Source_Ptr := Sloc (N);
1696 Formal_Type : Entity_Id;
1697 Actual_Type : Entity_Id;
1702 function Make_Call (Prim_Op : Entity_Id) return Node_Id;
1703 -- Build dispatching call for body of class-wide operation
1705 function Make_Spec return Node_Id;
1706 -- Create subprogram specification for declaration and body of
1707 -- class-wide operation, using signature of renaming declaration.
1713 function Make_Call (Prim_Op : Entity_Id) return Node_Id is
1718 Actuals := New_List;
1719 F := First (Parameter_Specifications (Specification (New_Decl)));
1720 while Present (F) loop
1722 Make_Identifier (Loc, Chars (Defining_Identifier (F))));
1726 if Ekind (Prim_Op) = E_Function then
1727 return Make_Simple_Return_Statement (Loc,
1729 Make_Function_Call (Loc,
1730 Name => New_Occurrence_Of (Prim_Op, Loc),
1731 Parameter_Associations => Actuals));
1734 Make_Procedure_Call_Statement (Loc,
1735 Name => New_Occurrence_Of (Prim_Op, Loc),
1736 Parameter_Associations => Actuals);
1744 function Make_Spec return Node_Id is
1745 Param_Specs : constant List_Id := Copy_Parameter_List (New_S);
1748 if Ekind (New_S) = E_Procedure then
1750 Make_Procedure_Specification (Loc,
1751 Defining_Unit_Name =>
1752 Make_Defining_Identifier (Loc,
1753 Chars (Defining_Unit_Name (Spec))),
1754 Parameter_Specifications => Param_Specs);
1757 Make_Function_Specification (Loc,
1758 Defining_Unit_Name =>
1759 Make_Defining_Identifier (Loc,
1760 Chars (Defining_Unit_Name (Spec))),
1761 Parameter_Specifications => Param_Specs,
1762 Result_Definition =>
1763 New_Copy_Tree (Result_Definition (Spec)));
1767 -- Start of processing for Check_Class_Wide_Actual
1771 Formal_Type := Empty;
1772 Actual_Type := Empty;
1774 F := First_Formal (Formal_Spec);
1775 while Present (F) loop
1776 if Has_Unknown_Discriminants (Etype (F))
1777 and then Is_Class_Wide_Type (Get_Instance_Of (Etype (F)))
1779 Formal_Type := Etype (F);
1780 Actual_Type := Etype (Get_Instance_Of (Formal_Type));
1787 if Present (Formal_Type) then
1790 -- Create declaration and body for class-wide operation
1793 Make_Subprogram_Declaration (Loc, Specification => Make_Spec);
1796 Make_Subprogram_Body (Loc,
1797 Specification => Make_Spec,
1798 Declarations => No_List,
1799 Handled_Statement_Sequence =>
1800 Make_Handled_Sequence_Of_Statements (Loc, New_List));
1802 -- Modify Spec and create internal name for renaming of primitive
1805 Set_Defining_Unit_Name (Spec, Make_Temporary (Loc, 'R'));
1806 F := First (Parameter_Specifications (Spec));
1807 while Present (F) loop
1808 if Nkind (Parameter_Type (F)) = N_Identifier
1809 and then Is_Class_Wide_Type (Entity (Parameter_Type (F)))
1811 Set_Parameter_Type (F, New_Occurrence_Of (Actual_Type, Loc));
1816 New_S := Analyze_Subprogram_Specification (Spec);
1817 Result := Find_Renamed_Entity (N, Name (N), New_S, Is_Actual);
1820 if Result /= Any_Id then
1821 Insert_Before (N, New_Decl);
1824 -- Add dispatching call to body of class-wide operation
1826 Append (Make_Call (Result),
1827 Statements (Handled_Statement_Sequence (New_Body)));
1829 -- The generated body does not freeze. It is analyzed when the
1830 -- generated operation is frozen.
1832 Append_Freeze_Action (Defining_Entity (New_Decl), New_Body);
1834 Result := Defining_Entity (New_Decl);
1837 -- Return the class-wide operation if one was created.
1840 end Check_Class_Wide_Actual;
1842 --------------------------
1843 -- Check_Null_Exclusion --
1844 --------------------------
1846 procedure Check_Null_Exclusion
1850 Ren_Formal : Entity_Id;
1851 Sub_Formal : Entity_Id;
1856 Ren_Formal := First_Formal (Ren);
1857 Sub_Formal := First_Formal (Sub);
1858 while Present (Ren_Formal)
1859 and then Present (Sub_Formal)
1861 if Has_Null_Exclusion (Parent (Ren_Formal))
1863 not (Has_Null_Exclusion (Parent (Sub_Formal))
1864 or else Can_Never_Be_Null (Etype (Sub_Formal)))
1867 ("`NOT NULL` required for parameter &",
1868 Parent (Sub_Formal), Sub_Formal);
1871 Next_Formal (Ren_Formal);
1872 Next_Formal (Sub_Formal);
1875 -- Return profile check
1877 if Nkind (Parent (Ren)) = N_Function_Specification
1878 and then Nkind (Parent (Sub)) = N_Function_Specification
1879 and then Has_Null_Exclusion (Parent (Ren))
1881 not (Has_Null_Exclusion (Parent (Sub))
1882 or else Can_Never_Be_Null (Etype (Sub)))
1885 ("return must specify `NOT NULL`",
1886 Result_Definition (Parent (Sub)));
1888 end Check_Null_Exclusion;
1890 -------------------------
1891 -- Original_Subprogram --
1892 -------------------------
1894 function Original_Subprogram (Subp : Entity_Id) return Entity_Id is
1895 Orig_Decl : Node_Id;
1896 Orig_Subp : Entity_Id;
1899 -- First case: renamed entity is itself a renaming
1901 if Present (Alias (Subp)) then
1902 return Alias (Subp);
1905 Nkind (Unit_Declaration_Node (Subp)) = N_Subprogram_Declaration
1907 (Corresponding_Body (Unit_Declaration_Node (Subp)))
1909 -- Check if renamed entity is a renaming_as_body
1912 Unit_Declaration_Node
1913 (Corresponding_Body (Unit_Declaration_Node (Subp)));
1915 if Nkind (Orig_Decl) = N_Subprogram_Renaming_Declaration then
1916 Orig_Subp := Entity (Name (Orig_Decl));
1918 if Orig_Subp = Rename_Spec then
1920 -- Circularity detected
1925 return (Original_Subprogram (Orig_Subp));
1933 end Original_Subprogram;
1935 -- Start of processing for Analyze_Subprogram_Renaming
1938 -- We must test for the attribute renaming case before the Analyze
1939 -- call because otherwise Sem_Attr will complain that the attribute
1940 -- is missing an argument when it is analyzed.
1942 if Nkind (Nam) = N_Attribute_Reference then
1944 -- In the case of an abstract formal subprogram association, rewrite
1945 -- an actual given by a stream attribute as the name of the
1946 -- corresponding stream primitive of the type.
1948 -- In a generic context the stream operations are not generated, and
1949 -- this must be treated as a normal attribute reference, to be
1950 -- expanded in subsequent instantiations.
1952 if Is_Actual and then Is_Abstract_Subprogram (Formal_Spec)
1953 and then Expander_Active
1956 Stream_Prim : Entity_Id;
1957 Prefix_Type : constant Entity_Id := Entity (Prefix (Nam));
1960 -- The class-wide forms of the stream attributes are not
1961 -- primitive dispatching operations (even though they
1962 -- internally dispatch to a stream attribute).
1964 if Is_Class_Wide_Type (Prefix_Type) then
1966 ("attribute must be a primitive dispatching operation",
1971 -- Retrieve the primitive subprogram associated with the
1972 -- attribute. This can only be a stream attribute, since those
1973 -- are the only ones that are dispatching (and the actual for
1974 -- an abstract formal subprogram must be dispatching
1978 case Attribute_Name (Nam) is
1981 Find_Prim_Op (Prefix_Type, TSS_Stream_Input);
1984 Find_Prim_Op (Prefix_Type, TSS_Stream_Output);
1987 Find_Prim_Op (Prefix_Type, TSS_Stream_Read);
1990 Find_Prim_Op (Prefix_Type, TSS_Stream_Write);
1993 ("attribute must be a primitive"
1994 & " dispatching operation", Nam);
2000 -- If no operation was found, and the type is limited,
2001 -- the user should have defined one.
2003 when Program_Error =>
2004 if Is_Limited_Type (Prefix_Type) then
2006 ("stream operation not defined for type&",
2010 -- Otherwise, compiler should have generated default
2017 -- Rewrite the attribute into the name of its corresponding
2018 -- primitive dispatching subprogram. We can then proceed with
2019 -- the usual processing for subprogram renamings.
2022 Prim_Name : constant Node_Id :=
2023 Make_Identifier (Sloc (Nam),
2024 Chars => Chars (Stream_Prim));
2026 Set_Entity (Prim_Name, Stream_Prim);
2027 Rewrite (Nam, Prim_Name);
2032 -- Normal processing for a renaming of an attribute
2035 Attribute_Renaming (N);
2040 -- Check whether this declaration corresponds to the instantiation
2041 -- of a formal subprogram.
2043 -- If this is an instantiation, the corresponding actual is frozen and
2044 -- error messages can be made more precise. If this is a default
2045 -- subprogram, the entity is already established in the generic, and is
2046 -- not retrieved by visibility. If it is a default with a box, the
2047 -- candidate interpretations, if any, have been collected when building
2048 -- the renaming declaration. If overloaded, the proper interpretation is
2049 -- determined in Find_Renamed_Entity. If the entity is an operator,
2050 -- Find_Renamed_Entity applies additional visibility checks.
2053 Inst_Node := Unit_Declaration_Node (Formal_Spec);
2055 if Is_Entity_Name (Nam)
2056 and then Present (Entity (Nam))
2057 and then not Comes_From_Source (Nam)
2058 and then not Is_Overloaded (Nam)
2060 Old_S := Entity (Nam);
2061 New_S := Analyze_Subprogram_Specification (Spec);
2065 if Ekind (Entity (Nam)) = E_Operator then
2069 if Box_Present (Inst_Node) then
2070 Old_S := Find_Renamed_Entity (N, Name (N), New_S, Is_Actual);
2072 -- If there is an immediately visible homonym of the operator
2073 -- and the declaration has a default, this is worth a warning
2074 -- because the user probably did not intend to get the pre-
2075 -- defined operator, visible in the generic declaration. To
2076 -- find if there is an intended candidate, analyze the renaming
2077 -- again in the current context.
2079 elsif Scope (Old_S) = Standard_Standard
2080 and then Present (Default_Name (Inst_Node))
2083 Decl : constant Node_Id := New_Copy_Tree (N);
2087 Set_Entity (Name (Decl), Empty);
2088 Analyze (Name (Decl));
2090 Find_Renamed_Entity (Decl, Name (Decl), New_S, True);
2093 and then In_Open_Scopes (Scope (Hidden))
2094 and then Is_Immediately_Visible (Hidden)
2095 and then Comes_From_Source (Hidden)
2096 and then Hidden /= Old_S
2098 Error_Msg_Sloc := Sloc (Hidden);
2099 Error_Msg_N ("?default subprogram is resolved " &
2100 "in the generic declaration " &
2101 "(RM 12.6(17))", N);
2102 Error_Msg_NE ("\?and will not use & #", N, Hidden);
2110 New_S := Analyze_Subprogram_Specification (Spec);
2114 -- Renamed entity must be analyzed first, to avoid being hidden by
2115 -- new name (which might be the same in a generic instance).
2119 -- The renaming defines a new overloaded entity, which is analyzed
2120 -- like a subprogram declaration.
2122 New_S := Analyze_Subprogram_Specification (Spec);
2125 if Current_Scope /= Standard_Standard then
2126 Set_Is_Pure (New_S, Is_Pure (Current_Scope));
2129 Rename_Spec := Find_Corresponding_Spec (N);
2131 -- Case of Renaming_As_Body
2133 if Present (Rename_Spec) then
2135 -- Renaming declaration is the completion of the declaration of
2136 -- Rename_Spec. We build an actual body for it at the freezing point.
2138 Set_Corresponding_Spec (N, Rename_Spec);
2140 -- Deal with special case of stream functions of abstract types
2143 if Nkind (Unit_Declaration_Node (Rename_Spec)) =
2144 N_Abstract_Subprogram_Declaration
2146 -- Input stream functions are abstract if the object type is
2147 -- abstract. Similarly, all default stream functions for an
2148 -- interface type are abstract. However, these subprograms may
2149 -- receive explicit declarations in representation clauses, making
2150 -- the attribute subprograms usable as defaults in subsequent
2152 -- In this case we rewrite the declaration to make the subprogram
2153 -- non-abstract. We remove the previous declaration, and insert
2154 -- the new one at the point of the renaming, to prevent premature
2155 -- access to unfrozen types. The new declaration reuses the
2156 -- specification of the previous one, and must not be analyzed.
2159 (Is_Primitive (Entity (Nam))
2161 Is_Abstract_Type (Find_Dispatching_Type (Entity (Nam))));
2163 Old_Decl : constant Node_Id :=
2164 Unit_Declaration_Node (Rename_Spec);
2165 New_Decl : constant Node_Id :=
2166 Make_Subprogram_Declaration (Sloc (N),
2168 Relocate_Node (Specification (Old_Decl)));
2171 Insert_After (N, New_Decl);
2172 Set_Is_Abstract_Subprogram (Rename_Spec, False);
2173 Set_Analyzed (New_Decl);
2177 Set_Corresponding_Body (Unit_Declaration_Node (Rename_Spec), New_S);
2179 if Ada_Version = Ada_83 and then Comes_From_Source (N) then
2180 Error_Msg_N ("(Ada 83) renaming cannot serve as a body", N);
2183 Set_Convention (New_S, Convention (Rename_Spec));
2184 Check_Fully_Conformant (New_S, Rename_Spec);
2185 Set_Public_Status (New_S);
2187 -- The specification does not introduce new formals, but only
2188 -- repeats the formals of the original subprogram declaration.
2189 -- For cross-reference purposes, and for refactoring tools, we
2190 -- treat the formals of the renaming declaration as body formals.
2192 Reference_Body_Formals (Rename_Spec, New_S);
2194 -- Indicate that the entity in the declaration functions like the
2195 -- corresponding body, and is not a new entity. The body will be
2196 -- constructed later at the freeze point, so indicate that the
2197 -- completion has not been seen yet.
2199 Set_Ekind (New_S, E_Subprogram_Body);
2200 New_S := Rename_Spec;
2201 Set_Has_Completion (Rename_Spec, False);
2203 -- Ada 2005: check overriding indicator
2205 if Present (Overridden_Operation (Rename_Spec)) then
2206 if Must_Not_Override (Specification (N)) then
2208 ("subprogram& overrides inherited operation",
2211 Style_Check and then not Must_Override (Specification (N))
2213 Style.Missing_Overriding (N, Rename_Spec);
2216 elsif Must_Override (Specification (N)) then
2217 Error_Msg_NE ("subprogram& is not overriding", N, Rename_Spec);
2220 -- Normal subprogram renaming (not renaming as body)
2223 Generate_Definition (New_S);
2224 New_Overloaded_Entity (New_S);
2226 if Is_Entity_Name (Nam)
2227 and then Is_Intrinsic_Subprogram (Entity (Nam))
2231 Check_Delayed_Subprogram (New_S);
2235 -- There is no need for elaboration checks on the new entity, which may
2236 -- be called before the next freezing point where the body will appear.
2237 -- Elaboration checks refer to the real entity, not the one created by
2238 -- the renaming declaration.
2240 Set_Kill_Elaboration_Checks (New_S, True);
2242 if Etype (Nam) = Any_Type then
2243 Set_Has_Completion (New_S);
2246 elsif Nkind (Nam) = N_Selected_Component then
2248 -- A prefix of the form A.B can designate an entry of task A, a
2249 -- protected operation of protected object A, or finally a primitive
2250 -- operation of object A. In the later case, A is an object of some
2251 -- tagged type, or an access type that denotes one such. To further
2252 -- distinguish these cases, note that the scope of a task entry or
2253 -- protected operation is type of the prefix.
2255 -- The prefix could be an overloaded function call that returns both
2256 -- kinds of operations. This overloading pathology is left to the
2257 -- dedicated reader ???
2260 T : constant Entity_Id := Etype (Prefix (Nam));
2269 Is_Tagged_Type (Designated_Type (T))))
2270 and then Scope (Entity (Selector_Name (Nam))) /= T
2272 Analyze_Renamed_Primitive_Operation
2273 (N, New_S, Present (Rename_Spec));
2277 -- Renamed entity is an entry or protected operation. For those
2278 -- cases an explicit body is built (at the point of freezing of
2279 -- this entity) that contains a call to the renamed entity.
2281 -- This is not allowed for renaming as body if the renamed
2282 -- spec is already frozen (see RM 8.5.4(5) for details).
2284 if Present (Rename_Spec)
2285 and then Is_Frozen (Rename_Spec)
2288 ("renaming-as-body cannot rename entry as subprogram", N);
2290 ("\since & is already frozen (RM 8.5.4(5))",
2293 Analyze_Renamed_Entry (N, New_S, Present (Rename_Spec));
2300 elsif Nkind (Nam) = N_Explicit_Dereference then
2302 -- Renamed entity is designated by access_to_subprogram expression.
2303 -- Must build body to encapsulate call, as in the entry case.
2305 Analyze_Renamed_Dereference (N, New_S, Present (Rename_Spec));
2308 elsif Nkind (Nam) = N_Indexed_Component then
2309 Analyze_Renamed_Family_Member (N, New_S, Present (Rename_Spec));
2312 elsif Nkind (Nam) = N_Character_Literal then
2313 Analyze_Renamed_Character (N, New_S, Present (Rename_Spec));
2316 elsif not Is_Entity_Name (Nam)
2317 or else not Is_Overloadable (Entity (Nam))
2319 Error_Msg_N ("expect valid subprogram name in renaming", N);
2323 -- Find the renamed entity that matches the given specification. Disable
2324 -- Ada_83 because there is no requirement of full conformance between
2325 -- renamed entity and new entity, even though the same circuit is used.
2327 -- This is a bit of a kludge, which introduces a really irregular use of
2328 -- Ada_Version[_Explicit]. Would be nice to find cleaner way to do this
2331 Ada_Version := Ada_Version_Type'Max (Ada_Version, Ada_95);
2332 Ada_Version_Explicit := Ada_Version;
2335 Old_S := Find_Renamed_Entity (N, Name (N), New_S, Is_Actual);
2337 -- The visible operation may be an inherited abstract operation that
2338 -- was overridden in the private part, in which case a call will
2339 -- dispatch to the overriding operation. Use the overriding one in
2340 -- the renaming declaration, to prevent spurious errors below.
2342 if Is_Overloadable (Old_S)
2343 and then Is_Abstract_Subprogram (Old_S)
2344 and then No (DTC_Entity (Old_S))
2345 and then Present (Alias (Old_S))
2346 and then not Is_Abstract_Subprogram (Alias (Old_S))
2347 and then Present (Overridden_Operation (Alias (Old_S)))
2349 Old_S := Alias (Old_S);
2352 -- When the renamed subprogram is overloaded and used as an actual
2353 -- of a generic, its entity is set to the first available homonym.
2354 -- We must first disambiguate the name, then set the proper entity.
2356 if Is_Actual and then Is_Overloaded (Nam) then
2357 Set_Entity (Nam, Old_S);
2361 -- Most common case: subprogram renames subprogram. No body is generated
2362 -- in this case, so we must indicate the declaration is complete as is.
2363 -- and inherit various attributes of the renamed subprogram.
2365 if No (Rename_Spec) then
2366 Set_Has_Completion (New_S);
2367 Set_Is_Imported (New_S, Is_Imported (Entity (Nam)));
2368 Set_Is_Pure (New_S, Is_Pure (Entity (Nam)));
2369 Set_Is_Preelaborated (New_S, Is_Preelaborated (Entity (Nam)));
2371 -- Ada 2005 (AI-423): Check the consistency of null exclusions
2372 -- between a subprogram and its correct renaming.
2374 -- Note: the Any_Id check is a guard that prevents compiler crashes
2375 -- when performing a null exclusion check between a renaming and a
2376 -- renamed subprogram that has been found to be illegal.
2378 if Ada_Version >= Ada_2005
2379 and then Entity (Nam) /= Any_Id
2381 Check_Null_Exclusion
2383 Sub => Entity (Nam));
2386 -- Enforce the Ada 2005 rule that the renamed entity cannot require
2387 -- overriding. The flag Requires_Overriding is set very selectively
2388 -- and misses some other illegal cases. The additional conditions
2389 -- checked below are sufficient but not necessary ???
2391 -- The rule does not apply to the renaming generated for an actual
2392 -- subprogram in an instance.
2397 -- Guard against previous errors, and omit renamings of predefined
2400 elsif not Ekind_In (Old_S, E_Function, E_Procedure) then
2403 elsif Requires_Overriding (Old_S)
2405 (Is_Abstract_Subprogram (Old_S)
2406 and then Present (Find_Dispatching_Type (Old_S))
2408 not Is_Abstract_Type (Find_Dispatching_Type (Old_S)))
2411 ("renamed entity cannot be "
2412 & "subprogram that requires overriding (RM 8.5.4 (5.1))", N);
2416 -- If no renamed entity was found, check whether the renaming is for
2417 -- a defaulted actual subprogram with a class-wide actual.
2421 and then From_Default (N)
2423 Old_S := Check_Class_Wide_Actual;
2426 if Old_S /= Any_Id then
2427 if Is_Actual and then From_Default (N) then
2428 -- This is an implicit reference to the default actual
2430 Generate_Reference (Old_S, Nam, Typ => 'i', Force => True);
2432 Generate_Reference (Old_S, Nam);
2435 -- For a renaming-as-body, require subtype conformance, but if the
2436 -- declaration being completed has not been frozen, then inherit the
2437 -- convention of the renamed subprogram prior to checking conformance
2438 -- (unless the renaming has an explicit convention established; the
2439 -- rule stated in the RM doesn't seem to address this ???).
2441 if Present (Rename_Spec) then
2442 Generate_Reference (Rename_Spec, Defining_Entity (Spec), 'b');
2443 Style.Check_Identifier (Defining_Entity (Spec), Rename_Spec);
2445 if not Is_Frozen (Rename_Spec) then
2446 if not Has_Convention_Pragma (Rename_Spec) then
2447 Set_Convention (New_S, Convention (Old_S));
2450 if Ekind (Old_S) /= E_Operator then
2451 Check_Mode_Conformant (New_S, Old_S, Spec);
2454 if Original_Subprogram (Old_S) = Rename_Spec then
2455 Error_Msg_N ("unfrozen subprogram cannot rename itself ", N);
2458 Check_Subtype_Conformant (New_S, Old_S, Spec);
2461 Check_Frozen_Renaming (N, Rename_Spec);
2463 -- Check explicitly that renamed entity is not intrinsic, because
2464 -- in a generic the renamed body is not built. In this case,
2465 -- the renaming_as_body is a completion.
2467 if Inside_A_Generic then
2468 if Is_Frozen (Rename_Spec)
2469 and then Is_Intrinsic_Subprogram (Old_S)
2472 ("subprogram in renaming_as_body cannot be intrinsic",
2476 Set_Has_Completion (Rename_Spec);
2479 elsif Ekind (Old_S) /= E_Operator then
2481 -- If this a defaulted subprogram for a class-wide actual there is
2482 -- no check for mode conformance, given that the signatures don't
2483 -- match (the source mentions T but the actual mentions T'class).
2488 Check_Mode_Conformant (New_S, Old_S);
2492 and then Error_Posted (New_S)
2494 Error_Msg_NE ("invalid actual subprogram: & #!", N, Old_S);
2498 if No (Rename_Spec) then
2500 -- The parameter profile of the new entity is that of the renamed
2501 -- entity: the subtypes given in the specification are irrelevant.
2503 Inherit_Renamed_Profile (New_S, Old_S);
2505 -- A call to the subprogram is transformed into a call to the
2506 -- renamed entity. This is transitive if the renamed entity is
2507 -- itself a renaming.
2509 if Present (Alias (Old_S)) then
2510 Set_Alias (New_S, Alias (Old_S));
2512 Set_Alias (New_S, Old_S);
2515 -- Note that we do not set Is_Intrinsic_Subprogram if we have a
2516 -- renaming as body, since the entity in this case is not an
2517 -- intrinsic (it calls an intrinsic, but we have a real body for
2518 -- this call, and it is in this body that the required intrinsic
2519 -- processing will take place).
2521 -- Also, if this is a renaming of inequality, the renamed operator
2522 -- is intrinsic, but what matters is the corresponding equality
2523 -- operator, which may be user-defined.
2525 Set_Is_Intrinsic_Subprogram
2527 Is_Intrinsic_Subprogram (Old_S)
2529 (Chars (Old_S) /= Name_Op_Ne
2530 or else Ekind (Old_S) = E_Operator
2532 Is_Intrinsic_Subprogram
2533 (Corresponding_Equality (Old_S))));
2535 if Ekind (Alias (New_S)) = E_Operator then
2536 Set_Has_Delayed_Freeze (New_S, False);
2539 -- If the renaming corresponds to an association for an abstract
2540 -- formal subprogram, then various attributes must be set to
2541 -- indicate that the renaming is an abstract dispatching operation
2542 -- with a controlling type.
2544 if Is_Actual and then Is_Abstract_Subprogram (Formal_Spec) then
2546 -- Mark the renaming as abstract here, so Find_Dispatching_Type
2547 -- see it as corresponding to a generic association for a
2548 -- formal abstract subprogram
2550 Set_Is_Abstract_Subprogram (New_S);
2553 New_S_Ctrl_Type : constant Entity_Id :=
2554 Find_Dispatching_Type (New_S);
2555 Old_S_Ctrl_Type : constant Entity_Id :=
2556 Find_Dispatching_Type (Old_S);
2559 if Old_S_Ctrl_Type /= New_S_Ctrl_Type then
2561 ("actual must be dispatching subprogram for type&",
2562 Nam, New_S_Ctrl_Type);
2565 Set_Is_Dispatching_Operation (New_S);
2566 Check_Controlling_Formals (New_S_Ctrl_Type, New_S);
2568 -- If the actual in the formal subprogram is itself a
2569 -- formal abstract subprogram association, there's no
2570 -- dispatch table component or position to inherit.
2572 if Present (DTC_Entity (Old_S)) then
2573 Set_DTC_Entity (New_S, DTC_Entity (Old_S));
2574 Set_DT_Position (New_S, DT_Position (Old_S));
2582 and then (Old_S = New_S
2583 or else (Nkind (Nam) /= N_Expanded_Name
2584 and then Chars (Old_S) = Chars (New_S)))
2586 Error_Msg_N ("subprogram cannot rename itself", N);
2589 Set_Convention (New_S, Convention (Old_S));
2591 if Is_Abstract_Subprogram (Old_S) then
2592 if Present (Rename_Spec) then
2594 ("a renaming-as-body cannot rename an abstract subprogram",
2596 Set_Has_Completion (Rename_Spec);
2598 Set_Is_Abstract_Subprogram (New_S);
2602 Check_Library_Unit_Renaming (N, Old_S);
2604 -- Pathological case: procedure renames entry in the scope of its
2605 -- task. Entry is given by simple name, but body must be built for
2606 -- procedure. Of course if called it will deadlock.
2608 if Ekind (Old_S) = E_Entry then
2609 Set_Has_Completion (New_S, False);
2610 Set_Alias (New_S, Empty);
2614 Freeze_Before (N, Old_S);
2615 Set_Has_Delayed_Freeze (New_S, False);
2616 Freeze_Before (N, New_S);
2618 -- An abstract subprogram is only allowed as an actual in the case
2619 -- where the formal subprogram is also abstract.
2621 if (Ekind (Old_S) = E_Procedure or else Ekind (Old_S) = E_Function)
2622 and then Is_Abstract_Subprogram (Old_S)
2623 and then not Is_Abstract_Subprogram (Formal_Spec)
2626 ("abstract subprogram not allowed as generic actual", Nam);
2631 -- A common error is to assume that implicit operators for types are
2632 -- defined in Standard, or in the scope of a subtype. In those cases
2633 -- where the renamed entity is given with an expanded name, it is
2634 -- worth mentioning that operators for the type are not declared in
2635 -- the scope given by the prefix.
2637 if Nkind (Nam) = N_Expanded_Name
2638 and then Nkind (Selector_Name (Nam)) = N_Operator_Symbol
2639 and then Scope (Entity (Nam)) = Standard_Standard
2642 T : constant Entity_Id :=
2643 Base_Type (Etype (First_Formal (New_S)));
2645 Error_Msg_Node_2 := Prefix (Nam);
2647 ("operator for type& is not declared in&", Prefix (Nam), T);
2652 ("no visible subprogram matches the specification for&",
2656 if Present (Candidate_Renaming) then
2663 F1 := First_Formal (Candidate_Renaming);
2664 F2 := First_Formal (New_S);
2665 T1 := First_Subtype (Etype (F1));
2667 while Present (F1) and then Present (F2) loop
2672 if Present (F1) and then Present (Default_Value (F1)) then
2673 if Present (Next_Formal (F1)) then
2675 ("\missing specification for &" &
2676 " and other formals with defaults", Spec, F1);
2679 ("\missing specification for &", Spec, F1);
2683 if Nkind (Nam) = N_Operator_Symbol
2684 and then From_Default (N)
2686 Error_Msg_Node_2 := T1;
2688 ("default & on & is not directly visible",
2695 -- Ada 2005 AI 404: if the new subprogram is dispatching, verify that
2696 -- controlling access parameters are known non-null for the renamed
2697 -- subprogram. Test also applies to a subprogram instantiation that
2698 -- is dispatching. Test is skipped if some previous error was detected
2699 -- that set Old_S to Any_Id.
2701 if Ada_Version >= Ada_2005
2702 and then Old_S /= Any_Id
2703 and then not Is_Dispatching_Operation (Old_S)
2704 and then Is_Dispatching_Operation (New_S)
2711 Old_F := First_Formal (Old_S);
2712 New_F := First_Formal (New_S);
2713 while Present (Old_F) loop
2714 if Ekind (Etype (Old_F)) = E_Anonymous_Access_Type
2715 and then Is_Controlling_Formal (New_F)
2716 and then not Can_Never_Be_Null (Old_F)
2718 Error_Msg_N ("access parameter is controlling,", New_F);
2720 ("\corresponding parameter of& "
2721 & "must be explicitly null excluding", New_F, Old_S);
2724 Next_Formal (Old_F);
2725 Next_Formal (New_F);
2730 -- A useful warning, suggested by Ada Bug Finder (Ada-Europe 2005)
2731 -- is to warn if an operator is being renamed as a different operator.
2732 -- If the operator is predefined, examine the kind of the entity, not
2733 -- the abbreviated declaration in Standard.
2735 if Comes_From_Source (N)
2736 and then Present (Old_S)
2738 (Nkind (Old_S) = N_Defining_Operator_Symbol
2739 or else Ekind (Old_S) = E_Operator)
2740 and then Nkind (New_S) = N_Defining_Operator_Symbol
2741 and then Chars (Old_S) /= Chars (New_S)
2744 ("?& is being renamed as a different operator", N, Old_S);
2747 -- Check for renaming of obsolescent subprogram
2749 Check_Obsolescent_2005_Entity (Entity (Nam), Nam);
2751 -- Another warning or some utility: if the new subprogram as the same
2752 -- name as the old one, the old one is not hidden by an outer homograph,
2753 -- the new one is not a public symbol, and the old one is otherwise
2754 -- directly visible, the renaming is superfluous.
2756 if Chars (Old_S) = Chars (New_S)
2757 and then Comes_From_Source (N)
2758 and then Scope (Old_S) /= Standard_Standard
2759 and then Warn_On_Redundant_Constructs
2761 (Is_Immediately_Visible (Old_S)
2762 or else Is_Potentially_Use_Visible (Old_S))
2763 and then Is_Overloadable (Current_Scope)
2764 and then Chars (Current_Scope) /= Chars (Old_S)
2767 ("?redundant renaming, entity is directly visible", Name (N));
2770 Ada_Version := Save_AV;
2771 Ada_Version_Explicit := Save_AV_Exp;
2772 end Analyze_Subprogram_Renaming;
2774 -------------------------
2775 -- Analyze_Use_Package --
2776 -------------------------
2778 -- Resolve the package names in the use clause, and make all the visible
2779 -- entities defined in the package potentially use-visible. If the package
2780 -- is already in use from a previous use clause, its visible entities are
2781 -- already use-visible. In that case, mark the occurrence as a redundant
2782 -- use. If the package is an open scope, i.e. if the use clause occurs
2783 -- within the package itself, ignore it.
2785 procedure Analyze_Use_Package (N : Node_Id) is
2786 Pack_Name : Node_Id;
2789 -- Start of processing for Analyze_Use_Package
2792 Check_SPARK_Restriction ("use clause is not allowed", N);
2794 Set_Hidden_By_Use_Clause (N, No_Elist);
2796 -- Use clause not allowed in a spec of a predefined package declaration
2797 -- except that packages whose file name starts a-n are OK (these are
2798 -- children of Ada.Numerics, which are never loaded by Rtsfind).
2800 if Is_Predefined_File_Name (Unit_File_Name (Current_Sem_Unit))
2801 and then Name_Buffer (1 .. 3) /= "a-n"
2803 Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Declaration
2805 Error_Msg_N ("use clause not allowed in predefined spec", N);
2808 -- Chain clause to list of use clauses in current scope
2810 if Nkind (Parent (N)) /= N_Compilation_Unit then
2811 Chain_Use_Clause (N);
2814 -- Loop through package names to identify referenced packages
2816 Pack_Name := First (Names (N));
2817 while Present (Pack_Name) loop
2818 Analyze (Pack_Name);
2820 if Nkind (Parent (N)) = N_Compilation_Unit
2821 and then Nkind (Pack_Name) = N_Expanded_Name
2827 Pref := Prefix (Pack_Name);
2828 while Nkind (Pref) = N_Expanded_Name loop
2829 Pref := Prefix (Pref);
2832 if Entity (Pref) = Standard_Standard then
2834 ("predefined package Standard cannot appear"
2835 & " in a context clause", Pref);
2843 -- Loop through package names to mark all entities as potentially
2846 Pack_Name := First (Names (N));
2847 while Present (Pack_Name) loop
2848 if Is_Entity_Name (Pack_Name) then
2849 Pack := Entity (Pack_Name);
2851 if Ekind (Pack) /= E_Package
2852 and then Etype (Pack) /= Any_Type
2854 if Ekind (Pack) = E_Generic_Package then
2855 Error_Msg_N -- CODEFIX
2856 ("a generic package is not allowed in a use clause",
2859 Error_Msg_N ("& is not a usable package", Pack_Name);
2863 if Nkind (Parent (N)) = N_Compilation_Unit then
2864 Check_In_Previous_With_Clause (N, Pack_Name);
2867 if Applicable_Use (Pack_Name) then
2868 Use_One_Package (Pack, N);
2872 -- Report error because name denotes something other than a package
2875 Error_Msg_N ("& is not a package", Pack_Name);
2880 end Analyze_Use_Package;
2882 ----------------------
2883 -- Analyze_Use_Type --
2884 ----------------------
2886 procedure Analyze_Use_Type (N : Node_Id) is
2891 Set_Hidden_By_Use_Clause (N, No_Elist);
2893 -- Chain clause to list of use clauses in current scope
2895 if Nkind (Parent (N)) /= N_Compilation_Unit then
2896 Chain_Use_Clause (N);
2899 -- If the Used_Operations list is already initialized, the clause has
2900 -- been analyzed previously, and it is begin reinstalled, for example
2901 -- when the clause appears in a package spec and we are compiling the
2902 -- corresponding package body. In that case, make the entities on the
2903 -- existing list use_visible, and mark the corresponding types In_Use.
2905 if Present (Used_Operations (N)) then
2911 Mark := First (Subtype_Marks (N));
2912 while Present (Mark) loop
2913 Use_One_Type (Mark, Installed => True);
2917 Elmt := First_Elmt (Used_Operations (N));
2918 while Present (Elmt) loop
2919 Set_Is_Potentially_Use_Visible (Node (Elmt));
2927 -- Otherwise, create new list and attach to it the operations that
2928 -- are made use-visible by the clause.
2930 Set_Used_Operations (N, New_Elmt_List);
2931 Id := First (Subtype_Marks (N));
2932 while Present (Id) loop
2936 if E /= Any_Type then
2939 if Nkind (Parent (N)) = N_Compilation_Unit then
2940 if Nkind (Id) = N_Identifier then
2941 Error_Msg_N ("type is not directly visible", Id);
2943 elsif Is_Child_Unit (Scope (E))
2944 and then Scope (E) /= System_Aux_Id
2946 Check_In_Previous_With_Clause (N, Prefix (Id));
2951 -- If the use_type_clause appears in a compilation unit context,
2952 -- check whether it comes from a unit that may appear in a
2953 -- limited_with_clause, for a better error message.
2955 if Nkind (Parent (N)) = N_Compilation_Unit
2956 and then Nkind (Id) /= N_Identifier
2962 function Mentioned (Nam : Node_Id) return Boolean;
2963 -- Check whether the prefix of expanded name for the type
2964 -- appears in the prefix of some limited_with_clause.
2970 function Mentioned (Nam : Node_Id) return Boolean is
2972 return Nkind (Name (Item)) = N_Selected_Component
2974 Chars (Prefix (Name (Item))) = Chars (Nam);
2978 Pref := Prefix (Id);
2979 Item := First (Context_Items (Parent (N)));
2981 while Present (Item) and then Item /= N loop
2982 if Nkind (Item) = N_With_Clause
2983 and then Limited_Present (Item)
2984 and then Mentioned (Pref)
2987 (Get_Msg_Id, "premature usage of incomplete type");
2998 end Analyze_Use_Type;
3000 --------------------
3001 -- Applicable_Use --
3002 --------------------
3004 function Applicable_Use (Pack_Name : Node_Id) return Boolean is
3005 Pack : constant Entity_Id := Entity (Pack_Name);
3008 if In_Open_Scopes (Pack) then
3009 if Warn_On_Redundant_Constructs
3010 and then Pack = Current_Scope
3012 Error_Msg_NE -- CODEFIX
3013 ("& is already use-visible within itself?", Pack_Name, Pack);
3018 elsif In_Use (Pack) then
3019 Note_Redundant_Use (Pack_Name);
3022 elsif Present (Renamed_Object (Pack))
3023 and then In_Use (Renamed_Object (Pack))
3025 Note_Redundant_Use (Pack_Name);
3033 ------------------------
3034 -- Attribute_Renaming --
3035 ------------------------
3037 procedure Attribute_Renaming (N : Node_Id) is
3038 Loc : constant Source_Ptr := Sloc (N);
3039 Nam : constant Node_Id := Name (N);
3040 Spec : constant Node_Id := Specification (N);
3041 New_S : constant Entity_Id := Defining_Unit_Name (Spec);
3042 Aname : constant Name_Id := Attribute_Name (Nam);
3044 Form_Num : Nat := 0;
3045 Expr_List : List_Id := No_List;
3047 Attr_Node : Node_Id;
3048 Body_Node : Node_Id;
3049 Param_Spec : Node_Id;
3052 Generate_Definition (New_S);
3054 -- This procedure is called in the context of subprogram renaming, and
3055 -- thus the attribute must be one that is a subprogram. All of those
3056 -- have at least one formal parameter, with the singular exception of
3057 -- AST_Entry (which is a real oddity, it is odd that this can be renamed
3060 if not Is_Non_Empty_List (Parameter_Specifications (Spec)) then
3061 if Aname /= Name_AST_Entry then
3063 ("subprogram renaming an attribute must have formals", N);
3068 Param_Spec := First (Parameter_Specifications (Spec));
3069 while Present (Param_Spec) loop
3070 Form_Num := Form_Num + 1;
3072 if Nkind (Parameter_Type (Param_Spec)) /= N_Access_Definition then
3073 Find_Type (Parameter_Type (Param_Spec));
3075 -- The profile of the new entity denotes the base type (s) of
3076 -- the types given in the specification. For access parameters
3077 -- there are no subtypes involved.
3079 Rewrite (Parameter_Type (Param_Spec),
3081 (Base_Type (Entity (Parameter_Type (Param_Spec))), Loc));
3084 if No (Expr_List) then
3085 Expr_List := New_List;
3088 Append_To (Expr_List,
3089 Make_Identifier (Loc,
3090 Chars => Chars (Defining_Identifier (Param_Spec))));
3092 -- The expressions in the attribute reference are not freeze
3093 -- points. Neither is the attribute as a whole, see below.
3095 Set_Must_Not_Freeze (Last (Expr_List));
3100 -- Immediate error if too many formals. Other mismatches in number or
3101 -- types of parameters are detected when we analyze the body of the
3102 -- subprogram that we construct.
3104 if Form_Num > 2 then
3105 Error_Msg_N ("too many formals for attribute", N);
3107 -- Error if the attribute reference has expressions that look like
3108 -- formal parameters.
3110 elsif Present (Expressions (Nam)) then
3111 Error_Msg_N ("illegal expressions in attribute reference", Nam);
3114 Aname = Name_Compose or else
3115 Aname = Name_Exponent or else
3116 Aname = Name_Leading_Part or else
3117 Aname = Name_Pos or else
3118 Aname = Name_Round or else
3119 Aname = Name_Scaling or else
3122 if Nkind (N) = N_Subprogram_Renaming_Declaration
3123 and then Present (Corresponding_Formal_Spec (N))
3126 ("generic actual cannot be attribute involving universal type",
3130 ("attribute involving a universal type cannot be renamed",
3135 -- AST_Entry is an odd case. It doesn't really make much sense to allow
3136 -- it to be renamed, but that's the DEC rule, so we have to do it right.
3137 -- The point is that the AST_Entry call should be made now, and what the
3138 -- function will return is the returned value.
3140 -- Note that there is no Expr_List in this case anyway
3142 if Aname = Name_AST_Entry then
3144 Ent : constant Entity_Id := Make_Temporary (Loc, 'R', Nam);
3149 Make_Object_Declaration (Loc,
3150 Defining_Identifier => Ent,
3151 Object_Definition =>
3152 New_Occurrence_Of (RTE (RE_AST_Handler), Loc),
3154 Constant_Present => True);
3156 Set_Assignment_OK (Decl, True);
3157 Insert_Action (N, Decl);
3158 Attr_Node := Make_Identifier (Loc, Chars (Ent));
3161 -- For all other attributes, we rewrite the attribute node to have
3162 -- a list of expressions corresponding to the subprogram formals.
3163 -- A renaming declaration is not a freeze point, and the analysis of
3164 -- the attribute reference should not freeze the type of the prefix.
3168 Make_Attribute_Reference (Loc,
3169 Prefix => Prefix (Nam),
3170 Attribute_Name => Aname,
3171 Expressions => Expr_List);
3173 Set_Must_Not_Freeze (Attr_Node);
3174 Set_Must_Not_Freeze (Prefix (Nam));
3177 -- Case of renaming a function
3179 if Nkind (Spec) = N_Function_Specification then
3180 if Is_Procedure_Attribute_Name (Aname) then
3181 Error_Msg_N ("attribute can only be renamed as procedure", Nam);
3185 Find_Type (Result_Definition (Spec));
3186 Rewrite (Result_Definition (Spec),
3188 Base_Type (Entity (Result_Definition (Spec))), Loc));
3191 Make_Subprogram_Body (Loc,
3192 Specification => Spec,
3193 Declarations => New_List,
3194 Handled_Statement_Sequence =>
3195 Make_Handled_Sequence_Of_Statements (Loc,
3196 Statements => New_List (
3197 Make_Simple_Return_Statement (Loc,
3198 Expression => Attr_Node))));
3200 -- Case of renaming a procedure
3203 if not Is_Procedure_Attribute_Name (Aname) then
3204 Error_Msg_N ("attribute can only be renamed as function", Nam);
3209 Make_Subprogram_Body (Loc,
3210 Specification => Spec,
3211 Declarations => New_List,
3212 Handled_Statement_Sequence =>
3213 Make_Handled_Sequence_Of_Statements (Loc,
3214 Statements => New_List (Attr_Node)));
3217 -- In case of tagged types we add the body of the generated function to
3218 -- the freezing actions of the type (because in the general case such
3219 -- type is still not frozen). We exclude from this processing generic
3220 -- formal subprograms found in instantiations and AST_Entry renamings.
3222 -- We must exclude VM targets because entity AST_Handler is defined in
3223 -- package System.Aux_Dec which is not available in those platforms.
3225 if VM_Target = No_VM
3226 and then not Present (Corresponding_Formal_Spec (N))
3227 and then Etype (Nam) /= RTE (RE_AST_Handler)
3230 P : constant Entity_Id := Prefix (Nam);
3235 if Is_Tagged_Type (Etype (P)) then
3236 Ensure_Freeze_Node (Etype (P));
3237 Append_Freeze_Action (Etype (P), Body_Node);
3239 Rewrite (N, Body_Node);
3241 Set_Etype (New_S, Base_Type (Etype (New_S)));
3245 -- Generic formal subprograms or AST_Handler renaming
3248 Rewrite (N, Body_Node);
3250 Set_Etype (New_S, Base_Type (Etype (New_S)));
3253 if Is_Compilation_Unit (New_S) then
3255 ("a library unit can only rename another library unit", N);
3258 -- We suppress elaboration warnings for the resulting entity, since
3259 -- clearly they are not needed, and more particularly, in the case
3260 -- of a generic formal subprogram, the resulting entity can appear
3261 -- after the instantiation itself, and thus look like a bogus case
3262 -- of access before elaboration.
3264 Set_Suppress_Elaboration_Warnings (New_S);
3266 end Attribute_Renaming;
3268 ----------------------
3269 -- Chain_Use_Clause --
3270 ----------------------
3272 procedure Chain_Use_Clause (N : Node_Id) is
3274 Level : Int := Scope_Stack.Last;
3277 if not Is_Compilation_Unit (Current_Scope)
3278 or else not Is_Child_Unit (Current_Scope)
3280 null; -- Common case
3282 elsif Defining_Entity (Parent (N)) = Current_Scope then
3283 null; -- Common case for compilation unit
3286 -- If declaration appears in some other scope, it must be in some
3287 -- parent unit when compiling a child.
3289 Pack := Defining_Entity (Parent (N));
3290 if not In_Open_Scopes (Pack) then
3291 null; -- default as well
3294 -- Find entry for parent unit in scope stack
3296 while Scope_Stack.Table (Level).Entity /= Pack loop
3302 Set_Next_Use_Clause (N,
3303 Scope_Stack.Table (Level).First_Use_Clause);
3304 Scope_Stack.Table (Level).First_Use_Clause := N;
3305 end Chain_Use_Clause;
3307 ---------------------------
3308 -- Check_Frozen_Renaming --
3309 ---------------------------
3311 procedure Check_Frozen_Renaming (N : Node_Id; Subp : Entity_Id) is
3317 and then not Has_Completion (Subp)
3321 (Parent (Declaration_Node (Subp)), Defining_Entity (N));
3323 if Is_Entity_Name (Name (N)) then
3324 Old_S := Entity (Name (N));
3326 if not Is_Frozen (Old_S)
3327 and then Operating_Mode /= Check_Semantics
3329 Append_Freeze_Action (Old_S, B_Node);
3331 Insert_After (N, B_Node);
3335 if Is_Intrinsic_Subprogram (Old_S)
3336 and then not In_Instance
3339 ("subprogram used in renaming_as_body cannot be intrinsic",
3344 Insert_After (N, B_Node);
3348 end Check_Frozen_Renaming;
3350 -------------------------------
3351 -- Set_Entity_Or_Discriminal --
3352 -------------------------------
3354 procedure Set_Entity_Or_Discriminal (N : Node_Id; E : Entity_Id) is
3358 -- If the entity is not a discriminant, or else expansion is disabled,
3359 -- simply set the entity.
3361 if not In_Spec_Expression
3362 or else Ekind (E) /= E_Discriminant
3363 or else Inside_A_Generic
3365 Set_Entity_With_Style_Check (N, E);
3367 -- The replacement of a discriminant by the corresponding discriminal
3368 -- is not done for a task discriminant that appears in a default
3369 -- expression of an entry parameter. See Exp_Ch2.Expand_Discriminant
3370 -- for details on their handling.
3372 elsif Is_Concurrent_Type (Scope (E)) then
3376 and then not Nkind_In (P, N_Parameter_Specification,
3377 N_Component_Declaration)
3383 and then Nkind (P) = N_Parameter_Specification
3388 Set_Entity (N, Discriminal (E));
3391 -- Otherwise, this is a discriminant in a context in which
3392 -- it is a reference to the corresponding parameter of the
3393 -- init proc for the enclosing type.
3396 Set_Entity (N, Discriminal (E));
3398 end Set_Entity_Or_Discriminal;
3400 -----------------------------------
3401 -- Check_In_Previous_With_Clause --
3402 -----------------------------------
3404 procedure Check_In_Previous_With_Clause
3408 Pack : constant Entity_Id := Entity (Original_Node (Nam));
3413 Item := First (Context_Items (Parent (N)));
3415 while Present (Item)
3418 if Nkind (Item) = N_With_Clause
3420 -- Protect the frontend against previous critical errors
3422 and then Nkind (Name (Item)) /= N_Selected_Component
3423 and then Entity (Name (Item)) = Pack
3427 -- Find root library unit in with_clause
3429 while Nkind (Par) = N_Expanded_Name loop
3430 Par := Prefix (Par);
3433 if Is_Child_Unit (Entity (Original_Node (Par))) then
3434 Error_Msg_NE ("& is not directly visible", Par, Entity (Par));
3443 -- On exit, package is not mentioned in a previous with_clause.
3444 -- Check if its prefix is.
3446 if Nkind (Nam) = N_Expanded_Name then
3447 Check_In_Previous_With_Clause (N, Prefix (Nam));
3449 elsif Pack /= Any_Id then
3450 Error_Msg_NE ("& is not visible", Nam, Pack);
3452 end Check_In_Previous_With_Clause;
3454 ---------------------------------
3455 -- Check_Library_Unit_Renaming --
3456 ---------------------------------
3458 procedure Check_Library_Unit_Renaming (N : Node_Id; Old_E : Entity_Id) is
3462 if Nkind (Parent (N)) /= N_Compilation_Unit then
3465 -- Check for library unit. Note that we used to check for the scope
3466 -- being Standard here, but that was wrong for Standard itself.
3468 elsif not Is_Compilation_Unit (Old_E)
3469 and then not Is_Child_Unit (Old_E)
3471 Error_Msg_N ("renamed unit must be a library unit", Name (N));
3473 -- Entities defined in Standard (operators and boolean literals) cannot
3474 -- be renamed as library units.
3476 elsif Scope (Old_E) = Standard_Standard
3477 and then Sloc (Old_E) = Standard_Location
3479 Error_Msg_N ("renamed unit must be a library unit", Name (N));
3481 elsif Present (Parent_Spec (N))
3482 and then Nkind (Unit (Parent_Spec (N))) = N_Generic_Package_Declaration
3483 and then not Is_Child_Unit (Old_E)
3486 ("renamed unit must be a child unit of generic parent", Name (N));
3488 elsif Nkind (N) in N_Generic_Renaming_Declaration
3489 and then Nkind (Name (N)) = N_Expanded_Name
3490 and then Is_Generic_Instance (Entity (Prefix (Name (N))))
3491 and then Is_Generic_Unit (Old_E)
3494 ("renamed generic unit must be a library unit", Name (N));
3496 elsif Is_Package_Or_Generic_Package (Old_E) then
3498 -- Inherit categorization flags
3500 New_E := Defining_Entity (N);
3501 Set_Is_Pure (New_E, Is_Pure (Old_E));
3502 Set_Is_Preelaborated (New_E, Is_Preelaborated (Old_E));
3503 Set_Is_Remote_Call_Interface (New_E,
3504 Is_Remote_Call_Interface (Old_E));
3505 Set_Is_Remote_Types (New_E, Is_Remote_Types (Old_E));
3506 Set_Is_Shared_Passive (New_E, Is_Shared_Passive (Old_E));
3508 end Check_Library_Unit_Renaming;
3514 procedure End_Scope is
3520 Id := First_Entity (Current_Scope);
3521 while Present (Id) loop
3522 -- An entity in the current scope is not necessarily the first one
3523 -- on its homonym chain. Find its predecessor if any,
3524 -- If it is an internal entity, it will not be in the visibility
3525 -- chain altogether, and there is nothing to unchain.
3527 if Id /= Current_Entity (Id) then
3528 Prev := Current_Entity (Id);
3529 while Present (Prev)
3530 and then Present (Homonym (Prev))
3531 and then Homonym (Prev) /= Id
3533 Prev := Homonym (Prev);
3536 -- Skip to end of loop if Id is not in the visibility chain
3538 if No (Prev) or else Homonym (Prev) /= Id then
3546 Set_Is_Immediately_Visible (Id, False);
3548 Outer := Homonym (Id);
3549 while Present (Outer) and then Scope (Outer) = Current_Scope loop
3550 Outer := Homonym (Outer);
3553 -- Reset homonym link of other entities, but do not modify link
3554 -- between entities in current scope, so that the back-end can have
3555 -- a proper count of local overloadings.
3558 Set_Name_Entity_Id (Chars (Id), Outer);
3560 elsif Scope (Prev) /= Scope (Id) then
3561 Set_Homonym (Prev, Outer);
3568 -- If the scope generated freeze actions, place them before the
3569 -- current declaration and analyze them. Type declarations and
3570 -- the bodies of initialization procedures can generate such nodes.
3571 -- We follow the parent chain until we reach a list node, which is
3572 -- the enclosing list of declarations. If the list appears within
3573 -- a protected definition, move freeze nodes outside the protected
3577 (Scope_Stack.Table (Scope_Stack.Last).Pending_Freeze_Actions)
3581 L : constant List_Id := Scope_Stack.Table
3582 (Scope_Stack.Last).Pending_Freeze_Actions;
3585 if Is_Itype (Current_Scope) then
3586 Decl := Associated_Node_For_Itype (Current_Scope);
3588 Decl := Parent (Current_Scope);
3593 while not (Is_List_Member (Decl))
3594 or else Nkind_In (Parent (Decl), N_Protected_Definition,
3597 Decl := Parent (Decl);
3600 Insert_List_Before_And_Analyze (Decl, L);
3609 ---------------------
3610 -- End_Use_Clauses --
3611 ---------------------
3613 procedure End_Use_Clauses (Clause : Node_Id) is
3617 -- Remove Use_Type clauses first, because they affect the
3618 -- visibility of operators in subsequent used packages.
3621 while Present (U) loop
3622 if Nkind (U) = N_Use_Type_Clause then
3626 Next_Use_Clause (U);
3630 while Present (U) loop
3631 if Nkind (U) = N_Use_Package_Clause then
3632 End_Use_Package (U);
3635 Next_Use_Clause (U);
3637 end End_Use_Clauses;
3639 ---------------------
3640 -- End_Use_Package --
3641 ---------------------
3643 procedure End_Use_Package (N : Node_Id) is
3644 Pack_Name : Node_Id;
3649 function Is_Primitive_Operator_In_Use
3651 F : Entity_Id) return Boolean;
3652 -- Check whether Op is a primitive operator of a use-visible type
3654 ----------------------------------
3655 -- Is_Primitive_Operator_In_Use --
3656 ----------------------------------
3658 function Is_Primitive_Operator_In_Use
3660 F : Entity_Id) return Boolean
3662 T : constant Entity_Id := Base_Type (Etype (F));
3664 return In_Use (T) and then Scope (T) = Scope (Op);
3665 end Is_Primitive_Operator_In_Use;
3667 -- Start of processing for End_Use_Package
3670 Pack_Name := First (Names (N));
3671 while Present (Pack_Name) loop
3673 -- Test that Pack_Name actually denotes a package before processing
3675 if Is_Entity_Name (Pack_Name)
3676 and then Ekind (Entity (Pack_Name)) = E_Package
3678 Pack := Entity (Pack_Name);
3680 if In_Open_Scopes (Pack) then
3683 elsif not Redundant_Use (Pack_Name) then
3684 Set_In_Use (Pack, False);
3685 Set_Current_Use_Clause (Pack, Empty);
3687 Id := First_Entity (Pack);
3688 while Present (Id) loop
3690 -- Preserve use-visibility of operators that are primitive
3691 -- operators of a type that is use-visible through an active
3694 if Nkind (Id) = N_Defining_Operator_Symbol
3696 (Is_Primitive_Operator_In_Use
3697 (Id, First_Formal (Id))
3699 (Present (Next_Formal (First_Formal (Id)))
3701 Is_Primitive_Operator_In_Use
3702 (Id, Next_Formal (First_Formal (Id)))))
3707 Set_Is_Potentially_Use_Visible (Id, False);
3710 if Is_Private_Type (Id)
3711 and then Present (Full_View (Id))
3713 Set_Is_Potentially_Use_Visible (Full_View (Id), False);
3719 if Present (Renamed_Object (Pack)) then
3720 Set_In_Use (Renamed_Object (Pack), False);
3721 Set_Current_Use_Clause (Renamed_Object (Pack), Empty);
3724 if Chars (Pack) = Name_System
3725 and then Scope (Pack) = Standard_Standard
3726 and then Present_System_Aux
3728 Id := First_Entity (System_Aux_Id);
3729 while Present (Id) loop
3730 Set_Is_Potentially_Use_Visible (Id, False);
3732 if Is_Private_Type (Id)
3733 and then Present (Full_View (Id))
3735 Set_Is_Potentially_Use_Visible (Full_View (Id), False);
3741 Set_In_Use (System_Aux_Id, False);
3745 Set_Redundant_Use (Pack_Name, False);
3752 if Present (Hidden_By_Use_Clause (N)) then
3753 Elmt := First_Elmt (Hidden_By_Use_Clause (N));
3754 while Present (Elmt) loop
3756 E : constant Entity_Id := Node (Elmt);
3759 -- Reset either Use_Visibility or Direct_Visibility, depending
3760 -- on how the entity was hidden by the use clause.
3762 if In_Use (Scope (E))
3763 and then Used_As_Generic_Actual (Scope (E))
3765 Set_Is_Potentially_Use_Visible (Node (Elmt));
3767 Set_Is_Immediately_Visible (Node (Elmt));
3774 Set_Hidden_By_Use_Clause (N, No_Elist);
3776 end End_Use_Package;
3782 procedure End_Use_Type (N : Node_Id) is
3787 -- Start of processing for End_Use_Type
3790 Id := First (Subtype_Marks (N));
3791 while Present (Id) loop
3793 -- A call to Rtsfind may occur while analyzing a use_type clause,
3794 -- in which case the type marks are not resolved yet, and there is
3795 -- nothing to remove.
3797 if not Is_Entity_Name (Id) or else No (Entity (Id)) then
3803 if T = Any_Type or else From_With_Type (T) then
3806 -- Note that the use_type clause may mention a subtype of the type
3807 -- whose primitive operations have been made visible. Here as
3808 -- elsewhere, it is the base type that matters for visibility.
3810 elsif In_Open_Scopes (Scope (Base_Type (T))) then
3813 elsif not Redundant_Use (Id) then
3814 Set_In_Use (T, False);
3815 Set_In_Use (Base_Type (T), False);
3816 Set_Current_Use_Clause (T, Empty);
3817 Set_Current_Use_Clause (Base_Type (T), Empty);
3824 if Is_Empty_Elmt_List (Used_Operations (N)) then
3828 Elmt := First_Elmt (Used_Operations (N));
3829 while Present (Elmt) loop
3830 Set_Is_Potentially_Use_Visible (Node (Elmt), False);
3836 ----------------------
3837 -- Find_Direct_Name --
3838 ----------------------
3840 procedure Find_Direct_Name (N : Node_Id) is
3845 Inst : Entity_Id := Empty;
3846 -- Enclosing instance, if any
3848 Homonyms : Entity_Id;
3849 -- Saves start of homonym chain
3851 Nvis_Entity : Boolean;
3852 -- Set True to indicate that there is at least one entity on the homonym
3853 -- chain which, while not visible, is visible enough from the user point
3854 -- of view to warrant an error message of "not visible" rather than
3857 Nvis_Is_Private_Subprg : Boolean := False;
3858 -- Ada 2005 (AI-262): Set True to indicate that a form of Beaujolais
3859 -- effect concerning library subprograms has been detected. Used to
3860 -- generate the precise error message.
3862 function From_Actual_Package (E : Entity_Id) return Boolean;
3863 -- Returns true if the entity is declared in a package that is
3864 -- an actual for a formal package of the current instance. Such an
3865 -- entity requires special handling because it may be use-visible
3866 -- but hides directly visible entities defined outside the instance.
3868 function Is_Actual_Parameter return Boolean;
3869 -- This function checks if the node N is an identifier that is an actual
3870 -- parameter of a procedure call. If so it returns True, otherwise it
3871 -- return False. The reason for this check is that at this stage we do
3872 -- not know what procedure is being called if the procedure might be
3873 -- overloaded, so it is premature to go setting referenced flags or
3874 -- making calls to Generate_Reference. We will wait till Resolve_Actuals
3875 -- for that processing
3877 function Known_But_Invisible (E : Entity_Id) return Boolean;
3878 -- This function determines whether the entity E (which is not
3879 -- visible) can reasonably be considered to be known to the writer
3880 -- of the reference. This is a heuristic test, used only for the
3881 -- purposes of figuring out whether we prefer to complain that an
3882 -- entity is undefined or invisible (and identify the declaration
3883 -- of the invisible entity in the latter case). The point here is
3884 -- that we don't want to complain that something is invisible and
3885 -- then point to something entirely mysterious to the writer.
3887 procedure Nvis_Messages;
3888 -- Called if there are no visible entries for N, but there is at least
3889 -- one non-directly visible, or hidden declaration. This procedure
3890 -- outputs an appropriate set of error messages.
3892 procedure Undefined (Nvis : Boolean);
3893 -- This function is called if the current node has no corresponding
3894 -- visible entity or entities. The value set in Msg indicates whether
3895 -- an error message was generated (multiple error messages for the
3896 -- same variable are generally suppressed, see body for details).
3897 -- Msg is True if an error message was generated, False if not. This
3898 -- value is used by the caller to determine whether or not to output
3899 -- additional messages where appropriate. The parameter is set False
3900 -- to get the message "X is undefined", and True to get the message
3901 -- "X is not visible".
3903 -------------------------
3904 -- From_Actual_Package --
3905 -------------------------
3907 function From_Actual_Package (E : Entity_Id) return Boolean is
3908 Scop : constant Entity_Id := Scope (E);
3912 if not In_Instance then
3915 Inst := Current_Scope;
3916 while Present (Inst)
3917 and then Ekind (Inst) /= E_Package
3918 and then not Is_Generic_Instance (Inst)
3920 Inst := Scope (Inst);
3927 Act := First_Entity (Inst);
3928 while Present (Act) loop
3929 if Ekind (Act) = E_Package then
3931 -- Check for end of actuals list
3933 if Renamed_Object (Act) = Inst then
3936 elsif Present (Associated_Formal_Package (Act))
3937 and then Renamed_Object (Act) = Scop
3939 -- Entity comes from (instance of) formal package
3954 end From_Actual_Package;
3956 -------------------------
3957 -- Is_Actual_Parameter --
3958 -------------------------
3960 function Is_Actual_Parameter return Boolean is
3963 Nkind (N) = N_Identifier
3965 (Nkind (Parent (N)) = N_Procedure_Call_Statement
3967 (Nkind (Parent (N)) = N_Parameter_Association
3968 and then N = Explicit_Actual_Parameter (Parent (N))
3969 and then Nkind (Parent (Parent (N))) =
3970 N_Procedure_Call_Statement));
3971 end Is_Actual_Parameter;
3973 -------------------------
3974 -- Known_But_Invisible --
3975 -------------------------
3977 function Known_But_Invisible (E : Entity_Id) return Boolean is
3978 Fname : File_Name_Type;
3981 -- Entities in Standard are always considered to be known
3983 if Sloc (E) <= Standard_Location then
3986 -- An entity that does not come from source is always considered
3987 -- to be unknown, since it is an artifact of code expansion.
3989 elsif not Comes_From_Source (E) then
3992 -- In gnat internal mode, we consider all entities known
3994 elsif GNAT_Mode then
3998 -- Here we have an entity that is not from package Standard, and
3999 -- which comes from Source. See if it comes from an internal file.
4001 Fname := Unit_File_Name (Get_Source_Unit (E));
4003 -- Case of from internal file
4005 if Is_Internal_File_Name (Fname) then
4007 -- Private part entities in internal files are never considered
4008 -- to be known to the writer of normal application code.
4010 if Is_Hidden (E) then
4014 -- Entities from System packages other than System and
4015 -- System.Storage_Elements are not considered to be known.
4016 -- System.Auxxxx files are also considered known to the user.
4018 -- Should refine this at some point to generally distinguish
4019 -- between known and unknown internal files ???
4021 Get_Name_String (Fname);
4026 Name_Buffer (1 .. 2) /= "s-"
4028 Name_Buffer (3 .. 8) = "stoele"
4030 Name_Buffer (3 .. 5) = "aux";
4032 -- If not an internal file, then entity is definitely known,
4033 -- even if it is in a private part (the message generated will
4034 -- note that it is in a private part)
4039 end Known_But_Invisible;
4045 procedure Nvis_Messages is
4046 Comp_Unit : Node_Id;
4048 Found : Boolean := False;
4049 Hidden : Boolean := False;
4053 -- Ada 2005 (AI-262): Generate a precise error concerning the
4054 -- Beaujolais effect that was previously detected
4056 if Nvis_Is_Private_Subprg then
4058 pragma Assert (Nkind (E2) = N_Defining_Identifier
4059 and then Ekind (E2) = E_Function
4060 and then Scope (E2) = Standard_Standard
4061 and then Has_Private_With (E2));
4063 -- Find the sloc corresponding to the private with'ed unit
4065 Comp_Unit := Cunit (Current_Sem_Unit);
4066 Error_Msg_Sloc := No_Location;
4068 Item := First (Context_Items (Comp_Unit));
4069 while Present (Item) loop
4070 if Nkind (Item) = N_With_Clause
4071 and then Private_Present (Item)
4072 and then Entity (Name (Item)) = E2
4074 Error_Msg_Sloc := Sloc (Item);
4081 pragma Assert (Error_Msg_Sloc /= No_Location);
4083 Error_Msg_N ("(Ada 2005): hidden by private with clause #", N);
4087 Undefined (Nvis => True);
4091 -- First loop does hidden declarations
4094 while Present (Ent) loop
4095 if Is_Potentially_Use_Visible (Ent) then
4097 Error_Msg_N -- CODEFIX
4098 ("multiple use clauses cause hiding!", N);
4102 Error_Msg_Sloc := Sloc (Ent);
4103 Error_Msg_N -- CODEFIX
4104 ("hidden declaration#!", N);
4107 Ent := Homonym (Ent);
4110 -- If we found hidden declarations, then that's enough, don't
4111 -- bother looking for non-visible declarations as well.
4117 -- Second loop does non-directly visible declarations
4120 while Present (Ent) loop
4121 if not Is_Potentially_Use_Visible (Ent) then
4123 -- Do not bother the user with unknown entities
4125 if not Known_But_Invisible (Ent) then
4129 Error_Msg_Sloc := Sloc (Ent);
4131 -- Output message noting that there is a non-visible
4132 -- declaration, distinguishing the private part case.
4134 if Is_Hidden (Ent) then
4135 Error_Msg_N ("non-visible (private) declaration#!", N);
4137 -- If the entity is declared in a generic package, it
4138 -- cannot be visible, so there is no point in adding it
4139 -- to the list of candidates if another homograph from a
4140 -- non-generic package has been seen.
4142 elsif Ekind (Scope (Ent)) = E_Generic_Package
4148 Error_Msg_N -- CODEFIX
4149 ("non-visible declaration#!", N);
4151 if Ekind (Scope (Ent)) /= E_Generic_Package then
4155 if Is_Compilation_Unit (Ent)
4157 Nkind (Parent (Parent (N))) = N_Use_Package_Clause
4159 Error_Msg_Qual_Level := 99;
4160 Error_Msg_NE -- CODEFIX
4161 ("\\missing `WITH &;`", N, Ent);
4162 Error_Msg_Qual_Level := 0;
4165 if Ekind (Ent) = E_Discriminant
4166 and then Present (Corresponding_Discriminant (Ent))
4167 and then Scope (Corresponding_Discriminant (Ent)) =
4171 ("inherited discriminant not allowed here" &
4172 " (RM 3.8 (12), 3.8.1 (6))!", N);
4176 -- Set entity and its containing package as referenced. We
4177 -- can't be sure of this, but this seems a better choice
4178 -- to avoid unused entity messages.
4180 if Comes_From_Source (Ent) then
4181 Set_Referenced (Ent);
4182 Set_Referenced (Cunit_Entity (Get_Source_Unit (Ent)));
4187 Ent := Homonym (Ent);
4196 procedure Undefined (Nvis : Boolean) is
4197 Emsg : Error_Msg_Id;
4200 -- We should never find an undefined internal name. If we do, then
4201 -- see if we have previous errors. If so, ignore on the grounds that
4202 -- it is probably a cascaded message (e.g. a block label from a badly
4203 -- formed block). If no previous errors, then we have a real internal
4204 -- error of some kind so raise an exception.
4206 if Is_Internal_Name (Chars (N)) then
4207 if Total_Errors_Detected /= 0 then
4210 raise Program_Error;
4214 -- A very specialized error check, if the undefined variable is
4215 -- a case tag, and the case type is an enumeration type, check
4216 -- for a possible misspelling, and if so, modify the identifier
4218 -- Named aggregate should also be handled similarly ???
4220 if Nkind (N) = N_Identifier
4221 and then Nkind (Parent (N)) = N_Case_Statement_Alternative
4224 Case_Stm : constant Node_Id := Parent (Parent (N));
4225 Case_Typ : constant Entity_Id := Etype (Expression (Case_Stm));
4230 if Is_Enumeration_Type (Case_Typ)
4231 and then not Is_Standard_Character_Type (Case_Typ)
4233 Lit := First_Literal (Case_Typ);
4234 Get_Name_String (Chars (Lit));
4236 if Chars (Lit) /= Chars (N)
4237 and then Is_Bad_Spelling_Of (Chars (N), Chars (Lit)) then
4238 Error_Msg_Node_2 := Lit;
4239 Error_Msg_N -- CODEFIX
4240 ("& is undefined, assume misspelling of &", N);
4241 Rewrite (N, New_Occurrence_Of (Lit, Sloc (N)));
4245 Lit := Next_Literal (Lit);
4250 -- Normal processing
4252 Set_Entity (N, Any_Id);
4253 Set_Etype (N, Any_Type);
4255 -- We use the table Urefs to keep track of entities for which we
4256 -- have issued errors for undefined references. Multiple errors
4257 -- for a single name are normally suppressed, however we modify
4258 -- the error message to alert the programmer to this effect.
4260 for J in Urefs.First .. Urefs.Last loop
4261 if Chars (N) = Chars (Urefs.Table (J).Node) then
4262 if Urefs.Table (J).Err /= No_Error_Msg
4263 and then Sloc (N) /= Urefs.Table (J).Loc
4265 Error_Msg_Node_1 := Urefs.Table (J).Node;
4267 if Urefs.Table (J).Nvis then
4268 Change_Error_Text (Urefs.Table (J).Err,
4269 "& is not visible (more references follow)");
4271 Change_Error_Text (Urefs.Table (J).Err,
4272 "& is undefined (more references follow)");
4275 Urefs.Table (J).Err := No_Error_Msg;
4278 -- Although we will set Msg False, and thus suppress the
4279 -- message, we also set Error_Posted True, to avoid any
4280 -- cascaded messages resulting from the undefined reference.
4283 Set_Error_Posted (N, True);
4288 -- If entry not found, this is first undefined occurrence
4291 Error_Msg_N ("& is not visible!", N);
4295 Error_Msg_N ("& is undefined!", N);
4298 -- A very bizarre special check, if the undefined identifier
4299 -- is put or put_line, then add a special error message (since
4300 -- this is a very common error for beginners to make).
4302 if Chars (N) = Name_Put or else Chars (N) = Name_Put_Line then
4303 Error_Msg_N -- CODEFIX
4304 ("\\possible missing `WITH Ada.Text_'I'O; " &
4305 "USE Ada.Text_'I'O`!", N);
4307 -- Another special check if N is the prefix of a selected
4308 -- component which is a known unit, add message complaining
4309 -- about missing with for this unit.
4311 elsif Nkind (Parent (N)) = N_Selected_Component
4312 and then N = Prefix (Parent (N))
4313 and then Is_Known_Unit (Parent (N))
4315 Error_Msg_Node_2 := Selector_Name (Parent (N));
4316 Error_Msg_N -- CODEFIX
4317 ("\\missing `WITH &.&;`", Prefix (Parent (N)));
4320 -- Now check for possible misspellings
4324 Ematch : Entity_Id := Empty;
4326 Last_Name_Id : constant Name_Id :=
4327 Name_Id (Nat (First_Name_Id) +
4328 Name_Entries_Count - 1);
4331 for Nam in First_Name_Id .. Last_Name_Id loop
4332 E := Get_Name_Entity_Id (Nam);
4335 and then (Is_Immediately_Visible (E)
4337 Is_Potentially_Use_Visible (E))
4339 if Is_Bad_Spelling_Of (Chars (N), Nam) then
4346 if Present (Ematch) then
4347 Error_Msg_NE -- CODEFIX
4348 ("\possible misspelling of&", N, Ematch);
4353 -- Make entry in undefined references table unless the full errors
4354 -- switch is set, in which case by refraining from generating the
4355 -- table entry, we guarantee that we get an error message for every
4356 -- undefined reference.
4358 if not All_Errors_Mode then
4369 -- Start of processing for Find_Direct_Name
4372 -- If the entity pointer is already set, this is an internal node, or
4373 -- a node that is analyzed more than once, after a tree modification.
4374 -- In such a case there is no resolution to perform, just set the type.
4376 if Present (Entity (N)) then
4377 if Is_Type (Entity (N)) then
4378 Set_Etype (N, Entity (N));
4382 Entyp : constant Entity_Id := Etype (Entity (N));
4385 -- One special case here. If the Etype field is already set,
4386 -- and references the packed array type corresponding to the
4387 -- etype of the referenced entity, then leave it alone. This
4388 -- happens for trees generated from Exp_Pakd, where expressions
4389 -- can be deliberately "mis-typed" to the packed array type.
4391 if Is_Array_Type (Entyp)
4392 and then Is_Packed (Entyp)
4393 and then Present (Etype (N))
4394 and then Etype (N) = Packed_Array_Type (Entyp)
4398 -- If not that special case, then just reset the Etype
4401 Set_Etype (N, Etype (Entity (N)));
4409 -- Here if Entity pointer was not set, we need full visibility analysis
4410 -- First we generate debugging output if the debug E flag is set.
4412 if Debug_Flag_E then
4413 Write_Str ("Looking for ");
4414 Write_Name (Chars (N));
4418 Homonyms := Current_Entity (N);
4419 Nvis_Entity := False;
4422 while Present (E) loop
4424 -- If entity is immediately visible or potentially use visible, then
4425 -- process the entity and we are done.
4427 if Is_Immediately_Visible (E) then
4428 goto Immediately_Visible_Entity;
4430 elsif Is_Potentially_Use_Visible (E) then
4431 goto Potentially_Use_Visible_Entity;
4433 -- Note if a known but invisible entity encountered
4435 elsif Known_But_Invisible (E) then
4436 Nvis_Entity := True;
4439 -- Move to next entity in chain and continue search
4444 -- If no entries on homonym chain that were potentially visible,
4445 -- and no entities reasonably considered as non-visible, then
4446 -- we have a plain undefined reference, with no additional
4447 -- explanation required!
4449 if not Nvis_Entity then
4450 Undefined (Nvis => False);
4452 -- Otherwise there is at least one entry on the homonym chain that
4453 -- is reasonably considered as being known and non-visible.
4461 -- Processing for a potentially use visible entry found. We must search
4462 -- the rest of the homonym chain for two reasons. First, if there is a
4463 -- directly visible entry, then none of the potentially use-visible
4464 -- entities are directly visible (RM 8.4(10)). Second, we need to check
4465 -- for the case of multiple potentially use-visible entries hiding one
4466 -- another and as a result being non-directly visible (RM 8.4(11)).
4468 <<Potentially_Use_Visible_Entity>> declare
4469 Only_One_Visible : Boolean := True;
4470 All_Overloadable : Boolean := Is_Overloadable (E);
4474 while Present (E2) loop
4475 if Is_Immediately_Visible (E2) then
4477 -- If the use-visible entity comes from the actual for a
4478 -- formal package, it hides a directly visible entity from
4479 -- outside the instance.
4481 if From_Actual_Package (E)
4482 and then Scope_Depth (E2) < Scope_Depth (Inst)
4487 goto Immediately_Visible_Entity;
4490 elsif Is_Potentially_Use_Visible (E2) then
4491 Only_One_Visible := False;
4492 All_Overloadable := All_Overloadable and Is_Overloadable (E2);
4494 -- Ada 2005 (AI-262): Protect against a form of Beaujolais effect
4495 -- that can occur in private_with clauses. Example:
4498 -- private with B; package A is
4499 -- package C is function B return Integer;
4501 -- V1 : Integer := B;
4502 -- private function B return Integer;
4503 -- V2 : Integer := B;
4506 -- V1 resolves to A.B, but V2 resolves to library unit B
4508 elsif Ekind (E2) = E_Function
4509 and then Scope (E2) = Standard_Standard
4510 and then Has_Private_With (E2)
4512 Only_One_Visible := False;
4513 All_Overloadable := False;
4514 Nvis_Is_Private_Subprg := True;
4521 -- On falling through this loop, we have checked that there are no
4522 -- immediately visible entities. Only_One_Visible is set if exactly
4523 -- one potentially use visible entity exists. All_Overloadable is
4524 -- set if all the potentially use visible entities are overloadable.
4525 -- The condition for legality is that either there is one potentially
4526 -- use visible entity, or if there is more than one, then all of them
4527 -- are overloadable.
4529 if Only_One_Visible or All_Overloadable then
4532 -- If there is more than one potentially use-visible entity and at
4533 -- least one of them non-overloadable, we have an error (RM 8.4(11).
4534 -- Note that E points to the first such entity on the homonym list.
4535 -- Special case: if one of the entities is declared in an actual
4536 -- package, it was visible in the generic, and takes precedence over
4537 -- other entities that are potentially use-visible. Same if it is
4538 -- declared in a local instantiation of the current instance.
4543 -- Find current instance
4545 Inst := Current_Scope;
4546 while Present (Inst)
4547 and then Inst /= Standard_Standard
4549 if Is_Generic_Instance (Inst) then
4553 Inst := Scope (Inst);
4557 while Present (E2) loop
4558 if From_Actual_Package (E2)
4560 (Is_Generic_Instance (Scope (E2))
4561 and then Scope_Depth (Scope (E2)) > Scope_Depth (Inst))
4574 Is_Predefined_File_Name (Unit_File_Name (Current_Sem_Unit))
4576 -- A use-clause in the body of a system file creates conflict
4577 -- with some entity in a user scope, while rtsfind is active.
4578 -- Keep only the entity coming from another predefined unit.
4581 while Present (E2) loop
4582 if Is_Predefined_File_Name
4583 (Unit_File_Name (Get_Source_Unit (Sloc (E2))))
4592 -- Entity must exist because predefined unit is correct
4594 raise Program_Error;
4603 -- Come here with E set to the first immediately visible entity on
4604 -- the homonym chain. This is the one we want unless there is another
4605 -- immediately visible entity further on in the chain for an inner
4606 -- scope (RM 8.3(8)).
4608 <<Immediately_Visible_Entity>> declare
4613 -- Find scope level of initial entity. When compiling through
4614 -- Rtsfind, the previous context is not completely invisible, and
4615 -- an outer entity may appear on the chain, whose scope is below
4616 -- the entry for Standard that delimits the current scope stack.
4617 -- Indicate that the level for this spurious entry is outside of
4618 -- the current scope stack.
4620 Level := Scope_Stack.Last;
4622 Scop := Scope_Stack.Table (Level).Entity;
4623 exit when Scop = Scope (E);
4625 exit when Scop = Standard_Standard;
4628 -- Now search remainder of homonym chain for more inner entry
4629 -- If the entity is Standard itself, it has no scope, and we
4630 -- compare it with the stack entry directly.
4633 while Present (E2) loop
4634 if Is_Immediately_Visible (E2) then
4636 -- If a generic package contains a local declaration that
4637 -- has the same name as the generic, there may be a visibility
4638 -- conflict in an instance, where the local declaration must
4639 -- also hide the name of the corresponding package renaming.
4640 -- We check explicitly for a package declared by a renaming,
4641 -- whose renamed entity is an instance that is on the scope
4642 -- stack, and that contains a homonym in the same scope. Once
4643 -- we have found it, we know that the package renaming is not
4644 -- immediately visible, and that the identifier denotes the
4645 -- other entity (and its homonyms if overloaded).
4647 if Scope (E) = Scope (E2)
4648 and then Ekind (E) = E_Package
4649 and then Present (Renamed_Object (E))
4650 and then Is_Generic_Instance (Renamed_Object (E))
4651 and then In_Open_Scopes (Renamed_Object (E))
4652 and then Comes_From_Source (N)
4654 Set_Is_Immediately_Visible (E, False);
4658 for J in Level + 1 .. Scope_Stack.Last loop
4659 if Scope_Stack.Table (J).Entity = Scope (E2)
4660 or else Scope_Stack.Table (J).Entity = E2
4673 -- At the end of that loop, E is the innermost immediately
4674 -- visible entity, so we are all set.
4677 -- Come here with entity found, and stored in E
4681 -- Check violation of No_Wide_Characters restriction
4683 Check_Wide_Character_Restriction (E, N);
4685 -- When distribution features are available (Get_PCS_Name /=
4686 -- Name_No_DSA), a remote access-to-subprogram type is converted
4687 -- into a record type holding whatever information is needed to
4688 -- perform a remote call on an RCI subprogram. In that case we
4689 -- rewrite any occurrence of the RAS type into the equivalent record
4690 -- type here. 'Access attribute references and RAS dereferences are
4691 -- then implemented using specific TSSs. However when distribution is
4692 -- not available (case of Get_PCS_Name = Name_No_DSA), we bypass the
4693 -- generation of these TSSs, and we must keep the RAS type in its
4694 -- original access-to-subprogram form (since all calls through a
4695 -- value of such type will be local anyway in the absence of a PCS).
4697 if Comes_From_Source (N)
4698 and then Is_Remote_Access_To_Subprogram_Type (E)
4699 and then Expander_Active
4700 and then Get_PCS_Name /= Name_No_DSA
4703 New_Occurrence_Of (Equivalent_Type (E), Sloc (N)));
4707 -- Set the entity. Note that the reason we call Set_Entity for the
4708 -- overloadable case, as opposed to Set_Entity_With_Style_Check is
4709 -- that in the overloaded case, the initial call can set the wrong
4710 -- homonym. The call that sets the right homonym is in Sem_Res and
4711 -- that call does use Set_Entity_With_Style_Check, so we don't miss
4714 if Is_Overloadable (E) then
4717 Set_Entity_With_Style_Check (N, E);
4723 Set_Etype (N, Get_Full_View (Etype (E)));
4726 if Debug_Flag_E then
4727 Write_Str (" found ");
4728 Write_Entity_Info (E, " ");
4731 -- If the Ekind of the entity is Void, it means that all homonyms
4732 -- are hidden from all visibility (RM 8.3(5,14-20)). However, this
4733 -- test is skipped if the current scope is a record and the name is
4734 -- a pragma argument expression (case of Atomic and Volatile pragmas
4735 -- and possibly other similar pragmas added later, which are allowed
4736 -- to reference components in the current record).
4738 if Ekind (E) = E_Void
4740 (not Is_Record_Type (Current_Scope)
4741 or else Nkind (Parent (N)) /= N_Pragma_Argument_Association)
4743 Premature_Usage (N);
4745 -- If the entity is overloadable, collect all interpretations of the
4746 -- name for subsequent overload resolution. We optimize a bit here to
4747 -- do this only if we have an overloadable entity that is not on its
4748 -- own on the homonym chain.
4750 elsif Is_Overloadable (E)
4751 and then (Present (Homonym (E)) or else Current_Entity (N) /= E)
4753 Collect_Interps (N);
4755 -- If no homonyms were visible, the entity is unambiguous
4757 if not Is_Overloaded (N) then
4758 if not Is_Actual_Parameter then
4759 Generate_Reference (E, N);
4763 -- Case of non-overloadable entity, set the entity providing that
4764 -- we do not have the case of a discriminant reference within a
4765 -- default expression. Such references are replaced with the
4766 -- corresponding discriminal, which is the formal corresponding to
4767 -- to the discriminant in the initialization procedure.
4770 -- Entity is unambiguous, indicate that it is referenced here
4772 -- For a renaming of an object, always generate simple reference,
4773 -- we don't try to keep track of assignments in this case.
4775 if Is_Object (E) and then Present (Renamed_Object (E)) then
4776 Generate_Reference (E, N);
4778 -- If the renamed entity is a private protected component,
4779 -- reference the original component as well. This needs to be
4780 -- done because the private renamings are installed before any
4781 -- analysis has occurred. Reference to a private component will
4782 -- resolve to the renaming and the original component will be
4783 -- left unreferenced, hence the following.
4785 if Is_Prival (E) then
4786 Generate_Reference (Prival_Link (E), N);
4789 -- One odd case is that we do not want to set the Referenced flag
4790 -- if the entity is a label, and the identifier is the label in
4791 -- the source, since this is not a reference from the point of
4792 -- view of the user.
4794 elsif Nkind (Parent (N)) = N_Label then
4796 R : constant Boolean := Referenced (E);
4799 -- Generate reference unless this is an actual parameter
4800 -- (see comment below)
4802 if Is_Actual_Parameter then
4803 Generate_Reference (E, N);
4804 Set_Referenced (E, R);
4808 -- Normal case, not a label: generate reference
4810 -- ??? It is too early to generate a reference here even if the
4811 -- entity is unambiguous, because the tree is not sufficiently
4812 -- typed at this point for Generate_Reference to determine
4813 -- whether this reference modifies the denoted object (because
4814 -- implicit dereferences cannot be identified prior to full type
4817 -- The Is_Actual_Parameter routine takes care of one of these
4818 -- cases but there are others probably ???
4820 -- If the entity is the LHS of an assignment, and is a variable
4821 -- (rather than a package prefix), we can mark it as a
4822 -- modification right away, to avoid duplicate references.
4825 if not Is_Actual_Parameter then
4827 and then Ekind (E) /= E_Package
4828 and then Ekind (E) /= E_Generic_Package
4830 Generate_Reference (E, N, 'm');
4832 Generate_Reference (E, N);
4836 Check_Nested_Access (E);
4839 Set_Entity_Or_Discriminal (N, E);
4841 if Ada_Version >= Ada_2012
4842 and then Nkind (Parent (N)) in N_Subexpr
4844 Check_Implicit_Dereference (N, Etype (E));
4848 end Find_Direct_Name;
4850 ------------------------
4851 -- Find_Expanded_Name --
4852 ------------------------
4854 -- This routine searches the homonym chain of the entity until it finds
4855 -- an entity declared in the scope denoted by the prefix. If the entity
4856 -- is private, it may nevertheless be immediately visible, if we are in
4857 -- the scope of its declaration.
4859 procedure Find_Expanded_Name (N : Node_Id) is
4860 Selector : constant Node_Id := Selector_Name (N);
4861 Candidate : Entity_Id := Empty;
4867 P_Name := Entity (Prefix (N));
4870 -- If the prefix is a renamed package, look for the entity in the
4871 -- original package.
4873 if Ekind (P_Name) = E_Package
4874 and then Present (Renamed_Object (P_Name))
4876 P_Name := Renamed_Object (P_Name);
4878 -- Rewrite node with entity field pointing to renamed object
4880 Rewrite (Prefix (N), New_Copy (Prefix (N)));
4881 Set_Entity (Prefix (N), P_Name);
4883 -- If the prefix is an object of a concurrent type, look for
4884 -- the entity in the associated task or protected type.
4886 elsif Is_Concurrent_Type (Etype (P_Name)) then
4887 P_Name := Etype (P_Name);
4890 Id := Current_Entity (Selector);
4893 Is_New_Candidate : Boolean;
4896 while Present (Id) loop
4897 if Scope (Id) = P_Name then
4899 Is_New_Candidate := True;
4901 -- Ada 2005 (AI-217): Handle shadow entities associated with types
4902 -- declared in limited-withed nested packages. We don't need to
4903 -- handle E_Incomplete_Subtype entities because the entities in
4904 -- the limited view are always E_Incomplete_Type entities (see
4905 -- Build_Limited_Views). Regarding the expression used to evaluate
4906 -- the scope, it is important to note that the limited view also
4907 -- has shadow entities associated nested packages. For this reason
4908 -- the correct scope of the entity is the scope of the real entity
4909 -- The non-limited view may itself be incomplete, in which case
4910 -- get the full view if available.
4912 elsif From_With_Type (Id)
4913 and then Is_Type (Id)
4914 and then Ekind (Id) = E_Incomplete_Type
4915 and then Present (Non_Limited_View (Id))
4916 and then Scope (Non_Limited_View (Id)) = P_Name
4918 Candidate := Get_Full_View (Non_Limited_View (Id));
4919 Is_New_Candidate := True;
4922 Is_New_Candidate := False;
4925 if Is_New_Candidate then
4926 if Is_Child_Unit (Id) then
4927 exit when Is_Visible_Child_Unit (Id)
4928 or else Is_Immediately_Visible (Id);
4931 exit when not Is_Hidden (Id)
4932 or else Is_Immediately_Visible (Id);
4941 and then (Ekind (P_Name) = E_Procedure
4943 Ekind (P_Name) = E_Function)
4944 and then Is_Generic_Instance (P_Name)
4946 -- Expanded name denotes entity in (instance of) generic subprogram.
4947 -- The entity may be in the subprogram instance, or may denote one of
4948 -- the formals, which is declared in the enclosing wrapper package.
4950 P_Name := Scope (P_Name);
4952 Id := Current_Entity (Selector);
4953 while Present (Id) loop
4954 exit when Scope (Id) = P_Name;
4959 if No (Id) or else Chars (Id) /= Chars (Selector) then
4960 Set_Etype (N, Any_Type);
4962 -- If we are looking for an entity defined in System, try to find it
4963 -- in the child package that may have been provided as an extension
4964 -- to System. The Extend_System pragma will have supplied the name of
4965 -- the extension, which may have to be loaded.
4967 if Chars (P_Name) = Name_System
4968 and then Scope (P_Name) = Standard_Standard
4969 and then Present (System_Extend_Unit)
4970 and then Present_System_Aux (N)
4972 Set_Entity (Prefix (N), System_Aux_Id);
4973 Find_Expanded_Name (N);
4976 elsif Nkind (Selector) = N_Operator_Symbol
4977 and then Has_Implicit_Operator (N)
4979 -- There is an implicit instance of the predefined operator in
4980 -- the given scope. The operator entity is defined in Standard.
4981 -- Has_Implicit_Operator makes the node into an Expanded_Name.
4985 elsif Nkind (Selector) = N_Character_Literal
4986 and then Has_Implicit_Character_Literal (N)
4988 -- If there is no literal defined in the scope denoted by the
4989 -- prefix, the literal may belong to (a type derived from)
4990 -- Standard_Character, for which we have no explicit literals.
4995 -- If the prefix is a single concurrent object, use its name in
4996 -- the error message, rather than that of the anonymous type.
4998 if Is_Concurrent_Type (P_Name)
4999 and then Is_Internal_Name (Chars (P_Name))
5001 Error_Msg_Node_2 := Entity (Prefix (N));
5003 Error_Msg_Node_2 := P_Name;
5006 if P_Name = System_Aux_Id then
5007 P_Name := Scope (P_Name);
5008 Set_Entity (Prefix (N), P_Name);
5011 if Present (Candidate) then
5013 -- If we know that the unit is a child unit we can give a more
5014 -- accurate error message.
5016 if Is_Child_Unit (Candidate) then
5018 -- If the candidate is a private child unit and we are in
5019 -- the visible part of a public unit, specialize the error
5020 -- message. There might be a private with_clause for it,
5021 -- but it is not currently active.
5023 if Is_Private_Descendant (Candidate)
5024 and then Ekind (Current_Scope) = E_Package
5025 and then not In_Private_Part (Current_Scope)
5026 and then not Is_Private_Descendant (Current_Scope)
5028 Error_Msg_N ("private child unit& is not visible here",
5031 -- Normal case where we have a missing with for a child unit
5034 Error_Msg_Qual_Level := 99;
5035 Error_Msg_NE -- CODEFIX
5036 ("missing `WITH &;`", Selector, Candidate);
5037 Error_Msg_Qual_Level := 0;
5040 -- Here we don't know that this is a child unit
5043 Error_Msg_NE ("& is not a visible entity of&", N, Selector);
5047 -- Within the instantiation of a child unit, the prefix may
5048 -- denote the parent instance, but the selector has the name
5049 -- of the original child. Find whether we are within the
5050 -- corresponding instance, and get the proper entity, which
5051 -- can only be an enclosing scope.
5054 and then In_Open_Scopes (P_Name)
5055 and then Is_Generic_Instance (P_Name)
5058 S : Entity_Id := Current_Scope;
5062 for J in reverse 0 .. Scope_Stack.Last loop
5063 S := Scope_Stack.Table (J).Entity;
5065 exit when S = Standard_Standard;
5067 if Ekind_In (S, E_Function,
5071 P := Generic_Parent (Specification
5072 (Unit_Declaration_Node (S)));
5075 and then Chars (Scope (P)) = Chars (O_Name)
5076 and then Chars (P) = Chars (Selector)
5087 -- If this is a selection from Ada, System or Interfaces, then
5088 -- we assume a missing with for the corresponding package.
5090 if Is_Known_Unit (N) then
5091 if not Error_Posted (N) then
5092 Error_Msg_Node_2 := Selector;
5093 Error_Msg_N -- CODEFIX
5094 ("missing `WITH &.&;`", Prefix (N));
5097 -- If this is a selection from a dummy package, then suppress
5098 -- the error message, of course the entity is missing if the
5099 -- package is missing!
5101 elsif Sloc (Error_Msg_Node_2) = No_Location then
5104 -- Here we have the case of an undefined component
5108 -- The prefix may hide a homonym in the context that
5109 -- declares the desired entity. This error can use a
5110 -- specialized message.
5112 if In_Open_Scopes (P_Name)
5113 and then Present (Homonym (P_Name))
5114 and then Is_Compilation_Unit (Homonym (P_Name))
5116 (Is_Immediately_Visible (Homonym (P_Name))
5117 or else Is_Visible_Child_Unit (Homonym (P_Name)))
5120 H : constant Entity_Id := Homonym (P_Name);
5123 Id := First_Entity (H);
5124 while Present (Id) loop
5125 if Chars (Id) = Chars (Selector) then
5126 Error_Msg_Qual_Level := 99;
5127 Error_Msg_Name_1 := Chars (Selector);
5129 ("% not declared in&", N, P_Name);
5131 ("\use fully qualified name starting with"
5132 & " Standard to make& visible", N, H);
5133 Error_Msg_Qual_Level := 0;
5140 -- If not found, standard error message.
5142 Error_Msg_NE ("& not declared in&", N, Selector);
5148 Error_Msg_NE ("& not declared in&", N, Selector);
5151 -- Check for misspelling of some entity in prefix
5153 Id := First_Entity (P_Name);
5154 while Present (Id) loop
5155 if Is_Bad_Spelling_Of (Chars (Id), Chars (Selector))
5156 and then not Is_Internal_Name (Chars (Id))
5158 Error_Msg_NE -- CODEFIX
5159 ("possible misspelling of&", Selector, Id);
5166 -- Specialize the message if this may be an instantiation
5167 -- of a child unit that was not mentioned in the context.
5169 if Nkind (Parent (N)) = N_Package_Instantiation
5170 and then Is_Generic_Instance (Entity (Prefix (N)))
5171 and then Is_Compilation_Unit
5172 (Generic_Parent (Parent (Entity (Prefix (N)))))
5174 Error_Msg_Node_2 := Selector;
5175 Error_Msg_N -- CODEFIX
5176 ("\missing `WITH &.&;`", Prefix (N));
5186 if Comes_From_Source (N)
5187 and then Is_Remote_Access_To_Subprogram_Type (Id)
5188 and then Present (Equivalent_Type (Id))
5190 -- If we are not actually generating distribution code (i.e. the
5191 -- current PCS is the dummy non-distributed version), then the
5192 -- Equivalent_Type will be missing, and Id should be treated as
5193 -- a regular access-to-subprogram type.
5195 Id := Equivalent_Type (Id);
5196 Set_Chars (Selector, Chars (Id));
5199 -- Ada 2005 (AI-50217): Check usage of entities in limited withed units
5201 if Ekind (P_Name) = E_Package
5202 and then From_With_Type (P_Name)
5204 if From_With_Type (Id)
5205 or else Is_Type (Id)
5206 or else Ekind (Id) = E_Package
5211 ("limited withed package can only be used to access "
5212 & "incomplete types",
5217 if Is_Task_Type (P_Name)
5218 and then ((Ekind (Id) = E_Entry
5219 and then Nkind (Parent (N)) /= N_Attribute_Reference)
5221 (Ekind (Id) = E_Entry_Family
5223 Nkind (Parent (Parent (N))) /= N_Attribute_Reference))
5225 -- It is an entry call after all, either to the current task (which
5226 -- will deadlock) or to an enclosing task.
5228 Analyze_Selected_Component (N);
5232 Change_Selected_Component_To_Expanded_Name (N);
5234 -- Do style check and generate reference, but skip both steps if this
5235 -- entity has homonyms, since we may not have the right homonym set yet.
5236 -- The proper homonym will be set during the resolve phase.
5238 if Has_Homonym (Id) then
5241 Set_Entity_Or_Discriminal (N, Id);
5244 Generate_Reference (Id, N, 'm');
5246 Generate_Reference (Id, N);
5250 if Is_Type (Id) then
5253 Set_Etype (N, Get_Full_View (Etype (Id)));
5256 -- Check for violation of No_Wide_Characters
5258 Check_Wide_Character_Restriction (Id, N);
5260 -- If the Ekind of the entity is Void, it means that all homonyms are
5261 -- hidden from all visibility (RM 8.3(5,14-20)).
5263 if Ekind (Id) = E_Void then
5264 Premature_Usage (N);
5266 elsif Is_Overloadable (Id)
5267 and then Present (Homonym (Id))
5270 H : Entity_Id := Homonym (Id);
5273 while Present (H) loop
5274 if Scope (H) = Scope (Id)
5277 or else Is_Immediately_Visible (H))
5279 Collect_Interps (N);
5286 -- If an extension of System is present, collect possible explicit
5287 -- overloadings declared in the extension.
5289 if Chars (P_Name) = Name_System
5290 and then Scope (P_Name) = Standard_Standard
5291 and then Present (System_Extend_Unit)
5292 and then Present_System_Aux (N)
5294 H := Current_Entity (Id);
5296 while Present (H) loop
5297 if Scope (H) = System_Aux_Id then
5298 Add_One_Interp (N, H, Etype (H));
5307 if Nkind (Selector_Name (N)) = N_Operator_Symbol
5308 and then Scope (Id) /= Standard_Standard
5310 -- In addition to user-defined operators in the given scope, there
5311 -- may be an implicit instance of the predefined operator. The
5312 -- operator (defined in Standard) is found in Has_Implicit_Operator,
5313 -- and added to the interpretations. Procedure Add_One_Interp will
5314 -- determine which hides which.
5316 if Has_Implicit_Operator (N) then
5320 end Find_Expanded_Name;
5322 -------------------------
5323 -- Find_Renamed_Entity --
5324 -------------------------
5326 function Find_Renamed_Entity
5330 Is_Actual : Boolean := False) return Entity_Id
5333 I1 : Interp_Index := 0; -- Suppress junk warnings
5339 function Enclosing_Instance return Entity_Id;
5340 -- If the renaming determines the entity for the default of a formal
5341 -- subprogram nested within another instance, choose the innermost
5342 -- candidate. This is because if the formal has a box, and we are within
5343 -- an enclosing instance where some candidate interpretations are local
5344 -- to this enclosing instance, we know that the default was properly
5345 -- resolved when analyzing the generic, so we prefer the local
5346 -- candidates to those that are external. This is not always the case
5347 -- but is a reasonable heuristic on the use of nested generics. The
5348 -- proper solution requires a full renaming model.
5350 function Is_Visible_Operation (Op : Entity_Id) return Boolean;
5351 -- If the renamed entity is an implicit operator, check whether it is
5352 -- visible because its operand type is properly visible. This check
5353 -- applies to explicit renamed entities that appear in the source in a
5354 -- renaming declaration or a formal subprogram instance, but not to
5355 -- default generic actuals with a name.
5357 function Report_Overload return Entity_Id;
5358 -- List possible interpretations, and specialize message in the
5359 -- case of a generic actual.
5361 function Within (Inner, Outer : Entity_Id) return Boolean;
5362 -- Determine whether a candidate subprogram is defined within the
5363 -- enclosing instance. If yes, it has precedence over outer candidates.
5365 ------------------------
5366 -- Enclosing_Instance --
5367 ------------------------
5369 function Enclosing_Instance return Entity_Id is
5373 if not Is_Generic_Instance (Current_Scope)
5374 and then not Is_Actual
5379 S := Scope (Current_Scope);
5380 while S /= Standard_Standard loop
5381 if Is_Generic_Instance (S) then
5389 end Enclosing_Instance;
5391 --------------------------
5392 -- Is_Visible_Operation --
5393 --------------------------
5395 function Is_Visible_Operation (Op : Entity_Id) return Boolean is
5401 if Ekind (Op) /= E_Operator
5402 or else Scope (Op) /= Standard_Standard
5403 or else (In_Instance
5406 or else Present (Enclosing_Instance)))
5411 -- For a fixed point type operator, check the resulting type,
5412 -- because it may be a mixed mode integer * fixed operation.
5414 if Present (Next_Formal (First_Formal (New_S)))
5415 and then Is_Fixed_Point_Type (Etype (New_S))
5417 Typ := Etype (New_S);
5419 Typ := Etype (First_Formal (New_S));
5422 Btyp := Base_Type (Typ);
5424 if Nkind (Nam) /= N_Expanded_Name then
5425 return (In_Open_Scopes (Scope (Btyp))
5426 or else Is_Potentially_Use_Visible (Btyp)
5427 or else In_Use (Btyp)
5428 or else In_Use (Scope (Btyp)));
5431 Scop := Entity (Prefix (Nam));
5433 if Ekind (Scop) = E_Package
5434 and then Present (Renamed_Object (Scop))
5436 Scop := Renamed_Object (Scop);
5439 -- Operator is visible if prefix of expanded name denotes
5440 -- scope of type, or else type is defined in System_Aux
5441 -- and the prefix denotes System.
5443 return Scope (Btyp) = Scop
5444 or else (Scope (Btyp) = System_Aux_Id
5445 and then Scope (Scope (Btyp)) = Scop);
5448 end Is_Visible_Operation;
5454 function Within (Inner, Outer : Entity_Id) return Boolean is
5458 Sc := Scope (Inner);
5459 while Sc /= Standard_Standard loop
5470 ---------------------
5471 -- Report_Overload --
5472 ---------------------
5474 function Report_Overload return Entity_Id is
5477 Error_Msg_NE -- CODEFIX
5478 ("ambiguous actual subprogram&, " &
5479 "possible interpretations:", N, Nam);
5481 Error_Msg_N -- CODEFIX
5482 ("ambiguous subprogram, " &
5483 "possible interpretations:", N);
5486 List_Interps (Nam, N);
5488 end Report_Overload;
5490 -- Start of processing for Find_Renamed_Entity
5494 Candidate_Renaming := Empty;
5496 if not Is_Overloaded (Nam) then
5497 if Entity_Matches_Spec (Entity (Nam), New_S) then
5498 Candidate_Renaming := New_S;
5500 if Is_Visible_Operation (Entity (Nam)) then
5501 Old_S := Entity (Nam);
5505 Present (First_Formal (Entity (Nam)))
5506 and then Present (First_Formal (New_S))
5507 and then (Base_Type (Etype (First_Formal (Entity (Nam))))
5508 = Base_Type (Etype (First_Formal (New_S))))
5510 Candidate_Renaming := Entity (Nam);
5514 Get_First_Interp (Nam, Ind, It);
5515 while Present (It.Nam) loop
5516 if Entity_Matches_Spec (It.Nam, New_S)
5517 and then Is_Visible_Operation (It.Nam)
5519 if Old_S /= Any_Id then
5521 -- Note: The call to Disambiguate only happens if a
5522 -- previous interpretation was found, in which case I1
5523 -- has received a value.
5525 It1 := Disambiguate (Nam, I1, Ind, Etype (Old_S));
5527 if It1 = No_Interp then
5528 Inst := Enclosing_Instance;
5530 if Present (Inst) then
5531 if Within (It.Nam, Inst) then
5533 elsif Within (Old_S, Inst) then
5536 return Report_Overload;
5540 return Report_Overload;
5554 Present (First_Formal (It.Nam))
5555 and then Present (First_Formal (New_S))
5556 and then (Base_Type (Etype (First_Formal (It.Nam)))
5557 = Base_Type (Etype (First_Formal (New_S))))
5559 Candidate_Renaming := It.Nam;
5562 Get_Next_Interp (Ind, It);
5565 Set_Entity (Nam, Old_S);
5567 if Old_S /= Any_Id then
5568 Set_Is_Overloaded (Nam, False);
5573 end Find_Renamed_Entity;
5575 -----------------------------
5576 -- Find_Selected_Component --
5577 -----------------------------
5579 procedure Find_Selected_Component (N : Node_Id) is
5580 P : constant Node_Id := Prefix (N);
5583 -- Entity denoted by prefix
5593 if Nkind (P) = N_Error then
5597 -- Selector name cannot be a character literal or an operator symbol in
5598 -- SPARK, except for the operator symbol in a renaming.
5600 if Restriction_Check_Required (SPARK) then
5601 if Nkind (Selector_Name (N)) = N_Character_Literal then
5602 Check_SPARK_Restriction
5603 ("character literal cannot be prefixed", N);
5604 elsif Nkind (Selector_Name (N)) = N_Operator_Symbol
5605 and then Nkind (Parent (N)) /= N_Subprogram_Renaming_Declaration
5607 Check_SPARK_Restriction ("operator symbol cannot be prefixed", N);
5611 -- If the selector already has an entity, the node has been constructed
5612 -- in the course of expansion, and is known to be valid. Do not verify
5613 -- that it is defined for the type (it may be a private component used
5614 -- in the expansion of record equality).
5616 if Present (Entity (Selector_Name (N))) then
5618 or else Etype (N) = Any_Type
5621 Sel_Name : constant Node_Id := Selector_Name (N);
5622 Selector : constant Entity_Id := Entity (Sel_Name);
5626 Set_Etype (Sel_Name, Etype (Selector));
5628 if not Is_Entity_Name (P) then
5632 -- Build an actual subtype except for the first parameter
5633 -- of an init proc, where this actual subtype is by
5634 -- definition incorrect, since the object is uninitialized
5635 -- (and does not even have defined discriminants etc.)
5637 if Is_Entity_Name (P)
5638 and then Ekind (Entity (P)) = E_Function
5640 Nam := New_Copy (P);
5642 if Is_Overloaded (P) then
5643 Save_Interps (P, Nam);
5647 Make_Function_Call (Sloc (P), Name => Nam));
5649 Analyze_Selected_Component (N);
5652 elsif Ekind (Selector) = E_Component
5653 and then (not Is_Entity_Name (P)
5654 or else Chars (Entity (P)) /= Name_uInit)
5656 -- Do not build the subtype when referencing components of
5657 -- dispatch table wrappers. Required to avoid generating
5658 -- elaboration code with HI runtimes. JVM and .NET use a
5659 -- modified version of Ada.Tags which does not contain RE_
5660 -- Dispatch_Table_Wrapper and RE_No_Dispatch_Table_Wrapper.
5661 -- Avoid raising RE_Not_Available exception in those cases.
5663 if VM_Target = No_VM
5664 and then RTU_Loaded (Ada_Tags)
5666 ((RTE_Available (RE_Dispatch_Table_Wrapper)
5667 and then Scope (Selector) =
5668 RTE (RE_Dispatch_Table_Wrapper))
5670 (RTE_Available (RE_No_Dispatch_Table_Wrapper)
5671 and then Scope (Selector) =
5672 RTE (RE_No_Dispatch_Table_Wrapper)))
5678 Build_Actual_Subtype_Of_Component
5679 (Etype (Selector), N);
5686 if No (C_Etype) then
5687 C_Etype := Etype (Selector);
5689 Insert_Action (N, C_Etype);
5690 C_Etype := Defining_Identifier (C_Etype);
5693 Set_Etype (N, C_Etype);
5696 -- If this is the name of an entry or protected operation, and
5697 -- the prefix is an access type, insert an explicit dereference,
5698 -- so that entry calls are treated uniformly.
5700 if Is_Access_Type (Etype (P))
5701 and then Is_Concurrent_Type (Designated_Type (Etype (P)))
5704 New_P : constant Node_Id :=
5705 Make_Explicit_Dereference (Sloc (P),
5706 Prefix => Relocate_Node (P));
5709 Set_Etype (P, Designated_Type (Etype (Prefix (P))));
5713 -- If the selected component appears within a default expression
5714 -- and it has an actual subtype, the pre-analysis has not yet
5715 -- completed its analysis, because Insert_Actions is disabled in
5716 -- that context. Within the init proc of the enclosing type we
5717 -- must complete this analysis, if an actual subtype was created.
5719 elsif Inside_Init_Proc then
5721 Typ : constant Entity_Id := Etype (N);
5722 Decl : constant Node_Id := Declaration_Node (Typ);
5724 if Nkind (Decl) = N_Subtype_Declaration
5725 and then not Analyzed (Decl)
5726 and then Is_List_Member (Decl)
5727 and then No (Parent (Decl))
5730 Insert_Action (N, Decl);
5737 elsif Is_Entity_Name (P) then
5738 P_Name := Entity (P);
5740 -- The prefix may denote an enclosing type which is the completion
5741 -- of an incomplete type declaration.
5743 if Is_Type (P_Name) then
5744 Set_Entity (P, Get_Full_View (P_Name));
5745 Set_Etype (P, Entity (P));
5746 P_Name := Entity (P);
5749 P_Type := Base_Type (Etype (P));
5751 if Debug_Flag_E then
5752 Write_Str ("Found prefix type to be ");
5753 Write_Entity_Info (P_Type, " "); Write_Eol;
5756 -- First check for components of a record object (not the
5757 -- result of a call, which is handled below).
5759 if Is_Appropriate_For_Record (P_Type)
5760 and then not Is_Overloadable (P_Name)
5761 and then not Is_Type (P_Name)
5763 -- Selected component of record. Type checking will validate
5764 -- name of selector.
5765 -- ??? could we rewrite an implicit dereference into an explicit
5768 Analyze_Selected_Component (N);
5770 -- Reference to type name in predicate/invariant expression
5772 elsif Is_Appropriate_For_Entry_Prefix (P_Type)
5773 and then not In_Open_Scopes (P_Name)
5774 and then (not Is_Concurrent_Type (Etype (P_Name))
5775 or else not In_Open_Scopes (Etype (P_Name)))
5777 -- Call to protected operation or entry. Type checking is
5778 -- needed on the prefix.
5780 Analyze_Selected_Component (N);
5782 elsif (In_Open_Scopes (P_Name)
5783 and then Ekind (P_Name) /= E_Void
5784 and then not Is_Overloadable (P_Name))
5785 or else (Is_Concurrent_Type (Etype (P_Name))
5786 and then In_Open_Scopes (Etype (P_Name)))
5788 -- Prefix denotes an enclosing loop, block, or task, i.e. an
5789 -- enclosing construct that is not a subprogram or accept.
5791 Find_Expanded_Name (N);
5793 elsif Ekind (P_Name) = E_Package then
5794 Find_Expanded_Name (N);
5796 elsif Is_Overloadable (P_Name) then
5798 -- The subprogram may be a renaming (of an enclosing scope) as
5799 -- in the case of the name of the generic within an instantiation.
5801 if Ekind_In (P_Name, E_Procedure, E_Function)
5802 and then Present (Alias (P_Name))
5803 and then Is_Generic_Instance (Alias (P_Name))
5805 P_Name := Alias (P_Name);
5808 if Is_Overloaded (P) then
5810 -- The prefix must resolve to a unique enclosing construct
5813 Found : Boolean := False;
5818 Get_First_Interp (P, Ind, It);
5819 while Present (It.Nam) loop
5820 if In_Open_Scopes (It.Nam) then
5823 "prefix must be unique enclosing scope", N);
5824 Set_Entity (N, Any_Id);
5825 Set_Etype (N, Any_Type);
5834 Get_Next_Interp (Ind, It);
5839 if In_Open_Scopes (P_Name) then
5840 Set_Entity (P, P_Name);
5841 Set_Is_Overloaded (P, False);
5842 Find_Expanded_Name (N);
5845 -- If no interpretation as an expanded name is possible, it
5846 -- must be a selected component of a record returned by a
5847 -- function call. Reformat prefix as a function call, the rest
5848 -- is done by type resolution. If the prefix is procedure or
5849 -- entry, as is P.X; this is an error.
5851 if Ekind (P_Name) /= E_Function
5852 and then (not Is_Overloaded (P)
5854 Nkind (Parent (N)) = N_Procedure_Call_Statement)
5856 -- Prefix may mention a package that is hidden by a local
5857 -- declaration: let the user know. Scan the full homonym
5858 -- chain, the candidate package may be anywhere on it.
5860 if Present (Homonym (Current_Entity (P_Name))) then
5862 P_Name := Current_Entity (P_Name);
5864 while Present (P_Name) loop
5865 exit when Ekind (P_Name) = E_Package;
5866 P_Name := Homonym (P_Name);
5869 if Present (P_Name) then
5870 Error_Msg_Sloc := Sloc (Entity (Prefix (N)));
5873 ("package& is hidden by declaration#",
5876 Set_Entity (Prefix (N), P_Name);
5877 Find_Expanded_Name (N);
5880 P_Name := Entity (Prefix (N));
5885 ("invalid prefix in selected component&", N, P_Name);
5886 Change_Selected_Component_To_Expanded_Name (N);
5887 Set_Entity (N, Any_Id);
5888 Set_Etype (N, Any_Type);
5891 Nam := New_Copy (P);
5892 Save_Interps (P, Nam);
5894 Make_Function_Call (Sloc (P), Name => Nam));
5896 Analyze_Selected_Component (N);
5900 -- Remaining cases generate various error messages
5903 -- Format node as expanded name, to avoid cascaded errors
5905 Change_Selected_Component_To_Expanded_Name (N);
5906 Set_Entity (N, Any_Id);
5907 Set_Etype (N, Any_Type);
5909 -- Issue error message, but avoid this if error issued already.
5910 -- Use identifier of prefix if one is available.
5912 if P_Name = Any_Id then
5915 elsif Ekind (P_Name) = E_Void then
5916 Premature_Usage (P);
5918 elsif Nkind (P) /= N_Attribute_Reference then
5920 "invalid prefix in selected component&", P);
5922 if Is_Access_Type (P_Type)
5923 and then Ekind (Designated_Type (P_Type)) = E_Incomplete_Type
5926 ("\dereference must not be of an incomplete type " &
5932 "invalid prefix in selected component", P);
5936 -- Selector name is restricted in SPARK
5938 if Nkind (N) = N_Expanded_Name
5939 and then Restriction_Check_Required (SPARK)
5941 if Is_Subprogram (P_Name) then
5942 Check_SPARK_Restriction
5943 ("prefix of expanded name cannot be a subprogram", P);
5944 elsif Ekind (P_Name) = E_Loop then
5945 Check_SPARK_Restriction
5946 ("prefix of expanded name cannot be a loop statement", P);
5951 -- If prefix is not the name of an entity, it must be an expression,
5952 -- whose type is appropriate for a record. This is determined by
5955 Analyze_Selected_Component (N);
5957 end Find_Selected_Component;
5963 procedure Find_Type (N : Node_Id) is
5973 elsif Nkind (N) = N_Attribute_Reference then
5975 -- Class attribute. This is not valid in Ada 83 mode, but we do not
5976 -- need to enforce that at this point, since the declaration of the
5977 -- tagged type in the prefix would have been flagged already.
5979 if Attribute_Name (N) = Name_Class then
5980 Check_Restriction (No_Dispatch, N);
5981 Find_Type (Prefix (N));
5983 -- Propagate error from bad prefix
5985 if Etype (Prefix (N)) = Any_Type then
5986 Set_Entity (N, Any_Type);
5987 Set_Etype (N, Any_Type);
5991 T := Base_Type (Entity (Prefix (N)));
5993 -- Case where type is not known to be tagged. Its appearance in
5994 -- the prefix of the 'Class attribute indicates that the full view
5997 if not Is_Tagged_Type (T) then
5998 if Ekind (T) = E_Incomplete_Type then
6000 -- It is legal to denote the class type of an incomplete
6001 -- type. The full type will have to be tagged, of course.
6002 -- In Ada 2005 this usage is declared obsolescent, so we
6003 -- warn accordingly. This usage is only legal if the type
6004 -- is completed in the current scope, and not for a limited
6007 if not Is_Tagged_Type (T)
6008 and then Ada_Version >= Ada_2005
6010 if From_With_Type (T) then
6012 ("prefix of Class attribute must be tagged", N);
6013 Set_Etype (N, Any_Type);
6014 Set_Entity (N, Any_Type);
6017 -- ??? This test is temporarily disabled (always False)
6018 -- because it causes an unwanted warning on GNAT sources
6019 -- (built with -gnatg, which includes Warn_On_Obsolescent_
6020 -- Feature). Once this issue is cleared in the sources, it
6023 elsif Warn_On_Obsolescent_Feature
6027 ("applying 'Class to an untagged incomplete type"
6028 & " is an obsolescent feature (RM J.11)", N);
6032 Set_Is_Tagged_Type (T);
6033 Set_Direct_Primitive_Operations (T, New_Elmt_List);
6034 Make_Class_Wide_Type (T);
6035 Set_Entity (N, Class_Wide_Type (T));
6036 Set_Etype (N, Class_Wide_Type (T));
6038 elsif Ekind (T) = E_Private_Type
6039 and then not Is_Generic_Type (T)
6040 and then In_Private_Part (Scope (T))
6042 -- The Class attribute can be applied to an untagged private
6043 -- type fulfilled by a tagged type prior to the full type
6044 -- declaration (but only within the parent package's private
6045 -- part). Create the class-wide type now and check that the
6046 -- full type is tagged later during its analysis. Note that
6047 -- we do not mark the private type as tagged, unlike the
6048 -- case of incomplete types, because the type must still
6049 -- appear untagged to outside units.
6051 if No (Class_Wide_Type (T)) then
6052 Make_Class_Wide_Type (T);
6055 Set_Entity (N, Class_Wide_Type (T));
6056 Set_Etype (N, Class_Wide_Type (T));
6059 -- Should we introduce a type Any_Tagged and use Wrong_Type
6060 -- here, it would be a bit more consistent???
6063 ("tagged type required, found}",
6064 Prefix (N), First_Subtype (T));
6065 Set_Entity (N, Any_Type);
6069 -- Case of tagged type
6072 if Is_Concurrent_Type (T) then
6073 if No (Corresponding_Record_Type (Entity (Prefix (N)))) then
6075 -- Previous error. Use current type, which at least
6076 -- provides some operations.
6078 C := Entity (Prefix (N));
6081 C := Class_Wide_Type
6082 (Corresponding_Record_Type (Entity (Prefix (N))));
6086 C := Class_Wide_Type (Entity (Prefix (N)));
6089 Set_Entity_With_Style_Check (N, C);
6090 Generate_Reference (C, N);
6094 -- Base attribute, not allowed in Ada 83
6096 elsif Attribute_Name (N) = Name_Base then
6097 Error_Msg_Name_1 := Name_Base;
6098 Check_SPARK_Restriction
6099 ("attribute% is only allowed as prefix of another attribute", N);
6101 if Ada_Version = Ada_83 and then Comes_From_Source (N) then
6103 ("(Ada 83) Base attribute not allowed in subtype mark", N);
6106 Find_Type (Prefix (N));
6107 Typ := Entity (Prefix (N));
6109 if Ada_Version >= Ada_95
6110 and then not Is_Scalar_Type (Typ)
6111 and then not Is_Generic_Type (Typ)
6114 ("prefix of Base attribute must be scalar type",
6117 elsif Warn_On_Redundant_Constructs
6118 and then Base_Type (Typ) = Typ
6120 Error_Msg_NE -- CODEFIX
6121 ("?redundant attribute, & is its own base type", N, Typ);
6124 T := Base_Type (Typ);
6126 -- Rewrite attribute reference with type itself (see similar
6127 -- processing in Analyze_Attribute, case Base). Preserve prefix
6128 -- if present, for other legality checks.
6130 if Nkind (Prefix (N)) = N_Expanded_Name then
6132 Make_Expanded_Name (Sloc (N),
6134 Prefix => New_Copy (Prefix (Prefix (N))),
6135 Selector_Name => New_Reference_To (T, Sloc (N))));
6138 Rewrite (N, New_Reference_To (T, Sloc (N)));
6145 elsif Attribute_Name (N) = Name_Stub_Type then
6147 -- This is handled in Analyze_Attribute
6151 -- All other attributes are invalid in a subtype mark
6154 Error_Msg_N ("invalid attribute in subtype mark", N);
6160 if Is_Entity_Name (N) then
6161 T_Name := Entity (N);
6163 Error_Msg_N ("subtype mark required in this context", N);
6164 Set_Etype (N, Any_Type);
6168 if T_Name = Any_Id or else Etype (N) = Any_Type then
6170 -- Undefined id. Make it into a valid type
6172 Set_Entity (N, Any_Type);
6174 elsif not Is_Type (T_Name)
6175 and then T_Name /= Standard_Void_Type
6177 Error_Msg_Sloc := Sloc (T_Name);
6178 Error_Msg_N ("subtype mark required in this context", N);
6179 Error_Msg_NE ("\\found & declared#", N, T_Name);
6180 Set_Entity (N, Any_Type);
6183 -- If the type is an incomplete type created to handle
6184 -- anonymous access components of a record type, then the
6185 -- incomplete type is the visible entity and subsequent
6186 -- references will point to it. Mark the original full
6187 -- type as referenced, to prevent spurious warnings.
6189 if Is_Incomplete_Type (T_Name)
6190 and then Present (Full_View (T_Name))
6191 and then not Comes_From_Source (T_Name)
6193 Set_Referenced (Full_View (T_Name));
6196 T_Name := Get_Full_View (T_Name);
6198 -- Ada 2005 (AI-251, AI-50217): Handle interfaces visible through
6199 -- limited-with clauses
6201 if From_With_Type (T_Name)
6202 and then Ekind (T_Name) in Incomplete_Kind
6203 and then Present (Non_Limited_View (T_Name))
6204 and then Is_Interface (Non_Limited_View (T_Name))
6206 T_Name := Non_Limited_View (T_Name);
6209 if In_Open_Scopes (T_Name) then
6210 if Ekind (Base_Type (T_Name)) = E_Task_Type then
6212 -- In Ada 2005, a task name can be used in an access
6213 -- definition within its own body. It cannot be used
6214 -- in the discriminant part of the task declaration,
6215 -- nor anywhere else in the declaration because entries
6216 -- cannot have access parameters.
6218 if Ada_Version >= Ada_2005
6219 and then Nkind (Parent (N)) = N_Access_Definition
6221 Set_Entity (N, T_Name);
6222 Set_Etype (N, T_Name);
6224 if Has_Completion (T_Name) then
6229 ("task type cannot be used as type mark " &
6230 "within its own declaration", N);
6235 ("task type cannot be used as type mark " &
6236 "within its own spec or body", N);
6239 elsif Ekind (Base_Type (T_Name)) = E_Protected_Type then
6241 -- In Ada 2005, a protected name can be used in an access
6242 -- definition within its own body.
6244 if Ada_Version >= Ada_2005
6245 and then Nkind (Parent (N)) = N_Access_Definition
6247 Set_Entity (N, T_Name);
6248 Set_Etype (N, T_Name);
6253 ("protected type cannot be used as type mark " &
6254 "within its own spec or body", N);
6258 Error_Msg_N ("type declaration cannot refer to itself", N);
6261 Set_Etype (N, Any_Type);
6262 Set_Entity (N, Any_Type);
6263 Set_Error_Posted (T_Name);
6267 Set_Entity (N, T_Name);
6268 Set_Etype (N, T_Name);
6272 if Present (Etype (N)) and then Comes_From_Source (N) then
6273 if Is_Fixed_Point_Type (Etype (N)) then
6274 Check_Restriction (No_Fixed_Point, N);
6275 elsif Is_Floating_Point_Type (Etype (N)) then
6276 Check_Restriction (No_Floating_Point, N);
6281 ------------------------------------
6282 -- Has_Implicit_Character_Literal --
6283 ------------------------------------
6285 function Has_Implicit_Character_Literal (N : Node_Id) return Boolean is
6287 Found : Boolean := False;
6288 P : constant Entity_Id := Entity (Prefix (N));
6289 Priv_Id : Entity_Id := Empty;
6292 if Ekind (P) = E_Package
6293 and then not In_Open_Scopes (P)
6295 Priv_Id := First_Private_Entity (P);
6298 if P = Standard_Standard then
6299 Change_Selected_Component_To_Expanded_Name (N);
6300 Rewrite (N, Selector_Name (N));
6302 Set_Etype (Original_Node (N), Standard_Character);
6306 Id := First_Entity (P);
6308 and then Id /= Priv_Id
6310 if Is_Standard_Character_Type (Id) and then Is_Base_Type (Id) then
6312 -- We replace the node with the literal itself, resolve as a
6313 -- character, and set the type correctly.
6316 Change_Selected_Component_To_Expanded_Name (N);
6317 Rewrite (N, Selector_Name (N));
6320 Set_Etype (Original_Node (N), Id);
6324 -- More than one type derived from Character in given scope.
6325 -- Collect all possible interpretations.
6327 Add_One_Interp (N, Id, Id);
6335 end Has_Implicit_Character_Literal;
6337 ----------------------
6338 -- Has_Private_With --
6339 ----------------------
6341 function Has_Private_With (E : Entity_Id) return Boolean is
6342 Comp_Unit : constant Node_Id := Cunit (Current_Sem_Unit);
6346 Item := First (Context_Items (Comp_Unit));
6347 while Present (Item) loop
6348 if Nkind (Item) = N_With_Clause
6349 and then Private_Present (Item)
6350 and then Entity (Name (Item)) = E
6359 end Has_Private_With;
6361 ---------------------------
6362 -- Has_Implicit_Operator --
6363 ---------------------------
6365 function Has_Implicit_Operator (N : Node_Id) return Boolean is
6366 Op_Id : constant Name_Id := Chars (Selector_Name (N));
6367 P : constant Entity_Id := Entity (Prefix (N));
6369 Priv_Id : Entity_Id := Empty;
6371 procedure Add_Implicit_Operator
6373 Op_Type : Entity_Id := Empty);
6374 -- Add implicit interpretation to node N, using the type for which a
6375 -- predefined operator exists. If the operator yields a boolean type,
6376 -- the Operand_Type is implicitly referenced by the operator, and a
6377 -- reference to it must be generated.
6379 ---------------------------
6380 -- Add_Implicit_Operator --
6381 ---------------------------
6383 procedure Add_Implicit_Operator
6385 Op_Type : Entity_Id := Empty)
6387 Predef_Op : Entity_Id;
6390 Predef_Op := Current_Entity (Selector_Name (N));
6392 while Present (Predef_Op)
6393 and then Scope (Predef_Op) /= Standard_Standard
6395 Predef_Op := Homonym (Predef_Op);
6398 if Nkind (N) = N_Selected_Component then
6399 Change_Selected_Component_To_Expanded_Name (N);
6402 -- If the context is an unanalyzed function call, determine whether
6403 -- a binary or unary interpretation is required.
6405 if Nkind (Parent (N)) = N_Indexed_Component then
6407 Is_Binary_Call : constant Boolean :=
6409 (Next (First (Expressions (Parent (N)))));
6410 Is_Binary_Op : constant Boolean :=
6412 (Predef_Op) /= Last_Entity (Predef_Op);
6413 Predef_Op2 : constant Entity_Id := Homonym (Predef_Op);
6416 if Is_Binary_Call then
6417 if Is_Binary_Op then
6418 Add_One_Interp (N, Predef_Op, T);
6420 Add_One_Interp (N, Predef_Op2, T);
6424 if not Is_Binary_Op then
6425 Add_One_Interp (N, Predef_Op, T);
6427 Add_One_Interp (N, Predef_Op2, T);
6433 Add_One_Interp (N, Predef_Op, T);
6435 -- For operators with unary and binary interpretations, if
6436 -- context is not a call, add both
6438 if Present (Homonym (Predef_Op)) then
6439 Add_One_Interp (N, Homonym (Predef_Op), T);
6443 -- The node is a reference to a predefined operator, and
6444 -- an implicit reference to the type of its operands.
6446 if Present (Op_Type) then
6447 Generate_Operator_Reference (N, Op_Type);
6449 Generate_Operator_Reference (N, T);
6451 end Add_Implicit_Operator;
6453 -- Start of processing for Has_Implicit_Operator
6456 if Ekind (P) = E_Package
6457 and then not In_Open_Scopes (P)
6459 Priv_Id := First_Private_Entity (P);
6462 Id := First_Entity (P);
6466 -- Boolean operators: an implicit declaration exists if the scope
6467 -- contains a declaration for a derived Boolean type, or for an
6468 -- array of Boolean type.
6470 when Name_Op_And | Name_Op_Not | Name_Op_Or | Name_Op_Xor =>
6471 while Id /= Priv_Id loop
6472 if Valid_Boolean_Arg (Id) and then Is_Base_Type (Id) then
6473 Add_Implicit_Operator (Id);
6480 -- Equality: look for any non-limited type (result is Boolean)
6482 when Name_Op_Eq | Name_Op_Ne =>
6483 while Id /= Priv_Id loop
6485 and then not Is_Limited_Type (Id)
6486 and then Is_Base_Type (Id)
6488 Add_Implicit_Operator (Standard_Boolean, Id);
6495 -- Comparison operators: scalar type, or array of scalar
6497 when Name_Op_Lt | Name_Op_Le | Name_Op_Gt | Name_Op_Ge =>
6498 while Id /= Priv_Id loop
6499 if (Is_Scalar_Type (Id)
6500 or else (Is_Array_Type (Id)
6501 and then Is_Scalar_Type (Component_Type (Id))))
6502 and then Is_Base_Type (Id)
6504 Add_Implicit_Operator (Standard_Boolean, Id);
6511 -- Arithmetic operators: any numeric type
6521 while Id /= Priv_Id loop
6522 if Is_Numeric_Type (Id) and then Is_Base_Type (Id) then
6523 Add_Implicit_Operator (Id);
6530 -- Concatenation: any one-dimensional array type
6532 when Name_Op_Concat =>
6533 while Id /= Priv_Id loop
6534 if Is_Array_Type (Id)
6535 and then Number_Dimensions (Id) = 1
6536 and then Is_Base_Type (Id)
6538 Add_Implicit_Operator (Id);
6545 -- What is the others condition here? Should we be using a
6546 -- subtype of Name_Id that would restrict to operators ???
6548 when others => null;
6551 -- If we fall through, then we do not have an implicit operator
6555 end Has_Implicit_Operator;
6557 -----------------------------------
6558 -- Has_Loop_In_Inner_Open_Scopes --
6559 -----------------------------------
6561 function Has_Loop_In_Inner_Open_Scopes (S : Entity_Id) return Boolean is
6563 -- Several scope stacks are maintained by Scope_Stack. The base of the
6564 -- currently active scope stack is denoted by the Is_Active_Stack_Base
6565 -- flag in the scope stack entry. Note that the scope stacks used to
6566 -- simply be delimited implicitly by the presence of Standard_Standard
6567 -- at their base, but there now are cases where this is not sufficient
6568 -- because Standard_Standard actually may appear in the middle of the
6569 -- active set of scopes.
6571 for J in reverse 0 .. Scope_Stack.Last loop
6573 -- S was reached without seing a loop scope first
6575 if Scope_Stack.Table (J).Entity = S then
6578 -- S was not yet reached, so it contains at least one inner loop
6580 elsif Ekind (Scope_Stack.Table (J).Entity) = E_Loop then
6584 -- Check Is_Active_Stack_Base to tell us when to stop, as there are
6585 -- cases where Standard_Standard appears in the middle of the active
6586 -- set of scopes. This affects the declaration and overriding of
6587 -- private inherited operations in instantiations of generic child
6590 pragma Assert (not Scope_Stack.Table (J).Is_Active_Stack_Base);
6593 raise Program_Error; -- unreachable
6594 end Has_Loop_In_Inner_Open_Scopes;
6596 --------------------
6597 -- In_Open_Scopes --
6598 --------------------
6600 function In_Open_Scopes (S : Entity_Id) return Boolean is
6602 -- Several scope stacks are maintained by Scope_Stack. The base of the
6603 -- currently active scope stack is denoted by the Is_Active_Stack_Base
6604 -- flag in the scope stack entry. Note that the scope stacks used to
6605 -- simply be delimited implicitly by the presence of Standard_Standard
6606 -- at their base, but there now are cases where this is not sufficient
6607 -- because Standard_Standard actually may appear in the middle of the
6608 -- active set of scopes.
6610 for J in reverse 0 .. Scope_Stack.Last loop
6611 if Scope_Stack.Table (J).Entity = S then
6615 -- Check Is_Active_Stack_Base to tell us when to stop, as there are
6616 -- cases where Standard_Standard appears in the middle of the active
6617 -- set of scopes. This affects the declaration and overriding of
6618 -- private inherited operations in instantiations of generic child
6621 exit when Scope_Stack.Table (J).Is_Active_Stack_Base;
6627 -----------------------------
6628 -- Inherit_Renamed_Profile --
6629 -----------------------------
6631 procedure Inherit_Renamed_Profile (New_S : Entity_Id; Old_S : Entity_Id) is
6638 if Ekind (Old_S) = E_Operator then
6639 New_F := First_Formal (New_S);
6641 while Present (New_F) loop
6642 Set_Etype (New_F, Base_Type (Etype (New_F)));
6643 Next_Formal (New_F);
6646 Set_Etype (New_S, Base_Type (Etype (New_S)));
6649 New_F := First_Formal (New_S);
6650 Old_F := First_Formal (Old_S);
6652 while Present (New_F) loop
6653 New_T := Etype (New_F);
6654 Old_T := Etype (Old_F);
6656 -- If the new type is a renaming of the old one, as is the
6657 -- case for actuals in instances, retain its name, to simplify
6658 -- later disambiguation.
6660 if Nkind (Parent (New_T)) = N_Subtype_Declaration
6661 and then Is_Entity_Name (Subtype_Indication (Parent (New_T)))
6662 and then Entity (Subtype_Indication (Parent (New_T))) = Old_T
6666 Set_Etype (New_F, Old_T);
6669 Next_Formal (New_F);
6670 Next_Formal (Old_F);
6673 if Ekind_In (Old_S, E_Function, E_Enumeration_Literal) then
6674 Set_Etype (New_S, Etype (Old_S));
6677 end Inherit_Renamed_Profile;
6683 procedure Initialize is
6688 -------------------------
6689 -- Install_Use_Clauses --
6690 -------------------------
6692 procedure Install_Use_Clauses
6694 Force_Installation : Boolean := False)
6702 while Present (U) loop
6704 -- Case of USE package
6706 if Nkind (U) = N_Use_Package_Clause then
6707 P := First (Names (U));
6708 while Present (P) loop
6711 if Ekind (Id) = E_Package then
6713 Note_Redundant_Use (P);
6715 elsif Present (Renamed_Object (Id))
6716 and then In_Use (Renamed_Object (Id))
6718 Note_Redundant_Use (P);
6720 elsif Force_Installation or else Applicable_Use (P) then
6721 Use_One_Package (Id, U);
6732 P := First (Subtype_Marks (U));
6733 while Present (P) loop
6734 if not Is_Entity_Name (P)
6735 or else No (Entity (P))
6739 elsif Entity (P) /= Any_Type then
6747 Next_Use_Clause (U);
6749 end Install_Use_Clauses;
6751 -------------------------------------
6752 -- Is_Appropriate_For_Entry_Prefix --
6753 -------------------------------------
6755 function Is_Appropriate_For_Entry_Prefix (T : Entity_Id) return Boolean is
6756 P_Type : Entity_Id := T;
6759 if Is_Access_Type (P_Type) then
6760 P_Type := Designated_Type (P_Type);
6763 return Is_Task_Type (P_Type) or else Is_Protected_Type (P_Type);
6764 end Is_Appropriate_For_Entry_Prefix;
6766 -------------------------------
6767 -- Is_Appropriate_For_Record --
6768 -------------------------------
6770 function Is_Appropriate_For_Record (T : Entity_Id) return Boolean is
6772 function Has_Components (T1 : Entity_Id) return Boolean;
6773 -- Determine if given type has components (i.e. is either a record
6774 -- type or a type that has discriminants).
6776 --------------------
6777 -- Has_Components --
6778 --------------------
6780 function Has_Components (T1 : Entity_Id) return Boolean is
6782 return Is_Record_Type (T1)
6783 or else (Is_Private_Type (T1) and then Has_Discriminants (T1))
6784 or else (Is_Task_Type (T1) and then Has_Discriminants (T1))
6785 or else (Is_Incomplete_Type (T1)
6786 and then From_With_Type (T1)
6787 and then Present (Non_Limited_View (T1))
6788 and then Is_Record_Type
6789 (Get_Full_View (Non_Limited_View (T1))));
6792 -- Start of processing for Is_Appropriate_For_Record
6797 and then (Has_Components (T)
6798 or else (Is_Access_Type (T)
6799 and then Has_Components (Designated_Type (T))));
6800 end Is_Appropriate_For_Record;
6802 ------------------------
6803 -- Note_Redundant_Use --
6804 ------------------------
6806 procedure Note_Redundant_Use (Clause : Node_Id) is
6807 Pack_Name : constant Entity_Id := Entity (Clause);
6808 Cur_Use : constant Node_Id := Current_Use_Clause (Pack_Name);
6809 Decl : constant Node_Id := Parent (Clause);
6811 Prev_Use : Node_Id := Empty;
6812 Redundant : Node_Id := Empty;
6813 -- The Use_Clause which is actually redundant. In the simplest case it
6814 -- is Pack itself, but when we compile a body we install its context
6815 -- before that of its spec, in which case it is the use_clause in the
6816 -- spec that will appear to be redundant, and we want the warning to be
6817 -- placed on the body. Similar complications appear when the redundancy
6818 -- is between a child unit and one of its ancestors.
6821 Set_Redundant_Use (Clause, True);
6823 if not Comes_From_Source (Clause)
6825 or else not Warn_On_Redundant_Constructs
6830 if not Is_Compilation_Unit (Current_Scope) then
6832 -- If the use_clause is in an inner scope, it is made redundant by
6833 -- some clause in the current context, with one exception: If we're
6834 -- compiling a nested package body, and the use_clause comes from the
6835 -- corresponding spec, the clause is not necessarily fully redundant,
6836 -- so we should not warn. If a warning was warranted, it would have
6837 -- been given when the spec was processed.
6839 if Nkind (Parent (Decl)) = N_Package_Specification then
6841 Package_Spec_Entity : constant Entity_Id :=
6842 Defining_Unit_Name (Parent (Decl));
6844 if In_Package_Body (Package_Spec_Entity) then
6850 Redundant := Clause;
6851 Prev_Use := Cur_Use;
6853 elsif Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Body then
6855 Cur_Unit : constant Unit_Number_Type := Get_Source_Unit (Cur_Use);
6856 New_Unit : constant Unit_Number_Type := Get_Source_Unit (Clause);
6860 if Cur_Unit = New_Unit then
6862 -- Redundant clause in same body
6864 Redundant := Clause;
6865 Prev_Use := Cur_Use;
6867 elsif Cur_Unit = Current_Sem_Unit then
6869 -- If the new clause is not in the current unit it has been
6870 -- analyzed first, and it makes the other one redundant.
6871 -- However, if the new clause appears in a subunit, Cur_Unit
6872 -- is still the parent, and in that case the redundant one
6873 -- is the one appearing in the subunit.
6875 if Nkind (Unit (Cunit (New_Unit))) = N_Subunit then
6876 Redundant := Clause;
6877 Prev_Use := Cur_Use;
6879 -- Most common case: redundant clause in body,
6880 -- original clause in spec. Current scope is spec entity.
6885 Unit (Library_Unit (Cunit (Current_Sem_Unit))))
6887 Redundant := Cur_Use;
6891 -- The new clause may appear in an unrelated unit, when
6892 -- the parents of a generic are being installed prior to
6893 -- instantiation. In this case there must be no warning.
6894 -- We detect this case by checking whether the current top
6895 -- of the stack is related to the current compilation.
6897 Scop := Current_Scope;
6898 while Present (Scop)
6899 and then Scop /= Standard_Standard
6901 if Is_Compilation_Unit (Scop)
6902 and then not Is_Child_Unit (Scop)
6906 elsif Scop = Cunit_Entity (Current_Sem_Unit) then
6910 Scop := Scope (Scop);
6913 Redundant := Cur_Use;
6917 elsif New_Unit = Current_Sem_Unit then
6918 Redundant := Clause;
6919 Prev_Use := Cur_Use;
6922 -- Neither is the current unit, so they appear in parent or
6923 -- sibling units. Warning will be emitted elsewhere.
6929 elsif Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Declaration
6930 and then Present (Parent_Spec (Unit (Cunit (Current_Sem_Unit))))
6932 -- Use_clause is in child unit of current unit, and the child unit
6933 -- appears in the context of the body of the parent, so it has been
6934 -- installed first, even though it is the redundant one. Depending on
6935 -- their placement in the context, the visible or the private parts
6936 -- of the two units, either might appear as redundant, but the
6937 -- message has to be on the current unit.
6939 if Get_Source_Unit (Cur_Use) = Current_Sem_Unit then
6940 Redundant := Cur_Use;
6943 Redundant := Clause;
6944 Prev_Use := Cur_Use;
6947 -- If the new use clause appears in the private part of a parent unit
6948 -- it may appear to be redundant w.r.t. a use clause in a child unit,
6949 -- but the previous use clause was needed in the visible part of the
6950 -- child, and no warning should be emitted.
6952 if Nkind (Parent (Decl)) = N_Package_Specification
6954 List_Containing (Decl) = Private_Declarations (Parent (Decl))
6957 Par : constant Entity_Id := Defining_Entity (Parent (Decl));
6958 Spec : constant Node_Id :=
6959 Specification (Unit (Cunit (Current_Sem_Unit)));
6962 if Is_Compilation_Unit (Par)
6963 and then Par /= Cunit_Entity (Current_Sem_Unit)
6964 and then Parent (Cur_Use) = Spec
6966 List_Containing (Cur_Use) = Visible_Declarations (Spec)
6973 -- Finally, if the current use clause is in the context then
6974 -- the clause is redundant when it is nested within the unit.
6976 elsif Nkind (Parent (Cur_Use)) = N_Compilation_Unit
6977 and then Nkind (Parent (Parent (Clause))) /= N_Compilation_Unit
6978 and then Get_Source_Unit (Cur_Use) = Get_Source_Unit (Clause)
6980 Redundant := Clause;
6981 Prev_Use := Cur_Use;
6987 if Present (Redundant) then
6988 Error_Msg_Sloc := Sloc (Prev_Use);
6989 Error_Msg_NE -- CODEFIX
6990 ("& is already use-visible through previous use clause #?",
6991 Redundant, Pack_Name);
6993 end Note_Redundant_Use;
6999 procedure Pop_Scope is
7000 SST : Scope_Stack_Entry renames Scope_Stack.Table (Scope_Stack.Last);
7001 S : constant Entity_Id := SST.Entity;
7004 if Debug_Flag_E then
7008 -- Set Default_Storage_Pool field of the library unit if necessary
7010 if Ekind_In (S, E_Package, E_Generic_Package)
7012 Nkind (Parent (Unit_Declaration_Node (S))) = N_Compilation_Unit
7015 Aux : constant Node_Id :=
7016 Aux_Decls_Node (Parent (Unit_Declaration_Node (S)));
7018 if No (Default_Storage_Pool (Aux)) then
7019 Set_Default_Storage_Pool (Aux, Default_Pool);
7024 Scope_Suppress := SST.Save_Scope_Suppress;
7025 Local_Suppress_Stack_Top := SST.Save_Local_Suppress_Stack_Top;
7026 Check_Policy_List := SST.Save_Check_Policy_List;
7027 Default_Pool := SST.Save_Default_Storage_Pool;
7029 if Debug_Flag_W then
7030 Write_Str ("<-- exiting scope: ");
7031 Write_Name (Chars (Current_Scope));
7032 Write_Str (", Depth=");
7033 Write_Int (Int (Scope_Stack.Last));
7037 End_Use_Clauses (SST.First_Use_Clause);
7039 -- If the actions to be wrapped are still there they will get lost
7040 -- causing incomplete code to be generated. It is better to abort in
7041 -- this case (and we do the abort even with assertions off since the
7042 -- penalty is incorrect code generation)
7044 if SST.Actions_To_Be_Wrapped_Before /= No_List
7046 SST.Actions_To_Be_Wrapped_After /= No_List
7048 raise Program_Error;
7051 -- Free last subprogram name if allocated, and pop scope
7053 Free (SST.Last_Subprogram_Name);
7054 Scope_Stack.Decrement_Last;
7061 procedure Push_Scope (S : Entity_Id) is
7062 E : constant Entity_Id := Scope (S);
7065 if Ekind (S) = E_Void then
7068 -- Set scope depth if not a non-concurrent type, and we have not yet set
7069 -- the scope depth. This means that we have the first occurrence of the
7070 -- scope, and this is where the depth is set.
7072 elsif (not Is_Type (S) or else Is_Concurrent_Type (S))
7073 and then not Scope_Depth_Set (S)
7075 if S = Standard_Standard then
7076 Set_Scope_Depth_Value (S, Uint_0);
7078 elsif Is_Child_Unit (S) then
7079 Set_Scope_Depth_Value (S, Uint_1);
7081 elsif not Is_Record_Type (Current_Scope) then
7082 if Ekind (S) = E_Loop then
7083 Set_Scope_Depth_Value (S, Scope_Depth (Current_Scope));
7085 Set_Scope_Depth_Value (S, Scope_Depth (Current_Scope) + 1);
7090 Scope_Stack.Increment_Last;
7093 SST : Scope_Stack_Entry renames Scope_Stack.Table (Scope_Stack.Last);
7097 SST.Save_Scope_Suppress := Scope_Suppress;
7098 SST.Save_Local_Suppress_Stack_Top := Local_Suppress_Stack_Top;
7099 SST.Save_Check_Policy_List := Check_Policy_List;
7100 SST.Save_Default_Storage_Pool := Default_Pool;
7102 if Scope_Stack.Last > Scope_Stack.First then
7103 SST.Component_Alignment_Default := Scope_Stack.Table
7104 (Scope_Stack.Last - 1).
7105 Component_Alignment_Default;
7108 SST.Last_Subprogram_Name := null;
7109 SST.Is_Transient := False;
7110 SST.Node_To_Be_Wrapped := Empty;
7111 SST.Pending_Freeze_Actions := No_List;
7112 SST.Actions_To_Be_Wrapped_Before := No_List;
7113 SST.Actions_To_Be_Wrapped_After := No_List;
7114 SST.First_Use_Clause := Empty;
7115 SST.Is_Active_Stack_Base := False;
7116 SST.Previous_Visibility := False;
7119 if Debug_Flag_W then
7120 Write_Str ("--> new scope: ");
7121 Write_Name (Chars (Current_Scope));
7122 Write_Str (", Id=");
7123 Write_Int (Int (Current_Scope));
7124 Write_Str (", Depth=");
7125 Write_Int (Int (Scope_Stack.Last));
7129 -- Deal with copying flags from the previous scope to this one. This is
7130 -- not necessary if either scope is standard, or if the new scope is a
7133 if S /= Standard_Standard
7134 and then Scope (S) /= Standard_Standard
7135 and then not Is_Child_Unit (S)
7137 if Nkind (E) not in N_Entity then
7141 -- Copy categorization flags from Scope (S) to S, this is not done
7142 -- when Scope (S) is Standard_Standard since propagation is from
7143 -- library unit entity inwards. Copy other relevant attributes as
7144 -- well (Discard_Names in particular).
7146 -- We only propagate inwards for library level entities,
7147 -- inner level subprograms do not inherit the categorization.
7149 if Is_Library_Level_Entity (S) then
7150 Set_Is_Preelaborated (S, Is_Preelaborated (E));
7151 Set_Is_Shared_Passive (S, Is_Shared_Passive (E));
7152 Set_Discard_Names (S, Discard_Names (E));
7153 Set_Suppress_Value_Tracking_On_Call
7154 (S, Suppress_Value_Tracking_On_Call (E));
7155 Set_Categorization_From_Scope (E => S, Scop => E);
7159 if Is_Child_Unit (S)
7160 and then Present (E)
7161 and then Ekind_In (E, E_Package, E_Generic_Package)
7163 Nkind (Parent (Unit_Declaration_Node (E))) = N_Compilation_Unit
7166 Aux : constant Node_Id :=
7167 Aux_Decls_Node (Parent (Unit_Declaration_Node (E)));
7169 if Present (Default_Storage_Pool (Aux)) then
7170 Default_Pool := Default_Storage_Pool (Aux);
7176 ---------------------
7177 -- Premature_Usage --
7178 ---------------------
7180 procedure Premature_Usage (N : Node_Id) is
7181 Kind : constant Node_Kind := Nkind (Parent (Entity (N)));
7182 E : Entity_Id := Entity (N);
7185 -- Within an instance, the analysis of the actual for a formal object
7186 -- does not see the name of the object itself. This is significant only
7187 -- if the object is an aggregate, where its analysis does not do any
7188 -- name resolution on component associations. (see 4717-008). In such a
7189 -- case, look for the visible homonym on the chain.
7192 and then Present (Homonym (E))
7197 and then not In_Open_Scopes (Scope (E))
7204 Set_Etype (N, Etype (E));
7209 if Kind = N_Component_Declaration then
7211 ("component&! cannot be used before end of record declaration", N);
7213 elsif Kind = N_Parameter_Specification then
7215 ("formal parameter&! cannot be used before end of specification",
7218 elsif Kind = N_Discriminant_Specification then
7220 ("discriminant&! cannot be used before end of discriminant part",
7223 elsif Kind = N_Procedure_Specification
7224 or else Kind = N_Function_Specification
7227 ("subprogram&! cannot be used before end of its declaration",
7230 elsif Kind = N_Full_Type_Declaration then
7232 ("type& cannot be used before end of its declaration!", N);
7236 ("object& cannot be used before end of its declaration!", N);
7238 end Premature_Usage;
7240 ------------------------
7241 -- Present_System_Aux --
7242 ------------------------
7244 function Present_System_Aux (N : Node_Id := Empty) return Boolean is
7246 Aux_Name : Unit_Name_Type;
7247 Unum : Unit_Number_Type;
7252 function Find_System (C_Unit : Node_Id) return Entity_Id;
7253 -- Scan context clause of compilation unit to find with_clause
7260 function Find_System (C_Unit : Node_Id) return Entity_Id is
7261 With_Clause : Node_Id;
7264 With_Clause := First (Context_Items (C_Unit));
7265 while Present (With_Clause) loop
7266 if (Nkind (With_Clause) = N_With_Clause
7267 and then Chars (Name (With_Clause)) = Name_System)
7268 and then Comes_From_Source (With_Clause)
7279 -- Start of processing for Present_System_Aux
7282 -- The child unit may have been loaded and analyzed already
7284 if Present (System_Aux_Id) then
7287 -- If no previous pragma for System.Aux, nothing to load
7289 elsif No (System_Extend_Unit) then
7292 -- Use the unit name given in the pragma to retrieve the unit.
7293 -- Verify that System itself appears in the context clause of the
7294 -- current compilation. If System is not present, an error will
7295 -- have been reported already.
7298 With_Sys := Find_System (Cunit (Current_Sem_Unit));
7300 The_Unit := Unit (Cunit (Current_Sem_Unit));
7304 (Nkind (The_Unit) = N_Package_Body
7305 or else (Nkind (The_Unit) = N_Subprogram_Body
7307 not Acts_As_Spec (Cunit (Current_Sem_Unit))))
7309 With_Sys := Find_System (Library_Unit (Cunit (Current_Sem_Unit)));
7313 and then Present (N)
7315 -- If we are compiling a subunit, we need to examine its
7316 -- context as well (Current_Sem_Unit is the parent unit);
7318 The_Unit := Parent (N);
7319 while Nkind (The_Unit) /= N_Compilation_Unit loop
7320 The_Unit := Parent (The_Unit);
7323 if Nkind (Unit (The_Unit)) = N_Subunit then
7324 With_Sys := Find_System (The_Unit);
7328 if No (With_Sys) then
7332 Loc := Sloc (With_Sys);
7333 Get_Name_String (Chars (Expression (System_Extend_Unit)));
7334 Name_Buffer (8 .. Name_Len + 7) := Name_Buffer (1 .. Name_Len);
7335 Name_Buffer (1 .. 7) := "system.";
7336 Name_Buffer (Name_Len + 8) := '%';
7337 Name_Buffer (Name_Len + 9) := 's';
7338 Name_Len := Name_Len + 9;
7339 Aux_Name := Name_Find;
7343 (Load_Name => Aux_Name,
7346 Error_Node => With_Sys);
7348 if Unum /= No_Unit then
7349 Semantics (Cunit (Unum));
7351 Defining_Entity (Specification (Unit (Cunit (Unum))));
7354 Make_With_Clause (Loc,
7356 Make_Expanded_Name (Loc,
7357 Chars => Chars (System_Aux_Id),
7358 Prefix => New_Reference_To (Scope (System_Aux_Id), Loc),
7359 Selector_Name => New_Reference_To (System_Aux_Id, Loc)));
7361 Set_Entity (Name (Withn), System_Aux_Id);
7363 Set_Library_Unit (Withn, Cunit (Unum));
7364 Set_Corresponding_Spec (Withn, System_Aux_Id);
7365 Set_First_Name (Withn, True);
7366 Set_Implicit_With (Withn, True);
7368 Insert_After (With_Sys, Withn);
7369 Mark_Rewrite_Insertion (Withn);
7370 Set_Context_Installed (Withn);
7374 -- Here if unit load failed
7377 Error_Msg_Name_1 := Name_System;
7378 Error_Msg_Name_2 := Chars (Expression (System_Extend_Unit));
7380 ("extension package `%.%` does not exist",
7381 Opt.System_Extend_Unit);
7385 end Present_System_Aux;
7387 -------------------------
7388 -- Restore_Scope_Stack --
7389 -------------------------
7391 procedure Restore_Scope_Stack (Handle_Use : Boolean := True) is
7394 Comp_Unit : Node_Id;
7395 In_Child : Boolean := False;
7396 Full_Vis : Boolean := True;
7397 SS_Last : constant Int := Scope_Stack.Last;
7400 -- Restore visibility of previous scope stack, if any
7402 for J in reverse 0 .. Scope_Stack.Last loop
7403 exit when Scope_Stack.Table (J).Entity = Standard_Standard
7404 or else No (Scope_Stack.Table (J).Entity);
7406 S := Scope_Stack.Table (J).Entity;
7408 if not Is_Hidden_Open_Scope (S) then
7410 -- If the parent scope is hidden, its entities are hidden as
7411 -- well, unless the entity is the instantiation currently
7414 if not Is_Hidden_Open_Scope (Scope (S))
7415 or else not Analyzed (Parent (S))
7416 or else Scope (S) = Standard_Standard
7418 Set_Is_Immediately_Visible (S, True);
7421 E := First_Entity (S);
7422 while Present (E) loop
7423 if Is_Child_Unit (E) then
7424 if not From_With_Type (E) then
7425 Set_Is_Immediately_Visible (E,
7426 Is_Visible_Child_Unit (E) or else In_Open_Scopes (E));
7430 (Nkind (Parent (E)) = N_Defining_Program_Unit_Name
7432 Nkind (Parent (Parent (E))) = N_Package_Specification);
7433 Set_Is_Immediately_Visible (E,
7434 Limited_View_Installed (Parent (Parent (E))));
7437 Set_Is_Immediately_Visible (E, True);
7443 and then Is_Package_Or_Generic_Package (S)
7445 -- We are in the visible part of the package scope
7447 exit when E = First_Private_Entity (S);
7451 -- The visibility of child units (siblings of current compilation)
7452 -- must be restored in any case. Their declarations may appear
7453 -- after the private part of the parent.
7455 if not Full_Vis then
7456 while Present (E) loop
7457 if Is_Child_Unit (E) then
7458 Set_Is_Immediately_Visible (E,
7459 Is_Visible_Child_Unit (E) or else In_Open_Scopes (E));
7467 if Is_Child_Unit (S)
7468 and not In_Child -- check only for current unit
7472 -- Restore visibility of parents according to whether the child
7473 -- is private and whether we are in its visible part.
7475 Comp_Unit := Parent (Unit_Declaration_Node (S));
7477 if Nkind (Comp_Unit) = N_Compilation_Unit
7478 and then Private_Present (Comp_Unit)
7482 elsif Is_Package_Or_Generic_Package (S)
7483 and then (In_Private_Part (S) or else In_Package_Body (S))
7487 -- if S is the scope of some instance (which has already been
7488 -- seen on the stack) it does not affect the visibility of
7491 elsif Is_Hidden_Open_Scope (S) then
7494 elsif (Ekind (S) = E_Procedure
7495 or else Ekind (S) = E_Function)
7496 and then Has_Completion (S)
7507 if SS_Last >= Scope_Stack.First
7508 and then Scope_Stack.Table (SS_Last).Entity /= Standard_Standard
7511 Install_Use_Clauses (Scope_Stack.Table (SS_Last).First_Use_Clause);
7513 end Restore_Scope_Stack;
7515 ----------------------
7516 -- Save_Scope_Stack --
7517 ----------------------
7519 procedure Save_Scope_Stack (Handle_Use : Boolean := True) is
7522 SS_Last : constant Int := Scope_Stack.Last;
7525 if SS_Last >= Scope_Stack.First
7526 and then Scope_Stack.Table (SS_Last).Entity /= Standard_Standard
7529 End_Use_Clauses (Scope_Stack.Table (SS_Last).First_Use_Clause);
7532 -- If the call is from within a compilation unit, as when called from
7533 -- Rtsfind, make current entries in scope stack invisible while we
7534 -- analyze the new unit.
7536 for J in reverse 0 .. SS_Last loop
7537 exit when Scope_Stack.Table (J).Entity = Standard_Standard
7538 or else No (Scope_Stack.Table (J).Entity);
7540 S := Scope_Stack.Table (J).Entity;
7541 Set_Is_Immediately_Visible (S, False);
7543 E := First_Entity (S);
7544 while Present (E) loop
7545 Set_Is_Immediately_Visible (E, False);
7551 end Save_Scope_Stack;
7557 procedure Set_Use (L : List_Id) is
7559 Pack_Name : Node_Id;
7566 while Present (Decl) loop
7567 if Nkind (Decl) = N_Use_Package_Clause then
7568 Chain_Use_Clause (Decl);
7570 Pack_Name := First (Names (Decl));
7571 while Present (Pack_Name) loop
7572 Pack := Entity (Pack_Name);
7574 if Ekind (Pack) = E_Package
7575 and then Applicable_Use (Pack_Name)
7577 Use_One_Package (Pack, Decl);
7583 elsif Nkind (Decl) = N_Use_Type_Clause then
7584 Chain_Use_Clause (Decl);
7586 Id := First (Subtype_Marks (Decl));
7587 while Present (Id) loop
7588 if Entity (Id) /= Any_Type then
7601 ---------------------
7602 -- Use_One_Package --
7603 ---------------------
7605 procedure Use_One_Package (P : Entity_Id; N : Node_Id) is
7608 Current_Instance : Entity_Id := Empty;
7610 Private_With_OK : Boolean := False;
7613 if Ekind (P) /= E_Package then
7618 Set_Current_Use_Clause (P, N);
7620 -- Ada 2005 (AI-50217): Check restriction
7622 if From_With_Type (P) then
7623 Error_Msg_N ("limited withed package cannot appear in use clause", N);
7626 -- Find enclosing instance, if any
7629 Current_Instance := Current_Scope;
7630 while not Is_Generic_Instance (Current_Instance) loop
7631 Current_Instance := Scope (Current_Instance);
7634 if No (Hidden_By_Use_Clause (N)) then
7635 Set_Hidden_By_Use_Clause (N, New_Elmt_List);
7639 -- If unit is a package renaming, indicate that the renamed
7640 -- package is also in use (the flags on both entities must
7641 -- remain consistent, and a subsequent use of either of them
7642 -- should be recognized as redundant).
7644 if Present (Renamed_Object (P)) then
7645 Set_In_Use (Renamed_Object (P));
7646 Set_Current_Use_Clause (Renamed_Object (P), N);
7647 Real_P := Renamed_Object (P);
7652 -- Ada 2005 (AI-262): Check the use_clause of a private withed package
7653 -- found in the private part of a package specification
7655 if In_Private_Part (Current_Scope)
7656 and then Has_Private_With (P)
7657 and then Is_Child_Unit (Current_Scope)
7658 and then Is_Child_Unit (P)
7659 and then Is_Ancestor_Package (Scope (Current_Scope), P)
7661 Private_With_OK := True;
7664 -- Loop through entities in one package making them potentially
7667 Id := First_Entity (P);
7669 and then (Id /= First_Private_Entity (P)
7670 or else Private_With_OK) -- Ada 2005 (AI-262)
7672 Prev := Current_Entity (Id);
7673 while Present (Prev) loop
7674 if Is_Immediately_Visible (Prev)
7675 and then (not Is_Overloadable (Prev)
7676 or else not Is_Overloadable (Id)
7677 or else (Type_Conformant (Id, Prev)))
7679 if No (Current_Instance) then
7681 -- Potentially use-visible entity remains hidden
7683 goto Next_Usable_Entity;
7685 -- A use clause within an instance hides outer global entities,
7686 -- which are not used to resolve local entities in the
7687 -- instance. Note that the predefined entities in Standard
7688 -- could not have been hidden in the generic by a use clause,
7689 -- and therefore remain visible. Other compilation units whose
7690 -- entities appear in Standard must be hidden in an instance.
7692 -- To determine whether an entity is external to the instance
7693 -- we compare the scope depth of its scope with that of the
7694 -- current instance. However, a generic actual of a subprogram
7695 -- instance is declared in the wrapper package but will not be
7696 -- hidden by a use-visible entity. similarly, an entity that is
7697 -- declared in an enclosing instance will not be hidden by an
7698 -- an entity declared in a generic actual, which can only have
7699 -- been use-visible in the generic and will not have hidden the
7700 -- entity in the generic parent.
7702 -- If Id is called Standard, the predefined package with the
7703 -- same name is in the homonym chain. It has to be ignored
7704 -- because it has no defined scope (being the only entity in
7705 -- the system with this mandated behavior).
7707 elsif not Is_Hidden (Id)
7708 and then Present (Scope (Prev))
7709 and then not Is_Wrapper_Package (Scope (Prev))
7710 and then Scope_Depth (Scope (Prev)) <
7711 Scope_Depth (Current_Instance)
7712 and then (Scope (Prev) /= Standard_Standard
7713 or else Sloc (Prev) > Standard_Location)
7715 if In_Open_Scopes (Scope (Prev))
7716 and then Is_Generic_Instance (Scope (Prev))
7717 and then Present (Associated_Formal_Package (P))
7722 Set_Is_Potentially_Use_Visible (Id);
7723 Set_Is_Immediately_Visible (Prev, False);
7724 Append_Elmt (Prev, Hidden_By_Use_Clause (N));
7728 -- A user-defined operator is not use-visible if the predefined
7729 -- operator for the type is immediately visible, which is the case
7730 -- if the type of the operand is in an open scope. This does not
7731 -- apply to user-defined operators that have operands of different
7732 -- types, because the predefined mixed mode operations (multiply
7733 -- and divide) apply to universal types and do not hide anything.
7735 elsif Ekind (Prev) = E_Operator
7736 and then Operator_Matches_Spec (Prev, Id)
7737 and then In_Open_Scopes
7738 (Scope (Base_Type (Etype (First_Formal (Id)))))
7739 and then (No (Next_Formal (First_Formal (Id)))
7740 or else Etype (First_Formal (Id))
7741 = Etype (Next_Formal (First_Formal (Id)))
7742 or else Chars (Prev) = Name_Op_Expon)
7744 goto Next_Usable_Entity;
7746 -- In an instance, two homonyms may become use_visible through the
7747 -- actuals of distinct formal packages. In the generic, only the
7748 -- current one would have been visible, so make the other one
7751 elsif Present (Current_Instance)
7752 and then Is_Potentially_Use_Visible (Prev)
7753 and then not Is_Overloadable (Prev)
7754 and then Scope (Id) /= Scope (Prev)
7755 and then Used_As_Generic_Actual (Scope (Prev))
7756 and then Used_As_Generic_Actual (Scope (Id))
7757 and then not In_Same_List (Current_Use_Clause (Scope (Prev)),
7758 Current_Use_Clause (Scope (Id)))
7760 Set_Is_Potentially_Use_Visible (Prev, False);
7761 Append_Elmt (Prev, Hidden_By_Use_Clause (N));
7764 Prev := Homonym (Prev);
7767 -- On exit, we know entity is not hidden, unless it is private
7769 if not Is_Hidden (Id)
7770 and then ((not Is_Child_Unit (Id))
7771 or else Is_Visible_Child_Unit (Id))
7773 Set_Is_Potentially_Use_Visible (Id);
7775 if Is_Private_Type (Id)
7776 and then Present (Full_View (Id))
7778 Set_Is_Potentially_Use_Visible (Full_View (Id));
7782 <<Next_Usable_Entity>>
7786 -- Child units are also made use-visible by a use clause, but they may
7787 -- appear after all visible declarations in the parent entity list.
7789 while Present (Id) loop
7790 if Is_Child_Unit (Id)
7791 and then Is_Visible_Child_Unit (Id)
7793 Set_Is_Potentially_Use_Visible (Id);
7799 if Chars (Real_P) = Name_System
7800 and then Scope (Real_P) = Standard_Standard
7801 and then Present_System_Aux (N)
7803 Use_One_Package (System_Aux_Id, N);
7806 end Use_One_Package;
7812 procedure Use_One_Type (Id : Node_Id; Installed : Boolean := False) is
7814 Is_Known_Used : Boolean;
7818 function Spec_Reloaded_For_Body return Boolean;
7819 -- Determine whether the compilation unit is a package body and the use
7820 -- type clause is in the spec of the same package. Even though the spec
7821 -- was analyzed first, its context is reloaded when analysing the body.
7823 procedure Use_Class_Wide_Operations (Typ : Entity_Id);
7824 -- AI05-150: if the use_type_clause carries the "all" qualifier,
7825 -- class-wide operations of ancestor types are use-visible if the
7826 -- ancestor type is visible.
7828 ----------------------------
7829 -- Spec_Reloaded_For_Body --
7830 ----------------------------
7832 function Spec_Reloaded_For_Body return Boolean is
7834 if Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Body then
7836 Spec : constant Node_Id :=
7837 Parent (List_Containing (Parent (Id)));
7840 Nkind (Spec) = N_Package_Specification
7841 and then Corresponding_Body (Parent (Spec)) =
7842 Cunit_Entity (Current_Sem_Unit);
7847 end Spec_Reloaded_For_Body;
7849 -------------------------------
7850 -- Use_Class_Wide_Operations --
7851 -------------------------------
7853 procedure Use_Class_Wide_Operations (Typ : Entity_Id) is
7857 function Is_Class_Wide_Operation_Of
7859 T : Entity_Id) return Boolean;
7860 -- Determine whether a subprogram has a class-wide parameter or
7861 -- result that is T'Class.
7863 ---------------------------------
7864 -- Is_Class_Wide_Operation_Of --
7865 ---------------------------------
7867 function Is_Class_Wide_Operation_Of
7869 T : Entity_Id) return Boolean
7874 Formal := First_Formal (Op);
7875 while Present (Formal) loop
7876 if Etype (Formal) = Class_Wide_Type (T) then
7879 Next_Formal (Formal);
7882 if Etype (Op) = Class_Wide_Type (T) then
7887 end Is_Class_Wide_Operation_Of;
7889 -- Start of processing for Use_Class_Wide_Operations
7892 Scop := Scope (Typ);
7893 if not Is_Hidden (Scop) then
7894 Ent := First_Entity (Scop);
7895 while Present (Ent) loop
7896 if Is_Overloadable (Ent)
7897 and then Is_Class_Wide_Operation_Of (Ent, Typ)
7898 and then not Is_Potentially_Use_Visible (Ent)
7900 Set_Is_Potentially_Use_Visible (Ent);
7901 Append_Elmt (Ent, Used_Operations (Parent (Id)));
7908 if Is_Derived_Type (Typ) then
7909 Use_Class_Wide_Operations (Etype (Base_Type (Typ)));
7911 end Use_Class_Wide_Operations;
7913 -- Start of processing for Use_One_Type;
7916 -- It is the type determined by the subtype mark (8.4(8)) whose
7917 -- operations become potentially use-visible.
7919 T := Base_Type (Entity (Id));
7921 -- Either the type itself is used, the package where it is declared
7922 -- is in use or the entity is declared in the current package, thus
7927 or else In_Use (Scope (T))
7928 or else Scope (T) = Current_Scope;
7930 Set_Redundant_Use (Id,
7931 Is_Known_Used or else Is_Potentially_Use_Visible (T));
7933 if Ekind (T) = E_Incomplete_Type then
7934 Error_Msg_N ("premature usage of incomplete type", Id);
7936 elsif In_Open_Scopes (Scope (T)) then
7939 -- A limited view cannot appear in a use_type clause. However, an access
7940 -- type whose designated type is limited has the flag but is not itself
7941 -- a limited view unless we only have a limited view of its enclosing
7944 elsif From_With_Type (T)
7945 and then From_With_Type (Scope (T))
7948 ("incomplete type from limited view "
7949 & "cannot appear in use clause", Id);
7951 -- If the subtype mark designates a subtype in a different package,
7952 -- we have to check that the parent type is visible, otherwise the
7953 -- use type clause is a noop. Not clear how to do that???
7955 elsif not Redundant_Use (Id) then
7958 -- If T is tagged, primitive operators on class-wide operands
7959 -- are also available.
7961 if Is_Tagged_Type (T) then
7962 Set_In_Use (Class_Wide_Type (T));
7965 Set_Current_Use_Clause (T, Parent (Id));
7967 -- Iterate over primitive operations of the type. If an operation is
7968 -- already use_visible, it is the result of a previous use_clause,
7969 -- and already appears on the corresponding entity chain. If the
7970 -- clause is being reinstalled, operations are already use-visible.
7976 Op_List := Collect_Primitive_Operations (T);
7977 Elmt := First_Elmt (Op_List);
7978 while Present (Elmt) loop
7979 if (Nkind (Node (Elmt)) = N_Defining_Operator_Symbol
7980 or else Chars (Node (Elmt)) in Any_Operator_Name)
7981 and then not Is_Hidden (Node (Elmt))
7982 and then not Is_Potentially_Use_Visible (Node (Elmt))
7984 Set_Is_Potentially_Use_Visible (Node (Elmt));
7985 Append_Elmt (Node (Elmt), Used_Operations (Parent (Id)));
7987 elsif Ada_Version >= Ada_2012
7988 and then All_Present (Parent (Id))
7989 and then not Is_Hidden (Node (Elmt))
7990 and then not Is_Potentially_Use_Visible (Node (Elmt))
7992 Set_Is_Potentially_Use_Visible (Node (Elmt));
7993 Append_Elmt (Node (Elmt), Used_Operations (Parent (Id)));
8000 if Ada_Version >= Ada_2012
8001 and then All_Present (Parent (Id))
8002 and then Is_Tagged_Type (T)
8004 Use_Class_Wide_Operations (T);
8008 -- If warning on redundant constructs, check for unnecessary WITH
8010 if Warn_On_Redundant_Constructs
8011 and then Is_Known_Used
8013 -- with P; with P; use P;
8014 -- package P is package X is package body X is
8015 -- type T ... use P.T;
8017 -- The compilation unit is the body of X. GNAT first compiles the
8018 -- spec of X, then proceeds to the body. At that point P is marked
8019 -- as use visible. The analysis then reinstalls the spec along with
8020 -- its context. The use clause P.T is now recognized as redundant,
8021 -- but in the wrong context. Do not emit a warning in such cases.
8022 -- Do not emit a warning either if we are in an instance, there is
8023 -- no redundancy between an outer use_clause and one that appears
8024 -- within the generic.
8026 and then not Spec_Reloaded_For_Body
8027 and then not In_Instance
8029 -- The type already has a use clause
8033 -- Case where we know the current use clause for the type
8035 if Present (Current_Use_Clause (T)) then
8036 Use_Clause_Known : declare
8037 Clause1 : constant Node_Id := Parent (Id);
8038 Clause2 : constant Node_Id := Current_Use_Clause (T);
8045 function Entity_Of_Unit (U : Node_Id) return Entity_Id;
8046 -- Return the appropriate entity for determining which unit
8047 -- has a deeper scope: the defining entity for U, unless U
8048 -- is a package instance, in which case we retrieve the
8049 -- entity of the instance spec.
8051 --------------------
8052 -- Entity_Of_Unit --
8053 --------------------
8055 function Entity_Of_Unit (U : Node_Id) return Entity_Id is
8057 if Nkind (U) = N_Package_Instantiation
8058 and then Analyzed (U)
8060 return Defining_Entity (Instance_Spec (U));
8062 return Defining_Entity (U);
8066 -- Start of processing for Use_Clause_Known
8069 -- If both current use type clause and the use type clause
8070 -- for the type are at the compilation unit level, one of
8071 -- the units must be an ancestor of the other, and the
8072 -- warning belongs on the descendant.
8074 if Nkind (Parent (Clause1)) = N_Compilation_Unit
8076 Nkind (Parent (Clause2)) = N_Compilation_Unit
8079 -- If the unit is a subprogram body that acts as spec,
8080 -- the context clause is shared with the constructed
8081 -- subprogram spec. Clearly there is no redundancy.
8083 if Clause1 = Clause2 then
8087 Unit1 := Unit (Parent (Clause1));
8088 Unit2 := Unit (Parent (Clause2));
8090 -- If both clauses are on same unit, or one is the body
8091 -- of the other, or one of them is in a subunit, report
8092 -- redundancy on the later one.
8094 if Unit1 = Unit2 then
8095 Error_Msg_Sloc := Sloc (Current_Use_Clause (T));
8096 Error_Msg_NE -- CODEFIX
8097 ("& is already use-visible through previous "
8098 & "use_type_clause #?", Clause1, T);
8101 elsif Nkind (Unit1) = N_Subunit then
8102 Error_Msg_Sloc := Sloc (Current_Use_Clause (T));
8103 Error_Msg_NE -- CODEFIX
8104 ("& is already use-visible through previous "
8105 & "use_type_clause #?", Clause1, T);
8108 elsif Nkind_In (Unit2, N_Package_Body, N_Subprogram_Body)
8109 and then Nkind (Unit1) /= Nkind (Unit2)
8110 and then Nkind (Unit1) /= N_Subunit
8112 Error_Msg_Sloc := Sloc (Clause1);
8113 Error_Msg_NE -- CODEFIX
8114 ("& is already use-visible through previous "
8115 & "use_type_clause #?", Current_Use_Clause (T), T);
8119 -- There is a redundant use type clause in a child unit.
8120 -- Determine which of the units is more deeply nested.
8121 -- If a unit is a package instance, retrieve the entity
8122 -- and its scope from the instance spec.
8124 Ent1 := Entity_Of_Unit (Unit1);
8125 Ent2 := Entity_Of_Unit (Unit2);
8127 if Scope (Ent2) = Standard_Standard then
8128 Error_Msg_Sloc := Sloc (Current_Use_Clause (T));
8131 elsif Scope (Ent1) = Standard_Standard then
8132 Error_Msg_Sloc := Sloc (Id);
8135 -- If both units are child units, we determine which one
8136 -- is the descendant by the scope distance to the
8137 -- ultimate parent unit.
8147 and then Present (S2)
8148 and then S1 /= Standard_Standard
8149 and then S2 /= Standard_Standard
8155 if S1 = Standard_Standard then
8156 Error_Msg_Sloc := Sloc (Id);
8159 Error_Msg_Sloc := Sloc (Current_Use_Clause (T));
8165 Error_Msg_NE -- CODEFIX
8166 ("& is already use-visible through previous "
8167 & "use_type_clause #?", Err_No, Id);
8169 -- Case where current use type clause and the use type
8170 -- clause for the type are not both at the compilation unit
8171 -- level. In this case we don't have location information.
8174 Error_Msg_NE -- CODEFIX
8175 ("& is already use-visible through previous "
8176 & "use type clause?", Id, T);
8178 end Use_Clause_Known;
8180 -- Here if Current_Use_Clause is not set for T, another case
8181 -- where we do not have the location information available.
8184 Error_Msg_NE -- CODEFIX
8185 ("& is already use-visible through previous "
8186 & "use type clause?", Id, T);
8189 -- The package where T is declared is already used
8191 elsif In_Use (Scope (T)) then
8192 Error_Msg_Sloc := Sloc (Current_Use_Clause (Scope (T)));
8193 Error_Msg_NE -- CODEFIX
8194 ("& is already use-visible through package use clause #?",
8197 -- The current scope is the package where T is declared
8200 Error_Msg_Node_2 := Scope (T);
8201 Error_Msg_NE -- CODEFIX
8202 ("& is already use-visible inside package &?", Id, T);
8211 procedure Write_Info is
8212 Id : Entity_Id := First_Entity (Current_Scope);
8215 -- No point in dumping standard entities
8217 if Current_Scope = Standard_Standard then
8221 Write_Str ("========================================================");
8223 Write_Str (" Defined Entities in ");
8224 Write_Name (Chars (Current_Scope));
8226 Write_Str ("========================================================");
8230 Write_Str ("-- none --");
8234 while Present (Id) loop
8235 Write_Entity_Info (Id, " ");
8240 if Scope (Current_Scope) = Standard_Standard then
8242 -- Print information on the current unit itself
8244 Write_Entity_Info (Current_Scope, " ");
8257 for J in reverse 1 .. Scope_Stack.Last loop
8258 S := Scope_Stack.Table (J).Entity;
8259 Write_Int (Int (S));
8260 Write_Str (" === ");
8261 Write_Name (Chars (S));
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