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
2429 -- This is an implicit reference to the default actual
2431 Generate_Reference (Old_S, Nam, Typ => 'i', Force => True);
2434 Generate_Reference (Old_S, Nam);
2437 -- For a renaming-as-body, require subtype conformance, but if the
2438 -- declaration being completed has not been frozen, then inherit the
2439 -- convention of the renamed subprogram prior to checking conformance
2440 -- (unless the renaming has an explicit convention established; the
2441 -- rule stated in the RM doesn't seem to address this ???).
2443 if Present (Rename_Spec) then
2444 Generate_Reference (Rename_Spec, Defining_Entity (Spec), 'b');
2445 Style.Check_Identifier (Defining_Entity (Spec), Rename_Spec);
2447 if not Is_Frozen (Rename_Spec) then
2448 if not Has_Convention_Pragma (Rename_Spec) then
2449 Set_Convention (New_S, Convention (Old_S));
2452 if Ekind (Old_S) /= E_Operator then
2453 Check_Mode_Conformant (New_S, Old_S, Spec);
2456 if Original_Subprogram (Old_S) = Rename_Spec then
2457 Error_Msg_N ("unfrozen subprogram cannot rename itself ", N);
2460 Check_Subtype_Conformant (New_S, Old_S, Spec);
2463 Check_Frozen_Renaming (N, Rename_Spec);
2465 -- Check explicitly that renamed entity is not intrinsic, because
2466 -- in a generic the renamed body is not built. In this case,
2467 -- the renaming_as_body is a completion.
2469 if Inside_A_Generic then
2470 if Is_Frozen (Rename_Spec)
2471 and then Is_Intrinsic_Subprogram (Old_S)
2474 ("subprogram in renaming_as_body cannot be intrinsic",
2478 Set_Has_Completion (Rename_Spec);
2481 elsif Ekind (Old_S) /= E_Operator then
2483 -- If this a defaulted subprogram for a class-wide actual there is
2484 -- no check for mode conformance, given that the signatures don't
2485 -- match (the source mentions T but the actual mentions T'Class).
2490 Check_Mode_Conformant (New_S, Old_S);
2494 and then Error_Posted (New_S)
2496 Error_Msg_NE ("invalid actual subprogram: & #!", N, Old_S);
2500 if No (Rename_Spec) then
2502 -- The parameter profile of the new entity is that of the renamed
2503 -- entity: the subtypes given in the specification are irrelevant.
2505 Inherit_Renamed_Profile (New_S, Old_S);
2507 -- A call to the subprogram is transformed into a call to the
2508 -- renamed entity. This is transitive if the renamed entity is
2509 -- itself a renaming.
2511 if Present (Alias (Old_S)) then
2512 Set_Alias (New_S, Alias (Old_S));
2514 Set_Alias (New_S, Old_S);
2517 -- Note that we do not set Is_Intrinsic_Subprogram if we have a
2518 -- renaming as body, since the entity in this case is not an
2519 -- intrinsic (it calls an intrinsic, but we have a real body for
2520 -- this call, and it is in this body that the required intrinsic
2521 -- processing will take place).
2523 -- Also, if this is a renaming of inequality, the renamed operator
2524 -- is intrinsic, but what matters is the corresponding equality
2525 -- operator, which may be user-defined.
2527 Set_Is_Intrinsic_Subprogram
2529 Is_Intrinsic_Subprogram (Old_S)
2531 (Chars (Old_S) /= Name_Op_Ne
2532 or else Ekind (Old_S) = E_Operator
2534 Is_Intrinsic_Subprogram
2535 (Corresponding_Equality (Old_S))));
2537 if Ekind (Alias (New_S)) = E_Operator then
2538 Set_Has_Delayed_Freeze (New_S, False);
2541 -- If the renaming corresponds to an association for an abstract
2542 -- formal subprogram, then various attributes must be set to
2543 -- indicate that the renaming is an abstract dispatching operation
2544 -- with a controlling type.
2546 if Is_Actual and then Is_Abstract_Subprogram (Formal_Spec) then
2548 -- Mark the renaming as abstract here, so Find_Dispatching_Type
2549 -- see it as corresponding to a generic association for a
2550 -- formal abstract subprogram
2552 Set_Is_Abstract_Subprogram (New_S);
2555 New_S_Ctrl_Type : constant Entity_Id :=
2556 Find_Dispatching_Type (New_S);
2557 Old_S_Ctrl_Type : constant Entity_Id :=
2558 Find_Dispatching_Type (Old_S);
2561 if Old_S_Ctrl_Type /= New_S_Ctrl_Type then
2563 ("actual must be dispatching subprogram for type&",
2564 Nam, New_S_Ctrl_Type);
2567 Set_Is_Dispatching_Operation (New_S);
2568 Check_Controlling_Formals (New_S_Ctrl_Type, New_S);
2570 -- If the actual in the formal subprogram is itself a
2571 -- formal abstract subprogram association, there's no
2572 -- dispatch table component or position to inherit.
2574 if Present (DTC_Entity (Old_S)) then
2575 Set_DTC_Entity (New_S, DTC_Entity (Old_S));
2576 Set_DT_Position (New_S, DT_Position (Old_S));
2584 and then (Old_S = New_S
2585 or else (Nkind (Nam) /= N_Expanded_Name
2586 and then Chars (Old_S) = Chars (New_S)))
2588 Error_Msg_N ("subprogram cannot rename itself", N);
2591 Set_Convention (New_S, Convention (Old_S));
2593 if Is_Abstract_Subprogram (Old_S) then
2594 if Present (Rename_Spec) then
2596 ("a renaming-as-body cannot rename an abstract subprogram",
2598 Set_Has_Completion (Rename_Spec);
2600 Set_Is_Abstract_Subprogram (New_S);
2604 Check_Library_Unit_Renaming (N, Old_S);
2606 -- Pathological case: procedure renames entry in the scope of its
2607 -- task. Entry is given by simple name, but body must be built for
2608 -- procedure. Of course if called it will deadlock.
2610 if Ekind (Old_S) = E_Entry then
2611 Set_Has_Completion (New_S, False);
2612 Set_Alias (New_S, Empty);
2616 Freeze_Before (N, Old_S);
2617 Set_Has_Delayed_Freeze (New_S, False);
2618 Freeze_Before (N, New_S);
2620 -- An abstract subprogram is only allowed as an actual in the case
2621 -- where the formal subprogram is also abstract.
2623 if (Ekind (Old_S) = E_Procedure or else Ekind (Old_S) = E_Function)
2624 and then Is_Abstract_Subprogram (Old_S)
2625 and then not Is_Abstract_Subprogram (Formal_Spec)
2628 ("abstract subprogram not allowed as generic actual", Nam);
2633 -- A common error is to assume that implicit operators for types are
2634 -- defined in Standard, or in the scope of a subtype. In those cases
2635 -- where the renamed entity is given with an expanded name, it is
2636 -- worth mentioning that operators for the type are not declared in
2637 -- the scope given by the prefix.
2639 if Nkind (Nam) = N_Expanded_Name
2640 and then Nkind (Selector_Name (Nam)) = N_Operator_Symbol
2641 and then Scope (Entity (Nam)) = Standard_Standard
2644 T : constant Entity_Id :=
2645 Base_Type (Etype (First_Formal (New_S)));
2647 Error_Msg_Node_2 := Prefix (Nam);
2649 ("operator for type& is not declared in&", Prefix (Nam), T);
2654 ("no visible subprogram matches the specification for&",
2658 if Present (Candidate_Renaming) then
2665 F1 := First_Formal (Candidate_Renaming);
2666 F2 := First_Formal (New_S);
2667 T1 := First_Subtype (Etype (F1));
2669 while Present (F1) and then Present (F2) loop
2674 if Present (F1) and then Present (Default_Value (F1)) then
2675 if Present (Next_Formal (F1)) then
2677 ("\missing specification for &" &
2678 " and other formals with defaults", Spec, F1);
2681 ("\missing specification for &", Spec, F1);
2685 if Nkind (Nam) = N_Operator_Symbol
2686 and then From_Default (N)
2688 Error_Msg_Node_2 := T1;
2690 ("default & on & is not directly visible",
2697 -- Ada 2005 AI 404: if the new subprogram is dispatching, verify that
2698 -- controlling access parameters are known non-null for the renamed
2699 -- subprogram. Test also applies to a subprogram instantiation that
2700 -- is dispatching. Test is skipped if some previous error was detected
2701 -- that set Old_S to Any_Id.
2703 if Ada_Version >= Ada_2005
2704 and then Old_S /= Any_Id
2705 and then not Is_Dispatching_Operation (Old_S)
2706 and then Is_Dispatching_Operation (New_S)
2713 Old_F := First_Formal (Old_S);
2714 New_F := First_Formal (New_S);
2715 while Present (Old_F) loop
2716 if Ekind (Etype (Old_F)) = E_Anonymous_Access_Type
2717 and then Is_Controlling_Formal (New_F)
2718 and then not Can_Never_Be_Null (Old_F)
2720 Error_Msg_N ("access parameter is controlling,", New_F);
2722 ("\corresponding parameter of& "
2723 & "must be explicitly null excluding", New_F, Old_S);
2726 Next_Formal (Old_F);
2727 Next_Formal (New_F);
2732 -- A useful warning, suggested by Ada Bug Finder (Ada-Europe 2005)
2733 -- is to warn if an operator is being renamed as a different operator.
2734 -- If the operator is predefined, examine the kind of the entity, not
2735 -- the abbreviated declaration in Standard.
2737 if Comes_From_Source (N)
2738 and then Present (Old_S)
2740 (Nkind (Old_S) = N_Defining_Operator_Symbol
2741 or else Ekind (Old_S) = E_Operator)
2742 and then Nkind (New_S) = N_Defining_Operator_Symbol
2743 and then Chars (Old_S) /= Chars (New_S)
2746 ("?& is being renamed as a different operator", N, Old_S);
2749 -- Check for renaming of obsolescent subprogram
2751 Check_Obsolescent_2005_Entity (Entity (Nam), Nam);
2753 -- Another warning or some utility: if the new subprogram as the same
2754 -- name as the old one, the old one is not hidden by an outer homograph,
2755 -- the new one is not a public symbol, and the old one is otherwise
2756 -- directly visible, the renaming is superfluous.
2758 if Chars (Old_S) = Chars (New_S)
2759 and then Comes_From_Source (N)
2760 and then Scope (Old_S) /= Standard_Standard
2761 and then Warn_On_Redundant_Constructs
2763 (Is_Immediately_Visible (Old_S)
2764 or else Is_Potentially_Use_Visible (Old_S))
2765 and then Is_Overloadable (Current_Scope)
2766 and then Chars (Current_Scope) /= Chars (Old_S)
2769 ("?redundant renaming, entity is directly visible", Name (N));
2772 Ada_Version := Save_AV;
2773 Ada_Version_Explicit := Save_AV_Exp;
2774 end Analyze_Subprogram_Renaming;
2776 -------------------------
2777 -- Analyze_Use_Package --
2778 -------------------------
2780 -- Resolve the package names in the use clause, and make all the visible
2781 -- entities defined in the package potentially use-visible. If the package
2782 -- is already in use from a previous use clause, its visible entities are
2783 -- already use-visible. In that case, mark the occurrence as a redundant
2784 -- use. If the package is an open scope, i.e. if the use clause occurs
2785 -- within the package itself, ignore it.
2787 procedure Analyze_Use_Package (N : Node_Id) is
2788 Pack_Name : Node_Id;
2791 -- Start of processing for Analyze_Use_Package
2794 Check_SPARK_Restriction ("use clause is not allowed", N);
2796 Set_Hidden_By_Use_Clause (N, No_Elist);
2798 -- Use clause not allowed in a spec of a predefined package declaration
2799 -- except that packages whose file name starts a-n are OK (these are
2800 -- children of Ada.Numerics, which are never loaded by Rtsfind).
2802 if Is_Predefined_File_Name (Unit_File_Name (Current_Sem_Unit))
2803 and then Name_Buffer (1 .. 3) /= "a-n"
2805 Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Declaration
2807 Error_Msg_N ("use clause not allowed in predefined spec", N);
2810 -- Chain clause to list of use clauses in current scope
2812 if Nkind (Parent (N)) /= N_Compilation_Unit then
2813 Chain_Use_Clause (N);
2816 -- Loop through package names to identify referenced packages
2818 Pack_Name := First (Names (N));
2819 while Present (Pack_Name) loop
2820 Analyze (Pack_Name);
2822 if Nkind (Parent (N)) = N_Compilation_Unit
2823 and then Nkind (Pack_Name) = N_Expanded_Name
2829 Pref := Prefix (Pack_Name);
2830 while Nkind (Pref) = N_Expanded_Name loop
2831 Pref := Prefix (Pref);
2834 if Entity (Pref) = Standard_Standard then
2836 ("predefined package Standard cannot appear"
2837 & " in a context clause", Pref);
2845 -- Loop through package names to mark all entities as potentially
2848 Pack_Name := First (Names (N));
2849 while Present (Pack_Name) loop
2850 if Is_Entity_Name (Pack_Name) then
2851 Pack := Entity (Pack_Name);
2853 if Ekind (Pack) /= E_Package
2854 and then Etype (Pack) /= Any_Type
2856 if Ekind (Pack) = E_Generic_Package then
2857 Error_Msg_N -- CODEFIX
2858 ("a generic package is not allowed in a use clause",
2861 Error_Msg_N ("& is not a usable package", Pack_Name);
2865 if Nkind (Parent (N)) = N_Compilation_Unit then
2866 Check_In_Previous_With_Clause (N, Pack_Name);
2869 if Applicable_Use (Pack_Name) then
2870 Use_One_Package (Pack, N);
2874 -- Report error because name denotes something other than a package
2877 Error_Msg_N ("& is not a package", Pack_Name);
2882 end Analyze_Use_Package;
2884 ----------------------
2885 -- Analyze_Use_Type --
2886 ----------------------
2888 procedure Analyze_Use_Type (N : Node_Id) is
2893 Set_Hidden_By_Use_Clause (N, No_Elist);
2895 -- Chain clause to list of use clauses in current scope
2897 if Nkind (Parent (N)) /= N_Compilation_Unit then
2898 Chain_Use_Clause (N);
2901 -- If the Used_Operations list is already initialized, the clause has
2902 -- been analyzed previously, and it is begin reinstalled, for example
2903 -- when the clause appears in a package spec and we are compiling the
2904 -- corresponding package body. In that case, make the entities on the
2905 -- existing list use_visible, and mark the corresponding types In_Use.
2907 if Present (Used_Operations (N)) then
2913 Mark := First (Subtype_Marks (N));
2914 while Present (Mark) loop
2915 Use_One_Type (Mark, Installed => True);
2919 Elmt := First_Elmt (Used_Operations (N));
2920 while Present (Elmt) loop
2921 Set_Is_Potentially_Use_Visible (Node (Elmt));
2929 -- Otherwise, create new list and attach to it the operations that
2930 -- are made use-visible by the clause.
2932 Set_Used_Operations (N, New_Elmt_List);
2933 Id := First (Subtype_Marks (N));
2934 while Present (Id) loop
2938 if E /= Any_Type then
2941 if Nkind (Parent (N)) = N_Compilation_Unit then
2942 if Nkind (Id) = N_Identifier then
2943 Error_Msg_N ("type is not directly visible", Id);
2945 elsif Is_Child_Unit (Scope (E))
2946 and then Scope (E) /= System_Aux_Id
2948 Check_In_Previous_With_Clause (N, Prefix (Id));
2953 -- If the use_type_clause appears in a compilation unit context,
2954 -- check whether it comes from a unit that may appear in a
2955 -- limited_with_clause, for a better error message.
2957 if Nkind (Parent (N)) = N_Compilation_Unit
2958 and then Nkind (Id) /= N_Identifier
2964 function Mentioned (Nam : Node_Id) return Boolean;
2965 -- Check whether the prefix of expanded name for the type
2966 -- appears in the prefix of some limited_with_clause.
2972 function Mentioned (Nam : Node_Id) return Boolean is
2974 return Nkind (Name (Item)) = N_Selected_Component
2976 Chars (Prefix (Name (Item))) = Chars (Nam);
2980 Pref := Prefix (Id);
2981 Item := First (Context_Items (Parent (N)));
2983 while Present (Item) and then Item /= N loop
2984 if Nkind (Item) = N_With_Clause
2985 and then Limited_Present (Item)
2986 and then Mentioned (Pref)
2989 (Get_Msg_Id, "premature usage of incomplete type");
3000 end Analyze_Use_Type;
3002 --------------------
3003 -- Applicable_Use --
3004 --------------------
3006 function Applicable_Use (Pack_Name : Node_Id) return Boolean is
3007 Pack : constant Entity_Id := Entity (Pack_Name);
3010 if In_Open_Scopes (Pack) then
3011 if Warn_On_Redundant_Constructs
3012 and then Pack = Current_Scope
3014 Error_Msg_NE -- CODEFIX
3015 ("& is already use-visible within itself?", Pack_Name, Pack);
3020 elsif In_Use (Pack) then
3021 Note_Redundant_Use (Pack_Name);
3024 elsif Present (Renamed_Object (Pack))
3025 and then In_Use (Renamed_Object (Pack))
3027 Note_Redundant_Use (Pack_Name);
3035 ------------------------
3036 -- Attribute_Renaming --
3037 ------------------------
3039 procedure Attribute_Renaming (N : Node_Id) is
3040 Loc : constant Source_Ptr := Sloc (N);
3041 Nam : constant Node_Id := Name (N);
3042 Spec : constant Node_Id := Specification (N);
3043 New_S : constant Entity_Id := Defining_Unit_Name (Spec);
3044 Aname : constant Name_Id := Attribute_Name (Nam);
3046 Form_Num : Nat := 0;
3047 Expr_List : List_Id := No_List;
3049 Attr_Node : Node_Id;
3050 Body_Node : Node_Id;
3051 Param_Spec : Node_Id;
3054 Generate_Definition (New_S);
3056 -- This procedure is called in the context of subprogram renaming, and
3057 -- thus the attribute must be one that is a subprogram. All of those
3058 -- have at least one formal parameter, with the singular exception of
3059 -- AST_Entry (which is a real oddity, it is odd that this can be renamed
3062 if not Is_Non_Empty_List (Parameter_Specifications (Spec)) then
3063 if Aname /= Name_AST_Entry then
3065 ("subprogram renaming an attribute must have formals", N);
3070 Param_Spec := First (Parameter_Specifications (Spec));
3071 while Present (Param_Spec) loop
3072 Form_Num := Form_Num + 1;
3074 if Nkind (Parameter_Type (Param_Spec)) /= N_Access_Definition then
3075 Find_Type (Parameter_Type (Param_Spec));
3077 -- The profile of the new entity denotes the base type (s) of
3078 -- the types given in the specification. For access parameters
3079 -- there are no subtypes involved.
3081 Rewrite (Parameter_Type (Param_Spec),
3083 (Base_Type (Entity (Parameter_Type (Param_Spec))), Loc));
3086 if No (Expr_List) then
3087 Expr_List := New_List;
3090 Append_To (Expr_List,
3091 Make_Identifier (Loc,
3092 Chars => Chars (Defining_Identifier (Param_Spec))));
3094 -- The expressions in the attribute reference are not freeze
3095 -- points. Neither is the attribute as a whole, see below.
3097 Set_Must_Not_Freeze (Last (Expr_List));
3102 -- Immediate error if too many formals. Other mismatches in number or
3103 -- types of parameters are detected when we analyze the body of the
3104 -- subprogram that we construct.
3106 if Form_Num > 2 then
3107 Error_Msg_N ("too many formals for attribute", N);
3109 -- Error if the attribute reference has expressions that look like
3110 -- formal parameters.
3112 elsif Present (Expressions (Nam)) then
3113 Error_Msg_N ("illegal expressions in attribute reference", Nam);
3116 Aname = Name_Compose or else
3117 Aname = Name_Exponent or else
3118 Aname = Name_Leading_Part or else
3119 Aname = Name_Pos or else
3120 Aname = Name_Round or else
3121 Aname = Name_Scaling or else
3124 if Nkind (N) = N_Subprogram_Renaming_Declaration
3125 and then Present (Corresponding_Formal_Spec (N))
3128 ("generic actual cannot be attribute involving universal type",
3132 ("attribute involving a universal type cannot be renamed",
3137 -- AST_Entry is an odd case. It doesn't really make much sense to allow
3138 -- it to be renamed, but that's the DEC rule, so we have to do it right.
3139 -- The point is that the AST_Entry call should be made now, and what the
3140 -- function will return is the returned value.
3142 -- Note that there is no Expr_List in this case anyway
3144 if Aname = Name_AST_Entry then
3146 Ent : constant Entity_Id := Make_Temporary (Loc, 'R', Nam);
3151 Make_Object_Declaration (Loc,
3152 Defining_Identifier => Ent,
3153 Object_Definition =>
3154 New_Occurrence_Of (RTE (RE_AST_Handler), Loc),
3156 Constant_Present => True);
3158 Set_Assignment_OK (Decl, True);
3159 Insert_Action (N, Decl);
3160 Attr_Node := Make_Identifier (Loc, Chars (Ent));
3163 -- For all other attributes, we rewrite the attribute node to have
3164 -- a list of expressions corresponding to the subprogram formals.
3165 -- A renaming declaration is not a freeze point, and the analysis of
3166 -- the attribute reference should not freeze the type of the prefix.
3170 Make_Attribute_Reference (Loc,
3171 Prefix => Prefix (Nam),
3172 Attribute_Name => Aname,
3173 Expressions => Expr_List);
3175 Set_Must_Not_Freeze (Attr_Node);
3176 Set_Must_Not_Freeze (Prefix (Nam));
3179 -- Case of renaming a function
3181 if Nkind (Spec) = N_Function_Specification then
3182 if Is_Procedure_Attribute_Name (Aname) then
3183 Error_Msg_N ("attribute can only be renamed as procedure", Nam);
3187 Find_Type (Result_Definition (Spec));
3188 Rewrite (Result_Definition (Spec),
3190 Base_Type (Entity (Result_Definition (Spec))), Loc));
3193 Make_Subprogram_Body (Loc,
3194 Specification => Spec,
3195 Declarations => New_List,
3196 Handled_Statement_Sequence =>
3197 Make_Handled_Sequence_Of_Statements (Loc,
3198 Statements => New_List (
3199 Make_Simple_Return_Statement (Loc,
3200 Expression => Attr_Node))));
3202 -- Case of renaming a procedure
3205 if not Is_Procedure_Attribute_Name (Aname) then
3206 Error_Msg_N ("attribute can only be renamed as function", Nam);
3211 Make_Subprogram_Body (Loc,
3212 Specification => Spec,
3213 Declarations => New_List,
3214 Handled_Statement_Sequence =>
3215 Make_Handled_Sequence_Of_Statements (Loc,
3216 Statements => New_List (Attr_Node)));
3219 -- In case of tagged types we add the body of the generated function to
3220 -- the freezing actions of the type (because in the general case such
3221 -- type is still not frozen). We exclude from this processing generic
3222 -- formal subprograms found in instantiations and AST_Entry renamings.
3224 -- We must exclude VM targets because entity AST_Handler is defined in
3225 -- package System.Aux_Dec which is not available in those platforms.
3227 if VM_Target = No_VM
3228 and then not Present (Corresponding_Formal_Spec (N))
3229 and then Etype (Nam) /= RTE (RE_AST_Handler)
3232 P : constant Entity_Id := Prefix (Nam);
3237 if Is_Tagged_Type (Etype (P)) then
3238 Ensure_Freeze_Node (Etype (P));
3239 Append_Freeze_Action (Etype (P), Body_Node);
3241 Rewrite (N, Body_Node);
3243 Set_Etype (New_S, Base_Type (Etype (New_S)));
3247 -- Generic formal subprograms or AST_Handler renaming
3250 Rewrite (N, Body_Node);
3252 Set_Etype (New_S, Base_Type (Etype (New_S)));
3255 if Is_Compilation_Unit (New_S) then
3257 ("a library unit can only rename another library unit", N);
3260 -- We suppress elaboration warnings for the resulting entity, since
3261 -- clearly they are not needed, and more particularly, in the case
3262 -- of a generic formal subprogram, the resulting entity can appear
3263 -- after the instantiation itself, and thus look like a bogus case
3264 -- of access before elaboration.
3266 Set_Suppress_Elaboration_Warnings (New_S);
3268 end Attribute_Renaming;
3270 ----------------------
3271 -- Chain_Use_Clause --
3272 ----------------------
3274 procedure Chain_Use_Clause (N : Node_Id) is
3276 Level : Int := Scope_Stack.Last;
3279 if not Is_Compilation_Unit (Current_Scope)
3280 or else not Is_Child_Unit (Current_Scope)
3282 null; -- Common case
3284 elsif Defining_Entity (Parent (N)) = Current_Scope then
3285 null; -- Common case for compilation unit
3288 -- If declaration appears in some other scope, it must be in some
3289 -- parent unit when compiling a child.
3291 Pack := Defining_Entity (Parent (N));
3292 if not In_Open_Scopes (Pack) then
3293 null; -- default as well
3296 -- Find entry for parent unit in scope stack
3298 while Scope_Stack.Table (Level).Entity /= Pack loop
3304 Set_Next_Use_Clause (N,
3305 Scope_Stack.Table (Level).First_Use_Clause);
3306 Scope_Stack.Table (Level).First_Use_Clause := N;
3307 end Chain_Use_Clause;
3309 ---------------------------
3310 -- Check_Frozen_Renaming --
3311 ---------------------------
3313 procedure Check_Frozen_Renaming (N : Node_Id; Subp : Entity_Id) is
3319 and then not Has_Completion (Subp)
3323 (Parent (Declaration_Node (Subp)), Defining_Entity (N));
3325 if Is_Entity_Name (Name (N)) then
3326 Old_S := Entity (Name (N));
3328 if not Is_Frozen (Old_S)
3329 and then Operating_Mode /= Check_Semantics
3331 Append_Freeze_Action (Old_S, B_Node);
3333 Insert_After (N, B_Node);
3337 if Is_Intrinsic_Subprogram (Old_S)
3338 and then not In_Instance
3341 ("subprogram used in renaming_as_body cannot be intrinsic",
3346 Insert_After (N, B_Node);
3350 end Check_Frozen_Renaming;
3352 -------------------------------
3353 -- Set_Entity_Or_Discriminal --
3354 -------------------------------
3356 procedure Set_Entity_Or_Discriminal (N : Node_Id; E : Entity_Id) is
3360 -- If the entity is not a discriminant, or else expansion is disabled,
3361 -- simply set the entity.
3363 if not In_Spec_Expression
3364 or else Ekind (E) /= E_Discriminant
3365 or else Inside_A_Generic
3367 Set_Entity_With_Style_Check (N, E);
3369 -- The replacement of a discriminant by the corresponding discriminal
3370 -- is not done for a task discriminant that appears in a default
3371 -- expression of an entry parameter. See Exp_Ch2.Expand_Discriminant
3372 -- for details on their handling.
3374 elsif Is_Concurrent_Type (Scope (E)) then
3378 and then not Nkind_In (P, N_Parameter_Specification,
3379 N_Component_Declaration)
3385 and then Nkind (P) = N_Parameter_Specification
3390 Set_Entity (N, Discriminal (E));
3393 -- Otherwise, this is a discriminant in a context in which
3394 -- it is a reference to the corresponding parameter of the
3395 -- init proc for the enclosing type.
3398 Set_Entity (N, Discriminal (E));
3400 end Set_Entity_Or_Discriminal;
3402 -----------------------------------
3403 -- Check_In_Previous_With_Clause --
3404 -----------------------------------
3406 procedure Check_In_Previous_With_Clause
3410 Pack : constant Entity_Id := Entity (Original_Node (Nam));
3415 Item := First (Context_Items (Parent (N)));
3417 while Present (Item)
3420 if Nkind (Item) = N_With_Clause
3422 -- Protect the frontend against previous critical errors
3424 and then Nkind (Name (Item)) /= N_Selected_Component
3425 and then Entity (Name (Item)) = Pack
3429 -- Find root library unit in with_clause
3431 while Nkind (Par) = N_Expanded_Name loop
3432 Par := Prefix (Par);
3435 if Is_Child_Unit (Entity (Original_Node (Par))) then
3436 Error_Msg_NE ("& is not directly visible", Par, Entity (Par));
3445 -- On exit, package is not mentioned in a previous with_clause.
3446 -- Check if its prefix is.
3448 if Nkind (Nam) = N_Expanded_Name then
3449 Check_In_Previous_With_Clause (N, Prefix (Nam));
3451 elsif Pack /= Any_Id then
3452 Error_Msg_NE ("& is not visible", Nam, Pack);
3454 end Check_In_Previous_With_Clause;
3456 ---------------------------------
3457 -- Check_Library_Unit_Renaming --
3458 ---------------------------------
3460 procedure Check_Library_Unit_Renaming (N : Node_Id; Old_E : Entity_Id) is
3464 if Nkind (Parent (N)) /= N_Compilation_Unit then
3467 -- Check for library unit. Note that we used to check for the scope
3468 -- being Standard here, but that was wrong for Standard itself.
3470 elsif not Is_Compilation_Unit (Old_E)
3471 and then not Is_Child_Unit (Old_E)
3473 Error_Msg_N ("renamed unit must be a library unit", Name (N));
3475 -- Entities defined in Standard (operators and boolean literals) cannot
3476 -- be renamed as library units.
3478 elsif Scope (Old_E) = Standard_Standard
3479 and then Sloc (Old_E) = Standard_Location
3481 Error_Msg_N ("renamed unit must be a library unit", Name (N));
3483 elsif Present (Parent_Spec (N))
3484 and then Nkind (Unit (Parent_Spec (N))) = N_Generic_Package_Declaration
3485 and then not Is_Child_Unit (Old_E)
3488 ("renamed unit must be a child unit of generic parent", Name (N));
3490 elsif Nkind (N) in N_Generic_Renaming_Declaration
3491 and then Nkind (Name (N)) = N_Expanded_Name
3492 and then Is_Generic_Instance (Entity (Prefix (Name (N))))
3493 and then Is_Generic_Unit (Old_E)
3496 ("renamed generic unit must be a library unit", Name (N));
3498 elsif Is_Package_Or_Generic_Package (Old_E) then
3500 -- Inherit categorization flags
3502 New_E := Defining_Entity (N);
3503 Set_Is_Pure (New_E, Is_Pure (Old_E));
3504 Set_Is_Preelaborated (New_E, Is_Preelaborated (Old_E));
3505 Set_Is_Remote_Call_Interface (New_E,
3506 Is_Remote_Call_Interface (Old_E));
3507 Set_Is_Remote_Types (New_E, Is_Remote_Types (Old_E));
3508 Set_Is_Shared_Passive (New_E, Is_Shared_Passive (Old_E));
3510 end Check_Library_Unit_Renaming;
3516 procedure End_Scope is
3522 Id := First_Entity (Current_Scope);
3523 while Present (Id) loop
3524 -- An entity in the current scope is not necessarily the first one
3525 -- on its homonym chain. Find its predecessor if any,
3526 -- If it is an internal entity, it will not be in the visibility
3527 -- chain altogether, and there is nothing to unchain.
3529 if Id /= Current_Entity (Id) then
3530 Prev := Current_Entity (Id);
3531 while Present (Prev)
3532 and then Present (Homonym (Prev))
3533 and then Homonym (Prev) /= Id
3535 Prev := Homonym (Prev);
3538 -- Skip to end of loop if Id is not in the visibility chain
3540 if No (Prev) or else Homonym (Prev) /= Id then
3548 Set_Is_Immediately_Visible (Id, False);
3550 Outer := Homonym (Id);
3551 while Present (Outer) and then Scope (Outer) = Current_Scope loop
3552 Outer := Homonym (Outer);
3555 -- Reset homonym link of other entities, but do not modify link
3556 -- between entities in current scope, so that the back-end can have
3557 -- a proper count of local overloadings.
3560 Set_Name_Entity_Id (Chars (Id), Outer);
3562 elsif Scope (Prev) /= Scope (Id) then
3563 Set_Homonym (Prev, Outer);
3570 -- If the scope generated freeze actions, place them before the
3571 -- current declaration and analyze them. Type declarations and
3572 -- the bodies of initialization procedures can generate such nodes.
3573 -- We follow the parent chain until we reach a list node, which is
3574 -- the enclosing list of declarations. If the list appears within
3575 -- a protected definition, move freeze nodes outside the protected
3579 (Scope_Stack.Table (Scope_Stack.Last).Pending_Freeze_Actions)
3583 L : constant List_Id := Scope_Stack.Table
3584 (Scope_Stack.Last).Pending_Freeze_Actions;
3587 if Is_Itype (Current_Scope) then
3588 Decl := Associated_Node_For_Itype (Current_Scope);
3590 Decl := Parent (Current_Scope);
3595 while not (Is_List_Member (Decl))
3596 or else Nkind_In (Parent (Decl), N_Protected_Definition,
3599 Decl := Parent (Decl);
3602 Insert_List_Before_And_Analyze (Decl, L);
3611 ---------------------
3612 -- End_Use_Clauses --
3613 ---------------------
3615 procedure End_Use_Clauses (Clause : Node_Id) is
3619 -- Remove Use_Type clauses first, because they affect the
3620 -- visibility of operators in subsequent used packages.
3623 while Present (U) loop
3624 if Nkind (U) = N_Use_Type_Clause then
3628 Next_Use_Clause (U);
3632 while Present (U) loop
3633 if Nkind (U) = N_Use_Package_Clause then
3634 End_Use_Package (U);
3637 Next_Use_Clause (U);
3639 end End_Use_Clauses;
3641 ---------------------
3642 -- End_Use_Package --
3643 ---------------------
3645 procedure End_Use_Package (N : Node_Id) is
3646 Pack_Name : Node_Id;
3651 function Is_Primitive_Operator_In_Use
3653 F : Entity_Id) return Boolean;
3654 -- Check whether Op is a primitive operator of a use-visible type
3656 ----------------------------------
3657 -- Is_Primitive_Operator_In_Use --
3658 ----------------------------------
3660 function Is_Primitive_Operator_In_Use
3662 F : Entity_Id) return Boolean
3664 T : constant Entity_Id := Base_Type (Etype (F));
3666 return In_Use (T) and then Scope (T) = Scope (Op);
3667 end Is_Primitive_Operator_In_Use;
3669 -- Start of processing for End_Use_Package
3672 Pack_Name := First (Names (N));
3673 while Present (Pack_Name) loop
3675 -- Test that Pack_Name actually denotes a package before processing
3677 if Is_Entity_Name (Pack_Name)
3678 and then Ekind (Entity (Pack_Name)) = E_Package
3680 Pack := Entity (Pack_Name);
3682 if In_Open_Scopes (Pack) then
3685 elsif not Redundant_Use (Pack_Name) then
3686 Set_In_Use (Pack, False);
3687 Set_Current_Use_Clause (Pack, Empty);
3689 Id := First_Entity (Pack);
3690 while Present (Id) loop
3692 -- Preserve use-visibility of operators that are primitive
3693 -- operators of a type that is use-visible through an active
3696 if Nkind (Id) = N_Defining_Operator_Symbol
3698 (Is_Primitive_Operator_In_Use
3699 (Id, First_Formal (Id))
3701 (Present (Next_Formal (First_Formal (Id)))
3703 Is_Primitive_Operator_In_Use
3704 (Id, Next_Formal (First_Formal (Id)))))
3709 Set_Is_Potentially_Use_Visible (Id, False);
3712 if Is_Private_Type (Id)
3713 and then Present (Full_View (Id))
3715 Set_Is_Potentially_Use_Visible (Full_View (Id), False);
3721 if Present (Renamed_Object (Pack)) then
3722 Set_In_Use (Renamed_Object (Pack), False);
3723 Set_Current_Use_Clause (Renamed_Object (Pack), Empty);
3726 if Chars (Pack) = Name_System
3727 and then Scope (Pack) = Standard_Standard
3728 and then Present_System_Aux
3730 Id := First_Entity (System_Aux_Id);
3731 while Present (Id) loop
3732 Set_Is_Potentially_Use_Visible (Id, False);
3734 if Is_Private_Type (Id)
3735 and then Present (Full_View (Id))
3737 Set_Is_Potentially_Use_Visible (Full_View (Id), False);
3743 Set_In_Use (System_Aux_Id, False);
3747 Set_Redundant_Use (Pack_Name, False);
3754 if Present (Hidden_By_Use_Clause (N)) then
3755 Elmt := First_Elmt (Hidden_By_Use_Clause (N));
3756 while Present (Elmt) loop
3758 E : constant Entity_Id := Node (Elmt);
3761 -- Reset either Use_Visibility or Direct_Visibility, depending
3762 -- on how the entity was hidden by the use clause.
3764 if In_Use (Scope (E))
3765 and then Used_As_Generic_Actual (Scope (E))
3767 Set_Is_Potentially_Use_Visible (Node (Elmt));
3769 Set_Is_Immediately_Visible (Node (Elmt));
3776 Set_Hidden_By_Use_Clause (N, No_Elist);
3778 end End_Use_Package;
3784 procedure End_Use_Type (N : Node_Id) is
3789 -- Start of processing for End_Use_Type
3792 Id := First (Subtype_Marks (N));
3793 while Present (Id) loop
3795 -- A call to Rtsfind may occur while analyzing a use_type clause,
3796 -- in which case the type marks are not resolved yet, and there is
3797 -- nothing to remove.
3799 if not Is_Entity_Name (Id) or else No (Entity (Id)) then
3805 if T = Any_Type or else From_With_Type (T) then
3808 -- Note that the use_type clause may mention a subtype of the type
3809 -- whose primitive operations have been made visible. Here as
3810 -- elsewhere, it is the base type that matters for visibility.
3812 elsif In_Open_Scopes (Scope (Base_Type (T))) then
3815 elsif not Redundant_Use (Id) then
3816 Set_In_Use (T, False);
3817 Set_In_Use (Base_Type (T), False);
3818 Set_Current_Use_Clause (T, Empty);
3819 Set_Current_Use_Clause (Base_Type (T), Empty);
3826 if Is_Empty_Elmt_List (Used_Operations (N)) then
3830 Elmt := First_Elmt (Used_Operations (N));
3831 while Present (Elmt) loop
3832 Set_Is_Potentially_Use_Visible (Node (Elmt), False);
3838 ----------------------
3839 -- Find_Direct_Name --
3840 ----------------------
3842 procedure Find_Direct_Name (N : Node_Id) is
3847 Inst : Entity_Id := Empty;
3848 -- Enclosing instance, if any
3850 Homonyms : Entity_Id;
3851 -- Saves start of homonym chain
3853 Nvis_Entity : Boolean;
3854 -- Set True to indicate that there is at least one entity on the homonym
3855 -- chain which, while not visible, is visible enough from the user point
3856 -- of view to warrant an error message of "not visible" rather than
3859 Nvis_Is_Private_Subprg : Boolean := False;
3860 -- Ada 2005 (AI-262): Set True to indicate that a form of Beaujolais
3861 -- effect concerning library subprograms has been detected. Used to
3862 -- generate the precise error message.
3864 function From_Actual_Package (E : Entity_Id) return Boolean;
3865 -- Returns true if the entity is declared in a package that is
3866 -- an actual for a formal package of the current instance. Such an
3867 -- entity requires special handling because it may be use-visible
3868 -- but hides directly visible entities defined outside the instance.
3870 function Is_Actual_Parameter return Boolean;
3871 -- This function checks if the node N is an identifier that is an actual
3872 -- parameter of a procedure call. If so it returns True, otherwise it
3873 -- return False. The reason for this check is that at this stage we do
3874 -- not know what procedure is being called if the procedure might be
3875 -- overloaded, so it is premature to go setting referenced flags or
3876 -- making calls to Generate_Reference. We will wait till Resolve_Actuals
3877 -- for that processing
3879 function Known_But_Invisible (E : Entity_Id) return Boolean;
3880 -- This function determines whether the entity E (which is not
3881 -- visible) can reasonably be considered to be known to the writer
3882 -- of the reference. This is a heuristic test, used only for the
3883 -- purposes of figuring out whether we prefer to complain that an
3884 -- entity is undefined or invisible (and identify the declaration
3885 -- of the invisible entity in the latter case). The point here is
3886 -- that we don't want to complain that something is invisible and
3887 -- then point to something entirely mysterious to the writer.
3889 procedure Nvis_Messages;
3890 -- Called if there are no visible entries for N, but there is at least
3891 -- one non-directly visible, or hidden declaration. This procedure
3892 -- outputs an appropriate set of error messages.
3894 procedure Undefined (Nvis : Boolean);
3895 -- This function is called if the current node has no corresponding
3896 -- visible entity or entities. The value set in Msg indicates whether
3897 -- an error message was generated (multiple error messages for the
3898 -- same variable are generally suppressed, see body for details).
3899 -- Msg is True if an error message was generated, False if not. This
3900 -- value is used by the caller to determine whether or not to output
3901 -- additional messages where appropriate. The parameter is set False
3902 -- to get the message "X is undefined", and True to get the message
3903 -- "X is not visible".
3905 -------------------------
3906 -- From_Actual_Package --
3907 -------------------------
3909 function From_Actual_Package (E : Entity_Id) return Boolean is
3910 Scop : constant Entity_Id := Scope (E);
3914 if not In_Instance then
3917 Inst := Current_Scope;
3918 while Present (Inst)
3919 and then Ekind (Inst) /= E_Package
3920 and then not Is_Generic_Instance (Inst)
3922 Inst := Scope (Inst);
3929 Act := First_Entity (Inst);
3930 while Present (Act) loop
3931 if Ekind (Act) = E_Package then
3933 -- Check for end of actuals list
3935 if Renamed_Object (Act) = Inst then
3938 elsif Present (Associated_Formal_Package (Act))
3939 and then Renamed_Object (Act) = Scop
3941 -- Entity comes from (instance of) formal package
3956 end From_Actual_Package;
3958 -------------------------
3959 -- Is_Actual_Parameter --
3960 -------------------------
3962 function Is_Actual_Parameter return Boolean is
3965 Nkind (N) = N_Identifier
3967 (Nkind (Parent (N)) = N_Procedure_Call_Statement
3969 (Nkind (Parent (N)) = N_Parameter_Association
3970 and then N = Explicit_Actual_Parameter (Parent (N))
3971 and then Nkind (Parent (Parent (N))) =
3972 N_Procedure_Call_Statement));
3973 end Is_Actual_Parameter;
3975 -------------------------
3976 -- Known_But_Invisible --
3977 -------------------------
3979 function Known_But_Invisible (E : Entity_Id) return Boolean is
3980 Fname : File_Name_Type;
3983 -- Entities in Standard are always considered to be known
3985 if Sloc (E) <= Standard_Location then
3988 -- An entity that does not come from source is always considered
3989 -- to be unknown, since it is an artifact of code expansion.
3991 elsif not Comes_From_Source (E) then
3994 -- In gnat internal mode, we consider all entities known
3996 elsif GNAT_Mode then
4000 -- Here we have an entity that is not from package Standard, and
4001 -- which comes from Source. See if it comes from an internal file.
4003 Fname := Unit_File_Name (Get_Source_Unit (E));
4005 -- Case of from internal file
4007 if Is_Internal_File_Name (Fname) then
4009 -- Private part entities in internal files are never considered
4010 -- to be known to the writer of normal application code.
4012 if Is_Hidden (E) then
4016 -- Entities from System packages other than System and
4017 -- System.Storage_Elements are not considered to be known.
4018 -- System.Auxxxx files are also considered known to the user.
4020 -- Should refine this at some point to generally distinguish
4021 -- between known and unknown internal files ???
4023 Get_Name_String (Fname);
4028 Name_Buffer (1 .. 2) /= "s-"
4030 Name_Buffer (3 .. 8) = "stoele"
4032 Name_Buffer (3 .. 5) = "aux";
4034 -- If not an internal file, then entity is definitely known,
4035 -- even if it is in a private part (the message generated will
4036 -- note that it is in a private part)
4041 end Known_But_Invisible;
4047 procedure Nvis_Messages is
4048 Comp_Unit : Node_Id;
4050 Found : Boolean := False;
4051 Hidden : Boolean := False;
4055 -- Ada 2005 (AI-262): Generate a precise error concerning the
4056 -- Beaujolais effect that was previously detected
4058 if Nvis_Is_Private_Subprg then
4060 pragma Assert (Nkind (E2) = N_Defining_Identifier
4061 and then Ekind (E2) = E_Function
4062 and then Scope (E2) = Standard_Standard
4063 and then Has_Private_With (E2));
4065 -- Find the sloc corresponding to the private with'ed unit
4067 Comp_Unit := Cunit (Current_Sem_Unit);
4068 Error_Msg_Sloc := No_Location;
4070 Item := First (Context_Items (Comp_Unit));
4071 while Present (Item) loop
4072 if Nkind (Item) = N_With_Clause
4073 and then Private_Present (Item)
4074 and then Entity (Name (Item)) = E2
4076 Error_Msg_Sloc := Sloc (Item);
4083 pragma Assert (Error_Msg_Sloc /= No_Location);
4085 Error_Msg_N ("(Ada 2005): hidden by private with clause #", N);
4089 Undefined (Nvis => True);
4093 -- First loop does hidden declarations
4096 while Present (Ent) loop
4097 if Is_Potentially_Use_Visible (Ent) then
4099 Error_Msg_N -- CODEFIX
4100 ("multiple use clauses cause hiding!", N);
4104 Error_Msg_Sloc := Sloc (Ent);
4105 Error_Msg_N -- CODEFIX
4106 ("hidden declaration#!", N);
4109 Ent := Homonym (Ent);
4112 -- If we found hidden declarations, then that's enough, don't
4113 -- bother looking for non-visible declarations as well.
4119 -- Second loop does non-directly visible declarations
4122 while Present (Ent) loop
4123 if not Is_Potentially_Use_Visible (Ent) then
4125 -- Do not bother the user with unknown entities
4127 if not Known_But_Invisible (Ent) then
4131 Error_Msg_Sloc := Sloc (Ent);
4133 -- Output message noting that there is a non-visible
4134 -- declaration, distinguishing the private part case.
4136 if Is_Hidden (Ent) then
4137 Error_Msg_N ("non-visible (private) declaration#!", N);
4139 -- If the entity is declared in a generic package, it
4140 -- cannot be visible, so there is no point in adding it
4141 -- to the list of candidates if another homograph from a
4142 -- non-generic package has been seen.
4144 elsif Ekind (Scope (Ent)) = E_Generic_Package
4150 Error_Msg_N -- CODEFIX
4151 ("non-visible declaration#!", N);
4153 if Ekind (Scope (Ent)) /= E_Generic_Package then
4157 if Is_Compilation_Unit (Ent)
4159 Nkind (Parent (Parent (N))) = N_Use_Package_Clause
4161 Error_Msg_Qual_Level := 99;
4162 Error_Msg_NE -- CODEFIX
4163 ("\\missing `WITH &;`", N, Ent);
4164 Error_Msg_Qual_Level := 0;
4167 if Ekind (Ent) = E_Discriminant
4168 and then Present (Corresponding_Discriminant (Ent))
4169 and then Scope (Corresponding_Discriminant (Ent)) =
4173 ("inherited discriminant not allowed here" &
4174 " (RM 3.8 (12), 3.8.1 (6))!", N);
4178 -- Set entity and its containing package as referenced. We
4179 -- can't be sure of this, but this seems a better choice
4180 -- to avoid unused entity messages.
4182 if Comes_From_Source (Ent) then
4183 Set_Referenced (Ent);
4184 Set_Referenced (Cunit_Entity (Get_Source_Unit (Ent)));
4189 Ent := Homonym (Ent);
4198 procedure Undefined (Nvis : Boolean) is
4199 Emsg : Error_Msg_Id;
4202 -- We should never find an undefined internal name. If we do, then
4203 -- see if we have previous errors. If so, ignore on the grounds that
4204 -- it is probably a cascaded message (e.g. a block label from a badly
4205 -- formed block). If no previous errors, then we have a real internal
4206 -- error of some kind so raise an exception.
4208 if Is_Internal_Name (Chars (N)) then
4209 if Total_Errors_Detected /= 0 then
4212 raise Program_Error;
4216 -- A very specialized error check, if the undefined variable is
4217 -- a case tag, and the case type is an enumeration type, check
4218 -- for a possible misspelling, and if so, modify the identifier
4220 -- Named aggregate should also be handled similarly ???
4222 if Nkind (N) = N_Identifier
4223 and then Nkind (Parent (N)) = N_Case_Statement_Alternative
4226 Case_Stm : constant Node_Id := Parent (Parent (N));
4227 Case_Typ : constant Entity_Id := Etype (Expression (Case_Stm));
4232 if Is_Enumeration_Type (Case_Typ)
4233 and then not Is_Standard_Character_Type (Case_Typ)
4235 Lit := First_Literal (Case_Typ);
4236 Get_Name_String (Chars (Lit));
4238 if Chars (Lit) /= Chars (N)
4239 and then Is_Bad_Spelling_Of (Chars (N), Chars (Lit)) then
4240 Error_Msg_Node_2 := Lit;
4241 Error_Msg_N -- CODEFIX
4242 ("& is undefined, assume misspelling of &", N);
4243 Rewrite (N, New_Occurrence_Of (Lit, Sloc (N)));
4247 Lit := Next_Literal (Lit);
4252 -- Normal processing
4254 Set_Entity (N, Any_Id);
4255 Set_Etype (N, Any_Type);
4257 -- We use the table Urefs to keep track of entities for which we
4258 -- have issued errors for undefined references. Multiple errors
4259 -- for a single name are normally suppressed, however we modify
4260 -- the error message to alert the programmer to this effect.
4262 for J in Urefs.First .. Urefs.Last loop
4263 if Chars (N) = Chars (Urefs.Table (J).Node) then
4264 if Urefs.Table (J).Err /= No_Error_Msg
4265 and then Sloc (N) /= Urefs.Table (J).Loc
4267 Error_Msg_Node_1 := Urefs.Table (J).Node;
4269 if Urefs.Table (J).Nvis then
4270 Change_Error_Text (Urefs.Table (J).Err,
4271 "& is not visible (more references follow)");
4273 Change_Error_Text (Urefs.Table (J).Err,
4274 "& is undefined (more references follow)");
4277 Urefs.Table (J).Err := No_Error_Msg;
4280 -- Although we will set Msg False, and thus suppress the
4281 -- message, we also set Error_Posted True, to avoid any
4282 -- cascaded messages resulting from the undefined reference.
4285 Set_Error_Posted (N, True);
4290 -- If entry not found, this is first undefined occurrence
4293 Error_Msg_N ("& is not visible!", N);
4297 Error_Msg_N ("& is undefined!", N);
4300 -- A very bizarre special check, if the undefined identifier
4301 -- is put or put_line, then add a special error message (since
4302 -- this is a very common error for beginners to make).
4304 if Chars (N) = Name_Put or else Chars (N) = Name_Put_Line then
4305 Error_Msg_N -- CODEFIX
4306 ("\\possible missing `WITH Ada.Text_'I'O; " &
4307 "USE Ada.Text_'I'O`!", N);
4309 -- Another special check if N is the prefix of a selected
4310 -- component which is a known unit, add message complaining
4311 -- about missing with for this unit.
4313 elsif Nkind (Parent (N)) = N_Selected_Component
4314 and then N = Prefix (Parent (N))
4315 and then Is_Known_Unit (Parent (N))
4317 Error_Msg_Node_2 := Selector_Name (Parent (N));
4318 Error_Msg_N -- CODEFIX
4319 ("\\missing `WITH &.&;`", Prefix (Parent (N)));
4322 -- Now check for possible misspellings
4326 Ematch : Entity_Id := Empty;
4328 Last_Name_Id : constant Name_Id :=
4329 Name_Id (Nat (First_Name_Id) +
4330 Name_Entries_Count - 1);
4333 for Nam in First_Name_Id .. Last_Name_Id loop
4334 E := Get_Name_Entity_Id (Nam);
4337 and then (Is_Immediately_Visible (E)
4339 Is_Potentially_Use_Visible (E))
4341 if Is_Bad_Spelling_Of (Chars (N), Nam) then
4348 if Present (Ematch) then
4349 Error_Msg_NE -- CODEFIX
4350 ("\possible misspelling of&", N, Ematch);
4355 -- Make entry in undefined references table unless the full errors
4356 -- switch is set, in which case by refraining from generating the
4357 -- table entry, we guarantee that we get an error message for every
4358 -- undefined reference.
4360 if not All_Errors_Mode then
4371 -- Start of processing for Find_Direct_Name
4374 -- If the entity pointer is already set, this is an internal node, or
4375 -- a node that is analyzed more than once, after a tree modification.
4376 -- In such a case there is no resolution to perform, just set the type.
4378 if Present (Entity (N)) then
4379 if Is_Type (Entity (N)) then
4380 Set_Etype (N, Entity (N));
4384 Entyp : constant Entity_Id := Etype (Entity (N));
4387 -- One special case here. If the Etype field is already set,
4388 -- and references the packed array type corresponding to the
4389 -- etype of the referenced entity, then leave it alone. This
4390 -- happens for trees generated from Exp_Pakd, where expressions
4391 -- can be deliberately "mis-typed" to the packed array type.
4393 if Is_Array_Type (Entyp)
4394 and then Is_Packed (Entyp)
4395 and then Present (Etype (N))
4396 and then Etype (N) = Packed_Array_Type (Entyp)
4400 -- If not that special case, then just reset the Etype
4403 Set_Etype (N, Etype (Entity (N)));
4411 -- Here if Entity pointer was not set, we need full visibility analysis
4412 -- First we generate debugging output if the debug E flag is set.
4414 if Debug_Flag_E then
4415 Write_Str ("Looking for ");
4416 Write_Name (Chars (N));
4420 Homonyms := Current_Entity (N);
4421 Nvis_Entity := False;
4424 while Present (E) loop
4426 -- If entity is immediately visible or potentially use visible, then
4427 -- process the entity and we are done.
4429 if Is_Immediately_Visible (E) then
4430 goto Immediately_Visible_Entity;
4432 elsif Is_Potentially_Use_Visible (E) then
4433 goto Potentially_Use_Visible_Entity;
4435 -- Note if a known but invisible entity encountered
4437 elsif Known_But_Invisible (E) then
4438 Nvis_Entity := True;
4441 -- Move to next entity in chain and continue search
4446 -- If no entries on homonym chain that were potentially visible,
4447 -- and no entities reasonably considered as non-visible, then
4448 -- we have a plain undefined reference, with no additional
4449 -- explanation required!
4451 if not Nvis_Entity then
4452 Undefined (Nvis => False);
4454 -- Otherwise there is at least one entry on the homonym chain that
4455 -- is reasonably considered as being known and non-visible.
4463 -- Processing for a potentially use visible entry found. We must search
4464 -- the rest of the homonym chain for two reasons. First, if there is a
4465 -- directly visible entry, then none of the potentially use-visible
4466 -- entities are directly visible (RM 8.4(10)). Second, we need to check
4467 -- for the case of multiple potentially use-visible entries hiding one
4468 -- another and as a result being non-directly visible (RM 8.4(11)).
4470 <<Potentially_Use_Visible_Entity>> declare
4471 Only_One_Visible : Boolean := True;
4472 All_Overloadable : Boolean := Is_Overloadable (E);
4476 while Present (E2) loop
4477 if Is_Immediately_Visible (E2) then
4479 -- If the use-visible entity comes from the actual for a
4480 -- formal package, it hides a directly visible entity from
4481 -- outside the instance.
4483 if From_Actual_Package (E)
4484 and then Scope_Depth (E2) < Scope_Depth (Inst)
4489 goto Immediately_Visible_Entity;
4492 elsif Is_Potentially_Use_Visible (E2) then
4493 Only_One_Visible := False;
4494 All_Overloadable := All_Overloadable and Is_Overloadable (E2);
4496 -- Ada 2005 (AI-262): Protect against a form of Beaujolais effect
4497 -- that can occur in private_with clauses. Example:
4500 -- private with B; package A is
4501 -- package C is function B return Integer;
4503 -- V1 : Integer := B;
4504 -- private function B return Integer;
4505 -- V2 : Integer := B;
4508 -- V1 resolves to A.B, but V2 resolves to library unit B
4510 elsif Ekind (E2) = E_Function
4511 and then Scope (E2) = Standard_Standard
4512 and then Has_Private_With (E2)
4514 Only_One_Visible := False;
4515 All_Overloadable := False;
4516 Nvis_Is_Private_Subprg := True;
4523 -- On falling through this loop, we have checked that there are no
4524 -- immediately visible entities. Only_One_Visible is set if exactly
4525 -- one potentially use visible entity exists. All_Overloadable is
4526 -- set if all the potentially use visible entities are overloadable.
4527 -- The condition for legality is that either there is one potentially
4528 -- use visible entity, or if there is more than one, then all of them
4529 -- are overloadable.
4531 if Only_One_Visible or All_Overloadable then
4534 -- If there is more than one potentially use-visible entity and at
4535 -- least one of them non-overloadable, we have an error (RM 8.4(11).
4536 -- Note that E points to the first such entity on the homonym list.
4537 -- Special case: if one of the entities is declared in an actual
4538 -- package, it was visible in the generic, and takes precedence over
4539 -- other entities that are potentially use-visible. Same if it is
4540 -- declared in a local instantiation of the current instance.
4545 -- Find current instance
4547 Inst := Current_Scope;
4548 while Present (Inst)
4549 and then Inst /= Standard_Standard
4551 if Is_Generic_Instance (Inst) then
4555 Inst := Scope (Inst);
4559 while Present (E2) loop
4560 if From_Actual_Package (E2)
4562 (Is_Generic_Instance (Scope (E2))
4563 and then Scope_Depth (Scope (E2)) > Scope_Depth (Inst))
4576 Is_Predefined_File_Name (Unit_File_Name (Current_Sem_Unit))
4578 -- A use-clause in the body of a system file creates conflict
4579 -- with some entity in a user scope, while rtsfind is active.
4580 -- Keep only the entity coming from another predefined unit.
4583 while Present (E2) loop
4584 if Is_Predefined_File_Name
4585 (Unit_File_Name (Get_Source_Unit (Sloc (E2))))
4594 -- Entity must exist because predefined unit is correct
4596 raise Program_Error;
4605 -- Come here with E set to the first immediately visible entity on
4606 -- the homonym chain. This is the one we want unless there is another
4607 -- immediately visible entity further on in the chain for an inner
4608 -- scope (RM 8.3(8)).
4610 <<Immediately_Visible_Entity>> declare
4615 -- Find scope level of initial entity. When compiling through
4616 -- Rtsfind, the previous context is not completely invisible, and
4617 -- an outer entity may appear on the chain, whose scope is below
4618 -- the entry for Standard that delimits the current scope stack.
4619 -- Indicate that the level for this spurious entry is outside of
4620 -- the current scope stack.
4622 Level := Scope_Stack.Last;
4624 Scop := Scope_Stack.Table (Level).Entity;
4625 exit when Scop = Scope (E);
4627 exit when Scop = Standard_Standard;
4630 -- Now search remainder of homonym chain for more inner entry
4631 -- If the entity is Standard itself, it has no scope, and we
4632 -- compare it with the stack entry directly.
4635 while Present (E2) loop
4636 if Is_Immediately_Visible (E2) then
4638 -- If a generic package contains a local declaration that
4639 -- has the same name as the generic, there may be a visibility
4640 -- conflict in an instance, where the local declaration must
4641 -- also hide the name of the corresponding package renaming.
4642 -- We check explicitly for a package declared by a renaming,
4643 -- whose renamed entity is an instance that is on the scope
4644 -- stack, and that contains a homonym in the same scope. Once
4645 -- we have found it, we know that the package renaming is not
4646 -- immediately visible, and that the identifier denotes the
4647 -- other entity (and its homonyms if overloaded).
4649 if Scope (E) = Scope (E2)
4650 and then Ekind (E) = E_Package
4651 and then Present (Renamed_Object (E))
4652 and then Is_Generic_Instance (Renamed_Object (E))
4653 and then In_Open_Scopes (Renamed_Object (E))
4654 and then Comes_From_Source (N)
4656 Set_Is_Immediately_Visible (E, False);
4660 for J in Level + 1 .. Scope_Stack.Last loop
4661 if Scope_Stack.Table (J).Entity = Scope (E2)
4662 or else Scope_Stack.Table (J).Entity = E2
4675 -- At the end of that loop, E is the innermost immediately
4676 -- visible entity, so we are all set.
4679 -- Come here with entity found, and stored in E
4683 -- Check violation of No_Wide_Characters restriction
4685 Check_Wide_Character_Restriction (E, N);
4687 -- When distribution features are available (Get_PCS_Name /=
4688 -- Name_No_DSA), a remote access-to-subprogram type is converted
4689 -- into a record type holding whatever information is needed to
4690 -- perform a remote call on an RCI subprogram. In that case we
4691 -- rewrite any occurrence of the RAS type into the equivalent record
4692 -- type here. 'Access attribute references and RAS dereferences are
4693 -- then implemented using specific TSSs. However when distribution is
4694 -- not available (case of Get_PCS_Name = Name_No_DSA), we bypass the
4695 -- generation of these TSSs, and we must keep the RAS type in its
4696 -- original access-to-subprogram form (since all calls through a
4697 -- value of such type will be local anyway in the absence of a PCS).
4699 if Comes_From_Source (N)
4700 and then Is_Remote_Access_To_Subprogram_Type (E)
4701 and then Expander_Active
4702 and then Get_PCS_Name /= Name_No_DSA
4705 New_Occurrence_Of (Equivalent_Type (E), Sloc (N)));
4709 -- Set the entity. Note that the reason we call Set_Entity for the
4710 -- overloadable case, as opposed to Set_Entity_With_Style_Check is
4711 -- that in the overloaded case, the initial call can set the wrong
4712 -- homonym. The call that sets the right homonym is in Sem_Res and
4713 -- that call does use Set_Entity_With_Style_Check, so we don't miss
4716 if Is_Overloadable (E) then
4719 Set_Entity_With_Style_Check (N, E);
4725 Set_Etype (N, Get_Full_View (Etype (E)));
4728 if Debug_Flag_E then
4729 Write_Str (" found ");
4730 Write_Entity_Info (E, " ");
4733 -- If the Ekind of the entity is Void, it means that all homonyms
4734 -- are hidden from all visibility (RM 8.3(5,14-20)). However, this
4735 -- test is skipped if the current scope is a record and the name is
4736 -- a pragma argument expression (case of Atomic and Volatile pragmas
4737 -- and possibly other similar pragmas added later, which are allowed
4738 -- to reference components in the current record).
4740 if Ekind (E) = E_Void
4742 (not Is_Record_Type (Current_Scope)
4743 or else Nkind (Parent (N)) /= N_Pragma_Argument_Association)
4745 Premature_Usage (N);
4747 -- If the entity is overloadable, collect all interpretations of the
4748 -- name for subsequent overload resolution. We optimize a bit here to
4749 -- do this only if we have an overloadable entity that is not on its
4750 -- own on the homonym chain.
4752 elsif Is_Overloadable (E)
4753 and then (Present (Homonym (E)) or else Current_Entity (N) /= E)
4755 Collect_Interps (N);
4757 -- If no homonyms were visible, the entity is unambiguous
4759 if not Is_Overloaded (N) then
4760 if not Is_Actual_Parameter then
4761 Generate_Reference (E, N);
4765 -- Case of non-overloadable entity, set the entity providing that
4766 -- we do not have the case of a discriminant reference within a
4767 -- default expression. Such references are replaced with the
4768 -- corresponding discriminal, which is the formal corresponding to
4769 -- to the discriminant in the initialization procedure.
4772 -- Entity is unambiguous, indicate that it is referenced here
4774 -- For a renaming of an object, always generate simple reference,
4775 -- we don't try to keep track of assignments in this case.
4777 if Is_Object (E) and then Present (Renamed_Object (E)) then
4778 Generate_Reference (E, N);
4780 -- If the renamed entity is a private protected component,
4781 -- reference the original component as well. This needs to be
4782 -- done because the private renamings are installed before any
4783 -- analysis has occurred. Reference to a private component will
4784 -- resolve to the renaming and the original component will be
4785 -- left unreferenced, hence the following.
4787 if Is_Prival (E) then
4788 Generate_Reference (Prival_Link (E), N);
4791 -- One odd case is that we do not want to set the Referenced flag
4792 -- if the entity is a label, and the identifier is the label in
4793 -- the source, since this is not a reference from the point of
4794 -- view of the user.
4796 elsif Nkind (Parent (N)) = N_Label then
4798 R : constant Boolean := Referenced (E);
4801 -- Generate reference unless this is an actual parameter
4802 -- (see comment below)
4804 if Is_Actual_Parameter then
4805 Generate_Reference (E, N);
4806 Set_Referenced (E, R);
4810 -- Normal case, not a label: generate reference
4812 -- ??? It is too early to generate a reference here even if the
4813 -- entity is unambiguous, because the tree is not sufficiently
4814 -- typed at this point for Generate_Reference to determine
4815 -- whether this reference modifies the denoted object (because
4816 -- implicit dereferences cannot be identified prior to full type
4819 -- The Is_Actual_Parameter routine takes care of one of these
4820 -- cases but there are others probably ???
4822 -- If the entity is the LHS of an assignment, and is a variable
4823 -- (rather than a package prefix), we can mark it as a
4824 -- modification right away, to avoid duplicate references.
4827 if not Is_Actual_Parameter then
4829 and then Ekind (E) /= E_Package
4830 and then Ekind (E) /= E_Generic_Package
4832 Generate_Reference (E, N, 'm');
4834 Generate_Reference (E, N);
4838 Check_Nested_Access (E);
4841 Set_Entity_Or_Discriminal (N, E);
4843 if Ada_Version >= Ada_2012
4845 (Nkind (Parent (N)) in N_Subexpr
4846 or else Nkind (Parent (N)) = N_Object_Declaration)
4848 Check_Implicit_Dereference (N, Etype (E));
4852 end Find_Direct_Name;
4854 ------------------------
4855 -- Find_Expanded_Name --
4856 ------------------------
4858 -- This routine searches the homonym chain of the entity until it finds
4859 -- an entity declared in the scope denoted by the prefix. If the entity
4860 -- is private, it may nevertheless be immediately visible, if we are in
4861 -- the scope of its declaration.
4863 procedure Find_Expanded_Name (N : Node_Id) is
4864 Selector : constant Node_Id := Selector_Name (N);
4865 Candidate : Entity_Id := Empty;
4871 P_Name := Entity (Prefix (N));
4874 -- If the prefix is a renamed package, look for the entity in the
4875 -- original package.
4877 if Ekind (P_Name) = E_Package
4878 and then Present (Renamed_Object (P_Name))
4880 P_Name := Renamed_Object (P_Name);
4882 -- Rewrite node with entity field pointing to renamed object
4884 Rewrite (Prefix (N), New_Copy (Prefix (N)));
4885 Set_Entity (Prefix (N), P_Name);
4887 -- If the prefix is an object of a concurrent type, look for
4888 -- the entity in the associated task or protected type.
4890 elsif Is_Concurrent_Type (Etype (P_Name)) then
4891 P_Name := Etype (P_Name);
4894 Id := Current_Entity (Selector);
4897 Is_New_Candidate : Boolean;
4900 while Present (Id) loop
4901 if Scope (Id) = P_Name then
4903 Is_New_Candidate := True;
4905 -- Ada 2005 (AI-217): Handle shadow entities associated with types
4906 -- declared in limited-withed nested packages. We don't need to
4907 -- handle E_Incomplete_Subtype entities because the entities in
4908 -- the limited view are always E_Incomplete_Type entities (see
4909 -- Build_Limited_Views). Regarding the expression used to evaluate
4910 -- the scope, it is important to note that the limited view also
4911 -- has shadow entities associated nested packages. For this reason
4912 -- the correct scope of the entity is the scope of the real entity
4913 -- The non-limited view may itself be incomplete, in which case
4914 -- get the full view if available.
4916 elsif From_With_Type (Id)
4917 and then Is_Type (Id)
4918 and then Ekind (Id) = E_Incomplete_Type
4919 and then Present (Non_Limited_View (Id))
4920 and then Scope (Non_Limited_View (Id)) = P_Name
4922 Candidate := Get_Full_View (Non_Limited_View (Id));
4923 Is_New_Candidate := True;
4926 Is_New_Candidate := False;
4929 if Is_New_Candidate then
4930 if Is_Child_Unit (Id) then
4931 exit when Is_Visible_Child_Unit (Id)
4932 or else Is_Immediately_Visible (Id);
4935 exit when not Is_Hidden (Id)
4936 or else Is_Immediately_Visible (Id);
4945 and then (Ekind (P_Name) = E_Procedure
4947 Ekind (P_Name) = E_Function)
4948 and then Is_Generic_Instance (P_Name)
4950 -- Expanded name denotes entity in (instance of) generic subprogram.
4951 -- The entity may be in the subprogram instance, or may denote one of
4952 -- the formals, which is declared in the enclosing wrapper package.
4954 P_Name := Scope (P_Name);
4956 Id := Current_Entity (Selector);
4957 while Present (Id) loop
4958 exit when Scope (Id) = P_Name;
4963 if No (Id) or else Chars (Id) /= Chars (Selector) then
4964 Set_Etype (N, Any_Type);
4966 -- If we are looking for an entity defined in System, try to find it
4967 -- in the child package that may have been provided as an extension
4968 -- to System. The Extend_System pragma will have supplied the name of
4969 -- the extension, which may have to be loaded.
4971 if Chars (P_Name) = Name_System
4972 and then Scope (P_Name) = Standard_Standard
4973 and then Present (System_Extend_Unit)
4974 and then Present_System_Aux (N)
4976 Set_Entity (Prefix (N), System_Aux_Id);
4977 Find_Expanded_Name (N);
4980 elsif Nkind (Selector) = N_Operator_Symbol
4981 and then Has_Implicit_Operator (N)
4983 -- There is an implicit instance of the predefined operator in
4984 -- the given scope. The operator entity is defined in Standard.
4985 -- Has_Implicit_Operator makes the node into an Expanded_Name.
4989 elsif Nkind (Selector) = N_Character_Literal
4990 and then Has_Implicit_Character_Literal (N)
4992 -- If there is no literal defined in the scope denoted by the
4993 -- prefix, the literal may belong to (a type derived from)
4994 -- Standard_Character, for which we have no explicit literals.
4999 -- If the prefix is a single concurrent object, use its name in
5000 -- the error message, rather than that of the anonymous type.
5002 if Is_Concurrent_Type (P_Name)
5003 and then Is_Internal_Name (Chars (P_Name))
5005 Error_Msg_Node_2 := Entity (Prefix (N));
5007 Error_Msg_Node_2 := P_Name;
5010 if P_Name = System_Aux_Id then
5011 P_Name := Scope (P_Name);
5012 Set_Entity (Prefix (N), P_Name);
5015 if Present (Candidate) then
5017 -- If we know that the unit is a child unit we can give a more
5018 -- accurate error message.
5020 if Is_Child_Unit (Candidate) then
5022 -- If the candidate is a private child unit and we are in
5023 -- the visible part of a public unit, specialize the error
5024 -- message. There might be a private with_clause for it,
5025 -- but it is not currently active.
5027 if Is_Private_Descendant (Candidate)
5028 and then Ekind (Current_Scope) = E_Package
5029 and then not In_Private_Part (Current_Scope)
5030 and then not Is_Private_Descendant (Current_Scope)
5032 Error_Msg_N ("private child unit& is not visible here",
5035 -- Normal case where we have a missing with for a child unit
5038 Error_Msg_Qual_Level := 99;
5039 Error_Msg_NE -- CODEFIX
5040 ("missing `WITH &;`", Selector, Candidate);
5041 Error_Msg_Qual_Level := 0;
5044 -- Here we don't know that this is a child unit
5047 Error_Msg_NE ("& is not a visible entity of&", N, Selector);
5051 -- Within the instantiation of a child unit, the prefix may
5052 -- denote the parent instance, but the selector has the name
5053 -- of the original child. Find whether we are within the
5054 -- corresponding instance, and get the proper entity, which
5055 -- can only be an enclosing scope.
5058 and then In_Open_Scopes (P_Name)
5059 and then Is_Generic_Instance (P_Name)
5062 S : Entity_Id := Current_Scope;
5066 for J in reverse 0 .. Scope_Stack.Last loop
5067 S := Scope_Stack.Table (J).Entity;
5069 exit when S = Standard_Standard;
5071 if Ekind_In (S, E_Function,
5075 P := Generic_Parent (Specification
5076 (Unit_Declaration_Node (S)));
5079 and then Chars (Scope (P)) = Chars (O_Name)
5080 and then Chars (P) = Chars (Selector)
5091 -- If this is a selection from Ada, System or Interfaces, then
5092 -- we assume a missing with for the corresponding package.
5094 if Is_Known_Unit (N) then
5095 if not Error_Posted (N) then
5096 Error_Msg_Node_2 := Selector;
5097 Error_Msg_N -- CODEFIX
5098 ("missing `WITH &.&;`", Prefix (N));
5101 -- If this is a selection from a dummy package, then suppress
5102 -- the error message, of course the entity is missing if the
5103 -- package is missing!
5105 elsif Sloc (Error_Msg_Node_2) = No_Location then
5108 -- Here we have the case of an undefined component
5112 -- The prefix may hide a homonym in the context that
5113 -- declares the desired entity. This error can use a
5114 -- specialized message.
5116 if In_Open_Scopes (P_Name)
5117 and then Present (Homonym (P_Name))
5118 and then Is_Compilation_Unit (Homonym (P_Name))
5120 (Is_Immediately_Visible (Homonym (P_Name))
5121 or else Is_Visible_Child_Unit (Homonym (P_Name)))
5124 H : constant Entity_Id := Homonym (P_Name);
5127 Id := First_Entity (H);
5128 while Present (Id) loop
5129 if Chars (Id) = Chars (Selector) then
5130 Error_Msg_Qual_Level := 99;
5131 Error_Msg_Name_1 := Chars (Selector);
5133 ("% not declared in&", N, P_Name);
5135 ("\use fully qualified name starting with"
5136 & " Standard to make& visible", N, H);
5137 Error_Msg_Qual_Level := 0;
5144 -- If not found, standard error message
5146 Error_Msg_NE ("& not declared in&", N, Selector);
5152 Error_Msg_NE ("& not declared in&", N, Selector);
5155 -- Check for misspelling of some entity in prefix
5157 Id := First_Entity (P_Name);
5158 while Present (Id) loop
5159 if Is_Bad_Spelling_Of (Chars (Id), Chars (Selector))
5160 and then not Is_Internal_Name (Chars (Id))
5162 Error_Msg_NE -- CODEFIX
5163 ("possible misspelling of&", Selector, Id);
5170 -- Specialize the message if this may be an instantiation
5171 -- of a child unit that was not mentioned in the context.
5173 if Nkind (Parent (N)) = N_Package_Instantiation
5174 and then Is_Generic_Instance (Entity (Prefix (N)))
5175 and then Is_Compilation_Unit
5176 (Generic_Parent (Parent (Entity (Prefix (N)))))
5178 Error_Msg_Node_2 := Selector;
5179 Error_Msg_N -- CODEFIX
5180 ("\missing `WITH &.&;`", Prefix (N));
5190 if Comes_From_Source (N)
5191 and then Is_Remote_Access_To_Subprogram_Type (Id)
5192 and then Present (Equivalent_Type (Id))
5194 -- If we are not actually generating distribution code (i.e. the
5195 -- current PCS is the dummy non-distributed version), then the
5196 -- Equivalent_Type will be missing, and Id should be treated as
5197 -- a regular access-to-subprogram type.
5199 Id := Equivalent_Type (Id);
5200 Set_Chars (Selector, Chars (Id));
5203 -- Ada 2005 (AI-50217): Check usage of entities in limited withed units
5205 if Ekind (P_Name) = E_Package
5206 and then From_With_Type (P_Name)
5208 if From_With_Type (Id)
5209 or else Is_Type (Id)
5210 or else Ekind (Id) = E_Package
5215 ("limited withed package can only be used to access "
5216 & "incomplete types",
5221 if Is_Task_Type (P_Name)
5222 and then ((Ekind (Id) = E_Entry
5223 and then Nkind (Parent (N)) /= N_Attribute_Reference)
5225 (Ekind (Id) = E_Entry_Family
5227 Nkind (Parent (Parent (N))) /= N_Attribute_Reference))
5229 -- It is an entry call after all, either to the current task (which
5230 -- will deadlock) or to an enclosing task.
5232 Analyze_Selected_Component (N);
5236 Change_Selected_Component_To_Expanded_Name (N);
5238 -- Do style check and generate reference, but skip both steps if this
5239 -- entity has homonyms, since we may not have the right homonym set yet.
5240 -- The proper homonym will be set during the resolve phase.
5242 if Has_Homonym (Id) then
5245 Set_Entity_Or_Discriminal (N, Id);
5248 Generate_Reference (Id, N, 'm');
5250 Generate_Reference (Id, N);
5254 if Is_Type (Id) then
5257 Set_Etype (N, Get_Full_View (Etype (Id)));
5260 -- Check for violation of No_Wide_Characters
5262 Check_Wide_Character_Restriction (Id, N);
5264 -- If the Ekind of the entity is Void, it means that all homonyms are
5265 -- hidden from all visibility (RM 8.3(5,14-20)).
5267 if Ekind (Id) = E_Void then
5268 Premature_Usage (N);
5270 elsif Is_Overloadable (Id)
5271 and then Present (Homonym (Id))
5274 H : Entity_Id := Homonym (Id);
5277 while Present (H) loop
5278 if Scope (H) = Scope (Id)
5281 or else Is_Immediately_Visible (H))
5283 Collect_Interps (N);
5290 -- If an extension of System is present, collect possible explicit
5291 -- overloadings declared in the extension.
5293 if Chars (P_Name) = Name_System
5294 and then Scope (P_Name) = Standard_Standard
5295 and then Present (System_Extend_Unit)
5296 and then Present_System_Aux (N)
5298 H := Current_Entity (Id);
5300 while Present (H) loop
5301 if Scope (H) = System_Aux_Id then
5302 Add_One_Interp (N, H, Etype (H));
5311 if Nkind (Selector_Name (N)) = N_Operator_Symbol
5312 and then Scope (Id) /= Standard_Standard
5314 -- In addition to user-defined operators in the given scope, there
5315 -- may be an implicit instance of the predefined operator. The
5316 -- operator (defined in Standard) is found in Has_Implicit_Operator,
5317 -- and added to the interpretations. Procedure Add_One_Interp will
5318 -- determine which hides which.
5320 if Has_Implicit_Operator (N) then
5324 end Find_Expanded_Name;
5326 -------------------------
5327 -- Find_Renamed_Entity --
5328 -------------------------
5330 function Find_Renamed_Entity
5334 Is_Actual : Boolean := False) return Entity_Id
5337 I1 : Interp_Index := 0; -- Suppress junk warnings
5343 function Enclosing_Instance return Entity_Id;
5344 -- If the renaming determines the entity for the default of a formal
5345 -- subprogram nested within another instance, choose the innermost
5346 -- candidate. This is because if the formal has a box, and we are within
5347 -- an enclosing instance where some candidate interpretations are local
5348 -- to this enclosing instance, we know that the default was properly
5349 -- resolved when analyzing the generic, so we prefer the local
5350 -- candidates to those that are external. This is not always the case
5351 -- but is a reasonable heuristic on the use of nested generics. The
5352 -- proper solution requires a full renaming model.
5354 function Is_Visible_Operation (Op : Entity_Id) return Boolean;
5355 -- If the renamed entity is an implicit operator, check whether it is
5356 -- visible because its operand type is properly visible. This check
5357 -- applies to explicit renamed entities that appear in the source in a
5358 -- renaming declaration or a formal subprogram instance, but not to
5359 -- default generic actuals with a name.
5361 function Report_Overload return Entity_Id;
5362 -- List possible interpretations, and specialize message in the
5363 -- case of a generic actual.
5365 function Within (Inner, Outer : Entity_Id) return Boolean;
5366 -- Determine whether a candidate subprogram is defined within the
5367 -- enclosing instance. If yes, it has precedence over outer candidates.
5369 ------------------------
5370 -- Enclosing_Instance --
5371 ------------------------
5373 function Enclosing_Instance return Entity_Id is
5377 if not Is_Generic_Instance (Current_Scope)
5378 and then not Is_Actual
5383 S := Scope (Current_Scope);
5384 while S /= Standard_Standard loop
5385 if Is_Generic_Instance (S) then
5393 end Enclosing_Instance;
5395 --------------------------
5396 -- Is_Visible_Operation --
5397 --------------------------
5399 function Is_Visible_Operation (Op : Entity_Id) return Boolean is
5405 if Ekind (Op) /= E_Operator
5406 or else Scope (Op) /= Standard_Standard
5407 or else (In_Instance
5410 or else Present (Enclosing_Instance)))
5415 -- For a fixed point type operator, check the resulting type,
5416 -- because it may be a mixed mode integer * fixed operation.
5418 if Present (Next_Formal (First_Formal (New_S)))
5419 and then Is_Fixed_Point_Type (Etype (New_S))
5421 Typ := Etype (New_S);
5423 Typ := Etype (First_Formal (New_S));
5426 Btyp := Base_Type (Typ);
5428 if Nkind (Nam) /= N_Expanded_Name then
5429 return (In_Open_Scopes (Scope (Btyp))
5430 or else Is_Potentially_Use_Visible (Btyp)
5431 or else In_Use (Btyp)
5432 or else In_Use (Scope (Btyp)));
5435 Scop := Entity (Prefix (Nam));
5437 if Ekind (Scop) = E_Package
5438 and then Present (Renamed_Object (Scop))
5440 Scop := Renamed_Object (Scop);
5443 -- Operator is visible if prefix of expanded name denotes
5444 -- scope of type, or else type is defined in System_Aux
5445 -- and the prefix denotes System.
5447 return Scope (Btyp) = Scop
5448 or else (Scope (Btyp) = System_Aux_Id
5449 and then Scope (Scope (Btyp)) = Scop);
5452 end Is_Visible_Operation;
5458 function Within (Inner, Outer : Entity_Id) return Boolean is
5462 Sc := Scope (Inner);
5463 while Sc /= Standard_Standard loop
5474 ---------------------
5475 -- Report_Overload --
5476 ---------------------
5478 function Report_Overload return Entity_Id is
5481 Error_Msg_NE -- CODEFIX
5482 ("ambiguous actual subprogram&, " &
5483 "possible interpretations:", N, Nam);
5485 Error_Msg_N -- CODEFIX
5486 ("ambiguous subprogram, " &
5487 "possible interpretations:", N);
5490 List_Interps (Nam, N);
5492 end Report_Overload;
5494 -- Start of processing for Find_Renamed_Entity
5498 Candidate_Renaming := Empty;
5500 if not Is_Overloaded (Nam) then
5501 if Entity_Matches_Spec (Entity (Nam), New_S) then
5502 Candidate_Renaming := New_S;
5504 if Is_Visible_Operation (Entity (Nam)) then
5505 Old_S := Entity (Nam);
5509 Present (First_Formal (Entity (Nam)))
5510 and then Present (First_Formal (New_S))
5511 and then (Base_Type (Etype (First_Formal (Entity (Nam))))
5512 = Base_Type (Etype (First_Formal (New_S))))
5514 Candidate_Renaming := Entity (Nam);
5518 Get_First_Interp (Nam, Ind, It);
5519 while Present (It.Nam) loop
5520 if Entity_Matches_Spec (It.Nam, New_S)
5521 and then Is_Visible_Operation (It.Nam)
5523 if Old_S /= Any_Id then
5525 -- Note: The call to Disambiguate only happens if a
5526 -- previous interpretation was found, in which case I1
5527 -- has received a value.
5529 It1 := Disambiguate (Nam, I1, Ind, Etype (Old_S));
5531 if It1 = No_Interp then
5532 Inst := Enclosing_Instance;
5534 if Present (Inst) then
5535 if Within (It.Nam, Inst) then
5536 if Within (Old_S, Inst) then
5538 -- Choose the innermost subprogram, which would
5539 -- have hidden the outer one in the generic.
5541 if Scope_Depth (It.Nam) <
5550 elsif Within (Old_S, Inst) then
5554 return Report_Overload;
5557 -- If not within an instance, ambiguity is real
5560 return Report_Overload;
5574 Present (First_Formal (It.Nam))
5575 and then Present (First_Formal (New_S))
5576 and then (Base_Type (Etype (First_Formal (It.Nam)))
5577 = Base_Type (Etype (First_Formal (New_S))))
5579 Candidate_Renaming := It.Nam;
5582 Get_Next_Interp (Ind, It);
5585 Set_Entity (Nam, Old_S);
5587 if Old_S /= Any_Id then
5588 Set_Is_Overloaded (Nam, False);
5593 end Find_Renamed_Entity;
5595 -----------------------------
5596 -- Find_Selected_Component --
5597 -----------------------------
5599 procedure Find_Selected_Component (N : Node_Id) is
5600 P : constant Node_Id := Prefix (N);
5603 -- Entity denoted by prefix
5613 if Nkind (P) = N_Error then
5617 -- Selector name cannot be a character literal or an operator symbol in
5618 -- SPARK, except for the operator symbol in a renaming.
5620 if Restriction_Check_Required (SPARK) then
5621 if Nkind (Selector_Name (N)) = N_Character_Literal then
5622 Check_SPARK_Restriction
5623 ("character literal cannot be prefixed", N);
5624 elsif Nkind (Selector_Name (N)) = N_Operator_Symbol
5625 and then Nkind (Parent (N)) /= N_Subprogram_Renaming_Declaration
5627 Check_SPARK_Restriction ("operator symbol cannot be prefixed", N);
5631 -- If the selector already has an entity, the node has been constructed
5632 -- in the course of expansion, and is known to be valid. Do not verify
5633 -- that it is defined for the type (it may be a private component used
5634 -- in the expansion of record equality).
5636 if Present (Entity (Selector_Name (N))) then
5638 or else Etype (N) = Any_Type
5641 Sel_Name : constant Node_Id := Selector_Name (N);
5642 Selector : constant Entity_Id := Entity (Sel_Name);
5646 Set_Etype (Sel_Name, Etype (Selector));
5648 if not Is_Entity_Name (P) then
5652 -- Build an actual subtype except for the first parameter
5653 -- of an init proc, where this actual subtype is by
5654 -- definition incorrect, since the object is uninitialized
5655 -- (and does not even have defined discriminants etc.)
5657 if Is_Entity_Name (P)
5658 and then Ekind (Entity (P)) = E_Function
5660 Nam := New_Copy (P);
5662 if Is_Overloaded (P) then
5663 Save_Interps (P, Nam);
5667 Make_Function_Call (Sloc (P), Name => Nam));
5669 Analyze_Selected_Component (N);
5672 elsif Ekind (Selector) = E_Component
5673 and then (not Is_Entity_Name (P)
5674 or else Chars (Entity (P)) /= Name_uInit)
5676 -- Do not build the subtype when referencing components of
5677 -- dispatch table wrappers. Required to avoid generating
5678 -- elaboration code with HI runtimes. JVM and .NET use a
5679 -- modified version of Ada.Tags which does not contain RE_
5680 -- Dispatch_Table_Wrapper and RE_No_Dispatch_Table_Wrapper.
5681 -- Avoid raising RE_Not_Available exception in those cases.
5683 if VM_Target = No_VM
5684 and then RTU_Loaded (Ada_Tags)
5686 ((RTE_Available (RE_Dispatch_Table_Wrapper)
5687 and then Scope (Selector) =
5688 RTE (RE_Dispatch_Table_Wrapper))
5690 (RTE_Available (RE_No_Dispatch_Table_Wrapper)
5691 and then Scope (Selector) =
5692 RTE (RE_No_Dispatch_Table_Wrapper)))
5698 Build_Actual_Subtype_Of_Component
5699 (Etype (Selector), N);
5706 if No (C_Etype) then
5707 C_Etype := Etype (Selector);
5709 Insert_Action (N, C_Etype);
5710 C_Etype := Defining_Identifier (C_Etype);
5713 Set_Etype (N, C_Etype);
5716 -- If this is the name of an entry or protected operation, and
5717 -- the prefix is an access type, insert an explicit dereference,
5718 -- so that entry calls are treated uniformly.
5720 if Is_Access_Type (Etype (P))
5721 and then Is_Concurrent_Type (Designated_Type (Etype (P)))
5724 New_P : constant Node_Id :=
5725 Make_Explicit_Dereference (Sloc (P),
5726 Prefix => Relocate_Node (P));
5729 Set_Etype (P, Designated_Type (Etype (Prefix (P))));
5733 -- If the selected component appears within a default expression
5734 -- and it has an actual subtype, the pre-analysis has not yet
5735 -- completed its analysis, because Insert_Actions is disabled in
5736 -- that context. Within the init proc of the enclosing type we
5737 -- must complete this analysis, if an actual subtype was created.
5739 elsif Inside_Init_Proc then
5741 Typ : constant Entity_Id := Etype (N);
5742 Decl : constant Node_Id := Declaration_Node (Typ);
5744 if Nkind (Decl) = N_Subtype_Declaration
5745 and then not Analyzed (Decl)
5746 and then Is_List_Member (Decl)
5747 and then No (Parent (Decl))
5750 Insert_Action (N, Decl);
5757 elsif Is_Entity_Name (P) then
5758 P_Name := Entity (P);
5760 -- The prefix may denote an enclosing type which is the completion
5761 -- of an incomplete type declaration.
5763 if Is_Type (P_Name) then
5764 Set_Entity (P, Get_Full_View (P_Name));
5765 Set_Etype (P, Entity (P));
5766 P_Name := Entity (P);
5769 P_Type := Base_Type (Etype (P));
5771 if Debug_Flag_E then
5772 Write_Str ("Found prefix type to be ");
5773 Write_Entity_Info (P_Type, " "); Write_Eol;
5776 -- First check for components of a record object (not the
5777 -- result of a call, which is handled below).
5779 if Is_Appropriate_For_Record (P_Type)
5780 and then not Is_Overloadable (P_Name)
5781 and then not Is_Type (P_Name)
5783 -- Selected component of record. Type checking will validate
5784 -- name of selector.
5785 -- ??? could we rewrite an implicit dereference into an explicit
5788 Analyze_Selected_Component (N);
5790 -- Reference to type name in predicate/invariant expression
5792 elsif Is_Appropriate_For_Entry_Prefix (P_Type)
5793 and then not In_Open_Scopes (P_Name)
5794 and then (not Is_Concurrent_Type (Etype (P_Name))
5795 or else not In_Open_Scopes (Etype (P_Name)))
5797 -- Call to protected operation or entry. Type checking is
5798 -- needed on the prefix.
5800 Analyze_Selected_Component (N);
5802 elsif (In_Open_Scopes (P_Name)
5803 and then Ekind (P_Name) /= E_Void
5804 and then not Is_Overloadable (P_Name))
5805 or else (Is_Concurrent_Type (Etype (P_Name))
5806 and then In_Open_Scopes (Etype (P_Name)))
5808 -- Prefix denotes an enclosing loop, block, or task, i.e. an
5809 -- enclosing construct that is not a subprogram or accept.
5811 Find_Expanded_Name (N);
5813 elsif Ekind (P_Name) = E_Package then
5814 Find_Expanded_Name (N);
5816 elsif Is_Overloadable (P_Name) then
5818 -- The subprogram may be a renaming (of an enclosing scope) as
5819 -- in the case of the name of the generic within an instantiation.
5821 if Ekind_In (P_Name, E_Procedure, E_Function)
5822 and then Present (Alias (P_Name))
5823 and then Is_Generic_Instance (Alias (P_Name))
5825 P_Name := Alias (P_Name);
5828 if Is_Overloaded (P) then
5830 -- The prefix must resolve to a unique enclosing construct
5833 Found : Boolean := False;
5838 Get_First_Interp (P, Ind, It);
5839 while Present (It.Nam) loop
5840 if In_Open_Scopes (It.Nam) then
5843 "prefix must be unique enclosing scope", N);
5844 Set_Entity (N, Any_Id);
5845 Set_Etype (N, Any_Type);
5854 Get_Next_Interp (Ind, It);
5859 if In_Open_Scopes (P_Name) then
5860 Set_Entity (P, P_Name);
5861 Set_Is_Overloaded (P, False);
5862 Find_Expanded_Name (N);
5865 -- If no interpretation as an expanded name is possible, it
5866 -- must be a selected component of a record returned by a
5867 -- function call. Reformat prefix as a function call, the rest
5868 -- is done by type resolution. If the prefix is procedure or
5869 -- entry, as is P.X; this is an error.
5871 if Ekind (P_Name) /= E_Function
5872 and then (not Is_Overloaded (P)
5874 Nkind (Parent (N)) = N_Procedure_Call_Statement)
5876 -- Prefix may mention a package that is hidden by a local
5877 -- declaration: let the user know. Scan the full homonym
5878 -- chain, the candidate package may be anywhere on it.
5880 if Present (Homonym (Current_Entity (P_Name))) then
5882 P_Name := Current_Entity (P_Name);
5884 while Present (P_Name) loop
5885 exit when Ekind (P_Name) = E_Package;
5886 P_Name := Homonym (P_Name);
5889 if Present (P_Name) then
5890 Error_Msg_Sloc := Sloc (Entity (Prefix (N)));
5893 ("package& is hidden by declaration#",
5896 Set_Entity (Prefix (N), P_Name);
5897 Find_Expanded_Name (N);
5900 P_Name := Entity (Prefix (N));
5905 ("invalid prefix in selected component&", N, P_Name);
5906 Change_Selected_Component_To_Expanded_Name (N);
5907 Set_Entity (N, Any_Id);
5908 Set_Etype (N, Any_Type);
5911 Nam := New_Copy (P);
5912 Save_Interps (P, Nam);
5914 Make_Function_Call (Sloc (P), Name => Nam));
5916 Analyze_Selected_Component (N);
5920 -- Remaining cases generate various error messages
5923 -- Format node as expanded name, to avoid cascaded errors
5925 Change_Selected_Component_To_Expanded_Name (N);
5926 Set_Entity (N, Any_Id);
5927 Set_Etype (N, Any_Type);
5929 -- Issue error message, but avoid this if error issued already.
5930 -- Use identifier of prefix if one is available.
5932 if P_Name = Any_Id then
5935 elsif Ekind (P_Name) = E_Void then
5936 Premature_Usage (P);
5938 elsif Nkind (P) /= N_Attribute_Reference then
5940 "invalid prefix in selected component&", P);
5942 if Is_Access_Type (P_Type)
5943 and then Ekind (Designated_Type (P_Type)) = E_Incomplete_Type
5946 ("\dereference must not be of an incomplete type " &
5952 "invalid prefix in selected component", P);
5956 -- Selector name is restricted in SPARK
5958 if Nkind (N) = N_Expanded_Name
5959 and then Restriction_Check_Required (SPARK)
5961 if Is_Subprogram (P_Name) then
5962 Check_SPARK_Restriction
5963 ("prefix of expanded name cannot be a subprogram", P);
5964 elsif Ekind (P_Name) = E_Loop then
5965 Check_SPARK_Restriction
5966 ("prefix of expanded name cannot be a loop statement", P);
5971 -- If prefix is not the name of an entity, it must be an expression,
5972 -- whose type is appropriate for a record. This is determined by
5975 Analyze_Selected_Component (N);
5977 end Find_Selected_Component;
5983 procedure Find_Type (N : Node_Id) is
5993 elsif Nkind (N) = N_Attribute_Reference then
5995 -- Class attribute. This is not valid in Ada 83 mode, but we do not
5996 -- need to enforce that at this point, since the declaration of the
5997 -- tagged type in the prefix would have been flagged already.
5999 if Attribute_Name (N) = Name_Class then
6000 Check_Restriction (No_Dispatch, N);
6001 Find_Type (Prefix (N));
6003 -- Propagate error from bad prefix
6005 if Etype (Prefix (N)) = Any_Type then
6006 Set_Entity (N, Any_Type);
6007 Set_Etype (N, Any_Type);
6011 T := Base_Type (Entity (Prefix (N)));
6013 -- Case where type is not known to be tagged. Its appearance in
6014 -- the prefix of the 'Class attribute indicates that the full view
6017 if not Is_Tagged_Type (T) then
6018 if Ekind (T) = E_Incomplete_Type then
6020 -- It is legal to denote the class type of an incomplete
6021 -- type. The full type will have to be tagged, of course.
6022 -- In Ada 2005 this usage is declared obsolescent, so we
6023 -- warn accordingly. This usage is only legal if the type
6024 -- is completed in the current scope, and not for a limited
6027 if not Is_Tagged_Type (T)
6028 and then Ada_Version >= Ada_2005
6030 if From_With_Type (T) then
6032 ("prefix of Class attribute must be tagged", N);
6033 Set_Etype (N, Any_Type);
6034 Set_Entity (N, Any_Type);
6037 -- ??? This test is temporarily disabled (always False)
6038 -- because it causes an unwanted warning on GNAT sources
6039 -- (built with -gnatg, which includes Warn_On_Obsolescent_
6040 -- Feature). Once this issue is cleared in the sources, it
6043 elsif Warn_On_Obsolescent_Feature
6047 ("applying 'Class to an untagged incomplete type"
6048 & " is an obsolescent feature (RM J.11)", N);
6052 Set_Is_Tagged_Type (T);
6053 Set_Direct_Primitive_Operations (T, New_Elmt_List);
6054 Make_Class_Wide_Type (T);
6055 Set_Entity (N, Class_Wide_Type (T));
6056 Set_Etype (N, Class_Wide_Type (T));
6058 elsif Ekind (T) = E_Private_Type
6059 and then not Is_Generic_Type (T)
6060 and then In_Private_Part (Scope (T))
6062 -- The Class attribute can be applied to an untagged private
6063 -- type fulfilled by a tagged type prior to the full type
6064 -- declaration (but only within the parent package's private
6065 -- part). Create the class-wide type now and check that the
6066 -- full type is tagged later during its analysis. Note that
6067 -- we do not mark the private type as tagged, unlike the
6068 -- case of incomplete types, because the type must still
6069 -- appear untagged to outside units.
6071 if No (Class_Wide_Type (T)) then
6072 Make_Class_Wide_Type (T);
6075 Set_Entity (N, Class_Wide_Type (T));
6076 Set_Etype (N, Class_Wide_Type (T));
6079 -- Should we introduce a type Any_Tagged and use Wrong_Type
6080 -- here, it would be a bit more consistent???
6083 ("tagged type required, found}",
6084 Prefix (N), First_Subtype (T));
6085 Set_Entity (N, Any_Type);
6089 -- Case of tagged type
6092 if Is_Concurrent_Type (T) then
6093 if No (Corresponding_Record_Type (Entity (Prefix (N)))) then
6095 -- Previous error. Use current type, which at least
6096 -- provides some operations.
6098 C := Entity (Prefix (N));
6101 C := Class_Wide_Type
6102 (Corresponding_Record_Type (Entity (Prefix (N))));
6106 C := Class_Wide_Type (Entity (Prefix (N)));
6109 Set_Entity_With_Style_Check (N, C);
6110 Generate_Reference (C, N);
6114 -- Base attribute, not allowed in Ada 83
6116 elsif Attribute_Name (N) = Name_Base then
6117 Error_Msg_Name_1 := Name_Base;
6118 Check_SPARK_Restriction
6119 ("attribute% is only allowed as prefix of another attribute", N);
6121 if Ada_Version = Ada_83 and then Comes_From_Source (N) then
6123 ("(Ada 83) Base attribute not allowed in subtype mark", N);
6126 Find_Type (Prefix (N));
6127 Typ := Entity (Prefix (N));
6129 if Ada_Version >= Ada_95
6130 and then not Is_Scalar_Type (Typ)
6131 and then not Is_Generic_Type (Typ)
6134 ("prefix of Base attribute must be scalar type",
6137 elsif Warn_On_Redundant_Constructs
6138 and then Base_Type (Typ) = Typ
6140 Error_Msg_NE -- CODEFIX
6141 ("?redundant attribute, & is its own base type", N, Typ);
6144 T := Base_Type (Typ);
6146 -- Rewrite attribute reference with type itself (see similar
6147 -- processing in Analyze_Attribute, case Base). Preserve prefix
6148 -- if present, for other legality checks.
6150 if Nkind (Prefix (N)) = N_Expanded_Name then
6152 Make_Expanded_Name (Sloc (N),
6154 Prefix => New_Copy (Prefix (Prefix (N))),
6155 Selector_Name => New_Reference_To (T, Sloc (N))));
6158 Rewrite (N, New_Reference_To (T, Sloc (N)));
6165 elsif Attribute_Name (N) = Name_Stub_Type then
6167 -- This is handled in Analyze_Attribute
6171 -- All other attributes are invalid in a subtype mark
6174 Error_Msg_N ("invalid attribute in subtype mark", N);
6180 if Is_Entity_Name (N) then
6181 T_Name := Entity (N);
6183 Error_Msg_N ("subtype mark required in this context", N);
6184 Set_Etype (N, Any_Type);
6188 if T_Name = Any_Id or else Etype (N) = Any_Type then
6190 -- Undefined id. Make it into a valid type
6192 Set_Entity (N, Any_Type);
6194 elsif not Is_Type (T_Name)
6195 and then T_Name /= Standard_Void_Type
6197 Error_Msg_Sloc := Sloc (T_Name);
6198 Error_Msg_N ("subtype mark required in this context", N);
6199 Error_Msg_NE ("\\found & declared#", N, T_Name);
6200 Set_Entity (N, Any_Type);
6203 -- If the type is an incomplete type created to handle
6204 -- anonymous access components of a record type, then the
6205 -- incomplete type is the visible entity and subsequent
6206 -- references will point to it. Mark the original full
6207 -- type as referenced, to prevent spurious warnings.
6209 if Is_Incomplete_Type (T_Name)
6210 and then Present (Full_View (T_Name))
6211 and then not Comes_From_Source (T_Name)
6213 Set_Referenced (Full_View (T_Name));
6216 T_Name := Get_Full_View (T_Name);
6218 -- Ada 2005 (AI-251, AI-50217): Handle interfaces visible through
6219 -- limited-with clauses
6221 if From_With_Type (T_Name)
6222 and then Ekind (T_Name) in Incomplete_Kind
6223 and then Present (Non_Limited_View (T_Name))
6224 and then Is_Interface (Non_Limited_View (T_Name))
6226 T_Name := Non_Limited_View (T_Name);
6229 if In_Open_Scopes (T_Name) then
6230 if Ekind (Base_Type (T_Name)) = E_Task_Type then
6232 -- In Ada 2005, a task name can be used in an access
6233 -- definition within its own body. It cannot be used
6234 -- in the discriminant part of the task declaration,
6235 -- nor anywhere else in the declaration because entries
6236 -- cannot have access parameters.
6238 if Ada_Version >= Ada_2005
6239 and then Nkind (Parent (N)) = N_Access_Definition
6241 Set_Entity (N, T_Name);
6242 Set_Etype (N, T_Name);
6244 if Has_Completion (T_Name) then
6249 ("task type cannot be used as type mark " &
6250 "within its own declaration", N);
6255 ("task type cannot be used as type mark " &
6256 "within its own spec or body", N);
6259 elsif Ekind (Base_Type (T_Name)) = E_Protected_Type then
6261 -- In Ada 2005, a protected name can be used in an access
6262 -- definition within its own body.
6264 if Ada_Version >= Ada_2005
6265 and then Nkind (Parent (N)) = N_Access_Definition
6267 Set_Entity (N, T_Name);
6268 Set_Etype (N, T_Name);
6273 ("protected type cannot be used as type mark " &
6274 "within its own spec or body", N);
6278 Error_Msg_N ("type declaration cannot refer to itself", N);
6281 Set_Etype (N, Any_Type);
6282 Set_Entity (N, Any_Type);
6283 Set_Error_Posted (T_Name);
6287 Set_Entity (N, T_Name);
6288 Set_Etype (N, T_Name);
6292 if Present (Etype (N)) and then Comes_From_Source (N) then
6293 if Is_Fixed_Point_Type (Etype (N)) then
6294 Check_Restriction (No_Fixed_Point, N);
6295 elsif Is_Floating_Point_Type (Etype (N)) then
6296 Check_Restriction (No_Floating_Point, N);
6301 ------------------------------------
6302 -- Has_Implicit_Character_Literal --
6303 ------------------------------------
6305 function Has_Implicit_Character_Literal (N : Node_Id) return Boolean is
6307 Found : Boolean := False;
6308 P : constant Entity_Id := Entity (Prefix (N));
6309 Priv_Id : Entity_Id := Empty;
6312 if Ekind (P) = E_Package
6313 and then not In_Open_Scopes (P)
6315 Priv_Id := First_Private_Entity (P);
6318 if P = Standard_Standard then
6319 Change_Selected_Component_To_Expanded_Name (N);
6320 Rewrite (N, Selector_Name (N));
6322 Set_Etype (Original_Node (N), Standard_Character);
6326 Id := First_Entity (P);
6328 and then Id /= Priv_Id
6330 if Is_Standard_Character_Type (Id) and then Is_Base_Type (Id) then
6332 -- We replace the node with the literal itself, resolve as a
6333 -- character, and set the type correctly.
6336 Change_Selected_Component_To_Expanded_Name (N);
6337 Rewrite (N, Selector_Name (N));
6340 Set_Etype (Original_Node (N), Id);
6344 -- More than one type derived from Character in given scope.
6345 -- Collect all possible interpretations.
6347 Add_One_Interp (N, Id, Id);
6355 end Has_Implicit_Character_Literal;
6357 ----------------------
6358 -- Has_Private_With --
6359 ----------------------
6361 function Has_Private_With (E : Entity_Id) return Boolean is
6362 Comp_Unit : constant Node_Id := Cunit (Current_Sem_Unit);
6366 Item := First (Context_Items (Comp_Unit));
6367 while Present (Item) loop
6368 if Nkind (Item) = N_With_Clause
6369 and then Private_Present (Item)
6370 and then Entity (Name (Item)) = E
6379 end Has_Private_With;
6381 ---------------------------
6382 -- Has_Implicit_Operator --
6383 ---------------------------
6385 function Has_Implicit_Operator (N : Node_Id) return Boolean is
6386 Op_Id : constant Name_Id := Chars (Selector_Name (N));
6387 P : constant Entity_Id := Entity (Prefix (N));
6389 Priv_Id : Entity_Id := Empty;
6391 procedure Add_Implicit_Operator
6393 Op_Type : Entity_Id := Empty);
6394 -- Add implicit interpretation to node N, using the type for which a
6395 -- predefined operator exists. If the operator yields a boolean type,
6396 -- the Operand_Type is implicitly referenced by the operator, and a
6397 -- reference to it must be generated.
6399 ---------------------------
6400 -- Add_Implicit_Operator --
6401 ---------------------------
6403 procedure Add_Implicit_Operator
6405 Op_Type : Entity_Id := Empty)
6407 Predef_Op : Entity_Id;
6410 Predef_Op := Current_Entity (Selector_Name (N));
6412 while Present (Predef_Op)
6413 and then Scope (Predef_Op) /= Standard_Standard
6415 Predef_Op := Homonym (Predef_Op);
6418 if Nkind (N) = N_Selected_Component then
6419 Change_Selected_Component_To_Expanded_Name (N);
6422 -- If the context is an unanalyzed function call, determine whether
6423 -- a binary or unary interpretation is required.
6425 if Nkind (Parent (N)) = N_Indexed_Component then
6427 Is_Binary_Call : constant Boolean :=
6429 (Next (First (Expressions (Parent (N)))));
6430 Is_Binary_Op : constant Boolean :=
6432 (Predef_Op) /= Last_Entity (Predef_Op);
6433 Predef_Op2 : constant Entity_Id := Homonym (Predef_Op);
6436 if Is_Binary_Call then
6437 if Is_Binary_Op then
6438 Add_One_Interp (N, Predef_Op, T);
6440 Add_One_Interp (N, Predef_Op2, T);
6444 if not Is_Binary_Op then
6445 Add_One_Interp (N, Predef_Op, T);
6447 Add_One_Interp (N, Predef_Op2, T);
6453 Add_One_Interp (N, Predef_Op, T);
6455 -- For operators with unary and binary interpretations, if
6456 -- context is not a call, add both
6458 if Present (Homonym (Predef_Op)) then
6459 Add_One_Interp (N, Homonym (Predef_Op), T);
6463 -- The node is a reference to a predefined operator, and
6464 -- an implicit reference to the type of its operands.
6466 if Present (Op_Type) then
6467 Generate_Operator_Reference (N, Op_Type);
6469 Generate_Operator_Reference (N, T);
6471 end Add_Implicit_Operator;
6473 -- Start of processing for Has_Implicit_Operator
6476 if Ekind (P) = E_Package
6477 and then not In_Open_Scopes (P)
6479 Priv_Id := First_Private_Entity (P);
6482 Id := First_Entity (P);
6486 -- Boolean operators: an implicit declaration exists if the scope
6487 -- contains a declaration for a derived Boolean type, or for an
6488 -- array of Boolean type.
6490 when Name_Op_And | Name_Op_Not | Name_Op_Or | Name_Op_Xor =>
6491 while Id /= Priv_Id loop
6492 if Valid_Boolean_Arg (Id) and then Is_Base_Type (Id) then
6493 Add_Implicit_Operator (Id);
6500 -- Equality: look for any non-limited type (result is Boolean)
6502 when Name_Op_Eq | Name_Op_Ne =>
6503 while Id /= Priv_Id loop
6505 and then not Is_Limited_Type (Id)
6506 and then Is_Base_Type (Id)
6508 Add_Implicit_Operator (Standard_Boolean, Id);
6515 -- Comparison operators: scalar type, or array of scalar
6517 when Name_Op_Lt | Name_Op_Le | Name_Op_Gt | Name_Op_Ge =>
6518 while Id /= Priv_Id loop
6519 if (Is_Scalar_Type (Id)
6520 or else (Is_Array_Type (Id)
6521 and then Is_Scalar_Type (Component_Type (Id))))
6522 and then Is_Base_Type (Id)
6524 Add_Implicit_Operator (Standard_Boolean, Id);
6531 -- Arithmetic operators: any numeric type
6541 while Id /= Priv_Id loop
6542 if Is_Numeric_Type (Id) and then Is_Base_Type (Id) then
6543 Add_Implicit_Operator (Id);
6550 -- Concatenation: any one-dimensional array type
6552 when Name_Op_Concat =>
6553 while Id /= Priv_Id loop
6554 if Is_Array_Type (Id)
6555 and then Number_Dimensions (Id) = 1
6556 and then Is_Base_Type (Id)
6558 Add_Implicit_Operator (Id);
6565 -- What is the others condition here? Should we be using a
6566 -- subtype of Name_Id that would restrict to operators ???
6568 when others => null;
6571 -- If we fall through, then we do not have an implicit operator
6575 end Has_Implicit_Operator;
6577 -----------------------------------
6578 -- Has_Loop_In_Inner_Open_Scopes --
6579 -----------------------------------
6581 function Has_Loop_In_Inner_Open_Scopes (S : Entity_Id) return Boolean is
6583 -- Several scope stacks are maintained by Scope_Stack. The base of the
6584 -- currently active scope stack is denoted by the Is_Active_Stack_Base
6585 -- flag in the scope stack entry. Note that the scope stacks used to
6586 -- simply be delimited implicitly by the presence of Standard_Standard
6587 -- at their base, but there now are cases where this is not sufficient
6588 -- because Standard_Standard actually may appear in the middle of the
6589 -- active set of scopes.
6591 for J in reverse 0 .. Scope_Stack.Last loop
6593 -- S was reached without seing a loop scope first
6595 if Scope_Stack.Table (J).Entity = S then
6598 -- S was not yet reached, so it contains at least one inner loop
6600 elsif Ekind (Scope_Stack.Table (J).Entity) = E_Loop then
6604 -- Check Is_Active_Stack_Base to tell us when to stop, as there are
6605 -- cases where Standard_Standard appears in the middle of the active
6606 -- set of scopes. This affects the declaration and overriding of
6607 -- private inherited operations in instantiations of generic child
6610 pragma Assert (not Scope_Stack.Table (J).Is_Active_Stack_Base);
6613 raise Program_Error; -- unreachable
6614 end Has_Loop_In_Inner_Open_Scopes;
6616 --------------------
6617 -- In_Open_Scopes --
6618 --------------------
6620 function In_Open_Scopes (S : Entity_Id) return Boolean is
6622 -- Several scope stacks are maintained by Scope_Stack. The base of the
6623 -- currently active scope stack is denoted by the Is_Active_Stack_Base
6624 -- flag in the scope stack entry. Note that the scope stacks used to
6625 -- simply be delimited implicitly by the presence of Standard_Standard
6626 -- at their base, but there now are cases where this is not sufficient
6627 -- because Standard_Standard actually may appear in the middle of the
6628 -- active set of scopes.
6630 for J in reverse 0 .. Scope_Stack.Last loop
6631 if Scope_Stack.Table (J).Entity = S then
6635 -- Check Is_Active_Stack_Base to tell us when to stop, as there are
6636 -- cases where Standard_Standard appears in the middle of the active
6637 -- set of scopes. This affects the declaration and overriding of
6638 -- private inherited operations in instantiations of generic child
6641 exit when Scope_Stack.Table (J).Is_Active_Stack_Base;
6647 -----------------------------
6648 -- Inherit_Renamed_Profile --
6649 -----------------------------
6651 procedure Inherit_Renamed_Profile (New_S : Entity_Id; Old_S : Entity_Id) is
6658 if Ekind (Old_S) = E_Operator then
6659 New_F := First_Formal (New_S);
6661 while Present (New_F) loop
6662 Set_Etype (New_F, Base_Type (Etype (New_F)));
6663 Next_Formal (New_F);
6666 Set_Etype (New_S, Base_Type (Etype (New_S)));
6669 New_F := First_Formal (New_S);
6670 Old_F := First_Formal (Old_S);
6672 while Present (New_F) loop
6673 New_T := Etype (New_F);
6674 Old_T := Etype (Old_F);
6676 -- If the new type is a renaming of the old one, as is the
6677 -- case for actuals in instances, retain its name, to simplify
6678 -- later disambiguation.
6680 if Nkind (Parent (New_T)) = N_Subtype_Declaration
6681 and then Is_Entity_Name (Subtype_Indication (Parent (New_T)))
6682 and then Entity (Subtype_Indication (Parent (New_T))) = Old_T
6686 Set_Etype (New_F, Old_T);
6689 Next_Formal (New_F);
6690 Next_Formal (Old_F);
6693 if Ekind_In (Old_S, E_Function, E_Enumeration_Literal) then
6694 Set_Etype (New_S, Etype (Old_S));
6697 end Inherit_Renamed_Profile;
6703 procedure Initialize is
6708 -------------------------
6709 -- Install_Use_Clauses --
6710 -------------------------
6712 procedure Install_Use_Clauses
6714 Force_Installation : Boolean := False)
6722 while Present (U) loop
6724 -- Case of USE package
6726 if Nkind (U) = N_Use_Package_Clause then
6727 P := First (Names (U));
6728 while Present (P) loop
6731 if Ekind (Id) = E_Package then
6733 Note_Redundant_Use (P);
6735 elsif Present (Renamed_Object (Id))
6736 and then In_Use (Renamed_Object (Id))
6738 Note_Redundant_Use (P);
6740 elsif Force_Installation or else Applicable_Use (P) then
6741 Use_One_Package (Id, U);
6752 P := First (Subtype_Marks (U));
6753 while Present (P) loop
6754 if not Is_Entity_Name (P)
6755 or else No (Entity (P))
6759 elsif Entity (P) /= Any_Type then
6767 Next_Use_Clause (U);
6769 end Install_Use_Clauses;
6771 -------------------------------------
6772 -- Is_Appropriate_For_Entry_Prefix --
6773 -------------------------------------
6775 function Is_Appropriate_For_Entry_Prefix (T : Entity_Id) return Boolean is
6776 P_Type : Entity_Id := T;
6779 if Is_Access_Type (P_Type) then
6780 P_Type := Designated_Type (P_Type);
6783 return Is_Task_Type (P_Type) or else Is_Protected_Type (P_Type);
6784 end Is_Appropriate_For_Entry_Prefix;
6786 -------------------------------
6787 -- Is_Appropriate_For_Record --
6788 -------------------------------
6790 function Is_Appropriate_For_Record (T : Entity_Id) return Boolean is
6792 function Has_Components (T1 : Entity_Id) return Boolean;
6793 -- Determine if given type has components (i.e. is either a record
6794 -- type or a type that has discriminants).
6796 --------------------
6797 -- Has_Components --
6798 --------------------
6800 function Has_Components (T1 : Entity_Id) return Boolean is
6802 return Is_Record_Type (T1)
6803 or else (Is_Private_Type (T1) and then Has_Discriminants (T1))
6804 or else (Is_Task_Type (T1) and then Has_Discriminants (T1))
6805 or else (Is_Incomplete_Type (T1)
6806 and then From_With_Type (T1)
6807 and then Present (Non_Limited_View (T1))
6808 and then Is_Record_Type
6809 (Get_Full_View (Non_Limited_View (T1))));
6812 -- Start of processing for Is_Appropriate_For_Record
6817 and then (Has_Components (T)
6818 or else (Is_Access_Type (T)
6819 and then Has_Components (Designated_Type (T))));
6820 end Is_Appropriate_For_Record;
6822 ------------------------
6823 -- Note_Redundant_Use --
6824 ------------------------
6826 procedure Note_Redundant_Use (Clause : Node_Id) is
6827 Pack_Name : constant Entity_Id := Entity (Clause);
6828 Cur_Use : constant Node_Id := Current_Use_Clause (Pack_Name);
6829 Decl : constant Node_Id := Parent (Clause);
6831 Prev_Use : Node_Id := Empty;
6832 Redundant : Node_Id := Empty;
6833 -- The Use_Clause which is actually redundant. In the simplest case it
6834 -- is Pack itself, but when we compile a body we install its context
6835 -- before that of its spec, in which case it is the use_clause in the
6836 -- spec that will appear to be redundant, and we want the warning to be
6837 -- placed on the body. Similar complications appear when the redundancy
6838 -- is between a child unit and one of its ancestors.
6841 Set_Redundant_Use (Clause, True);
6843 if not Comes_From_Source (Clause)
6845 or else not Warn_On_Redundant_Constructs
6850 if not Is_Compilation_Unit (Current_Scope) then
6852 -- If the use_clause is in an inner scope, it is made redundant by
6853 -- some clause in the current context, with one exception: If we're
6854 -- compiling a nested package body, and the use_clause comes from the
6855 -- corresponding spec, the clause is not necessarily fully redundant,
6856 -- so we should not warn. If a warning was warranted, it would have
6857 -- been given when the spec was processed.
6859 if Nkind (Parent (Decl)) = N_Package_Specification then
6861 Package_Spec_Entity : constant Entity_Id :=
6862 Defining_Unit_Name (Parent (Decl));
6864 if In_Package_Body (Package_Spec_Entity) then
6870 Redundant := Clause;
6871 Prev_Use := Cur_Use;
6873 elsif Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Body then
6875 Cur_Unit : constant Unit_Number_Type := Get_Source_Unit (Cur_Use);
6876 New_Unit : constant Unit_Number_Type := Get_Source_Unit (Clause);
6880 if Cur_Unit = New_Unit then
6882 -- Redundant clause in same body
6884 Redundant := Clause;
6885 Prev_Use := Cur_Use;
6887 elsif Cur_Unit = Current_Sem_Unit then
6889 -- If the new clause is not in the current unit it has been
6890 -- analyzed first, and it makes the other one redundant.
6891 -- However, if the new clause appears in a subunit, Cur_Unit
6892 -- is still the parent, and in that case the redundant one
6893 -- is the one appearing in the subunit.
6895 if Nkind (Unit (Cunit (New_Unit))) = N_Subunit then
6896 Redundant := Clause;
6897 Prev_Use := Cur_Use;
6899 -- Most common case: redundant clause in body,
6900 -- original clause in spec. Current scope is spec entity.
6905 Unit (Library_Unit (Cunit (Current_Sem_Unit))))
6907 Redundant := Cur_Use;
6911 -- The new clause may appear in an unrelated unit, when
6912 -- the parents of a generic are being installed prior to
6913 -- instantiation. In this case there must be no warning.
6914 -- We detect this case by checking whether the current top
6915 -- of the stack is related to the current compilation.
6917 Scop := Current_Scope;
6918 while Present (Scop)
6919 and then Scop /= Standard_Standard
6921 if Is_Compilation_Unit (Scop)
6922 and then not Is_Child_Unit (Scop)
6926 elsif Scop = Cunit_Entity (Current_Sem_Unit) then
6930 Scop := Scope (Scop);
6933 Redundant := Cur_Use;
6937 elsif New_Unit = Current_Sem_Unit then
6938 Redundant := Clause;
6939 Prev_Use := Cur_Use;
6942 -- Neither is the current unit, so they appear in parent or
6943 -- sibling units. Warning will be emitted elsewhere.
6949 elsif Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Declaration
6950 and then Present (Parent_Spec (Unit (Cunit (Current_Sem_Unit))))
6952 -- Use_clause is in child unit of current unit, and the child unit
6953 -- appears in the context of the body of the parent, so it has been
6954 -- installed first, even though it is the redundant one. Depending on
6955 -- their placement in the context, the visible or the private parts
6956 -- of the two units, either might appear as redundant, but the
6957 -- message has to be on the current unit.
6959 if Get_Source_Unit (Cur_Use) = Current_Sem_Unit then
6960 Redundant := Cur_Use;
6963 Redundant := Clause;
6964 Prev_Use := Cur_Use;
6967 -- If the new use clause appears in the private part of a parent unit
6968 -- it may appear to be redundant w.r.t. a use clause in a child unit,
6969 -- but the previous use clause was needed in the visible part of the
6970 -- child, and no warning should be emitted.
6972 if Nkind (Parent (Decl)) = N_Package_Specification
6974 List_Containing (Decl) = Private_Declarations (Parent (Decl))
6977 Par : constant Entity_Id := Defining_Entity (Parent (Decl));
6978 Spec : constant Node_Id :=
6979 Specification (Unit (Cunit (Current_Sem_Unit)));
6982 if Is_Compilation_Unit (Par)
6983 and then Par /= Cunit_Entity (Current_Sem_Unit)
6984 and then Parent (Cur_Use) = Spec
6986 List_Containing (Cur_Use) = Visible_Declarations (Spec)
6993 -- Finally, if the current use clause is in the context then
6994 -- the clause is redundant when it is nested within the unit.
6996 elsif Nkind (Parent (Cur_Use)) = N_Compilation_Unit
6997 and then Nkind (Parent (Parent (Clause))) /= N_Compilation_Unit
6998 and then Get_Source_Unit (Cur_Use) = Get_Source_Unit (Clause)
7000 Redundant := Clause;
7001 Prev_Use := Cur_Use;
7007 if Present (Redundant) then
7008 Error_Msg_Sloc := Sloc (Prev_Use);
7009 Error_Msg_NE -- CODEFIX
7010 ("& is already use-visible through previous use clause #?",
7011 Redundant, Pack_Name);
7013 end Note_Redundant_Use;
7019 procedure Pop_Scope is
7020 SST : Scope_Stack_Entry renames Scope_Stack.Table (Scope_Stack.Last);
7021 S : constant Entity_Id := SST.Entity;
7024 if Debug_Flag_E then
7028 -- Set Default_Storage_Pool field of the library unit if necessary
7030 if Ekind_In (S, E_Package, E_Generic_Package)
7032 Nkind (Parent (Unit_Declaration_Node (S))) = N_Compilation_Unit
7035 Aux : constant Node_Id :=
7036 Aux_Decls_Node (Parent (Unit_Declaration_Node (S)));
7038 if No (Default_Storage_Pool (Aux)) then
7039 Set_Default_Storage_Pool (Aux, Default_Pool);
7044 Scope_Suppress := SST.Save_Scope_Suppress;
7045 Local_Suppress_Stack_Top := SST.Save_Local_Suppress_Stack_Top;
7046 Check_Policy_List := SST.Save_Check_Policy_List;
7047 Default_Pool := SST.Save_Default_Storage_Pool;
7049 if Debug_Flag_W then
7050 Write_Str ("<-- exiting scope: ");
7051 Write_Name (Chars (Current_Scope));
7052 Write_Str (", Depth=");
7053 Write_Int (Int (Scope_Stack.Last));
7057 End_Use_Clauses (SST.First_Use_Clause);
7059 -- If the actions to be wrapped are still there they will get lost
7060 -- causing incomplete code to be generated. It is better to abort in
7061 -- this case (and we do the abort even with assertions off since the
7062 -- penalty is incorrect code generation)
7064 if SST.Actions_To_Be_Wrapped_Before /= No_List
7066 SST.Actions_To_Be_Wrapped_After /= No_List
7068 raise Program_Error;
7071 -- Free last subprogram name if allocated, and pop scope
7073 Free (SST.Last_Subprogram_Name);
7074 Scope_Stack.Decrement_Last;
7081 procedure Push_Scope (S : Entity_Id) is
7082 E : constant Entity_Id := Scope (S);
7085 if Ekind (S) = E_Void then
7088 -- Set scope depth if not a non-concurrent type, and we have not yet set
7089 -- the scope depth. This means that we have the first occurrence of the
7090 -- scope, and this is where the depth is set.
7092 elsif (not Is_Type (S) or else Is_Concurrent_Type (S))
7093 and then not Scope_Depth_Set (S)
7095 if S = Standard_Standard then
7096 Set_Scope_Depth_Value (S, Uint_0);
7098 elsif Is_Child_Unit (S) then
7099 Set_Scope_Depth_Value (S, Uint_1);
7101 elsif not Is_Record_Type (Current_Scope) then
7102 if Ekind (S) = E_Loop then
7103 Set_Scope_Depth_Value (S, Scope_Depth (Current_Scope));
7105 Set_Scope_Depth_Value (S, Scope_Depth (Current_Scope) + 1);
7110 Scope_Stack.Increment_Last;
7113 SST : Scope_Stack_Entry renames Scope_Stack.Table (Scope_Stack.Last);
7117 SST.Save_Scope_Suppress := Scope_Suppress;
7118 SST.Save_Local_Suppress_Stack_Top := Local_Suppress_Stack_Top;
7119 SST.Save_Check_Policy_List := Check_Policy_List;
7120 SST.Save_Default_Storage_Pool := Default_Pool;
7122 if Scope_Stack.Last > Scope_Stack.First then
7123 SST.Component_Alignment_Default := Scope_Stack.Table
7124 (Scope_Stack.Last - 1).
7125 Component_Alignment_Default;
7128 SST.Last_Subprogram_Name := null;
7129 SST.Is_Transient := False;
7130 SST.Node_To_Be_Wrapped := Empty;
7131 SST.Pending_Freeze_Actions := No_List;
7132 SST.Actions_To_Be_Wrapped_Before := No_List;
7133 SST.Actions_To_Be_Wrapped_After := No_List;
7134 SST.First_Use_Clause := Empty;
7135 SST.Is_Active_Stack_Base := False;
7136 SST.Previous_Visibility := False;
7139 if Debug_Flag_W then
7140 Write_Str ("--> new scope: ");
7141 Write_Name (Chars (Current_Scope));
7142 Write_Str (", Id=");
7143 Write_Int (Int (Current_Scope));
7144 Write_Str (", Depth=");
7145 Write_Int (Int (Scope_Stack.Last));
7149 -- Deal with copying flags from the previous scope to this one. This is
7150 -- not necessary if either scope is standard, or if the new scope is a
7153 if S /= Standard_Standard
7154 and then Scope (S) /= Standard_Standard
7155 and then not Is_Child_Unit (S)
7157 if Nkind (E) not in N_Entity then
7161 -- Copy categorization flags from Scope (S) to S, this is not done
7162 -- when Scope (S) is Standard_Standard since propagation is from
7163 -- library unit entity inwards. Copy other relevant attributes as
7164 -- well (Discard_Names in particular).
7166 -- We only propagate inwards for library level entities,
7167 -- inner level subprograms do not inherit the categorization.
7169 if Is_Library_Level_Entity (S) then
7170 Set_Is_Preelaborated (S, Is_Preelaborated (E));
7171 Set_Is_Shared_Passive (S, Is_Shared_Passive (E));
7172 Set_Discard_Names (S, Discard_Names (E));
7173 Set_Suppress_Value_Tracking_On_Call
7174 (S, Suppress_Value_Tracking_On_Call (E));
7175 Set_Categorization_From_Scope (E => S, Scop => E);
7179 if Is_Child_Unit (S)
7180 and then Present (E)
7181 and then Ekind_In (E, E_Package, E_Generic_Package)
7183 Nkind (Parent (Unit_Declaration_Node (E))) = N_Compilation_Unit
7186 Aux : constant Node_Id :=
7187 Aux_Decls_Node (Parent (Unit_Declaration_Node (E)));
7189 if Present (Default_Storage_Pool (Aux)) then
7190 Default_Pool := Default_Storage_Pool (Aux);
7196 ---------------------
7197 -- Premature_Usage --
7198 ---------------------
7200 procedure Premature_Usage (N : Node_Id) is
7201 Kind : constant Node_Kind := Nkind (Parent (Entity (N)));
7202 E : Entity_Id := Entity (N);
7205 -- Within an instance, the analysis of the actual for a formal object
7206 -- does not see the name of the object itself. This is significant only
7207 -- if the object is an aggregate, where its analysis does not do any
7208 -- name resolution on component associations. (see 4717-008). In such a
7209 -- case, look for the visible homonym on the chain.
7212 and then Present (Homonym (E))
7217 and then not In_Open_Scopes (Scope (E))
7224 Set_Etype (N, Etype (E));
7229 if Kind = N_Component_Declaration then
7231 ("component&! cannot be used before end of record declaration", N);
7233 elsif Kind = N_Parameter_Specification then
7235 ("formal parameter&! cannot be used before end of specification",
7238 elsif Kind = N_Discriminant_Specification then
7240 ("discriminant&! cannot be used before end of discriminant part",
7243 elsif Kind = N_Procedure_Specification
7244 or else Kind = N_Function_Specification
7247 ("subprogram&! cannot be used before end of its declaration",
7250 elsif Kind = N_Full_Type_Declaration then
7252 ("type& cannot be used before end of its declaration!", N);
7256 ("object& cannot be used before end of its declaration!", N);
7258 end Premature_Usage;
7260 ------------------------
7261 -- Present_System_Aux --
7262 ------------------------
7264 function Present_System_Aux (N : Node_Id := Empty) return Boolean is
7266 Aux_Name : Unit_Name_Type;
7267 Unum : Unit_Number_Type;
7272 function Find_System (C_Unit : Node_Id) return Entity_Id;
7273 -- Scan context clause of compilation unit to find with_clause
7280 function Find_System (C_Unit : Node_Id) return Entity_Id is
7281 With_Clause : Node_Id;
7284 With_Clause := First (Context_Items (C_Unit));
7285 while Present (With_Clause) loop
7286 if (Nkind (With_Clause) = N_With_Clause
7287 and then Chars (Name (With_Clause)) = Name_System)
7288 and then Comes_From_Source (With_Clause)
7299 -- Start of processing for Present_System_Aux
7302 -- The child unit may have been loaded and analyzed already
7304 if Present (System_Aux_Id) then
7307 -- If no previous pragma for System.Aux, nothing to load
7309 elsif No (System_Extend_Unit) then
7312 -- Use the unit name given in the pragma to retrieve the unit.
7313 -- Verify that System itself appears in the context clause of the
7314 -- current compilation. If System is not present, an error will
7315 -- have been reported already.
7318 With_Sys := Find_System (Cunit (Current_Sem_Unit));
7320 The_Unit := Unit (Cunit (Current_Sem_Unit));
7324 (Nkind (The_Unit) = N_Package_Body
7325 or else (Nkind (The_Unit) = N_Subprogram_Body
7327 not Acts_As_Spec (Cunit (Current_Sem_Unit))))
7329 With_Sys := Find_System (Library_Unit (Cunit (Current_Sem_Unit)));
7333 and then Present (N)
7335 -- If we are compiling a subunit, we need to examine its
7336 -- context as well (Current_Sem_Unit is the parent unit);
7338 The_Unit := Parent (N);
7339 while Nkind (The_Unit) /= N_Compilation_Unit loop
7340 The_Unit := Parent (The_Unit);
7343 if Nkind (Unit (The_Unit)) = N_Subunit then
7344 With_Sys := Find_System (The_Unit);
7348 if No (With_Sys) then
7352 Loc := Sloc (With_Sys);
7353 Get_Name_String (Chars (Expression (System_Extend_Unit)));
7354 Name_Buffer (8 .. Name_Len + 7) := Name_Buffer (1 .. Name_Len);
7355 Name_Buffer (1 .. 7) := "system.";
7356 Name_Buffer (Name_Len + 8) := '%';
7357 Name_Buffer (Name_Len + 9) := 's';
7358 Name_Len := Name_Len + 9;
7359 Aux_Name := Name_Find;
7363 (Load_Name => Aux_Name,
7366 Error_Node => With_Sys);
7368 if Unum /= No_Unit then
7369 Semantics (Cunit (Unum));
7371 Defining_Entity (Specification (Unit (Cunit (Unum))));
7374 Make_With_Clause (Loc,
7376 Make_Expanded_Name (Loc,
7377 Chars => Chars (System_Aux_Id),
7378 Prefix => New_Reference_To (Scope (System_Aux_Id), Loc),
7379 Selector_Name => New_Reference_To (System_Aux_Id, Loc)));
7381 Set_Entity (Name (Withn), System_Aux_Id);
7383 Set_Library_Unit (Withn, Cunit (Unum));
7384 Set_Corresponding_Spec (Withn, System_Aux_Id);
7385 Set_First_Name (Withn, True);
7386 Set_Implicit_With (Withn, True);
7388 Insert_After (With_Sys, Withn);
7389 Mark_Rewrite_Insertion (Withn);
7390 Set_Context_Installed (Withn);
7394 -- Here if unit load failed
7397 Error_Msg_Name_1 := Name_System;
7398 Error_Msg_Name_2 := Chars (Expression (System_Extend_Unit));
7400 ("extension package `%.%` does not exist",
7401 Opt.System_Extend_Unit);
7405 end Present_System_Aux;
7407 -------------------------
7408 -- Restore_Scope_Stack --
7409 -------------------------
7411 procedure Restore_Scope_Stack (Handle_Use : Boolean := True) is
7414 Comp_Unit : Node_Id;
7415 In_Child : Boolean := False;
7416 Full_Vis : Boolean := True;
7417 SS_Last : constant Int := Scope_Stack.Last;
7420 -- Restore visibility of previous scope stack, if any
7422 for J in reverse 0 .. Scope_Stack.Last loop
7423 exit when Scope_Stack.Table (J).Entity = Standard_Standard
7424 or else No (Scope_Stack.Table (J).Entity);
7426 S := Scope_Stack.Table (J).Entity;
7428 if not Is_Hidden_Open_Scope (S) then
7430 -- If the parent scope is hidden, its entities are hidden as
7431 -- well, unless the entity is the instantiation currently
7434 if not Is_Hidden_Open_Scope (Scope (S))
7435 or else not Analyzed (Parent (S))
7436 or else Scope (S) = Standard_Standard
7438 Set_Is_Immediately_Visible (S, True);
7441 E := First_Entity (S);
7442 while Present (E) loop
7443 if Is_Child_Unit (E) then
7444 if not From_With_Type (E) then
7445 Set_Is_Immediately_Visible (E,
7446 Is_Visible_Child_Unit (E) or else In_Open_Scopes (E));
7450 (Nkind (Parent (E)) = N_Defining_Program_Unit_Name
7452 Nkind (Parent (Parent (E))) = N_Package_Specification);
7453 Set_Is_Immediately_Visible (E,
7454 Limited_View_Installed (Parent (Parent (E))));
7457 Set_Is_Immediately_Visible (E, True);
7463 and then Is_Package_Or_Generic_Package (S)
7465 -- We are in the visible part of the package scope
7467 exit when E = First_Private_Entity (S);
7471 -- The visibility of child units (siblings of current compilation)
7472 -- must be restored in any case. Their declarations may appear
7473 -- after the private part of the parent.
7475 if not Full_Vis then
7476 while Present (E) loop
7477 if Is_Child_Unit (E) then
7478 Set_Is_Immediately_Visible (E,
7479 Is_Visible_Child_Unit (E) or else In_Open_Scopes (E));
7487 if Is_Child_Unit (S)
7488 and not In_Child -- check only for current unit
7492 -- Restore visibility of parents according to whether the child
7493 -- is private and whether we are in its visible part.
7495 Comp_Unit := Parent (Unit_Declaration_Node (S));
7497 if Nkind (Comp_Unit) = N_Compilation_Unit
7498 and then Private_Present (Comp_Unit)
7502 elsif Is_Package_Or_Generic_Package (S)
7503 and then (In_Private_Part (S) or else In_Package_Body (S))
7507 -- if S is the scope of some instance (which has already been
7508 -- seen on the stack) it does not affect the visibility of
7511 elsif Is_Hidden_Open_Scope (S) then
7514 elsif (Ekind (S) = E_Procedure
7515 or else Ekind (S) = E_Function)
7516 and then Has_Completion (S)
7527 if SS_Last >= Scope_Stack.First
7528 and then Scope_Stack.Table (SS_Last).Entity /= Standard_Standard
7531 Install_Use_Clauses (Scope_Stack.Table (SS_Last).First_Use_Clause);
7533 end Restore_Scope_Stack;
7535 ----------------------
7536 -- Save_Scope_Stack --
7537 ----------------------
7539 procedure Save_Scope_Stack (Handle_Use : Boolean := True) is
7542 SS_Last : constant Int := Scope_Stack.Last;
7545 if SS_Last >= Scope_Stack.First
7546 and then Scope_Stack.Table (SS_Last).Entity /= Standard_Standard
7549 End_Use_Clauses (Scope_Stack.Table (SS_Last).First_Use_Clause);
7552 -- If the call is from within a compilation unit, as when called from
7553 -- Rtsfind, make current entries in scope stack invisible while we
7554 -- analyze the new unit.
7556 for J in reverse 0 .. SS_Last loop
7557 exit when Scope_Stack.Table (J).Entity = Standard_Standard
7558 or else No (Scope_Stack.Table (J).Entity);
7560 S := Scope_Stack.Table (J).Entity;
7561 Set_Is_Immediately_Visible (S, False);
7563 E := First_Entity (S);
7564 while Present (E) loop
7565 Set_Is_Immediately_Visible (E, False);
7571 end Save_Scope_Stack;
7577 procedure Set_Use (L : List_Id) is
7579 Pack_Name : Node_Id;
7586 while Present (Decl) loop
7587 if Nkind (Decl) = N_Use_Package_Clause then
7588 Chain_Use_Clause (Decl);
7590 Pack_Name := First (Names (Decl));
7591 while Present (Pack_Name) loop
7592 Pack := Entity (Pack_Name);
7594 if Ekind (Pack) = E_Package
7595 and then Applicable_Use (Pack_Name)
7597 Use_One_Package (Pack, Decl);
7603 elsif Nkind (Decl) = N_Use_Type_Clause then
7604 Chain_Use_Clause (Decl);
7606 Id := First (Subtype_Marks (Decl));
7607 while Present (Id) loop
7608 if Entity (Id) /= Any_Type then
7621 ---------------------
7622 -- Use_One_Package --
7623 ---------------------
7625 procedure Use_One_Package (P : Entity_Id; N : Node_Id) is
7628 Current_Instance : Entity_Id := Empty;
7630 Private_With_OK : Boolean := False;
7633 if Ekind (P) /= E_Package then
7638 Set_Current_Use_Clause (P, N);
7640 -- Ada 2005 (AI-50217): Check restriction
7642 if From_With_Type (P) then
7643 Error_Msg_N ("limited withed package cannot appear in use clause", N);
7646 -- Find enclosing instance, if any
7649 Current_Instance := Current_Scope;
7650 while not Is_Generic_Instance (Current_Instance) loop
7651 Current_Instance := Scope (Current_Instance);
7654 if No (Hidden_By_Use_Clause (N)) then
7655 Set_Hidden_By_Use_Clause (N, New_Elmt_List);
7659 -- If unit is a package renaming, indicate that the renamed
7660 -- package is also in use (the flags on both entities must
7661 -- remain consistent, and a subsequent use of either of them
7662 -- should be recognized as redundant).
7664 if Present (Renamed_Object (P)) then
7665 Set_In_Use (Renamed_Object (P));
7666 Set_Current_Use_Clause (Renamed_Object (P), N);
7667 Real_P := Renamed_Object (P);
7672 -- Ada 2005 (AI-262): Check the use_clause of a private withed package
7673 -- found in the private part of a package specification
7675 if In_Private_Part (Current_Scope)
7676 and then Has_Private_With (P)
7677 and then Is_Child_Unit (Current_Scope)
7678 and then Is_Child_Unit (P)
7679 and then Is_Ancestor_Package (Scope (Current_Scope), P)
7681 Private_With_OK := True;
7684 -- Loop through entities in one package making them potentially
7687 Id := First_Entity (P);
7689 and then (Id /= First_Private_Entity (P)
7690 or else Private_With_OK) -- Ada 2005 (AI-262)
7692 Prev := Current_Entity (Id);
7693 while Present (Prev) loop
7694 if Is_Immediately_Visible (Prev)
7695 and then (not Is_Overloadable (Prev)
7696 or else not Is_Overloadable (Id)
7697 or else (Type_Conformant (Id, Prev)))
7699 if No (Current_Instance) then
7701 -- Potentially use-visible entity remains hidden
7703 goto Next_Usable_Entity;
7705 -- A use clause within an instance hides outer global entities,
7706 -- which are not used to resolve local entities in the
7707 -- instance. Note that the predefined entities in Standard
7708 -- could not have been hidden in the generic by a use clause,
7709 -- and therefore remain visible. Other compilation units whose
7710 -- entities appear in Standard must be hidden in an instance.
7712 -- To determine whether an entity is external to the instance
7713 -- we compare the scope depth of its scope with that of the
7714 -- current instance. However, a generic actual of a subprogram
7715 -- instance is declared in the wrapper package but will not be
7716 -- hidden by a use-visible entity. similarly, an entity that is
7717 -- declared in an enclosing instance will not be hidden by an
7718 -- an entity declared in a generic actual, which can only have
7719 -- been use-visible in the generic and will not have hidden the
7720 -- entity in the generic parent.
7722 -- If Id is called Standard, the predefined package with the
7723 -- same name is in the homonym chain. It has to be ignored
7724 -- because it has no defined scope (being the only entity in
7725 -- the system with this mandated behavior).
7727 elsif not Is_Hidden (Id)
7728 and then Present (Scope (Prev))
7729 and then not Is_Wrapper_Package (Scope (Prev))
7730 and then Scope_Depth (Scope (Prev)) <
7731 Scope_Depth (Current_Instance)
7732 and then (Scope (Prev) /= Standard_Standard
7733 or else Sloc (Prev) > Standard_Location)
7735 if In_Open_Scopes (Scope (Prev))
7736 and then Is_Generic_Instance (Scope (Prev))
7737 and then Present (Associated_Formal_Package (P))
7742 Set_Is_Potentially_Use_Visible (Id);
7743 Set_Is_Immediately_Visible (Prev, False);
7744 Append_Elmt (Prev, Hidden_By_Use_Clause (N));
7748 -- A user-defined operator is not use-visible if the predefined
7749 -- operator for the type is immediately visible, which is the case
7750 -- if the type of the operand is in an open scope. This does not
7751 -- apply to user-defined operators that have operands of different
7752 -- types, because the predefined mixed mode operations (multiply
7753 -- and divide) apply to universal types and do not hide anything.
7755 elsif Ekind (Prev) = E_Operator
7756 and then Operator_Matches_Spec (Prev, Id)
7757 and then In_Open_Scopes
7758 (Scope (Base_Type (Etype (First_Formal (Id)))))
7759 and then (No (Next_Formal (First_Formal (Id)))
7760 or else Etype (First_Formal (Id))
7761 = Etype (Next_Formal (First_Formal (Id)))
7762 or else Chars (Prev) = Name_Op_Expon)
7764 goto Next_Usable_Entity;
7766 -- In an instance, two homonyms may become use_visible through the
7767 -- actuals of distinct formal packages. In the generic, only the
7768 -- current one would have been visible, so make the other one
7771 elsif Present (Current_Instance)
7772 and then Is_Potentially_Use_Visible (Prev)
7773 and then not Is_Overloadable (Prev)
7774 and then Scope (Id) /= Scope (Prev)
7775 and then Used_As_Generic_Actual (Scope (Prev))
7776 and then Used_As_Generic_Actual (Scope (Id))
7777 and then not In_Same_List (Current_Use_Clause (Scope (Prev)),
7778 Current_Use_Clause (Scope (Id)))
7780 Set_Is_Potentially_Use_Visible (Prev, False);
7781 Append_Elmt (Prev, Hidden_By_Use_Clause (N));
7784 Prev := Homonym (Prev);
7787 -- On exit, we know entity is not hidden, unless it is private
7789 if not Is_Hidden (Id)
7790 and then ((not Is_Child_Unit (Id))
7791 or else Is_Visible_Child_Unit (Id))
7793 Set_Is_Potentially_Use_Visible (Id);
7795 if Is_Private_Type (Id)
7796 and then Present (Full_View (Id))
7798 Set_Is_Potentially_Use_Visible (Full_View (Id));
7802 <<Next_Usable_Entity>>
7806 -- Child units are also made use-visible by a use clause, but they may
7807 -- appear after all visible declarations in the parent entity list.
7809 while Present (Id) loop
7810 if Is_Child_Unit (Id)
7811 and then Is_Visible_Child_Unit (Id)
7813 Set_Is_Potentially_Use_Visible (Id);
7819 if Chars (Real_P) = Name_System
7820 and then Scope (Real_P) = Standard_Standard
7821 and then Present_System_Aux (N)
7823 Use_One_Package (System_Aux_Id, N);
7826 end Use_One_Package;
7832 procedure Use_One_Type (Id : Node_Id; Installed : Boolean := False) is
7834 Is_Known_Used : Boolean;
7838 function Spec_Reloaded_For_Body return Boolean;
7839 -- Determine whether the compilation unit is a package body and the use
7840 -- type clause is in the spec of the same package. Even though the spec
7841 -- was analyzed first, its context is reloaded when analysing the body.
7843 procedure Use_Class_Wide_Operations (Typ : Entity_Id);
7844 -- AI05-150: if the use_type_clause carries the "all" qualifier,
7845 -- class-wide operations of ancestor types are use-visible if the
7846 -- ancestor type is visible.
7848 ----------------------------
7849 -- Spec_Reloaded_For_Body --
7850 ----------------------------
7852 function Spec_Reloaded_For_Body return Boolean is
7854 if Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Body then
7856 Spec : constant Node_Id :=
7857 Parent (List_Containing (Parent (Id)));
7860 Nkind (Spec) = N_Package_Specification
7861 and then Corresponding_Body (Parent (Spec)) =
7862 Cunit_Entity (Current_Sem_Unit);
7867 end Spec_Reloaded_For_Body;
7869 -------------------------------
7870 -- Use_Class_Wide_Operations --
7871 -------------------------------
7873 procedure Use_Class_Wide_Operations (Typ : Entity_Id) is
7877 function Is_Class_Wide_Operation_Of
7879 T : Entity_Id) return Boolean;
7880 -- Determine whether a subprogram has a class-wide parameter or
7881 -- result that is T'Class.
7883 ---------------------------------
7884 -- Is_Class_Wide_Operation_Of --
7885 ---------------------------------
7887 function Is_Class_Wide_Operation_Of
7889 T : Entity_Id) return Boolean
7894 Formal := First_Formal (Op);
7895 while Present (Formal) loop
7896 if Etype (Formal) = Class_Wide_Type (T) then
7899 Next_Formal (Formal);
7902 if Etype (Op) = Class_Wide_Type (T) then
7907 end Is_Class_Wide_Operation_Of;
7909 -- Start of processing for Use_Class_Wide_Operations
7912 Scop := Scope (Typ);
7913 if not Is_Hidden (Scop) then
7914 Ent := First_Entity (Scop);
7915 while Present (Ent) loop
7916 if Is_Overloadable (Ent)
7917 and then Is_Class_Wide_Operation_Of (Ent, Typ)
7918 and then not Is_Potentially_Use_Visible (Ent)
7920 Set_Is_Potentially_Use_Visible (Ent);
7921 Append_Elmt (Ent, Used_Operations (Parent (Id)));
7928 if Is_Derived_Type (Typ) then
7929 Use_Class_Wide_Operations (Etype (Base_Type (Typ)));
7931 end Use_Class_Wide_Operations;
7933 -- Start of processing for Use_One_Type;
7936 -- It is the type determined by the subtype mark (8.4(8)) whose
7937 -- operations become potentially use-visible.
7939 T := Base_Type (Entity (Id));
7941 -- Either the type itself is used, the package where it is declared
7942 -- is in use or the entity is declared in the current package, thus
7947 or else In_Use (Scope (T))
7948 or else Scope (T) = Current_Scope;
7950 Set_Redundant_Use (Id,
7951 Is_Known_Used or else Is_Potentially_Use_Visible (T));
7953 if Ekind (T) = E_Incomplete_Type then
7954 Error_Msg_N ("premature usage of incomplete type", Id);
7956 elsif In_Open_Scopes (Scope (T)) then
7959 -- A limited view cannot appear in a use_type clause. However, an access
7960 -- type whose designated type is limited has the flag but is not itself
7961 -- a limited view unless we only have a limited view of its enclosing
7964 elsif From_With_Type (T)
7965 and then From_With_Type (Scope (T))
7968 ("incomplete type from limited view "
7969 & "cannot appear in use clause", Id);
7971 -- If the subtype mark designates a subtype in a different package,
7972 -- we have to check that the parent type is visible, otherwise the
7973 -- use type clause is a noop. Not clear how to do that???
7975 elsif not Redundant_Use (Id) then
7978 -- If T is tagged, primitive operators on class-wide operands
7979 -- are also available.
7981 if Is_Tagged_Type (T) then
7982 Set_In_Use (Class_Wide_Type (T));
7985 Set_Current_Use_Clause (T, Parent (Id));
7987 -- Iterate over primitive operations of the type. If an operation is
7988 -- already use_visible, it is the result of a previous use_clause,
7989 -- and already appears on the corresponding entity chain. If the
7990 -- clause is being reinstalled, operations are already use-visible.
7996 Op_List := Collect_Primitive_Operations (T);
7997 Elmt := First_Elmt (Op_List);
7998 while Present (Elmt) loop
7999 if (Nkind (Node (Elmt)) = N_Defining_Operator_Symbol
8000 or else Chars (Node (Elmt)) in Any_Operator_Name)
8001 and then not Is_Hidden (Node (Elmt))
8002 and then not Is_Potentially_Use_Visible (Node (Elmt))
8004 Set_Is_Potentially_Use_Visible (Node (Elmt));
8005 Append_Elmt (Node (Elmt), Used_Operations (Parent (Id)));
8007 elsif Ada_Version >= Ada_2012
8008 and then All_Present (Parent (Id))
8009 and then not Is_Hidden (Node (Elmt))
8010 and then not Is_Potentially_Use_Visible (Node (Elmt))
8012 Set_Is_Potentially_Use_Visible (Node (Elmt));
8013 Append_Elmt (Node (Elmt), Used_Operations (Parent (Id)));
8020 if Ada_Version >= Ada_2012
8021 and then All_Present (Parent (Id))
8022 and then Is_Tagged_Type (T)
8024 Use_Class_Wide_Operations (T);
8028 -- If warning on redundant constructs, check for unnecessary WITH
8030 if Warn_On_Redundant_Constructs
8031 and then Is_Known_Used
8033 -- with P; with P; use P;
8034 -- package P is package X is package body X is
8035 -- type T ... use P.T;
8037 -- The compilation unit is the body of X. GNAT first compiles the
8038 -- spec of X, then proceeds to the body. At that point P is marked
8039 -- as use visible. The analysis then reinstalls the spec along with
8040 -- its context. The use clause P.T is now recognized as redundant,
8041 -- but in the wrong context. Do not emit a warning in such cases.
8042 -- Do not emit a warning either if we are in an instance, there is
8043 -- no redundancy between an outer use_clause and one that appears
8044 -- within the generic.
8046 and then not Spec_Reloaded_For_Body
8047 and then not In_Instance
8049 -- The type already has a use clause
8053 -- Case where we know the current use clause for the type
8055 if Present (Current_Use_Clause (T)) then
8056 Use_Clause_Known : declare
8057 Clause1 : constant Node_Id := Parent (Id);
8058 Clause2 : constant Node_Id := Current_Use_Clause (T);
8065 function Entity_Of_Unit (U : Node_Id) return Entity_Id;
8066 -- Return the appropriate entity for determining which unit
8067 -- has a deeper scope: the defining entity for U, unless U
8068 -- is a package instance, in which case we retrieve the
8069 -- entity of the instance spec.
8071 --------------------
8072 -- Entity_Of_Unit --
8073 --------------------
8075 function Entity_Of_Unit (U : Node_Id) return Entity_Id is
8077 if Nkind (U) = N_Package_Instantiation
8078 and then Analyzed (U)
8080 return Defining_Entity (Instance_Spec (U));
8082 return Defining_Entity (U);
8086 -- Start of processing for Use_Clause_Known
8089 -- If both current use type clause and the use type clause
8090 -- for the type are at the compilation unit level, one of
8091 -- the units must be an ancestor of the other, and the
8092 -- warning belongs on the descendant.
8094 if Nkind (Parent (Clause1)) = N_Compilation_Unit
8096 Nkind (Parent (Clause2)) = N_Compilation_Unit
8099 -- If the unit is a subprogram body that acts as spec,
8100 -- the context clause is shared with the constructed
8101 -- subprogram spec. Clearly there is no redundancy.
8103 if Clause1 = Clause2 then
8107 Unit1 := Unit (Parent (Clause1));
8108 Unit2 := Unit (Parent (Clause2));
8110 -- If both clauses are on same unit, or one is the body
8111 -- of the other, or one of them is in a subunit, report
8112 -- redundancy on the later one.
8114 if Unit1 = Unit2 then
8115 Error_Msg_Sloc := Sloc (Current_Use_Clause (T));
8116 Error_Msg_NE -- CODEFIX
8117 ("& is already use-visible through previous "
8118 & "use_type_clause #?", Clause1, T);
8121 elsif Nkind (Unit1) = N_Subunit then
8122 Error_Msg_Sloc := Sloc (Current_Use_Clause (T));
8123 Error_Msg_NE -- CODEFIX
8124 ("& is already use-visible through previous "
8125 & "use_type_clause #?", Clause1, T);
8128 elsif Nkind_In (Unit2, N_Package_Body, N_Subprogram_Body)
8129 and then Nkind (Unit1) /= Nkind (Unit2)
8130 and then Nkind (Unit1) /= N_Subunit
8132 Error_Msg_Sloc := Sloc (Clause1);
8133 Error_Msg_NE -- CODEFIX
8134 ("& is already use-visible through previous "
8135 & "use_type_clause #?", Current_Use_Clause (T), T);
8139 -- There is a redundant use type clause in a child unit.
8140 -- Determine which of the units is more deeply nested.
8141 -- If a unit is a package instance, retrieve the entity
8142 -- and its scope from the instance spec.
8144 Ent1 := Entity_Of_Unit (Unit1);
8145 Ent2 := Entity_Of_Unit (Unit2);
8147 if Scope (Ent2) = Standard_Standard then
8148 Error_Msg_Sloc := Sloc (Current_Use_Clause (T));
8151 elsif Scope (Ent1) = Standard_Standard then
8152 Error_Msg_Sloc := Sloc (Id);
8155 -- If both units are child units, we determine which one
8156 -- is the descendant by the scope distance to the
8157 -- ultimate parent unit.
8167 and then Present (S2)
8168 and then S1 /= Standard_Standard
8169 and then S2 /= Standard_Standard
8175 if S1 = Standard_Standard then
8176 Error_Msg_Sloc := Sloc (Id);
8179 Error_Msg_Sloc := Sloc (Current_Use_Clause (T));
8185 Error_Msg_NE -- CODEFIX
8186 ("& is already use-visible through previous "
8187 & "use_type_clause #?", Err_No, Id);
8189 -- Case where current use type clause and the use type
8190 -- clause for the type are not both at the compilation unit
8191 -- level. In this case we don't have location information.
8194 Error_Msg_NE -- CODEFIX
8195 ("& is already use-visible through previous "
8196 & "use type clause?", Id, T);
8198 end Use_Clause_Known;
8200 -- Here if Current_Use_Clause is not set for T, another case
8201 -- where we do not have the location information available.
8204 Error_Msg_NE -- CODEFIX
8205 ("& is already use-visible through previous "
8206 & "use type clause?", Id, T);
8209 -- The package where T is declared is already used
8211 elsif In_Use (Scope (T)) then
8212 Error_Msg_Sloc := Sloc (Current_Use_Clause (Scope (T)));
8213 Error_Msg_NE -- CODEFIX
8214 ("& is already use-visible through package use clause #?",
8217 -- The current scope is the package where T is declared
8220 Error_Msg_Node_2 := Scope (T);
8221 Error_Msg_NE -- CODEFIX
8222 ("& is already use-visible inside package &?", Id, T);
8231 procedure Write_Info is
8232 Id : Entity_Id := First_Entity (Current_Scope);
8235 -- No point in dumping standard entities
8237 if Current_Scope = Standard_Standard then
8241 Write_Str ("========================================================");
8243 Write_Str (" Defined Entities in ");
8244 Write_Name (Chars (Current_Scope));
8246 Write_Str ("========================================================");
8250 Write_Str ("-- none --");
8254 while Present (Id) loop
8255 Write_Entity_Info (Id, " ");
8260 if Scope (Current_Scope) = Standard_Standard then
8262 -- Print information on the current unit itself
8264 Write_Entity_Info (Current_Scope, " ");
8277 for J in reverse 1 .. Scope_Stack.Last loop
8278 S := Scope_Stack.Table (J).Entity;
8279 Write_Int (Int (S));
8280 Write_Str (" === ");
8281 Write_Name (Chars (S));
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