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))
724 -- A renaming of an unchecked union does not have an
727 elsif Is_Unchecked_Union (Etype (Nam)) then
731 Subt := Make_Temporary (Loc, 'T');
732 Remove_Side_Effects (Nam);
734 Make_Subtype_Declaration (Loc,
735 Defining_Identifier => Subt,
736 Subtype_Indication =>
737 Make_Subtype_From_Expr (Nam, Etype (Nam))));
738 Rewrite (Subtype_Mark (N), New_Occurrence_Of (Subt, Loc));
739 Set_Etype (Nam, Subt);
742 end Check_Constrained_Object;
744 ----------------------
745 -- In_Generic_Scope --
746 ----------------------
748 function In_Generic_Scope (E : Entity_Id) return Boolean is
753 while Present (S) and then S /= Standard_Standard loop
754 if Is_Generic_Unit (S) then
762 end In_Generic_Scope;
764 -- Start of processing for Analyze_Object_Renaming
771 Check_SPARK_Restriction ("object renaming is not allowed", N);
773 Set_Is_Pure (Id, Is_Pure (Current_Scope));
776 -- The renaming of a component that depends on a discriminant requires
777 -- an actual subtype, because in subsequent use of the object Gigi will
778 -- be unable to locate the actual bounds. This explicit step is required
779 -- when the renaming is generated in removing side effects of an
780 -- already-analyzed expression.
782 if Nkind (Nam) = N_Selected_Component
783 and then Analyzed (Nam)
786 Dec := Build_Actual_Subtype_Of_Component (Etype (Nam), Nam);
788 if Present (Dec) then
789 Insert_Action (N, Dec);
790 T := Defining_Identifier (Dec);
794 -- Complete analysis of the subtype mark in any case, for ASIS use
796 if Present (Subtype_Mark (N)) then
797 Find_Type (Subtype_Mark (N));
800 elsif Present (Subtype_Mark (N)) then
801 Find_Type (Subtype_Mark (N));
802 T := Entity (Subtype_Mark (N));
805 if Nkind (Nam) = N_Type_Conversion
806 and then not Is_Tagged_Type (T)
809 ("renaming of conversion only allowed for tagged types", Nam);
814 -- If the renamed object is a function call of a limited type,
815 -- the expansion of the renaming is complicated by the presence
816 -- of various temporaries and subtypes that capture constraints
817 -- of the renamed object. Rewrite node as an object declaration,
818 -- whose expansion is simpler. Given that the object is limited
819 -- there is no copy involved and no performance hit.
821 if Nkind (Nam) = N_Function_Call
822 and then Is_Immutably_Limited_Type (Etype (Nam))
823 and then not Is_Constrained (Etype (Nam))
824 and then Comes_From_Source (N)
827 Set_Ekind (Id, E_Constant);
829 Make_Object_Declaration (Loc,
830 Defining_Identifier => Id,
831 Constant_Present => True,
832 Object_Definition => New_Occurrence_Of (Etype (Nam), Loc),
833 Expression => Relocate_Node (Nam)));
837 -- Check that a class-wide object is not being renamed as an object
838 -- of a specific type. The test for access types is needed to exclude
839 -- cases where the renamed object is a dynamically tagged access
840 -- result, such as occurs in certain expansions.
842 if Is_Tagged_Type (T) then
843 Check_Dynamically_Tagged_Expression
849 -- Ada 2005 (AI-230/AI-254): Access renaming
851 else pragma Assert (Present (Access_Definition (N)));
852 T := Access_Definition
854 N => Access_Definition (N));
858 -- Ada 2005 AI05-105: if the declaration has an anonymous access
859 -- type, the renamed object must also have an anonymous type, and
860 -- this is a name resolution rule. This was implicit in the last part
861 -- of the first sentence in 8.5.1(3/2), and is made explicit by this
864 if not Is_Overloaded (Nam) then
865 if Ekind (Etype (Nam)) /= Ekind (T) then
867 ("expect anonymous access type in object renaming", N);
874 Typ : Entity_Id := Empty;
875 Seen : Boolean := False;
878 Get_First_Interp (Nam, I, It);
879 while Present (It.Typ) loop
881 -- Renaming is ambiguous if more than one candidate
882 -- interpretation is type-conformant with the context.
884 if Ekind (It.Typ) = Ekind (T) then
885 if Ekind (T) = E_Anonymous_Access_Subprogram_Type
888 (Designated_Type (T), Designated_Type (It.Typ))
894 ("ambiguous expression in renaming", Nam);
897 elsif Ekind (T) = E_Anonymous_Access_Type
899 Covers (Designated_Type (T), Designated_Type (It.Typ))
905 ("ambiguous expression in renaming", Nam);
909 if Covers (T, It.Typ) then
911 Set_Etype (Nam, Typ);
912 Set_Is_Overloaded (Nam, False);
916 Get_Next_Interp (I, It);
923 -- Ada 2005 (AI-231): "In the case where the type is defined by an
924 -- access_definition, the renamed entity shall be of an access-to-
925 -- constant type if and only if the access_definition defines an
926 -- access-to-constant type" ARM 8.5.1(4)
928 if Constant_Present (Access_Definition (N))
929 and then not Is_Access_Constant (Etype (Nam))
931 Error_Msg_N ("(Ada 2005): the renamed object is not "
932 & "access-to-constant (RM 8.5.1(6))", N);
934 elsif not Constant_Present (Access_Definition (N))
935 and then Is_Access_Constant (Etype (Nam))
937 Error_Msg_N ("(Ada 2005): the renamed object is not "
938 & "access-to-variable (RM 8.5.1(6))", N);
941 if Is_Access_Subprogram_Type (Etype (Nam)) then
942 Check_Subtype_Conformant
943 (Designated_Type (T), Designated_Type (Etype (Nam)));
945 elsif not Subtypes_Statically_Match
946 (Designated_Type (T),
947 Available_View (Designated_Type (Etype (Nam))))
950 ("subtype of renamed object does not statically match", N);
954 -- Special processing for renaming function return object. Some errors
955 -- and warnings are produced only for calls that come from source.
957 if Nkind (Nam) = N_Function_Call then
960 -- Usage is illegal in Ada 83
963 if Comes_From_Source (Nam) then
965 ("(Ada 83) cannot rename function return object", Nam);
968 -- In Ada 95, warn for odd case of renaming parameterless function
969 -- call if this is not a limited type (where this is useful).
972 if Warn_On_Object_Renames_Function
973 and then No (Parameter_Associations (Nam))
974 and then not Is_Limited_Type (Etype (Nam))
975 and then Comes_From_Source (Nam)
978 ("?renaming function result object is suspicious", Nam);
980 ("\?function & will be called only once", Nam,
981 Entity (Name (Nam)));
982 Error_Msg_N -- CODEFIX
983 ("\?suggest using an initialized constant object instead",
990 Check_Constrained_Object;
992 -- An object renaming requires an exact match of the type. Class-wide
993 -- matching is not allowed.
995 if Is_Class_Wide_Type (T)
996 and then Base_Type (Etype (Nam)) /= Base_Type (T)
1003 -- Ada 2005 (AI-326): Handle wrong use of incomplete type
1005 if Nkind (Nam) = N_Explicit_Dereference
1006 and then Ekind (Etype (T2)) = E_Incomplete_Type
1008 Error_Msg_NE ("invalid use of incomplete type&", Id, T2);
1011 elsif Ekind (Etype (T)) = E_Incomplete_Type then
1012 Error_Msg_NE ("invalid use of incomplete type&", Id, T);
1016 -- Ada 2005 (AI-327)
1018 if Ada_Version >= Ada_2005
1019 and then Nkind (Nam) = N_Attribute_Reference
1020 and then Attribute_Name (Nam) = Name_Priority
1024 elsif Ada_Version >= Ada_2005
1025 and then Nkind (Nam) in N_Has_Entity
1029 Nam_Ent : Entity_Id;
1032 if Nkind (Nam) = N_Attribute_Reference then
1033 Nam_Ent := Entity (Prefix (Nam));
1035 Nam_Ent := Entity (Nam);
1038 Nam_Decl := Parent (Nam_Ent);
1040 if Has_Null_Exclusion (N)
1041 and then not Has_Null_Exclusion (Nam_Decl)
1043 -- Ada 2005 (AI-423): If the object name denotes a generic
1044 -- formal object of a generic unit G, and the object renaming
1045 -- declaration occurs within the body of G or within the body
1046 -- of a generic unit declared within the declarative region
1047 -- of G, then the declaration of the formal object of G must
1048 -- have a null exclusion or a null-excluding subtype.
1050 if Is_Formal_Object (Nam_Ent)
1051 and then In_Generic_Scope (Id)
1053 if not Can_Never_Be_Null (Etype (Nam_Ent)) then
1055 ("renamed formal does not exclude `NULL` "
1056 & "(RM 8.5.1(4.6/2))", N);
1058 elsif In_Package_Body (Scope (Id)) then
1060 ("formal object does not have a null exclusion"
1061 & "(RM 8.5.1(4.6/2))", N);
1064 -- Ada 2005 (AI-423): Otherwise, the subtype of the object name
1065 -- shall exclude null.
1067 elsif not Can_Never_Be_Null (Etype (Nam_Ent)) then
1069 ("renamed object does not exclude `NULL` "
1070 & "(RM 8.5.1(4.6/2))", N);
1072 -- An instance is illegal if it contains a renaming that
1073 -- excludes null, and the actual does not. The renaming
1074 -- declaration has already indicated that the declaration
1075 -- of the renamed actual in the instance will raise
1076 -- constraint_error.
1078 elsif Nkind (Nam_Decl) = N_Object_Declaration
1079 and then In_Instance
1081 (Corresponding_Generic_Association (Nam_Decl))
1082 and then Nkind (Expression (Nam_Decl))
1083 = N_Raise_Constraint_Error
1086 ("renamed actual does not exclude `NULL` "
1087 & "(RM 8.5.1(4.6/2))", N);
1089 -- Finally, if there is a null exclusion, the subtype mark
1090 -- must not be null-excluding.
1092 elsif No (Access_Definition (N))
1093 and then Can_Never_Be_Null (T)
1096 ("`NOT NULL` not allowed (& already excludes null)",
1101 elsif Can_Never_Be_Null (T)
1102 and then not Can_Never_Be_Null (Etype (Nam_Ent))
1105 ("renamed object does not exclude `NULL` "
1106 & "(RM 8.5.1(4.6/2))", N);
1108 elsif Has_Null_Exclusion (N)
1109 and then No (Access_Definition (N))
1110 and then Can_Never_Be_Null (T)
1113 ("`NOT NULL` not allowed (& already excludes null)", N, T);
1118 Set_Ekind (Id, E_Variable);
1119 Init_Size_Align (Id);
1121 if T = Any_Type or else Etype (Nam) = Any_Type then
1124 -- Verify that the renamed entity is an object or a function call. It
1125 -- may have been rewritten in several ways.
1127 elsif Is_Object_Reference (Nam) then
1128 if Comes_From_Source (N)
1129 and then Is_Dependent_Component_Of_Mutable_Object (Nam)
1132 ("illegal renaming of discriminant-dependent component", Nam);
1135 -- A static function call may have been folded into a literal
1137 elsif Nkind (Original_Node (Nam)) = N_Function_Call
1139 -- When expansion is disabled, attribute reference is not
1140 -- rewritten as function call. Otherwise it may be rewritten
1141 -- as a conversion, so check original node.
1143 or else (Nkind (Original_Node (Nam)) = N_Attribute_Reference
1144 and then Is_Function_Attribute_Name
1145 (Attribute_Name (Original_Node (Nam))))
1147 -- Weird but legal, equivalent to renaming a function call.
1148 -- Illegal if the literal is the result of constant-folding an
1149 -- attribute reference that is not a function.
1151 or else (Is_Entity_Name (Nam)
1152 and then Ekind (Entity (Nam)) = E_Enumeration_Literal
1154 Nkind (Original_Node (Nam)) /= N_Attribute_Reference)
1156 or else (Nkind (Nam) = N_Type_Conversion
1157 and then Is_Tagged_Type (Entity (Subtype_Mark (Nam))))
1161 elsif Nkind (Nam) = N_Type_Conversion then
1163 ("renaming of conversion only allowed for tagged types", Nam);
1165 -- Ada 2005 (AI-327)
1167 elsif Ada_Version >= Ada_2005
1168 and then Nkind (Nam) = N_Attribute_Reference
1169 and then Attribute_Name (Nam) = Name_Priority
1173 -- Allow internally generated x'Reference expression
1175 elsif Nkind (Nam) = N_Reference then
1179 Error_Msg_N ("expect object name in renaming", Nam);
1184 if not Is_Variable (Nam) then
1185 Set_Ekind (Id, E_Constant);
1186 Set_Never_Set_In_Source (Id, True);
1187 Set_Is_True_Constant (Id, True);
1190 Set_Renamed_Object (Id, Nam);
1191 end Analyze_Object_Renaming;
1193 ------------------------------
1194 -- Analyze_Package_Renaming --
1195 ------------------------------
1197 procedure Analyze_Package_Renaming (N : Node_Id) is
1198 New_P : constant Entity_Id := Defining_Entity (N);
1203 if Name (N) = Error then
1207 -- Apply Text_IO kludge here since we may be renaming a child of Text_IO
1209 Text_IO_Kludge (Name (N));
1211 if Current_Scope /= Standard_Standard then
1212 Set_Is_Pure (New_P, Is_Pure (Current_Scope));
1218 if Is_Entity_Name (Name (N)) then
1219 Old_P := Entity (Name (N));
1224 if Etype (Old_P) = Any_Type then
1225 Error_Msg_N ("expect package name in renaming", Name (N));
1227 elsif Ekind (Old_P) /= E_Package
1228 and then not (Ekind (Old_P) = E_Generic_Package
1229 and then In_Open_Scopes (Old_P))
1231 if Ekind (Old_P) = E_Generic_Package then
1233 ("generic package cannot be renamed as a package", Name (N));
1235 Error_Msg_Sloc := Sloc (Old_P);
1237 ("expect package name in renaming, found& declared#",
1241 -- Set basic attributes to minimize cascaded errors
1243 Set_Ekind (New_P, E_Package);
1244 Set_Etype (New_P, Standard_Void_Type);
1246 -- Here for OK package renaming
1249 -- Entities in the old package are accessible through the renaming
1250 -- entity. The simplest implementation is to have both packages share
1253 Set_Ekind (New_P, E_Package);
1254 Set_Etype (New_P, Standard_Void_Type);
1256 if Present (Renamed_Object (Old_P)) then
1257 Set_Renamed_Object (New_P, Renamed_Object (Old_P));
1259 Set_Renamed_Object (New_P, Old_P);
1262 Set_Has_Completion (New_P);
1264 Set_First_Entity (New_P, First_Entity (Old_P));
1265 Set_Last_Entity (New_P, Last_Entity (Old_P));
1266 Set_First_Private_Entity (New_P, First_Private_Entity (Old_P));
1267 Check_Library_Unit_Renaming (N, Old_P);
1268 Generate_Reference (Old_P, Name (N));
1270 -- If the renaming is in the visible part of a package, then we set
1271 -- Renamed_In_Spec for the renamed package, to prevent giving
1272 -- warnings about no entities referenced. Such a warning would be
1273 -- overenthusiastic, since clients can see entities in the renamed
1274 -- package via the visible package renaming.
1277 Ent : constant Entity_Id := Cunit_Entity (Current_Sem_Unit);
1279 if Ekind (Ent) = E_Package
1280 and then not In_Private_Part (Ent)
1281 and then In_Extended_Main_Source_Unit (N)
1282 and then Ekind (Old_P) = E_Package
1284 Set_Renamed_In_Spec (Old_P);
1288 -- If this is the renaming declaration of a package instantiation
1289 -- within itself, it is the declaration that ends the list of actuals
1290 -- for the instantiation. At this point, the subtypes that rename
1291 -- the actuals are flagged as generic, to avoid spurious ambiguities
1292 -- if the actuals for two distinct formals happen to coincide. If
1293 -- the actual is a private type, the subtype has a private completion
1294 -- that is flagged in the same fashion.
1296 -- Resolution is identical to what is was in the original generic.
1297 -- On exit from the generic instance, these are turned into regular
1298 -- subtypes again, so they are compatible with types in their class.
1300 if not Is_Generic_Instance (Old_P) then
1303 Spec := Specification (Unit_Declaration_Node (Old_P));
1306 if Nkind (Spec) = N_Package_Specification
1307 and then Present (Generic_Parent (Spec))
1308 and then Old_P = Current_Scope
1309 and then Chars (New_P) = Chars (Generic_Parent (Spec))
1315 E := First_Entity (Old_P);
1320 and then Nkind (Parent (E)) = N_Subtype_Declaration
1322 Set_Is_Generic_Actual_Type (E);
1324 if Is_Private_Type (E)
1325 and then Present (Full_View (E))
1327 Set_Is_Generic_Actual_Type (Full_View (E));
1336 end Analyze_Package_Renaming;
1338 -------------------------------
1339 -- Analyze_Renamed_Character --
1340 -------------------------------
1342 procedure Analyze_Renamed_Character
1347 C : constant Node_Id := Name (N);
1350 if Ekind (New_S) = E_Function then
1351 Resolve (C, Etype (New_S));
1354 Check_Frozen_Renaming (N, New_S);
1358 Error_Msg_N ("character literal can only be renamed as function", N);
1360 end Analyze_Renamed_Character;
1362 ---------------------------------
1363 -- Analyze_Renamed_Dereference --
1364 ---------------------------------
1366 procedure Analyze_Renamed_Dereference
1371 Nam : constant Node_Id := Name (N);
1372 P : constant Node_Id := Prefix (Nam);
1378 if not Is_Overloaded (P) then
1379 if Ekind (Etype (Nam)) /= E_Subprogram_Type
1380 or else not Type_Conformant (Etype (Nam), New_S)
1382 Error_Msg_N ("designated type does not match specification", P);
1391 Get_First_Interp (Nam, Ind, It);
1393 while Present (It.Nam) loop
1395 if Ekind (It.Nam) = E_Subprogram_Type
1396 and then Type_Conformant (It.Nam, New_S)
1398 if Typ /= Any_Id then
1399 Error_Msg_N ("ambiguous renaming", P);
1406 Get_Next_Interp (Ind, It);
1409 if Typ = Any_Type then
1410 Error_Msg_N ("designated type does not match specification", P);
1415 Check_Frozen_Renaming (N, New_S);
1419 end Analyze_Renamed_Dereference;
1421 ---------------------------
1422 -- Analyze_Renamed_Entry --
1423 ---------------------------
1425 procedure Analyze_Renamed_Entry
1430 Nam : constant Node_Id := Name (N);
1431 Sel : constant Node_Id := Selector_Name (Nam);
1435 if Entity (Sel) = Any_Id then
1437 -- Selector is undefined on prefix. Error emitted already
1439 Set_Has_Completion (New_S);
1443 -- Otherwise find renamed entity and build body of New_S as a call to it
1445 Old_S := Find_Renamed_Entity (N, Selector_Name (Nam), New_S);
1447 if Old_S = Any_Id then
1448 Error_Msg_N (" no subprogram or entry matches specification", N);
1451 Check_Subtype_Conformant (New_S, Old_S, N);
1452 Generate_Reference (New_S, Defining_Entity (N), 'b');
1453 Style.Check_Identifier (Defining_Entity (N), New_S);
1456 -- Only mode conformance required for a renaming_as_declaration
1458 Check_Mode_Conformant (New_S, Old_S, N);
1461 Inherit_Renamed_Profile (New_S, Old_S);
1463 -- The prefix can be an arbitrary expression that yields a task type,
1464 -- so it must be resolved.
1466 Resolve (Prefix (Nam), Scope (Old_S));
1469 Set_Convention (New_S, Convention (Old_S));
1470 Set_Has_Completion (New_S, Inside_A_Generic);
1473 Check_Frozen_Renaming (N, New_S);
1475 end Analyze_Renamed_Entry;
1477 -----------------------------------
1478 -- Analyze_Renamed_Family_Member --
1479 -----------------------------------
1481 procedure Analyze_Renamed_Family_Member
1486 Nam : constant Node_Id := Name (N);
1487 P : constant Node_Id := Prefix (Nam);
1491 if (Is_Entity_Name (P) and then Ekind (Entity (P)) = E_Entry_Family)
1492 or else (Nkind (P) = N_Selected_Component
1494 Ekind (Entity (Selector_Name (P))) = E_Entry_Family)
1496 if Is_Entity_Name (P) then
1497 Old_S := Entity (P);
1499 Old_S := Entity (Selector_Name (P));
1502 if not Entity_Matches_Spec (Old_S, New_S) then
1503 Error_Msg_N ("entry family does not match specification", N);
1506 Check_Subtype_Conformant (New_S, Old_S, N);
1507 Generate_Reference (New_S, Defining_Entity (N), 'b');
1508 Style.Check_Identifier (Defining_Entity (N), New_S);
1512 Error_Msg_N ("no entry family matches specification", N);
1515 Set_Has_Completion (New_S, Inside_A_Generic);
1518 Check_Frozen_Renaming (N, New_S);
1520 end Analyze_Renamed_Family_Member;
1522 -----------------------------------------
1523 -- Analyze_Renamed_Primitive_Operation --
1524 -----------------------------------------
1526 procedure Analyze_Renamed_Primitive_Operation
1535 Ctyp : Conformance_Type) return Boolean;
1536 -- Verify that the signatures of the renamed entity and the new entity
1537 -- match. The first formal of the renamed entity is skipped because it
1538 -- is the target object in any subsequent call.
1542 Ctyp : Conformance_Type) return Boolean
1548 if Ekind (Subp) /= Ekind (New_S) then
1552 Old_F := Next_Formal (First_Formal (Subp));
1553 New_F := First_Formal (New_S);
1554 while Present (Old_F) and then Present (New_F) loop
1555 if not Conforming_Types (Etype (Old_F), Etype (New_F), Ctyp) then
1559 if Ctyp >= Mode_Conformant
1560 and then Ekind (Old_F) /= Ekind (New_F)
1565 Next_Formal (New_F);
1566 Next_Formal (Old_F);
1573 if not Is_Overloaded (Selector_Name (Name (N))) then
1574 Old_S := Entity (Selector_Name (Name (N)));
1576 if not Conforms (Old_S, Type_Conformant) then
1581 -- Find the operation that matches the given signature
1589 Get_First_Interp (Selector_Name (Name (N)), Ind, It);
1591 while Present (It.Nam) loop
1592 if Conforms (It.Nam, Type_Conformant) then
1596 Get_Next_Interp (Ind, It);
1601 if Old_S = Any_Id then
1602 Error_Msg_N (" no subprogram or entry matches specification", N);
1606 if not Conforms (Old_S, Subtype_Conformant) then
1607 Error_Msg_N ("subtype conformance error in renaming", N);
1610 Generate_Reference (New_S, Defining_Entity (N), 'b');
1611 Style.Check_Identifier (Defining_Entity (N), New_S);
1614 -- Only mode conformance required for a renaming_as_declaration
1616 if not Conforms (Old_S, Mode_Conformant) then
1617 Error_Msg_N ("mode conformance error in renaming", N);
1621 -- Inherit_Renamed_Profile (New_S, Old_S);
1623 -- The prefix can be an arbitrary expression that yields an
1624 -- object, so it must be resolved.
1626 Resolve (Prefix (Name (N)));
1628 end Analyze_Renamed_Primitive_Operation;
1630 ---------------------------------
1631 -- Analyze_Subprogram_Renaming --
1632 ---------------------------------
1634 procedure Analyze_Subprogram_Renaming (N : Node_Id) is
1635 Formal_Spec : constant Node_Id := Corresponding_Formal_Spec (N);
1636 Is_Actual : constant Boolean := Present (Formal_Spec);
1637 Inst_Node : Node_Id := Empty;
1638 Nam : constant Node_Id := Name (N);
1640 Old_S : Entity_Id := Empty;
1641 Rename_Spec : Entity_Id;
1642 Save_AV : constant Ada_Version_Type := Ada_Version;
1643 Save_AV_Exp : constant Ada_Version_Type := Ada_Version_Explicit;
1644 Spec : constant Node_Id := Specification (N);
1646 procedure Check_Null_Exclusion
1649 -- Ada 2005 (AI-423): Given renaming Ren of subprogram Sub, check the
1650 -- following AI rules:
1652 -- If Ren is a renaming of a formal subprogram and one of its
1653 -- parameters has a null exclusion, then the corresponding formal
1654 -- in Sub must also have one. Otherwise the subtype of the Sub's
1655 -- formal parameter must exclude null.
1657 -- If Ren is a renaming of a formal function and its return
1658 -- profile has a null exclusion, then Sub's return profile must
1659 -- have one. Otherwise the subtype of Sub's return profile must
1662 function Original_Subprogram (Subp : Entity_Id) return Entity_Id;
1663 -- Find renamed entity when the declaration is a renaming_as_body and
1664 -- the renamed entity may itself be a renaming_as_body. Used to enforce
1665 -- rule that a renaming_as_body is illegal if the declaration occurs
1666 -- before the subprogram it completes is frozen, and renaming indirectly
1667 -- renames the subprogram itself.(Defect Report 8652/0027).
1669 function Check_Class_Wide_Actual return Entity_Id;
1670 -- AI05-0071: In an instance, if the actual for a formal type FT with
1671 -- unknown discriminants is a class-wide type CT, and the generic has
1672 -- a formal subprogram with a box for a primitive operation of FT,
1673 -- then the corresponding actual subprogram denoted by the default is a
1674 -- class-wide operation whose body is a dispatching call. We replace the
1675 -- generated renaming declaration:
1677 -- procedure P (X : CT) renames P;
1679 -- by a different renaming and a class-wide operation:
1681 -- procedure Pr (X : T) renames P; -- renames primitive operation
1682 -- procedure P (X : CT); -- class-wide operation
1684 -- procedure P (X : CT) is begin Pr (X); end; -- dispatching call
1686 -- This rule only applies if there is no explicit visible class-wide
1687 -- operation at the point of the instantiation.
1689 function Has_Class_Wide_Actual return Boolean;
1690 -- Ada 2012 (AI05-071, AI05-0131): True if N is the renaming for a
1691 -- defaulted formal subprogram when the actual for the controlling
1692 -- formal type is class-wide.
1694 -----------------------------
1695 -- Check_Class_Wide_Actual --
1696 -----------------------------
1698 function Check_Class_Wide_Actual return Entity_Id is
1699 Loc : constant Source_Ptr := Sloc (N);
1702 Formal_Type : Entity_Id;
1703 Actual_Type : Entity_Id;
1708 function Make_Call (Prim_Op : Entity_Id) return Node_Id;
1709 -- Build dispatching call for body of class-wide operation
1711 function Make_Spec return Node_Id;
1712 -- Create subprogram specification for declaration and body of
1713 -- class-wide operation, using signature of renaming declaration.
1719 function Make_Call (Prim_Op : Entity_Id) return Node_Id is
1724 Actuals := New_List;
1725 F := First (Parameter_Specifications (Specification (New_Decl)));
1726 while Present (F) loop
1728 Make_Identifier (Loc, Chars (Defining_Identifier (F))));
1732 if Ekind_In (Prim_Op, E_Function, E_Operator) then
1733 return Make_Simple_Return_Statement (Loc,
1735 Make_Function_Call (Loc,
1736 Name => New_Occurrence_Of (Prim_Op, Loc),
1737 Parameter_Associations => Actuals));
1740 Make_Procedure_Call_Statement (Loc,
1741 Name => New_Occurrence_Of (Prim_Op, Loc),
1742 Parameter_Associations => Actuals);
1750 function Make_Spec return Node_Id is
1751 Param_Specs : constant List_Id := Copy_Parameter_List (New_S);
1754 if Ekind (New_S) = E_Procedure then
1756 Make_Procedure_Specification (Loc,
1757 Defining_Unit_Name =>
1758 Make_Defining_Identifier (Loc,
1759 Chars (Defining_Unit_Name (Spec))),
1760 Parameter_Specifications => Param_Specs);
1763 Make_Function_Specification (Loc,
1764 Defining_Unit_Name =>
1765 Make_Defining_Identifier (Loc,
1766 Chars (Defining_Unit_Name (Spec))),
1767 Parameter_Specifications => Param_Specs,
1768 Result_Definition =>
1769 New_Copy_Tree (Result_Definition (Spec)));
1773 -- Start of processing for Check_Class_Wide_Actual
1777 Formal_Type := Empty;
1778 Actual_Type := Empty;
1780 F := First_Formal (Formal_Spec);
1781 while Present (F) loop
1782 if Has_Unknown_Discriminants (Etype (F))
1783 and then not Is_Class_Wide_Type (Etype (F))
1784 and then Is_Class_Wide_Type (Get_Instance_Of (Etype (F)))
1786 Formal_Type := Etype (F);
1787 Actual_Type := Etype (Get_Instance_Of (Formal_Type));
1794 if Present (Formal_Type) then
1796 -- Create declaration and body for class-wide operation
1799 Make_Subprogram_Declaration (Loc, Specification => Make_Spec);
1802 Make_Subprogram_Body (Loc,
1803 Specification => Make_Spec,
1804 Declarations => No_List,
1805 Handled_Statement_Sequence =>
1806 Make_Handled_Sequence_Of_Statements (Loc, New_List));
1808 -- Modify Spec and create internal name for renaming of primitive
1811 Set_Defining_Unit_Name (Spec, Make_Temporary (Loc, 'R'));
1812 F := First (Parameter_Specifications (Spec));
1813 while Present (F) loop
1814 if Nkind (Parameter_Type (F)) = N_Identifier
1815 and then Is_Class_Wide_Type (Entity (Parameter_Type (F)))
1817 Set_Parameter_Type (F, New_Occurrence_Of (Actual_Type, Loc));
1822 New_S := Analyze_Subprogram_Specification (Spec);
1823 Result := Find_Renamed_Entity (N, Name (N), New_S, Is_Actual);
1826 if Result /= Any_Id then
1827 Insert_Before (N, New_Decl);
1830 -- Add dispatching call to body of class-wide operation
1832 Append (Make_Call (Result),
1833 Statements (Handled_Statement_Sequence (New_Body)));
1835 -- The generated body does not freeze. It is analyzed when the
1836 -- generated operation is frozen.
1838 Append_Freeze_Action (Defining_Entity (New_Decl), New_Body);
1840 Result := Defining_Entity (New_Decl);
1843 -- Return the class-wide operation if one was created
1846 end Check_Class_Wide_Actual;
1848 --------------------------
1849 -- Check_Null_Exclusion --
1850 --------------------------
1852 procedure Check_Null_Exclusion
1856 Ren_Formal : Entity_Id;
1857 Sub_Formal : Entity_Id;
1862 Ren_Formal := First_Formal (Ren);
1863 Sub_Formal := First_Formal (Sub);
1864 while Present (Ren_Formal)
1865 and then Present (Sub_Formal)
1867 if Has_Null_Exclusion (Parent (Ren_Formal))
1869 not (Has_Null_Exclusion (Parent (Sub_Formal))
1870 or else Can_Never_Be_Null (Etype (Sub_Formal)))
1873 ("`NOT NULL` required for parameter &",
1874 Parent (Sub_Formal), Sub_Formal);
1877 Next_Formal (Ren_Formal);
1878 Next_Formal (Sub_Formal);
1881 -- Return profile check
1883 if Nkind (Parent (Ren)) = N_Function_Specification
1884 and then Nkind (Parent (Sub)) = N_Function_Specification
1885 and then Has_Null_Exclusion (Parent (Ren))
1887 not (Has_Null_Exclusion (Parent (Sub))
1888 or else Can_Never_Be_Null (Etype (Sub)))
1891 ("return must specify `NOT NULL`",
1892 Result_Definition (Parent (Sub)));
1894 end Check_Null_Exclusion;
1896 ---------------------------
1897 -- Has_Class_Wide_Actual --
1898 ---------------------------
1900 function Has_Class_Wide_Actual return Boolean is
1906 and then Nkind (Nam) in N_Has_Entity
1907 and then Present (Entity (Nam))
1908 and then Is_Dispatching_Operation (Entity (Nam))
1910 F_Nam := First_Entity (Entity (Nam));
1911 F_Spec := First_Formal (Formal_Spec);
1912 while Present (F_Nam)
1913 and then Present (F_Spec)
1915 if Is_Controlling_Formal (F_Nam)
1916 and then Has_Unknown_Discriminants (Etype (F_Spec))
1917 and then not Is_Class_Wide_Type (Etype (F_Spec))
1918 and then Is_Class_Wide_Type (Get_Instance_Of (Etype (F_Spec)))
1923 Next_Entity (F_Nam);
1924 Next_Formal (F_Spec);
1929 end Has_Class_Wide_Actual;
1931 -------------------------
1932 -- Original_Subprogram --
1933 -------------------------
1935 function Original_Subprogram (Subp : Entity_Id) return Entity_Id is
1936 Orig_Decl : Node_Id;
1937 Orig_Subp : Entity_Id;
1940 -- First case: renamed entity is itself a renaming
1942 if Present (Alias (Subp)) then
1943 return Alias (Subp);
1946 Nkind (Unit_Declaration_Node (Subp)) = N_Subprogram_Declaration
1948 (Corresponding_Body (Unit_Declaration_Node (Subp)))
1950 -- Check if renamed entity is a renaming_as_body
1953 Unit_Declaration_Node
1954 (Corresponding_Body (Unit_Declaration_Node (Subp)));
1956 if Nkind (Orig_Decl) = N_Subprogram_Renaming_Declaration then
1957 Orig_Subp := Entity (Name (Orig_Decl));
1959 if Orig_Subp = Rename_Spec then
1961 -- Circularity detected
1966 return (Original_Subprogram (Orig_Subp));
1974 end Original_Subprogram;
1976 CW_Actual : constant Boolean := Has_Class_Wide_Actual;
1977 -- Ada 2012 (AI05-071, AI05-0131): True if the renaming is for a
1978 -- defaulted formal subprogram when the actual for a related formal
1979 -- type is class-wide.
1981 -- Start of processing for Analyze_Subprogram_Renaming
1984 -- We must test for the attribute renaming case before the Analyze
1985 -- call because otherwise Sem_Attr will complain that the attribute
1986 -- is missing an argument when it is analyzed.
1988 if Nkind (Nam) = N_Attribute_Reference then
1990 -- In the case of an abstract formal subprogram association, rewrite
1991 -- an actual given by a stream attribute as the name of the
1992 -- corresponding stream primitive of the type.
1994 -- In a generic context the stream operations are not generated, and
1995 -- this must be treated as a normal attribute reference, to be
1996 -- expanded in subsequent instantiations.
1998 if Is_Actual and then Is_Abstract_Subprogram (Formal_Spec)
1999 and then Expander_Active
2002 Stream_Prim : Entity_Id;
2003 Prefix_Type : constant Entity_Id := Entity (Prefix (Nam));
2006 -- The class-wide forms of the stream attributes are not
2007 -- primitive dispatching operations (even though they
2008 -- internally dispatch to a stream attribute).
2010 if Is_Class_Wide_Type (Prefix_Type) then
2012 ("attribute must be a primitive dispatching operation",
2017 -- Retrieve the primitive subprogram associated with the
2018 -- attribute. This can only be a stream attribute, since those
2019 -- are the only ones that are dispatching (and the actual for
2020 -- an abstract formal subprogram must be dispatching
2024 case Attribute_Name (Nam) is
2027 Find_Prim_Op (Prefix_Type, TSS_Stream_Input);
2030 Find_Prim_Op (Prefix_Type, TSS_Stream_Output);
2033 Find_Prim_Op (Prefix_Type, TSS_Stream_Read);
2036 Find_Prim_Op (Prefix_Type, TSS_Stream_Write);
2039 ("attribute must be a primitive"
2040 & " dispatching operation", Nam);
2046 -- If no operation was found, and the type is limited,
2047 -- the user should have defined one.
2049 when Program_Error =>
2050 if Is_Limited_Type (Prefix_Type) then
2052 ("stream operation not defined for type&",
2056 -- Otherwise, compiler should have generated default
2063 -- Rewrite the attribute into the name of its corresponding
2064 -- primitive dispatching subprogram. We can then proceed with
2065 -- the usual processing for subprogram renamings.
2068 Prim_Name : constant Node_Id :=
2069 Make_Identifier (Sloc (Nam),
2070 Chars => Chars (Stream_Prim));
2072 Set_Entity (Prim_Name, Stream_Prim);
2073 Rewrite (Nam, Prim_Name);
2078 -- Normal processing for a renaming of an attribute
2081 Attribute_Renaming (N);
2086 -- Check whether this declaration corresponds to the instantiation
2087 -- of a formal subprogram.
2089 -- If this is an instantiation, the corresponding actual is frozen and
2090 -- error messages can be made more precise. If this is a default
2091 -- subprogram, the entity is already established in the generic, and is
2092 -- not retrieved by visibility. If it is a default with a box, the
2093 -- candidate interpretations, if any, have been collected when building
2094 -- the renaming declaration. If overloaded, the proper interpretation is
2095 -- determined in Find_Renamed_Entity. If the entity is an operator,
2096 -- Find_Renamed_Entity applies additional visibility checks.
2099 Inst_Node := Unit_Declaration_Node (Formal_Spec);
2101 -- Check whether the renaming is for a defaulted actual subprogram
2102 -- with a class-wide actual.
2105 New_S := Analyze_Subprogram_Specification (Spec);
2106 Old_S := Check_Class_Wide_Actual;
2108 elsif Is_Entity_Name (Nam)
2109 and then Present (Entity (Nam))
2110 and then not Comes_From_Source (Nam)
2111 and then not Is_Overloaded (Nam)
2113 Old_S := Entity (Nam);
2114 New_S := Analyze_Subprogram_Specification (Spec);
2118 if Ekind (Entity (Nam)) = E_Operator then
2122 if Box_Present (Inst_Node) then
2123 Old_S := Find_Renamed_Entity (N, Name (N), New_S, Is_Actual);
2125 -- If there is an immediately visible homonym of the operator
2126 -- and the declaration has a default, this is worth a warning
2127 -- because the user probably did not intend to get the pre-
2128 -- defined operator, visible in the generic declaration. To
2129 -- find if there is an intended candidate, analyze the renaming
2130 -- again in the current context.
2132 elsif Scope (Old_S) = Standard_Standard
2133 and then Present (Default_Name (Inst_Node))
2136 Decl : constant Node_Id := New_Copy_Tree (N);
2140 Set_Entity (Name (Decl), Empty);
2141 Analyze (Name (Decl));
2143 Find_Renamed_Entity (Decl, Name (Decl), New_S, True);
2146 and then In_Open_Scopes (Scope (Hidden))
2147 and then Is_Immediately_Visible (Hidden)
2148 and then Comes_From_Source (Hidden)
2149 and then Hidden /= Old_S
2151 Error_Msg_Sloc := Sloc (Hidden);
2152 Error_Msg_N ("?default subprogram is resolved " &
2153 "in the generic declaration " &
2154 "(RM 12.6(17))", N);
2155 Error_Msg_NE ("\?and will not use & #", N, Hidden);
2163 New_S := Analyze_Subprogram_Specification (Spec);
2167 -- Renamed entity must be analyzed first, to avoid being hidden by
2168 -- new name (which might be the same in a generic instance).
2172 -- The renaming defines a new overloaded entity, which is analyzed
2173 -- like a subprogram declaration.
2175 New_S := Analyze_Subprogram_Specification (Spec);
2178 if Current_Scope /= Standard_Standard then
2179 Set_Is_Pure (New_S, Is_Pure (Current_Scope));
2182 Rename_Spec := Find_Corresponding_Spec (N);
2184 -- Case of Renaming_As_Body
2186 if Present (Rename_Spec) then
2188 -- Renaming declaration is the completion of the declaration of
2189 -- Rename_Spec. We build an actual body for it at the freezing point.
2191 Set_Corresponding_Spec (N, Rename_Spec);
2193 -- Deal with special case of stream functions of abstract types
2196 if Nkind (Unit_Declaration_Node (Rename_Spec)) =
2197 N_Abstract_Subprogram_Declaration
2199 -- Input stream functions are abstract if the object type is
2200 -- abstract. Similarly, all default stream functions for an
2201 -- interface type are abstract. However, these subprograms may
2202 -- receive explicit declarations in representation clauses, making
2203 -- the attribute subprograms usable as defaults in subsequent
2205 -- In this case we rewrite the declaration to make the subprogram
2206 -- non-abstract. We remove the previous declaration, and insert
2207 -- the new one at the point of the renaming, to prevent premature
2208 -- access to unfrozen types. The new declaration reuses the
2209 -- specification of the previous one, and must not be analyzed.
2212 (Is_Primitive (Entity (Nam))
2214 Is_Abstract_Type (Find_Dispatching_Type (Entity (Nam))));
2216 Old_Decl : constant Node_Id :=
2217 Unit_Declaration_Node (Rename_Spec);
2218 New_Decl : constant Node_Id :=
2219 Make_Subprogram_Declaration (Sloc (N),
2221 Relocate_Node (Specification (Old_Decl)));
2224 Insert_After (N, New_Decl);
2225 Set_Is_Abstract_Subprogram (Rename_Spec, False);
2226 Set_Analyzed (New_Decl);
2230 Set_Corresponding_Body (Unit_Declaration_Node (Rename_Spec), New_S);
2232 if Ada_Version = Ada_83 and then Comes_From_Source (N) then
2233 Error_Msg_N ("(Ada 83) renaming cannot serve as a body", N);
2236 Set_Convention (New_S, Convention (Rename_Spec));
2237 Check_Fully_Conformant (New_S, Rename_Spec);
2238 Set_Public_Status (New_S);
2240 -- The specification does not introduce new formals, but only
2241 -- repeats the formals of the original subprogram declaration.
2242 -- For cross-reference purposes, and for refactoring tools, we
2243 -- treat the formals of the renaming declaration as body formals.
2245 Reference_Body_Formals (Rename_Spec, New_S);
2247 -- Indicate that the entity in the declaration functions like the
2248 -- corresponding body, and is not a new entity. The body will be
2249 -- constructed later at the freeze point, so indicate that the
2250 -- completion has not been seen yet.
2252 Set_Ekind (New_S, E_Subprogram_Body);
2253 New_S := Rename_Spec;
2254 Set_Has_Completion (Rename_Spec, False);
2256 -- Ada 2005: check overriding indicator
2258 if Present (Overridden_Operation (Rename_Spec)) then
2259 if Must_Not_Override (Specification (N)) then
2261 ("subprogram& overrides inherited operation",
2264 Style_Check and then not Must_Override (Specification (N))
2266 Style.Missing_Overriding (N, Rename_Spec);
2269 elsif Must_Override (Specification (N)) then
2270 Error_Msg_NE ("subprogram& is not overriding", N, Rename_Spec);
2273 -- Normal subprogram renaming (not renaming as body)
2276 Generate_Definition (New_S);
2277 New_Overloaded_Entity (New_S);
2279 if Is_Entity_Name (Nam)
2280 and then Is_Intrinsic_Subprogram (Entity (Nam))
2284 Check_Delayed_Subprogram (New_S);
2288 -- There is no need for elaboration checks on the new entity, which may
2289 -- be called before the next freezing point where the body will appear.
2290 -- Elaboration checks refer to the real entity, not the one created by
2291 -- the renaming declaration.
2293 Set_Kill_Elaboration_Checks (New_S, True);
2295 if Etype (Nam) = Any_Type then
2296 Set_Has_Completion (New_S);
2299 elsif Nkind (Nam) = N_Selected_Component then
2301 -- A prefix of the form A.B can designate an entry of task A, a
2302 -- protected operation of protected object A, or finally a primitive
2303 -- operation of object A. In the later case, A is an object of some
2304 -- tagged type, or an access type that denotes one such. To further
2305 -- distinguish these cases, note that the scope of a task entry or
2306 -- protected operation is type of the prefix.
2308 -- The prefix could be an overloaded function call that returns both
2309 -- kinds of operations. This overloading pathology is left to the
2310 -- dedicated reader ???
2313 T : constant Entity_Id := Etype (Prefix (Nam));
2322 Is_Tagged_Type (Designated_Type (T))))
2323 and then Scope (Entity (Selector_Name (Nam))) /= T
2325 Analyze_Renamed_Primitive_Operation
2326 (N, New_S, Present (Rename_Spec));
2330 -- Renamed entity is an entry or protected operation. For those
2331 -- cases an explicit body is built (at the point of freezing of
2332 -- this entity) that contains a call to the renamed entity.
2334 -- This is not allowed for renaming as body if the renamed
2335 -- spec is already frozen (see RM 8.5.4(5) for details).
2337 if Present (Rename_Spec)
2338 and then Is_Frozen (Rename_Spec)
2341 ("renaming-as-body cannot rename entry as subprogram", N);
2343 ("\since & is already frozen (RM 8.5.4(5))",
2346 Analyze_Renamed_Entry (N, New_S, Present (Rename_Spec));
2353 elsif Nkind (Nam) = N_Explicit_Dereference then
2355 -- Renamed entity is designated by access_to_subprogram expression.
2356 -- Must build body to encapsulate call, as in the entry case.
2358 Analyze_Renamed_Dereference (N, New_S, Present (Rename_Spec));
2361 elsif Nkind (Nam) = N_Indexed_Component then
2362 Analyze_Renamed_Family_Member (N, New_S, Present (Rename_Spec));
2365 elsif Nkind (Nam) = N_Character_Literal then
2366 Analyze_Renamed_Character (N, New_S, Present (Rename_Spec));
2369 elsif not Is_Entity_Name (Nam)
2370 or else not Is_Overloadable (Entity (Nam))
2372 Error_Msg_N ("expect valid subprogram name in renaming", N);
2376 -- Find the renamed entity that matches the given specification. Disable
2377 -- Ada_83 because there is no requirement of full conformance between
2378 -- renamed entity and new entity, even though the same circuit is used.
2380 -- This is a bit of a kludge, which introduces a really irregular use of
2381 -- Ada_Version[_Explicit]. Would be nice to find cleaner way to do this
2384 Ada_Version := Ada_Version_Type'Max (Ada_Version, Ada_95);
2385 Ada_Version_Explicit := Ada_Version;
2388 Old_S := Find_Renamed_Entity (N, Name (N), New_S, Is_Actual);
2390 -- The visible operation may be an inherited abstract operation that
2391 -- was overridden in the private part, in which case a call will
2392 -- dispatch to the overriding operation. Use the overriding one in
2393 -- the renaming declaration, to prevent spurious errors below.
2395 if Is_Overloadable (Old_S)
2396 and then Is_Abstract_Subprogram (Old_S)
2397 and then No (DTC_Entity (Old_S))
2398 and then Present (Alias (Old_S))
2399 and then not Is_Abstract_Subprogram (Alias (Old_S))
2400 and then Present (Overridden_Operation (Alias (Old_S)))
2402 Old_S := Alias (Old_S);
2405 -- When the renamed subprogram is overloaded and used as an actual
2406 -- of a generic, its entity is set to the first available homonym.
2407 -- We must first disambiguate the name, then set the proper entity.
2409 if Is_Actual and then Is_Overloaded (Nam) then
2410 Set_Entity (Nam, Old_S);
2414 -- Most common case: subprogram renames subprogram. No body is generated
2415 -- in this case, so we must indicate the declaration is complete as is.
2416 -- and inherit various attributes of the renamed subprogram.
2418 if No (Rename_Spec) then
2419 Set_Has_Completion (New_S);
2420 Set_Is_Imported (New_S, Is_Imported (Entity (Nam)));
2421 Set_Is_Pure (New_S, Is_Pure (Entity (Nam)));
2422 Set_Is_Preelaborated (New_S, Is_Preelaborated (Entity (Nam)));
2424 -- Ada 2005 (AI-423): Check the consistency of null exclusions
2425 -- between a subprogram and its correct renaming.
2427 -- Note: the Any_Id check is a guard that prevents compiler crashes
2428 -- when performing a null exclusion check between a renaming and a
2429 -- renamed subprogram that has been found to be illegal.
2431 if Ada_Version >= Ada_2005
2432 and then Entity (Nam) /= Any_Id
2434 Check_Null_Exclusion
2436 Sub => Entity (Nam));
2439 -- Enforce the Ada 2005 rule that the renamed entity cannot require
2440 -- overriding. The flag Requires_Overriding is set very selectively
2441 -- and misses some other illegal cases. The additional conditions
2442 -- checked below are sufficient but not necessary ???
2444 -- The rule does not apply to the renaming generated for an actual
2445 -- subprogram in an instance.
2450 -- Guard against previous errors, and omit renamings of predefined
2453 elsif not Ekind_In (Old_S, E_Function, E_Procedure) then
2456 elsif Requires_Overriding (Old_S)
2458 (Is_Abstract_Subprogram (Old_S)
2459 and then Present (Find_Dispatching_Type (Old_S))
2461 not Is_Abstract_Type (Find_Dispatching_Type (Old_S)))
2464 ("renamed entity cannot be "
2465 & "subprogram that requires overriding (RM 8.5.4 (5.1))", N);
2469 if Old_S /= Any_Id then
2470 if Is_Actual and then From_Default (N) then
2472 -- This is an implicit reference to the default actual
2474 Generate_Reference (Old_S, Nam, Typ => 'i', Force => True);
2477 Generate_Reference (Old_S, Nam);
2480 -- For a renaming-as-body, require subtype conformance, but if the
2481 -- declaration being completed has not been frozen, then inherit the
2482 -- convention of the renamed subprogram prior to checking conformance
2483 -- (unless the renaming has an explicit convention established; the
2484 -- rule stated in the RM doesn't seem to address this ???).
2486 if Present (Rename_Spec) then
2487 Generate_Reference (Rename_Spec, Defining_Entity (Spec), 'b');
2488 Style.Check_Identifier (Defining_Entity (Spec), Rename_Spec);
2490 if not Is_Frozen (Rename_Spec) then
2491 if not Has_Convention_Pragma (Rename_Spec) then
2492 Set_Convention (New_S, Convention (Old_S));
2495 if Ekind (Old_S) /= E_Operator then
2496 Check_Mode_Conformant (New_S, Old_S, Spec);
2499 if Original_Subprogram (Old_S) = Rename_Spec then
2500 Error_Msg_N ("unfrozen subprogram cannot rename itself ", N);
2503 Check_Subtype_Conformant (New_S, Old_S, Spec);
2506 Check_Frozen_Renaming (N, Rename_Spec);
2508 -- Check explicitly that renamed entity is not intrinsic, because
2509 -- in a generic the renamed body is not built. In this case,
2510 -- the renaming_as_body is a completion.
2512 if Inside_A_Generic then
2513 if Is_Frozen (Rename_Spec)
2514 and then Is_Intrinsic_Subprogram (Old_S)
2517 ("subprogram in renaming_as_body cannot be intrinsic",
2521 Set_Has_Completion (Rename_Spec);
2524 elsif Ekind (Old_S) /= E_Operator then
2526 -- If this a defaulted subprogram for a class-wide actual there is
2527 -- no check for mode conformance, given that the signatures don't
2528 -- match (the source mentions T but the actual mentions T'Class).
2533 Check_Mode_Conformant (New_S, Old_S);
2537 and then Error_Posted (New_S)
2539 Error_Msg_NE ("invalid actual subprogram: & #!", N, Old_S);
2543 if No (Rename_Spec) then
2545 -- The parameter profile of the new entity is that of the renamed
2546 -- entity: the subtypes given in the specification are irrelevant.
2548 Inherit_Renamed_Profile (New_S, Old_S);
2550 -- A call to the subprogram is transformed into a call to the
2551 -- renamed entity. This is transitive if the renamed entity is
2552 -- itself a renaming.
2554 if Present (Alias (Old_S)) then
2555 Set_Alias (New_S, Alias (Old_S));
2557 Set_Alias (New_S, Old_S);
2560 -- Note that we do not set Is_Intrinsic_Subprogram if we have a
2561 -- renaming as body, since the entity in this case is not an
2562 -- intrinsic (it calls an intrinsic, but we have a real body for
2563 -- this call, and it is in this body that the required intrinsic
2564 -- processing will take place).
2566 -- Also, if this is a renaming of inequality, the renamed operator
2567 -- is intrinsic, but what matters is the corresponding equality
2568 -- operator, which may be user-defined.
2570 Set_Is_Intrinsic_Subprogram
2572 Is_Intrinsic_Subprogram (Old_S)
2574 (Chars (Old_S) /= Name_Op_Ne
2575 or else Ekind (Old_S) = E_Operator
2577 Is_Intrinsic_Subprogram
2578 (Corresponding_Equality (Old_S))));
2580 if Ekind (Alias (New_S)) = E_Operator then
2581 Set_Has_Delayed_Freeze (New_S, False);
2584 -- If the renaming corresponds to an association for an abstract
2585 -- formal subprogram, then various attributes must be set to
2586 -- indicate that the renaming is an abstract dispatching operation
2587 -- with a controlling type.
2589 if Is_Actual and then Is_Abstract_Subprogram (Formal_Spec) then
2591 -- Mark the renaming as abstract here, so Find_Dispatching_Type
2592 -- see it as corresponding to a generic association for a
2593 -- formal abstract subprogram
2595 Set_Is_Abstract_Subprogram (New_S);
2598 New_S_Ctrl_Type : constant Entity_Id :=
2599 Find_Dispatching_Type (New_S);
2600 Old_S_Ctrl_Type : constant Entity_Id :=
2601 Find_Dispatching_Type (Old_S);
2604 if Old_S_Ctrl_Type /= New_S_Ctrl_Type then
2606 ("actual must be dispatching subprogram for type&",
2607 Nam, New_S_Ctrl_Type);
2610 Set_Is_Dispatching_Operation (New_S);
2611 Check_Controlling_Formals (New_S_Ctrl_Type, New_S);
2613 -- If the actual in the formal subprogram is itself a
2614 -- formal abstract subprogram association, there's no
2615 -- dispatch table component or position to inherit.
2617 if Present (DTC_Entity (Old_S)) then
2618 Set_DTC_Entity (New_S, DTC_Entity (Old_S));
2619 Set_DT_Position (New_S, DT_Position (Old_S));
2627 and then (Old_S = New_S
2628 or else (Nkind (Nam) /= N_Expanded_Name
2629 and then Chars (Old_S) = Chars (New_S)))
2631 Error_Msg_N ("subprogram cannot rename itself", N);
2634 Set_Convention (New_S, Convention (Old_S));
2636 if Is_Abstract_Subprogram (Old_S) then
2637 if Present (Rename_Spec) then
2639 ("a renaming-as-body cannot rename an abstract subprogram",
2641 Set_Has_Completion (Rename_Spec);
2643 Set_Is_Abstract_Subprogram (New_S);
2647 Check_Library_Unit_Renaming (N, Old_S);
2649 -- Pathological case: procedure renames entry in the scope of its
2650 -- task. Entry is given by simple name, but body must be built for
2651 -- procedure. Of course if called it will deadlock.
2653 if Ekind (Old_S) = E_Entry then
2654 Set_Has_Completion (New_S, False);
2655 Set_Alias (New_S, Empty);
2659 Freeze_Before (N, Old_S);
2660 Set_Has_Delayed_Freeze (New_S, False);
2661 Freeze_Before (N, New_S);
2663 -- An abstract subprogram is only allowed as an actual in the case
2664 -- where the formal subprogram is also abstract.
2666 if (Ekind (Old_S) = E_Procedure or else Ekind (Old_S) = E_Function)
2667 and then Is_Abstract_Subprogram (Old_S)
2668 and then not Is_Abstract_Subprogram (Formal_Spec)
2671 ("abstract subprogram not allowed as generic actual", Nam);
2676 -- A common error is to assume that implicit operators for types are
2677 -- defined in Standard, or in the scope of a subtype. In those cases
2678 -- where the renamed entity is given with an expanded name, it is
2679 -- worth mentioning that operators for the type are not declared in
2680 -- the scope given by the prefix.
2682 if Nkind (Nam) = N_Expanded_Name
2683 and then Nkind (Selector_Name (Nam)) = N_Operator_Symbol
2684 and then Scope (Entity (Nam)) = Standard_Standard
2687 T : constant Entity_Id :=
2688 Base_Type (Etype (First_Formal (New_S)));
2690 Error_Msg_Node_2 := Prefix (Nam);
2692 ("operator for type& is not declared in&", Prefix (Nam), T);
2697 ("no visible subprogram matches the specification for&",
2701 if Present (Candidate_Renaming) then
2708 F1 := First_Formal (Candidate_Renaming);
2709 F2 := First_Formal (New_S);
2710 T1 := First_Subtype (Etype (F1));
2712 while Present (F1) and then Present (F2) loop
2717 if Present (F1) and then Present (Default_Value (F1)) then
2718 if Present (Next_Formal (F1)) then
2720 ("\missing specification for &" &
2721 " and other formals with defaults", Spec, F1);
2724 ("\missing specification for &", Spec, F1);
2728 if Nkind (Nam) = N_Operator_Symbol
2729 and then From_Default (N)
2731 Error_Msg_Node_2 := T1;
2733 ("default & on & is not directly visible",
2740 -- Ada 2005 AI 404: if the new subprogram is dispatching, verify that
2741 -- controlling access parameters are known non-null for the renamed
2742 -- subprogram. Test also applies to a subprogram instantiation that
2743 -- is dispatching. Test is skipped if some previous error was detected
2744 -- that set Old_S to Any_Id.
2746 if Ada_Version >= Ada_2005
2747 and then Old_S /= Any_Id
2748 and then not Is_Dispatching_Operation (Old_S)
2749 and then Is_Dispatching_Operation (New_S)
2756 Old_F := First_Formal (Old_S);
2757 New_F := First_Formal (New_S);
2758 while Present (Old_F) loop
2759 if Ekind (Etype (Old_F)) = E_Anonymous_Access_Type
2760 and then Is_Controlling_Formal (New_F)
2761 and then not Can_Never_Be_Null (Old_F)
2763 Error_Msg_N ("access parameter is controlling,", New_F);
2765 ("\corresponding parameter of& "
2766 & "must be explicitly null excluding", New_F, Old_S);
2769 Next_Formal (Old_F);
2770 Next_Formal (New_F);
2775 -- A useful warning, suggested by Ada Bug Finder (Ada-Europe 2005)
2776 -- is to warn if an operator is being renamed as a different operator.
2777 -- If the operator is predefined, examine the kind of the entity, not
2778 -- the abbreviated declaration in Standard.
2780 if Comes_From_Source (N)
2781 and then Present (Old_S)
2783 (Nkind (Old_S) = N_Defining_Operator_Symbol
2784 or else Ekind (Old_S) = E_Operator)
2785 and then Nkind (New_S) = N_Defining_Operator_Symbol
2786 and then Chars (Old_S) /= Chars (New_S)
2789 ("?& is being renamed as a different operator", N, Old_S);
2792 -- Check for renaming of obsolescent subprogram
2794 Check_Obsolescent_2005_Entity (Entity (Nam), Nam);
2796 -- Another warning or some utility: if the new subprogram as the same
2797 -- name as the old one, the old one is not hidden by an outer homograph,
2798 -- the new one is not a public symbol, and the old one is otherwise
2799 -- directly visible, the renaming is superfluous.
2801 if Chars (Old_S) = Chars (New_S)
2802 and then Comes_From_Source (N)
2803 and then Scope (Old_S) /= Standard_Standard
2804 and then Warn_On_Redundant_Constructs
2806 (Is_Immediately_Visible (Old_S)
2807 or else Is_Potentially_Use_Visible (Old_S))
2808 and then Is_Overloadable (Current_Scope)
2809 and then Chars (Current_Scope) /= Chars (Old_S)
2812 ("?redundant renaming, entity is directly visible", Name (N));
2815 Ada_Version := Save_AV;
2816 Ada_Version_Explicit := Save_AV_Exp;
2817 end Analyze_Subprogram_Renaming;
2819 -------------------------
2820 -- Analyze_Use_Package --
2821 -------------------------
2823 -- Resolve the package names in the use clause, and make all the visible
2824 -- entities defined in the package potentially use-visible. If the package
2825 -- is already in use from a previous use clause, its visible entities are
2826 -- already use-visible. In that case, mark the occurrence as a redundant
2827 -- use. If the package is an open scope, i.e. if the use clause occurs
2828 -- within the package itself, ignore it.
2830 procedure Analyze_Use_Package (N : Node_Id) is
2831 Pack_Name : Node_Id;
2834 -- Start of processing for Analyze_Use_Package
2837 Check_SPARK_Restriction ("use clause is not allowed", N);
2839 Set_Hidden_By_Use_Clause (N, No_Elist);
2841 -- Use clause not allowed in a spec of a predefined package declaration
2842 -- except that packages whose file name starts a-n are OK (these are
2843 -- children of Ada.Numerics, which are never loaded by Rtsfind).
2845 if Is_Predefined_File_Name (Unit_File_Name (Current_Sem_Unit))
2846 and then Name_Buffer (1 .. 3) /= "a-n"
2848 Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Declaration
2850 Error_Msg_N ("use clause not allowed in predefined spec", N);
2853 -- Chain clause to list of use clauses in current scope
2855 if Nkind (Parent (N)) /= N_Compilation_Unit then
2856 Chain_Use_Clause (N);
2859 -- Loop through package names to identify referenced packages
2861 Pack_Name := First (Names (N));
2862 while Present (Pack_Name) loop
2863 Analyze (Pack_Name);
2865 if Nkind (Parent (N)) = N_Compilation_Unit
2866 and then Nkind (Pack_Name) = N_Expanded_Name
2872 Pref := Prefix (Pack_Name);
2873 while Nkind (Pref) = N_Expanded_Name loop
2874 Pref := Prefix (Pref);
2877 if Entity (Pref) = Standard_Standard then
2879 ("predefined package Standard cannot appear"
2880 & " in a context clause", Pref);
2888 -- Loop through package names to mark all entities as potentially
2891 Pack_Name := First (Names (N));
2892 while Present (Pack_Name) loop
2893 if Is_Entity_Name (Pack_Name) then
2894 Pack := Entity (Pack_Name);
2896 if Ekind (Pack) /= E_Package
2897 and then Etype (Pack) /= Any_Type
2899 if Ekind (Pack) = E_Generic_Package then
2900 Error_Msg_N -- CODEFIX
2901 ("a generic package is not allowed in a use clause",
2904 Error_Msg_N ("& is not a usable package", Pack_Name);
2908 if Nkind (Parent (N)) = N_Compilation_Unit then
2909 Check_In_Previous_With_Clause (N, Pack_Name);
2912 if Applicable_Use (Pack_Name) then
2913 Use_One_Package (Pack, N);
2917 -- Report error because name denotes something other than a package
2920 Error_Msg_N ("& is not a package", Pack_Name);
2925 end Analyze_Use_Package;
2927 ----------------------
2928 -- Analyze_Use_Type --
2929 ----------------------
2931 procedure Analyze_Use_Type (N : Node_Id) is
2936 Set_Hidden_By_Use_Clause (N, No_Elist);
2938 -- Chain clause to list of use clauses in current scope
2940 if Nkind (Parent (N)) /= N_Compilation_Unit then
2941 Chain_Use_Clause (N);
2944 -- If the Used_Operations list is already initialized, the clause has
2945 -- been analyzed previously, and it is begin reinstalled, for example
2946 -- when the clause appears in a package spec and we are compiling the
2947 -- corresponding package body. In that case, make the entities on the
2948 -- existing list use_visible, and mark the corresponding types In_Use.
2950 if Present (Used_Operations (N)) then
2956 Mark := First (Subtype_Marks (N));
2957 while Present (Mark) loop
2958 Use_One_Type (Mark, Installed => True);
2962 Elmt := First_Elmt (Used_Operations (N));
2963 while Present (Elmt) loop
2964 Set_Is_Potentially_Use_Visible (Node (Elmt));
2972 -- Otherwise, create new list and attach to it the operations that
2973 -- are made use-visible by the clause.
2975 Set_Used_Operations (N, New_Elmt_List);
2976 Id := First (Subtype_Marks (N));
2977 while Present (Id) loop
2981 if E /= Any_Type then
2984 if Nkind (Parent (N)) = N_Compilation_Unit then
2985 if Nkind (Id) = N_Identifier then
2986 Error_Msg_N ("type is not directly visible", Id);
2988 elsif Is_Child_Unit (Scope (E))
2989 and then Scope (E) /= System_Aux_Id
2991 Check_In_Previous_With_Clause (N, Prefix (Id));
2996 -- If the use_type_clause appears in a compilation unit context,
2997 -- check whether it comes from a unit that may appear in a
2998 -- limited_with_clause, for a better error message.
3000 if Nkind (Parent (N)) = N_Compilation_Unit
3001 and then Nkind (Id) /= N_Identifier
3007 function Mentioned (Nam : Node_Id) return Boolean;
3008 -- Check whether the prefix of expanded name for the type
3009 -- appears in the prefix of some limited_with_clause.
3015 function Mentioned (Nam : Node_Id) return Boolean is
3017 return Nkind (Name (Item)) = N_Selected_Component
3019 Chars (Prefix (Name (Item))) = Chars (Nam);
3023 Pref := Prefix (Id);
3024 Item := First (Context_Items (Parent (N)));
3026 while Present (Item) and then Item /= N loop
3027 if Nkind (Item) = N_With_Clause
3028 and then Limited_Present (Item)
3029 and then Mentioned (Pref)
3032 (Get_Msg_Id, "premature usage of incomplete type");
3043 end Analyze_Use_Type;
3045 --------------------
3046 -- Applicable_Use --
3047 --------------------
3049 function Applicable_Use (Pack_Name : Node_Id) return Boolean is
3050 Pack : constant Entity_Id := Entity (Pack_Name);
3053 if In_Open_Scopes (Pack) then
3054 if Warn_On_Redundant_Constructs
3055 and then Pack = Current_Scope
3057 Error_Msg_NE -- CODEFIX
3058 ("& is already use-visible within itself?", Pack_Name, Pack);
3063 elsif In_Use (Pack) then
3064 Note_Redundant_Use (Pack_Name);
3067 elsif Present (Renamed_Object (Pack))
3068 and then In_Use (Renamed_Object (Pack))
3070 Note_Redundant_Use (Pack_Name);
3078 ------------------------
3079 -- Attribute_Renaming --
3080 ------------------------
3082 procedure Attribute_Renaming (N : Node_Id) is
3083 Loc : constant Source_Ptr := Sloc (N);
3084 Nam : constant Node_Id := Name (N);
3085 Spec : constant Node_Id := Specification (N);
3086 New_S : constant Entity_Id := Defining_Unit_Name (Spec);
3087 Aname : constant Name_Id := Attribute_Name (Nam);
3089 Form_Num : Nat := 0;
3090 Expr_List : List_Id := No_List;
3092 Attr_Node : Node_Id;
3093 Body_Node : Node_Id;
3094 Param_Spec : Node_Id;
3097 Generate_Definition (New_S);
3099 -- This procedure is called in the context of subprogram renaming, and
3100 -- thus the attribute must be one that is a subprogram. All of those
3101 -- have at least one formal parameter, with the singular exception of
3102 -- AST_Entry (which is a real oddity, it is odd that this can be renamed
3105 if not Is_Non_Empty_List (Parameter_Specifications (Spec)) then
3106 if Aname /= Name_AST_Entry then
3108 ("subprogram renaming an attribute must have formals", N);
3113 Param_Spec := First (Parameter_Specifications (Spec));
3114 while Present (Param_Spec) loop
3115 Form_Num := Form_Num + 1;
3117 if Nkind (Parameter_Type (Param_Spec)) /= N_Access_Definition then
3118 Find_Type (Parameter_Type (Param_Spec));
3120 -- The profile of the new entity denotes the base type (s) of
3121 -- the types given in the specification. For access parameters
3122 -- there are no subtypes involved.
3124 Rewrite (Parameter_Type (Param_Spec),
3126 (Base_Type (Entity (Parameter_Type (Param_Spec))), Loc));
3129 if No (Expr_List) then
3130 Expr_List := New_List;
3133 Append_To (Expr_List,
3134 Make_Identifier (Loc,
3135 Chars => Chars (Defining_Identifier (Param_Spec))));
3137 -- The expressions in the attribute reference are not freeze
3138 -- points. Neither is the attribute as a whole, see below.
3140 Set_Must_Not_Freeze (Last (Expr_List));
3145 -- Immediate error if too many formals. Other mismatches in number or
3146 -- types of parameters are detected when we analyze the body of the
3147 -- subprogram that we construct.
3149 if Form_Num > 2 then
3150 Error_Msg_N ("too many formals for attribute", N);
3152 -- Error if the attribute reference has expressions that look like
3153 -- formal parameters.
3155 elsif Present (Expressions (Nam)) then
3156 Error_Msg_N ("illegal expressions in attribute reference", Nam);
3159 Aname = Name_Compose or else
3160 Aname = Name_Exponent or else
3161 Aname = Name_Leading_Part or else
3162 Aname = Name_Pos or else
3163 Aname = Name_Round or else
3164 Aname = Name_Scaling or else
3167 if Nkind (N) = N_Subprogram_Renaming_Declaration
3168 and then Present (Corresponding_Formal_Spec (N))
3171 ("generic actual cannot be attribute involving universal type",
3175 ("attribute involving a universal type cannot be renamed",
3180 -- AST_Entry is an odd case. It doesn't really make much sense to allow
3181 -- it to be renamed, but that's the DEC rule, so we have to do it right.
3182 -- The point is that the AST_Entry call should be made now, and what the
3183 -- function will return is the returned value.
3185 -- Note that there is no Expr_List in this case anyway
3187 if Aname = Name_AST_Entry then
3189 Ent : constant Entity_Id := Make_Temporary (Loc, 'R', Nam);
3194 Make_Object_Declaration (Loc,
3195 Defining_Identifier => Ent,
3196 Object_Definition =>
3197 New_Occurrence_Of (RTE (RE_AST_Handler), Loc),
3199 Constant_Present => True);
3201 Set_Assignment_OK (Decl, True);
3202 Insert_Action (N, Decl);
3203 Attr_Node := Make_Identifier (Loc, Chars (Ent));
3206 -- For all other attributes, we rewrite the attribute node to have
3207 -- a list of expressions corresponding to the subprogram formals.
3208 -- A renaming declaration is not a freeze point, and the analysis of
3209 -- the attribute reference should not freeze the type of the prefix.
3213 Make_Attribute_Reference (Loc,
3214 Prefix => Prefix (Nam),
3215 Attribute_Name => Aname,
3216 Expressions => Expr_List);
3218 Set_Must_Not_Freeze (Attr_Node);
3219 Set_Must_Not_Freeze (Prefix (Nam));
3222 -- Case of renaming a function
3224 if Nkind (Spec) = N_Function_Specification then
3225 if Is_Procedure_Attribute_Name (Aname) then
3226 Error_Msg_N ("attribute can only be renamed as procedure", Nam);
3230 Find_Type (Result_Definition (Spec));
3231 Rewrite (Result_Definition (Spec),
3233 Base_Type (Entity (Result_Definition (Spec))), Loc));
3236 Make_Subprogram_Body (Loc,
3237 Specification => Spec,
3238 Declarations => New_List,
3239 Handled_Statement_Sequence =>
3240 Make_Handled_Sequence_Of_Statements (Loc,
3241 Statements => New_List (
3242 Make_Simple_Return_Statement (Loc,
3243 Expression => Attr_Node))));
3245 -- Case of renaming a procedure
3248 if not Is_Procedure_Attribute_Name (Aname) then
3249 Error_Msg_N ("attribute can only be renamed as function", Nam);
3254 Make_Subprogram_Body (Loc,
3255 Specification => Spec,
3256 Declarations => New_List,
3257 Handled_Statement_Sequence =>
3258 Make_Handled_Sequence_Of_Statements (Loc,
3259 Statements => New_List (Attr_Node)));
3262 -- In case of tagged types we add the body of the generated function to
3263 -- the freezing actions of the type (because in the general case such
3264 -- type is still not frozen). We exclude from this processing generic
3265 -- formal subprograms found in instantiations and AST_Entry renamings.
3267 -- We must exclude VM targets because entity AST_Handler is defined in
3268 -- package System.Aux_Dec which is not available in those platforms.
3270 if VM_Target = No_VM
3271 and then not Present (Corresponding_Formal_Spec (N))
3272 and then Etype (Nam) /= RTE (RE_AST_Handler)
3275 P : constant Entity_Id := Prefix (Nam);
3280 if Is_Tagged_Type (Etype (P)) then
3281 Ensure_Freeze_Node (Etype (P));
3282 Append_Freeze_Action (Etype (P), Body_Node);
3284 Rewrite (N, Body_Node);
3286 Set_Etype (New_S, Base_Type (Etype (New_S)));
3290 -- Generic formal subprograms or AST_Handler renaming
3293 Rewrite (N, Body_Node);
3295 Set_Etype (New_S, Base_Type (Etype (New_S)));
3298 if Is_Compilation_Unit (New_S) then
3300 ("a library unit can only rename another library unit", N);
3303 -- We suppress elaboration warnings for the resulting entity, since
3304 -- clearly they are not needed, and more particularly, in the case
3305 -- of a generic formal subprogram, the resulting entity can appear
3306 -- after the instantiation itself, and thus look like a bogus case
3307 -- of access before elaboration.
3309 Set_Suppress_Elaboration_Warnings (New_S);
3311 end Attribute_Renaming;
3313 ----------------------
3314 -- Chain_Use_Clause --
3315 ----------------------
3317 procedure Chain_Use_Clause (N : Node_Id) is
3319 Level : Int := Scope_Stack.Last;
3322 if not Is_Compilation_Unit (Current_Scope)
3323 or else not Is_Child_Unit (Current_Scope)
3325 null; -- Common case
3327 elsif Defining_Entity (Parent (N)) = Current_Scope then
3328 null; -- Common case for compilation unit
3331 -- If declaration appears in some other scope, it must be in some
3332 -- parent unit when compiling a child.
3334 Pack := Defining_Entity (Parent (N));
3335 if not In_Open_Scopes (Pack) then
3336 null; -- default as well
3339 -- Find entry for parent unit in scope stack
3341 while Scope_Stack.Table (Level).Entity /= Pack loop
3347 Set_Next_Use_Clause (N,
3348 Scope_Stack.Table (Level).First_Use_Clause);
3349 Scope_Stack.Table (Level).First_Use_Clause := N;
3350 end Chain_Use_Clause;
3352 ---------------------------
3353 -- Check_Frozen_Renaming --
3354 ---------------------------
3356 procedure Check_Frozen_Renaming (N : Node_Id; Subp : Entity_Id) is
3362 and then not Has_Completion (Subp)
3366 (Parent (Declaration_Node (Subp)), Defining_Entity (N));
3368 if Is_Entity_Name (Name (N)) then
3369 Old_S := Entity (Name (N));
3371 if not Is_Frozen (Old_S)
3372 and then Operating_Mode /= Check_Semantics
3374 Append_Freeze_Action (Old_S, B_Node);
3376 Insert_After (N, B_Node);
3380 if Is_Intrinsic_Subprogram (Old_S)
3381 and then not In_Instance
3384 ("subprogram used in renaming_as_body cannot be intrinsic",
3389 Insert_After (N, B_Node);
3393 end Check_Frozen_Renaming;
3395 -------------------------------
3396 -- Set_Entity_Or_Discriminal --
3397 -------------------------------
3399 procedure Set_Entity_Or_Discriminal (N : Node_Id; E : Entity_Id) is
3403 -- If the entity is not a discriminant, or else expansion is disabled,
3404 -- simply set the entity.
3406 if not In_Spec_Expression
3407 or else Ekind (E) /= E_Discriminant
3408 or else Inside_A_Generic
3410 Set_Entity_With_Style_Check (N, E);
3412 -- The replacement of a discriminant by the corresponding discriminal
3413 -- is not done for a task discriminant that appears in a default
3414 -- expression of an entry parameter. See Exp_Ch2.Expand_Discriminant
3415 -- for details on their handling.
3417 elsif Is_Concurrent_Type (Scope (E)) then
3421 and then not Nkind_In (P, N_Parameter_Specification,
3422 N_Component_Declaration)
3428 and then Nkind (P) = N_Parameter_Specification
3433 Set_Entity (N, Discriminal (E));
3436 -- Otherwise, this is a discriminant in a context in which
3437 -- it is a reference to the corresponding parameter of the
3438 -- init proc for the enclosing type.
3441 Set_Entity (N, Discriminal (E));
3443 end Set_Entity_Or_Discriminal;
3445 -----------------------------------
3446 -- Check_In_Previous_With_Clause --
3447 -----------------------------------
3449 procedure Check_In_Previous_With_Clause
3453 Pack : constant Entity_Id := Entity (Original_Node (Nam));
3458 Item := First (Context_Items (Parent (N)));
3460 while Present (Item)
3463 if Nkind (Item) = N_With_Clause
3465 -- Protect the frontend against previous critical errors
3467 and then Nkind (Name (Item)) /= N_Selected_Component
3468 and then Entity (Name (Item)) = Pack
3472 -- Find root library unit in with_clause
3474 while Nkind (Par) = N_Expanded_Name loop
3475 Par := Prefix (Par);
3478 if Is_Child_Unit (Entity (Original_Node (Par))) then
3479 Error_Msg_NE ("& is not directly visible", Par, Entity (Par));
3488 -- On exit, package is not mentioned in a previous with_clause.
3489 -- Check if its prefix is.
3491 if Nkind (Nam) = N_Expanded_Name then
3492 Check_In_Previous_With_Clause (N, Prefix (Nam));
3494 elsif Pack /= Any_Id then
3495 Error_Msg_NE ("& is not visible", Nam, Pack);
3497 end Check_In_Previous_With_Clause;
3499 ---------------------------------
3500 -- Check_Library_Unit_Renaming --
3501 ---------------------------------
3503 procedure Check_Library_Unit_Renaming (N : Node_Id; Old_E : Entity_Id) is
3507 if Nkind (Parent (N)) /= N_Compilation_Unit then
3510 -- Check for library unit. Note that we used to check for the scope
3511 -- being Standard here, but that was wrong for Standard itself.
3513 elsif not Is_Compilation_Unit (Old_E)
3514 and then not Is_Child_Unit (Old_E)
3516 Error_Msg_N ("renamed unit must be a library unit", Name (N));
3518 -- Entities defined in Standard (operators and boolean literals) cannot
3519 -- be renamed as library units.
3521 elsif Scope (Old_E) = Standard_Standard
3522 and then Sloc (Old_E) = Standard_Location
3524 Error_Msg_N ("renamed unit must be a library unit", Name (N));
3526 elsif Present (Parent_Spec (N))
3527 and then Nkind (Unit (Parent_Spec (N))) = N_Generic_Package_Declaration
3528 and then not Is_Child_Unit (Old_E)
3531 ("renamed unit must be a child unit of generic parent", Name (N));
3533 elsif Nkind (N) in N_Generic_Renaming_Declaration
3534 and then Nkind (Name (N)) = N_Expanded_Name
3535 and then Is_Generic_Instance (Entity (Prefix (Name (N))))
3536 and then Is_Generic_Unit (Old_E)
3539 ("renamed generic unit must be a library unit", Name (N));
3541 elsif Is_Package_Or_Generic_Package (Old_E) then
3543 -- Inherit categorization flags
3545 New_E := Defining_Entity (N);
3546 Set_Is_Pure (New_E, Is_Pure (Old_E));
3547 Set_Is_Preelaborated (New_E, Is_Preelaborated (Old_E));
3548 Set_Is_Remote_Call_Interface (New_E,
3549 Is_Remote_Call_Interface (Old_E));
3550 Set_Is_Remote_Types (New_E, Is_Remote_Types (Old_E));
3551 Set_Is_Shared_Passive (New_E, Is_Shared_Passive (Old_E));
3553 end Check_Library_Unit_Renaming;
3559 procedure End_Scope is
3565 Id := First_Entity (Current_Scope);
3566 while Present (Id) loop
3567 -- An entity in the current scope is not necessarily the first one
3568 -- on its homonym chain. Find its predecessor if any,
3569 -- If it is an internal entity, it will not be in the visibility
3570 -- chain altogether, and there is nothing to unchain.
3572 if Id /= Current_Entity (Id) then
3573 Prev := Current_Entity (Id);
3574 while Present (Prev)
3575 and then Present (Homonym (Prev))
3576 and then Homonym (Prev) /= Id
3578 Prev := Homonym (Prev);
3581 -- Skip to end of loop if Id is not in the visibility chain
3583 if No (Prev) or else Homonym (Prev) /= Id then
3591 Set_Is_Immediately_Visible (Id, False);
3593 Outer := Homonym (Id);
3594 while Present (Outer) and then Scope (Outer) = Current_Scope loop
3595 Outer := Homonym (Outer);
3598 -- Reset homonym link of other entities, but do not modify link
3599 -- between entities in current scope, so that the back-end can have
3600 -- a proper count of local overloadings.
3603 Set_Name_Entity_Id (Chars (Id), Outer);
3605 elsif Scope (Prev) /= Scope (Id) then
3606 Set_Homonym (Prev, Outer);
3613 -- If the scope generated freeze actions, place them before the
3614 -- current declaration and analyze them. Type declarations and
3615 -- the bodies of initialization procedures can generate such nodes.
3616 -- We follow the parent chain until we reach a list node, which is
3617 -- the enclosing list of declarations. If the list appears within
3618 -- a protected definition, move freeze nodes outside the protected
3622 (Scope_Stack.Table (Scope_Stack.Last).Pending_Freeze_Actions)
3626 L : constant List_Id := Scope_Stack.Table
3627 (Scope_Stack.Last).Pending_Freeze_Actions;
3630 if Is_Itype (Current_Scope) then
3631 Decl := Associated_Node_For_Itype (Current_Scope);
3633 Decl := Parent (Current_Scope);
3638 while not (Is_List_Member (Decl))
3639 or else Nkind_In (Parent (Decl), N_Protected_Definition,
3642 Decl := Parent (Decl);
3645 Insert_List_Before_And_Analyze (Decl, L);
3654 ---------------------
3655 -- End_Use_Clauses --
3656 ---------------------
3658 procedure End_Use_Clauses (Clause : Node_Id) is
3662 -- Remove Use_Type clauses first, because they affect the
3663 -- visibility of operators in subsequent used packages.
3666 while Present (U) loop
3667 if Nkind (U) = N_Use_Type_Clause then
3671 Next_Use_Clause (U);
3675 while Present (U) loop
3676 if Nkind (U) = N_Use_Package_Clause then
3677 End_Use_Package (U);
3680 Next_Use_Clause (U);
3682 end End_Use_Clauses;
3684 ---------------------
3685 -- End_Use_Package --
3686 ---------------------
3688 procedure End_Use_Package (N : Node_Id) is
3689 Pack_Name : Node_Id;
3694 function Is_Primitive_Operator_In_Use
3696 F : Entity_Id) return Boolean;
3697 -- Check whether Op is a primitive operator of a use-visible type
3699 ----------------------------------
3700 -- Is_Primitive_Operator_In_Use --
3701 ----------------------------------
3703 function Is_Primitive_Operator_In_Use
3705 F : Entity_Id) return Boolean
3707 T : constant Entity_Id := Base_Type (Etype (F));
3709 return In_Use (T) and then Scope (T) = Scope (Op);
3710 end Is_Primitive_Operator_In_Use;
3712 -- Start of processing for End_Use_Package
3715 Pack_Name := First (Names (N));
3716 while Present (Pack_Name) loop
3718 -- Test that Pack_Name actually denotes a package before processing
3720 if Is_Entity_Name (Pack_Name)
3721 and then Ekind (Entity (Pack_Name)) = E_Package
3723 Pack := Entity (Pack_Name);
3725 if In_Open_Scopes (Pack) then
3728 elsif not Redundant_Use (Pack_Name) then
3729 Set_In_Use (Pack, False);
3730 Set_Current_Use_Clause (Pack, Empty);
3732 Id := First_Entity (Pack);
3733 while Present (Id) loop
3735 -- Preserve use-visibility of operators that are primitive
3736 -- operators of a type that is use-visible through an active
3739 if Nkind (Id) = N_Defining_Operator_Symbol
3741 (Is_Primitive_Operator_In_Use
3742 (Id, First_Formal (Id))
3744 (Present (Next_Formal (First_Formal (Id)))
3746 Is_Primitive_Operator_In_Use
3747 (Id, Next_Formal (First_Formal (Id)))))
3752 Set_Is_Potentially_Use_Visible (Id, False);
3755 if Is_Private_Type (Id)
3756 and then Present (Full_View (Id))
3758 Set_Is_Potentially_Use_Visible (Full_View (Id), False);
3764 if Present (Renamed_Object (Pack)) then
3765 Set_In_Use (Renamed_Object (Pack), False);
3766 Set_Current_Use_Clause (Renamed_Object (Pack), Empty);
3769 if Chars (Pack) = Name_System
3770 and then Scope (Pack) = Standard_Standard
3771 and then Present_System_Aux
3773 Id := First_Entity (System_Aux_Id);
3774 while Present (Id) loop
3775 Set_Is_Potentially_Use_Visible (Id, False);
3777 if Is_Private_Type (Id)
3778 and then Present (Full_View (Id))
3780 Set_Is_Potentially_Use_Visible (Full_View (Id), False);
3786 Set_In_Use (System_Aux_Id, False);
3790 Set_Redundant_Use (Pack_Name, False);
3797 if Present (Hidden_By_Use_Clause (N)) then
3798 Elmt := First_Elmt (Hidden_By_Use_Clause (N));
3799 while Present (Elmt) loop
3801 E : constant Entity_Id := Node (Elmt);
3804 -- Reset either Use_Visibility or Direct_Visibility, depending
3805 -- on how the entity was hidden by the use clause.
3807 if In_Use (Scope (E))
3808 and then Used_As_Generic_Actual (Scope (E))
3810 Set_Is_Potentially_Use_Visible (Node (Elmt));
3812 Set_Is_Immediately_Visible (Node (Elmt));
3819 Set_Hidden_By_Use_Clause (N, No_Elist);
3821 end End_Use_Package;
3827 procedure End_Use_Type (N : Node_Id) is
3832 -- Start of processing for End_Use_Type
3835 Id := First (Subtype_Marks (N));
3836 while Present (Id) loop
3838 -- A call to Rtsfind may occur while analyzing a use_type clause,
3839 -- in which case the type marks are not resolved yet, and there is
3840 -- nothing to remove.
3842 if not Is_Entity_Name (Id) or else No (Entity (Id)) then
3848 if T = Any_Type or else From_With_Type (T) then
3851 -- Note that the use_type clause may mention a subtype of the type
3852 -- whose primitive operations have been made visible. Here as
3853 -- elsewhere, it is the base type that matters for visibility.
3855 elsif In_Open_Scopes (Scope (Base_Type (T))) then
3858 elsif not Redundant_Use (Id) then
3859 Set_In_Use (T, False);
3860 Set_In_Use (Base_Type (T), False);
3861 Set_Current_Use_Clause (T, Empty);
3862 Set_Current_Use_Clause (Base_Type (T), Empty);
3869 if Is_Empty_Elmt_List (Used_Operations (N)) then
3873 Elmt := First_Elmt (Used_Operations (N));
3874 while Present (Elmt) loop
3875 Set_Is_Potentially_Use_Visible (Node (Elmt), False);
3881 ----------------------
3882 -- Find_Direct_Name --
3883 ----------------------
3885 procedure Find_Direct_Name (N : Node_Id) is
3890 Inst : Entity_Id := Empty;
3891 -- Enclosing instance, if any
3893 Homonyms : Entity_Id;
3894 -- Saves start of homonym chain
3896 Nvis_Entity : Boolean;
3897 -- Set True to indicate that there is at least one entity on the homonym
3898 -- chain which, while not visible, is visible enough from the user point
3899 -- of view to warrant an error message of "not visible" rather than
3902 Nvis_Is_Private_Subprg : Boolean := False;
3903 -- Ada 2005 (AI-262): Set True to indicate that a form of Beaujolais
3904 -- effect concerning library subprograms has been detected. Used to
3905 -- generate the precise error message.
3907 function From_Actual_Package (E : Entity_Id) return Boolean;
3908 -- Returns true if the entity is declared in a package that is
3909 -- an actual for a formal package of the current instance. Such an
3910 -- entity requires special handling because it may be use-visible
3911 -- but hides directly visible entities defined outside the instance.
3913 function Is_Actual_Parameter return Boolean;
3914 -- This function checks if the node N is an identifier that is an actual
3915 -- parameter of a procedure call. If so it returns True, otherwise it
3916 -- return False. The reason for this check is that at this stage we do
3917 -- not know what procedure is being called if the procedure might be
3918 -- overloaded, so it is premature to go setting referenced flags or
3919 -- making calls to Generate_Reference. We will wait till Resolve_Actuals
3920 -- for that processing
3922 function Known_But_Invisible (E : Entity_Id) return Boolean;
3923 -- This function determines whether the entity E (which is not
3924 -- visible) can reasonably be considered to be known to the writer
3925 -- of the reference. This is a heuristic test, used only for the
3926 -- purposes of figuring out whether we prefer to complain that an
3927 -- entity is undefined or invisible (and identify the declaration
3928 -- of the invisible entity in the latter case). The point here is
3929 -- that we don't want to complain that something is invisible and
3930 -- then point to something entirely mysterious to the writer.
3932 procedure Nvis_Messages;
3933 -- Called if there are no visible entries for N, but there is at least
3934 -- one non-directly visible, or hidden declaration. This procedure
3935 -- outputs an appropriate set of error messages.
3937 procedure Undefined (Nvis : Boolean);
3938 -- This function is called if the current node has no corresponding
3939 -- visible entity or entities. The value set in Msg indicates whether
3940 -- an error message was generated (multiple error messages for the
3941 -- same variable are generally suppressed, see body for details).
3942 -- Msg is True if an error message was generated, False if not. This
3943 -- value is used by the caller to determine whether or not to output
3944 -- additional messages where appropriate. The parameter is set False
3945 -- to get the message "X is undefined", and True to get the message
3946 -- "X is not visible".
3948 -------------------------
3949 -- From_Actual_Package --
3950 -------------------------
3952 function From_Actual_Package (E : Entity_Id) return Boolean is
3953 Scop : constant Entity_Id := Scope (E);
3957 if not In_Instance then
3960 Inst := Current_Scope;
3961 while Present (Inst)
3962 and then Ekind (Inst) /= E_Package
3963 and then not Is_Generic_Instance (Inst)
3965 Inst := Scope (Inst);
3972 Act := First_Entity (Inst);
3973 while Present (Act) loop
3974 if Ekind (Act) = E_Package then
3976 -- Check for end of actuals list
3978 if Renamed_Object (Act) = Inst then
3981 elsif Present (Associated_Formal_Package (Act))
3982 and then Renamed_Object (Act) = Scop
3984 -- Entity comes from (instance of) formal package
3999 end From_Actual_Package;
4001 -------------------------
4002 -- Is_Actual_Parameter --
4003 -------------------------
4005 function Is_Actual_Parameter return Boolean is
4008 Nkind (N) = N_Identifier
4010 (Nkind (Parent (N)) = N_Procedure_Call_Statement
4012 (Nkind (Parent (N)) = N_Parameter_Association
4013 and then N = Explicit_Actual_Parameter (Parent (N))
4014 and then Nkind (Parent (Parent (N))) =
4015 N_Procedure_Call_Statement));
4016 end Is_Actual_Parameter;
4018 -------------------------
4019 -- Known_But_Invisible --
4020 -------------------------
4022 function Known_But_Invisible (E : Entity_Id) return Boolean is
4023 Fname : File_Name_Type;
4026 -- Entities in Standard are always considered to be known
4028 if Sloc (E) <= Standard_Location then
4031 -- An entity that does not come from source is always considered
4032 -- to be unknown, since it is an artifact of code expansion.
4034 elsif not Comes_From_Source (E) then
4037 -- In gnat internal mode, we consider all entities known
4039 elsif GNAT_Mode then
4043 -- Here we have an entity that is not from package Standard, and
4044 -- which comes from Source. See if it comes from an internal file.
4046 Fname := Unit_File_Name (Get_Source_Unit (E));
4048 -- Case of from internal file
4050 if Is_Internal_File_Name (Fname) then
4052 -- Private part entities in internal files are never considered
4053 -- to be known to the writer of normal application code.
4055 if Is_Hidden (E) then
4059 -- Entities from System packages other than System and
4060 -- System.Storage_Elements are not considered to be known.
4061 -- System.Auxxxx files are also considered known to the user.
4063 -- Should refine this at some point to generally distinguish
4064 -- between known and unknown internal files ???
4066 Get_Name_String (Fname);
4071 Name_Buffer (1 .. 2) /= "s-"
4073 Name_Buffer (3 .. 8) = "stoele"
4075 Name_Buffer (3 .. 5) = "aux";
4077 -- If not an internal file, then entity is definitely known,
4078 -- even if it is in a private part (the message generated will
4079 -- note that it is in a private part)
4084 end Known_But_Invisible;
4090 procedure Nvis_Messages is
4091 Comp_Unit : Node_Id;
4093 Found : Boolean := False;
4094 Hidden : Boolean := False;
4098 -- Ada 2005 (AI-262): Generate a precise error concerning the
4099 -- Beaujolais effect that was previously detected
4101 if Nvis_Is_Private_Subprg then
4103 pragma Assert (Nkind (E2) = N_Defining_Identifier
4104 and then Ekind (E2) = E_Function
4105 and then Scope (E2) = Standard_Standard
4106 and then Has_Private_With (E2));
4108 -- Find the sloc corresponding to the private with'ed unit
4110 Comp_Unit := Cunit (Current_Sem_Unit);
4111 Error_Msg_Sloc := No_Location;
4113 Item := First (Context_Items (Comp_Unit));
4114 while Present (Item) loop
4115 if Nkind (Item) = N_With_Clause
4116 and then Private_Present (Item)
4117 and then Entity (Name (Item)) = E2
4119 Error_Msg_Sloc := Sloc (Item);
4126 pragma Assert (Error_Msg_Sloc /= No_Location);
4128 Error_Msg_N ("(Ada 2005): hidden by private with clause #", N);
4132 Undefined (Nvis => True);
4136 -- First loop does hidden declarations
4139 while Present (Ent) loop
4140 if Is_Potentially_Use_Visible (Ent) then
4142 Error_Msg_N -- CODEFIX
4143 ("multiple use clauses cause hiding!", N);
4147 Error_Msg_Sloc := Sloc (Ent);
4148 Error_Msg_N -- CODEFIX
4149 ("hidden declaration#!", N);
4152 Ent := Homonym (Ent);
4155 -- If we found hidden declarations, then that's enough, don't
4156 -- bother looking for non-visible declarations as well.
4162 -- Second loop does non-directly visible declarations
4165 while Present (Ent) loop
4166 if not Is_Potentially_Use_Visible (Ent) then
4168 -- Do not bother the user with unknown entities
4170 if not Known_But_Invisible (Ent) then
4174 Error_Msg_Sloc := Sloc (Ent);
4176 -- Output message noting that there is a non-visible
4177 -- declaration, distinguishing the private part case.
4179 if Is_Hidden (Ent) then
4180 Error_Msg_N ("non-visible (private) declaration#!", N);
4182 -- If the entity is declared in a generic package, it
4183 -- cannot be visible, so there is no point in adding it
4184 -- to the list of candidates if another homograph from a
4185 -- non-generic package has been seen.
4187 elsif Ekind (Scope (Ent)) = E_Generic_Package
4193 Error_Msg_N -- CODEFIX
4194 ("non-visible declaration#!", N);
4196 if Ekind (Scope (Ent)) /= E_Generic_Package then
4200 if Is_Compilation_Unit (Ent)
4202 Nkind (Parent (Parent (N))) = N_Use_Package_Clause
4204 Error_Msg_Qual_Level := 99;
4205 Error_Msg_NE -- CODEFIX
4206 ("\\missing `WITH &;`", N, Ent);
4207 Error_Msg_Qual_Level := 0;
4210 if Ekind (Ent) = E_Discriminant
4211 and then Present (Corresponding_Discriminant (Ent))
4212 and then Scope (Corresponding_Discriminant (Ent)) =
4216 ("inherited discriminant not allowed here" &
4217 " (RM 3.8 (12), 3.8.1 (6))!", N);
4221 -- Set entity and its containing package as referenced. We
4222 -- can't be sure of this, but this seems a better choice
4223 -- to avoid unused entity messages.
4225 if Comes_From_Source (Ent) then
4226 Set_Referenced (Ent);
4227 Set_Referenced (Cunit_Entity (Get_Source_Unit (Ent)));
4232 Ent := Homonym (Ent);
4241 procedure Undefined (Nvis : Boolean) is
4242 Emsg : Error_Msg_Id;
4245 -- We should never find an undefined internal name. If we do, then
4246 -- see if we have previous errors. If so, ignore on the grounds that
4247 -- it is probably a cascaded message (e.g. a block label from a badly
4248 -- formed block). If no previous errors, then we have a real internal
4249 -- error of some kind so raise an exception.
4251 if Is_Internal_Name (Chars (N)) then
4252 if Total_Errors_Detected /= 0 then
4255 raise Program_Error;
4259 -- A very specialized error check, if the undefined variable is
4260 -- a case tag, and the case type is an enumeration type, check
4261 -- for a possible misspelling, and if so, modify the identifier
4263 -- Named aggregate should also be handled similarly ???
4265 if Nkind (N) = N_Identifier
4266 and then Nkind (Parent (N)) = N_Case_Statement_Alternative
4269 Case_Stm : constant Node_Id := Parent (Parent (N));
4270 Case_Typ : constant Entity_Id := Etype (Expression (Case_Stm));
4275 if Is_Enumeration_Type (Case_Typ)
4276 and then not Is_Standard_Character_Type (Case_Typ)
4278 Lit := First_Literal (Case_Typ);
4279 Get_Name_String (Chars (Lit));
4281 if Chars (Lit) /= Chars (N)
4282 and then Is_Bad_Spelling_Of (Chars (N), Chars (Lit)) then
4283 Error_Msg_Node_2 := Lit;
4284 Error_Msg_N -- CODEFIX
4285 ("& is undefined, assume misspelling of &", N);
4286 Rewrite (N, New_Occurrence_Of (Lit, Sloc (N)));
4290 Lit := Next_Literal (Lit);
4295 -- Normal processing
4297 Set_Entity (N, Any_Id);
4298 Set_Etype (N, Any_Type);
4300 -- We use the table Urefs to keep track of entities for which we
4301 -- have issued errors for undefined references. Multiple errors
4302 -- for a single name are normally suppressed, however we modify
4303 -- the error message to alert the programmer to this effect.
4305 for J in Urefs.First .. Urefs.Last loop
4306 if Chars (N) = Chars (Urefs.Table (J).Node) then
4307 if Urefs.Table (J).Err /= No_Error_Msg
4308 and then Sloc (N) /= Urefs.Table (J).Loc
4310 Error_Msg_Node_1 := Urefs.Table (J).Node;
4312 if Urefs.Table (J).Nvis then
4313 Change_Error_Text (Urefs.Table (J).Err,
4314 "& is not visible (more references follow)");
4316 Change_Error_Text (Urefs.Table (J).Err,
4317 "& is undefined (more references follow)");
4320 Urefs.Table (J).Err := No_Error_Msg;
4323 -- Although we will set Msg False, and thus suppress the
4324 -- message, we also set Error_Posted True, to avoid any
4325 -- cascaded messages resulting from the undefined reference.
4328 Set_Error_Posted (N, True);
4333 -- If entry not found, this is first undefined occurrence
4336 Error_Msg_N ("& is not visible!", N);
4340 Error_Msg_N ("& is undefined!", N);
4343 -- A very bizarre special check, if the undefined identifier
4344 -- is put or put_line, then add a special error message (since
4345 -- this is a very common error for beginners to make).
4347 if Chars (N) = Name_Put or else Chars (N) = Name_Put_Line then
4348 Error_Msg_N -- CODEFIX
4349 ("\\possible missing `WITH Ada.Text_'I'O; " &
4350 "USE Ada.Text_'I'O`!", N);
4352 -- Another special check if N is the prefix of a selected
4353 -- component which is a known unit, add message complaining
4354 -- about missing with for this unit.
4356 elsif Nkind (Parent (N)) = N_Selected_Component
4357 and then N = Prefix (Parent (N))
4358 and then Is_Known_Unit (Parent (N))
4360 Error_Msg_Node_2 := Selector_Name (Parent (N));
4361 Error_Msg_N -- CODEFIX
4362 ("\\missing `WITH &.&;`", Prefix (Parent (N)));
4365 -- Now check for possible misspellings
4369 Ematch : Entity_Id := Empty;
4371 Last_Name_Id : constant Name_Id :=
4372 Name_Id (Nat (First_Name_Id) +
4373 Name_Entries_Count - 1);
4376 for Nam in First_Name_Id .. Last_Name_Id loop
4377 E := Get_Name_Entity_Id (Nam);
4380 and then (Is_Immediately_Visible (E)
4382 Is_Potentially_Use_Visible (E))
4384 if Is_Bad_Spelling_Of (Chars (N), Nam) then
4391 if Present (Ematch) then
4392 Error_Msg_NE -- CODEFIX
4393 ("\possible misspelling of&", N, Ematch);
4398 -- Make entry in undefined references table unless the full errors
4399 -- switch is set, in which case by refraining from generating the
4400 -- table entry, we guarantee that we get an error message for every
4401 -- undefined reference.
4403 if not All_Errors_Mode then
4414 -- Start of processing for Find_Direct_Name
4417 -- If the entity pointer is already set, this is an internal node, or
4418 -- a node that is analyzed more than once, after a tree modification.
4419 -- In such a case there is no resolution to perform, just set the type.
4421 if Present (Entity (N)) then
4422 if Is_Type (Entity (N)) then
4423 Set_Etype (N, Entity (N));
4427 Entyp : constant Entity_Id := Etype (Entity (N));
4430 -- One special case here. If the Etype field is already set,
4431 -- and references the packed array type corresponding to the
4432 -- etype of the referenced entity, then leave it alone. This
4433 -- happens for trees generated from Exp_Pakd, where expressions
4434 -- can be deliberately "mis-typed" to the packed array type.
4436 if Is_Array_Type (Entyp)
4437 and then Is_Packed (Entyp)
4438 and then Present (Etype (N))
4439 and then Etype (N) = Packed_Array_Type (Entyp)
4443 -- If not that special case, then just reset the Etype
4446 Set_Etype (N, Etype (Entity (N)));
4454 -- Here if Entity pointer was not set, we need full visibility analysis
4455 -- First we generate debugging output if the debug E flag is set.
4457 if Debug_Flag_E then
4458 Write_Str ("Looking for ");
4459 Write_Name (Chars (N));
4463 Homonyms := Current_Entity (N);
4464 Nvis_Entity := False;
4467 while Present (E) loop
4469 -- If entity is immediately visible or potentially use visible, then
4470 -- process the entity and we are done.
4472 if Is_Immediately_Visible (E) then
4473 goto Immediately_Visible_Entity;
4475 elsif Is_Potentially_Use_Visible (E) then
4476 goto Potentially_Use_Visible_Entity;
4478 -- Note if a known but invisible entity encountered
4480 elsif Known_But_Invisible (E) then
4481 Nvis_Entity := True;
4484 -- Move to next entity in chain and continue search
4489 -- If no entries on homonym chain that were potentially visible,
4490 -- and no entities reasonably considered as non-visible, then
4491 -- we have a plain undefined reference, with no additional
4492 -- explanation required!
4494 if not Nvis_Entity then
4495 Undefined (Nvis => False);
4497 -- Otherwise there is at least one entry on the homonym chain that
4498 -- is reasonably considered as being known and non-visible.
4506 -- Processing for a potentially use visible entry found. We must search
4507 -- the rest of the homonym chain for two reasons. First, if there is a
4508 -- directly visible entry, then none of the potentially use-visible
4509 -- entities are directly visible (RM 8.4(10)). Second, we need to check
4510 -- for the case of multiple potentially use-visible entries hiding one
4511 -- another and as a result being non-directly visible (RM 8.4(11)).
4513 <<Potentially_Use_Visible_Entity>> declare
4514 Only_One_Visible : Boolean := True;
4515 All_Overloadable : Boolean := Is_Overloadable (E);
4519 while Present (E2) loop
4520 if Is_Immediately_Visible (E2) then
4522 -- If the use-visible entity comes from the actual for a
4523 -- formal package, it hides a directly visible entity from
4524 -- outside the instance.
4526 if From_Actual_Package (E)
4527 and then Scope_Depth (E2) < Scope_Depth (Inst)
4532 goto Immediately_Visible_Entity;
4535 elsif Is_Potentially_Use_Visible (E2) then
4536 Only_One_Visible := False;
4537 All_Overloadable := All_Overloadable and Is_Overloadable (E2);
4539 -- Ada 2005 (AI-262): Protect against a form of Beaujolais effect
4540 -- that can occur in private_with clauses. Example:
4543 -- private with B; package A is
4544 -- package C is function B return Integer;
4546 -- V1 : Integer := B;
4547 -- private function B return Integer;
4548 -- V2 : Integer := B;
4551 -- V1 resolves to A.B, but V2 resolves to library unit B
4553 elsif Ekind (E2) = E_Function
4554 and then Scope (E2) = Standard_Standard
4555 and then Has_Private_With (E2)
4557 Only_One_Visible := False;
4558 All_Overloadable := False;
4559 Nvis_Is_Private_Subprg := True;
4566 -- On falling through this loop, we have checked that there are no
4567 -- immediately visible entities. Only_One_Visible is set if exactly
4568 -- one potentially use visible entity exists. All_Overloadable is
4569 -- set if all the potentially use visible entities are overloadable.
4570 -- The condition for legality is that either there is one potentially
4571 -- use visible entity, or if there is more than one, then all of them
4572 -- are overloadable.
4574 if Only_One_Visible or All_Overloadable then
4577 -- If there is more than one potentially use-visible entity and at
4578 -- least one of them non-overloadable, we have an error (RM 8.4(11).
4579 -- Note that E points to the first such entity on the homonym list.
4580 -- Special case: if one of the entities is declared in an actual
4581 -- package, it was visible in the generic, and takes precedence over
4582 -- other entities that are potentially use-visible. Same if it is
4583 -- declared in a local instantiation of the current instance.
4588 -- Find current instance
4590 Inst := Current_Scope;
4591 while Present (Inst)
4592 and then Inst /= Standard_Standard
4594 if Is_Generic_Instance (Inst) then
4598 Inst := Scope (Inst);
4602 while Present (E2) loop
4603 if From_Actual_Package (E2)
4605 (Is_Generic_Instance (Scope (E2))
4606 and then Scope_Depth (Scope (E2)) > Scope_Depth (Inst))
4619 Is_Predefined_File_Name (Unit_File_Name (Current_Sem_Unit))
4621 -- A use-clause in the body of a system file creates conflict
4622 -- with some entity in a user scope, while rtsfind is active.
4623 -- Keep only the entity coming from another predefined unit.
4626 while Present (E2) loop
4627 if Is_Predefined_File_Name
4628 (Unit_File_Name (Get_Source_Unit (Sloc (E2))))
4637 -- Entity must exist because predefined unit is correct
4639 raise Program_Error;
4648 -- Come here with E set to the first immediately visible entity on
4649 -- the homonym chain. This is the one we want unless there is another
4650 -- immediately visible entity further on in the chain for an inner
4651 -- scope (RM 8.3(8)).
4653 <<Immediately_Visible_Entity>> declare
4658 -- Find scope level of initial entity. When compiling through
4659 -- Rtsfind, the previous context is not completely invisible, and
4660 -- an outer entity may appear on the chain, whose scope is below
4661 -- the entry for Standard that delimits the current scope stack.
4662 -- Indicate that the level for this spurious entry is outside of
4663 -- the current scope stack.
4665 Level := Scope_Stack.Last;
4667 Scop := Scope_Stack.Table (Level).Entity;
4668 exit when Scop = Scope (E);
4670 exit when Scop = Standard_Standard;
4673 -- Now search remainder of homonym chain for more inner entry
4674 -- If the entity is Standard itself, it has no scope, and we
4675 -- compare it with the stack entry directly.
4678 while Present (E2) loop
4679 if Is_Immediately_Visible (E2) then
4681 -- If a generic package contains a local declaration that
4682 -- has the same name as the generic, there may be a visibility
4683 -- conflict in an instance, where the local declaration must
4684 -- also hide the name of the corresponding package renaming.
4685 -- We check explicitly for a package declared by a renaming,
4686 -- whose renamed entity is an instance that is on the scope
4687 -- stack, and that contains a homonym in the same scope. Once
4688 -- we have found it, we know that the package renaming is not
4689 -- immediately visible, and that the identifier denotes the
4690 -- other entity (and its homonyms if overloaded).
4692 if Scope (E) = Scope (E2)
4693 and then Ekind (E) = E_Package
4694 and then Present (Renamed_Object (E))
4695 and then Is_Generic_Instance (Renamed_Object (E))
4696 and then In_Open_Scopes (Renamed_Object (E))
4697 and then Comes_From_Source (N)
4699 Set_Is_Immediately_Visible (E, False);
4703 for J in Level + 1 .. Scope_Stack.Last loop
4704 if Scope_Stack.Table (J).Entity = Scope (E2)
4705 or else Scope_Stack.Table (J).Entity = E2
4718 -- At the end of that loop, E is the innermost immediately
4719 -- visible entity, so we are all set.
4722 -- Come here with entity found, and stored in E
4726 -- Check violation of No_Wide_Characters restriction
4728 Check_Wide_Character_Restriction (E, N);
4730 -- When distribution features are available (Get_PCS_Name /=
4731 -- Name_No_DSA), a remote access-to-subprogram type is converted
4732 -- into a record type holding whatever information is needed to
4733 -- perform a remote call on an RCI subprogram. In that case we
4734 -- rewrite any occurrence of the RAS type into the equivalent record
4735 -- type here. 'Access attribute references and RAS dereferences are
4736 -- then implemented using specific TSSs. However when distribution is
4737 -- not available (case of Get_PCS_Name = Name_No_DSA), we bypass the
4738 -- generation of these TSSs, and we must keep the RAS type in its
4739 -- original access-to-subprogram form (since all calls through a
4740 -- value of such type will be local anyway in the absence of a PCS).
4742 if Comes_From_Source (N)
4743 and then Is_Remote_Access_To_Subprogram_Type (E)
4744 and then Expander_Active
4745 and then Get_PCS_Name /= Name_No_DSA
4748 New_Occurrence_Of (Equivalent_Type (E), Sloc (N)));
4752 -- Set the entity. Note that the reason we call Set_Entity for the
4753 -- overloadable case, as opposed to Set_Entity_With_Style_Check is
4754 -- that in the overloaded case, the initial call can set the wrong
4755 -- homonym. The call that sets the right homonym is in Sem_Res and
4756 -- that call does use Set_Entity_With_Style_Check, so we don't miss
4759 if Is_Overloadable (E) then
4762 Set_Entity_With_Style_Check (N, E);
4768 Set_Etype (N, Get_Full_View (Etype (E)));
4771 if Debug_Flag_E then
4772 Write_Str (" found ");
4773 Write_Entity_Info (E, " ");
4776 -- If the Ekind of the entity is Void, it means that all homonyms
4777 -- are hidden from all visibility (RM 8.3(5,14-20)). However, this
4778 -- test is skipped if the current scope is a record and the name is
4779 -- a pragma argument expression (case of Atomic and Volatile pragmas
4780 -- and possibly other similar pragmas added later, which are allowed
4781 -- to reference components in the current record).
4783 if Ekind (E) = E_Void
4785 (not Is_Record_Type (Current_Scope)
4786 or else Nkind (Parent (N)) /= N_Pragma_Argument_Association)
4788 Premature_Usage (N);
4790 -- If the entity is overloadable, collect all interpretations of the
4791 -- name for subsequent overload resolution. We optimize a bit here to
4792 -- do this only if we have an overloadable entity that is not on its
4793 -- own on the homonym chain.
4795 elsif Is_Overloadable (E)
4796 and then (Present (Homonym (E)) or else Current_Entity (N) /= E)
4798 Collect_Interps (N);
4800 -- If no homonyms were visible, the entity is unambiguous
4802 if not Is_Overloaded (N) then
4803 if not Is_Actual_Parameter then
4804 Generate_Reference (E, N);
4808 -- Case of non-overloadable entity, set the entity providing that
4809 -- we do not have the case of a discriminant reference within a
4810 -- default expression. Such references are replaced with the
4811 -- corresponding discriminal, which is the formal corresponding to
4812 -- to the discriminant in the initialization procedure.
4815 -- Entity is unambiguous, indicate that it is referenced here
4817 -- For a renaming of an object, always generate simple reference,
4818 -- we don't try to keep track of assignments in this case.
4820 if Is_Object (E) and then Present (Renamed_Object (E)) then
4821 Generate_Reference (E, N);
4823 -- If the renamed entity is a private protected component,
4824 -- reference the original component as well. This needs to be
4825 -- done because the private renamings are installed before any
4826 -- analysis has occurred. Reference to a private component will
4827 -- resolve to the renaming and the original component will be
4828 -- left unreferenced, hence the following.
4830 if Is_Prival (E) then
4831 Generate_Reference (Prival_Link (E), N);
4834 -- One odd case is that we do not want to set the Referenced flag
4835 -- if the entity is a label, and the identifier is the label in
4836 -- the source, since this is not a reference from the point of
4837 -- view of the user.
4839 elsif Nkind (Parent (N)) = N_Label then
4841 R : constant Boolean := Referenced (E);
4844 -- Generate reference unless this is an actual parameter
4845 -- (see comment below)
4847 if Is_Actual_Parameter then
4848 Generate_Reference (E, N);
4849 Set_Referenced (E, R);
4853 -- Normal case, not a label: generate reference
4855 -- ??? It is too early to generate a reference here even if the
4856 -- entity is unambiguous, because the tree is not sufficiently
4857 -- typed at this point for Generate_Reference to determine
4858 -- whether this reference modifies the denoted object (because
4859 -- implicit dereferences cannot be identified prior to full type
4862 -- The Is_Actual_Parameter routine takes care of one of these
4863 -- cases but there are others probably ???
4865 -- If the entity is the LHS of an assignment, and is a variable
4866 -- (rather than a package prefix), we can mark it as a
4867 -- modification right away, to avoid duplicate references.
4870 if not Is_Actual_Parameter then
4872 and then Ekind (E) /= E_Package
4873 and then Ekind (E) /= E_Generic_Package
4875 Generate_Reference (E, N, 'm');
4877 Generate_Reference (E, N);
4881 Check_Nested_Access (E);
4884 Set_Entity_Or_Discriminal (N, E);
4886 if Ada_Version >= Ada_2012
4888 (Nkind (Parent (N)) in N_Subexpr
4889 or else Nkind (Parent (N)) = N_Object_Declaration)
4891 Check_Implicit_Dereference (N, Etype (E));
4895 end Find_Direct_Name;
4897 ------------------------
4898 -- Find_Expanded_Name --
4899 ------------------------
4901 -- This routine searches the homonym chain of the entity until it finds
4902 -- an entity declared in the scope denoted by the prefix. If the entity
4903 -- is private, it may nevertheless be immediately visible, if we are in
4904 -- the scope of its declaration.
4906 procedure Find_Expanded_Name (N : Node_Id) is
4907 Selector : constant Node_Id := Selector_Name (N);
4908 Candidate : Entity_Id := Empty;
4914 P_Name := Entity (Prefix (N));
4917 -- If the prefix is a renamed package, look for the entity in the
4918 -- original package.
4920 if Ekind (P_Name) = E_Package
4921 and then Present (Renamed_Object (P_Name))
4923 P_Name := Renamed_Object (P_Name);
4925 -- Rewrite node with entity field pointing to renamed object
4927 Rewrite (Prefix (N), New_Copy (Prefix (N)));
4928 Set_Entity (Prefix (N), P_Name);
4930 -- If the prefix is an object of a concurrent type, look for
4931 -- the entity in the associated task or protected type.
4933 elsif Is_Concurrent_Type (Etype (P_Name)) then
4934 P_Name := Etype (P_Name);
4937 Id := Current_Entity (Selector);
4940 Is_New_Candidate : Boolean;
4943 while Present (Id) loop
4944 if Scope (Id) = P_Name then
4946 Is_New_Candidate := True;
4948 -- Ada 2005 (AI-217): Handle shadow entities associated with types
4949 -- declared in limited-withed nested packages. We don't need to
4950 -- handle E_Incomplete_Subtype entities because the entities in
4951 -- the limited view are always E_Incomplete_Type entities (see
4952 -- Build_Limited_Views). Regarding the expression used to evaluate
4953 -- the scope, it is important to note that the limited view also
4954 -- has shadow entities associated nested packages. For this reason
4955 -- the correct scope of the entity is the scope of the real entity
4956 -- The non-limited view may itself be incomplete, in which case
4957 -- get the full view if available.
4959 elsif From_With_Type (Id)
4960 and then Is_Type (Id)
4961 and then Ekind (Id) = E_Incomplete_Type
4962 and then Present (Non_Limited_View (Id))
4963 and then Scope (Non_Limited_View (Id)) = P_Name
4965 Candidate := Get_Full_View (Non_Limited_View (Id));
4966 Is_New_Candidate := True;
4969 Is_New_Candidate := False;
4972 if Is_New_Candidate then
4973 if Is_Child_Unit (Id) then
4974 exit when Is_Visible_Child_Unit (Id)
4975 or else Is_Immediately_Visible (Id);
4978 exit when not Is_Hidden (Id)
4979 or else Is_Immediately_Visible (Id);
4988 and then (Ekind (P_Name) = E_Procedure
4990 Ekind (P_Name) = E_Function)
4991 and then Is_Generic_Instance (P_Name)
4993 -- Expanded name denotes entity in (instance of) generic subprogram.
4994 -- The entity may be in the subprogram instance, or may denote one of
4995 -- the formals, which is declared in the enclosing wrapper package.
4997 P_Name := Scope (P_Name);
4999 Id := Current_Entity (Selector);
5000 while Present (Id) loop
5001 exit when Scope (Id) = P_Name;
5006 if No (Id) or else Chars (Id) /= Chars (Selector) then
5007 Set_Etype (N, Any_Type);
5009 -- If we are looking for an entity defined in System, try to find it
5010 -- in the child package that may have been provided as an extension
5011 -- to System. The Extend_System pragma will have supplied the name of
5012 -- the extension, which may have to be loaded.
5014 if Chars (P_Name) = Name_System
5015 and then Scope (P_Name) = Standard_Standard
5016 and then Present (System_Extend_Unit)
5017 and then Present_System_Aux (N)
5019 Set_Entity (Prefix (N), System_Aux_Id);
5020 Find_Expanded_Name (N);
5023 elsif Nkind (Selector) = N_Operator_Symbol
5024 and then Has_Implicit_Operator (N)
5026 -- There is an implicit instance of the predefined operator in
5027 -- the given scope. The operator entity is defined in Standard.
5028 -- Has_Implicit_Operator makes the node into an Expanded_Name.
5032 elsif Nkind (Selector) = N_Character_Literal
5033 and then Has_Implicit_Character_Literal (N)
5035 -- If there is no literal defined in the scope denoted by the
5036 -- prefix, the literal may belong to (a type derived from)
5037 -- Standard_Character, for which we have no explicit literals.
5042 -- If the prefix is a single concurrent object, use its name in
5043 -- the error message, rather than that of the anonymous type.
5045 if Is_Concurrent_Type (P_Name)
5046 and then Is_Internal_Name (Chars (P_Name))
5048 Error_Msg_Node_2 := Entity (Prefix (N));
5050 Error_Msg_Node_2 := P_Name;
5053 if P_Name = System_Aux_Id then
5054 P_Name := Scope (P_Name);
5055 Set_Entity (Prefix (N), P_Name);
5058 if Present (Candidate) then
5060 -- If we know that the unit is a child unit we can give a more
5061 -- accurate error message.
5063 if Is_Child_Unit (Candidate) then
5065 -- If the candidate is a private child unit and we are in
5066 -- the visible part of a public unit, specialize the error
5067 -- message. There might be a private with_clause for it,
5068 -- but it is not currently active.
5070 if Is_Private_Descendant (Candidate)
5071 and then Ekind (Current_Scope) = E_Package
5072 and then not In_Private_Part (Current_Scope)
5073 and then not Is_Private_Descendant (Current_Scope)
5075 Error_Msg_N ("private child unit& is not visible here",
5078 -- Normal case where we have a missing with for a child unit
5081 Error_Msg_Qual_Level := 99;
5082 Error_Msg_NE -- CODEFIX
5083 ("missing `WITH &;`", Selector, Candidate);
5084 Error_Msg_Qual_Level := 0;
5087 -- Here we don't know that this is a child unit
5090 Error_Msg_NE ("& is not a visible entity of&", N, Selector);
5094 -- Within the instantiation of a child unit, the prefix may
5095 -- denote the parent instance, but the selector has the name
5096 -- of the original child. Find whether we are within the
5097 -- corresponding instance, and get the proper entity, which
5098 -- can only be an enclosing scope.
5101 and then In_Open_Scopes (P_Name)
5102 and then Is_Generic_Instance (P_Name)
5105 S : Entity_Id := Current_Scope;
5109 for J in reverse 0 .. Scope_Stack.Last loop
5110 S := Scope_Stack.Table (J).Entity;
5112 exit when S = Standard_Standard;
5114 if Ekind_In (S, E_Function,
5118 P := Generic_Parent (Specification
5119 (Unit_Declaration_Node (S)));
5122 and then Chars (Scope (P)) = Chars (O_Name)
5123 and then Chars (P) = Chars (Selector)
5134 -- If this is a selection from Ada, System or Interfaces, then
5135 -- we assume a missing with for the corresponding package.
5137 if Is_Known_Unit (N) then
5138 if not Error_Posted (N) then
5139 Error_Msg_Node_2 := Selector;
5140 Error_Msg_N -- CODEFIX
5141 ("missing `WITH &.&;`", Prefix (N));
5144 -- If this is a selection from a dummy package, then suppress
5145 -- the error message, of course the entity is missing if the
5146 -- package is missing!
5148 elsif Sloc (Error_Msg_Node_2) = No_Location then
5151 -- Here we have the case of an undefined component
5155 -- The prefix may hide a homonym in the context that
5156 -- declares the desired entity. This error can use a
5157 -- specialized message.
5159 if In_Open_Scopes (P_Name)
5160 and then Present (Homonym (P_Name))
5161 and then Is_Compilation_Unit (Homonym (P_Name))
5163 (Is_Immediately_Visible (Homonym (P_Name))
5164 or else Is_Visible_Child_Unit (Homonym (P_Name)))
5167 H : constant Entity_Id := Homonym (P_Name);
5170 Id := First_Entity (H);
5171 while Present (Id) loop
5172 if Chars (Id) = Chars (Selector) then
5173 Error_Msg_Qual_Level := 99;
5174 Error_Msg_Name_1 := Chars (Selector);
5176 ("% not declared in&", N, P_Name);
5178 ("\use fully qualified name starting with"
5179 & " Standard to make& visible", N, H);
5180 Error_Msg_Qual_Level := 0;
5187 -- If not found, standard error message
5189 Error_Msg_NE ("& not declared in&", N, Selector);
5195 Error_Msg_NE ("& not declared in&", N, Selector);
5198 -- Check for misspelling of some entity in prefix
5200 Id := First_Entity (P_Name);
5201 while Present (Id) loop
5202 if Is_Bad_Spelling_Of (Chars (Id), Chars (Selector))
5203 and then not Is_Internal_Name (Chars (Id))
5205 Error_Msg_NE -- CODEFIX
5206 ("possible misspelling of&", Selector, Id);
5213 -- Specialize the message if this may be an instantiation
5214 -- of a child unit that was not mentioned in the context.
5216 if Nkind (Parent (N)) = N_Package_Instantiation
5217 and then Is_Generic_Instance (Entity (Prefix (N)))
5218 and then Is_Compilation_Unit
5219 (Generic_Parent (Parent (Entity (Prefix (N)))))
5221 Error_Msg_Node_2 := Selector;
5222 Error_Msg_N -- CODEFIX
5223 ("\missing `WITH &.&;`", Prefix (N));
5233 if Comes_From_Source (N)
5234 and then Is_Remote_Access_To_Subprogram_Type (Id)
5235 and then Present (Equivalent_Type (Id))
5237 -- If we are not actually generating distribution code (i.e. the
5238 -- current PCS is the dummy non-distributed version), then the
5239 -- Equivalent_Type will be missing, and Id should be treated as
5240 -- a regular access-to-subprogram type.
5242 Id := Equivalent_Type (Id);
5243 Set_Chars (Selector, Chars (Id));
5246 -- Ada 2005 (AI-50217): Check usage of entities in limited withed units
5248 if Ekind (P_Name) = E_Package
5249 and then From_With_Type (P_Name)
5251 if From_With_Type (Id)
5252 or else Is_Type (Id)
5253 or else Ekind (Id) = E_Package
5258 ("limited withed package can only be used to access "
5259 & "incomplete types",
5264 if Is_Task_Type (P_Name)
5265 and then ((Ekind (Id) = E_Entry
5266 and then Nkind (Parent (N)) /= N_Attribute_Reference)
5268 (Ekind (Id) = E_Entry_Family
5270 Nkind (Parent (Parent (N))) /= N_Attribute_Reference))
5272 -- It is an entry call after all, either to the current task (which
5273 -- will deadlock) or to an enclosing task.
5275 Analyze_Selected_Component (N);
5279 Change_Selected_Component_To_Expanded_Name (N);
5281 -- Do style check and generate reference, but skip both steps if this
5282 -- entity has homonyms, since we may not have the right homonym set yet.
5283 -- The proper homonym will be set during the resolve phase.
5285 if Has_Homonym (Id) then
5288 Set_Entity_Or_Discriminal (N, Id);
5291 Generate_Reference (Id, N, 'm');
5293 Generate_Reference (Id, N);
5297 if Is_Type (Id) then
5300 Set_Etype (N, Get_Full_View (Etype (Id)));
5303 -- Check for violation of No_Wide_Characters
5305 Check_Wide_Character_Restriction (Id, N);
5307 -- If the Ekind of the entity is Void, it means that all homonyms are
5308 -- hidden from all visibility (RM 8.3(5,14-20)).
5310 if Ekind (Id) = E_Void then
5311 Premature_Usage (N);
5313 elsif Is_Overloadable (Id)
5314 and then Present (Homonym (Id))
5317 H : Entity_Id := Homonym (Id);
5320 while Present (H) loop
5321 if Scope (H) = Scope (Id)
5324 or else Is_Immediately_Visible (H))
5326 Collect_Interps (N);
5333 -- If an extension of System is present, collect possible explicit
5334 -- overloadings declared in the extension.
5336 if Chars (P_Name) = Name_System
5337 and then Scope (P_Name) = Standard_Standard
5338 and then Present (System_Extend_Unit)
5339 and then Present_System_Aux (N)
5341 H := Current_Entity (Id);
5343 while Present (H) loop
5344 if Scope (H) = System_Aux_Id then
5345 Add_One_Interp (N, H, Etype (H));
5354 if Nkind (Selector_Name (N)) = N_Operator_Symbol
5355 and then Scope (Id) /= Standard_Standard
5357 -- In addition to user-defined operators in the given scope, there
5358 -- may be an implicit instance of the predefined operator. The
5359 -- operator (defined in Standard) is found in Has_Implicit_Operator,
5360 -- and added to the interpretations. Procedure Add_One_Interp will
5361 -- determine which hides which.
5363 if Has_Implicit_Operator (N) then
5367 end Find_Expanded_Name;
5369 -------------------------
5370 -- Find_Renamed_Entity --
5371 -------------------------
5373 function Find_Renamed_Entity
5377 Is_Actual : Boolean := False) return Entity_Id
5380 I1 : Interp_Index := 0; -- Suppress junk warnings
5386 function Enclosing_Instance return Entity_Id;
5387 -- If the renaming determines the entity for the default of a formal
5388 -- subprogram nested within another instance, choose the innermost
5389 -- candidate. This is because if the formal has a box, and we are within
5390 -- an enclosing instance where some candidate interpretations are local
5391 -- to this enclosing instance, we know that the default was properly
5392 -- resolved when analyzing the generic, so we prefer the local
5393 -- candidates to those that are external. This is not always the case
5394 -- but is a reasonable heuristic on the use of nested generics. The
5395 -- proper solution requires a full renaming model.
5397 function Is_Visible_Operation (Op : Entity_Id) return Boolean;
5398 -- If the renamed entity is an implicit operator, check whether it is
5399 -- visible because its operand type is properly visible. This check
5400 -- applies to explicit renamed entities that appear in the source in a
5401 -- renaming declaration or a formal subprogram instance, but not to
5402 -- default generic actuals with a name.
5404 function Report_Overload return Entity_Id;
5405 -- List possible interpretations, and specialize message in the
5406 -- case of a generic actual.
5408 function Within (Inner, Outer : Entity_Id) return Boolean;
5409 -- Determine whether a candidate subprogram is defined within the
5410 -- enclosing instance. If yes, it has precedence over outer candidates.
5412 ------------------------
5413 -- Enclosing_Instance --
5414 ------------------------
5416 function Enclosing_Instance return Entity_Id is
5420 if not Is_Generic_Instance (Current_Scope)
5421 and then not Is_Actual
5426 S := Scope (Current_Scope);
5427 while S /= Standard_Standard loop
5428 if Is_Generic_Instance (S) then
5436 end Enclosing_Instance;
5438 --------------------------
5439 -- Is_Visible_Operation --
5440 --------------------------
5442 function Is_Visible_Operation (Op : Entity_Id) return Boolean is
5448 if Ekind (Op) /= E_Operator
5449 or else Scope (Op) /= Standard_Standard
5450 or else (In_Instance
5453 or else Present (Enclosing_Instance)))
5458 -- For a fixed point type operator, check the resulting type,
5459 -- because it may be a mixed mode integer * fixed operation.
5461 if Present (Next_Formal (First_Formal (New_S)))
5462 and then Is_Fixed_Point_Type (Etype (New_S))
5464 Typ := Etype (New_S);
5466 Typ := Etype (First_Formal (New_S));
5469 Btyp := Base_Type (Typ);
5471 if Nkind (Nam) /= N_Expanded_Name then
5472 return (In_Open_Scopes (Scope (Btyp))
5473 or else Is_Potentially_Use_Visible (Btyp)
5474 or else In_Use (Btyp)
5475 or else In_Use (Scope (Btyp)));
5478 Scop := Entity (Prefix (Nam));
5480 if Ekind (Scop) = E_Package
5481 and then Present (Renamed_Object (Scop))
5483 Scop := Renamed_Object (Scop);
5486 -- Operator is visible if prefix of expanded name denotes
5487 -- scope of type, or else type is defined in System_Aux
5488 -- and the prefix denotes System.
5490 return Scope (Btyp) = Scop
5491 or else (Scope (Btyp) = System_Aux_Id
5492 and then Scope (Scope (Btyp)) = Scop);
5495 end Is_Visible_Operation;
5501 function Within (Inner, Outer : Entity_Id) return Boolean is
5505 Sc := Scope (Inner);
5506 while Sc /= Standard_Standard loop
5517 ---------------------
5518 -- Report_Overload --
5519 ---------------------
5521 function Report_Overload return Entity_Id is
5524 Error_Msg_NE -- CODEFIX
5525 ("ambiguous actual subprogram&, " &
5526 "possible interpretations:", N, Nam);
5528 Error_Msg_N -- CODEFIX
5529 ("ambiguous subprogram, " &
5530 "possible interpretations:", N);
5533 List_Interps (Nam, N);
5535 end Report_Overload;
5537 -- Start of processing for Find_Renamed_Entity
5541 Candidate_Renaming := Empty;
5543 if not Is_Overloaded (Nam) then
5544 if Entity_Matches_Spec (Entity (Nam), New_S) then
5545 Candidate_Renaming := New_S;
5547 if Is_Visible_Operation (Entity (Nam)) then
5548 Old_S := Entity (Nam);
5552 Present (First_Formal (Entity (Nam)))
5553 and then Present (First_Formal (New_S))
5554 and then (Base_Type (Etype (First_Formal (Entity (Nam))))
5555 = Base_Type (Etype (First_Formal (New_S))))
5557 Candidate_Renaming := Entity (Nam);
5561 Get_First_Interp (Nam, Ind, It);
5562 while Present (It.Nam) loop
5563 if Entity_Matches_Spec (It.Nam, New_S)
5564 and then Is_Visible_Operation (It.Nam)
5566 if Old_S /= Any_Id then
5568 -- Note: The call to Disambiguate only happens if a
5569 -- previous interpretation was found, in which case I1
5570 -- has received a value.
5572 It1 := Disambiguate (Nam, I1, Ind, Etype (Old_S));
5574 if It1 = No_Interp then
5575 Inst := Enclosing_Instance;
5577 if Present (Inst) then
5578 if Within (It.Nam, Inst) then
5579 if Within (Old_S, Inst) then
5581 -- Choose the innermost subprogram, which would
5582 -- have hidden the outer one in the generic.
5584 if Scope_Depth (It.Nam) <
5593 elsif Within (Old_S, Inst) then
5597 return Report_Overload;
5600 -- If not within an instance, ambiguity is real
5603 return Report_Overload;
5617 Present (First_Formal (It.Nam))
5618 and then Present (First_Formal (New_S))
5619 and then (Base_Type (Etype (First_Formal (It.Nam)))
5620 = Base_Type (Etype (First_Formal (New_S))))
5622 Candidate_Renaming := It.Nam;
5625 Get_Next_Interp (Ind, It);
5628 Set_Entity (Nam, Old_S);
5630 if Old_S /= Any_Id then
5631 Set_Is_Overloaded (Nam, False);
5636 end Find_Renamed_Entity;
5638 -----------------------------
5639 -- Find_Selected_Component --
5640 -----------------------------
5642 procedure Find_Selected_Component (N : Node_Id) is
5643 P : constant Node_Id := Prefix (N);
5646 -- Entity denoted by prefix
5656 if Nkind (P) = N_Error then
5660 -- Selector name cannot be a character literal or an operator symbol in
5661 -- SPARK, except for the operator symbol in a renaming.
5663 if Restriction_Check_Required (SPARK) then
5664 if Nkind (Selector_Name (N)) = N_Character_Literal then
5665 Check_SPARK_Restriction
5666 ("character literal cannot be prefixed", N);
5667 elsif Nkind (Selector_Name (N)) = N_Operator_Symbol
5668 and then Nkind (Parent (N)) /= N_Subprogram_Renaming_Declaration
5670 Check_SPARK_Restriction ("operator symbol cannot be prefixed", N);
5674 -- If the selector already has an entity, the node has been constructed
5675 -- in the course of expansion, and is known to be valid. Do not verify
5676 -- that it is defined for the type (it may be a private component used
5677 -- in the expansion of record equality).
5679 if Present (Entity (Selector_Name (N))) then
5681 or else Etype (N) = Any_Type
5684 Sel_Name : constant Node_Id := Selector_Name (N);
5685 Selector : constant Entity_Id := Entity (Sel_Name);
5689 Set_Etype (Sel_Name, Etype (Selector));
5691 if not Is_Entity_Name (P) then
5695 -- Build an actual subtype except for the first parameter
5696 -- of an init proc, where this actual subtype is by
5697 -- definition incorrect, since the object is uninitialized
5698 -- (and does not even have defined discriminants etc.)
5700 if Is_Entity_Name (P)
5701 and then Ekind (Entity (P)) = E_Function
5703 Nam := New_Copy (P);
5705 if Is_Overloaded (P) then
5706 Save_Interps (P, Nam);
5710 Make_Function_Call (Sloc (P), Name => Nam));
5712 Analyze_Selected_Component (N);
5715 elsif Ekind (Selector) = E_Component
5716 and then (not Is_Entity_Name (P)
5717 or else Chars (Entity (P)) /= Name_uInit)
5719 -- Do not build the subtype when referencing components of
5720 -- dispatch table wrappers. Required to avoid generating
5721 -- elaboration code with HI runtimes. JVM and .NET use a
5722 -- modified version of Ada.Tags which does not contain RE_
5723 -- Dispatch_Table_Wrapper and RE_No_Dispatch_Table_Wrapper.
5724 -- Avoid raising RE_Not_Available exception in those cases.
5726 if VM_Target = No_VM
5727 and then RTU_Loaded (Ada_Tags)
5729 ((RTE_Available (RE_Dispatch_Table_Wrapper)
5730 and then Scope (Selector) =
5731 RTE (RE_Dispatch_Table_Wrapper))
5733 (RTE_Available (RE_No_Dispatch_Table_Wrapper)
5734 and then Scope (Selector) =
5735 RTE (RE_No_Dispatch_Table_Wrapper)))
5741 Build_Actual_Subtype_Of_Component
5742 (Etype (Selector), N);
5749 if No (C_Etype) then
5750 C_Etype := Etype (Selector);
5752 Insert_Action (N, C_Etype);
5753 C_Etype := Defining_Identifier (C_Etype);
5756 Set_Etype (N, C_Etype);
5759 -- If this is the name of an entry or protected operation, and
5760 -- the prefix is an access type, insert an explicit dereference,
5761 -- so that entry calls are treated uniformly.
5763 if Is_Access_Type (Etype (P))
5764 and then Is_Concurrent_Type (Designated_Type (Etype (P)))
5767 New_P : constant Node_Id :=
5768 Make_Explicit_Dereference (Sloc (P),
5769 Prefix => Relocate_Node (P));
5772 Set_Etype (P, Designated_Type (Etype (Prefix (P))));
5776 -- If the selected component appears within a default expression
5777 -- and it has an actual subtype, the pre-analysis has not yet
5778 -- completed its analysis, because Insert_Actions is disabled in
5779 -- that context. Within the init proc of the enclosing type we
5780 -- must complete this analysis, if an actual subtype was created.
5782 elsif Inside_Init_Proc then
5784 Typ : constant Entity_Id := Etype (N);
5785 Decl : constant Node_Id := Declaration_Node (Typ);
5787 if Nkind (Decl) = N_Subtype_Declaration
5788 and then not Analyzed (Decl)
5789 and then Is_List_Member (Decl)
5790 and then No (Parent (Decl))
5793 Insert_Action (N, Decl);
5800 elsif Is_Entity_Name (P) then
5801 P_Name := Entity (P);
5803 -- The prefix may denote an enclosing type which is the completion
5804 -- of an incomplete type declaration.
5806 if Is_Type (P_Name) then
5807 Set_Entity (P, Get_Full_View (P_Name));
5808 Set_Etype (P, Entity (P));
5809 P_Name := Entity (P);
5812 P_Type := Base_Type (Etype (P));
5814 if Debug_Flag_E then
5815 Write_Str ("Found prefix type to be ");
5816 Write_Entity_Info (P_Type, " "); Write_Eol;
5819 -- First check for components of a record object (not the
5820 -- result of a call, which is handled below).
5822 if Is_Appropriate_For_Record (P_Type)
5823 and then not Is_Overloadable (P_Name)
5824 and then not Is_Type (P_Name)
5826 -- Selected component of record. Type checking will validate
5827 -- name of selector.
5828 -- ??? could we rewrite an implicit dereference into an explicit
5831 Analyze_Selected_Component (N);
5833 -- Reference to type name in predicate/invariant expression
5835 elsif Is_Appropriate_For_Entry_Prefix (P_Type)
5836 and then not In_Open_Scopes (P_Name)
5837 and then (not Is_Concurrent_Type (Etype (P_Name))
5838 or else not In_Open_Scopes (Etype (P_Name)))
5840 -- Call to protected operation or entry. Type checking is
5841 -- needed on the prefix.
5843 Analyze_Selected_Component (N);
5845 elsif (In_Open_Scopes (P_Name)
5846 and then Ekind (P_Name) /= E_Void
5847 and then not Is_Overloadable (P_Name))
5848 or else (Is_Concurrent_Type (Etype (P_Name))
5849 and then In_Open_Scopes (Etype (P_Name)))
5851 -- Prefix denotes an enclosing loop, block, or task, i.e. an
5852 -- enclosing construct that is not a subprogram or accept.
5854 Find_Expanded_Name (N);
5856 elsif Ekind (P_Name) = E_Package then
5857 Find_Expanded_Name (N);
5859 elsif Is_Overloadable (P_Name) then
5861 -- The subprogram may be a renaming (of an enclosing scope) as
5862 -- in the case of the name of the generic within an instantiation.
5864 if Ekind_In (P_Name, E_Procedure, E_Function)
5865 and then Present (Alias (P_Name))
5866 and then Is_Generic_Instance (Alias (P_Name))
5868 P_Name := Alias (P_Name);
5871 if Is_Overloaded (P) then
5873 -- The prefix must resolve to a unique enclosing construct
5876 Found : Boolean := False;
5881 Get_First_Interp (P, Ind, It);
5882 while Present (It.Nam) loop
5883 if In_Open_Scopes (It.Nam) then
5886 "prefix must be unique enclosing scope", N);
5887 Set_Entity (N, Any_Id);
5888 Set_Etype (N, Any_Type);
5897 Get_Next_Interp (Ind, It);
5902 if In_Open_Scopes (P_Name) then
5903 Set_Entity (P, P_Name);
5904 Set_Is_Overloaded (P, False);
5905 Find_Expanded_Name (N);
5908 -- If no interpretation as an expanded name is possible, it
5909 -- must be a selected component of a record returned by a
5910 -- function call. Reformat prefix as a function call, the rest
5911 -- is done by type resolution. If the prefix is procedure or
5912 -- entry, as is P.X; this is an error.
5914 if Ekind (P_Name) /= E_Function
5915 and then (not Is_Overloaded (P)
5917 Nkind (Parent (N)) = N_Procedure_Call_Statement)
5919 -- Prefix may mention a package that is hidden by a local
5920 -- declaration: let the user know. Scan the full homonym
5921 -- chain, the candidate package may be anywhere on it.
5923 if Present (Homonym (Current_Entity (P_Name))) then
5925 P_Name := Current_Entity (P_Name);
5927 while Present (P_Name) loop
5928 exit when Ekind (P_Name) = E_Package;
5929 P_Name := Homonym (P_Name);
5932 if Present (P_Name) then
5933 Error_Msg_Sloc := Sloc (Entity (Prefix (N)));
5936 ("package& is hidden by declaration#",
5939 Set_Entity (Prefix (N), P_Name);
5940 Find_Expanded_Name (N);
5943 P_Name := Entity (Prefix (N));
5948 ("invalid prefix in selected component&", N, P_Name);
5949 Change_Selected_Component_To_Expanded_Name (N);
5950 Set_Entity (N, Any_Id);
5951 Set_Etype (N, Any_Type);
5954 Nam := New_Copy (P);
5955 Save_Interps (P, Nam);
5957 Make_Function_Call (Sloc (P), Name => Nam));
5959 Analyze_Selected_Component (N);
5963 -- Remaining cases generate various error messages
5966 -- Format node as expanded name, to avoid cascaded errors
5968 Change_Selected_Component_To_Expanded_Name (N);
5969 Set_Entity (N, Any_Id);
5970 Set_Etype (N, Any_Type);
5972 -- Issue error message, but avoid this if error issued already.
5973 -- Use identifier of prefix if one is available.
5975 if P_Name = Any_Id then
5978 elsif Ekind (P_Name) = E_Void then
5979 Premature_Usage (P);
5981 elsif Nkind (P) /= N_Attribute_Reference then
5983 "invalid prefix in selected component&", P);
5985 if Is_Access_Type (P_Type)
5986 and then Ekind (Designated_Type (P_Type)) = E_Incomplete_Type
5989 ("\dereference must not be of an incomplete type " &
5995 "invalid prefix in selected component", P);
5999 -- Selector name is restricted in SPARK
6001 if Nkind (N) = N_Expanded_Name
6002 and then Restriction_Check_Required (SPARK)
6004 if Is_Subprogram (P_Name) then
6005 Check_SPARK_Restriction
6006 ("prefix of expanded name cannot be a subprogram", P);
6007 elsif Ekind (P_Name) = E_Loop then
6008 Check_SPARK_Restriction
6009 ("prefix of expanded name cannot be a loop statement", P);
6014 -- If prefix is not the name of an entity, it must be an expression,
6015 -- whose type is appropriate for a record. This is determined by
6018 Analyze_Selected_Component (N);
6020 end Find_Selected_Component;
6026 procedure Find_Type (N : Node_Id) is
6036 elsif Nkind (N) = N_Attribute_Reference then
6038 -- Class attribute. This is not valid in Ada 83 mode, but we do not
6039 -- need to enforce that at this point, since the declaration of the
6040 -- tagged type in the prefix would have been flagged already.
6042 if Attribute_Name (N) = Name_Class then
6043 Check_Restriction (No_Dispatch, N);
6044 Find_Type (Prefix (N));
6046 -- Propagate error from bad prefix
6048 if Etype (Prefix (N)) = Any_Type then
6049 Set_Entity (N, Any_Type);
6050 Set_Etype (N, Any_Type);
6054 T := Base_Type (Entity (Prefix (N)));
6056 -- Case where type is not known to be tagged. Its appearance in
6057 -- the prefix of the 'Class attribute indicates that the full view
6060 if not Is_Tagged_Type (T) then
6061 if Ekind (T) = E_Incomplete_Type then
6063 -- It is legal to denote the class type of an incomplete
6064 -- type. The full type will have to be tagged, of course.
6065 -- In Ada 2005 this usage is declared obsolescent, so we
6066 -- warn accordingly. This usage is only legal if the type
6067 -- is completed in the current scope, and not for a limited
6070 if not Is_Tagged_Type (T)
6071 and then Ada_Version >= Ada_2005
6073 if From_With_Type (T) then
6075 ("prefix of Class attribute must be tagged", N);
6076 Set_Etype (N, Any_Type);
6077 Set_Entity (N, Any_Type);
6080 -- ??? This test is temporarily disabled (always False)
6081 -- because it causes an unwanted warning on GNAT sources
6082 -- (built with -gnatg, which includes Warn_On_Obsolescent_
6083 -- Feature). Once this issue is cleared in the sources, it
6086 elsif Warn_On_Obsolescent_Feature
6090 ("applying 'Class to an untagged incomplete type"
6091 & " is an obsolescent feature (RM J.11)", N);
6095 Set_Is_Tagged_Type (T);
6096 Set_Direct_Primitive_Operations (T, New_Elmt_List);
6097 Make_Class_Wide_Type (T);
6098 Set_Entity (N, Class_Wide_Type (T));
6099 Set_Etype (N, Class_Wide_Type (T));
6101 elsif Ekind (T) = E_Private_Type
6102 and then not Is_Generic_Type (T)
6103 and then In_Private_Part (Scope (T))
6105 -- The Class attribute can be applied to an untagged private
6106 -- type fulfilled by a tagged type prior to the full type
6107 -- declaration (but only within the parent package's private
6108 -- part). Create the class-wide type now and check that the
6109 -- full type is tagged later during its analysis. Note that
6110 -- we do not mark the private type as tagged, unlike the
6111 -- case of incomplete types, because the type must still
6112 -- appear untagged to outside units.
6114 if No (Class_Wide_Type (T)) then
6115 Make_Class_Wide_Type (T);
6118 Set_Entity (N, Class_Wide_Type (T));
6119 Set_Etype (N, Class_Wide_Type (T));
6122 -- Should we introduce a type Any_Tagged and use Wrong_Type
6123 -- here, it would be a bit more consistent???
6126 ("tagged type required, found}",
6127 Prefix (N), First_Subtype (T));
6128 Set_Entity (N, Any_Type);
6132 -- Case of tagged type
6135 if Is_Concurrent_Type (T) then
6136 if No (Corresponding_Record_Type (Entity (Prefix (N)))) then
6138 -- Previous error. Use current type, which at least
6139 -- provides some operations.
6141 C := Entity (Prefix (N));
6144 C := Class_Wide_Type
6145 (Corresponding_Record_Type (Entity (Prefix (N))));
6149 C := Class_Wide_Type (Entity (Prefix (N)));
6152 Set_Entity_With_Style_Check (N, C);
6153 Generate_Reference (C, N);
6157 -- Base attribute, not allowed in Ada 83
6159 elsif Attribute_Name (N) = Name_Base then
6160 Error_Msg_Name_1 := Name_Base;
6161 Check_SPARK_Restriction
6162 ("attribute% is only allowed as prefix of another attribute", N);
6164 if Ada_Version = Ada_83 and then Comes_From_Source (N) then
6166 ("(Ada 83) Base attribute not allowed in subtype mark", N);
6169 Find_Type (Prefix (N));
6170 Typ := Entity (Prefix (N));
6172 if Ada_Version >= Ada_95
6173 and then not Is_Scalar_Type (Typ)
6174 and then not Is_Generic_Type (Typ)
6177 ("prefix of Base attribute must be scalar type",
6180 elsif Warn_On_Redundant_Constructs
6181 and then Base_Type (Typ) = Typ
6183 Error_Msg_NE -- CODEFIX
6184 ("?redundant attribute, & is its own base type", N, Typ);
6187 T := Base_Type (Typ);
6189 -- Rewrite attribute reference with type itself (see similar
6190 -- processing in Analyze_Attribute, case Base). Preserve prefix
6191 -- if present, for other legality checks.
6193 if Nkind (Prefix (N)) = N_Expanded_Name then
6195 Make_Expanded_Name (Sloc (N),
6197 Prefix => New_Copy (Prefix (Prefix (N))),
6198 Selector_Name => New_Reference_To (T, Sloc (N))));
6201 Rewrite (N, New_Reference_To (T, Sloc (N)));
6208 elsif Attribute_Name (N) = Name_Stub_Type then
6210 -- This is handled in Analyze_Attribute
6214 -- All other attributes are invalid in a subtype mark
6217 Error_Msg_N ("invalid attribute in subtype mark", N);
6223 if Is_Entity_Name (N) then
6224 T_Name := Entity (N);
6226 Error_Msg_N ("subtype mark required in this context", N);
6227 Set_Etype (N, Any_Type);
6231 if T_Name = Any_Id or else Etype (N) = Any_Type then
6233 -- Undefined id. Make it into a valid type
6235 Set_Entity (N, Any_Type);
6237 elsif not Is_Type (T_Name)
6238 and then T_Name /= Standard_Void_Type
6240 Error_Msg_Sloc := Sloc (T_Name);
6241 Error_Msg_N ("subtype mark required in this context", N);
6242 Error_Msg_NE ("\\found & declared#", N, T_Name);
6243 Set_Entity (N, Any_Type);
6246 -- If the type is an incomplete type created to handle
6247 -- anonymous access components of a record type, then the
6248 -- incomplete type is the visible entity and subsequent
6249 -- references will point to it. Mark the original full
6250 -- type as referenced, to prevent spurious warnings.
6252 if Is_Incomplete_Type (T_Name)
6253 and then Present (Full_View (T_Name))
6254 and then not Comes_From_Source (T_Name)
6256 Set_Referenced (Full_View (T_Name));
6259 T_Name := Get_Full_View (T_Name);
6261 -- Ada 2005 (AI-251, AI-50217): Handle interfaces visible through
6262 -- limited-with clauses
6264 if From_With_Type (T_Name)
6265 and then Ekind (T_Name) in Incomplete_Kind
6266 and then Present (Non_Limited_View (T_Name))
6267 and then Is_Interface (Non_Limited_View (T_Name))
6269 T_Name := Non_Limited_View (T_Name);
6272 if In_Open_Scopes (T_Name) then
6273 if Ekind (Base_Type (T_Name)) = E_Task_Type then
6275 -- In Ada 2005, a task name can be used in an access
6276 -- definition within its own body. It cannot be used
6277 -- in the discriminant part of the task declaration,
6278 -- nor anywhere else in the declaration because entries
6279 -- cannot have access parameters.
6281 if Ada_Version >= Ada_2005
6282 and then Nkind (Parent (N)) = N_Access_Definition
6284 Set_Entity (N, T_Name);
6285 Set_Etype (N, T_Name);
6287 if Has_Completion (T_Name) then
6292 ("task type cannot be used as type mark " &
6293 "within its own declaration", N);
6298 ("task type cannot be used as type mark " &
6299 "within its own spec or body", N);
6302 elsif Ekind (Base_Type (T_Name)) = E_Protected_Type then
6304 -- In Ada 2005, a protected name can be used in an access
6305 -- definition within its own body.
6307 if Ada_Version >= Ada_2005
6308 and then Nkind (Parent (N)) = N_Access_Definition
6310 Set_Entity (N, T_Name);
6311 Set_Etype (N, T_Name);
6316 ("protected type cannot be used as type mark " &
6317 "within its own spec or body", N);
6321 Error_Msg_N ("type declaration cannot refer to itself", N);
6324 Set_Etype (N, Any_Type);
6325 Set_Entity (N, Any_Type);
6326 Set_Error_Posted (T_Name);
6330 Set_Entity (N, T_Name);
6331 Set_Etype (N, T_Name);
6335 if Present (Etype (N)) and then Comes_From_Source (N) then
6336 if Is_Fixed_Point_Type (Etype (N)) then
6337 Check_Restriction (No_Fixed_Point, N);
6338 elsif Is_Floating_Point_Type (Etype (N)) then
6339 Check_Restriction (No_Floating_Point, N);
6344 ------------------------------------
6345 -- Has_Implicit_Character_Literal --
6346 ------------------------------------
6348 function Has_Implicit_Character_Literal (N : Node_Id) return Boolean is
6350 Found : Boolean := False;
6351 P : constant Entity_Id := Entity (Prefix (N));
6352 Priv_Id : Entity_Id := Empty;
6355 if Ekind (P) = E_Package
6356 and then not In_Open_Scopes (P)
6358 Priv_Id := First_Private_Entity (P);
6361 if P = Standard_Standard then
6362 Change_Selected_Component_To_Expanded_Name (N);
6363 Rewrite (N, Selector_Name (N));
6365 Set_Etype (Original_Node (N), Standard_Character);
6369 Id := First_Entity (P);
6371 and then Id /= Priv_Id
6373 if Is_Standard_Character_Type (Id) and then Is_Base_Type (Id) then
6375 -- We replace the node with the literal itself, resolve as a
6376 -- character, and set the type correctly.
6379 Change_Selected_Component_To_Expanded_Name (N);
6380 Rewrite (N, Selector_Name (N));
6383 Set_Etype (Original_Node (N), Id);
6387 -- More than one type derived from Character in given scope.
6388 -- Collect all possible interpretations.
6390 Add_One_Interp (N, Id, Id);
6398 end Has_Implicit_Character_Literal;
6400 ----------------------
6401 -- Has_Private_With --
6402 ----------------------
6404 function Has_Private_With (E : Entity_Id) return Boolean is
6405 Comp_Unit : constant Node_Id := Cunit (Current_Sem_Unit);
6409 Item := First (Context_Items (Comp_Unit));
6410 while Present (Item) loop
6411 if Nkind (Item) = N_With_Clause
6412 and then Private_Present (Item)
6413 and then Entity (Name (Item)) = E
6422 end Has_Private_With;
6424 ---------------------------
6425 -- Has_Implicit_Operator --
6426 ---------------------------
6428 function Has_Implicit_Operator (N : Node_Id) return Boolean is
6429 Op_Id : constant Name_Id := Chars (Selector_Name (N));
6430 P : constant Entity_Id := Entity (Prefix (N));
6432 Priv_Id : Entity_Id := Empty;
6434 procedure Add_Implicit_Operator
6436 Op_Type : Entity_Id := Empty);
6437 -- Add implicit interpretation to node N, using the type for which a
6438 -- predefined operator exists. If the operator yields a boolean type,
6439 -- the Operand_Type is implicitly referenced by the operator, and a
6440 -- reference to it must be generated.
6442 ---------------------------
6443 -- Add_Implicit_Operator --
6444 ---------------------------
6446 procedure Add_Implicit_Operator
6448 Op_Type : Entity_Id := Empty)
6450 Predef_Op : Entity_Id;
6453 Predef_Op := Current_Entity (Selector_Name (N));
6455 while Present (Predef_Op)
6456 and then Scope (Predef_Op) /= Standard_Standard
6458 Predef_Op := Homonym (Predef_Op);
6461 if Nkind (N) = N_Selected_Component then
6462 Change_Selected_Component_To_Expanded_Name (N);
6465 -- If the context is an unanalyzed function call, determine whether
6466 -- a binary or unary interpretation is required.
6468 if Nkind (Parent (N)) = N_Indexed_Component then
6470 Is_Binary_Call : constant Boolean :=
6472 (Next (First (Expressions (Parent (N)))));
6473 Is_Binary_Op : constant Boolean :=
6475 (Predef_Op) /= Last_Entity (Predef_Op);
6476 Predef_Op2 : constant Entity_Id := Homonym (Predef_Op);
6479 if Is_Binary_Call then
6480 if Is_Binary_Op then
6481 Add_One_Interp (N, Predef_Op, T);
6483 Add_One_Interp (N, Predef_Op2, T);
6487 if not Is_Binary_Op then
6488 Add_One_Interp (N, Predef_Op, T);
6490 Add_One_Interp (N, Predef_Op2, T);
6496 Add_One_Interp (N, Predef_Op, T);
6498 -- For operators with unary and binary interpretations, if
6499 -- context is not a call, add both
6501 if Present (Homonym (Predef_Op)) then
6502 Add_One_Interp (N, Homonym (Predef_Op), T);
6506 -- The node is a reference to a predefined operator, and
6507 -- an implicit reference to the type of its operands.
6509 if Present (Op_Type) then
6510 Generate_Operator_Reference (N, Op_Type);
6512 Generate_Operator_Reference (N, T);
6514 end Add_Implicit_Operator;
6516 -- Start of processing for Has_Implicit_Operator
6519 if Ekind (P) = E_Package
6520 and then not In_Open_Scopes (P)
6522 Priv_Id := First_Private_Entity (P);
6525 Id := First_Entity (P);
6529 -- Boolean operators: an implicit declaration exists if the scope
6530 -- contains a declaration for a derived Boolean type, or for an
6531 -- array of Boolean type.
6533 when Name_Op_And | Name_Op_Not | Name_Op_Or | Name_Op_Xor =>
6534 while Id /= Priv_Id loop
6535 if Valid_Boolean_Arg (Id) and then Is_Base_Type (Id) then
6536 Add_Implicit_Operator (Id);
6543 -- Equality: look for any non-limited type (result is Boolean)
6545 when Name_Op_Eq | Name_Op_Ne =>
6546 while Id /= Priv_Id loop
6548 and then not Is_Limited_Type (Id)
6549 and then Is_Base_Type (Id)
6551 Add_Implicit_Operator (Standard_Boolean, Id);
6558 -- Comparison operators: scalar type, or array of scalar
6560 when Name_Op_Lt | Name_Op_Le | Name_Op_Gt | Name_Op_Ge =>
6561 while Id /= Priv_Id loop
6562 if (Is_Scalar_Type (Id)
6563 or else (Is_Array_Type (Id)
6564 and then Is_Scalar_Type (Component_Type (Id))))
6565 and then Is_Base_Type (Id)
6567 Add_Implicit_Operator (Standard_Boolean, Id);
6574 -- Arithmetic operators: any numeric type
6584 while Id /= Priv_Id loop
6585 if Is_Numeric_Type (Id) and then Is_Base_Type (Id) then
6586 Add_Implicit_Operator (Id);
6593 -- Concatenation: any one-dimensional array type
6595 when Name_Op_Concat =>
6596 while Id /= Priv_Id loop
6597 if Is_Array_Type (Id)
6598 and then Number_Dimensions (Id) = 1
6599 and then Is_Base_Type (Id)
6601 Add_Implicit_Operator (Id);
6608 -- What is the others condition here? Should we be using a
6609 -- subtype of Name_Id that would restrict to operators ???
6611 when others => null;
6614 -- If we fall through, then we do not have an implicit operator
6618 end Has_Implicit_Operator;
6620 -----------------------------------
6621 -- Has_Loop_In_Inner_Open_Scopes --
6622 -----------------------------------
6624 function Has_Loop_In_Inner_Open_Scopes (S : Entity_Id) return Boolean is
6626 -- Several scope stacks are maintained by Scope_Stack. The base of the
6627 -- currently active scope stack is denoted by the Is_Active_Stack_Base
6628 -- flag in the scope stack entry. Note that the scope stacks used to
6629 -- simply be delimited implicitly by the presence of Standard_Standard
6630 -- at their base, but there now are cases where this is not sufficient
6631 -- because Standard_Standard actually may appear in the middle of the
6632 -- active set of scopes.
6634 for J in reverse 0 .. Scope_Stack.Last loop
6636 -- S was reached without seing a loop scope first
6638 if Scope_Stack.Table (J).Entity = S then
6641 -- S was not yet reached, so it contains at least one inner loop
6643 elsif Ekind (Scope_Stack.Table (J).Entity) = E_Loop then
6647 -- Check Is_Active_Stack_Base to tell us when to stop, as there are
6648 -- cases where Standard_Standard appears in the middle of the active
6649 -- set of scopes. This affects the declaration and overriding of
6650 -- private inherited operations in instantiations of generic child
6653 pragma Assert (not Scope_Stack.Table (J).Is_Active_Stack_Base);
6656 raise Program_Error; -- unreachable
6657 end Has_Loop_In_Inner_Open_Scopes;
6659 --------------------
6660 -- In_Open_Scopes --
6661 --------------------
6663 function In_Open_Scopes (S : Entity_Id) return Boolean is
6665 -- Several scope stacks are maintained by Scope_Stack. The base of the
6666 -- currently active scope stack is denoted by the Is_Active_Stack_Base
6667 -- flag in the scope stack entry. Note that the scope stacks used to
6668 -- simply be delimited implicitly by the presence of Standard_Standard
6669 -- at their base, but there now are cases where this is not sufficient
6670 -- because Standard_Standard actually may appear in the middle of the
6671 -- active set of scopes.
6673 for J in reverse 0 .. Scope_Stack.Last loop
6674 if Scope_Stack.Table (J).Entity = S then
6678 -- Check Is_Active_Stack_Base to tell us when to stop, as there are
6679 -- cases where Standard_Standard appears in the middle of the active
6680 -- set of scopes. This affects the declaration and overriding of
6681 -- private inherited operations in instantiations of generic child
6684 exit when Scope_Stack.Table (J).Is_Active_Stack_Base;
6690 -----------------------------
6691 -- Inherit_Renamed_Profile --
6692 -----------------------------
6694 procedure Inherit_Renamed_Profile (New_S : Entity_Id; Old_S : Entity_Id) is
6701 if Ekind (Old_S) = E_Operator then
6702 New_F := First_Formal (New_S);
6704 while Present (New_F) loop
6705 Set_Etype (New_F, Base_Type (Etype (New_F)));
6706 Next_Formal (New_F);
6709 Set_Etype (New_S, Base_Type (Etype (New_S)));
6712 New_F := First_Formal (New_S);
6713 Old_F := First_Formal (Old_S);
6715 while Present (New_F) loop
6716 New_T := Etype (New_F);
6717 Old_T := Etype (Old_F);
6719 -- If the new type is a renaming of the old one, as is the
6720 -- case for actuals in instances, retain its name, to simplify
6721 -- later disambiguation.
6723 if Nkind (Parent (New_T)) = N_Subtype_Declaration
6724 and then Is_Entity_Name (Subtype_Indication (Parent (New_T)))
6725 and then Entity (Subtype_Indication (Parent (New_T))) = Old_T
6729 Set_Etype (New_F, Old_T);
6732 Next_Formal (New_F);
6733 Next_Formal (Old_F);
6736 if Ekind_In (Old_S, E_Function, E_Enumeration_Literal) then
6737 Set_Etype (New_S, Etype (Old_S));
6740 end Inherit_Renamed_Profile;
6746 procedure Initialize is
6751 -------------------------
6752 -- Install_Use_Clauses --
6753 -------------------------
6755 procedure Install_Use_Clauses
6757 Force_Installation : Boolean := False)
6765 while Present (U) loop
6767 -- Case of USE package
6769 if Nkind (U) = N_Use_Package_Clause then
6770 P := First (Names (U));
6771 while Present (P) loop
6774 if Ekind (Id) = E_Package then
6776 Note_Redundant_Use (P);
6778 elsif Present (Renamed_Object (Id))
6779 and then In_Use (Renamed_Object (Id))
6781 Note_Redundant_Use (P);
6783 elsif Force_Installation or else Applicable_Use (P) then
6784 Use_One_Package (Id, U);
6795 P := First (Subtype_Marks (U));
6796 while Present (P) loop
6797 if not Is_Entity_Name (P)
6798 or else No (Entity (P))
6802 elsif Entity (P) /= Any_Type then
6810 Next_Use_Clause (U);
6812 end Install_Use_Clauses;
6814 -------------------------------------
6815 -- Is_Appropriate_For_Entry_Prefix --
6816 -------------------------------------
6818 function Is_Appropriate_For_Entry_Prefix (T : Entity_Id) return Boolean is
6819 P_Type : Entity_Id := T;
6822 if Is_Access_Type (P_Type) then
6823 P_Type := Designated_Type (P_Type);
6826 return Is_Task_Type (P_Type) or else Is_Protected_Type (P_Type);
6827 end Is_Appropriate_For_Entry_Prefix;
6829 -------------------------------
6830 -- Is_Appropriate_For_Record --
6831 -------------------------------
6833 function Is_Appropriate_For_Record (T : Entity_Id) return Boolean is
6835 function Has_Components (T1 : Entity_Id) return Boolean;
6836 -- Determine if given type has components (i.e. is either a record
6837 -- type or a type that has discriminants).
6839 --------------------
6840 -- Has_Components --
6841 --------------------
6843 function Has_Components (T1 : Entity_Id) return Boolean is
6845 return Is_Record_Type (T1)
6846 or else (Is_Private_Type (T1) and then Has_Discriminants (T1))
6847 or else (Is_Task_Type (T1) and then Has_Discriminants (T1))
6848 or else (Is_Incomplete_Type (T1)
6849 and then From_With_Type (T1)
6850 and then Present (Non_Limited_View (T1))
6851 and then Is_Record_Type
6852 (Get_Full_View (Non_Limited_View (T1))));
6855 -- Start of processing for Is_Appropriate_For_Record
6860 and then (Has_Components (T)
6861 or else (Is_Access_Type (T)
6862 and then Has_Components (Designated_Type (T))));
6863 end Is_Appropriate_For_Record;
6865 ------------------------
6866 -- Note_Redundant_Use --
6867 ------------------------
6869 procedure Note_Redundant_Use (Clause : Node_Id) is
6870 Pack_Name : constant Entity_Id := Entity (Clause);
6871 Cur_Use : constant Node_Id := Current_Use_Clause (Pack_Name);
6872 Decl : constant Node_Id := Parent (Clause);
6874 Prev_Use : Node_Id := Empty;
6875 Redundant : Node_Id := Empty;
6876 -- The Use_Clause which is actually redundant. In the simplest case it
6877 -- is Pack itself, but when we compile a body we install its context
6878 -- before that of its spec, in which case it is the use_clause in the
6879 -- spec that will appear to be redundant, and we want the warning to be
6880 -- placed on the body. Similar complications appear when the redundancy
6881 -- is between a child unit and one of its ancestors.
6884 Set_Redundant_Use (Clause, True);
6886 if not Comes_From_Source (Clause)
6888 or else not Warn_On_Redundant_Constructs
6893 if not Is_Compilation_Unit (Current_Scope) then
6895 -- If the use_clause is in an inner scope, it is made redundant by
6896 -- some clause in the current context, with one exception: If we're
6897 -- compiling a nested package body, and the use_clause comes from the
6898 -- corresponding spec, the clause is not necessarily fully redundant,
6899 -- so we should not warn. If a warning was warranted, it would have
6900 -- been given when the spec was processed.
6902 if Nkind (Parent (Decl)) = N_Package_Specification then
6904 Package_Spec_Entity : constant Entity_Id :=
6905 Defining_Unit_Name (Parent (Decl));
6907 if In_Package_Body (Package_Spec_Entity) then
6913 Redundant := Clause;
6914 Prev_Use := Cur_Use;
6916 elsif Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Body then
6918 Cur_Unit : constant Unit_Number_Type := Get_Source_Unit (Cur_Use);
6919 New_Unit : constant Unit_Number_Type := Get_Source_Unit (Clause);
6923 if Cur_Unit = New_Unit then
6925 -- Redundant clause in same body
6927 Redundant := Clause;
6928 Prev_Use := Cur_Use;
6930 elsif Cur_Unit = Current_Sem_Unit then
6932 -- If the new clause is not in the current unit it has been
6933 -- analyzed first, and it makes the other one redundant.
6934 -- However, if the new clause appears in a subunit, Cur_Unit
6935 -- is still the parent, and in that case the redundant one
6936 -- is the one appearing in the subunit.
6938 if Nkind (Unit (Cunit (New_Unit))) = N_Subunit then
6939 Redundant := Clause;
6940 Prev_Use := Cur_Use;
6942 -- Most common case: redundant clause in body,
6943 -- original clause in spec. Current scope is spec entity.
6948 Unit (Library_Unit (Cunit (Current_Sem_Unit))))
6950 Redundant := Cur_Use;
6954 -- The new clause may appear in an unrelated unit, when
6955 -- the parents of a generic are being installed prior to
6956 -- instantiation. In this case there must be no warning.
6957 -- We detect this case by checking whether the current top
6958 -- of the stack is related to the current compilation.
6960 Scop := Current_Scope;
6961 while Present (Scop)
6962 and then Scop /= Standard_Standard
6964 if Is_Compilation_Unit (Scop)
6965 and then not Is_Child_Unit (Scop)
6969 elsif Scop = Cunit_Entity (Current_Sem_Unit) then
6973 Scop := Scope (Scop);
6976 Redundant := Cur_Use;
6980 elsif New_Unit = Current_Sem_Unit then
6981 Redundant := Clause;
6982 Prev_Use := Cur_Use;
6985 -- Neither is the current unit, so they appear in parent or
6986 -- sibling units. Warning will be emitted elsewhere.
6992 elsif Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Declaration
6993 and then Present (Parent_Spec (Unit (Cunit (Current_Sem_Unit))))
6995 -- Use_clause is in child unit of current unit, and the child unit
6996 -- appears in the context of the body of the parent, so it has been
6997 -- installed first, even though it is the redundant one. Depending on
6998 -- their placement in the context, the visible or the private parts
6999 -- of the two units, either might appear as redundant, but the
7000 -- message has to be on the current unit.
7002 if Get_Source_Unit (Cur_Use) = Current_Sem_Unit then
7003 Redundant := Cur_Use;
7006 Redundant := Clause;
7007 Prev_Use := Cur_Use;
7010 -- If the new use clause appears in the private part of a parent unit
7011 -- it may appear to be redundant w.r.t. a use clause in a child unit,
7012 -- but the previous use clause was needed in the visible part of the
7013 -- child, and no warning should be emitted.
7015 if Nkind (Parent (Decl)) = N_Package_Specification
7017 List_Containing (Decl) = Private_Declarations (Parent (Decl))
7020 Par : constant Entity_Id := Defining_Entity (Parent (Decl));
7021 Spec : constant Node_Id :=
7022 Specification (Unit (Cunit (Current_Sem_Unit)));
7025 if Is_Compilation_Unit (Par)
7026 and then Par /= Cunit_Entity (Current_Sem_Unit)
7027 and then Parent (Cur_Use) = Spec
7029 List_Containing (Cur_Use) = Visible_Declarations (Spec)
7036 -- Finally, if the current use clause is in the context then
7037 -- the clause is redundant when it is nested within the unit.
7039 elsif Nkind (Parent (Cur_Use)) = N_Compilation_Unit
7040 and then Nkind (Parent (Parent (Clause))) /= N_Compilation_Unit
7041 and then Get_Source_Unit (Cur_Use) = Get_Source_Unit (Clause)
7043 Redundant := Clause;
7044 Prev_Use := Cur_Use;
7050 if Present (Redundant) then
7051 Error_Msg_Sloc := Sloc (Prev_Use);
7052 Error_Msg_NE -- CODEFIX
7053 ("& is already use-visible through previous use clause #?",
7054 Redundant, Pack_Name);
7056 end Note_Redundant_Use;
7062 procedure Pop_Scope is
7063 SST : Scope_Stack_Entry renames Scope_Stack.Table (Scope_Stack.Last);
7064 S : constant Entity_Id := SST.Entity;
7067 if Debug_Flag_E then
7071 -- Set Default_Storage_Pool field of the library unit if necessary
7073 if Ekind_In (S, E_Package, E_Generic_Package)
7075 Nkind (Parent (Unit_Declaration_Node (S))) = N_Compilation_Unit
7078 Aux : constant Node_Id :=
7079 Aux_Decls_Node (Parent (Unit_Declaration_Node (S)));
7081 if No (Default_Storage_Pool (Aux)) then
7082 Set_Default_Storage_Pool (Aux, Default_Pool);
7087 Scope_Suppress := SST.Save_Scope_Suppress;
7088 Local_Suppress_Stack_Top := SST.Save_Local_Suppress_Stack_Top;
7089 Check_Policy_List := SST.Save_Check_Policy_List;
7090 Default_Pool := SST.Save_Default_Storage_Pool;
7092 if Debug_Flag_W then
7093 Write_Str ("<-- exiting scope: ");
7094 Write_Name (Chars (Current_Scope));
7095 Write_Str (", Depth=");
7096 Write_Int (Int (Scope_Stack.Last));
7100 End_Use_Clauses (SST.First_Use_Clause);
7102 -- If the actions to be wrapped are still there they will get lost
7103 -- causing incomplete code to be generated. It is better to abort in
7104 -- this case (and we do the abort even with assertions off since the
7105 -- penalty is incorrect code generation)
7107 if SST.Actions_To_Be_Wrapped_Before /= No_List
7109 SST.Actions_To_Be_Wrapped_After /= No_List
7111 raise Program_Error;
7114 -- Free last subprogram name if allocated, and pop scope
7116 Free (SST.Last_Subprogram_Name);
7117 Scope_Stack.Decrement_Last;
7124 procedure Push_Scope (S : Entity_Id) is
7125 E : constant Entity_Id := Scope (S);
7128 if Ekind (S) = E_Void then
7131 -- Set scope depth if not a non-concurrent type, and we have not yet set
7132 -- the scope depth. This means that we have the first occurrence of the
7133 -- scope, and this is where the depth is set.
7135 elsif (not Is_Type (S) or else Is_Concurrent_Type (S))
7136 and then not Scope_Depth_Set (S)
7138 if S = Standard_Standard then
7139 Set_Scope_Depth_Value (S, Uint_0);
7141 elsif Is_Child_Unit (S) then
7142 Set_Scope_Depth_Value (S, Uint_1);
7144 elsif not Is_Record_Type (Current_Scope) then
7145 if Ekind (S) = E_Loop then
7146 Set_Scope_Depth_Value (S, Scope_Depth (Current_Scope));
7148 Set_Scope_Depth_Value (S, Scope_Depth (Current_Scope) + 1);
7153 Scope_Stack.Increment_Last;
7156 SST : Scope_Stack_Entry renames Scope_Stack.Table (Scope_Stack.Last);
7160 SST.Save_Scope_Suppress := Scope_Suppress;
7161 SST.Save_Local_Suppress_Stack_Top := Local_Suppress_Stack_Top;
7162 SST.Save_Check_Policy_List := Check_Policy_List;
7163 SST.Save_Default_Storage_Pool := Default_Pool;
7165 if Scope_Stack.Last > Scope_Stack.First then
7166 SST.Component_Alignment_Default := Scope_Stack.Table
7167 (Scope_Stack.Last - 1).
7168 Component_Alignment_Default;
7171 SST.Last_Subprogram_Name := null;
7172 SST.Is_Transient := False;
7173 SST.Node_To_Be_Wrapped := Empty;
7174 SST.Pending_Freeze_Actions := No_List;
7175 SST.Actions_To_Be_Wrapped_Before := No_List;
7176 SST.Actions_To_Be_Wrapped_After := No_List;
7177 SST.First_Use_Clause := Empty;
7178 SST.Is_Active_Stack_Base := False;
7179 SST.Previous_Visibility := False;
7182 if Debug_Flag_W then
7183 Write_Str ("--> new scope: ");
7184 Write_Name (Chars (Current_Scope));
7185 Write_Str (", Id=");
7186 Write_Int (Int (Current_Scope));
7187 Write_Str (", Depth=");
7188 Write_Int (Int (Scope_Stack.Last));
7192 -- Deal with copying flags from the previous scope to this one. This is
7193 -- not necessary if either scope is standard, or if the new scope is a
7196 if S /= Standard_Standard
7197 and then Scope (S) /= Standard_Standard
7198 and then not Is_Child_Unit (S)
7200 if Nkind (E) not in N_Entity then
7204 -- Copy categorization flags from Scope (S) to S, this is not done
7205 -- when Scope (S) is Standard_Standard since propagation is from
7206 -- library unit entity inwards. Copy other relevant attributes as
7207 -- well (Discard_Names in particular).
7209 -- We only propagate inwards for library level entities,
7210 -- inner level subprograms do not inherit the categorization.
7212 if Is_Library_Level_Entity (S) then
7213 Set_Is_Preelaborated (S, Is_Preelaborated (E));
7214 Set_Is_Shared_Passive (S, Is_Shared_Passive (E));
7215 Set_Discard_Names (S, Discard_Names (E));
7216 Set_Suppress_Value_Tracking_On_Call
7217 (S, Suppress_Value_Tracking_On_Call (E));
7218 Set_Categorization_From_Scope (E => S, Scop => E);
7222 if Is_Child_Unit (S)
7223 and then Present (E)
7224 and then Ekind_In (E, E_Package, E_Generic_Package)
7226 Nkind (Parent (Unit_Declaration_Node (E))) = N_Compilation_Unit
7229 Aux : constant Node_Id :=
7230 Aux_Decls_Node (Parent (Unit_Declaration_Node (E)));
7232 if Present (Default_Storage_Pool (Aux)) then
7233 Default_Pool := Default_Storage_Pool (Aux);
7239 ---------------------
7240 -- Premature_Usage --
7241 ---------------------
7243 procedure Premature_Usage (N : Node_Id) is
7244 Kind : constant Node_Kind := Nkind (Parent (Entity (N)));
7245 E : Entity_Id := Entity (N);
7248 -- Within an instance, the analysis of the actual for a formal object
7249 -- does not see the name of the object itself. This is significant only
7250 -- if the object is an aggregate, where its analysis does not do any
7251 -- name resolution on component associations. (see 4717-008). In such a
7252 -- case, look for the visible homonym on the chain.
7255 and then Present (Homonym (E))
7260 and then not In_Open_Scopes (Scope (E))
7267 Set_Etype (N, Etype (E));
7272 if Kind = N_Component_Declaration then
7274 ("component&! cannot be used before end of record declaration", N);
7276 elsif Kind = N_Parameter_Specification then
7278 ("formal parameter&! cannot be used before end of specification",
7281 elsif Kind = N_Discriminant_Specification then
7283 ("discriminant&! cannot be used before end of discriminant part",
7286 elsif Kind = N_Procedure_Specification
7287 or else Kind = N_Function_Specification
7290 ("subprogram&! cannot be used before end of its declaration",
7293 elsif Kind = N_Full_Type_Declaration then
7295 ("type& cannot be used before end of its declaration!", N);
7299 ("object& cannot be used before end of its declaration!", N);
7301 end Premature_Usage;
7303 ------------------------
7304 -- Present_System_Aux --
7305 ------------------------
7307 function Present_System_Aux (N : Node_Id := Empty) return Boolean is
7309 Aux_Name : Unit_Name_Type;
7310 Unum : Unit_Number_Type;
7315 function Find_System (C_Unit : Node_Id) return Entity_Id;
7316 -- Scan context clause of compilation unit to find with_clause
7323 function Find_System (C_Unit : Node_Id) return Entity_Id is
7324 With_Clause : Node_Id;
7327 With_Clause := First (Context_Items (C_Unit));
7328 while Present (With_Clause) loop
7329 if (Nkind (With_Clause) = N_With_Clause
7330 and then Chars (Name (With_Clause)) = Name_System)
7331 and then Comes_From_Source (With_Clause)
7342 -- Start of processing for Present_System_Aux
7345 -- The child unit may have been loaded and analyzed already
7347 if Present (System_Aux_Id) then
7350 -- If no previous pragma for System.Aux, nothing to load
7352 elsif No (System_Extend_Unit) then
7355 -- Use the unit name given in the pragma to retrieve the unit.
7356 -- Verify that System itself appears in the context clause of the
7357 -- current compilation. If System is not present, an error will
7358 -- have been reported already.
7361 With_Sys := Find_System (Cunit (Current_Sem_Unit));
7363 The_Unit := Unit (Cunit (Current_Sem_Unit));
7367 (Nkind (The_Unit) = N_Package_Body
7368 or else (Nkind (The_Unit) = N_Subprogram_Body
7370 not Acts_As_Spec (Cunit (Current_Sem_Unit))))
7372 With_Sys := Find_System (Library_Unit (Cunit (Current_Sem_Unit)));
7376 and then Present (N)
7378 -- If we are compiling a subunit, we need to examine its
7379 -- context as well (Current_Sem_Unit is the parent unit);
7381 The_Unit := Parent (N);
7382 while Nkind (The_Unit) /= N_Compilation_Unit loop
7383 The_Unit := Parent (The_Unit);
7386 if Nkind (Unit (The_Unit)) = N_Subunit then
7387 With_Sys := Find_System (The_Unit);
7391 if No (With_Sys) then
7395 Loc := Sloc (With_Sys);
7396 Get_Name_String (Chars (Expression (System_Extend_Unit)));
7397 Name_Buffer (8 .. Name_Len + 7) := Name_Buffer (1 .. Name_Len);
7398 Name_Buffer (1 .. 7) := "system.";
7399 Name_Buffer (Name_Len + 8) := '%';
7400 Name_Buffer (Name_Len + 9) := 's';
7401 Name_Len := Name_Len + 9;
7402 Aux_Name := Name_Find;
7406 (Load_Name => Aux_Name,
7409 Error_Node => With_Sys);
7411 if Unum /= No_Unit then
7412 Semantics (Cunit (Unum));
7414 Defining_Entity (Specification (Unit (Cunit (Unum))));
7417 Make_With_Clause (Loc,
7419 Make_Expanded_Name (Loc,
7420 Chars => Chars (System_Aux_Id),
7421 Prefix => New_Reference_To (Scope (System_Aux_Id), Loc),
7422 Selector_Name => New_Reference_To (System_Aux_Id, Loc)));
7424 Set_Entity (Name (Withn), System_Aux_Id);
7426 Set_Library_Unit (Withn, Cunit (Unum));
7427 Set_Corresponding_Spec (Withn, System_Aux_Id);
7428 Set_First_Name (Withn, True);
7429 Set_Implicit_With (Withn, True);
7431 Insert_After (With_Sys, Withn);
7432 Mark_Rewrite_Insertion (Withn);
7433 Set_Context_Installed (Withn);
7437 -- Here if unit load failed
7440 Error_Msg_Name_1 := Name_System;
7441 Error_Msg_Name_2 := Chars (Expression (System_Extend_Unit));
7443 ("extension package `%.%` does not exist",
7444 Opt.System_Extend_Unit);
7448 end Present_System_Aux;
7450 -------------------------
7451 -- Restore_Scope_Stack --
7452 -------------------------
7454 procedure Restore_Scope_Stack (Handle_Use : Boolean := True) is
7457 Comp_Unit : Node_Id;
7458 In_Child : Boolean := False;
7459 Full_Vis : Boolean := True;
7460 SS_Last : constant Int := Scope_Stack.Last;
7463 -- Restore visibility of previous scope stack, if any
7465 for J in reverse 0 .. Scope_Stack.Last loop
7466 exit when Scope_Stack.Table (J).Entity = Standard_Standard
7467 or else No (Scope_Stack.Table (J).Entity);
7469 S := Scope_Stack.Table (J).Entity;
7471 if not Is_Hidden_Open_Scope (S) then
7473 -- If the parent scope is hidden, its entities are hidden as
7474 -- well, unless the entity is the instantiation currently
7477 if not Is_Hidden_Open_Scope (Scope (S))
7478 or else not Analyzed (Parent (S))
7479 or else Scope (S) = Standard_Standard
7481 Set_Is_Immediately_Visible (S, True);
7484 E := First_Entity (S);
7485 while Present (E) loop
7486 if Is_Child_Unit (E) then
7487 if not From_With_Type (E) then
7488 Set_Is_Immediately_Visible (E,
7489 Is_Visible_Child_Unit (E) or else In_Open_Scopes (E));
7493 (Nkind (Parent (E)) = N_Defining_Program_Unit_Name
7495 Nkind (Parent (Parent (E))) = N_Package_Specification);
7496 Set_Is_Immediately_Visible (E,
7497 Limited_View_Installed (Parent (Parent (E))));
7500 Set_Is_Immediately_Visible (E, True);
7506 and then Is_Package_Or_Generic_Package (S)
7508 -- We are in the visible part of the package scope
7510 exit when E = First_Private_Entity (S);
7514 -- The visibility of child units (siblings of current compilation)
7515 -- must be restored in any case. Their declarations may appear
7516 -- after the private part of the parent.
7518 if not Full_Vis then
7519 while Present (E) loop
7520 if Is_Child_Unit (E) then
7521 Set_Is_Immediately_Visible (E,
7522 Is_Visible_Child_Unit (E) or else In_Open_Scopes (E));
7530 if Is_Child_Unit (S)
7531 and not In_Child -- check only for current unit
7535 -- Restore visibility of parents according to whether the child
7536 -- is private and whether we are in its visible part.
7538 Comp_Unit := Parent (Unit_Declaration_Node (S));
7540 if Nkind (Comp_Unit) = N_Compilation_Unit
7541 and then Private_Present (Comp_Unit)
7545 elsif Is_Package_Or_Generic_Package (S)
7546 and then (In_Private_Part (S) or else In_Package_Body (S))
7550 -- if S is the scope of some instance (which has already been
7551 -- seen on the stack) it does not affect the visibility of
7554 elsif Is_Hidden_Open_Scope (S) then
7557 elsif (Ekind (S) = E_Procedure
7558 or else Ekind (S) = E_Function)
7559 and then Has_Completion (S)
7570 if SS_Last >= Scope_Stack.First
7571 and then Scope_Stack.Table (SS_Last).Entity /= Standard_Standard
7574 Install_Use_Clauses (Scope_Stack.Table (SS_Last).First_Use_Clause);
7576 end Restore_Scope_Stack;
7578 ----------------------
7579 -- Save_Scope_Stack --
7580 ----------------------
7582 procedure Save_Scope_Stack (Handle_Use : Boolean := True) is
7585 SS_Last : constant Int := Scope_Stack.Last;
7588 if SS_Last >= Scope_Stack.First
7589 and then Scope_Stack.Table (SS_Last).Entity /= Standard_Standard
7592 End_Use_Clauses (Scope_Stack.Table (SS_Last).First_Use_Clause);
7595 -- If the call is from within a compilation unit, as when called from
7596 -- Rtsfind, make current entries in scope stack invisible while we
7597 -- analyze the new unit.
7599 for J in reverse 0 .. SS_Last loop
7600 exit when Scope_Stack.Table (J).Entity = Standard_Standard
7601 or else No (Scope_Stack.Table (J).Entity);
7603 S := Scope_Stack.Table (J).Entity;
7604 Set_Is_Immediately_Visible (S, False);
7606 E := First_Entity (S);
7607 while Present (E) loop
7608 Set_Is_Immediately_Visible (E, False);
7614 end Save_Scope_Stack;
7620 procedure Set_Use (L : List_Id) is
7622 Pack_Name : Node_Id;
7629 while Present (Decl) loop
7630 if Nkind (Decl) = N_Use_Package_Clause then
7631 Chain_Use_Clause (Decl);
7633 Pack_Name := First (Names (Decl));
7634 while Present (Pack_Name) loop
7635 Pack := Entity (Pack_Name);
7637 if Ekind (Pack) = E_Package
7638 and then Applicable_Use (Pack_Name)
7640 Use_One_Package (Pack, Decl);
7646 elsif Nkind (Decl) = N_Use_Type_Clause then
7647 Chain_Use_Clause (Decl);
7649 Id := First (Subtype_Marks (Decl));
7650 while Present (Id) loop
7651 if Entity (Id) /= Any_Type then
7664 ---------------------
7665 -- Use_One_Package --
7666 ---------------------
7668 procedure Use_One_Package (P : Entity_Id; N : Node_Id) is
7671 Current_Instance : Entity_Id := Empty;
7673 Private_With_OK : Boolean := False;
7676 if Ekind (P) /= E_Package then
7681 Set_Current_Use_Clause (P, N);
7683 -- Ada 2005 (AI-50217): Check restriction
7685 if From_With_Type (P) then
7686 Error_Msg_N ("limited withed package cannot appear in use clause", N);
7689 -- Find enclosing instance, if any
7692 Current_Instance := Current_Scope;
7693 while not Is_Generic_Instance (Current_Instance) loop
7694 Current_Instance := Scope (Current_Instance);
7697 if No (Hidden_By_Use_Clause (N)) then
7698 Set_Hidden_By_Use_Clause (N, New_Elmt_List);
7702 -- If unit is a package renaming, indicate that the renamed
7703 -- package is also in use (the flags on both entities must
7704 -- remain consistent, and a subsequent use of either of them
7705 -- should be recognized as redundant).
7707 if Present (Renamed_Object (P)) then
7708 Set_In_Use (Renamed_Object (P));
7709 Set_Current_Use_Clause (Renamed_Object (P), N);
7710 Real_P := Renamed_Object (P);
7715 -- Ada 2005 (AI-262): Check the use_clause of a private withed package
7716 -- found in the private part of a package specification
7718 if In_Private_Part (Current_Scope)
7719 and then Has_Private_With (P)
7720 and then Is_Child_Unit (Current_Scope)
7721 and then Is_Child_Unit (P)
7722 and then Is_Ancestor_Package (Scope (Current_Scope), P)
7724 Private_With_OK := True;
7727 -- Loop through entities in one package making them potentially
7730 Id := First_Entity (P);
7732 and then (Id /= First_Private_Entity (P)
7733 or else Private_With_OK) -- Ada 2005 (AI-262)
7735 Prev := Current_Entity (Id);
7736 while Present (Prev) loop
7737 if Is_Immediately_Visible (Prev)
7738 and then (not Is_Overloadable (Prev)
7739 or else not Is_Overloadable (Id)
7740 or else (Type_Conformant (Id, Prev)))
7742 if No (Current_Instance) then
7744 -- Potentially use-visible entity remains hidden
7746 goto Next_Usable_Entity;
7748 -- A use clause within an instance hides outer global entities,
7749 -- which are not used to resolve local entities in the
7750 -- instance. Note that the predefined entities in Standard
7751 -- could not have been hidden in the generic by a use clause,
7752 -- and therefore remain visible. Other compilation units whose
7753 -- entities appear in Standard must be hidden in an instance.
7755 -- To determine whether an entity is external to the instance
7756 -- we compare the scope depth of its scope with that of the
7757 -- current instance. However, a generic actual of a subprogram
7758 -- instance is declared in the wrapper package but will not be
7759 -- hidden by a use-visible entity. similarly, an entity that is
7760 -- declared in an enclosing instance will not be hidden by an
7761 -- an entity declared in a generic actual, which can only have
7762 -- been use-visible in the generic and will not have hidden the
7763 -- entity in the generic parent.
7765 -- If Id is called Standard, the predefined package with the
7766 -- same name is in the homonym chain. It has to be ignored
7767 -- because it has no defined scope (being the only entity in
7768 -- the system with this mandated behavior).
7770 elsif not Is_Hidden (Id)
7771 and then Present (Scope (Prev))
7772 and then not Is_Wrapper_Package (Scope (Prev))
7773 and then Scope_Depth (Scope (Prev)) <
7774 Scope_Depth (Current_Instance)
7775 and then (Scope (Prev) /= Standard_Standard
7776 or else Sloc (Prev) > Standard_Location)
7778 if In_Open_Scopes (Scope (Prev))
7779 and then Is_Generic_Instance (Scope (Prev))
7780 and then Present (Associated_Formal_Package (P))
7785 Set_Is_Potentially_Use_Visible (Id);
7786 Set_Is_Immediately_Visible (Prev, False);
7787 Append_Elmt (Prev, Hidden_By_Use_Clause (N));
7791 -- A user-defined operator is not use-visible if the predefined
7792 -- operator for the type is immediately visible, which is the case
7793 -- if the type of the operand is in an open scope. This does not
7794 -- apply to user-defined operators that have operands of different
7795 -- types, because the predefined mixed mode operations (multiply
7796 -- and divide) apply to universal types and do not hide anything.
7798 elsif Ekind (Prev) = E_Operator
7799 and then Operator_Matches_Spec (Prev, Id)
7800 and then In_Open_Scopes
7801 (Scope (Base_Type (Etype (First_Formal (Id)))))
7802 and then (No (Next_Formal (First_Formal (Id)))
7803 or else Etype (First_Formal (Id))
7804 = Etype (Next_Formal (First_Formal (Id)))
7805 or else Chars (Prev) = Name_Op_Expon)
7807 goto Next_Usable_Entity;
7809 -- In an instance, two homonyms may become use_visible through the
7810 -- actuals of distinct formal packages. In the generic, only the
7811 -- current one would have been visible, so make the other one
7814 elsif Present (Current_Instance)
7815 and then Is_Potentially_Use_Visible (Prev)
7816 and then not Is_Overloadable (Prev)
7817 and then Scope (Id) /= Scope (Prev)
7818 and then Used_As_Generic_Actual (Scope (Prev))
7819 and then Used_As_Generic_Actual (Scope (Id))
7820 and then not In_Same_List (Current_Use_Clause (Scope (Prev)),
7821 Current_Use_Clause (Scope (Id)))
7823 Set_Is_Potentially_Use_Visible (Prev, False);
7824 Append_Elmt (Prev, Hidden_By_Use_Clause (N));
7827 Prev := Homonym (Prev);
7830 -- On exit, we know entity is not hidden, unless it is private
7832 if not Is_Hidden (Id)
7833 and then ((not Is_Child_Unit (Id))
7834 or else Is_Visible_Child_Unit (Id))
7836 Set_Is_Potentially_Use_Visible (Id);
7838 if Is_Private_Type (Id)
7839 and then Present (Full_View (Id))
7841 Set_Is_Potentially_Use_Visible (Full_View (Id));
7845 <<Next_Usable_Entity>>
7849 -- Child units are also made use-visible by a use clause, but they may
7850 -- appear after all visible declarations in the parent entity list.
7852 while Present (Id) loop
7853 if Is_Child_Unit (Id)
7854 and then Is_Visible_Child_Unit (Id)
7856 Set_Is_Potentially_Use_Visible (Id);
7862 if Chars (Real_P) = Name_System
7863 and then Scope (Real_P) = Standard_Standard
7864 and then Present_System_Aux (N)
7866 Use_One_Package (System_Aux_Id, N);
7869 end Use_One_Package;
7875 procedure Use_One_Type (Id : Node_Id; Installed : Boolean := False) is
7877 Is_Known_Used : Boolean;
7881 function Spec_Reloaded_For_Body return Boolean;
7882 -- Determine whether the compilation unit is a package body and the use
7883 -- type clause is in the spec of the same package. Even though the spec
7884 -- was analyzed first, its context is reloaded when analysing the body.
7886 procedure Use_Class_Wide_Operations (Typ : Entity_Id);
7887 -- AI05-150: if the use_type_clause carries the "all" qualifier,
7888 -- class-wide operations of ancestor types are use-visible if the
7889 -- ancestor type is visible.
7891 ----------------------------
7892 -- Spec_Reloaded_For_Body --
7893 ----------------------------
7895 function Spec_Reloaded_For_Body return Boolean is
7897 if Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Body then
7899 Spec : constant Node_Id :=
7900 Parent (List_Containing (Parent (Id)));
7903 Nkind (Spec) = N_Package_Specification
7904 and then Corresponding_Body (Parent (Spec)) =
7905 Cunit_Entity (Current_Sem_Unit);
7910 end Spec_Reloaded_For_Body;
7912 -------------------------------
7913 -- Use_Class_Wide_Operations --
7914 -------------------------------
7916 procedure Use_Class_Wide_Operations (Typ : Entity_Id) is
7920 function Is_Class_Wide_Operation_Of
7922 T : Entity_Id) return Boolean;
7923 -- Determine whether a subprogram has a class-wide parameter or
7924 -- result that is T'Class.
7926 ---------------------------------
7927 -- Is_Class_Wide_Operation_Of --
7928 ---------------------------------
7930 function Is_Class_Wide_Operation_Of
7932 T : Entity_Id) return Boolean
7937 Formal := First_Formal (Op);
7938 while Present (Formal) loop
7939 if Etype (Formal) = Class_Wide_Type (T) then
7942 Next_Formal (Formal);
7945 if Etype (Op) = Class_Wide_Type (T) then
7950 end Is_Class_Wide_Operation_Of;
7952 -- Start of processing for Use_Class_Wide_Operations
7955 Scop := Scope (Typ);
7956 if not Is_Hidden (Scop) then
7957 Ent := First_Entity (Scop);
7958 while Present (Ent) loop
7959 if Is_Overloadable (Ent)
7960 and then Is_Class_Wide_Operation_Of (Ent, Typ)
7961 and then not Is_Potentially_Use_Visible (Ent)
7963 Set_Is_Potentially_Use_Visible (Ent);
7964 Append_Elmt (Ent, Used_Operations (Parent (Id)));
7971 if Is_Derived_Type (Typ) then
7972 Use_Class_Wide_Operations (Etype (Base_Type (Typ)));
7974 end Use_Class_Wide_Operations;
7976 -- Start of processing for Use_One_Type;
7979 -- It is the type determined by the subtype mark (8.4(8)) whose
7980 -- operations become potentially use-visible.
7982 T := Base_Type (Entity (Id));
7984 -- Either the type itself is used, the package where it is declared
7985 -- is in use or the entity is declared in the current package, thus
7990 or else In_Use (Scope (T))
7991 or else Scope (T) = Current_Scope;
7993 Set_Redundant_Use (Id,
7994 Is_Known_Used or else Is_Potentially_Use_Visible (T));
7996 if Ekind (T) = E_Incomplete_Type then
7997 Error_Msg_N ("premature usage of incomplete type", Id);
7999 elsif In_Open_Scopes (Scope (T)) then
8002 -- A limited view cannot appear in a use_type clause. However, an access
8003 -- type whose designated type is limited has the flag but is not itself
8004 -- a limited view unless we only have a limited view of its enclosing
8007 elsif From_With_Type (T)
8008 and then From_With_Type (Scope (T))
8011 ("incomplete type from limited view "
8012 & "cannot appear in use clause", Id);
8014 -- If the subtype mark designates a subtype in a different package,
8015 -- we have to check that the parent type is visible, otherwise the
8016 -- use type clause is a noop. Not clear how to do that???
8018 elsif not Redundant_Use (Id) then
8021 -- If T is tagged, primitive operators on class-wide operands
8022 -- are also available.
8024 if Is_Tagged_Type (T) then
8025 Set_In_Use (Class_Wide_Type (T));
8028 Set_Current_Use_Clause (T, Parent (Id));
8030 -- Iterate over primitive operations of the type. If an operation is
8031 -- already use_visible, it is the result of a previous use_clause,
8032 -- and already appears on the corresponding entity chain. If the
8033 -- clause is being reinstalled, operations are already use-visible.
8039 Op_List := Collect_Primitive_Operations (T);
8040 Elmt := First_Elmt (Op_List);
8041 while Present (Elmt) loop
8042 if (Nkind (Node (Elmt)) = N_Defining_Operator_Symbol
8043 or else Chars (Node (Elmt)) in Any_Operator_Name)
8044 and then not Is_Hidden (Node (Elmt))
8045 and then not Is_Potentially_Use_Visible (Node (Elmt))
8047 Set_Is_Potentially_Use_Visible (Node (Elmt));
8048 Append_Elmt (Node (Elmt), Used_Operations (Parent (Id)));
8050 elsif Ada_Version >= Ada_2012
8051 and then All_Present (Parent (Id))
8052 and then not Is_Hidden (Node (Elmt))
8053 and then not Is_Potentially_Use_Visible (Node (Elmt))
8055 Set_Is_Potentially_Use_Visible (Node (Elmt));
8056 Append_Elmt (Node (Elmt), Used_Operations (Parent (Id)));
8063 if Ada_Version >= Ada_2012
8064 and then All_Present (Parent (Id))
8065 and then Is_Tagged_Type (T)
8067 Use_Class_Wide_Operations (T);
8071 -- If warning on redundant constructs, check for unnecessary WITH
8073 if Warn_On_Redundant_Constructs
8074 and then Is_Known_Used
8076 -- with P; with P; use P;
8077 -- package P is package X is package body X is
8078 -- type T ... use P.T;
8080 -- The compilation unit is the body of X. GNAT first compiles the
8081 -- spec of X, then proceeds to the body. At that point P is marked
8082 -- as use visible. The analysis then reinstalls the spec along with
8083 -- its context. The use clause P.T is now recognized as redundant,
8084 -- but in the wrong context. Do not emit a warning in such cases.
8085 -- Do not emit a warning either if we are in an instance, there is
8086 -- no redundancy between an outer use_clause and one that appears
8087 -- within the generic.
8089 and then not Spec_Reloaded_For_Body
8090 and then not In_Instance
8092 -- The type already has a use clause
8096 -- Case where we know the current use clause for the type
8098 if Present (Current_Use_Clause (T)) then
8099 Use_Clause_Known : declare
8100 Clause1 : constant Node_Id := Parent (Id);
8101 Clause2 : constant Node_Id := Current_Use_Clause (T);
8108 function Entity_Of_Unit (U : Node_Id) return Entity_Id;
8109 -- Return the appropriate entity for determining which unit
8110 -- has a deeper scope: the defining entity for U, unless U
8111 -- is a package instance, in which case we retrieve the
8112 -- entity of the instance spec.
8114 --------------------
8115 -- Entity_Of_Unit --
8116 --------------------
8118 function Entity_Of_Unit (U : Node_Id) return Entity_Id is
8120 if Nkind (U) = N_Package_Instantiation
8121 and then Analyzed (U)
8123 return Defining_Entity (Instance_Spec (U));
8125 return Defining_Entity (U);
8129 -- Start of processing for Use_Clause_Known
8132 -- If both current use type clause and the use type clause
8133 -- for the type are at the compilation unit level, one of
8134 -- the units must be an ancestor of the other, and the
8135 -- warning belongs on the descendant.
8137 if Nkind (Parent (Clause1)) = N_Compilation_Unit
8139 Nkind (Parent (Clause2)) = N_Compilation_Unit
8142 -- If the unit is a subprogram body that acts as spec,
8143 -- the context clause is shared with the constructed
8144 -- subprogram spec. Clearly there is no redundancy.
8146 if Clause1 = Clause2 then
8150 Unit1 := Unit (Parent (Clause1));
8151 Unit2 := Unit (Parent (Clause2));
8153 -- If both clauses are on same unit, or one is the body
8154 -- of the other, or one of them is in a subunit, report
8155 -- redundancy on the later one.
8157 if Unit1 = Unit2 then
8158 Error_Msg_Sloc := Sloc (Current_Use_Clause (T));
8159 Error_Msg_NE -- CODEFIX
8160 ("& is already use-visible through previous "
8161 & "use_type_clause #?", Clause1, T);
8164 elsif Nkind (Unit1) = N_Subunit then
8165 Error_Msg_Sloc := Sloc (Current_Use_Clause (T));
8166 Error_Msg_NE -- CODEFIX
8167 ("& is already use-visible through previous "
8168 & "use_type_clause #?", Clause1, T);
8171 elsif Nkind_In (Unit2, N_Package_Body, N_Subprogram_Body)
8172 and then Nkind (Unit1) /= Nkind (Unit2)
8173 and then Nkind (Unit1) /= N_Subunit
8175 Error_Msg_Sloc := Sloc (Clause1);
8176 Error_Msg_NE -- CODEFIX
8177 ("& is already use-visible through previous "
8178 & "use_type_clause #?", Current_Use_Clause (T), T);
8182 -- There is a redundant use type clause in a child unit.
8183 -- Determine which of the units is more deeply nested.
8184 -- If a unit is a package instance, retrieve the entity
8185 -- and its scope from the instance spec.
8187 Ent1 := Entity_Of_Unit (Unit1);
8188 Ent2 := Entity_Of_Unit (Unit2);
8190 if Scope (Ent2) = Standard_Standard then
8191 Error_Msg_Sloc := Sloc (Current_Use_Clause (T));
8194 elsif Scope (Ent1) = Standard_Standard then
8195 Error_Msg_Sloc := Sloc (Id);
8198 -- If both units are child units, we determine which one
8199 -- is the descendant by the scope distance to the
8200 -- ultimate parent unit.
8210 and then Present (S2)
8211 and then S1 /= Standard_Standard
8212 and then S2 /= Standard_Standard
8218 if S1 = Standard_Standard then
8219 Error_Msg_Sloc := Sloc (Id);
8222 Error_Msg_Sloc := Sloc (Current_Use_Clause (T));
8228 Error_Msg_NE -- CODEFIX
8229 ("& is already use-visible through previous "
8230 & "use_type_clause #?", Err_No, Id);
8232 -- Case where current use type clause and the use type
8233 -- clause for the type are not both at the compilation unit
8234 -- level. In this case we don't have location information.
8237 Error_Msg_NE -- CODEFIX
8238 ("& is already use-visible through previous "
8239 & "use type clause?", Id, T);
8241 end Use_Clause_Known;
8243 -- Here if Current_Use_Clause is not set for T, another case
8244 -- where we do not have the location information available.
8247 Error_Msg_NE -- CODEFIX
8248 ("& is already use-visible through previous "
8249 & "use type clause?", Id, T);
8252 -- The package where T is declared is already used
8254 elsif In_Use (Scope (T)) then
8255 Error_Msg_Sloc := Sloc (Current_Use_Clause (Scope (T)));
8256 Error_Msg_NE -- CODEFIX
8257 ("& is already use-visible through package use clause #?",
8260 -- The current scope is the package where T is declared
8263 Error_Msg_Node_2 := Scope (T);
8264 Error_Msg_NE -- CODEFIX
8265 ("& is already use-visible inside package &?", Id, T);
8274 procedure Write_Info is
8275 Id : Entity_Id := First_Entity (Current_Scope);
8278 -- No point in dumping standard entities
8280 if Current_Scope = Standard_Standard then
8284 Write_Str ("========================================================");
8286 Write_Str (" Defined Entities in ");
8287 Write_Name (Chars (Current_Scope));
8289 Write_Str ("========================================================");
8293 Write_Str ("-- none --");
8297 while Present (Id) loop
8298 Write_Entity_Info (Id, " ");
8303 if Scope (Current_Scope) = Standard_Standard then
8305 -- Print information on the current unit itself
8307 Write_Entity_Info (Current_Scope, " ");
8320 for J in reverse 1 .. Scope_Stack.Last loop
8321 S := Scope_Stack.Table (J).Entity;
8322 Write_Int (Int (S));
8323 Write_Str (" === ");
8324 Write_Name (Chars (S));
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