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 -- Reject renamings of conversions unless the type is tagged, or
806 -- the conversion is implicit (which can occur for cases of anonymous
807 -- access types in Ada 2012).
809 if Nkind (Nam) = N_Type_Conversion
810 and then Comes_From_Source (Nam)
811 and then not Is_Tagged_Type (T)
814 ("renaming of conversion only allowed for tagged types", Nam);
819 -- If the renamed object is a function call of a limited type,
820 -- the expansion of the renaming is complicated by the presence
821 -- of various temporaries and subtypes that capture constraints
822 -- of the renamed object. Rewrite node as an object declaration,
823 -- whose expansion is simpler. Given that the object is limited
824 -- there is no copy involved and no performance hit.
826 if Nkind (Nam) = N_Function_Call
827 and then Is_Immutably_Limited_Type (Etype (Nam))
828 and then not Is_Constrained (Etype (Nam))
829 and then Comes_From_Source (N)
832 Set_Ekind (Id, E_Constant);
834 Make_Object_Declaration (Loc,
835 Defining_Identifier => Id,
836 Constant_Present => True,
837 Object_Definition => New_Occurrence_Of (Etype (Nam), Loc),
838 Expression => Relocate_Node (Nam)));
842 -- Ada 2012 (AI05-149): Reject renaming of an anonymous access object
843 -- when renaming declaration has a named access type. The Ada 2012
844 -- coverage rules allow an anonymous access type in the context of
845 -- an expected named general access type, but the renaming rules
846 -- require the types to be the same. (An exception is when the type
847 -- of the renaming is also an anonymous access type, which can only
848 -- happen due to a renaming created by the expander.)
850 if Nkind (Nam) = N_Type_Conversion
851 and then not Comes_From_Source (Nam)
852 and then Ekind (Etype (Expression (Nam))) = E_Anonymous_Access_Type
853 and then Ekind (T) /= E_Anonymous_Access_Type
855 Wrong_Type (Expression (Nam), T); -- Should we give better error???
858 -- Check that a class-wide object is not being renamed as an object
859 -- of a specific type. The test for access types is needed to exclude
860 -- cases where the renamed object is a dynamically tagged access
861 -- result, such as occurs in certain expansions.
863 if Is_Tagged_Type (T) then
864 Check_Dynamically_Tagged_Expression
870 -- Ada 2005 (AI-230/AI-254): Access renaming
872 else pragma Assert (Present (Access_Definition (N)));
873 T := Access_Definition
875 N => Access_Definition (N));
879 -- Ada 2005 AI05-105: if the declaration has an anonymous access
880 -- type, the renamed object must also have an anonymous type, and
881 -- this is a name resolution rule. This was implicit in the last part
882 -- of the first sentence in 8.5.1(3/2), and is made explicit by this
885 if not Is_Overloaded (Nam) then
886 if Ekind (Etype (Nam)) /= Ekind (T) then
888 ("expect anonymous access type in object renaming", N);
895 Typ : Entity_Id := Empty;
896 Seen : Boolean := False;
899 Get_First_Interp (Nam, I, It);
900 while Present (It.Typ) loop
902 -- Renaming is ambiguous if more than one candidate
903 -- interpretation is type-conformant with the context.
905 if Ekind (It.Typ) = Ekind (T) then
906 if Ekind (T) = E_Anonymous_Access_Subprogram_Type
909 (Designated_Type (T), Designated_Type (It.Typ))
915 ("ambiguous expression in renaming", Nam);
918 elsif Ekind (T) = E_Anonymous_Access_Type
920 Covers (Designated_Type (T), Designated_Type (It.Typ))
926 ("ambiguous expression in renaming", Nam);
930 if Covers (T, It.Typ) then
932 Set_Etype (Nam, Typ);
933 Set_Is_Overloaded (Nam, False);
937 Get_Next_Interp (I, It);
944 -- Ada 2005 (AI-231): "In the case where the type is defined by an
945 -- access_definition, the renamed entity shall be of an access-to-
946 -- constant type if and only if the access_definition defines an
947 -- access-to-constant type" ARM 8.5.1(4)
949 if Constant_Present (Access_Definition (N))
950 and then not Is_Access_Constant (Etype (Nam))
952 Error_Msg_N ("(Ada 2005): the renamed object is not "
953 & "access-to-constant (RM 8.5.1(6))", N);
955 elsif not Constant_Present (Access_Definition (N))
956 and then Is_Access_Constant (Etype (Nam))
958 Error_Msg_N ("(Ada 2005): the renamed object is not "
959 & "access-to-variable (RM 8.5.1(6))", N);
962 if Is_Access_Subprogram_Type (Etype (Nam)) then
963 Check_Subtype_Conformant
964 (Designated_Type (T), Designated_Type (Etype (Nam)));
966 elsif not Subtypes_Statically_Match
967 (Designated_Type (T),
968 Available_View (Designated_Type (Etype (Nam))))
971 ("subtype of renamed object does not statically match", N);
975 -- Special processing for renaming function return object. Some errors
976 -- and warnings are produced only for calls that come from source.
978 if Nkind (Nam) = N_Function_Call then
981 -- Usage is illegal in Ada 83
984 if Comes_From_Source (Nam) then
986 ("(Ada 83) cannot rename function return object", Nam);
989 -- In Ada 95, warn for odd case of renaming parameterless function
990 -- call if this is not a limited type (where this is useful).
993 if Warn_On_Object_Renames_Function
994 and then No (Parameter_Associations (Nam))
995 and then not Is_Limited_Type (Etype (Nam))
996 and then Comes_From_Source (Nam)
999 ("?renaming function result object is suspicious", Nam);
1001 ("\?function & will be called only once", Nam,
1002 Entity (Name (Nam)));
1003 Error_Msg_N -- CODEFIX
1004 ("\?suggest using an initialized constant object instead",
1011 Check_Constrained_Object;
1013 -- An object renaming requires an exact match of the type. Class-wide
1014 -- matching is not allowed.
1016 if Is_Class_Wide_Type (T)
1017 and then Base_Type (Etype (Nam)) /= Base_Type (T)
1019 Wrong_Type (Nam, T);
1024 -- Ada 2005 (AI-326): Handle wrong use of incomplete type
1026 if Nkind (Nam) = N_Explicit_Dereference
1027 and then Ekind (Etype (T2)) = E_Incomplete_Type
1029 Error_Msg_NE ("invalid use of incomplete type&", Id, T2);
1032 elsif Ekind (Etype (T)) = E_Incomplete_Type then
1033 Error_Msg_NE ("invalid use of incomplete type&", Id, T);
1037 -- Ada 2005 (AI-327)
1039 if Ada_Version >= Ada_2005
1040 and then Nkind (Nam) = N_Attribute_Reference
1041 and then Attribute_Name (Nam) = Name_Priority
1045 elsif Ada_Version >= Ada_2005
1046 and then Nkind (Nam) in N_Has_Entity
1050 Nam_Ent : Entity_Id;
1053 if Nkind (Nam) = N_Attribute_Reference then
1054 Nam_Ent := Entity (Prefix (Nam));
1056 Nam_Ent := Entity (Nam);
1059 Nam_Decl := Parent (Nam_Ent);
1061 if Has_Null_Exclusion (N)
1062 and then not Has_Null_Exclusion (Nam_Decl)
1064 -- Ada 2005 (AI-423): If the object name denotes a generic
1065 -- formal object of a generic unit G, and the object renaming
1066 -- declaration occurs within the body of G or within the body
1067 -- of a generic unit declared within the declarative region
1068 -- of G, then the declaration of the formal object of G must
1069 -- have a null exclusion or a null-excluding subtype.
1071 if Is_Formal_Object (Nam_Ent)
1072 and then In_Generic_Scope (Id)
1074 if not Can_Never_Be_Null (Etype (Nam_Ent)) then
1076 ("renamed formal does not exclude `NULL` "
1077 & "(RM 8.5.1(4.6/2))", N);
1079 elsif In_Package_Body (Scope (Id)) then
1081 ("formal object does not have a null exclusion"
1082 & "(RM 8.5.1(4.6/2))", N);
1085 -- Ada 2005 (AI-423): Otherwise, the subtype of the object name
1086 -- shall exclude null.
1088 elsif not Can_Never_Be_Null (Etype (Nam_Ent)) then
1090 ("renamed object does not exclude `NULL` "
1091 & "(RM 8.5.1(4.6/2))", N);
1093 -- An instance is illegal if it contains a renaming that
1094 -- excludes null, and the actual does not. The renaming
1095 -- declaration has already indicated that the declaration
1096 -- of the renamed actual in the instance will raise
1097 -- constraint_error.
1099 elsif Nkind (Nam_Decl) = N_Object_Declaration
1100 and then In_Instance
1102 (Corresponding_Generic_Association (Nam_Decl))
1103 and then Nkind (Expression (Nam_Decl))
1104 = N_Raise_Constraint_Error
1107 ("renamed actual does not exclude `NULL` "
1108 & "(RM 8.5.1(4.6/2))", N);
1110 -- Finally, if there is a null exclusion, the subtype mark
1111 -- must not be null-excluding.
1113 elsif No (Access_Definition (N))
1114 and then Can_Never_Be_Null (T)
1117 ("`NOT NULL` not allowed (& already excludes null)",
1122 elsif Can_Never_Be_Null (T)
1123 and then not Can_Never_Be_Null (Etype (Nam_Ent))
1126 ("renamed object does not exclude `NULL` "
1127 & "(RM 8.5.1(4.6/2))", N);
1129 elsif Has_Null_Exclusion (N)
1130 and then No (Access_Definition (N))
1131 and then Can_Never_Be_Null (T)
1134 ("`NOT NULL` not allowed (& already excludes null)", N, T);
1139 Set_Ekind (Id, E_Variable);
1141 -- Initialize the object size and alignment. Note that we used to call
1142 -- Init_Size_Align here, but that's wrong for objects which have only
1143 -- an Esize, not an RM_Size field!
1145 Init_Object_Size_Align (Id);
1147 if T = Any_Type or else Etype (Nam) = Any_Type then
1150 -- Verify that the renamed entity is an object or a function call. It
1151 -- may have been rewritten in several ways.
1153 elsif Is_Object_Reference (Nam) then
1154 if Comes_From_Source (N)
1155 and then Is_Dependent_Component_Of_Mutable_Object (Nam)
1158 ("illegal renaming of discriminant-dependent component", Nam);
1161 -- A static function call may have been folded into a literal
1163 elsif Nkind (Original_Node (Nam)) = N_Function_Call
1165 -- When expansion is disabled, attribute reference is not
1166 -- rewritten as function call. Otherwise it may be rewritten
1167 -- as a conversion, so check original node.
1169 or else (Nkind (Original_Node (Nam)) = N_Attribute_Reference
1170 and then Is_Function_Attribute_Name
1171 (Attribute_Name (Original_Node (Nam))))
1173 -- Weird but legal, equivalent to renaming a function call.
1174 -- Illegal if the literal is the result of constant-folding an
1175 -- attribute reference that is not a function.
1177 or else (Is_Entity_Name (Nam)
1178 and then Ekind (Entity (Nam)) = E_Enumeration_Literal
1180 Nkind (Original_Node (Nam)) /= N_Attribute_Reference)
1182 or else (Nkind (Nam) = N_Type_Conversion
1183 and then Is_Tagged_Type (Entity (Subtype_Mark (Nam))))
1187 elsif Nkind (Nam) = N_Type_Conversion then
1189 ("renaming of conversion only allowed for tagged types", Nam);
1191 -- Ada 2005 (AI-327)
1193 elsif Ada_Version >= Ada_2005
1194 and then Nkind (Nam) = N_Attribute_Reference
1195 and then Attribute_Name (Nam) = Name_Priority
1199 -- Allow internally generated x'Reference expression
1201 elsif Nkind (Nam) = N_Reference then
1205 Error_Msg_N ("expect object name in renaming", Nam);
1210 if not Is_Variable (Nam) then
1211 Set_Ekind (Id, E_Constant);
1212 Set_Never_Set_In_Source (Id, True);
1213 Set_Is_True_Constant (Id, True);
1216 Set_Renamed_Object (Id, Nam);
1217 end Analyze_Object_Renaming;
1219 ------------------------------
1220 -- Analyze_Package_Renaming --
1221 ------------------------------
1223 procedure Analyze_Package_Renaming (N : Node_Id) is
1224 New_P : constant Entity_Id := Defining_Entity (N);
1229 if Name (N) = Error then
1233 -- Apply Text_IO kludge here since we may be renaming a child of Text_IO
1235 Text_IO_Kludge (Name (N));
1237 if Current_Scope /= Standard_Standard then
1238 Set_Is_Pure (New_P, Is_Pure (Current_Scope));
1244 if Is_Entity_Name (Name (N)) then
1245 Old_P := Entity (Name (N));
1250 if Etype (Old_P) = Any_Type then
1251 Error_Msg_N ("expect package name in renaming", Name (N));
1253 elsif Ekind (Old_P) /= E_Package
1254 and then not (Ekind (Old_P) = E_Generic_Package
1255 and then In_Open_Scopes (Old_P))
1257 if Ekind (Old_P) = E_Generic_Package then
1259 ("generic package cannot be renamed as a package", Name (N));
1261 Error_Msg_Sloc := Sloc (Old_P);
1263 ("expect package name in renaming, found& declared#",
1267 -- Set basic attributes to minimize cascaded errors
1269 Set_Ekind (New_P, E_Package);
1270 Set_Etype (New_P, Standard_Void_Type);
1272 -- Here for OK package renaming
1275 -- Entities in the old package are accessible through the renaming
1276 -- entity. The simplest implementation is to have both packages share
1279 Set_Ekind (New_P, E_Package);
1280 Set_Etype (New_P, Standard_Void_Type);
1282 if Present (Renamed_Object (Old_P)) then
1283 Set_Renamed_Object (New_P, Renamed_Object (Old_P));
1285 Set_Renamed_Object (New_P, Old_P);
1288 Set_Has_Completion (New_P);
1290 Set_First_Entity (New_P, First_Entity (Old_P));
1291 Set_Last_Entity (New_P, Last_Entity (Old_P));
1292 Set_First_Private_Entity (New_P, First_Private_Entity (Old_P));
1293 Check_Library_Unit_Renaming (N, Old_P);
1294 Generate_Reference (Old_P, Name (N));
1296 -- If the renaming is in the visible part of a package, then we set
1297 -- Renamed_In_Spec for the renamed package, to prevent giving
1298 -- warnings about no entities referenced. Such a warning would be
1299 -- overenthusiastic, since clients can see entities in the renamed
1300 -- package via the visible package renaming.
1303 Ent : constant Entity_Id := Cunit_Entity (Current_Sem_Unit);
1305 if Ekind (Ent) = E_Package
1306 and then not In_Private_Part (Ent)
1307 and then In_Extended_Main_Source_Unit (N)
1308 and then Ekind (Old_P) = E_Package
1310 Set_Renamed_In_Spec (Old_P);
1314 -- If this is the renaming declaration of a package instantiation
1315 -- within itself, it is the declaration that ends the list of actuals
1316 -- for the instantiation. At this point, the subtypes that rename
1317 -- the actuals are flagged as generic, to avoid spurious ambiguities
1318 -- if the actuals for two distinct formals happen to coincide. If
1319 -- the actual is a private type, the subtype has a private completion
1320 -- that is flagged in the same fashion.
1322 -- Resolution is identical to what is was in the original generic.
1323 -- On exit from the generic instance, these are turned into regular
1324 -- subtypes again, so they are compatible with types in their class.
1326 if not Is_Generic_Instance (Old_P) then
1329 Spec := Specification (Unit_Declaration_Node (Old_P));
1332 if Nkind (Spec) = N_Package_Specification
1333 and then Present (Generic_Parent (Spec))
1334 and then Old_P = Current_Scope
1335 and then Chars (New_P) = Chars (Generic_Parent (Spec))
1341 E := First_Entity (Old_P);
1346 and then Nkind (Parent (E)) = N_Subtype_Declaration
1348 Set_Is_Generic_Actual_Type (E);
1350 if Is_Private_Type (E)
1351 and then Present (Full_View (E))
1353 Set_Is_Generic_Actual_Type (Full_View (E));
1362 end Analyze_Package_Renaming;
1364 -------------------------------
1365 -- Analyze_Renamed_Character --
1366 -------------------------------
1368 procedure Analyze_Renamed_Character
1373 C : constant Node_Id := Name (N);
1376 if Ekind (New_S) = E_Function then
1377 Resolve (C, Etype (New_S));
1380 Check_Frozen_Renaming (N, New_S);
1384 Error_Msg_N ("character literal can only be renamed as function", N);
1386 end Analyze_Renamed_Character;
1388 ---------------------------------
1389 -- Analyze_Renamed_Dereference --
1390 ---------------------------------
1392 procedure Analyze_Renamed_Dereference
1397 Nam : constant Node_Id := Name (N);
1398 P : constant Node_Id := Prefix (Nam);
1404 if not Is_Overloaded (P) then
1405 if Ekind (Etype (Nam)) /= E_Subprogram_Type
1406 or else not Type_Conformant (Etype (Nam), New_S)
1408 Error_Msg_N ("designated type does not match specification", P);
1417 Get_First_Interp (Nam, Ind, It);
1419 while Present (It.Nam) loop
1421 if Ekind (It.Nam) = E_Subprogram_Type
1422 and then Type_Conformant (It.Nam, New_S)
1424 if Typ /= Any_Id then
1425 Error_Msg_N ("ambiguous renaming", P);
1432 Get_Next_Interp (Ind, It);
1435 if Typ = Any_Type then
1436 Error_Msg_N ("designated type does not match specification", P);
1441 Check_Frozen_Renaming (N, New_S);
1445 end Analyze_Renamed_Dereference;
1447 ---------------------------
1448 -- Analyze_Renamed_Entry --
1449 ---------------------------
1451 procedure Analyze_Renamed_Entry
1456 Nam : constant Node_Id := Name (N);
1457 Sel : constant Node_Id := Selector_Name (Nam);
1461 if Entity (Sel) = Any_Id then
1463 -- Selector is undefined on prefix. Error emitted already
1465 Set_Has_Completion (New_S);
1469 -- Otherwise find renamed entity and build body of New_S as a call to it
1471 Old_S := Find_Renamed_Entity (N, Selector_Name (Nam), New_S);
1473 if Old_S = Any_Id then
1474 Error_Msg_N (" no subprogram or entry matches specification", N);
1477 Check_Subtype_Conformant (New_S, Old_S, N);
1478 Generate_Reference (New_S, Defining_Entity (N), 'b');
1479 Style.Check_Identifier (Defining_Entity (N), New_S);
1482 -- Only mode conformance required for a renaming_as_declaration
1484 Check_Mode_Conformant (New_S, Old_S, N);
1487 Inherit_Renamed_Profile (New_S, Old_S);
1489 -- The prefix can be an arbitrary expression that yields a task type,
1490 -- so it must be resolved.
1492 Resolve (Prefix (Nam), Scope (Old_S));
1495 Set_Convention (New_S, Convention (Old_S));
1496 Set_Has_Completion (New_S, Inside_A_Generic);
1499 Check_Frozen_Renaming (N, New_S);
1501 end Analyze_Renamed_Entry;
1503 -----------------------------------
1504 -- Analyze_Renamed_Family_Member --
1505 -----------------------------------
1507 procedure Analyze_Renamed_Family_Member
1512 Nam : constant Node_Id := Name (N);
1513 P : constant Node_Id := Prefix (Nam);
1517 if (Is_Entity_Name (P) and then Ekind (Entity (P)) = E_Entry_Family)
1518 or else (Nkind (P) = N_Selected_Component
1520 Ekind (Entity (Selector_Name (P))) = E_Entry_Family)
1522 if Is_Entity_Name (P) then
1523 Old_S := Entity (P);
1525 Old_S := Entity (Selector_Name (P));
1528 if not Entity_Matches_Spec (Old_S, New_S) then
1529 Error_Msg_N ("entry family does not match specification", N);
1532 Check_Subtype_Conformant (New_S, Old_S, N);
1533 Generate_Reference (New_S, Defining_Entity (N), 'b');
1534 Style.Check_Identifier (Defining_Entity (N), New_S);
1538 Error_Msg_N ("no entry family matches specification", N);
1541 Set_Has_Completion (New_S, Inside_A_Generic);
1544 Check_Frozen_Renaming (N, New_S);
1546 end Analyze_Renamed_Family_Member;
1548 -----------------------------------------
1549 -- Analyze_Renamed_Primitive_Operation --
1550 -----------------------------------------
1552 procedure Analyze_Renamed_Primitive_Operation
1561 Ctyp : Conformance_Type) return Boolean;
1562 -- Verify that the signatures of the renamed entity and the new entity
1563 -- match. The first formal of the renamed entity is skipped because it
1564 -- is the target object in any subsequent call.
1568 Ctyp : Conformance_Type) return Boolean
1574 if Ekind (Subp) /= Ekind (New_S) then
1578 Old_F := Next_Formal (First_Formal (Subp));
1579 New_F := First_Formal (New_S);
1580 while Present (Old_F) and then Present (New_F) loop
1581 if not Conforming_Types (Etype (Old_F), Etype (New_F), Ctyp) then
1585 if Ctyp >= Mode_Conformant
1586 and then Ekind (Old_F) /= Ekind (New_F)
1591 Next_Formal (New_F);
1592 Next_Formal (Old_F);
1599 if not Is_Overloaded (Selector_Name (Name (N))) then
1600 Old_S := Entity (Selector_Name (Name (N)));
1602 if not Conforms (Old_S, Type_Conformant) then
1607 -- Find the operation that matches the given signature
1615 Get_First_Interp (Selector_Name (Name (N)), Ind, It);
1617 while Present (It.Nam) loop
1618 if Conforms (It.Nam, Type_Conformant) then
1622 Get_Next_Interp (Ind, It);
1627 if Old_S = Any_Id then
1628 Error_Msg_N (" no subprogram or entry matches specification", N);
1632 if not Conforms (Old_S, Subtype_Conformant) then
1633 Error_Msg_N ("subtype conformance error in renaming", N);
1636 Generate_Reference (New_S, Defining_Entity (N), 'b');
1637 Style.Check_Identifier (Defining_Entity (N), New_S);
1640 -- Only mode conformance required for a renaming_as_declaration
1642 if not Conforms (Old_S, Mode_Conformant) then
1643 Error_Msg_N ("mode conformance error in renaming", N);
1647 -- Inherit_Renamed_Profile (New_S, Old_S);
1649 -- The prefix can be an arbitrary expression that yields an
1650 -- object, so it must be resolved.
1652 Resolve (Prefix (Name (N)));
1654 end Analyze_Renamed_Primitive_Operation;
1656 ---------------------------------
1657 -- Analyze_Subprogram_Renaming --
1658 ---------------------------------
1660 procedure Analyze_Subprogram_Renaming (N : Node_Id) is
1661 Formal_Spec : constant Node_Id := Corresponding_Formal_Spec (N);
1662 Is_Actual : constant Boolean := Present (Formal_Spec);
1663 Inst_Node : Node_Id := Empty;
1664 Nam : constant Node_Id := Name (N);
1666 Old_S : Entity_Id := Empty;
1667 Rename_Spec : Entity_Id;
1668 Save_AV : constant Ada_Version_Type := Ada_Version;
1669 Save_AV_Exp : constant Ada_Version_Type := Ada_Version_Explicit;
1670 Spec : constant Node_Id := Specification (N);
1672 procedure Check_Null_Exclusion
1675 -- Ada 2005 (AI-423): Given renaming Ren of subprogram Sub, check the
1676 -- following AI rules:
1678 -- If Ren is a renaming of a formal subprogram and one of its
1679 -- parameters has a null exclusion, then the corresponding formal
1680 -- in Sub must also have one. Otherwise the subtype of the Sub's
1681 -- formal parameter must exclude null.
1683 -- If Ren is a renaming of a formal function and its return
1684 -- profile has a null exclusion, then Sub's return profile must
1685 -- have one. Otherwise the subtype of Sub's return profile must
1688 function Original_Subprogram (Subp : Entity_Id) return Entity_Id;
1689 -- Find renamed entity when the declaration is a renaming_as_body and
1690 -- the renamed entity may itself be a renaming_as_body. Used to enforce
1691 -- rule that a renaming_as_body is illegal if the declaration occurs
1692 -- before the subprogram it completes is frozen, and renaming indirectly
1693 -- renames the subprogram itself.(Defect Report 8652/0027).
1695 function Check_Class_Wide_Actual return Entity_Id;
1696 -- AI05-0071: In an instance, if the actual for a formal type FT with
1697 -- unknown discriminants is a class-wide type CT, and the generic has
1698 -- a formal subprogram with a box for a primitive operation of FT,
1699 -- then the corresponding actual subprogram denoted by the default is a
1700 -- class-wide operation whose body is a dispatching call. We replace the
1701 -- generated renaming declaration:
1703 -- procedure P (X : CT) renames P;
1705 -- by a different renaming and a class-wide operation:
1707 -- procedure Pr (X : T) renames P; -- renames primitive operation
1708 -- procedure P (X : CT); -- class-wide operation
1710 -- procedure P (X : CT) is begin Pr (X); end; -- dispatching call
1712 -- This rule only applies if there is no explicit visible class-wide
1713 -- operation at the point of the instantiation.
1715 function Has_Class_Wide_Actual return Boolean;
1716 -- Ada 2012 (AI05-071, AI05-0131): True if N is the renaming for a
1717 -- defaulted formal subprogram when the actual for the controlling
1718 -- formal type is class-wide.
1720 -----------------------------
1721 -- Check_Class_Wide_Actual --
1722 -----------------------------
1724 function Check_Class_Wide_Actual return Entity_Id is
1725 Loc : constant Source_Ptr := Sloc (N);
1728 Formal_Type : Entity_Id;
1729 Actual_Type : Entity_Id;
1734 function Make_Call (Prim_Op : Entity_Id) return Node_Id;
1735 -- Build dispatching call for body of class-wide operation
1737 function Make_Spec return Node_Id;
1738 -- Create subprogram specification for declaration and body of
1739 -- class-wide operation, using signature of renaming declaration.
1745 function Make_Call (Prim_Op : Entity_Id) return Node_Id is
1750 Actuals := New_List;
1751 F := First (Parameter_Specifications (Specification (New_Decl)));
1752 while Present (F) loop
1754 Make_Identifier (Loc, Chars (Defining_Identifier (F))));
1758 if Ekind_In (Prim_Op, E_Function, E_Operator) then
1759 return Make_Simple_Return_Statement (Loc,
1761 Make_Function_Call (Loc,
1762 Name => New_Occurrence_Of (Prim_Op, Loc),
1763 Parameter_Associations => Actuals));
1766 Make_Procedure_Call_Statement (Loc,
1767 Name => New_Occurrence_Of (Prim_Op, Loc),
1768 Parameter_Associations => Actuals);
1776 function Make_Spec return Node_Id is
1777 Param_Specs : constant List_Id := Copy_Parameter_List (New_S);
1780 if Ekind (New_S) = E_Procedure then
1782 Make_Procedure_Specification (Loc,
1783 Defining_Unit_Name =>
1784 Make_Defining_Identifier (Loc,
1785 Chars (Defining_Unit_Name (Spec))),
1786 Parameter_Specifications => Param_Specs);
1789 Make_Function_Specification (Loc,
1790 Defining_Unit_Name =>
1791 Make_Defining_Identifier (Loc,
1792 Chars (Defining_Unit_Name (Spec))),
1793 Parameter_Specifications => Param_Specs,
1794 Result_Definition =>
1795 New_Copy_Tree (Result_Definition (Spec)));
1799 -- Start of processing for Check_Class_Wide_Actual
1803 Formal_Type := Empty;
1804 Actual_Type := Empty;
1806 F := First_Formal (Formal_Spec);
1807 while Present (F) loop
1808 if Has_Unknown_Discriminants (Etype (F))
1809 and then not Is_Class_Wide_Type (Etype (F))
1810 and then Is_Class_Wide_Type (Get_Instance_Of (Etype (F)))
1812 Formal_Type := Etype (F);
1813 Actual_Type := Etype (Get_Instance_Of (Formal_Type));
1820 if Present (Formal_Type) then
1822 -- Create declaration and body for class-wide operation
1825 Make_Subprogram_Declaration (Loc, Specification => Make_Spec);
1828 Make_Subprogram_Body (Loc,
1829 Specification => Make_Spec,
1830 Declarations => No_List,
1831 Handled_Statement_Sequence =>
1832 Make_Handled_Sequence_Of_Statements (Loc, New_List));
1834 -- Modify Spec and create internal name for renaming of primitive
1837 Set_Defining_Unit_Name (Spec, Make_Temporary (Loc, 'R'));
1838 F := First (Parameter_Specifications (Spec));
1839 while Present (F) loop
1840 if Nkind (Parameter_Type (F)) = N_Identifier
1841 and then Is_Class_Wide_Type (Entity (Parameter_Type (F)))
1843 Set_Parameter_Type (F, New_Occurrence_Of (Actual_Type, Loc));
1848 New_S := Analyze_Subprogram_Specification (Spec);
1849 Result := Find_Renamed_Entity (N, Name (N), New_S, Is_Actual);
1852 if Result /= Any_Id then
1853 Insert_Before (N, New_Decl);
1856 -- Add dispatching call to body of class-wide operation
1858 Append (Make_Call (Result),
1859 Statements (Handled_Statement_Sequence (New_Body)));
1861 -- The generated body does not freeze. It is analyzed when the
1862 -- generated operation is frozen.
1864 Append_Freeze_Action (Defining_Entity (New_Decl), New_Body);
1866 Result := Defining_Entity (New_Decl);
1869 -- Return the class-wide operation if one was created
1872 end Check_Class_Wide_Actual;
1874 --------------------------
1875 -- Check_Null_Exclusion --
1876 --------------------------
1878 procedure Check_Null_Exclusion
1882 Ren_Formal : Entity_Id;
1883 Sub_Formal : Entity_Id;
1888 Ren_Formal := First_Formal (Ren);
1889 Sub_Formal := First_Formal (Sub);
1890 while Present (Ren_Formal)
1891 and then Present (Sub_Formal)
1893 if Has_Null_Exclusion (Parent (Ren_Formal))
1895 not (Has_Null_Exclusion (Parent (Sub_Formal))
1896 or else Can_Never_Be_Null (Etype (Sub_Formal)))
1899 ("`NOT NULL` required for parameter &",
1900 Parent (Sub_Formal), Sub_Formal);
1903 Next_Formal (Ren_Formal);
1904 Next_Formal (Sub_Formal);
1907 -- Return profile check
1909 if Nkind (Parent (Ren)) = N_Function_Specification
1910 and then Nkind (Parent (Sub)) = N_Function_Specification
1911 and then Has_Null_Exclusion (Parent (Ren))
1913 not (Has_Null_Exclusion (Parent (Sub))
1914 or else Can_Never_Be_Null (Etype (Sub)))
1917 ("return must specify `NOT NULL`",
1918 Result_Definition (Parent (Sub)));
1920 end Check_Null_Exclusion;
1922 ---------------------------
1923 -- Has_Class_Wide_Actual --
1924 ---------------------------
1926 function Has_Class_Wide_Actual return Boolean is
1932 and then Nkind (Nam) in N_Has_Entity
1933 and then Present (Entity (Nam))
1934 and then Is_Dispatching_Operation (Entity (Nam))
1936 F_Nam := First_Entity (Entity (Nam));
1937 F_Spec := First_Formal (Formal_Spec);
1938 while Present (F_Nam)
1939 and then Present (F_Spec)
1941 if Is_Controlling_Formal (F_Nam)
1942 and then Has_Unknown_Discriminants (Etype (F_Spec))
1943 and then not Is_Class_Wide_Type (Etype (F_Spec))
1944 and then Is_Class_Wide_Type (Get_Instance_Of (Etype (F_Spec)))
1949 Next_Entity (F_Nam);
1950 Next_Formal (F_Spec);
1955 end Has_Class_Wide_Actual;
1957 -------------------------
1958 -- Original_Subprogram --
1959 -------------------------
1961 function Original_Subprogram (Subp : Entity_Id) return Entity_Id is
1962 Orig_Decl : Node_Id;
1963 Orig_Subp : Entity_Id;
1966 -- First case: renamed entity is itself a renaming
1968 if Present (Alias (Subp)) then
1969 return Alias (Subp);
1972 Nkind (Unit_Declaration_Node (Subp)) = N_Subprogram_Declaration
1974 (Corresponding_Body (Unit_Declaration_Node (Subp)))
1976 -- Check if renamed entity is a renaming_as_body
1979 Unit_Declaration_Node
1980 (Corresponding_Body (Unit_Declaration_Node (Subp)));
1982 if Nkind (Orig_Decl) = N_Subprogram_Renaming_Declaration then
1983 Orig_Subp := Entity (Name (Orig_Decl));
1985 if Orig_Subp = Rename_Spec then
1987 -- Circularity detected
1992 return (Original_Subprogram (Orig_Subp));
2000 end Original_Subprogram;
2002 CW_Actual : constant Boolean := Has_Class_Wide_Actual;
2003 -- Ada 2012 (AI05-071, AI05-0131): True if the renaming is for a
2004 -- defaulted formal subprogram when the actual for a related formal
2005 -- type is class-wide.
2007 -- Start of processing for Analyze_Subprogram_Renaming
2010 -- We must test for the attribute renaming case before the Analyze
2011 -- call because otherwise Sem_Attr will complain that the attribute
2012 -- is missing an argument when it is analyzed.
2014 if Nkind (Nam) = N_Attribute_Reference then
2016 -- In the case of an abstract formal subprogram association, rewrite
2017 -- an actual given by a stream attribute as the name of the
2018 -- corresponding stream primitive of the type.
2020 -- In a generic context the stream operations are not generated, and
2021 -- this must be treated as a normal attribute reference, to be
2022 -- expanded in subsequent instantiations.
2024 if Is_Actual and then Is_Abstract_Subprogram (Formal_Spec)
2025 and then Full_Expander_Active
2028 Stream_Prim : Entity_Id;
2029 Prefix_Type : constant Entity_Id := Entity (Prefix (Nam));
2032 -- The class-wide forms of the stream attributes are not
2033 -- primitive dispatching operations (even though they
2034 -- internally dispatch to a stream attribute).
2036 if Is_Class_Wide_Type (Prefix_Type) then
2038 ("attribute must be a primitive dispatching operation",
2043 -- Retrieve the primitive subprogram associated with the
2044 -- attribute. This can only be a stream attribute, since those
2045 -- are the only ones that are dispatching (and the actual for
2046 -- an abstract formal subprogram must be dispatching
2050 case Attribute_Name (Nam) is
2053 Find_Prim_Op (Prefix_Type, TSS_Stream_Input);
2056 Find_Prim_Op (Prefix_Type, TSS_Stream_Output);
2059 Find_Prim_Op (Prefix_Type, TSS_Stream_Read);
2062 Find_Prim_Op (Prefix_Type, TSS_Stream_Write);
2065 ("attribute must be a primitive"
2066 & " dispatching operation", Nam);
2072 -- If no operation was found, and the type is limited,
2073 -- the user should have defined one.
2075 when Program_Error =>
2076 if Is_Limited_Type (Prefix_Type) then
2078 ("stream operation not defined for type&",
2082 -- Otherwise, compiler should have generated default
2089 -- Rewrite the attribute into the name of its corresponding
2090 -- primitive dispatching subprogram. We can then proceed with
2091 -- the usual processing for subprogram renamings.
2094 Prim_Name : constant Node_Id :=
2095 Make_Identifier (Sloc (Nam),
2096 Chars => Chars (Stream_Prim));
2098 Set_Entity (Prim_Name, Stream_Prim);
2099 Rewrite (Nam, Prim_Name);
2104 -- Normal processing for a renaming of an attribute
2107 Attribute_Renaming (N);
2112 -- Check whether this declaration corresponds to the instantiation
2113 -- of a formal subprogram.
2115 -- If this is an instantiation, the corresponding actual is frozen and
2116 -- error messages can be made more precise. If this is a default
2117 -- subprogram, the entity is already established in the generic, and is
2118 -- not retrieved by visibility. If it is a default with a box, the
2119 -- candidate interpretations, if any, have been collected when building
2120 -- the renaming declaration. If overloaded, the proper interpretation is
2121 -- determined in Find_Renamed_Entity. If the entity is an operator,
2122 -- Find_Renamed_Entity applies additional visibility checks.
2125 Inst_Node := Unit_Declaration_Node (Formal_Spec);
2127 -- Check whether the renaming is for a defaulted actual subprogram
2128 -- with a class-wide actual.
2131 New_S := Analyze_Subprogram_Specification (Spec);
2132 Old_S := Check_Class_Wide_Actual;
2134 elsif Is_Entity_Name (Nam)
2135 and then Present (Entity (Nam))
2136 and then not Comes_From_Source (Nam)
2137 and then not Is_Overloaded (Nam)
2139 Old_S := Entity (Nam);
2140 New_S := Analyze_Subprogram_Specification (Spec);
2144 if Ekind (Entity (Nam)) = E_Operator then
2148 if Box_Present (Inst_Node) then
2149 Old_S := Find_Renamed_Entity (N, Name (N), New_S, Is_Actual);
2151 -- If there is an immediately visible homonym of the operator
2152 -- and the declaration has a default, this is worth a warning
2153 -- because the user probably did not intend to get the pre-
2154 -- defined operator, visible in the generic declaration. To
2155 -- find if there is an intended candidate, analyze the renaming
2156 -- again in the current context.
2158 elsif Scope (Old_S) = Standard_Standard
2159 and then Present (Default_Name (Inst_Node))
2162 Decl : constant Node_Id := New_Copy_Tree (N);
2166 Set_Entity (Name (Decl), Empty);
2167 Analyze (Name (Decl));
2169 Find_Renamed_Entity (Decl, Name (Decl), New_S, True);
2172 and then In_Open_Scopes (Scope (Hidden))
2173 and then Is_Immediately_Visible (Hidden)
2174 and then Comes_From_Source (Hidden)
2175 and then Hidden /= Old_S
2177 Error_Msg_Sloc := Sloc (Hidden);
2178 Error_Msg_N ("?default subprogram is resolved " &
2179 "in the generic declaration " &
2180 "(RM 12.6(17))", N);
2181 Error_Msg_NE ("\?and will not use & #", N, Hidden);
2189 New_S := Analyze_Subprogram_Specification (Spec);
2193 -- Renamed entity must be analyzed first, to avoid being hidden by
2194 -- new name (which might be the same in a generic instance).
2198 -- The renaming defines a new overloaded entity, which is analyzed
2199 -- like a subprogram declaration.
2201 New_S := Analyze_Subprogram_Specification (Spec);
2204 if Current_Scope /= Standard_Standard then
2205 Set_Is_Pure (New_S, Is_Pure (Current_Scope));
2208 Rename_Spec := Find_Corresponding_Spec (N);
2210 -- Case of Renaming_As_Body
2212 if Present (Rename_Spec) then
2214 -- Renaming declaration is the completion of the declaration of
2215 -- Rename_Spec. We build an actual body for it at the freezing point.
2217 Set_Corresponding_Spec (N, Rename_Spec);
2219 -- Deal with special case of stream functions of abstract types
2222 if Nkind (Unit_Declaration_Node (Rename_Spec)) =
2223 N_Abstract_Subprogram_Declaration
2225 -- Input stream functions are abstract if the object type is
2226 -- abstract. Similarly, all default stream functions for an
2227 -- interface type are abstract. However, these subprograms may
2228 -- receive explicit declarations in representation clauses, making
2229 -- the attribute subprograms usable as defaults in subsequent
2231 -- In this case we rewrite the declaration to make the subprogram
2232 -- non-abstract. We remove the previous declaration, and insert
2233 -- the new one at the point of the renaming, to prevent premature
2234 -- access to unfrozen types. The new declaration reuses the
2235 -- specification of the previous one, and must not be analyzed.
2238 (Is_Primitive (Entity (Nam))
2240 Is_Abstract_Type (Find_Dispatching_Type (Entity (Nam))));
2242 Old_Decl : constant Node_Id :=
2243 Unit_Declaration_Node (Rename_Spec);
2244 New_Decl : constant Node_Id :=
2245 Make_Subprogram_Declaration (Sloc (N),
2247 Relocate_Node (Specification (Old_Decl)));
2250 Insert_After (N, New_Decl);
2251 Set_Is_Abstract_Subprogram (Rename_Spec, False);
2252 Set_Analyzed (New_Decl);
2256 Set_Corresponding_Body (Unit_Declaration_Node (Rename_Spec), New_S);
2258 if Ada_Version = Ada_83 and then Comes_From_Source (N) then
2259 Error_Msg_N ("(Ada 83) renaming cannot serve as a body", N);
2262 Set_Convention (New_S, Convention (Rename_Spec));
2263 Check_Fully_Conformant (New_S, Rename_Spec);
2264 Set_Public_Status (New_S);
2266 -- The specification does not introduce new formals, but only
2267 -- repeats the formals of the original subprogram declaration.
2268 -- For cross-reference purposes, and for refactoring tools, we
2269 -- treat the formals of the renaming declaration as body formals.
2271 Reference_Body_Formals (Rename_Spec, New_S);
2273 -- Indicate that the entity in the declaration functions like the
2274 -- corresponding body, and is not a new entity. The body will be
2275 -- constructed later at the freeze point, so indicate that the
2276 -- completion has not been seen yet.
2278 Set_Ekind (New_S, E_Subprogram_Body);
2279 New_S := Rename_Spec;
2280 Set_Has_Completion (Rename_Spec, False);
2282 -- Ada 2005: check overriding indicator
2284 if Present (Overridden_Operation (Rename_Spec)) then
2285 if Must_Not_Override (Specification (N)) then
2287 ("subprogram& overrides inherited operation",
2290 Style_Check and then not Must_Override (Specification (N))
2292 Style.Missing_Overriding (N, Rename_Spec);
2295 elsif Must_Override (Specification (N)) then
2296 Error_Msg_NE ("subprogram& is not overriding", N, Rename_Spec);
2299 -- Normal subprogram renaming (not renaming as body)
2302 Generate_Definition (New_S);
2303 New_Overloaded_Entity (New_S);
2305 if Is_Entity_Name (Nam)
2306 and then Is_Intrinsic_Subprogram (Entity (Nam))
2310 Check_Delayed_Subprogram (New_S);
2314 -- There is no need for elaboration checks on the new entity, which may
2315 -- be called before the next freezing point where the body will appear.
2316 -- Elaboration checks refer to the real entity, not the one created by
2317 -- the renaming declaration.
2319 Set_Kill_Elaboration_Checks (New_S, True);
2321 if Etype (Nam) = Any_Type then
2322 Set_Has_Completion (New_S);
2325 elsif Nkind (Nam) = N_Selected_Component then
2327 -- A prefix of the form A.B can designate an entry of task A, a
2328 -- protected operation of protected object A, or finally a primitive
2329 -- operation of object A. In the later case, A is an object of some
2330 -- tagged type, or an access type that denotes one such. To further
2331 -- distinguish these cases, note that the scope of a task entry or
2332 -- protected operation is type of the prefix.
2334 -- The prefix could be an overloaded function call that returns both
2335 -- kinds of operations. This overloading pathology is left to the
2336 -- dedicated reader ???
2339 T : constant Entity_Id := Etype (Prefix (Nam));
2348 Is_Tagged_Type (Designated_Type (T))))
2349 and then Scope (Entity (Selector_Name (Nam))) /= T
2351 Analyze_Renamed_Primitive_Operation
2352 (N, New_S, Present (Rename_Spec));
2356 -- Renamed entity is an entry or protected operation. For those
2357 -- cases an explicit body is built (at the point of freezing of
2358 -- this entity) that contains a call to the renamed entity.
2360 -- This is not allowed for renaming as body if the renamed
2361 -- spec is already frozen (see RM 8.5.4(5) for details).
2363 if Present (Rename_Spec)
2364 and then Is_Frozen (Rename_Spec)
2367 ("renaming-as-body cannot rename entry as subprogram", N);
2369 ("\since & is already frozen (RM 8.5.4(5))",
2372 Analyze_Renamed_Entry (N, New_S, Present (Rename_Spec));
2379 elsif Nkind (Nam) = N_Explicit_Dereference then
2381 -- Renamed entity is designated by access_to_subprogram expression.
2382 -- Must build body to encapsulate call, as in the entry case.
2384 Analyze_Renamed_Dereference (N, New_S, Present (Rename_Spec));
2387 elsif Nkind (Nam) = N_Indexed_Component then
2388 Analyze_Renamed_Family_Member (N, New_S, Present (Rename_Spec));
2391 elsif Nkind (Nam) = N_Character_Literal then
2392 Analyze_Renamed_Character (N, New_S, Present (Rename_Spec));
2395 elsif not Is_Entity_Name (Nam)
2396 or else not Is_Overloadable (Entity (Nam))
2398 Error_Msg_N ("expect valid subprogram name in renaming", N);
2402 -- Find the renamed entity that matches the given specification. Disable
2403 -- Ada_83 because there is no requirement of full conformance between
2404 -- renamed entity and new entity, even though the same circuit is used.
2406 -- This is a bit of a kludge, which introduces a really irregular use of
2407 -- Ada_Version[_Explicit]. Would be nice to find cleaner way to do this
2410 Ada_Version := Ada_Version_Type'Max (Ada_Version, Ada_95);
2411 Ada_Version_Explicit := Ada_Version;
2414 Old_S := Find_Renamed_Entity (N, Name (N), New_S, Is_Actual);
2416 -- The visible operation may be an inherited abstract operation that
2417 -- was overridden in the private part, in which case a call will
2418 -- dispatch to the overriding operation. Use the overriding one in
2419 -- the renaming declaration, to prevent spurious errors below.
2421 if Is_Overloadable (Old_S)
2422 and then Is_Abstract_Subprogram (Old_S)
2423 and then No (DTC_Entity (Old_S))
2424 and then Present (Alias (Old_S))
2425 and then not Is_Abstract_Subprogram (Alias (Old_S))
2426 and then Present (Overridden_Operation (Alias (Old_S)))
2428 Old_S := Alias (Old_S);
2431 -- When the renamed subprogram is overloaded and used as an actual
2432 -- of a generic, its entity is set to the first available homonym.
2433 -- We must first disambiguate the name, then set the proper entity.
2435 if Is_Actual and then Is_Overloaded (Nam) then
2436 Set_Entity (Nam, Old_S);
2440 -- Most common case: subprogram renames subprogram. No body is generated
2441 -- in this case, so we must indicate the declaration is complete as is.
2442 -- and inherit various attributes of the renamed subprogram.
2444 if No (Rename_Spec) then
2445 Set_Has_Completion (New_S);
2446 Set_Is_Imported (New_S, Is_Imported (Entity (Nam)));
2447 Set_Is_Pure (New_S, Is_Pure (Entity (Nam)));
2448 Set_Is_Preelaborated (New_S, Is_Preelaborated (Entity (Nam)));
2450 -- Ada 2005 (AI-423): Check the consistency of null exclusions
2451 -- between a subprogram and its correct renaming.
2453 -- Note: the Any_Id check is a guard that prevents compiler crashes
2454 -- when performing a null exclusion check between a renaming and a
2455 -- renamed subprogram that has been found to be illegal.
2457 if Ada_Version >= Ada_2005
2458 and then Entity (Nam) /= Any_Id
2460 Check_Null_Exclusion
2462 Sub => Entity (Nam));
2465 -- Enforce the Ada 2005 rule that the renamed entity cannot require
2466 -- overriding. The flag Requires_Overriding is set very selectively
2467 -- and misses some other illegal cases. The additional conditions
2468 -- checked below are sufficient but not necessary ???
2470 -- The rule does not apply to the renaming generated for an actual
2471 -- subprogram in an instance.
2476 -- Guard against previous errors, and omit renamings of predefined
2479 elsif not Ekind_In (Old_S, E_Function, E_Procedure) then
2482 elsif Requires_Overriding (Old_S)
2484 (Is_Abstract_Subprogram (Old_S)
2485 and then Present (Find_Dispatching_Type (Old_S))
2487 not Is_Abstract_Type (Find_Dispatching_Type (Old_S)))
2490 ("renamed entity cannot be "
2491 & "subprogram that requires overriding (RM 8.5.4 (5.1))", N);
2495 if Old_S /= Any_Id then
2496 if Is_Actual and then From_Default (N) then
2498 -- This is an implicit reference to the default actual
2500 Generate_Reference (Old_S, Nam, Typ => 'i', Force => True);
2503 Generate_Reference (Old_S, Nam);
2506 -- For a renaming-as-body, require subtype conformance, but if the
2507 -- declaration being completed has not been frozen, then inherit the
2508 -- convention of the renamed subprogram prior to checking conformance
2509 -- (unless the renaming has an explicit convention established; the
2510 -- rule stated in the RM doesn't seem to address this ???).
2512 if Present (Rename_Spec) then
2513 Generate_Reference (Rename_Spec, Defining_Entity (Spec), 'b');
2514 Style.Check_Identifier (Defining_Entity (Spec), Rename_Spec);
2516 if not Is_Frozen (Rename_Spec) then
2517 if not Has_Convention_Pragma (Rename_Spec) then
2518 Set_Convention (New_S, Convention (Old_S));
2521 if Ekind (Old_S) /= E_Operator then
2522 Check_Mode_Conformant (New_S, Old_S, Spec);
2525 if Original_Subprogram (Old_S) = Rename_Spec then
2526 Error_Msg_N ("unfrozen subprogram cannot rename itself ", N);
2529 Check_Subtype_Conformant (New_S, Old_S, Spec);
2532 Check_Frozen_Renaming (N, Rename_Spec);
2534 -- Check explicitly that renamed entity is not intrinsic, because
2535 -- in a generic the renamed body is not built. In this case,
2536 -- the renaming_as_body is a completion.
2538 if Inside_A_Generic then
2539 if Is_Frozen (Rename_Spec)
2540 and then Is_Intrinsic_Subprogram (Old_S)
2543 ("subprogram in renaming_as_body cannot be intrinsic",
2547 Set_Has_Completion (Rename_Spec);
2550 elsif Ekind (Old_S) /= E_Operator then
2552 -- If this a defaulted subprogram for a class-wide actual there is
2553 -- no check for mode conformance, given that the signatures don't
2554 -- match (the source mentions T but the actual mentions T'Class).
2559 Check_Mode_Conformant (New_S, Old_S);
2563 and then Error_Posted (New_S)
2565 Error_Msg_NE ("invalid actual subprogram: & #!", N, Old_S);
2569 if No (Rename_Spec) then
2571 -- The parameter profile of the new entity is that of the renamed
2572 -- entity: the subtypes given in the specification are irrelevant.
2574 Inherit_Renamed_Profile (New_S, Old_S);
2576 -- A call to the subprogram is transformed into a call to the
2577 -- renamed entity. This is transitive if the renamed entity is
2578 -- itself a renaming.
2580 if Present (Alias (Old_S)) then
2581 Set_Alias (New_S, Alias (Old_S));
2583 Set_Alias (New_S, Old_S);
2586 -- Note that we do not set Is_Intrinsic_Subprogram if we have a
2587 -- renaming as body, since the entity in this case is not an
2588 -- intrinsic (it calls an intrinsic, but we have a real body for
2589 -- this call, and it is in this body that the required intrinsic
2590 -- processing will take place).
2592 -- Also, if this is a renaming of inequality, the renamed operator
2593 -- is intrinsic, but what matters is the corresponding equality
2594 -- operator, which may be user-defined.
2596 Set_Is_Intrinsic_Subprogram
2598 Is_Intrinsic_Subprogram (Old_S)
2600 (Chars (Old_S) /= Name_Op_Ne
2601 or else Ekind (Old_S) = E_Operator
2603 Is_Intrinsic_Subprogram
2604 (Corresponding_Equality (Old_S))));
2606 if Ekind (Alias (New_S)) = E_Operator then
2607 Set_Has_Delayed_Freeze (New_S, False);
2610 -- If the renaming corresponds to an association for an abstract
2611 -- formal subprogram, then various attributes must be set to
2612 -- indicate that the renaming is an abstract dispatching operation
2613 -- with a controlling type.
2615 if Is_Actual and then Is_Abstract_Subprogram (Formal_Spec) then
2617 -- Mark the renaming as abstract here, so Find_Dispatching_Type
2618 -- see it as corresponding to a generic association for a
2619 -- formal abstract subprogram
2621 Set_Is_Abstract_Subprogram (New_S);
2624 New_S_Ctrl_Type : constant Entity_Id :=
2625 Find_Dispatching_Type (New_S);
2626 Old_S_Ctrl_Type : constant Entity_Id :=
2627 Find_Dispatching_Type (Old_S);
2630 if Old_S_Ctrl_Type /= New_S_Ctrl_Type then
2632 ("actual must be dispatching subprogram for type&",
2633 Nam, New_S_Ctrl_Type);
2636 Set_Is_Dispatching_Operation (New_S);
2637 Check_Controlling_Formals (New_S_Ctrl_Type, New_S);
2639 -- If the actual in the formal subprogram is itself a
2640 -- formal abstract subprogram association, there's no
2641 -- dispatch table component or position to inherit.
2643 if Present (DTC_Entity (Old_S)) then
2644 Set_DTC_Entity (New_S, DTC_Entity (Old_S));
2645 Set_DT_Position (New_S, DT_Position (Old_S));
2653 and then (Old_S = New_S
2654 or else (Nkind (Nam) /= N_Expanded_Name
2655 and then Chars (Old_S) = Chars (New_S)))
2657 Error_Msg_N ("subprogram cannot rename itself", N);
2660 Set_Convention (New_S, Convention (Old_S));
2662 if Is_Abstract_Subprogram (Old_S) then
2663 if Present (Rename_Spec) then
2665 ("a renaming-as-body cannot rename an abstract subprogram",
2667 Set_Has_Completion (Rename_Spec);
2669 Set_Is_Abstract_Subprogram (New_S);
2673 Check_Library_Unit_Renaming (N, Old_S);
2675 -- Pathological case: procedure renames entry in the scope of its
2676 -- task. Entry is given by simple name, but body must be built for
2677 -- procedure. Of course if called it will deadlock.
2679 if Ekind (Old_S) = E_Entry then
2680 Set_Has_Completion (New_S, False);
2681 Set_Alias (New_S, Empty);
2685 Freeze_Before (N, Old_S);
2686 Set_Has_Delayed_Freeze (New_S, False);
2687 Freeze_Before (N, New_S);
2689 -- An abstract subprogram is only allowed as an actual in the case
2690 -- where the formal subprogram is also abstract.
2692 if (Ekind (Old_S) = E_Procedure or else Ekind (Old_S) = E_Function)
2693 and then Is_Abstract_Subprogram (Old_S)
2694 and then not Is_Abstract_Subprogram (Formal_Spec)
2697 ("abstract subprogram not allowed as generic actual", Nam);
2702 -- A common error is to assume that implicit operators for types are
2703 -- defined in Standard, or in the scope of a subtype. In those cases
2704 -- where the renamed entity is given with an expanded name, it is
2705 -- worth mentioning that operators for the type are not declared in
2706 -- the scope given by the prefix.
2708 if Nkind (Nam) = N_Expanded_Name
2709 and then Nkind (Selector_Name (Nam)) = N_Operator_Symbol
2710 and then Scope (Entity (Nam)) = Standard_Standard
2713 T : constant Entity_Id :=
2714 Base_Type (Etype (First_Formal (New_S)));
2716 Error_Msg_Node_2 := Prefix (Nam);
2718 ("operator for type& is not declared in&", Prefix (Nam), T);
2723 ("no visible subprogram matches the specification for&",
2727 if Present (Candidate_Renaming) then
2734 F1 := First_Formal (Candidate_Renaming);
2735 F2 := First_Formal (New_S);
2736 T1 := First_Subtype (Etype (F1));
2738 while Present (F1) and then Present (F2) loop
2743 if Present (F1) and then Present (Default_Value (F1)) then
2744 if Present (Next_Formal (F1)) then
2746 ("\missing specification for &" &
2747 " and other formals with defaults", Spec, F1);
2750 ("\missing specification for &", Spec, F1);
2754 if Nkind (Nam) = N_Operator_Symbol
2755 and then From_Default (N)
2757 Error_Msg_Node_2 := T1;
2759 ("default & on & is not directly visible",
2766 -- Ada 2005 AI 404: if the new subprogram is dispatching, verify that
2767 -- controlling access parameters are known non-null for the renamed
2768 -- subprogram. Test also applies to a subprogram instantiation that
2769 -- is dispatching. Test is skipped if some previous error was detected
2770 -- that set Old_S to Any_Id.
2772 if Ada_Version >= Ada_2005
2773 and then Old_S /= Any_Id
2774 and then not Is_Dispatching_Operation (Old_S)
2775 and then Is_Dispatching_Operation (New_S)
2782 Old_F := First_Formal (Old_S);
2783 New_F := First_Formal (New_S);
2784 while Present (Old_F) loop
2785 if Ekind (Etype (Old_F)) = E_Anonymous_Access_Type
2786 and then Is_Controlling_Formal (New_F)
2787 and then not Can_Never_Be_Null (Old_F)
2789 Error_Msg_N ("access parameter is controlling,", New_F);
2791 ("\corresponding parameter of& "
2792 & "must be explicitly null excluding", New_F, Old_S);
2795 Next_Formal (Old_F);
2796 Next_Formal (New_F);
2801 -- A useful warning, suggested by Ada Bug Finder (Ada-Europe 2005)
2802 -- is to warn if an operator is being renamed as a different operator.
2803 -- If the operator is predefined, examine the kind of the entity, not
2804 -- the abbreviated declaration in Standard.
2806 if Comes_From_Source (N)
2807 and then Present (Old_S)
2809 (Nkind (Old_S) = N_Defining_Operator_Symbol
2810 or else Ekind (Old_S) = E_Operator)
2811 and then Nkind (New_S) = N_Defining_Operator_Symbol
2812 and then Chars (Old_S) /= Chars (New_S)
2815 ("?& is being renamed as a different operator", N, Old_S);
2818 -- Check for renaming of obsolescent subprogram
2820 Check_Obsolescent_2005_Entity (Entity (Nam), Nam);
2822 -- Another warning or some utility: if the new subprogram as the same
2823 -- name as the old one, the old one is not hidden by an outer homograph,
2824 -- the new one is not a public symbol, and the old one is otherwise
2825 -- directly visible, the renaming is superfluous.
2827 if Chars (Old_S) = Chars (New_S)
2828 and then Comes_From_Source (N)
2829 and then Scope (Old_S) /= Standard_Standard
2830 and then Warn_On_Redundant_Constructs
2832 (Is_Immediately_Visible (Old_S)
2833 or else Is_Potentially_Use_Visible (Old_S))
2834 and then Is_Overloadable (Current_Scope)
2835 and then Chars (Current_Scope) /= Chars (Old_S)
2838 ("?redundant renaming, entity is directly visible", Name (N));
2841 Ada_Version := Save_AV;
2842 Ada_Version_Explicit := Save_AV_Exp;
2843 end Analyze_Subprogram_Renaming;
2845 -------------------------
2846 -- Analyze_Use_Package --
2847 -------------------------
2849 -- Resolve the package names in the use clause, and make all the visible
2850 -- entities defined in the package potentially use-visible. If the package
2851 -- is already in use from a previous use clause, its visible entities are
2852 -- already use-visible. In that case, mark the occurrence as a redundant
2853 -- use. If the package is an open scope, i.e. if the use clause occurs
2854 -- within the package itself, ignore it.
2856 procedure Analyze_Use_Package (N : Node_Id) is
2857 Pack_Name : Node_Id;
2860 -- Start of processing for Analyze_Use_Package
2863 Check_SPARK_Restriction ("use clause is not allowed", N);
2865 Set_Hidden_By_Use_Clause (N, No_Elist);
2867 -- Use clause not allowed in a spec of a predefined package declaration
2868 -- except that packages whose file name starts a-n are OK (these are
2869 -- children of Ada.Numerics, which are never loaded by Rtsfind).
2871 if Is_Predefined_File_Name (Unit_File_Name (Current_Sem_Unit))
2872 and then Name_Buffer (1 .. 3) /= "a-n"
2874 Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Declaration
2876 Error_Msg_N ("use clause not allowed in predefined spec", N);
2879 -- Chain clause to list of use clauses in current scope
2881 if Nkind (Parent (N)) /= N_Compilation_Unit then
2882 Chain_Use_Clause (N);
2885 -- Loop through package names to identify referenced packages
2887 Pack_Name := First (Names (N));
2888 while Present (Pack_Name) loop
2889 Analyze (Pack_Name);
2891 if Nkind (Parent (N)) = N_Compilation_Unit
2892 and then Nkind (Pack_Name) = N_Expanded_Name
2898 Pref := Prefix (Pack_Name);
2899 while Nkind (Pref) = N_Expanded_Name loop
2900 Pref := Prefix (Pref);
2903 if Entity (Pref) = Standard_Standard then
2905 ("predefined package Standard cannot appear"
2906 & " in a context clause", Pref);
2914 -- Loop through package names to mark all entities as potentially
2917 Pack_Name := First (Names (N));
2918 while Present (Pack_Name) loop
2919 if Is_Entity_Name (Pack_Name) then
2920 Pack := Entity (Pack_Name);
2922 if Ekind (Pack) /= E_Package
2923 and then Etype (Pack) /= Any_Type
2925 if Ekind (Pack) = E_Generic_Package then
2926 Error_Msg_N -- CODEFIX
2927 ("a generic package is not allowed in a use clause",
2930 Error_Msg_N ("& is not a usable package", Pack_Name);
2934 if Nkind (Parent (N)) = N_Compilation_Unit then
2935 Check_In_Previous_With_Clause (N, Pack_Name);
2938 if Applicable_Use (Pack_Name) then
2939 Use_One_Package (Pack, N);
2943 -- Report error because name denotes something other than a package
2946 Error_Msg_N ("& is not a package", Pack_Name);
2951 end Analyze_Use_Package;
2953 ----------------------
2954 -- Analyze_Use_Type --
2955 ----------------------
2957 procedure Analyze_Use_Type (N : Node_Id) is
2962 Set_Hidden_By_Use_Clause (N, No_Elist);
2964 -- Chain clause to list of use clauses in current scope
2966 if Nkind (Parent (N)) /= N_Compilation_Unit then
2967 Chain_Use_Clause (N);
2970 -- If the Used_Operations list is already initialized, the clause has
2971 -- been analyzed previously, and it is begin reinstalled, for example
2972 -- when the clause appears in a package spec and we are compiling the
2973 -- corresponding package body. In that case, make the entities on the
2974 -- existing list use_visible, and mark the corresponding types In_Use.
2976 if Present (Used_Operations (N)) then
2982 Mark := First (Subtype_Marks (N));
2983 while Present (Mark) loop
2984 Use_One_Type (Mark, Installed => True);
2988 Elmt := First_Elmt (Used_Operations (N));
2989 while Present (Elmt) loop
2990 Set_Is_Potentially_Use_Visible (Node (Elmt));
2998 -- Otherwise, create new list and attach to it the operations that
2999 -- are made use-visible by the clause.
3001 Set_Used_Operations (N, New_Elmt_List);
3002 Id := First (Subtype_Marks (N));
3003 while Present (Id) loop
3007 if E /= Any_Type then
3010 if Nkind (Parent (N)) = N_Compilation_Unit then
3011 if Nkind (Id) = N_Identifier then
3012 Error_Msg_N ("type is not directly visible", Id);
3014 elsif Is_Child_Unit (Scope (E))
3015 and then Scope (E) /= System_Aux_Id
3017 Check_In_Previous_With_Clause (N, Prefix (Id));
3022 -- If the use_type_clause appears in a compilation unit context,
3023 -- check whether it comes from a unit that may appear in a
3024 -- limited_with_clause, for a better error message.
3026 if Nkind (Parent (N)) = N_Compilation_Unit
3027 and then Nkind (Id) /= N_Identifier
3033 function Mentioned (Nam : Node_Id) return Boolean;
3034 -- Check whether the prefix of expanded name for the type
3035 -- appears in the prefix of some limited_with_clause.
3041 function Mentioned (Nam : Node_Id) return Boolean is
3043 return Nkind (Name (Item)) = N_Selected_Component
3045 Chars (Prefix (Name (Item))) = Chars (Nam);
3049 Pref := Prefix (Id);
3050 Item := First (Context_Items (Parent (N)));
3052 while Present (Item) and then Item /= N loop
3053 if Nkind (Item) = N_With_Clause
3054 and then Limited_Present (Item)
3055 and then Mentioned (Pref)
3058 (Get_Msg_Id, "premature usage of incomplete type");
3069 end Analyze_Use_Type;
3071 --------------------
3072 -- Applicable_Use --
3073 --------------------
3075 function Applicable_Use (Pack_Name : Node_Id) return Boolean is
3076 Pack : constant Entity_Id := Entity (Pack_Name);
3079 if In_Open_Scopes (Pack) then
3080 if Warn_On_Redundant_Constructs
3081 and then Pack = Current_Scope
3083 Error_Msg_NE -- CODEFIX
3084 ("& is already use-visible within itself?", Pack_Name, Pack);
3089 elsif In_Use (Pack) then
3090 Note_Redundant_Use (Pack_Name);
3093 elsif Present (Renamed_Object (Pack))
3094 and then In_Use (Renamed_Object (Pack))
3096 Note_Redundant_Use (Pack_Name);
3104 ------------------------
3105 -- Attribute_Renaming --
3106 ------------------------
3108 procedure Attribute_Renaming (N : Node_Id) is
3109 Loc : constant Source_Ptr := Sloc (N);
3110 Nam : constant Node_Id := Name (N);
3111 Spec : constant Node_Id := Specification (N);
3112 New_S : constant Entity_Id := Defining_Unit_Name (Spec);
3113 Aname : constant Name_Id := Attribute_Name (Nam);
3115 Form_Num : Nat := 0;
3116 Expr_List : List_Id := No_List;
3118 Attr_Node : Node_Id;
3119 Body_Node : Node_Id;
3120 Param_Spec : Node_Id;
3123 Generate_Definition (New_S);
3125 -- This procedure is called in the context of subprogram renaming, and
3126 -- thus the attribute must be one that is a subprogram. All of those
3127 -- have at least one formal parameter, with the singular exception of
3128 -- AST_Entry (which is a real oddity, it is odd that this can be renamed
3131 if not Is_Non_Empty_List (Parameter_Specifications (Spec)) then
3132 if Aname /= Name_AST_Entry then
3134 ("subprogram renaming an attribute must have formals", N);
3139 Param_Spec := First (Parameter_Specifications (Spec));
3140 while Present (Param_Spec) loop
3141 Form_Num := Form_Num + 1;
3143 if Nkind (Parameter_Type (Param_Spec)) /= N_Access_Definition then
3144 Find_Type (Parameter_Type (Param_Spec));
3146 -- The profile of the new entity denotes the base type (s) of
3147 -- the types given in the specification. For access parameters
3148 -- there are no subtypes involved.
3150 Rewrite (Parameter_Type (Param_Spec),
3152 (Base_Type (Entity (Parameter_Type (Param_Spec))), Loc));
3155 if No (Expr_List) then
3156 Expr_List := New_List;
3159 Append_To (Expr_List,
3160 Make_Identifier (Loc,
3161 Chars => Chars (Defining_Identifier (Param_Spec))));
3163 -- The expressions in the attribute reference are not freeze
3164 -- points. Neither is the attribute as a whole, see below.
3166 Set_Must_Not_Freeze (Last (Expr_List));
3171 -- Immediate error if too many formals. Other mismatches in number or
3172 -- types of parameters are detected when we analyze the body of the
3173 -- subprogram that we construct.
3175 if Form_Num > 2 then
3176 Error_Msg_N ("too many formals for attribute", N);
3178 -- Error if the attribute reference has expressions that look like
3179 -- formal parameters.
3181 elsif Present (Expressions (Nam)) then
3182 Error_Msg_N ("illegal expressions in attribute reference", Nam);
3185 Aname = Name_Compose or else
3186 Aname = Name_Exponent or else
3187 Aname = Name_Leading_Part or else
3188 Aname = Name_Pos or else
3189 Aname = Name_Round or else
3190 Aname = Name_Scaling or else
3193 if Nkind (N) = N_Subprogram_Renaming_Declaration
3194 and then Present (Corresponding_Formal_Spec (N))
3197 ("generic actual cannot be attribute involving universal type",
3201 ("attribute involving a universal type cannot be renamed",
3206 -- AST_Entry is an odd case. It doesn't really make much sense to allow
3207 -- it to be renamed, but that's the DEC rule, so we have to do it right.
3208 -- The point is that the AST_Entry call should be made now, and what the
3209 -- function will return is the returned value.
3211 -- Note that there is no Expr_List in this case anyway
3213 if Aname = Name_AST_Entry then
3215 Ent : constant Entity_Id := Make_Temporary (Loc, 'R', Nam);
3220 Make_Object_Declaration (Loc,
3221 Defining_Identifier => Ent,
3222 Object_Definition =>
3223 New_Occurrence_Of (RTE (RE_AST_Handler), Loc),
3225 Constant_Present => True);
3227 Set_Assignment_OK (Decl, True);
3228 Insert_Action (N, Decl);
3229 Attr_Node := Make_Identifier (Loc, Chars (Ent));
3232 -- For all other attributes, we rewrite the attribute node to have
3233 -- a list of expressions corresponding to the subprogram formals.
3234 -- A renaming declaration is not a freeze point, and the analysis of
3235 -- the attribute reference should not freeze the type of the prefix.
3239 Make_Attribute_Reference (Loc,
3240 Prefix => Prefix (Nam),
3241 Attribute_Name => Aname,
3242 Expressions => Expr_List);
3244 Set_Must_Not_Freeze (Attr_Node);
3245 Set_Must_Not_Freeze (Prefix (Nam));
3248 -- Case of renaming a function
3250 if Nkind (Spec) = N_Function_Specification then
3251 if Is_Procedure_Attribute_Name (Aname) then
3252 Error_Msg_N ("attribute can only be renamed as procedure", Nam);
3256 Find_Type (Result_Definition (Spec));
3257 Rewrite (Result_Definition (Spec),
3259 Base_Type (Entity (Result_Definition (Spec))), Loc));
3262 Make_Subprogram_Body (Loc,
3263 Specification => Spec,
3264 Declarations => New_List,
3265 Handled_Statement_Sequence =>
3266 Make_Handled_Sequence_Of_Statements (Loc,
3267 Statements => New_List (
3268 Make_Simple_Return_Statement (Loc,
3269 Expression => Attr_Node))));
3271 -- Case of renaming a procedure
3274 if not Is_Procedure_Attribute_Name (Aname) then
3275 Error_Msg_N ("attribute can only be renamed as function", Nam);
3280 Make_Subprogram_Body (Loc,
3281 Specification => Spec,
3282 Declarations => New_List,
3283 Handled_Statement_Sequence =>
3284 Make_Handled_Sequence_Of_Statements (Loc,
3285 Statements => New_List (Attr_Node)));
3288 -- In case of tagged types we add the body of the generated function to
3289 -- the freezing actions of the type (because in the general case such
3290 -- type is still not frozen). We exclude from this processing generic
3291 -- formal subprograms found in instantiations and AST_Entry renamings.
3293 -- We must exclude VM targets and restricted run-time libraries because
3294 -- entity AST_Handler is defined in package System.Aux_Dec which is not
3295 -- available in those platforms.
3297 if VM_Target = No_VM
3298 and then not Restricted_Profile
3299 and then not Present (Corresponding_Formal_Spec (N))
3300 and then Etype (Nam) /= RTE (RE_AST_Handler)
3303 P : constant Entity_Id := Prefix (Nam);
3308 if Is_Tagged_Type (Etype (P)) then
3309 Ensure_Freeze_Node (Etype (P));
3310 Append_Freeze_Action (Etype (P), Body_Node);
3312 Rewrite (N, Body_Node);
3314 Set_Etype (New_S, Base_Type (Etype (New_S)));
3318 -- Generic formal subprograms or AST_Handler renaming
3321 Rewrite (N, Body_Node);
3323 Set_Etype (New_S, Base_Type (Etype (New_S)));
3326 if Is_Compilation_Unit (New_S) then
3328 ("a library unit can only rename another library unit", N);
3331 -- We suppress elaboration warnings for the resulting entity, since
3332 -- clearly they are not needed, and more particularly, in the case
3333 -- of a generic formal subprogram, the resulting entity can appear
3334 -- after the instantiation itself, and thus look like a bogus case
3335 -- of access before elaboration.
3337 Set_Suppress_Elaboration_Warnings (New_S);
3339 end Attribute_Renaming;
3341 ----------------------
3342 -- Chain_Use_Clause --
3343 ----------------------
3345 procedure Chain_Use_Clause (N : Node_Id) is
3347 Level : Int := Scope_Stack.Last;
3350 if not Is_Compilation_Unit (Current_Scope)
3351 or else not Is_Child_Unit (Current_Scope)
3353 null; -- Common case
3355 elsif Defining_Entity (Parent (N)) = Current_Scope then
3356 null; -- Common case for compilation unit
3359 -- If declaration appears in some other scope, it must be in some
3360 -- parent unit when compiling a child.
3362 Pack := Defining_Entity (Parent (N));
3363 if not In_Open_Scopes (Pack) then
3364 null; -- default as well
3367 -- Find entry for parent unit in scope stack
3369 while Scope_Stack.Table (Level).Entity /= Pack loop
3375 Set_Next_Use_Clause (N,
3376 Scope_Stack.Table (Level).First_Use_Clause);
3377 Scope_Stack.Table (Level).First_Use_Clause := N;
3378 end Chain_Use_Clause;
3380 ---------------------------
3381 -- Check_Frozen_Renaming --
3382 ---------------------------
3384 procedure Check_Frozen_Renaming (N : Node_Id; Subp : Entity_Id) is
3390 and then not Has_Completion (Subp)
3394 (Parent (Declaration_Node (Subp)), Defining_Entity (N));
3396 if Is_Entity_Name (Name (N)) then
3397 Old_S := Entity (Name (N));
3399 if not Is_Frozen (Old_S)
3400 and then Operating_Mode /= Check_Semantics
3402 Append_Freeze_Action (Old_S, B_Node);
3404 Insert_After (N, B_Node);
3408 if Is_Intrinsic_Subprogram (Old_S)
3409 and then not In_Instance
3412 ("subprogram used in renaming_as_body cannot be intrinsic",
3417 Insert_After (N, B_Node);
3421 end Check_Frozen_Renaming;
3423 -------------------------------
3424 -- Set_Entity_Or_Discriminal --
3425 -------------------------------
3427 procedure Set_Entity_Or_Discriminal (N : Node_Id; E : Entity_Id) is
3431 -- If the entity is not a discriminant, or else expansion is disabled,
3432 -- simply set the entity.
3434 if not In_Spec_Expression
3435 or else Ekind (E) /= E_Discriminant
3436 or else Inside_A_Generic
3438 Set_Entity_With_Style_Check (N, E);
3440 -- The replacement of a discriminant by the corresponding discriminal
3441 -- is not done for a task discriminant that appears in a default
3442 -- expression of an entry parameter. See Exp_Ch2.Expand_Discriminant
3443 -- for details on their handling.
3445 elsif Is_Concurrent_Type (Scope (E)) then
3449 and then not Nkind_In (P, N_Parameter_Specification,
3450 N_Component_Declaration)
3456 and then Nkind (P) = N_Parameter_Specification
3461 Set_Entity (N, Discriminal (E));
3464 -- Otherwise, this is a discriminant in a context in which
3465 -- it is a reference to the corresponding parameter of the
3466 -- init proc for the enclosing type.
3469 Set_Entity (N, Discriminal (E));
3471 end Set_Entity_Or_Discriminal;
3473 -----------------------------------
3474 -- Check_In_Previous_With_Clause --
3475 -----------------------------------
3477 procedure Check_In_Previous_With_Clause
3481 Pack : constant Entity_Id := Entity (Original_Node (Nam));
3486 Item := First (Context_Items (Parent (N)));
3488 while Present (Item)
3491 if Nkind (Item) = N_With_Clause
3493 -- Protect the frontend against previous critical errors
3495 and then Nkind (Name (Item)) /= N_Selected_Component
3496 and then Entity (Name (Item)) = Pack
3500 -- Find root library unit in with_clause
3502 while Nkind (Par) = N_Expanded_Name loop
3503 Par := Prefix (Par);
3506 if Is_Child_Unit (Entity (Original_Node (Par))) then
3507 Error_Msg_NE ("& is not directly visible", Par, Entity (Par));
3516 -- On exit, package is not mentioned in a previous with_clause.
3517 -- Check if its prefix is.
3519 if Nkind (Nam) = N_Expanded_Name then
3520 Check_In_Previous_With_Clause (N, Prefix (Nam));
3522 elsif Pack /= Any_Id then
3523 Error_Msg_NE ("& is not visible", Nam, Pack);
3525 end Check_In_Previous_With_Clause;
3527 ---------------------------------
3528 -- Check_Library_Unit_Renaming --
3529 ---------------------------------
3531 procedure Check_Library_Unit_Renaming (N : Node_Id; Old_E : Entity_Id) is
3535 if Nkind (Parent (N)) /= N_Compilation_Unit then
3538 -- Check for library unit. Note that we used to check for the scope
3539 -- being Standard here, but that was wrong for Standard itself.
3541 elsif not Is_Compilation_Unit (Old_E)
3542 and then not Is_Child_Unit (Old_E)
3544 Error_Msg_N ("renamed unit must be a library unit", Name (N));
3546 -- Entities defined in Standard (operators and boolean literals) cannot
3547 -- be renamed as library units.
3549 elsif Scope (Old_E) = Standard_Standard
3550 and then Sloc (Old_E) = Standard_Location
3552 Error_Msg_N ("renamed unit must be a library unit", Name (N));
3554 elsif Present (Parent_Spec (N))
3555 and then Nkind (Unit (Parent_Spec (N))) = N_Generic_Package_Declaration
3556 and then not Is_Child_Unit (Old_E)
3559 ("renamed unit must be a child unit of generic parent", Name (N));
3561 elsif Nkind (N) in N_Generic_Renaming_Declaration
3562 and then Nkind (Name (N)) = N_Expanded_Name
3563 and then Is_Generic_Instance (Entity (Prefix (Name (N))))
3564 and then Is_Generic_Unit (Old_E)
3567 ("renamed generic unit must be a library unit", Name (N));
3569 elsif Is_Package_Or_Generic_Package (Old_E) then
3571 -- Inherit categorization flags
3573 New_E := Defining_Entity (N);
3574 Set_Is_Pure (New_E, Is_Pure (Old_E));
3575 Set_Is_Preelaborated (New_E, Is_Preelaborated (Old_E));
3576 Set_Is_Remote_Call_Interface (New_E,
3577 Is_Remote_Call_Interface (Old_E));
3578 Set_Is_Remote_Types (New_E, Is_Remote_Types (Old_E));
3579 Set_Is_Shared_Passive (New_E, Is_Shared_Passive (Old_E));
3581 end Check_Library_Unit_Renaming;
3587 procedure End_Scope is
3593 Id := First_Entity (Current_Scope);
3594 while Present (Id) loop
3595 -- An entity in the current scope is not necessarily the first one
3596 -- on its homonym chain. Find its predecessor if any,
3597 -- If it is an internal entity, it will not be in the visibility
3598 -- chain altogether, and there is nothing to unchain.
3600 if Id /= Current_Entity (Id) then
3601 Prev := Current_Entity (Id);
3602 while Present (Prev)
3603 and then Present (Homonym (Prev))
3604 and then Homonym (Prev) /= Id
3606 Prev := Homonym (Prev);
3609 -- Skip to end of loop if Id is not in the visibility chain
3611 if No (Prev) or else Homonym (Prev) /= Id then
3619 Set_Is_Immediately_Visible (Id, False);
3621 Outer := Homonym (Id);
3622 while Present (Outer) and then Scope (Outer) = Current_Scope loop
3623 Outer := Homonym (Outer);
3626 -- Reset homonym link of other entities, but do not modify link
3627 -- between entities in current scope, so that the back-end can have
3628 -- a proper count of local overloadings.
3631 Set_Name_Entity_Id (Chars (Id), Outer);
3633 elsif Scope (Prev) /= Scope (Id) then
3634 Set_Homonym (Prev, Outer);
3641 -- If the scope generated freeze actions, place them before the
3642 -- current declaration and analyze them. Type declarations and
3643 -- the bodies of initialization procedures can generate such nodes.
3644 -- We follow the parent chain until we reach a list node, which is
3645 -- the enclosing list of declarations. If the list appears within
3646 -- a protected definition, move freeze nodes outside the protected
3650 (Scope_Stack.Table (Scope_Stack.Last).Pending_Freeze_Actions)
3654 L : constant List_Id := Scope_Stack.Table
3655 (Scope_Stack.Last).Pending_Freeze_Actions;
3658 if Is_Itype (Current_Scope) then
3659 Decl := Associated_Node_For_Itype (Current_Scope);
3661 Decl := Parent (Current_Scope);
3666 while not (Is_List_Member (Decl))
3667 or else Nkind_In (Parent (Decl), N_Protected_Definition,
3670 Decl := Parent (Decl);
3673 Insert_List_Before_And_Analyze (Decl, L);
3682 ---------------------
3683 -- End_Use_Clauses --
3684 ---------------------
3686 procedure End_Use_Clauses (Clause : Node_Id) is
3690 -- Remove Use_Type clauses first, because they affect the
3691 -- visibility of operators in subsequent used packages.
3694 while Present (U) loop
3695 if Nkind (U) = N_Use_Type_Clause then
3699 Next_Use_Clause (U);
3703 while Present (U) loop
3704 if Nkind (U) = N_Use_Package_Clause then
3705 End_Use_Package (U);
3708 Next_Use_Clause (U);
3710 end End_Use_Clauses;
3712 ---------------------
3713 -- End_Use_Package --
3714 ---------------------
3716 procedure End_Use_Package (N : Node_Id) is
3717 Pack_Name : Node_Id;
3722 function Is_Primitive_Operator_In_Use
3724 F : Entity_Id) return Boolean;
3725 -- Check whether Op is a primitive operator of a use-visible type
3727 ----------------------------------
3728 -- Is_Primitive_Operator_In_Use --
3729 ----------------------------------
3731 function Is_Primitive_Operator_In_Use
3733 F : Entity_Id) return Boolean
3735 T : constant Entity_Id := Base_Type (Etype (F));
3737 return In_Use (T) and then Scope (T) = Scope (Op);
3738 end Is_Primitive_Operator_In_Use;
3740 -- Start of processing for End_Use_Package
3743 Pack_Name := First (Names (N));
3744 while Present (Pack_Name) loop
3746 -- Test that Pack_Name actually denotes a package before processing
3748 if Is_Entity_Name (Pack_Name)
3749 and then Ekind (Entity (Pack_Name)) = E_Package
3751 Pack := Entity (Pack_Name);
3753 if In_Open_Scopes (Pack) then
3756 elsif not Redundant_Use (Pack_Name) then
3757 Set_In_Use (Pack, False);
3758 Set_Current_Use_Clause (Pack, Empty);
3760 Id := First_Entity (Pack);
3761 while Present (Id) loop
3763 -- Preserve use-visibility of operators that are primitive
3764 -- operators of a type that is use-visible through an active
3767 if Nkind (Id) = N_Defining_Operator_Symbol
3769 (Is_Primitive_Operator_In_Use
3770 (Id, First_Formal (Id))
3772 (Present (Next_Formal (First_Formal (Id)))
3774 Is_Primitive_Operator_In_Use
3775 (Id, Next_Formal (First_Formal (Id)))))
3780 Set_Is_Potentially_Use_Visible (Id, False);
3783 if Is_Private_Type (Id)
3784 and then Present (Full_View (Id))
3786 Set_Is_Potentially_Use_Visible (Full_View (Id), False);
3792 if Present (Renamed_Object (Pack)) then
3793 Set_In_Use (Renamed_Object (Pack), False);
3794 Set_Current_Use_Clause (Renamed_Object (Pack), Empty);
3797 if Chars (Pack) = Name_System
3798 and then Scope (Pack) = Standard_Standard
3799 and then Present_System_Aux
3801 Id := First_Entity (System_Aux_Id);
3802 while Present (Id) loop
3803 Set_Is_Potentially_Use_Visible (Id, False);
3805 if Is_Private_Type (Id)
3806 and then Present (Full_View (Id))
3808 Set_Is_Potentially_Use_Visible (Full_View (Id), False);
3814 Set_In_Use (System_Aux_Id, False);
3818 Set_Redundant_Use (Pack_Name, False);
3825 if Present (Hidden_By_Use_Clause (N)) then
3826 Elmt := First_Elmt (Hidden_By_Use_Clause (N));
3827 while Present (Elmt) loop
3829 E : constant Entity_Id := Node (Elmt);
3832 -- Reset either Use_Visibility or Direct_Visibility, depending
3833 -- on how the entity was hidden by the use clause.
3835 if In_Use (Scope (E))
3836 and then Used_As_Generic_Actual (Scope (E))
3838 Set_Is_Potentially_Use_Visible (Node (Elmt));
3840 Set_Is_Immediately_Visible (Node (Elmt));
3847 Set_Hidden_By_Use_Clause (N, No_Elist);
3849 end End_Use_Package;
3855 procedure End_Use_Type (N : Node_Id) is
3860 -- Start of processing for End_Use_Type
3863 Id := First (Subtype_Marks (N));
3864 while Present (Id) loop
3866 -- A call to Rtsfind may occur while analyzing a use_type clause,
3867 -- in which case the type marks are not resolved yet, and there is
3868 -- nothing to remove.
3870 if not Is_Entity_Name (Id) or else No (Entity (Id)) then
3876 if T = Any_Type or else From_With_Type (T) then
3879 -- Note that the use_type clause may mention a subtype of the type
3880 -- whose primitive operations have been made visible. Here as
3881 -- elsewhere, it is the base type that matters for visibility.
3883 elsif In_Open_Scopes (Scope (Base_Type (T))) then
3886 elsif not Redundant_Use (Id) then
3887 Set_In_Use (T, False);
3888 Set_In_Use (Base_Type (T), False);
3889 Set_Current_Use_Clause (T, Empty);
3890 Set_Current_Use_Clause (Base_Type (T), Empty);
3897 if Is_Empty_Elmt_List (Used_Operations (N)) then
3901 Elmt := First_Elmt (Used_Operations (N));
3902 while Present (Elmt) loop
3903 Set_Is_Potentially_Use_Visible (Node (Elmt), False);
3909 ----------------------
3910 -- Find_Direct_Name --
3911 ----------------------
3913 procedure Find_Direct_Name (N : Node_Id) is
3918 Inst : Entity_Id := Empty;
3919 -- Enclosing instance, if any
3921 Homonyms : Entity_Id;
3922 -- Saves start of homonym chain
3924 Nvis_Entity : Boolean;
3925 -- Set True to indicate that there is at least one entity on the homonym
3926 -- chain which, while not visible, is visible enough from the user point
3927 -- of view to warrant an error message of "not visible" rather than
3930 Nvis_Is_Private_Subprg : Boolean := False;
3931 -- Ada 2005 (AI-262): Set True to indicate that a form of Beaujolais
3932 -- effect concerning library subprograms has been detected. Used to
3933 -- generate the precise error message.
3935 function From_Actual_Package (E : Entity_Id) return Boolean;
3936 -- Returns true if the entity is declared in a package that is
3937 -- an actual for a formal package of the current instance. Such an
3938 -- entity requires special handling because it may be use-visible
3939 -- but hides directly visible entities defined outside the instance.
3941 function Is_Actual_Parameter return Boolean;
3942 -- This function checks if the node N is an identifier that is an actual
3943 -- parameter of a procedure call. If so it returns True, otherwise it
3944 -- return False. The reason for this check is that at this stage we do
3945 -- not know what procedure is being called if the procedure might be
3946 -- overloaded, so it is premature to go setting referenced flags or
3947 -- making calls to Generate_Reference. We will wait till Resolve_Actuals
3948 -- for that processing
3950 function Known_But_Invisible (E : Entity_Id) return Boolean;
3951 -- This function determines whether the entity E (which is not
3952 -- visible) can reasonably be considered to be known to the writer
3953 -- of the reference. This is a heuristic test, used only for the
3954 -- purposes of figuring out whether we prefer to complain that an
3955 -- entity is undefined or invisible (and identify the declaration
3956 -- of the invisible entity in the latter case). The point here is
3957 -- that we don't want to complain that something is invisible and
3958 -- then point to something entirely mysterious to the writer.
3960 procedure Nvis_Messages;
3961 -- Called if there are no visible entries for N, but there is at least
3962 -- one non-directly visible, or hidden declaration. This procedure
3963 -- outputs an appropriate set of error messages.
3965 procedure Undefined (Nvis : Boolean);
3966 -- This function is called if the current node has no corresponding
3967 -- visible entity or entities. The value set in Msg indicates whether
3968 -- an error message was generated (multiple error messages for the
3969 -- same variable are generally suppressed, see body for details).
3970 -- Msg is True if an error message was generated, False if not. This
3971 -- value is used by the caller to determine whether or not to output
3972 -- additional messages where appropriate. The parameter is set False
3973 -- to get the message "X is undefined", and True to get the message
3974 -- "X is not visible".
3976 -------------------------
3977 -- From_Actual_Package --
3978 -------------------------
3980 function From_Actual_Package (E : Entity_Id) return Boolean is
3981 Scop : constant Entity_Id := Scope (E);
3985 if not In_Instance then
3988 Inst := Current_Scope;
3989 while Present (Inst)
3990 and then Ekind (Inst) /= E_Package
3991 and then not Is_Generic_Instance (Inst)
3993 Inst := Scope (Inst);
4000 Act := First_Entity (Inst);
4001 while Present (Act) loop
4002 if Ekind (Act) = E_Package then
4004 -- Check for end of actuals list
4006 if Renamed_Object (Act) = Inst then
4009 elsif Present (Associated_Formal_Package (Act))
4010 and then Renamed_Object (Act) = Scop
4012 -- Entity comes from (instance of) formal package
4027 end From_Actual_Package;
4029 -------------------------
4030 -- Is_Actual_Parameter --
4031 -------------------------
4033 function Is_Actual_Parameter return Boolean is
4036 Nkind (N) = N_Identifier
4038 (Nkind (Parent (N)) = N_Procedure_Call_Statement
4040 (Nkind (Parent (N)) = N_Parameter_Association
4041 and then N = Explicit_Actual_Parameter (Parent (N))
4042 and then Nkind (Parent (Parent (N))) =
4043 N_Procedure_Call_Statement));
4044 end Is_Actual_Parameter;
4046 -------------------------
4047 -- Known_But_Invisible --
4048 -------------------------
4050 function Known_But_Invisible (E : Entity_Id) return Boolean is
4051 Fname : File_Name_Type;
4054 -- Entities in Standard are always considered to be known
4056 if Sloc (E) <= Standard_Location then
4059 -- An entity that does not come from source is always considered
4060 -- to be unknown, since it is an artifact of code expansion.
4062 elsif not Comes_From_Source (E) then
4065 -- In gnat internal mode, we consider all entities known
4067 elsif GNAT_Mode then
4071 -- Here we have an entity that is not from package Standard, and
4072 -- which comes from Source. See if it comes from an internal file.
4074 Fname := Unit_File_Name (Get_Source_Unit (E));
4076 -- Case of from internal file
4078 if Is_Internal_File_Name (Fname) then
4080 -- Private part entities in internal files are never considered
4081 -- to be known to the writer of normal application code.
4083 if Is_Hidden (E) then
4087 -- Entities from System packages other than System and
4088 -- System.Storage_Elements are not considered to be known.
4089 -- System.Auxxxx files are also considered known to the user.
4091 -- Should refine this at some point to generally distinguish
4092 -- between known and unknown internal files ???
4094 Get_Name_String (Fname);
4099 Name_Buffer (1 .. 2) /= "s-"
4101 Name_Buffer (3 .. 8) = "stoele"
4103 Name_Buffer (3 .. 5) = "aux";
4105 -- If not an internal file, then entity is definitely known,
4106 -- even if it is in a private part (the message generated will
4107 -- note that it is in a private part)
4112 end Known_But_Invisible;
4118 procedure Nvis_Messages is
4119 Comp_Unit : Node_Id;
4121 Found : Boolean := False;
4122 Hidden : Boolean := False;
4126 -- Ada 2005 (AI-262): Generate a precise error concerning the
4127 -- Beaujolais effect that was previously detected
4129 if Nvis_Is_Private_Subprg then
4131 pragma Assert (Nkind (E2) = N_Defining_Identifier
4132 and then Ekind (E2) = E_Function
4133 and then Scope (E2) = Standard_Standard
4134 and then Has_Private_With (E2));
4136 -- Find the sloc corresponding to the private with'ed unit
4138 Comp_Unit := Cunit (Current_Sem_Unit);
4139 Error_Msg_Sloc := No_Location;
4141 Item := First (Context_Items (Comp_Unit));
4142 while Present (Item) loop
4143 if Nkind (Item) = N_With_Clause
4144 and then Private_Present (Item)
4145 and then Entity (Name (Item)) = E2
4147 Error_Msg_Sloc := Sloc (Item);
4154 pragma Assert (Error_Msg_Sloc /= No_Location);
4156 Error_Msg_N ("(Ada 2005): hidden by private with clause #", N);
4160 Undefined (Nvis => True);
4164 -- First loop does hidden declarations
4167 while Present (Ent) loop
4168 if Is_Potentially_Use_Visible (Ent) then
4170 Error_Msg_N -- CODEFIX
4171 ("multiple use clauses cause hiding!", N);
4175 Error_Msg_Sloc := Sloc (Ent);
4176 Error_Msg_N -- CODEFIX
4177 ("hidden declaration#!", N);
4180 Ent := Homonym (Ent);
4183 -- If we found hidden declarations, then that's enough, don't
4184 -- bother looking for non-visible declarations as well.
4190 -- Second loop does non-directly visible declarations
4193 while Present (Ent) loop
4194 if not Is_Potentially_Use_Visible (Ent) then
4196 -- Do not bother the user with unknown entities
4198 if not Known_But_Invisible (Ent) then
4202 Error_Msg_Sloc := Sloc (Ent);
4204 -- Output message noting that there is a non-visible
4205 -- declaration, distinguishing the private part case.
4207 if Is_Hidden (Ent) then
4208 Error_Msg_N ("non-visible (private) declaration#!", N);
4210 -- If the entity is declared in a generic package, it
4211 -- cannot be visible, so there is no point in adding it
4212 -- to the list of candidates if another homograph from a
4213 -- non-generic package has been seen.
4215 elsif Ekind (Scope (Ent)) = E_Generic_Package
4221 Error_Msg_N -- CODEFIX
4222 ("non-visible declaration#!", N);
4224 if Ekind (Scope (Ent)) /= E_Generic_Package then
4228 if Is_Compilation_Unit (Ent)
4230 Nkind (Parent (Parent (N))) = N_Use_Package_Clause
4232 Error_Msg_Qual_Level := 99;
4233 Error_Msg_NE -- CODEFIX
4234 ("\\missing `WITH &;`", N, Ent);
4235 Error_Msg_Qual_Level := 0;
4238 if Ekind (Ent) = E_Discriminant
4239 and then Present (Corresponding_Discriminant (Ent))
4240 and then Scope (Corresponding_Discriminant (Ent)) =
4244 ("inherited discriminant not allowed here" &
4245 " (RM 3.8 (12), 3.8.1 (6))!", N);
4249 -- Set entity and its containing package as referenced. We
4250 -- can't be sure of this, but this seems a better choice
4251 -- to avoid unused entity messages.
4253 if Comes_From_Source (Ent) then
4254 Set_Referenced (Ent);
4255 Set_Referenced (Cunit_Entity (Get_Source_Unit (Ent)));
4260 Ent := Homonym (Ent);
4269 procedure Undefined (Nvis : Boolean) is
4270 Emsg : Error_Msg_Id;
4273 -- We should never find an undefined internal name. If we do, then
4274 -- see if we have previous errors. If so, ignore on the grounds that
4275 -- it is probably a cascaded message (e.g. a block label from a badly
4276 -- formed block). If no previous errors, then we have a real internal
4277 -- error of some kind so raise an exception.
4279 if Is_Internal_Name (Chars (N)) then
4280 if Total_Errors_Detected /= 0 then
4283 raise Program_Error;
4287 -- A very specialized error check, if the undefined variable is
4288 -- a case tag, and the case type is an enumeration type, check
4289 -- for a possible misspelling, and if so, modify the identifier
4291 -- Named aggregate should also be handled similarly ???
4293 if Nkind (N) = N_Identifier
4294 and then Nkind (Parent (N)) = N_Case_Statement_Alternative
4297 Case_Stm : constant Node_Id := Parent (Parent (N));
4298 Case_Typ : constant Entity_Id := Etype (Expression (Case_Stm));
4303 if Is_Enumeration_Type (Case_Typ)
4304 and then not Is_Standard_Character_Type (Case_Typ)
4306 Lit := First_Literal (Case_Typ);
4307 Get_Name_String (Chars (Lit));
4309 if Chars (Lit) /= Chars (N)
4310 and then Is_Bad_Spelling_Of (Chars (N), Chars (Lit)) then
4311 Error_Msg_Node_2 := Lit;
4312 Error_Msg_N -- CODEFIX
4313 ("& is undefined, assume misspelling of &", N);
4314 Rewrite (N, New_Occurrence_Of (Lit, Sloc (N)));
4318 Lit := Next_Literal (Lit);
4323 -- Normal processing
4325 Set_Entity (N, Any_Id);
4326 Set_Etype (N, Any_Type);
4328 -- We use the table Urefs to keep track of entities for which we
4329 -- have issued errors for undefined references. Multiple errors
4330 -- for a single name are normally suppressed, however we modify
4331 -- the error message to alert the programmer to this effect.
4333 for J in Urefs.First .. Urefs.Last loop
4334 if Chars (N) = Chars (Urefs.Table (J).Node) then
4335 if Urefs.Table (J).Err /= No_Error_Msg
4336 and then Sloc (N) /= Urefs.Table (J).Loc
4338 Error_Msg_Node_1 := Urefs.Table (J).Node;
4340 if Urefs.Table (J).Nvis then
4341 Change_Error_Text (Urefs.Table (J).Err,
4342 "& is not visible (more references follow)");
4344 Change_Error_Text (Urefs.Table (J).Err,
4345 "& is undefined (more references follow)");
4348 Urefs.Table (J).Err := No_Error_Msg;
4351 -- Although we will set Msg False, and thus suppress the
4352 -- message, we also set Error_Posted True, to avoid any
4353 -- cascaded messages resulting from the undefined reference.
4356 Set_Error_Posted (N, True);
4361 -- If entry not found, this is first undefined occurrence
4364 Error_Msg_N ("& is not visible!", N);
4368 Error_Msg_N ("& is undefined!", N);
4371 -- A very bizarre special check, if the undefined identifier
4372 -- is put or put_line, then add a special error message (since
4373 -- this is a very common error for beginners to make).
4375 if Chars (N) = Name_Put or else Chars (N) = Name_Put_Line then
4376 Error_Msg_N -- CODEFIX
4377 ("\\possible missing `WITH Ada.Text_'I'O; " &
4378 "USE Ada.Text_'I'O`!", N);
4380 -- Another special check if N is the prefix of a selected
4381 -- component which is a known unit, add message complaining
4382 -- about missing with for this unit.
4384 elsif Nkind (Parent (N)) = N_Selected_Component
4385 and then N = Prefix (Parent (N))
4386 and then Is_Known_Unit (Parent (N))
4388 Error_Msg_Node_2 := Selector_Name (Parent (N));
4389 Error_Msg_N -- CODEFIX
4390 ("\\missing `WITH &.&;`", Prefix (Parent (N)));
4393 -- Now check for possible misspellings
4397 Ematch : Entity_Id := Empty;
4399 Last_Name_Id : constant Name_Id :=
4400 Name_Id (Nat (First_Name_Id) +
4401 Name_Entries_Count - 1);
4404 for Nam in First_Name_Id .. Last_Name_Id loop
4405 E := Get_Name_Entity_Id (Nam);
4408 and then (Is_Immediately_Visible (E)
4410 Is_Potentially_Use_Visible (E))
4412 if Is_Bad_Spelling_Of (Chars (N), Nam) then
4419 if Present (Ematch) then
4420 Error_Msg_NE -- CODEFIX
4421 ("\possible misspelling of&", N, Ematch);
4426 -- Make entry in undefined references table unless the full errors
4427 -- switch is set, in which case by refraining from generating the
4428 -- table entry, we guarantee that we get an error message for every
4429 -- undefined reference.
4431 if not All_Errors_Mode then
4442 -- Start of processing for Find_Direct_Name
4445 -- If the entity pointer is already set, this is an internal node, or
4446 -- a node that is analyzed more than once, after a tree modification.
4447 -- In such a case there is no resolution to perform, just set the type.
4449 if Present (Entity (N)) then
4450 if Is_Type (Entity (N)) then
4451 Set_Etype (N, Entity (N));
4455 Entyp : constant Entity_Id := Etype (Entity (N));
4458 -- One special case here. If the Etype field is already set,
4459 -- and references the packed array type corresponding to the
4460 -- etype of the referenced entity, then leave it alone. This
4461 -- happens for trees generated from Exp_Pakd, where expressions
4462 -- can be deliberately "mis-typed" to the packed array type.
4464 if Is_Array_Type (Entyp)
4465 and then Is_Packed (Entyp)
4466 and then Present (Etype (N))
4467 and then Etype (N) = Packed_Array_Type (Entyp)
4471 -- If not that special case, then just reset the Etype
4474 Set_Etype (N, Etype (Entity (N)));
4482 -- Here if Entity pointer was not set, we need full visibility analysis
4483 -- First we generate debugging output if the debug E flag is set.
4485 if Debug_Flag_E then
4486 Write_Str ("Looking for ");
4487 Write_Name (Chars (N));
4491 Homonyms := Current_Entity (N);
4492 Nvis_Entity := False;
4495 while Present (E) loop
4497 -- If entity is immediately visible or potentially use visible, then
4498 -- process the entity and we are done.
4500 if Is_Immediately_Visible (E) then
4501 goto Immediately_Visible_Entity;
4503 elsif Is_Potentially_Use_Visible (E) then
4504 goto Potentially_Use_Visible_Entity;
4506 -- Note if a known but invisible entity encountered
4508 elsif Known_But_Invisible (E) then
4509 Nvis_Entity := True;
4512 -- Move to next entity in chain and continue search
4517 -- If no entries on homonym chain that were potentially visible,
4518 -- and no entities reasonably considered as non-visible, then
4519 -- we have a plain undefined reference, with no additional
4520 -- explanation required!
4522 if not Nvis_Entity then
4523 Undefined (Nvis => False);
4525 -- Otherwise there is at least one entry on the homonym chain that
4526 -- is reasonably considered as being known and non-visible.
4534 -- Processing for a potentially use visible entry found. We must search
4535 -- the rest of the homonym chain for two reasons. First, if there is a
4536 -- directly visible entry, then none of the potentially use-visible
4537 -- entities are directly visible (RM 8.4(10)). Second, we need to check
4538 -- for the case of multiple potentially use-visible entries hiding one
4539 -- another and as a result being non-directly visible (RM 8.4(11)).
4541 <<Potentially_Use_Visible_Entity>> declare
4542 Only_One_Visible : Boolean := True;
4543 All_Overloadable : Boolean := Is_Overloadable (E);
4547 while Present (E2) loop
4548 if Is_Immediately_Visible (E2) then
4550 -- If the use-visible entity comes from the actual for a
4551 -- formal package, it hides a directly visible entity from
4552 -- outside the instance.
4554 if From_Actual_Package (E)
4555 and then Scope_Depth (E2) < Scope_Depth (Inst)
4560 goto Immediately_Visible_Entity;
4563 elsif Is_Potentially_Use_Visible (E2) then
4564 Only_One_Visible := False;
4565 All_Overloadable := All_Overloadable and Is_Overloadable (E2);
4567 -- Ada 2005 (AI-262): Protect against a form of Beaujolais effect
4568 -- that can occur in private_with clauses. Example:
4571 -- private with B; package A is
4572 -- package C is function B return Integer;
4574 -- V1 : Integer := B;
4575 -- private function B return Integer;
4576 -- V2 : Integer := B;
4579 -- V1 resolves to A.B, but V2 resolves to library unit B
4581 elsif Ekind (E2) = E_Function
4582 and then Scope (E2) = Standard_Standard
4583 and then Has_Private_With (E2)
4585 Only_One_Visible := False;
4586 All_Overloadable := False;
4587 Nvis_Is_Private_Subprg := True;
4594 -- On falling through this loop, we have checked that there are no
4595 -- immediately visible entities. Only_One_Visible is set if exactly
4596 -- one potentially use visible entity exists. All_Overloadable is
4597 -- set if all the potentially use visible entities are overloadable.
4598 -- The condition for legality is that either there is one potentially
4599 -- use visible entity, or if there is more than one, then all of them
4600 -- are overloadable.
4602 if Only_One_Visible or All_Overloadable then
4605 -- If there is more than one potentially use-visible entity and at
4606 -- least one of them non-overloadable, we have an error (RM 8.4(11).
4607 -- Note that E points to the first such entity on the homonym list.
4608 -- Special case: if one of the entities is declared in an actual
4609 -- package, it was visible in the generic, and takes precedence over
4610 -- other entities that are potentially use-visible. Same if it is
4611 -- declared in a local instantiation of the current instance.
4616 -- Find current instance
4618 Inst := Current_Scope;
4619 while Present (Inst)
4620 and then Inst /= Standard_Standard
4622 if Is_Generic_Instance (Inst) then
4626 Inst := Scope (Inst);
4630 while Present (E2) loop
4631 if From_Actual_Package (E2)
4633 (Is_Generic_Instance (Scope (E2))
4634 and then Scope_Depth (Scope (E2)) > Scope_Depth (Inst))
4647 Is_Predefined_File_Name (Unit_File_Name (Current_Sem_Unit))
4649 -- A use-clause in the body of a system file creates conflict
4650 -- with some entity in a user scope, while rtsfind is active.
4651 -- Keep only the entity coming from another predefined unit.
4654 while Present (E2) loop
4655 if Is_Predefined_File_Name
4656 (Unit_File_Name (Get_Source_Unit (Sloc (E2))))
4665 -- Entity must exist because predefined unit is correct
4667 raise Program_Error;
4676 -- Come here with E set to the first immediately visible entity on
4677 -- the homonym chain. This is the one we want unless there is another
4678 -- immediately visible entity further on in the chain for an inner
4679 -- scope (RM 8.3(8)).
4681 <<Immediately_Visible_Entity>> declare
4686 -- Find scope level of initial entity. When compiling through
4687 -- Rtsfind, the previous context is not completely invisible, and
4688 -- an outer entity may appear on the chain, whose scope is below
4689 -- the entry for Standard that delimits the current scope stack.
4690 -- Indicate that the level for this spurious entry is outside of
4691 -- the current scope stack.
4693 Level := Scope_Stack.Last;
4695 Scop := Scope_Stack.Table (Level).Entity;
4696 exit when Scop = Scope (E);
4698 exit when Scop = Standard_Standard;
4701 -- Now search remainder of homonym chain for more inner entry
4702 -- If the entity is Standard itself, it has no scope, and we
4703 -- compare it with the stack entry directly.
4706 while Present (E2) loop
4707 if Is_Immediately_Visible (E2) then
4709 -- If a generic package contains a local declaration that
4710 -- has the same name as the generic, there may be a visibility
4711 -- conflict in an instance, where the local declaration must
4712 -- also hide the name of the corresponding package renaming.
4713 -- We check explicitly for a package declared by a renaming,
4714 -- whose renamed entity is an instance that is on the scope
4715 -- stack, and that contains a homonym in the same scope. Once
4716 -- we have found it, we know that the package renaming is not
4717 -- immediately visible, and that the identifier denotes the
4718 -- other entity (and its homonyms if overloaded).
4720 if Scope (E) = Scope (E2)
4721 and then Ekind (E) = E_Package
4722 and then Present (Renamed_Object (E))
4723 and then Is_Generic_Instance (Renamed_Object (E))
4724 and then In_Open_Scopes (Renamed_Object (E))
4725 and then Comes_From_Source (N)
4727 Set_Is_Immediately_Visible (E, False);
4731 for J in Level + 1 .. Scope_Stack.Last loop
4732 if Scope_Stack.Table (J).Entity = Scope (E2)
4733 or else Scope_Stack.Table (J).Entity = E2
4746 -- At the end of that loop, E is the innermost immediately
4747 -- visible entity, so we are all set.
4750 -- Come here with entity found, and stored in E
4754 -- Check violation of No_Wide_Characters restriction
4756 Check_Wide_Character_Restriction (E, N);
4758 -- When distribution features are available (Get_PCS_Name /=
4759 -- Name_No_DSA), a remote access-to-subprogram type is converted
4760 -- into a record type holding whatever information is needed to
4761 -- perform a remote call on an RCI subprogram. In that case we
4762 -- rewrite any occurrence of the RAS type into the equivalent record
4763 -- type here. 'Access attribute references and RAS dereferences are
4764 -- then implemented using specific TSSs. However when distribution is
4765 -- not available (case of Get_PCS_Name = Name_No_DSA), we bypass the
4766 -- generation of these TSSs, and we must keep the RAS type in its
4767 -- original access-to-subprogram form (since all calls through a
4768 -- value of such type will be local anyway in the absence of a PCS).
4770 if Comes_From_Source (N)
4771 and then Is_Remote_Access_To_Subprogram_Type (E)
4772 and then Expander_Active
4773 and then Get_PCS_Name /= Name_No_DSA
4776 New_Occurrence_Of (Equivalent_Type (E), Sloc (N)));
4780 -- Set the entity. Note that the reason we call Set_Entity for the
4781 -- overloadable case, as opposed to Set_Entity_With_Style_Check is
4782 -- that in the overloaded case, the initial call can set the wrong
4783 -- homonym. The call that sets the right homonym is in Sem_Res and
4784 -- that call does use Set_Entity_With_Style_Check, so we don't miss
4787 if Is_Overloadable (E) then
4790 Set_Entity_With_Style_Check (N, E);
4796 Set_Etype (N, Get_Full_View (Etype (E)));
4799 if Debug_Flag_E then
4800 Write_Str (" found ");
4801 Write_Entity_Info (E, " ");
4804 -- If the Ekind of the entity is Void, it means that all homonyms
4805 -- are hidden from all visibility (RM 8.3(5,14-20)). However, this
4806 -- test is skipped if the current scope is a record and the name is
4807 -- a pragma argument expression (case of Atomic and Volatile pragmas
4808 -- and possibly other similar pragmas added later, which are allowed
4809 -- to reference components in the current record).
4811 if Ekind (E) = E_Void
4813 (not Is_Record_Type (Current_Scope)
4814 or else Nkind (Parent (N)) /= N_Pragma_Argument_Association)
4816 Premature_Usage (N);
4818 -- If the entity is overloadable, collect all interpretations of the
4819 -- name for subsequent overload resolution. We optimize a bit here to
4820 -- do this only if we have an overloadable entity that is not on its
4821 -- own on the homonym chain.
4823 elsif Is_Overloadable (E)
4824 and then (Present (Homonym (E)) or else Current_Entity (N) /= E)
4826 Collect_Interps (N);
4828 -- If no homonyms were visible, the entity is unambiguous
4830 if not Is_Overloaded (N) then
4831 if not Is_Actual_Parameter then
4832 Generate_Reference (E, N);
4836 -- Case of non-overloadable entity, set the entity providing that
4837 -- we do not have the case of a discriminant reference within a
4838 -- default expression. Such references are replaced with the
4839 -- corresponding discriminal, which is the formal corresponding to
4840 -- to the discriminant in the initialization procedure.
4843 -- Entity is unambiguous, indicate that it is referenced here
4845 -- For a renaming of an object, always generate simple reference,
4846 -- we don't try to keep track of assignments in this case.
4848 if Is_Object (E) and then Present (Renamed_Object (E)) then
4849 Generate_Reference (E, N);
4851 -- If the renamed entity is a private protected component,
4852 -- reference the original component as well. This needs to be
4853 -- done because the private renamings are installed before any
4854 -- analysis has occurred. Reference to a private component will
4855 -- resolve to the renaming and the original component will be
4856 -- left unreferenced, hence the following.
4858 if Is_Prival (E) then
4859 Generate_Reference (Prival_Link (E), N);
4862 -- One odd case is that we do not want to set the Referenced flag
4863 -- if the entity is a label, and the identifier is the label in
4864 -- the source, since this is not a reference from the point of
4865 -- view of the user.
4867 elsif Nkind (Parent (N)) = N_Label then
4869 R : constant Boolean := Referenced (E);
4872 -- Generate reference unless this is an actual parameter
4873 -- (see comment below)
4875 if Is_Actual_Parameter then
4876 Generate_Reference (E, N);
4877 Set_Referenced (E, R);
4881 -- Normal case, not a label: generate reference
4883 -- ??? It is too early to generate a reference here even if the
4884 -- entity is unambiguous, because the tree is not sufficiently
4885 -- typed at this point for Generate_Reference to determine
4886 -- whether this reference modifies the denoted object (because
4887 -- implicit dereferences cannot be identified prior to full type
4890 -- The Is_Actual_Parameter routine takes care of one of these
4891 -- cases but there are others probably ???
4893 -- If the entity is the LHS of an assignment, and is a variable
4894 -- (rather than a package prefix), we can mark it as a
4895 -- modification right away, to avoid duplicate references.
4898 if not Is_Actual_Parameter then
4900 and then Ekind (E) /= E_Package
4901 and then Ekind (E) /= E_Generic_Package
4903 Generate_Reference (E, N, 'm');
4905 Generate_Reference (E, N);
4909 Check_Nested_Access (E);
4912 Set_Entity_Or_Discriminal (N, E);
4914 if Ada_Version >= Ada_2012
4916 (Nkind (Parent (N)) in N_Subexpr
4917 or else Nkind (Parent (N)) = N_Object_Declaration)
4919 Check_Implicit_Dereference (N, Etype (E));
4923 end Find_Direct_Name;
4925 ------------------------
4926 -- Find_Expanded_Name --
4927 ------------------------
4929 -- This routine searches the homonym chain of the entity until it finds
4930 -- an entity declared in the scope denoted by the prefix. If the entity
4931 -- is private, it may nevertheless be immediately visible, if we are in
4932 -- the scope of its declaration.
4934 procedure Find_Expanded_Name (N : Node_Id) is
4935 Selector : constant Node_Id := Selector_Name (N);
4936 Candidate : Entity_Id := Empty;
4942 P_Name := Entity (Prefix (N));
4945 -- If the prefix is a renamed package, look for the entity in the
4946 -- original package.
4948 if Ekind (P_Name) = E_Package
4949 and then Present (Renamed_Object (P_Name))
4951 P_Name := Renamed_Object (P_Name);
4953 -- Rewrite node with entity field pointing to renamed object
4955 Rewrite (Prefix (N), New_Copy (Prefix (N)));
4956 Set_Entity (Prefix (N), P_Name);
4958 -- If the prefix is an object of a concurrent type, look for
4959 -- the entity in the associated task or protected type.
4961 elsif Is_Concurrent_Type (Etype (P_Name)) then
4962 P_Name := Etype (P_Name);
4965 Id := Current_Entity (Selector);
4968 Is_New_Candidate : Boolean;
4971 while Present (Id) loop
4972 if Scope (Id) = P_Name then
4974 Is_New_Candidate := True;
4976 -- Ada 2005 (AI-217): Handle shadow entities associated with types
4977 -- declared in limited-withed nested packages. We don't need to
4978 -- handle E_Incomplete_Subtype entities because the entities in
4979 -- the limited view are always E_Incomplete_Type entities (see
4980 -- Build_Limited_Views). Regarding the expression used to evaluate
4981 -- the scope, it is important to note that the limited view also
4982 -- has shadow entities associated nested packages. For this reason
4983 -- the correct scope of the entity is the scope of the real entity
4984 -- The non-limited view may itself be incomplete, in which case
4985 -- get the full view if available.
4987 elsif From_With_Type (Id)
4988 and then Is_Type (Id)
4989 and then Ekind (Id) = E_Incomplete_Type
4990 and then Present (Non_Limited_View (Id))
4991 and then Scope (Non_Limited_View (Id)) = P_Name
4993 Candidate := Get_Full_View (Non_Limited_View (Id));
4994 Is_New_Candidate := True;
4997 Is_New_Candidate := False;
5000 if Is_New_Candidate then
5001 if Is_Child_Unit (Id) then
5002 exit when Is_Visible_Child_Unit (Id)
5003 or else Is_Immediately_Visible (Id);
5006 exit when not Is_Hidden (Id)
5007 or else Is_Immediately_Visible (Id);
5016 and then (Ekind (P_Name) = E_Procedure
5018 Ekind (P_Name) = E_Function)
5019 and then Is_Generic_Instance (P_Name)
5021 -- Expanded name denotes entity in (instance of) generic subprogram.
5022 -- The entity may be in the subprogram instance, or may denote one of
5023 -- the formals, which is declared in the enclosing wrapper package.
5025 P_Name := Scope (P_Name);
5027 Id := Current_Entity (Selector);
5028 while Present (Id) loop
5029 exit when Scope (Id) = P_Name;
5034 if No (Id) or else Chars (Id) /= Chars (Selector) then
5035 Set_Etype (N, Any_Type);
5037 -- If we are looking for an entity defined in System, try to find it
5038 -- in the child package that may have been provided as an extension
5039 -- to System. The Extend_System pragma will have supplied the name of
5040 -- the extension, which may have to be loaded.
5042 if Chars (P_Name) = Name_System
5043 and then Scope (P_Name) = Standard_Standard
5044 and then Present (System_Extend_Unit)
5045 and then Present_System_Aux (N)
5047 Set_Entity (Prefix (N), System_Aux_Id);
5048 Find_Expanded_Name (N);
5051 elsif Nkind (Selector) = N_Operator_Symbol
5052 and then Has_Implicit_Operator (N)
5054 -- There is an implicit instance of the predefined operator in
5055 -- the given scope. The operator entity is defined in Standard.
5056 -- Has_Implicit_Operator makes the node into an Expanded_Name.
5060 elsif Nkind (Selector) = N_Character_Literal
5061 and then Has_Implicit_Character_Literal (N)
5063 -- If there is no literal defined in the scope denoted by the
5064 -- prefix, the literal may belong to (a type derived from)
5065 -- Standard_Character, for which we have no explicit literals.
5070 -- If the prefix is a single concurrent object, use its name in
5071 -- the error message, rather than that of the anonymous type.
5073 if Is_Concurrent_Type (P_Name)
5074 and then Is_Internal_Name (Chars (P_Name))
5076 Error_Msg_Node_2 := Entity (Prefix (N));
5078 Error_Msg_Node_2 := P_Name;
5081 if P_Name = System_Aux_Id then
5082 P_Name := Scope (P_Name);
5083 Set_Entity (Prefix (N), P_Name);
5086 if Present (Candidate) then
5088 -- If we know that the unit is a child unit we can give a more
5089 -- accurate error message.
5091 if Is_Child_Unit (Candidate) then
5093 -- If the candidate is a private child unit and we are in
5094 -- the visible part of a public unit, specialize the error
5095 -- message. There might be a private with_clause for it,
5096 -- but it is not currently active.
5098 if Is_Private_Descendant (Candidate)
5099 and then Ekind (Current_Scope) = E_Package
5100 and then not In_Private_Part (Current_Scope)
5101 and then not Is_Private_Descendant (Current_Scope)
5103 Error_Msg_N ("private child unit& is not visible here",
5106 -- Normal case where we have a missing with for a child unit
5109 Error_Msg_Qual_Level := 99;
5110 Error_Msg_NE -- CODEFIX
5111 ("missing `WITH &;`", Selector, Candidate);
5112 Error_Msg_Qual_Level := 0;
5115 -- Here we don't know that this is a child unit
5118 Error_Msg_NE ("& is not a visible entity of&", N, Selector);
5122 -- Within the instantiation of a child unit, the prefix may
5123 -- denote the parent instance, but the selector has the name
5124 -- of the original child. Find whether we are within the
5125 -- corresponding instance, and get the proper entity, which
5126 -- can only be an enclosing scope.
5129 and then In_Open_Scopes (P_Name)
5130 and then Is_Generic_Instance (P_Name)
5133 S : Entity_Id := Current_Scope;
5137 for J in reverse 0 .. Scope_Stack.Last loop
5138 S := Scope_Stack.Table (J).Entity;
5140 exit when S = Standard_Standard;
5142 if Ekind_In (S, E_Function,
5146 P := Generic_Parent (Specification
5147 (Unit_Declaration_Node (S)));
5150 and then Chars (Scope (P)) = Chars (O_Name)
5151 and then Chars (P) = Chars (Selector)
5162 -- If this is a selection from Ada, System or Interfaces, then
5163 -- we assume a missing with for the corresponding package.
5165 if Is_Known_Unit (N) then
5166 if not Error_Posted (N) then
5167 Error_Msg_Node_2 := Selector;
5168 Error_Msg_N -- CODEFIX
5169 ("missing `WITH &.&;`", Prefix (N));
5172 -- If this is a selection from a dummy package, then suppress
5173 -- the error message, of course the entity is missing if the
5174 -- package is missing!
5176 elsif Sloc (Error_Msg_Node_2) = No_Location then
5179 -- Here we have the case of an undefined component
5183 -- The prefix may hide a homonym in the context that
5184 -- declares the desired entity. This error can use a
5185 -- specialized message.
5187 if In_Open_Scopes (P_Name)
5188 and then Present (Homonym (P_Name))
5189 and then Is_Compilation_Unit (Homonym (P_Name))
5191 (Is_Immediately_Visible (Homonym (P_Name))
5192 or else Is_Visible_Child_Unit (Homonym (P_Name)))
5195 H : constant Entity_Id := Homonym (P_Name);
5198 Id := First_Entity (H);
5199 while Present (Id) loop
5200 if Chars (Id) = Chars (Selector) then
5201 Error_Msg_Qual_Level := 99;
5202 Error_Msg_Name_1 := Chars (Selector);
5204 ("% not declared in&", N, P_Name);
5206 ("\use fully qualified name starting with"
5207 & " Standard to make& visible", N, H);
5208 Error_Msg_Qual_Level := 0;
5215 -- If not found, standard error message
5217 Error_Msg_NE ("& not declared in&", N, Selector);
5223 Error_Msg_NE ("& not declared in&", N, Selector);
5226 -- Check for misspelling of some entity in prefix
5228 Id := First_Entity (P_Name);
5229 while Present (Id) loop
5230 if Is_Bad_Spelling_Of (Chars (Id), Chars (Selector))
5231 and then not Is_Internal_Name (Chars (Id))
5233 Error_Msg_NE -- CODEFIX
5234 ("possible misspelling of&", Selector, Id);
5241 -- Specialize the message if this may be an instantiation
5242 -- of a child unit that was not mentioned in the context.
5244 if Nkind (Parent (N)) = N_Package_Instantiation
5245 and then Is_Generic_Instance (Entity (Prefix (N)))
5246 and then Is_Compilation_Unit
5247 (Generic_Parent (Parent (Entity (Prefix (N)))))
5249 Error_Msg_Node_2 := Selector;
5250 Error_Msg_N -- CODEFIX
5251 ("\missing `WITH &.&;`", Prefix (N));
5261 if Comes_From_Source (N)
5262 and then Is_Remote_Access_To_Subprogram_Type (Id)
5263 and then Present (Equivalent_Type (Id))
5265 -- If we are not actually generating distribution code (i.e. the
5266 -- current PCS is the dummy non-distributed version), then the
5267 -- Equivalent_Type will be missing, and Id should be treated as
5268 -- a regular access-to-subprogram type.
5270 Id := Equivalent_Type (Id);
5271 Set_Chars (Selector, Chars (Id));
5274 -- Ada 2005 (AI-50217): Check usage of entities in limited withed units
5276 if Ekind (P_Name) = E_Package
5277 and then From_With_Type (P_Name)
5279 if From_With_Type (Id)
5280 or else Is_Type (Id)
5281 or else Ekind (Id) = E_Package
5286 ("limited withed package can only be used to access "
5287 & "incomplete types",
5292 if Is_Task_Type (P_Name)
5293 and then ((Ekind (Id) = E_Entry
5294 and then Nkind (Parent (N)) /= N_Attribute_Reference)
5296 (Ekind (Id) = E_Entry_Family
5298 Nkind (Parent (Parent (N))) /= N_Attribute_Reference))
5300 -- It is an entry call after all, either to the current task (which
5301 -- will deadlock) or to an enclosing task.
5303 Analyze_Selected_Component (N);
5307 Change_Selected_Component_To_Expanded_Name (N);
5309 -- Do style check and generate reference, but skip both steps if this
5310 -- entity has homonyms, since we may not have the right homonym set yet.
5311 -- The proper homonym will be set during the resolve phase.
5313 if Has_Homonym (Id) then
5316 Set_Entity_Or_Discriminal (N, Id);
5319 Generate_Reference (Id, N, 'm');
5321 Generate_Reference (Id, N);
5325 if Is_Type (Id) then
5328 Set_Etype (N, Get_Full_View (Etype (Id)));
5331 -- Check for violation of No_Wide_Characters
5333 Check_Wide_Character_Restriction (Id, N);
5335 -- If the Ekind of the entity is Void, it means that all homonyms are
5336 -- hidden from all visibility (RM 8.3(5,14-20)).
5338 if Ekind (Id) = E_Void then
5339 Premature_Usage (N);
5341 elsif Is_Overloadable (Id)
5342 and then Present (Homonym (Id))
5345 H : Entity_Id := Homonym (Id);
5348 while Present (H) loop
5349 if Scope (H) = Scope (Id)
5352 or else Is_Immediately_Visible (H))
5354 Collect_Interps (N);
5361 -- If an extension of System is present, collect possible explicit
5362 -- overloadings declared in the extension.
5364 if Chars (P_Name) = Name_System
5365 and then Scope (P_Name) = Standard_Standard
5366 and then Present (System_Extend_Unit)
5367 and then Present_System_Aux (N)
5369 H := Current_Entity (Id);
5371 while Present (H) loop
5372 if Scope (H) = System_Aux_Id then
5373 Add_One_Interp (N, H, Etype (H));
5382 if Nkind (Selector_Name (N)) = N_Operator_Symbol
5383 and then Scope (Id) /= Standard_Standard
5385 -- In addition to user-defined operators in the given scope, there
5386 -- may be an implicit instance of the predefined operator. The
5387 -- operator (defined in Standard) is found in Has_Implicit_Operator,
5388 -- and added to the interpretations. Procedure Add_One_Interp will
5389 -- determine which hides which.
5391 if Has_Implicit_Operator (N) then
5395 end Find_Expanded_Name;
5397 -------------------------
5398 -- Find_Renamed_Entity --
5399 -------------------------
5401 function Find_Renamed_Entity
5405 Is_Actual : Boolean := False) return Entity_Id
5408 I1 : Interp_Index := 0; -- Suppress junk warnings
5414 function Enclosing_Instance return Entity_Id;
5415 -- If the renaming determines the entity for the default of a formal
5416 -- subprogram nested within another instance, choose the innermost
5417 -- candidate. This is because if the formal has a box, and we are within
5418 -- an enclosing instance where some candidate interpretations are local
5419 -- to this enclosing instance, we know that the default was properly
5420 -- resolved when analyzing the generic, so we prefer the local
5421 -- candidates to those that are external. This is not always the case
5422 -- but is a reasonable heuristic on the use of nested generics. The
5423 -- proper solution requires a full renaming model.
5425 function Is_Visible_Operation (Op : Entity_Id) return Boolean;
5426 -- If the renamed entity is an implicit operator, check whether it is
5427 -- visible because its operand type is properly visible. This check
5428 -- applies to explicit renamed entities that appear in the source in a
5429 -- renaming declaration or a formal subprogram instance, but not to
5430 -- default generic actuals with a name.
5432 function Report_Overload return Entity_Id;
5433 -- List possible interpretations, and specialize message in the
5434 -- case of a generic actual.
5436 function Within (Inner, Outer : Entity_Id) return Boolean;
5437 -- Determine whether a candidate subprogram is defined within the
5438 -- enclosing instance. If yes, it has precedence over outer candidates.
5440 ------------------------
5441 -- Enclosing_Instance --
5442 ------------------------
5444 function Enclosing_Instance return Entity_Id is
5448 if not Is_Generic_Instance (Current_Scope)
5449 and then not Is_Actual
5454 S := Scope (Current_Scope);
5455 while S /= Standard_Standard loop
5456 if Is_Generic_Instance (S) then
5464 end Enclosing_Instance;
5466 --------------------------
5467 -- Is_Visible_Operation --
5468 --------------------------
5470 function Is_Visible_Operation (Op : Entity_Id) return Boolean is
5476 if Ekind (Op) /= E_Operator
5477 or else Scope (Op) /= Standard_Standard
5478 or else (In_Instance
5481 or else Present (Enclosing_Instance)))
5486 -- For a fixed point type operator, check the resulting type,
5487 -- because it may be a mixed mode integer * fixed operation.
5489 if Present (Next_Formal (First_Formal (New_S)))
5490 and then Is_Fixed_Point_Type (Etype (New_S))
5492 Typ := Etype (New_S);
5494 Typ := Etype (First_Formal (New_S));
5497 Btyp := Base_Type (Typ);
5499 if Nkind (Nam) /= N_Expanded_Name then
5500 return (In_Open_Scopes (Scope (Btyp))
5501 or else Is_Potentially_Use_Visible (Btyp)
5502 or else In_Use (Btyp)
5503 or else In_Use (Scope (Btyp)));
5506 Scop := Entity (Prefix (Nam));
5508 if Ekind (Scop) = E_Package
5509 and then Present (Renamed_Object (Scop))
5511 Scop := Renamed_Object (Scop);
5514 -- Operator is visible if prefix of expanded name denotes
5515 -- scope of type, or else type is defined in System_Aux
5516 -- and the prefix denotes System.
5518 return Scope (Btyp) = Scop
5519 or else (Scope (Btyp) = System_Aux_Id
5520 and then Scope (Scope (Btyp)) = Scop);
5523 end Is_Visible_Operation;
5529 function Within (Inner, Outer : Entity_Id) return Boolean is
5533 Sc := Scope (Inner);
5534 while Sc /= Standard_Standard loop
5545 ---------------------
5546 -- Report_Overload --
5547 ---------------------
5549 function Report_Overload return Entity_Id is
5552 Error_Msg_NE -- CODEFIX
5553 ("ambiguous actual subprogram&, " &
5554 "possible interpretations:", N, Nam);
5556 Error_Msg_N -- CODEFIX
5557 ("ambiguous subprogram, " &
5558 "possible interpretations:", N);
5561 List_Interps (Nam, N);
5563 end Report_Overload;
5565 -- Start of processing for Find_Renamed_Entity
5569 Candidate_Renaming := Empty;
5571 if not Is_Overloaded (Nam) then
5572 if Entity_Matches_Spec (Entity (Nam), New_S) then
5573 Candidate_Renaming := New_S;
5575 if Is_Visible_Operation (Entity (Nam)) then
5576 Old_S := Entity (Nam);
5580 Present (First_Formal (Entity (Nam)))
5581 and then Present (First_Formal (New_S))
5582 and then (Base_Type (Etype (First_Formal (Entity (Nam))))
5583 = Base_Type (Etype (First_Formal (New_S))))
5585 Candidate_Renaming := Entity (Nam);
5589 Get_First_Interp (Nam, Ind, It);
5590 while Present (It.Nam) loop
5591 if Entity_Matches_Spec (It.Nam, New_S)
5592 and then Is_Visible_Operation (It.Nam)
5594 if Old_S /= Any_Id then
5596 -- Note: The call to Disambiguate only happens if a
5597 -- previous interpretation was found, in which case I1
5598 -- has received a value.
5600 It1 := Disambiguate (Nam, I1, Ind, Etype (Old_S));
5602 if It1 = No_Interp then
5603 Inst := Enclosing_Instance;
5605 if Present (Inst) then
5606 if Within (It.Nam, Inst) then
5607 if Within (Old_S, Inst) then
5609 -- Choose the innermost subprogram, which would
5610 -- have hidden the outer one in the generic.
5612 if Scope_Depth (It.Nam) <
5621 elsif Within (Old_S, Inst) then
5625 return Report_Overload;
5628 -- If not within an instance, ambiguity is real
5631 return Report_Overload;
5645 Present (First_Formal (It.Nam))
5646 and then Present (First_Formal (New_S))
5647 and then (Base_Type (Etype (First_Formal (It.Nam)))
5648 = Base_Type (Etype (First_Formal (New_S))))
5650 Candidate_Renaming := It.Nam;
5653 Get_Next_Interp (Ind, It);
5656 Set_Entity (Nam, Old_S);
5658 if Old_S /= Any_Id then
5659 Set_Is_Overloaded (Nam, False);
5664 end Find_Renamed_Entity;
5666 -----------------------------
5667 -- Find_Selected_Component --
5668 -----------------------------
5670 procedure Find_Selected_Component (N : Node_Id) is
5671 P : constant Node_Id := Prefix (N);
5674 -- Entity denoted by prefix
5684 if Nkind (P) = N_Error then
5688 -- Selector name cannot be a character literal or an operator symbol in
5689 -- SPARK, except for the operator symbol in a renaming.
5691 if Restriction_Check_Required (SPARK) then
5692 if Nkind (Selector_Name (N)) = N_Character_Literal then
5693 Check_SPARK_Restriction
5694 ("character literal cannot be prefixed", N);
5695 elsif Nkind (Selector_Name (N)) = N_Operator_Symbol
5696 and then Nkind (Parent (N)) /= N_Subprogram_Renaming_Declaration
5698 Check_SPARK_Restriction ("operator symbol cannot be prefixed", N);
5702 -- If the selector already has an entity, the node has been constructed
5703 -- in the course of expansion, and is known to be valid. Do not verify
5704 -- that it is defined for the type (it may be a private component used
5705 -- in the expansion of record equality).
5707 if Present (Entity (Selector_Name (N))) then
5709 or else Etype (N) = Any_Type
5712 Sel_Name : constant Node_Id := Selector_Name (N);
5713 Selector : constant Entity_Id := Entity (Sel_Name);
5717 Set_Etype (Sel_Name, Etype (Selector));
5719 if not Is_Entity_Name (P) then
5723 -- Build an actual subtype except for the first parameter
5724 -- of an init proc, where this actual subtype is by
5725 -- definition incorrect, since the object is uninitialized
5726 -- (and does not even have defined discriminants etc.)
5728 if Is_Entity_Name (P)
5729 and then Ekind (Entity (P)) = E_Function
5731 Nam := New_Copy (P);
5733 if Is_Overloaded (P) then
5734 Save_Interps (P, Nam);
5738 Make_Function_Call (Sloc (P), Name => Nam));
5740 Analyze_Selected_Component (N);
5743 elsif Ekind (Selector) = E_Component
5744 and then (not Is_Entity_Name (P)
5745 or else Chars (Entity (P)) /= Name_uInit)
5747 -- Do not build the subtype when referencing components of
5748 -- dispatch table wrappers. Required to avoid generating
5749 -- elaboration code with HI runtimes. JVM and .NET use a
5750 -- modified version of Ada.Tags which does not contain RE_
5751 -- Dispatch_Table_Wrapper and RE_No_Dispatch_Table_Wrapper.
5752 -- Avoid raising RE_Not_Available exception in those cases.
5754 if VM_Target = No_VM
5755 and then RTU_Loaded (Ada_Tags)
5757 ((RTE_Available (RE_Dispatch_Table_Wrapper)
5758 and then Scope (Selector) =
5759 RTE (RE_Dispatch_Table_Wrapper))
5761 (RTE_Available (RE_No_Dispatch_Table_Wrapper)
5762 and then Scope (Selector) =
5763 RTE (RE_No_Dispatch_Table_Wrapper)))
5769 Build_Actual_Subtype_Of_Component
5770 (Etype (Selector), N);
5777 if No (C_Etype) then
5778 C_Etype := Etype (Selector);
5780 Insert_Action (N, C_Etype);
5781 C_Etype := Defining_Identifier (C_Etype);
5784 Set_Etype (N, C_Etype);
5787 -- If this is the name of an entry or protected operation, and
5788 -- the prefix is an access type, insert an explicit dereference,
5789 -- so that entry calls are treated uniformly.
5791 if Is_Access_Type (Etype (P))
5792 and then Is_Concurrent_Type (Designated_Type (Etype (P)))
5795 New_P : constant Node_Id :=
5796 Make_Explicit_Dereference (Sloc (P),
5797 Prefix => Relocate_Node (P));
5800 Set_Etype (P, Designated_Type (Etype (Prefix (P))));
5804 -- If the selected component appears within a default expression
5805 -- and it has an actual subtype, the pre-analysis has not yet
5806 -- completed its analysis, because Insert_Actions is disabled in
5807 -- that context. Within the init proc of the enclosing type we
5808 -- must complete this analysis, if an actual subtype was created.
5810 elsif Inside_Init_Proc then
5812 Typ : constant Entity_Id := Etype (N);
5813 Decl : constant Node_Id := Declaration_Node (Typ);
5815 if Nkind (Decl) = N_Subtype_Declaration
5816 and then not Analyzed (Decl)
5817 and then Is_List_Member (Decl)
5818 and then No (Parent (Decl))
5821 Insert_Action (N, Decl);
5828 elsif Is_Entity_Name (P) then
5829 P_Name := Entity (P);
5831 -- The prefix may denote an enclosing type which is the completion
5832 -- of an incomplete type declaration.
5834 if Is_Type (P_Name) then
5835 Set_Entity (P, Get_Full_View (P_Name));
5836 Set_Etype (P, Entity (P));
5837 P_Name := Entity (P);
5840 P_Type := Base_Type (Etype (P));
5842 if Debug_Flag_E then
5843 Write_Str ("Found prefix type to be ");
5844 Write_Entity_Info (P_Type, " "); Write_Eol;
5847 -- First check for components of a record object (not the
5848 -- result of a call, which is handled below).
5850 if Is_Appropriate_For_Record (P_Type)
5851 and then not Is_Overloadable (P_Name)
5852 and then not Is_Type (P_Name)
5854 -- Selected component of record. Type checking will validate
5855 -- name of selector.
5856 -- ??? could we rewrite an implicit dereference into an explicit
5859 Analyze_Selected_Component (N);
5861 -- Reference to type name in predicate/invariant expression
5863 elsif Is_Appropriate_For_Entry_Prefix (P_Type)
5864 and then not In_Open_Scopes (P_Name)
5865 and then (not Is_Concurrent_Type (Etype (P_Name))
5866 or else not In_Open_Scopes (Etype (P_Name)))
5868 -- Call to protected operation or entry. Type checking is
5869 -- needed on the prefix.
5871 Analyze_Selected_Component (N);
5873 elsif (In_Open_Scopes (P_Name)
5874 and then Ekind (P_Name) /= E_Void
5875 and then not Is_Overloadable (P_Name))
5876 or else (Is_Concurrent_Type (Etype (P_Name))
5877 and then In_Open_Scopes (Etype (P_Name)))
5879 -- Prefix denotes an enclosing loop, block, or task, i.e. an
5880 -- enclosing construct that is not a subprogram or accept.
5882 Find_Expanded_Name (N);
5884 elsif Ekind (P_Name) = E_Package then
5885 Find_Expanded_Name (N);
5887 elsif Is_Overloadable (P_Name) then
5889 -- The subprogram may be a renaming (of an enclosing scope) as
5890 -- in the case of the name of the generic within an instantiation.
5892 if Ekind_In (P_Name, E_Procedure, E_Function)
5893 and then Present (Alias (P_Name))
5894 and then Is_Generic_Instance (Alias (P_Name))
5896 P_Name := Alias (P_Name);
5899 if Is_Overloaded (P) then
5901 -- The prefix must resolve to a unique enclosing construct
5904 Found : Boolean := False;
5909 Get_First_Interp (P, Ind, It);
5910 while Present (It.Nam) loop
5911 if In_Open_Scopes (It.Nam) then
5914 "prefix must be unique enclosing scope", N);
5915 Set_Entity (N, Any_Id);
5916 Set_Etype (N, Any_Type);
5925 Get_Next_Interp (Ind, It);
5930 if In_Open_Scopes (P_Name) then
5931 Set_Entity (P, P_Name);
5932 Set_Is_Overloaded (P, False);
5933 Find_Expanded_Name (N);
5936 -- If no interpretation as an expanded name is possible, it
5937 -- must be a selected component of a record returned by a
5938 -- function call. Reformat prefix as a function call, the rest
5939 -- is done by type resolution. If the prefix is procedure or
5940 -- entry, as is P.X; this is an error.
5942 if Ekind (P_Name) /= E_Function
5943 and then (not Is_Overloaded (P)
5945 Nkind (Parent (N)) = N_Procedure_Call_Statement)
5947 -- Prefix may mention a package that is hidden by a local
5948 -- declaration: let the user know. Scan the full homonym
5949 -- chain, the candidate package may be anywhere on it.
5951 if Present (Homonym (Current_Entity (P_Name))) then
5953 P_Name := Current_Entity (P_Name);
5955 while Present (P_Name) loop
5956 exit when Ekind (P_Name) = E_Package;
5957 P_Name := Homonym (P_Name);
5960 if Present (P_Name) then
5961 Error_Msg_Sloc := Sloc (Entity (Prefix (N)));
5964 ("package& is hidden by declaration#",
5967 Set_Entity (Prefix (N), P_Name);
5968 Find_Expanded_Name (N);
5971 P_Name := Entity (Prefix (N));
5976 ("invalid prefix in selected component&", N, P_Name);
5977 Change_Selected_Component_To_Expanded_Name (N);
5978 Set_Entity (N, Any_Id);
5979 Set_Etype (N, Any_Type);
5982 Nam := New_Copy (P);
5983 Save_Interps (P, Nam);
5985 Make_Function_Call (Sloc (P), Name => Nam));
5987 Analyze_Selected_Component (N);
5991 -- Remaining cases generate various error messages
5994 -- Format node as expanded name, to avoid cascaded errors
5996 Change_Selected_Component_To_Expanded_Name (N);
5997 Set_Entity (N, Any_Id);
5998 Set_Etype (N, Any_Type);
6000 -- Issue error message, but avoid this if error issued already.
6001 -- Use identifier of prefix if one is available.
6003 if P_Name = Any_Id then
6006 elsif Ekind (P_Name) = E_Void then
6007 Premature_Usage (P);
6009 elsif Nkind (P) /= N_Attribute_Reference then
6011 "invalid prefix in selected component&", P);
6013 if Is_Access_Type (P_Type)
6014 and then Ekind (Designated_Type (P_Type)) = E_Incomplete_Type
6017 ("\dereference must not be of an incomplete type " &
6023 "invalid prefix in selected component", P);
6027 -- Selector name is restricted in SPARK
6029 if Nkind (N) = N_Expanded_Name
6030 and then Restriction_Check_Required (SPARK)
6032 if Is_Subprogram (P_Name) then
6033 Check_SPARK_Restriction
6034 ("prefix of expanded name cannot be a subprogram", P);
6035 elsif Ekind (P_Name) = E_Loop then
6036 Check_SPARK_Restriction
6037 ("prefix of expanded name cannot be a loop statement", P);
6042 -- If prefix is not the name of an entity, it must be an expression,
6043 -- whose type is appropriate for a record. This is determined by
6046 Analyze_Selected_Component (N);
6048 end Find_Selected_Component;
6054 procedure Find_Type (N : Node_Id) is
6064 elsif Nkind (N) = N_Attribute_Reference then
6066 -- Class attribute. This is not valid in Ada 83 mode, but we do not
6067 -- need to enforce that at this point, since the declaration of the
6068 -- tagged type in the prefix would have been flagged already.
6070 if Attribute_Name (N) = Name_Class then
6071 Check_Restriction (No_Dispatch, N);
6072 Find_Type (Prefix (N));
6074 -- Propagate error from bad prefix
6076 if Etype (Prefix (N)) = Any_Type then
6077 Set_Entity (N, Any_Type);
6078 Set_Etype (N, Any_Type);
6082 T := Base_Type (Entity (Prefix (N)));
6084 -- Case where type is not known to be tagged. Its appearance in
6085 -- the prefix of the 'Class attribute indicates that the full view
6088 if not Is_Tagged_Type (T) then
6089 if Ekind (T) = E_Incomplete_Type then
6091 -- It is legal to denote the class type of an incomplete
6092 -- type. The full type will have to be tagged, of course.
6093 -- In Ada 2005 this usage is declared obsolescent, so we
6094 -- warn accordingly. This usage is only legal if the type
6095 -- is completed in the current scope, and not for a limited
6098 if not Is_Tagged_Type (T)
6099 and then Ada_Version >= Ada_2005
6101 if From_With_Type (T) then
6103 ("prefix of Class attribute must be tagged", N);
6104 Set_Etype (N, Any_Type);
6105 Set_Entity (N, Any_Type);
6108 -- ??? This test is temporarily disabled (always False)
6109 -- because it causes an unwanted warning on GNAT sources
6110 -- (built with -gnatg, which includes Warn_On_Obsolescent_
6111 -- Feature). Once this issue is cleared in the sources, it
6114 elsif Warn_On_Obsolescent_Feature
6118 ("applying 'Class to an untagged incomplete type"
6119 & " is an obsolescent feature (RM J.11)", N);
6123 Set_Is_Tagged_Type (T);
6124 Set_Direct_Primitive_Operations (T, New_Elmt_List);
6125 Make_Class_Wide_Type (T);
6126 Set_Entity (N, Class_Wide_Type (T));
6127 Set_Etype (N, Class_Wide_Type (T));
6129 elsif Ekind (T) = E_Private_Type
6130 and then not Is_Generic_Type (T)
6131 and then In_Private_Part (Scope (T))
6133 -- The Class attribute can be applied to an untagged private
6134 -- type fulfilled by a tagged type prior to the full type
6135 -- declaration (but only within the parent package's private
6136 -- part). Create the class-wide type now and check that the
6137 -- full type is tagged later during its analysis. Note that
6138 -- we do not mark the private type as tagged, unlike the
6139 -- case of incomplete types, because the type must still
6140 -- appear untagged to outside units.
6142 if No (Class_Wide_Type (T)) then
6143 Make_Class_Wide_Type (T);
6146 Set_Entity (N, Class_Wide_Type (T));
6147 Set_Etype (N, Class_Wide_Type (T));
6150 -- Should we introduce a type Any_Tagged and use Wrong_Type
6151 -- here, it would be a bit more consistent???
6154 ("tagged type required, found}",
6155 Prefix (N), First_Subtype (T));
6156 Set_Entity (N, Any_Type);
6160 -- Case of tagged type
6163 if Is_Concurrent_Type (T) then
6164 if No (Corresponding_Record_Type (Entity (Prefix (N)))) then
6166 -- Previous error. Use current type, which at least
6167 -- provides some operations.
6169 C := Entity (Prefix (N));
6172 C := Class_Wide_Type
6173 (Corresponding_Record_Type (Entity (Prefix (N))));
6177 C := Class_Wide_Type (Entity (Prefix (N)));
6180 Set_Entity_With_Style_Check (N, C);
6181 Generate_Reference (C, N);
6185 -- Base attribute, not allowed in Ada 83
6187 elsif Attribute_Name (N) = Name_Base then
6188 Error_Msg_Name_1 := Name_Base;
6189 Check_SPARK_Restriction
6190 ("attribute% is only allowed as prefix of another attribute", N);
6192 if Ada_Version = Ada_83 and then Comes_From_Source (N) then
6194 ("(Ada 83) Base attribute not allowed in subtype mark", N);
6197 Find_Type (Prefix (N));
6198 Typ := Entity (Prefix (N));
6200 if Ada_Version >= Ada_95
6201 and then not Is_Scalar_Type (Typ)
6202 and then not Is_Generic_Type (Typ)
6205 ("prefix of Base attribute must be scalar type",
6208 elsif Warn_On_Redundant_Constructs
6209 and then Base_Type (Typ) = Typ
6211 Error_Msg_NE -- CODEFIX
6212 ("?redundant attribute, & is its own base type", N, Typ);
6215 T := Base_Type (Typ);
6217 -- Rewrite attribute reference with type itself (see similar
6218 -- processing in Analyze_Attribute, case Base). Preserve prefix
6219 -- if present, for other legality checks.
6221 if Nkind (Prefix (N)) = N_Expanded_Name then
6223 Make_Expanded_Name (Sloc (N),
6225 Prefix => New_Copy (Prefix (Prefix (N))),
6226 Selector_Name => New_Reference_To (T, Sloc (N))));
6229 Rewrite (N, New_Reference_To (T, Sloc (N)));
6236 elsif Attribute_Name (N) = Name_Stub_Type then
6238 -- This is handled in Analyze_Attribute
6242 -- All other attributes are invalid in a subtype mark
6245 Error_Msg_N ("invalid attribute in subtype mark", N);
6251 if Is_Entity_Name (N) then
6252 T_Name := Entity (N);
6254 Error_Msg_N ("subtype mark required in this context", N);
6255 Set_Etype (N, Any_Type);
6259 if T_Name = Any_Id or else Etype (N) = Any_Type then
6261 -- Undefined id. Make it into a valid type
6263 Set_Entity (N, Any_Type);
6265 elsif not Is_Type (T_Name)
6266 and then T_Name /= Standard_Void_Type
6268 Error_Msg_Sloc := Sloc (T_Name);
6269 Error_Msg_N ("subtype mark required in this context", N);
6270 Error_Msg_NE ("\\found & declared#", N, T_Name);
6271 Set_Entity (N, Any_Type);
6274 -- If the type is an incomplete type created to handle
6275 -- anonymous access components of a record type, then the
6276 -- incomplete type is the visible entity and subsequent
6277 -- references will point to it. Mark the original full
6278 -- type as referenced, to prevent spurious warnings.
6280 if Is_Incomplete_Type (T_Name)
6281 and then Present (Full_View (T_Name))
6282 and then not Comes_From_Source (T_Name)
6284 Set_Referenced (Full_View (T_Name));
6287 T_Name := Get_Full_View (T_Name);
6289 -- Ada 2005 (AI-251, AI-50217): Handle interfaces visible through
6290 -- limited-with clauses
6292 if From_With_Type (T_Name)
6293 and then Ekind (T_Name) in Incomplete_Kind
6294 and then Present (Non_Limited_View (T_Name))
6295 and then Is_Interface (Non_Limited_View (T_Name))
6297 T_Name := Non_Limited_View (T_Name);
6300 if In_Open_Scopes (T_Name) then
6301 if Ekind (Base_Type (T_Name)) = E_Task_Type then
6303 -- In Ada 2005, a task name can be used in an access
6304 -- definition within its own body. It cannot be used
6305 -- in the discriminant part of the task declaration,
6306 -- nor anywhere else in the declaration because entries
6307 -- cannot have access parameters.
6309 if Ada_Version >= Ada_2005
6310 and then Nkind (Parent (N)) = N_Access_Definition
6312 Set_Entity (N, T_Name);
6313 Set_Etype (N, T_Name);
6315 if Has_Completion (T_Name) then
6320 ("task type cannot be used as type mark " &
6321 "within its own declaration", N);
6326 ("task type cannot be used as type mark " &
6327 "within its own spec or body", N);
6330 elsif Ekind (Base_Type (T_Name)) = E_Protected_Type then
6332 -- In Ada 2005, a protected name can be used in an access
6333 -- definition within its own body.
6335 if Ada_Version >= Ada_2005
6336 and then Nkind (Parent (N)) = N_Access_Definition
6338 Set_Entity (N, T_Name);
6339 Set_Etype (N, T_Name);
6344 ("protected type cannot be used as type mark " &
6345 "within its own spec or body", N);
6349 Error_Msg_N ("type declaration cannot refer to itself", N);
6352 Set_Etype (N, Any_Type);
6353 Set_Entity (N, Any_Type);
6354 Set_Error_Posted (T_Name);
6358 Set_Entity (N, T_Name);
6359 Set_Etype (N, T_Name);
6363 if Present (Etype (N)) and then Comes_From_Source (N) then
6364 if Is_Fixed_Point_Type (Etype (N)) then
6365 Check_Restriction (No_Fixed_Point, N);
6366 elsif Is_Floating_Point_Type (Etype (N)) then
6367 Check_Restriction (No_Floating_Point, N);
6372 ------------------------------------
6373 -- Has_Implicit_Character_Literal --
6374 ------------------------------------
6376 function Has_Implicit_Character_Literal (N : Node_Id) return Boolean is
6378 Found : Boolean := False;
6379 P : constant Entity_Id := Entity (Prefix (N));
6380 Priv_Id : Entity_Id := Empty;
6383 if Ekind (P) = E_Package
6384 and then not In_Open_Scopes (P)
6386 Priv_Id := First_Private_Entity (P);
6389 if P = Standard_Standard then
6390 Change_Selected_Component_To_Expanded_Name (N);
6391 Rewrite (N, Selector_Name (N));
6393 Set_Etype (Original_Node (N), Standard_Character);
6397 Id := First_Entity (P);
6399 and then Id /= Priv_Id
6401 if Is_Standard_Character_Type (Id) and then Is_Base_Type (Id) then
6403 -- We replace the node with the literal itself, resolve as a
6404 -- character, and set the type correctly.
6407 Change_Selected_Component_To_Expanded_Name (N);
6408 Rewrite (N, Selector_Name (N));
6411 Set_Etype (Original_Node (N), Id);
6415 -- More than one type derived from Character in given scope.
6416 -- Collect all possible interpretations.
6418 Add_One_Interp (N, Id, Id);
6426 end Has_Implicit_Character_Literal;
6428 ----------------------
6429 -- Has_Private_With --
6430 ----------------------
6432 function Has_Private_With (E : Entity_Id) return Boolean is
6433 Comp_Unit : constant Node_Id := Cunit (Current_Sem_Unit);
6437 Item := First (Context_Items (Comp_Unit));
6438 while Present (Item) loop
6439 if Nkind (Item) = N_With_Clause
6440 and then Private_Present (Item)
6441 and then Entity (Name (Item)) = E
6450 end Has_Private_With;
6452 ---------------------------
6453 -- Has_Implicit_Operator --
6454 ---------------------------
6456 function Has_Implicit_Operator (N : Node_Id) return Boolean is
6457 Op_Id : constant Name_Id := Chars (Selector_Name (N));
6458 P : constant Entity_Id := Entity (Prefix (N));
6460 Priv_Id : Entity_Id := Empty;
6462 procedure Add_Implicit_Operator
6464 Op_Type : Entity_Id := Empty);
6465 -- Add implicit interpretation to node N, using the type for which a
6466 -- predefined operator exists. If the operator yields a boolean type,
6467 -- the Operand_Type is implicitly referenced by the operator, and a
6468 -- reference to it must be generated.
6470 ---------------------------
6471 -- Add_Implicit_Operator --
6472 ---------------------------
6474 procedure Add_Implicit_Operator
6476 Op_Type : Entity_Id := Empty)
6478 Predef_Op : Entity_Id;
6481 Predef_Op := Current_Entity (Selector_Name (N));
6483 while Present (Predef_Op)
6484 and then Scope (Predef_Op) /= Standard_Standard
6486 Predef_Op := Homonym (Predef_Op);
6489 if Nkind (N) = N_Selected_Component then
6490 Change_Selected_Component_To_Expanded_Name (N);
6493 -- If the context is an unanalyzed function call, determine whether
6494 -- a binary or unary interpretation is required.
6496 if Nkind (Parent (N)) = N_Indexed_Component then
6498 Is_Binary_Call : constant Boolean :=
6500 (Next (First (Expressions (Parent (N)))));
6501 Is_Binary_Op : constant Boolean :=
6503 (Predef_Op) /= Last_Entity (Predef_Op);
6504 Predef_Op2 : constant Entity_Id := Homonym (Predef_Op);
6507 if Is_Binary_Call then
6508 if Is_Binary_Op then
6509 Add_One_Interp (N, Predef_Op, T);
6511 Add_One_Interp (N, Predef_Op2, T);
6515 if not Is_Binary_Op then
6516 Add_One_Interp (N, Predef_Op, T);
6518 Add_One_Interp (N, Predef_Op2, T);
6524 Add_One_Interp (N, Predef_Op, T);
6526 -- For operators with unary and binary interpretations, if
6527 -- context is not a call, add both
6529 if Present (Homonym (Predef_Op)) then
6530 Add_One_Interp (N, Homonym (Predef_Op), T);
6534 -- The node is a reference to a predefined operator, and
6535 -- an implicit reference to the type of its operands.
6537 if Present (Op_Type) then
6538 Generate_Operator_Reference (N, Op_Type);
6540 Generate_Operator_Reference (N, T);
6542 end Add_Implicit_Operator;
6544 -- Start of processing for Has_Implicit_Operator
6547 if Ekind (P) = E_Package
6548 and then not In_Open_Scopes (P)
6550 Priv_Id := First_Private_Entity (P);
6553 Id := First_Entity (P);
6557 -- Boolean operators: an implicit declaration exists if the scope
6558 -- contains a declaration for a derived Boolean type, or for an
6559 -- array of Boolean type.
6561 when Name_Op_And | Name_Op_Not | Name_Op_Or | Name_Op_Xor =>
6562 while Id /= Priv_Id loop
6563 if Valid_Boolean_Arg (Id) and then Is_Base_Type (Id) then
6564 Add_Implicit_Operator (Id);
6571 -- Equality: look for any non-limited type (result is Boolean)
6573 when Name_Op_Eq | Name_Op_Ne =>
6574 while Id /= Priv_Id loop
6576 and then not Is_Limited_Type (Id)
6577 and then Is_Base_Type (Id)
6579 Add_Implicit_Operator (Standard_Boolean, Id);
6586 -- Comparison operators: scalar type, or array of scalar
6588 when Name_Op_Lt | Name_Op_Le | Name_Op_Gt | Name_Op_Ge =>
6589 while Id /= Priv_Id loop
6590 if (Is_Scalar_Type (Id)
6591 or else (Is_Array_Type (Id)
6592 and then Is_Scalar_Type (Component_Type (Id))))
6593 and then Is_Base_Type (Id)
6595 Add_Implicit_Operator (Standard_Boolean, Id);
6602 -- Arithmetic operators: any numeric type
6612 while Id /= Priv_Id loop
6613 if Is_Numeric_Type (Id) and then Is_Base_Type (Id) then
6614 Add_Implicit_Operator (Id);
6621 -- Concatenation: any one-dimensional array type
6623 when Name_Op_Concat =>
6624 while Id /= Priv_Id loop
6625 if Is_Array_Type (Id)
6626 and then Number_Dimensions (Id) = 1
6627 and then Is_Base_Type (Id)
6629 Add_Implicit_Operator (Id);
6636 -- What is the others condition here? Should we be using a
6637 -- subtype of Name_Id that would restrict to operators ???
6639 when others => null;
6642 -- If we fall through, then we do not have an implicit operator
6646 end Has_Implicit_Operator;
6648 -----------------------------------
6649 -- Has_Loop_In_Inner_Open_Scopes --
6650 -----------------------------------
6652 function Has_Loop_In_Inner_Open_Scopes (S : Entity_Id) return Boolean is
6654 -- Several scope stacks are maintained by Scope_Stack. The base of the
6655 -- currently active scope stack is denoted by the Is_Active_Stack_Base
6656 -- flag in the scope stack entry. Note that the scope stacks used to
6657 -- simply be delimited implicitly by the presence of Standard_Standard
6658 -- at their base, but there now are cases where this is not sufficient
6659 -- because Standard_Standard actually may appear in the middle of the
6660 -- active set of scopes.
6662 for J in reverse 0 .. Scope_Stack.Last loop
6664 -- S was reached without seing a loop scope first
6666 if Scope_Stack.Table (J).Entity = S then
6669 -- S was not yet reached, so it contains at least one inner loop
6671 elsif Ekind (Scope_Stack.Table (J).Entity) = E_Loop then
6675 -- Check Is_Active_Stack_Base to tell us when to stop, as there are
6676 -- cases where Standard_Standard appears in the middle of the active
6677 -- set of scopes. This affects the declaration and overriding of
6678 -- private inherited operations in instantiations of generic child
6681 pragma Assert (not Scope_Stack.Table (J).Is_Active_Stack_Base);
6684 raise Program_Error; -- unreachable
6685 end Has_Loop_In_Inner_Open_Scopes;
6687 --------------------
6688 -- In_Open_Scopes --
6689 --------------------
6691 function In_Open_Scopes (S : Entity_Id) return Boolean is
6693 -- Several scope stacks are maintained by Scope_Stack. The base of the
6694 -- currently active scope stack is denoted by the Is_Active_Stack_Base
6695 -- flag in the scope stack entry. Note that the scope stacks used to
6696 -- simply be delimited implicitly by the presence of Standard_Standard
6697 -- at their base, but there now are cases where this is not sufficient
6698 -- because Standard_Standard actually may appear in the middle of the
6699 -- active set of scopes.
6701 for J in reverse 0 .. Scope_Stack.Last loop
6702 if Scope_Stack.Table (J).Entity = S then
6706 -- Check Is_Active_Stack_Base to tell us when to stop, as there are
6707 -- cases where Standard_Standard appears in the middle of the active
6708 -- set of scopes. This affects the declaration and overriding of
6709 -- private inherited operations in instantiations of generic child
6712 exit when Scope_Stack.Table (J).Is_Active_Stack_Base;
6718 -----------------------------
6719 -- Inherit_Renamed_Profile --
6720 -----------------------------
6722 procedure Inherit_Renamed_Profile (New_S : Entity_Id; Old_S : Entity_Id) is
6729 if Ekind (Old_S) = E_Operator then
6730 New_F := First_Formal (New_S);
6732 while Present (New_F) loop
6733 Set_Etype (New_F, Base_Type (Etype (New_F)));
6734 Next_Formal (New_F);
6737 Set_Etype (New_S, Base_Type (Etype (New_S)));
6740 New_F := First_Formal (New_S);
6741 Old_F := First_Formal (Old_S);
6743 while Present (New_F) loop
6744 New_T := Etype (New_F);
6745 Old_T := Etype (Old_F);
6747 -- If the new type is a renaming of the old one, as is the
6748 -- case for actuals in instances, retain its name, to simplify
6749 -- later disambiguation.
6751 if Nkind (Parent (New_T)) = N_Subtype_Declaration
6752 and then Is_Entity_Name (Subtype_Indication (Parent (New_T)))
6753 and then Entity (Subtype_Indication (Parent (New_T))) = Old_T
6757 Set_Etype (New_F, Old_T);
6760 Next_Formal (New_F);
6761 Next_Formal (Old_F);
6764 if Ekind_In (Old_S, E_Function, E_Enumeration_Literal) then
6765 Set_Etype (New_S, Etype (Old_S));
6768 end Inherit_Renamed_Profile;
6774 procedure Initialize is
6779 -------------------------
6780 -- Install_Use_Clauses --
6781 -------------------------
6783 procedure Install_Use_Clauses
6785 Force_Installation : Boolean := False)
6793 while Present (U) loop
6795 -- Case of USE package
6797 if Nkind (U) = N_Use_Package_Clause then
6798 P := First (Names (U));
6799 while Present (P) loop
6802 if Ekind (Id) = E_Package then
6804 Note_Redundant_Use (P);
6806 elsif Present (Renamed_Object (Id))
6807 and then In_Use (Renamed_Object (Id))
6809 Note_Redundant_Use (P);
6811 elsif Force_Installation or else Applicable_Use (P) then
6812 Use_One_Package (Id, U);
6823 P := First (Subtype_Marks (U));
6824 while Present (P) loop
6825 if not Is_Entity_Name (P)
6826 or else No (Entity (P))
6830 elsif Entity (P) /= Any_Type then
6838 Next_Use_Clause (U);
6840 end Install_Use_Clauses;
6842 -------------------------------------
6843 -- Is_Appropriate_For_Entry_Prefix --
6844 -------------------------------------
6846 function Is_Appropriate_For_Entry_Prefix (T : Entity_Id) return Boolean is
6847 P_Type : Entity_Id := T;
6850 if Is_Access_Type (P_Type) then
6851 P_Type := Designated_Type (P_Type);
6854 return Is_Task_Type (P_Type) or else Is_Protected_Type (P_Type);
6855 end Is_Appropriate_For_Entry_Prefix;
6857 -------------------------------
6858 -- Is_Appropriate_For_Record --
6859 -------------------------------
6861 function Is_Appropriate_For_Record (T : Entity_Id) return Boolean is
6863 function Has_Components (T1 : Entity_Id) return Boolean;
6864 -- Determine if given type has components (i.e. is either a record
6865 -- type or a type that has discriminants).
6867 --------------------
6868 -- Has_Components --
6869 --------------------
6871 function Has_Components (T1 : Entity_Id) return Boolean is
6873 return Is_Record_Type (T1)
6874 or else (Is_Private_Type (T1) and then Has_Discriminants (T1))
6875 or else (Is_Task_Type (T1) and then Has_Discriminants (T1))
6876 or else (Is_Incomplete_Type (T1)
6877 and then From_With_Type (T1)
6878 and then Present (Non_Limited_View (T1))
6879 and then Is_Record_Type
6880 (Get_Full_View (Non_Limited_View (T1))));
6883 -- Start of processing for Is_Appropriate_For_Record
6888 and then (Has_Components (T)
6889 or else (Is_Access_Type (T)
6890 and then Has_Components (Designated_Type (T))));
6891 end Is_Appropriate_For_Record;
6893 ------------------------
6894 -- Note_Redundant_Use --
6895 ------------------------
6897 procedure Note_Redundant_Use (Clause : Node_Id) is
6898 Pack_Name : constant Entity_Id := Entity (Clause);
6899 Cur_Use : constant Node_Id := Current_Use_Clause (Pack_Name);
6900 Decl : constant Node_Id := Parent (Clause);
6902 Prev_Use : Node_Id := Empty;
6903 Redundant : Node_Id := Empty;
6904 -- The Use_Clause which is actually redundant. In the simplest case it
6905 -- is Pack itself, but when we compile a body we install its context
6906 -- before that of its spec, in which case it is the use_clause in the
6907 -- spec that will appear to be redundant, and we want the warning to be
6908 -- placed on the body. Similar complications appear when the redundancy
6909 -- is between a child unit and one of its ancestors.
6912 Set_Redundant_Use (Clause, True);
6914 if not Comes_From_Source (Clause)
6916 or else not Warn_On_Redundant_Constructs
6921 if not Is_Compilation_Unit (Current_Scope) then
6923 -- If the use_clause is in an inner scope, it is made redundant by
6924 -- some clause in the current context, with one exception: If we're
6925 -- compiling a nested package body, and the use_clause comes from the
6926 -- corresponding spec, the clause is not necessarily fully redundant,
6927 -- so we should not warn. If a warning was warranted, it would have
6928 -- been given when the spec was processed.
6930 if Nkind (Parent (Decl)) = N_Package_Specification then
6932 Package_Spec_Entity : constant Entity_Id :=
6933 Defining_Unit_Name (Parent (Decl));
6935 if In_Package_Body (Package_Spec_Entity) then
6941 Redundant := Clause;
6942 Prev_Use := Cur_Use;
6944 elsif Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Body then
6946 Cur_Unit : constant Unit_Number_Type := Get_Source_Unit (Cur_Use);
6947 New_Unit : constant Unit_Number_Type := Get_Source_Unit (Clause);
6951 if Cur_Unit = New_Unit then
6953 -- Redundant clause in same body
6955 Redundant := Clause;
6956 Prev_Use := Cur_Use;
6958 elsif Cur_Unit = Current_Sem_Unit then
6960 -- If the new clause is not in the current unit it has been
6961 -- analyzed first, and it makes the other one redundant.
6962 -- However, if the new clause appears in a subunit, Cur_Unit
6963 -- is still the parent, and in that case the redundant one
6964 -- is the one appearing in the subunit.
6966 if Nkind (Unit (Cunit (New_Unit))) = N_Subunit then
6967 Redundant := Clause;
6968 Prev_Use := Cur_Use;
6970 -- Most common case: redundant clause in body,
6971 -- original clause in spec. Current scope is spec entity.
6976 Unit (Library_Unit (Cunit (Current_Sem_Unit))))
6978 Redundant := Cur_Use;
6982 -- The new clause may appear in an unrelated unit, when
6983 -- the parents of a generic are being installed prior to
6984 -- instantiation. In this case there must be no warning.
6985 -- We detect this case by checking whether the current top
6986 -- of the stack is related to the current compilation.
6988 Scop := Current_Scope;
6989 while Present (Scop)
6990 and then Scop /= Standard_Standard
6992 if Is_Compilation_Unit (Scop)
6993 and then not Is_Child_Unit (Scop)
6997 elsif Scop = Cunit_Entity (Current_Sem_Unit) then
7001 Scop := Scope (Scop);
7004 Redundant := Cur_Use;
7008 elsif New_Unit = Current_Sem_Unit then
7009 Redundant := Clause;
7010 Prev_Use := Cur_Use;
7013 -- Neither is the current unit, so they appear in parent or
7014 -- sibling units. Warning will be emitted elsewhere.
7020 elsif Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Declaration
7021 and then Present (Parent_Spec (Unit (Cunit (Current_Sem_Unit))))
7023 -- Use_clause is in child unit of current unit, and the child unit
7024 -- appears in the context of the body of the parent, so it has been
7025 -- installed first, even though it is the redundant one. Depending on
7026 -- their placement in the context, the visible or the private parts
7027 -- of the two units, either might appear as redundant, but the
7028 -- message has to be on the current unit.
7030 if Get_Source_Unit (Cur_Use) = Current_Sem_Unit then
7031 Redundant := Cur_Use;
7034 Redundant := Clause;
7035 Prev_Use := Cur_Use;
7038 -- If the new use clause appears in the private part of a parent unit
7039 -- it may appear to be redundant w.r.t. a use clause in a child unit,
7040 -- but the previous use clause was needed in the visible part of the
7041 -- child, and no warning should be emitted.
7043 if Nkind (Parent (Decl)) = N_Package_Specification
7045 List_Containing (Decl) = Private_Declarations (Parent (Decl))
7048 Par : constant Entity_Id := Defining_Entity (Parent (Decl));
7049 Spec : constant Node_Id :=
7050 Specification (Unit (Cunit (Current_Sem_Unit)));
7053 if Is_Compilation_Unit (Par)
7054 and then Par /= Cunit_Entity (Current_Sem_Unit)
7055 and then Parent (Cur_Use) = Spec
7057 List_Containing (Cur_Use) = Visible_Declarations (Spec)
7064 -- Finally, if the current use clause is in the context then
7065 -- the clause is redundant when it is nested within the unit.
7067 elsif Nkind (Parent (Cur_Use)) = N_Compilation_Unit
7068 and then Nkind (Parent (Parent (Clause))) /= N_Compilation_Unit
7069 and then Get_Source_Unit (Cur_Use) = Get_Source_Unit (Clause)
7071 Redundant := Clause;
7072 Prev_Use := Cur_Use;
7078 if Present (Redundant) then
7079 Error_Msg_Sloc := Sloc (Prev_Use);
7080 Error_Msg_NE -- CODEFIX
7081 ("& is already use-visible through previous use clause #?",
7082 Redundant, Pack_Name);
7084 end Note_Redundant_Use;
7090 procedure Pop_Scope is
7091 SST : Scope_Stack_Entry renames Scope_Stack.Table (Scope_Stack.Last);
7092 S : constant Entity_Id := SST.Entity;
7095 if Debug_Flag_E then
7099 -- Set Default_Storage_Pool field of the library unit if necessary
7101 if Ekind_In (S, E_Package, E_Generic_Package)
7103 Nkind (Parent (Unit_Declaration_Node (S))) = N_Compilation_Unit
7106 Aux : constant Node_Id :=
7107 Aux_Decls_Node (Parent (Unit_Declaration_Node (S)));
7109 if No (Default_Storage_Pool (Aux)) then
7110 Set_Default_Storage_Pool (Aux, Default_Pool);
7115 Scope_Suppress := SST.Save_Scope_Suppress;
7116 Local_Suppress_Stack_Top := SST.Save_Local_Suppress_Stack_Top;
7117 Check_Policy_List := SST.Save_Check_Policy_List;
7118 Default_Pool := SST.Save_Default_Storage_Pool;
7120 if Debug_Flag_W then
7121 Write_Str ("<-- exiting scope: ");
7122 Write_Name (Chars (Current_Scope));
7123 Write_Str (", Depth=");
7124 Write_Int (Int (Scope_Stack.Last));
7128 End_Use_Clauses (SST.First_Use_Clause);
7130 -- If the actions to be wrapped are still there they will get lost
7131 -- causing incomplete code to be generated. It is better to abort in
7132 -- this case (and we do the abort even with assertions off since the
7133 -- penalty is incorrect code generation)
7135 if SST.Actions_To_Be_Wrapped_Before /= No_List
7137 SST.Actions_To_Be_Wrapped_After /= No_List
7139 raise Program_Error;
7142 -- Free last subprogram name if allocated, and pop scope
7144 Free (SST.Last_Subprogram_Name);
7145 Scope_Stack.Decrement_Last;
7152 procedure Push_Scope (S : Entity_Id) is
7153 E : constant Entity_Id := Scope (S);
7156 if Ekind (S) = E_Void then
7159 -- Set scope depth if not a non-concurrent type, and we have not yet set
7160 -- the scope depth. This means that we have the first occurrence of the
7161 -- scope, and this is where the depth is set.
7163 elsif (not Is_Type (S) or else Is_Concurrent_Type (S))
7164 and then not Scope_Depth_Set (S)
7166 if S = Standard_Standard then
7167 Set_Scope_Depth_Value (S, Uint_0);
7169 elsif Is_Child_Unit (S) then
7170 Set_Scope_Depth_Value (S, Uint_1);
7172 elsif not Is_Record_Type (Current_Scope) then
7173 if Ekind (S) = E_Loop then
7174 Set_Scope_Depth_Value (S, Scope_Depth (Current_Scope));
7176 Set_Scope_Depth_Value (S, Scope_Depth (Current_Scope) + 1);
7181 Scope_Stack.Increment_Last;
7184 SST : Scope_Stack_Entry renames Scope_Stack.Table (Scope_Stack.Last);
7188 SST.Save_Scope_Suppress := Scope_Suppress;
7189 SST.Save_Local_Suppress_Stack_Top := Local_Suppress_Stack_Top;
7190 SST.Save_Check_Policy_List := Check_Policy_List;
7191 SST.Save_Default_Storage_Pool := Default_Pool;
7193 if Scope_Stack.Last > Scope_Stack.First then
7194 SST.Component_Alignment_Default := Scope_Stack.Table
7195 (Scope_Stack.Last - 1).
7196 Component_Alignment_Default;
7199 SST.Last_Subprogram_Name := null;
7200 SST.Is_Transient := False;
7201 SST.Node_To_Be_Wrapped := Empty;
7202 SST.Pending_Freeze_Actions := No_List;
7203 SST.Actions_To_Be_Wrapped_Before := No_List;
7204 SST.Actions_To_Be_Wrapped_After := No_List;
7205 SST.First_Use_Clause := Empty;
7206 SST.Is_Active_Stack_Base := False;
7207 SST.Previous_Visibility := False;
7210 if Debug_Flag_W then
7211 Write_Str ("--> new scope: ");
7212 Write_Name (Chars (Current_Scope));
7213 Write_Str (", Id=");
7214 Write_Int (Int (Current_Scope));
7215 Write_Str (", Depth=");
7216 Write_Int (Int (Scope_Stack.Last));
7220 -- Deal with copying flags from the previous scope to this one. This is
7221 -- not necessary if either scope is standard, or if the new scope is a
7224 if S /= Standard_Standard
7225 and then Scope (S) /= Standard_Standard
7226 and then not Is_Child_Unit (S)
7228 if Nkind (E) not in N_Entity then
7232 -- Copy categorization flags from Scope (S) to S, this is not done
7233 -- when Scope (S) is Standard_Standard since propagation is from
7234 -- library unit entity inwards. Copy other relevant attributes as
7235 -- well (Discard_Names in particular).
7237 -- We only propagate inwards for library level entities,
7238 -- inner level subprograms do not inherit the categorization.
7240 if Is_Library_Level_Entity (S) then
7241 Set_Is_Preelaborated (S, Is_Preelaborated (E));
7242 Set_Is_Shared_Passive (S, Is_Shared_Passive (E));
7243 Set_Discard_Names (S, Discard_Names (E));
7244 Set_Suppress_Value_Tracking_On_Call
7245 (S, Suppress_Value_Tracking_On_Call (E));
7246 Set_Categorization_From_Scope (E => S, Scop => E);
7250 if Is_Child_Unit (S)
7251 and then Present (E)
7252 and then Ekind_In (E, E_Package, E_Generic_Package)
7254 Nkind (Parent (Unit_Declaration_Node (E))) = N_Compilation_Unit
7257 Aux : constant Node_Id :=
7258 Aux_Decls_Node (Parent (Unit_Declaration_Node (E)));
7260 if Present (Default_Storage_Pool (Aux)) then
7261 Default_Pool := Default_Storage_Pool (Aux);
7267 ---------------------
7268 -- Premature_Usage --
7269 ---------------------
7271 procedure Premature_Usage (N : Node_Id) is
7272 Kind : constant Node_Kind := Nkind (Parent (Entity (N)));
7273 E : Entity_Id := Entity (N);
7276 -- Within an instance, the analysis of the actual for a formal object
7277 -- does not see the name of the object itself. This is significant only
7278 -- if the object is an aggregate, where its analysis does not do any
7279 -- name resolution on component associations. (see 4717-008). In such a
7280 -- case, look for the visible homonym on the chain.
7283 and then Present (Homonym (E))
7288 and then not In_Open_Scopes (Scope (E))
7295 Set_Etype (N, Etype (E));
7300 if Kind = N_Component_Declaration then
7302 ("component&! cannot be used before end of record declaration", N);
7304 elsif Kind = N_Parameter_Specification then
7306 ("formal parameter&! cannot be used before end of specification",
7309 elsif Kind = N_Discriminant_Specification then
7311 ("discriminant&! cannot be used before end of discriminant part",
7314 elsif Kind = N_Procedure_Specification
7315 or else Kind = N_Function_Specification
7318 ("subprogram&! cannot be used before end of its declaration",
7321 elsif Kind = N_Full_Type_Declaration then
7323 ("type& cannot be used before end of its declaration!", N);
7327 ("object& cannot be used before end of its declaration!", N);
7329 end Premature_Usage;
7331 ------------------------
7332 -- Present_System_Aux --
7333 ------------------------
7335 function Present_System_Aux (N : Node_Id := Empty) return Boolean is
7337 Aux_Name : Unit_Name_Type;
7338 Unum : Unit_Number_Type;
7343 function Find_System (C_Unit : Node_Id) return Entity_Id;
7344 -- Scan context clause of compilation unit to find with_clause
7351 function Find_System (C_Unit : Node_Id) return Entity_Id is
7352 With_Clause : Node_Id;
7355 With_Clause := First (Context_Items (C_Unit));
7356 while Present (With_Clause) loop
7357 if (Nkind (With_Clause) = N_With_Clause
7358 and then Chars (Name (With_Clause)) = Name_System)
7359 and then Comes_From_Source (With_Clause)
7370 -- Start of processing for Present_System_Aux
7373 -- The child unit may have been loaded and analyzed already
7375 if Present (System_Aux_Id) then
7378 -- If no previous pragma for System.Aux, nothing to load
7380 elsif No (System_Extend_Unit) then
7383 -- Use the unit name given in the pragma to retrieve the unit.
7384 -- Verify that System itself appears in the context clause of the
7385 -- current compilation. If System is not present, an error will
7386 -- have been reported already.
7389 With_Sys := Find_System (Cunit (Current_Sem_Unit));
7391 The_Unit := Unit (Cunit (Current_Sem_Unit));
7395 (Nkind (The_Unit) = N_Package_Body
7396 or else (Nkind (The_Unit) = N_Subprogram_Body
7398 not Acts_As_Spec (Cunit (Current_Sem_Unit))))
7400 With_Sys := Find_System (Library_Unit (Cunit (Current_Sem_Unit)));
7404 and then Present (N)
7406 -- If we are compiling a subunit, we need to examine its
7407 -- context as well (Current_Sem_Unit is the parent unit);
7409 The_Unit := Parent (N);
7410 while Nkind (The_Unit) /= N_Compilation_Unit loop
7411 The_Unit := Parent (The_Unit);
7414 if Nkind (Unit (The_Unit)) = N_Subunit then
7415 With_Sys := Find_System (The_Unit);
7419 if No (With_Sys) then
7423 Loc := Sloc (With_Sys);
7424 Get_Name_String (Chars (Expression (System_Extend_Unit)));
7425 Name_Buffer (8 .. Name_Len + 7) := Name_Buffer (1 .. Name_Len);
7426 Name_Buffer (1 .. 7) := "system.";
7427 Name_Buffer (Name_Len + 8) := '%';
7428 Name_Buffer (Name_Len + 9) := 's';
7429 Name_Len := Name_Len + 9;
7430 Aux_Name := Name_Find;
7434 (Load_Name => Aux_Name,
7437 Error_Node => With_Sys);
7439 if Unum /= No_Unit then
7440 Semantics (Cunit (Unum));
7442 Defining_Entity (Specification (Unit (Cunit (Unum))));
7445 Make_With_Clause (Loc,
7447 Make_Expanded_Name (Loc,
7448 Chars => Chars (System_Aux_Id),
7449 Prefix => New_Reference_To (Scope (System_Aux_Id), Loc),
7450 Selector_Name => New_Reference_To (System_Aux_Id, Loc)));
7452 Set_Entity (Name (Withn), System_Aux_Id);
7454 Set_Library_Unit (Withn, Cunit (Unum));
7455 Set_Corresponding_Spec (Withn, System_Aux_Id);
7456 Set_First_Name (Withn, True);
7457 Set_Implicit_With (Withn, True);
7459 Insert_After (With_Sys, Withn);
7460 Mark_Rewrite_Insertion (Withn);
7461 Set_Context_Installed (Withn);
7465 -- Here if unit load failed
7468 Error_Msg_Name_1 := Name_System;
7469 Error_Msg_Name_2 := Chars (Expression (System_Extend_Unit));
7471 ("extension package `%.%` does not exist",
7472 Opt.System_Extend_Unit);
7476 end Present_System_Aux;
7478 -------------------------
7479 -- Restore_Scope_Stack --
7480 -------------------------
7482 procedure Restore_Scope_Stack (Handle_Use : Boolean := True) is
7485 Comp_Unit : Node_Id;
7486 In_Child : Boolean := False;
7487 Full_Vis : Boolean := True;
7488 SS_Last : constant Int := Scope_Stack.Last;
7491 -- Restore visibility of previous scope stack, if any
7493 for J in reverse 0 .. Scope_Stack.Last loop
7494 exit when Scope_Stack.Table (J).Entity = Standard_Standard
7495 or else No (Scope_Stack.Table (J).Entity);
7497 S := Scope_Stack.Table (J).Entity;
7499 if not Is_Hidden_Open_Scope (S) then
7501 -- If the parent scope is hidden, its entities are hidden as
7502 -- well, unless the entity is the instantiation currently
7505 if not Is_Hidden_Open_Scope (Scope (S))
7506 or else not Analyzed (Parent (S))
7507 or else Scope (S) = Standard_Standard
7509 Set_Is_Immediately_Visible (S, True);
7512 E := First_Entity (S);
7513 while Present (E) loop
7514 if Is_Child_Unit (E) then
7515 if not From_With_Type (E) then
7516 Set_Is_Immediately_Visible (E,
7517 Is_Visible_Child_Unit (E) or else In_Open_Scopes (E));
7521 (Nkind (Parent (E)) = N_Defining_Program_Unit_Name
7523 Nkind (Parent (Parent (E))) = N_Package_Specification);
7524 Set_Is_Immediately_Visible (E,
7525 Limited_View_Installed (Parent (Parent (E))));
7528 Set_Is_Immediately_Visible (E, True);
7534 and then Is_Package_Or_Generic_Package (S)
7536 -- We are in the visible part of the package scope
7538 exit when E = First_Private_Entity (S);
7542 -- The visibility of child units (siblings of current compilation)
7543 -- must be restored in any case. Their declarations may appear
7544 -- after the private part of the parent.
7546 if not Full_Vis then
7547 while Present (E) loop
7548 if Is_Child_Unit (E) then
7549 Set_Is_Immediately_Visible (E,
7550 Is_Visible_Child_Unit (E) or else In_Open_Scopes (E));
7558 if Is_Child_Unit (S)
7559 and not In_Child -- check only for current unit
7563 -- Restore visibility of parents according to whether the child
7564 -- is private and whether we are in its visible part.
7566 Comp_Unit := Parent (Unit_Declaration_Node (S));
7568 if Nkind (Comp_Unit) = N_Compilation_Unit
7569 and then Private_Present (Comp_Unit)
7573 elsif Is_Package_Or_Generic_Package (S)
7574 and then (In_Private_Part (S) or else In_Package_Body (S))
7578 -- if S is the scope of some instance (which has already been
7579 -- seen on the stack) it does not affect the visibility of
7582 elsif Is_Hidden_Open_Scope (S) then
7585 elsif (Ekind (S) = E_Procedure
7586 or else Ekind (S) = E_Function)
7587 and then Has_Completion (S)
7598 if SS_Last >= Scope_Stack.First
7599 and then Scope_Stack.Table (SS_Last).Entity /= Standard_Standard
7602 Install_Use_Clauses (Scope_Stack.Table (SS_Last).First_Use_Clause);
7604 end Restore_Scope_Stack;
7606 ----------------------
7607 -- Save_Scope_Stack --
7608 ----------------------
7610 procedure Save_Scope_Stack (Handle_Use : Boolean := True) is
7613 SS_Last : constant Int := Scope_Stack.Last;
7616 if SS_Last >= Scope_Stack.First
7617 and then Scope_Stack.Table (SS_Last).Entity /= Standard_Standard
7620 End_Use_Clauses (Scope_Stack.Table (SS_Last).First_Use_Clause);
7623 -- If the call is from within a compilation unit, as when called from
7624 -- Rtsfind, make current entries in scope stack invisible while we
7625 -- analyze the new unit.
7627 for J in reverse 0 .. SS_Last loop
7628 exit when Scope_Stack.Table (J).Entity = Standard_Standard
7629 or else No (Scope_Stack.Table (J).Entity);
7631 S := Scope_Stack.Table (J).Entity;
7632 Set_Is_Immediately_Visible (S, False);
7634 E := First_Entity (S);
7635 while Present (E) loop
7636 Set_Is_Immediately_Visible (E, False);
7642 end Save_Scope_Stack;
7648 procedure Set_Use (L : List_Id) is
7650 Pack_Name : Node_Id;
7657 while Present (Decl) loop
7658 if Nkind (Decl) = N_Use_Package_Clause then
7659 Chain_Use_Clause (Decl);
7661 Pack_Name := First (Names (Decl));
7662 while Present (Pack_Name) loop
7663 Pack := Entity (Pack_Name);
7665 if Ekind (Pack) = E_Package
7666 and then Applicable_Use (Pack_Name)
7668 Use_One_Package (Pack, Decl);
7674 elsif Nkind (Decl) = N_Use_Type_Clause then
7675 Chain_Use_Clause (Decl);
7677 Id := First (Subtype_Marks (Decl));
7678 while Present (Id) loop
7679 if Entity (Id) /= Any_Type then
7692 ---------------------
7693 -- Use_One_Package --
7694 ---------------------
7696 procedure Use_One_Package (P : Entity_Id; N : Node_Id) is
7699 Current_Instance : Entity_Id := Empty;
7701 Private_With_OK : Boolean := False;
7704 if Ekind (P) /= E_Package then
7709 Set_Current_Use_Clause (P, N);
7711 -- Ada 2005 (AI-50217): Check restriction
7713 if From_With_Type (P) then
7714 Error_Msg_N ("limited withed package cannot appear in use clause", N);
7717 -- Find enclosing instance, if any
7720 Current_Instance := Current_Scope;
7721 while not Is_Generic_Instance (Current_Instance) loop
7722 Current_Instance := Scope (Current_Instance);
7725 if No (Hidden_By_Use_Clause (N)) then
7726 Set_Hidden_By_Use_Clause (N, New_Elmt_List);
7730 -- If unit is a package renaming, indicate that the renamed
7731 -- package is also in use (the flags on both entities must
7732 -- remain consistent, and a subsequent use of either of them
7733 -- should be recognized as redundant).
7735 if Present (Renamed_Object (P)) then
7736 Set_In_Use (Renamed_Object (P));
7737 Set_Current_Use_Clause (Renamed_Object (P), N);
7738 Real_P := Renamed_Object (P);
7743 -- Ada 2005 (AI-262): Check the use_clause of a private withed package
7744 -- found in the private part of a package specification
7746 if In_Private_Part (Current_Scope)
7747 and then Has_Private_With (P)
7748 and then Is_Child_Unit (Current_Scope)
7749 and then Is_Child_Unit (P)
7750 and then Is_Ancestor_Package (Scope (Current_Scope), P)
7752 Private_With_OK := True;
7755 -- Loop through entities in one package making them potentially
7758 Id := First_Entity (P);
7760 and then (Id /= First_Private_Entity (P)
7761 or else Private_With_OK) -- Ada 2005 (AI-262)
7763 Prev := Current_Entity (Id);
7764 while Present (Prev) loop
7765 if Is_Immediately_Visible (Prev)
7766 and then (not Is_Overloadable (Prev)
7767 or else not Is_Overloadable (Id)
7768 or else (Type_Conformant (Id, Prev)))
7770 if No (Current_Instance) then
7772 -- Potentially use-visible entity remains hidden
7774 goto Next_Usable_Entity;
7776 -- A use clause within an instance hides outer global entities,
7777 -- which are not used to resolve local entities in the
7778 -- instance. Note that the predefined entities in Standard
7779 -- could not have been hidden in the generic by a use clause,
7780 -- and therefore remain visible. Other compilation units whose
7781 -- entities appear in Standard must be hidden in an instance.
7783 -- To determine whether an entity is external to the instance
7784 -- we compare the scope depth of its scope with that of the
7785 -- current instance. However, a generic actual of a subprogram
7786 -- instance is declared in the wrapper package but will not be
7787 -- hidden by a use-visible entity. similarly, an entity that is
7788 -- declared in an enclosing instance will not be hidden by an
7789 -- an entity declared in a generic actual, which can only have
7790 -- been use-visible in the generic and will not have hidden the
7791 -- entity in the generic parent.
7793 -- If Id is called Standard, the predefined package with the
7794 -- same name is in the homonym chain. It has to be ignored
7795 -- because it has no defined scope (being the only entity in
7796 -- the system with this mandated behavior).
7798 elsif not Is_Hidden (Id)
7799 and then Present (Scope (Prev))
7800 and then not Is_Wrapper_Package (Scope (Prev))
7801 and then Scope_Depth (Scope (Prev)) <
7802 Scope_Depth (Current_Instance)
7803 and then (Scope (Prev) /= Standard_Standard
7804 or else Sloc (Prev) > Standard_Location)
7806 if In_Open_Scopes (Scope (Prev))
7807 and then Is_Generic_Instance (Scope (Prev))
7808 and then Present (Associated_Formal_Package (P))
7813 Set_Is_Potentially_Use_Visible (Id);
7814 Set_Is_Immediately_Visible (Prev, False);
7815 Append_Elmt (Prev, Hidden_By_Use_Clause (N));
7819 -- A user-defined operator is not use-visible if the predefined
7820 -- operator for the type is immediately visible, which is the case
7821 -- if the type of the operand is in an open scope. This does not
7822 -- apply to user-defined operators that have operands of different
7823 -- types, because the predefined mixed mode operations (multiply
7824 -- and divide) apply to universal types and do not hide anything.
7826 elsif Ekind (Prev) = E_Operator
7827 and then Operator_Matches_Spec (Prev, Id)
7828 and then In_Open_Scopes
7829 (Scope (Base_Type (Etype (First_Formal (Id)))))
7830 and then (No (Next_Formal (First_Formal (Id)))
7831 or else Etype (First_Formal (Id))
7832 = Etype (Next_Formal (First_Formal (Id)))
7833 or else Chars (Prev) = Name_Op_Expon)
7835 goto Next_Usable_Entity;
7837 -- In an instance, two homonyms may become use_visible through the
7838 -- actuals of distinct formal packages. In the generic, only the
7839 -- current one would have been visible, so make the other one
7842 elsif Present (Current_Instance)
7843 and then Is_Potentially_Use_Visible (Prev)
7844 and then not Is_Overloadable (Prev)
7845 and then Scope (Id) /= Scope (Prev)
7846 and then Used_As_Generic_Actual (Scope (Prev))
7847 and then Used_As_Generic_Actual (Scope (Id))
7848 and then not In_Same_List (Current_Use_Clause (Scope (Prev)),
7849 Current_Use_Clause (Scope (Id)))
7851 Set_Is_Potentially_Use_Visible (Prev, False);
7852 Append_Elmt (Prev, Hidden_By_Use_Clause (N));
7855 Prev := Homonym (Prev);
7858 -- On exit, we know entity is not hidden, unless it is private
7860 if not Is_Hidden (Id)
7861 and then ((not Is_Child_Unit (Id))
7862 or else Is_Visible_Child_Unit (Id))
7864 Set_Is_Potentially_Use_Visible (Id);
7866 if Is_Private_Type (Id)
7867 and then Present (Full_View (Id))
7869 Set_Is_Potentially_Use_Visible (Full_View (Id));
7873 <<Next_Usable_Entity>>
7877 -- Child units are also made use-visible by a use clause, but they may
7878 -- appear after all visible declarations in the parent entity list.
7880 while Present (Id) loop
7881 if Is_Child_Unit (Id)
7882 and then Is_Visible_Child_Unit (Id)
7884 Set_Is_Potentially_Use_Visible (Id);
7890 if Chars (Real_P) = Name_System
7891 and then Scope (Real_P) = Standard_Standard
7892 and then Present_System_Aux (N)
7894 Use_One_Package (System_Aux_Id, N);
7897 end Use_One_Package;
7903 procedure Use_One_Type (Id : Node_Id; Installed : Boolean := False) is
7905 Is_Known_Used : Boolean;
7909 function Spec_Reloaded_For_Body return Boolean;
7910 -- Determine whether the compilation unit is a package body and the use
7911 -- type clause is in the spec of the same package. Even though the spec
7912 -- was analyzed first, its context is reloaded when analysing the body.
7914 procedure Use_Class_Wide_Operations (Typ : Entity_Id);
7915 -- AI05-150: if the use_type_clause carries the "all" qualifier,
7916 -- class-wide operations of ancestor types are use-visible if the
7917 -- ancestor type is visible.
7919 ----------------------------
7920 -- Spec_Reloaded_For_Body --
7921 ----------------------------
7923 function Spec_Reloaded_For_Body return Boolean is
7925 if Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Body then
7927 Spec : constant Node_Id :=
7928 Parent (List_Containing (Parent (Id)));
7931 Nkind (Spec) = N_Package_Specification
7932 and then Corresponding_Body (Parent (Spec)) =
7933 Cunit_Entity (Current_Sem_Unit);
7938 end Spec_Reloaded_For_Body;
7940 -------------------------------
7941 -- Use_Class_Wide_Operations --
7942 -------------------------------
7944 procedure Use_Class_Wide_Operations (Typ : Entity_Id) is
7948 function Is_Class_Wide_Operation_Of
7950 T : Entity_Id) return Boolean;
7951 -- Determine whether a subprogram has a class-wide parameter or
7952 -- result that is T'Class.
7954 ---------------------------------
7955 -- Is_Class_Wide_Operation_Of --
7956 ---------------------------------
7958 function Is_Class_Wide_Operation_Of
7960 T : Entity_Id) return Boolean
7965 Formal := First_Formal (Op);
7966 while Present (Formal) loop
7967 if Etype (Formal) = Class_Wide_Type (T) then
7970 Next_Formal (Formal);
7973 if Etype (Op) = Class_Wide_Type (T) then
7978 end Is_Class_Wide_Operation_Of;
7980 -- Start of processing for Use_Class_Wide_Operations
7983 Scop := Scope (Typ);
7984 if not Is_Hidden (Scop) then
7985 Ent := First_Entity (Scop);
7986 while Present (Ent) loop
7987 if Is_Overloadable (Ent)
7988 and then Is_Class_Wide_Operation_Of (Ent, Typ)
7989 and then not Is_Potentially_Use_Visible (Ent)
7991 Set_Is_Potentially_Use_Visible (Ent);
7992 Append_Elmt (Ent, Used_Operations (Parent (Id)));
7999 if Is_Derived_Type (Typ) then
8000 Use_Class_Wide_Operations (Etype (Base_Type (Typ)));
8002 end Use_Class_Wide_Operations;
8004 -- Start of processing for Use_One_Type;
8007 -- It is the type determined by the subtype mark (8.4(8)) whose
8008 -- operations become potentially use-visible.
8010 T := Base_Type (Entity (Id));
8012 -- Either the type itself is used, the package where it is declared
8013 -- is in use or the entity is declared in the current package, thus
8018 or else In_Use (Scope (T))
8019 or else Scope (T) = Current_Scope;
8021 Set_Redundant_Use (Id,
8022 Is_Known_Used or else Is_Potentially_Use_Visible (T));
8024 if Ekind (T) = E_Incomplete_Type then
8025 Error_Msg_N ("premature usage of incomplete type", Id);
8027 elsif In_Open_Scopes (Scope (T)) then
8030 -- A limited view cannot appear in a use_type clause. However, an access
8031 -- type whose designated type is limited has the flag but is not itself
8032 -- a limited view unless we only have a limited view of its enclosing
8035 elsif From_With_Type (T)
8036 and then From_With_Type (Scope (T))
8039 ("incomplete type from limited view "
8040 & "cannot appear in use clause", Id);
8042 -- If the subtype mark designates a subtype in a different package,
8043 -- we have to check that the parent type is visible, otherwise the
8044 -- use type clause is a noop. Not clear how to do that???
8046 elsif not Redundant_Use (Id) then
8049 -- If T is tagged, primitive operators on class-wide operands
8050 -- are also available.
8052 if Is_Tagged_Type (T) then
8053 Set_In_Use (Class_Wide_Type (T));
8056 Set_Current_Use_Clause (T, Parent (Id));
8058 -- Iterate over primitive operations of the type. If an operation is
8059 -- already use_visible, it is the result of a previous use_clause,
8060 -- and already appears on the corresponding entity chain. If the
8061 -- clause is being reinstalled, operations are already use-visible.
8067 Op_List := Collect_Primitive_Operations (T);
8068 Elmt := First_Elmt (Op_List);
8069 while Present (Elmt) loop
8070 if (Nkind (Node (Elmt)) = N_Defining_Operator_Symbol
8071 or else Chars (Node (Elmt)) in Any_Operator_Name)
8072 and then not Is_Hidden (Node (Elmt))
8073 and then not Is_Potentially_Use_Visible (Node (Elmt))
8075 Set_Is_Potentially_Use_Visible (Node (Elmt));
8076 Append_Elmt (Node (Elmt), Used_Operations (Parent (Id)));
8078 elsif Ada_Version >= Ada_2012
8079 and then All_Present (Parent (Id))
8080 and then not Is_Hidden (Node (Elmt))
8081 and then not Is_Potentially_Use_Visible (Node (Elmt))
8083 Set_Is_Potentially_Use_Visible (Node (Elmt));
8084 Append_Elmt (Node (Elmt), Used_Operations (Parent (Id)));
8091 if Ada_Version >= Ada_2012
8092 and then All_Present (Parent (Id))
8093 and then Is_Tagged_Type (T)
8095 Use_Class_Wide_Operations (T);
8099 -- If warning on redundant constructs, check for unnecessary WITH
8101 if Warn_On_Redundant_Constructs
8102 and then Is_Known_Used
8104 -- with P; with P; use P;
8105 -- package P is package X is package body X is
8106 -- type T ... use P.T;
8108 -- The compilation unit is the body of X. GNAT first compiles the
8109 -- spec of X, then proceeds to the body. At that point P is marked
8110 -- as use visible. The analysis then reinstalls the spec along with
8111 -- its context. The use clause P.T is now recognized as redundant,
8112 -- but in the wrong context. Do not emit a warning in such cases.
8113 -- Do not emit a warning either if we are in an instance, there is
8114 -- no redundancy between an outer use_clause and one that appears
8115 -- within the generic.
8117 and then not Spec_Reloaded_For_Body
8118 and then not In_Instance
8120 -- The type already has a use clause
8124 -- Case where we know the current use clause for the type
8126 if Present (Current_Use_Clause (T)) then
8127 Use_Clause_Known : declare
8128 Clause1 : constant Node_Id := Parent (Id);
8129 Clause2 : constant Node_Id := Current_Use_Clause (T);
8136 function Entity_Of_Unit (U : Node_Id) return Entity_Id;
8137 -- Return the appropriate entity for determining which unit
8138 -- has a deeper scope: the defining entity for U, unless U
8139 -- is a package instance, in which case we retrieve the
8140 -- entity of the instance spec.
8142 --------------------
8143 -- Entity_Of_Unit --
8144 --------------------
8146 function Entity_Of_Unit (U : Node_Id) return Entity_Id is
8148 if Nkind (U) = N_Package_Instantiation
8149 and then Analyzed (U)
8151 return Defining_Entity (Instance_Spec (U));
8153 return Defining_Entity (U);
8157 -- Start of processing for Use_Clause_Known
8160 -- If both current use type clause and the use type clause
8161 -- for the type are at the compilation unit level, one of
8162 -- the units must be an ancestor of the other, and the
8163 -- warning belongs on the descendant.
8165 if Nkind (Parent (Clause1)) = N_Compilation_Unit
8167 Nkind (Parent (Clause2)) = N_Compilation_Unit
8170 -- If the unit is a subprogram body that acts as spec,
8171 -- the context clause is shared with the constructed
8172 -- subprogram spec. Clearly there is no redundancy.
8174 if Clause1 = Clause2 then
8178 Unit1 := Unit (Parent (Clause1));
8179 Unit2 := Unit (Parent (Clause2));
8181 -- If both clauses are on same unit, or one is the body
8182 -- of the other, or one of them is in a subunit, report
8183 -- redundancy on the later one.
8185 if Unit1 = Unit2 then
8186 Error_Msg_Sloc := Sloc (Current_Use_Clause (T));
8187 Error_Msg_NE -- CODEFIX
8188 ("& is already use-visible through previous "
8189 & "use_type_clause #?", Clause1, T);
8192 elsif Nkind (Unit1) = N_Subunit then
8193 Error_Msg_Sloc := Sloc (Current_Use_Clause (T));
8194 Error_Msg_NE -- CODEFIX
8195 ("& is already use-visible through previous "
8196 & "use_type_clause #?", Clause1, T);
8199 elsif Nkind_In (Unit2, N_Package_Body, N_Subprogram_Body)
8200 and then Nkind (Unit1) /= Nkind (Unit2)
8201 and then Nkind (Unit1) /= N_Subunit
8203 Error_Msg_Sloc := Sloc (Clause1);
8204 Error_Msg_NE -- CODEFIX
8205 ("& is already use-visible through previous "
8206 & "use_type_clause #?", Current_Use_Clause (T), T);
8210 -- There is a redundant use type clause in a child unit.
8211 -- Determine which of the units is more deeply nested.
8212 -- If a unit is a package instance, retrieve the entity
8213 -- and its scope from the instance spec.
8215 Ent1 := Entity_Of_Unit (Unit1);
8216 Ent2 := Entity_Of_Unit (Unit2);
8218 if Scope (Ent2) = Standard_Standard then
8219 Error_Msg_Sloc := Sloc (Current_Use_Clause (T));
8222 elsif Scope (Ent1) = Standard_Standard then
8223 Error_Msg_Sloc := Sloc (Id);
8226 -- If both units are child units, we determine which one
8227 -- is the descendant by the scope distance to the
8228 -- ultimate parent unit.
8238 and then Present (S2)
8239 and then S1 /= Standard_Standard
8240 and then S2 /= Standard_Standard
8246 if S1 = Standard_Standard then
8247 Error_Msg_Sloc := Sloc (Id);
8250 Error_Msg_Sloc := Sloc (Current_Use_Clause (T));
8256 Error_Msg_NE -- CODEFIX
8257 ("& is already use-visible through previous "
8258 & "use_type_clause #?", Err_No, Id);
8260 -- Case where current use type clause and the use type
8261 -- clause for the type are not both at the compilation unit
8262 -- level. In this case we don't have location information.
8265 Error_Msg_NE -- CODEFIX
8266 ("& is already use-visible through previous "
8267 & "use type clause?", Id, T);
8269 end Use_Clause_Known;
8271 -- Here if Current_Use_Clause is not set for T, another case
8272 -- where we do not have the location information available.
8275 Error_Msg_NE -- CODEFIX
8276 ("& is already use-visible through previous "
8277 & "use type clause?", Id, T);
8280 -- The package where T is declared is already used
8282 elsif In_Use (Scope (T)) then
8283 Error_Msg_Sloc := Sloc (Current_Use_Clause (Scope (T)));
8284 Error_Msg_NE -- CODEFIX
8285 ("& is already use-visible through package use clause #?",
8288 -- The current scope is the package where T is declared
8291 Error_Msg_Node_2 := Scope (T);
8292 Error_Msg_NE -- CODEFIX
8293 ("& is already use-visible inside package &?", Id, T);
8302 procedure Write_Info is
8303 Id : Entity_Id := First_Entity (Current_Scope);
8306 -- No point in dumping standard entities
8308 if Current_Scope = Standard_Standard then
8312 Write_Str ("========================================================");
8314 Write_Str (" Defined Entities in ");
8315 Write_Name (Chars (Current_Scope));
8317 Write_Str ("========================================================");
8321 Write_Str ("-- none --");
8325 while Present (Id) loop
8326 Write_Entity_Info (Id, " ");
8331 if Scope (Current_Scope) = Standard_Standard then
8333 -- Print information on the current unit itself
8335 Write_Entity_Info (Current_Scope, " ");
8348 for J in reverse 1 .. Scope_Stack.Last loop
8349 S := Scope_Stack.Table (J).Entity;
8350 Write_Int (Int (S));
8351 Write_Str (" === ");
8352 Write_Name (Chars (S));
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