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);
1140 Init_Object_Size_Align (Id);
1142 if T = Any_Type or else Etype (Nam) = Any_Type then
1145 -- Verify that the renamed entity is an object or a function call. It
1146 -- may have been rewritten in several ways.
1148 elsif Is_Object_Reference (Nam) then
1149 if Comes_From_Source (N)
1150 and then Is_Dependent_Component_Of_Mutable_Object (Nam)
1153 ("illegal renaming of discriminant-dependent component", Nam);
1156 -- A static function call may have been folded into a literal
1158 elsif Nkind (Original_Node (Nam)) = N_Function_Call
1160 -- When expansion is disabled, attribute reference is not
1161 -- rewritten as function call. Otherwise it may be rewritten
1162 -- as a conversion, so check original node.
1164 or else (Nkind (Original_Node (Nam)) = N_Attribute_Reference
1165 and then Is_Function_Attribute_Name
1166 (Attribute_Name (Original_Node (Nam))))
1168 -- Weird but legal, equivalent to renaming a function call.
1169 -- Illegal if the literal is the result of constant-folding an
1170 -- attribute reference that is not a function.
1172 or else (Is_Entity_Name (Nam)
1173 and then Ekind (Entity (Nam)) = E_Enumeration_Literal
1175 Nkind (Original_Node (Nam)) /= N_Attribute_Reference)
1177 or else (Nkind (Nam) = N_Type_Conversion
1178 and then Is_Tagged_Type (Entity (Subtype_Mark (Nam))))
1182 elsif Nkind (Nam) = N_Type_Conversion then
1184 ("renaming of conversion only allowed for tagged types", Nam);
1186 -- Ada 2005 (AI-327)
1188 elsif Ada_Version >= Ada_2005
1189 and then Nkind (Nam) = N_Attribute_Reference
1190 and then Attribute_Name (Nam) = Name_Priority
1194 -- Allow internally generated x'Reference expression
1196 elsif Nkind (Nam) = N_Reference then
1200 Error_Msg_N ("expect object name in renaming", Nam);
1205 if not Is_Variable (Nam) then
1206 Set_Ekind (Id, E_Constant);
1207 Set_Never_Set_In_Source (Id, True);
1208 Set_Is_True_Constant (Id, True);
1211 Set_Renamed_Object (Id, Nam);
1212 end Analyze_Object_Renaming;
1214 ------------------------------
1215 -- Analyze_Package_Renaming --
1216 ------------------------------
1218 procedure Analyze_Package_Renaming (N : Node_Id) is
1219 New_P : constant Entity_Id := Defining_Entity (N);
1224 if Name (N) = Error then
1228 -- Apply Text_IO kludge here since we may be renaming a child of Text_IO
1230 Text_IO_Kludge (Name (N));
1232 if Current_Scope /= Standard_Standard then
1233 Set_Is_Pure (New_P, Is_Pure (Current_Scope));
1239 if Is_Entity_Name (Name (N)) then
1240 Old_P := Entity (Name (N));
1245 if Etype (Old_P) = Any_Type then
1246 Error_Msg_N ("expect package name in renaming", Name (N));
1248 elsif Ekind (Old_P) /= E_Package
1249 and then not (Ekind (Old_P) = E_Generic_Package
1250 and then In_Open_Scopes (Old_P))
1252 if Ekind (Old_P) = E_Generic_Package then
1254 ("generic package cannot be renamed as a package", Name (N));
1256 Error_Msg_Sloc := Sloc (Old_P);
1258 ("expect package name in renaming, found& declared#",
1262 -- Set basic attributes to minimize cascaded errors
1264 Set_Ekind (New_P, E_Package);
1265 Set_Etype (New_P, Standard_Void_Type);
1267 -- Here for OK package renaming
1270 -- Entities in the old package are accessible through the renaming
1271 -- entity. The simplest implementation is to have both packages share
1274 Set_Ekind (New_P, E_Package);
1275 Set_Etype (New_P, Standard_Void_Type);
1277 if Present (Renamed_Object (Old_P)) then
1278 Set_Renamed_Object (New_P, Renamed_Object (Old_P));
1280 Set_Renamed_Object (New_P, Old_P);
1283 Set_Has_Completion (New_P);
1285 Set_First_Entity (New_P, First_Entity (Old_P));
1286 Set_Last_Entity (New_P, Last_Entity (Old_P));
1287 Set_First_Private_Entity (New_P, First_Private_Entity (Old_P));
1288 Check_Library_Unit_Renaming (N, Old_P);
1289 Generate_Reference (Old_P, Name (N));
1291 -- If the renaming is in the visible part of a package, then we set
1292 -- Renamed_In_Spec for the renamed package, to prevent giving
1293 -- warnings about no entities referenced. Such a warning would be
1294 -- overenthusiastic, since clients can see entities in the renamed
1295 -- package via the visible package renaming.
1298 Ent : constant Entity_Id := Cunit_Entity (Current_Sem_Unit);
1300 if Ekind (Ent) = E_Package
1301 and then not In_Private_Part (Ent)
1302 and then In_Extended_Main_Source_Unit (N)
1303 and then Ekind (Old_P) = E_Package
1305 Set_Renamed_In_Spec (Old_P);
1309 -- If this is the renaming declaration of a package instantiation
1310 -- within itself, it is the declaration that ends the list of actuals
1311 -- for the instantiation. At this point, the subtypes that rename
1312 -- the actuals are flagged as generic, to avoid spurious ambiguities
1313 -- if the actuals for two distinct formals happen to coincide. If
1314 -- the actual is a private type, the subtype has a private completion
1315 -- that is flagged in the same fashion.
1317 -- Resolution is identical to what is was in the original generic.
1318 -- On exit from the generic instance, these are turned into regular
1319 -- subtypes again, so they are compatible with types in their class.
1321 if not Is_Generic_Instance (Old_P) then
1324 Spec := Specification (Unit_Declaration_Node (Old_P));
1327 if Nkind (Spec) = N_Package_Specification
1328 and then Present (Generic_Parent (Spec))
1329 and then Old_P = Current_Scope
1330 and then Chars (New_P) = Chars (Generic_Parent (Spec))
1336 E := First_Entity (Old_P);
1341 and then Nkind (Parent (E)) = N_Subtype_Declaration
1343 Set_Is_Generic_Actual_Type (E);
1345 if Is_Private_Type (E)
1346 and then Present (Full_View (E))
1348 Set_Is_Generic_Actual_Type (Full_View (E));
1357 end Analyze_Package_Renaming;
1359 -------------------------------
1360 -- Analyze_Renamed_Character --
1361 -------------------------------
1363 procedure Analyze_Renamed_Character
1368 C : constant Node_Id := Name (N);
1371 if Ekind (New_S) = E_Function then
1372 Resolve (C, Etype (New_S));
1375 Check_Frozen_Renaming (N, New_S);
1379 Error_Msg_N ("character literal can only be renamed as function", N);
1381 end Analyze_Renamed_Character;
1383 ---------------------------------
1384 -- Analyze_Renamed_Dereference --
1385 ---------------------------------
1387 procedure Analyze_Renamed_Dereference
1392 Nam : constant Node_Id := Name (N);
1393 P : constant Node_Id := Prefix (Nam);
1399 if not Is_Overloaded (P) then
1400 if Ekind (Etype (Nam)) /= E_Subprogram_Type
1401 or else not Type_Conformant (Etype (Nam), New_S)
1403 Error_Msg_N ("designated type does not match specification", P);
1412 Get_First_Interp (Nam, Ind, It);
1414 while Present (It.Nam) loop
1416 if Ekind (It.Nam) = E_Subprogram_Type
1417 and then Type_Conformant (It.Nam, New_S)
1419 if Typ /= Any_Id then
1420 Error_Msg_N ("ambiguous renaming", P);
1427 Get_Next_Interp (Ind, It);
1430 if Typ = Any_Type then
1431 Error_Msg_N ("designated type does not match specification", P);
1436 Check_Frozen_Renaming (N, New_S);
1440 end Analyze_Renamed_Dereference;
1442 ---------------------------
1443 -- Analyze_Renamed_Entry --
1444 ---------------------------
1446 procedure Analyze_Renamed_Entry
1451 Nam : constant Node_Id := Name (N);
1452 Sel : constant Node_Id := Selector_Name (Nam);
1456 if Entity (Sel) = Any_Id then
1458 -- Selector is undefined on prefix. Error emitted already
1460 Set_Has_Completion (New_S);
1464 -- Otherwise find renamed entity and build body of New_S as a call to it
1466 Old_S := Find_Renamed_Entity (N, Selector_Name (Nam), New_S);
1468 if Old_S = Any_Id then
1469 Error_Msg_N (" no subprogram or entry matches specification", N);
1472 Check_Subtype_Conformant (New_S, Old_S, N);
1473 Generate_Reference (New_S, Defining_Entity (N), 'b');
1474 Style.Check_Identifier (Defining_Entity (N), New_S);
1477 -- Only mode conformance required for a renaming_as_declaration
1479 Check_Mode_Conformant (New_S, Old_S, N);
1482 Inherit_Renamed_Profile (New_S, Old_S);
1484 -- The prefix can be an arbitrary expression that yields a task type,
1485 -- so it must be resolved.
1487 Resolve (Prefix (Nam), Scope (Old_S));
1490 Set_Convention (New_S, Convention (Old_S));
1491 Set_Has_Completion (New_S, Inside_A_Generic);
1494 Check_Frozen_Renaming (N, New_S);
1496 end Analyze_Renamed_Entry;
1498 -----------------------------------
1499 -- Analyze_Renamed_Family_Member --
1500 -----------------------------------
1502 procedure Analyze_Renamed_Family_Member
1507 Nam : constant Node_Id := Name (N);
1508 P : constant Node_Id := Prefix (Nam);
1512 if (Is_Entity_Name (P) and then Ekind (Entity (P)) = E_Entry_Family)
1513 or else (Nkind (P) = N_Selected_Component
1515 Ekind (Entity (Selector_Name (P))) = E_Entry_Family)
1517 if Is_Entity_Name (P) then
1518 Old_S := Entity (P);
1520 Old_S := Entity (Selector_Name (P));
1523 if not Entity_Matches_Spec (Old_S, New_S) then
1524 Error_Msg_N ("entry family does not match specification", N);
1527 Check_Subtype_Conformant (New_S, Old_S, N);
1528 Generate_Reference (New_S, Defining_Entity (N), 'b');
1529 Style.Check_Identifier (Defining_Entity (N), New_S);
1533 Error_Msg_N ("no entry family matches specification", N);
1536 Set_Has_Completion (New_S, Inside_A_Generic);
1539 Check_Frozen_Renaming (N, New_S);
1541 end Analyze_Renamed_Family_Member;
1543 -----------------------------------------
1544 -- Analyze_Renamed_Primitive_Operation --
1545 -----------------------------------------
1547 procedure Analyze_Renamed_Primitive_Operation
1556 Ctyp : Conformance_Type) return Boolean;
1557 -- Verify that the signatures of the renamed entity and the new entity
1558 -- match. The first formal of the renamed entity is skipped because it
1559 -- is the target object in any subsequent call.
1563 Ctyp : Conformance_Type) return Boolean
1569 if Ekind (Subp) /= Ekind (New_S) then
1573 Old_F := Next_Formal (First_Formal (Subp));
1574 New_F := First_Formal (New_S);
1575 while Present (Old_F) and then Present (New_F) loop
1576 if not Conforming_Types (Etype (Old_F), Etype (New_F), Ctyp) then
1580 if Ctyp >= Mode_Conformant
1581 and then Ekind (Old_F) /= Ekind (New_F)
1586 Next_Formal (New_F);
1587 Next_Formal (Old_F);
1594 if not Is_Overloaded (Selector_Name (Name (N))) then
1595 Old_S := Entity (Selector_Name (Name (N)));
1597 if not Conforms (Old_S, Type_Conformant) then
1602 -- Find the operation that matches the given signature
1610 Get_First_Interp (Selector_Name (Name (N)), Ind, It);
1612 while Present (It.Nam) loop
1613 if Conforms (It.Nam, Type_Conformant) then
1617 Get_Next_Interp (Ind, It);
1622 if Old_S = Any_Id then
1623 Error_Msg_N (" no subprogram or entry matches specification", N);
1627 if not Conforms (Old_S, Subtype_Conformant) then
1628 Error_Msg_N ("subtype conformance error in renaming", N);
1631 Generate_Reference (New_S, Defining_Entity (N), 'b');
1632 Style.Check_Identifier (Defining_Entity (N), New_S);
1635 -- Only mode conformance required for a renaming_as_declaration
1637 if not Conforms (Old_S, Mode_Conformant) then
1638 Error_Msg_N ("mode conformance error in renaming", N);
1642 -- Inherit_Renamed_Profile (New_S, Old_S);
1644 -- The prefix can be an arbitrary expression that yields an
1645 -- object, so it must be resolved.
1647 Resolve (Prefix (Name (N)));
1649 end Analyze_Renamed_Primitive_Operation;
1651 ---------------------------------
1652 -- Analyze_Subprogram_Renaming --
1653 ---------------------------------
1655 procedure Analyze_Subprogram_Renaming (N : Node_Id) is
1656 Formal_Spec : constant Node_Id := Corresponding_Formal_Spec (N);
1657 Is_Actual : constant Boolean := Present (Formal_Spec);
1658 Inst_Node : Node_Id := Empty;
1659 Nam : constant Node_Id := Name (N);
1661 Old_S : Entity_Id := Empty;
1662 Rename_Spec : Entity_Id;
1663 Save_AV : constant Ada_Version_Type := Ada_Version;
1664 Save_AV_Exp : constant Ada_Version_Type := Ada_Version_Explicit;
1665 Spec : constant Node_Id := Specification (N);
1667 procedure Check_Null_Exclusion
1670 -- Ada 2005 (AI-423): Given renaming Ren of subprogram Sub, check the
1671 -- following AI rules:
1673 -- If Ren is a renaming of a formal subprogram and one of its
1674 -- parameters has a null exclusion, then the corresponding formal
1675 -- in Sub must also have one. Otherwise the subtype of the Sub's
1676 -- formal parameter must exclude null.
1678 -- If Ren is a renaming of a formal function and its return
1679 -- profile has a null exclusion, then Sub's return profile must
1680 -- have one. Otherwise the subtype of Sub's return profile must
1683 function Original_Subprogram (Subp : Entity_Id) return Entity_Id;
1684 -- Find renamed entity when the declaration is a renaming_as_body and
1685 -- the renamed entity may itself be a renaming_as_body. Used to enforce
1686 -- rule that a renaming_as_body is illegal if the declaration occurs
1687 -- before the subprogram it completes is frozen, and renaming indirectly
1688 -- renames the subprogram itself.(Defect Report 8652/0027).
1690 function Check_Class_Wide_Actual return Entity_Id;
1691 -- AI05-0071: In an instance, if the actual for a formal type FT with
1692 -- unknown discriminants is a class-wide type CT, and the generic has
1693 -- a formal subprogram with a box for a primitive operation of FT,
1694 -- then the corresponding actual subprogram denoted by the default is a
1695 -- class-wide operation whose body is a dispatching call. We replace the
1696 -- generated renaming declaration:
1698 -- procedure P (X : CT) renames P;
1700 -- by a different renaming and a class-wide operation:
1702 -- procedure Pr (X : T) renames P; -- renames primitive operation
1703 -- procedure P (X : CT); -- class-wide operation
1705 -- procedure P (X : CT) is begin Pr (X); end; -- dispatching call
1707 -- This rule only applies if there is no explicit visible class-wide
1708 -- operation at the point of the instantiation.
1710 function Has_Class_Wide_Actual return Boolean;
1711 -- Ada 2012 (AI05-071, AI05-0131): True if N is the renaming for a
1712 -- defaulted formal subprogram when the actual for the controlling
1713 -- formal type is class-wide.
1715 -----------------------------
1716 -- Check_Class_Wide_Actual --
1717 -----------------------------
1719 function Check_Class_Wide_Actual return Entity_Id is
1720 Loc : constant Source_Ptr := Sloc (N);
1723 Formal_Type : Entity_Id;
1724 Actual_Type : Entity_Id;
1729 function Make_Call (Prim_Op : Entity_Id) return Node_Id;
1730 -- Build dispatching call for body of class-wide operation
1732 function Make_Spec return Node_Id;
1733 -- Create subprogram specification for declaration and body of
1734 -- class-wide operation, using signature of renaming declaration.
1740 function Make_Call (Prim_Op : Entity_Id) return Node_Id is
1745 Actuals := New_List;
1746 F := First (Parameter_Specifications (Specification (New_Decl)));
1747 while Present (F) loop
1749 Make_Identifier (Loc, Chars (Defining_Identifier (F))));
1753 if Ekind_In (Prim_Op, E_Function, E_Operator) then
1754 return Make_Simple_Return_Statement (Loc,
1756 Make_Function_Call (Loc,
1757 Name => New_Occurrence_Of (Prim_Op, Loc),
1758 Parameter_Associations => Actuals));
1761 Make_Procedure_Call_Statement (Loc,
1762 Name => New_Occurrence_Of (Prim_Op, Loc),
1763 Parameter_Associations => Actuals);
1771 function Make_Spec return Node_Id is
1772 Param_Specs : constant List_Id := Copy_Parameter_List (New_S);
1775 if Ekind (New_S) = E_Procedure then
1777 Make_Procedure_Specification (Loc,
1778 Defining_Unit_Name =>
1779 Make_Defining_Identifier (Loc,
1780 Chars (Defining_Unit_Name (Spec))),
1781 Parameter_Specifications => Param_Specs);
1784 Make_Function_Specification (Loc,
1785 Defining_Unit_Name =>
1786 Make_Defining_Identifier (Loc,
1787 Chars (Defining_Unit_Name (Spec))),
1788 Parameter_Specifications => Param_Specs,
1789 Result_Definition =>
1790 New_Copy_Tree (Result_Definition (Spec)));
1794 -- Start of processing for Check_Class_Wide_Actual
1798 Formal_Type := Empty;
1799 Actual_Type := Empty;
1801 F := First_Formal (Formal_Spec);
1802 while Present (F) loop
1803 if Has_Unknown_Discriminants (Etype (F))
1804 and then not Is_Class_Wide_Type (Etype (F))
1805 and then Is_Class_Wide_Type (Get_Instance_Of (Etype (F)))
1807 Formal_Type := Etype (F);
1808 Actual_Type := Etype (Get_Instance_Of (Formal_Type));
1815 if Present (Formal_Type) then
1817 -- Create declaration and body for class-wide operation
1820 Make_Subprogram_Declaration (Loc, Specification => Make_Spec);
1823 Make_Subprogram_Body (Loc,
1824 Specification => Make_Spec,
1825 Declarations => No_List,
1826 Handled_Statement_Sequence =>
1827 Make_Handled_Sequence_Of_Statements (Loc, New_List));
1829 -- Modify Spec and create internal name for renaming of primitive
1832 Set_Defining_Unit_Name (Spec, Make_Temporary (Loc, 'R'));
1833 F := First (Parameter_Specifications (Spec));
1834 while Present (F) loop
1835 if Nkind (Parameter_Type (F)) = N_Identifier
1836 and then Is_Class_Wide_Type (Entity (Parameter_Type (F)))
1838 Set_Parameter_Type (F, New_Occurrence_Of (Actual_Type, Loc));
1843 New_S := Analyze_Subprogram_Specification (Spec);
1844 Result := Find_Renamed_Entity (N, Name (N), New_S, Is_Actual);
1847 if Result /= Any_Id then
1848 Insert_Before (N, New_Decl);
1851 -- Add dispatching call to body of class-wide operation
1853 Append (Make_Call (Result),
1854 Statements (Handled_Statement_Sequence (New_Body)));
1856 -- The generated body does not freeze. It is analyzed when the
1857 -- generated operation is frozen.
1859 Append_Freeze_Action (Defining_Entity (New_Decl), New_Body);
1861 Result := Defining_Entity (New_Decl);
1864 -- Return the class-wide operation if one was created
1867 end Check_Class_Wide_Actual;
1869 --------------------------
1870 -- Check_Null_Exclusion --
1871 --------------------------
1873 procedure Check_Null_Exclusion
1877 Ren_Formal : Entity_Id;
1878 Sub_Formal : Entity_Id;
1883 Ren_Formal := First_Formal (Ren);
1884 Sub_Formal := First_Formal (Sub);
1885 while Present (Ren_Formal)
1886 and then Present (Sub_Formal)
1888 if Has_Null_Exclusion (Parent (Ren_Formal))
1890 not (Has_Null_Exclusion (Parent (Sub_Formal))
1891 or else Can_Never_Be_Null (Etype (Sub_Formal)))
1894 ("`NOT NULL` required for parameter &",
1895 Parent (Sub_Formal), Sub_Formal);
1898 Next_Formal (Ren_Formal);
1899 Next_Formal (Sub_Formal);
1902 -- Return profile check
1904 if Nkind (Parent (Ren)) = N_Function_Specification
1905 and then Nkind (Parent (Sub)) = N_Function_Specification
1906 and then Has_Null_Exclusion (Parent (Ren))
1908 not (Has_Null_Exclusion (Parent (Sub))
1909 or else Can_Never_Be_Null (Etype (Sub)))
1912 ("return must specify `NOT NULL`",
1913 Result_Definition (Parent (Sub)));
1915 end Check_Null_Exclusion;
1917 ---------------------------
1918 -- Has_Class_Wide_Actual --
1919 ---------------------------
1921 function Has_Class_Wide_Actual return Boolean is
1927 and then Nkind (Nam) in N_Has_Entity
1928 and then Present (Entity (Nam))
1929 and then Is_Dispatching_Operation (Entity (Nam))
1931 F_Nam := First_Entity (Entity (Nam));
1932 F_Spec := First_Formal (Formal_Spec);
1933 while Present (F_Nam)
1934 and then Present (F_Spec)
1936 if Is_Controlling_Formal (F_Nam)
1937 and then Has_Unknown_Discriminants (Etype (F_Spec))
1938 and then not Is_Class_Wide_Type (Etype (F_Spec))
1939 and then Is_Class_Wide_Type (Get_Instance_Of (Etype (F_Spec)))
1944 Next_Entity (F_Nam);
1945 Next_Formal (F_Spec);
1950 end Has_Class_Wide_Actual;
1952 -------------------------
1953 -- Original_Subprogram --
1954 -------------------------
1956 function Original_Subprogram (Subp : Entity_Id) return Entity_Id is
1957 Orig_Decl : Node_Id;
1958 Orig_Subp : Entity_Id;
1961 -- First case: renamed entity is itself a renaming
1963 if Present (Alias (Subp)) then
1964 return Alias (Subp);
1967 Nkind (Unit_Declaration_Node (Subp)) = N_Subprogram_Declaration
1969 (Corresponding_Body (Unit_Declaration_Node (Subp)))
1971 -- Check if renamed entity is a renaming_as_body
1974 Unit_Declaration_Node
1975 (Corresponding_Body (Unit_Declaration_Node (Subp)));
1977 if Nkind (Orig_Decl) = N_Subprogram_Renaming_Declaration then
1978 Orig_Subp := Entity (Name (Orig_Decl));
1980 if Orig_Subp = Rename_Spec then
1982 -- Circularity detected
1987 return (Original_Subprogram (Orig_Subp));
1995 end Original_Subprogram;
1997 CW_Actual : constant Boolean := Has_Class_Wide_Actual;
1998 -- Ada 2012 (AI05-071, AI05-0131): True if the renaming is for a
1999 -- defaulted formal subprogram when the actual for a related formal
2000 -- type is class-wide.
2002 -- Start of processing for Analyze_Subprogram_Renaming
2005 -- We must test for the attribute renaming case before the Analyze
2006 -- call because otherwise Sem_Attr will complain that the attribute
2007 -- is missing an argument when it is analyzed.
2009 if Nkind (Nam) = N_Attribute_Reference then
2011 -- In the case of an abstract formal subprogram association, rewrite
2012 -- an actual given by a stream attribute as the name of the
2013 -- corresponding stream primitive of the type.
2015 -- In a generic context the stream operations are not generated, and
2016 -- this must be treated as a normal attribute reference, to be
2017 -- expanded in subsequent instantiations.
2019 if Is_Actual and then Is_Abstract_Subprogram (Formal_Spec)
2020 and then Expander_Active
2023 Stream_Prim : Entity_Id;
2024 Prefix_Type : constant Entity_Id := Entity (Prefix (Nam));
2027 -- The class-wide forms of the stream attributes are not
2028 -- primitive dispatching operations (even though they
2029 -- internally dispatch to a stream attribute).
2031 if Is_Class_Wide_Type (Prefix_Type) then
2033 ("attribute must be a primitive dispatching operation",
2038 -- Retrieve the primitive subprogram associated with the
2039 -- attribute. This can only be a stream attribute, since those
2040 -- are the only ones that are dispatching (and the actual for
2041 -- an abstract formal subprogram must be dispatching
2045 case Attribute_Name (Nam) is
2048 Find_Prim_Op (Prefix_Type, TSS_Stream_Input);
2051 Find_Prim_Op (Prefix_Type, TSS_Stream_Output);
2054 Find_Prim_Op (Prefix_Type, TSS_Stream_Read);
2057 Find_Prim_Op (Prefix_Type, TSS_Stream_Write);
2060 ("attribute must be a primitive"
2061 & " dispatching operation", Nam);
2067 -- If no operation was found, and the type is limited,
2068 -- the user should have defined one.
2070 when Program_Error =>
2071 if Is_Limited_Type (Prefix_Type) then
2073 ("stream operation not defined for type&",
2077 -- Otherwise, compiler should have generated default
2084 -- Rewrite the attribute into the name of its corresponding
2085 -- primitive dispatching subprogram. We can then proceed with
2086 -- the usual processing for subprogram renamings.
2089 Prim_Name : constant Node_Id :=
2090 Make_Identifier (Sloc (Nam),
2091 Chars => Chars (Stream_Prim));
2093 Set_Entity (Prim_Name, Stream_Prim);
2094 Rewrite (Nam, Prim_Name);
2099 -- Normal processing for a renaming of an attribute
2102 Attribute_Renaming (N);
2107 -- Check whether this declaration corresponds to the instantiation
2108 -- of a formal subprogram.
2110 -- If this is an instantiation, the corresponding actual is frozen and
2111 -- error messages can be made more precise. If this is a default
2112 -- subprogram, the entity is already established in the generic, and is
2113 -- not retrieved by visibility. If it is a default with a box, the
2114 -- candidate interpretations, if any, have been collected when building
2115 -- the renaming declaration. If overloaded, the proper interpretation is
2116 -- determined in Find_Renamed_Entity. If the entity is an operator,
2117 -- Find_Renamed_Entity applies additional visibility checks.
2120 Inst_Node := Unit_Declaration_Node (Formal_Spec);
2122 -- Check whether the renaming is for a defaulted actual subprogram
2123 -- with a class-wide actual.
2126 New_S := Analyze_Subprogram_Specification (Spec);
2127 Old_S := Check_Class_Wide_Actual;
2129 elsif Is_Entity_Name (Nam)
2130 and then Present (Entity (Nam))
2131 and then not Comes_From_Source (Nam)
2132 and then not Is_Overloaded (Nam)
2134 Old_S := Entity (Nam);
2135 New_S := Analyze_Subprogram_Specification (Spec);
2139 if Ekind (Entity (Nam)) = E_Operator then
2143 if Box_Present (Inst_Node) then
2144 Old_S := Find_Renamed_Entity (N, Name (N), New_S, Is_Actual);
2146 -- If there is an immediately visible homonym of the operator
2147 -- and the declaration has a default, this is worth a warning
2148 -- because the user probably did not intend to get the pre-
2149 -- defined operator, visible in the generic declaration. To
2150 -- find if there is an intended candidate, analyze the renaming
2151 -- again in the current context.
2153 elsif Scope (Old_S) = Standard_Standard
2154 and then Present (Default_Name (Inst_Node))
2157 Decl : constant Node_Id := New_Copy_Tree (N);
2161 Set_Entity (Name (Decl), Empty);
2162 Analyze (Name (Decl));
2164 Find_Renamed_Entity (Decl, Name (Decl), New_S, True);
2167 and then In_Open_Scopes (Scope (Hidden))
2168 and then Is_Immediately_Visible (Hidden)
2169 and then Comes_From_Source (Hidden)
2170 and then Hidden /= Old_S
2172 Error_Msg_Sloc := Sloc (Hidden);
2173 Error_Msg_N ("?default subprogram is resolved " &
2174 "in the generic declaration " &
2175 "(RM 12.6(17))", N);
2176 Error_Msg_NE ("\?and will not use & #", N, Hidden);
2184 New_S := Analyze_Subprogram_Specification (Spec);
2188 -- Renamed entity must be analyzed first, to avoid being hidden by
2189 -- new name (which might be the same in a generic instance).
2193 -- The renaming defines a new overloaded entity, which is analyzed
2194 -- like a subprogram declaration.
2196 New_S := Analyze_Subprogram_Specification (Spec);
2199 if Current_Scope /= Standard_Standard then
2200 Set_Is_Pure (New_S, Is_Pure (Current_Scope));
2203 Rename_Spec := Find_Corresponding_Spec (N);
2205 -- Case of Renaming_As_Body
2207 if Present (Rename_Spec) then
2209 -- Renaming declaration is the completion of the declaration of
2210 -- Rename_Spec. We build an actual body for it at the freezing point.
2212 Set_Corresponding_Spec (N, Rename_Spec);
2214 -- Deal with special case of stream functions of abstract types
2217 if Nkind (Unit_Declaration_Node (Rename_Spec)) =
2218 N_Abstract_Subprogram_Declaration
2220 -- Input stream functions are abstract if the object type is
2221 -- abstract. Similarly, all default stream functions for an
2222 -- interface type are abstract. However, these subprograms may
2223 -- receive explicit declarations in representation clauses, making
2224 -- the attribute subprograms usable as defaults in subsequent
2226 -- In this case we rewrite the declaration to make the subprogram
2227 -- non-abstract. We remove the previous declaration, and insert
2228 -- the new one at the point of the renaming, to prevent premature
2229 -- access to unfrozen types. The new declaration reuses the
2230 -- specification of the previous one, and must not be analyzed.
2233 (Is_Primitive (Entity (Nam))
2235 Is_Abstract_Type (Find_Dispatching_Type (Entity (Nam))));
2237 Old_Decl : constant Node_Id :=
2238 Unit_Declaration_Node (Rename_Spec);
2239 New_Decl : constant Node_Id :=
2240 Make_Subprogram_Declaration (Sloc (N),
2242 Relocate_Node (Specification (Old_Decl)));
2245 Insert_After (N, New_Decl);
2246 Set_Is_Abstract_Subprogram (Rename_Spec, False);
2247 Set_Analyzed (New_Decl);
2251 Set_Corresponding_Body (Unit_Declaration_Node (Rename_Spec), New_S);
2253 if Ada_Version = Ada_83 and then Comes_From_Source (N) then
2254 Error_Msg_N ("(Ada 83) renaming cannot serve as a body", N);
2257 Set_Convention (New_S, Convention (Rename_Spec));
2258 Check_Fully_Conformant (New_S, Rename_Spec);
2259 Set_Public_Status (New_S);
2261 -- The specification does not introduce new formals, but only
2262 -- repeats the formals of the original subprogram declaration.
2263 -- For cross-reference purposes, and for refactoring tools, we
2264 -- treat the formals of the renaming declaration as body formals.
2266 Reference_Body_Formals (Rename_Spec, New_S);
2268 -- Indicate that the entity in the declaration functions like the
2269 -- corresponding body, and is not a new entity. The body will be
2270 -- constructed later at the freeze point, so indicate that the
2271 -- completion has not been seen yet.
2273 Set_Ekind (New_S, E_Subprogram_Body);
2274 New_S := Rename_Spec;
2275 Set_Has_Completion (Rename_Spec, False);
2277 -- Ada 2005: check overriding indicator
2279 if Present (Overridden_Operation (Rename_Spec)) then
2280 if Must_Not_Override (Specification (N)) then
2282 ("subprogram& overrides inherited operation",
2285 Style_Check and then not Must_Override (Specification (N))
2287 Style.Missing_Overriding (N, Rename_Spec);
2290 elsif Must_Override (Specification (N)) then
2291 Error_Msg_NE ("subprogram& is not overriding", N, Rename_Spec);
2294 -- Normal subprogram renaming (not renaming as body)
2297 Generate_Definition (New_S);
2298 New_Overloaded_Entity (New_S);
2300 if Is_Entity_Name (Nam)
2301 and then Is_Intrinsic_Subprogram (Entity (Nam))
2305 Check_Delayed_Subprogram (New_S);
2309 -- There is no need for elaboration checks on the new entity, which may
2310 -- be called before the next freezing point where the body will appear.
2311 -- Elaboration checks refer to the real entity, not the one created by
2312 -- the renaming declaration.
2314 Set_Kill_Elaboration_Checks (New_S, True);
2316 if Etype (Nam) = Any_Type then
2317 Set_Has_Completion (New_S);
2320 elsif Nkind (Nam) = N_Selected_Component then
2322 -- A prefix of the form A.B can designate an entry of task A, a
2323 -- protected operation of protected object A, or finally a primitive
2324 -- operation of object A. In the later case, A is an object of some
2325 -- tagged type, or an access type that denotes one such. To further
2326 -- distinguish these cases, note that the scope of a task entry or
2327 -- protected operation is type of the prefix.
2329 -- The prefix could be an overloaded function call that returns both
2330 -- kinds of operations. This overloading pathology is left to the
2331 -- dedicated reader ???
2334 T : constant Entity_Id := Etype (Prefix (Nam));
2343 Is_Tagged_Type (Designated_Type (T))))
2344 and then Scope (Entity (Selector_Name (Nam))) /= T
2346 Analyze_Renamed_Primitive_Operation
2347 (N, New_S, Present (Rename_Spec));
2351 -- Renamed entity is an entry or protected operation. For those
2352 -- cases an explicit body is built (at the point of freezing of
2353 -- this entity) that contains a call to the renamed entity.
2355 -- This is not allowed for renaming as body if the renamed
2356 -- spec is already frozen (see RM 8.5.4(5) for details).
2358 if Present (Rename_Spec)
2359 and then Is_Frozen (Rename_Spec)
2362 ("renaming-as-body cannot rename entry as subprogram", N);
2364 ("\since & is already frozen (RM 8.5.4(5))",
2367 Analyze_Renamed_Entry (N, New_S, Present (Rename_Spec));
2374 elsif Nkind (Nam) = N_Explicit_Dereference then
2376 -- Renamed entity is designated by access_to_subprogram expression.
2377 -- Must build body to encapsulate call, as in the entry case.
2379 Analyze_Renamed_Dereference (N, New_S, Present (Rename_Spec));
2382 elsif Nkind (Nam) = N_Indexed_Component then
2383 Analyze_Renamed_Family_Member (N, New_S, Present (Rename_Spec));
2386 elsif Nkind (Nam) = N_Character_Literal then
2387 Analyze_Renamed_Character (N, New_S, Present (Rename_Spec));
2390 elsif not Is_Entity_Name (Nam)
2391 or else not Is_Overloadable (Entity (Nam))
2393 Error_Msg_N ("expect valid subprogram name in renaming", N);
2397 -- Find the renamed entity that matches the given specification. Disable
2398 -- Ada_83 because there is no requirement of full conformance between
2399 -- renamed entity and new entity, even though the same circuit is used.
2401 -- This is a bit of a kludge, which introduces a really irregular use of
2402 -- Ada_Version[_Explicit]. Would be nice to find cleaner way to do this
2405 Ada_Version := Ada_Version_Type'Max (Ada_Version, Ada_95);
2406 Ada_Version_Explicit := Ada_Version;
2409 Old_S := Find_Renamed_Entity (N, Name (N), New_S, Is_Actual);
2411 -- The visible operation may be an inherited abstract operation that
2412 -- was overridden in the private part, in which case a call will
2413 -- dispatch to the overriding operation. Use the overriding one in
2414 -- the renaming declaration, to prevent spurious errors below.
2416 if Is_Overloadable (Old_S)
2417 and then Is_Abstract_Subprogram (Old_S)
2418 and then No (DTC_Entity (Old_S))
2419 and then Present (Alias (Old_S))
2420 and then not Is_Abstract_Subprogram (Alias (Old_S))
2421 and then Present (Overridden_Operation (Alias (Old_S)))
2423 Old_S := Alias (Old_S);
2426 -- When the renamed subprogram is overloaded and used as an actual
2427 -- of a generic, its entity is set to the first available homonym.
2428 -- We must first disambiguate the name, then set the proper entity.
2430 if Is_Actual and then Is_Overloaded (Nam) then
2431 Set_Entity (Nam, Old_S);
2435 -- Most common case: subprogram renames subprogram. No body is generated
2436 -- in this case, so we must indicate the declaration is complete as is.
2437 -- and inherit various attributes of the renamed subprogram.
2439 if No (Rename_Spec) then
2440 Set_Has_Completion (New_S);
2441 Set_Is_Imported (New_S, Is_Imported (Entity (Nam)));
2442 Set_Is_Pure (New_S, Is_Pure (Entity (Nam)));
2443 Set_Is_Preelaborated (New_S, Is_Preelaborated (Entity (Nam)));
2445 -- Ada 2005 (AI-423): Check the consistency of null exclusions
2446 -- between a subprogram and its correct renaming.
2448 -- Note: the Any_Id check is a guard that prevents compiler crashes
2449 -- when performing a null exclusion check between a renaming and a
2450 -- renamed subprogram that has been found to be illegal.
2452 if Ada_Version >= Ada_2005
2453 and then Entity (Nam) /= Any_Id
2455 Check_Null_Exclusion
2457 Sub => Entity (Nam));
2460 -- Enforce the Ada 2005 rule that the renamed entity cannot require
2461 -- overriding. The flag Requires_Overriding is set very selectively
2462 -- and misses some other illegal cases. The additional conditions
2463 -- checked below are sufficient but not necessary ???
2465 -- The rule does not apply to the renaming generated for an actual
2466 -- subprogram in an instance.
2471 -- Guard against previous errors, and omit renamings of predefined
2474 elsif not Ekind_In (Old_S, E_Function, E_Procedure) then
2477 elsif Requires_Overriding (Old_S)
2479 (Is_Abstract_Subprogram (Old_S)
2480 and then Present (Find_Dispatching_Type (Old_S))
2482 not Is_Abstract_Type (Find_Dispatching_Type (Old_S)))
2485 ("renamed entity cannot be "
2486 & "subprogram that requires overriding (RM 8.5.4 (5.1))", N);
2490 if Old_S /= Any_Id then
2491 if Is_Actual and then From_Default (N) then
2493 -- This is an implicit reference to the default actual
2495 Generate_Reference (Old_S, Nam, Typ => 'i', Force => True);
2498 Generate_Reference (Old_S, Nam);
2501 -- For a renaming-as-body, require subtype conformance, but if the
2502 -- declaration being completed has not been frozen, then inherit the
2503 -- convention of the renamed subprogram prior to checking conformance
2504 -- (unless the renaming has an explicit convention established; the
2505 -- rule stated in the RM doesn't seem to address this ???).
2507 if Present (Rename_Spec) then
2508 Generate_Reference (Rename_Spec, Defining_Entity (Spec), 'b');
2509 Style.Check_Identifier (Defining_Entity (Spec), Rename_Spec);
2511 if not Is_Frozen (Rename_Spec) then
2512 if not Has_Convention_Pragma (Rename_Spec) then
2513 Set_Convention (New_S, Convention (Old_S));
2516 if Ekind (Old_S) /= E_Operator then
2517 Check_Mode_Conformant (New_S, Old_S, Spec);
2520 if Original_Subprogram (Old_S) = Rename_Spec then
2521 Error_Msg_N ("unfrozen subprogram cannot rename itself ", N);
2524 Check_Subtype_Conformant (New_S, Old_S, Spec);
2527 Check_Frozen_Renaming (N, Rename_Spec);
2529 -- Check explicitly that renamed entity is not intrinsic, because
2530 -- in a generic the renamed body is not built. In this case,
2531 -- the renaming_as_body is a completion.
2533 if Inside_A_Generic then
2534 if Is_Frozen (Rename_Spec)
2535 and then Is_Intrinsic_Subprogram (Old_S)
2538 ("subprogram in renaming_as_body cannot be intrinsic",
2542 Set_Has_Completion (Rename_Spec);
2545 elsif Ekind (Old_S) /= E_Operator then
2547 -- If this a defaulted subprogram for a class-wide actual there is
2548 -- no check for mode conformance, given that the signatures don't
2549 -- match (the source mentions T but the actual mentions T'Class).
2554 Check_Mode_Conformant (New_S, Old_S);
2558 and then Error_Posted (New_S)
2560 Error_Msg_NE ("invalid actual subprogram: & #!", N, Old_S);
2564 if No (Rename_Spec) then
2566 -- The parameter profile of the new entity is that of the renamed
2567 -- entity: the subtypes given in the specification are irrelevant.
2569 Inherit_Renamed_Profile (New_S, Old_S);
2571 -- A call to the subprogram is transformed into a call to the
2572 -- renamed entity. This is transitive if the renamed entity is
2573 -- itself a renaming.
2575 if Present (Alias (Old_S)) then
2576 Set_Alias (New_S, Alias (Old_S));
2578 Set_Alias (New_S, Old_S);
2581 -- Note that we do not set Is_Intrinsic_Subprogram if we have a
2582 -- renaming as body, since the entity in this case is not an
2583 -- intrinsic (it calls an intrinsic, but we have a real body for
2584 -- this call, and it is in this body that the required intrinsic
2585 -- processing will take place).
2587 -- Also, if this is a renaming of inequality, the renamed operator
2588 -- is intrinsic, but what matters is the corresponding equality
2589 -- operator, which may be user-defined.
2591 Set_Is_Intrinsic_Subprogram
2593 Is_Intrinsic_Subprogram (Old_S)
2595 (Chars (Old_S) /= Name_Op_Ne
2596 or else Ekind (Old_S) = E_Operator
2598 Is_Intrinsic_Subprogram
2599 (Corresponding_Equality (Old_S))));
2601 if Ekind (Alias (New_S)) = E_Operator then
2602 Set_Has_Delayed_Freeze (New_S, False);
2605 -- If the renaming corresponds to an association for an abstract
2606 -- formal subprogram, then various attributes must be set to
2607 -- indicate that the renaming is an abstract dispatching operation
2608 -- with a controlling type.
2610 if Is_Actual and then Is_Abstract_Subprogram (Formal_Spec) then
2612 -- Mark the renaming as abstract here, so Find_Dispatching_Type
2613 -- see it as corresponding to a generic association for a
2614 -- formal abstract subprogram
2616 Set_Is_Abstract_Subprogram (New_S);
2619 New_S_Ctrl_Type : constant Entity_Id :=
2620 Find_Dispatching_Type (New_S);
2621 Old_S_Ctrl_Type : constant Entity_Id :=
2622 Find_Dispatching_Type (Old_S);
2625 if Old_S_Ctrl_Type /= New_S_Ctrl_Type then
2627 ("actual must be dispatching subprogram for type&",
2628 Nam, New_S_Ctrl_Type);
2631 Set_Is_Dispatching_Operation (New_S);
2632 Check_Controlling_Formals (New_S_Ctrl_Type, New_S);
2634 -- If the actual in the formal subprogram is itself a
2635 -- formal abstract subprogram association, there's no
2636 -- dispatch table component or position to inherit.
2638 if Present (DTC_Entity (Old_S)) then
2639 Set_DTC_Entity (New_S, DTC_Entity (Old_S));
2640 Set_DT_Position (New_S, DT_Position (Old_S));
2648 and then (Old_S = New_S
2649 or else (Nkind (Nam) /= N_Expanded_Name
2650 and then Chars (Old_S) = Chars (New_S)))
2652 Error_Msg_N ("subprogram cannot rename itself", N);
2655 Set_Convention (New_S, Convention (Old_S));
2657 if Is_Abstract_Subprogram (Old_S) then
2658 if Present (Rename_Spec) then
2660 ("a renaming-as-body cannot rename an abstract subprogram",
2662 Set_Has_Completion (Rename_Spec);
2664 Set_Is_Abstract_Subprogram (New_S);
2668 Check_Library_Unit_Renaming (N, Old_S);
2670 -- Pathological case: procedure renames entry in the scope of its
2671 -- task. Entry is given by simple name, but body must be built for
2672 -- procedure. Of course if called it will deadlock.
2674 if Ekind (Old_S) = E_Entry then
2675 Set_Has_Completion (New_S, False);
2676 Set_Alias (New_S, Empty);
2680 Freeze_Before (N, Old_S);
2681 Set_Has_Delayed_Freeze (New_S, False);
2682 Freeze_Before (N, New_S);
2684 -- An abstract subprogram is only allowed as an actual in the case
2685 -- where the formal subprogram is also abstract.
2687 if (Ekind (Old_S) = E_Procedure or else Ekind (Old_S) = E_Function)
2688 and then Is_Abstract_Subprogram (Old_S)
2689 and then not Is_Abstract_Subprogram (Formal_Spec)
2692 ("abstract subprogram not allowed as generic actual", Nam);
2697 -- A common error is to assume that implicit operators for types are
2698 -- defined in Standard, or in the scope of a subtype. In those cases
2699 -- where the renamed entity is given with an expanded name, it is
2700 -- worth mentioning that operators for the type are not declared in
2701 -- the scope given by the prefix.
2703 if Nkind (Nam) = N_Expanded_Name
2704 and then Nkind (Selector_Name (Nam)) = N_Operator_Symbol
2705 and then Scope (Entity (Nam)) = Standard_Standard
2708 T : constant Entity_Id :=
2709 Base_Type (Etype (First_Formal (New_S)));
2711 Error_Msg_Node_2 := Prefix (Nam);
2713 ("operator for type& is not declared in&", Prefix (Nam), T);
2718 ("no visible subprogram matches the specification for&",
2722 if Present (Candidate_Renaming) then
2729 F1 := First_Formal (Candidate_Renaming);
2730 F2 := First_Formal (New_S);
2731 T1 := First_Subtype (Etype (F1));
2733 while Present (F1) and then Present (F2) loop
2738 if Present (F1) and then Present (Default_Value (F1)) then
2739 if Present (Next_Formal (F1)) then
2741 ("\missing specification for &" &
2742 " and other formals with defaults", Spec, F1);
2745 ("\missing specification for &", Spec, F1);
2749 if Nkind (Nam) = N_Operator_Symbol
2750 and then From_Default (N)
2752 Error_Msg_Node_2 := T1;
2754 ("default & on & is not directly visible",
2761 -- Ada 2005 AI 404: if the new subprogram is dispatching, verify that
2762 -- controlling access parameters are known non-null for the renamed
2763 -- subprogram. Test also applies to a subprogram instantiation that
2764 -- is dispatching. Test is skipped if some previous error was detected
2765 -- that set Old_S to Any_Id.
2767 if Ada_Version >= Ada_2005
2768 and then Old_S /= Any_Id
2769 and then not Is_Dispatching_Operation (Old_S)
2770 and then Is_Dispatching_Operation (New_S)
2777 Old_F := First_Formal (Old_S);
2778 New_F := First_Formal (New_S);
2779 while Present (Old_F) loop
2780 if Ekind (Etype (Old_F)) = E_Anonymous_Access_Type
2781 and then Is_Controlling_Formal (New_F)
2782 and then not Can_Never_Be_Null (Old_F)
2784 Error_Msg_N ("access parameter is controlling,", New_F);
2786 ("\corresponding parameter of& "
2787 & "must be explicitly null excluding", New_F, Old_S);
2790 Next_Formal (Old_F);
2791 Next_Formal (New_F);
2796 -- A useful warning, suggested by Ada Bug Finder (Ada-Europe 2005)
2797 -- is to warn if an operator is being renamed as a different operator.
2798 -- If the operator is predefined, examine the kind of the entity, not
2799 -- the abbreviated declaration in Standard.
2801 if Comes_From_Source (N)
2802 and then Present (Old_S)
2804 (Nkind (Old_S) = N_Defining_Operator_Symbol
2805 or else Ekind (Old_S) = E_Operator)
2806 and then Nkind (New_S) = N_Defining_Operator_Symbol
2807 and then Chars (Old_S) /= Chars (New_S)
2810 ("?& is being renamed as a different operator", N, Old_S);
2813 -- Check for renaming of obsolescent subprogram
2815 Check_Obsolescent_2005_Entity (Entity (Nam), Nam);
2817 -- Another warning or some utility: if the new subprogram as the same
2818 -- name as the old one, the old one is not hidden by an outer homograph,
2819 -- the new one is not a public symbol, and the old one is otherwise
2820 -- directly visible, the renaming is superfluous.
2822 if Chars (Old_S) = Chars (New_S)
2823 and then Comes_From_Source (N)
2824 and then Scope (Old_S) /= Standard_Standard
2825 and then Warn_On_Redundant_Constructs
2827 (Is_Immediately_Visible (Old_S)
2828 or else Is_Potentially_Use_Visible (Old_S))
2829 and then Is_Overloadable (Current_Scope)
2830 and then Chars (Current_Scope) /= Chars (Old_S)
2833 ("?redundant renaming, entity is directly visible", Name (N));
2836 Ada_Version := Save_AV;
2837 Ada_Version_Explicit := Save_AV_Exp;
2838 end Analyze_Subprogram_Renaming;
2840 -------------------------
2841 -- Analyze_Use_Package --
2842 -------------------------
2844 -- Resolve the package names in the use clause, and make all the visible
2845 -- entities defined in the package potentially use-visible. If the package
2846 -- is already in use from a previous use clause, its visible entities are
2847 -- already use-visible. In that case, mark the occurrence as a redundant
2848 -- use. If the package is an open scope, i.e. if the use clause occurs
2849 -- within the package itself, ignore it.
2851 procedure Analyze_Use_Package (N : Node_Id) is
2852 Pack_Name : Node_Id;
2855 -- Start of processing for Analyze_Use_Package
2858 Check_SPARK_Restriction ("use clause is not allowed", N);
2860 Set_Hidden_By_Use_Clause (N, No_Elist);
2862 -- Use clause not allowed in a spec of a predefined package declaration
2863 -- except that packages whose file name starts a-n are OK (these are
2864 -- children of Ada.Numerics, which are never loaded by Rtsfind).
2866 if Is_Predefined_File_Name (Unit_File_Name (Current_Sem_Unit))
2867 and then Name_Buffer (1 .. 3) /= "a-n"
2869 Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Declaration
2871 Error_Msg_N ("use clause not allowed in predefined spec", N);
2874 -- Chain clause to list of use clauses in current scope
2876 if Nkind (Parent (N)) /= N_Compilation_Unit then
2877 Chain_Use_Clause (N);
2880 -- Loop through package names to identify referenced packages
2882 Pack_Name := First (Names (N));
2883 while Present (Pack_Name) loop
2884 Analyze (Pack_Name);
2886 if Nkind (Parent (N)) = N_Compilation_Unit
2887 and then Nkind (Pack_Name) = N_Expanded_Name
2893 Pref := Prefix (Pack_Name);
2894 while Nkind (Pref) = N_Expanded_Name loop
2895 Pref := Prefix (Pref);
2898 if Entity (Pref) = Standard_Standard then
2900 ("predefined package Standard cannot appear"
2901 & " in a context clause", Pref);
2909 -- Loop through package names to mark all entities as potentially
2912 Pack_Name := First (Names (N));
2913 while Present (Pack_Name) loop
2914 if Is_Entity_Name (Pack_Name) then
2915 Pack := Entity (Pack_Name);
2917 if Ekind (Pack) /= E_Package
2918 and then Etype (Pack) /= Any_Type
2920 if Ekind (Pack) = E_Generic_Package then
2921 Error_Msg_N -- CODEFIX
2922 ("a generic package is not allowed in a use clause",
2925 Error_Msg_N ("& is not a usable package", Pack_Name);
2929 if Nkind (Parent (N)) = N_Compilation_Unit then
2930 Check_In_Previous_With_Clause (N, Pack_Name);
2933 if Applicable_Use (Pack_Name) then
2934 Use_One_Package (Pack, N);
2938 -- Report error because name denotes something other than a package
2941 Error_Msg_N ("& is not a package", Pack_Name);
2946 end Analyze_Use_Package;
2948 ----------------------
2949 -- Analyze_Use_Type --
2950 ----------------------
2952 procedure Analyze_Use_Type (N : Node_Id) is
2957 Set_Hidden_By_Use_Clause (N, No_Elist);
2959 -- Chain clause to list of use clauses in current scope
2961 if Nkind (Parent (N)) /= N_Compilation_Unit then
2962 Chain_Use_Clause (N);
2965 -- If the Used_Operations list is already initialized, the clause has
2966 -- been analyzed previously, and it is begin reinstalled, for example
2967 -- when the clause appears in a package spec and we are compiling the
2968 -- corresponding package body. In that case, make the entities on the
2969 -- existing list use_visible, and mark the corresponding types In_Use.
2971 if Present (Used_Operations (N)) then
2977 Mark := First (Subtype_Marks (N));
2978 while Present (Mark) loop
2979 Use_One_Type (Mark, Installed => True);
2983 Elmt := First_Elmt (Used_Operations (N));
2984 while Present (Elmt) loop
2985 Set_Is_Potentially_Use_Visible (Node (Elmt));
2993 -- Otherwise, create new list and attach to it the operations that
2994 -- are made use-visible by the clause.
2996 Set_Used_Operations (N, New_Elmt_List);
2997 Id := First (Subtype_Marks (N));
2998 while Present (Id) loop
3002 if E /= Any_Type then
3005 if Nkind (Parent (N)) = N_Compilation_Unit then
3006 if Nkind (Id) = N_Identifier then
3007 Error_Msg_N ("type is not directly visible", Id);
3009 elsif Is_Child_Unit (Scope (E))
3010 and then Scope (E) /= System_Aux_Id
3012 Check_In_Previous_With_Clause (N, Prefix (Id));
3017 -- If the use_type_clause appears in a compilation unit context,
3018 -- check whether it comes from a unit that may appear in a
3019 -- limited_with_clause, for a better error message.
3021 if Nkind (Parent (N)) = N_Compilation_Unit
3022 and then Nkind (Id) /= N_Identifier
3028 function Mentioned (Nam : Node_Id) return Boolean;
3029 -- Check whether the prefix of expanded name for the type
3030 -- appears in the prefix of some limited_with_clause.
3036 function Mentioned (Nam : Node_Id) return Boolean is
3038 return Nkind (Name (Item)) = N_Selected_Component
3040 Chars (Prefix (Name (Item))) = Chars (Nam);
3044 Pref := Prefix (Id);
3045 Item := First (Context_Items (Parent (N)));
3047 while Present (Item) and then Item /= N loop
3048 if Nkind (Item) = N_With_Clause
3049 and then Limited_Present (Item)
3050 and then Mentioned (Pref)
3053 (Get_Msg_Id, "premature usage of incomplete type");
3064 end Analyze_Use_Type;
3066 --------------------
3067 -- Applicable_Use --
3068 --------------------
3070 function Applicable_Use (Pack_Name : Node_Id) return Boolean is
3071 Pack : constant Entity_Id := Entity (Pack_Name);
3074 if In_Open_Scopes (Pack) then
3075 if Warn_On_Redundant_Constructs
3076 and then Pack = Current_Scope
3078 Error_Msg_NE -- CODEFIX
3079 ("& is already use-visible within itself?", Pack_Name, Pack);
3084 elsif In_Use (Pack) then
3085 Note_Redundant_Use (Pack_Name);
3088 elsif Present (Renamed_Object (Pack))
3089 and then In_Use (Renamed_Object (Pack))
3091 Note_Redundant_Use (Pack_Name);
3099 ------------------------
3100 -- Attribute_Renaming --
3101 ------------------------
3103 procedure Attribute_Renaming (N : Node_Id) is
3104 Loc : constant Source_Ptr := Sloc (N);
3105 Nam : constant Node_Id := Name (N);
3106 Spec : constant Node_Id := Specification (N);
3107 New_S : constant Entity_Id := Defining_Unit_Name (Spec);
3108 Aname : constant Name_Id := Attribute_Name (Nam);
3110 Form_Num : Nat := 0;
3111 Expr_List : List_Id := No_List;
3113 Attr_Node : Node_Id;
3114 Body_Node : Node_Id;
3115 Param_Spec : Node_Id;
3118 Generate_Definition (New_S);
3120 -- This procedure is called in the context of subprogram renaming, and
3121 -- thus the attribute must be one that is a subprogram. All of those
3122 -- have at least one formal parameter, with the singular exception of
3123 -- AST_Entry (which is a real oddity, it is odd that this can be renamed
3126 if not Is_Non_Empty_List (Parameter_Specifications (Spec)) then
3127 if Aname /= Name_AST_Entry then
3129 ("subprogram renaming an attribute must have formals", N);
3134 Param_Spec := First (Parameter_Specifications (Spec));
3135 while Present (Param_Spec) loop
3136 Form_Num := Form_Num + 1;
3138 if Nkind (Parameter_Type (Param_Spec)) /= N_Access_Definition then
3139 Find_Type (Parameter_Type (Param_Spec));
3141 -- The profile of the new entity denotes the base type (s) of
3142 -- the types given in the specification. For access parameters
3143 -- there are no subtypes involved.
3145 Rewrite (Parameter_Type (Param_Spec),
3147 (Base_Type (Entity (Parameter_Type (Param_Spec))), Loc));
3150 if No (Expr_List) then
3151 Expr_List := New_List;
3154 Append_To (Expr_List,
3155 Make_Identifier (Loc,
3156 Chars => Chars (Defining_Identifier (Param_Spec))));
3158 -- The expressions in the attribute reference are not freeze
3159 -- points. Neither is the attribute as a whole, see below.
3161 Set_Must_Not_Freeze (Last (Expr_List));
3166 -- Immediate error if too many formals. Other mismatches in number or
3167 -- types of parameters are detected when we analyze the body of the
3168 -- subprogram that we construct.
3170 if Form_Num > 2 then
3171 Error_Msg_N ("too many formals for attribute", N);
3173 -- Error if the attribute reference has expressions that look like
3174 -- formal parameters.
3176 elsif Present (Expressions (Nam)) then
3177 Error_Msg_N ("illegal expressions in attribute reference", Nam);
3180 Aname = Name_Compose or else
3181 Aname = Name_Exponent or else
3182 Aname = Name_Leading_Part or else
3183 Aname = Name_Pos or else
3184 Aname = Name_Round or else
3185 Aname = Name_Scaling or else
3188 if Nkind (N) = N_Subprogram_Renaming_Declaration
3189 and then Present (Corresponding_Formal_Spec (N))
3192 ("generic actual cannot be attribute involving universal type",
3196 ("attribute involving a universal type cannot be renamed",
3201 -- AST_Entry is an odd case. It doesn't really make much sense to allow
3202 -- it to be renamed, but that's the DEC rule, so we have to do it right.
3203 -- The point is that the AST_Entry call should be made now, and what the
3204 -- function will return is the returned value.
3206 -- Note that there is no Expr_List in this case anyway
3208 if Aname = Name_AST_Entry then
3210 Ent : constant Entity_Id := Make_Temporary (Loc, 'R', Nam);
3215 Make_Object_Declaration (Loc,
3216 Defining_Identifier => Ent,
3217 Object_Definition =>
3218 New_Occurrence_Of (RTE (RE_AST_Handler), Loc),
3220 Constant_Present => True);
3222 Set_Assignment_OK (Decl, True);
3223 Insert_Action (N, Decl);
3224 Attr_Node := Make_Identifier (Loc, Chars (Ent));
3227 -- For all other attributes, we rewrite the attribute node to have
3228 -- a list of expressions corresponding to the subprogram formals.
3229 -- A renaming declaration is not a freeze point, and the analysis of
3230 -- the attribute reference should not freeze the type of the prefix.
3234 Make_Attribute_Reference (Loc,
3235 Prefix => Prefix (Nam),
3236 Attribute_Name => Aname,
3237 Expressions => Expr_List);
3239 Set_Must_Not_Freeze (Attr_Node);
3240 Set_Must_Not_Freeze (Prefix (Nam));
3243 -- Case of renaming a function
3245 if Nkind (Spec) = N_Function_Specification then
3246 if Is_Procedure_Attribute_Name (Aname) then
3247 Error_Msg_N ("attribute can only be renamed as procedure", Nam);
3251 Find_Type (Result_Definition (Spec));
3252 Rewrite (Result_Definition (Spec),
3254 Base_Type (Entity (Result_Definition (Spec))), Loc));
3257 Make_Subprogram_Body (Loc,
3258 Specification => Spec,
3259 Declarations => New_List,
3260 Handled_Statement_Sequence =>
3261 Make_Handled_Sequence_Of_Statements (Loc,
3262 Statements => New_List (
3263 Make_Simple_Return_Statement (Loc,
3264 Expression => Attr_Node))));
3266 -- Case of renaming a procedure
3269 if not Is_Procedure_Attribute_Name (Aname) then
3270 Error_Msg_N ("attribute can only be renamed as function", Nam);
3275 Make_Subprogram_Body (Loc,
3276 Specification => Spec,
3277 Declarations => New_List,
3278 Handled_Statement_Sequence =>
3279 Make_Handled_Sequence_Of_Statements (Loc,
3280 Statements => New_List (Attr_Node)));
3283 -- In case of tagged types we add the body of the generated function to
3284 -- the freezing actions of the type (because in the general case such
3285 -- type is still not frozen). We exclude from this processing generic
3286 -- formal subprograms found in instantiations and AST_Entry renamings.
3288 -- We must exclude VM targets because entity AST_Handler is defined in
3289 -- package System.Aux_Dec which is not available in those platforms.
3291 if VM_Target = No_VM
3292 and then not Present (Corresponding_Formal_Spec (N))
3293 and then Etype (Nam) /= RTE (RE_AST_Handler)
3296 P : constant Entity_Id := Prefix (Nam);
3301 if Is_Tagged_Type (Etype (P)) then
3302 Ensure_Freeze_Node (Etype (P));
3303 Append_Freeze_Action (Etype (P), Body_Node);
3305 Rewrite (N, Body_Node);
3307 Set_Etype (New_S, Base_Type (Etype (New_S)));
3311 -- Generic formal subprograms or AST_Handler renaming
3314 Rewrite (N, Body_Node);
3316 Set_Etype (New_S, Base_Type (Etype (New_S)));
3319 if Is_Compilation_Unit (New_S) then
3321 ("a library unit can only rename another library unit", N);
3324 -- We suppress elaboration warnings for the resulting entity, since
3325 -- clearly they are not needed, and more particularly, in the case
3326 -- of a generic formal subprogram, the resulting entity can appear
3327 -- after the instantiation itself, and thus look like a bogus case
3328 -- of access before elaboration.
3330 Set_Suppress_Elaboration_Warnings (New_S);
3332 end Attribute_Renaming;
3334 ----------------------
3335 -- Chain_Use_Clause --
3336 ----------------------
3338 procedure Chain_Use_Clause (N : Node_Id) is
3340 Level : Int := Scope_Stack.Last;
3343 if not Is_Compilation_Unit (Current_Scope)
3344 or else not Is_Child_Unit (Current_Scope)
3346 null; -- Common case
3348 elsif Defining_Entity (Parent (N)) = Current_Scope then
3349 null; -- Common case for compilation unit
3352 -- If declaration appears in some other scope, it must be in some
3353 -- parent unit when compiling a child.
3355 Pack := Defining_Entity (Parent (N));
3356 if not In_Open_Scopes (Pack) then
3357 null; -- default as well
3360 -- Find entry for parent unit in scope stack
3362 while Scope_Stack.Table (Level).Entity /= Pack loop
3368 Set_Next_Use_Clause (N,
3369 Scope_Stack.Table (Level).First_Use_Clause);
3370 Scope_Stack.Table (Level).First_Use_Clause := N;
3371 end Chain_Use_Clause;
3373 ---------------------------
3374 -- Check_Frozen_Renaming --
3375 ---------------------------
3377 procedure Check_Frozen_Renaming (N : Node_Id; Subp : Entity_Id) is
3383 and then not Has_Completion (Subp)
3387 (Parent (Declaration_Node (Subp)), Defining_Entity (N));
3389 if Is_Entity_Name (Name (N)) then
3390 Old_S := Entity (Name (N));
3392 if not Is_Frozen (Old_S)
3393 and then Operating_Mode /= Check_Semantics
3395 Append_Freeze_Action (Old_S, B_Node);
3397 Insert_After (N, B_Node);
3401 if Is_Intrinsic_Subprogram (Old_S)
3402 and then not In_Instance
3405 ("subprogram used in renaming_as_body cannot be intrinsic",
3410 Insert_After (N, B_Node);
3414 end Check_Frozen_Renaming;
3416 -------------------------------
3417 -- Set_Entity_Or_Discriminal --
3418 -------------------------------
3420 procedure Set_Entity_Or_Discriminal (N : Node_Id; E : Entity_Id) is
3424 -- If the entity is not a discriminant, or else expansion is disabled,
3425 -- simply set the entity.
3427 if not In_Spec_Expression
3428 or else Ekind (E) /= E_Discriminant
3429 or else Inside_A_Generic
3431 Set_Entity_With_Style_Check (N, E);
3433 -- The replacement of a discriminant by the corresponding discriminal
3434 -- is not done for a task discriminant that appears in a default
3435 -- expression of an entry parameter. See Exp_Ch2.Expand_Discriminant
3436 -- for details on their handling.
3438 elsif Is_Concurrent_Type (Scope (E)) then
3442 and then not Nkind_In (P, N_Parameter_Specification,
3443 N_Component_Declaration)
3449 and then Nkind (P) = N_Parameter_Specification
3454 Set_Entity (N, Discriminal (E));
3457 -- Otherwise, this is a discriminant in a context in which
3458 -- it is a reference to the corresponding parameter of the
3459 -- init proc for the enclosing type.
3462 Set_Entity (N, Discriminal (E));
3464 end Set_Entity_Or_Discriminal;
3466 -----------------------------------
3467 -- Check_In_Previous_With_Clause --
3468 -----------------------------------
3470 procedure Check_In_Previous_With_Clause
3474 Pack : constant Entity_Id := Entity (Original_Node (Nam));
3479 Item := First (Context_Items (Parent (N)));
3481 while Present (Item)
3484 if Nkind (Item) = N_With_Clause
3486 -- Protect the frontend against previous critical errors
3488 and then Nkind (Name (Item)) /= N_Selected_Component
3489 and then Entity (Name (Item)) = Pack
3493 -- Find root library unit in with_clause
3495 while Nkind (Par) = N_Expanded_Name loop
3496 Par := Prefix (Par);
3499 if Is_Child_Unit (Entity (Original_Node (Par))) then
3500 Error_Msg_NE ("& is not directly visible", Par, Entity (Par));
3509 -- On exit, package is not mentioned in a previous with_clause.
3510 -- Check if its prefix is.
3512 if Nkind (Nam) = N_Expanded_Name then
3513 Check_In_Previous_With_Clause (N, Prefix (Nam));
3515 elsif Pack /= Any_Id then
3516 Error_Msg_NE ("& is not visible", Nam, Pack);
3518 end Check_In_Previous_With_Clause;
3520 ---------------------------------
3521 -- Check_Library_Unit_Renaming --
3522 ---------------------------------
3524 procedure Check_Library_Unit_Renaming (N : Node_Id; Old_E : Entity_Id) is
3528 if Nkind (Parent (N)) /= N_Compilation_Unit then
3531 -- Check for library unit. Note that we used to check for the scope
3532 -- being Standard here, but that was wrong for Standard itself.
3534 elsif not Is_Compilation_Unit (Old_E)
3535 and then not Is_Child_Unit (Old_E)
3537 Error_Msg_N ("renamed unit must be a library unit", Name (N));
3539 -- Entities defined in Standard (operators and boolean literals) cannot
3540 -- be renamed as library units.
3542 elsif Scope (Old_E) = Standard_Standard
3543 and then Sloc (Old_E) = Standard_Location
3545 Error_Msg_N ("renamed unit must be a library unit", Name (N));
3547 elsif Present (Parent_Spec (N))
3548 and then Nkind (Unit (Parent_Spec (N))) = N_Generic_Package_Declaration
3549 and then not Is_Child_Unit (Old_E)
3552 ("renamed unit must be a child unit of generic parent", Name (N));
3554 elsif Nkind (N) in N_Generic_Renaming_Declaration
3555 and then Nkind (Name (N)) = N_Expanded_Name
3556 and then Is_Generic_Instance (Entity (Prefix (Name (N))))
3557 and then Is_Generic_Unit (Old_E)
3560 ("renamed generic unit must be a library unit", Name (N));
3562 elsif Is_Package_Or_Generic_Package (Old_E) then
3564 -- Inherit categorization flags
3566 New_E := Defining_Entity (N);
3567 Set_Is_Pure (New_E, Is_Pure (Old_E));
3568 Set_Is_Preelaborated (New_E, Is_Preelaborated (Old_E));
3569 Set_Is_Remote_Call_Interface (New_E,
3570 Is_Remote_Call_Interface (Old_E));
3571 Set_Is_Remote_Types (New_E, Is_Remote_Types (Old_E));
3572 Set_Is_Shared_Passive (New_E, Is_Shared_Passive (Old_E));
3574 end Check_Library_Unit_Renaming;
3580 procedure End_Scope is
3586 Id := First_Entity (Current_Scope);
3587 while Present (Id) loop
3588 -- An entity in the current scope is not necessarily the first one
3589 -- on its homonym chain. Find its predecessor if any,
3590 -- If it is an internal entity, it will not be in the visibility
3591 -- chain altogether, and there is nothing to unchain.
3593 if Id /= Current_Entity (Id) then
3594 Prev := Current_Entity (Id);
3595 while Present (Prev)
3596 and then Present (Homonym (Prev))
3597 and then Homonym (Prev) /= Id
3599 Prev := Homonym (Prev);
3602 -- Skip to end of loop if Id is not in the visibility chain
3604 if No (Prev) or else Homonym (Prev) /= Id then
3612 Set_Is_Immediately_Visible (Id, False);
3614 Outer := Homonym (Id);
3615 while Present (Outer) and then Scope (Outer) = Current_Scope loop
3616 Outer := Homonym (Outer);
3619 -- Reset homonym link of other entities, but do not modify link
3620 -- between entities in current scope, so that the back-end can have
3621 -- a proper count of local overloadings.
3624 Set_Name_Entity_Id (Chars (Id), Outer);
3626 elsif Scope (Prev) /= Scope (Id) then
3627 Set_Homonym (Prev, Outer);
3634 -- If the scope generated freeze actions, place them before the
3635 -- current declaration and analyze them. Type declarations and
3636 -- the bodies of initialization procedures can generate such nodes.
3637 -- We follow the parent chain until we reach a list node, which is
3638 -- the enclosing list of declarations. If the list appears within
3639 -- a protected definition, move freeze nodes outside the protected
3643 (Scope_Stack.Table (Scope_Stack.Last).Pending_Freeze_Actions)
3647 L : constant List_Id := Scope_Stack.Table
3648 (Scope_Stack.Last).Pending_Freeze_Actions;
3651 if Is_Itype (Current_Scope) then
3652 Decl := Associated_Node_For_Itype (Current_Scope);
3654 Decl := Parent (Current_Scope);
3659 while not (Is_List_Member (Decl))
3660 or else Nkind_In (Parent (Decl), N_Protected_Definition,
3663 Decl := Parent (Decl);
3666 Insert_List_Before_And_Analyze (Decl, L);
3675 ---------------------
3676 -- End_Use_Clauses --
3677 ---------------------
3679 procedure End_Use_Clauses (Clause : Node_Id) is
3683 -- Remove Use_Type clauses first, because they affect the
3684 -- visibility of operators in subsequent used packages.
3687 while Present (U) loop
3688 if Nkind (U) = N_Use_Type_Clause then
3692 Next_Use_Clause (U);
3696 while Present (U) loop
3697 if Nkind (U) = N_Use_Package_Clause then
3698 End_Use_Package (U);
3701 Next_Use_Clause (U);
3703 end End_Use_Clauses;
3705 ---------------------
3706 -- End_Use_Package --
3707 ---------------------
3709 procedure End_Use_Package (N : Node_Id) is
3710 Pack_Name : Node_Id;
3715 function Is_Primitive_Operator_In_Use
3717 F : Entity_Id) return Boolean;
3718 -- Check whether Op is a primitive operator of a use-visible type
3720 ----------------------------------
3721 -- Is_Primitive_Operator_In_Use --
3722 ----------------------------------
3724 function Is_Primitive_Operator_In_Use
3726 F : Entity_Id) return Boolean
3728 T : constant Entity_Id := Base_Type (Etype (F));
3730 return In_Use (T) and then Scope (T) = Scope (Op);
3731 end Is_Primitive_Operator_In_Use;
3733 -- Start of processing for End_Use_Package
3736 Pack_Name := First (Names (N));
3737 while Present (Pack_Name) loop
3739 -- Test that Pack_Name actually denotes a package before processing
3741 if Is_Entity_Name (Pack_Name)
3742 and then Ekind (Entity (Pack_Name)) = E_Package
3744 Pack := Entity (Pack_Name);
3746 if In_Open_Scopes (Pack) then
3749 elsif not Redundant_Use (Pack_Name) then
3750 Set_In_Use (Pack, False);
3751 Set_Current_Use_Clause (Pack, Empty);
3753 Id := First_Entity (Pack);
3754 while Present (Id) loop
3756 -- Preserve use-visibility of operators that are primitive
3757 -- operators of a type that is use-visible through an active
3760 if Nkind (Id) = N_Defining_Operator_Symbol
3762 (Is_Primitive_Operator_In_Use
3763 (Id, First_Formal (Id))
3765 (Present (Next_Formal (First_Formal (Id)))
3767 Is_Primitive_Operator_In_Use
3768 (Id, Next_Formal (First_Formal (Id)))))
3773 Set_Is_Potentially_Use_Visible (Id, False);
3776 if Is_Private_Type (Id)
3777 and then Present (Full_View (Id))
3779 Set_Is_Potentially_Use_Visible (Full_View (Id), False);
3785 if Present (Renamed_Object (Pack)) then
3786 Set_In_Use (Renamed_Object (Pack), False);
3787 Set_Current_Use_Clause (Renamed_Object (Pack), Empty);
3790 if Chars (Pack) = Name_System
3791 and then Scope (Pack) = Standard_Standard
3792 and then Present_System_Aux
3794 Id := First_Entity (System_Aux_Id);
3795 while Present (Id) loop
3796 Set_Is_Potentially_Use_Visible (Id, False);
3798 if Is_Private_Type (Id)
3799 and then Present (Full_View (Id))
3801 Set_Is_Potentially_Use_Visible (Full_View (Id), False);
3807 Set_In_Use (System_Aux_Id, False);
3811 Set_Redundant_Use (Pack_Name, False);
3818 if Present (Hidden_By_Use_Clause (N)) then
3819 Elmt := First_Elmt (Hidden_By_Use_Clause (N));
3820 while Present (Elmt) loop
3822 E : constant Entity_Id := Node (Elmt);
3825 -- Reset either Use_Visibility or Direct_Visibility, depending
3826 -- on how the entity was hidden by the use clause.
3828 if In_Use (Scope (E))
3829 and then Used_As_Generic_Actual (Scope (E))
3831 Set_Is_Potentially_Use_Visible (Node (Elmt));
3833 Set_Is_Immediately_Visible (Node (Elmt));
3840 Set_Hidden_By_Use_Clause (N, No_Elist);
3842 end End_Use_Package;
3848 procedure End_Use_Type (N : Node_Id) is
3853 -- Start of processing for End_Use_Type
3856 Id := First (Subtype_Marks (N));
3857 while Present (Id) loop
3859 -- A call to Rtsfind may occur while analyzing a use_type clause,
3860 -- in which case the type marks are not resolved yet, and there is
3861 -- nothing to remove.
3863 if not Is_Entity_Name (Id) or else No (Entity (Id)) then
3869 if T = Any_Type or else From_With_Type (T) then
3872 -- Note that the use_type clause may mention a subtype of the type
3873 -- whose primitive operations have been made visible. Here as
3874 -- elsewhere, it is the base type that matters for visibility.
3876 elsif In_Open_Scopes (Scope (Base_Type (T))) then
3879 elsif not Redundant_Use (Id) then
3880 Set_In_Use (T, False);
3881 Set_In_Use (Base_Type (T), False);
3882 Set_Current_Use_Clause (T, Empty);
3883 Set_Current_Use_Clause (Base_Type (T), Empty);
3890 if Is_Empty_Elmt_List (Used_Operations (N)) then
3894 Elmt := First_Elmt (Used_Operations (N));
3895 while Present (Elmt) loop
3896 Set_Is_Potentially_Use_Visible (Node (Elmt), False);
3902 ----------------------
3903 -- Find_Direct_Name --
3904 ----------------------
3906 procedure Find_Direct_Name (N : Node_Id) is
3911 Inst : Entity_Id := Empty;
3912 -- Enclosing instance, if any
3914 Homonyms : Entity_Id;
3915 -- Saves start of homonym chain
3917 Nvis_Entity : Boolean;
3918 -- Set True to indicate that there is at least one entity on the homonym
3919 -- chain which, while not visible, is visible enough from the user point
3920 -- of view to warrant an error message of "not visible" rather than
3923 Nvis_Is_Private_Subprg : Boolean := False;
3924 -- Ada 2005 (AI-262): Set True to indicate that a form of Beaujolais
3925 -- effect concerning library subprograms has been detected. Used to
3926 -- generate the precise error message.
3928 function From_Actual_Package (E : Entity_Id) return Boolean;
3929 -- Returns true if the entity is declared in a package that is
3930 -- an actual for a formal package of the current instance. Such an
3931 -- entity requires special handling because it may be use-visible
3932 -- but hides directly visible entities defined outside the instance.
3934 function Is_Actual_Parameter return Boolean;
3935 -- This function checks if the node N is an identifier that is an actual
3936 -- parameter of a procedure call. If so it returns True, otherwise it
3937 -- return False. The reason for this check is that at this stage we do
3938 -- not know what procedure is being called if the procedure might be
3939 -- overloaded, so it is premature to go setting referenced flags or
3940 -- making calls to Generate_Reference. We will wait till Resolve_Actuals
3941 -- for that processing
3943 function Known_But_Invisible (E : Entity_Id) return Boolean;
3944 -- This function determines whether the entity E (which is not
3945 -- visible) can reasonably be considered to be known to the writer
3946 -- of the reference. This is a heuristic test, used only for the
3947 -- purposes of figuring out whether we prefer to complain that an
3948 -- entity is undefined or invisible (and identify the declaration
3949 -- of the invisible entity in the latter case). The point here is
3950 -- that we don't want to complain that something is invisible and
3951 -- then point to something entirely mysterious to the writer.
3953 procedure Nvis_Messages;
3954 -- Called if there are no visible entries for N, but there is at least
3955 -- one non-directly visible, or hidden declaration. This procedure
3956 -- outputs an appropriate set of error messages.
3958 procedure Undefined (Nvis : Boolean);
3959 -- This function is called if the current node has no corresponding
3960 -- visible entity or entities. The value set in Msg indicates whether
3961 -- an error message was generated (multiple error messages for the
3962 -- same variable are generally suppressed, see body for details).
3963 -- Msg is True if an error message was generated, False if not. This
3964 -- value is used by the caller to determine whether or not to output
3965 -- additional messages where appropriate. The parameter is set False
3966 -- to get the message "X is undefined", and True to get the message
3967 -- "X is not visible".
3969 -------------------------
3970 -- From_Actual_Package --
3971 -------------------------
3973 function From_Actual_Package (E : Entity_Id) return Boolean is
3974 Scop : constant Entity_Id := Scope (E);
3978 if not In_Instance then
3981 Inst := Current_Scope;
3982 while Present (Inst)
3983 and then Ekind (Inst) /= E_Package
3984 and then not Is_Generic_Instance (Inst)
3986 Inst := Scope (Inst);
3993 Act := First_Entity (Inst);
3994 while Present (Act) loop
3995 if Ekind (Act) = E_Package then
3997 -- Check for end of actuals list
3999 if Renamed_Object (Act) = Inst then
4002 elsif Present (Associated_Formal_Package (Act))
4003 and then Renamed_Object (Act) = Scop
4005 -- Entity comes from (instance of) formal package
4020 end From_Actual_Package;
4022 -------------------------
4023 -- Is_Actual_Parameter --
4024 -------------------------
4026 function Is_Actual_Parameter return Boolean is
4029 Nkind (N) = N_Identifier
4031 (Nkind (Parent (N)) = N_Procedure_Call_Statement
4033 (Nkind (Parent (N)) = N_Parameter_Association
4034 and then N = Explicit_Actual_Parameter (Parent (N))
4035 and then Nkind (Parent (Parent (N))) =
4036 N_Procedure_Call_Statement));
4037 end Is_Actual_Parameter;
4039 -------------------------
4040 -- Known_But_Invisible --
4041 -------------------------
4043 function Known_But_Invisible (E : Entity_Id) return Boolean is
4044 Fname : File_Name_Type;
4047 -- Entities in Standard are always considered to be known
4049 if Sloc (E) <= Standard_Location then
4052 -- An entity that does not come from source is always considered
4053 -- to be unknown, since it is an artifact of code expansion.
4055 elsif not Comes_From_Source (E) then
4058 -- In gnat internal mode, we consider all entities known
4060 elsif GNAT_Mode then
4064 -- Here we have an entity that is not from package Standard, and
4065 -- which comes from Source. See if it comes from an internal file.
4067 Fname := Unit_File_Name (Get_Source_Unit (E));
4069 -- Case of from internal file
4071 if Is_Internal_File_Name (Fname) then
4073 -- Private part entities in internal files are never considered
4074 -- to be known to the writer of normal application code.
4076 if Is_Hidden (E) then
4080 -- Entities from System packages other than System and
4081 -- System.Storage_Elements are not considered to be known.
4082 -- System.Auxxxx files are also considered known to the user.
4084 -- Should refine this at some point to generally distinguish
4085 -- between known and unknown internal files ???
4087 Get_Name_String (Fname);
4092 Name_Buffer (1 .. 2) /= "s-"
4094 Name_Buffer (3 .. 8) = "stoele"
4096 Name_Buffer (3 .. 5) = "aux";
4098 -- If not an internal file, then entity is definitely known,
4099 -- even if it is in a private part (the message generated will
4100 -- note that it is in a private part)
4105 end Known_But_Invisible;
4111 procedure Nvis_Messages is
4112 Comp_Unit : Node_Id;
4114 Found : Boolean := False;
4115 Hidden : Boolean := False;
4119 -- Ada 2005 (AI-262): Generate a precise error concerning the
4120 -- Beaujolais effect that was previously detected
4122 if Nvis_Is_Private_Subprg then
4124 pragma Assert (Nkind (E2) = N_Defining_Identifier
4125 and then Ekind (E2) = E_Function
4126 and then Scope (E2) = Standard_Standard
4127 and then Has_Private_With (E2));
4129 -- Find the sloc corresponding to the private with'ed unit
4131 Comp_Unit := Cunit (Current_Sem_Unit);
4132 Error_Msg_Sloc := No_Location;
4134 Item := First (Context_Items (Comp_Unit));
4135 while Present (Item) loop
4136 if Nkind (Item) = N_With_Clause
4137 and then Private_Present (Item)
4138 and then Entity (Name (Item)) = E2
4140 Error_Msg_Sloc := Sloc (Item);
4147 pragma Assert (Error_Msg_Sloc /= No_Location);
4149 Error_Msg_N ("(Ada 2005): hidden by private with clause #", N);
4153 Undefined (Nvis => True);
4157 -- First loop does hidden declarations
4160 while Present (Ent) loop
4161 if Is_Potentially_Use_Visible (Ent) then
4163 Error_Msg_N -- CODEFIX
4164 ("multiple use clauses cause hiding!", N);
4168 Error_Msg_Sloc := Sloc (Ent);
4169 Error_Msg_N -- CODEFIX
4170 ("hidden declaration#!", N);
4173 Ent := Homonym (Ent);
4176 -- If we found hidden declarations, then that's enough, don't
4177 -- bother looking for non-visible declarations as well.
4183 -- Second loop does non-directly visible declarations
4186 while Present (Ent) loop
4187 if not Is_Potentially_Use_Visible (Ent) then
4189 -- Do not bother the user with unknown entities
4191 if not Known_But_Invisible (Ent) then
4195 Error_Msg_Sloc := Sloc (Ent);
4197 -- Output message noting that there is a non-visible
4198 -- declaration, distinguishing the private part case.
4200 if Is_Hidden (Ent) then
4201 Error_Msg_N ("non-visible (private) declaration#!", N);
4203 -- If the entity is declared in a generic package, it
4204 -- cannot be visible, so there is no point in adding it
4205 -- to the list of candidates if another homograph from a
4206 -- non-generic package has been seen.
4208 elsif Ekind (Scope (Ent)) = E_Generic_Package
4214 Error_Msg_N -- CODEFIX
4215 ("non-visible declaration#!", N);
4217 if Ekind (Scope (Ent)) /= E_Generic_Package then
4221 if Is_Compilation_Unit (Ent)
4223 Nkind (Parent (Parent (N))) = N_Use_Package_Clause
4225 Error_Msg_Qual_Level := 99;
4226 Error_Msg_NE -- CODEFIX
4227 ("\\missing `WITH &;`", N, Ent);
4228 Error_Msg_Qual_Level := 0;
4231 if Ekind (Ent) = E_Discriminant
4232 and then Present (Corresponding_Discriminant (Ent))
4233 and then Scope (Corresponding_Discriminant (Ent)) =
4237 ("inherited discriminant not allowed here" &
4238 " (RM 3.8 (12), 3.8.1 (6))!", N);
4242 -- Set entity and its containing package as referenced. We
4243 -- can't be sure of this, but this seems a better choice
4244 -- to avoid unused entity messages.
4246 if Comes_From_Source (Ent) then
4247 Set_Referenced (Ent);
4248 Set_Referenced (Cunit_Entity (Get_Source_Unit (Ent)));
4253 Ent := Homonym (Ent);
4262 procedure Undefined (Nvis : Boolean) is
4263 Emsg : Error_Msg_Id;
4266 -- We should never find an undefined internal name. If we do, then
4267 -- see if we have previous errors. If so, ignore on the grounds that
4268 -- it is probably a cascaded message (e.g. a block label from a badly
4269 -- formed block). If no previous errors, then we have a real internal
4270 -- error of some kind so raise an exception.
4272 if Is_Internal_Name (Chars (N)) then
4273 if Total_Errors_Detected /= 0 then
4276 raise Program_Error;
4280 -- A very specialized error check, if the undefined variable is
4281 -- a case tag, and the case type is an enumeration type, check
4282 -- for a possible misspelling, and if so, modify the identifier
4284 -- Named aggregate should also be handled similarly ???
4286 if Nkind (N) = N_Identifier
4287 and then Nkind (Parent (N)) = N_Case_Statement_Alternative
4290 Case_Stm : constant Node_Id := Parent (Parent (N));
4291 Case_Typ : constant Entity_Id := Etype (Expression (Case_Stm));
4296 if Is_Enumeration_Type (Case_Typ)
4297 and then not Is_Standard_Character_Type (Case_Typ)
4299 Lit := First_Literal (Case_Typ);
4300 Get_Name_String (Chars (Lit));
4302 if Chars (Lit) /= Chars (N)
4303 and then Is_Bad_Spelling_Of (Chars (N), Chars (Lit)) then
4304 Error_Msg_Node_2 := Lit;
4305 Error_Msg_N -- CODEFIX
4306 ("& is undefined, assume misspelling of &", N);
4307 Rewrite (N, New_Occurrence_Of (Lit, Sloc (N)));
4311 Lit := Next_Literal (Lit);
4316 -- Normal processing
4318 Set_Entity (N, Any_Id);
4319 Set_Etype (N, Any_Type);
4321 -- We use the table Urefs to keep track of entities for which we
4322 -- have issued errors for undefined references. Multiple errors
4323 -- for a single name are normally suppressed, however we modify
4324 -- the error message to alert the programmer to this effect.
4326 for J in Urefs.First .. Urefs.Last loop
4327 if Chars (N) = Chars (Urefs.Table (J).Node) then
4328 if Urefs.Table (J).Err /= No_Error_Msg
4329 and then Sloc (N) /= Urefs.Table (J).Loc
4331 Error_Msg_Node_1 := Urefs.Table (J).Node;
4333 if Urefs.Table (J).Nvis then
4334 Change_Error_Text (Urefs.Table (J).Err,
4335 "& is not visible (more references follow)");
4337 Change_Error_Text (Urefs.Table (J).Err,
4338 "& is undefined (more references follow)");
4341 Urefs.Table (J).Err := No_Error_Msg;
4344 -- Although we will set Msg False, and thus suppress the
4345 -- message, we also set Error_Posted True, to avoid any
4346 -- cascaded messages resulting from the undefined reference.
4349 Set_Error_Posted (N, True);
4354 -- If entry not found, this is first undefined occurrence
4357 Error_Msg_N ("& is not visible!", N);
4361 Error_Msg_N ("& is undefined!", N);
4364 -- A very bizarre special check, if the undefined identifier
4365 -- is put or put_line, then add a special error message (since
4366 -- this is a very common error for beginners to make).
4368 if Chars (N) = Name_Put or else Chars (N) = Name_Put_Line then
4369 Error_Msg_N -- CODEFIX
4370 ("\\possible missing `WITH Ada.Text_'I'O; " &
4371 "USE Ada.Text_'I'O`!", N);
4373 -- Another special check if N is the prefix of a selected
4374 -- component which is a known unit, add message complaining
4375 -- about missing with for this unit.
4377 elsif Nkind (Parent (N)) = N_Selected_Component
4378 and then N = Prefix (Parent (N))
4379 and then Is_Known_Unit (Parent (N))
4381 Error_Msg_Node_2 := Selector_Name (Parent (N));
4382 Error_Msg_N -- CODEFIX
4383 ("\\missing `WITH &.&;`", Prefix (Parent (N)));
4386 -- Now check for possible misspellings
4390 Ematch : Entity_Id := Empty;
4392 Last_Name_Id : constant Name_Id :=
4393 Name_Id (Nat (First_Name_Id) +
4394 Name_Entries_Count - 1);
4397 for Nam in First_Name_Id .. Last_Name_Id loop
4398 E := Get_Name_Entity_Id (Nam);
4401 and then (Is_Immediately_Visible (E)
4403 Is_Potentially_Use_Visible (E))
4405 if Is_Bad_Spelling_Of (Chars (N), Nam) then
4412 if Present (Ematch) then
4413 Error_Msg_NE -- CODEFIX
4414 ("\possible misspelling of&", N, Ematch);
4419 -- Make entry in undefined references table unless the full errors
4420 -- switch is set, in which case by refraining from generating the
4421 -- table entry, we guarantee that we get an error message for every
4422 -- undefined reference.
4424 if not All_Errors_Mode then
4435 -- Start of processing for Find_Direct_Name
4438 -- If the entity pointer is already set, this is an internal node, or
4439 -- a node that is analyzed more than once, after a tree modification.
4440 -- In such a case there is no resolution to perform, just set the type.
4442 if Present (Entity (N)) then
4443 if Is_Type (Entity (N)) then
4444 Set_Etype (N, Entity (N));
4448 Entyp : constant Entity_Id := Etype (Entity (N));
4451 -- One special case here. If the Etype field is already set,
4452 -- and references the packed array type corresponding to the
4453 -- etype of the referenced entity, then leave it alone. This
4454 -- happens for trees generated from Exp_Pakd, where expressions
4455 -- can be deliberately "mis-typed" to the packed array type.
4457 if Is_Array_Type (Entyp)
4458 and then Is_Packed (Entyp)
4459 and then Present (Etype (N))
4460 and then Etype (N) = Packed_Array_Type (Entyp)
4464 -- If not that special case, then just reset the Etype
4467 Set_Etype (N, Etype (Entity (N)));
4475 -- Here if Entity pointer was not set, we need full visibility analysis
4476 -- First we generate debugging output if the debug E flag is set.
4478 if Debug_Flag_E then
4479 Write_Str ("Looking for ");
4480 Write_Name (Chars (N));
4484 Homonyms := Current_Entity (N);
4485 Nvis_Entity := False;
4488 while Present (E) loop
4490 -- If entity is immediately visible or potentially use visible, then
4491 -- process the entity and we are done.
4493 if Is_Immediately_Visible (E) then
4494 goto Immediately_Visible_Entity;
4496 elsif Is_Potentially_Use_Visible (E) then
4497 goto Potentially_Use_Visible_Entity;
4499 -- Note if a known but invisible entity encountered
4501 elsif Known_But_Invisible (E) then
4502 Nvis_Entity := True;
4505 -- Move to next entity in chain and continue search
4510 -- If no entries on homonym chain that were potentially visible,
4511 -- and no entities reasonably considered as non-visible, then
4512 -- we have a plain undefined reference, with no additional
4513 -- explanation required!
4515 if not Nvis_Entity then
4516 Undefined (Nvis => False);
4518 -- Otherwise there is at least one entry on the homonym chain that
4519 -- is reasonably considered as being known and non-visible.
4527 -- Processing for a potentially use visible entry found. We must search
4528 -- the rest of the homonym chain for two reasons. First, if there is a
4529 -- directly visible entry, then none of the potentially use-visible
4530 -- entities are directly visible (RM 8.4(10)). Second, we need to check
4531 -- for the case of multiple potentially use-visible entries hiding one
4532 -- another and as a result being non-directly visible (RM 8.4(11)).
4534 <<Potentially_Use_Visible_Entity>> declare
4535 Only_One_Visible : Boolean := True;
4536 All_Overloadable : Boolean := Is_Overloadable (E);
4540 while Present (E2) loop
4541 if Is_Immediately_Visible (E2) then
4543 -- If the use-visible entity comes from the actual for a
4544 -- formal package, it hides a directly visible entity from
4545 -- outside the instance.
4547 if From_Actual_Package (E)
4548 and then Scope_Depth (E2) < Scope_Depth (Inst)
4553 goto Immediately_Visible_Entity;
4556 elsif Is_Potentially_Use_Visible (E2) then
4557 Only_One_Visible := False;
4558 All_Overloadable := All_Overloadable and Is_Overloadable (E2);
4560 -- Ada 2005 (AI-262): Protect against a form of Beaujolais effect
4561 -- that can occur in private_with clauses. Example:
4564 -- private with B; package A is
4565 -- package C is function B return Integer;
4567 -- V1 : Integer := B;
4568 -- private function B return Integer;
4569 -- V2 : Integer := B;
4572 -- V1 resolves to A.B, but V2 resolves to library unit B
4574 elsif Ekind (E2) = E_Function
4575 and then Scope (E2) = Standard_Standard
4576 and then Has_Private_With (E2)
4578 Only_One_Visible := False;
4579 All_Overloadable := False;
4580 Nvis_Is_Private_Subprg := True;
4587 -- On falling through this loop, we have checked that there are no
4588 -- immediately visible entities. Only_One_Visible is set if exactly
4589 -- one potentially use visible entity exists. All_Overloadable is
4590 -- set if all the potentially use visible entities are overloadable.
4591 -- The condition for legality is that either there is one potentially
4592 -- use visible entity, or if there is more than one, then all of them
4593 -- are overloadable.
4595 if Only_One_Visible or All_Overloadable then
4598 -- If there is more than one potentially use-visible entity and at
4599 -- least one of them non-overloadable, we have an error (RM 8.4(11).
4600 -- Note that E points to the first such entity on the homonym list.
4601 -- Special case: if one of the entities is declared in an actual
4602 -- package, it was visible in the generic, and takes precedence over
4603 -- other entities that are potentially use-visible. Same if it is
4604 -- declared in a local instantiation of the current instance.
4609 -- Find current instance
4611 Inst := Current_Scope;
4612 while Present (Inst)
4613 and then Inst /= Standard_Standard
4615 if Is_Generic_Instance (Inst) then
4619 Inst := Scope (Inst);
4623 while Present (E2) loop
4624 if From_Actual_Package (E2)
4626 (Is_Generic_Instance (Scope (E2))
4627 and then Scope_Depth (Scope (E2)) > Scope_Depth (Inst))
4640 Is_Predefined_File_Name (Unit_File_Name (Current_Sem_Unit))
4642 -- A use-clause in the body of a system file creates conflict
4643 -- with some entity in a user scope, while rtsfind is active.
4644 -- Keep only the entity coming from another predefined unit.
4647 while Present (E2) loop
4648 if Is_Predefined_File_Name
4649 (Unit_File_Name (Get_Source_Unit (Sloc (E2))))
4658 -- Entity must exist because predefined unit is correct
4660 raise Program_Error;
4669 -- Come here with E set to the first immediately visible entity on
4670 -- the homonym chain. This is the one we want unless there is another
4671 -- immediately visible entity further on in the chain for an inner
4672 -- scope (RM 8.3(8)).
4674 <<Immediately_Visible_Entity>> declare
4679 -- Find scope level of initial entity. When compiling through
4680 -- Rtsfind, the previous context is not completely invisible, and
4681 -- an outer entity may appear on the chain, whose scope is below
4682 -- the entry for Standard that delimits the current scope stack.
4683 -- Indicate that the level for this spurious entry is outside of
4684 -- the current scope stack.
4686 Level := Scope_Stack.Last;
4688 Scop := Scope_Stack.Table (Level).Entity;
4689 exit when Scop = Scope (E);
4691 exit when Scop = Standard_Standard;
4694 -- Now search remainder of homonym chain for more inner entry
4695 -- If the entity is Standard itself, it has no scope, and we
4696 -- compare it with the stack entry directly.
4699 while Present (E2) loop
4700 if Is_Immediately_Visible (E2) then
4702 -- If a generic package contains a local declaration that
4703 -- has the same name as the generic, there may be a visibility
4704 -- conflict in an instance, where the local declaration must
4705 -- also hide the name of the corresponding package renaming.
4706 -- We check explicitly for a package declared by a renaming,
4707 -- whose renamed entity is an instance that is on the scope
4708 -- stack, and that contains a homonym in the same scope. Once
4709 -- we have found it, we know that the package renaming is not
4710 -- immediately visible, and that the identifier denotes the
4711 -- other entity (and its homonyms if overloaded).
4713 if Scope (E) = Scope (E2)
4714 and then Ekind (E) = E_Package
4715 and then Present (Renamed_Object (E))
4716 and then Is_Generic_Instance (Renamed_Object (E))
4717 and then In_Open_Scopes (Renamed_Object (E))
4718 and then Comes_From_Source (N)
4720 Set_Is_Immediately_Visible (E, False);
4724 for J in Level + 1 .. Scope_Stack.Last loop
4725 if Scope_Stack.Table (J).Entity = Scope (E2)
4726 or else Scope_Stack.Table (J).Entity = E2
4739 -- At the end of that loop, E is the innermost immediately
4740 -- visible entity, so we are all set.
4743 -- Come here with entity found, and stored in E
4747 -- Check violation of No_Wide_Characters restriction
4749 Check_Wide_Character_Restriction (E, N);
4751 -- When distribution features are available (Get_PCS_Name /=
4752 -- Name_No_DSA), a remote access-to-subprogram type is converted
4753 -- into a record type holding whatever information is needed to
4754 -- perform a remote call on an RCI subprogram. In that case we
4755 -- rewrite any occurrence of the RAS type into the equivalent record
4756 -- type here. 'Access attribute references and RAS dereferences are
4757 -- then implemented using specific TSSs. However when distribution is
4758 -- not available (case of Get_PCS_Name = Name_No_DSA), we bypass the
4759 -- generation of these TSSs, and we must keep the RAS type in its
4760 -- original access-to-subprogram form (since all calls through a
4761 -- value of such type will be local anyway in the absence of a PCS).
4763 if Comes_From_Source (N)
4764 and then Is_Remote_Access_To_Subprogram_Type (E)
4765 and then Expander_Active
4766 and then Get_PCS_Name /= Name_No_DSA
4769 New_Occurrence_Of (Equivalent_Type (E), Sloc (N)));
4773 -- Set the entity. Note that the reason we call Set_Entity for the
4774 -- overloadable case, as opposed to Set_Entity_With_Style_Check is
4775 -- that in the overloaded case, the initial call can set the wrong
4776 -- homonym. The call that sets the right homonym is in Sem_Res and
4777 -- that call does use Set_Entity_With_Style_Check, so we don't miss
4780 if Is_Overloadable (E) then
4783 Set_Entity_With_Style_Check (N, E);
4789 Set_Etype (N, Get_Full_View (Etype (E)));
4792 if Debug_Flag_E then
4793 Write_Str (" found ");
4794 Write_Entity_Info (E, " ");
4797 -- If the Ekind of the entity is Void, it means that all homonyms
4798 -- are hidden from all visibility (RM 8.3(5,14-20)). However, this
4799 -- test is skipped if the current scope is a record and the name is
4800 -- a pragma argument expression (case of Atomic and Volatile pragmas
4801 -- and possibly other similar pragmas added later, which are allowed
4802 -- to reference components in the current record).
4804 if Ekind (E) = E_Void
4806 (not Is_Record_Type (Current_Scope)
4807 or else Nkind (Parent (N)) /= N_Pragma_Argument_Association)
4809 Premature_Usage (N);
4811 -- If the entity is overloadable, collect all interpretations of the
4812 -- name for subsequent overload resolution. We optimize a bit here to
4813 -- do this only if we have an overloadable entity that is not on its
4814 -- own on the homonym chain.
4816 elsif Is_Overloadable (E)
4817 and then (Present (Homonym (E)) or else Current_Entity (N) /= E)
4819 Collect_Interps (N);
4821 -- If no homonyms were visible, the entity is unambiguous
4823 if not Is_Overloaded (N) then
4824 if not Is_Actual_Parameter then
4825 Generate_Reference (E, N);
4829 -- Case of non-overloadable entity, set the entity providing that
4830 -- we do not have the case of a discriminant reference within a
4831 -- default expression. Such references are replaced with the
4832 -- corresponding discriminal, which is the formal corresponding to
4833 -- to the discriminant in the initialization procedure.
4836 -- Entity is unambiguous, indicate that it is referenced here
4838 -- For a renaming of an object, always generate simple reference,
4839 -- we don't try to keep track of assignments in this case.
4841 if Is_Object (E) and then Present (Renamed_Object (E)) then
4842 Generate_Reference (E, N);
4844 -- If the renamed entity is a private protected component,
4845 -- reference the original component as well. This needs to be
4846 -- done because the private renamings are installed before any
4847 -- analysis has occurred. Reference to a private component will
4848 -- resolve to the renaming and the original component will be
4849 -- left unreferenced, hence the following.
4851 if Is_Prival (E) then
4852 Generate_Reference (Prival_Link (E), N);
4855 -- One odd case is that we do not want to set the Referenced flag
4856 -- if the entity is a label, and the identifier is the label in
4857 -- the source, since this is not a reference from the point of
4858 -- view of the user.
4860 elsif Nkind (Parent (N)) = N_Label then
4862 R : constant Boolean := Referenced (E);
4865 -- Generate reference unless this is an actual parameter
4866 -- (see comment below)
4868 if Is_Actual_Parameter then
4869 Generate_Reference (E, N);
4870 Set_Referenced (E, R);
4874 -- Normal case, not a label: generate reference
4876 -- ??? It is too early to generate a reference here even if the
4877 -- entity is unambiguous, because the tree is not sufficiently
4878 -- typed at this point for Generate_Reference to determine
4879 -- whether this reference modifies the denoted object (because
4880 -- implicit dereferences cannot be identified prior to full type
4883 -- The Is_Actual_Parameter routine takes care of one of these
4884 -- cases but there are others probably ???
4886 -- If the entity is the LHS of an assignment, and is a variable
4887 -- (rather than a package prefix), we can mark it as a
4888 -- modification right away, to avoid duplicate references.
4891 if not Is_Actual_Parameter then
4893 and then Ekind (E) /= E_Package
4894 and then Ekind (E) /= E_Generic_Package
4896 Generate_Reference (E, N, 'm');
4898 Generate_Reference (E, N);
4902 Check_Nested_Access (E);
4905 Set_Entity_Or_Discriminal (N, E);
4907 if Ada_Version >= Ada_2012
4909 (Nkind (Parent (N)) in N_Subexpr
4910 or else Nkind (Parent (N)) = N_Object_Declaration)
4912 Check_Implicit_Dereference (N, Etype (E));
4916 end Find_Direct_Name;
4918 ------------------------
4919 -- Find_Expanded_Name --
4920 ------------------------
4922 -- This routine searches the homonym chain of the entity until it finds
4923 -- an entity declared in the scope denoted by the prefix. If the entity
4924 -- is private, it may nevertheless be immediately visible, if we are in
4925 -- the scope of its declaration.
4927 procedure Find_Expanded_Name (N : Node_Id) is
4928 Selector : constant Node_Id := Selector_Name (N);
4929 Candidate : Entity_Id := Empty;
4935 P_Name := Entity (Prefix (N));
4938 -- If the prefix is a renamed package, look for the entity in the
4939 -- original package.
4941 if Ekind (P_Name) = E_Package
4942 and then Present (Renamed_Object (P_Name))
4944 P_Name := Renamed_Object (P_Name);
4946 -- Rewrite node with entity field pointing to renamed object
4948 Rewrite (Prefix (N), New_Copy (Prefix (N)));
4949 Set_Entity (Prefix (N), P_Name);
4951 -- If the prefix is an object of a concurrent type, look for
4952 -- the entity in the associated task or protected type.
4954 elsif Is_Concurrent_Type (Etype (P_Name)) then
4955 P_Name := Etype (P_Name);
4958 Id := Current_Entity (Selector);
4961 Is_New_Candidate : Boolean;
4964 while Present (Id) loop
4965 if Scope (Id) = P_Name then
4967 Is_New_Candidate := True;
4969 -- Ada 2005 (AI-217): Handle shadow entities associated with types
4970 -- declared in limited-withed nested packages. We don't need to
4971 -- handle E_Incomplete_Subtype entities because the entities in
4972 -- the limited view are always E_Incomplete_Type entities (see
4973 -- Build_Limited_Views). Regarding the expression used to evaluate
4974 -- the scope, it is important to note that the limited view also
4975 -- has shadow entities associated nested packages. For this reason
4976 -- the correct scope of the entity is the scope of the real entity
4977 -- The non-limited view may itself be incomplete, in which case
4978 -- get the full view if available.
4980 elsif From_With_Type (Id)
4981 and then Is_Type (Id)
4982 and then Ekind (Id) = E_Incomplete_Type
4983 and then Present (Non_Limited_View (Id))
4984 and then Scope (Non_Limited_View (Id)) = P_Name
4986 Candidate := Get_Full_View (Non_Limited_View (Id));
4987 Is_New_Candidate := True;
4990 Is_New_Candidate := False;
4993 if Is_New_Candidate then
4994 if Is_Child_Unit (Id) then
4995 exit when Is_Visible_Child_Unit (Id)
4996 or else Is_Immediately_Visible (Id);
4999 exit when not Is_Hidden (Id)
5000 or else Is_Immediately_Visible (Id);
5009 and then (Ekind (P_Name) = E_Procedure
5011 Ekind (P_Name) = E_Function)
5012 and then Is_Generic_Instance (P_Name)
5014 -- Expanded name denotes entity in (instance of) generic subprogram.
5015 -- The entity may be in the subprogram instance, or may denote one of
5016 -- the formals, which is declared in the enclosing wrapper package.
5018 P_Name := Scope (P_Name);
5020 Id := Current_Entity (Selector);
5021 while Present (Id) loop
5022 exit when Scope (Id) = P_Name;
5027 if No (Id) or else Chars (Id) /= Chars (Selector) then
5028 Set_Etype (N, Any_Type);
5030 -- If we are looking for an entity defined in System, try to find it
5031 -- in the child package that may have been provided as an extension
5032 -- to System. The Extend_System pragma will have supplied the name of
5033 -- the extension, which may have to be loaded.
5035 if Chars (P_Name) = Name_System
5036 and then Scope (P_Name) = Standard_Standard
5037 and then Present (System_Extend_Unit)
5038 and then Present_System_Aux (N)
5040 Set_Entity (Prefix (N), System_Aux_Id);
5041 Find_Expanded_Name (N);
5044 elsif Nkind (Selector) = N_Operator_Symbol
5045 and then Has_Implicit_Operator (N)
5047 -- There is an implicit instance of the predefined operator in
5048 -- the given scope. The operator entity is defined in Standard.
5049 -- Has_Implicit_Operator makes the node into an Expanded_Name.
5053 elsif Nkind (Selector) = N_Character_Literal
5054 and then Has_Implicit_Character_Literal (N)
5056 -- If there is no literal defined in the scope denoted by the
5057 -- prefix, the literal may belong to (a type derived from)
5058 -- Standard_Character, for which we have no explicit literals.
5063 -- If the prefix is a single concurrent object, use its name in
5064 -- the error message, rather than that of the anonymous type.
5066 if Is_Concurrent_Type (P_Name)
5067 and then Is_Internal_Name (Chars (P_Name))
5069 Error_Msg_Node_2 := Entity (Prefix (N));
5071 Error_Msg_Node_2 := P_Name;
5074 if P_Name = System_Aux_Id then
5075 P_Name := Scope (P_Name);
5076 Set_Entity (Prefix (N), P_Name);
5079 if Present (Candidate) then
5081 -- If we know that the unit is a child unit we can give a more
5082 -- accurate error message.
5084 if Is_Child_Unit (Candidate) then
5086 -- If the candidate is a private child unit and we are in
5087 -- the visible part of a public unit, specialize the error
5088 -- message. There might be a private with_clause for it,
5089 -- but it is not currently active.
5091 if Is_Private_Descendant (Candidate)
5092 and then Ekind (Current_Scope) = E_Package
5093 and then not In_Private_Part (Current_Scope)
5094 and then not Is_Private_Descendant (Current_Scope)
5096 Error_Msg_N ("private child unit& is not visible here",
5099 -- Normal case where we have a missing with for a child unit
5102 Error_Msg_Qual_Level := 99;
5103 Error_Msg_NE -- CODEFIX
5104 ("missing `WITH &;`", Selector, Candidate);
5105 Error_Msg_Qual_Level := 0;
5108 -- Here we don't know that this is a child unit
5111 Error_Msg_NE ("& is not a visible entity of&", N, Selector);
5115 -- Within the instantiation of a child unit, the prefix may
5116 -- denote the parent instance, but the selector has the name
5117 -- of the original child. Find whether we are within the
5118 -- corresponding instance, and get the proper entity, which
5119 -- can only be an enclosing scope.
5122 and then In_Open_Scopes (P_Name)
5123 and then Is_Generic_Instance (P_Name)
5126 S : Entity_Id := Current_Scope;
5130 for J in reverse 0 .. Scope_Stack.Last loop
5131 S := Scope_Stack.Table (J).Entity;
5133 exit when S = Standard_Standard;
5135 if Ekind_In (S, E_Function,
5139 P := Generic_Parent (Specification
5140 (Unit_Declaration_Node (S)));
5143 and then Chars (Scope (P)) = Chars (O_Name)
5144 and then Chars (P) = Chars (Selector)
5155 -- If this is a selection from Ada, System or Interfaces, then
5156 -- we assume a missing with for the corresponding package.
5158 if Is_Known_Unit (N) then
5159 if not Error_Posted (N) then
5160 Error_Msg_Node_2 := Selector;
5161 Error_Msg_N -- CODEFIX
5162 ("missing `WITH &.&;`", Prefix (N));
5165 -- If this is a selection from a dummy package, then suppress
5166 -- the error message, of course the entity is missing if the
5167 -- package is missing!
5169 elsif Sloc (Error_Msg_Node_2) = No_Location then
5172 -- Here we have the case of an undefined component
5176 -- The prefix may hide a homonym in the context that
5177 -- declares the desired entity. This error can use a
5178 -- specialized message.
5180 if In_Open_Scopes (P_Name)
5181 and then Present (Homonym (P_Name))
5182 and then Is_Compilation_Unit (Homonym (P_Name))
5184 (Is_Immediately_Visible (Homonym (P_Name))
5185 or else Is_Visible_Child_Unit (Homonym (P_Name)))
5188 H : constant Entity_Id := Homonym (P_Name);
5191 Id := First_Entity (H);
5192 while Present (Id) loop
5193 if Chars (Id) = Chars (Selector) then
5194 Error_Msg_Qual_Level := 99;
5195 Error_Msg_Name_1 := Chars (Selector);
5197 ("% not declared in&", N, P_Name);
5199 ("\use fully qualified name starting with"
5200 & " Standard to make& visible", N, H);
5201 Error_Msg_Qual_Level := 0;
5208 -- If not found, standard error message
5210 Error_Msg_NE ("& not declared in&", N, Selector);
5216 Error_Msg_NE ("& not declared in&", N, Selector);
5219 -- Check for misspelling of some entity in prefix
5221 Id := First_Entity (P_Name);
5222 while Present (Id) loop
5223 if Is_Bad_Spelling_Of (Chars (Id), Chars (Selector))
5224 and then not Is_Internal_Name (Chars (Id))
5226 Error_Msg_NE -- CODEFIX
5227 ("possible misspelling of&", Selector, Id);
5234 -- Specialize the message if this may be an instantiation
5235 -- of a child unit that was not mentioned in the context.
5237 if Nkind (Parent (N)) = N_Package_Instantiation
5238 and then Is_Generic_Instance (Entity (Prefix (N)))
5239 and then Is_Compilation_Unit
5240 (Generic_Parent (Parent (Entity (Prefix (N)))))
5242 Error_Msg_Node_2 := Selector;
5243 Error_Msg_N -- CODEFIX
5244 ("\missing `WITH &.&;`", Prefix (N));
5254 if Comes_From_Source (N)
5255 and then Is_Remote_Access_To_Subprogram_Type (Id)
5256 and then Present (Equivalent_Type (Id))
5258 -- If we are not actually generating distribution code (i.e. the
5259 -- current PCS is the dummy non-distributed version), then the
5260 -- Equivalent_Type will be missing, and Id should be treated as
5261 -- a regular access-to-subprogram type.
5263 Id := Equivalent_Type (Id);
5264 Set_Chars (Selector, Chars (Id));
5267 -- Ada 2005 (AI-50217): Check usage of entities in limited withed units
5269 if Ekind (P_Name) = E_Package
5270 and then From_With_Type (P_Name)
5272 if From_With_Type (Id)
5273 or else Is_Type (Id)
5274 or else Ekind (Id) = E_Package
5279 ("limited withed package can only be used to access "
5280 & "incomplete types",
5285 if Is_Task_Type (P_Name)
5286 and then ((Ekind (Id) = E_Entry
5287 and then Nkind (Parent (N)) /= N_Attribute_Reference)
5289 (Ekind (Id) = E_Entry_Family
5291 Nkind (Parent (Parent (N))) /= N_Attribute_Reference))
5293 -- It is an entry call after all, either to the current task (which
5294 -- will deadlock) or to an enclosing task.
5296 Analyze_Selected_Component (N);
5300 Change_Selected_Component_To_Expanded_Name (N);
5302 -- Do style check and generate reference, but skip both steps if this
5303 -- entity has homonyms, since we may not have the right homonym set yet.
5304 -- The proper homonym will be set during the resolve phase.
5306 if Has_Homonym (Id) then
5309 Set_Entity_Or_Discriminal (N, Id);
5312 Generate_Reference (Id, N, 'm');
5314 Generate_Reference (Id, N);
5318 if Is_Type (Id) then
5321 Set_Etype (N, Get_Full_View (Etype (Id)));
5324 -- Check for violation of No_Wide_Characters
5326 Check_Wide_Character_Restriction (Id, N);
5328 -- If the Ekind of the entity is Void, it means that all homonyms are
5329 -- hidden from all visibility (RM 8.3(5,14-20)).
5331 if Ekind (Id) = E_Void then
5332 Premature_Usage (N);
5334 elsif Is_Overloadable (Id)
5335 and then Present (Homonym (Id))
5338 H : Entity_Id := Homonym (Id);
5341 while Present (H) loop
5342 if Scope (H) = Scope (Id)
5345 or else Is_Immediately_Visible (H))
5347 Collect_Interps (N);
5354 -- If an extension of System is present, collect possible explicit
5355 -- overloadings declared in the extension.
5357 if Chars (P_Name) = Name_System
5358 and then Scope (P_Name) = Standard_Standard
5359 and then Present (System_Extend_Unit)
5360 and then Present_System_Aux (N)
5362 H := Current_Entity (Id);
5364 while Present (H) loop
5365 if Scope (H) = System_Aux_Id then
5366 Add_One_Interp (N, H, Etype (H));
5375 if Nkind (Selector_Name (N)) = N_Operator_Symbol
5376 and then Scope (Id) /= Standard_Standard
5378 -- In addition to user-defined operators in the given scope, there
5379 -- may be an implicit instance of the predefined operator. The
5380 -- operator (defined in Standard) is found in Has_Implicit_Operator,
5381 -- and added to the interpretations. Procedure Add_One_Interp will
5382 -- determine which hides which.
5384 if Has_Implicit_Operator (N) then
5388 end Find_Expanded_Name;
5390 -------------------------
5391 -- Find_Renamed_Entity --
5392 -------------------------
5394 function Find_Renamed_Entity
5398 Is_Actual : Boolean := False) return Entity_Id
5401 I1 : Interp_Index := 0; -- Suppress junk warnings
5407 function Enclosing_Instance return Entity_Id;
5408 -- If the renaming determines the entity for the default of a formal
5409 -- subprogram nested within another instance, choose the innermost
5410 -- candidate. This is because if the formal has a box, and we are within
5411 -- an enclosing instance where some candidate interpretations are local
5412 -- to this enclosing instance, we know that the default was properly
5413 -- resolved when analyzing the generic, so we prefer the local
5414 -- candidates to those that are external. This is not always the case
5415 -- but is a reasonable heuristic on the use of nested generics. The
5416 -- proper solution requires a full renaming model.
5418 function Is_Visible_Operation (Op : Entity_Id) return Boolean;
5419 -- If the renamed entity is an implicit operator, check whether it is
5420 -- visible because its operand type is properly visible. This check
5421 -- applies to explicit renamed entities that appear in the source in a
5422 -- renaming declaration or a formal subprogram instance, but not to
5423 -- default generic actuals with a name.
5425 function Report_Overload return Entity_Id;
5426 -- List possible interpretations, and specialize message in the
5427 -- case of a generic actual.
5429 function Within (Inner, Outer : Entity_Id) return Boolean;
5430 -- Determine whether a candidate subprogram is defined within the
5431 -- enclosing instance. If yes, it has precedence over outer candidates.
5433 ------------------------
5434 -- Enclosing_Instance --
5435 ------------------------
5437 function Enclosing_Instance return Entity_Id is
5441 if not Is_Generic_Instance (Current_Scope)
5442 and then not Is_Actual
5447 S := Scope (Current_Scope);
5448 while S /= Standard_Standard loop
5449 if Is_Generic_Instance (S) then
5457 end Enclosing_Instance;
5459 --------------------------
5460 -- Is_Visible_Operation --
5461 --------------------------
5463 function Is_Visible_Operation (Op : Entity_Id) return Boolean is
5469 if Ekind (Op) /= E_Operator
5470 or else Scope (Op) /= Standard_Standard
5471 or else (In_Instance
5474 or else Present (Enclosing_Instance)))
5479 -- For a fixed point type operator, check the resulting type,
5480 -- because it may be a mixed mode integer * fixed operation.
5482 if Present (Next_Formal (First_Formal (New_S)))
5483 and then Is_Fixed_Point_Type (Etype (New_S))
5485 Typ := Etype (New_S);
5487 Typ := Etype (First_Formal (New_S));
5490 Btyp := Base_Type (Typ);
5492 if Nkind (Nam) /= N_Expanded_Name then
5493 return (In_Open_Scopes (Scope (Btyp))
5494 or else Is_Potentially_Use_Visible (Btyp)
5495 or else In_Use (Btyp)
5496 or else In_Use (Scope (Btyp)));
5499 Scop := Entity (Prefix (Nam));
5501 if Ekind (Scop) = E_Package
5502 and then Present (Renamed_Object (Scop))
5504 Scop := Renamed_Object (Scop);
5507 -- Operator is visible if prefix of expanded name denotes
5508 -- scope of type, or else type is defined in System_Aux
5509 -- and the prefix denotes System.
5511 return Scope (Btyp) = Scop
5512 or else (Scope (Btyp) = System_Aux_Id
5513 and then Scope (Scope (Btyp)) = Scop);
5516 end Is_Visible_Operation;
5522 function Within (Inner, Outer : Entity_Id) return Boolean is
5526 Sc := Scope (Inner);
5527 while Sc /= Standard_Standard loop
5538 ---------------------
5539 -- Report_Overload --
5540 ---------------------
5542 function Report_Overload return Entity_Id is
5545 Error_Msg_NE -- CODEFIX
5546 ("ambiguous actual subprogram&, " &
5547 "possible interpretations:", N, Nam);
5549 Error_Msg_N -- CODEFIX
5550 ("ambiguous subprogram, " &
5551 "possible interpretations:", N);
5554 List_Interps (Nam, N);
5556 end Report_Overload;
5558 -- Start of processing for Find_Renamed_Entity
5562 Candidate_Renaming := Empty;
5564 if not Is_Overloaded (Nam) then
5565 if Entity_Matches_Spec (Entity (Nam), New_S) then
5566 Candidate_Renaming := New_S;
5568 if Is_Visible_Operation (Entity (Nam)) then
5569 Old_S := Entity (Nam);
5573 Present (First_Formal (Entity (Nam)))
5574 and then Present (First_Formal (New_S))
5575 and then (Base_Type (Etype (First_Formal (Entity (Nam))))
5576 = Base_Type (Etype (First_Formal (New_S))))
5578 Candidate_Renaming := Entity (Nam);
5582 Get_First_Interp (Nam, Ind, It);
5583 while Present (It.Nam) loop
5584 if Entity_Matches_Spec (It.Nam, New_S)
5585 and then Is_Visible_Operation (It.Nam)
5587 if Old_S /= Any_Id then
5589 -- Note: The call to Disambiguate only happens if a
5590 -- previous interpretation was found, in which case I1
5591 -- has received a value.
5593 It1 := Disambiguate (Nam, I1, Ind, Etype (Old_S));
5595 if It1 = No_Interp then
5596 Inst := Enclosing_Instance;
5598 if Present (Inst) then
5599 if Within (It.Nam, Inst) then
5600 if Within (Old_S, Inst) then
5602 -- Choose the innermost subprogram, which would
5603 -- have hidden the outer one in the generic.
5605 if Scope_Depth (It.Nam) <
5614 elsif Within (Old_S, Inst) then
5618 return Report_Overload;
5621 -- If not within an instance, ambiguity is real
5624 return Report_Overload;
5638 Present (First_Formal (It.Nam))
5639 and then Present (First_Formal (New_S))
5640 and then (Base_Type (Etype (First_Formal (It.Nam)))
5641 = Base_Type (Etype (First_Formal (New_S))))
5643 Candidate_Renaming := It.Nam;
5646 Get_Next_Interp (Ind, It);
5649 Set_Entity (Nam, Old_S);
5651 if Old_S /= Any_Id then
5652 Set_Is_Overloaded (Nam, False);
5657 end Find_Renamed_Entity;
5659 -----------------------------
5660 -- Find_Selected_Component --
5661 -----------------------------
5663 procedure Find_Selected_Component (N : Node_Id) is
5664 P : constant Node_Id := Prefix (N);
5667 -- Entity denoted by prefix
5677 if Nkind (P) = N_Error then
5681 -- Selector name cannot be a character literal or an operator symbol in
5682 -- SPARK, except for the operator symbol in a renaming.
5684 if Restriction_Check_Required (SPARK) then
5685 if Nkind (Selector_Name (N)) = N_Character_Literal then
5686 Check_SPARK_Restriction
5687 ("character literal cannot be prefixed", N);
5688 elsif Nkind (Selector_Name (N)) = N_Operator_Symbol
5689 and then Nkind (Parent (N)) /= N_Subprogram_Renaming_Declaration
5691 Check_SPARK_Restriction ("operator symbol cannot be prefixed", N);
5695 -- If the selector already has an entity, the node has been constructed
5696 -- in the course of expansion, and is known to be valid. Do not verify
5697 -- that it is defined for the type (it may be a private component used
5698 -- in the expansion of record equality).
5700 if Present (Entity (Selector_Name (N))) then
5702 or else Etype (N) = Any_Type
5705 Sel_Name : constant Node_Id := Selector_Name (N);
5706 Selector : constant Entity_Id := Entity (Sel_Name);
5710 Set_Etype (Sel_Name, Etype (Selector));
5712 if not Is_Entity_Name (P) then
5716 -- Build an actual subtype except for the first parameter
5717 -- of an init proc, where this actual subtype is by
5718 -- definition incorrect, since the object is uninitialized
5719 -- (and does not even have defined discriminants etc.)
5721 if Is_Entity_Name (P)
5722 and then Ekind (Entity (P)) = E_Function
5724 Nam := New_Copy (P);
5726 if Is_Overloaded (P) then
5727 Save_Interps (P, Nam);
5731 Make_Function_Call (Sloc (P), Name => Nam));
5733 Analyze_Selected_Component (N);
5736 elsif Ekind (Selector) = E_Component
5737 and then (not Is_Entity_Name (P)
5738 or else Chars (Entity (P)) /= Name_uInit)
5740 -- Do not build the subtype when referencing components of
5741 -- dispatch table wrappers. Required to avoid generating
5742 -- elaboration code with HI runtimes. JVM and .NET use a
5743 -- modified version of Ada.Tags which does not contain RE_
5744 -- Dispatch_Table_Wrapper and RE_No_Dispatch_Table_Wrapper.
5745 -- Avoid raising RE_Not_Available exception in those cases.
5747 if VM_Target = No_VM
5748 and then RTU_Loaded (Ada_Tags)
5750 ((RTE_Available (RE_Dispatch_Table_Wrapper)
5751 and then Scope (Selector) =
5752 RTE (RE_Dispatch_Table_Wrapper))
5754 (RTE_Available (RE_No_Dispatch_Table_Wrapper)
5755 and then Scope (Selector) =
5756 RTE (RE_No_Dispatch_Table_Wrapper)))
5762 Build_Actual_Subtype_Of_Component
5763 (Etype (Selector), N);
5770 if No (C_Etype) then
5771 C_Etype := Etype (Selector);
5773 Insert_Action (N, C_Etype);
5774 C_Etype := Defining_Identifier (C_Etype);
5777 Set_Etype (N, C_Etype);
5780 -- If this is the name of an entry or protected operation, and
5781 -- the prefix is an access type, insert an explicit dereference,
5782 -- so that entry calls are treated uniformly.
5784 if Is_Access_Type (Etype (P))
5785 and then Is_Concurrent_Type (Designated_Type (Etype (P)))
5788 New_P : constant Node_Id :=
5789 Make_Explicit_Dereference (Sloc (P),
5790 Prefix => Relocate_Node (P));
5793 Set_Etype (P, Designated_Type (Etype (Prefix (P))));
5797 -- If the selected component appears within a default expression
5798 -- and it has an actual subtype, the pre-analysis has not yet
5799 -- completed its analysis, because Insert_Actions is disabled in
5800 -- that context. Within the init proc of the enclosing type we
5801 -- must complete this analysis, if an actual subtype was created.
5803 elsif Inside_Init_Proc then
5805 Typ : constant Entity_Id := Etype (N);
5806 Decl : constant Node_Id := Declaration_Node (Typ);
5808 if Nkind (Decl) = N_Subtype_Declaration
5809 and then not Analyzed (Decl)
5810 and then Is_List_Member (Decl)
5811 and then No (Parent (Decl))
5814 Insert_Action (N, Decl);
5821 elsif Is_Entity_Name (P) then
5822 P_Name := Entity (P);
5824 -- The prefix may denote an enclosing type which is the completion
5825 -- of an incomplete type declaration.
5827 if Is_Type (P_Name) then
5828 Set_Entity (P, Get_Full_View (P_Name));
5829 Set_Etype (P, Entity (P));
5830 P_Name := Entity (P);
5833 P_Type := Base_Type (Etype (P));
5835 if Debug_Flag_E then
5836 Write_Str ("Found prefix type to be ");
5837 Write_Entity_Info (P_Type, " "); Write_Eol;
5840 -- First check for components of a record object (not the
5841 -- result of a call, which is handled below).
5843 if Is_Appropriate_For_Record (P_Type)
5844 and then not Is_Overloadable (P_Name)
5845 and then not Is_Type (P_Name)
5847 -- Selected component of record. Type checking will validate
5848 -- name of selector.
5849 -- ??? could we rewrite an implicit dereference into an explicit
5852 Analyze_Selected_Component (N);
5854 -- Reference to type name in predicate/invariant expression
5856 elsif Is_Appropriate_For_Entry_Prefix (P_Type)
5857 and then not In_Open_Scopes (P_Name)
5858 and then (not Is_Concurrent_Type (Etype (P_Name))
5859 or else not In_Open_Scopes (Etype (P_Name)))
5861 -- Call to protected operation or entry. Type checking is
5862 -- needed on the prefix.
5864 Analyze_Selected_Component (N);
5866 elsif (In_Open_Scopes (P_Name)
5867 and then Ekind (P_Name) /= E_Void
5868 and then not Is_Overloadable (P_Name))
5869 or else (Is_Concurrent_Type (Etype (P_Name))
5870 and then In_Open_Scopes (Etype (P_Name)))
5872 -- Prefix denotes an enclosing loop, block, or task, i.e. an
5873 -- enclosing construct that is not a subprogram or accept.
5875 Find_Expanded_Name (N);
5877 elsif Ekind (P_Name) = E_Package then
5878 Find_Expanded_Name (N);
5880 elsif Is_Overloadable (P_Name) then
5882 -- The subprogram may be a renaming (of an enclosing scope) as
5883 -- in the case of the name of the generic within an instantiation.
5885 if Ekind_In (P_Name, E_Procedure, E_Function)
5886 and then Present (Alias (P_Name))
5887 and then Is_Generic_Instance (Alias (P_Name))
5889 P_Name := Alias (P_Name);
5892 if Is_Overloaded (P) then
5894 -- The prefix must resolve to a unique enclosing construct
5897 Found : Boolean := False;
5902 Get_First_Interp (P, Ind, It);
5903 while Present (It.Nam) loop
5904 if In_Open_Scopes (It.Nam) then
5907 "prefix must be unique enclosing scope", N);
5908 Set_Entity (N, Any_Id);
5909 Set_Etype (N, Any_Type);
5918 Get_Next_Interp (Ind, It);
5923 if In_Open_Scopes (P_Name) then
5924 Set_Entity (P, P_Name);
5925 Set_Is_Overloaded (P, False);
5926 Find_Expanded_Name (N);
5929 -- If no interpretation as an expanded name is possible, it
5930 -- must be a selected component of a record returned by a
5931 -- function call. Reformat prefix as a function call, the rest
5932 -- is done by type resolution. If the prefix is procedure or
5933 -- entry, as is P.X; this is an error.
5935 if Ekind (P_Name) /= E_Function
5936 and then (not Is_Overloaded (P)
5938 Nkind (Parent (N)) = N_Procedure_Call_Statement)
5940 -- Prefix may mention a package that is hidden by a local
5941 -- declaration: let the user know. Scan the full homonym
5942 -- chain, the candidate package may be anywhere on it.
5944 if Present (Homonym (Current_Entity (P_Name))) then
5946 P_Name := Current_Entity (P_Name);
5948 while Present (P_Name) loop
5949 exit when Ekind (P_Name) = E_Package;
5950 P_Name := Homonym (P_Name);
5953 if Present (P_Name) then
5954 Error_Msg_Sloc := Sloc (Entity (Prefix (N)));
5957 ("package& is hidden by declaration#",
5960 Set_Entity (Prefix (N), P_Name);
5961 Find_Expanded_Name (N);
5964 P_Name := Entity (Prefix (N));
5969 ("invalid prefix in selected component&", N, P_Name);
5970 Change_Selected_Component_To_Expanded_Name (N);
5971 Set_Entity (N, Any_Id);
5972 Set_Etype (N, Any_Type);
5975 Nam := New_Copy (P);
5976 Save_Interps (P, Nam);
5978 Make_Function_Call (Sloc (P), Name => Nam));
5980 Analyze_Selected_Component (N);
5984 -- Remaining cases generate various error messages
5987 -- Format node as expanded name, to avoid cascaded errors
5989 Change_Selected_Component_To_Expanded_Name (N);
5990 Set_Entity (N, Any_Id);
5991 Set_Etype (N, Any_Type);
5993 -- Issue error message, but avoid this if error issued already.
5994 -- Use identifier of prefix if one is available.
5996 if P_Name = Any_Id then
5999 elsif Ekind (P_Name) = E_Void then
6000 Premature_Usage (P);
6002 elsif Nkind (P) /= N_Attribute_Reference then
6004 "invalid prefix in selected component&", P);
6006 if Is_Access_Type (P_Type)
6007 and then Ekind (Designated_Type (P_Type)) = E_Incomplete_Type
6010 ("\dereference must not be of an incomplete type " &
6016 "invalid prefix in selected component", P);
6020 -- Selector name is restricted in SPARK
6022 if Nkind (N) = N_Expanded_Name
6023 and then Restriction_Check_Required (SPARK)
6025 if Is_Subprogram (P_Name) then
6026 Check_SPARK_Restriction
6027 ("prefix of expanded name cannot be a subprogram", P);
6028 elsif Ekind (P_Name) = E_Loop then
6029 Check_SPARK_Restriction
6030 ("prefix of expanded name cannot be a loop statement", P);
6035 -- If prefix is not the name of an entity, it must be an expression,
6036 -- whose type is appropriate for a record. This is determined by
6039 Analyze_Selected_Component (N);
6041 end Find_Selected_Component;
6047 procedure Find_Type (N : Node_Id) is
6057 elsif Nkind (N) = N_Attribute_Reference then
6059 -- Class attribute. This is not valid in Ada 83 mode, but we do not
6060 -- need to enforce that at this point, since the declaration of the
6061 -- tagged type in the prefix would have been flagged already.
6063 if Attribute_Name (N) = Name_Class then
6064 Check_Restriction (No_Dispatch, N);
6065 Find_Type (Prefix (N));
6067 -- Propagate error from bad prefix
6069 if Etype (Prefix (N)) = Any_Type then
6070 Set_Entity (N, Any_Type);
6071 Set_Etype (N, Any_Type);
6075 T := Base_Type (Entity (Prefix (N)));
6077 -- Case where type is not known to be tagged. Its appearance in
6078 -- the prefix of the 'Class attribute indicates that the full view
6081 if not Is_Tagged_Type (T) then
6082 if Ekind (T) = E_Incomplete_Type then
6084 -- It is legal to denote the class type of an incomplete
6085 -- type. The full type will have to be tagged, of course.
6086 -- In Ada 2005 this usage is declared obsolescent, so we
6087 -- warn accordingly. This usage is only legal if the type
6088 -- is completed in the current scope, and not for a limited
6091 if not Is_Tagged_Type (T)
6092 and then Ada_Version >= Ada_2005
6094 if From_With_Type (T) then
6096 ("prefix of Class attribute must be tagged", N);
6097 Set_Etype (N, Any_Type);
6098 Set_Entity (N, Any_Type);
6101 -- ??? This test is temporarily disabled (always False)
6102 -- because it causes an unwanted warning on GNAT sources
6103 -- (built with -gnatg, which includes Warn_On_Obsolescent_
6104 -- Feature). Once this issue is cleared in the sources, it
6107 elsif Warn_On_Obsolescent_Feature
6111 ("applying 'Class to an untagged incomplete type"
6112 & " is an obsolescent feature (RM J.11)", N);
6116 Set_Is_Tagged_Type (T);
6117 Set_Direct_Primitive_Operations (T, New_Elmt_List);
6118 Make_Class_Wide_Type (T);
6119 Set_Entity (N, Class_Wide_Type (T));
6120 Set_Etype (N, Class_Wide_Type (T));
6122 elsif Ekind (T) = E_Private_Type
6123 and then not Is_Generic_Type (T)
6124 and then In_Private_Part (Scope (T))
6126 -- The Class attribute can be applied to an untagged private
6127 -- type fulfilled by a tagged type prior to the full type
6128 -- declaration (but only within the parent package's private
6129 -- part). Create the class-wide type now and check that the
6130 -- full type is tagged later during its analysis. Note that
6131 -- we do not mark the private type as tagged, unlike the
6132 -- case of incomplete types, because the type must still
6133 -- appear untagged to outside units.
6135 if No (Class_Wide_Type (T)) then
6136 Make_Class_Wide_Type (T);
6139 Set_Entity (N, Class_Wide_Type (T));
6140 Set_Etype (N, Class_Wide_Type (T));
6143 -- Should we introduce a type Any_Tagged and use Wrong_Type
6144 -- here, it would be a bit more consistent???
6147 ("tagged type required, found}",
6148 Prefix (N), First_Subtype (T));
6149 Set_Entity (N, Any_Type);
6153 -- Case of tagged type
6156 if Is_Concurrent_Type (T) then
6157 if No (Corresponding_Record_Type (Entity (Prefix (N)))) then
6159 -- Previous error. Use current type, which at least
6160 -- provides some operations.
6162 C := Entity (Prefix (N));
6165 C := Class_Wide_Type
6166 (Corresponding_Record_Type (Entity (Prefix (N))));
6170 C := Class_Wide_Type (Entity (Prefix (N)));
6173 Set_Entity_With_Style_Check (N, C);
6174 Generate_Reference (C, N);
6178 -- Base attribute, not allowed in Ada 83
6180 elsif Attribute_Name (N) = Name_Base then
6181 Error_Msg_Name_1 := Name_Base;
6182 Check_SPARK_Restriction
6183 ("attribute% is only allowed as prefix of another attribute", N);
6185 if Ada_Version = Ada_83 and then Comes_From_Source (N) then
6187 ("(Ada 83) Base attribute not allowed in subtype mark", N);
6190 Find_Type (Prefix (N));
6191 Typ := Entity (Prefix (N));
6193 if Ada_Version >= Ada_95
6194 and then not Is_Scalar_Type (Typ)
6195 and then not Is_Generic_Type (Typ)
6198 ("prefix of Base attribute must be scalar type",
6201 elsif Warn_On_Redundant_Constructs
6202 and then Base_Type (Typ) = Typ
6204 Error_Msg_NE -- CODEFIX
6205 ("?redundant attribute, & is its own base type", N, Typ);
6208 T := Base_Type (Typ);
6210 -- Rewrite attribute reference with type itself (see similar
6211 -- processing in Analyze_Attribute, case Base). Preserve prefix
6212 -- if present, for other legality checks.
6214 if Nkind (Prefix (N)) = N_Expanded_Name then
6216 Make_Expanded_Name (Sloc (N),
6218 Prefix => New_Copy (Prefix (Prefix (N))),
6219 Selector_Name => New_Reference_To (T, Sloc (N))));
6222 Rewrite (N, New_Reference_To (T, Sloc (N)));
6229 elsif Attribute_Name (N) = Name_Stub_Type then
6231 -- This is handled in Analyze_Attribute
6235 -- All other attributes are invalid in a subtype mark
6238 Error_Msg_N ("invalid attribute in subtype mark", N);
6244 if Is_Entity_Name (N) then
6245 T_Name := Entity (N);
6247 Error_Msg_N ("subtype mark required in this context", N);
6248 Set_Etype (N, Any_Type);
6252 if T_Name = Any_Id or else Etype (N) = Any_Type then
6254 -- Undefined id. Make it into a valid type
6256 Set_Entity (N, Any_Type);
6258 elsif not Is_Type (T_Name)
6259 and then T_Name /= Standard_Void_Type
6261 Error_Msg_Sloc := Sloc (T_Name);
6262 Error_Msg_N ("subtype mark required in this context", N);
6263 Error_Msg_NE ("\\found & declared#", N, T_Name);
6264 Set_Entity (N, Any_Type);
6267 -- If the type is an incomplete type created to handle
6268 -- anonymous access components of a record type, then the
6269 -- incomplete type is the visible entity and subsequent
6270 -- references will point to it. Mark the original full
6271 -- type as referenced, to prevent spurious warnings.
6273 if Is_Incomplete_Type (T_Name)
6274 and then Present (Full_View (T_Name))
6275 and then not Comes_From_Source (T_Name)
6277 Set_Referenced (Full_View (T_Name));
6280 T_Name := Get_Full_View (T_Name);
6282 -- Ada 2005 (AI-251, AI-50217): Handle interfaces visible through
6283 -- limited-with clauses
6285 if From_With_Type (T_Name)
6286 and then Ekind (T_Name) in Incomplete_Kind
6287 and then Present (Non_Limited_View (T_Name))
6288 and then Is_Interface (Non_Limited_View (T_Name))
6290 T_Name := Non_Limited_View (T_Name);
6293 if In_Open_Scopes (T_Name) then
6294 if Ekind (Base_Type (T_Name)) = E_Task_Type then
6296 -- In Ada 2005, a task name can be used in an access
6297 -- definition within its own body. It cannot be used
6298 -- in the discriminant part of the task declaration,
6299 -- nor anywhere else in the declaration because entries
6300 -- cannot have access parameters.
6302 if Ada_Version >= Ada_2005
6303 and then Nkind (Parent (N)) = N_Access_Definition
6305 Set_Entity (N, T_Name);
6306 Set_Etype (N, T_Name);
6308 if Has_Completion (T_Name) then
6313 ("task type cannot be used as type mark " &
6314 "within its own declaration", N);
6319 ("task type cannot be used as type mark " &
6320 "within its own spec or body", N);
6323 elsif Ekind (Base_Type (T_Name)) = E_Protected_Type then
6325 -- In Ada 2005, a protected name can be used in an access
6326 -- definition within its own body.
6328 if Ada_Version >= Ada_2005
6329 and then Nkind (Parent (N)) = N_Access_Definition
6331 Set_Entity (N, T_Name);
6332 Set_Etype (N, T_Name);
6337 ("protected type cannot be used as type mark " &
6338 "within its own spec or body", N);
6342 Error_Msg_N ("type declaration cannot refer to itself", N);
6345 Set_Etype (N, Any_Type);
6346 Set_Entity (N, Any_Type);
6347 Set_Error_Posted (T_Name);
6351 Set_Entity (N, T_Name);
6352 Set_Etype (N, T_Name);
6356 if Present (Etype (N)) and then Comes_From_Source (N) then
6357 if Is_Fixed_Point_Type (Etype (N)) then
6358 Check_Restriction (No_Fixed_Point, N);
6359 elsif Is_Floating_Point_Type (Etype (N)) then
6360 Check_Restriction (No_Floating_Point, N);
6365 ------------------------------------
6366 -- Has_Implicit_Character_Literal --
6367 ------------------------------------
6369 function Has_Implicit_Character_Literal (N : Node_Id) return Boolean is
6371 Found : Boolean := False;
6372 P : constant Entity_Id := Entity (Prefix (N));
6373 Priv_Id : Entity_Id := Empty;
6376 if Ekind (P) = E_Package
6377 and then not In_Open_Scopes (P)
6379 Priv_Id := First_Private_Entity (P);
6382 if P = Standard_Standard then
6383 Change_Selected_Component_To_Expanded_Name (N);
6384 Rewrite (N, Selector_Name (N));
6386 Set_Etype (Original_Node (N), Standard_Character);
6390 Id := First_Entity (P);
6392 and then Id /= Priv_Id
6394 if Is_Standard_Character_Type (Id) and then Is_Base_Type (Id) then
6396 -- We replace the node with the literal itself, resolve as a
6397 -- character, and set the type correctly.
6400 Change_Selected_Component_To_Expanded_Name (N);
6401 Rewrite (N, Selector_Name (N));
6404 Set_Etype (Original_Node (N), Id);
6408 -- More than one type derived from Character in given scope.
6409 -- Collect all possible interpretations.
6411 Add_One_Interp (N, Id, Id);
6419 end Has_Implicit_Character_Literal;
6421 ----------------------
6422 -- Has_Private_With --
6423 ----------------------
6425 function Has_Private_With (E : Entity_Id) return Boolean is
6426 Comp_Unit : constant Node_Id := Cunit (Current_Sem_Unit);
6430 Item := First (Context_Items (Comp_Unit));
6431 while Present (Item) loop
6432 if Nkind (Item) = N_With_Clause
6433 and then Private_Present (Item)
6434 and then Entity (Name (Item)) = E
6443 end Has_Private_With;
6445 ---------------------------
6446 -- Has_Implicit_Operator --
6447 ---------------------------
6449 function Has_Implicit_Operator (N : Node_Id) return Boolean is
6450 Op_Id : constant Name_Id := Chars (Selector_Name (N));
6451 P : constant Entity_Id := Entity (Prefix (N));
6453 Priv_Id : Entity_Id := Empty;
6455 procedure Add_Implicit_Operator
6457 Op_Type : Entity_Id := Empty);
6458 -- Add implicit interpretation to node N, using the type for which a
6459 -- predefined operator exists. If the operator yields a boolean type,
6460 -- the Operand_Type is implicitly referenced by the operator, and a
6461 -- reference to it must be generated.
6463 ---------------------------
6464 -- Add_Implicit_Operator --
6465 ---------------------------
6467 procedure Add_Implicit_Operator
6469 Op_Type : Entity_Id := Empty)
6471 Predef_Op : Entity_Id;
6474 Predef_Op := Current_Entity (Selector_Name (N));
6476 while Present (Predef_Op)
6477 and then Scope (Predef_Op) /= Standard_Standard
6479 Predef_Op := Homonym (Predef_Op);
6482 if Nkind (N) = N_Selected_Component then
6483 Change_Selected_Component_To_Expanded_Name (N);
6486 -- If the context is an unanalyzed function call, determine whether
6487 -- a binary or unary interpretation is required.
6489 if Nkind (Parent (N)) = N_Indexed_Component then
6491 Is_Binary_Call : constant Boolean :=
6493 (Next (First (Expressions (Parent (N)))));
6494 Is_Binary_Op : constant Boolean :=
6496 (Predef_Op) /= Last_Entity (Predef_Op);
6497 Predef_Op2 : constant Entity_Id := Homonym (Predef_Op);
6500 if Is_Binary_Call then
6501 if Is_Binary_Op then
6502 Add_One_Interp (N, Predef_Op, T);
6504 Add_One_Interp (N, Predef_Op2, T);
6508 if not Is_Binary_Op then
6509 Add_One_Interp (N, Predef_Op, T);
6511 Add_One_Interp (N, Predef_Op2, T);
6517 Add_One_Interp (N, Predef_Op, T);
6519 -- For operators with unary and binary interpretations, if
6520 -- context is not a call, add both
6522 if Present (Homonym (Predef_Op)) then
6523 Add_One_Interp (N, Homonym (Predef_Op), T);
6527 -- The node is a reference to a predefined operator, and
6528 -- an implicit reference to the type of its operands.
6530 if Present (Op_Type) then
6531 Generate_Operator_Reference (N, Op_Type);
6533 Generate_Operator_Reference (N, T);
6535 end Add_Implicit_Operator;
6537 -- Start of processing for Has_Implicit_Operator
6540 if Ekind (P) = E_Package
6541 and then not In_Open_Scopes (P)
6543 Priv_Id := First_Private_Entity (P);
6546 Id := First_Entity (P);
6550 -- Boolean operators: an implicit declaration exists if the scope
6551 -- contains a declaration for a derived Boolean type, or for an
6552 -- array of Boolean type.
6554 when Name_Op_And | Name_Op_Not | Name_Op_Or | Name_Op_Xor =>
6555 while Id /= Priv_Id loop
6556 if Valid_Boolean_Arg (Id) and then Is_Base_Type (Id) then
6557 Add_Implicit_Operator (Id);
6564 -- Equality: look for any non-limited type (result is Boolean)
6566 when Name_Op_Eq | Name_Op_Ne =>
6567 while Id /= Priv_Id loop
6569 and then not Is_Limited_Type (Id)
6570 and then Is_Base_Type (Id)
6572 Add_Implicit_Operator (Standard_Boolean, Id);
6579 -- Comparison operators: scalar type, or array of scalar
6581 when Name_Op_Lt | Name_Op_Le | Name_Op_Gt | Name_Op_Ge =>
6582 while Id /= Priv_Id loop
6583 if (Is_Scalar_Type (Id)
6584 or else (Is_Array_Type (Id)
6585 and then Is_Scalar_Type (Component_Type (Id))))
6586 and then Is_Base_Type (Id)
6588 Add_Implicit_Operator (Standard_Boolean, Id);
6595 -- Arithmetic operators: any numeric type
6605 while Id /= Priv_Id loop
6606 if Is_Numeric_Type (Id) and then Is_Base_Type (Id) then
6607 Add_Implicit_Operator (Id);
6614 -- Concatenation: any one-dimensional array type
6616 when Name_Op_Concat =>
6617 while Id /= Priv_Id loop
6618 if Is_Array_Type (Id)
6619 and then Number_Dimensions (Id) = 1
6620 and then Is_Base_Type (Id)
6622 Add_Implicit_Operator (Id);
6629 -- What is the others condition here? Should we be using a
6630 -- subtype of Name_Id that would restrict to operators ???
6632 when others => null;
6635 -- If we fall through, then we do not have an implicit operator
6639 end Has_Implicit_Operator;
6641 -----------------------------------
6642 -- Has_Loop_In_Inner_Open_Scopes --
6643 -----------------------------------
6645 function Has_Loop_In_Inner_Open_Scopes (S : Entity_Id) return Boolean is
6647 -- Several scope stacks are maintained by Scope_Stack. The base of the
6648 -- currently active scope stack is denoted by the Is_Active_Stack_Base
6649 -- flag in the scope stack entry. Note that the scope stacks used to
6650 -- simply be delimited implicitly by the presence of Standard_Standard
6651 -- at their base, but there now are cases where this is not sufficient
6652 -- because Standard_Standard actually may appear in the middle of the
6653 -- active set of scopes.
6655 for J in reverse 0 .. Scope_Stack.Last loop
6657 -- S was reached without seing a loop scope first
6659 if Scope_Stack.Table (J).Entity = S then
6662 -- S was not yet reached, so it contains at least one inner loop
6664 elsif Ekind (Scope_Stack.Table (J).Entity) = E_Loop then
6668 -- Check Is_Active_Stack_Base to tell us when to stop, as there are
6669 -- cases where Standard_Standard appears in the middle of the active
6670 -- set of scopes. This affects the declaration and overriding of
6671 -- private inherited operations in instantiations of generic child
6674 pragma Assert (not Scope_Stack.Table (J).Is_Active_Stack_Base);
6677 raise Program_Error; -- unreachable
6678 end Has_Loop_In_Inner_Open_Scopes;
6680 --------------------
6681 -- In_Open_Scopes --
6682 --------------------
6684 function In_Open_Scopes (S : Entity_Id) return Boolean is
6686 -- Several scope stacks are maintained by Scope_Stack. The base of the
6687 -- currently active scope stack is denoted by the Is_Active_Stack_Base
6688 -- flag in the scope stack entry. Note that the scope stacks used to
6689 -- simply be delimited implicitly by the presence of Standard_Standard
6690 -- at their base, but there now are cases where this is not sufficient
6691 -- because Standard_Standard actually may appear in the middle of the
6692 -- active set of scopes.
6694 for J in reverse 0 .. Scope_Stack.Last loop
6695 if Scope_Stack.Table (J).Entity = S then
6699 -- Check Is_Active_Stack_Base to tell us when to stop, as there are
6700 -- cases where Standard_Standard appears in the middle of the active
6701 -- set of scopes. This affects the declaration and overriding of
6702 -- private inherited operations in instantiations of generic child
6705 exit when Scope_Stack.Table (J).Is_Active_Stack_Base;
6711 -----------------------------
6712 -- Inherit_Renamed_Profile --
6713 -----------------------------
6715 procedure Inherit_Renamed_Profile (New_S : Entity_Id; Old_S : Entity_Id) is
6722 if Ekind (Old_S) = E_Operator then
6723 New_F := First_Formal (New_S);
6725 while Present (New_F) loop
6726 Set_Etype (New_F, Base_Type (Etype (New_F)));
6727 Next_Formal (New_F);
6730 Set_Etype (New_S, Base_Type (Etype (New_S)));
6733 New_F := First_Formal (New_S);
6734 Old_F := First_Formal (Old_S);
6736 while Present (New_F) loop
6737 New_T := Etype (New_F);
6738 Old_T := Etype (Old_F);
6740 -- If the new type is a renaming of the old one, as is the
6741 -- case for actuals in instances, retain its name, to simplify
6742 -- later disambiguation.
6744 if Nkind (Parent (New_T)) = N_Subtype_Declaration
6745 and then Is_Entity_Name (Subtype_Indication (Parent (New_T)))
6746 and then Entity (Subtype_Indication (Parent (New_T))) = Old_T
6750 Set_Etype (New_F, Old_T);
6753 Next_Formal (New_F);
6754 Next_Formal (Old_F);
6757 if Ekind_In (Old_S, E_Function, E_Enumeration_Literal) then
6758 Set_Etype (New_S, Etype (Old_S));
6761 end Inherit_Renamed_Profile;
6767 procedure Initialize is
6772 -------------------------
6773 -- Install_Use_Clauses --
6774 -------------------------
6776 procedure Install_Use_Clauses
6778 Force_Installation : Boolean := False)
6786 while Present (U) loop
6788 -- Case of USE package
6790 if Nkind (U) = N_Use_Package_Clause then
6791 P := First (Names (U));
6792 while Present (P) loop
6795 if Ekind (Id) = E_Package then
6797 Note_Redundant_Use (P);
6799 elsif Present (Renamed_Object (Id))
6800 and then In_Use (Renamed_Object (Id))
6802 Note_Redundant_Use (P);
6804 elsif Force_Installation or else Applicable_Use (P) then
6805 Use_One_Package (Id, U);
6816 P := First (Subtype_Marks (U));
6817 while Present (P) loop
6818 if not Is_Entity_Name (P)
6819 or else No (Entity (P))
6823 elsif Entity (P) /= Any_Type then
6831 Next_Use_Clause (U);
6833 end Install_Use_Clauses;
6835 -------------------------------------
6836 -- Is_Appropriate_For_Entry_Prefix --
6837 -------------------------------------
6839 function Is_Appropriate_For_Entry_Prefix (T : Entity_Id) return Boolean is
6840 P_Type : Entity_Id := T;
6843 if Is_Access_Type (P_Type) then
6844 P_Type := Designated_Type (P_Type);
6847 return Is_Task_Type (P_Type) or else Is_Protected_Type (P_Type);
6848 end Is_Appropriate_For_Entry_Prefix;
6850 -------------------------------
6851 -- Is_Appropriate_For_Record --
6852 -------------------------------
6854 function Is_Appropriate_For_Record (T : Entity_Id) return Boolean is
6856 function Has_Components (T1 : Entity_Id) return Boolean;
6857 -- Determine if given type has components (i.e. is either a record
6858 -- type or a type that has discriminants).
6860 --------------------
6861 -- Has_Components --
6862 --------------------
6864 function Has_Components (T1 : Entity_Id) return Boolean is
6866 return Is_Record_Type (T1)
6867 or else (Is_Private_Type (T1) and then Has_Discriminants (T1))
6868 or else (Is_Task_Type (T1) and then Has_Discriminants (T1))
6869 or else (Is_Incomplete_Type (T1)
6870 and then From_With_Type (T1)
6871 and then Present (Non_Limited_View (T1))
6872 and then Is_Record_Type
6873 (Get_Full_View (Non_Limited_View (T1))));
6876 -- Start of processing for Is_Appropriate_For_Record
6881 and then (Has_Components (T)
6882 or else (Is_Access_Type (T)
6883 and then Has_Components (Designated_Type (T))));
6884 end Is_Appropriate_For_Record;
6886 ------------------------
6887 -- Note_Redundant_Use --
6888 ------------------------
6890 procedure Note_Redundant_Use (Clause : Node_Id) is
6891 Pack_Name : constant Entity_Id := Entity (Clause);
6892 Cur_Use : constant Node_Id := Current_Use_Clause (Pack_Name);
6893 Decl : constant Node_Id := Parent (Clause);
6895 Prev_Use : Node_Id := Empty;
6896 Redundant : Node_Id := Empty;
6897 -- The Use_Clause which is actually redundant. In the simplest case it
6898 -- is Pack itself, but when we compile a body we install its context
6899 -- before that of its spec, in which case it is the use_clause in the
6900 -- spec that will appear to be redundant, and we want the warning to be
6901 -- placed on the body. Similar complications appear when the redundancy
6902 -- is between a child unit and one of its ancestors.
6905 Set_Redundant_Use (Clause, True);
6907 if not Comes_From_Source (Clause)
6909 or else not Warn_On_Redundant_Constructs
6914 if not Is_Compilation_Unit (Current_Scope) then
6916 -- If the use_clause is in an inner scope, it is made redundant by
6917 -- some clause in the current context, with one exception: If we're
6918 -- compiling a nested package body, and the use_clause comes from the
6919 -- corresponding spec, the clause is not necessarily fully redundant,
6920 -- so we should not warn. If a warning was warranted, it would have
6921 -- been given when the spec was processed.
6923 if Nkind (Parent (Decl)) = N_Package_Specification then
6925 Package_Spec_Entity : constant Entity_Id :=
6926 Defining_Unit_Name (Parent (Decl));
6928 if In_Package_Body (Package_Spec_Entity) then
6934 Redundant := Clause;
6935 Prev_Use := Cur_Use;
6937 elsif Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Body then
6939 Cur_Unit : constant Unit_Number_Type := Get_Source_Unit (Cur_Use);
6940 New_Unit : constant Unit_Number_Type := Get_Source_Unit (Clause);
6944 if Cur_Unit = New_Unit then
6946 -- Redundant clause in same body
6948 Redundant := Clause;
6949 Prev_Use := Cur_Use;
6951 elsif Cur_Unit = Current_Sem_Unit then
6953 -- If the new clause is not in the current unit it has been
6954 -- analyzed first, and it makes the other one redundant.
6955 -- However, if the new clause appears in a subunit, Cur_Unit
6956 -- is still the parent, and in that case the redundant one
6957 -- is the one appearing in the subunit.
6959 if Nkind (Unit (Cunit (New_Unit))) = N_Subunit then
6960 Redundant := Clause;
6961 Prev_Use := Cur_Use;
6963 -- Most common case: redundant clause in body,
6964 -- original clause in spec. Current scope is spec entity.
6969 Unit (Library_Unit (Cunit (Current_Sem_Unit))))
6971 Redundant := Cur_Use;
6975 -- The new clause may appear in an unrelated unit, when
6976 -- the parents of a generic are being installed prior to
6977 -- instantiation. In this case there must be no warning.
6978 -- We detect this case by checking whether the current top
6979 -- of the stack is related to the current compilation.
6981 Scop := Current_Scope;
6982 while Present (Scop)
6983 and then Scop /= Standard_Standard
6985 if Is_Compilation_Unit (Scop)
6986 and then not Is_Child_Unit (Scop)
6990 elsif Scop = Cunit_Entity (Current_Sem_Unit) then
6994 Scop := Scope (Scop);
6997 Redundant := Cur_Use;
7001 elsif New_Unit = Current_Sem_Unit then
7002 Redundant := Clause;
7003 Prev_Use := Cur_Use;
7006 -- Neither is the current unit, so they appear in parent or
7007 -- sibling units. Warning will be emitted elsewhere.
7013 elsif Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Declaration
7014 and then Present (Parent_Spec (Unit (Cunit (Current_Sem_Unit))))
7016 -- Use_clause is in child unit of current unit, and the child unit
7017 -- appears in the context of the body of the parent, so it has been
7018 -- installed first, even though it is the redundant one. Depending on
7019 -- their placement in the context, the visible or the private parts
7020 -- of the two units, either might appear as redundant, but the
7021 -- message has to be on the current unit.
7023 if Get_Source_Unit (Cur_Use) = Current_Sem_Unit then
7024 Redundant := Cur_Use;
7027 Redundant := Clause;
7028 Prev_Use := Cur_Use;
7031 -- If the new use clause appears in the private part of a parent unit
7032 -- it may appear to be redundant w.r.t. a use clause in a child unit,
7033 -- but the previous use clause was needed in the visible part of the
7034 -- child, and no warning should be emitted.
7036 if Nkind (Parent (Decl)) = N_Package_Specification
7038 List_Containing (Decl) = Private_Declarations (Parent (Decl))
7041 Par : constant Entity_Id := Defining_Entity (Parent (Decl));
7042 Spec : constant Node_Id :=
7043 Specification (Unit (Cunit (Current_Sem_Unit)));
7046 if Is_Compilation_Unit (Par)
7047 and then Par /= Cunit_Entity (Current_Sem_Unit)
7048 and then Parent (Cur_Use) = Spec
7050 List_Containing (Cur_Use) = Visible_Declarations (Spec)
7057 -- Finally, if the current use clause is in the context then
7058 -- the clause is redundant when it is nested within the unit.
7060 elsif Nkind (Parent (Cur_Use)) = N_Compilation_Unit
7061 and then Nkind (Parent (Parent (Clause))) /= N_Compilation_Unit
7062 and then Get_Source_Unit (Cur_Use) = Get_Source_Unit (Clause)
7064 Redundant := Clause;
7065 Prev_Use := Cur_Use;
7071 if Present (Redundant) then
7072 Error_Msg_Sloc := Sloc (Prev_Use);
7073 Error_Msg_NE -- CODEFIX
7074 ("& is already use-visible through previous use clause #?",
7075 Redundant, Pack_Name);
7077 end Note_Redundant_Use;
7083 procedure Pop_Scope is
7084 SST : Scope_Stack_Entry renames Scope_Stack.Table (Scope_Stack.Last);
7085 S : constant Entity_Id := SST.Entity;
7088 if Debug_Flag_E then
7092 -- Set Default_Storage_Pool field of the library unit if necessary
7094 if Ekind_In (S, E_Package, E_Generic_Package)
7096 Nkind (Parent (Unit_Declaration_Node (S))) = N_Compilation_Unit
7099 Aux : constant Node_Id :=
7100 Aux_Decls_Node (Parent (Unit_Declaration_Node (S)));
7102 if No (Default_Storage_Pool (Aux)) then
7103 Set_Default_Storage_Pool (Aux, Default_Pool);
7108 Scope_Suppress := SST.Save_Scope_Suppress;
7109 Local_Suppress_Stack_Top := SST.Save_Local_Suppress_Stack_Top;
7110 Check_Policy_List := SST.Save_Check_Policy_List;
7111 Default_Pool := SST.Save_Default_Storage_Pool;
7113 if Debug_Flag_W then
7114 Write_Str ("<-- exiting scope: ");
7115 Write_Name (Chars (Current_Scope));
7116 Write_Str (", Depth=");
7117 Write_Int (Int (Scope_Stack.Last));
7121 End_Use_Clauses (SST.First_Use_Clause);
7123 -- If the actions to be wrapped are still there they will get lost
7124 -- causing incomplete code to be generated. It is better to abort in
7125 -- this case (and we do the abort even with assertions off since the
7126 -- penalty is incorrect code generation)
7128 if SST.Actions_To_Be_Wrapped_Before /= No_List
7130 SST.Actions_To_Be_Wrapped_After /= No_List
7132 raise Program_Error;
7135 -- Free last subprogram name if allocated, and pop scope
7137 Free (SST.Last_Subprogram_Name);
7138 Scope_Stack.Decrement_Last;
7145 procedure Push_Scope (S : Entity_Id) is
7146 E : constant Entity_Id := Scope (S);
7149 if Ekind (S) = E_Void then
7152 -- Set scope depth if not a non-concurrent type, and we have not yet set
7153 -- the scope depth. This means that we have the first occurrence of the
7154 -- scope, and this is where the depth is set.
7156 elsif (not Is_Type (S) or else Is_Concurrent_Type (S))
7157 and then not Scope_Depth_Set (S)
7159 if S = Standard_Standard then
7160 Set_Scope_Depth_Value (S, Uint_0);
7162 elsif Is_Child_Unit (S) then
7163 Set_Scope_Depth_Value (S, Uint_1);
7165 elsif not Is_Record_Type (Current_Scope) then
7166 if Ekind (S) = E_Loop then
7167 Set_Scope_Depth_Value (S, Scope_Depth (Current_Scope));
7169 Set_Scope_Depth_Value (S, Scope_Depth (Current_Scope) + 1);
7174 Scope_Stack.Increment_Last;
7177 SST : Scope_Stack_Entry renames Scope_Stack.Table (Scope_Stack.Last);
7181 SST.Save_Scope_Suppress := Scope_Suppress;
7182 SST.Save_Local_Suppress_Stack_Top := Local_Suppress_Stack_Top;
7183 SST.Save_Check_Policy_List := Check_Policy_List;
7184 SST.Save_Default_Storage_Pool := Default_Pool;
7186 if Scope_Stack.Last > Scope_Stack.First then
7187 SST.Component_Alignment_Default := Scope_Stack.Table
7188 (Scope_Stack.Last - 1).
7189 Component_Alignment_Default;
7192 SST.Last_Subprogram_Name := null;
7193 SST.Is_Transient := False;
7194 SST.Node_To_Be_Wrapped := Empty;
7195 SST.Pending_Freeze_Actions := No_List;
7196 SST.Actions_To_Be_Wrapped_Before := No_List;
7197 SST.Actions_To_Be_Wrapped_After := No_List;
7198 SST.First_Use_Clause := Empty;
7199 SST.Is_Active_Stack_Base := False;
7200 SST.Previous_Visibility := False;
7203 if Debug_Flag_W then
7204 Write_Str ("--> new scope: ");
7205 Write_Name (Chars (Current_Scope));
7206 Write_Str (", Id=");
7207 Write_Int (Int (Current_Scope));
7208 Write_Str (", Depth=");
7209 Write_Int (Int (Scope_Stack.Last));
7213 -- Deal with copying flags from the previous scope to this one. This is
7214 -- not necessary if either scope is standard, or if the new scope is a
7217 if S /= Standard_Standard
7218 and then Scope (S) /= Standard_Standard
7219 and then not Is_Child_Unit (S)
7221 if Nkind (E) not in N_Entity then
7225 -- Copy categorization flags from Scope (S) to S, this is not done
7226 -- when Scope (S) is Standard_Standard since propagation is from
7227 -- library unit entity inwards. Copy other relevant attributes as
7228 -- well (Discard_Names in particular).
7230 -- We only propagate inwards for library level entities,
7231 -- inner level subprograms do not inherit the categorization.
7233 if Is_Library_Level_Entity (S) then
7234 Set_Is_Preelaborated (S, Is_Preelaborated (E));
7235 Set_Is_Shared_Passive (S, Is_Shared_Passive (E));
7236 Set_Discard_Names (S, Discard_Names (E));
7237 Set_Suppress_Value_Tracking_On_Call
7238 (S, Suppress_Value_Tracking_On_Call (E));
7239 Set_Categorization_From_Scope (E => S, Scop => E);
7243 if Is_Child_Unit (S)
7244 and then Present (E)
7245 and then Ekind_In (E, E_Package, E_Generic_Package)
7247 Nkind (Parent (Unit_Declaration_Node (E))) = N_Compilation_Unit
7250 Aux : constant Node_Id :=
7251 Aux_Decls_Node (Parent (Unit_Declaration_Node (E)));
7253 if Present (Default_Storage_Pool (Aux)) then
7254 Default_Pool := Default_Storage_Pool (Aux);
7260 ---------------------
7261 -- Premature_Usage --
7262 ---------------------
7264 procedure Premature_Usage (N : Node_Id) is
7265 Kind : constant Node_Kind := Nkind (Parent (Entity (N)));
7266 E : Entity_Id := Entity (N);
7269 -- Within an instance, the analysis of the actual for a formal object
7270 -- does not see the name of the object itself. This is significant only
7271 -- if the object is an aggregate, where its analysis does not do any
7272 -- name resolution on component associations. (see 4717-008). In such a
7273 -- case, look for the visible homonym on the chain.
7276 and then Present (Homonym (E))
7281 and then not In_Open_Scopes (Scope (E))
7288 Set_Etype (N, Etype (E));
7293 if Kind = N_Component_Declaration then
7295 ("component&! cannot be used before end of record declaration", N);
7297 elsif Kind = N_Parameter_Specification then
7299 ("formal parameter&! cannot be used before end of specification",
7302 elsif Kind = N_Discriminant_Specification then
7304 ("discriminant&! cannot be used before end of discriminant part",
7307 elsif Kind = N_Procedure_Specification
7308 or else Kind = N_Function_Specification
7311 ("subprogram&! cannot be used before end of its declaration",
7314 elsif Kind = N_Full_Type_Declaration then
7316 ("type& cannot be used before end of its declaration!", N);
7320 ("object& cannot be used before end of its declaration!", N);
7322 end Premature_Usage;
7324 ------------------------
7325 -- Present_System_Aux --
7326 ------------------------
7328 function Present_System_Aux (N : Node_Id := Empty) return Boolean is
7330 Aux_Name : Unit_Name_Type;
7331 Unum : Unit_Number_Type;
7336 function Find_System (C_Unit : Node_Id) return Entity_Id;
7337 -- Scan context clause of compilation unit to find with_clause
7344 function Find_System (C_Unit : Node_Id) return Entity_Id is
7345 With_Clause : Node_Id;
7348 With_Clause := First (Context_Items (C_Unit));
7349 while Present (With_Clause) loop
7350 if (Nkind (With_Clause) = N_With_Clause
7351 and then Chars (Name (With_Clause)) = Name_System)
7352 and then Comes_From_Source (With_Clause)
7363 -- Start of processing for Present_System_Aux
7366 -- The child unit may have been loaded and analyzed already
7368 if Present (System_Aux_Id) then
7371 -- If no previous pragma for System.Aux, nothing to load
7373 elsif No (System_Extend_Unit) then
7376 -- Use the unit name given in the pragma to retrieve the unit.
7377 -- Verify that System itself appears in the context clause of the
7378 -- current compilation. If System is not present, an error will
7379 -- have been reported already.
7382 With_Sys := Find_System (Cunit (Current_Sem_Unit));
7384 The_Unit := Unit (Cunit (Current_Sem_Unit));
7388 (Nkind (The_Unit) = N_Package_Body
7389 or else (Nkind (The_Unit) = N_Subprogram_Body
7391 not Acts_As_Spec (Cunit (Current_Sem_Unit))))
7393 With_Sys := Find_System (Library_Unit (Cunit (Current_Sem_Unit)));
7397 and then Present (N)
7399 -- If we are compiling a subunit, we need to examine its
7400 -- context as well (Current_Sem_Unit is the parent unit);
7402 The_Unit := Parent (N);
7403 while Nkind (The_Unit) /= N_Compilation_Unit loop
7404 The_Unit := Parent (The_Unit);
7407 if Nkind (Unit (The_Unit)) = N_Subunit then
7408 With_Sys := Find_System (The_Unit);
7412 if No (With_Sys) then
7416 Loc := Sloc (With_Sys);
7417 Get_Name_String (Chars (Expression (System_Extend_Unit)));
7418 Name_Buffer (8 .. Name_Len + 7) := Name_Buffer (1 .. Name_Len);
7419 Name_Buffer (1 .. 7) := "system.";
7420 Name_Buffer (Name_Len + 8) := '%';
7421 Name_Buffer (Name_Len + 9) := 's';
7422 Name_Len := Name_Len + 9;
7423 Aux_Name := Name_Find;
7427 (Load_Name => Aux_Name,
7430 Error_Node => With_Sys);
7432 if Unum /= No_Unit then
7433 Semantics (Cunit (Unum));
7435 Defining_Entity (Specification (Unit (Cunit (Unum))));
7438 Make_With_Clause (Loc,
7440 Make_Expanded_Name (Loc,
7441 Chars => Chars (System_Aux_Id),
7442 Prefix => New_Reference_To (Scope (System_Aux_Id), Loc),
7443 Selector_Name => New_Reference_To (System_Aux_Id, Loc)));
7445 Set_Entity (Name (Withn), System_Aux_Id);
7447 Set_Library_Unit (Withn, Cunit (Unum));
7448 Set_Corresponding_Spec (Withn, System_Aux_Id);
7449 Set_First_Name (Withn, True);
7450 Set_Implicit_With (Withn, True);
7452 Insert_After (With_Sys, Withn);
7453 Mark_Rewrite_Insertion (Withn);
7454 Set_Context_Installed (Withn);
7458 -- Here if unit load failed
7461 Error_Msg_Name_1 := Name_System;
7462 Error_Msg_Name_2 := Chars (Expression (System_Extend_Unit));
7464 ("extension package `%.%` does not exist",
7465 Opt.System_Extend_Unit);
7469 end Present_System_Aux;
7471 -------------------------
7472 -- Restore_Scope_Stack --
7473 -------------------------
7475 procedure Restore_Scope_Stack (Handle_Use : Boolean := True) is
7478 Comp_Unit : Node_Id;
7479 In_Child : Boolean := False;
7480 Full_Vis : Boolean := True;
7481 SS_Last : constant Int := Scope_Stack.Last;
7484 -- Restore visibility of previous scope stack, if any
7486 for J in reverse 0 .. Scope_Stack.Last loop
7487 exit when Scope_Stack.Table (J).Entity = Standard_Standard
7488 or else No (Scope_Stack.Table (J).Entity);
7490 S := Scope_Stack.Table (J).Entity;
7492 if not Is_Hidden_Open_Scope (S) then
7494 -- If the parent scope is hidden, its entities are hidden as
7495 -- well, unless the entity is the instantiation currently
7498 if not Is_Hidden_Open_Scope (Scope (S))
7499 or else not Analyzed (Parent (S))
7500 or else Scope (S) = Standard_Standard
7502 Set_Is_Immediately_Visible (S, True);
7505 E := First_Entity (S);
7506 while Present (E) loop
7507 if Is_Child_Unit (E) then
7508 if not From_With_Type (E) then
7509 Set_Is_Immediately_Visible (E,
7510 Is_Visible_Child_Unit (E) or else In_Open_Scopes (E));
7514 (Nkind (Parent (E)) = N_Defining_Program_Unit_Name
7516 Nkind (Parent (Parent (E))) = N_Package_Specification);
7517 Set_Is_Immediately_Visible (E,
7518 Limited_View_Installed (Parent (Parent (E))));
7521 Set_Is_Immediately_Visible (E, True);
7527 and then Is_Package_Or_Generic_Package (S)
7529 -- We are in the visible part of the package scope
7531 exit when E = First_Private_Entity (S);
7535 -- The visibility of child units (siblings of current compilation)
7536 -- must be restored in any case. Their declarations may appear
7537 -- after the private part of the parent.
7539 if not Full_Vis then
7540 while Present (E) loop
7541 if Is_Child_Unit (E) then
7542 Set_Is_Immediately_Visible (E,
7543 Is_Visible_Child_Unit (E) or else In_Open_Scopes (E));
7551 if Is_Child_Unit (S)
7552 and not In_Child -- check only for current unit
7556 -- Restore visibility of parents according to whether the child
7557 -- is private and whether we are in its visible part.
7559 Comp_Unit := Parent (Unit_Declaration_Node (S));
7561 if Nkind (Comp_Unit) = N_Compilation_Unit
7562 and then Private_Present (Comp_Unit)
7566 elsif Is_Package_Or_Generic_Package (S)
7567 and then (In_Private_Part (S) or else In_Package_Body (S))
7571 -- if S is the scope of some instance (which has already been
7572 -- seen on the stack) it does not affect the visibility of
7575 elsif Is_Hidden_Open_Scope (S) then
7578 elsif (Ekind (S) = E_Procedure
7579 or else Ekind (S) = E_Function)
7580 and then Has_Completion (S)
7591 if SS_Last >= Scope_Stack.First
7592 and then Scope_Stack.Table (SS_Last).Entity /= Standard_Standard
7595 Install_Use_Clauses (Scope_Stack.Table (SS_Last).First_Use_Clause);
7597 end Restore_Scope_Stack;
7599 ----------------------
7600 -- Save_Scope_Stack --
7601 ----------------------
7603 procedure Save_Scope_Stack (Handle_Use : Boolean := True) is
7606 SS_Last : constant Int := Scope_Stack.Last;
7609 if SS_Last >= Scope_Stack.First
7610 and then Scope_Stack.Table (SS_Last).Entity /= Standard_Standard
7613 End_Use_Clauses (Scope_Stack.Table (SS_Last).First_Use_Clause);
7616 -- If the call is from within a compilation unit, as when called from
7617 -- Rtsfind, make current entries in scope stack invisible while we
7618 -- analyze the new unit.
7620 for J in reverse 0 .. SS_Last loop
7621 exit when Scope_Stack.Table (J).Entity = Standard_Standard
7622 or else No (Scope_Stack.Table (J).Entity);
7624 S := Scope_Stack.Table (J).Entity;
7625 Set_Is_Immediately_Visible (S, False);
7627 E := First_Entity (S);
7628 while Present (E) loop
7629 Set_Is_Immediately_Visible (E, False);
7635 end Save_Scope_Stack;
7641 procedure Set_Use (L : List_Id) is
7643 Pack_Name : Node_Id;
7650 while Present (Decl) loop
7651 if Nkind (Decl) = N_Use_Package_Clause then
7652 Chain_Use_Clause (Decl);
7654 Pack_Name := First (Names (Decl));
7655 while Present (Pack_Name) loop
7656 Pack := Entity (Pack_Name);
7658 if Ekind (Pack) = E_Package
7659 and then Applicable_Use (Pack_Name)
7661 Use_One_Package (Pack, Decl);
7667 elsif Nkind (Decl) = N_Use_Type_Clause then
7668 Chain_Use_Clause (Decl);
7670 Id := First (Subtype_Marks (Decl));
7671 while Present (Id) loop
7672 if Entity (Id) /= Any_Type then
7685 ---------------------
7686 -- Use_One_Package --
7687 ---------------------
7689 procedure Use_One_Package (P : Entity_Id; N : Node_Id) is
7692 Current_Instance : Entity_Id := Empty;
7694 Private_With_OK : Boolean := False;
7697 if Ekind (P) /= E_Package then
7702 Set_Current_Use_Clause (P, N);
7704 -- Ada 2005 (AI-50217): Check restriction
7706 if From_With_Type (P) then
7707 Error_Msg_N ("limited withed package cannot appear in use clause", N);
7710 -- Find enclosing instance, if any
7713 Current_Instance := Current_Scope;
7714 while not Is_Generic_Instance (Current_Instance) loop
7715 Current_Instance := Scope (Current_Instance);
7718 if No (Hidden_By_Use_Clause (N)) then
7719 Set_Hidden_By_Use_Clause (N, New_Elmt_List);
7723 -- If unit is a package renaming, indicate that the renamed
7724 -- package is also in use (the flags on both entities must
7725 -- remain consistent, and a subsequent use of either of them
7726 -- should be recognized as redundant).
7728 if Present (Renamed_Object (P)) then
7729 Set_In_Use (Renamed_Object (P));
7730 Set_Current_Use_Clause (Renamed_Object (P), N);
7731 Real_P := Renamed_Object (P);
7736 -- Ada 2005 (AI-262): Check the use_clause of a private withed package
7737 -- found in the private part of a package specification
7739 if In_Private_Part (Current_Scope)
7740 and then Has_Private_With (P)
7741 and then Is_Child_Unit (Current_Scope)
7742 and then Is_Child_Unit (P)
7743 and then Is_Ancestor_Package (Scope (Current_Scope), P)
7745 Private_With_OK := True;
7748 -- Loop through entities in one package making them potentially
7751 Id := First_Entity (P);
7753 and then (Id /= First_Private_Entity (P)
7754 or else Private_With_OK) -- Ada 2005 (AI-262)
7756 Prev := Current_Entity (Id);
7757 while Present (Prev) loop
7758 if Is_Immediately_Visible (Prev)
7759 and then (not Is_Overloadable (Prev)
7760 or else not Is_Overloadable (Id)
7761 or else (Type_Conformant (Id, Prev)))
7763 if No (Current_Instance) then
7765 -- Potentially use-visible entity remains hidden
7767 goto Next_Usable_Entity;
7769 -- A use clause within an instance hides outer global entities,
7770 -- which are not used to resolve local entities in the
7771 -- instance. Note that the predefined entities in Standard
7772 -- could not have been hidden in the generic by a use clause,
7773 -- and therefore remain visible. Other compilation units whose
7774 -- entities appear in Standard must be hidden in an instance.
7776 -- To determine whether an entity is external to the instance
7777 -- we compare the scope depth of its scope with that of the
7778 -- current instance. However, a generic actual of a subprogram
7779 -- instance is declared in the wrapper package but will not be
7780 -- hidden by a use-visible entity. similarly, an entity that is
7781 -- declared in an enclosing instance will not be hidden by an
7782 -- an entity declared in a generic actual, which can only have
7783 -- been use-visible in the generic and will not have hidden the
7784 -- entity in the generic parent.
7786 -- If Id is called Standard, the predefined package with the
7787 -- same name is in the homonym chain. It has to be ignored
7788 -- because it has no defined scope (being the only entity in
7789 -- the system with this mandated behavior).
7791 elsif not Is_Hidden (Id)
7792 and then Present (Scope (Prev))
7793 and then not Is_Wrapper_Package (Scope (Prev))
7794 and then Scope_Depth (Scope (Prev)) <
7795 Scope_Depth (Current_Instance)
7796 and then (Scope (Prev) /= Standard_Standard
7797 or else Sloc (Prev) > Standard_Location)
7799 if In_Open_Scopes (Scope (Prev))
7800 and then Is_Generic_Instance (Scope (Prev))
7801 and then Present (Associated_Formal_Package (P))
7806 Set_Is_Potentially_Use_Visible (Id);
7807 Set_Is_Immediately_Visible (Prev, False);
7808 Append_Elmt (Prev, Hidden_By_Use_Clause (N));
7812 -- A user-defined operator is not use-visible if the predefined
7813 -- operator for the type is immediately visible, which is the case
7814 -- if the type of the operand is in an open scope. This does not
7815 -- apply to user-defined operators that have operands of different
7816 -- types, because the predefined mixed mode operations (multiply
7817 -- and divide) apply to universal types and do not hide anything.
7819 elsif Ekind (Prev) = E_Operator
7820 and then Operator_Matches_Spec (Prev, Id)
7821 and then In_Open_Scopes
7822 (Scope (Base_Type (Etype (First_Formal (Id)))))
7823 and then (No (Next_Formal (First_Formal (Id)))
7824 or else Etype (First_Formal (Id))
7825 = Etype (Next_Formal (First_Formal (Id)))
7826 or else Chars (Prev) = Name_Op_Expon)
7828 goto Next_Usable_Entity;
7830 -- In an instance, two homonyms may become use_visible through the
7831 -- actuals of distinct formal packages. In the generic, only the
7832 -- current one would have been visible, so make the other one
7835 elsif Present (Current_Instance)
7836 and then Is_Potentially_Use_Visible (Prev)
7837 and then not Is_Overloadable (Prev)
7838 and then Scope (Id) /= Scope (Prev)
7839 and then Used_As_Generic_Actual (Scope (Prev))
7840 and then Used_As_Generic_Actual (Scope (Id))
7841 and then not In_Same_List (Current_Use_Clause (Scope (Prev)),
7842 Current_Use_Clause (Scope (Id)))
7844 Set_Is_Potentially_Use_Visible (Prev, False);
7845 Append_Elmt (Prev, Hidden_By_Use_Clause (N));
7848 Prev := Homonym (Prev);
7851 -- On exit, we know entity is not hidden, unless it is private
7853 if not Is_Hidden (Id)
7854 and then ((not Is_Child_Unit (Id))
7855 or else Is_Visible_Child_Unit (Id))
7857 Set_Is_Potentially_Use_Visible (Id);
7859 if Is_Private_Type (Id)
7860 and then Present (Full_View (Id))
7862 Set_Is_Potentially_Use_Visible (Full_View (Id));
7866 <<Next_Usable_Entity>>
7870 -- Child units are also made use-visible by a use clause, but they may
7871 -- appear after all visible declarations in the parent entity list.
7873 while Present (Id) loop
7874 if Is_Child_Unit (Id)
7875 and then Is_Visible_Child_Unit (Id)
7877 Set_Is_Potentially_Use_Visible (Id);
7883 if Chars (Real_P) = Name_System
7884 and then Scope (Real_P) = Standard_Standard
7885 and then Present_System_Aux (N)
7887 Use_One_Package (System_Aux_Id, N);
7890 end Use_One_Package;
7896 procedure Use_One_Type (Id : Node_Id; Installed : Boolean := False) is
7898 Is_Known_Used : Boolean;
7902 function Spec_Reloaded_For_Body return Boolean;
7903 -- Determine whether the compilation unit is a package body and the use
7904 -- type clause is in the spec of the same package. Even though the spec
7905 -- was analyzed first, its context is reloaded when analysing the body.
7907 procedure Use_Class_Wide_Operations (Typ : Entity_Id);
7908 -- AI05-150: if the use_type_clause carries the "all" qualifier,
7909 -- class-wide operations of ancestor types are use-visible if the
7910 -- ancestor type is visible.
7912 ----------------------------
7913 -- Spec_Reloaded_For_Body --
7914 ----------------------------
7916 function Spec_Reloaded_For_Body return Boolean is
7918 if Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Body then
7920 Spec : constant Node_Id :=
7921 Parent (List_Containing (Parent (Id)));
7924 Nkind (Spec) = N_Package_Specification
7925 and then Corresponding_Body (Parent (Spec)) =
7926 Cunit_Entity (Current_Sem_Unit);
7931 end Spec_Reloaded_For_Body;
7933 -------------------------------
7934 -- Use_Class_Wide_Operations --
7935 -------------------------------
7937 procedure Use_Class_Wide_Operations (Typ : Entity_Id) is
7941 function Is_Class_Wide_Operation_Of
7943 T : Entity_Id) return Boolean;
7944 -- Determine whether a subprogram has a class-wide parameter or
7945 -- result that is T'Class.
7947 ---------------------------------
7948 -- Is_Class_Wide_Operation_Of --
7949 ---------------------------------
7951 function Is_Class_Wide_Operation_Of
7953 T : Entity_Id) return Boolean
7958 Formal := First_Formal (Op);
7959 while Present (Formal) loop
7960 if Etype (Formal) = Class_Wide_Type (T) then
7963 Next_Formal (Formal);
7966 if Etype (Op) = Class_Wide_Type (T) then
7971 end Is_Class_Wide_Operation_Of;
7973 -- Start of processing for Use_Class_Wide_Operations
7976 Scop := Scope (Typ);
7977 if not Is_Hidden (Scop) then
7978 Ent := First_Entity (Scop);
7979 while Present (Ent) loop
7980 if Is_Overloadable (Ent)
7981 and then Is_Class_Wide_Operation_Of (Ent, Typ)
7982 and then not Is_Potentially_Use_Visible (Ent)
7984 Set_Is_Potentially_Use_Visible (Ent);
7985 Append_Elmt (Ent, Used_Operations (Parent (Id)));
7992 if Is_Derived_Type (Typ) then
7993 Use_Class_Wide_Operations (Etype (Base_Type (Typ)));
7995 end Use_Class_Wide_Operations;
7997 -- Start of processing for Use_One_Type;
8000 -- It is the type determined by the subtype mark (8.4(8)) whose
8001 -- operations become potentially use-visible.
8003 T := Base_Type (Entity (Id));
8005 -- Either the type itself is used, the package where it is declared
8006 -- is in use or the entity is declared in the current package, thus
8011 or else In_Use (Scope (T))
8012 or else Scope (T) = Current_Scope;
8014 Set_Redundant_Use (Id,
8015 Is_Known_Used or else Is_Potentially_Use_Visible (T));
8017 if Ekind (T) = E_Incomplete_Type then
8018 Error_Msg_N ("premature usage of incomplete type", Id);
8020 elsif In_Open_Scopes (Scope (T)) then
8023 -- A limited view cannot appear in a use_type clause. However, an access
8024 -- type whose designated type is limited has the flag but is not itself
8025 -- a limited view unless we only have a limited view of its enclosing
8028 elsif From_With_Type (T)
8029 and then From_With_Type (Scope (T))
8032 ("incomplete type from limited view "
8033 & "cannot appear in use clause", Id);
8035 -- If the subtype mark designates a subtype in a different package,
8036 -- we have to check that the parent type is visible, otherwise the
8037 -- use type clause is a noop. Not clear how to do that???
8039 elsif not Redundant_Use (Id) then
8042 -- If T is tagged, primitive operators on class-wide operands
8043 -- are also available.
8045 if Is_Tagged_Type (T) then
8046 Set_In_Use (Class_Wide_Type (T));
8049 Set_Current_Use_Clause (T, Parent (Id));
8051 -- Iterate over primitive operations of the type. If an operation is
8052 -- already use_visible, it is the result of a previous use_clause,
8053 -- and already appears on the corresponding entity chain. If the
8054 -- clause is being reinstalled, operations are already use-visible.
8060 Op_List := Collect_Primitive_Operations (T);
8061 Elmt := First_Elmt (Op_List);
8062 while Present (Elmt) loop
8063 if (Nkind (Node (Elmt)) = N_Defining_Operator_Symbol
8064 or else Chars (Node (Elmt)) in Any_Operator_Name)
8065 and then not Is_Hidden (Node (Elmt))
8066 and then not Is_Potentially_Use_Visible (Node (Elmt))
8068 Set_Is_Potentially_Use_Visible (Node (Elmt));
8069 Append_Elmt (Node (Elmt), Used_Operations (Parent (Id)));
8071 elsif Ada_Version >= Ada_2012
8072 and then All_Present (Parent (Id))
8073 and then not Is_Hidden (Node (Elmt))
8074 and then not Is_Potentially_Use_Visible (Node (Elmt))
8076 Set_Is_Potentially_Use_Visible (Node (Elmt));
8077 Append_Elmt (Node (Elmt), Used_Operations (Parent (Id)));
8084 if Ada_Version >= Ada_2012
8085 and then All_Present (Parent (Id))
8086 and then Is_Tagged_Type (T)
8088 Use_Class_Wide_Operations (T);
8092 -- If warning on redundant constructs, check for unnecessary WITH
8094 if Warn_On_Redundant_Constructs
8095 and then Is_Known_Used
8097 -- with P; with P; use P;
8098 -- package P is package X is package body X is
8099 -- type T ... use P.T;
8101 -- The compilation unit is the body of X. GNAT first compiles the
8102 -- spec of X, then proceeds to the body. At that point P is marked
8103 -- as use visible. The analysis then reinstalls the spec along with
8104 -- its context. The use clause P.T is now recognized as redundant,
8105 -- but in the wrong context. Do not emit a warning in such cases.
8106 -- Do not emit a warning either if we are in an instance, there is
8107 -- no redundancy between an outer use_clause and one that appears
8108 -- within the generic.
8110 and then not Spec_Reloaded_For_Body
8111 and then not In_Instance
8113 -- The type already has a use clause
8117 -- Case where we know the current use clause for the type
8119 if Present (Current_Use_Clause (T)) then
8120 Use_Clause_Known : declare
8121 Clause1 : constant Node_Id := Parent (Id);
8122 Clause2 : constant Node_Id := Current_Use_Clause (T);
8129 function Entity_Of_Unit (U : Node_Id) return Entity_Id;
8130 -- Return the appropriate entity for determining which unit
8131 -- has a deeper scope: the defining entity for U, unless U
8132 -- is a package instance, in which case we retrieve the
8133 -- entity of the instance spec.
8135 --------------------
8136 -- Entity_Of_Unit --
8137 --------------------
8139 function Entity_Of_Unit (U : Node_Id) return Entity_Id is
8141 if Nkind (U) = N_Package_Instantiation
8142 and then Analyzed (U)
8144 return Defining_Entity (Instance_Spec (U));
8146 return Defining_Entity (U);
8150 -- Start of processing for Use_Clause_Known
8153 -- If both current use type clause and the use type clause
8154 -- for the type are at the compilation unit level, one of
8155 -- the units must be an ancestor of the other, and the
8156 -- warning belongs on the descendant.
8158 if Nkind (Parent (Clause1)) = N_Compilation_Unit
8160 Nkind (Parent (Clause2)) = N_Compilation_Unit
8163 -- If the unit is a subprogram body that acts as spec,
8164 -- the context clause is shared with the constructed
8165 -- subprogram spec. Clearly there is no redundancy.
8167 if Clause1 = Clause2 then
8171 Unit1 := Unit (Parent (Clause1));
8172 Unit2 := Unit (Parent (Clause2));
8174 -- If both clauses are on same unit, or one is the body
8175 -- of the other, or one of them is in a subunit, report
8176 -- redundancy on the later one.
8178 if Unit1 = Unit2 then
8179 Error_Msg_Sloc := Sloc (Current_Use_Clause (T));
8180 Error_Msg_NE -- CODEFIX
8181 ("& is already use-visible through previous "
8182 & "use_type_clause #?", Clause1, T);
8185 elsif Nkind (Unit1) = N_Subunit 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_In (Unit2, N_Package_Body, N_Subprogram_Body)
8193 and then Nkind (Unit1) /= Nkind (Unit2)
8194 and then Nkind (Unit1) /= N_Subunit
8196 Error_Msg_Sloc := Sloc (Clause1);
8197 Error_Msg_NE -- CODEFIX
8198 ("& is already use-visible through previous "
8199 & "use_type_clause #?", Current_Use_Clause (T), T);
8203 -- There is a redundant use type clause in a child unit.
8204 -- Determine which of the units is more deeply nested.
8205 -- If a unit is a package instance, retrieve the entity
8206 -- and its scope from the instance spec.
8208 Ent1 := Entity_Of_Unit (Unit1);
8209 Ent2 := Entity_Of_Unit (Unit2);
8211 if Scope (Ent2) = Standard_Standard then
8212 Error_Msg_Sloc := Sloc (Current_Use_Clause (T));
8215 elsif Scope (Ent1) = Standard_Standard then
8216 Error_Msg_Sloc := Sloc (Id);
8219 -- If both units are child units, we determine which one
8220 -- is the descendant by the scope distance to the
8221 -- ultimate parent unit.
8231 and then Present (S2)
8232 and then S1 /= Standard_Standard
8233 and then S2 /= Standard_Standard
8239 if S1 = Standard_Standard then
8240 Error_Msg_Sloc := Sloc (Id);
8243 Error_Msg_Sloc := Sloc (Current_Use_Clause (T));
8249 Error_Msg_NE -- CODEFIX
8250 ("& is already use-visible through previous "
8251 & "use_type_clause #?", Err_No, Id);
8253 -- Case where current use type clause and the use type
8254 -- clause for the type are not both at the compilation unit
8255 -- level. In this case we don't have location information.
8258 Error_Msg_NE -- CODEFIX
8259 ("& is already use-visible through previous "
8260 & "use type clause?", Id, T);
8262 end Use_Clause_Known;
8264 -- Here if Current_Use_Clause is not set for T, another case
8265 -- where we do not have the location information available.
8268 Error_Msg_NE -- CODEFIX
8269 ("& is already use-visible through previous "
8270 & "use type clause?", Id, T);
8273 -- The package where T is declared is already used
8275 elsif In_Use (Scope (T)) then
8276 Error_Msg_Sloc := Sloc (Current_Use_Clause (Scope (T)));
8277 Error_Msg_NE -- CODEFIX
8278 ("& is already use-visible through package use clause #?",
8281 -- The current scope is the package where T is declared
8284 Error_Msg_Node_2 := Scope (T);
8285 Error_Msg_NE -- CODEFIX
8286 ("& is already use-visible inside package &?", Id, T);
8295 procedure Write_Info is
8296 Id : Entity_Id := First_Entity (Current_Scope);
8299 -- No point in dumping standard entities
8301 if Current_Scope = Standard_Standard then
8305 Write_Str ("========================================================");
8307 Write_Str (" Defined Entities in ");
8308 Write_Name (Chars (Current_Scope));
8310 Write_Str ("========================================================");
8314 Write_Str ("-- none --");
8318 while Present (Id) loop
8319 Write_Entity_Info (Id, " ");
8324 if Scope (Current_Scope) = Standard_Standard then
8326 -- Print information on the current unit itself
8328 Write_Entity_Info (Current_Scope, " ");
8341 for J in reverse 1 .. Scope_Stack.Last loop
8342 S := Scope_Stack.Table (J).Entity;
8343 Write_Int (Int (S));
8344 Write_Str (" === ");
8345 Write_Name (Chars (S));
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