1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2011, Free Software Foundation, Inc. --
11 -- GNAT is free software; you can redistribute it and/or modify it under --
12 -- terms of the GNU General Public License as published by the Free Soft- --
13 -- ware Foundation; either version 3, or (at your option) any later ver- --
14 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
15 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
16 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
17 -- for more details. You should have received a copy of the GNU General --
18 -- Public License distributed with GNAT; see file COPYING3. If not, go to --
19 -- http://www.gnu.org/licenses for a complete copy of the license. --
21 -- GNAT was originally developed by the GNAT team at New York University. --
22 -- Extensive contributions were provided by Ada Core Technologies Inc. --
24 ------------------------------------------------------------------------------
26 with Atree; use Atree;
27 with Debug; use Debug;
28 with Einfo; use Einfo;
29 with Elists; use Elists;
30 with Errout; use Errout;
31 with Exp_Tss; use Exp_Tss;
32 with Exp_Util; use Exp_Util;
33 with Fname; use Fname;
34 with Freeze; use Freeze;
35 with Impunit; use Impunit;
37 with Lib.Load; use Lib.Load;
38 with Lib.Xref; use Lib.Xref;
39 with Namet; use Namet;
40 with Namet.Sp; use Namet.Sp;
41 with Nlists; use Nlists;
42 with Nmake; use Nmake;
44 with Output; use Output;
45 with Restrict; use Restrict;
46 with Rident; use Rident;
47 with Rtsfind; use Rtsfind;
49 with Sem_Aux; use Sem_Aux;
50 with Sem_Cat; use Sem_Cat;
51 with Sem_Ch3; use Sem_Ch3;
52 with Sem_Ch4; use Sem_Ch4;
53 with Sem_Ch6; use Sem_Ch6;
54 with Sem_Ch12; use Sem_Ch12;
55 with Sem_Disp; use Sem_Disp;
56 with Sem_Dist; use Sem_Dist;
57 with Sem_Eval; use Sem_Eval;
58 with Sem_Res; use Sem_Res;
59 with Sem_Util; use Sem_Util;
60 with Sem_Type; use Sem_Type;
61 with Stand; use Stand;
62 with Sinfo; use Sinfo;
63 with Sinfo.CN; use Sinfo.CN;
64 with Snames; use Snames;
65 with Style; use Style;
67 with Targparm; use Targparm;
68 with Tbuild; use Tbuild;
69 with Uintp; use Uintp;
71 package body Sem_Ch8 is
73 ------------------------------------
74 -- Visibility and Name Resolution --
75 ------------------------------------
77 -- This package handles name resolution and the collection of possible
78 -- interpretations for overloaded names, prior to overload resolution.
80 -- Name resolution is the process that establishes a mapping between source
81 -- identifiers and the entities they denote at each point in the program.
82 -- Each entity is represented by a defining occurrence. Each identifier
83 -- that denotes an entity points to the corresponding defining occurrence.
84 -- This is the entity of the applied occurrence. Each occurrence holds
85 -- an index into the names table, where source identifiers are stored.
87 -- Each entry in the names table for an identifier or designator uses the
88 -- Info pointer to hold a link to the currently visible entity that has
89 -- this name (see subprograms Get_Name_Entity_Id and Set_Name_Entity_Id
90 -- in package Sem_Util). The visibility is initialized at the beginning of
91 -- semantic processing to make entities in package Standard immediately
92 -- visible. The visibility table is used in a more subtle way when
93 -- compiling subunits (see below).
95 -- Entities that have the same name (i.e. homonyms) are chained. In the
96 -- case of overloaded entities, this chain holds all the possible meanings
97 -- of a given identifier. The process of overload resolution uses type
98 -- information to select from this chain the unique meaning of a given
101 -- Entities are also chained in their scope, through the Next_Entity link.
102 -- As a consequence, the name space is organized as a sparse matrix, where
103 -- each row corresponds to a scope, and each column to a source identifier.
104 -- Open scopes, that is to say scopes currently being compiled, have their
105 -- corresponding rows of entities in order, innermost scope first.
107 -- The scopes of packages that are mentioned in context clauses appear in
108 -- no particular order, interspersed among open scopes. This is because
109 -- in the course of analyzing the context of a compilation, a package
110 -- declaration is first an open scope, and subsequently an element of the
111 -- context. If subunits or child units are present, a parent unit may
112 -- appear under various guises at various times in the compilation.
114 -- When the compilation of the innermost scope is complete, the entities
115 -- defined therein are no longer visible. If the scope is not a package
116 -- declaration, these entities are never visible subsequently, and can be
117 -- removed from visibility chains. If the scope is a package declaration,
118 -- its visible declarations may still be accessible. Therefore the entities
119 -- defined in such a scope are left on the visibility chains, and only
120 -- their visibility (immediately visibility or potential use-visibility)
123 -- The ordering of homonyms on their chain does not necessarily follow
124 -- the order of their corresponding scopes on the scope stack. For
125 -- example, if package P and the enclosing scope both contain entities
126 -- named E, then when compiling the package body the chain for E will
127 -- hold the global entity first, and the local one (corresponding to
128 -- the current inner scope) next. As a result, name resolution routines
129 -- do not assume any relative ordering of the homonym chains, either
130 -- for scope nesting or to order of appearance of context clauses.
132 -- When compiling a child unit, entities in the parent scope are always
133 -- immediately visible. When compiling the body of a child unit, private
134 -- entities in the parent must also be made immediately visible. There
135 -- are separate routines to make the visible and private declarations
136 -- visible at various times (see package Sem_Ch7).
138 -- +--------+ +-----+
139 -- | In use |-------->| EU1 |-------------------------->
140 -- +--------+ +-----+
142 -- +--------+ +-----+ +-----+
143 -- | Stand. |---------------->| ES1 |--------------->| ES2 |--->
144 -- +--------+ +-----+ +-----+
146 -- +---------+ | +-----+
147 -- | with'ed |------------------------------>| EW2 |--->
148 -- +---------+ | +-----+
150 -- +--------+ +-----+ +-----+
151 -- | Scope2 |---------------->| E12 |--------------->| E22 |--->
152 -- +--------+ +-----+ +-----+
154 -- +--------+ +-----+ +-----+
155 -- | Scope1 |---------------->| E11 |--------------->| E12 |--->
156 -- +--------+ +-----+ +-----+
160 -- | | with'ed |----------------------------------------->
164 -- (innermost first) | |
165 -- +----------------------------+
166 -- Names table => | Id1 | | | | Id2 |
167 -- +----------------------------+
169 -- Name resolution must deal with several syntactic forms: simple names,
170 -- qualified names, indexed names, and various forms of calls.
172 -- Each identifier points to an entry in the names table. The resolution
173 -- of a simple name consists in traversing the homonym chain, starting
174 -- from the names table. If an entry is immediately visible, it is the one
175 -- designated by the identifier. If only potentially use-visible entities
176 -- are on the chain, we must verify that they do not hide each other. If
177 -- the entity we find is overloadable, we collect all other overloadable
178 -- entities on the chain as long as they are not hidden.
180 -- To resolve expanded names, we must find the entity at the intersection
181 -- of the entity chain for the scope (the prefix) and the homonym chain
182 -- for the selector. In general, homonym chains will be much shorter than
183 -- entity chains, so it is preferable to start from the names table as
184 -- well. If the entity found is overloadable, we must collect all other
185 -- interpretations that are defined in the scope denoted by the prefix.
187 -- For records, protected types, and tasks, their local entities are
188 -- removed from visibility chains on exit from the corresponding scope.
189 -- From the outside, these entities are always accessed by selected
190 -- notation, and the entity chain for the record type, protected type,
191 -- etc. is traversed sequentially in order to find the designated entity.
193 -- The discriminants of a type and the operations of a protected type or
194 -- task are unchained on exit from the first view of the type, (such as
195 -- a private or incomplete type declaration, or a protected type speci-
196 -- fication) and re-chained when compiling the second view.
198 -- In the case of operators, we do not make operators on derived types
199 -- explicit. As a result, the notation P."+" may denote either a user-
200 -- defined function with name "+", or else an implicit declaration of the
201 -- operator "+" in package P. The resolution of expanded names always
202 -- tries to resolve an operator name as such an implicitly defined entity,
203 -- in addition to looking for explicit declarations.
205 -- All forms of names that denote entities (simple names, expanded names,
206 -- character literals in some cases) have a Entity attribute, which
207 -- identifies the entity denoted by the name.
209 ---------------------
210 -- The Scope Stack --
211 ---------------------
213 -- The Scope stack keeps track of the scopes currently been compiled.
214 -- Every entity that contains declarations (including records) is placed
215 -- on the scope stack while it is being processed, and removed at the end.
216 -- Whenever a non-package scope is exited, the entities defined therein
217 -- are removed from the visibility table, so that entities in outer scopes
218 -- become visible (see previous description). On entry to Sem, the scope
219 -- stack only contains the package Standard. As usual, subunits complicate
220 -- this picture ever so slightly.
222 -- The Rtsfind mechanism can force a call to Semantics while another
223 -- compilation is in progress. The unit retrieved by Rtsfind must be
224 -- compiled in its own context, and has no access to the visibility of
225 -- the unit currently being compiled. The procedures Save_Scope_Stack and
226 -- Restore_Scope_Stack make entities in current open scopes invisible
227 -- before compiling the retrieved unit, and restore the compilation
228 -- environment afterwards.
230 ------------------------
231 -- Compiling subunits --
232 ------------------------
234 -- Subunits must be compiled in the environment of the corresponding stub,
235 -- that is to say with the same visibility into the parent (and its
236 -- context) that is available at the point of the stub declaration, but
237 -- with the additional visibility provided by the context clause of the
238 -- subunit itself. As a result, compilation of a subunit forces compilation
239 -- of the parent (see description in lib-). At the point of the stub
240 -- declaration, Analyze is called recursively to compile the proper body of
241 -- the subunit, but without reinitializing the names table, nor the scope
242 -- stack (i.e. standard is not pushed on the stack). In this fashion the
243 -- context of the subunit is added to the context of the parent, and the
244 -- subunit is compiled in the correct environment. Note that in the course
245 -- of processing the context of a subunit, Standard will appear twice on
246 -- the scope stack: once for the parent of the subunit, and once for the
247 -- unit in the context clause being compiled. However, the two sets of
248 -- entities are not linked by homonym chains, so that the compilation of
249 -- any context unit happens in a fresh visibility environment.
251 -------------------------------
252 -- Processing of USE Clauses --
253 -------------------------------
255 -- Every defining occurrence has a flag indicating if it is potentially use
256 -- visible. Resolution of simple names examines this flag. The processing
257 -- of use clauses consists in setting this flag on all visible entities
258 -- defined in the corresponding package. On exit from the scope of the use
259 -- clause, the corresponding flag must be reset. However, a package may
260 -- appear in several nested use clauses (pathological but legal, alas!)
261 -- which forces us to use a slightly more involved scheme:
263 -- a) The defining occurrence for a package holds a flag -In_Use- to
264 -- indicate that it is currently in the scope of a use clause. If a
265 -- redundant use clause is encountered, then the corresponding occurrence
266 -- of the package name is flagged -Redundant_Use-.
268 -- b) On exit from a scope, the use clauses in its declarative part are
269 -- scanned. The visibility flag is reset in all entities declared in
270 -- package named in a use clause, as long as the package is not flagged
271 -- as being in a redundant use clause (in which case the outer use
272 -- clause is still in effect, and the direct visibility of its entities
273 -- must be retained).
275 -- Note that entities are not removed from their homonym chains on exit
276 -- from the package specification. A subsequent use clause does not need
277 -- to rechain the visible entities, but only to establish their direct
280 -----------------------------------
281 -- Handling private declarations --
282 -----------------------------------
284 -- The principle that each entity has a single defining occurrence clashes
285 -- with the presence of two separate definitions for private types: the
286 -- first is the private type declaration, and second is the full type
287 -- declaration. It is important that all references to the type point to
288 -- the same defining occurrence, namely the first one. To enforce the two
289 -- separate views of the entity, the corresponding information is swapped
290 -- between the two declarations. Outside of the package, the defining
291 -- occurrence only contains the private declaration information, while in
292 -- the private part and the body of the package the defining occurrence
293 -- contains the full declaration. To simplify the swap, the defining
294 -- occurrence that currently holds the private declaration points to the
295 -- full declaration. During semantic processing the defining occurrence
296 -- also points to a list of private dependents, that is to say access types
297 -- or composite types whose designated types or component types are
298 -- subtypes or derived types of the private type in question. After the
299 -- full declaration has been seen, the private dependents are updated to
300 -- indicate that they have full definitions.
302 ------------------------------------
303 -- Handling of Undefined Messages --
304 ------------------------------------
306 -- In normal mode, only the first use of an undefined identifier generates
307 -- a message. The table Urefs is used to record error messages that have
308 -- been issued so that second and subsequent ones do not generate further
309 -- messages. However, the second reference causes text to be added to the
310 -- original undefined message noting "(more references follow)". The
311 -- full error list option (-gnatf) forces messages to be generated for
312 -- every reference and disconnects the use of this table.
314 type Uref_Entry is record
316 -- Node for identifier for which original message was posted. The
317 -- Chars field of this identifier is used to detect later references
318 -- to the same identifier.
321 -- Records error message Id of original undefined message. Reset to
322 -- No_Error_Msg after the second occurrence, where it is used to add
323 -- text to the original message as described above.
326 -- Set if the message is not visible rather than undefined
329 -- Records location of error message. Used to make sure that we do
330 -- not consider a, b : undefined as two separate instances, which
331 -- would otherwise happen, since the parser converts this sequence
332 -- to a : undefined; b : undefined.
336 package Urefs is new Table.Table (
337 Table_Component_Type => Uref_Entry,
338 Table_Index_Type => Nat,
339 Table_Low_Bound => 1,
341 Table_Increment => 100,
342 Table_Name => "Urefs");
344 Candidate_Renaming : Entity_Id;
345 -- Holds a candidate interpretation that appears in a subprogram renaming
346 -- declaration and does not match the given specification, but matches at
347 -- least on the first formal. Allows better error message when given
348 -- specification omits defaulted parameters, a common error.
350 -----------------------
351 -- Local Subprograms --
352 -----------------------
354 procedure Analyze_Generic_Renaming
357 -- Common processing for all three kinds of generic renaming declarations.
358 -- Enter new name and indicate that it renames the generic unit.
360 procedure Analyze_Renamed_Character
364 -- Renamed entity is given by a character literal, which must belong
365 -- to the return type of the new entity. Is_Body indicates whether the
366 -- declaration is a renaming_as_body. If the original declaration has
367 -- already been frozen (because of an intervening body, e.g.) the body of
368 -- the function must be built now. The same applies to the following
369 -- various renaming procedures.
371 procedure Analyze_Renamed_Dereference
375 -- Renamed entity is given by an explicit dereference. Prefix must be a
376 -- conformant access_to_subprogram type.
378 procedure Analyze_Renamed_Entry
382 -- If the renamed entity in a subprogram renaming is an entry or protected
383 -- subprogram, build a body for the new entity whose only statement is a
384 -- call to the renamed entity.
386 procedure Analyze_Renamed_Family_Member
390 -- Used when the renamed entity is an indexed component. The prefix must
391 -- denote an entry family.
393 procedure Analyze_Renamed_Primitive_Operation
397 -- If the renamed entity in a subprogram renaming is a primitive operation
398 -- or a class-wide operation in prefix form, save the target object, which
399 -- must be added to the list of actuals in any subsequent call.
401 function Applicable_Use (Pack_Name : Node_Id) return Boolean;
402 -- Common code to Use_One_Package and Set_Use, to determine whether use
403 -- clause must be processed. Pack_Name is an entity name that references
404 -- the package in question.
406 procedure Attribute_Renaming (N : Node_Id);
407 -- Analyze renaming of attribute as subprogram. The renaming declaration N
408 -- is rewritten as a subprogram body that returns the attribute reference
409 -- applied to the formals of the function.
411 procedure Set_Entity_Or_Discriminal (N : Node_Id; E : Entity_Id);
412 -- Set Entity, with style check if need be. For a discriminant reference,
413 -- replace by the corresponding discriminal, i.e. the parameter of the
414 -- initialization procedure that corresponds to the discriminant.
416 procedure Check_Frozen_Renaming (N : Node_Id; Subp : Entity_Id);
417 -- A renaming_as_body may occur after the entity of the original decla-
418 -- ration has been frozen. In that case, the body of the new entity must
419 -- be built now, because the usual mechanism of building the renamed
420 -- body at the point of freezing will not work. Subp is the subprogram
421 -- for which N provides the Renaming_As_Body.
423 procedure Check_In_Previous_With_Clause
426 -- N is a use_package clause and Nam the package name, or N is a use_type
427 -- clause and Nam is the prefix of the type name. In either case, verify
428 -- that the package is visible at that point in the context: either it
429 -- appears in a previous with_clause, or because it is a fully qualified
430 -- name and the root ancestor appears in a previous with_clause.
432 procedure Check_Library_Unit_Renaming (N : Node_Id; Old_E : Entity_Id);
433 -- Verify that the entity in a renaming declaration that is a library unit
434 -- is itself a library unit and not a nested unit or subunit. Also check
435 -- that if the renaming is a child unit of a generic parent, then the
436 -- renamed unit must also be a child unit of that parent. Finally, verify
437 -- that a renamed generic unit is not an implicit child declared within
438 -- an instance of the parent.
440 procedure Chain_Use_Clause (N : Node_Id);
441 -- Chain use clause onto list of uses clauses headed by First_Use_Clause in
442 -- the proper scope table entry. This is usually the current scope, but it
443 -- will be an inner scope when installing the use clauses of the private
444 -- declarations of a parent unit prior to compiling the private part of a
445 -- child unit. This chain is traversed when installing/removing use clauses
446 -- when compiling a subunit or instantiating a generic body on the fly,
447 -- when it is necessary to save and restore full environments.
449 function Has_Implicit_Character_Literal (N : Node_Id) return Boolean;
450 -- Find a type derived from Character or Wide_Character in the prefix of N.
451 -- Used to resolved qualified names whose selector is a character literal.
453 function Has_Private_With (E : Entity_Id) return Boolean;
454 -- Ada 2005 (AI-262): Determines if the current compilation unit has a
455 -- private with on E.
457 procedure Find_Expanded_Name (N : Node_Id);
458 -- The input is a selected component known to be an expanded name. Verify
459 -- legality of selector given the scope denoted by prefix, and change node
460 -- N into a expanded name with a properly set Entity field.
462 function Find_Renamed_Entity
466 Is_Actual : Boolean := False) return Entity_Id;
467 -- Find the renamed entity that corresponds to the given parameter profile
468 -- in a subprogram renaming declaration. The renamed entity may be an
469 -- operator, a subprogram, an entry, or a protected operation. Is_Actual
470 -- indicates that the renaming is the one generated for an actual subpro-
471 -- gram in an instance, for which special visibility checks apply.
473 function Has_Implicit_Operator (N : Node_Id) return Boolean;
474 -- N is an expanded name whose selector is an operator name (e.g. P."+").
475 -- declarative part contains an implicit declaration of an operator if it
476 -- has a declaration of a type to which one of the predefined operators
477 -- apply. The existence of this routine is an implementation artifact. A
478 -- more straightforward but more space-consuming choice would be to make
479 -- all inherited operators explicit in the symbol table.
481 procedure Inherit_Renamed_Profile (New_S : Entity_Id; Old_S : Entity_Id);
482 -- A subprogram defined by a renaming declaration inherits the parameter
483 -- profile of the renamed entity. The subtypes given in the subprogram
484 -- specification are discarded and replaced with those of the renamed
485 -- subprogram, which are then used to recheck the default values.
487 function Is_Appropriate_For_Record (T : Entity_Id) return Boolean;
488 -- Prefix is appropriate for record if it is of a record type, or an access
491 function Is_Appropriate_For_Entry_Prefix (T : Entity_Id) return Boolean;
492 -- True if it is of a task type, a protected type, or else an access to one
495 procedure Note_Redundant_Use (Clause : Node_Id);
496 -- Mark the name in a use clause as redundant if the corresponding entity
497 -- is already use-visible. Emit a warning if the use clause comes from
498 -- source and the proper warnings are enabled.
500 procedure Premature_Usage (N : Node_Id);
501 -- Diagnose usage of an entity before it is visible
503 procedure Use_One_Package (P : Entity_Id; N : Node_Id);
504 -- Make visible entities declared in package P potentially use-visible
505 -- in the current context. Also used in the analysis of subunits, when
506 -- re-installing use clauses of parent units. N is the use_clause that
507 -- names P (and possibly other packages).
509 procedure Use_One_Type (Id : Node_Id; Installed : Boolean := False);
510 -- Id is the subtype mark from a use type clause. This procedure makes
511 -- the primitive operators of the type potentially use-visible. The
512 -- boolean flag Installed indicates that the clause is being reinstalled
513 -- after previous analysis, and primitive operations are already chained
514 -- on the Used_Operations list of the clause.
516 procedure Write_Info;
517 -- Write debugging information on entities declared in current scope
519 --------------------------------
520 -- Analyze_Exception_Renaming --
521 --------------------------------
523 -- The language only allows a single identifier, but the tree holds an
524 -- identifier list. The parser has already issued an error message if
525 -- there is more than one element in the list.
527 procedure Analyze_Exception_Renaming (N : Node_Id) is
528 Id : constant Node_Id := Defining_Identifier (N);
529 Nam : constant Node_Id := Name (N);
532 Check_SPARK_Restriction ("exception renaming is not allowed", N);
537 Set_Ekind (Id, E_Exception);
538 Set_Exception_Code (Id, Uint_0);
539 Set_Etype (Id, Standard_Exception_Type);
540 Set_Is_Pure (Id, Is_Pure (Current_Scope));
542 if not Is_Entity_Name (Nam) or else
543 Ekind (Entity (Nam)) /= E_Exception
545 Error_Msg_N ("invalid exception name in renaming", Nam);
547 if Present (Renamed_Object (Entity (Nam))) then
548 Set_Renamed_Object (Id, Renamed_Object (Entity (Nam)));
550 Set_Renamed_Object (Id, Entity (Nam));
553 end Analyze_Exception_Renaming;
555 ---------------------------
556 -- Analyze_Expanded_Name --
557 ---------------------------
559 procedure Analyze_Expanded_Name (N : Node_Id) is
561 -- If the entity pointer is already set, this is an internal node, or a
562 -- node that is analyzed more than once, after a tree modification. In
563 -- such a case there is no resolution to perform, just set the type. For
564 -- completeness, analyze prefix as well.
566 if Present (Entity (N)) then
567 if Is_Type (Entity (N)) then
568 Set_Etype (N, Entity (N));
570 Set_Etype (N, Etype (Entity (N)));
573 Analyze (Prefix (N));
576 Find_Expanded_Name (N);
578 end Analyze_Expanded_Name;
580 ---------------------------------------
581 -- Analyze_Generic_Function_Renaming --
582 ---------------------------------------
584 procedure Analyze_Generic_Function_Renaming (N : Node_Id) is
586 Analyze_Generic_Renaming (N, E_Generic_Function);
587 end Analyze_Generic_Function_Renaming;
589 --------------------------------------
590 -- Analyze_Generic_Package_Renaming --
591 --------------------------------------
593 procedure Analyze_Generic_Package_Renaming (N : Node_Id) is
595 -- Apply the Text_IO Kludge here, since we may be renaming one of the
596 -- subpackages of Text_IO, then join common routine.
598 Text_IO_Kludge (Name (N));
600 Analyze_Generic_Renaming (N, E_Generic_Package);
601 end Analyze_Generic_Package_Renaming;
603 ----------------------------------------
604 -- Analyze_Generic_Procedure_Renaming --
605 ----------------------------------------
607 procedure Analyze_Generic_Procedure_Renaming (N : Node_Id) is
609 Analyze_Generic_Renaming (N, E_Generic_Procedure);
610 end Analyze_Generic_Procedure_Renaming;
612 ------------------------------
613 -- Analyze_Generic_Renaming --
614 ------------------------------
616 procedure Analyze_Generic_Renaming
620 New_P : constant Entity_Id := Defining_Entity (N);
622 Inst : Boolean := False; -- prevent junk warning
625 if Name (N) = Error then
629 Check_SPARK_Restriction ("generic renaming is not allowed", N);
631 Generate_Definition (New_P);
633 if Current_Scope /= Standard_Standard then
634 Set_Is_Pure (New_P, Is_Pure (Current_Scope));
637 if Nkind (Name (N)) = N_Selected_Component then
638 Check_Generic_Child_Unit (Name (N), Inst);
643 if not Is_Entity_Name (Name (N)) then
644 Error_Msg_N ("expect entity name in renaming declaration", Name (N));
647 Old_P := Entity (Name (N));
651 Set_Ekind (New_P, K);
653 if Etype (Old_P) = Any_Type then
656 elsif Ekind (Old_P) /= K then
657 Error_Msg_N ("invalid generic unit name", Name (N));
660 if Present (Renamed_Object (Old_P)) then
661 Set_Renamed_Object (New_P, Renamed_Object (Old_P));
663 Set_Renamed_Object (New_P, Old_P);
666 Set_Is_Pure (New_P, Is_Pure (Old_P));
667 Set_Is_Preelaborated (New_P, Is_Preelaborated (Old_P));
669 Set_Etype (New_P, Etype (Old_P));
670 Set_Has_Completion (New_P);
672 if In_Open_Scopes (Old_P) then
673 Error_Msg_N ("within its scope, generic denotes its instance", N);
676 Check_Library_Unit_Renaming (N, Old_P);
678 end Analyze_Generic_Renaming;
680 -----------------------------
681 -- Analyze_Object_Renaming --
682 -----------------------------
684 procedure Analyze_Object_Renaming (N : Node_Id) is
685 Loc : constant Source_Ptr := Sloc (N);
686 Id : constant Entity_Id := Defining_Identifier (N);
688 Nam : constant Node_Id := Name (N);
692 procedure Check_Constrained_Object;
693 -- If the nominal type is unconstrained but the renamed object is
694 -- constrained, as can happen with renaming an explicit dereference or
695 -- a function return, build a constrained subtype from the object. If
696 -- the renaming is for a formal in an accept statement, the analysis
697 -- has already established its actual subtype. This is only relevant
698 -- if the renamed object is an explicit dereference.
700 function In_Generic_Scope (E : Entity_Id) return Boolean;
701 -- Determine whether entity E is inside a generic cope
703 ------------------------------
704 -- Check_Constrained_Object --
705 ------------------------------
707 procedure Check_Constrained_Object is
711 if Nkind_In (Nam, N_Function_Call, N_Explicit_Dereference)
712 and then Is_Composite_Type (Etype (Nam))
713 and then not Is_Constrained (Etype (Nam))
714 and then not Has_Unknown_Discriminants (Etype (Nam))
715 and then Expander_Active
717 -- If Actual_Subtype is already set, nothing to do
719 if Ekind_In (Id, E_Variable, E_Constant)
720 and then Present (Actual_Subtype (Id))
724 -- A renaming of an unchecked union does not have an
727 elsif Is_Unchecked_Union (Etype (Nam)) then
731 Subt := Make_Temporary (Loc, 'T');
732 Remove_Side_Effects (Nam);
734 Make_Subtype_Declaration (Loc,
735 Defining_Identifier => Subt,
736 Subtype_Indication =>
737 Make_Subtype_From_Expr (Nam, Etype (Nam))));
738 Rewrite (Subtype_Mark (N), New_Occurrence_Of (Subt, Loc));
739 Set_Etype (Nam, Subt);
742 end Check_Constrained_Object;
744 ----------------------
745 -- In_Generic_Scope --
746 ----------------------
748 function In_Generic_Scope (E : Entity_Id) return Boolean is
753 while Present (S) and then S /= Standard_Standard loop
754 if Is_Generic_Unit (S) then
762 end In_Generic_Scope;
764 -- Start of processing for Analyze_Object_Renaming
771 Check_SPARK_Restriction ("object renaming is not allowed", N);
773 Set_Is_Pure (Id, Is_Pure (Current_Scope));
776 -- The renaming of a component that depends on a discriminant requires
777 -- an actual subtype, because in subsequent use of the object Gigi will
778 -- be unable to locate the actual bounds. This explicit step is required
779 -- when the renaming is generated in removing side effects of an
780 -- already-analyzed expression.
782 if Nkind (Nam) = N_Selected_Component
783 and then Analyzed (Nam)
786 Dec := Build_Actual_Subtype_Of_Component (Etype (Nam), Nam);
788 if Present (Dec) then
789 Insert_Action (N, Dec);
790 T := Defining_Identifier (Dec);
794 -- Complete analysis of the subtype mark in any case, for ASIS use
796 if Present (Subtype_Mark (N)) then
797 Find_Type (Subtype_Mark (N));
800 elsif Present (Subtype_Mark (N)) then
801 Find_Type (Subtype_Mark (N));
802 T := Entity (Subtype_Mark (N));
805 -- Reject renamings of conversions unless the type is tagged, or
806 -- the conversion is implicit (which can occur for cases of anonymous
807 -- access types in Ada 2012).
809 if Nkind (Nam) = N_Type_Conversion
810 and then Comes_From_Source (Nam)
811 and then not Is_Tagged_Type (T)
814 ("renaming of conversion only allowed for tagged types", Nam);
819 -- If the renamed object is a function call of a limited type,
820 -- the expansion of the renaming is complicated by the presence
821 -- of various temporaries and subtypes that capture constraints
822 -- of the renamed object. Rewrite node as an object declaration,
823 -- whose expansion is simpler. Given that the object is limited
824 -- there is no copy involved and no performance hit.
826 if Nkind (Nam) = N_Function_Call
827 and then Is_Immutably_Limited_Type (Etype (Nam))
828 and then not Is_Constrained (Etype (Nam))
829 and then Comes_From_Source (N)
832 Set_Ekind (Id, E_Constant);
834 Make_Object_Declaration (Loc,
835 Defining_Identifier => Id,
836 Constant_Present => True,
837 Object_Definition => New_Occurrence_Of (Etype (Nam), Loc),
838 Expression => Relocate_Node (Nam)));
842 -- Ada 2012 (AI05-149): Reject renaming of an anonymous access object
843 -- when renaming declaration has a named access type. The Ada 2012
844 -- coverage rules allow an anonymous access type in the context of
845 -- an expected named general access type, but the renaming rules
846 -- require the types to be the same. (An exception is when the type
847 -- of the renaming is also an anonymous access type, which can only
848 -- happen due to a renaming created by the expander.)
850 if Nkind (Nam) = N_Type_Conversion
851 and then not Comes_From_Source (Nam)
852 and then Ekind (Etype (Expression (Nam))) = E_Anonymous_Access_Type
853 and then Ekind (T) /= E_Anonymous_Access_Type
855 Wrong_Type (Expression (Nam), T); -- Should we give better error???
858 -- Check that a class-wide object is not being renamed as an object
859 -- of a specific type. The test for access types is needed to exclude
860 -- cases where the renamed object is a dynamically tagged access
861 -- result, such as occurs in certain expansions.
863 if Is_Tagged_Type (T) then
864 Check_Dynamically_Tagged_Expression
870 -- Ada 2005 (AI-230/AI-254): Access renaming
872 else pragma Assert (Present (Access_Definition (N)));
873 T := Access_Definition
875 N => Access_Definition (N));
879 -- Ada 2005 AI05-105: if the declaration has an anonymous access
880 -- type, the renamed object must also have an anonymous type, and
881 -- this is a name resolution rule. This was implicit in the last part
882 -- of the first sentence in 8.5.1(3/2), and is made explicit by this
885 if not Is_Overloaded (Nam) then
886 if Ekind (Etype (Nam)) /= Ekind (T) then
888 ("expect anonymous access type in object renaming", N);
895 Typ : Entity_Id := Empty;
896 Seen : Boolean := False;
899 Get_First_Interp (Nam, I, It);
900 while Present (It.Typ) loop
902 -- Renaming is ambiguous if more than one candidate
903 -- interpretation is type-conformant with the context.
905 if Ekind (It.Typ) = Ekind (T) then
906 if Ekind (T) = E_Anonymous_Access_Subprogram_Type
909 (Designated_Type (T), Designated_Type (It.Typ))
915 ("ambiguous expression in renaming", Nam);
918 elsif Ekind (T) = E_Anonymous_Access_Type
920 Covers (Designated_Type (T), Designated_Type (It.Typ))
926 ("ambiguous expression in renaming", Nam);
930 if Covers (T, It.Typ) then
932 Set_Etype (Nam, Typ);
933 Set_Is_Overloaded (Nam, False);
937 Get_Next_Interp (I, It);
944 -- Ada 2005 (AI-231): "In the case where the type is defined by an
945 -- access_definition, the renamed entity shall be of an access-to-
946 -- constant type if and only if the access_definition defines an
947 -- access-to-constant type" ARM 8.5.1(4)
949 if Constant_Present (Access_Definition (N))
950 and then not Is_Access_Constant (Etype (Nam))
952 Error_Msg_N ("(Ada 2005): the renamed object is not "
953 & "access-to-constant (RM 8.5.1(6))", N);
955 elsif not Constant_Present (Access_Definition (N))
956 and then Is_Access_Constant (Etype (Nam))
958 Error_Msg_N ("(Ada 2005): the renamed object is not "
959 & "access-to-variable (RM 8.5.1(6))", N);
962 if Is_Access_Subprogram_Type (Etype (Nam)) then
963 Check_Subtype_Conformant
964 (Designated_Type (T), Designated_Type (Etype (Nam)));
966 elsif not Subtypes_Statically_Match
967 (Designated_Type (T),
968 Available_View (Designated_Type (Etype (Nam))))
971 ("subtype of renamed object does not statically match", N);
975 -- Special processing for renaming function return object. Some errors
976 -- and warnings are produced only for calls that come from source.
978 if Nkind (Nam) = N_Function_Call then
981 -- Usage is illegal in Ada 83
984 if Comes_From_Source (Nam) then
986 ("(Ada 83) cannot rename function return object", Nam);
989 -- In Ada 95, warn for odd case of renaming parameterless function
990 -- call if this is not a limited type (where this is useful).
993 if Warn_On_Object_Renames_Function
994 and then No (Parameter_Associations (Nam))
995 and then not Is_Limited_Type (Etype (Nam))
996 and then Comes_From_Source (Nam)
999 ("?renaming function result object is suspicious", Nam);
1001 ("\?function & will be called only once", Nam,
1002 Entity (Name (Nam)));
1003 Error_Msg_N -- CODEFIX
1004 ("\?suggest using an initialized constant object instead",
1011 Check_Constrained_Object;
1013 -- An object renaming requires an exact match of the type. Class-wide
1014 -- matching is not allowed.
1016 if Is_Class_Wide_Type (T)
1017 and then Base_Type (Etype (Nam)) /= Base_Type (T)
1019 Wrong_Type (Nam, T);
1024 -- Ada 2005 (AI-326): Handle wrong use of incomplete type
1026 if Nkind (Nam) = N_Explicit_Dereference
1027 and then Ekind (Etype (T2)) = E_Incomplete_Type
1029 Error_Msg_NE ("invalid use of incomplete type&", Id, T2);
1032 elsif Ekind (Etype (T)) = E_Incomplete_Type then
1033 Error_Msg_NE ("invalid use of incomplete type&", Id, T);
1037 -- Ada 2005 (AI-327)
1039 if Ada_Version >= Ada_2005
1040 and then Nkind (Nam) = N_Attribute_Reference
1041 and then Attribute_Name (Nam) = Name_Priority
1045 elsif Ada_Version >= Ada_2005
1046 and then Nkind (Nam) in N_Has_Entity
1050 Nam_Ent : Entity_Id;
1053 if Nkind (Nam) = N_Attribute_Reference then
1054 Nam_Ent := Entity (Prefix (Nam));
1056 Nam_Ent := Entity (Nam);
1059 Nam_Decl := Parent (Nam_Ent);
1061 if Has_Null_Exclusion (N)
1062 and then not Has_Null_Exclusion (Nam_Decl)
1064 -- Ada 2005 (AI-423): If the object name denotes a generic
1065 -- formal object of a generic unit G, and the object renaming
1066 -- declaration occurs within the body of G or within the body
1067 -- of a generic unit declared within the declarative region
1068 -- of G, then the declaration of the formal object of G must
1069 -- have a null exclusion or a null-excluding subtype.
1071 if Is_Formal_Object (Nam_Ent)
1072 and then In_Generic_Scope (Id)
1074 if not Can_Never_Be_Null (Etype (Nam_Ent)) then
1076 ("renamed formal does not exclude `NULL` "
1077 & "(RM 8.5.1(4.6/2))", N);
1079 elsif In_Package_Body (Scope (Id)) then
1081 ("formal object does not have a null exclusion"
1082 & "(RM 8.5.1(4.6/2))", N);
1085 -- Ada 2005 (AI-423): Otherwise, the subtype of the object name
1086 -- shall exclude null.
1088 elsif not Can_Never_Be_Null (Etype (Nam_Ent)) then
1090 ("renamed object does not exclude `NULL` "
1091 & "(RM 8.5.1(4.6/2))", N);
1093 -- An instance is illegal if it contains a renaming that
1094 -- excludes null, and the actual does not. The renaming
1095 -- declaration has already indicated that the declaration
1096 -- of the renamed actual in the instance will raise
1097 -- constraint_error.
1099 elsif Nkind (Nam_Decl) = N_Object_Declaration
1100 and then In_Instance
1102 (Corresponding_Generic_Association (Nam_Decl))
1103 and then Nkind (Expression (Nam_Decl))
1104 = N_Raise_Constraint_Error
1107 ("renamed actual does not exclude `NULL` "
1108 & "(RM 8.5.1(4.6/2))", N);
1110 -- Finally, if there is a null exclusion, the subtype mark
1111 -- must not be null-excluding.
1113 elsif No (Access_Definition (N))
1114 and then Can_Never_Be_Null (T)
1117 ("`NOT NULL` not allowed (& already excludes null)",
1122 elsif Can_Never_Be_Null (T)
1123 and then not Can_Never_Be_Null (Etype (Nam_Ent))
1126 ("renamed object does not exclude `NULL` "
1127 & "(RM 8.5.1(4.6/2))", N);
1129 elsif Has_Null_Exclusion (N)
1130 and then No (Access_Definition (N))
1131 and then Can_Never_Be_Null (T)
1134 ("`NOT NULL` not allowed (& already excludes null)", N, T);
1139 Set_Ekind (Id, E_Variable);
1141 -- Initialize the object size and alignment. Note that we used to call
1142 -- Init_Size_Align here, but that's wrong for objects which have only
1143 -- an Esize, not an RM_Size field!
1145 Init_Object_Size_Align (Id);
1147 if T = Any_Type or else Etype (Nam) = Any_Type then
1150 -- Verify that the renamed entity is an object or a function call. It
1151 -- may have been rewritten in several ways.
1153 elsif Is_Object_Reference (Nam) then
1154 if Comes_From_Source (N)
1155 and then Is_Dependent_Component_Of_Mutable_Object (Nam)
1158 ("illegal renaming of discriminant-dependent component", Nam);
1161 -- A static function call may have been folded into a literal
1163 elsif Nkind (Original_Node (Nam)) = N_Function_Call
1165 -- When expansion is disabled, attribute reference is not
1166 -- rewritten as function call. Otherwise it may be rewritten
1167 -- as a conversion, so check original node.
1169 or else (Nkind (Original_Node (Nam)) = N_Attribute_Reference
1170 and then Is_Function_Attribute_Name
1171 (Attribute_Name (Original_Node (Nam))))
1173 -- Weird but legal, equivalent to renaming a function call.
1174 -- Illegal if the literal is the result of constant-folding an
1175 -- attribute reference that is not a function.
1177 or else (Is_Entity_Name (Nam)
1178 and then Ekind (Entity (Nam)) = E_Enumeration_Literal
1180 Nkind (Original_Node (Nam)) /= N_Attribute_Reference)
1182 or else (Nkind (Nam) = N_Type_Conversion
1183 and then Is_Tagged_Type (Entity (Subtype_Mark (Nam))))
1187 elsif Nkind (Nam) = N_Type_Conversion then
1189 ("renaming of conversion only allowed for tagged types", Nam);
1191 -- Ada 2005 (AI-327)
1193 elsif Ada_Version >= Ada_2005
1194 and then Nkind (Nam) = N_Attribute_Reference
1195 and then Attribute_Name (Nam) = Name_Priority
1199 -- Allow internally generated x'Reference expression
1201 elsif Nkind (Nam) = N_Reference then
1205 Error_Msg_N ("expect object name in renaming", Nam);
1210 if not Is_Variable (Nam) then
1211 Set_Ekind (Id, E_Constant);
1212 Set_Never_Set_In_Source (Id, True);
1213 Set_Is_True_Constant (Id, True);
1216 Set_Renamed_Object (Id, Nam);
1217 end Analyze_Object_Renaming;
1219 ------------------------------
1220 -- Analyze_Package_Renaming --
1221 ------------------------------
1223 procedure Analyze_Package_Renaming (N : Node_Id) is
1224 New_P : constant Entity_Id := Defining_Entity (N);
1229 if Name (N) = Error then
1233 -- Apply Text_IO kludge here since we may be renaming a child of Text_IO
1235 Text_IO_Kludge (Name (N));
1237 if Current_Scope /= Standard_Standard then
1238 Set_Is_Pure (New_P, Is_Pure (Current_Scope));
1244 if Is_Entity_Name (Name (N)) then
1245 Old_P := Entity (Name (N));
1250 if Etype (Old_P) = Any_Type then
1251 Error_Msg_N ("expect package name in renaming", Name (N));
1253 elsif Ekind (Old_P) /= E_Package
1254 and then not (Ekind (Old_P) = E_Generic_Package
1255 and then In_Open_Scopes (Old_P))
1257 if Ekind (Old_P) = E_Generic_Package then
1259 ("generic package cannot be renamed as a package", Name (N));
1261 Error_Msg_Sloc := Sloc (Old_P);
1263 ("expect package name in renaming, found& declared#",
1267 -- Set basic attributes to minimize cascaded errors
1269 Set_Ekind (New_P, E_Package);
1270 Set_Etype (New_P, Standard_Void_Type);
1272 -- Here for OK package renaming
1275 -- Entities in the old package are accessible through the renaming
1276 -- entity. The simplest implementation is to have both packages share
1279 Set_Ekind (New_P, E_Package);
1280 Set_Etype (New_P, Standard_Void_Type);
1282 if Present (Renamed_Object (Old_P)) then
1283 Set_Renamed_Object (New_P, Renamed_Object (Old_P));
1285 Set_Renamed_Object (New_P, Old_P);
1288 Set_Has_Completion (New_P);
1290 Set_First_Entity (New_P, First_Entity (Old_P));
1291 Set_Last_Entity (New_P, Last_Entity (Old_P));
1292 Set_First_Private_Entity (New_P, First_Private_Entity (Old_P));
1293 Check_Library_Unit_Renaming (N, Old_P);
1294 Generate_Reference (Old_P, Name (N));
1296 -- If the renaming is in the visible part of a package, then we set
1297 -- Renamed_In_Spec for the renamed package, to prevent giving
1298 -- warnings about no entities referenced. Such a warning would be
1299 -- overenthusiastic, since clients can see entities in the renamed
1300 -- package via the visible package renaming.
1303 Ent : constant Entity_Id := Cunit_Entity (Current_Sem_Unit);
1305 if Ekind (Ent) = E_Package
1306 and then not In_Private_Part (Ent)
1307 and then In_Extended_Main_Source_Unit (N)
1308 and then Ekind (Old_P) = E_Package
1310 Set_Renamed_In_Spec (Old_P);
1314 -- If this is the renaming declaration of a package instantiation
1315 -- within itself, it is the declaration that ends the list of actuals
1316 -- for the instantiation. At this point, the subtypes that rename
1317 -- the actuals are flagged as generic, to avoid spurious ambiguities
1318 -- if the actuals for two distinct formals happen to coincide. If
1319 -- the actual is a private type, the subtype has a private completion
1320 -- that is flagged in the same fashion.
1322 -- Resolution is identical to what is was in the original generic.
1323 -- On exit from the generic instance, these are turned into regular
1324 -- subtypes again, so they are compatible with types in their class.
1326 if not Is_Generic_Instance (Old_P) then
1329 Spec := Specification (Unit_Declaration_Node (Old_P));
1332 if Nkind (Spec) = N_Package_Specification
1333 and then Present (Generic_Parent (Spec))
1334 and then Old_P = Current_Scope
1335 and then Chars (New_P) = Chars (Generic_Parent (Spec))
1341 E := First_Entity (Old_P);
1346 and then Nkind (Parent (E)) = N_Subtype_Declaration
1348 Set_Is_Generic_Actual_Type (E);
1350 if Is_Private_Type (E)
1351 and then Present (Full_View (E))
1353 Set_Is_Generic_Actual_Type (Full_View (E));
1362 end Analyze_Package_Renaming;
1364 -------------------------------
1365 -- Analyze_Renamed_Character --
1366 -------------------------------
1368 procedure Analyze_Renamed_Character
1373 C : constant Node_Id := Name (N);
1376 if Ekind (New_S) = E_Function then
1377 Resolve (C, Etype (New_S));
1380 Check_Frozen_Renaming (N, New_S);
1384 Error_Msg_N ("character literal can only be renamed as function", N);
1386 end Analyze_Renamed_Character;
1388 ---------------------------------
1389 -- Analyze_Renamed_Dereference --
1390 ---------------------------------
1392 procedure Analyze_Renamed_Dereference
1397 Nam : constant Node_Id := Name (N);
1398 P : constant Node_Id := Prefix (Nam);
1404 if not Is_Overloaded (P) then
1405 if Ekind (Etype (Nam)) /= E_Subprogram_Type
1406 or else not Type_Conformant (Etype (Nam), New_S)
1408 Error_Msg_N ("designated type does not match specification", P);
1417 Get_First_Interp (Nam, Ind, It);
1419 while Present (It.Nam) loop
1421 if Ekind (It.Nam) = E_Subprogram_Type
1422 and then Type_Conformant (It.Nam, New_S)
1424 if Typ /= Any_Id then
1425 Error_Msg_N ("ambiguous renaming", P);
1432 Get_Next_Interp (Ind, It);
1435 if Typ = Any_Type then
1436 Error_Msg_N ("designated type does not match specification", P);
1441 Check_Frozen_Renaming (N, New_S);
1445 end Analyze_Renamed_Dereference;
1447 ---------------------------
1448 -- Analyze_Renamed_Entry --
1449 ---------------------------
1451 procedure Analyze_Renamed_Entry
1456 Nam : constant Node_Id := Name (N);
1457 Sel : constant Node_Id := Selector_Name (Nam);
1461 if Entity (Sel) = Any_Id then
1463 -- Selector is undefined on prefix. Error emitted already
1465 Set_Has_Completion (New_S);
1469 -- Otherwise find renamed entity and build body of New_S as a call to it
1471 Old_S := Find_Renamed_Entity (N, Selector_Name (Nam), New_S);
1473 if Old_S = Any_Id then
1474 Error_Msg_N (" no subprogram or entry matches specification", N);
1477 Check_Subtype_Conformant (New_S, Old_S, N);
1478 Generate_Reference (New_S, Defining_Entity (N), 'b');
1479 Style.Check_Identifier (Defining_Entity (N), New_S);
1482 -- Only mode conformance required for a renaming_as_declaration
1484 Check_Mode_Conformant (New_S, Old_S, N);
1487 Inherit_Renamed_Profile (New_S, Old_S);
1489 -- The prefix can be an arbitrary expression that yields a task type,
1490 -- so it must be resolved.
1492 Resolve (Prefix (Nam), Scope (Old_S));
1495 Set_Convention (New_S, Convention (Old_S));
1496 Set_Has_Completion (New_S, Inside_A_Generic);
1499 Check_Frozen_Renaming (N, New_S);
1501 end Analyze_Renamed_Entry;
1503 -----------------------------------
1504 -- Analyze_Renamed_Family_Member --
1505 -----------------------------------
1507 procedure Analyze_Renamed_Family_Member
1512 Nam : constant Node_Id := Name (N);
1513 P : constant Node_Id := Prefix (Nam);
1517 if (Is_Entity_Name (P) and then Ekind (Entity (P)) = E_Entry_Family)
1518 or else (Nkind (P) = N_Selected_Component
1520 Ekind (Entity (Selector_Name (P))) = E_Entry_Family)
1522 if Is_Entity_Name (P) then
1523 Old_S := Entity (P);
1525 Old_S := Entity (Selector_Name (P));
1528 if not Entity_Matches_Spec (Old_S, New_S) then
1529 Error_Msg_N ("entry family does not match specification", N);
1532 Check_Subtype_Conformant (New_S, Old_S, N);
1533 Generate_Reference (New_S, Defining_Entity (N), 'b');
1534 Style.Check_Identifier (Defining_Entity (N), New_S);
1538 Error_Msg_N ("no entry family matches specification", N);
1541 Set_Has_Completion (New_S, Inside_A_Generic);
1544 Check_Frozen_Renaming (N, New_S);
1546 end Analyze_Renamed_Family_Member;
1548 -----------------------------------------
1549 -- Analyze_Renamed_Primitive_Operation --
1550 -----------------------------------------
1552 procedure Analyze_Renamed_Primitive_Operation
1561 Ctyp : Conformance_Type) return Boolean;
1562 -- Verify that the signatures of the renamed entity and the new entity
1563 -- match. The first formal of the renamed entity is skipped because it
1564 -- is the target object in any subsequent call.
1568 Ctyp : Conformance_Type) return Boolean
1574 if Ekind (Subp) /= Ekind (New_S) then
1578 Old_F := Next_Formal (First_Formal (Subp));
1579 New_F := First_Formal (New_S);
1580 while Present (Old_F) and then Present (New_F) loop
1581 if not Conforming_Types (Etype (Old_F), Etype (New_F), Ctyp) then
1585 if Ctyp >= Mode_Conformant
1586 and then Ekind (Old_F) /= Ekind (New_F)
1591 Next_Formal (New_F);
1592 Next_Formal (Old_F);
1599 if not Is_Overloaded (Selector_Name (Name (N))) then
1600 Old_S := Entity (Selector_Name (Name (N)));
1602 if not Conforms (Old_S, Type_Conformant) then
1607 -- Find the operation that matches the given signature
1615 Get_First_Interp (Selector_Name (Name (N)), Ind, It);
1617 while Present (It.Nam) loop
1618 if Conforms (It.Nam, Type_Conformant) then
1622 Get_Next_Interp (Ind, It);
1627 if Old_S = Any_Id then
1628 Error_Msg_N (" no subprogram or entry matches specification", N);
1632 if not Conforms (Old_S, Subtype_Conformant) then
1633 Error_Msg_N ("subtype conformance error in renaming", N);
1636 Generate_Reference (New_S, Defining_Entity (N), 'b');
1637 Style.Check_Identifier (Defining_Entity (N), New_S);
1640 -- Only mode conformance required for a renaming_as_declaration
1642 if not Conforms (Old_S, Mode_Conformant) then
1643 Error_Msg_N ("mode conformance error in renaming", N);
1647 -- Inherit_Renamed_Profile (New_S, Old_S);
1649 -- The prefix can be an arbitrary expression that yields an
1650 -- object, so it must be resolved.
1652 Resolve (Prefix (Name (N)));
1654 end Analyze_Renamed_Primitive_Operation;
1656 ---------------------------------
1657 -- Analyze_Subprogram_Renaming --
1658 ---------------------------------
1660 procedure Analyze_Subprogram_Renaming (N : Node_Id) is
1661 Formal_Spec : constant Node_Id := Corresponding_Formal_Spec (N);
1662 Is_Actual : constant Boolean := Present (Formal_Spec);
1663 Inst_Node : Node_Id := Empty;
1664 Nam : constant Node_Id := Name (N);
1666 Old_S : Entity_Id := Empty;
1667 Rename_Spec : Entity_Id;
1668 Save_AV : constant Ada_Version_Type := Ada_Version;
1669 Save_AV_Exp : constant Ada_Version_Type := Ada_Version_Explicit;
1670 Spec : constant Node_Id := Specification (N);
1672 procedure Check_Null_Exclusion
1675 -- Ada 2005 (AI-423): Given renaming Ren of subprogram Sub, check the
1676 -- following AI rules:
1678 -- If Ren is a renaming of a formal subprogram and one of its
1679 -- parameters has a null exclusion, then the corresponding formal
1680 -- in Sub must also have one. Otherwise the subtype of the Sub's
1681 -- formal parameter must exclude null.
1683 -- If Ren is a renaming of a formal function and its return
1684 -- profile has a null exclusion, then Sub's return profile must
1685 -- have one. Otherwise the subtype of Sub's return profile must
1688 function Original_Subprogram (Subp : Entity_Id) return Entity_Id;
1689 -- Find renamed entity when the declaration is a renaming_as_body and
1690 -- the renamed entity may itself be a renaming_as_body. Used to enforce
1691 -- rule that a renaming_as_body is illegal if the declaration occurs
1692 -- before the subprogram it completes is frozen, and renaming indirectly
1693 -- renames the subprogram itself.(Defect Report 8652/0027).
1695 function Check_Class_Wide_Actual return Entity_Id;
1696 -- AI05-0071: In an instance, if the actual for a formal type FT with
1697 -- unknown discriminants is a class-wide type CT, and the generic has
1698 -- a formal subprogram with a box for a primitive operation of FT,
1699 -- then the corresponding actual subprogram denoted by the default is a
1700 -- class-wide operation whose body is a dispatching call. We replace the
1701 -- generated renaming declaration:
1703 -- procedure P (X : CT) renames P;
1705 -- by a different renaming and a class-wide operation:
1707 -- procedure Pr (X : T) renames P; -- renames primitive operation
1708 -- procedure P (X : CT); -- class-wide operation
1710 -- procedure P (X : CT) is begin Pr (X); end; -- dispatching call
1712 -- This rule only applies if there is no explicit visible class-wide
1713 -- operation at the point of the instantiation.
1715 function Has_Class_Wide_Actual return Boolean;
1716 -- Ada 2012 (AI05-071, AI05-0131): True if N is the renaming for a
1717 -- defaulted formal subprogram when the actual for the controlling
1718 -- formal type is class-wide.
1720 -----------------------------
1721 -- Check_Class_Wide_Actual --
1722 -----------------------------
1724 function Check_Class_Wide_Actual return Entity_Id is
1725 Loc : constant Source_Ptr := Sloc (N);
1728 Formal_Type : Entity_Id;
1729 Actual_Type : Entity_Id;
1734 function Make_Call (Prim_Op : Entity_Id) return Node_Id;
1735 -- Build dispatching call for body of class-wide operation
1737 function Make_Spec return Node_Id;
1738 -- Create subprogram specification for declaration and body of
1739 -- class-wide operation, using signature of renaming declaration.
1745 function Make_Call (Prim_Op : Entity_Id) return Node_Id is
1750 Actuals := New_List;
1751 F := First (Parameter_Specifications (Specification (New_Decl)));
1752 while Present (F) loop
1754 Make_Identifier (Loc, Chars (Defining_Identifier (F))));
1758 if Ekind_In (Prim_Op, E_Function, E_Operator) then
1759 return Make_Simple_Return_Statement (Loc,
1761 Make_Function_Call (Loc,
1762 Name => New_Occurrence_Of (Prim_Op, Loc),
1763 Parameter_Associations => Actuals));
1766 Make_Procedure_Call_Statement (Loc,
1767 Name => New_Occurrence_Of (Prim_Op, Loc),
1768 Parameter_Associations => Actuals);
1776 function Make_Spec return Node_Id is
1777 Param_Specs : constant List_Id := Copy_Parameter_List (New_S);
1780 if Ekind (New_S) = E_Procedure then
1782 Make_Procedure_Specification (Loc,
1783 Defining_Unit_Name =>
1784 Make_Defining_Identifier (Loc,
1785 Chars (Defining_Unit_Name (Spec))),
1786 Parameter_Specifications => Param_Specs);
1789 Make_Function_Specification (Loc,
1790 Defining_Unit_Name =>
1791 Make_Defining_Identifier (Loc,
1792 Chars (Defining_Unit_Name (Spec))),
1793 Parameter_Specifications => Param_Specs,
1794 Result_Definition =>
1795 New_Copy_Tree (Result_Definition (Spec)));
1799 -- Start of processing for Check_Class_Wide_Actual
1803 Formal_Type := Empty;
1804 Actual_Type := Empty;
1806 F := First_Formal (Formal_Spec);
1807 while Present (F) loop
1808 if Has_Unknown_Discriminants (Etype (F))
1809 and then not Is_Class_Wide_Type (Etype (F))
1810 and then Is_Class_Wide_Type (Get_Instance_Of (Etype (F)))
1812 Formal_Type := Etype (F);
1813 Actual_Type := Etype (Get_Instance_Of (Formal_Type));
1820 if Present (Formal_Type) then
1822 -- Create declaration and body for class-wide operation
1825 Make_Subprogram_Declaration (Loc, Specification => Make_Spec);
1828 Make_Subprogram_Body (Loc,
1829 Specification => Make_Spec,
1830 Declarations => No_List,
1831 Handled_Statement_Sequence =>
1832 Make_Handled_Sequence_Of_Statements (Loc, New_List));
1834 -- Modify Spec and create internal name for renaming of primitive
1837 Set_Defining_Unit_Name (Spec, Make_Temporary (Loc, 'R'));
1838 F := First (Parameter_Specifications (Spec));
1839 while Present (F) loop
1840 if Nkind (Parameter_Type (F)) = N_Identifier
1841 and then Is_Class_Wide_Type (Entity (Parameter_Type (F)))
1843 Set_Parameter_Type (F, New_Occurrence_Of (Actual_Type, Loc));
1848 New_S := Analyze_Subprogram_Specification (Spec);
1849 Result := Find_Renamed_Entity (N, Name (N), New_S, Is_Actual);
1852 if Result /= Any_Id then
1853 Insert_Before (N, New_Decl);
1856 -- Add dispatching call to body of class-wide operation
1858 Append (Make_Call (Result),
1859 Statements (Handled_Statement_Sequence (New_Body)));
1861 -- The generated body does not freeze. It is analyzed when the
1862 -- generated operation is frozen. This body is only needed if
1863 -- expansion is enabled.
1865 if Expander_Active then
1866 Append_Freeze_Action (Defining_Entity (New_Decl), New_Body);
1869 Result := Defining_Entity (New_Decl);
1872 -- Return the class-wide operation if one was created
1875 end Check_Class_Wide_Actual;
1877 --------------------------
1878 -- Check_Null_Exclusion --
1879 --------------------------
1881 procedure Check_Null_Exclusion
1885 Ren_Formal : Entity_Id;
1886 Sub_Formal : Entity_Id;
1891 Ren_Formal := First_Formal (Ren);
1892 Sub_Formal := First_Formal (Sub);
1893 while Present (Ren_Formal)
1894 and then Present (Sub_Formal)
1896 if Has_Null_Exclusion (Parent (Ren_Formal))
1898 not (Has_Null_Exclusion (Parent (Sub_Formal))
1899 or else Can_Never_Be_Null (Etype (Sub_Formal)))
1902 ("`NOT NULL` required for parameter &",
1903 Parent (Sub_Formal), Sub_Formal);
1906 Next_Formal (Ren_Formal);
1907 Next_Formal (Sub_Formal);
1910 -- Return profile check
1912 if Nkind (Parent (Ren)) = N_Function_Specification
1913 and then Nkind (Parent (Sub)) = N_Function_Specification
1914 and then Has_Null_Exclusion (Parent (Ren))
1916 not (Has_Null_Exclusion (Parent (Sub))
1917 or else Can_Never_Be_Null (Etype (Sub)))
1920 ("return must specify `NOT NULL`",
1921 Result_Definition (Parent (Sub)));
1923 end Check_Null_Exclusion;
1925 ---------------------------
1926 -- Has_Class_Wide_Actual --
1927 ---------------------------
1929 function Has_Class_Wide_Actual return Boolean is
1935 and then Nkind (Nam) in N_Has_Entity
1936 and then Present (Entity (Nam))
1937 and then Is_Dispatching_Operation (Entity (Nam))
1939 F_Nam := First_Entity (Entity (Nam));
1940 F_Spec := First_Formal (Formal_Spec);
1941 while Present (F_Nam)
1942 and then Present (F_Spec)
1944 if Is_Controlling_Formal (F_Nam)
1945 and then Has_Unknown_Discriminants (Etype (F_Spec))
1946 and then not Is_Class_Wide_Type (Etype (F_Spec))
1947 and then Is_Class_Wide_Type (Get_Instance_Of (Etype (F_Spec)))
1952 Next_Entity (F_Nam);
1953 Next_Formal (F_Spec);
1958 end Has_Class_Wide_Actual;
1960 -------------------------
1961 -- Original_Subprogram --
1962 -------------------------
1964 function Original_Subprogram (Subp : Entity_Id) return Entity_Id is
1965 Orig_Decl : Node_Id;
1966 Orig_Subp : Entity_Id;
1969 -- First case: renamed entity is itself a renaming
1971 if Present (Alias (Subp)) then
1972 return Alias (Subp);
1975 Nkind (Unit_Declaration_Node (Subp)) = N_Subprogram_Declaration
1977 (Corresponding_Body (Unit_Declaration_Node (Subp)))
1979 -- Check if renamed entity is a renaming_as_body
1982 Unit_Declaration_Node
1983 (Corresponding_Body (Unit_Declaration_Node (Subp)));
1985 if Nkind (Orig_Decl) = N_Subprogram_Renaming_Declaration then
1986 Orig_Subp := Entity (Name (Orig_Decl));
1988 if Orig_Subp = Rename_Spec then
1990 -- Circularity detected
1995 return (Original_Subprogram (Orig_Subp));
2003 end Original_Subprogram;
2005 CW_Actual : constant Boolean := Has_Class_Wide_Actual;
2006 -- Ada 2012 (AI05-071, AI05-0131): True if the renaming is for a
2007 -- defaulted formal subprogram when the actual for a related formal
2008 -- type is class-wide.
2010 -- Start of processing for Analyze_Subprogram_Renaming
2013 -- We must test for the attribute renaming case before the Analyze
2014 -- call because otherwise Sem_Attr will complain that the attribute
2015 -- is missing an argument when it is analyzed.
2017 if Nkind (Nam) = N_Attribute_Reference then
2019 -- In the case of an abstract formal subprogram association, rewrite
2020 -- an actual given by a stream attribute as the name of the
2021 -- corresponding stream primitive of the type.
2023 -- In a generic context the stream operations are not generated, and
2024 -- this must be treated as a normal attribute reference, to be
2025 -- expanded in subsequent instantiations.
2027 if Is_Actual and then Is_Abstract_Subprogram (Formal_Spec)
2028 and then Full_Expander_Active
2031 Stream_Prim : Entity_Id;
2032 Prefix_Type : constant Entity_Id := Entity (Prefix (Nam));
2035 -- The class-wide forms of the stream attributes are not
2036 -- primitive dispatching operations (even though they
2037 -- internally dispatch to a stream attribute).
2039 if Is_Class_Wide_Type (Prefix_Type) then
2041 ("attribute must be a primitive dispatching operation",
2046 -- Retrieve the primitive subprogram associated with the
2047 -- attribute. This can only be a stream attribute, since those
2048 -- are the only ones that are dispatching (and the actual for
2049 -- an abstract formal subprogram must be dispatching
2053 case Attribute_Name (Nam) is
2056 Find_Prim_Op (Prefix_Type, TSS_Stream_Input);
2059 Find_Prim_Op (Prefix_Type, TSS_Stream_Output);
2062 Find_Prim_Op (Prefix_Type, TSS_Stream_Read);
2065 Find_Prim_Op (Prefix_Type, TSS_Stream_Write);
2068 ("attribute must be a primitive"
2069 & " dispatching operation", Nam);
2075 -- If no operation was found, and the type is limited,
2076 -- the user should have defined one.
2078 when Program_Error =>
2079 if Is_Limited_Type (Prefix_Type) then
2081 ("stream operation not defined for type&",
2085 -- Otherwise, compiler should have generated default
2092 -- Rewrite the attribute into the name of its corresponding
2093 -- primitive dispatching subprogram. We can then proceed with
2094 -- the usual processing for subprogram renamings.
2097 Prim_Name : constant Node_Id :=
2098 Make_Identifier (Sloc (Nam),
2099 Chars => Chars (Stream_Prim));
2101 Set_Entity (Prim_Name, Stream_Prim);
2102 Rewrite (Nam, Prim_Name);
2107 -- Normal processing for a renaming of an attribute
2110 Attribute_Renaming (N);
2115 -- Check whether this declaration corresponds to the instantiation
2116 -- of a formal subprogram.
2118 -- If this is an instantiation, the corresponding actual is frozen and
2119 -- error messages can be made more precise. If this is a default
2120 -- subprogram, the entity is already established in the generic, and is
2121 -- not retrieved by visibility. If it is a default with a box, the
2122 -- candidate interpretations, if any, have been collected when building
2123 -- the renaming declaration. If overloaded, the proper interpretation is
2124 -- determined in Find_Renamed_Entity. If the entity is an operator,
2125 -- Find_Renamed_Entity applies additional visibility checks.
2128 Inst_Node := Unit_Declaration_Node (Formal_Spec);
2130 -- Check whether the renaming is for a defaulted actual subprogram
2131 -- with a class-wide actual.
2134 New_S := Analyze_Subprogram_Specification (Spec);
2135 Old_S := Check_Class_Wide_Actual;
2137 elsif Is_Entity_Name (Nam)
2138 and then Present (Entity (Nam))
2139 and then not Comes_From_Source (Nam)
2140 and then not Is_Overloaded (Nam)
2142 Old_S := Entity (Nam);
2143 New_S := Analyze_Subprogram_Specification (Spec);
2147 if Ekind (Entity (Nam)) = E_Operator then
2151 if Box_Present (Inst_Node) then
2152 Old_S := Find_Renamed_Entity (N, Name (N), New_S, Is_Actual);
2154 -- If there is an immediately visible homonym of the operator
2155 -- and the declaration has a default, this is worth a warning
2156 -- because the user probably did not intend to get the pre-
2157 -- defined operator, visible in the generic declaration. To
2158 -- find if there is an intended candidate, analyze the renaming
2159 -- again in the current context.
2161 elsif Scope (Old_S) = Standard_Standard
2162 and then Present (Default_Name (Inst_Node))
2165 Decl : constant Node_Id := New_Copy_Tree (N);
2169 Set_Entity (Name (Decl), Empty);
2170 Analyze (Name (Decl));
2172 Find_Renamed_Entity (Decl, Name (Decl), New_S, True);
2175 and then In_Open_Scopes (Scope (Hidden))
2176 and then Is_Immediately_Visible (Hidden)
2177 and then Comes_From_Source (Hidden)
2178 and then Hidden /= Old_S
2180 Error_Msg_Sloc := Sloc (Hidden);
2181 Error_Msg_N ("?default subprogram is resolved " &
2182 "in the generic declaration " &
2183 "(RM 12.6(17))", N);
2184 Error_Msg_NE ("\?and will not use & #", N, Hidden);
2192 New_S := Analyze_Subprogram_Specification (Spec);
2196 -- Renamed entity must be analyzed first, to avoid being hidden by
2197 -- new name (which might be the same in a generic instance).
2201 -- The renaming defines a new overloaded entity, which is analyzed
2202 -- like a subprogram declaration.
2204 New_S := Analyze_Subprogram_Specification (Spec);
2207 if Current_Scope /= Standard_Standard then
2208 Set_Is_Pure (New_S, Is_Pure (Current_Scope));
2211 Rename_Spec := Find_Corresponding_Spec (N);
2213 -- Case of Renaming_As_Body
2215 if Present (Rename_Spec) then
2217 -- Renaming declaration is the completion of the declaration of
2218 -- Rename_Spec. We build an actual body for it at the freezing point.
2220 Set_Corresponding_Spec (N, Rename_Spec);
2222 -- Deal with special case of stream functions of abstract types
2225 if Nkind (Unit_Declaration_Node (Rename_Spec)) =
2226 N_Abstract_Subprogram_Declaration
2228 -- Input stream functions are abstract if the object type is
2229 -- abstract. Similarly, all default stream functions for an
2230 -- interface type are abstract. However, these subprograms may
2231 -- receive explicit declarations in representation clauses, making
2232 -- the attribute subprograms usable as defaults in subsequent
2234 -- In this case we rewrite the declaration to make the subprogram
2235 -- non-abstract. We remove the previous declaration, and insert
2236 -- the new one at the point of the renaming, to prevent premature
2237 -- access to unfrozen types. The new declaration reuses the
2238 -- specification of the previous one, and must not be analyzed.
2241 (Is_Primitive (Entity (Nam))
2243 Is_Abstract_Type (Find_Dispatching_Type (Entity (Nam))));
2245 Old_Decl : constant Node_Id :=
2246 Unit_Declaration_Node (Rename_Spec);
2247 New_Decl : constant Node_Id :=
2248 Make_Subprogram_Declaration (Sloc (N),
2250 Relocate_Node (Specification (Old_Decl)));
2253 Insert_After (N, New_Decl);
2254 Set_Is_Abstract_Subprogram (Rename_Spec, False);
2255 Set_Analyzed (New_Decl);
2259 Set_Corresponding_Body (Unit_Declaration_Node (Rename_Spec), New_S);
2261 if Ada_Version = Ada_83 and then Comes_From_Source (N) then
2262 Error_Msg_N ("(Ada 83) renaming cannot serve as a body", N);
2265 Set_Convention (New_S, Convention (Rename_Spec));
2266 Check_Fully_Conformant (New_S, Rename_Spec);
2267 Set_Public_Status (New_S);
2269 -- The specification does not introduce new formals, but only
2270 -- repeats the formals of the original subprogram declaration.
2271 -- For cross-reference purposes, and for refactoring tools, we
2272 -- treat the formals of the renaming declaration as body formals.
2274 Reference_Body_Formals (Rename_Spec, New_S);
2276 -- Indicate that the entity in the declaration functions like the
2277 -- corresponding body, and is not a new entity. The body will be
2278 -- constructed later at the freeze point, so indicate that the
2279 -- completion has not been seen yet.
2281 Set_Ekind (New_S, E_Subprogram_Body);
2282 New_S := Rename_Spec;
2283 Set_Has_Completion (Rename_Spec, False);
2285 -- Ada 2005: check overriding indicator
2287 if Present (Overridden_Operation (Rename_Spec)) then
2288 if Must_Not_Override (Specification (N)) then
2290 ("subprogram& overrides inherited operation",
2293 Style_Check and then not Must_Override (Specification (N))
2295 Style.Missing_Overriding (N, Rename_Spec);
2298 elsif Must_Override (Specification (N)) then
2299 Error_Msg_NE ("subprogram& is not overriding", N, Rename_Spec);
2302 -- Normal subprogram renaming (not renaming as body)
2305 Generate_Definition (New_S);
2306 New_Overloaded_Entity (New_S);
2308 if Is_Entity_Name (Nam)
2309 and then Is_Intrinsic_Subprogram (Entity (Nam))
2313 Check_Delayed_Subprogram (New_S);
2317 -- There is no need for elaboration checks on the new entity, which may
2318 -- be called before the next freezing point where the body will appear.
2319 -- Elaboration checks refer to the real entity, not the one created by
2320 -- the renaming declaration.
2322 Set_Kill_Elaboration_Checks (New_S, True);
2324 if Etype (Nam) = Any_Type then
2325 Set_Has_Completion (New_S);
2328 elsif Nkind (Nam) = N_Selected_Component then
2330 -- A prefix of the form A.B can designate an entry of task A, a
2331 -- protected operation of protected object A, or finally a primitive
2332 -- operation of object A. In the later case, A is an object of some
2333 -- tagged type, or an access type that denotes one such. To further
2334 -- distinguish these cases, note that the scope of a task entry or
2335 -- protected operation is type of the prefix.
2337 -- The prefix could be an overloaded function call that returns both
2338 -- kinds of operations. This overloading pathology is left to the
2339 -- dedicated reader ???
2342 T : constant Entity_Id := Etype (Prefix (Nam));
2351 Is_Tagged_Type (Designated_Type (T))))
2352 and then Scope (Entity (Selector_Name (Nam))) /= T
2354 Analyze_Renamed_Primitive_Operation
2355 (N, New_S, Present (Rename_Spec));
2359 -- Renamed entity is an entry or protected operation. For those
2360 -- cases an explicit body is built (at the point of freezing of
2361 -- this entity) that contains a call to the renamed entity.
2363 -- This is not allowed for renaming as body if the renamed
2364 -- spec is already frozen (see RM 8.5.4(5) for details).
2366 if Present (Rename_Spec)
2367 and then Is_Frozen (Rename_Spec)
2370 ("renaming-as-body cannot rename entry as subprogram", N);
2372 ("\since & is already frozen (RM 8.5.4(5))",
2375 Analyze_Renamed_Entry (N, New_S, Present (Rename_Spec));
2382 elsif Nkind (Nam) = N_Explicit_Dereference then
2384 -- Renamed entity is designated by access_to_subprogram expression.
2385 -- Must build body to encapsulate call, as in the entry case.
2387 Analyze_Renamed_Dereference (N, New_S, Present (Rename_Spec));
2390 elsif Nkind (Nam) = N_Indexed_Component then
2391 Analyze_Renamed_Family_Member (N, New_S, Present (Rename_Spec));
2394 elsif Nkind (Nam) = N_Character_Literal then
2395 Analyze_Renamed_Character (N, New_S, Present (Rename_Spec));
2398 elsif not Is_Entity_Name (Nam)
2399 or else not Is_Overloadable (Entity (Nam))
2401 Error_Msg_N ("expect valid subprogram name in renaming", N);
2405 -- Find the renamed entity that matches the given specification. Disable
2406 -- Ada_83 because there is no requirement of full conformance between
2407 -- renamed entity and new entity, even though the same circuit is used.
2409 -- This is a bit of a kludge, which introduces a really irregular use of
2410 -- Ada_Version[_Explicit]. Would be nice to find cleaner way to do this
2413 Ada_Version := Ada_Version_Type'Max (Ada_Version, Ada_95);
2414 Ada_Version_Explicit := Ada_Version;
2417 Old_S := Find_Renamed_Entity (N, Name (N), New_S, Is_Actual);
2419 -- The visible operation may be an inherited abstract operation that
2420 -- was overridden in the private part, in which case a call will
2421 -- dispatch to the overriding operation. Use the overriding one in
2422 -- the renaming declaration, to prevent spurious errors below.
2424 if Is_Overloadable (Old_S)
2425 and then Is_Abstract_Subprogram (Old_S)
2426 and then No (DTC_Entity (Old_S))
2427 and then Present (Alias (Old_S))
2428 and then not Is_Abstract_Subprogram (Alias (Old_S))
2429 and then Present (Overridden_Operation (Alias (Old_S)))
2431 Old_S := Alias (Old_S);
2434 -- When the renamed subprogram is overloaded and used as an actual
2435 -- of a generic, its entity is set to the first available homonym.
2436 -- We must first disambiguate the name, then set the proper entity.
2438 if Is_Actual and then Is_Overloaded (Nam) then
2439 Set_Entity (Nam, Old_S);
2443 -- Most common case: subprogram renames subprogram. No body is generated
2444 -- in this case, so we must indicate the declaration is complete as is.
2445 -- and inherit various attributes of the renamed subprogram.
2447 if No (Rename_Spec) then
2448 Set_Has_Completion (New_S);
2449 Set_Is_Imported (New_S, Is_Imported (Entity (Nam)));
2450 Set_Is_Pure (New_S, Is_Pure (Entity (Nam)));
2451 Set_Is_Preelaborated (New_S, Is_Preelaborated (Entity (Nam)));
2453 -- Ada 2005 (AI-423): Check the consistency of null exclusions
2454 -- between a subprogram and its correct renaming.
2456 -- Note: the Any_Id check is a guard that prevents compiler crashes
2457 -- when performing a null exclusion check between a renaming and a
2458 -- renamed subprogram that has been found to be illegal.
2460 if Ada_Version >= Ada_2005
2461 and then Entity (Nam) /= Any_Id
2463 Check_Null_Exclusion
2465 Sub => Entity (Nam));
2468 -- Enforce the Ada 2005 rule that the renamed entity cannot require
2469 -- overriding. The flag Requires_Overriding is set very selectively
2470 -- and misses some other illegal cases. The additional conditions
2471 -- checked below are sufficient but not necessary ???
2473 -- The rule does not apply to the renaming generated for an actual
2474 -- subprogram in an instance.
2479 -- Guard against previous errors, and omit renamings of predefined
2482 elsif not Ekind_In (Old_S, E_Function, E_Procedure) then
2485 elsif Requires_Overriding (Old_S)
2487 (Is_Abstract_Subprogram (Old_S)
2488 and then Present (Find_Dispatching_Type (Old_S))
2490 not Is_Abstract_Type (Find_Dispatching_Type (Old_S)))
2493 ("renamed entity cannot be "
2494 & "subprogram that requires overriding (RM 8.5.4 (5.1))", N);
2498 if Old_S /= Any_Id then
2499 if Is_Actual and then From_Default (N) then
2501 -- This is an implicit reference to the default actual
2503 Generate_Reference (Old_S, Nam, Typ => 'i', Force => True);
2506 Generate_Reference (Old_S, Nam);
2509 -- For a renaming-as-body, require subtype conformance, but if the
2510 -- declaration being completed has not been frozen, then inherit the
2511 -- convention of the renamed subprogram prior to checking conformance
2512 -- (unless the renaming has an explicit convention established; the
2513 -- rule stated in the RM doesn't seem to address this ???).
2515 if Present (Rename_Spec) then
2516 Generate_Reference (Rename_Spec, Defining_Entity (Spec), 'b');
2517 Style.Check_Identifier (Defining_Entity (Spec), Rename_Spec);
2519 if not Is_Frozen (Rename_Spec) then
2520 if not Has_Convention_Pragma (Rename_Spec) then
2521 Set_Convention (New_S, Convention (Old_S));
2524 if Ekind (Old_S) /= E_Operator then
2525 Check_Mode_Conformant (New_S, Old_S, Spec);
2528 if Original_Subprogram (Old_S) = Rename_Spec then
2529 Error_Msg_N ("unfrozen subprogram cannot rename itself ", N);
2532 Check_Subtype_Conformant (New_S, Old_S, Spec);
2535 Check_Frozen_Renaming (N, Rename_Spec);
2537 -- Check explicitly that renamed entity is not intrinsic, because
2538 -- in a generic the renamed body is not built. In this case,
2539 -- the renaming_as_body is a completion.
2541 if Inside_A_Generic then
2542 if Is_Frozen (Rename_Spec)
2543 and then Is_Intrinsic_Subprogram (Old_S)
2546 ("subprogram in renaming_as_body cannot be intrinsic",
2550 Set_Has_Completion (Rename_Spec);
2553 elsif Ekind (Old_S) /= E_Operator then
2555 -- If this a defaulted subprogram for a class-wide actual there is
2556 -- no check for mode conformance, given that the signatures don't
2557 -- match (the source mentions T but the actual mentions T'Class).
2562 Check_Mode_Conformant (New_S, Old_S);
2566 and then Error_Posted (New_S)
2568 Error_Msg_NE ("invalid actual subprogram: & #!", N, Old_S);
2572 if No (Rename_Spec) then
2574 -- The parameter profile of the new entity is that of the renamed
2575 -- entity: the subtypes given in the specification are irrelevant.
2577 Inherit_Renamed_Profile (New_S, Old_S);
2579 -- A call to the subprogram is transformed into a call to the
2580 -- renamed entity. This is transitive if the renamed entity is
2581 -- itself a renaming.
2583 if Present (Alias (Old_S)) then
2584 Set_Alias (New_S, Alias (Old_S));
2586 Set_Alias (New_S, Old_S);
2589 -- Note that we do not set Is_Intrinsic_Subprogram if we have a
2590 -- renaming as body, since the entity in this case is not an
2591 -- intrinsic (it calls an intrinsic, but we have a real body for
2592 -- this call, and it is in this body that the required intrinsic
2593 -- processing will take place).
2595 -- Also, if this is a renaming of inequality, the renamed operator
2596 -- is intrinsic, but what matters is the corresponding equality
2597 -- operator, which may be user-defined.
2599 Set_Is_Intrinsic_Subprogram
2601 Is_Intrinsic_Subprogram (Old_S)
2603 (Chars (Old_S) /= Name_Op_Ne
2604 or else Ekind (Old_S) = E_Operator
2606 Is_Intrinsic_Subprogram
2607 (Corresponding_Equality (Old_S))));
2609 if Ekind (Alias (New_S)) = E_Operator then
2610 Set_Has_Delayed_Freeze (New_S, False);
2613 -- If the renaming corresponds to an association for an abstract
2614 -- formal subprogram, then various attributes must be set to
2615 -- indicate that the renaming is an abstract dispatching operation
2616 -- with a controlling type.
2618 if Is_Actual and then Is_Abstract_Subprogram (Formal_Spec) then
2620 -- Mark the renaming as abstract here, so Find_Dispatching_Type
2621 -- see it as corresponding to a generic association for a
2622 -- formal abstract subprogram
2624 Set_Is_Abstract_Subprogram (New_S);
2627 New_S_Ctrl_Type : constant Entity_Id :=
2628 Find_Dispatching_Type (New_S);
2629 Old_S_Ctrl_Type : constant Entity_Id :=
2630 Find_Dispatching_Type (Old_S);
2633 if Old_S_Ctrl_Type /= New_S_Ctrl_Type then
2635 ("actual must be dispatching subprogram for type&",
2636 Nam, New_S_Ctrl_Type);
2639 Set_Is_Dispatching_Operation (New_S);
2640 Check_Controlling_Formals (New_S_Ctrl_Type, New_S);
2642 -- If the actual in the formal subprogram is itself a
2643 -- formal abstract subprogram association, there's no
2644 -- dispatch table component or position to inherit.
2646 if Present (DTC_Entity (Old_S)) then
2647 Set_DTC_Entity (New_S, DTC_Entity (Old_S));
2648 Set_DT_Position (New_S, DT_Position (Old_S));
2656 and then (Old_S = New_S
2657 or else (Nkind (Nam) /= N_Expanded_Name
2658 and then Chars (Old_S) = Chars (New_S)))
2660 Error_Msg_N ("subprogram cannot rename itself", N);
2663 Set_Convention (New_S, Convention (Old_S));
2665 if Is_Abstract_Subprogram (Old_S) then
2666 if Present (Rename_Spec) then
2668 ("a renaming-as-body cannot rename an abstract subprogram",
2670 Set_Has_Completion (Rename_Spec);
2672 Set_Is_Abstract_Subprogram (New_S);
2676 Check_Library_Unit_Renaming (N, Old_S);
2678 -- Pathological case: procedure renames entry in the scope of its
2679 -- task. Entry is given by simple name, but body must be built for
2680 -- procedure. Of course if called it will deadlock.
2682 if Ekind (Old_S) = E_Entry then
2683 Set_Has_Completion (New_S, False);
2684 Set_Alias (New_S, Empty);
2688 Freeze_Before (N, Old_S);
2689 Set_Has_Delayed_Freeze (New_S, False);
2690 Freeze_Before (N, New_S);
2692 -- An abstract subprogram is only allowed as an actual in the case
2693 -- where the formal subprogram is also abstract.
2695 if (Ekind (Old_S) = E_Procedure or else Ekind (Old_S) = E_Function)
2696 and then Is_Abstract_Subprogram (Old_S)
2697 and then not Is_Abstract_Subprogram (Formal_Spec)
2700 ("abstract subprogram not allowed as generic actual", Nam);
2705 -- A common error is to assume that implicit operators for types are
2706 -- defined in Standard, or in the scope of a subtype. In those cases
2707 -- where the renamed entity is given with an expanded name, it is
2708 -- worth mentioning that operators for the type are not declared in
2709 -- the scope given by the prefix.
2711 if Nkind (Nam) = N_Expanded_Name
2712 and then Nkind (Selector_Name (Nam)) = N_Operator_Symbol
2713 and then Scope (Entity (Nam)) = Standard_Standard
2716 T : constant Entity_Id :=
2717 Base_Type (Etype (First_Formal (New_S)));
2719 Error_Msg_Node_2 := Prefix (Nam);
2721 ("operator for type& is not declared in&", Prefix (Nam), T);
2726 ("no visible subprogram matches the specification for&",
2730 if Present (Candidate_Renaming) then
2737 F1 := First_Formal (Candidate_Renaming);
2738 F2 := First_Formal (New_S);
2739 T1 := First_Subtype (Etype (F1));
2741 while Present (F1) and then Present (F2) loop
2746 if Present (F1) and then Present (Default_Value (F1)) then
2747 if Present (Next_Formal (F1)) then
2749 ("\missing specification for &" &
2750 " and other formals with defaults", Spec, F1);
2753 ("\missing specification for &", Spec, F1);
2757 if Nkind (Nam) = N_Operator_Symbol
2758 and then From_Default (N)
2760 Error_Msg_Node_2 := T1;
2762 ("default & on & is not directly visible",
2769 -- Ada 2005 AI 404: if the new subprogram is dispatching, verify that
2770 -- controlling access parameters are known non-null for the renamed
2771 -- subprogram. Test also applies to a subprogram instantiation that
2772 -- is dispatching. Test is skipped if some previous error was detected
2773 -- that set Old_S to Any_Id.
2775 if Ada_Version >= Ada_2005
2776 and then Old_S /= Any_Id
2777 and then not Is_Dispatching_Operation (Old_S)
2778 and then Is_Dispatching_Operation (New_S)
2785 Old_F := First_Formal (Old_S);
2786 New_F := First_Formal (New_S);
2787 while Present (Old_F) loop
2788 if Ekind (Etype (Old_F)) = E_Anonymous_Access_Type
2789 and then Is_Controlling_Formal (New_F)
2790 and then not Can_Never_Be_Null (Old_F)
2792 Error_Msg_N ("access parameter is controlling,", New_F);
2794 ("\corresponding parameter of& "
2795 & "must be explicitly null excluding", New_F, Old_S);
2798 Next_Formal (Old_F);
2799 Next_Formal (New_F);
2804 -- A useful warning, suggested by Ada Bug Finder (Ada-Europe 2005)
2805 -- is to warn if an operator is being renamed as a different operator.
2806 -- If the operator is predefined, examine the kind of the entity, not
2807 -- the abbreviated declaration in Standard.
2809 if Comes_From_Source (N)
2810 and then Present (Old_S)
2812 (Nkind (Old_S) = N_Defining_Operator_Symbol
2813 or else Ekind (Old_S) = E_Operator)
2814 and then Nkind (New_S) = N_Defining_Operator_Symbol
2815 and then Chars (Old_S) /= Chars (New_S)
2818 ("?& is being renamed as a different operator", N, Old_S);
2821 -- Check for renaming of obsolescent subprogram
2823 Check_Obsolescent_2005_Entity (Entity (Nam), Nam);
2825 -- Another warning or some utility: if the new subprogram as the same
2826 -- name as the old one, the old one is not hidden by an outer homograph,
2827 -- the new one is not a public symbol, and the old one is otherwise
2828 -- directly visible, the renaming is superfluous.
2830 if Chars (Old_S) = Chars (New_S)
2831 and then Comes_From_Source (N)
2832 and then Scope (Old_S) /= Standard_Standard
2833 and then Warn_On_Redundant_Constructs
2835 (Is_Immediately_Visible (Old_S)
2836 or else Is_Potentially_Use_Visible (Old_S))
2837 and then Is_Overloadable (Current_Scope)
2838 and then Chars (Current_Scope) /= Chars (Old_S)
2841 ("?redundant renaming, entity is directly visible", Name (N));
2844 Ada_Version := Save_AV;
2845 Ada_Version_Explicit := Save_AV_Exp;
2846 end Analyze_Subprogram_Renaming;
2848 -------------------------
2849 -- Analyze_Use_Package --
2850 -------------------------
2852 -- Resolve the package names in the use clause, and make all the visible
2853 -- entities defined in the package potentially use-visible. If the package
2854 -- is already in use from a previous use clause, its visible entities are
2855 -- already use-visible. In that case, mark the occurrence as a redundant
2856 -- use. If the package is an open scope, i.e. if the use clause occurs
2857 -- within the package itself, ignore it.
2859 procedure Analyze_Use_Package (N : Node_Id) is
2860 Pack_Name : Node_Id;
2863 -- Start of processing for Analyze_Use_Package
2866 Check_SPARK_Restriction ("use clause is not allowed", N);
2868 Set_Hidden_By_Use_Clause (N, No_Elist);
2870 -- Use clause not allowed in a spec of a predefined package declaration
2871 -- except that packages whose file name starts a-n are OK (these are
2872 -- children of Ada.Numerics, which are never loaded by Rtsfind).
2874 if Is_Predefined_File_Name (Unit_File_Name (Current_Sem_Unit))
2875 and then Name_Buffer (1 .. 3) /= "a-n"
2877 Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Declaration
2879 Error_Msg_N ("use clause not allowed in predefined spec", N);
2882 -- Chain clause to list of use clauses in current scope
2884 if Nkind (Parent (N)) /= N_Compilation_Unit then
2885 Chain_Use_Clause (N);
2888 -- Loop through package names to identify referenced packages
2890 Pack_Name := First (Names (N));
2891 while Present (Pack_Name) loop
2892 Analyze (Pack_Name);
2894 if Nkind (Parent (N)) = N_Compilation_Unit
2895 and then Nkind (Pack_Name) = N_Expanded_Name
2901 Pref := Prefix (Pack_Name);
2902 while Nkind (Pref) = N_Expanded_Name loop
2903 Pref := Prefix (Pref);
2906 if Entity (Pref) = Standard_Standard then
2908 ("predefined package Standard cannot appear"
2909 & " in a context clause", Pref);
2917 -- Loop through package names to mark all entities as potentially
2920 Pack_Name := First (Names (N));
2921 while Present (Pack_Name) loop
2922 if Is_Entity_Name (Pack_Name) then
2923 Pack := Entity (Pack_Name);
2925 if Ekind (Pack) /= E_Package
2926 and then Etype (Pack) /= Any_Type
2928 if Ekind (Pack) = E_Generic_Package then
2929 Error_Msg_N -- CODEFIX
2930 ("a generic package is not allowed in a use clause",
2933 Error_Msg_N ("& is not a usable package", Pack_Name);
2937 if Nkind (Parent (N)) = N_Compilation_Unit then
2938 Check_In_Previous_With_Clause (N, Pack_Name);
2941 if Applicable_Use (Pack_Name) then
2942 Use_One_Package (Pack, N);
2946 -- Report error because name denotes something other than a package
2949 Error_Msg_N ("& is not a package", Pack_Name);
2954 end Analyze_Use_Package;
2956 ----------------------
2957 -- Analyze_Use_Type --
2958 ----------------------
2960 procedure Analyze_Use_Type (N : Node_Id) is
2965 Set_Hidden_By_Use_Clause (N, No_Elist);
2967 -- Chain clause to list of use clauses in current scope
2969 if Nkind (Parent (N)) /= N_Compilation_Unit then
2970 Chain_Use_Clause (N);
2973 -- If the Used_Operations list is already initialized, the clause has
2974 -- been analyzed previously, and it is begin reinstalled, for example
2975 -- when the clause appears in a package spec and we are compiling the
2976 -- corresponding package body. In that case, make the entities on the
2977 -- existing list use_visible, and mark the corresponding types In_Use.
2979 if Present (Used_Operations (N)) then
2985 Mark := First (Subtype_Marks (N));
2986 while Present (Mark) loop
2987 Use_One_Type (Mark, Installed => True);
2991 Elmt := First_Elmt (Used_Operations (N));
2992 while Present (Elmt) loop
2993 Set_Is_Potentially_Use_Visible (Node (Elmt));
3001 -- Otherwise, create new list and attach to it the operations that
3002 -- are made use-visible by the clause.
3004 Set_Used_Operations (N, New_Elmt_List);
3005 Id := First (Subtype_Marks (N));
3006 while Present (Id) loop
3010 if E /= Any_Type then
3013 if Nkind (Parent (N)) = N_Compilation_Unit then
3014 if Nkind (Id) = N_Identifier then
3015 Error_Msg_N ("type is not directly visible", Id);
3017 elsif Is_Child_Unit (Scope (E))
3018 and then Scope (E) /= System_Aux_Id
3020 Check_In_Previous_With_Clause (N, Prefix (Id));
3025 -- If the use_type_clause appears in a compilation unit context,
3026 -- check whether it comes from a unit that may appear in a
3027 -- limited_with_clause, for a better error message.
3029 if Nkind (Parent (N)) = N_Compilation_Unit
3030 and then Nkind (Id) /= N_Identifier
3036 function Mentioned (Nam : Node_Id) return Boolean;
3037 -- Check whether the prefix of expanded name for the type
3038 -- appears in the prefix of some limited_with_clause.
3044 function Mentioned (Nam : Node_Id) return Boolean is
3046 return Nkind (Name (Item)) = N_Selected_Component
3048 Chars (Prefix (Name (Item))) = Chars (Nam);
3052 Pref := Prefix (Id);
3053 Item := First (Context_Items (Parent (N)));
3055 while Present (Item) and then Item /= N loop
3056 if Nkind (Item) = N_With_Clause
3057 and then Limited_Present (Item)
3058 and then Mentioned (Pref)
3061 (Get_Msg_Id, "premature usage of incomplete type");
3072 end Analyze_Use_Type;
3074 --------------------
3075 -- Applicable_Use --
3076 --------------------
3078 function Applicable_Use (Pack_Name : Node_Id) return Boolean is
3079 Pack : constant Entity_Id := Entity (Pack_Name);
3082 if In_Open_Scopes (Pack) then
3083 if Warn_On_Redundant_Constructs
3084 and then Pack = Current_Scope
3086 Error_Msg_NE -- CODEFIX
3087 ("& is already use-visible within itself?", Pack_Name, Pack);
3092 elsif In_Use (Pack) then
3093 Note_Redundant_Use (Pack_Name);
3096 elsif Present (Renamed_Object (Pack))
3097 and then In_Use (Renamed_Object (Pack))
3099 Note_Redundant_Use (Pack_Name);
3107 ------------------------
3108 -- Attribute_Renaming --
3109 ------------------------
3111 procedure Attribute_Renaming (N : Node_Id) is
3112 Loc : constant Source_Ptr := Sloc (N);
3113 Nam : constant Node_Id := Name (N);
3114 Spec : constant Node_Id := Specification (N);
3115 New_S : constant Entity_Id := Defining_Unit_Name (Spec);
3116 Aname : constant Name_Id := Attribute_Name (Nam);
3118 Form_Num : Nat := 0;
3119 Expr_List : List_Id := No_List;
3121 Attr_Node : Node_Id;
3122 Body_Node : Node_Id;
3123 Param_Spec : Node_Id;
3126 Generate_Definition (New_S);
3128 -- This procedure is called in the context of subprogram renaming, and
3129 -- thus the attribute must be one that is a subprogram. All of those
3130 -- have at least one formal parameter, with the singular exception of
3131 -- AST_Entry (which is a real oddity, it is odd that this can be renamed
3134 if not Is_Non_Empty_List (Parameter_Specifications (Spec)) then
3135 if Aname /= Name_AST_Entry then
3137 ("subprogram renaming an attribute must have formals", N);
3142 Param_Spec := First (Parameter_Specifications (Spec));
3143 while Present (Param_Spec) loop
3144 Form_Num := Form_Num + 1;
3146 if Nkind (Parameter_Type (Param_Spec)) /= N_Access_Definition then
3147 Find_Type (Parameter_Type (Param_Spec));
3149 -- The profile of the new entity denotes the base type (s) of
3150 -- the types given in the specification. For access parameters
3151 -- there are no subtypes involved.
3153 Rewrite (Parameter_Type (Param_Spec),
3155 (Base_Type (Entity (Parameter_Type (Param_Spec))), Loc));
3158 if No (Expr_List) then
3159 Expr_List := New_List;
3162 Append_To (Expr_List,
3163 Make_Identifier (Loc,
3164 Chars => Chars (Defining_Identifier (Param_Spec))));
3166 -- The expressions in the attribute reference are not freeze
3167 -- points. Neither is the attribute as a whole, see below.
3169 Set_Must_Not_Freeze (Last (Expr_List));
3174 -- Immediate error if too many formals. Other mismatches in number or
3175 -- types of parameters are detected when we analyze the body of the
3176 -- subprogram that we construct.
3178 if Form_Num > 2 then
3179 Error_Msg_N ("too many formals for attribute", N);
3181 -- Error if the attribute reference has expressions that look like
3182 -- formal parameters.
3184 elsif Present (Expressions (Nam)) then
3185 Error_Msg_N ("illegal expressions in attribute reference", Nam);
3188 Aname = Name_Compose or else
3189 Aname = Name_Exponent or else
3190 Aname = Name_Leading_Part or else
3191 Aname = Name_Pos or else
3192 Aname = Name_Round or else
3193 Aname = Name_Scaling or else
3196 if Nkind (N) = N_Subprogram_Renaming_Declaration
3197 and then Present (Corresponding_Formal_Spec (N))
3200 ("generic actual cannot be attribute involving universal type",
3204 ("attribute involving a universal type cannot be renamed",
3209 -- AST_Entry is an odd case. It doesn't really make much sense to allow
3210 -- it to be renamed, but that's the DEC rule, so we have to do it right.
3211 -- The point is that the AST_Entry call should be made now, and what the
3212 -- function will return is the returned value.
3214 -- Note that there is no Expr_List in this case anyway
3216 if Aname = Name_AST_Entry then
3218 Ent : constant Entity_Id := Make_Temporary (Loc, 'R', Nam);
3223 Make_Object_Declaration (Loc,
3224 Defining_Identifier => Ent,
3225 Object_Definition =>
3226 New_Occurrence_Of (RTE (RE_AST_Handler), Loc),
3228 Constant_Present => True);
3230 Set_Assignment_OK (Decl, True);
3231 Insert_Action (N, Decl);
3232 Attr_Node := Make_Identifier (Loc, Chars (Ent));
3235 -- For all other attributes, we rewrite the attribute node to have
3236 -- a list of expressions corresponding to the subprogram formals.
3237 -- A renaming declaration is not a freeze point, and the analysis of
3238 -- the attribute reference should not freeze the type of the prefix.
3242 Make_Attribute_Reference (Loc,
3243 Prefix => Prefix (Nam),
3244 Attribute_Name => Aname,
3245 Expressions => Expr_List);
3247 Set_Must_Not_Freeze (Attr_Node);
3248 Set_Must_Not_Freeze (Prefix (Nam));
3251 -- Case of renaming a function
3253 if Nkind (Spec) = N_Function_Specification then
3254 if Is_Procedure_Attribute_Name (Aname) then
3255 Error_Msg_N ("attribute can only be renamed as procedure", Nam);
3259 Find_Type (Result_Definition (Spec));
3260 Rewrite (Result_Definition (Spec),
3262 Base_Type (Entity (Result_Definition (Spec))), Loc));
3265 Make_Subprogram_Body (Loc,
3266 Specification => Spec,
3267 Declarations => New_List,
3268 Handled_Statement_Sequence =>
3269 Make_Handled_Sequence_Of_Statements (Loc,
3270 Statements => New_List (
3271 Make_Simple_Return_Statement (Loc,
3272 Expression => Attr_Node))));
3274 -- Case of renaming a procedure
3277 if not Is_Procedure_Attribute_Name (Aname) then
3278 Error_Msg_N ("attribute can only be renamed as function", Nam);
3283 Make_Subprogram_Body (Loc,
3284 Specification => Spec,
3285 Declarations => New_List,
3286 Handled_Statement_Sequence =>
3287 Make_Handled_Sequence_Of_Statements (Loc,
3288 Statements => New_List (Attr_Node)));
3291 -- In case of tagged types we add the body of the generated function to
3292 -- the freezing actions of the type (because in the general case such
3293 -- type is still not frozen). We exclude from this processing generic
3294 -- formal subprograms found in instantiations and AST_Entry renamings.
3296 -- We must exclude VM targets and restricted run-time libraries because
3297 -- entity AST_Handler is defined in package System.Aux_Dec which is not
3298 -- available in those platforms. Note that we cannot use the function
3299 -- Restricted_Profile (instead of Configurable_Run_Time_Mode) because
3300 -- the ZFP run-time library is not defined as a profile, and we do not
3301 -- want to deal with AST_Handler in ZFP mode.
3303 if VM_Target = No_VM
3304 and then not Configurable_Run_Time_Mode
3305 and then not Present (Corresponding_Formal_Spec (N))
3306 and then Etype (Nam) /= RTE (RE_AST_Handler)
3309 P : constant Entity_Id := Prefix (Nam);
3314 if Is_Tagged_Type (Etype (P)) then
3315 Ensure_Freeze_Node (Etype (P));
3316 Append_Freeze_Action (Etype (P), Body_Node);
3318 Rewrite (N, Body_Node);
3320 Set_Etype (New_S, Base_Type (Etype (New_S)));
3324 -- Generic formal subprograms or AST_Handler renaming
3327 Rewrite (N, Body_Node);
3329 Set_Etype (New_S, Base_Type (Etype (New_S)));
3332 if Is_Compilation_Unit (New_S) then
3334 ("a library unit can only rename another library unit", N);
3337 -- We suppress elaboration warnings for the resulting entity, since
3338 -- clearly they are not needed, and more particularly, in the case
3339 -- of a generic formal subprogram, the resulting entity can appear
3340 -- after the instantiation itself, and thus look like a bogus case
3341 -- of access before elaboration.
3343 Set_Suppress_Elaboration_Warnings (New_S);
3345 end Attribute_Renaming;
3347 ----------------------
3348 -- Chain_Use_Clause --
3349 ----------------------
3351 procedure Chain_Use_Clause (N : Node_Id) is
3353 Level : Int := Scope_Stack.Last;
3356 if not Is_Compilation_Unit (Current_Scope)
3357 or else not Is_Child_Unit (Current_Scope)
3359 null; -- Common case
3361 elsif Defining_Entity (Parent (N)) = Current_Scope then
3362 null; -- Common case for compilation unit
3365 -- If declaration appears in some other scope, it must be in some
3366 -- parent unit when compiling a child.
3368 Pack := Defining_Entity (Parent (N));
3369 if not In_Open_Scopes (Pack) then
3370 null; -- default as well
3373 -- Find entry for parent unit in scope stack
3375 while Scope_Stack.Table (Level).Entity /= Pack loop
3381 Set_Next_Use_Clause (N,
3382 Scope_Stack.Table (Level).First_Use_Clause);
3383 Scope_Stack.Table (Level).First_Use_Clause := N;
3384 end Chain_Use_Clause;
3386 ---------------------------
3387 -- Check_Frozen_Renaming --
3388 ---------------------------
3390 procedure Check_Frozen_Renaming (N : Node_Id; Subp : Entity_Id) is
3396 and then not Has_Completion (Subp)
3400 (Parent (Declaration_Node (Subp)), Defining_Entity (N));
3402 if Is_Entity_Name (Name (N)) then
3403 Old_S := Entity (Name (N));
3405 if not Is_Frozen (Old_S)
3406 and then Operating_Mode /= Check_Semantics
3408 Append_Freeze_Action (Old_S, B_Node);
3410 Insert_After (N, B_Node);
3414 if Is_Intrinsic_Subprogram (Old_S)
3415 and then not In_Instance
3418 ("subprogram used in renaming_as_body cannot be intrinsic",
3423 Insert_After (N, B_Node);
3427 end Check_Frozen_Renaming;
3429 -------------------------------
3430 -- Set_Entity_Or_Discriminal --
3431 -------------------------------
3433 procedure Set_Entity_Or_Discriminal (N : Node_Id; E : Entity_Id) is
3437 -- If the entity is not a discriminant, or else expansion is disabled,
3438 -- simply set the entity.
3440 if not In_Spec_Expression
3441 or else Ekind (E) /= E_Discriminant
3442 or else Inside_A_Generic
3444 Set_Entity_With_Style_Check (N, E);
3446 -- The replacement of a discriminant by the corresponding discriminal
3447 -- is not done for a task discriminant that appears in a default
3448 -- expression of an entry parameter. See Exp_Ch2.Expand_Discriminant
3449 -- for details on their handling.
3451 elsif Is_Concurrent_Type (Scope (E)) then
3455 and then not Nkind_In (P, N_Parameter_Specification,
3456 N_Component_Declaration)
3462 and then Nkind (P) = N_Parameter_Specification
3467 Set_Entity (N, Discriminal (E));
3470 -- Otherwise, this is a discriminant in a context in which
3471 -- it is a reference to the corresponding parameter of the
3472 -- init proc for the enclosing type.
3475 Set_Entity (N, Discriminal (E));
3477 end Set_Entity_Or_Discriminal;
3479 -----------------------------------
3480 -- Check_In_Previous_With_Clause --
3481 -----------------------------------
3483 procedure Check_In_Previous_With_Clause
3487 Pack : constant Entity_Id := Entity (Original_Node (Nam));
3492 Item := First (Context_Items (Parent (N)));
3494 while Present (Item)
3497 if Nkind (Item) = N_With_Clause
3499 -- Protect the frontend against previous critical errors
3501 and then Nkind (Name (Item)) /= N_Selected_Component
3502 and then Entity (Name (Item)) = Pack
3506 -- Find root library unit in with_clause
3508 while Nkind (Par) = N_Expanded_Name loop
3509 Par := Prefix (Par);
3512 if Is_Child_Unit (Entity (Original_Node (Par))) then
3513 Error_Msg_NE ("& is not directly visible", Par, Entity (Par));
3522 -- On exit, package is not mentioned in a previous with_clause.
3523 -- Check if its prefix is.
3525 if Nkind (Nam) = N_Expanded_Name then
3526 Check_In_Previous_With_Clause (N, Prefix (Nam));
3528 elsif Pack /= Any_Id then
3529 Error_Msg_NE ("& is not visible", Nam, Pack);
3531 end Check_In_Previous_With_Clause;
3533 ---------------------------------
3534 -- Check_Library_Unit_Renaming --
3535 ---------------------------------
3537 procedure Check_Library_Unit_Renaming (N : Node_Id; Old_E : Entity_Id) is
3541 if Nkind (Parent (N)) /= N_Compilation_Unit then
3544 -- Check for library unit. Note that we used to check for the scope
3545 -- being Standard here, but that was wrong for Standard itself.
3547 elsif not Is_Compilation_Unit (Old_E)
3548 and then not Is_Child_Unit (Old_E)
3550 Error_Msg_N ("renamed unit must be a library unit", Name (N));
3552 -- Entities defined in Standard (operators and boolean literals) cannot
3553 -- be renamed as library units.
3555 elsif Scope (Old_E) = Standard_Standard
3556 and then Sloc (Old_E) = Standard_Location
3558 Error_Msg_N ("renamed unit must be a library unit", Name (N));
3560 elsif Present (Parent_Spec (N))
3561 and then Nkind (Unit (Parent_Spec (N))) = N_Generic_Package_Declaration
3562 and then not Is_Child_Unit (Old_E)
3565 ("renamed unit must be a child unit of generic parent", Name (N));
3567 elsif Nkind (N) in N_Generic_Renaming_Declaration
3568 and then Nkind (Name (N)) = N_Expanded_Name
3569 and then Is_Generic_Instance (Entity (Prefix (Name (N))))
3570 and then Is_Generic_Unit (Old_E)
3573 ("renamed generic unit must be a library unit", Name (N));
3575 elsif Is_Package_Or_Generic_Package (Old_E) then
3577 -- Inherit categorization flags
3579 New_E := Defining_Entity (N);
3580 Set_Is_Pure (New_E, Is_Pure (Old_E));
3581 Set_Is_Preelaborated (New_E, Is_Preelaborated (Old_E));
3582 Set_Is_Remote_Call_Interface (New_E,
3583 Is_Remote_Call_Interface (Old_E));
3584 Set_Is_Remote_Types (New_E, Is_Remote_Types (Old_E));
3585 Set_Is_Shared_Passive (New_E, Is_Shared_Passive (Old_E));
3587 end Check_Library_Unit_Renaming;
3593 procedure End_Scope is
3599 Id := First_Entity (Current_Scope);
3600 while Present (Id) loop
3601 -- An entity in the current scope is not necessarily the first one
3602 -- on its homonym chain. Find its predecessor if any,
3603 -- If it is an internal entity, it will not be in the visibility
3604 -- chain altogether, and there is nothing to unchain.
3606 if Id /= Current_Entity (Id) then
3607 Prev := Current_Entity (Id);
3608 while Present (Prev)
3609 and then Present (Homonym (Prev))
3610 and then Homonym (Prev) /= Id
3612 Prev := Homonym (Prev);
3615 -- Skip to end of loop if Id is not in the visibility chain
3617 if No (Prev) or else Homonym (Prev) /= Id then
3625 Set_Is_Immediately_Visible (Id, False);
3627 Outer := Homonym (Id);
3628 while Present (Outer) and then Scope (Outer) = Current_Scope loop
3629 Outer := Homonym (Outer);
3632 -- Reset homonym link of other entities, but do not modify link
3633 -- between entities in current scope, so that the back-end can have
3634 -- a proper count of local overloadings.
3637 Set_Name_Entity_Id (Chars (Id), Outer);
3639 elsif Scope (Prev) /= Scope (Id) then
3640 Set_Homonym (Prev, Outer);
3647 -- If the scope generated freeze actions, place them before the
3648 -- current declaration and analyze them. Type declarations and
3649 -- the bodies of initialization procedures can generate such nodes.
3650 -- We follow the parent chain until we reach a list node, which is
3651 -- the enclosing list of declarations. If the list appears within
3652 -- a protected definition, move freeze nodes outside the protected
3656 (Scope_Stack.Table (Scope_Stack.Last).Pending_Freeze_Actions)
3660 L : constant List_Id := Scope_Stack.Table
3661 (Scope_Stack.Last).Pending_Freeze_Actions;
3664 if Is_Itype (Current_Scope) then
3665 Decl := Associated_Node_For_Itype (Current_Scope);
3667 Decl := Parent (Current_Scope);
3672 while not (Is_List_Member (Decl))
3673 or else Nkind_In (Parent (Decl), N_Protected_Definition,
3676 Decl := Parent (Decl);
3679 Insert_List_Before_And_Analyze (Decl, L);
3688 ---------------------
3689 -- End_Use_Clauses --
3690 ---------------------
3692 procedure End_Use_Clauses (Clause : Node_Id) is
3696 -- Remove Use_Type clauses first, because they affect the
3697 -- visibility of operators in subsequent used packages.
3700 while Present (U) loop
3701 if Nkind (U) = N_Use_Type_Clause then
3705 Next_Use_Clause (U);
3709 while Present (U) loop
3710 if Nkind (U) = N_Use_Package_Clause then
3711 End_Use_Package (U);
3714 Next_Use_Clause (U);
3716 end End_Use_Clauses;
3718 ---------------------
3719 -- End_Use_Package --
3720 ---------------------
3722 procedure End_Use_Package (N : Node_Id) is
3723 Pack_Name : Node_Id;
3728 function Is_Primitive_Operator_In_Use
3730 F : Entity_Id) return Boolean;
3731 -- Check whether Op is a primitive operator of a use-visible type
3733 ----------------------------------
3734 -- Is_Primitive_Operator_In_Use --
3735 ----------------------------------
3737 function Is_Primitive_Operator_In_Use
3739 F : Entity_Id) return Boolean
3741 T : constant Entity_Id := Base_Type (Etype (F));
3743 return In_Use (T) and then Scope (T) = Scope (Op);
3744 end Is_Primitive_Operator_In_Use;
3746 -- Start of processing for End_Use_Package
3749 Pack_Name := First (Names (N));
3750 while Present (Pack_Name) loop
3752 -- Test that Pack_Name actually denotes a package before processing
3754 if Is_Entity_Name (Pack_Name)
3755 and then Ekind (Entity (Pack_Name)) = E_Package
3757 Pack := Entity (Pack_Name);
3759 if In_Open_Scopes (Pack) then
3762 elsif not Redundant_Use (Pack_Name) then
3763 Set_In_Use (Pack, False);
3764 Set_Current_Use_Clause (Pack, Empty);
3766 Id := First_Entity (Pack);
3767 while Present (Id) loop
3769 -- Preserve use-visibility of operators that are primitive
3770 -- operators of a type that is use-visible through an active
3773 if Nkind (Id) = N_Defining_Operator_Symbol
3775 (Is_Primitive_Operator_In_Use
3776 (Id, First_Formal (Id))
3778 (Present (Next_Formal (First_Formal (Id)))
3780 Is_Primitive_Operator_In_Use
3781 (Id, Next_Formal (First_Formal (Id)))))
3786 Set_Is_Potentially_Use_Visible (Id, False);
3789 if Is_Private_Type (Id)
3790 and then Present (Full_View (Id))
3792 Set_Is_Potentially_Use_Visible (Full_View (Id), False);
3798 if Present (Renamed_Object (Pack)) then
3799 Set_In_Use (Renamed_Object (Pack), False);
3800 Set_Current_Use_Clause (Renamed_Object (Pack), Empty);
3803 if Chars (Pack) = Name_System
3804 and then Scope (Pack) = Standard_Standard
3805 and then Present_System_Aux
3807 Id := First_Entity (System_Aux_Id);
3808 while Present (Id) loop
3809 Set_Is_Potentially_Use_Visible (Id, False);
3811 if Is_Private_Type (Id)
3812 and then Present (Full_View (Id))
3814 Set_Is_Potentially_Use_Visible (Full_View (Id), False);
3820 Set_In_Use (System_Aux_Id, False);
3824 Set_Redundant_Use (Pack_Name, False);
3831 if Present (Hidden_By_Use_Clause (N)) then
3832 Elmt := First_Elmt (Hidden_By_Use_Clause (N));
3833 while Present (Elmt) loop
3835 E : constant Entity_Id := Node (Elmt);
3838 -- Reset either Use_Visibility or Direct_Visibility, depending
3839 -- on how the entity was hidden by the use clause.
3841 if In_Use (Scope (E))
3842 and then Used_As_Generic_Actual (Scope (E))
3844 Set_Is_Potentially_Use_Visible (Node (Elmt));
3846 Set_Is_Immediately_Visible (Node (Elmt));
3853 Set_Hidden_By_Use_Clause (N, No_Elist);
3855 end End_Use_Package;
3861 procedure End_Use_Type (N : Node_Id) is
3866 -- Start of processing for End_Use_Type
3869 Id := First (Subtype_Marks (N));
3870 while Present (Id) loop
3872 -- A call to Rtsfind may occur while analyzing a use_type clause,
3873 -- in which case the type marks are not resolved yet, and there is
3874 -- nothing to remove.
3876 if not Is_Entity_Name (Id) or else No (Entity (Id)) then
3882 if T = Any_Type or else From_With_Type (T) then
3885 -- Note that the use_type clause may mention a subtype of the type
3886 -- whose primitive operations have been made visible. Here as
3887 -- elsewhere, it is the base type that matters for visibility.
3889 elsif In_Open_Scopes (Scope (Base_Type (T))) then
3892 elsif not Redundant_Use (Id) then
3893 Set_In_Use (T, False);
3894 Set_In_Use (Base_Type (T), False);
3895 Set_Current_Use_Clause (T, Empty);
3896 Set_Current_Use_Clause (Base_Type (T), Empty);
3903 if Is_Empty_Elmt_List (Used_Operations (N)) then
3907 Elmt := First_Elmt (Used_Operations (N));
3908 while Present (Elmt) loop
3909 Set_Is_Potentially_Use_Visible (Node (Elmt), False);
3915 ----------------------
3916 -- Find_Direct_Name --
3917 ----------------------
3919 procedure Find_Direct_Name (N : Node_Id) is
3924 Inst : Entity_Id := Empty;
3925 -- Enclosing instance, if any
3927 Homonyms : Entity_Id;
3928 -- Saves start of homonym chain
3930 Nvis_Entity : Boolean;
3931 -- Set True to indicate that there is at least one entity on the homonym
3932 -- chain which, while not visible, is visible enough from the user point
3933 -- of view to warrant an error message of "not visible" rather than
3936 Nvis_Is_Private_Subprg : Boolean := False;
3937 -- Ada 2005 (AI-262): Set True to indicate that a form of Beaujolais
3938 -- effect concerning library subprograms has been detected. Used to
3939 -- generate the precise error message.
3941 function From_Actual_Package (E : Entity_Id) return Boolean;
3942 -- Returns true if the entity is declared in a package that is
3943 -- an actual for a formal package of the current instance. Such an
3944 -- entity requires special handling because it may be use-visible
3945 -- but hides directly visible entities defined outside the instance.
3947 function Is_Actual_Parameter return Boolean;
3948 -- This function checks if the node N is an identifier that is an actual
3949 -- parameter of a procedure call. If so it returns True, otherwise it
3950 -- return False. The reason for this check is that at this stage we do
3951 -- not know what procedure is being called if the procedure might be
3952 -- overloaded, so it is premature to go setting referenced flags or
3953 -- making calls to Generate_Reference. We will wait till Resolve_Actuals
3954 -- for that processing
3956 function Known_But_Invisible (E : Entity_Id) return Boolean;
3957 -- This function determines whether the entity E (which is not
3958 -- visible) can reasonably be considered to be known to the writer
3959 -- of the reference. This is a heuristic test, used only for the
3960 -- purposes of figuring out whether we prefer to complain that an
3961 -- entity is undefined or invisible (and identify the declaration
3962 -- of the invisible entity in the latter case). The point here is
3963 -- that we don't want to complain that something is invisible and
3964 -- then point to something entirely mysterious to the writer.
3966 procedure Nvis_Messages;
3967 -- Called if there are no visible entries for N, but there is at least
3968 -- one non-directly visible, or hidden declaration. This procedure
3969 -- outputs an appropriate set of error messages.
3971 procedure Undefined (Nvis : Boolean);
3972 -- This function is called if the current node has no corresponding
3973 -- visible entity or entities. The value set in Msg indicates whether
3974 -- an error message was generated (multiple error messages for the
3975 -- same variable are generally suppressed, see body for details).
3976 -- Msg is True if an error message was generated, False if not. This
3977 -- value is used by the caller to determine whether or not to output
3978 -- additional messages where appropriate. The parameter is set False
3979 -- to get the message "X is undefined", and True to get the message
3980 -- "X is not visible".
3982 -------------------------
3983 -- From_Actual_Package --
3984 -------------------------
3986 function From_Actual_Package (E : Entity_Id) return Boolean is
3987 Scop : constant Entity_Id := Scope (E);
3991 if not In_Instance then
3994 Inst := Current_Scope;
3995 while Present (Inst)
3996 and then Ekind (Inst) /= E_Package
3997 and then not Is_Generic_Instance (Inst)
3999 Inst := Scope (Inst);
4006 Act := First_Entity (Inst);
4007 while Present (Act) loop
4008 if Ekind (Act) = E_Package then
4010 -- Check for end of actuals list
4012 if Renamed_Object (Act) = Inst then
4015 elsif Present (Associated_Formal_Package (Act))
4016 and then Renamed_Object (Act) = Scop
4018 -- Entity comes from (instance of) formal package
4033 end From_Actual_Package;
4035 -------------------------
4036 -- Is_Actual_Parameter --
4037 -------------------------
4039 function Is_Actual_Parameter return Boolean is
4042 Nkind (N) = N_Identifier
4044 (Nkind (Parent (N)) = N_Procedure_Call_Statement
4046 (Nkind (Parent (N)) = N_Parameter_Association
4047 and then N = Explicit_Actual_Parameter (Parent (N))
4048 and then Nkind (Parent (Parent (N))) =
4049 N_Procedure_Call_Statement));
4050 end Is_Actual_Parameter;
4052 -------------------------
4053 -- Known_But_Invisible --
4054 -------------------------
4056 function Known_But_Invisible (E : Entity_Id) return Boolean is
4057 Fname : File_Name_Type;
4060 -- Entities in Standard are always considered to be known
4062 if Sloc (E) <= Standard_Location then
4065 -- An entity that does not come from source is always considered
4066 -- to be unknown, since it is an artifact of code expansion.
4068 elsif not Comes_From_Source (E) then
4071 -- In gnat internal mode, we consider all entities known
4073 elsif GNAT_Mode then
4077 -- Here we have an entity that is not from package Standard, and
4078 -- which comes from Source. See if it comes from an internal file.
4080 Fname := Unit_File_Name (Get_Source_Unit (E));
4082 -- Case of from internal file
4084 if Is_Internal_File_Name (Fname) then
4086 -- Private part entities in internal files are never considered
4087 -- to be known to the writer of normal application code.
4089 if Is_Hidden (E) then
4093 -- Entities from System packages other than System and
4094 -- System.Storage_Elements are not considered to be known.
4095 -- System.Auxxxx files are also considered known to the user.
4097 -- Should refine this at some point to generally distinguish
4098 -- between known and unknown internal files ???
4100 Get_Name_String (Fname);
4105 Name_Buffer (1 .. 2) /= "s-"
4107 Name_Buffer (3 .. 8) = "stoele"
4109 Name_Buffer (3 .. 5) = "aux";
4111 -- If not an internal file, then entity is definitely known,
4112 -- even if it is in a private part (the message generated will
4113 -- note that it is in a private part)
4118 end Known_But_Invisible;
4124 procedure Nvis_Messages is
4125 Comp_Unit : Node_Id;
4127 Found : Boolean := False;
4128 Hidden : Boolean := False;
4132 -- Ada 2005 (AI-262): Generate a precise error concerning the
4133 -- Beaujolais effect that was previously detected
4135 if Nvis_Is_Private_Subprg then
4137 pragma Assert (Nkind (E2) = N_Defining_Identifier
4138 and then Ekind (E2) = E_Function
4139 and then Scope (E2) = Standard_Standard
4140 and then Has_Private_With (E2));
4142 -- Find the sloc corresponding to the private with'ed unit
4144 Comp_Unit := Cunit (Current_Sem_Unit);
4145 Error_Msg_Sloc := No_Location;
4147 Item := First (Context_Items (Comp_Unit));
4148 while Present (Item) loop
4149 if Nkind (Item) = N_With_Clause
4150 and then Private_Present (Item)
4151 and then Entity (Name (Item)) = E2
4153 Error_Msg_Sloc := Sloc (Item);
4160 pragma Assert (Error_Msg_Sloc /= No_Location);
4162 Error_Msg_N ("(Ada 2005): hidden by private with clause #", N);
4166 Undefined (Nvis => True);
4170 -- First loop does hidden declarations
4173 while Present (Ent) loop
4174 if Is_Potentially_Use_Visible (Ent) then
4176 Error_Msg_N -- CODEFIX
4177 ("multiple use clauses cause hiding!", N);
4181 Error_Msg_Sloc := Sloc (Ent);
4182 Error_Msg_N -- CODEFIX
4183 ("hidden declaration#!", N);
4186 Ent := Homonym (Ent);
4189 -- If we found hidden declarations, then that's enough, don't
4190 -- bother looking for non-visible declarations as well.
4196 -- Second loop does non-directly visible declarations
4199 while Present (Ent) loop
4200 if not Is_Potentially_Use_Visible (Ent) then
4202 -- Do not bother the user with unknown entities
4204 if not Known_But_Invisible (Ent) then
4208 Error_Msg_Sloc := Sloc (Ent);
4210 -- Output message noting that there is a non-visible
4211 -- declaration, distinguishing the private part case.
4213 if Is_Hidden (Ent) then
4214 Error_Msg_N ("non-visible (private) declaration#!", N);
4216 -- If the entity is declared in a generic package, it
4217 -- cannot be visible, so there is no point in adding it
4218 -- to the list of candidates if another homograph from a
4219 -- non-generic package has been seen.
4221 elsif Ekind (Scope (Ent)) = E_Generic_Package
4227 Error_Msg_N -- CODEFIX
4228 ("non-visible declaration#!", N);
4230 if Ekind (Scope (Ent)) /= E_Generic_Package then
4234 if Is_Compilation_Unit (Ent)
4236 Nkind (Parent (Parent (N))) = N_Use_Package_Clause
4238 Error_Msg_Qual_Level := 99;
4239 Error_Msg_NE -- CODEFIX
4240 ("\\missing `WITH &;`", N, Ent);
4241 Error_Msg_Qual_Level := 0;
4244 if Ekind (Ent) = E_Discriminant
4245 and then Present (Corresponding_Discriminant (Ent))
4246 and then Scope (Corresponding_Discriminant (Ent)) =
4250 ("inherited discriminant not allowed here" &
4251 " (RM 3.8 (12), 3.8.1 (6))!", N);
4255 -- Set entity and its containing package as referenced. We
4256 -- can't be sure of this, but this seems a better choice
4257 -- to avoid unused entity messages.
4259 if Comes_From_Source (Ent) then
4260 Set_Referenced (Ent);
4261 Set_Referenced (Cunit_Entity (Get_Source_Unit (Ent)));
4266 Ent := Homonym (Ent);
4275 procedure Undefined (Nvis : Boolean) is
4276 Emsg : Error_Msg_Id;
4279 -- We should never find an undefined internal name. If we do, then
4280 -- see if we have previous errors. If so, ignore on the grounds that
4281 -- it is probably a cascaded message (e.g. a block label from a badly
4282 -- formed block). If no previous errors, then we have a real internal
4283 -- error of some kind so raise an exception.
4285 if Is_Internal_Name (Chars (N)) then
4286 if Total_Errors_Detected /= 0 then
4289 raise Program_Error;
4293 -- A very specialized error check, if the undefined variable is
4294 -- a case tag, and the case type is an enumeration type, check
4295 -- for a possible misspelling, and if so, modify the identifier
4297 -- Named aggregate should also be handled similarly ???
4299 if Nkind (N) = N_Identifier
4300 and then Nkind (Parent (N)) = N_Case_Statement_Alternative
4303 Case_Stm : constant Node_Id := Parent (Parent (N));
4304 Case_Typ : constant Entity_Id := Etype (Expression (Case_Stm));
4309 if Is_Enumeration_Type (Case_Typ)
4310 and then not Is_Standard_Character_Type (Case_Typ)
4312 Lit := First_Literal (Case_Typ);
4313 Get_Name_String (Chars (Lit));
4315 if Chars (Lit) /= Chars (N)
4316 and then Is_Bad_Spelling_Of (Chars (N), Chars (Lit)) then
4317 Error_Msg_Node_2 := Lit;
4318 Error_Msg_N -- CODEFIX
4319 ("& is undefined, assume misspelling of &", N);
4320 Rewrite (N, New_Occurrence_Of (Lit, Sloc (N)));
4324 Lit := Next_Literal (Lit);
4329 -- Normal processing
4331 Set_Entity (N, Any_Id);
4332 Set_Etype (N, Any_Type);
4334 -- We use the table Urefs to keep track of entities for which we
4335 -- have issued errors for undefined references. Multiple errors
4336 -- for a single name are normally suppressed, however we modify
4337 -- the error message to alert the programmer to this effect.
4339 for J in Urefs.First .. Urefs.Last loop
4340 if Chars (N) = Chars (Urefs.Table (J).Node) then
4341 if Urefs.Table (J).Err /= No_Error_Msg
4342 and then Sloc (N) /= Urefs.Table (J).Loc
4344 Error_Msg_Node_1 := Urefs.Table (J).Node;
4346 if Urefs.Table (J).Nvis then
4347 Change_Error_Text (Urefs.Table (J).Err,
4348 "& is not visible (more references follow)");
4350 Change_Error_Text (Urefs.Table (J).Err,
4351 "& is undefined (more references follow)");
4354 Urefs.Table (J).Err := No_Error_Msg;
4357 -- Although we will set Msg False, and thus suppress the
4358 -- message, we also set Error_Posted True, to avoid any
4359 -- cascaded messages resulting from the undefined reference.
4362 Set_Error_Posted (N, True);
4367 -- If entry not found, this is first undefined occurrence
4370 Error_Msg_N ("& is not visible!", N);
4374 Error_Msg_N ("& is undefined!", N);
4377 -- A very bizarre special check, if the undefined identifier
4378 -- is put or put_line, then add a special error message (since
4379 -- this is a very common error for beginners to make).
4381 if Chars (N) = Name_Put or else Chars (N) = Name_Put_Line then
4382 Error_Msg_N -- CODEFIX
4383 ("\\possible missing `WITH Ada.Text_'I'O; " &
4384 "USE Ada.Text_'I'O`!", N);
4386 -- Another special check if N is the prefix of a selected
4387 -- component which is a known unit, add message complaining
4388 -- about missing with for this unit.
4390 elsif Nkind (Parent (N)) = N_Selected_Component
4391 and then N = Prefix (Parent (N))
4392 and then Is_Known_Unit (Parent (N))
4394 Error_Msg_Node_2 := Selector_Name (Parent (N));
4395 Error_Msg_N -- CODEFIX
4396 ("\\missing `WITH &.&;`", Prefix (Parent (N)));
4399 -- Now check for possible misspellings
4403 Ematch : Entity_Id := Empty;
4405 Last_Name_Id : constant Name_Id :=
4406 Name_Id (Nat (First_Name_Id) +
4407 Name_Entries_Count - 1);
4410 for Nam in First_Name_Id .. Last_Name_Id loop
4411 E := Get_Name_Entity_Id (Nam);
4414 and then (Is_Immediately_Visible (E)
4416 Is_Potentially_Use_Visible (E))
4418 if Is_Bad_Spelling_Of (Chars (N), Nam) then
4425 if Present (Ematch) then
4426 Error_Msg_NE -- CODEFIX
4427 ("\possible misspelling of&", N, Ematch);
4432 -- Make entry in undefined references table unless the full errors
4433 -- switch is set, in which case by refraining from generating the
4434 -- table entry, we guarantee that we get an error message for every
4435 -- undefined reference.
4437 if not All_Errors_Mode then
4448 -- Start of processing for Find_Direct_Name
4451 -- If the entity pointer is already set, this is an internal node, or
4452 -- a node that is analyzed more than once, after a tree modification.
4453 -- In such a case there is no resolution to perform, just set the type.
4455 if Present (Entity (N)) then
4456 if Is_Type (Entity (N)) then
4457 Set_Etype (N, Entity (N));
4461 Entyp : constant Entity_Id := Etype (Entity (N));
4464 -- One special case here. If the Etype field is already set,
4465 -- and references the packed array type corresponding to the
4466 -- etype of the referenced entity, then leave it alone. This
4467 -- happens for trees generated from Exp_Pakd, where expressions
4468 -- can be deliberately "mis-typed" to the packed array type.
4470 if Is_Array_Type (Entyp)
4471 and then Is_Packed (Entyp)
4472 and then Present (Etype (N))
4473 and then Etype (N) = Packed_Array_Type (Entyp)
4477 -- If not that special case, then just reset the Etype
4480 Set_Etype (N, Etype (Entity (N)));
4488 -- Here if Entity pointer was not set, we need full visibility analysis
4489 -- First we generate debugging output if the debug E flag is set.
4491 if Debug_Flag_E then
4492 Write_Str ("Looking for ");
4493 Write_Name (Chars (N));
4497 Homonyms := Current_Entity (N);
4498 Nvis_Entity := False;
4501 while Present (E) loop
4503 -- If entity is immediately visible or potentially use visible, then
4504 -- process the entity and we are done.
4506 if Is_Immediately_Visible (E) then
4507 goto Immediately_Visible_Entity;
4509 elsif Is_Potentially_Use_Visible (E) then
4510 goto Potentially_Use_Visible_Entity;
4512 -- Note if a known but invisible entity encountered
4514 elsif Known_But_Invisible (E) then
4515 Nvis_Entity := True;
4518 -- Move to next entity in chain and continue search
4523 -- If no entries on homonym chain that were potentially visible,
4524 -- and no entities reasonably considered as non-visible, then
4525 -- we have a plain undefined reference, with no additional
4526 -- explanation required!
4528 if not Nvis_Entity then
4529 Undefined (Nvis => False);
4531 -- Otherwise there is at least one entry on the homonym chain that
4532 -- is reasonably considered as being known and non-visible.
4540 -- Processing for a potentially use visible entry found. We must search
4541 -- the rest of the homonym chain for two reasons. First, if there is a
4542 -- directly visible entry, then none of the potentially use-visible
4543 -- entities are directly visible (RM 8.4(10)). Second, we need to check
4544 -- for the case of multiple potentially use-visible entries hiding one
4545 -- another and as a result being non-directly visible (RM 8.4(11)).
4547 <<Potentially_Use_Visible_Entity>> declare
4548 Only_One_Visible : Boolean := True;
4549 All_Overloadable : Boolean := Is_Overloadable (E);
4553 while Present (E2) loop
4554 if Is_Immediately_Visible (E2) then
4556 -- If the use-visible entity comes from the actual for a
4557 -- formal package, it hides a directly visible entity from
4558 -- outside the instance.
4560 if From_Actual_Package (E)
4561 and then Scope_Depth (E2) < Scope_Depth (Inst)
4566 goto Immediately_Visible_Entity;
4569 elsif Is_Potentially_Use_Visible (E2) then
4570 Only_One_Visible := False;
4571 All_Overloadable := All_Overloadable and Is_Overloadable (E2);
4573 -- Ada 2005 (AI-262): Protect against a form of Beaujolais effect
4574 -- that can occur in private_with clauses. Example:
4577 -- private with B; package A is
4578 -- package C is function B return Integer;
4580 -- V1 : Integer := B;
4581 -- private function B return Integer;
4582 -- V2 : Integer := B;
4585 -- V1 resolves to A.B, but V2 resolves to library unit B
4587 elsif Ekind (E2) = E_Function
4588 and then Scope (E2) = Standard_Standard
4589 and then Has_Private_With (E2)
4591 Only_One_Visible := False;
4592 All_Overloadable := False;
4593 Nvis_Is_Private_Subprg := True;
4600 -- On falling through this loop, we have checked that there are no
4601 -- immediately visible entities. Only_One_Visible is set if exactly
4602 -- one potentially use visible entity exists. All_Overloadable is
4603 -- set if all the potentially use visible entities are overloadable.
4604 -- The condition for legality is that either there is one potentially
4605 -- use visible entity, or if there is more than one, then all of them
4606 -- are overloadable.
4608 if Only_One_Visible or All_Overloadable then
4611 -- If there is more than one potentially use-visible entity and at
4612 -- least one of them non-overloadable, we have an error (RM 8.4(11).
4613 -- Note that E points to the first such entity on the homonym list.
4614 -- Special case: if one of the entities is declared in an actual
4615 -- package, it was visible in the generic, and takes precedence over
4616 -- other entities that are potentially use-visible. Same if it is
4617 -- declared in a local instantiation of the current instance.
4622 -- Find current instance
4624 Inst := Current_Scope;
4625 while Present (Inst)
4626 and then Inst /= Standard_Standard
4628 if Is_Generic_Instance (Inst) then
4632 Inst := Scope (Inst);
4636 while Present (E2) loop
4637 if From_Actual_Package (E2)
4639 (Is_Generic_Instance (Scope (E2))
4640 and then Scope_Depth (Scope (E2)) > Scope_Depth (Inst))
4653 Is_Predefined_File_Name (Unit_File_Name (Current_Sem_Unit))
4655 -- A use-clause in the body of a system file creates conflict
4656 -- with some entity in a user scope, while rtsfind is active.
4657 -- Keep only the entity coming from another predefined unit.
4660 while Present (E2) loop
4661 if Is_Predefined_File_Name
4662 (Unit_File_Name (Get_Source_Unit (Sloc (E2))))
4671 -- Entity must exist because predefined unit is correct
4673 raise Program_Error;
4682 -- Come here with E set to the first immediately visible entity on
4683 -- the homonym chain. This is the one we want unless there is another
4684 -- immediately visible entity further on in the chain for an inner
4685 -- scope (RM 8.3(8)).
4687 <<Immediately_Visible_Entity>> declare
4692 -- Find scope level of initial entity. When compiling through
4693 -- Rtsfind, the previous context is not completely invisible, and
4694 -- an outer entity may appear on the chain, whose scope is below
4695 -- the entry for Standard that delimits the current scope stack.
4696 -- Indicate that the level for this spurious entry is outside of
4697 -- the current scope stack.
4699 Level := Scope_Stack.Last;
4701 Scop := Scope_Stack.Table (Level).Entity;
4702 exit when Scop = Scope (E);
4704 exit when Scop = Standard_Standard;
4707 -- Now search remainder of homonym chain for more inner entry
4708 -- If the entity is Standard itself, it has no scope, and we
4709 -- compare it with the stack entry directly.
4712 while Present (E2) loop
4713 if Is_Immediately_Visible (E2) then
4715 -- If a generic package contains a local declaration that
4716 -- has the same name as the generic, there may be a visibility
4717 -- conflict in an instance, where the local declaration must
4718 -- also hide the name of the corresponding package renaming.
4719 -- We check explicitly for a package declared by a renaming,
4720 -- whose renamed entity is an instance that is on the scope
4721 -- stack, and that contains a homonym in the same scope. Once
4722 -- we have found it, we know that the package renaming is not
4723 -- immediately visible, and that the identifier denotes the
4724 -- other entity (and its homonyms if overloaded).
4726 if Scope (E) = Scope (E2)
4727 and then Ekind (E) = E_Package
4728 and then Present (Renamed_Object (E))
4729 and then Is_Generic_Instance (Renamed_Object (E))
4730 and then In_Open_Scopes (Renamed_Object (E))
4731 and then Comes_From_Source (N)
4733 Set_Is_Immediately_Visible (E, False);
4737 for J in Level + 1 .. Scope_Stack.Last loop
4738 if Scope_Stack.Table (J).Entity = Scope (E2)
4739 or else Scope_Stack.Table (J).Entity = E2
4752 -- At the end of that loop, E is the innermost immediately
4753 -- visible entity, so we are all set.
4756 -- Come here with entity found, and stored in E
4760 -- Check violation of No_Wide_Characters restriction
4762 Check_Wide_Character_Restriction (E, N);
4764 -- When distribution features are available (Get_PCS_Name /=
4765 -- Name_No_DSA), a remote access-to-subprogram type is converted
4766 -- into a record type holding whatever information is needed to
4767 -- perform a remote call on an RCI subprogram. In that case we
4768 -- rewrite any occurrence of the RAS type into the equivalent record
4769 -- type here. 'Access attribute references and RAS dereferences are
4770 -- then implemented using specific TSSs. However when distribution is
4771 -- not available (case of Get_PCS_Name = Name_No_DSA), we bypass the
4772 -- generation of these TSSs, and we must keep the RAS type in its
4773 -- original access-to-subprogram form (since all calls through a
4774 -- value of such type will be local anyway in the absence of a PCS).
4776 if Comes_From_Source (N)
4777 and then Is_Remote_Access_To_Subprogram_Type (E)
4778 and then Expander_Active
4779 and then Get_PCS_Name /= Name_No_DSA
4782 New_Occurrence_Of (Equivalent_Type (E), Sloc (N)));
4786 -- Set the entity. Note that the reason we call Set_Entity for the
4787 -- overloadable case, as opposed to Set_Entity_With_Style_Check is
4788 -- that in the overloaded case, the initial call can set the wrong
4789 -- homonym. The call that sets the right homonym is in Sem_Res and
4790 -- that call does use Set_Entity_With_Style_Check, so we don't miss
4793 if Is_Overloadable (E) then
4796 Set_Entity_With_Style_Check (N, E);
4802 Set_Etype (N, Get_Full_View (Etype (E)));
4805 if Debug_Flag_E then
4806 Write_Str (" found ");
4807 Write_Entity_Info (E, " ");
4810 -- If the Ekind of the entity is Void, it means that all homonyms
4811 -- are hidden from all visibility (RM 8.3(5,14-20)). However, this
4812 -- test is skipped if the current scope is a record and the name is
4813 -- a pragma argument expression (case of Atomic and Volatile pragmas
4814 -- and possibly other similar pragmas added later, which are allowed
4815 -- to reference components in the current record).
4817 if Ekind (E) = E_Void
4819 (not Is_Record_Type (Current_Scope)
4820 or else Nkind (Parent (N)) /= N_Pragma_Argument_Association)
4822 Premature_Usage (N);
4824 -- If the entity is overloadable, collect all interpretations of the
4825 -- name for subsequent overload resolution. We optimize a bit here to
4826 -- do this only if we have an overloadable entity that is not on its
4827 -- own on the homonym chain.
4829 elsif Is_Overloadable (E)
4830 and then (Present (Homonym (E)) or else Current_Entity (N) /= E)
4832 Collect_Interps (N);
4834 -- If no homonyms were visible, the entity is unambiguous
4836 if not Is_Overloaded (N) then
4837 if not Is_Actual_Parameter then
4838 Generate_Reference (E, N);
4842 -- Case of non-overloadable entity, set the entity providing that
4843 -- we do not have the case of a discriminant reference within a
4844 -- default expression. Such references are replaced with the
4845 -- corresponding discriminal, which is the formal corresponding to
4846 -- to the discriminant in the initialization procedure.
4849 -- Entity is unambiguous, indicate that it is referenced here
4851 -- For a renaming of an object, always generate simple reference,
4852 -- we don't try to keep track of assignments in this case.
4854 if Is_Object (E) and then Present (Renamed_Object (E)) then
4855 Generate_Reference (E, N);
4857 -- If the renamed entity is a private protected component,
4858 -- reference the original component as well. This needs to be
4859 -- done because the private renamings are installed before any
4860 -- analysis has occurred. Reference to a private component will
4861 -- resolve to the renaming and the original component will be
4862 -- left unreferenced, hence the following.
4864 if Is_Prival (E) then
4865 Generate_Reference (Prival_Link (E), N);
4868 -- One odd case is that we do not want to set the Referenced flag
4869 -- if the entity is a label, and the identifier is the label in
4870 -- the source, since this is not a reference from the point of
4871 -- view of the user.
4873 elsif Nkind (Parent (N)) = N_Label then
4875 R : constant Boolean := Referenced (E);
4878 -- Generate reference unless this is an actual parameter
4879 -- (see comment below)
4881 if Is_Actual_Parameter then
4882 Generate_Reference (E, N);
4883 Set_Referenced (E, R);
4887 -- Normal case, not a label: generate reference
4889 -- ??? It is too early to generate a reference here even if the
4890 -- entity is unambiguous, because the tree is not sufficiently
4891 -- typed at this point for Generate_Reference to determine
4892 -- whether this reference modifies the denoted object (because
4893 -- implicit dereferences cannot be identified prior to full type
4896 -- The Is_Actual_Parameter routine takes care of one of these
4897 -- cases but there are others probably ???
4899 -- If the entity is the LHS of an assignment, and is a variable
4900 -- (rather than a package prefix), we can mark it as a
4901 -- modification right away, to avoid duplicate references.
4904 if not Is_Actual_Parameter then
4906 and then Ekind (E) /= E_Package
4907 and then Ekind (E) /= E_Generic_Package
4909 Generate_Reference (E, N, 'm');
4911 Generate_Reference (E, N);
4915 Check_Nested_Access (E);
4918 Set_Entity_Or_Discriminal (N, E);
4920 if Ada_Version >= Ada_2012
4922 (Nkind (Parent (N)) in N_Subexpr
4923 or else Nkind (Parent (N)) = N_Object_Declaration)
4925 Check_Implicit_Dereference (N, Etype (E));
4929 end Find_Direct_Name;
4931 ------------------------
4932 -- Find_Expanded_Name --
4933 ------------------------
4935 -- This routine searches the homonym chain of the entity until it finds
4936 -- an entity declared in the scope denoted by the prefix. If the entity
4937 -- is private, it may nevertheless be immediately visible, if we are in
4938 -- the scope of its declaration.
4940 procedure Find_Expanded_Name (N : Node_Id) is
4941 Selector : constant Node_Id := Selector_Name (N);
4942 Candidate : Entity_Id := Empty;
4948 P_Name := Entity (Prefix (N));
4951 -- If the prefix is a renamed package, look for the entity in the
4952 -- original package.
4954 if Ekind (P_Name) = E_Package
4955 and then Present (Renamed_Object (P_Name))
4957 P_Name := Renamed_Object (P_Name);
4959 -- Rewrite node with entity field pointing to renamed object
4961 Rewrite (Prefix (N), New_Copy (Prefix (N)));
4962 Set_Entity (Prefix (N), P_Name);
4964 -- If the prefix is an object of a concurrent type, look for
4965 -- the entity in the associated task or protected type.
4967 elsif Is_Concurrent_Type (Etype (P_Name)) then
4968 P_Name := Etype (P_Name);
4971 Id := Current_Entity (Selector);
4974 Is_New_Candidate : Boolean;
4977 while Present (Id) loop
4978 if Scope (Id) = P_Name then
4980 Is_New_Candidate := True;
4982 -- Ada 2005 (AI-217): Handle shadow entities associated with types
4983 -- declared in limited-withed nested packages. We don't need to
4984 -- handle E_Incomplete_Subtype entities because the entities in
4985 -- the limited view are always E_Incomplete_Type entities (see
4986 -- Build_Limited_Views). Regarding the expression used to evaluate
4987 -- the scope, it is important to note that the limited view also
4988 -- has shadow entities associated nested packages. For this reason
4989 -- the correct scope of the entity is the scope of the real entity
4990 -- The non-limited view may itself be incomplete, in which case
4991 -- get the full view if available.
4993 elsif From_With_Type (Id)
4994 and then Is_Type (Id)
4995 and then Ekind (Id) = E_Incomplete_Type
4996 and then Present (Non_Limited_View (Id))
4997 and then Scope (Non_Limited_View (Id)) = P_Name
4999 Candidate := Get_Full_View (Non_Limited_View (Id));
5000 Is_New_Candidate := True;
5003 Is_New_Candidate := False;
5006 if Is_New_Candidate then
5007 if Is_Child_Unit (Id) then
5008 exit when Is_Visible_Child_Unit (Id)
5009 or else Is_Immediately_Visible (Id);
5012 exit when not Is_Hidden (Id)
5013 or else Is_Immediately_Visible (Id);
5022 and then (Ekind (P_Name) = E_Procedure
5024 Ekind (P_Name) = E_Function)
5025 and then Is_Generic_Instance (P_Name)
5027 -- Expanded name denotes entity in (instance of) generic subprogram.
5028 -- The entity may be in the subprogram instance, or may denote one of
5029 -- the formals, which is declared in the enclosing wrapper package.
5031 P_Name := Scope (P_Name);
5033 Id := Current_Entity (Selector);
5034 while Present (Id) loop
5035 exit when Scope (Id) = P_Name;
5040 if No (Id) or else Chars (Id) /= Chars (Selector) then
5041 Set_Etype (N, Any_Type);
5043 -- If we are looking for an entity defined in System, try to find it
5044 -- in the child package that may have been provided as an extension
5045 -- to System. The Extend_System pragma will have supplied the name of
5046 -- the extension, which may have to be loaded.
5048 if Chars (P_Name) = Name_System
5049 and then Scope (P_Name) = Standard_Standard
5050 and then Present (System_Extend_Unit)
5051 and then Present_System_Aux (N)
5053 Set_Entity (Prefix (N), System_Aux_Id);
5054 Find_Expanded_Name (N);
5057 elsif Nkind (Selector) = N_Operator_Symbol
5058 and then Has_Implicit_Operator (N)
5060 -- There is an implicit instance of the predefined operator in
5061 -- the given scope. The operator entity is defined in Standard.
5062 -- Has_Implicit_Operator makes the node into an Expanded_Name.
5066 elsif Nkind (Selector) = N_Character_Literal
5067 and then Has_Implicit_Character_Literal (N)
5069 -- If there is no literal defined in the scope denoted by the
5070 -- prefix, the literal may belong to (a type derived from)
5071 -- Standard_Character, for which we have no explicit literals.
5076 -- If the prefix is a single concurrent object, use its name in
5077 -- the error message, rather than that of the anonymous type.
5079 if Is_Concurrent_Type (P_Name)
5080 and then Is_Internal_Name (Chars (P_Name))
5082 Error_Msg_Node_2 := Entity (Prefix (N));
5084 Error_Msg_Node_2 := P_Name;
5087 if P_Name = System_Aux_Id then
5088 P_Name := Scope (P_Name);
5089 Set_Entity (Prefix (N), P_Name);
5092 if Present (Candidate) then
5094 -- If we know that the unit is a child unit we can give a more
5095 -- accurate error message.
5097 if Is_Child_Unit (Candidate) then
5099 -- If the candidate is a private child unit and we are in
5100 -- the visible part of a public unit, specialize the error
5101 -- message. There might be a private with_clause for it,
5102 -- but it is not currently active.
5104 if Is_Private_Descendant (Candidate)
5105 and then Ekind (Current_Scope) = E_Package
5106 and then not In_Private_Part (Current_Scope)
5107 and then not Is_Private_Descendant (Current_Scope)
5109 Error_Msg_N ("private child unit& is not visible here",
5112 -- Normal case where we have a missing with for a child unit
5115 Error_Msg_Qual_Level := 99;
5116 Error_Msg_NE -- CODEFIX
5117 ("missing `WITH &;`", Selector, Candidate);
5118 Error_Msg_Qual_Level := 0;
5121 -- Here we don't know that this is a child unit
5124 Error_Msg_NE ("& is not a visible entity of&", N, Selector);
5128 -- Within the instantiation of a child unit, the prefix may
5129 -- denote the parent instance, but the selector has the name
5130 -- of the original child. Find whether we are within the
5131 -- corresponding instance, and get the proper entity, which
5132 -- can only be an enclosing scope.
5135 and then In_Open_Scopes (P_Name)
5136 and then Is_Generic_Instance (P_Name)
5139 S : Entity_Id := Current_Scope;
5143 for J in reverse 0 .. Scope_Stack.Last loop
5144 S := Scope_Stack.Table (J).Entity;
5146 exit when S = Standard_Standard;
5148 if Ekind_In (S, E_Function,
5152 P := Generic_Parent (Specification
5153 (Unit_Declaration_Node (S)));
5156 and then Chars (Scope (P)) = Chars (O_Name)
5157 and then Chars (P) = Chars (Selector)
5168 -- If this is a selection from Ada, System or Interfaces, then
5169 -- we assume a missing with for the corresponding package.
5171 if Is_Known_Unit (N) then
5172 if not Error_Posted (N) then
5173 Error_Msg_Node_2 := Selector;
5174 Error_Msg_N -- CODEFIX
5175 ("missing `WITH &.&;`", Prefix (N));
5178 -- If this is a selection from a dummy package, then suppress
5179 -- the error message, of course the entity is missing if the
5180 -- package is missing!
5182 elsif Sloc (Error_Msg_Node_2) = No_Location then
5185 -- Here we have the case of an undefined component
5189 -- The prefix may hide a homonym in the context that
5190 -- declares the desired entity. This error can use a
5191 -- specialized message.
5193 if In_Open_Scopes (P_Name)
5194 and then Present (Homonym (P_Name))
5195 and then Is_Compilation_Unit (Homonym (P_Name))
5197 (Is_Immediately_Visible (Homonym (P_Name))
5198 or else Is_Visible_Child_Unit (Homonym (P_Name)))
5201 H : constant Entity_Id := Homonym (P_Name);
5204 Id := First_Entity (H);
5205 while Present (Id) loop
5206 if Chars (Id) = Chars (Selector) then
5207 Error_Msg_Qual_Level := 99;
5208 Error_Msg_Name_1 := Chars (Selector);
5210 ("% not declared in&", N, P_Name);
5212 ("\use fully qualified name starting with"
5213 & " Standard to make& visible", N, H);
5214 Error_Msg_Qual_Level := 0;
5221 -- If not found, standard error message
5223 Error_Msg_NE ("& not declared in&", N, Selector);
5229 Error_Msg_NE ("& not declared in&", N, Selector);
5232 -- Check for misspelling of some entity in prefix
5234 Id := First_Entity (P_Name);
5235 while Present (Id) loop
5236 if Is_Bad_Spelling_Of (Chars (Id), Chars (Selector))
5237 and then not Is_Internal_Name (Chars (Id))
5239 Error_Msg_NE -- CODEFIX
5240 ("possible misspelling of&", Selector, Id);
5247 -- Specialize the message if this may be an instantiation
5248 -- of a child unit that was not mentioned in the context.
5250 if Nkind (Parent (N)) = N_Package_Instantiation
5251 and then Is_Generic_Instance (Entity (Prefix (N)))
5252 and then Is_Compilation_Unit
5253 (Generic_Parent (Parent (Entity (Prefix (N)))))
5255 Error_Msg_Node_2 := Selector;
5256 Error_Msg_N -- CODEFIX
5257 ("\missing `WITH &.&;`", Prefix (N));
5267 if Comes_From_Source (N)
5268 and then Is_Remote_Access_To_Subprogram_Type (Id)
5269 and then Present (Equivalent_Type (Id))
5271 -- If we are not actually generating distribution code (i.e. the
5272 -- current PCS is the dummy non-distributed version), then the
5273 -- Equivalent_Type will be missing, and Id should be treated as
5274 -- a regular access-to-subprogram type.
5276 Id := Equivalent_Type (Id);
5277 Set_Chars (Selector, Chars (Id));
5280 -- Ada 2005 (AI-50217): Check usage of entities in limited withed units
5282 if Ekind (P_Name) = E_Package
5283 and then From_With_Type (P_Name)
5285 if From_With_Type (Id)
5286 or else Is_Type (Id)
5287 or else Ekind (Id) = E_Package
5292 ("limited withed package can only be used to access "
5293 & "incomplete types",
5298 if Is_Task_Type (P_Name)
5299 and then ((Ekind (Id) = E_Entry
5300 and then Nkind (Parent (N)) /= N_Attribute_Reference)
5302 (Ekind (Id) = E_Entry_Family
5304 Nkind (Parent (Parent (N))) /= N_Attribute_Reference))
5306 -- It is an entry call after all, either to the current task (which
5307 -- will deadlock) or to an enclosing task.
5309 Analyze_Selected_Component (N);
5313 Change_Selected_Component_To_Expanded_Name (N);
5315 -- Do style check and generate reference, but skip both steps if this
5316 -- entity has homonyms, since we may not have the right homonym set yet.
5317 -- The proper homonym will be set during the resolve phase.
5319 if Has_Homonym (Id) then
5322 Set_Entity_Or_Discriminal (N, Id);
5325 Generate_Reference (Id, N, 'm');
5327 Generate_Reference (Id, N);
5331 if Is_Type (Id) then
5334 Set_Etype (N, Get_Full_View (Etype (Id)));
5337 -- Check for violation of No_Wide_Characters
5339 Check_Wide_Character_Restriction (Id, N);
5341 -- If the Ekind of the entity is Void, it means that all homonyms are
5342 -- hidden from all visibility (RM 8.3(5,14-20)).
5344 if Ekind (Id) = E_Void then
5345 Premature_Usage (N);
5347 elsif Is_Overloadable (Id)
5348 and then Present (Homonym (Id))
5351 H : Entity_Id := Homonym (Id);
5354 while Present (H) loop
5355 if Scope (H) = Scope (Id)
5358 or else Is_Immediately_Visible (H))
5360 Collect_Interps (N);
5367 -- If an extension of System is present, collect possible explicit
5368 -- overloadings declared in the extension.
5370 if Chars (P_Name) = Name_System
5371 and then Scope (P_Name) = Standard_Standard
5372 and then Present (System_Extend_Unit)
5373 and then Present_System_Aux (N)
5375 H := Current_Entity (Id);
5377 while Present (H) loop
5378 if Scope (H) = System_Aux_Id then
5379 Add_One_Interp (N, H, Etype (H));
5388 if Nkind (Selector_Name (N)) = N_Operator_Symbol
5389 and then Scope (Id) /= Standard_Standard
5391 -- In addition to user-defined operators in the given scope, there
5392 -- may be an implicit instance of the predefined operator. The
5393 -- operator (defined in Standard) is found in Has_Implicit_Operator,
5394 -- and added to the interpretations. Procedure Add_One_Interp will
5395 -- determine which hides which.
5397 if Has_Implicit_Operator (N) then
5401 end Find_Expanded_Name;
5403 -------------------------
5404 -- Find_Renamed_Entity --
5405 -------------------------
5407 function Find_Renamed_Entity
5411 Is_Actual : Boolean := False) return Entity_Id
5414 I1 : Interp_Index := 0; -- Suppress junk warnings
5420 function Enclosing_Instance return Entity_Id;
5421 -- If the renaming determines the entity for the default of a formal
5422 -- subprogram nested within another instance, choose the innermost
5423 -- candidate. This is because if the formal has a box, and we are within
5424 -- an enclosing instance where some candidate interpretations are local
5425 -- to this enclosing instance, we know that the default was properly
5426 -- resolved when analyzing the generic, so we prefer the local
5427 -- candidates to those that are external. This is not always the case
5428 -- but is a reasonable heuristic on the use of nested generics. The
5429 -- proper solution requires a full renaming model.
5431 function Is_Visible_Operation (Op : Entity_Id) return Boolean;
5432 -- If the renamed entity is an implicit operator, check whether it is
5433 -- visible because its operand type is properly visible. This check
5434 -- applies to explicit renamed entities that appear in the source in a
5435 -- renaming declaration or a formal subprogram instance, but not to
5436 -- default generic actuals with a name.
5438 function Report_Overload return Entity_Id;
5439 -- List possible interpretations, and specialize message in the
5440 -- case of a generic actual.
5442 function Within (Inner, Outer : Entity_Id) return Boolean;
5443 -- Determine whether a candidate subprogram is defined within the
5444 -- enclosing instance. If yes, it has precedence over outer candidates.
5446 ------------------------
5447 -- Enclosing_Instance --
5448 ------------------------
5450 function Enclosing_Instance return Entity_Id is
5454 if not Is_Generic_Instance (Current_Scope)
5455 and then not Is_Actual
5460 S := Scope (Current_Scope);
5461 while S /= Standard_Standard loop
5462 if Is_Generic_Instance (S) then
5470 end Enclosing_Instance;
5472 --------------------------
5473 -- Is_Visible_Operation --
5474 --------------------------
5476 function Is_Visible_Operation (Op : Entity_Id) return Boolean is
5482 if Ekind (Op) /= E_Operator
5483 or else Scope (Op) /= Standard_Standard
5484 or else (In_Instance
5487 or else Present (Enclosing_Instance)))
5492 -- For a fixed point type operator, check the resulting type,
5493 -- because it may be a mixed mode integer * fixed operation.
5495 if Present (Next_Formal (First_Formal (New_S)))
5496 and then Is_Fixed_Point_Type (Etype (New_S))
5498 Typ := Etype (New_S);
5500 Typ := Etype (First_Formal (New_S));
5503 Btyp := Base_Type (Typ);
5505 if Nkind (Nam) /= N_Expanded_Name then
5506 return (In_Open_Scopes (Scope (Btyp))
5507 or else Is_Potentially_Use_Visible (Btyp)
5508 or else In_Use (Btyp)
5509 or else In_Use (Scope (Btyp)));
5512 Scop := Entity (Prefix (Nam));
5514 if Ekind (Scop) = E_Package
5515 and then Present (Renamed_Object (Scop))
5517 Scop := Renamed_Object (Scop);
5520 -- Operator is visible if prefix of expanded name denotes
5521 -- scope of type, or else type is defined in System_Aux
5522 -- and the prefix denotes System.
5524 return Scope (Btyp) = Scop
5525 or else (Scope (Btyp) = System_Aux_Id
5526 and then Scope (Scope (Btyp)) = Scop);
5529 end Is_Visible_Operation;
5535 function Within (Inner, Outer : Entity_Id) return Boolean is
5539 Sc := Scope (Inner);
5540 while Sc /= Standard_Standard loop
5551 ---------------------
5552 -- Report_Overload --
5553 ---------------------
5555 function Report_Overload return Entity_Id is
5558 Error_Msg_NE -- CODEFIX
5559 ("ambiguous actual subprogram&, " &
5560 "possible interpretations:", N, Nam);
5562 Error_Msg_N -- CODEFIX
5563 ("ambiguous subprogram, " &
5564 "possible interpretations:", N);
5567 List_Interps (Nam, N);
5569 end Report_Overload;
5571 -- Start of processing for Find_Renamed_Entity
5575 Candidate_Renaming := Empty;
5577 if not Is_Overloaded (Nam) then
5578 if Entity_Matches_Spec (Entity (Nam), New_S) then
5579 Candidate_Renaming := New_S;
5581 if Is_Visible_Operation (Entity (Nam)) then
5582 Old_S := Entity (Nam);
5586 Present (First_Formal (Entity (Nam)))
5587 and then Present (First_Formal (New_S))
5588 and then (Base_Type (Etype (First_Formal (Entity (Nam))))
5589 = Base_Type (Etype (First_Formal (New_S))))
5591 Candidate_Renaming := Entity (Nam);
5595 Get_First_Interp (Nam, Ind, It);
5596 while Present (It.Nam) loop
5597 if Entity_Matches_Spec (It.Nam, New_S)
5598 and then Is_Visible_Operation (It.Nam)
5600 if Old_S /= Any_Id then
5602 -- Note: The call to Disambiguate only happens if a
5603 -- previous interpretation was found, in which case I1
5604 -- has received a value.
5606 It1 := Disambiguate (Nam, I1, Ind, Etype (Old_S));
5608 if It1 = No_Interp then
5609 Inst := Enclosing_Instance;
5611 if Present (Inst) then
5612 if Within (It.Nam, Inst) then
5613 if Within (Old_S, Inst) then
5615 -- Choose the innermost subprogram, which would
5616 -- have hidden the outer one in the generic.
5618 if Scope_Depth (It.Nam) <
5627 elsif Within (Old_S, Inst) then
5631 return Report_Overload;
5634 -- If not within an instance, ambiguity is real
5637 return Report_Overload;
5651 Present (First_Formal (It.Nam))
5652 and then Present (First_Formal (New_S))
5653 and then (Base_Type (Etype (First_Formal (It.Nam)))
5654 = Base_Type (Etype (First_Formal (New_S))))
5656 Candidate_Renaming := It.Nam;
5659 Get_Next_Interp (Ind, It);
5662 Set_Entity (Nam, Old_S);
5664 if Old_S /= Any_Id then
5665 Set_Is_Overloaded (Nam, False);
5670 end Find_Renamed_Entity;
5672 -----------------------------
5673 -- Find_Selected_Component --
5674 -----------------------------
5676 procedure Find_Selected_Component (N : Node_Id) is
5677 P : constant Node_Id := Prefix (N);
5680 -- Entity denoted by prefix
5690 if Nkind (P) = N_Error then
5694 -- Selector name cannot be a character literal or an operator symbol in
5695 -- SPARK, except for the operator symbol in a renaming.
5697 if Restriction_Check_Required (SPARK) then
5698 if Nkind (Selector_Name (N)) = N_Character_Literal then
5699 Check_SPARK_Restriction
5700 ("character literal cannot be prefixed", N);
5701 elsif Nkind (Selector_Name (N)) = N_Operator_Symbol
5702 and then Nkind (Parent (N)) /= N_Subprogram_Renaming_Declaration
5704 Check_SPARK_Restriction ("operator symbol cannot be prefixed", N);
5708 -- If the selector already has an entity, the node has been constructed
5709 -- in the course of expansion, and is known to be valid. Do not verify
5710 -- that it is defined for the type (it may be a private component used
5711 -- in the expansion of record equality).
5713 if Present (Entity (Selector_Name (N))) then
5715 or else Etype (N) = Any_Type
5718 Sel_Name : constant Node_Id := Selector_Name (N);
5719 Selector : constant Entity_Id := Entity (Sel_Name);
5723 Set_Etype (Sel_Name, Etype (Selector));
5725 if not Is_Entity_Name (P) then
5729 -- Build an actual subtype except for the first parameter
5730 -- of an init proc, where this actual subtype is by
5731 -- definition incorrect, since the object is uninitialized
5732 -- (and does not even have defined discriminants etc.)
5734 if Is_Entity_Name (P)
5735 and then Ekind (Entity (P)) = E_Function
5737 Nam := New_Copy (P);
5739 if Is_Overloaded (P) then
5740 Save_Interps (P, Nam);
5744 Make_Function_Call (Sloc (P), Name => Nam));
5746 Analyze_Selected_Component (N);
5749 elsif Ekind (Selector) = E_Component
5750 and then (not Is_Entity_Name (P)
5751 or else Chars (Entity (P)) /= Name_uInit)
5753 -- Do not build the subtype when referencing components of
5754 -- dispatch table wrappers. Required to avoid generating
5755 -- elaboration code with HI runtimes. JVM and .NET use a
5756 -- modified version of Ada.Tags which does not contain RE_
5757 -- Dispatch_Table_Wrapper and RE_No_Dispatch_Table_Wrapper.
5758 -- Avoid raising RE_Not_Available exception in those cases.
5760 if VM_Target = No_VM
5761 and then RTU_Loaded (Ada_Tags)
5763 ((RTE_Available (RE_Dispatch_Table_Wrapper)
5764 and then Scope (Selector) =
5765 RTE (RE_Dispatch_Table_Wrapper))
5767 (RTE_Available (RE_No_Dispatch_Table_Wrapper)
5768 and then Scope (Selector) =
5769 RTE (RE_No_Dispatch_Table_Wrapper)))
5775 Build_Actual_Subtype_Of_Component
5776 (Etype (Selector), N);
5783 if No (C_Etype) then
5784 C_Etype := Etype (Selector);
5786 Insert_Action (N, C_Etype);
5787 C_Etype := Defining_Identifier (C_Etype);
5790 Set_Etype (N, C_Etype);
5793 -- If this is the name of an entry or protected operation, and
5794 -- the prefix is an access type, insert an explicit dereference,
5795 -- so that entry calls are treated uniformly.
5797 if Is_Access_Type (Etype (P))
5798 and then Is_Concurrent_Type (Designated_Type (Etype (P)))
5801 New_P : constant Node_Id :=
5802 Make_Explicit_Dereference (Sloc (P),
5803 Prefix => Relocate_Node (P));
5806 Set_Etype (P, Designated_Type (Etype (Prefix (P))));
5810 -- If the selected component appears within a default expression
5811 -- and it has an actual subtype, the pre-analysis has not yet
5812 -- completed its analysis, because Insert_Actions is disabled in
5813 -- that context. Within the init proc of the enclosing type we
5814 -- must complete this analysis, if an actual subtype was created.
5816 elsif Inside_Init_Proc then
5818 Typ : constant Entity_Id := Etype (N);
5819 Decl : constant Node_Id := Declaration_Node (Typ);
5821 if Nkind (Decl) = N_Subtype_Declaration
5822 and then not Analyzed (Decl)
5823 and then Is_List_Member (Decl)
5824 and then No (Parent (Decl))
5827 Insert_Action (N, Decl);
5834 elsif Is_Entity_Name (P) then
5835 P_Name := Entity (P);
5837 -- The prefix may denote an enclosing type which is the completion
5838 -- of an incomplete type declaration.
5840 if Is_Type (P_Name) then
5841 Set_Entity (P, Get_Full_View (P_Name));
5842 Set_Etype (P, Entity (P));
5843 P_Name := Entity (P);
5846 P_Type := Base_Type (Etype (P));
5848 if Debug_Flag_E then
5849 Write_Str ("Found prefix type to be ");
5850 Write_Entity_Info (P_Type, " "); Write_Eol;
5853 -- First check for components of a record object (not the
5854 -- result of a call, which is handled below).
5856 if Is_Appropriate_For_Record (P_Type)
5857 and then not Is_Overloadable (P_Name)
5858 and then not Is_Type (P_Name)
5860 -- Selected component of record. Type checking will validate
5861 -- name of selector.
5862 -- ??? could we rewrite an implicit dereference into an explicit
5865 Analyze_Selected_Component (N);
5867 -- Reference to type name in predicate/invariant expression
5869 elsif Is_Appropriate_For_Entry_Prefix (P_Type)
5870 and then not In_Open_Scopes (P_Name)
5871 and then (not Is_Concurrent_Type (Etype (P_Name))
5872 or else not In_Open_Scopes (Etype (P_Name)))
5874 -- Call to protected operation or entry. Type checking is
5875 -- needed on the prefix.
5877 Analyze_Selected_Component (N);
5879 elsif (In_Open_Scopes (P_Name)
5880 and then Ekind (P_Name) /= E_Void
5881 and then not Is_Overloadable (P_Name))
5882 or else (Is_Concurrent_Type (Etype (P_Name))
5883 and then In_Open_Scopes (Etype (P_Name)))
5885 -- Prefix denotes an enclosing loop, block, or task, i.e. an
5886 -- enclosing construct that is not a subprogram or accept.
5888 Find_Expanded_Name (N);
5890 elsif Ekind (P_Name) = E_Package then
5891 Find_Expanded_Name (N);
5893 elsif Is_Overloadable (P_Name) then
5895 -- The subprogram may be a renaming (of an enclosing scope) as
5896 -- in the case of the name of the generic within an instantiation.
5898 if Ekind_In (P_Name, E_Procedure, E_Function)
5899 and then Present (Alias (P_Name))
5900 and then Is_Generic_Instance (Alias (P_Name))
5902 P_Name := Alias (P_Name);
5905 if Is_Overloaded (P) then
5907 -- The prefix must resolve to a unique enclosing construct
5910 Found : Boolean := False;
5915 Get_First_Interp (P, Ind, It);
5916 while Present (It.Nam) loop
5917 if In_Open_Scopes (It.Nam) then
5920 "prefix must be unique enclosing scope", N);
5921 Set_Entity (N, Any_Id);
5922 Set_Etype (N, Any_Type);
5931 Get_Next_Interp (Ind, It);
5936 if In_Open_Scopes (P_Name) then
5937 Set_Entity (P, P_Name);
5938 Set_Is_Overloaded (P, False);
5939 Find_Expanded_Name (N);
5942 -- If no interpretation as an expanded name is possible, it
5943 -- must be a selected component of a record returned by a
5944 -- function call. Reformat prefix as a function call, the rest
5945 -- is done by type resolution. If the prefix is procedure or
5946 -- entry, as is P.X; this is an error.
5948 if Ekind (P_Name) /= E_Function
5949 and then (not Is_Overloaded (P)
5951 Nkind (Parent (N)) = N_Procedure_Call_Statement)
5953 -- Prefix may mention a package that is hidden by a local
5954 -- declaration: let the user know. Scan the full homonym
5955 -- chain, the candidate package may be anywhere on it.
5957 if Present (Homonym (Current_Entity (P_Name))) then
5959 P_Name := Current_Entity (P_Name);
5961 while Present (P_Name) loop
5962 exit when Ekind (P_Name) = E_Package;
5963 P_Name := Homonym (P_Name);
5966 if Present (P_Name) then
5967 Error_Msg_Sloc := Sloc (Entity (Prefix (N)));
5970 ("package& is hidden by declaration#",
5973 Set_Entity (Prefix (N), P_Name);
5974 Find_Expanded_Name (N);
5977 P_Name := Entity (Prefix (N));
5982 ("invalid prefix in selected component&", N, P_Name);
5983 Change_Selected_Component_To_Expanded_Name (N);
5984 Set_Entity (N, Any_Id);
5985 Set_Etype (N, Any_Type);
5988 Nam := New_Copy (P);
5989 Save_Interps (P, Nam);
5991 Make_Function_Call (Sloc (P), Name => Nam));
5993 Analyze_Selected_Component (N);
5997 -- Remaining cases generate various error messages
6000 -- Format node as expanded name, to avoid cascaded errors
6002 Change_Selected_Component_To_Expanded_Name (N);
6003 Set_Entity (N, Any_Id);
6004 Set_Etype (N, Any_Type);
6006 -- Issue error message, but avoid this if error issued already.
6007 -- Use identifier of prefix if one is available.
6009 if P_Name = Any_Id then
6012 elsif Ekind (P_Name) = E_Void then
6013 Premature_Usage (P);
6015 elsif Nkind (P) /= N_Attribute_Reference then
6017 "invalid prefix in selected component&", P);
6019 if Is_Access_Type (P_Type)
6020 and then Ekind (Designated_Type (P_Type)) = E_Incomplete_Type
6023 ("\dereference must not be of an incomplete type " &
6029 "invalid prefix in selected component", P);
6033 -- Selector name is restricted in SPARK
6035 if Nkind (N) = N_Expanded_Name
6036 and then Restriction_Check_Required (SPARK)
6038 if Is_Subprogram (P_Name) then
6039 Check_SPARK_Restriction
6040 ("prefix of expanded name cannot be a subprogram", P);
6041 elsif Ekind (P_Name) = E_Loop then
6042 Check_SPARK_Restriction
6043 ("prefix of expanded name cannot be a loop statement", P);
6048 -- If prefix is not the name of an entity, it must be an expression,
6049 -- whose type is appropriate for a record. This is determined by
6052 Analyze_Selected_Component (N);
6054 end Find_Selected_Component;
6060 procedure Find_Type (N : Node_Id) is
6070 elsif Nkind (N) = N_Attribute_Reference then
6072 -- Class attribute. This is not valid in Ada 83 mode, but we do not
6073 -- need to enforce that at this point, since the declaration of the
6074 -- tagged type in the prefix would have been flagged already.
6076 if Attribute_Name (N) = Name_Class then
6077 Check_Restriction (No_Dispatch, N);
6078 Find_Type (Prefix (N));
6080 -- Propagate error from bad prefix
6082 if Etype (Prefix (N)) = Any_Type then
6083 Set_Entity (N, Any_Type);
6084 Set_Etype (N, Any_Type);
6088 T := Base_Type (Entity (Prefix (N)));
6090 -- Case where type is not known to be tagged. Its appearance in
6091 -- the prefix of the 'Class attribute indicates that the full view
6094 if not Is_Tagged_Type (T) then
6095 if Ekind (T) = E_Incomplete_Type then
6097 -- It is legal to denote the class type of an incomplete
6098 -- type. The full type will have to be tagged, of course.
6099 -- In Ada 2005 this usage is declared obsolescent, so we
6100 -- warn accordingly. This usage is only legal if the type
6101 -- is completed in the current scope, and not for a limited
6104 if not Is_Tagged_Type (T)
6105 and then Ada_Version >= Ada_2005
6107 if From_With_Type (T) then
6109 ("prefix of Class attribute must be tagged", N);
6110 Set_Etype (N, Any_Type);
6111 Set_Entity (N, Any_Type);
6114 -- ??? This test is temporarily disabled (always False)
6115 -- because it causes an unwanted warning on GNAT sources
6116 -- (built with -gnatg, which includes Warn_On_Obsolescent_
6117 -- Feature). Once this issue is cleared in the sources, it
6120 elsif Warn_On_Obsolescent_Feature
6124 ("applying 'Class to an untagged incomplete type"
6125 & " is an obsolescent feature (RM J.11)", N);
6129 Set_Is_Tagged_Type (T);
6130 Set_Direct_Primitive_Operations (T, New_Elmt_List);
6131 Make_Class_Wide_Type (T);
6132 Set_Entity (N, Class_Wide_Type (T));
6133 Set_Etype (N, Class_Wide_Type (T));
6135 elsif Ekind (T) = E_Private_Type
6136 and then not Is_Generic_Type (T)
6137 and then In_Private_Part (Scope (T))
6139 -- The Class attribute can be applied to an untagged private
6140 -- type fulfilled by a tagged type prior to the full type
6141 -- declaration (but only within the parent package's private
6142 -- part). Create the class-wide type now and check that the
6143 -- full type is tagged later during its analysis. Note that
6144 -- we do not mark the private type as tagged, unlike the
6145 -- case of incomplete types, because the type must still
6146 -- appear untagged to outside units.
6148 if No (Class_Wide_Type (T)) then
6149 Make_Class_Wide_Type (T);
6152 Set_Entity (N, Class_Wide_Type (T));
6153 Set_Etype (N, Class_Wide_Type (T));
6156 -- Should we introduce a type Any_Tagged and use Wrong_Type
6157 -- here, it would be a bit more consistent???
6160 ("tagged type required, found}",
6161 Prefix (N), First_Subtype (T));
6162 Set_Entity (N, Any_Type);
6166 -- Case of tagged type
6169 if Is_Concurrent_Type (T) then
6170 if No (Corresponding_Record_Type (Entity (Prefix (N)))) then
6172 -- Previous error. Use current type, which at least
6173 -- provides some operations.
6175 C := Entity (Prefix (N));
6178 C := Class_Wide_Type
6179 (Corresponding_Record_Type (Entity (Prefix (N))));
6183 C := Class_Wide_Type (Entity (Prefix (N)));
6186 Set_Entity_With_Style_Check (N, C);
6187 Generate_Reference (C, N);
6191 -- Base attribute, not allowed in Ada 83
6193 elsif Attribute_Name (N) = Name_Base then
6194 Error_Msg_Name_1 := Name_Base;
6195 Check_SPARK_Restriction
6196 ("attribute% is only allowed as prefix of another attribute", N);
6198 if Ada_Version = Ada_83 and then Comes_From_Source (N) then
6200 ("(Ada 83) Base attribute not allowed in subtype mark", N);
6203 Find_Type (Prefix (N));
6204 Typ := Entity (Prefix (N));
6206 if Ada_Version >= Ada_95
6207 and then not Is_Scalar_Type (Typ)
6208 and then not Is_Generic_Type (Typ)
6211 ("prefix of Base attribute must be scalar type",
6214 elsif Warn_On_Redundant_Constructs
6215 and then Base_Type (Typ) = Typ
6217 Error_Msg_NE -- CODEFIX
6218 ("?redundant attribute, & is its own base type", N, Typ);
6221 T := Base_Type (Typ);
6223 -- Rewrite attribute reference with type itself (see similar
6224 -- processing in Analyze_Attribute, case Base). Preserve prefix
6225 -- if present, for other legality checks.
6227 if Nkind (Prefix (N)) = N_Expanded_Name then
6229 Make_Expanded_Name (Sloc (N),
6231 Prefix => New_Copy (Prefix (Prefix (N))),
6232 Selector_Name => New_Reference_To (T, Sloc (N))));
6235 Rewrite (N, New_Reference_To (T, Sloc (N)));
6242 elsif Attribute_Name (N) = Name_Stub_Type then
6244 -- This is handled in Analyze_Attribute
6248 -- All other attributes are invalid in a subtype mark
6251 Error_Msg_N ("invalid attribute in subtype mark", N);
6257 if Is_Entity_Name (N) then
6258 T_Name := Entity (N);
6260 Error_Msg_N ("subtype mark required in this context", N);
6261 Set_Etype (N, Any_Type);
6265 if T_Name = Any_Id or else Etype (N) = Any_Type then
6267 -- Undefined id. Make it into a valid type
6269 Set_Entity (N, Any_Type);
6271 elsif not Is_Type (T_Name)
6272 and then T_Name /= Standard_Void_Type
6274 Error_Msg_Sloc := Sloc (T_Name);
6275 Error_Msg_N ("subtype mark required in this context", N);
6276 Error_Msg_NE ("\\found & declared#", N, T_Name);
6277 Set_Entity (N, Any_Type);
6280 -- If the type is an incomplete type created to handle
6281 -- anonymous access components of a record type, then the
6282 -- incomplete type is the visible entity and subsequent
6283 -- references will point to it. Mark the original full
6284 -- type as referenced, to prevent spurious warnings.
6286 if Is_Incomplete_Type (T_Name)
6287 and then Present (Full_View (T_Name))
6288 and then not Comes_From_Source (T_Name)
6290 Set_Referenced (Full_View (T_Name));
6293 T_Name := Get_Full_View (T_Name);
6295 -- Ada 2005 (AI-251, AI-50217): Handle interfaces visible through
6296 -- limited-with clauses
6298 if From_With_Type (T_Name)
6299 and then Ekind (T_Name) in Incomplete_Kind
6300 and then Present (Non_Limited_View (T_Name))
6301 and then Is_Interface (Non_Limited_View (T_Name))
6303 T_Name := Non_Limited_View (T_Name);
6306 if In_Open_Scopes (T_Name) then
6307 if Ekind (Base_Type (T_Name)) = E_Task_Type then
6309 -- In Ada 2005, a task name can be used in an access
6310 -- definition within its own body. It cannot be used
6311 -- in the discriminant part of the task declaration,
6312 -- nor anywhere else in the declaration because entries
6313 -- cannot have access parameters.
6315 if Ada_Version >= Ada_2005
6316 and then Nkind (Parent (N)) = N_Access_Definition
6318 Set_Entity (N, T_Name);
6319 Set_Etype (N, T_Name);
6321 if Has_Completion (T_Name) then
6326 ("task type cannot be used as type mark " &
6327 "within its own declaration", N);
6332 ("task type cannot be used as type mark " &
6333 "within its own spec or body", N);
6336 elsif Ekind (Base_Type (T_Name)) = E_Protected_Type then
6338 -- In Ada 2005, a protected name can be used in an access
6339 -- definition within its own body.
6341 if Ada_Version >= Ada_2005
6342 and then Nkind (Parent (N)) = N_Access_Definition
6344 Set_Entity (N, T_Name);
6345 Set_Etype (N, T_Name);
6350 ("protected type cannot be used as type mark " &
6351 "within its own spec or body", N);
6355 Error_Msg_N ("type declaration cannot refer to itself", N);
6358 Set_Etype (N, Any_Type);
6359 Set_Entity (N, Any_Type);
6360 Set_Error_Posted (T_Name);
6364 Set_Entity (N, T_Name);
6365 Set_Etype (N, T_Name);
6369 if Present (Etype (N)) and then Comes_From_Source (N) then
6370 if Is_Fixed_Point_Type (Etype (N)) then
6371 Check_Restriction (No_Fixed_Point, N);
6372 elsif Is_Floating_Point_Type (Etype (N)) then
6373 Check_Restriction (No_Floating_Point, N);
6378 ------------------------------------
6379 -- Has_Implicit_Character_Literal --
6380 ------------------------------------
6382 function Has_Implicit_Character_Literal (N : Node_Id) return Boolean is
6384 Found : Boolean := False;
6385 P : constant Entity_Id := Entity (Prefix (N));
6386 Priv_Id : Entity_Id := Empty;
6389 if Ekind (P) = E_Package
6390 and then not In_Open_Scopes (P)
6392 Priv_Id := First_Private_Entity (P);
6395 if P = Standard_Standard then
6396 Change_Selected_Component_To_Expanded_Name (N);
6397 Rewrite (N, Selector_Name (N));
6399 Set_Etype (Original_Node (N), Standard_Character);
6403 Id := First_Entity (P);
6405 and then Id /= Priv_Id
6407 if Is_Standard_Character_Type (Id) and then Is_Base_Type (Id) then
6409 -- We replace the node with the literal itself, resolve as a
6410 -- character, and set the type correctly.
6413 Change_Selected_Component_To_Expanded_Name (N);
6414 Rewrite (N, Selector_Name (N));
6417 Set_Etype (Original_Node (N), Id);
6421 -- More than one type derived from Character in given scope.
6422 -- Collect all possible interpretations.
6424 Add_One_Interp (N, Id, Id);
6432 end Has_Implicit_Character_Literal;
6434 ----------------------
6435 -- Has_Private_With --
6436 ----------------------
6438 function Has_Private_With (E : Entity_Id) return Boolean is
6439 Comp_Unit : constant Node_Id := Cunit (Current_Sem_Unit);
6443 Item := First (Context_Items (Comp_Unit));
6444 while Present (Item) loop
6445 if Nkind (Item) = N_With_Clause
6446 and then Private_Present (Item)
6447 and then Entity (Name (Item)) = E
6456 end Has_Private_With;
6458 ---------------------------
6459 -- Has_Implicit_Operator --
6460 ---------------------------
6462 function Has_Implicit_Operator (N : Node_Id) return Boolean is
6463 Op_Id : constant Name_Id := Chars (Selector_Name (N));
6464 P : constant Entity_Id := Entity (Prefix (N));
6466 Priv_Id : Entity_Id := Empty;
6468 procedure Add_Implicit_Operator
6470 Op_Type : Entity_Id := Empty);
6471 -- Add implicit interpretation to node N, using the type for which a
6472 -- predefined operator exists. If the operator yields a boolean type,
6473 -- the Operand_Type is implicitly referenced by the operator, and a
6474 -- reference to it must be generated.
6476 ---------------------------
6477 -- Add_Implicit_Operator --
6478 ---------------------------
6480 procedure Add_Implicit_Operator
6482 Op_Type : Entity_Id := Empty)
6484 Predef_Op : Entity_Id;
6487 Predef_Op := Current_Entity (Selector_Name (N));
6489 while Present (Predef_Op)
6490 and then Scope (Predef_Op) /= Standard_Standard
6492 Predef_Op := Homonym (Predef_Op);
6495 if Nkind (N) = N_Selected_Component then
6496 Change_Selected_Component_To_Expanded_Name (N);
6499 -- If the context is an unanalyzed function call, determine whether
6500 -- a binary or unary interpretation is required.
6502 if Nkind (Parent (N)) = N_Indexed_Component then
6504 Is_Binary_Call : constant Boolean :=
6506 (Next (First (Expressions (Parent (N)))));
6507 Is_Binary_Op : constant Boolean :=
6509 (Predef_Op) /= Last_Entity (Predef_Op);
6510 Predef_Op2 : constant Entity_Id := Homonym (Predef_Op);
6513 if Is_Binary_Call then
6514 if Is_Binary_Op then
6515 Add_One_Interp (N, Predef_Op, T);
6517 Add_One_Interp (N, Predef_Op2, T);
6521 if not Is_Binary_Op then
6522 Add_One_Interp (N, Predef_Op, T);
6524 Add_One_Interp (N, Predef_Op2, T);
6530 Add_One_Interp (N, Predef_Op, T);
6532 -- For operators with unary and binary interpretations, if
6533 -- context is not a call, add both
6535 if Present (Homonym (Predef_Op)) then
6536 Add_One_Interp (N, Homonym (Predef_Op), T);
6540 -- The node is a reference to a predefined operator, and
6541 -- an implicit reference to the type of its operands.
6543 if Present (Op_Type) then
6544 Generate_Operator_Reference (N, Op_Type);
6546 Generate_Operator_Reference (N, T);
6548 end Add_Implicit_Operator;
6550 -- Start of processing for Has_Implicit_Operator
6553 if Ekind (P) = E_Package
6554 and then not In_Open_Scopes (P)
6556 Priv_Id := First_Private_Entity (P);
6559 Id := First_Entity (P);
6563 -- Boolean operators: an implicit declaration exists if the scope
6564 -- contains a declaration for a derived Boolean type, or for an
6565 -- array of Boolean type.
6567 when Name_Op_And | Name_Op_Not | Name_Op_Or | Name_Op_Xor =>
6568 while Id /= Priv_Id loop
6569 if Valid_Boolean_Arg (Id) and then Is_Base_Type (Id) then
6570 Add_Implicit_Operator (Id);
6577 -- Equality: look for any non-limited type (result is Boolean)
6579 when Name_Op_Eq | Name_Op_Ne =>
6580 while Id /= Priv_Id loop
6582 and then not Is_Limited_Type (Id)
6583 and then Is_Base_Type (Id)
6585 Add_Implicit_Operator (Standard_Boolean, Id);
6592 -- Comparison operators: scalar type, or array of scalar
6594 when Name_Op_Lt | Name_Op_Le | Name_Op_Gt | Name_Op_Ge =>
6595 while Id /= Priv_Id loop
6596 if (Is_Scalar_Type (Id)
6597 or else (Is_Array_Type (Id)
6598 and then Is_Scalar_Type (Component_Type (Id))))
6599 and then Is_Base_Type (Id)
6601 Add_Implicit_Operator (Standard_Boolean, Id);
6608 -- Arithmetic operators: any numeric type
6618 while Id /= Priv_Id loop
6619 if Is_Numeric_Type (Id) and then Is_Base_Type (Id) then
6620 Add_Implicit_Operator (Id);
6627 -- Concatenation: any one-dimensional array type
6629 when Name_Op_Concat =>
6630 while Id /= Priv_Id loop
6631 if Is_Array_Type (Id)
6632 and then Number_Dimensions (Id) = 1
6633 and then Is_Base_Type (Id)
6635 Add_Implicit_Operator (Id);
6642 -- What is the others condition here? Should we be using a
6643 -- subtype of Name_Id that would restrict to operators ???
6645 when others => null;
6648 -- If we fall through, then we do not have an implicit operator
6652 end Has_Implicit_Operator;
6654 -----------------------------------
6655 -- Has_Loop_In_Inner_Open_Scopes --
6656 -----------------------------------
6658 function Has_Loop_In_Inner_Open_Scopes (S : Entity_Id) return Boolean is
6660 -- Several scope stacks are maintained by Scope_Stack. The base of the
6661 -- currently active scope stack is denoted by the Is_Active_Stack_Base
6662 -- flag in the scope stack entry. Note that the scope stacks used to
6663 -- simply be delimited implicitly by the presence of Standard_Standard
6664 -- at their base, but there now are cases where this is not sufficient
6665 -- because Standard_Standard actually may appear in the middle of the
6666 -- active set of scopes.
6668 for J in reverse 0 .. Scope_Stack.Last loop
6670 -- S was reached without seing a loop scope first
6672 if Scope_Stack.Table (J).Entity = S then
6675 -- S was not yet reached, so it contains at least one inner loop
6677 elsif Ekind (Scope_Stack.Table (J).Entity) = E_Loop then
6681 -- Check Is_Active_Stack_Base to tell us when to stop, as there are
6682 -- cases where Standard_Standard appears in the middle of the active
6683 -- set of scopes. This affects the declaration and overriding of
6684 -- private inherited operations in instantiations of generic child
6687 pragma Assert (not Scope_Stack.Table (J).Is_Active_Stack_Base);
6690 raise Program_Error; -- unreachable
6691 end Has_Loop_In_Inner_Open_Scopes;
6693 --------------------
6694 -- In_Open_Scopes --
6695 --------------------
6697 function In_Open_Scopes (S : Entity_Id) return Boolean is
6699 -- Several scope stacks are maintained by Scope_Stack. The base of the
6700 -- currently active scope stack is denoted by the Is_Active_Stack_Base
6701 -- flag in the scope stack entry. Note that the scope stacks used to
6702 -- simply be delimited implicitly by the presence of Standard_Standard
6703 -- at their base, but there now are cases where this is not sufficient
6704 -- because Standard_Standard actually may appear in the middle of the
6705 -- active set of scopes.
6707 for J in reverse 0 .. Scope_Stack.Last loop
6708 if Scope_Stack.Table (J).Entity = S then
6712 -- Check Is_Active_Stack_Base to tell us when to stop, as there are
6713 -- cases where Standard_Standard appears in the middle of the active
6714 -- set of scopes. This affects the declaration and overriding of
6715 -- private inherited operations in instantiations of generic child
6718 exit when Scope_Stack.Table (J).Is_Active_Stack_Base;
6724 -----------------------------
6725 -- Inherit_Renamed_Profile --
6726 -----------------------------
6728 procedure Inherit_Renamed_Profile (New_S : Entity_Id; Old_S : Entity_Id) is
6735 if Ekind (Old_S) = E_Operator then
6736 New_F := First_Formal (New_S);
6738 while Present (New_F) loop
6739 Set_Etype (New_F, Base_Type (Etype (New_F)));
6740 Next_Formal (New_F);
6743 Set_Etype (New_S, Base_Type (Etype (New_S)));
6746 New_F := First_Formal (New_S);
6747 Old_F := First_Formal (Old_S);
6749 while Present (New_F) loop
6750 New_T := Etype (New_F);
6751 Old_T := Etype (Old_F);
6753 -- If the new type is a renaming of the old one, as is the
6754 -- case for actuals in instances, retain its name, to simplify
6755 -- later disambiguation.
6757 if Nkind (Parent (New_T)) = N_Subtype_Declaration
6758 and then Is_Entity_Name (Subtype_Indication (Parent (New_T)))
6759 and then Entity (Subtype_Indication (Parent (New_T))) = Old_T
6763 Set_Etype (New_F, Old_T);
6766 Next_Formal (New_F);
6767 Next_Formal (Old_F);
6770 if Ekind_In (Old_S, E_Function, E_Enumeration_Literal) then
6771 Set_Etype (New_S, Etype (Old_S));
6774 end Inherit_Renamed_Profile;
6780 procedure Initialize is
6785 -------------------------
6786 -- Install_Use_Clauses --
6787 -------------------------
6789 procedure Install_Use_Clauses
6791 Force_Installation : Boolean := False)
6799 while Present (U) loop
6801 -- Case of USE package
6803 if Nkind (U) = N_Use_Package_Clause then
6804 P := First (Names (U));
6805 while Present (P) loop
6808 if Ekind (Id) = E_Package then
6810 Note_Redundant_Use (P);
6812 elsif Present (Renamed_Object (Id))
6813 and then In_Use (Renamed_Object (Id))
6815 Note_Redundant_Use (P);
6817 elsif Force_Installation or else Applicable_Use (P) then
6818 Use_One_Package (Id, U);
6829 P := First (Subtype_Marks (U));
6830 while Present (P) loop
6831 if not Is_Entity_Name (P)
6832 or else No (Entity (P))
6836 elsif Entity (P) /= Any_Type then
6844 Next_Use_Clause (U);
6846 end Install_Use_Clauses;
6848 -------------------------------------
6849 -- Is_Appropriate_For_Entry_Prefix --
6850 -------------------------------------
6852 function Is_Appropriate_For_Entry_Prefix (T : Entity_Id) return Boolean is
6853 P_Type : Entity_Id := T;
6856 if Is_Access_Type (P_Type) then
6857 P_Type := Designated_Type (P_Type);
6860 return Is_Task_Type (P_Type) or else Is_Protected_Type (P_Type);
6861 end Is_Appropriate_For_Entry_Prefix;
6863 -------------------------------
6864 -- Is_Appropriate_For_Record --
6865 -------------------------------
6867 function Is_Appropriate_For_Record (T : Entity_Id) return Boolean is
6869 function Has_Components (T1 : Entity_Id) return Boolean;
6870 -- Determine if given type has components (i.e. is either a record
6871 -- type or a type that has discriminants).
6873 --------------------
6874 -- Has_Components --
6875 --------------------
6877 function Has_Components (T1 : Entity_Id) return Boolean is
6879 return Is_Record_Type (T1)
6880 or else (Is_Private_Type (T1) and then Has_Discriminants (T1))
6881 or else (Is_Task_Type (T1) and then Has_Discriminants (T1))
6882 or else (Is_Incomplete_Type (T1)
6883 and then From_With_Type (T1)
6884 and then Present (Non_Limited_View (T1))
6885 and then Is_Record_Type
6886 (Get_Full_View (Non_Limited_View (T1))));
6889 -- Start of processing for Is_Appropriate_For_Record
6894 and then (Has_Components (T)
6895 or else (Is_Access_Type (T)
6896 and then Has_Components (Designated_Type (T))));
6897 end Is_Appropriate_For_Record;
6899 ------------------------
6900 -- Note_Redundant_Use --
6901 ------------------------
6903 procedure Note_Redundant_Use (Clause : Node_Id) is
6904 Pack_Name : constant Entity_Id := Entity (Clause);
6905 Cur_Use : constant Node_Id := Current_Use_Clause (Pack_Name);
6906 Decl : constant Node_Id := Parent (Clause);
6908 Prev_Use : Node_Id := Empty;
6909 Redundant : Node_Id := Empty;
6910 -- The Use_Clause which is actually redundant. In the simplest case it
6911 -- is Pack itself, but when we compile a body we install its context
6912 -- before that of its spec, in which case it is the use_clause in the
6913 -- spec that will appear to be redundant, and we want the warning to be
6914 -- placed on the body. Similar complications appear when the redundancy
6915 -- is between a child unit and one of its ancestors.
6918 Set_Redundant_Use (Clause, True);
6920 if not Comes_From_Source (Clause)
6922 or else not Warn_On_Redundant_Constructs
6927 if not Is_Compilation_Unit (Current_Scope) then
6929 -- If the use_clause is in an inner scope, it is made redundant by
6930 -- some clause in the current context, with one exception: If we're
6931 -- compiling a nested package body, and the use_clause comes from the
6932 -- corresponding spec, the clause is not necessarily fully redundant,
6933 -- so we should not warn. If a warning was warranted, it would have
6934 -- been given when the spec was processed.
6936 if Nkind (Parent (Decl)) = N_Package_Specification then
6938 Package_Spec_Entity : constant Entity_Id :=
6939 Defining_Unit_Name (Parent (Decl));
6941 if In_Package_Body (Package_Spec_Entity) then
6947 Redundant := Clause;
6948 Prev_Use := Cur_Use;
6950 elsif Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Body then
6952 Cur_Unit : constant Unit_Number_Type := Get_Source_Unit (Cur_Use);
6953 New_Unit : constant Unit_Number_Type := Get_Source_Unit (Clause);
6957 if Cur_Unit = New_Unit then
6959 -- Redundant clause in same body
6961 Redundant := Clause;
6962 Prev_Use := Cur_Use;
6964 elsif Cur_Unit = Current_Sem_Unit then
6966 -- If the new clause is not in the current unit it has been
6967 -- analyzed first, and it makes the other one redundant.
6968 -- However, if the new clause appears in a subunit, Cur_Unit
6969 -- is still the parent, and in that case the redundant one
6970 -- is the one appearing in the subunit.
6972 if Nkind (Unit (Cunit (New_Unit))) = N_Subunit then
6973 Redundant := Clause;
6974 Prev_Use := Cur_Use;
6976 -- Most common case: redundant clause in body,
6977 -- original clause in spec. Current scope is spec entity.
6982 Unit (Library_Unit (Cunit (Current_Sem_Unit))))
6984 Redundant := Cur_Use;
6988 -- The new clause may appear in an unrelated unit, when
6989 -- the parents of a generic are being installed prior to
6990 -- instantiation. In this case there must be no warning.
6991 -- We detect this case by checking whether the current top
6992 -- of the stack is related to the current compilation.
6994 Scop := Current_Scope;
6995 while Present (Scop)
6996 and then Scop /= Standard_Standard
6998 if Is_Compilation_Unit (Scop)
6999 and then not Is_Child_Unit (Scop)
7003 elsif Scop = Cunit_Entity (Current_Sem_Unit) then
7007 Scop := Scope (Scop);
7010 Redundant := Cur_Use;
7014 elsif New_Unit = Current_Sem_Unit then
7015 Redundant := Clause;
7016 Prev_Use := Cur_Use;
7019 -- Neither is the current unit, so they appear in parent or
7020 -- sibling units. Warning will be emitted elsewhere.
7026 elsif Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Declaration
7027 and then Present (Parent_Spec (Unit (Cunit (Current_Sem_Unit))))
7029 -- Use_clause is in child unit of current unit, and the child unit
7030 -- appears in the context of the body of the parent, so it has been
7031 -- installed first, even though it is the redundant one. Depending on
7032 -- their placement in the context, the visible or the private parts
7033 -- of the two units, either might appear as redundant, but the
7034 -- message has to be on the current unit.
7036 if Get_Source_Unit (Cur_Use) = Current_Sem_Unit then
7037 Redundant := Cur_Use;
7040 Redundant := Clause;
7041 Prev_Use := Cur_Use;
7044 -- If the new use clause appears in the private part of a parent unit
7045 -- it may appear to be redundant w.r.t. a use clause in a child unit,
7046 -- but the previous use clause was needed in the visible part of the
7047 -- child, and no warning should be emitted.
7049 if Nkind (Parent (Decl)) = N_Package_Specification
7051 List_Containing (Decl) = Private_Declarations (Parent (Decl))
7054 Par : constant Entity_Id := Defining_Entity (Parent (Decl));
7055 Spec : constant Node_Id :=
7056 Specification (Unit (Cunit (Current_Sem_Unit)));
7059 if Is_Compilation_Unit (Par)
7060 and then Par /= Cunit_Entity (Current_Sem_Unit)
7061 and then Parent (Cur_Use) = Spec
7063 List_Containing (Cur_Use) = Visible_Declarations (Spec)
7070 -- Finally, if the current use clause is in the context then
7071 -- the clause is redundant when it is nested within the unit.
7073 elsif Nkind (Parent (Cur_Use)) = N_Compilation_Unit
7074 and then Nkind (Parent (Parent (Clause))) /= N_Compilation_Unit
7075 and then Get_Source_Unit (Cur_Use) = Get_Source_Unit (Clause)
7077 Redundant := Clause;
7078 Prev_Use := Cur_Use;
7084 if Present (Redundant) then
7085 Error_Msg_Sloc := Sloc (Prev_Use);
7086 Error_Msg_NE -- CODEFIX
7087 ("& is already use-visible through previous use clause #?",
7088 Redundant, Pack_Name);
7090 end Note_Redundant_Use;
7096 procedure Pop_Scope is
7097 SST : Scope_Stack_Entry renames Scope_Stack.Table (Scope_Stack.Last);
7098 S : constant Entity_Id := SST.Entity;
7101 if Debug_Flag_E then
7105 -- Set Default_Storage_Pool field of the library unit if necessary
7107 if Ekind_In (S, E_Package, E_Generic_Package)
7109 Nkind (Parent (Unit_Declaration_Node (S))) = N_Compilation_Unit
7112 Aux : constant Node_Id :=
7113 Aux_Decls_Node (Parent (Unit_Declaration_Node (S)));
7115 if No (Default_Storage_Pool (Aux)) then
7116 Set_Default_Storage_Pool (Aux, Default_Pool);
7121 Scope_Suppress := SST.Save_Scope_Suppress;
7122 Local_Suppress_Stack_Top := SST.Save_Local_Suppress_Stack_Top;
7123 Check_Policy_List := SST.Save_Check_Policy_List;
7124 Default_Pool := SST.Save_Default_Storage_Pool;
7126 if Debug_Flag_W then
7127 Write_Str ("<-- exiting scope: ");
7128 Write_Name (Chars (Current_Scope));
7129 Write_Str (", Depth=");
7130 Write_Int (Int (Scope_Stack.Last));
7134 End_Use_Clauses (SST.First_Use_Clause);
7136 -- If the actions to be wrapped are still there they will get lost
7137 -- causing incomplete code to be generated. It is better to abort in
7138 -- this case (and we do the abort even with assertions off since the
7139 -- penalty is incorrect code generation)
7141 if SST.Actions_To_Be_Wrapped_Before /= No_List
7143 SST.Actions_To_Be_Wrapped_After /= No_List
7145 raise Program_Error;
7148 -- Free last subprogram name if allocated, and pop scope
7150 Free (SST.Last_Subprogram_Name);
7151 Scope_Stack.Decrement_Last;
7158 procedure Push_Scope (S : Entity_Id) is
7159 E : constant Entity_Id := Scope (S);
7162 if Ekind (S) = E_Void then
7165 -- Set scope depth if not a non-concurrent type, and we have not yet set
7166 -- the scope depth. This means that we have the first occurrence of the
7167 -- scope, and this is where the depth is set.
7169 elsif (not Is_Type (S) or else Is_Concurrent_Type (S))
7170 and then not Scope_Depth_Set (S)
7172 if S = Standard_Standard then
7173 Set_Scope_Depth_Value (S, Uint_0);
7175 elsif Is_Child_Unit (S) then
7176 Set_Scope_Depth_Value (S, Uint_1);
7178 elsif not Is_Record_Type (Current_Scope) then
7179 if Ekind (S) = E_Loop then
7180 Set_Scope_Depth_Value (S, Scope_Depth (Current_Scope));
7182 Set_Scope_Depth_Value (S, Scope_Depth (Current_Scope) + 1);
7187 Scope_Stack.Increment_Last;
7190 SST : Scope_Stack_Entry renames Scope_Stack.Table (Scope_Stack.Last);
7194 SST.Save_Scope_Suppress := Scope_Suppress;
7195 SST.Save_Local_Suppress_Stack_Top := Local_Suppress_Stack_Top;
7196 SST.Save_Check_Policy_List := Check_Policy_List;
7197 SST.Save_Default_Storage_Pool := Default_Pool;
7199 if Scope_Stack.Last > Scope_Stack.First then
7200 SST.Component_Alignment_Default := Scope_Stack.Table
7201 (Scope_Stack.Last - 1).
7202 Component_Alignment_Default;
7205 SST.Last_Subprogram_Name := null;
7206 SST.Is_Transient := False;
7207 SST.Node_To_Be_Wrapped := Empty;
7208 SST.Pending_Freeze_Actions := No_List;
7209 SST.Actions_To_Be_Wrapped_Before := No_List;
7210 SST.Actions_To_Be_Wrapped_After := No_List;
7211 SST.First_Use_Clause := Empty;
7212 SST.Is_Active_Stack_Base := False;
7213 SST.Previous_Visibility := False;
7216 if Debug_Flag_W then
7217 Write_Str ("--> new scope: ");
7218 Write_Name (Chars (Current_Scope));
7219 Write_Str (", Id=");
7220 Write_Int (Int (Current_Scope));
7221 Write_Str (", Depth=");
7222 Write_Int (Int (Scope_Stack.Last));
7226 -- Deal with copying flags from the previous scope to this one. This is
7227 -- not necessary if either scope is standard, or if the new scope is a
7230 if S /= Standard_Standard
7231 and then Scope (S) /= Standard_Standard
7232 and then not Is_Child_Unit (S)
7234 if Nkind (E) not in N_Entity then
7238 -- Copy categorization flags from Scope (S) to S, this is not done
7239 -- when Scope (S) is Standard_Standard since propagation is from
7240 -- library unit entity inwards. Copy other relevant attributes as
7241 -- well (Discard_Names in particular).
7243 -- We only propagate inwards for library level entities,
7244 -- inner level subprograms do not inherit the categorization.
7246 if Is_Library_Level_Entity (S) then
7247 Set_Is_Preelaborated (S, Is_Preelaborated (E));
7248 Set_Is_Shared_Passive (S, Is_Shared_Passive (E));
7249 Set_Discard_Names (S, Discard_Names (E));
7250 Set_Suppress_Value_Tracking_On_Call
7251 (S, Suppress_Value_Tracking_On_Call (E));
7252 Set_Categorization_From_Scope (E => S, Scop => E);
7256 if Is_Child_Unit (S)
7257 and then Present (E)
7258 and then Ekind_In (E, E_Package, E_Generic_Package)
7260 Nkind (Parent (Unit_Declaration_Node (E))) = N_Compilation_Unit
7263 Aux : constant Node_Id :=
7264 Aux_Decls_Node (Parent (Unit_Declaration_Node (E)));
7266 if Present (Default_Storage_Pool (Aux)) then
7267 Default_Pool := Default_Storage_Pool (Aux);
7273 ---------------------
7274 -- Premature_Usage --
7275 ---------------------
7277 procedure Premature_Usage (N : Node_Id) is
7278 Kind : constant Node_Kind := Nkind (Parent (Entity (N)));
7279 E : Entity_Id := Entity (N);
7282 -- Within an instance, the analysis of the actual for a formal object
7283 -- does not see the name of the object itself. This is significant only
7284 -- if the object is an aggregate, where its analysis does not do any
7285 -- name resolution on component associations. (see 4717-008). In such a
7286 -- case, look for the visible homonym on the chain.
7289 and then Present (Homonym (E))
7294 and then not In_Open_Scopes (Scope (E))
7301 Set_Etype (N, Etype (E));
7306 if Kind = N_Component_Declaration then
7308 ("component&! cannot be used before end of record declaration", N);
7310 elsif Kind = N_Parameter_Specification then
7312 ("formal parameter&! cannot be used before end of specification",
7315 elsif Kind = N_Discriminant_Specification then
7317 ("discriminant&! cannot be used before end of discriminant part",
7320 elsif Kind = N_Procedure_Specification
7321 or else Kind = N_Function_Specification
7324 ("subprogram&! cannot be used before end of its declaration",
7327 elsif Kind = N_Full_Type_Declaration then
7329 ("type& cannot be used before end of its declaration!", N);
7333 ("object& cannot be used before end of its declaration!", N);
7335 end Premature_Usage;
7337 ------------------------
7338 -- Present_System_Aux --
7339 ------------------------
7341 function Present_System_Aux (N : Node_Id := Empty) return Boolean is
7343 Aux_Name : Unit_Name_Type;
7344 Unum : Unit_Number_Type;
7349 function Find_System (C_Unit : Node_Id) return Entity_Id;
7350 -- Scan context clause of compilation unit to find with_clause
7357 function Find_System (C_Unit : Node_Id) return Entity_Id is
7358 With_Clause : Node_Id;
7361 With_Clause := First (Context_Items (C_Unit));
7362 while Present (With_Clause) loop
7363 if (Nkind (With_Clause) = N_With_Clause
7364 and then Chars (Name (With_Clause)) = Name_System)
7365 and then Comes_From_Source (With_Clause)
7376 -- Start of processing for Present_System_Aux
7379 -- The child unit may have been loaded and analyzed already
7381 if Present (System_Aux_Id) then
7384 -- If no previous pragma for System.Aux, nothing to load
7386 elsif No (System_Extend_Unit) then
7389 -- Use the unit name given in the pragma to retrieve the unit.
7390 -- Verify that System itself appears in the context clause of the
7391 -- current compilation. If System is not present, an error will
7392 -- have been reported already.
7395 With_Sys := Find_System (Cunit (Current_Sem_Unit));
7397 The_Unit := Unit (Cunit (Current_Sem_Unit));
7401 (Nkind (The_Unit) = N_Package_Body
7402 or else (Nkind (The_Unit) = N_Subprogram_Body
7404 not Acts_As_Spec (Cunit (Current_Sem_Unit))))
7406 With_Sys := Find_System (Library_Unit (Cunit (Current_Sem_Unit)));
7410 and then Present (N)
7412 -- If we are compiling a subunit, we need to examine its
7413 -- context as well (Current_Sem_Unit is the parent unit);
7415 The_Unit := Parent (N);
7416 while Nkind (The_Unit) /= N_Compilation_Unit loop
7417 The_Unit := Parent (The_Unit);
7420 if Nkind (Unit (The_Unit)) = N_Subunit then
7421 With_Sys := Find_System (The_Unit);
7425 if No (With_Sys) then
7429 Loc := Sloc (With_Sys);
7430 Get_Name_String (Chars (Expression (System_Extend_Unit)));
7431 Name_Buffer (8 .. Name_Len + 7) := Name_Buffer (1 .. Name_Len);
7432 Name_Buffer (1 .. 7) := "system.";
7433 Name_Buffer (Name_Len + 8) := '%';
7434 Name_Buffer (Name_Len + 9) := 's';
7435 Name_Len := Name_Len + 9;
7436 Aux_Name := Name_Find;
7440 (Load_Name => Aux_Name,
7443 Error_Node => With_Sys);
7445 if Unum /= No_Unit then
7446 Semantics (Cunit (Unum));
7448 Defining_Entity (Specification (Unit (Cunit (Unum))));
7451 Make_With_Clause (Loc,
7453 Make_Expanded_Name (Loc,
7454 Chars => Chars (System_Aux_Id),
7455 Prefix => New_Reference_To (Scope (System_Aux_Id), Loc),
7456 Selector_Name => New_Reference_To (System_Aux_Id, Loc)));
7458 Set_Entity (Name (Withn), System_Aux_Id);
7460 Set_Library_Unit (Withn, Cunit (Unum));
7461 Set_Corresponding_Spec (Withn, System_Aux_Id);
7462 Set_First_Name (Withn, True);
7463 Set_Implicit_With (Withn, True);
7465 Insert_After (With_Sys, Withn);
7466 Mark_Rewrite_Insertion (Withn);
7467 Set_Context_Installed (Withn);
7471 -- Here if unit load failed
7474 Error_Msg_Name_1 := Name_System;
7475 Error_Msg_Name_2 := Chars (Expression (System_Extend_Unit));
7477 ("extension package `%.%` does not exist",
7478 Opt.System_Extend_Unit);
7482 end Present_System_Aux;
7484 -------------------------
7485 -- Restore_Scope_Stack --
7486 -------------------------
7488 procedure Restore_Scope_Stack (Handle_Use : Boolean := True) is
7491 Comp_Unit : Node_Id;
7492 In_Child : Boolean := False;
7493 Full_Vis : Boolean := True;
7494 SS_Last : constant Int := Scope_Stack.Last;
7497 -- Restore visibility of previous scope stack, if any
7499 for J in reverse 0 .. Scope_Stack.Last loop
7500 exit when Scope_Stack.Table (J).Entity = Standard_Standard
7501 or else No (Scope_Stack.Table (J).Entity);
7503 S := Scope_Stack.Table (J).Entity;
7505 if not Is_Hidden_Open_Scope (S) then
7507 -- If the parent scope is hidden, its entities are hidden as
7508 -- well, unless the entity is the instantiation currently
7511 if not Is_Hidden_Open_Scope (Scope (S))
7512 or else not Analyzed (Parent (S))
7513 or else Scope (S) = Standard_Standard
7515 Set_Is_Immediately_Visible (S, True);
7518 E := First_Entity (S);
7519 while Present (E) loop
7520 if Is_Child_Unit (E) then
7521 if not From_With_Type (E) then
7522 Set_Is_Immediately_Visible (E,
7523 Is_Visible_Child_Unit (E) or else In_Open_Scopes (E));
7527 (Nkind (Parent (E)) = N_Defining_Program_Unit_Name
7529 Nkind (Parent (Parent (E))) = N_Package_Specification);
7530 Set_Is_Immediately_Visible (E,
7531 Limited_View_Installed (Parent (Parent (E))));
7534 Set_Is_Immediately_Visible (E, True);
7540 and then Is_Package_Or_Generic_Package (S)
7542 -- We are in the visible part of the package scope
7544 exit when E = First_Private_Entity (S);
7548 -- The visibility of child units (siblings of current compilation)
7549 -- must be restored in any case. Their declarations may appear
7550 -- after the private part of the parent.
7552 if not Full_Vis then
7553 while Present (E) loop
7554 if Is_Child_Unit (E) then
7555 Set_Is_Immediately_Visible (E,
7556 Is_Visible_Child_Unit (E) or else In_Open_Scopes (E));
7564 if Is_Child_Unit (S)
7565 and not In_Child -- check only for current unit
7569 -- Restore visibility of parents according to whether the child
7570 -- is private and whether we are in its visible part.
7572 Comp_Unit := Parent (Unit_Declaration_Node (S));
7574 if Nkind (Comp_Unit) = N_Compilation_Unit
7575 and then Private_Present (Comp_Unit)
7579 elsif Is_Package_Or_Generic_Package (S)
7580 and then (In_Private_Part (S) or else In_Package_Body (S))
7584 -- if S is the scope of some instance (which has already been
7585 -- seen on the stack) it does not affect the visibility of
7588 elsif Is_Hidden_Open_Scope (S) then
7591 elsif (Ekind (S) = E_Procedure
7592 or else Ekind (S) = E_Function)
7593 and then Has_Completion (S)
7604 if SS_Last >= Scope_Stack.First
7605 and then Scope_Stack.Table (SS_Last).Entity /= Standard_Standard
7608 Install_Use_Clauses (Scope_Stack.Table (SS_Last).First_Use_Clause);
7610 end Restore_Scope_Stack;
7612 ----------------------
7613 -- Save_Scope_Stack --
7614 ----------------------
7616 procedure Save_Scope_Stack (Handle_Use : Boolean := True) is
7619 SS_Last : constant Int := Scope_Stack.Last;
7622 if SS_Last >= Scope_Stack.First
7623 and then Scope_Stack.Table (SS_Last).Entity /= Standard_Standard
7626 End_Use_Clauses (Scope_Stack.Table (SS_Last).First_Use_Clause);
7629 -- If the call is from within a compilation unit, as when called from
7630 -- Rtsfind, make current entries in scope stack invisible while we
7631 -- analyze the new unit.
7633 for J in reverse 0 .. SS_Last loop
7634 exit when Scope_Stack.Table (J).Entity = Standard_Standard
7635 or else No (Scope_Stack.Table (J).Entity);
7637 S := Scope_Stack.Table (J).Entity;
7638 Set_Is_Immediately_Visible (S, False);
7640 E := First_Entity (S);
7641 while Present (E) loop
7642 Set_Is_Immediately_Visible (E, False);
7648 end Save_Scope_Stack;
7654 procedure Set_Use (L : List_Id) is
7656 Pack_Name : Node_Id;
7663 while Present (Decl) loop
7664 if Nkind (Decl) = N_Use_Package_Clause then
7665 Chain_Use_Clause (Decl);
7667 Pack_Name := First (Names (Decl));
7668 while Present (Pack_Name) loop
7669 Pack := Entity (Pack_Name);
7671 if Ekind (Pack) = E_Package
7672 and then Applicable_Use (Pack_Name)
7674 Use_One_Package (Pack, Decl);
7680 elsif Nkind (Decl) = N_Use_Type_Clause then
7681 Chain_Use_Clause (Decl);
7683 Id := First (Subtype_Marks (Decl));
7684 while Present (Id) loop
7685 if Entity (Id) /= Any_Type then
7698 ---------------------
7699 -- Use_One_Package --
7700 ---------------------
7702 procedure Use_One_Package (P : Entity_Id; N : Node_Id) is
7705 Current_Instance : Entity_Id := Empty;
7707 Private_With_OK : Boolean := False;
7710 if Ekind (P) /= E_Package then
7715 Set_Current_Use_Clause (P, N);
7717 -- Ada 2005 (AI-50217): Check restriction
7719 if From_With_Type (P) then
7720 Error_Msg_N ("limited withed package cannot appear in use clause", N);
7723 -- Find enclosing instance, if any
7726 Current_Instance := Current_Scope;
7727 while not Is_Generic_Instance (Current_Instance) loop
7728 Current_Instance := Scope (Current_Instance);
7731 if No (Hidden_By_Use_Clause (N)) then
7732 Set_Hidden_By_Use_Clause (N, New_Elmt_List);
7736 -- If unit is a package renaming, indicate that the renamed
7737 -- package is also in use (the flags on both entities must
7738 -- remain consistent, and a subsequent use of either of them
7739 -- should be recognized as redundant).
7741 if Present (Renamed_Object (P)) then
7742 Set_In_Use (Renamed_Object (P));
7743 Set_Current_Use_Clause (Renamed_Object (P), N);
7744 Real_P := Renamed_Object (P);
7749 -- Ada 2005 (AI-262): Check the use_clause of a private withed package
7750 -- found in the private part of a package specification
7752 if In_Private_Part (Current_Scope)
7753 and then Has_Private_With (P)
7754 and then Is_Child_Unit (Current_Scope)
7755 and then Is_Child_Unit (P)
7756 and then Is_Ancestor_Package (Scope (Current_Scope), P)
7758 Private_With_OK := True;
7761 -- Loop through entities in one package making them potentially
7764 Id := First_Entity (P);
7766 and then (Id /= First_Private_Entity (P)
7767 or else Private_With_OK) -- Ada 2005 (AI-262)
7769 Prev := Current_Entity (Id);
7770 while Present (Prev) loop
7771 if Is_Immediately_Visible (Prev)
7772 and then (not Is_Overloadable (Prev)
7773 or else not Is_Overloadable (Id)
7774 or else (Type_Conformant (Id, Prev)))
7776 if No (Current_Instance) then
7778 -- Potentially use-visible entity remains hidden
7780 goto Next_Usable_Entity;
7782 -- A use clause within an instance hides outer global entities,
7783 -- which are not used to resolve local entities in the
7784 -- instance. Note that the predefined entities in Standard
7785 -- could not have been hidden in the generic by a use clause,
7786 -- and therefore remain visible. Other compilation units whose
7787 -- entities appear in Standard must be hidden in an instance.
7789 -- To determine whether an entity is external to the instance
7790 -- we compare the scope depth of its scope with that of the
7791 -- current instance. However, a generic actual of a subprogram
7792 -- instance is declared in the wrapper package but will not be
7793 -- hidden by a use-visible entity. similarly, an entity that is
7794 -- declared in an enclosing instance will not be hidden by an
7795 -- an entity declared in a generic actual, which can only have
7796 -- been use-visible in the generic and will not have hidden the
7797 -- entity in the generic parent.
7799 -- If Id is called Standard, the predefined package with the
7800 -- same name is in the homonym chain. It has to be ignored
7801 -- because it has no defined scope (being the only entity in
7802 -- the system with this mandated behavior).
7804 elsif not Is_Hidden (Id)
7805 and then Present (Scope (Prev))
7806 and then not Is_Wrapper_Package (Scope (Prev))
7807 and then Scope_Depth (Scope (Prev)) <
7808 Scope_Depth (Current_Instance)
7809 and then (Scope (Prev) /= Standard_Standard
7810 or else Sloc (Prev) > Standard_Location)
7812 if In_Open_Scopes (Scope (Prev))
7813 and then Is_Generic_Instance (Scope (Prev))
7814 and then Present (Associated_Formal_Package (P))
7819 Set_Is_Potentially_Use_Visible (Id);
7820 Set_Is_Immediately_Visible (Prev, False);
7821 Append_Elmt (Prev, Hidden_By_Use_Clause (N));
7825 -- A user-defined operator is not use-visible if the predefined
7826 -- operator for the type is immediately visible, which is the case
7827 -- if the type of the operand is in an open scope. This does not
7828 -- apply to user-defined operators that have operands of different
7829 -- types, because the predefined mixed mode operations (multiply
7830 -- and divide) apply to universal types and do not hide anything.
7832 elsif Ekind (Prev) = E_Operator
7833 and then Operator_Matches_Spec (Prev, Id)
7834 and then In_Open_Scopes
7835 (Scope (Base_Type (Etype (First_Formal (Id)))))
7836 and then (No (Next_Formal (First_Formal (Id)))
7837 or else Etype (First_Formal (Id))
7838 = Etype (Next_Formal (First_Formal (Id)))
7839 or else Chars (Prev) = Name_Op_Expon)
7841 goto Next_Usable_Entity;
7843 -- In an instance, two homonyms may become use_visible through the
7844 -- actuals of distinct formal packages. In the generic, only the
7845 -- current one would have been visible, so make the other one
7848 elsif Present (Current_Instance)
7849 and then Is_Potentially_Use_Visible (Prev)
7850 and then not Is_Overloadable (Prev)
7851 and then Scope (Id) /= Scope (Prev)
7852 and then Used_As_Generic_Actual (Scope (Prev))
7853 and then Used_As_Generic_Actual (Scope (Id))
7854 and then not In_Same_List (Current_Use_Clause (Scope (Prev)),
7855 Current_Use_Clause (Scope (Id)))
7857 Set_Is_Potentially_Use_Visible (Prev, False);
7858 Append_Elmt (Prev, Hidden_By_Use_Clause (N));
7861 Prev := Homonym (Prev);
7864 -- On exit, we know entity is not hidden, unless it is private
7866 if not Is_Hidden (Id)
7867 and then ((not Is_Child_Unit (Id))
7868 or else Is_Visible_Child_Unit (Id))
7870 Set_Is_Potentially_Use_Visible (Id);
7872 if Is_Private_Type (Id)
7873 and then Present (Full_View (Id))
7875 Set_Is_Potentially_Use_Visible (Full_View (Id));
7879 <<Next_Usable_Entity>>
7883 -- Child units are also made use-visible by a use clause, but they may
7884 -- appear after all visible declarations in the parent entity list.
7886 while Present (Id) loop
7887 if Is_Child_Unit (Id)
7888 and then Is_Visible_Child_Unit (Id)
7890 Set_Is_Potentially_Use_Visible (Id);
7896 if Chars (Real_P) = Name_System
7897 and then Scope (Real_P) = Standard_Standard
7898 and then Present_System_Aux (N)
7900 Use_One_Package (System_Aux_Id, N);
7903 end Use_One_Package;
7909 procedure Use_One_Type (Id : Node_Id; Installed : Boolean := False) is
7911 Is_Known_Used : Boolean;
7915 function Spec_Reloaded_For_Body return Boolean;
7916 -- Determine whether the compilation unit is a package body and the use
7917 -- type clause is in the spec of the same package. Even though the spec
7918 -- was analyzed first, its context is reloaded when analysing the body.
7920 procedure Use_Class_Wide_Operations (Typ : Entity_Id);
7921 -- AI05-150: if the use_type_clause carries the "all" qualifier,
7922 -- class-wide operations of ancestor types are use-visible if the
7923 -- ancestor type is visible.
7925 ----------------------------
7926 -- Spec_Reloaded_For_Body --
7927 ----------------------------
7929 function Spec_Reloaded_For_Body return Boolean is
7931 if Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Body then
7933 Spec : constant Node_Id :=
7934 Parent (List_Containing (Parent (Id)));
7937 Nkind (Spec) = N_Package_Specification
7938 and then Corresponding_Body (Parent (Spec)) =
7939 Cunit_Entity (Current_Sem_Unit);
7944 end Spec_Reloaded_For_Body;
7946 -------------------------------
7947 -- Use_Class_Wide_Operations --
7948 -------------------------------
7950 procedure Use_Class_Wide_Operations (Typ : Entity_Id) is
7954 function Is_Class_Wide_Operation_Of
7956 T : Entity_Id) return Boolean;
7957 -- Determine whether a subprogram has a class-wide parameter or
7958 -- result that is T'Class.
7960 ---------------------------------
7961 -- Is_Class_Wide_Operation_Of --
7962 ---------------------------------
7964 function Is_Class_Wide_Operation_Of
7966 T : Entity_Id) return Boolean
7971 Formal := First_Formal (Op);
7972 while Present (Formal) loop
7973 if Etype (Formal) = Class_Wide_Type (T) then
7976 Next_Formal (Formal);
7979 if Etype (Op) = Class_Wide_Type (T) then
7984 end Is_Class_Wide_Operation_Of;
7986 -- Start of processing for Use_Class_Wide_Operations
7989 Scop := Scope (Typ);
7990 if not Is_Hidden (Scop) then
7991 Ent := First_Entity (Scop);
7992 while Present (Ent) loop
7993 if Is_Overloadable (Ent)
7994 and then Is_Class_Wide_Operation_Of (Ent, Typ)
7995 and then not Is_Potentially_Use_Visible (Ent)
7997 Set_Is_Potentially_Use_Visible (Ent);
7998 Append_Elmt (Ent, Used_Operations (Parent (Id)));
8005 if Is_Derived_Type (Typ) then
8006 Use_Class_Wide_Operations (Etype (Base_Type (Typ)));
8008 end Use_Class_Wide_Operations;
8010 -- Start of processing for Use_One_Type;
8013 -- It is the type determined by the subtype mark (8.4(8)) whose
8014 -- operations become potentially use-visible.
8016 T := Base_Type (Entity (Id));
8018 -- Either the type itself is used, the package where it is declared
8019 -- is in use or the entity is declared in the current package, thus
8024 or else In_Use (Scope (T))
8025 or else Scope (T) = Current_Scope;
8027 Set_Redundant_Use (Id,
8028 Is_Known_Used or else Is_Potentially_Use_Visible (T));
8030 if Ekind (T) = E_Incomplete_Type then
8031 Error_Msg_N ("premature usage of incomplete type", Id);
8033 elsif In_Open_Scopes (Scope (T)) then
8036 -- A limited view cannot appear in a use_type clause. However, an access
8037 -- type whose designated type is limited has the flag but is not itself
8038 -- a limited view unless we only have a limited view of its enclosing
8041 elsif From_With_Type (T)
8042 and then From_With_Type (Scope (T))
8045 ("incomplete type from limited view "
8046 & "cannot appear in use clause", Id);
8048 -- If the subtype mark designates a subtype in a different package,
8049 -- we have to check that the parent type is visible, otherwise the
8050 -- use type clause is a noop. Not clear how to do that???
8052 elsif not Redundant_Use (Id) then
8055 -- If T is tagged, primitive operators on class-wide operands
8056 -- are also available.
8058 if Is_Tagged_Type (T) then
8059 Set_In_Use (Class_Wide_Type (T));
8062 Set_Current_Use_Clause (T, Parent (Id));
8064 -- Iterate over primitive operations of the type. If an operation is
8065 -- already use_visible, it is the result of a previous use_clause,
8066 -- and already appears on the corresponding entity chain. If the
8067 -- clause is being reinstalled, operations are already use-visible.
8073 Op_List := Collect_Primitive_Operations (T);
8074 Elmt := First_Elmt (Op_List);
8075 while Present (Elmt) loop
8076 if (Nkind (Node (Elmt)) = N_Defining_Operator_Symbol
8077 or else Chars (Node (Elmt)) in Any_Operator_Name)
8078 and then not Is_Hidden (Node (Elmt))
8079 and then not Is_Potentially_Use_Visible (Node (Elmt))
8081 Set_Is_Potentially_Use_Visible (Node (Elmt));
8082 Append_Elmt (Node (Elmt), Used_Operations (Parent (Id)));
8084 elsif Ada_Version >= Ada_2012
8085 and then All_Present (Parent (Id))
8086 and then not Is_Hidden (Node (Elmt))
8087 and then not Is_Potentially_Use_Visible (Node (Elmt))
8089 Set_Is_Potentially_Use_Visible (Node (Elmt));
8090 Append_Elmt (Node (Elmt), Used_Operations (Parent (Id)));
8097 if Ada_Version >= Ada_2012
8098 and then All_Present (Parent (Id))
8099 and then Is_Tagged_Type (T)
8101 Use_Class_Wide_Operations (T);
8105 -- If warning on redundant constructs, check for unnecessary WITH
8107 if Warn_On_Redundant_Constructs
8108 and then Is_Known_Used
8110 -- with P; with P; use P;
8111 -- package P is package X is package body X is
8112 -- type T ... use P.T;
8114 -- The compilation unit is the body of X. GNAT first compiles the
8115 -- spec of X, then proceeds to the body. At that point P is marked
8116 -- as use visible. The analysis then reinstalls the spec along with
8117 -- its context. The use clause P.T is now recognized as redundant,
8118 -- but in the wrong context. Do not emit a warning in such cases.
8119 -- Do not emit a warning either if we are in an instance, there is
8120 -- no redundancy between an outer use_clause and one that appears
8121 -- within the generic.
8123 and then not Spec_Reloaded_For_Body
8124 and then not In_Instance
8126 -- The type already has a use clause
8130 -- Case where we know the current use clause for the type
8132 if Present (Current_Use_Clause (T)) then
8133 Use_Clause_Known : declare
8134 Clause1 : constant Node_Id := Parent (Id);
8135 Clause2 : constant Node_Id := Current_Use_Clause (T);
8142 function Entity_Of_Unit (U : Node_Id) return Entity_Id;
8143 -- Return the appropriate entity for determining which unit
8144 -- has a deeper scope: the defining entity for U, unless U
8145 -- is a package instance, in which case we retrieve the
8146 -- entity of the instance spec.
8148 --------------------
8149 -- Entity_Of_Unit --
8150 --------------------
8152 function Entity_Of_Unit (U : Node_Id) return Entity_Id is
8154 if Nkind (U) = N_Package_Instantiation
8155 and then Analyzed (U)
8157 return Defining_Entity (Instance_Spec (U));
8159 return Defining_Entity (U);
8163 -- Start of processing for Use_Clause_Known
8166 -- If both current use type clause and the use type clause
8167 -- for the type are at the compilation unit level, one of
8168 -- the units must be an ancestor of the other, and the
8169 -- warning belongs on the descendant.
8171 if Nkind (Parent (Clause1)) = N_Compilation_Unit
8173 Nkind (Parent (Clause2)) = N_Compilation_Unit
8176 -- If the unit is a subprogram body that acts as spec,
8177 -- the context clause is shared with the constructed
8178 -- subprogram spec. Clearly there is no redundancy.
8180 if Clause1 = Clause2 then
8184 Unit1 := Unit (Parent (Clause1));
8185 Unit2 := Unit (Parent (Clause2));
8187 -- If both clauses are on same unit, or one is the body
8188 -- of the other, or one of them is in a subunit, report
8189 -- redundancy on the later one.
8191 if Unit1 = Unit2 then
8192 Error_Msg_Sloc := Sloc (Current_Use_Clause (T));
8193 Error_Msg_NE -- CODEFIX
8194 ("& is already use-visible through previous "
8195 & "use_type_clause #?", Clause1, T);
8198 elsif Nkind (Unit1) = N_Subunit then
8199 Error_Msg_Sloc := Sloc (Current_Use_Clause (T));
8200 Error_Msg_NE -- CODEFIX
8201 ("& is already use-visible through previous "
8202 & "use_type_clause #?", Clause1, T);
8205 elsif Nkind_In (Unit2, N_Package_Body, N_Subprogram_Body)
8206 and then Nkind (Unit1) /= Nkind (Unit2)
8207 and then Nkind (Unit1) /= N_Subunit
8209 Error_Msg_Sloc := Sloc (Clause1);
8210 Error_Msg_NE -- CODEFIX
8211 ("& is already use-visible through previous "
8212 & "use_type_clause #?", Current_Use_Clause (T), T);
8216 -- There is a redundant use type clause in a child unit.
8217 -- Determine which of the units is more deeply nested.
8218 -- If a unit is a package instance, retrieve the entity
8219 -- and its scope from the instance spec.
8221 Ent1 := Entity_Of_Unit (Unit1);
8222 Ent2 := Entity_Of_Unit (Unit2);
8224 if Scope (Ent2) = Standard_Standard then
8225 Error_Msg_Sloc := Sloc (Current_Use_Clause (T));
8228 elsif Scope (Ent1) = Standard_Standard then
8229 Error_Msg_Sloc := Sloc (Id);
8232 -- If both units are child units, we determine which one
8233 -- is the descendant by the scope distance to the
8234 -- ultimate parent unit.
8244 and then Present (S2)
8245 and then S1 /= Standard_Standard
8246 and then S2 /= Standard_Standard
8252 if S1 = Standard_Standard then
8253 Error_Msg_Sloc := Sloc (Id);
8256 Error_Msg_Sloc := Sloc (Current_Use_Clause (T));
8262 Error_Msg_NE -- CODEFIX
8263 ("& is already use-visible through previous "
8264 & "use_type_clause #?", Err_No, Id);
8266 -- Case where current use type clause and the use type
8267 -- clause for the type are not both at the compilation unit
8268 -- level. In this case we don't have location information.
8271 Error_Msg_NE -- CODEFIX
8272 ("& is already use-visible through previous "
8273 & "use type clause?", Id, T);
8275 end Use_Clause_Known;
8277 -- Here if Current_Use_Clause is not set for T, another case
8278 -- where we do not have the location information available.
8281 Error_Msg_NE -- CODEFIX
8282 ("& is already use-visible through previous "
8283 & "use type clause?", Id, T);
8286 -- The package where T is declared is already used
8288 elsif In_Use (Scope (T)) then
8289 Error_Msg_Sloc := Sloc (Current_Use_Clause (Scope (T)));
8290 Error_Msg_NE -- CODEFIX
8291 ("& is already use-visible through package use clause #?",
8294 -- The current scope is the package where T is declared
8297 Error_Msg_Node_2 := Scope (T);
8298 Error_Msg_NE -- CODEFIX
8299 ("& is already use-visible inside package &?", Id, T);
8308 procedure Write_Info is
8309 Id : Entity_Id := First_Entity (Current_Scope);
8312 -- No point in dumping standard entities
8314 if Current_Scope = Standard_Standard then
8318 Write_Str ("========================================================");
8320 Write_Str (" Defined Entities in ");
8321 Write_Name (Chars (Current_Scope));
8323 Write_Str ("========================================================");
8327 Write_Str ("-- none --");
8331 while Present (Id) loop
8332 Write_Entity_Info (Id, " ");
8337 if Scope (Current_Scope) = Standard_Standard then
8339 -- Print information on the current unit itself
8341 Write_Entity_Info (Current_Scope, " ");
8354 for J in reverse 1 .. Scope_Stack.Last loop
8355 S := Scope_Stack.Table (J).Entity;
8356 Write_Int (Int (S));
8357 Write_Str (" === ");
8358 Write_Name (Chars (S));
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