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 Id : constant Entity_Id := Defining_Identifier (N);
687 Nam : constant Node_Id := Name (N);
691 procedure Check_Constrained_Object;
692 -- If the nominal type is unconstrained but the renamed object is
693 -- constrained, as can happen with renaming an explicit dereference or
694 -- a function return, build a constrained subtype from the object. If
695 -- the renaming is for a formal in an accept statement, the analysis
696 -- has already established its actual subtype. This is only relevant
697 -- if the renamed object is an explicit dereference.
699 function In_Generic_Scope (E : Entity_Id) return Boolean;
700 -- Determine whether entity E is inside a generic cope
702 ------------------------------
703 -- Check_Constrained_Object --
704 ------------------------------
706 procedure Check_Constrained_Object is
707 Loc : constant Source_Ptr := Sloc (N);
711 if Nkind_In (Nam, N_Function_Call, N_Explicit_Dereference)
712 and then Is_Composite_Type (Etype (Nam))
713 and then not Is_Constrained (Etype (Nam))
714 and then not Has_Unknown_Discriminants (Etype (Nam))
715 and then Expander_Active
717 -- If Actual_Subtype is already set, nothing to do
719 if Ekind_In (Id, E_Variable, E_Constant)
720 and then Present (Actual_Subtype (Id))
725 Subt := Make_Temporary (Loc, 'T');
726 Remove_Side_Effects (Nam);
728 Make_Subtype_Declaration (Loc,
729 Defining_Identifier => Subt,
730 Subtype_Indication =>
731 Make_Subtype_From_Expr (Nam, Etype (Nam))));
732 Rewrite (Subtype_Mark (N), New_Occurrence_Of (Subt, Loc));
733 Set_Etype (Nam, Subt);
736 end Check_Constrained_Object;
738 ----------------------
739 -- In_Generic_Scope --
740 ----------------------
742 function In_Generic_Scope (E : Entity_Id) return Boolean is
747 while Present (S) and then S /= Standard_Standard loop
748 if Is_Generic_Unit (S) then
756 end In_Generic_Scope;
758 -- Start of processing for Analyze_Object_Renaming
765 Check_SPARK_Restriction ("object renaming is not allowed", N);
767 Set_Is_Pure (Id, Is_Pure (Current_Scope));
770 -- The renaming of a component that depends on a discriminant requires
771 -- an actual subtype, because in subsequent use of the object Gigi will
772 -- be unable to locate the actual bounds. This explicit step is required
773 -- when the renaming is generated in removing side effects of an
774 -- already-analyzed expression.
776 if Nkind (Nam) = N_Selected_Component
777 and then Analyzed (Nam)
780 Dec := Build_Actual_Subtype_Of_Component (Etype (Nam), Nam);
782 if Present (Dec) then
783 Insert_Action (N, Dec);
784 T := Defining_Identifier (Dec);
788 -- Complete analysis of the subtype mark in any case, for ASIS use
790 if Present (Subtype_Mark (N)) then
791 Find_Type (Subtype_Mark (N));
794 elsif Present (Subtype_Mark (N)) then
795 Find_Type (Subtype_Mark (N));
796 T := Entity (Subtype_Mark (N));
799 if Nkind (Nam) = N_Type_Conversion
800 and then not Is_Tagged_Type (T)
803 ("renaming of conversion only allowed for tagged types", Nam);
808 -- Check that a class-wide object is not being renamed as an object
809 -- of a specific type. The test for access types is needed to exclude
810 -- cases where the renamed object is a dynamically tagged access
811 -- result, such as occurs in certain expansions.
813 if Is_Tagged_Type (T) then
814 Check_Dynamically_Tagged_Expression
820 -- Ada 2005 (AI-230/AI-254): Access renaming
822 else pragma Assert (Present (Access_Definition (N)));
823 T := Access_Definition
825 N => Access_Definition (N));
829 -- Ada 2005 AI05-105: if the declaration has an anonymous access
830 -- type, the renamed object must also have an anonymous type, and
831 -- this is a name resolution rule. This was implicit in the last
832 -- part of the first sentence in 8.5.1.(3/2), and is made explicit
833 -- by this recent AI.
835 if not Is_Overloaded (Nam) then
836 if Ekind (Etype (Nam)) /= Ekind (T) then
838 ("expect anonymous access type in object renaming", N);
845 Typ : Entity_Id := Empty;
846 Seen : Boolean := False;
849 Get_First_Interp (Nam, I, It);
850 while Present (It.Typ) loop
852 -- Renaming is ambiguous if more than one candidate
853 -- interpretation is type-conformant with the context.
855 if Ekind (It.Typ) = Ekind (T) then
856 if Ekind (T) = E_Anonymous_Access_Subprogram_Type
859 (Designated_Type (T), Designated_Type (It.Typ))
865 ("ambiguous expression in renaming", Nam);
868 elsif Ekind (T) = E_Anonymous_Access_Type
870 Covers (Designated_Type (T), Designated_Type (It.Typ))
876 ("ambiguous expression in renaming", Nam);
880 if Covers (T, It.Typ) then
882 Set_Etype (Nam, Typ);
883 Set_Is_Overloaded (Nam, False);
887 Get_Next_Interp (I, It);
894 -- Ada 2005 (AI-231): "In the case where the type is defined by an
895 -- access_definition, the renamed entity shall be of an access-to-
896 -- constant type if and only if the access_definition defines an
897 -- access-to-constant type" ARM 8.5.1(4)
899 if Constant_Present (Access_Definition (N))
900 and then not Is_Access_Constant (Etype (Nam))
902 Error_Msg_N ("(Ada 2005): the renamed object is not "
903 & "access-to-constant (RM 8.5.1(6))", N);
905 elsif not Constant_Present (Access_Definition (N))
906 and then Is_Access_Constant (Etype (Nam))
908 Error_Msg_N ("(Ada 2005): the renamed object is not "
909 & "access-to-variable (RM 8.5.1(6))", N);
912 if Is_Access_Subprogram_Type (Etype (Nam)) then
913 Check_Subtype_Conformant
914 (Designated_Type (T), Designated_Type (Etype (Nam)));
916 elsif not Subtypes_Statically_Match
917 (Designated_Type (T),
918 Available_View (Designated_Type (Etype (Nam))))
921 ("subtype of renamed object does not statically match", N);
925 -- Special processing for renaming function return object. Some errors
926 -- and warnings are produced only for calls that come from source.
928 if Nkind (Nam) = N_Function_Call then
931 -- Usage is illegal in Ada 83
934 if Comes_From_Source (Nam) then
936 ("(Ada 83) cannot rename function return object", Nam);
939 -- In Ada 95, warn for odd case of renaming parameterless function
940 -- call if this is not a limited type (where this is useful).
943 if Warn_On_Object_Renames_Function
944 and then No (Parameter_Associations (Nam))
945 and then not Is_Limited_Type (Etype (Nam))
946 and then Comes_From_Source (Nam)
949 ("?renaming function result object is suspicious", Nam);
951 ("\?function & will be called only once", Nam,
952 Entity (Name (Nam)));
953 Error_Msg_N -- CODEFIX
954 ("\?suggest using an initialized constant object instead",
961 Check_Constrained_Object;
963 -- An object renaming requires an exact match of the type. Class-wide
964 -- matching is not allowed.
966 if Is_Class_Wide_Type (T)
967 and then Base_Type (Etype (Nam)) /= Base_Type (T)
974 -- (Ada 2005: AI-326): Handle wrong use of incomplete type
976 if Nkind (Nam) = N_Explicit_Dereference
977 and then Ekind (Etype (T2)) = E_Incomplete_Type
979 Error_Msg_NE ("invalid use of incomplete type&", Id, T2);
982 elsif Ekind (Etype (T)) = E_Incomplete_Type then
983 Error_Msg_NE ("invalid use of incomplete type&", Id, T);
989 if Ada_Version >= Ada_2005
990 and then Nkind (Nam) = N_Attribute_Reference
991 and then Attribute_Name (Nam) = Name_Priority
995 elsif Ada_Version >= Ada_2005
996 and then Nkind (Nam) in N_Has_Entity
1000 Nam_Ent : Entity_Id;
1003 if Nkind (Nam) = N_Attribute_Reference then
1004 Nam_Ent := Entity (Prefix (Nam));
1006 Nam_Ent := Entity (Nam);
1009 Nam_Decl := Parent (Nam_Ent);
1011 if Has_Null_Exclusion (N)
1012 and then not Has_Null_Exclusion (Nam_Decl)
1014 -- Ada 2005 (AI-423): If the object name denotes a generic
1015 -- formal object of a generic unit G, and the object renaming
1016 -- declaration occurs within the body of G or within the body
1017 -- of a generic unit declared within the declarative region
1018 -- of G, then the declaration of the formal object of G must
1019 -- have a null exclusion or a null-excluding subtype.
1021 if Is_Formal_Object (Nam_Ent)
1022 and then In_Generic_Scope (Id)
1024 if not Can_Never_Be_Null (Etype (Nam_Ent)) then
1026 ("renamed formal does not exclude `NULL` "
1027 & "(RM 8.5.1(4.6/2))", N);
1029 elsif In_Package_Body (Scope (Id)) then
1031 ("formal object does not have a null exclusion"
1032 & "(RM 8.5.1(4.6/2))", N);
1035 -- Ada 2005 (AI-423): Otherwise, the subtype of the object name
1036 -- shall exclude null.
1038 elsif not Can_Never_Be_Null (Etype (Nam_Ent)) then
1040 ("renamed object does not exclude `NULL` "
1041 & "(RM 8.5.1(4.6/2))", N);
1043 -- An instance is illegal if it contains a renaming that
1044 -- excludes null, and the actual does not. The renaming
1045 -- declaration has already indicated that the declaration
1046 -- of the renamed actual in the instance will raise
1047 -- constraint_error.
1049 elsif Nkind (Nam_Decl) = N_Object_Declaration
1050 and then In_Instance
1052 (Corresponding_Generic_Association (Nam_Decl))
1053 and then Nkind (Expression (Nam_Decl))
1054 = N_Raise_Constraint_Error
1057 ("renamed actual does not exclude `NULL` "
1058 & "(RM 8.5.1(4.6/2))", N);
1060 -- Finally, if there is a null exclusion, the subtype mark
1061 -- must not be null-excluding.
1063 elsif No (Access_Definition (N))
1064 and then Can_Never_Be_Null (T)
1067 ("`NOT NULL` not allowed (& already excludes null)",
1072 elsif Can_Never_Be_Null (T)
1073 and then not Can_Never_Be_Null (Etype (Nam_Ent))
1076 ("renamed object does not exclude `NULL` "
1077 & "(RM 8.5.1(4.6/2))", N);
1079 elsif Has_Null_Exclusion (N)
1080 and then No (Access_Definition (N))
1081 and then Can_Never_Be_Null (T)
1084 ("`NOT NULL` not allowed (& already excludes null)", N, T);
1089 Set_Ekind (Id, E_Variable);
1090 Init_Size_Align (Id);
1092 if T = Any_Type or else Etype (Nam) = Any_Type then
1095 -- Verify that the renamed entity is an object or a function call. It
1096 -- may have been rewritten in several ways.
1098 elsif Is_Object_Reference (Nam) then
1099 if Comes_From_Source (N)
1100 and then Is_Dependent_Component_Of_Mutable_Object (Nam)
1103 ("illegal renaming of discriminant-dependent component", Nam);
1106 -- A static function call may have been folded into a literal
1108 elsif Nkind (Original_Node (Nam)) = N_Function_Call
1110 -- When expansion is disabled, attribute reference is not
1111 -- rewritten as function call. Otherwise it may be rewritten
1112 -- as a conversion, so check original node.
1114 or else (Nkind (Original_Node (Nam)) = N_Attribute_Reference
1115 and then Is_Function_Attribute_Name
1116 (Attribute_Name (Original_Node (Nam))))
1118 -- Weird but legal, equivalent to renaming a function call.
1119 -- Illegal if the literal is the result of constant-folding an
1120 -- attribute reference that is not a function.
1122 or else (Is_Entity_Name (Nam)
1123 and then Ekind (Entity (Nam)) = E_Enumeration_Literal
1125 Nkind (Original_Node (Nam)) /= N_Attribute_Reference)
1127 or else (Nkind (Nam) = N_Type_Conversion
1128 and then Is_Tagged_Type (Entity (Subtype_Mark (Nam))))
1132 elsif Nkind (Nam) = N_Type_Conversion then
1134 ("renaming of conversion only allowed for tagged types", Nam);
1136 -- Ada 2005 (AI-327)
1138 elsif Ada_Version >= Ada_2005
1139 and then Nkind (Nam) = N_Attribute_Reference
1140 and then Attribute_Name (Nam) = Name_Priority
1144 -- Allow internally generated x'Reference expression
1146 elsif Nkind (Nam) = N_Reference then
1150 Error_Msg_N ("expect object name in renaming", Nam);
1155 if not Is_Variable (Nam) then
1156 Set_Ekind (Id, E_Constant);
1157 Set_Never_Set_In_Source (Id, True);
1158 Set_Is_True_Constant (Id, True);
1161 Set_Renamed_Object (Id, Nam);
1162 end Analyze_Object_Renaming;
1164 ------------------------------
1165 -- Analyze_Package_Renaming --
1166 ------------------------------
1168 procedure Analyze_Package_Renaming (N : Node_Id) is
1169 New_P : constant Entity_Id := Defining_Entity (N);
1174 if Name (N) = Error then
1178 -- Apply Text_IO kludge here since we may be renaming a child of Text_IO
1180 Text_IO_Kludge (Name (N));
1182 if Current_Scope /= Standard_Standard then
1183 Set_Is_Pure (New_P, Is_Pure (Current_Scope));
1189 if Is_Entity_Name (Name (N)) then
1190 Old_P := Entity (Name (N));
1195 if Etype (Old_P) = Any_Type then
1196 Error_Msg_N ("expect package name in renaming", Name (N));
1198 elsif Ekind (Old_P) /= E_Package
1199 and then not (Ekind (Old_P) = E_Generic_Package
1200 and then In_Open_Scopes (Old_P))
1202 if Ekind (Old_P) = E_Generic_Package then
1204 ("generic package cannot be renamed as a package", Name (N));
1206 Error_Msg_Sloc := Sloc (Old_P);
1208 ("expect package name in renaming, found& declared#",
1212 -- Set basic attributes to minimize cascaded errors
1214 Set_Ekind (New_P, E_Package);
1215 Set_Etype (New_P, Standard_Void_Type);
1217 -- Here for OK package renaming
1220 -- Entities in the old package are accessible through the renaming
1221 -- entity. The simplest implementation is to have both packages share
1224 Set_Ekind (New_P, E_Package);
1225 Set_Etype (New_P, Standard_Void_Type);
1227 if Present (Renamed_Object (Old_P)) then
1228 Set_Renamed_Object (New_P, Renamed_Object (Old_P));
1230 Set_Renamed_Object (New_P, Old_P);
1233 Set_Has_Completion (New_P);
1235 Set_First_Entity (New_P, First_Entity (Old_P));
1236 Set_Last_Entity (New_P, Last_Entity (Old_P));
1237 Set_First_Private_Entity (New_P, First_Private_Entity (Old_P));
1238 Check_Library_Unit_Renaming (N, Old_P);
1239 Generate_Reference (Old_P, Name (N));
1241 -- If the renaming is in the visible part of a package, then we set
1242 -- Renamed_In_Spec for the renamed package, to prevent giving
1243 -- warnings about no entities referenced. Such a warning would be
1244 -- overenthusiastic, since clients can see entities in the renamed
1245 -- package via the visible package renaming.
1248 Ent : constant Entity_Id := Cunit_Entity (Current_Sem_Unit);
1250 if Ekind (Ent) = E_Package
1251 and then not In_Private_Part (Ent)
1252 and then In_Extended_Main_Source_Unit (N)
1253 and then Ekind (Old_P) = E_Package
1255 Set_Renamed_In_Spec (Old_P);
1259 -- If this is the renaming declaration of a package instantiation
1260 -- within itself, it is the declaration that ends the list of actuals
1261 -- for the instantiation. At this point, the subtypes that rename
1262 -- the actuals are flagged as generic, to avoid spurious ambiguities
1263 -- if the actuals for two distinct formals happen to coincide. If
1264 -- the actual is a private type, the subtype has a private completion
1265 -- that is flagged in the same fashion.
1267 -- Resolution is identical to what is was in the original generic.
1268 -- On exit from the generic instance, these are turned into regular
1269 -- subtypes again, so they are compatible with types in their class.
1271 if not Is_Generic_Instance (Old_P) then
1274 Spec := Specification (Unit_Declaration_Node (Old_P));
1277 if Nkind (Spec) = N_Package_Specification
1278 and then Present (Generic_Parent (Spec))
1279 and then Old_P = Current_Scope
1280 and then Chars (New_P) = Chars (Generic_Parent (Spec))
1286 E := First_Entity (Old_P);
1291 and then Nkind (Parent (E)) = N_Subtype_Declaration
1293 Set_Is_Generic_Actual_Type (E);
1295 if Is_Private_Type (E)
1296 and then Present (Full_View (E))
1298 Set_Is_Generic_Actual_Type (Full_View (E));
1307 end Analyze_Package_Renaming;
1309 -------------------------------
1310 -- Analyze_Renamed_Character --
1311 -------------------------------
1313 procedure Analyze_Renamed_Character
1318 C : constant Node_Id := Name (N);
1321 if Ekind (New_S) = E_Function then
1322 Resolve (C, Etype (New_S));
1325 Check_Frozen_Renaming (N, New_S);
1329 Error_Msg_N ("character literal can only be renamed as function", N);
1331 end Analyze_Renamed_Character;
1333 ---------------------------------
1334 -- Analyze_Renamed_Dereference --
1335 ---------------------------------
1337 procedure Analyze_Renamed_Dereference
1342 Nam : constant Node_Id := Name (N);
1343 P : constant Node_Id := Prefix (Nam);
1349 if not Is_Overloaded (P) then
1350 if Ekind (Etype (Nam)) /= E_Subprogram_Type
1351 or else not Type_Conformant (Etype (Nam), New_S)
1353 Error_Msg_N ("designated type does not match specification", P);
1362 Get_First_Interp (Nam, Ind, It);
1364 while Present (It.Nam) loop
1366 if Ekind (It.Nam) = E_Subprogram_Type
1367 and then Type_Conformant (It.Nam, New_S)
1369 if Typ /= Any_Id then
1370 Error_Msg_N ("ambiguous renaming", P);
1377 Get_Next_Interp (Ind, It);
1380 if Typ = Any_Type then
1381 Error_Msg_N ("designated type does not match specification", P);
1386 Check_Frozen_Renaming (N, New_S);
1390 end Analyze_Renamed_Dereference;
1392 ---------------------------
1393 -- Analyze_Renamed_Entry --
1394 ---------------------------
1396 procedure Analyze_Renamed_Entry
1401 Nam : constant Node_Id := Name (N);
1402 Sel : constant Node_Id := Selector_Name (Nam);
1406 if Entity (Sel) = Any_Id then
1408 -- Selector is undefined on prefix. Error emitted already
1410 Set_Has_Completion (New_S);
1414 -- Otherwise find renamed entity and build body of New_S as a call to it
1416 Old_S := Find_Renamed_Entity (N, Selector_Name (Nam), New_S);
1418 if Old_S = Any_Id then
1419 Error_Msg_N (" no subprogram or entry matches specification", N);
1422 Check_Subtype_Conformant (New_S, Old_S, N);
1423 Generate_Reference (New_S, Defining_Entity (N), 'b');
1424 Style.Check_Identifier (Defining_Entity (N), New_S);
1427 -- Only mode conformance required for a renaming_as_declaration
1429 Check_Mode_Conformant (New_S, Old_S, N);
1432 Inherit_Renamed_Profile (New_S, Old_S);
1434 -- The prefix can be an arbitrary expression that yields a task type,
1435 -- so it must be resolved.
1437 Resolve (Prefix (Nam), Scope (Old_S));
1440 Set_Convention (New_S, Convention (Old_S));
1441 Set_Has_Completion (New_S, Inside_A_Generic);
1444 Check_Frozen_Renaming (N, New_S);
1446 end Analyze_Renamed_Entry;
1448 -----------------------------------
1449 -- Analyze_Renamed_Family_Member --
1450 -----------------------------------
1452 procedure Analyze_Renamed_Family_Member
1457 Nam : constant Node_Id := Name (N);
1458 P : constant Node_Id := Prefix (Nam);
1462 if (Is_Entity_Name (P) and then Ekind (Entity (P)) = E_Entry_Family)
1463 or else (Nkind (P) = N_Selected_Component
1465 Ekind (Entity (Selector_Name (P))) = E_Entry_Family)
1467 if Is_Entity_Name (P) then
1468 Old_S := Entity (P);
1470 Old_S := Entity (Selector_Name (P));
1473 if not Entity_Matches_Spec (Old_S, New_S) then
1474 Error_Msg_N ("entry family does not match 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);
1483 Error_Msg_N ("no entry family matches specification", N);
1486 Set_Has_Completion (New_S, Inside_A_Generic);
1489 Check_Frozen_Renaming (N, New_S);
1491 end Analyze_Renamed_Family_Member;
1493 -----------------------------------------
1494 -- Analyze_Renamed_Primitive_Operation --
1495 -----------------------------------------
1497 procedure Analyze_Renamed_Primitive_Operation
1506 Ctyp : Conformance_Type) return Boolean;
1507 -- Verify that the signatures of the renamed entity and the new entity
1508 -- match. The first formal of the renamed entity is skipped because it
1509 -- is the target object in any subsequent call.
1513 Ctyp : Conformance_Type) return Boolean
1519 if Ekind (Subp) /= Ekind (New_S) then
1523 Old_F := Next_Formal (First_Formal (Subp));
1524 New_F := First_Formal (New_S);
1525 while Present (Old_F) and then Present (New_F) loop
1526 if not Conforming_Types (Etype (Old_F), Etype (New_F), Ctyp) then
1530 if Ctyp >= Mode_Conformant
1531 and then Ekind (Old_F) /= Ekind (New_F)
1536 Next_Formal (New_F);
1537 Next_Formal (Old_F);
1544 if not Is_Overloaded (Selector_Name (Name (N))) then
1545 Old_S := Entity (Selector_Name (Name (N)));
1547 if not Conforms (Old_S, Type_Conformant) then
1552 -- Find the operation that matches the given signature
1560 Get_First_Interp (Selector_Name (Name (N)), Ind, It);
1562 while Present (It.Nam) loop
1563 if Conforms (It.Nam, Type_Conformant) then
1567 Get_Next_Interp (Ind, It);
1572 if Old_S = Any_Id then
1573 Error_Msg_N (" no subprogram or entry matches specification", N);
1577 if not Conforms (Old_S, Subtype_Conformant) then
1578 Error_Msg_N ("subtype conformance error in renaming", N);
1581 Generate_Reference (New_S, Defining_Entity (N), 'b');
1582 Style.Check_Identifier (Defining_Entity (N), New_S);
1585 -- Only mode conformance required for a renaming_as_declaration
1587 if not Conforms (Old_S, Mode_Conformant) then
1588 Error_Msg_N ("mode conformance error in renaming", N);
1592 -- Inherit_Renamed_Profile (New_S, Old_S);
1594 -- The prefix can be an arbitrary expression that yields an
1595 -- object, so it must be resolved.
1597 Resolve (Prefix (Name (N)));
1599 end Analyze_Renamed_Primitive_Operation;
1601 ---------------------------------
1602 -- Analyze_Subprogram_Renaming --
1603 ---------------------------------
1605 procedure Analyze_Subprogram_Renaming (N : Node_Id) is
1606 Formal_Spec : constant Node_Id := Corresponding_Formal_Spec (N);
1607 Is_Actual : constant Boolean := Present (Formal_Spec);
1609 CW_Actual : Boolean := False;
1610 -- True if the renaming is for a defaulted formal subprogram when the
1611 -- actual for a related formal type is class-wide. For AI05-0071.
1613 Inst_Node : Node_Id := Empty;
1614 Nam : constant Node_Id := Name (N);
1616 Old_S : Entity_Id := Empty;
1617 Rename_Spec : Entity_Id;
1618 Save_AV : constant Ada_Version_Type := Ada_Version;
1619 Save_AV_Exp : constant Ada_Version_Type := Ada_Version_Explicit;
1620 Spec : constant Node_Id := Specification (N);
1622 procedure Check_Null_Exclusion
1625 -- Ada 2005 (AI-423): Given renaming Ren of subprogram Sub, check the
1626 -- following AI rules:
1628 -- If Ren is a renaming of a formal subprogram and one of its
1629 -- parameters has a null exclusion, then the corresponding formal
1630 -- in Sub must also have one. Otherwise the subtype of the Sub's
1631 -- formal parameter must exclude null.
1633 -- If Ren is a renaming of a formal function and its return
1634 -- profile has a null exclusion, then Sub's return profile must
1635 -- have one. Otherwise the subtype of Sub's return profile must
1638 function Original_Subprogram (Subp : Entity_Id) return Entity_Id;
1639 -- Find renamed entity when the declaration is a renaming_as_body and
1640 -- the renamed entity may itself be a renaming_as_body. Used to enforce
1641 -- rule that a renaming_as_body is illegal if the declaration occurs
1642 -- before the subprogram it completes is frozen, and renaming indirectly
1643 -- renames the subprogram itself.(Defect Report 8652/0027).
1645 function Check_Class_Wide_Actual return Entity_Id;
1646 -- AI05-0071: In an instance, if the actual for a formal type FT with
1647 -- unknown discriminants is a class-wide type CT, and the generic has
1648 -- a formal subprogram with a box for a primitive operation of FT,
1649 -- then the corresponding actual subprogram denoted by the default is a
1650 -- class-wide operation whose body is a dispatching call. We replace the
1651 -- generated renaming declaration:
1653 -- procedure P (X : CT) renames P;
1655 -- by a different renaming and a class-wide operation:
1657 -- procedure Pr (X : T) renames P; -- renames primitive operation
1658 -- procedure P (X : CT); -- class-wide operation
1660 -- procedure P (X : CT) is begin Pr (X); end; -- dispatching call
1662 -- This rule only applies if there is no explicit visible class-wide
1663 -- operation at the point of the instantiation.
1665 -----------------------------
1666 -- Check_Class_Wide_Actual --
1667 -----------------------------
1669 function Check_Class_Wide_Actual return Entity_Id is
1670 Loc : constant Source_Ptr := Sloc (N);
1673 Formal_Type : Entity_Id;
1674 Actual_Type : Entity_Id;
1679 function Make_Call (Prim_Op : Entity_Id) return Node_Id;
1680 -- Build dispatching call for body of class-wide operation
1682 function Make_Spec return Node_Id;
1683 -- Create subprogram specification for declaration and body of
1684 -- class-wide operation, using signature of renaming declaration.
1690 function Make_Call (Prim_Op : Entity_Id) return Node_Id is
1695 Actuals := New_List;
1696 F := First (Parameter_Specifications (Specification (New_Decl)));
1697 while Present (F) loop
1699 Make_Identifier (Loc, Chars (Defining_Identifier (F))));
1703 if Ekind (Prim_Op) = E_Function then
1704 return Make_Simple_Return_Statement (Loc,
1706 Make_Function_Call (Loc,
1707 Name => New_Occurrence_Of (Prim_Op, Loc),
1708 Parameter_Associations => Actuals));
1711 Make_Procedure_Call_Statement (Loc,
1712 Name => New_Occurrence_Of (Prim_Op, Loc),
1713 Parameter_Associations => Actuals);
1721 function Make_Spec return Node_Id is
1722 Param_Specs : constant List_Id := Copy_Parameter_List (New_S);
1725 if Ekind (New_S) = E_Procedure then
1727 Make_Procedure_Specification (Loc,
1728 Defining_Unit_Name =>
1729 Make_Defining_Identifier (Loc,
1730 Chars (Defining_Unit_Name (Spec))),
1731 Parameter_Specifications => Param_Specs);
1734 Make_Function_Specification (Loc,
1735 Defining_Unit_Name =>
1736 Make_Defining_Identifier (Loc,
1737 Chars (Defining_Unit_Name (Spec))),
1738 Parameter_Specifications => Param_Specs,
1739 Result_Definition =>
1740 New_Copy_Tree (Result_Definition (Spec)));
1744 -- Start of processing for Check_Class_Wide_Actual
1748 Formal_Type := Empty;
1749 Actual_Type := Empty;
1751 F := First_Formal (Formal_Spec);
1752 while Present (F) loop
1753 if Has_Unknown_Discriminants (Etype (F))
1754 and then Is_Class_Wide_Type (Get_Instance_Of (Etype (F)))
1756 Formal_Type := Etype (F);
1757 Actual_Type := Etype (Get_Instance_Of (Formal_Type));
1764 if Present (Formal_Type) then
1767 -- Create declaration and body for class-wide operation
1770 Make_Subprogram_Declaration (Loc, Specification => Make_Spec);
1773 Make_Subprogram_Body (Loc,
1774 Specification => Make_Spec,
1775 Declarations => No_List,
1776 Handled_Statement_Sequence =>
1777 Make_Handled_Sequence_Of_Statements (Loc, New_List));
1779 -- Modify Spec and create internal name for renaming of primitive
1782 Set_Defining_Unit_Name (Spec, Make_Temporary (Loc, 'R'));
1783 F := First (Parameter_Specifications (Spec));
1784 while Present (F) loop
1785 if Nkind (Parameter_Type (F)) = N_Identifier
1786 and then Is_Class_Wide_Type (Entity (Parameter_Type (F)))
1788 Set_Parameter_Type (F, New_Occurrence_Of (Actual_Type, Loc));
1793 New_S := Analyze_Subprogram_Specification (Spec);
1794 Result := Find_Renamed_Entity (N, Name (N), New_S, Is_Actual);
1797 if Result /= Any_Id then
1798 Insert_Before (N, New_Decl);
1801 -- Add dispatching call to body of class-wide operation
1803 Append (Make_Call (Result),
1804 Statements (Handled_Statement_Sequence (New_Body)));
1806 -- The generated body does not freeze. It is analyzed when the
1807 -- generated operation is frozen.
1809 Append_Freeze_Action (Defining_Entity (New_Decl), New_Body);
1811 Result := Defining_Entity (New_Decl);
1814 -- Return the class-wide operation if one was created.
1817 end Check_Class_Wide_Actual;
1819 --------------------------
1820 -- Check_Null_Exclusion --
1821 --------------------------
1823 procedure Check_Null_Exclusion
1827 Ren_Formal : Entity_Id;
1828 Sub_Formal : Entity_Id;
1833 Ren_Formal := First_Formal (Ren);
1834 Sub_Formal := First_Formal (Sub);
1835 while Present (Ren_Formal)
1836 and then Present (Sub_Formal)
1838 if Has_Null_Exclusion (Parent (Ren_Formal))
1840 not (Has_Null_Exclusion (Parent (Sub_Formal))
1841 or else Can_Never_Be_Null (Etype (Sub_Formal)))
1844 ("`NOT NULL` required for parameter &",
1845 Parent (Sub_Formal), Sub_Formal);
1848 Next_Formal (Ren_Formal);
1849 Next_Formal (Sub_Formal);
1852 -- Return profile check
1854 if Nkind (Parent (Ren)) = N_Function_Specification
1855 and then Nkind (Parent (Sub)) = N_Function_Specification
1856 and then Has_Null_Exclusion (Parent (Ren))
1858 not (Has_Null_Exclusion (Parent (Sub))
1859 or else Can_Never_Be_Null (Etype (Sub)))
1862 ("return must specify `NOT NULL`",
1863 Result_Definition (Parent (Sub)));
1865 end Check_Null_Exclusion;
1867 -------------------------
1868 -- Original_Subprogram --
1869 -------------------------
1871 function Original_Subprogram (Subp : Entity_Id) return Entity_Id is
1872 Orig_Decl : Node_Id;
1873 Orig_Subp : Entity_Id;
1876 -- First case: renamed entity is itself a renaming
1878 if Present (Alias (Subp)) then
1879 return Alias (Subp);
1882 Nkind (Unit_Declaration_Node (Subp)) = N_Subprogram_Declaration
1884 (Corresponding_Body (Unit_Declaration_Node (Subp)))
1886 -- Check if renamed entity is a renaming_as_body
1889 Unit_Declaration_Node
1890 (Corresponding_Body (Unit_Declaration_Node (Subp)));
1892 if Nkind (Orig_Decl) = N_Subprogram_Renaming_Declaration then
1893 Orig_Subp := Entity (Name (Orig_Decl));
1895 if Orig_Subp = Rename_Spec then
1897 -- Circularity detected
1902 return (Original_Subprogram (Orig_Subp));
1910 end Original_Subprogram;
1912 -- Start of processing for Analyze_Subprogram_Renaming
1915 -- We must test for the attribute renaming case before the Analyze
1916 -- call because otherwise Sem_Attr will complain that the attribute
1917 -- is missing an argument when it is analyzed.
1919 if Nkind (Nam) = N_Attribute_Reference then
1921 -- In the case of an abstract formal subprogram association, rewrite
1922 -- an actual given by a stream attribute as the name of the
1923 -- corresponding stream primitive of the type.
1925 -- In a generic context the stream operations are not generated, and
1926 -- this must be treated as a normal attribute reference, to be
1927 -- expanded in subsequent instantiations.
1929 if Is_Actual and then Is_Abstract_Subprogram (Formal_Spec)
1930 and then Expander_Active
1933 Stream_Prim : Entity_Id;
1934 Prefix_Type : constant Entity_Id := Entity (Prefix (Nam));
1937 -- The class-wide forms of the stream attributes are not
1938 -- primitive dispatching operations (even though they
1939 -- internally dispatch to a stream attribute).
1941 if Is_Class_Wide_Type (Prefix_Type) then
1943 ("attribute must be a primitive dispatching operation",
1948 -- Retrieve the primitive subprogram associated with the
1949 -- attribute. This can only be a stream attribute, since those
1950 -- are the only ones that are dispatching (and the actual for
1951 -- an abstract formal subprogram must be dispatching
1955 case Attribute_Name (Nam) is
1958 Find_Prim_Op (Prefix_Type, TSS_Stream_Input);
1961 Find_Prim_Op (Prefix_Type, TSS_Stream_Output);
1964 Find_Prim_Op (Prefix_Type, TSS_Stream_Read);
1967 Find_Prim_Op (Prefix_Type, TSS_Stream_Write);
1970 ("attribute must be a primitive"
1971 & " dispatching operation", Nam);
1977 -- If no operation was found, and the type is limited,
1978 -- the user should have defined one.
1980 when Program_Error =>
1981 if Is_Limited_Type (Prefix_Type) then
1983 ("stream operation not defined for type&",
1987 -- Otherwise, compiler should have generated default
1994 -- Rewrite the attribute into the name of its corresponding
1995 -- primitive dispatching subprogram. We can then proceed with
1996 -- the usual processing for subprogram renamings.
1999 Prim_Name : constant Node_Id :=
2000 Make_Identifier (Sloc (Nam),
2001 Chars => Chars (Stream_Prim));
2003 Set_Entity (Prim_Name, Stream_Prim);
2004 Rewrite (Nam, Prim_Name);
2009 -- Normal processing for a renaming of an attribute
2012 Attribute_Renaming (N);
2017 -- Check whether this declaration corresponds to the instantiation
2018 -- of a formal subprogram.
2020 -- If this is an instantiation, the corresponding actual is frozen and
2021 -- error messages can be made more precise. If this is a default
2022 -- subprogram, the entity is already established in the generic, and is
2023 -- not retrieved by visibility. If it is a default with a box, the
2024 -- candidate interpretations, if any, have been collected when building
2025 -- the renaming declaration. If overloaded, the proper interpretation is
2026 -- determined in Find_Renamed_Entity. If the entity is an operator,
2027 -- Find_Renamed_Entity applies additional visibility checks.
2030 Inst_Node := Unit_Declaration_Node (Formal_Spec);
2032 if Is_Entity_Name (Nam)
2033 and then Present (Entity (Nam))
2034 and then not Comes_From_Source (Nam)
2035 and then not Is_Overloaded (Nam)
2037 Old_S := Entity (Nam);
2038 New_S := Analyze_Subprogram_Specification (Spec);
2042 if Ekind (Entity (Nam)) = E_Operator then
2046 if Box_Present (Inst_Node) then
2047 Old_S := Find_Renamed_Entity (N, Name (N), New_S, Is_Actual);
2049 -- If there is an immediately visible homonym of the operator
2050 -- and the declaration has a default, this is worth a warning
2051 -- because the user probably did not intend to get the pre-
2052 -- defined operator, visible in the generic declaration. To
2053 -- find if there is an intended candidate, analyze the renaming
2054 -- again in the current context.
2056 elsif Scope (Old_S) = Standard_Standard
2057 and then Present (Default_Name (Inst_Node))
2060 Decl : constant Node_Id := New_Copy_Tree (N);
2064 Set_Entity (Name (Decl), Empty);
2065 Analyze (Name (Decl));
2067 Find_Renamed_Entity (Decl, Name (Decl), New_S, True);
2070 and then In_Open_Scopes (Scope (Hidden))
2071 and then Is_Immediately_Visible (Hidden)
2072 and then Comes_From_Source (Hidden)
2073 and then Hidden /= Old_S
2075 Error_Msg_Sloc := Sloc (Hidden);
2076 Error_Msg_N ("?default subprogram is resolved " &
2077 "in the generic declaration " &
2078 "(RM 12.6(17))", N);
2079 Error_Msg_NE ("\?and will not use & #", N, Hidden);
2087 New_S := Analyze_Subprogram_Specification (Spec);
2091 -- Renamed entity must be analyzed first, to avoid being hidden by
2092 -- new name (which might be the same in a generic instance).
2096 -- The renaming defines a new overloaded entity, which is analyzed
2097 -- like a subprogram declaration.
2099 New_S := Analyze_Subprogram_Specification (Spec);
2102 if Current_Scope /= Standard_Standard then
2103 Set_Is_Pure (New_S, Is_Pure (Current_Scope));
2106 Rename_Spec := Find_Corresponding_Spec (N);
2108 -- Case of Renaming_As_Body
2110 if Present (Rename_Spec) then
2112 -- Renaming declaration is the completion of the declaration of
2113 -- Rename_Spec. We build an actual body for it at the freezing point.
2115 Set_Corresponding_Spec (N, Rename_Spec);
2117 -- Deal with special case of stream functions of abstract types
2120 if Nkind (Unit_Declaration_Node (Rename_Spec)) =
2121 N_Abstract_Subprogram_Declaration
2123 -- Input stream functions are abstract if the object type is
2124 -- abstract. Similarly, all default stream functions for an
2125 -- interface type are abstract. However, these subprograms may
2126 -- receive explicit declarations in representation clauses, making
2127 -- the attribute subprograms usable as defaults in subsequent
2129 -- In this case we rewrite the declaration to make the subprogram
2130 -- non-abstract. We remove the previous declaration, and insert
2131 -- the new one at the point of the renaming, to prevent premature
2132 -- access to unfrozen types. The new declaration reuses the
2133 -- specification of the previous one, and must not be analyzed.
2136 (Is_Primitive (Entity (Nam))
2138 Is_Abstract_Type (Find_Dispatching_Type (Entity (Nam))));
2140 Old_Decl : constant Node_Id :=
2141 Unit_Declaration_Node (Rename_Spec);
2142 New_Decl : constant Node_Id :=
2143 Make_Subprogram_Declaration (Sloc (N),
2145 Relocate_Node (Specification (Old_Decl)));
2148 Insert_After (N, New_Decl);
2149 Set_Is_Abstract_Subprogram (Rename_Spec, False);
2150 Set_Analyzed (New_Decl);
2154 Set_Corresponding_Body (Unit_Declaration_Node (Rename_Spec), New_S);
2156 if Ada_Version = Ada_83 and then Comes_From_Source (N) then
2157 Error_Msg_N ("(Ada 83) renaming cannot serve as a body", N);
2160 Set_Convention (New_S, Convention (Rename_Spec));
2161 Check_Fully_Conformant (New_S, Rename_Spec);
2162 Set_Public_Status (New_S);
2164 -- The specification does not introduce new formals, but only
2165 -- repeats the formals of the original subprogram declaration.
2166 -- For cross-reference purposes, and for refactoring tools, we
2167 -- treat the formals of the renaming declaration as body formals.
2169 Reference_Body_Formals (Rename_Spec, New_S);
2171 -- Indicate that the entity in the declaration functions like the
2172 -- corresponding body, and is not a new entity. The body will be
2173 -- constructed later at the freeze point, so indicate that the
2174 -- completion has not been seen yet.
2176 Set_Ekind (New_S, E_Subprogram_Body);
2177 New_S := Rename_Spec;
2178 Set_Has_Completion (Rename_Spec, False);
2180 -- Ada 2005: check overriding indicator
2182 if Present (Overridden_Operation (Rename_Spec)) then
2183 if Must_Not_Override (Specification (N)) then
2185 ("subprogram& overrides inherited operation",
2188 Style_Check and then not Must_Override (Specification (N))
2190 Style.Missing_Overriding (N, Rename_Spec);
2193 elsif Must_Override (Specification (N)) then
2194 Error_Msg_NE ("subprogram& is not overriding", N, Rename_Spec);
2197 -- Normal subprogram renaming (not renaming as body)
2200 Generate_Definition (New_S);
2201 New_Overloaded_Entity (New_S);
2203 if Is_Entity_Name (Nam)
2204 and then Is_Intrinsic_Subprogram (Entity (Nam))
2208 Check_Delayed_Subprogram (New_S);
2212 -- There is no need for elaboration checks on the new entity, which may
2213 -- be called before the next freezing point where the body will appear.
2214 -- Elaboration checks refer to the real entity, not the one created by
2215 -- the renaming declaration.
2217 Set_Kill_Elaboration_Checks (New_S, True);
2219 if Etype (Nam) = Any_Type then
2220 Set_Has_Completion (New_S);
2223 elsif Nkind (Nam) = N_Selected_Component then
2225 -- A prefix of the form A.B can designate an entry of task A, a
2226 -- protected operation of protected object A, or finally a primitive
2227 -- operation of object A. In the later case, A is an object of some
2228 -- tagged type, or an access type that denotes one such. To further
2229 -- distinguish these cases, note that the scope of a task entry or
2230 -- protected operation is type of the prefix.
2232 -- The prefix could be an overloaded function call that returns both
2233 -- kinds of operations. This overloading pathology is left to the
2234 -- dedicated reader ???
2237 T : constant Entity_Id := Etype (Prefix (Nam));
2246 Is_Tagged_Type (Designated_Type (T))))
2247 and then Scope (Entity (Selector_Name (Nam))) /= T
2249 Analyze_Renamed_Primitive_Operation
2250 (N, New_S, Present (Rename_Spec));
2254 -- Renamed entity is an entry or protected operation. For those
2255 -- cases an explicit body is built (at the point of freezing of
2256 -- this entity) that contains a call to the renamed entity.
2258 -- This is not allowed for renaming as body if the renamed
2259 -- spec is already frozen (see RM 8.5.4(5) for details).
2261 if Present (Rename_Spec)
2262 and then Is_Frozen (Rename_Spec)
2265 ("renaming-as-body cannot rename entry as subprogram", N);
2267 ("\since & is already frozen (RM 8.5.4(5))",
2270 Analyze_Renamed_Entry (N, New_S, Present (Rename_Spec));
2277 elsif Nkind (Nam) = N_Explicit_Dereference then
2279 -- Renamed entity is designated by access_to_subprogram expression.
2280 -- Must build body to encapsulate call, as in the entry case.
2282 Analyze_Renamed_Dereference (N, New_S, Present (Rename_Spec));
2285 elsif Nkind (Nam) = N_Indexed_Component then
2286 Analyze_Renamed_Family_Member (N, New_S, Present (Rename_Spec));
2289 elsif Nkind (Nam) = N_Character_Literal then
2290 Analyze_Renamed_Character (N, New_S, Present (Rename_Spec));
2293 elsif not Is_Entity_Name (Nam)
2294 or else not Is_Overloadable (Entity (Nam))
2296 Error_Msg_N ("expect valid subprogram name in renaming", N);
2300 -- Find the renamed entity that matches the given specification. Disable
2301 -- Ada_83 because there is no requirement of full conformance between
2302 -- renamed entity and new entity, even though the same circuit is used.
2304 -- This is a bit of a kludge, which introduces a really irregular use of
2305 -- Ada_Version[_Explicit]. Would be nice to find cleaner way to do this
2308 Ada_Version := Ada_Version_Type'Max (Ada_Version, Ada_95);
2309 Ada_Version_Explicit := Ada_Version;
2312 Old_S := Find_Renamed_Entity (N, Name (N), New_S, Is_Actual);
2314 -- The visible operation may be an inherited abstract operation that
2315 -- was overridden in the private part, in which case a call will
2316 -- dispatch to the overriding operation. Use the overriding one in
2317 -- the renaming declaration, to prevent spurious errors below.
2319 if Is_Overloadable (Old_S)
2320 and then Is_Abstract_Subprogram (Old_S)
2321 and then No (DTC_Entity (Old_S))
2322 and then Present (Alias (Old_S))
2323 and then not Is_Abstract_Subprogram (Alias (Old_S))
2324 and then Present (Overridden_Operation (Alias (Old_S)))
2326 Old_S := Alias (Old_S);
2329 -- When the renamed subprogram is overloaded and used as an actual
2330 -- of a generic, its entity is set to the first available homonym.
2331 -- We must first disambiguate the name, then set the proper entity.
2334 and then Is_Overloaded (Nam)
2336 Set_Entity (Nam, Old_S);
2340 -- Most common case: subprogram renames subprogram. No body is generated
2341 -- in this case, so we must indicate the declaration is complete as is.
2342 -- and inherit various attributes of the renamed subprogram.
2344 if No (Rename_Spec) then
2345 Set_Has_Completion (New_S);
2346 Set_Is_Imported (New_S, Is_Imported (Entity (Nam)));
2347 Set_Is_Pure (New_S, Is_Pure (Entity (Nam)));
2348 Set_Is_Preelaborated (New_S, Is_Preelaborated (Entity (Nam)));
2350 -- Ada 2005 (AI-423): Check the consistency of null exclusions
2351 -- between a subprogram and its correct renaming.
2353 -- Note: the Any_Id check is a guard that prevents compiler crashes
2354 -- when performing a null exclusion check between a renaming and a
2355 -- renamed subprogram that has been found to be illegal.
2357 if Ada_Version >= Ada_2005
2358 and then Entity (Nam) /= Any_Id
2360 Check_Null_Exclusion
2362 Sub => Entity (Nam));
2365 -- Enforce the Ada 2005 rule that the renamed entity cannot require
2366 -- overriding. The flag Requires_Overriding is set very selectively
2367 -- and misses some other illegal cases. The additional conditions
2368 -- checked below are sufficient but not necessary ???
2370 -- The rule does not apply to the renaming generated for an actual
2371 -- subprogram in an instance.
2376 -- Guard against previous errors, and omit renamings of predefined
2379 elsif not Ekind_In (Old_S, E_Function, E_Procedure) then
2382 elsif Requires_Overriding (Old_S)
2384 (Is_Abstract_Subprogram (Old_S)
2385 and then Present (Find_Dispatching_Type (Old_S))
2387 not Is_Abstract_Type (Find_Dispatching_Type (Old_S)))
2390 ("renamed entity cannot be "
2391 & "subprogram that requires overriding (RM 8.5.4 (5.1))", N);
2395 -- If no renamed entity was found, check whether the renaming is for
2396 -- a defaulted actual subprogram with a class-wide actual.
2400 and then From_Default (N)
2402 Old_S := Check_Class_Wide_Actual;
2405 if Old_S /= Any_Id then
2407 and then From_Default (N)
2409 -- This is an implicit reference to the default actual
2411 Generate_Reference (Old_S, Nam, Typ => 'i', Force => True);
2413 Generate_Reference (Old_S, Nam);
2416 -- For a renaming-as-body, require subtype conformance, but if the
2417 -- declaration being completed has not been frozen, then inherit the
2418 -- convention of the renamed subprogram prior to checking conformance
2419 -- (unless the renaming has an explicit convention established; the
2420 -- rule stated in the RM doesn't seem to address this ???).
2422 if Present (Rename_Spec) then
2423 Generate_Reference (Rename_Spec, Defining_Entity (Spec), 'b');
2424 Style.Check_Identifier (Defining_Entity (Spec), Rename_Spec);
2426 if not Is_Frozen (Rename_Spec) then
2427 if not Has_Convention_Pragma (Rename_Spec) then
2428 Set_Convention (New_S, Convention (Old_S));
2431 if Ekind (Old_S) /= E_Operator then
2432 Check_Mode_Conformant (New_S, Old_S, Spec);
2435 if Original_Subprogram (Old_S) = Rename_Spec then
2436 Error_Msg_N ("unfrozen subprogram cannot rename itself ", N);
2439 Check_Subtype_Conformant (New_S, Old_S, Spec);
2442 Check_Frozen_Renaming (N, Rename_Spec);
2444 -- Check explicitly that renamed entity is not intrinsic, because
2445 -- in a generic the renamed body is not built. In this case,
2446 -- the renaming_as_body is a completion.
2448 if Inside_A_Generic then
2449 if Is_Frozen (Rename_Spec)
2450 and then Is_Intrinsic_Subprogram (Old_S)
2453 ("subprogram in renaming_as_body cannot be intrinsic",
2457 Set_Has_Completion (Rename_Spec);
2460 elsif Ekind (Old_S) /= E_Operator then
2462 -- If this a defaulted subprogram for a class-wide actual there is
2463 -- no check for mode conformance, given that the signatures don't
2464 -- match (the source mentions T but the actual mentions T'class).
2469 Check_Mode_Conformant (New_S, Old_S);
2473 and then Error_Posted (New_S)
2475 Error_Msg_NE ("invalid actual subprogram: & #!", N, Old_S);
2479 if No (Rename_Spec) then
2481 -- The parameter profile of the new entity is that of the renamed
2482 -- entity: the subtypes given in the specification are irrelevant.
2484 Inherit_Renamed_Profile (New_S, Old_S);
2486 -- A call to the subprogram is transformed into a call to the
2487 -- renamed entity. This is transitive if the renamed entity is
2488 -- itself a renaming.
2490 if Present (Alias (Old_S)) then
2491 Set_Alias (New_S, Alias (Old_S));
2493 Set_Alias (New_S, Old_S);
2496 -- Note that we do not set Is_Intrinsic_Subprogram if we have a
2497 -- renaming as body, since the entity in this case is not an
2498 -- intrinsic (it calls an intrinsic, but we have a real body for
2499 -- this call, and it is in this body that the required intrinsic
2500 -- processing will take place).
2502 -- Also, if this is a renaming of inequality, the renamed operator
2503 -- is intrinsic, but what matters is the corresponding equality
2504 -- operator, which may be user-defined.
2506 Set_Is_Intrinsic_Subprogram
2508 Is_Intrinsic_Subprogram (Old_S)
2510 (Chars (Old_S) /= Name_Op_Ne
2511 or else Ekind (Old_S) = E_Operator
2513 Is_Intrinsic_Subprogram
2514 (Corresponding_Equality (Old_S))));
2516 if Ekind (Alias (New_S)) = E_Operator then
2517 Set_Has_Delayed_Freeze (New_S, False);
2520 -- If the renaming corresponds to an association for an abstract
2521 -- formal subprogram, then various attributes must be set to
2522 -- indicate that the renaming is an abstract dispatching operation
2523 -- with a controlling type.
2525 if Is_Actual and then Is_Abstract_Subprogram (Formal_Spec) then
2527 -- Mark the renaming as abstract here, so Find_Dispatching_Type
2528 -- see it as corresponding to a generic association for a
2529 -- formal abstract subprogram
2531 Set_Is_Abstract_Subprogram (New_S);
2534 New_S_Ctrl_Type : constant Entity_Id :=
2535 Find_Dispatching_Type (New_S);
2536 Old_S_Ctrl_Type : constant Entity_Id :=
2537 Find_Dispatching_Type (Old_S);
2540 if Old_S_Ctrl_Type /= New_S_Ctrl_Type then
2542 ("actual must be dispatching subprogram for type&",
2543 Nam, New_S_Ctrl_Type);
2546 Set_Is_Dispatching_Operation (New_S);
2547 Check_Controlling_Formals (New_S_Ctrl_Type, New_S);
2549 -- If the actual in the formal subprogram is itself a
2550 -- formal abstract subprogram association, there's no
2551 -- dispatch table component or position to inherit.
2553 if Present (DTC_Entity (Old_S)) then
2554 Set_DTC_Entity (New_S, DTC_Entity (Old_S));
2555 Set_DT_Position (New_S, DT_Position (Old_S));
2563 and then (Old_S = New_S
2564 or else (Nkind (Nam) /= N_Expanded_Name
2565 and then Chars (Old_S) = Chars (New_S)))
2567 Error_Msg_N ("subprogram cannot rename itself", N);
2570 Set_Convention (New_S, Convention (Old_S));
2572 if Is_Abstract_Subprogram (Old_S) then
2573 if Present (Rename_Spec) then
2575 ("a renaming-as-body cannot rename an abstract subprogram",
2577 Set_Has_Completion (Rename_Spec);
2579 Set_Is_Abstract_Subprogram (New_S);
2583 Check_Library_Unit_Renaming (N, Old_S);
2585 -- Pathological case: procedure renames entry in the scope of its
2586 -- task. Entry is given by simple name, but body must be built for
2587 -- procedure. Of course if called it will deadlock.
2589 if Ekind (Old_S) = E_Entry then
2590 Set_Has_Completion (New_S, False);
2591 Set_Alias (New_S, Empty);
2595 Freeze_Before (N, Old_S);
2596 Set_Has_Delayed_Freeze (New_S, False);
2597 Freeze_Before (N, New_S);
2599 -- An abstract subprogram is only allowed as an actual in the case
2600 -- where the formal subprogram is also abstract.
2602 if (Ekind (Old_S) = E_Procedure or else Ekind (Old_S) = E_Function)
2603 and then Is_Abstract_Subprogram (Old_S)
2604 and then not Is_Abstract_Subprogram (Formal_Spec)
2607 ("abstract subprogram not allowed as generic actual", Nam);
2612 -- A common error is to assume that implicit operators for types are
2613 -- defined in Standard, or in the scope of a subtype. In those cases
2614 -- where the renamed entity is given with an expanded name, it is
2615 -- worth mentioning that operators for the type are not declared in
2616 -- the scope given by the prefix.
2618 if Nkind (Nam) = N_Expanded_Name
2619 and then Nkind (Selector_Name (Nam)) = N_Operator_Symbol
2620 and then Scope (Entity (Nam)) = Standard_Standard
2623 T : constant Entity_Id :=
2624 Base_Type (Etype (First_Formal (New_S)));
2626 Error_Msg_Node_2 := Prefix (Nam);
2628 ("operator for type& is not declared in&", Prefix (Nam), T);
2633 ("no visible subprogram matches the specification for&",
2637 if Present (Candidate_Renaming) then
2644 F1 := First_Formal (Candidate_Renaming);
2645 F2 := First_Formal (New_S);
2646 T1 := First_Subtype (Etype (F1));
2648 while Present (F1) and then Present (F2) loop
2653 if Present (F1) and then Present (Default_Value (F1)) then
2654 if Present (Next_Formal (F1)) then
2656 ("\missing specification for &" &
2657 " and other formals with defaults", Spec, F1);
2660 ("\missing specification for &", Spec, F1);
2664 if Nkind (Nam) = N_Operator_Symbol
2665 and then From_Default (N)
2667 Error_Msg_Node_2 := T1;
2669 ("default & on & is not directly visible",
2676 -- Ada 2005 AI 404: if the new subprogram is dispatching, verify that
2677 -- controlling access parameters are known non-null for the renamed
2678 -- subprogram. Test also applies to a subprogram instantiation that
2679 -- is dispatching. Test is skipped if some previous error was detected
2680 -- that set Old_S to Any_Id.
2682 if Ada_Version >= Ada_2005
2683 and then Old_S /= Any_Id
2684 and then not Is_Dispatching_Operation (Old_S)
2685 and then Is_Dispatching_Operation (New_S)
2692 Old_F := First_Formal (Old_S);
2693 New_F := First_Formal (New_S);
2694 while Present (Old_F) loop
2695 if Ekind (Etype (Old_F)) = E_Anonymous_Access_Type
2696 and then Is_Controlling_Formal (New_F)
2697 and then not Can_Never_Be_Null (Old_F)
2699 Error_Msg_N ("access parameter is controlling,", New_F);
2701 ("\corresponding parameter of& "
2702 & "must be explicitly null excluding", New_F, Old_S);
2705 Next_Formal (Old_F);
2706 Next_Formal (New_F);
2711 -- A useful warning, suggested by Ada Bug Finder (Ada-Europe 2005)
2712 -- is to warn if an operator is being renamed as a different operator.
2713 -- If the operator is predefined, examine the kind of the entity, not
2714 -- the abbreviated declaration in Standard.
2716 if Comes_From_Source (N)
2717 and then Present (Old_S)
2719 (Nkind (Old_S) = N_Defining_Operator_Symbol
2720 or else Ekind (Old_S) = E_Operator)
2721 and then Nkind (New_S) = N_Defining_Operator_Symbol
2722 and then Chars (Old_S) /= Chars (New_S)
2725 ("?& is being renamed as a different operator", N, Old_S);
2728 -- Check for renaming of obsolescent subprogram
2730 Check_Obsolescent_2005_Entity (Entity (Nam), Nam);
2732 -- Another warning or some utility: if the new subprogram as the same
2733 -- name as the old one, the old one is not hidden by an outer homograph,
2734 -- the new one is not a public symbol, and the old one is otherwise
2735 -- directly visible, the renaming is superfluous.
2737 if Chars (Old_S) = Chars (New_S)
2738 and then Comes_From_Source (N)
2739 and then Scope (Old_S) /= Standard_Standard
2740 and then Warn_On_Redundant_Constructs
2742 (Is_Immediately_Visible (Old_S)
2743 or else Is_Potentially_Use_Visible (Old_S))
2744 and then Is_Overloadable (Current_Scope)
2745 and then Chars (Current_Scope) /= Chars (Old_S)
2748 ("?redundant renaming, entity is directly visible", Name (N));
2751 Ada_Version := Save_AV;
2752 Ada_Version_Explicit := Save_AV_Exp;
2753 end Analyze_Subprogram_Renaming;
2755 -------------------------
2756 -- Analyze_Use_Package --
2757 -------------------------
2759 -- Resolve the package names in the use clause, and make all the visible
2760 -- entities defined in the package potentially use-visible. If the package
2761 -- is already in use from a previous use clause, its visible entities are
2762 -- already use-visible. In that case, mark the occurrence as a redundant
2763 -- use. If the package is an open scope, i.e. if the use clause occurs
2764 -- within the package itself, ignore it.
2766 procedure Analyze_Use_Package (N : Node_Id) is
2767 Pack_Name : Node_Id;
2770 -- Start of processing for Analyze_Use_Package
2773 Check_SPARK_Restriction ("use clause is not allowed", N);
2775 Set_Hidden_By_Use_Clause (N, No_Elist);
2777 -- Use clause not allowed in a spec of a predefined package declaration
2778 -- except that packages whose file name starts a-n are OK (these are
2779 -- children of Ada.Numerics, which are never loaded by Rtsfind).
2781 if Is_Predefined_File_Name (Unit_File_Name (Current_Sem_Unit))
2782 and then Name_Buffer (1 .. 3) /= "a-n"
2784 Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Declaration
2786 Error_Msg_N ("use clause not allowed in predefined spec", N);
2789 -- Chain clause to list of use clauses in current scope
2791 if Nkind (Parent (N)) /= N_Compilation_Unit then
2792 Chain_Use_Clause (N);
2795 -- Loop through package names to identify referenced packages
2797 Pack_Name := First (Names (N));
2798 while Present (Pack_Name) loop
2799 Analyze (Pack_Name);
2801 if Nkind (Parent (N)) = N_Compilation_Unit
2802 and then Nkind (Pack_Name) = N_Expanded_Name
2808 Pref := Prefix (Pack_Name);
2809 while Nkind (Pref) = N_Expanded_Name loop
2810 Pref := Prefix (Pref);
2813 if Entity (Pref) = Standard_Standard then
2815 ("predefined package Standard cannot appear"
2816 & " in a context clause", Pref);
2824 -- Loop through package names to mark all entities as potentially
2827 Pack_Name := First (Names (N));
2828 while Present (Pack_Name) loop
2829 if Is_Entity_Name (Pack_Name) then
2830 Pack := Entity (Pack_Name);
2832 if Ekind (Pack) /= E_Package
2833 and then Etype (Pack) /= Any_Type
2835 if Ekind (Pack) = E_Generic_Package then
2836 Error_Msg_N -- CODEFIX
2837 ("a generic package is not allowed in a use clause",
2840 Error_Msg_N ("& is not a usable package", Pack_Name);
2844 if Nkind (Parent (N)) = N_Compilation_Unit then
2845 Check_In_Previous_With_Clause (N, Pack_Name);
2848 if Applicable_Use (Pack_Name) then
2849 Use_One_Package (Pack, N);
2853 -- Report error because name denotes something other than a package
2856 Error_Msg_N ("& is not a package", Pack_Name);
2861 end Analyze_Use_Package;
2863 ----------------------
2864 -- Analyze_Use_Type --
2865 ----------------------
2867 procedure Analyze_Use_Type (N : Node_Id) is
2872 Set_Hidden_By_Use_Clause (N, No_Elist);
2874 -- Chain clause to list of use clauses in current scope
2876 if Nkind (Parent (N)) /= N_Compilation_Unit then
2877 Chain_Use_Clause (N);
2880 -- If the Used_Operations list is already initialized, the clause has
2881 -- been analyzed previously, and it is begin reinstalled, for example
2882 -- when the clause appears in a package spec and we are compiling the
2883 -- corresponding package body. In that case, make the entities on the
2884 -- existing list use_visible, and mark the corresponding types In_Use.
2886 if Present (Used_Operations (N)) then
2892 Mark := First (Subtype_Marks (N));
2893 while Present (Mark) loop
2894 Use_One_Type (Mark, Installed => True);
2898 Elmt := First_Elmt (Used_Operations (N));
2899 while Present (Elmt) loop
2900 Set_Is_Potentially_Use_Visible (Node (Elmt));
2908 -- Otherwise, create new list and attach to it the operations that
2909 -- are made use-visible by the clause.
2911 Set_Used_Operations (N, New_Elmt_List);
2912 Id := First (Subtype_Marks (N));
2913 while Present (Id) loop
2917 if E /= Any_Type then
2920 if Nkind (Parent (N)) = N_Compilation_Unit then
2921 if Nkind (Id) = N_Identifier then
2922 Error_Msg_N ("type is not directly visible", Id);
2924 elsif Is_Child_Unit (Scope (E))
2925 and then Scope (E) /= System_Aux_Id
2927 Check_In_Previous_With_Clause (N, Prefix (Id));
2932 -- If the use_type_clause appears in a compilation unit context,
2933 -- check whether it comes from a unit that may appear in a
2934 -- limited_with_clause, for a better error message.
2936 if Nkind (Parent (N)) = N_Compilation_Unit
2937 and then Nkind (Id) /= N_Identifier
2943 function Mentioned (Nam : Node_Id) return Boolean;
2944 -- Check whether the prefix of expanded name for the type
2945 -- appears in the prefix of some limited_with_clause.
2951 function Mentioned (Nam : Node_Id) return Boolean is
2953 return Nkind (Name (Item)) = N_Selected_Component
2955 Chars (Prefix (Name (Item))) = Chars (Nam);
2959 Pref := Prefix (Id);
2960 Item := First (Context_Items (Parent (N)));
2962 while Present (Item) and then Item /= N loop
2963 if Nkind (Item) = N_With_Clause
2964 and then Limited_Present (Item)
2965 and then Mentioned (Pref)
2968 (Get_Msg_Id, "premature usage of incomplete type");
2979 end Analyze_Use_Type;
2981 --------------------
2982 -- Applicable_Use --
2983 --------------------
2985 function Applicable_Use (Pack_Name : Node_Id) return Boolean is
2986 Pack : constant Entity_Id := Entity (Pack_Name);
2989 if In_Open_Scopes (Pack) then
2990 if Warn_On_Redundant_Constructs
2991 and then Pack = Current_Scope
2993 Error_Msg_NE -- CODEFIX
2994 ("& is already use-visible within itself?", Pack_Name, Pack);
2999 elsif In_Use (Pack) then
3000 Note_Redundant_Use (Pack_Name);
3003 elsif Present (Renamed_Object (Pack))
3004 and then In_Use (Renamed_Object (Pack))
3006 Note_Redundant_Use (Pack_Name);
3014 ------------------------
3015 -- Attribute_Renaming --
3016 ------------------------
3018 procedure Attribute_Renaming (N : Node_Id) is
3019 Loc : constant Source_Ptr := Sloc (N);
3020 Nam : constant Node_Id := Name (N);
3021 Spec : constant Node_Id := Specification (N);
3022 New_S : constant Entity_Id := Defining_Unit_Name (Spec);
3023 Aname : constant Name_Id := Attribute_Name (Nam);
3025 Form_Num : Nat := 0;
3026 Expr_List : List_Id := No_List;
3028 Attr_Node : Node_Id;
3029 Body_Node : Node_Id;
3030 Param_Spec : Node_Id;
3033 Generate_Definition (New_S);
3035 -- This procedure is called in the context of subprogram renaming, and
3036 -- thus the attribute must be one that is a subprogram. All of those
3037 -- have at least one formal parameter, with the singular exception of
3038 -- AST_Entry (which is a real oddity, it is odd that this can be renamed
3041 if not Is_Non_Empty_List (Parameter_Specifications (Spec)) then
3042 if Aname /= Name_AST_Entry then
3044 ("subprogram renaming an attribute must have formals", N);
3049 Param_Spec := First (Parameter_Specifications (Spec));
3050 while Present (Param_Spec) loop
3051 Form_Num := Form_Num + 1;
3053 if Nkind (Parameter_Type (Param_Spec)) /= N_Access_Definition then
3054 Find_Type (Parameter_Type (Param_Spec));
3056 -- The profile of the new entity denotes the base type (s) of
3057 -- the types given in the specification. For access parameters
3058 -- there are no subtypes involved.
3060 Rewrite (Parameter_Type (Param_Spec),
3062 (Base_Type (Entity (Parameter_Type (Param_Spec))), Loc));
3065 if No (Expr_List) then
3066 Expr_List := New_List;
3069 Append_To (Expr_List,
3070 Make_Identifier (Loc,
3071 Chars => Chars (Defining_Identifier (Param_Spec))));
3073 -- The expressions in the attribute reference are not freeze
3074 -- points. Neither is the attribute as a whole, see below.
3076 Set_Must_Not_Freeze (Last (Expr_List));
3081 -- Immediate error if too many formals. Other mismatches in number or
3082 -- types of parameters are detected when we analyze the body of the
3083 -- subprogram that we construct.
3085 if Form_Num > 2 then
3086 Error_Msg_N ("too many formals for attribute", N);
3088 -- Error if the attribute reference has expressions that look like
3089 -- formal parameters.
3091 elsif Present (Expressions (Nam)) then
3092 Error_Msg_N ("illegal expressions in attribute reference", Nam);
3095 Aname = Name_Compose or else
3096 Aname = Name_Exponent or else
3097 Aname = Name_Leading_Part or else
3098 Aname = Name_Pos or else
3099 Aname = Name_Round or else
3100 Aname = Name_Scaling or else
3103 if Nkind (N) = N_Subprogram_Renaming_Declaration
3104 and then Present (Corresponding_Formal_Spec (N))
3107 ("generic actual cannot be attribute involving universal type",
3111 ("attribute involving a universal type cannot be renamed",
3116 -- AST_Entry is an odd case. It doesn't really make much sense to allow
3117 -- it to be renamed, but that's the DEC rule, so we have to do it right.
3118 -- The point is that the AST_Entry call should be made now, and what the
3119 -- function will return is the returned value.
3121 -- Note that there is no Expr_List in this case anyway
3123 if Aname = Name_AST_Entry then
3125 Ent : constant Entity_Id := Make_Temporary (Loc, 'R', Nam);
3130 Make_Object_Declaration (Loc,
3131 Defining_Identifier => Ent,
3132 Object_Definition =>
3133 New_Occurrence_Of (RTE (RE_AST_Handler), Loc),
3135 Constant_Present => True);
3137 Set_Assignment_OK (Decl, True);
3138 Insert_Action (N, Decl);
3139 Attr_Node := Make_Identifier (Loc, Chars (Ent));
3142 -- For all other attributes, we rewrite the attribute node to have
3143 -- a list of expressions corresponding to the subprogram formals.
3144 -- A renaming declaration is not a freeze point, and the analysis of
3145 -- the attribute reference should not freeze the type of the prefix.
3149 Make_Attribute_Reference (Loc,
3150 Prefix => Prefix (Nam),
3151 Attribute_Name => Aname,
3152 Expressions => Expr_List);
3154 Set_Must_Not_Freeze (Attr_Node);
3155 Set_Must_Not_Freeze (Prefix (Nam));
3158 -- Case of renaming a function
3160 if Nkind (Spec) = N_Function_Specification then
3161 if Is_Procedure_Attribute_Name (Aname) then
3162 Error_Msg_N ("attribute can only be renamed as procedure", Nam);
3166 Find_Type (Result_Definition (Spec));
3167 Rewrite (Result_Definition (Spec),
3169 Base_Type (Entity (Result_Definition (Spec))), Loc));
3172 Make_Subprogram_Body (Loc,
3173 Specification => Spec,
3174 Declarations => New_List,
3175 Handled_Statement_Sequence =>
3176 Make_Handled_Sequence_Of_Statements (Loc,
3177 Statements => New_List (
3178 Make_Simple_Return_Statement (Loc,
3179 Expression => Attr_Node))));
3181 -- Case of renaming a procedure
3184 if not Is_Procedure_Attribute_Name (Aname) then
3185 Error_Msg_N ("attribute can only be renamed as function", Nam);
3190 Make_Subprogram_Body (Loc,
3191 Specification => Spec,
3192 Declarations => New_List,
3193 Handled_Statement_Sequence =>
3194 Make_Handled_Sequence_Of_Statements (Loc,
3195 Statements => New_List (Attr_Node)));
3198 -- In case of tagged types we add the body of the generated function to
3199 -- the freezing actions of the type (because in the general case such
3200 -- type is still not frozen). We exclude from this processing generic
3201 -- formal subprograms found in instantiations and AST_Entry renamings.
3203 -- We must exclude VM targets because entity AST_Handler is defined in
3204 -- package System.Aux_Dec which is not available in those platforms.
3206 if VM_Target = No_VM
3207 and then not Present (Corresponding_Formal_Spec (N))
3208 and then Etype (Nam) /= RTE (RE_AST_Handler)
3211 P : constant Entity_Id := Prefix (Nam);
3216 if Is_Tagged_Type (Etype (P)) then
3217 Ensure_Freeze_Node (Etype (P));
3218 Append_Freeze_Action (Etype (P), Body_Node);
3220 Rewrite (N, Body_Node);
3222 Set_Etype (New_S, Base_Type (Etype (New_S)));
3226 -- Generic formal subprograms or AST_Handler renaming
3229 Rewrite (N, Body_Node);
3231 Set_Etype (New_S, Base_Type (Etype (New_S)));
3234 if Is_Compilation_Unit (New_S) then
3236 ("a library unit can only rename another library unit", N);
3239 -- We suppress elaboration warnings for the resulting entity, since
3240 -- clearly they are not needed, and more particularly, in the case
3241 -- of a generic formal subprogram, the resulting entity can appear
3242 -- after the instantiation itself, and thus look like a bogus case
3243 -- of access before elaboration.
3245 Set_Suppress_Elaboration_Warnings (New_S);
3247 end Attribute_Renaming;
3249 ----------------------
3250 -- Chain_Use_Clause --
3251 ----------------------
3253 procedure Chain_Use_Clause (N : Node_Id) is
3255 Level : Int := Scope_Stack.Last;
3258 if not Is_Compilation_Unit (Current_Scope)
3259 or else not Is_Child_Unit (Current_Scope)
3261 null; -- Common case
3263 elsif Defining_Entity (Parent (N)) = Current_Scope then
3264 null; -- Common case for compilation unit
3267 -- If declaration appears in some other scope, it must be in some
3268 -- parent unit when compiling a child.
3270 Pack := Defining_Entity (Parent (N));
3271 if not In_Open_Scopes (Pack) then
3272 null; -- default as well
3275 -- Find entry for parent unit in scope stack
3277 while Scope_Stack.Table (Level).Entity /= Pack loop
3283 Set_Next_Use_Clause (N,
3284 Scope_Stack.Table (Level).First_Use_Clause);
3285 Scope_Stack.Table (Level).First_Use_Clause := N;
3286 end Chain_Use_Clause;
3288 ---------------------------
3289 -- Check_Frozen_Renaming --
3290 ---------------------------
3292 procedure Check_Frozen_Renaming (N : Node_Id; Subp : Entity_Id) is
3298 and then not Has_Completion (Subp)
3302 (Parent (Declaration_Node (Subp)), Defining_Entity (N));
3304 if Is_Entity_Name (Name (N)) then
3305 Old_S := Entity (Name (N));
3307 if not Is_Frozen (Old_S)
3308 and then Operating_Mode /= Check_Semantics
3310 Append_Freeze_Action (Old_S, B_Node);
3312 Insert_After (N, B_Node);
3316 if Is_Intrinsic_Subprogram (Old_S)
3317 and then not In_Instance
3320 ("subprogram used in renaming_as_body cannot be intrinsic",
3325 Insert_After (N, B_Node);
3329 end Check_Frozen_Renaming;
3331 -------------------------------
3332 -- Set_Entity_Or_Discriminal --
3333 -------------------------------
3335 procedure Set_Entity_Or_Discriminal (N : Node_Id; E : Entity_Id) is
3339 -- If the entity is not a discriminant, or else expansion is disabled,
3340 -- simply set the entity.
3342 if not In_Spec_Expression
3343 or else Ekind (E) /= E_Discriminant
3344 or else Inside_A_Generic
3346 Set_Entity_With_Style_Check (N, E);
3348 -- The replacement of a discriminant by the corresponding discriminal
3349 -- is not done for a task discriminant that appears in a default
3350 -- expression of an entry parameter. See Exp_Ch2.Expand_Discriminant
3351 -- for details on their handling.
3353 elsif Is_Concurrent_Type (Scope (E)) then
3357 and then not Nkind_In (P, N_Parameter_Specification,
3358 N_Component_Declaration)
3364 and then Nkind (P) = N_Parameter_Specification
3369 Set_Entity (N, Discriminal (E));
3372 -- Otherwise, this is a discriminant in a context in which
3373 -- it is a reference to the corresponding parameter of the
3374 -- init proc for the enclosing type.
3377 Set_Entity (N, Discriminal (E));
3379 end Set_Entity_Or_Discriminal;
3381 -----------------------------------
3382 -- Check_In_Previous_With_Clause --
3383 -----------------------------------
3385 procedure Check_In_Previous_With_Clause
3389 Pack : constant Entity_Id := Entity (Original_Node (Nam));
3394 Item := First (Context_Items (Parent (N)));
3396 while Present (Item)
3399 if Nkind (Item) = N_With_Clause
3401 -- Protect the frontend against previous critical errors
3403 and then Nkind (Name (Item)) /= N_Selected_Component
3404 and then Entity (Name (Item)) = Pack
3408 -- Find root library unit in with_clause
3410 while Nkind (Par) = N_Expanded_Name loop
3411 Par := Prefix (Par);
3414 if Is_Child_Unit (Entity (Original_Node (Par))) then
3415 Error_Msg_NE ("& is not directly visible", Par, Entity (Par));
3424 -- On exit, package is not mentioned in a previous with_clause.
3425 -- Check if its prefix is.
3427 if Nkind (Nam) = N_Expanded_Name then
3428 Check_In_Previous_With_Clause (N, Prefix (Nam));
3430 elsif Pack /= Any_Id then
3431 Error_Msg_NE ("& is not visible", Nam, Pack);
3433 end Check_In_Previous_With_Clause;
3435 ---------------------------------
3436 -- Check_Library_Unit_Renaming --
3437 ---------------------------------
3439 procedure Check_Library_Unit_Renaming (N : Node_Id; Old_E : Entity_Id) is
3443 if Nkind (Parent (N)) /= N_Compilation_Unit then
3446 -- Check for library unit. Note that we used to check for the scope
3447 -- being Standard here, but that was wrong for Standard itself.
3449 elsif not Is_Compilation_Unit (Old_E)
3450 and then not Is_Child_Unit (Old_E)
3452 Error_Msg_N ("renamed unit must be a library unit", Name (N));
3454 -- Entities defined in Standard (operators and boolean literals) cannot
3455 -- be renamed as library units.
3457 elsif Scope (Old_E) = Standard_Standard
3458 and then Sloc (Old_E) = Standard_Location
3460 Error_Msg_N ("renamed unit must be a library unit", Name (N));
3462 elsif Present (Parent_Spec (N))
3463 and then Nkind (Unit (Parent_Spec (N))) = N_Generic_Package_Declaration
3464 and then not Is_Child_Unit (Old_E)
3467 ("renamed unit must be a child unit of generic parent", Name (N));
3469 elsif Nkind (N) in N_Generic_Renaming_Declaration
3470 and then Nkind (Name (N)) = N_Expanded_Name
3471 and then Is_Generic_Instance (Entity (Prefix (Name (N))))
3472 and then Is_Generic_Unit (Old_E)
3475 ("renamed generic unit must be a library unit", Name (N));
3477 elsif Is_Package_Or_Generic_Package (Old_E) then
3479 -- Inherit categorization flags
3481 New_E := Defining_Entity (N);
3482 Set_Is_Pure (New_E, Is_Pure (Old_E));
3483 Set_Is_Preelaborated (New_E, Is_Preelaborated (Old_E));
3484 Set_Is_Remote_Call_Interface (New_E,
3485 Is_Remote_Call_Interface (Old_E));
3486 Set_Is_Remote_Types (New_E, Is_Remote_Types (Old_E));
3487 Set_Is_Shared_Passive (New_E, Is_Shared_Passive (Old_E));
3489 end Check_Library_Unit_Renaming;
3495 procedure End_Scope is
3501 Id := First_Entity (Current_Scope);
3502 while Present (Id) loop
3503 -- An entity in the current scope is not necessarily the first one
3504 -- on its homonym chain. Find its predecessor if any,
3505 -- If it is an internal entity, it will not be in the visibility
3506 -- chain altogether, and there is nothing to unchain.
3508 if Id /= Current_Entity (Id) then
3509 Prev := Current_Entity (Id);
3510 while Present (Prev)
3511 and then Present (Homonym (Prev))
3512 and then Homonym (Prev) /= Id
3514 Prev := Homonym (Prev);
3517 -- Skip to end of loop if Id is not in the visibility chain
3519 if No (Prev) or else Homonym (Prev) /= Id then
3527 Set_Is_Immediately_Visible (Id, False);
3529 Outer := Homonym (Id);
3530 while Present (Outer) and then Scope (Outer) = Current_Scope loop
3531 Outer := Homonym (Outer);
3534 -- Reset homonym link of other entities, but do not modify link
3535 -- between entities in current scope, so that the back-end can have
3536 -- a proper count of local overloadings.
3539 Set_Name_Entity_Id (Chars (Id), Outer);
3541 elsif Scope (Prev) /= Scope (Id) then
3542 Set_Homonym (Prev, Outer);
3549 -- If the scope generated freeze actions, place them before the
3550 -- current declaration and analyze them. Type declarations and
3551 -- the bodies of initialization procedures can generate such nodes.
3552 -- We follow the parent chain until we reach a list node, which is
3553 -- the enclosing list of declarations. If the list appears within
3554 -- a protected definition, move freeze nodes outside the protected
3558 (Scope_Stack.Table (Scope_Stack.Last).Pending_Freeze_Actions)
3562 L : constant List_Id := Scope_Stack.Table
3563 (Scope_Stack.Last).Pending_Freeze_Actions;
3566 if Is_Itype (Current_Scope) then
3567 Decl := Associated_Node_For_Itype (Current_Scope);
3569 Decl := Parent (Current_Scope);
3574 while not (Is_List_Member (Decl))
3575 or else Nkind_In (Parent (Decl), N_Protected_Definition,
3578 Decl := Parent (Decl);
3581 Insert_List_Before_And_Analyze (Decl, L);
3590 ---------------------
3591 -- End_Use_Clauses --
3592 ---------------------
3594 procedure End_Use_Clauses (Clause : Node_Id) is
3598 -- Remove Use_Type clauses first, because they affect the
3599 -- visibility of operators in subsequent used packages.
3602 while Present (U) loop
3603 if Nkind (U) = N_Use_Type_Clause then
3607 Next_Use_Clause (U);
3611 while Present (U) loop
3612 if Nkind (U) = N_Use_Package_Clause then
3613 End_Use_Package (U);
3616 Next_Use_Clause (U);
3618 end End_Use_Clauses;
3620 ---------------------
3621 -- End_Use_Package --
3622 ---------------------
3624 procedure End_Use_Package (N : Node_Id) is
3625 Pack_Name : Node_Id;
3630 function Is_Primitive_Operator_In_Use
3632 F : Entity_Id) return Boolean;
3633 -- Check whether Op is a primitive operator of a use-visible type
3635 ----------------------------------
3636 -- Is_Primitive_Operator_In_Use --
3637 ----------------------------------
3639 function Is_Primitive_Operator_In_Use
3641 F : Entity_Id) return Boolean
3643 T : constant Entity_Id := Base_Type (Etype (F));
3645 return In_Use (T) and then Scope (T) = Scope (Op);
3646 end Is_Primitive_Operator_In_Use;
3648 -- Start of processing for End_Use_Package
3651 Pack_Name := First (Names (N));
3652 while Present (Pack_Name) loop
3654 -- Test that Pack_Name actually denotes a package before processing
3656 if Is_Entity_Name (Pack_Name)
3657 and then Ekind (Entity (Pack_Name)) = E_Package
3659 Pack := Entity (Pack_Name);
3661 if In_Open_Scopes (Pack) then
3664 elsif not Redundant_Use (Pack_Name) then
3665 Set_In_Use (Pack, False);
3666 Set_Current_Use_Clause (Pack, Empty);
3668 Id := First_Entity (Pack);
3669 while Present (Id) loop
3671 -- Preserve use-visibility of operators that are primitive
3672 -- operators of a type that is use-visible through an active
3675 if Nkind (Id) = N_Defining_Operator_Symbol
3677 (Is_Primitive_Operator_In_Use
3678 (Id, First_Formal (Id))
3680 (Present (Next_Formal (First_Formal (Id)))
3682 Is_Primitive_Operator_In_Use
3683 (Id, Next_Formal (First_Formal (Id)))))
3688 Set_Is_Potentially_Use_Visible (Id, False);
3691 if Is_Private_Type (Id)
3692 and then Present (Full_View (Id))
3694 Set_Is_Potentially_Use_Visible (Full_View (Id), False);
3700 if Present (Renamed_Object (Pack)) then
3701 Set_In_Use (Renamed_Object (Pack), False);
3702 Set_Current_Use_Clause (Renamed_Object (Pack), Empty);
3705 if Chars (Pack) = Name_System
3706 and then Scope (Pack) = Standard_Standard
3707 and then Present_System_Aux
3709 Id := First_Entity (System_Aux_Id);
3710 while Present (Id) loop
3711 Set_Is_Potentially_Use_Visible (Id, False);
3713 if Is_Private_Type (Id)
3714 and then Present (Full_View (Id))
3716 Set_Is_Potentially_Use_Visible (Full_View (Id), False);
3722 Set_In_Use (System_Aux_Id, False);
3726 Set_Redundant_Use (Pack_Name, False);
3733 if Present (Hidden_By_Use_Clause (N)) then
3734 Elmt := First_Elmt (Hidden_By_Use_Clause (N));
3735 while Present (Elmt) loop
3737 E : constant Entity_Id := Node (Elmt);
3740 -- Reset either Use_Visibility or Direct_Visibility, depending
3741 -- on how the entity was hidden by the use clause.
3743 if In_Use (Scope (E))
3744 and then Used_As_Generic_Actual (Scope (E))
3746 Set_Is_Potentially_Use_Visible (Node (Elmt));
3748 Set_Is_Immediately_Visible (Node (Elmt));
3755 Set_Hidden_By_Use_Clause (N, No_Elist);
3757 end End_Use_Package;
3763 procedure End_Use_Type (N : Node_Id) is
3768 -- Start of processing for End_Use_Type
3771 Id := First (Subtype_Marks (N));
3772 while Present (Id) loop
3774 -- A call to Rtsfind may occur while analyzing a use_type clause,
3775 -- in which case the type marks are not resolved yet, and there is
3776 -- nothing to remove.
3778 if not Is_Entity_Name (Id) or else No (Entity (Id)) then
3784 if T = Any_Type or else From_With_Type (T) then
3787 -- Note that the use_type clause may mention a subtype of the type
3788 -- whose primitive operations have been made visible. Here as
3789 -- elsewhere, it is the base type that matters for visibility.
3791 elsif In_Open_Scopes (Scope (Base_Type (T))) then
3794 elsif not Redundant_Use (Id) then
3795 Set_In_Use (T, False);
3796 Set_In_Use (Base_Type (T), False);
3797 Set_Current_Use_Clause (T, Empty);
3798 Set_Current_Use_Clause (Base_Type (T), Empty);
3805 if Is_Empty_Elmt_List (Used_Operations (N)) then
3809 Elmt := First_Elmt (Used_Operations (N));
3810 while Present (Elmt) loop
3811 Set_Is_Potentially_Use_Visible (Node (Elmt), False);
3817 ----------------------
3818 -- Find_Direct_Name --
3819 ----------------------
3821 procedure Find_Direct_Name (N : Node_Id) is
3826 Inst : Entity_Id := Empty;
3827 -- Enclosing instance, if any
3829 Homonyms : Entity_Id;
3830 -- Saves start of homonym chain
3832 Nvis_Entity : Boolean;
3833 -- Set True to indicate that there is at least one entity on the homonym
3834 -- chain which, while not visible, is visible enough from the user point
3835 -- of view to warrant an error message of "not visible" rather than
3838 Nvis_Is_Private_Subprg : Boolean := False;
3839 -- Ada 2005 (AI-262): Set True to indicate that a form of Beaujolais
3840 -- effect concerning library subprograms has been detected. Used to
3841 -- generate the precise error message.
3843 function From_Actual_Package (E : Entity_Id) return Boolean;
3844 -- Returns true if the entity is declared in a package that is
3845 -- an actual for a formal package of the current instance. Such an
3846 -- entity requires special handling because it may be use-visible
3847 -- but hides directly visible entities defined outside the instance.
3849 function Is_Actual_Parameter return Boolean;
3850 -- This function checks if the node N is an identifier that is an actual
3851 -- parameter of a procedure call. If so it returns True, otherwise it
3852 -- return False. The reason for this check is that at this stage we do
3853 -- not know what procedure is being called if the procedure might be
3854 -- overloaded, so it is premature to go setting referenced flags or
3855 -- making calls to Generate_Reference. We will wait till Resolve_Actuals
3856 -- for that processing
3858 function Known_But_Invisible (E : Entity_Id) return Boolean;
3859 -- This function determines whether the entity E (which is not
3860 -- visible) can reasonably be considered to be known to the writer
3861 -- of the reference. This is a heuristic test, used only for the
3862 -- purposes of figuring out whether we prefer to complain that an
3863 -- entity is undefined or invisible (and identify the declaration
3864 -- of the invisible entity in the latter case). The point here is
3865 -- that we don't want to complain that something is invisible and
3866 -- then point to something entirely mysterious to the writer.
3868 procedure Nvis_Messages;
3869 -- Called if there are no visible entries for N, but there is at least
3870 -- one non-directly visible, or hidden declaration. This procedure
3871 -- outputs an appropriate set of error messages.
3873 procedure Undefined (Nvis : Boolean);
3874 -- This function is called if the current node has no corresponding
3875 -- visible entity or entities. The value set in Msg indicates whether
3876 -- an error message was generated (multiple error messages for the
3877 -- same variable are generally suppressed, see body for details).
3878 -- Msg is True if an error message was generated, False if not. This
3879 -- value is used by the caller to determine whether or not to output
3880 -- additional messages where appropriate. The parameter is set False
3881 -- to get the message "X is undefined", and True to get the message
3882 -- "X is not visible".
3884 -------------------------
3885 -- From_Actual_Package --
3886 -------------------------
3888 function From_Actual_Package (E : Entity_Id) return Boolean is
3889 Scop : constant Entity_Id := Scope (E);
3893 if not In_Instance then
3896 Inst := Current_Scope;
3897 while Present (Inst)
3898 and then Ekind (Inst) /= E_Package
3899 and then not Is_Generic_Instance (Inst)
3901 Inst := Scope (Inst);
3908 Act := First_Entity (Inst);
3909 while Present (Act) loop
3910 if Ekind (Act) = E_Package then
3912 -- Check for end of actuals list
3914 if Renamed_Object (Act) = Inst then
3917 elsif Present (Associated_Formal_Package (Act))
3918 and then Renamed_Object (Act) = Scop
3920 -- Entity comes from (instance of) formal package
3935 end From_Actual_Package;
3937 -------------------------
3938 -- Is_Actual_Parameter --
3939 -------------------------
3941 function Is_Actual_Parameter return Boolean is
3944 Nkind (N) = N_Identifier
3946 (Nkind (Parent (N)) = N_Procedure_Call_Statement
3948 (Nkind (Parent (N)) = N_Parameter_Association
3949 and then N = Explicit_Actual_Parameter (Parent (N))
3950 and then Nkind (Parent (Parent (N))) =
3951 N_Procedure_Call_Statement));
3952 end Is_Actual_Parameter;
3954 -------------------------
3955 -- Known_But_Invisible --
3956 -------------------------
3958 function Known_But_Invisible (E : Entity_Id) return Boolean is
3959 Fname : File_Name_Type;
3962 -- Entities in Standard are always considered to be known
3964 if Sloc (E) <= Standard_Location then
3967 -- An entity that does not come from source is always considered
3968 -- to be unknown, since it is an artifact of code expansion.
3970 elsif not Comes_From_Source (E) then
3973 -- In gnat internal mode, we consider all entities known
3975 elsif GNAT_Mode then
3979 -- Here we have an entity that is not from package Standard, and
3980 -- which comes from Source. See if it comes from an internal file.
3982 Fname := Unit_File_Name (Get_Source_Unit (E));
3984 -- Case of from internal file
3986 if Is_Internal_File_Name (Fname) then
3988 -- Private part entities in internal files are never considered
3989 -- to be known to the writer of normal application code.
3991 if Is_Hidden (E) then
3995 -- Entities from System packages other than System and
3996 -- System.Storage_Elements are not considered to be known.
3997 -- System.Auxxxx files are also considered known to the user.
3999 -- Should refine this at some point to generally distinguish
4000 -- between known and unknown internal files ???
4002 Get_Name_String (Fname);
4007 Name_Buffer (1 .. 2) /= "s-"
4009 Name_Buffer (3 .. 8) = "stoele"
4011 Name_Buffer (3 .. 5) = "aux";
4013 -- If not an internal file, then entity is definitely known,
4014 -- even if it is in a private part (the message generated will
4015 -- note that it is in a private part)
4020 end Known_But_Invisible;
4026 procedure Nvis_Messages is
4027 Comp_Unit : Node_Id;
4029 Found : Boolean := False;
4030 Hidden : Boolean := False;
4034 -- Ada 2005 (AI-262): Generate a precise error concerning the
4035 -- Beaujolais effect that was previously detected
4037 if Nvis_Is_Private_Subprg then
4039 pragma Assert (Nkind (E2) = N_Defining_Identifier
4040 and then Ekind (E2) = E_Function
4041 and then Scope (E2) = Standard_Standard
4042 and then Has_Private_With (E2));
4044 -- Find the sloc corresponding to the private with'ed unit
4046 Comp_Unit := Cunit (Current_Sem_Unit);
4047 Error_Msg_Sloc := No_Location;
4049 Item := First (Context_Items (Comp_Unit));
4050 while Present (Item) loop
4051 if Nkind (Item) = N_With_Clause
4052 and then Private_Present (Item)
4053 and then Entity (Name (Item)) = E2
4055 Error_Msg_Sloc := Sloc (Item);
4062 pragma Assert (Error_Msg_Sloc /= No_Location);
4064 Error_Msg_N ("(Ada 2005): hidden by private with clause #", N);
4068 Undefined (Nvis => True);
4072 -- First loop does hidden declarations
4075 while Present (Ent) loop
4076 if Is_Potentially_Use_Visible (Ent) then
4078 Error_Msg_N -- CODEFIX
4079 ("multiple use clauses cause hiding!", N);
4083 Error_Msg_Sloc := Sloc (Ent);
4084 Error_Msg_N -- CODEFIX
4085 ("hidden declaration#!", N);
4088 Ent := Homonym (Ent);
4091 -- If we found hidden declarations, then that's enough, don't
4092 -- bother looking for non-visible declarations as well.
4098 -- Second loop does non-directly visible declarations
4101 while Present (Ent) loop
4102 if not Is_Potentially_Use_Visible (Ent) then
4104 -- Do not bother the user with unknown entities
4106 if not Known_But_Invisible (Ent) then
4110 Error_Msg_Sloc := Sloc (Ent);
4112 -- Output message noting that there is a non-visible
4113 -- declaration, distinguishing the private part case.
4115 if Is_Hidden (Ent) then
4116 Error_Msg_N ("non-visible (private) declaration#!", N);
4118 -- If the entity is declared in a generic package, it
4119 -- cannot be visible, so there is no point in adding it
4120 -- to the list of candidates if another homograph from a
4121 -- non-generic package has been seen.
4123 elsif Ekind (Scope (Ent)) = E_Generic_Package
4129 Error_Msg_N -- CODEFIX
4130 ("non-visible declaration#!", N);
4132 if Ekind (Scope (Ent)) /= E_Generic_Package then
4136 if Is_Compilation_Unit (Ent)
4138 Nkind (Parent (Parent (N))) = N_Use_Package_Clause
4140 Error_Msg_Qual_Level := 99;
4141 Error_Msg_NE -- CODEFIX
4142 ("\\missing `WITH &;`", N, Ent);
4143 Error_Msg_Qual_Level := 0;
4146 if Ekind (Ent) = E_Discriminant
4147 and then Present (Corresponding_Discriminant (Ent))
4148 and then Scope (Corresponding_Discriminant (Ent)) =
4152 ("inherited discriminant not allowed here" &
4153 " (RM 3.8 (12), 3.8.1 (6))!", N);
4157 -- Set entity and its containing package as referenced. We
4158 -- can't be sure of this, but this seems a better choice
4159 -- to avoid unused entity messages.
4161 if Comes_From_Source (Ent) then
4162 Set_Referenced (Ent);
4163 Set_Referenced (Cunit_Entity (Get_Source_Unit (Ent)));
4168 Ent := Homonym (Ent);
4177 procedure Undefined (Nvis : Boolean) is
4178 Emsg : Error_Msg_Id;
4181 -- We should never find an undefined internal name. If we do, then
4182 -- see if we have previous errors. If so, ignore on the grounds that
4183 -- it is probably a cascaded message (e.g. a block label from a badly
4184 -- formed block). If no previous errors, then we have a real internal
4185 -- error of some kind so raise an exception.
4187 if Is_Internal_Name (Chars (N)) then
4188 if Total_Errors_Detected /= 0 then
4191 raise Program_Error;
4195 -- A very specialized error check, if the undefined variable is
4196 -- a case tag, and the case type is an enumeration type, check
4197 -- for a possible misspelling, and if so, modify the identifier
4199 -- Named aggregate should also be handled similarly ???
4201 if Nkind (N) = N_Identifier
4202 and then Nkind (Parent (N)) = N_Case_Statement_Alternative
4205 Case_Stm : constant Node_Id := Parent (Parent (N));
4206 Case_Typ : constant Entity_Id := Etype (Expression (Case_Stm));
4211 if Is_Enumeration_Type (Case_Typ)
4212 and then not Is_Standard_Character_Type (Case_Typ)
4214 Lit := First_Literal (Case_Typ);
4215 Get_Name_String (Chars (Lit));
4217 if Chars (Lit) /= Chars (N)
4218 and then Is_Bad_Spelling_Of (Chars (N), Chars (Lit)) then
4219 Error_Msg_Node_2 := Lit;
4220 Error_Msg_N -- CODEFIX
4221 ("& is undefined, assume misspelling of &", N);
4222 Rewrite (N, New_Occurrence_Of (Lit, Sloc (N)));
4226 Lit := Next_Literal (Lit);
4231 -- Normal processing
4233 Set_Entity (N, Any_Id);
4234 Set_Etype (N, Any_Type);
4236 -- We use the table Urefs to keep track of entities for which we
4237 -- have issued errors for undefined references. Multiple errors
4238 -- for a single name are normally suppressed, however we modify
4239 -- the error message to alert the programmer to this effect.
4241 for J in Urefs.First .. Urefs.Last loop
4242 if Chars (N) = Chars (Urefs.Table (J).Node) then
4243 if Urefs.Table (J).Err /= No_Error_Msg
4244 and then Sloc (N) /= Urefs.Table (J).Loc
4246 Error_Msg_Node_1 := Urefs.Table (J).Node;
4248 if Urefs.Table (J).Nvis then
4249 Change_Error_Text (Urefs.Table (J).Err,
4250 "& is not visible (more references follow)");
4252 Change_Error_Text (Urefs.Table (J).Err,
4253 "& is undefined (more references follow)");
4256 Urefs.Table (J).Err := No_Error_Msg;
4259 -- Although we will set Msg False, and thus suppress the
4260 -- message, we also set Error_Posted True, to avoid any
4261 -- cascaded messages resulting from the undefined reference.
4264 Set_Error_Posted (N, True);
4269 -- If entry not found, this is first undefined occurrence
4272 Error_Msg_N ("& is not visible!", N);
4276 Error_Msg_N ("& is undefined!", N);
4279 -- A very bizarre special check, if the undefined identifier
4280 -- is put or put_line, then add a special error message (since
4281 -- this is a very common error for beginners to make).
4283 if Chars (N) = Name_Put or else Chars (N) = Name_Put_Line then
4284 Error_Msg_N -- CODEFIX
4285 ("\\possible missing `WITH Ada.Text_'I'O; " &
4286 "USE Ada.Text_'I'O`!", N);
4288 -- Another special check if N is the prefix of a selected
4289 -- component which is a known unit, add message complaining
4290 -- about missing with for this unit.
4292 elsif Nkind (Parent (N)) = N_Selected_Component
4293 and then N = Prefix (Parent (N))
4294 and then Is_Known_Unit (Parent (N))
4296 Error_Msg_Node_2 := Selector_Name (Parent (N));
4297 Error_Msg_N -- CODEFIX
4298 ("\\missing `WITH &.&;`", Prefix (Parent (N)));
4301 -- Now check for possible misspellings
4305 Ematch : Entity_Id := Empty;
4307 Last_Name_Id : constant Name_Id :=
4308 Name_Id (Nat (First_Name_Id) +
4309 Name_Entries_Count - 1);
4312 for Nam in First_Name_Id .. Last_Name_Id loop
4313 E := Get_Name_Entity_Id (Nam);
4316 and then (Is_Immediately_Visible (E)
4318 Is_Potentially_Use_Visible (E))
4320 if Is_Bad_Spelling_Of (Chars (N), Nam) then
4327 if Present (Ematch) then
4328 Error_Msg_NE -- CODEFIX
4329 ("\possible misspelling of&", N, Ematch);
4334 -- Make entry in undefined references table unless the full errors
4335 -- switch is set, in which case by refraining from generating the
4336 -- table entry, we guarantee that we get an error message for every
4337 -- undefined reference.
4339 if not All_Errors_Mode then
4350 -- Start of processing for Find_Direct_Name
4353 -- If the entity pointer is already set, this is an internal node, or
4354 -- a node that is analyzed more than once, after a tree modification.
4355 -- In such a case there is no resolution to perform, just set the type.
4357 if Present (Entity (N)) then
4358 if Is_Type (Entity (N)) then
4359 Set_Etype (N, Entity (N));
4363 Entyp : constant Entity_Id := Etype (Entity (N));
4366 -- One special case here. If the Etype field is already set,
4367 -- and references the packed array type corresponding to the
4368 -- etype of the referenced entity, then leave it alone. This
4369 -- happens for trees generated from Exp_Pakd, where expressions
4370 -- can be deliberately "mis-typed" to the packed array type.
4372 if Is_Array_Type (Entyp)
4373 and then Is_Packed (Entyp)
4374 and then Present (Etype (N))
4375 and then Etype (N) = Packed_Array_Type (Entyp)
4379 -- If not that special case, then just reset the Etype
4382 Set_Etype (N, Etype (Entity (N)));
4390 -- Here if Entity pointer was not set, we need full visibility analysis
4391 -- First we generate debugging output if the debug E flag is set.
4393 if Debug_Flag_E then
4394 Write_Str ("Looking for ");
4395 Write_Name (Chars (N));
4399 Homonyms := Current_Entity (N);
4400 Nvis_Entity := False;
4403 while Present (E) loop
4405 -- If entity is immediately visible or potentially use visible, then
4406 -- process the entity and we are done.
4408 if Is_Immediately_Visible (E) then
4409 goto Immediately_Visible_Entity;
4411 elsif Is_Potentially_Use_Visible (E) then
4412 goto Potentially_Use_Visible_Entity;
4414 -- Note if a known but invisible entity encountered
4416 elsif Known_But_Invisible (E) then
4417 Nvis_Entity := True;
4420 -- Move to next entity in chain and continue search
4425 -- If no entries on homonym chain that were potentially visible,
4426 -- and no entities reasonably considered as non-visible, then
4427 -- we have a plain undefined reference, with no additional
4428 -- explanation required!
4430 if not Nvis_Entity then
4431 Undefined (Nvis => False);
4433 -- Otherwise there is at least one entry on the homonym chain that
4434 -- is reasonably considered as being known and non-visible.
4442 -- Processing for a potentially use visible entry found. We must search
4443 -- the rest of the homonym chain for two reasons. First, if there is a
4444 -- directly visible entry, then none of the potentially use-visible
4445 -- entities are directly visible (RM 8.4(10)). Second, we need to check
4446 -- for the case of multiple potentially use-visible entries hiding one
4447 -- another and as a result being non-directly visible (RM 8.4(11)).
4449 <<Potentially_Use_Visible_Entity>> declare
4450 Only_One_Visible : Boolean := True;
4451 All_Overloadable : Boolean := Is_Overloadable (E);
4455 while Present (E2) loop
4456 if Is_Immediately_Visible (E2) then
4458 -- If the use-visible entity comes from the actual for a
4459 -- formal package, it hides a directly visible entity from
4460 -- outside the instance.
4462 if From_Actual_Package (E)
4463 and then Scope_Depth (E2) < Scope_Depth (Inst)
4468 goto Immediately_Visible_Entity;
4471 elsif Is_Potentially_Use_Visible (E2) then
4472 Only_One_Visible := False;
4473 All_Overloadable := All_Overloadable and Is_Overloadable (E2);
4475 -- Ada 2005 (AI-262): Protect against a form of Beaujolais effect
4476 -- that can occur in private_with clauses. Example:
4479 -- private with B; package A is
4480 -- package C is function B return Integer;
4482 -- V1 : Integer := B;
4483 -- private function B return Integer;
4484 -- V2 : Integer := B;
4487 -- V1 resolves to A.B, but V2 resolves to library unit B
4489 elsif Ekind (E2) = E_Function
4490 and then Scope (E2) = Standard_Standard
4491 and then Has_Private_With (E2)
4493 Only_One_Visible := False;
4494 All_Overloadable := False;
4495 Nvis_Is_Private_Subprg := True;
4502 -- On falling through this loop, we have checked that there are no
4503 -- immediately visible entities. Only_One_Visible is set if exactly
4504 -- one potentially use visible entity exists. All_Overloadable is
4505 -- set if all the potentially use visible entities are overloadable.
4506 -- The condition for legality is that either there is one potentially
4507 -- use visible entity, or if there is more than one, then all of them
4508 -- are overloadable.
4510 if Only_One_Visible or All_Overloadable then
4513 -- If there is more than one potentially use-visible entity and at
4514 -- least one of them non-overloadable, we have an error (RM 8.4(11).
4515 -- Note that E points to the first such entity on the homonym list.
4516 -- Special case: if one of the entities is declared in an actual
4517 -- package, it was visible in the generic, and takes precedence over
4518 -- other entities that are potentially use-visible. Same if it is
4519 -- declared in a local instantiation of the current instance.
4524 -- Find current instance
4526 Inst := Current_Scope;
4527 while Present (Inst)
4528 and then Inst /= Standard_Standard
4530 if Is_Generic_Instance (Inst) then
4534 Inst := Scope (Inst);
4538 while Present (E2) loop
4539 if From_Actual_Package (E2)
4541 (Is_Generic_Instance (Scope (E2))
4542 and then Scope_Depth (Scope (E2)) > Scope_Depth (Inst))
4555 Is_Predefined_File_Name (Unit_File_Name (Current_Sem_Unit))
4557 -- A use-clause in the body of a system file creates conflict
4558 -- with some entity in a user scope, while rtsfind is active.
4559 -- Keep only the entity coming from another predefined unit.
4562 while Present (E2) loop
4563 if Is_Predefined_File_Name
4564 (Unit_File_Name (Get_Source_Unit (Sloc (E2))))
4573 -- Entity must exist because predefined unit is correct
4575 raise Program_Error;
4584 -- Come here with E set to the first immediately visible entity on
4585 -- the homonym chain. This is the one we want unless there is another
4586 -- immediately visible entity further on in the chain for an inner
4587 -- scope (RM 8.3(8)).
4589 <<Immediately_Visible_Entity>> declare
4594 -- Find scope level of initial entity. When compiling through
4595 -- Rtsfind, the previous context is not completely invisible, and
4596 -- an outer entity may appear on the chain, whose scope is below
4597 -- the entry for Standard that delimits the current scope stack.
4598 -- Indicate that the level for this spurious entry is outside of
4599 -- the current scope stack.
4601 Level := Scope_Stack.Last;
4603 Scop := Scope_Stack.Table (Level).Entity;
4604 exit when Scop = Scope (E);
4606 exit when Scop = Standard_Standard;
4609 -- Now search remainder of homonym chain for more inner entry
4610 -- If the entity is Standard itself, it has no scope, and we
4611 -- compare it with the stack entry directly.
4614 while Present (E2) loop
4615 if Is_Immediately_Visible (E2) then
4617 -- If a generic package contains a local declaration that
4618 -- has the same name as the generic, there may be a visibility
4619 -- conflict in an instance, where the local declaration must
4620 -- also hide the name of the corresponding package renaming.
4621 -- We check explicitly for a package declared by a renaming,
4622 -- whose renamed entity is an instance that is on the scope
4623 -- stack, and that contains a homonym in the same scope. Once
4624 -- we have found it, we know that the package renaming is not
4625 -- immediately visible, and that the identifier denotes the
4626 -- other entity (and its homonyms if overloaded).
4628 if Scope (E) = Scope (E2)
4629 and then Ekind (E) = E_Package
4630 and then Present (Renamed_Object (E))
4631 and then Is_Generic_Instance (Renamed_Object (E))
4632 and then In_Open_Scopes (Renamed_Object (E))
4633 and then Comes_From_Source (N)
4635 Set_Is_Immediately_Visible (E, False);
4639 for J in Level + 1 .. Scope_Stack.Last loop
4640 if Scope_Stack.Table (J).Entity = Scope (E2)
4641 or else Scope_Stack.Table (J).Entity = E2
4654 -- At the end of that loop, E is the innermost immediately
4655 -- visible entity, so we are all set.
4658 -- Come here with entity found, and stored in E
4662 -- Check violation of No_Wide_Characters restriction
4664 Check_Wide_Character_Restriction (E, N);
4666 -- When distribution features are available (Get_PCS_Name /=
4667 -- Name_No_DSA), a remote access-to-subprogram type is converted
4668 -- into a record type holding whatever information is needed to
4669 -- perform a remote call on an RCI subprogram. In that case we
4670 -- rewrite any occurrence of the RAS type into the equivalent record
4671 -- type here. 'Access attribute references and RAS dereferences are
4672 -- then implemented using specific TSSs. However when distribution is
4673 -- not available (case of Get_PCS_Name = Name_No_DSA), we bypass the
4674 -- generation of these TSSs, and we must keep the RAS type in its
4675 -- original access-to-subprogram form (since all calls through a
4676 -- value of such type will be local anyway in the absence of a PCS).
4678 if Comes_From_Source (N)
4679 and then Is_Remote_Access_To_Subprogram_Type (E)
4680 and then Expander_Active
4681 and then Get_PCS_Name /= Name_No_DSA
4684 New_Occurrence_Of (Equivalent_Type (E), Sloc (N)));
4688 -- Set the entity. Note that the reason we call Set_Entity for the
4689 -- overloadable case, as opposed to Set_Entity_With_Style_Check is
4690 -- that in the overloaded case, the initial call can set the wrong
4691 -- homonym. The call that sets the right homonym is in Sem_Res and
4692 -- that call does use Set_Entity_With_Style_Check, so we don't miss
4695 if Is_Overloadable (E) then
4698 Set_Entity_With_Style_Check (N, E);
4704 Set_Etype (N, Get_Full_View (Etype (E)));
4707 if Debug_Flag_E then
4708 Write_Str (" found ");
4709 Write_Entity_Info (E, " ");
4712 -- If the Ekind of the entity is Void, it means that all homonyms
4713 -- are hidden from all visibility (RM 8.3(5,14-20)). However, this
4714 -- test is skipped if the current scope is a record and the name is
4715 -- a pragma argument expression (case of Atomic and Volatile pragmas
4716 -- and possibly other similar pragmas added later, which are allowed
4717 -- to reference components in the current record).
4719 if Ekind (E) = E_Void
4721 (not Is_Record_Type (Current_Scope)
4722 or else Nkind (Parent (N)) /= N_Pragma_Argument_Association)
4724 Premature_Usage (N);
4726 -- If the entity is overloadable, collect all interpretations of the
4727 -- name for subsequent overload resolution. We optimize a bit here to
4728 -- do this only if we have an overloadable entity that is not on its
4729 -- own on the homonym chain.
4731 elsif Is_Overloadable (E)
4732 and then (Present (Homonym (E)) or else Current_Entity (N) /= E)
4734 Collect_Interps (N);
4736 -- If no homonyms were visible, the entity is unambiguous
4738 if not Is_Overloaded (N) then
4739 if not Is_Actual_Parameter then
4740 Generate_Reference (E, N);
4744 -- Case of non-overloadable entity, set the entity providing that
4745 -- we do not have the case of a discriminant reference within a
4746 -- default expression. Such references are replaced with the
4747 -- corresponding discriminal, which is the formal corresponding to
4748 -- to the discriminant in the initialization procedure.
4751 -- Entity is unambiguous, indicate that it is referenced here
4753 -- For a renaming of an object, always generate simple reference,
4754 -- we don't try to keep track of assignments in this case.
4756 if Is_Object (E) and then Present (Renamed_Object (E)) then
4757 Generate_Reference (E, N);
4759 -- If the renamed entity is a private protected component,
4760 -- reference the original component as well. This needs to be
4761 -- done because the private renamings are installed before any
4762 -- analysis has occurred. Reference to a private component will
4763 -- resolve to the renaming and the original component will be
4764 -- left unreferenced, hence the following.
4766 if Is_Prival (E) then
4767 Generate_Reference (Prival_Link (E), N);
4770 -- One odd case is that we do not want to set the Referenced flag
4771 -- if the entity is a label, and the identifier is the label in
4772 -- the source, since this is not a reference from the point of
4773 -- view of the user.
4775 elsif Nkind (Parent (N)) = N_Label then
4777 R : constant Boolean := Referenced (E);
4780 -- Generate reference unless this is an actual parameter
4781 -- (see comment below)
4783 if Is_Actual_Parameter then
4784 Generate_Reference (E, N);
4785 Set_Referenced (E, R);
4789 -- Normal case, not a label: generate reference
4791 -- ??? It is too early to generate a reference here even if the
4792 -- entity is unambiguous, because the tree is not sufficiently
4793 -- typed at this point for Generate_Reference to determine
4794 -- whether this reference modifies the denoted object (because
4795 -- implicit dereferences cannot be identified prior to full type
4798 -- The Is_Actual_Parameter routine takes care of one of these
4799 -- cases but there are others probably ???
4801 -- If the entity is the LHS of an assignment, and is a variable
4802 -- (rather than a package prefix), we can mark it as a
4803 -- modification right away, to avoid duplicate references.
4806 if not Is_Actual_Parameter then
4808 and then Ekind (E) /= E_Package
4809 and then Ekind (E) /= E_Generic_Package
4811 Generate_Reference (E, N, 'm');
4813 Generate_Reference (E, N);
4817 Check_Nested_Access (E);
4820 Set_Entity_Or_Discriminal (N, E);
4821 Check_Implicit_Dereference (N, Etype (E));
4824 end Find_Direct_Name;
4826 ------------------------
4827 -- Find_Expanded_Name --
4828 ------------------------
4830 -- This routine searches the homonym chain of the entity until it finds
4831 -- an entity declared in the scope denoted by the prefix. If the entity
4832 -- is private, it may nevertheless be immediately visible, if we are in
4833 -- the scope of its declaration.
4835 procedure Find_Expanded_Name (N : Node_Id) is
4836 Selector : constant Node_Id := Selector_Name (N);
4837 Candidate : Entity_Id := Empty;
4843 P_Name := Entity (Prefix (N));
4846 -- If the prefix is a renamed package, look for the entity in the
4847 -- original package.
4849 if Ekind (P_Name) = E_Package
4850 and then Present (Renamed_Object (P_Name))
4852 P_Name := Renamed_Object (P_Name);
4854 -- Rewrite node with entity field pointing to renamed object
4856 Rewrite (Prefix (N), New_Copy (Prefix (N)));
4857 Set_Entity (Prefix (N), P_Name);
4859 -- If the prefix is an object of a concurrent type, look for
4860 -- the entity in the associated task or protected type.
4862 elsif Is_Concurrent_Type (Etype (P_Name)) then
4863 P_Name := Etype (P_Name);
4866 Id := Current_Entity (Selector);
4869 Is_New_Candidate : Boolean;
4872 while Present (Id) loop
4873 if Scope (Id) = P_Name then
4875 Is_New_Candidate := True;
4877 -- Ada 2005 (AI-217): Handle shadow entities associated with types
4878 -- declared in limited-withed nested packages. We don't need to
4879 -- handle E_Incomplete_Subtype entities because the entities in
4880 -- the limited view are always E_Incomplete_Type entities (see
4881 -- Build_Limited_Views). Regarding the expression used to evaluate
4882 -- the scope, it is important to note that the limited view also
4883 -- has shadow entities associated nested packages. For this reason
4884 -- the correct scope of the entity is the scope of the real entity
4885 -- The non-limited view may itself be incomplete, in which case
4886 -- get the full view if available.
4888 elsif From_With_Type (Id)
4889 and then Is_Type (Id)
4890 and then Ekind (Id) = E_Incomplete_Type
4891 and then Present (Non_Limited_View (Id))
4892 and then Scope (Non_Limited_View (Id)) = P_Name
4894 Candidate := Get_Full_View (Non_Limited_View (Id));
4895 Is_New_Candidate := True;
4898 Is_New_Candidate := False;
4901 if Is_New_Candidate then
4902 if Is_Child_Unit (Id) then
4903 exit when Is_Visible_Child_Unit (Id)
4904 or else Is_Immediately_Visible (Id);
4907 exit when not Is_Hidden (Id)
4908 or else Is_Immediately_Visible (Id);
4917 and then (Ekind (P_Name) = E_Procedure
4919 Ekind (P_Name) = E_Function)
4920 and then Is_Generic_Instance (P_Name)
4922 -- Expanded name denotes entity in (instance of) generic subprogram.
4923 -- The entity may be in the subprogram instance, or may denote one of
4924 -- the formals, which is declared in the enclosing wrapper package.
4926 P_Name := Scope (P_Name);
4928 Id := Current_Entity (Selector);
4929 while Present (Id) loop
4930 exit when Scope (Id) = P_Name;
4935 if No (Id) or else Chars (Id) /= Chars (Selector) then
4936 Set_Etype (N, Any_Type);
4938 -- If we are looking for an entity defined in System, try to find it
4939 -- in the child package that may have been provided as an extension
4940 -- to System. The Extend_System pragma will have supplied the name of
4941 -- the extension, which may have to be loaded.
4943 if Chars (P_Name) = Name_System
4944 and then Scope (P_Name) = Standard_Standard
4945 and then Present (System_Extend_Unit)
4946 and then Present_System_Aux (N)
4948 Set_Entity (Prefix (N), System_Aux_Id);
4949 Find_Expanded_Name (N);
4952 elsif Nkind (Selector) = N_Operator_Symbol
4953 and then Has_Implicit_Operator (N)
4955 -- There is an implicit instance of the predefined operator in
4956 -- the given scope. The operator entity is defined in Standard.
4957 -- Has_Implicit_Operator makes the node into an Expanded_Name.
4961 elsif Nkind (Selector) = N_Character_Literal
4962 and then Has_Implicit_Character_Literal (N)
4964 -- If there is no literal defined in the scope denoted by the
4965 -- prefix, the literal may belong to (a type derived from)
4966 -- Standard_Character, for which we have no explicit literals.
4971 -- If the prefix is a single concurrent object, use its name in
4972 -- the error message, rather than that of the anonymous type.
4974 if Is_Concurrent_Type (P_Name)
4975 and then Is_Internal_Name (Chars (P_Name))
4977 Error_Msg_Node_2 := Entity (Prefix (N));
4979 Error_Msg_Node_2 := P_Name;
4982 if P_Name = System_Aux_Id then
4983 P_Name := Scope (P_Name);
4984 Set_Entity (Prefix (N), P_Name);
4987 if Present (Candidate) then
4989 -- If we know that the unit is a child unit we can give a more
4990 -- accurate error message.
4992 if Is_Child_Unit (Candidate) then
4994 -- If the candidate is a private child unit and we are in
4995 -- the visible part of a public unit, specialize the error
4996 -- message. There might be a private with_clause for it,
4997 -- but it is not currently active.
4999 if Is_Private_Descendant (Candidate)
5000 and then Ekind (Current_Scope) = E_Package
5001 and then not In_Private_Part (Current_Scope)
5002 and then not Is_Private_Descendant (Current_Scope)
5004 Error_Msg_N ("private child unit& is not visible here",
5007 -- Normal case where we have a missing with for a child unit
5010 Error_Msg_Qual_Level := 99;
5011 Error_Msg_NE -- CODEFIX
5012 ("missing `WITH &;`", Selector, Candidate);
5013 Error_Msg_Qual_Level := 0;
5016 -- Here we don't know that this is a child unit
5019 Error_Msg_NE ("& is not a visible entity of&", N, Selector);
5023 -- Within the instantiation of a child unit, the prefix may
5024 -- denote the parent instance, but the selector has the name
5025 -- of the original child. Find whether we are within the
5026 -- corresponding instance, and get the proper entity, which
5027 -- can only be an enclosing scope.
5030 and then In_Open_Scopes (P_Name)
5031 and then Is_Generic_Instance (P_Name)
5034 S : Entity_Id := Current_Scope;
5038 for J in reverse 0 .. Scope_Stack.Last loop
5039 S := Scope_Stack.Table (J).Entity;
5041 exit when S = Standard_Standard;
5043 if Ekind_In (S, E_Function,
5047 P := Generic_Parent (Specification
5048 (Unit_Declaration_Node (S)));
5051 and then Chars (Scope (P)) = Chars (O_Name)
5052 and then Chars (P) = Chars (Selector)
5063 -- If this is a selection from Ada, System or Interfaces, then
5064 -- we assume a missing with for the corresponding package.
5066 if Is_Known_Unit (N) then
5067 if not Error_Posted (N) then
5068 Error_Msg_Node_2 := Selector;
5069 Error_Msg_N -- CODEFIX
5070 ("missing `WITH &.&;`", Prefix (N));
5073 -- If this is a selection from a dummy package, then suppress
5074 -- the error message, of course the entity is missing if the
5075 -- package is missing!
5077 elsif Sloc (Error_Msg_Node_2) = No_Location then
5080 -- Here we have the case of an undefined component
5084 -- The prefix may hide a homonym in the context that
5085 -- declares the desired entity. This error can use a
5086 -- specialized message.
5088 if In_Open_Scopes (P_Name)
5089 and then Present (Homonym (P_Name))
5090 and then Is_Compilation_Unit (Homonym (P_Name))
5092 (Is_Immediately_Visible (Homonym (P_Name))
5093 or else Is_Visible_Child_Unit (Homonym (P_Name)))
5096 H : constant Entity_Id := Homonym (P_Name);
5099 Id := First_Entity (H);
5100 while Present (Id) loop
5101 if Chars (Id) = Chars (Selector) then
5102 Error_Msg_Qual_Level := 99;
5103 Error_Msg_Name_1 := Chars (Selector);
5105 ("% not declared in&", N, P_Name);
5107 ("\use fully qualified name starting with"
5108 & " Standard to make& visible", N, H);
5109 Error_Msg_Qual_Level := 0;
5116 -- If not found, standard error message.
5118 Error_Msg_NE ("& not declared in&", N, Selector);
5124 Error_Msg_NE ("& not declared in&", N, Selector);
5127 -- Check for misspelling of some entity in prefix
5129 Id := First_Entity (P_Name);
5130 while Present (Id) loop
5131 if Is_Bad_Spelling_Of (Chars (Id), Chars (Selector))
5132 and then not Is_Internal_Name (Chars (Id))
5134 Error_Msg_NE -- CODEFIX
5135 ("possible misspelling of&", Selector, Id);
5142 -- Specialize the message if this may be an instantiation
5143 -- of a child unit that was not mentioned in the context.
5145 if Nkind (Parent (N)) = N_Package_Instantiation
5146 and then Is_Generic_Instance (Entity (Prefix (N)))
5147 and then Is_Compilation_Unit
5148 (Generic_Parent (Parent (Entity (Prefix (N)))))
5150 Error_Msg_Node_2 := Selector;
5151 Error_Msg_N -- CODEFIX
5152 ("\missing `WITH &.&;`", Prefix (N));
5162 if Comes_From_Source (N)
5163 and then Is_Remote_Access_To_Subprogram_Type (Id)
5164 and then Present (Equivalent_Type (Id))
5166 -- If we are not actually generating distribution code (i.e. the
5167 -- current PCS is the dummy non-distributed version), then the
5168 -- Equivalent_Type will be missing, and Id should be treated as
5169 -- a regular access-to-subprogram type.
5171 Id := Equivalent_Type (Id);
5172 Set_Chars (Selector, Chars (Id));
5175 -- Ada 2005 (AI-50217): Check usage of entities in limited withed units
5177 if Ekind (P_Name) = E_Package
5178 and then From_With_Type (P_Name)
5180 if From_With_Type (Id)
5181 or else Is_Type (Id)
5182 or else Ekind (Id) = E_Package
5187 ("limited withed package can only be used to access "
5188 & "incomplete types",
5193 if Is_Task_Type (P_Name)
5194 and then ((Ekind (Id) = E_Entry
5195 and then Nkind (Parent (N)) /= N_Attribute_Reference)
5197 (Ekind (Id) = E_Entry_Family
5199 Nkind (Parent (Parent (N))) /= N_Attribute_Reference))
5201 -- It is an entry call after all, either to the current task (which
5202 -- will deadlock) or to an enclosing task.
5204 Analyze_Selected_Component (N);
5208 Change_Selected_Component_To_Expanded_Name (N);
5210 -- Do style check and generate reference, but skip both steps if this
5211 -- entity has homonyms, since we may not have the right homonym set yet.
5212 -- The proper homonym will be set during the resolve phase.
5214 if Has_Homonym (Id) then
5217 Set_Entity_Or_Discriminal (N, Id);
5220 Generate_Reference (Id, N, 'm');
5222 Generate_Reference (Id, N);
5226 if Is_Type (Id) then
5229 Set_Etype (N, Get_Full_View (Etype (Id)));
5232 -- Check for violation of No_Wide_Characters
5234 Check_Wide_Character_Restriction (Id, N);
5236 -- If the Ekind of the entity is Void, it means that all homonyms are
5237 -- hidden from all visibility (RM 8.3(5,14-20)).
5239 if Ekind (Id) = E_Void then
5240 Premature_Usage (N);
5242 elsif Is_Overloadable (Id)
5243 and then Present (Homonym (Id))
5246 H : Entity_Id := Homonym (Id);
5249 while Present (H) loop
5250 if Scope (H) = Scope (Id)
5253 or else Is_Immediately_Visible (H))
5255 Collect_Interps (N);
5262 -- If an extension of System is present, collect possible explicit
5263 -- overloadings declared in the extension.
5265 if Chars (P_Name) = Name_System
5266 and then Scope (P_Name) = Standard_Standard
5267 and then Present (System_Extend_Unit)
5268 and then Present_System_Aux (N)
5270 H := Current_Entity (Id);
5272 while Present (H) loop
5273 if Scope (H) = System_Aux_Id then
5274 Add_One_Interp (N, H, Etype (H));
5283 if Nkind (Selector_Name (N)) = N_Operator_Symbol
5284 and then Scope (Id) /= Standard_Standard
5286 -- In addition to user-defined operators in the given scope, there
5287 -- may be an implicit instance of the predefined operator. The
5288 -- operator (defined in Standard) is found in Has_Implicit_Operator,
5289 -- and added to the interpretations. Procedure Add_One_Interp will
5290 -- determine which hides which.
5292 if Has_Implicit_Operator (N) then
5296 end Find_Expanded_Name;
5298 -------------------------
5299 -- Find_Renamed_Entity --
5300 -------------------------
5302 function Find_Renamed_Entity
5306 Is_Actual : Boolean := False) return Entity_Id
5309 I1 : Interp_Index := 0; -- Suppress junk warnings
5315 function Enclosing_Instance return Entity_Id;
5316 -- If the renaming determines the entity for the default of a formal
5317 -- subprogram nested within another instance, choose the innermost
5318 -- candidate. This is because if the formal has a box, and we are within
5319 -- an enclosing instance where some candidate interpretations are local
5320 -- to this enclosing instance, we know that the default was properly
5321 -- resolved when analyzing the generic, so we prefer the local
5322 -- candidates to those that are external. This is not always the case
5323 -- but is a reasonable heuristic on the use of nested generics. The
5324 -- proper solution requires a full renaming model.
5326 function Is_Visible_Operation (Op : Entity_Id) return Boolean;
5327 -- If the renamed entity is an implicit operator, check whether it is
5328 -- visible because its operand type is properly visible. This check
5329 -- applies to explicit renamed entities that appear in the source in a
5330 -- renaming declaration or a formal subprogram instance, but not to
5331 -- default generic actuals with a name.
5333 function Report_Overload return Entity_Id;
5334 -- List possible interpretations, and specialize message in the
5335 -- case of a generic actual.
5337 function Within (Inner, Outer : Entity_Id) return Boolean;
5338 -- Determine whether a candidate subprogram is defined within the
5339 -- enclosing instance. If yes, it has precedence over outer candidates.
5341 ------------------------
5342 -- Enclosing_Instance --
5343 ------------------------
5345 function Enclosing_Instance return Entity_Id is
5349 if not Is_Generic_Instance (Current_Scope)
5350 and then not Is_Actual
5355 S := Scope (Current_Scope);
5356 while S /= Standard_Standard loop
5357 if Is_Generic_Instance (S) then
5365 end Enclosing_Instance;
5367 --------------------------
5368 -- Is_Visible_Operation --
5369 --------------------------
5371 function Is_Visible_Operation (Op : Entity_Id) return Boolean is
5377 if Ekind (Op) /= E_Operator
5378 or else Scope (Op) /= Standard_Standard
5379 or else (In_Instance
5382 or else Present (Enclosing_Instance)))
5387 -- For a fixed point type operator, check the resulting type,
5388 -- because it may be a mixed mode integer * fixed operation.
5390 if Present (Next_Formal (First_Formal (New_S)))
5391 and then Is_Fixed_Point_Type (Etype (New_S))
5393 Typ := Etype (New_S);
5395 Typ := Etype (First_Formal (New_S));
5398 Btyp := Base_Type (Typ);
5400 if Nkind (Nam) /= N_Expanded_Name then
5401 return (In_Open_Scopes (Scope (Btyp))
5402 or else Is_Potentially_Use_Visible (Btyp)
5403 or else In_Use (Btyp)
5404 or else In_Use (Scope (Btyp)));
5407 Scop := Entity (Prefix (Nam));
5409 if Ekind (Scop) = E_Package
5410 and then Present (Renamed_Object (Scop))
5412 Scop := Renamed_Object (Scop);
5415 -- Operator is visible if prefix of expanded name denotes
5416 -- scope of type, or else type is defined in System_Aux
5417 -- and the prefix denotes System.
5419 return Scope (Btyp) = Scop
5420 or else (Scope (Btyp) = System_Aux_Id
5421 and then Scope (Scope (Btyp)) = Scop);
5424 end Is_Visible_Operation;
5430 function Within (Inner, Outer : Entity_Id) return Boolean is
5434 Sc := Scope (Inner);
5435 while Sc /= Standard_Standard loop
5446 ---------------------
5447 -- Report_Overload --
5448 ---------------------
5450 function Report_Overload return Entity_Id is
5453 Error_Msg_NE -- CODEFIX
5454 ("ambiguous actual subprogram&, " &
5455 "possible interpretations:", N, Nam);
5457 Error_Msg_N -- CODEFIX
5458 ("ambiguous subprogram, " &
5459 "possible interpretations:", N);
5462 List_Interps (Nam, N);
5464 end Report_Overload;
5466 -- Start of processing for Find_Renamed_Entity
5470 Candidate_Renaming := Empty;
5472 if not Is_Overloaded (Nam) then
5473 if Entity_Matches_Spec (Entity (Nam), New_S) then
5474 Candidate_Renaming := New_S;
5476 if Is_Visible_Operation (Entity (Nam)) then
5477 Old_S := Entity (Nam);
5481 Present (First_Formal (Entity (Nam)))
5482 and then Present (First_Formal (New_S))
5483 and then (Base_Type (Etype (First_Formal (Entity (Nam))))
5484 = Base_Type (Etype (First_Formal (New_S))))
5486 Candidate_Renaming := Entity (Nam);
5490 Get_First_Interp (Nam, Ind, It);
5491 while Present (It.Nam) loop
5492 if Entity_Matches_Spec (It.Nam, New_S)
5493 and then Is_Visible_Operation (It.Nam)
5495 if Old_S /= Any_Id then
5497 -- Note: The call to Disambiguate only happens if a
5498 -- previous interpretation was found, in which case I1
5499 -- has received a value.
5501 It1 := Disambiguate (Nam, I1, Ind, Etype (Old_S));
5503 if It1 = No_Interp then
5504 Inst := Enclosing_Instance;
5506 if Present (Inst) then
5507 if Within (It.Nam, Inst) then
5509 elsif Within (Old_S, Inst) then
5512 return Report_Overload;
5516 return Report_Overload;
5530 Present (First_Formal (It.Nam))
5531 and then Present (First_Formal (New_S))
5532 and then (Base_Type (Etype (First_Formal (It.Nam)))
5533 = Base_Type (Etype (First_Formal (New_S))))
5535 Candidate_Renaming := It.Nam;
5538 Get_Next_Interp (Ind, It);
5541 Set_Entity (Nam, Old_S);
5543 if Old_S /= Any_Id then
5544 Set_Is_Overloaded (Nam, False);
5549 end Find_Renamed_Entity;
5551 -----------------------------
5552 -- Find_Selected_Component --
5553 -----------------------------
5555 procedure Find_Selected_Component (N : Node_Id) is
5556 P : constant Node_Id := Prefix (N);
5559 -- Entity denoted by prefix
5569 if Nkind (P) = N_Error then
5573 -- Selector name cannot be a character literal or an operator symbol in
5574 -- SPARK, except for the operator symbol in a renaming.
5576 if Restriction_Check_Required (SPARK) then
5577 if Nkind (Selector_Name (N)) = N_Character_Literal then
5578 Check_SPARK_Restriction
5579 ("character literal cannot be prefixed", N);
5580 elsif Nkind (Selector_Name (N)) = N_Operator_Symbol
5581 and then Nkind (Parent (N)) /= N_Subprogram_Renaming_Declaration
5583 Check_SPARK_Restriction ("operator symbol cannot be prefixed", N);
5587 -- If the selector already has an entity, the node has been constructed
5588 -- in the course of expansion, and is known to be valid. Do not verify
5589 -- that it is defined for the type (it may be a private component used
5590 -- in the expansion of record equality).
5592 if Present (Entity (Selector_Name (N))) then
5594 or else Etype (N) = Any_Type
5597 Sel_Name : constant Node_Id := Selector_Name (N);
5598 Selector : constant Entity_Id := Entity (Sel_Name);
5602 Set_Etype (Sel_Name, Etype (Selector));
5604 if not Is_Entity_Name (P) then
5608 -- Build an actual subtype except for the first parameter
5609 -- of an init proc, where this actual subtype is by
5610 -- definition incorrect, since the object is uninitialized
5611 -- (and does not even have defined discriminants etc.)
5613 if Is_Entity_Name (P)
5614 and then Ekind (Entity (P)) = E_Function
5616 Nam := New_Copy (P);
5618 if Is_Overloaded (P) then
5619 Save_Interps (P, Nam);
5623 Make_Function_Call (Sloc (P), Name => Nam));
5625 Analyze_Selected_Component (N);
5628 elsif Ekind (Selector) = E_Component
5629 and then (not Is_Entity_Name (P)
5630 or else Chars (Entity (P)) /= Name_uInit)
5632 -- Do not build the subtype when referencing components of
5633 -- dispatch table wrappers. Required to avoid generating
5634 -- elaboration code with HI runtimes. JVM and .NET use a
5635 -- modified version of Ada.Tags which does not contain RE_
5636 -- Dispatch_Table_Wrapper and RE_No_Dispatch_Table_Wrapper.
5637 -- Avoid raising RE_Not_Available exception in those cases.
5639 if VM_Target = No_VM
5640 and then RTU_Loaded (Ada_Tags)
5642 ((RTE_Available (RE_Dispatch_Table_Wrapper)
5643 and then Scope (Selector) =
5644 RTE (RE_Dispatch_Table_Wrapper))
5646 (RTE_Available (RE_No_Dispatch_Table_Wrapper)
5647 and then Scope (Selector) =
5648 RTE (RE_No_Dispatch_Table_Wrapper)))
5654 Build_Actual_Subtype_Of_Component
5655 (Etype (Selector), N);
5662 if No (C_Etype) then
5663 C_Etype := Etype (Selector);
5665 Insert_Action (N, C_Etype);
5666 C_Etype := Defining_Identifier (C_Etype);
5669 Set_Etype (N, C_Etype);
5672 -- If this is the name of an entry or protected operation, and
5673 -- the prefix is an access type, insert an explicit dereference,
5674 -- so that entry calls are treated uniformly.
5676 if Is_Access_Type (Etype (P))
5677 and then Is_Concurrent_Type (Designated_Type (Etype (P)))
5680 New_P : constant Node_Id :=
5681 Make_Explicit_Dereference (Sloc (P),
5682 Prefix => Relocate_Node (P));
5685 Set_Etype (P, Designated_Type (Etype (Prefix (P))));
5689 -- If the selected component appears within a default expression
5690 -- and it has an actual subtype, the pre-analysis has not yet
5691 -- completed its analysis, because Insert_Actions is disabled in
5692 -- that context. Within the init proc of the enclosing type we
5693 -- must complete this analysis, if an actual subtype was created.
5695 elsif Inside_Init_Proc then
5697 Typ : constant Entity_Id := Etype (N);
5698 Decl : constant Node_Id := Declaration_Node (Typ);
5700 if Nkind (Decl) = N_Subtype_Declaration
5701 and then not Analyzed (Decl)
5702 and then Is_List_Member (Decl)
5703 and then No (Parent (Decl))
5706 Insert_Action (N, Decl);
5713 elsif Is_Entity_Name (P) then
5714 P_Name := Entity (P);
5716 -- The prefix may denote an enclosing type which is the completion
5717 -- of an incomplete type declaration.
5719 if Is_Type (P_Name) then
5720 Set_Entity (P, Get_Full_View (P_Name));
5721 Set_Etype (P, Entity (P));
5722 P_Name := Entity (P);
5725 P_Type := Base_Type (Etype (P));
5727 if Debug_Flag_E then
5728 Write_Str ("Found prefix type to be ");
5729 Write_Entity_Info (P_Type, " "); Write_Eol;
5732 -- First check for components of a record object (not the
5733 -- result of a call, which is handled below).
5735 if Is_Appropriate_For_Record (P_Type)
5736 and then not Is_Overloadable (P_Name)
5737 and then not Is_Type (P_Name)
5739 -- Selected component of record. Type checking will validate
5740 -- name of selector.
5741 -- ??? could we rewrite an implicit dereference into an explicit
5744 Analyze_Selected_Component (N);
5746 -- Reference to type name in predicate/invariant expression
5748 elsif Is_Appropriate_For_Entry_Prefix (P_Type)
5749 and then not In_Open_Scopes (P_Name)
5750 and then (not Is_Concurrent_Type (Etype (P_Name))
5751 or else not In_Open_Scopes (Etype (P_Name)))
5753 -- Call to protected operation or entry. Type checking is
5754 -- needed on the prefix.
5756 Analyze_Selected_Component (N);
5758 elsif (In_Open_Scopes (P_Name)
5759 and then Ekind (P_Name) /= E_Void
5760 and then not Is_Overloadable (P_Name))
5761 or else (Is_Concurrent_Type (Etype (P_Name))
5762 and then In_Open_Scopes (Etype (P_Name)))
5764 -- Prefix denotes an enclosing loop, block, or task, i.e. an
5765 -- enclosing construct that is not a subprogram or accept.
5767 Find_Expanded_Name (N);
5769 elsif Ekind (P_Name) = E_Package then
5770 Find_Expanded_Name (N);
5772 elsif Is_Overloadable (P_Name) then
5774 -- The subprogram may be a renaming (of an enclosing scope) as
5775 -- in the case of the name of the generic within an instantiation.
5777 if Ekind_In (P_Name, E_Procedure, E_Function)
5778 and then Present (Alias (P_Name))
5779 and then Is_Generic_Instance (Alias (P_Name))
5781 P_Name := Alias (P_Name);
5784 if Is_Overloaded (P) then
5786 -- The prefix must resolve to a unique enclosing construct
5789 Found : Boolean := False;
5794 Get_First_Interp (P, Ind, It);
5795 while Present (It.Nam) loop
5796 if In_Open_Scopes (It.Nam) then
5799 "prefix must be unique enclosing scope", N);
5800 Set_Entity (N, Any_Id);
5801 Set_Etype (N, Any_Type);
5810 Get_Next_Interp (Ind, It);
5815 if In_Open_Scopes (P_Name) then
5816 Set_Entity (P, P_Name);
5817 Set_Is_Overloaded (P, False);
5818 Find_Expanded_Name (N);
5821 -- If no interpretation as an expanded name is possible, it
5822 -- must be a selected component of a record returned by a
5823 -- function call. Reformat prefix as a function call, the rest
5824 -- is done by type resolution. If the prefix is procedure or
5825 -- entry, as is P.X; this is an error.
5827 if Ekind (P_Name) /= E_Function
5828 and then (not Is_Overloaded (P)
5830 Nkind (Parent (N)) = N_Procedure_Call_Statement)
5832 -- Prefix may mention a package that is hidden by a local
5833 -- declaration: let the user know. Scan the full homonym
5834 -- chain, the candidate package may be anywhere on it.
5836 if Present (Homonym (Current_Entity (P_Name))) then
5838 P_Name := Current_Entity (P_Name);
5840 while Present (P_Name) loop
5841 exit when Ekind (P_Name) = E_Package;
5842 P_Name := Homonym (P_Name);
5845 if Present (P_Name) then
5846 Error_Msg_Sloc := Sloc (Entity (Prefix (N)));
5849 ("package& is hidden by declaration#",
5852 Set_Entity (Prefix (N), P_Name);
5853 Find_Expanded_Name (N);
5856 P_Name := Entity (Prefix (N));
5861 ("invalid prefix in selected component&", N, P_Name);
5862 Change_Selected_Component_To_Expanded_Name (N);
5863 Set_Entity (N, Any_Id);
5864 Set_Etype (N, Any_Type);
5867 Nam := New_Copy (P);
5868 Save_Interps (P, Nam);
5870 Make_Function_Call (Sloc (P), Name => Nam));
5872 Analyze_Selected_Component (N);
5876 -- Remaining cases generate various error messages
5879 -- Format node as expanded name, to avoid cascaded errors
5881 Change_Selected_Component_To_Expanded_Name (N);
5882 Set_Entity (N, Any_Id);
5883 Set_Etype (N, Any_Type);
5885 -- Issue error message, but avoid this if error issued already.
5886 -- Use identifier of prefix if one is available.
5888 if P_Name = Any_Id then
5891 elsif Ekind (P_Name) = E_Void then
5892 Premature_Usage (P);
5894 elsif Nkind (P) /= N_Attribute_Reference then
5896 "invalid prefix in selected component&", P);
5898 if Is_Access_Type (P_Type)
5899 and then Ekind (Designated_Type (P_Type)) = E_Incomplete_Type
5902 ("\dereference must not be of an incomplete type " &
5908 "invalid prefix in selected component", P);
5912 -- Selector name is restricted in SPARK
5914 if Nkind (N) = N_Expanded_Name
5915 and then Restriction_Check_Required (SPARK)
5917 if Is_Subprogram (P_Name) then
5918 Check_SPARK_Restriction
5919 ("prefix of expanded name cannot be a subprogram", P);
5920 elsif Ekind (P_Name) = E_Loop then
5921 Check_SPARK_Restriction
5922 ("prefix of expanded name cannot be a loop statement", P);
5927 -- If prefix is not the name of an entity, it must be an expression,
5928 -- whose type is appropriate for a record. This is determined by
5931 Analyze_Selected_Component (N);
5933 end Find_Selected_Component;
5939 procedure Find_Type (N : Node_Id) is
5949 elsif Nkind (N) = N_Attribute_Reference then
5951 -- Class attribute. This is not valid in Ada 83 mode, but we do not
5952 -- need to enforce that at this point, since the declaration of the
5953 -- tagged type in the prefix would have been flagged already.
5955 if Attribute_Name (N) = Name_Class then
5956 Check_Restriction (No_Dispatch, N);
5957 Find_Type (Prefix (N));
5959 -- Propagate error from bad prefix
5961 if Etype (Prefix (N)) = Any_Type then
5962 Set_Entity (N, Any_Type);
5963 Set_Etype (N, Any_Type);
5967 T := Base_Type (Entity (Prefix (N)));
5969 -- Case where type is not known to be tagged. Its appearance in
5970 -- the prefix of the 'Class attribute indicates that the full view
5973 if not Is_Tagged_Type (T) then
5974 if Ekind (T) = E_Incomplete_Type then
5976 -- It is legal to denote the class type of an incomplete
5977 -- type. The full type will have to be tagged, of course.
5978 -- In Ada 2005 this usage is declared obsolescent, so we
5979 -- warn accordingly. This usage is only legal if the type
5980 -- is completed in the current scope, and not for a limited
5983 if not Is_Tagged_Type (T)
5984 and then Ada_Version >= Ada_2005
5986 if From_With_Type (T) then
5988 ("prefix of Class attribute must be tagged", N);
5989 Set_Etype (N, Any_Type);
5990 Set_Entity (N, Any_Type);
5993 -- ??? This test is temporarily disabled (always False)
5994 -- because it causes an unwanted warning on GNAT sources
5995 -- (built with -gnatg, which includes Warn_On_Obsolescent_
5996 -- Feature). Once this issue is cleared in the sources, it
5999 elsif Warn_On_Obsolescent_Feature
6003 ("applying 'Class to an untagged incomplete type"
6004 & " is an obsolescent feature (RM J.11)", N);
6008 Set_Is_Tagged_Type (T);
6009 Set_Direct_Primitive_Operations (T, New_Elmt_List);
6010 Make_Class_Wide_Type (T);
6011 Set_Entity (N, Class_Wide_Type (T));
6012 Set_Etype (N, Class_Wide_Type (T));
6014 elsif Ekind (T) = E_Private_Type
6015 and then not Is_Generic_Type (T)
6016 and then In_Private_Part (Scope (T))
6018 -- The Class attribute can be applied to an untagged private
6019 -- type fulfilled by a tagged type prior to the full type
6020 -- declaration (but only within the parent package's private
6021 -- part). Create the class-wide type now and check that the
6022 -- full type is tagged later during its analysis. Note that
6023 -- we do not mark the private type as tagged, unlike the
6024 -- case of incomplete types, because the type must still
6025 -- appear untagged to outside units.
6027 if No (Class_Wide_Type (T)) then
6028 Make_Class_Wide_Type (T);
6031 Set_Entity (N, Class_Wide_Type (T));
6032 Set_Etype (N, Class_Wide_Type (T));
6035 -- Should we introduce a type Any_Tagged and use Wrong_Type
6036 -- here, it would be a bit more consistent???
6039 ("tagged type required, found}",
6040 Prefix (N), First_Subtype (T));
6041 Set_Entity (N, Any_Type);
6045 -- Case of tagged type
6048 if Is_Concurrent_Type (T) then
6049 if No (Corresponding_Record_Type (Entity (Prefix (N)))) then
6051 -- Previous error. Use current type, which at least
6052 -- provides some operations.
6054 C := Entity (Prefix (N));
6057 C := Class_Wide_Type
6058 (Corresponding_Record_Type (Entity (Prefix (N))));
6062 C := Class_Wide_Type (Entity (Prefix (N)));
6065 Set_Entity_With_Style_Check (N, C);
6066 Generate_Reference (C, N);
6070 -- Base attribute, not allowed in Ada 83
6072 elsif Attribute_Name (N) = Name_Base then
6073 Error_Msg_Name_1 := Name_Base;
6074 Check_SPARK_Restriction
6075 ("attribute% is only allowed as prefix of another attribute", N);
6077 if Ada_Version = Ada_83 and then Comes_From_Source (N) then
6079 ("(Ada 83) Base attribute not allowed in subtype mark", N);
6082 Find_Type (Prefix (N));
6083 Typ := Entity (Prefix (N));
6085 if Ada_Version >= Ada_95
6086 and then not Is_Scalar_Type (Typ)
6087 and then not Is_Generic_Type (Typ)
6090 ("prefix of Base attribute must be scalar type",
6093 elsif Warn_On_Redundant_Constructs
6094 and then Base_Type (Typ) = Typ
6096 Error_Msg_NE -- CODEFIX
6097 ("?redundant attribute, & is its own base type", N, Typ);
6100 T := Base_Type (Typ);
6102 -- Rewrite attribute reference with type itself (see similar
6103 -- processing in Analyze_Attribute, case Base). Preserve prefix
6104 -- if present, for other legality checks.
6106 if Nkind (Prefix (N)) = N_Expanded_Name then
6108 Make_Expanded_Name (Sloc (N),
6110 Prefix => New_Copy (Prefix (Prefix (N))),
6111 Selector_Name => New_Reference_To (T, Sloc (N))));
6114 Rewrite (N, New_Reference_To (T, Sloc (N)));
6121 elsif Attribute_Name (N) = Name_Stub_Type then
6123 -- This is handled in Analyze_Attribute
6127 -- All other attributes are invalid in a subtype mark
6130 Error_Msg_N ("invalid attribute in subtype mark", N);
6136 if Is_Entity_Name (N) then
6137 T_Name := Entity (N);
6139 Error_Msg_N ("subtype mark required in this context", N);
6140 Set_Etype (N, Any_Type);
6144 if T_Name = Any_Id or else Etype (N) = Any_Type then
6146 -- Undefined id. Make it into a valid type
6148 Set_Entity (N, Any_Type);
6150 elsif not Is_Type (T_Name)
6151 and then T_Name /= Standard_Void_Type
6153 Error_Msg_Sloc := Sloc (T_Name);
6154 Error_Msg_N ("subtype mark required in this context", N);
6155 Error_Msg_NE ("\\found & declared#", N, T_Name);
6156 Set_Entity (N, Any_Type);
6159 -- If the type is an incomplete type created to handle
6160 -- anonymous access components of a record type, then the
6161 -- incomplete type is the visible entity and subsequent
6162 -- references will point to it. Mark the original full
6163 -- type as referenced, to prevent spurious warnings.
6165 if Is_Incomplete_Type (T_Name)
6166 and then Present (Full_View (T_Name))
6167 and then not Comes_From_Source (T_Name)
6169 Set_Referenced (Full_View (T_Name));
6172 T_Name := Get_Full_View (T_Name);
6174 -- Ada 2005 (AI-251, AI-50217): Handle interfaces visible through
6175 -- limited-with clauses
6177 if From_With_Type (T_Name)
6178 and then Ekind (T_Name) in Incomplete_Kind
6179 and then Present (Non_Limited_View (T_Name))
6180 and then Is_Interface (Non_Limited_View (T_Name))
6182 T_Name := Non_Limited_View (T_Name);
6185 if In_Open_Scopes (T_Name) then
6186 if Ekind (Base_Type (T_Name)) = E_Task_Type then
6188 -- In Ada 2005, a task name can be used in an access
6189 -- definition within its own body. It cannot be used
6190 -- in the discriminant part of the task declaration,
6191 -- nor anywhere else in the declaration because entries
6192 -- cannot have access parameters.
6194 if Ada_Version >= Ada_2005
6195 and then Nkind (Parent (N)) = N_Access_Definition
6197 Set_Entity (N, T_Name);
6198 Set_Etype (N, T_Name);
6200 if Has_Completion (T_Name) then
6205 ("task type cannot be used as type mark " &
6206 "within its own declaration", N);
6211 ("task type cannot be used as type mark " &
6212 "within its own spec or body", N);
6215 elsif Ekind (Base_Type (T_Name)) = E_Protected_Type then
6217 -- In Ada 2005, a protected name can be used in an access
6218 -- definition within its own body.
6220 if Ada_Version >= Ada_2005
6221 and then Nkind (Parent (N)) = N_Access_Definition
6223 Set_Entity (N, T_Name);
6224 Set_Etype (N, T_Name);
6229 ("protected type cannot be used as type mark " &
6230 "within its own spec or body", N);
6234 Error_Msg_N ("type declaration cannot refer to itself", N);
6237 Set_Etype (N, Any_Type);
6238 Set_Entity (N, Any_Type);
6239 Set_Error_Posted (T_Name);
6243 Set_Entity (N, T_Name);
6244 Set_Etype (N, T_Name);
6248 if Present (Etype (N)) and then Comes_From_Source (N) then
6249 if Is_Fixed_Point_Type (Etype (N)) then
6250 Check_Restriction (No_Fixed_Point, N);
6251 elsif Is_Floating_Point_Type (Etype (N)) then
6252 Check_Restriction (No_Floating_Point, N);
6257 ------------------------------------
6258 -- Has_Implicit_Character_Literal --
6259 ------------------------------------
6261 function Has_Implicit_Character_Literal (N : Node_Id) return Boolean is
6263 Found : Boolean := False;
6264 P : constant Entity_Id := Entity (Prefix (N));
6265 Priv_Id : Entity_Id := Empty;
6268 if Ekind (P) = E_Package
6269 and then not In_Open_Scopes (P)
6271 Priv_Id := First_Private_Entity (P);
6274 if P = Standard_Standard then
6275 Change_Selected_Component_To_Expanded_Name (N);
6276 Rewrite (N, Selector_Name (N));
6278 Set_Etype (Original_Node (N), Standard_Character);
6282 Id := First_Entity (P);
6284 and then Id /= Priv_Id
6286 if Is_Standard_Character_Type (Id) and then Is_Base_Type (Id) then
6288 -- We replace the node with the literal itself, resolve as a
6289 -- character, and set the type correctly.
6292 Change_Selected_Component_To_Expanded_Name (N);
6293 Rewrite (N, Selector_Name (N));
6296 Set_Etype (Original_Node (N), Id);
6300 -- More than one type derived from Character in given scope.
6301 -- Collect all possible interpretations.
6303 Add_One_Interp (N, Id, Id);
6311 end Has_Implicit_Character_Literal;
6313 ----------------------
6314 -- Has_Private_With --
6315 ----------------------
6317 function Has_Private_With (E : Entity_Id) return Boolean is
6318 Comp_Unit : constant Node_Id := Cunit (Current_Sem_Unit);
6322 Item := First (Context_Items (Comp_Unit));
6323 while Present (Item) loop
6324 if Nkind (Item) = N_With_Clause
6325 and then Private_Present (Item)
6326 and then Entity (Name (Item)) = E
6335 end Has_Private_With;
6337 ---------------------------
6338 -- Has_Implicit_Operator --
6339 ---------------------------
6341 function Has_Implicit_Operator (N : Node_Id) return Boolean is
6342 Op_Id : constant Name_Id := Chars (Selector_Name (N));
6343 P : constant Entity_Id := Entity (Prefix (N));
6345 Priv_Id : Entity_Id := Empty;
6347 procedure Add_Implicit_Operator
6349 Op_Type : Entity_Id := Empty);
6350 -- Add implicit interpretation to node N, using the type for which a
6351 -- predefined operator exists. If the operator yields a boolean type,
6352 -- the Operand_Type is implicitly referenced by the operator, and a
6353 -- reference to it must be generated.
6355 ---------------------------
6356 -- Add_Implicit_Operator --
6357 ---------------------------
6359 procedure Add_Implicit_Operator
6361 Op_Type : Entity_Id := Empty)
6363 Predef_Op : Entity_Id;
6366 Predef_Op := Current_Entity (Selector_Name (N));
6368 while Present (Predef_Op)
6369 and then Scope (Predef_Op) /= Standard_Standard
6371 Predef_Op := Homonym (Predef_Op);
6374 if Nkind (N) = N_Selected_Component then
6375 Change_Selected_Component_To_Expanded_Name (N);
6378 -- If the context is an unanalyzed function call, determine whether
6379 -- a binary or unary interpretation is required.
6381 if Nkind (Parent (N)) = N_Indexed_Component then
6383 Is_Binary_Call : constant Boolean :=
6385 (Next (First (Expressions (Parent (N)))));
6386 Is_Binary_Op : constant Boolean :=
6388 (Predef_Op) /= Last_Entity (Predef_Op);
6389 Predef_Op2 : constant Entity_Id := Homonym (Predef_Op);
6392 if Is_Binary_Call then
6393 if Is_Binary_Op then
6394 Add_One_Interp (N, Predef_Op, T);
6396 Add_One_Interp (N, Predef_Op2, T);
6400 if not Is_Binary_Op then
6401 Add_One_Interp (N, Predef_Op, T);
6403 Add_One_Interp (N, Predef_Op2, T);
6409 Add_One_Interp (N, Predef_Op, T);
6411 -- For operators with unary and binary interpretations, if
6412 -- context is not a call, add both
6414 if Present (Homonym (Predef_Op)) then
6415 Add_One_Interp (N, Homonym (Predef_Op), T);
6419 -- The node is a reference to a predefined operator, and
6420 -- an implicit reference to the type of its operands.
6422 if Present (Op_Type) then
6423 Generate_Operator_Reference (N, Op_Type);
6425 Generate_Operator_Reference (N, T);
6427 end Add_Implicit_Operator;
6429 -- Start of processing for Has_Implicit_Operator
6432 if Ekind (P) = E_Package
6433 and then not In_Open_Scopes (P)
6435 Priv_Id := First_Private_Entity (P);
6438 Id := First_Entity (P);
6442 -- Boolean operators: an implicit declaration exists if the scope
6443 -- contains a declaration for a derived Boolean type, or for an
6444 -- array of Boolean type.
6446 when Name_Op_And | Name_Op_Not | Name_Op_Or | Name_Op_Xor =>
6447 while Id /= Priv_Id loop
6448 if Valid_Boolean_Arg (Id) and then Is_Base_Type (Id) then
6449 Add_Implicit_Operator (Id);
6456 -- Equality: look for any non-limited type (result is Boolean)
6458 when Name_Op_Eq | Name_Op_Ne =>
6459 while Id /= Priv_Id loop
6461 and then not Is_Limited_Type (Id)
6462 and then Is_Base_Type (Id)
6464 Add_Implicit_Operator (Standard_Boolean, Id);
6471 -- Comparison operators: scalar type, or array of scalar
6473 when Name_Op_Lt | Name_Op_Le | Name_Op_Gt | Name_Op_Ge =>
6474 while Id /= Priv_Id loop
6475 if (Is_Scalar_Type (Id)
6476 or else (Is_Array_Type (Id)
6477 and then Is_Scalar_Type (Component_Type (Id))))
6478 and then Is_Base_Type (Id)
6480 Add_Implicit_Operator (Standard_Boolean, Id);
6487 -- Arithmetic operators: any numeric type
6497 while Id /= Priv_Id loop
6498 if Is_Numeric_Type (Id) and then Is_Base_Type (Id) then
6499 Add_Implicit_Operator (Id);
6506 -- Concatenation: any one-dimensional array type
6508 when Name_Op_Concat =>
6509 while Id /= Priv_Id loop
6510 if Is_Array_Type (Id)
6511 and then Number_Dimensions (Id) = 1
6512 and then Is_Base_Type (Id)
6514 Add_Implicit_Operator (Id);
6521 -- What is the others condition here? Should we be using a
6522 -- subtype of Name_Id that would restrict to operators ???
6524 when others => null;
6527 -- If we fall through, then we do not have an implicit operator
6531 end Has_Implicit_Operator;
6533 -----------------------------------
6534 -- Has_Loop_In_Inner_Open_Scopes --
6535 -----------------------------------
6537 function Has_Loop_In_Inner_Open_Scopes (S : Entity_Id) return Boolean is
6539 -- Several scope stacks are maintained by Scope_Stack. The base of the
6540 -- currently active scope stack is denoted by the Is_Active_Stack_Base
6541 -- flag in the scope stack entry. Note that the scope stacks used to
6542 -- simply be delimited implicitly by the presence of Standard_Standard
6543 -- at their base, but there now are cases where this is not sufficient
6544 -- because Standard_Standard actually may appear in the middle of the
6545 -- active set of scopes.
6547 for J in reverse 0 .. Scope_Stack.Last loop
6549 -- S was reached without seing a loop scope first
6551 if Scope_Stack.Table (J).Entity = S then
6554 -- S was not yet reached, so it contains at least one inner loop
6556 elsif Ekind (Scope_Stack.Table (J).Entity) = E_Loop then
6560 -- Check Is_Active_Stack_Base to tell us when to stop, as there are
6561 -- cases where Standard_Standard appears in the middle of the active
6562 -- set of scopes. This affects the declaration and overriding of
6563 -- private inherited operations in instantiations of generic child
6566 pragma Assert (not Scope_Stack.Table (J).Is_Active_Stack_Base);
6569 raise Program_Error; -- unreachable
6570 end Has_Loop_In_Inner_Open_Scopes;
6572 --------------------
6573 -- In_Open_Scopes --
6574 --------------------
6576 function In_Open_Scopes (S : Entity_Id) return Boolean is
6578 -- Several scope stacks are maintained by Scope_Stack. The base of the
6579 -- currently active scope stack is denoted by the Is_Active_Stack_Base
6580 -- flag in the scope stack entry. Note that the scope stacks used to
6581 -- simply be delimited implicitly by the presence of Standard_Standard
6582 -- at their base, but there now are cases where this is not sufficient
6583 -- because Standard_Standard actually may appear in the middle of the
6584 -- active set of scopes.
6586 for J in reverse 0 .. Scope_Stack.Last loop
6587 if Scope_Stack.Table (J).Entity = S then
6591 -- Check Is_Active_Stack_Base to tell us when to stop, as there are
6592 -- cases where Standard_Standard appears in the middle of the active
6593 -- set of scopes. This affects the declaration and overriding of
6594 -- private inherited operations in instantiations of generic child
6597 exit when Scope_Stack.Table (J).Is_Active_Stack_Base;
6603 -----------------------------
6604 -- Inherit_Renamed_Profile --
6605 -----------------------------
6607 procedure Inherit_Renamed_Profile (New_S : Entity_Id; Old_S : Entity_Id) is
6614 if Ekind (Old_S) = E_Operator then
6615 New_F := First_Formal (New_S);
6617 while Present (New_F) loop
6618 Set_Etype (New_F, Base_Type (Etype (New_F)));
6619 Next_Formal (New_F);
6622 Set_Etype (New_S, Base_Type (Etype (New_S)));
6625 New_F := First_Formal (New_S);
6626 Old_F := First_Formal (Old_S);
6628 while Present (New_F) loop
6629 New_T := Etype (New_F);
6630 Old_T := Etype (Old_F);
6632 -- If the new type is a renaming of the old one, as is the
6633 -- case for actuals in instances, retain its name, to simplify
6634 -- later disambiguation.
6636 if Nkind (Parent (New_T)) = N_Subtype_Declaration
6637 and then Is_Entity_Name (Subtype_Indication (Parent (New_T)))
6638 and then Entity (Subtype_Indication (Parent (New_T))) = Old_T
6642 Set_Etype (New_F, Old_T);
6645 Next_Formal (New_F);
6646 Next_Formal (Old_F);
6649 if Ekind_In (Old_S, E_Function, E_Enumeration_Literal) then
6650 Set_Etype (New_S, Etype (Old_S));
6653 end Inherit_Renamed_Profile;
6659 procedure Initialize is
6664 -------------------------
6665 -- Install_Use_Clauses --
6666 -------------------------
6668 procedure Install_Use_Clauses
6670 Force_Installation : Boolean := False)
6678 while Present (U) loop
6680 -- Case of USE package
6682 if Nkind (U) = N_Use_Package_Clause then
6683 P := First (Names (U));
6684 while Present (P) loop
6687 if Ekind (Id) = E_Package then
6689 Note_Redundant_Use (P);
6691 elsif Present (Renamed_Object (Id))
6692 and then In_Use (Renamed_Object (Id))
6694 Note_Redundant_Use (P);
6696 elsif Force_Installation or else Applicable_Use (P) then
6697 Use_One_Package (Id, U);
6708 P := First (Subtype_Marks (U));
6709 while Present (P) loop
6710 if not Is_Entity_Name (P)
6711 or else No (Entity (P))
6715 elsif Entity (P) /= Any_Type then
6723 Next_Use_Clause (U);
6725 end Install_Use_Clauses;
6727 -------------------------------------
6728 -- Is_Appropriate_For_Entry_Prefix --
6729 -------------------------------------
6731 function Is_Appropriate_For_Entry_Prefix (T : Entity_Id) return Boolean is
6732 P_Type : Entity_Id := T;
6735 if Is_Access_Type (P_Type) then
6736 P_Type := Designated_Type (P_Type);
6739 return Is_Task_Type (P_Type) or else Is_Protected_Type (P_Type);
6740 end Is_Appropriate_For_Entry_Prefix;
6742 -------------------------------
6743 -- Is_Appropriate_For_Record --
6744 -------------------------------
6746 function Is_Appropriate_For_Record (T : Entity_Id) return Boolean is
6748 function Has_Components (T1 : Entity_Id) return Boolean;
6749 -- Determine if given type has components (i.e. is either a record
6750 -- type or a type that has discriminants).
6752 --------------------
6753 -- Has_Components --
6754 --------------------
6756 function Has_Components (T1 : Entity_Id) return Boolean is
6758 return Is_Record_Type (T1)
6759 or else (Is_Private_Type (T1) and then Has_Discriminants (T1))
6760 or else (Is_Task_Type (T1) and then Has_Discriminants (T1))
6761 or else (Is_Incomplete_Type (T1)
6762 and then From_With_Type (T1)
6763 and then Present (Non_Limited_View (T1))
6764 and then Is_Record_Type
6765 (Get_Full_View (Non_Limited_View (T1))));
6768 -- Start of processing for Is_Appropriate_For_Record
6773 and then (Has_Components (T)
6774 or else (Is_Access_Type (T)
6775 and then Has_Components (Designated_Type (T))));
6776 end Is_Appropriate_For_Record;
6778 ------------------------
6779 -- Note_Redundant_Use --
6780 ------------------------
6782 procedure Note_Redundant_Use (Clause : Node_Id) is
6783 Pack_Name : constant Entity_Id := Entity (Clause);
6784 Cur_Use : constant Node_Id := Current_Use_Clause (Pack_Name);
6785 Decl : constant Node_Id := Parent (Clause);
6787 Prev_Use : Node_Id := Empty;
6788 Redundant : Node_Id := Empty;
6789 -- The Use_Clause which is actually redundant. In the simplest case it
6790 -- is Pack itself, but when we compile a body we install its context
6791 -- before that of its spec, in which case it is the use_clause in the
6792 -- spec that will appear to be redundant, and we want the warning to be
6793 -- placed on the body. Similar complications appear when the redundancy
6794 -- is between a child unit and one of its ancestors.
6797 Set_Redundant_Use (Clause, True);
6799 if not Comes_From_Source (Clause)
6801 or else not Warn_On_Redundant_Constructs
6806 if not Is_Compilation_Unit (Current_Scope) then
6808 -- If the use_clause is in an inner scope, it is made redundant by
6809 -- some clause in the current context, with one exception: If we're
6810 -- compiling a nested package body, and the use_clause comes from the
6811 -- corresponding spec, the clause is not necessarily fully redundant,
6812 -- so we should not warn. If a warning was warranted, it would have
6813 -- been given when the spec was processed.
6815 if Nkind (Parent (Decl)) = N_Package_Specification then
6817 Package_Spec_Entity : constant Entity_Id :=
6818 Defining_Unit_Name (Parent (Decl));
6820 if In_Package_Body (Package_Spec_Entity) then
6826 Redundant := Clause;
6827 Prev_Use := Cur_Use;
6829 elsif Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Body then
6831 Cur_Unit : constant Unit_Number_Type := Get_Source_Unit (Cur_Use);
6832 New_Unit : constant Unit_Number_Type := Get_Source_Unit (Clause);
6836 if Cur_Unit = New_Unit then
6838 -- Redundant clause in same body
6840 Redundant := Clause;
6841 Prev_Use := Cur_Use;
6843 elsif Cur_Unit = Current_Sem_Unit then
6845 -- If the new clause is not in the current unit it has been
6846 -- analyzed first, and it makes the other one redundant.
6847 -- However, if the new clause appears in a subunit, Cur_Unit
6848 -- is still the parent, and in that case the redundant one
6849 -- is the one appearing in the subunit.
6851 if Nkind (Unit (Cunit (New_Unit))) = N_Subunit then
6852 Redundant := Clause;
6853 Prev_Use := Cur_Use;
6855 -- Most common case: redundant clause in body,
6856 -- original clause in spec. Current scope is spec entity.
6861 Unit (Library_Unit (Cunit (Current_Sem_Unit))))
6863 Redundant := Cur_Use;
6867 -- The new clause may appear in an unrelated unit, when
6868 -- the parents of a generic are being installed prior to
6869 -- instantiation. In this case there must be no warning.
6870 -- We detect this case by checking whether the current top
6871 -- of the stack is related to the current compilation.
6873 Scop := Current_Scope;
6874 while Present (Scop)
6875 and then Scop /= Standard_Standard
6877 if Is_Compilation_Unit (Scop)
6878 and then not Is_Child_Unit (Scop)
6882 elsif Scop = Cunit_Entity (Current_Sem_Unit) then
6886 Scop := Scope (Scop);
6889 Redundant := Cur_Use;
6893 elsif New_Unit = Current_Sem_Unit then
6894 Redundant := Clause;
6895 Prev_Use := Cur_Use;
6898 -- Neither is the current unit, so they appear in parent or
6899 -- sibling units. Warning will be emitted elsewhere.
6905 elsif Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Declaration
6906 and then Present (Parent_Spec (Unit (Cunit (Current_Sem_Unit))))
6908 -- Use_clause is in child unit of current unit, and the child unit
6909 -- appears in the context of the body of the parent, so it has been
6910 -- installed first, even though it is the redundant one. Depending on
6911 -- their placement in the context, the visible or the private parts
6912 -- of the two units, either might appear as redundant, but the
6913 -- message has to be on the current unit.
6915 if Get_Source_Unit (Cur_Use) = Current_Sem_Unit then
6916 Redundant := Cur_Use;
6919 Redundant := Clause;
6920 Prev_Use := Cur_Use;
6923 -- If the new use clause appears in the private part of a parent unit
6924 -- it may appear to be redundant w.r.t. a use clause in a child unit,
6925 -- but the previous use clause was needed in the visible part of the
6926 -- child, and no warning should be emitted.
6928 if Nkind (Parent (Decl)) = N_Package_Specification
6930 List_Containing (Decl) = Private_Declarations (Parent (Decl))
6933 Par : constant Entity_Id := Defining_Entity (Parent (Decl));
6934 Spec : constant Node_Id :=
6935 Specification (Unit (Cunit (Current_Sem_Unit)));
6938 if Is_Compilation_Unit (Par)
6939 and then Par /= Cunit_Entity (Current_Sem_Unit)
6940 and then Parent (Cur_Use) = Spec
6942 List_Containing (Cur_Use) = Visible_Declarations (Spec)
6949 -- Finally, if the current use clause is in the context then
6950 -- the clause is redundant when it is nested within the unit.
6952 elsif Nkind (Parent (Cur_Use)) = N_Compilation_Unit
6953 and then Nkind (Parent (Parent (Clause))) /= N_Compilation_Unit
6954 and then Get_Source_Unit (Cur_Use) = Get_Source_Unit (Clause)
6956 Redundant := Clause;
6957 Prev_Use := Cur_Use;
6963 if Present (Redundant) then
6964 Error_Msg_Sloc := Sloc (Prev_Use);
6965 Error_Msg_NE -- CODEFIX
6966 ("& is already use-visible through previous use clause #?",
6967 Redundant, Pack_Name);
6969 end Note_Redundant_Use;
6975 procedure Pop_Scope is
6976 SST : Scope_Stack_Entry renames Scope_Stack.Table (Scope_Stack.Last);
6977 S : constant Entity_Id := SST.Entity;
6980 if Debug_Flag_E then
6984 -- Set Default_Storage_Pool field of the library unit if necessary
6986 if Ekind_In (S, E_Package, E_Generic_Package)
6988 Nkind (Parent (Unit_Declaration_Node (S))) = N_Compilation_Unit
6991 Aux : constant Node_Id :=
6992 Aux_Decls_Node (Parent (Unit_Declaration_Node (S)));
6994 if No (Default_Storage_Pool (Aux)) then
6995 Set_Default_Storage_Pool (Aux, Default_Pool);
7000 Scope_Suppress := SST.Save_Scope_Suppress;
7001 Local_Suppress_Stack_Top := SST.Save_Local_Suppress_Stack_Top;
7002 Check_Policy_List := SST.Save_Check_Policy_List;
7003 Default_Pool := SST.Save_Default_Storage_Pool;
7005 if Debug_Flag_W then
7006 Write_Str ("<-- exiting scope: ");
7007 Write_Name (Chars (Current_Scope));
7008 Write_Str (", Depth=");
7009 Write_Int (Int (Scope_Stack.Last));
7013 End_Use_Clauses (SST.First_Use_Clause);
7015 -- If the actions to be wrapped are still there they will get lost
7016 -- causing incomplete code to be generated. It is better to abort in
7017 -- this case (and we do the abort even with assertions off since the
7018 -- penalty is incorrect code generation)
7020 if SST.Actions_To_Be_Wrapped_Before /= No_List
7022 SST.Actions_To_Be_Wrapped_After /= No_List
7024 raise Program_Error;
7027 -- Free last subprogram name if allocated, and pop scope
7029 Free (SST.Last_Subprogram_Name);
7030 Scope_Stack.Decrement_Last;
7037 procedure Push_Scope (S : Entity_Id) is
7038 E : constant Entity_Id := Scope (S);
7041 if Ekind (S) = E_Void then
7044 -- Set scope depth if not a non-concurrent type, and we have not yet set
7045 -- the scope depth. This means that we have the first occurrence of the
7046 -- scope, and this is where the depth is set.
7048 elsif (not Is_Type (S) or else Is_Concurrent_Type (S))
7049 and then not Scope_Depth_Set (S)
7051 if S = Standard_Standard then
7052 Set_Scope_Depth_Value (S, Uint_0);
7054 elsif Is_Child_Unit (S) then
7055 Set_Scope_Depth_Value (S, Uint_1);
7057 elsif not Is_Record_Type (Current_Scope) then
7058 if Ekind (S) = E_Loop then
7059 Set_Scope_Depth_Value (S, Scope_Depth (Current_Scope));
7061 Set_Scope_Depth_Value (S, Scope_Depth (Current_Scope) + 1);
7066 Scope_Stack.Increment_Last;
7069 SST : Scope_Stack_Entry renames Scope_Stack.Table (Scope_Stack.Last);
7073 SST.Save_Scope_Suppress := Scope_Suppress;
7074 SST.Save_Local_Suppress_Stack_Top := Local_Suppress_Stack_Top;
7075 SST.Save_Check_Policy_List := Check_Policy_List;
7076 SST.Save_Default_Storage_Pool := Default_Pool;
7078 if Scope_Stack.Last > Scope_Stack.First then
7079 SST.Component_Alignment_Default := Scope_Stack.Table
7080 (Scope_Stack.Last - 1).
7081 Component_Alignment_Default;
7084 SST.Last_Subprogram_Name := null;
7085 SST.Is_Transient := False;
7086 SST.Node_To_Be_Wrapped := Empty;
7087 SST.Pending_Freeze_Actions := No_List;
7088 SST.Actions_To_Be_Wrapped_Before := No_List;
7089 SST.Actions_To_Be_Wrapped_After := No_List;
7090 SST.First_Use_Clause := Empty;
7091 SST.Is_Active_Stack_Base := False;
7092 SST.Previous_Visibility := False;
7095 if Debug_Flag_W then
7096 Write_Str ("--> new scope: ");
7097 Write_Name (Chars (Current_Scope));
7098 Write_Str (", Id=");
7099 Write_Int (Int (Current_Scope));
7100 Write_Str (", Depth=");
7101 Write_Int (Int (Scope_Stack.Last));
7105 -- Deal with copying flags from the previous scope to this one. This is
7106 -- not necessary if either scope is standard, or if the new scope is a
7109 if S /= Standard_Standard
7110 and then Scope (S) /= Standard_Standard
7111 and then not Is_Child_Unit (S)
7113 if Nkind (E) not in N_Entity then
7117 -- Copy categorization flags from Scope (S) to S, this is not done
7118 -- when Scope (S) is Standard_Standard since propagation is from
7119 -- library unit entity inwards. Copy other relevant attributes as
7120 -- well (Discard_Names in particular).
7122 -- We only propagate inwards for library level entities,
7123 -- inner level subprograms do not inherit the categorization.
7125 if Is_Library_Level_Entity (S) then
7126 Set_Is_Preelaborated (S, Is_Preelaborated (E));
7127 Set_Is_Shared_Passive (S, Is_Shared_Passive (E));
7128 Set_Discard_Names (S, Discard_Names (E));
7129 Set_Suppress_Value_Tracking_On_Call
7130 (S, Suppress_Value_Tracking_On_Call (E));
7131 Set_Categorization_From_Scope (E => S, Scop => E);
7135 if Is_Child_Unit (S)
7136 and then Present (E)
7137 and then Ekind_In (E, E_Package, E_Generic_Package)
7139 Nkind (Parent (Unit_Declaration_Node (E))) = N_Compilation_Unit
7142 Aux : constant Node_Id :=
7143 Aux_Decls_Node (Parent (Unit_Declaration_Node (E)));
7145 if Present (Default_Storage_Pool (Aux)) then
7146 Default_Pool := Default_Storage_Pool (Aux);
7152 ---------------------
7153 -- Premature_Usage --
7154 ---------------------
7156 procedure Premature_Usage (N : Node_Id) is
7157 Kind : constant Node_Kind := Nkind (Parent (Entity (N)));
7158 E : Entity_Id := Entity (N);
7161 -- Within an instance, the analysis of the actual for a formal object
7162 -- does not see the name of the object itself. This is significant only
7163 -- if the object is an aggregate, where its analysis does not do any
7164 -- name resolution on component associations. (see 4717-008). In such a
7165 -- case, look for the visible homonym on the chain.
7168 and then Present (Homonym (E))
7173 and then not In_Open_Scopes (Scope (E))
7180 Set_Etype (N, Etype (E));
7185 if Kind = N_Component_Declaration then
7187 ("component&! cannot be used before end of record declaration", N);
7189 elsif Kind = N_Parameter_Specification then
7191 ("formal parameter&! cannot be used before end of specification",
7194 elsif Kind = N_Discriminant_Specification then
7196 ("discriminant&! cannot be used before end of discriminant part",
7199 elsif Kind = N_Procedure_Specification
7200 or else Kind = N_Function_Specification
7203 ("subprogram&! cannot be used before end of its declaration",
7206 elsif Kind = N_Full_Type_Declaration then
7208 ("type& cannot be used before end of its declaration!", N);
7212 ("object& cannot be used before end of its declaration!", N);
7214 end Premature_Usage;
7216 ------------------------
7217 -- Present_System_Aux --
7218 ------------------------
7220 function Present_System_Aux (N : Node_Id := Empty) return Boolean is
7222 Aux_Name : Unit_Name_Type;
7223 Unum : Unit_Number_Type;
7228 function Find_System (C_Unit : Node_Id) return Entity_Id;
7229 -- Scan context clause of compilation unit to find with_clause
7236 function Find_System (C_Unit : Node_Id) return Entity_Id is
7237 With_Clause : Node_Id;
7240 With_Clause := First (Context_Items (C_Unit));
7241 while Present (With_Clause) loop
7242 if (Nkind (With_Clause) = N_With_Clause
7243 and then Chars (Name (With_Clause)) = Name_System)
7244 and then Comes_From_Source (With_Clause)
7255 -- Start of processing for Present_System_Aux
7258 -- The child unit may have been loaded and analyzed already
7260 if Present (System_Aux_Id) then
7263 -- If no previous pragma for System.Aux, nothing to load
7265 elsif No (System_Extend_Unit) then
7268 -- Use the unit name given in the pragma to retrieve the unit.
7269 -- Verify that System itself appears in the context clause of the
7270 -- current compilation. If System is not present, an error will
7271 -- have been reported already.
7274 With_Sys := Find_System (Cunit (Current_Sem_Unit));
7276 The_Unit := Unit (Cunit (Current_Sem_Unit));
7280 (Nkind (The_Unit) = N_Package_Body
7281 or else (Nkind (The_Unit) = N_Subprogram_Body
7283 not Acts_As_Spec (Cunit (Current_Sem_Unit))))
7285 With_Sys := Find_System (Library_Unit (Cunit (Current_Sem_Unit)));
7289 and then Present (N)
7291 -- If we are compiling a subunit, we need to examine its
7292 -- context as well (Current_Sem_Unit is the parent unit);
7294 The_Unit := Parent (N);
7295 while Nkind (The_Unit) /= N_Compilation_Unit loop
7296 The_Unit := Parent (The_Unit);
7299 if Nkind (Unit (The_Unit)) = N_Subunit then
7300 With_Sys := Find_System (The_Unit);
7304 if No (With_Sys) then
7308 Loc := Sloc (With_Sys);
7309 Get_Name_String (Chars (Expression (System_Extend_Unit)));
7310 Name_Buffer (8 .. Name_Len + 7) := Name_Buffer (1 .. Name_Len);
7311 Name_Buffer (1 .. 7) := "system.";
7312 Name_Buffer (Name_Len + 8) := '%';
7313 Name_Buffer (Name_Len + 9) := 's';
7314 Name_Len := Name_Len + 9;
7315 Aux_Name := Name_Find;
7319 (Load_Name => Aux_Name,
7322 Error_Node => With_Sys);
7324 if Unum /= No_Unit then
7325 Semantics (Cunit (Unum));
7327 Defining_Entity (Specification (Unit (Cunit (Unum))));
7330 Make_With_Clause (Loc,
7332 Make_Expanded_Name (Loc,
7333 Chars => Chars (System_Aux_Id),
7334 Prefix => New_Reference_To (Scope (System_Aux_Id), Loc),
7335 Selector_Name => New_Reference_To (System_Aux_Id, Loc)));
7337 Set_Entity (Name (Withn), System_Aux_Id);
7339 Set_Library_Unit (Withn, Cunit (Unum));
7340 Set_Corresponding_Spec (Withn, System_Aux_Id);
7341 Set_First_Name (Withn, True);
7342 Set_Implicit_With (Withn, True);
7344 Insert_After (With_Sys, Withn);
7345 Mark_Rewrite_Insertion (Withn);
7346 Set_Context_Installed (Withn);
7350 -- Here if unit load failed
7353 Error_Msg_Name_1 := Name_System;
7354 Error_Msg_Name_2 := Chars (Expression (System_Extend_Unit));
7356 ("extension package `%.%` does not exist",
7357 Opt.System_Extend_Unit);
7361 end Present_System_Aux;
7363 -------------------------
7364 -- Restore_Scope_Stack --
7365 -------------------------
7367 procedure Restore_Scope_Stack (Handle_Use : Boolean := True) is
7370 Comp_Unit : Node_Id;
7371 In_Child : Boolean := False;
7372 Full_Vis : Boolean := True;
7373 SS_Last : constant Int := Scope_Stack.Last;
7376 -- Restore visibility of previous scope stack, if any
7378 for J in reverse 0 .. Scope_Stack.Last loop
7379 exit when Scope_Stack.Table (J).Entity = Standard_Standard
7380 or else No (Scope_Stack.Table (J).Entity);
7382 S := Scope_Stack.Table (J).Entity;
7384 if not Is_Hidden_Open_Scope (S) then
7386 -- If the parent scope is hidden, its entities are hidden as
7387 -- well, unless the entity is the instantiation currently
7390 if not Is_Hidden_Open_Scope (Scope (S))
7391 or else not Analyzed (Parent (S))
7392 or else Scope (S) = Standard_Standard
7394 Set_Is_Immediately_Visible (S, True);
7397 E := First_Entity (S);
7398 while Present (E) loop
7399 if Is_Child_Unit (E) then
7400 if not From_With_Type (E) then
7401 Set_Is_Immediately_Visible (E,
7402 Is_Visible_Child_Unit (E) or else In_Open_Scopes (E));
7406 (Nkind (Parent (E)) = N_Defining_Program_Unit_Name
7408 Nkind (Parent (Parent (E))) = N_Package_Specification);
7409 Set_Is_Immediately_Visible (E,
7410 Limited_View_Installed (Parent (Parent (E))));
7413 Set_Is_Immediately_Visible (E, True);
7419 and then Is_Package_Or_Generic_Package (S)
7421 -- We are in the visible part of the package scope
7423 exit when E = First_Private_Entity (S);
7427 -- The visibility of child units (siblings of current compilation)
7428 -- must be restored in any case. Their declarations may appear
7429 -- after the private part of the parent.
7431 if not Full_Vis then
7432 while Present (E) loop
7433 if Is_Child_Unit (E) then
7434 Set_Is_Immediately_Visible (E,
7435 Is_Visible_Child_Unit (E) or else In_Open_Scopes (E));
7443 if Is_Child_Unit (S)
7444 and not In_Child -- check only for current unit
7448 -- Restore visibility of parents according to whether the child
7449 -- is private and whether we are in its visible part.
7451 Comp_Unit := Parent (Unit_Declaration_Node (S));
7453 if Nkind (Comp_Unit) = N_Compilation_Unit
7454 and then Private_Present (Comp_Unit)
7458 elsif Is_Package_Or_Generic_Package (S)
7459 and then (In_Private_Part (S) or else In_Package_Body (S))
7463 -- if S is the scope of some instance (which has already been
7464 -- seen on the stack) it does not affect the visibility of
7467 elsif Is_Hidden_Open_Scope (S) then
7470 elsif (Ekind (S) = E_Procedure
7471 or else Ekind (S) = E_Function)
7472 and then Has_Completion (S)
7483 if SS_Last >= Scope_Stack.First
7484 and then Scope_Stack.Table (SS_Last).Entity /= Standard_Standard
7487 Install_Use_Clauses (Scope_Stack.Table (SS_Last).First_Use_Clause);
7489 end Restore_Scope_Stack;
7491 ----------------------
7492 -- Save_Scope_Stack --
7493 ----------------------
7495 procedure Save_Scope_Stack (Handle_Use : Boolean := True) is
7498 SS_Last : constant Int := Scope_Stack.Last;
7501 if SS_Last >= Scope_Stack.First
7502 and then Scope_Stack.Table (SS_Last).Entity /= Standard_Standard
7505 End_Use_Clauses (Scope_Stack.Table (SS_Last).First_Use_Clause);
7508 -- If the call is from within a compilation unit, as when called from
7509 -- Rtsfind, make current entries in scope stack invisible while we
7510 -- analyze the new unit.
7512 for J in reverse 0 .. SS_Last loop
7513 exit when Scope_Stack.Table (J).Entity = Standard_Standard
7514 or else No (Scope_Stack.Table (J).Entity);
7516 S := Scope_Stack.Table (J).Entity;
7517 Set_Is_Immediately_Visible (S, False);
7519 E := First_Entity (S);
7520 while Present (E) loop
7521 Set_Is_Immediately_Visible (E, False);
7527 end Save_Scope_Stack;
7533 procedure Set_Use (L : List_Id) is
7535 Pack_Name : Node_Id;
7542 while Present (Decl) loop
7543 if Nkind (Decl) = N_Use_Package_Clause then
7544 Chain_Use_Clause (Decl);
7546 Pack_Name := First (Names (Decl));
7547 while Present (Pack_Name) loop
7548 Pack := Entity (Pack_Name);
7550 if Ekind (Pack) = E_Package
7551 and then Applicable_Use (Pack_Name)
7553 Use_One_Package (Pack, Decl);
7559 elsif Nkind (Decl) = N_Use_Type_Clause then
7560 Chain_Use_Clause (Decl);
7562 Id := First (Subtype_Marks (Decl));
7563 while Present (Id) loop
7564 if Entity (Id) /= Any_Type then
7577 ---------------------
7578 -- Use_One_Package --
7579 ---------------------
7581 procedure Use_One_Package (P : Entity_Id; N : Node_Id) is
7584 Current_Instance : Entity_Id := Empty;
7586 Private_With_OK : Boolean := False;
7589 if Ekind (P) /= E_Package then
7594 Set_Current_Use_Clause (P, N);
7596 -- Ada 2005 (AI-50217): Check restriction
7598 if From_With_Type (P) then
7599 Error_Msg_N ("limited withed package cannot appear in use clause", N);
7602 -- Find enclosing instance, if any
7605 Current_Instance := Current_Scope;
7606 while not Is_Generic_Instance (Current_Instance) loop
7607 Current_Instance := Scope (Current_Instance);
7610 if No (Hidden_By_Use_Clause (N)) then
7611 Set_Hidden_By_Use_Clause (N, New_Elmt_List);
7615 -- If unit is a package renaming, indicate that the renamed
7616 -- package is also in use (the flags on both entities must
7617 -- remain consistent, and a subsequent use of either of them
7618 -- should be recognized as redundant).
7620 if Present (Renamed_Object (P)) then
7621 Set_In_Use (Renamed_Object (P));
7622 Set_Current_Use_Clause (Renamed_Object (P), N);
7623 Real_P := Renamed_Object (P);
7628 -- Ada 2005 (AI-262): Check the use_clause of a private withed package
7629 -- found in the private part of a package specification
7631 if In_Private_Part (Current_Scope)
7632 and then Has_Private_With (P)
7633 and then Is_Child_Unit (Current_Scope)
7634 and then Is_Child_Unit (P)
7635 and then Is_Ancestor_Package (Scope (Current_Scope), P)
7637 Private_With_OK := True;
7640 -- Loop through entities in one package making them potentially
7643 Id := First_Entity (P);
7645 and then (Id /= First_Private_Entity (P)
7646 or else Private_With_OK) -- Ada 2005 (AI-262)
7648 Prev := Current_Entity (Id);
7649 while Present (Prev) loop
7650 if Is_Immediately_Visible (Prev)
7651 and then (not Is_Overloadable (Prev)
7652 or else not Is_Overloadable (Id)
7653 or else (Type_Conformant (Id, Prev)))
7655 if No (Current_Instance) then
7657 -- Potentially use-visible entity remains hidden
7659 goto Next_Usable_Entity;
7661 -- A use clause within an instance hides outer global entities,
7662 -- which are not used to resolve local entities in the
7663 -- instance. Note that the predefined entities in Standard
7664 -- could not have been hidden in the generic by a use clause,
7665 -- and therefore remain visible. Other compilation units whose
7666 -- entities appear in Standard must be hidden in an instance.
7668 -- To determine whether an entity is external to the instance
7669 -- we compare the scope depth of its scope with that of the
7670 -- current instance. However, a generic actual of a subprogram
7671 -- instance is declared in the wrapper package but will not be
7672 -- hidden by a use-visible entity. similarly, an entity that is
7673 -- declared in an enclosing instance will not be hidden by an
7674 -- an entity declared in a generic actual, which can only have
7675 -- been use-visible in the generic and will not have hidden the
7676 -- entity in the generic parent.
7678 -- If Id is called Standard, the predefined package with the
7679 -- same name is in the homonym chain. It has to be ignored
7680 -- because it has no defined scope (being the only entity in
7681 -- the system with this mandated behavior).
7683 elsif not Is_Hidden (Id)
7684 and then Present (Scope (Prev))
7685 and then not Is_Wrapper_Package (Scope (Prev))
7686 and then Scope_Depth (Scope (Prev)) <
7687 Scope_Depth (Current_Instance)
7688 and then (Scope (Prev) /= Standard_Standard
7689 or else Sloc (Prev) > Standard_Location)
7691 if In_Open_Scopes (Scope (Prev))
7692 and then Is_Generic_Instance (Scope (Prev))
7693 and then Present (Associated_Formal_Package (P))
7698 Set_Is_Potentially_Use_Visible (Id);
7699 Set_Is_Immediately_Visible (Prev, False);
7700 Append_Elmt (Prev, Hidden_By_Use_Clause (N));
7704 -- A user-defined operator is not use-visible if the predefined
7705 -- operator for the type is immediately visible, which is the case
7706 -- if the type of the operand is in an open scope. This does not
7707 -- apply to user-defined operators that have operands of different
7708 -- types, because the predefined mixed mode operations (multiply
7709 -- and divide) apply to universal types and do not hide anything.
7711 elsif Ekind (Prev) = E_Operator
7712 and then Operator_Matches_Spec (Prev, Id)
7713 and then In_Open_Scopes
7714 (Scope (Base_Type (Etype (First_Formal (Id)))))
7715 and then (No (Next_Formal (First_Formal (Id)))
7716 or else Etype (First_Formal (Id))
7717 = Etype (Next_Formal (First_Formal (Id)))
7718 or else Chars (Prev) = Name_Op_Expon)
7720 goto Next_Usable_Entity;
7722 -- In an instance, two homonyms may become use_visible through the
7723 -- actuals of distinct formal packages. In the generic, only the
7724 -- current one would have been visible, so make the other one
7727 elsif Present (Current_Instance)
7728 and then Is_Potentially_Use_Visible (Prev)
7729 and then not Is_Overloadable (Prev)
7730 and then Scope (Id) /= Scope (Prev)
7731 and then Used_As_Generic_Actual (Scope (Prev))
7732 and then Used_As_Generic_Actual (Scope (Id))
7733 and then not In_Same_List (Current_Use_Clause (Scope (Prev)),
7734 Current_Use_Clause (Scope (Id)))
7736 Set_Is_Potentially_Use_Visible (Prev, False);
7737 Append_Elmt (Prev, Hidden_By_Use_Clause (N));
7740 Prev := Homonym (Prev);
7743 -- On exit, we know entity is not hidden, unless it is private
7745 if not Is_Hidden (Id)
7746 and then ((not Is_Child_Unit (Id))
7747 or else Is_Visible_Child_Unit (Id))
7749 Set_Is_Potentially_Use_Visible (Id);
7751 if Is_Private_Type (Id)
7752 and then Present (Full_View (Id))
7754 Set_Is_Potentially_Use_Visible (Full_View (Id));
7758 <<Next_Usable_Entity>>
7762 -- Child units are also made use-visible by a use clause, but they may
7763 -- appear after all visible declarations in the parent entity list.
7765 while Present (Id) loop
7766 if Is_Child_Unit (Id)
7767 and then Is_Visible_Child_Unit (Id)
7769 Set_Is_Potentially_Use_Visible (Id);
7775 if Chars (Real_P) = Name_System
7776 and then Scope (Real_P) = Standard_Standard
7777 and then Present_System_Aux (N)
7779 Use_One_Package (System_Aux_Id, N);
7782 end Use_One_Package;
7788 procedure Use_One_Type (Id : Node_Id; Installed : Boolean := False) is
7790 Is_Known_Used : Boolean;
7794 function Spec_Reloaded_For_Body return Boolean;
7795 -- Determine whether the compilation unit is a package body and the use
7796 -- type clause is in the spec of the same package. Even though the spec
7797 -- was analyzed first, its context is reloaded when analysing the body.
7799 procedure Use_Class_Wide_Operations (Typ : Entity_Id);
7800 -- AI05-150: if the use_type_clause carries the "all" qualifier,
7801 -- class-wide operations of ancestor types are use-visible if the
7802 -- ancestor type is visible.
7804 ----------------------------
7805 -- Spec_Reloaded_For_Body --
7806 ----------------------------
7808 function Spec_Reloaded_For_Body return Boolean is
7810 if Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Body then
7812 Spec : constant Node_Id :=
7813 Parent (List_Containing (Parent (Id)));
7816 Nkind (Spec) = N_Package_Specification
7817 and then Corresponding_Body (Parent (Spec)) =
7818 Cunit_Entity (Current_Sem_Unit);
7823 end Spec_Reloaded_For_Body;
7825 -------------------------------
7826 -- Use_Class_Wide_Operations --
7827 -------------------------------
7829 procedure Use_Class_Wide_Operations (Typ : Entity_Id) is
7833 function Is_Class_Wide_Operation_Of
7835 T : Entity_Id) return Boolean;
7836 -- Determine whether a subprogram has a class-wide parameter or
7837 -- result that is T'Class.
7839 ---------------------------------
7840 -- Is_Class_Wide_Operation_Of --
7841 ---------------------------------
7843 function Is_Class_Wide_Operation_Of
7845 T : Entity_Id) return Boolean
7850 Formal := First_Formal (Op);
7851 while Present (Formal) loop
7852 if Etype (Formal) = Class_Wide_Type (T) then
7855 Next_Formal (Formal);
7858 if Etype (Op) = Class_Wide_Type (T) then
7863 end Is_Class_Wide_Operation_Of;
7865 -- Start of processing for Use_Class_Wide_Operations
7868 Scop := Scope (Typ);
7869 if not Is_Hidden (Scop) then
7870 Ent := First_Entity (Scop);
7871 while Present (Ent) loop
7872 if Is_Overloadable (Ent)
7873 and then Is_Class_Wide_Operation_Of (Ent, Typ)
7874 and then not Is_Potentially_Use_Visible (Ent)
7876 Set_Is_Potentially_Use_Visible (Ent);
7877 Append_Elmt (Ent, Used_Operations (Parent (Id)));
7884 if Is_Derived_Type (Typ) then
7885 Use_Class_Wide_Operations (Etype (Base_Type (Typ)));
7887 end Use_Class_Wide_Operations;
7889 -- Start of processing for Use_One_Type;
7892 -- It is the type determined by the subtype mark (8.4(8)) whose
7893 -- operations become potentially use-visible.
7895 T := Base_Type (Entity (Id));
7897 -- Either the type itself is used, the package where it is declared
7898 -- is in use or the entity is declared in the current package, thus
7903 or else In_Use (Scope (T))
7904 or else Scope (T) = Current_Scope;
7906 Set_Redundant_Use (Id,
7907 Is_Known_Used or else Is_Potentially_Use_Visible (T));
7909 if Ekind (T) = E_Incomplete_Type then
7910 Error_Msg_N ("premature usage of incomplete type", Id);
7912 elsif In_Open_Scopes (Scope (T)) then
7915 -- A limited view cannot appear in a use_type clause. However, an access
7916 -- type whose designated type is limited has the flag but is not itself
7917 -- a limited view unless we only have a limited view of its enclosing
7920 elsif From_With_Type (T)
7921 and then From_With_Type (Scope (T))
7924 ("incomplete type from limited view "
7925 & "cannot appear in use clause", Id);
7927 -- If the subtype mark designates a subtype in a different package,
7928 -- we have to check that the parent type is visible, otherwise the
7929 -- use type clause is a noop. Not clear how to do that???
7931 elsif not Redundant_Use (Id) then
7934 -- If T is tagged, primitive operators on class-wide operands
7935 -- are also available.
7937 if Is_Tagged_Type (T) then
7938 Set_In_Use (Class_Wide_Type (T));
7941 Set_Current_Use_Clause (T, Parent (Id));
7943 -- Iterate over primitive operations of the type. If an operation is
7944 -- already use_visible, it is the result of a previous use_clause,
7945 -- and already appears on the corresponding entity chain. If the
7946 -- clause is being reinstalled, operations are already use-visible.
7952 Op_List := Collect_Primitive_Operations (T);
7953 Elmt := First_Elmt (Op_List);
7954 while Present (Elmt) loop
7955 if (Nkind (Node (Elmt)) = N_Defining_Operator_Symbol
7956 or else Chars (Node (Elmt)) in Any_Operator_Name)
7957 and then not Is_Hidden (Node (Elmt))
7958 and then not Is_Potentially_Use_Visible (Node (Elmt))
7960 Set_Is_Potentially_Use_Visible (Node (Elmt));
7961 Append_Elmt (Node (Elmt), Used_Operations (Parent (Id)));
7963 elsif Ada_Version >= Ada_2012
7964 and then All_Present (Parent (Id))
7965 and then not Is_Hidden (Node (Elmt))
7966 and then not Is_Potentially_Use_Visible (Node (Elmt))
7968 Set_Is_Potentially_Use_Visible (Node (Elmt));
7969 Append_Elmt (Node (Elmt), Used_Operations (Parent (Id)));
7976 if Ada_Version >= Ada_2012
7977 and then All_Present (Parent (Id))
7978 and then Is_Tagged_Type (T)
7980 Use_Class_Wide_Operations (T);
7984 -- If warning on redundant constructs, check for unnecessary WITH
7986 if Warn_On_Redundant_Constructs
7987 and then Is_Known_Used
7989 -- with P; with P; use P;
7990 -- package P is package X is package body X is
7991 -- type T ... use P.T;
7993 -- The compilation unit is the body of X. GNAT first compiles the
7994 -- spec of X, then proceeds to the body. At that point P is marked
7995 -- as use visible. The analysis then reinstalls the spec along with
7996 -- its context. The use clause P.T is now recognized as redundant,
7997 -- but in the wrong context. Do not emit a warning in such cases.
7998 -- Do not emit a warning either if we are in an instance, there is
7999 -- no redundancy between an outer use_clause and one that appears
8000 -- within the generic.
8002 and then not Spec_Reloaded_For_Body
8003 and then not In_Instance
8005 -- The type already has a use clause
8009 -- Case where we know the current use clause for the type
8011 if Present (Current_Use_Clause (T)) then
8012 Use_Clause_Known : declare
8013 Clause1 : constant Node_Id := Parent (Id);
8014 Clause2 : constant Node_Id := Current_Use_Clause (T);
8021 function Entity_Of_Unit (U : Node_Id) return Entity_Id;
8022 -- Return the appropriate entity for determining which unit
8023 -- has a deeper scope: the defining entity for U, unless U
8024 -- is a package instance, in which case we retrieve the
8025 -- entity of the instance spec.
8027 --------------------
8028 -- Entity_Of_Unit --
8029 --------------------
8031 function Entity_Of_Unit (U : Node_Id) return Entity_Id is
8033 if Nkind (U) = N_Package_Instantiation
8034 and then Analyzed (U)
8036 return Defining_Entity (Instance_Spec (U));
8038 return Defining_Entity (U);
8042 -- Start of processing for Use_Clause_Known
8045 -- If both current use type clause and the use type clause
8046 -- for the type are at the compilation unit level, one of
8047 -- the units must be an ancestor of the other, and the
8048 -- warning belongs on the descendant.
8050 if Nkind (Parent (Clause1)) = N_Compilation_Unit
8052 Nkind (Parent (Clause2)) = N_Compilation_Unit
8055 -- If the unit is a subprogram body that acts as spec,
8056 -- the context clause is shared with the constructed
8057 -- subprogram spec. Clearly there is no redundancy.
8059 if Clause1 = Clause2 then
8063 Unit1 := Unit (Parent (Clause1));
8064 Unit2 := Unit (Parent (Clause2));
8066 -- If both clauses are on same unit, or one is the body
8067 -- of the other, or one of them is in a subunit, report
8068 -- redundancy on the later one.
8070 if Unit1 = Unit2 then
8071 Error_Msg_Sloc := Sloc (Current_Use_Clause (T));
8072 Error_Msg_NE -- CODEFIX
8073 ("& is already use-visible through previous "
8074 & "use_type_clause #?", Clause1, T);
8077 elsif Nkind (Unit1) = N_Subunit then
8078 Error_Msg_Sloc := Sloc (Current_Use_Clause (T));
8079 Error_Msg_NE -- CODEFIX
8080 ("& is already use-visible through previous "
8081 & "use_type_clause #?", Clause1, T);
8084 elsif Nkind_In (Unit2, N_Package_Body, N_Subprogram_Body)
8085 and then Nkind (Unit1) /= Nkind (Unit2)
8086 and then Nkind (Unit1) /= N_Subunit
8088 Error_Msg_Sloc := Sloc (Clause1);
8089 Error_Msg_NE -- CODEFIX
8090 ("& is already use-visible through previous "
8091 & "use_type_clause #?", Current_Use_Clause (T), T);
8095 -- There is a redundant use type clause in a child unit.
8096 -- Determine which of the units is more deeply nested.
8097 -- If a unit is a package instance, retrieve the entity
8098 -- and its scope from the instance spec.
8100 Ent1 := Entity_Of_Unit (Unit1);
8101 Ent2 := Entity_Of_Unit (Unit2);
8103 if Scope (Ent2) = Standard_Standard then
8104 Error_Msg_Sloc := Sloc (Current_Use_Clause (T));
8107 elsif Scope (Ent1) = Standard_Standard then
8108 Error_Msg_Sloc := Sloc (Id);
8111 -- If both units are child units, we determine which one
8112 -- is the descendant by the scope distance to the
8113 -- ultimate parent unit.
8123 and then Present (S2)
8124 and then S1 /= Standard_Standard
8125 and then S2 /= Standard_Standard
8131 if S1 = Standard_Standard then
8132 Error_Msg_Sloc := Sloc (Id);
8135 Error_Msg_Sloc := Sloc (Current_Use_Clause (T));
8141 Error_Msg_NE -- CODEFIX
8142 ("& is already use-visible through previous "
8143 & "use_type_clause #?", Err_No, Id);
8145 -- Case where current use type clause and the use type
8146 -- clause for the type are not both at the compilation unit
8147 -- level. In this case we don't have location information.
8150 Error_Msg_NE -- CODEFIX
8151 ("& is already use-visible through previous "
8152 & "use type clause?", Id, T);
8154 end Use_Clause_Known;
8156 -- Here if Current_Use_Clause is not set for T, another case
8157 -- where we do not have the location information available.
8160 Error_Msg_NE -- CODEFIX
8161 ("& is already use-visible through previous "
8162 & "use type clause?", Id, T);
8165 -- The package where T is declared is already used
8167 elsif In_Use (Scope (T)) then
8168 Error_Msg_Sloc := Sloc (Current_Use_Clause (Scope (T)));
8169 Error_Msg_NE -- CODEFIX
8170 ("& is already use-visible through package use clause #?",
8173 -- The current scope is the package where T is declared
8176 Error_Msg_Node_2 := Scope (T);
8177 Error_Msg_NE -- CODEFIX
8178 ("& is already use-visible inside package &?", Id, T);
8187 procedure Write_Info is
8188 Id : Entity_Id := First_Entity (Current_Scope);
8191 -- No point in dumping standard entities
8193 if Current_Scope = Standard_Standard then
8197 Write_Str ("========================================================");
8199 Write_Str (" Defined Entities in ");
8200 Write_Name (Chars (Current_Scope));
8202 Write_Str ("========================================================");
8206 Write_Str ("-- none --");
8210 while Present (Id) loop
8211 Write_Entity_Info (Id, " ");
8216 if Scope (Current_Scope) = Standard_Standard then
8218 -- Print information on the current unit itself
8220 Write_Entity_Info (Current_Scope, " ");
8233 for J in reverse 1 .. Scope_Stack.Last loop
8234 S := Scope_Stack.Table (J).Entity;
8235 Write_Int (Int (S));
8236 Write_Str (" === ");
8237 Write_Name (Chars (S));
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