1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2008, 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_Cat; use Sem_Cat;
50 with Sem_Ch3; use Sem_Ch3;
51 with Sem_Ch4; use Sem_Ch4;
52 with Sem_Ch6; use Sem_Ch6;
53 with Sem_Ch12; use Sem_Ch12;
54 with Sem_Disp; use Sem_Disp;
55 with Sem_Dist; use Sem_Dist;
56 with Sem_Res; use Sem_Res;
57 with Sem_Util; use Sem_Util;
58 with Sem_Type; use Sem_Type;
59 with Stand; use Stand;
60 with Sinfo; use Sinfo;
61 with Sinfo.CN; use Sinfo.CN;
62 with Snames; use Snames;
63 with Style; use Style;
65 with Tbuild; use Tbuild;
66 with Uintp; use Uintp;
68 package body Sem_Ch8 is
70 ------------------------------------
71 -- Visibility and Name Resolution --
72 ------------------------------------
74 -- This package handles name resolution and the collection of
75 -- interpretations for overloaded names, prior to overload resolution.
77 -- Name resolution is the process that establishes a mapping between source
78 -- identifiers and the entities they denote at each point in the program.
79 -- Each entity is represented by a defining occurrence. Each identifier
80 -- that denotes an entity points to the corresponding defining occurrence.
81 -- This is the entity of the applied occurrence. Each occurrence holds
82 -- an index into the names table, where source identifiers are stored.
84 -- Each entry in the names table for an identifier or designator uses the
85 -- Info pointer to hold a link to the currently visible entity that has
86 -- this name (see subprograms Get_Name_Entity_Id and Set_Name_Entity_Id
87 -- in package Sem_Util). The visibility is initialized at the beginning of
88 -- semantic processing to make entities in package Standard immediately
89 -- visible. The visibility table is used in a more subtle way when
90 -- compiling subunits (see below).
92 -- Entities that have the same name (i.e. homonyms) are chained. In the
93 -- case of overloaded entities, this chain holds all the possible meanings
94 -- of a given identifier. The process of overload resolution uses type
95 -- information to select from this chain the unique meaning of a given
98 -- Entities are also chained in their scope, through the Next_Entity link.
99 -- As a consequence, the name space is organized as a sparse matrix, where
100 -- each row corresponds to a scope, and each column to a source identifier.
101 -- Open scopes, that is to say scopes currently being compiled, have their
102 -- corresponding rows of entities in order, innermost scope first.
104 -- The scopes of packages that are mentioned in context clauses appear in
105 -- no particular order, interspersed among open scopes. This is because
106 -- in the course of analyzing the context of a compilation, a package
107 -- declaration is first an open scope, and subsequently an element of the
108 -- context. If subunits or child units are present, a parent unit may
109 -- appear under various guises at various times in the compilation.
111 -- When the compilation of the innermost scope is complete, the entities
112 -- defined therein are no longer visible. If the scope is not a package
113 -- declaration, these entities are never visible subsequently, and can be
114 -- removed from visibility chains. If the scope is a package declaration,
115 -- its visible declarations may still be accessible. Therefore the entities
116 -- defined in such a scope are left on the visibility chains, and only
117 -- their visibility (immediately visibility or potential use-visibility)
120 -- The ordering of homonyms on their chain does not necessarily follow
121 -- the order of their corresponding scopes on the scope stack. For
122 -- example, if package P and the enclosing scope both contain entities
123 -- named E, then when compiling the package body the chain for E will
124 -- hold the global entity first, and the local one (corresponding to
125 -- the current inner scope) next. As a result, name resolution routines
126 -- do not assume any relative ordering of the homonym chains, either
127 -- for scope nesting or to order of appearance of context clauses.
129 -- When compiling a child unit, entities in the parent scope are always
130 -- immediately visible. When compiling the body of a child unit, private
131 -- entities in the parent must also be made immediately visible. There
132 -- are separate routines to make the visible and private declarations
133 -- visible at various times (see package Sem_Ch7).
135 -- +--------+ +-----+
136 -- | In use |-------->| EU1 |-------------------------->
137 -- +--------+ +-----+
139 -- +--------+ +-----+ +-----+
140 -- | Stand. |---------------->| ES1 |--------------->| ES2 |--->
141 -- +--------+ +-----+ +-----+
143 -- +---------+ | +-----+
144 -- | with'ed |------------------------------>| EW2 |--->
145 -- +---------+ | +-----+
147 -- +--------+ +-----+ +-----+
148 -- | Scope2 |---------------->| E12 |--------------->| E22 |--->
149 -- +--------+ +-----+ +-----+
151 -- +--------+ +-----+ +-----+
152 -- | Scope1 |---------------->| E11 |--------------->| E12 |--->
153 -- +--------+ +-----+ +-----+
157 -- | | with'ed |----------------------------------------->
161 -- (innermost first) | |
162 -- +----------------------------+
163 -- Names table => | Id1 | | | | Id2 |
164 -- +----------------------------+
166 -- Name resolution must deal with several syntactic forms: simple names,
167 -- qualified names, indexed names, and various forms of calls.
169 -- Each identifier points to an entry in the names table. The resolution
170 -- of a simple name consists in traversing the homonym chain, starting
171 -- from the names table. If an entry is immediately visible, it is the one
172 -- designated by the identifier. If only potentially use-visible entities
173 -- are on the chain, we must verify that they do not hide each other. If
174 -- the entity we find is overloadable, we collect all other overloadable
175 -- entities on the chain as long as they are not hidden.
177 -- To resolve expanded names, we must find the entity at the intersection
178 -- of the entity chain for the scope (the prefix) and the homonym chain
179 -- for the selector. In general, homonym chains will be much shorter than
180 -- entity chains, so it is preferable to start from the names table as
181 -- well. If the entity found is overloadable, we must collect all other
182 -- interpretations that are defined in the scope denoted by the prefix.
184 -- For records, protected types, and tasks, their local entities are
185 -- removed from visibility chains on exit from the corresponding scope.
186 -- From the outside, these entities are always accessed by selected
187 -- notation, and the entity chain for the record type, protected type,
188 -- etc. is traversed sequentially in order to find the designated entity.
190 -- The discriminants of a type and the operations of a protected type or
191 -- task are unchained on exit from the first view of the type, (such as
192 -- a private or incomplete type declaration, or a protected type speci-
193 -- fication) and re-chained when compiling the second view.
195 -- In the case of operators, we do not make operators on derived types
196 -- explicit. As a result, the notation P."+" may denote either a user-
197 -- defined function with name "+", or else an implicit declaration of the
198 -- operator "+" in package P. The resolution of expanded names always
199 -- tries to resolve an operator name as such an implicitly defined entity,
200 -- in addition to looking for explicit declarations.
202 -- All forms of names that denote entities (simple names, expanded names,
203 -- character literals in some cases) have a Entity attribute, which
204 -- identifies the entity denoted by the name.
206 ---------------------
207 -- The Scope Stack --
208 ---------------------
210 -- The Scope stack keeps track of the scopes currently been compiled.
211 -- Every entity that contains declarations (including records) is placed
212 -- on the scope stack while it is being processed, and removed at the end.
213 -- Whenever a non-package scope is exited, the entities defined therein
214 -- are removed from the visibility table, so that entities in outer scopes
215 -- become visible (see previous description). On entry to Sem, the scope
216 -- stack only contains the package Standard. As usual, subunits complicate
217 -- this picture ever so slightly.
219 -- The Rtsfind mechanism can force a call to Semantics while another
220 -- compilation is in progress. The unit retrieved by Rtsfind must be
221 -- compiled in its own context, and has no access to the visibility of
222 -- the unit currently being compiled. The procedures Save_Scope_Stack and
223 -- Restore_Scope_Stack make entities in current open scopes invisible
224 -- before compiling the retrieved unit, and restore the compilation
225 -- environment afterwards.
227 ------------------------
228 -- Compiling subunits --
229 ------------------------
231 -- Subunits must be compiled in the environment of the corresponding stub,
232 -- that is to say with the same visibility into the parent (and its
233 -- context) that is available at the point of the stub declaration, but
234 -- with the additional visibility provided by the context clause of the
235 -- subunit itself. As a result, compilation of a subunit forces compilation
236 -- of the parent (see description in lib-). At the point of the stub
237 -- declaration, Analyze is called recursively to compile the proper body of
238 -- the subunit, but without reinitializing the names table, nor the scope
239 -- stack (i.e. standard is not pushed on the stack). In this fashion the
240 -- context of the subunit is added to the context of the parent, and the
241 -- subunit is compiled in the correct environment. Note that in the course
242 -- of processing the context of a subunit, Standard will appear twice on
243 -- the scope stack: once for the parent of the subunit, and once for the
244 -- unit in the context clause being compiled. However, the two sets of
245 -- entities are not linked by homonym chains, so that the compilation of
246 -- any context unit happens in a fresh visibility environment.
248 -------------------------------
249 -- Processing of USE Clauses --
250 -------------------------------
252 -- Every defining occurrence has a flag indicating if it is potentially use
253 -- visible. Resolution of simple names examines this flag. The processing
254 -- of use clauses consists in setting this flag on all visible entities
255 -- defined in the corresponding package. On exit from the scope of the use
256 -- clause, the corresponding flag must be reset. However, a package may
257 -- appear in several nested use clauses (pathological but legal, alas!)
258 -- which forces us to use a slightly more involved scheme:
260 -- a) The defining occurrence for a package holds a flag -In_Use- to
261 -- indicate that it is currently in the scope of a use clause. If a
262 -- redundant use clause is encountered, then the corresponding occurrence
263 -- of the package name is flagged -Redundant_Use-.
265 -- b) On exit from a scope, the use clauses in its declarative part are
266 -- scanned. The visibility flag is reset in all entities declared in
267 -- package named in a use clause, as long as the package is not flagged
268 -- as being in a redundant use clause (in which case the outer use
269 -- clause is still in effect, and the direct visibility of its entities
270 -- must be retained).
272 -- Note that entities are not removed from their homonym chains on exit
273 -- from the package specification. A subsequent use clause does not need
274 -- to rechain the visible entities, but only to establish their direct
277 -----------------------------------
278 -- Handling private declarations --
279 -----------------------------------
281 -- The principle that each entity has a single defining occurrence clashes
282 -- with the presence of two separate definitions for private types: the
283 -- first is the private type declaration, and second is the full type
284 -- declaration. It is important that all references to the type point to
285 -- the same defining occurrence, namely the first one. To enforce the two
286 -- separate views of the entity, the corresponding information is swapped
287 -- between the two declarations. Outside of the package, the defining
288 -- occurrence only contains the private declaration information, while in
289 -- the private part and the body of the package the defining occurrence
290 -- contains the full declaration. To simplify the swap, the defining
291 -- occurrence that currently holds the private declaration points to the
292 -- full declaration. During semantic processing the defining occurrence
293 -- also points to a list of private dependents, that is to say access types
294 -- or composite types whose designated types or component types are
295 -- subtypes or derived types of the private type in question. After the
296 -- full declaration has been seen, the private dependents are updated to
297 -- indicate that they have full definitions.
299 ------------------------------------
300 -- Handling of Undefined Messages --
301 ------------------------------------
303 -- In normal mode, only the first use of an undefined identifier generates
304 -- a message. The table Urefs is used to record error messages that have
305 -- been issued so that second and subsequent ones do not generate further
306 -- messages. However, the second reference causes text to be added to the
307 -- original undefined message noting "(more references follow)". The
308 -- full error list option (-gnatf) forces messages to be generated for
309 -- every reference and disconnects the use of this table.
311 type Uref_Entry is record
313 -- Node for identifier for which original message was posted. The
314 -- Chars field of this identifier is used to detect later references
315 -- to the same identifier.
318 -- Records error message Id of original undefined message. Reset to
319 -- No_Error_Msg after the second occurrence, where it is used to add
320 -- text to the original message as described above.
323 -- Set if the message is not visible rather than undefined
326 -- Records location of error message. Used to make sure that we do
327 -- not consider a, b : undefined as two separate instances, which
328 -- would otherwise happen, since the parser converts this sequence
329 -- to a : undefined; b : undefined.
333 package Urefs is new Table.Table (
334 Table_Component_Type => Uref_Entry,
335 Table_Index_Type => Nat,
336 Table_Low_Bound => 1,
338 Table_Increment => 100,
339 Table_Name => "Urefs");
341 Candidate_Renaming : Entity_Id;
342 -- Holds a candidate interpretation that appears in a subprogram renaming
343 -- declaration and does not match the given specification, but matches at
344 -- least on the first formal. Allows better error message when given
345 -- specification omits defaulted parameters, a common error.
347 -----------------------
348 -- Local Subprograms --
349 -----------------------
351 procedure Analyze_Generic_Renaming
354 -- Common processing for all three kinds of generic renaming declarations.
355 -- Enter new name and indicate that it renames the generic unit.
357 procedure Analyze_Renamed_Character
361 -- Renamed entity is given by a character literal, which must belong
362 -- to the return type of the new entity. Is_Body indicates whether the
363 -- declaration is a renaming_as_body. If the original declaration has
364 -- already been frozen (because of an intervening body, e.g.) the body of
365 -- the function must be built now. The same applies to the following
366 -- various renaming procedures.
368 procedure Analyze_Renamed_Dereference
372 -- Renamed entity is given by an explicit dereference. Prefix must be a
373 -- conformant access_to_subprogram type.
375 procedure Analyze_Renamed_Entry
379 -- If the renamed entity in a subprogram renaming is an entry or protected
380 -- subprogram, build a body for the new entity whose only statement is a
381 -- call to the renamed entity.
383 procedure Analyze_Renamed_Family_Member
387 -- Used when the renamed entity is an indexed component. The prefix must
388 -- denote an entry family.
390 procedure Analyze_Renamed_Primitive_Operation
394 -- If the renamed entity in a subprogram renaming is a primitive operation
395 -- or a class-wide operation in prefix form, save the target object, which
396 -- must be added to the list of actuals in any subsequent call.
398 function Applicable_Use (Pack_Name : Node_Id) return Boolean;
399 -- Common code to Use_One_Package and Set_Use, to determine whether
400 -- use clause must be processed. Pack_Name is an entity name that
401 -- references the package in question.
403 procedure Attribute_Renaming (N : Node_Id);
404 -- Analyze renaming of attribute as function. The renaming declaration N
405 -- is rewritten as a function body that returns the attribute reference
406 -- applied to the formals of the function.
408 procedure Check_Frozen_Renaming (N : Node_Id; Subp : Entity_Id);
409 -- A renaming_as_body may occur after the entity of the original decla-
410 -- ration has been frozen. In that case, the body of the new entity must
411 -- be built now, because the usual mechanism of building the renamed
412 -- body at the point of freezing will not work. Subp is the subprogram
413 -- for which N provides the Renaming_As_Body.
415 procedure Check_In_Previous_With_Clause
418 -- N is a use_package clause and Nam the package name, or N is a use_type
419 -- clause and Nam is the prefix of the type name. In either case, verify
420 -- that the package is visible at that point in the context: either it
421 -- appears in a previous with_clause, or because it is a fully qualified
422 -- name and the root ancestor appears in a previous with_clause.
424 procedure Check_Library_Unit_Renaming (N : Node_Id; Old_E : Entity_Id);
425 -- Verify that the entity in a renaming declaration that is a library unit
426 -- is itself a library unit and not a nested unit or subunit. Also check
427 -- that if the renaming is a child unit of a generic parent, then the
428 -- renamed unit must also be a child unit of that parent. Finally, verify
429 -- that a renamed generic unit is not an implicit child declared within
430 -- an instance of the parent.
432 procedure Chain_Use_Clause (N : Node_Id);
433 -- Chain use clause onto list of uses clauses headed by First_Use_Clause in
434 -- the proper scope table entry. This is usually the current scope, but it
435 -- will be an inner scope when installing the use clauses of the private
436 -- declarations of a parent unit prior to compiling the private part of a
437 -- child unit. This chain is traversed when installing/removing use clauses
438 -- when compiling a subunit or instantiating a generic body on the fly,
439 -- when it is necessary to save and restore full environments.
441 function Has_Implicit_Character_Literal (N : Node_Id) return Boolean;
442 -- Find a type derived from Character or Wide_Character in the prefix of N.
443 -- Used to resolved qualified names whose selector is a character literal.
445 function Has_Private_With (E : Entity_Id) return Boolean;
446 -- Ada 2005 (AI-262): Determines if the current compilation unit has a
447 -- private with on E.
449 procedure Find_Expanded_Name (N : Node_Id);
450 -- Selected component is known to be expanded name. Verify legality
451 -- of selector given the scope denoted by prefix.
453 function Find_Renamed_Entity
457 Is_Actual : Boolean := False) return Entity_Id;
458 -- Find the renamed entity that corresponds to the given parameter profile
459 -- in a subprogram renaming declaration. The renamed entity may be an
460 -- operator, a subprogram, an entry, or a protected operation. Is_Actual
461 -- indicates that the renaming is the one generated for an actual subpro-
462 -- gram in an instance, for which special visibility checks apply.
464 function Has_Implicit_Operator (N : Node_Id) return Boolean;
465 -- N is an expanded name whose selector is an operator name (e.g. P."+").
466 -- declarative part contains an implicit declaration of an operator if it
467 -- has a declaration of a type to which one of the predefined operators
468 -- apply. The existence of this routine is an implementation artifact. A
469 -- more straightforward but more space-consuming choice would be to make
470 -- all inherited operators explicit in the symbol table.
472 procedure Inherit_Renamed_Profile (New_S : Entity_Id; Old_S : Entity_Id);
473 -- A subprogram defined by a renaming declaration inherits the parameter
474 -- profile of the renamed entity. The subtypes given in the subprogram
475 -- specification are discarded and replaced with those of the renamed
476 -- subprogram, which are then used to recheck the default values.
478 function Is_Appropriate_For_Record (T : Entity_Id) return Boolean;
479 -- Prefix is appropriate for record if it is of a record type, or an access
482 function Is_Appropriate_For_Entry_Prefix (T : Entity_Id) return Boolean;
483 -- True if it is of a task type, a protected type, or else an access to one
486 procedure Note_Redundant_Use (Clause : Node_Id);
487 -- Mark the name in a use clause as redundant if the corresponding entity
488 -- is already use-visible. Emit a warning if the use clause comes from
489 -- source and the proper warnings are enabled.
491 procedure Premature_Usage (N : Node_Id);
492 -- Diagnose usage of an entity before it is visible
494 procedure Use_One_Package (P : Entity_Id; N : Node_Id);
495 -- Make visible entities declared in package P potentially use-visible
496 -- in the current context. Also used in the analysis of subunits, when
497 -- re-installing use clauses of parent units. N is the use_clause that
498 -- names P (and possibly other packages).
500 procedure Use_One_Type (Id : Node_Id);
501 -- Id is the subtype mark from a use type clause. This procedure makes
502 -- the primitive operators of the type potentially use-visible.
504 procedure Write_Info;
505 -- Write debugging information on entities declared in current scope
507 procedure Write_Scopes;
508 pragma Warnings (Off, Write_Scopes);
509 -- Debugging information: dump all entities on scope stack
511 --------------------------------
512 -- Analyze_Exception_Renaming --
513 --------------------------------
515 -- The language only allows a single identifier, but the tree holds an
516 -- identifier list. The parser has already issued an error message if
517 -- there is more than one element in the list.
519 procedure Analyze_Exception_Renaming (N : Node_Id) is
520 Id : constant Node_Id := Defining_Identifier (N);
521 Nam : constant Node_Id := Name (N);
527 Set_Ekind (Id, E_Exception);
528 Set_Exception_Code (Id, Uint_0);
529 Set_Etype (Id, Standard_Exception_Type);
530 Set_Is_Pure (Id, Is_Pure (Current_Scope));
532 if not Is_Entity_Name (Nam) or else
533 Ekind (Entity (Nam)) /= E_Exception
535 Error_Msg_N ("invalid exception name in renaming", Nam);
537 if Present (Renamed_Object (Entity (Nam))) then
538 Set_Renamed_Object (Id, Renamed_Object (Entity (Nam)));
540 Set_Renamed_Object (Id, Entity (Nam));
543 end Analyze_Exception_Renaming;
545 ---------------------------
546 -- Analyze_Expanded_Name --
547 ---------------------------
549 procedure Analyze_Expanded_Name (N : Node_Id) is
551 -- If the entity pointer is already set, this is an internal node, or a
552 -- node that is analyzed more than once, after a tree modification. In
553 -- such a case there is no resolution to perform, just set the type. For
554 -- completeness, analyze prefix as well.
556 if Present (Entity (N)) then
557 if Is_Type (Entity (N)) then
558 Set_Etype (N, Entity (N));
560 Set_Etype (N, Etype (Entity (N)));
563 Analyze (Prefix (N));
566 Find_Expanded_Name (N);
568 end Analyze_Expanded_Name;
570 ---------------------------------------
571 -- Analyze_Generic_Function_Renaming --
572 ---------------------------------------
574 procedure Analyze_Generic_Function_Renaming (N : Node_Id) is
576 Analyze_Generic_Renaming (N, E_Generic_Function);
577 end Analyze_Generic_Function_Renaming;
579 --------------------------------------
580 -- Analyze_Generic_Package_Renaming --
581 --------------------------------------
583 procedure Analyze_Generic_Package_Renaming (N : Node_Id) is
585 -- Apply the Text_IO Kludge here, since we may be renaming one of the
586 -- subpackages of Text_IO, then join common routine.
588 Text_IO_Kludge (Name (N));
590 Analyze_Generic_Renaming (N, E_Generic_Package);
591 end Analyze_Generic_Package_Renaming;
593 ----------------------------------------
594 -- Analyze_Generic_Procedure_Renaming --
595 ----------------------------------------
597 procedure Analyze_Generic_Procedure_Renaming (N : Node_Id) is
599 Analyze_Generic_Renaming (N, E_Generic_Procedure);
600 end Analyze_Generic_Procedure_Renaming;
602 ------------------------------
603 -- Analyze_Generic_Renaming --
604 ------------------------------
606 procedure Analyze_Generic_Renaming
610 New_P : constant Entity_Id := Defining_Entity (N);
612 Inst : Boolean := False; -- prevent junk warning
615 if Name (N) = Error then
619 Generate_Definition (New_P);
621 if Current_Scope /= Standard_Standard then
622 Set_Is_Pure (New_P, Is_Pure (Current_Scope));
625 if Nkind (Name (N)) = N_Selected_Component then
626 Check_Generic_Child_Unit (Name (N), Inst);
631 if not Is_Entity_Name (Name (N)) then
632 Error_Msg_N ("expect entity name in renaming declaration", Name (N));
635 Old_P := Entity (Name (N));
639 Set_Ekind (New_P, K);
641 if Etype (Old_P) = Any_Type then
644 elsif Ekind (Old_P) /= K then
645 Error_Msg_N ("invalid generic unit name", Name (N));
648 if Present (Renamed_Object (Old_P)) then
649 Set_Renamed_Object (New_P, Renamed_Object (Old_P));
651 Set_Renamed_Object (New_P, Old_P);
654 Set_Is_Pure (New_P, Is_Pure (Old_P));
655 Set_Is_Preelaborated (New_P, Is_Preelaborated (Old_P));
657 Set_Etype (New_P, Etype (Old_P));
658 Set_Has_Completion (New_P);
660 if In_Open_Scopes (Old_P) then
661 Error_Msg_N ("within its scope, generic denotes its instance", N);
664 Check_Library_Unit_Renaming (N, Old_P);
666 end Analyze_Generic_Renaming;
668 -----------------------------
669 -- Analyze_Object_Renaming --
670 -----------------------------
672 procedure Analyze_Object_Renaming (N : Node_Id) is
673 Id : constant Entity_Id := Defining_Identifier (N);
675 Nam : constant Node_Id := Name (N);
679 function In_Generic_Scope (E : Entity_Id) return Boolean;
680 -- Determine whether entity E is inside a generic cope
682 ----------------------
683 -- In_Generic_Scope --
684 ----------------------
686 function In_Generic_Scope (E : Entity_Id) return Boolean is
691 while Present (S) and then S /= Standard_Standard loop
692 if Is_Generic_Unit (S) then
700 end In_Generic_Scope;
702 -- Start of processing for Analyze_Object_Renaming
709 Set_Is_Pure (Id, Is_Pure (Current_Scope));
712 -- The renaming of a component that depends on a discriminant requires
713 -- an actual subtype, because in subsequent use of the object Gigi will
714 -- be unable to locate the actual bounds. This explicit step is required
715 -- when the renaming is generated in removing side effects of an
716 -- already-analyzed expression.
718 if Nkind (Nam) = N_Selected_Component
719 and then Analyzed (Nam)
722 Dec := Build_Actual_Subtype_Of_Component (Etype (Nam), Nam);
724 if Present (Dec) then
725 Insert_Action (N, Dec);
726 T := Defining_Identifier (Dec);
730 -- Complete analysis of the subtype mark in any case, for ASIS use
732 if Present (Subtype_Mark (N)) then
733 Find_Type (Subtype_Mark (N));
736 elsif Present (Subtype_Mark (N)) then
737 Find_Type (Subtype_Mark (N));
738 T := Entity (Subtype_Mark (N));
741 if Nkind (Nam) = N_Type_Conversion
742 and then not Is_Tagged_Type (T)
745 ("renaming of conversion only allowed for tagged types", Nam);
750 -- Check that a class-wide object is not being renamed as an object
751 -- of a specific type. The test for access types is needed to exclude
752 -- cases where the renamed object is a dynamically tagged access
753 -- result, such as occurs in certain expansions.
755 if (Is_Class_Wide_Type (Etype (Nam))
756 or else (Is_Dynamically_Tagged (Nam)
757 and then not Is_Access_Type (T)))
758 and then not Is_Class_Wide_Type (T)
760 Error_Msg_N ("dynamically tagged expression not allowed!", Nam);
763 -- Ada 2005 (AI-230/AI-254): Access renaming
765 else pragma Assert (Present (Access_Definition (N)));
766 T := Access_Definition
768 N => Access_Definition (N));
770 Analyze_And_Resolve (Nam, T);
772 -- Ada 2005 (AI-231): "In the case where the type is defined by an
773 -- access_definition, the renamed entity shall be of an access-to-
774 -- constant type if and only if the access_definition defines an
775 -- access-to-constant type" ARM 8.5.1(4)
777 if Constant_Present (Access_Definition (N))
778 and then not Is_Access_Constant (Etype (Nam))
780 Error_Msg_N ("(Ada 2005): the renamed object is not "
781 & "access-to-constant (RM 8.5.1(6))", N);
785 -- Special processing for renaming function return object
787 if Nkind (Nam) = N_Function_Call
788 and then Comes_From_Source (Nam)
792 -- Usage is illegal in Ada 83
796 ("(Ada 83) cannot rename function return object", Nam);
798 -- In Ada 95, warn for odd case of renaming parameterless function
799 -- call if this is not a limited type (where this is useful)
802 if Warn_On_Object_Renames_Function
803 and then No (Parameter_Associations (Nam))
804 and then not Is_Limited_Type (Etype (Nam))
807 ("?renaming function result object is suspicious",
810 ("\?function & will be called only once",
811 Nam, Entity (Name (Nam)));
813 ("\?suggest using an initialized constant object instead",
819 -- An object renaming requires an exact match of the type. Class-wide
820 -- matching is not allowed.
822 if Is_Class_Wide_Type (T)
823 and then Base_Type (Etype (Nam)) /= Base_Type (T)
830 -- (Ada 2005: AI-326): Handle wrong use of incomplete type
832 if Nkind (Nam) = N_Explicit_Dereference
833 and then Ekind (Etype (T2)) = E_Incomplete_Type
835 Error_Msg_NE ("invalid use of incomplete type&", Id, T2);
837 elsif Ekind (Etype (T)) = E_Incomplete_Type then
838 Error_Msg_NE ("invalid use of incomplete type&", Id, T);
844 if Ada_Version >= Ada_05
845 and then Nkind (Nam) = N_Attribute_Reference
846 and then Attribute_Name (Nam) = Name_Priority
850 elsif Ada_Version >= Ada_05
851 and then Nkind (Nam) in N_Has_Entity
858 if Nkind (Nam) = N_Attribute_Reference then
859 Nam_Ent := Entity (Prefix (Nam));
861 Nam_Ent := Entity (Nam);
864 Nam_Decl := Parent (Nam_Ent);
866 if Has_Null_Exclusion (N)
867 and then not Has_Null_Exclusion (Nam_Decl)
869 -- Ada 2005 (AI-423): If the object name denotes a generic
870 -- formal object of a generic unit G, and the object renaming
871 -- declaration occurs within the body of G or within the body
872 -- of a generic unit declared within the declarative region
873 -- of G, then the declaration of the formal object of G must
874 -- have a null exclusion.
876 if Is_Formal_Object (Nam_Ent)
877 and then In_Generic_Scope (Id)
880 ("renamed formal does not exclude `NULL` "
881 & "(RM 8.5.1(4.6/2))", N);
883 -- Ada 2005 (AI-423): Otherwise, the subtype of the object name
884 -- shall exclude null.
886 elsif not Can_Never_Be_Null (Etype (Nam_Ent)) then
888 ("renamed object does not exclude `NULL` "
889 & "(RM 8.5.1(4.6/2))", N);
891 elsif Can_Never_Be_Null (Etype (Nam_Ent)) then
893 ("`NOT NULL` not allowed (type of& already excludes null)",
898 elsif Has_Null_Exclusion (N)
899 and then No (Access_Definition (N))
900 and then Can_Never_Be_Null (T)
903 ("`NOT NULL` not allowed (& already excludes null)", N, T);
908 Set_Ekind (Id, E_Variable);
909 Init_Size_Align (Id);
911 if T = Any_Type or else Etype (Nam) = Any_Type then
914 -- Verify that the renamed entity is an object or a function call. It
915 -- may have been rewritten in several ways.
917 elsif Is_Object_Reference (Nam) then
918 if Comes_From_Source (N)
919 and then Is_Dependent_Component_Of_Mutable_Object (Nam)
922 ("illegal renaming of discriminant-dependent component", Nam);
927 -- A static function call may have been folded into a literal
929 elsif Nkind (Original_Node (Nam)) = N_Function_Call
931 -- When expansion is disabled, attribute reference is not
932 -- rewritten as function call. Otherwise it may be rewritten
933 -- as a conversion, so check original node.
935 or else (Nkind (Original_Node (Nam)) = N_Attribute_Reference
936 and then Is_Function_Attribute_Name
937 (Attribute_Name (Original_Node (Nam))))
939 -- Weird but legal, equivalent to renaming a function call.
940 -- Illegal if the literal is the result of constant-folding an
941 -- attribute reference that is not a function.
943 or else (Is_Entity_Name (Nam)
944 and then Ekind (Entity (Nam)) = E_Enumeration_Literal
946 Nkind (Original_Node (Nam)) /= N_Attribute_Reference)
948 or else (Nkind (Nam) = N_Type_Conversion
949 and then Is_Tagged_Type (Entity (Subtype_Mark (Nam))))
953 elsif Nkind (Nam) = N_Type_Conversion then
955 ("renaming of conversion only allowed for tagged types", Nam);
959 elsif Ada_Version >= Ada_05
960 and then Nkind (Nam) = N_Attribute_Reference
961 and then Attribute_Name (Nam) = Name_Priority
965 -- Allow internally generated x'Reference expression
967 elsif Nkind (Nam) = N_Reference then
971 Error_Msg_N ("expect object name in renaming", Nam);
976 if not Is_Variable (Nam) then
977 Set_Ekind (Id, E_Constant);
978 Set_Never_Set_In_Source (Id, True);
979 Set_Is_True_Constant (Id, True);
982 Set_Renamed_Object (Id, Nam);
983 end Analyze_Object_Renaming;
985 ------------------------------
986 -- Analyze_Package_Renaming --
987 ------------------------------
989 procedure Analyze_Package_Renaming (N : Node_Id) is
990 New_P : constant Entity_Id := Defining_Entity (N);
995 if Name (N) = Error then
999 -- Apply Text_IO kludge here, since we may be renaming one of the
1000 -- children of Text_IO.
1002 Text_IO_Kludge (Name (N));
1004 if Current_Scope /= Standard_Standard then
1005 Set_Is_Pure (New_P, Is_Pure (Current_Scope));
1011 if Is_Entity_Name (Name (N)) then
1012 Old_P := Entity (Name (N));
1017 if Etype (Old_P) = Any_Type then
1019 ("expect package name in renaming", Name (N));
1021 elsif Ekind (Old_P) /= E_Package
1022 and then not (Ekind (Old_P) = E_Generic_Package
1023 and then In_Open_Scopes (Old_P))
1025 if Ekind (Old_P) = E_Generic_Package then
1027 ("generic package cannot be renamed as a package", Name (N));
1029 Error_Msg_Sloc := Sloc (Old_P);
1031 ("expect package name in renaming, found& declared#",
1035 -- Set basic attributes to minimize cascaded errors
1037 Set_Ekind (New_P, E_Package);
1038 Set_Etype (New_P, Standard_Void_Type);
1040 -- Here for OK package renaming
1043 -- Entities in the old package are accessible through the renaming
1044 -- entity. The simplest implementation is to have both packages share
1047 Set_Ekind (New_P, E_Package);
1048 Set_Etype (New_P, Standard_Void_Type);
1050 if Present (Renamed_Object (Old_P)) then
1051 Set_Renamed_Object (New_P, Renamed_Object (Old_P));
1053 Set_Renamed_Object (New_P, Old_P);
1056 Set_Has_Completion (New_P);
1058 Set_First_Entity (New_P, First_Entity (Old_P));
1059 Set_Last_Entity (New_P, Last_Entity (Old_P));
1060 Set_First_Private_Entity (New_P, First_Private_Entity (Old_P));
1061 Check_Library_Unit_Renaming (N, Old_P);
1062 Generate_Reference (Old_P, Name (N));
1064 -- If the renaming is in the visible part of a package, then we set
1065 -- Renamed_In_Spec for the renamed package, to prevent giving
1066 -- warnings about no entities referenced. Such a warning would be
1067 -- overenthusiastic, since clients can see entities in the renamed
1068 -- package via the visible package renaming.
1071 Ent : constant Entity_Id := Cunit_Entity (Current_Sem_Unit);
1073 if Ekind (Ent) = E_Package
1074 and then not In_Private_Part (Ent)
1075 and then In_Extended_Main_Source_Unit (N)
1076 and then Ekind (Old_P) = E_Package
1078 Set_Renamed_In_Spec (Old_P);
1082 -- If this is the renaming declaration of a package instantiation
1083 -- within itself, it is the declaration that ends the list of actuals
1084 -- for the instantiation. At this point, the subtypes that rename
1085 -- the actuals are flagged as generic, to avoid spurious ambiguities
1086 -- if the actuals for two distinct formals happen to coincide. If
1087 -- the actual is a private type, the subtype has a private completion
1088 -- that is flagged in the same fashion.
1090 -- Resolution is identical to what is was in the original generic.
1091 -- On exit from the generic instance, these are turned into regular
1092 -- subtypes again, so they are compatible with types in their class.
1094 if not Is_Generic_Instance (Old_P) then
1097 Spec := Specification (Unit_Declaration_Node (Old_P));
1100 if Nkind (Spec) = N_Package_Specification
1101 and then Present (Generic_Parent (Spec))
1102 and then Old_P = Current_Scope
1103 and then Chars (New_P) = Chars (Generic_Parent (Spec))
1109 E := First_Entity (Old_P);
1114 and then Nkind (Parent (E)) = N_Subtype_Declaration
1116 Set_Is_Generic_Actual_Type (E);
1118 if Is_Private_Type (E)
1119 and then Present (Full_View (E))
1121 Set_Is_Generic_Actual_Type (Full_View (E));
1130 end Analyze_Package_Renaming;
1132 -------------------------------
1133 -- Analyze_Renamed_Character --
1134 -------------------------------
1136 procedure Analyze_Renamed_Character
1141 C : constant Node_Id := Name (N);
1144 if Ekind (New_S) = E_Function then
1145 Resolve (C, Etype (New_S));
1148 Check_Frozen_Renaming (N, New_S);
1152 Error_Msg_N ("character literal can only be renamed as function", N);
1154 end Analyze_Renamed_Character;
1156 ---------------------------------
1157 -- Analyze_Renamed_Dereference --
1158 ---------------------------------
1160 procedure Analyze_Renamed_Dereference
1165 Nam : constant Node_Id := Name (N);
1166 P : constant Node_Id := Prefix (Nam);
1172 if not Is_Overloaded (P) then
1173 if Ekind (Etype (Nam)) /= E_Subprogram_Type
1174 or else not Type_Conformant (Etype (Nam), New_S) then
1175 Error_Msg_N ("designated type does not match specification", P);
1184 Get_First_Interp (Nam, Ind, It);
1186 while Present (It.Nam) loop
1188 if Ekind (It.Nam) = E_Subprogram_Type
1189 and then Type_Conformant (It.Nam, New_S) then
1191 if Typ /= Any_Id then
1192 Error_Msg_N ("ambiguous renaming", P);
1199 Get_Next_Interp (Ind, It);
1202 if Typ = Any_Type then
1203 Error_Msg_N ("designated type does not match specification", P);
1208 Check_Frozen_Renaming (N, New_S);
1212 end Analyze_Renamed_Dereference;
1214 ---------------------------
1215 -- Analyze_Renamed_Entry --
1216 ---------------------------
1218 procedure Analyze_Renamed_Entry
1223 Nam : constant Node_Id := Name (N);
1224 Sel : constant Node_Id := Selector_Name (Nam);
1228 if Entity (Sel) = Any_Id then
1230 -- Selector is undefined on prefix. Error emitted already
1232 Set_Has_Completion (New_S);
1236 -- Otherwise find renamed entity and build body of New_S as a call to it
1238 Old_S := Find_Renamed_Entity (N, Selector_Name (Nam), New_S);
1240 if Old_S = Any_Id then
1241 Error_Msg_N (" no subprogram or entry matches specification", N);
1244 Check_Subtype_Conformant (New_S, Old_S, N);
1245 Generate_Reference (New_S, Defining_Entity (N), 'b');
1246 Style.Check_Identifier (Defining_Entity (N), New_S);
1249 -- Only mode conformance required for a renaming_as_declaration
1251 Check_Mode_Conformant (New_S, Old_S, N);
1254 Inherit_Renamed_Profile (New_S, Old_S);
1256 -- The prefix can be an arbitrary expression that yields a task
1257 -- type, so it must be resolved.
1259 Resolve (Prefix (Nam), Scope (Old_S));
1262 Set_Convention (New_S, Convention (Old_S));
1263 Set_Has_Completion (New_S, Inside_A_Generic);
1266 Check_Frozen_Renaming (N, New_S);
1268 end Analyze_Renamed_Entry;
1270 -----------------------------------
1271 -- Analyze_Renamed_Family_Member --
1272 -----------------------------------
1274 procedure Analyze_Renamed_Family_Member
1279 Nam : constant Node_Id := Name (N);
1280 P : constant Node_Id := Prefix (Nam);
1284 if (Is_Entity_Name (P) and then Ekind (Entity (P)) = E_Entry_Family)
1285 or else (Nkind (P) = N_Selected_Component
1287 Ekind (Entity (Selector_Name (P))) = E_Entry_Family)
1289 if Is_Entity_Name (P) then
1290 Old_S := Entity (P);
1292 Old_S := Entity (Selector_Name (P));
1295 if not Entity_Matches_Spec (Old_S, New_S) then
1296 Error_Msg_N ("entry family does not match specification", N);
1299 Check_Subtype_Conformant (New_S, Old_S, N);
1300 Generate_Reference (New_S, Defining_Entity (N), 'b');
1301 Style.Check_Identifier (Defining_Entity (N), New_S);
1305 Error_Msg_N ("no entry family matches specification", N);
1308 Set_Has_Completion (New_S, Inside_A_Generic);
1311 Check_Frozen_Renaming (N, New_S);
1313 end Analyze_Renamed_Family_Member;
1315 -----------------------------------------
1316 -- Analyze_Renamed_Primitive_Operation --
1317 -----------------------------------------
1319 procedure Analyze_Renamed_Primitive_Operation
1328 Ctyp : Conformance_Type) return Boolean;
1329 -- Verify that the signatures of the renamed entity and the new entity
1330 -- match. The first formal of the renamed entity is skipped because it
1331 -- is the target object in any subsequent call.
1335 Ctyp : Conformance_Type) return Boolean
1341 if Ekind (Subp) /= Ekind (New_S) then
1345 Old_F := Next_Formal (First_Formal (Subp));
1346 New_F := First_Formal (New_S);
1347 while Present (Old_F) and then Present (New_F) loop
1348 if not Conforming_Types (Etype (Old_F), Etype (New_F), Ctyp) then
1352 if Ctyp >= Mode_Conformant
1353 and then Ekind (Old_F) /= Ekind (New_F)
1358 Next_Formal (New_F);
1359 Next_Formal (Old_F);
1366 if not Is_Overloaded (Selector_Name (Name (N))) then
1367 Old_S := Entity (Selector_Name (Name (N)));
1369 if not Conforms (Old_S, Type_Conformant) then
1374 -- Find the operation that matches the given signature
1382 Get_First_Interp (Selector_Name (Name (N)), Ind, It);
1384 while Present (It.Nam) loop
1385 if Conforms (It.Nam, Type_Conformant) then
1389 Get_Next_Interp (Ind, It);
1394 if Old_S = Any_Id then
1395 Error_Msg_N (" no subprogram or entry matches specification", N);
1399 if not Conforms (Old_S, Subtype_Conformant) then
1400 Error_Msg_N ("subtype conformance error in renaming", N);
1403 Generate_Reference (New_S, Defining_Entity (N), 'b');
1404 Style.Check_Identifier (Defining_Entity (N), New_S);
1407 -- Only mode conformance required for a renaming_as_declaration
1409 if not Conforms (Old_S, Mode_Conformant) then
1410 Error_Msg_N ("mode conformance error in renaming", N);
1414 -- Inherit_Renamed_Profile (New_S, Old_S);
1416 -- The prefix can be an arbitrary expression that yields an
1417 -- object, so it must be resolved.
1419 Resolve (Prefix (Name (N)));
1421 end Analyze_Renamed_Primitive_Operation;
1423 ---------------------------------
1424 -- Analyze_Subprogram_Renaming --
1425 ---------------------------------
1427 procedure Analyze_Subprogram_Renaming (N : Node_Id) is
1428 Formal_Spec : constant Node_Id := Corresponding_Formal_Spec (N);
1429 Is_Actual : constant Boolean := Present (Formal_Spec);
1430 Inst_Node : Node_Id := Empty;
1431 Nam : constant Node_Id := Name (N);
1433 Old_S : Entity_Id := Empty;
1434 Rename_Spec : Entity_Id;
1435 Save_AV : constant Ada_Version_Type := Ada_Version;
1436 Save_AV_Exp : constant Ada_Version_Type := Ada_Version_Explicit;
1437 Spec : constant Node_Id := Specification (N);
1439 procedure Check_Null_Exclusion
1442 -- Ada 2005 (AI-423): Given renaming Ren of subprogram Sub, check the
1443 -- following AI rules:
1445 -- If Ren is a renaming of a formal subprogram and one of its
1446 -- parameters has a null exclusion, then the corresponding formal
1447 -- in Sub must also have one. Otherwise the subtype of the Sub's
1448 -- formal parameter must exclude null.
1450 -- If Ren is a renaming of a formal function and its return
1451 -- profile has a null exclusion, then Sub's return profile must
1452 -- have one. Otherwise the subtype of Sub's return profile must
1455 function Original_Subprogram (Subp : Entity_Id) return Entity_Id;
1456 -- Find renamed entity when the declaration is a renaming_as_body and
1457 -- the renamed entity may itself be a renaming_as_body. Used to enforce
1458 -- rule that a renaming_as_body is illegal if the declaration occurs
1459 -- before the subprogram it completes is frozen, and renaming indirectly
1460 -- renames the subprogram itself.(Defect Report 8652/0027).
1462 --------------------------
1463 -- Check_Null_Exclusion --
1464 --------------------------
1466 procedure Check_Null_Exclusion
1470 Ren_Formal : Entity_Id;
1471 Sub_Formal : Entity_Id;
1476 Ren_Formal := First_Formal (Ren);
1477 Sub_Formal := First_Formal (Sub);
1478 while Present (Ren_Formal)
1479 and then Present (Sub_Formal)
1481 if Has_Null_Exclusion (Parent (Ren_Formal))
1483 not (Has_Null_Exclusion (Parent (Sub_Formal))
1484 or else Can_Never_Be_Null (Etype (Sub_Formal)))
1487 ("`NOT NULL` required for parameter &",
1488 Parent (Sub_Formal), Sub_Formal);
1491 Next_Formal (Ren_Formal);
1492 Next_Formal (Sub_Formal);
1495 -- Return profile check
1497 if Nkind (Parent (Ren)) = N_Function_Specification
1498 and then Nkind (Parent (Sub)) = N_Function_Specification
1499 and then Has_Null_Exclusion (Parent (Ren))
1501 not (Has_Null_Exclusion (Parent (Sub))
1502 or else Can_Never_Be_Null (Etype (Sub)))
1505 ("return must specify `NOT NULL`",
1506 Result_Definition (Parent (Sub)));
1508 end Check_Null_Exclusion;
1510 -------------------------
1511 -- Original_Subprogram --
1512 -------------------------
1514 function Original_Subprogram (Subp : Entity_Id) return Entity_Id is
1515 Orig_Decl : Node_Id;
1516 Orig_Subp : Entity_Id;
1519 -- First case: renamed entity is itself a renaming
1521 if Present (Alias (Subp)) then
1522 return Alias (Subp);
1525 Nkind (Unit_Declaration_Node (Subp)) = N_Subprogram_Declaration
1527 (Corresponding_Body (Unit_Declaration_Node (Subp)))
1529 -- Check if renamed entity is a renaming_as_body
1532 Unit_Declaration_Node
1533 (Corresponding_Body (Unit_Declaration_Node (Subp)));
1535 if Nkind (Orig_Decl) = N_Subprogram_Renaming_Declaration then
1536 Orig_Subp := Entity (Name (Orig_Decl));
1538 if Orig_Subp = Rename_Spec then
1540 -- Circularity detected
1545 return (Original_Subprogram (Orig_Subp));
1553 end Original_Subprogram;
1555 -- Start of processing for Analyze_Subprogram_Renaming
1558 -- We must test for the attribute renaming case before the Analyze
1559 -- call because otherwise Sem_Attr will complain that the attribute
1560 -- is missing an argument when it is analyzed.
1562 if Nkind (Nam) = N_Attribute_Reference then
1564 -- In the case of an abstract formal subprogram association, rewrite
1565 -- an actual given by a stream attribute as the name of the
1566 -- corresponding stream primitive of the type.
1568 -- In a generic context the stream operations are not generated, and
1569 -- this must be treated as a normal attribute reference, to be
1570 -- expanded in subsequent instantiations.
1572 if Is_Actual and then Is_Abstract_Subprogram (Formal_Spec)
1573 and then Expander_Active
1576 Stream_Prim : Entity_Id;
1577 Prefix_Type : constant Entity_Id := Entity (Prefix (Nam));
1580 -- The class-wide forms of the stream attributes are not
1581 -- primitive dispatching operations (even though they
1582 -- internally dispatch to a stream attribute).
1584 if Is_Class_Wide_Type (Prefix_Type) then
1586 ("attribute must be a primitive dispatching operation",
1591 -- Retrieve the primitive subprogram associated with the
1592 -- attribute. This can only be a stream attribute, since those
1593 -- are the only ones that are dispatching (and the actual for
1594 -- an abstract formal subprogram must be dispatching
1598 case Attribute_Name (Nam) is
1601 Find_Prim_Op (Prefix_Type, TSS_Stream_Input);
1604 Find_Prim_Op (Prefix_Type, TSS_Stream_Output);
1607 Find_Prim_Op (Prefix_Type, TSS_Stream_Read);
1610 Find_Prim_Op (Prefix_Type, TSS_Stream_Write);
1613 ("attribute must be a primitive"
1614 & " dispatching operation", Nam);
1620 -- If no operation was found, and the type is limited,
1621 -- the user should have defined one.
1623 when Program_Error =>
1624 if Is_Limited_Type (Prefix_Type) then
1626 ("stream operation not defined for type&",
1630 -- Otherwise, compiler should have generated default
1637 -- Rewrite the attribute into the name of its corresponding
1638 -- primitive dispatching subprogram. We can then proceed with
1639 -- the usual processing for subprogram renamings.
1642 Prim_Name : constant Node_Id :=
1643 Make_Identifier (Sloc (Nam),
1644 Chars => Chars (Stream_Prim));
1646 Set_Entity (Prim_Name, Stream_Prim);
1647 Rewrite (Nam, Prim_Name);
1652 -- Normal processing for a renaming of an attribute
1655 Attribute_Renaming (N);
1660 -- Check whether this declaration corresponds to the instantiation
1661 -- of a formal subprogram.
1663 -- If this is an instantiation, the corresponding actual is frozen and
1664 -- error messages can be made more precise. If this is a default
1665 -- subprogram, the entity is already established in the generic, and is
1666 -- not retrieved by visibility. If it is a default with a box, the
1667 -- candidate interpretations, if any, have been collected when building
1668 -- the renaming declaration. If overloaded, the proper interpretation is
1669 -- determined in Find_Renamed_Entity. If the entity is an operator,
1670 -- Find_Renamed_Entity applies additional visibility checks.
1673 Inst_Node := Unit_Declaration_Node (Formal_Spec);
1675 if Is_Entity_Name (Nam)
1676 and then Present (Entity (Nam))
1677 and then not Comes_From_Source (Nam)
1678 and then not Is_Overloaded (Nam)
1680 Old_S := Entity (Nam);
1681 New_S := Analyze_Subprogram_Specification (Spec);
1685 if Ekind (Entity (Nam)) = E_Operator then
1689 if Box_Present (Inst_Node) then
1690 Old_S := Find_Renamed_Entity (N, Name (N), New_S, Is_Actual);
1692 -- If there is an immediately visible homonym of the operator
1693 -- and the declaration has a default, this is worth a warning
1694 -- because the user probably did not intend to get the pre-
1695 -- defined operator, visible in the generic declaration. To
1696 -- find if there is an intended candidate, analyze the renaming
1697 -- again in the current context.
1699 elsif Scope (Old_S) = Standard_Standard
1700 and then Present (Default_Name (Inst_Node))
1703 Decl : constant Node_Id := New_Copy_Tree (N);
1707 Set_Entity (Name (Decl), Empty);
1708 Analyze (Name (Decl));
1710 Find_Renamed_Entity (Decl, Name (Decl), New_S, True);
1713 and then In_Open_Scopes (Scope (Hidden))
1714 and then Is_Immediately_Visible (Hidden)
1715 and then Comes_From_Source (Hidden)
1716 and then Hidden /= Old_S
1718 Error_Msg_Sloc := Sloc (Hidden);
1719 Error_Msg_N ("?default subprogram is resolved " &
1720 "in the generic declaration " &
1721 "(RM 12.6(17))", N);
1722 Error_Msg_NE ("\?and will not use & #", N, Hidden);
1730 New_S := Analyze_Subprogram_Specification (Spec);
1734 -- Renamed entity must be analyzed first, to avoid being hidden by
1735 -- new name (which might be the same in a generic instance).
1739 -- The renaming defines a new overloaded entity, which is analyzed
1740 -- like a subprogram declaration.
1742 New_S := Analyze_Subprogram_Specification (Spec);
1745 if Current_Scope /= Standard_Standard then
1746 Set_Is_Pure (New_S, Is_Pure (Current_Scope));
1749 Rename_Spec := Find_Corresponding_Spec (N);
1751 -- Case of Renaming_As_Body
1753 if Present (Rename_Spec) then
1755 -- Renaming declaration is the completion of the declaration of
1756 -- Rename_Spec. We build an actual body for it at the freezing point.
1758 Set_Corresponding_Spec (N, Rename_Spec);
1760 -- Deal with special case of stream functions of abstract types
1763 if Nkind (Unit_Declaration_Node (Rename_Spec)) =
1764 N_Abstract_Subprogram_Declaration
1766 -- Input stream functions are abstract if the object type is
1767 -- abstract. Similarly, all default stream functions for an
1768 -- interface type are abstract. However, these subprograms may
1769 -- receive explicit declarations in representation clauses, making
1770 -- the attribute subprograms usable as defaults in subsequent
1772 -- In this case we rewrite the declaration to make the subprogram
1773 -- non-abstract. We remove the previous declaration, and insert
1774 -- the new one at the point of the renaming, to prevent premature
1775 -- access to unfrozen types. The new declaration reuses the
1776 -- specification of the previous one, and must not be analyzed.
1779 (Is_Primitive (Entity (Nam))
1781 Is_Abstract_Type (Find_Dispatching_Type (Entity (Nam))));
1783 Old_Decl : constant Node_Id :=
1784 Unit_Declaration_Node (Rename_Spec);
1785 New_Decl : constant Node_Id :=
1786 Make_Subprogram_Declaration (Sloc (N),
1788 Relocate_Node (Specification (Old_Decl)));
1791 Insert_After (N, New_Decl);
1792 Set_Is_Abstract_Subprogram (Rename_Spec, False);
1793 Set_Analyzed (New_Decl);
1797 Set_Corresponding_Body (Unit_Declaration_Node (Rename_Spec), New_S);
1799 if Ada_Version = Ada_83 and then Comes_From_Source (N) then
1800 Error_Msg_N ("(Ada 83) renaming cannot serve as a body", N);
1803 Set_Convention (New_S, Convention (Rename_Spec));
1804 Check_Fully_Conformant (New_S, Rename_Spec);
1805 Set_Public_Status (New_S);
1807 -- The specification does not introduce new formals, but only
1808 -- repeats the formals of the original subprogram declaration.
1809 -- For cross-reference purposes, and for refactoring tools, we
1810 -- treat the formals of the renaming declaration as body formals.
1812 Reference_Body_Formals (Rename_Spec, New_S);
1814 -- Indicate that the entity in the declaration functions like the
1815 -- corresponding body, and is not a new entity. The body will be
1816 -- constructed later at the freeze point, so indicate that the
1817 -- completion has not been seen yet.
1819 Set_Ekind (New_S, E_Subprogram_Body);
1820 New_S := Rename_Spec;
1821 Set_Has_Completion (Rename_Spec, False);
1823 -- Ada 2005: check overriding indicator
1825 if Is_Overriding_Operation (Rename_Spec) then
1826 if Must_Not_Override (Specification (N)) then
1828 ("subprogram& overrides inherited operation",
1831 Style_Check and then not Must_Override (Specification (N))
1833 Style.Missing_Overriding (N, Rename_Spec);
1836 elsif Must_Override (Specification (N)) then
1837 Error_Msg_NE ("subprogram& is not overriding", N, Rename_Spec);
1840 -- Normal subprogram renaming (not renaming as body)
1843 Generate_Definition (New_S);
1844 New_Overloaded_Entity (New_S);
1846 if Is_Entity_Name (Nam)
1847 and then Is_Intrinsic_Subprogram (Entity (Nam))
1851 Check_Delayed_Subprogram (New_S);
1855 -- There is no need for elaboration checks on the new entity, which may
1856 -- be called before the next freezing point where the body will appear.
1857 -- Elaboration checks refer to the real entity, not the one created by
1858 -- the renaming declaration.
1860 Set_Kill_Elaboration_Checks (New_S, True);
1862 if Etype (Nam) = Any_Type then
1863 Set_Has_Completion (New_S);
1866 elsif Nkind (Nam) = N_Selected_Component then
1868 -- A prefix of the form A.B can designate an entry of task A, a
1869 -- protected operation of protected object A, or finally a primitive
1870 -- operation of object A. In the later case, A is an object of some
1871 -- tagged type, or an access type that denotes one such. To further
1872 -- distinguish these cases, note that the scope of a task entry or
1873 -- protected operation is type of the prefix.
1875 -- The prefix could be an overloaded function call that returns both
1876 -- kinds of operations. This overloading pathology is left to the
1877 -- dedicated reader ???
1880 T : constant Entity_Id := Etype (Prefix (Nam));
1889 Is_Tagged_Type (Designated_Type (T))))
1890 and then Scope (Entity (Selector_Name (Nam))) /= T
1892 Analyze_Renamed_Primitive_Operation
1893 (N, New_S, Present (Rename_Spec));
1897 -- Renamed entity is an entry or protected operation. For those
1898 -- cases an explicit body is built (at the point of freezing of
1899 -- this entity) that contains a call to the renamed entity.
1901 -- This is not allowed for renaming as body if the renamed
1902 -- spec is already frozen (see RM 8.5.4(5) for details).
1904 if Present (Rename_Spec)
1905 and then Is_Frozen (Rename_Spec)
1908 ("renaming-as-body cannot rename entry as subprogram", N);
1910 ("\since & is already frozen (RM 8.5.4(5))",
1913 Analyze_Renamed_Entry (N, New_S, Present (Rename_Spec));
1920 elsif Nkind (Nam) = N_Explicit_Dereference then
1922 -- Renamed entity is designated by access_to_subprogram expression.
1923 -- Must build body to encapsulate call, as in the entry case.
1925 Analyze_Renamed_Dereference (N, New_S, Present (Rename_Spec));
1928 elsif Nkind (Nam) = N_Indexed_Component then
1929 Analyze_Renamed_Family_Member (N, New_S, Present (Rename_Spec));
1932 elsif Nkind (Nam) = N_Character_Literal then
1933 Analyze_Renamed_Character (N, New_S, Present (Rename_Spec));
1936 elsif (not Is_Entity_Name (Nam)
1937 and then Nkind (Nam) /= N_Operator_Symbol)
1938 or else not Is_Overloadable (Entity (Nam))
1940 Error_Msg_N ("expect valid subprogram name in renaming", N);
1944 -- Find the renamed entity that matches the given specification. Disable
1945 -- Ada_83 because there is no requirement of full conformance between
1946 -- renamed entity and new entity, even though the same circuit is used.
1948 -- This is a bit of a kludge, which introduces a really irregular use of
1949 -- Ada_Version[_Explicit]. Would be nice to find cleaner way to do this
1952 Ada_Version := Ada_Version_Type'Max (Ada_Version, Ada_95);
1953 Ada_Version_Explicit := Ada_Version;
1956 Old_S := Find_Renamed_Entity (N, Name (N), New_S, Is_Actual);
1958 -- When the renamed subprogram is overloaded and used as an actual
1959 -- of a generic, its entity is set to the first available homonym.
1960 -- We must first disambiguate the name, then set the proper entity.
1963 and then Is_Overloaded (Nam)
1965 Set_Entity (Nam, Old_S);
1969 -- Most common case: subprogram renames subprogram. No body is generated
1970 -- in this case, so we must indicate the declaration is complete as is.
1971 -- and inherit various attributes of the renamed subprogram.
1973 if No (Rename_Spec) then
1974 Set_Has_Completion (New_S);
1975 Set_Is_Imported (New_S, Is_Imported (Entity (Nam)));
1976 Set_Is_Pure (New_S, Is_Pure (Entity (Nam)));
1977 Set_Is_Preelaborated (New_S, Is_Preelaborated (Entity (Nam)));
1979 -- Ada 2005 (AI-423): Check the consistency of null exclusions
1980 -- between a subprogram and its correct renaming.
1982 -- Note: the Any_Id check is a guard that prevents compiler crashes
1983 -- when performing a null exclusion check between a renaming and a
1984 -- renamed subprogram that has been found to be illegal.
1986 if Ada_Version >= Ada_05
1987 and then Entity (Nam) /= Any_Id
1989 Check_Null_Exclusion
1991 Sub => Entity (Nam));
1994 -- Enforce the Ada 2005 rule that the renamed entity cannot require
1995 -- overriding. The flag Requires_Overriding is set very selectively
1996 -- and misses some other illegal cases. The additional conditions
1997 -- checked below are sufficient but not necessary ???
1999 -- The rule does not apply to the renaming generated for an actual
2000 -- subprogram in an instance.
2005 -- Guard against previous errors, and omit renamings of predefined
2008 elsif Ekind (Old_S) /= E_Function
2009 and then Ekind (Old_S) /= E_Procedure
2013 elsif Requires_Overriding (Old_S)
2015 (Is_Abstract_Subprogram (Old_S)
2016 and then Present (Find_Dispatching_Type (Old_S))
2018 not Is_Abstract_Type (Find_Dispatching_Type (Old_S)))
2021 ("renamed entity cannot be "
2022 & "subprogram that requires overriding (RM 8.5.4 (5.1))", N);
2026 if Old_S /= Any_Id then
2028 and then From_Default (N)
2030 -- This is an implicit reference to the default actual
2032 Generate_Reference (Old_S, Nam, Typ => 'i', Force => True);
2034 Generate_Reference (Old_S, Nam);
2037 -- For a renaming-as-body, require subtype conformance, but if the
2038 -- declaration being completed has not been frozen, then inherit the
2039 -- convention of the renamed subprogram prior to checking conformance
2040 -- (unless the renaming has an explicit convention established; the
2041 -- rule stated in the RM doesn't seem to address this ???).
2043 if Present (Rename_Spec) then
2044 Generate_Reference (Rename_Spec, Defining_Entity (Spec), 'b');
2045 Style.Check_Identifier (Defining_Entity (Spec), Rename_Spec);
2047 if not Is_Frozen (Rename_Spec) then
2048 if not Has_Convention_Pragma (Rename_Spec) then
2049 Set_Convention (New_S, Convention (Old_S));
2052 if Ekind (Old_S) /= E_Operator then
2053 Check_Mode_Conformant (New_S, Old_S, Spec);
2056 if Original_Subprogram (Old_S) = Rename_Spec then
2057 Error_Msg_N ("unfrozen subprogram cannot rename itself ", N);
2060 Check_Subtype_Conformant (New_S, Old_S, Spec);
2063 Check_Frozen_Renaming (N, Rename_Spec);
2065 -- Check explicitly that renamed entity is not intrinsic, because
2066 -- in in a generic the renamed body is not built. In this case,
2067 -- the renaming_as_body is a completion.
2069 if Inside_A_Generic then
2070 if Is_Frozen (Rename_Spec)
2071 and then Is_Intrinsic_Subprogram (Old_S)
2074 ("subprogram in renaming_as_body cannot be intrinsic",
2078 Set_Has_Completion (Rename_Spec);
2081 elsif Ekind (Old_S) /= E_Operator then
2082 Check_Mode_Conformant (New_S, Old_S);
2085 and then Error_Posted (New_S)
2087 Error_Msg_NE ("invalid actual subprogram: & #!", N, Old_S);
2091 if No (Rename_Spec) then
2093 -- The parameter profile of the new entity is that of the renamed
2094 -- entity: the subtypes given in the specification are irrelevant.
2096 Inherit_Renamed_Profile (New_S, Old_S);
2098 -- A call to the subprogram is transformed into a call to the
2099 -- renamed entity. This is transitive if the renamed entity is
2100 -- itself a renaming.
2102 if Present (Alias (Old_S)) then
2103 Set_Alias (New_S, Alias (Old_S));
2105 Set_Alias (New_S, Old_S);
2108 -- Note that we do not set Is_Intrinsic_Subprogram if we have a
2109 -- renaming as body, since the entity in this case is not an
2110 -- intrinsic (it calls an intrinsic, but we have a real body for
2111 -- this call, and it is in this body that the required intrinsic
2112 -- processing will take place).
2114 -- Also, if this is a renaming of inequality, the renamed operator
2115 -- is intrinsic, but what matters is the corresponding equality
2116 -- operator, which may be user-defined.
2118 Set_Is_Intrinsic_Subprogram
2120 Is_Intrinsic_Subprogram (Old_S)
2122 (Chars (Old_S) /= Name_Op_Ne
2123 or else Ekind (Old_S) = E_Operator
2125 Is_Intrinsic_Subprogram
2126 (Corresponding_Equality (Old_S))));
2128 if Ekind (Alias (New_S)) = E_Operator then
2129 Set_Has_Delayed_Freeze (New_S, False);
2132 -- If the renaming corresponds to an association for an abstract
2133 -- formal subprogram, then various attributes must be set to
2134 -- indicate that the renaming is an abstract dispatching operation
2135 -- with a controlling type.
2137 if Is_Actual and then Is_Abstract_Subprogram (Formal_Spec) then
2139 -- Mark the renaming as abstract here, so Find_Dispatching_Type
2140 -- see it as corresponding to a generic association for a
2141 -- formal abstract subprogram
2143 Set_Is_Abstract_Subprogram (New_S);
2146 New_S_Ctrl_Type : constant Entity_Id :=
2147 Find_Dispatching_Type (New_S);
2148 Old_S_Ctrl_Type : constant Entity_Id :=
2149 Find_Dispatching_Type (Old_S);
2152 if Old_S_Ctrl_Type /= New_S_Ctrl_Type then
2154 ("actual must be dispatching subprogram for type&",
2155 Nam, New_S_Ctrl_Type);
2158 Set_Is_Dispatching_Operation (New_S);
2159 Check_Controlling_Formals (New_S_Ctrl_Type, New_S);
2161 -- If the actual in the formal subprogram is itself a
2162 -- formal abstract subprogram association, there's no
2163 -- dispatch table component or position to inherit.
2165 if Present (DTC_Entity (Old_S)) then
2166 Set_DTC_Entity (New_S, DTC_Entity (Old_S));
2167 Set_DT_Position (New_S, DT_Position (Old_S));
2175 and then (Old_S = New_S
2176 or else (Nkind (Nam) /= N_Expanded_Name
2177 and then Chars (Old_S) = Chars (New_S)))
2179 Error_Msg_N ("subprogram cannot rename itself", N);
2182 Set_Convention (New_S, Convention (Old_S));
2184 if Is_Abstract_Subprogram (Old_S) then
2185 if Present (Rename_Spec) then
2187 ("a renaming-as-body cannot rename an abstract subprogram",
2189 Set_Has_Completion (Rename_Spec);
2191 Set_Is_Abstract_Subprogram (New_S);
2195 Check_Library_Unit_Renaming (N, Old_S);
2197 -- Pathological case: procedure renames entry in the scope of its
2198 -- task. Entry is given by simple name, but body must be built for
2199 -- procedure. Of course if called it will deadlock.
2201 if Ekind (Old_S) = E_Entry then
2202 Set_Has_Completion (New_S, False);
2203 Set_Alias (New_S, Empty);
2207 Freeze_Before (N, Old_S);
2208 Set_Has_Delayed_Freeze (New_S, False);
2209 Freeze_Before (N, New_S);
2211 -- An abstract subprogram is only allowed as an actual in the case
2212 -- where the formal subprogram is also abstract.
2214 if (Ekind (Old_S) = E_Procedure or else Ekind (Old_S) = E_Function)
2215 and then Is_Abstract_Subprogram (Old_S)
2216 and then not Is_Abstract_Subprogram (Formal_Spec)
2219 ("abstract subprogram not allowed as generic actual", Nam);
2224 -- A common error is to assume that implicit operators for types are
2225 -- defined in Standard, or in the scope of a subtype. In those cases
2226 -- where the renamed entity is given with an expanded name, it is
2227 -- worth mentioning that operators for the type are not declared in
2228 -- the scope given by the prefix.
2230 if Nkind (Nam) = N_Expanded_Name
2231 and then Nkind (Selector_Name (Nam)) = N_Operator_Symbol
2232 and then Scope (Entity (Nam)) = Standard_Standard
2235 T : constant Entity_Id :=
2236 Base_Type (Etype (First_Formal (New_S)));
2238 Error_Msg_Node_2 := Prefix (Nam);
2240 ("operator for type& is not declared in&", Prefix (Nam), T);
2245 ("no visible subprogram matches the specification for&",
2249 if Present (Candidate_Renaming) then
2255 F1 := First_Formal (Candidate_Renaming);
2256 F2 := First_Formal (New_S);
2258 while Present (F1) and then Present (F2) loop
2263 if Present (F1) and then Present (Default_Value (F1)) then
2264 if Present (Next_Formal (F1)) then
2266 ("\missing specification for &" &
2267 " and other formals with defaults", Spec, F1);
2270 ("\missing specification for &", Spec, F1);
2277 -- Ada 2005 AI 404: if the new subprogram is dispatching, verify that
2278 -- controlling access parameters are known non-null for the renamed
2279 -- subprogram. Test also applies to a subprogram instantiation that
2280 -- is dispatching. Test is skipped if some previous error was detected
2281 -- that set Old_S to Any_Id.
2283 if Ada_Version >= Ada_05
2284 and then Old_S /= Any_Id
2285 and then not Is_Dispatching_Operation (Old_S)
2286 and then Is_Dispatching_Operation (New_S)
2293 Old_F := First_Formal (Old_S);
2294 New_F := First_Formal (New_S);
2295 while Present (Old_F) loop
2296 if Ekind (Etype (Old_F)) = E_Anonymous_Access_Type
2297 and then Is_Controlling_Formal (New_F)
2298 and then not Can_Never_Be_Null (Old_F)
2300 Error_Msg_N ("access parameter is controlling,", New_F);
2302 ("\corresponding parameter of& "
2303 & "must be explicitly null excluding", New_F, Old_S);
2306 Next_Formal (Old_F);
2307 Next_Formal (New_F);
2312 -- A useful warning, suggested by Ada Bug Finder (Ada-Europe 2005)
2314 if Comes_From_Source (N)
2315 and then Present (Old_S)
2316 and then Nkind (Old_S) = N_Defining_Operator_Symbol
2317 and then Nkind (New_S) = N_Defining_Operator_Symbol
2318 and then Chars (Old_S) /= Chars (New_S)
2321 ("?& is being renamed as a different operator",
2325 -- Another warning or some utility: if the new subprogram as the same
2326 -- name as the old one, the old one is not hidden by an outer homograph,
2327 -- the new one is not a public symbol, and the old one is otherwise
2328 -- directly visible, the renaming is superfluous.
2330 if Chars (Old_S) = Chars (New_S)
2331 and then Comes_From_Source (N)
2332 and then Scope (Old_S) /= Standard_Standard
2333 and then Warn_On_Redundant_Constructs
2335 (Is_Immediately_Visible (Old_S)
2336 or else Is_Potentially_Use_Visible (Old_S))
2337 and then Is_Overloadable (Current_Scope)
2338 and then Chars (Current_Scope) /= Chars (Old_S)
2341 ("?redundant renaming, entity is directly visible", Name (N));
2344 Ada_Version := Save_AV;
2345 Ada_Version_Explicit := Save_AV_Exp;
2346 end Analyze_Subprogram_Renaming;
2348 -------------------------
2349 -- Analyze_Use_Package --
2350 -------------------------
2352 -- Resolve the package names in the use clause, and make all the visible
2353 -- entities defined in the package potentially use-visible. If the package
2354 -- is already in use from a previous use clause, its visible entities are
2355 -- already use-visible. In that case, mark the occurrence as a redundant
2356 -- use. If the package is an open scope, i.e. if the use clause occurs
2357 -- within the package itself, ignore it.
2359 procedure Analyze_Use_Package (N : Node_Id) is
2360 Pack_Name : Node_Id;
2363 -- Start of processing for Analyze_Use_Package
2366 Set_Hidden_By_Use_Clause (N, No_Elist);
2368 -- Use clause is not allowed in a spec of a predefined package
2369 -- declaration except that packages whose file name starts a-n are OK
2370 -- (these are children of Ada.Numerics, and such packages are never
2371 -- loaded by Rtsfind).
2373 if Is_Predefined_File_Name (Unit_File_Name (Current_Sem_Unit))
2374 and then Name_Buffer (1 .. 3) /= "a-n"
2376 Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Declaration
2378 Error_Msg_N ("use clause not allowed in predefined spec", N);
2381 -- Chain clause to list of use clauses in current scope
2383 if Nkind (Parent (N)) /= N_Compilation_Unit then
2384 Chain_Use_Clause (N);
2387 -- Loop through package names to identify referenced packages
2389 Pack_Name := First (Names (N));
2390 while Present (Pack_Name) loop
2391 Analyze (Pack_Name);
2393 if Nkind (Parent (N)) = N_Compilation_Unit
2394 and then Nkind (Pack_Name) = N_Expanded_Name
2400 Pref := Prefix (Pack_Name);
2401 while Nkind (Pref) = N_Expanded_Name loop
2402 Pref := Prefix (Pref);
2405 if Entity (Pref) = Standard_Standard then
2407 ("predefined package Standard cannot appear"
2408 & " in a context clause", Pref);
2416 -- Loop through package names to mark all entities as potentially
2419 Pack_Name := First (Names (N));
2420 while Present (Pack_Name) loop
2421 if Is_Entity_Name (Pack_Name) then
2422 Pack := Entity (Pack_Name);
2424 if Ekind (Pack) /= E_Package
2425 and then Etype (Pack) /= Any_Type
2427 if Ekind (Pack) = E_Generic_Package then
2429 ("a generic package is not allowed in a use clause",
2432 Error_Msg_N ("& is not a usable package", Pack_Name);
2436 if Nkind (Parent (N)) = N_Compilation_Unit then
2437 Check_In_Previous_With_Clause (N, Pack_Name);
2440 if Applicable_Use (Pack_Name) then
2441 Use_One_Package (Pack, N);
2445 -- Report error because name denotes something other than a package
2448 Error_Msg_N ("& is not a package", Pack_Name);
2453 end Analyze_Use_Package;
2455 ----------------------
2456 -- Analyze_Use_Type --
2457 ----------------------
2459 procedure Analyze_Use_Type (N : Node_Id) is
2464 Set_Hidden_By_Use_Clause (N, No_Elist);
2466 -- Chain clause to list of use clauses in current scope
2468 if Nkind (Parent (N)) /= N_Compilation_Unit then
2469 Chain_Use_Clause (N);
2472 Id := First (Subtype_Marks (N));
2473 while Present (Id) loop
2477 if E /= Any_Type then
2480 if Nkind (Parent (N)) = N_Compilation_Unit then
2481 if Nkind (Id) = N_Identifier then
2482 Error_Msg_N ("type is not directly visible", Id);
2484 elsif Is_Child_Unit (Scope (E))
2485 and then Scope (E) /= System_Aux_Id
2487 Check_In_Previous_With_Clause (N, Prefix (Id));
2494 end Analyze_Use_Type;
2496 --------------------
2497 -- Applicable_Use --
2498 --------------------
2500 function Applicable_Use (Pack_Name : Node_Id) return Boolean is
2501 Pack : constant Entity_Id := Entity (Pack_Name);
2504 if In_Open_Scopes (Pack) then
2505 if Warn_On_Redundant_Constructs
2506 and then Pack = Current_Scope
2509 ("& is already use-visible within itself?", Pack_Name, Pack);
2514 elsif In_Use (Pack) then
2515 Note_Redundant_Use (Pack_Name);
2518 elsif Present (Renamed_Object (Pack))
2519 and then In_Use (Renamed_Object (Pack))
2521 Note_Redundant_Use (Pack_Name);
2529 ------------------------
2530 -- Attribute_Renaming --
2531 ------------------------
2533 procedure Attribute_Renaming (N : Node_Id) is
2534 Loc : constant Source_Ptr := Sloc (N);
2535 Nam : constant Node_Id := Name (N);
2536 Spec : constant Node_Id := Specification (N);
2537 New_S : constant Entity_Id := Defining_Unit_Name (Spec);
2538 Aname : constant Name_Id := Attribute_Name (Nam);
2540 Form_Num : Nat := 0;
2541 Expr_List : List_Id := No_List;
2543 Attr_Node : Node_Id;
2544 Body_Node : Node_Id;
2545 Param_Spec : Node_Id;
2548 Generate_Definition (New_S);
2550 -- This procedure is called in the context of subprogram renaming,
2551 -- and thus the attribute must be one that is a subprogram. All of
2552 -- those have at least one formal parameter, with the singular
2553 -- exception of AST_Entry (which is a real oddity, it is odd that
2554 -- this can be renamed at all!)
2556 if not Is_Non_Empty_List (Parameter_Specifications (Spec)) then
2557 if Aname /= Name_AST_Entry then
2559 ("subprogram renaming an attribute must have formals", N);
2564 Param_Spec := First (Parameter_Specifications (Spec));
2565 while Present (Param_Spec) loop
2566 Form_Num := Form_Num + 1;
2568 if Nkind (Parameter_Type (Param_Spec)) /= N_Access_Definition then
2569 Find_Type (Parameter_Type (Param_Spec));
2571 -- The profile of the new entity denotes the base type (s) of
2572 -- the types given in the specification. For access parameters
2573 -- there are no subtypes involved.
2575 Rewrite (Parameter_Type (Param_Spec),
2577 (Base_Type (Entity (Parameter_Type (Param_Spec))), Loc));
2580 if No (Expr_List) then
2581 Expr_List := New_List;
2584 Append_To (Expr_List,
2585 Make_Identifier (Loc,
2586 Chars => Chars (Defining_Identifier (Param_Spec))));
2588 -- The expressions in the attribute reference are not freeze
2589 -- points. Neither is the attribute as a whole, see below.
2591 Set_Must_Not_Freeze (Last (Expr_List));
2596 -- Immediate error if too many formals. Other mismatches in numbers
2597 -- of number of types of parameters are detected when we analyze the
2598 -- body of the subprogram that we construct.
2600 if Form_Num > 2 then
2601 Error_Msg_N ("too many formals for attribute", N);
2603 -- Error if the attribute reference has expressions that look
2604 -- like formal parameters.
2606 elsif Present (Expressions (Nam)) then
2607 Error_Msg_N ("illegal expressions in attribute reference", Nam);
2610 Aname = Name_Compose or else
2611 Aname = Name_Exponent or else
2612 Aname = Name_Leading_Part or else
2613 Aname = Name_Pos or else
2614 Aname = Name_Round or else
2615 Aname = Name_Scaling or else
2618 if Nkind (N) = N_Subprogram_Renaming_Declaration
2619 and then Present (Corresponding_Formal_Spec (N))
2622 ("generic actual cannot be attribute involving universal type",
2626 ("attribute involving a universal type cannot be renamed",
2631 -- AST_Entry is an odd case. It doesn't really make much sense to
2632 -- allow it to be renamed, but that's the DEC rule, so we have to
2633 -- do it right. The point is that the AST_Entry call should be made
2634 -- now, and what the function will return is the returned value.
2636 -- Note that there is no Expr_List in this case anyway
2638 if Aname = Name_AST_Entry then
2644 Ent := Make_Defining_Identifier (Loc, New_Internal_Name ('R'));
2647 Make_Object_Declaration (Loc,
2648 Defining_Identifier => Ent,
2649 Object_Definition =>
2650 New_Occurrence_Of (RTE (RE_AST_Handler), Loc),
2652 Constant_Present => True);
2654 Set_Assignment_OK (Decl, True);
2655 Insert_Action (N, Decl);
2656 Attr_Node := Make_Identifier (Loc, Chars (Ent));
2659 -- For all other attributes, we rewrite the attribute node to have
2660 -- a list of expressions corresponding to the subprogram formals.
2661 -- A renaming declaration is not a freeze point, and the analysis of
2662 -- the attribute reference should not freeze the type of the prefix.
2666 Make_Attribute_Reference (Loc,
2667 Prefix => Prefix (Nam),
2668 Attribute_Name => Aname,
2669 Expressions => Expr_List);
2671 Set_Must_Not_Freeze (Attr_Node);
2672 Set_Must_Not_Freeze (Prefix (Nam));
2675 -- Case of renaming a function
2677 if Nkind (Spec) = N_Function_Specification then
2678 if Is_Procedure_Attribute_Name (Aname) then
2679 Error_Msg_N ("attribute can only be renamed as procedure", Nam);
2683 Find_Type (Result_Definition (Spec));
2684 Rewrite (Result_Definition (Spec),
2686 Base_Type (Entity (Result_Definition (Spec))), Loc));
2689 Make_Subprogram_Body (Loc,
2690 Specification => Spec,
2691 Declarations => New_List,
2692 Handled_Statement_Sequence =>
2693 Make_Handled_Sequence_Of_Statements (Loc,
2694 Statements => New_List (
2695 Make_Simple_Return_Statement (Loc,
2696 Expression => Attr_Node))));
2698 -- Case of renaming a procedure
2701 if not Is_Procedure_Attribute_Name (Aname) then
2702 Error_Msg_N ("attribute can only be renamed as function", Nam);
2707 Make_Subprogram_Body (Loc,
2708 Specification => Spec,
2709 Declarations => New_List,
2710 Handled_Statement_Sequence =>
2711 Make_Handled_Sequence_Of_Statements (Loc,
2712 Statements => New_List (Attr_Node)));
2715 -- In case of tagged types we add the body of the generated function to
2716 -- the freezing actions of the type (because in the general case such
2717 -- type is still not frozen). We exclude from this processing generic
2718 -- formal subprograms found in instantiations and AST_Entry renamings.
2720 if not Present (Corresponding_Formal_Spec (N))
2721 and then Etype (Nam) /= RTE (RE_AST_Handler)
2724 P : constant Entity_Id := Prefix (Nam);
2729 if Is_Tagged_Type (Etype (P)) then
2730 Ensure_Freeze_Node (Etype (P));
2731 Append_Freeze_Action (Etype (P), Body_Node);
2733 Rewrite (N, Body_Node);
2735 Set_Etype (New_S, Base_Type (Etype (New_S)));
2739 -- Generic formal subprograms or AST_Handler renaming
2742 Rewrite (N, Body_Node);
2744 Set_Etype (New_S, Base_Type (Etype (New_S)));
2747 if Is_Compilation_Unit (New_S) then
2749 ("a library unit can only rename another library unit", N);
2752 -- We suppress elaboration warnings for the resulting entity, since
2753 -- clearly they are not needed, and more particularly, in the case
2754 -- of a generic formal subprogram, the resulting entity can appear
2755 -- after the instantiation itself, and thus look like a bogus case
2756 -- of access before elaboration.
2758 Set_Suppress_Elaboration_Warnings (New_S);
2760 end Attribute_Renaming;
2762 ----------------------
2763 -- Chain_Use_Clause --
2764 ----------------------
2766 procedure Chain_Use_Clause (N : Node_Id) is
2768 Level : Int := Scope_Stack.Last;
2771 if not Is_Compilation_Unit (Current_Scope)
2772 or else not Is_Child_Unit (Current_Scope)
2774 null; -- Common case
2776 elsif Defining_Entity (Parent (N)) = Current_Scope then
2777 null; -- Common case for compilation unit
2780 -- If declaration appears in some other scope, it must be in some
2781 -- parent unit when compiling a child.
2783 Pack := Defining_Entity (Parent (N));
2784 if not In_Open_Scopes (Pack) then
2785 null; -- default as well
2788 -- Find entry for parent unit in scope stack
2790 while Scope_Stack.Table (Level).Entity /= Pack loop
2796 Set_Next_Use_Clause (N,
2797 Scope_Stack.Table (Level).First_Use_Clause);
2798 Scope_Stack.Table (Level).First_Use_Clause := N;
2799 end Chain_Use_Clause;
2801 ---------------------------
2802 -- Check_Frozen_Renaming --
2803 ---------------------------
2805 procedure Check_Frozen_Renaming (N : Node_Id; Subp : Entity_Id) is
2811 and then not Has_Completion (Subp)
2815 (Parent (Declaration_Node (Subp)), Defining_Entity (N));
2817 if Is_Entity_Name (Name (N)) then
2818 Old_S := Entity (Name (N));
2820 if not Is_Frozen (Old_S)
2821 and then Operating_Mode /= Check_Semantics
2823 Append_Freeze_Action (Old_S, B_Node);
2825 Insert_After (N, B_Node);
2829 if Is_Intrinsic_Subprogram (Old_S)
2830 and then not In_Instance
2833 ("subprogram used in renaming_as_body cannot be intrinsic",
2838 Insert_After (N, B_Node);
2842 end Check_Frozen_Renaming;
2844 -----------------------------------
2845 -- Check_In_Previous_With_Clause --
2846 -----------------------------------
2848 procedure Check_In_Previous_With_Clause
2852 Pack : constant Entity_Id := Entity (Original_Node (Nam));
2857 Item := First (Context_Items (Parent (N)));
2859 while Present (Item)
2862 if Nkind (Item) = N_With_Clause
2864 -- Protect the frontend against previous critical errors
2866 and then Nkind (Name (Item)) /= N_Selected_Component
2867 and then Entity (Name (Item)) = Pack
2871 -- Find root library unit in with_clause
2873 while Nkind (Par) = N_Expanded_Name loop
2874 Par := Prefix (Par);
2877 if Is_Child_Unit (Entity (Original_Node (Par))) then
2879 ("& is not directly visible", Par, Entity (Par));
2888 -- On exit, package is not mentioned in a previous with_clause.
2889 -- Check if its prefix is.
2891 if Nkind (Nam) = N_Expanded_Name then
2892 Check_In_Previous_With_Clause (N, Prefix (Nam));
2894 elsif Pack /= Any_Id then
2895 Error_Msg_NE ("& is not visible", Nam, Pack);
2897 end Check_In_Previous_With_Clause;
2899 ---------------------------------
2900 -- Check_Library_Unit_Renaming --
2901 ---------------------------------
2903 procedure Check_Library_Unit_Renaming (N : Node_Id; Old_E : Entity_Id) is
2907 if Nkind (Parent (N)) /= N_Compilation_Unit then
2910 -- Check for library unit. Note that we used to check for the scope
2911 -- being Standard here, but that was wrong for Standard itself.
2913 elsif not Is_Compilation_Unit (Old_E)
2914 and then not Is_Child_Unit (Old_E)
2916 Error_Msg_N ("renamed unit must be a library unit", Name (N));
2918 -- Entities defined in Standard (operators and boolean literals) cannot
2919 -- be renamed as library units.
2921 elsif Scope (Old_E) = Standard_Standard
2922 and then Sloc (Old_E) = Standard_Location
2924 Error_Msg_N ("renamed unit must be a library unit", Name (N));
2926 elsif Present (Parent_Spec (N))
2927 and then Nkind (Unit (Parent_Spec (N))) = N_Generic_Package_Declaration
2928 and then not Is_Child_Unit (Old_E)
2931 ("renamed unit must be a child unit of generic parent", Name (N));
2933 elsif Nkind (N) in N_Generic_Renaming_Declaration
2934 and then Nkind (Name (N)) = N_Expanded_Name
2935 and then Is_Generic_Instance (Entity (Prefix (Name (N))))
2936 and then Is_Generic_Unit (Old_E)
2939 ("renamed generic unit must be a library unit", Name (N));
2941 elsif Is_Package_Or_Generic_Package (Old_E) then
2943 -- Inherit categorization flags
2945 New_E := Defining_Entity (N);
2946 Set_Is_Pure (New_E, Is_Pure (Old_E));
2947 Set_Is_Preelaborated (New_E, Is_Preelaborated (Old_E));
2948 Set_Is_Remote_Call_Interface (New_E,
2949 Is_Remote_Call_Interface (Old_E));
2950 Set_Is_Remote_Types (New_E, Is_Remote_Types (Old_E));
2951 Set_Is_Shared_Passive (New_E, Is_Shared_Passive (Old_E));
2953 end Check_Library_Unit_Renaming;
2959 procedure End_Scope is
2965 Id := First_Entity (Current_Scope);
2966 while Present (Id) loop
2967 -- An entity in the current scope is not necessarily the first one
2968 -- on its homonym chain. Find its predecessor if any,
2969 -- If it is an internal entity, it will not be in the visibility
2970 -- chain altogether, and there is nothing to unchain.
2972 if Id /= Current_Entity (Id) then
2973 Prev := Current_Entity (Id);
2974 while Present (Prev)
2975 and then Present (Homonym (Prev))
2976 and then Homonym (Prev) /= Id
2978 Prev := Homonym (Prev);
2981 -- Skip to end of loop if Id is not in the visibility chain
2983 if No (Prev) or else Homonym (Prev) /= Id then
2991 Set_Is_Immediately_Visible (Id, False);
2993 Outer := Homonym (Id);
2994 while Present (Outer) and then Scope (Outer) = Current_Scope loop
2995 Outer := Homonym (Outer);
2998 -- Reset homonym link of other entities, but do not modify link
2999 -- between entities in current scope, so that the back-end can have
3000 -- a proper count of local overloadings.
3003 Set_Name_Entity_Id (Chars (Id), Outer);
3005 elsif Scope (Prev) /= Scope (Id) then
3006 Set_Homonym (Prev, Outer);
3013 -- If the scope generated freeze actions, place them before the
3014 -- current declaration and analyze them. Type declarations and
3015 -- the bodies of initialization procedures can generate such nodes.
3016 -- We follow the parent chain until we reach a list node, which is
3017 -- the enclosing list of declarations. If the list appears within
3018 -- a protected definition, move freeze nodes outside the protected
3022 (Scope_Stack.Table (Scope_Stack.Last).Pending_Freeze_Actions)
3026 L : constant List_Id := Scope_Stack.Table
3027 (Scope_Stack.Last).Pending_Freeze_Actions;
3030 if Is_Itype (Current_Scope) then
3031 Decl := Associated_Node_For_Itype (Current_Scope);
3033 Decl := Parent (Current_Scope);
3038 while not (Is_List_Member (Decl))
3039 or else Nkind_In (Parent (Decl), N_Protected_Definition,
3042 Decl := Parent (Decl);
3045 Insert_List_Before_And_Analyze (Decl, L);
3054 ---------------------
3055 -- End_Use_Clauses --
3056 ---------------------
3058 procedure End_Use_Clauses (Clause : Node_Id) is
3062 -- Remove Use_Type clauses first, because they affect the
3063 -- visibility of operators in subsequent used packages.
3066 while Present (U) loop
3067 if Nkind (U) = N_Use_Type_Clause then
3071 Next_Use_Clause (U);
3075 while Present (U) loop
3076 if Nkind (U) = N_Use_Package_Clause then
3077 End_Use_Package (U);
3080 Next_Use_Clause (U);
3082 end End_Use_Clauses;
3084 ---------------------
3085 -- End_Use_Package --
3086 ---------------------
3088 procedure End_Use_Package (N : Node_Id) is
3089 Pack_Name : Node_Id;
3094 function Is_Primitive_Operator
3096 F : Entity_Id) return Boolean;
3097 -- Check whether Op is a primitive operator of a use-visible type
3099 ---------------------------
3100 -- Is_Primitive_Operator --
3101 ---------------------------
3103 function Is_Primitive_Operator
3105 F : Entity_Id) return Boolean
3107 T : constant Entity_Id := Etype (F);
3110 and then Scope (T) = Scope (Op);
3111 end Is_Primitive_Operator;
3113 -- Start of processing for End_Use_Package
3116 Pack_Name := First (Names (N));
3117 while Present (Pack_Name) loop
3119 -- Test that Pack_Name actually denotes a package before processing
3121 if Is_Entity_Name (Pack_Name)
3122 and then Ekind (Entity (Pack_Name)) = E_Package
3124 Pack := Entity (Pack_Name);
3126 if In_Open_Scopes (Pack) then
3129 elsif not Redundant_Use (Pack_Name) then
3130 Set_In_Use (Pack, False);
3131 Set_Current_Use_Clause (Pack, Empty);
3133 Id := First_Entity (Pack);
3134 while Present (Id) loop
3136 -- Preserve use-visibility of operators that are primitive
3137 -- operators of a type that is use-visible through an active
3140 if Nkind (Id) = N_Defining_Operator_Symbol
3142 (Is_Primitive_Operator (Id, First_Formal (Id))
3144 (Present (Next_Formal (First_Formal (Id)))
3146 Is_Primitive_Operator
3147 (Id, Next_Formal (First_Formal (Id)))))
3152 Set_Is_Potentially_Use_Visible (Id, False);
3155 if Is_Private_Type (Id)
3156 and then Present (Full_View (Id))
3158 Set_Is_Potentially_Use_Visible (Full_View (Id), False);
3164 if Present (Renamed_Object (Pack)) then
3165 Set_In_Use (Renamed_Object (Pack), False);
3166 Set_Current_Use_Clause (Renamed_Object (Pack), Empty);
3169 if Chars (Pack) = Name_System
3170 and then Scope (Pack) = Standard_Standard
3171 and then Present_System_Aux
3173 Id := First_Entity (System_Aux_Id);
3174 while Present (Id) loop
3175 Set_Is_Potentially_Use_Visible (Id, False);
3177 if Is_Private_Type (Id)
3178 and then Present (Full_View (Id))
3180 Set_Is_Potentially_Use_Visible (Full_View (Id), False);
3186 Set_In_Use (System_Aux_Id, False);
3190 Set_Redundant_Use (Pack_Name, False);
3197 if Present (Hidden_By_Use_Clause (N)) then
3198 Elmt := First_Elmt (Hidden_By_Use_Clause (N));
3199 while Present (Elmt) loop
3200 Set_Is_Immediately_Visible (Node (Elmt));
3204 Set_Hidden_By_Use_Clause (N, No_Elist);
3206 end End_Use_Package;
3212 procedure End_Use_Type (N : Node_Id) is
3219 Id := First (Subtype_Marks (N));
3220 while Present (Id) loop
3222 -- A call to rtsfind may occur while analyzing a use_type clause,
3223 -- in which case the type marks are not resolved yet, and there is
3224 -- nothing to remove.
3226 if not Is_Entity_Name (Id)
3227 or else No (Entity (Id))
3235 or else From_With_Type (T)
3239 -- Note that the use_Type clause may mention a subtype of the type
3240 -- whose primitive operations have been made visible. Here as
3241 -- elsewhere, it is the base type that matters for visibility.
3243 elsif In_Open_Scopes (Scope (Base_Type (T))) then
3246 elsif not Redundant_Use (Id) then
3247 Set_In_Use (T, False);
3248 Set_In_Use (Base_Type (T), False);
3249 Set_Current_Use_Clause (T, Empty);
3250 Set_Current_Use_Clause (Base_Type (T), Empty);
3251 Op_List := Collect_Primitive_Operations (T);
3253 Elmt := First_Elmt (Op_List);
3254 while Present (Elmt) loop
3255 if Nkind (Node (Elmt)) = N_Defining_Operator_Symbol then
3256 Set_Is_Potentially_Use_Visible (Node (Elmt), False);
3268 ----------------------
3269 -- Find_Direct_Name --
3270 ----------------------
3272 procedure Find_Direct_Name (N : Node_Id) is
3277 Inst : Entity_Id := Empty;
3278 -- Enclosing instance, if any
3280 Homonyms : Entity_Id;
3281 -- Saves start of homonym chain
3283 Nvis_Entity : Boolean;
3284 -- Set True to indicate that at there is at least one entity on the
3285 -- homonym chain which, while not visible, is visible enough from the
3286 -- user point of view to warrant an error message of "not visible"
3287 -- rather than undefined.
3289 Nvis_Is_Private_Subprg : Boolean := False;
3290 -- Ada 2005 (AI-262): Set True to indicate that a form of Beaujolais
3291 -- effect concerning library subprograms has been detected. Used to
3292 -- generate the precise error message.
3294 function From_Actual_Package (E : Entity_Id) return Boolean;
3295 -- Returns true if the entity is declared in a package that is
3296 -- an actual for a formal package of the current instance. Such an
3297 -- entity requires special handling because it may be use-visible
3298 -- but hides directly visible entities defined outside the instance.
3300 function Is_Actual_Parameter return Boolean;
3301 -- This function checks if the node N is an identifier that is an actual
3302 -- parameter of a procedure call. If so it returns True, otherwise it
3303 -- return False. The reason for this check is that at this stage we do
3304 -- not know what procedure is being called if the procedure might be
3305 -- overloaded, so it is premature to go setting referenced flags or
3306 -- making calls to Generate_Reference. We will wait till Resolve_Actuals
3307 -- for that processing
3309 function Known_But_Invisible (E : Entity_Id) return Boolean;
3310 -- This function determines whether the entity E (which is not
3311 -- visible) can reasonably be considered to be known to the writer
3312 -- of the reference. This is a heuristic test, used only for the
3313 -- purposes of figuring out whether we prefer to complain that an
3314 -- entity is undefined or invisible (and identify the declaration
3315 -- of the invisible entity in the latter case). The point here is
3316 -- that we don't want to complain that something is invisible and
3317 -- then point to something entirely mysterious to the writer.
3319 procedure Nvis_Messages;
3320 -- Called if there are no visible entries for N, but there is at least
3321 -- one non-directly visible, or hidden declaration. This procedure
3322 -- outputs an appropriate set of error messages.
3324 procedure Undefined (Nvis : Boolean);
3325 -- This function is called if the current node has no corresponding
3326 -- visible entity or entities. The value set in Msg indicates whether
3327 -- an error message was generated (multiple error messages for the
3328 -- same variable are generally suppressed, see body for details).
3329 -- Msg is True if an error message was generated, False if not. This
3330 -- value is used by the caller to determine whether or not to output
3331 -- additional messages where appropriate. The parameter is set False
3332 -- to get the message "X is undefined", and True to get the message
3333 -- "X is not visible".
3335 -------------------------
3336 -- From_Actual_Package --
3337 -------------------------
3339 function From_Actual_Package (E : Entity_Id) return Boolean is
3340 Scop : constant Entity_Id := Scope (E);
3344 if not In_Instance then
3347 Inst := Current_Scope;
3348 while Present (Inst)
3349 and then Ekind (Inst) /= E_Package
3350 and then not Is_Generic_Instance (Inst)
3352 Inst := Scope (Inst);
3359 Act := First_Entity (Inst);
3360 while Present (Act) loop
3361 if Ekind (Act) = E_Package then
3363 -- Check for end of actuals list
3365 if Renamed_Object (Act) = Inst then
3368 elsif Present (Associated_Formal_Package (Act))
3369 and then Renamed_Object (Act) = Scop
3371 -- Entity comes from (instance of) formal package
3386 end From_Actual_Package;
3388 -------------------------
3389 -- Is_Actual_Parameter --
3390 -------------------------
3392 function Is_Actual_Parameter return Boolean is
3395 Nkind (N) = N_Identifier
3397 (Nkind (Parent (N)) = N_Procedure_Call_Statement
3399 (Nkind (Parent (N)) = N_Parameter_Association
3400 and then N = Explicit_Actual_Parameter (Parent (N))
3401 and then Nkind (Parent (Parent (N))) =
3402 N_Procedure_Call_Statement));
3403 end Is_Actual_Parameter;
3405 -------------------------
3406 -- Known_But_Invisible --
3407 -------------------------
3409 function Known_But_Invisible (E : Entity_Id) return Boolean is
3410 Fname : File_Name_Type;
3413 -- Entities in Standard are always considered to be known
3415 if Sloc (E) <= Standard_Location then
3418 -- An entity that does not come from source is always considered
3419 -- to be unknown, since it is an artifact of code expansion.
3421 elsif not Comes_From_Source (E) then
3424 -- In gnat internal mode, we consider all entities known
3426 elsif GNAT_Mode then
3430 -- Here we have an entity that is not from package Standard, and
3431 -- which comes from Source. See if it comes from an internal file.
3433 Fname := Unit_File_Name (Get_Source_Unit (E));
3435 -- Case of from internal file
3437 if Is_Internal_File_Name (Fname) then
3439 -- Private part entities in internal files are never considered
3440 -- to be known to the writer of normal application code.
3442 if Is_Hidden (E) then
3446 -- Entities from System packages other than System and
3447 -- System.Storage_Elements are not considered to be known.
3448 -- System.Auxxxx files are also considered known to the user.
3450 -- Should refine this at some point to generally distinguish
3451 -- between known and unknown internal files ???
3453 Get_Name_String (Fname);
3458 Name_Buffer (1 .. 2) /= "s-"
3460 Name_Buffer (3 .. 8) = "stoele"
3462 Name_Buffer (3 .. 5) = "aux";
3464 -- If not an internal file, then entity is definitely known,
3465 -- even if it is in a private part (the message generated will
3466 -- note that it is in a private part)
3471 end Known_But_Invisible;
3477 procedure Nvis_Messages is
3478 Comp_Unit : Node_Id;
3480 Hidden : Boolean := False;
3484 -- Ada 2005 (AI-262): Generate a precise error concerning the
3485 -- Beaujolais effect that was previously detected
3487 if Nvis_Is_Private_Subprg then
3489 pragma Assert (Nkind (E2) = N_Defining_Identifier
3490 and then Ekind (E2) = E_Function
3491 and then Scope (E2) = Standard_Standard
3492 and then Has_Private_With (E2));
3494 -- Find the sloc corresponding to the private with'ed unit
3496 Comp_Unit := Cunit (Current_Sem_Unit);
3497 Error_Msg_Sloc := No_Location;
3499 Item := First (Context_Items (Comp_Unit));
3500 while Present (Item) loop
3501 if Nkind (Item) = N_With_Clause
3502 and then Private_Present (Item)
3503 and then Entity (Name (Item)) = E2
3505 Error_Msg_Sloc := Sloc (Item);
3512 pragma Assert (Error_Msg_Sloc /= No_Location);
3514 Error_Msg_N ("(Ada 2005): hidden by private with clause #", N);
3518 Undefined (Nvis => True);
3522 -- First loop does hidden declarations
3525 while Present (Ent) loop
3526 if Is_Potentially_Use_Visible (Ent) then
3528 Error_Msg_N ("multiple use clauses cause hiding!", N);
3532 Error_Msg_Sloc := Sloc (Ent);
3533 Error_Msg_N ("hidden declaration#!", N);
3536 Ent := Homonym (Ent);
3539 -- If we found hidden declarations, then that's enough, don't
3540 -- bother looking for non-visible declarations as well.
3546 -- Second loop does non-directly visible declarations
3549 while Present (Ent) loop
3550 if not Is_Potentially_Use_Visible (Ent) then
3552 -- Do not bother the user with unknown entities
3554 if not Known_But_Invisible (Ent) then
3558 Error_Msg_Sloc := Sloc (Ent);
3560 -- Output message noting that there is a non-visible
3561 -- declaration, distinguishing the private part case.
3563 if Is_Hidden (Ent) then
3564 Error_Msg_N ("non-visible (private) declaration#!", N);
3566 Error_Msg_N ("non-visible declaration#!", N);
3568 if Is_Compilation_Unit (Ent)
3570 Nkind (Parent (Parent (N))) = N_Use_Package_Clause
3572 Error_Msg_Qual_Level := 99;
3573 Error_Msg_NE ("\\missing `WITH &;`", N, Ent);
3574 Error_Msg_Qual_Level := 0;
3578 -- Set entity and its containing package as referenced. We
3579 -- can't be sure of this, but this seems a better choice
3580 -- to avoid unused entity messages.
3582 if Comes_From_Source (Ent) then
3583 Set_Referenced (Ent);
3584 Set_Referenced (Cunit_Entity (Get_Source_Unit (Ent)));
3589 Ent := Homonym (Ent);
3598 procedure Undefined (Nvis : Boolean) is
3599 Emsg : Error_Msg_Id;
3602 -- We should never find an undefined internal name. If we do, then
3603 -- see if we have previous errors. If so, ignore on the grounds that
3604 -- it is probably a cascaded message (e.g. a block label from a badly
3605 -- formed block). If no previous errors, then we have a real internal
3606 -- error of some kind so raise an exception.
3608 if Is_Internal_Name (Chars (N)) then
3609 if Total_Errors_Detected /= 0 then
3612 raise Program_Error;
3616 -- A very specialized error check, if the undefined variable is
3617 -- a case tag, and the case type is an enumeration type, check
3618 -- for a possible misspelling, and if so, modify the identifier
3620 -- Named aggregate should also be handled similarly ???
3622 if Nkind (N) = N_Identifier
3623 and then Nkind (Parent (N)) = N_Case_Statement_Alternative
3626 Case_Stm : constant Node_Id := Parent (Parent (N));
3627 Case_Typ : constant Entity_Id := Etype (Expression (Case_Stm));
3632 if Is_Enumeration_Type (Case_Typ)
3633 and then not Is_Standard_Character_Type (Case_Typ)
3635 Lit := First_Literal (Case_Typ);
3636 Get_Name_String (Chars (Lit));
3638 if Chars (Lit) /= Chars (N)
3639 and then Is_Bad_Spelling_Of (Chars (N), Chars (Lit)) then
3640 Error_Msg_Node_2 := Lit;
3642 ("& is undefined, assume misspelling of &", N);
3643 Rewrite (N, New_Occurrence_Of (Lit, Sloc (N)));
3647 Lit := Next_Literal (Lit);
3652 -- Normal processing
3654 Set_Entity (N, Any_Id);
3655 Set_Etype (N, Any_Type);
3657 -- We use the table Urefs to keep track of entities for which we
3658 -- have issued errors for undefined references. Multiple errors
3659 -- for a single name are normally suppressed, however we modify
3660 -- the error message to alert the programmer to this effect.
3662 for J in Urefs.First .. Urefs.Last loop
3663 if Chars (N) = Chars (Urefs.Table (J).Node) then
3664 if Urefs.Table (J).Err /= No_Error_Msg
3665 and then Sloc (N) /= Urefs.Table (J).Loc
3667 Error_Msg_Node_1 := Urefs.Table (J).Node;
3669 if Urefs.Table (J).Nvis then
3670 Change_Error_Text (Urefs.Table (J).Err,
3671 "& is not visible (more references follow)");
3673 Change_Error_Text (Urefs.Table (J).Err,
3674 "& is undefined (more references follow)");
3677 Urefs.Table (J).Err := No_Error_Msg;
3680 -- Although we will set Msg False, and thus suppress the
3681 -- message, we also set Error_Posted True, to avoid any
3682 -- cascaded messages resulting from the undefined reference.
3685 Set_Error_Posted (N, True);
3690 -- If entry not found, this is first undefined occurrence
3693 Error_Msg_N ("& is not visible!", N);
3697 Error_Msg_N ("& is undefined!", N);
3700 -- A very bizarre special check, if the undefined identifier
3701 -- is put or put_line, then add a special error message (since
3702 -- this is a very common error for beginners to make).
3704 if Chars (N) = Name_Put or else Chars (N) = Name_Put_Line then
3706 ("\\possible missing `WITH Ada.Text_'I'O; " &
3707 "USE Ada.Text_'I'O`!", N);
3709 -- Another special check if N is the prefix of a selected
3710 -- component which is a known unit, add message complaining
3711 -- about missing with for this unit.
3713 elsif Nkind (Parent (N)) = N_Selected_Component
3714 and then N = Prefix (Parent (N))
3715 and then Is_Known_Unit (Parent (N))
3717 Error_Msg_Node_2 := Selector_Name (Parent (N));
3718 Error_Msg_N ("\\missing `WITH &.&;`", Prefix (Parent (N)));
3721 -- Now check for possible misspellings
3725 Ematch : Entity_Id := Empty;
3727 Last_Name_Id : constant Name_Id :=
3728 Name_Id (Nat (First_Name_Id) +
3729 Name_Entries_Count - 1);
3732 for Nam in First_Name_Id .. Last_Name_Id loop
3733 E := Get_Name_Entity_Id (Nam);
3736 and then (Is_Immediately_Visible (E)
3738 Is_Potentially_Use_Visible (E))
3740 if Is_Bad_Spelling_Of (Chars (N), Nam) then
3747 if Present (Ematch) then
3748 Error_Msg_NE ("\possible misspelling of&", N, Ematch);
3753 -- Make entry in undefined references table unless the full errors
3754 -- switch is set, in which case by refraining from generating the
3755 -- table entry, we guarantee that we get an error message for every
3756 -- undefined reference.
3758 if not All_Errors_Mode then
3769 -- Start of processing for Find_Direct_Name
3772 -- If the entity pointer is already set, this is an internal node, or
3773 -- a node that is analyzed more than once, after a tree modification.
3774 -- In such a case there is no resolution to perform, just set the type.
3776 if Present (Entity (N)) then
3777 if Is_Type (Entity (N)) then
3778 Set_Etype (N, Entity (N));
3782 Entyp : constant Entity_Id := Etype (Entity (N));
3785 -- One special case here. If the Etype field is already set,
3786 -- and references the packed array type corresponding to the
3787 -- etype of the referenced entity, then leave it alone. This
3788 -- happens for trees generated from Exp_Pakd, where expressions
3789 -- can be deliberately "mis-typed" to the packed array type.
3791 if Is_Array_Type (Entyp)
3792 and then Is_Packed (Entyp)
3793 and then Present (Etype (N))
3794 and then Etype (N) = Packed_Array_Type (Entyp)
3798 -- If not that special case, then just reset the Etype
3801 Set_Etype (N, Etype (Entity (N)));
3809 -- Here if Entity pointer was not set, we need full visibility analysis
3810 -- First we generate debugging output if the debug E flag is set.
3812 if Debug_Flag_E then
3813 Write_Str ("Looking for ");
3814 Write_Name (Chars (N));
3818 Homonyms := Current_Entity (N);
3819 Nvis_Entity := False;
3822 while Present (E) loop
3824 -- If entity is immediately visible or potentially use visible, then
3825 -- process the entity and we are done.
3827 if Is_Immediately_Visible (E) then
3828 goto Immediately_Visible_Entity;
3830 elsif Is_Potentially_Use_Visible (E) then
3831 goto Potentially_Use_Visible_Entity;
3833 -- Note if a known but invisible entity encountered
3835 elsif Known_But_Invisible (E) then
3836 Nvis_Entity := True;
3839 -- Move to next entity in chain and continue search
3844 -- If no entries on homonym chain that were potentially visible,
3845 -- and no entities reasonably considered as non-visible, then
3846 -- we have a plain undefined reference, with no additional
3847 -- explanation required!
3849 if not Nvis_Entity then
3850 Undefined (Nvis => False);
3852 -- Otherwise there is at least one entry on the homonym chain that
3853 -- is reasonably considered as being known and non-visible.
3861 -- Processing for a potentially use visible entry found. We must search
3862 -- the rest of the homonym chain for two reasons. First, if there is a
3863 -- directly visible entry, then none of the potentially use-visible
3864 -- entities are directly visible (RM 8.4(10)). Second, we need to check
3865 -- for the case of multiple potentially use-visible entries hiding one
3866 -- another and as a result being non-directly visible (RM 8.4(11)).
3868 <<Potentially_Use_Visible_Entity>> declare
3869 Only_One_Visible : Boolean := True;
3870 All_Overloadable : Boolean := Is_Overloadable (E);
3874 while Present (E2) loop
3875 if Is_Immediately_Visible (E2) then
3877 -- If the use-visible entity comes from the actual for a
3878 -- formal package, it hides a directly visible entity from
3879 -- outside the instance.
3881 if From_Actual_Package (E)
3882 and then Scope_Depth (E2) < Scope_Depth (Inst)
3887 goto Immediately_Visible_Entity;
3890 elsif Is_Potentially_Use_Visible (E2) then
3891 Only_One_Visible := False;
3892 All_Overloadable := All_Overloadable and Is_Overloadable (E2);
3894 -- Ada 2005 (AI-262): Protect against a form of Beaujolais effect
3895 -- that can occur in private_with clauses. Example:
3898 -- private with B; package A is
3899 -- package C is function B return Integer;
3901 -- V1 : Integer := B;
3902 -- private function B return Integer;
3903 -- V2 : Integer := B;
3906 -- V1 resolves to A.B, but V2 resolves to library unit B
3908 elsif Ekind (E2) = E_Function
3909 and then Scope (E2) = Standard_Standard
3910 and then Has_Private_With (E2)
3912 Only_One_Visible := False;
3913 All_Overloadable := False;
3914 Nvis_Is_Private_Subprg := True;
3921 -- On falling through this loop, we have checked that there are no
3922 -- immediately visible entities. Only_One_Visible is set if exactly
3923 -- one potentially use visible entity exists. All_Overloadable is
3924 -- set if all the potentially use visible entities are overloadable.
3925 -- The condition for legality is that either there is one potentially
3926 -- use visible entity, or if there is more than one, then all of them
3927 -- are overloadable.
3929 if Only_One_Visible or All_Overloadable then
3932 -- If there is more than one potentially use-visible entity and at
3933 -- least one of them non-overloadable, we have an error (RM 8.4(11).
3934 -- Note that E points to the first such entity on the homonym list.
3935 -- Special case: if one of the entities is declared in an actual
3936 -- package, it was visible in the generic, and takes precedence over
3937 -- other entities that are potentially use-visible. Same if it is
3938 -- declared in a local instantiation of the current instance.
3943 -- Find current instance
3945 Inst := Current_Scope;
3946 while Present (Inst)
3947 and then Inst /= Standard_Standard
3949 if Is_Generic_Instance (Inst) then
3953 Inst := Scope (Inst);
3957 while Present (E2) loop
3958 if From_Actual_Package (E2)
3960 (Is_Generic_Instance (Scope (E2))
3961 and then Scope_Depth (Scope (E2)) > Scope_Depth (Inst))
3974 Is_Predefined_File_Name (Unit_File_Name (Current_Sem_Unit))
3976 -- A use-clause in the body of a system file creates conflict
3977 -- with some entity in a user scope, while rtsfind is active.
3978 -- Keep only the entity coming from another predefined unit.
3981 while Present (E2) loop
3982 if Is_Predefined_File_Name
3983 (Unit_File_Name (Get_Source_Unit (Sloc (E2))))
3992 -- Entity must exist because predefined unit is correct
3994 raise Program_Error;
4003 -- Come here with E set to the first immediately visible entity on
4004 -- the homonym chain. This is the one we want unless there is another
4005 -- immediately visible entity further on in the chain for an inner
4006 -- scope (RM 8.3(8)).
4008 <<Immediately_Visible_Entity>> declare
4013 -- Find scope level of initial entity. When compiling through
4014 -- Rtsfind, the previous context is not completely invisible, and
4015 -- an outer entity may appear on the chain, whose scope is below
4016 -- the entry for Standard that delimits the current scope stack.
4017 -- Indicate that the level for this spurious entry is outside of
4018 -- the current scope stack.
4020 Level := Scope_Stack.Last;
4022 Scop := Scope_Stack.Table (Level).Entity;
4023 exit when Scop = Scope (E);
4025 exit when Scop = Standard_Standard;
4028 -- Now search remainder of homonym chain for more inner entry
4029 -- If the entity is Standard itself, it has no scope, and we
4030 -- compare it with the stack entry directly.
4033 while Present (E2) loop
4034 if Is_Immediately_Visible (E2) then
4036 -- If a generic package contains a local declaration that
4037 -- has the same name as the generic, there may be a visibility
4038 -- conflict in an instance, where the local declaration must
4039 -- also hide the name of the corresponding package renaming.
4040 -- We check explicitly for a package declared by a renaming,
4041 -- whose renamed entity is an instance that is on the scope
4042 -- stack, and that contains a homonym in the same scope. Once
4043 -- we have found it, we know that the package renaming is not
4044 -- immediately visible, and that the identifier denotes the
4045 -- other entity (and its homonyms if overloaded).
4047 if Scope (E) = Scope (E2)
4048 and then Ekind (E) = E_Package
4049 and then Present (Renamed_Object (E))
4050 and then Is_Generic_Instance (Renamed_Object (E))
4051 and then In_Open_Scopes (Renamed_Object (E))
4052 and then Comes_From_Source (N)
4054 Set_Is_Immediately_Visible (E, False);
4058 for J in Level + 1 .. Scope_Stack.Last loop
4059 if Scope_Stack.Table (J).Entity = Scope (E2)
4060 or else Scope_Stack.Table (J).Entity = E2
4073 -- At the end of that loop, E is the innermost immediately
4074 -- visible entity, so we are all set.
4077 -- Come here with entity found, and stored in E
4081 -- When distribution features are available (Get_PCS_Name /=
4082 -- Name_No_DSA), a remote access-to-subprogram type is converted
4083 -- into a record type holding whatever information is needed to
4084 -- perform a remote call on an RCI subprogram. In that case we
4085 -- rewrite any occurrence of the RAS type into the equivalent record
4086 -- type here. 'Access attribute references and RAS dereferences are
4087 -- then implemented using specific TSSs. However when distribution is
4088 -- not available (case of Get_PCS_Name = Name_No_DSA), we bypass the
4089 -- generation of these TSSs, and we must keep the RAS type in its
4090 -- original access-to-subprogram form (since all calls through a
4091 -- value of such type will be local anyway in the absence of a PCS).
4093 if Comes_From_Source (N)
4094 and then Is_Remote_Access_To_Subprogram_Type (E)
4095 and then Expander_Active
4096 and then Get_PCS_Name /= Name_No_DSA
4099 New_Occurrence_Of (Equivalent_Type (E), Sloc (N)));
4104 -- Why no Style_Check here???
4109 Set_Etype (N, Get_Full_View (Etype (E)));
4112 if Debug_Flag_E then
4113 Write_Str (" found ");
4114 Write_Entity_Info (E, " ");
4117 -- If the Ekind of the entity is Void, it means that all homonyms
4118 -- are hidden from all visibility (RM 8.3(5,14-20)). However, this
4119 -- test is skipped if the current scope is a record and the name is
4120 -- a pragma argument expression (case of Atomic and Volatile pragmas
4121 -- and possibly other similar pragmas added later, which are allowed
4122 -- to reference components in the current record).
4124 if Ekind (E) = E_Void
4126 (not Is_Record_Type (Current_Scope)
4127 or else Nkind (Parent (N)) /= N_Pragma_Argument_Association)
4129 Premature_Usage (N);
4131 -- If the entity is overloadable, collect all interpretations of the
4132 -- name for subsequent overload resolution. We optimize a bit here to
4133 -- do this only if we have an overloadable entity that is not on its
4134 -- own on the homonym chain.
4136 elsif Is_Overloadable (E)
4137 and then (Present (Homonym (E)) or else Current_Entity (N) /= E)
4139 Collect_Interps (N);
4141 -- If no homonyms were visible, the entity is unambiguous
4143 if not Is_Overloaded (N) then
4144 if not Is_Actual_Parameter then
4145 Generate_Reference (E, N);
4149 -- Case of non-overloadable entity, set the entity providing that
4150 -- we do not have the case of a discriminant reference within a
4151 -- default expression. Such references are replaced with the
4152 -- corresponding discriminal, which is the formal corresponding to
4153 -- to the discriminant in the initialization procedure.
4156 -- Entity is unambiguous, indicate that it is referenced here
4158 -- For a renaming of an object, always generate simple reference,
4159 -- we don't try to keep track of assignments in this case.
4161 if Is_Object (E) and then Present (Renamed_Object (E)) then
4162 Generate_Reference (E, N);
4164 -- If the renamed entity is a private protected component,
4165 -- reference the original component as well. This needs to be
4166 -- done because the private renamings are installed before any
4167 -- analysis has occurred. Reference to a private component will
4168 -- resolve to the renaming and the original component will be
4169 -- left unreferenced, hence the following.
4171 if Is_Prival (E) then
4172 Generate_Reference (Prival_Link (E), N);
4175 -- One odd case is that we do not want to set the Referenced flag
4176 -- if the entity is a label, and the identifier is the label in
4177 -- the source, since this is not a reference from the point of
4178 -- view of the user.
4180 elsif Nkind (Parent (N)) = N_Label then
4182 R : constant Boolean := Referenced (E);
4185 -- Generate reference unless this is an actual parameter
4186 -- (see comment below)
4188 if Is_Actual_Parameter then
4189 Generate_Reference (E, N);
4190 Set_Referenced (E, R);
4194 -- Normal case, not a label: generate reference
4196 -- ??? It is too early to generate a reference here even if
4197 -- the entity is unambiguous, because the tree is not
4198 -- sufficiently typed at this point for Generate_Reference to
4199 -- determine whether this reference modifies the denoted object
4200 -- (because implicit dereferences cannot be identified prior to
4201 -- full type resolution).
4203 -- The Is_Actual_Parameter routine takes care of one of these
4204 -- cases but there are others probably ???
4207 if not Is_Actual_Parameter then
4208 Generate_Reference (E, N);
4211 Check_Nested_Access (E);
4214 -- Set Entity, with style check if need be. For a discriminant
4215 -- reference, replace by the corresponding discriminal, i.e. the
4216 -- parameter of the initialization procedure that corresponds to
4217 -- the discriminant. If this replacement is being performed, there
4218 -- is no style check to perform.
4220 -- This replacement must not be done if we are currently
4221 -- processing a generic spec or body, because the discriminal
4222 -- has not been not generated in this case.
4224 -- The replacement is also skipped if we are in special
4225 -- spec-expression mode. Why is this skipped in this case ???
4227 if not In_Spec_Expression
4228 or else Ekind (E) /= E_Discriminant
4229 or else Inside_A_Generic
4231 Set_Entity_With_Style_Check (N, E);
4233 -- The replacement is not done either for a task discriminant that
4234 -- appears in a default expression of an entry parameter. See
4235 -- Expand_Discriminant in exp_ch2 for details on their handling.
4237 elsif Is_Concurrent_Type (Scope (E)) then
4244 and then not Nkind_In (P, N_Parameter_Specification,
4245 N_Component_Declaration)
4251 and then Nkind (P) = N_Parameter_Specification
4255 Set_Entity (N, Discriminal (E));
4259 -- Otherwise, this is a discriminant in a context in which
4260 -- it is a reference to the corresponding parameter of the
4261 -- init proc for the enclosing type.
4264 Set_Entity (N, Discriminal (E));
4268 end Find_Direct_Name;
4270 ------------------------
4271 -- Find_Expanded_Name --
4272 ------------------------
4274 -- This routine searches the homonym chain of the entity until it finds
4275 -- an entity declared in the scope denoted by the prefix. If the entity
4276 -- is private, it may nevertheless be immediately visible, if we are in
4277 -- the scope of its declaration.
4279 procedure Find_Expanded_Name (N : Node_Id) is
4280 Selector : constant Node_Id := Selector_Name (N);
4281 Candidate : Entity_Id := Empty;
4287 P_Name := Entity (Prefix (N));
4290 -- If the prefix is a renamed package, look for the entity in the
4291 -- original package.
4293 if Ekind (P_Name) = E_Package
4294 and then Present (Renamed_Object (P_Name))
4296 P_Name := Renamed_Object (P_Name);
4298 -- Rewrite node with entity field pointing to renamed object
4300 Rewrite (Prefix (N), New_Copy (Prefix (N)));
4301 Set_Entity (Prefix (N), P_Name);
4303 -- If the prefix is an object of a concurrent type, look for
4304 -- the entity in the associated task or protected type.
4306 elsif Is_Concurrent_Type (Etype (P_Name)) then
4307 P_Name := Etype (P_Name);
4310 Id := Current_Entity (Selector);
4313 Is_New_Candidate : Boolean;
4316 while Present (Id) loop
4317 if Scope (Id) = P_Name then
4319 Is_New_Candidate := True;
4321 -- Ada 2005 (AI-217): Handle shadow entities associated with types
4322 -- declared in limited-withed nested packages. We don't need to
4323 -- handle E_Incomplete_Subtype entities because the entities in
4324 -- the limited view are always E_Incomplete_Type entities (see
4325 -- Build_Limited_Views). Regarding the expression used to evaluate
4326 -- the scope, it is important to note that the limited view also
4327 -- has shadow entities associated nested packages. For this reason
4328 -- the correct scope of the entity is the scope of the real entity
4329 -- The non-limited view may itself be incomplete, in which case
4330 -- get the full view if available.
4332 elsif From_With_Type (Id)
4333 and then Is_Type (Id)
4334 and then Ekind (Id) = E_Incomplete_Type
4335 and then Present (Non_Limited_View (Id))
4336 and then Scope (Non_Limited_View (Id)) = P_Name
4338 Candidate := Get_Full_View (Non_Limited_View (Id));
4339 Is_New_Candidate := True;
4342 Is_New_Candidate := False;
4345 if Is_New_Candidate then
4346 if Is_Child_Unit (Id) then
4347 exit when Is_Visible_Child_Unit (Id)
4348 or else Is_Immediately_Visible (Id);
4351 exit when not Is_Hidden (Id)
4352 or else Is_Immediately_Visible (Id);
4361 and then (Ekind (P_Name) = E_Procedure
4363 Ekind (P_Name) = E_Function)
4364 and then Is_Generic_Instance (P_Name)
4366 -- Expanded name denotes entity in (instance of) generic subprogram.
4367 -- The entity may be in the subprogram instance, or may denote one of
4368 -- the formals, which is declared in the enclosing wrapper package.
4370 P_Name := Scope (P_Name);
4372 Id := Current_Entity (Selector);
4373 while Present (Id) loop
4374 exit when Scope (Id) = P_Name;
4379 if No (Id) or else Chars (Id) /= Chars (Selector) then
4380 Set_Etype (N, Any_Type);
4382 -- If we are looking for an entity defined in System, try to find it
4383 -- in the child package that may have been provided as an extension
4384 -- to System. The Extend_System pragma will have supplied the name of
4385 -- the extension, which may have to be loaded.
4387 if Chars (P_Name) = Name_System
4388 and then Scope (P_Name) = Standard_Standard
4389 and then Present (System_Extend_Unit)
4390 and then Present_System_Aux (N)
4392 Set_Entity (Prefix (N), System_Aux_Id);
4393 Find_Expanded_Name (N);
4396 elsif Nkind (Selector) = N_Operator_Symbol
4397 and then Has_Implicit_Operator (N)
4399 -- There is an implicit instance of the predefined operator in
4400 -- the given scope. The operator entity is defined in Standard.
4401 -- Has_Implicit_Operator makes the node into an Expanded_Name.
4405 elsif Nkind (Selector) = N_Character_Literal
4406 and then Has_Implicit_Character_Literal (N)
4408 -- If there is no literal defined in the scope denoted by the
4409 -- prefix, the literal may belong to (a type derived from)
4410 -- Standard_Character, for which we have no explicit literals.
4415 -- If the prefix is a single concurrent object, use its name in
4416 -- the error message, rather than that of the anonymous type.
4418 if Is_Concurrent_Type (P_Name)
4419 and then Is_Internal_Name (Chars (P_Name))
4421 Error_Msg_Node_2 := Entity (Prefix (N));
4423 Error_Msg_Node_2 := P_Name;
4426 if P_Name = System_Aux_Id then
4427 P_Name := Scope (P_Name);
4428 Set_Entity (Prefix (N), P_Name);
4431 if Present (Candidate) then
4433 -- If we know that the unit is a child unit we can give a more
4434 -- accurate error message.
4436 if Is_Child_Unit (Candidate) then
4438 -- If the candidate is a private child unit and we are in
4439 -- the visible part of a public unit, specialize the error
4440 -- message. There might be a private with_clause for it,
4441 -- but it is not currently active.
4443 if Is_Private_Descendant (Candidate)
4444 and then Ekind (Current_Scope) = E_Package
4445 and then not In_Private_Part (Current_Scope)
4446 and then not Is_Private_Descendant (Current_Scope)
4448 Error_Msg_N ("private child unit& is not visible here",
4451 -- Normal case where we have a missing with for a child unit
4454 Error_Msg_Qual_Level := 99;
4455 Error_Msg_NE ("missing `WITH &;`", Selector, Candidate);
4456 Error_Msg_Qual_Level := 0;
4459 -- Here we don't know that this is a child unit
4462 Error_Msg_NE ("& is not a visible entity of&", N, Selector);
4466 -- Within the instantiation of a child unit, the prefix may
4467 -- denote the parent instance, but the selector has the name
4468 -- of the original child. Find whether we are within the
4469 -- corresponding instance, and get the proper entity, which
4470 -- can only be an enclosing scope.
4473 and then In_Open_Scopes (P_Name)
4474 and then Is_Generic_Instance (P_Name)
4477 S : Entity_Id := Current_Scope;
4481 for J in reverse 0 .. Scope_Stack.Last loop
4482 S := Scope_Stack.Table (J).Entity;
4484 exit when S = Standard_Standard;
4486 if Ekind (S) = E_Function
4487 or else Ekind (S) = E_Package
4488 or else Ekind (S) = E_Procedure
4490 P := Generic_Parent (Specification
4491 (Unit_Declaration_Node (S)));
4494 and then Chars (Scope (P)) = Chars (O_Name)
4495 and then Chars (P) = Chars (Selector)
4506 -- If this is a selection from Ada, System or Interfaces, then
4507 -- we assume a missing with for the corresponding package.
4509 if Is_Known_Unit (N) then
4510 if not Error_Posted (N) then
4511 Error_Msg_Node_2 := Selector;
4512 Error_Msg_N ("missing `WITH &.&;`", Prefix (N));
4515 -- If this is a selection from a dummy package, then suppress
4516 -- the error message, of course the entity is missing if the
4517 -- package is missing!
4519 elsif Sloc (Error_Msg_Node_2) = No_Location then
4522 -- Here we have the case of an undefined component
4525 Error_Msg_NE ("& not declared in&", N, Selector);
4527 -- Check for misspelling of some entity in prefix
4529 Id := First_Entity (P_Name);
4530 while Present (Id) loop
4531 if Is_Bad_Spelling_Of (Chars (Id), Chars (Selector))
4532 and then not Is_Internal_Name (Chars (Id))
4535 ("possible misspelling of&", Selector, Id);
4542 -- Specialize the message if this may be an instantiation
4543 -- of a child unit that was not mentioned in the context.
4545 if Nkind (Parent (N)) = N_Package_Instantiation
4546 and then Is_Generic_Instance (Entity (Prefix (N)))
4547 and then Is_Compilation_Unit
4548 (Generic_Parent (Parent (Entity (Prefix (N)))))
4550 Error_Msg_Node_2 := Selector;
4551 Error_Msg_N ("\missing `WITH &.&;`", Prefix (N));
4561 if Comes_From_Source (N)
4562 and then Is_Remote_Access_To_Subprogram_Type (Id)
4563 and then Present (Equivalent_Type (Id))
4565 -- If we are not actually generating distribution code (i.e. the
4566 -- current PCS is the dummy non-distributed version), then the
4567 -- Equivalent_Type will be missing, and Id should be treated as
4568 -- a regular access-to-subprogram type.
4570 Id := Equivalent_Type (Id);
4571 Set_Chars (Selector, Chars (Id));
4574 -- Ada 2005 (AI-50217): Check usage of entities in limited withed units
4576 if Ekind (P_Name) = E_Package
4577 and then From_With_Type (P_Name)
4579 if From_With_Type (Id)
4580 or else Is_Type (Id)
4581 or else Ekind (Id) = E_Package
4586 ("limited withed package can only be used to access "
4587 & "incomplete types",
4592 if Is_Task_Type (P_Name)
4593 and then ((Ekind (Id) = E_Entry
4594 and then Nkind (Parent (N)) /= N_Attribute_Reference)
4596 (Ekind (Id) = E_Entry_Family
4598 Nkind (Parent (Parent (N))) /= N_Attribute_Reference))
4600 -- It is an entry call after all, either to the current task (which
4601 -- will deadlock) or to an enclosing task.
4603 Analyze_Selected_Component (N);
4607 Change_Selected_Component_To_Expanded_Name (N);
4609 -- Do style check and generate reference, but skip both steps if this
4610 -- entity has homonyms, since we may not have the right homonym set yet.
4611 -- The proper homonym will be set during the resolve phase.
4613 if Has_Homonym (Id) then
4616 Set_Entity_With_Style_Check (N, Id);
4617 Generate_Reference (Id, N);
4620 if Is_Type (Id) then
4623 Set_Etype (N, Get_Full_View (Etype (Id)));
4626 -- If the Ekind of the entity is Void, it means that all homonyms are
4627 -- hidden from all visibility (RM 8.3(5,14-20)).
4629 if Ekind (Id) = E_Void then
4630 Premature_Usage (N);
4632 elsif Is_Overloadable (Id)
4633 and then Present (Homonym (Id))
4636 H : Entity_Id := Homonym (Id);
4639 while Present (H) loop
4640 if Scope (H) = Scope (Id)
4643 or else Is_Immediately_Visible (H))
4645 Collect_Interps (N);
4652 -- If an extension of System is present, collect possible explicit
4653 -- overloadings declared in the extension.
4655 if Chars (P_Name) = Name_System
4656 and then Scope (P_Name) = Standard_Standard
4657 and then Present (System_Extend_Unit)
4658 and then Present_System_Aux (N)
4660 H := Current_Entity (Id);
4662 while Present (H) loop
4663 if Scope (H) = System_Aux_Id then
4664 Add_One_Interp (N, H, Etype (H));
4673 if Nkind (Selector_Name (N)) = N_Operator_Symbol
4674 and then Scope (Id) /= Standard_Standard
4676 -- In addition to user-defined operators in the given scope, there
4677 -- may be an implicit instance of the predefined operator. The
4678 -- operator (defined in Standard) is found in Has_Implicit_Operator,
4679 -- and added to the interpretations. Procedure Add_One_Interp will
4680 -- determine which hides which.
4682 if Has_Implicit_Operator (N) then
4686 end Find_Expanded_Name;
4688 -------------------------
4689 -- Find_Renamed_Entity --
4690 -------------------------
4692 function Find_Renamed_Entity
4696 Is_Actual : Boolean := False) return Entity_Id
4699 I1 : Interp_Index := 0; -- Suppress junk warnings
4705 function Enclosing_Instance return Entity_Id;
4706 -- If the renaming determines the entity for the default of a formal
4707 -- subprogram nested within another instance, choose the innermost
4708 -- candidate. This is because if the formal has a box, and we are within
4709 -- an enclosing instance where some candidate interpretations are local
4710 -- to this enclosing instance, we know that the default was properly
4711 -- resolved when analyzing the generic, so we prefer the local
4712 -- candidates to those that are external. This is not always the case
4713 -- but is a reasonable heuristic on the use of nested generics. The
4714 -- proper solution requires a full renaming model.
4716 function Is_Visible_Operation (Op : Entity_Id) return Boolean;
4717 -- If the renamed entity is an implicit operator, check whether it is
4718 -- visible because its operand type is properly visible. This check
4719 -- applies to explicit renamed entities that appear in the source in a
4720 -- renaming declaration or a formal subprogram instance, but not to
4721 -- default generic actuals with a name.
4723 function Report_Overload return Entity_Id;
4724 -- List possible interpretations, and specialize message in the
4725 -- case of a generic actual.
4727 function Within (Inner, Outer : Entity_Id) return Boolean;
4728 -- Determine whether a candidate subprogram is defined within the
4729 -- enclosing instance. If yes, it has precedence over outer candidates.
4731 ------------------------
4732 -- Enclosing_Instance --
4733 ------------------------
4735 function Enclosing_Instance return Entity_Id is
4739 if not Is_Generic_Instance (Current_Scope)
4740 and then not Is_Actual
4745 S := Scope (Current_Scope);
4746 while S /= Standard_Standard loop
4747 if Is_Generic_Instance (S) then
4755 end Enclosing_Instance;
4757 --------------------------
4758 -- Is_Visible_Operation --
4759 --------------------------
4761 function Is_Visible_Operation (Op : Entity_Id) return Boolean is
4767 if Ekind (Op) /= E_Operator
4768 or else Scope (Op) /= Standard_Standard
4769 or else (In_Instance
4772 or else Present (Enclosing_Instance)))
4777 -- For a fixed point type operator, check the resulting type,
4778 -- because it may be a mixed mode integer * fixed operation.
4780 if Present (Next_Formal (First_Formal (New_S)))
4781 and then Is_Fixed_Point_Type (Etype (New_S))
4783 Typ := Etype (New_S);
4785 Typ := Etype (First_Formal (New_S));
4788 Btyp := Base_Type (Typ);
4790 if Nkind (Nam) /= N_Expanded_Name then
4791 return (In_Open_Scopes (Scope (Btyp))
4792 or else Is_Potentially_Use_Visible (Btyp)
4793 or else In_Use (Btyp)
4794 or else In_Use (Scope (Btyp)));
4797 Scop := Entity (Prefix (Nam));
4799 if Ekind (Scop) = E_Package
4800 and then Present (Renamed_Object (Scop))
4802 Scop := Renamed_Object (Scop);
4805 -- Operator is visible if prefix of expanded name denotes
4806 -- scope of type, or else type type is defined in System_Aux
4807 -- and the prefix denotes System.
4809 return Scope (Btyp) = Scop
4810 or else (Scope (Btyp) = System_Aux_Id
4811 and then Scope (Scope (Btyp)) = Scop);
4814 end Is_Visible_Operation;
4820 function Within (Inner, Outer : Entity_Id) return Boolean is
4824 Sc := Scope (Inner);
4825 while Sc /= Standard_Standard loop
4836 ---------------------
4837 -- Report_Overload --
4838 ---------------------
4840 function Report_Overload return Entity_Id is
4844 ("ambiguous actual subprogram&, " &
4845 "possible interpretations:", N, Nam);
4848 ("ambiguous subprogram, " &
4849 "possible interpretations:", N);
4852 List_Interps (Nam, N);
4854 end Report_Overload;
4856 -- Start of processing for Find_Renamed_Entry
4860 Candidate_Renaming := Empty;
4862 if not Is_Overloaded (Nam) then
4863 if Entity_Matches_Spec (Entity (Nam), New_S)
4864 and then Is_Visible_Operation (Entity (Nam))
4866 Old_S := Entity (Nam);
4869 Present (First_Formal (Entity (Nam)))
4870 and then Present (First_Formal (New_S))
4871 and then (Base_Type (Etype (First_Formal (Entity (Nam))))
4872 = Base_Type (Etype (First_Formal (New_S))))
4874 Candidate_Renaming := Entity (Nam);
4878 Get_First_Interp (Nam, Ind, It);
4879 while Present (It.Nam) loop
4880 if Entity_Matches_Spec (It.Nam, New_S)
4881 and then Is_Visible_Operation (It.Nam)
4883 if Old_S /= Any_Id then
4885 -- Note: The call to Disambiguate only happens if a
4886 -- previous interpretation was found, in which case I1
4887 -- has received a value.
4889 It1 := Disambiguate (Nam, I1, Ind, Etype (Old_S));
4891 if It1 = No_Interp then
4892 Inst := Enclosing_Instance;
4894 if Present (Inst) then
4895 if Within (It.Nam, Inst) then
4897 elsif Within (Old_S, Inst) then
4900 return Report_Overload;
4904 return Report_Overload;
4918 Present (First_Formal (It.Nam))
4919 and then Present (First_Formal (New_S))
4920 and then (Base_Type (Etype (First_Formal (It.Nam)))
4921 = Base_Type (Etype (First_Formal (New_S))))
4923 Candidate_Renaming := It.Nam;
4926 Get_Next_Interp (Ind, It);
4929 Set_Entity (Nam, Old_S);
4930 Set_Is_Overloaded (Nam, False);
4934 end Find_Renamed_Entity;
4936 -----------------------------
4937 -- Find_Selected_Component --
4938 -----------------------------
4940 procedure Find_Selected_Component (N : Node_Id) is
4941 P : constant Node_Id := Prefix (N);
4944 -- Entity denoted by prefix
4954 if Nkind (P) = N_Error then
4957 -- If the selector already has an entity, the node has been constructed
4958 -- in the course of expansion, and is known to be valid. Do not verify
4959 -- that it is defined for the type (it may be a private component used
4960 -- in the expansion of record equality).
4962 elsif Present (Entity (Selector_Name (N))) then
4964 or else Etype (N) = Any_Type
4967 Sel_Name : constant Node_Id := Selector_Name (N);
4968 Selector : constant Entity_Id := Entity (Sel_Name);
4972 Set_Etype (Sel_Name, Etype (Selector));
4974 if not Is_Entity_Name (P) then
4978 -- Build an actual subtype except for the first parameter
4979 -- of an init proc, where this actual subtype is by
4980 -- definition incorrect, since the object is uninitialized
4981 -- (and does not even have defined discriminants etc.)
4983 if Is_Entity_Name (P)
4984 and then Ekind (Entity (P)) = E_Function
4986 Nam := New_Copy (P);
4988 if Is_Overloaded (P) then
4989 Save_Interps (P, Nam);
4993 Make_Function_Call (Sloc (P), Name => Nam));
4995 Analyze_Selected_Component (N);
4998 elsif Ekind (Selector) = E_Component
4999 and then (not Is_Entity_Name (P)
5000 or else Chars (Entity (P)) /= Name_uInit)
5003 Build_Actual_Subtype_Of_Component (
5004 Etype (Selector), N);
5009 if No (C_Etype) then
5010 C_Etype := Etype (Selector);
5012 Insert_Action (N, C_Etype);
5013 C_Etype := Defining_Identifier (C_Etype);
5016 Set_Etype (N, C_Etype);
5019 -- If this is the name of an entry or protected operation, and
5020 -- the prefix is an access type, insert an explicit dereference,
5021 -- so that entry calls are treated uniformly.
5023 if Is_Access_Type (Etype (P))
5024 and then Is_Concurrent_Type (Designated_Type (Etype (P)))
5027 New_P : constant Node_Id :=
5028 Make_Explicit_Dereference (Sloc (P),
5029 Prefix => Relocate_Node (P));
5032 Set_Etype (P, Designated_Type (Etype (Prefix (P))));
5036 -- If the selected component appears within a default expression
5037 -- and it has an actual subtype, the pre-analysis has not yet
5038 -- completed its analysis, because Insert_Actions is disabled in
5039 -- that context. Within the init proc of the enclosing type we
5040 -- must complete this analysis, if an actual subtype was created.
5042 elsif Inside_Init_Proc then
5044 Typ : constant Entity_Id := Etype (N);
5045 Decl : constant Node_Id := Declaration_Node (Typ);
5047 if Nkind (Decl) = N_Subtype_Declaration
5048 and then not Analyzed (Decl)
5049 and then Is_List_Member (Decl)
5050 and then No (Parent (Decl))
5053 Insert_Action (N, Decl);
5060 elsif Is_Entity_Name (P) then
5061 P_Name := Entity (P);
5063 -- The prefix may denote an enclosing type which is the completion
5064 -- of an incomplete type declaration.
5066 if Is_Type (P_Name) then
5067 Set_Entity (P, Get_Full_View (P_Name));
5068 Set_Etype (P, Entity (P));
5069 P_Name := Entity (P);
5072 P_Type := Base_Type (Etype (P));
5074 if Debug_Flag_E then
5075 Write_Str ("Found prefix type to be ");
5076 Write_Entity_Info (P_Type, " "); Write_Eol;
5079 -- First check for components of a record object (not the
5080 -- result of a call, which is handled below).
5082 if Is_Appropriate_For_Record (P_Type)
5083 and then not Is_Overloadable (P_Name)
5084 and then not Is_Type (P_Name)
5086 -- Selected component of record. Type checking will validate
5087 -- name of selector.
5088 -- ??? could we rewrite an implicit dereference into an explicit
5091 Analyze_Selected_Component (N);
5093 elsif Is_Appropriate_For_Entry_Prefix (P_Type)
5094 and then not In_Open_Scopes (P_Name)
5095 and then (not Is_Concurrent_Type (Etype (P_Name))
5096 or else not In_Open_Scopes (Etype (P_Name)))
5098 -- Call to protected operation or entry. Type checking is
5099 -- needed on the prefix.
5101 Analyze_Selected_Component (N);
5103 elsif (In_Open_Scopes (P_Name)
5104 and then Ekind (P_Name) /= E_Void
5105 and then not Is_Overloadable (P_Name))
5106 or else (Is_Concurrent_Type (Etype (P_Name))
5107 and then In_Open_Scopes (Etype (P_Name)))
5109 -- Prefix denotes an enclosing loop, block, or task, i.e. an
5110 -- enclosing construct that is not a subprogram or accept.
5112 Find_Expanded_Name (N);
5114 elsif Ekind (P_Name) = E_Package then
5115 Find_Expanded_Name (N);
5117 elsif Is_Overloadable (P_Name) then
5119 -- The subprogram may be a renaming (of an enclosing scope) as
5120 -- in the case of the name of the generic within an instantiation.
5122 if (Ekind (P_Name) = E_Procedure
5123 or else Ekind (P_Name) = E_Function)
5124 and then Present (Alias (P_Name))
5125 and then Is_Generic_Instance (Alias (P_Name))
5127 P_Name := Alias (P_Name);
5130 if Is_Overloaded (P) then
5132 -- The prefix must resolve to a unique enclosing construct
5135 Found : Boolean := False;
5140 Get_First_Interp (P, Ind, It);
5141 while Present (It.Nam) loop
5142 if In_Open_Scopes (It.Nam) then
5145 "prefix must be unique enclosing scope", N);
5146 Set_Entity (N, Any_Id);
5147 Set_Etype (N, Any_Type);
5156 Get_Next_Interp (Ind, It);
5161 if In_Open_Scopes (P_Name) then
5162 Set_Entity (P, P_Name);
5163 Set_Is_Overloaded (P, False);
5164 Find_Expanded_Name (N);
5167 -- If no interpretation as an expanded name is possible, it
5168 -- must be a selected component of a record returned by a
5169 -- function call. Reformat prefix as a function call, the rest
5170 -- is done by type resolution. If the prefix is procedure or
5171 -- entry, as is P.X; this is an error.
5173 if Ekind (P_Name) /= E_Function
5174 and then (not Is_Overloaded (P)
5176 Nkind (Parent (N)) = N_Procedure_Call_Statement)
5178 -- Prefix may mention a package that is hidden by a local
5179 -- declaration: let the user know. Scan the full homonym
5180 -- chain, the candidate package may be anywhere on it.
5182 if Present (Homonym (Current_Entity (P_Name))) then
5184 P_Name := Current_Entity (P_Name);
5186 while Present (P_Name) loop
5187 exit when Ekind (P_Name) = E_Package;
5188 P_Name := Homonym (P_Name);
5191 if Present (P_Name) then
5192 Error_Msg_Sloc := Sloc (Entity (Prefix (N)));
5195 ("package& is hidden by declaration#",
5198 Set_Entity (Prefix (N), P_Name);
5199 Find_Expanded_Name (N);
5202 P_Name := Entity (Prefix (N));
5207 ("invalid prefix in selected component&", N, P_Name);
5208 Change_Selected_Component_To_Expanded_Name (N);
5209 Set_Entity (N, Any_Id);
5210 Set_Etype (N, Any_Type);
5213 Nam := New_Copy (P);
5214 Save_Interps (P, Nam);
5216 Make_Function_Call (Sloc (P), Name => Nam));
5218 Analyze_Selected_Component (N);
5222 -- Remaining cases generate various error messages
5225 -- Format node as expanded name, to avoid cascaded errors
5227 Change_Selected_Component_To_Expanded_Name (N);
5228 Set_Entity (N, Any_Id);
5229 Set_Etype (N, Any_Type);
5231 -- Issue error message, but avoid this if error issued already.
5232 -- Use identifier of prefix if one is available.
5234 if P_Name = Any_Id then
5237 elsif Ekind (P_Name) = E_Void then
5238 Premature_Usage (P);
5240 elsif Nkind (P) /= N_Attribute_Reference then
5242 "invalid prefix in selected component&", P);
5244 if Is_Access_Type (P_Type)
5245 and then Ekind (Designated_Type (P_Type)) = E_Incomplete_Type
5248 ("\dereference must not be of an incomplete type " &
5254 "invalid prefix in selected component", P);
5259 -- If prefix is not the name of an entity, it must be an expression,
5260 -- whose type is appropriate for a record. This is determined by
5263 Analyze_Selected_Component (N);
5265 end Find_Selected_Component;
5271 procedure Find_Type (N : Node_Id) is
5281 elsif Nkind (N) = N_Attribute_Reference then
5283 -- Class attribute. This is not valid in Ada 83 mode, but we do not
5284 -- need to enforce that at this point, since the declaration of the
5285 -- tagged type in the prefix would have been flagged already.
5287 if Attribute_Name (N) = Name_Class then
5288 Check_Restriction (No_Dispatch, N);
5289 Find_Type (Prefix (N));
5291 -- Propagate error from bad prefix
5293 if Etype (Prefix (N)) = Any_Type then
5294 Set_Entity (N, Any_Type);
5295 Set_Etype (N, Any_Type);
5299 T := Base_Type (Entity (Prefix (N)));
5301 -- Case where type is not known to be tagged. Its appearance in
5302 -- the prefix of the 'Class attribute indicates that the full view
5305 if not Is_Tagged_Type (T) then
5306 if Ekind (T) = E_Incomplete_Type then
5308 -- It is legal to denote the class type of an incomplete
5309 -- type. The full type will have to be tagged, of course.
5310 -- In Ada 2005 this usage is declared obsolescent, so we
5311 -- warn accordingly.
5313 -- ??? This test is temporarily disabled (always False)
5314 -- because it causes an unwanted warning on GNAT sources
5315 -- (built with -gnatg, which includes Warn_On_Obsolescent_
5316 -- Feature). Once this issue is cleared in the sources, it
5319 if not Is_Tagged_Type (T)
5320 and then Ada_Version >= Ada_05
5321 and then Warn_On_Obsolescent_Feature
5325 ("applying 'Class to an untagged incomplete type"
5326 & " is an obsolescent feature (RM J.11)", N);
5329 Set_Is_Tagged_Type (T);
5330 Set_Primitive_Operations (T, New_Elmt_List);
5331 Make_Class_Wide_Type (T);
5332 Set_Entity (N, Class_Wide_Type (T));
5333 Set_Etype (N, Class_Wide_Type (T));
5335 elsif Ekind (T) = E_Private_Type
5336 and then not Is_Generic_Type (T)
5337 and then In_Private_Part (Scope (T))
5339 -- The Class attribute can be applied to an untagged private
5340 -- type fulfilled by a tagged type prior to the full type
5341 -- declaration (but only within the parent package's private
5342 -- part). Create the class-wide type now and check that the
5343 -- full type is tagged later during its analysis. Note that
5344 -- we do not mark the private type as tagged, unlike the
5345 -- case of incomplete types, because the type must still
5346 -- appear untagged to outside units.
5348 if No (Class_Wide_Type (T)) then
5349 Make_Class_Wide_Type (T);
5352 Set_Entity (N, Class_Wide_Type (T));
5353 Set_Etype (N, Class_Wide_Type (T));
5356 -- Should we introduce a type Any_Tagged and use Wrong_Type
5357 -- here, it would be a bit more consistent???
5360 ("tagged type required, found}",
5361 Prefix (N), First_Subtype (T));
5362 Set_Entity (N, Any_Type);
5366 -- Case of tagged type
5369 if Is_Concurrent_Type (T) then
5370 if No (Corresponding_Record_Type (Entity (Prefix (N)))) then
5372 -- Previous error. Use current type, which at least
5373 -- provides some operations.
5375 C := Entity (Prefix (N));
5378 C := Class_Wide_Type
5379 (Corresponding_Record_Type (Entity (Prefix (N))));
5383 C := Class_Wide_Type (Entity (Prefix (N)));
5386 Set_Entity_With_Style_Check (N, C);
5387 Generate_Reference (C, N);
5391 -- Base attribute, not allowed in Ada 83
5393 elsif Attribute_Name (N) = Name_Base then
5394 if Ada_Version = Ada_83 and then Comes_From_Source (N) then
5396 ("(Ada 83) Base attribute not allowed in subtype mark", N);
5399 Find_Type (Prefix (N));
5400 Typ := Entity (Prefix (N));
5402 if Ada_Version >= Ada_95
5403 and then not Is_Scalar_Type (Typ)
5404 and then not Is_Generic_Type (Typ)
5407 ("prefix of Base attribute must be scalar type",
5410 elsif Sloc (Typ) = Standard_Location
5411 and then Base_Type (Typ) = Typ
5412 and then Warn_On_Redundant_Constructs
5415 ("?redundant attribute, & is its own base type", N, Typ);
5418 T := Base_Type (Typ);
5420 -- Rewrite attribute reference with type itself (see similar
5421 -- processing in Analyze_Attribute, case Base). Preserve
5422 -- prefix if present, for other legality checks.
5424 if Nkind (Prefix (N)) = N_Expanded_Name then
5426 Make_Expanded_Name (Sloc (N),
5428 Prefix => New_Copy (Prefix (Prefix (N))),
5429 Selector_Name => New_Reference_To (T, Sloc (N))));
5432 Rewrite (N, New_Reference_To (T, Sloc (N)));
5439 elsif Attribute_Name (N) = Name_Stub_Type then
5441 -- This is handled in Analyze_Attribute
5445 -- All other attributes are invalid in a subtype mark
5448 Error_Msg_N ("invalid attribute in subtype mark", N);
5454 if Is_Entity_Name (N) then
5455 T_Name := Entity (N);
5457 Error_Msg_N ("subtype mark required in this context", N);
5458 Set_Etype (N, Any_Type);
5462 if T_Name = Any_Id or else Etype (N) = Any_Type then
5464 -- Undefined id. Make it into a valid type
5466 Set_Entity (N, Any_Type);
5468 elsif not Is_Type (T_Name)
5469 and then T_Name /= Standard_Void_Type
5471 Error_Msg_Sloc := Sloc (T_Name);
5472 Error_Msg_N ("subtype mark required in this context", N);
5473 Error_Msg_NE ("\\found & declared#", N, T_Name);
5474 Set_Entity (N, Any_Type);
5477 -- If the type is an incomplete type created to handle
5478 -- anonymous access components of a record type, then the
5479 -- incomplete type is the visible entity and subsequent
5480 -- references will point to it. Mark the original full
5481 -- type as referenced, to prevent spurious warnings.
5483 if Is_Incomplete_Type (T_Name)
5484 and then Present (Full_View (T_Name))
5485 and then not Comes_From_Source (T_Name)
5487 Set_Referenced (Full_View (T_Name));
5490 T_Name := Get_Full_View (T_Name);
5492 -- Ada 2005 (AI-251, AI-50217): Handle interfaces visible through
5493 -- limited-with clauses
5495 if From_With_Type (T_Name)
5496 and then Ekind (T_Name) in Incomplete_Kind
5497 and then Present (Non_Limited_View (T_Name))
5498 and then Is_Interface (Non_Limited_View (T_Name))
5500 T_Name := Non_Limited_View (T_Name);
5503 if In_Open_Scopes (T_Name) then
5504 if Ekind (Base_Type (T_Name)) = E_Task_Type then
5506 -- In Ada 2005, a task name can be used in an access
5507 -- definition within its own body.
5509 if Ada_Version >= Ada_05
5510 and then Nkind (Parent (N)) = N_Access_Definition
5512 Set_Entity (N, T_Name);
5513 Set_Etype (N, T_Name);
5518 ("task type cannot be used as type mark " &
5519 "within its own spec or body", N);
5522 elsif Ekind (Base_Type (T_Name)) = E_Protected_Type then
5524 -- In Ada 2005, a protected name can be used in an access
5525 -- definition within its own body.
5527 if Ada_Version >= Ada_05
5528 and then Nkind (Parent (N)) = N_Access_Definition
5530 Set_Entity (N, T_Name);
5531 Set_Etype (N, T_Name);
5536 ("protected type cannot be used as type mark " &
5537 "within its own spec or body", N);
5541 Error_Msg_N ("type declaration cannot refer to itself", N);
5544 Set_Etype (N, Any_Type);
5545 Set_Entity (N, Any_Type);
5546 Set_Error_Posted (T_Name);
5550 Set_Entity (N, T_Name);
5551 Set_Etype (N, T_Name);
5555 if Present (Etype (N)) and then Comes_From_Source (N) then
5556 if Is_Fixed_Point_Type (Etype (N)) then
5557 Check_Restriction (No_Fixed_Point, N);
5558 elsif Is_Floating_Point_Type (Etype (N)) then
5559 Check_Restriction (No_Floating_Point, N);
5564 ------------------------------------
5565 -- Has_Implicit_Character_Literal --
5566 ------------------------------------
5568 function Has_Implicit_Character_Literal (N : Node_Id) return Boolean is
5570 Found : Boolean := False;
5571 P : constant Entity_Id := Entity (Prefix (N));
5572 Priv_Id : Entity_Id := Empty;
5575 if Ekind (P) = E_Package
5576 and then not In_Open_Scopes (P)
5578 Priv_Id := First_Private_Entity (P);
5581 if P = Standard_Standard then
5582 Change_Selected_Component_To_Expanded_Name (N);
5583 Rewrite (N, Selector_Name (N));
5585 Set_Etype (Original_Node (N), Standard_Character);
5589 Id := First_Entity (P);
5591 and then Id /= Priv_Id
5593 if Is_Standard_Character_Type (Id)
5594 and then Id = Base_Type (Id)
5596 -- We replace the node with the literal itself, resolve as a
5597 -- character, and set the type correctly.
5600 Change_Selected_Component_To_Expanded_Name (N);
5601 Rewrite (N, Selector_Name (N));
5604 Set_Etype (Original_Node (N), Id);
5608 -- More than one type derived from Character in given scope.
5609 -- Collect all possible interpretations.
5611 Add_One_Interp (N, Id, Id);
5619 end Has_Implicit_Character_Literal;
5621 ----------------------
5622 -- Has_Private_With --
5623 ----------------------
5625 function Has_Private_With (E : Entity_Id) return Boolean is
5626 Comp_Unit : constant Node_Id := Cunit (Current_Sem_Unit);
5630 Item := First (Context_Items (Comp_Unit));
5631 while Present (Item) loop
5632 if Nkind (Item) = N_With_Clause
5633 and then Private_Present (Item)
5634 and then Entity (Name (Item)) = E
5643 end Has_Private_With;
5645 ---------------------------
5646 -- Has_Implicit_Operator --
5647 ---------------------------
5649 function Has_Implicit_Operator (N : Node_Id) return Boolean is
5650 Op_Id : constant Name_Id := Chars (Selector_Name (N));
5651 P : constant Entity_Id := Entity (Prefix (N));
5653 Priv_Id : Entity_Id := Empty;
5655 procedure Add_Implicit_Operator
5657 Op_Type : Entity_Id := Empty);
5658 -- Add implicit interpretation to node N, using the type for which a
5659 -- predefined operator exists. If the operator yields a boolean type,
5660 -- the Operand_Type is implicitly referenced by the operator, and a
5661 -- reference to it must be generated.
5663 ---------------------------
5664 -- Add_Implicit_Operator --
5665 ---------------------------
5667 procedure Add_Implicit_Operator
5669 Op_Type : Entity_Id := Empty)
5671 Predef_Op : Entity_Id;
5674 Predef_Op := Current_Entity (Selector_Name (N));
5676 while Present (Predef_Op)
5677 and then Scope (Predef_Op) /= Standard_Standard
5679 Predef_Op := Homonym (Predef_Op);
5682 if Nkind (N) = N_Selected_Component then
5683 Change_Selected_Component_To_Expanded_Name (N);
5686 Add_One_Interp (N, Predef_Op, T);
5688 -- For operators with unary and binary interpretations, add both
5690 if Present (Homonym (Predef_Op)) then
5691 Add_One_Interp (N, Homonym (Predef_Op), T);
5694 -- The node is a reference to a predefined operator, and
5695 -- an implicit reference to the type of its operands.
5697 if Present (Op_Type) then
5698 Generate_Operator_Reference (N, Op_Type);
5700 Generate_Operator_Reference (N, T);
5702 end Add_Implicit_Operator;
5704 -- Start of processing for Has_Implicit_Operator
5707 if Ekind (P) = E_Package
5708 and then not In_Open_Scopes (P)
5710 Priv_Id := First_Private_Entity (P);
5713 Id := First_Entity (P);
5717 -- Boolean operators: an implicit declaration exists if the scope
5718 -- contains a declaration for a derived Boolean type, or for an
5719 -- array of Boolean type.
5721 when Name_Op_And | Name_Op_Not | Name_Op_Or | Name_Op_Xor =>
5722 while Id /= Priv_Id loop
5723 if Valid_Boolean_Arg (Id)
5724 and then Id = Base_Type (Id)
5726 Add_Implicit_Operator (Id);
5733 -- Equality: look for any non-limited type (result is Boolean)
5735 when Name_Op_Eq | Name_Op_Ne =>
5736 while Id /= Priv_Id loop
5738 and then not Is_Limited_Type (Id)
5739 and then Id = Base_Type (Id)
5741 Add_Implicit_Operator (Standard_Boolean, Id);
5748 -- Comparison operators: scalar type, or array of scalar
5750 when Name_Op_Lt | Name_Op_Le | Name_Op_Gt | Name_Op_Ge =>
5751 while Id /= Priv_Id loop
5752 if (Is_Scalar_Type (Id)
5753 or else (Is_Array_Type (Id)
5754 and then Is_Scalar_Type (Component_Type (Id))))
5755 and then Id = Base_Type (Id)
5757 Add_Implicit_Operator (Standard_Boolean, Id);
5764 -- Arithmetic operators: any numeric type
5774 while Id /= Priv_Id loop
5775 if Is_Numeric_Type (Id)
5776 and then Id = Base_Type (Id)
5778 Add_Implicit_Operator (Id);
5785 -- Concatenation: any one-dimensional array type
5787 when Name_Op_Concat =>
5788 while Id /= Priv_Id loop
5789 if Is_Array_Type (Id) and then Number_Dimensions (Id) = 1
5790 and then Id = Base_Type (Id)
5792 Add_Implicit_Operator (Id);
5799 -- What is the others condition here? Should we be using a
5800 -- subtype of Name_Id that would restrict to operators ???
5802 when others => null;
5805 -- If we fall through, then we do not have an implicit operator
5809 end Has_Implicit_Operator;
5811 --------------------
5812 -- In_Open_Scopes --
5813 --------------------
5815 function In_Open_Scopes (S : Entity_Id) return Boolean is
5817 -- Several scope stacks are maintained by Scope_Stack. The base of the
5818 -- currently active scope stack is denoted by the Is_Active_Stack_Base
5819 -- flag in the scope stack entry. Note that the scope stacks used to
5820 -- simply be delimited implicitly by the presence of Standard_Standard
5821 -- at their base, but there now are cases where this is not sufficient
5822 -- because Standard_Standard actually may appear in the middle of the
5823 -- active set of scopes.
5825 for J in reverse 0 .. Scope_Stack.Last loop
5826 if Scope_Stack.Table (J).Entity = S then
5830 -- Check Is_Active_Stack_Base to tell us when to stop, as there are
5831 -- cases where Standard_Standard appears in the middle of the active
5832 -- set of scopes. This affects the declaration and overriding of
5833 -- private inherited operations in instantiations of generic child
5836 exit when Scope_Stack.Table (J).Is_Active_Stack_Base;
5842 -----------------------------
5843 -- Inherit_Renamed_Profile --
5844 -----------------------------
5846 procedure Inherit_Renamed_Profile (New_S : Entity_Id; Old_S : Entity_Id) is
5853 if Ekind (Old_S) = E_Operator then
5854 New_F := First_Formal (New_S);
5856 while Present (New_F) loop
5857 Set_Etype (New_F, Base_Type (Etype (New_F)));
5858 Next_Formal (New_F);
5861 Set_Etype (New_S, Base_Type (Etype (New_S)));
5864 New_F := First_Formal (New_S);
5865 Old_F := First_Formal (Old_S);
5867 while Present (New_F) loop
5868 New_T := Etype (New_F);
5869 Old_T := Etype (Old_F);
5871 -- If the new type is a renaming of the old one, as is the
5872 -- case for actuals in instances, retain its name, to simplify
5873 -- later disambiguation.
5875 if Nkind (Parent (New_T)) = N_Subtype_Declaration
5876 and then Is_Entity_Name (Subtype_Indication (Parent (New_T)))
5877 and then Entity (Subtype_Indication (Parent (New_T))) = Old_T
5881 Set_Etype (New_F, Old_T);
5884 Next_Formal (New_F);
5885 Next_Formal (Old_F);
5888 if Ekind (Old_S) = E_Function
5889 or else Ekind (Old_S) = E_Enumeration_Literal
5891 Set_Etype (New_S, Etype (Old_S));
5894 end Inherit_Renamed_Profile;
5900 procedure Initialize is
5905 -------------------------
5906 -- Install_Use_Clauses --
5907 -------------------------
5909 procedure Install_Use_Clauses
5911 Force_Installation : Boolean := False)
5919 while Present (U) loop
5921 -- Case of USE package
5923 if Nkind (U) = N_Use_Package_Clause then
5924 P := First (Names (U));
5925 while Present (P) loop
5928 if Ekind (Id) = E_Package then
5930 Note_Redundant_Use (P);
5932 elsif Present (Renamed_Object (Id))
5933 and then In_Use (Renamed_Object (Id))
5935 Note_Redundant_Use (P);
5937 elsif Force_Installation or else Applicable_Use (P) then
5938 Use_One_Package (Id, U);
5949 P := First (Subtype_Marks (U));
5950 while Present (P) loop
5951 if not Is_Entity_Name (P)
5952 or else No (Entity (P))
5956 elsif Entity (P) /= Any_Type then
5964 Next_Use_Clause (U);
5966 end Install_Use_Clauses;
5968 -------------------------------------
5969 -- Is_Appropriate_For_Entry_Prefix --
5970 -------------------------------------
5972 function Is_Appropriate_For_Entry_Prefix (T : Entity_Id) return Boolean is
5973 P_Type : Entity_Id := T;
5976 if Is_Access_Type (P_Type) then
5977 P_Type := Designated_Type (P_Type);
5980 return Is_Task_Type (P_Type) or else Is_Protected_Type (P_Type);
5981 end Is_Appropriate_For_Entry_Prefix;
5983 -------------------------------
5984 -- Is_Appropriate_For_Record --
5985 -------------------------------
5987 function Is_Appropriate_For_Record (T : Entity_Id) return Boolean is
5989 function Has_Components (T1 : Entity_Id) return Boolean;
5990 -- Determine if given type has components (i.e. is either a record
5991 -- type or a type that has discriminants).
5993 --------------------
5994 -- Has_Components --
5995 --------------------
5997 function Has_Components (T1 : Entity_Id) return Boolean is
5999 return Is_Record_Type (T1)
6000 or else (Is_Private_Type (T1) and then Has_Discriminants (T1))
6001 or else (Is_Task_Type (T1) and then Has_Discriminants (T1))
6002 or else (Is_Incomplete_Type (T1)
6003 and then From_With_Type (T1)
6004 and then Present (Non_Limited_View (T1))
6005 and then Is_Record_Type
6006 (Get_Full_View (Non_Limited_View (T1))));
6009 -- Start of processing for Is_Appropriate_For_Record
6014 and then (Has_Components (T)
6015 or else (Is_Access_Type (T)
6016 and then Has_Components (Designated_Type (T))));
6017 end Is_Appropriate_For_Record;
6019 ------------------------
6020 -- Note_Redundant_Use --
6021 ------------------------
6023 procedure Note_Redundant_Use (Clause : Node_Id) is
6024 Pack_Name : constant Entity_Id := Entity (Clause);
6025 Cur_Use : constant Node_Id := Current_Use_Clause (Pack_Name);
6026 Decl : constant Node_Id := Parent (Clause);
6028 Prev_Use : Node_Id := Empty;
6029 Redundant : Node_Id := Empty;
6030 -- The Use_Clause which is actually redundant. In the simplest case
6031 -- it is Pack itself, but when we compile a body we install its
6032 -- context before that of its spec, in which case it is the use_clause
6033 -- in the spec that will appear to be redundant, and we want the
6034 -- warning to be placed on the body. Similar complications appear when
6035 -- the redundancy is between a child unit and one of its ancestors.
6038 Set_Redundant_Use (Clause, True);
6040 if not Comes_From_Source (Clause)
6042 or else not Warn_On_Redundant_Constructs
6047 if not Is_Compilation_Unit (Current_Scope) then
6049 -- If the use_clause is in an inner scope, it is made redundant
6050 -- by some clause in the current context, with one exception:
6051 -- If we're compiling a nested package body, and the use_clause
6052 -- comes from the corresponding spec, the clause is not necessarily
6053 -- fully redundant, so we should not warn. If a warning was
6054 -- warranted, it would have been given when the spec was processed.
6056 if Nkind (Parent (Decl)) = N_Package_Specification then
6058 Package_Spec_Entity : constant Entity_Id :=
6059 Defining_Unit_Name (Parent (Decl));
6061 if In_Package_Body (Package_Spec_Entity) then
6067 Redundant := Clause;
6068 Prev_Use := Cur_Use;
6070 elsif Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Body then
6072 Cur_Unit : constant Unit_Number_Type := Get_Source_Unit (Cur_Use);
6073 New_Unit : constant Unit_Number_Type := Get_Source_Unit (Clause);
6077 if Cur_Unit = New_Unit then
6079 -- Redundant clause in same body
6081 Redundant := Clause;
6082 Prev_Use := Cur_Use;
6084 elsif Cur_Unit = Current_Sem_Unit then
6086 -- If the new clause is not in the current unit it has been
6087 -- analyzed first, and it makes the other one redundant.
6088 -- However, if the new clause appears in a subunit, Cur_Unit
6089 -- is still the parent, and in that case the redundant one
6090 -- is the one appearing in the subunit.
6092 if Nkind (Unit (Cunit (New_Unit))) = N_Subunit then
6093 Redundant := Clause;
6094 Prev_Use := Cur_Use;
6096 -- Most common case: redundant clause in body,
6097 -- original clause in spec. Current scope is spec entity.
6102 Unit (Library_Unit (Cunit (Current_Sem_Unit))))
6104 Redundant := Cur_Use;
6108 -- The new clause may appear in an unrelated unit, when
6109 -- the parents of a generic are being installed prior to
6110 -- instantiation. In this case there must be no warning.
6111 -- We detect this case by checking whether the current top
6112 -- of the stack is related to the current compilation.
6114 Scop := Current_Scope;
6115 while Present (Scop)
6116 and then Scop /= Standard_Standard
6118 if Is_Compilation_Unit (Scop)
6119 and then not Is_Child_Unit (Scop)
6123 elsif Scop = Cunit_Entity (Current_Sem_Unit) then
6127 Scop := Scope (Scop);
6130 Redundant := Cur_Use;
6134 elsif New_Unit = Current_Sem_Unit then
6135 Redundant := Clause;
6136 Prev_Use := Cur_Use;
6139 -- Neither is the current unit, so they appear in parent or
6140 -- sibling units. Warning will be emitted elsewhere.
6146 elsif Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Declaration
6147 and then Present (Parent_Spec (Unit (Cunit (Current_Sem_Unit))))
6149 -- Use_clause is in child unit of current unit, and the child
6150 -- unit appears in the context of the body of the parent, so it
6151 -- has been installed first, even though it is the redundant one.
6152 -- Depending on their placement in the context, the visible or the
6153 -- private parts of the two units, either might appear as redundant,
6154 -- but the message has to be on the current unit.
6156 if Get_Source_Unit (Cur_Use) = Current_Sem_Unit then
6157 Redundant := Cur_Use;
6160 Redundant := Clause;
6161 Prev_Use := Cur_Use;
6164 -- If the new use clause appears in the private part of a parent unit
6165 -- it may appear to be redundant w.r.t. a use clause in a child unit,
6166 -- but the previous use clause was needed in the visible part of the
6167 -- child, and no warning should be emitted.
6169 if Nkind (Parent (Decl)) = N_Package_Specification
6171 List_Containing (Decl) = Private_Declarations (Parent (Decl))
6174 Par : constant Entity_Id := Defining_Entity (Parent (Decl));
6175 Spec : constant Node_Id :=
6176 Specification (Unit (Cunit (Current_Sem_Unit)));
6179 if Is_Compilation_Unit (Par)
6180 and then Par /= Cunit_Entity (Current_Sem_Unit)
6181 and then Parent (Cur_Use) = Spec
6183 List_Containing (Cur_Use) = Visible_Declarations (Spec)
6190 -- Finally, if the current use clause is in the context then
6191 -- the clause is redundant when it is nested within the unit.
6193 elsif Nkind (Parent (Cur_Use)) = N_Compilation_Unit
6194 and then Nkind (Parent (Parent (Clause))) /= N_Compilation_Unit
6195 and then Get_Source_Unit (Cur_Use) = Get_Source_Unit (Clause)
6197 Redundant := Clause;
6198 Prev_Use := Cur_Use;
6204 if Present (Redundant) then
6205 Error_Msg_Sloc := Sloc (Prev_Use);
6207 ("& is already use-visible through previous use clause #?",
6208 Redundant, Pack_Name);
6210 end Note_Redundant_Use;
6216 procedure Pop_Scope is
6217 SST : Scope_Stack_Entry renames Scope_Stack.Table (Scope_Stack.Last);
6220 if Debug_Flag_E then
6224 Scope_Suppress := SST.Save_Scope_Suppress;
6225 Local_Suppress_Stack_Top := SST.Save_Local_Suppress_Stack_Top;
6226 Check_Policy_List := SST.Save_Check_Policy_List;
6228 if Debug_Flag_W then
6229 Write_Str ("--> exiting scope: ");
6230 Write_Name (Chars (Current_Scope));
6231 Write_Str (", Depth=");
6232 Write_Int (Int (Scope_Stack.Last));
6236 End_Use_Clauses (SST.First_Use_Clause);
6238 -- If the actions to be wrapped are still there they will get lost
6239 -- causing incomplete code to be generated. It is better to abort in
6240 -- this case (and we do the abort even with assertions off since the
6241 -- penalty is incorrect code generation)
6243 if SST.Actions_To_Be_Wrapped_Before /= No_List
6245 SST.Actions_To_Be_Wrapped_After /= No_List
6250 -- Free last subprogram name if allocated, and pop scope
6252 Free (SST.Last_Subprogram_Name);
6253 Scope_Stack.Decrement_Last;
6260 procedure Push_Scope (S : Entity_Id) is
6264 if Ekind (S) = E_Void then
6267 -- Set scope depth if not a non-concurrent type, and we have not
6268 -- yet set the scope depth. This means that we have the first
6269 -- occurrence of the scope, and this is where the depth is set.
6271 elsif (not Is_Type (S) or else Is_Concurrent_Type (S))
6272 and then not Scope_Depth_Set (S)
6274 if S = Standard_Standard then
6275 Set_Scope_Depth_Value (S, Uint_0);
6277 elsif Is_Child_Unit (S) then
6278 Set_Scope_Depth_Value (S, Uint_1);
6280 elsif not Is_Record_Type (Current_Scope) then
6281 if Ekind (S) = E_Loop then
6282 Set_Scope_Depth_Value (S, Scope_Depth (Current_Scope));
6284 Set_Scope_Depth_Value (S, Scope_Depth (Current_Scope) + 1);
6289 Scope_Stack.Increment_Last;
6292 SST : Scope_Stack_Entry renames Scope_Stack.Table (Scope_Stack.Last);
6296 SST.Save_Scope_Suppress := Scope_Suppress;
6297 SST.Save_Local_Suppress_Stack_Top := Local_Suppress_Stack_Top;
6298 SST.Save_Check_Policy_List := Check_Policy_List;
6300 if Scope_Stack.Last > Scope_Stack.First then
6301 SST.Component_Alignment_Default := Scope_Stack.Table
6302 (Scope_Stack.Last - 1).
6303 Component_Alignment_Default;
6306 SST.Last_Subprogram_Name := null;
6307 SST.Is_Transient := False;
6308 SST.Node_To_Be_Wrapped := Empty;
6309 SST.Pending_Freeze_Actions := No_List;
6310 SST.Actions_To_Be_Wrapped_Before := No_List;
6311 SST.Actions_To_Be_Wrapped_After := No_List;
6312 SST.First_Use_Clause := Empty;
6313 SST.Is_Active_Stack_Base := False;
6314 SST.Previous_Visibility := False;
6317 if Debug_Flag_W then
6318 Write_Str ("--> new scope: ");
6319 Write_Name (Chars (Current_Scope));
6320 Write_Str (", Id=");
6321 Write_Int (Int (Current_Scope));
6322 Write_Str (", Depth=");
6323 Write_Int (Int (Scope_Stack.Last));
6327 -- Deal with copying flags from the previous scope to this one. This
6328 -- is not necessary if either scope is standard, or if the new scope
6331 if S /= Standard_Standard
6332 and then Scope (S) /= Standard_Standard
6333 and then not Is_Child_Unit (S)
6337 if Nkind (E) not in N_Entity then
6341 -- Copy categorization flags from Scope (S) to S, this is not done
6342 -- when Scope (S) is Standard_Standard since propagation is from
6343 -- library unit entity inwards. Copy other relevant attributes as
6344 -- well (Discard_Names in particular).
6346 -- We only propagate inwards for library level entities,
6347 -- inner level subprograms do not inherit the categorization.
6349 if Is_Library_Level_Entity (S) then
6350 Set_Is_Preelaborated (S, Is_Preelaborated (E));
6351 Set_Is_Shared_Passive (S, Is_Shared_Passive (E));
6352 Set_Discard_Names (S, Discard_Names (E));
6353 Set_Suppress_Value_Tracking_On_Call
6354 (S, Suppress_Value_Tracking_On_Call (E));
6355 Set_Categorization_From_Scope (E => S, Scop => E);
6360 ---------------------
6361 -- Premature_Usage --
6362 ---------------------
6364 procedure Premature_Usage (N : Node_Id) is
6365 Kind : constant Node_Kind := Nkind (Parent (Entity (N)));
6366 E : Entity_Id := Entity (N);
6369 -- Within an instance, the analysis of the actual for a formal object
6370 -- does not see the name of the object itself. This is significant only
6371 -- if the object is an aggregate, where its analysis does not do any
6372 -- name resolution on component associations. (see 4717-008). In such a
6373 -- case, look for the visible homonym on the chain.
6376 and then Present (Homonym (E))
6381 and then not In_Open_Scopes (Scope (E))
6388 Set_Etype (N, Etype (E));
6393 if Kind = N_Component_Declaration then
6395 ("component&! cannot be used before end of record declaration", N);
6397 elsif Kind = N_Parameter_Specification then
6399 ("formal parameter&! cannot be used before end of specification",
6402 elsif Kind = N_Discriminant_Specification then
6404 ("discriminant&! cannot be used before end of discriminant part",
6407 elsif Kind = N_Procedure_Specification
6408 or else Kind = N_Function_Specification
6411 ("subprogram&! cannot be used before end of its declaration",
6414 elsif Kind = N_Full_Type_Declaration then
6416 ("type& cannot be used before end of its declaration!", N);
6420 ("object& cannot be used before end of its declaration!", N);
6422 end Premature_Usage;
6424 ------------------------
6425 -- Present_System_Aux --
6426 ------------------------
6428 function Present_System_Aux (N : Node_Id := Empty) return Boolean is
6430 Aux_Name : Unit_Name_Type;
6431 Unum : Unit_Number_Type;
6436 function Find_System (C_Unit : Node_Id) return Entity_Id;
6437 -- Scan context clause of compilation unit to find with_clause
6444 function Find_System (C_Unit : Node_Id) return Entity_Id is
6445 With_Clause : Node_Id;
6448 With_Clause := First (Context_Items (C_Unit));
6449 while Present (With_Clause) loop
6450 if (Nkind (With_Clause) = N_With_Clause
6451 and then Chars (Name (With_Clause)) = Name_System)
6452 and then Comes_From_Source (With_Clause)
6463 -- Start of processing for Present_System_Aux
6466 -- The child unit may have been loaded and analyzed already
6468 if Present (System_Aux_Id) then
6471 -- If no previous pragma for System.Aux, nothing to load
6473 elsif No (System_Extend_Unit) then
6476 -- Use the unit name given in the pragma to retrieve the unit.
6477 -- Verify that System itself appears in the context clause of the
6478 -- current compilation. If System is not present, an error will
6479 -- have been reported already.
6482 With_Sys := Find_System (Cunit (Current_Sem_Unit));
6484 The_Unit := Unit (Cunit (Current_Sem_Unit));
6488 (Nkind (The_Unit) = N_Package_Body
6489 or else (Nkind (The_Unit) = N_Subprogram_Body
6491 not Acts_As_Spec (Cunit (Current_Sem_Unit))))
6493 With_Sys := Find_System (Library_Unit (Cunit (Current_Sem_Unit)));
6497 and then Present (N)
6499 -- If we are compiling a subunit, we need to examine its
6500 -- context as well (Current_Sem_Unit is the parent unit);
6502 The_Unit := Parent (N);
6503 while Nkind (The_Unit) /= N_Compilation_Unit loop
6504 The_Unit := Parent (The_Unit);
6507 if Nkind (Unit (The_Unit)) = N_Subunit then
6508 With_Sys := Find_System (The_Unit);
6512 if No (With_Sys) then
6516 Loc := Sloc (With_Sys);
6517 Get_Name_String (Chars (Expression (System_Extend_Unit)));
6518 Name_Buffer (8 .. Name_Len + 7) := Name_Buffer (1 .. Name_Len);
6519 Name_Buffer (1 .. 7) := "system.";
6520 Name_Buffer (Name_Len + 8) := '%';
6521 Name_Buffer (Name_Len + 9) := 's';
6522 Name_Len := Name_Len + 9;
6523 Aux_Name := Name_Find;
6527 (Load_Name => Aux_Name,
6530 Error_Node => With_Sys);
6532 if Unum /= No_Unit then
6533 Semantics (Cunit (Unum));
6535 Defining_Entity (Specification (Unit (Cunit (Unum))));
6538 Make_With_Clause (Loc,
6540 Make_Expanded_Name (Loc,
6541 Chars => Chars (System_Aux_Id),
6542 Prefix => New_Reference_To (Scope (System_Aux_Id), Loc),
6543 Selector_Name => New_Reference_To (System_Aux_Id, Loc)));
6545 Set_Entity (Name (Withn), System_Aux_Id);
6547 Set_Library_Unit (Withn, Cunit (Unum));
6548 Set_Corresponding_Spec (Withn, System_Aux_Id);
6549 Set_First_Name (Withn, True);
6550 Set_Implicit_With (Withn, True);
6552 Insert_After (With_Sys, Withn);
6553 Mark_Rewrite_Insertion (Withn);
6554 Set_Context_Installed (Withn);
6558 -- Here if unit load failed
6561 Error_Msg_Name_1 := Name_System;
6562 Error_Msg_Name_2 := Chars (Expression (System_Extend_Unit));
6564 ("extension package `%.%` does not exist",
6565 Opt.System_Extend_Unit);
6569 end Present_System_Aux;
6571 -------------------------
6572 -- Restore_Scope_Stack --
6573 -------------------------
6575 procedure Restore_Scope_Stack (Handle_Use : Boolean := True) is
6578 Comp_Unit : Node_Id;
6579 In_Child : Boolean := False;
6580 Full_Vis : Boolean := True;
6581 SS_Last : constant Int := Scope_Stack.Last;
6584 -- Restore visibility of previous scope stack, if any
6586 for J in reverse 0 .. Scope_Stack.Last loop
6587 exit when Scope_Stack.Table (J).Entity = Standard_Standard
6588 or else No (Scope_Stack.Table (J).Entity);
6590 S := Scope_Stack.Table (J).Entity;
6592 if not Is_Hidden_Open_Scope (S) then
6594 -- If the parent scope is hidden, its entities are hidden as
6595 -- well, unless the entity is the instantiation currently
6598 if not Is_Hidden_Open_Scope (Scope (S))
6599 or else not Analyzed (Parent (S))
6600 or else Scope (S) = Standard_Standard
6602 Set_Is_Immediately_Visible (S, True);
6605 E := First_Entity (S);
6606 while Present (E) loop
6607 if Is_Child_Unit (E) then
6608 Set_Is_Immediately_Visible (E,
6609 Is_Visible_Child_Unit (E) or else In_Open_Scopes (E));
6611 Set_Is_Immediately_Visible (E, True);
6616 if not Full_Vis then
6617 exit when E = First_Private_Entity (S);
6621 -- The visibility of child units (siblings of current compilation)
6622 -- must be restored in any case. Their declarations may appear
6623 -- after the private part of the parent.
6625 if not Full_Vis then
6626 while Present (E) loop
6627 if Is_Child_Unit (E) then
6628 Set_Is_Immediately_Visible (E,
6629 Is_Visible_Child_Unit (E) or else In_Open_Scopes (E));
6637 if Is_Child_Unit (S)
6638 and not In_Child -- check only for current unit
6642 -- Restore visibility of parents according to whether the child
6643 -- is private and whether we are in its visible part.
6645 Comp_Unit := Parent (Unit_Declaration_Node (S));
6647 if Nkind (Comp_Unit) = N_Compilation_Unit
6648 and then Private_Present (Comp_Unit)
6652 elsif Is_Package_Or_Generic_Package (S)
6653 and then (In_Private_Part (S)
6654 or else In_Package_Body (S))
6658 -- if S is the scope of some instance (which has already been
6659 -- seen on the stack) it does not affect the visibility of
6662 elsif Is_Hidden_Open_Scope (S) then
6665 elsif (Ekind (S) = E_Procedure
6666 or else Ekind (S) = E_Function)
6667 and then Has_Completion (S)
6678 if SS_Last >= Scope_Stack.First
6679 and then Scope_Stack.Table (SS_Last).Entity /= Standard_Standard
6682 Install_Use_Clauses (Scope_Stack.Table (SS_Last).First_Use_Clause);
6684 end Restore_Scope_Stack;
6686 ----------------------
6687 -- Save_Scope_Stack --
6688 ----------------------
6690 procedure Save_Scope_Stack (Handle_Use : Boolean := True) is
6693 SS_Last : constant Int := Scope_Stack.Last;
6696 if SS_Last >= Scope_Stack.First
6697 and then Scope_Stack.Table (SS_Last).Entity /= Standard_Standard
6700 End_Use_Clauses (Scope_Stack.Table (SS_Last).First_Use_Clause);
6703 -- If the call is from within a compilation unit, as when called from
6704 -- Rtsfind, make current entries in scope stack invisible while we
6705 -- analyze the new unit.
6707 for J in reverse 0 .. SS_Last loop
6708 exit when Scope_Stack.Table (J).Entity = Standard_Standard
6709 or else No (Scope_Stack.Table (J).Entity);
6711 S := Scope_Stack.Table (J).Entity;
6712 Set_Is_Immediately_Visible (S, False);
6714 E := First_Entity (S);
6715 while Present (E) loop
6716 Set_Is_Immediately_Visible (E, False);
6722 end Save_Scope_Stack;
6728 procedure Set_Use (L : List_Id) is
6730 Pack_Name : Node_Id;
6737 while Present (Decl) loop
6738 if Nkind (Decl) = N_Use_Package_Clause then
6739 Chain_Use_Clause (Decl);
6741 Pack_Name := First (Names (Decl));
6742 while Present (Pack_Name) loop
6743 Pack := Entity (Pack_Name);
6745 if Ekind (Pack) = E_Package
6746 and then Applicable_Use (Pack_Name)
6748 Use_One_Package (Pack, Decl);
6754 elsif Nkind (Decl) = N_Use_Type_Clause then
6755 Chain_Use_Clause (Decl);
6757 Id := First (Subtype_Marks (Decl));
6758 while Present (Id) loop
6759 if Entity (Id) /= Any_Type then
6772 ---------------------
6773 -- Use_One_Package --
6774 ---------------------
6776 procedure Use_One_Package (P : Entity_Id; N : Node_Id) is
6779 Current_Instance : Entity_Id := Empty;
6781 Private_With_OK : Boolean := False;
6784 if Ekind (P) /= E_Package then
6789 Set_Current_Use_Clause (P, N);
6791 -- Ada 2005 (AI-50217): Check restriction
6793 if From_With_Type (P) then
6794 Error_Msg_N ("limited withed package cannot appear in use clause", N);
6797 -- Find enclosing instance, if any
6800 Current_Instance := Current_Scope;
6801 while not Is_Generic_Instance (Current_Instance) loop
6802 Current_Instance := Scope (Current_Instance);
6805 if No (Hidden_By_Use_Clause (N)) then
6806 Set_Hidden_By_Use_Clause (N, New_Elmt_List);
6810 -- If unit is a package renaming, indicate that the renamed
6811 -- package is also in use (the flags on both entities must
6812 -- remain consistent, and a subsequent use of either of them
6813 -- should be recognized as redundant).
6815 if Present (Renamed_Object (P)) then
6816 Set_In_Use (Renamed_Object (P));
6817 Set_Current_Use_Clause (Renamed_Object (P), N);
6818 Real_P := Renamed_Object (P);
6823 -- Ada 2005 (AI-262): Check the use_clause of a private withed package
6824 -- found in the private part of a package specification
6826 if In_Private_Part (Current_Scope)
6827 and then Has_Private_With (P)
6828 and then Is_Child_Unit (Current_Scope)
6829 and then Is_Child_Unit (P)
6830 and then Is_Ancestor_Package (Scope (Current_Scope), P)
6832 Private_With_OK := True;
6835 -- Loop through entities in one package making them potentially
6838 Id := First_Entity (P);
6840 and then (Id /= First_Private_Entity (P)
6841 or else Private_With_OK) -- Ada 2005 (AI-262)
6843 Prev := Current_Entity (Id);
6844 while Present (Prev) loop
6845 if Is_Immediately_Visible (Prev)
6846 and then (not Is_Overloadable (Prev)
6847 or else not Is_Overloadable (Id)
6848 or else (Type_Conformant (Id, Prev)))
6850 if No (Current_Instance) then
6852 -- Potentially use-visible entity remains hidden
6854 goto Next_Usable_Entity;
6856 -- A use clause within an instance hides outer global entities,
6857 -- which are not used to resolve local entities in the
6858 -- instance. Note that the predefined entities in Standard
6859 -- could not have been hidden in the generic by a use clause,
6860 -- and therefore remain visible. Other compilation units whose
6861 -- entities appear in Standard must be hidden in an instance.
6863 -- To determine whether an entity is external to the instance
6864 -- we compare the scope depth of its scope with that of the
6865 -- current instance. However, a generic actual of a subprogram
6866 -- instance is declared in the wrapper package but will not be
6867 -- hidden by a use-visible entity.
6869 -- If Id is called Standard, the predefined package with the
6870 -- same name is in the homonym chain. It has to be ignored
6871 -- because it has no defined scope (being the only entity in
6872 -- the system with this mandated behavior).
6874 elsif not Is_Hidden (Id)
6875 and then Present (Scope (Prev))
6876 and then not Is_Wrapper_Package (Scope (Prev))
6877 and then Scope_Depth (Scope (Prev)) <
6878 Scope_Depth (Current_Instance)
6879 and then (Scope (Prev) /= Standard_Standard
6880 or else Sloc (Prev) > Standard_Location)
6882 Set_Is_Potentially_Use_Visible (Id);
6883 Set_Is_Immediately_Visible (Prev, False);
6884 Append_Elmt (Prev, Hidden_By_Use_Clause (N));
6887 -- A user-defined operator is not use-visible if the predefined
6888 -- operator for the type is immediately visible, which is the case
6889 -- if the type of the operand is in an open scope. This does not
6890 -- apply to user-defined operators that have operands of different
6891 -- types, because the predefined mixed mode operations (multiply
6892 -- and divide) apply to universal types and do not hide anything.
6894 elsif Ekind (Prev) = E_Operator
6895 and then Operator_Matches_Spec (Prev, Id)
6896 and then In_Open_Scopes
6897 (Scope (Base_Type (Etype (First_Formal (Id)))))
6898 and then (No (Next_Formal (First_Formal (Id)))
6899 or else Etype (First_Formal (Id))
6900 = Etype (Next_Formal (First_Formal (Id)))
6901 or else Chars (Prev) = Name_Op_Expon)
6903 goto Next_Usable_Entity;
6906 Prev := Homonym (Prev);
6909 -- On exit, we know entity is not hidden, unless it is private
6911 if not Is_Hidden (Id)
6912 and then ((not Is_Child_Unit (Id))
6913 or else Is_Visible_Child_Unit (Id))
6915 Set_Is_Potentially_Use_Visible (Id);
6917 if Is_Private_Type (Id)
6918 and then Present (Full_View (Id))
6920 Set_Is_Potentially_Use_Visible (Full_View (Id));
6924 <<Next_Usable_Entity>>
6928 -- Child units are also made use-visible by a use clause, but they may
6929 -- appear after all visible declarations in the parent entity list.
6931 while Present (Id) loop
6932 if Is_Child_Unit (Id)
6933 and then Is_Visible_Child_Unit (Id)
6935 Set_Is_Potentially_Use_Visible (Id);
6941 if Chars (Real_P) = Name_System
6942 and then Scope (Real_P) = Standard_Standard
6943 and then Present_System_Aux (N)
6945 Use_One_Package (System_Aux_Id, N);
6948 end Use_One_Package;
6954 procedure Use_One_Type (Id : Node_Id) is
6956 Is_Known_Used : Boolean;
6960 function Spec_Reloaded_For_Body return Boolean;
6961 -- Determine whether the compilation unit is a package body and the use
6962 -- type clause is in the spec of the same package. Even though the spec
6963 -- was analyzed first, its context is reloaded when analysing the body.
6965 ----------------------------
6966 -- Spec_Reloaded_For_Body --
6967 ----------------------------
6969 function Spec_Reloaded_For_Body return Boolean is
6971 if Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Body then
6973 Spec : constant Node_Id :=
6974 Parent (List_Containing (Parent (Id)));
6977 Nkind (Spec) = N_Package_Specification
6978 and then Corresponding_Body (Parent (Spec)) =
6979 Cunit_Entity (Current_Sem_Unit);
6984 end Spec_Reloaded_For_Body;
6986 -- Start of processing for Use_One_Type;
6989 -- It is the type determined by the subtype mark (8.4(8)) whose
6990 -- operations become potentially use-visible.
6992 T := Base_Type (Entity (Id));
6994 -- Either the type itself is used, the package where it is declared
6995 -- is in use or the entity is declared in the current package, thus
7000 or else In_Use (Scope (T))
7001 or else Scope (T) = Current_Scope;
7003 Set_Redundant_Use (Id,
7004 Is_Known_Used or else Is_Potentially_Use_Visible (T));
7006 if In_Open_Scopes (Scope (T)) then
7009 -- A limited view cannot appear in a use_type clause. However, an
7010 -- access type whose designated type is limited has the flag but
7011 -- is not itself a limited view unless we only have a limited view
7012 -- of its enclosing package.
7014 elsif From_With_Type (T)
7015 and then From_With_Type (Scope (T))
7018 ("incomplete type from limited view "
7019 & "cannot appear in use clause", Id);
7021 -- If the subtype mark designates a subtype in a different package,
7022 -- we have to check that the parent type is visible, otherwise the
7023 -- use type clause is a noop. Not clear how to do that???
7025 elsif not Redundant_Use (Id) then
7027 Set_Current_Use_Clause (T, Parent (Id));
7028 Op_List := Collect_Primitive_Operations (T);
7030 Elmt := First_Elmt (Op_List);
7031 while Present (Elmt) loop
7032 if (Nkind (Node (Elmt)) = N_Defining_Operator_Symbol
7033 or else Chars (Node (Elmt)) in Any_Operator_Name)
7034 and then not Is_Hidden (Node (Elmt))
7036 Set_Is_Potentially_Use_Visible (Node (Elmt));
7043 -- If warning on redundant constructs, check for unnecessary WITH
7045 if Warn_On_Redundant_Constructs
7046 and then Is_Known_Used
7048 -- with P; with P; use P;
7049 -- package P is package X is package body X is
7050 -- type T ... use P.T;
7052 -- The compilation unit is the body of X. GNAT first compiles the
7053 -- spec of X, then proceeds to the body. At that point P is marked
7054 -- as use visible. The analysis then reinstalls the spec along with
7055 -- its context. The use clause P.T is now recognized as redundant,
7056 -- but in the wrong context. Do not emit a warning in such cases.
7058 and then not Spec_Reloaded_For_Body
7060 -- The type already has a use clause
7063 if Present (Current_Use_Clause (T)) then
7065 Clause1 : constant Node_Id := Parent (Id);
7066 Clause2 : constant Node_Id := Current_Use_Clause (T);
7072 if Nkind (Parent (Clause1)) = N_Compilation_Unit
7073 and then Nkind (Parent (Clause2)) = N_Compilation_Unit
7075 -- There is a redundant use type clause in a child unit.
7076 -- Determine which of the units is more deeply nested.
7078 Unit1 := Defining_Entity (Unit (Parent (Clause1)));
7079 Unit2 := Defining_Entity (Unit (Parent (Clause2)));
7081 if Scope (Unit2) = Standard_Standard then
7082 Error_Msg_Sloc := Sloc (Current_Use_Clause (T));
7085 elsif Scope (Unit1) = Standard_Standard then
7086 Error_Msg_Sloc := Sloc (Id);
7090 -- Determine which is the descendant unit
7096 S1 := Scope (Unit1);
7097 S2 := Scope (Unit2);
7098 while S1 /= Standard_Standard
7099 and then S2 /= Standard_Standard
7105 if S1 = Standard_Standard then
7106 Error_Msg_Sloc := Sloc (Id);
7109 Error_Msg_Sloc := Sloc (Current_Use_Clause (T));
7116 ("& is already use-visible through previous "
7117 & "use_type_clause #?", Err_No, Id);
7120 ("& is already use-visible through previous use type "
7121 & "clause?", Id, Id);
7126 ("& is already use-visible through previous use type "
7127 & "clause?", Id, Id);
7130 -- The package where T is declared is already used
7132 elsif In_Use (Scope (T)) then
7133 Error_Msg_Sloc := Sloc (Current_Use_Clause (Scope (T)));
7135 ("& is already use-visible through package use clause #?",
7138 -- The current scope is the package where T is declared
7141 Error_Msg_Node_2 := Scope (T);
7143 ("& is already use-visible inside package &?", Id, Id);
7152 procedure Write_Info is
7153 Id : Entity_Id := First_Entity (Current_Scope);
7156 -- No point in dumping standard entities
7158 if Current_Scope = Standard_Standard then
7162 Write_Str ("========================================================");
7164 Write_Str (" Defined Entities in ");
7165 Write_Name (Chars (Current_Scope));
7167 Write_Str ("========================================================");
7171 Write_Str ("-- none --");
7175 while Present (Id) loop
7176 Write_Entity_Info (Id, " ");
7181 if Scope (Current_Scope) = Standard_Standard then
7183 -- Print information on the current unit itself
7185 Write_Entity_Info (Current_Scope, " ");
7195 procedure Write_Scopes is
7198 for J in reverse 1 .. Scope_Stack.Last loop
7199 S := Scope_Stack.Table (J).Entity;
7200 Write_Int (Int (S));
7201 Write_Str (" === ");
7202 Write_Name (Chars (S));
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