1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2009, 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_Eval; use Sem_Eval;
57 with Sem_Res; use Sem_Res;
58 with Sem_Util; use Sem_Util;
59 with Sem_Type; use Sem_Type;
60 with Stand; use Stand;
61 with Sinfo; use Sinfo;
62 with Sinfo.CN; use Sinfo.CN;
63 with Snames; use Snames;
64 with Style; use Style;
66 with Tbuild; use Tbuild;
67 with Uintp; use Uintp;
69 package body Sem_Ch8 is
71 ------------------------------------
72 -- Visibility and Name Resolution --
73 ------------------------------------
75 -- This package handles name resolution and the collection of
76 -- interpretations for overloaded names, prior to overload resolution.
78 -- Name resolution is the process that establishes a mapping between source
79 -- identifiers and the entities they denote at each point in the program.
80 -- Each entity is represented by a defining occurrence. Each identifier
81 -- that denotes an entity points to the corresponding defining occurrence.
82 -- This is the entity of the applied occurrence. Each occurrence holds
83 -- an index into the names table, where source identifiers are stored.
85 -- Each entry in the names table for an identifier or designator uses the
86 -- Info pointer to hold a link to the currently visible entity that has
87 -- this name (see subprograms Get_Name_Entity_Id and Set_Name_Entity_Id
88 -- in package Sem_Util). The visibility is initialized at the beginning of
89 -- semantic processing to make entities in package Standard immediately
90 -- visible. The visibility table is used in a more subtle way when
91 -- compiling subunits (see below).
93 -- Entities that have the same name (i.e. homonyms) are chained. In the
94 -- case of overloaded entities, this chain holds all the possible meanings
95 -- of a given identifier. The process of overload resolution uses type
96 -- information to select from this chain the unique meaning of a given
99 -- Entities are also chained in their scope, through the Next_Entity link.
100 -- As a consequence, the name space is organized as a sparse matrix, where
101 -- each row corresponds to a scope, and each column to a source identifier.
102 -- Open scopes, that is to say scopes currently being compiled, have their
103 -- corresponding rows of entities in order, innermost scope first.
105 -- The scopes of packages that are mentioned in context clauses appear in
106 -- no particular order, interspersed among open scopes. This is because
107 -- in the course of analyzing the context of a compilation, a package
108 -- declaration is first an open scope, and subsequently an element of the
109 -- context. If subunits or child units are present, a parent unit may
110 -- appear under various guises at various times in the compilation.
112 -- When the compilation of the innermost scope is complete, the entities
113 -- defined therein are no longer visible. If the scope is not a package
114 -- declaration, these entities are never visible subsequently, and can be
115 -- removed from visibility chains. If the scope is a package declaration,
116 -- its visible declarations may still be accessible. Therefore the entities
117 -- defined in such a scope are left on the visibility chains, and only
118 -- their visibility (immediately visibility or potential use-visibility)
121 -- The ordering of homonyms on their chain does not necessarily follow
122 -- the order of their corresponding scopes on the scope stack. For
123 -- example, if package P and the enclosing scope both contain entities
124 -- named E, then when compiling the package body the chain for E will
125 -- hold the global entity first, and the local one (corresponding to
126 -- the current inner scope) next. As a result, name resolution routines
127 -- do not assume any relative ordering of the homonym chains, either
128 -- for scope nesting or to order of appearance of context clauses.
130 -- When compiling a child unit, entities in the parent scope are always
131 -- immediately visible. When compiling the body of a child unit, private
132 -- entities in the parent must also be made immediately visible. There
133 -- are separate routines to make the visible and private declarations
134 -- visible at various times (see package Sem_Ch7).
136 -- +--------+ +-----+
137 -- | In use |-------->| EU1 |-------------------------->
138 -- +--------+ +-----+
140 -- +--------+ +-----+ +-----+
141 -- | Stand. |---------------->| ES1 |--------------->| ES2 |--->
142 -- +--------+ +-----+ +-----+
144 -- +---------+ | +-----+
145 -- | with'ed |------------------------------>| EW2 |--->
146 -- +---------+ | +-----+
148 -- +--------+ +-----+ +-----+
149 -- | Scope2 |---------------->| E12 |--------------->| E22 |--->
150 -- +--------+ +-----+ +-----+
152 -- +--------+ +-----+ +-----+
153 -- | Scope1 |---------------->| E11 |--------------->| E12 |--->
154 -- +--------+ +-----+ +-----+
158 -- | | with'ed |----------------------------------------->
162 -- (innermost first) | |
163 -- +----------------------------+
164 -- Names table => | Id1 | | | | Id2 |
165 -- +----------------------------+
167 -- Name resolution must deal with several syntactic forms: simple names,
168 -- qualified names, indexed names, and various forms of calls.
170 -- Each identifier points to an entry in the names table. The resolution
171 -- of a simple name consists in traversing the homonym chain, starting
172 -- from the names table. If an entry is immediately visible, it is the one
173 -- designated by the identifier. If only potentially use-visible entities
174 -- are on the chain, we must verify that they do not hide each other. If
175 -- the entity we find is overloadable, we collect all other overloadable
176 -- entities on the chain as long as they are not hidden.
178 -- To resolve expanded names, we must find the entity at the intersection
179 -- of the entity chain for the scope (the prefix) and the homonym chain
180 -- for the selector. In general, homonym chains will be much shorter than
181 -- entity chains, so it is preferable to start from the names table as
182 -- well. If the entity found is overloadable, we must collect all other
183 -- interpretations that are defined in the scope denoted by the prefix.
185 -- For records, protected types, and tasks, their local entities are
186 -- removed from visibility chains on exit from the corresponding scope.
187 -- From the outside, these entities are always accessed by selected
188 -- notation, and the entity chain for the record type, protected type,
189 -- etc. is traversed sequentially in order to find the designated entity.
191 -- The discriminants of a type and the operations of a protected type or
192 -- task are unchained on exit from the first view of the type, (such as
193 -- a private or incomplete type declaration, or a protected type speci-
194 -- fication) and re-chained when compiling the second view.
196 -- In the case of operators, we do not make operators on derived types
197 -- explicit. As a result, the notation P."+" may denote either a user-
198 -- defined function with name "+", or else an implicit declaration of the
199 -- operator "+" in package P. The resolution of expanded names always
200 -- tries to resolve an operator name as such an implicitly defined entity,
201 -- in addition to looking for explicit declarations.
203 -- All forms of names that denote entities (simple names, expanded names,
204 -- character literals in some cases) have a Entity attribute, which
205 -- identifies the entity denoted by the name.
207 ---------------------
208 -- The Scope Stack --
209 ---------------------
211 -- The Scope stack keeps track of the scopes currently been compiled.
212 -- Every entity that contains declarations (including records) is placed
213 -- on the scope stack while it is being processed, and removed at the end.
214 -- Whenever a non-package scope is exited, the entities defined therein
215 -- are removed from the visibility table, so that entities in outer scopes
216 -- become visible (see previous description). On entry to Sem, the scope
217 -- stack only contains the package Standard. As usual, subunits complicate
218 -- this picture ever so slightly.
220 -- The Rtsfind mechanism can force a call to Semantics while another
221 -- compilation is in progress. The unit retrieved by Rtsfind must be
222 -- compiled in its own context, and has no access to the visibility of
223 -- the unit currently being compiled. The procedures Save_Scope_Stack and
224 -- Restore_Scope_Stack make entities in current open scopes invisible
225 -- before compiling the retrieved unit, and restore the compilation
226 -- environment afterwards.
228 ------------------------
229 -- Compiling subunits --
230 ------------------------
232 -- Subunits must be compiled in the environment of the corresponding stub,
233 -- that is to say with the same visibility into the parent (and its
234 -- context) that is available at the point of the stub declaration, but
235 -- with the additional visibility provided by the context clause of the
236 -- subunit itself. As a result, compilation of a subunit forces compilation
237 -- of the parent (see description in lib-). At the point of the stub
238 -- declaration, Analyze is called recursively to compile the proper body of
239 -- the subunit, but without reinitializing the names table, nor the scope
240 -- stack (i.e. standard is not pushed on the stack). In this fashion the
241 -- context of the subunit is added to the context of the parent, and the
242 -- subunit is compiled in the correct environment. Note that in the course
243 -- of processing the context of a subunit, Standard will appear twice on
244 -- the scope stack: once for the parent of the subunit, and once for the
245 -- unit in the context clause being compiled. However, the two sets of
246 -- entities are not linked by homonym chains, so that the compilation of
247 -- any context unit happens in a fresh visibility environment.
249 -------------------------------
250 -- Processing of USE Clauses --
251 -------------------------------
253 -- Every defining occurrence has a flag indicating if it is potentially use
254 -- visible. Resolution of simple names examines this flag. The processing
255 -- of use clauses consists in setting this flag on all visible entities
256 -- defined in the corresponding package. On exit from the scope of the use
257 -- clause, the corresponding flag must be reset. However, a package may
258 -- appear in several nested use clauses (pathological but legal, alas!)
259 -- which forces us to use a slightly more involved scheme:
261 -- a) The defining occurrence for a package holds a flag -In_Use- to
262 -- indicate that it is currently in the scope of a use clause. If a
263 -- redundant use clause is encountered, then the corresponding occurrence
264 -- of the package name is flagged -Redundant_Use-.
266 -- b) On exit from a scope, the use clauses in its declarative part are
267 -- scanned. The visibility flag is reset in all entities declared in
268 -- package named in a use clause, as long as the package is not flagged
269 -- as being in a redundant use clause (in which case the outer use
270 -- clause is still in effect, and the direct visibility of its entities
271 -- must be retained).
273 -- Note that entities are not removed from their homonym chains on exit
274 -- from the package specification. A subsequent use clause does not need
275 -- to rechain the visible entities, but only to establish their direct
278 -----------------------------------
279 -- Handling private declarations --
280 -----------------------------------
282 -- The principle that each entity has a single defining occurrence clashes
283 -- with the presence of two separate definitions for private types: the
284 -- first is the private type declaration, and second is the full type
285 -- declaration. It is important that all references to the type point to
286 -- the same defining occurrence, namely the first one. To enforce the two
287 -- separate views of the entity, the corresponding information is swapped
288 -- between the two declarations. Outside of the package, the defining
289 -- occurrence only contains the private declaration information, while in
290 -- the private part and the body of the package the defining occurrence
291 -- contains the full declaration. To simplify the swap, the defining
292 -- occurrence that currently holds the private declaration points to the
293 -- full declaration. During semantic processing the defining occurrence
294 -- also points to a list of private dependents, that is to say access types
295 -- or composite types whose designated types or component types are
296 -- subtypes or derived types of the private type in question. After the
297 -- full declaration has been seen, the private dependents are updated to
298 -- indicate that they have full definitions.
300 ------------------------------------
301 -- Handling of Undefined Messages --
302 ------------------------------------
304 -- In normal mode, only the first use of an undefined identifier generates
305 -- a message. The table Urefs is used to record error messages that have
306 -- been issued so that second and subsequent ones do not generate further
307 -- messages. However, the second reference causes text to be added to the
308 -- original undefined message noting "(more references follow)". The
309 -- full error list option (-gnatf) forces messages to be generated for
310 -- every reference and disconnects the use of this table.
312 type Uref_Entry is record
314 -- Node for identifier for which original message was posted. The
315 -- Chars field of this identifier is used to detect later references
316 -- to the same identifier.
319 -- Records error message Id of original undefined message. Reset to
320 -- No_Error_Msg after the second occurrence, where it is used to add
321 -- text to the original message as described above.
324 -- Set if the message is not visible rather than undefined
327 -- Records location of error message. Used to make sure that we do
328 -- not consider a, b : undefined as two separate instances, which
329 -- would otherwise happen, since the parser converts this sequence
330 -- to a : undefined; b : undefined.
334 package Urefs is new Table.Table (
335 Table_Component_Type => Uref_Entry,
336 Table_Index_Type => Nat,
337 Table_Low_Bound => 1,
339 Table_Increment => 100,
340 Table_Name => "Urefs");
342 Candidate_Renaming : Entity_Id;
343 -- Holds a candidate interpretation that appears in a subprogram renaming
344 -- declaration and does not match the given specification, but matches at
345 -- least on the first formal. Allows better error message when given
346 -- specification omits defaulted parameters, a common error.
348 -----------------------
349 -- Local Subprograms --
350 -----------------------
352 procedure Analyze_Generic_Renaming
355 -- Common processing for all three kinds of generic renaming declarations.
356 -- Enter new name and indicate that it renames the generic unit.
358 procedure Analyze_Renamed_Character
362 -- Renamed entity is given by a character literal, which must belong
363 -- to the return type of the new entity. Is_Body indicates whether the
364 -- declaration is a renaming_as_body. If the original declaration has
365 -- already been frozen (because of an intervening body, e.g.) the body of
366 -- the function must be built now. The same applies to the following
367 -- various renaming procedures.
369 procedure Analyze_Renamed_Dereference
373 -- Renamed entity is given by an explicit dereference. Prefix must be a
374 -- conformant access_to_subprogram type.
376 procedure Analyze_Renamed_Entry
380 -- If the renamed entity in a subprogram renaming is an entry or protected
381 -- subprogram, build a body for the new entity whose only statement is a
382 -- call to the renamed entity.
384 procedure Analyze_Renamed_Family_Member
388 -- Used when the renamed entity is an indexed component. The prefix must
389 -- denote an entry family.
391 procedure Analyze_Renamed_Primitive_Operation
395 -- If the renamed entity in a subprogram renaming is a primitive operation
396 -- or a class-wide operation in prefix form, save the target object, which
397 -- must be added to the list of actuals in any subsequent call.
399 function Applicable_Use (Pack_Name : Node_Id) return Boolean;
400 -- Common code to Use_One_Package and Set_Use, to determine whether
401 -- use clause must be processed. Pack_Name is an entity name that
402 -- references the package in question.
404 procedure Attribute_Renaming (N : Node_Id);
405 -- Analyze renaming of attribute as function. The renaming declaration N
406 -- is rewritten as a function body that returns the attribute reference
407 -- applied to the formals of the function.
409 procedure Check_Frozen_Renaming (N : Node_Id; Subp : Entity_Id);
410 -- A renaming_as_body may occur after the entity of the original decla-
411 -- ration has been frozen. In that case, the body of the new entity must
412 -- be built now, because the usual mechanism of building the renamed
413 -- body at the point of freezing will not work. Subp is the subprogram
414 -- for which N provides the Renaming_As_Body.
416 procedure Check_In_Previous_With_Clause
419 -- N is a use_package clause and Nam the package name, or N is a use_type
420 -- clause and Nam is the prefix of the type name. In either case, verify
421 -- that the package is visible at that point in the context: either it
422 -- appears in a previous with_clause, or because it is a fully qualified
423 -- name and the root ancestor appears in a previous with_clause.
425 procedure Check_Library_Unit_Renaming (N : Node_Id; Old_E : Entity_Id);
426 -- Verify that the entity in a renaming declaration that is a library unit
427 -- is itself a library unit and not a nested unit or subunit. Also check
428 -- that if the renaming is a child unit of a generic parent, then the
429 -- renamed unit must also be a child unit of that parent. Finally, verify
430 -- that a renamed generic unit is not an implicit child declared within
431 -- an instance of the parent.
433 procedure Chain_Use_Clause (N : Node_Id);
434 -- Chain use clause onto list of uses clauses headed by First_Use_Clause in
435 -- the proper scope table entry. This is usually the current scope, but it
436 -- will be an inner scope when installing the use clauses of the private
437 -- declarations of a parent unit prior to compiling the private part of a
438 -- child unit. This chain is traversed when installing/removing use clauses
439 -- when compiling a subunit or instantiating a generic body on the fly,
440 -- when it is necessary to save and restore full environments.
442 function Has_Implicit_Character_Literal (N : Node_Id) return Boolean;
443 -- Find a type derived from Character or Wide_Character in the prefix of N.
444 -- Used to resolved qualified names whose selector is a character literal.
446 function Has_Private_With (E : Entity_Id) return Boolean;
447 -- Ada 2005 (AI-262): Determines if the current compilation unit has a
448 -- private with on E.
450 procedure Find_Expanded_Name (N : Node_Id);
451 -- Selected component is known to be expanded name. Verify legality
452 -- of selector given the scope denoted by prefix.
454 function Find_Renamed_Entity
458 Is_Actual : Boolean := False) return Entity_Id;
459 -- Find the renamed entity that corresponds to the given parameter profile
460 -- in a subprogram renaming declaration. The renamed entity may be an
461 -- operator, a subprogram, an entry, or a protected operation. Is_Actual
462 -- indicates that the renaming is the one generated for an actual subpro-
463 -- gram in an instance, for which special visibility checks apply.
465 function Has_Implicit_Operator (N : Node_Id) return Boolean;
466 -- N is an expanded name whose selector is an operator name (e.g. P."+").
467 -- declarative part contains an implicit declaration of an operator if it
468 -- has a declaration of a type to which one of the predefined operators
469 -- apply. The existence of this routine is an implementation artifact. A
470 -- more straightforward but more space-consuming choice would be to make
471 -- all inherited operators explicit in the symbol table.
473 procedure Inherit_Renamed_Profile (New_S : Entity_Id; Old_S : Entity_Id);
474 -- A subprogram defined by a renaming declaration inherits the parameter
475 -- profile of the renamed entity. The subtypes given in the subprogram
476 -- specification are discarded and replaced with those of the renamed
477 -- subprogram, which are then used to recheck the default values.
479 function Is_Appropriate_For_Record (T : Entity_Id) return Boolean;
480 -- Prefix is appropriate for record if it is of a record type, or an access
483 function Is_Appropriate_For_Entry_Prefix (T : Entity_Id) return Boolean;
484 -- True if it is of a task type, a protected type, or else an access to one
487 procedure Note_Redundant_Use (Clause : Node_Id);
488 -- Mark the name in a use clause as redundant if the corresponding entity
489 -- is already use-visible. Emit a warning if the use clause comes from
490 -- source and the proper warnings are enabled.
492 procedure Premature_Usage (N : Node_Id);
493 -- Diagnose usage of an entity before it is visible
495 procedure Use_One_Package (P : Entity_Id; N : Node_Id);
496 -- Make visible entities declared in package P potentially use-visible
497 -- in the current context. Also used in the analysis of subunits, when
498 -- re-installing use clauses of parent units. N is the use_clause that
499 -- names P (and possibly other packages).
501 procedure Use_One_Type (Id : Node_Id);
502 -- Id is the subtype mark from a use type clause. This procedure makes
503 -- the primitive operators of the type potentially use-visible.
505 procedure Write_Info;
506 -- Write debugging information on entities declared in current scope
508 procedure Write_Scopes;
509 pragma Warnings (Off, Write_Scopes);
510 -- Debugging information: dump all entities on scope stack
512 --------------------------------
513 -- Analyze_Exception_Renaming --
514 --------------------------------
516 -- The language only allows a single identifier, but the tree holds an
517 -- identifier list. The parser has already issued an error message if
518 -- there is more than one element in the list.
520 procedure Analyze_Exception_Renaming (N : Node_Id) is
521 Id : constant Node_Id := Defining_Identifier (N);
522 Nam : constant Node_Id := Name (N);
528 Set_Ekind (Id, E_Exception);
529 Set_Exception_Code (Id, Uint_0);
530 Set_Etype (Id, Standard_Exception_Type);
531 Set_Is_Pure (Id, Is_Pure (Current_Scope));
533 if not Is_Entity_Name (Nam) or else
534 Ekind (Entity (Nam)) /= E_Exception
536 Error_Msg_N ("invalid exception name in renaming", Nam);
538 if Present (Renamed_Object (Entity (Nam))) then
539 Set_Renamed_Object (Id, Renamed_Object (Entity (Nam)));
541 Set_Renamed_Object (Id, Entity (Nam));
544 end Analyze_Exception_Renaming;
546 ---------------------------
547 -- Analyze_Expanded_Name --
548 ---------------------------
550 procedure Analyze_Expanded_Name (N : Node_Id) is
552 -- If the entity pointer is already set, this is an internal node, or a
553 -- node that is analyzed more than once, after a tree modification. In
554 -- such a case there is no resolution to perform, just set the type. For
555 -- completeness, analyze prefix as well.
557 if Present (Entity (N)) then
558 if Is_Type (Entity (N)) then
559 Set_Etype (N, Entity (N));
561 Set_Etype (N, Etype (Entity (N)));
564 Analyze (Prefix (N));
567 Find_Expanded_Name (N);
569 end Analyze_Expanded_Name;
571 ---------------------------------------
572 -- Analyze_Generic_Function_Renaming --
573 ---------------------------------------
575 procedure Analyze_Generic_Function_Renaming (N : Node_Id) is
577 Analyze_Generic_Renaming (N, E_Generic_Function);
578 end Analyze_Generic_Function_Renaming;
580 --------------------------------------
581 -- Analyze_Generic_Package_Renaming --
582 --------------------------------------
584 procedure Analyze_Generic_Package_Renaming (N : Node_Id) is
586 -- Apply the Text_IO Kludge here, since we may be renaming one of the
587 -- subpackages of Text_IO, then join common routine.
589 Text_IO_Kludge (Name (N));
591 Analyze_Generic_Renaming (N, E_Generic_Package);
592 end Analyze_Generic_Package_Renaming;
594 ----------------------------------------
595 -- Analyze_Generic_Procedure_Renaming --
596 ----------------------------------------
598 procedure Analyze_Generic_Procedure_Renaming (N : Node_Id) is
600 Analyze_Generic_Renaming (N, E_Generic_Procedure);
601 end Analyze_Generic_Procedure_Renaming;
603 ------------------------------
604 -- Analyze_Generic_Renaming --
605 ------------------------------
607 procedure Analyze_Generic_Renaming
611 New_P : constant Entity_Id := Defining_Entity (N);
613 Inst : Boolean := False; -- prevent junk warning
616 if Name (N) = Error then
620 Generate_Definition (New_P);
622 if Current_Scope /= Standard_Standard then
623 Set_Is_Pure (New_P, Is_Pure (Current_Scope));
626 if Nkind (Name (N)) = N_Selected_Component then
627 Check_Generic_Child_Unit (Name (N), Inst);
632 if not Is_Entity_Name (Name (N)) then
633 Error_Msg_N ("expect entity name in renaming declaration", Name (N));
636 Old_P := Entity (Name (N));
640 Set_Ekind (New_P, K);
642 if Etype (Old_P) = Any_Type then
645 elsif Ekind (Old_P) /= K then
646 Error_Msg_N ("invalid generic unit name", Name (N));
649 if Present (Renamed_Object (Old_P)) then
650 Set_Renamed_Object (New_P, Renamed_Object (Old_P));
652 Set_Renamed_Object (New_P, Old_P);
655 Set_Is_Pure (New_P, Is_Pure (Old_P));
656 Set_Is_Preelaborated (New_P, Is_Preelaborated (Old_P));
658 Set_Etype (New_P, Etype (Old_P));
659 Set_Has_Completion (New_P);
661 if In_Open_Scopes (Old_P) then
662 Error_Msg_N ("within its scope, generic denotes its instance", N);
665 Check_Library_Unit_Renaming (N, Old_P);
667 end Analyze_Generic_Renaming;
669 -----------------------------
670 -- Analyze_Object_Renaming --
671 -----------------------------
673 procedure Analyze_Object_Renaming (N : Node_Id) is
674 Id : constant Entity_Id := Defining_Identifier (N);
676 Nam : constant Node_Id := Name (N);
680 function In_Generic_Scope (E : Entity_Id) return Boolean;
681 -- Determine whether entity E is inside a generic cope
683 ----------------------
684 -- In_Generic_Scope --
685 ----------------------
687 function In_Generic_Scope (E : Entity_Id) return Boolean is
692 while Present (S) and then S /= Standard_Standard loop
693 if Is_Generic_Unit (S) then
701 end In_Generic_Scope;
703 -- Start of processing for Analyze_Object_Renaming
710 Set_Is_Pure (Id, Is_Pure (Current_Scope));
713 -- The renaming of a component that depends on a discriminant requires
714 -- an actual subtype, because in subsequent use of the object Gigi will
715 -- be unable to locate the actual bounds. This explicit step is required
716 -- when the renaming is generated in removing side effects of an
717 -- already-analyzed expression.
719 if Nkind (Nam) = N_Selected_Component
720 and then Analyzed (Nam)
723 Dec := Build_Actual_Subtype_Of_Component (Etype (Nam), Nam);
725 if Present (Dec) then
726 Insert_Action (N, Dec);
727 T := Defining_Identifier (Dec);
731 -- Complete analysis of the subtype mark in any case, for ASIS use
733 if Present (Subtype_Mark (N)) then
734 Find_Type (Subtype_Mark (N));
737 elsif Present (Subtype_Mark (N)) then
738 Find_Type (Subtype_Mark (N));
739 T := Entity (Subtype_Mark (N));
742 if Nkind (Nam) = N_Type_Conversion
743 and then not Is_Tagged_Type (T)
746 ("renaming of conversion only allowed for tagged types", Nam);
751 -- Check that a class-wide object is not being renamed as an object
752 -- of a specific type. The test for access types is needed to exclude
753 -- cases where the renamed object is a dynamically tagged access
754 -- result, such as occurs in certain expansions.
756 if (Is_Class_Wide_Type (Etype (Nam))
757 or else (Is_Dynamically_Tagged (Nam)
758 and then not Is_Access_Type (T)))
759 and then not Is_Class_Wide_Type (T)
761 Error_Msg_N ("dynamically tagged expression not allowed!", Nam);
764 -- Ada 2005 (AI-230/AI-254): Access renaming
766 else pragma Assert (Present (Access_Definition (N)));
767 T := Access_Definition
769 N => Access_Definition (N));
773 -- Ada 2005 AI05-105: if the declaration has an anonymous access
774 -- type, the renamed object must also have an anonymous type, and
775 -- this is a name resolution rule. This was implicit in the last
776 -- part of the first sentence in 8.5.1.(3/2), and is made explicit
777 -- by this recent AI.
779 if not Is_Overloaded (Nam) then
780 if Ekind (Etype (Nam)) /= Ekind (T) then
782 ("expect anonymous access type in object renaming", N);
788 Typ : Entity_Id := Empty;
791 Get_First_Interp (Nam, I, It);
792 while Present (It.Typ) loop
794 if Ekind (It.Typ) = Ekind (T)
795 and then Covers (T, It.Typ)
798 Set_Etype (Nam, Typ);
799 Set_Is_Overloaded (Nam, False);
802 Error_Msg_N ("ambiguous expression in renaming", N);
805 Get_Next_Interp (I, It);
812 -- Ada 2005 (AI-231): "In the case where the type is defined by an
813 -- access_definition, the renamed entity shall be of an access-to-
814 -- constant type if and only if the access_definition defines an
815 -- access-to-constant type" ARM 8.5.1(4)
817 if Constant_Present (Access_Definition (N))
818 and then not Is_Access_Constant (Etype (Nam))
820 Error_Msg_N ("(Ada 2005): the renamed object is not "
821 & "access-to-constant (RM 8.5.1(6))", N);
823 elsif not Constant_Present (Access_Definition (N))
824 and then Is_Access_Constant (Etype (Nam))
826 Error_Msg_N ("(Ada 2005): the renamed object is not "
827 & "access-to-variable (RM 8.5.1(6))", N);
830 if Is_Access_Subprogram_Type (Etype (Nam)) then
831 Check_Subtype_Conformant
832 (Designated_Type (T), Designated_Type (Etype (Nam)));
834 elsif not Subtypes_Statically_Match
835 (Designated_Type (T), Designated_Type (Etype (Nam)))
838 ("subtype of renamed object does not statically match", N);
842 -- Special processing for renaming function return object
844 if Nkind (Nam) = N_Function_Call
845 and then Comes_From_Source (Nam)
849 -- Usage is illegal in Ada 83
853 ("(Ada 83) cannot rename function return object", Nam);
855 -- In Ada 95, warn for odd case of renaming parameterless function
856 -- call if this is not a limited type (where this is useful)
859 if Warn_On_Object_Renames_Function
860 and then No (Parameter_Associations (Nam))
861 and then not Is_Limited_Type (Etype (Nam))
864 ("?renaming function result object is suspicious",
867 ("\?function & will be called only once",
868 Nam, Entity (Name (Nam)));
870 ("\?suggest using an initialized constant object instead",
876 -- An object renaming requires an exact match of the type. Class-wide
877 -- matching is not allowed.
879 if Is_Class_Wide_Type (T)
880 and then Base_Type (Etype (Nam)) /= Base_Type (T)
887 -- (Ada 2005: AI-326): Handle wrong use of incomplete type
889 if Nkind (Nam) = N_Explicit_Dereference
890 and then Ekind (Etype (T2)) = E_Incomplete_Type
892 Error_Msg_NE ("invalid use of incomplete type&", Id, T2);
894 elsif Ekind (Etype (T)) = E_Incomplete_Type then
895 Error_Msg_NE ("invalid use of incomplete type&", Id, T);
901 if Ada_Version >= Ada_05
902 and then Nkind (Nam) = N_Attribute_Reference
903 and then Attribute_Name (Nam) = Name_Priority
907 elsif Ada_Version >= Ada_05
908 and then Nkind (Nam) in N_Has_Entity
915 if Nkind (Nam) = N_Attribute_Reference then
916 Nam_Ent := Entity (Prefix (Nam));
918 Nam_Ent := Entity (Nam);
921 Nam_Decl := Parent (Nam_Ent);
923 if Has_Null_Exclusion (N)
924 and then not Has_Null_Exclusion (Nam_Decl)
926 -- Ada 2005 (AI-423): If the object name denotes a generic
927 -- formal object of a generic unit G, and the object renaming
928 -- declaration occurs within the body of G or within the body
929 -- of a generic unit declared within the declarative region
930 -- of G, then the declaration of the formal object of G must
931 -- have a null exclusion.
933 if Is_Formal_Object (Nam_Ent)
934 and then In_Generic_Scope (Id)
937 ("renamed formal does not exclude `NULL` "
938 & "(RM 8.5.1(4.6/2))", N);
940 -- Ada 2005 (AI-423): Otherwise, the subtype of the object name
941 -- shall exclude null.
943 elsif not Can_Never_Be_Null (Etype (Nam_Ent)) then
945 ("renamed object does not exclude `NULL` "
946 & "(RM 8.5.1(4.6/2))", N);
948 elsif Can_Never_Be_Null (Etype (Nam_Ent)) then
950 ("`NOT NULL` not allowed (type of& already excludes null)",
955 elsif Has_Null_Exclusion (N)
956 and then No (Access_Definition (N))
957 and then Can_Never_Be_Null (T)
960 ("`NOT NULL` not allowed (& already excludes null)", N, T);
965 Set_Ekind (Id, E_Variable);
966 Init_Size_Align (Id);
968 if T = Any_Type or else Etype (Nam) = Any_Type then
971 -- Verify that the renamed entity is an object or a function call. It
972 -- may have been rewritten in several ways.
974 elsif Is_Object_Reference (Nam) then
975 if Comes_From_Source (N)
976 and then Is_Dependent_Component_Of_Mutable_Object (Nam)
979 ("illegal renaming of discriminant-dependent component", Nam);
984 -- A static function call may have been folded into a literal
986 elsif Nkind (Original_Node (Nam)) = N_Function_Call
988 -- When expansion is disabled, attribute reference is not
989 -- rewritten as function call. Otherwise it may be rewritten
990 -- as a conversion, so check original node.
992 or else (Nkind (Original_Node (Nam)) = N_Attribute_Reference
993 and then Is_Function_Attribute_Name
994 (Attribute_Name (Original_Node (Nam))))
996 -- Weird but legal, equivalent to renaming a function call.
997 -- Illegal if the literal is the result of constant-folding an
998 -- attribute reference that is not a function.
1000 or else (Is_Entity_Name (Nam)
1001 and then Ekind (Entity (Nam)) = E_Enumeration_Literal
1003 Nkind (Original_Node (Nam)) /= N_Attribute_Reference)
1005 or else (Nkind (Nam) = N_Type_Conversion
1006 and then Is_Tagged_Type (Entity (Subtype_Mark (Nam))))
1010 elsif Nkind (Nam) = N_Type_Conversion then
1012 ("renaming of conversion only allowed for tagged types", Nam);
1014 -- Ada 2005 (AI-327)
1016 elsif Ada_Version >= Ada_05
1017 and then Nkind (Nam) = N_Attribute_Reference
1018 and then Attribute_Name (Nam) = Name_Priority
1022 -- Allow internally generated x'Reference expression
1024 elsif Nkind (Nam) = N_Reference then
1028 Error_Msg_N ("expect object name in renaming", Nam);
1033 if not Is_Variable (Nam) then
1034 Set_Ekind (Id, E_Constant);
1035 Set_Never_Set_In_Source (Id, True);
1036 Set_Is_True_Constant (Id, True);
1039 Set_Renamed_Object (Id, Nam);
1040 end Analyze_Object_Renaming;
1042 ------------------------------
1043 -- Analyze_Package_Renaming --
1044 ------------------------------
1046 procedure Analyze_Package_Renaming (N : Node_Id) is
1047 New_P : constant Entity_Id := Defining_Entity (N);
1052 if Name (N) = Error then
1056 -- Apply Text_IO kludge here, since we may be renaming one of the
1057 -- children of Text_IO.
1059 Text_IO_Kludge (Name (N));
1061 if Current_Scope /= Standard_Standard then
1062 Set_Is_Pure (New_P, Is_Pure (Current_Scope));
1068 if Is_Entity_Name (Name (N)) then
1069 Old_P := Entity (Name (N));
1074 if Etype (Old_P) = Any_Type then
1076 ("expect package name in renaming", Name (N));
1078 elsif Ekind (Old_P) /= E_Package
1079 and then not (Ekind (Old_P) = E_Generic_Package
1080 and then In_Open_Scopes (Old_P))
1082 if Ekind (Old_P) = E_Generic_Package then
1084 ("generic package cannot be renamed as a package", Name (N));
1086 Error_Msg_Sloc := Sloc (Old_P);
1088 ("expect package name in renaming, found& declared#",
1092 -- Set basic attributes to minimize cascaded errors
1094 Set_Ekind (New_P, E_Package);
1095 Set_Etype (New_P, Standard_Void_Type);
1097 -- Here for OK package renaming
1100 -- Entities in the old package are accessible through the renaming
1101 -- entity. The simplest implementation is to have both packages share
1104 Set_Ekind (New_P, E_Package);
1105 Set_Etype (New_P, Standard_Void_Type);
1107 if Present (Renamed_Object (Old_P)) then
1108 Set_Renamed_Object (New_P, Renamed_Object (Old_P));
1110 Set_Renamed_Object (New_P, Old_P);
1113 Set_Has_Completion (New_P);
1115 Set_First_Entity (New_P, First_Entity (Old_P));
1116 Set_Last_Entity (New_P, Last_Entity (Old_P));
1117 Set_First_Private_Entity (New_P, First_Private_Entity (Old_P));
1118 Check_Library_Unit_Renaming (N, Old_P);
1119 Generate_Reference (Old_P, Name (N));
1121 -- If the renaming is in the visible part of a package, then we set
1122 -- Renamed_In_Spec for the renamed package, to prevent giving
1123 -- warnings about no entities referenced. Such a warning would be
1124 -- overenthusiastic, since clients can see entities in the renamed
1125 -- package via the visible package renaming.
1128 Ent : constant Entity_Id := Cunit_Entity (Current_Sem_Unit);
1130 if Ekind (Ent) = E_Package
1131 and then not In_Private_Part (Ent)
1132 and then In_Extended_Main_Source_Unit (N)
1133 and then Ekind (Old_P) = E_Package
1135 Set_Renamed_In_Spec (Old_P);
1139 -- If this is the renaming declaration of a package instantiation
1140 -- within itself, it is the declaration that ends the list of actuals
1141 -- for the instantiation. At this point, the subtypes that rename
1142 -- the actuals are flagged as generic, to avoid spurious ambiguities
1143 -- if the actuals for two distinct formals happen to coincide. If
1144 -- the actual is a private type, the subtype has a private completion
1145 -- that is flagged in the same fashion.
1147 -- Resolution is identical to what is was in the original generic.
1148 -- On exit from the generic instance, these are turned into regular
1149 -- subtypes again, so they are compatible with types in their class.
1151 if not Is_Generic_Instance (Old_P) then
1154 Spec := Specification (Unit_Declaration_Node (Old_P));
1157 if Nkind (Spec) = N_Package_Specification
1158 and then Present (Generic_Parent (Spec))
1159 and then Old_P = Current_Scope
1160 and then Chars (New_P) = Chars (Generic_Parent (Spec))
1166 E := First_Entity (Old_P);
1171 and then Nkind (Parent (E)) = N_Subtype_Declaration
1173 Set_Is_Generic_Actual_Type (E);
1175 if Is_Private_Type (E)
1176 and then Present (Full_View (E))
1178 Set_Is_Generic_Actual_Type (Full_View (E));
1187 end Analyze_Package_Renaming;
1189 -------------------------------
1190 -- Analyze_Renamed_Character --
1191 -------------------------------
1193 procedure Analyze_Renamed_Character
1198 C : constant Node_Id := Name (N);
1201 if Ekind (New_S) = E_Function then
1202 Resolve (C, Etype (New_S));
1205 Check_Frozen_Renaming (N, New_S);
1209 Error_Msg_N ("character literal can only be renamed as function", N);
1211 end Analyze_Renamed_Character;
1213 ---------------------------------
1214 -- Analyze_Renamed_Dereference --
1215 ---------------------------------
1217 procedure Analyze_Renamed_Dereference
1222 Nam : constant Node_Id := Name (N);
1223 P : constant Node_Id := Prefix (Nam);
1229 if not Is_Overloaded (P) then
1230 if Ekind (Etype (Nam)) /= E_Subprogram_Type
1231 or else not Type_Conformant (Etype (Nam), New_S) then
1232 Error_Msg_N ("designated type does not match specification", P);
1241 Get_First_Interp (Nam, Ind, It);
1243 while Present (It.Nam) loop
1245 if Ekind (It.Nam) = E_Subprogram_Type
1246 and then Type_Conformant (It.Nam, New_S) then
1248 if Typ /= Any_Id then
1249 Error_Msg_N ("ambiguous renaming", P);
1256 Get_Next_Interp (Ind, It);
1259 if Typ = Any_Type then
1260 Error_Msg_N ("designated type does not match specification", P);
1265 Check_Frozen_Renaming (N, New_S);
1269 end Analyze_Renamed_Dereference;
1271 ---------------------------
1272 -- Analyze_Renamed_Entry --
1273 ---------------------------
1275 procedure Analyze_Renamed_Entry
1280 Nam : constant Node_Id := Name (N);
1281 Sel : constant Node_Id := Selector_Name (Nam);
1285 if Entity (Sel) = Any_Id then
1287 -- Selector is undefined on prefix. Error emitted already
1289 Set_Has_Completion (New_S);
1293 -- Otherwise find renamed entity and build body of New_S as a call to it
1295 Old_S := Find_Renamed_Entity (N, Selector_Name (Nam), New_S);
1297 if Old_S = Any_Id then
1298 Error_Msg_N (" no subprogram or entry matches specification", N);
1301 Check_Subtype_Conformant (New_S, Old_S, N);
1302 Generate_Reference (New_S, Defining_Entity (N), 'b');
1303 Style.Check_Identifier (Defining_Entity (N), New_S);
1306 -- Only mode conformance required for a renaming_as_declaration
1308 Check_Mode_Conformant (New_S, Old_S, N);
1311 Inherit_Renamed_Profile (New_S, Old_S);
1313 -- The prefix can be an arbitrary expression that yields a task
1314 -- type, so it must be resolved.
1316 Resolve (Prefix (Nam), Scope (Old_S));
1319 Set_Convention (New_S, Convention (Old_S));
1320 Set_Has_Completion (New_S, Inside_A_Generic);
1323 Check_Frozen_Renaming (N, New_S);
1325 end Analyze_Renamed_Entry;
1327 -----------------------------------
1328 -- Analyze_Renamed_Family_Member --
1329 -----------------------------------
1331 procedure Analyze_Renamed_Family_Member
1336 Nam : constant Node_Id := Name (N);
1337 P : constant Node_Id := Prefix (Nam);
1341 if (Is_Entity_Name (P) and then Ekind (Entity (P)) = E_Entry_Family)
1342 or else (Nkind (P) = N_Selected_Component
1344 Ekind (Entity (Selector_Name (P))) = E_Entry_Family)
1346 if Is_Entity_Name (P) then
1347 Old_S := Entity (P);
1349 Old_S := Entity (Selector_Name (P));
1352 if not Entity_Matches_Spec (Old_S, New_S) then
1353 Error_Msg_N ("entry family does not match specification", N);
1356 Check_Subtype_Conformant (New_S, Old_S, N);
1357 Generate_Reference (New_S, Defining_Entity (N), 'b');
1358 Style.Check_Identifier (Defining_Entity (N), New_S);
1362 Error_Msg_N ("no entry family matches specification", N);
1365 Set_Has_Completion (New_S, Inside_A_Generic);
1368 Check_Frozen_Renaming (N, New_S);
1370 end Analyze_Renamed_Family_Member;
1372 -----------------------------------------
1373 -- Analyze_Renamed_Primitive_Operation --
1374 -----------------------------------------
1376 procedure Analyze_Renamed_Primitive_Operation
1385 Ctyp : Conformance_Type) return Boolean;
1386 -- Verify that the signatures of the renamed entity and the new entity
1387 -- match. The first formal of the renamed entity is skipped because it
1388 -- is the target object in any subsequent call.
1392 Ctyp : Conformance_Type) return Boolean
1398 if Ekind (Subp) /= Ekind (New_S) then
1402 Old_F := Next_Formal (First_Formal (Subp));
1403 New_F := First_Formal (New_S);
1404 while Present (Old_F) and then Present (New_F) loop
1405 if not Conforming_Types (Etype (Old_F), Etype (New_F), Ctyp) then
1409 if Ctyp >= Mode_Conformant
1410 and then Ekind (Old_F) /= Ekind (New_F)
1415 Next_Formal (New_F);
1416 Next_Formal (Old_F);
1423 if not Is_Overloaded (Selector_Name (Name (N))) then
1424 Old_S := Entity (Selector_Name (Name (N)));
1426 if not Conforms (Old_S, Type_Conformant) then
1431 -- Find the operation that matches the given signature
1439 Get_First_Interp (Selector_Name (Name (N)), Ind, It);
1441 while Present (It.Nam) loop
1442 if Conforms (It.Nam, Type_Conformant) then
1446 Get_Next_Interp (Ind, It);
1451 if Old_S = Any_Id then
1452 Error_Msg_N (" no subprogram or entry matches specification", N);
1456 if not Conforms (Old_S, Subtype_Conformant) then
1457 Error_Msg_N ("subtype conformance error in renaming", N);
1460 Generate_Reference (New_S, Defining_Entity (N), 'b');
1461 Style.Check_Identifier (Defining_Entity (N), New_S);
1464 -- Only mode conformance required for a renaming_as_declaration
1466 if not Conforms (Old_S, Mode_Conformant) then
1467 Error_Msg_N ("mode conformance error in renaming", N);
1471 -- Inherit_Renamed_Profile (New_S, Old_S);
1473 -- The prefix can be an arbitrary expression that yields an
1474 -- object, so it must be resolved.
1476 Resolve (Prefix (Name (N)));
1478 end Analyze_Renamed_Primitive_Operation;
1480 ---------------------------------
1481 -- Analyze_Subprogram_Renaming --
1482 ---------------------------------
1484 procedure Analyze_Subprogram_Renaming (N : Node_Id) is
1485 Formal_Spec : constant Node_Id := Corresponding_Formal_Spec (N);
1486 Is_Actual : constant Boolean := Present (Formal_Spec);
1487 Inst_Node : Node_Id := Empty;
1488 Nam : constant Node_Id := Name (N);
1490 Old_S : Entity_Id := Empty;
1491 Rename_Spec : Entity_Id;
1492 Save_AV : constant Ada_Version_Type := Ada_Version;
1493 Save_AV_Exp : constant Ada_Version_Type := Ada_Version_Explicit;
1494 Spec : constant Node_Id := Specification (N);
1496 procedure Check_Null_Exclusion
1499 -- Ada 2005 (AI-423): Given renaming Ren of subprogram Sub, check the
1500 -- following AI rules:
1502 -- If Ren is a renaming of a formal subprogram and one of its
1503 -- parameters has a null exclusion, then the corresponding formal
1504 -- in Sub must also have one. Otherwise the subtype of the Sub's
1505 -- formal parameter must exclude null.
1507 -- If Ren is a renaming of a formal function and its return
1508 -- profile has a null exclusion, then Sub's return profile must
1509 -- have one. Otherwise the subtype of Sub's return profile must
1512 function Original_Subprogram (Subp : Entity_Id) return Entity_Id;
1513 -- Find renamed entity when the declaration is a renaming_as_body and
1514 -- the renamed entity may itself be a renaming_as_body. Used to enforce
1515 -- rule that a renaming_as_body is illegal if the declaration occurs
1516 -- before the subprogram it completes is frozen, and renaming indirectly
1517 -- renames the subprogram itself.(Defect Report 8652/0027).
1519 --------------------------
1520 -- Check_Null_Exclusion --
1521 --------------------------
1523 procedure Check_Null_Exclusion
1527 Ren_Formal : Entity_Id;
1528 Sub_Formal : Entity_Id;
1533 Ren_Formal := First_Formal (Ren);
1534 Sub_Formal := First_Formal (Sub);
1535 while Present (Ren_Formal)
1536 and then Present (Sub_Formal)
1538 if Has_Null_Exclusion (Parent (Ren_Formal))
1540 not (Has_Null_Exclusion (Parent (Sub_Formal))
1541 or else Can_Never_Be_Null (Etype (Sub_Formal)))
1544 ("`NOT NULL` required for parameter &",
1545 Parent (Sub_Formal), Sub_Formal);
1548 Next_Formal (Ren_Formal);
1549 Next_Formal (Sub_Formal);
1552 -- Return profile check
1554 if Nkind (Parent (Ren)) = N_Function_Specification
1555 and then Nkind (Parent (Sub)) = N_Function_Specification
1556 and then Has_Null_Exclusion (Parent (Ren))
1558 not (Has_Null_Exclusion (Parent (Sub))
1559 or else Can_Never_Be_Null (Etype (Sub)))
1562 ("return must specify `NOT NULL`",
1563 Result_Definition (Parent (Sub)));
1565 end Check_Null_Exclusion;
1567 -------------------------
1568 -- Original_Subprogram --
1569 -------------------------
1571 function Original_Subprogram (Subp : Entity_Id) return Entity_Id is
1572 Orig_Decl : Node_Id;
1573 Orig_Subp : Entity_Id;
1576 -- First case: renamed entity is itself a renaming
1578 if Present (Alias (Subp)) then
1579 return Alias (Subp);
1582 Nkind (Unit_Declaration_Node (Subp)) = N_Subprogram_Declaration
1584 (Corresponding_Body (Unit_Declaration_Node (Subp)))
1586 -- Check if renamed entity is a renaming_as_body
1589 Unit_Declaration_Node
1590 (Corresponding_Body (Unit_Declaration_Node (Subp)));
1592 if Nkind (Orig_Decl) = N_Subprogram_Renaming_Declaration then
1593 Orig_Subp := Entity (Name (Orig_Decl));
1595 if Orig_Subp = Rename_Spec then
1597 -- Circularity detected
1602 return (Original_Subprogram (Orig_Subp));
1610 end Original_Subprogram;
1612 -- Start of processing for Analyze_Subprogram_Renaming
1615 -- We must test for the attribute renaming case before the Analyze
1616 -- call because otherwise Sem_Attr will complain that the attribute
1617 -- is missing an argument when it is analyzed.
1619 if Nkind (Nam) = N_Attribute_Reference then
1621 -- In the case of an abstract formal subprogram association, rewrite
1622 -- an actual given by a stream attribute as the name of the
1623 -- corresponding stream primitive of the type.
1625 -- In a generic context the stream operations are not generated, and
1626 -- this must be treated as a normal attribute reference, to be
1627 -- expanded in subsequent instantiations.
1629 if Is_Actual and then Is_Abstract_Subprogram (Formal_Spec)
1630 and then Expander_Active
1633 Stream_Prim : Entity_Id;
1634 Prefix_Type : constant Entity_Id := Entity (Prefix (Nam));
1637 -- The class-wide forms of the stream attributes are not
1638 -- primitive dispatching operations (even though they
1639 -- internally dispatch to a stream attribute).
1641 if Is_Class_Wide_Type (Prefix_Type) then
1643 ("attribute must be a primitive dispatching operation",
1648 -- Retrieve the primitive subprogram associated with the
1649 -- attribute. This can only be a stream attribute, since those
1650 -- are the only ones that are dispatching (and the actual for
1651 -- an abstract formal subprogram must be dispatching
1655 case Attribute_Name (Nam) is
1658 Find_Prim_Op (Prefix_Type, TSS_Stream_Input);
1661 Find_Prim_Op (Prefix_Type, TSS_Stream_Output);
1664 Find_Prim_Op (Prefix_Type, TSS_Stream_Read);
1667 Find_Prim_Op (Prefix_Type, TSS_Stream_Write);
1670 ("attribute must be a primitive"
1671 & " dispatching operation", Nam);
1677 -- If no operation was found, and the type is limited,
1678 -- the user should have defined one.
1680 when Program_Error =>
1681 if Is_Limited_Type (Prefix_Type) then
1683 ("stream operation not defined for type&",
1687 -- Otherwise, compiler should have generated default
1694 -- Rewrite the attribute into the name of its corresponding
1695 -- primitive dispatching subprogram. We can then proceed with
1696 -- the usual processing for subprogram renamings.
1699 Prim_Name : constant Node_Id :=
1700 Make_Identifier (Sloc (Nam),
1701 Chars => Chars (Stream_Prim));
1703 Set_Entity (Prim_Name, Stream_Prim);
1704 Rewrite (Nam, Prim_Name);
1709 -- Normal processing for a renaming of an attribute
1712 Attribute_Renaming (N);
1717 -- Check whether this declaration corresponds to the instantiation
1718 -- of a formal subprogram.
1720 -- If this is an instantiation, the corresponding actual is frozen and
1721 -- error messages can be made more precise. If this is a default
1722 -- subprogram, the entity is already established in the generic, and is
1723 -- not retrieved by visibility. If it is a default with a box, the
1724 -- candidate interpretations, if any, have been collected when building
1725 -- the renaming declaration. If overloaded, the proper interpretation is
1726 -- determined in Find_Renamed_Entity. If the entity is an operator,
1727 -- Find_Renamed_Entity applies additional visibility checks.
1730 Inst_Node := Unit_Declaration_Node (Formal_Spec);
1732 if Is_Entity_Name (Nam)
1733 and then Present (Entity (Nam))
1734 and then not Comes_From_Source (Nam)
1735 and then not Is_Overloaded (Nam)
1737 Old_S := Entity (Nam);
1738 New_S := Analyze_Subprogram_Specification (Spec);
1742 if Ekind (Entity (Nam)) = E_Operator then
1746 if Box_Present (Inst_Node) then
1747 Old_S := Find_Renamed_Entity (N, Name (N), New_S, Is_Actual);
1749 -- If there is an immediately visible homonym of the operator
1750 -- and the declaration has a default, this is worth a warning
1751 -- because the user probably did not intend to get the pre-
1752 -- defined operator, visible in the generic declaration. To
1753 -- find if there is an intended candidate, analyze the renaming
1754 -- again in the current context.
1756 elsif Scope (Old_S) = Standard_Standard
1757 and then Present (Default_Name (Inst_Node))
1760 Decl : constant Node_Id := New_Copy_Tree (N);
1764 Set_Entity (Name (Decl), Empty);
1765 Analyze (Name (Decl));
1767 Find_Renamed_Entity (Decl, Name (Decl), New_S, True);
1770 and then In_Open_Scopes (Scope (Hidden))
1771 and then Is_Immediately_Visible (Hidden)
1772 and then Comes_From_Source (Hidden)
1773 and then Hidden /= Old_S
1775 Error_Msg_Sloc := Sloc (Hidden);
1776 Error_Msg_N ("?default subprogram is resolved " &
1777 "in the generic declaration " &
1778 "(RM 12.6(17))", N);
1779 Error_Msg_NE ("\?and will not use & #", N, Hidden);
1787 New_S := Analyze_Subprogram_Specification (Spec);
1791 -- Renamed entity must be analyzed first, to avoid being hidden by
1792 -- new name (which might be the same in a generic instance).
1796 -- The renaming defines a new overloaded entity, which is analyzed
1797 -- like a subprogram declaration.
1799 New_S := Analyze_Subprogram_Specification (Spec);
1802 if Current_Scope /= Standard_Standard then
1803 Set_Is_Pure (New_S, Is_Pure (Current_Scope));
1806 Rename_Spec := Find_Corresponding_Spec (N);
1808 -- Case of Renaming_As_Body
1810 if Present (Rename_Spec) then
1812 -- Renaming declaration is the completion of the declaration of
1813 -- Rename_Spec. We build an actual body for it at the freezing point.
1815 Set_Corresponding_Spec (N, Rename_Spec);
1817 -- Deal with special case of stream functions of abstract types
1820 if Nkind (Unit_Declaration_Node (Rename_Spec)) =
1821 N_Abstract_Subprogram_Declaration
1823 -- Input stream functions are abstract if the object type is
1824 -- abstract. Similarly, all default stream functions for an
1825 -- interface type are abstract. However, these subprograms may
1826 -- receive explicit declarations in representation clauses, making
1827 -- the attribute subprograms usable as defaults in subsequent
1829 -- In this case we rewrite the declaration to make the subprogram
1830 -- non-abstract. We remove the previous declaration, and insert
1831 -- the new one at the point of the renaming, to prevent premature
1832 -- access to unfrozen types. The new declaration reuses the
1833 -- specification of the previous one, and must not be analyzed.
1836 (Is_Primitive (Entity (Nam))
1838 Is_Abstract_Type (Find_Dispatching_Type (Entity (Nam))));
1840 Old_Decl : constant Node_Id :=
1841 Unit_Declaration_Node (Rename_Spec);
1842 New_Decl : constant Node_Id :=
1843 Make_Subprogram_Declaration (Sloc (N),
1845 Relocate_Node (Specification (Old_Decl)));
1848 Insert_After (N, New_Decl);
1849 Set_Is_Abstract_Subprogram (Rename_Spec, False);
1850 Set_Analyzed (New_Decl);
1854 Set_Corresponding_Body (Unit_Declaration_Node (Rename_Spec), New_S);
1856 if Ada_Version = Ada_83 and then Comes_From_Source (N) then
1857 Error_Msg_N ("(Ada 83) renaming cannot serve as a body", N);
1860 Set_Convention (New_S, Convention (Rename_Spec));
1861 Check_Fully_Conformant (New_S, Rename_Spec);
1862 Set_Public_Status (New_S);
1864 -- The specification does not introduce new formals, but only
1865 -- repeats the formals of the original subprogram declaration.
1866 -- For cross-reference purposes, and for refactoring tools, we
1867 -- treat the formals of the renaming declaration as body formals.
1869 Reference_Body_Formals (Rename_Spec, New_S);
1871 -- Indicate that the entity in the declaration functions like the
1872 -- corresponding body, and is not a new entity. The body will be
1873 -- constructed later at the freeze point, so indicate that the
1874 -- completion has not been seen yet.
1876 Set_Ekind (New_S, E_Subprogram_Body);
1877 New_S := Rename_Spec;
1878 Set_Has_Completion (Rename_Spec, False);
1880 -- Ada 2005: check overriding indicator
1882 if Is_Overriding_Operation (Rename_Spec) then
1883 if Must_Not_Override (Specification (N)) then
1885 ("subprogram& overrides inherited operation",
1888 Style_Check and then not Must_Override (Specification (N))
1890 Style.Missing_Overriding (N, Rename_Spec);
1893 elsif Must_Override (Specification (N)) then
1894 Error_Msg_NE ("subprogram& is not overriding", N, Rename_Spec);
1897 -- Normal subprogram renaming (not renaming as body)
1900 Generate_Definition (New_S);
1901 New_Overloaded_Entity (New_S);
1903 if Is_Entity_Name (Nam)
1904 and then Is_Intrinsic_Subprogram (Entity (Nam))
1908 Check_Delayed_Subprogram (New_S);
1912 -- There is no need for elaboration checks on the new entity, which may
1913 -- be called before the next freezing point where the body will appear.
1914 -- Elaboration checks refer to the real entity, not the one created by
1915 -- the renaming declaration.
1917 Set_Kill_Elaboration_Checks (New_S, True);
1919 if Etype (Nam) = Any_Type then
1920 Set_Has_Completion (New_S);
1923 elsif Nkind (Nam) = N_Selected_Component then
1925 -- A prefix of the form A.B can designate an entry of task A, a
1926 -- protected operation of protected object A, or finally a primitive
1927 -- operation of object A. In the later case, A is an object of some
1928 -- tagged type, or an access type that denotes one such. To further
1929 -- distinguish these cases, note that the scope of a task entry or
1930 -- protected operation is type of the prefix.
1932 -- The prefix could be an overloaded function call that returns both
1933 -- kinds of operations. This overloading pathology is left to the
1934 -- dedicated reader ???
1937 T : constant Entity_Id := Etype (Prefix (Nam));
1946 Is_Tagged_Type (Designated_Type (T))))
1947 and then Scope (Entity (Selector_Name (Nam))) /= T
1949 Analyze_Renamed_Primitive_Operation
1950 (N, New_S, Present (Rename_Spec));
1954 -- Renamed entity is an entry or protected operation. For those
1955 -- cases an explicit body is built (at the point of freezing of
1956 -- this entity) that contains a call to the renamed entity.
1958 -- This is not allowed for renaming as body if the renamed
1959 -- spec is already frozen (see RM 8.5.4(5) for details).
1961 if Present (Rename_Spec)
1962 and then Is_Frozen (Rename_Spec)
1965 ("renaming-as-body cannot rename entry as subprogram", N);
1967 ("\since & is already frozen (RM 8.5.4(5))",
1970 Analyze_Renamed_Entry (N, New_S, Present (Rename_Spec));
1977 elsif Nkind (Nam) = N_Explicit_Dereference then
1979 -- Renamed entity is designated by access_to_subprogram expression.
1980 -- Must build body to encapsulate call, as in the entry case.
1982 Analyze_Renamed_Dereference (N, New_S, Present (Rename_Spec));
1985 elsif Nkind (Nam) = N_Indexed_Component then
1986 Analyze_Renamed_Family_Member (N, New_S, Present (Rename_Spec));
1989 elsif Nkind (Nam) = N_Character_Literal then
1990 Analyze_Renamed_Character (N, New_S, Present (Rename_Spec));
1993 elsif (not Is_Entity_Name (Nam)
1994 and then Nkind (Nam) /= N_Operator_Symbol)
1995 or else not Is_Overloadable (Entity (Nam))
1997 Error_Msg_N ("expect valid subprogram name in renaming", N);
2001 -- Find the renamed entity that matches the given specification. Disable
2002 -- Ada_83 because there is no requirement of full conformance between
2003 -- renamed entity and new entity, even though the same circuit is used.
2005 -- This is a bit of a kludge, which introduces a really irregular use of
2006 -- Ada_Version[_Explicit]. Would be nice to find cleaner way to do this
2009 Ada_Version := Ada_Version_Type'Max (Ada_Version, Ada_95);
2010 Ada_Version_Explicit := Ada_Version;
2013 Old_S := Find_Renamed_Entity (N, Name (N), New_S, Is_Actual);
2015 -- When the renamed subprogram is overloaded and used as an actual
2016 -- of a generic, its entity is set to the first available homonym.
2017 -- We must first disambiguate the name, then set the proper entity.
2020 and then Is_Overloaded (Nam)
2022 Set_Entity (Nam, Old_S);
2026 -- Most common case: subprogram renames subprogram. No body is generated
2027 -- in this case, so we must indicate the declaration is complete as is.
2028 -- and inherit various attributes of the renamed subprogram.
2030 if No (Rename_Spec) then
2031 Set_Has_Completion (New_S);
2032 Set_Is_Imported (New_S, Is_Imported (Entity (Nam)));
2033 Set_Is_Pure (New_S, Is_Pure (Entity (Nam)));
2034 Set_Is_Preelaborated (New_S, Is_Preelaborated (Entity (Nam)));
2036 -- Ada 2005 (AI-423): Check the consistency of null exclusions
2037 -- between a subprogram and its correct renaming.
2039 -- Note: the Any_Id check is a guard that prevents compiler crashes
2040 -- when performing a null exclusion check between a renaming and a
2041 -- renamed subprogram that has been found to be illegal.
2043 if Ada_Version >= Ada_05
2044 and then Entity (Nam) /= Any_Id
2046 Check_Null_Exclusion
2048 Sub => Entity (Nam));
2051 -- Enforce the Ada 2005 rule that the renamed entity cannot require
2052 -- overriding. The flag Requires_Overriding is set very selectively
2053 -- and misses some other illegal cases. The additional conditions
2054 -- checked below are sufficient but not necessary ???
2056 -- The rule does not apply to the renaming generated for an actual
2057 -- subprogram in an instance.
2062 -- Guard against previous errors, and omit renamings of predefined
2065 elsif Ekind (Old_S) /= E_Function
2066 and then Ekind (Old_S) /= E_Procedure
2070 elsif Requires_Overriding (Old_S)
2072 (Is_Abstract_Subprogram (Old_S)
2073 and then Present (Find_Dispatching_Type (Old_S))
2075 not Is_Abstract_Type (Find_Dispatching_Type (Old_S)))
2078 ("renamed entity cannot be "
2079 & "subprogram that requires overriding (RM 8.5.4 (5.1))", N);
2083 if Old_S /= Any_Id then
2085 and then From_Default (N)
2087 -- This is an implicit reference to the default actual
2089 Generate_Reference (Old_S, Nam, Typ => 'i', Force => True);
2091 Generate_Reference (Old_S, Nam);
2094 -- For a renaming-as-body, require subtype conformance, but if the
2095 -- declaration being completed has not been frozen, then inherit the
2096 -- convention of the renamed subprogram prior to checking conformance
2097 -- (unless the renaming has an explicit convention established; the
2098 -- rule stated in the RM doesn't seem to address this ???).
2100 if Present (Rename_Spec) then
2101 Generate_Reference (Rename_Spec, Defining_Entity (Spec), 'b');
2102 Style.Check_Identifier (Defining_Entity (Spec), Rename_Spec);
2104 if not Is_Frozen (Rename_Spec) then
2105 if not Has_Convention_Pragma (Rename_Spec) then
2106 Set_Convention (New_S, Convention (Old_S));
2109 if Ekind (Old_S) /= E_Operator then
2110 Check_Mode_Conformant (New_S, Old_S, Spec);
2113 if Original_Subprogram (Old_S) = Rename_Spec then
2114 Error_Msg_N ("unfrozen subprogram cannot rename itself ", N);
2117 Check_Subtype_Conformant (New_S, Old_S, Spec);
2120 Check_Frozen_Renaming (N, Rename_Spec);
2122 -- Check explicitly that renamed entity is not intrinsic, because
2123 -- in a generic the renamed body is not built. In this case,
2124 -- the renaming_as_body is a completion.
2126 if Inside_A_Generic then
2127 if Is_Frozen (Rename_Spec)
2128 and then Is_Intrinsic_Subprogram (Old_S)
2131 ("subprogram in renaming_as_body cannot be intrinsic",
2135 Set_Has_Completion (Rename_Spec);
2138 elsif Ekind (Old_S) /= E_Operator then
2139 Check_Mode_Conformant (New_S, Old_S);
2142 and then Error_Posted (New_S)
2144 Error_Msg_NE ("invalid actual subprogram: & #!", N, Old_S);
2148 if No (Rename_Spec) then
2150 -- The parameter profile of the new entity is that of the renamed
2151 -- entity: the subtypes given in the specification are irrelevant.
2153 Inherit_Renamed_Profile (New_S, Old_S);
2155 -- A call to the subprogram is transformed into a call to the
2156 -- renamed entity. This is transitive if the renamed entity is
2157 -- itself a renaming.
2159 if Present (Alias (Old_S)) then
2160 Set_Alias (New_S, Alias (Old_S));
2162 Set_Alias (New_S, Old_S);
2165 -- Note that we do not set Is_Intrinsic_Subprogram if we have a
2166 -- renaming as body, since the entity in this case is not an
2167 -- intrinsic (it calls an intrinsic, but we have a real body for
2168 -- this call, and it is in this body that the required intrinsic
2169 -- processing will take place).
2171 -- Also, if this is a renaming of inequality, the renamed operator
2172 -- is intrinsic, but what matters is the corresponding equality
2173 -- operator, which may be user-defined.
2175 Set_Is_Intrinsic_Subprogram
2177 Is_Intrinsic_Subprogram (Old_S)
2179 (Chars (Old_S) /= Name_Op_Ne
2180 or else Ekind (Old_S) = E_Operator
2182 Is_Intrinsic_Subprogram
2183 (Corresponding_Equality (Old_S))));
2185 if Ekind (Alias (New_S)) = E_Operator then
2186 Set_Has_Delayed_Freeze (New_S, False);
2189 -- If the renaming corresponds to an association for an abstract
2190 -- formal subprogram, then various attributes must be set to
2191 -- indicate that the renaming is an abstract dispatching operation
2192 -- with a controlling type.
2194 if Is_Actual and then Is_Abstract_Subprogram (Formal_Spec) then
2196 -- Mark the renaming as abstract here, so Find_Dispatching_Type
2197 -- see it as corresponding to a generic association for a
2198 -- formal abstract subprogram
2200 Set_Is_Abstract_Subprogram (New_S);
2203 New_S_Ctrl_Type : constant Entity_Id :=
2204 Find_Dispatching_Type (New_S);
2205 Old_S_Ctrl_Type : constant Entity_Id :=
2206 Find_Dispatching_Type (Old_S);
2209 if Old_S_Ctrl_Type /= New_S_Ctrl_Type then
2211 ("actual must be dispatching subprogram for type&",
2212 Nam, New_S_Ctrl_Type);
2215 Set_Is_Dispatching_Operation (New_S);
2216 Check_Controlling_Formals (New_S_Ctrl_Type, New_S);
2218 -- If the actual in the formal subprogram is itself a
2219 -- formal abstract subprogram association, there's no
2220 -- dispatch table component or position to inherit.
2222 if Present (DTC_Entity (Old_S)) then
2223 Set_DTC_Entity (New_S, DTC_Entity (Old_S));
2224 Set_DT_Position (New_S, DT_Position (Old_S));
2232 and then (Old_S = New_S
2233 or else (Nkind (Nam) /= N_Expanded_Name
2234 and then Chars (Old_S) = Chars (New_S)))
2236 Error_Msg_N ("subprogram cannot rename itself", N);
2239 Set_Convention (New_S, Convention (Old_S));
2241 if Is_Abstract_Subprogram (Old_S) then
2242 if Present (Rename_Spec) then
2244 ("a renaming-as-body cannot rename an abstract subprogram",
2246 Set_Has_Completion (Rename_Spec);
2248 Set_Is_Abstract_Subprogram (New_S);
2252 Check_Library_Unit_Renaming (N, Old_S);
2254 -- Pathological case: procedure renames entry in the scope of its
2255 -- task. Entry is given by simple name, but body must be built for
2256 -- procedure. Of course if called it will deadlock.
2258 if Ekind (Old_S) = E_Entry then
2259 Set_Has_Completion (New_S, False);
2260 Set_Alias (New_S, Empty);
2264 Freeze_Before (N, Old_S);
2265 Set_Has_Delayed_Freeze (New_S, False);
2266 Freeze_Before (N, New_S);
2268 -- An abstract subprogram is only allowed as an actual in the case
2269 -- where the formal subprogram is also abstract.
2271 if (Ekind (Old_S) = E_Procedure or else Ekind (Old_S) = E_Function)
2272 and then Is_Abstract_Subprogram (Old_S)
2273 and then not Is_Abstract_Subprogram (Formal_Spec)
2276 ("abstract subprogram not allowed as generic actual", Nam);
2281 -- A common error is to assume that implicit operators for types are
2282 -- defined in Standard, or in the scope of a subtype. In those cases
2283 -- where the renamed entity is given with an expanded name, it is
2284 -- worth mentioning that operators for the type are not declared in
2285 -- the scope given by the prefix.
2287 if Nkind (Nam) = N_Expanded_Name
2288 and then Nkind (Selector_Name (Nam)) = N_Operator_Symbol
2289 and then Scope (Entity (Nam)) = Standard_Standard
2292 T : constant Entity_Id :=
2293 Base_Type (Etype (First_Formal (New_S)));
2295 Error_Msg_Node_2 := Prefix (Nam);
2297 ("operator for type& is not declared in&", Prefix (Nam), T);
2302 ("no visible subprogram matches the specification for&",
2306 if Present (Candidate_Renaming) then
2312 F1 := First_Formal (Candidate_Renaming);
2313 F2 := First_Formal (New_S);
2315 while Present (F1) and then Present (F2) loop
2320 if Present (F1) and then Present (Default_Value (F1)) then
2321 if Present (Next_Formal (F1)) then
2323 ("\missing specification for &" &
2324 " and other formals with defaults", Spec, F1);
2327 ("\missing specification for &", Spec, F1);
2334 -- Ada 2005 AI 404: if the new subprogram is dispatching, verify that
2335 -- controlling access parameters are known non-null for the renamed
2336 -- subprogram. Test also applies to a subprogram instantiation that
2337 -- is dispatching. Test is skipped if some previous error was detected
2338 -- that set Old_S to Any_Id.
2340 if Ada_Version >= Ada_05
2341 and then Old_S /= Any_Id
2342 and then not Is_Dispatching_Operation (Old_S)
2343 and then Is_Dispatching_Operation (New_S)
2350 Old_F := First_Formal (Old_S);
2351 New_F := First_Formal (New_S);
2352 while Present (Old_F) loop
2353 if Ekind (Etype (Old_F)) = E_Anonymous_Access_Type
2354 and then Is_Controlling_Formal (New_F)
2355 and then not Can_Never_Be_Null (Old_F)
2357 Error_Msg_N ("access parameter is controlling,", New_F);
2359 ("\corresponding parameter of& "
2360 & "must be explicitly null excluding", New_F, Old_S);
2363 Next_Formal (Old_F);
2364 Next_Formal (New_F);
2369 -- A useful warning, suggested by Ada Bug Finder (Ada-Europe 2005)
2371 if Comes_From_Source (N)
2372 and then Present (Old_S)
2373 and then Nkind (Old_S) = N_Defining_Operator_Symbol
2374 and then Nkind (New_S) = N_Defining_Operator_Symbol
2375 and then Chars (Old_S) /= Chars (New_S)
2378 ("?& is being renamed as a different operator",
2382 -- Another warning or some utility: if the new subprogram as the same
2383 -- name as the old one, the old one is not hidden by an outer homograph,
2384 -- the new one is not a public symbol, and the old one is otherwise
2385 -- directly visible, the renaming is superfluous.
2387 if Chars (Old_S) = Chars (New_S)
2388 and then Comes_From_Source (N)
2389 and then Scope (Old_S) /= Standard_Standard
2390 and then Warn_On_Redundant_Constructs
2392 (Is_Immediately_Visible (Old_S)
2393 or else Is_Potentially_Use_Visible (Old_S))
2394 and then Is_Overloadable (Current_Scope)
2395 and then Chars (Current_Scope) /= Chars (Old_S)
2398 ("?redundant renaming, entity is directly visible", Name (N));
2401 Ada_Version := Save_AV;
2402 Ada_Version_Explicit := Save_AV_Exp;
2403 end Analyze_Subprogram_Renaming;
2405 -------------------------
2406 -- Analyze_Use_Package --
2407 -------------------------
2409 -- Resolve the package names in the use clause, and make all the visible
2410 -- entities defined in the package potentially use-visible. If the package
2411 -- is already in use from a previous use clause, its visible entities are
2412 -- already use-visible. In that case, mark the occurrence as a redundant
2413 -- use. If the package is an open scope, i.e. if the use clause occurs
2414 -- within the package itself, ignore it.
2416 procedure Analyze_Use_Package (N : Node_Id) is
2417 Pack_Name : Node_Id;
2420 -- Start of processing for Analyze_Use_Package
2423 Set_Hidden_By_Use_Clause (N, No_Elist);
2425 -- Use clause is not allowed in a spec of a predefined package
2426 -- declaration except that packages whose file name starts a-n are OK
2427 -- (these are children of Ada.Numerics, and such packages are never
2428 -- loaded by Rtsfind).
2430 if Is_Predefined_File_Name (Unit_File_Name (Current_Sem_Unit))
2431 and then Name_Buffer (1 .. 3) /= "a-n"
2433 Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Declaration
2435 Error_Msg_N ("use clause not allowed in predefined spec", N);
2438 -- Chain clause to list of use clauses in current scope
2440 if Nkind (Parent (N)) /= N_Compilation_Unit then
2441 Chain_Use_Clause (N);
2444 -- Loop through package names to identify referenced packages
2446 Pack_Name := First (Names (N));
2447 while Present (Pack_Name) loop
2448 Analyze (Pack_Name);
2450 if Nkind (Parent (N)) = N_Compilation_Unit
2451 and then Nkind (Pack_Name) = N_Expanded_Name
2457 Pref := Prefix (Pack_Name);
2458 while Nkind (Pref) = N_Expanded_Name loop
2459 Pref := Prefix (Pref);
2462 if Entity (Pref) = Standard_Standard then
2464 ("predefined package Standard cannot appear"
2465 & " in a context clause", Pref);
2473 -- Loop through package names to mark all entities as potentially
2476 Pack_Name := First (Names (N));
2477 while Present (Pack_Name) loop
2478 if Is_Entity_Name (Pack_Name) then
2479 Pack := Entity (Pack_Name);
2481 if Ekind (Pack) /= E_Package
2482 and then Etype (Pack) /= Any_Type
2484 if Ekind (Pack) = E_Generic_Package then
2486 ("a generic package is not allowed in a use clause",
2489 Error_Msg_N ("& is not a usable package", Pack_Name);
2493 if Nkind (Parent (N)) = N_Compilation_Unit then
2494 Check_In_Previous_With_Clause (N, Pack_Name);
2497 if Applicable_Use (Pack_Name) then
2498 Use_One_Package (Pack, N);
2502 -- Report error because name denotes something other than a package
2505 Error_Msg_N ("& is not a package", Pack_Name);
2510 end Analyze_Use_Package;
2512 ----------------------
2513 -- Analyze_Use_Type --
2514 ----------------------
2516 procedure Analyze_Use_Type (N : Node_Id) is
2521 Set_Hidden_By_Use_Clause (N, No_Elist);
2523 -- Chain clause to list of use clauses in current scope
2525 if Nkind (Parent (N)) /= N_Compilation_Unit then
2526 Chain_Use_Clause (N);
2529 Id := First (Subtype_Marks (N));
2530 while Present (Id) loop
2534 if E /= Any_Type then
2537 if Nkind (Parent (N)) = N_Compilation_Unit then
2538 if Nkind (Id) = N_Identifier then
2539 Error_Msg_N ("type is not directly visible", Id);
2541 elsif Is_Child_Unit (Scope (E))
2542 and then Scope (E) /= System_Aux_Id
2544 Check_In_Previous_With_Clause (N, Prefix (Id));
2551 end Analyze_Use_Type;
2553 --------------------
2554 -- Applicable_Use --
2555 --------------------
2557 function Applicable_Use (Pack_Name : Node_Id) return Boolean is
2558 Pack : constant Entity_Id := Entity (Pack_Name);
2561 if In_Open_Scopes (Pack) then
2562 if Warn_On_Redundant_Constructs
2563 and then Pack = Current_Scope
2566 ("& is already use-visible within itself?", Pack_Name, Pack);
2571 elsif In_Use (Pack) then
2572 Note_Redundant_Use (Pack_Name);
2575 elsif Present (Renamed_Object (Pack))
2576 and then In_Use (Renamed_Object (Pack))
2578 Note_Redundant_Use (Pack_Name);
2586 ------------------------
2587 -- Attribute_Renaming --
2588 ------------------------
2590 procedure Attribute_Renaming (N : Node_Id) is
2591 Loc : constant Source_Ptr := Sloc (N);
2592 Nam : constant Node_Id := Name (N);
2593 Spec : constant Node_Id := Specification (N);
2594 New_S : constant Entity_Id := Defining_Unit_Name (Spec);
2595 Aname : constant Name_Id := Attribute_Name (Nam);
2597 Form_Num : Nat := 0;
2598 Expr_List : List_Id := No_List;
2600 Attr_Node : Node_Id;
2601 Body_Node : Node_Id;
2602 Param_Spec : Node_Id;
2605 Generate_Definition (New_S);
2607 -- This procedure is called in the context of subprogram renaming,
2608 -- and thus the attribute must be one that is a subprogram. All of
2609 -- those have at least one formal parameter, with the singular
2610 -- exception of AST_Entry (which is a real oddity, it is odd that
2611 -- this can be renamed at all!)
2613 if not Is_Non_Empty_List (Parameter_Specifications (Spec)) then
2614 if Aname /= Name_AST_Entry then
2616 ("subprogram renaming an attribute must have formals", N);
2621 Param_Spec := First (Parameter_Specifications (Spec));
2622 while Present (Param_Spec) loop
2623 Form_Num := Form_Num + 1;
2625 if Nkind (Parameter_Type (Param_Spec)) /= N_Access_Definition then
2626 Find_Type (Parameter_Type (Param_Spec));
2628 -- The profile of the new entity denotes the base type (s) of
2629 -- the types given in the specification. For access parameters
2630 -- there are no subtypes involved.
2632 Rewrite (Parameter_Type (Param_Spec),
2634 (Base_Type (Entity (Parameter_Type (Param_Spec))), Loc));
2637 if No (Expr_List) then
2638 Expr_List := New_List;
2641 Append_To (Expr_List,
2642 Make_Identifier (Loc,
2643 Chars => Chars (Defining_Identifier (Param_Spec))));
2645 -- The expressions in the attribute reference are not freeze
2646 -- points. Neither is the attribute as a whole, see below.
2648 Set_Must_Not_Freeze (Last (Expr_List));
2653 -- Immediate error if too many formals. Other mismatches in numbers
2654 -- of number of types of parameters are detected when we analyze the
2655 -- body of the subprogram that we construct.
2657 if Form_Num > 2 then
2658 Error_Msg_N ("too many formals for attribute", N);
2660 -- Error if the attribute reference has expressions that look
2661 -- like formal parameters.
2663 elsif Present (Expressions (Nam)) then
2664 Error_Msg_N ("illegal expressions in attribute reference", Nam);
2667 Aname = Name_Compose or else
2668 Aname = Name_Exponent or else
2669 Aname = Name_Leading_Part or else
2670 Aname = Name_Pos or else
2671 Aname = Name_Round or else
2672 Aname = Name_Scaling or else
2675 if Nkind (N) = N_Subprogram_Renaming_Declaration
2676 and then Present (Corresponding_Formal_Spec (N))
2679 ("generic actual cannot be attribute involving universal type",
2683 ("attribute involving a universal type cannot be renamed",
2688 -- AST_Entry is an odd case. It doesn't really make much sense to
2689 -- allow it to be renamed, but that's the DEC rule, so we have to
2690 -- do it right. The point is that the AST_Entry call should be made
2691 -- now, and what the function will return is the returned value.
2693 -- Note that there is no Expr_List in this case anyway
2695 if Aname = Name_AST_Entry then
2701 Ent := Make_Defining_Identifier (Loc, New_Internal_Name ('R'));
2704 Make_Object_Declaration (Loc,
2705 Defining_Identifier => Ent,
2706 Object_Definition =>
2707 New_Occurrence_Of (RTE (RE_AST_Handler), Loc),
2709 Constant_Present => True);
2711 Set_Assignment_OK (Decl, True);
2712 Insert_Action (N, Decl);
2713 Attr_Node := Make_Identifier (Loc, Chars (Ent));
2716 -- For all other attributes, we rewrite the attribute node to have
2717 -- a list of expressions corresponding to the subprogram formals.
2718 -- A renaming declaration is not a freeze point, and the analysis of
2719 -- the attribute reference should not freeze the type of the prefix.
2723 Make_Attribute_Reference (Loc,
2724 Prefix => Prefix (Nam),
2725 Attribute_Name => Aname,
2726 Expressions => Expr_List);
2728 Set_Must_Not_Freeze (Attr_Node);
2729 Set_Must_Not_Freeze (Prefix (Nam));
2732 -- Case of renaming a function
2734 if Nkind (Spec) = N_Function_Specification then
2735 if Is_Procedure_Attribute_Name (Aname) then
2736 Error_Msg_N ("attribute can only be renamed as procedure", Nam);
2740 Find_Type (Result_Definition (Spec));
2741 Rewrite (Result_Definition (Spec),
2743 Base_Type (Entity (Result_Definition (Spec))), Loc));
2746 Make_Subprogram_Body (Loc,
2747 Specification => Spec,
2748 Declarations => New_List,
2749 Handled_Statement_Sequence =>
2750 Make_Handled_Sequence_Of_Statements (Loc,
2751 Statements => New_List (
2752 Make_Simple_Return_Statement (Loc,
2753 Expression => Attr_Node))));
2755 -- Case of renaming a procedure
2758 if not Is_Procedure_Attribute_Name (Aname) then
2759 Error_Msg_N ("attribute can only be renamed as function", Nam);
2764 Make_Subprogram_Body (Loc,
2765 Specification => Spec,
2766 Declarations => New_List,
2767 Handled_Statement_Sequence =>
2768 Make_Handled_Sequence_Of_Statements (Loc,
2769 Statements => New_List (Attr_Node)));
2772 -- In case of tagged types we add the body of the generated function to
2773 -- the freezing actions of the type (because in the general case such
2774 -- type is still not frozen). We exclude from this processing generic
2775 -- formal subprograms found in instantiations and AST_Entry renamings.
2777 if not Present (Corresponding_Formal_Spec (N))
2778 and then Etype (Nam) /= RTE (RE_AST_Handler)
2781 P : constant Entity_Id := Prefix (Nam);
2786 if Is_Tagged_Type (Etype (P)) then
2787 Ensure_Freeze_Node (Etype (P));
2788 Append_Freeze_Action (Etype (P), Body_Node);
2790 Rewrite (N, Body_Node);
2792 Set_Etype (New_S, Base_Type (Etype (New_S)));
2796 -- Generic formal subprograms or AST_Handler renaming
2799 Rewrite (N, Body_Node);
2801 Set_Etype (New_S, Base_Type (Etype (New_S)));
2804 if Is_Compilation_Unit (New_S) then
2806 ("a library unit can only rename another library unit", N);
2809 -- We suppress elaboration warnings for the resulting entity, since
2810 -- clearly they are not needed, and more particularly, in the case
2811 -- of a generic formal subprogram, the resulting entity can appear
2812 -- after the instantiation itself, and thus look like a bogus case
2813 -- of access before elaboration.
2815 Set_Suppress_Elaboration_Warnings (New_S);
2817 end Attribute_Renaming;
2819 ----------------------
2820 -- Chain_Use_Clause --
2821 ----------------------
2823 procedure Chain_Use_Clause (N : Node_Id) is
2825 Level : Int := Scope_Stack.Last;
2828 if not Is_Compilation_Unit (Current_Scope)
2829 or else not Is_Child_Unit (Current_Scope)
2831 null; -- Common case
2833 elsif Defining_Entity (Parent (N)) = Current_Scope then
2834 null; -- Common case for compilation unit
2837 -- If declaration appears in some other scope, it must be in some
2838 -- parent unit when compiling a child.
2840 Pack := Defining_Entity (Parent (N));
2841 if not In_Open_Scopes (Pack) then
2842 null; -- default as well
2845 -- Find entry for parent unit in scope stack
2847 while Scope_Stack.Table (Level).Entity /= Pack loop
2853 Set_Next_Use_Clause (N,
2854 Scope_Stack.Table (Level).First_Use_Clause);
2855 Scope_Stack.Table (Level).First_Use_Clause := N;
2856 end Chain_Use_Clause;
2858 ---------------------------
2859 -- Check_Frozen_Renaming --
2860 ---------------------------
2862 procedure Check_Frozen_Renaming (N : Node_Id; Subp : Entity_Id) is
2868 and then not Has_Completion (Subp)
2872 (Parent (Declaration_Node (Subp)), Defining_Entity (N));
2874 if Is_Entity_Name (Name (N)) then
2875 Old_S := Entity (Name (N));
2877 if not Is_Frozen (Old_S)
2878 and then Operating_Mode /= Check_Semantics
2880 Append_Freeze_Action (Old_S, B_Node);
2882 Insert_After (N, B_Node);
2886 if Is_Intrinsic_Subprogram (Old_S)
2887 and then not In_Instance
2890 ("subprogram used in renaming_as_body cannot be intrinsic",
2895 Insert_After (N, B_Node);
2899 end Check_Frozen_Renaming;
2901 -----------------------------------
2902 -- Check_In_Previous_With_Clause --
2903 -----------------------------------
2905 procedure Check_In_Previous_With_Clause
2909 Pack : constant Entity_Id := Entity (Original_Node (Nam));
2914 Item := First (Context_Items (Parent (N)));
2916 while Present (Item)
2919 if Nkind (Item) = N_With_Clause
2921 -- Protect the frontend against previous critical errors
2923 and then Nkind (Name (Item)) /= N_Selected_Component
2924 and then Entity (Name (Item)) = Pack
2928 -- Find root library unit in with_clause
2930 while Nkind (Par) = N_Expanded_Name loop
2931 Par := Prefix (Par);
2934 if Is_Child_Unit (Entity (Original_Node (Par))) then
2936 ("& is not directly visible", Par, Entity (Par));
2945 -- On exit, package is not mentioned in a previous with_clause.
2946 -- Check if its prefix is.
2948 if Nkind (Nam) = N_Expanded_Name then
2949 Check_In_Previous_With_Clause (N, Prefix (Nam));
2951 elsif Pack /= Any_Id then
2952 Error_Msg_NE ("& is not visible", Nam, Pack);
2954 end Check_In_Previous_With_Clause;
2956 ---------------------------------
2957 -- Check_Library_Unit_Renaming --
2958 ---------------------------------
2960 procedure Check_Library_Unit_Renaming (N : Node_Id; Old_E : Entity_Id) is
2964 if Nkind (Parent (N)) /= N_Compilation_Unit then
2967 -- Check for library unit. Note that we used to check for the scope
2968 -- being Standard here, but that was wrong for Standard itself.
2970 elsif not Is_Compilation_Unit (Old_E)
2971 and then not Is_Child_Unit (Old_E)
2973 Error_Msg_N ("renamed unit must be a library unit", Name (N));
2975 -- Entities defined in Standard (operators and boolean literals) cannot
2976 -- be renamed as library units.
2978 elsif Scope (Old_E) = Standard_Standard
2979 and then Sloc (Old_E) = Standard_Location
2981 Error_Msg_N ("renamed unit must be a library unit", Name (N));
2983 elsif Present (Parent_Spec (N))
2984 and then Nkind (Unit (Parent_Spec (N))) = N_Generic_Package_Declaration
2985 and then not Is_Child_Unit (Old_E)
2988 ("renamed unit must be a child unit of generic parent", Name (N));
2990 elsif Nkind (N) in N_Generic_Renaming_Declaration
2991 and then Nkind (Name (N)) = N_Expanded_Name
2992 and then Is_Generic_Instance (Entity (Prefix (Name (N))))
2993 and then Is_Generic_Unit (Old_E)
2996 ("renamed generic unit must be a library unit", Name (N));
2998 elsif Is_Package_Or_Generic_Package (Old_E) then
3000 -- Inherit categorization flags
3002 New_E := Defining_Entity (N);
3003 Set_Is_Pure (New_E, Is_Pure (Old_E));
3004 Set_Is_Preelaborated (New_E, Is_Preelaborated (Old_E));
3005 Set_Is_Remote_Call_Interface (New_E,
3006 Is_Remote_Call_Interface (Old_E));
3007 Set_Is_Remote_Types (New_E, Is_Remote_Types (Old_E));
3008 Set_Is_Shared_Passive (New_E, Is_Shared_Passive (Old_E));
3010 end Check_Library_Unit_Renaming;
3016 procedure End_Scope is
3022 Id := First_Entity (Current_Scope);
3023 while Present (Id) loop
3024 -- An entity in the current scope is not necessarily the first one
3025 -- on its homonym chain. Find its predecessor if any,
3026 -- If it is an internal entity, it will not be in the visibility
3027 -- chain altogether, and there is nothing to unchain.
3029 if Id /= Current_Entity (Id) then
3030 Prev := Current_Entity (Id);
3031 while Present (Prev)
3032 and then Present (Homonym (Prev))
3033 and then Homonym (Prev) /= Id
3035 Prev := Homonym (Prev);
3038 -- Skip to end of loop if Id is not in the visibility chain
3040 if No (Prev) or else Homonym (Prev) /= Id then
3048 Set_Is_Immediately_Visible (Id, False);
3050 Outer := Homonym (Id);
3051 while Present (Outer) and then Scope (Outer) = Current_Scope loop
3052 Outer := Homonym (Outer);
3055 -- Reset homonym link of other entities, but do not modify link
3056 -- between entities in current scope, so that the back-end can have
3057 -- a proper count of local overloadings.
3060 Set_Name_Entity_Id (Chars (Id), Outer);
3062 elsif Scope (Prev) /= Scope (Id) then
3063 Set_Homonym (Prev, Outer);
3070 -- If the scope generated freeze actions, place them before the
3071 -- current declaration and analyze them. Type declarations and
3072 -- the bodies of initialization procedures can generate such nodes.
3073 -- We follow the parent chain until we reach a list node, which is
3074 -- the enclosing list of declarations. If the list appears within
3075 -- a protected definition, move freeze nodes outside the protected
3079 (Scope_Stack.Table (Scope_Stack.Last).Pending_Freeze_Actions)
3083 L : constant List_Id := Scope_Stack.Table
3084 (Scope_Stack.Last).Pending_Freeze_Actions;
3087 if Is_Itype (Current_Scope) then
3088 Decl := Associated_Node_For_Itype (Current_Scope);
3090 Decl := Parent (Current_Scope);
3095 while not (Is_List_Member (Decl))
3096 or else Nkind_In (Parent (Decl), N_Protected_Definition,
3099 Decl := Parent (Decl);
3102 Insert_List_Before_And_Analyze (Decl, L);
3111 ---------------------
3112 -- End_Use_Clauses --
3113 ---------------------
3115 procedure End_Use_Clauses (Clause : Node_Id) is
3119 -- Remove Use_Type clauses first, because they affect the
3120 -- visibility of operators in subsequent used packages.
3123 while Present (U) loop
3124 if Nkind (U) = N_Use_Type_Clause then
3128 Next_Use_Clause (U);
3132 while Present (U) loop
3133 if Nkind (U) = N_Use_Package_Clause then
3134 End_Use_Package (U);
3137 Next_Use_Clause (U);
3139 end End_Use_Clauses;
3141 ---------------------
3142 -- End_Use_Package --
3143 ---------------------
3145 procedure End_Use_Package (N : Node_Id) is
3146 Pack_Name : Node_Id;
3151 function Is_Primitive_Operator
3153 F : Entity_Id) return Boolean;
3154 -- Check whether Op is a primitive operator of a use-visible type
3156 ---------------------------
3157 -- Is_Primitive_Operator --
3158 ---------------------------
3160 function Is_Primitive_Operator
3162 F : Entity_Id) return Boolean
3164 T : constant Entity_Id := Etype (F);
3167 and then Scope (T) = Scope (Op);
3168 end Is_Primitive_Operator;
3170 -- Start of processing for End_Use_Package
3173 Pack_Name := First (Names (N));
3174 while Present (Pack_Name) loop
3176 -- Test that Pack_Name actually denotes a package before processing
3178 if Is_Entity_Name (Pack_Name)
3179 and then Ekind (Entity (Pack_Name)) = E_Package
3181 Pack := Entity (Pack_Name);
3183 if In_Open_Scopes (Pack) then
3186 elsif not Redundant_Use (Pack_Name) then
3187 Set_In_Use (Pack, False);
3188 Set_Current_Use_Clause (Pack, Empty);
3190 Id := First_Entity (Pack);
3191 while Present (Id) loop
3193 -- Preserve use-visibility of operators that are primitive
3194 -- operators of a type that is use-visible through an active
3197 if Nkind (Id) = N_Defining_Operator_Symbol
3199 (Is_Primitive_Operator (Id, First_Formal (Id))
3201 (Present (Next_Formal (First_Formal (Id)))
3203 Is_Primitive_Operator
3204 (Id, Next_Formal (First_Formal (Id)))))
3209 Set_Is_Potentially_Use_Visible (Id, False);
3212 if Is_Private_Type (Id)
3213 and then Present (Full_View (Id))
3215 Set_Is_Potentially_Use_Visible (Full_View (Id), False);
3221 if Present (Renamed_Object (Pack)) then
3222 Set_In_Use (Renamed_Object (Pack), False);
3223 Set_Current_Use_Clause (Renamed_Object (Pack), Empty);
3226 if Chars (Pack) = Name_System
3227 and then Scope (Pack) = Standard_Standard
3228 and then Present_System_Aux
3230 Id := First_Entity (System_Aux_Id);
3231 while Present (Id) loop
3232 Set_Is_Potentially_Use_Visible (Id, False);
3234 if Is_Private_Type (Id)
3235 and then Present (Full_View (Id))
3237 Set_Is_Potentially_Use_Visible (Full_View (Id), False);
3243 Set_In_Use (System_Aux_Id, False);
3247 Set_Redundant_Use (Pack_Name, False);
3254 if Present (Hidden_By_Use_Clause (N)) then
3255 Elmt := First_Elmt (Hidden_By_Use_Clause (N));
3256 while Present (Elmt) loop
3257 Set_Is_Immediately_Visible (Node (Elmt));
3261 Set_Hidden_By_Use_Clause (N, No_Elist);
3263 end End_Use_Package;
3269 procedure End_Use_Type (N : Node_Id) is
3276 Id := First (Subtype_Marks (N));
3277 while Present (Id) loop
3279 -- A call to rtsfind may occur while analyzing a use_type clause,
3280 -- in which case the type marks are not resolved yet, and there is
3281 -- nothing to remove.
3283 if not Is_Entity_Name (Id)
3284 or else No (Entity (Id))
3292 or else From_With_Type (T)
3296 -- Note that the use_Type clause may mention a subtype of the type
3297 -- whose primitive operations have been made visible. Here as
3298 -- elsewhere, it is the base type that matters for visibility.
3300 elsif In_Open_Scopes (Scope (Base_Type (T))) then
3303 elsif not Redundant_Use (Id) then
3304 Set_In_Use (T, False);
3305 Set_In_Use (Base_Type (T), False);
3306 Set_Current_Use_Clause (T, Empty);
3307 Set_Current_Use_Clause (Base_Type (T), Empty);
3308 Op_List := Collect_Primitive_Operations (T);
3310 Elmt := First_Elmt (Op_List);
3311 while Present (Elmt) loop
3312 if Nkind (Node (Elmt)) = N_Defining_Operator_Symbol then
3313 Set_Is_Potentially_Use_Visible (Node (Elmt), False);
3325 ----------------------
3326 -- Find_Direct_Name --
3327 ----------------------
3329 procedure Find_Direct_Name (N : Node_Id) is
3334 Inst : Entity_Id := Empty;
3335 -- Enclosing instance, if any
3337 Homonyms : Entity_Id;
3338 -- Saves start of homonym chain
3340 Nvis_Entity : Boolean;
3341 -- Set True to indicate that at there is at least one entity on the
3342 -- homonym chain which, while not visible, is visible enough from the
3343 -- user point of view to warrant an error message of "not visible"
3344 -- rather than undefined.
3346 Nvis_Is_Private_Subprg : Boolean := False;
3347 -- Ada 2005 (AI-262): Set True to indicate that a form of Beaujolais
3348 -- effect concerning library subprograms has been detected. Used to
3349 -- generate the precise error message.
3351 function From_Actual_Package (E : Entity_Id) return Boolean;
3352 -- Returns true if the entity is declared in a package that is
3353 -- an actual for a formal package of the current instance. Such an
3354 -- entity requires special handling because it may be use-visible
3355 -- but hides directly visible entities defined outside the instance.
3357 function Is_Actual_Parameter return Boolean;
3358 -- This function checks if the node N is an identifier that is an actual
3359 -- parameter of a procedure call. If so it returns True, otherwise it
3360 -- return False. The reason for this check is that at this stage we do
3361 -- not know what procedure is being called if the procedure might be
3362 -- overloaded, so it is premature to go setting referenced flags or
3363 -- making calls to Generate_Reference. We will wait till Resolve_Actuals
3364 -- for that processing
3366 function Known_But_Invisible (E : Entity_Id) return Boolean;
3367 -- This function determines whether the entity E (which is not
3368 -- visible) can reasonably be considered to be known to the writer
3369 -- of the reference. This is a heuristic test, used only for the
3370 -- purposes of figuring out whether we prefer to complain that an
3371 -- entity is undefined or invisible (and identify the declaration
3372 -- of the invisible entity in the latter case). The point here is
3373 -- that we don't want to complain that something is invisible and
3374 -- then point to something entirely mysterious to the writer.
3376 procedure Nvis_Messages;
3377 -- Called if there are no visible entries for N, but there is at least
3378 -- one non-directly visible, or hidden declaration. This procedure
3379 -- outputs an appropriate set of error messages.
3381 procedure Undefined (Nvis : Boolean);
3382 -- This function is called if the current node has no corresponding
3383 -- visible entity or entities. The value set in Msg indicates whether
3384 -- an error message was generated (multiple error messages for the
3385 -- same variable are generally suppressed, see body for details).
3386 -- Msg is True if an error message was generated, False if not. This
3387 -- value is used by the caller to determine whether or not to output
3388 -- additional messages where appropriate. The parameter is set False
3389 -- to get the message "X is undefined", and True to get the message
3390 -- "X is not visible".
3392 -------------------------
3393 -- From_Actual_Package --
3394 -------------------------
3396 function From_Actual_Package (E : Entity_Id) return Boolean is
3397 Scop : constant Entity_Id := Scope (E);
3401 if not In_Instance then
3404 Inst := Current_Scope;
3405 while Present (Inst)
3406 and then Ekind (Inst) /= E_Package
3407 and then not Is_Generic_Instance (Inst)
3409 Inst := Scope (Inst);
3416 Act := First_Entity (Inst);
3417 while Present (Act) loop
3418 if Ekind (Act) = E_Package then
3420 -- Check for end of actuals list
3422 if Renamed_Object (Act) = Inst then
3425 elsif Present (Associated_Formal_Package (Act))
3426 and then Renamed_Object (Act) = Scop
3428 -- Entity comes from (instance of) formal package
3443 end From_Actual_Package;
3445 -------------------------
3446 -- Is_Actual_Parameter --
3447 -------------------------
3449 function Is_Actual_Parameter return Boolean is
3452 Nkind (N) = N_Identifier
3454 (Nkind (Parent (N)) = N_Procedure_Call_Statement
3456 (Nkind (Parent (N)) = N_Parameter_Association
3457 and then N = Explicit_Actual_Parameter (Parent (N))
3458 and then Nkind (Parent (Parent (N))) =
3459 N_Procedure_Call_Statement));
3460 end Is_Actual_Parameter;
3462 -------------------------
3463 -- Known_But_Invisible --
3464 -------------------------
3466 function Known_But_Invisible (E : Entity_Id) return Boolean is
3467 Fname : File_Name_Type;
3470 -- Entities in Standard are always considered to be known
3472 if Sloc (E) <= Standard_Location then
3475 -- An entity that does not come from source is always considered
3476 -- to be unknown, since it is an artifact of code expansion.
3478 elsif not Comes_From_Source (E) then
3481 -- In gnat internal mode, we consider all entities known
3483 elsif GNAT_Mode then
3487 -- Here we have an entity that is not from package Standard, and
3488 -- which comes from Source. See if it comes from an internal file.
3490 Fname := Unit_File_Name (Get_Source_Unit (E));
3492 -- Case of from internal file
3494 if Is_Internal_File_Name (Fname) then
3496 -- Private part entities in internal files are never considered
3497 -- to be known to the writer of normal application code.
3499 if Is_Hidden (E) then
3503 -- Entities from System packages other than System and
3504 -- System.Storage_Elements are not considered to be known.
3505 -- System.Auxxxx files are also considered known to the user.
3507 -- Should refine this at some point to generally distinguish
3508 -- between known and unknown internal files ???
3510 Get_Name_String (Fname);
3515 Name_Buffer (1 .. 2) /= "s-"
3517 Name_Buffer (3 .. 8) = "stoele"
3519 Name_Buffer (3 .. 5) = "aux";
3521 -- If not an internal file, then entity is definitely known,
3522 -- even if it is in a private part (the message generated will
3523 -- note that it is in a private part)
3528 end Known_But_Invisible;
3534 procedure Nvis_Messages is
3535 Comp_Unit : Node_Id;
3537 Hidden : Boolean := False;
3541 -- Ada 2005 (AI-262): Generate a precise error concerning the
3542 -- Beaujolais effect that was previously detected
3544 if Nvis_Is_Private_Subprg then
3546 pragma Assert (Nkind (E2) = N_Defining_Identifier
3547 and then Ekind (E2) = E_Function
3548 and then Scope (E2) = Standard_Standard
3549 and then Has_Private_With (E2));
3551 -- Find the sloc corresponding to the private with'ed unit
3553 Comp_Unit := Cunit (Current_Sem_Unit);
3554 Error_Msg_Sloc := No_Location;
3556 Item := First (Context_Items (Comp_Unit));
3557 while Present (Item) loop
3558 if Nkind (Item) = N_With_Clause
3559 and then Private_Present (Item)
3560 and then Entity (Name (Item)) = E2
3562 Error_Msg_Sloc := Sloc (Item);
3569 pragma Assert (Error_Msg_Sloc /= No_Location);
3571 Error_Msg_N ("(Ada 2005): hidden by private with clause #", N);
3575 Undefined (Nvis => True);
3579 -- First loop does hidden declarations
3582 while Present (Ent) loop
3583 if Is_Potentially_Use_Visible (Ent) then
3585 Error_Msg_N ("multiple use clauses cause hiding!", N);
3589 Error_Msg_Sloc := Sloc (Ent);
3590 Error_Msg_N ("hidden declaration#!", N);
3593 Ent := Homonym (Ent);
3596 -- If we found hidden declarations, then that's enough, don't
3597 -- bother looking for non-visible declarations as well.
3603 -- Second loop does non-directly visible declarations
3606 while Present (Ent) loop
3607 if not Is_Potentially_Use_Visible (Ent) then
3609 -- Do not bother the user with unknown entities
3611 if not Known_But_Invisible (Ent) then
3615 Error_Msg_Sloc := Sloc (Ent);
3617 -- Output message noting that there is a non-visible
3618 -- declaration, distinguishing the private part case.
3620 if Is_Hidden (Ent) then
3621 Error_Msg_N ("non-visible (private) declaration#!", N);
3623 Error_Msg_N ("non-visible declaration#!", N);
3625 if Is_Compilation_Unit (Ent)
3627 Nkind (Parent (Parent (N))) = N_Use_Package_Clause
3629 Error_Msg_Qual_Level := 99;
3630 Error_Msg_NE ("\\missing `WITH &;`", N, Ent);
3631 Error_Msg_Qual_Level := 0;
3635 -- Set entity and its containing package as referenced. We
3636 -- can't be sure of this, but this seems a better choice
3637 -- to avoid unused entity messages.
3639 if Comes_From_Source (Ent) then
3640 Set_Referenced (Ent);
3641 Set_Referenced (Cunit_Entity (Get_Source_Unit (Ent)));
3646 Ent := Homonym (Ent);
3655 procedure Undefined (Nvis : Boolean) is
3656 Emsg : Error_Msg_Id;
3659 -- We should never find an undefined internal name. If we do, then
3660 -- see if we have previous errors. If so, ignore on the grounds that
3661 -- it is probably a cascaded message (e.g. a block label from a badly
3662 -- formed block). If no previous errors, then we have a real internal
3663 -- error of some kind so raise an exception.
3665 if Is_Internal_Name (Chars (N)) then
3666 if Total_Errors_Detected /= 0 then
3669 raise Program_Error;
3673 -- A very specialized error check, if the undefined variable is
3674 -- a case tag, and the case type is an enumeration type, check
3675 -- for a possible misspelling, and if so, modify the identifier
3677 -- Named aggregate should also be handled similarly ???
3679 if Nkind (N) = N_Identifier
3680 and then Nkind (Parent (N)) = N_Case_Statement_Alternative
3683 Case_Stm : constant Node_Id := Parent (Parent (N));
3684 Case_Typ : constant Entity_Id := Etype (Expression (Case_Stm));
3689 if Is_Enumeration_Type (Case_Typ)
3690 and then not Is_Standard_Character_Type (Case_Typ)
3692 Lit := First_Literal (Case_Typ);
3693 Get_Name_String (Chars (Lit));
3695 if Chars (Lit) /= Chars (N)
3696 and then Is_Bad_Spelling_Of (Chars (N), Chars (Lit)) then
3697 Error_Msg_Node_2 := Lit;
3699 ("& is undefined, assume misspelling of &", N);
3700 Rewrite (N, New_Occurrence_Of (Lit, Sloc (N)));
3704 Lit := Next_Literal (Lit);
3709 -- Normal processing
3711 Set_Entity (N, Any_Id);
3712 Set_Etype (N, Any_Type);
3714 -- We use the table Urefs to keep track of entities for which we
3715 -- have issued errors for undefined references. Multiple errors
3716 -- for a single name are normally suppressed, however we modify
3717 -- the error message to alert the programmer to this effect.
3719 for J in Urefs.First .. Urefs.Last loop
3720 if Chars (N) = Chars (Urefs.Table (J).Node) then
3721 if Urefs.Table (J).Err /= No_Error_Msg
3722 and then Sloc (N) /= Urefs.Table (J).Loc
3724 Error_Msg_Node_1 := Urefs.Table (J).Node;
3726 if Urefs.Table (J).Nvis then
3727 Change_Error_Text (Urefs.Table (J).Err,
3728 "& is not visible (more references follow)");
3730 Change_Error_Text (Urefs.Table (J).Err,
3731 "& is undefined (more references follow)");
3734 Urefs.Table (J).Err := No_Error_Msg;
3737 -- Although we will set Msg False, and thus suppress the
3738 -- message, we also set Error_Posted True, to avoid any
3739 -- cascaded messages resulting from the undefined reference.
3742 Set_Error_Posted (N, True);
3747 -- If entry not found, this is first undefined occurrence
3750 Error_Msg_N ("& is not visible!", N);
3754 Error_Msg_N ("& is undefined!", N);
3757 -- A very bizarre special check, if the undefined identifier
3758 -- is put or put_line, then add a special error message (since
3759 -- this is a very common error for beginners to make).
3761 if Chars (N) = Name_Put or else Chars (N) = Name_Put_Line then
3763 ("\\possible missing `WITH Ada.Text_'I'O; " &
3764 "USE Ada.Text_'I'O`!", N);
3766 -- Another special check if N is the prefix of a selected
3767 -- component which is a known unit, add message complaining
3768 -- about missing with for this unit.
3770 elsif Nkind (Parent (N)) = N_Selected_Component
3771 and then N = Prefix (Parent (N))
3772 and then Is_Known_Unit (Parent (N))
3774 Error_Msg_Node_2 := Selector_Name (Parent (N));
3775 Error_Msg_N ("\\missing `WITH &.&;`", Prefix (Parent (N)));
3778 -- Now check for possible misspellings
3782 Ematch : Entity_Id := Empty;
3784 Last_Name_Id : constant Name_Id :=
3785 Name_Id (Nat (First_Name_Id) +
3786 Name_Entries_Count - 1);
3789 for Nam in First_Name_Id .. Last_Name_Id loop
3790 E := Get_Name_Entity_Id (Nam);
3793 and then (Is_Immediately_Visible (E)
3795 Is_Potentially_Use_Visible (E))
3797 if Is_Bad_Spelling_Of (Chars (N), Nam) then
3804 if Present (Ematch) then
3805 Error_Msg_NE ("\possible misspelling of&", N, Ematch);
3810 -- Make entry in undefined references table unless the full errors
3811 -- switch is set, in which case by refraining from generating the
3812 -- table entry, we guarantee that we get an error message for every
3813 -- undefined reference.
3815 if not All_Errors_Mode then
3826 -- Start of processing for Find_Direct_Name
3829 -- If the entity pointer is already set, this is an internal node, or
3830 -- a node that is analyzed more than once, after a tree modification.
3831 -- In such a case there is no resolution to perform, just set the type.
3833 if Present (Entity (N)) then
3834 if Is_Type (Entity (N)) then
3835 Set_Etype (N, Entity (N));
3839 Entyp : constant Entity_Id := Etype (Entity (N));
3842 -- One special case here. If the Etype field is already set,
3843 -- and references the packed array type corresponding to the
3844 -- etype of the referenced entity, then leave it alone. This
3845 -- happens for trees generated from Exp_Pakd, where expressions
3846 -- can be deliberately "mis-typed" to the packed array type.
3848 if Is_Array_Type (Entyp)
3849 and then Is_Packed (Entyp)
3850 and then Present (Etype (N))
3851 and then Etype (N) = Packed_Array_Type (Entyp)
3855 -- If not that special case, then just reset the Etype
3858 Set_Etype (N, Etype (Entity (N)));
3866 -- Here if Entity pointer was not set, we need full visibility analysis
3867 -- First we generate debugging output if the debug E flag is set.
3869 if Debug_Flag_E then
3870 Write_Str ("Looking for ");
3871 Write_Name (Chars (N));
3875 Homonyms := Current_Entity (N);
3876 Nvis_Entity := False;
3879 while Present (E) loop
3881 -- If entity is immediately visible or potentially use visible, then
3882 -- process the entity and we are done.
3884 if Is_Immediately_Visible (E) then
3885 goto Immediately_Visible_Entity;
3887 elsif Is_Potentially_Use_Visible (E) then
3888 goto Potentially_Use_Visible_Entity;
3890 -- Note if a known but invisible entity encountered
3892 elsif Known_But_Invisible (E) then
3893 Nvis_Entity := True;
3896 -- Move to next entity in chain and continue search
3901 -- If no entries on homonym chain that were potentially visible,
3902 -- and no entities reasonably considered as non-visible, then
3903 -- we have a plain undefined reference, with no additional
3904 -- explanation required!
3906 if not Nvis_Entity then
3907 Undefined (Nvis => False);
3909 -- Otherwise there is at least one entry on the homonym chain that
3910 -- is reasonably considered as being known and non-visible.
3918 -- Processing for a potentially use visible entry found. We must search
3919 -- the rest of the homonym chain for two reasons. First, if there is a
3920 -- directly visible entry, then none of the potentially use-visible
3921 -- entities are directly visible (RM 8.4(10)). Second, we need to check
3922 -- for the case of multiple potentially use-visible entries hiding one
3923 -- another and as a result being non-directly visible (RM 8.4(11)).
3925 <<Potentially_Use_Visible_Entity>> declare
3926 Only_One_Visible : Boolean := True;
3927 All_Overloadable : Boolean := Is_Overloadable (E);
3931 while Present (E2) loop
3932 if Is_Immediately_Visible (E2) then
3934 -- If the use-visible entity comes from the actual for a
3935 -- formal package, it hides a directly visible entity from
3936 -- outside the instance.
3938 if From_Actual_Package (E)
3939 and then Scope_Depth (E2) < Scope_Depth (Inst)
3944 goto Immediately_Visible_Entity;
3947 elsif Is_Potentially_Use_Visible (E2) then
3948 Only_One_Visible := False;
3949 All_Overloadable := All_Overloadable and Is_Overloadable (E2);
3951 -- Ada 2005 (AI-262): Protect against a form of Beaujolais effect
3952 -- that can occur in private_with clauses. Example:
3955 -- private with B; package A is
3956 -- package C is function B return Integer;
3958 -- V1 : Integer := B;
3959 -- private function B return Integer;
3960 -- V2 : Integer := B;
3963 -- V1 resolves to A.B, but V2 resolves to library unit B
3965 elsif Ekind (E2) = E_Function
3966 and then Scope (E2) = Standard_Standard
3967 and then Has_Private_With (E2)
3969 Only_One_Visible := False;
3970 All_Overloadable := False;
3971 Nvis_Is_Private_Subprg := True;
3978 -- On falling through this loop, we have checked that there are no
3979 -- immediately visible entities. Only_One_Visible is set if exactly
3980 -- one potentially use visible entity exists. All_Overloadable is
3981 -- set if all the potentially use visible entities are overloadable.
3982 -- The condition for legality is that either there is one potentially
3983 -- use visible entity, or if there is more than one, then all of them
3984 -- are overloadable.
3986 if Only_One_Visible or All_Overloadable then
3989 -- If there is more than one potentially use-visible entity and at
3990 -- least one of them non-overloadable, we have an error (RM 8.4(11).
3991 -- Note that E points to the first such entity on the homonym list.
3992 -- Special case: if one of the entities is declared in an actual
3993 -- package, it was visible in the generic, and takes precedence over
3994 -- other entities that are potentially use-visible. Same if it is
3995 -- declared in a local instantiation of the current instance.
4000 -- Find current instance
4002 Inst := Current_Scope;
4003 while Present (Inst)
4004 and then Inst /= Standard_Standard
4006 if Is_Generic_Instance (Inst) then
4010 Inst := Scope (Inst);
4014 while Present (E2) loop
4015 if From_Actual_Package (E2)
4017 (Is_Generic_Instance (Scope (E2))
4018 and then Scope_Depth (Scope (E2)) > Scope_Depth (Inst))
4031 Is_Predefined_File_Name (Unit_File_Name (Current_Sem_Unit))
4033 -- A use-clause in the body of a system file creates conflict
4034 -- with some entity in a user scope, while rtsfind is active.
4035 -- Keep only the entity coming from another predefined unit.
4038 while Present (E2) loop
4039 if Is_Predefined_File_Name
4040 (Unit_File_Name (Get_Source_Unit (Sloc (E2))))
4049 -- Entity must exist because predefined unit is correct
4051 raise Program_Error;
4060 -- Come here with E set to the first immediately visible entity on
4061 -- the homonym chain. This is the one we want unless there is another
4062 -- immediately visible entity further on in the chain for an inner
4063 -- scope (RM 8.3(8)).
4065 <<Immediately_Visible_Entity>> declare
4070 -- Find scope level of initial entity. When compiling through
4071 -- Rtsfind, the previous context is not completely invisible, and
4072 -- an outer entity may appear on the chain, whose scope is below
4073 -- the entry for Standard that delimits the current scope stack.
4074 -- Indicate that the level for this spurious entry is outside of
4075 -- the current scope stack.
4077 Level := Scope_Stack.Last;
4079 Scop := Scope_Stack.Table (Level).Entity;
4080 exit when Scop = Scope (E);
4082 exit when Scop = Standard_Standard;
4085 -- Now search remainder of homonym chain for more inner entry
4086 -- If the entity is Standard itself, it has no scope, and we
4087 -- compare it with the stack entry directly.
4090 while Present (E2) loop
4091 if Is_Immediately_Visible (E2) then
4093 -- If a generic package contains a local declaration that
4094 -- has the same name as the generic, there may be a visibility
4095 -- conflict in an instance, where the local declaration must
4096 -- also hide the name of the corresponding package renaming.
4097 -- We check explicitly for a package declared by a renaming,
4098 -- whose renamed entity is an instance that is on the scope
4099 -- stack, and that contains a homonym in the same scope. Once
4100 -- we have found it, we know that the package renaming is not
4101 -- immediately visible, and that the identifier denotes the
4102 -- other entity (and its homonyms if overloaded).
4104 if Scope (E) = Scope (E2)
4105 and then Ekind (E) = E_Package
4106 and then Present (Renamed_Object (E))
4107 and then Is_Generic_Instance (Renamed_Object (E))
4108 and then In_Open_Scopes (Renamed_Object (E))
4109 and then Comes_From_Source (N)
4111 Set_Is_Immediately_Visible (E, False);
4115 for J in Level + 1 .. Scope_Stack.Last loop
4116 if Scope_Stack.Table (J).Entity = Scope (E2)
4117 or else Scope_Stack.Table (J).Entity = E2
4130 -- At the end of that loop, E is the innermost immediately
4131 -- visible entity, so we are all set.
4134 -- Come here with entity found, and stored in E
4138 -- When distribution features are available (Get_PCS_Name /=
4139 -- Name_No_DSA), a remote access-to-subprogram type is converted
4140 -- into a record type holding whatever information is needed to
4141 -- perform a remote call on an RCI subprogram. In that case we
4142 -- rewrite any occurrence of the RAS type into the equivalent record
4143 -- type here. 'Access attribute references and RAS dereferences are
4144 -- then implemented using specific TSSs. However when distribution is
4145 -- not available (case of Get_PCS_Name = Name_No_DSA), we bypass the
4146 -- generation of these TSSs, and we must keep the RAS type in its
4147 -- original access-to-subprogram form (since all calls through a
4148 -- value of such type will be local anyway in the absence of a PCS).
4150 if Comes_From_Source (N)
4151 and then Is_Remote_Access_To_Subprogram_Type (E)
4152 and then Expander_Active
4153 and then Get_PCS_Name /= Name_No_DSA
4156 New_Occurrence_Of (Equivalent_Type (E), Sloc (N)));
4161 -- Why no Style_Check here???
4166 Set_Etype (N, Get_Full_View (Etype (E)));
4169 if Debug_Flag_E then
4170 Write_Str (" found ");
4171 Write_Entity_Info (E, " ");
4174 -- If the Ekind of the entity is Void, it means that all homonyms
4175 -- are hidden from all visibility (RM 8.3(5,14-20)). However, this
4176 -- test is skipped if the current scope is a record and the name is
4177 -- a pragma argument expression (case of Atomic and Volatile pragmas
4178 -- and possibly other similar pragmas added later, which are allowed
4179 -- to reference components in the current record).
4181 if Ekind (E) = E_Void
4183 (not Is_Record_Type (Current_Scope)
4184 or else Nkind (Parent (N)) /= N_Pragma_Argument_Association)
4186 Premature_Usage (N);
4188 -- If the entity is overloadable, collect all interpretations of the
4189 -- name for subsequent overload resolution. We optimize a bit here to
4190 -- do this only if we have an overloadable entity that is not on its
4191 -- own on the homonym chain.
4193 elsif Is_Overloadable (E)
4194 and then (Present (Homonym (E)) or else Current_Entity (N) /= E)
4196 Collect_Interps (N);
4198 -- If no homonyms were visible, the entity is unambiguous
4200 if not Is_Overloaded (N) then
4201 if not Is_Actual_Parameter then
4202 Generate_Reference (E, N);
4206 -- Case of non-overloadable entity, set the entity providing that
4207 -- we do not have the case of a discriminant reference within a
4208 -- default expression. Such references are replaced with the
4209 -- corresponding discriminal, which is the formal corresponding to
4210 -- to the discriminant in the initialization procedure.
4213 -- Entity is unambiguous, indicate that it is referenced here
4215 -- For a renaming of an object, always generate simple reference,
4216 -- we don't try to keep track of assignments in this case.
4218 if Is_Object (E) and then Present (Renamed_Object (E)) then
4219 Generate_Reference (E, N);
4221 -- If the renamed entity is a private protected component,
4222 -- reference the original component as well. This needs to be
4223 -- done because the private renamings are installed before any
4224 -- analysis has occurred. Reference to a private component will
4225 -- resolve to the renaming and the original component will be
4226 -- left unreferenced, hence the following.
4228 if Is_Prival (E) then
4229 Generate_Reference (Prival_Link (E), N);
4232 -- One odd case is that we do not want to set the Referenced flag
4233 -- if the entity is a label, and the identifier is the label in
4234 -- the source, since this is not a reference from the point of
4235 -- view of the user.
4237 elsif Nkind (Parent (N)) = N_Label then
4239 R : constant Boolean := Referenced (E);
4242 -- Generate reference unless this is an actual parameter
4243 -- (see comment below)
4245 if Is_Actual_Parameter then
4246 Generate_Reference (E, N);
4247 Set_Referenced (E, R);
4251 -- Normal case, not a label: generate reference
4253 -- ??? It is too early to generate a reference here even if
4254 -- the entity is unambiguous, because the tree is not
4255 -- sufficiently typed at this point for Generate_Reference to
4256 -- determine whether this reference modifies the denoted object
4257 -- (because implicit dereferences cannot be identified prior to
4258 -- full type resolution).
4260 -- The Is_Actual_Parameter routine takes care of one of these
4261 -- cases but there are others probably ???
4264 if not Is_Actual_Parameter then
4265 Generate_Reference (E, N);
4268 Check_Nested_Access (E);
4271 -- Set Entity, with style check if need be. For a discriminant
4272 -- reference, replace by the corresponding discriminal, i.e. the
4273 -- parameter of the initialization procedure that corresponds to
4274 -- the discriminant. If this replacement is being performed, there
4275 -- is no style check to perform.
4277 -- This replacement must not be done if we are currently
4278 -- processing a generic spec or body, because the discriminal
4279 -- has not been not generated in this case.
4281 -- The replacement is also skipped if we are in special
4282 -- spec-expression mode. Why is this skipped in this case ???
4284 if not In_Spec_Expression
4285 or else Ekind (E) /= E_Discriminant
4286 or else Inside_A_Generic
4288 Set_Entity_With_Style_Check (N, E);
4290 -- The replacement is not done either for a task discriminant that
4291 -- appears in a default expression of an entry parameter. See
4292 -- Expand_Discriminant in exp_ch2 for details on their handling.
4294 elsif Is_Concurrent_Type (Scope (E)) then
4301 and then not Nkind_In (P, N_Parameter_Specification,
4302 N_Component_Declaration)
4308 and then Nkind (P) = N_Parameter_Specification
4312 Set_Entity (N, Discriminal (E));
4316 -- Otherwise, this is a discriminant in a context in which
4317 -- it is a reference to the corresponding parameter of the
4318 -- init proc for the enclosing type.
4321 Set_Entity (N, Discriminal (E));
4325 end Find_Direct_Name;
4327 ------------------------
4328 -- Find_Expanded_Name --
4329 ------------------------
4331 -- This routine searches the homonym chain of the entity until it finds
4332 -- an entity declared in the scope denoted by the prefix. If the entity
4333 -- is private, it may nevertheless be immediately visible, if we are in
4334 -- the scope of its declaration.
4336 procedure Find_Expanded_Name (N : Node_Id) is
4337 Selector : constant Node_Id := Selector_Name (N);
4338 Candidate : Entity_Id := Empty;
4344 P_Name := Entity (Prefix (N));
4347 -- If the prefix is a renamed package, look for the entity in the
4348 -- original package.
4350 if Ekind (P_Name) = E_Package
4351 and then Present (Renamed_Object (P_Name))
4353 P_Name := Renamed_Object (P_Name);
4355 -- Rewrite node with entity field pointing to renamed object
4357 Rewrite (Prefix (N), New_Copy (Prefix (N)));
4358 Set_Entity (Prefix (N), P_Name);
4360 -- If the prefix is an object of a concurrent type, look for
4361 -- the entity in the associated task or protected type.
4363 elsif Is_Concurrent_Type (Etype (P_Name)) then
4364 P_Name := Etype (P_Name);
4367 Id := Current_Entity (Selector);
4370 Is_New_Candidate : Boolean;
4373 while Present (Id) loop
4374 if Scope (Id) = P_Name then
4376 Is_New_Candidate := True;
4378 -- Ada 2005 (AI-217): Handle shadow entities associated with types
4379 -- declared in limited-withed nested packages. We don't need to
4380 -- handle E_Incomplete_Subtype entities because the entities in
4381 -- the limited view are always E_Incomplete_Type entities (see
4382 -- Build_Limited_Views). Regarding the expression used to evaluate
4383 -- the scope, it is important to note that the limited view also
4384 -- has shadow entities associated nested packages. For this reason
4385 -- the correct scope of the entity is the scope of the real entity
4386 -- The non-limited view may itself be incomplete, in which case
4387 -- get the full view if available.
4389 elsif From_With_Type (Id)
4390 and then Is_Type (Id)
4391 and then Ekind (Id) = E_Incomplete_Type
4392 and then Present (Non_Limited_View (Id))
4393 and then Scope (Non_Limited_View (Id)) = P_Name
4395 Candidate := Get_Full_View (Non_Limited_View (Id));
4396 Is_New_Candidate := True;
4399 Is_New_Candidate := False;
4402 if Is_New_Candidate then
4403 if Is_Child_Unit (Id) then
4404 exit when Is_Visible_Child_Unit (Id)
4405 or else Is_Immediately_Visible (Id);
4408 exit when not Is_Hidden (Id)
4409 or else Is_Immediately_Visible (Id);
4418 and then (Ekind (P_Name) = E_Procedure
4420 Ekind (P_Name) = E_Function)
4421 and then Is_Generic_Instance (P_Name)
4423 -- Expanded name denotes entity in (instance of) generic subprogram.
4424 -- The entity may be in the subprogram instance, or may denote one of
4425 -- the formals, which is declared in the enclosing wrapper package.
4427 P_Name := Scope (P_Name);
4429 Id := Current_Entity (Selector);
4430 while Present (Id) loop
4431 exit when Scope (Id) = P_Name;
4436 if No (Id) or else Chars (Id) /= Chars (Selector) then
4437 Set_Etype (N, Any_Type);
4439 -- If we are looking for an entity defined in System, try to find it
4440 -- in the child package that may have been provided as an extension
4441 -- to System. The Extend_System pragma will have supplied the name of
4442 -- the extension, which may have to be loaded.
4444 if Chars (P_Name) = Name_System
4445 and then Scope (P_Name) = Standard_Standard
4446 and then Present (System_Extend_Unit)
4447 and then Present_System_Aux (N)
4449 Set_Entity (Prefix (N), System_Aux_Id);
4450 Find_Expanded_Name (N);
4453 elsif Nkind (Selector) = N_Operator_Symbol
4454 and then Has_Implicit_Operator (N)
4456 -- There is an implicit instance of the predefined operator in
4457 -- the given scope. The operator entity is defined in Standard.
4458 -- Has_Implicit_Operator makes the node into an Expanded_Name.
4462 elsif Nkind (Selector) = N_Character_Literal
4463 and then Has_Implicit_Character_Literal (N)
4465 -- If there is no literal defined in the scope denoted by the
4466 -- prefix, the literal may belong to (a type derived from)
4467 -- Standard_Character, for which we have no explicit literals.
4472 -- If the prefix is a single concurrent object, use its name in
4473 -- the error message, rather than that of the anonymous type.
4475 if Is_Concurrent_Type (P_Name)
4476 and then Is_Internal_Name (Chars (P_Name))
4478 Error_Msg_Node_2 := Entity (Prefix (N));
4480 Error_Msg_Node_2 := P_Name;
4483 if P_Name = System_Aux_Id then
4484 P_Name := Scope (P_Name);
4485 Set_Entity (Prefix (N), P_Name);
4488 if Present (Candidate) then
4490 -- If we know that the unit is a child unit we can give a more
4491 -- accurate error message.
4493 if Is_Child_Unit (Candidate) then
4495 -- If the candidate is a private child unit and we are in
4496 -- the visible part of a public unit, specialize the error
4497 -- message. There might be a private with_clause for it,
4498 -- but it is not currently active.
4500 if Is_Private_Descendant (Candidate)
4501 and then Ekind (Current_Scope) = E_Package
4502 and then not In_Private_Part (Current_Scope)
4503 and then not Is_Private_Descendant (Current_Scope)
4505 Error_Msg_N ("private child unit& is not visible here",
4508 -- Normal case where we have a missing with for a child unit
4511 Error_Msg_Qual_Level := 99;
4512 Error_Msg_NE ("missing `WITH &;`", Selector, Candidate);
4513 Error_Msg_Qual_Level := 0;
4516 -- Here we don't know that this is a child unit
4519 Error_Msg_NE ("& is not a visible entity of&", N, Selector);
4523 -- Within the instantiation of a child unit, the prefix may
4524 -- denote the parent instance, but the selector has the name
4525 -- of the original child. Find whether we are within the
4526 -- corresponding instance, and get the proper entity, which
4527 -- can only be an enclosing scope.
4530 and then In_Open_Scopes (P_Name)
4531 and then Is_Generic_Instance (P_Name)
4534 S : Entity_Id := Current_Scope;
4538 for J in reverse 0 .. Scope_Stack.Last loop
4539 S := Scope_Stack.Table (J).Entity;
4541 exit when S = Standard_Standard;
4543 if Ekind (S) = E_Function
4544 or else Ekind (S) = E_Package
4545 or else Ekind (S) = E_Procedure
4547 P := Generic_Parent (Specification
4548 (Unit_Declaration_Node (S)));
4551 and then Chars (Scope (P)) = Chars (O_Name)
4552 and then Chars (P) = Chars (Selector)
4563 -- If this is a selection from Ada, System or Interfaces, then
4564 -- we assume a missing with for the corresponding package.
4566 if Is_Known_Unit (N) then
4567 if not Error_Posted (N) then
4568 Error_Msg_Node_2 := Selector;
4569 Error_Msg_N ("missing `WITH &.&;`", Prefix (N));
4572 -- If this is a selection from a dummy package, then suppress
4573 -- the error message, of course the entity is missing if the
4574 -- package is missing!
4576 elsif Sloc (Error_Msg_Node_2) = No_Location then
4579 -- Here we have the case of an undefined component
4582 Error_Msg_NE ("& not declared in&", N, Selector);
4584 -- Check for misspelling of some entity in prefix
4586 Id := First_Entity (P_Name);
4587 while Present (Id) loop
4588 if Is_Bad_Spelling_Of (Chars (Id), Chars (Selector))
4589 and then not Is_Internal_Name (Chars (Id))
4592 ("possible misspelling of&", Selector, Id);
4599 -- Specialize the message if this may be an instantiation
4600 -- of a child unit that was not mentioned in the context.
4602 if Nkind (Parent (N)) = N_Package_Instantiation
4603 and then Is_Generic_Instance (Entity (Prefix (N)))
4604 and then Is_Compilation_Unit
4605 (Generic_Parent (Parent (Entity (Prefix (N)))))
4607 Error_Msg_Node_2 := Selector;
4608 Error_Msg_N ("\missing `WITH &.&;`", Prefix (N));
4618 if Comes_From_Source (N)
4619 and then Is_Remote_Access_To_Subprogram_Type (Id)
4620 and then Present (Equivalent_Type (Id))
4622 -- If we are not actually generating distribution code (i.e. the
4623 -- current PCS is the dummy non-distributed version), then the
4624 -- Equivalent_Type will be missing, and Id should be treated as
4625 -- a regular access-to-subprogram type.
4627 Id := Equivalent_Type (Id);
4628 Set_Chars (Selector, Chars (Id));
4631 -- Ada 2005 (AI-50217): Check usage of entities in limited withed units
4633 if Ekind (P_Name) = E_Package
4634 and then From_With_Type (P_Name)
4636 if From_With_Type (Id)
4637 or else Is_Type (Id)
4638 or else Ekind (Id) = E_Package
4643 ("limited withed package can only be used to access "
4644 & "incomplete types",
4649 if Is_Task_Type (P_Name)
4650 and then ((Ekind (Id) = E_Entry
4651 and then Nkind (Parent (N)) /= N_Attribute_Reference)
4653 (Ekind (Id) = E_Entry_Family
4655 Nkind (Parent (Parent (N))) /= N_Attribute_Reference))
4657 -- It is an entry call after all, either to the current task (which
4658 -- will deadlock) or to an enclosing task.
4660 Analyze_Selected_Component (N);
4664 Change_Selected_Component_To_Expanded_Name (N);
4666 -- Do style check and generate reference, but skip both steps if this
4667 -- entity has homonyms, since we may not have the right homonym set yet.
4668 -- The proper homonym will be set during the resolve phase.
4670 if Has_Homonym (Id) then
4673 Set_Entity_With_Style_Check (N, Id);
4674 Generate_Reference (Id, N);
4677 if Is_Type (Id) then
4680 Set_Etype (N, Get_Full_View (Etype (Id)));
4683 -- If the Ekind of the entity is Void, it means that all homonyms are
4684 -- hidden from all visibility (RM 8.3(5,14-20)).
4686 if Ekind (Id) = E_Void then
4687 Premature_Usage (N);
4689 elsif Is_Overloadable (Id)
4690 and then Present (Homonym (Id))
4693 H : Entity_Id := Homonym (Id);
4696 while Present (H) loop
4697 if Scope (H) = Scope (Id)
4700 or else Is_Immediately_Visible (H))
4702 Collect_Interps (N);
4709 -- If an extension of System is present, collect possible explicit
4710 -- overloadings declared in the extension.
4712 if Chars (P_Name) = Name_System
4713 and then Scope (P_Name) = Standard_Standard
4714 and then Present (System_Extend_Unit)
4715 and then Present_System_Aux (N)
4717 H := Current_Entity (Id);
4719 while Present (H) loop
4720 if Scope (H) = System_Aux_Id then
4721 Add_One_Interp (N, H, Etype (H));
4730 if Nkind (Selector_Name (N)) = N_Operator_Symbol
4731 and then Scope (Id) /= Standard_Standard
4733 -- In addition to user-defined operators in the given scope, there
4734 -- may be an implicit instance of the predefined operator. The
4735 -- operator (defined in Standard) is found in Has_Implicit_Operator,
4736 -- and added to the interpretations. Procedure Add_One_Interp will
4737 -- determine which hides which.
4739 if Has_Implicit_Operator (N) then
4743 end Find_Expanded_Name;
4745 -------------------------
4746 -- Find_Renamed_Entity --
4747 -------------------------
4749 function Find_Renamed_Entity
4753 Is_Actual : Boolean := False) return Entity_Id
4756 I1 : Interp_Index := 0; -- Suppress junk warnings
4762 function Enclosing_Instance return Entity_Id;
4763 -- If the renaming determines the entity for the default of a formal
4764 -- subprogram nested within another instance, choose the innermost
4765 -- candidate. This is because if the formal has a box, and we are within
4766 -- an enclosing instance where some candidate interpretations are local
4767 -- to this enclosing instance, we know that the default was properly
4768 -- resolved when analyzing the generic, so we prefer the local
4769 -- candidates to those that are external. This is not always the case
4770 -- but is a reasonable heuristic on the use of nested generics. The
4771 -- proper solution requires a full renaming model.
4773 function Is_Visible_Operation (Op : Entity_Id) return Boolean;
4774 -- If the renamed entity is an implicit operator, check whether it is
4775 -- visible because its operand type is properly visible. This check
4776 -- applies to explicit renamed entities that appear in the source in a
4777 -- renaming declaration or a formal subprogram instance, but not to
4778 -- default generic actuals with a name.
4780 function Report_Overload return Entity_Id;
4781 -- List possible interpretations, and specialize message in the
4782 -- case of a generic actual.
4784 function Within (Inner, Outer : Entity_Id) return Boolean;
4785 -- Determine whether a candidate subprogram is defined within the
4786 -- enclosing instance. If yes, it has precedence over outer candidates.
4788 ------------------------
4789 -- Enclosing_Instance --
4790 ------------------------
4792 function Enclosing_Instance return Entity_Id is
4796 if not Is_Generic_Instance (Current_Scope)
4797 and then not Is_Actual
4802 S := Scope (Current_Scope);
4803 while S /= Standard_Standard loop
4804 if Is_Generic_Instance (S) then
4812 end Enclosing_Instance;
4814 --------------------------
4815 -- Is_Visible_Operation --
4816 --------------------------
4818 function Is_Visible_Operation (Op : Entity_Id) return Boolean is
4824 if Ekind (Op) /= E_Operator
4825 or else Scope (Op) /= Standard_Standard
4826 or else (In_Instance
4829 or else Present (Enclosing_Instance)))
4834 -- For a fixed point type operator, check the resulting type,
4835 -- because it may be a mixed mode integer * fixed operation.
4837 if Present (Next_Formal (First_Formal (New_S)))
4838 and then Is_Fixed_Point_Type (Etype (New_S))
4840 Typ := Etype (New_S);
4842 Typ := Etype (First_Formal (New_S));
4845 Btyp := Base_Type (Typ);
4847 if Nkind (Nam) /= N_Expanded_Name then
4848 return (In_Open_Scopes (Scope (Btyp))
4849 or else Is_Potentially_Use_Visible (Btyp)
4850 or else In_Use (Btyp)
4851 or else In_Use (Scope (Btyp)));
4854 Scop := Entity (Prefix (Nam));
4856 if Ekind (Scop) = E_Package
4857 and then Present (Renamed_Object (Scop))
4859 Scop := Renamed_Object (Scop);
4862 -- Operator is visible if prefix of expanded name denotes
4863 -- scope of type, or else type is defined in System_Aux
4864 -- and the prefix denotes System.
4866 return Scope (Btyp) = Scop
4867 or else (Scope (Btyp) = System_Aux_Id
4868 and then Scope (Scope (Btyp)) = Scop);
4871 end Is_Visible_Operation;
4877 function Within (Inner, Outer : Entity_Id) return Boolean is
4881 Sc := Scope (Inner);
4882 while Sc /= Standard_Standard loop
4893 ---------------------
4894 -- Report_Overload --
4895 ---------------------
4897 function Report_Overload return Entity_Id is
4901 ("ambiguous actual subprogram&, " &
4902 "possible interpretations:", N, Nam);
4905 ("ambiguous subprogram, " &
4906 "possible interpretations:", N);
4909 List_Interps (Nam, N);
4911 end Report_Overload;
4913 -- Start of processing for Find_Renamed_Entry
4917 Candidate_Renaming := Empty;
4919 if not Is_Overloaded (Nam) then
4920 if Entity_Matches_Spec (Entity (Nam), New_S)
4921 and then Is_Visible_Operation (Entity (Nam))
4923 Old_S := Entity (Nam);
4926 Present (First_Formal (Entity (Nam)))
4927 and then Present (First_Formal (New_S))
4928 and then (Base_Type (Etype (First_Formal (Entity (Nam))))
4929 = Base_Type (Etype (First_Formal (New_S))))
4931 Candidate_Renaming := Entity (Nam);
4935 Get_First_Interp (Nam, Ind, It);
4936 while Present (It.Nam) loop
4937 if Entity_Matches_Spec (It.Nam, New_S)
4938 and then Is_Visible_Operation (It.Nam)
4940 if Old_S /= Any_Id then
4942 -- Note: The call to Disambiguate only happens if a
4943 -- previous interpretation was found, in which case I1
4944 -- has received a value.
4946 It1 := Disambiguate (Nam, I1, Ind, Etype (Old_S));
4948 if It1 = No_Interp then
4949 Inst := Enclosing_Instance;
4951 if Present (Inst) then
4952 if Within (It.Nam, Inst) then
4954 elsif Within (Old_S, Inst) then
4957 return Report_Overload;
4961 return Report_Overload;
4975 Present (First_Formal (It.Nam))
4976 and then Present (First_Formal (New_S))
4977 and then (Base_Type (Etype (First_Formal (It.Nam)))
4978 = Base_Type (Etype (First_Formal (New_S))))
4980 Candidate_Renaming := It.Nam;
4983 Get_Next_Interp (Ind, It);
4986 Set_Entity (Nam, Old_S);
4987 Set_Is_Overloaded (Nam, False);
4991 end Find_Renamed_Entity;
4993 -----------------------------
4994 -- Find_Selected_Component --
4995 -----------------------------
4997 procedure Find_Selected_Component (N : Node_Id) is
4998 P : constant Node_Id := Prefix (N);
5001 -- Entity denoted by prefix
5011 if Nkind (P) = N_Error then
5014 -- If the selector already has an entity, the node has been constructed
5015 -- in the course of expansion, and is known to be valid. Do not verify
5016 -- that it is defined for the type (it may be a private component used
5017 -- in the expansion of record equality).
5019 elsif Present (Entity (Selector_Name (N))) then
5021 or else Etype (N) = Any_Type
5024 Sel_Name : constant Node_Id := Selector_Name (N);
5025 Selector : constant Entity_Id := Entity (Sel_Name);
5029 Set_Etype (Sel_Name, Etype (Selector));
5031 if not Is_Entity_Name (P) then
5035 -- Build an actual subtype except for the first parameter
5036 -- of an init proc, where this actual subtype is by
5037 -- definition incorrect, since the object is uninitialized
5038 -- (and does not even have defined discriminants etc.)
5040 if Is_Entity_Name (P)
5041 and then Ekind (Entity (P)) = E_Function
5043 Nam := New_Copy (P);
5045 if Is_Overloaded (P) then
5046 Save_Interps (P, Nam);
5050 Make_Function_Call (Sloc (P), Name => Nam));
5052 Analyze_Selected_Component (N);
5055 elsif Ekind (Selector) = E_Component
5056 and then (not Is_Entity_Name (P)
5057 or else Chars (Entity (P)) /= Name_uInit)
5060 Build_Actual_Subtype_Of_Component (
5061 Etype (Selector), N);
5066 if No (C_Etype) then
5067 C_Etype := Etype (Selector);
5069 Insert_Action (N, C_Etype);
5070 C_Etype := Defining_Identifier (C_Etype);
5073 Set_Etype (N, C_Etype);
5076 -- If this is the name of an entry or protected operation, and
5077 -- the prefix is an access type, insert an explicit dereference,
5078 -- so that entry calls are treated uniformly.
5080 if Is_Access_Type (Etype (P))
5081 and then Is_Concurrent_Type (Designated_Type (Etype (P)))
5084 New_P : constant Node_Id :=
5085 Make_Explicit_Dereference (Sloc (P),
5086 Prefix => Relocate_Node (P));
5089 Set_Etype (P, Designated_Type (Etype (Prefix (P))));
5093 -- If the selected component appears within a default expression
5094 -- and it has an actual subtype, the pre-analysis has not yet
5095 -- completed its analysis, because Insert_Actions is disabled in
5096 -- that context. Within the init proc of the enclosing type we
5097 -- must complete this analysis, if an actual subtype was created.
5099 elsif Inside_Init_Proc then
5101 Typ : constant Entity_Id := Etype (N);
5102 Decl : constant Node_Id := Declaration_Node (Typ);
5104 if Nkind (Decl) = N_Subtype_Declaration
5105 and then not Analyzed (Decl)
5106 and then Is_List_Member (Decl)
5107 and then No (Parent (Decl))
5110 Insert_Action (N, Decl);
5117 elsif Is_Entity_Name (P) then
5118 P_Name := Entity (P);
5120 -- The prefix may denote an enclosing type which is the completion
5121 -- of an incomplete type declaration.
5123 if Is_Type (P_Name) then
5124 Set_Entity (P, Get_Full_View (P_Name));
5125 Set_Etype (P, Entity (P));
5126 P_Name := Entity (P);
5129 P_Type := Base_Type (Etype (P));
5131 if Debug_Flag_E then
5132 Write_Str ("Found prefix type to be ");
5133 Write_Entity_Info (P_Type, " "); Write_Eol;
5136 -- First check for components of a record object (not the
5137 -- result of a call, which is handled below).
5139 if Is_Appropriate_For_Record (P_Type)
5140 and then not Is_Overloadable (P_Name)
5141 and then not Is_Type (P_Name)
5143 -- Selected component of record. Type checking will validate
5144 -- name of selector.
5145 -- ??? could we rewrite an implicit dereference into an explicit
5148 Analyze_Selected_Component (N);
5150 elsif Is_Appropriate_For_Entry_Prefix (P_Type)
5151 and then not In_Open_Scopes (P_Name)
5152 and then (not Is_Concurrent_Type (Etype (P_Name))
5153 or else not In_Open_Scopes (Etype (P_Name)))
5155 -- Call to protected operation or entry. Type checking is
5156 -- needed on the prefix.
5158 Analyze_Selected_Component (N);
5160 elsif (In_Open_Scopes (P_Name)
5161 and then Ekind (P_Name) /= E_Void
5162 and then not Is_Overloadable (P_Name))
5163 or else (Is_Concurrent_Type (Etype (P_Name))
5164 and then In_Open_Scopes (Etype (P_Name)))
5166 -- Prefix denotes an enclosing loop, block, or task, i.e. an
5167 -- enclosing construct that is not a subprogram or accept.
5169 Find_Expanded_Name (N);
5171 elsif Ekind (P_Name) = E_Package then
5172 Find_Expanded_Name (N);
5174 elsif Is_Overloadable (P_Name) then
5176 -- The subprogram may be a renaming (of an enclosing scope) as
5177 -- in the case of the name of the generic within an instantiation.
5179 if (Ekind (P_Name) = E_Procedure
5180 or else Ekind (P_Name) = E_Function)
5181 and then Present (Alias (P_Name))
5182 and then Is_Generic_Instance (Alias (P_Name))
5184 P_Name := Alias (P_Name);
5187 if Is_Overloaded (P) then
5189 -- The prefix must resolve to a unique enclosing construct
5192 Found : Boolean := False;
5197 Get_First_Interp (P, Ind, It);
5198 while Present (It.Nam) loop
5199 if In_Open_Scopes (It.Nam) then
5202 "prefix must be unique enclosing scope", N);
5203 Set_Entity (N, Any_Id);
5204 Set_Etype (N, Any_Type);
5213 Get_Next_Interp (Ind, It);
5218 if In_Open_Scopes (P_Name) then
5219 Set_Entity (P, P_Name);
5220 Set_Is_Overloaded (P, False);
5221 Find_Expanded_Name (N);
5224 -- If no interpretation as an expanded name is possible, it
5225 -- must be a selected component of a record returned by a
5226 -- function call. Reformat prefix as a function call, the rest
5227 -- is done by type resolution. If the prefix is procedure or
5228 -- entry, as is P.X; this is an error.
5230 if Ekind (P_Name) /= E_Function
5231 and then (not Is_Overloaded (P)
5233 Nkind (Parent (N)) = N_Procedure_Call_Statement)
5235 -- Prefix may mention a package that is hidden by a local
5236 -- declaration: let the user know. Scan the full homonym
5237 -- chain, the candidate package may be anywhere on it.
5239 if Present (Homonym (Current_Entity (P_Name))) then
5241 P_Name := Current_Entity (P_Name);
5243 while Present (P_Name) loop
5244 exit when Ekind (P_Name) = E_Package;
5245 P_Name := Homonym (P_Name);
5248 if Present (P_Name) then
5249 Error_Msg_Sloc := Sloc (Entity (Prefix (N)));
5252 ("package& is hidden by declaration#",
5255 Set_Entity (Prefix (N), P_Name);
5256 Find_Expanded_Name (N);
5259 P_Name := Entity (Prefix (N));
5264 ("invalid prefix in selected component&", N, P_Name);
5265 Change_Selected_Component_To_Expanded_Name (N);
5266 Set_Entity (N, Any_Id);
5267 Set_Etype (N, Any_Type);
5270 Nam := New_Copy (P);
5271 Save_Interps (P, Nam);
5273 Make_Function_Call (Sloc (P), Name => Nam));
5275 Analyze_Selected_Component (N);
5279 -- Remaining cases generate various error messages
5282 -- Format node as expanded name, to avoid cascaded errors
5284 Change_Selected_Component_To_Expanded_Name (N);
5285 Set_Entity (N, Any_Id);
5286 Set_Etype (N, Any_Type);
5288 -- Issue error message, but avoid this if error issued already.
5289 -- Use identifier of prefix if one is available.
5291 if P_Name = Any_Id then
5294 elsif Ekind (P_Name) = E_Void then
5295 Premature_Usage (P);
5297 elsif Nkind (P) /= N_Attribute_Reference then
5299 "invalid prefix in selected component&", P);
5301 if Is_Access_Type (P_Type)
5302 and then Ekind (Designated_Type (P_Type)) = E_Incomplete_Type
5305 ("\dereference must not be of an incomplete type " &
5311 "invalid prefix in selected component", P);
5316 -- If prefix is not the name of an entity, it must be an expression,
5317 -- whose type is appropriate for a record. This is determined by
5320 Analyze_Selected_Component (N);
5322 end Find_Selected_Component;
5328 procedure Find_Type (N : Node_Id) is
5338 elsif Nkind (N) = N_Attribute_Reference then
5340 -- Class attribute. This is not valid in Ada 83 mode, but we do not
5341 -- need to enforce that at this point, since the declaration of the
5342 -- tagged type in the prefix would have been flagged already.
5344 if Attribute_Name (N) = Name_Class then
5345 Check_Restriction (No_Dispatch, N);
5346 Find_Type (Prefix (N));
5348 -- Propagate error from bad prefix
5350 if Etype (Prefix (N)) = Any_Type then
5351 Set_Entity (N, Any_Type);
5352 Set_Etype (N, Any_Type);
5356 T := Base_Type (Entity (Prefix (N)));
5358 -- Case where type is not known to be tagged. Its appearance in
5359 -- the prefix of the 'Class attribute indicates that the full view
5362 if not Is_Tagged_Type (T) then
5363 if Ekind (T) = E_Incomplete_Type then
5365 -- It is legal to denote the class type of an incomplete
5366 -- type. The full type will have to be tagged, of course.
5367 -- In Ada 2005 this usage is declared obsolescent, so we
5368 -- warn accordingly.
5370 -- ??? This test is temporarily disabled (always False)
5371 -- because it causes an unwanted warning on GNAT sources
5372 -- (built with -gnatg, which includes Warn_On_Obsolescent_
5373 -- Feature). Once this issue is cleared in the sources, it
5376 if not Is_Tagged_Type (T)
5377 and then Ada_Version >= Ada_05
5378 and then Warn_On_Obsolescent_Feature
5382 ("applying 'Class to an untagged incomplete type"
5383 & " is an obsolescent feature (RM J.11)", N);
5386 Set_Is_Tagged_Type (T);
5387 Set_Primitive_Operations (T, New_Elmt_List);
5388 Make_Class_Wide_Type (T);
5389 Set_Entity (N, Class_Wide_Type (T));
5390 Set_Etype (N, Class_Wide_Type (T));
5392 elsif Ekind (T) = E_Private_Type
5393 and then not Is_Generic_Type (T)
5394 and then In_Private_Part (Scope (T))
5396 -- The Class attribute can be applied to an untagged private
5397 -- type fulfilled by a tagged type prior to the full type
5398 -- declaration (but only within the parent package's private
5399 -- part). Create the class-wide type now and check that the
5400 -- full type is tagged later during its analysis. Note that
5401 -- we do not mark the private type as tagged, unlike the
5402 -- case of incomplete types, because the type must still
5403 -- appear untagged to outside units.
5405 if No (Class_Wide_Type (T)) then
5406 Make_Class_Wide_Type (T);
5409 Set_Entity (N, Class_Wide_Type (T));
5410 Set_Etype (N, Class_Wide_Type (T));
5413 -- Should we introduce a type Any_Tagged and use Wrong_Type
5414 -- here, it would be a bit more consistent???
5417 ("tagged type required, found}",
5418 Prefix (N), First_Subtype (T));
5419 Set_Entity (N, Any_Type);
5423 -- Case of tagged type
5426 if Is_Concurrent_Type (T) then
5427 if No (Corresponding_Record_Type (Entity (Prefix (N)))) then
5429 -- Previous error. Use current type, which at least
5430 -- provides some operations.
5432 C := Entity (Prefix (N));
5435 C := Class_Wide_Type
5436 (Corresponding_Record_Type (Entity (Prefix (N))));
5440 C := Class_Wide_Type (Entity (Prefix (N)));
5443 Set_Entity_With_Style_Check (N, C);
5444 Generate_Reference (C, N);
5448 -- Base attribute, not allowed in Ada 83
5450 elsif Attribute_Name (N) = Name_Base then
5451 if Ada_Version = Ada_83 and then Comes_From_Source (N) then
5453 ("(Ada 83) Base attribute not allowed in subtype mark", N);
5456 Find_Type (Prefix (N));
5457 Typ := Entity (Prefix (N));
5459 if Ada_Version >= Ada_95
5460 and then not Is_Scalar_Type (Typ)
5461 and then not Is_Generic_Type (Typ)
5464 ("prefix of Base attribute must be scalar type",
5467 elsif Sloc (Typ) = Standard_Location
5468 and then Base_Type (Typ) = Typ
5469 and then Warn_On_Redundant_Constructs
5472 ("?redundant attribute, & is its own base type", N, Typ);
5475 T := Base_Type (Typ);
5477 -- Rewrite attribute reference with type itself (see similar
5478 -- processing in Analyze_Attribute, case Base). Preserve
5479 -- prefix if present, for other legality checks.
5481 if Nkind (Prefix (N)) = N_Expanded_Name then
5483 Make_Expanded_Name (Sloc (N),
5485 Prefix => New_Copy (Prefix (Prefix (N))),
5486 Selector_Name => New_Reference_To (T, Sloc (N))));
5489 Rewrite (N, New_Reference_To (T, Sloc (N)));
5496 elsif Attribute_Name (N) = Name_Stub_Type then
5498 -- This is handled in Analyze_Attribute
5502 -- All other attributes are invalid in a subtype mark
5505 Error_Msg_N ("invalid attribute in subtype mark", N);
5511 if Is_Entity_Name (N) then
5512 T_Name := Entity (N);
5514 Error_Msg_N ("subtype mark required in this context", N);
5515 Set_Etype (N, Any_Type);
5519 if T_Name = Any_Id or else Etype (N) = Any_Type then
5521 -- Undefined id. Make it into a valid type
5523 Set_Entity (N, Any_Type);
5525 elsif not Is_Type (T_Name)
5526 and then T_Name /= Standard_Void_Type
5528 Error_Msg_Sloc := Sloc (T_Name);
5529 Error_Msg_N ("subtype mark required in this context", N);
5530 Error_Msg_NE ("\\found & declared#", N, T_Name);
5531 Set_Entity (N, Any_Type);
5534 -- If the type is an incomplete type created to handle
5535 -- anonymous access components of a record type, then the
5536 -- incomplete type is the visible entity and subsequent
5537 -- references will point to it. Mark the original full
5538 -- type as referenced, to prevent spurious warnings.
5540 if Is_Incomplete_Type (T_Name)
5541 and then Present (Full_View (T_Name))
5542 and then not Comes_From_Source (T_Name)
5544 Set_Referenced (Full_View (T_Name));
5547 T_Name := Get_Full_View (T_Name);
5549 -- Ada 2005 (AI-251, AI-50217): Handle interfaces visible through
5550 -- limited-with clauses
5552 if From_With_Type (T_Name)
5553 and then Ekind (T_Name) in Incomplete_Kind
5554 and then Present (Non_Limited_View (T_Name))
5555 and then Is_Interface (Non_Limited_View (T_Name))
5557 T_Name := Non_Limited_View (T_Name);
5560 if In_Open_Scopes (T_Name) then
5561 if Ekind (Base_Type (T_Name)) = E_Task_Type then
5563 -- In Ada 2005, a task name can be used in an access
5564 -- definition within its own body.
5566 if Ada_Version >= Ada_05
5567 and then Nkind (Parent (N)) = N_Access_Definition
5569 Set_Entity (N, T_Name);
5570 Set_Etype (N, T_Name);
5575 ("task type cannot be used as type mark " &
5576 "within its own spec or body", N);
5579 elsif Ekind (Base_Type (T_Name)) = E_Protected_Type then
5581 -- In Ada 2005, a protected name can be used in an access
5582 -- definition within its own body.
5584 if Ada_Version >= Ada_05
5585 and then Nkind (Parent (N)) = N_Access_Definition
5587 Set_Entity (N, T_Name);
5588 Set_Etype (N, T_Name);
5593 ("protected type cannot be used as type mark " &
5594 "within its own spec or body", N);
5598 Error_Msg_N ("type declaration cannot refer to itself", N);
5601 Set_Etype (N, Any_Type);
5602 Set_Entity (N, Any_Type);
5603 Set_Error_Posted (T_Name);
5607 Set_Entity (N, T_Name);
5608 Set_Etype (N, T_Name);
5612 if Present (Etype (N)) and then Comes_From_Source (N) then
5613 if Is_Fixed_Point_Type (Etype (N)) then
5614 Check_Restriction (No_Fixed_Point, N);
5615 elsif Is_Floating_Point_Type (Etype (N)) then
5616 Check_Restriction (No_Floating_Point, N);
5621 ------------------------------------
5622 -- Has_Implicit_Character_Literal --
5623 ------------------------------------
5625 function Has_Implicit_Character_Literal (N : Node_Id) return Boolean is
5627 Found : Boolean := False;
5628 P : constant Entity_Id := Entity (Prefix (N));
5629 Priv_Id : Entity_Id := Empty;
5632 if Ekind (P) = E_Package
5633 and then not In_Open_Scopes (P)
5635 Priv_Id := First_Private_Entity (P);
5638 if P = Standard_Standard then
5639 Change_Selected_Component_To_Expanded_Name (N);
5640 Rewrite (N, Selector_Name (N));
5642 Set_Etype (Original_Node (N), Standard_Character);
5646 Id := First_Entity (P);
5648 and then Id /= Priv_Id
5650 if Is_Standard_Character_Type (Id)
5651 and then Id = Base_Type (Id)
5653 -- We replace the node with the literal itself, resolve as a
5654 -- character, and set the type correctly.
5657 Change_Selected_Component_To_Expanded_Name (N);
5658 Rewrite (N, Selector_Name (N));
5661 Set_Etype (Original_Node (N), Id);
5665 -- More than one type derived from Character in given scope.
5666 -- Collect all possible interpretations.
5668 Add_One_Interp (N, Id, Id);
5676 end Has_Implicit_Character_Literal;
5678 ----------------------
5679 -- Has_Private_With --
5680 ----------------------
5682 function Has_Private_With (E : Entity_Id) return Boolean is
5683 Comp_Unit : constant Node_Id := Cunit (Current_Sem_Unit);
5687 Item := First (Context_Items (Comp_Unit));
5688 while Present (Item) loop
5689 if Nkind (Item) = N_With_Clause
5690 and then Private_Present (Item)
5691 and then Entity (Name (Item)) = E
5700 end Has_Private_With;
5702 ---------------------------
5703 -- Has_Implicit_Operator --
5704 ---------------------------
5706 function Has_Implicit_Operator (N : Node_Id) return Boolean is
5707 Op_Id : constant Name_Id := Chars (Selector_Name (N));
5708 P : constant Entity_Id := Entity (Prefix (N));
5710 Priv_Id : Entity_Id := Empty;
5712 procedure Add_Implicit_Operator
5714 Op_Type : Entity_Id := Empty);
5715 -- Add implicit interpretation to node N, using the type for which a
5716 -- predefined operator exists. If the operator yields a boolean type,
5717 -- the Operand_Type is implicitly referenced by the operator, and a
5718 -- reference to it must be generated.
5720 ---------------------------
5721 -- Add_Implicit_Operator --
5722 ---------------------------
5724 procedure Add_Implicit_Operator
5726 Op_Type : Entity_Id := Empty)
5728 Predef_Op : Entity_Id;
5731 Predef_Op := Current_Entity (Selector_Name (N));
5733 while Present (Predef_Op)
5734 and then Scope (Predef_Op) /= Standard_Standard
5736 Predef_Op := Homonym (Predef_Op);
5739 if Nkind (N) = N_Selected_Component then
5740 Change_Selected_Component_To_Expanded_Name (N);
5743 Add_One_Interp (N, Predef_Op, T);
5745 -- For operators with unary and binary interpretations, add both
5747 if Present (Homonym (Predef_Op)) then
5748 Add_One_Interp (N, Homonym (Predef_Op), T);
5751 -- The node is a reference to a predefined operator, and
5752 -- an implicit reference to the type of its operands.
5754 if Present (Op_Type) then
5755 Generate_Operator_Reference (N, Op_Type);
5757 Generate_Operator_Reference (N, T);
5759 end Add_Implicit_Operator;
5761 -- Start of processing for Has_Implicit_Operator
5764 if Ekind (P) = E_Package
5765 and then not In_Open_Scopes (P)
5767 Priv_Id := First_Private_Entity (P);
5770 Id := First_Entity (P);
5774 -- Boolean operators: an implicit declaration exists if the scope
5775 -- contains a declaration for a derived Boolean type, or for an
5776 -- array of Boolean type.
5778 when Name_Op_And | Name_Op_Not | Name_Op_Or | Name_Op_Xor =>
5779 while Id /= Priv_Id loop
5780 if Valid_Boolean_Arg (Id)
5781 and then Id = Base_Type (Id)
5783 Add_Implicit_Operator (Id);
5790 -- Equality: look for any non-limited type (result is Boolean)
5792 when Name_Op_Eq | Name_Op_Ne =>
5793 while Id /= Priv_Id loop
5795 and then not Is_Limited_Type (Id)
5796 and then Id = Base_Type (Id)
5798 Add_Implicit_Operator (Standard_Boolean, Id);
5805 -- Comparison operators: scalar type, or array of scalar
5807 when Name_Op_Lt | Name_Op_Le | Name_Op_Gt | Name_Op_Ge =>
5808 while Id /= Priv_Id loop
5809 if (Is_Scalar_Type (Id)
5810 or else (Is_Array_Type (Id)
5811 and then Is_Scalar_Type (Component_Type (Id))))
5812 and then Id = Base_Type (Id)
5814 Add_Implicit_Operator (Standard_Boolean, Id);
5821 -- Arithmetic operators: any numeric type
5831 while Id /= Priv_Id loop
5832 if Is_Numeric_Type (Id)
5833 and then Id = Base_Type (Id)
5835 Add_Implicit_Operator (Id);
5842 -- Concatenation: any one-dimensional array type
5844 when Name_Op_Concat =>
5845 while Id /= Priv_Id loop
5846 if Is_Array_Type (Id) and then Number_Dimensions (Id) = 1
5847 and then Id = Base_Type (Id)
5849 Add_Implicit_Operator (Id);
5856 -- What is the others condition here? Should we be using a
5857 -- subtype of Name_Id that would restrict to operators ???
5859 when others => null;
5862 -- If we fall through, then we do not have an implicit operator
5866 end Has_Implicit_Operator;
5868 --------------------
5869 -- In_Open_Scopes --
5870 --------------------
5872 function In_Open_Scopes (S : Entity_Id) return Boolean is
5874 -- Several scope stacks are maintained by Scope_Stack. The base of the
5875 -- currently active scope stack is denoted by the Is_Active_Stack_Base
5876 -- flag in the scope stack entry. Note that the scope stacks used to
5877 -- simply be delimited implicitly by the presence of Standard_Standard
5878 -- at their base, but there now are cases where this is not sufficient
5879 -- because Standard_Standard actually may appear in the middle of the
5880 -- active set of scopes.
5882 for J in reverse 0 .. Scope_Stack.Last loop
5883 if Scope_Stack.Table (J).Entity = S then
5887 -- Check Is_Active_Stack_Base to tell us when to stop, as there are
5888 -- cases where Standard_Standard appears in the middle of the active
5889 -- set of scopes. This affects the declaration and overriding of
5890 -- private inherited operations in instantiations of generic child
5893 exit when Scope_Stack.Table (J).Is_Active_Stack_Base;
5899 -----------------------------
5900 -- Inherit_Renamed_Profile --
5901 -----------------------------
5903 procedure Inherit_Renamed_Profile (New_S : Entity_Id; Old_S : Entity_Id) is
5910 if Ekind (Old_S) = E_Operator then
5911 New_F := First_Formal (New_S);
5913 while Present (New_F) loop
5914 Set_Etype (New_F, Base_Type (Etype (New_F)));
5915 Next_Formal (New_F);
5918 Set_Etype (New_S, Base_Type (Etype (New_S)));
5921 New_F := First_Formal (New_S);
5922 Old_F := First_Formal (Old_S);
5924 while Present (New_F) loop
5925 New_T := Etype (New_F);
5926 Old_T := Etype (Old_F);
5928 -- If the new type is a renaming of the old one, as is the
5929 -- case for actuals in instances, retain its name, to simplify
5930 -- later disambiguation.
5932 if Nkind (Parent (New_T)) = N_Subtype_Declaration
5933 and then Is_Entity_Name (Subtype_Indication (Parent (New_T)))
5934 and then Entity (Subtype_Indication (Parent (New_T))) = Old_T
5938 Set_Etype (New_F, Old_T);
5941 Next_Formal (New_F);
5942 Next_Formal (Old_F);
5945 if Ekind (Old_S) = E_Function
5946 or else Ekind (Old_S) = E_Enumeration_Literal
5948 Set_Etype (New_S, Etype (Old_S));
5951 end Inherit_Renamed_Profile;
5957 procedure Initialize is
5962 -------------------------
5963 -- Install_Use_Clauses --
5964 -------------------------
5966 procedure Install_Use_Clauses
5968 Force_Installation : Boolean := False)
5976 while Present (U) loop
5978 -- Case of USE package
5980 if Nkind (U) = N_Use_Package_Clause then
5981 P := First (Names (U));
5982 while Present (P) loop
5985 if Ekind (Id) = E_Package then
5987 Note_Redundant_Use (P);
5989 elsif Present (Renamed_Object (Id))
5990 and then In_Use (Renamed_Object (Id))
5992 Note_Redundant_Use (P);
5994 elsif Force_Installation or else Applicable_Use (P) then
5995 Use_One_Package (Id, U);
6006 P := First (Subtype_Marks (U));
6007 while Present (P) loop
6008 if not Is_Entity_Name (P)
6009 or else No (Entity (P))
6013 elsif Entity (P) /= Any_Type then
6021 Next_Use_Clause (U);
6023 end Install_Use_Clauses;
6025 -------------------------------------
6026 -- Is_Appropriate_For_Entry_Prefix --
6027 -------------------------------------
6029 function Is_Appropriate_For_Entry_Prefix (T : Entity_Id) return Boolean is
6030 P_Type : Entity_Id := T;
6033 if Is_Access_Type (P_Type) then
6034 P_Type := Designated_Type (P_Type);
6037 return Is_Task_Type (P_Type) or else Is_Protected_Type (P_Type);
6038 end Is_Appropriate_For_Entry_Prefix;
6040 -------------------------------
6041 -- Is_Appropriate_For_Record --
6042 -------------------------------
6044 function Is_Appropriate_For_Record (T : Entity_Id) return Boolean is
6046 function Has_Components (T1 : Entity_Id) return Boolean;
6047 -- Determine if given type has components (i.e. is either a record
6048 -- type or a type that has discriminants).
6050 --------------------
6051 -- Has_Components --
6052 --------------------
6054 function Has_Components (T1 : Entity_Id) return Boolean is
6056 return Is_Record_Type (T1)
6057 or else (Is_Private_Type (T1) and then Has_Discriminants (T1))
6058 or else (Is_Task_Type (T1) and then Has_Discriminants (T1))
6059 or else (Is_Incomplete_Type (T1)
6060 and then From_With_Type (T1)
6061 and then Present (Non_Limited_View (T1))
6062 and then Is_Record_Type
6063 (Get_Full_View (Non_Limited_View (T1))));
6066 -- Start of processing for Is_Appropriate_For_Record
6071 and then (Has_Components (T)
6072 or else (Is_Access_Type (T)
6073 and then Has_Components (Designated_Type (T))));
6074 end Is_Appropriate_For_Record;
6076 ------------------------
6077 -- Note_Redundant_Use --
6078 ------------------------
6080 procedure Note_Redundant_Use (Clause : Node_Id) is
6081 Pack_Name : constant Entity_Id := Entity (Clause);
6082 Cur_Use : constant Node_Id := Current_Use_Clause (Pack_Name);
6083 Decl : constant Node_Id := Parent (Clause);
6085 Prev_Use : Node_Id := Empty;
6086 Redundant : Node_Id := Empty;
6087 -- The Use_Clause which is actually redundant. In the simplest case
6088 -- it is Pack itself, but when we compile a body we install its
6089 -- context before that of its spec, in which case it is the use_clause
6090 -- in the spec that will appear to be redundant, and we want the
6091 -- warning to be placed on the body. Similar complications appear when
6092 -- the redundancy is between a child unit and one of its ancestors.
6095 Set_Redundant_Use (Clause, True);
6097 if not Comes_From_Source (Clause)
6099 or else not Warn_On_Redundant_Constructs
6104 if not Is_Compilation_Unit (Current_Scope) then
6106 -- If the use_clause is in an inner scope, it is made redundant
6107 -- by some clause in the current context, with one exception:
6108 -- If we're compiling a nested package body, and the use_clause
6109 -- comes from the corresponding spec, the clause is not necessarily
6110 -- fully redundant, so we should not warn. If a warning was
6111 -- warranted, it would have been given when the spec was processed.
6113 if Nkind (Parent (Decl)) = N_Package_Specification then
6115 Package_Spec_Entity : constant Entity_Id :=
6116 Defining_Unit_Name (Parent (Decl));
6118 if In_Package_Body (Package_Spec_Entity) then
6124 Redundant := Clause;
6125 Prev_Use := Cur_Use;
6127 elsif Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Body then
6129 Cur_Unit : constant Unit_Number_Type := Get_Source_Unit (Cur_Use);
6130 New_Unit : constant Unit_Number_Type := Get_Source_Unit (Clause);
6134 if Cur_Unit = New_Unit then
6136 -- Redundant clause in same body
6138 Redundant := Clause;
6139 Prev_Use := Cur_Use;
6141 elsif Cur_Unit = Current_Sem_Unit then
6143 -- If the new clause is not in the current unit it has been
6144 -- analyzed first, and it makes the other one redundant.
6145 -- However, if the new clause appears in a subunit, Cur_Unit
6146 -- is still the parent, and in that case the redundant one
6147 -- is the one appearing in the subunit.
6149 if Nkind (Unit (Cunit (New_Unit))) = N_Subunit then
6150 Redundant := Clause;
6151 Prev_Use := Cur_Use;
6153 -- Most common case: redundant clause in body,
6154 -- original clause in spec. Current scope is spec entity.
6159 Unit (Library_Unit (Cunit (Current_Sem_Unit))))
6161 Redundant := Cur_Use;
6165 -- The new clause may appear in an unrelated unit, when
6166 -- the parents of a generic are being installed prior to
6167 -- instantiation. In this case there must be no warning.
6168 -- We detect this case by checking whether the current top
6169 -- of the stack is related to the current compilation.
6171 Scop := Current_Scope;
6172 while Present (Scop)
6173 and then Scop /= Standard_Standard
6175 if Is_Compilation_Unit (Scop)
6176 and then not Is_Child_Unit (Scop)
6180 elsif Scop = Cunit_Entity (Current_Sem_Unit) then
6184 Scop := Scope (Scop);
6187 Redundant := Cur_Use;
6191 elsif New_Unit = Current_Sem_Unit then
6192 Redundant := Clause;
6193 Prev_Use := Cur_Use;
6196 -- Neither is the current unit, so they appear in parent or
6197 -- sibling units. Warning will be emitted elsewhere.
6203 elsif Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Declaration
6204 and then Present (Parent_Spec (Unit (Cunit (Current_Sem_Unit))))
6206 -- Use_clause is in child unit of current unit, and the child
6207 -- unit appears in the context of the body of the parent, so it
6208 -- has been installed first, even though it is the redundant one.
6209 -- Depending on their placement in the context, the visible or the
6210 -- private parts of the two units, either might appear as redundant,
6211 -- but the message has to be on the current unit.
6213 if Get_Source_Unit (Cur_Use) = Current_Sem_Unit then
6214 Redundant := Cur_Use;
6217 Redundant := Clause;
6218 Prev_Use := Cur_Use;
6221 -- If the new use clause appears in the private part of a parent unit
6222 -- it may appear to be redundant w.r.t. a use clause in a child unit,
6223 -- but the previous use clause was needed in the visible part of the
6224 -- child, and no warning should be emitted.
6226 if Nkind (Parent (Decl)) = N_Package_Specification
6228 List_Containing (Decl) = Private_Declarations (Parent (Decl))
6231 Par : constant Entity_Id := Defining_Entity (Parent (Decl));
6232 Spec : constant Node_Id :=
6233 Specification (Unit (Cunit (Current_Sem_Unit)));
6236 if Is_Compilation_Unit (Par)
6237 and then Par /= Cunit_Entity (Current_Sem_Unit)
6238 and then Parent (Cur_Use) = Spec
6240 List_Containing (Cur_Use) = Visible_Declarations (Spec)
6247 -- Finally, if the current use clause is in the context then
6248 -- the clause is redundant when it is nested within the unit.
6250 elsif Nkind (Parent (Cur_Use)) = N_Compilation_Unit
6251 and then Nkind (Parent (Parent (Clause))) /= N_Compilation_Unit
6252 and then Get_Source_Unit (Cur_Use) = Get_Source_Unit (Clause)
6254 Redundant := Clause;
6255 Prev_Use := Cur_Use;
6261 if Present (Redundant) then
6262 Error_Msg_Sloc := Sloc (Prev_Use);
6264 ("& is already use-visible through previous use clause #?",
6265 Redundant, Pack_Name);
6267 end Note_Redundant_Use;
6273 procedure Pop_Scope is
6274 SST : Scope_Stack_Entry renames Scope_Stack.Table (Scope_Stack.Last);
6277 if Debug_Flag_E then
6281 Scope_Suppress := SST.Save_Scope_Suppress;
6282 Local_Suppress_Stack_Top := SST.Save_Local_Suppress_Stack_Top;
6283 Check_Policy_List := SST.Save_Check_Policy_List;
6285 if Debug_Flag_W then
6286 Write_Str ("--> exiting scope: ");
6287 Write_Name (Chars (Current_Scope));
6288 Write_Str (", Depth=");
6289 Write_Int (Int (Scope_Stack.Last));
6293 End_Use_Clauses (SST.First_Use_Clause);
6295 -- If the actions to be wrapped are still there they will get lost
6296 -- causing incomplete code to be generated. It is better to abort in
6297 -- this case (and we do the abort even with assertions off since the
6298 -- penalty is incorrect code generation)
6300 if SST.Actions_To_Be_Wrapped_Before /= No_List
6302 SST.Actions_To_Be_Wrapped_After /= No_List
6307 -- Free last subprogram name if allocated, and pop scope
6309 Free (SST.Last_Subprogram_Name);
6310 Scope_Stack.Decrement_Last;
6317 procedure Push_Scope (S : Entity_Id) is
6321 if Ekind (S) = E_Void then
6324 -- Set scope depth if not a non-concurrent type, and we have not
6325 -- yet set the scope depth. This means that we have the first
6326 -- occurrence of the scope, and this is where the depth is set.
6328 elsif (not Is_Type (S) or else Is_Concurrent_Type (S))
6329 and then not Scope_Depth_Set (S)
6331 if S = Standard_Standard then
6332 Set_Scope_Depth_Value (S, Uint_0);
6334 elsif Is_Child_Unit (S) then
6335 Set_Scope_Depth_Value (S, Uint_1);
6337 elsif not Is_Record_Type (Current_Scope) then
6338 if Ekind (S) = E_Loop then
6339 Set_Scope_Depth_Value (S, Scope_Depth (Current_Scope));
6341 Set_Scope_Depth_Value (S, Scope_Depth (Current_Scope) + 1);
6346 Scope_Stack.Increment_Last;
6349 SST : Scope_Stack_Entry renames Scope_Stack.Table (Scope_Stack.Last);
6353 SST.Save_Scope_Suppress := Scope_Suppress;
6354 SST.Save_Local_Suppress_Stack_Top := Local_Suppress_Stack_Top;
6355 SST.Save_Check_Policy_List := Check_Policy_List;
6357 if Scope_Stack.Last > Scope_Stack.First then
6358 SST.Component_Alignment_Default := Scope_Stack.Table
6359 (Scope_Stack.Last - 1).
6360 Component_Alignment_Default;
6363 SST.Last_Subprogram_Name := null;
6364 SST.Is_Transient := False;
6365 SST.Node_To_Be_Wrapped := Empty;
6366 SST.Pending_Freeze_Actions := No_List;
6367 SST.Actions_To_Be_Wrapped_Before := No_List;
6368 SST.Actions_To_Be_Wrapped_After := No_List;
6369 SST.First_Use_Clause := Empty;
6370 SST.Is_Active_Stack_Base := False;
6371 SST.Previous_Visibility := False;
6374 if Debug_Flag_W then
6375 Write_Str ("--> new scope: ");
6376 Write_Name (Chars (Current_Scope));
6377 Write_Str (", Id=");
6378 Write_Int (Int (Current_Scope));
6379 Write_Str (", Depth=");
6380 Write_Int (Int (Scope_Stack.Last));
6384 -- Deal with copying flags from the previous scope to this one. This
6385 -- is not necessary if either scope is standard, or if the new scope
6388 if S /= Standard_Standard
6389 and then Scope (S) /= Standard_Standard
6390 and then not Is_Child_Unit (S)
6394 if Nkind (E) not in N_Entity then
6398 -- Copy categorization flags from Scope (S) to S, this is not done
6399 -- when Scope (S) is Standard_Standard since propagation is from
6400 -- library unit entity inwards. Copy other relevant attributes as
6401 -- well (Discard_Names in particular).
6403 -- We only propagate inwards for library level entities,
6404 -- inner level subprograms do not inherit the categorization.
6406 if Is_Library_Level_Entity (S) then
6407 Set_Is_Preelaborated (S, Is_Preelaborated (E));
6408 Set_Is_Shared_Passive (S, Is_Shared_Passive (E));
6409 Set_Discard_Names (S, Discard_Names (E));
6410 Set_Suppress_Value_Tracking_On_Call
6411 (S, Suppress_Value_Tracking_On_Call (E));
6412 Set_Categorization_From_Scope (E => S, Scop => E);
6417 ---------------------
6418 -- Premature_Usage --
6419 ---------------------
6421 procedure Premature_Usage (N : Node_Id) is
6422 Kind : constant Node_Kind := Nkind (Parent (Entity (N)));
6423 E : Entity_Id := Entity (N);
6426 -- Within an instance, the analysis of the actual for a formal object
6427 -- does not see the name of the object itself. This is significant only
6428 -- if the object is an aggregate, where its analysis does not do any
6429 -- name resolution on component associations. (see 4717-008). In such a
6430 -- case, look for the visible homonym on the chain.
6433 and then Present (Homonym (E))
6438 and then not In_Open_Scopes (Scope (E))
6445 Set_Etype (N, Etype (E));
6450 if Kind = N_Component_Declaration then
6452 ("component&! cannot be used before end of record declaration", N);
6454 elsif Kind = N_Parameter_Specification then
6456 ("formal parameter&! cannot be used before end of specification",
6459 elsif Kind = N_Discriminant_Specification then
6461 ("discriminant&! cannot be used before end of discriminant part",
6464 elsif Kind = N_Procedure_Specification
6465 or else Kind = N_Function_Specification
6468 ("subprogram&! cannot be used before end of its declaration",
6471 elsif Kind = N_Full_Type_Declaration then
6473 ("type& cannot be used before end of its declaration!", N);
6477 ("object& cannot be used before end of its declaration!", N);
6479 end Premature_Usage;
6481 ------------------------
6482 -- Present_System_Aux --
6483 ------------------------
6485 function Present_System_Aux (N : Node_Id := Empty) return Boolean is
6487 Aux_Name : Unit_Name_Type;
6488 Unum : Unit_Number_Type;
6493 function Find_System (C_Unit : Node_Id) return Entity_Id;
6494 -- Scan context clause of compilation unit to find with_clause
6501 function Find_System (C_Unit : Node_Id) return Entity_Id is
6502 With_Clause : Node_Id;
6505 With_Clause := First (Context_Items (C_Unit));
6506 while Present (With_Clause) loop
6507 if (Nkind (With_Clause) = N_With_Clause
6508 and then Chars (Name (With_Clause)) = Name_System)
6509 and then Comes_From_Source (With_Clause)
6520 -- Start of processing for Present_System_Aux
6523 -- The child unit may have been loaded and analyzed already
6525 if Present (System_Aux_Id) then
6528 -- If no previous pragma for System.Aux, nothing to load
6530 elsif No (System_Extend_Unit) then
6533 -- Use the unit name given in the pragma to retrieve the unit.
6534 -- Verify that System itself appears in the context clause of the
6535 -- current compilation. If System is not present, an error will
6536 -- have been reported already.
6539 With_Sys := Find_System (Cunit (Current_Sem_Unit));
6541 The_Unit := Unit (Cunit (Current_Sem_Unit));
6545 (Nkind (The_Unit) = N_Package_Body
6546 or else (Nkind (The_Unit) = N_Subprogram_Body
6548 not Acts_As_Spec (Cunit (Current_Sem_Unit))))
6550 With_Sys := Find_System (Library_Unit (Cunit (Current_Sem_Unit)));
6554 and then Present (N)
6556 -- If we are compiling a subunit, we need to examine its
6557 -- context as well (Current_Sem_Unit is the parent unit);
6559 The_Unit := Parent (N);
6560 while Nkind (The_Unit) /= N_Compilation_Unit loop
6561 The_Unit := Parent (The_Unit);
6564 if Nkind (Unit (The_Unit)) = N_Subunit then
6565 With_Sys := Find_System (The_Unit);
6569 if No (With_Sys) then
6573 Loc := Sloc (With_Sys);
6574 Get_Name_String (Chars (Expression (System_Extend_Unit)));
6575 Name_Buffer (8 .. Name_Len + 7) := Name_Buffer (1 .. Name_Len);
6576 Name_Buffer (1 .. 7) := "system.";
6577 Name_Buffer (Name_Len + 8) := '%';
6578 Name_Buffer (Name_Len + 9) := 's';
6579 Name_Len := Name_Len + 9;
6580 Aux_Name := Name_Find;
6584 (Load_Name => Aux_Name,
6587 Error_Node => With_Sys);
6589 if Unum /= No_Unit then
6590 Semantics (Cunit (Unum));
6592 Defining_Entity (Specification (Unit (Cunit (Unum))));
6595 Make_With_Clause (Loc,
6597 Make_Expanded_Name (Loc,
6598 Chars => Chars (System_Aux_Id),
6599 Prefix => New_Reference_To (Scope (System_Aux_Id), Loc),
6600 Selector_Name => New_Reference_To (System_Aux_Id, Loc)));
6602 Set_Entity (Name (Withn), System_Aux_Id);
6604 Set_Library_Unit (Withn, Cunit (Unum));
6605 Set_Corresponding_Spec (Withn, System_Aux_Id);
6606 Set_First_Name (Withn, True);
6607 Set_Implicit_With (Withn, True);
6609 Insert_After (With_Sys, Withn);
6610 Mark_Rewrite_Insertion (Withn);
6611 Set_Context_Installed (Withn);
6615 -- Here if unit load failed
6618 Error_Msg_Name_1 := Name_System;
6619 Error_Msg_Name_2 := Chars (Expression (System_Extend_Unit));
6621 ("extension package `%.%` does not exist",
6622 Opt.System_Extend_Unit);
6626 end Present_System_Aux;
6628 -------------------------
6629 -- Restore_Scope_Stack --
6630 -------------------------
6632 procedure Restore_Scope_Stack (Handle_Use : Boolean := True) is
6635 Comp_Unit : Node_Id;
6636 In_Child : Boolean := False;
6637 Full_Vis : Boolean := True;
6638 SS_Last : constant Int := Scope_Stack.Last;
6641 -- Restore visibility of previous scope stack, if any
6643 for J in reverse 0 .. Scope_Stack.Last loop
6644 exit when Scope_Stack.Table (J).Entity = Standard_Standard
6645 or else No (Scope_Stack.Table (J).Entity);
6647 S := Scope_Stack.Table (J).Entity;
6649 if not Is_Hidden_Open_Scope (S) then
6651 -- If the parent scope is hidden, its entities are hidden as
6652 -- well, unless the entity is the instantiation currently
6655 if not Is_Hidden_Open_Scope (Scope (S))
6656 or else not Analyzed (Parent (S))
6657 or else Scope (S) = Standard_Standard
6659 Set_Is_Immediately_Visible (S, True);
6662 E := First_Entity (S);
6663 while Present (E) loop
6664 if Is_Child_Unit (E) then
6665 Set_Is_Immediately_Visible (E,
6666 Is_Visible_Child_Unit (E) or else In_Open_Scopes (E));
6668 Set_Is_Immediately_Visible (E, True);
6674 and then Is_Package_Or_Generic_Package (S)
6676 -- We are in the visible part of the package scope
6678 exit when E = First_Private_Entity (S);
6682 -- The visibility of child units (siblings of current compilation)
6683 -- must be restored in any case. Their declarations may appear
6684 -- after the private part of the parent.
6686 if not Full_Vis then
6687 while Present (E) loop
6688 if Is_Child_Unit (E) then
6689 Set_Is_Immediately_Visible (E,
6690 Is_Visible_Child_Unit (E) or else In_Open_Scopes (E));
6698 if Is_Child_Unit (S)
6699 and not In_Child -- check only for current unit
6703 -- Restore visibility of parents according to whether the child
6704 -- is private and whether we are in its visible part.
6706 Comp_Unit := Parent (Unit_Declaration_Node (S));
6708 if Nkind (Comp_Unit) = N_Compilation_Unit
6709 and then Private_Present (Comp_Unit)
6713 elsif Is_Package_Or_Generic_Package (S)
6714 and then (In_Private_Part (S)
6715 or else In_Package_Body (S))
6719 -- if S is the scope of some instance (which has already been
6720 -- seen on the stack) it does not affect the visibility of
6723 elsif Is_Hidden_Open_Scope (S) then
6726 elsif (Ekind (S) = E_Procedure
6727 or else Ekind (S) = E_Function)
6728 and then Has_Completion (S)
6739 if SS_Last >= Scope_Stack.First
6740 and then Scope_Stack.Table (SS_Last).Entity /= Standard_Standard
6743 Install_Use_Clauses (Scope_Stack.Table (SS_Last).First_Use_Clause);
6745 end Restore_Scope_Stack;
6747 ----------------------
6748 -- Save_Scope_Stack --
6749 ----------------------
6751 procedure Save_Scope_Stack (Handle_Use : Boolean := True) is
6754 SS_Last : constant Int := Scope_Stack.Last;
6757 if SS_Last >= Scope_Stack.First
6758 and then Scope_Stack.Table (SS_Last).Entity /= Standard_Standard
6761 End_Use_Clauses (Scope_Stack.Table (SS_Last).First_Use_Clause);
6764 -- If the call is from within a compilation unit, as when called from
6765 -- Rtsfind, make current entries in scope stack invisible while we
6766 -- analyze the new unit.
6768 for J in reverse 0 .. SS_Last loop
6769 exit when Scope_Stack.Table (J).Entity = Standard_Standard
6770 or else No (Scope_Stack.Table (J).Entity);
6772 S := Scope_Stack.Table (J).Entity;
6773 Set_Is_Immediately_Visible (S, False);
6775 E := First_Entity (S);
6776 while Present (E) loop
6777 Set_Is_Immediately_Visible (E, False);
6783 end Save_Scope_Stack;
6789 procedure Set_Use (L : List_Id) is
6791 Pack_Name : Node_Id;
6798 while Present (Decl) loop
6799 if Nkind (Decl) = N_Use_Package_Clause then
6800 Chain_Use_Clause (Decl);
6802 Pack_Name := First (Names (Decl));
6803 while Present (Pack_Name) loop
6804 Pack := Entity (Pack_Name);
6806 if Ekind (Pack) = E_Package
6807 and then Applicable_Use (Pack_Name)
6809 Use_One_Package (Pack, Decl);
6815 elsif Nkind (Decl) = N_Use_Type_Clause then
6816 Chain_Use_Clause (Decl);
6818 Id := First (Subtype_Marks (Decl));
6819 while Present (Id) loop
6820 if Entity (Id) /= Any_Type then
6833 ---------------------
6834 -- Use_One_Package --
6835 ---------------------
6837 procedure Use_One_Package (P : Entity_Id; N : Node_Id) is
6840 Current_Instance : Entity_Id := Empty;
6842 Private_With_OK : Boolean := False;
6845 if Ekind (P) /= E_Package then
6850 Set_Current_Use_Clause (P, N);
6852 -- Ada 2005 (AI-50217): Check restriction
6854 if From_With_Type (P) then
6855 Error_Msg_N ("limited withed package cannot appear in use clause", N);
6858 -- Find enclosing instance, if any
6861 Current_Instance := Current_Scope;
6862 while not Is_Generic_Instance (Current_Instance) loop
6863 Current_Instance := Scope (Current_Instance);
6866 if No (Hidden_By_Use_Clause (N)) then
6867 Set_Hidden_By_Use_Clause (N, New_Elmt_List);
6871 -- If unit is a package renaming, indicate that the renamed
6872 -- package is also in use (the flags on both entities must
6873 -- remain consistent, and a subsequent use of either of them
6874 -- should be recognized as redundant).
6876 if Present (Renamed_Object (P)) then
6877 Set_In_Use (Renamed_Object (P));
6878 Set_Current_Use_Clause (Renamed_Object (P), N);
6879 Real_P := Renamed_Object (P);
6884 -- Ada 2005 (AI-262): Check the use_clause of a private withed package
6885 -- found in the private part of a package specification
6887 if In_Private_Part (Current_Scope)
6888 and then Has_Private_With (P)
6889 and then Is_Child_Unit (Current_Scope)
6890 and then Is_Child_Unit (P)
6891 and then Is_Ancestor_Package (Scope (Current_Scope), P)
6893 Private_With_OK := True;
6896 -- Loop through entities in one package making them potentially
6899 Id := First_Entity (P);
6901 and then (Id /= First_Private_Entity (P)
6902 or else Private_With_OK) -- Ada 2005 (AI-262)
6904 Prev := Current_Entity (Id);
6905 while Present (Prev) loop
6906 if Is_Immediately_Visible (Prev)
6907 and then (not Is_Overloadable (Prev)
6908 or else not Is_Overloadable (Id)
6909 or else (Type_Conformant (Id, Prev)))
6911 if No (Current_Instance) then
6913 -- Potentially use-visible entity remains hidden
6915 goto Next_Usable_Entity;
6917 -- A use clause within an instance hides outer global entities,
6918 -- which are not used to resolve local entities in the
6919 -- instance. Note that the predefined entities in Standard
6920 -- could not have been hidden in the generic by a use clause,
6921 -- and therefore remain visible. Other compilation units whose
6922 -- entities appear in Standard must be hidden in an instance.
6924 -- To determine whether an entity is external to the instance
6925 -- we compare the scope depth of its scope with that of the
6926 -- current instance. However, a generic actual of a subprogram
6927 -- instance is declared in the wrapper package but will not be
6928 -- hidden by a use-visible entity.
6930 -- If Id is called Standard, the predefined package with the
6931 -- same name is in the homonym chain. It has to be ignored
6932 -- because it has no defined scope (being the only entity in
6933 -- the system with this mandated behavior).
6935 elsif not Is_Hidden (Id)
6936 and then Present (Scope (Prev))
6937 and then not Is_Wrapper_Package (Scope (Prev))
6938 and then Scope_Depth (Scope (Prev)) <
6939 Scope_Depth (Current_Instance)
6940 and then (Scope (Prev) /= Standard_Standard
6941 or else Sloc (Prev) > Standard_Location)
6943 Set_Is_Potentially_Use_Visible (Id);
6944 Set_Is_Immediately_Visible (Prev, False);
6945 Append_Elmt (Prev, Hidden_By_Use_Clause (N));
6948 -- A user-defined operator is not use-visible if the predefined
6949 -- operator for the type is immediately visible, which is the case
6950 -- if the type of the operand is in an open scope. This does not
6951 -- apply to user-defined operators that have operands of different
6952 -- types, because the predefined mixed mode operations (multiply
6953 -- and divide) apply to universal types and do not hide anything.
6955 elsif Ekind (Prev) = E_Operator
6956 and then Operator_Matches_Spec (Prev, Id)
6957 and then In_Open_Scopes
6958 (Scope (Base_Type (Etype (First_Formal (Id)))))
6959 and then (No (Next_Formal (First_Formal (Id)))
6960 or else Etype (First_Formal (Id))
6961 = Etype (Next_Formal (First_Formal (Id)))
6962 or else Chars (Prev) = Name_Op_Expon)
6964 goto Next_Usable_Entity;
6967 Prev := Homonym (Prev);
6970 -- On exit, we know entity is not hidden, unless it is private
6972 if not Is_Hidden (Id)
6973 and then ((not Is_Child_Unit (Id))
6974 or else Is_Visible_Child_Unit (Id))
6976 Set_Is_Potentially_Use_Visible (Id);
6978 if Is_Private_Type (Id)
6979 and then Present (Full_View (Id))
6981 Set_Is_Potentially_Use_Visible (Full_View (Id));
6985 <<Next_Usable_Entity>>
6989 -- Child units are also made use-visible by a use clause, but they may
6990 -- appear after all visible declarations in the parent entity list.
6992 while Present (Id) loop
6993 if Is_Child_Unit (Id)
6994 and then Is_Visible_Child_Unit (Id)
6996 Set_Is_Potentially_Use_Visible (Id);
7002 if Chars (Real_P) = Name_System
7003 and then Scope (Real_P) = Standard_Standard
7004 and then Present_System_Aux (N)
7006 Use_One_Package (System_Aux_Id, N);
7009 end Use_One_Package;
7015 procedure Use_One_Type (Id : Node_Id) is
7017 Is_Known_Used : Boolean;
7021 function Spec_Reloaded_For_Body return Boolean;
7022 -- Determine whether the compilation unit is a package body and the use
7023 -- type clause is in the spec of the same package. Even though the spec
7024 -- was analyzed first, its context is reloaded when analysing the body.
7026 ----------------------------
7027 -- Spec_Reloaded_For_Body --
7028 ----------------------------
7030 function Spec_Reloaded_For_Body return Boolean is
7032 if Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Body then
7034 Spec : constant Node_Id :=
7035 Parent (List_Containing (Parent (Id)));
7038 Nkind (Spec) = N_Package_Specification
7039 and then Corresponding_Body (Parent (Spec)) =
7040 Cunit_Entity (Current_Sem_Unit);
7045 end Spec_Reloaded_For_Body;
7047 -- Start of processing for Use_One_Type;
7050 -- It is the type determined by the subtype mark (8.4(8)) whose
7051 -- operations become potentially use-visible.
7053 T := Base_Type (Entity (Id));
7055 -- Either the type itself is used, the package where it is declared
7056 -- is in use or the entity is declared in the current package, thus
7061 or else In_Use (Scope (T))
7062 or else Scope (T) = Current_Scope;
7064 Set_Redundant_Use (Id,
7065 Is_Known_Used or else Is_Potentially_Use_Visible (T));
7067 if In_Open_Scopes (Scope (T)) then
7070 -- A limited view cannot appear in a use_type clause. However, an
7071 -- access type whose designated type is limited has the flag but
7072 -- is not itself a limited view unless we only have a limited view
7073 -- of its enclosing package.
7075 elsif From_With_Type (T)
7076 and then From_With_Type (Scope (T))
7079 ("incomplete type from limited view "
7080 & "cannot appear in use clause", Id);
7082 -- If the subtype mark designates a subtype in a different package,
7083 -- we have to check that the parent type is visible, otherwise the
7084 -- use type clause is a noop. Not clear how to do that???
7086 elsif not Redundant_Use (Id) then
7088 Set_Current_Use_Clause (T, Parent (Id));
7089 Op_List := Collect_Primitive_Operations (T);
7091 Elmt := First_Elmt (Op_List);
7092 while Present (Elmt) loop
7093 if (Nkind (Node (Elmt)) = N_Defining_Operator_Symbol
7094 or else Chars (Node (Elmt)) in Any_Operator_Name)
7095 and then not Is_Hidden (Node (Elmt))
7097 Set_Is_Potentially_Use_Visible (Node (Elmt));
7104 -- If warning on redundant constructs, check for unnecessary WITH
7106 if Warn_On_Redundant_Constructs
7107 and then Is_Known_Used
7109 -- with P; with P; use P;
7110 -- package P is package X is package body X is
7111 -- type T ... use P.T;
7113 -- The compilation unit is the body of X. GNAT first compiles the
7114 -- spec of X, then proceeds to the body. At that point P is marked
7115 -- as use visible. The analysis then reinstalls the spec along with
7116 -- its context. The use clause P.T is now recognized as redundant,
7117 -- but in the wrong context. Do not emit a warning in such cases.
7118 -- Do not emit a warning either if we are in an instance, there
7119 -- is no redundancy between an outer use_clause and one that appears
7120 -- within the generic.
7122 and then not Spec_Reloaded_For_Body
7123 and then not In_Instance
7125 -- The type already has a use clause
7129 -- Case where we know the current use clause for the type
7131 if Present (Current_Use_Clause (T)) then
7132 Use_Clause_Known : declare
7133 Clause1 : constant Node_Id := Parent (Id);
7134 Clause2 : constant Node_Id := Current_Use_Clause (T);
7141 function Entity_Of_Unit (U : Node_Id) return Entity_Id;
7142 -- Return the appropriate entity for determining which unit
7143 -- has a deeper scope: the defining entity for U, unless U
7144 -- is a package instance, in which case we retrieve the
7145 -- entity of the instance spec.
7147 --------------------
7148 -- Entity_Of_Unit --
7149 --------------------
7151 function Entity_Of_Unit (U : Node_Id) return Entity_Id is
7153 if Nkind (U) = N_Package_Instantiation
7154 and then Analyzed (U)
7156 return Defining_Entity (Instance_Spec (U));
7158 return Defining_Entity (U);
7162 -- Start of processing for Use_Clause_Known
7165 -- If both current use type clause and the use type
7166 -- clause for the type are at the compilation unit level,
7167 -- one of the units must be an ancestor of the other, and
7168 -- the warning belongs on the descendant.
7170 if Nkind (Parent (Clause1)) = N_Compilation_Unit
7172 Nkind (Parent (Clause2)) = N_Compilation_Unit
7174 Unit1 := Unit (Parent (Clause1));
7175 Unit2 := Unit (Parent (Clause2));
7177 -- There is a redundant use type clause in a child unit.
7178 -- Determine which of the units is more deeply nested.
7179 -- If a unit is a package instance, retrieve the entity
7180 -- and its scope from the instance spec.
7182 Ent1 := Entity_Of_Unit (Unit1);
7183 Ent2 := Entity_Of_Unit (Unit2);
7185 if Scope (Ent2) = Standard_Standard then
7186 Error_Msg_Sloc := Sloc (Current_Use_Clause (T));
7189 elsif Scope (Ent1) = Standard_Standard then
7190 Error_Msg_Sloc := Sloc (Id);
7193 -- If both units are child units, we determine which one
7194 -- is the descendant by the scope distance to the
7195 -- ultimate parent unit.
7204 while S1 /= Standard_Standard
7206 S2 /= Standard_Standard
7212 if S1 = Standard_Standard then
7213 Error_Msg_Sloc := Sloc (Id);
7216 Error_Msg_Sloc := Sloc (Current_Use_Clause (T));
7223 ("& is already use-visible through previous "
7224 & "use_type_clause #?", Err_No, Id);
7226 -- Case where current use type clause and the use type
7227 -- clause for the type are not both at the compilation unit
7228 -- level. In this case we don't have location information.
7232 ("& is already use-visible through previous "
7233 & "use type clause?", Id, Id);
7235 end Use_Clause_Known;
7237 -- Here if Current_Use_Clause is not set for T, another case
7238 -- where we do not have the location information available.
7242 ("& is already use-visible through previous "
7243 & "use type clause?", Id, Id);
7246 -- The package where T is declared is already used
7248 elsif In_Use (Scope (T)) then
7249 Error_Msg_Sloc := Sloc (Current_Use_Clause (Scope (T)));
7251 ("& is already use-visible through package use clause #?",
7254 -- The current scope is the package where T is declared
7257 Error_Msg_Node_2 := Scope (T);
7259 ("& is already use-visible inside package &?", Id, Id);
7268 procedure Write_Info is
7269 Id : Entity_Id := First_Entity (Current_Scope);
7272 -- No point in dumping standard entities
7274 if Current_Scope = Standard_Standard then
7278 Write_Str ("========================================================");
7280 Write_Str (" Defined Entities in ");
7281 Write_Name (Chars (Current_Scope));
7283 Write_Str ("========================================================");
7287 Write_Str ("-- none --");
7291 while Present (Id) loop
7292 Write_Entity_Info (Id, " ");
7297 if Scope (Current_Scope) = Standard_Standard then
7299 -- Print information on the current unit itself
7301 Write_Entity_Info (Current_Scope, " ");
7311 procedure Write_Scopes is
7314 for J in reverse 1 .. Scope_Stack.Last loop
7315 S := Scope_Stack.Table (J).Entity;
7316 Write_Int (Int (S));
7317 Write_Str (" === ");
7318 Write_Name (Chars (S));
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