1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2012, Free Software Foundation, Inc. --
11 -- GNAT is free software; you can redistribute it and/or modify it under --
12 -- terms of the GNU General Public License as published by the Free Soft- --
13 -- ware Foundation; either version 3, or (at your option) any later ver- --
14 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
15 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
16 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
17 -- for more details. You should have received a copy of the GNU General --
18 -- Public License distributed with GNAT; see file COPYING3. If not, go to --
19 -- http://www.gnu.org/licenses for a complete copy of the license. --
21 -- GNAT was originally developed by the GNAT team at New York University. --
22 -- Extensive contributions were provided by Ada Core Technologies Inc. --
24 ------------------------------------------------------------------------------
26 with Atree; use Atree;
27 with Debug; use Debug;
28 with Einfo; use Einfo;
29 with Elists; use Elists;
30 with Errout; use Errout;
31 with Exp_Tss; use Exp_Tss;
32 with Exp_Util; use Exp_Util;
33 with Fname; use Fname;
34 with Freeze; use Freeze;
35 with Impunit; use Impunit;
37 with Lib.Load; use Lib.Load;
38 with Lib.Xref; use Lib.Xref;
39 with Namet; use Namet;
40 with Namet.Sp; use Namet.Sp;
41 with Nlists; use Nlists;
42 with Nmake; use Nmake;
44 with Output; use Output;
45 with Restrict; use Restrict;
46 with Rident; use Rident;
47 with Rtsfind; use Rtsfind;
49 with Sem_Aux; use Sem_Aux;
50 with Sem_Cat; use Sem_Cat;
51 with Sem_Ch3; use Sem_Ch3;
52 with Sem_Ch4; use Sem_Ch4;
53 with Sem_Ch6; use Sem_Ch6;
54 with Sem_Ch12; use Sem_Ch12;
55 with Sem_Ch13; use Sem_Ch13;
56 with Sem_Dim; use Sem_Dim;
57 with Sem_Disp; use Sem_Disp;
58 with Sem_Dist; use Sem_Dist;
59 with Sem_Eval; use Sem_Eval;
60 with Sem_Res; use Sem_Res;
61 with Sem_Util; use Sem_Util;
62 with Sem_Type; use Sem_Type;
63 with Stand; use Stand;
64 with Sinfo; use Sinfo;
65 with Sinfo.CN; use Sinfo.CN;
66 with Snames; use Snames;
67 with Style; use Style;
69 with Targparm; use Targparm;
70 with Tbuild; use Tbuild;
71 with Uintp; use Uintp;
73 package body Sem_Ch8 is
75 ------------------------------------
76 -- Visibility and Name Resolution --
77 ------------------------------------
79 -- This package handles name resolution and the collection of possible
80 -- interpretations for overloaded names, prior to overload resolution.
82 -- Name resolution is the process that establishes a mapping between source
83 -- identifiers and the entities they denote at each point in the program.
84 -- Each entity is represented by a defining occurrence. Each identifier
85 -- that denotes an entity points to the corresponding defining occurrence.
86 -- This is the entity of the applied occurrence. Each occurrence holds
87 -- an index into the names table, where source identifiers are stored.
89 -- Each entry in the names table for an identifier or designator uses the
90 -- Info pointer to hold a link to the currently visible entity that has
91 -- this name (see subprograms Get_Name_Entity_Id and Set_Name_Entity_Id
92 -- in package Sem_Util). The visibility is initialized at the beginning of
93 -- semantic processing to make entities in package Standard immediately
94 -- visible. The visibility table is used in a more subtle way when
95 -- compiling subunits (see below).
97 -- Entities that have the same name (i.e. homonyms) are chained. In the
98 -- case of overloaded entities, this chain holds all the possible meanings
99 -- of a given identifier. The process of overload resolution uses type
100 -- information to select from this chain the unique meaning of a given
103 -- Entities are also chained in their scope, through the Next_Entity link.
104 -- As a consequence, the name space is organized as a sparse matrix, where
105 -- each row corresponds to a scope, and each column to a source identifier.
106 -- Open scopes, that is to say scopes currently being compiled, have their
107 -- corresponding rows of entities in order, innermost scope first.
109 -- The scopes of packages that are mentioned in context clauses appear in
110 -- no particular order, interspersed among open scopes. This is because
111 -- in the course of analyzing the context of a compilation, a package
112 -- declaration is first an open scope, and subsequently an element of the
113 -- context. If subunits or child units are present, a parent unit may
114 -- appear under various guises at various times in the compilation.
116 -- When the compilation of the innermost scope is complete, the entities
117 -- defined therein are no longer visible. If the scope is not a package
118 -- declaration, these entities are never visible subsequently, and can be
119 -- removed from visibility chains. If the scope is a package declaration,
120 -- its visible declarations may still be accessible. Therefore the entities
121 -- defined in such a scope are left on the visibility chains, and only
122 -- their visibility (immediately visibility or potential use-visibility)
125 -- The ordering of homonyms on their chain does not necessarily follow
126 -- the order of their corresponding scopes on the scope stack. For
127 -- example, if package P and the enclosing scope both contain entities
128 -- named E, then when compiling the package body the chain for E will
129 -- hold the global entity first, and the local one (corresponding to
130 -- the current inner scope) next. As a result, name resolution routines
131 -- do not assume any relative ordering of the homonym chains, either
132 -- for scope nesting or to order of appearance of context clauses.
134 -- When compiling a child unit, entities in the parent scope are always
135 -- immediately visible. When compiling the body of a child unit, private
136 -- entities in the parent must also be made immediately visible. There
137 -- are separate routines to make the visible and private declarations
138 -- visible at various times (see package Sem_Ch7).
140 -- +--------+ +-----+
141 -- | In use |-------->| EU1 |-------------------------->
142 -- +--------+ +-----+
144 -- +--------+ +-----+ +-----+
145 -- | Stand. |---------------->| ES1 |--------------->| ES2 |--->
146 -- +--------+ +-----+ +-----+
148 -- +---------+ | +-----+
149 -- | with'ed |------------------------------>| EW2 |--->
150 -- +---------+ | +-----+
152 -- +--------+ +-----+ +-----+
153 -- | Scope2 |---------------->| E12 |--------------->| E22 |--->
154 -- +--------+ +-----+ +-----+
156 -- +--------+ +-----+ +-----+
157 -- | Scope1 |---------------->| E11 |--------------->| E12 |--->
158 -- +--------+ +-----+ +-----+
162 -- | | with'ed |----------------------------------------->
166 -- (innermost first) | |
167 -- +----------------------------+
168 -- Names table => | Id1 | | | | Id2 |
169 -- +----------------------------+
171 -- Name resolution must deal with several syntactic forms: simple names,
172 -- qualified names, indexed names, and various forms of calls.
174 -- Each identifier points to an entry in the names table. The resolution
175 -- of a simple name consists in traversing the homonym chain, starting
176 -- from the names table. If an entry is immediately visible, it is the one
177 -- designated by the identifier. If only potentially use-visible entities
178 -- are on the chain, we must verify that they do not hide each other. If
179 -- the entity we find is overloadable, we collect all other overloadable
180 -- entities on the chain as long as they are not hidden.
182 -- To resolve expanded names, we must find the entity at the intersection
183 -- of the entity chain for the scope (the prefix) and the homonym chain
184 -- for the selector. In general, homonym chains will be much shorter than
185 -- entity chains, so it is preferable to start from the names table as
186 -- well. If the entity found is overloadable, we must collect all other
187 -- interpretations that are defined in the scope denoted by the prefix.
189 -- For records, protected types, and tasks, their local entities are
190 -- removed from visibility chains on exit from the corresponding scope.
191 -- From the outside, these entities are always accessed by selected
192 -- notation, and the entity chain for the record type, protected type,
193 -- etc. is traversed sequentially in order to find the designated entity.
195 -- The discriminants of a type and the operations of a protected type or
196 -- task are unchained on exit from the first view of the type, (such as
197 -- a private or incomplete type declaration, or a protected type speci-
198 -- fication) and re-chained when compiling the second view.
200 -- In the case of operators, we do not make operators on derived types
201 -- explicit. As a result, the notation P."+" may denote either a user-
202 -- defined function with name "+", or else an implicit declaration of the
203 -- operator "+" in package P. The resolution of expanded names always
204 -- tries to resolve an operator name as such an implicitly defined entity,
205 -- in addition to looking for explicit declarations.
207 -- All forms of names that denote entities (simple names, expanded names,
208 -- character literals in some cases) have a Entity attribute, which
209 -- identifies the entity denoted by the name.
211 ---------------------
212 -- The Scope Stack --
213 ---------------------
215 -- The Scope stack keeps track of the scopes currently been compiled.
216 -- Every entity that contains declarations (including records) is placed
217 -- on the scope stack while it is being processed, and removed at the end.
218 -- Whenever a non-package scope is exited, the entities defined therein
219 -- are removed from the visibility table, so that entities in outer scopes
220 -- become visible (see previous description). On entry to Sem, the scope
221 -- stack only contains the package Standard. As usual, subunits complicate
222 -- this picture ever so slightly.
224 -- The Rtsfind mechanism can force a call to Semantics while another
225 -- compilation is in progress. The unit retrieved by Rtsfind must be
226 -- compiled in its own context, and has no access to the visibility of
227 -- the unit currently being compiled. The procedures Save_Scope_Stack and
228 -- Restore_Scope_Stack make entities in current open scopes invisible
229 -- before compiling the retrieved unit, and restore the compilation
230 -- environment afterwards.
232 ------------------------
233 -- Compiling subunits --
234 ------------------------
236 -- Subunits must be compiled in the environment of the corresponding stub,
237 -- that is to say with the same visibility into the parent (and its
238 -- context) that is available at the point of the stub declaration, but
239 -- with the additional visibility provided by the context clause of the
240 -- subunit itself. As a result, compilation of a subunit forces compilation
241 -- of the parent (see description in lib-). At the point of the stub
242 -- declaration, Analyze is called recursively to compile the proper body of
243 -- the subunit, but without reinitializing the names table, nor the scope
244 -- stack (i.e. standard is not pushed on the stack). In this fashion the
245 -- context of the subunit is added to the context of the parent, and the
246 -- subunit is compiled in the correct environment. Note that in the course
247 -- of processing the context of a subunit, Standard will appear twice on
248 -- the scope stack: once for the parent of the subunit, and once for the
249 -- unit in the context clause being compiled. However, the two sets of
250 -- entities are not linked by homonym chains, so that the compilation of
251 -- any context unit happens in a fresh visibility environment.
253 -------------------------------
254 -- Processing of USE Clauses --
255 -------------------------------
257 -- Every defining occurrence has a flag indicating if it is potentially use
258 -- visible. Resolution of simple names examines this flag. The processing
259 -- of use clauses consists in setting this flag on all visible entities
260 -- defined in the corresponding package. On exit from the scope of the use
261 -- clause, the corresponding flag must be reset. However, a package may
262 -- appear in several nested use clauses (pathological but legal, alas!)
263 -- which forces us to use a slightly more involved scheme:
265 -- a) The defining occurrence for a package holds a flag -In_Use- to
266 -- indicate that it is currently in the scope of a use clause. If a
267 -- redundant use clause is encountered, then the corresponding occurrence
268 -- of the package name is flagged -Redundant_Use-.
270 -- b) On exit from a scope, the use clauses in its declarative part are
271 -- scanned. The visibility flag is reset in all entities declared in
272 -- package named in a use clause, as long as the package is not flagged
273 -- as being in a redundant use clause (in which case the outer use
274 -- clause is still in effect, and the direct visibility of its entities
275 -- must be retained).
277 -- Note that entities are not removed from their homonym chains on exit
278 -- from the package specification. A subsequent use clause does not need
279 -- to rechain the visible entities, but only to establish their direct
282 -----------------------------------
283 -- Handling private declarations --
284 -----------------------------------
286 -- The principle that each entity has a single defining occurrence clashes
287 -- with the presence of two separate definitions for private types: the
288 -- first is the private type declaration, and second is the full type
289 -- declaration. It is important that all references to the type point to
290 -- the same defining occurrence, namely the first one. To enforce the two
291 -- separate views of the entity, the corresponding information is swapped
292 -- between the two declarations. Outside of the package, the defining
293 -- occurrence only contains the private declaration information, while in
294 -- the private part and the body of the package the defining occurrence
295 -- contains the full declaration. To simplify the swap, the defining
296 -- occurrence that currently holds the private declaration points to the
297 -- full declaration. During semantic processing the defining occurrence
298 -- also points to a list of private dependents, that is to say access types
299 -- or composite types whose designated types or component types are
300 -- subtypes or derived types of the private type in question. After the
301 -- full declaration has been seen, the private dependents are updated to
302 -- indicate that they have full definitions.
304 ------------------------------------
305 -- Handling of Undefined Messages --
306 ------------------------------------
308 -- In normal mode, only the first use of an undefined identifier generates
309 -- a message. The table Urefs is used to record error messages that have
310 -- been issued so that second and subsequent ones do not generate further
311 -- messages. However, the second reference causes text to be added to the
312 -- original undefined message noting "(more references follow)". The
313 -- full error list option (-gnatf) forces messages to be generated for
314 -- every reference and disconnects the use of this table.
316 type Uref_Entry is record
318 -- Node for identifier for which original message was posted. The
319 -- Chars field of this identifier is used to detect later references
320 -- to the same identifier.
323 -- Records error message Id of original undefined message. Reset to
324 -- No_Error_Msg after the second occurrence, where it is used to add
325 -- text to the original message as described above.
328 -- Set if the message is not visible rather than undefined
331 -- Records location of error message. Used to make sure that we do
332 -- not consider a, b : undefined as two separate instances, which
333 -- would otherwise happen, since the parser converts this sequence
334 -- to a : undefined; b : undefined.
338 package Urefs is new Table.Table (
339 Table_Component_Type => Uref_Entry,
340 Table_Index_Type => Nat,
341 Table_Low_Bound => 1,
343 Table_Increment => 100,
344 Table_Name => "Urefs");
346 Candidate_Renaming : Entity_Id;
347 -- Holds a candidate interpretation that appears in a subprogram renaming
348 -- declaration and does not match the given specification, but matches at
349 -- least on the first formal. Allows better error message when given
350 -- specification omits defaulted parameters, a common error.
352 -----------------------
353 -- Local Subprograms --
354 -----------------------
356 procedure Analyze_Generic_Renaming
359 -- Common processing for all three kinds of generic renaming declarations.
360 -- Enter new name and indicate that it renames the generic unit.
362 procedure Analyze_Renamed_Character
366 -- Renamed entity is given by a character literal, which must belong
367 -- to the return type of the new entity. Is_Body indicates whether the
368 -- declaration is a renaming_as_body. If the original declaration has
369 -- already been frozen (because of an intervening body, e.g.) the body of
370 -- the function must be built now. The same applies to the following
371 -- various renaming procedures.
373 procedure Analyze_Renamed_Dereference
377 -- Renamed entity is given by an explicit dereference. Prefix must be a
378 -- conformant access_to_subprogram type.
380 procedure Analyze_Renamed_Entry
384 -- If the renamed entity in a subprogram renaming is an entry or protected
385 -- subprogram, build a body for the new entity whose only statement is a
386 -- call to the renamed entity.
388 procedure Analyze_Renamed_Family_Member
392 -- Used when the renamed entity is an indexed component. The prefix must
393 -- denote an entry family.
395 procedure Analyze_Renamed_Primitive_Operation
399 -- If the renamed entity in a subprogram renaming is a primitive operation
400 -- or a class-wide operation in prefix form, save the target object, which
401 -- must be added to the list of actuals in any subsequent call.
403 function Applicable_Use (Pack_Name : Node_Id) return Boolean;
404 -- Common code to Use_One_Package and Set_Use, to determine whether use
405 -- clause must be processed. Pack_Name is an entity name that references
406 -- the package in question.
408 procedure Attribute_Renaming (N : Node_Id);
409 -- Analyze renaming of attribute as subprogram. The renaming declaration N
410 -- is rewritten as a subprogram body that returns the attribute reference
411 -- applied to the formals of the function.
413 procedure Set_Entity_Or_Discriminal (N : Node_Id; E : Entity_Id);
414 -- Set Entity, with style check if need be. For a discriminant reference,
415 -- replace by the corresponding discriminal, i.e. the parameter of the
416 -- initialization procedure that corresponds to the discriminant.
418 procedure Check_Frozen_Renaming (N : Node_Id; Subp : Entity_Id);
419 -- A renaming_as_body may occur after the entity of the original decla-
420 -- ration has been frozen. In that case, the body of the new entity must
421 -- be built now, because the usual mechanism of building the renamed
422 -- body at the point of freezing will not work. Subp is the subprogram
423 -- for which N provides the Renaming_As_Body.
425 procedure Check_In_Previous_With_Clause
428 -- N is a use_package clause and Nam the package name, or N is a use_type
429 -- clause and Nam is the prefix of the type name. In either case, verify
430 -- that the package is visible at that point in the context: either it
431 -- appears in a previous with_clause, or because it is a fully qualified
432 -- name and the root ancestor appears in a previous with_clause.
434 procedure Check_Library_Unit_Renaming (N : Node_Id; Old_E : Entity_Id);
435 -- Verify that the entity in a renaming declaration that is a library unit
436 -- is itself a library unit and not a nested unit or subunit. Also check
437 -- that if the renaming is a child unit of a generic parent, then the
438 -- renamed unit must also be a child unit of that parent. Finally, verify
439 -- that a renamed generic unit is not an implicit child declared within
440 -- an instance of the parent.
442 procedure Chain_Use_Clause (N : Node_Id);
443 -- Chain use clause onto list of uses clauses headed by First_Use_Clause in
444 -- the proper scope table entry. This is usually the current scope, but it
445 -- will be an inner scope when installing the use clauses of the private
446 -- declarations of a parent unit prior to compiling the private part of a
447 -- child unit. This chain is traversed when installing/removing use clauses
448 -- when compiling a subunit or instantiating a generic body on the fly,
449 -- when it is necessary to save and restore full environments.
451 function Has_Implicit_Character_Literal (N : Node_Id) return Boolean;
452 -- Find a type derived from Character or Wide_Character in the prefix of N.
453 -- Used to resolved qualified names whose selector is a character literal.
455 function Has_Private_With (E : Entity_Id) return Boolean;
456 -- Ada 2005 (AI-262): Determines if the current compilation unit has a
457 -- private with on E.
459 procedure Find_Expanded_Name (N : Node_Id);
460 -- The input is a selected component known to be an expanded name. Verify
461 -- legality of selector given the scope denoted by prefix, and change node
462 -- N into a expanded name with a properly set Entity field.
464 function Find_Renamed_Entity
468 Is_Actual : Boolean := False) return Entity_Id;
469 -- Find the renamed entity that corresponds to the given parameter profile
470 -- in a subprogram renaming declaration. The renamed entity may be an
471 -- operator, a subprogram, an entry, or a protected operation. Is_Actual
472 -- indicates that the renaming is the one generated for an actual subpro-
473 -- gram in an instance, for which special visibility checks apply.
475 function Has_Implicit_Operator (N : Node_Id) return Boolean;
476 -- N is an expanded name whose selector is an operator name (e.g. P."+").
477 -- declarative part contains an implicit declaration of an operator if it
478 -- has a declaration of a type to which one of the predefined operators
479 -- apply. The existence of this routine is an implementation artifact. A
480 -- more straightforward but more space-consuming choice would be to make
481 -- all inherited operators explicit in the symbol table.
483 procedure Inherit_Renamed_Profile (New_S : Entity_Id; Old_S : Entity_Id);
484 -- A subprogram defined by a renaming declaration inherits the parameter
485 -- profile of the renamed entity. The subtypes given in the subprogram
486 -- specification are discarded and replaced with those of the renamed
487 -- subprogram, which are then used to recheck the default values.
489 function Is_Appropriate_For_Record (T : Entity_Id) return Boolean;
490 -- Prefix is appropriate for record if it is of a record type, or an access
493 function Is_Appropriate_For_Entry_Prefix (T : Entity_Id) return Boolean;
494 -- True if it is of a task type, a protected type, or else an access to one
497 procedure Note_Redundant_Use (Clause : Node_Id);
498 -- Mark the name in a use clause as redundant if the corresponding entity
499 -- is already use-visible. Emit a warning if the use clause comes from
500 -- source and the proper warnings are enabled.
502 procedure Premature_Usage (N : Node_Id);
503 -- Diagnose usage of an entity before it is visible
505 procedure Use_One_Package (P : Entity_Id; N : Node_Id);
506 -- Make visible entities declared in package P potentially use-visible
507 -- in the current context. Also used in the analysis of subunits, when
508 -- re-installing use clauses of parent units. N is the use_clause that
509 -- names P (and possibly other packages).
511 procedure Use_One_Type (Id : Node_Id; Installed : Boolean := False);
512 -- Id is the subtype mark from a use type clause. This procedure makes
513 -- the primitive operators of the type potentially use-visible. The
514 -- boolean flag Installed indicates that the clause is being reinstalled
515 -- after previous analysis, and primitive operations are already chained
516 -- on the Used_Operations list of the clause.
518 procedure Write_Info;
519 -- Write debugging information on entities declared in current scope
521 --------------------------------
522 -- Analyze_Exception_Renaming --
523 --------------------------------
525 -- The language only allows a single identifier, but the tree holds an
526 -- identifier list. The parser has already issued an error message if
527 -- there is more than one element in the list.
529 procedure Analyze_Exception_Renaming (N : Node_Id) is
530 Id : constant Node_Id := Defining_Identifier (N);
531 Nam : constant Node_Id := Name (N);
534 Check_SPARK_Restriction ("exception renaming is not allowed", N);
539 Set_Ekind (Id, E_Exception);
540 Set_Exception_Code (Id, Uint_0);
541 Set_Etype (Id, Standard_Exception_Type);
542 Set_Is_Pure (Id, Is_Pure (Current_Scope));
544 if not Is_Entity_Name (Nam) or else
545 Ekind (Entity (Nam)) /= E_Exception
547 Error_Msg_N ("invalid exception name in renaming", Nam);
549 if Present (Renamed_Object (Entity (Nam))) then
550 Set_Renamed_Object (Id, Renamed_Object (Entity (Nam)));
552 Set_Renamed_Object (Id, Entity (Nam));
555 end Analyze_Exception_Renaming;
557 ---------------------------
558 -- Analyze_Expanded_Name --
559 ---------------------------
561 procedure Analyze_Expanded_Name (N : Node_Id) is
563 -- If the entity pointer is already set, this is an internal node, or a
564 -- node that is analyzed more than once, after a tree modification. In
565 -- such a case there is no resolution to perform, just set the type. For
566 -- completeness, analyze prefix as well.
568 if Present (Entity (N)) then
569 if Is_Type (Entity (N)) then
570 Set_Etype (N, Entity (N));
572 Set_Etype (N, Etype (Entity (N)));
575 Analyze (Prefix (N));
578 Find_Expanded_Name (N);
580 end Analyze_Expanded_Name;
582 ---------------------------------------
583 -- Analyze_Generic_Function_Renaming --
584 ---------------------------------------
586 procedure Analyze_Generic_Function_Renaming (N : Node_Id) is
588 Analyze_Generic_Renaming (N, E_Generic_Function);
589 end Analyze_Generic_Function_Renaming;
591 --------------------------------------
592 -- Analyze_Generic_Package_Renaming --
593 --------------------------------------
595 procedure Analyze_Generic_Package_Renaming (N : Node_Id) is
597 -- Apply the Text_IO Kludge here, since we may be renaming one of the
598 -- subpackages of Text_IO, then join common routine.
600 Text_IO_Kludge (Name (N));
602 Analyze_Generic_Renaming (N, E_Generic_Package);
603 end Analyze_Generic_Package_Renaming;
605 ----------------------------------------
606 -- Analyze_Generic_Procedure_Renaming --
607 ----------------------------------------
609 procedure Analyze_Generic_Procedure_Renaming (N : Node_Id) is
611 Analyze_Generic_Renaming (N, E_Generic_Procedure);
612 end Analyze_Generic_Procedure_Renaming;
614 ------------------------------
615 -- Analyze_Generic_Renaming --
616 ------------------------------
618 procedure Analyze_Generic_Renaming
622 New_P : constant Entity_Id := Defining_Entity (N);
624 Inst : Boolean := False; -- prevent junk warning
627 if Name (N) = Error then
631 Check_SPARK_Restriction ("generic renaming is not allowed", N);
633 Generate_Definition (New_P);
635 if Current_Scope /= Standard_Standard then
636 Set_Is_Pure (New_P, Is_Pure (Current_Scope));
639 if Nkind (Name (N)) = N_Selected_Component then
640 Check_Generic_Child_Unit (Name (N), Inst);
645 if not Is_Entity_Name (Name (N)) then
646 Error_Msg_N ("expect entity name in renaming declaration", Name (N));
649 Old_P := Entity (Name (N));
653 Set_Ekind (New_P, K);
655 if Etype (Old_P) = Any_Type then
658 elsif Ekind (Old_P) /= K then
659 Error_Msg_N ("invalid generic unit name", Name (N));
662 if Present (Renamed_Object (Old_P)) then
663 Set_Renamed_Object (New_P, Renamed_Object (Old_P));
665 Set_Renamed_Object (New_P, Old_P);
668 Set_Is_Pure (New_P, Is_Pure (Old_P));
669 Set_Is_Preelaborated (New_P, Is_Preelaborated (Old_P));
671 Set_Etype (New_P, Etype (Old_P));
672 Set_Has_Completion (New_P);
674 if In_Open_Scopes (Old_P) then
675 Error_Msg_N ("within its scope, generic denotes its instance", N);
678 Check_Library_Unit_Renaming (N, Old_P);
680 end Analyze_Generic_Renaming;
682 -----------------------------
683 -- Analyze_Object_Renaming --
684 -----------------------------
686 procedure Analyze_Object_Renaming (N : Node_Id) is
687 Loc : constant Source_Ptr := Sloc (N);
688 Id : constant Entity_Id := Defining_Identifier (N);
690 Nam : constant Node_Id := Name (N);
694 procedure Check_Constrained_Object;
695 -- If the nominal type is unconstrained but the renamed object is
696 -- constrained, as can happen with renaming an explicit dereference or
697 -- a function return, build a constrained subtype from the object. If
698 -- the renaming is for a formal in an accept statement, the analysis
699 -- has already established its actual subtype. This is only relevant
700 -- if the renamed object is an explicit dereference.
702 function In_Generic_Scope (E : Entity_Id) return Boolean;
703 -- Determine whether entity E is inside a generic cope
705 ------------------------------
706 -- Check_Constrained_Object --
707 ------------------------------
709 procedure Check_Constrained_Object is
713 if Nkind_In (Nam, N_Function_Call, N_Explicit_Dereference)
714 and then Is_Composite_Type (Etype (Nam))
715 and then not Is_Constrained (Etype (Nam))
716 and then not Has_Unknown_Discriminants (Etype (Nam))
717 and then Expander_Active
719 -- If Actual_Subtype is already set, nothing to do
721 if Ekind_In (Id, E_Variable, E_Constant)
722 and then Present (Actual_Subtype (Id))
726 -- A renaming of an unchecked union does not have an
729 elsif Is_Unchecked_Union (Etype (Nam)) then
733 Subt := Make_Temporary (Loc, 'T');
734 Remove_Side_Effects (Nam);
736 Make_Subtype_Declaration (Loc,
737 Defining_Identifier => Subt,
738 Subtype_Indication =>
739 Make_Subtype_From_Expr (Nam, Etype (Nam))));
740 Rewrite (Subtype_Mark (N), New_Occurrence_Of (Subt, Loc));
741 Set_Etype (Nam, Subt);
744 end Check_Constrained_Object;
746 ----------------------
747 -- In_Generic_Scope --
748 ----------------------
750 function In_Generic_Scope (E : Entity_Id) return Boolean is
755 while Present (S) and then S /= Standard_Standard loop
756 if Is_Generic_Unit (S) then
764 end In_Generic_Scope;
766 -- Start of processing for Analyze_Object_Renaming
773 Check_SPARK_Restriction ("object renaming is not allowed", N);
775 Set_Is_Pure (Id, Is_Pure (Current_Scope));
778 -- The renaming of a component that depends on a discriminant requires
779 -- an actual subtype, because in subsequent use of the object Gigi will
780 -- be unable to locate the actual bounds. This explicit step is required
781 -- when the renaming is generated in removing side effects of an
782 -- already-analyzed expression.
784 if Nkind (Nam) = N_Selected_Component
785 and then Analyzed (Nam)
788 Dec := Build_Actual_Subtype_Of_Component (Etype (Nam), Nam);
790 if Present (Dec) then
791 Insert_Action (N, Dec);
792 T := Defining_Identifier (Dec);
796 -- Complete analysis of the subtype mark in any case, for ASIS use
798 if Present (Subtype_Mark (N)) then
799 Find_Type (Subtype_Mark (N));
802 elsif Present (Subtype_Mark (N)) then
803 Find_Type (Subtype_Mark (N));
804 T := Entity (Subtype_Mark (N));
807 -- Reject renamings of conversions unless the type is tagged, or
808 -- the conversion is implicit (which can occur for cases of anonymous
809 -- access types in Ada 2012).
811 if Nkind (Nam) = N_Type_Conversion
812 and then Comes_From_Source (Nam)
813 and then not Is_Tagged_Type (T)
816 ("renaming of conversion only allowed for tagged types", Nam);
821 -- If the renamed object is a function call of a limited type,
822 -- the expansion of the renaming is complicated by the presence
823 -- of various temporaries and subtypes that capture constraints
824 -- of the renamed object. Rewrite node as an object declaration,
825 -- whose expansion is simpler. Given that the object is limited
826 -- there is no copy involved and no performance hit.
828 if Nkind (Nam) = N_Function_Call
829 and then Is_Immutably_Limited_Type (Etype (Nam))
830 and then not Is_Constrained (Etype (Nam))
831 and then Comes_From_Source (N)
834 Set_Ekind (Id, E_Constant);
836 Make_Object_Declaration (Loc,
837 Defining_Identifier => Id,
838 Constant_Present => True,
839 Object_Definition => New_Occurrence_Of (Etype (Nam), Loc),
840 Expression => Relocate_Node (Nam)));
844 -- Ada 2012 (AI05-149): Reject renaming of an anonymous access object
845 -- when renaming declaration has a named access type. The Ada 2012
846 -- coverage rules allow an anonymous access type in the context of
847 -- an expected named general access type, but the renaming rules
848 -- require the types to be the same. (An exception is when the type
849 -- of the renaming is also an anonymous access type, which can only
850 -- happen due to a renaming created by the expander.)
852 if Nkind (Nam) = N_Type_Conversion
853 and then not Comes_From_Source (Nam)
854 and then Ekind (Etype (Expression (Nam))) = E_Anonymous_Access_Type
855 and then Ekind (T) /= E_Anonymous_Access_Type
857 Wrong_Type (Expression (Nam), T); -- Should we give better error???
860 -- Check that a class-wide object is not being renamed as an object
861 -- of a specific type. The test for access types is needed to exclude
862 -- cases where the renamed object is a dynamically tagged access
863 -- result, such as occurs in certain expansions.
865 if Is_Tagged_Type (T) then
866 Check_Dynamically_Tagged_Expression
872 -- Ada 2005 (AI-230/AI-254): Access renaming
874 else pragma Assert (Present (Access_Definition (N)));
875 T := Access_Definition
877 N => Access_Definition (N));
881 -- Ada 2005 AI05-105: if the declaration has an anonymous access
882 -- type, the renamed object must also have an anonymous type, and
883 -- this is a name resolution rule. This was implicit in the last part
884 -- of the first sentence in 8.5.1(3/2), and is made explicit by this
887 if not Is_Overloaded (Nam) then
888 if Ekind (Etype (Nam)) /= Ekind (T) then
890 ("expect anonymous access type in object renaming", N);
897 Typ : Entity_Id := Empty;
898 Seen : Boolean := False;
901 Get_First_Interp (Nam, I, It);
902 while Present (It.Typ) loop
904 -- Renaming is ambiguous if more than one candidate
905 -- interpretation is type-conformant with the context.
907 if Ekind (It.Typ) = Ekind (T) then
908 if Ekind (T) = E_Anonymous_Access_Subprogram_Type
911 (Designated_Type (T), Designated_Type (It.Typ))
917 ("ambiguous expression in renaming", Nam);
920 elsif Ekind (T) = E_Anonymous_Access_Type
922 Covers (Designated_Type (T), Designated_Type (It.Typ))
928 ("ambiguous expression in renaming", Nam);
932 if Covers (T, It.Typ) then
934 Set_Etype (Nam, Typ);
935 Set_Is_Overloaded (Nam, False);
939 Get_Next_Interp (I, It);
946 -- Ada 2005 (AI-231): "In the case where the type is defined by an
947 -- access_definition, the renamed entity shall be of an access-to-
948 -- constant type if and only if the access_definition defines an
949 -- access-to-constant type" ARM 8.5.1(4)
951 if Constant_Present (Access_Definition (N))
952 and then not Is_Access_Constant (Etype (Nam))
954 Error_Msg_N ("(Ada 2005): the renamed object is not "
955 & "access-to-constant (RM 8.5.1(6))", N);
957 elsif not Constant_Present (Access_Definition (N))
958 and then Is_Access_Constant (Etype (Nam))
960 Error_Msg_N ("(Ada 2005): the renamed object is not "
961 & "access-to-variable (RM 8.5.1(6))", N);
964 if Is_Access_Subprogram_Type (Etype (Nam)) then
965 Check_Subtype_Conformant
966 (Designated_Type (T), Designated_Type (Etype (Nam)));
968 elsif not Subtypes_Statically_Match
969 (Designated_Type (T),
970 Available_View (Designated_Type (Etype (Nam))))
973 ("subtype of renamed object does not statically match", N);
977 -- Special processing for renaming function return object. Some errors
978 -- and warnings are produced only for calls that come from source.
980 if Nkind (Nam) = N_Function_Call then
983 -- Usage is illegal in Ada 83
986 if Comes_From_Source (Nam) then
988 ("(Ada 83) cannot rename function return object", Nam);
991 -- In Ada 95, warn for odd case of renaming parameterless function
992 -- call if this is not a limited type (where this is useful).
995 if Warn_On_Object_Renames_Function
996 and then No (Parameter_Associations (Nam))
997 and then not Is_Limited_Type (Etype (Nam))
998 and then Comes_From_Source (Nam)
1001 ("?renaming function result object is suspicious", Nam);
1003 ("\?function & will be called only once", Nam,
1004 Entity (Name (Nam)));
1005 Error_Msg_N -- CODEFIX
1006 ("\?suggest using an initialized constant object instead",
1013 Check_Constrained_Object;
1015 -- An object renaming requires an exact match of the type. Class-wide
1016 -- matching is not allowed.
1018 if Is_Class_Wide_Type (T)
1019 and then Base_Type (Etype (Nam)) /= Base_Type (T)
1021 Wrong_Type (Nam, T);
1026 -- Ada 2005 (AI-326): Handle wrong use of incomplete type
1028 if Nkind (Nam) = N_Explicit_Dereference
1029 and then Ekind (Etype (T2)) = E_Incomplete_Type
1031 Error_Msg_NE ("invalid use of incomplete type&", Id, T2);
1034 elsif Ekind (Etype (T)) = E_Incomplete_Type then
1035 Error_Msg_NE ("invalid use of incomplete type&", Id, T);
1039 -- Ada 2005 (AI-327)
1041 if Ada_Version >= Ada_2005
1042 and then Nkind (Nam) = N_Attribute_Reference
1043 and then Attribute_Name (Nam) = Name_Priority
1047 elsif Ada_Version >= Ada_2005
1048 and then Nkind (Nam) in N_Has_Entity
1052 Nam_Ent : Entity_Id;
1055 if Nkind (Nam) = N_Attribute_Reference then
1056 Nam_Ent := Entity (Prefix (Nam));
1058 Nam_Ent := Entity (Nam);
1061 Nam_Decl := Parent (Nam_Ent);
1063 if Has_Null_Exclusion (N)
1064 and then not Has_Null_Exclusion (Nam_Decl)
1066 -- Ada 2005 (AI-423): If the object name denotes a generic
1067 -- formal object of a generic unit G, and the object renaming
1068 -- declaration occurs within the body of G or within the body
1069 -- of a generic unit declared within the declarative region
1070 -- of G, then the declaration of the formal object of G must
1071 -- have a null exclusion or a null-excluding subtype.
1073 if Is_Formal_Object (Nam_Ent)
1074 and then In_Generic_Scope (Id)
1076 if not Can_Never_Be_Null (Etype (Nam_Ent)) then
1078 ("renamed formal does not exclude `NULL` "
1079 & "(RM 8.5.1(4.6/2))", N);
1081 elsif In_Package_Body (Scope (Id)) then
1083 ("formal object does not have a null exclusion"
1084 & "(RM 8.5.1(4.6/2))", N);
1087 -- Ada 2005 (AI-423): Otherwise, the subtype of the object name
1088 -- shall exclude null.
1090 elsif not Can_Never_Be_Null (Etype (Nam_Ent)) then
1092 ("renamed object does not exclude `NULL` "
1093 & "(RM 8.5.1(4.6/2))", N);
1095 -- An instance is illegal if it contains a renaming that
1096 -- excludes null, and the actual does not. The renaming
1097 -- declaration has already indicated that the declaration
1098 -- of the renamed actual in the instance will raise
1099 -- constraint_error.
1101 elsif Nkind (Nam_Decl) = N_Object_Declaration
1102 and then In_Instance
1104 (Corresponding_Generic_Association (Nam_Decl))
1105 and then Nkind (Expression (Nam_Decl))
1106 = N_Raise_Constraint_Error
1109 ("renamed actual does not exclude `NULL` "
1110 & "(RM 8.5.1(4.6/2))", N);
1112 -- Finally, if there is a null exclusion, the subtype mark
1113 -- must not be null-excluding.
1115 elsif No (Access_Definition (N))
1116 and then Can_Never_Be_Null (T)
1119 ("`NOT NULL` not allowed (& already excludes null)",
1124 elsif Can_Never_Be_Null (T)
1125 and then not Can_Never_Be_Null (Etype (Nam_Ent))
1128 ("renamed object does not exclude `NULL` "
1129 & "(RM 8.5.1(4.6/2))", N);
1131 elsif Has_Null_Exclusion (N)
1132 and then No (Access_Definition (N))
1133 and then Can_Never_Be_Null (T)
1136 ("`NOT NULL` not allowed (& already excludes null)", N, T);
1141 Set_Ekind (Id, E_Variable);
1143 -- Initialize the object size and alignment. Note that we used to call
1144 -- Init_Size_Align here, but that's wrong for objects which have only
1145 -- an Esize, not an RM_Size field!
1147 Init_Object_Size_Align (Id);
1149 if T = Any_Type or else Etype (Nam) = Any_Type then
1152 -- Verify that the renamed entity is an object or a function call. It
1153 -- may have been rewritten in several ways.
1155 elsif Is_Object_Reference (Nam) then
1156 if Comes_From_Source (N)
1157 and then Is_Dependent_Component_Of_Mutable_Object (Nam)
1160 ("illegal renaming of discriminant-dependent component", Nam);
1163 -- A static function call may have been folded into a literal
1165 elsif Nkind (Original_Node (Nam)) = N_Function_Call
1167 -- When expansion is disabled, attribute reference is not
1168 -- rewritten as function call. Otherwise it may be rewritten
1169 -- as a conversion, so check original node.
1171 or else (Nkind (Original_Node (Nam)) = N_Attribute_Reference
1172 and then Is_Function_Attribute_Name
1173 (Attribute_Name (Original_Node (Nam))))
1175 -- Weird but legal, equivalent to renaming a function call.
1176 -- Illegal if the literal is the result of constant-folding an
1177 -- attribute reference that is not a function.
1179 or else (Is_Entity_Name (Nam)
1180 and then Ekind (Entity (Nam)) = E_Enumeration_Literal
1182 Nkind (Original_Node (Nam)) /= N_Attribute_Reference)
1184 or else (Nkind (Nam) = N_Type_Conversion
1185 and then Is_Tagged_Type (Entity (Subtype_Mark (Nam))))
1189 elsif Nkind (Nam) = N_Type_Conversion then
1191 ("renaming of conversion only allowed for tagged types", Nam);
1193 -- Ada 2005 (AI-327)
1195 elsif Ada_Version >= Ada_2005
1196 and then Nkind (Nam) = N_Attribute_Reference
1197 and then Attribute_Name (Nam) = Name_Priority
1201 -- Allow internally generated x'Reference expression
1203 elsif Nkind (Nam) = N_Reference then
1207 Error_Msg_N ("expect object name in renaming", Nam);
1212 if not Is_Variable (Nam) then
1213 Set_Ekind (Id, E_Constant);
1214 Set_Never_Set_In_Source (Id, True);
1215 Set_Is_True_Constant (Id, True);
1218 Set_Renamed_Object (Id, Nam);
1219 Analyze_Dimension (N);
1220 end Analyze_Object_Renaming;
1222 ------------------------------
1223 -- Analyze_Package_Renaming --
1224 ------------------------------
1226 procedure Analyze_Package_Renaming (N : Node_Id) is
1227 New_P : constant Entity_Id := Defining_Entity (N);
1232 if Name (N) = Error then
1236 -- Apply Text_IO kludge here since we may be renaming a child of Text_IO
1238 Text_IO_Kludge (Name (N));
1240 if Current_Scope /= Standard_Standard then
1241 Set_Is_Pure (New_P, Is_Pure (Current_Scope));
1247 if Is_Entity_Name (Name (N)) then
1248 Old_P := Entity (Name (N));
1253 if Etype (Old_P) = Any_Type then
1254 Error_Msg_N ("expect package name in renaming", Name (N));
1256 elsif Ekind (Old_P) /= E_Package
1257 and then not (Ekind (Old_P) = E_Generic_Package
1258 and then In_Open_Scopes (Old_P))
1260 if Ekind (Old_P) = E_Generic_Package then
1262 ("generic package cannot be renamed as a package", Name (N));
1264 Error_Msg_Sloc := Sloc (Old_P);
1266 ("expect package name in renaming, found& declared#",
1270 -- Set basic attributes to minimize cascaded errors
1272 Set_Ekind (New_P, E_Package);
1273 Set_Etype (New_P, Standard_Void_Type);
1275 -- Here for OK package renaming
1278 -- Entities in the old package are accessible through the renaming
1279 -- entity. The simplest implementation is to have both packages share
1282 Set_Ekind (New_P, E_Package);
1283 Set_Etype (New_P, Standard_Void_Type);
1285 if Present (Renamed_Object (Old_P)) then
1286 Set_Renamed_Object (New_P, Renamed_Object (Old_P));
1288 Set_Renamed_Object (New_P, Old_P);
1291 Set_Has_Completion (New_P);
1293 Set_First_Entity (New_P, First_Entity (Old_P));
1294 Set_Last_Entity (New_P, Last_Entity (Old_P));
1295 Set_First_Private_Entity (New_P, First_Private_Entity (Old_P));
1296 Check_Library_Unit_Renaming (N, Old_P);
1297 Generate_Reference (Old_P, Name (N));
1299 -- If the renaming is in the visible part of a package, then we set
1300 -- Renamed_In_Spec for the renamed package, to prevent giving
1301 -- warnings about no entities referenced. Such a warning would be
1302 -- overenthusiastic, since clients can see entities in the renamed
1303 -- package via the visible package renaming.
1306 Ent : constant Entity_Id := Cunit_Entity (Current_Sem_Unit);
1308 if Ekind (Ent) = E_Package
1309 and then not In_Private_Part (Ent)
1310 and then In_Extended_Main_Source_Unit (N)
1311 and then Ekind (Old_P) = E_Package
1313 Set_Renamed_In_Spec (Old_P);
1317 -- If this is the renaming declaration of a package instantiation
1318 -- within itself, it is the declaration that ends the list of actuals
1319 -- for the instantiation. At this point, the subtypes that rename
1320 -- the actuals are flagged as generic, to avoid spurious ambiguities
1321 -- if the actuals for two distinct formals happen to coincide. If
1322 -- the actual is a private type, the subtype has a private completion
1323 -- that is flagged in the same fashion.
1325 -- Resolution is identical to what is was in the original generic.
1326 -- On exit from the generic instance, these are turned into regular
1327 -- subtypes again, so they are compatible with types in their class.
1329 if not Is_Generic_Instance (Old_P) then
1332 Spec := Specification (Unit_Declaration_Node (Old_P));
1335 if Nkind (Spec) = N_Package_Specification
1336 and then Present (Generic_Parent (Spec))
1337 and then Old_P = Current_Scope
1338 and then Chars (New_P) = Chars (Generic_Parent (Spec))
1344 E := First_Entity (Old_P);
1349 and then Nkind (Parent (E)) = N_Subtype_Declaration
1351 Set_Is_Generic_Actual_Type (E);
1353 if Is_Private_Type (E)
1354 and then Present (Full_View (E))
1356 Set_Is_Generic_Actual_Type (Full_View (E));
1365 end Analyze_Package_Renaming;
1367 -------------------------------
1368 -- Analyze_Renamed_Character --
1369 -------------------------------
1371 procedure Analyze_Renamed_Character
1376 C : constant Node_Id := Name (N);
1379 if Ekind (New_S) = E_Function then
1380 Resolve (C, Etype (New_S));
1383 Check_Frozen_Renaming (N, New_S);
1387 Error_Msg_N ("character literal can only be renamed as function", N);
1389 end Analyze_Renamed_Character;
1391 ---------------------------------
1392 -- Analyze_Renamed_Dereference --
1393 ---------------------------------
1395 procedure Analyze_Renamed_Dereference
1400 Nam : constant Node_Id := Name (N);
1401 P : constant Node_Id := Prefix (Nam);
1407 if not Is_Overloaded (P) then
1408 if Ekind (Etype (Nam)) /= E_Subprogram_Type
1409 or else not Type_Conformant (Etype (Nam), New_S)
1411 Error_Msg_N ("designated type does not match specification", P);
1420 Get_First_Interp (Nam, Ind, It);
1422 while Present (It.Nam) loop
1424 if Ekind (It.Nam) = E_Subprogram_Type
1425 and then Type_Conformant (It.Nam, New_S)
1427 if Typ /= Any_Id then
1428 Error_Msg_N ("ambiguous renaming", P);
1435 Get_Next_Interp (Ind, It);
1438 if Typ = Any_Type then
1439 Error_Msg_N ("designated type does not match specification", P);
1444 Check_Frozen_Renaming (N, New_S);
1448 end Analyze_Renamed_Dereference;
1450 ---------------------------
1451 -- Analyze_Renamed_Entry --
1452 ---------------------------
1454 procedure Analyze_Renamed_Entry
1459 Nam : constant Node_Id := Name (N);
1460 Sel : constant Node_Id := Selector_Name (Nam);
1464 if Entity (Sel) = Any_Id then
1466 -- Selector is undefined on prefix. Error emitted already
1468 Set_Has_Completion (New_S);
1472 -- Otherwise find renamed entity and build body of New_S as a call to it
1474 Old_S := Find_Renamed_Entity (N, Selector_Name (Nam), New_S);
1476 if Old_S = Any_Id then
1477 Error_Msg_N (" no subprogram or entry matches specification", N);
1480 Check_Subtype_Conformant (New_S, Old_S, N);
1481 Generate_Reference (New_S, Defining_Entity (N), 'b');
1482 Style.Check_Identifier (Defining_Entity (N), New_S);
1485 -- Only mode conformance required for a renaming_as_declaration
1487 Check_Mode_Conformant (New_S, Old_S, N);
1490 Inherit_Renamed_Profile (New_S, Old_S);
1492 -- The prefix can be an arbitrary expression that yields a task type,
1493 -- so it must be resolved.
1495 Resolve (Prefix (Nam), Scope (Old_S));
1498 Set_Convention (New_S, Convention (Old_S));
1499 Set_Has_Completion (New_S, Inside_A_Generic);
1502 Check_Frozen_Renaming (N, New_S);
1504 end Analyze_Renamed_Entry;
1506 -----------------------------------
1507 -- Analyze_Renamed_Family_Member --
1508 -----------------------------------
1510 procedure Analyze_Renamed_Family_Member
1515 Nam : constant Node_Id := Name (N);
1516 P : constant Node_Id := Prefix (Nam);
1520 if (Is_Entity_Name (P) and then Ekind (Entity (P)) = E_Entry_Family)
1521 or else (Nkind (P) = N_Selected_Component
1523 Ekind (Entity (Selector_Name (P))) = E_Entry_Family)
1525 if Is_Entity_Name (P) then
1526 Old_S := Entity (P);
1528 Old_S := Entity (Selector_Name (P));
1531 if not Entity_Matches_Spec (Old_S, New_S) then
1532 Error_Msg_N ("entry family does not match specification", N);
1535 Check_Subtype_Conformant (New_S, Old_S, N);
1536 Generate_Reference (New_S, Defining_Entity (N), 'b');
1537 Style.Check_Identifier (Defining_Entity (N), New_S);
1541 Error_Msg_N ("no entry family matches specification", N);
1544 Set_Has_Completion (New_S, Inside_A_Generic);
1547 Check_Frozen_Renaming (N, New_S);
1549 end Analyze_Renamed_Family_Member;
1551 -----------------------------------------
1552 -- Analyze_Renamed_Primitive_Operation --
1553 -----------------------------------------
1555 procedure Analyze_Renamed_Primitive_Operation
1564 Ctyp : Conformance_Type) return Boolean;
1565 -- Verify that the signatures of the renamed entity and the new entity
1566 -- match. The first formal of the renamed entity is skipped because it
1567 -- is the target object in any subsequent call.
1571 Ctyp : Conformance_Type) return Boolean
1577 if Ekind (Subp) /= Ekind (New_S) then
1581 Old_F := Next_Formal (First_Formal (Subp));
1582 New_F := First_Formal (New_S);
1583 while Present (Old_F) and then Present (New_F) loop
1584 if not Conforming_Types (Etype (Old_F), Etype (New_F), Ctyp) then
1588 if Ctyp >= Mode_Conformant
1589 and then Ekind (Old_F) /= Ekind (New_F)
1594 Next_Formal (New_F);
1595 Next_Formal (Old_F);
1602 if not Is_Overloaded (Selector_Name (Name (N))) then
1603 Old_S := Entity (Selector_Name (Name (N)));
1605 if not Conforms (Old_S, Type_Conformant) then
1610 -- Find the operation that matches the given signature
1618 Get_First_Interp (Selector_Name (Name (N)), Ind, It);
1620 while Present (It.Nam) loop
1621 if Conforms (It.Nam, Type_Conformant) then
1625 Get_Next_Interp (Ind, It);
1630 if Old_S = Any_Id then
1631 Error_Msg_N (" no subprogram or entry matches specification", N);
1635 if not Conforms (Old_S, Subtype_Conformant) then
1636 Error_Msg_N ("subtype conformance error in renaming", N);
1639 Generate_Reference (New_S, Defining_Entity (N), 'b');
1640 Style.Check_Identifier (Defining_Entity (N), New_S);
1643 -- Only mode conformance required for a renaming_as_declaration
1645 if not Conforms (Old_S, Mode_Conformant) then
1646 Error_Msg_N ("mode conformance error in renaming", N);
1650 -- Inherit_Renamed_Profile (New_S, Old_S);
1652 -- The prefix can be an arbitrary expression that yields an
1653 -- object, so it must be resolved.
1655 Resolve (Prefix (Name (N)));
1657 end Analyze_Renamed_Primitive_Operation;
1659 ---------------------------------
1660 -- Analyze_Subprogram_Renaming --
1661 ---------------------------------
1663 procedure Analyze_Subprogram_Renaming (N : Node_Id) is
1664 Formal_Spec : constant Node_Id := Corresponding_Formal_Spec (N);
1665 Is_Actual : constant Boolean := Present (Formal_Spec);
1666 Inst_Node : Node_Id := Empty;
1667 Nam : constant Node_Id := Name (N);
1669 Old_S : Entity_Id := Empty;
1670 Rename_Spec : Entity_Id;
1671 Save_AV : constant Ada_Version_Type := Ada_Version;
1672 Save_AV_Exp : constant Ada_Version_Type := Ada_Version_Explicit;
1673 Spec : constant Node_Id := Specification (N);
1675 procedure Check_Null_Exclusion
1678 -- Ada 2005 (AI-423): Given renaming Ren of subprogram Sub, check the
1679 -- following AI rules:
1681 -- If Ren is a renaming of a formal subprogram and one of its
1682 -- parameters has a null exclusion, then the corresponding formal
1683 -- in Sub must also have one. Otherwise the subtype of the Sub's
1684 -- formal parameter must exclude null.
1686 -- If Ren is a renaming of a formal function and its return
1687 -- profile has a null exclusion, then Sub's return profile must
1688 -- have one. Otherwise the subtype of Sub's return profile must
1691 function Original_Subprogram (Subp : Entity_Id) return Entity_Id;
1692 -- Find renamed entity when the declaration is a renaming_as_body and
1693 -- the renamed entity may itself be a renaming_as_body. Used to enforce
1694 -- rule that a renaming_as_body is illegal if the declaration occurs
1695 -- before the subprogram it completes is frozen, and renaming indirectly
1696 -- renames the subprogram itself.(Defect Report 8652/0027).
1698 function Check_Class_Wide_Actual return Entity_Id;
1699 -- AI05-0071: In an instance, if the actual for a formal type FT with
1700 -- unknown discriminants is a class-wide type CT, and the generic has
1701 -- a formal subprogram with a box for a primitive operation of FT,
1702 -- then the corresponding actual subprogram denoted by the default is a
1703 -- class-wide operation whose body is a dispatching call. We replace the
1704 -- generated renaming declaration:
1706 -- procedure P (X : CT) renames P;
1708 -- by a different renaming and a class-wide operation:
1710 -- procedure Pr (X : T) renames P; -- renames primitive operation
1711 -- procedure P (X : CT); -- class-wide operation
1713 -- procedure P (X : CT) is begin Pr (X); end; -- dispatching call
1715 -- This rule only applies if there is no explicit visible class-wide
1716 -- operation at the point of the instantiation.
1718 function Has_Class_Wide_Actual return Boolean;
1719 -- Ada 2012 (AI05-071, AI05-0131): True if N is the renaming for a
1720 -- defaulted formal subprogram when the actual for the controlling
1721 -- formal type is class-wide.
1723 -----------------------------
1724 -- Check_Class_Wide_Actual --
1725 -----------------------------
1727 function Check_Class_Wide_Actual return Entity_Id is
1728 Loc : constant Source_Ptr := Sloc (N);
1731 Formal_Type : Entity_Id;
1732 Actual_Type : Entity_Id;
1737 function Make_Call (Prim_Op : Entity_Id) return Node_Id;
1738 -- Build dispatching call for body of class-wide operation
1740 function Make_Spec return Node_Id;
1741 -- Create subprogram specification for declaration and body of
1742 -- class-wide operation, using signature of renaming declaration.
1748 function Make_Call (Prim_Op : Entity_Id) return Node_Id is
1753 Actuals := New_List;
1754 F := First (Parameter_Specifications (Specification (New_Decl)));
1755 while Present (F) loop
1757 Make_Identifier (Loc, Chars (Defining_Identifier (F))));
1761 if Ekind_In (Prim_Op, E_Function, E_Operator) then
1762 return Make_Simple_Return_Statement (Loc,
1764 Make_Function_Call (Loc,
1765 Name => New_Occurrence_Of (Prim_Op, Loc),
1766 Parameter_Associations => Actuals));
1769 Make_Procedure_Call_Statement (Loc,
1770 Name => New_Occurrence_Of (Prim_Op, Loc),
1771 Parameter_Associations => Actuals);
1779 function Make_Spec return Node_Id is
1780 Param_Specs : constant List_Id := Copy_Parameter_List (New_S);
1783 if Ekind (New_S) = E_Procedure then
1785 Make_Procedure_Specification (Loc,
1786 Defining_Unit_Name =>
1787 Make_Defining_Identifier (Loc,
1788 Chars (Defining_Unit_Name (Spec))),
1789 Parameter_Specifications => Param_Specs);
1792 Make_Function_Specification (Loc,
1793 Defining_Unit_Name =>
1794 Make_Defining_Identifier (Loc,
1795 Chars (Defining_Unit_Name (Spec))),
1796 Parameter_Specifications => Param_Specs,
1797 Result_Definition =>
1798 New_Copy_Tree (Result_Definition (Spec)));
1802 -- Start of processing for Check_Class_Wide_Actual
1806 Formal_Type := Empty;
1807 Actual_Type := Empty;
1809 F := First_Formal (Formal_Spec);
1810 while Present (F) loop
1811 if Has_Unknown_Discriminants (Etype (F))
1812 and then not Is_Class_Wide_Type (Etype (F))
1813 and then Is_Class_Wide_Type (Get_Instance_Of (Etype (F)))
1815 Formal_Type := Etype (F);
1816 Actual_Type := Etype (Get_Instance_Of (Formal_Type));
1823 if Present (Formal_Type) then
1825 -- Create declaration and body for class-wide operation
1828 Make_Subprogram_Declaration (Loc, Specification => Make_Spec);
1831 Make_Subprogram_Body (Loc,
1832 Specification => Make_Spec,
1833 Declarations => No_List,
1834 Handled_Statement_Sequence =>
1835 Make_Handled_Sequence_Of_Statements (Loc, New_List));
1837 -- Modify Spec and create internal name for renaming of primitive
1840 Set_Defining_Unit_Name (Spec, Make_Temporary (Loc, 'R'));
1841 F := First (Parameter_Specifications (Spec));
1842 while Present (F) loop
1843 if Nkind (Parameter_Type (F)) = N_Identifier
1844 and then Is_Class_Wide_Type (Entity (Parameter_Type (F)))
1846 Set_Parameter_Type (F, New_Occurrence_Of (Actual_Type, Loc));
1851 New_S := Analyze_Subprogram_Specification (Spec);
1852 Result := Find_Renamed_Entity (N, Name (N), New_S, Is_Actual);
1855 if Result /= Any_Id then
1856 Insert_Before (N, New_Decl);
1859 -- Add dispatching call to body of class-wide operation
1861 Append (Make_Call (Result),
1862 Statements (Handled_Statement_Sequence (New_Body)));
1864 -- The generated body does not freeze. It is analyzed when the
1865 -- generated operation is frozen. This body is only needed if
1866 -- expansion is enabled.
1868 if Expander_Active then
1869 Append_Freeze_Action (Defining_Entity (New_Decl), New_Body);
1872 Result := Defining_Entity (New_Decl);
1875 -- Return the class-wide operation if one was created
1878 end Check_Class_Wide_Actual;
1880 --------------------------
1881 -- Check_Null_Exclusion --
1882 --------------------------
1884 procedure Check_Null_Exclusion
1888 Ren_Formal : Entity_Id;
1889 Sub_Formal : Entity_Id;
1894 Ren_Formal := First_Formal (Ren);
1895 Sub_Formal := First_Formal (Sub);
1896 while Present (Ren_Formal)
1897 and then Present (Sub_Formal)
1899 if Has_Null_Exclusion (Parent (Ren_Formal))
1901 not (Has_Null_Exclusion (Parent (Sub_Formal))
1902 or else Can_Never_Be_Null (Etype (Sub_Formal)))
1905 ("`NOT NULL` required for parameter &",
1906 Parent (Sub_Formal), Sub_Formal);
1909 Next_Formal (Ren_Formal);
1910 Next_Formal (Sub_Formal);
1913 -- Return profile check
1915 if Nkind (Parent (Ren)) = N_Function_Specification
1916 and then Nkind (Parent (Sub)) = N_Function_Specification
1917 and then Has_Null_Exclusion (Parent (Ren))
1919 not (Has_Null_Exclusion (Parent (Sub))
1920 or else Can_Never_Be_Null (Etype (Sub)))
1923 ("return must specify `NOT NULL`",
1924 Result_Definition (Parent (Sub)));
1926 end Check_Null_Exclusion;
1928 ---------------------------
1929 -- Has_Class_Wide_Actual --
1930 ---------------------------
1932 function Has_Class_Wide_Actual return Boolean is
1938 and then Nkind (Nam) in N_Has_Entity
1939 and then Present (Entity (Nam))
1940 and then Is_Dispatching_Operation (Entity (Nam))
1942 F_Nam := First_Entity (Entity (Nam));
1943 F_Spec := First_Formal (Formal_Spec);
1944 while Present (F_Nam)
1945 and then Present (F_Spec)
1947 if Is_Controlling_Formal (F_Nam)
1948 and then Has_Unknown_Discriminants (Etype (F_Spec))
1949 and then not Is_Class_Wide_Type (Etype (F_Spec))
1950 and then Is_Class_Wide_Type (Get_Instance_Of (Etype (F_Spec)))
1955 Next_Entity (F_Nam);
1956 Next_Formal (F_Spec);
1961 end Has_Class_Wide_Actual;
1963 -------------------------
1964 -- Original_Subprogram --
1965 -------------------------
1967 function Original_Subprogram (Subp : Entity_Id) return Entity_Id is
1968 Orig_Decl : Node_Id;
1969 Orig_Subp : Entity_Id;
1972 -- First case: renamed entity is itself a renaming
1974 if Present (Alias (Subp)) then
1975 return Alias (Subp);
1978 Nkind (Unit_Declaration_Node (Subp)) = N_Subprogram_Declaration
1980 (Corresponding_Body (Unit_Declaration_Node (Subp)))
1982 -- Check if renamed entity is a renaming_as_body
1985 Unit_Declaration_Node
1986 (Corresponding_Body (Unit_Declaration_Node (Subp)));
1988 if Nkind (Orig_Decl) = N_Subprogram_Renaming_Declaration then
1989 Orig_Subp := Entity (Name (Orig_Decl));
1991 if Orig_Subp = Rename_Spec then
1993 -- Circularity detected
1998 return (Original_Subprogram (Orig_Subp));
2006 end Original_Subprogram;
2008 CW_Actual : constant Boolean := Has_Class_Wide_Actual;
2009 -- Ada 2012 (AI05-071, AI05-0131): True if the renaming is for a
2010 -- defaulted formal subprogram when the actual for a related formal
2011 -- type is class-wide.
2013 -- Start of processing for Analyze_Subprogram_Renaming
2016 -- We must test for the attribute renaming case before the Analyze
2017 -- call because otherwise Sem_Attr will complain that the attribute
2018 -- is missing an argument when it is analyzed.
2020 if Nkind (Nam) = N_Attribute_Reference then
2022 -- In the case of an abstract formal subprogram association, rewrite
2023 -- an actual given by a stream attribute as the name of the
2024 -- corresponding stream primitive of the type.
2026 -- In a generic context the stream operations are not generated, and
2027 -- this must be treated as a normal attribute reference, to be
2028 -- expanded in subsequent instantiations.
2030 if Is_Actual and then Is_Abstract_Subprogram (Formal_Spec)
2031 and then Full_Expander_Active
2034 Stream_Prim : Entity_Id;
2035 Prefix_Type : constant Entity_Id := Entity (Prefix (Nam));
2038 -- The class-wide forms of the stream attributes are not
2039 -- primitive dispatching operations (even though they
2040 -- internally dispatch to a stream attribute).
2042 if Is_Class_Wide_Type (Prefix_Type) then
2044 ("attribute must be a primitive dispatching operation",
2049 -- Retrieve the primitive subprogram associated with the
2050 -- attribute. This can only be a stream attribute, since those
2051 -- are the only ones that are dispatching (and the actual for
2052 -- an abstract formal subprogram must be dispatching
2056 case Attribute_Name (Nam) is
2059 Find_Prim_Op (Prefix_Type, TSS_Stream_Input);
2062 Find_Prim_Op (Prefix_Type, TSS_Stream_Output);
2065 Find_Prim_Op (Prefix_Type, TSS_Stream_Read);
2068 Find_Prim_Op (Prefix_Type, TSS_Stream_Write);
2071 ("attribute must be a primitive"
2072 & " dispatching operation", Nam);
2078 -- If no operation was found, and the type is limited,
2079 -- the user should have defined one.
2081 when Program_Error =>
2082 if Is_Limited_Type (Prefix_Type) then
2084 ("stream operation not defined for type&",
2088 -- Otherwise, compiler should have generated default
2095 -- Rewrite the attribute into the name of its corresponding
2096 -- primitive dispatching subprogram. We can then proceed with
2097 -- the usual processing for subprogram renamings.
2100 Prim_Name : constant Node_Id :=
2101 Make_Identifier (Sloc (Nam),
2102 Chars => Chars (Stream_Prim));
2104 Set_Entity (Prim_Name, Stream_Prim);
2105 Rewrite (Nam, Prim_Name);
2110 -- Normal processing for a renaming of an attribute
2113 Attribute_Renaming (N);
2118 -- Check whether this declaration corresponds to the instantiation
2119 -- of a formal subprogram.
2121 -- If this is an instantiation, the corresponding actual is frozen and
2122 -- error messages can be made more precise. If this is a default
2123 -- subprogram, the entity is already established in the generic, and is
2124 -- not retrieved by visibility. If it is a default with a box, the
2125 -- candidate interpretations, if any, have been collected when building
2126 -- the renaming declaration. If overloaded, the proper interpretation is
2127 -- determined in Find_Renamed_Entity. If the entity is an operator,
2128 -- Find_Renamed_Entity applies additional visibility checks.
2131 Inst_Node := Unit_Declaration_Node (Formal_Spec);
2133 -- Check whether the renaming is for a defaulted actual subprogram
2134 -- with a class-wide actual.
2137 New_S := Analyze_Subprogram_Specification (Spec);
2138 Old_S := Check_Class_Wide_Actual;
2140 elsif Is_Entity_Name (Nam)
2141 and then Present (Entity (Nam))
2142 and then not Comes_From_Source (Nam)
2143 and then not Is_Overloaded (Nam)
2145 Old_S := Entity (Nam);
2146 New_S := Analyze_Subprogram_Specification (Spec);
2150 if Ekind (Entity (Nam)) = E_Operator then
2154 if Box_Present (Inst_Node) then
2155 Old_S := Find_Renamed_Entity (N, Name (N), New_S, Is_Actual);
2157 -- If there is an immediately visible homonym of the operator
2158 -- and the declaration has a default, this is worth a warning
2159 -- because the user probably did not intend to get the pre-
2160 -- defined operator, visible in the generic declaration. To
2161 -- find if there is an intended candidate, analyze the renaming
2162 -- again in the current context.
2164 elsif Scope (Old_S) = Standard_Standard
2165 and then Present (Default_Name (Inst_Node))
2168 Decl : constant Node_Id := New_Copy_Tree (N);
2172 Set_Entity (Name (Decl), Empty);
2173 Analyze (Name (Decl));
2175 Find_Renamed_Entity (Decl, Name (Decl), New_S, True);
2178 and then In_Open_Scopes (Scope (Hidden))
2179 and then Is_Immediately_Visible (Hidden)
2180 and then Comes_From_Source (Hidden)
2181 and then Hidden /= Old_S
2183 Error_Msg_Sloc := Sloc (Hidden);
2184 Error_Msg_N ("?default subprogram is resolved " &
2185 "in the generic declaration " &
2186 "(RM 12.6(17))", N);
2187 Error_Msg_NE ("\?and will not use & #", N, Hidden);
2195 New_S := Analyze_Subprogram_Specification (Spec);
2199 -- Renamed entity must be analyzed first, to avoid being hidden by
2200 -- new name (which might be the same in a generic instance).
2204 -- The renaming defines a new overloaded entity, which is analyzed
2205 -- like a subprogram declaration.
2207 New_S := Analyze_Subprogram_Specification (Spec);
2210 if Current_Scope /= Standard_Standard then
2211 Set_Is_Pure (New_S, Is_Pure (Current_Scope));
2214 Rename_Spec := Find_Corresponding_Spec (N);
2216 -- Case of Renaming_As_Body
2218 if Present (Rename_Spec) then
2220 -- Renaming declaration is the completion of the declaration of
2221 -- Rename_Spec. We build an actual body for it at the freezing point.
2223 Set_Corresponding_Spec (N, Rename_Spec);
2225 -- Deal with special case of stream functions of abstract types
2228 if Nkind (Unit_Declaration_Node (Rename_Spec)) =
2229 N_Abstract_Subprogram_Declaration
2231 -- Input stream functions are abstract if the object type is
2232 -- abstract. Similarly, all default stream functions for an
2233 -- interface type are abstract. However, these subprograms may
2234 -- receive explicit declarations in representation clauses, making
2235 -- the attribute subprograms usable as defaults in subsequent
2237 -- In this case we rewrite the declaration to make the subprogram
2238 -- non-abstract. We remove the previous declaration, and insert
2239 -- the new one at the point of the renaming, to prevent premature
2240 -- access to unfrozen types. The new declaration reuses the
2241 -- specification of the previous one, and must not be analyzed.
2244 (Is_Primitive (Entity (Nam))
2246 Is_Abstract_Type (Find_Dispatching_Type (Entity (Nam))));
2248 Old_Decl : constant Node_Id :=
2249 Unit_Declaration_Node (Rename_Spec);
2250 New_Decl : constant Node_Id :=
2251 Make_Subprogram_Declaration (Sloc (N),
2253 Relocate_Node (Specification (Old_Decl)));
2256 Insert_After (N, New_Decl);
2257 Set_Is_Abstract_Subprogram (Rename_Spec, False);
2258 Set_Analyzed (New_Decl);
2262 Set_Corresponding_Body (Unit_Declaration_Node (Rename_Spec), New_S);
2264 if Ada_Version = Ada_83 and then Comes_From_Source (N) then
2265 Error_Msg_N ("(Ada 83) renaming cannot serve as a body", N);
2268 Set_Convention (New_S, Convention (Rename_Spec));
2269 Check_Fully_Conformant (New_S, Rename_Spec);
2270 Set_Public_Status (New_S);
2272 -- The specification does not introduce new formals, but only
2273 -- repeats the formals of the original subprogram declaration.
2274 -- For cross-reference purposes, and for refactoring tools, we
2275 -- treat the formals of the renaming declaration as body formals.
2277 Reference_Body_Formals (Rename_Spec, New_S);
2279 -- Indicate that the entity in the declaration functions like the
2280 -- corresponding body, and is not a new entity. The body will be
2281 -- constructed later at the freeze point, so indicate that the
2282 -- completion has not been seen yet.
2284 Set_Ekind (New_S, E_Subprogram_Body);
2285 New_S := Rename_Spec;
2286 Set_Has_Completion (Rename_Spec, False);
2288 -- Ada 2005: check overriding indicator
2290 if Present (Overridden_Operation (Rename_Spec)) then
2291 if Must_Not_Override (Specification (N)) then
2293 ("subprogram& overrides inherited operation",
2296 Style_Check and then not Must_Override (Specification (N))
2298 Style.Missing_Overriding (N, Rename_Spec);
2301 elsif Must_Override (Specification (N)) then
2302 Error_Msg_NE ("subprogram& is not overriding", N, Rename_Spec);
2305 -- Normal subprogram renaming (not renaming as body)
2308 Generate_Definition (New_S);
2309 New_Overloaded_Entity (New_S);
2311 if Is_Entity_Name (Nam)
2312 and then Is_Intrinsic_Subprogram (Entity (Nam))
2316 Check_Delayed_Subprogram (New_S);
2320 -- There is no need for elaboration checks on the new entity, which may
2321 -- be called before the next freezing point where the body will appear.
2322 -- Elaboration checks refer to the real entity, not the one created by
2323 -- the renaming declaration.
2325 Set_Kill_Elaboration_Checks (New_S, True);
2327 if Etype (Nam) = Any_Type then
2328 Set_Has_Completion (New_S);
2331 elsif Nkind (Nam) = N_Selected_Component then
2333 -- A prefix of the form A.B can designate an entry of task A, a
2334 -- protected operation of protected object A, or finally a primitive
2335 -- operation of object A. In the later case, A is an object of some
2336 -- tagged type, or an access type that denotes one such. To further
2337 -- distinguish these cases, note that the scope of a task entry or
2338 -- protected operation is type of the prefix.
2340 -- The prefix could be an overloaded function call that returns both
2341 -- kinds of operations. This overloading pathology is left to the
2342 -- dedicated reader ???
2345 T : constant Entity_Id := Etype (Prefix (Nam));
2354 Is_Tagged_Type (Designated_Type (T))))
2355 and then Scope (Entity (Selector_Name (Nam))) /= T
2357 Analyze_Renamed_Primitive_Operation
2358 (N, New_S, Present (Rename_Spec));
2362 -- Renamed entity is an entry or protected operation. For those
2363 -- cases an explicit body is built (at the point of freezing of
2364 -- this entity) that contains a call to the renamed entity.
2366 -- This is not allowed for renaming as body if the renamed
2367 -- spec is already frozen (see RM 8.5.4(5) for details).
2369 if Present (Rename_Spec)
2370 and then Is_Frozen (Rename_Spec)
2373 ("renaming-as-body cannot rename entry as subprogram", N);
2375 ("\since & is already frozen (RM 8.5.4(5))",
2378 Analyze_Renamed_Entry (N, New_S, Present (Rename_Spec));
2385 elsif Nkind (Nam) = N_Explicit_Dereference then
2387 -- Renamed entity is designated by access_to_subprogram expression.
2388 -- Must build body to encapsulate call, as in the entry case.
2390 Analyze_Renamed_Dereference (N, New_S, Present (Rename_Spec));
2393 elsif Nkind (Nam) = N_Indexed_Component then
2394 Analyze_Renamed_Family_Member (N, New_S, Present (Rename_Spec));
2397 elsif Nkind (Nam) = N_Character_Literal then
2398 Analyze_Renamed_Character (N, New_S, Present (Rename_Spec));
2401 elsif not Is_Entity_Name (Nam)
2402 or else not Is_Overloadable (Entity (Nam))
2404 -- Do not mention the renaming if it comes from an instance
2406 if not Is_Actual then
2407 Error_Msg_N ("expect valid subprogram name in renaming", N);
2409 Error_Msg_NE ("no visible subprogram for formal&", N, Nam);
2415 -- Find the renamed entity that matches the given specification. Disable
2416 -- Ada_83 because there is no requirement of full conformance between
2417 -- renamed entity and new entity, even though the same circuit is used.
2419 -- This is a bit of a kludge, which introduces a really irregular use of
2420 -- Ada_Version[_Explicit]. Would be nice to find cleaner way to do this
2423 Ada_Version := Ada_Version_Type'Max (Ada_Version, Ada_95);
2424 Ada_Version_Explicit := Ada_Version;
2427 Old_S := Find_Renamed_Entity (N, Name (N), New_S, Is_Actual);
2429 -- The visible operation may be an inherited abstract operation that
2430 -- was overridden in the private part, in which case a call will
2431 -- dispatch to the overriding operation. Use the overriding one in
2432 -- the renaming declaration, to prevent spurious errors below.
2434 if Is_Overloadable (Old_S)
2435 and then Is_Abstract_Subprogram (Old_S)
2436 and then No (DTC_Entity (Old_S))
2437 and then Present (Alias (Old_S))
2438 and then not Is_Abstract_Subprogram (Alias (Old_S))
2439 and then Present (Overridden_Operation (Alias (Old_S)))
2441 Old_S := Alias (Old_S);
2444 -- When the renamed subprogram is overloaded and used as an actual
2445 -- of a generic, its entity is set to the first available homonym.
2446 -- We must first disambiguate the name, then set the proper entity.
2448 if Is_Actual and then Is_Overloaded (Nam) then
2449 Set_Entity (Nam, Old_S);
2453 -- Most common case: subprogram renames subprogram. No body is generated
2454 -- in this case, so we must indicate the declaration is complete as is.
2455 -- and inherit various attributes of the renamed subprogram.
2457 if No (Rename_Spec) then
2458 Set_Has_Completion (New_S);
2459 Set_Is_Imported (New_S, Is_Imported (Entity (Nam)));
2460 Set_Is_Pure (New_S, Is_Pure (Entity (Nam)));
2461 Set_Is_Preelaborated (New_S, Is_Preelaborated (Entity (Nam)));
2463 -- Ada 2005 (AI-423): Check the consistency of null exclusions
2464 -- between a subprogram and its correct renaming.
2466 -- Note: the Any_Id check is a guard that prevents compiler crashes
2467 -- when performing a null exclusion check between a renaming and a
2468 -- renamed subprogram that has been found to be illegal.
2470 if Ada_Version >= Ada_2005
2471 and then Entity (Nam) /= Any_Id
2473 Check_Null_Exclusion
2475 Sub => Entity (Nam));
2478 -- Enforce the Ada 2005 rule that the renamed entity cannot require
2479 -- overriding. The flag Requires_Overriding is set very selectively
2480 -- and misses some other illegal cases. The additional conditions
2481 -- checked below are sufficient but not necessary ???
2483 -- The rule does not apply to the renaming generated for an actual
2484 -- subprogram in an instance.
2489 -- Guard against previous errors, and omit renamings of predefined
2492 elsif not Ekind_In (Old_S, E_Function, E_Procedure) then
2495 elsif Requires_Overriding (Old_S)
2497 (Is_Abstract_Subprogram (Old_S)
2498 and then Present (Find_Dispatching_Type (Old_S))
2500 not Is_Abstract_Type (Find_Dispatching_Type (Old_S)))
2503 ("renamed entity cannot be "
2504 & "subprogram that requires overriding (RM 8.5.4 (5.1))", N);
2508 if Old_S /= Any_Id then
2509 if Is_Actual and then From_Default (N) then
2511 -- This is an implicit reference to the default actual
2513 Generate_Reference (Old_S, Nam, Typ => 'i', Force => True);
2516 Generate_Reference (Old_S, Nam);
2519 -- For a renaming-as-body, require subtype conformance, but if the
2520 -- declaration being completed has not been frozen, then inherit the
2521 -- convention of the renamed subprogram prior to checking conformance
2522 -- (unless the renaming has an explicit convention established; the
2523 -- rule stated in the RM doesn't seem to address this ???).
2525 if Present (Rename_Spec) then
2526 Generate_Reference (Rename_Spec, Defining_Entity (Spec), 'b');
2527 Style.Check_Identifier (Defining_Entity (Spec), Rename_Spec);
2529 if not Is_Frozen (Rename_Spec) then
2530 if not Has_Convention_Pragma (Rename_Spec) then
2531 Set_Convention (New_S, Convention (Old_S));
2534 if Ekind (Old_S) /= E_Operator then
2535 Check_Mode_Conformant (New_S, Old_S, Spec);
2538 if Original_Subprogram (Old_S) = Rename_Spec then
2539 Error_Msg_N ("unfrozen subprogram cannot rename itself ", N);
2542 Check_Subtype_Conformant (New_S, Old_S, Spec);
2545 Check_Frozen_Renaming (N, Rename_Spec);
2547 -- Check explicitly that renamed entity is not intrinsic, because
2548 -- in a generic the renamed body is not built. In this case,
2549 -- the renaming_as_body is a completion.
2551 if Inside_A_Generic then
2552 if Is_Frozen (Rename_Spec)
2553 and then Is_Intrinsic_Subprogram (Old_S)
2556 ("subprogram in renaming_as_body cannot be intrinsic",
2560 Set_Has_Completion (Rename_Spec);
2563 elsif Ekind (Old_S) /= E_Operator then
2565 -- If this a defaulted subprogram for a class-wide actual there is
2566 -- no check for mode conformance, given that the signatures don't
2567 -- match (the source mentions T but the actual mentions T'Class).
2572 Check_Mode_Conformant (New_S, Old_S);
2576 and then Error_Posted (New_S)
2578 Error_Msg_NE ("invalid actual subprogram: & #!", N, Old_S);
2582 if No (Rename_Spec) then
2584 -- The parameter profile of the new entity is that of the renamed
2585 -- entity: the subtypes given in the specification are irrelevant.
2587 Inherit_Renamed_Profile (New_S, Old_S);
2589 -- A call to the subprogram is transformed into a call to the
2590 -- renamed entity. This is transitive if the renamed entity is
2591 -- itself a renaming.
2593 if Present (Alias (Old_S)) then
2594 Set_Alias (New_S, Alias (Old_S));
2596 Set_Alias (New_S, Old_S);
2599 -- Note that we do not set Is_Intrinsic_Subprogram if we have a
2600 -- renaming as body, since the entity in this case is not an
2601 -- intrinsic (it calls an intrinsic, but we have a real body for
2602 -- this call, and it is in this body that the required intrinsic
2603 -- processing will take place).
2605 -- Also, if this is a renaming of inequality, the renamed operator
2606 -- is intrinsic, but what matters is the corresponding equality
2607 -- operator, which may be user-defined.
2609 Set_Is_Intrinsic_Subprogram
2611 Is_Intrinsic_Subprogram (Old_S)
2613 (Chars (Old_S) /= Name_Op_Ne
2614 or else Ekind (Old_S) = E_Operator
2616 Is_Intrinsic_Subprogram
2617 (Corresponding_Equality (Old_S))));
2619 if Ekind (Alias (New_S)) = E_Operator then
2620 Set_Has_Delayed_Freeze (New_S, False);
2623 -- If the renaming corresponds to an association for an abstract
2624 -- formal subprogram, then various attributes must be set to
2625 -- indicate that the renaming is an abstract dispatching operation
2626 -- with a controlling type.
2628 if Is_Actual and then Is_Abstract_Subprogram (Formal_Spec) then
2630 -- Mark the renaming as abstract here, so Find_Dispatching_Type
2631 -- see it as corresponding to a generic association for a
2632 -- formal abstract subprogram
2634 Set_Is_Abstract_Subprogram (New_S);
2637 New_S_Ctrl_Type : constant Entity_Id :=
2638 Find_Dispatching_Type (New_S);
2639 Old_S_Ctrl_Type : constant Entity_Id :=
2640 Find_Dispatching_Type (Old_S);
2643 if Old_S_Ctrl_Type /= New_S_Ctrl_Type then
2645 ("actual must be dispatching subprogram for type&",
2646 Nam, New_S_Ctrl_Type);
2649 Set_Is_Dispatching_Operation (New_S);
2650 Check_Controlling_Formals (New_S_Ctrl_Type, New_S);
2652 -- If the actual in the formal subprogram is itself a
2653 -- formal abstract subprogram association, there's no
2654 -- dispatch table component or position to inherit.
2656 if Present (DTC_Entity (Old_S)) then
2657 Set_DTC_Entity (New_S, DTC_Entity (Old_S));
2658 Set_DT_Position (New_S, DT_Position (Old_S));
2666 and then (Old_S = New_S
2668 (Nkind (Nam) /= N_Expanded_Name
2669 and then Chars (Old_S) = Chars (New_S))
2671 (Nkind (Nam) = N_Expanded_Name
2672 and then Entity (Prefix (Nam)) = Current_Scope
2674 Chars (Selector_Name (Nam)) = Chars (New_S)))
2676 Error_Msg_N ("subprogram cannot rename itself", N);
2679 Set_Convention (New_S, Convention (Old_S));
2681 if Is_Abstract_Subprogram (Old_S) then
2682 if Present (Rename_Spec) then
2684 ("a renaming-as-body cannot rename an abstract subprogram",
2686 Set_Has_Completion (Rename_Spec);
2688 Set_Is_Abstract_Subprogram (New_S);
2692 Check_Library_Unit_Renaming (N, Old_S);
2694 -- Pathological case: procedure renames entry in the scope of its
2695 -- task. Entry is given by simple name, but body must be built for
2696 -- procedure. Of course if called it will deadlock.
2698 if Ekind (Old_S) = E_Entry then
2699 Set_Has_Completion (New_S, False);
2700 Set_Alias (New_S, Empty);
2704 Freeze_Before (N, Old_S);
2705 Set_Has_Delayed_Freeze (New_S, False);
2706 Freeze_Before (N, New_S);
2708 -- An abstract subprogram is only allowed as an actual in the case
2709 -- where the formal subprogram is also abstract.
2711 if (Ekind (Old_S) = E_Procedure or else Ekind (Old_S) = E_Function)
2712 and then Is_Abstract_Subprogram (Old_S)
2713 and then not Is_Abstract_Subprogram (Formal_Spec)
2716 ("abstract subprogram not allowed as generic actual", Nam);
2721 -- A common error is to assume that implicit operators for types are
2722 -- defined in Standard, or in the scope of a subtype. In those cases
2723 -- where the renamed entity is given with an expanded name, it is
2724 -- worth mentioning that operators for the type are not declared in
2725 -- the scope given by the prefix.
2727 if Nkind (Nam) = N_Expanded_Name
2728 and then Nkind (Selector_Name (Nam)) = N_Operator_Symbol
2729 and then Scope (Entity (Nam)) = Standard_Standard
2732 T : constant Entity_Id :=
2733 Base_Type (Etype (First_Formal (New_S)));
2735 Error_Msg_Node_2 := Prefix (Nam);
2737 ("operator for type& is not declared in&", Prefix (Nam), T);
2742 ("no visible subprogram matches the specification for&",
2746 if Present (Candidate_Renaming) then
2753 F1 := First_Formal (Candidate_Renaming);
2754 F2 := First_Formal (New_S);
2755 T1 := First_Subtype (Etype (F1));
2757 while Present (F1) and then Present (F2) loop
2762 if Present (F1) and then Present (Default_Value (F1)) then
2763 if Present (Next_Formal (F1)) then
2765 ("\missing specification for &" &
2766 " and other formals with defaults", Spec, F1);
2769 ("\missing specification for &", Spec, F1);
2773 if Nkind (Nam) = N_Operator_Symbol
2774 and then From_Default (N)
2776 Error_Msg_Node_2 := T1;
2778 ("default & on & is not directly visible",
2785 -- Ada 2005 AI 404: if the new subprogram is dispatching, verify that
2786 -- controlling access parameters are known non-null for the renamed
2787 -- subprogram. Test also applies to a subprogram instantiation that
2788 -- is dispatching. Test is skipped if some previous error was detected
2789 -- that set Old_S to Any_Id.
2791 if Ada_Version >= Ada_2005
2792 and then Old_S /= Any_Id
2793 and then not Is_Dispatching_Operation (Old_S)
2794 and then Is_Dispatching_Operation (New_S)
2801 Old_F := First_Formal (Old_S);
2802 New_F := First_Formal (New_S);
2803 while Present (Old_F) loop
2804 if Ekind (Etype (Old_F)) = E_Anonymous_Access_Type
2805 and then Is_Controlling_Formal (New_F)
2806 and then not Can_Never_Be_Null (Old_F)
2808 Error_Msg_N ("access parameter is controlling,", New_F);
2810 ("\corresponding parameter of& "
2811 & "must be explicitly null excluding", New_F, Old_S);
2814 Next_Formal (Old_F);
2815 Next_Formal (New_F);
2820 -- A useful warning, suggested by Ada Bug Finder (Ada-Europe 2005)
2821 -- is to warn if an operator is being renamed as a different operator.
2822 -- If the operator is predefined, examine the kind of the entity, not
2823 -- the abbreviated declaration in Standard.
2825 if Comes_From_Source (N)
2826 and then Present (Old_S)
2828 (Nkind (Old_S) = N_Defining_Operator_Symbol
2829 or else Ekind (Old_S) = E_Operator)
2830 and then Nkind (New_S) = N_Defining_Operator_Symbol
2831 and then Chars (Old_S) /= Chars (New_S)
2834 ("?& is being renamed as a different operator", N, Old_S);
2837 -- Check for renaming of obsolescent subprogram
2839 Check_Obsolescent_2005_Entity (Entity (Nam), Nam);
2841 -- Another warning or some utility: if the new subprogram as the same
2842 -- name as the old one, the old one is not hidden by an outer homograph,
2843 -- the new one is not a public symbol, and the old one is otherwise
2844 -- directly visible, the renaming is superfluous.
2846 if Chars (Old_S) = Chars (New_S)
2847 and then Comes_From_Source (N)
2848 and then Scope (Old_S) /= Standard_Standard
2849 and then Warn_On_Redundant_Constructs
2851 (Is_Immediately_Visible (Old_S)
2852 or else Is_Potentially_Use_Visible (Old_S))
2853 and then Is_Overloadable (Current_Scope)
2854 and then Chars (Current_Scope) /= Chars (Old_S)
2857 ("?redundant renaming, entity is directly visible", Name (N));
2860 -- Implementation-defined aspect specifications can appear in a renaming
2861 -- declaration, but not language-defined ones. The call to procedure
2862 -- Analyze_Aspect_Specifications will take care of this error check.
2864 if Has_Aspects (N) then
2865 Analyze_Aspect_Specifications (N, New_S);
2868 Ada_Version := Save_AV;
2869 Ada_Version_Explicit := Save_AV_Exp;
2870 end Analyze_Subprogram_Renaming;
2872 -------------------------
2873 -- Analyze_Use_Package --
2874 -------------------------
2876 -- Resolve the package names in the use clause, and make all the visible
2877 -- entities defined in the package potentially use-visible. If the package
2878 -- is already in use from a previous use clause, its visible entities are
2879 -- already use-visible. In that case, mark the occurrence as a redundant
2880 -- use. If the package is an open scope, i.e. if the use clause occurs
2881 -- within the package itself, ignore it.
2883 procedure Analyze_Use_Package (N : Node_Id) is
2884 Pack_Name : Node_Id;
2887 -- Start of processing for Analyze_Use_Package
2890 Check_SPARK_Restriction ("use clause is not allowed", N);
2892 Set_Hidden_By_Use_Clause (N, No_Elist);
2894 -- Use clause not allowed in a spec of a predefined package declaration
2895 -- except that packages whose file name starts a-n are OK (these are
2896 -- children of Ada.Numerics, which are never loaded by Rtsfind).
2898 if Is_Predefined_File_Name (Unit_File_Name (Current_Sem_Unit))
2899 and then Name_Buffer (1 .. 3) /= "a-n"
2901 Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Declaration
2903 Error_Msg_N ("use clause not allowed in predefined spec", N);
2906 -- Chain clause to list of use clauses in current scope
2908 if Nkind (Parent (N)) /= N_Compilation_Unit then
2909 Chain_Use_Clause (N);
2912 -- Loop through package names to identify referenced packages
2914 Pack_Name := First (Names (N));
2915 while Present (Pack_Name) loop
2916 Analyze (Pack_Name);
2918 if Nkind (Parent (N)) = N_Compilation_Unit
2919 and then Nkind (Pack_Name) = N_Expanded_Name
2925 Pref := Prefix (Pack_Name);
2926 while Nkind (Pref) = N_Expanded_Name loop
2927 Pref := Prefix (Pref);
2930 if Entity (Pref) = Standard_Standard then
2932 ("predefined package Standard cannot appear"
2933 & " in a context clause", Pref);
2941 -- Loop through package names to mark all entities as potentially
2944 Pack_Name := First (Names (N));
2945 while Present (Pack_Name) loop
2946 if Is_Entity_Name (Pack_Name) then
2947 Pack := Entity (Pack_Name);
2949 if Ekind (Pack) /= E_Package
2950 and then Etype (Pack) /= Any_Type
2952 if Ekind (Pack) = E_Generic_Package then
2953 Error_Msg_N -- CODEFIX
2954 ("a generic package is not allowed in a use clause",
2957 Error_Msg_N ("& is not a usable package", Pack_Name);
2961 if Nkind (Parent (N)) = N_Compilation_Unit then
2962 Check_In_Previous_With_Clause (N, Pack_Name);
2965 if Applicable_Use (Pack_Name) then
2966 Use_One_Package (Pack, N);
2970 -- Report error because name denotes something other than a package
2973 Error_Msg_N ("& is not a package", Pack_Name);
2978 end Analyze_Use_Package;
2980 ----------------------
2981 -- Analyze_Use_Type --
2982 ----------------------
2984 procedure Analyze_Use_Type (N : Node_Id) is
2989 Set_Hidden_By_Use_Clause (N, No_Elist);
2991 -- Chain clause to list of use clauses in current scope
2993 if Nkind (Parent (N)) /= N_Compilation_Unit then
2994 Chain_Use_Clause (N);
2997 -- If the Used_Operations list is already initialized, the clause has
2998 -- been analyzed previously, and it is begin reinstalled, for example
2999 -- when the clause appears in a package spec and we are compiling the
3000 -- corresponding package body. In that case, make the entities on the
3001 -- existing list use_visible, and mark the corresponding types In_Use.
3003 if Present (Used_Operations (N)) then
3009 Mark := First (Subtype_Marks (N));
3010 while Present (Mark) loop
3011 Use_One_Type (Mark, Installed => True);
3015 Elmt := First_Elmt (Used_Operations (N));
3016 while Present (Elmt) loop
3017 Set_Is_Potentially_Use_Visible (Node (Elmt));
3025 -- Otherwise, create new list and attach to it the operations that
3026 -- are made use-visible by the clause.
3028 Set_Used_Operations (N, New_Elmt_List);
3029 Id := First (Subtype_Marks (N));
3030 while Present (Id) loop
3034 if E /= Any_Type then
3037 if Nkind (Parent (N)) = N_Compilation_Unit then
3038 if Nkind (Id) = N_Identifier then
3039 Error_Msg_N ("type is not directly visible", Id);
3041 elsif Is_Child_Unit (Scope (E))
3042 and then Scope (E) /= System_Aux_Id
3044 Check_In_Previous_With_Clause (N, Prefix (Id));
3049 -- If the use_type_clause appears in a compilation unit context,
3050 -- check whether it comes from a unit that may appear in a
3051 -- limited_with_clause, for a better error message.
3053 if Nkind (Parent (N)) = N_Compilation_Unit
3054 and then Nkind (Id) /= N_Identifier
3060 function Mentioned (Nam : Node_Id) return Boolean;
3061 -- Check whether the prefix of expanded name for the type
3062 -- appears in the prefix of some limited_with_clause.
3068 function Mentioned (Nam : Node_Id) return Boolean is
3070 return Nkind (Name (Item)) = N_Selected_Component
3072 Chars (Prefix (Name (Item))) = Chars (Nam);
3076 Pref := Prefix (Id);
3077 Item := First (Context_Items (Parent (N)));
3079 while Present (Item) and then Item /= N loop
3080 if Nkind (Item) = N_With_Clause
3081 and then Limited_Present (Item)
3082 and then Mentioned (Pref)
3085 (Get_Msg_Id, "premature usage of incomplete type");
3096 end Analyze_Use_Type;
3098 --------------------
3099 -- Applicable_Use --
3100 --------------------
3102 function Applicable_Use (Pack_Name : Node_Id) return Boolean is
3103 Pack : constant Entity_Id := Entity (Pack_Name);
3106 if In_Open_Scopes (Pack) then
3107 if Warn_On_Redundant_Constructs
3108 and then Pack = Current_Scope
3110 Error_Msg_NE -- CODEFIX
3111 ("& is already use-visible within itself?", Pack_Name, Pack);
3116 elsif In_Use (Pack) then
3117 Note_Redundant_Use (Pack_Name);
3120 elsif Present (Renamed_Object (Pack))
3121 and then In_Use (Renamed_Object (Pack))
3123 Note_Redundant_Use (Pack_Name);
3131 ------------------------
3132 -- Attribute_Renaming --
3133 ------------------------
3135 procedure Attribute_Renaming (N : Node_Id) is
3136 Loc : constant Source_Ptr := Sloc (N);
3137 Nam : constant Node_Id := Name (N);
3138 Spec : constant Node_Id := Specification (N);
3139 New_S : constant Entity_Id := Defining_Unit_Name (Spec);
3140 Aname : constant Name_Id := Attribute_Name (Nam);
3142 Form_Num : Nat := 0;
3143 Expr_List : List_Id := No_List;
3145 Attr_Node : Node_Id;
3146 Body_Node : Node_Id;
3147 Param_Spec : Node_Id;
3150 Generate_Definition (New_S);
3152 -- This procedure is called in the context of subprogram renaming, and
3153 -- thus the attribute must be one that is a subprogram. All of those
3154 -- have at least one formal parameter, with the singular exception of
3155 -- AST_Entry (which is a real oddity, it is odd that this can be renamed
3158 if not Is_Non_Empty_List (Parameter_Specifications (Spec)) then
3159 if Aname /= Name_AST_Entry then
3161 ("subprogram renaming an attribute must have formals", N);
3166 Param_Spec := First (Parameter_Specifications (Spec));
3167 while Present (Param_Spec) loop
3168 Form_Num := Form_Num + 1;
3170 if Nkind (Parameter_Type (Param_Spec)) /= N_Access_Definition then
3171 Find_Type (Parameter_Type (Param_Spec));
3173 -- The profile of the new entity denotes the base type (s) of
3174 -- the types given in the specification. For access parameters
3175 -- there are no subtypes involved.
3177 Rewrite (Parameter_Type (Param_Spec),
3179 (Base_Type (Entity (Parameter_Type (Param_Spec))), Loc));
3182 if No (Expr_List) then
3183 Expr_List := New_List;
3186 Append_To (Expr_List,
3187 Make_Identifier (Loc,
3188 Chars => Chars (Defining_Identifier (Param_Spec))));
3190 -- The expressions in the attribute reference are not freeze
3191 -- points. Neither is the attribute as a whole, see below.
3193 Set_Must_Not_Freeze (Last (Expr_List));
3198 -- Immediate error if too many formals. Other mismatches in number or
3199 -- types of parameters are detected when we analyze the body of the
3200 -- subprogram that we construct.
3202 if Form_Num > 2 then
3203 Error_Msg_N ("too many formals for attribute", N);
3205 -- Error if the attribute reference has expressions that look like
3206 -- formal parameters.
3208 elsif Present (Expressions (Nam)) then
3209 Error_Msg_N ("illegal expressions in attribute reference", Nam);
3212 Aname = Name_Compose or else
3213 Aname = Name_Exponent or else
3214 Aname = Name_Leading_Part or else
3215 Aname = Name_Pos or else
3216 Aname = Name_Round or else
3217 Aname = Name_Scaling or else
3220 if Nkind (N) = N_Subprogram_Renaming_Declaration
3221 and then Present (Corresponding_Formal_Spec (N))
3224 ("generic actual cannot be attribute involving universal type",
3228 ("attribute involving a universal type cannot be renamed",
3233 -- AST_Entry is an odd case. It doesn't really make much sense to allow
3234 -- it to be renamed, but that's the DEC rule, so we have to do it right.
3235 -- The point is that the AST_Entry call should be made now, and what the
3236 -- function will return is the returned value.
3238 -- Note that there is no Expr_List in this case anyway
3240 if Aname = Name_AST_Entry then
3242 Ent : constant Entity_Id := Make_Temporary (Loc, 'R', Nam);
3247 Make_Object_Declaration (Loc,
3248 Defining_Identifier => Ent,
3249 Object_Definition =>
3250 New_Occurrence_Of (RTE (RE_AST_Handler), Loc),
3252 Constant_Present => True);
3254 Set_Assignment_OK (Decl, True);
3255 Insert_Action (N, Decl);
3256 Attr_Node := Make_Identifier (Loc, Chars (Ent));
3259 -- For all other attributes, we rewrite the attribute node to have
3260 -- a list of expressions corresponding to the subprogram formals.
3261 -- A renaming declaration is not a freeze point, and the analysis of
3262 -- the attribute reference should not freeze the type of the prefix.
3266 Make_Attribute_Reference (Loc,
3267 Prefix => Prefix (Nam),
3268 Attribute_Name => Aname,
3269 Expressions => Expr_List);
3271 Set_Must_Not_Freeze (Attr_Node);
3272 Set_Must_Not_Freeze (Prefix (Nam));
3275 -- Case of renaming a function
3277 if Nkind (Spec) = N_Function_Specification then
3278 if Is_Procedure_Attribute_Name (Aname) then
3279 Error_Msg_N ("attribute can only be renamed as procedure", Nam);
3283 Find_Type (Result_Definition (Spec));
3284 Rewrite (Result_Definition (Spec),
3286 Base_Type (Entity (Result_Definition (Spec))), Loc));
3289 Make_Subprogram_Body (Loc,
3290 Specification => Spec,
3291 Declarations => New_List,
3292 Handled_Statement_Sequence =>
3293 Make_Handled_Sequence_Of_Statements (Loc,
3294 Statements => New_List (
3295 Make_Simple_Return_Statement (Loc,
3296 Expression => Attr_Node))));
3298 -- Case of renaming a procedure
3301 if not Is_Procedure_Attribute_Name (Aname) then
3302 Error_Msg_N ("attribute can only be renamed as function", Nam);
3307 Make_Subprogram_Body (Loc,
3308 Specification => Spec,
3309 Declarations => New_List,
3310 Handled_Statement_Sequence =>
3311 Make_Handled_Sequence_Of_Statements (Loc,
3312 Statements => New_List (Attr_Node)));
3315 -- In case of tagged types we add the body of the generated function to
3316 -- the freezing actions of the type (because in the general case such
3317 -- type is still not frozen). We exclude from this processing generic
3318 -- formal subprograms found in instantiations and AST_Entry renamings.
3320 -- We must exclude VM targets and restricted run-time libraries because
3321 -- entity AST_Handler is defined in package System.Aux_Dec which is not
3322 -- available in those platforms. Note that we cannot use the function
3323 -- Restricted_Profile (instead of Configurable_Run_Time_Mode) because
3324 -- the ZFP run-time library is not defined as a profile, and we do not
3325 -- want to deal with AST_Handler in ZFP mode.
3327 if VM_Target = No_VM
3328 and then not Configurable_Run_Time_Mode
3329 and then not Present (Corresponding_Formal_Spec (N))
3330 and then Etype (Nam) /= RTE (RE_AST_Handler)
3333 P : constant Entity_Id := Prefix (Nam);
3338 if Is_Tagged_Type (Etype (P)) then
3339 Ensure_Freeze_Node (Etype (P));
3340 Append_Freeze_Action (Etype (P), Body_Node);
3342 Rewrite (N, Body_Node);
3344 Set_Etype (New_S, Base_Type (Etype (New_S)));
3348 -- Generic formal subprograms or AST_Handler renaming
3351 Rewrite (N, Body_Node);
3353 Set_Etype (New_S, Base_Type (Etype (New_S)));
3356 if Is_Compilation_Unit (New_S) then
3358 ("a library unit can only rename another library unit", N);
3361 -- We suppress elaboration warnings for the resulting entity, since
3362 -- clearly they are not needed, and more particularly, in the case
3363 -- of a generic formal subprogram, the resulting entity can appear
3364 -- after the instantiation itself, and thus look like a bogus case
3365 -- of access before elaboration.
3367 Set_Suppress_Elaboration_Warnings (New_S);
3369 end Attribute_Renaming;
3371 ----------------------
3372 -- Chain_Use_Clause --
3373 ----------------------
3375 procedure Chain_Use_Clause (N : Node_Id) is
3377 Level : Int := Scope_Stack.Last;
3380 if not Is_Compilation_Unit (Current_Scope)
3381 or else not Is_Child_Unit (Current_Scope)
3383 null; -- Common case
3385 elsif Defining_Entity (Parent (N)) = Current_Scope then
3386 null; -- Common case for compilation unit
3389 -- If declaration appears in some other scope, it must be in some
3390 -- parent unit when compiling a child.
3392 Pack := Defining_Entity (Parent (N));
3393 if not In_Open_Scopes (Pack) then
3394 null; -- default as well
3397 -- Find entry for parent unit in scope stack
3399 while Scope_Stack.Table (Level).Entity /= Pack loop
3405 Set_Next_Use_Clause (N,
3406 Scope_Stack.Table (Level).First_Use_Clause);
3407 Scope_Stack.Table (Level).First_Use_Clause := N;
3408 end Chain_Use_Clause;
3410 ---------------------------
3411 -- Check_Frozen_Renaming --
3412 ---------------------------
3414 procedure Check_Frozen_Renaming (N : Node_Id; Subp : Entity_Id) is
3420 and then not Has_Completion (Subp)
3424 (Parent (Declaration_Node (Subp)), Defining_Entity (N));
3426 if Is_Entity_Name (Name (N)) then
3427 Old_S := Entity (Name (N));
3429 if not Is_Frozen (Old_S)
3430 and then Operating_Mode /= Check_Semantics
3432 Append_Freeze_Action (Old_S, B_Node);
3434 Insert_After (N, B_Node);
3438 if Is_Intrinsic_Subprogram (Old_S)
3439 and then not In_Instance
3442 ("subprogram used in renaming_as_body cannot be intrinsic",
3447 Insert_After (N, B_Node);
3451 end Check_Frozen_Renaming;
3453 -------------------------------
3454 -- Set_Entity_Or_Discriminal --
3455 -------------------------------
3457 procedure Set_Entity_Or_Discriminal (N : Node_Id; E : Entity_Id) is
3461 -- If the entity is not a discriminant, or else expansion is disabled,
3462 -- simply set the entity.
3464 if not In_Spec_Expression
3465 or else Ekind (E) /= E_Discriminant
3466 or else Inside_A_Generic
3468 Set_Entity_With_Style_Check (N, E);
3470 -- The replacement of a discriminant by the corresponding discriminal
3471 -- is not done for a task discriminant that appears in a default
3472 -- expression of an entry parameter. See Exp_Ch2.Expand_Discriminant
3473 -- for details on their handling.
3475 elsif Is_Concurrent_Type (Scope (E)) then
3479 and then not Nkind_In (P, N_Parameter_Specification,
3480 N_Component_Declaration)
3486 and then Nkind (P) = N_Parameter_Specification
3491 Set_Entity (N, Discriminal (E));
3494 -- Otherwise, this is a discriminant in a context in which
3495 -- it is a reference to the corresponding parameter of the
3496 -- init proc for the enclosing type.
3499 Set_Entity (N, Discriminal (E));
3501 end Set_Entity_Or_Discriminal;
3503 -----------------------------------
3504 -- Check_In_Previous_With_Clause --
3505 -----------------------------------
3507 procedure Check_In_Previous_With_Clause
3511 Pack : constant Entity_Id := Entity (Original_Node (Nam));
3516 Item := First (Context_Items (Parent (N)));
3518 while Present (Item)
3521 if Nkind (Item) = N_With_Clause
3523 -- Protect the frontend against previous critical errors
3525 and then Nkind (Name (Item)) /= N_Selected_Component
3526 and then Entity (Name (Item)) = Pack
3530 -- Find root library unit in with_clause
3532 while Nkind (Par) = N_Expanded_Name loop
3533 Par := Prefix (Par);
3536 if Is_Child_Unit (Entity (Original_Node (Par))) then
3537 Error_Msg_NE ("& is not directly visible", Par, Entity (Par));
3546 -- On exit, package is not mentioned in a previous with_clause.
3547 -- Check if its prefix is.
3549 if Nkind (Nam) = N_Expanded_Name then
3550 Check_In_Previous_With_Clause (N, Prefix (Nam));
3552 elsif Pack /= Any_Id then
3553 Error_Msg_NE ("& is not visible", Nam, Pack);
3555 end Check_In_Previous_With_Clause;
3557 ---------------------------------
3558 -- Check_Library_Unit_Renaming --
3559 ---------------------------------
3561 procedure Check_Library_Unit_Renaming (N : Node_Id; Old_E : Entity_Id) is
3565 if Nkind (Parent (N)) /= N_Compilation_Unit then
3568 -- Check for library unit. Note that we used to check for the scope
3569 -- being Standard here, but that was wrong for Standard itself.
3571 elsif not Is_Compilation_Unit (Old_E)
3572 and then not Is_Child_Unit (Old_E)
3574 Error_Msg_N ("renamed unit must be a library unit", Name (N));
3576 -- Entities defined in Standard (operators and boolean literals) cannot
3577 -- be renamed as library units.
3579 elsif Scope (Old_E) = Standard_Standard
3580 and then Sloc (Old_E) = Standard_Location
3582 Error_Msg_N ("renamed unit must be a library unit", Name (N));
3584 elsif Present (Parent_Spec (N))
3585 and then Nkind (Unit (Parent_Spec (N))) = N_Generic_Package_Declaration
3586 and then not Is_Child_Unit (Old_E)
3589 ("renamed unit must be a child unit of generic parent", Name (N));
3591 elsif Nkind (N) in N_Generic_Renaming_Declaration
3592 and then Nkind (Name (N)) = N_Expanded_Name
3593 and then Is_Generic_Instance (Entity (Prefix (Name (N))))
3594 and then Is_Generic_Unit (Old_E)
3597 ("renamed generic unit must be a library unit", Name (N));
3599 elsif Is_Package_Or_Generic_Package (Old_E) then
3601 -- Inherit categorization flags
3603 New_E := Defining_Entity (N);
3604 Set_Is_Pure (New_E, Is_Pure (Old_E));
3605 Set_Is_Preelaborated (New_E, Is_Preelaborated (Old_E));
3606 Set_Is_Remote_Call_Interface (New_E,
3607 Is_Remote_Call_Interface (Old_E));
3608 Set_Is_Remote_Types (New_E, Is_Remote_Types (Old_E));
3609 Set_Is_Shared_Passive (New_E, Is_Shared_Passive (Old_E));
3611 end Check_Library_Unit_Renaming;
3617 procedure End_Scope is
3623 Id := First_Entity (Current_Scope);
3624 while Present (Id) loop
3625 -- An entity in the current scope is not necessarily the first one
3626 -- on its homonym chain. Find its predecessor if any,
3627 -- If it is an internal entity, it will not be in the visibility
3628 -- chain altogether, and there is nothing to unchain.
3630 if Id /= Current_Entity (Id) then
3631 Prev := Current_Entity (Id);
3632 while Present (Prev)
3633 and then Present (Homonym (Prev))
3634 and then Homonym (Prev) /= Id
3636 Prev := Homonym (Prev);
3639 -- Skip to end of loop if Id is not in the visibility chain
3641 if No (Prev) or else Homonym (Prev) /= Id then
3649 Set_Is_Immediately_Visible (Id, False);
3651 Outer := Homonym (Id);
3652 while Present (Outer) and then Scope (Outer) = Current_Scope loop
3653 Outer := Homonym (Outer);
3656 -- Reset homonym link of other entities, but do not modify link
3657 -- between entities in current scope, so that the back-end can have
3658 -- a proper count of local overloadings.
3661 Set_Name_Entity_Id (Chars (Id), Outer);
3663 elsif Scope (Prev) /= Scope (Id) then
3664 Set_Homonym (Prev, Outer);
3671 -- If the scope generated freeze actions, place them before the
3672 -- current declaration and analyze them. Type declarations and
3673 -- the bodies of initialization procedures can generate such nodes.
3674 -- We follow the parent chain until we reach a list node, which is
3675 -- the enclosing list of declarations. If the list appears within
3676 -- a protected definition, move freeze nodes outside the protected
3680 (Scope_Stack.Table (Scope_Stack.Last).Pending_Freeze_Actions)
3684 L : constant List_Id := Scope_Stack.Table
3685 (Scope_Stack.Last).Pending_Freeze_Actions;
3688 if Is_Itype (Current_Scope) then
3689 Decl := Associated_Node_For_Itype (Current_Scope);
3691 Decl := Parent (Current_Scope);
3696 while not (Is_List_Member (Decl))
3697 or else Nkind_In (Parent (Decl), N_Protected_Definition,
3700 Decl := Parent (Decl);
3703 Insert_List_Before_And_Analyze (Decl, L);
3712 ---------------------
3713 -- End_Use_Clauses --
3714 ---------------------
3716 procedure End_Use_Clauses (Clause : Node_Id) is
3720 -- Remove Use_Type clauses first, because they affect the
3721 -- visibility of operators in subsequent used packages.
3724 while Present (U) loop
3725 if Nkind (U) = N_Use_Type_Clause then
3729 Next_Use_Clause (U);
3733 while Present (U) loop
3734 if Nkind (U) = N_Use_Package_Clause then
3735 End_Use_Package (U);
3738 Next_Use_Clause (U);
3740 end End_Use_Clauses;
3742 ---------------------
3743 -- End_Use_Package --
3744 ---------------------
3746 procedure End_Use_Package (N : Node_Id) is
3747 Pack_Name : Node_Id;
3752 function Is_Primitive_Operator_In_Use
3754 F : Entity_Id) return Boolean;
3755 -- Check whether Op is a primitive operator of a use-visible type
3757 ----------------------------------
3758 -- Is_Primitive_Operator_In_Use --
3759 ----------------------------------
3761 function Is_Primitive_Operator_In_Use
3763 F : Entity_Id) return Boolean
3765 T : constant Entity_Id := Base_Type (Etype (F));
3767 return In_Use (T) and then Scope (T) = Scope (Op);
3768 end Is_Primitive_Operator_In_Use;
3770 -- Start of processing for End_Use_Package
3773 Pack_Name := First (Names (N));
3774 while Present (Pack_Name) loop
3776 -- Test that Pack_Name actually denotes a package before processing
3778 if Is_Entity_Name (Pack_Name)
3779 and then Ekind (Entity (Pack_Name)) = E_Package
3781 Pack := Entity (Pack_Name);
3783 if In_Open_Scopes (Pack) then
3786 elsif not Redundant_Use (Pack_Name) then
3787 Set_In_Use (Pack, False);
3788 Set_Current_Use_Clause (Pack, Empty);
3790 Id := First_Entity (Pack);
3791 while Present (Id) loop
3793 -- Preserve use-visibility of operators that are primitive
3794 -- operators of a type that is use-visible through an active
3797 if Nkind (Id) = N_Defining_Operator_Symbol
3799 (Is_Primitive_Operator_In_Use
3800 (Id, First_Formal (Id))
3802 (Present (Next_Formal (First_Formal (Id)))
3804 Is_Primitive_Operator_In_Use
3805 (Id, Next_Formal (First_Formal (Id)))))
3810 Set_Is_Potentially_Use_Visible (Id, False);
3813 if Is_Private_Type (Id)
3814 and then Present (Full_View (Id))
3816 Set_Is_Potentially_Use_Visible (Full_View (Id), False);
3822 if Present (Renamed_Object (Pack)) then
3823 Set_In_Use (Renamed_Object (Pack), False);
3824 Set_Current_Use_Clause (Renamed_Object (Pack), Empty);
3827 if Chars (Pack) = Name_System
3828 and then Scope (Pack) = Standard_Standard
3829 and then Present_System_Aux
3831 Id := First_Entity (System_Aux_Id);
3832 while Present (Id) loop
3833 Set_Is_Potentially_Use_Visible (Id, False);
3835 if Is_Private_Type (Id)
3836 and then Present (Full_View (Id))
3838 Set_Is_Potentially_Use_Visible (Full_View (Id), False);
3844 Set_In_Use (System_Aux_Id, False);
3848 Set_Redundant_Use (Pack_Name, False);
3855 if Present (Hidden_By_Use_Clause (N)) then
3856 Elmt := First_Elmt (Hidden_By_Use_Clause (N));
3857 while Present (Elmt) loop
3859 E : constant Entity_Id := Node (Elmt);
3862 -- Reset either Use_Visibility or Direct_Visibility, depending
3863 -- on how the entity was hidden by the use clause.
3865 if In_Use (Scope (E))
3866 and then Used_As_Generic_Actual (Scope (E))
3868 Set_Is_Potentially_Use_Visible (Node (Elmt));
3870 Set_Is_Immediately_Visible (Node (Elmt));
3877 Set_Hidden_By_Use_Clause (N, No_Elist);
3879 end End_Use_Package;
3885 procedure End_Use_Type (N : Node_Id) is
3890 -- Start of processing for End_Use_Type
3893 Id := First (Subtype_Marks (N));
3894 while Present (Id) loop
3896 -- A call to Rtsfind may occur while analyzing a use_type clause,
3897 -- in which case the type marks are not resolved yet, and there is
3898 -- nothing to remove.
3900 if not Is_Entity_Name (Id) or else No (Entity (Id)) then
3906 if T = Any_Type or else From_With_Type (T) then
3909 -- Note that the use_type clause may mention a subtype of the type
3910 -- whose primitive operations have been made visible. Here as
3911 -- elsewhere, it is the base type that matters for visibility.
3913 elsif In_Open_Scopes (Scope (Base_Type (T))) then
3916 elsif not Redundant_Use (Id) then
3917 Set_In_Use (T, False);
3918 Set_In_Use (Base_Type (T), False);
3919 Set_Current_Use_Clause (T, Empty);
3920 Set_Current_Use_Clause (Base_Type (T), Empty);
3927 if Is_Empty_Elmt_List (Used_Operations (N)) then
3931 Elmt := First_Elmt (Used_Operations (N));
3932 while Present (Elmt) loop
3933 Set_Is_Potentially_Use_Visible (Node (Elmt), False);
3939 ----------------------
3940 -- Find_Direct_Name --
3941 ----------------------
3943 procedure Find_Direct_Name (N : Node_Id) is
3948 Inst : Entity_Id := Empty;
3949 -- Enclosing instance, if any
3951 Homonyms : Entity_Id;
3952 -- Saves start of homonym chain
3954 Nvis_Entity : Boolean;
3955 -- Set True to indicate that there is at least one entity on the homonym
3956 -- chain which, while not visible, is visible enough from the user point
3957 -- of view to warrant an error message of "not visible" rather than
3960 Nvis_Is_Private_Subprg : Boolean := False;
3961 -- Ada 2005 (AI-262): Set True to indicate that a form of Beaujolais
3962 -- effect concerning library subprograms has been detected. Used to
3963 -- generate the precise error message.
3965 function From_Actual_Package (E : Entity_Id) return Boolean;
3966 -- Returns true if the entity is declared in a package that is
3967 -- an actual for a formal package of the current instance. Such an
3968 -- entity requires special handling because it may be use-visible
3969 -- but hides directly visible entities defined outside the instance.
3971 function Is_Actual_Parameter return Boolean;
3972 -- This function checks if the node N is an identifier that is an actual
3973 -- parameter of a procedure call. If so it returns True, otherwise it
3974 -- return False. The reason for this check is that at this stage we do
3975 -- not know what procedure is being called if the procedure might be
3976 -- overloaded, so it is premature to go setting referenced flags or
3977 -- making calls to Generate_Reference. We will wait till Resolve_Actuals
3978 -- for that processing
3980 function Known_But_Invisible (E : Entity_Id) return Boolean;
3981 -- This function determines whether the entity E (which is not
3982 -- visible) can reasonably be considered to be known to the writer
3983 -- of the reference. This is a heuristic test, used only for the
3984 -- purposes of figuring out whether we prefer to complain that an
3985 -- entity is undefined or invisible (and identify the declaration
3986 -- of the invisible entity in the latter case). The point here is
3987 -- that we don't want to complain that something is invisible and
3988 -- then point to something entirely mysterious to the writer.
3990 procedure Nvis_Messages;
3991 -- Called if there are no visible entries for N, but there is at least
3992 -- one non-directly visible, or hidden declaration. This procedure
3993 -- outputs an appropriate set of error messages.
3995 procedure Undefined (Nvis : Boolean);
3996 -- This function is called if the current node has no corresponding
3997 -- visible entity or entities. The value set in Msg indicates whether
3998 -- an error message was generated (multiple error messages for the
3999 -- same variable are generally suppressed, see body for details).
4000 -- Msg is True if an error message was generated, False if not. This
4001 -- value is used by the caller to determine whether or not to output
4002 -- additional messages where appropriate. The parameter is set False
4003 -- to get the message "X is undefined", and True to get the message
4004 -- "X is not visible".
4006 -------------------------
4007 -- From_Actual_Package --
4008 -------------------------
4010 function From_Actual_Package (E : Entity_Id) return Boolean is
4011 Scop : constant Entity_Id := Scope (E);
4015 if not In_Instance then
4018 Inst := Current_Scope;
4019 while Present (Inst)
4020 and then Ekind (Inst) /= E_Package
4021 and then not Is_Generic_Instance (Inst)
4023 Inst := Scope (Inst);
4030 Act := First_Entity (Inst);
4031 while Present (Act) loop
4032 if Ekind (Act) = E_Package then
4034 -- Check for end of actuals list
4036 if Renamed_Object (Act) = Inst then
4039 elsif Present (Associated_Formal_Package (Act))
4040 and then Renamed_Object (Act) = Scop
4042 -- Entity comes from (instance of) formal package
4057 end From_Actual_Package;
4059 -------------------------
4060 -- Is_Actual_Parameter --
4061 -------------------------
4063 function Is_Actual_Parameter return Boolean is
4066 Nkind (N) = N_Identifier
4068 (Nkind (Parent (N)) = N_Procedure_Call_Statement
4070 (Nkind (Parent (N)) = N_Parameter_Association
4071 and then N = Explicit_Actual_Parameter (Parent (N))
4072 and then Nkind (Parent (Parent (N))) =
4073 N_Procedure_Call_Statement));
4074 end Is_Actual_Parameter;
4076 -------------------------
4077 -- Known_But_Invisible --
4078 -------------------------
4080 function Known_But_Invisible (E : Entity_Id) return Boolean is
4081 Fname : File_Name_Type;
4084 -- Entities in Standard are always considered to be known
4086 if Sloc (E) <= Standard_Location then
4089 -- An entity that does not come from source is always considered
4090 -- to be unknown, since it is an artifact of code expansion.
4092 elsif not Comes_From_Source (E) then
4095 -- In gnat internal mode, we consider all entities known
4097 elsif GNAT_Mode then
4101 -- Here we have an entity that is not from package Standard, and
4102 -- which comes from Source. See if it comes from an internal file.
4104 Fname := Unit_File_Name (Get_Source_Unit (E));
4106 -- Case of from internal file
4108 if Is_Internal_File_Name (Fname) then
4110 -- Private part entities in internal files are never considered
4111 -- to be known to the writer of normal application code.
4113 if Is_Hidden (E) then
4117 -- Entities from System packages other than System and
4118 -- System.Storage_Elements are not considered to be known.
4119 -- System.Auxxxx files are also considered known to the user.
4121 -- Should refine this at some point to generally distinguish
4122 -- between known and unknown internal files ???
4124 Get_Name_String (Fname);
4129 Name_Buffer (1 .. 2) /= "s-"
4131 Name_Buffer (3 .. 8) = "stoele"
4133 Name_Buffer (3 .. 5) = "aux";
4135 -- If not an internal file, then entity is definitely known,
4136 -- even if it is in a private part (the message generated will
4137 -- note that it is in a private part)
4142 end Known_But_Invisible;
4148 procedure Nvis_Messages is
4149 Comp_Unit : Node_Id;
4151 Found : Boolean := False;
4152 Hidden : Boolean := False;
4156 -- Ada 2005 (AI-262): Generate a precise error concerning the
4157 -- Beaujolais effect that was previously detected
4159 if Nvis_Is_Private_Subprg then
4161 pragma Assert (Nkind (E2) = N_Defining_Identifier
4162 and then Ekind (E2) = E_Function
4163 and then Scope (E2) = Standard_Standard
4164 and then Has_Private_With (E2));
4166 -- Find the sloc corresponding to the private with'ed unit
4168 Comp_Unit := Cunit (Current_Sem_Unit);
4169 Error_Msg_Sloc := No_Location;
4171 Item := First (Context_Items (Comp_Unit));
4172 while Present (Item) loop
4173 if Nkind (Item) = N_With_Clause
4174 and then Private_Present (Item)
4175 and then Entity (Name (Item)) = E2
4177 Error_Msg_Sloc := Sloc (Item);
4184 pragma Assert (Error_Msg_Sloc /= No_Location);
4186 Error_Msg_N ("(Ada 2005): hidden by private with clause #", N);
4190 Undefined (Nvis => True);
4194 -- First loop does hidden declarations
4197 while Present (Ent) loop
4198 if Is_Potentially_Use_Visible (Ent) then
4200 Error_Msg_N -- CODEFIX
4201 ("multiple use clauses cause hiding!", N);
4205 Error_Msg_Sloc := Sloc (Ent);
4206 Error_Msg_N -- CODEFIX
4207 ("hidden declaration#!", N);
4210 Ent := Homonym (Ent);
4213 -- If we found hidden declarations, then that's enough, don't
4214 -- bother looking for non-visible declarations as well.
4220 -- Second loop does non-directly visible declarations
4223 while Present (Ent) loop
4224 if not Is_Potentially_Use_Visible (Ent) then
4226 -- Do not bother the user with unknown entities
4228 if not Known_But_Invisible (Ent) then
4232 Error_Msg_Sloc := Sloc (Ent);
4234 -- Output message noting that there is a non-visible
4235 -- declaration, distinguishing the private part case.
4237 if Is_Hidden (Ent) then
4238 Error_Msg_N ("non-visible (private) declaration#!", N);
4240 -- If the entity is declared in a generic package, it
4241 -- cannot be visible, so there is no point in adding it
4242 -- to the list of candidates if another homograph from a
4243 -- non-generic package has been seen.
4245 elsif Ekind (Scope (Ent)) = E_Generic_Package
4251 Error_Msg_N -- CODEFIX
4252 ("non-visible declaration#!", N);
4254 if Ekind (Scope (Ent)) /= E_Generic_Package then
4258 if Is_Compilation_Unit (Ent)
4260 Nkind (Parent (Parent (N))) = N_Use_Package_Clause
4262 Error_Msg_Qual_Level := 99;
4263 Error_Msg_NE -- CODEFIX
4264 ("\\missing `WITH &;`", N, Ent);
4265 Error_Msg_Qual_Level := 0;
4268 if Ekind (Ent) = E_Discriminant
4269 and then Present (Corresponding_Discriminant (Ent))
4270 and then Scope (Corresponding_Discriminant (Ent)) =
4274 ("inherited discriminant not allowed here" &
4275 " (RM 3.8 (12), 3.8.1 (6))!", N);
4279 -- Set entity and its containing package as referenced. We
4280 -- can't be sure of this, but this seems a better choice
4281 -- to avoid unused entity messages.
4283 if Comes_From_Source (Ent) then
4284 Set_Referenced (Ent);
4285 Set_Referenced (Cunit_Entity (Get_Source_Unit (Ent)));
4290 Ent := Homonym (Ent);
4299 procedure Undefined (Nvis : Boolean) is
4300 Emsg : Error_Msg_Id;
4303 -- We should never find an undefined internal name. If we do, then
4304 -- see if we have previous errors. If so, ignore on the grounds that
4305 -- it is probably a cascaded message (e.g. a block label from a badly
4306 -- formed block). If no previous errors, then we have a real internal
4307 -- error of some kind so raise an exception.
4309 if Is_Internal_Name (Chars (N)) then
4310 if Total_Errors_Detected /= 0 then
4313 raise Program_Error;
4317 -- A very specialized error check, if the undefined variable is
4318 -- a case tag, and the case type is an enumeration type, check
4319 -- for a possible misspelling, and if so, modify the identifier
4321 -- Named aggregate should also be handled similarly ???
4323 if Nkind (N) = N_Identifier
4324 and then Nkind (Parent (N)) = N_Case_Statement_Alternative
4327 Case_Stm : constant Node_Id := Parent (Parent (N));
4328 Case_Typ : constant Entity_Id := Etype (Expression (Case_Stm));
4333 if Is_Enumeration_Type (Case_Typ)
4334 and then not Is_Standard_Character_Type (Case_Typ)
4336 Lit := First_Literal (Case_Typ);
4337 Get_Name_String (Chars (Lit));
4339 if Chars (Lit) /= Chars (N)
4340 and then Is_Bad_Spelling_Of (Chars (N), Chars (Lit)) then
4341 Error_Msg_Node_2 := Lit;
4342 Error_Msg_N -- CODEFIX
4343 ("& is undefined, assume misspelling of &", N);
4344 Rewrite (N, New_Occurrence_Of (Lit, Sloc (N)));
4348 Lit := Next_Literal (Lit);
4353 -- Normal processing
4355 Set_Entity (N, Any_Id);
4356 Set_Etype (N, Any_Type);
4358 -- We use the table Urefs to keep track of entities for which we
4359 -- have issued errors for undefined references. Multiple errors
4360 -- for a single name are normally suppressed, however we modify
4361 -- the error message to alert the programmer to this effect.
4363 for J in Urefs.First .. Urefs.Last loop
4364 if Chars (N) = Chars (Urefs.Table (J).Node) then
4365 if Urefs.Table (J).Err /= No_Error_Msg
4366 and then Sloc (N) /= Urefs.Table (J).Loc
4368 Error_Msg_Node_1 := Urefs.Table (J).Node;
4370 if Urefs.Table (J).Nvis then
4371 Change_Error_Text (Urefs.Table (J).Err,
4372 "& is not visible (more references follow)");
4374 Change_Error_Text (Urefs.Table (J).Err,
4375 "& is undefined (more references follow)");
4378 Urefs.Table (J).Err := No_Error_Msg;
4381 -- Although we will set Msg False, and thus suppress the
4382 -- message, we also set Error_Posted True, to avoid any
4383 -- cascaded messages resulting from the undefined reference.
4386 Set_Error_Posted (N, True);
4391 -- If entry not found, this is first undefined occurrence
4394 Error_Msg_N ("& is not visible!", N);
4398 Error_Msg_N ("& is undefined!", N);
4401 -- A very bizarre special check, if the undefined identifier
4402 -- is put or put_line, then add a special error message (since
4403 -- this is a very common error for beginners to make).
4405 if Chars (N) = Name_Put or else Chars (N) = Name_Put_Line then
4406 Error_Msg_N -- CODEFIX
4407 ("\\possible missing `WITH Ada.Text_'I'O; " &
4408 "USE Ada.Text_'I'O`!", N);
4410 -- Another special check if N is the prefix of a selected
4411 -- component which is a known unit, add message complaining
4412 -- about missing with for this unit.
4414 elsif Nkind (Parent (N)) = N_Selected_Component
4415 and then N = Prefix (Parent (N))
4416 and then Is_Known_Unit (Parent (N))
4418 Error_Msg_Node_2 := Selector_Name (Parent (N));
4419 Error_Msg_N -- CODEFIX
4420 ("\\missing `WITH &.&;`", Prefix (Parent (N)));
4423 -- Now check for possible misspellings
4427 Ematch : Entity_Id := Empty;
4429 Last_Name_Id : constant Name_Id :=
4430 Name_Id (Nat (First_Name_Id) +
4431 Name_Entries_Count - 1);
4434 for Nam in First_Name_Id .. Last_Name_Id loop
4435 E := Get_Name_Entity_Id (Nam);
4438 and then (Is_Immediately_Visible (E)
4440 Is_Potentially_Use_Visible (E))
4442 if Is_Bad_Spelling_Of (Chars (N), Nam) then
4449 if Present (Ematch) then
4450 Error_Msg_NE -- CODEFIX
4451 ("\possible misspelling of&", N, Ematch);
4456 -- Make entry in undefined references table unless the full errors
4457 -- switch is set, in which case by refraining from generating the
4458 -- table entry, we guarantee that we get an error message for every
4459 -- undefined reference.
4461 if not All_Errors_Mode then
4472 -- Start of processing for Find_Direct_Name
4475 -- If the entity pointer is already set, this is an internal node, or
4476 -- a node that is analyzed more than once, after a tree modification.
4477 -- In such a case there is no resolution to perform, just set the type.
4479 if Present (Entity (N)) then
4480 if Is_Type (Entity (N)) then
4481 Set_Etype (N, Entity (N));
4485 Entyp : constant Entity_Id := Etype (Entity (N));
4488 -- One special case here. If the Etype field is already set,
4489 -- and references the packed array type corresponding to the
4490 -- etype of the referenced entity, then leave it alone. This
4491 -- happens for trees generated from Exp_Pakd, where expressions
4492 -- can be deliberately "mis-typed" to the packed array type.
4494 if Is_Array_Type (Entyp)
4495 and then Is_Packed (Entyp)
4496 and then Present (Etype (N))
4497 and then Etype (N) = Packed_Array_Type (Entyp)
4501 -- If not that special case, then just reset the Etype
4504 Set_Etype (N, Etype (Entity (N)));
4512 -- Here if Entity pointer was not set, we need full visibility analysis
4513 -- First we generate debugging output if the debug E flag is set.
4515 if Debug_Flag_E then
4516 Write_Str ("Looking for ");
4517 Write_Name (Chars (N));
4521 Homonyms := Current_Entity (N);
4522 Nvis_Entity := False;
4525 while Present (E) loop
4527 -- If entity is immediately visible or potentially use visible, then
4528 -- process the entity and we are done.
4530 if Is_Immediately_Visible (E) then
4531 goto Immediately_Visible_Entity;
4533 elsif Is_Potentially_Use_Visible (E) then
4534 goto Potentially_Use_Visible_Entity;
4536 -- Note if a known but invisible entity encountered
4538 elsif Known_But_Invisible (E) then
4539 Nvis_Entity := True;
4542 -- Move to next entity in chain and continue search
4547 -- If no entries on homonym chain that were potentially visible,
4548 -- and no entities reasonably considered as non-visible, then
4549 -- we have a plain undefined reference, with no additional
4550 -- explanation required!
4552 if not Nvis_Entity then
4553 Undefined (Nvis => False);
4555 -- Otherwise there is at least one entry on the homonym chain that
4556 -- is reasonably considered as being known and non-visible.
4564 -- Processing for a potentially use visible entry found. We must search
4565 -- the rest of the homonym chain for two reasons. First, if there is a
4566 -- directly visible entry, then none of the potentially use-visible
4567 -- entities are directly visible (RM 8.4(10)). Second, we need to check
4568 -- for the case of multiple potentially use-visible entries hiding one
4569 -- another and as a result being non-directly visible (RM 8.4(11)).
4571 <<Potentially_Use_Visible_Entity>> declare
4572 Only_One_Visible : Boolean := True;
4573 All_Overloadable : Boolean := Is_Overloadable (E);
4577 while Present (E2) loop
4578 if Is_Immediately_Visible (E2) then
4580 -- If the use-visible entity comes from the actual for a
4581 -- formal package, it hides a directly visible entity from
4582 -- outside the instance.
4584 if From_Actual_Package (E)
4585 and then Scope_Depth (E2) < Scope_Depth (Inst)
4590 goto Immediately_Visible_Entity;
4593 elsif Is_Potentially_Use_Visible (E2) then
4594 Only_One_Visible := False;
4595 All_Overloadable := All_Overloadable and Is_Overloadable (E2);
4597 -- Ada 2005 (AI-262): Protect against a form of Beaujolais effect
4598 -- that can occur in private_with clauses. Example:
4601 -- private with B; package A is
4602 -- package C is function B return Integer;
4604 -- V1 : Integer := B;
4605 -- private function B return Integer;
4606 -- V2 : Integer := B;
4609 -- V1 resolves to A.B, but V2 resolves to library unit B
4611 elsif Ekind (E2) = E_Function
4612 and then Scope (E2) = Standard_Standard
4613 and then Has_Private_With (E2)
4615 Only_One_Visible := False;
4616 All_Overloadable := False;
4617 Nvis_Is_Private_Subprg := True;
4624 -- On falling through this loop, we have checked that there are no
4625 -- immediately visible entities. Only_One_Visible is set if exactly
4626 -- one potentially use visible entity exists. All_Overloadable is
4627 -- set if all the potentially use visible entities are overloadable.
4628 -- The condition for legality is that either there is one potentially
4629 -- use visible entity, or if there is more than one, then all of them
4630 -- are overloadable.
4632 if Only_One_Visible or All_Overloadable then
4635 -- If there is more than one potentially use-visible entity and at
4636 -- least one of them non-overloadable, we have an error (RM 8.4(11).
4637 -- Note that E points to the first such entity on the homonym list.
4638 -- Special case: if one of the entities is declared in an actual
4639 -- package, it was visible in the generic, and takes precedence over
4640 -- other entities that are potentially use-visible. Same if it is
4641 -- declared in a local instantiation of the current instance.
4646 -- Find current instance
4648 Inst := Current_Scope;
4649 while Present (Inst)
4650 and then Inst /= Standard_Standard
4652 if Is_Generic_Instance (Inst) then
4656 Inst := Scope (Inst);
4660 while Present (E2) loop
4661 if From_Actual_Package (E2)
4663 (Is_Generic_Instance (Scope (E2))
4664 and then Scope_Depth (Scope (E2)) > Scope_Depth (Inst))
4677 Is_Predefined_File_Name (Unit_File_Name (Current_Sem_Unit))
4679 -- A use-clause in the body of a system file creates conflict
4680 -- with some entity in a user scope, while rtsfind is active.
4681 -- Keep only the entity coming from another predefined unit.
4684 while Present (E2) loop
4685 if Is_Predefined_File_Name
4686 (Unit_File_Name (Get_Source_Unit (Sloc (E2))))
4695 -- Entity must exist because predefined unit is correct
4697 raise Program_Error;
4706 -- Come here with E set to the first immediately visible entity on
4707 -- the homonym chain. This is the one we want unless there is another
4708 -- immediately visible entity further on in the chain for an inner
4709 -- scope (RM 8.3(8)).
4711 <<Immediately_Visible_Entity>> declare
4716 -- Find scope level of initial entity. When compiling through
4717 -- Rtsfind, the previous context is not completely invisible, and
4718 -- an outer entity may appear on the chain, whose scope is below
4719 -- the entry for Standard that delimits the current scope stack.
4720 -- Indicate that the level for this spurious entry is outside of
4721 -- the current scope stack.
4723 Level := Scope_Stack.Last;
4725 Scop := Scope_Stack.Table (Level).Entity;
4726 exit when Scop = Scope (E);
4728 exit when Scop = Standard_Standard;
4731 -- Now search remainder of homonym chain for more inner entry
4732 -- If the entity is Standard itself, it has no scope, and we
4733 -- compare it with the stack entry directly.
4736 while Present (E2) loop
4737 if Is_Immediately_Visible (E2) then
4739 -- If a generic package contains a local declaration that
4740 -- has the same name as the generic, there may be a visibility
4741 -- conflict in an instance, where the local declaration must
4742 -- also hide the name of the corresponding package renaming.
4743 -- We check explicitly for a package declared by a renaming,
4744 -- whose renamed entity is an instance that is on the scope
4745 -- stack, and that contains a homonym in the same scope. Once
4746 -- we have found it, we know that the package renaming is not
4747 -- immediately visible, and that the identifier denotes the
4748 -- other entity (and its homonyms if overloaded).
4750 if Scope (E) = Scope (E2)
4751 and then Ekind (E) = E_Package
4752 and then Present (Renamed_Object (E))
4753 and then Is_Generic_Instance (Renamed_Object (E))
4754 and then In_Open_Scopes (Renamed_Object (E))
4755 and then Comes_From_Source (N)
4757 Set_Is_Immediately_Visible (E, False);
4761 for J in Level + 1 .. Scope_Stack.Last loop
4762 if Scope_Stack.Table (J).Entity = Scope (E2)
4763 or else Scope_Stack.Table (J).Entity = E2
4776 -- At the end of that loop, E is the innermost immediately
4777 -- visible entity, so we are all set.
4780 -- Come here with entity found, and stored in E
4784 -- Check violation of No_Wide_Characters restriction
4786 Check_Wide_Character_Restriction (E, N);
4788 -- When distribution features are available (Get_PCS_Name /=
4789 -- Name_No_DSA), a remote access-to-subprogram type is converted
4790 -- into a record type holding whatever information is needed to
4791 -- perform a remote call on an RCI subprogram. In that case we
4792 -- rewrite any occurrence of the RAS type into the equivalent record
4793 -- type here. 'Access attribute references and RAS dereferences are
4794 -- then implemented using specific TSSs. However when distribution is
4795 -- not available (case of Get_PCS_Name = Name_No_DSA), we bypass the
4796 -- generation of these TSSs, and we must keep the RAS type in its
4797 -- original access-to-subprogram form (since all calls through a
4798 -- value of such type will be local anyway in the absence of a PCS).
4800 if Comes_From_Source (N)
4801 and then Is_Remote_Access_To_Subprogram_Type (E)
4802 and then Expander_Active
4803 and then Get_PCS_Name /= Name_No_DSA
4806 New_Occurrence_Of (Equivalent_Type (E), Sloc (N)));
4810 -- Set the entity. Note that the reason we call Set_Entity for the
4811 -- overloadable case, as opposed to Set_Entity_With_Style_Check is
4812 -- that in the overloaded case, the initial call can set the wrong
4813 -- homonym. The call that sets the right homonym is in Sem_Res and
4814 -- that call does use Set_Entity_With_Style_Check, so we don't miss
4817 if Is_Overloadable (E) then
4820 Set_Entity_With_Style_Check (N, E);
4826 Set_Etype (N, Get_Full_View (Etype (E)));
4829 if Debug_Flag_E then
4830 Write_Str (" found ");
4831 Write_Entity_Info (E, " ");
4834 -- If the Ekind of the entity is Void, it means that all homonyms
4835 -- are hidden from all visibility (RM 8.3(5,14-20)). However, this
4836 -- test is skipped if the current scope is a record and the name is
4837 -- a pragma argument expression (case of Atomic and Volatile pragmas
4838 -- and possibly other similar pragmas added later, which are allowed
4839 -- to reference components in the current record).
4841 if Ekind (E) = E_Void
4843 (not Is_Record_Type (Current_Scope)
4844 or else Nkind (Parent (N)) /= N_Pragma_Argument_Association)
4846 Premature_Usage (N);
4848 -- If the entity is overloadable, collect all interpretations of the
4849 -- name for subsequent overload resolution. We optimize a bit here to
4850 -- do this only if we have an overloadable entity that is not on its
4851 -- own on the homonym chain.
4853 elsif Is_Overloadable (E)
4854 and then (Present (Homonym (E)) or else Current_Entity (N) /= E)
4856 Collect_Interps (N);
4858 -- If no homonyms were visible, the entity is unambiguous
4860 if not Is_Overloaded (N) then
4861 if not Is_Actual_Parameter then
4862 Generate_Reference (E, N);
4866 -- Case of non-overloadable entity, set the entity providing that
4867 -- we do not have the case of a discriminant reference within a
4868 -- default expression. Such references are replaced with the
4869 -- corresponding discriminal, which is the formal corresponding to
4870 -- to the discriminant in the initialization procedure.
4873 -- Entity is unambiguous, indicate that it is referenced here
4875 -- For a renaming of an object, always generate simple reference,
4876 -- we don't try to keep track of assignments in this case.
4878 if Is_Object (E) and then Present (Renamed_Object (E)) then
4879 Generate_Reference (E, N);
4881 -- If the renamed entity is a private protected component,
4882 -- reference the original component as well. This needs to be
4883 -- done because the private renamings are installed before any
4884 -- analysis has occurred. Reference to a private component will
4885 -- resolve to the renaming and the original component will be
4886 -- left unreferenced, hence the following.
4888 if Is_Prival (E) then
4889 Generate_Reference (Prival_Link (E), N);
4892 -- One odd case is that we do not want to set the Referenced flag
4893 -- if the entity is a label, and the identifier is the label in
4894 -- the source, since this is not a reference from the point of
4895 -- view of the user.
4897 elsif Nkind (Parent (N)) = N_Label then
4899 R : constant Boolean := Referenced (E);
4902 -- Generate reference unless this is an actual parameter
4903 -- (see comment below)
4905 if Is_Actual_Parameter then
4906 Generate_Reference (E, N);
4907 Set_Referenced (E, R);
4911 -- Normal case, not a label: generate reference
4913 -- ??? It is too early to generate a reference here even if the
4914 -- entity is unambiguous, because the tree is not sufficiently
4915 -- typed at this point for Generate_Reference to determine
4916 -- whether this reference modifies the denoted object (because
4917 -- implicit dereferences cannot be identified prior to full type
4920 -- The Is_Actual_Parameter routine takes care of one of these
4921 -- cases but there are others probably ???
4923 -- If the entity is the LHS of an assignment, and is a variable
4924 -- (rather than a package prefix), we can mark it as a
4925 -- modification right away, to avoid duplicate references.
4928 if not Is_Actual_Parameter then
4930 and then Ekind (E) /= E_Package
4931 and then Ekind (E) /= E_Generic_Package
4933 Generate_Reference (E, N, 'm');
4935 Generate_Reference (E, N);
4939 Check_Nested_Access (E);
4942 Set_Entity_Or_Discriminal (N, E);
4944 if Ada_Version >= Ada_2012
4946 (Nkind (Parent (N)) in N_Subexpr
4947 or else Nkind (Parent (N)) = N_Object_Declaration)
4949 Check_Implicit_Dereference (N, Etype (E));
4953 end Find_Direct_Name;
4955 ------------------------
4956 -- Find_Expanded_Name --
4957 ------------------------
4959 -- This routine searches the homonym chain of the entity until it finds
4960 -- an entity declared in the scope denoted by the prefix. If the entity
4961 -- is private, it may nevertheless be immediately visible, if we are in
4962 -- the scope of its declaration.
4964 procedure Find_Expanded_Name (N : Node_Id) is
4965 Selector : constant Node_Id := Selector_Name (N);
4966 Candidate : Entity_Id := Empty;
4972 P_Name := Entity (Prefix (N));
4975 -- If the prefix is a renamed package, look for the entity in the
4976 -- original package.
4978 if Ekind (P_Name) = E_Package
4979 and then Present (Renamed_Object (P_Name))
4981 P_Name := Renamed_Object (P_Name);
4983 -- Rewrite node with entity field pointing to renamed object
4985 Rewrite (Prefix (N), New_Copy (Prefix (N)));
4986 Set_Entity (Prefix (N), P_Name);
4988 -- If the prefix is an object of a concurrent type, look for
4989 -- the entity in the associated task or protected type.
4991 elsif Is_Concurrent_Type (Etype (P_Name)) then
4992 P_Name := Etype (P_Name);
4995 Id := Current_Entity (Selector);
4998 Is_New_Candidate : Boolean;
5001 while Present (Id) loop
5002 if Scope (Id) = P_Name then
5004 Is_New_Candidate := True;
5006 -- Ada 2005 (AI-217): Handle shadow entities associated with types
5007 -- declared in limited-withed nested packages. We don't need to
5008 -- handle E_Incomplete_Subtype entities because the entities in
5009 -- the limited view are always E_Incomplete_Type entities (see
5010 -- Build_Limited_Views). Regarding the expression used to evaluate
5011 -- the scope, it is important to note that the limited view also
5012 -- has shadow entities associated nested packages. For this reason
5013 -- the correct scope of the entity is the scope of the real entity
5014 -- The non-limited view may itself be incomplete, in which case
5015 -- get the full view if available.
5017 elsif From_With_Type (Id)
5018 and then Is_Type (Id)
5019 and then Ekind (Id) = E_Incomplete_Type
5020 and then Present (Non_Limited_View (Id))
5021 and then Scope (Non_Limited_View (Id)) = P_Name
5023 Candidate := Get_Full_View (Non_Limited_View (Id));
5024 Is_New_Candidate := True;
5027 Is_New_Candidate := False;
5030 if Is_New_Candidate then
5031 if Is_Child_Unit (Id) then
5032 exit when Is_Visible_Child_Unit (Id)
5033 or else Is_Immediately_Visible (Id);
5036 exit when not Is_Hidden (Id)
5037 or else Is_Immediately_Visible (Id);
5046 and then (Ekind (P_Name) = E_Procedure
5048 Ekind (P_Name) = E_Function)
5049 and then Is_Generic_Instance (P_Name)
5051 -- Expanded name denotes entity in (instance of) generic subprogram.
5052 -- The entity may be in the subprogram instance, or may denote one of
5053 -- the formals, which is declared in the enclosing wrapper package.
5055 P_Name := Scope (P_Name);
5057 Id := Current_Entity (Selector);
5058 while Present (Id) loop
5059 exit when Scope (Id) = P_Name;
5064 if No (Id) or else Chars (Id) /= Chars (Selector) then
5065 Set_Etype (N, Any_Type);
5067 -- If we are looking for an entity defined in System, try to find it
5068 -- in the child package that may have been provided as an extension
5069 -- to System. The Extend_System pragma will have supplied the name of
5070 -- the extension, which may have to be loaded.
5072 if Chars (P_Name) = Name_System
5073 and then Scope (P_Name) = Standard_Standard
5074 and then Present (System_Extend_Unit)
5075 and then Present_System_Aux (N)
5077 Set_Entity (Prefix (N), System_Aux_Id);
5078 Find_Expanded_Name (N);
5081 elsif Nkind (Selector) = N_Operator_Symbol
5082 and then Has_Implicit_Operator (N)
5084 -- There is an implicit instance of the predefined operator in
5085 -- the given scope. The operator entity is defined in Standard.
5086 -- Has_Implicit_Operator makes the node into an Expanded_Name.
5090 elsif Nkind (Selector) = N_Character_Literal
5091 and then Has_Implicit_Character_Literal (N)
5093 -- If there is no literal defined in the scope denoted by the
5094 -- prefix, the literal may belong to (a type derived from)
5095 -- Standard_Character, for which we have no explicit literals.
5100 -- If the prefix is a single concurrent object, use its name in
5101 -- the error message, rather than that of the anonymous type.
5103 if Is_Concurrent_Type (P_Name)
5104 and then Is_Internal_Name (Chars (P_Name))
5106 Error_Msg_Node_2 := Entity (Prefix (N));
5108 Error_Msg_Node_2 := P_Name;
5111 if P_Name = System_Aux_Id then
5112 P_Name := Scope (P_Name);
5113 Set_Entity (Prefix (N), P_Name);
5116 if Present (Candidate) then
5118 -- If we know that the unit is a child unit we can give a more
5119 -- accurate error message.
5121 if Is_Child_Unit (Candidate) then
5123 -- If the candidate is a private child unit and we are in
5124 -- the visible part of a public unit, specialize the error
5125 -- message. There might be a private with_clause for it,
5126 -- but it is not currently active.
5128 if Is_Private_Descendant (Candidate)
5129 and then Ekind (Current_Scope) = E_Package
5130 and then not In_Private_Part (Current_Scope)
5131 and then not Is_Private_Descendant (Current_Scope)
5133 Error_Msg_N ("private child unit& is not visible here",
5136 -- Normal case where we have a missing with for a child unit
5139 Error_Msg_Qual_Level := 99;
5140 Error_Msg_NE -- CODEFIX
5141 ("missing `WITH &;`", Selector, Candidate);
5142 Error_Msg_Qual_Level := 0;
5145 -- Here we don't know that this is a child unit
5148 Error_Msg_NE ("& is not a visible entity of&", N, Selector);
5152 -- Within the instantiation of a child unit, the prefix may
5153 -- denote the parent instance, but the selector has the name
5154 -- of the original child. Find whether we are within the
5155 -- corresponding instance, and get the proper entity, which
5156 -- can only be an enclosing scope.
5159 and then In_Open_Scopes (P_Name)
5160 and then Is_Generic_Instance (P_Name)
5163 S : Entity_Id := Current_Scope;
5167 for J in reverse 0 .. Scope_Stack.Last loop
5168 S := Scope_Stack.Table (J).Entity;
5170 exit when S = Standard_Standard;
5172 if Ekind_In (S, E_Function,
5176 P := Generic_Parent (Specification
5177 (Unit_Declaration_Node (S)));
5180 and then Chars (Scope (P)) = Chars (O_Name)
5181 and then Chars (P) = Chars (Selector)
5192 -- If this is a selection from Ada, System or Interfaces, then
5193 -- we assume a missing with for the corresponding package.
5195 if Is_Known_Unit (N) then
5196 if not Error_Posted (N) then
5197 Error_Msg_Node_2 := Selector;
5198 Error_Msg_N -- CODEFIX
5199 ("missing `WITH &.&;`", Prefix (N));
5202 -- If this is a selection from a dummy package, then suppress
5203 -- the error message, of course the entity is missing if the
5204 -- package is missing!
5206 elsif Sloc (Error_Msg_Node_2) = No_Location then
5209 -- Here we have the case of an undefined component
5213 -- The prefix may hide a homonym in the context that
5214 -- declares the desired entity. This error can use a
5215 -- specialized message.
5217 if In_Open_Scopes (P_Name)
5218 and then Present (Homonym (P_Name))
5219 and then Is_Compilation_Unit (Homonym (P_Name))
5221 (Is_Immediately_Visible (Homonym (P_Name))
5222 or else Is_Visible_Child_Unit (Homonym (P_Name)))
5225 H : constant Entity_Id := Homonym (P_Name);
5228 Id := First_Entity (H);
5229 while Present (Id) loop
5230 if Chars (Id) = Chars (Selector) then
5231 Error_Msg_Qual_Level := 99;
5232 Error_Msg_Name_1 := Chars (Selector);
5234 ("% not declared in&", N, P_Name);
5236 ("\use fully qualified name starting with"
5237 & " Standard to make& visible", N, H);
5238 Error_Msg_Qual_Level := 0;
5245 -- If not found, standard error message
5247 Error_Msg_NE ("& not declared in&", N, Selector);
5253 Error_Msg_NE ("& not declared in&", N, Selector);
5256 -- Check for misspelling of some entity in prefix
5258 Id := First_Entity (P_Name);
5259 while Present (Id) loop
5260 if Is_Bad_Spelling_Of (Chars (Id), Chars (Selector))
5261 and then not Is_Internal_Name (Chars (Id))
5263 Error_Msg_NE -- CODEFIX
5264 ("possible misspelling of&", Selector, Id);
5271 -- Specialize the message if this may be an instantiation
5272 -- of a child unit that was not mentioned in the context.
5274 if Nkind (Parent (N)) = N_Package_Instantiation
5275 and then Is_Generic_Instance (Entity (Prefix (N)))
5276 and then Is_Compilation_Unit
5277 (Generic_Parent (Parent (Entity (Prefix (N)))))
5279 Error_Msg_Node_2 := Selector;
5280 Error_Msg_N -- CODEFIX
5281 ("\missing `WITH &.&;`", Prefix (N));
5291 if Comes_From_Source (N)
5292 and then Is_Remote_Access_To_Subprogram_Type (Id)
5293 and then Present (Equivalent_Type (Id))
5295 -- If we are not actually generating distribution code (i.e. the
5296 -- current PCS is the dummy non-distributed version), then the
5297 -- Equivalent_Type will be missing, and Id should be treated as
5298 -- a regular access-to-subprogram type.
5300 Id := Equivalent_Type (Id);
5301 Set_Chars (Selector, Chars (Id));
5304 -- Ada 2005 (AI-50217): Check usage of entities in limited withed units
5306 if Ekind (P_Name) = E_Package
5307 and then From_With_Type (P_Name)
5309 if From_With_Type (Id)
5310 or else Is_Type (Id)
5311 or else Ekind (Id) = E_Package
5316 ("limited withed package can only be used to access "
5317 & "incomplete types",
5322 if Is_Task_Type (P_Name)
5323 and then ((Ekind (Id) = E_Entry
5324 and then Nkind (Parent (N)) /= N_Attribute_Reference)
5326 (Ekind (Id) = E_Entry_Family
5328 Nkind (Parent (Parent (N))) /= N_Attribute_Reference))
5330 -- It is an entry call after all, either to the current task (which
5331 -- will deadlock) or to an enclosing task.
5333 Analyze_Selected_Component (N);
5337 Change_Selected_Component_To_Expanded_Name (N);
5339 -- Do style check and generate reference, but skip both steps if this
5340 -- entity has homonyms, since we may not have the right homonym set yet.
5341 -- The proper homonym will be set during the resolve phase.
5343 if Has_Homonym (Id) then
5346 Set_Entity_Or_Discriminal (N, Id);
5349 Generate_Reference (Id, N, 'm');
5351 Generate_Reference (Id, N);
5355 if Is_Type (Id) then
5358 Set_Etype (N, Get_Full_View (Etype (Id)));
5361 -- Check for violation of No_Wide_Characters
5363 Check_Wide_Character_Restriction (Id, N);
5365 -- If the Ekind of the entity is Void, it means that all homonyms are
5366 -- hidden from all visibility (RM 8.3(5,14-20)).
5368 if Ekind (Id) = E_Void then
5369 Premature_Usage (N);
5371 elsif Is_Overloadable (Id)
5372 and then Present (Homonym (Id))
5375 H : Entity_Id := Homonym (Id);
5378 while Present (H) loop
5379 if Scope (H) = Scope (Id)
5382 or else Is_Immediately_Visible (H))
5384 Collect_Interps (N);
5391 -- If an extension of System is present, collect possible explicit
5392 -- overloadings declared in the extension.
5394 if Chars (P_Name) = Name_System
5395 and then Scope (P_Name) = Standard_Standard
5396 and then Present (System_Extend_Unit)
5397 and then Present_System_Aux (N)
5399 H := Current_Entity (Id);
5401 while Present (H) loop
5402 if Scope (H) = System_Aux_Id then
5403 Add_One_Interp (N, H, Etype (H));
5412 if Nkind (Selector_Name (N)) = N_Operator_Symbol
5413 and then Scope (Id) /= Standard_Standard
5415 -- In addition to user-defined operators in the given scope, there
5416 -- may be an implicit instance of the predefined operator. The
5417 -- operator (defined in Standard) is found in Has_Implicit_Operator,
5418 -- and added to the interpretations. Procedure Add_One_Interp will
5419 -- determine which hides which.
5421 if Has_Implicit_Operator (N) then
5425 end Find_Expanded_Name;
5427 -------------------------
5428 -- Find_Renamed_Entity --
5429 -------------------------
5431 function Find_Renamed_Entity
5435 Is_Actual : Boolean := False) return Entity_Id
5438 I1 : Interp_Index := 0; -- Suppress junk warnings
5444 function Enclosing_Instance return Entity_Id;
5445 -- If the renaming determines the entity for the default of a formal
5446 -- subprogram nested within another instance, choose the innermost
5447 -- candidate. This is because if the formal has a box, and we are within
5448 -- an enclosing instance where some candidate interpretations are local
5449 -- to this enclosing instance, we know that the default was properly
5450 -- resolved when analyzing the generic, so we prefer the local
5451 -- candidates to those that are external. This is not always the case
5452 -- but is a reasonable heuristic on the use of nested generics. The
5453 -- proper solution requires a full renaming model.
5455 function Is_Visible_Operation (Op : Entity_Id) return Boolean;
5456 -- If the renamed entity is an implicit operator, check whether it is
5457 -- visible because its operand type is properly visible. This check
5458 -- applies to explicit renamed entities that appear in the source in a
5459 -- renaming declaration or a formal subprogram instance, but not to
5460 -- default generic actuals with a name.
5462 function Report_Overload return Entity_Id;
5463 -- List possible interpretations, and specialize message in the
5464 -- case of a generic actual.
5466 function Within (Inner, Outer : Entity_Id) return Boolean;
5467 -- Determine whether a candidate subprogram is defined within the
5468 -- enclosing instance. If yes, it has precedence over outer candidates.
5470 ------------------------
5471 -- Enclosing_Instance --
5472 ------------------------
5474 function Enclosing_Instance return Entity_Id is
5478 if not Is_Generic_Instance (Current_Scope)
5479 and then not Is_Actual
5484 S := Scope (Current_Scope);
5485 while S /= Standard_Standard loop
5486 if Is_Generic_Instance (S) then
5494 end Enclosing_Instance;
5496 --------------------------
5497 -- Is_Visible_Operation --
5498 --------------------------
5500 function Is_Visible_Operation (Op : Entity_Id) return Boolean is
5506 if Ekind (Op) /= E_Operator
5507 or else Scope (Op) /= Standard_Standard
5508 or else (In_Instance
5511 or else Present (Enclosing_Instance)))
5516 -- For a fixed point type operator, check the resulting type,
5517 -- because it may be a mixed mode integer * fixed operation.
5519 if Present (Next_Formal (First_Formal (New_S)))
5520 and then Is_Fixed_Point_Type (Etype (New_S))
5522 Typ := Etype (New_S);
5524 Typ := Etype (First_Formal (New_S));
5527 Btyp := Base_Type (Typ);
5529 if Nkind (Nam) /= N_Expanded_Name then
5530 return (In_Open_Scopes (Scope (Btyp))
5531 or else Is_Potentially_Use_Visible (Btyp)
5532 or else In_Use (Btyp)
5533 or else In_Use (Scope (Btyp)));
5536 Scop := Entity (Prefix (Nam));
5538 if Ekind (Scop) = E_Package
5539 and then Present (Renamed_Object (Scop))
5541 Scop := Renamed_Object (Scop);
5544 -- Operator is visible if prefix of expanded name denotes
5545 -- scope of type, or else type is defined in System_Aux
5546 -- and the prefix denotes System.
5548 return Scope (Btyp) = Scop
5549 or else (Scope (Btyp) = System_Aux_Id
5550 and then Scope (Scope (Btyp)) = Scop);
5553 end Is_Visible_Operation;
5559 function Within (Inner, Outer : Entity_Id) return Boolean is
5563 Sc := Scope (Inner);
5564 while Sc /= Standard_Standard loop
5575 ---------------------
5576 -- Report_Overload --
5577 ---------------------
5579 function Report_Overload return Entity_Id is
5582 Error_Msg_NE -- CODEFIX
5583 ("ambiguous actual subprogram&, " &
5584 "possible interpretations:", N, Nam);
5586 Error_Msg_N -- CODEFIX
5587 ("ambiguous subprogram, " &
5588 "possible interpretations:", N);
5591 List_Interps (Nam, N);
5593 end Report_Overload;
5595 -- Start of processing for Find_Renamed_Entity
5599 Candidate_Renaming := Empty;
5601 if not Is_Overloaded (Nam) then
5602 if Entity_Matches_Spec (Entity (Nam), New_S) then
5603 Candidate_Renaming := New_S;
5605 if Is_Visible_Operation (Entity (Nam)) then
5606 Old_S := Entity (Nam);
5610 Present (First_Formal (Entity (Nam)))
5611 and then Present (First_Formal (New_S))
5612 and then (Base_Type (Etype (First_Formal (Entity (Nam))))
5613 = Base_Type (Etype (First_Formal (New_S))))
5615 Candidate_Renaming := Entity (Nam);
5619 Get_First_Interp (Nam, Ind, It);
5620 while Present (It.Nam) loop
5621 if Entity_Matches_Spec (It.Nam, New_S)
5622 and then Is_Visible_Operation (It.Nam)
5624 if Old_S /= Any_Id then
5626 -- Note: The call to Disambiguate only happens if a
5627 -- previous interpretation was found, in which case I1
5628 -- has received a value.
5630 It1 := Disambiguate (Nam, I1, Ind, Etype (Old_S));
5632 if It1 = No_Interp then
5633 Inst := Enclosing_Instance;
5635 if Present (Inst) then
5636 if Within (It.Nam, Inst) then
5637 if Within (Old_S, Inst) then
5639 -- Choose the innermost subprogram, which would
5640 -- have hidden the outer one in the generic.
5642 if Scope_Depth (It.Nam) <
5651 elsif Within (Old_S, Inst) then
5655 return Report_Overload;
5658 -- If not within an instance, ambiguity is real
5661 return Report_Overload;
5675 Present (First_Formal (It.Nam))
5676 and then Present (First_Formal (New_S))
5677 and then (Base_Type (Etype (First_Formal (It.Nam)))
5678 = Base_Type (Etype (First_Formal (New_S))))
5680 Candidate_Renaming := It.Nam;
5683 Get_Next_Interp (Ind, It);
5686 Set_Entity (Nam, Old_S);
5688 if Old_S /= Any_Id then
5689 Set_Is_Overloaded (Nam, False);
5694 end Find_Renamed_Entity;
5696 -----------------------------
5697 -- Find_Selected_Component --
5698 -----------------------------
5700 procedure Find_Selected_Component (N : Node_Id) is
5701 P : constant Node_Id := Prefix (N);
5704 -- Entity denoted by prefix
5714 if Nkind (P) = N_Error then
5718 -- Selector name cannot be a character literal or an operator symbol in
5719 -- SPARK, except for the operator symbol in a renaming.
5721 if Restriction_Check_Required (SPARK) then
5722 if Nkind (Selector_Name (N)) = N_Character_Literal then
5723 Check_SPARK_Restriction
5724 ("character literal cannot be prefixed", N);
5725 elsif Nkind (Selector_Name (N)) = N_Operator_Symbol
5726 and then Nkind (Parent (N)) /= N_Subprogram_Renaming_Declaration
5728 Check_SPARK_Restriction ("operator symbol cannot be prefixed", N);
5732 -- If the selector already has an entity, the node has been constructed
5733 -- in the course of expansion, and is known to be valid. Do not verify
5734 -- that it is defined for the type (it may be a private component used
5735 -- in the expansion of record equality).
5737 if Present (Entity (Selector_Name (N))) then
5739 or else Etype (N) = Any_Type
5742 Sel_Name : constant Node_Id := Selector_Name (N);
5743 Selector : constant Entity_Id := Entity (Sel_Name);
5747 Set_Etype (Sel_Name, Etype (Selector));
5749 if not Is_Entity_Name (P) then
5753 -- Build an actual subtype except for the first parameter
5754 -- of an init proc, where this actual subtype is by
5755 -- definition incorrect, since the object is uninitialized
5756 -- (and does not even have defined discriminants etc.)
5758 if Is_Entity_Name (P)
5759 and then Ekind (Entity (P)) = E_Function
5761 Nam := New_Copy (P);
5763 if Is_Overloaded (P) then
5764 Save_Interps (P, Nam);
5768 Make_Function_Call (Sloc (P), Name => Nam));
5770 Analyze_Selected_Component (N);
5773 elsif Ekind (Selector) = E_Component
5774 and then (not Is_Entity_Name (P)
5775 or else Chars (Entity (P)) /= Name_uInit)
5777 -- Do not build the subtype when referencing components of
5778 -- dispatch table wrappers. Required to avoid generating
5779 -- elaboration code with HI runtimes. JVM and .NET use a
5780 -- modified version of Ada.Tags which does not contain RE_
5781 -- Dispatch_Table_Wrapper and RE_No_Dispatch_Table_Wrapper.
5782 -- Avoid raising RE_Not_Available exception in those cases.
5784 if VM_Target = No_VM
5785 and then RTU_Loaded (Ada_Tags)
5787 ((RTE_Available (RE_Dispatch_Table_Wrapper)
5788 and then Scope (Selector) =
5789 RTE (RE_Dispatch_Table_Wrapper))
5791 (RTE_Available (RE_No_Dispatch_Table_Wrapper)
5792 and then Scope (Selector) =
5793 RTE (RE_No_Dispatch_Table_Wrapper)))
5799 Build_Actual_Subtype_Of_Component
5800 (Etype (Selector), N);
5807 if No (C_Etype) then
5808 C_Etype := Etype (Selector);
5810 Insert_Action (N, C_Etype);
5811 C_Etype := Defining_Identifier (C_Etype);
5814 Set_Etype (N, C_Etype);
5817 -- If this is the name of an entry or protected operation, and
5818 -- the prefix is an access type, insert an explicit dereference,
5819 -- so that entry calls are treated uniformly.
5821 if Is_Access_Type (Etype (P))
5822 and then Is_Concurrent_Type (Designated_Type (Etype (P)))
5825 New_P : constant Node_Id :=
5826 Make_Explicit_Dereference (Sloc (P),
5827 Prefix => Relocate_Node (P));
5830 Set_Etype (P, Designated_Type (Etype (Prefix (P))));
5834 -- If the selected component appears within a default expression
5835 -- and it has an actual subtype, the pre-analysis has not yet
5836 -- completed its analysis, because Insert_Actions is disabled in
5837 -- that context. Within the init proc of the enclosing type we
5838 -- must complete this analysis, if an actual subtype was created.
5840 elsif Inside_Init_Proc then
5842 Typ : constant Entity_Id := Etype (N);
5843 Decl : constant Node_Id := Declaration_Node (Typ);
5845 if Nkind (Decl) = N_Subtype_Declaration
5846 and then not Analyzed (Decl)
5847 and then Is_List_Member (Decl)
5848 and then No (Parent (Decl))
5851 Insert_Action (N, Decl);
5858 elsif Is_Entity_Name (P) then
5859 P_Name := Entity (P);
5861 -- The prefix may denote an enclosing type which is the completion
5862 -- of an incomplete type declaration.
5864 if Is_Type (P_Name) then
5865 Set_Entity (P, Get_Full_View (P_Name));
5866 Set_Etype (P, Entity (P));
5867 P_Name := Entity (P);
5870 P_Type := Base_Type (Etype (P));
5872 if Debug_Flag_E then
5873 Write_Str ("Found prefix type to be ");
5874 Write_Entity_Info (P_Type, " "); Write_Eol;
5877 -- First check for components of a record object (not the
5878 -- result of a call, which is handled below).
5880 if Is_Appropriate_For_Record (P_Type)
5881 and then not Is_Overloadable (P_Name)
5882 and then not Is_Type (P_Name)
5884 -- Selected component of record. Type checking will validate
5885 -- name of selector.
5886 -- ??? could we rewrite an implicit dereference into an explicit
5889 Analyze_Selected_Component (N);
5891 -- Reference to type name in predicate/invariant expression
5893 elsif Is_Appropriate_For_Entry_Prefix (P_Type)
5894 and then not In_Open_Scopes (P_Name)
5895 and then (not Is_Concurrent_Type (Etype (P_Name))
5896 or else not In_Open_Scopes (Etype (P_Name)))
5898 -- Call to protected operation or entry. Type checking is
5899 -- needed on the prefix.
5901 Analyze_Selected_Component (N);
5903 elsif (In_Open_Scopes (P_Name)
5904 and then Ekind (P_Name) /= E_Void
5905 and then not Is_Overloadable (P_Name))
5906 or else (Is_Concurrent_Type (Etype (P_Name))
5907 and then In_Open_Scopes (Etype (P_Name)))
5909 -- Prefix denotes an enclosing loop, block, or task, i.e. an
5910 -- enclosing construct that is not a subprogram or accept.
5912 Find_Expanded_Name (N);
5914 elsif Ekind (P_Name) = E_Package then
5915 Find_Expanded_Name (N);
5917 elsif Is_Overloadable (P_Name) then
5919 -- The subprogram may be a renaming (of an enclosing scope) as
5920 -- in the case of the name of the generic within an instantiation.
5922 if Ekind_In (P_Name, E_Procedure, E_Function)
5923 and then Present (Alias (P_Name))
5924 and then Is_Generic_Instance (Alias (P_Name))
5926 P_Name := Alias (P_Name);
5929 if Is_Overloaded (P) then
5931 -- The prefix must resolve to a unique enclosing construct
5934 Found : Boolean := False;
5939 Get_First_Interp (P, Ind, It);
5940 while Present (It.Nam) loop
5941 if In_Open_Scopes (It.Nam) then
5944 "prefix must be unique enclosing scope", N);
5945 Set_Entity (N, Any_Id);
5946 Set_Etype (N, Any_Type);
5955 Get_Next_Interp (Ind, It);
5960 if In_Open_Scopes (P_Name) then
5961 Set_Entity (P, P_Name);
5962 Set_Is_Overloaded (P, False);
5963 Find_Expanded_Name (N);
5966 -- If no interpretation as an expanded name is possible, it
5967 -- must be a selected component of a record returned by a
5968 -- function call. Reformat prefix as a function call, the rest
5969 -- is done by type resolution. If the prefix is procedure or
5970 -- entry, as is P.X; this is an error.
5972 if Ekind (P_Name) /= E_Function
5973 and then (not Is_Overloaded (P)
5975 Nkind (Parent (N)) = N_Procedure_Call_Statement)
5977 -- Prefix may mention a package that is hidden by a local
5978 -- declaration: let the user know. Scan the full homonym
5979 -- chain, the candidate package may be anywhere on it.
5981 if Present (Homonym (Current_Entity (P_Name))) then
5983 P_Name := Current_Entity (P_Name);
5985 while Present (P_Name) loop
5986 exit when Ekind (P_Name) = E_Package;
5987 P_Name := Homonym (P_Name);
5990 if Present (P_Name) then
5991 Error_Msg_Sloc := Sloc (Entity (Prefix (N)));
5994 ("package& is hidden by declaration#",
5997 Set_Entity (Prefix (N), P_Name);
5998 Find_Expanded_Name (N);
6001 P_Name := Entity (Prefix (N));
6006 ("invalid prefix in selected component&", N, P_Name);
6007 Change_Selected_Component_To_Expanded_Name (N);
6008 Set_Entity (N, Any_Id);
6009 Set_Etype (N, Any_Type);
6012 Nam := New_Copy (P);
6013 Save_Interps (P, Nam);
6015 Make_Function_Call (Sloc (P), Name => Nam));
6017 Analyze_Selected_Component (N);
6021 -- Remaining cases generate various error messages
6024 -- Format node as expanded name, to avoid cascaded errors
6026 Change_Selected_Component_To_Expanded_Name (N);
6027 Set_Entity (N, Any_Id);
6028 Set_Etype (N, Any_Type);
6030 -- Issue error message, but avoid this if error issued already.
6031 -- Use identifier of prefix if one is available.
6033 if P_Name = Any_Id then
6036 elsif Ekind (P_Name) = E_Void then
6037 Premature_Usage (P);
6039 elsif Nkind (P) /= N_Attribute_Reference then
6041 "invalid prefix in selected component&", P);
6043 if Is_Access_Type (P_Type)
6044 and then Ekind (Designated_Type (P_Type)) = E_Incomplete_Type
6047 ("\dereference must not be of an incomplete type " &
6053 "invalid prefix in selected component", P);
6057 -- Selector name is restricted in SPARK
6059 if Nkind (N) = N_Expanded_Name
6060 and then Restriction_Check_Required (SPARK)
6062 if Is_Subprogram (P_Name) then
6063 Check_SPARK_Restriction
6064 ("prefix of expanded name cannot be a subprogram", P);
6065 elsif Ekind (P_Name) = E_Loop then
6066 Check_SPARK_Restriction
6067 ("prefix of expanded name cannot be a loop statement", P);
6072 -- If prefix is not the name of an entity, it must be an expression,
6073 -- whose type is appropriate for a record. This is determined by
6076 Analyze_Selected_Component (N);
6078 end Find_Selected_Component;
6084 procedure Find_Type (N : Node_Id) is
6094 elsif Nkind (N) = N_Attribute_Reference then
6096 -- Class attribute. This is not valid in Ada 83 mode, but we do not
6097 -- need to enforce that at this point, since the declaration of the
6098 -- tagged type in the prefix would have been flagged already.
6100 if Attribute_Name (N) = Name_Class then
6101 Check_Restriction (No_Dispatch, N);
6102 Find_Type (Prefix (N));
6104 -- Propagate error from bad prefix
6106 if Etype (Prefix (N)) = Any_Type then
6107 Set_Entity (N, Any_Type);
6108 Set_Etype (N, Any_Type);
6112 T := Base_Type (Entity (Prefix (N)));
6114 -- Case where type is not known to be tagged. Its appearance in
6115 -- the prefix of the 'Class attribute indicates that the full view
6118 if not Is_Tagged_Type (T) then
6119 if Ekind (T) = E_Incomplete_Type then
6121 -- It is legal to denote the class type of an incomplete
6122 -- type. The full type will have to be tagged, of course.
6123 -- In Ada 2005 this usage is declared obsolescent, so we
6124 -- warn accordingly. This usage is only legal if the type
6125 -- is completed in the current scope, and not for a limited
6128 if Ada_Version >= Ada_2005 then
6130 -- Test whether the Available_View of a limited type view
6131 -- is tagged, since the limited view may not be marked as
6132 -- tagged if the type itself has an untagged incomplete
6133 -- type view in its package.
6135 if From_With_Type (T)
6136 and then not Is_Tagged_Type (Available_View (T))
6139 ("prefix of Class attribute must be tagged", N);
6140 Set_Etype (N, Any_Type);
6141 Set_Entity (N, Any_Type);
6144 -- ??? This test is temporarily disabled (always False)
6145 -- because it causes an unwanted warning on GNAT sources
6146 -- (built with -gnatg, which includes Warn_On_Obsolescent_
6147 -- Feature). Once this issue is cleared in the sources, it
6150 elsif Warn_On_Obsolescent_Feature
6154 ("applying 'Class to an untagged incomplete type"
6155 & " is an obsolescent feature (RM J.11)", N);
6159 Set_Is_Tagged_Type (T);
6160 Set_Direct_Primitive_Operations (T, New_Elmt_List);
6161 Make_Class_Wide_Type (T);
6162 Set_Entity (N, Class_Wide_Type (T));
6163 Set_Etype (N, Class_Wide_Type (T));
6165 elsif Ekind (T) = E_Private_Type
6166 and then not Is_Generic_Type (T)
6167 and then In_Private_Part (Scope (T))
6169 -- The Class attribute can be applied to an untagged private
6170 -- type fulfilled by a tagged type prior to the full type
6171 -- declaration (but only within the parent package's private
6172 -- part). Create the class-wide type now and check that the
6173 -- full type is tagged later during its analysis. Note that
6174 -- we do not mark the private type as tagged, unlike the
6175 -- case of incomplete types, because the type must still
6176 -- appear untagged to outside units.
6178 if No (Class_Wide_Type (T)) then
6179 Make_Class_Wide_Type (T);
6182 Set_Entity (N, Class_Wide_Type (T));
6183 Set_Etype (N, Class_Wide_Type (T));
6186 -- Should we introduce a type Any_Tagged and use Wrong_Type
6187 -- here, it would be a bit more consistent???
6190 ("tagged type required, found}",
6191 Prefix (N), First_Subtype (T));
6192 Set_Entity (N, Any_Type);
6196 -- Case of tagged type
6199 if Is_Concurrent_Type (T) then
6200 if No (Corresponding_Record_Type (Entity (Prefix (N)))) then
6202 -- Previous error. Use current type, which at least
6203 -- provides some operations.
6205 C := Entity (Prefix (N));
6208 C := Class_Wide_Type
6209 (Corresponding_Record_Type (Entity (Prefix (N))));
6213 C := Class_Wide_Type (Entity (Prefix (N)));
6216 Set_Entity_With_Style_Check (N, C);
6217 Generate_Reference (C, N);
6221 -- Base attribute, not allowed in Ada 83
6223 elsif Attribute_Name (N) = Name_Base then
6224 Error_Msg_Name_1 := Name_Base;
6225 Check_SPARK_Restriction
6226 ("attribute% is only allowed as prefix of another attribute", N);
6228 if Ada_Version = Ada_83 and then Comes_From_Source (N) then
6230 ("(Ada 83) Base attribute not allowed in subtype mark", N);
6233 Find_Type (Prefix (N));
6234 Typ := Entity (Prefix (N));
6236 if Ada_Version >= Ada_95
6237 and then not Is_Scalar_Type (Typ)
6238 and then not Is_Generic_Type (Typ)
6241 ("prefix of Base attribute must be scalar type",
6244 elsif Warn_On_Redundant_Constructs
6245 and then Base_Type (Typ) = Typ
6247 Error_Msg_NE -- CODEFIX
6248 ("?redundant attribute, & is its own base type", N, Typ);
6251 T := Base_Type (Typ);
6253 -- Rewrite attribute reference with type itself (see similar
6254 -- processing in Analyze_Attribute, case Base). Preserve prefix
6255 -- if present, for other legality checks.
6257 if Nkind (Prefix (N)) = N_Expanded_Name then
6259 Make_Expanded_Name (Sloc (N),
6261 Prefix => New_Copy (Prefix (Prefix (N))),
6262 Selector_Name => New_Reference_To (T, Sloc (N))));
6265 Rewrite (N, New_Reference_To (T, Sloc (N)));
6272 elsif Attribute_Name (N) = Name_Stub_Type then
6274 -- This is handled in Analyze_Attribute
6278 -- All other attributes are invalid in a subtype mark
6281 Error_Msg_N ("invalid attribute in subtype mark", N);
6287 if Is_Entity_Name (N) then
6288 T_Name := Entity (N);
6290 Error_Msg_N ("subtype mark required in this context", N);
6291 Set_Etype (N, Any_Type);
6295 if T_Name = Any_Id or else Etype (N) = Any_Type then
6297 -- Undefined id. Make it into a valid type
6299 Set_Entity (N, Any_Type);
6301 elsif not Is_Type (T_Name)
6302 and then T_Name /= Standard_Void_Type
6304 Error_Msg_Sloc := Sloc (T_Name);
6305 Error_Msg_N ("subtype mark required in this context", N);
6306 Error_Msg_NE ("\\found & declared#", N, T_Name);
6307 Set_Entity (N, Any_Type);
6310 -- If the type is an incomplete type created to handle
6311 -- anonymous access components of a record type, then the
6312 -- incomplete type is the visible entity and subsequent
6313 -- references will point to it. Mark the original full
6314 -- type as referenced, to prevent spurious warnings.
6316 if Is_Incomplete_Type (T_Name)
6317 and then Present (Full_View (T_Name))
6318 and then not Comes_From_Source (T_Name)
6320 Set_Referenced (Full_View (T_Name));
6323 T_Name := Get_Full_View (T_Name);
6325 -- Ada 2005 (AI-251, AI-50217): Handle interfaces visible through
6326 -- limited-with clauses
6328 if From_With_Type (T_Name)
6329 and then Ekind (T_Name) in Incomplete_Kind
6330 and then Present (Non_Limited_View (T_Name))
6331 and then Is_Interface (Non_Limited_View (T_Name))
6333 T_Name := Non_Limited_View (T_Name);
6336 if In_Open_Scopes (T_Name) then
6337 if Ekind (Base_Type (T_Name)) = E_Task_Type then
6339 -- In Ada 2005, a task name can be used in an access
6340 -- definition within its own body. It cannot be used
6341 -- in the discriminant part of the task declaration,
6342 -- nor anywhere else in the declaration because entries
6343 -- cannot have access parameters.
6345 if Ada_Version >= Ada_2005
6346 and then Nkind (Parent (N)) = N_Access_Definition
6348 Set_Entity (N, T_Name);
6349 Set_Etype (N, T_Name);
6351 if Has_Completion (T_Name) then
6356 ("task type cannot be used as type mark " &
6357 "within its own declaration", N);
6362 ("task type cannot be used as type mark " &
6363 "within its own spec or body", N);
6366 elsif Ekind (Base_Type (T_Name)) = E_Protected_Type then
6368 -- In Ada 2005, a protected name can be used in an access
6369 -- definition within its own body.
6371 if Ada_Version >= Ada_2005
6372 and then Nkind (Parent (N)) = N_Access_Definition
6374 Set_Entity (N, T_Name);
6375 Set_Etype (N, T_Name);
6380 ("protected type cannot be used as type mark " &
6381 "within its own spec or body", N);
6385 Error_Msg_N ("type declaration cannot refer to itself", N);
6388 Set_Etype (N, Any_Type);
6389 Set_Entity (N, Any_Type);
6390 Set_Error_Posted (T_Name);
6394 Set_Entity (N, T_Name);
6395 Set_Etype (N, T_Name);
6399 if Present (Etype (N)) and then Comes_From_Source (N) then
6400 if Is_Fixed_Point_Type (Etype (N)) then
6401 Check_Restriction (No_Fixed_Point, N);
6402 elsif Is_Floating_Point_Type (Etype (N)) then
6403 Check_Restriction (No_Floating_Point, N);
6408 ------------------------------------
6409 -- Has_Implicit_Character_Literal --
6410 ------------------------------------
6412 function Has_Implicit_Character_Literal (N : Node_Id) return Boolean is
6414 Found : Boolean := False;
6415 P : constant Entity_Id := Entity (Prefix (N));
6416 Priv_Id : Entity_Id := Empty;
6419 if Ekind (P) = E_Package
6420 and then not In_Open_Scopes (P)
6422 Priv_Id := First_Private_Entity (P);
6425 if P = Standard_Standard then
6426 Change_Selected_Component_To_Expanded_Name (N);
6427 Rewrite (N, Selector_Name (N));
6429 Set_Etype (Original_Node (N), Standard_Character);
6433 Id := First_Entity (P);
6435 and then Id /= Priv_Id
6437 if Is_Standard_Character_Type (Id) and then Is_Base_Type (Id) then
6439 -- We replace the node with the literal itself, resolve as a
6440 -- character, and set the type correctly.
6443 Change_Selected_Component_To_Expanded_Name (N);
6444 Rewrite (N, Selector_Name (N));
6447 Set_Etype (Original_Node (N), Id);
6451 -- More than one type derived from Character in given scope.
6452 -- Collect all possible interpretations.
6454 Add_One_Interp (N, Id, Id);
6462 end Has_Implicit_Character_Literal;
6464 ----------------------
6465 -- Has_Private_With --
6466 ----------------------
6468 function Has_Private_With (E : Entity_Id) return Boolean is
6469 Comp_Unit : constant Node_Id := Cunit (Current_Sem_Unit);
6473 Item := First (Context_Items (Comp_Unit));
6474 while Present (Item) loop
6475 if Nkind (Item) = N_With_Clause
6476 and then Private_Present (Item)
6477 and then Entity (Name (Item)) = E
6486 end Has_Private_With;
6488 ---------------------------
6489 -- Has_Implicit_Operator --
6490 ---------------------------
6492 function Has_Implicit_Operator (N : Node_Id) return Boolean is
6493 Op_Id : constant Name_Id := Chars (Selector_Name (N));
6494 P : constant Entity_Id := Entity (Prefix (N));
6496 Priv_Id : Entity_Id := Empty;
6498 procedure Add_Implicit_Operator
6500 Op_Type : Entity_Id := Empty);
6501 -- Add implicit interpretation to node N, using the type for which a
6502 -- predefined operator exists. If the operator yields a boolean type,
6503 -- the Operand_Type is implicitly referenced by the operator, and a
6504 -- reference to it must be generated.
6506 ---------------------------
6507 -- Add_Implicit_Operator --
6508 ---------------------------
6510 procedure Add_Implicit_Operator
6512 Op_Type : Entity_Id := Empty)
6514 Predef_Op : Entity_Id;
6517 Predef_Op := Current_Entity (Selector_Name (N));
6519 while Present (Predef_Op)
6520 and then Scope (Predef_Op) /= Standard_Standard
6522 Predef_Op := Homonym (Predef_Op);
6525 if Nkind (N) = N_Selected_Component then
6526 Change_Selected_Component_To_Expanded_Name (N);
6529 -- If the context is an unanalyzed function call, determine whether
6530 -- a binary or unary interpretation is required.
6532 if Nkind (Parent (N)) = N_Indexed_Component then
6534 Is_Binary_Call : constant Boolean :=
6536 (Next (First (Expressions (Parent (N)))));
6537 Is_Binary_Op : constant Boolean :=
6539 (Predef_Op) /= Last_Entity (Predef_Op);
6540 Predef_Op2 : constant Entity_Id := Homonym (Predef_Op);
6543 if Is_Binary_Call then
6544 if Is_Binary_Op then
6545 Add_One_Interp (N, Predef_Op, T);
6547 Add_One_Interp (N, Predef_Op2, T);
6551 if not Is_Binary_Op then
6552 Add_One_Interp (N, Predef_Op, T);
6554 Add_One_Interp (N, Predef_Op2, T);
6560 Add_One_Interp (N, Predef_Op, T);
6562 -- For operators with unary and binary interpretations, if
6563 -- context is not a call, add both
6565 if Present (Homonym (Predef_Op)) then
6566 Add_One_Interp (N, Homonym (Predef_Op), T);
6570 -- The node is a reference to a predefined operator, and
6571 -- an implicit reference to the type of its operands.
6573 if Present (Op_Type) then
6574 Generate_Operator_Reference (N, Op_Type);
6576 Generate_Operator_Reference (N, T);
6578 end Add_Implicit_Operator;
6580 -- Start of processing for Has_Implicit_Operator
6583 if Ekind (P) = E_Package
6584 and then not In_Open_Scopes (P)
6586 Priv_Id := First_Private_Entity (P);
6589 Id := First_Entity (P);
6593 -- Boolean operators: an implicit declaration exists if the scope
6594 -- contains a declaration for a derived Boolean type, or for an
6595 -- array of Boolean type.
6597 when Name_Op_And | Name_Op_Not | Name_Op_Or | Name_Op_Xor =>
6598 while Id /= Priv_Id loop
6599 if Valid_Boolean_Arg (Id) and then Is_Base_Type (Id) then
6600 Add_Implicit_Operator (Id);
6607 -- Equality: look for any non-limited type (result is Boolean)
6609 when Name_Op_Eq | Name_Op_Ne =>
6610 while Id /= Priv_Id loop
6612 and then not Is_Limited_Type (Id)
6613 and then Is_Base_Type (Id)
6615 Add_Implicit_Operator (Standard_Boolean, Id);
6622 -- Comparison operators: scalar type, or array of scalar
6624 when Name_Op_Lt | Name_Op_Le | Name_Op_Gt | Name_Op_Ge =>
6625 while Id /= Priv_Id loop
6626 if (Is_Scalar_Type (Id)
6627 or else (Is_Array_Type (Id)
6628 and then Is_Scalar_Type (Component_Type (Id))))
6629 and then Is_Base_Type (Id)
6631 Add_Implicit_Operator (Standard_Boolean, Id);
6638 -- Arithmetic operators: any numeric type
6648 while Id /= Priv_Id loop
6649 if Is_Numeric_Type (Id) and then Is_Base_Type (Id) then
6650 Add_Implicit_Operator (Id);
6657 -- Concatenation: any one-dimensional array type
6659 when Name_Op_Concat =>
6660 while Id /= Priv_Id loop
6661 if Is_Array_Type (Id)
6662 and then Number_Dimensions (Id) = 1
6663 and then Is_Base_Type (Id)
6665 Add_Implicit_Operator (Id);
6672 -- What is the others condition here? Should we be using a
6673 -- subtype of Name_Id that would restrict to operators ???
6675 when others => null;
6678 -- If we fall through, then we do not have an implicit operator
6682 end Has_Implicit_Operator;
6684 -----------------------------------
6685 -- Has_Loop_In_Inner_Open_Scopes --
6686 -----------------------------------
6688 function Has_Loop_In_Inner_Open_Scopes (S : Entity_Id) return Boolean is
6690 -- Several scope stacks are maintained by Scope_Stack. The base of the
6691 -- currently active scope stack is denoted by the Is_Active_Stack_Base
6692 -- flag in the scope stack entry. Note that the scope stacks used to
6693 -- simply be delimited implicitly by the presence of Standard_Standard
6694 -- at their base, but there now are cases where this is not sufficient
6695 -- because Standard_Standard actually may appear in the middle of the
6696 -- active set of scopes.
6698 for J in reverse 0 .. Scope_Stack.Last loop
6700 -- S was reached without seing a loop scope first
6702 if Scope_Stack.Table (J).Entity = S then
6705 -- S was not yet reached, so it contains at least one inner loop
6707 elsif Ekind (Scope_Stack.Table (J).Entity) = E_Loop then
6711 -- Check Is_Active_Stack_Base to tell us when to stop, as there are
6712 -- cases where Standard_Standard appears in the middle of the active
6713 -- set of scopes. This affects the declaration and overriding of
6714 -- private inherited operations in instantiations of generic child
6717 pragma Assert (not Scope_Stack.Table (J).Is_Active_Stack_Base);
6720 raise Program_Error; -- unreachable
6721 end Has_Loop_In_Inner_Open_Scopes;
6723 --------------------
6724 -- In_Open_Scopes --
6725 --------------------
6727 function In_Open_Scopes (S : Entity_Id) return Boolean is
6729 -- Several scope stacks are maintained by Scope_Stack. The base of the
6730 -- currently active scope stack is denoted by the Is_Active_Stack_Base
6731 -- flag in the scope stack entry. Note that the scope stacks used to
6732 -- simply be delimited implicitly by the presence of Standard_Standard
6733 -- at their base, but there now are cases where this is not sufficient
6734 -- because Standard_Standard actually may appear in the middle of the
6735 -- active set of scopes.
6737 for J in reverse 0 .. Scope_Stack.Last loop
6738 if Scope_Stack.Table (J).Entity = S then
6742 -- Check Is_Active_Stack_Base to tell us when to stop, as there are
6743 -- cases where Standard_Standard appears in the middle of the active
6744 -- set of scopes. This affects the declaration and overriding of
6745 -- private inherited operations in instantiations of generic child
6748 exit when Scope_Stack.Table (J).Is_Active_Stack_Base;
6754 -----------------------------
6755 -- Inherit_Renamed_Profile --
6756 -----------------------------
6758 procedure Inherit_Renamed_Profile (New_S : Entity_Id; Old_S : Entity_Id) is
6765 if Ekind (Old_S) = E_Operator then
6766 New_F := First_Formal (New_S);
6768 while Present (New_F) loop
6769 Set_Etype (New_F, Base_Type (Etype (New_F)));
6770 Next_Formal (New_F);
6773 Set_Etype (New_S, Base_Type (Etype (New_S)));
6776 New_F := First_Formal (New_S);
6777 Old_F := First_Formal (Old_S);
6779 while Present (New_F) loop
6780 New_T := Etype (New_F);
6781 Old_T := Etype (Old_F);
6783 -- If the new type is a renaming of the old one, as is the
6784 -- case for actuals in instances, retain its name, to simplify
6785 -- later disambiguation.
6787 if Nkind (Parent (New_T)) = N_Subtype_Declaration
6788 and then Is_Entity_Name (Subtype_Indication (Parent (New_T)))
6789 and then Entity (Subtype_Indication (Parent (New_T))) = Old_T
6793 Set_Etype (New_F, Old_T);
6796 Next_Formal (New_F);
6797 Next_Formal (Old_F);
6800 if Ekind_In (Old_S, E_Function, E_Enumeration_Literal) then
6801 Set_Etype (New_S, Etype (Old_S));
6804 end Inherit_Renamed_Profile;
6810 procedure Initialize is
6815 -------------------------
6816 -- Install_Use_Clauses --
6817 -------------------------
6819 procedure Install_Use_Clauses
6821 Force_Installation : Boolean := False)
6829 while Present (U) loop
6831 -- Case of USE package
6833 if Nkind (U) = N_Use_Package_Clause then
6834 P := First (Names (U));
6835 while Present (P) loop
6838 if Ekind (Id) = E_Package then
6840 Note_Redundant_Use (P);
6842 elsif Present (Renamed_Object (Id))
6843 and then In_Use (Renamed_Object (Id))
6845 Note_Redundant_Use (P);
6847 elsif Force_Installation or else Applicable_Use (P) then
6848 Use_One_Package (Id, U);
6859 P := First (Subtype_Marks (U));
6860 while Present (P) loop
6861 if not Is_Entity_Name (P)
6862 or else No (Entity (P))
6866 elsif Entity (P) /= Any_Type then
6874 Next_Use_Clause (U);
6876 end Install_Use_Clauses;
6878 -------------------------------------
6879 -- Is_Appropriate_For_Entry_Prefix --
6880 -------------------------------------
6882 function Is_Appropriate_For_Entry_Prefix (T : Entity_Id) return Boolean is
6883 P_Type : Entity_Id := T;
6886 if Is_Access_Type (P_Type) then
6887 P_Type := Designated_Type (P_Type);
6890 return Is_Task_Type (P_Type) or else Is_Protected_Type (P_Type);
6891 end Is_Appropriate_For_Entry_Prefix;
6893 -------------------------------
6894 -- Is_Appropriate_For_Record --
6895 -------------------------------
6897 function Is_Appropriate_For_Record (T : Entity_Id) return Boolean is
6899 function Has_Components (T1 : Entity_Id) return Boolean;
6900 -- Determine if given type has components (i.e. is either a record
6901 -- type or a type that has discriminants).
6903 --------------------
6904 -- Has_Components --
6905 --------------------
6907 function Has_Components (T1 : Entity_Id) return Boolean is
6909 return Is_Record_Type (T1)
6910 or else (Is_Private_Type (T1) and then Has_Discriminants (T1))
6911 or else (Is_Task_Type (T1) and then Has_Discriminants (T1))
6912 or else (Is_Incomplete_Type (T1)
6913 and then From_With_Type (T1)
6914 and then Present (Non_Limited_View (T1))
6915 and then Is_Record_Type
6916 (Get_Full_View (Non_Limited_View (T1))));
6919 -- Start of processing for Is_Appropriate_For_Record
6924 and then (Has_Components (T)
6925 or else (Is_Access_Type (T)
6926 and then Has_Components (Designated_Type (T))));
6927 end Is_Appropriate_For_Record;
6929 ------------------------
6930 -- Note_Redundant_Use --
6931 ------------------------
6933 procedure Note_Redundant_Use (Clause : Node_Id) is
6934 Pack_Name : constant Entity_Id := Entity (Clause);
6935 Cur_Use : constant Node_Id := Current_Use_Clause (Pack_Name);
6936 Decl : constant Node_Id := Parent (Clause);
6938 Prev_Use : Node_Id := Empty;
6939 Redundant : Node_Id := Empty;
6940 -- The Use_Clause which is actually redundant. In the simplest case it
6941 -- is Pack itself, but when we compile a body we install its context
6942 -- before that of its spec, in which case it is the use_clause in the
6943 -- spec that will appear to be redundant, and we want the warning to be
6944 -- placed on the body. Similar complications appear when the redundancy
6945 -- is between a child unit and one of its ancestors.
6948 Set_Redundant_Use (Clause, True);
6950 if not Comes_From_Source (Clause)
6952 or else not Warn_On_Redundant_Constructs
6957 if not Is_Compilation_Unit (Current_Scope) then
6959 -- If the use_clause is in an inner scope, it is made redundant by
6960 -- some clause in the current context, with one exception: If we're
6961 -- compiling a nested package body, and the use_clause comes from the
6962 -- corresponding spec, the clause is not necessarily fully redundant,
6963 -- so we should not warn. If a warning was warranted, it would have
6964 -- been given when the spec was processed.
6966 if Nkind (Parent (Decl)) = N_Package_Specification then
6968 Package_Spec_Entity : constant Entity_Id :=
6969 Defining_Unit_Name (Parent (Decl));
6971 if In_Package_Body (Package_Spec_Entity) then
6977 Redundant := Clause;
6978 Prev_Use := Cur_Use;
6980 elsif Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Body then
6982 Cur_Unit : constant Unit_Number_Type := Get_Source_Unit (Cur_Use);
6983 New_Unit : constant Unit_Number_Type := Get_Source_Unit (Clause);
6987 if Cur_Unit = New_Unit then
6989 -- Redundant clause in same body
6991 Redundant := Clause;
6992 Prev_Use := Cur_Use;
6994 elsif Cur_Unit = Current_Sem_Unit then
6996 -- If the new clause is not in the current unit it has been
6997 -- analyzed first, and it makes the other one redundant.
6998 -- However, if the new clause appears in a subunit, Cur_Unit
6999 -- is still the parent, and in that case the redundant one
7000 -- is the one appearing in the subunit.
7002 if Nkind (Unit (Cunit (New_Unit))) = N_Subunit then
7003 Redundant := Clause;
7004 Prev_Use := Cur_Use;
7006 -- Most common case: redundant clause in body,
7007 -- original clause in spec. Current scope is spec entity.
7012 Unit (Library_Unit (Cunit (Current_Sem_Unit))))
7014 Redundant := Cur_Use;
7018 -- The new clause may appear in an unrelated unit, when
7019 -- the parents of a generic are being installed prior to
7020 -- instantiation. In this case there must be no warning.
7021 -- We detect this case by checking whether the current top
7022 -- of the stack is related to the current compilation.
7024 Scop := Current_Scope;
7025 while Present (Scop)
7026 and then Scop /= Standard_Standard
7028 if Is_Compilation_Unit (Scop)
7029 and then not Is_Child_Unit (Scop)
7033 elsif Scop = Cunit_Entity (Current_Sem_Unit) then
7037 Scop := Scope (Scop);
7040 Redundant := Cur_Use;
7044 elsif New_Unit = Current_Sem_Unit then
7045 Redundant := Clause;
7046 Prev_Use := Cur_Use;
7049 -- Neither is the current unit, so they appear in parent or
7050 -- sibling units. Warning will be emitted elsewhere.
7056 elsif Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Declaration
7057 and then Present (Parent_Spec (Unit (Cunit (Current_Sem_Unit))))
7059 -- Use_clause is in child unit of current unit, and the child unit
7060 -- appears in the context of the body of the parent, so it has been
7061 -- installed first, even though it is the redundant one. Depending on
7062 -- their placement in the context, the visible or the private parts
7063 -- of the two units, either might appear as redundant, but the
7064 -- message has to be on the current unit.
7066 if Get_Source_Unit (Cur_Use) = Current_Sem_Unit then
7067 Redundant := Cur_Use;
7070 Redundant := Clause;
7071 Prev_Use := Cur_Use;
7074 -- If the new use clause appears in the private part of a parent unit
7075 -- it may appear to be redundant w.r.t. a use clause in a child unit,
7076 -- but the previous use clause was needed in the visible part of the
7077 -- child, and no warning should be emitted.
7079 if Nkind (Parent (Decl)) = N_Package_Specification
7081 List_Containing (Decl) = Private_Declarations (Parent (Decl))
7084 Par : constant Entity_Id := Defining_Entity (Parent (Decl));
7085 Spec : constant Node_Id :=
7086 Specification (Unit (Cunit (Current_Sem_Unit)));
7089 if Is_Compilation_Unit (Par)
7090 and then Par /= Cunit_Entity (Current_Sem_Unit)
7091 and then Parent (Cur_Use) = Spec
7093 List_Containing (Cur_Use) = Visible_Declarations (Spec)
7100 -- Finally, if the current use clause is in the context then
7101 -- the clause is redundant when it is nested within the unit.
7103 elsif Nkind (Parent (Cur_Use)) = N_Compilation_Unit
7104 and then Nkind (Parent (Parent (Clause))) /= N_Compilation_Unit
7105 and then Get_Source_Unit (Cur_Use) = Get_Source_Unit (Clause)
7107 Redundant := Clause;
7108 Prev_Use := Cur_Use;
7114 if Present (Redundant) then
7115 Error_Msg_Sloc := Sloc (Prev_Use);
7116 Error_Msg_NE -- CODEFIX
7117 ("& is already use-visible through previous use clause #?",
7118 Redundant, Pack_Name);
7120 end Note_Redundant_Use;
7126 procedure Pop_Scope is
7127 SST : Scope_Stack_Entry renames Scope_Stack.Table (Scope_Stack.Last);
7128 S : constant Entity_Id := SST.Entity;
7131 if Debug_Flag_E then
7135 -- Set Default_Storage_Pool field of the library unit if necessary
7137 if Ekind_In (S, E_Package, E_Generic_Package)
7139 Nkind (Parent (Unit_Declaration_Node (S))) = N_Compilation_Unit
7142 Aux : constant Node_Id :=
7143 Aux_Decls_Node (Parent (Unit_Declaration_Node (S)));
7145 if No (Default_Storage_Pool (Aux)) then
7146 Set_Default_Storage_Pool (Aux, Default_Pool);
7151 Scope_Suppress := SST.Save_Scope_Suppress;
7152 Local_Suppress_Stack_Top := SST.Save_Local_Suppress_Stack_Top;
7153 Check_Policy_List := SST.Save_Check_Policy_List;
7154 Default_Pool := SST.Save_Default_Storage_Pool;
7156 if Debug_Flag_W then
7157 Write_Str ("<-- exiting scope: ");
7158 Write_Name (Chars (Current_Scope));
7159 Write_Str (", Depth=");
7160 Write_Int (Int (Scope_Stack.Last));
7164 End_Use_Clauses (SST.First_Use_Clause);
7166 -- If the actions to be wrapped are still there they will get lost
7167 -- causing incomplete code to be generated. It is better to abort in
7168 -- this case (and we do the abort even with assertions off since the
7169 -- penalty is incorrect code generation)
7171 if SST.Actions_To_Be_Wrapped_Before /= No_List
7173 SST.Actions_To_Be_Wrapped_After /= No_List
7175 raise Program_Error;
7178 -- Free last subprogram name if allocated, and pop scope
7180 Free (SST.Last_Subprogram_Name);
7181 Scope_Stack.Decrement_Last;
7188 procedure Push_Scope (S : Entity_Id) is
7189 E : constant Entity_Id := Scope (S);
7192 if Ekind (S) = E_Void then
7195 -- Set scope depth if not a non-concurrent type, and we have not yet set
7196 -- the scope depth. This means that we have the first occurrence of the
7197 -- scope, and this is where the depth is set.
7199 elsif (not Is_Type (S) or else Is_Concurrent_Type (S))
7200 and then not Scope_Depth_Set (S)
7202 if S = Standard_Standard then
7203 Set_Scope_Depth_Value (S, Uint_0);
7205 elsif Is_Child_Unit (S) then
7206 Set_Scope_Depth_Value (S, Uint_1);
7208 elsif not Is_Record_Type (Current_Scope) then
7209 if Ekind (S) = E_Loop then
7210 Set_Scope_Depth_Value (S, Scope_Depth (Current_Scope));
7212 Set_Scope_Depth_Value (S, Scope_Depth (Current_Scope) + 1);
7217 Scope_Stack.Increment_Last;
7220 SST : Scope_Stack_Entry renames Scope_Stack.Table (Scope_Stack.Last);
7224 SST.Save_Scope_Suppress := Scope_Suppress;
7225 SST.Save_Local_Suppress_Stack_Top := Local_Suppress_Stack_Top;
7226 SST.Save_Check_Policy_List := Check_Policy_List;
7227 SST.Save_Default_Storage_Pool := Default_Pool;
7229 if Scope_Stack.Last > Scope_Stack.First then
7230 SST.Component_Alignment_Default := Scope_Stack.Table
7231 (Scope_Stack.Last - 1).
7232 Component_Alignment_Default;
7235 SST.Last_Subprogram_Name := null;
7236 SST.Is_Transient := False;
7237 SST.Node_To_Be_Wrapped := Empty;
7238 SST.Pending_Freeze_Actions := No_List;
7239 SST.Actions_To_Be_Wrapped_Before := No_List;
7240 SST.Actions_To_Be_Wrapped_After := No_List;
7241 SST.First_Use_Clause := Empty;
7242 SST.Is_Active_Stack_Base := False;
7243 SST.Previous_Visibility := False;
7246 if Debug_Flag_W then
7247 Write_Str ("--> new scope: ");
7248 Write_Name (Chars (Current_Scope));
7249 Write_Str (", Id=");
7250 Write_Int (Int (Current_Scope));
7251 Write_Str (", Depth=");
7252 Write_Int (Int (Scope_Stack.Last));
7256 -- Deal with copying flags from the previous scope to this one. This is
7257 -- not necessary if either scope is standard, or if the new scope is a
7260 if S /= Standard_Standard
7261 and then Scope (S) /= Standard_Standard
7262 and then not Is_Child_Unit (S)
7264 if Nkind (E) not in N_Entity then
7268 -- Copy categorization flags from Scope (S) to S, this is not done
7269 -- when Scope (S) is Standard_Standard since propagation is from
7270 -- library unit entity inwards. Copy other relevant attributes as
7271 -- well (Discard_Names in particular).
7273 -- We only propagate inwards for library level entities,
7274 -- inner level subprograms do not inherit the categorization.
7276 if Is_Library_Level_Entity (S) then
7277 Set_Is_Preelaborated (S, Is_Preelaborated (E));
7278 Set_Is_Shared_Passive (S, Is_Shared_Passive (E));
7279 Set_Discard_Names (S, Discard_Names (E));
7280 Set_Suppress_Value_Tracking_On_Call
7281 (S, Suppress_Value_Tracking_On_Call (E));
7282 Set_Categorization_From_Scope (E => S, Scop => E);
7286 if Is_Child_Unit (S)
7287 and then Present (E)
7288 and then Ekind_In (E, E_Package, E_Generic_Package)
7290 Nkind (Parent (Unit_Declaration_Node (E))) = N_Compilation_Unit
7293 Aux : constant Node_Id :=
7294 Aux_Decls_Node (Parent (Unit_Declaration_Node (E)));
7296 if Present (Default_Storage_Pool (Aux)) then
7297 Default_Pool := Default_Storage_Pool (Aux);
7303 ---------------------
7304 -- Premature_Usage --
7305 ---------------------
7307 procedure Premature_Usage (N : Node_Id) is
7308 Kind : constant Node_Kind := Nkind (Parent (Entity (N)));
7309 E : Entity_Id := Entity (N);
7312 -- Within an instance, the analysis of the actual for a formal object
7313 -- does not see the name of the object itself. This is significant only
7314 -- if the object is an aggregate, where its analysis does not do any
7315 -- name resolution on component associations. (see 4717-008). In such a
7316 -- case, look for the visible homonym on the chain.
7319 and then Present (Homonym (E))
7324 and then not In_Open_Scopes (Scope (E))
7331 Set_Etype (N, Etype (E));
7336 if Kind = N_Component_Declaration then
7338 ("component&! cannot be used before end of record declaration", N);
7340 elsif Kind = N_Parameter_Specification then
7342 ("formal parameter&! cannot be used before end of specification",
7345 elsif Kind = N_Discriminant_Specification then
7347 ("discriminant&! cannot be used before end of discriminant part",
7350 elsif Kind = N_Procedure_Specification
7351 or else Kind = N_Function_Specification
7354 ("subprogram&! cannot be used before end of its declaration",
7357 elsif Kind = N_Full_Type_Declaration then
7359 ("type& cannot be used before end of its declaration!", N);
7363 ("object& cannot be used before end of its declaration!", N);
7365 end Premature_Usage;
7367 ------------------------
7368 -- Present_System_Aux --
7369 ------------------------
7371 function Present_System_Aux (N : Node_Id := Empty) return Boolean is
7373 Aux_Name : Unit_Name_Type;
7374 Unum : Unit_Number_Type;
7379 function Find_System (C_Unit : Node_Id) return Entity_Id;
7380 -- Scan context clause of compilation unit to find with_clause
7387 function Find_System (C_Unit : Node_Id) return Entity_Id is
7388 With_Clause : Node_Id;
7391 With_Clause := First (Context_Items (C_Unit));
7392 while Present (With_Clause) loop
7393 if (Nkind (With_Clause) = N_With_Clause
7394 and then Chars (Name (With_Clause)) = Name_System)
7395 and then Comes_From_Source (With_Clause)
7406 -- Start of processing for Present_System_Aux
7409 -- The child unit may have been loaded and analyzed already
7411 if Present (System_Aux_Id) then
7414 -- If no previous pragma for System.Aux, nothing to load
7416 elsif No (System_Extend_Unit) then
7419 -- Use the unit name given in the pragma to retrieve the unit.
7420 -- Verify that System itself appears in the context clause of the
7421 -- current compilation. If System is not present, an error will
7422 -- have been reported already.
7425 With_Sys := Find_System (Cunit (Current_Sem_Unit));
7427 The_Unit := Unit (Cunit (Current_Sem_Unit));
7431 (Nkind (The_Unit) = N_Package_Body
7432 or else (Nkind (The_Unit) = N_Subprogram_Body
7434 not Acts_As_Spec (Cunit (Current_Sem_Unit))))
7436 With_Sys := Find_System (Library_Unit (Cunit (Current_Sem_Unit)));
7440 and then Present (N)
7442 -- If we are compiling a subunit, we need to examine its
7443 -- context as well (Current_Sem_Unit is the parent unit);
7445 The_Unit := Parent (N);
7446 while Nkind (The_Unit) /= N_Compilation_Unit loop
7447 The_Unit := Parent (The_Unit);
7450 if Nkind (Unit (The_Unit)) = N_Subunit then
7451 With_Sys := Find_System (The_Unit);
7455 if No (With_Sys) then
7459 Loc := Sloc (With_Sys);
7460 Get_Name_String (Chars (Expression (System_Extend_Unit)));
7461 Name_Buffer (8 .. Name_Len + 7) := Name_Buffer (1 .. Name_Len);
7462 Name_Buffer (1 .. 7) := "system.";
7463 Name_Buffer (Name_Len + 8) := '%';
7464 Name_Buffer (Name_Len + 9) := 's';
7465 Name_Len := Name_Len + 9;
7466 Aux_Name := Name_Find;
7470 (Load_Name => Aux_Name,
7473 Error_Node => With_Sys);
7475 if Unum /= No_Unit then
7476 Semantics (Cunit (Unum));
7478 Defining_Entity (Specification (Unit (Cunit (Unum))));
7481 Make_With_Clause (Loc,
7483 Make_Expanded_Name (Loc,
7484 Chars => Chars (System_Aux_Id),
7485 Prefix => New_Reference_To (Scope (System_Aux_Id), Loc),
7486 Selector_Name => New_Reference_To (System_Aux_Id, Loc)));
7488 Set_Entity (Name (Withn), System_Aux_Id);
7490 Set_Library_Unit (Withn, Cunit (Unum));
7491 Set_Corresponding_Spec (Withn, System_Aux_Id);
7492 Set_First_Name (Withn, True);
7493 Set_Implicit_With (Withn, True);
7495 Insert_After (With_Sys, Withn);
7496 Mark_Rewrite_Insertion (Withn);
7497 Set_Context_Installed (Withn);
7501 -- Here if unit load failed
7504 Error_Msg_Name_1 := Name_System;
7505 Error_Msg_Name_2 := Chars (Expression (System_Extend_Unit));
7507 ("extension package `%.%` does not exist",
7508 Opt.System_Extend_Unit);
7512 end Present_System_Aux;
7514 -------------------------
7515 -- Restore_Scope_Stack --
7516 -------------------------
7518 procedure Restore_Scope_Stack (Handle_Use : Boolean := True) is
7521 Comp_Unit : Node_Id;
7522 In_Child : Boolean := False;
7523 Full_Vis : Boolean := True;
7524 SS_Last : constant Int := Scope_Stack.Last;
7527 -- Restore visibility of previous scope stack, if any
7529 for J in reverse 0 .. Scope_Stack.Last loop
7530 exit when Scope_Stack.Table (J).Entity = Standard_Standard
7531 or else No (Scope_Stack.Table (J).Entity);
7533 S := Scope_Stack.Table (J).Entity;
7535 if not Is_Hidden_Open_Scope (S) then
7537 -- If the parent scope is hidden, its entities are hidden as
7538 -- well, unless the entity is the instantiation currently
7541 if not Is_Hidden_Open_Scope (Scope (S))
7542 or else not Analyzed (Parent (S))
7543 or else Scope (S) = Standard_Standard
7545 Set_Is_Immediately_Visible (S, True);
7548 E := First_Entity (S);
7549 while Present (E) loop
7550 if Is_Child_Unit (E) then
7551 if not From_With_Type (E) then
7552 Set_Is_Immediately_Visible (E,
7553 Is_Visible_Child_Unit (E) or else In_Open_Scopes (E));
7557 (Nkind (Parent (E)) = N_Defining_Program_Unit_Name
7559 Nkind (Parent (Parent (E))) = N_Package_Specification);
7560 Set_Is_Immediately_Visible (E,
7561 Limited_View_Installed (Parent (Parent (E))));
7564 Set_Is_Immediately_Visible (E, True);
7570 and then Is_Package_Or_Generic_Package (S)
7572 -- We are in the visible part of the package scope
7574 exit when E = First_Private_Entity (S);
7578 -- The visibility of child units (siblings of current compilation)
7579 -- must be restored in any case. Their declarations may appear
7580 -- after the private part of the parent.
7582 if not Full_Vis then
7583 while Present (E) loop
7584 if Is_Child_Unit (E) then
7585 Set_Is_Immediately_Visible (E,
7586 Is_Visible_Child_Unit (E) or else In_Open_Scopes (E));
7594 if Is_Child_Unit (S)
7595 and not In_Child -- check only for current unit
7599 -- Restore visibility of parents according to whether the child
7600 -- is private and whether we are in its visible part.
7602 Comp_Unit := Parent (Unit_Declaration_Node (S));
7604 if Nkind (Comp_Unit) = N_Compilation_Unit
7605 and then Private_Present (Comp_Unit)
7609 elsif Is_Package_Or_Generic_Package (S)
7610 and then (In_Private_Part (S) or else In_Package_Body (S))
7614 -- if S is the scope of some instance (which has already been
7615 -- seen on the stack) it does not affect the visibility of
7618 elsif Is_Hidden_Open_Scope (S) then
7621 elsif (Ekind (S) = E_Procedure
7622 or else Ekind (S) = E_Function)
7623 and then Has_Completion (S)
7634 if SS_Last >= Scope_Stack.First
7635 and then Scope_Stack.Table (SS_Last).Entity /= Standard_Standard
7638 Install_Use_Clauses (Scope_Stack.Table (SS_Last).First_Use_Clause);
7640 end Restore_Scope_Stack;
7642 ----------------------
7643 -- Save_Scope_Stack --
7644 ----------------------
7646 procedure Save_Scope_Stack (Handle_Use : Boolean := True) is
7649 SS_Last : constant Int := Scope_Stack.Last;
7652 if SS_Last >= Scope_Stack.First
7653 and then Scope_Stack.Table (SS_Last).Entity /= Standard_Standard
7656 End_Use_Clauses (Scope_Stack.Table (SS_Last).First_Use_Clause);
7659 -- If the call is from within a compilation unit, as when called from
7660 -- Rtsfind, make current entries in scope stack invisible while we
7661 -- analyze the new unit.
7663 for J in reverse 0 .. SS_Last loop
7664 exit when Scope_Stack.Table (J).Entity = Standard_Standard
7665 or else No (Scope_Stack.Table (J).Entity);
7667 S := Scope_Stack.Table (J).Entity;
7668 Set_Is_Immediately_Visible (S, False);
7670 E := First_Entity (S);
7671 while Present (E) loop
7672 Set_Is_Immediately_Visible (E, False);
7678 end Save_Scope_Stack;
7684 procedure Set_Use (L : List_Id) is
7686 Pack_Name : Node_Id;
7693 while Present (Decl) loop
7694 if Nkind (Decl) = N_Use_Package_Clause then
7695 Chain_Use_Clause (Decl);
7697 Pack_Name := First (Names (Decl));
7698 while Present (Pack_Name) loop
7699 Pack := Entity (Pack_Name);
7701 if Ekind (Pack) = E_Package
7702 and then Applicable_Use (Pack_Name)
7704 Use_One_Package (Pack, Decl);
7710 elsif Nkind (Decl) = N_Use_Type_Clause then
7711 Chain_Use_Clause (Decl);
7713 Id := First (Subtype_Marks (Decl));
7714 while Present (Id) loop
7715 if Entity (Id) /= Any_Type then
7728 ---------------------
7729 -- Use_One_Package --
7730 ---------------------
7732 procedure Use_One_Package (P : Entity_Id; N : Node_Id) is
7735 Current_Instance : Entity_Id := Empty;
7737 Private_With_OK : Boolean := False;
7740 if Ekind (P) /= E_Package then
7745 Set_Current_Use_Clause (P, N);
7747 -- Ada 2005 (AI-50217): Check restriction
7749 if From_With_Type (P) then
7750 Error_Msg_N ("limited withed package cannot appear in use clause", N);
7753 -- Find enclosing instance, if any
7756 Current_Instance := Current_Scope;
7757 while not Is_Generic_Instance (Current_Instance) loop
7758 Current_Instance := Scope (Current_Instance);
7761 if No (Hidden_By_Use_Clause (N)) then
7762 Set_Hidden_By_Use_Clause (N, New_Elmt_List);
7766 -- If unit is a package renaming, indicate that the renamed
7767 -- package is also in use (the flags on both entities must
7768 -- remain consistent, and a subsequent use of either of them
7769 -- should be recognized as redundant).
7771 if Present (Renamed_Object (P)) then
7772 Set_In_Use (Renamed_Object (P));
7773 Set_Current_Use_Clause (Renamed_Object (P), N);
7774 Real_P := Renamed_Object (P);
7779 -- Ada 2005 (AI-262): Check the use_clause of a private withed package
7780 -- found in the private part of a package specification
7782 if In_Private_Part (Current_Scope)
7783 and then Has_Private_With (P)
7784 and then Is_Child_Unit (Current_Scope)
7785 and then Is_Child_Unit (P)
7786 and then Is_Ancestor_Package (Scope (Current_Scope), P)
7788 Private_With_OK := True;
7791 -- Loop through entities in one package making them potentially
7794 Id := First_Entity (P);
7796 and then (Id /= First_Private_Entity (P)
7797 or else Private_With_OK) -- Ada 2005 (AI-262)
7799 Prev := Current_Entity (Id);
7800 while Present (Prev) loop
7801 if Is_Immediately_Visible (Prev)
7802 and then (not Is_Overloadable (Prev)
7803 or else not Is_Overloadable (Id)
7804 or else (Type_Conformant (Id, Prev)))
7806 if No (Current_Instance) then
7808 -- Potentially use-visible entity remains hidden
7810 goto Next_Usable_Entity;
7812 -- A use clause within an instance hides outer global entities,
7813 -- which are not used to resolve local entities in the
7814 -- instance. Note that the predefined entities in Standard
7815 -- could not have been hidden in the generic by a use clause,
7816 -- and therefore remain visible. Other compilation units whose
7817 -- entities appear in Standard must be hidden in an instance.
7819 -- To determine whether an entity is external to the instance
7820 -- we compare the scope depth of its scope with that of the
7821 -- current instance. However, a generic actual of a subprogram
7822 -- instance is declared in the wrapper package but will not be
7823 -- hidden by a use-visible entity. similarly, an entity that is
7824 -- declared in an enclosing instance will not be hidden by an
7825 -- an entity declared in a generic actual, which can only have
7826 -- been use-visible in the generic and will not have hidden the
7827 -- entity in the generic parent.
7829 -- If Id is called Standard, the predefined package with the
7830 -- same name is in the homonym chain. It has to be ignored
7831 -- because it has no defined scope (being the only entity in
7832 -- the system with this mandated behavior).
7834 elsif not Is_Hidden (Id)
7835 and then Present (Scope (Prev))
7836 and then not Is_Wrapper_Package (Scope (Prev))
7837 and then Scope_Depth (Scope (Prev)) <
7838 Scope_Depth (Current_Instance)
7839 and then (Scope (Prev) /= Standard_Standard
7840 or else Sloc (Prev) > Standard_Location)
7842 if In_Open_Scopes (Scope (Prev))
7843 and then Is_Generic_Instance (Scope (Prev))
7844 and then Present (Associated_Formal_Package (P))
7849 Set_Is_Potentially_Use_Visible (Id);
7850 Set_Is_Immediately_Visible (Prev, False);
7851 Append_Elmt (Prev, Hidden_By_Use_Clause (N));
7855 -- A user-defined operator is not use-visible if the predefined
7856 -- operator for the type is immediately visible, which is the case
7857 -- if the type of the operand is in an open scope. This does not
7858 -- apply to user-defined operators that have operands of different
7859 -- types, because the predefined mixed mode operations (multiply
7860 -- and divide) apply to universal types and do not hide anything.
7862 elsif Ekind (Prev) = E_Operator
7863 and then Operator_Matches_Spec (Prev, Id)
7864 and then In_Open_Scopes
7865 (Scope (Base_Type (Etype (First_Formal (Id)))))
7866 and then (No (Next_Formal (First_Formal (Id)))
7867 or else Etype (First_Formal (Id))
7868 = Etype (Next_Formal (First_Formal (Id)))
7869 or else Chars (Prev) = Name_Op_Expon)
7871 goto Next_Usable_Entity;
7873 -- In an instance, two homonyms may become use_visible through the
7874 -- actuals of distinct formal packages. In the generic, only the
7875 -- current one would have been visible, so make the other one
7878 elsif Present (Current_Instance)
7879 and then Is_Potentially_Use_Visible (Prev)
7880 and then not Is_Overloadable (Prev)
7881 and then Scope (Id) /= Scope (Prev)
7882 and then Used_As_Generic_Actual (Scope (Prev))
7883 and then Used_As_Generic_Actual (Scope (Id))
7884 and then not In_Same_List (Current_Use_Clause (Scope (Prev)),
7885 Current_Use_Clause (Scope (Id)))
7887 Set_Is_Potentially_Use_Visible (Prev, False);
7888 Append_Elmt (Prev, Hidden_By_Use_Clause (N));
7891 Prev := Homonym (Prev);
7894 -- On exit, we know entity is not hidden, unless it is private
7896 if not Is_Hidden (Id)
7897 and then ((not Is_Child_Unit (Id))
7898 or else Is_Visible_Child_Unit (Id))
7900 Set_Is_Potentially_Use_Visible (Id);
7902 if Is_Private_Type (Id)
7903 and then Present (Full_View (Id))
7905 Set_Is_Potentially_Use_Visible (Full_View (Id));
7909 <<Next_Usable_Entity>>
7913 -- Child units are also made use-visible by a use clause, but they may
7914 -- appear after all visible declarations in the parent entity list.
7916 while Present (Id) loop
7917 if Is_Child_Unit (Id)
7918 and then Is_Visible_Child_Unit (Id)
7920 Set_Is_Potentially_Use_Visible (Id);
7926 if Chars (Real_P) = Name_System
7927 and then Scope (Real_P) = Standard_Standard
7928 and then Present_System_Aux (N)
7930 Use_One_Package (System_Aux_Id, N);
7933 end Use_One_Package;
7939 procedure Use_One_Type (Id : Node_Id; Installed : Boolean := False) is
7941 Is_Known_Used : Boolean;
7945 function Spec_Reloaded_For_Body return Boolean;
7946 -- Determine whether the compilation unit is a package body and the use
7947 -- type clause is in the spec of the same package. Even though the spec
7948 -- was analyzed first, its context is reloaded when analysing the body.
7950 procedure Use_Class_Wide_Operations (Typ : Entity_Id);
7951 -- AI05-150: if the use_type_clause carries the "all" qualifier,
7952 -- class-wide operations of ancestor types are use-visible if the
7953 -- ancestor type is visible.
7955 ----------------------------
7956 -- Spec_Reloaded_For_Body --
7957 ----------------------------
7959 function Spec_Reloaded_For_Body return Boolean is
7961 if Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Body then
7963 Spec : constant Node_Id :=
7964 Parent (List_Containing (Parent (Id)));
7967 Nkind (Spec) = N_Package_Specification
7968 and then Corresponding_Body (Parent (Spec)) =
7969 Cunit_Entity (Current_Sem_Unit);
7974 end Spec_Reloaded_For_Body;
7976 -------------------------------
7977 -- Use_Class_Wide_Operations --
7978 -------------------------------
7980 procedure Use_Class_Wide_Operations (Typ : Entity_Id) is
7984 function Is_Class_Wide_Operation_Of
7986 T : Entity_Id) return Boolean;
7987 -- Determine whether a subprogram has a class-wide parameter or
7988 -- result that is T'Class.
7990 ---------------------------------
7991 -- Is_Class_Wide_Operation_Of --
7992 ---------------------------------
7994 function Is_Class_Wide_Operation_Of
7996 T : Entity_Id) return Boolean
8001 Formal := First_Formal (Op);
8002 while Present (Formal) loop
8003 if Etype (Formal) = Class_Wide_Type (T) then
8006 Next_Formal (Formal);
8009 if Etype (Op) = Class_Wide_Type (T) then
8014 end Is_Class_Wide_Operation_Of;
8016 -- Start of processing for Use_Class_Wide_Operations
8019 Scop := Scope (Typ);
8020 if not Is_Hidden (Scop) then
8021 Ent := First_Entity (Scop);
8022 while Present (Ent) loop
8023 if Is_Overloadable (Ent)
8024 and then Is_Class_Wide_Operation_Of (Ent, Typ)
8025 and then not Is_Potentially_Use_Visible (Ent)
8027 Set_Is_Potentially_Use_Visible (Ent);
8028 Append_Elmt (Ent, Used_Operations (Parent (Id)));
8035 if Is_Derived_Type (Typ) then
8036 Use_Class_Wide_Operations (Etype (Base_Type (Typ)));
8038 end Use_Class_Wide_Operations;
8040 -- Start of processing for Use_One_Type
8043 -- It is the type determined by the subtype mark (8.4(8)) whose
8044 -- operations become potentially use-visible.
8046 T := Base_Type (Entity (Id));
8048 -- Either the type itself is used, the package where it is declared
8049 -- is in use or the entity is declared in the current package, thus
8054 or else In_Use (Scope (T))
8055 or else Scope (T) = Current_Scope;
8057 Set_Redundant_Use (Id,
8058 Is_Known_Used or else Is_Potentially_Use_Visible (T));
8060 if Ekind (T) = E_Incomplete_Type then
8061 Error_Msg_N ("premature usage of incomplete type", Id);
8063 elsif In_Open_Scopes (Scope (T)) then
8066 -- A limited view cannot appear in a use_type clause. However, an access
8067 -- type whose designated type is limited has the flag but is not itself
8068 -- a limited view unless we only have a limited view of its enclosing
8071 elsif From_With_Type (T)
8072 and then From_With_Type (Scope (T))
8075 ("incomplete type from limited view "
8076 & "cannot appear in use clause", Id);
8078 -- If the subtype mark designates a subtype in a different package,
8079 -- we have to check that the parent type is visible, otherwise the
8080 -- use type clause is a noop. Not clear how to do that???
8082 elsif not Redundant_Use (Id) then
8085 -- If T is tagged, primitive operators on class-wide operands
8086 -- are also available.
8088 if Is_Tagged_Type (T) then
8089 Set_In_Use (Class_Wide_Type (T));
8092 Set_Current_Use_Clause (T, Parent (Id));
8094 -- Iterate over primitive operations of the type. If an operation is
8095 -- already use_visible, it is the result of a previous use_clause,
8096 -- and already appears on the corresponding entity chain. If the
8097 -- clause is being reinstalled, operations are already use-visible.
8103 Op_List := Collect_Primitive_Operations (T);
8104 Elmt := First_Elmt (Op_List);
8105 while Present (Elmt) loop
8106 if (Nkind (Node (Elmt)) = N_Defining_Operator_Symbol
8107 or else Chars (Node (Elmt)) in Any_Operator_Name)
8108 and then not Is_Hidden (Node (Elmt))
8109 and then not Is_Potentially_Use_Visible (Node (Elmt))
8111 Set_Is_Potentially_Use_Visible (Node (Elmt));
8112 Append_Elmt (Node (Elmt), Used_Operations (Parent (Id)));
8114 elsif Ada_Version >= Ada_2012
8115 and then All_Present (Parent (Id))
8116 and then not Is_Hidden (Node (Elmt))
8117 and then not Is_Potentially_Use_Visible (Node (Elmt))
8119 Set_Is_Potentially_Use_Visible (Node (Elmt));
8120 Append_Elmt (Node (Elmt), Used_Operations (Parent (Id)));
8127 if Ada_Version >= Ada_2012
8128 and then All_Present (Parent (Id))
8129 and then Is_Tagged_Type (T)
8131 Use_Class_Wide_Operations (T);
8135 -- If warning on redundant constructs, check for unnecessary WITH
8137 if Warn_On_Redundant_Constructs
8138 and then Is_Known_Used
8140 -- with P; with P; use P;
8141 -- package P is package X is package body X is
8142 -- type T ... use P.T;
8144 -- The compilation unit is the body of X. GNAT first compiles the
8145 -- spec of X, then proceeds to the body. At that point P is marked
8146 -- as use visible. The analysis then reinstalls the spec along with
8147 -- its context. The use clause P.T is now recognized as redundant,
8148 -- but in the wrong context. Do not emit a warning in such cases.
8149 -- Do not emit a warning either if we are in an instance, there is
8150 -- no redundancy between an outer use_clause and one that appears
8151 -- within the generic.
8153 and then not Spec_Reloaded_For_Body
8154 and then not In_Instance
8156 -- The type already has a use clause
8160 -- Case where we know the current use clause for the type
8162 if Present (Current_Use_Clause (T)) then
8163 Use_Clause_Known : declare
8164 Clause1 : constant Node_Id := Parent (Id);
8165 Clause2 : constant Node_Id := Current_Use_Clause (T);
8172 function Entity_Of_Unit (U : Node_Id) return Entity_Id;
8173 -- Return the appropriate entity for determining which unit
8174 -- has a deeper scope: the defining entity for U, unless U
8175 -- is a package instance, in which case we retrieve the
8176 -- entity of the instance spec.
8178 --------------------
8179 -- Entity_Of_Unit --
8180 --------------------
8182 function Entity_Of_Unit (U : Node_Id) return Entity_Id is
8184 if Nkind (U) = N_Package_Instantiation
8185 and then Analyzed (U)
8187 return Defining_Entity (Instance_Spec (U));
8189 return Defining_Entity (U);
8193 -- Start of processing for Use_Clause_Known
8196 -- If both current use type clause and the use type clause
8197 -- for the type are at the compilation unit level, one of
8198 -- the units must be an ancestor of the other, and the
8199 -- warning belongs on the descendant.
8201 if Nkind (Parent (Clause1)) = N_Compilation_Unit
8203 Nkind (Parent (Clause2)) = N_Compilation_Unit
8206 -- If the unit is a subprogram body that acts as spec,
8207 -- the context clause is shared with the constructed
8208 -- subprogram spec. Clearly there is no redundancy.
8210 if Clause1 = Clause2 then
8214 Unit1 := Unit (Parent (Clause1));
8215 Unit2 := Unit (Parent (Clause2));
8217 -- If both clauses are on same unit, or one is the body
8218 -- of the other, or one of them is in a subunit, report
8219 -- redundancy on the later one.
8221 if Unit1 = Unit2 then
8222 Error_Msg_Sloc := Sloc (Current_Use_Clause (T));
8223 Error_Msg_NE -- CODEFIX
8224 ("& is already use-visible through previous "
8225 & "use_type_clause #?", Clause1, T);
8228 elsif Nkind (Unit1) = N_Subunit then
8229 Error_Msg_Sloc := Sloc (Current_Use_Clause (T));
8230 Error_Msg_NE -- CODEFIX
8231 ("& is already use-visible through previous "
8232 & "use_type_clause #?", Clause1, T);
8235 elsif Nkind_In (Unit2, N_Package_Body, N_Subprogram_Body)
8236 and then Nkind (Unit1) /= Nkind (Unit2)
8237 and then Nkind (Unit1) /= N_Subunit
8239 Error_Msg_Sloc := Sloc (Clause1);
8240 Error_Msg_NE -- CODEFIX
8241 ("& is already use-visible through previous "
8242 & "use_type_clause #?", Current_Use_Clause (T), T);
8246 -- There is a redundant use type clause in a child unit.
8247 -- Determine which of the units is more deeply nested.
8248 -- If a unit is a package instance, retrieve the entity
8249 -- and its scope from the instance spec.
8251 Ent1 := Entity_Of_Unit (Unit1);
8252 Ent2 := Entity_Of_Unit (Unit2);
8254 if Scope (Ent2) = Standard_Standard then
8255 Error_Msg_Sloc := Sloc (Current_Use_Clause (T));
8258 elsif Scope (Ent1) = Standard_Standard then
8259 Error_Msg_Sloc := Sloc (Id);
8262 -- If both units are child units, we determine which one
8263 -- is the descendant by the scope distance to the
8264 -- ultimate parent unit.
8274 and then Present (S2)
8275 and then S1 /= Standard_Standard
8276 and then S2 /= Standard_Standard
8282 if S1 = Standard_Standard then
8283 Error_Msg_Sloc := Sloc (Id);
8286 Error_Msg_Sloc := Sloc (Current_Use_Clause (T));
8292 Error_Msg_NE -- CODEFIX
8293 ("& is already use-visible through previous "
8294 & "use_type_clause #?", Err_No, Id);
8296 -- Case where current use type clause and the use type
8297 -- clause for the type are not both at the compilation unit
8298 -- level. In this case we don't have location information.
8301 Error_Msg_NE -- CODEFIX
8302 ("& is already use-visible through previous "
8303 & "use type clause?", Id, T);
8305 end Use_Clause_Known;
8307 -- Here if Current_Use_Clause is not set for T, another case
8308 -- where we do not have the location information available.
8311 Error_Msg_NE -- CODEFIX
8312 ("& is already use-visible through previous "
8313 & "use type clause?", Id, T);
8316 -- The package where T is declared is already used
8318 elsif In_Use (Scope (T)) then
8319 Error_Msg_Sloc := Sloc (Current_Use_Clause (Scope (T)));
8320 Error_Msg_NE -- CODEFIX
8321 ("& is already use-visible through package use clause #?",
8324 -- The current scope is the package where T is declared
8327 Error_Msg_Node_2 := Scope (T);
8328 Error_Msg_NE -- CODEFIX
8329 ("& is already use-visible inside package &?", Id, T);
8338 procedure Write_Info is
8339 Id : Entity_Id := First_Entity (Current_Scope);
8342 -- No point in dumping standard entities
8344 if Current_Scope = Standard_Standard then
8348 Write_Str ("========================================================");
8350 Write_Str (" Defined Entities in ");
8351 Write_Name (Chars (Current_Scope));
8353 Write_Str ("========================================================");
8357 Write_Str ("-- none --");
8361 while Present (Id) loop
8362 Write_Entity_Info (Id, " ");
8367 if Scope (Current_Scope) = Standard_Standard then
8369 -- Print information on the current unit itself
8371 Write_Entity_Info (Current_Scope, " ");
8384 for J in reverse 1 .. Scope_Stack.Last loop
8385 S := Scope_Stack.Table (J).Entity;
8386 Write_Int (Int (S));
8387 Write_Str (" === ");
8388 Write_Name (Chars (S));
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