1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2011, Free Software Foundation, Inc. --
11 -- GNAT is free software; you can redistribute it and/or modify it under --
12 -- terms of the GNU General Public License as published by the Free Soft- --
13 -- ware Foundation; either version 3, or (at your option) any later ver- --
14 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
15 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
16 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
17 -- for more details. You should have received a copy of the GNU General --
18 -- Public License distributed with GNAT; see file COPYING3. If not, go to --
19 -- http://www.gnu.org/licenses for a complete copy of the license. --
21 -- GNAT was originally developed by the GNAT team at New York University. --
22 -- Extensive contributions were provided by Ada Core Technologies Inc. --
24 ------------------------------------------------------------------------------
26 with Atree; use Atree;
27 with Debug; use Debug;
28 with Einfo; use Einfo;
29 with Elists; use Elists;
30 with Errout; use Errout;
31 with Exp_Tss; use Exp_Tss;
32 with Exp_Util; use Exp_Util;
33 with Fname; use Fname;
34 with Freeze; use Freeze;
35 with Impunit; use Impunit;
37 with Lib.Load; use Lib.Load;
38 with Lib.Xref; use Lib.Xref;
39 with Namet; use Namet;
40 with Namet.Sp; use Namet.Sp;
41 with Nlists; use Nlists;
42 with Nmake; use Nmake;
44 with Output; use Output;
45 with Restrict; use Restrict;
46 with Rident; use Rident;
47 with Rtsfind; use Rtsfind;
49 with Sem_Aux; use Sem_Aux;
50 with Sem_Cat; use Sem_Cat;
51 with Sem_Ch3; use Sem_Ch3;
52 with Sem_Ch4; use Sem_Ch4;
53 with Sem_Ch6; use Sem_Ch6;
54 with Sem_Ch12; use Sem_Ch12;
55 with Sem_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
2667 or else (Nkind (Nam) /= N_Expanded_Name
2668 and then Chars (Old_S) = Chars (New_S)))
2670 Error_Msg_N ("subprogram cannot rename itself", N);
2673 Set_Convention (New_S, Convention (Old_S));
2675 if Is_Abstract_Subprogram (Old_S) then
2676 if Present (Rename_Spec) then
2678 ("a renaming-as-body cannot rename an abstract subprogram",
2680 Set_Has_Completion (Rename_Spec);
2682 Set_Is_Abstract_Subprogram (New_S);
2686 Check_Library_Unit_Renaming (N, Old_S);
2688 -- Pathological case: procedure renames entry in the scope of its
2689 -- task. Entry is given by simple name, but body must be built for
2690 -- procedure. Of course if called it will deadlock.
2692 if Ekind (Old_S) = E_Entry then
2693 Set_Has_Completion (New_S, False);
2694 Set_Alias (New_S, Empty);
2698 Freeze_Before (N, Old_S);
2699 Set_Has_Delayed_Freeze (New_S, False);
2700 Freeze_Before (N, New_S);
2702 -- An abstract subprogram is only allowed as an actual in the case
2703 -- where the formal subprogram is also abstract.
2705 if (Ekind (Old_S) = E_Procedure or else Ekind (Old_S) = E_Function)
2706 and then Is_Abstract_Subprogram (Old_S)
2707 and then not Is_Abstract_Subprogram (Formal_Spec)
2710 ("abstract subprogram not allowed as generic actual", Nam);
2715 -- A common error is to assume that implicit operators for types are
2716 -- defined in Standard, or in the scope of a subtype. In those cases
2717 -- where the renamed entity is given with an expanded name, it is
2718 -- worth mentioning that operators for the type are not declared in
2719 -- the scope given by the prefix.
2721 if Nkind (Nam) = N_Expanded_Name
2722 and then Nkind (Selector_Name (Nam)) = N_Operator_Symbol
2723 and then Scope (Entity (Nam)) = Standard_Standard
2726 T : constant Entity_Id :=
2727 Base_Type (Etype (First_Formal (New_S)));
2729 Error_Msg_Node_2 := Prefix (Nam);
2731 ("operator for type& is not declared in&", Prefix (Nam), T);
2736 ("no visible subprogram matches the specification for&",
2740 if Present (Candidate_Renaming) then
2747 F1 := First_Formal (Candidate_Renaming);
2748 F2 := First_Formal (New_S);
2749 T1 := First_Subtype (Etype (F1));
2751 while Present (F1) and then Present (F2) loop
2756 if Present (F1) and then Present (Default_Value (F1)) then
2757 if Present (Next_Formal (F1)) then
2759 ("\missing specification for &" &
2760 " and other formals with defaults", Spec, F1);
2763 ("\missing specification for &", Spec, F1);
2767 if Nkind (Nam) = N_Operator_Symbol
2768 and then From_Default (N)
2770 Error_Msg_Node_2 := T1;
2772 ("default & on & is not directly visible",
2779 -- Ada 2005 AI 404: if the new subprogram is dispatching, verify that
2780 -- controlling access parameters are known non-null for the renamed
2781 -- subprogram. Test also applies to a subprogram instantiation that
2782 -- is dispatching. Test is skipped if some previous error was detected
2783 -- that set Old_S to Any_Id.
2785 if Ada_Version >= Ada_2005
2786 and then Old_S /= Any_Id
2787 and then not Is_Dispatching_Operation (Old_S)
2788 and then Is_Dispatching_Operation (New_S)
2795 Old_F := First_Formal (Old_S);
2796 New_F := First_Formal (New_S);
2797 while Present (Old_F) loop
2798 if Ekind (Etype (Old_F)) = E_Anonymous_Access_Type
2799 and then Is_Controlling_Formal (New_F)
2800 and then not Can_Never_Be_Null (Old_F)
2802 Error_Msg_N ("access parameter is controlling,", New_F);
2804 ("\corresponding parameter of& "
2805 & "must be explicitly null excluding", New_F, Old_S);
2808 Next_Formal (Old_F);
2809 Next_Formal (New_F);
2814 -- A useful warning, suggested by Ada Bug Finder (Ada-Europe 2005)
2815 -- is to warn if an operator is being renamed as a different operator.
2816 -- If the operator is predefined, examine the kind of the entity, not
2817 -- the abbreviated declaration in Standard.
2819 if Comes_From_Source (N)
2820 and then Present (Old_S)
2822 (Nkind (Old_S) = N_Defining_Operator_Symbol
2823 or else Ekind (Old_S) = E_Operator)
2824 and then Nkind (New_S) = N_Defining_Operator_Symbol
2825 and then Chars (Old_S) /= Chars (New_S)
2828 ("?& is being renamed as a different operator", N, Old_S);
2831 -- Check for renaming of obsolescent subprogram
2833 Check_Obsolescent_2005_Entity (Entity (Nam), Nam);
2835 -- Another warning or some utility: if the new subprogram as the same
2836 -- name as the old one, the old one is not hidden by an outer homograph,
2837 -- the new one is not a public symbol, and the old one is otherwise
2838 -- directly visible, the renaming is superfluous.
2840 if Chars (Old_S) = Chars (New_S)
2841 and then Comes_From_Source (N)
2842 and then Scope (Old_S) /= Standard_Standard
2843 and then Warn_On_Redundant_Constructs
2845 (Is_Immediately_Visible (Old_S)
2846 or else Is_Potentially_Use_Visible (Old_S))
2847 and then Is_Overloadable (Current_Scope)
2848 and then Chars (Current_Scope) /= Chars (Old_S)
2851 ("?redundant renaming, entity is directly visible", Name (N));
2854 -- Implementation-defined aspect specifications can appear in a renaming
2855 -- declaration, but not language-defined ones. The call to procedure
2856 -- Analyze_Aspect_Specifications will take care of this error check.
2858 if Has_Aspects (N) then
2859 Analyze_Aspect_Specifications (N, New_S);
2862 Ada_Version := Save_AV;
2863 Ada_Version_Explicit := Save_AV_Exp;
2864 end Analyze_Subprogram_Renaming;
2866 -------------------------
2867 -- Analyze_Use_Package --
2868 -------------------------
2870 -- Resolve the package names in the use clause, and make all the visible
2871 -- entities defined in the package potentially use-visible. If the package
2872 -- is already in use from a previous use clause, its visible entities are
2873 -- already use-visible. In that case, mark the occurrence as a redundant
2874 -- use. If the package is an open scope, i.e. if the use clause occurs
2875 -- within the package itself, ignore it.
2877 procedure Analyze_Use_Package (N : Node_Id) is
2878 Pack_Name : Node_Id;
2881 -- Start of processing for Analyze_Use_Package
2884 Check_SPARK_Restriction ("use clause is not allowed", N);
2886 Set_Hidden_By_Use_Clause (N, No_Elist);
2888 -- Use clause not allowed in a spec of a predefined package declaration
2889 -- except that packages whose file name starts a-n are OK (these are
2890 -- children of Ada.Numerics, which are never loaded by Rtsfind).
2892 if Is_Predefined_File_Name (Unit_File_Name (Current_Sem_Unit))
2893 and then Name_Buffer (1 .. 3) /= "a-n"
2895 Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Declaration
2897 Error_Msg_N ("use clause not allowed in predefined spec", N);
2900 -- Chain clause to list of use clauses in current scope
2902 if Nkind (Parent (N)) /= N_Compilation_Unit then
2903 Chain_Use_Clause (N);
2906 -- Loop through package names to identify referenced packages
2908 Pack_Name := First (Names (N));
2909 while Present (Pack_Name) loop
2910 Analyze (Pack_Name);
2912 if Nkind (Parent (N)) = N_Compilation_Unit
2913 and then Nkind (Pack_Name) = N_Expanded_Name
2919 Pref := Prefix (Pack_Name);
2920 while Nkind (Pref) = N_Expanded_Name loop
2921 Pref := Prefix (Pref);
2924 if Entity (Pref) = Standard_Standard then
2926 ("predefined package Standard cannot appear"
2927 & " in a context clause", Pref);
2935 -- Loop through package names to mark all entities as potentially
2938 Pack_Name := First (Names (N));
2939 while Present (Pack_Name) loop
2940 if Is_Entity_Name (Pack_Name) then
2941 Pack := Entity (Pack_Name);
2943 if Ekind (Pack) /= E_Package
2944 and then Etype (Pack) /= Any_Type
2946 if Ekind (Pack) = E_Generic_Package then
2947 Error_Msg_N -- CODEFIX
2948 ("a generic package is not allowed in a use clause",
2951 Error_Msg_N ("& is not a usable package", Pack_Name);
2955 if Nkind (Parent (N)) = N_Compilation_Unit then
2956 Check_In_Previous_With_Clause (N, Pack_Name);
2959 if Applicable_Use (Pack_Name) then
2960 Use_One_Package (Pack, N);
2964 -- Report error because name denotes something other than a package
2967 Error_Msg_N ("& is not a package", Pack_Name);
2972 end Analyze_Use_Package;
2974 ----------------------
2975 -- Analyze_Use_Type --
2976 ----------------------
2978 procedure Analyze_Use_Type (N : Node_Id) is
2983 Set_Hidden_By_Use_Clause (N, No_Elist);
2985 -- Chain clause to list of use clauses in current scope
2987 if Nkind (Parent (N)) /= N_Compilation_Unit then
2988 Chain_Use_Clause (N);
2991 -- If the Used_Operations list is already initialized, the clause has
2992 -- been analyzed previously, and it is begin reinstalled, for example
2993 -- when the clause appears in a package spec and we are compiling the
2994 -- corresponding package body. In that case, make the entities on the
2995 -- existing list use_visible, and mark the corresponding types In_Use.
2997 if Present (Used_Operations (N)) then
3003 Mark := First (Subtype_Marks (N));
3004 while Present (Mark) loop
3005 Use_One_Type (Mark, Installed => True);
3009 Elmt := First_Elmt (Used_Operations (N));
3010 while Present (Elmt) loop
3011 Set_Is_Potentially_Use_Visible (Node (Elmt));
3019 -- Otherwise, create new list and attach to it the operations that
3020 -- are made use-visible by the clause.
3022 Set_Used_Operations (N, New_Elmt_List);
3023 Id := First (Subtype_Marks (N));
3024 while Present (Id) loop
3028 if E /= Any_Type then
3031 if Nkind (Parent (N)) = N_Compilation_Unit then
3032 if Nkind (Id) = N_Identifier then
3033 Error_Msg_N ("type is not directly visible", Id);
3035 elsif Is_Child_Unit (Scope (E))
3036 and then Scope (E) /= System_Aux_Id
3038 Check_In_Previous_With_Clause (N, Prefix (Id));
3043 -- If the use_type_clause appears in a compilation unit context,
3044 -- check whether it comes from a unit that may appear in a
3045 -- limited_with_clause, for a better error message.
3047 if Nkind (Parent (N)) = N_Compilation_Unit
3048 and then Nkind (Id) /= N_Identifier
3054 function Mentioned (Nam : Node_Id) return Boolean;
3055 -- Check whether the prefix of expanded name for the type
3056 -- appears in the prefix of some limited_with_clause.
3062 function Mentioned (Nam : Node_Id) return Boolean is
3064 return Nkind (Name (Item)) = N_Selected_Component
3066 Chars (Prefix (Name (Item))) = Chars (Nam);
3070 Pref := Prefix (Id);
3071 Item := First (Context_Items (Parent (N)));
3073 while Present (Item) and then Item /= N loop
3074 if Nkind (Item) = N_With_Clause
3075 and then Limited_Present (Item)
3076 and then Mentioned (Pref)
3079 (Get_Msg_Id, "premature usage of incomplete type");
3090 end Analyze_Use_Type;
3092 --------------------
3093 -- Applicable_Use --
3094 --------------------
3096 function Applicable_Use (Pack_Name : Node_Id) return Boolean is
3097 Pack : constant Entity_Id := Entity (Pack_Name);
3100 if In_Open_Scopes (Pack) then
3101 if Warn_On_Redundant_Constructs
3102 and then Pack = Current_Scope
3104 Error_Msg_NE -- CODEFIX
3105 ("& is already use-visible within itself?", Pack_Name, Pack);
3110 elsif In_Use (Pack) then
3111 Note_Redundant_Use (Pack_Name);
3114 elsif Present (Renamed_Object (Pack))
3115 and then In_Use (Renamed_Object (Pack))
3117 Note_Redundant_Use (Pack_Name);
3125 ------------------------
3126 -- Attribute_Renaming --
3127 ------------------------
3129 procedure Attribute_Renaming (N : Node_Id) is
3130 Loc : constant Source_Ptr := Sloc (N);
3131 Nam : constant Node_Id := Name (N);
3132 Spec : constant Node_Id := Specification (N);
3133 New_S : constant Entity_Id := Defining_Unit_Name (Spec);
3134 Aname : constant Name_Id := Attribute_Name (Nam);
3136 Form_Num : Nat := 0;
3137 Expr_List : List_Id := No_List;
3139 Attr_Node : Node_Id;
3140 Body_Node : Node_Id;
3141 Param_Spec : Node_Id;
3144 Generate_Definition (New_S);
3146 -- This procedure is called in the context of subprogram renaming, and
3147 -- thus the attribute must be one that is a subprogram. All of those
3148 -- have at least one formal parameter, with the singular exception of
3149 -- AST_Entry (which is a real oddity, it is odd that this can be renamed
3152 if not Is_Non_Empty_List (Parameter_Specifications (Spec)) then
3153 if Aname /= Name_AST_Entry then
3155 ("subprogram renaming an attribute must have formals", N);
3160 Param_Spec := First (Parameter_Specifications (Spec));
3161 while Present (Param_Spec) loop
3162 Form_Num := Form_Num + 1;
3164 if Nkind (Parameter_Type (Param_Spec)) /= N_Access_Definition then
3165 Find_Type (Parameter_Type (Param_Spec));
3167 -- The profile of the new entity denotes the base type (s) of
3168 -- the types given in the specification. For access parameters
3169 -- there are no subtypes involved.
3171 Rewrite (Parameter_Type (Param_Spec),
3173 (Base_Type (Entity (Parameter_Type (Param_Spec))), Loc));
3176 if No (Expr_List) then
3177 Expr_List := New_List;
3180 Append_To (Expr_List,
3181 Make_Identifier (Loc,
3182 Chars => Chars (Defining_Identifier (Param_Spec))));
3184 -- The expressions in the attribute reference are not freeze
3185 -- points. Neither is the attribute as a whole, see below.
3187 Set_Must_Not_Freeze (Last (Expr_List));
3192 -- Immediate error if too many formals. Other mismatches in number or
3193 -- types of parameters are detected when we analyze the body of the
3194 -- subprogram that we construct.
3196 if Form_Num > 2 then
3197 Error_Msg_N ("too many formals for attribute", N);
3199 -- Error if the attribute reference has expressions that look like
3200 -- formal parameters.
3202 elsif Present (Expressions (Nam)) then
3203 Error_Msg_N ("illegal expressions in attribute reference", Nam);
3206 Aname = Name_Compose or else
3207 Aname = Name_Exponent or else
3208 Aname = Name_Leading_Part or else
3209 Aname = Name_Pos or else
3210 Aname = Name_Round or else
3211 Aname = Name_Scaling or else
3214 if Nkind (N) = N_Subprogram_Renaming_Declaration
3215 and then Present (Corresponding_Formal_Spec (N))
3218 ("generic actual cannot be attribute involving universal type",
3222 ("attribute involving a universal type cannot be renamed",
3227 -- AST_Entry is an odd case. It doesn't really make much sense to allow
3228 -- it to be renamed, but that's the DEC rule, so we have to do it right.
3229 -- The point is that the AST_Entry call should be made now, and what the
3230 -- function will return is the returned value.
3232 -- Note that there is no Expr_List in this case anyway
3234 if Aname = Name_AST_Entry then
3236 Ent : constant Entity_Id := Make_Temporary (Loc, 'R', Nam);
3241 Make_Object_Declaration (Loc,
3242 Defining_Identifier => Ent,
3243 Object_Definition =>
3244 New_Occurrence_Of (RTE (RE_AST_Handler), Loc),
3246 Constant_Present => True);
3248 Set_Assignment_OK (Decl, True);
3249 Insert_Action (N, Decl);
3250 Attr_Node := Make_Identifier (Loc, Chars (Ent));
3253 -- For all other attributes, we rewrite the attribute node to have
3254 -- a list of expressions corresponding to the subprogram formals.
3255 -- A renaming declaration is not a freeze point, and the analysis of
3256 -- the attribute reference should not freeze the type of the prefix.
3260 Make_Attribute_Reference (Loc,
3261 Prefix => Prefix (Nam),
3262 Attribute_Name => Aname,
3263 Expressions => Expr_List);
3265 Set_Must_Not_Freeze (Attr_Node);
3266 Set_Must_Not_Freeze (Prefix (Nam));
3269 -- Case of renaming a function
3271 if Nkind (Spec) = N_Function_Specification then
3272 if Is_Procedure_Attribute_Name (Aname) then
3273 Error_Msg_N ("attribute can only be renamed as procedure", Nam);
3277 Find_Type (Result_Definition (Spec));
3278 Rewrite (Result_Definition (Spec),
3280 Base_Type (Entity (Result_Definition (Spec))), Loc));
3283 Make_Subprogram_Body (Loc,
3284 Specification => Spec,
3285 Declarations => New_List,
3286 Handled_Statement_Sequence =>
3287 Make_Handled_Sequence_Of_Statements (Loc,
3288 Statements => New_List (
3289 Make_Simple_Return_Statement (Loc,
3290 Expression => Attr_Node))));
3292 -- Case of renaming a procedure
3295 if not Is_Procedure_Attribute_Name (Aname) then
3296 Error_Msg_N ("attribute can only be renamed as function", Nam);
3301 Make_Subprogram_Body (Loc,
3302 Specification => Spec,
3303 Declarations => New_List,
3304 Handled_Statement_Sequence =>
3305 Make_Handled_Sequence_Of_Statements (Loc,
3306 Statements => New_List (Attr_Node)));
3309 -- In case of tagged types we add the body of the generated function to
3310 -- the freezing actions of the type (because in the general case such
3311 -- type is still not frozen). We exclude from this processing generic
3312 -- formal subprograms found in instantiations and AST_Entry renamings.
3314 -- We must exclude VM targets and restricted run-time libraries because
3315 -- entity AST_Handler is defined in package System.Aux_Dec which is not
3316 -- available in those platforms. Note that we cannot use the function
3317 -- Restricted_Profile (instead of Configurable_Run_Time_Mode) because
3318 -- the ZFP run-time library is not defined as a profile, and we do not
3319 -- want to deal with AST_Handler in ZFP mode.
3321 if VM_Target = No_VM
3322 and then not Configurable_Run_Time_Mode
3323 and then not Present (Corresponding_Formal_Spec (N))
3324 and then Etype (Nam) /= RTE (RE_AST_Handler)
3327 P : constant Entity_Id := Prefix (Nam);
3332 if Is_Tagged_Type (Etype (P)) then
3333 Ensure_Freeze_Node (Etype (P));
3334 Append_Freeze_Action (Etype (P), Body_Node);
3336 Rewrite (N, Body_Node);
3338 Set_Etype (New_S, Base_Type (Etype (New_S)));
3342 -- Generic formal subprograms or AST_Handler renaming
3345 Rewrite (N, Body_Node);
3347 Set_Etype (New_S, Base_Type (Etype (New_S)));
3350 if Is_Compilation_Unit (New_S) then
3352 ("a library unit can only rename another library unit", N);
3355 -- We suppress elaboration warnings for the resulting entity, since
3356 -- clearly they are not needed, and more particularly, in the case
3357 -- of a generic formal subprogram, the resulting entity can appear
3358 -- after the instantiation itself, and thus look like a bogus case
3359 -- of access before elaboration.
3361 Set_Suppress_Elaboration_Warnings (New_S);
3363 end Attribute_Renaming;
3365 ----------------------
3366 -- Chain_Use_Clause --
3367 ----------------------
3369 procedure Chain_Use_Clause (N : Node_Id) is
3371 Level : Int := Scope_Stack.Last;
3374 if not Is_Compilation_Unit (Current_Scope)
3375 or else not Is_Child_Unit (Current_Scope)
3377 null; -- Common case
3379 elsif Defining_Entity (Parent (N)) = Current_Scope then
3380 null; -- Common case for compilation unit
3383 -- If declaration appears in some other scope, it must be in some
3384 -- parent unit when compiling a child.
3386 Pack := Defining_Entity (Parent (N));
3387 if not In_Open_Scopes (Pack) then
3388 null; -- default as well
3391 -- Find entry for parent unit in scope stack
3393 while Scope_Stack.Table (Level).Entity /= Pack loop
3399 Set_Next_Use_Clause (N,
3400 Scope_Stack.Table (Level).First_Use_Clause);
3401 Scope_Stack.Table (Level).First_Use_Clause := N;
3402 end Chain_Use_Clause;
3404 ---------------------------
3405 -- Check_Frozen_Renaming --
3406 ---------------------------
3408 procedure Check_Frozen_Renaming (N : Node_Id; Subp : Entity_Id) is
3414 and then not Has_Completion (Subp)
3418 (Parent (Declaration_Node (Subp)), Defining_Entity (N));
3420 if Is_Entity_Name (Name (N)) then
3421 Old_S := Entity (Name (N));
3423 if not Is_Frozen (Old_S)
3424 and then Operating_Mode /= Check_Semantics
3426 Append_Freeze_Action (Old_S, B_Node);
3428 Insert_After (N, B_Node);
3432 if Is_Intrinsic_Subprogram (Old_S)
3433 and then not In_Instance
3436 ("subprogram used in renaming_as_body cannot be intrinsic",
3441 Insert_After (N, B_Node);
3445 end Check_Frozen_Renaming;
3447 -------------------------------
3448 -- Set_Entity_Or_Discriminal --
3449 -------------------------------
3451 procedure Set_Entity_Or_Discriminal (N : Node_Id; E : Entity_Id) is
3455 -- If the entity is not a discriminant, or else expansion is disabled,
3456 -- simply set the entity.
3458 if not In_Spec_Expression
3459 or else Ekind (E) /= E_Discriminant
3460 or else Inside_A_Generic
3462 Set_Entity_With_Style_Check (N, E);
3464 -- The replacement of a discriminant by the corresponding discriminal
3465 -- is not done for a task discriminant that appears in a default
3466 -- expression of an entry parameter. See Exp_Ch2.Expand_Discriminant
3467 -- for details on their handling.
3469 elsif Is_Concurrent_Type (Scope (E)) then
3473 and then not Nkind_In (P, N_Parameter_Specification,
3474 N_Component_Declaration)
3480 and then Nkind (P) = N_Parameter_Specification
3485 Set_Entity (N, Discriminal (E));
3488 -- Otherwise, this is a discriminant in a context in which
3489 -- it is a reference to the corresponding parameter of the
3490 -- init proc for the enclosing type.
3493 Set_Entity (N, Discriminal (E));
3495 end Set_Entity_Or_Discriminal;
3497 -----------------------------------
3498 -- Check_In_Previous_With_Clause --
3499 -----------------------------------
3501 procedure Check_In_Previous_With_Clause
3505 Pack : constant Entity_Id := Entity (Original_Node (Nam));
3510 Item := First (Context_Items (Parent (N)));
3512 while Present (Item)
3515 if Nkind (Item) = N_With_Clause
3517 -- Protect the frontend against previous critical errors
3519 and then Nkind (Name (Item)) /= N_Selected_Component
3520 and then Entity (Name (Item)) = Pack
3524 -- Find root library unit in with_clause
3526 while Nkind (Par) = N_Expanded_Name loop
3527 Par := Prefix (Par);
3530 if Is_Child_Unit (Entity (Original_Node (Par))) then
3531 Error_Msg_NE ("& is not directly visible", Par, Entity (Par));
3540 -- On exit, package is not mentioned in a previous with_clause.
3541 -- Check if its prefix is.
3543 if Nkind (Nam) = N_Expanded_Name then
3544 Check_In_Previous_With_Clause (N, Prefix (Nam));
3546 elsif Pack /= Any_Id then
3547 Error_Msg_NE ("& is not visible", Nam, Pack);
3549 end Check_In_Previous_With_Clause;
3551 ---------------------------------
3552 -- Check_Library_Unit_Renaming --
3553 ---------------------------------
3555 procedure Check_Library_Unit_Renaming (N : Node_Id; Old_E : Entity_Id) is
3559 if Nkind (Parent (N)) /= N_Compilation_Unit then
3562 -- Check for library unit. Note that we used to check for the scope
3563 -- being Standard here, but that was wrong for Standard itself.
3565 elsif not Is_Compilation_Unit (Old_E)
3566 and then not Is_Child_Unit (Old_E)
3568 Error_Msg_N ("renamed unit must be a library unit", Name (N));
3570 -- Entities defined in Standard (operators and boolean literals) cannot
3571 -- be renamed as library units.
3573 elsif Scope (Old_E) = Standard_Standard
3574 and then Sloc (Old_E) = Standard_Location
3576 Error_Msg_N ("renamed unit must be a library unit", Name (N));
3578 elsif Present (Parent_Spec (N))
3579 and then Nkind (Unit (Parent_Spec (N))) = N_Generic_Package_Declaration
3580 and then not Is_Child_Unit (Old_E)
3583 ("renamed unit must be a child unit of generic parent", Name (N));
3585 elsif Nkind (N) in N_Generic_Renaming_Declaration
3586 and then Nkind (Name (N)) = N_Expanded_Name
3587 and then Is_Generic_Instance (Entity (Prefix (Name (N))))
3588 and then Is_Generic_Unit (Old_E)
3591 ("renamed generic unit must be a library unit", Name (N));
3593 elsif Is_Package_Or_Generic_Package (Old_E) then
3595 -- Inherit categorization flags
3597 New_E := Defining_Entity (N);
3598 Set_Is_Pure (New_E, Is_Pure (Old_E));
3599 Set_Is_Preelaborated (New_E, Is_Preelaborated (Old_E));
3600 Set_Is_Remote_Call_Interface (New_E,
3601 Is_Remote_Call_Interface (Old_E));
3602 Set_Is_Remote_Types (New_E, Is_Remote_Types (Old_E));
3603 Set_Is_Shared_Passive (New_E, Is_Shared_Passive (Old_E));
3605 end Check_Library_Unit_Renaming;
3611 procedure End_Scope is
3617 Id := First_Entity (Current_Scope);
3618 while Present (Id) loop
3619 -- An entity in the current scope is not necessarily the first one
3620 -- on its homonym chain. Find its predecessor if any,
3621 -- If it is an internal entity, it will not be in the visibility
3622 -- chain altogether, and there is nothing to unchain.
3624 if Id /= Current_Entity (Id) then
3625 Prev := Current_Entity (Id);
3626 while Present (Prev)
3627 and then Present (Homonym (Prev))
3628 and then Homonym (Prev) /= Id
3630 Prev := Homonym (Prev);
3633 -- Skip to end of loop if Id is not in the visibility chain
3635 if No (Prev) or else Homonym (Prev) /= Id then
3643 Set_Is_Immediately_Visible (Id, False);
3645 Outer := Homonym (Id);
3646 while Present (Outer) and then Scope (Outer) = Current_Scope loop
3647 Outer := Homonym (Outer);
3650 -- Reset homonym link of other entities, but do not modify link
3651 -- between entities in current scope, so that the back-end can have
3652 -- a proper count of local overloadings.
3655 Set_Name_Entity_Id (Chars (Id), Outer);
3657 elsif Scope (Prev) /= Scope (Id) then
3658 Set_Homonym (Prev, Outer);
3665 -- If the scope generated freeze actions, place them before the
3666 -- current declaration and analyze them. Type declarations and
3667 -- the bodies of initialization procedures can generate such nodes.
3668 -- We follow the parent chain until we reach a list node, which is
3669 -- the enclosing list of declarations. If the list appears within
3670 -- a protected definition, move freeze nodes outside the protected
3674 (Scope_Stack.Table (Scope_Stack.Last).Pending_Freeze_Actions)
3678 L : constant List_Id := Scope_Stack.Table
3679 (Scope_Stack.Last).Pending_Freeze_Actions;
3682 if Is_Itype (Current_Scope) then
3683 Decl := Associated_Node_For_Itype (Current_Scope);
3685 Decl := Parent (Current_Scope);
3690 while not (Is_List_Member (Decl))
3691 or else Nkind_In (Parent (Decl), N_Protected_Definition,
3694 Decl := Parent (Decl);
3697 Insert_List_Before_And_Analyze (Decl, L);
3706 ---------------------
3707 -- End_Use_Clauses --
3708 ---------------------
3710 procedure End_Use_Clauses (Clause : Node_Id) is
3714 -- Remove Use_Type clauses first, because they affect the
3715 -- visibility of operators in subsequent used packages.
3718 while Present (U) loop
3719 if Nkind (U) = N_Use_Type_Clause then
3723 Next_Use_Clause (U);
3727 while Present (U) loop
3728 if Nkind (U) = N_Use_Package_Clause then
3729 End_Use_Package (U);
3732 Next_Use_Clause (U);
3734 end End_Use_Clauses;
3736 ---------------------
3737 -- End_Use_Package --
3738 ---------------------
3740 procedure End_Use_Package (N : Node_Id) is
3741 Pack_Name : Node_Id;
3746 function Is_Primitive_Operator_In_Use
3748 F : Entity_Id) return Boolean;
3749 -- Check whether Op is a primitive operator of a use-visible type
3751 ----------------------------------
3752 -- Is_Primitive_Operator_In_Use --
3753 ----------------------------------
3755 function Is_Primitive_Operator_In_Use
3757 F : Entity_Id) return Boolean
3759 T : constant Entity_Id := Base_Type (Etype (F));
3761 return In_Use (T) and then Scope (T) = Scope (Op);
3762 end Is_Primitive_Operator_In_Use;
3764 -- Start of processing for End_Use_Package
3767 Pack_Name := First (Names (N));
3768 while Present (Pack_Name) loop
3770 -- Test that Pack_Name actually denotes a package before processing
3772 if Is_Entity_Name (Pack_Name)
3773 and then Ekind (Entity (Pack_Name)) = E_Package
3775 Pack := Entity (Pack_Name);
3777 if In_Open_Scopes (Pack) then
3780 elsif not Redundant_Use (Pack_Name) then
3781 Set_In_Use (Pack, False);
3782 Set_Current_Use_Clause (Pack, Empty);
3784 Id := First_Entity (Pack);
3785 while Present (Id) loop
3787 -- Preserve use-visibility of operators that are primitive
3788 -- operators of a type that is use-visible through an active
3791 if Nkind (Id) = N_Defining_Operator_Symbol
3793 (Is_Primitive_Operator_In_Use
3794 (Id, First_Formal (Id))
3796 (Present (Next_Formal (First_Formal (Id)))
3798 Is_Primitive_Operator_In_Use
3799 (Id, Next_Formal (First_Formal (Id)))))
3804 Set_Is_Potentially_Use_Visible (Id, False);
3807 if Is_Private_Type (Id)
3808 and then Present (Full_View (Id))
3810 Set_Is_Potentially_Use_Visible (Full_View (Id), False);
3816 if Present (Renamed_Object (Pack)) then
3817 Set_In_Use (Renamed_Object (Pack), False);
3818 Set_Current_Use_Clause (Renamed_Object (Pack), Empty);
3821 if Chars (Pack) = Name_System
3822 and then Scope (Pack) = Standard_Standard
3823 and then Present_System_Aux
3825 Id := First_Entity (System_Aux_Id);
3826 while Present (Id) loop
3827 Set_Is_Potentially_Use_Visible (Id, False);
3829 if Is_Private_Type (Id)
3830 and then Present (Full_View (Id))
3832 Set_Is_Potentially_Use_Visible (Full_View (Id), False);
3838 Set_In_Use (System_Aux_Id, False);
3842 Set_Redundant_Use (Pack_Name, False);
3849 if Present (Hidden_By_Use_Clause (N)) then
3850 Elmt := First_Elmt (Hidden_By_Use_Clause (N));
3851 while Present (Elmt) loop
3853 E : constant Entity_Id := Node (Elmt);
3856 -- Reset either Use_Visibility or Direct_Visibility, depending
3857 -- on how the entity was hidden by the use clause.
3859 if In_Use (Scope (E))
3860 and then Used_As_Generic_Actual (Scope (E))
3862 Set_Is_Potentially_Use_Visible (Node (Elmt));
3864 Set_Is_Immediately_Visible (Node (Elmt));
3871 Set_Hidden_By_Use_Clause (N, No_Elist);
3873 end End_Use_Package;
3879 procedure End_Use_Type (N : Node_Id) is
3884 -- Start of processing for End_Use_Type
3887 Id := First (Subtype_Marks (N));
3888 while Present (Id) loop
3890 -- A call to Rtsfind may occur while analyzing a use_type clause,
3891 -- in which case the type marks are not resolved yet, and there is
3892 -- nothing to remove.
3894 if not Is_Entity_Name (Id) or else No (Entity (Id)) then
3900 if T = Any_Type or else From_With_Type (T) then
3903 -- Note that the use_type clause may mention a subtype of the type
3904 -- whose primitive operations have been made visible. Here as
3905 -- elsewhere, it is the base type that matters for visibility.
3907 elsif In_Open_Scopes (Scope (Base_Type (T))) then
3910 elsif not Redundant_Use (Id) then
3911 Set_In_Use (T, False);
3912 Set_In_Use (Base_Type (T), False);
3913 Set_Current_Use_Clause (T, Empty);
3914 Set_Current_Use_Clause (Base_Type (T), Empty);
3921 if Is_Empty_Elmt_List (Used_Operations (N)) then
3925 Elmt := First_Elmt (Used_Operations (N));
3926 while Present (Elmt) loop
3927 Set_Is_Potentially_Use_Visible (Node (Elmt), False);
3933 ----------------------
3934 -- Find_Direct_Name --
3935 ----------------------
3937 procedure Find_Direct_Name (N : Node_Id) is
3942 Inst : Entity_Id := Empty;
3943 -- Enclosing instance, if any
3945 Homonyms : Entity_Id;
3946 -- Saves start of homonym chain
3948 Nvis_Entity : Boolean;
3949 -- Set True to indicate that there is at least one entity on the homonym
3950 -- chain which, while not visible, is visible enough from the user point
3951 -- of view to warrant an error message of "not visible" rather than
3954 Nvis_Is_Private_Subprg : Boolean := False;
3955 -- Ada 2005 (AI-262): Set True to indicate that a form of Beaujolais
3956 -- effect concerning library subprograms has been detected. Used to
3957 -- generate the precise error message.
3959 function From_Actual_Package (E : Entity_Id) return Boolean;
3960 -- Returns true if the entity is declared in a package that is
3961 -- an actual for a formal package of the current instance. Such an
3962 -- entity requires special handling because it may be use-visible
3963 -- but hides directly visible entities defined outside the instance.
3965 function Is_Actual_Parameter return Boolean;
3966 -- This function checks if the node N is an identifier that is an actual
3967 -- parameter of a procedure call. If so it returns True, otherwise it
3968 -- return False. The reason for this check is that at this stage we do
3969 -- not know what procedure is being called if the procedure might be
3970 -- overloaded, so it is premature to go setting referenced flags or
3971 -- making calls to Generate_Reference. We will wait till Resolve_Actuals
3972 -- for that processing
3974 function Known_But_Invisible (E : Entity_Id) return Boolean;
3975 -- This function determines whether the entity E (which is not
3976 -- visible) can reasonably be considered to be known to the writer
3977 -- of the reference. This is a heuristic test, used only for the
3978 -- purposes of figuring out whether we prefer to complain that an
3979 -- entity is undefined or invisible (and identify the declaration
3980 -- of the invisible entity in the latter case). The point here is
3981 -- that we don't want to complain that something is invisible and
3982 -- then point to something entirely mysterious to the writer.
3984 procedure Nvis_Messages;
3985 -- Called if there are no visible entries for N, but there is at least
3986 -- one non-directly visible, or hidden declaration. This procedure
3987 -- outputs an appropriate set of error messages.
3989 procedure Undefined (Nvis : Boolean);
3990 -- This function is called if the current node has no corresponding
3991 -- visible entity or entities. The value set in Msg indicates whether
3992 -- an error message was generated (multiple error messages for the
3993 -- same variable are generally suppressed, see body for details).
3994 -- Msg is True if an error message was generated, False if not. This
3995 -- value is used by the caller to determine whether or not to output
3996 -- additional messages where appropriate. The parameter is set False
3997 -- to get the message "X is undefined", and True to get the message
3998 -- "X is not visible".
4000 -------------------------
4001 -- From_Actual_Package --
4002 -------------------------
4004 function From_Actual_Package (E : Entity_Id) return Boolean is
4005 Scop : constant Entity_Id := Scope (E);
4009 if not In_Instance then
4012 Inst := Current_Scope;
4013 while Present (Inst)
4014 and then Ekind (Inst) /= E_Package
4015 and then not Is_Generic_Instance (Inst)
4017 Inst := Scope (Inst);
4024 Act := First_Entity (Inst);
4025 while Present (Act) loop
4026 if Ekind (Act) = E_Package then
4028 -- Check for end of actuals list
4030 if Renamed_Object (Act) = Inst then
4033 elsif Present (Associated_Formal_Package (Act))
4034 and then Renamed_Object (Act) = Scop
4036 -- Entity comes from (instance of) formal package
4051 end From_Actual_Package;
4053 -------------------------
4054 -- Is_Actual_Parameter --
4055 -------------------------
4057 function Is_Actual_Parameter return Boolean is
4060 Nkind (N) = N_Identifier
4062 (Nkind (Parent (N)) = N_Procedure_Call_Statement
4064 (Nkind (Parent (N)) = N_Parameter_Association
4065 and then N = Explicit_Actual_Parameter (Parent (N))
4066 and then Nkind (Parent (Parent (N))) =
4067 N_Procedure_Call_Statement));
4068 end Is_Actual_Parameter;
4070 -------------------------
4071 -- Known_But_Invisible --
4072 -------------------------
4074 function Known_But_Invisible (E : Entity_Id) return Boolean is
4075 Fname : File_Name_Type;
4078 -- Entities in Standard are always considered to be known
4080 if Sloc (E) <= Standard_Location then
4083 -- An entity that does not come from source is always considered
4084 -- to be unknown, since it is an artifact of code expansion.
4086 elsif not Comes_From_Source (E) then
4089 -- In gnat internal mode, we consider all entities known
4091 elsif GNAT_Mode then
4095 -- Here we have an entity that is not from package Standard, and
4096 -- which comes from Source. See if it comes from an internal file.
4098 Fname := Unit_File_Name (Get_Source_Unit (E));
4100 -- Case of from internal file
4102 if Is_Internal_File_Name (Fname) then
4104 -- Private part entities in internal files are never considered
4105 -- to be known to the writer of normal application code.
4107 if Is_Hidden (E) then
4111 -- Entities from System packages other than System and
4112 -- System.Storage_Elements are not considered to be known.
4113 -- System.Auxxxx files are also considered known to the user.
4115 -- Should refine this at some point to generally distinguish
4116 -- between known and unknown internal files ???
4118 Get_Name_String (Fname);
4123 Name_Buffer (1 .. 2) /= "s-"
4125 Name_Buffer (3 .. 8) = "stoele"
4127 Name_Buffer (3 .. 5) = "aux";
4129 -- If not an internal file, then entity is definitely known,
4130 -- even if it is in a private part (the message generated will
4131 -- note that it is in a private part)
4136 end Known_But_Invisible;
4142 procedure Nvis_Messages is
4143 Comp_Unit : Node_Id;
4145 Found : Boolean := False;
4146 Hidden : Boolean := False;
4150 -- Ada 2005 (AI-262): Generate a precise error concerning the
4151 -- Beaujolais effect that was previously detected
4153 if Nvis_Is_Private_Subprg then
4155 pragma Assert (Nkind (E2) = N_Defining_Identifier
4156 and then Ekind (E2) = E_Function
4157 and then Scope (E2) = Standard_Standard
4158 and then Has_Private_With (E2));
4160 -- Find the sloc corresponding to the private with'ed unit
4162 Comp_Unit := Cunit (Current_Sem_Unit);
4163 Error_Msg_Sloc := No_Location;
4165 Item := First (Context_Items (Comp_Unit));
4166 while Present (Item) loop
4167 if Nkind (Item) = N_With_Clause
4168 and then Private_Present (Item)
4169 and then Entity (Name (Item)) = E2
4171 Error_Msg_Sloc := Sloc (Item);
4178 pragma Assert (Error_Msg_Sloc /= No_Location);
4180 Error_Msg_N ("(Ada 2005): hidden by private with clause #", N);
4184 Undefined (Nvis => True);
4188 -- First loop does hidden declarations
4191 while Present (Ent) loop
4192 if Is_Potentially_Use_Visible (Ent) then
4194 Error_Msg_N -- CODEFIX
4195 ("multiple use clauses cause hiding!", N);
4199 Error_Msg_Sloc := Sloc (Ent);
4200 Error_Msg_N -- CODEFIX
4201 ("hidden declaration#!", N);
4204 Ent := Homonym (Ent);
4207 -- If we found hidden declarations, then that's enough, don't
4208 -- bother looking for non-visible declarations as well.
4214 -- Second loop does non-directly visible declarations
4217 while Present (Ent) loop
4218 if not Is_Potentially_Use_Visible (Ent) then
4220 -- Do not bother the user with unknown entities
4222 if not Known_But_Invisible (Ent) then
4226 Error_Msg_Sloc := Sloc (Ent);
4228 -- Output message noting that there is a non-visible
4229 -- declaration, distinguishing the private part case.
4231 if Is_Hidden (Ent) then
4232 Error_Msg_N ("non-visible (private) declaration#!", N);
4234 -- If the entity is declared in a generic package, it
4235 -- cannot be visible, so there is no point in adding it
4236 -- to the list of candidates if another homograph from a
4237 -- non-generic package has been seen.
4239 elsif Ekind (Scope (Ent)) = E_Generic_Package
4245 Error_Msg_N -- CODEFIX
4246 ("non-visible declaration#!", N);
4248 if Ekind (Scope (Ent)) /= E_Generic_Package then
4252 if Is_Compilation_Unit (Ent)
4254 Nkind (Parent (Parent (N))) = N_Use_Package_Clause
4256 Error_Msg_Qual_Level := 99;
4257 Error_Msg_NE -- CODEFIX
4258 ("\\missing `WITH &;`", N, Ent);
4259 Error_Msg_Qual_Level := 0;
4262 if Ekind (Ent) = E_Discriminant
4263 and then Present (Corresponding_Discriminant (Ent))
4264 and then Scope (Corresponding_Discriminant (Ent)) =
4268 ("inherited discriminant not allowed here" &
4269 " (RM 3.8 (12), 3.8.1 (6))!", N);
4273 -- Set entity and its containing package as referenced. We
4274 -- can't be sure of this, but this seems a better choice
4275 -- to avoid unused entity messages.
4277 if Comes_From_Source (Ent) then
4278 Set_Referenced (Ent);
4279 Set_Referenced (Cunit_Entity (Get_Source_Unit (Ent)));
4284 Ent := Homonym (Ent);
4293 procedure Undefined (Nvis : Boolean) is
4294 Emsg : Error_Msg_Id;
4297 -- We should never find an undefined internal name. If we do, then
4298 -- see if we have previous errors. If so, ignore on the grounds that
4299 -- it is probably a cascaded message (e.g. a block label from a badly
4300 -- formed block). If no previous errors, then we have a real internal
4301 -- error of some kind so raise an exception.
4303 if Is_Internal_Name (Chars (N)) then
4304 if Total_Errors_Detected /= 0 then
4307 raise Program_Error;
4311 -- A very specialized error check, if the undefined variable is
4312 -- a case tag, and the case type is an enumeration type, check
4313 -- for a possible misspelling, and if so, modify the identifier
4315 -- Named aggregate should also be handled similarly ???
4317 if Nkind (N) = N_Identifier
4318 and then Nkind (Parent (N)) = N_Case_Statement_Alternative
4321 Case_Stm : constant Node_Id := Parent (Parent (N));
4322 Case_Typ : constant Entity_Id := Etype (Expression (Case_Stm));
4327 if Is_Enumeration_Type (Case_Typ)
4328 and then not Is_Standard_Character_Type (Case_Typ)
4330 Lit := First_Literal (Case_Typ);
4331 Get_Name_String (Chars (Lit));
4333 if Chars (Lit) /= Chars (N)
4334 and then Is_Bad_Spelling_Of (Chars (N), Chars (Lit)) then
4335 Error_Msg_Node_2 := Lit;
4336 Error_Msg_N -- CODEFIX
4337 ("& is undefined, assume misspelling of &", N);
4338 Rewrite (N, New_Occurrence_Of (Lit, Sloc (N)));
4342 Lit := Next_Literal (Lit);
4347 -- Normal processing
4349 Set_Entity (N, Any_Id);
4350 Set_Etype (N, Any_Type);
4352 -- We use the table Urefs to keep track of entities for which we
4353 -- have issued errors for undefined references. Multiple errors
4354 -- for a single name are normally suppressed, however we modify
4355 -- the error message to alert the programmer to this effect.
4357 for J in Urefs.First .. Urefs.Last loop
4358 if Chars (N) = Chars (Urefs.Table (J).Node) then
4359 if Urefs.Table (J).Err /= No_Error_Msg
4360 and then Sloc (N) /= Urefs.Table (J).Loc
4362 Error_Msg_Node_1 := Urefs.Table (J).Node;
4364 if Urefs.Table (J).Nvis then
4365 Change_Error_Text (Urefs.Table (J).Err,
4366 "& is not visible (more references follow)");
4368 Change_Error_Text (Urefs.Table (J).Err,
4369 "& is undefined (more references follow)");
4372 Urefs.Table (J).Err := No_Error_Msg;
4375 -- Although we will set Msg False, and thus suppress the
4376 -- message, we also set Error_Posted True, to avoid any
4377 -- cascaded messages resulting from the undefined reference.
4380 Set_Error_Posted (N, True);
4385 -- If entry not found, this is first undefined occurrence
4388 Error_Msg_N ("& is not visible!", N);
4392 Error_Msg_N ("& is undefined!", N);
4395 -- A very bizarre special check, if the undefined identifier
4396 -- is put or put_line, then add a special error message (since
4397 -- this is a very common error for beginners to make).
4399 if Chars (N) = Name_Put or else Chars (N) = Name_Put_Line then
4400 Error_Msg_N -- CODEFIX
4401 ("\\possible missing `WITH Ada.Text_'I'O; " &
4402 "USE Ada.Text_'I'O`!", N);
4404 -- Another special check if N is the prefix of a selected
4405 -- component which is a known unit, add message complaining
4406 -- about missing with for this unit.
4408 elsif Nkind (Parent (N)) = N_Selected_Component
4409 and then N = Prefix (Parent (N))
4410 and then Is_Known_Unit (Parent (N))
4412 Error_Msg_Node_2 := Selector_Name (Parent (N));
4413 Error_Msg_N -- CODEFIX
4414 ("\\missing `WITH &.&;`", Prefix (Parent (N)));
4417 -- Now check for possible misspellings
4421 Ematch : Entity_Id := Empty;
4423 Last_Name_Id : constant Name_Id :=
4424 Name_Id (Nat (First_Name_Id) +
4425 Name_Entries_Count - 1);
4428 for Nam in First_Name_Id .. Last_Name_Id loop
4429 E := Get_Name_Entity_Id (Nam);
4432 and then (Is_Immediately_Visible (E)
4434 Is_Potentially_Use_Visible (E))
4436 if Is_Bad_Spelling_Of (Chars (N), Nam) then
4443 if Present (Ematch) then
4444 Error_Msg_NE -- CODEFIX
4445 ("\possible misspelling of&", N, Ematch);
4450 -- Make entry in undefined references table unless the full errors
4451 -- switch is set, in which case by refraining from generating the
4452 -- table entry, we guarantee that we get an error message for every
4453 -- undefined reference.
4455 if not All_Errors_Mode then
4466 -- Start of processing for Find_Direct_Name
4469 -- If the entity pointer is already set, this is an internal node, or
4470 -- a node that is analyzed more than once, after a tree modification.
4471 -- In such a case there is no resolution to perform, just set the type.
4473 if Present (Entity (N)) then
4474 if Is_Type (Entity (N)) then
4475 Set_Etype (N, Entity (N));
4479 Entyp : constant Entity_Id := Etype (Entity (N));
4482 -- One special case here. If the Etype field is already set,
4483 -- and references the packed array type corresponding to the
4484 -- etype of the referenced entity, then leave it alone. This
4485 -- happens for trees generated from Exp_Pakd, where expressions
4486 -- can be deliberately "mis-typed" to the packed array type.
4488 if Is_Array_Type (Entyp)
4489 and then Is_Packed (Entyp)
4490 and then Present (Etype (N))
4491 and then Etype (N) = Packed_Array_Type (Entyp)
4495 -- If not that special case, then just reset the Etype
4498 Set_Etype (N, Etype (Entity (N)));
4506 -- Here if Entity pointer was not set, we need full visibility analysis
4507 -- First we generate debugging output if the debug E flag is set.
4509 if Debug_Flag_E then
4510 Write_Str ("Looking for ");
4511 Write_Name (Chars (N));
4515 Homonyms := Current_Entity (N);
4516 Nvis_Entity := False;
4519 while Present (E) loop
4521 -- If entity is immediately visible or potentially use visible, then
4522 -- process the entity and we are done.
4524 if Is_Immediately_Visible (E) then
4525 goto Immediately_Visible_Entity;
4527 elsif Is_Potentially_Use_Visible (E) then
4528 goto Potentially_Use_Visible_Entity;
4530 -- Note if a known but invisible entity encountered
4532 elsif Known_But_Invisible (E) then
4533 Nvis_Entity := True;
4536 -- Move to next entity in chain and continue search
4541 -- If no entries on homonym chain that were potentially visible,
4542 -- and no entities reasonably considered as non-visible, then
4543 -- we have a plain undefined reference, with no additional
4544 -- explanation required!
4546 if not Nvis_Entity then
4547 Undefined (Nvis => False);
4549 -- Otherwise there is at least one entry on the homonym chain that
4550 -- is reasonably considered as being known and non-visible.
4558 -- Processing for a potentially use visible entry found. We must search
4559 -- the rest of the homonym chain for two reasons. First, if there is a
4560 -- directly visible entry, then none of the potentially use-visible
4561 -- entities are directly visible (RM 8.4(10)). Second, we need to check
4562 -- for the case of multiple potentially use-visible entries hiding one
4563 -- another and as a result being non-directly visible (RM 8.4(11)).
4565 <<Potentially_Use_Visible_Entity>> declare
4566 Only_One_Visible : Boolean := True;
4567 All_Overloadable : Boolean := Is_Overloadable (E);
4571 while Present (E2) loop
4572 if Is_Immediately_Visible (E2) then
4574 -- If the use-visible entity comes from the actual for a
4575 -- formal package, it hides a directly visible entity from
4576 -- outside the instance.
4578 if From_Actual_Package (E)
4579 and then Scope_Depth (E2) < Scope_Depth (Inst)
4584 goto Immediately_Visible_Entity;
4587 elsif Is_Potentially_Use_Visible (E2) then
4588 Only_One_Visible := False;
4589 All_Overloadable := All_Overloadable and Is_Overloadable (E2);
4591 -- Ada 2005 (AI-262): Protect against a form of Beaujolais effect
4592 -- that can occur in private_with clauses. Example:
4595 -- private with B; package A is
4596 -- package C is function B return Integer;
4598 -- V1 : Integer := B;
4599 -- private function B return Integer;
4600 -- V2 : Integer := B;
4603 -- V1 resolves to A.B, but V2 resolves to library unit B
4605 elsif Ekind (E2) = E_Function
4606 and then Scope (E2) = Standard_Standard
4607 and then Has_Private_With (E2)
4609 Only_One_Visible := False;
4610 All_Overloadable := False;
4611 Nvis_Is_Private_Subprg := True;
4618 -- On falling through this loop, we have checked that there are no
4619 -- immediately visible entities. Only_One_Visible is set if exactly
4620 -- one potentially use visible entity exists. All_Overloadable is
4621 -- set if all the potentially use visible entities are overloadable.
4622 -- The condition for legality is that either there is one potentially
4623 -- use visible entity, or if there is more than one, then all of them
4624 -- are overloadable.
4626 if Only_One_Visible or All_Overloadable then
4629 -- If there is more than one potentially use-visible entity and at
4630 -- least one of them non-overloadable, we have an error (RM 8.4(11).
4631 -- Note that E points to the first such entity on the homonym list.
4632 -- Special case: if one of the entities is declared in an actual
4633 -- package, it was visible in the generic, and takes precedence over
4634 -- other entities that are potentially use-visible. Same if it is
4635 -- declared in a local instantiation of the current instance.
4640 -- Find current instance
4642 Inst := Current_Scope;
4643 while Present (Inst)
4644 and then Inst /= Standard_Standard
4646 if Is_Generic_Instance (Inst) then
4650 Inst := Scope (Inst);
4654 while Present (E2) loop
4655 if From_Actual_Package (E2)
4657 (Is_Generic_Instance (Scope (E2))
4658 and then Scope_Depth (Scope (E2)) > Scope_Depth (Inst))
4671 Is_Predefined_File_Name (Unit_File_Name (Current_Sem_Unit))
4673 -- A use-clause in the body of a system file creates conflict
4674 -- with some entity in a user scope, while rtsfind is active.
4675 -- Keep only the entity coming from another predefined unit.
4678 while Present (E2) loop
4679 if Is_Predefined_File_Name
4680 (Unit_File_Name (Get_Source_Unit (Sloc (E2))))
4689 -- Entity must exist because predefined unit is correct
4691 raise Program_Error;
4700 -- Come here with E set to the first immediately visible entity on
4701 -- the homonym chain. This is the one we want unless there is another
4702 -- immediately visible entity further on in the chain for an inner
4703 -- scope (RM 8.3(8)).
4705 <<Immediately_Visible_Entity>> declare
4710 -- Find scope level of initial entity. When compiling through
4711 -- Rtsfind, the previous context is not completely invisible, and
4712 -- an outer entity may appear on the chain, whose scope is below
4713 -- the entry for Standard that delimits the current scope stack.
4714 -- Indicate that the level for this spurious entry is outside of
4715 -- the current scope stack.
4717 Level := Scope_Stack.Last;
4719 Scop := Scope_Stack.Table (Level).Entity;
4720 exit when Scop = Scope (E);
4722 exit when Scop = Standard_Standard;
4725 -- Now search remainder of homonym chain for more inner entry
4726 -- If the entity is Standard itself, it has no scope, and we
4727 -- compare it with the stack entry directly.
4730 while Present (E2) loop
4731 if Is_Immediately_Visible (E2) then
4733 -- If a generic package contains a local declaration that
4734 -- has the same name as the generic, there may be a visibility
4735 -- conflict in an instance, where the local declaration must
4736 -- also hide the name of the corresponding package renaming.
4737 -- We check explicitly for a package declared by a renaming,
4738 -- whose renamed entity is an instance that is on the scope
4739 -- stack, and that contains a homonym in the same scope. Once
4740 -- we have found it, we know that the package renaming is not
4741 -- immediately visible, and that the identifier denotes the
4742 -- other entity (and its homonyms if overloaded).
4744 if Scope (E) = Scope (E2)
4745 and then Ekind (E) = E_Package
4746 and then Present (Renamed_Object (E))
4747 and then Is_Generic_Instance (Renamed_Object (E))
4748 and then In_Open_Scopes (Renamed_Object (E))
4749 and then Comes_From_Source (N)
4751 Set_Is_Immediately_Visible (E, False);
4755 for J in Level + 1 .. Scope_Stack.Last loop
4756 if Scope_Stack.Table (J).Entity = Scope (E2)
4757 or else Scope_Stack.Table (J).Entity = E2
4770 -- At the end of that loop, E is the innermost immediately
4771 -- visible entity, so we are all set.
4774 -- Come here with entity found, and stored in E
4778 -- Check violation of No_Wide_Characters restriction
4780 Check_Wide_Character_Restriction (E, N);
4782 -- When distribution features are available (Get_PCS_Name /=
4783 -- Name_No_DSA), a remote access-to-subprogram type is converted
4784 -- into a record type holding whatever information is needed to
4785 -- perform a remote call on an RCI subprogram. In that case we
4786 -- rewrite any occurrence of the RAS type into the equivalent record
4787 -- type here. 'Access attribute references and RAS dereferences are
4788 -- then implemented using specific TSSs. However when distribution is
4789 -- not available (case of Get_PCS_Name = Name_No_DSA), we bypass the
4790 -- generation of these TSSs, and we must keep the RAS type in its
4791 -- original access-to-subprogram form (since all calls through a
4792 -- value of such type will be local anyway in the absence of a PCS).
4794 if Comes_From_Source (N)
4795 and then Is_Remote_Access_To_Subprogram_Type (E)
4796 and then Expander_Active
4797 and then Get_PCS_Name /= Name_No_DSA
4800 New_Occurrence_Of (Equivalent_Type (E), Sloc (N)));
4804 -- Set the entity. Note that the reason we call Set_Entity for the
4805 -- overloadable case, as opposed to Set_Entity_With_Style_Check is
4806 -- that in the overloaded case, the initial call can set the wrong
4807 -- homonym. The call that sets the right homonym is in Sem_Res and
4808 -- that call does use Set_Entity_With_Style_Check, so we don't miss
4811 if Is_Overloadable (E) then
4814 Set_Entity_With_Style_Check (N, E);
4820 Set_Etype (N, Get_Full_View (Etype (E)));
4823 if Debug_Flag_E then
4824 Write_Str (" found ");
4825 Write_Entity_Info (E, " ");
4828 -- If the Ekind of the entity is Void, it means that all homonyms
4829 -- are hidden from all visibility (RM 8.3(5,14-20)). However, this
4830 -- test is skipped if the current scope is a record and the name is
4831 -- a pragma argument expression (case of Atomic and Volatile pragmas
4832 -- and possibly other similar pragmas added later, which are allowed
4833 -- to reference components in the current record).
4835 if Ekind (E) = E_Void
4837 (not Is_Record_Type (Current_Scope)
4838 or else Nkind (Parent (N)) /= N_Pragma_Argument_Association)
4840 Premature_Usage (N);
4842 -- If the entity is overloadable, collect all interpretations of the
4843 -- name for subsequent overload resolution. We optimize a bit here to
4844 -- do this only if we have an overloadable entity that is not on its
4845 -- own on the homonym chain.
4847 elsif Is_Overloadable (E)
4848 and then (Present (Homonym (E)) or else Current_Entity (N) /= E)
4850 Collect_Interps (N);
4852 -- If no homonyms were visible, the entity is unambiguous
4854 if not Is_Overloaded (N) then
4855 if not Is_Actual_Parameter then
4856 Generate_Reference (E, N);
4860 -- Case of non-overloadable entity, set the entity providing that
4861 -- we do not have the case of a discriminant reference within a
4862 -- default expression. Such references are replaced with the
4863 -- corresponding discriminal, which is the formal corresponding to
4864 -- to the discriminant in the initialization procedure.
4867 -- Entity is unambiguous, indicate that it is referenced here
4869 -- For a renaming of an object, always generate simple reference,
4870 -- we don't try to keep track of assignments in this case.
4872 if Is_Object (E) and then Present (Renamed_Object (E)) then
4873 Generate_Reference (E, N);
4875 -- If the renamed entity is a private protected component,
4876 -- reference the original component as well. This needs to be
4877 -- done because the private renamings are installed before any
4878 -- analysis has occurred. Reference to a private component will
4879 -- resolve to the renaming and the original component will be
4880 -- left unreferenced, hence the following.
4882 if Is_Prival (E) then
4883 Generate_Reference (Prival_Link (E), N);
4886 -- One odd case is that we do not want to set the Referenced flag
4887 -- if the entity is a label, and the identifier is the label in
4888 -- the source, since this is not a reference from the point of
4889 -- view of the user.
4891 elsif Nkind (Parent (N)) = N_Label then
4893 R : constant Boolean := Referenced (E);
4896 -- Generate reference unless this is an actual parameter
4897 -- (see comment below)
4899 if Is_Actual_Parameter then
4900 Generate_Reference (E, N);
4901 Set_Referenced (E, R);
4905 -- Normal case, not a label: generate reference
4907 -- ??? It is too early to generate a reference here even if the
4908 -- entity is unambiguous, because the tree is not sufficiently
4909 -- typed at this point for Generate_Reference to determine
4910 -- whether this reference modifies the denoted object (because
4911 -- implicit dereferences cannot be identified prior to full type
4914 -- The Is_Actual_Parameter routine takes care of one of these
4915 -- cases but there are others probably ???
4917 -- If the entity is the LHS of an assignment, and is a variable
4918 -- (rather than a package prefix), we can mark it as a
4919 -- modification right away, to avoid duplicate references.
4922 if not Is_Actual_Parameter then
4924 and then Ekind (E) /= E_Package
4925 and then Ekind (E) /= E_Generic_Package
4927 Generate_Reference (E, N, 'm');
4929 Generate_Reference (E, N);
4933 Check_Nested_Access (E);
4936 Set_Entity_Or_Discriminal (N, E);
4938 if Ada_Version >= Ada_2012
4940 (Nkind (Parent (N)) in N_Subexpr
4941 or else Nkind (Parent (N)) = N_Object_Declaration)
4943 Check_Implicit_Dereference (N, Etype (E));
4947 end Find_Direct_Name;
4949 ------------------------
4950 -- Find_Expanded_Name --
4951 ------------------------
4953 -- This routine searches the homonym chain of the entity until it finds
4954 -- an entity declared in the scope denoted by the prefix. If the entity
4955 -- is private, it may nevertheless be immediately visible, if we are in
4956 -- the scope of its declaration.
4958 procedure Find_Expanded_Name (N : Node_Id) is
4959 Selector : constant Node_Id := Selector_Name (N);
4960 Candidate : Entity_Id := Empty;
4966 P_Name := Entity (Prefix (N));
4969 -- If the prefix is a renamed package, look for the entity in the
4970 -- original package.
4972 if Ekind (P_Name) = E_Package
4973 and then Present (Renamed_Object (P_Name))
4975 P_Name := Renamed_Object (P_Name);
4977 -- Rewrite node with entity field pointing to renamed object
4979 Rewrite (Prefix (N), New_Copy (Prefix (N)));
4980 Set_Entity (Prefix (N), P_Name);
4982 -- If the prefix is an object of a concurrent type, look for
4983 -- the entity in the associated task or protected type.
4985 elsif Is_Concurrent_Type (Etype (P_Name)) then
4986 P_Name := Etype (P_Name);
4989 Id := Current_Entity (Selector);
4992 Is_New_Candidate : Boolean;
4995 while Present (Id) loop
4996 if Scope (Id) = P_Name then
4998 Is_New_Candidate := True;
5000 -- Ada 2005 (AI-217): Handle shadow entities associated with types
5001 -- declared in limited-withed nested packages. We don't need to
5002 -- handle E_Incomplete_Subtype entities because the entities in
5003 -- the limited view are always E_Incomplete_Type entities (see
5004 -- Build_Limited_Views). Regarding the expression used to evaluate
5005 -- the scope, it is important to note that the limited view also
5006 -- has shadow entities associated nested packages. For this reason
5007 -- the correct scope of the entity is the scope of the real entity
5008 -- The non-limited view may itself be incomplete, in which case
5009 -- get the full view if available.
5011 elsif From_With_Type (Id)
5012 and then Is_Type (Id)
5013 and then Ekind (Id) = E_Incomplete_Type
5014 and then Present (Non_Limited_View (Id))
5015 and then Scope (Non_Limited_View (Id)) = P_Name
5017 Candidate := Get_Full_View (Non_Limited_View (Id));
5018 Is_New_Candidate := True;
5021 Is_New_Candidate := False;
5024 if Is_New_Candidate then
5025 if Is_Child_Unit (Id) then
5026 exit when Is_Visible_Child_Unit (Id)
5027 or else Is_Immediately_Visible (Id);
5030 exit when not Is_Hidden (Id)
5031 or else Is_Immediately_Visible (Id);
5040 and then (Ekind (P_Name) = E_Procedure
5042 Ekind (P_Name) = E_Function)
5043 and then Is_Generic_Instance (P_Name)
5045 -- Expanded name denotes entity in (instance of) generic subprogram.
5046 -- The entity may be in the subprogram instance, or may denote one of
5047 -- the formals, which is declared in the enclosing wrapper package.
5049 P_Name := Scope (P_Name);
5051 Id := Current_Entity (Selector);
5052 while Present (Id) loop
5053 exit when Scope (Id) = P_Name;
5058 if No (Id) or else Chars (Id) /= Chars (Selector) then
5059 Set_Etype (N, Any_Type);
5061 -- If we are looking for an entity defined in System, try to find it
5062 -- in the child package that may have been provided as an extension
5063 -- to System. The Extend_System pragma will have supplied the name of
5064 -- the extension, which may have to be loaded.
5066 if Chars (P_Name) = Name_System
5067 and then Scope (P_Name) = Standard_Standard
5068 and then Present (System_Extend_Unit)
5069 and then Present_System_Aux (N)
5071 Set_Entity (Prefix (N), System_Aux_Id);
5072 Find_Expanded_Name (N);
5075 elsif Nkind (Selector) = N_Operator_Symbol
5076 and then Has_Implicit_Operator (N)
5078 -- There is an implicit instance of the predefined operator in
5079 -- the given scope. The operator entity is defined in Standard.
5080 -- Has_Implicit_Operator makes the node into an Expanded_Name.
5084 elsif Nkind (Selector) = N_Character_Literal
5085 and then Has_Implicit_Character_Literal (N)
5087 -- If there is no literal defined in the scope denoted by the
5088 -- prefix, the literal may belong to (a type derived from)
5089 -- Standard_Character, for which we have no explicit literals.
5094 -- If the prefix is a single concurrent object, use its name in
5095 -- the error message, rather than that of the anonymous type.
5097 if Is_Concurrent_Type (P_Name)
5098 and then Is_Internal_Name (Chars (P_Name))
5100 Error_Msg_Node_2 := Entity (Prefix (N));
5102 Error_Msg_Node_2 := P_Name;
5105 if P_Name = System_Aux_Id then
5106 P_Name := Scope (P_Name);
5107 Set_Entity (Prefix (N), P_Name);
5110 if Present (Candidate) then
5112 -- If we know that the unit is a child unit we can give a more
5113 -- accurate error message.
5115 if Is_Child_Unit (Candidate) then
5117 -- If the candidate is a private child unit and we are in
5118 -- the visible part of a public unit, specialize the error
5119 -- message. There might be a private with_clause for it,
5120 -- but it is not currently active.
5122 if Is_Private_Descendant (Candidate)
5123 and then Ekind (Current_Scope) = E_Package
5124 and then not In_Private_Part (Current_Scope)
5125 and then not Is_Private_Descendant (Current_Scope)
5127 Error_Msg_N ("private child unit& is not visible here",
5130 -- Normal case where we have a missing with for a child unit
5133 Error_Msg_Qual_Level := 99;
5134 Error_Msg_NE -- CODEFIX
5135 ("missing `WITH &;`", Selector, Candidate);
5136 Error_Msg_Qual_Level := 0;
5139 -- Here we don't know that this is a child unit
5142 Error_Msg_NE ("& is not a visible entity of&", N, Selector);
5146 -- Within the instantiation of a child unit, the prefix may
5147 -- denote the parent instance, but the selector has the name
5148 -- of the original child. Find whether we are within the
5149 -- corresponding instance, and get the proper entity, which
5150 -- can only be an enclosing scope.
5153 and then In_Open_Scopes (P_Name)
5154 and then Is_Generic_Instance (P_Name)
5157 S : Entity_Id := Current_Scope;
5161 for J in reverse 0 .. Scope_Stack.Last loop
5162 S := Scope_Stack.Table (J).Entity;
5164 exit when S = Standard_Standard;
5166 if Ekind_In (S, E_Function,
5170 P := Generic_Parent (Specification
5171 (Unit_Declaration_Node (S)));
5174 and then Chars (Scope (P)) = Chars (O_Name)
5175 and then Chars (P) = Chars (Selector)
5186 -- If this is a selection from Ada, System or Interfaces, then
5187 -- we assume a missing with for the corresponding package.
5189 if Is_Known_Unit (N) then
5190 if not Error_Posted (N) then
5191 Error_Msg_Node_2 := Selector;
5192 Error_Msg_N -- CODEFIX
5193 ("missing `WITH &.&;`", Prefix (N));
5196 -- If this is a selection from a dummy package, then suppress
5197 -- the error message, of course the entity is missing if the
5198 -- package is missing!
5200 elsif Sloc (Error_Msg_Node_2) = No_Location then
5203 -- Here we have the case of an undefined component
5207 -- The prefix may hide a homonym in the context that
5208 -- declares the desired entity. This error can use a
5209 -- specialized message.
5211 if In_Open_Scopes (P_Name)
5212 and then Present (Homonym (P_Name))
5213 and then Is_Compilation_Unit (Homonym (P_Name))
5215 (Is_Immediately_Visible (Homonym (P_Name))
5216 or else Is_Visible_Child_Unit (Homonym (P_Name)))
5219 H : constant Entity_Id := Homonym (P_Name);
5222 Id := First_Entity (H);
5223 while Present (Id) loop
5224 if Chars (Id) = Chars (Selector) then
5225 Error_Msg_Qual_Level := 99;
5226 Error_Msg_Name_1 := Chars (Selector);
5228 ("% not declared in&", N, P_Name);
5230 ("\use fully qualified name starting with"
5231 & " Standard to make& visible", N, H);
5232 Error_Msg_Qual_Level := 0;
5239 -- If not found, standard error message
5241 Error_Msg_NE ("& not declared in&", N, Selector);
5247 Error_Msg_NE ("& not declared in&", N, Selector);
5250 -- Check for misspelling of some entity in prefix
5252 Id := First_Entity (P_Name);
5253 while Present (Id) loop
5254 if Is_Bad_Spelling_Of (Chars (Id), Chars (Selector))
5255 and then not Is_Internal_Name (Chars (Id))
5257 Error_Msg_NE -- CODEFIX
5258 ("possible misspelling of&", Selector, Id);
5265 -- Specialize the message if this may be an instantiation
5266 -- of a child unit that was not mentioned in the context.
5268 if Nkind (Parent (N)) = N_Package_Instantiation
5269 and then Is_Generic_Instance (Entity (Prefix (N)))
5270 and then Is_Compilation_Unit
5271 (Generic_Parent (Parent (Entity (Prefix (N)))))
5273 Error_Msg_Node_2 := Selector;
5274 Error_Msg_N -- CODEFIX
5275 ("\missing `WITH &.&;`", Prefix (N));
5285 if Comes_From_Source (N)
5286 and then Is_Remote_Access_To_Subprogram_Type (Id)
5287 and then Present (Equivalent_Type (Id))
5289 -- If we are not actually generating distribution code (i.e. the
5290 -- current PCS is the dummy non-distributed version), then the
5291 -- Equivalent_Type will be missing, and Id should be treated as
5292 -- a regular access-to-subprogram type.
5294 Id := Equivalent_Type (Id);
5295 Set_Chars (Selector, Chars (Id));
5298 -- Ada 2005 (AI-50217): Check usage of entities in limited withed units
5300 if Ekind (P_Name) = E_Package
5301 and then From_With_Type (P_Name)
5303 if From_With_Type (Id)
5304 or else Is_Type (Id)
5305 or else Ekind (Id) = E_Package
5310 ("limited withed package can only be used to access "
5311 & "incomplete types",
5316 if Is_Task_Type (P_Name)
5317 and then ((Ekind (Id) = E_Entry
5318 and then Nkind (Parent (N)) /= N_Attribute_Reference)
5320 (Ekind (Id) = E_Entry_Family
5322 Nkind (Parent (Parent (N))) /= N_Attribute_Reference))
5324 -- It is an entry call after all, either to the current task (which
5325 -- will deadlock) or to an enclosing task.
5327 Analyze_Selected_Component (N);
5331 Change_Selected_Component_To_Expanded_Name (N);
5333 -- Do style check and generate reference, but skip both steps if this
5334 -- entity has homonyms, since we may not have the right homonym set yet.
5335 -- The proper homonym will be set during the resolve phase.
5337 if Has_Homonym (Id) then
5340 Set_Entity_Or_Discriminal (N, Id);
5343 Generate_Reference (Id, N, 'm');
5345 Generate_Reference (Id, N);
5349 if Is_Type (Id) then
5352 Set_Etype (N, Get_Full_View (Etype (Id)));
5355 -- Check for violation of No_Wide_Characters
5357 Check_Wide_Character_Restriction (Id, N);
5359 -- If the Ekind of the entity is Void, it means that all homonyms are
5360 -- hidden from all visibility (RM 8.3(5,14-20)).
5362 if Ekind (Id) = E_Void then
5363 Premature_Usage (N);
5365 elsif Is_Overloadable (Id)
5366 and then Present (Homonym (Id))
5369 H : Entity_Id := Homonym (Id);
5372 while Present (H) loop
5373 if Scope (H) = Scope (Id)
5376 or else Is_Immediately_Visible (H))
5378 Collect_Interps (N);
5385 -- If an extension of System is present, collect possible explicit
5386 -- overloadings declared in the extension.
5388 if Chars (P_Name) = Name_System
5389 and then Scope (P_Name) = Standard_Standard
5390 and then Present (System_Extend_Unit)
5391 and then Present_System_Aux (N)
5393 H := Current_Entity (Id);
5395 while Present (H) loop
5396 if Scope (H) = System_Aux_Id then
5397 Add_One_Interp (N, H, Etype (H));
5406 if Nkind (Selector_Name (N)) = N_Operator_Symbol
5407 and then Scope (Id) /= Standard_Standard
5409 -- In addition to user-defined operators in the given scope, there
5410 -- may be an implicit instance of the predefined operator. The
5411 -- operator (defined in Standard) is found in Has_Implicit_Operator,
5412 -- and added to the interpretations. Procedure Add_One_Interp will
5413 -- determine which hides which.
5415 if Has_Implicit_Operator (N) then
5419 end Find_Expanded_Name;
5421 -------------------------
5422 -- Find_Renamed_Entity --
5423 -------------------------
5425 function Find_Renamed_Entity
5429 Is_Actual : Boolean := False) return Entity_Id
5432 I1 : Interp_Index := 0; -- Suppress junk warnings
5438 function Enclosing_Instance return Entity_Id;
5439 -- If the renaming determines the entity for the default of a formal
5440 -- subprogram nested within another instance, choose the innermost
5441 -- candidate. This is because if the formal has a box, and we are within
5442 -- an enclosing instance where some candidate interpretations are local
5443 -- to this enclosing instance, we know that the default was properly
5444 -- resolved when analyzing the generic, so we prefer the local
5445 -- candidates to those that are external. This is not always the case
5446 -- but is a reasonable heuristic on the use of nested generics. The
5447 -- proper solution requires a full renaming model.
5449 function Is_Visible_Operation (Op : Entity_Id) return Boolean;
5450 -- If the renamed entity is an implicit operator, check whether it is
5451 -- visible because its operand type is properly visible. This check
5452 -- applies to explicit renamed entities that appear in the source in a
5453 -- renaming declaration or a formal subprogram instance, but not to
5454 -- default generic actuals with a name.
5456 function Report_Overload return Entity_Id;
5457 -- List possible interpretations, and specialize message in the
5458 -- case of a generic actual.
5460 function Within (Inner, Outer : Entity_Id) return Boolean;
5461 -- Determine whether a candidate subprogram is defined within the
5462 -- enclosing instance. If yes, it has precedence over outer candidates.
5464 ------------------------
5465 -- Enclosing_Instance --
5466 ------------------------
5468 function Enclosing_Instance return Entity_Id is
5472 if not Is_Generic_Instance (Current_Scope)
5473 and then not Is_Actual
5478 S := Scope (Current_Scope);
5479 while S /= Standard_Standard loop
5480 if Is_Generic_Instance (S) then
5488 end Enclosing_Instance;
5490 --------------------------
5491 -- Is_Visible_Operation --
5492 --------------------------
5494 function Is_Visible_Operation (Op : Entity_Id) return Boolean is
5500 if Ekind (Op) /= E_Operator
5501 or else Scope (Op) /= Standard_Standard
5502 or else (In_Instance
5505 or else Present (Enclosing_Instance)))
5510 -- For a fixed point type operator, check the resulting type,
5511 -- because it may be a mixed mode integer * fixed operation.
5513 if Present (Next_Formal (First_Formal (New_S)))
5514 and then Is_Fixed_Point_Type (Etype (New_S))
5516 Typ := Etype (New_S);
5518 Typ := Etype (First_Formal (New_S));
5521 Btyp := Base_Type (Typ);
5523 if Nkind (Nam) /= N_Expanded_Name then
5524 return (In_Open_Scopes (Scope (Btyp))
5525 or else Is_Potentially_Use_Visible (Btyp)
5526 or else In_Use (Btyp)
5527 or else In_Use (Scope (Btyp)));
5530 Scop := Entity (Prefix (Nam));
5532 if Ekind (Scop) = E_Package
5533 and then Present (Renamed_Object (Scop))
5535 Scop := Renamed_Object (Scop);
5538 -- Operator is visible if prefix of expanded name denotes
5539 -- scope of type, or else type is defined in System_Aux
5540 -- and the prefix denotes System.
5542 return Scope (Btyp) = Scop
5543 or else (Scope (Btyp) = System_Aux_Id
5544 and then Scope (Scope (Btyp)) = Scop);
5547 end Is_Visible_Operation;
5553 function Within (Inner, Outer : Entity_Id) return Boolean is
5557 Sc := Scope (Inner);
5558 while Sc /= Standard_Standard loop
5569 ---------------------
5570 -- Report_Overload --
5571 ---------------------
5573 function Report_Overload return Entity_Id is
5576 Error_Msg_NE -- CODEFIX
5577 ("ambiguous actual subprogram&, " &
5578 "possible interpretations:", N, Nam);
5580 Error_Msg_N -- CODEFIX
5581 ("ambiguous subprogram, " &
5582 "possible interpretations:", N);
5585 List_Interps (Nam, N);
5587 end Report_Overload;
5589 -- Start of processing for Find_Renamed_Entity
5593 Candidate_Renaming := Empty;
5595 if not Is_Overloaded (Nam) then
5596 if Entity_Matches_Spec (Entity (Nam), New_S) then
5597 Candidate_Renaming := New_S;
5599 if Is_Visible_Operation (Entity (Nam)) then
5600 Old_S := Entity (Nam);
5604 Present (First_Formal (Entity (Nam)))
5605 and then Present (First_Formal (New_S))
5606 and then (Base_Type (Etype (First_Formal (Entity (Nam))))
5607 = Base_Type (Etype (First_Formal (New_S))))
5609 Candidate_Renaming := Entity (Nam);
5613 Get_First_Interp (Nam, Ind, It);
5614 while Present (It.Nam) loop
5615 if Entity_Matches_Spec (It.Nam, New_S)
5616 and then Is_Visible_Operation (It.Nam)
5618 if Old_S /= Any_Id then
5620 -- Note: The call to Disambiguate only happens if a
5621 -- previous interpretation was found, in which case I1
5622 -- has received a value.
5624 It1 := Disambiguate (Nam, I1, Ind, Etype (Old_S));
5626 if It1 = No_Interp then
5627 Inst := Enclosing_Instance;
5629 if Present (Inst) then
5630 if Within (It.Nam, Inst) then
5631 if Within (Old_S, Inst) then
5633 -- Choose the innermost subprogram, which would
5634 -- have hidden the outer one in the generic.
5636 if Scope_Depth (It.Nam) <
5645 elsif Within (Old_S, Inst) then
5649 return Report_Overload;
5652 -- If not within an instance, ambiguity is real
5655 return Report_Overload;
5669 Present (First_Formal (It.Nam))
5670 and then Present (First_Formal (New_S))
5671 and then (Base_Type (Etype (First_Formal (It.Nam)))
5672 = Base_Type (Etype (First_Formal (New_S))))
5674 Candidate_Renaming := It.Nam;
5677 Get_Next_Interp (Ind, It);
5680 Set_Entity (Nam, Old_S);
5682 if Old_S /= Any_Id then
5683 Set_Is_Overloaded (Nam, False);
5688 end Find_Renamed_Entity;
5690 -----------------------------
5691 -- Find_Selected_Component --
5692 -----------------------------
5694 procedure Find_Selected_Component (N : Node_Id) is
5695 P : constant Node_Id := Prefix (N);
5698 -- Entity denoted by prefix
5708 if Nkind (P) = N_Error then
5712 -- Selector name cannot be a character literal or an operator symbol in
5713 -- SPARK, except for the operator symbol in a renaming.
5715 if Restriction_Check_Required (SPARK) then
5716 if Nkind (Selector_Name (N)) = N_Character_Literal then
5717 Check_SPARK_Restriction
5718 ("character literal cannot be prefixed", N);
5719 elsif Nkind (Selector_Name (N)) = N_Operator_Symbol
5720 and then Nkind (Parent (N)) /= N_Subprogram_Renaming_Declaration
5722 Check_SPARK_Restriction ("operator symbol cannot be prefixed", N);
5726 -- If the selector already has an entity, the node has been constructed
5727 -- in the course of expansion, and is known to be valid. Do not verify
5728 -- that it is defined for the type (it may be a private component used
5729 -- in the expansion of record equality).
5731 if Present (Entity (Selector_Name (N))) then
5733 or else Etype (N) = Any_Type
5736 Sel_Name : constant Node_Id := Selector_Name (N);
5737 Selector : constant Entity_Id := Entity (Sel_Name);
5741 Set_Etype (Sel_Name, Etype (Selector));
5743 if not Is_Entity_Name (P) then
5747 -- Build an actual subtype except for the first parameter
5748 -- of an init proc, where this actual subtype is by
5749 -- definition incorrect, since the object is uninitialized
5750 -- (and does not even have defined discriminants etc.)
5752 if Is_Entity_Name (P)
5753 and then Ekind (Entity (P)) = E_Function
5755 Nam := New_Copy (P);
5757 if Is_Overloaded (P) then
5758 Save_Interps (P, Nam);
5762 Make_Function_Call (Sloc (P), Name => Nam));
5764 Analyze_Selected_Component (N);
5767 elsif Ekind (Selector) = E_Component
5768 and then (not Is_Entity_Name (P)
5769 or else Chars (Entity (P)) /= Name_uInit)
5771 -- Do not build the subtype when referencing components of
5772 -- dispatch table wrappers. Required to avoid generating
5773 -- elaboration code with HI runtimes. JVM and .NET use a
5774 -- modified version of Ada.Tags which does not contain RE_
5775 -- Dispatch_Table_Wrapper and RE_No_Dispatch_Table_Wrapper.
5776 -- Avoid raising RE_Not_Available exception in those cases.
5778 if VM_Target = No_VM
5779 and then RTU_Loaded (Ada_Tags)
5781 ((RTE_Available (RE_Dispatch_Table_Wrapper)
5782 and then Scope (Selector) =
5783 RTE (RE_Dispatch_Table_Wrapper))
5785 (RTE_Available (RE_No_Dispatch_Table_Wrapper)
5786 and then Scope (Selector) =
5787 RTE (RE_No_Dispatch_Table_Wrapper)))
5793 Build_Actual_Subtype_Of_Component
5794 (Etype (Selector), N);
5801 if No (C_Etype) then
5802 C_Etype := Etype (Selector);
5804 Insert_Action (N, C_Etype);
5805 C_Etype := Defining_Identifier (C_Etype);
5808 Set_Etype (N, C_Etype);
5811 -- If this is the name of an entry or protected operation, and
5812 -- the prefix is an access type, insert an explicit dereference,
5813 -- so that entry calls are treated uniformly.
5815 if Is_Access_Type (Etype (P))
5816 and then Is_Concurrent_Type (Designated_Type (Etype (P)))
5819 New_P : constant Node_Id :=
5820 Make_Explicit_Dereference (Sloc (P),
5821 Prefix => Relocate_Node (P));
5824 Set_Etype (P, Designated_Type (Etype (Prefix (P))));
5828 -- If the selected component appears within a default expression
5829 -- and it has an actual subtype, the pre-analysis has not yet
5830 -- completed its analysis, because Insert_Actions is disabled in
5831 -- that context. Within the init proc of the enclosing type we
5832 -- must complete this analysis, if an actual subtype was created.
5834 elsif Inside_Init_Proc then
5836 Typ : constant Entity_Id := Etype (N);
5837 Decl : constant Node_Id := Declaration_Node (Typ);
5839 if Nkind (Decl) = N_Subtype_Declaration
5840 and then not Analyzed (Decl)
5841 and then Is_List_Member (Decl)
5842 and then No (Parent (Decl))
5845 Insert_Action (N, Decl);
5852 elsif Is_Entity_Name (P) then
5853 P_Name := Entity (P);
5855 -- The prefix may denote an enclosing type which is the completion
5856 -- of an incomplete type declaration.
5858 if Is_Type (P_Name) then
5859 Set_Entity (P, Get_Full_View (P_Name));
5860 Set_Etype (P, Entity (P));
5861 P_Name := Entity (P);
5864 P_Type := Base_Type (Etype (P));
5866 if Debug_Flag_E then
5867 Write_Str ("Found prefix type to be ");
5868 Write_Entity_Info (P_Type, " "); Write_Eol;
5871 -- First check for components of a record object (not the
5872 -- result of a call, which is handled below).
5874 if Is_Appropriate_For_Record (P_Type)
5875 and then not Is_Overloadable (P_Name)
5876 and then not Is_Type (P_Name)
5878 -- Selected component of record. Type checking will validate
5879 -- name of selector.
5880 -- ??? could we rewrite an implicit dereference into an explicit
5883 Analyze_Selected_Component (N);
5885 -- Reference to type name in predicate/invariant expression
5887 elsif Is_Appropriate_For_Entry_Prefix (P_Type)
5888 and then not In_Open_Scopes (P_Name)
5889 and then (not Is_Concurrent_Type (Etype (P_Name))
5890 or else not In_Open_Scopes (Etype (P_Name)))
5892 -- Call to protected operation or entry. Type checking is
5893 -- needed on the prefix.
5895 Analyze_Selected_Component (N);
5897 elsif (In_Open_Scopes (P_Name)
5898 and then Ekind (P_Name) /= E_Void
5899 and then not Is_Overloadable (P_Name))
5900 or else (Is_Concurrent_Type (Etype (P_Name))
5901 and then In_Open_Scopes (Etype (P_Name)))
5903 -- Prefix denotes an enclosing loop, block, or task, i.e. an
5904 -- enclosing construct that is not a subprogram or accept.
5906 Find_Expanded_Name (N);
5908 elsif Ekind (P_Name) = E_Package then
5909 Find_Expanded_Name (N);
5911 elsif Is_Overloadable (P_Name) then
5913 -- The subprogram may be a renaming (of an enclosing scope) as
5914 -- in the case of the name of the generic within an instantiation.
5916 if Ekind_In (P_Name, E_Procedure, E_Function)
5917 and then Present (Alias (P_Name))
5918 and then Is_Generic_Instance (Alias (P_Name))
5920 P_Name := Alias (P_Name);
5923 if Is_Overloaded (P) then
5925 -- The prefix must resolve to a unique enclosing construct
5928 Found : Boolean := False;
5933 Get_First_Interp (P, Ind, It);
5934 while Present (It.Nam) loop
5935 if In_Open_Scopes (It.Nam) then
5938 "prefix must be unique enclosing scope", N);
5939 Set_Entity (N, Any_Id);
5940 Set_Etype (N, Any_Type);
5949 Get_Next_Interp (Ind, It);
5954 if In_Open_Scopes (P_Name) then
5955 Set_Entity (P, P_Name);
5956 Set_Is_Overloaded (P, False);
5957 Find_Expanded_Name (N);
5960 -- If no interpretation as an expanded name is possible, it
5961 -- must be a selected component of a record returned by a
5962 -- function call. Reformat prefix as a function call, the rest
5963 -- is done by type resolution. If the prefix is procedure or
5964 -- entry, as is P.X; this is an error.
5966 if Ekind (P_Name) /= E_Function
5967 and then (not Is_Overloaded (P)
5969 Nkind (Parent (N)) = N_Procedure_Call_Statement)
5971 -- Prefix may mention a package that is hidden by a local
5972 -- declaration: let the user know. Scan the full homonym
5973 -- chain, the candidate package may be anywhere on it.
5975 if Present (Homonym (Current_Entity (P_Name))) then
5977 P_Name := Current_Entity (P_Name);
5979 while Present (P_Name) loop
5980 exit when Ekind (P_Name) = E_Package;
5981 P_Name := Homonym (P_Name);
5984 if Present (P_Name) then
5985 Error_Msg_Sloc := Sloc (Entity (Prefix (N)));
5988 ("package& is hidden by declaration#",
5991 Set_Entity (Prefix (N), P_Name);
5992 Find_Expanded_Name (N);
5995 P_Name := Entity (Prefix (N));
6000 ("invalid prefix in selected component&", N, P_Name);
6001 Change_Selected_Component_To_Expanded_Name (N);
6002 Set_Entity (N, Any_Id);
6003 Set_Etype (N, Any_Type);
6006 Nam := New_Copy (P);
6007 Save_Interps (P, Nam);
6009 Make_Function_Call (Sloc (P), Name => Nam));
6011 Analyze_Selected_Component (N);
6015 -- Remaining cases generate various error messages
6018 -- Format node as expanded name, to avoid cascaded errors
6020 Change_Selected_Component_To_Expanded_Name (N);
6021 Set_Entity (N, Any_Id);
6022 Set_Etype (N, Any_Type);
6024 -- Issue error message, but avoid this if error issued already.
6025 -- Use identifier of prefix if one is available.
6027 if P_Name = Any_Id then
6030 elsif Ekind (P_Name) = E_Void then
6031 Premature_Usage (P);
6033 elsif Nkind (P) /= N_Attribute_Reference then
6035 "invalid prefix in selected component&", P);
6037 if Is_Access_Type (P_Type)
6038 and then Ekind (Designated_Type (P_Type)) = E_Incomplete_Type
6041 ("\dereference must not be of an incomplete type " &
6047 "invalid prefix in selected component", P);
6051 -- Selector name is restricted in SPARK
6053 if Nkind (N) = N_Expanded_Name
6054 and then Restriction_Check_Required (SPARK)
6056 if Is_Subprogram (P_Name) then
6057 Check_SPARK_Restriction
6058 ("prefix of expanded name cannot be a subprogram", P);
6059 elsif Ekind (P_Name) = E_Loop then
6060 Check_SPARK_Restriction
6061 ("prefix of expanded name cannot be a loop statement", P);
6066 -- If prefix is not the name of an entity, it must be an expression,
6067 -- whose type is appropriate for a record. This is determined by
6070 Analyze_Selected_Component (N);
6072 end Find_Selected_Component;
6078 procedure Find_Type (N : Node_Id) is
6088 elsif Nkind (N) = N_Attribute_Reference then
6090 -- Class attribute. This is not valid in Ada 83 mode, but we do not
6091 -- need to enforce that at this point, since the declaration of the
6092 -- tagged type in the prefix would have been flagged already.
6094 if Attribute_Name (N) = Name_Class then
6095 Check_Restriction (No_Dispatch, N);
6096 Find_Type (Prefix (N));
6098 -- Propagate error from bad prefix
6100 if Etype (Prefix (N)) = Any_Type then
6101 Set_Entity (N, Any_Type);
6102 Set_Etype (N, Any_Type);
6106 T := Base_Type (Entity (Prefix (N)));
6108 -- Case where type is not known to be tagged. Its appearance in
6109 -- the prefix of the 'Class attribute indicates that the full view
6112 if not Is_Tagged_Type (T) then
6113 if Ekind (T) = E_Incomplete_Type then
6115 -- It is legal to denote the class type of an incomplete
6116 -- type. The full type will have to be tagged, of course.
6117 -- In Ada 2005 this usage is declared obsolescent, so we
6118 -- warn accordingly. This usage is only legal if the type
6119 -- is completed in the current scope, and not for a limited
6122 if Ada_Version >= Ada_2005 then
6124 -- Test whether the Available_View of a limited type view
6125 -- is tagged, since the limited view may not be marked as
6126 -- tagged if the type itself has an untagged incomplete
6127 -- type view in its package.
6129 if From_With_Type (T)
6130 and then not Is_Tagged_Type (Available_View (T))
6133 ("prefix of Class attribute must be tagged", N);
6134 Set_Etype (N, Any_Type);
6135 Set_Entity (N, Any_Type);
6138 -- ??? This test is temporarily disabled (always False)
6139 -- because it causes an unwanted warning on GNAT sources
6140 -- (built with -gnatg, which includes Warn_On_Obsolescent_
6141 -- Feature). Once this issue is cleared in the sources, it
6144 elsif Warn_On_Obsolescent_Feature
6148 ("applying 'Class to an untagged incomplete type"
6149 & " is an obsolescent feature (RM J.11)", N);
6153 Set_Is_Tagged_Type (T);
6154 Set_Direct_Primitive_Operations (T, New_Elmt_List);
6155 Make_Class_Wide_Type (T);
6156 Set_Entity (N, Class_Wide_Type (T));
6157 Set_Etype (N, Class_Wide_Type (T));
6159 elsif Ekind (T) = E_Private_Type
6160 and then not Is_Generic_Type (T)
6161 and then In_Private_Part (Scope (T))
6163 -- The Class attribute can be applied to an untagged private
6164 -- type fulfilled by a tagged type prior to the full type
6165 -- declaration (but only within the parent package's private
6166 -- part). Create the class-wide type now and check that the
6167 -- full type is tagged later during its analysis. Note that
6168 -- we do not mark the private type as tagged, unlike the
6169 -- case of incomplete types, because the type must still
6170 -- appear untagged to outside units.
6172 if No (Class_Wide_Type (T)) then
6173 Make_Class_Wide_Type (T);
6176 Set_Entity (N, Class_Wide_Type (T));
6177 Set_Etype (N, Class_Wide_Type (T));
6180 -- Should we introduce a type Any_Tagged and use Wrong_Type
6181 -- here, it would be a bit more consistent???
6184 ("tagged type required, found}",
6185 Prefix (N), First_Subtype (T));
6186 Set_Entity (N, Any_Type);
6190 -- Case of tagged type
6193 if Is_Concurrent_Type (T) then
6194 if No (Corresponding_Record_Type (Entity (Prefix (N)))) then
6196 -- Previous error. Use current type, which at least
6197 -- provides some operations.
6199 C := Entity (Prefix (N));
6202 C := Class_Wide_Type
6203 (Corresponding_Record_Type (Entity (Prefix (N))));
6207 C := Class_Wide_Type (Entity (Prefix (N)));
6210 Set_Entity_With_Style_Check (N, C);
6211 Generate_Reference (C, N);
6215 -- Base attribute, not allowed in Ada 83
6217 elsif Attribute_Name (N) = Name_Base then
6218 Error_Msg_Name_1 := Name_Base;
6219 Check_SPARK_Restriction
6220 ("attribute% is only allowed as prefix of another attribute", N);
6222 if Ada_Version = Ada_83 and then Comes_From_Source (N) then
6224 ("(Ada 83) Base attribute not allowed in subtype mark", N);
6227 Find_Type (Prefix (N));
6228 Typ := Entity (Prefix (N));
6230 if Ada_Version >= Ada_95
6231 and then not Is_Scalar_Type (Typ)
6232 and then not Is_Generic_Type (Typ)
6235 ("prefix of Base attribute must be scalar type",
6238 elsif Warn_On_Redundant_Constructs
6239 and then Base_Type (Typ) = Typ
6241 Error_Msg_NE -- CODEFIX
6242 ("?redundant attribute, & is its own base type", N, Typ);
6245 T := Base_Type (Typ);
6247 -- Rewrite attribute reference with type itself (see similar
6248 -- processing in Analyze_Attribute, case Base). Preserve prefix
6249 -- if present, for other legality checks.
6251 if Nkind (Prefix (N)) = N_Expanded_Name then
6253 Make_Expanded_Name (Sloc (N),
6255 Prefix => New_Copy (Prefix (Prefix (N))),
6256 Selector_Name => New_Reference_To (T, Sloc (N))));
6259 Rewrite (N, New_Reference_To (T, Sloc (N)));
6266 elsif Attribute_Name (N) = Name_Stub_Type then
6268 -- This is handled in Analyze_Attribute
6272 -- All other attributes are invalid in a subtype mark
6275 Error_Msg_N ("invalid attribute in subtype mark", N);
6281 if Is_Entity_Name (N) then
6282 T_Name := Entity (N);
6284 Error_Msg_N ("subtype mark required in this context", N);
6285 Set_Etype (N, Any_Type);
6289 if T_Name = Any_Id or else Etype (N) = Any_Type then
6291 -- Undefined id. Make it into a valid type
6293 Set_Entity (N, Any_Type);
6295 elsif not Is_Type (T_Name)
6296 and then T_Name /= Standard_Void_Type
6298 Error_Msg_Sloc := Sloc (T_Name);
6299 Error_Msg_N ("subtype mark required in this context", N);
6300 Error_Msg_NE ("\\found & declared#", N, T_Name);
6301 Set_Entity (N, Any_Type);
6304 -- If the type is an incomplete type created to handle
6305 -- anonymous access components of a record type, then the
6306 -- incomplete type is the visible entity and subsequent
6307 -- references will point to it. Mark the original full
6308 -- type as referenced, to prevent spurious warnings.
6310 if Is_Incomplete_Type (T_Name)
6311 and then Present (Full_View (T_Name))
6312 and then not Comes_From_Source (T_Name)
6314 Set_Referenced (Full_View (T_Name));
6317 T_Name := Get_Full_View (T_Name);
6319 -- Ada 2005 (AI-251, AI-50217): Handle interfaces visible through
6320 -- limited-with clauses
6322 if From_With_Type (T_Name)
6323 and then Ekind (T_Name) in Incomplete_Kind
6324 and then Present (Non_Limited_View (T_Name))
6325 and then Is_Interface (Non_Limited_View (T_Name))
6327 T_Name := Non_Limited_View (T_Name);
6330 if In_Open_Scopes (T_Name) then
6331 if Ekind (Base_Type (T_Name)) = E_Task_Type then
6333 -- In Ada 2005, a task name can be used in an access
6334 -- definition within its own body. It cannot be used
6335 -- in the discriminant part of the task declaration,
6336 -- nor anywhere else in the declaration because entries
6337 -- cannot have access parameters.
6339 if Ada_Version >= Ada_2005
6340 and then Nkind (Parent (N)) = N_Access_Definition
6342 Set_Entity (N, T_Name);
6343 Set_Etype (N, T_Name);
6345 if Has_Completion (T_Name) then
6350 ("task type cannot be used as type mark " &
6351 "within its own declaration", N);
6356 ("task type cannot be used as type mark " &
6357 "within its own spec or body", N);
6360 elsif Ekind (Base_Type (T_Name)) = E_Protected_Type then
6362 -- In Ada 2005, a protected name can be used in an access
6363 -- definition within its own body.
6365 if Ada_Version >= Ada_2005
6366 and then Nkind (Parent (N)) = N_Access_Definition
6368 Set_Entity (N, T_Name);
6369 Set_Etype (N, T_Name);
6374 ("protected type cannot be used as type mark " &
6375 "within its own spec or body", N);
6379 Error_Msg_N ("type declaration cannot refer to itself", N);
6382 Set_Etype (N, Any_Type);
6383 Set_Entity (N, Any_Type);
6384 Set_Error_Posted (T_Name);
6388 Set_Entity (N, T_Name);
6389 Set_Etype (N, T_Name);
6393 if Present (Etype (N)) and then Comes_From_Source (N) then
6394 if Is_Fixed_Point_Type (Etype (N)) then
6395 Check_Restriction (No_Fixed_Point, N);
6396 elsif Is_Floating_Point_Type (Etype (N)) then
6397 Check_Restriction (No_Floating_Point, N);
6402 ------------------------------------
6403 -- Has_Implicit_Character_Literal --
6404 ------------------------------------
6406 function Has_Implicit_Character_Literal (N : Node_Id) return Boolean is
6408 Found : Boolean := False;
6409 P : constant Entity_Id := Entity (Prefix (N));
6410 Priv_Id : Entity_Id := Empty;
6413 if Ekind (P) = E_Package
6414 and then not In_Open_Scopes (P)
6416 Priv_Id := First_Private_Entity (P);
6419 if P = Standard_Standard then
6420 Change_Selected_Component_To_Expanded_Name (N);
6421 Rewrite (N, Selector_Name (N));
6423 Set_Etype (Original_Node (N), Standard_Character);
6427 Id := First_Entity (P);
6429 and then Id /= Priv_Id
6431 if Is_Standard_Character_Type (Id) and then Is_Base_Type (Id) then
6433 -- We replace the node with the literal itself, resolve as a
6434 -- character, and set the type correctly.
6437 Change_Selected_Component_To_Expanded_Name (N);
6438 Rewrite (N, Selector_Name (N));
6441 Set_Etype (Original_Node (N), Id);
6445 -- More than one type derived from Character in given scope.
6446 -- Collect all possible interpretations.
6448 Add_One_Interp (N, Id, Id);
6456 end Has_Implicit_Character_Literal;
6458 ----------------------
6459 -- Has_Private_With --
6460 ----------------------
6462 function Has_Private_With (E : Entity_Id) return Boolean is
6463 Comp_Unit : constant Node_Id := Cunit (Current_Sem_Unit);
6467 Item := First (Context_Items (Comp_Unit));
6468 while Present (Item) loop
6469 if Nkind (Item) = N_With_Clause
6470 and then Private_Present (Item)
6471 and then Entity (Name (Item)) = E
6480 end Has_Private_With;
6482 ---------------------------
6483 -- Has_Implicit_Operator --
6484 ---------------------------
6486 function Has_Implicit_Operator (N : Node_Id) return Boolean is
6487 Op_Id : constant Name_Id := Chars (Selector_Name (N));
6488 P : constant Entity_Id := Entity (Prefix (N));
6490 Priv_Id : Entity_Id := Empty;
6492 procedure Add_Implicit_Operator
6494 Op_Type : Entity_Id := Empty);
6495 -- Add implicit interpretation to node N, using the type for which a
6496 -- predefined operator exists. If the operator yields a boolean type,
6497 -- the Operand_Type is implicitly referenced by the operator, and a
6498 -- reference to it must be generated.
6500 ---------------------------
6501 -- Add_Implicit_Operator --
6502 ---------------------------
6504 procedure Add_Implicit_Operator
6506 Op_Type : Entity_Id := Empty)
6508 Predef_Op : Entity_Id;
6511 Predef_Op := Current_Entity (Selector_Name (N));
6513 while Present (Predef_Op)
6514 and then Scope (Predef_Op) /= Standard_Standard
6516 Predef_Op := Homonym (Predef_Op);
6519 if Nkind (N) = N_Selected_Component then
6520 Change_Selected_Component_To_Expanded_Name (N);
6523 -- If the context is an unanalyzed function call, determine whether
6524 -- a binary or unary interpretation is required.
6526 if Nkind (Parent (N)) = N_Indexed_Component then
6528 Is_Binary_Call : constant Boolean :=
6530 (Next (First (Expressions (Parent (N)))));
6531 Is_Binary_Op : constant Boolean :=
6533 (Predef_Op) /= Last_Entity (Predef_Op);
6534 Predef_Op2 : constant Entity_Id := Homonym (Predef_Op);
6537 if Is_Binary_Call then
6538 if Is_Binary_Op then
6539 Add_One_Interp (N, Predef_Op, T);
6541 Add_One_Interp (N, Predef_Op2, T);
6545 if not Is_Binary_Op then
6546 Add_One_Interp (N, Predef_Op, T);
6548 Add_One_Interp (N, Predef_Op2, T);
6554 Add_One_Interp (N, Predef_Op, T);
6556 -- For operators with unary and binary interpretations, if
6557 -- context is not a call, add both
6559 if Present (Homonym (Predef_Op)) then
6560 Add_One_Interp (N, Homonym (Predef_Op), T);
6564 -- The node is a reference to a predefined operator, and
6565 -- an implicit reference to the type of its operands.
6567 if Present (Op_Type) then
6568 Generate_Operator_Reference (N, Op_Type);
6570 Generate_Operator_Reference (N, T);
6572 end Add_Implicit_Operator;
6574 -- Start of processing for Has_Implicit_Operator
6577 if Ekind (P) = E_Package
6578 and then not In_Open_Scopes (P)
6580 Priv_Id := First_Private_Entity (P);
6583 Id := First_Entity (P);
6587 -- Boolean operators: an implicit declaration exists if the scope
6588 -- contains a declaration for a derived Boolean type, or for an
6589 -- array of Boolean type.
6591 when Name_Op_And | Name_Op_Not | Name_Op_Or | Name_Op_Xor =>
6592 while Id /= Priv_Id loop
6593 if Valid_Boolean_Arg (Id) and then Is_Base_Type (Id) then
6594 Add_Implicit_Operator (Id);
6601 -- Equality: look for any non-limited type (result is Boolean)
6603 when Name_Op_Eq | Name_Op_Ne =>
6604 while Id /= Priv_Id loop
6606 and then not Is_Limited_Type (Id)
6607 and then Is_Base_Type (Id)
6609 Add_Implicit_Operator (Standard_Boolean, Id);
6616 -- Comparison operators: scalar type, or array of scalar
6618 when Name_Op_Lt | Name_Op_Le | Name_Op_Gt | Name_Op_Ge =>
6619 while Id /= Priv_Id loop
6620 if (Is_Scalar_Type (Id)
6621 or else (Is_Array_Type (Id)
6622 and then Is_Scalar_Type (Component_Type (Id))))
6623 and then Is_Base_Type (Id)
6625 Add_Implicit_Operator (Standard_Boolean, Id);
6632 -- Arithmetic operators: any numeric type
6642 while Id /= Priv_Id loop
6643 if Is_Numeric_Type (Id) and then Is_Base_Type (Id) then
6644 Add_Implicit_Operator (Id);
6651 -- Concatenation: any one-dimensional array type
6653 when Name_Op_Concat =>
6654 while Id /= Priv_Id loop
6655 if Is_Array_Type (Id)
6656 and then Number_Dimensions (Id) = 1
6657 and then Is_Base_Type (Id)
6659 Add_Implicit_Operator (Id);
6666 -- What is the others condition here? Should we be using a
6667 -- subtype of Name_Id that would restrict to operators ???
6669 when others => null;
6672 -- If we fall through, then we do not have an implicit operator
6676 end Has_Implicit_Operator;
6678 -----------------------------------
6679 -- Has_Loop_In_Inner_Open_Scopes --
6680 -----------------------------------
6682 function Has_Loop_In_Inner_Open_Scopes (S : Entity_Id) return Boolean is
6684 -- Several scope stacks are maintained by Scope_Stack. The base of the
6685 -- currently active scope stack is denoted by the Is_Active_Stack_Base
6686 -- flag in the scope stack entry. Note that the scope stacks used to
6687 -- simply be delimited implicitly by the presence of Standard_Standard
6688 -- at their base, but there now are cases where this is not sufficient
6689 -- because Standard_Standard actually may appear in the middle of the
6690 -- active set of scopes.
6692 for J in reverse 0 .. Scope_Stack.Last loop
6694 -- S was reached without seing a loop scope first
6696 if Scope_Stack.Table (J).Entity = S then
6699 -- S was not yet reached, so it contains at least one inner loop
6701 elsif Ekind (Scope_Stack.Table (J).Entity) = E_Loop then
6705 -- Check Is_Active_Stack_Base to tell us when to stop, as there are
6706 -- cases where Standard_Standard appears in the middle of the active
6707 -- set of scopes. This affects the declaration and overriding of
6708 -- private inherited operations in instantiations of generic child
6711 pragma Assert (not Scope_Stack.Table (J).Is_Active_Stack_Base);
6714 raise Program_Error; -- unreachable
6715 end Has_Loop_In_Inner_Open_Scopes;
6717 --------------------
6718 -- In_Open_Scopes --
6719 --------------------
6721 function In_Open_Scopes (S : Entity_Id) return Boolean is
6723 -- Several scope stacks are maintained by Scope_Stack. The base of the
6724 -- currently active scope stack is denoted by the Is_Active_Stack_Base
6725 -- flag in the scope stack entry. Note that the scope stacks used to
6726 -- simply be delimited implicitly by the presence of Standard_Standard
6727 -- at their base, but there now are cases where this is not sufficient
6728 -- because Standard_Standard actually may appear in the middle of the
6729 -- active set of scopes.
6731 for J in reverse 0 .. Scope_Stack.Last loop
6732 if Scope_Stack.Table (J).Entity = S then
6736 -- Check Is_Active_Stack_Base to tell us when to stop, as there are
6737 -- cases where Standard_Standard appears in the middle of the active
6738 -- set of scopes. This affects the declaration and overriding of
6739 -- private inherited operations in instantiations of generic child
6742 exit when Scope_Stack.Table (J).Is_Active_Stack_Base;
6748 -----------------------------
6749 -- Inherit_Renamed_Profile --
6750 -----------------------------
6752 procedure Inherit_Renamed_Profile (New_S : Entity_Id; Old_S : Entity_Id) is
6759 if Ekind (Old_S) = E_Operator then
6760 New_F := First_Formal (New_S);
6762 while Present (New_F) loop
6763 Set_Etype (New_F, Base_Type (Etype (New_F)));
6764 Next_Formal (New_F);
6767 Set_Etype (New_S, Base_Type (Etype (New_S)));
6770 New_F := First_Formal (New_S);
6771 Old_F := First_Formal (Old_S);
6773 while Present (New_F) loop
6774 New_T := Etype (New_F);
6775 Old_T := Etype (Old_F);
6777 -- If the new type is a renaming of the old one, as is the
6778 -- case for actuals in instances, retain its name, to simplify
6779 -- later disambiguation.
6781 if Nkind (Parent (New_T)) = N_Subtype_Declaration
6782 and then Is_Entity_Name (Subtype_Indication (Parent (New_T)))
6783 and then Entity (Subtype_Indication (Parent (New_T))) = Old_T
6787 Set_Etype (New_F, Old_T);
6790 Next_Formal (New_F);
6791 Next_Formal (Old_F);
6794 if Ekind_In (Old_S, E_Function, E_Enumeration_Literal) then
6795 Set_Etype (New_S, Etype (Old_S));
6798 end Inherit_Renamed_Profile;
6804 procedure Initialize is
6809 -------------------------
6810 -- Install_Use_Clauses --
6811 -------------------------
6813 procedure Install_Use_Clauses
6815 Force_Installation : Boolean := False)
6823 while Present (U) loop
6825 -- Case of USE package
6827 if Nkind (U) = N_Use_Package_Clause then
6828 P := First (Names (U));
6829 while Present (P) loop
6832 if Ekind (Id) = E_Package then
6834 Note_Redundant_Use (P);
6836 elsif Present (Renamed_Object (Id))
6837 and then In_Use (Renamed_Object (Id))
6839 Note_Redundant_Use (P);
6841 elsif Force_Installation or else Applicable_Use (P) then
6842 Use_One_Package (Id, U);
6853 P := First (Subtype_Marks (U));
6854 while Present (P) loop
6855 if not Is_Entity_Name (P)
6856 or else No (Entity (P))
6860 elsif Entity (P) /= Any_Type then
6868 Next_Use_Clause (U);
6870 end Install_Use_Clauses;
6872 -------------------------------------
6873 -- Is_Appropriate_For_Entry_Prefix --
6874 -------------------------------------
6876 function Is_Appropriate_For_Entry_Prefix (T : Entity_Id) return Boolean is
6877 P_Type : Entity_Id := T;
6880 if Is_Access_Type (P_Type) then
6881 P_Type := Designated_Type (P_Type);
6884 return Is_Task_Type (P_Type) or else Is_Protected_Type (P_Type);
6885 end Is_Appropriate_For_Entry_Prefix;
6887 -------------------------------
6888 -- Is_Appropriate_For_Record --
6889 -------------------------------
6891 function Is_Appropriate_For_Record (T : Entity_Id) return Boolean is
6893 function Has_Components (T1 : Entity_Id) return Boolean;
6894 -- Determine if given type has components (i.e. is either a record
6895 -- type or a type that has discriminants).
6897 --------------------
6898 -- Has_Components --
6899 --------------------
6901 function Has_Components (T1 : Entity_Id) return Boolean is
6903 return Is_Record_Type (T1)
6904 or else (Is_Private_Type (T1) and then Has_Discriminants (T1))
6905 or else (Is_Task_Type (T1) and then Has_Discriminants (T1))
6906 or else (Is_Incomplete_Type (T1)
6907 and then From_With_Type (T1)
6908 and then Present (Non_Limited_View (T1))
6909 and then Is_Record_Type
6910 (Get_Full_View (Non_Limited_View (T1))));
6913 -- Start of processing for Is_Appropriate_For_Record
6918 and then (Has_Components (T)
6919 or else (Is_Access_Type (T)
6920 and then Has_Components (Designated_Type (T))));
6921 end Is_Appropriate_For_Record;
6923 ------------------------
6924 -- Note_Redundant_Use --
6925 ------------------------
6927 procedure Note_Redundant_Use (Clause : Node_Id) is
6928 Pack_Name : constant Entity_Id := Entity (Clause);
6929 Cur_Use : constant Node_Id := Current_Use_Clause (Pack_Name);
6930 Decl : constant Node_Id := Parent (Clause);
6932 Prev_Use : Node_Id := Empty;
6933 Redundant : Node_Id := Empty;
6934 -- The Use_Clause which is actually redundant. In the simplest case it
6935 -- is Pack itself, but when we compile a body we install its context
6936 -- before that of its spec, in which case it is the use_clause in the
6937 -- spec that will appear to be redundant, and we want the warning to be
6938 -- placed on the body. Similar complications appear when the redundancy
6939 -- is between a child unit and one of its ancestors.
6942 Set_Redundant_Use (Clause, True);
6944 if not Comes_From_Source (Clause)
6946 or else not Warn_On_Redundant_Constructs
6951 if not Is_Compilation_Unit (Current_Scope) then
6953 -- If the use_clause is in an inner scope, it is made redundant by
6954 -- some clause in the current context, with one exception: If we're
6955 -- compiling a nested package body, and the use_clause comes from the
6956 -- corresponding spec, the clause is not necessarily fully redundant,
6957 -- so we should not warn. If a warning was warranted, it would have
6958 -- been given when the spec was processed.
6960 if Nkind (Parent (Decl)) = N_Package_Specification then
6962 Package_Spec_Entity : constant Entity_Id :=
6963 Defining_Unit_Name (Parent (Decl));
6965 if In_Package_Body (Package_Spec_Entity) then
6971 Redundant := Clause;
6972 Prev_Use := Cur_Use;
6974 elsif Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Body then
6976 Cur_Unit : constant Unit_Number_Type := Get_Source_Unit (Cur_Use);
6977 New_Unit : constant Unit_Number_Type := Get_Source_Unit (Clause);
6981 if Cur_Unit = New_Unit then
6983 -- Redundant clause in same body
6985 Redundant := Clause;
6986 Prev_Use := Cur_Use;
6988 elsif Cur_Unit = Current_Sem_Unit then
6990 -- If the new clause is not in the current unit it has been
6991 -- analyzed first, and it makes the other one redundant.
6992 -- However, if the new clause appears in a subunit, Cur_Unit
6993 -- is still the parent, and in that case the redundant one
6994 -- is the one appearing in the subunit.
6996 if Nkind (Unit (Cunit (New_Unit))) = N_Subunit then
6997 Redundant := Clause;
6998 Prev_Use := Cur_Use;
7000 -- Most common case: redundant clause in body,
7001 -- original clause in spec. Current scope is spec entity.
7006 Unit (Library_Unit (Cunit (Current_Sem_Unit))))
7008 Redundant := Cur_Use;
7012 -- The new clause may appear in an unrelated unit, when
7013 -- the parents of a generic are being installed prior to
7014 -- instantiation. In this case there must be no warning.
7015 -- We detect this case by checking whether the current top
7016 -- of the stack is related to the current compilation.
7018 Scop := Current_Scope;
7019 while Present (Scop)
7020 and then Scop /= Standard_Standard
7022 if Is_Compilation_Unit (Scop)
7023 and then not Is_Child_Unit (Scop)
7027 elsif Scop = Cunit_Entity (Current_Sem_Unit) then
7031 Scop := Scope (Scop);
7034 Redundant := Cur_Use;
7038 elsif New_Unit = Current_Sem_Unit then
7039 Redundant := Clause;
7040 Prev_Use := Cur_Use;
7043 -- Neither is the current unit, so they appear in parent or
7044 -- sibling units. Warning will be emitted elsewhere.
7050 elsif Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Declaration
7051 and then Present (Parent_Spec (Unit (Cunit (Current_Sem_Unit))))
7053 -- Use_clause is in child unit of current unit, and the child unit
7054 -- appears in the context of the body of the parent, so it has been
7055 -- installed first, even though it is the redundant one. Depending on
7056 -- their placement in the context, the visible or the private parts
7057 -- of the two units, either might appear as redundant, but the
7058 -- message has to be on the current unit.
7060 if Get_Source_Unit (Cur_Use) = Current_Sem_Unit then
7061 Redundant := Cur_Use;
7064 Redundant := Clause;
7065 Prev_Use := Cur_Use;
7068 -- If the new use clause appears in the private part of a parent unit
7069 -- it may appear to be redundant w.r.t. a use clause in a child unit,
7070 -- but the previous use clause was needed in the visible part of the
7071 -- child, and no warning should be emitted.
7073 if Nkind (Parent (Decl)) = N_Package_Specification
7075 List_Containing (Decl) = Private_Declarations (Parent (Decl))
7078 Par : constant Entity_Id := Defining_Entity (Parent (Decl));
7079 Spec : constant Node_Id :=
7080 Specification (Unit (Cunit (Current_Sem_Unit)));
7083 if Is_Compilation_Unit (Par)
7084 and then Par /= Cunit_Entity (Current_Sem_Unit)
7085 and then Parent (Cur_Use) = Spec
7087 List_Containing (Cur_Use) = Visible_Declarations (Spec)
7094 -- Finally, if the current use clause is in the context then
7095 -- the clause is redundant when it is nested within the unit.
7097 elsif Nkind (Parent (Cur_Use)) = N_Compilation_Unit
7098 and then Nkind (Parent (Parent (Clause))) /= N_Compilation_Unit
7099 and then Get_Source_Unit (Cur_Use) = Get_Source_Unit (Clause)
7101 Redundant := Clause;
7102 Prev_Use := Cur_Use;
7108 if Present (Redundant) then
7109 Error_Msg_Sloc := Sloc (Prev_Use);
7110 Error_Msg_NE -- CODEFIX
7111 ("& is already use-visible through previous use clause #?",
7112 Redundant, Pack_Name);
7114 end Note_Redundant_Use;
7120 procedure Pop_Scope is
7121 SST : Scope_Stack_Entry renames Scope_Stack.Table (Scope_Stack.Last);
7122 S : constant Entity_Id := SST.Entity;
7125 if Debug_Flag_E then
7129 -- Set Default_Storage_Pool field of the library unit if necessary
7131 if Ekind_In (S, E_Package, E_Generic_Package)
7133 Nkind (Parent (Unit_Declaration_Node (S))) = N_Compilation_Unit
7136 Aux : constant Node_Id :=
7137 Aux_Decls_Node (Parent (Unit_Declaration_Node (S)));
7139 if No (Default_Storage_Pool (Aux)) then
7140 Set_Default_Storage_Pool (Aux, Default_Pool);
7145 Scope_Suppress := SST.Save_Scope_Suppress;
7146 Local_Suppress_Stack_Top := SST.Save_Local_Suppress_Stack_Top;
7147 Check_Policy_List := SST.Save_Check_Policy_List;
7148 Default_Pool := SST.Save_Default_Storage_Pool;
7150 if Debug_Flag_W then
7151 Write_Str ("<-- exiting scope: ");
7152 Write_Name (Chars (Current_Scope));
7153 Write_Str (", Depth=");
7154 Write_Int (Int (Scope_Stack.Last));
7158 End_Use_Clauses (SST.First_Use_Clause);
7160 -- If the actions to be wrapped are still there they will get lost
7161 -- causing incomplete code to be generated. It is better to abort in
7162 -- this case (and we do the abort even with assertions off since the
7163 -- penalty is incorrect code generation)
7165 if SST.Actions_To_Be_Wrapped_Before /= No_List
7167 SST.Actions_To_Be_Wrapped_After /= No_List
7169 raise Program_Error;
7172 -- Free last subprogram name if allocated, and pop scope
7174 Free (SST.Last_Subprogram_Name);
7175 Scope_Stack.Decrement_Last;
7182 procedure Push_Scope (S : Entity_Id) is
7183 E : constant Entity_Id := Scope (S);
7186 if Ekind (S) = E_Void then
7189 -- Set scope depth if not a non-concurrent type, and we have not yet set
7190 -- the scope depth. This means that we have the first occurrence of the
7191 -- scope, and this is where the depth is set.
7193 elsif (not Is_Type (S) or else Is_Concurrent_Type (S))
7194 and then not Scope_Depth_Set (S)
7196 if S = Standard_Standard then
7197 Set_Scope_Depth_Value (S, Uint_0);
7199 elsif Is_Child_Unit (S) then
7200 Set_Scope_Depth_Value (S, Uint_1);
7202 elsif not Is_Record_Type (Current_Scope) then
7203 if Ekind (S) = E_Loop then
7204 Set_Scope_Depth_Value (S, Scope_Depth (Current_Scope));
7206 Set_Scope_Depth_Value (S, Scope_Depth (Current_Scope) + 1);
7211 Scope_Stack.Increment_Last;
7214 SST : Scope_Stack_Entry renames Scope_Stack.Table (Scope_Stack.Last);
7218 SST.Save_Scope_Suppress := Scope_Suppress;
7219 SST.Save_Local_Suppress_Stack_Top := Local_Suppress_Stack_Top;
7220 SST.Save_Check_Policy_List := Check_Policy_List;
7221 SST.Save_Default_Storage_Pool := Default_Pool;
7223 if Scope_Stack.Last > Scope_Stack.First then
7224 SST.Component_Alignment_Default := Scope_Stack.Table
7225 (Scope_Stack.Last - 1).
7226 Component_Alignment_Default;
7229 SST.Last_Subprogram_Name := null;
7230 SST.Is_Transient := False;
7231 SST.Node_To_Be_Wrapped := Empty;
7232 SST.Pending_Freeze_Actions := No_List;
7233 SST.Actions_To_Be_Wrapped_Before := No_List;
7234 SST.Actions_To_Be_Wrapped_After := No_List;
7235 SST.First_Use_Clause := Empty;
7236 SST.Is_Active_Stack_Base := False;
7237 SST.Previous_Visibility := False;
7240 if Debug_Flag_W then
7241 Write_Str ("--> new scope: ");
7242 Write_Name (Chars (Current_Scope));
7243 Write_Str (", Id=");
7244 Write_Int (Int (Current_Scope));
7245 Write_Str (", Depth=");
7246 Write_Int (Int (Scope_Stack.Last));
7250 -- Deal with copying flags from the previous scope to this one. This is
7251 -- not necessary if either scope is standard, or if the new scope is a
7254 if S /= Standard_Standard
7255 and then Scope (S) /= Standard_Standard
7256 and then not Is_Child_Unit (S)
7258 if Nkind (E) not in N_Entity then
7262 -- Copy categorization flags from Scope (S) to S, this is not done
7263 -- when Scope (S) is Standard_Standard since propagation is from
7264 -- library unit entity inwards. Copy other relevant attributes as
7265 -- well (Discard_Names in particular).
7267 -- We only propagate inwards for library level entities,
7268 -- inner level subprograms do not inherit the categorization.
7270 if Is_Library_Level_Entity (S) then
7271 Set_Is_Preelaborated (S, Is_Preelaborated (E));
7272 Set_Is_Shared_Passive (S, Is_Shared_Passive (E));
7273 Set_Discard_Names (S, Discard_Names (E));
7274 Set_Suppress_Value_Tracking_On_Call
7275 (S, Suppress_Value_Tracking_On_Call (E));
7276 Set_Categorization_From_Scope (E => S, Scop => E);
7280 if Is_Child_Unit (S)
7281 and then Present (E)
7282 and then Ekind_In (E, E_Package, E_Generic_Package)
7284 Nkind (Parent (Unit_Declaration_Node (E))) = N_Compilation_Unit
7287 Aux : constant Node_Id :=
7288 Aux_Decls_Node (Parent (Unit_Declaration_Node (E)));
7290 if Present (Default_Storage_Pool (Aux)) then
7291 Default_Pool := Default_Storage_Pool (Aux);
7297 ---------------------
7298 -- Premature_Usage --
7299 ---------------------
7301 procedure Premature_Usage (N : Node_Id) is
7302 Kind : constant Node_Kind := Nkind (Parent (Entity (N)));
7303 E : Entity_Id := Entity (N);
7306 -- Within an instance, the analysis of the actual for a formal object
7307 -- does not see the name of the object itself. This is significant only
7308 -- if the object is an aggregate, where its analysis does not do any
7309 -- name resolution on component associations. (see 4717-008). In such a
7310 -- case, look for the visible homonym on the chain.
7313 and then Present (Homonym (E))
7318 and then not In_Open_Scopes (Scope (E))
7325 Set_Etype (N, Etype (E));
7330 if Kind = N_Component_Declaration then
7332 ("component&! cannot be used before end of record declaration", N);
7334 elsif Kind = N_Parameter_Specification then
7336 ("formal parameter&! cannot be used before end of specification",
7339 elsif Kind = N_Discriminant_Specification then
7341 ("discriminant&! cannot be used before end of discriminant part",
7344 elsif Kind = N_Procedure_Specification
7345 or else Kind = N_Function_Specification
7348 ("subprogram&! cannot be used before end of its declaration",
7351 elsif Kind = N_Full_Type_Declaration then
7353 ("type& cannot be used before end of its declaration!", N);
7357 ("object& cannot be used before end of its declaration!", N);
7359 end Premature_Usage;
7361 ------------------------
7362 -- Present_System_Aux --
7363 ------------------------
7365 function Present_System_Aux (N : Node_Id := Empty) return Boolean is
7367 Aux_Name : Unit_Name_Type;
7368 Unum : Unit_Number_Type;
7373 function Find_System (C_Unit : Node_Id) return Entity_Id;
7374 -- Scan context clause of compilation unit to find with_clause
7381 function Find_System (C_Unit : Node_Id) return Entity_Id is
7382 With_Clause : Node_Id;
7385 With_Clause := First (Context_Items (C_Unit));
7386 while Present (With_Clause) loop
7387 if (Nkind (With_Clause) = N_With_Clause
7388 and then Chars (Name (With_Clause)) = Name_System)
7389 and then Comes_From_Source (With_Clause)
7400 -- Start of processing for Present_System_Aux
7403 -- The child unit may have been loaded and analyzed already
7405 if Present (System_Aux_Id) then
7408 -- If no previous pragma for System.Aux, nothing to load
7410 elsif No (System_Extend_Unit) then
7413 -- Use the unit name given in the pragma to retrieve the unit.
7414 -- Verify that System itself appears in the context clause of the
7415 -- current compilation. If System is not present, an error will
7416 -- have been reported already.
7419 With_Sys := Find_System (Cunit (Current_Sem_Unit));
7421 The_Unit := Unit (Cunit (Current_Sem_Unit));
7425 (Nkind (The_Unit) = N_Package_Body
7426 or else (Nkind (The_Unit) = N_Subprogram_Body
7428 not Acts_As_Spec (Cunit (Current_Sem_Unit))))
7430 With_Sys := Find_System (Library_Unit (Cunit (Current_Sem_Unit)));
7434 and then Present (N)
7436 -- If we are compiling a subunit, we need to examine its
7437 -- context as well (Current_Sem_Unit is the parent unit);
7439 The_Unit := Parent (N);
7440 while Nkind (The_Unit) /= N_Compilation_Unit loop
7441 The_Unit := Parent (The_Unit);
7444 if Nkind (Unit (The_Unit)) = N_Subunit then
7445 With_Sys := Find_System (The_Unit);
7449 if No (With_Sys) then
7453 Loc := Sloc (With_Sys);
7454 Get_Name_String (Chars (Expression (System_Extend_Unit)));
7455 Name_Buffer (8 .. Name_Len + 7) := Name_Buffer (1 .. Name_Len);
7456 Name_Buffer (1 .. 7) := "system.";
7457 Name_Buffer (Name_Len + 8) := '%';
7458 Name_Buffer (Name_Len + 9) := 's';
7459 Name_Len := Name_Len + 9;
7460 Aux_Name := Name_Find;
7464 (Load_Name => Aux_Name,
7467 Error_Node => With_Sys);
7469 if Unum /= No_Unit then
7470 Semantics (Cunit (Unum));
7472 Defining_Entity (Specification (Unit (Cunit (Unum))));
7475 Make_With_Clause (Loc,
7477 Make_Expanded_Name (Loc,
7478 Chars => Chars (System_Aux_Id),
7479 Prefix => New_Reference_To (Scope (System_Aux_Id), Loc),
7480 Selector_Name => New_Reference_To (System_Aux_Id, Loc)));
7482 Set_Entity (Name (Withn), System_Aux_Id);
7484 Set_Library_Unit (Withn, Cunit (Unum));
7485 Set_Corresponding_Spec (Withn, System_Aux_Id);
7486 Set_First_Name (Withn, True);
7487 Set_Implicit_With (Withn, True);
7489 Insert_After (With_Sys, Withn);
7490 Mark_Rewrite_Insertion (Withn);
7491 Set_Context_Installed (Withn);
7495 -- Here if unit load failed
7498 Error_Msg_Name_1 := Name_System;
7499 Error_Msg_Name_2 := Chars (Expression (System_Extend_Unit));
7501 ("extension package `%.%` does not exist",
7502 Opt.System_Extend_Unit);
7506 end Present_System_Aux;
7508 -------------------------
7509 -- Restore_Scope_Stack --
7510 -------------------------
7512 procedure Restore_Scope_Stack (Handle_Use : Boolean := True) is
7515 Comp_Unit : Node_Id;
7516 In_Child : Boolean := False;
7517 Full_Vis : Boolean := True;
7518 SS_Last : constant Int := Scope_Stack.Last;
7521 -- Restore visibility of previous scope stack, if any
7523 for J in reverse 0 .. Scope_Stack.Last loop
7524 exit when Scope_Stack.Table (J).Entity = Standard_Standard
7525 or else No (Scope_Stack.Table (J).Entity);
7527 S := Scope_Stack.Table (J).Entity;
7529 if not Is_Hidden_Open_Scope (S) then
7531 -- If the parent scope is hidden, its entities are hidden as
7532 -- well, unless the entity is the instantiation currently
7535 if not Is_Hidden_Open_Scope (Scope (S))
7536 or else not Analyzed (Parent (S))
7537 or else Scope (S) = Standard_Standard
7539 Set_Is_Immediately_Visible (S, True);
7542 E := First_Entity (S);
7543 while Present (E) loop
7544 if Is_Child_Unit (E) then
7545 if not From_With_Type (E) then
7546 Set_Is_Immediately_Visible (E,
7547 Is_Visible_Child_Unit (E) or else In_Open_Scopes (E));
7551 (Nkind (Parent (E)) = N_Defining_Program_Unit_Name
7553 Nkind (Parent (Parent (E))) = N_Package_Specification);
7554 Set_Is_Immediately_Visible (E,
7555 Limited_View_Installed (Parent (Parent (E))));
7558 Set_Is_Immediately_Visible (E, True);
7564 and then Is_Package_Or_Generic_Package (S)
7566 -- We are in the visible part of the package scope
7568 exit when E = First_Private_Entity (S);
7572 -- The visibility of child units (siblings of current compilation)
7573 -- must be restored in any case. Their declarations may appear
7574 -- after the private part of the parent.
7576 if not Full_Vis then
7577 while Present (E) loop
7578 if Is_Child_Unit (E) then
7579 Set_Is_Immediately_Visible (E,
7580 Is_Visible_Child_Unit (E) or else In_Open_Scopes (E));
7588 if Is_Child_Unit (S)
7589 and not In_Child -- check only for current unit
7593 -- Restore visibility of parents according to whether the child
7594 -- is private and whether we are in its visible part.
7596 Comp_Unit := Parent (Unit_Declaration_Node (S));
7598 if Nkind (Comp_Unit) = N_Compilation_Unit
7599 and then Private_Present (Comp_Unit)
7603 elsif Is_Package_Or_Generic_Package (S)
7604 and then (In_Private_Part (S) or else In_Package_Body (S))
7608 -- if S is the scope of some instance (which has already been
7609 -- seen on the stack) it does not affect the visibility of
7612 elsif Is_Hidden_Open_Scope (S) then
7615 elsif (Ekind (S) = E_Procedure
7616 or else Ekind (S) = E_Function)
7617 and then Has_Completion (S)
7628 if SS_Last >= Scope_Stack.First
7629 and then Scope_Stack.Table (SS_Last).Entity /= Standard_Standard
7632 Install_Use_Clauses (Scope_Stack.Table (SS_Last).First_Use_Clause);
7634 end Restore_Scope_Stack;
7636 ----------------------
7637 -- Save_Scope_Stack --
7638 ----------------------
7640 procedure Save_Scope_Stack (Handle_Use : Boolean := True) is
7643 SS_Last : constant Int := Scope_Stack.Last;
7646 if SS_Last >= Scope_Stack.First
7647 and then Scope_Stack.Table (SS_Last).Entity /= Standard_Standard
7650 End_Use_Clauses (Scope_Stack.Table (SS_Last).First_Use_Clause);
7653 -- If the call is from within a compilation unit, as when called from
7654 -- Rtsfind, make current entries in scope stack invisible while we
7655 -- analyze the new unit.
7657 for J in reverse 0 .. SS_Last loop
7658 exit when Scope_Stack.Table (J).Entity = Standard_Standard
7659 or else No (Scope_Stack.Table (J).Entity);
7661 S := Scope_Stack.Table (J).Entity;
7662 Set_Is_Immediately_Visible (S, False);
7664 E := First_Entity (S);
7665 while Present (E) loop
7666 Set_Is_Immediately_Visible (E, False);
7672 end Save_Scope_Stack;
7678 procedure Set_Use (L : List_Id) is
7680 Pack_Name : Node_Id;
7687 while Present (Decl) loop
7688 if Nkind (Decl) = N_Use_Package_Clause then
7689 Chain_Use_Clause (Decl);
7691 Pack_Name := First (Names (Decl));
7692 while Present (Pack_Name) loop
7693 Pack := Entity (Pack_Name);
7695 if Ekind (Pack) = E_Package
7696 and then Applicable_Use (Pack_Name)
7698 Use_One_Package (Pack, Decl);
7704 elsif Nkind (Decl) = N_Use_Type_Clause then
7705 Chain_Use_Clause (Decl);
7707 Id := First (Subtype_Marks (Decl));
7708 while Present (Id) loop
7709 if Entity (Id) /= Any_Type then
7722 ---------------------
7723 -- Use_One_Package --
7724 ---------------------
7726 procedure Use_One_Package (P : Entity_Id; N : Node_Id) is
7729 Current_Instance : Entity_Id := Empty;
7731 Private_With_OK : Boolean := False;
7734 if Ekind (P) /= E_Package then
7739 Set_Current_Use_Clause (P, N);
7741 -- Ada 2005 (AI-50217): Check restriction
7743 if From_With_Type (P) then
7744 Error_Msg_N ("limited withed package cannot appear in use clause", N);
7747 -- Find enclosing instance, if any
7750 Current_Instance := Current_Scope;
7751 while not Is_Generic_Instance (Current_Instance) loop
7752 Current_Instance := Scope (Current_Instance);
7755 if No (Hidden_By_Use_Clause (N)) then
7756 Set_Hidden_By_Use_Clause (N, New_Elmt_List);
7760 -- If unit is a package renaming, indicate that the renamed
7761 -- package is also in use (the flags on both entities must
7762 -- remain consistent, and a subsequent use of either of them
7763 -- should be recognized as redundant).
7765 if Present (Renamed_Object (P)) then
7766 Set_In_Use (Renamed_Object (P));
7767 Set_Current_Use_Clause (Renamed_Object (P), N);
7768 Real_P := Renamed_Object (P);
7773 -- Ada 2005 (AI-262): Check the use_clause of a private withed package
7774 -- found in the private part of a package specification
7776 if In_Private_Part (Current_Scope)
7777 and then Has_Private_With (P)
7778 and then Is_Child_Unit (Current_Scope)
7779 and then Is_Child_Unit (P)
7780 and then Is_Ancestor_Package (Scope (Current_Scope), P)
7782 Private_With_OK := True;
7785 -- Loop through entities in one package making them potentially
7788 Id := First_Entity (P);
7790 and then (Id /= First_Private_Entity (P)
7791 or else Private_With_OK) -- Ada 2005 (AI-262)
7793 Prev := Current_Entity (Id);
7794 while Present (Prev) loop
7795 if Is_Immediately_Visible (Prev)
7796 and then (not Is_Overloadable (Prev)
7797 or else not Is_Overloadable (Id)
7798 or else (Type_Conformant (Id, Prev)))
7800 if No (Current_Instance) then
7802 -- Potentially use-visible entity remains hidden
7804 goto Next_Usable_Entity;
7806 -- A use clause within an instance hides outer global entities,
7807 -- which are not used to resolve local entities in the
7808 -- instance. Note that the predefined entities in Standard
7809 -- could not have been hidden in the generic by a use clause,
7810 -- and therefore remain visible. Other compilation units whose
7811 -- entities appear in Standard must be hidden in an instance.
7813 -- To determine whether an entity is external to the instance
7814 -- we compare the scope depth of its scope with that of the
7815 -- current instance. However, a generic actual of a subprogram
7816 -- instance is declared in the wrapper package but will not be
7817 -- hidden by a use-visible entity. similarly, an entity that is
7818 -- declared in an enclosing instance will not be hidden by an
7819 -- an entity declared in a generic actual, which can only have
7820 -- been use-visible in the generic and will not have hidden the
7821 -- entity in the generic parent.
7823 -- If Id is called Standard, the predefined package with the
7824 -- same name is in the homonym chain. It has to be ignored
7825 -- because it has no defined scope (being the only entity in
7826 -- the system with this mandated behavior).
7828 elsif not Is_Hidden (Id)
7829 and then Present (Scope (Prev))
7830 and then not Is_Wrapper_Package (Scope (Prev))
7831 and then Scope_Depth (Scope (Prev)) <
7832 Scope_Depth (Current_Instance)
7833 and then (Scope (Prev) /= Standard_Standard
7834 or else Sloc (Prev) > Standard_Location)
7836 if In_Open_Scopes (Scope (Prev))
7837 and then Is_Generic_Instance (Scope (Prev))
7838 and then Present (Associated_Formal_Package (P))
7843 Set_Is_Potentially_Use_Visible (Id);
7844 Set_Is_Immediately_Visible (Prev, False);
7845 Append_Elmt (Prev, Hidden_By_Use_Clause (N));
7849 -- A user-defined operator is not use-visible if the predefined
7850 -- operator for the type is immediately visible, which is the case
7851 -- if the type of the operand is in an open scope. This does not
7852 -- apply to user-defined operators that have operands of different
7853 -- types, because the predefined mixed mode operations (multiply
7854 -- and divide) apply to universal types and do not hide anything.
7856 elsif Ekind (Prev) = E_Operator
7857 and then Operator_Matches_Spec (Prev, Id)
7858 and then In_Open_Scopes
7859 (Scope (Base_Type (Etype (First_Formal (Id)))))
7860 and then (No (Next_Formal (First_Formal (Id)))
7861 or else Etype (First_Formal (Id))
7862 = Etype (Next_Formal (First_Formal (Id)))
7863 or else Chars (Prev) = Name_Op_Expon)
7865 goto Next_Usable_Entity;
7867 -- In an instance, two homonyms may become use_visible through the
7868 -- actuals of distinct formal packages. In the generic, only the
7869 -- current one would have been visible, so make the other one
7872 elsif Present (Current_Instance)
7873 and then Is_Potentially_Use_Visible (Prev)
7874 and then not Is_Overloadable (Prev)
7875 and then Scope (Id) /= Scope (Prev)
7876 and then Used_As_Generic_Actual (Scope (Prev))
7877 and then Used_As_Generic_Actual (Scope (Id))
7878 and then not In_Same_List (Current_Use_Clause (Scope (Prev)),
7879 Current_Use_Clause (Scope (Id)))
7881 Set_Is_Potentially_Use_Visible (Prev, False);
7882 Append_Elmt (Prev, Hidden_By_Use_Clause (N));
7885 Prev := Homonym (Prev);
7888 -- On exit, we know entity is not hidden, unless it is private
7890 if not Is_Hidden (Id)
7891 and then ((not Is_Child_Unit (Id))
7892 or else Is_Visible_Child_Unit (Id))
7894 Set_Is_Potentially_Use_Visible (Id);
7896 if Is_Private_Type (Id)
7897 and then Present (Full_View (Id))
7899 Set_Is_Potentially_Use_Visible (Full_View (Id));
7903 <<Next_Usable_Entity>>
7907 -- Child units are also made use-visible by a use clause, but they may
7908 -- appear after all visible declarations in the parent entity list.
7910 while Present (Id) loop
7911 if Is_Child_Unit (Id)
7912 and then Is_Visible_Child_Unit (Id)
7914 Set_Is_Potentially_Use_Visible (Id);
7920 if Chars (Real_P) = Name_System
7921 and then Scope (Real_P) = Standard_Standard
7922 and then Present_System_Aux (N)
7924 Use_One_Package (System_Aux_Id, N);
7927 end Use_One_Package;
7933 procedure Use_One_Type (Id : Node_Id; Installed : Boolean := False) is
7935 Is_Known_Used : Boolean;
7939 function Spec_Reloaded_For_Body return Boolean;
7940 -- Determine whether the compilation unit is a package body and the use
7941 -- type clause is in the spec of the same package. Even though the spec
7942 -- was analyzed first, its context is reloaded when analysing the body.
7944 procedure Use_Class_Wide_Operations (Typ : Entity_Id);
7945 -- AI05-150: if the use_type_clause carries the "all" qualifier,
7946 -- class-wide operations of ancestor types are use-visible if the
7947 -- ancestor type is visible.
7949 ----------------------------
7950 -- Spec_Reloaded_For_Body --
7951 ----------------------------
7953 function Spec_Reloaded_For_Body return Boolean is
7955 if Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Body then
7957 Spec : constant Node_Id :=
7958 Parent (List_Containing (Parent (Id)));
7961 Nkind (Spec) = N_Package_Specification
7962 and then Corresponding_Body (Parent (Spec)) =
7963 Cunit_Entity (Current_Sem_Unit);
7968 end Spec_Reloaded_For_Body;
7970 -------------------------------
7971 -- Use_Class_Wide_Operations --
7972 -------------------------------
7974 procedure Use_Class_Wide_Operations (Typ : Entity_Id) is
7978 function Is_Class_Wide_Operation_Of
7980 T : Entity_Id) return Boolean;
7981 -- Determine whether a subprogram has a class-wide parameter or
7982 -- result that is T'Class.
7984 ---------------------------------
7985 -- Is_Class_Wide_Operation_Of --
7986 ---------------------------------
7988 function Is_Class_Wide_Operation_Of
7990 T : Entity_Id) return Boolean
7995 Formal := First_Formal (Op);
7996 while Present (Formal) loop
7997 if Etype (Formal) = Class_Wide_Type (T) then
8000 Next_Formal (Formal);
8003 if Etype (Op) = Class_Wide_Type (T) then
8008 end Is_Class_Wide_Operation_Of;
8010 -- Start of processing for Use_Class_Wide_Operations
8013 Scop := Scope (Typ);
8014 if not Is_Hidden (Scop) then
8015 Ent := First_Entity (Scop);
8016 while Present (Ent) loop
8017 if Is_Overloadable (Ent)
8018 and then Is_Class_Wide_Operation_Of (Ent, Typ)
8019 and then not Is_Potentially_Use_Visible (Ent)
8021 Set_Is_Potentially_Use_Visible (Ent);
8022 Append_Elmt (Ent, Used_Operations (Parent (Id)));
8029 if Is_Derived_Type (Typ) then
8030 Use_Class_Wide_Operations (Etype (Base_Type (Typ)));
8032 end Use_Class_Wide_Operations;
8034 -- Start of processing for Use_One_Type
8037 -- It is the type determined by the subtype mark (8.4(8)) whose
8038 -- operations become potentially use-visible.
8040 T := Base_Type (Entity (Id));
8042 -- Either the type itself is used, the package where it is declared
8043 -- is in use or the entity is declared in the current package, thus
8048 or else In_Use (Scope (T))
8049 or else Scope (T) = Current_Scope;
8051 Set_Redundant_Use (Id,
8052 Is_Known_Used or else Is_Potentially_Use_Visible (T));
8054 if Ekind (T) = E_Incomplete_Type then
8055 Error_Msg_N ("premature usage of incomplete type", Id);
8057 elsif In_Open_Scopes (Scope (T)) then
8060 -- A limited view cannot appear in a use_type clause. However, an access
8061 -- type whose designated type is limited has the flag but is not itself
8062 -- a limited view unless we only have a limited view of its enclosing
8065 elsif From_With_Type (T)
8066 and then From_With_Type (Scope (T))
8069 ("incomplete type from limited view "
8070 & "cannot appear in use clause", Id);
8072 -- If the subtype mark designates a subtype in a different package,
8073 -- we have to check that the parent type is visible, otherwise the
8074 -- use type clause is a noop. Not clear how to do that???
8076 elsif not Redundant_Use (Id) then
8079 -- If T is tagged, primitive operators on class-wide operands
8080 -- are also available.
8082 if Is_Tagged_Type (T) then
8083 Set_In_Use (Class_Wide_Type (T));
8086 Set_Current_Use_Clause (T, Parent (Id));
8088 -- Iterate over primitive operations of the type. If an operation is
8089 -- already use_visible, it is the result of a previous use_clause,
8090 -- and already appears on the corresponding entity chain. If the
8091 -- clause is being reinstalled, operations are already use-visible.
8097 Op_List := Collect_Primitive_Operations (T);
8098 Elmt := First_Elmt (Op_List);
8099 while Present (Elmt) loop
8100 if (Nkind (Node (Elmt)) = N_Defining_Operator_Symbol
8101 or else Chars (Node (Elmt)) in Any_Operator_Name)
8102 and then not Is_Hidden (Node (Elmt))
8103 and then not Is_Potentially_Use_Visible (Node (Elmt))
8105 Set_Is_Potentially_Use_Visible (Node (Elmt));
8106 Append_Elmt (Node (Elmt), Used_Operations (Parent (Id)));
8108 elsif Ada_Version >= Ada_2012
8109 and then All_Present (Parent (Id))
8110 and then not Is_Hidden (Node (Elmt))
8111 and then not Is_Potentially_Use_Visible (Node (Elmt))
8113 Set_Is_Potentially_Use_Visible (Node (Elmt));
8114 Append_Elmt (Node (Elmt), Used_Operations (Parent (Id)));
8121 if Ada_Version >= Ada_2012
8122 and then All_Present (Parent (Id))
8123 and then Is_Tagged_Type (T)
8125 Use_Class_Wide_Operations (T);
8129 -- If warning on redundant constructs, check for unnecessary WITH
8131 if Warn_On_Redundant_Constructs
8132 and then Is_Known_Used
8134 -- with P; with P; use P;
8135 -- package P is package X is package body X is
8136 -- type T ... use P.T;
8138 -- The compilation unit is the body of X. GNAT first compiles the
8139 -- spec of X, then proceeds to the body. At that point P is marked
8140 -- as use visible. The analysis then reinstalls the spec along with
8141 -- its context. The use clause P.T is now recognized as redundant,
8142 -- but in the wrong context. Do not emit a warning in such cases.
8143 -- Do not emit a warning either if we are in an instance, there is
8144 -- no redundancy between an outer use_clause and one that appears
8145 -- within the generic.
8147 and then not Spec_Reloaded_For_Body
8148 and then not In_Instance
8150 -- The type already has a use clause
8154 -- Case where we know the current use clause for the type
8156 if Present (Current_Use_Clause (T)) then
8157 Use_Clause_Known : declare
8158 Clause1 : constant Node_Id := Parent (Id);
8159 Clause2 : constant Node_Id := Current_Use_Clause (T);
8166 function Entity_Of_Unit (U : Node_Id) return Entity_Id;
8167 -- Return the appropriate entity for determining which unit
8168 -- has a deeper scope: the defining entity for U, unless U
8169 -- is a package instance, in which case we retrieve the
8170 -- entity of the instance spec.
8172 --------------------
8173 -- Entity_Of_Unit --
8174 --------------------
8176 function Entity_Of_Unit (U : Node_Id) return Entity_Id is
8178 if Nkind (U) = N_Package_Instantiation
8179 and then Analyzed (U)
8181 return Defining_Entity (Instance_Spec (U));
8183 return Defining_Entity (U);
8187 -- Start of processing for Use_Clause_Known
8190 -- If both current use type clause and the use type clause
8191 -- for the type are at the compilation unit level, one of
8192 -- the units must be an ancestor of the other, and the
8193 -- warning belongs on the descendant.
8195 if Nkind (Parent (Clause1)) = N_Compilation_Unit
8197 Nkind (Parent (Clause2)) = N_Compilation_Unit
8200 -- If the unit is a subprogram body that acts as spec,
8201 -- the context clause is shared with the constructed
8202 -- subprogram spec. Clearly there is no redundancy.
8204 if Clause1 = Clause2 then
8208 Unit1 := Unit (Parent (Clause1));
8209 Unit2 := Unit (Parent (Clause2));
8211 -- If both clauses are on same unit, or one is the body
8212 -- of the other, or one of them is in a subunit, report
8213 -- redundancy on the later one.
8215 if Unit1 = Unit2 then
8216 Error_Msg_Sloc := Sloc (Current_Use_Clause (T));
8217 Error_Msg_NE -- CODEFIX
8218 ("& is already use-visible through previous "
8219 & "use_type_clause #?", Clause1, T);
8222 elsif Nkind (Unit1) = N_Subunit then
8223 Error_Msg_Sloc := Sloc (Current_Use_Clause (T));
8224 Error_Msg_NE -- CODEFIX
8225 ("& is already use-visible through previous "
8226 & "use_type_clause #?", Clause1, T);
8229 elsif Nkind_In (Unit2, N_Package_Body, N_Subprogram_Body)
8230 and then Nkind (Unit1) /= Nkind (Unit2)
8231 and then Nkind (Unit1) /= N_Subunit
8233 Error_Msg_Sloc := Sloc (Clause1);
8234 Error_Msg_NE -- CODEFIX
8235 ("& is already use-visible through previous "
8236 & "use_type_clause #?", Current_Use_Clause (T), T);
8240 -- There is a redundant use type clause in a child unit.
8241 -- Determine which of the units is more deeply nested.
8242 -- If a unit is a package instance, retrieve the entity
8243 -- and its scope from the instance spec.
8245 Ent1 := Entity_Of_Unit (Unit1);
8246 Ent2 := Entity_Of_Unit (Unit2);
8248 if Scope (Ent2) = Standard_Standard then
8249 Error_Msg_Sloc := Sloc (Current_Use_Clause (T));
8252 elsif Scope (Ent1) = Standard_Standard then
8253 Error_Msg_Sloc := Sloc (Id);
8256 -- If both units are child units, we determine which one
8257 -- is the descendant by the scope distance to the
8258 -- ultimate parent unit.
8268 and then Present (S2)
8269 and then S1 /= Standard_Standard
8270 and then S2 /= Standard_Standard
8276 if S1 = Standard_Standard then
8277 Error_Msg_Sloc := Sloc (Id);
8280 Error_Msg_Sloc := Sloc (Current_Use_Clause (T));
8286 Error_Msg_NE -- CODEFIX
8287 ("& is already use-visible through previous "
8288 & "use_type_clause #?", Err_No, Id);
8290 -- Case where current use type clause and the use type
8291 -- clause for the type are not both at the compilation unit
8292 -- level. In this case we don't have location information.
8295 Error_Msg_NE -- CODEFIX
8296 ("& is already use-visible through previous "
8297 & "use type clause?", Id, T);
8299 end Use_Clause_Known;
8301 -- Here if Current_Use_Clause is not set for T, another case
8302 -- where we do not have the location information available.
8305 Error_Msg_NE -- CODEFIX
8306 ("& is already use-visible through previous "
8307 & "use type clause?", Id, T);
8310 -- The package where T is declared is already used
8312 elsif In_Use (Scope (T)) then
8313 Error_Msg_Sloc := Sloc (Current_Use_Clause (Scope (T)));
8314 Error_Msg_NE -- CODEFIX
8315 ("& is already use-visible through package use clause #?",
8318 -- The current scope is the package where T is declared
8321 Error_Msg_Node_2 := Scope (T);
8322 Error_Msg_NE -- CODEFIX
8323 ("& is already use-visible inside package &?", Id, T);
8332 procedure Write_Info is
8333 Id : Entity_Id := First_Entity (Current_Scope);
8336 -- No point in dumping standard entities
8338 if Current_Scope = Standard_Standard then
8342 Write_Str ("========================================================");
8344 Write_Str (" Defined Entities in ");
8345 Write_Name (Chars (Current_Scope));
8347 Write_Str ("========================================================");
8351 Write_Str ("-- none --");
8355 while Present (Id) loop
8356 Write_Entity_Info (Id, " ");
8361 if Scope (Current_Scope) = Standard_Standard then
8363 -- Print information on the current unit itself
8365 Write_Entity_Info (Current_Scope, " ");
8378 for J in reverse 1 .. Scope_Stack.Last loop
8379 S := Scope_Stack.Table (J).Entity;
8380 Write_Int (Int (S));
8381 Write_Str (" === ");
8382 Write_Name (Chars (S));
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