1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2016, 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_Disp; use Exp_Disp;
32 with Exp_Tss; use Exp_Tss;
33 with Exp_Util; use Exp_Util;
34 with Fname; use Fname;
35 with Freeze; use Freeze;
36 with Ghost; use Ghost;
37 with Impunit; use Impunit;
39 with Lib.Load; use Lib.Load;
40 with Lib.Xref; use Lib.Xref;
41 with Namet; use Namet;
42 with Namet.Sp; use Namet.Sp;
43 with Nlists; use Nlists;
44 with Nmake; use Nmake;
46 with Output; use Output;
47 with Restrict; use Restrict;
48 with Rident; use Rident;
49 with Rtsfind; use Rtsfind;
51 with Sem_Aux; use Sem_Aux;
52 with Sem_Cat; use Sem_Cat;
53 with Sem_Ch3; use Sem_Ch3;
54 with Sem_Ch4; use Sem_Ch4;
55 with Sem_Ch6; use Sem_Ch6;
56 with Sem_Ch12; use Sem_Ch12;
57 with Sem_Ch13; use Sem_Ch13;
58 with Sem_Dim; use Sem_Dim;
59 with Sem_Disp; use Sem_Disp;
60 with Sem_Dist; use Sem_Dist;
61 with Sem_Eval; use Sem_Eval;
62 with Sem_Res; use Sem_Res;
63 with Sem_Util; use Sem_Util;
64 with Sem_Type; use Sem_Type;
65 with Stand; use Stand;
66 with Sinfo; use Sinfo;
67 with Sinfo.CN; use Sinfo.CN;
68 with Snames; use Snames;
69 with Style; use Style;
71 with Tbuild; use Tbuild;
72 with Uintp; use Uintp;
74 package body Sem_Ch8 is
76 ------------------------------------
77 -- Visibility and Name Resolution --
78 ------------------------------------
80 -- This package handles name resolution and the collection of possible
81 -- interpretations for overloaded names, prior to overload resolution.
83 -- Name resolution is the process that establishes a mapping between source
84 -- identifiers and the entities they denote at each point in the program.
85 -- Each entity is represented by a defining occurrence. Each identifier
86 -- that denotes an entity points to the corresponding defining occurrence.
87 -- This is the entity of the applied occurrence. Each occurrence holds
88 -- an index into the names table, where source identifiers are stored.
90 -- Each entry in the names table for an identifier or designator uses the
91 -- Info pointer to hold a link to the currently visible entity that has
92 -- this name (see subprograms Get_Name_Entity_Id and Set_Name_Entity_Id
93 -- in package Sem_Util). The visibility is initialized at the beginning of
94 -- semantic processing to make entities in package Standard immediately
95 -- visible. The visibility table is used in a more subtle way when
96 -- compiling subunits (see below).
98 -- Entities that have the same name (i.e. homonyms) are chained. In the
99 -- case of overloaded entities, this chain holds all the possible meanings
100 -- of a given identifier. The process of overload resolution uses type
101 -- information to select from this chain the unique meaning of a given
104 -- Entities are also chained in their scope, through the Next_Entity link.
105 -- As a consequence, the name space is organized as a sparse matrix, where
106 -- each row corresponds to a scope, and each column to a source identifier.
107 -- Open scopes, that is to say scopes currently being compiled, have their
108 -- corresponding rows of entities in order, innermost scope first.
110 -- The scopes of packages that are mentioned in context clauses appear in
111 -- no particular order, interspersed among open scopes. This is because
112 -- in the course of analyzing the context of a compilation, a package
113 -- declaration is first an open scope, and subsequently an element of the
114 -- context. If subunits or child units are present, a parent unit may
115 -- appear under various guises at various times in the compilation.
117 -- When the compilation of the innermost scope is complete, the entities
118 -- defined therein are no longer visible. If the scope is not a package
119 -- declaration, these entities are never visible subsequently, and can be
120 -- removed from visibility chains. If the scope is a package declaration,
121 -- its visible declarations may still be accessible. Therefore the entities
122 -- defined in such a scope are left on the visibility chains, and only
123 -- their visibility (immediately visibility or potential use-visibility)
126 -- The ordering of homonyms on their chain does not necessarily follow
127 -- the order of their corresponding scopes on the scope stack. For
128 -- example, if package P and the enclosing scope both contain entities
129 -- named E, then when compiling the package body the chain for E will
130 -- hold the global entity first, and the local one (corresponding to
131 -- the current inner scope) next. As a result, name resolution routines
132 -- do not assume any relative ordering of the homonym chains, either
133 -- for scope nesting or to order of appearance of context clauses.
135 -- When compiling a child unit, entities in the parent scope are always
136 -- immediately visible. When compiling the body of a child unit, private
137 -- entities in the parent must also be made immediately visible. There
138 -- are separate routines to make the visible and private declarations
139 -- visible at various times (see package Sem_Ch7).
141 -- +--------+ +-----+
142 -- | In use |-------->| EU1 |-------------------------->
143 -- +--------+ +-----+
145 -- +--------+ +-----+ +-----+
146 -- | Stand. |---------------->| ES1 |--------------->| ES2 |--->
147 -- +--------+ +-----+ +-----+
149 -- +---------+ | +-----+
150 -- | with'ed |------------------------------>| EW2 |--->
151 -- +---------+ | +-----+
153 -- +--------+ +-----+ +-----+
154 -- | Scope2 |---------------->| E12 |--------------->| E22 |--->
155 -- +--------+ +-----+ +-----+
157 -- +--------+ +-----+ +-----+
158 -- | Scope1 |---------------->| E11 |--------------->| E12 |--->
159 -- +--------+ +-----+ +-----+
163 -- | | with'ed |----------------------------------------->
167 -- (innermost first) | |
168 -- +----------------------------+
169 -- Names table => | Id1 | | | | Id2 |
170 -- +----------------------------+
172 -- Name resolution must deal with several syntactic forms: simple names,
173 -- qualified names, indexed names, and various forms of calls.
175 -- Each identifier points to an entry in the names table. The resolution
176 -- of a simple name consists in traversing the homonym chain, starting
177 -- from the names table. If an entry is immediately visible, it is the one
178 -- designated by the identifier. If only potentially use-visible entities
179 -- are on the chain, we must verify that they do not hide each other. If
180 -- the entity we find is overloadable, we collect all other overloadable
181 -- entities on the chain as long as they are not hidden.
183 -- To resolve expanded names, we must find the entity at the intersection
184 -- of the entity chain for the scope (the prefix) and the homonym chain
185 -- for the selector. In general, homonym chains will be much shorter than
186 -- entity chains, so it is preferable to start from the names table as
187 -- well. If the entity found is overloadable, we must collect all other
188 -- interpretations that are defined in the scope denoted by the prefix.
190 -- For records, protected types, and tasks, their local entities are
191 -- removed from visibility chains on exit from the corresponding scope.
192 -- From the outside, these entities are always accessed by selected
193 -- notation, and the entity chain for the record type, protected type,
194 -- etc. is traversed sequentially in order to find the designated entity.
196 -- The discriminants of a type and the operations of a protected type or
197 -- task are unchained on exit from the first view of the type, (such as
198 -- a private or incomplete type declaration, or a protected type speci-
199 -- fication) and re-chained when compiling the second view.
201 -- In the case of operators, we do not make operators on derived types
202 -- explicit. As a result, the notation P."+" may denote either a user-
203 -- defined function with name "+", or else an implicit declaration of the
204 -- operator "+" in package P. The resolution of expanded names always
205 -- tries to resolve an operator name as such an implicitly defined entity,
206 -- in addition to looking for explicit declarations.
208 -- All forms of names that denote entities (simple names, expanded names,
209 -- character literals in some cases) have a Entity attribute, which
210 -- identifies the entity denoted by the name.
212 ---------------------
213 -- The Scope Stack --
214 ---------------------
216 -- The Scope stack keeps track of the scopes currently been compiled.
217 -- Every entity that contains declarations (including records) is placed
218 -- on the scope stack while it is being processed, and removed at the end.
219 -- Whenever a non-package scope is exited, the entities defined therein
220 -- are removed from the visibility table, so that entities in outer scopes
221 -- become visible (see previous description). On entry to Sem, the scope
222 -- stack only contains the package Standard. As usual, subunits complicate
223 -- this picture ever so slightly.
225 -- The Rtsfind mechanism can force a call to Semantics while another
226 -- compilation is in progress. The unit retrieved by Rtsfind must be
227 -- compiled in its own context, and has no access to the visibility of
228 -- the unit currently being compiled. The procedures Save_Scope_Stack and
229 -- Restore_Scope_Stack make entities in current open scopes invisible
230 -- before compiling the retrieved unit, and restore the compilation
231 -- environment afterwards.
233 ------------------------
234 -- Compiling subunits --
235 ------------------------
237 -- Subunits must be compiled in the environment of the corresponding stub,
238 -- that is to say with the same visibility into the parent (and its
239 -- context) that is available at the point of the stub declaration, but
240 -- with the additional visibility provided by the context clause of the
241 -- subunit itself. As a result, compilation of a subunit forces compilation
242 -- of the parent (see description in lib-). At the point of the stub
243 -- declaration, Analyze is called recursively to compile the proper body of
244 -- the subunit, but without reinitializing the names table, nor the scope
245 -- stack (i.e. standard is not pushed on the stack). In this fashion the
246 -- context of the subunit is added to the context of the parent, and the
247 -- subunit is compiled in the correct environment. Note that in the course
248 -- of processing the context of a subunit, Standard will appear twice on
249 -- the scope stack: once for the parent of the subunit, and once for the
250 -- unit in the context clause being compiled. However, the two sets of
251 -- entities are not linked by homonym chains, so that the compilation of
252 -- any context unit happens in a fresh visibility environment.
254 -------------------------------
255 -- Processing of USE Clauses --
256 -------------------------------
258 -- Every defining occurrence has a flag indicating if it is potentially use
259 -- visible. Resolution of simple names examines this flag. The processing
260 -- of use clauses consists in setting this flag on all visible entities
261 -- defined in the corresponding package. On exit from the scope of the use
262 -- clause, the corresponding flag must be reset. However, a package may
263 -- appear in several nested use clauses (pathological but legal, alas)
264 -- which forces us to use a slightly more involved scheme:
266 -- a) The defining occurrence for a package holds a flag -In_Use- to
267 -- indicate that it is currently in the scope of a use clause. If a
268 -- redundant use clause is encountered, then the corresponding occurrence
269 -- of the package name is flagged -Redundant_Use-.
271 -- b) On exit from a scope, the use clauses in its declarative part are
272 -- scanned. The visibility flag is reset in all entities declared in
273 -- package named in a use clause, as long as the package is not flagged
274 -- as being in a redundant use clause (in which case the outer use
275 -- clause is still in effect, and the direct visibility of its entities
276 -- must be retained).
278 -- Note that entities are not removed from their homonym chains on exit
279 -- from the package specification. A subsequent use clause does not need
280 -- to rechain the visible entities, but only to establish their direct
283 -----------------------------------
284 -- Handling private declarations --
285 -----------------------------------
287 -- The principle that each entity has a single defining occurrence clashes
288 -- with the presence of two separate definitions for private types: the
289 -- first is the private type declaration, and second is the full type
290 -- declaration. It is important that all references to the type point to
291 -- the same defining occurrence, namely the first one. To enforce the two
292 -- separate views of the entity, the corresponding information is swapped
293 -- between the two declarations. Outside of the package, the defining
294 -- occurrence only contains the private declaration information, while in
295 -- the private part and the body of the package the defining occurrence
296 -- contains the full declaration. To simplify the swap, the defining
297 -- occurrence that currently holds the private declaration points to the
298 -- full declaration. During semantic processing the defining occurrence
299 -- also points to a list of private dependents, that is to say access types
300 -- or composite types whose designated types or component types are
301 -- subtypes or derived types of the private type in question. After the
302 -- full declaration has been seen, the private dependents are updated to
303 -- indicate that they have full definitions.
305 ------------------------------------
306 -- Handling of Undefined Messages --
307 ------------------------------------
309 -- In normal mode, only the first use of an undefined identifier generates
310 -- a message. The table Urefs is used to record error messages that have
311 -- been issued so that second and subsequent ones do not generate further
312 -- messages. However, the second reference causes text to be added to the
313 -- original undefined message noting "(more references follow)". The
314 -- full error list option (-gnatf) forces messages to be generated for
315 -- every reference and disconnects the use of this table.
317 type Uref_Entry is record
319 -- Node for identifier for which original message was posted. The
320 -- Chars field of this identifier is used to detect later references
321 -- to the same identifier.
324 -- Records error message Id of original undefined message. Reset to
325 -- No_Error_Msg after the second occurrence, where it is used to add
326 -- text to the original message as described above.
329 -- Set if the message is not visible rather than undefined
332 -- Records location of error message. Used to make sure that we do
333 -- not consider a, b : undefined as two separate instances, which
334 -- would otherwise happen, since the parser converts this sequence
335 -- to a : undefined; b : undefined.
339 package Urefs is new Table.Table (
340 Table_Component_Type => Uref_Entry,
341 Table_Index_Type => Nat,
342 Table_Low_Bound => 1,
344 Table_Increment => 100,
345 Table_Name => "Urefs");
347 Candidate_Renaming : Entity_Id;
348 -- Holds a candidate interpretation that appears in a subprogram renaming
349 -- declaration and does not match the given specification, but matches at
350 -- least on the first formal. Allows better error message when given
351 -- specification omits defaulted parameters, a common error.
353 -----------------------
354 -- Local Subprograms --
355 -----------------------
357 procedure Analyze_Generic_Renaming
360 -- Common processing for all three kinds of generic renaming declarations.
361 -- Enter new name and indicate that it renames the generic unit.
363 procedure Analyze_Renamed_Character
367 -- Renamed entity is given by a character literal, which must belong
368 -- to the return type of the new entity. Is_Body indicates whether the
369 -- declaration is a renaming_as_body. If the original declaration has
370 -- already been frozen (because of an intervening body, e.g.) the body of
371 -- the function must be built now. The same applies to the following
372 -- various renaming procedures.
374 procedure Analyze_Renamed_Dereference
378 -- Renamed entity is given by an explicit dereference. Prefix must be a
379 -- conformant access_to_subprogram type.
381 procedure Analyze_Renamed_Entry
385 -- If the renamed entity in a subprogram renaming is an entry or protected
386 -- subprogram, build a body for the new entity whose only statement is a
387 -- call to the renamed entity.
389 procedure Analyze_Renamed_Family_Member
393 -- Used when the renamed entity is an indexed component. The prefix must
394 -- denote an entry family.
396 procedure Analyze_Renamed_Primitive_Operation
400 -- If the renamed entity in a subprogram renaming is a primitive operation
401 -- or a class-wide operation in prefix form, save the target object,
402 -- which must be added to the list of actuals in any subsequent call.
403 -- The renaming operation is intrinsic because the compiler must in
404 -- fact generate a wrapper for it (6.3.1 (10 1/2)).
406 function Applicable_Use (Pack_Name : Node_Id) return Boolean;
407 -- Common code to Use_One_Package and Set_Use, to determine whether use
408 -- clause must be processed. Pack_Name is an entity name that references
409 -- the package in question.
411 procedure Attribute_Renaming (N : Node_Id);
412 -- Analyze renaming of attribute as subprogram. The renaming declaration N
413 -- is rewritten as a subprogram body that returns the attribute reference
414 -- applied to the formals of the function.
416 procedure Set_Entity_Or_Discriminal (N : Node_Id; E : Entity_Id);
417 -- Set Entity, with style check if need be. For a discriminant reference,
418 -- replace by the corresponding discriminal, i.e. the parameter of the
419 -- initialization procedure that corresponds to the discriminant.
421 procedure Check_Frozen_Renaming (N : Node_Id; Subp : Entity_Id);
422 -- A renaming_as_body may occur after the entity of the original decla-
423 -- ration has been frozen. In that case, the body of the new entity must
424 -- be built now, because the usual mechanism of building the renamed
425 -- body at the point of freezing will not work. Subp is the subprogram
426 -- for which N provides the Renaming_As_Body.
428 procedure Check_In_Previous_With_Clause
431 -- N is a use_package clause and Nam the package name, or N is a use_type
432 -- clause and Nam is the prefix of the type name. In either case, verify
433 -- that the package is visible at that point in the context: either it
434 -- appears in a previous with_clause, or because it is a fully qualified
435 -- name and the root ancestor appears in a previous with_clause.
437 procedure Check_Library_Unit_Renaming (N : Node_Id; Old_E : Entity_Id);
438 -- Verify that the entity in a renaming declaration that is a library unit
439 -- is itself a library unit and not a nested unit or subunit. Also check
440 -- that if the renaming is a child unit of a generic parent, then the
441 -- renamed unit must also be a child unit of that parent. Finally, verify
442 -- that a renamed generic unit is not an implicit child declared within
443 -- an instance of the parent.
445 procedure Chain_Use_Clause (N : Node_Id);
446 -- Chain use clause onto list of uses clauses headed by First_Use_Clause in
447 -- the proper scope table entry. This is usually the current scope, but it
448 -- will be an inner scope when installing the use clauses of the private
449 -- declarations of a parent unit prior to compiling the private part of a
450 -- child unit. This chain is traversed when installing/removing use clauses
451 -- when compiling a subunit or instantiating a generic body on the fly,
452 -- when it is necessary to save and restore full environments.
454 function Enclosing_Instance return Entity_Id;
455 -- In an instance nested within another one, several semantic checks are
456 -- unnecessary because the legality of the nested instance has been checked
457 -- in the enclosing generic unit. This applies in particular to legality
458 -- checks on actuals for formal subprograms of the inner instance, which
459 -- are checked as subprogram renamings, and may be complicated by confusion
460 -- in private/full views. This function returns the instance enclosing the
461 -- current one if there is such, else it returns Empty.
463 -- If the renaming determines the entity for the default of a formal
464 -- subprogram nested within another instance, choose the innermost
465 -- candidate. This is because if the formal has a box, and we are within
466 -- an enclosing instance where some candidate interpretations are local
467 -- to this enclosing instance, we know that the default was properly
468 -- resolved when analyzing the generic, so we prefer the local
469 -- candidates to those that are external. This is not always the case
470 -- but is a reasonable heuristic on the use of nested generics. The
471 -- proper solution requires a full renaming model.
473 function Has_Implicit_Character_Literal (N : Node_Id) return Boolean;
474 -- Find a type derived from Character or Wide_Character in the prefix of N.
475 -- Used to resolved qualified names whose selector is a character literal.
477 function Has_Private_With (E : Entity_Id) return Boolean;
478 -- Ada 2005 (AI-262): Determines if the current compilation unit has a
479 -- private with on E.
481 procedure Find_Expanded_Name (N : Node_Id);
482 -- The input is a selected component known to be an expanded name. Verify
483 -- legality of selector given the scope denoted by prefix, and change node
484 -- N into a expanded name with a properly set Entity field.
486 function Find_Renamed_Entity
490 Is_Actual : Boolean := False) return Entity_Id;
491 -- Find the renamed entity that corresponds to the given parameter profile
492 -- in a subprogram renaming declaration. The renamed entity may be an
493 -- operator, a subprogram, an entry, or a protected operation. Is_Actual
494 -- indicates that the renaming is the one generated for an actual subpro-
495 -- gram in an instance, for which special visibility checks apply.
497 function Has_Implicit_Operator (N : Node_Id) return Boolean;
498 -- N is an expanded name whose selector is an operator name (e.g. P."+").
499 -- declarative part contains an implicit declaration of an operator if it
500 -- has a declaration of a type to which one of the predefined operators
501 -- apply. The existence of this routine is an implementation artifact. A
502 -- more straightforward but more space-consuming choice would be to make
503 -- all inherited operators explicit in the symbol table.
505 procedure Inherit_Renamed_Profile (New_S : Entity_Id; Old_S : Entity_Id);
506 -- A subprogram defined by a renaming declaration inherits the parameter
507 -- profile of the renamed entity. The subtypes given in the subprogram
508 -- specification are discarded and replaced with those of the renamed
509 -- subprogram, which are then used to recheck the default values.
511 function Is_Appropriate_For_Record (T : Entity_Id) return Boolean;
512 -- Prefix is appropriate for record if it is of a record type, or an access
515 function Is_Appropriate_For_Entry_Prefix (T : Entity_Id) return Boolean;
516 -- True if it is of a task type, a protected type, or else an access to one
519 procedure Note_Redundant_Use (Clause : Node_Id);
520 -- Mark the name in a use clause as redundant if the corresponding entity
521 -- is already use-visible. Emit a warning if the use clause comes from
522 -- source and the proper warnings are enabled.
524 procedure Premature_Usage (N : Node_Id);
525 -- Diagnose usage of an entity before it is visible
527 procedure Use_One_Package (P : Entity_Id; N : Node_Id);
528 -- Make visible entities declared in package P potentially use-visible
529 -- in the current context. Also used in the analysis of subunits, when
530 -- re-installing use clauses of parent units. N is the use_clause that
531 -- names P (and possibly other packages).
533 procedure Use_One_Type (Id : Node_Id; Installed : Boolean := False);
534 -- Id is the subtype mark from a use type clause. This procedure makes
535 -- the primitive operators of the type potentially use-visible. The
536 -- boolean flag Installed indicates that the clause is being reinstalled
537 -- after previous analysis, and primitive operations are already chained
538 -- on the Used_Operations list of the clause.
540 procedure Write_Info;
541 -- Write debugging information on entities declared in current scope
543 --------------------------------
544 -- Analyze_Exception_Renaming --
545 --------------------------------
547 -- The language only allows a single identifier, but the tree holds an
548 -- identifier list. The parser has already issued an error message if
549 -- there is more than one element in the list.
551 procedure Analyze_Exception_Renaming (N : Node_Id) is
552 Id : constant Entity_Id := Defining_Entity (N);
553 Nam : constant Node_Id := Name (N);
556 Check_SPARK_05_Restriction ("exception renaming is not allowed", N);
561 Set_Ekind (Id, E_Exception);
562 Set_Etype (Id, Standard_Exception_Type);
563 Set_Is_Pure (Id, Is_Pure (Current_Scope));
565 if Is_Entity_Name (Nam)
566 and then Present (Entity (Nam))
567 and then Ekind (Entity (Nam)) = E_Exception
569 if Present (Renamed_Object (Entity (Nam))) then
570 Set_Renamed_Object (Id, Renamed_Object (Entity (Nam)));
572 Set_Renamed_Object (Id, Entity (Nam));
575 -- The exception renaming declaration may become Ghost if it renames
578 Mark_Ghost_Renaming (N, Entity (Nam));
580 Error_Msg_N ("invalid exception name in renaming", Nam);
583 -- Implementation-defined aspect specifications can appear in a renaming
584 -- declaration, but not language-defined ones. The call to procedure
585 -- Analyze_Aspect_Specifications will take care of this error check.
587 if Has_Aspects (N) then
588 Analyze_Aspect_Specifications (N, Id);
590 end Analyze_Exception_Renaming;
592 ---------------------------
593 -- Analyze_Expanded_Name --
594 ---------------------------
596 procedure Analyze_Expanded_Name (N : Node_Id) is
598 -- If the entity pointer is already set, this is an internal node, or a
599 -- node that is analyzed more than once, after a tree modification. In
600 -- such a case there is no resolution to perform, just set the type. In
601 -- either case, start by analyzing the prefix.
603 Analyze (Prefix (N));
605 if Present (Entity (N)) then
606 if Is_Type (Entity (N)) then
607 Set_Etype (N, Entity (N));
609 Set_Etype (N, Etype (Entity (N)));
613 Find_Expanded_Name (N);
616 -- In either case, propagate dimension of entity to expanded name
618 Analyze_Dimension (N);
619 end Analyze_Expanded_Name;
621 ---------------------------------------
622 -- Analyze_Generic_Function_Renaming --
623 ---------------------------------------
625 procedure Analyze_Generic_Function_Renaming (N : Node_Id) is
627 Analyze_Generic_Renaming (N, E_Generic_Function);
628 end Analyze_Generic_Function_Renaming;
630 --------------------------------------
631 -- Analyze_Generic_Package_Renaming --
632 --------------------------------------
634 procedure Analyze_Generic_Package_Renaming (N : Node_Id) is
636 -- Test for the Text_IO special unit case here, since we may be renaming
637 -- one of the subpackages of Text_IO, then join common routine.
639 Check_Text_IO_Special_Unit (Name (N));
641 Analyze_Generic_Renaming (N, E_Generic_Package);
642 end Analyze_Generic_Package_Renaming;
644 ----------------------------------------
645 -- Analyze_Generic_Procedure_Renaming --
646 ----------------------------------------
648 procedure Analyze_Generic_Procedure_Renaming (N : Node_Id) is
650 Analyze_Generic_Renaming (N, E_Generic_Procedure);
651 end Analyze_Generic_Procedure_Renaming;
653 ------------------------------
654 -- Analyze_Generic_Renaming --
655 ------------------------------
657 procedure Analyze_Generic_Renaming
661 New_P : constant Entity_Id := Defining_Entity (N);
662 Inst : Boolean := False;
666 if Name (N) = Error then
670 Check_SPARK_05_Restriction ("generic renaming is not allowed", N);
672 Generate_Definition (New_P);
674 if Current_Scope /= Standard_Standard then
675 Set_Is_Pure (New_P, Is_Pure (Current_Scope));
678 if Nkind (Name (N)) = N_Selected_Component then
679 Check_Generic_Child_Unit (Name (N), Inst);
684 if not Is_Entity_Name (Name (N)) then
685 Error_Msg_N ("expect entity name in renaming declaration", Name (N));
688 Old_P := Entity (Name (N));
692 Set_Ekind (New_P, K);
694 if Etype (Old_P) = Any_Type then
697 elsif Ekind (Old_P) /= K then
698 Error_Msg_N ("invalid generic unit name", Name (N));
701 if Present (Renamed_Object (Old_P)) then
702 Set_Renamed_Object (New_P, Renamed_Object (Old_P));
704 Set_Renamed_Object (New_P, Old_P);
707 -- The generic renaming declaration may become Ghost if it renames a
710 Mark_Ghost_Renaming (N, Old_P);
712 Set_Is_Pure (New_P, Is_Pure (Old_P));
713 Set_Is_Preelaborated (New_P, Is_Preelaborated (Old_P));
715 Set_Etype (New_P, Etype (Old_P));
716 Set_Has_Completion (New_P);
718 if In_Open_Scopes (Old_P) then
719 Error_Msg_N ("within its scope, generic denotes its instance", N);
722 -- For subprograms, propagate the Intrinsic flag, to allow, e.g.
723 -- renamings and subsequent instantiations of Unchecked_Conversion.
725 if Ekind_In (Old_P, E_Generic_Function, E_Generic_Procedure) then
726 Set_Is_Intrinsic_Subprogram
727 (New_P, Is_Intrinsic_Subprogram (Old_P));
730 Check_Library_Unit_Renaming (N, Old_P);
733 -- Implementation-defined aspect specifications can appear in a renaming
734 -- declaration, but not language-defined ones. The call to procedure
735 -- Analyze_Aspect_Specifications will take care of this error check.
737 if Has_Aspects (N) then
738 Analyze_Aspect_Specifications (N, New_P);
740 end Analyze_Generic_Renaming;
742 -----------------------------
743 -- Analyze_Object_Renaming --
744 -----------------------------
746 procedure Analyze_Object_Renaming (N : Node_Id) is
747 Id : constant Entity_Id := Defining_Identifier (N);
748 Loc : constant Source_Ptr := Sloc (N);
749 Nam : constant Node_Id := Name (N);
754 procedure Check_Constrained_Object;
755 -- If the nominal type is unconstrained but the renamed object is
756 -- constrained, as can happen with renaming an explicit dereference or
757 -- a function return, build a constrained subtype from the object. If
758 -- the renaming is for a formal in an accept statement, the analysis
759 -- has already established its actual subtype. This is only relevant
760 -- if the renamed object is an explicit dereference.
762 ------------------------------
763 -- Check_Constrained_Object --
764 ------------------------------
766 procedure Check_Constrained_Object is
767 Typ : constant Entity_Id := Etype (Nam);
771 if Nkind_In (Nam, N_Function_Call, N_Explicit_Dereference)
772 and then Is_Composite_Type (Etype (Nam))
773 and then not Is_Constrained (Etype (Nam))
774 and then not Has_Unknown_Discriminants (Etype (Nam))
775 and then Expander_Active
777 -- If Actual_Subtype is already set, nothing to do
779 if Ekind_In (Id, E_Variable, E_Constant)
780 and then Present (Actual_Subtype (Id))
784 -- A renaming of an unchecked union has no actual subtype
786 elsif Is_Unchecked_Union (Typ) then
789 -- If a record is limited its size is invariant. This is the case
790 -- in particular with record types with an access discirminant
791 -- that are used in iterators. This is an optimization, but it
792 -- also prevents typing anomalies when the prefix is further
793 -- expanded. Limited types with discriminants are included.
795 elsif Is_Limited_Record (Typ)
797 (Ekind (Typ) = E_Limited_Private_Type
798 and then Has_Discriminants (Typ)
799 and then Is_Access_Type (Etype (First_Discriminant (Typ))))
804 Subt := Make_Temporary (Loc, 'T');
805 Remove_Side_Effects (Nam);
807 Make_Subtype_Declaration (Loc,
808 Defining_Identifier => Subt,
809 Subtype_Indication =>
810 Make_Subtype_From_Expr (Nam, Typ)));
811 Rewrite (Subtype_Mark (N), New_Occurrence_Of (Subt, Loc));
812 Set_Etype (Nam, Subt);
814 -- Freeze subtype at once, to prevent order of elaboration
815 -- issues in the backend. The renamed object exists, so its
816 -- type is already frozen in any case.
818 Freeze_Before (N, Subt);
821 end Check_Constrained_Object;
823 -- Start of processing for Analyze_Object_Renaming
830 Check_SPARK_05_Restriction ("object renaming is not allowed", N);
832 Set_Is_Pure (Id, Is_Pure (Current_Scope));
835 -- The renaming of a component that depends on a discriminant requires
836 -- an actual subtype, because in subsequent use of the object Gigi will
837 -- be unable to locate the actual bounds. This explicit step is required
838 -- when the renaming is generated in removing side effects of an
839 -- already-analyzed expression.
841 if Nkind (Nam) = N_Selected_Component and then Analyzed (Nam) then
843 -- The object renaming declaration may become Ghost if it renames a
846 if Is_Entity_Name (Nam) then
847 Mark_Ghost_Renaming (N, Entity (Nam));
851 Dec := Build_Actual_Subtype_Of_Component (Etype (Nam), Nam);
853 if Present (Dec) then
854 Insert_Action (N, Dec);
855 T := Defining_Identifier (Dec);
859 -- Complete analysis of the subtype mark in any case, for ASIS use
861 if Present (Subtype_Mark (N)) then
862 Find_Type (Subtype_Mark (N));
865 elsif Present (Subtype_Mark (N)) then
866 Find_Type (Subtype_Mark (N));
867 T := Entity (Subtype_Mark (N));
870 -- The object renaming declaration may become Ghost if it renames a
873 if Is_Entity_Name (Nam) then
874 Mark_Ghost_Renaming (N, Entity (Nam));
877 -- Reject renamings of conversions unless the type is tagged, or
878 -- the conversion is implicit (which can occur for cases of anonymous
879 -- access types in Ada 2012).
881 if Nkind (Nam) = N_Type_Conversion
882 and then Comes_From_Source (Nam)
883 and then not Is_Tagged_Type (T)
886 ("renaming of conversion only allowed for tagged types", Nam);
891 -- If the renamed object is a function call of a limited type,
892 -- the expansion of the renaming is complicated by the presence
893 -- of various temporaries and subtypes that capture constraints
894 -- of the renamed object. Rewrite node as an object declaration,
895 -- whose expansion is simpler. Given that the object is limited
896 -- there is no copy involved and no performance hit.
898 if Nkind (Nam) = N_Function_Call
899 and then Is_Limited_View (Etype (Nam))
900 and then not Is_Constrained (Etype (Nam))
901 and then Comes_From_Source (N)
904 Set_Ekind (Id, E_Constant);
906 Make_Object_Declaration (Loc,
907 Defining_Identifier => Id,
908 Constant_Present => True,
909 Object_Definition => New_Occurrence_Of (Etype (Nam), Loc),
910 Expression => Relocate_Node (Nam)));
914 -- Ada 2012 (AI05-149): Reject renaming of an anonymous access object
915 -- when renaming declaration has a named access type. The Ada 2012
916 -- coverage rules allow an anonymous access type in the context of
917 -- an expected named general access type, but the renaming rules
918 -- require the types to be the same. (An exception is when the type
919 -- of the renaming is also an anonymous access type, which can only
920 -- happen due to a renaming created by the expander.)
922 if Nkind (Nam) = N_Type_Conversion
923 and then not Comes_From_Source (Nam)
924 and then Ekind (Etype (Expression (Nam))) = E_Anonymous_Access_Type
925 and then Ekind (T) /= E_Anonymous_Access_Type
927 Wrong_Type (Expression (Nam), T); -- Should we give better error???
930 -- Check that a class-wide object is not being renamed as an object
931 -- of a specific type. The test for access types is needed to exclude
932 -- cases where the renamed object is a dynamically tagged access
933 -- result, such as occurs in certain expansions.
935 if Is_Tagged_Type (T) then
936 Check_Dynamically_Tagged_Expression
942 -- Ada 2005 (AI-230/AI-254): Access renaming
944 else pragma Assert (Present (Access_Definition (N)));
948 N => Access_Definition (N));
952 -- The object renaming declaration may become Ghost if it renames a
955 if Is_Entity_Name (Nam) then
956 Mark_Ghost_Renaming (N, Entity (Nam));
959 -- Ada 2005 AI05-105: if the declaration has an anonymous access
960 -- type, the renamed object must also have an anonymous type, and
961 -- this is a name resolution rule. This was implicit in the last part
962 -- of the first sentence in 8.5.1(3/2), and is made explicit by this
965 if not Is_Overloaded (Nam) then
966 if Ekind (Etype (Nam)) /= Ekind (T) then
968 ("expect anonymous access type in object renaming", N);
975 Typ : Entity_Id := Empty;
976 Seen : Boolean := False;
979 Get_First_Interp (Nam, I, It);
980 while Present (It.Typ) loop
982 -- Renaming is ambiguous if more than one candidate
983 -- interpretation is type-conformant with the context.
985 if Ekind (It.Typ) = Ekind (T) then
986 if Ekind (T) = E_Anonymous_Access_Subprogram_Type
989 (Designated_Type (T), Designated_Type (It.Typ))
995 ("ambiguous expression in renaming", Nam);
998 elsif Ekind (T) = E_Anonymous_Access_Type
1000 Covers (Designated_Type (T), Designated_Type (It.Typ))
1006 ("ambiguous expression in renaming", Nam);
1010 if Covers (T, It.Typ) then
1012 Set_Etype (Nam, Typ);
1013 Set_Is_Overloaded (Nam, False);
1017 Get_Next_Interp (I, It);
1024 -- Do not perform the legality checks below when the resolution of
1025 -- the renaming name failed because the associated type is Any_Type.
1027 if Etype (Nam) = Any_Type then
1030 -- Ada 2005 (AI-231): In the case where the type is defined by an
1031 -- access_definition, the renamed entity shall be of an access-to-
1032 -- constant type if and only if the access_definition defines an
1033 -- access-to-constant type. ARM 8.5.1(4)
1035 elsif Constant_Present (Access_Definition (N))
1036 and then not Is_Access_Constant (Etype (Nam))
1039 ("(Ada 2005): the renamed object is not access-to-constant "
1040 & "(RM 8.5.1(6))", N);
1042 elsif not Constant_Present (Access_Definition (N))
1043 and then Is_Access_Constant (Etype (Nam))
1046 ("(Ada 2005): the renamed object is not access-to-variable "
1047 & "(RM 8.5.1(6))", N);
1050 if Is_Access_Subprogram_Type (Etype (Nam)) then
1051 Check_Subtype_Conformant
1052 (Designated_Type (T), Designated_Type (Etype (Nam)));
1054 elsif not Subtypes_Statically_Match
1055 (Designated_Type (T),
1056 Available_View (Designated_Type (Etype (Nam))))
1059 ("subtype of renamed object does not statically match", N);
1063 -- Special processing for renaming function return object. Some errors
1064 -- and warnings are produced only for calls that come from source.
1066 if Nkind (Nam) = N_Function_Call then
1069 -- Usage is illegal in Ada 83, but renamings are also introduced
1070 -- during expansion, and error does not apply to those.
1073 if Comes_From_Source (N) then
1075 ("(Ada 83) cannot rename function return object", Nam);
1078 -- In Ada 95, warn for odd case of renaming parameterless function
1079 -- call if this is not a limited type (where this is useful).
1082 if Warn_On_Object_Renames_Function
1083 and then No (Parameter_Associations (Nam))
1084 and then not Is_Limited_Type (Etype (Nam))
1085 and then Comes_From_Source (Nam)
1088 ("renaming function result object is suspicious?R?", Nam);
1090 ("\function & will be called only once?R?", Nam,
1091 Entity (Name (Nam)));
1092 Error_Msg_N -- CODEFIX
1093 ("\suggest using an initialized constant "
1094 & "object instead?R?", Nam);
1099 Check_Constrained_Object;
1101 -- An object renaming requires an exact match of the type. Class-wide
1102 -- matching is not allowed.
1104 if Is_Class_Wide_Type (T)
1105 and then Base_Type (Etype (Nam)) /= Base_Type (T)
1107 Wrong_Type (Nam, T);
1112 -- Ada 2005 (AI-326): Handle wrong use of incomplete type
1114 if Nkind (Nam) = N_Explicit_Dereference
1115 and then Ekind (Etype (T2)) = E_Incomplete_Type
1117 Error_Msg_NE ("invalid use of incomplete type&", Id, T2);
1120 elsif Ekind (Etype (T)) = E_Incomplete_Type then
1121 Error_Msg_NE ("invalid use of incomplete type&", Id, T);
1125 -- Ada 2005 (AI-327)
1127 if Ada_Version >= Ada_2005
1128 and then Nkind (Nam) = N_Attribute_Reference
1129 and then Attribute_Name (Nam) = Name_Priority
1133 elsif Ada_Version >= Ada_2005 and then Nkind (Nam) in N_Has_Entity then
1136 Nam_Ent : Entity_Id;
1139 if Nkind (Nam) = N_Attribute_Reference then
1140 Nam_Ent := Entity (Prefix (Nam));
1142 Nam_Ent := Entity (Nam);
1145 Nam_Decl := Parent (Nam_Ent);
1147 if Has_Null_Exclusion (N)
1148 and then not Has_Null_Exclusion (Nam_Decl)
1150 -- Ada 2005 (AI-423): If the object name denotes a generic
1151 -- formal object of a generic unit G, and the object renaming
1152 -- declaration occurs within the body of G or within the body
1153 -- of a generic unit declared within the declarative region
1154 -- of G, then the declaration of the formal object of G must
1155 -- have a null exclusion or a null-excluding subtype.
1157 if Is_Formal_Object (Nam_Ent)
1158 and then In_Generic_Scope (Id)
1160 if not Can_Never_Be_Null (Etype (Nam_Ent)) then
1162 ("renamed formal does not exclude `NULL` "
1163 & "(RM 8.5.1(4.6/2))", N);
1165 elsif In_Package_Body (Scope (Id)) then
1167 ("formal object does not have a null exclusion"
1168 & "(RM 8.5.1(4.6/2))", N);
1171 -- Ada 2005 (AI-423): Otherwise, the subtype of the object name
1172 -- shall exclude null.
1174 elsif not Can_Never_Be_Null (Etype (Nam_Ent)) then
1176 ("renamed object does not exclude `NULL` "
1177 & "(RM 8.5.1(4.6/2))", N);
1179 -- An instance is illegal if it contains a renaming that
1180 -- excludes null, and the actual does not. The renaming
1181 -- declaration has already indicated that the declaration
1182 -- of the renamed actual in the instance will raise
1183 -- constraint_error.
1185 elsif Nkind (Nam_Decl) = N_Object_Declaration
1186 and then In_Instance
1188 Present (Corresponding_Generic_Association (Nam_Decl))
1189 and then Nkind (Expression (Nam_Decl)) =
1190 N_Raise_Constraint_Error
1193 ("renamed actual does not exclude `NULL` "
1194 & "(RM 8.5.1(4.6/2))", N);
1196 -- Finally, if there is a null exclusion, the subtype mark
1197 -- must not be null-excluding.
1199 elsif No (Access_Definition (N))
1200 and then Can_Never_Be_Null (T)
1203 ("`NOT NULL` not allowed (& already excludes null)",
1208 elsif Can_Never_Be_Null (T)
1209 and then not Can_Never_Be_Null (Etype (Nam_Ent))
1212 ("renamed object does not exclude `NULL` "
1213 & "(RM 8.5.1(4.6/2))", N);
1215 elsif Has_Null_Exclusion (N)
1216 and then No (Access_Definition (N))
1217 and then Can_Never_Be_Null (T)
1220 ("`NOT NULL` not allowed (& already excludes null)", N, T);
1225 -- Set the Ekind of the entity, unless it has been set already, as is
1226 -- the case for the iteration object over a container with no variable
1227 -- indexing. In that case it's been marked as a constant, and we do not
1228 -- want to change it to a variable.
1230 if Ekind (Id) /= E_Constant then
1231 Set_Ekind (Id, E_Variable);
1234 -- Initialize the object size and alignment. Note that we used to call
1235 -- Init_Size_Align here, but that's wrong for objects which have only
1236 -- an Esize, not an RM_Size field.
1238 Init_Object_Size_Align (Id);
1240 if T = Any_Type or else Etype (Nam) = Any_Type then
1243 -- Verify that the renamed entity is an object or a function call. It
1244 -- may have been rewritten in several ways.
1246 elsif Is_Object_Reference (Nam) then
1247 if Comes_From_Source (N) then
1248 if Is_Dependent_Component_Of_Mutable_Object (Nam) then
1250 ("illegal renaming of discriminant-dependent component", Nam);
1253 -- If the renaming comes from source and the renamed object is a
1254 -- dereference, then mark the prefix as needing debug information,
1255 -- since it might have been rewritten hence internally generated
1256 -- and Debug_Renaming_Declaration will link the renaming to it.
1258 if Nkind (Nam) = N_Explicit_Dereference
1259 and then Is_Entity_Name (Prefix (Nam))
1261 Set_Debug_Info_Needed (Entity (Prefix (Nam)));
1265 -- A static function call may have been folded into a literal
1267 elsif Nkind (Original_Node (Nam)) = N_Function_Call
1269 -- When expansion is disabled, attribute reference is not rewritten
1270 -- as function call. Otherwise it may be rewritten as a conversion,
1271 -- so check original node.
1273 or else (Nkind (Original_Node (Nam)) = N_Attribute_Reference
1274 and then Is_Function_Attribute_Name
1275 (Attribute_Name (Original_Node (Nam))))
1277 -- Weird but legal, equivalent to renaming a function call. Illegal
1278 -- if the literal is the result of constant-folding an attribute
1279 -- reference that is not a function.
1281 or else (Is_Entity_Name (Nam)
1282 and then Ekind (Entity (Nam)) = E_Enumeration_Literal
1284 Nkind (Original_Node (Nam)) /= N_Attribute_Reference)
1286 or else (Nkind (Nam) = N_Type_Conversion
1287 and then Is_Tagged_Type (Entity (Subtype_Mark (Nam))))
1291 elsif Nkind (Nam) = N_Type_Conversion then
1293 ("renaming of conversion only allowed for tagged types", Nam);
1295 -- Ada 2005 (AI-327)
1297 elsif Ada_Version >= Ada_2005
1298 and then Nkind (Nam) = N_Attribute_Reference
1299 and then Attribute_Name (Nam) = Name_Priority
1303 -- Allow internally generated x'Ref resulting in N_Reference node
1305 elsif Nkind (Nam) = N_Reference then
1309 Error_Msg_N ("expect object name in renaming", Nam);
1314 if not Is_Variable (Nam) then
1315 Set_Ekind (Id, E_Constant);
1316 Set_Never_Set_In_Source (Id, True);
1317 Set_Is_True_Constant (Id, True);
1320 -- The entity of the renaming declaration needs to reflect whether the
1321 -- renamed object is volatile. Is_Volatile is set if the renamed object
1322 -- is volatile in the RM legality sense.
1324 Set_Is_Volatile (Id, Is_Volatile_Object (Nam));
1326 -- Also copy settings of Atomic/Independent/Volatile_Full_Access
1328 if Is_Entity_Name (Nam) then
1329 Set_Is_Atomic (Id, Is_Atomic (Entity (Nam)));
1330 Set_Is_Independent (Id, Is_Independent (Entity (Nam)));
1331 Set_Is_Volatile_Full_Access (Id,
1332 Is_Volatile_Full_Access (Entity (Nam)));
1335 -- Treat as volatile if we just set the Volatile flag
1339 -- Or if we are renaming an entity which was marked this way
1341 -- Are there more cases, e.g. X(J) where X is Treat_As_Volatile ???
1343 or else (Is_Entity_Name (Nam)
1344 and then Treat_As_Volatile (Entity (Nam)))
1346 Set_Treat_As_Volatile (Id, True);
1349 -- Now make the link to the renamed object
1351 Set_Renamed_Object (Id, Nam);
1353 -- Implementation-defined aspect specifications can appear in a renaming
1354 -- declaration, but not language-defined ones. The call to procedure
1355 -- Analyze_Aspect_Specifications will take care of this error check.
1357 if Has_Aspects (N) then
1358 Analyze_Aspect_Specifications (N, Id);
1361 -- Deal with dimensions
1363 Analyze_Dimension (N);
1364 end Analyze_Object_Renaming;
1366 ------------------------------
1367 -- Analyze_Package_Renaming --
1368 ------------------------------
1370 procedure Analyze_Package_Renaming (N : Node_Id) is
1371 New_P : constant Entity_Id := Defining_Entity (N);
1376 if Name (N) = Error then
1380 -- Check for Text_IO special unit (we may be renaming a Text_IO child)
1382 Check_Text_IO_Special_Unit (Name (N));
1384 if Current_Scope /= Standard_Standard then
1385 Set_Is_Pure (New_P, Is_Pure (Current_Scope));
1391 if Is_Entity_Name (Name (N)) then
1392 Old_P := Entity (Name (N));
1397 if Etype (Old_P) = Any_Type then
1398 Error_Msg_N ("expect package name in renaming", Name (N));
1400 elsif Ekind (Old_P) /= E_Package
1401 and then not (Ekind (Old_P) = E_Generic_Package
1402 and then In_Open_Scopes (Old_P))
1404 if Ekind (Old_P) = E_Generic_Package then
1406 ("generic package cannot be renamed as a package", Name (N));
1408 Error_Msg_Sloc := Sloc (Old_P);
1410 ("expect package name in renaming, found& declared#",
1414 -- Set basic attributes to minimize cascaded errors
1416 Set_Ekind (New_P, E_Package);
1417 Set_Etype (New_P, Standard_Void_Type);
1419 -- Here for OK package renaming
1422 -- Entities in the old package are accessible through the renaming
1423 -- entity. The simplest implementation is to have both packages share
1426 Set_Ekind (New_P, E_Package);
1427 Set_Etype (New_P, Standard_Void_Type);
1429 if Present (Renamed_Object (Old_P)) then
1430 Set_Renamed_Object (New_P, Renamed_Object (Old_P));
1432 Set_Renamed_Object (New_P, Old_P);
1435 -- The package renaming declaration may become Ghost if it renames a
1438 Mark_Ghost_Renaming (N, Old_P);
1440 Set_Has_Completion (New_P);
1441 Set_First_Entity (New_P, First_Entity (Old_P));
1442 Set_Last_Entity (New_P, Last_Entity (Old_P));
1443 Set_First_Private_Entity (New_P, First_Private_Entity (Old_P));
1444 Check_Library_Unit_Renaming (N, Old_P);
1445 Generate_Reference (Old_P, Name (N));
1447 -- If the renaming is in the visible part of a package, then we set
1448 -- Renamed_In_Spec for the renamed package, to prevent giving
1449 -- warnings about no entities referenced. Such a warning would be
1450 -- overenthusiastic, since clients can see entities in the renamed
1451 -- package via the visible package renaming.
1454 Ent : constant Entity_Id := Cunit_Entity (Current_Sem_Unit);
1456 if Ekind (Ent) = E_Package
1457 and then not In_Private_Part (Ent)
1458 and then In_Extended_Main_Source_Unit (N)
1459 and then Ekind (Old_P) = E_Package
1461 Set_Renamed_In_Spec (Old_P);
1465 -- If this is the renaming declaration of a package instantiation
1466 -- within itself, it is the declaration that ends the list of actuals
1467 -- for the instantiation. At this point, the subtypes that rename
1468 -- the actuals are flagged as generic, to avoid spurious ambiguities
1469 -- if the actuals for two distinct formals happen to coincide. If
1470 -- the actual is a private type, the subtype has a private completion
1471 -- that is flagged in the same fashion.
1473 -- Resolution is identical to what is was in the original generic.
1474 -- On exit from the generic instance, these are turned into regular
1475 -- subtypes again, so they are compatible with types in their class.
1477 if not Is_Generic_Instance (Old_P) then
1480 Spec := Specification (Unit_Declaration_Node (Old_P));
1483 if Nkind (Spec) = N_Package_Specification
1484 and then Present (Generic_Parent (Spec))
1485 and then Old_P = Current_Scope
1486 and then Chars (New_P) = Chars (Generic_Parent (Spec))
1492 E := First_Entity (Old_P);
1493 while Present (E) and then E /= New_P loop
1495 and then Nkind (Parent (E)) = N_Subtype_Declaration
1497 Set_Is_Generic_Actual_Type (E);
1499 if Is_Private_Type (E)
1500 and then Present (Full_View (E))
1502 Set_Is_Generic_Actual_Type (Full_View (E));
1512 -- Implementation-defined aspect specifications can appear in a renaming
1513 -- declaration, but not language-defined ones. The call to procedure
1514 -- Analyze_Aspect_Specifications will take care of this error check.
1516 if Has_Aspects (N) then
1517 Analyze_Aspect_Specifications (N, New_P);
1519 end Analyze_Package_Renaming;
1521 -------------------------------
1522 -- Analyze_Renamed_Character --
1523 -------------------------------
1525 procedure Analyze_Renamed_Character
1530 C : constant Node_Id := Name (N);
1533 if Ekind (New_S) = E_Function then
1534 Resolve (C, Etype (New_S));
1537 Check_Frozen_Renaming (N, New_S);
1541 Error_Msg_N ("character literal can only be renamed as function", N);
1543 end Analyze_Renamed_Character;
1545 ---------------------------------
1546 -- Analyze_Renamed_Dereference --
1547 ---------------------------------
1549 procedure Analyze_Renamed_Dereference
1554 Nam : constant Node_Id := Name (N);
1555 P : constant Node_Id := Prefix (Nam);
1561 if not Is_Overloaded (P) then
1562 if Ekind (Etype (Nam)) /= E_Subprogram_Type
1563 or else not Type_Conformant (Etype (Nam), New_S)
1565 Error_Msg_N ("designated type does not match specification", P);
1574 Get_First_Interp (Nam, Ind, It);
1576 while Present (It.Nam) loop
1578 if Ekind (It.Nam) = E_Subprogram_Type
1579 and then Type_Conformant (It.Nam, New_S)
1581 if Typ /= Any_Id then
1582 Error_Msg_N ("ambiguous renaming", P);
1589 Get_Next_Interp (Ind, It);
1592 if Typ = Any_Type then
1593 Error_Msg_N ("designated type does not match specification", P);
1598 Check_Frozen_Renaming (N, New_S);
1602 end Analyze_Renamed_Dereference;
1604 ---------------------------
1605 -- Analyze_Renamed_Entry --
1606 ---------------------------
1608 procedure Analyze_Renamed_Entry
1613 Nam : constant Node_Id := Name (N);
1614 Sel : constant Node_Id := Selector_Name (Nam);
1615 Is_Actual : constant Boolean := Present (Corresponding_Formal_Spec (N));
1619 if Entity (Sel) = Any_Id then
1621 -- Selector is undefined on prefix. Error emitted already
1623 Set_Has_Completion (New_S);
1627 -- Otherwise find renamed entity and build body of New_S as a call to it
1629 Old_S := Find_Renamed_Entity (N, Selector_Name (Nam), New_S);
1631 if Old_S = Any_Id then
1632 Error_Msg_N (" no subprogram or entry matches specification", N);
1635 Check_Subtype_Conformant (New_S, Old_S, N);
1636 Generate_Reference (New_S, Defining_Entity (N), 'b');
1637 Style.Check_Identifier (Defining_Entity (N), New_S);
1640 -- Only mode conformance required for a renaming_as_declaration
1642 Check_Mode_Conformant (New_S, Old_S, N);
1645 Inherit_Renamed_Profile (New_S, Old_S);
1647 -- The prefix can be an arbitrary expression that yields a task or
1648 -- protected object, so it must be resolved.
1650 Resolve (Prefix (Nam), Scope (Old_S));
1653 Set_Convention (New_S, Convention (Old_S));
1654 Set_Has_Completion (New_S, Inside_A_Generic);
1656 -- AI05-0225: If the renamed entity is a procedure or entry of a
1657 -- protected object, the target object must be a variable.
1659 if Ekind (Scope (Old_S)) in Protected_Kind
1660 and then Ekind (New_S) = E_Procedure
1661 and then not Is_Variable (Prefix (Nam))
1665 ("target object of protected operation used as actual for "
1666 & "formal procedure must be a variable", Nam);
1669 ("target object of protected operation renamed as procedure, "
1670 & "must be a variable", Nam);
1675 Check_Frozen_Renaming (N, New_S);
1677 end Analyze_Renamed_Entry;
1679 -----------------------------------
1680 -- Analyze_Renamed_Family_Member --
1681 -----------------------------------
1683 procedure Analyze_Renamed_Family_Member
1688 Nam : constant Node_Id := Name (N);
1689 P : constant Node_Id := Prefix (Nam);
1693 if (Is_Entity_Name (P) and then Ekind (Entity (P)) = E_Entry_Family)
1694 or else (Nkind (P) = N_Selected_Component
1695 and then Ekind (Entity (Selector_Name (P))) = E_Entry_Family)
1697 if Is_Entity_Name (P) then
1698 Old_S := Entity (P);
1700 Old_S := Entity (Selector_Name (P));
1703 if not Entity_Matches_Spec (Old_S, New_S) then
1704 Error_Msg_N ("entry family does not match specification", N);
1707 Check_Subtype_Conformant (New_S, Old_S, N);
1708 Generate_Reference (New_S, Defining_Entity (N), 'b');
1709 Style.Check_Identifier (Defining_Entity (N), New_S);
1713 Error_Msg_N ("no entry family matches specification", N);
1716 Set_Has_Completion (New_S, Inside_A_Generic);
1719 Check_Frozen_Renaming (N, New_S);
1721 end Analyze_Renamed_Family_Member;
1723 -----------------------------------------
1724 -- Analyze_Renamed_Primitive_Operation --
1725 -----------------------------------------
1727 procedure Analyze_Renamed_Primitive_Operation
1736 Ctyp : Conformance_Type) return Boolean;
1737 -- Verify that the signatures of the renamed entity and the new entity
1738 -- match. The first formal of the renamed entity is skipped because it
1739 -- is the target object in any subsequent call.
1747 Ctyp : Conformance_Type) return Boolean
1753 if Ekind (Subp) /= Ekind (New_S) then
1757 Old_F := Next_Formal (First_Formal (Subp));
1758 New_F := First_Formal (New_S);
1759 while Present (Old_F) and then Present (New_F) loop
1760 if not Conforming_Types (Etype (Old_F), Etype (New_F), Ctyp) then
1764 if Ctyp >= Mode_Conformant
1765 and then Ekind (Old_F) /= Ekind (New_F)
1770 Next_Formal (New_F);
1771 Next_Formal (Old_F);
1777 -- Start of processing for Analyze_Renamed_Primitive_Operation
1780 if not Is_Overloaded (Selector_Name (Name (N))) then
1781 Old_S := Entity (Selector_Name (Name (N)));
1783 if not Conforms (Old_S, Type_Conformant) then
1788 -- Find the operation that matches the given signature
1796 Get_First_Interp (Selector_Name (Name (N)), Ind, It);
1798 while Present (It.Nam) loop
1799 if Conforms (It.Nam, Type_Conformant) then
1803 Get_Next_Interp (Ind, It);
1808 if Old_S = Any_Id then
1809 Error_Msg_N (" no subprogram or entry matches specification", N);
1813 if not Conforms (Old_S, Subtype_Conformant) then
1814 Error_Msg_N ("subtype conformance error in renaming", N);
1817 Generate_Reference (New_S, Defining_Entity (N), 'b');
1818 Style.Check_Identifier (Defining_Entity (N), New_S);
1821 -- Only mode conformance required for a renaming_as_declaration
1823 if not Conforms (Old_S, Mode_Conformant) then
1824 Error_Msg_N ("mode conformance error in renaming", N);
1827 -- Enforce the rule given in (RM 6.3.1 (10.1/2)): a prefixed
1828 -- view of a subprogram is intrinsic, because the compiler has
1829 -- to generate a wrapper for any call to it. If the name in a
1830 -- subprogram renaming is a prefixed view, the entity is thus
1831 -- intrinsic, and 'Access cannot be applied to it.
1833 Set_Convention (New_S, Convention_Intrinsic);
1836 -- Inherit_Renamed_Profile (New_S, Old_S);
1838 -- The prefix can be an arbitrary expression that yields an
1839 -- object, so it must be resolved.
1841 Resolve (Prefix (Name (N)));
1843 end Analyze_Renamed_Primitive_Operation;
1845 ---------------------------------
1846 -- Analyze_Subprogram_Renaming --
1847 ---------------------------------
1849 procedure Analyze_Subprogram_Renaming (N : Node_Id) is
1850 Formal_Spec : constant Entity_Id := Corresponding_Formal_Spec (N);
1851 Is_Actual : constant Boolean := Present (Formal_Spec);
1852 Nam : constant Node_Id := Name (N);
1853 Save_AV : constant Ada_Version_Type := Ada_Version;
1854 Save_AVP : constant Node_Id := Ada_Version_Pragma;
1855 Save_AV_Exp : constant Ada_Version_Type := Ada_Version_Explicit;
1856 Spec : constant Node_Id := Specification (N);
1858 Old_S : Entity_Id := Empty;
1859 Rename_Spec : Entity_Id;
1861 procedure Build_Class_Wide_Wrapper
1862 (Ren_Id : out Entity_Id;
1863 Wrap_Id : out Entity_Id);
1864 -- Ada 2012 (AI05-0071): A generic/instance scenario involving a formal
1865 -- type with unknown discriminants and a generic primitive operation of
1866 -- the said type with a box require special processing when the actual
1867 -- is a class-wide type:
1870 -- type Formal_Typ (<>) is private;
1871 -- with procedure Prim_Op (Param : Formal_Typ) is <>;
1872 -- package Gen is ...
1874 -- package Inst is new Gen (Actual_Typ'Class);
1876 -- In this case the general renaming mechanism used in the prologue of
1877 -- an instance no longer applies:
1879 -- procedure Prim_Op (Param : Formal_Typ) renames Prim_Op;
1881 -- The above is replaced the following wrapper/renaming combination:
1883 -- procedure Wrapper (Param : Formal_Typ) is -- wrapper
1885 -- Prim_Op (Param); -- primitive
1888 -- procedure Prim_Op (Param : Formal_Typ) renames Wrapper;
1890 -- This transformation applies only if there is no explicit visible
1891 -- class-wide operation at the point of the instantiation. Ren_Id is
1892 -- the entity of the renaming declaration. When the transformation
1893 -- applies, Wrap_Id is the entity of the generated class-wide wrapper
1894 -- (or Any_Id). Otherwise, Wrap_Id is the entity of the class-wide
1897 procedure Check_Null_Exclusion
1900 -- Ada 2005 (AI-423): Given renaming Ren of subprogram Sub, check the
1901 -- following AI rules:
1903 -- If Ren is a renaming of a formal subprogram and one of its
1904 -- parameters has a null exclusion, then the corresponding formal
1905 -- in Sub must also have one. Otherwise the subtype of the Sub's
1906 -- formal parameter must exclude null.
1908 -- If Ren is a renaming of a formal function and its return
1909 -- profile has a null exclusion, then Sub's return profile must
1910 -- have one. Otherwise the subtype of Sub's return profile must
1913 procedure Freeze_Actual_Profile;
1914 -- In Ada 2012, enforce the freezing rule concerning formal incomplete
1915 -- types: a callable entity freezes its profile, unless it has an
1916 -- incomplete untagged formal (RM 13.14(10.2/3)).
1918 function Has_Class_Wide_Actual return Boolean;
1919 -- Ada 2012 (AI05-071, AI05-0131): True if N is the renaming for a
1920 -- defaulted formal subprogram where the actual for the controlling
1921 -- formal type is class-wide.
1923 function Original_Subprogram (Subp : Entity_Id) return Entity_Id;
1924 -- Find renamed entity when the declaration is a renaming_as_body and
1925 -- the renamed entity may itself be a renaming_as_body. Used to enforce
1926 -- rule that a renaming_as_body is illegal if the declaration occurs
1927 -- before the subprogram it completes is frozen, and renaming indirectly
1928 -- renames the subprogram itself.(Defect Report 8652/0027).
1930 ------------------------------
1931 -- Build_Class_Wide_Wrapper --
1932 ------------------------------
1934 procedure Build_Class_Wide_Wrapper
1935 (Ren_Id : out Entity_Id;
1936 Wrap_Id : out Entity_Id)
1938 Loc : constant Source_Ptr := Sloc (N);
1941 (Subp_Id : Entity_Id;
1942 Params : List_Id) return Node_Id;
1943 -- Create a dispatching call to invoke routine Subp_Id with actuals
1944 -- built from the parameter specifications of list Params.
1946 function Build_Expr_Fun_Call
1947 (Subp_Id : Entity_Id;
1948 Params : List_Id) return Node_Id;
1949 -- Create a dispatching call to invoke function Subp_Id with actuals
1950 -- built from the parameter specifications of list Params. Return
1951 -- directly the call, so that it can be used inside an expression
1952 -- function. This is a specificity of the GNATprove mode.
1954 function Build_Spec (Subp_Id : Entity_Id) return Node_Id;
1955 -- Create a subprogram specification based on the subprogram profile
1958 function Find_Primitive (Typ : Entity_Id) return Entity_Id;
1959 -- Find a primitive subprogram of type Typ which matches the profile
1960 -- of the renaming declaration.
1962 procedure Interpretation_Error (Subp_Id : Entity_Id);
1963 -- Emit a continuation error message suggesting subprogram Subp_Id as
1964 -- a possible interpretation.
1966 function Is_Intrinsic_Equality (Subp_Id : Entity_Id) return Boolean;
1967 -- Determine whether subprogram Subp_Id denotes the intrinsic "="
1970 function Is_Suitable_Candidate (Subp_Id : Entity_Id) return Boolean;
1971 -- Determine whether subprogram Subp_Id is a suitable candidate for
1972 -- the role of a wrapped subprogram.
1979 (Subp_Id : Entity_Id;
1980 Params : List_Id) return Node_Id
1982 Actuals : constant List_Id := New_List;
1983 Call_Ref : constant Node_Id := New_Occurrence_Of (Subp_Id, Loc);
1987 -- Build the actual parameters of the call
1989 Formal := First (Params);
1990 while Present (Formal) loop
1992 Make_Identifier (Loc, Chars (Defining_Identifier (Formal))));
1997 -- return Subp_Id (Actuals);
1999 if Ekind_In (Subp_Id, E_Function, E_Operator) then
2001 Make_Simple_Return_Statement (Loc,
2003 Make_Function_Call (Loc,
2005 Parameter_Associations => Actuals));
2008 -- Subp_Id (Actuals);
2012 Make_Procedure_Call_Statement (Loc,
2014 Parameter_Associations => Actuals);
2018 -------------------------
2019 -- Build_Expr_Fun_Call --
2020 -------------------------
2022 function Build_Expr_Fun_Call
2023 (Subp_Id : Entity_Id;
2024 Params : List_Id) return Node_Id
2026 Actuals : constant List_Id := New_List;
2027 Call_Ref : constant Node_Id := New_Occurrence_Of (Subp_Id, Loc);
2031 pragma Assert (Ekind_In (Subp_Id, E_Function, E_Operator));
2033 -- Build the actual parameters of the call
2035 Formal := First (Params);
2036 while Present (Formal) loop
2038 Make_Identifier (Loc, Chars (Defining_Identifier (Formal))));
2043 -- Subp_Id (Actuals);
2046 Make_Function_Call (Loc,
2048 Parameter_Associations => Actuals);
2049 end Build_Expr_Fun_Call;
2055 function Build_Spec (Subp_Id : Entity_Id) return Node_Id is
2056 Params : constant List_Id := Copy_Parameter_List (Subp_Id);
2057 Spec_Id : constant Entity_Id :=
2058 Make_Defining_Identifier (Loc,
2059 Chars => New_External_Name (Chars (Subp_Id), 'R'));
2062 if Ekind (Formal_Spec) = E_Procedure then
2064 Make_Procedure_Specification (Loc,
2065 Defining_Unit_Name => Spec_Id,
2066 Parameter_Specifications => Params);
2069 Make_Function_Specification (Loc,
2070 Defining_Unit_Name => Spec_Id,
2071 Parameter_Specifications => Params,
2072 Result_Definition =>
2073 New_Copy_Tree (Result_Definition (Spec)));
2077 --------------------
2078 -- Find_Primitive --
2079 --------------------
2081 function Find_Primitive (Typ : Entity_Id) return Entity_Id is
2082 procedure Replace_Parameter_Types (Spec : Node_Id);
2083 -- Given a specification Spec, replace all class-wide parameter
2084 -- types with reference to type Typ.
2086 -----------------------------
2087 -- Replace_Parameter_Types --
2088 -----------------------------
2090 procedure Replace_Parameter_Types (Spec : Node_Id) is
2092 Formal_Id : Entity_Id;
2093 Formal_Typ : Node_Id;
2096 Formal := First (Parameter_Specifications (Spec));
2097 while Present (Formal) loop
2098 Formal_Id := Defining_Identifier (Formal);
2099 Formal_Typ := Parameter_Type (Formal);
2101 -- Create a new entity for each class-wide formal to prevent
2102 -- aliasing with the original renaming. Replace the type of
2103 -- such a parameter with the candidate type.
2105 if Nkind (Formal_Typ) = N_Identifier
2106 and then Is_Class_Wide_Type (Etype (Formal_Typ))
2108 Set_Defining_Identifier (Formal,
2109 Make_Defining_Identifier (Loc, Chars (Formal_Id)));
2111 Set_Parameter_Type (Formal, New_Occurrence_Of (Typ, Loc));
2116 end Replace_Parameter_Types;
2120 Alt_Ren : constant Node_Id := New_Copy_Tree (N);
2121 Alt_Nam : constant Node_Id := Name (Alt_Ren);
2122 Alt_Spec : constant Node_Id := Specification (Alt_Ren);
2123 Subp_Id : Entity_Id;
2125 -- Start of processing for Find_Primitive
2128 -- Each attempt to find a suitable primitive of a particular type
2129 -- operates on its own copy of the original renaming. As a result
2130 -- the original renaming is kept decoration and side-effect free.
2132 -- Inherit the overloaded status of the renamed subprogram name
2134 if Is_Overloaded (Nam) then
2135 Set_Is_Overloaded (Alt_Nam);
2136 Save_Interps (Nam, Alt_Nam);
2139 -- The copied renaming is hidden from visibility to prevent the
2140 -- pollution of the enclosing context.
2142 Set_Defining_Unit_Name (Alt_Spec, Make_Temporary (Loc, 'R'));
2144 -- The types of all class-wide parameters must be changed to the
2147 Replace_Parameter_Types (Alt_Spec);
2149 -- Try to find a suitable primitive which matches the altered
2150 -- profile of the renaming specification.
2155 Nam => Name (Alt_Ren),
2156 New_S => Analyze_Subprogram_Specification (Alt_Spec),
2157 Is_Actual => Is_Actual);
2159 -- Do not return Any_Id if the resolion of the altered profile
2160 -- failed as this complicates further checks on the caller side,
2161 -- return Empty instead.
2163 if Subp_Id = Any_Id then
2170 --------------------------
2171 -- Interpretation_Error --
2172 --------------------------
2174 procedure Interpretation_Error (Subp_Id : Entity_Id) is
2176 Error_Msg_Sloc := Sloc (Subp_Id);
2178 if Is_Internal (Subp_Id) then
2180 ("\\possible interpretation: predefined & #",
2184 ("\\possible interpretation: & defined #", Spec, Formal_Spec);
2186 end Interpretation_Error;
2188 ---------------------------
2189 -- Is_Intrinsic_Equality --
2190 ---------------------------
2192 function Is_Intrinsic_Equality (Subp_Id : Entity_Id) return Boolean is
2195 Ekind (Subp_Id) = E_Operator
2196 and then Chars (Subp_Id) = Name_Op_Eq
2197 and then Is_Intrinsic_Subprogram (Subp_Id);
2198 end Is_Intrinsic_Equality;
2200 ---------------------------
2201 -- Is_Suitable_Candidate --
2202 ---------------------------
2204 function Is_Suitable_Candidate (Subp_Id : Entity_Id) return Boolean is
2206 if No (Subp_Id) then
2209 -- An intrinsic subprogram is never a good candidate. This is an
2210 -- indication of a missing primitive, either defined directly or
2211 -- inherited from a parent tagged type.
2213 elsif Is_Intrinsic_Subprogram (Subp_Id) then
2219 end Is_Suitable_Candidate;
2223 Actual_Typ : Entity_Id := Empty;
2224 -- The actual class-wide type for Formal_Typ
2226 CW_Prim_OK : Boolean;
2227 CW_Prim_Op : Entity_Id;
2228 -- The class-wide subprogram (if available) which corresponds to the
2229 -- renamed generic formal subprogram.
2231 Formal_Typ : Entity_Id := Empty;
2232 -- The generic formal type with unknown discriminants
2234 Root_Prim_OK : Boolean;
2235 Root_Prim_Op : Entity_Id;
2236 -- The root type primitive (if available) which corresponds to the
2237 -- renamed generic formal subprogram.
2239 Root_Typ : Entity_Id := Empty;
2240 -- The root type of Actual_Typ
2242 Body_Decl : Node_Id;
2244 Prim_Op : Entity_Id;
2245 Spec_Decl : Node_Id;
2248 -- Start of processing for Build_Class_Wide_Wrapper
2251 -- Analyze the specification of the renaming in case the generation
2252 -- of the class-wide wrapper fails.
2254 Ren_Id := Analyze_Subprogram_Specification (Spec);
2257 -- Do not attempt to build a wrapper if the renaming is in error
2259 if Error_Posted (Nam) then
2263 -- Analyze the renamed name, but do not resolve it. The resolution is
2264 -- completed once a suitable subprogram is found.
2268 -- When the renamed name denotes the intrinsic operator equals, the
2269 -- name must be treated as overloaded. This allows for a potential
2270 -- match against the root type's predefined equality function.
2272 if Is_Intrinsic_Equality (Entity (Nam)) then
2273 Set_Is_Overloaded (Nam);
2274 Collect_Interps (Nam);
2277 -- Step 1: Find the generic formal type with unknown discriminants
2278 -- and its corresponding class-wide actual type from the renamed
2279 -- generic formal subprogram.
2281 Formal := First_Formal (Formal_Spec);
2282 while Present (Formal) loop
2283 if Has_Unknown_Discriminants (Etype (Formal))
2284 and then not Is_Class_Wide_Type (Etype (Formal))
2285 and then Is_Class_Wide_Type (Get_Instance_Of (Etype (Formal)))
2287 Formal_Typ := Etype (Formal);
2288 Actual_Typ := Get_Instance_Of (Formal_Typ);
2289 Root_Typ := Etype (Actual_Typ);
2293 Next_Formal (Formal);
2296 -- The specification of the generic formal subprogram should always
2297 -- contain a formal type with unknown discriminants whose actual is
2298 -- a class-wide type, otherwise this indicates a failure in routine
2299 -- Has_Class_Wide_Actual.
2301 pragma Assert (Present (Formal_Typ));
2303 -- Step 2: Find the proper class-wide subprogram or primitive which
2304 -- corresponds to the renamed generic formal subprogram.
2306 CW_Prim_Op := Find_Primitive (Actual_Typ);
2307 CW_Prim_OK := Is_Suitable_Candidate (CW_Prim_Op);
2308 Root_Prim_Op := Find_Primitive (Root_Typ);
2309 Root_Prim_OK := Is_Suitable_Candidate (Root_Prim_Op);
2311 -- The class-wide actual type has two subprograms which correspond to
2312 -- the renamed generic formal subprogram:
2314 -- with procedure Prim_Op (Param : Formal_Typ);
2316 -- procedure Prim_Op (Param : Actual_Typ); -- may be inherited
2317 -- procedure Prim_Op (Param : Actual_Typ'Class);
2319 -- Even though the declaration of the two subprograms is legal, a
2320 -- call to either one is ambiguous and therefore illegal.
2322 if CW_Prim_OK and Root_Prim_OK then
2324 -- A user-defined primitive has precedence over a predefined one
2326 if Is_Internal (CW_Prim_Op)
2327 and then not Is_Internal (Root_Prim_Op)
2329 Prim_Op := Root_Prim_Op;
2331 elsif Is_Internal (Root_Prim_Op)
2332 and then not Is_Internal (CW_Prim_Op)
2334 Prim_Op := CW_Prim_Op;
2336 elsif CW_Prim_Op = Root_Prim_Op then
2337 Prim_Op := Root_Prim_Op;
2339 -- Otherwise both candidate subprograms are user-defined and
2344 ("ambiguous actual for generic subprogram &",
2346 Interpretation_Error (Root_Prim_Op);
2347 Interpretation_Error (CW_Prim_Op);
2351 elsif CW_Prim_OK and not Root_Prim_OK then
2352 Prim_Op := CW_Prim_Op;
2354 elsif not CW_Prim_OK and Root_Prim_OK then
2355 Prim_Op := Root_Prim_Op;
2357 -- An intrinsic equality may act as a suitable candidate in the case
2358 -- of a null type extension where the parent's equality is hidden. A
2359 -- call to an intrinsic equality is expanded as dispatching.
2361 elsif Present (Root_Prim_Op)
2362 and then Is_Intrinsic_Equality (Root_Prim_Op)
2364 Prim_Op := Root_Prim_Op;
2366 -- Otherwise there are no candidate subprograms. Let the caller
2367 -- diagnose the error.
2373 -- At this point resolution has taken place and the name is no longer
2374 -- overloaded. Mark the primitive as referenced.
2376 Set_Is_Overloaded (Name (N), False);
2377 Set_Referenced (Prim_Op);
2379 -- Do not generate a wrapper when the only candidate is a class-wide
2380 -- subprogram. Instead modify the renaming to directly map the actual
2381 -- to the generic formal.
2383 if CW_Prim_OK and then Prim_Op = CW_Prim_Op then
2385 Rewrite (Nam, New_Occurrence_Of (Prim_Op, Loc));
2389 -- Step 3: Create the declaration and the body of the wrapper, insert
2390 -- all the pieces into the tree.
2392 -- In GNATprove mode, create a function wrapper in the form of an
2393 -- expression function, so that an implicit postcondition relating
2394 -- the result of calling the wrapper function and the result of the
2395 -- dispatching call to the wrapped function is known during proof.
2398 and then Ekind_In (Ren_Id, E_Function, E_Operator)
2400 New_Spec := Build_Spec (Ren_Id);
2402 Make_Expression_Function (Loc,
2403 Specification => New_Spec,
2406 (Subp_Id => Prim_Op,
2407 Params => Parameter_Specifications (New_Spec)));
2409 Wrap_Id := Defining_Entity (Body_Decl);
2411 -- Otherwise, create separate spec and body for the subprogram
2415 Make_Subprogram_Declaration (Loc,
2416 Specification => Build_Spec (Ren_Id));
2417 Insert_Before_And_Analyze (N, Spec_Decl);
2419 Wrap_Id := Defining_Entity (Spec_Decl);
2422 Make_Subprogram_Body (Loc,
2423 Specification => Build_Spec (Ren_Id),
2424 Declarations => New_List,
2425 Handled_Statement_Sequence =>
2426 Make_Handled_Sequence_Of_Statements (Loc,
2427 Statements => New_List (
2429 (Subp_Id => Prim_Op,
2431 Parameter_Specifications
2432 (Specification (Spec_Decl))))));
2434 Set_Corresponding_Body (Spec_Decl, Defining_Entity (Body_Decl));
2437 -- If the operator carries an Eliminated pragma, indicate that the
2438 -- wrapper is also to be eliminated, to prevent spurious error when
2439 -- using gnatelim on programs that include box-initialization of
2440 -- equality operators.
2442 Set_Is_Eliminated (Wrap_Id, Is_Eliminated (Prim_Op));
2444 -- In GNATprove mode, insert the body in the tree for analysis
2446 if GNATprove_Mode then
2447 Insert_Before_And_Analyze (N, Body_Decl);
2450 -- The generated body does not freeze and must be analyzed when the
2451 -- class-wide wrapper is frozen. The body is only needed if expansion
2454 if Expander_Active then
2455 Append_Freeze_Action (Wrap_Id, Body_Decl);
2458 -- Step 4: The subprogram renaming aliases the wrapper
2460 Rewrite (Nam, New_Occurrence_Of (Wrap_Id, Loc));
2461 end Build_Class_Wide_Wrapper;
2463 --------------------------
2464 -- Check_Null_Exclusion --
2465 --------------------------
2467 procedure Check_Null_Exclusion
2471 Ren_Formal : Entity_Id;
2472 Sub_Formal : Entity_Id;
2477 Ren_Formal := First_Formal (Ren);
2478 Sub_Formal := First_Formal (Sub);
2479 while Present (Ren_Formal) and then Present (Sub_Formal) loop
2480 if Has_Null_Exclusion (Parent (Ren_Formal))
2482 not (Has_Null_Exclusion (Parent (Sub_Formal))
2483 or else Can_Never_Be_Null (Etype (Sub_Formal)))
2486 ("`NOT NULL` required for parameter &",
2487 Parent (Sub_Formal), Sub_Formal);
2490 Next_Formal (Ren_Formal);
2491 Next_Formal (Sub_Formal);
2494 -- Return profile check
2496 if Nkind (Parent (Ren)) = N_Function_Specification
2497 and then Nkind (Parent (Sub)) = N_Function_Specification
2498 and then Has_Null_Exclusion (Parent (Ren))
2499 and then not (Has_Null_Exclusion (Parent (Sub))
2500 or else Can_Never_Be_Null (Etype (Sub)))
2503 ("return must specify `NOT NULL`",
2504 Result_Definition (Parent (Sub)));
2506 end Check_Null_Exclusion;
2508 ---------------------------
2509 -- Freeze_Actual_Profile --
2510 ---------------------------
2512 procedure Freeze_Actual_Profile is
2514 Has_Untagged_Inc : Boolean;
2515 Instantiation_Node : constant Node_Id := Parent (N);
2518 if Ada_Version >= Ada_2012 then
2519 F := First_Formal (Formal_Spec);
2520 Has_Untagged_Inc := False;
2521 while Present (F) loop
2522 if Ekind (Etype (F)) = E_Incomplete_Type
2523 and then not Is_Tagged_Type (Etype (F))
2525 Has_Untagged_Inc := True;
2529 F := Next_Formal (F);
2532 if Ekind (Formal_Spec) = E_Function
2533 and then not Is_Tagged_Type (Etype (Formal_Spec))
2535 Has_Untagged_Inc := True;
2538 if not Has_Untagged_Inc then
2539 F := First_Formal (Old_S);
2540 while Present (F) loop
2541 Freeze_Before (Instantiation_Node, Etype (F));
2543 if Is_Incomplete_Or_Private_Type (Etype (F))
2544 and then No (Underlying_Type (Etype (F)))
2546 -- Exclude generic types, or types derived from them.
2547 -- They will be frozen in the enclosing instance.
2549 if Is_Generic_Type (Etype (F))
2550 or else Is_Generic_Type (Root_Type (Etype (F)))
2554 -- A limited view of a type declared elsewhere needs no
2555 -- freezing actions.
2557 elsif From_Limited_With (Etype (F)) then
2562 ("type& must be frozen before this point",
2563 Instantiation_Node, Etype (F));
2567 F := Next_Formal (F);
2571 end Freeze_Actual_Profile;
2573 ---------------------------
2574 -- Has_Class_Wide_Actual --
2575 ---------------------------
2577 function Has_Class_Wide_Actual return Boolean is
2579 Formal_Typ : Entity_Id;
2583 Formal := First_Formal (Formal_Spec);
2584 while Present (Formal) loop
2585 Formal_Typ := Etype (Formal);
2587 if Has_Unknown_Discriminants (Formal_Typ)
2588 and then not Is_Class_Wide_Type (Formal_Typ)
2589 and then Is_Class_Wide_Type (Get_Instance_Of (Formal_Typ))
2594 Next_Formal (Formal);
2599 end Has_Class_Wide_Actual;
2601 -------------------------
2602 -- Original_Subprogram --
2603 -------------------------
2605 function Original_Subprogram (Subp : Entity_Id) return Entity_Id is
2606 Orig_Decl : Node_Id;
2607 Orig_Subp : Entity_Id;
2610 -- First case: renamed entity is itself a renaming
2612 if Present (Alias (Subp)) then
2613 return Alias (Subp);
2615 elsif Nkind (Unit_Declaration_Node (Subp)) = N_Subprogram_Declaration
2616 and then Present (Corresponding_Body (Unit_Declaration_Node (Subp)))
2618 -- Check if renamed entity is a renaming_as_body
2621 Unit_Declaration_Node
2622 (Corresponding_Body (Unit_Declaration_Node (Subp)));
2624 if Nkind (Orig_Decl) = N_Subprogram_Renaming_Declaration then
2625 Orig_Subp := Entity (Name (Orig_Decl));
2627 if Orig_Subp = Rename_Spec then
2629 -- Circularity detected
2634 return (Original_Subprogram (Orig_Subp));
2642 end Original_Subprogram;
2646 CW_Actual : constant Boolean := Has_Class_Wide_Actual;
2647 -- Ada 2012 (AI05-071, AI05-0131): True if the renaming is for a
2648 -- defaulted formal subprogram when the actual for a related formal
2649 -- type is class-wide.
2651 Inst_Node : Node_Id := Empty;
2654 -- Start of processing for Analyze_Subprogram_Renaming
2657 -- We must test for the attribute renaming case before the Analyze
2658 -- call because otherwise Sem_Attr will complain that the attribute
2659 -- is missing an argument when it is analyzed.
2661 if Nkind (Nam) = N_Attribute_Reference then
2663 -- In the case of an abstract formal subprogram association, rewrite
2664 -- an actual given by a stream attribute as the name of the
2665 -- corresponding stream primitive of the type.
2667 -- In a generic context the stream operations are not generated, and
2668 -- this must be treated as a normal attribute reference, to be
2669 -- expanded in subsequent instantiations.
2672 and then Is_Abstract_Subprogram (Formal_Spec)
2673 and then Expander_Active
2676 Prefix_Type : constant Entity_Id := Entity (Prefix (Nam));
2677 Stream_Prim : Entity_Id;
2680 -- The class-wide forms of the stream attributes are not
2681 -- primitive dispatching operations (even though they
2682 -- internally dispatch to a stream attribute).
2684 if Is_Class_Wide_Type (Prefix_Type) then
2686 ("attribute must be a primitive dispatching operation",
2691 -- Retrieve the primitive subprogram associated with the
2692 -- attribute. This can only be a stream attribute, since those
2693 -- are the only ones that are dispatching (and the actual for
2694 -- an abstract formal subprogram must be dispatching
2697 case Attribute_Name (Nam) is
2700 Find_Optional_Prim_Op (Prefix_Type, TSS_Stream_Input);
2704 Find_Optional_Prim_Op (Prefix_Type, TSS_Stream_Output);
2708 Find_Optional_Prim_Op (Prefix_Type, TSS_Stream_Read);
2712 Find_Optional_Prim_Op (Prefix_Type, TSS_Stream_Write);
2716 ("attribute must be a primitive dispatching operation",
2721 -- If no operation was found, and the type is limited, the user
2722 -- should have defined one.
2724 if No (Stream_Prim) then
2725 if Is_Limited_Type (Prefix_Type) then
2727 ("stream operation not defined for type&",
2731 -- Otherwise, compiler should have generated default
2734 raise Program_Error;
2738 -- Rewrite the attribute into the name of its corresponding
2739 -- primitive dispatching subprogram. We can then proceed with
2740 -- the usual processing for subprogram renamings.
2743 Prim_Name : constant Node_Id :=
2744 Make_Identifier (Sloc (Nam),
2745 Chars => Chars (Stream_Prim));
2747 Set_Entity (Prim_Name, Stream_Prim);
2748 Rewrite (Nam, Prim_Name);
2753 -- Normal processing for a renaming of an attribute
2756 Attribute_Renaming (N);
2761 -- Check whether this declaration corresponds to the instantiation of a
2762 -- formal subprogram.
2764 -- If this is an instantiation, the corresponding actual is frozen and
2765 -- error messages can be made more precise. If this is a default
2766 -- subprogram, the entity is already established in the generic, and is
2767 -- not retrieved by visibility. If it is a default with a box, the
2768 -- candidate interpretations, if any, have been collected when building
2769 -- the renaming declaration. If overloaded, the proper interpretation is
2770 -- determined in Find_Renamed_Entity. If the entity is an operator,
2771 -- Find_Renamed_Entity applies additional visibility checks.
2774 Inst_Node := Unit_Declaration_Node (Formal_Spec);
2776 -- Check whether the renaming is for a defaulted actual subprogram
2777 -- with a class-wide actual.
2779 -- The class-wide wrapper is not needed in GNATprove_Mode and there
2780 -- is an external axiomatization on the package.
2783 and then Box_Present (Inst_Node)
2787 Present (Containing_Package_With_Ext_Axioms (Formal_Spec)))
2789 Build_Class_Wide_Wrapper (New_S, Old_S);
2791 elsif Is_Entity_Name (Nam)
2792 and then Present (Entity (Nam))
2793 and then not Comes_From_Source (Nam)
2794 and then not Is_Overloaded (Nam)
2796 Old_S := Entity (Nam);
2798 -- The subprogram renaming declaration may become Ghost if it
2799 -- renames a Ghost entity.
2801 Mark_Ghost_Renaming (N, Old_S);
2803 New_S := Analyze_Subprogram_Specification (Spec);
2807 if Ekind (Old_S) = E_Operator then
2811 if Box_Present (Inst_Node) then
2812 Old_S := Find_Renamed_Entity (N, Name (N), New_S, Is_Actual);
2814 -- If there is an immediately visible homonym of the operator
2815 -- and the declaration has a default, this is worth a warning
2816 -- because the user probably did not intend to get the pre-
2817 -- defined operator, visible in the generic declaration. To
2818 -- find if there is an intended candidate, analyze the renaming
2819 -- again in the current context.
2821 elsif Scope (Old_S) = Standard_Standard
2822 and then Present (Default_Name (Inst_Node))
2825 Decl : constant Node_Id := New_Copy_Tree (N);
2829 Set_Entity (Name (Decl), Empty);
2830 Analyze (Name (Decl));
2832 Find_Renamed_Entity (Decl, Name (Decl), New_S, True);
2835 and then In_Open_Scopes (Scope (Hidden))
2836 and then Is_Immediately_Visible (Hidden)
2837 and then Comes_From_Source (Hidden)
2838 and then Hidden /= Old_S
2840 Error_Msg_Sloc := Sloc (Hidden);
2842 ("default subprogram is resolved in the generic "
2843 & "declaration (RM 12.6(17))??", N);
2844 Error_Msg_NE ("\and will not use & #??", N, Hidden);
2853 -- The subprogram renaming declaration may become Ghost if it
2854 -- renames a Ghost entity.
2856 if Is_Entity_Name (Nam) then
2857 Mark_Ghost_Renaming (N, Entity (Nam));
2860 New_S := Analyze_Subprogram_Specification (Spec);
2864 -- Renamed entity must be analyzed first, to avoid being hidden by
2865 -- new name (which might be the same in a generic instance).
2869 -- The subprogram renaming declaration may become Ghost if it renames
2872 if Is_Entity_Name (Nam) then
2873 Mark_Ghost_Renaming (N, Entity (Nam));
2876 -- The renaming defines a new overloaded entity, which is analyzed
2877 -- like a subprogram declaration.
2879 New_S := Analyze_Subprogram_Specification (Spec);
2882 if Current_Scope /= Standard_Standard then
2883 Set_Is_Pure (New_S, Is_Pure (Current_Scope));
2886 -- Set SPARK mode from current context
2888 Set_SPARK_Pragma (New_S, SPARK_Mode_Pragma);
2889 Set_SPARK_Pragma_Inherited (New_S);
2891 Rename_Spec := Find_Corresponding_Spec (N);
2893 -- Case of Renaming_As_Body
2895 if Present (Rename_Spec) then
2897 -- Renaming declaration is the completion of the declaration of
2898 -- Rename_Spec. We build an actual body for it at the freezing point.
2900 Set_Corresponding_Spec (N, Rename_Spec);
2902 -- Deal with special case of stream functions of abstract types
2905 if Nkind (Unit_Declaration_Node (Rename_Spec)) =
2906 N_Abstract_Subprogram_Declaration
2908 -- Input stream functions are abstract if the object type is
2909 -- abstract. Similarly, all default stream functions for an
2910 -- interface type are abstract. However, these subprograms may
2911 -- receive explicit declarations in representation clauses, making
2912 -- the attribute subprograms usable as defaults in subsequent
2914 -- In this case we rewrite the declaration to make the subprogram
2915 -- non-abstract. We remove the previous declaration, and insert
2916 -- the new one at the point of the renaming, to prevent premature
2917 -- access to unfrozen types. The new declaration reuses the
2918 -- specification of the previous one, and must not be analyzed.
2921 (Is_Primitive (Entity (Nam))
2923 Is_Abstract_Type (Find_Dispatching_Type (Entity (Nam))));
2925 Old_Decl : constant Node_Id :=
2926 Unit_Declaration_Node (Rename_Spec);
2927 New_Decl : constant Node_Id :=
2928 Make_Subprogram_Declaration (Sloc (N),
2930 Relocate_Node (Specification (Old_Decl)));
2933 Insert_After (N, New_Decl);
2934 Set_Is_Abstract_Subprogram (Rename_Spec, False);
2935 Set_Analyzed (New_Decl);
2939 Set_Corresponding_Body (Unit_Declaration_Node (Rename_Spec), New_S);
2941 if Ada_Version = Ada_83 and then Comes_From_Source (N) then
2942 Error_Msg_N ("(Ada 83) renaming cannot serve as a body", N);
2945 Set_Convention (New_S, Convention (Rename_Spec));
2946 Check_Fully_Conformant (New_S, Rename_Spec);
2947 Set_Public_Status (New_S);
2949 -- The specification does not introduce new formals, but only
2950 -- repeats the formals of the original subprogram declaration.
2951 -- For cross-reference purposes, and for refactoring tools, we
2952 -- treat the formals of the renaming declaration as body formals.
2954 Reference_Body_Formals (Rename_Spec, New_S);
2956 -- Indicate that the entity in the declaration functions like the
2957 -- corresponding body, and is not a new entity. The body will be
2958 -- constructed later at the freeze point, so indicate that the
2959 -- completion has not been seen yet.
2961 Set_Ekind (New_S, E_Subprogram_Body);
2962 New_S := Rename_Spec;
2963 Set_Has_Completion (Rename_Spec, False);
2965 -- Ada 2005: check overriding indicator
2967 if Present (Overridden_Operation (Rename_Spec)) then
2968 if Must_Not_Override (Specification (N)) then
2970 ("subprogram& overrides inherited operation",
2974 and then not Must_Override (Specification (N))
2976 Style.Missing_Overriding (N, Rename_Spec);
2979 elsif Must_Override (Specification (N)) then
2980 Error_Msg_NE ("subprogram& is not overriding", N, Rename_Spec);
2983 -- Normal subprogram renaming (not renaming as body)
2986 Generate_Definition (New_S);
2987 New_Overloaded_Entity (New_S);
2989 if Is_Entity_Name (Nam)
2990 and then Is_Intrinsic_Subprogram (Entity (Nam))
2994 Check_Delayed_Subprogram (New_S);
2998 -- There is no need for elaboration checks on the new entity, which may
2999 -- be called before the next freezing point where the body will appear.
3000 -- Elaboration checks refer to the real entity, not the one created by
3001 -- the renaming declaration.
3003 Set_Kill_Elaboration_Checks (New_S, True);
3005 -- If we had a previous error, indicate a completely is present to stop
3006 -- junk cascaded messages, but don't take any further action.
3008 if Etype (Nam) = Any_Type then
3009 Set_Has_Completion (New_S);
3012 -- Case where name has the form of a selected component
3014 elsif Nkind (Nam) = N_Selected_Component then
3016 -- A name which has the form A.B can designate an entry of task A, a
3017 -- protected operation of protected object A, or finally a primitive
3018 -- operation of object A. In the later case, A is an object of some
3019 -- tagged type, or an access type that denotes one such. To further
3020 -- distinguish these cases, note that the scope of a task entry or
3021 -- protected operation is type of the prefix.
3023 -- The prefix could be an overloaded function call that returns both
3024 -- kinds of operations. This overloading pathology is left to the
3025 -- dedicated reader ???
3028 T : constant Entity_Id := Etype (Prefix (Nam));
3036 and then Is_Tagged_Type (Designated_Type (T))))
3037 and then Scope (Entity (Selector_Name (Nam))) /= T
3039 Analyze_Renamed_Primitive_Operation
3040 (N, New_S, Present (Rename_Spec));
3044 -- Renamed entity is an entry or protected operation. For those
3045 -- cases an explicit body is built (at the point of freezing of
3046 -- this entity) that contains a call to the renamed entity.
3048 -- This is not allowed for renaming as body if the renamed
3049 -- spec is already frozen (see RM 8.5.4(5) for details).
3051 if Present (Rename_Spec) and then Is_Frozen (Rename_Spec) then
3053 ("renaming-as-body cannot rename entry as subprogram", N);
3055 ("\since & is already frozen (RM 8.5.4(5))",
3058 Analyze_Renamed_Entry (N, New_S, Present (Rename_Spec));
3065 -- Case where name is an explicit dereference X.all
3067 elsif Nkind (Nam) = N_Explicit_Dereference then
3069 -- Renamed entity is designated by access_to_subprogram expression.
3070 -- Must build body to encapsulate call, as in the entry case.
3072 Analyze_Renamed_Dereference (N, New_S, Present (Rename_Spec));
3075 -- Indexed component
3077 elsif Nkind (Nam) = N_Indexed_Component then
3078 Analyze_Renamed_Family_Member (N, New_S, Present (Rename_Spec));
3081 -- Character literal
3083 elsif Nkind (Nam) = N_Character_Literal then
3084 Analyze_Renamed_Character (N, New_S, Present (Rename_Spec));
3087 -- Only remaining case is where we have a non-entity name, or a renaming
3088 -- of some other non-overloadable entity.
3090 elsif not Is_Entity_Name (Nam)
3091 or else not Is_Overloadable (Entity (Nam))
3093 -- Do not mention the renaming if it comes from an instance
3095 if not Is_Actual then
3096 Error_Msg_N ("expect valid subprogram name in renaming", N);
3098 Error_Msg_NE ("no visible subprogram for formal&", N, Nam);
3104 -- Find the renamed entity that matches the given specification. Disable
3105 -- Ada_83 because there is no requirement of full conformance between
3106 -- renamed entity and new entity, even though the same circuit is used.
3108 -- This is a bit of an odd case, which introduces a really irregular use
3109 -- of Ada_Version[_Explicit]. Would be nice to find cleaner way to do
3112 Ada_Version := Ada_Version_Type'Max (Ada_Version, Ada_95);
3113 Ada_Version_Pragma := Empty;
3114 Ada_Version_Explicit := Ada_Version;
3117 Old_S := Find_Renamed_Entity (N, Name (N), New_S, Is_Actual);
3119 -- The visible operation may be an inherited abstract operation that
3120 -- was overridden in the private part, in which case a call will
3121 -- dispatch to the overriding operation. Use the overriding one in
3122 -- the renaming declaration, to prevent spurious errors below.
3124 if Is_Overloadable (Old_S)
3125 and then Is_Abstract_Subprogram (Old_S)
3126 and then No (DTC_Entity (Old_S))
3127 and then Present (Alias (Old_S))
3128 and then not Is_Abstract_Subprogram (Alias (Old_S))
3129 and then Present (Overridden_Operation (Alias (Old_S)))
3131 Old_S := Alias (Old_S);
3134 -- When the renamed subprogram is overloaded and used as an actual
3135 -- of a generic, its entity is set to the first available homonym.
3136 -- We must first disambiguate the name, then set the proper entity.
3138 if Is_Actual and then Is_Overloaded (Nam) then
3139 Set_Entity (Nam, Old_S);
3143 -- Most common case: subprogram renames subprogram. No body is generated
3144 -- in this case, so we must indicate the declaration is complete as is.
3145 -- and inherit various attributes of the renamed subprogram.
3147 if No (Rename_Spec) then
3148 Set_Has_Completion (New_S);
3149 Set_Is_Imported (New_S, Is_Imported (Entity (Nam)));
3150 Set_Is_Pure (New_S, Is_Pure (Entity (Nam)));
3151 Set_Is_Preelaborated (New_S, Is_Preelaborated (Entity (Nam)));
3153 -- Ada 2005 (AI-423): Check the consistency of null exclusions
3154 -- between a subprogram and its correct renaming.
3156 -- Note: the Any_Id check is a guard that prevents compiler crashes
3157 -- when performing a null exclusion check between a renaming and a
3158 -- renamed subprogram that has been found to be illegal.
3160 if Ada_Version >= Ada_2005 and then Entity (Nam) /= Any_Id then
3161 Check_Null_Exclusion
3163 Sub => Entity (Nam));
3166 -- Enforce the Ada 2005 rule that the renamed entity cannot require
3167 -- overriding. The flag Requires_Overriding is set very selectively
3168 -- and misses some other illegal cases. The additional conditions
3169 -- checked below are sufficient but not necessary ???
3171 -- The rule does not apply to the renaming generated for an actual
3172 -- subprogram in an instance.
3177 -- Guard against previous errors, and omit renamings of predefined
3180 elsif not Ekind_In (Old_S, E_Function, E_Procedure) then
3183 elsif Requires_Overriding (Old_S)
3185 (Is_Abstract_Subprogram (Old_S)
3186 and then Present (Find_Dispatching_Type (Old_S))
3188 not Is_Abstract_Type (Find_Dispatching_Type (Old_S)))
3191 ("renamed entity cannot be subprogram that requires overriding "
3192 & "(RM 8.5.4 (5.1))", N);
3196 if Old_S /= Any_Id then
3197 if Is_Actual and then From_Default (N) then
3199 -- This is an implicit reference to the default actual
3201 Generate_Reference (Old_S, Nam, Typ => 'i', Force => True);
3204 Generate_Reference (Old_S, Nam);
3207 Check_Internal_Protected_Use (N, Old_S);
3209 -- For a renaming-as-body, require subtype conformance, but if the
3210 -- declaration being completed has not been frozen, then inherit the
3211 -- convention of the renamed subprogram prior to checking conformance
3212 -- (unless the renaming has an explicit convention established; the
3213 -- rule stated in the RM doesn't seem to address this ???).
3215 if Present (Rename_Spec) then
3216 Generate_Reference (Rename_Spec, Defining_Entity (Spec), 'b');
3217 Style.Check_Identifier (Defining_Entity (Spec), Rename_Spec);
3219 if not Is_Frozen (Rename_Spec) then
3220 if not Has_Convention_Pragma (Rename_Spec) then
3221 Set_Convention (New_S, Convention (Old_S));
3224 if Ekind (Old_S) /= E_Operator then
3225 Check_Mode_Conformant (New_S, Old_S, Spec);
3228 if Original_Subprogram (Old_S) = Rename_Spec then
3229 Error_Msg_N ("unfrozen subprogram cannot rename itself ", N);
3232 Check_Subtype_Conformant (New_S, Old_S, Spec);
3235 Check_Frozen_Renaming (N, Rename_Spec);
3237 -- Check explicitly that renamed entity is not intrinsic, because
3238 -- in a generic the renamed body is not built. In this case,
3239 -- the renaming_as_body is a completion.
3241 if Inside_A_Generic then
3242 if Is_Frozen (Rename_Spec)
3243 and then Is_Intrinsic_Subprogram (Old_S)
3246 ("subprogram in renaming_as_body cannot be intrinsic",
3250 Set_Has_Completion (Rename_Spec);
3253 elsif Ekind (Old_S) /= E_Operator then
3255 -- If this a defaulted subprogram for a class-wide actual there is
3256 -- no check for mode conformance, given that the signatures don't
3257 -- match (the source mentions T but the actual mentions T'Class).
3261 elsif not Is_Actual or else No (Enclosing_Instance) then
3262 Check_Mode_Conformant (New_S, Old_S);
3265 if Is_Actual and then Error_Posted (New_S) then
3266 Error_Msg_NE ("invalid actual subprogram: & #!", N, Old_S);
3270 if No (Rename_Spec) then
3272 -- The parameter profile of the new entity is that of the renamed
3273 -- entity: the subtypes given in the specification are irrelevant.
3275 Inherit_Renamed_Profile (New_S, Old_S);
3277 -- A call to the subprogram is transformed into a call to the
3278 -- renamed entity. This is transitive if the renamed entity is
3279 -- itself a renaming.
3281 if Present (Alias (Old_S)) then
3282 Set_Alias (New_S, Alias (Old_S));
3284 Set_Alias (New_S, Old_S);
3287 -- Note that we do not set Is_Intrinsic_Subprogram if we have a
3288 -- renaming as body, since the entity in this case is not an
3289 -- intrinsic (it calls an intrinsic, but we have a real body for
3290 -- this call, and it is in this body that the required intrinsic
3291 -- processing will take place).
3293 -- Also, if this is a renaming of inequality, the renamed operator
3294 -- is intrinsic, but what matters is the corresponding equality
3295 -- operator, which may be user-defined.
3297 Set_Is_Intrinsic_Subprogram
3299 Is_Intrinsic_Subprogram (Old_S)
3301 (Chars (Old_S) /= Name_Op_Ne
3302 or else Ekind (Old_S) = E_Operator
3303 or else Is_Intrinsic_Subprogram
3304 (Corresponding_Equality (Old_S))));
3306 if Ekind (Alias (New_S)) = E_Operator then
3307 Set_Has_Delayed_Freeze (New_S, False);
3310 -- If the renaming corresponds to an association for an abstract
3311 -- formal subprogram, then various attributes must be set to
3312 -- indicate that the renaming is an abstract dispatching operation
3313 -- with a controlling type.
3315 if Is_Actual and then Is_Abstract_Subprogram (Formal_Spec) then
3317 -- Mark the renaming as abstract here, so Find_Dispatching_Type
3318 -- see it as corresponding to a generic association for a
3319 -- formal abstract subprogram
3321 Set_Is_Abstract_Subprogram (New_S);
3324 New_S_Ctrl_Type : constant Entity_Id :=
3325 Find_Dispatching_Type (New_S);
3326 Old_S_Ctrl_Type : constant Entity_Id :=
3327 Find_Dispatching_Type (Old_S);
3331 -- The actual must match the (instance of the) formal,
3332 -- and must be a controlling type.
3334 if Old_S_Ctrl_Type /= New_S_Ctrl_Type
3335 or else No (New_S_Ctrl_Type)
3338 ("actual must be dispatching subprogram for type&",
3339 Nam, New_S_Ctrl_Type);
3342 Set_Is_Dispatching_Operation (New_S);
3343 Check_Controlling_Formals (New_S_Ctrl_Type, New_S);
3345 -- If the actual in the formal subprogram is itself a
3346 -- formal abstract subprogram association, there's no
3347 -- dispatch table component or position to inherit.
3349 if Present (DTC_Entity (Old_S)) then
3350 Set_DTC_Entity (New_S, DTC_Entity (Old_S));
3351 Set_DT_Position_Value (New_S, DT_Position (Old_S));
3361 -- The following is illegal, because F hides whatever other F may
3363 -- function F (...) renames F;
3366 or else (Nkind (Nam) /= N_Expanded_Name
3367 and then Chars (Old_S) = Chars (New_S))
3369 Error_Msg_N ("subprogram cannot rename itself", N);
3371 -- This is illegal even if we use a selector:
3372 -- function F (...) renames Pkg.F;
3373 -- because F is still hidden.
3375 elsif Nkind (Nam) = N_Expanded_Name
3376 and then Entity (Prefix (Nam)) = Current_Scope
3377 and then Chars (Selector_Name (Nam)) = Chars (New_S)
3379 -- This is an error, but we overlook the error and accept the
3380 -- renaming if the special Overriding_Renamings mode is in effect.
3382 if not Overriding_Renamings then
3384 ("implicit operation& is not visible (RM 8.3 (15))",
3389 Set_Convention (New_S, Convention (Old_S));
3391 if Is_Abstract_Subprogram (Old_S) then
3392 if Present (Rename_Spec) then
3394 ("a renaming-as-body cannot rename an abstract subprogram",
3396 Set_Has_Completion (Rename_Spec);
3398 Set_Is_Abstract_Subprogram (New_S);
3402 Check_Library_Unit_Renaming (N, Old_S);
3404 -- Pathological case: procedure renames entry in the scope of its
3405 -- task. Entry is given by simple name, but body must be built for
3406 -- procedure. Of course if called it will deadlock.
3408 if Ekind (Old_S) = E_Entry then
3409 Set_Has_Completion (New_S, False);
3410 Set_Alias (New_S, Empty);
3413 -- Do not freeze the renaming nor the renamed entity when the context
3414 -- is an enclosing generic. Freezing is an expansion activity, and in
3415 -- addition the renamed entity may depend on the generic formals of
3416 -- the enclosing generic.
3418 if Is_Actual and not Inside_A_Generic then
3419 Freeze_Before (N, Old_S);
3420 Freeze_Actual_Profile;
3421 Set_Has_Delayed_Freeze (New_S, False);
3422 Freeze_Before (N, New_S);
3424 -- An abstract subprogram is only allowed as an actual in the case
3425 -- where the formal subprogram is also abstract.
3427 if (Ekind (Old_S) = E_Procedure or else Ekind (Old_S) = E_Function)
3428 and then Is_Abstract_Subprogram (Old_S)
3429 and then not Is_Abstract_Subprogram (Formal_Spec)
3432 ("abstract subprogram not allowed as generic actual", Nam);
3437 -- A common error is to assume that implicit operators for types are
3438 -- defined in Standard, or in the scope of a subtype. In those cases
3439 -- where the renamed entity is given with an expanded name, it is
3440 -- worth mentioning that operators for the type are not declared in
3441 -- the scope given by the prefix.
3443 if Nkind (Nam) = N_Expanded_Name
3444 and then Nkind (Selector_Name (Nam)) = N_Operator_Symbol
3445 and then Scope (Entity (Nam)) = Standard_Standard
3448 T : constant Entity_Id :=
3449 Base_Type (Etype (First_Formal (New_S)));
3451 Error_Msg_Node_2 := Prefix (Nam);
3453 ("operator for type& is not declared in&", Prefix (Nam), T);
3458 ("no visible subprogram matches the specification for&",
3462 if Present (Candidate_Renaming) then
3469 F1 := First_Formal (Candidate_Renaming);
3470 F2 := First_Formal (New_S);
3471 T1 := First_Subtype (Etype (F1));
3472 while Present (F1) and then Present (F2) loop
3477 if Present (F1) and then Present (Default_Value (F1)) then
3478 if Present (Next_Formal (F1)) then
3480 ("\missing specification for & and other formals with "
3481 & "defaults", Spec, F1);
3483 Error_Msg_NE ("\missing specification for &", Spec, F1);
3487 if Nkind (Nam) = N_Operator_Symbol
3488 and then From_Default (N)
3490 Error_Msg_Node_2 := T1;
3492 ("default & on & is not directly visible", Nam, Nam);
3498 -- Ada 2005 AI 404: if the new subprogram is dispatching, verify that
3499 -- controlling access parameters are known non-null for the renamed
3500 -- subprogram. Test also applies to a subprogram instantiation that
3501 -- is dispatching. Test is skipped if some previous error was detected
3502 -- that set Old_S to Any_Id.
3504 if Ada_Version >= Ada_2005
3505 and then Old_S /= Any_Id
3506 and then not Is_Dispatching_Operation (Old_S)
3507 and then Is_Dispatching_Operation (New_S)
3514 Old_F := First_Formal (Old_S);
3515 New_F := First_Formal (New_S);
3516 while Present (Old_F) loop
3517 if Ekind (Etype (Old_F)) = E_Anonymous_Access_Type
3518 and then Is_Controlling_Formal (New_F)
3519 and then not Can_Never_Be_Null (Old_F)
3521 Error_Msg_N ("access parameter is controlling,", New_F);
3523 ("\corresponding parameter of& must be explicitly null "
3524 & "excluding", New_F, Old_S);
3527 Next_Formal (Old_F);
3528 Next_Formal (New_F);
3533 -- A useful warning, suggested by Ada Bug Finder (Ada-Europe 2005)
3534 -- is to warn if an operator is being renamed as a different operator.
3535 -- If the operator is predefined, examine the kind of the entity, not
3536 -- the abbreviated declaration in Standard.
3538 if Comes_From_Source (N)
3539 and then Present (Old_S)
3540 and then (Nkind (Old_S) = N_Defining_Operator_Symbol
3541 or else Ekind (Old_S) = E_Operator)
3542 and then Nkind (New_S) = N_Defining_Operator_Symbol
3543 and then Chars (Old_S) /= Chars (New_S)
3546 ("& is being renamed as a different operator??", N, Old_S);
3549 -- Check for renaming of obsolescent subprogram
3551 Check_Obsolescent_2005_Entity (Entity (Nam), Nam);
3553 -- Another warning or some utility: if the new subprogram as the same
3554 -- name as the old one, the old one is not hidden by an outer homograph,
3555 -- the new one is not a public symbol, and the old one is otherwise
3556 -- directly visible, the renaming is superfluous.
3558 if Chars (Old_S) = Chars (New_S)
3559 and then Comes_From_Source (N)
3560 and then Scope (Old_S) /= Standard_Standard
3561 and then Warn_On_Redundant_Constructs
3562 and then (Is_Immediately_Visible (Old_S)
3563 or else Is_Potentially_Use_Visible (Old_S))
3564 and then Is_Overloadable (Current_Scope)
3565 and then Chars (Current_Scope) /= Chars (Old_S)
3568 ("redundant renaming, entity is directly visible?r?", Name (N));
3571 -- Implementation-defined aspect specifications can appear in a renaming
3572 -- declaration, but not language-defined ones. The call to procedure
3573 -- Analyze_Aspect_Specifications will take care of this error check.
3575 if Has_Aspects (N) then
3576 Analyze_Aspect_Specifications (N, New_S);
3579 Ada_Version := Save_AV;
3580 Ada_Version_Pragma := Save_AVP;
3581 Ada_Version_Explicit := Save_AV_Exp;
3583 -- In GNATprove mode, the renamings of actual subprograms are replaced
3584 -- with wrapper functions that make it easier to propagate axioms to the
3585 -- points of call within an instance. Wrappers are generated if formal
3586 -- subprogram is subject to axiomatization.
3588 -- The types in the wrapper profiles are obtained from (instances of)
3589 -- the types of the formal subprogram.
3592 and then GNATprove_Mode
3593 and then Present (Containing_Package_With_Ext_Axioms (Formal_Spec))
3594 and then not Inside_A_Generic
3596 if Ekind (Old_S) = E_Function then
3597 Rewrite (N, Build_Function_Wrapper (Formal_Spec, Old_S));
3600 elsif Ekind (Old_S) = E_Operator then
3601 Rewrite (N, Build_Operator_Wrapper (Formal_Spec, Old_S));
3605 end Analyze_Subprogram_Renaming;
3607 -------------------------
3608 -- Analyze_Use_Package --
3609 -------------------------
3611 -- Resolve the package names in the use clause, and make all the visible
3612 -- entities defined in the package potentially use-visible. If the package
3613 -- is already in use from a previous use clause, its visible entities are
3614 -- already use-visible. In that case, mark the occurrence as a redundant
3615 -- use. If the package is an open scope, i.e. if the use clause occurs
3616 -- within the package itself, ignore it.
3618 procedure Analyze_Use_Package (N : Node_Id) is
3619 Ghost_Id : Entity_Id := Empty;
3620 Living_Id : Entity_Id := Empty;
3622 Pack_Name : Node_Id;
3625 Check_SPARK_05_Restriction ("use clause is not allowed", N);
3627 Set_Hidden_By_Use_Clause (N, No_Elist);
3629 -- Use clause not allowed in a spec of a predefined package declaration
3630 -- except that packages whose file name starts a-n are OK (these are
3631 -- children of Ada.Numerics, which are never loaded by Rtsfind).
3633 if Is_Predefined_File_Name (Unit_File_Name (Current_Sem_Unit))
3634 and then Get_Name_String
3635 (Unit_File_Name (Current_Sem_Unit)) (1 .. 3) /= "a-n"
3636 and then Nkind (Unit (Cunit (Current_Sem_Unit))) =
3637 N_Package_Declaration
3639 Error_Msg_N ("use clause not allowed in predefined spec", N);
3642 -- Chain clause to list of use clauses in current scope
3644 if Nkind (Parent (N)) /= N_Compilation_Unit then
3645 Chain_Use_Clause (N);
3648 -- Loop through package names to identify referenced packages
3650 Pack_Name := First (Names (N));
3651 while Present (Pack_Name) loop
3652 Analyze (Pack_Name);
3654 if Nkind (Parent (N)) = N_Compilation_Unit
3655 and then Nkind (Pack_Name) = N_Expanded_Name
3661 Pref := Prefix (Pack_Name);
3662 while Nkind (Pref) = N_Expanded_Name loop
3663 Pref := Prefix (Pref);
3666 if Entity (Pref) = Standard_Standard then
3668 ("predefined package Standard cannot appear in a context "
3677 -- Loop through package names to mark all entities as potentially use
3680 Pack_Name := First (Names (N));
3681 while Present (Pack_Name) loop
3682 if Is_Entity_Name (Pack_Name) then
3683 Pack := Entity (Pack_Name);
3685 if Ekind (Pack) /= E_Package and then Etype (Pack) /= Any_Type then
3686 if Ekind (Pack) = E_Generic_Package then
3687 Error_Msg_N -- CODEFIX
3688 ("a generic package is not allowed in a use clause",
3691 elsif Ekind_In (Pack, E_Generic_Function, E_Generic_Package)
3693 Error_Msg_N -- CODEFIX
3694 ("a generic subprogram is not allowed in a use clause",
3697 elsif Ekind_In (Pack, E_Function, E_Procedure, E_Operator) then
3698 Error_Msg_N -- CODEFIX
3699 ("a subprogram is not allowed in a use clause",
3703 Error_Msg_N ("& is not allowed in a use clause", Pack_Name);
3707 if Nkind (Parent (N)) = N_Compilation_Unit then
3708 Check_In_Previous_With_Clause (N, Pack_Name);
3711 if Applicable_Use (Pack_Name) then
3712 Use_One_Package (Pack, N);
3715 -- Capture the first Ghost package and the first living package
3717 if Is_Entity_Name (Pack_Name) then
3718 Pack := Entity (Pack_Name);
3720 if Is_Ghost_Entity (Pack) then
3721 if No (Ghost_Id) then
3725 elsif No (Living_Id) then
3731 -- Report error because name denotes something other than a package
3734 Error_Msg_N ("& is not a package", Pack_Name);
3740 -- Detect a mixture of Ghost packages and living packages within the
3741 -- same use package clause. Ideally one would split a use package clause
3742 -- with multiple names into multiple use package clauses with a single
3743 -- name, however clients of the front end would have to adapt to this
3746 if Present (Ghost_Id) and then Present (Living_Id) then
3748 ("use clause cannot mention ghost and non-ghost ghost units", N);
3750 Error_Msg_Sloc := Sloc (Ghost_Id);
3751 Error_Msg_NE ("\& # declared as ghost", N, Ghost_Id);
3753 Error_Msg_Sloc := Sloc (Living_Id);
3754 Error_Msg_NE ("\& # declared as non-ghost", N, Living_Id);
3757 Mark_Ghost_Clause (N);
3758 end Analyze_Use_Package;
3760 ----------------------
3761 -- Analyze_Use_Type --
3762 ----------------------
3764 procedure Analyze_Use_Type (N : Node_Id) is
3766 Ghost_Id : Entity_Id := Empty;
3768 Living_Id : Entity_Id := Empty;
3771 Set_Hidden_By_Use_Clause (N, No_Elist);
3773 -- Chain clause to list of use clauses in current scope
3775 if Nkind (Parent (N)) /= N_Compilation_Unit then
3776 Chain_Use_Clause (N);
3779 -- If the Used_Operations list is already initialized, the clause has
3780 -- been analyzed previously, and it is being reinstalled, for example
3781 -- when the clause appears in a package spec and we are compiling the
3782 -- corresponding package body. In that case, make the entities on the
3783 -- existing list use_visible, and mark the corresponding types In_Use.
3785 if Present (Used_Operations (N)) then
3791 Mark := First (Subtype_Marks (N));
3792 while Present (Mark) loop
3793 Use_One_Type (Mark, Installed => True);
3797 Elmt := First_Elmt (Used_Operations (N));
3798 while Present (Elmt) loop
3799 Set_Is_Potentially_Use_Visible (Node (Elmt));
3807 -- Otherwise, create new list and attach to it the operations that
3808 -- are made use-visible by the clause.
3810 Set_Used_Operations (N, New_Elmt_List);
3811 Id := First (Subtype_Marks (N));
3812 while Present (Id) loop
3816 if E /= Any_Type then
3819 if Nkind (Parent (N)) = N_Compilation_Unit then
3820 if Nkind (Id) = N_Identifier then
3821 Error_Msg_N ("type is not directly visible", Id);
3823 elsif Is_Child_Unit (Scope (E))
3824 and then Scope (E) /= System_Aux_Id
3826 Check_In_Previous_With_Clause (N, Prefix (Id));
3831 -- If the use_type_clause appears in a compilation unit context,
3832 -- check whether it comes from a unit that may appear in a
3833 -- limited_with_clause, for a better error message.
3835 if Nkind (Parent (N)) = N_Compilation_Unit
3836 and then Nkind (Id) /= N_Identifier
3842 function Mentioned (Nam : Node_Id) return Boolean;
3843 -- Check whether the prefix of expanded name for the type
3844 -- appears in the prefix of some limited_with_clause.
3850 function Mentioned (Nam : Node_Id) return Boolean is
3852 return Nkind (Name (Item)) = N_Selected_Component
3853 and then Chars (Prefix (Name (Item))) = Chars (Nam);
3857 Pref := Prefix (Id);
3858 Item := First (Context_Items (Parent (N)));
3859 while Present (Item) and then Item /= N loop
3860 if Nkind (Item) = N_With_Clause
3861 and then Limited_Present (Item)
3862 and then Mentioned (Pref)
3865 (Get_Msg_Id, "premature usage of incomplete type");
3874 -- Capture the first Ghost type and the first living type
3876 if Is_Ghost_Entity (E) then
3877 if No (Ghost_Id) then
3881 elsif No (Living_Id) then
3888 -- Detect a mixture of Ghost types and living types within the same use
3889 -- type clause. Ideally one would split a use type clause with multiple
3890 -- marks into multiple use type clauses with a single mark, however
3891 -- clients of the front end will have to adapt to this change.
3893 if Present (Ghost_Id) and then Present (Living_Id) then
3895 ("use clause cannot mention ghost and non-ghost ghost types", N);
3897 Error_Msg_Sloc := Sloc (Ghost_Id);
3898 Error_Msg_NE ("\& # declared as ghost", N, Ghost_Id);
3900 Error_Msg_Sloc := Sloc (Living_Id);
3901 Error_Msg_NE ("\& # declared as non-ghost", N, Living_Id);
3904 Mark_Ghost_Clause (N);
3905 end Analyze_Use_Type;
3907 --------------------
3908 -- Applicable_Use --
3909 --------------------
3911 function Applicable_Use (Pack_Name : Node_Id) return Boolean is
3912 Pack : constant Entity_Id := Entity (Pack_Name);
3915 if In_Open_Scopes (Pack) then
3916 if Warn_On_Redundant_Constructs and then Pack = Current_Scope then
3917 Error_Msg_NE -- CODEFIX
3918 ("& is already use-visible within itself?r?", Pack_Name, Pack);
3923 elsif In_Use (Pack) then
3924 Note_Redundant_Use (Pack_Name);
3927 elsif Present (Renamed_Object (Pack))
3928 and then In_Use (Renamed_Object (Pack))
3930 Note_Redundant_Use (Pack_Name);
3938 ------------------------
3939 -- Attribute_Renaming --
3940 ------------------------
3942 procedure Attribute_Renaming (N : Node_Id) is
3943 Loc : constant Source_Ptr := Sloc (N);
3944 Nam : constant Node_Id := Name (N);
3945 Spec : constant Node_Id := Specification (N);
3946 New_S : constant Entity_Id := Defining_Unit_Name (Spec);
3947 Aname : constant Name_Id := Attribute_Name (Nam);
3949 Form_Num : Nat := 0;
3950 Expr_List : List_Id := No_List;
3952 Attr_Node : Node_Id;
3953 Body_Node : Node_Id;
3954 Param_Spec : Node_Id;
3957 Generate_Definition (New_S);
3959 -- This procedure is called in the context of subprogram renaming, and
3960 -- thus the attribute must be one that is a subprogram. All of those
3961 -- have at least one formal parameter, with the exceptions of the GNAT
3962 -- attribute 'Img, which GNAT treats as renameable.
3964 if not Is_Non_Empty_List (Parameter_Specifications (Spec)) then
3965 if Aname /= Name_Img then
3967 ("subprogram renaming an attribute must have formals", N);
3972 Param_Spec := First (Parameter_Specifications (Spec));
3973 while Present (Param_Spec) loop
3974 Form_Num := Form_Num + 1;
3976 if Nkind (Parameter_Type (Param_Spec)) /= N_Access_Definition then
3977 Find_Type (Parameter_Type (Param_Spec));
3979 -- The profile of the new entity denotes the base type (s) of
3980 -- the types given in the specification. For access parameters
3981 -- there are no subtypes involved.
3983 Rewrite (Parameter_Type (Param_Spec),
3985 (Base_Type (Entity (Parameter_Type (Param_Spec))), Loc));
3988 if No (Expr_List) then
3989 Expr_List := New_List;
3992 Append_To (Expr_List,
3993 Make_Identifier (Loc,
3994 Chars => Chars (Defining_Identifier (Param_Spec))));
3996 -- The expressions in the attribute reference are not freeze
3997 -- points. Neither is the attribute as a whole, see below.
3999 Set_Must_Not_Freeze (Last (Expr_List));
4004 -- Immediate error if too many formals. Other mismatches in number or
4005 -- types of parameters are detected when we analyze the body of the
4006 -- subprogram that we construct.
4008 if Form_Num > 2 then
4009 Error_Msg_N ("too many formals for attribute", N);
4011 -- Error if the attribute reference has expressions that look like
4012 -- formal parameters.
4014 elsif Present (Expressions (Nam)) then
4015 Error_Msg_N ("illegal expressions in attribute reference", Nam);
4018 Nam_In (Aname, Name_Compose, Name_Exponent, Name_Leading_Part,
4019 Name_Pos, Name_Round, Name_Scaling,
4022 if Nkind (N) = N_Subprogram_Renaming_Declaration
4023 and then Present (Corresponding_Formal_Spec (N))
4026 ("generic actual cannot be attribute involving universal type",
4030 ("attribute involving a universal type cannot be renamed",
4035 -- Rewrite attribute node to have a list of expressions corresponding to
4036 -- the subprogram formals. A renaming declaration is not a freeze point,
4037 -- and the analysis of the attribute reference should not freeze the
4038 -- type of the prefix. We use the original node in the renaming so that
4039 -- its source location is preserved, and checks on stream attributes are
4040 -- properly applied.
4042 Attr_Node := Relocate_Node (Nam);
4043 Set_Expressions (Attr_Node, Expr_List);
4045 Set_Must_Not_Freeze (Attr_Node);
4046 Set_Must_Not_Freeze (Prefix (Nam));
4048 -- Case of renaming a function
4050 if Nkind (Spec) = N_Function_Specification then
4051 if Is_Procedure_Attribute_Name (Aname) then
4052 Error_Msg_N ("attribute can only be renamed as procedure", Nam);
4056 Find_Type (Result_Definition (Spec));
4057 Rewrite (Result_Definition (Spec),
4059 (Base_Type (Entity (Result_Definition (Spec))), Loc));
4062 Make_Subprogram_Body (Loc,
4063 Specification => Spec,
4064 Declarations => New_List,
4065 Handled_Statement_Sequence =>
4066 Make_Handled_Sequence_Of_Statements (Loc,
4067 Statements => New_List (
4068 Make_Simple_Return_Statement (Loc,
4069 Expression => Attr_Node))));
4071 -- Case of renaming a procedure
4074 if not Is_Procedure_Attribute_Name (Aname) then
4075 Error_Msg_N ("attribute can only be renamed as function", Nam);
4080 Make_Subprogram_Body (Loc,
4081 Specification => Spec,
4082 Declarations => New_List,
4083 Handled_Statement_Sequence =>
4084 Make_Handled_Sequence_Of_Statements (Loc,
4085 Statements => New_List (Attr_Node)));
4088 -- In case of tagged types we add the body of the generated function to
4089 -- the freezing actions of the type (because in the general case such
4090 -- type is still not frozen). We exclude from this processing generic
4091 -- formal subprograms found in instantiations.
4093 -- We must exclude restricted run-time libraries because
4094 -- entity AST_Handler is defined in package System.Aux_Dec which is not
4095 -- available in those platforms. Note that we cannot use the function
4096 -- Restricted_Profile (instead of Configurable_Run_Time_Mode) because
4097 -- the ZFP run-time library is not defined as a profile, and we do not
4098 -- want to deal with AST_Handler in ZFP mode.
4100 if not Configurable_Run_Time_Mode
4101 and then not Present (Corresponding_Formal_Spec (N))
4102 and then Etype (Nam) /= RTE (RE_AST_Handler)
4105 P : constant Node_Id := Prefix (Nam);
4108 -- The prefix of 'Img is an object that is evaluated for each call
4109 -- of the function that renames it.
4111 if Aname = Name_Img then
4112 Preanalyze_And_Resolve (P);
4114 -- For all other attribute renamings, the prefix is a subtype
4120 -- If the target type is not yet frozen, add the body to the
4121 -- actions to be elaborated at freeze time.
4123 if Is_Tagged_Type (Etype (P))
4124 and then In_Open_Scopes (Scope (Etype (P)))
4126 Ensure_Freeze_Node (Etype (P));
4127 Append_Freeze_Action (Etype (P), Body_Node);
4129 Rewrite (N, Body_Node);
4131 Set_Etype (New_S, Base_Type (Etype (New_S)));
4135 -- Generic formal subprograms or AST_Handler renaming
4138 Rewrite (N, Body_Node);
4140 Set_Etype (New_S, Base_Type (Etype (New_S)));
4143 if Is_Compilation_Unit (New_S) then
4145 ("a library unit can only rename another library unit", N);
4148 -- We suppress elaboration warnings for the resulting entity, since
4149 -- clearly they are not needed, and more particularly, in the case
4150 -- of a generic formal subprogram, the resulting entity can appear
4151 -- after the instantiation itself, and thus look like a bogus case
4152 -- of access before elaboration.
4154 Set_Suppress_Elaboration_Warnings (New_S);
4156 end Attribute_Renaming;
4158 ----------------------
4159 -- Chain_Use_Clause --
4160 ----------------------
4162 procedure Chain_Use_Clause (N : Node_Id) is
4164 Level : Int := Scope_Stack.Last;
4167 if not Is_Compilation_Unit (Current_Scope)
4168 or else not Is_Child_Unit (Current_Scope)
4170 null; -- Common case
4172 elsif Defining_Entity (Parent (N)) = Current_Scope then
4173 null; -- Common case for compilation unit
4176 -- If declaration appears in some other scope, it must be in some
4177 -- parent unit when compiling a child.
4179 Pack := Defining_Entity (Parent (N));
4180 if not In_Open_Scopes (Pack) then
4181 null; -- default as well
4183 -- If the use clause appears in an ancestor and we are in the
4184 -- private part of the immediate parent, the use clauses are
4185 -- already installed.
4187 elsif Pack /= Scope (Current_Scope)
4188 and then In_Private_Part (Scope (Current_Scope))
4193 -- Find entry for parent unit in scope stack
4195 while Scope_Stack.Table (Level).Entity /= Pack loop
4201 Set_Next_Use_Clause (N,
4202 Scope_Stack.Table (Level).First_Use_Clause);
4203 Scope_Stack.Table (Level).First_Use_Clause := N;
4204 end Chain_Use_Clause;
4206 ---------------------------
4207 -- Check_Frozen_Renaming --
4208 ---------------------------
4210 procedure Check_Frozen_Renaming (N : Node_Id; Subp : Entity_Id) is
4215 if Is_Frozen (Subp) and then not Has_Completion (Subp) then
4218 (Parent (Declaration_Node (Subp)), Defining_Entity (N));
4220 if Is_Entity_Name (Name (N)) then
4221 Old_S := Entity (Name (N));
4223 if not Is_Frozen (Old_S)
4224 and then Operating_Mode /= Check_Semantics
4226 Append_Freeze_Action (Old_S, B_Node);
4228 Insert_After (N, B_Node);
4232 if Is_Intrinsic_Subprogram (Old_S) and then not In_Instance then
4234 ("subprogram used in renaming_as_body cannot be intrinsic",
4239 Insert_After (N, B_Node);
4243 end Check_Frozen_Renaming;
4245 -------------------------------
4246 -- Set_Entity_Or_Discriminal --
4247 -------------------------------
4249 procedure Set_Entity_Or_Discriminal (N : Node_Id; E : Entity_Id) is
4253 -- If the entity is not a discriminant, or else expansion is disabled,
4254 -- simply set the entity.
4256 if not In_Spec_Expression
4257 or else Ekind (E) /= E_Discriminant
4258 or else Inside_A_Generic
4260 Set_Entity_With_Checks (N, E);
4262 -- The replacement of a discriminant by the corresponding discriminal
4263 -- is not done for a task discriminant that appears in a default
4264 -- expression of an entry parameter. See Exp_Ch2.Expand_Discriminant
4265 -- for details on their handling.
4267 elsif Is_Concurrent_Type (Scope (E)) then
4270 and then not Nkind_In (P, N_Parameter_Specification,
4271 N_Component_Declaration)
4277 and then Nkind (P) = N_Parameter_Specification
4282 Set_Entity (N, Discriminal (E));
4285 -- Otherwise, this is a discriminant in a context in which
4286 -- it is a reference to the corresponding parameter of the
4287 -- init proc for the enclosing type.
4290 Set_Entity (N, Discriminal (E));
4292 end Set_Entity_Or_Discriminal;
4294 -----------------------------------
4295 -- Check_In_Previous_With_Clause --
4296 -----------------------------------
4298 procedure Check_In_Previous_With_Clause
4302 Pack : constant Entity_Id := Entity (Original_Node (Nam));
4307 Item := First (Context_Items (Parent (N)));
4308 while Present (Item) and then Item /= N loop
4309 if Nkind (Item) = N_With_Clause
4311 -- Protect the frontend against previous critical errors
4313 and then Nkind (Name (Item)) /= N_Selected_Component
4314 and then Entity (Name (Item)) = Pack
4318 -- Find root library unit in with_clause
4320 while Nkind (Par) = N_Expanded_Name loop
4321 Par := Prefix (Par);
4324 if Is_Child_Unit (Entity (Original_Node (Par))) then
4325 Error_Msg_NE ("& is not directly visible", Par, Entity (Par));
4334 -- On exit, package is not mentioned in a previous with_clause.
4335 -- Check if its prefix is.
4337 if Nkind (Nam) = N_Expanded_Name then
4338 Check_In_Previous_With_Clause (N, Prefix (Nam));
4340 elsif Pack /= Any_Id then
4341 Error_Msg_NE ("& is not visible", Nam, Pack);
4343 end Check_In_Previous_With_Clause;
4345 ---------------------------------
4346 -- Check_Library_Unit_Renaming --
4347 ---------------------------------
4349 procedure Check_Library_Unit_Renaming (N : Node_Id; Old_E : Entity_Id) is
4353 if Nkind (Parent (N)) /= N_Compilation_Unit then
4356 -- Check for library unit. Note that we used to check for the scope
4357 -- being Standard here, but that was wrong for Standard itself.
4359 elsif not Is_Compilation_Unit (Old_E)
4360 and then not Is_Child_Unit (Old_E)
4362 Error_Msg_N ("renamed unit must be a library unit", Name (N));
4364 -- Entities defined in Standard (operators and boolean literals) cannot
4365 -- be renamed as library units.
4367 elsif Scope (Old_E) = Standard_Standard
4368 and then Sloc (Old_E) = Standard_Location
4370 Error_Msg_N ("renamed unit must be a library unit", Name (N));
4372 elsif Present (Parent_Spec (N))
4373 and then Nkind (Unit (Parent_Spec (N))) = N_Generic_Package_Declaration
4374 and then not Is_Child_Unit (Old_E)
4377 ("renamed unit must be a child unit of generic parent", Name (N));
4379 elsif Nkind (N) in N_Generic_Renaming_Declaration
4380 and then Nkind (Name (N)) = N_Expanded_Name
4381 and then Is_Generic_Instance (Entity (Prefix (Name (N))))
4382 and then Is_Generic_Unit (Old_E)
4385 ("renamed generic unit must be a library unit", Name (N));
4387 elsif Is_Package_Or_Generic_Package (Old_E) then
4389 -- Inherit categorization flags
4391 New_E := Defining_Entity (N);
4392 Set_Is_Pure (New_E, Is_Pure (Old_E));
4393 Set_Is_Preelaborated (New_E, Is_Preelaborated (Old_E));
4394 Set_Is_Remote_Call_Interface (New_E,
4395 Is_Remote_Call_Interface (Old_E));
4396 Set_Is_Remote_Types (New_E, Is_Remote_Types (Old_E));
4397 Set_Is_Shared_Passive (New_E, Is_Shared_Passive (Old_E));
4399 end Check_Library_Unit_Renaming;
4401 ------------------------
4402 -- Enclosing_Instance --
4403 ------------------------
4405 function Enclosing_Instance return Entity_Id is
4409 if not Is_Generic_Instance (Current_Scope) then
4413 S := Scope (Current_Scope);
4414 while S /= Standard_Standard loop
4415 if Is_Generic_Instance (S) then
4423 end Enclosing_Instance;
4429 procedure End_Scope is
4435 Id := First_Entity (Current_Scope);
4436 while Present (Id) loop
4437 -- An entity in the current scope is not necessarily the first one
4438 -- on its homonym chain. Find its predecessor if any,
4439 -- If it is an internal entity, it will not be in the visibility
4440 -- chain altogether, and there is nothing to unchain.
4442 if Id /= Current_Entity (Id) then
4443 Prev := Current_Entity (Id);
4444 while Present (Prev)
4445 and then Present (Homonym (Prev))
4446 and then Homonym (Prev) /= Id
4448 Prev := Homonym (Prev);
4451 -- Skip to end of loop if Id is not in the visibility chain
4453 if No (Prev) or else Homonym (Prev) /= Id then
4461 Set_Is_Immediately_Visible (Id, False);
4463 Outer := Homonym (Id);
4464 while Present (Outer) and then Scope (Outer) = Current_Scope loop
4465 Outer := Homonym (Outer);
4468 -- Reset homonym link of other entities, but do not modify link
4469 -- between entities in current scope, so that the back-end can have
4470 -- a proper count of local overloadings.
4473 Set_Name_Entity_Id (Chars (Id), Outer);
4475 elsif Scope (Prev) /= Scope (Id) then
4476 Set_Homonym (Prev, Outer);
4483 -- If the scope generated freeze actions, place them before the
4484 -- current declaration and analyze them. Type declarations and
4485 -- the bodies of initialization procedures can generate such nodes.
4486 -- We follow the parent chain until we reach a list node, which is
4487 -- the enclosing list of declarations. If the list appears within
4488 -- a protected definition, move freeze nodes outside the protected
4492 (Scope_Stack.Table (Scope_Stack.Last).Pending_Freeze_Actions)
4496 L : constant List_Id := Scope_Stack.Table
4497 (Scope_Stack.Last).Pending_Freeze_Actions;
4500 if Is_Itype (Current_Scope) then
4501 Decl := Associated_Node_For_Itype (Current_Scope);
4503 Decl := Parent (Current_Scope);
4508 while not (Is_List_Member (Decl))
4509 or else Nkind_In (Parent (Decl), N_Protected_Definition,
4512 Decl := Parent (Decl);
4515 Insert_List_Before_And_Analyze (Decl, L);
4523 ---------------------
4524 -- End_Use_Clauses --
4525 ---------------------
4527 procedure End_Use_Clauses (Clause : Node_Id) is
4531 -- Remove Use_Type clauses first, because they affect the
4532 -- visibility of operators in subsequent used packages.
4535 while Present (U) loop
4536 if Nkind (U) = N_Use_Type_Clause then
4540 Next_Use_Clause (U);
4544 while Present (U) loop
4545 if Nkind (U) = N_Use_Package_Clause then
4546 End_Use_Package (U);
4549 Next_Use_Clause (U);
4551 end End_Use_Clauses;
4553 ---------------------
4554 -- End_Use_Package --
4555 ---------------------
4557 procedure End_Use_Package (N : Node_Id) is
4558 Pack_Name : Node_Id;
4563 function Is_Primitive_Operator_In_Use
4565 F : Entity_Id) return Boolean;
4566 -- Check whether Op is a primitive operator of a use-visible type
4568 ----------------------------------
4569 -- Is_Primitive_Operator_In_Use --
4570 ----------------------------------
4572 function Is_Primitive_Operator_In_Use
4574 F : Entity_Id) return Boolean
4576 T : constant Entity_Id := Base_Type (Etype (F));
4578 return In_Use (T) and then Scope (T) = Scope (Op);
4579 end Is_Primitive_Operator_In_Use;
4581 -- Start of processing for End_Use_Package
4584 Pack_Name := First (Names (N));
4585 while Present (Pack_Name) loop
4587 -- Test that Pack_Name actually denotes a package before processing
4589 if Is_Entity_Name (Pack_Name)
4590 and then Ekind (Entity (Pack_Name)) = E_Package
4592 Pack := Entity (Pack_Name);
4594 if In_Open_Scopes (Pack) then
4597 elsif not Redundant_Use (Pack_Name) then
4598 Set_In_Use (Pack, False);
4599 Set_Current_Use_Clause (Pack, Empty);
4601 Id := First_Entity (Pack);
4602 while Present (Id) loop
4604 -- Preserve use-visibility of operators that are primitive
4605 -- operators of a type that is use-visible through an active
4608 if Nkind (Id) = N_Defining_Operator_Symbol
4610 (Is_Primitive_Operator_In_Use (Id, First_Formal (Id))
4612 (Present (Next_Formal (First_Formal (Id)))
4614 Is_Primitive_Operator_In_Use
4615 (Id, Next_Formal (First_Formal (Id)))))
4619 Set_Is_Potentially_Use_Visible (Id, False);
4622 if Is_Private_Type (Id)
4623 and then Present (Full_View (Id))
4625 Set_Is_Potentially_Use_Visible (Full_View (Id), False);
4631 if Present (Renamed_Object (Pack)) then
4632 Set_In_Use (Renamed_Object (Pack), False);
4633 Set_Current_Use_Clause (Renamed_Object (Pack), Empty);
4636 if Chars (Pack) = Name_System
4637 and then Scope (Pack) = Standard_Standard
4638 and then Present_System_Aux
4640 Id := First_Entity (System_Aux_Id);
4641 while Present (Id) loop
4642 Set_Is_Potentially_Use_Visible (Id, False);
4644 if Is_Private_Type (Id)
4645 and then Present (Full_View (Id))
4647 Set_Is_Potentially_Use_Visible (Full_View (Id), False);
4653 Set_In_Use (System_Aux_Id, False);
4657 Set_Redundant_Use (Pack_Name, False);
4664 if Present (Hidden_By_Use_Clause (N)) then
4665 Elmt := First_Elmt (Hidden_By_Use_Clause (N));
4666 while Present (Elmt) loop
4668 E : constant Entity_Id := Node (Elmt);
4671 -- Reset either Use_Visibility or Direct_Visibility, depending
4672 -- on how the entity was hidden by the use clause.
4674 if In_Use (Scope (E))
4675 and then Used_As_Generic_Actual (Scope (E))
4677 Set_Is_Potentially_Use_Visible (Node (Elmt));
4679 Set_Is_Immediately_Visible (Node (Elmt));
4686 Set_Hidden_By_Use_Clause (N, No_Elist);
4688 end End_Use_Package;
4694 procedure End_Use_Type (N : Node_Id) is
4699 -- Start of processing for End_Use_Type
4702 Id := First (Subtype_Marks (N));
4703 while Present (Id) loop
4705 -- A call to Rtsfind may occur while analyzing a use_type clause,
4706 -- in which case the type marks are not resolved yet, and there is
4707 -- nothing to remove.
4709 if not Is_Entity_Name (Id) or else No (Entity (Id)) then
4715 if T = Any_Type or else From_Limited_With (T) then
4718 -- Note that the use_type clause may mention a subtype of the type
4719 -- whose primitive operations have been made visible. Here as
4720 -- elsewhere, it is the base type that matters for visibility.
4722 elsif In_Open_Scopes (Scope (Base_Type (T))) then
4725 elsif not Redundant_Use (Id) then
4726 Set_In_Use (T, False);
4727 Set_In_Use (Base_Type (T), False);
4728 Set_Current_Use_Clause (T, Empty);
4729 Set_Current_Use_Clause (Base_Type (T), Empty);
4736 if Is_Empty_Elmt_List (Used_Operations (N)) then
4740 Elmt := First_Elmt (Used_Operations (N));
4741 while Present (Elmt) loop
4742 Set_Is_Potentially_Use_Visible (Node (Elmt), False);
4748 ----------------------
4749 -- Find_Direct_Name --
4750 ----------------------
4752 procedure Find_Direct_Name (N : Node_Id) is
4757 Inst : Entity_Id := Empty;
4758 -- Enclosing instance, if any
4760 Homonyms : Entity_Id;
4761 -- Saves start of homonym chain
4763 Nvis_Entity : Boolean;
4764 -- Set True to indicate that there is at least one entity on the homonym
4765 -- chain which, while not visible, is visible enough from the user point
4766 -- of view to warrant an error message of "not visible" rather than
4769 Nvis_Is_Private_Subprg : Boolean := False;
4770 -- Ada 2005 (AI-262): Set True to indicate that a form of Beaujolais
4771 -- effect concerning library subprograms has been detected. Used to
4772 -- generate the precise error message.
4774 function From_Actual_Package (E : Entity_Id) return Boolean;
4775 -- Returns true if the entity is an actual for a package that is itself
4776 -- an actual for a formal package of the current instance. Such an
4777 -- entity requires special handling because it may be use-visible but
4778 -- hides directly visible entities defined outside the instance, because
4779 -- the corresponding formal did so in the generic.
4781 function Is_Actual_Parameter return Boolean;
4782 -- This function checks if the node N is an identifier that is an actual
4783 -- parameter of a procedure call. If so it returns True, otherwise it
4784 -- return False. The reason for this check is that at this stage we do
4785 -- not know what procedure is being called if the procedure might be
4786 -- overloaded, so it is premature to go setting referenced flags or
4787 -- making calls to Generate_Reference. We will wait till Resolve_Actuals
4788 -- for that processing
4790 function Known_But_Invisible (E : Entity_Id) return Boolean;
4791 -- This function determines whether a reference to the entity E, which
4792 -- is not visible, can reasonably be considered to be known to the
4793 -- writer of the reference. This is a heuristic test, used only for
4794 -- the purposes of figuring out whether we prefer to complain that an
4795 -- entity is undefined or invisible (and identify the declaration of
4796 -- the invisible entity in the latter case). The point here is that we
4797 -- don't want to complain that something is invisible and then point to
4798 -- something entirely mysterious to the writer.
4800 procedure Nvis_Messages;
4801 -- Called if there are no visible entries for N, but there is at least
4802 -- one non-directly visible, or hidden declaration. This procedure
4803 -- outputs an appropriate set of error messages.
4805 procedure Undefined (Nvis : Boolean);
4806 -- This function is called if the current node has no corresponding
4807 -- visible entity or entities. The value set in Msg indicates whether
4808 -- an error message was generated (multiple error messages for the
4809 -- same variable are generally suppressed, see body for details).
4810 -- Msg is True if an error message was generated, False if not. This
4811 -- value is used by the caller to determine whether or not to output
4812 -- additional messages where appropriate. The parameter is set False
4813 -- to get the message "X is undefined", and True to get the message
4814 -- "X is not visible".
4816 -------------------------
4817 -- From_Actual_Package --
4818 -------------------------
4820 function From_Actual_Package (E : Entity_Id) return Boolean is
4821 Scop : constant Entity_Id := Scope (E);
4822 -- Declared scope of candidate entity
4826 function Declared_In_Actual (Pack : Entity_Id) return Boolean;
4827 -- Recursive function that does the work and examines actuals of
4828 -- actual packages of current instance.
4830 ------------------------
4831 -- Declared_In_Actual --
4832 ------------------------
4834 function Declared_In_Actual (Pack : Entity_Id) return Boolean is
4838 if No (Associated_Formal_Package (Pack)) then
4842 Act := First_Entity (Pack);
4843 while Present (Act) loop
4844 if Renamed_Object (Pack) = Scop then
4847 -- Check for end of list of actuals.
4849 elsif Ekind (Act) = E_Package
4850 and then Renamed_Object (Act) = Pack
4854 elsif Ekind (Act) = E_Package
4855 and then Declared_In_Actual (Act)
4865 end Declared_In_Actual;
4867 -- Start of processing for From_Actual_Package
4870 if not In_Instance then
4874 Inst := Current_Scope;
4875 while Present (Inst)
4876 and then Ekind (Inst) /= E_Package
4877 and then not Is_Generic_Instance (Inst)
4879 Inst := Scope (Inst);
4886 Act := First_Entity (Inst);
4887 while Present (Act) loop
4888 if Ekind (Act) = E_Package
4889 and then Declared_In_Actual (Act)
4899 end From_Actual_Package;
4901 -------------------------
4902 -- Is_Actual_Parameter --
4903 -------------------------
4905 function Is_Actual_Parameter return Boolean is
4908 Nkind (N) = N_Identifier
4910 (Nkind (Parent (N)) = N_Procedure_Call_Statement
4912 (Nkind (Parent (N)) = N_Parameter_Association
4913 and then N = Explicit_Actual_Parameter (Parent (N))
4914 and then Nkind (Parent (Parent (N))) =
4915 N_Procedure_Call_Statement));
4916 end Is_Actual_Parameter;
4918 -------------------------
4919 -- Known_But_Invisible --
4920 -------------------------
4922 function Known_But_Invisible (E : Entity_Id) return Boolean is
4923 Fname : File_Name_Type;
4926 -- Entities in Standard are always considered to be known
4928 if Sloc (E) <= Standard_Location then
4931 -- An entity that does not come from source is always considered
4932 -- to be unknown, since it is an artifact of code expansion.
4934 elsif not Comes_From_Source (E) then
4937 -- In gnat internal mode, we consider all entities known. The
4938 -- historical reason behind this discrepancy is not known??? But the
4939 -- only effect is to modify the error message given, so it is not
4940 -- critical. Since it only affects the exact wording of error
4941 -- messages in illegal programs, we do not mention this as an
4942 -- effect of -gnatg, since it is not a language modification.
4944 elsif GNAT_Mode then
4948 -- Here we have an entity that is not from package Standard, and
4949 -- which comes from Source. See if it comes from an internal file.
4951 Fname := Unit_File_Name (Get_Source_Unit (E));
4953 -- Case of from internal file
4955 if Is_Internal_File_Name (Fname) then
4957 -- Private part entities in internal files are never considered
4958 -- to be known to the writer of normal application code.
4960 if Is_Hidden (E) then
4964 -- Entities from System packages other than System and
4965 -- System.Storage_Elements are not considered to be known.
4966 -- System.Auxxxx files are also considered known to the user.
4968 -- Should refine this at some point to generally distinguish
4969 -- between known and unknown internal files ???
4971 Get_Name_String (Fname);
4976 Name_Buffer (1 .. 2) /= "s-"
4978 Name_Buffer (3 .. 8) = "stoele"
4980 Name_Buffer (3 .. 5) = "aux";
4982 -- If not an internal file, then entity is definitely known, even if
4983 -- it is in a private part (the message generated will note that it
4984 -- is in a private part).
4989 end Known_But_Invisible;
4995 procedure Nvis_Messages is
4996 Comp_Unit : Node_Id;
4998 Found : Boolean := False;
4999 Hidden : Boolean := False;
5003 -- Ada 2005 (AI-262): Generate a precise error concerning the
5004 -- Beaujolais effect that was previously detected
5006 if Nvis_Is_Private_Subprg then
5008 pragma Assert (Nkind (E2) = N_Defining_Identifier
5009 and then Ekind (E2) = E_Function
5010 and then Scope (E2) = Standard_Standard
5011 and then Has_Private_With (E2));
5013 -- Find the sloc corresponding to the private with'ed unit
5015 Comp_Unit := Cunit (Current_Sem_Unit);
5016 Error_Msg_Sloc := No_Location;
5018 Item := First (Context_Items (Comp_Unit));
5019 while Present (Item) loop
5020 if Nkind (Item) = N_With_Clause
5021 and then Private_Present (Item)
5022 and then Entity (Name (Item)) = E2
5024 Error_Msg_Sloc := Sloc (Item);
5031 pragma Assert (Error_Msg_Sloc /= No_Location);
5033 Error_Msg_N ("(Ada 2005): hidden by private with clause #", N);
5037 Undefined (Nvis => True);
5041 -- First loop does hidden declarations
5044 while Present (Ent) loop
5045 if Is_Potentially_Use_Visible (Ent) then
5047 Error_Msg_N -- CODEFIX
5048 ("multiple use clauses cause hiding!", N);
5052 Error_Msg_Sloc := Sloc (Ent);
5053 Error_Msg_N -- CODEFIX
5054 ("hidden declaration#!", N);
5057 Ent := Homonym (Ent);
5060 -- If we found hidden declarations, then that's enough, don't
5061 -- bother looking for non-visible declarations as well.
5067 -- Second loop does non-directly visible declarations
5070 while Present (Ent) loop
5071 if not Is_Potentially_Use_Visible (Ent) then
5073 -- Do not bother the user with unknown entities
5075 if not Known_But_Invisible (Ent) then
5079 Error_Msg_Sloc := Sloc (Ent);
5081 -- Output message noting that there is a non-visible
5082 -- declaration, distinguishing the private part case.
5084 if Is_Hidden (Ent) then
5085 Error_Msg_N ("non-visible (private) declaration#!", N);
5087 -- If the entity is declared in a generic package, it
5088 -- cannot be visible, so there is no point in adding it
5089 -- to the list of candidates if another homograph from a
5090 -- non-generic package has been seen.
5092 elsif Ekind (Scope (Ent)) = E_Generic_Package
5098 Error_Msg_N -- CODEFIX
5099 ("non-visible declaration#!", N);
5101 if Ekind (Scope (Ent)) /= E_Generic_Package then
5105 if Is_Compilation_Unit (Ent)
5107 Nkind (Parent (Parent (N))) = N_Use_Package_Clause
5109 Error_Msg_Qual_Level := 99;
5110 Error_Msg_NE -- CODEFIX
5111 ("\\missing `WITH &;`", N, Ent);
5112 Error_Msg_Qual_Level := 0;
5115 if Ekind (Ent) = E_Discriminant
5116 and then Present (Corresponding_Discriminant (Ent))
5117 and then Scope (Corresponding_Discriminant (Ent)) =
5121 ("inherited discriminant not allowed here" &
5122 " (RM 3.8 (12), 3.8.1 (6))!", N);
5126 -- Set entity and its containing package as referenced. We
5127 -- can't be sure of this, but this seems a better choice
5128 -- to avoid unused entity messages.
5130 if Comes_From_Source (Ent) then
5131 Set_Referenced (Ent);
5132 Set_Referenced (Cunit_Entity (Get_Source_Unit (Ent)));
5137 Ent := Homonym (Ent);
5146 procedure Undefined (Nvis : Boolean) is
5147 Emsg : Error_Msg_Id;
5150 -- We should never find an undefined internal name. If we do, then
5151 -- see if we have previous errors. If so, ignore on the grounds that
5152 -- it is probably a cascaded message (e.g. a block label from a badly
5153 -- formed block). If no previous errors, then we have a real internal
5154 -- error of some kind so raise an exception.
5156 if Is_Internal_Name (Chars (N)) then
5157 if Total_Errors_Detected /= 0 then
5160 raise Program_Error;
5164 -- A very specialized error check, if the undefined variable is
5165 -- a case tag, and the case type is an enumeration type, check
5166 -- for a possible misspelling, and if so, modify the identifier
5168 -- Named aggregate should also be handled similarly ???
5170 if Nkind (N) = N_Identifier
5171 and then Nkind (Parent (N)) = N_Case_Statement_Alternative
5174 Case_Stm : constant Node_Id := Parent (Parent (N));
5175 Case_Typ : constant Entity_Id := Etype (Expression (Case_Stm));
5180 if Is_Enumeration_Type (Case_Typ)
5181 and then not Is_Standard_Character_Type (Case_Typ)
5183 Lit := First_Literal (Case_Typ);
5184 Get_Name_String (Chars (Lit));
5186 if Chars (Lit) /= Chars (N)
5187 and then Is_Bad_Spelling_Of (Chars (N), Chars (Lit))
5189 Error_Msg_Node_2 := Lit;
5190 Error_Msg_N -- CODEFIX
5191 ("& is undefined, assume misspelling of &", N);
5192 Rewrite (N, New_Occurrence_Of (Lit, Sloc (N)));
5196 Lit := Next_Literal (Lit);
5201 -- Normal processing
5203 Set_Entity (N, Any_Id);
5204 Set_Etype (N, Any_Type);
5206 -- We use the table Urefs to keep track of entities for which we
5207 -- have issued errors for undefined references. Multiple errors
5208 -- for a single name are normally suppressed, however we modify
5209 -- the error message to alert the programmer to this effect.
5211 for J in Urefs.First .. Urefs.Last loop
5212 if Chars (N) = Chars (Urefs.Table (J).Node) then
5213 if Urefs.Table (J).Err /= No_Error_Msg
5214 and then Sloc (N) /= Urefs.Table (J).Loc
5216 Error_Msg_Node_1 := Urefs.Table (J).Node;
5218 if Urefs.Table (J).Nvis then
5219 Change_Error_Text (Urefs.Table (J).Err,
5220 "& is not visible (more references follow)");
5222 Change_Error_Text (Urefs.Table (J).Err,
5223 "& is undefined (more references follow)");
5226 Urefs.Table (J).Err := No_Error_Msg;
5229 -- Although we will set Msg False, and thus suppress the
5230 -- message, we also set Error_Posted True, to avoid any
5231 -- cascaded messages resulting from the undefined reference.
5234 Set_Error_Posted (N, True);
5239 -- If entry not found, this is first undefined occurrence
5242 Error_Msg_N ("& is not visible!", N);
5246 Error_Msg_N ("& is undefined!", N);
5249 -- A very bizarre special check, if the undefined identifier
5250 -- is put or put_line, then add a special error message (since
5251 -- this is a very common error for beginners to make).
5253 if Nam_In (Chars (N), Name_Put, Name_Put_Line) then
5254 Error_Msg_N -- CODEFIX
5255 ("\\possible missing `WITH Ada.Text_'I'O; " &
5256 "USE Ada.Text_'I'O`!", N);
5258 -- Another special check if N is the prefix of a selected
5259 -- component which is a known unit, add message complaining
5260 -- about missing with for this unit.
5262 elsif Nkind (Parent (N)) = N_Selected_Component
5263 and then N = Prefix (Parent (N))
5264 and then Is_Known_Unit (Parent (N))
5266 Error_Msg_Node_2 := Selector_Name (Parent (N));
5267 Error_Msg_N -- CODEFIX
5268 ("\\missing `WITH &.&;`", Prefix (Parent (N)));
5271 -- Now check for possible misspellings
5275 Ematch : Entity_Id := Empty;
5277 Last_Name_Id : constant Name_Id :=
5278 Name_Id (Nat (First_Name_Id) +
5279 Name_Entries_Count - 1);
5282 for Nam in First_Name_Id .. Last_Name_Id loop
5283 E := Get_Name_Entity_Id (Nam);
5286 and then (Is_Immediately_Visible (E)
5288 Is_Potentially_Use_Visible (E))
5290 if Is_Bad_Spelling_Of (Chars (N), Nam) then
5297 if Present (Ematch) then
5298 Error_Msg_NE -- CODEFIX
5299 ("\possible misspelling of&", N, Ematch);
5304 -- Make entry in undefined references table unless the full errors
5305 -- switch is set, in which case by refraining from generating the
5306 -- table entry, we guarantee that we get an error message for every
5307 -- undefined reference.
5309 if not All_Errors_Mode then
5320 -- Start of processing for Find_Direct_Name
5323 -- If the entity pointer is already set, this is an internal node, or
5324 -- a node that is analyzed more than once, after a tree modification.
5325 -- In such a case there is no resolution to perform, just set the type.
5327 if Present (Entity (N)) then
5328 if Is_Type (Entity (N)) then
5329 Set_Etype (N, Entity (N));
5333 Entyp : constant Entity_Id := Etype (Entity (N));
5336 -- One special case here. If the Etype field is already set,
5337 -- and references the packed array type corresponding to the
5338 -- etype of the referenced entity, then leave it alone. This
5339 -- happens for trees generated from Exp_Pakd, where expressions
5340 -- can be deliberately "mis-typed" to the packed array type.
5342 if Is_Array_Type (Entyp)
5343 and then Is_Packed (Entyp)
5344 and then Present (Etype (N))
5345 and then Etype (N) = Packed_Array_Impl_Type (Entyp)
5349 -- If not that special case, then just reset the Etype
5352 Set_Etype (N, Etype (Entity (N)));
5360 -- Here if Entity pointer was not set, we need full visibility analysis
5361 -- First we generate debugging output if the debug E flag is set.
5363 if Debug_Flag_E then
5364 Write_Str ("Looking for ");
5365 Write_Name (Chars (N));
5369 Homonyms := Current_Entity (N);
5370 Nvis_Entity := False;
5373 while Present (E) loop
5375 -- If entity is immediately visible or potentially use visible, then
5376 -- process the entity and we are done.
5378 if Is_Immediately_Visible (E) then
5379 goto Immediately_Visible_Entity;
5381 elsif Is_Potentially_Use_Visible (E) then
5382 goto Potentially_Use_Visible_Entity;
5384 -- Note if a known but invisible entity encountered
5386 elsif Known_But_Invisible (E) then
5387 Nvis_Entity := True;
5390 -- Move to next entity in chain and continue search
5395 -- If no entries on homonym chain that were potentially visible,
5396 -- and no entities reasonably considered as non-visible, then
5397 -- we have a plain undefined reference, with no additional
5398 -- explanation required.
5400 if not Nvis_Entity then
5401 Undefined (Nvis => False);
5403 -- Otherwise there is at least one entry on the homonym chain that
5404 -- is reasonably considered as being known and non-visible.
5412 -- Processing for a potentially use visible entry found. We must search
5413 -- the rest of the homonym chain for two reasons. First, if there is a
5414 -- directly visible entry, then none of the potentially use-visible
5415 -- entities are directly visible (RM 8.4(10)). Second, we need to check
5416 -- for the case of multiple potentially use-visible entries hiding one
5417 -- another and as a result being non-directly visible (RM 8.4(11)).
5419 <<Potentially_Use_Visible_Entity>> declare
5420 Only_One_Visible : Boolean := True;
5421 All_Overloadable : Boolean := Is_Overloadable (E);
5425 while Present (E2) loop
5426 if Is_Immediately_Visible (E2) then
5428 -- If the use-visible entity comes from the actual for a
5429 -- formal package, it hides a directly visible entity from
5430 -- outside the instance.
5432 if From_Actual_Package (E)
5433 and then Scope_Depth (E2) < Scope_Depth (Inst)
5438 goto Immediately_Visible_Entity;
5441 elsif Is_Potentially_Use_Visible (E2) then
5442 Only_One_Visible := False;
5443 All_Overloadable := All_Overloadable and Is_Overloadable (E2);
5445 -- Ada 2005 (AI-262): Protect against a form of Beaujolais effect
5446 -- that can occur in private_with clauses. Example:
5449 -- private with B; package A is
5450 -- package C is function B return Integer;
5452 -- V1 : Integer := B;
5453 -- private function B return Integer;
5454 -- V2 : Integer := B;
5457 -- V1 resolves to A.B, but V2 resolves to library unit B
5459 elsif Ekind (E2) = E_Function
5460 and then Scope (E2) = Standard_Standard
5461 and then Has_Private_With (E2)
5463 Only_One_Visible := False;
5464 All_Overloadable := False;
5465 Nvis_Is_Private_Subprg := True;
5472 -- On falling through this loop, we have checked that there are no
5473 -- immediately visible entities. Only_One_Visible is set if exactly
5474 -- one potentially use visible entity exists. All_Overloadable is
5475 -- set if all the potentially use visible entities are overloadable.
5476 -- The condition for legality is that either there is one potentially
5477 -- use visible entity, or if there is more than one, then all of them
5478 -- are overloadable.
5480 if Only_One_Visible or All_Overloadable then
5483 -- If there is more than one potentially use-visible entity and at
5484 -- least one of them non-overloadable, we have an error (RM 8.4(11)).
5485 -- Note that E points to the first such entity on the homonym list.
5486 -- Special case: if one of the entities is declared in an actual
5487 -- package, it was visible in the generic, and takes precedence over
5488 -- other entities that are potentially use-visible. Same if it is
5489 -- declared in a local instantiation of the current instance.
5494 -- Find current instance
5496 Inst := Current_Scope;
5497 while Present (Inst) and then Inst /= Standard_Standard loop
5498 if Is_Generic_Instance (Inst) then
5502 Inst := Scope (Inst);
5506 while Present (E2) loop
5507 if From_Actual_Package (E2)
5509 (Is_Generic_Instance (Scope (E2))
5510 and then Scope_Depth (Scope (E2)) > Scope_Depth (Inst))
5523 Is_Predefined_File_Name (Unit_File_Name (Current_Sem_Unit))
5525 -- A use-clause in the body of a system file creates conflict
5526 -- with some entity in a user scope, while rtsfind is active.
5527 -- Keep only the entity coming from another predefined unit.
5530 while Present (E2) loop
5531 if Is_Predefined_File_Name
5532 (Unit_File_Name (Get_Source_Unit (Sloc (E2))))
5541 -- Entity must exist because predefined unit is correct
5543 raise Program_Error;
5552 -- Come here with E set to the first immediately visible entity on
5553 -- the homonym chain. This is the one we want unless there is another
5554 -- immediately visible entity further on in the chain for an inner
5555 -- scope (RM 8.3(8)).
5557 <<Immediately_Visible_Entity>> declare
5562 -- Find scope level of initial entity. When compiling through
5563 -- Rtsfind, the previous context is not completely invisible, and
5564 -- an outer entity may appear on the chain, whose scope is below
5565 -- the entry for Standard that delimits the current scope stack.
5566 -- Indicate that the level for this spurious entry is outside of
5567 -- the current scope stack.
5569 Level := Scope_Stack.Last;
5571 Scop := Scope_Stack.Table (Level).Entity;
5572 exit when Scop = Scope (E);
5574 exit when Scop = Standard_Standard;
5577 -- Now search remainder of homonym chain for more inner entry
5578 -- If the entity is Standard itself, it has no scope, and we
5579 -- compare it with the stack entry directly.
5582 while Present (E2) loop
5583 if Is_Immediately_Visible (E2) then
5585 -- If a generic package contains a local declaration that
5586 -- has the same name as the generic, there may be a visibility
5587 -- conflict in an instance, where the local declaration must
5588 -- also hide the name of the corresponding package renaming.
5589 -- We check explicitly for a package declared by a renaming,
5590 -- whose renamed entity is an instance that is on the scope
5591 -- stack, and that contains a homonym in the same scope. Once
5592 -- we have found it, we know that the package renaming is not
5593 -- immediately visible, and that the identifier denotes the
5594 -- other entity (and its homonyms if overloaded).
5596 if Scope (E) = Scope (E2)
5597 and then Ekind (E) = E_Package
5598 and then Present (Renamed_Object (E))
5599 and then Is_Generic_Instance (Renamed_Object (E))
5600 and then In_Open_Scopes (Renamed_Object (E))
5601 and then Comes_From_Source (N)
5603 Set_Is_Immediately_Visible (E, False);
5607 for J in Level + 1 .. Scope_Stack.Last loop
5608 if Scope_Stack.Table (J).Entity = Scope (E2)
5609 or else Scope_Stack.Table (J).Entity = E2
5622 -- At the end of that loop, E is the innermost immediately
5623 -- visible entity, so we are all set.
5626 -- Come here with entity found, and stored in E
5630 -- Check violation of No_Wide_Characters restriction
5632 Check_Wide_Character_Restriction (E, N);
5634 -- When distribution features are available (Get_PCS_Name /=
5635 -- Name_No_DSA), a remote access-to-subprogram type is converted
5636 -- into a record type holding whatever information is needed to
5637 -- perform a remote call on an RCI subprogram. In that case we
5638 -- rewrite any occurrence of the RAS type into the equivalent record
5639 -- type here. 'Access attribute references and RAS dereferences are
5640 -- then implemented using specific TSSs. However when distribution is
5641 -- not available (case of Get_PCS_Name = Name_No_DSA), we bypass the
5642 -- generation of these TSSs, and we must keep the RAS type in its
5643 -- original access-to-subprogram form (since all calls through a
5644 -- value of such type will be local anyway in the absence of a PCS).
5646 if Comes_From_Source (N)
5647 and then Is_Remote_Access_To_Subprogram_Type (E)
5648 and then Ekind (E) = E_Access_Subprogram_Type
5649 and then Expander_Active
5650 and then Get_PCS_Name /= Name_No_DSA
5652 Rewrite (N, New_Occurrence_Of (Equivalent_Type (E), Sloc (N)));
5656 -- Set the entity. Note that the reason we call Set_Entity for the
5657 -- overloadable case, as opposed to Set_Entity_With_Checks is
5658 -- that in the overloaded case, the initial call can set the wrong
5659 -- homonym. The call that sets the right homonym is in Sem_Res and
5660 -- that call does use Set_Entity_With_Checks, so we don't miss
5663 if Is_Overloadable (E) then
5666 Set_Entity_With_Checks (N, E);
5672 Set_Etype (N, Get_Full_View (Etype (E)));
5675 if Debug_Flag_E then
5676 Write_Str (" found ");
5677 Write_Entity_Info (E, " ");
5680 -- If the Ekind of the entity is Void, it means that all homonyms
5681 -- are hidden from all visibility (RM 8.3(5,14-20)). However, this
5682 -- test is skipped if the current scope is a record and the name is
5683 -- a pragma argument expression (case of Atomic and Volatile pragmas
5684 -- and possibly other similar pragmas added later, which are allowed
5685 -- to reference components in the current record).
5687 if Ekind (E) = E_Void
5689 (not Is_Record_Type (Current_Scope)
5690 or else Nkind (Parent (N)) /= N_Pragma_Argument_Association)
5692 Premature_Usage (N);
5694 -- If the entity is overloadable, collect all interpretations of the
5695 -- name for subsequent overload resolution. We optimize a bit here to
5696 -- do this only if we have an overloadable entity that is not on its
5697 -- own on the homonym chain.
5699 elsif Is_Overloadable (E)
5700 and then (Present (Homonym (E)) or else Current_Entity (N) /= E)
5702 Collect_Interps (N);
5704 -- If no homonyms were visible, the entity is unambiguous
5706 if not Is_Overloaded (N) then
5707 if not Is_Actual_Parameter then
5708 Generate_Reference (E, N);
5712 -- Case of non-overloadable entity, set the entity providing that
5713 -- we do not have the case of a discriminant reference within a
5714 -- default expression. Such references are replaced with the
5715 -- corresponding discriminal, which is the formal corresponding to
5716 -- to the discriminant in the initialization procedure.
5719 -- Entity is unambiguous, indicate that it is referenced here
5721 -- For a renaming of an object, always generate simple reference,
5722 -- we don't try to keep track of assignments in this case, except
5723 -- in SPARK mode where renamings are traversed for generating
5724 -- local effects of subprograms.
5727 and then Present (Renamed_Object (E))
5728 and then not GNATprove_Mode
5730 Generate_Reference (E, N);
5732 -- If the renamed entity is a private protected component,
5733 -- reference the original component as well. This needs to be
5734 -- done because the private renamings are installed before any
5735 -- analysis has occurred. Reference to a private component will
5736 -- resolve to the renaming and the original component will be
5737 -- left unreferenced, hence the following.
5739 if Is_Prival (E) then
5740 Generate_Reference (Prival_Link (E), N);
5743 -- One odd case is that we do not want to set the Referenced flag
5744 -- if the entity is a label, and the identifier is the label in
5745 -- the source, since this is not a reference from the point of
5746 -- view of the user.
5748 elsif Nkind (Parent (N)) = N_Label then
5750 R : constant Boolean := Referenced (E);
5753 -- Generate reference unless this is an actual parameter
5754 -- (see comment below)
5756 if Is_Actual_Parameter then
5757 Generate_Reference (E, N);
5758 Set_Referenced (E, R);
5762 -- Normal case, not a label: generate reference
5765 if not Is_Actual_Parameter then
5767 -- Package or generic package is always a simple reference
5769 if Ekind_In (E, E_Package, E_Generic_Package) then
5770 Generate_Reference (E, N, 'r');
5772 -- Else see if we have a left hand side
5777 Generate_Reference (E, N, 'm');
5780 Generate_Reference (E, N, 'r');
5782 -- If we don't know now, generate reference later
5785 Deferred_References.Append ((E, N));
5791 Set_Entity_Or_Discriminal (N, E);
5793 -- The name may designate a generalized reference, in which case
5794 -- the dereference interpretation will be included. Context is
5795 -- one in which a name is legal.
5797 if Ada_Version >= Ada_2012
5799 (Nkind (Parent (N)) in N_Subexpr
5800 or else Nkind_In (Parent (N), N_Assignment_Statement,
5801 N_Object_Declaration,
5802 N_Parameter_Association))
5804 Check_Implicit_Dereference (N, Etype (E));
5809 -- Come here with entity set
5812 Check_Restriction_No_Use_Of_Entity (N);
5813 end Find_Direct_Name;
5815 ------------------------
5816 -- Find_Expanded_Name --
5817 ------------------------
5819 -- This routine searches the homonym chain of the entity until it finds
5820 -- an entity declared in the scope denoted by the prefix. If the entity
5821 -- is private, it may nevertheless be immediately visible, if we are in
5822 -- the scope of its declaration.
5824 procedure Find_Expanded_Name (N : Node_Id) is
5825 function In_Abstract_View_Pragma (Nod : Node_Id) return Boolean;
5826 -- Determine whether expanded name Nod appears within a pragma which is
5827 -- a suitable context for an abstract view of a state or variable. The
5828 -- following pragmas fall in this category:
5835 -- In addition, pragma Abstract_State is also considered suitable even
5836 -- though it is an illegal context for an abstract view as this allows
5837 -- for proper resolution of abstract views of variables. This illegal
5838 -- context is later flagged in the analysis of indicator Part_Of.
5840 -----------------------------
5841 -- In_Abstract_View_Pragma --
5842 -----------------------------
5844 function In_Abstract_View_Pragma (Nod : Node_Id) return Boolean is
5848 -- Climb the parent chain looking for a pragma
5851 while Present (Par) loop
5852 if Nkind (Par) = N_Pragma then
5853 if Nam_In (Pragma_Name_Unmapped (Par),
5854 Name_Abstract_State,
5858 Name_Refined_Depends,
5859 Name_Refined_Global)
5863 -- Otherwise the pragma is not a legal context for an abstract
5870 -- Prevent the search from going too far
5872 elsif Is_Body_Or_Package_Declaration (Par) then
5876 Par := Parent (Par);
5880 end In_Abstract_View_Pragma;
5884 Selector : constant Node_Id := Selector_Name (N);
5885 Candidate : Entity_Id := Empty;
5889 -- Start of processing for Find_Expanded_Name
5892 P_Name := Entity (Prefix (N));
5894 -- If the prefix is a renamed package, look for the entity in the
5895 -- original package.
5897 if Ekind (P_Name) = E_Package
5898 and then Present (Renamed_Object (P_Name))
5900 P_Name := Renamed_Object (P_Name);
5902 -- Rewrite node with entity field pointing to renamed object
5904 Rewrite (Prefix (N), New_Copy (Prefix (N)));
5905 Set_Entity (Prefix (N), P_Name);
5907 -- If the prefix is an object of a concurrent type, look for
5908 -- the entity in the associated task or protected type.
5910 elsif Is_Concurrent_Type (Etype (P_Name)) then
5911 P_Name := Etype (P_Name);
5914 Id := Current_Entity (Selector);
5917 Is_New_Candidate : Boolean;
5920 while Present (Id) loop
5921 if Scope (Id) = P_Name then
5923 Is_New_Candidate := True;
5925 -- Handle abstract views of states and variables. These are
5926 -- acceptable candidates only when the reference to the view
5927 -- appears in certain pragmas.
5929 if Ekind (Id) = E_Abstract_State
5930 and then From_Limited_With (Id)
5931 and then Present (Non_Limited_View (Id))
5933 if In_Abstract_View_Pragma (N) then
5934 Candidate := Non_Limited_View (Id);
5935 Is_New_Candidate := True;
5937 -- Hide the candidate because it is not used in a proper
5942 Is_New_Candidate := False;
5946 -- Ada 2005 (AI-217): Handle shadow entities associated with
5947 -- types declared in limited-withed nested packages. We don't need
5948 -- to handle E_Incomplete_Subtype entities because the entities
5949 -- in the limited view are always E_Incomplete_Type and
5950 -- E_Class_Wide_Type entities (see Build_Limited_Views).
5952 -- Regarding the expression used to evaluate the scope, it
5953 -- is important to note that the limited view also has shadow
5954 -- entities associated nested packages. For this reason the
5955 -- correct scope of the entity is the scope of the real entity.
5956 -- The non-limited view may itself be incomplete, in which case
5957 -- get the full view if available.
5959 elsif Ekind_In (Id, E_Incomplete_Type, E_Class_Wide_Type)
5960 and then From_Limited_With (Id)
5961 and then Present (Non_Limited_View (Id))
5962 and then Scope (Non_Limited_View (Id)) = P_Name
5964 Candidate := Get_Full_View (Non_Limited_View (Id));
5965 Is_New_Candidate := True;
5968 Is_New_Candidate := False;
5971 if Is_New_Candidate then
5973 -- If entity is a child unit, either it is a visible child of
5974 -- the prefix, or we are in the body of a generic prefix, as
5975 -- will happen when a child unit is instantiated in the body
5976 -- of a generic parent. This is because the instance body does
5977 -- not restore the full compilation context, given that all
5978 -- non-local references have been captured.
5980 if Is_Child_Unit (Id) or else P_Name = Standard_Standard then
5981 exit when Is_Visible_Lib_Unit (Id)
5982 or else (Is_Child_Unit (Id)
5983 and then In_Open_Scopes (Scope (Id))
5984 and then In_Instance_Body);
5986 exit when not Is_Hidden (Id);
5989 exit when Is_Immediately_Visible (Id);
5997 and then Ekind_In (P_Name, E_Procedure, E_Function)
5998 and then Is_Generic_Instance (P_Name)
6000 -- Expanded name denotes entity in (instance of) generic subprogram.
6001 -- The entity may be in the subprogram instance, or may denote one of
6002 -- the formals, which is declared in the enclosing wrapper package.
6004 P_Name := Scope (P_Name);
6006 Id := Current_Entity (Selector);
6007 while Present (Id) loop
6008 exit when Scope (Id) = P_Name;
6013 if No (Id) or else Chars (Id) /= Chars (Selector) then
6014 Set_Etype (N, Any_Type);
6016 -- If we are looking for an entity defined in System, try to find it
6017 -- in the child package that may have been provided as an extension
6018 -- to System. The Extend_System pragma will have supplied the name of
6019 -- the extension, which may have to be loaded.
6021 if Chars (P_Name) = Name_System
6022 and then Scope (P_Name) = Standard_Standard
6023 and then Present (System_Extend_Unit)
6024 and then Present_System_Aux (N)
6026 Set_Entity (Prefix (N), System_Aux_Id);
6027 Find_Expanded_Name (N);
6030 -- There is an implicit instance of the predefined operator in
6031 -- the given scope. The operator entity is defined in Standard.
6032 -- Has_Implicit_Operator makes the node into an Expanded_Name.
6034 elsif Nkind (Selector) = N_Operator_Symbol
6035 and then Has_Implicit_Operator (N)
6039 -- If there is no literal defined in the scope denoted by the
6040 -- prefix, the literal may belong to (a type derived from)
6041 -- Standard_Character, for which we have no explicit literals.
6043 elsif Nkind (Selector) = N_Character_Literal
6044 and then Has_Implicit_Character_Literal (N)
6049 -- If the prefix is a single concurrent object, use its name in
6050 -- the error message, rather than that of the anonymous type.
6052 if Is_Concurrent_Type (P_Name)
6053 and then Is_Internal_Name (Chars (P_Name))
6055 Error_Msg_Node_2 := Entity (Prefix (N));
6057 Error_Msg_Node_2 := P_Name;
6060 if P_Name = System_Aux_Id then
6061 P_Name := Scope (P_Name);
6062 Set_Entity (Prefix (N), P_Name);
6065 if Present (Candidate) then
6067 -- If we know that the unit is a child unit we can give a more
6068 -- accurate error message.
6070 if Is_Child_Unit (Candidate) then
6072 -- If the candidate is a private child unit and we are in
6073 -- the visible part of a public unit, specialize the error
6074 -- message. There might be a private with_clause for it,
6075 -- but it is not currently active.
6077 if Is_Private_Descendant (Candidate)
6078 and then Ekind (Current_Scope) = E_Package
6079 and then not In_Private_Part (Current_Scope)
6080 and then not Is_Private_Descendant (Current_Scope)
6083 ("private child unit& is not visible here", Selector);
6085 -- Normal case where we have a missing with for a child unit
6088 Error_Msg_Qual_Level := 99;
6089 Error_Msg_NE -- CODEFIX
6090 ("missing `WITH &;`", Selector, Candidate);
6091 Error_Msg_Qual_Level := 0;
6094 -- Here we don't know that this is a child unit
6097 Error_Msg_NE ("& is not a visible entity of&", N, Selector);
6101 -- Within the instantiation of a child unit, the prefix may
6102 -- denote the parent instance, but the selector has the name
6103 -- of the original child. That is to say, when A.B appears
6104 -- within an instantiation of generic child unit B, the scope
6105 -- stack includes an instance of A (P_Name) and an instance
6106 -- of B under some other name. We scan the scope to find this
6107 -- child instance, which is the desired entity.
6108 -- Note that the parent may itself be a child instance, if
6109 -- the reference is of the form A.B.C, in which case A.B has
6110 -- already been rewritten with the proper entity.
6112 if In_Open_Scopes (P_Name)
6113 and then Is_Generic_Instance (P_Name)
6116 Gen_Par : constant Entity_Id :=
6117 Generic_Parent (Specification
6118 (Unit_Declaration_Node (P_Name)));
6119 S : Entity_Id := Current_Scope;
6123 for J in reverse 0 .. Scope_Stack.Last loop
6124 S := Scope_Stack.Table (J).Entity;
6126 exit when S = Standard_Standard;
6128 if Ekind_In (S, E_Function,
6133 Generic_Parent (Specification
6134 (Unit_Declaration_Node (S)));
6136 -- Check that P is a generic child of the generic
6137 -- parent of the prefix.
6140 and then Chars (P) = Chars (Selector)
6141 and then Scope (P) = Gen_Par
6152 -- If this is a selection from Ada, System or Interfaces, then
6153 -- we assume a missing with for the corresponding package.
6155 if Is_Known_Unit (N) then
6156 if not Error_Posted (N) then
6157 Error_Msg_Node_2 := Selector;
6158 Error_Msg_N -- CODEFIX
6159 ("missing `WITH &.&;`", Prefix (N));
6162 -- If this is a selection from a dummy package, then suppress
6163 -- the error message, of course the entity is missing if the
6164 -- package is missing.
6166 elsif Sloc (Error_Msg_Node_2) = No_Location then
6169 -- Here we have the case of an undefined component
6172 -- The prefix may hide a homonym in the context that
6173 -- declares the desired entity. This error can use a
6174 -- specialized message.
6176 if In_Open_Scopes (P_Name) then
6178 H : constant Entity_Id := Homonym (P_Name);
6182 and then Is_Compilation_Unit (H)
6184 (Is_Immediately_Visible (H)
6185 or else Is_Visible_Lib_Unit (H))
6187 Id := First_Entity (H);
6188 while Present (Id) loop
6189 if Chars (Id) = Chars (Selector) then
6190 Error_Msg_Qual_Level := 99;
6191 Error_Msg_Name_1 := Chars (Selector);
6193 ("% not declared in&", N, P_Name);
6195 ("\use fully qualified name starting with "
6196 & "Standard to make& visible", N, H);
6197 Error_Msg_Qual_Level := 0;
6205 -- If not found, standard error message
6207 Error_Msg_NE ("& not declared in&", N, Selector);
6213 Error_Msg_NE ("& not declared in&", N, Selector);
6216 -- Check for misspelling of some entity in prefix
6218 Id := First_Entity (P_Name);
6219 while Present (Id) loop
6220 if Is_Bad_Spelling_Of (Chars (Id), Chars (Selector))
6221 and then not Is_Internal_Name (Chars (Id))
6223 Error_Msg_NE -- CODEFIX
6224 ("possible misspelling of&", Selector, Id);
6231 -- Specialize the message if this may be an instantiation
6232 -- of a child unit that was not mentioned in the context.
6234 if Nkind (Parent (N)) = N_Package_Instantiation
6235 and then Is_Generic_Instance (Entity (Prefix (N)))
6236 and then Is_Compilation_Unit
6237 (Generic_Parent (Parent (Entity (Prefix (N)))))
6239 Error_Msg_Node_2 := Selector;
6240 Error_Msg_N -- CODEFIX
6241 ("\missing `WITH &.&;`", Prefix (N));
6251 if Comes_From_Source (N)
6252 and then Is_Remote_Access_To_Subprogram_Type (Id)
6253 and then Ekind (Id) = E_Access_Subprogram_Type
6254 and then Present (Equivalent_Type (Id))
6256 -- If we are not actually generating distribution code (i.e. the
6257 -- current PCS is the dummy non-distributed version), then the
6258 -- Equivalent_Type will be missing, and Id should be treated as
6259 -- a regular access-to-subprogram type.
6261 Id := Equivalent_Type (Id);
6262 Set_Chars (Selector, Chars (Id));
6265 -- Ada 2005 (AI-50217): Check usage of entities in limited withed units
6267 if Ekind (P_Name) = E_Package and then From_Limited_With (P_Name) then
6268 if From_Limited_With (Id)
6269 or else Is_Type (Id)
6270 or else Ekind (Id) = E_Package
6275 ("limited withed package can only be used to access incomplete "
6280 if Is_Task_Type (P_Name)
6281 and then ((Ekind (Id) = E_Entry
6282 and then Nkind (Parent (N)) /= N_Attribute_Reference)
6284 (Ekind (Id) = E_Entry_Family
6286 Nkind (Parent (Parent (N))) /= N_Attribute_Reference))
6288 -- If both the task type and the entry are in scope, this may still
6289 -- be the expanded name of an entry formal.
6291 if In_Open_Scopes (Id)
6292 and then Nkind (Parent (N)) = N_Selected_Component
6297 -- It is an entry call after all, either to the current task
6298 -- (which will deadlock) or to an enclosing task.
6300 Analyze_Selected_Component (N);
6305 Change_Selected_Component_To_Expanded_Name (N);
6307 -- Set appropriate type
6309 if Is_Type (Id) then
6312 Set_Etype (N, Get_Full_View (Etype (Id)));
6315 -- Do style check and generate reference, but skip both steps if this
6316 -- entity has homonyms, since we may not have the right homonym set yet.
6317 -- The proper homonym will be set during the resolve phase.
6319 if Has_Homonym (Id) then
6323 Set_Entity_Or_Discriminal (N, Id);
6327 Generate_Reference (Id, N, 'm');
6330 Generate_Reference (Id, N, 'r');
6333 Deferred_References.Append ((Id, N));
6337 -- Check for violation of No_Wide_Characters
6339 Check_Wide_Character_Restriction (Id, N);
6341 -- If the Ekind of the entity is Void, it means that all homonyms are
6342 -- hidden from all visibility (RM 8.3(5,14-20)).
6344 if Ekind (Id) = E_Void then
6345 Premature_Usage (N);
6347 elsif Is_Overloadable (Id) and then Present (Homonym (Id)) then
6349 H : Entity_Id := Homonym (Id);
6352 while Present (H) loop
6353 if Scope (H) = Scope (Id)
6354 and then (not Is_Hidden (H)
6355 or else Is_Immediately_Visible (H))
6357 Collect_Interps (N);
6364 -- If an extension of System is present, collect possible explicit
6365 -- overloadings declared in the extension.
6367 if Chars (P_Name) = Name_System
6368 and then Scope (P_Name) = Standard_Standard
6369 and then Present (System_Extend_Unit)
6370 and then Present_System_Aux (N)
6372 H := Current_Entity (Id);
6374 while Present (H) loop
6375 if Scope (H) = System_Aux_Id then
6376 Add_One_Interp (N, H, Etype (H));
6385 if Nkind (Selector_Name (N)) = N_Operator_Symbol
6386 and then Scope (Id) /= Standard_Standard
6388 -- In addition to user-defined operators in the given scope, there
6389 -- may be an implicit instance of the predefined operator. The
6390 -- operator (defined in Standard) is found in Has_Implicit_Operator,
6391 -- and added to the interpretations. Procedure Add_One_Interp will
6392 -- determine which hides which.
6394 if Has_Implicit_Operator (N) then
6399 -- If there is a single interpretation for N we can generate a
6400 -- reference to the unique entity found.
6402 if Is_Overloadable (Id) and then not Is_Overloaded (N) then
6403 Generate_Reference (Id, N);
6406 Check_Restriction_No_Use_Of_Entity (N);
6407 end Find_Expanded_Name;
6409 -------------------------
6410 -- Find_Renamed_Entity --
6411 -------------------------
6413 function Find_Renamed_Entity
6417 Is_Actual : Boolean := False) return Entity_Id
6420 I1 : Interp_Index := 0; -- Suppress junk warnings
6426 function Is_Visible_Operation (Op : Entity_Id) return Boolean;
6427 -- If the renamed entity is an implicit operator, check whether it is
6428 -- visible because its operand type is properly visible. This check
6429 -- applies to explicit renamed entities that appear in the source in a
6430 -- renaming declaration or a formal subprogram instance, but not to
6431 -- default generic actuals with a name.
6433 function Report_Overload return Entity_Id;
6434 -- List possible interpretations, and specialize message in the
6435 -- case of a generic actual.
6437 function Within (Inner, Outer : Entity_Id) return Boolean;
6438 -- Determine whether a candidate subprogram is defined within the
6439 -- enclosing instance. If yes, it has precedence over outer candidates.
6441 --------------------------
6442 -- Is_Visible_Operation --
6443 --------------------------
6445 function Is_Visible_Operation (Op : Entity_Id) return Boolean is
6451 if Ekind (Op) /= E_Operator
6452 or else Scope (Op) /= Standard_Standard
6453 or else (In_Instance
6454 and then (not Is_Actual
6455 or else Present (Enclosing_Instance)))
6460 -- For a fixed point type operator, check the resulting type,
6461 -- because it may be a mixed mode integer * fixed operation.
6463 if Present (Next_Formal (First_Formal (New_S)))
6464 and then Is_Fixed_Point_Type (Etype (New_S))
6466 Typ := Etype (New_S);
6468 Typ := Etype (First_Formal (New_S));
6471 Btyp := Base_Type (Typ);
6473 if Nkind (Nam) /= N_Expanded_Name then
6474 return (In_Open_Scopes (Scope (Btyp))
6475 or else Is_Potentially_Use_Visible (Btyp)
6476 or else In_Use (Btyp)
6477 or else In_Use (Scope (Btyp)));
6480 Scop := Entity (Prefix (Nam));
6482 if Ekind (Scop) = E_Package
6483 and then Present (Renamed_Object (Scop))
6485 Scop := Renamed_Object (Scop);
6488 -- Operator is visible if prefix of expanded name denotes
6489 -- scope of type, or else type is defined in System_Aux
6490 -- and the prefix denotes System.
6492 return Scope (Btyp) = Scop
6493 or else (Scope (Btyp) = System_Aux_Id
6494 and then Scope (Scope (Btyp)) = Scop);
6497 end Is_Visible_Operation;
6503 function Within (Inner, Outer : Entity_Id) return Boolean is
6507 Sc := Scope (Inner);
6508 while Sc /= Standard_Standard loop
6519 ---------------------
6520 -- Report_Overload --
6521 ---------------------
6523 function Report_Overload return Entity_Id is
6526 Error_Msg_NE -- CODEFIX
6527 ("ambiguous actual subprogram&, " &
6528 "possible interpretations:", N, Nam);
6530 Error_Msg_N -- CODEFIX
6531 ("ambiguous subprogram, " &
6532 "possible interpretations:", N);
6535 List_Interps (Nam, N);
6537 end Report_Overload;
6539 -- Start of processing for Find_Renamed_Entity
6543 Candidate_Renaming := Empty;
6545 if Is_Overloaded (Nam) then
6546 Get_First_Interp (Nam, Ind, It);
6547 while Present (It.Nam) loop
6548 if Entity_Matches_Spec (It.Nam, New_S)
6549 and then Is_Visible_Operation (It.Nam)
6551 if Old_S /= Any_Id then
6553 -- Note: The call to Disambiguate only happens if a
6554 -- previous interpretation was found, in which case I1
6555 -- has received a value.
6557 It1 := Disambiguate (Nam, I1, Ind, Etype (Old_S));
6559 if It1 = No_Interp then
6560 Inst := Enclosing_Instance;
6562 if Present (Inst) then
6563 if Within (It.Nam, Inst) then
6564 if Within (Old_S, Inst) then
6566 -- Choose the innermost subprogram, which would
6567 -- have hidden the outer one in the generic.
6569 if Scope_Depth (It.Nam) <
6578 elsif Within (Old_S, Inst) then
6582 return Report_Overload;
6585 -- If not within an instance, ambiguity is real
6588 return Report_Overload;
6602 Present (First_Formal (It.Nam))
6603 and then Present (First_Formal (New_S))
6604 and then (Base_Type (Etype (First_Formal (It.Nam))) =
6605 Base_Type (Etype (First_Formal (New_S))))
6607 Candidate_Renaming := It.Nam;
6610 Get_Next_Interp (Ind, It);
6613 Set_Entity (Nam, Old_S);
6615 if Old_S /= Any_Id then
6616 Set_Is_Overloaded (Nam, False);
6619 -- Non-overloaded case
6623 and then Present (Enclosing_Instance)
6624 and then Entity_Matches_Spec (Entity (Nam), New_S)
6626 Old_S := Entity (Nam);
6628 elsif Entity_Matches_Spec (Entity (Nam), New_S) then
6629 Candidate_Renaming := New_S;
6631 if Is_Visible_Operation (Entity (Nam)) then
6632 Old_S := Entity (Nam);
6635 elsif Present (First_Formal (Entity (Nam)))
6636 and then Present (First_Formal (New_S))
6637 and then (Base_Type (Etype (First_Formal (Entity (Nam)))) =
6638 Base_Type (Etype (First_Formal (New_S))))
6640 Candidate_Renaming := Entity (Nam);
6645 end Find_Renamed_Entity;
6647 -----------------------------
6648 -- Find_Selected_Component --
6649 -----------------------------
6651 procedure Find_Selected_Component (N : Node_Id) is
6652 P : constant Node_Id := Prefix (N);
6655 -- Entity denoted by prefix
6662 function Available_Subtype return Boolean;
6663 -- A small optimization: if the prefix is constrained and the component
6664 -- is an array type we may already have a usable subtype for it, so we
6665 -- can use it rather than generating a new one, because the bounds
6666 -- will be the values of the discriminants and not discriminant refs.
6667 -- This simplifies value tracing in GNATProve. For consistency, both
6668 -- the entity name and the subtype come from the constrained component.
6670 -- This is only used in GNATProve mode: when generating code it may be
6671 -- necessary to create an itype in the scope of use of the selected
6672 -- component, e.g. in the context of a expanded record equality.
6674 function Is_Reference_In_Subunit return Boolean;
6675 -- In a subunit, the scope depth is not a proper measure of hiding,
6676 -- because the context of the proper body may itself hide entities in
6677 -- parent units. This rare case requires inspecting the tree directly
6678 -- because the proper body is inserted in the main unit and its context
6679 -- is simply added to that of the parent.
6681 -----------------------
6682 -- Available_Subtype --
6683 -----------------------
6685 function Available_Subtype return Boolean is
6689 if GNATprove_Mode then
6690 Comp := First_Entity (Etype (P));
6691 while Present (Comp) loop
6692 if Chars (Comp) = Chars (Selector_Name (N)) then
6693 Set_Etype (N, Etype (Comp));
6694 Set_Entity (Selector_Name (N), Comp);
6695 Set_Etype (Selector_Name (N), Etype (Comp));
6699 Next_Component (Comp);
6704 end Available_Subtype;
6706 -----------------------------
6707 -- Is_Reference_In_Subunit --
6708 -----------------------------
6710 function Is_Reference_In_Subunit return Boolean is
6712 Comp_Unit : Node_Id;
6716 while Present (Comp_Unit)
6717 and then Nkind (Comp_Unit) /= N_Compilation_Unit
6719 Comp_Unit := Parent (Comp_Unit);
6722 if No (Comp_Unit) or else Nkind (Unit (Comp_Unit)) /= N_Subunit then
6726 -- Now check whether the package is in the context of the subunit
6728 Clause := First (Context_Items (Comp_Unit));
6729 while Present (Clause) loop
6730 if Nkind (Clause) = N_With_Clause
6731 and then Entity (Name (Clause)) = P_Name
6736 Clause := Next (Clause);
6740 end Is_Reference_In_Subunit;
6742 -- Start of processing for Find_Selected_Component
6747 if Nkind (P) = N_Error then
6751 -- Selector name cannot be a character literal or an operator symbol in
6752 -- SPARK, except for the operator symbol in a renaming.
6754 if Restriction_Check_Required (SPARK_05) then
6755 if Nkind (Selector_Name (N)) = N_Character_Literal then
6756 Check_SPARK_05_Restriction
6757 ("character literal cannot be prefixed", N);
6758 elsif Nkind (Selector_Name (N)) = N_Operator_Symbol
6759 and then Nkind (Parent (N)) /= N_Subprogram_Renaming_Declaration
6761 Check_SPARK_05_Restriction
6762 ("operator symbol cannot be prefixed", N);
6766 -- If the selector already has an entity, the node has been constructed
6767 -- in the course of expansion, and is known to be valid. Do not verify
6768 -- that it is defined for the type (it may be a private component used
6769 -- in the expansion of record equality).
6771 if Present (Entity (Selector_Name (N))) then
6772 if No (Etype (N)) or else Etype (N) = Any_Type then
6774 Sel_Name : constant Node_Id := Selector_Name (N);
6775 Selector : constant Entity_Id := Entity (Sel_Name);
6779 Set_Etype (Sel_Name, Etype (Selector));
6781 if not Is_Entity_Name (P) then
6785 -- Build an actual subtype except for the first parameter
6786 -- of an init proc, where this actual subtype is by
6787 -- definition incorrect, since the object is uninitialized
6788 -- (and does not even have defined discriminants etc.)
6790 if Is_Entity_Name (P)
6791 and then Ekind (Entity (P)) = E_Function
6793 Nam := New_Copy (P);
6795 if Is_Overloaded (P) then
6796 Save_Interps (P, Nam);
6799 Rewrite (P, Make_Function_Call (Sloc (P), Name => Nam));
6801 Analyze_Selected_Component (N);
6804 elsif Ekind (Selector) = E_Component
6805 and then (not Is_Entity_Name (P)
6806 or else Chars (Entity (P)) /= Name_uInit)
6808 -- Check if we already have an available subtype we can use
6810 if Ekind (Etype (P)) = E_Record_Subtype
6811 and then Nkind (Parent (Etype (P))) = N_Subtype_Declaration
6812 and then Is_Array_Type (Etype (Selector))
6813 and then not Is_Packed (Etype (Selector))
6814 and then Available_Subtype
6818 -- Do not build the subtype when referencing components of
6819 -- dispatch table wrappers. Required to avoid generating
6820 -- elaboration code with HI runtimes.
6822 elsif RTU_Loaded (Ada_Tags)
6824 ((RTE_Available (RE_Dispatch_Table_Wrapper)
6825 and then Scope (Selector) =
6826 RTE (RE_Dispatch_Table_Wrapper))
6828 (RTE_Available (RE_No_Dispatch_Table_Wrapper)
6829 and then Scope (Selector) =
6830 RTE (RE_No_Dispatch_Table_Wrapper)))
6835 Build_Actual_Subtype_Of_Component
6836 (Etype (Selector), N);
6843 if No (C_Etype) then
6844 C_Etype := Etype (Selector);
6846 Insert_Action (N, C_Etype);
6847 C_Etype := Defining_Identifier (C_Etype);
6850 Set_Etype (N, C_Etype);
6853 -- If this is the name of an entry or protected operation, and
6854 -- the prefix is an access type, insert an explicit dereference,
6855 -- so that entry calls are treated uniformly.
6857 if Is_Access_Type (Etype (P))
6858 and then Is_Concurrent_Type (Designated_Type (Etype (P)))
6861 New_P : constant Node_Id :=
6862 Make_Explicit_Dereference (Sloc (P),
6863 Prefix => Relocate_Node (P));
6866 Set_Etype (P, Designated_Type (Etype (Prefix (P))));
6870 -- If the selected component appears within a default expression
6871 -- and it has an actual subtype, the pre-analysis has not yet
6872 -- completed its analysis, because Insert_Actions is disabled in
6873 -- that context. Within the init proc of the enclosing type we
6874 -- must complete this analysis, if an actual subtype was created.
6876 elsif Inside_Init_Proc then
6878 Typ : constant Entity_Id := Etype (N);
6879 Decl : constant Node_Id := Declaration_Node (Typ);
6881 if Nkind (Decl) = N_Subtype_Declaration
6882 and then not Analyzed (Decl)
6883 and then Is_List_Member (Decl)
6884 and then No (Parent (Decl))
6887 Insert_Action (N, Decl);
6894 elsif Is_Entity_Name (P) then
6895 P_Name := Entity (P);
6897 -- The prefix may denote an enclosing type which is the completion
6898 -- of an incomplete type declaration.
6900 if Is_Type (P_Name) then
6901 Set_Entity (P, Get_Full_View (P_Name));
6902 Set_Etype (P, Entity (P));
6903 P_Name := Entity (P);
6906 P_Type := Base_Type (Etype (P));
6908 if Debug_Flag_E then
6909 Write_Str ("Found prefix type to be ");
6910 Write_Entity_Info (P_Type, " "); Write_Eol;
6913 -- The designated type may be a limited view with no components.
6914 -- Check whether the non-limited view is available, because in some
6915 -- cases this will not be set when installing the context. Rewrite
6916 -- the node by introducing an explicit dereference at once, and
6917 -- setting the type of the rewritten prefix to the non-limited view
6918 -- of the original designated type.
6920 if Is_Access_Type (P_Type) then
6922 Desig_Typ : constant Entity_Id :=
6923 Directly_Designated_Type (P_Type);
6926 if Is_Incomplete_Type (Desig_Typ)
6927 and then From_Limited_With (Desig_Typ)
6928 and then Present (Non_Limited_View (Desig_Typ))
6931 Make_Explicit_Dereference (Sloc (P),
6932 Prefix => Relocate_Node (P)));
6934 Set_Etype (P, Get_Full_View (Non_Limited_View (Desig_Typ)));
6935 P_Type := Etype (P);
6940 -- First check for components of a record object (not the
6941 -- result of a call, which is handled below).
6943 if Is_Appropriate_For_Record (P_Type)
6944 and then not Is_Overloadable (P_Name)
6945 and then not Is_Type (P_Name)
6947 -- Selected component of record. Type checking will validate
6948 -- name of selector.
6950 -- ??? Could we rewrite an implicit dereference into an explicit
6953 Analyze_Selected_Component (N);
6955 -- Reference to type name in predicate/invariant expression
6957 elsif Is_Appropriate_For_Entry_Prefix (P_Type)
6958 and then not In_Open_Scopes (P_Name)
6959 and then (not Is_Concurrent_Type (Etype (P_Name))
6960 or else not In_Open_Scopes (Etype (P_Name)))
6962 -- Call to protected operation or entry. Type checking is
6963 -- needed on the prefix.
6965 Analyze_Selected_Component (N);
6967 elsif (In_Open_Scopes (P_Name)
6968 and then Ekind (P_Name) /= E_Void
6969 and then not Is_Overloadable (P_Name))
6970 or else (Is_Concurrent_Type (Etype (P_Name))
6971 and then In_Open_Scopes (Etype (P_Name)))
6973 -- Prefix denotes an enclosing loop, block, or task, i.e. an
6974 -- enclosing construct that is not a subprogram or accept.
6976 -- A special case: a protected body may call an operation
6977 -- on an external object of the same type, in which case it
6978 -- is not an expanded name. If the prefix is the type itself,
6979 -- or the context is a single synchronized object it can only
6980 -- be interpreted as an expanded name.
6982 if Is_Concurrent_Type (Etype (P_Name)) then
6984 or else Present (Anonymous_Object (Etype (P_Name)))
6986 Find_Expanded_Name (N);
6989 Analyze_Selected_Component (N);
6994 Find_Expanded_Name (N);
6997 elsif Ekind (P_Name) = E_Package then
6998 Find_Expanded_Name (N);
7000 elsif Is_Overloadable (P_Name) then
7002 -- The subprogram may be a renaming (of an enclosing scope) as
7003 -- in the case of the name of the generic within an instantiation.
7005 if Ekind_In (P_Name, E_Procedure, E_Function)
7006 and then Present (Alias (P_Name))
7007 and then Is_Generic_Instance (Alias (P_Name))
7009 P_Name := Alias (P_Name);
7012 if Is_Overloaded (P) then
7014 -- The prefix must resolve to a unique enclosing construct
7017 Found : Boolean := False;
7022 Get_First_Interp (P, Ind, It);
7023 while Present (It.Nam) loop
7024 if In_Open_Scopes (It.Nam) then
7027 "prefix must be unique enclosing scope", N);
7028 Set_Entity (N, Any_Id);
7029 Set_Etype (N, Any_Type);
7038 Get_Next_Interp (Ind, It);
7043 if In_Open_Scopes (P_Name) then
7044 Set_Entity (P, P_Name);
7045 Set_Is_Overloaded (P, False);
7046 Find_Expanded_Name (N);
7049 -- If no interpretation as an expanded name is possible, it
7050 -- must be a selected component of a record returned by a
7051 -- function call. Reformat prefix as a function call, the rest
7052 -- is done by type resolution.
7054 -- Error if the prefix is procedure or entry, as is P.X
7056 if Ekind (P_Name) /= E_Function
7058 (not Is_Overloaded (P)
7059 or else Nkind (Parent (N)) = N_Procedure_Call_Statement)
7061 -- Prefix may mention a package that is hidden by a local
7062 -- declaration: let the user know. Scan the full homonym
7063 -- chain, the candidate package may be anywhere on it.
7065 if Present (Homonym (Current_Entity (P_Name))) then
7066 P_Name := Current_Entity (P_Name);
7068 while Present (P_Name) loop
7069 exit when Ekind (P_Name) = E_Package;
7070 P_Name := Homonym (P_Name);
7073 if Present (P_Name) then
7074 if not Is_Reference_In_Subunit then
7075 Error_Msg_Sloc := Sloc (Entity (Prefix (N)));
7077 ("package& is hidden by declaration#", N, P_Name);
7080 Set_Entity (Prefix (N), P_Name);
7081 Find_Expanded_Name (N);
7085 P_Name := Entity (Prefix (N));
7090 ("invalid prefix in selected component&", N, P_Name);
7091 Change_Selected_Component_To_Expanded_Name (N);
7092 Set_Entity (N, Any_Id);
7093 Set_Etype (N, Any_Type);
7095 -- Here we have a function call, so do the reformatting
7098 Nam := New_Copy (P);
7099 Save_Interps (P, Nam);
7101 -- We use Replace here because this is one of those cases
7102 -- where the parser has missclassified the node, and we fix
7103 -- things up and then do the semantic analysis on the fixed
7104 -- up node. Normally we do this using one of the Sinfo.CN
7105 -- routines, but this is too tricky for that.
7107 -- Note that using Rewrite would be wrong, because we would
7108 -- have a tree where the original node is unanalyzed, and
7109 -- this violates the required interface for ASIS.
7112 Make_Function_Call (Sloc (P), Name => Nam));
7114 -- Now analyze the reformatted node
7118 -- If the prefix is illegal after this transformation, there
7119 -- may be visibility errors on the prefix. The safest is to
7120 -- treat the selected component as an error.
7122 if Error_Posted (P) then
7123 Set_Etype (N, Any_Type);
7127 Analyze_Selected_Component (N);
7132 -- Remaining cases generate various error messages
7135 -- Format node as expanded name, to avoid cascaded errors
7137 -- If the limited_with transformation was applied earlier, restore
7138 -- source for proper error reporting.
7140 if not Comes_From_Source (P)
7141 and then Nkind (P) = N_Explicit_Dereference
7143 Rewrite (P, Prefix (P));
7144 P_Type := Etype (P);
7147 Change_Selected_Component_To_Expanded_Name (N);
7148 Set_Entity (N, Any_Id);
7149 Set_Etype (N, Any_Type);
7151 -- Issue error message, but avoid this if error issued already.
7152 -- Use identifier of prefix if one is available.
7154 if P_Name = Any_Id then
7157 -- It is not an error if the prefix is the current instance of
7158 -- type name, e.g. the expression of a type aspect, when it is
7159 -- analyzed for ASIS use.
7161 elsif Is_Entity_Name (P) and then Is_Current_Instance (P) then
7164 elsif Ekind (P_Name) = E_Void then
7165 Premature_Usage (P);
7167 elsif Nkind (P) /= N_Attribute_Reference then
7169 -- This may have been meant as a prefixed call to a primitive
7170 -- of an untagged type. If it is a function call check type of
7171 -- its first formal and add explanation.
7174 F : constant Entity_Id :=
7175 Current_Entity (Selector_Name (N));
7178 and then Is_Overloadable (F)
7179 and then Present (First_Entity (F))
7180 and then not Is_Tagged_Type (Etype (First_Entity (F)))
7183 ("prefixed call is only allowed for objects of a "
7184 & "tagged type", N);
7188 Error_Msg_N ("invalid prefix in selected component&", P);
7190 if Is_Access_Type (P_Type)
7191 and then Ekind (Designated_Type (P_Type)) = E_Incomplete_Type
7194 ("\dereference must not be of an incomplete type "
7195 & "(RM 3.10.1)", P);
7199 Error_Msg_N ("invalid prefix in selected component", P);
7203 -- Selector name is restricted in SPARK
7205 if Nkind (N) = N_Expanded_Name
7206 and then Restriction_Check_Required (SPARK_05)
7208 if Is_Subprogram (P_Name) then
7209 Check_SPARK_05_Restriction
7210 ("prefix of expanded name cannot be a subprogram", P);
7211 elsif Ekind (P_Name) = E_Loop then
7212 Check_SPARK_05_Restriction
7213 ("prefix of expanded name cannot be a loop statement", P);
7218 -- If prefix is not the name of an entity, it must be an expression,
7219 -- whose type is appropriate for a record. This is determined by
7222 Analyze_Selected_Component (N);
7225 Analyze_Dimension (N);
7226 end Find_Selected_Component;
7232 procedure Find_Type (N : Node_Id) is
7242 elsif Nkind (N) = N_Attribute_Reference then
7244 -- Class attribute. This is not valid in Ada 83 mode, but we do not
7245 -- need to enforce that at this point, since the declaration of the
7246 -- tagged type in the prefix would have been flagged already.
7248 if Attribute_Name (N) = Name_Class then
7249 Check_Restriction (No_Dispatch, N);
7250 Find_Type (Prefix (N));
7252 -- Propagate error from bad prefix
7254 if Etype (Prefix (N)) = Any_Type then
7255 Set_Entity (N, Any_Type);
7256 Set_Etype (N, Any_Type);
7260 T := Base_Type (Entity (Prefix (N)));
7262 -- Case where type is not known to be tagged. Its appearance in
7263 -- the prefix of the 'Class attribute indicates that the full view
7266 if not Is_Tagged_Type (T) then
7267 if Ekind (T) = E_Incomplete_Type then
7269 -- It is legal to denote the class type of an incomplete
7270 -- type. The full type will have to be tagged, of course.
7271 -- In Ada 2005 this usage is declared obsolescent, so we
7272 -- warn accordingly. This usage is only legal if the type
7273 -- is completed in the current scope, and not for a limited
7276 if Ada_Version >= Ada_2005 then
7278 -- Test whether the Available_View of a limited type view
7279 -- is tagged, since the limited view may not be marked as
7280 -- tagged if the type itself has an untagged incomplete
7281 -- type view in its package.
7283 if From_Limited_With (T)
7284 and then not Is_Tagged_Type (Available_View (T))
7287 ("prefix of Class attribute must be tagged", N);
7288 Set_Etype (N, Any_Type);
7289 Set_Entity (N, Any_Type);
7292 -- ??? This test is temporarily disabled (always
7293 -- False) because it causes an unwanted warning on
7294 -- GNAT sources (built with -gnatg, which includes
7295 -- Warn_On_Obsolescent_ Feature). Once this issue
7296 -- is cleared in the sources, it can be enabled.
7298 elsif Warn_On_Obsolescent_Feature and then False then
7300 ("applying 'Class to an untagged incomplete type"
7301 & " is an obsolescent feature (RM J.11)?r?", N);
7305 Set_Is_Tagged_Type (T);
7306 Set_Direct_Primitive_Operations (T, New_Elmt_List);
7307 Make_Class_Wide_Type (T);
7308 Set_Entity (N, Class_Wide_Type (T));
7309 Set_Etype (N, Class_Wide_Type (T));
7311 elsif Ekind (T) = E_Private_Type
7312 and then not Is_Generic_Type (T)
7313 and then In_Private_Part (Scope (T))
7315 -- The Class attribute can be applied to an untagged private
7316 -- type fulfilled by a tagged type prior to the full type
7317 -- declaration (but only within the parent package's private
7318 -- part). Create the class-wide type now and check that the
7319 -- full type is tagged later during its analysis. Note that
7320 -- we do not mark the private type as tagged, unlike the
7321 -- case of incomplete types, because the type must still
7322 -- appear untagged to outside units.
7324 if No (Class_Wide_Type (T)) then
7325 Make_Class_Wide_Type (T);
7328 Set_Entity (N, Class_Wide_Type (T));
7329 Set_Etype (N, Class_Wide_Type (T));
7332 -- Should we introduce a type Any_Tagged and use Wrong_Type
7333 -- here, it would be a bit more consistent???
7336 ("tagged type required, found}",
7337 Prefix (N), First_Subtype (T));
7338 Set_Entity (N, Any_Type);
7342 -- Case of tagged type
7345 if Is_Concurrent_Type (T) then
7346 if No (Corresponding_Record_Type (Entity (Prefix (N)))) then
7348 -- Previous error. Use current type, which at least
7349 -- provides some operations.
7351 C := Entity (Prefix (N));
7354 C := Class_Wide_Type
7355 (Corresponding_Record_Type (Entity (Prefix (N))));
7359 C := Class_Wide_Type (Entity (Prefix (N)));
7362 Set_Entity_With_Checks (N, C);
7363 Generate_Reference (C, N);
7367 -- Base attribute, not allowed in Ada 83
7369 elsif Attribute_Name (N) = Name_Base then
7370 Error_Msg_Name_1 := Name_Base;
7371 Check_SPARK_05_Restriction
7372 ("attribute% is only allowed as prefix of another attribute", N);
7374 if Ada_Version = Ada_83 and then Comes_From_Source (N) then
7376 ("(Ada 83) Base attribute not allowed in subtype mark", N);
7379 Find_Type (Prefix (N));
7380 Typ := Entity (Prefix (N));
7382 if Ada_Version >= Ada_95
7383 and then not Is_Scalar_Type (Typ)
7384 and then not Is_Generic_Type (Typ)
7387 ("prefix of Base attribute must be scalar type",
7390 elsif Warn_On_Redundant_Constructs
7391 and then Base_Type (Typ) = Typ
7393 Error_Msg_NE -- CODEFIX
7394 ("redundant attribute, & is its own base type?r?", N, Typ);
7397 T := Base_Type (Typ);
7399 -- Rewrite attribute reference with type itself (see similar
7400 -- processing in Analyze_Attribute, case Base). Preserve prefix
7401 -- if present, for other legality checks.
7403 if Nkind (Prefix (N)) = N_Expanded_Name then
7405 Make_Expanded_Name (Sloc (N),
7407 Prefix => New_Copy (Prefix (Prefix (N))),
7408 Selector_Name => New_Occurrence_Of (T, Sloc (N))));
7411 Rewrite (N, New_Occurrence_Of (T, Sloc (N)));
7418 elsif Attribute_Name (N) = Name_Stub_Type then
7420 -- This is handled in Analyze_Attribute
7424 -- All other attributes are invalid in a subtype mark
7427 Error_Msg_N ("invalid attribute in subtype mark", N);
7433 if Is_Entity_Name (N) then
7434 T_Name := Entity (N);
7436 Error_Msg_N ("subtype mark required in this context", N);
7437 Set_Etype (N, Any_Type);
7441 if T_Name = Any_Id or else Etype (N) = Any_Type then
7443 -- Undefined id. Make it into a valid type
7445 Set_Entity (N, Any_Type);
7447 elsif not Is_Type (T_Name)
7448 and then T_Name /= Standard_Void_Type
7450 Error_Msg_Sloc := Sloc (T_Name);
7451 Error_Msg_N ("subtype mark required in this context", N);
7452 Error_Msg_NE ("\\found & declared#", N, T_Name);
7453 Set_Entity (N, Any_Type);
7456 -- If the type is an incomplete type created to handle
7457 -- anonymous access components of a record type, then the
7458 -- incomplete type is the visible entity and subsequent
7459 -- references will point to it. Mark the original full
7460 -- type as referenced, to prevent spurious warnings.
7462 if Is_Incomplete_Type (T_Name)
7463 and then Present (Full_View (T_Name))
7464 and then not Comes_From_Source (T_Name)
7466 Set_Referenced (Full_View (T_Name));
7469 T_Name := Get_Full_View (T_Name);
7471 -- Ada 2005 (AI-251, AI-50217): Handle interfaces visible through
7472 -- limited-with clauses
7474 if From_Limited_With (T_Name)
7475 and then Ekind (T_Name) in Incomplete_Kind
7476 and then Present (Non_Limited_View (T_Name))
7477 and then Is_Interface (Non_Limited_View (T_Name))
7479 T_Name := Non_Limited_View (T_Name);
7482 if In_Open_Scopes (T_Name) then
7483 if Ekind (Base_Type (T_Name)) = E_Task_Type then
7485 -- In Ada 2005, a task name can be used in an access
7486 -- definition within its own body. It cannot be used
7487 -- in the discriminant part of the task declaration,
7488 -- nor anywhere else in the declaration because entries
7489 -- cannot have access parameters.
7491 if Ada_Version >= Ada_2005
7492 and then Nkind (Parent (N)) = N_Access_Definition
7494 Set_Entity (N, T_Name);
7495 Set_Etype (N, T_Name);
7497 if Has_Completion (T_Name) then
7502 ("task type cannot be used as type mark " &
7503 "within its own declaration", N);
7508 ("task type cannot be used as type mark " &
7509 "within its own spec or body", N);
7512 elsif Ekind (Base_Type (T_Name)) = E_Protected_Type then
7514 -- In Ada 2005, a protected name can be used in an access
7515 -- definition within its own body.
7517 if Ada_Version >= Ada_2005
7518 and then Nkind (Parent (N)) = N_Access_Definition
7520 Set_Entity (N, T_Name);
7521 Set_Etype (N, T_Name);
7526 ("protected type cannot be used as type mark " &
7527 "within its own spec or body", N);
7531 Error_Msg_N ("type declaration cannot refer to itself", N);
7534 Set_Etype (N, Any_Type);
7535 Set_Entity (N, Any_Type);
7536 Set_Error_Posted (T_Name);
7540 Set_Entity (N, T_Name);
7541 Set_Etype (N, T_Name);
7545 if Present (Etype (N)) and then Comes_From_Source (N) then
7546 if Is_Fixed_Point_Type (Etype (N)) then
7547 Check_Restriction (No_Fixed_Point, N);
7548 elsif Is_Floating_Point_Type (Etype (N)) then
7549 Check_Restriction (No_Floating_Point, N);
7552 -- A Ghost type must appear in a specific context
7554 if Is_Ghost_Entity (Etype (N)) then
7555 Check_Ghost_Context (Etype (N), N);
7560 ------------------------------------
7561 -- Has_Implicit_Character_Literal --
7562 ------------------------------------
7564 function Has_Implicit_Character_Literal (N : Node_Id) return Boolean is
7566 Found : Boolean := False;
7567 P : constant Entity_Id := Entity (Prefix (N));
7568 Priv_Id : Entity_Id := Empty;
7571 if Ekind (P) = E_Package and then not In_Open_Scopes (P) then
7572 Priv_Id := First_Private_Entity (P);
7575 if P = Standard_Standard then
7576 Change_Selected_Component_To_Expanded_Name (N);
7577 Rewrite (N, Selector_Name (N));
7579 Set_Etype (Original_Node (N), Standard_Character);
7583 Id := First_Entity (P);
7584 while Present (Id) and then Id /= Priv_Id loop
7585 if Is_Standard_Character_Type (Id) and then Is_Base_Type (Id) then
7587 -- We replace the node with the literal itself, resolve as a
7588 -- character, and set the type correctly.
7591 Change_Selected_Component_To_Expanded_Name (N);
7592 Rewrite (N, Selector_Name (N));
7595 Set_Etype (Original_Node (N), Id);
7599 -- More than one type derived from Character in given scope.
7600 -- Collect all possible interpretations.
7602 Add_One_Interp (N, Id, Id);
7610 end Has_Implicit_Character_Literal;
7612 ----------------------
7613 -- Has_Private_With --
7614 ----------------------
7616 function Has_Private_With (E : Entity_Id) return Boolean is
7617 Comp_Unit : constant Node_Id := Cunit (Current_Sem_Unit);
7621 Item := First (Context_Items (Comp_Unit));
7622 while Present (Item) loop
7623 if Nkind (Item) = N_With_Clause
7624 and then Private_Present (Item)
7625 and then Entity (Name (Item)) = E
7634 end Has_Private_With;
7636 ---------------------------
7637 -- Has_Implicit_Operator --
7638 ---------------------------
7640 function Has_Implicit_Operator (N : Node_Id) return Boolean is
7641 Op_Id : constant Name_Id := Chars (Selector_Name (N));
7642 P : constant Entity_Id := Entity (Prefix (N));
7644 Priv_Id : Entity_Id := Empty;
7646 procedure Add_Implicit_Operator
7648 Op_Type : Entity_Id := Empty);
7649 -- Add implicit interpretation to node N, using the type for which a
7650 -- predefined operator exists. If the operator yields a boolean type,
7651 -- the Operand_Type is implicitly referenced by the operator, and a
7652 -- reference to it must be generated.
7654 ---------------------------
7655 -- Add_Implicit_Operator --
7656 ---------------------------
7658 procedure Add_Implicit_Operator
7660 Op_Type : Entity_Id := Empty)
7662 Predef_Op : Entity_Id;
7665 Predef_Op := Current_Entity (Selector_Name (N));
7666 while Present (Predef_Op)
7667 and then Scope (Predef_Op) /= Standard_Standard
7669 Predef_Op := Homonym (Predef_Op);
7672 if Nkind (N) = N_Selected_Component then
7673 Change_Selected_Component_To_Expanded_Name (N);
7676 -- If the context is an unanalyzed function call, determine whether
7677 -- a binary or unary interpretation is required.
7679 if Nkind (Parent (N)) = N_Indexed_Component then
7681 Is_Binary_Call : constant Boolean :=
7683 (Next (First (Expressions (Parent (N)))));
7684 Is_Binary_Op : constant Boolean :=
7686 (Predef_Op) /= Last_Entity (Predef_Op);
7687 Predef_Op2 : constant Entity_Id := Homonym (Predef_Op);
7690 if Is_Binary_Call then
7691 if Is_Binary_Op then
7692 Add_One_Interp (N, Predef_Op, T);
7694 Add_One_Interp (N, Predef_Op2, T);
7698 if not Is_Binary_Op then
7699 Add_One_Interp (N, Predef_Op, T);
7701 Add_One_Interp (N, Predef_Op2, T);
7707 Add_One_Interp (N, Predef_Op, T);
7709 -- For operators with unary and binary interpretations, if
7710 -- context is not a call, add both
7712 if Present (Homonym (Predef_Op)) then
7713 Add_One_Interp (N, Homonym (Predef_Op), T);
7717 -- The node is a reference to a predefined operator, and
7718 -- an implicit reference to the type of its operands.
7720 if Present (Op_Type) then
7721 Generate_Operator_Reference (N, Op_Type);
7723 Generate_Operator_Reference (N, T);
7725 end Add_Implicit_Operator;
7727 -- Start of processing for Has_Implicit_Operator
7730 if Ekind (P) = E_Package and then not In_Open_Scopes (P) then
7731 Priv_Id := First_Private_Entity (P);
7734 Id := First_Entity (P);
7738 -- Boolean operators: an implicit declaration exists if the scope
7739 -- contains a declaration for a derived Boolean type, or for an
7740 -- array of Boolean type.
7747 while Id /= Priv_Id loop
7748 if Valid_Boolean_Arg (Id) and then Is_Base_Type (Id) then
7749 Add_Implicit_Operator (Id);
7756 -- Equality: look for any non-limited type (result is Boolean)
7761 while Id /= Priv_Id loop
7763 and then not Is_Limited_Type (Id)
7764 and then Is_Base_Type (Id)
7766 Add_Implicit_Operator (Standard_Boolean, Id);
7773 -- Comparison operators: scalar type, or array of scalar
7780 while Id /= Priv_Id loop
7781 if (Is_Scalar_Type (Id)
7782 or else (Is_Array_Type (Id)
7783 and then Is_Scalar_Type (Component_Type (Id))))
7784 and then Is_Base_Type (Id)
7786 Add_Implicit_Operator (Standard_Boolean, Id);
7793 -- Arithmetic operators: any numeric type
7804 while Id /= Priv_Id loop
7805 if Is_Numeric_Type (Id) and then Is_Base_Type (Id) then
7806 Add_Implicit_Operator (Id);
7813 -- Concatenation: any one-dimensional array type
7815 when Name_Op_Concat =>
7816 while Id /= Priv_Id loop
7817 if Is_Array_Type (Id)
7818 and then Number_Dimensions (Id) = 1
7819 and then Is_Base_Type (Id)
7821 Add_Implicit_Operator (Id);
7828 -- What is the others condition here? Should we be using a
7829 -- subtype of Name_Id that would restrict to operators ???
7835 -- If we fall through, then we do not have an implicit operator
7838 end Has_Implicit_Operator;
7840 -----------------------------------
7841 -- Has_Loop_In_Inner_Open_Scopes --
7842 -----------------------------------
7844 function Has_Loop_In_Inner_Open_Scopes (S : Entity_Id) return Boolean is
7846 -- Several scope stacks are maintained by Scope_Stack. The base of the
7847 -- currently active scope stack is denoted by the Is_Active_Stack_Base
7848 -- flag in the scope stack entry. Note that the scope stacks used to
7849 -- simply be delimited implicitly by the presence of Standard_Standard
7850 -- at their base, but there now are cases where this is not sufficient
7851 -- because Standard_Standard actually may appear in the middle of the
7852 -- active set of scopes.
7854 for J in reverse 0 .. Scope_Stack.Last loop
7856 -- S was reached without seing a loop scope first
7858 if Scope_Stack.Table (J).Entity = S then
7861 -- S was not yet reached, so it contains at least one inner loop
7863 elsif Ekind (Scope_Stack.Table (J).Entity) = E_Loop then
7867 -- Check Is_Active_Stack_Base to tell us when to stop, as there are
7868 -- cases where Standard_Standard appears in the middle of the active
7869 -- set of scopes. This affects the declaration and overriding of
7870 -- private inherited operations in instantiations of generic child
7873 pragma Assert (not Scope_Stack.Table (J).Is_Active_Stack_Base);
7876 raise Program_Error; -- unreachable
7877 end Has_Loop_In_Inner_Open_Scopes;
7879 --------------------
7880 -- In_Open_Scopes --
7881 --------------------
7883 function In_Open_Scopes (S : Entity_Id) return Boolean is
7885 -- Several scope stacks are maintained by Scope_Stack. The base of the
7886 -- currently active scope stack is denoted by the Is_Active_Stack_Base
7887 -- flag in the scope stack entry. Note that the scope stacks used to
7888 -- simply be delimited implicitly by the presence of Standard_Standard
7889 -- at their base, but there now are cases where this is not sufficient
7890 -- because Standard_Standard actually may appear in the middle of the
7891 -- active set of scopes.
7893 for J in reverse 0 .. Scope_Stack.Last loop
7894 if Scope_Stack.Table (J).Entity = S then
7898 -- Check Is_Active_Stack_Base to tell us when to stop, as there are
7899 -- cases where Standard_Standard appears in the middle of the active
7900 -- set of scopes. This affects the declaration and overriding of
7901 -- private inherited operations in instantiations of generic child
7904 exit when Scope_Stack.Table (J).Is_Active_Stack_Base;
7910 -----------------------------
7911 -- Inherit_Renamed_Profile --
7912 -----------------------------
7914 procedure Inherit_Renamed_Profile (New_S : Entity_Id; Old_S : Entity_Id) is
7921 if Ekind (Old_S) = E_Operator then
7922 New_F := First_Formal (New_S);
7924 while Present (New_F) loop
7925 Set_Etype (New_F, Base_Type (Etype (New_F)));
7926 Next_Formal (New_F);
7929 Set_Etype (New_S, Base_Type (Etype (New_S)));
7932 New_F := First_Formal (New_S);
7933 Old_F := First_Formal (Old_S);
7935 while Present (New_F) loop
7936 New_T := Etype (New_F);
7937 Old_T := Etype (Old_F);
7939 -- If the new type is a renaming of the old one, as is the case
7940 -- for actuals in instances, retain its name, to simplify later
7943 if Nkind (Parent (New_T)) = N_Subtype_Declaration
7944 and then Is_Entity_Name (Subtype_Indication (Parent (New_T)))
7945 and then Entity (Subtype_Indication (Parent (New_T))) = Old_T
7949 Set_Etype (New_F, Old_T);
7952 Next_Formal (New_F);
7953 Next_Formal (Old_F);
7956 pragma Assert (No (Old_F));
7958 if Ekind_In (Old_S, E_Function, E_Enumeration_Literal) then
7959 Set_Etype (New_S, Etype (Old_S));
7962 end Inherit_Renamed_Profile;
7968 procedure Initialize is
7973 -------------------------
7974 -- Install_Use_Clauses --
7975 -------------------------
7977 procedure Install_Use_Clauses
7979 Force_Installation : Boolean := False)
7987 while Present (U) loop
7989 -- Case of USE package
7991 if Nkind (U) = N_Use_Package_Clause then
7992 P := First (Names (U));
7993 while Present (P) loop
7996 if Ekind (Id) = E_Package then
7998 Note_Redundant_Use (P);
8000 elsif Present (Renamed_Object (Id))
8001 and then In_Use (Renamed_Object (Id))
8003 Note_Redundant_Use (P);
8005 elsif Force_Installation or else Applicable_Use (P) then
8006 Use_One_Package (Id, U);
8017 P := First (Subtype_Marks (U));
8018 while Present (P) loop
8019 if not Is_Entity_Name (P)
8020 or else No (Entity (P))
8024 elsif Entity (P) /= Any_Type then
8032 Next_Use_Clause (U);
8034 end Install_Use_Clauses;
8036 -------------------------------------
8037 -- Is_Appropriate_For_Entry_Prefix --
8038 -------------------------------------
8040 function Is_Appropriate_For_Entry_Prefix (T : Entity_Id) return Boolean is
8041 P_Type : Entity_Id := T;
8044 if Is_Access_Type (P_Type) then
8045 P_Type := Designated_Type (P_Type);
8048 return Is_Task_Type (P_Type) or else Is_Protected_Type (P_Type);
8049 end Is_Appropriate_For_Entry_Prefix;
8051 -------------------------------
8052 -- Is_Appropriate_For_Record --
8053 -------------------------------
8055 function Is_Appropriate_For_Record (T : Entity_Id) return Boolean is
8057 function Has_Components (T1 : Entity_Id) return Boolean;
8058 -- Determine if given type has components (i.e. is either a record
8059 -- type or a type that has discriminants).
8061 --------------------
8062 -- Has_Components --
8063 --------------------
8065 function Has_Components (T1 : Entity_Id) return Boolean is
8067 return Is_Record_Type (T1)
8068 or else (Is_Private_Type (T1) and then Has_Discriminants (T1))
8069 or else (Is_Task_Type (T1) and then Has_Discriminants (T1))
8070 or else (Is_Incomplete_Type (T1)
8071 and then From_Limited_With (T1)
8072 and then Present (Non_Limited_View (T1))
8073 and then Is_Record_Type
8074 (Get_Full_View (Non_Limited_View (T1))));
8077 -- Start of processing for Is_Appropriate_For_Record
8082 and then (Has_Components (T)
8083 or else (Is_Access_Type (T)
8084 and then Has_Components (Designated_Type (T))));
8085 end Is_Appropriate_For_Record;
8087 ------------------------
8088 -- Note_Redundant_Use --
8089 ------------------------
8091 procedure Note_Redundant_Use (Clause : Node_Id) is
8092 Pack_Name : constant Entity_Id := Entity (Clause);
8093 Cur_Use : constant Node_Id := Current_Use_Clause (Pack_Name);
8094 Decl : constant Node_Id := Parent (Clause);
8096 Prev_Use : Node_Id := Empty;
8097 Redundant : Node_Id := Empty;
8098 -- The Use_Clause which is actually redundant. In the simplest case it
8099 -- is Pack itself, but when we compile a body we install its context
8100 -- before that of its spec, in which case it is the use_clause in the
8101 -- spec that will appear to be redundant, and we want the warning to be
8102 -- placed on the body. Similar complications appear when the redundancy
8103 -- is between a child unit and one of its ancestors.
8106 Set_Redundant_Use (Clause, True);
8108 if not Comes_From_Source (Clause)
8110 or else not Warn_On_Redundant_Constructs
8115 if not Is_Compilation_Unit (Current_Scope) then
8117 -- If the use_clause is in an inner scope, it is made redundant by
8118 -- some clause in the current context, with one exception: If we're
8119 -- compiling a nested package body, and the use_clause comes from the
8120 -- corresponding spec, the clause is not necessarily fully redundant,
8121 -- so we should not warn. If a warning was warranted, it would have
8122 -- been given when the spec was processed.
8124 if Nkind (Parent (Decl)) = N_Package_Specification then
8126 Package_Spec_Entity : constant Entity_Id :=
8127 Defining_Unit_Name (Parent (Decl));
8129 if In_Package_Body (Package_Spec_Entity) then
8135 Redundant := Clause;
8136 Prev_Use := Cur_Use;
8138 elsif Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Body then
8140 Cur_Unit : constant Unit_Number_Type := Get_Source_Unit (Cur_Use);
8141 New_Unit : constant Unit_Number_Type := Get_Source_Unit (Clause);
8145 if Cur_Unit = New_Unit then
8147 -- Redundant clause in same body
8149 Redundant := Clause;
8150 Prev_Use := Cur_Use;
8152 elsif Cur_Unit = Current_Sem_Unit then
8154 -- If the new clause is not in the current unit it has been
8155 -- analyzed first, and it makes the other one redundant.
8156 -- However, if the new clause appears in a subunit, Cur_Unit
8157 -- is still the parent, and in that case the redundant one
8158 -- is the one appearing in the subunit.
8160 if Nkind (Unit (Cunit (New_Unit))) = N_Subunit then
8161 Redundant := Clause;
8162 Prev_Use := Cur_Use;
8164 -- Most common case: redundant clause in body,
8165 -- original clause in spec. Current scope is spec entity.
8170 Unit (Library_Unit (Cunit (Current_Sem_Unit))))
8172 Redundant := Cur_Use;
8176 -- The new clause may appear in an unrelated unit, when
8177 -- the parents of a generic are being installed prior to
8178 -- instantiation. In this case there must be no warning.
8179 -- We detect this case by checking whether the current top
8180 -- of the stack is related to the current compilation.
8182 Scop := Current_Scope;
8183 while Present (Scop) and then Scop /= Standard_Standard loop
8184 if Is_Compilation_Unit (Scop)
8185 and then not Is_Child_Unit (Scop)
8189 elsif Scop = Cunit_Entity (Current_Sem_Unit) then
8193 Scop := Scope (Scop);
8196 Redundant := Cur_Use;
8200 elsif New_Unit = Current_Sem_Unit then
8201 Redundant := Clause;
8202 Prev_Use := Cur_Use;
8205 -- Neither is the current unit, so they appear in parent or
8206 -- sibling units. Warning will be emitted elsewhere.
8212 elsif Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Declaration
8213 and then Present (Parent_Spec (Unit (Cunit (Current_Sem_Unit))))
8215 -- Use_clause is in child unit of current unit, and the child unit
8216 -- appears in the context of the body of the parent, so it has been
8217 -- installed first, even though it is the redundant one. Depending on
8218 -- their placement in the context, the visible or the private parts
8219 -- of the two units, either might appear as redundant, but the
8220 -- message has to be on the current unit.
8222 if Get_Source_Unit (Cur_Use) = Current_Sem_Unit then
8223 Redundant := Cur_Use;
8226 Redundant := Clause;
8227 Prev_Use := Cur_Use;
8230 -- If the new use clause appears in the private part of a parent unit
8231 -- it may appear to be redundant w.r.t. a use clause in a child unit,
8232 -- but the previous use clause was needed in the visible part of the
8233 -- child, and no warning should be emitted.
8235 if Nkind (Parent (Decl)) = N_Package_Specification
8237 List_Containing (Decl) = Private_Declarations (Parent (Decl))
8240 Par : constant Entity_Id := Defining_Entity (Parent (Decl));
8241 Spec : constant Node_Id :=
8242 Specification (Unit (Cunit (Current_Sem_Unit)));
8245 if Is_Compilation_Unit (Par)
8246 and then Par /= Cunit_Entity (Current_Sem_Unit)
8247 and then Parent (Cur_Use) = Spec
8249 List_Containing (Cur_Use) = Visible_Declarations (Spec)
8256 -- Finally, if the current use clause is in the context then
8257 -- the clause is redundant when it is nested within the unit.
8259 elsif Nkind (Parent (Cur_Use)) = N_Compilation_Unit
8260 and then Nkind (Parent (Parent (Clause))) /= N_Compilation_Unit
8261 and then Get_Source_Unit (Cur_Use) = Get_Source_Unit (Clause)
8263 Redundant := Clause;
8264 Prev_Use := Cur_Use;
8270 if Present (Redundant) then
8271 Error_Msg_Sloc := Sloc (Prev_Use);
8272 Error_Msg_NE -- CODEFIX
8273 ("& is already use-visible through previous use clause #??",
8274 Redundant, Pack_Name);
8276 end Note_Redundant_Use;
8282 procedure Pop_Scope is
8283 SST : Scope_Stack_Entry renames Scope_Stack.Table (Scope_Stack.Last);
8284 S : constant Entity_Id := SST.Entity;
8287 if Debug_Flag_E then
8291 -- Set Default_Storage_Pool field of the library unit if necessary
8293 if Ekind_In (S, E_Package, E_Generic_Package)
8295 Nkind (Parent (Unit_Declaration_Node (S))) = N_Compilation_Unit
8298 Aux : constant Node_Id :=
8299 Aux_Decls_Node (Parent (Unit_Declaration_Node (S)));
8301 if No (Default_Storage_Pool (Aux)) then
8302 Set_Default_Storage_Pool (Aux, Default_Pool);
8307 Scope_Suppress := SST.Save_Scope_Suppress;
8308 Local_Suppress_Stack_Top := SST.Save_Local_Suppress_Stack_Top;
8309 Check_Policy_List := SST.Save_Check_Policy_List;
8310 Default_Pool := SST.Save_Default_Storage_Pool;
8311 No_Tagged_Streams := SST.Save_No_Tagged_Streams;
8312 SPARK_Mode := SST.Save_SPARK_Mode;
8313 SPARK_Mode_Pragma := SST.Save_SPARK_Mode_Pragma;
8314 Default_SSO := SST.Save_Default_SSO;
8315 Uneval_Old := SST.Save_Uneval_Old;
8317 if Debug_Flag_W then
8318 Write_Str ("<-- exiting scope: ");
8319 Write_Name (Chars (Current_Scope));
8320 Write_Str (", Depth=");
8321 Write_Int (Int (Scope_Stack.Last));
8325 End_Use_Clauses (SST.First_Use_Clause);
8327 -- If the actions to be wrapped are still there they will get lost
8328 -- causing incomplete code to be generated. It is better to abort in
8329 -- this case (and we do the abort even with assertions off since the
8330 -- penalty is incorrect code generation).
8332 if SST.Actions_To_Be_Wrapped /= Scope_Actions'(others => No_List) then
8333 raise Program_Error;
8336 -- Free last subprogram name if allocated, and pop scope
8338 Free (SST.Last_Subprogram_Name);
8339 Scope_Stack.Decrement_Last;
8346 procedure Push_Scope (S : Entity_Id) is
8347 E : constant Entity_Id := Scope (S);
8350 if Ekind (S) = E_Void then
8353 -- Set scope depth if not a non-concurrent type, and we have not yet set
8354 -- the scope depth. This means that we have the first occurrence of the
8355 -- scope, and this is where the depth is set.
8357 elsif (not Is_Type (S) or else Is_Concurrent_Type (S))
8358 and then not Scope_Depth_Set (S)
8360 if S = Standard_Standard then
8361 Set_Scope_Depth_Value (S, Uint_0);
8363 elsif Is_Child_Unit (S) then
8364 Set_Scope_Depth_Value (S, Uint_1);
8366 elsif not Is_Record_Type (Current_Scope) then
8367 if Ekind (S) = E_Loop then
8368 Set_Scope_Depth_Value (S, Scope_Depth (Current_Scope));
8370 Set_Scope_Depth_Value (S, Scope_Depth (Current_Scope) + 1);
8375 Scope_Stack.Increment_Last;
8378 SST : Scope_Stack_Entry renames Scope_Stack.Table (Scope_Stack.Last);
8382 SST.Save_Scope_Suppress := Scope_Suppress;
8383 SST.Save_Local_Suppress_Stack_Top := Local_Suppress_Stack_Top;
8384 SST.Save_Check_Policy_List := Check_Policy_List;
8385 SST.Save_Default_Storage_Pool := Default_Pool;
8386 SST.Save_No_Tagged_Streams := No_Tagged_Streams;
8387 SST.Save_SPARK_Mode := SPARK_Mode;
8388 SST.Save_SPARK_Mode_Pragma := SPARK_Mode_Pragma;
8389 SST.Save_Default_SSO := Default_SSO;
8390 SST.Save_Uneval_Old := Uneval_Old;
8392 -- Each new scope pushed onto the scope stack inherits the component
8393 -- alignment of the previous scope. This emulates the "visibility"
8394 -- semantics of pragma Component_Alignment.
8396 if Scope_Stack.Last > Scope_Stack.First then
8397 SST.Component_Alignment_Default :=
8399 (Scope_Stack.Last - 1). Component_Alignment_Default;
8401 -- Otherwise, this is the first scope being pushed on the scope
8402 -- stack. Inherit the component alignment from the configuration
8403 -- form of pragma Component_Alignment (if any).
8406 SST.Component_Alignment_Default :=
8407 Configuration_Component_Alignment;
8410 SST.Last_Subprogram_Name := null;
8411 SST.Is_Transient := False;
8412 SST.Node_To_Be_Wrapped := Empty;
8413 SST.Pending_Freeze_Actions := No_List;
8414 SST.Actions_To_Be_Wrapped := (others => No_List);
8415 SST.First_Use_Clause := Empty;
8416 SST.Is_Active_Stack_Base := False;
8417 SST.Previous_Visibility := False;
8418 SST.Locked_Shared_Objects := No_Elist;
8421 if Debug_Flag_W then
8422 Write_Str ("--> new scope: ");
8423 Write_Name (Chars (Current_Scope));
8424 Write_Str (", Id=");
8425 Write_Int (Int (Current_Scope));
8426 Write_Str (", Depth=");
8427 Write_Int (Int (Scope_Stack.Last));
8431 -- Deal with copying flags from the previous scope to this one. This is
8432 -- not necessary if either scope is standard, or if the new scope is a
8435 if S /= Standard_Standard
8436 and then Scope (S) /= Standard_Standard
8437 and then not Is_Child_Unit (S)
8439 if Nkind (E) not in N_Entity then
8443 -- Copy categorization flags from Scope (S) to S, this is not done
8444 -- when Scope (S) is Standard_Standard since propagation is from
8445 -- library unit entity inwards. Copy other relevant attributes as
8446 -- well (Discard_Names in particular).
8448 -- We only propagate inwards for library level entities,
8449 -- inner level subprograms do not inherit the categorization.
8451 if Is_Library_Level_Entity (S) then
8452 Set_Is_Preelaborated (S, Is_Preelaborated (E));
8453 Set_Is_Shared_Passive (S, Is_Shared_Passive (E));
8454 Set_Discard_Names (S, Discard_Names (E));
8455 Set_Suppress_Value_Tracking_On_Call
8456 (S, Suppress_Value_Tracking_On_Call (E));
8457 Set_Categorization_From_Scope (E => S, Scop => E);
8461 if Is_Child_Unit (S)
8462 and then Present (E)
8463 and then Ekind_In (E, E_Package, E_Generic_Package)
8465 Nkind (Parent (Unit_Declaration_Node (E))) = N_Compilation_Unit
8468 Aux : constant Node_Id :=
8469 Aux_Decls_Node (Parent (Unit_Declaration_Node (E)));
8471 if Present (Default_Storage_Pool (Aux)) then
8472 Default_Pool := Default_Storage_Pool (Aux);
8478 ---------------------
8479 -- Premature_Usage --
8480 ---------------------
8482 procedure Premature_Usage (N : Node_Id) is
8483 Kind : constant Node_Kind := Nkind (Parent (Entity (N)));
8484 E : Entity_Id := Entity (N);
8487 -- Within an instance, the analysis of the actual for a formal object
8488 -- does not see the name of the object itself. This is significant only
8489 -- if the object is an aggregate, where its analysis does not do any
8490 -- name resolution on component associations. (see 4717-008). In such a
8491 -- case, look for the visible homonym on the chain.
8493 if In_Instance and then Present (Homonym (E)) then
8495 while Present (E) and then not In_Open_Scopes (Scope (E)) loop
8501 Set_Etype (N, Etype (E));
8506 if Kind = N_Component_Declaration then
8508 ("component&! cannot be used before end of record declaration", N);
8510 elsif Kind = N_Parameter_Specification then
8512 ("formal parameter&! cannot be used before end of specification",
8515 elsif Kind = N_Discriminant_Specification then
8517 ("discriminant&! cannot be used before end of discriminant part",
8520 elsif Kind = N_Procedure_Specification
8521 or else Kind = N_Function_Specification
8524 ("subprogram&! cannot be used before end of its declaration",
8527 elsif Kind = N_Full_Type_Declaration then
8529 ("type& cannot be used before end of its declaration!", N);
8533 ("object& cannot be used before end of its declaration!", N);
8535 end Premature_Usage;
8537 ------------------------
8538 -- Present_System_Aux --
8539 ------------------------
8541 function Present_System_Aux (N : Node_Id := Empty) return Boolean is
8543 Aux_Name : Unit_Name_Type;
8544 Unum : Unit_Number_Type;
8549 function Find_System (C_Unit : Node_Id) return Entity_Id;
8550 -- Scan context clause of compilation unit to find with_clause
8557 function Find_System (C_Unit : Node_Id) return Entity_Id is
8558 With_Clause : Node_Id;
8561 With_Clause := First (Context_Items (C_Unit));
8562 while Present (With_Clause) loop
8563 if (Nkind (With_Clause) = N_With_Clause
8564 and then Chars (Name (With_Clause)) = Name_System)
8565 and then Comes_From_Source (With_Clause)
8576 -- Start of processing for Present_System_Aux
8579 -- The child unit may have been loaded and analyzed already
8581 if Present (System_Aux_Id) then
8584 -- If no previous pragma for System.Aux, nothing to load
8586 elsif No (System_Extend_Unit) then
8589 -- Use the unit name given in the pragma to retrieve the unit.
8590 -- Verify that System itself appears in the context clause of the
8591 -- current compilation. If System is not present, an error will
8592 -- have been reported already.
8595 With_Sys := Find_System (Cunit (Current_Sem_Unit));
8597 The_Unit := Unit (Cunit (Current_Sem_Unit));
8601 (Nkind (The_Unit) = N_Package_Body
8602 or else (Nkind (The_Unit) = N_Subprogram_Body
8603 and then not Acts_As_Spec (Cunit (Current_Sem_Unit))))
8605 With_Sys := Find_System (Library_Unit (Cunit (Current_Sem_Unit)));
8608 if No (With_Sys) and then Present (N) then
8610 -- If we are compiling a subunit, we need to examine its
8611 -- context as well (Current_Sem_Unit is the parent unit);
8613 The_Unit := Parent (N);
8614 while Nkind (The_Unit) /= N_Compilation_Unit loop
8615 The_Unit := Parent (The_Unit);
8618 if Nkind (Unit (The_Unit)) = N_Subunit then
8619 With_Sys := Find_System (The_Unit);
8623 if No (With_Sys) then
8627 Loc := Sloc (With_Sys);
8628 Get_Name_String (Chars (Expression (System_Extend_Unit)));
8629 Name_Buffer (8 .. Name_Len + 7) := Name_Buffer (1 .. Name_Len);
8630 Name_Buffer (1 .. 7) := "system.";
8631 Name_Buffer (Name_Len + 8) := '%';
8632 Name_Buffer (Name_Len + 9) := 's';
8633 Name_Len := Name_Len + 9;
8634 Aux_Name := Name_Find;
8638 (Load_Name => Aux_Name,
8641 Error_Node => With_Sys);
8643 if Unum /= No_Unit then
8644 Semantics (Cunit (Unum));
8646 Defining_Entity (Specification (Unit (Cunit (Unum))));
8649 Make_With_Clause (Loc,
8651 Make_Expanded_Name (Loc,
8652 Chars => Chars (System_Aux_Id),
8653 Prefix => New_Occurrence_Of (Scope (System_Aux_Id), Loc),
8654 Selector_Name => New_Occurrence_Of (System_Aux_Id, Loc)));
8656 Set_Entity (Name (Withn), System_Aux_Id);
8658 Set_Library_Unit (Withn, Cunit (Unum));
8659 Set_Corresponding_Spec (Withn, System_Aux_Id);
8660 Set_First_Name (Withn, True);
8661 Set_Implicit_With (Withn, True);
8663 Insert_After (With_Sys, Withn);
8664 Mark_Rewrite_Insertion (Withn);
8665 Set_Context_Installed (Withn);
8669 -- Here if unit load failed
8672 Error_Msg_Name_1 := Name_System;
8673 Error_Msg_Name_2 := Chars (Expression (System_Extend_Unit));
8675 ("extension package `%.%` does not exist",
8676 Opt.System_Extend_Unit);
8680 end Present_System_Aux;
8682 -------------------------
8683 -- Restore_Scope_Stack --
8684 -------------------------
8686 procedure Restore_Scope_Stack
8688 Handle_Use : Boolean := True)
8690 SS_Last : constant Int := Scope_Stack.Last;
8694 -- Restore visibility of previous scope stack, if any, using the list
8695 -- we saved (we use Remove, since this list will not be used again).
8698 Elmt := Last_Elmt (List);
8699 exit when Elmt = No_Elmt;
8700 Set_Is_Immediately_Visible (Node (Elmt));
8701 Remove_Last_Elmt (List);
8704 -- Restore use clauses
8706 if SS_Last >= Scope_Stack.First
8707 and then Scope_Stack.Table (SS_Last).Entity /= Standard_Standard
8710 Install_Use_Clauses (Scope_Stack.Table (SS_Last).First_Use_Clause);
8712 end Restore_Scope_Stack;
8714 ----------------------
8715 -- Save_Scope_Stack --
8716 ----------------------
8718 -- Save_Scope_Stack/Restore_Scope_Stack were originally designed to avoid
8719 -- consuming any memory. That is, Save_Scope_Stack took care of removing
8720 -- from immediate visibility entities and Restore_Scope_Stack took care
8721 -- of restoring their visibility analyzing the context of each entity. The
8722 -- problem of such approach is that it was fragile and caused unexpected
8723 -- visibility problems, and indeed one test was found where there was a
8726 -- Furthermore, the following experiment was carried out:
8728 -- - Save_Scope_Stack was modified to store in an Elist1 all those
8729 -- entities whose attribute Is_Immediately_Visible is modified
8730 -- from True to False.
8732 -- - Restore_Scope_Stack was modified to store in another Elist2
8733 -- all the entities whose attribute Is_Immediately_Visible is
8734 -- modified from False to True.
8736 -- - Extra code was added to verify that all the elements of Elist1
8737 -- are found in Elist2
8739 -- This test shows that there may be more occurrences of this problem which
8740 -- have not yet been detected. As a result, we replaced that approach by
8741 -- the current one in which Save_Scope_Stack returns the list of entities
8742 -- whose visibility is changed, and that list is passed to Restore_Scope_
8743 -- Stack to undo that change. This approach is simpler and safer, although
8744 -- it consumes more memory.
8746 function Save_Scope_Stack (Handle_Use : Boolean := True) return Elist_Id is
8747 Result : constant Elist_Id := New_Elmt_List;
8750 SS_Last : constant Int := Scope_Stack.Last;
8752 procedure Remove_From_Visibility (E : Entity_Id);
8753 -- If E is immediately visible then append it to the result and remove
8754 -- it temporarily from visibility.
8756 ----------------------------
8757 -- Remove_From_Visibility --
8758 ----------------------------
8760 procedure Remove_From_Visibility (E : Entity_Id) is
8762 if Is_Immediately_Visible (E) then
8763 Append_Elmt (E, Result);
8764 Set_Is_Immediately_Visible (E, False);
8766 end Remove_From_Visibility;
8768 -- Start of processing for Save_Scope_Stack
8771 if SS_Last >= Scope_Stack.First
8772 and then Scope_Stack.Table (SS_Last).Entity /= Standard_Standard
8775 End_Use_Clauses (Scope_Stack.Table (SS_Last).First_Use_Clause);
8778 -- If the call is from within a compilation unit, as when called from
8779 -- Rtsfind, make current entries in scope stack invisible while we
8780 -- analyze the new unit.
8782 for J in reverse 0 .. SS_Last loop
8783 exit when Scope_Stack.Table (J).Entity = Standard_Standard
8784 or else No (Scope_Stack.Table (J).Entity);
8786 S := Scope_Stack.Table (J).Entity;
8788 Remove_From_Visibility (S);
8790 E := First_Entity (S);
8791 while Present (E) loop
8792 Remove_From_Visibility (E);
8800 end Save_Scope_Stack;
8806 procedure Set_Use (L : List_Id) is
8808 Pack_Name : Node_Id;
8815 while Present (Decl) loop
8816 if Nkind (Decl) = N_Use_Package_Clause then
8817 Chain_Use_Clause (Decl);
8819 Pack_Name := First (Names (Decl));
8820 while Present (Pack_Name) loop
8821 Pack := Entity (Pack_Name);
8823 if Ekind (Pack) = E_Package
8824 and then Applicable_Use (Pack_Name)
8826 Use_One_Package (Pack, Decl);
8832 elsif Nkind (Decl) = N_Use_Type_Clause then
8833 Chain_Use_Clause (Decl);
8835 Id := First (Subtype_Marks (Decl));
8836 while Present (Id) loop
8837 if Entity (Id) /= Any_Type then
8850 ---------------------
8851 -- Use_One_Package --
8852 ---------------------
8854 procedure Use_One_Package (P : Entity_Id; N : Node_Id) is
8857 Current_Instance : Entity_Id := Empty;
8859 Private_With_OK : Boolean := False;
8862 if Ekind (P) /= E_Package then
8867 Set_Current_Use_Clause (P, N);
8869 -- Ada 2005 (AI-50217): Check restriction
8871 if From_Limited_With (P) then
8872 Error_Msg_N ("limited withed package cannot appear in use clause", N);
8875 -- Find enclosing instance, if any
8878 Current_Instance := Current_Scope;
8879 while not Is_Generic_Instance (Current_Instance) loop
8880 Current_Instance := Scope (Current_Instance);
8883 if No (Hidden_By_Use_Clause (N)) then
8884 Set_Hidden_By_Use_Clause (N, New_Elmt_List);
8888 -- If unit is a package renaming, indicate that the renamed
8889 -- package is also in use (the flags on both entities must
8890 -- remain consistent, and a subsequent use of either of them
8891 -- should be recognized as redundant).
8893 if Present (Renamed_Object (P)) then
8894 Set_In_Use (Renamed_Object (P));
8895 Set_Current_Use_Clause (Renamed_Object (P), N);
8896 Real_P := Renamed_Object (P);
8901 -- Ada 2005 (AI-262): Check the use_clause of a private withed package
8902 -- found in the private part of a package specification
8904 if In_Private_Part (Current_Scope)
8905 and then Has_Private_With (P)
8906 and then Is_Child_Unit (Current_Scope)
8907 and then Is_Child_Unit (P)
8908 and then Is_Ancestor_Package (Scope (Current_Scope), P)
8910 Private_With_OK := True;
8913 -- Loop through entities in one package making them potentially
8916 Id := First_Entity (P);
8918 and then (Id /= First_Private_Entity (P)
8919 or else Private_With_OK) -- Ada 2005 (AI-262)
8921 Prev := Current_Entity (Id);
8922 while Present (Prev) loop
8923 if Is_Immediately_Visible (Prev)
8924 and then (not Is_Overloadable (Prev)
8925 or else not Is_Overloadable (Id)
8926 or else (Type_Conformant (Id, Prev)))
8928 if No (Current_Instance) then
8930 -- Potentially use-visible entity remains hidden
8932 goto Next_Usable_Entity;
8934 -- A use clause within an instance hides outer global entities,
8935 -- which are not used to resolve local entities in the
8936 -- instance. Note that the predefined entities in Standard
8937 -- could not have been hidden in the generic by a use clause,
8938 -- and therefore remain visible. Other compilation units whose
8939 -- entities appear in Standard must be hidden in an instance.
8941 -- To determine whether an entity is external to the instance
8942 -- we compare the scope depth of its scope with that of the
8943 -- current instance. However, a generic actual of a subprogram
8944 -- instance is declared in the wrapper package but will not be
8945 -- hidden by a use-visible entity. similarly, an entity that is
8946 -- declared in an enclosing instance will not be hidden by an
8947 -- an entity declared in a generic actual, which can only have
8948 -- been use-visible in the generic and will not have hidden the
8949 -- entity in the generic parent.
8951 -- If Id is called Standard, the predefined package with the
8952 -- same name is in the homonym chain. It has to be ignored
8953 -- because it has no defined scope (being the only entity in
8954 -- the system with this mandated behavior).
8956 elsif not Is_Hidden (Id)
8957 and then Present (Scope (Prev))
8958 and then not Is_Wrapper_Package (Scope (Prev))
8959 and then Scope_Depth (Scope (Prev)) <
8960 Scope_Depth (Current_Instance)
8961 and then (Scope (Prev) /= Standard_Standard
8962 or else Sloc (Prev) > Standard_Location)
8964 if In_Open_Scopes (Scope (Prev))
8965 and then Is_Generic_Instance (Scope (Prev))
8966 and then Present (Associated_Formal_Package (P))
8971 Set_Is_Potentially_Use_Visible (Id);
8972 Set_Is_Immediately_Visible (Prev, False);
8973 Append_Elmt (Prev, Hidden_By_Use_Clause (N));
8977 -- A user-defined operator is not use-visible if the predefined
8978 -- operator for the type is immediately visible, which is the case
8979 -- if the type of the operand is in an open scope. This does not
8980 -- apply to user-defined operators that have operands of different
8981 -- types, because the predefined mixed mode operations (multiply
8982 -- and divide) apply to universal types and do not hide anything.
8984 elsif Ekind (Prev) = E_Operator
8985 and then Operator_Matches_Spec (Prev, Id)
8986 and then In_Open_Scopes
8987 (Scope (Base_Type (Etype (First_Formal (Id)))))
8988 and then (No (Next_Formal (First_Formal (Id)))
8989 or else Etype (First_Formal (Id)) =
8990 Etype (Next_Formal (First_Formal (Id)))
8991 or else Chars (Prev) = Name_Op_Expon)
8993 goto Next_Usable_Entity;
8995 -- In an instance, two homonyms may become use_visible through the
8996 -- actuals of distinct formal packages. In the generic, only the
8997 -- current one would have been visible, so make the other one
9000 elsif Present (Current_Instance)
9001 and then Is_Potentially_Use_Visible (Prev)
9002 and then not Is_Overloadable (Prev)
9003 and then Scope (Id) /= Scope (Prev)
9004 and then Used_As_Generic_Actual (Scope (Prev))
9005 and then Used_As_Generic_Actual (Scope (Id))
9006 and then not In_Same_List (Current_Use_Clause (Scope (Prev)),
9007 Current_Use_Clause (Scope (Id)))
9009 Set_Is_Potentially_Use_Visible (Prev, False);
9010 Append_Elmt (Prev, Hidden_By_Use_Clause (N));
9013 Prev := Homonym (Prev);
9016 -- On exit, we know entity is not hidden, unless it is private
9018 if not Is_Hidden (Id)
9019 and then ((not Is_Child_Unit (Id)) or else Is_Visible_Lib_Unit (Id))
9021 Set_Is_Potentially_Use_Visible (Id);
9023 if Is_Private_Type (Id) and then Present (Full_View (Id)) then
9024 Set_Is_Potentially_Use_Visible (Full_View (Id));
9028 <<Next_Usable_Entity>>
9032 -- Child units are also made use-visible by a use clause, but they may
9033 -- appear after all visible declarations in the parent entity list.
9035 while Present (Id) loop
9036 if Is_Child_Unit (Id) and then Is_Visible_Lib_Unit (Id) then
9037 Set_Is_Potentially_Use_Visible (Id);
9043 if Chars (Real_P) = Name_System
9044 and then Scope (Real_P) = Standard_Standard
9045 and then Present_System_Aux (N)
9047 Use_One_Package (System_Aux_Id, N);
9050 end Use_One_Package;
9056 procedure Use_One_Type (Id : Node_Id; Installed : Boolean := False) is
9058 Is_Known_Used : Boolean;
9062 function Spec_Reloaded_For_Body return Boolean;
9063 -- Determine whether the compilation unit is a package body and the use
9064 -- type clause is in the spec of the same package. Even though the spec
9065 -- was analyzed first, its context is reloaded when analysing the body.
9067 procedure Use_Class_Wide_Operations (Typ : Entity_Id);
9068 -- AI05-150: if the use_type_clause carries the "all" qualifier,
9069 -- class-wide operations of ancestor types are use-visible if the
9070 -- ancestor type is visible.
9072 ----------------------------
9073 -- Spec_Reloaded_For_Body --
9074 ----------------------------
9076 function Spec_Reloaded_For_Body return Boolean is
9078 if Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Body then
9080 Spec : constant Node_Id :=
9081 Parent (List_Containing (Parent (Id)));
9084 -- Check whether type is declared in a package specification,
9085 -- and current unit is the corresponding package body. The
9086 -- use clauses themselves may be within a nested package.
9089 Nkind (Spec) = N_Package_Specification
9091 In_Same_Source_Unit (Corresponding_Body (Parent (Spec)),
9092 Cunit_Entity (Current_Sem_Unit));
9097 end Spec_Reloaded_For_Body;
9099 -------------------------------
9100 -- Use_Class_Wide_Operations --
9101 -------------------------------
9103 procedure Use_Class_Wide_Operations (Typ : Entity_Id) is
9107 function Is_Class_Wide_Operation_Of
9109 T : Entity_Id) return Boolean;
9110 -- Determine whether a subprogram has a class-wide parameter or
9111 -- result that is T'Class.
9113 ---------------------------------
9114 -- Is_Class_Wide_Operation_Of --
9115 ---------------------------------
9117 function Is_Class_Wide_Operation_Of
9119 T : Entity_Id) return Boolean
9124 Formal := First_Formal (Op);
9125 while Present (Formal) loop
9126 if Etype (Formal) = Class_Wide_Type (T) then
9129 Next_Formal (Formal);
9132 if Etype (Op) = Class_Wide_Type (T) then
9137 end Is_Class_Wide_Operation_Of;
9139 -- Start of processing for Use_Class_Wide_Operations
9142 Scop := Scope (Typ);
9143 if not Is_Hidden (Scop) then
9144 Ent := First_Entity (Scop);
9145 while Present (Ent) loop
9146 if Is_Overloadable (Ent)
9147 and then Is_Class_Wide_Operation_Of (Ent, Typ)
9148 and then not Is_Potentially_Use_Visible (Ent)
9150 Set_Is_Potentially_Use_Visible (Ent);
9151 Append_Elmt (Ent, Used_Operations (Parent (Id)));
9158 if Is_Derived_Type (Typ) then
9159 Use_Class_Wide_Operations (Etype (Base_Type (Typ)));
9161 end Use_Class_Wide_Operations;
9163 -- Start of processing for Use_One_Type
9166 -- It is the type determined by the subtype mark (8.4(8)) whose
9167 -- operations become potentially use-visible.
9169 T := Base_Type (Entity (Id));
9171 -- Either the type itself is used, the package where it is declared
9172 -- is in use or the entity is declared in the current package, thus
9177 or else In_Use (Scope (T))
9178 or else Scope (T) = Current_Scope;
9180 Set_Redundant_Use (Id,
9181 Is_Known_Used or else Is_Potentially_Use_Visible (T));
9183 if Ekind (T) = E_Incomplete_Type then
9184 Error_Msg_N ("premature usage of incomplete type", Id);
9186 elsif In_Open_Scopes (Scope (T)) then
9189 -- A limited view cannot appear in a use_type clause. However, an access
9190 -- type whose designated type is limited has the flag but is not itself
9191 -- a limited view unless we only have a limited view of its enclosing
9194 elsif From_Limited_With (T) and then From_Limited_With (Scope (T)) then
9196 ("incomplete type from limited view "
9197 & "cannot appear in use clause", Id);
9199 -- If the subtype mark designates a subtype in a different package,
9200 -- we have to check that the parent type is visible, otherwise the
9201 -- use type clause is a noop. Not clear how to do that???
9203 elsif not Redundant_Use (Id) then
9206 -- If T is tagged, primitive operators on class-wide operands
9207 -- are also available.
9209 if Is_Tagged_Type (T) then
9210 Set_In_Use (Class_Wide_Type (T));
9213 Set_Current_Use_Clause (T, Parent (Id));
9215 -- Iterate over primitive operations of the type. If an operation is
9216 -- already use_visible, it is the result of a previous use_clause,
9217 -- and already appears on the corresponding entity chain. If the
9218 -- clause is being reinstalled, operations are already use-visible.
9224 Op_List := Collect_Primitive_Operations (T);
9225 Elmt := First_Elmt (Op_List);
9226 while Present (Elmt) loop
9227 if (Nkind (Node (Elmt)) = N_Defining_Operator_Symbol
9228 or else Chars (Node (Elmt)) in Any_Operator_Name)
9229 and then not Is_Hidden (Node (Elmt))
9230 and then not Is_Potentially_Use_Visible (Node (Elmt))
9232 Set_Is_Potentially_Use_Visible (Node (Elmt));
9233 Append_Elmt (Node (Elmt), Used_Operations (Parent (Id)));
9235 elsif Ada_Version >= Ada_2012
9236 and then All_Present (Parent (Id))
9237 and then not Is_Hidden (Node (Elmt))
9238 and then not Is_Potentially_Use_Visible (Node (Elmt))
9240 Set_Is_Potentially_Use_Visible (Node (Elmt));
9241 Append_Elmt (Node (Elmt), Used_Operations (Parent (Id)));
9248 if Ada_Version >= Ada_2012
9249 and then All_Present (Parent (Id))
9250 and then Is_Tagged_Type (T)
9252 Use_Class_Wide_Operations (T);
9256 -- If warning on redundant constructs, check for unnecessary WITH
9258 if Warn_On_Redundant_Constructs
9259 and then Is_Known_Used
9261 -- with P; with P; use P;
9262 -- package P is package X is package body X is
9263 -- type T ... use P.T;
9265 -- The compilation unit is the body of X. GNAT first compiles the
9266 -- spec of X, then proceeds to the body. At that point P is marked
9267 -- as use visible. The analysis then reinstalls the spec along with
9268 -- its context. The use clause P.T is now recognized as redundant,
9269 -- but in the wrong context. Do not emit a warning in such cases.
9270 -- Do not emit a warning either if we are in an instance, there is
9271 -- no redundancy between an outer use_clause and one that appears
9272 -- within the generic.
9274 and then not Spec_Reloaded_For_Body
9275 and then not In_Instance
9277 -- The type already has a use clause
9281 -- Case where we know the current use clause for the type
9283 if Present (Current_Use_Clause (T)) then
9284 Use_Clause_Known : declare
9285 Clause1 : constant Node_Id := Parent (Id);
9286 Clause2 : constant Node_Id := Current_Use_Clause (T);
9293 function Entity_Of_Unit (U : Node_Id) return Entity_Id;
9294 -- Return the appropriate entity for determining which unit
9295 -- has a deeper scope: the defining entity for U, unless U
9296 -- is a package instance, in which case we retrieve the
9297 -- entity of the instance spec.
9299 --------------------
9300 -- Entity_Of_Unit --
9301 --------------------
9303 function Entity_Of_Unit (U : Node_Id) return Entity_Id is
9305 if Nkind (U) = N_Package_Instantiation
9306 and then Analyzed (U)
9308 return Defining_Entity (Instance_Spec (U));
9310 return Defining_Entity (U);
9314 -- Start of processing for Use_Clause_Known
9317 -- If both current use type clause and the use type clause
9318 -- for the type are at the compilation unit level, one of
9319 -- the units must be an ancestor of the other, and the
9320 -- warning belongs on the descendant.
9322 if Nkind (Parent (Clause1)) = N_Compilation_Unit
9324 Nkind (Parent (Clause2)) = N_Compilation_Unit
9326 -- If the unit is a subprogram body that acts as spec,
9327 -- the context clause is shared with the constructed
9328 -- subprogram spec. Clearly there is no redundancy.
9330 if Clause1 = Clause2 then
9334 Unit1 := Unit (Parent (Clause1));
9335 Unit2 := Unit (Parent (Clause2));
9337 -- If both clauses are on same unit, or one is the body
9338 -- of the other, or one of them is in a subunit, report
9339 -- redundancy on the later one.
9341 if Unit1 = Unit2 then
9342 Error_Msg_Sloc := Sloc (Current_Use_Clause (T));
9343 Error_Msg_NE -- CODEFIX
9344 ("& is already use-visible through previous "
9345 & "use_type_clause #??", Clause1, T);
9348 elsif Nkind (Unit1) = N_Subunit then
9349 Error_Msg_Sloc := Sloc (Current_Use_Clause (T));
9350 Error_Msg_NE -- CODEFIX
9351 ("& is already use-visible through previous "
9352 & "use_type_clause #??", Clause1, T);
9355 elsif Nkind_In (Unit2, N_Package_Body, N_Subprogram_Body)
9356 and then Nkind (Unit1) /= Nkind (Unit2)
9357 and then Nkind (Unit1) /= N_Subunit
9359 Error_Msg_Sloc := Sloc (Clause1);
9360 Error_Msg_NE -- CODEFIX
9361 ("& is already use-visible through previous "
9362 & "use_type_clause #??", Current_Use_Clause (T), T);
9366 -- There is a redundant use type clause in a child unit.
9367 -- Determine which of the units is more deeply nested.
9368 -- If a unit is a package instance, retrieve the entity
9369 -- and its scope from the instance spec.
9371 Ent1 := Entity_Of_Unit (Unit1);
9372 Ent2 := Entity_Of_Unit (Unit2);
9374 if Scope (Ent2) = Standard_Standard then
9375 Error_Msg_Sloc := Sloc (Current_Use_Clause (T));
9378 elsif Scope (Ent1) = Standard_Standard then
9379 Error_Msg_Sloc := Sloc (Id);
9382 -- If both units are child units, we determine which one
9383 -- is the descendant by the scope distance to the
9384 -- ultimate parent unit.
9394 and then Present (S2)
9395 and then S1 /= Standard_Standard
9396 and then S2 /= Standard_Standard
9402 if S1 = Standard_Standard then
9403 Error_Msg_Sloc := Sloc (Id);
9406 Error_Msg_Sloc := Sloc (Current_Use_Clause (T));
9412 Error_Msg_NE -- CODEFIX
9413 ("& is already use-visible through previous "
9414 & "use_type_clause #??", Err_No, Id);
9416 -- Case where current use type clause and the use type
9417 -- clause for the type are not both at the compilation unit
9418 -- level. In this case we don't have location information.
9421 Error_Msg_NE -- CODEFIX
9422 ("& is already use-visible through previous "
9423 & "use type clause??", Id, T);
9425 end Use_Clause_Known;
9427 -- Here if Current_Use_Clause is not set for T, another case
9428 -- where we do not have the location information available.
9431 Error_Msg_NE -- CODEFIX
9432 ("& is already use-visible through previous "
9433 & "use type clause??", Id, T);
9436 -- The package where T is declared is already used
9438 elsif In_Use (Scope (T)) then
9439 Error_Msg_Sloc := Sloc (Current_Use_Clause (Scope (T)));
9440 Error_Msg_NE -- CODEFIX
9441 ("& is already use-visible through package use clause #??",
9444 -- The current scope is the package where T is declared
9447 Error_Msg_Node_2 := Scope (T);
9448 Error_Msg_NE -- CODEFIX
9449 ("& is already use-visible inside package &??", Id, T);
9458 procedure Write_Info is
9459 Id : Entity_Id := First_Entity (Current_Scope);
9462 -- No point in dumping standard entities
9464 if Current_Scope = Standard_Standard then
9468 Write_Str ("========================================================");
9470 Write_Str (" Defined Entities in ");
9471 Write_Name (Chars (Current_Scope));
9473 Write_Str ("========================================================");
9477 Write_Str ("-- none --");
9481 while Present (Id) loop
9482 Write_Entity_Info (Id, " ");
9487 if Scope (Current_Scope) = Standard_Standard then
9489 -- Print information on the current unit itself
9491 Write_Entity_Info (Current_Scope, " ");
9504 for J in reverse 1 .. Scope_Stack.Last loop
9505 S := Scope_Stack.Table (J).Entity;
9506 Write_Int (Int (S));
9507 Write_Str (" === ");
9508 Write_Name (Chars (S));
9517 procedure we (S : Entity_Id) is
9520 E := First_Entity (S);
9521 while Present (E) loop
9522 Write_Int (Int (E));
9523 Write_Str (" === ");
9524 Write_Name (Chars (E));