2014-03-25 Richard Biener <rguenther@suse.de>
[official-gcc.git] / gcc / ada / sem_ch4.adb
blobb3da4adf9da0c9a740c20bbee058d2cd061bf7fa
1 ------------------------------------------------------------------------------
2 -- --
3 -- GNAT COMPILER COMPONENTS --
4 -- --
5 -- S E M _ C H 4 --
6 -- --
7 -- B o d y --
8 -- --
9 -- Copyright (C) 1992-2014, Free Software Foundation, Inc. --
10 -- --
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. --
20 -- --
21 -- GNAT was originally developed by the GNAT team at New York University. --
22 -- Extensive contributions were provided by Ada Core Technologies Inc. --
23 -- --
24 ------------------------------------------------------------------------------
26 with Aspects; use Aspects;
27 with Atree; use Atree;
28 with Debug; use Debug;
29 with Einfo; use Einfo;
30 with Elists; use Elists;
31 with Errout; use Errout;
32 with Exp_Util; use Exp_Util;
33 with Fname; use Fname;
34 with Itypes; use Itypes;
35 with Lib; use Lib;
36 with Lib.Xref; use Lib.Xref;
37 with Namet; use Namet;
38 with Namet.Sp; use Namet.Sp;
39 with Nlists; use Nlists;
40 with Nmake; use Nmake;
41 with Opt; use Opt;
42 with Output; use Output;
43 with Restrict; use Restrict;
44 with Rident; use Rident;
45 with Sem; use Sem;
46 with Sem_Aux; use Sem_Aux;
47 with Sem_Case; use Sem_Case;
48 with Sem_Cat; use Sem_Cat;
49 with Sem_Ch3; use Sem_Ch3;
50 with Sem_Ch6; use Sem_Ch6;
51 with Sem_Ch8; use Sem_Ch8;
52 with Sem_Dim; use Sem_Dim;
53 with Sem_Disp; use Sem_Disp;
54 with Sem_Dist; use Sem_Dist;
55 with Sem_Eval; use Sem_Eval;
56 with Sem_Res; use Sem_Res;
57 with Sem_Type; use Sem_Type;
58 with Sem_Util; use Sem_Util;
59 with Sem_Warn; use Sem_Warn;
60 with Stand; use Stand;
61 with Sinfo; use Sinfo;
62 with Snames; use Snames;
63 with Tbuild; use Tbuild;
64 with Uintp; use Uintp;
66 package body Sem_Ch4 is
68 -----------------------
69 -- Local Subprograms --
70 -----------------------
72 procedure Analyze_Concatenation_Rest (N : Node_Id);
73 -- Does the "rest" of the work of Analyze_Concatenation, after the left
74 -- operand has been analyzed. See Analyze_Concatenation for details.
76 procedure Analyze_Expression (N : Node_Id);
77 -- For expressions that are not names, this is just a call to analyze.
78 -- If the expression is a name, it may be a call to a parameterless
79 -- function, and if so must be converted into an explicit call node
80 -- and analyzed as such. This deproceduring must be done during the first
81 -- pass of overload resolution, because otherwise a procedure call with
82 -- overloaded actuals may fail to resolve.
84 procedure Analyze_Operator_Call (N : Node_Id; Op_Id : Entity_Id);
85 -- Analyze a call of the form "+"(x, y), etc. The prefix of the call
86 -- is an operator name or an expanded name whose selector is an operator
87 -- name, and one possible interpretation is as a predefined operator.
89 procedure Analyze_Overloaded_Selected_Component (N : Node_Id);
90 -- If the prefix of a selected_component is overloaded, the proper
91 -- interpretation that yields a record type with the proper selector
92 -- name must be selected.
94 procedure Analyze_User_Defined_Binary_Op (N : Node_Id; Op_Id : Entity_Id);
95 -- Procedure to analyze a user defined binary operator, which is resolved
96 -- like a function, but instead of a list of actuals it is presented
97 -- with the left and right operands of an operator node.
99 procedure Analyze_User_Defined_Unary_Op (N : Node_Id; Op_Id : Entity_Id);
100 -- Procedure to analyze a user defined unary operator, which is resolved
101 -- like a function, but instead of a list of actuals, it is presented with
102 -- the operand of the operator node.
104 procedure Ambiguous_Operands (N : Node_Id);
105 -- For equality, membership, and comparison operators with overloaded
106 -- arguments, list possible interpretations.
108 procedure Analyze_One_Call
109 (N : Node_Id;
110 Nam : Entity_Id;
111 Report : Boolean;
112 Success : out Boolean;
113 Skip_First : Boolean := False);
114 -- Check one interpretation of an overloaded subprogram name for
115 -- compatibility with the types of the actuals in a call. If there is a
116 -- single interpretation which does not match, post error if Report is
117 -- set to True.
119 -- Nam is the entity that provides the formals against which the actuals
120 -- are checked. Nam is either the name of a subprogram, or the internal
121 -- subprogram type constructed for an access_to_subprogram. If the actuals
122 -- are compatible with Nam, then Nam is added to the list of candidate
123 -- interpretations for N, and Success is set to True.
125 -- The flag Skip_First is used when analyzing a call that was rewritten
126 -- from object notation. In this case the first actual may have to receive
127 -- an explicit dereference, depending on the first formal of the operation
128 -- being called. The caller will have verified that the object is legal
129 -- for the call. If the remaining parameters match, the first parameter
130 -- will rewritten as a dereference if needed, prior to completing analysis.
132 procedure Check_Misspelled_Selector
133 (Prefix : Entity_Id;
134 Sel : Node_Id);
135 -- Give possible misspelling diagnostic if Sel is likely to be a mis-
136 -- spelling of one of the selectors of the Prefix. This is called by
137 -- Analyze_Selected_Component after producing an invalid selector error
138 -- message.
140 function Defined_In_Scope (T : Entity_Id; S : Entity_Id) return Boolean;
141 -- Verify that type T is declared in scope S. Used to find interpretations
142 -- for operators given by expanded names. This is abstracted as a separate
143 -- function to handle extensions to System, where S is System, but T is
144 -- declared in the extension.
146 procedure Find_Arithmetic_Types
147 (L, R : Node_Id;
148 Op_Id : Entity_Id;
149 N : Node_Id);
150 -- L and R are the operands of an arithmetic operator. Find
151 -- consistent pairs of interpretations for L and R that have a
152 -- numeric type consistent with the semantics of the operator.
154 procedure Find_Comparison_Types
155 (L, R : Node_Id;
156 Op_Id : Entity_Id;
157 N : Node_Id);
158 -- L and R are operands of a comparison operator. Find consistent
159 -- pairs of interpretations for L and R.
161 procedure Find_Concatenation_Types
162 (L, R : Node_Id;
163 Op_Id : Entity_Id;
164 N : Node_Id);
165 -- For the four varieties of concatenation
167 procedure Find_Equality_Types
168 (L, R : Node_Id;
169 Op_Id : Entity_Id;
170 N : Node_Id);
171 -- Ditto for equality operators
173 procedure Find_Boolean_Types
174 (L, R : Node_Id;
175 Op_Id : Entity_Id;
176 N : Node_Id);
177 -- Ditto for binary logical operations
179 procedure Find_Negation_Types
180 (R : Node_Id;
181 Op_Id : Entity_Id;
182 N : Node_Id);
183 -- Find consistent interpretation for operand of negation operator
185 procedure Find_Non_Universal_Interpretations
186 (N : Node_Id;
187 R : Node_Id;
188 Op_Id : Entity_Id;
189 T1 : Entity_Id);
190 -- For equality and comparison operators, the result is always boolean,
191 -- and the legality of the operation is determined from the visibility
192 -- of the operand types. If one of the operands has a universal interpre-
193 -- tation, the legality check uses some compatible non-universal
194 -- interpretation of the other operand. N can be an operator node, or
195 -- a function call whose name is an operator designator. Any_Access, which
196 -- is the initial type of the literal NULL, is a universal type for the
197 -- purpose of this routine.
199 function Find_Primitive_Operation (N : Node_Id) return Boolean;
200 -- Find candidate interpretations for the name Obj.Proc when it appears
201 -- in a subprogram renaming declaration.
203 procedure Find_Unary_Types
204 (R : Node_Id;
205 Op_Id : Entity_Id;
206 N : Node_Id);
207 -- Unary arithmetic types: plus, minus, abs
209 procedure Check_Arithmetic_Pair
210 (T1, T2 : Entity_Id;
211 Op_Id : Entity_Id;
212 N : Node_Id);
213 -- Subsidiary procedure to Find_Arithmetic_Types. T1 and T2 are valid
214 -- types for left and right operand. Determine whether they constitute
215 -- a valid pair for the given operator, and record the corresponding
216 -- interpretation of the operator node. The node N may be an operator
217 -- node (the usual case) or a function call whose prefix is an operator
218 -- designator. In both cases Op_Id is the operator name itself.
220 procedure Diagnose_Call (N : Node_Id; Nam : Node_Id);
221 -- Give detailed information on overloaded call where none of the
222 -- interpretations match. N is the call node, Nam the designator for
223 -- the overloaded entity being called.
225 function Junk_Operand (N : Node_Id) return Boolean;
226 -- Test for an operand that is an inappropriate entity (e.g. a package
227 -- name or a label). If so, issue an error message and return True. If
228 -- the operand is not an inappropriate entity kind, return False.
230 procedure Operator_Check (N : Node_Id);
231 -- Verify that an operator has received some valid interpretation. If none
232 -- was found, determine whether a use clause would make the operation
233 -- legal. The variable Candidate_Type (defined in Sem_Type) is set for
234 -- every type compatible with the operator, even if the operator for the
235 -- type is not directly visible. The routine uses this type to emit a more
236 -- informative message.
238 function Process_Implicit_Dereference_Prefix
239 (E : Entity_Id;
240 P : Node_Id) return Entity_Id;
241 -- Called when P is the prefix of an implicit dereference, denoting an
242 -- object E. The function returns the designated type of the prefix, taking
243 -- into account that the designated type of an anonymous access type may be
244 -- a limited view, when the non-limited view is visible.
245 -- If in semantics only mode (-gnatc or generic), the function also records
246 -- that the prefix is a reference to E, if any. Normally, such a reference
247 -- is generated only when the implicit dereference is expanded into an
248 -- explicit one, but for consistency we must generate the reference when
249 -- expansion is disabled as well.
251 procedure Remove_Abstract_Operations (N : Node_Id);
252 -- Ada 2005: implementation of AI-310. An abstract non-dispatching
253 -- operation is not a candidate interpretation.
255 function Try_Container_Indexing
256 (N : Node_Id;
257 Prefix : Node_Id;
258 Exprs : List_Id) return Boolean;
259 -- AI05-0139: Generalized indexing to support iterators over containers
261 function Try_Indexed_Call
262 (N : Node_Id;
263 Nam : Entity_Id;
264 Typ : Entity_Id;
265 Skip_First : Boolean) return Boolean;
266 -- If a function has defaults for all its actuals, a call to it may in fact
267 -- be an indexing on the result of the call. Try_Indexed_Call attempts the
268 -- interpretation as an indexing, prior to analysis as a call. If both are
269 -- possible, the node is overloaded with both interpretations (same symbol
270 -- but two different types). If the call is written in prefix form, the
271 -- prefix becomes the first parameter in the call, and only the remaining
272 -- actuals must be checked for the presence of defaults.
274 function Try_Indirect_Call
275 (N : Node_Id;
276 Nam : Entity_Id;
277 Typ : Entity_Id) return Boolean;
278 -- Similarly, a function F that needs no actuals can return an access to a
279 -- subprogram, and the call F (X) interpreted as F.all (X). In this case
280 -- the call may be overloaded with both interpretations.
282 function Try_Object_Operation
283 (N : Node_Id;
284 CW_Test_Only : Boolean := False) return Boolean;
285 -- Ada 2005 (AI-252): Support the object.operation notation. If node N
286 -- is a call in this notation, it is transformed into a normal subprogram
287 -- call where the prefix is a parameter, and True is returned. If node
288 -- N is not of this form, it is unchanged, and False is returned. if
289 -- CW_Test_Only is true then N is an N_Selected_Component node which
290 -- is part of a call to an entry or procedure of a tagged concurrent
291 -- type and this routine is invoked to search for class-wide subprograms
292 -- conflicting with the target entity.
294 procedure wpo (T : Entity_Id);
295 pragma Warnings (Off, wpo);
296 -- Used for debugging: obtain list of primitive operations even if
297 -- type is not frozen and dispatch table is not built yet.
299 ------------------------
300 -- Ambiguous_Operands --
301 ------------------------
303 procedure Ambiguous_Operands (N : Node_Id) is
304 procedure List_Operand_Interps (Opnd : Node_Id);
306 --------------------------
307 -- List_Operand_Interps --
308 --------------------------
310 procedure List_Operand_Interps (Opnd : Node_Id) is
311 Nam : Node_Id;
312 Err : Node_Id := N;
314 begin
315 if Is_Overloaded (Opnd) then
316 if Nkind (Opnd) in N_Op then
317 Nam := Opnd;
318 elsif Nkind (Opnd) = N_Function_Call then
319 Nam := Name (Opnd);
320 elsif Ada_Version >= Ada_2012 then
321 declare
322 It : Interp;
323 I : Interp_Index;
325 begin
326 Get_First_Interp (Opnd, I, It);
327 while Present (It.Nam) loop
328 if Has_Implicit_Dereference (It.Typ) then
329 Error_Msg_N
330 ("can be interpreted as implicit dereference", Opnd);
331 return;
332 end if;
334 Get_Next_Interp (I, It);
335 end loop;
336 end;
338 return;
339 end if;
341 else
342 return;
343 end if;
345 if Opnd = Left_Opnd (N) then
346 Error_Msg_N ("\left operand has the following interpretations", N);
347 else
348 Error_Msg_N
349 ("\right operand has the following interpretations", N);
350 Err := Opnd;
351 end if;
353 List_Interps (Nam, Err);
354 end List_Operand_Interps;
356 -- Start of processing for Ambiguous_Operands
358 begin
359 if Nkind (N) in N_Membership_Test then
360 Error_Msg_N ("ambiguous operands for membership", N);
362 elsif Nkind_In (N, N_Op_Eq, N_Op_Ne) then
363 Error_Msg_N ("ambiguous operands for equality", N);
365 else
366 Error_Msg_N ("ambiguous operands for comparison", N);
367 end if;
369 if All_Errors_Mode then
370 List_Operand_Interps (Left_Opnd (N));
371 List_Operand_Interps (Right_Opnd (N));
372 else
373 Error_Msg_N ("\use -gnatf switch for details", N);
374 end if;
375 end Ambiguous_Operands;
377 -----------------------
378 -- Analyze_Aggregate --
379 -----------------------
381 -- Most of the analysis of Aggregates requires that the type be known,
382 -- and is therefore put off until resolution.
384 procedure Analyze_Aggregate (N : Node_Id) is
385 begin
386 if No (Etype (N)) then
387 Set_Etype (N, Any_Composite);
388 end if;
389 end Analyze_Aggregate;
391 -----------------------
392 -- Analyze_Allocator --
393 -----------------------
395 procedure Analyze_Allocator (N : Node_Id) is
396 Loc : constant Source_Ptr := Sloc (N);
397 Sav_Errs : constant Nat := Serious_Errors_Detected;
398 E : Node_Id := Expression (N);
399 Acc_Type : Entity_Id;
400 Type_Id : Entity_Id;
401 P : Node_Id;
402 C : Node_Id;
404 begin
405 Check_SPARK_Restriction ("allocator is not allowed", N);
407 -- Deal with allocator restrictions
409 -- In accordance with H.4(7), the No_Allocators restriction only applies
410 -- to user-written allocators. The same consideration applies to the
411 -- No_Allocators_Before_Elaboration restriction.
413 if Comes_From_Source (N) then
414 Check_Restriction (No_Allocators, N);
416 -- Processing for No_Standard_Allocators_After_Elaboration, loop to
417 -- look at enclosing context, checking task/main subprogram case.
419 C := N;
420 P := Parent (C);
421 while Present (P) loop
423 -- In both cases we need a handled sequence of statements, where
424 -- the occurrence of the allocator is within the statements.
426 if Nkind (P) = N_Handled_Sequence_Of_Statements
427 and then Is_List_Member (C)
428 and then List_Containing (C) = Statements (P)
429 then
430 -- Check for allocator within task body, this is a definite
431 -- violation of No_Allocators_After_Elaboration we can detect.
433 if Nkind (Original_Node (Parent (P))) = N_Task_Body then
434 Check_Restriction
435 (No_Standard_Allocators_After_Elaboration, N);
436 exit;
437 end if;
439 -- The other case is appearance in a subprogram body. This may
440 -- be a violation if this is a library level subprogram, and it
441 -- turns out to be used as the main program, but only the
442 -- binder knows that, so just record the occurrence.
444 if Nkind (Original_Node (Parent (P))) = N_Subprogram_Body
445 and then Nkind (Parent (Parent (P))) = N_Compilation_Unit
446 then
447 Set_Has_Allocator (Current_Sem_Unit);
448 end if;
449 end if;
451 C := P;
452 P := Parent (C);
453 end loop;
454 end if;
456 -- Ada 2012 (AI05-0111-3): Analyze the subpool_specification, if
457 -- any. The expected type for the name is any type. A non-overloading
458 -- rule then requires it to be of a type descended from
459 -- System.Storage_Pools.Subpools.Subpool_Handle.
461 -- This isn't exactly what the AI says, but it seems to be the right
462 -- rule. The AI should be fixed.???
464 declare
465 Subpool : constant Node_Id := Subpool_Handle_Name (N);
467 begin
468 if Present (Subpool) then
469 Analyze (Subpool);
471 if Is_Overloaded (Subpool) then
472 Error_Msg_N ("ambiguous subpool handle", Subpool);
473 end if;
475 -- Check that Etype (Subpool) is descended from Subpool_Handle
477 Resolve (Subpool);
478 end if;
479 end;
481 -- Analyze the qualified expression or subtype indication
483 if Nkind (E) = N_Qualified_Expression then
484 Acc_Type := Create_Itype (E_Allocator_Type, N);
485 Set_Etype (Acc_Type, Acc_Type);
486 Find_Type (Subtype_Mark (E));
488 -- Analyze the qualified expression, and apply the name resolution
489 -- rule given in 4.7(3).
491 Analyze (E);
492 Type_Id := Etype (E);
493 Set_Directly_Designated_Type (Acc_Type, Type_Id);
495 Resolve (Expression (E), Type_Id);
497 -- Allocators generated by the build-in-place expansion mechanism
498 -- are explicitly marked as coming from source but do not need to be
499 -- checked for limited initialization. To exclude this case, ensure
500 -- that the parent of the allocator is a source node.
502 if Is_Limited_Type (Type_Id)
503 and then Comes_From_Source (N)
504 and then Comes_From_Source (Parent (N))
505 and then not In_Instance_Body
506 then
507 if not OK_For_Limited_Init (Type_Id, Expression (E)) then
508 Error_Msg_N ("initialization not allowed for limited types", N);
509 Explain_Limited_Type (Type_Id, N);
510 end if;
511 end if;
513 -- A qualified expression requires an exact match of the type,
514 -- class-wide matching is not allowed.
516 -- if Is_Class_Wide_Type (Type_Id)
517 -- and then Base_Type
518 -- (Etype (Expression (E))) /= Base_Type (Type_Id)
519 -- then
520 -- Wrong_Type (Expression (E), Type_Id);
521 -- end if;
523 Check_Non_Static_Context (Expression (E));
525 -- We don't analyze the qualified expression itself because it's
526 -- part of the allocator
528 Set_Etype (E, Type_Id);
530 -- Case where allocator has a subtype indication
532 else
533 declare
534 Def_Id : Entity_Id;
535 Base_Typ : Entity_Id;
537 begin
538 -- If the allocator includes a N_Subtype_Indication then a
539 -- constraint is present, otherwise the node is a subtype mark.
540 -- Introduce an explicit subtype declaration into the tree
541 -- defining some anonymous subtype and rewrite the allocator to
542 -- use this subtype rather than the subtype indication.
544 -- It is important to introduce the explicit subtype declaration
545 -- so that the bounds of the subtype indication are attached to
546 -- the tree in case the allocator is inside a generic unit.
548 if Nkind (E) = N_Subtype_Indication then
550 -- A constraint is only allowed for a composite type in Ada
551 -- 95. In Ada 83, a constraint is also allowed for an
552 -- access-to-composite type, but the constraint is ignored.
554 Find_Type (Subtype_Mark (E));
555 Base_Typ := Entity (Subtype_Mark (E));
557 if Is_Elementary_Type (Base_Typ) then
558 if not (Ada_Version = Ada_83
559 and then Is_Access_Type (Base_Typ))
560 then
561 Error_Msg_N ("constraint not allowed here", E);
563 if Nkind (Constraint (E)) =
564 N_Index_Or_Discriminant_Constraint
565 then
566 Error_Msg_N -- CODEFIX
567 ("\if qualified expression was meant, " &
568 "use apostrophe", Constraint (E));
569 end if;
570 end if;
572 -- Get rid of the bogus constraint:
574 Rewrite (E, New_Copy_Tree (Subtype_Mark (E)));
575 Analyze_Allocator (N);
576 return;
577 end if;
579 if Expander_Active then
580 Def_Id := Make_Temporary (Loc, 'S');
582 Insert_Action (E,
583 Make_Subtype_Declaration (Loc,
584 Defining_Identifier => Def_Id,
585 Subtype_Indication => Relocate_Node (E)));
587 if Sav_Errs /= Serious_Errors_Detected
588 and then Nkind (Constraint (E)) =
589 N_Index_Or_Discriminant_Constraint
590 then
591 Error_Msg_N -- CODEFIX
592 ("if qualified expression was meant, "
593 & "use apostrophe!", Constraint (E));
594 end if;
596 E := New_Occurrence_Of (Def_Id, Loc);
597 Rewrite (Expression (N), E);
598 end if;
599 end if;
601 Type_Id := Process_Subtype (E, N);
602 Acc_Type := Create_Itype (E_Allocator_Type, N);
603 Set_Etype (Acc_Type, Acc_Type);
604 Set_Directly_Designated_Type (Acc_Type, Type_Id);
605 Check_Fully_Declared (Type_Id, N);
607 -- Ada 2005 (AI-231): If the designated type is itself an access
608 -- type that excludes null, its default initialization will
609 -- be a null object, and we can insert an unconditional raise
610 -- before the allocator.
612 -- Ada 2012 (AI-104): A not null indication here is altogether
613 -- illegal.
615 if Can_Never_Be_Null (Type_Id) then
616 declare
617 Not_Null_Check : constant Node_Id :=
618 Make_Raise_Constraint_Error (Sloc (E),
619 Reason => CE_Null_Not_Allowed);
621 begin
622 if Expander_Active then
623 Insert_Action (N, Not_Null_Check);
624 Analyze (Not_Null_Check);
626 elsif Warn_On_Ada_2012_Compatibility then
627 Error_Msg_N
628 ("null value not allowed here in Ada 2012?y?", E);
629 end if;
630 end;
631 end if;
633 -- Check restriction against dynamically allocated protected
634 -- objects. Note that when limited aggregates are supported,
635 -- a similar test should be applied to an allocator with a
636 -- qualified expression ???
638 if Is_Protected_Type (Type_Id) then
639 Check_Restriction (No_Protected_Type_Allocators, N);
640 end if;
642 -- Check for missing initialization. Skip this check if we already
643 -- had errors on analyzing the allocator, since in that case these
644 -- are probably cascaded errors.
646 if Is_Indefinite_Subtype (Type_Id)
647 and then Serious_Errors_Detected = Sav_Errs
648 then
649 -- The build-in-place machinery may produce an allocator when
650 -- the designated type is indefinite but the underlying type is
651 -- not. In this case the unknown discriminants are meaningless
652 -- and should not trigger error messages. Check the parent node
653 -- because the allocator is marked as coming from source.
655 if Present (Underlying_Type (Type_Id))
656 and then not Is_Indefinite_Subtype (Underlying_Type (Type_Id))
657 and then not Comes_From_Source (Parent (N))
658 then
659 null;
661 elsif Is_Class_Wide_Type (Type_Id) then
662 Error_Msg_N
663 ("initialization required in class-wide allocation", N);
665 else
666 if Ada_Version < Ada_2005
667 and then Is_Limited_Type (Type_Id)
668 then
669 Error_Msg_N ("unconstrained allocation not allowed", N);
671 if Is_Array_Type (Type_Id) then
672 Error_Msg_N
673 ("\constraint with array bounds required", N);
675 elsif Has_Unknown_Discriminants (Type_Id) then
676 null;
678 else pragma Assert (Has_Discriminants (Type_Id));
679 Error_Msg_N
680 ("\constraint with discriminant values required", N);
681 end if;
683 -- Limited Ada 2005 and general non-limited case
685 else
686 Error_Msg_N
687 ("uninitialized unconstrained allocation not allowed",
690 if Is_Array_Type (Type_Id) then
691 Error_Msg_N
692 ("\qualified expression or constraint with " &
693 "array bounds required", N);
695 elsif Has_Unknown_Discriminants (Type_Id) then
696 Error_Msg_N ("\qualified expression required", N);
698 else pragma Assert (Has_Discriminants (Type_Id));
699 Error_Msg_N
700 ("\qualified expression or constraint with " &
701 "discriminant values required", N);
702 end if;
703 end if;
704 end if;
705 end if;
706 end;
707 end if;
709 if Is_Abstract_Type (Type_Id) then
710 Error_Msg_N ("cannot allocate abstract object", E);
711 end if;
713 if Has_Task (Designated_Type (Acc_Type)) then
714 Check_Restriction (No_Tasking, N);
715 Check_Restriction (Max_Tasks, N);
716 Check_Restriction (No_Task_Allocators, N);
717 end if;
719 -- AI05-0013-1: No_Nested_Finalization forbids allocators if the access
720 -- type is nested, and the designated type needs finalization. The rule
721 -- is conservative in that class-wide types need finalization.
723 if Needs_Finalization (Designated_Type (Acc_Type))
724 and then not Is_Library_Level_Entity (Acc_Type)
725 then
726 Check_Restriction (No_Nested_Finalization, N);
727 end if;
729 -- Check that an allocator of a nested access type doesn't create a
730 -- protected object when restriction No_Local_Protected_Objects applies.
731 -- We don't have an equivalent to Has_Task for protected types, so only
732 -- cases where the designated type itself is a protected type are
733 -- currently checked. ???
735 if Is_Protected_Type (Designated_Type (Acc_Type))
736 and then not Is_Library_Level_Entity (Acc_Type)
737 then
738 Check_Restriction (No_Local_Protected_Objects, N);
739 end if;
741 -- If the No_Streams restriction is set, check that the type of the
742 -- object is not, and does not contain, any subtype derived from
743 -- Ada.Streams.Root_Stream_Type. Note that we guard the call to
744 -- Has_Stream just for efficiency reasons. There is no point in
745 -- spending time on a Has_Stream check if the restriction is not set.
747 if Restriction_Check_Required (No_Streams) then
748 if Has_Stream (Designated_Type (Acc_Type)) then
749 Check_Restriction (No_Streams, N);
750 end if;
751 end if;
753 Set_Etype (N, Acc_Type);
755 if not Is_Library_Level_Entity (Acc_Type) then
756 Check_Restriction (No_Local_Allocators, N);
757 end if;
759 if Serious_Errors_Detected > Sav_Errs then
760 Set_Error_Posted (N);
761 Set_Etype (N, Any_Type);
762 end if;
763 end Analyze_Allocator;
765 ---------------------------
766 -- Analyze_Arithmetic_Op --
767 ---------------------------
769 procedure Analyze_Arithmetic_Op (N : Node_Id) is
770 L : constant Node_Id := Left_Opnd (N);
771 R : constant Node_Id := Right_Opnd (N);
772 Op_Id : Entity_Id;
774 begin
775 Candidate_Type := Empty;
776 Analyze_Expression (L);
777 Analyze_Expression (R);
779 -- If the entity is already set, the node is the instantiation of a
780 -- generic node with a non-local reference, or was manufactured by a
781 -- call to Make_Op_xxx. In either case the entity is known to be valid,
782 -- and we do not need to collect interpretations, instead we just get
783 -- the single possible interpretation.
785 Op_Id := Entity (N);
787 if Present (Op_Id) then
788 if Ekind (Op_Id) = E_Operator then
790 if Nkind_In (N, N_Op_Divide, N_Op_Mod, N_Op_Multiply, N_Op_Rem)
791 and then Treat_Fixed_As_Integer (N)
792 then
793 null;
794 else
795 Set_Etype (N, Any_Type);
796 Find_Arithmetic_Types (L, R, Op_Id, N);
797 end if;
799 else
800 Set_Etype (N, Any_Type);
801 Add_One_Interp (N, Op_Id, Etype (Op_Id));
802 end if;
804 -- Entity is not already set, so we do need to collect interpretations
806 else
807 Op_Id := Get_Name_Entity_Id (Chars (N));
808 Set_Etype (N, Any_Type);
810 while Present (Op_Id) loop
811 if Ekind (Op_Id) = E_Operator
812 and then Present (Next_Entity (First_Entity (Op_Id)))
813 then
814 Find_Arithmetic_Types (L, R, Op_Id, N);
816 -- The following may seem superfluous, because an operator cannot
817 -- be generic, but this ignores the cleverness of the author of
818 -- ACVC bc1013a.
820 elsif Is_Overloadable (Op_Id) then
821 Analyze_User_Defined_Binary_Op (N, Op_Id);
822 end if;
824 Op_Id := Homonym (Op_Id);
825 end loop;
826 end if;
828 Operator_Check (N);
829 end Analyze_Arithmetic_Op;
831 ------------------
832 -- Analyze_Call --
833 ------------------
835 -- Function, procedure, and entry calls are checked here. The Name in
836 -- the call may be overloaded. The actuals have been analyzed and may
837 -- themselves be overloaded. On exit from this procedure, the node N
838 -- may have zero, one or more interpretations. In the first case an
839 -- error message is produced. In the last case, the node is flagged
840 -- as overloaded and the interpretations are collected in All_Interp.
842 -- If the name is an Access_To_Subprogram, it cannot be overloaded, but
843 -- the type-checking is similar to that of other calls.
845 procedure Analyze_Call (N : Node_Id) is
846 Actuals : constant List_Id := Parameter_Associations (N);
847 Nam : Node_Id;
848 X : Interp_Index;
849 It : Interp;
850 Nam_Ent : Entity_Id;
851 Success : Boolean := False;
853 Deref : Boolean := False;
854 -- Flag indicates whether an interpretation of the prefix is a
855 -- parameterless call that returns an access_to_subprogram.
857 procedure Check_Ghost_Subprogram_Call;
858 -- Verify the legality of a call to a ghost subprogram. Such calls can
859 -- appear only in assertion expressions except subtype predicates or
860 -- from within another ghost subprogram.
862 procedure Check_Mixed_Parameter_And_Named_Associations;
863 -- Check that parameter and named associations are not mixed. This is
864 -- a restriction in SPARK mode.
866 function Name_Denotes_Function return Boolean;
867 -- If the type of the name is an access to subprogram, this may be the
868 -- type of a name, or the return type of the function being called. If
869 -- the name is not an entity then it can denote a protected function.
870 -- Until we distinguish Etype from Return_Type, we must use this routine
871 -- to resolve the meaning of the name in the call.
873 procedure No_Interpretation;
874 -- Output error message when no valid interpretation exists
876 ---------------------------------
877 -- Check_Ghost_Subprogram_Call --
878 ---------------------------------
880 procedure Check_Ghost_Subprogram_Call is
881 S : Entity_Id;
883 begin
884 -- Do not perform the check while preanalyzing the enclosing context
885 -- because the call is not in its final place. Premature attempts to
886 -- verify the placement lead to bogus errors.
888 if In_Spec_Expression then
889 return;
891 -- The ghost subprogram appears inside an assertion expression which
892 -- is one of the allowed cases.
894 elsif In_Assertion_Expression_Pragma (N) then
895 return;
897 -- Otherwise see if it inside another ghost subprogram
899 else
900 -- Loop to climb scopes
902 S := Current_Scope;
903 while Present (S) and then S /= Standard_Standard loop
905 -- The call appears inside another ghost subprogram
907 if Is_Ghost_Subprogram (S) then
908 return;
909 end if;
911 S := Scope (S);
912 end loop;
914 -- If we fall through the loop it was not within another
915 -- ghost subprogram, so we have bad placement.
917 Error_Msg_N
918 ("call to ghost subprogram must appear in assertion expression "
919 & "or another ghost subprogram", N);
920 end if;
921 end Check_Ghost_Subprogram_Call;
923 --------------------------------------------------
924 -- Check_Mixed_Parameter_And_Named_Associations --
925 --------------------------------------------------
927 procedure Check_Mixed_Parameter_And_Named_Associations is
928 Actual : Node_Id;
929 Named_Seen : Boolean;
931 begin
932 Named_Seen := False;
934 Actual := First (Actuals);
935 while Present (Actual) loop
936 case Nkind (Actual) is
937 when N_Parameter_Association =>
938 if Named_Seen then
939 Check_SPARK_Restriction
940 ("named association cannot follow positional one",
941 Actual);
942 exit;
943 end if;
944 when others =>
945 Named_Seen := True;
946 end case;
948 Next (Actual);
949 end loop;
950 end Check_Mixed_Parameter_And_Named_Associations;
952 ---------------------------
953 -- Name_Denotes_Function --
954 ---------------------------
956 function Name_Denotes_Function return Boolean is
957 begin
958 if Is_Entity_Name (Nam) then
959 return Ekind (Entity (Nam)) = E_Function;
961 elsif Nkind (Nam) = N_Selected_Component then
962 return Ekind (Entity (Selector_Name (Nam))) = E_Function;
964 else
965 return False;
966 end if;
967 end Name_Denotes_Function;
969 -----------------------
970 -- No_Interpretation --
971 -----------------------
973 procedure No_Interpretation is
974 L : constant Boolean := Is_List_Member (N);
975 K : constant Node_Kind := Nkind (Parent (N));
977 begin
978 -- If the node is in a list whose parent is not an expression then it
979 -- must be an attempted procedure call.
981 if L and then K not in N_Subexpr then
982 if Ekind (Entity (Nam)) = E_Generic_Procedure then
983 Error_Msg_NE
984 ("must instantiate generic procedure& before call",
985 Nam, Entity (Nam));
986 else
987 Error_Msg_N
988 ("procedure or entry name expected", Nam);
989 end if;
991 -- Check for tasking cases where only an entry call will do
993 elsif not L
994 and then Nkind_In (K, N_Entry_Call_Alternative,
995 N_Triggering_Alternative)
996 then
997 Error_Msg_N ("entry name expected", Nam);
999 -- Otherwise give general error message
1001 else
1002 Error_Msg_N ("invalid prefix in call", Nam);
1003 end if;
1004 end No_Interpretation;
1006 -- Start of processing for Analyze_Call
1008 begin
1009 if Restriction_Check_Required (SPARK_05) then
1010 Check_Mixed_Parameter_And_Named_Associations;
1011 end if;
1013 -- Initialize the type of the result of the call to the error type,
1014 -- which will be reset if the type is successfully resolved.
1016 Set_Etype (N, Any_Type);
1018 Nam := Name (N);
1020 if not Is_Overloaded (Nam) then
1022 -- Only one interpretation to check
1024 if Ekind (Etype (Nam)) = E_Subprogram_Type then
1025 Nam_Ent := Etype (Nam);
1027 -- If the prefix is an access_to_subprogram, this may be an indirect
1028 -- call. This is the case if the name in the call is not an entity
1029 -- name, or if it is a function name in the context of a procedure
1030 -- call. In this latter case, we have a call to a parameterless
1031 -- function that returns a pointer_to_procedure which is the entity
1032 -- being called. Finally, F (X) may be a call to a parameterless
1033 -- function that returns a pointer to a function with parameters.
1034 -- Note that if F returns an access-to-subprogram whose designated
1035 -- type is an array, F (X) cannot be interpreted as an indirect call
1036 -- through the result of the call to F.
1038 elsif Is_Access_Type (Etype (Nam))
1039 and then Ekind (Designated_Type (Etype (Nam))) = E_Subprogram_Type
1040 and then
1041 (not Name_Denotes_Function
1042 or else Nkind (N) = N_Procedure_Call_Statement
1043 or else
1044 (Nkind (Parent (N)) /= N_Explicit_Dereference
1045 and then Is_Entity_Name (Nam)
1046 and then No (First_Formal (Entity (Nam)))
1047 and then not
1048 Is_Array_Type (Etype (Designated_Type (Etype (Nam))))
1049 and then Present (Actuals)))
1050 then
1051 Nam_Ent := Designated_Type (Etype (Nam));
1052 Insert_Explicit_Dereference (Nam);
1054 -- Selected component case. Simple entry or protected operation,
1055 -- where the entry name is given by the selector name.
1057 elsif Nkind (Nam) = N_Selected_Component then
1058 Nam_Ent := Entity (Selector_Name (Nam));
1060 if not Ekind_In (Nam_Ent, E_Entry,
1061 E_Entry_Family,
1062 E_Function,
1063 E_Procedure)
1064 then
1065 Error_Msg_N ("name in call is not a callable entity", Nam);
1066 Set_Etype (N, Any_Type);
1067 return;
1068 end if;
1070 -- If the name is an Indexed component, it can be a call to a member
1071 -- of an entry family. The prefix must be a selected component whose
1072 -- selector is the entry. Analyze_Procedure_Call normalizes several
1073 -- kinds of call into this form.
1075 elsif Nkind (Nam) = N_Indexed_Component then
1076 if Nkind (Prefix (Nam)) = N_Selected_Component then
1077 Nam_Ent := Entity (Selector_Name (Prefix (Nam)));
1078 else
1079 Error_Msg_N ("name in call is not a callable entity", Nam);
1080 Set_Etype (N, Any_Type);
1081 return;
1082 end if;
1084 elsif not Is_Entity_Name (Nam) then
1085 Error_Msg_N ("name in call is not a callable entity", Nam);
1086 Set_Etype (N, Any_Type);
1087 return;
1089 else
1090 Nam_Ent := Entity (Nam);
1092 -- If not overloadable, this may be a generalized indexing
1093 -- operation with named associations. Rewrite again as an
1094 -- indexed component and analyze as container indexing.
1096 if not Is_Overloadable (Nam_Ent) then
1097 if Present
1098 (Find_Value_Of_Aspect
1099 (Etype (Nam_Ent), Aspect_Constant_Indexing))
1100 then
1101 Replace (N,
1102 Make_Indexed_Component (Sloc (N),
1103 Prefix => Nam,
1104 Expressions => Parameter_Associations (N)));
1106 if Try_Container_Indexing (N, Nam, Expressions (N)) then
1107 return;
1108 else
1109 No_Interpretation;
1110 end if;
1112 else
1113 No_Interpretation;
1114 end if;
1116 return;
1117 end if;
1118 end if;
1120 -- Operations generated for RACW stub types are called only through
1121 -- dispatching, and can never be the static interpretation of a call.
1123 if Is_RACW_Stub_Type_Operation (Nam_Ent) then
1124 No_Interpretation;
1125 return;
1126 end if;
1128 Analyze_One_Call (N, Nam_Ent, True, Success);
1130 -- If this is an indirect call, the return type of the access_to
1131 -- subprogram may be an incomplete type. At the point of the call,
1132 -- use the full type if available, and at the same time update the
1133 -- return type of the access_to_subprogram.
1135 if Success
1136 and then Nkind (Nam) = N_Explicit_Dereference
1137 and then Ekind (Etype (N)) = E_Incomplete_Type
1138 and then Present (Full_View (Etype (N)))
1139 then
1140 Set_Etype (N, Full_View (Etype (N)));
1141 Set_Etype (Nam_Ent, Etype (N));
1142 end if;
1144 -- Overloaded call
1146 else
1147 -- An overloaded selected component must denote overloaded operations
1148 -- of a concurrent type. The interpretations are attached to the
1149 -- simple name of those operations.
1151 if Nkind (Nam) = N_Selected_Component then
1152 Nam := Selector_Name (Nam);
1153 end if;
1155 Get_First_Interp (Nam, X, It);
1157 while Present (It.Nam) loop
1158 Nam_Ent := It.Nam;
1159 Deref := False;
1161 -- Name may be call that returns an access to subprogram, or more
1162 -- generally an overloaded expression one of whose interpretations
1163 -- yields an access to subprogram. If the name is an entity, we do
1164 -- not dereference, because the node is a call that returns the
1165 -- access type: note difference between f(x), where the call may
1166 -- return an access subprogram type, and f(x)(y), where the type
1167 -- returned by the call to f is implicitly dereferenced to analyze
1168 -- the outer call.
1170 if Is_Access_Type (Nam_Ent) then
1171 Nam_Ent := Designated_Type (Nam_Ent);
1173 elsif Is_Access_Type (Etype (Nam_Ent))
1174 and then
1175 (not Is_Entity_Name (Nam)
1176 or else Nkind (N) = N_Procedure_Call_Statement)
1177 and then Ekind (Designated_Type (Etype (Nam_Ent)))
1178 = E_Subprogram_Type
1179 then
1180 Nam_Ent := Designated_Type (Etype (Nam_Ent));
1182 if Is_Entity_Name (Nam) then
1183 Deref := True;
1184 end if;
1185 end if;
1187 -- If the call has been rewritten from a prefixed call, the first
1188 -- parameter has been analyzed, but may need a subsequent
1189 -- dereference, so skip its analysis now.
1191 if N /= Original_Node (N)
1192 and then Nkind (Original_Node (N)) = Nkind (N)
1193 and then Nkind (Name (N)) /= Nkind (Name (Original_Node (N)))
1194 and then Present (Parameter_Associations (N))
1195 and then Present (Etype (First (Parameter_Associations (N))))
1196 then
1197 Analyze_One_Call
1198 (N, Nam_Ent, False, Success, Skip_First => True);
1199 else
1200 Analyze_One_Call (N, Nam_Ent, False, Success);
1201 end if;
1203 -- If the interpretation succeeds, mark the proper type of the
1204 -- prefix (any valid candidate will do). If not, remove the
1205 -- candidate interpretation. This only needs to be done for
1206 -- overloaded protected operations, for other entities disambi-
1207 -- guation is done directly in Resolve.
1209 if Success then
1210 if Deref
1211 and then Nkind (Parent (N)) /= N_Explicit_Dereference
1212 then
1213 Set_Entity (Nam, It.Nam);
1214 Insert_Explicit_Dereference (Nam);
1215 Set_Etype (Nam, Nam_Ent);
1217 else
1218 Set_Etype (Nam, It.Typ);
1219 end if;
1221 elsif Nkind_In (Name (N), N_Selected_Component,
1222 N_Function_Call)
1223 then
1224 Remove_Interp (X);
1225 end if;
1227 Get_Next_Interp (X, It);
1228 end loop;
1230 -- If the name is the result of a function call, it can only be a
1231 -- call to a function returning an access to subprogram. Insert
1232 -- explicit dereference.
1234 if Nkind (Nam) = N_Function_Call then
1235 Insert_Explicit_Dereference (Nam);
1236 end if;
1238 if Etype (N) = Any_Type then
1240 -- None of the interpretations is compatible with the actuals
1242 Diagnose_Call (N, Nam);
1244 -- Special checks for uninstantiated put routines
1246 if Nkind (N) = N_Procedure_Call_Statement
1247 and then Is_Entity_Name (Nam)
1248 and then Chars (Nam) = Name_Put
1249 and then List_Length (Actuals) = 1
1250 then
1251 declare
1252 Arg : constant Node_Id := First (Actuals);
1253 Typ : Entity_Id;
1255 begin
1256 if Nkind (Arg) = N_Parameter_Association then
1257 Typ := Etype (Explicit_Actual_Parameter (Arg));
1258 else
1259 Typ := Etype (Arg);
1260 end if;
1262 if Is_Signed_Integer_Type (Typ) then
1263 Error_Msg_N
1264 ("possible missing instantiation of "
1265 & "'Text_'I'O.'Integer_'I'O!", Nam);
1267 elsif Is_Modular_Integer_Type (Typ) then
1268 Error_Msg_N
1269 ("possible missing instantiation of "
1270 & "'Text_'I'O.'Modular_'I'O!", Nam);
1272 elsif Is_Floating_Point_Type (Typ) then
1273 Error_Msg_N
1274 ("possible missing instantiation of "
1275 & "'Text_'I'O.'Float_'I'O!", Nam);
1277 elsif Is_Ordinary_Fixed_Point_Type (Typ) then
1278 Error_Msg_N
1279 ("possible missing instantiation of "
1280 & "'Text_'I'O.'Fixed_'I'O!", Nam);
1282 elsif Is_Decimal_Fixed_Point_Type (Typ) then
1283 Error_Msg_N
1284 ("possible missing instantiation of "
1285 & "'Text_'I'O.'Decimal_'I'O!", Nam);
1287 elsif Is_Enumeration_Type (Typ) then
1288 Error_Msg_N
1289 ("possible missing instantiation of "
1290 & "'Text_'I'O.'Enumeration_'I'O!", Nam);
1291 end if;
1292 end;
1293 end if;
1295 elsif not Is_Overloaded (N)
1296 and then Is_Entity_Name (Nam)
1297 then
1298 -- Resolution yields a single interpretation. Verify that the
1299 -- reference has capitalization consistent with the declaration.
1301 Set_Entity_With_Checks (Nam, Entity (Nam));
1302 Generate_Reference (Entity (Nam), Nam);
1304 Set_Etype (Nam, Etype (Entity (Nam)));
1305 else
1306 Remove_Abstract_Operations (N);
1307 end if;
1309 End_Interp_List;
1310 end if;
1312 -- A call to a ghost subprogram is allowed only in assertion expressions
1313 -- excluding subtype predicates or from within another ghost subprogram.
1315 if Is_Ghost_Subprogram (Get_Subprogram_Entity (N)) then
1316 Check_Ghost_Subprogram_Call;
1317 end if;
1318 end Analyze_Call;
1320 -----------------------------
1321 -- Analyze_Case_Expression --
1322 -----------------------------
1324 procedure Analyze_Case_Expression (N : Node_Id) is
1325 function Has_Static_Predicate (Subtyp : Entity_Id) return Boolean;
1326 -- Determine whether subtype Subtyp has aspect Static_Predicate
1328 procedure Non_Static_Choice_Error (Choice : Node_Id);
1329 -- Error routine invoked by the generic instantiation below when
1330 -- the case expression has a non static choice.
1332 package Case_Choices_Analysis is new
1333 Generic_Analyze_Choices
1334 (Process_Associated_Node => No_OP);
1335 use Case_Choices_Analysis;
1337 package Case_Choices_Checking is new
1338 Generic_Check_Choices
1339 (Process_Empty_Choice => No_OP,
1340 Process_Non_Static_Choice => Non_Static_Choice_Error,
1341 Process_Associated_Node => No_OP);
1342 use Case_Choices_Checking;
1344 --------------------------
1345 -- Has_Static_Predicate --
1346 --------------------------
1348 function Has_Static_Predicate (Subtyp : Entity_Id) return Boolean is
1349 Item : Node_Id;
1351 begin
1352 Item := First_Rep_Item (Subtyp);
1353 while Present (Item) loop
1354 if Nkind (Item) = N_Aspect_Specification
1355 and then Chars (Identifier (Item)) = Name_Static_Predicate
1356 then
1357 return True;
1358 end if;
1360 Next_Rep_Item (Item);
1361 end loop;
1363 return False;
1364 end Has_Static_Predicate;
1366 -----------------------------
1367 -- Non_Static_Choice_Error --
1368 -----------------------------
1370 procedure Non_Static_Choice_Error (Choice : Node_Id) is
1371 begin
1372 Flag_Non_Static_Expr
1373 ("choice given in case expression is not static!", Choice);
1374 end Non_Static_Choice_Error;
1376 -- Local variables
1378 Expr : constant Node_Id := Expression (N);
1379 Alt : Node_Id;
1380 Exp_Type : Entity_Id;
1381 Exp_Btype : Entity_Id;
1383 FirstX : Node_Id := Empty;
1384 -- First expression in the case for which there is some type information
1385 -- available, i.e. it is not Any_Type, which can happen because of some
1386 -- error, or from the use of e.g. raise Constraint_Error.
1388 Others_Present : Boolean;
1389 -- Indicates if Others was present
1391 -- Start of processing for Analyze_Case_Expression
1393 begin
1394 if Comes_From_Source (N) then
1395 Check_Compiler_Unit (N);
1396 end if;
1398 Analyze_And_Resolve (Expr, Any_Discrete);
1399 Check_Unset_Reference (Expr);
1400 Exp_Type := Etype (Expr);
1401 Exp_Btype := Base_Type (Exp_Type);
1403 Alt := First (Alternatives (N));
1404 while Present (Alt) loop
1405 Analyze (Expression (Alt));
1407 if No (FirstX) and then Etype (Expression (Alt)) /= Any_Type then
1408 FirstX := Expression (Alt);
1409 end if;
1411 Next (Alt);
1412 end loop;
1414 -- Get our initial type from the first expression for which we got some
1415 -- useful type information from the expression.
1417 if not Is_Overloaded (FirstX) then
1418 Set_Etype (N, Etype (FirstX));
1420 else
1421 declare
1422 I : Interp_Index;
1423 It : Interp;
1425 begin
1426 Set_Etype (N, Any_Type);
1428 Get_First_Interp (FirstX, I, It);
1429 while Present (It.Nam) loop
1431 -- For each interpretation of the first expression, we only
1432 -- add the interpretation if every other expression in the
1433 -- case expression alternatives has a compatible type.
1435 Alt := Next (First (Alternatives (N)));
1436 while Present (Alt) loop
1437 exit when not Has_Compatible_Type (Expression (Alt), It.Typ);
1438 Next (Alt);
1439 end loop;
1441 if No (Alt) then
1442 Add_One_Interp (N, It.Typ, It.Typ);
1443 end if;
1445 Get_Next_Interp (I, It);
1446 end loop;
1447 end;
1448 end if;
1450 Exp_Btype := Base_Type (Exp_Type);
1452 -- The expression must be of a discrete type which must be determinable
1453 -- independently of the context in which the expression occurs, but
1454 -- using the fact that the expression must be of a discrete type.
1455 -- Moreover, the type this expression must not be a character literal
1456 -- (which is always ambiguous).
1458 -- If error already reported by Resolve, nothing more to do
1460 if Exp_Btype = Any_Discrete or else Exp_Btype = Any_Type then
1461 return;
1463 elsif Exp_Btype = Any_Character then
1464 Error_Msg_N
1465 ("character literal as case expression is ambiguous", Expr);
1466 return;
1467 end if;
1469 -- If the case expression is a formal object of mode in out, then
1470 -- treat it as having a nonstatic subtype by forcing use of the base
1471 -- type (which has to get passed to Check_Case_Choices below). Also
1472 -- use base type when the case expression is parenthesized.
1474 if Paren_Count (Expr) > 0
1475 or else (Is_Entity_Name (Expr)
1476 and then Ekind (Entity (Expr)) = E_Generic_In_Out_Parameter)
1477 then
1478 Exp_Type := Exp_Btype;
1479 end if;
1481 -- The case expression alternatives cover the range of a static subtype
1482 -- subject to aspect Static_Predicate. Do not check the choices when the
1483 -- case expression has not been fully analyzed yet because this may lead
1484 -- to bogus errors.
1486 if Is_Static_Subtype (Exp_Type)
1487 and then Has_Static_Predicate (Exp_Type)
1488 and then In_Spec_Expression
1489 then
1490 null;
1492 -- Call Analyze_Choices and Check_Choices to do the rest of the work
1494 else
1495 Analyze_Choices (Alternatives (N), Exp_Type);
1496 Check_Choices (N, Alternatives (N), Exp_Type, Others_Present);
1497 end if;
1499 if Exp_Type = Universal_Integer and then not Others_Present then
1500 Error_Msg_N
1501 ("case on universal integer requires OTHERS choice", Expr);
1502 end if;
1503 end Analyze_Case_Expression;
1505 ---------------------------
1506 -- Analyze_Comparison_Op --
1507 ---------------------------
1509 procedure Analyze_Comparison_Op (N : Node_Id) is
1510 L : constant Node_Id := Left_Opnd (N);
1511 R : constant Node_Id := Right_Opnd (N);
1512 Op_Id : Entity_Id := Entity (N);
1514 begin
1515 Set_Etype (N, Any_Type);
1516 Candidate_Type := Empty;
1518 Analyze_Expression (L);
1519 Analyze_Expression (R);
1521 if Present (Op_Id) then
1522 if Ekind (Op_Id) = E_Operator then
1523 Find_Comparison_Types (L, R, Op_Id, N);
1524 else
1525 Add_One_Interp (N, Op_Id, Etype (Op_Id));
1526 end if;
1528 if Is_Overloaded (L) then
1529 Set_Etype (L, Intersect_Types (L, R));
1530 end if;
1532 else
1533 Op_Id := Get_Name_Entity_Id (Chars (N));
1534 while Present (Op_Id) loop
1535 if Ekind (Op_Id) = E_Operator then
1536 Find_Comparison_Types (L, R, Op_Id, N);
1537 else
1538 Analyze_User_Defined_Binary_Op (N, Op_Id);
1539 end if;
1541 Op_Id := Homonym (Op_Id);
1542 end loop;
1543 end if;
1545 Operator_Check (N);
1546 end Analyze_Comparison_Op;
1548 ---------------------------
1549 -- Analyze_Concatenation --
1550 ---------------------------
1552 procedure Analyze_Concatenation (N : Node_Id) is
1554 -- We wish to avoid deep recursion, because concatenations are often
1555 -- deeply nested, as in A&B&...&Z. Therefore, we walk down the left
1556 -- operands nonrecursively until we find something that is not a
1557 -- concatenation (A in this case), or has already been analyzed. We
1558 -- analyze that, and then walk back up the tree following Parent
1559 -- pointers, calling Analyze_Concatenation_Rest to do the rest of the
1560 -- work at each level. The Parent pointers allow us to avoid recursion,
1561 -- and thus avoid running out of memory.
1563 NN : Node_Id := N;
1564 L : Node_Id;
1566 begin
1567 Candidate_Type := Empty;
1569 -- The following code is equivalent to:
1571 -- Set_Etype (N, Any_Type);
1572 -- Analyze_Expression (Left_Opnd (N));
1573 -- Analyze_Concatenation_Rest (N);
1575 -- where the Analyze_Expression call recurses back here if the left
1576 -- operand is a concatenation.
1578 -- Walk down left operands
1580 loop
1581 Set_Etype (NN, Any_Type);
1582 L := Left_Opnd (NN);
1583 exit when Nkind (L) /= N_Op_Concat or else Analyzed (L);
1584 NN := L;
1585 end loop;
1587 -- Now (given the above example) NN is A&B and L is A
1589 -- First analyze L ...
1591 Analyze_Expression (L);
1593 -- ... then walk NN back up until we reach N (where we started), calling
1594 -- Analyze_Concatenation_Rest along the way.
1596 loop
1597 Analyze_Concatenation_Rest (NN);
1598 exit when NN = N;
1599 NN := Parent (NN);
1600 end loop;
1601 end Analyze_Concatenation;
1603 --------------------------------
1604 -- Analyze_Concatenation_Rest --
1605 --------------------------------
1607 -- If the only one-dimensional array type in scope is String,
1608 -- this is the resulting type of the operation. Otherwise there
1609 -- will be a concatenation operation defined for each user-defined
1610 -- one-dimensional array.
1612 procedure Analyze_Concatenation_Rest (N : Node_Id) is
1613 L : constant Node_Id := Left_Opnd (N);
1614 R : constant Node_Id := Right_Opnd (N);
1615 Op_Id : Entity_Id := Entity (N);
1616 LT : Entity_Id;
1617 RT : Entity_Id;
1619 begin
1620 Analyze_Expression (R);
1622 -- If the entity is present, the node appears in an instance, and
1623 -- denotes a predefined concatenation operation. The resulting type is
1624 -- obtained from the arguments when possible. If the arguments are
1625 -- aggregates, the array type and the concatenation type must be
1626 -- visible.
1628 if Present (Op_Id) then
1629 if Ekind (Op_Id) = E_Operator then
1630 LT := Base_Type (Etype (L));
1631 RT := Base_Type (Etype (R));
1633 if Is_Array_Type (LT)
1634 and then (RT = LT or else RT = Base_Type (Component_Type (LT)))
1635 then
1636 Add_One_Interp (N, Op_Id, LT);
1638 elsif Is_Array_Type (RT)
1639 and then LT = Base_Type (Component_Type (RT))
1640 then
1641 Add_One_Interp (N, Op_Id, RT);
1643 -- If one operand is a string type or a user-defined array type,
1644 -- and the other is a literal, result is of the specific type.
1646 elsif
1647 (Root_Type (LT) = Standard_String
1648 or else Scope (LT) /= Standard_Standard)
1649 and then Etype (R) = Any_String
1650 then
1651 Add_One_Interp (N, Op_Id, LT);
1653 elsif
1654 (Root_Type (RT) = Standard_String
1655 or else Scope (RT) /= Standard_Standard)
1656 and then Etype (L) = Any_String
1657 then
1658 Add_One_Interp (N, Op_Id, RT);
1660 elsif not Is_Generic_Type (Etype (Op_Id)) then
1661 Add_One_Interp (N, Op_Id, Etype (Op_Id));
1663 else
1664 -- Type and its operations must be visible
1666 Set_Entity (N, Empty);
1667 Analyze_Concatenation (N);
1668 end if;
1670 else
1671 Add_One_Interp (N, Op_Id, Etype (Op_Id));
1672 end if;
1674 else
1675 Op_Id := Get_Name_Entity_Id (Name_Op_Concat);
1676 while Present (Op_Id) loop
1677 if Ekind (Op_Id) = E_Operator then
1679 -- Do not consider operators declared in dead code, they can
1680 -- not be part of the resolution.
1682 if Is_Eliminated (Op_Id) then
1683 null;
1684 else
1685 Find_Concatenation_Types (L, R, Op_Id, N);
1686 end if;
1688 else
1689 Analyze_User_Defined_Binary_Op (N, Op_Id);
1690 end if;
1692 Op_Id := Homonym (Op_Id);
1693 end loop;
1694 end if;
1696 Operator_Check (N);
1697 end Analyze_Concatenation_Rest;
1699 -------------------------
1700 -- Analyze_Equality_Op --
1701 -------------------------
1703 procedure Analyze_Equality_Op (N : Node_Id) is
1704 Loc : constant Source_Ptr := Sloc (N);
1705 L : constant Node_Id := Left_Opnd (N);
1706 R : constant Node_Id := Right_Opnd (N);
1707 Op_Id : Entity_Id;
1709 begin
1710 Set_Etype (N, Any_Type);
1711 Candidate_Type := Empty;
1713 Analyze_Expression (L);
1714 Analyze_Expression (R);
1716 -- If the entity is set, the node is a generic instance with a non-local
1717 -- reference to the predefined operator or to a user-defined function.
1718 -- It can also be an inequality that is expanded into the negation of a
1719 -- call to a user-defined equality operator.
1721 -- For the predefined case, the result is Boolean, regardless of the
1722 -- type of the operands. The operands may even be limited, if they are
1723 -- generic actuals. If they are overloaded, label the left argument with
1724 -- the common type that must be present, or with the type of the formal
1725 -- of the user-defined function.
1727 if Present (Entity (N)) then
1728 Op_Id := Entity (N);
1730 if Ekind (Op_Id) = E_Operator then
1731 Add_One_Interp (N, Op_Id, Standard_Boolean);
1732 else
1733 Add_One_Interp (N, Op_Id, Etype (Op_Id));
1734 end if;
1736 if Is_Overloaded (L) then
1737 if Ekind (Op_Id) = E_Operator then
1738 Set_Etype (L, Intersect_Types (L, R));
1739 else
1740 Set_Etype (L, Etype (First_Formal (Op_Id)));
1741 end if;
1742 end if;
1744 else
1745 Op_Id := Get_Name_Entity_Id (Chars (N));
1746 while Present (Op_Id) loop
1747 if Ekind (Op_Id) = E_Operator then
1748 Find_Equality_Types (L, R, Op_Id, N);
1749 else
1750 Analyze_User_Defined_Binary_Op (N, Op_Id);
1751 end if;
1753 Op_Id := Homonym (Op_Id);
1754 end loop;
1755 end if;
1757 -- If there was no match, and the operator is inequality, this may
1758 -- be a case where inequality has not been made explicit, as for
1759 -- tagged types. Analyze the node as the negation of an equality
1760 -- operation. This cannot be done earlier, because before analysis
1761 -- we cannot rule out the presence of an explicit inequality.
1763 if Etype (N) = Any_Type
1764 and then Nkind (N) = N_Op_Ne
1765 then
1766 Op_Id := Get_Name_Entity_Id (Name_Op_Eq);
1767 while Present (Op_Id) loop
1768 if Ekind (Op_Id) = E_Operator then
1769 Find_Equality_Types (L, R, Op_Id, N);
1770 else
1771 Analyze_User_Defined_Binary_Op (N, Op_Id);
1772 end if;
1774 Op_Id := Homonym (Op_Id);
1775 end loop;
1777 if Etype (N) /= Any_Type then
1778 Op_Id := Entity (N);
1780 Rewrite (N,
1781 Make_Op_Not (Loc,
1782 Right_Opnd =>
1783 Make_Op_Eq (Loc,
1784 Left_Opnd => Left_Opnd (N),
1785 Right_Opnd => Right_Opnd (N))));
1787 Set_Entity (Right_Opnd (N), Op_Id);
1788 Analyze (N);
1789 end if;
1790 end if;
1792 Operator_Check (N);
1793 end Analyze_Equality_Op;
1795 ----------------------------------
1796 -- Analyze_Explicit_Dereference --
1797 ----------------------------------
1799 procedure Analyze_Explicit_Dereference (N : Node_Id) is
1800 Loc : constant Source_Ptr := Sloc (N);
1801 P : constant Node_Id := Prefix (N);
1802 T : Entity_Id;
1803 I : Interp_Index;
1804 It : Interp;
1805 New_N : Node_Id;
1807 function Is_Function_Type return Boolean;
1808 -- Check whether node may be interpreted as an implicit function call
1810 ----------------------
1811 -- Is_Function_Type --
1812 ----------------------
1814 function Is_Function_Type return Boolean is
1815 I : Interp_Index;
1816 It : Interp;
1818 begin
1819 if not Is_Overloaded (N) then
1820 return Ekind (Base_Type (Etype (N))) = E_Subprogram_Type
1821 and then Etype (Base_Type (Etype (N))) /= Standard_Void_Type;
1823 else
1824 Get_First_Interp (N, I, It);
1825 while Present (It.Nam) loop
1826 if Ekind (Base_Type (It.Typ)) /= E_Subprogram_Type
1827 or else Etype (Base_Type (It.Typ)) = Standard_Void_Type
1828 then
1829 return False;
1830 end if;
1832 Get_Next_Interp (I, It);
1833 end loop;
1835 return True;
1836 end if;
1837 end Is_Function_Type;
1839 -- Start of processing for Analyze_Explicit_Dereference
1841 begin
1842 -- If source node, check SPARK restriction. We guard this with the
1843 -- source node check, because ???
1845 if Comes_From_Source (N) then
1846 Check_SPARK_Restriction ("explicit dereference is not allowed", N);
1847 end if;
1849 -- In formal verification mode, keep track of all reads and writes
1850 -- through explicit dereferences.
1852 if GNATprove_Mode then
1853 SPARK_Specific.Generate_Dereference (N);
1854 end if;
1856 Analyze (P);
1857 Set_Etype (N, Any_Type);
1859 -- Test for remote access to subprogram type, and if so return
1860 -- after rewriting the original tree.
1862 if Remote_AST_E_Dereference (P) then
1863 return;
1864 end if;
1866 -- Normal processing for other than remote access to subprogram type
1868 if not Is_Overloaded (P) then
1869 if Is_Access_Type (Etype (P)) then
1871 -- Set the Etype. We need to go through Is_For_Access_Subtypes to
1872 -- avoid other problems caused by the Private_Subtype and it is
1873 -- safe to go to the Base_Type because this is the same as
1874 -- converting the access value to its Base_Type.
1876 declare
1877 DT : Entity_Id := Designated_Type (Etype (P));
1879 begin
1880 if Ekind (DT) = E_Private_Subtype
1881 and then Is_For_Access_Subtype (DT)
1882 then
1883 DT := Base_Type (DT);
1884 end if;
1886 -- An explicit dereference is a legal occurrence of an
1887 -- incomplete type imported through a limited_with clause,
1888 -- if the full view is visible.
1890 if From_Limited_With (DT)
1891 and then not From_Limited_With (Scope (DT))
1892 and then
1893 (Is_Immediately_Visible (Scope (DT))
1894 or else
1895 (Is_Child_Unit (Scope (DT))
1896 and then Is_Visible_Lib_Unit (Scope (DT))))
1897 then
1898 Set_Etype (N, Available_View (DT));
1900 else
1901 Set_Etype (N, DT);
1902 end if;
1903 end;
1905 elsif Etype (P) /= Any_Type then
1906 Error_Msg_N ("prefix of dereference must be an access type", N);
1907 return;
1908 end if;
1910 else
1911 Get_First_Interp (P, I, It);
1912 while Present (It.Nam) loop
1913 T := It.Typ;
1915 if Is_Access_Type (T) then
1916 Add_One_Interp (N, Designated_Type (T), Designated_Type (T));
1917 end if;
1919 Get_Next_Interp (I, It);
1920 end loop;
1922 -- Error if no interpretation of the prefix has an access type
1924 if Etype (N) = Any_Type then
1925 Error_Msg_N
1926 ("access type required in prefix of explicit dereference", P);
1927 Set_Etype (N, Any_Type);
1928 return;
1929 end if;
1930 end if;
1932 if Is_Function_Type
1933 and then Nkind (Parent (N)) /= N_Indexed_Component
1935 and then (Nkind (Parent (N)) /= N_Function_Call
1936 or else N /= Name (Parent (N)))
1938 and then (Nkind (Parent (N)) /= N_Procedure_Call_Statement
1939 or else N /= Name (Parent (N)))
1941 and then Nkind (Parent (N)) /= N_Subprogram_Renaming_Declaration
1942 and then (Nkind (Parent (N)) /= N_Attribute_Reference
1943 or else
1944 (Attribute_Name (Parent (N)) /= Name_Address
1945 and then
1946 Attribute_Name (Parent (N)) /= Name_Access))
1947 then
1948 -- Name is a function call with no actuals, in a context that
1949 -- requires deproceduring (including as an actual in an enclosing
1950 -- function or procedure call). There are some pathological cases
1951 -- where the prefix might include functions that return access to
1952 -- subprograms and others that return a regular type. Disambiguation
1953 -- of those has to take place in Resolve.
1955 New_N :=
1956 Make_Function_Call (Loc,
1957 Name => Make_Explicit_Dereference (Loc, P),
1958 Parameter_Associations => New_List);
1960 -- If the prefix is overloaded, remove operations that have formals,
1961 -- we know that this is a parameterless call.
1963 if Is_Overloaded (P) then
1964 Get_First_Interp (P, I, It);
1965 while Present (It.Nam) loop
1966 T := It.Typ;
1968 if No (First_Formal (Base_Type (Designated_Type (T)))) then
1969 Set_Etype (P, T);
1970 else
1971 Remove_Interp (I);
1972 end if;
1974 Get_Next_Interp (I, It);
1975 end loop;
1976 end if;
1978 Rewrite (N, New_N);
1979 Analyze (N);
1981 elsif not Is_Function_Type
1982 and then Is_Overloaded (N)
1983 then
1984 -- The prefix may include access to subprograms and other access
1985 -- types. If the context selects the interpretation that is a
1986 -- function call (not a procedure call) we cannot rewrite the node
1987 -- yet, but we include the result of the call interpretation.
1989 Get_First_Interp (N, I, It);
1990 while Present (It.Nam) loop
1991 if Ekind (Base_Type (It.Typ)) = E_Subprogram_Type
1992 and then Etype (Base_Type (It.Typ)) /= Standard_Void_Type
1993 and then Nkind (Parent (N)) /= N_Procedure_Call_Statement
1994 then
1995 Add_One_Interp (N, Etype (It.Typ), Etype (It.Typ));
1996 end if;
1998 Get_Next_Interp (I, It);
1999 end loop;
2000 end if;
2002 -- A value of remote access-to-class-wide must not be dereferenced
2003 -- (RM E.2.2(16)).
2005 Validate_Remote_Access_To_Class_Wide_Type (N);
2006 end Analyze_Explicit_Dereference;
2008 ------------------------
2009 -- Analyze_Expression --
2010 ------------------------
2012 procedure Analyze_Expression (N : Node_Id) is
2013 begin
2015 -- If the expression is an indexed component that will be rewritten
2016 -- as a container indexing, it has already been analyzed.
2018 if Nkind (N) = N_Indexed_Component
2019 and then Present (Generalized_Indexing (N))
2020 then
2021 null;
2023 else
2024 Analyze (N);
2025 Check_Parameterless_Call (N);
2026 end if;
2027 end Analyze_Expression;
2029 -------------------------------------
2030 -- Analyze_Expression_With_Actions --
2031 -------------------------------------
2033 procedure Analyze_Expression_With_Actions (N : Node_Id) is
2034 A : Node_Id;
2036 begin
2037 A := First (Actions (N));
2038 while Present (A) loop
2039 Analyze (A);
2040 Next (A);
2041 end loop;
2043 -- We currently hijack Expression_With_Actions with a VOID type and
2044 -- a NULL statement in the Expression. This will ultimately be replaced
2045 -- by a proper separate N_Compound_Statement node, at which point the
2046 -- test below can go away???
2048 if Nkind (Expression (N)) = N_Null_Statement then
2049 Set_Etype (N, Standard_Void_Type);
2050 else
2051 Analyze_Expression (Expression (N));
2052 Set_Etype (N, Etype (Expression (N)));
2053 end if;
2054 end Analyze_Expression_With_Actions;
2056 ---------------------------
2057 -- Analyze_If_Expression --
2058 ---------------------------
2060 procedure Analyze_If_Expression (N : Node_Id) is
2061 Condition : constant Node_Id := First (Expressions (N));
2062 Then_Expr : constant Node_Id := Next (Condition);
2063 Else_Expr : Node_Id;
2065 begin
2066 -- Defend against error of missing expressions from previous error
2068 if No (Then_Expr) then
2069 Check_Error_Detected;
2070 return;
2071 end if;
2073 if Comes_From_Source (N) then
2074 Check_SPARK_Restriction ("if expression is not allowed", N);
2075 end if;
2077 Else_Expr := Next (Then_Expr);
2079 if Comes_From_Source (N) then
2080 Check_Compiler_Unit (N);
2081 end if;
2083 Analyze_Expression (Condition);
2084 Analyze_Expression (Then_Expr);
2086 if Present (Else_Expr) then
2087 Analyze_Expression (Else_Expr);
2088 end if;
2090 -- If then expression not overloaded, then that decides the type
2092 if not Is_Overloaded (Then_Expr) then
2093 Set_Etype (N, Etype (Then_Expr));
2095 -- Case where then expression is overloaded
2097 else
2098 declare
2099 I : Interp_Index;
2100 It : Interp;
2102 begin
2103 Set_Etype (N, Any_Type);
2105 -- Shouldn't the following statement be down in the ELSE of the
2106 -- following loop? ???
2108 Get_First_Interp (Then_Expr, I, It);
2110 -- if no Else_Expression the conditional must be boolean
2112 if No (Else_Expr) then
2113 Set_Etype (N, Standard_Boolean);
2115 -- Else_Expression Present. For each possible intepretation of
2116 -- the Then_Expression, add it only if the Else_Expression has
2117 -- a compatible type.
2119 else
2120 while Present (It.Nam) loop
2121 if Has_Compatible_Type (Else_Expr, It.Typ) then
2122 Add_One_Interp (N, It.Typ, It.Typ);
2123 end if;
2125 Get_Next_Interp (I, It);
2126 end loop;
2127 end if;
2128 end;
2129 end if;
2130 end Analyze_If_Expression;
2132 ------------------------------------
2133 -- Analyze_Indexed_Component_Form --
2134 ------------------------------------
2136 procedure Analyze_Indexed_Component_Form (N : Node_Id) is
2137 P : constant Node_Id := Prefix (N);
2138 Exprs : constant List_Id := Expressions (N);
2139 Exp : Node_Id;
2140 P_T : Entity_Id;
2141 E : Node_Id;
2142 U_N : Entity_Id;
2144 procedure Process_Function_Call;
2145 -- Prefix in indexed component form is an overloadable entity,
2146 -- so the node is a function call. Reformat it as such.
2148 procedure Process_Indexed_Component;
2149 -- Prefix in indexed component form is actually an indexed component.
2150 -- This routine processes it, knowing that the prefix is already
2151 -- resolved.
2153 procedure Process_Indexed_Component_Or_Slice;
2154 -- An indexed component with a single index may designate a slice if
2155 -- the index is a subtype mark. This routine disambiguates these two
2156 -- cases by resolving the prefix to see if it is a subtype mark.
2158 procedure Process_Overloaded_Indexed_Component;
2159 -- If the prefix of an indexed component is overloaded, the proper
2160 -- interpretation is selected by the index types and the context.
2162 ---------------------------
2163 -- Process_Function_Call --
2164 ---------------------------
2166 procedure Process_Function_Call is
2167 Actual : Node_Id;
2169 begin
2170 Change_Node (N, N_Function_Call);
2171 Set_Name (N, P);
2172 Set_Parameter_Associations (N, Exprs);
2174 -- Analyze actuals prior to analyzing the call itself
2176 Actual := First (Parameter_Associations (N));
2177 while Present (Actual) loop
2178 Analyze (Actual);
2179 Check_Parameterless_Call (Actual);
2181 -- Move to next actual. Note that we use Next, not Next_Actual
2182 -- here. The reason for this is a bit subtle. If a function call
2183 -- includes named associations, the parser recognizes the node as
2184 -- a call, and it is analyzed as such. If all associations are
2185 -- positional, the parser builds an indexed_component node, and
2186 -- it is only after analysis of the prefix that the construct
2187 -- is recognized as a call, in which case Process_Function_Call
2188 -- rewrites the node and analyzes the actuals. If the list of
2189 -- actuals is malformed, the parser may leave the node as an
2190 -- indexed component (despite the presence of named associations).
2191 -- The iterator Next_Actual is equivalent to Next if the list is
2192 -- positional, but follows the normalized chain of actuals when
2193 -- named associations are present. In this case normalization has
2194 -- not taken place, and actuals remain unanalyzed, which leads to
2195 -- subsequent crashes or loops if there is an attempt to continue
2196 -- analysis of the program.
2198 Next (Actual);
2199 end loop;
2201 Analyze_Call (N);
2202 end Process_Function_Call;
2204 -------------------------------
2205 -- Process_Indexed_Component --
2206 -------------------------------
2208 procedure Process_Indexed_Component is
2209 Exp : Node_Id;
2210 Array_Type : Entity_Id;
2211 Index : Node_Id;
2212 Pent : Entity_Id := Empty;
2214 begin
2215 Exp := First (Exprs);
2217 if Is_Overloaded (P) then
2218 Process_Overloaded_Indexed_Component;
2220 else
2221 Array_Type := Etype (P);
2223 if Is_Entity_Name (P) then
2224 Pent := Entity (P);
2225 elsif Nkind (P) = N_Selected_Component
2226 and then Is_Entity_Name (Selector_Name (P))
2227 then
2228 Pent := Entity (Selector_Name (P));
2229 end if;
2231 -- Prefix must be appropriate for an array type, taking into
2232 -- account a possible implicit dereference.
2234 if Is_Access_Type (Array_Type) then
2235 Error_Msg_NW
2236 (Warn_On_Dereference, "?d?implicit dereference", N);
2237 Array_Type := Process_Implicit_Dereference_Prefix (Pent, P);
2238 end if;
2240 if Is_Array_Type (Array_Type) then
2241 null;
2243 elsif Present (Pent) and then Ekind (Pent) = E_Entry_Family then
2244 Analyze (Exp);
2245 Set_Etype (N, Any_Type);
2247 if not Has_Compatible_Type
2248 (Exp, Entry_Index_Type (Pent))
2249 then
2250 Error_Msg_N ("invalid index type in entry name", N);
2252 elsif Present (Next (Exp)) then
2253 Error_Msg_N ("too many subscripts in entry reference", N);
2255 else
2256 Set_Etype (N, Etype (P));
2257 end if;
2259 return;
2261 elsif Is_Record_Type (Array_Type)
2262 and then Remote_AST_I_Dereference (P)
2263 then
2264 return;
2266 elsif Try_Container_Indexing (N, P, Exprs) then
2267 return;
2269 elsif Array_Type = Any_Type then
2270 Set_Etype (N, Any_Type);
2272 -- In most cases the analysis of the prefix will have emitted
2273 -- an error already, but if the prefix may be interpreted as a
2274 -- call in prefixed notation, the report is left to the caller.
2275 -- To prevent cascaded errors, report only if no previous ones.
2277 if Serious_Errors_Detected = 0 then
2278 Error_Msg_N ("invalid prefix in indexed component", P);
2280 if Nkind (P) = N_Expanded_Name then
2281 Error_Msg_NE ("\& is not visible", P, Selector_Name (P));
2282 end if;
2283 end if;
2285 return;
2287 -- Here we definitely have a bad indexing
2289 else
2290 if Nkind (Parent (N)) = N_Requeue_Statement
2291 and then Present (Pent) and then Ekind (Pent) = E_Entry
2292 then
2293 Error_Msg_N
2294 ("REQUEUE does not permit parameters", First (Exprs));
2296 elsif Is_Entity_Name (P)
2297 and then Etype (P) = Standard_Void_Type
2298 then
2299 Error_Msg_NE ("incorrect use of&", P, Entity (P));
2301 else
2302 Error_Msg_N ("array type required in indexed component", P);
2303 end if;
2305 Set_Etype (N, Any_Type);
2306 return;
2307 end if;
2309 Index := First_Index (Array_Type);
2310 while Present (Index) and then Present (Exp) loop
2311 if not Has_Compatible_Type (Exp, Etype (Index)) then
2312 Wrong_Type (Exp, Etype (Index));
2313 Set_Etype (N, Any_Type);
2314 return;
2315 end if;
2317 Next_Index (Index);
2318 Next (Exp);
2319 end loop;
2321 Set_Etype (N, Component_Type (Array_Type));
2322 Check_Implicit_Dereference (N, Etype (N));
2324 if Present (Index) then
2325 Error_Msg_N
2326 ("too few subscripts in array reference", First (Exprs));
2328 elsif Present (Exp) then
2329 Error_Msg_N ("too many subscripts in array reference", Exp);
2330 end if;
2331 end if;
2332 end Process_Indexed_Component;
2334 ----------------------------------------
2335 -- Process_Indexed_Component_Or_Slice --
2336 ----------------------------------------
2338 procedure Process_Indexed_Component_Or_Slice is
2339 begin
2340 Exp := First (Exprs);
2341 while Present (Exp) loop
2342 Analyze_Expression (Exp);
2343 Next (Exp);
2344 end loop;
2346 Exp := First (Exprs);
2348 -- If one index is present, and it is a subtype name, then the
2349 -- node denotes a slice (note that the case of an explicit range
2350 -- for a slice was already built as an N_Slice node in the first
2351 -- place, so that case is not handled here).
2353 -- We use a replace rather than a rewrite here because this is one
2354 -- of the cases in which the tree built by the parser is plain wrong.
2356 if No (Next (Exp))
2357 and then Is_Entity_Name (Exp)
2358 and then Is_Type (Entity (Exp))
2359 then
2360 Replace (N,
2361 Make_Slice (Sloc (N),
2362 Prefix => P,
2363 Discrete_Range => New_Copy (Exp)));
2364 Analyze (N);
2366 -- Otherwise (more than one index present, or single index is not
2367 -- a subtype name), then we have the indexed component case.
2369 else
2370 Process_Indexed_Component;
2371 end if;
2372 end Process_Indexed_Component_Or_Slice;
2374 ------------------------------------------
2375 -- Process_Overloaded_Indexed_Component --
2376 ------------------------------------------
2378 procedure Process_Overloaded_Indexed_Component is
2379 Exp : Node_Id;
2380 I : Interp_Index;
2381 It : Interp;
2382 Typ : Entity_Id;
2383 Index : Node_Id;
2384 Found : Boolean;
2386 begin
2387 Set_Etype (N, Any_Type);
2389 Get_First_Interp (P, I, It);
2390 while Present (It.Nam) loop
2391 Typ := It.Typ;
2393 if Is_Access_Type (Typ) then
2394 Typ := Designated_Type (Typ);
2395 Error_Msg_NW
2396 (Warn_On_Dereference, "?d?implicit dereference", N);
2397 end if;
2399 if Is_Array_Type (Typ) then
2401 -- Got a candidate: verify that index types are compatible
2403 Index := First_Index (Typ);
2404 Found := True;
2405 Exp := First (Exprs);
2406 while Present (Index) and then Present (Exp) loop
2407 if Has_Compatible_Type (Exp, Etype (Index)) then
2408 null;
2409 else
2410 Found := False;
2411 Remove_Interp (I);
2412 exit;
2413 end if;
2415 Next_Index (Index);
2416 Next (Exp);
2417 end loop;
2419 if Found and then No (Index) and then No (Exp) then
2420 declare
2421 CT : constant Entity_Id :=
2422 Base_Type (Component_Type (Typ));
2423 begin
2424 Add_One_Interp (N, CT, CT);
2425 Check_Implicit_Dereference (N, CT);
2426 end;
2427 end if;
2429 elsif Try_Container_Indexing (N, P, Exprs) then
2430 return;
2432 end if;
2434 Get_Next_Interp (I, It);
2435 end loop;
2437 if Etype (N) = Any_Type then
2438 Error_Msg_N ("no legal interpretation for indexed component", N);
2439 Set_Is_Overloaded (N, False);
2440 end if;
2442 End_Interp_List;
2443 end Process_Overloaded_Indexed_Component;
2445 -- Start of processing for Analyze_Indexed_Component_Form
2447 begin
2448 -- Get name of array, function or type
2450 Analyze (P);
2452 -- If P is an explicit dereference whose prefix is of a remote access-
2453 -- to-subprogram type, then N has already been rewritten as a subprogram
2454 -- call and analyzed.
2456 if Nkind (N) in N_Subprogram_Call then
2457 return;
2459 -- When the prefix is attribute 'Loop_Entry and the sole expression of
2460 -- the indexed component denotes a loop name, the indexed form is turned
2461 -- into an attribute reference.
2463 elsif Nkind (N) = N_Attribute_Reference
2464 and then Attribute_Name (N) = Name_Loop_Entry
2465 then
2466 return;
2467 end if;
2469 pragma Assert (Nkind (N) = N_Indexed_Component);
2471 P_T := Base_Type (Etype (P));
2473 if Is_Entity_Name (P) and then Present (Entity (P)) then
2474 U_N := Entity (P);
2476 if Is_Type (U_N) then
2478 -- Reformat node as a type conversion
2480 E := Remove_Head (Exprs);
2482 if Present (First (Exprs)) then
2483 Error_Msg_N
2484 ("argument of type conversion must be single expression", N);
2485 end if;
2487 Change_Node (N, N_Type_Conversion);
2488 Set_Subtype_Mark (N, P);
2489 Set_Etype (N, U_N);
2490 Set_Expression (N, E);
2492 -- After changing the node, call for the specific Analysis
2493 -- routine directly, to avoid a double call to the expander.
2495 Analyze_Type_Conversion (N);
2496 return;
2497 end if;
2499 if Is_Overloadable (U_N) then
2500 Process_Function_Call;
2502 elsif Ekind (Etype (P)) = E_Subprogram_Type
2503 or else (Is_Access_Type (Etype (P))
2504 and then
2505 Ekind (Designated_Type (Etype (P))) =
2506 E_Subprogram_Type)
2507 then
2508 -- Call to access_to-subprogram with possible implicit dereference
2510 Process_Function_Call;
2512 elsif Is_Generic_Subprogram (U_N) then
2514 -- A common beginner's (or C++ templates fan) error
2516 Error_Msg_N ("generic subprogram cannot be called", N);
2517 Set_Etype (N, Any_Type);
2518 return;
2520 else
2521 Process_Indexed_Component_Or_Slice;
2522 end if;
2524 -- If not an entity name, prefix is an expression that may denote
2525 -- an array or an access-to-subprogram.
2527 else
2528 if Ekind (P_T) = E_Subprogram_Type
2529 or else (Is_Access_Type (P_T)
2530 and then
2531 Ekind (Designated_Type (P_T)) = E_Subprogram_Type)
2532 then
2533 Process_Function_Call;
2535 elsif Nkind (P) = N_Selected_Component
2536 and then Present (Entity (Selector_Name (P)))
2537 and then Is_Overloadable (Entity (Selector_Name (P)))
2538 then
2539 Process_Function_Call;
2541 -- In ASIS mode within a generic, a prefixed call is analyzed and
2542 -- partially rewritten but the original indexed component has not
2543 -- yet been rewritten as a call. Perform the replacement now.
2545 elsif Nkind (P) = N_Selected_Component
2546 and then Nkind (Parent (P)) = N_Function_Call
2547 and then ASIS_Mode
2548 then
2549 Rewrite (N, Parent (P));
2550 Analyze (N);
2552 else
2553 -- Indexed component, slice, or a call to a member of a family
2554 -- entry, which will be converted to an entry call later.
2556 Process_Indexed_Component_Or_Slice;
2557 end if;
2558 end if;
2560 Analyze_Dimension (N);
2561 end Analyze_Indexed_Component_Form;
2563 ------------------------
2564 -- Analyze_Logical_Op --
2565 ------------------------
2567 procedure Analyze_Logical_Op (N : Node_Id) is
2568 L : constant Node_Id := Left_Opnd (N);
2569 R : constant Node_Id := Right_Opnd (N);
2570 Op_Id : Entity_Id := Entity (N);
2572 begin
2573 Set_Etype (N, Any_Type);
2574 Candidate_Type := Empty;
2576 Analyze_Expression (L);
2577 Analyze_Expression (R);
2579 if Present (Op_Id) then
2581 if Ekind (Op_Id) = E_Operator then
2582 Find_Boolean_Types (L, R, Op_Id, N);
2583 else
2584 Add_One_Interp (N, Op_Id, Etype (Op_Id));
2585 end if;
2587 else
2588 Op_Id := Get_Name_Entity_Id (Chars (N));
2589 while Present (Op_Id) loop
2590 if Ekind (Op_Id) = E_Operator then
2591 Find_Boolean_Types (L, R, Op_Id, N);
2592 else
2593 Analyze_User_Defined_Binary_Op (N, Op_Id);
2594 end if;
2596 Op_Id := Homonym (Op_Id);
2597 end loop;
2598 end if;
2600 Operator_Check (N);
2601 end Analyze_Logical_Op;
2603 ---------------------------
2604 -- Analyze_Membership_Op --
2605 ---------------------------
2607 procedure Analyze_Membership_Op (N : Node_Id) is
2608 Loc : constant Source_Ptr := Sloc (N);
2609 L : constant Node_Id := Left_Opnd (N);
2610 R : constant Node_Id := Right_Opnd (N);
2612 Index : Interp_Index;
2613 It : Interp;
2614 Found : Boolean := False;
2615 I_F : Interp_Index;
2616 T_F : Entity_Id;
2618 procedure Try_One_Interp (T1 : Entity_Id);
2619 -- Routine to try one proposed interpretation. Note that the context
2620 -- of the operation plays no role in resolving the arguments, so that
2621 -- if there is more than one interpretation of the operands that is
2622 -- compatible with a membership test, the operation is ambiguous.
2624 --------------------
2625 -- Try_One_Interp --
2626 --------------------
2628 procedure Try_One_Interp (T1 : Entity_Id) is
2629 begin
2630 if Has_Compatible_Type (R, T1) then
2631 if Found
2632 and then Base_Type (T1) /= Base_Type (T_F)
2633 then
2634 It := Disambiguate (L, I_F, Index, Any_Type);
2636 if It = No_Interp then
2637 Ambiguous_Operands (N);
2638 Set_Etype (L, Any_Type);
2639 return;
2641 else
2642 T_F := It.Typ;
2643 end if;
2645 else
2646 Found := True;
2647 T_F := T1;
2648 I_F := Index;
2649 end if;
2651 Set_Etype (L, T_F);
2652 end if;
2653 end Try_One_Interp;
2655 procedure Analyze_Set_Membership;
2656 -- If a set of alternatives is present, analyze each and find the
2657 -- common type to which they must all resolve.
2659 ----------------------------
2660 -- Analyze_Set_Membership --
2661 ----------------------------
2663 procedure Analyze_Set_Membership is
2664 Alt : Node_Id;
2665 Index : Interp_Index;
2666 It : Interp;
2667 Candidate_Interps : Node_Id;
2668 Common_Type : Entity_Id := Empty;
2670 begin
2671 if Comes_From_Source (N) then
2672 Check_Compiler_Unit (N);
2673 end if;
2675 Analyze (L);
2676 Candidate_Interps := L;
2678 if not Is_Overloaded (L) then
2679 Common_Type := Etype (L);
2681 Alt := First (Alternatives (N));
2682 while Present (Alt) loop
2683 Analyze (Alt);
2685 if not Has_Compatible_Type (Alt, Common_Type) then
2686 Wrong_Type (Alt, Common_Type);
2687 end if;
2689 Next (Alt);
2690 end loop;
2692 else
2693 Alt := First (Alternatives (N));
2694 while Present (Alt) loop
2695 Analyze (Alt);
2696 if not Is_Overloaded (Alt) then
2697 Common_Type := Etype (Alt);
2699 else
2700 Get_First_Interp (Alt, Index, It);
2701 while Present (It.Typ) loop
2702 if not
2703 Has_Compatible_Type (Candidate_Interps, It.Typ)
2704 then
2705 Remove_Interp (Index);
2706 end if;
2708 Get_Next_Interp (Index, It);
2709 end loop;
2711 Get_First_Interp (Alt, Index, It);
2713 if No (It.Typ) then
2714 Error_Msg_N ("alternative has no legal type", Alt);
2715 return;
2716 end if;
2718 -- If alternative is not overloaded, we have a unique type
2719 -- for all of them.
2721 Set_Etype (Alt, It.Typ);
2722 Get_Next_Interp (Index, It);
2724 if No (It.Typ) then
2725 Set_Is_Overloaded (Alt, False);
2726 Common_Type := Etype (Alt);
2727 end if;
2729 Candidate_Interps := Alt;
2730 end if;
2732 Next (Alt);
2733 end loop;
2734 end if;
2736 Set_Etype (N, Standard_Boolean);
2738 if Present (Common_Type) then
2739 Set_Etype (L, Common_Type);
2740 Set_Is_Overloaded (L, False);
2742 else
2743 Error_Msg_N ("cannot resolve membership operation", N);
2744 end if;
2745 end Analyze_Set_Membership;
2747 -- Start of processing for Analyze_Membership_Op
2749 begin
2750 Analyze_Expression (L);
2752 if No (R) and then Ada_Version >= Ada_2012 then
2753 Analyze_Set_Membership;
2754 return;
2755 end if;
2757 if Nkind (R) = N_Range
2758 or else (Nkind (R) = N_Attribute_Reference
2759 and then Attribute_Name (R) = Name_Range)
2760 then
2761 Analyze (R);
2763 if not Is_Overloaded (L) then
2764 Try_One_Interp (Etype (L));
2766 else
2767 Get_First_Interp (L, Index, It);
2768 while Present (It.Typ) loop
2769 Try_One_Interp (It.Typ);
2770 Get_Next_Interp (Index, It);
2771 end loop;
2772 end if;
2774 -- If not a range, it can be a subtype mark, or else it is a degenerate
2775 -- membership test with a singleton value, i.e. a test for equality,
2776 -- if the types are compatible.
2778 else
2779 Analyze (R);
2781 if Is_Entity_Name (R)
2782 and then Is_Type (Entity (R))
2783 then
2784 Find_Type (R);
2785 Check_Fully_Declared (Entity (R), R);
2787 elsif Ada_Version >= Ada_2012
2788 and then Has_Compatible_Type (R, Etype (L))
2789 then
2790 if Nkind (N) = N_In then
2791 Rewrite (N,
2792 Make_Op_Eq (Loc,
2793 Left_Opnd => L,
2794 Right_Opnd => R));
2795 else
2796 Rewrite (N,
2797 Make_Op_Ne (Loc,
2798 Left_Opnd => L,
2799 Right_Opnd => R));
2800 end if;
2802 Analyze (N);
2803 return;
2805 else
2806 -- In all versions of the language, if we reach this point there
2807 -- is a previous error that will be diagnosed below.
2809 Find_Type (R);
2810 end if;
2811 end if;
2813 -- Compatibility between expression and subtype mark or range is
2814 -- checked during resolution. The result of the operation is Boolean
2815 -- in any case.
2817 Set_Etype (N, Standard_Boolean);
2819 if Comes_From_Source (N)
2820 and then Present (Right_Opnd (N))
2821 and then Is_CPP_Class (Etype (Etype (Right_Opnd (N))))
2822 then
2823 Error_Msg_N ("membership test not applicable to cpp-class types", N);
2824 end if;
2825 end Analyze_Membership_Op;
2827 -----------------
2828 -- Analyze_Mod --
2829 -----------------
2831 procedure Analyze_Mod (N : Node_Id) is
2832 begin
2833 -- A special warning check, if we have an expression of the form:
2834 -- expr mod 2 * literal
2835 -- where literal is 64 or less, then probably what was meant was
2836 -- expr mod 2 ** literal
2837 -- so issue an appropriate warning.
2839 if Warn_On_Suspicious_Modulus_Value
2840 and then Nkind (Right_Opnd (N)) = N_Integer_Literal
2841 and then Intval (Right_Opnd (N)) = Uint_2
2842 and then Nkind (Parent (N)) = N_Op_Multiply
2843 and then Nkind (Right_Opnd (Parent (N))) = N_Integer_Literal
2844 and then Intval (Right_Opnd (Parent (N))) <= Uint_64
2845 then
2846 Error_Msg_N
2847 ("suspicious MOD value, was '*'* intended'??M?", Parent (N));
2848 end if;
2850 -- Remaining processing is same as for other arithmetic operators
2852 Analyze_Arithmetic_Op (N);
2853 end Analyze_Mod;
2855 ----------------------
2856 -- Analyze_Negation --
2857 ----------------------
2859 procedure Analyze_Negation (N : Node_Id) is
2860 R : constant Node_Id := Right_Opnd (N);
2861 Op_Id : Entity_Id := Entity (N);
2863 begin
2864 Set_Etype (N, Any_Type);
2865 Candidate_Type := Empty;
2867 Analyze_Expression (R);
2869 if Present (Op_Id) then
2870 if Ekind (Op_Id) = E_Operator then
2871 Find_Negation_Types (R, Op_Id, N);
2872 else
2873 Add_One_Interp (N, Op_Id, Etype (Op_Id));
2874 end if;
2876 else
2877 Op_Id := Get_Name_Entity_Id (Chars (N));
2878 while Present (Op_Id) loop
2879 if Ekind (Op_Id) = E_Operator then
2880 Find_Negation_Types (R, Op_Id, N);
2881 else
2882 Analyze_User_Defined_Unary_Op (N, Op_Id);
2883 end if;
2885 Op_Id := Homonym (Op_Id);
2886 end loop;
2887 end if;
2889 Operator_Check (N);
2890 end Analyze_Negation;
2892 ------------------
2893 -- Analyze_Null --
2894 ------------------
2896 procedure Analyze_Null (N : Node_Id) is
2897 begin
2898 Check_SPARK_Restriction ("null is not allowed", N);
2900 Set_Etype (N, Any_Access);
2901 end Analyze_Null;
2903 ----------------------
2904 -- Analyze_One_Call --
2905 ----------------------
2907 procedure Analyze_One_Call
2908 (N : Node_Id;
2909 Nam : Entity_Id;
2910 Report : Boolean;
2911 Success : out Boolean;
2912 Skip_First : Boolean := False)
2914 Actuals : constant List_Id := Parameter_Associations (N);
2915 Prev_T : constant Entity_Id := Etype (N);
2917 Must_Skip : constant Boolean := Skip_First
2918 or else Nkind (Original_Node (N)) = N_Selected_Component
2919 or else
2920 (Nkind (Original_Node (N)) = N_Indexed_Component
2921 and then Nkind (Prefix (Original_Node (N)))
2922 = N_Selected_Component);
2923 -- The first formal must be omitted from the match when trying to find
2924 -- a primitive operation that is a possible interpretation, and also
2925 -- after the call has been rewritten, because the corresponding actual
2926 -- is already known to be compatible, and because this may be an
2927 -- indexing of a call with default parameters.
2929 Formal : Entity_Id;
2930 Actual : Node_Id;
2931 Is_Indexed : Boolean := False;
2932 Is_Indirect : Boolean := False;
2933 Subp_Type : constant Entity_Id := Etype (Nam);
2934 Norm_OK : Boolean;
2936 function Operator_Hidden_By (Fun : Entity_Id) return Boolean;
2937 -- There may be a user-defined operator that hides the current
2938 -- interpretation. We must check for this independently of the
2939 -- analysis of the call with the user-defined operation, because
2940 -- the parameter names may be wrong and yet the hiding takes place.
2941 -- This fixes a problem with ACATS test B34014O.
2943 -- When the type Address is a visible integer type, and the DEC
2944 -- system extension is visible, the predefined operator may be
2945 -- hidden as well, by one of the address operations in auxdec.
2946 -- Finally, The abstract operations on address do not hide the
2947 -- predefined operator (this is the purpose of making them abstract).
2949 procedure Indicate_Name_And_Type;
2950 -- If candidate interpretation matches, indicate name and type of
2951 -- result on call node.
2953 ----------------------------
2954 -- Indicate_Name_And_Type --
2955 ----------------------------
2957 procedure Indicate_Name_And_Type is
2958 begin
2959 Add_One_Interp (N, Nam, Etype (Nam));
2960 Check_Implicit_Dereference (N, Etype (Nam));
2961 Success := True;
2963 -- If the prefix of the call is a name, indicate the entity
2964 -- being called. If it is not a name, it is an expression that
2965 -- denotes an access to subprogram or else an entry or family. In
2966 -- the latter case, the name is a selected component, and the entity
2967 -- being called is noted on the selector.
2969 if not Is_Type (Nam) then
2970 if Is_Entity_Name (Name (N)) then
2971 Set_Entity (Name (N), Nam);
2973 elsif Nkind (Name (N)) = N_Selected_Component then
2974 Set_Entity (Selector_Name (Name (N)), Nam);
2975 end if;
2976 end if;
2978 if Debug_Flag_E and not Report then
2979 Write_Str (" Overloaded call ");
2980 Write_Int (Int (N));
2981 Write_Str (" compatible with ");
2982 Write_Int (Int (Nam));
2983 Write_Eol;
2984 end if;
2985 end Indicate_Name_And_Type;
2987 ------------------------
2988 -- Operator_Hidden_By --
2989 ------------------------
2991 function Operator_Hidden_By (Fun : Entity_Id) return Boolean is
2992 Act1 : constant Node_Id := First_Actual (N);
2993 Act2 : constant Node_Id := Next_Actual (Act1);
2994 Form1 : constant Entity_Id := First_Formal (Fun);
2995 Form2 : constant Entity_Id := Next_Formal (Form1);
2997 begin
2998 if Ekind (Fun) /= E_Function or else Is_Abstract_Subprogram (Fun) then
2999 return False;
3001 elsif not Has_Compatible_Type (Act1, Etype (Form1)) then
3002 return False;
3004 elsif Present (Form2) then
3005 if No (Act2)
3006 or else not Has_Compatible_Type (Act2, Etype (Form2))
3007 then
3008 return False;
3009 end if;
3011 elsif Present (Act2) then
3012 return False;
3013 end if;
3015 -- Now we know that the arity of the operator matches the function,
3016 -- and the function call is a valid interpretation. The function
3017 -- hides the operator if it has the right signature, or if one of
3018 -- its operands is a non-abstract operation on Address when this is
3019 -- a visible integer type.
3021 return Hides_Op (Fun, Nam)
3022 or else Is_Descendent_Of_Address (Etype (Form1))
3023 or else
3024 (Present (Form2)
3025 and then Is_Descendent_Of_Address (Etype (Form2)));
3026 end Operator_Hidden_By;
3028 -- Start of processing for Analyze_One_Call
3030 begin
3031 Success := False;
3033 -- If the subprogram has no formals or if all the formals have defaults,
3034 -- and the return type is an array type, the node may denote an indexing
3035 -- of the result of a parameterless call. In Ada 2005, the subprogram
3036 -- may have one non-defaulted formal, and the call may have been written
3037 -- in prefix notation, so that the rebuilt parameter list has more than
3038 -- one actual.
3040 if not Is_Overloadable (Nam)
3041 and then Ekind (Nam) /= E_Subprogram_Type
3042 and then Ekind (Nam) /= E_Entry_Family
3043 then
3044 return;
3045 end if;
3047 -- An indexing requires at least one actual. The name of the call cannot
3048 -- be an implicit indirect call, so it cannot be a generated explicit
3049 -- dereference.
3051 if not Is_Empty_List (Actuals)
3052 and then
3053 (Needs_No_Actuals (Nam)
3054 or else
3055 (Needs_One_Actual (Nam)
3056 and then Present (Next_Actual (First (Actuals)))))
3057 then
3058 if Is_Array_Type (Subp_Type)
3059 and then
3060 (Nkind (Name (N)) /= N_Explicit_Dereference
3061 or else Comes_From_Source (Name (N)))
3062 then
3063 Is_Indexed := Try_Indexed_Call (N, Nam, Subp_Type, Must_Skip);
3065 elsif Is_Access_Type (Subp_Type)
3066 and then Is_Array_Type (Designated_Type (Subp_Type))
3067 then
3068 Is_Indexed :=
3069 Try_Indexed_Call
3070 (N, Nam, Designated_Type (Subp_Type), Must_Skip);
3072 -- The prefix can also be a parameterless function that returns an
3073 -- access to subprogram, in which case this is an indirect call.
3074 -- If this succeeds, an explicit dereference is added later on,
3075 -- in Analyze_Call or Resolve_Call.
3077 elsif Is_Access_Type (Subp_Type)
3078 and then Ekind (Designated_Type (Subp_Type)) = E_Subprogram_Type
3079 then
3080 Is_Indirect := Try_Indirect_Call (N, Nam, Subp_Type);
3081 end if;
3083 end if;
3085 -- If the call has been transformed into a slice, it is of the form
3086 -- F (Subtype) where F is parameterless. The node has been rewritten in
3087 -- Try_Indexed_Call and there is nothing else to do.
3089 if Is_Indexed
3090 and then Nkind (N) = N_Slice
3091 then
3092 return;
3093 end if;
3095 Normalize_Actuals
3096 (N, Nam, (Report and not Is_Indexed and not Is_Indirect), Norm_OK);
3098 if not Norm_OK then
3100 -- If an indirect call is a possible interpretation, indicate
3101 -- success to the caller. This may be an indexing of an explicit
3102 -- dereference of a call that returns an access type (see above).
3104 if Is_Indirect
3105 or else (Is_Indexed
3106 and then Nkind (Name (N)) = N_Explicit_Dereference
3107 and then Comes_From_Source (Name (N)))
3108 then
3109 Success := True;
3110 return;
3112 -- Mismatch in number or names of parameters
3114 elsif Debug_Flag_E then
3115 Write_Str (" normalization fails in call ");
3116 Write_Int (Int (N));
3117 Write_Str (" with subprogram ");
3118 Write_Int (Int (Nam));
3119 Write_Eol;
3120 end if;
3122 -- If the context expects a function call, discard any interpretation
3123 -- that is a procedure. If the node is not overloaded, leave as is for
3124 -- better error reporting when type mismatch is found.
3126 elsif Nkind (N) = N_Function_Call
3127 and then Is_Overloaded (Name (N))
3128 and then Ekind (Nam) = E_Procedure
3129 then
3130 return;
3132 -- Ditto for function calls in a procedure context
3134 elsif Nkind (N) = N_Procedure_Call_Statement
3135 and then Is_Overloaded (Name (N))
3136 and then Etype (Nam) /= Standard_Void_Type
3137 then
3138 return;
3140 elsif No (Actuals) then
3142 -- If Normalize succeeds, then there are default parameters for
3143 -- all formals.
3145 Indicate_Name_And_Type;
3147 elsif Ekind (Nam) = E_Operator then
3148 if Nkind (N) = N_Procedure_Call_Statement then
3149 return;
3150 end if;
3152 -- This can occur when the prefix of the call is an operator
3153 -- name or an expanded name whose selector is an operator name.
3155 Analyze_Operator_Call (N, Nam);
3157 if Etype (N) /= Prev_T then
3159 -- Check that operator is not hidden by a function interpretation
3161 if Is_Overloaded (Name (N)) then
3162 declare
3163 I : Interp_Index;
3164 It : Interp;
3166 begin
3167 Get_First_Interp (Name (N), I, It);
3168 while Present (It.Nam) loop
3169 if Operator_Hidden_By (It.Nam) then
3170 Set_Etype (N, Prev_T);
3171 return;
3172 end if;
3174 Get_Next_Interp (I, It);
3175 end loop;
3176 end;
3177 end if;
3179 -- If operator matches formals, record its name on the call.
3180 -- If the operator is overloaded, Resolve will select the
3181 -- correct one from the list of interpretations. The call
3182 -- node itself carries the first candidate.
3184 Set_Entity (Name (N), Nam);
3185 Success := True;
3187 elsif Report and then Etype (N) = Any_Type then
3188 Error_Msg_N ("incompatible arguments for operator", N);
3189 end if;
3191 else
3192 -- Normalize_Actuals has chained the named associations in the
3193 -- correct order of the formals.
3195 Actual := First_Actual (N);
3196 Formal := First_Formal (Nam);
3198 -- If we are analyzing a call rewritten from object notation, skip
3199 -- first actual, which may be rewritten later as an explicit
3200 -- dereference.
3202 if Must_Skip then
3203 Next_Actual (Actual);
3204 Next_Formal (Formal);
3205 end if;
3207 while Present (Actual) and then Present (Formal) loop
3208 if Nkind (Parent (Actual)) /= N_Parameter_Association
3209 or else Chars (Selector_Name (Parent (Actual))) = Chars (Formal)
3210 then
3211 -- The actual can be compatible with the formal, but we must
3212 -- also check that the context is not an address type that is
3213 -- visibly an integer type, as is the case in VMS_64. In this
3214 -- case the use of literals is illegal, except in the body of
3215 -- descendents of system, where arithmetic operations on
3216 -- address are of course used.
3218 if Has_Compatible_Type (Actual, Etype (Formal))
3219 and then
3220 (Etype (Actual) /= Universal_Integer
3221 or else not Is_Descendent_Of_Address (Etype (Formal))
3222 or else
3223 Is_Predefined_File_Name
3224 (Unit_File_Name (Get_Source_Unit (N))))
3225 then
3226 Next_Actual (Actual);
3227 Next_Formal (Formal);
3229 -- In Allow_Integer_Address mode, we allow an actual integer to
3230 -- match a formal address type and vice versa. We only do this
3231 -- if we are certain that an error will otherwise be issued
3233 elsif Address_Integer_Convert_OK
3234 (Etype (Actual), Etype (Formal))
3235 and then (Report and not Is_Indexed and not Is_Indirect)
3236 then
3237 -- Handle this case by introducing an unchecked conversion
3239 Rewrite (Actual,
3240 Unchecked_Convert_To (Etype (Formal),
3241 Relocate_Node (Actual)));
3242 Analyze_And_Resolve (Actual, Etype (Formal));
3243 Next_Actual (Actual);
3244 Next_Formal (Formal);
3246 else
3247 if Debug_Flag_E then
3248 Write_Str (" type checking fails in call ");
3249 Write_Int (Int (N));
3250 Write_Str (" with formal ");
3251 Write_Int (Int (Formal));
3252 Write_Str (" in subprogram ");
3253 Write_Int (Int (Nam));
3254 Write_Eol;
3255 end if;
3257 -- Comment needed on the following test???
3259 if Report and not Is_Indexed and not Is_Indirect then
3261 -- Ada 2005 (AI-251): Complete the error notification
3262 -- to help new Ada 2005 users.
3264 if Is_Class_Wide_Type (Etype (Formal))
3265 and then Is_Interface (Etype (Etype (Formal)))
3266 and then not Interface_Present_In_Ancestor
3267 (Typ => Etype (Actual),
3268 Iface => Etype (Etype (Formal)))
3269 then
3270 Error_Msg_NE
3271 ("(Ada 2005) does not implement interface }",
3272 Actual, Etype (Etype (Formal)));
3273 end if;
3275 Wrong_Type (Actual, Etype (Formal));
3277 if Nkind (Actual) = N_Op_Eq
3278 and then Nkind (Left_Opnd (Actual)) = N_Identifier
3279 then
3280 Formal := First_Formal (Nam);
3281 while Present (Formal) loop
3282 if Chars (Left_Opnd (Actual)) = Chars (Formal) then
3283 Error_Msg_N -- CODEFIX
3284 ("possible misspelling of `='>`!", Actual);
3285 exit;
3286 end if;
3288 Next_Formal (Formal);
3289 end loop;
3290 end if;
3292 if All_Errors_Mode then
3293 Error_Msg_Sloc := Sloc (Nam);
3295 if Etype (Formal) = Any_Type then
3296 Error_Msg_N
3297 ("there is no legal actual parameter", Actual);
3298 end if;
3300 if Is_Overloadable (Nam)
3301 and then Present (Alias (Nam))
3302 and then not Comes_From_Source (Nam)
3303 then
3304 Error_Msg_NE
3305 ("\\ =='> in call to inherited operation & #!",
3306 Actual, Nam);
3308 elsif Ekind (Nam) = E_Subprogram_Type then
3309 declare
3310 Access_To_Subprogram_Typ :
3311 constant Entity_Id :=
3312 Defining_Identifier
3313 (Associated_Node_For_Itype (Nam));
3314 begin
3315 Error_Msg_NE
3316 ("\\ =='> in call to dereference of &#!",
3317 Actual, Access_To_Subprogram_Typ);
3318 end;
3320 else
3321 Error_Msg_NE
3322 ("\\ =='> in call to &#!", Actual, Nam);
3324 end if;
3325 end if;
3326 end if;
3328 return;
3329 end if;
3331 else
3332 -- Normalize_Actuals has verified that a default value exists
3333 -- for this formal. Current actual names a subsequent formal.
3335 Next_Formal (Formal);
3336 end if;
3337 end loop;
3339 -- On exit, all actuals match
3341 Indicate_Name_And_Type;
3342 end if;
3343 end Analyze_One_Call;
3345 ---------------------------
3346 -- Analyze_Operator_Call --
3347 ---------------------------
3349 procedure Analyze_Operator_Call (N : Node_Id; Op_Id : Entity_Id) is
3350 Op_Name : constant Name_Id := Chars (Op_Id);
3351 Act1 : constant Node_Id := First_Actual (N);
3352 Act2 : constant Node_Id := Next_Actual (Act1);
3354 begin
3355 -- Binary operator case
3357 if Present (Act2) then
3359 -- If more than two operands, then not binary operator after all
3361 if Present (Next_Actual (Act2)) then
3362 return;
3363 end if;
3365 -- Otherwise action depends on operator
3367 case Op_Name is
3368 when Name_Op_Add |
3369 Name_Op_Subtract |
3370 Name_Op_Multiply |
3371 Name_Op_Divide |
3372 Name_Op_Mod |
3373 Name_Op_Rem |
3374 Name_Op_Expon =>
3375 Find_Arithmetic_Types (Act1, Act2, Op_Id, N);
3377 when Name_Op_And |
3378 Name_Op_Or |
3379 Name_Op_Xor =>
3380 Find_Boolean_Types (Act1, Act2, Op_Id, N);
3382 when Name_Op_Lt |
3383 Name_Op_Le |
3384 Name_Op_Gt |
3385 Name_Op_Ge =>
3386 Find_Comparison_Types (Act1, Act2, Op_Id, N);
3388 when Name_Op_Eq |
3389 Name_Op_Ne =>
3390 Find_Equality_Types (Act1, Act2, Op_Id, N);
3392 when Name_Op_Concat =>
3393 Find_Concatenation_Types (Act1, Act2, Op_Id, N);
3395 -- Is this when others, or should it be an abort???
3397 when others =>
3398 null;
3399 end case;
3401 -- Unary operator case
3403 else
3404 case Op_Name is
3405 when Name_Op_Subtract |
3406 Name_Op_Add |
3407 Name_Op_Abs =>
3408 Find_Unary_Types (Act1, Op_Id, N);
3410 when Name_Op_Not =>
3411 Find_Negation_Types (Act1, Op_Id, N);
3413 -- Is this when others correct, or should it be an abort???
3415 when others =>
3416 null;
3417 end case;
3418 end if;
3419 end Analyze_Operator_Call;
3421 -------------------------------------------
3422 -- Analyze_Overloaded_Selected_Component --
3423 -------------------------------------------
3425 procedure Analyze_Overloaded_Selected_Component (N : Node_Id) is
3426 Nam : constant Node_Id := Prefix (N);
3427 Sel : constant Node_Id := Selector_Name (N);
3428 Comp : Entity_Id;
3429 I : Interp_Index;
3430 It : Interp;
3431 T : Entity_Id;
3433 begin
3434 Set_Etype (Sel, Any_Type);
3436 Get_First_Interp (Nam, I, It);
3437 while Present (It.Typ) loop
3438 if Is_Access_Type (It.Typ) then
3439 T := Designated_Type (It.Typ);
3440 Error_Msg_NW (Warn_On_Dereference, "?d?implicit dereference", N);
3441 else
3442 T := It.Typ;
3443 end if;
3445 -- Locate the component. For a private prefix the selector can denote
3446 -- a discriminant.
3448 if Is_Record_Type (T) or else Is_Private_Type (T) then
3450 -- If the prefix is a class-wide type, the visible components are
3451 -- those of the base type.
3453 if Is_Class_Wide_Type (T) then
3454 T := Etype (T);
3455 end if;
3457 Comp := First_Entity (T);
3458 while Present (Comp) loop
3459 if Chars (Comp) = Chars (Sel)
3460 and then Is_Visible_Component (Comp)
3461 then
3463 -- AI05-105: if the context is an object renaming with
3464 -- an anonymous access type, the expected type of the
3465 -- object must be anonymous. This is a name resolution rule.
3467 if Nkind (Parent (N)) /= N_Object_Renaming_Declaration
3468 or else No (Access_Definition (Parent (N)))
3469 or else Ekind (Etype (Comp)) = E_Anonymous_Access_Type
3470 or else
3471 Ekind (Etype (Comp)) = E_Anonymous_Access_Subprogram_Type
3472 then
3473 Set_Entity (Sel, Comp);
3474 Set_Etype (Sel, Etype (Comp));
3475 Add_One_Interp (N, Etype (Comp), Etype (Comp));
3476 Check_Implicit_Dereference (N, Etype (Comp));
3478 -- This also specifies a candidate to resolve the name.
3479 -- Further overloading will be resolved from context.
3480 -- The selector name itself does not carry overloading
3481 -- information.
3483 Set_Etype (Nam, It.Typ);
3485 else
3486 -- Named access type in the context of a renaming
3487 -- declaration with an access definition. Remove
3488 -- inapplicable candidate.
3490 Remove_Interp (I);
3491 end if;
3492 end if;
3494 Next_Entity (Comp);
3495 end loop;
3497 elsif Is_Concurrent_Type (T) then
3498 Comp := First_Entity (T);
3499 while Present (Comp)
3500 and then Comp /= First_Private_Entity (T)
3501 loop
3502 if Chars (Comp) = Chars (Sel) then
3503 if Is_Overloadable (Comp) then
3504 Add_One_Interp (Sel, Comp, Etype (Comp));
3505 else
3506 Set_Entity_With_Checks (Sel, Comp);
3507 Generate_Reference (Comp, Sel);
3508 end if;
3510 Set_Etype (Sel, Etype (Comp));
3511 Set_Etype (N, Etype (Comp));
3512 Set_Etype (Nam, It.Typ);
3514 -- For access type case, introduce explicit dereference for
3515 -- more uniform treatment of entry calls. Do this only once
3516 -- if several interpretations yield an access type.
3518 if Is_Access_Type (Etype (Nam))
3519 and then Nkind (Nam) /= N_Explicit_Dereference
3520 then
3521 Insert_Explicit_Dereference (Nam);
3522 Error_Msg_NW
3523 (Warn_On_Dereference, "?d?implicit dereference", N);
3524 end if;
3525 end if;
3527 Next_Entity (Comp);
3528 end loop;
3530 Set_Is_Overloaded (N, Is_Overloaded (Sel));
3531 end if;
3533 Get_Next_Interp (I, It);
3534 end loop;
3536 if Etype (N) = Any_Type
3537 and then not Try_Object_Operation (N)
3538 then
3539 Error_Msg_NE ("undefined selector& for overloaded prefix", N, Sel);
3540 Set_Entity (Sel, Any_Id);
3541 Set_Etype (Sel, Any_Type);
3542 end if;
3543 end Analyze_Overloaded_Selected_Component;
3545 ----------------------------------
3546 -- Analyze_Qualified_Expression --
3547 ----------------------------------
3549 procedure Analyze_Qualified_Expression (N : Node_Id) is
3550 Mark : constant Entity_Id := Subtype_Mark (N);
3551 Expr : constant Node_Id := Expression (N);
3552 I : Interp_Index;
3553 It : Interp;
3554 T : Entity_Id;
3556 begin
3557 Analyze_Expression (Expr);
3559 Set_Etype (N, Any_Type);
3560 Find_Type (Mark);
3561 T := Entity (Mark);
3562 Set_Etype (N, T);
3564 if T = Any_Type then
3565 return;
3566 end if;
3568 Check_Fully_Declared (T, N);
3570 -- If expected type is class-wide, check for exact match before
3571 -- expansion, because if the expression is a dispatching call it
3572 -- may be rewritten as explicit dereference with class-wide result.
3573 -- If expression is overloaded, retain only interpretations that
3574 -- will yield exact matches.
3576 if Is_Class_Wide_Type (T) then
3577 if not Is_Overloaded (Expr) then
3578 if Base_Type (Etype (Expr)) /= Base_Type (T) then
3579 if Nkind (Expr) = N_Aggregate then
3580 Error_Msg_N ("type of aggregate cannot be class-wide", Expr);
3581 else
3582 Wrong_Type (Expr, T);
3583 end if;
3584 end if;
3586 else
3587 Get_First_Interp (Expr, I, It);
3589 while Present (It.Nam) loop
3590 if Base_Type (It.Typ) /= Base_Type (T) then
3591 Remove_Interp (I);
3592 end if;
3594 Get_Next_Interp (I, It);
3595 end loop;
3596 end if;
3597 end if;
3599 Set_Etype (N, T);
3600 end Analyze_Qualified_Expression;
3602 -----------------------------------
3603 -- Analyze_Quantified_Expression --
3604 -----------------------------------
3606 procedure Analyze_Quantified_Expression (N : Node_Id) is
3607 function Is_Empty_Range (Typ : Entity_Id) return Boolean;
3608 -- If the iterator is part of a quantified expression, and the range is
3609 -- known to be statically empty, emit a warning and replace expression
3610 -- with its static value. Returns True if the replacement occurs.
3612 function No_Else_Or_Trivial_True (If_Expr : Node_Id) return Boolean;
3613 -- Determine whether if expression If_Expr lacks an else part or if it
3614 -- has one, it evaluates to True.
3616 --------------------
3617 -- Is_Empty_Range --
3618 --------------------
3620 function Is_Empty_Range (Typ : Entity_Id) return Boolean is
3621 Loc : constant Source_Ptr := Sloc (N);
3623 begin
3624 if Is_Array_Type (Typ)
3625 and then Compile_Time_Known_Bounds (Typ)
3626 and then
3627 (Expr_Value (Type_Low_Bound (Etype (First_Index (Typ)))) >
3628 Expr_Value (Type_High_Bound (Etype (First_Index (Typ)))))
3629 then
3630 Preanalyze_And_Resolve (Condition (N), Standard_Boolean);
3632 if All_Present (N) then
3633 Error_Msg_N
3634 ("??quantified expression with ALL "
3635 & "over a null range has value True", N);
3636 Rewrite (N, New_Occurrence_Of (Standard_True, Loc));
3638 else
3639 Error_Msg_N
3640 ("??quantified expression with SOME "
3641 & "over a null range has value False", N);
3642 Rewrite (N, New_Occurrence_Of (Standard_False, Loc));
3643 end if;
3645 Analyze (N);
3646 return True;
3648 else
3649 return False;
3650 end if;
3651 end Is_Empty_Range;
3653 -----------------------------
3654 -- No_Else_Or_Trivial_True --
3655 -----------------------------
3657 function No_Else_Or_Trivial_True (If_Expr : Node_Id) return Boolean is
3658 Else_Expr : constant Node_Id :=
3659 Next (Next (First (Expressions (If_Expr))));
3660 begin
3661 return
3662 No (Else_Expr)
3663 or else (Compile_Time_Known_Value (Else_Expr)
3664 and then Is_True (Expr_Value (Else_Expr)));
3665 end No_Else_Or_Trivial_True;
3667 -- Local variables
3669 Cond : constant Node_Id := Condition (N);
3670 Loop_Id : Entity_Id;
3671 QE_Scop : Entity_Id;
3673 -- Start of processing for Analyze_Quantified_Expression
3675 begin
3676 Check_SPARK_Restriction ("quantified expression is not allowed", N);
3678 -- Create a scope to emulate the loop-like behavior of the quantified
3679 -- expression. The scope is needed to provide proper visibility of the
3680 -- loop variable.
3682 QE_Scop := New_Internal_Entity (E_Loop, Current_Scope, Sloc (N), 'L');
3683 Set_Etype (QE_Scop, Standard_Void_Type);
3684 Set_Scope (QE_Scop, Current_Scope);
3685 Set_Parent (QE_Scop, N);
3687 Push_Scope (QE_Scop);
3689 -- All constituents are preanalyzed and resolved to avoid untimely
3690 -- generation of various temporaries and types. Full analysis and
3691 -- expansion is carried out when the quantified expression is
3692 -- transformed into an expression with actions.
3694 if Present (Iterator_Specification (N)) then
3695 Preanalyze (Iterator_Specification (N));
3697 -- Do not proceed with the analysis when the range of iteration is
3698 -- empty. The appropriate error is issued by Is_Empty_Range.
3700 if Is_Entity_Name (Name (Iterator_Specification (N)))
3701 and then Is_Empty_Range (Etype (Name (Iterator_Specification (N))))
3702 then
3703 return;
3704 end if;
3706 else pragma Assert (Present (Loop_Parameter_Specification (N)));
3707 declare
3708 Loop_Par : constant Node_Id := Loop_Parameter_Specification (N);
3710 begin
3711 Preanalyze (Loop_Par);
3713 if Nkind (Discrete_Subtype_Definition (Loop_Par)) = N_Function_Call
3714 and then Parent (Loop_Par) /= N
3715 then
3716 -- The parser cannot distinguish between a loop specification
3717 -- and an iterator specification. If after pre-analysis the
3718 -- proper form has been recognized, rewrite the expression to
3719 -- reflect the right kind. This is needed for proper ASIS
3720 -- navigation. If expansion is enabled, the transformation is
3721 -- performed when the expression is rewritten as a loop.
3723 Set_Iterator_Specification (N,
3724 New_Copy_Tree (Iterator_Specification (Parent (Loop_Par))));
3726 Set_Defining_Identifier (Iterator_Specification (N),
3727 Relocate_Node (Defining_Identifier (Loop_Par)));
3728 Set_Name (Iterator_Specification (N),
3729 Relocate_Node (Discrete_Subtype_Definition (Loop_Par)));
3730 Set_Comes_From_Source (Iterator_Specification (N),
3731 Comes_From_Source (Loop_Parameter_Specification (N)));
3732 Set_Loop_Parameter_Specification (N, Empty);
3733 end if;
3734 end;
3735 end if;
3737 Preanalyze_And_Resolve (Cond, Standard_Boolean);
3739 End_Scope;
3740 Set_Etype (N, Standard_Boolean);
3742 -- Verify that the loop variable is used within the condition of the
3743 -- quantified expression.
3745 if Present (Iterator_Specification (N)) then
3746 Loop_Id := Defining_Identifier (Iterator_Specification (N));
3747 else
3748 Loop_Id := Defining_Identifier (Loop_Parameter_Specification (N));
3749 end if;
3751 if Warn_On_Suspicious_Contract
3752 and then not Referenced (Loop_Id, Cond)
3753 then
3754 Error_Msg_N ("?T?unused variable &", Loop_Id);
3755 end if;
3757 -- Diagnose a possible misuse of the SOME existential quantifier. When
3758 -- we have a quantified expression of the form:
3760 -- for some X => (if P then Q [else True])
3762 -- any value for X that makes P False results in the if expression being
3763 -- trivially True, and so also results in the the quantified expression
3764 -- being trivially True.
3766 if Warn_On_Suspicious_Contract
3767 and then not All_Present (N)
3768 and then Nkind (Cond) = N_If_Expression
3769 and then No_Else_Or_Trivial_True (Cond)
3770 then
3771 Error_Msg_N ("?T?suspicious expression", N);
3772 Error_Msg_N ("\\did you mean (for all X ='> (if P then Q))", N);
3773 Error_Msg_N ("\\or (for some X ='> P and then Q) instead'?", N);
3774 end if;
3775 end Analyze_Quantified_Expression;
3777 -------------------
3778 -- Analyze_Range --
3779 -------------------
3781 procedure Analyze_Range (N : Node_Id) is
3782 L : constant Node_Id := Low_Bound (N);
3783 H : constant Node_Id := High_Bound (N);
3784 I1, I2 : Interp_Index;
3785 It1, It2 : Interp;
3787 procedure Check_Common_Type (T1, T2 : Entity_Id);
3788 -- Verify the compatibility of two types, and choose the
3789 -- non universal one if the other is universal.
3791 procedure Check_High_Bound (T : Entity_Id);
3792 -- Test one interpretation of the low bound against all those
3793 -- of the high bound.
3795 procedure Check_Universal_Expression (N : Node_Id);
3796 -- In Ada 83, reject bounds of a universal range that are not literals
3797 -- or entity names.
3799 -----------------------
3800 -- Check_Common_Type --
3801 -----------------------
3803 procedure Check_Common_Type (T1, T2 : Entity_Id) is
3804 begin
3805 if Covers (T1 => T1, T2 => T2)
3806 or else
3807 Covers (T1 => T2, T2 => T1)
3808 then
3809 if T1 = Universal_Integer
3810 or else T1 = Universal_Real
3811 or else T1 = Any_Character
3812 then
3813 Add_One_Interp (N, Base_Type (T2), Base_Type (T2));
3815 elsif T1 = T2 then
3816 Add_One_Interp (N, T1, T1);
3818 else
3819 Add_One_Interp (N, Base_Type (T1), Base_Type (T1));
3820 end if;
3821 end if;
3822 end Check_Common_Type;
3824 ----------------------
3825 -- Check_High_Bound --
3826 ----------------------
3828 procedure Check_High_Bound (T : Entity_Id) is
3829 begin
3830 if not Is_Overloaded (H) then
3831 Check_Common_Type (T, Etype (H));
3832 else
3833 Get_First_Interp (H, I2, It2);
3834 while Present (It2.Typ) loop
3835 Check_Common_Type (T, It2.Typ);
3836 Get_Next_Interp (I2, It2);
3837 end loop;
3838 end if;
3839 end Check_High_Bound;
3841 -----------------------------
3842 -- Is_Universal_Expression --
3843 -----------------------------
3845 procedure Check_Universal_Expression (N : Node_Id) is
3846 begin
3847 if Etype (N) = Universal_Integer
3848 and then Nkind (N) /= N_Integer_Literal
3849 and then not Is_Entity_Name (N)
3850 and then Nkind (N) /= N_Attribute_Reference
3851 then
3852 Error_Msg_N ("illegal bound in discrete range", N);
3853 end if;
3854 end Check_Universal_Expression;
3856 -- Start of processing for Analyze_Range
3858 begin
3859 Set_Etype (N, Any_Type);
3860 Analyze_Expression (L);
3861 Analyze_Expression (H);
3863 if Etype (L) = Any_Type or else Etype (H) = Any_Type then
3864 return;
3866 else
3867 if not Is_Overloaded (L) then
3868 Check_High_Bound (Etype (L));
3869 else
3870 Get_First_Interp (L, I1, It1);
3871 while Present (It1.Typ) loop
3872 Check_High_Bound (It1.Typ);
3873 Get_Next_Interp (I1, It1);
3874 end loop;
3875 end if;
3877 -- If result is Any_Type, then we did not find a compatible pair
3879 if Etype (N) = Any_Type then
3880 Error_Msg_N ("incompatible types in range ", N);
3881 end if;
3882 end if;
3884 if Ada_Version = Ada_83
3885 and then
3886 (Nkind (Parent (N)) = N_Loop_Parameter_Specification
3887 or else Nkind (Parent (N)) = N_Constrained_Array_Definition)
3888 then
3889 Check_Universal_Expression (L);
3890 Check_Universal_Expression (H);
3891 end if;
3893 Check_Function_Writable_Actuals (N);
3894 end Analyze_Range;
3896 -----------------------
3897 -- Analyze_Reference --
3898 -----------------------
3900 procedure Analyze_Reference (N : Node_Id) is
3901 P : constant Node_Id := Prefix (N);
3902 E : Entity_Id;
3903 T : Entity_Id;
3904 Acc_Type : Entity_Id;
3906 begin
3907 Analyze (P);
3909 -- An interesting error check, if we take the 'Reference of an object
3910 -- for which a pragma Atomic or Volatile has been given, and the type
3911 -- of the object is not Atomic or Volatile, then we are in trouble. The
3912 -- problem is that no trace of the atomic/volatile status will remain
3913 -- for the backend to respect when it deals with the resulting pointer,
3914 -- since the pointer type will not be marked atomic (it is a pointer to
3915 -- the base type of the object).
3917 -- It is not clear if that can ever occur, but in case it does, we will
3918 -- generate an error message. Not clear if this message can ever be
3919 -- generated, and pretty clear that it represents a bug if it is, still
3920 -- seems worth checking, except in CodePeer mode where we do not really
3921 -- care and don't want to bother the user.
3923 T := Etype (P);
3925 if Is_Entity_Name (P)
3926 and then Is_Object_Reference (P)
3927 and then not CodePeer_Mode
3928 then
3929 E := Entity (P);
3930 T := Etype (P);
3932 if (Has_Atomic_Components (E)
3933 and then not Has_Atomic_Components (T))
3934 or else
3935 (Has_Volatile_Components (E)
3936 and then not Has_Volatile_Components (T))
3937 or else (Is_Atomic (E) and then not Is_Atomic (T))
3938 or else (Is_Volatile (E) and then not Is_Volatile (T))
3939 then
3940 Error_Msg_N ("cannot take reference to Atomic/Volatile object", N);
3941 end if;
3942 end if;
3944 -- Carry on with normal processing
3946 Acc_Type := Create_Itype (E_Allocator_Type, N);
3947 Set_Etype (Acc_Type, Acc_Type);
3948 Set_Directly_Designated_Type (Acc_Type, Etype (P));
3949 Set_Etype (N, Acc_Type);
3950 end Analyze_Reference;
3952 --------------------------------
3953 -- Analyze_Selected_Component --
3954 --------------------------------
3956 -- Prefix is a record type or a task or protected type. In the latter case,
3957 -- the selector must denote a visible entry.
3959 procedure Analyze_Selected_Component (N : Node_Id) is
3960 Name : constant Node_Id := Prefix (N);
3961 Sel : constant Node_Id := Selector_Name (N);
3962 Act_Decl : Node_Id;
3963 Comp : Entity_Id;
3964 Has_Candidate : Boolean := False;
3965 In_Scope : Boolean;
3966 Parent_N : Node_Id;
3967 Pent : Entity_Id := Empty;
3968 Prefix_Type : Entity_Id;
3970 Type_To_Use : Entity_Id;
3971 -- In most cases this is the Prefix_Type, but if the Prefix_Type is
3972 -- a class-wide type, we use its root type, whose components are
3973 -- present in the class-wide type.
3975 Is_Single_Concurrent_Object : Boolean;
3976 -- Set True if the prefix is a single task or a single protected object
3978 procedure Find_Component_In_Instance (Rec : Entity_Id);
3979 -- In an instance, a component of a private extension may not be visible
3980 -- while it was visible in the generic. Search candidate scope for a
3981 -- component with the proper identifier. This is only done if all other
3982 -- searches have failed. If a match is found, the Etype of both N and
3983 -- Sel are set from this component, and the entity of Sel is set to
3984 -- reference this component. If no match is found, Entity (Sel) remains
3985 -- unset.
3987 function Has_Mode_Conformant_Spec (Comp : Entity_Id) return Boolean;
3988 -- It is known that the parent of N denotes a subprogram call. Comp
3989 -- is an overloadable component of the concurrent type of the prefix.
3990 -- Determine whether all formals of the parent of N and Comp are mode
3991 -- conformant. If the parent node is not analyzed yet it may be an
3992 -- indexed component rather than a function call.
3994 --------------------------------
3995 -- Find_Component_In_Instance --
3996 --------------------------------
3998 procedure Find_Component_In_Instance (Rec : Entity_Id) is
3999 Comp : Entity_Id;
4001 begin
4002 Comp := First_Component (Rec);
4003 while Present (Comp) loop
4004 if Chars (Comp) = Chars (Sel) then
4005 Set_Entity_With_Checks (Sel, Comp);
4006 Set_Etype (Sel, Etype (Comp));
4007 Set_Etype (N, Etype (Comp));
4008 return;
4009 end if;
4011 Next_Component (Comp);
4012 end loop;
4014 -- If we fall through, no match, so no changes made
4016 return;
4017 end Find_Component_In_Instance;
4019 ------------------------------
4020 -- Has_Mode_Conformant_Spec --
4021 ------------------------------
4023 function Has_Mode_Conformant_Spec (Comp : Entity_Id) return Boolean is
4024 Comp_Param : Entity_Id;
4025 Param : Node_Id;
4026 Param_Typ : Entity_Id;
4028 begin
4029 Comp_Param := First_Formal (Comp);
4031 if Nkind (Parent (N)) = N_Indexed_Component then
4032 Param := First (Expressions (Parent (N)));
4033 else
4034 Param := First (Parameter_Associations (Parent (N)));
4035 end if;
4037 while Present (Comp_Param)
4038 and then Present (Param)
4039 loop
4040 Param_Typ := Find_Parameter_Type (Param);
4042 if Present (Param_Typ)
4043 and then
4044 not Conforming_Types
4045 (Etype (Comp_Param), Param_Typ, Mode_Conformant)
4046 then
4047 return False;
4048 end if;
4050 Next_Formal (Comp_Param);
4051 Next (Param);
4052 end loop;
4054 -- One of the specs has additional formals; there is no match, unless
4055 -- this may be an indexing of a parameterless call.
4057 -- Note that when expansion is disabled, the corresponding record
4058 -- type of synchronized types is not constructed, so that there is
4059 -- no point is attempting an interpretation as a prefixed call, as
4060 -- this is bound to fail because the primitive operations will not
4061 -- be properly located.
4063 if Present (Comp_Param) or else Present (Param) then
4064 if Needs_No_Actuals (Comp)
4065 and then Is_Array_Type (Etype (Comp))
4066 and then not Expander_Active
4067 then
4068 return True;
4069 else
4070 return False;
4071 end if;
4072 end if;
4074 return True;
4075 end Has_Mode_Conformant_Spec;
4077 -- Start of processing for Analyze_Selected_Component
4079 begin
4080 Set_Etype (N, Any_Type);
4082 if Is_Overloaded (Name) then
4083 Analyze_Overloaded_Selected_Component (N);
4084 return;
4086 elsif Etype (Name) = Any_Type then
4087 Set_Entity (Sel, Any_Id);
4088 Set_Etype (Sel, Any_Type);
4089 return;
4091 else
4092 Prefix_Type := Etype (Name);
4093 end if;
4095 if Is_Access_Type (Prefix_Type) then
4097 -- A RACW object can never be used as prefix of a selected component
4098 -- since that means it is dereferenced without being a controlling
4099 -- operand of a dispatching operation (RM E.2.2(16/1)). Before
4100 -- reporting an error, we must check whether this is actually a
4101 -- dispatching call in prefix form.
4103 if Is_Remote_Access_To_Class_Wide_Type (Prefix_Type)
4104 and then Comes_From_Source (N)
4105 then
4106 if Try_Object_Operation (N) then
4107 return;
4108 else
4109 Error_Msg_N
4110 ("invalid dereference of a remote access-to-class-wide value",
4112 end if;
4114 -- Normal case of selected component applied to access type
4116 else
4117 Error_Msg_NW (Warn_On_Dereference, "?d?implicit dereference", N);
4119 if Is_Entity_Name (Name) then
4120 Pent := Entity (Name);
4121 elsif Nkind (Name) = N_Selected_Component
4122 and then Is_Entity_Name (Selector_Name (Name))
4123 then
4124 Pent := Entity (Selector_Name (Name));
4125 end if;
4127 Prefix_Type := Process_Implicit_Dereference_Prefix (Pent, Name);
4128 end if;
4130 -- If we have an explicit dereference of a remote access-to-class-wide
4131 -- value, then issue an error (see RM-E.2.2(16/1)). However we first
4132 -- have to check for the case of a prefix that is a controlling operand
4133 -- of a prefixed dispatching call, as the dereference is legal in that
4134 -- case. Normally this condition is checked in Validate_Remote_Access_
4135 -- To_Class_Wide_Type, but we have to defer the checking for selected
4136 -- component prefixes because of the prefixed dispatching call case.
4137 -- Note that implicit dereferences are checked for this just above.
4139 elsif Nkind (Name) = N_Explicit_Dereference
4140 and then Is_Remote_Access_To_Class_Wide_Type (Etype (Prefix (Name)))
4141 and then Comes_From_Source (N)
4142 then
4143 if Try_Object_Operation (N) then
4144 return;
4145 else
4146 Error_Msg_N
4147 ("invalid dereference of a remote access-to-class-wide value",
4149 end if;
4150 end if;
4152 -- (Ada 2005): if the prefix is the limited view of a type, and
4153 -- the context already includes the full view, use the full view
4154 -- in what follows, either to retrieve a component of to find
4155 -- a primitive operation. If the prefix is an explicit dereference,
4156 -- set the type of the prefix to reflect this transformation.
4157 -- If the non-limited view is itself an incomplete type, get the
4158 -- full view if available.
4160 if Is_Incomplete_Type (Prefix_Type)
4161 and then From_Limited_With (Prefix_Type)
4162 and then Present (Non_Limited_View (Prefix_Type))
4163 then
4164 Prefix_Type := Get_Full_View (Non_Limited_View (Prefix_Type));
4166 if Nkind (N) = N_Explicit_Dereference then
4167 Set_Etype (Prefix (N), Prefix_Type);
4168 end if;
4170 elsif Ekind (Prefix_Type) = E_Class_Wide_Type
4171 and then From_Limited_With (Prefix_Type)
4172 and then Present (Non_Limited_View (Etype (Prefix_Type)))
4173 then
4174 Prefix_Type :=
4175 Class_Wide_Type (Non_Limited_View (Etype (Prefix_Type)));
4177 if Nkind (N) = N_Explicit_Dereference then
4178 Set_Etype (Prefix (N), Prefix_Type);
4179 end if;
4180 end if;
4182 if Ekind (Prefix_Type) = E_Private_Subtype then
4183 Prefix_Type := Base_Type (Prefix_Type);
4184 end if;
4186 Type_To_Use := Prefix_Type;
4188 -- For class-wide types, use the entity list of the root type. This
4189 -- indirection is specially important for private extensions because
4190 -- only the root type get switched (not the class-wide type).
4192 if Is_Class_Wide_Type (Prefix_Type) then
4193 Type_To_Use := Root_Type (Prefix_Type);
4194 end if;
4196 -- If the prefix is a single concurrent object, use its name in error
4197 -- messages, rather than that of its anonymous type.
4199 Is_Single_Concurrent_Object :=
4200 Is_Concurrent_Type (Prefix_Type)
4201 and then Is_Internal_Name (Chars (Prefix_Type))
4202 and then not Is_Derived_Type (Prefix_Type)
4203 and then Is_Entity_Name (Name);
4205 Comp := First_Entity (Type_To_Use);
4207 -- If the selector has an original discriminant, the node appears in
4208 -- an instance. Replace the discriminant with the corresponding one
4209 -- in the current discriminated type. For nested generics, this must
4210 -- be done transitively, so note the new original discriminant.
4212 if Nkind (Sel) = N_Identifier
4213 and then In_Instance
4214 and then Present (Original_Discriminant (Sel))
4215 then
4216 Comp := Find_Corresponding_Discriminant (Sel, Prefix_Type);
4218 -- Mark entity before rewriting, for completeness and because
4219 -- subsequent semantic checks might examine the original node.
4221 Set_Entity (Sel, Comp);
4222 Rewrite (Selector_Name (N), New_Occurrence_Of (Comp, Sloc (N)));
4223 Set_Original_Discriminant (Selector_Name (N), Comp);
4224 Set_Etype (N, Etype (Comp));
4225 Check_Implicit_Dereference (N, Etype (Comp));
4227 if Is_Access_Type (Etype (Name)) then
4228 Insert_Explicit_Dereference (Name);
4229 Error_Msg_NW (Warn_On_Dereference, "?d?implicit dereference", N);
4230 end if;
4232 elsif Is_Record_Type (Prefix_Type) then
4234 -- Find component with given name. In an instance, if the node is
4235 -- known as a prefixed call, do not examine components whose
4236 -- visibility may be accidental.
4238 while Present (Comp) and then not Is_Prefixed_Call (N) loop
4239 if Chars (Comp) = Chars (Sel)
4240 and then Is_Visible_Component (Comp, N)
4241 then
4242 Set_Entity_With_Checks (Sel, Comp);
4243 Set_Etype (Sel, Etype (Comp));
4245 if Ekind (Comp) = E_Discriminant then
4246 if Is_Unchecked_Union (Base_Type (Prefix_Type)) then
4247 Error_Msg_N
4248 ("cannot reference discriminant of unchecked union",
4249 Sel);
4250 end if;
4252 if Is_Generic_Type (Prefix_Type)
4253 or else
4254 Is_Generic_Type (Root_Type (Prefix_Type))
4255 then
4256 Set_Original_Discriminant (Sel, Comp);
4257 end if;
4258 end if;
4260 -- Resolve the prefix early otherwise it is not possible to
4261 -- build the actual subtype of the component: it may need
4262 -- to duplicate this prefix and duplication is only allowed
4263 -- on fully resolved expressions.
4265 Resolve (Name);
4267 -- Ada 2005 (AI-50217): Check wrong use of incomplete types or
4268 -- subtypes in a package specification.
4269 -- Example:
4271 -- limited with Pkg;
4272 -- package Pkg is
4273 -- type Acc_Inc is access Pkg.T;
4274 -- X : Acc_Inc;
4275 -- N : Natural := X.all.Comp; -- ERROR, limited view
4276 -- end Pkg; -- Comp is not visible
4278 if Nkind (Name) = N_Explicit_Dereference
4279 and then From_Limited_With (Etype (Prefix (Name)))
4280 and then not Is_Potentially_Use_Visible (Etype (Name))
4281 and then Nkind (Parent (Cunit_Entity (Current_Sem_Unit))) =
4282 N_Package_Specification
4283 then
4284 Error_Msg_NE
4285 ("premature usage of incomplete}", Prefix (Name),
4286 Etype (Prefix (Name)));
4287 end if;
4289 -- We never need an actual subtype for the case of a selection
4290 -- for a indexed component of a non-packed array, since in
4291 -- this case gigi generates all the checks and can find the
4292 -- necessary bounds information.
4294 -- We also do not need an actual subtype for the case of a
4295 -- first, last, length, or range attribute applied to a
4296 -- non-packed array, since gigi can again get the bounds in
4297 -- these cases (gigi cannot handle the packed case, since it
4298 -- has the bounds of the packed array type, not the original
4299 -- bounds of the type). However, if the prefix is itself a
4300 -- selected component, as in a.b.c (i), gigi may regard a.b.c
4301 -- as a dynamic-sized temporary, so we do generate an actual
4302 -- subtype for this case.
4304 Parent_N := Parent (N);
4306 if not Is_Packed (Etype (Comp))
4307 and then
4308 ((Nkind (Parent_N) = N_Indexed_Component
4309 and then Nkind (Name) /= N_Selected_Component)
4310 or else
4311 (Nkind (Parent_N) = N_Attribute_Reference
4312 and then
4313 Nam_In (Attribute_Name (Parent_N), Name_First,
4314 Name_Last,
4315 Name_Length,
4316 Name_Range)))
4317 then
4318 Set_Etype (N, Etype (Comp));
4320 -- If full analysis is not enabled, we do not generate an
4321 -- actual subtype, because in the absence of expansion
4322 -- reference to a formal of a protected type, for example,
4323 -- will not be properly transformed, and will lead to
4324 -- out-of-scope references in gigi.
4326 -- In all other cases, we currently build an actual subtype.
4327 -- It seems likely that many of these cases can be avoided,
4328 -- but right now, the front end makes direct references to the
4329 -- bounds (e.g. in generating a length check), and if we do
4330 -- not make an actual subtype, we end up getting a direct
4331 -- reference to a discriminant, which will not do.
4333 elsif Full_Analysis then
4334 Act_Decl :=
4335 Build_Actual_Subtype_Of_Component (Etype (Comp), N);
4336 Insert_Action (N, Act_Decl);
4338 if No (Act_Decl) then
4339 Set_Etype (N, Etype (Comp));
4341 else
4342 -- Component type depends on discriminants. Enter the
4343 -- main attributes of the subtype.
4345 declare
4346 Subt : constant Entity_Id :=
4347 Defining_Identifier (Act_Decl);
4349 begin
4350 Set_Etype (Subt, Base_Type (Etype (Comp)));
4351 Set_Ekind (Subt, Ekind (Etype (Comp)));
4352 Set_Etype (N, Subt);
4353 end;
4354 end if;
4356 -- If Full_Analysis not enabled, just set the Etype
4358 else
4359 Set_Etype (N, Etype (Comp));
4360 end if;
4362 Check_Implicit_Dereference (N, Etype (N));
4363 return;
4364 end if;
4366 -- If the prefix is a private extension, check only the visible
4367 -- components of the partial view. This must include the tag,
4368 -- which can appear in expanded code in a tag check.
4370 if Ekind (Type_To_Use) = E_Record_Type_With_Private
4371 and then Chars (Selector_Name (N)) /= Name_uTag
4372 then
4373 exit when Comp = Last_Entity (Type_To_Use);
4374 end if;
4376 Next_Entity (Comp);
4377 end loop;
4379 -- Ada 2005 (AI-252): The selected component can be interpreted as
4380 -- a prefixed view of a subprogram. Depending on the context, this is
4381 -- either a name that can appear in a renaming declaration, or part
4382 -- of an enclosing call given in prefix form.
4384 -- Ada 2005 (AI05-0030): In the case of dispatching requeue, the
4385 -- selected component should resolve to a name.
4387 if Ada_Version >= Ada_2005
4388 and then Is_Tagged_Type (Prefix_Type)
4389 and then not Is_Concurrent_Type (Prefix_Type)
4390 then
4391 if Nkind (Parent (N)) = N_Generic_Association
4392 or else Nkind (Parent (N)) = N_Requeue_Statement
4393 or else Nkind (Parent (N)) = N_Subprogram_Renaming_Declaration
4394 then
4395 if Find_Primitive_Operation (N) then
4396 return;
4397 end if;
4399 elsif Try_Object_Operation (N) then
4400 return;
4401 end if;
4403 -- If the transformation fails, it will be necessary to redo the
4404 -- analysis with all errors enabled, to indicate candidate
4405 -- interpretations and reasons for each failure ???
4407 end if;
4409 elsif Is_Private_Type (Prefix_Type) then
4411 -- Allow access only to discriminants of the type. If the type has
4412 -- no full view, gigi uses the parent type for the components, so we
4413 -- do the same here.
4415 if No (Full_View (Prefix_Type)) then
4416 Type_To_Use := Root_Type (Base_Type (Prefix_Type));
4417 Comp := First_Entity (Type_To_Use);
4418 end if;
4420 while Present (Comp) loop
4421 if Chars (Comp) = Chars (Sel) then
4422 if Ekind (Comp) = E_Discriminant then
4423 Set_Entity_With_Checks (Sel, Comp);
4424 Generate_Reference (Comp, Sel);
4426 Set_Etype (Sel, Etype (Comp));
4427 Set_Etype (N, Etype (Comp));
4428 Check_Implicit_Dereference (N, Etype (N));
4430 if Is_Generic_Type (Prefix_Type)
4431 or else Is_Generic_Type (Root_Type (Prefix_Type))
4432 then
4433 Set_Original_Discriminant (Sel, Comp);
4434 end if;
4436 -- Before declaring an error, check whether this is tagged
4437 -- private type and a call to a primitive operation.
4439 elsif Ada_Version >= Ada_2005
4440 and then Is_Tagged_Type (Prefix_Type)
4441 and then Try_Object_Operation (N)
4442 then
4443 return;
4445 else
4446 Error_Msg_Node_2 := First_Subtype (Prefix_Type);
4447 Error_Msg_NE ("invisible selector& for }", N, Sel);
4448 Set_Entity (Sel, Any_Id);
4449 Set_Etype (N, Any_Type);
4450 end if;
4452 return;
4453 end if;
4455 Next_Entity (Comp);
4456 end loop;
4458 elsif Is_Concurrent_Type (Prefix_Type) then
4460 -- Find visible operation with given name. For a protected type,
4461 -- the possible candidates are discriminants, entries or protected
4462 -- procedures. For a task type, the set can only include entries or
4463 -- discriminants if the task type is not an enclosing scope. If it
4464 -- is an enclosing scope (e.g. in an inner task) then all entities
4465 -- are visible, but the prefix must denote the enclosing scope, i.e.
4466 -- can only be a direct name or an expanded name.
4468 Set_Etype (Sel, Any_Type);
4469 In_Scope := In_Open_Scopes (Prefix_Type);
4471 while Present (Comp) loop
4472 if Chars (Comp) = Chars (Sel) then
4473 if Is_Overloadable (Comp) then
4474 Add_One_Interp (Sel, Comp, Etype (Comp));
4476 -- If the prefix is tagged, the correct interpretation may
4477 -- lie in the primitive or class-wide operations of the
4478 -- type. Perform a simple conformance check to determine
4479 -- whether Try_Object_Operation should be invoked even if
4480 -- a visible entity is found.
4482 if Is_Tagged_Type (Prefix_Type)
4483 and then
4484 Nkind_In (Parent (N), N_Procedure_Call_Statement,
4485 N_Function_Call,
4486 N_Indexed_Component)
4487 and then Has_Mode_Conformant_Spec (Comp)
4488 then
4489 Has_Candidate := True;
4490 end if;
4492 -- Note: a selected component may not denote a component of a
4493 -- protected type (4.1.3(7)).
4495 elsif Ekind_In (Comp, E_Discriminant, E_Entry_Family)
4496 or else (In_Scope
4497 and then not Is_Protected_Type (Prefix_Type)
4498 and then Is_Entity_Name (Name))
4499 then
4500 Set_Entity_With_Checks (Sel, Comp);
4501 Generate_Reference (Comp, Sel);
4503 -- The selector is not overloadable, so we have a candidate
4504 -- interpretation.
4506 Has_Candidate := True;
4508 else
4509 goto Next_Comp;
4510 end if;
4512 Set_Etype (Sel, Etype (Comp));
4513 Set_Etype (N, Etype (Comp));
4515 if Ekind (Comp) = E_Discriminant then
4516 Set_Original_Discriminant (Sel, Comp);
4517 end if;
4519 -- For access type case, introduce explicit dereference for
4520 -- more uniform treatment of entry calls.
4522 if Is_Access_Type (Etype (Name)) then
4523 Insert_Explicit_Dereference (Name);
4524 Error_Msg_NW
4525 (Warn_On_Dereference, "?d?implicit dereference", N);
4526 end if;
4527 end if;
4529 <<Next_Comp>>
4530 Next_Entity (Comp);
4531 exit when not In_Scope
4532 and then
4533 Comp = First_Private_Entity (Base_Type (Prefix_Type));
4534 end loop;
4536 -- If there is no visible entity with the given name or none of the
4537 -- visible entities are plausible interpretations, check whether
4538 -- there is some other primitive operation with that name.
4540 if Ada_Version >= Ada_2005
4541 and then Is_Tagged_Type (Prefix_Type)
4542 then
4543 if (Etype (N) = Any_Type
4544 or else not Has_Candidate)
4545 and then Try_Object_Operation (N)
4546 then
4547 return;
4549 -- If the context is not syntactically a procedure call, it
4550 -- may be a call to a primitive function declared outside of
4551 -- the synchronized type.
4553 -- If the context is a procedure call, there might still be
4554 -- an overloading between an entry and a primitive procedure
4555 -- declared outside of the synchronized type, called in prefix
4556 -- notation. This is harder to disambiguate because in one case
4557 -- the controlling formal is implicit ???
4559 elsif Nkind (Parent (N)) /= N_Procedure_Call_Statement
4560 and then Nkind (Parent (N)) /= N_Indexed_Component
4561 and then Try_Object_Operation (N)
4562 then
4563 return;
4564 end if;
4566 -- Ada 2012 (AI05-0090-1): If we found a candidate of a call to an
4567 -- entry or procedure of a tagged concurrent type we must check
4568 -- if there are class-wide subprograms covering the primitive. If
4569 -- true then Try_Object_Operation reports the error.
4571 if Has_Candidate
4572 and then Is_Concurrent_Type (Prefix_Type)
4573 and then Nkind (Parent (N)) = N_Procedure_Call_Statement
4575 -- Duplicate the call. This is required to avoid problems with
4576 -- the tree transformations performed by Try_Object_Operation.
4577 -- Set properly the parent of the copied call, because it is
4578 -- about to be reanalyzed.
4580 then
4581 declare
4582 Par : constant Node_Id := New_Copy_Tree (Parent (N));
4584 begin
4585 Set_Parent (Par, Parent (Parent (N)));
4587 if Try_Object_Operation
4588 (Sinfo.Name (Par), CW_Test_Only => True)
4589 then
4590 return;
4591 end if;
4592 end;
4593 end if;
4594 end if;
4596 if Etype (N) = Any_Type and then Is_Protected_Type (Prefix_Type) then
4598 -- Case of a prefix of a protected type: selector might denote
4599 -- an invisible private component.
4601 Comp := First_Private_Entity (Base_Type (Prefix_Type));
4602 while Present (Comp) and then Chars (Comp) /= Chars (Sel) loop
4603 Next_Entity (Comp);
4604 end loop;
4606 if Present (Comp) then
4607 if Is_Single_Concurrent_Object then
4608 Error_Msg_Node_2 := Entity (Name);
4609 Error_Msg_NE ("invisible selector& for &", N, Sel);
4611 else
4612 Error_Msg_Node_2 := First_Subtype (Prefix_Type);
4613 Error_Msg_NE ("invisible selector& for }", N, Sel);
4614 end if;
4615 return;
4616 end if;
4617 end if;
4619 Set_Is_Overloaded (N, Is_Overloaded (Sel));
4621 else
4622 -- Invalid prefix
4624 Error_Msg_NE ("invalid prefix in selected component&", N, Sel);
4625 end if;
4627 -- If N still has no type, the component is not defined in the prefix
4629 if Etype (N) = Any_Type then
4631 if Is_Single_Concurrent_Object then
4632 Error_Msg_Node_2 := Entity (Name);
4633 Error_Msg_NE ("no selector& for&", N, Sel);
4635 Check_Misspelled_Selector (Type_To_Use, Sel);
4637 -- If this is a derived formal type, the parent may have different
4638 -- visibility at this point. Try for an inherited component before
4639 -- reporting an error.
4641 elsif Is_Generic_Type (Prefix_Type)
4642 and then Ekind (Prefix_Type) = E_Record_Type_With_Private
4643 and then Prefix_Type /= Etype (Prefix_Type)
4644 and then Is_Record_Type (Etype (Prefix_Type))
4645 then
4646 Set_Etype (Prefix (N), Etype (Prefix_Type));
4647 Analyze_Selected_Component (N);
4648 return;
4650 -- Similarly, if this is the actual for a formal derived type, or
4651 -- a derived type thereof, the component inherited from the generic
4652 -- parent may not be visible in the actual, but the selected
4653 -- component is legal. Climb up the derivation chain of the generic
4654 -- parent type until we find the proper ancestor type.
4656 elsif In_Instance and then Is_Tagged_Type (Prefix_Type) then
4657 declare
4658 Par : Entity_Id := Prefix_Type;
4659 begin
4660 -- Climb up derivation chain to generic actual subtype
4662 while not Is_Generic_Actual_Type (Par) loop
4663 if Ekind (Par) = E_Record_Type then
4664 Par := Parent_Subtype (Par);
4665 exit when No (Par);
4666 else
4667 exit when Par = Etype (Par);
4668 Par := Etype (Par);
4669 end if;
4670 end loop;
4672 if Present (Par) and then Is_Generic_Actual_Type (Par) then
4673 -- Now look for component in ancestor types
4675 Par := Generic_Parent_Type (Declaration_Node (Par));
4676 loop
4677 Find_Component_In_Instance (Par);
4678 exit when Present (Entity (Sel))
4679 or else Par = Etype (Par);
4680 Par := Etype (Par);
4681 end loop;
4682 end if;
4683 end;
4685 -- The search above must have eventually succeeded, since the
4686 -- selected component was legal in the generic.
4688 if No (Entity (Sel)) then
4689 raise Program_Error;
4690 end if;
4691 return;
4693 -- Component not found, specialize error message when appropriate
4695 else
4696 if Ekind (Prefix_Type) = E_Record_Subtype then
4698 -- Check whether this is a component of the base type which
4699 -- is absent from a statically constrained subtype. This will
4700 -- raise constraint error at run time, but is not a compile-
4701 -- time error. When the selector is illegal for base type as
4702 -- well fall through and generate a compilation error anyway.
4704 Comp := First_Component (Base_Type (Prefix_Type));
4705 while Present (Comp) loop
4706 if Chars (Comp) = Chars (Sel)
4707 and then Is_Visible_Component (Comp)
4708 then
4709 Set_Entity_With_Checks (Sel, Comp);
4710 Generate_Reference (Comp, Sel);
4711 Set_Etype (Sel, Etype (Comp));
4712 Set_Etype (N, Etype (Comp));
4714 -- Emit appropriate message. The node will be replaced
4715 -- by an appropriate raise statement.
4717 -- Note that in SPARK mode, as with all calls to apply a
4718 -- compile time constraint error, this will be made into
4719 -- an error to simplify the processing of the formal
4720 -- verification backend.
4722 Apply_Compile_Time_Constraint_Error
4723 (N, "component not present in }??",
4724 CE_Discriminant_Check_Failed,
4725 Ent => Prefix_Type, Rep => False);
4727 Set_Raises_Constraint_Error (N);
4728 return;
4729 end if;
4731 Next_Component (Comp);
4732 end loop;
4734 end if;
4736 Error_Msg_Node_2 := First_Subtype (Prefix_Type);
4737 Error_Msg_NE ("no selector& for}", N, Sel);
4739 -- Add information in the case of an incomplete prefix
4741 if Is_Incomplete_Type (Type_To_Use) then
4742 declare
4743 Inc : constant Entity_Id := First_Subtype (Type_To_Use);
4745 begin
4746 if From_Limited_With (Scope (Type_To_Use)) then
4747 Error_Msg_NE
4748 ("\limited view of& has no components", N, Inc);
4750 else
4751 Error_Msg_NE
4752 ("\premature usage of incomplete type&", N, Inc);
4754 if Nkind (Parent (Inc)) =
4755 N_Incomplete_Type_Declaration
4756 then
4757 -- Record location of premature use in entity so that
4758 -- a continuation message is generated when the
4759 -- completion is seen.
4761 Set_Premature_Use (Parent (Inc), N);
4762 end if;
4763 end if;
4764 end;
4765 end if;
4767 Check_Misspelled_Selector (Type_To_Use, Sel);
4768 end if;
4770 Set_Entity (Sel, Any_Id);
4771 Set_Etype (Sel, Any_Type);
4772 end if;
4773 end Analyze_Selected_Component;
4775 ---------------------------
4776 -- Analyze_Short_Circuit --
4777 ---------------------------
4779 procedure Analyze_Short_Circuit (N : Node_Id) is
4780 L : constant Node_Id := Left_Opnd (N);
4781 R : constant Node_Id := Right_Opnd (N);
4782 Ind : Interp_Index;
4783 It : Interp;
4785 begin
4786 Analyze_Expression (L);
4787 Analyze_Expression (R);
4788 Set_Etype (N, Any_Type);
4790 if not Is_Overloaded (L) then
4791 if Root_Type (Etype (L)) = Standard_Boolean
4792 and then Has_Compatible_Type (R, Etype (L))
4793 then
4794 Add_One_Interp (N, Etype (L), Etype (L));
4795 end if;
4797 else
4798 Get_First_Interp (L, Ind, It);
4799 while Present (It.Typ) loop
4800 if Root_Type (It.Typ) = Standard_Boolean
4801 and then Has_Compatible_Type (R, It.Typ)
4802 then
4803 Add_One_Interp (N, It.Typ, It.Typ);
4804 end if;
4806 Get_Next_Interp (Ind, It);
4807 end loop;
4808 end if;
4810 -- Here we have failed to find an interpretation. Clearly we know that
4811 -- it is not the case that both operands can have an interpretation of
4812 -- Boolean, but this is by far the most likely intended interpretation.
4813 -- So we simply resolve both operands as Booleans, and at least one of
4814 -- these resolutions will generate an error message, and we do not need
4815 -- to give another error message on the short circuit operation itself.
4817 if Etype (N) = Any_Type then
4818 Resolve (L, Standard_Boolean);
4819 Resolve (R, Standard_Boolean);
4820 Set_Etype (N, Standard_Boolean);
4821 end if;
4822 end Analyze_Short_Circuit;
4824 -------------------
4825 -- Analyze_Slice --
4826 -------------------
4828 procedure Analyze_Slice (N : Node_Id) is
4829 D : constant Node_Id := Discrete_Range (N);
4830 P : constant Node_Id := Prefix (N);
4831 Array_Type : Entity_Id;
4832 Index_Type : Entity_Id;
4834 procedure Analyze_Overloaded_Slice;
4835 -- If the prefix is overloaded, select those interpretations that
4836 -- yield a one-dimensional array type.
4838 ------------------------------
4839 -- Analyze_Overloaded_Slice --
4840 ------------------------------
4842 procedure Analyze_Overloaded_Slice is
4843 I : Interp_Index;
4844 It : Interp;
4845 Typ : Entity_Id;
4847 begin
4848 Set_Etype (N, Any_Type);
4850 Get_First_Interp (P, I, It);
4851 while Present (It.Nam) loop
4852 Typ := It.Typ;
4854 if Is_Access_Type (Typ) then
4855 Typ := Designated_Type (Typ);
4856 Error_Msg_NW
4857 (Warn_On_Dereference, "?d?implicit dereference", N);
4858 end if;
4860 if Is_Array_Type (Typ)
4861 and then Number_Dimensions (Typ) = 1
4862 and then Has_Compatible_Type (D, Etype (First_Index (Typ)))
4863 then
4864 Add_One_Interp (N, Typ, Typ);
4865 end if;
4867 Get_Next_Interp (I, It);
4868 end loop;
4870 if Etype (N) = Any_Type then
4871 Error_Msg_N ("expect array type in prefix of slice", N);
4872 end if;
4873 end Analyze_Overloaded_Slice;
4875 -- Start of processing for Analyze_Slice
4877 begin
4878 if Comes_From_Source (N) then
4879 Check_SPARK_Restriction ("slice is not allowed", N);
4880 end if;
4882 Analyze (P);
4883 Analyze (D);
4885 if Is_Overloaded (P) then
4886 Analyze_Overloaded_Slice;
4888 else
4889 Array_Type := Etype (P);
4890 Set_Etype (N, Any_Type);
4892 if Is_Access_Type (Array_Type) then
4893 Array_Type := Designated_Type (Array_Type);
4894 Error_Msg_NW (Warn_On_Dereference, "?d?implicit dereference", N);
4895 end if;
4897 if not Is_Array_Type (Array_Type) then
4898 Wrong_Type (P, Any_Array);
4900 elsif Number_Dimensions (Array_Type) > 1 then
4901 Error_Msg_N
4902 ("type is not one-dimensional array in slice prefix", N);
4904 else
4905 if Ekind (Array_Type) = E_String_Literal_Subtype then
4906 Index_Type := Etype (String_Literal_Low_Bound (Array_Type));
4907 else
4908 Index_Type := Etype (First_Index (Array_Type));
4909 end if;
4911 if not Has_Compatible_Type (D, Index_Type) then
4912 Wrong_Type (D, Index_Type);
4913 else
4914 Set_Etype (N, Array_Type);
4915 end if;
4916 end if;
4917 end if;
4918 end Analyze_Slice;
4920 -----------------------------
4921 -- Analyze_Type_Conversion --
4922 -----------------------------
4924 procedure Analyze_Type_Conversion (N : Node_Id) is
4925 Expr : constant Node_Id := Expression (N);
4926 T : Entity_Id;
4928 begin
4929 -- If Conversion_OK is set, then the Etype is already set, and the
4930 -- only processing required is to analyze the expression. This is
4931 -- used to construct certain "illegal" conversions which are not
4932 -- allowed by Ada semantics, but can be handled OK by Gigi, see
4933 -- Sinfo for further details.
4935 if Conversion_OK (N) then
4936 Analyze (Expr);
4937 return;
4938 end if;
4940 -- Otherwise full type analysis is required, as well as some semantic
4941 -- checks to make sure the argument of the conversion is appropriate.
4943 Find_Type (Subtype_Mark (N));
4944 T := Entity (Subtype_Mark (N));
4945 Set_Etype (N, T);
4946 Check_Fully_Declared (T, N);
4947 Analyze_Expression (Expr);
4948 Validate_Remote_Type_Type_Conversion (N);
4950 -- Only remaining step is validity checks on the argument. These
4951 -- are skipped if the conversion does not come from the source.
4953 if not Comes_From_Source (N) then
4954 return;
4956 -- If there was an error in a generic unit, no need to replicate the
4957 -- error message. Conversely, constant-folding in the generic may
4958 -- transform the argument of a conversion into a string literal, which
4959 -- is legal. Therefore the following tests are not performed in an
4960 -- instance.
4962 elsif In_Instance then
4963 return;
4965 elsif Nkind (Expr) = N_Null then
4966 Error_Msg_N ("argument of conversion cannot be null", N);
4967 Error_Msg_N ("\use qualified expression instead", N);
4968 Set_Etype (N, Any_Type);
4970 elsif Nkind (Expr) = N_Aggregate then
4971 Error_Msg_N ("argument of conversion cannot be aggregate", N);
4972 Error_Msg_N ("\use qualified expression instead", N);
4974 elsif Nkind (Expr) = N_Allocator then
4975 Error_Msg_N ("argument of conversion cannot be an allocator", N);
4976 Error_Msg_N ("\use qualified expression instead", N);
4978 elsif Nkind (Expr) = N_String_Literal then
4979 Error_Msg_N ("argument of conversion cannot be string literal", N);
4980 Error_Msg_N ("\use qualified expression instead", N);
4982 elsif Nkind (Expr) = N_Character_Literal then
4983 if Ada_Version = Ada_83 then
4984 Resolve (Expr, T);
4985 else
4986 Error_Msg_N ("argument of conversion cannot be character literal",
4988 Error_Msg_N ("\use qualified expression instead", N);
4989 end if;
4991 elsif Nkind (Expr) = N_Attribute_Reference
4992 and then
4993 Nam_In (Attribute_Name (Expr), Name_Access,
4994 Name_Unchecked_Access,
4995 Name_Unrestricted_Access)
4996 then
4997 Error_Msg_N ("argument of conversion cannot be access", N);
4998 Error_Msg_N ("\use qualified expression instead", N);
4999 end if;
5000 end Analyze_Type_Conversion;
5002 ----------------------
5003 -- Analyze_Unary_Op --
5004 ----------------------
5006 procedure Analyze_Unary_Op (N : Node_Id) is
5007 R : constant Node_Id := Right_Opnd (N);
5008 Op_Id : Entity_Id := Entity (N);
5010 begin
5011 Set_Etype (N, Any_Type);
5012 Candidate_Type := Empty;
5014 Analyze_Expression (R);
5016 if Present (Op_Id) then
5017 if Ekind (Op_Id) = E_Operator then
5018 Find_Unary_Types (R, Op_Id, N);
5019 else
5020 Add_One_Interp (N, Op_Id, Etype (Op_Id));
5021 end if;
5023 else
5024 Op_Id := Get_Name_Entity_Id (Chars (N));
5025 while Present (Op_Id) loop
5026 if Ekind (Op_Id) = E_Operator then
5027 if No (Next_Entity (First_Entity (Op_Id))) then
5028 Find_Unary_Types (R, Op_Id, N);
5029 end if;
5031 elsif Is_Overloadable (Op_Id) then
5032 Analyze_User_Defined_Unary_Op (N, Op_Id);
5033 end if;
5035 Op_Id := Homonym (Op_Id);
5036 end loop;
5037 end if;
5039 Operator_Check (N);
5040 end Analyze_Unary_Op;
5042 ----------------------------------
5043 -- Analyze_Unchecked_Expression --
5044 ----------------------------------
5046 procedure Analyze_Unchecked_Expression (N : Node_Id) is
5047 begin
5048 Analyze (Expression (N), Suppress => All_Checks);
5049 Set_Etype (N, Etype (Expression (N)));
5050 Save_Interps (Expression (N), N);
5051 end Analyze_Unchecked_Expression;
5053 ---------------------------------------
5054 -- Analyze_Unchecked_Type_Conversion --
5055 ---------------------------------------
5057 procedure Analyze_Unchecked_Type_Conversion (N : Node_Id) is
5058 begin
5059 Find_Type (Subtype_Mark (N));
5060 Analyze_Expression (Expression (N));
5061 Set_Etype (N, Entity (Subtype_Mark (N)));
5062 end Analyze_Unchecked_Type_Conversion;
5064 ------------------------------------
5065 -- Analyze_User_Defined_Binary_Op --
5066 ------------------------------------
5068 procedure Analyze_User_Defined_Binary_Op
5069 (N : Node_Id;
5070 Op_Id : Entity_Id)
5072 begin
5073 -- Only do analysis if the operator Comes_From_Source, since otherwise
5074 -- the operator was generated by the expander, and all such operators
5075 -- always refer to the operators in package Standard.
5077 if Comes_From_Source (N) then
5078 declare
5079 F1 : constant Entity_Id := First_Formal (Op_Id);
5080 F2 : constant Entity_Id := Next_Formal (F1);
5082 begin
5083 -- Verify that Op_Id is a visible binary function. Note that since
5084 -- we know Op_Id is overloaded, potentially use visible means use
5085 -- visible for sure (RM 9.4(11)).
5087 if Ekind (Op_Id) = E_Function
5088 and then Present (F2)
5089 and then (Is_Immediately_Visible (Op_Id)
5090 or else Is_Potentially_Use_Visible (Op_Id))
5091 and then Has_Compatible_Type (Left_Opnd (N), Etype (F1))
5092 and then Has_Compatible_Type (Right_Opnd (N), Etype (F2))
5093 then
5094 Add_One_Interp (N, Op_Id, Etype (Op_Id));
5096 -- If the left operand is overloaded, indicate that the current
5097 -- type is a viable candidate. This is redundant in most cases,
5098 -- but for equality and comparison operators where the context
5099 -- does not impose a type on the operands, setting the proper
5100 -- type is necessary to avoid subsequent ambiguities during
5101 -- resolution, when both user-defined and predefined operators
5102 -- may be candidates.
5104 if Is_Overloaded (Left_Opnd (N)) then
5105 Set_Etype (Left_Opnd (N), Etype (F1));
5106 end if;
5108 if Debug_Flag_E then
5109 Write_Str ("user defined operator ");
5110 Write_Name (Chars (Op_Id));
5111 Write_Str (" on node ");
5112 Write_Int (Int (N));
5113 Write_Eol;
5114 end if;
5115 end if;
5116 end;
5117 end if;
5118 end Analyze_User_Defined_Binary_Op;
5120 -----------------------------------
5121 -- Analyze_User_Defined_Unary_Op --
5122 -----------------------------------
5124 procedure Analyze_User_Defined_Unary_Op
5125 (N : Node_Id;
5126 Op_Id : Entity_Id)
5128 begin
5129 -- Only do analysis if the operator Comes_From_Source, since otherwise
5130 -- the operator was generated by the expander, and all such operators
5131 -- always refer to the operators in package Standard.
5133 if Comes_From_Source (N) then
5134 declare
5135 F : constant Entity_Id := First_Formal (Op_Id);
5137 begin
5138 -- Verify that Op_Id is a visible unary function. Note that since
5139 -- we know Op_Id is overloaded, potentially use visible means use
5140 -- visible for sure (RM 9.4(11)).
5142 if Ekind (Op_Id) = E_Function
5143 and then No (Next_Formal (F))
5144 and then (Is_Immediately_Visible (Op_Id)
5145 or else Is_Potentially_Use_Visible (Op_Id))
5146 and then Has_Compatible_Type (Right_Opnd (N), Etype (F))
5147 then
5148 Add_One_Interp (N, Op_Id, Etype (Op_Id));
5149 end if;
5150 end;
5151 end if;
5152 end Analyze_User_Defined_Unary_Op;
5154 ---------------------------
5155 -- Check_Arithmetic_Pair --
5156 ---------------------------
5158 procedure Check_Arithmetic_Pair
5159 (T1, T2 : Entity_Id;
5160 Op_Id : Entity_Id;
5161 N : Node_Id)
5163 Op_Name : constant Name_Id := Chars (Op_Id);
5165 function Has_Fixed_Op (Typ : Entity_Id; Op : Entity_Id) return Boolean;
5166 -- Check whether the fixed-point type Typ has a user-defined operator
5167 -- (multiplication or division) that should hide the corresponding
5168 -- predefined operator. Used to implement Ada 2005 AI-264, to make
5169 -- such operators more visible and therefore useful.
5171 -- If the name of the operation is an expanded name with prefix
5172 -- Standard, the predefined universal fixed operator is available,
5173 -- as specified by AI-420 (RM 4.5.5 (19.1/2)).
5175 function Specific_Type (T1, T2 : Entity_Id) return Entity_Id;
5176 -- Get specific type (i.e. non-universal type if there is one)
5178 ------------------
5179 -- Has_Fixed_Op --
5180 ------------------
5182 function Has_Fixed_Op (Typ : Entity_Id; Op : Entity_Id) return Boolean is
5183 Bas : constant Entity_Id := Base_Type (Typ);
5184 Ent : Entity_Id;
5185 F1 : Entity_Id;
5186 F2 : Entity_Id;
5188 begin
5189 -- If the universal_fixed operation is given explicitly the rule
5190 -- concerning primitive operations of the type do not apply.
5192 if Nkind (N) = N_Function_Call
5193 and then Nkind (Name (N)) = N_Expanded_Name
5194 and then Entity (Prefix (Name (N))) = Standard_Standard
5195 then
5196 return False;
5197 end if;
5199 -- The operation is treated as primitive if it is declared in the
5200 -- same scope as the type, and therefore on the same entity chain.
5202 Ent := Next_Entity (Typ);
5203 while Present (Ent) loop
5204 if Chars (Ent) = Chars (Op) then
5205 F1 := First_Formal (Ent);
5206 F2 := Next_Formal (F1);
5208 -- The operation counts as primitive if either operand or
5209 -- result are of the given base type, and both operands are
5210 -- fixed point types.
5212 if (Base_Type (Etype (F1)) = Bas
5213 and then Is_Fixed_Point_Type (Etype (F2)))
5215 or else
5216 (Base_Type (Etype (F2)) = Bas
5217 and then Is_Fixed_Point_Type (Etype (F1)))
5219 or else
5220 (Base_Type (Etype (Ent)) = Bas
5221 and then Is_Fixed_Point_Type (Etype (F1))
5222 and then Is_Fixed_Point_Type (Etype (F2)))
5223 then
5224 return True;
5225 end if;
5226 end if;
5228 Next_Entity (Ent);
5229 end loop;
5231 return False;
5232 end Has_Fixed_Op;
5234 -------------------
5235 -- Specific_Type --
5236 -------------------
5238 function Specific_Type (T1, T2 : Entity_Id) return Entity_Id is
5239 begin
5240 if T1 = Universal_Integer or else T1 = Universal_Real then
5241 return Base_Type (T2);
5242 else
5243 return Base_Type (T1);
5244 end if;
5245 end Specific_Type;
5247 -- Start of processing for Check_Arithmetic_Pair
5249 begin
5250 if Nam_In (Op_Name, Name_Op_Add, Name_Op_Subtract) then
5251 if Is_Numeric_Type (T1)
5252 and then Is_Numeric_Type (T2)
5253 and then (Covers (T1 => T1, T2 => T2)
5254 or else
5255 Covers (T1 => T2, T2 => T1))
5256 then
5257 Add_One_Interp (N, Op_Id, Specific_Type (T1, T2));
5258 end if;
5260 elsif Nam_In (Op_Name, Name_Op_Multiply, Name_Op_Divide) then
5261 if Is_Fixed_Point_Type (T1)
5262 and then (Is_Fixed_Point_Type (T2) or else T2 = Universal_Real)
5263 then
5264 -- If Treat_Fixed_As_Integer is set then the Etype is already set
5265 -- and no further processing is required (this is the case of an
5266 -- operator constructed by Exp_Fixd for a fixed point operation)
5267 -- Otherwise add one interpretation with universal fixed result
5268 -- If the operator is given in functional notation, it comes
5269 -- from source and Fixed_As_Integer cannot apply.
5271 if (Nkind (N) not in N_Op
5272 or else not Treat_Fixed_As_Integer (N))
5273 and then
5274 (not Has_Fixed_Op (T1, Op_Id)
5275 or else Nkind (Parent (N)) = N_Type_Conversion)
5276 then
5277 Add_One_Interp (N, Op_Id, Universal_Fixed);
5278 end if;
5280 elsif Is_Fixed_Point_Type (T2)
5281 and then (Nkind (N) not in N_Op
5282 or else not Treat_Fixed_As_Integer (N))
5283 and then T1 = Universal_Real
5284 and then
5285 (not Has_Fixed_Op (T1, Op_Id)
5286 or else Nkind (Parent (N)) = N_Type_Conversion)
5287 then
5288 Add_One_Interp (N, Op_Id, Universal_Fixed);
5290 elsif Is_Numeric_Type (T1)
5291 and then Is_Numeric_Type (T2)
5292 and then (Covers (T1 => T1, T2 => T2)
5293 or else
5294 Covers (T1 => T2, T2 => T1))
5295 then
5296 Add_One_Interp (N, Op_Id, Specific_Type (T1, T2));
5298 elsif Is_Fixed_Point_Type (T1)
5299 and then (Base_Type (T2) = Base_Type (Standard_Integer)
5300 or else T2 = Universal_Integer)
5301 then
5302 Add_One_Interp (N, Op_Id, T1);
5304 elsif T2 = Universal_Real
5305 and then Base_Type (T1) = Base_Type (Standard_Integer)
5306 and then Op_Name = Name_Op_Multiply
5307 then
5308 Add_One_Interp (N, Op_Id, Any_Fixed);
5310 elsif T1 = Universal_Real
5311 and then Base_Type (T2) = Base_Type (Standard_Integer)
5312 then
5313 Add_One_Interp (N, Op_Id, Any_Fixed);
5315 elsif Is_Fixed_Point_Type (T2)
5316 and then (Base_Type (T1) = Base_Type (Standard_Integer)
5317 or else T1 = Universal_Integer)
5318 and then Op_Name = Name_Op_Multiply
5319 then
5320 Add_One_Interp (N, Op_Id, T2);
5322 elsif T1 = Universal_Real and then T2 = Universal_Integer then
5323 Add_One_Interp (N, Op_Id, T1);
5325 elsif T2 = Universal_Real
5326 and then T1 = Universal_Integer
5327 and then Op_Name = Name_Op_Multiply
5328 then
5329 Add_One_Interp (N, Op_Id, T2);
5330 end if;
5332 elsif Op_Name = Name_Op_Mod or else Op_Name = Name_Op_Rem then
5334 -- Note: The fixed-point operands case with Treat_Fixed_As_Integer
5335 -- set does not require any special processing, since the Etype is
5336 -- already set (case of operation constructed by Exp_Fixed).
5338 if Is_Integer_Type (T1)
5339 and then (Covers (T1 => T1, T2 => T2)
5340 or else
5341 Covers (T1 => T2, T2 => T1))
5342 then
5343 Add_One_Interp (N, Op_Id, Specific_Type (T1, T2));
5344 end if;
5346 elsif Op_Name = Name_Op_Expon then
5347 if Is_Numeric_Type (T1)
5348 and then not Is_Fixed_Point_Type (T1)
5349 and then (Base_Type (T2) = Base_Type (Standard_Integer)
5350 or else T2 = Universal_Integer)
5351 then
5352 Add_One_Interp (N, Op_Id, Base_Type (T1));
5353 end if;
5355 else pragma Assert (Nkind (N) in N_Op_Shift);
5357 -- If not one of the predefined operators, the node may be one
5358 -- of the intrinsic functions. Its kind is always specific, and
5359 -- we can use it directly, rather than the name of the operation.
5361 if Is_Integer_Type (T1)
5362 and then (Base_Type (T2) = Base_Type (Standard_Integer)
5363 or else T2 = Universal_Integer)
5364 then
5365 Add_One_Interp (N, Op_Id, Base_Type (T1));
5366 end if;
5367 end if;
5368 end Check_Arithmetic_Pair;
5370 -------------------------------
5371 -- Check_Misspelled_Selector --
5372 -------------------------------
5374 procedure Check_Misspelled_Selector
5375 (Prefix : Entity_Id;
5376 Sel : Node_Id)
5378 Max_Suggestions : constant := 2;
5379 Nr_Of_Suggestions : Natural := 0;
5381 Suggestion_1 : Entity_Id := Empty;
5382 Suggestion_2 : Entity_Id := Empty;
5384 Comp : Entity_Id;
5386 begin
5387 -- All the components of the prefix of selector Sel are matched against
5388 -- Sel and a count is maintained of possible misspellings. When at
5389 -- the end of the analysis there are one or two (not more) possible
5390 -- misspellings, these misspellings will be suggested as possible
5391 -- correction.
5393 if not (Is_Private_Type (Prefix) or else Is_Record_Type (Prefix)) then
5395 -- Concurrent types should be handled as well ???
5397 return;
5398 end if;
5400 Comp := First_Entity (Prefix);
5401 while Nr_Of_Suggestions <= Max_Suggestions and then Present (Comp) loop
5402 if Is_Visible_Component (Comp) then
5403 if Is_Bad_Spelling_Of (Chars (Comp), Chars (Sel)) then
5404 Nr_Of_Suggestions := Nr_Of_Suggestions + 1;
5406 case Nr_Of_Suggestions is
5407 when 1 => Suggestion_1 := Comp;
5408 when 2 => Suggestion_2 := Comp;
5409 when others => exit;
5410 end case;
5411 end if;
5412 end if;
5414 Comp := Next_Entity (Comp);
5415 end loop;
5417 -- Report at most two suggestions
5419 if Nr_Of_Suggestions = 1 then
5420 Error_Msg_NE -- CODEFIX
5421 ("\possible misspelling of&", Sel, Suggestion_1);
5423 elsif Nr_Of_Suggestions = 2 then
5424 Error_Msg_Node_2 := Suggestion_2;
5425 Error_Msg_NE -- CODEFIX
5426 ("\possible misspelling of& or&", Sel, Suggestion_1);
5427 end if;
5428 end Check_Misspelled_Selector;
5430 ----------------------
5431 -- Defined_In_Scope --
5432 ----------------------
5434 function Defined_In_Scope (T : Entity_Id; S : Entity_Id) return Boolean
5436 S1 : constant Entity_Id := Scope (Base_Type (T));
5437 begin
5438 return S1 = S
5439 or else (S1 = System_Aux_Id and then S = Scope (S1));
5440 end Defined_In_Scope;
5442 -------------------
5443 -- Diagnose_Call --
5444 -------------------
5446 procedure Diagnose_Call (N : Node_Id; Nam : Node_Id) is
5447 Actual : Node_Id;
5448 X : Interp_Index;
5449 It : Interp;
5450 Err_Mode : Boolean;
5451 New_Nam : Node_Id;
5452 Void_Interp_Seen : Boolean := False;
5454 Success : Boolean;
5455 pragma Warnings (Off, Boolean);
5457 begin
5458 if Ada_Version >= Ada_2005 then
5459 Actual := First_Actual (N);
5460 while Present (Actual) loop
5462 -- Ada 2005 (AI-50217): Post an error in case of premature
5463 -- usage of an entity from the limited view.
5465 if not Analyzed (Etype (Actual))
5466 and then From_Limited_With (Etype (Actual))
5467 then
5468 Error_Msg_Qual_Level := 1;
5469 Error_Msg_NE
5470 ("missing with_clause for scope of imported type&",
5471 Actual, Etype (Actual));
5472 Error_Msg_Qual_Level := 0;
5473 end if;
5475 Next_Actual (Actual);
5476 end loop;
5477 end if;
5479 -- Analyze each candidate call again, with full error reporting
5480 -- for each.
5482 Error_Msg_N
5483 ("no candidate interpretations match the actuals:!", Nam);
5484 Err_Mode := All_Errors_Mode;
5485 All_Errors_Mode := True;
5487 -- If this is a call to an operation of a concurrent type,
5488 -- the failed interpretations have been removed from the
5489 -- name. Recover them to provide full diagnostics.
5491 if Nkind (Parent (Nam)) = N_Selected_Component then
5492 Set_Entity (Nam, Empty);
5493 New_Nam := New_Copy_Tree (Parent (Nam));
5494 Set_Is_Overloaded (New_Nam, False);
5495 Set_Is_Overloaded (Selector_Name (New_Nam), False);
5496 Set_Parent (New_Nam, Parent (Parent (Nam)));
5497 Analyze_Selected_Component (New_Nam);
5498 Get_First_Interp (Selector_Name (New_Nam), X, It);
5499 else
5500 Get_First_Interp (Nam, X, It);
5501 end if;
5503 while Present (It.Nam) loop
5504 if Etype (It.Nam) = Standard_Void_Type then
5505 Void_Interp_Seen := True;
5506 end if;
5508 Analyze_One_Call (N, It.Nam, True, Success);
5509 Get_Next_Interp (X, It);
5510 end loop;
5512 if Nkind (N) = N_Function_Call then
5513 Get_First_Interp (Nam, X, It);
5514 while Present (It.Nam) loop
5515 if Ekind_In (It.Nam, E_Function, E_Operator) then
5516 return;
5517 else
5518 Get_Next_Interp (X, It);
5519 end if;
5520 end loop;
5522 -- If all interpretations are procedures, this deserves a
5523 -- more precise message. Ditto if this appears as the prefix
5524 -- of a selected component, which may be a lexical error.
5526 Error_Msg_N
5527 ("\context requires function call, found procedure name", Nam);
5529 if Nkind (Parent (N)) = N_Selected_Component
5530 and then N = Prefix (Parent (N))
5531 then
5532 Error_Msg_N -- CODEFIX
5533 ("\period should probably be semicolon", Parent (N));
5534 end if;
5536 elsif Nkind (N) = N_Procedure_Call_Statement
5537 and then not Void_Interp_Seen
5538 then
5539 Error_Msg_N (
5540 "\function name found in procedure call", Nam);
5541 end if;
5543 All_Errors_Mode := Err_Mode;
5544 end Diagnose_Call;
5546 ---------------------------
5547 -- Find_Arithmetic_Types --
5548 ---------------------------
5550 procedure Find_Arithmetic_Types
5551 (L, R : Node_Id;
5552 Op_Id : Entity_Id;
5553 N : Node_Id)
5555 Index1 : Interp_Index;
5556 Index2 : Interp_Index;
5557 It1 : Interp;
5558 It2 : Interp;
5560 procedure Check_Right_Argument (T : Entity_Id);
5561 -- Check right operand of operator
5563 --------------------------
5564 -- Check_Right_Argument --
5565 --------------------------
5567 procedure Check_Right_Argument (T : Entity_Id) is
5568 begin
5569 if not Is_Overloaded (R) then
5570 Check_Arithmetic_Pair (T, Etype (R), Op_Id, N);
5571 else
5572 Get_First_Interp (R, Index2, It2);
5573 while Present (It2.Typ) loop
5574 Check_Arithmetic_Pair (T, It2.Typ, Op_Id, N);
5575 Get_Next_Interp (Index2, It2);
5576 end loop;
5577 end if;
5578 end Check_Right_Argument;
5580 -- Start of processing for Find_Arithmetic_Types
5582 begin
5583 if not Is_Overloaded (L) then
5584 Check_Right_Argument (Etype (L));
5586 else
5587 Get_First_Interp (L, Index1, It1);
5588 while Present (It1.Typ) loop
5589 Check_Right_Argument (It1.Typ);
5590 Get_Next_Interp (Index1, It1);
5591 end loop;
5592 end if;
5594 end Find_Arithmetic_Types;
5596 ------------------------
5597 -- Find_Boolean_Types --
5598 ------------------------
5600 procedure Find_Boolean_Types
5601 (L, R : Node_Id;
5602 Op_Id : Entity_Id;
5603 N : Node_Id)
5605 Index : Interp_Index;
5606 It : Interp;
5608 procedure Check_Numeric_Argument (T : Entity_Id);
5609 -- Special case for logical operations one of whose operands is an
5610 -- integer literal. If both are literal the result is any modular type.
5612 ----------------------------
5613 -- Check_Numeric_Argument --
5614 ----------------------------
5616 procedure Check_Numeric_Argument (T : Entity_Id) is
5617 begin
5618 if T = Universal_Integer then
5619 Add_One_Interp (N, Op_Id, Any_Modular);
5621 elsif Is_Modular_Integer_Type (T) then
5622 Add_One_Interp (N, Op_Id, T);
5623 end if;
5624 end Check_Numeric_Argument;
5626 -- Start of processing for Find_Boolean_Types
5628 begin
5629 if not Is_Overloaded (L) then
5630 if Etype (L) = Universal_Integer
5631 or else Etype (L) = Any_Modular
5632 then
5633 if not Is_Overloaded (R) then
5634 Check_Numeric_Argument (Etype (R));
5636 else
5637 Get_First_Interp (R, Index, It);
5638 while Present (It.Typ) loop
5639 Check_Numeric_Argument (It.Typ);
5640 Get_Next_Interp (Index, It);
5641 end loop;
5642 end if;
5644 -- If operands are aggregates, we must assume that they may be
5645 -- boolean arrays, and leave disambiguation for the second pass.
5646 -- If only one is an aggregate, verify that the other one has an
5647 -- interpretation as a boolean array
5649 elsif Nkind (L) = N_Aggregate then
5650 if Nkind (R) = N_Aggregate then
5651 Add_One_Interp (N, Op_Id, Etype (L));
5653 elsif not Is_Overloaded (R) then
5654 if Valid_Boolean_Arg (Etype (R)) then
5655 Add_One_Interp (N, Op_Id, Etype (R));
5656 end if;
5658 else
5659 Get_First_Interp (R, Index, It);
5660 while Present (It.Typ) loop
5661 if Valid_Boolean_Arg (It.Typ) then
5662 Add_One_Interp (N, Op_Id, It.Typ);
5663 end if;
5665 Get_Next_Interp (Index, It);
5666 end loop;
5667 end if;
5669 elsif Valid_Boolean_Arg (Etype (L))
5670 and then Has_Compatible_Type (R, Etype (L))
5671 then
5672 Add_One_Interp (N, Op_Id, Etype (L));
5673 end if;
5675 else
5676 Get_First_Interp (L, Index, It);
5677 while Present (It.Typ) loop
5678 if Valid_Boolean_Arg (It.Typ)
5679 and then Has_Compatible_Type (R, It.Typ)
5680 then
5681 Add_One_Interp (N, Op_Id, It.Typ);
5682 end if;
5684 Get_Next_Interp (Index, It);
5685 end loop;
5686 end if;
5687 end Find_Boolean_Types;
5689 ---------------------------
5690 -- Find_Comparison_Types --
5691 ---------------------------
5693 procedure Find_Comparison_Types
5694 (L, R : Node_Id;
5695 Op_Id : Entity_Id;
5696 N : Node_Id)
5698 Index : Interp_Index;
5699 It : Interp;
5700 Found : Boolean := False;
5701 I_F : Interp_Index;
5702 T_F : Entity_Id;
5703 Scop : Entity_Id := Empty;
5705 procedure Try_One_Interp (T1 : Entity_Id);
5706 -- Routine to try one proposed interpretation. Note that the context
5707 -- of the operator plays no role in resolving the arguments, so that
5708 -- if there is more than one interpretation of the operands that is
5709 -- compatible with comparison, the operation is ambiguous.
5711 --------------------
5712 -- Try_One_Interp --
5713 --------------------
5715 procedure Try_One_Interp (T1 : Entity_Id) is
5716 begin
5718 -- If the operator is an expanded name, then the type of the operand
5719 -- must be defined in the corresponding scope. If the type is
5720 -- universal, the context will impose the correct type.
5722 if Present (Scop)
5723 and then not Defined_In_Scope (T1, Scop)
5724 and then T1 /= Universal_Integer
5725 and then T1 /= Universal_Real
5726 and then T1 /= Any_String
5727 and then T1 /= Any_Composite
5728 then
5729 return;
5730 end if;
5732 if Valid_Comparison_Arg (T1) and then Has_Compatible_Type (R, T1) then
5733 if Found and then Base_Type (T1) /= Base_Type (T_F) then
5734 It := Disambiguate (L, I_F, Index, Any_Type);
5736 if It = No_Interp then
5737 Ambiguous_Operands (N);
5738 Set_Etype (L, Any_Type);
5739 return;
5741 else
5742 T_F := It.Typ;
5743 end if;
5745 else
5746 Found := True;
5747 T_F := T1;
5748 I_F := Index;
5749 end if;
5751 Set_Etype (L, T_F);
5752 Find_Non_Universal_Interpretations (N, R, Op_Id, T1);
5754 end if;
5755 end Try_One_Interp;
5757 -- Start of processing for Find_Comparison_Types
5759 begin
5760 -- If left operand is aggregate, the right operand has to
5761 -- provide a usable type for it.
5763 if Nkind (L) = N_Aggregate and then Nkind (R) /= N_Aggregate then
5764 Find_Comparison_Types (L => R, R => L, Op_Id => Op_Id, N => N);
5765 return;
5766 end if;
5768 if Nkind (N) = N_Function_Call
5769 and then Nkind (Name (N)) = N_Expanded_Name
5770 then
5771 Scop := Entity (Prefix (Name (N)));
5773 -- The prefix may be a package renaming, and the subsequent test
5774 -- requires the original package.
5776 if Ekind (Scop) = E_Package
5777 and then Present (Renamed_Entity (Scop))
5778 then
5779 Scop := Renamed_Entity (Scop);
5780 Set_Entity (Prefix (Name (N)), Scop);
5781 end if;
5782 end if;
5784 if not Is_Overloaded (L) then
5785 Try_One_Interp (Etype (L));
5787 else
5788 Get_First_Interp (L, Index, It);
5789 while Present (It.Typ) loop
5790 Try_One_Interp (It.Typ);
5791 Get_Next_Interp (Index, It);
5792 end loop;
5793 end if;
5794 end Find_Comparison_Types;
5796 ----------------------------------------
5797 -- Find_Non_Universal_Interpretations --
5798 ----------------------------------------
5800 procedure Find_Non_Universal_Interpretations
5801 (N : Node_Id;
5802 R : Node_Id;
5803 Op_Id : Entity_Id;
5804 T1 : Entity_Id)
5806 Index : Interp_Index;
5807 It : Interp;
5809 begin
5810 if T1 = Universal_Integer or else T1 = Universal_Real
5812 -- If the left operand of an equality operator is null, the visibility
5813 -- of the operator must be determined from the interpretation of the
5814 -- right operand. This processing must be done for Any_Access, which
5815 -- is the internal representation of the type of the literal null.
5817 or else T1 = Any_Access
5818 then
5819 if not Is_Overloaded (R) then
5820 Add_One_Interp (N, Op_Id, Standard_Boolean, Base_Type (Etype (R)));
5821 else
5822 Get_First_Interp (R, Index, It);
5823 while Present (It.Typ) loop
5824 if Covers (It.Typ, T1) then
5825 Add_One_Interp
5826 (N, Op_Id, Standard_Boolean, Base_Type (It.Typ));
5827 end if;
5829 Get_Next_Interp (Index, It);
5830 end loop;
5831 end if;
5832 else
5833 Add_One_Interp (N, Op_Id, Standard_Boolean, Base_Type (T1));
5834 end if;
5835 end Find_Non_Universal_Interpretations;
5837 ------------------------------
5838 -- Find_Concatenation_Types --
5839 ------------------------------
5841 procedure Find_Concatenation_Types
5842 (L, R : Node_Id;
5843 Op_Id : Entity_Id;
5844 N : Node_Id)
5846 Op_Type : constant Entity_Id := Etype (Op_Id);
5848 begin
5849 if Is_Array_Type (Op_Type)
5850 and then not Is_Limited_Type (Op_Type)
5852 and then (Has_Compatible_Type (L, Op_Type)
5853 or else
5854 Has_Compatible_Type (L, Component_Type (Op_Type)))
5856 and then (Has_Compatible_Type (R, Op_Type)
5857 or else
5858 Has_Compatible_Type (R, Component_Type (Op_Type)))
5859 then
5860 Add_One_Interp (N, Op_Id, Op_Type);
5861 end if;
5862 end Find_Concatenation_Types;
5864 -------------------------
5865 -- Find_Equality_Types --
5866 -------------------------
5868 procedure Find_Equality_Types
5869 (L, R : Node_Id;
5870 Op_Id : Entity_Id;
5871 N : Node_Id)
5873 Index : Interp_Index;
5874 It : Interp;
5875 Found : Boolean := False;
5876 I_F : Interp_Index;
5877 T_F : Entity_Id;
5878 Scop : Entity_Id := Empty;
5880 procedure Try_One_Interp (T1 : Entity_Id);
5881 -- The context of the equality operator plays no role in resolving the
5882 -- arguments, so that if there is more than one interpretation of the
5883 -- operands that is compatible with equality, the construct is ambiguous
5884 -- and an error can be emitted now, after trying to disambiguate, i.e.
5885 -- applying preference rules.
5887 --------------------
5888 -- Try_One_Interp --
5889 --------------------
5891 procedure Try_One_Interp (T1 : Entity_Id) is
5892 Bas : constant Entity_Id := Base_Type (T1);
5894 begin
5895 -- If the operator is an expanded name, then the type of the operand
5896 -- must be defined in the corresponding scope. If the type is
5897 -- universal, the context will impose the correct type. An anonymous
5898 -- type for a 'Access reference is also universal in this sense, as
5899 -- the actual type is obtained from context.
5901 -- In Ada 2005, the equality operator for anonymous access types
5902 -- is declared in Standard, and preference rules apply to it.
5904 if Present (Scop) then
5905 if Defined_In_Scope (T1, Scop)
5906 or else T1 = Universal_Integer
5907 or else T1 = Universal_Real
5908 or else T1 = Any_Access
5909 or else T1 = Any_String
5910 or else T1 = Any_Composite
5911 or else (Ekind (T1) = E_Access_Subprogram_Type
5912 and then not Comes_From_Source (T1))
5913 then
5914 null;
5916 elsif Ekind (T1) = E_Anonymous_Access_Type
5917 and then Scop = Standard_Standard
5918 then
5919 null;
5921 else
5922 -- The scope does not contain an operator for the type
5924 return;
5925 end if;
5927 -- If we have infix notation, the operator must be usable. Within
5928 -- an instance, if the type is already established we know it is
5929 -- correct. If an operand is universal it is compatible with any
5930 -- numeric type.
5932 elsif In_Open_Scopes (Scope (Bas))
5933 or else Is_Potentially_Use_Visible (Bas)
5934 or else In_Use (Bas)
5935 or else (In_Use (Scope (Bas)) and then not Is_Hidden (Bas))
5937 -- In an instance, the type may have been immediately visible.
5938 -- Either the types are compatible, or one operand is universal
5939 -- (numeric or null).
5941 or else (In_Instance
5942 and then
5943 (First_Subtype (T1) = First_Subtype (Etype (R))
5944 or else Nkind (R) = N_Null
5945 or else
5946 (Is_Numeric_Type (T1)
5947 and then Is_Universal_Numeric_Type (Etype (R)))))
5949 -- In Ada 2005, the equality on anonymous access types is declared
5950 -- in Standard, and is always visible.
5952 or else Ekind (T1) = E_Anonymous_Access_Type
5953 then
5954 null;
5956 else
5957 -- Save candidate type for subsequent error message, if any
5959 if not Is_Limited_Type (T1) then
5960 Candidate_Type := T1;
5961 end if;
5963 return;
5964 end if;
5966 -- Ada 2005 (AI-230): Keep restriction imposed by Ada 83 and 95:
5967 -- Do not allow anonymous access types in equality operators.
5969 if Ada_Version < Ada_2005
5970 and then Ekind (T1) = E_Anonymous_Access_Type
5971 then
5972 return;
5973 end if;
5975 -- If the right operand has a type compatible with T1, check for an
5976 -- acceptable interpretation, unless T1 is limited (no predefined
5977 -- equality available), or this is use of a "/=" for a tagged type.
5978 -- In the latter case, possible interpretations of equality need
5979 -- to be considered, we don't want the default inequality declared
5980 -- in Standard to be chosen, and the "/=" will be rewritten as a
5981 -- negation of "=" (see the end of Analyze_Equality_Op). This ensures
5982 -- that that rewriting happens during analysis rather than being
5983 -- delayed until expansion (this is needed for ASIS, which only sees
5984 -- the unexpanded tree). Note that if the node is N_Op_Ne, but Op_Id
5985 -- is Name_Op_Eq then we still proceed with the interpretation,
5986 -- because that indicates the potential rewriting case where the
5987 -- interpretation to consider is actually "=" and the node may be
5988 -- about to be rewritten by Analyze_Equality_Op.
5990 if T1 /= Standard_Void_Type
5991 and then Has_Compatible_Type (R, T1)
5993 and then
5994 ((not Is_Limited_Type (T1)
5995 and then not Is_Limited_Composite (T1))
5997 or else
5998 (Is_Array_Type (T1)
5999 and then not Is_Limited_Type (Component_Type (T1))
6000 and then Available_Full_View_Of_Component (T1)))
6002 and then
6003 (Nkind (N) /= N_Op_Ne
6004 or else not Is_Tagged_Type (T1)
6005 or else Chars (Op_Id) = Name_Op_Eq)
6006 then
6007 if Found
6008 and then Base_Type (T1) /= Base_Type (T_F)
6009 then
6010 It := Disambiguate (L, I_F, Index, Any_Type);
6012 if It = No_Interp then
6013 Ambiguous_Operands (N);
6014 Set_Etype (L, Any_Type);
6015 return;
6017 else
6018 T_F := It.Typ;
6019 end if;
6021 else
6022 Found := True;
6023 T_F := T1;
6024 I_F := Index;
6025 end if;
6027 if not Analyzed (L) then
6028 Set_Etype (L, T_F);
6029 end if;
6031 Find_Non_Universal_Interpretations (N, R, Op_Id, T1);
6033 -- Case of operator was not visible, Etype still set to Any_Type
6035 if Etype (N) = Any_Type then
6036 Found := False;
6037 end if;
6039 elsif Scop = Standard_Standard
6040 and then Ekind (T1) = E_Anonymous_Access_Type
6041 then
6042 Found := True;
6043 end if;
6044 end Try_One_Interp;
6046 -- Start of processing for Find_Equality_Types
6048 begin
6049 -- If left operand is aggregate, the right operand has to
6050 -- provide a usable type for it.
6052 if Nkind (L) = N_Aggregate
6053 and then Nkind (R) /= N_Aggregate
6054 then
6055 Find_Equality_Types (L => R, R => L, Op_Id => Op_Id, N => N);
6056 return;
6057 end if;
6059 if Nkind (N) = N_Function_Call
6060 and then Nkind (Name (N)) = N_Expanded_Name
6061 then
6062 Scop := Entity (Prefix (Name (N)));
6064 -- The prefix may be a package renaming, and the subsequent test
6065 -- requires the original package.
6067 if Ekind (Scop) = E_Package
6068 and then Present (Renamed_Entity (Scop))
6069 then
6070 Scop := Renamed_Entity (Scop);
6071 Set_Entity (Prefix (Name (N)), Scop);
6072 end if;
6073 end if;
6075 if not Is_Overloaded (L) then
6076 Try_One_Interp (Etype (L));
6078 else
6079 Get_First_Interp (L, Index, It);
6080 while Present (It.Typ) loop
6081 Try_One_Interp (It.Typ);
6082 Get_Next_Interp (Index, It);
6083 end loop;
6084 end if;
6085 end Find_Equality_Types;
6087 -------------------------
6088 -- Find_Negation_Types --
6089 -------------------------
6091 procedure Find_Negation_Types
6092 (R : Node_Id;
6093 Op_Id : Entity_Id;
6094 N : Node_Id)
6096 Index : Interp_Index;
6097 It : Interp;
6099 begin
6100 if not Is_Overloaded (R) then
6101 if Etype (R) = Universal_Integer then
6102 Add_One_Interp (N, Op_Id, Any_Modular);
6103 elsif Valid_Boolean_Arg (Etype (R)) then
6104 Add_One_Interp (N, Op_Id, Etype (R));
6105 end if;
6107 else
6108 Get_First_Interp (R, Index, It);
6109 while Present (It.Typ) loop
6110 if Valid_Boolean_Arg (It.Typ) then
6111 Add_One_Interp (N, Op_Id, It.Typ);
6112 end if;
6114 Get_Next_Interp (Index, It);
6115 end loop;
6116 end if;
6117 end Find_Negation_Types;
6119 ------------------------------
6120 -- Find_Primitive_Operation --
6121 ------------------------------
6123 function Find_Primitive_Operation (N : Node_Id) return Boolean is
6124 Obj : constant Node_Id := Prefix (N);
6125 Op : constant Node_Id := Selector_Name (N);
6127 Prim : Elmt_Id;
6128 Prims : Elist_Id;
6129 Typ : Entity_Id;
6131 begin
6132 Set_Etype (Op, Any_Type);
6134 if Is_Access_Type (Etype (Obj)) then
6135 Typ := Designated_Type (Etype (Obj));
6136 else
6137 Typ := Etype (Obj);
6138 end if;
6140 if Is_Class_Wide_Type (Typ) then
6141 Typ := Root_Type (Typ);
6142 end if;
6144 Prims := Primitive_Operations (Typ);
6146 Prim := First_Elmt (Prims);
6147 while Present (Prim) loop
6148 if Chars (Node (Prim)) = Chars (Op) then
6149 Add_One_Interp (Op, Node (Prim), Etype (Node (Prim)));
6150 Set_Etype (N, Etype (Node (Prim)));
6151 end if;
6153 Next_Elmt (Prim);
6154 end loop;
6156 -- Now look for class-wide operations of the type or any of its
6157 -- ancestors by iterating over the homonyms of the selector.
6159 declare
6160 Cls_Type : constant Entity_Id := Class_Wide_Type (Typ);
6161 Hom : Entity_Id;
6163 begin
6164 Hom := Current_Entity (Op);
6165 while Present (Hom) loop
6166 if (Ekind (Hom) = E_Procedure
6167 or else
6168 Ekind (Hom) = E_Function)
6169 and then Scope (Hom) = Scope (Typ)
6170 and then Present (First_Formal (Hom))
6171 and then
6172 (Base_Type (Etype (First_Formal (Hom))) = Cls_Type
6173 or else
6174 (Is_Access_Type (Etype (First_Formal (Hom)))
6175 and then
6176 Ekind (Etype (First_Formal (Hom))) =
6177 E_Anonymous_Access_Type
6178 and then
6179 Base_Type
6180 (Designated_Type (Etype (First_Formal (Hom)))) =
6181 Cls_Type))
6182 then
6183 Add_One_Interp (Op, Hom, Etype (Hom));
6184 Set_Etype (N, Etype (Hom));
6185 end if;
6187 Hom := Homonym (Hom);
6188 end loop;
6189 end;
6191 return Etype (Op) /= Any_Type;
6192 end Find_Primitive_Operation;
6194 ----------------------
6195 -- Find_Unary_Types --
6196 ----------------------
6198 procedure Find_Unary_Types
6199 (R : Node_Id;
6200 Op_Id : Entity_Id;
6201 N : Node_Id)
6203 Index : Interp_Index;
6204 It : Interp;
6206 begin
6207 if not Is_Overloaded (R) then
6208 if Is_Numeric_Type (Etype (R)) then
6210 -- In an instance a generic actual may be a numeric type even if
6211 -- the formal in the generic unit was not. In that case, the
6212 -- predefined operator was not a possible interpretation in the
6213 -- generic, and cannot be one in the instance, unless the operator
6214 -- is an actual of an instance.
6216 if In_Instance
6217 and then
6218 not Is_Numeric_Type (Corresponding_Generic_Type (Etype (R)))
6219 then
6220 null;
6221 else
6222 Add_One_Interp (N, Op_Id, Base_Type (Etype (R)));
6223 end if;
6224 end if;
6226 else
6227 Get_First_Interp (R, Index, It);
6228 while Present (It.Typ) loop
6229 if Is_Numeric_Type (It.Typ) then
6230 if In_Instance
6231 and then
6232 not Is_Numeric_Type
6233 (Corresponding_Generic_Type (Etype (It.Typ)))
6234 then
6235 null;
6237 else
6238 Add_One_Interp (N, Op_Id, Base_Type (It.Typ));
6239 end if;
6240 end if;
6242 Get_Next_Interp (Index, It);
6243 end loop;
6244 end if;
6245 end Find_Unary_Types;
6247 ------------------
6248 -- Junk_Operand --
6249 ------------------
6251 function Junk_Operand (N : Node_Id) return Boolean is
6252 Enode : Node_Id;
6254 begin
6255 if Error_Posted (N) then
6256 return False;
6257 end if;
6259 -- Get entity to be tested
6261 if Is_Entity_Name (N)
6262 and then Present (Entity (N))
6263 then
6264 Enode := N;
6266 -- An odd case, a procedure name gets converted to a very peculiar
6267 -- function call, and here is where we detect this happening.
6269 elsif Nkind (N) = N_Function_Call
6270 and then Is_Entity_Name (Name (N))
6271 and then Present (Entity (Name (N)))
6272 then
6273 Enode := Name (N);
6275 -- Another odd case, there are at least some cases of selected
6276 -- components where the selected component is not marked as having
6277 -- an entity, even though the selector does have an entity
6279 elsif Nkind (N) = N_Selected_Component
6280 and then Present (Entity (Selector_Name (N)))
6281 then
6282 Enode := Selector_Name (N);
6284 else
6285 return False;
6286 end if;
6288 -- Now test the entity we got to see if it is a bad case
6290 case Ekind (Entity (Enode)) is
6292 when E_Package =>
6293 Error_Msg_N
6294 ("package name cannot be used as operand", Enode);
6296 when Generic_Unit_Kind =>
6297 Error_Msg_N
6298 ("generic unit name cannot be used as operand", Enode);
6300 when Type_Kind =>
6301 Error_Msg_N
6302 ("subtype name cannot be used as operand", Enode);
6304 when Entry_Kind =>
6305 Error_Msg_N
6306 ("entry name cannot be used as operand", Enode);
6308 when E_Procedure =>
6309 Error_Msg_N
6310 ("procedure name cannot be used as operand", Enode);
6312 when E_Exception =>
6313 Error_Msg_N
6314 ("exception name cannot be used as operand", Enode);
6316 when E_Block | E_Label | E_Loop =>
6317 Error_Msg_N
6318 ("label name cannot be used as operand", Enode);
6320 when others =>
6321 return False;
6323 end case;
6325 return True;
6326 end Junk_Operand;
6328 --------------------
6329 -- Operator_Check --
6330 --------------------
6332 procedure Operator_Check (N : Node_Id) is
6333 begin
6334 Remove_Abstract_Operations (N);
6336 -- Test for case of no interpretation found for operator
6338 if Etype (N) = Any_Type then
6339 declare
6340 L : Node_Id;
6341 R : Node_Id;
6342 Op_Id : Entity_Id := Empty;
6344 begin
6345 R := Right_Opnd (N);
6347 if Nkind (N) in N_Binary_Op then
6348 L := Left_Opnd (N);
6349 else
6350 L := Empty;
6351 end if;
6353 -- If either operand has no type, then don't complain further,
6354 -- since this simply means that we have a propagated error.
6356 if R = Error
6357 or else Etype (R) = Any_Type
6358 or else (Nkind (N) in N_Binary_Op and then Etype (L) = Any_Type)
6359 then
6360 -- For the rather unusual case where one of the operands is
6361 -- a Raise_Expression, whose initial type is Any_Type, use
6362 -- the type of the other operand.
6364 if Nkind (L) = N_Raise_Expression then
6365 Set_Etype (L, Etype (R));
6366 Set_Etype (N, Etype (R));
6368 elsif Nkind (R) = N_Raise_Expression then
6369 Set_Etype (R, Etype (L));
6370 Set_Etype (N, Etype (L));
6371 end if;
6373 return;
6375 -- We explicitly check for the case of concatenation of component
6376 -- with component to avoid reporting spurious matching array types
6377 -- that might happen to be lurking in distant packages (such as
6378 -- run-time packages). This also prevents inconsistencies in the
6379 -- messages for certain ACVC B tests, which can vary depending on
6380 -- types declared in run-time interfaces. Another improvement when
6381 -- aggregates are present is to look for a well-typed operand.
6383 elsif Present (Candidate_Type)
6384 and then (Nkind (N) /= N_Op_Concat
6385 or else Is_Array_Type (Etype (L))
6386 or else Is_Array_Type (Etype (R)))
6387 then
6388 if Nkind (N) = N_Op_Concat then
6389 if Etype (L) /= Any_Composite
6390 and then Is_Array_Type (Etype (L))
6391 then
6392 Candidate_Type := Etype (L);
6394 elsif Etype (R) /= Any_Composite
6395 and then Is_Array_Type (Etype (R))
6396 then
6397 Candidate_Type := Etype (R);
6398 end if;
6399 end if;
6401 Error_Msg_NE -- CODEFIX
6402 ("operator for} is not directly visible!",
6403 N, First_Subtype (Candidate_Type));
6405 declare
6406 U : constant Node_Id :=
6407 Cunit (Get_Source_Unit (Candidate_Type));
6408 begin
6409 if Unit_Is_Visible (U) then
6410 Error_Msg_N -- CODEFIX
6411 ("use clause would make operation legal!", N);
6412 else
6413 Error_Msg_NE -- CODEFIX
6414 ("add with_clause and use_clause for&!",
6415 N, Defining_Entity (Unit (U)));
6416 end if;
6417 end;
6418 return;
6420 -- If either operand is a junk operand (e.g. package name), then
6421 -- post appropriate error messages, but do not complain further.
6423 -- Note that the use of OR in this test instead of OR ELSE is
6424 -- quite deliberate, we may as well check both operands in the
6425 -- binary operator case.
6427 elsif Junk_Operand (R)
6428 or -- really mean OR here and not OR ELSE, see above
6429 (Nkind (N) in N_Binary_Op and then Junk_Operand (L))
6430 then
6431 return;
6433 -- If we have a logical operator, one of whose operands is
6434 -- Boolean, then we know that the other operand cannot resolve to
6435 -- Boolean (since we got no interpretations), but in that case we
6436 -- pretty much know that the other operand should be Boolean, so
6437 -- resolve it that way (generating an error)
6439 elsif Nkind_In (N, N_Op_And, N_Op_Or, N_Op_Xor) then
6440 if Etype (L) = Standard_Boolean then
6441 Resolve (R, Standard_Boolean);
6442 return;
6443 elsif Etype (R) = Standard_Boolean then
6444 Resolve (L, Standard_Boolean);
6445 return;
6446 end if;
6448 -- For an arithmetic operator or comparison operator, if one
6449 -- of the operands is numeric, then we know the other operand
6450 -- is not the same numeric type. If it is a non-numeric type,
6451 -- then probably it is intended to match the other operand.
6453 elsif Nkind_In (N, N_Op_Add,
6454 N_Op_Divide,
6455 N_Op_Ge,
6456 N_Op_Gt,
6457 N_Op_Le)
6458 or else
6459 Nkind_In (N, N_Op_Lt,
6460 N_Op_Mod,
6461 N_Op_Multiply,
6462 N_Op_Rem,
6463 N_Op_Subtract)
6464 then
6465 -- If Allow_Integer_Address is active, check whether the
6466 -- operation becomes legal after converting an operand.
6468 if Is_Numeric_Type (Etype (L))
6469 and then not Is_Numeric_Type (Etype (R))
6470 then
6471 if Address_Integer_Convert_OK (Etype (R), Etype (L)) then
6472 Rewrite (R,
6473 Unchecked_Convert_To (Etype (L), Relocate_Node (R)));
6474 Analyze_Arithmetic_Op (N);
6476 else
6477 Resolve (R, Etype (L));
6478 end if;
6479 return;
6481 elsif Is_Numeric_Type (Etype (R))
6482 and then not Is_Numeric_Type (Etype (L))
6483 then
6484 if Address_Integer_Convert_OK (Etype (L), Etype (R)) then
6485 Rewrite (L,
6486 Unchecked_Convert_To (Etype (R), Relocate_Node (L)));
6487 Analyze_Arithmetic_Op (N);
6488 return;
6490 else
6491 Resolve (L, Etype (R));
6492 end if;
6494 return;
6496 elsif Allow_Integer_Address
6497 and then Is_Descendent_Of_Address (Etype (L))
6498 and then Is_Descendent_Of_Address (Etype (R))
6499 and then not Error_Posted (N)
6500 then
6501 declare
6502 Addr_Type : constant Entity_Id := Etype (L);
6504 begin
6505 Rewrite (L,
6506 Unchecked_Convert_To (
6507 Standard_Integer, Relocate_Node (L)));
6508 Rewrite (R,
6509 Unchecked_Convert_To (
6510 Standard_Integer, Relocate_Node (R)));
6511 Analyze_Arithmetic_Op (N);
6513 -- If this is an operand in an enclosing arithmetic
6514 -- operation, Convert the result as an address so that
6515 -- arithmetic folding of address can continue.
6517 if Nkind (Parent (N)) in N_Op then
6518 Rewrite (N,
6519 Unchecked_Convert_To (Addr_Type, Relocate_Node (N)));
6520 end if;
6522 return;
6523 end;
6524 end if;
6526 -- Comparisons on A'Access are common enough to deserve a
6527 -- special message.
6529 elsif Nkind_In (N, N_Op_Eq, N_Op_Ne)
6530 and then Ekind (Etype (L)) = E_Access_Attribute_Type
6531 and then Ekind (Etype (R)) = E_Access_Attribute_Type
6532 then
6533 Error_Msg_N
6534 ("two access attributes cannot be compared directly", N);
6535 Error_Msg_N
6536 ("\use qualified expression for one of the operands",
6538 return;
6540 -- Another one for C programmers
6542 elsif Nkind (N) = N_Op_Concat
6543 and then Valid_Boolean_Arg (Etype (L))
6544 and then Valid_Boolean_Arg (Etype (R))
6545 then
6546 Error_Msg_N ("invalid operands for concatenation", N);
6547 Error_Msg_N -- CODEFIX
6548 ("\maybe AND was meant", N);
6549 return;
6551 -- A special case for comparison of access parameter with null
6553 elsif Nkind (N) = N_Op_Eq
6554 and then Is_Entity_Name (L)
6555 and then Nkind (Parent (Entity (L))) = N_Parameter_Specification
6556 and then Nkind (Parameter_Type (Parent (Entity (L)))) =
6557 N_Access_Definition
6558 and then Nkind (R) = N_Null
6559 then
6560 Error_Msg_N ("access parameter is not allowed to be null", L);
6561 Error_Msg_N ("\(call would raise Constraint_Error)", L);
6562 return;
6564 -- Another special case for exponentiation, where the right
6565 -- operand must be Natural, independently of the base.
6567 elsif Nkind (N) = N_Op_Expon
6568 and then Is_Numeric_Type (Etype (L))
6569 and then not Is_Overloaded (R)
6570 and then
6571 First_Subtype (Base_Type (Etype (R))) /= Standard_Integer
6572 and then Base_Type (Etype (R)) /= Universal_Integer
6573 then
6574 if Ada_Version >= Ada_2012
6575 and then Has_Dimension_System (Etype (L))
6576 then
6577 Error_Msg_NE
6578 ("exponent for dimensioned type must be a rational" &
6579 ", found}", R, Etype (R));
6580 else
6581 Error_Msg_NE
6582 ("exponent must be of type Natural, found}", R, Etype (R));
6583 end if;
6585 return;
6586 end if;
6588 -- If we fall through then just give general message. Note that in
6589 -- the following messages, if the operand is overloaded we choose
6590 -- an arbitrary type to complain about, but that is probably more
6591 -- useful than not giving a type at all.
6593 if Nkind (N) in N_Unary_Op then
6594 Error_Msg_Node_2 := Etype (R);
6595 Error_Msg_N ("operator& not defined for}", N);
6596 return;
6598 else
6599 if Nkind (N) in N_Binary_Op then
6600 if not Is_Overloaded (L)
6601 and then not Is_Overloaded (R)
6602 and then Base_Type (Etype (L)) = Base_Type (Etype (R))
6603 then
6604 Error_Msg_Node_2 := First_Subtype (Etype (R));
6605 Error_Msg_N ("there is no applicable operator& for}", N);
6607 else
6608 -- Another attempt to find a fix: one of the candidate
6609 -- interpretations may not be use-visible. This has
6610 -- already been checked for predefined operators, so
6611 -- we examine only user-defined functions.
6613 Op_Id := Get_Name_Entity_Id (Chars (N));
6615 while Present (Op_Id) loop
6616 if Ekind (Op_Id) /= E_Operator
6617 and then Is_Overloadable (Op_Id)
6618 then
6619 if not Is_Immediately_Visible (Op_Id)
6620 and then not In_Use (Scope (Op_Id))
6621 and then not Is_Abstract_Subprogram (Op_Id)
6622 and then not Is_Hidden (Op_Id)
6623 and then Ekind (Scope (Op_Id)) = E_Package
6624 and then
6625 Has_Compatible_Type
6626 (L, Etype (First_Formal (Op_Id)))
6627 and then Present
6628 (Next_Formal (First_Formal (Op_Id)))
6629 and then
6630 Has_Compatible_Type
6632 Etype (Next_Formal (First_Formal (Op_Id))))
6633 then
6634 Error_Msg_N
6635 ("No legal interpretation for operator&", N);
6636 Error_Msg_NE
6637 ("\use clause on& would make operation legal",
6638 N, Scope (Op_Id));
6639 exit;
6640 end if;
6641 end if;
6643 Op_Id := Homonym (Op_Id);
6644 end loop;
6646 if No (Op_Id) then
6647 Error_Msg_N ("invalid operand types for operator&", N);
6649 if Nkind (N) /= N_Op_Concat then
6650 Error_Msg_NE ("\left operand has}!", N, Etype (L));
6651 Error_Msg_NE ("\right operand has}!", N, Etype (R));
6653 -- For concatenation operators it is more difficult to
6654 -- determine which is the wrong operand. It is worth
6655 -- flagging explicitly an access type, for those who
6656 -- might think that a dereference happens here.
6658 elsif Is_Access_Type (Etype (L)) then
6659 Error_Msg_N ("\left operand is access type", N);
6661 elsif Is_Access_Type (Etype (R)) then
6662 Error_Msg_N ("\right operand is access type", N);
6663 end if;
6664 end if;
6665 end if;
6666 end if;
6667 end if;
6668 end;
6669 end if;
6670 end Operator_Check;
6672 -----------------------------------------
6673 -- Process_Implicit_Dereference_Prefix --
6674 -----------------------------------------
6676 function Process_Implicit_Dereference_Prefix
6677 (E : Entity_Id;
6678 P : Entity_Id) return Entity_Id
6680 Ref : Node_Id;
6681 Typ : constant Entity_Id := Designated_Type (Etype (P));
6683 begin
6684 if Present (E)
6685 and then (Operating_Mode = Check_Semantics or else not Expander_Active)
6686 then
6687 -- We create a dummy reference to E to ensure that the reference is
6688 -- not considered as part of an assignment (an implicit dereference
6689 -- can never assign to its prefix). The Comes_From_Source attribute
6690 -- needs to be propagated for accurate warnings.
6692 Ref := New_Occurrence_Of (E, Sloc (P));
6693 Set_Comes_From_Source (Ref, Comes_From_Source (P));
6694 Generate_Reference (E, Ref);
6695 end if;
6697 -- An implicit dereference is a legal occurrence of an incomplete type
6698 -- imported through a limited_with clause, if the full view is visible.
6700 if From_Limited_With (Typ)
6701 and then not From_Limited_With (Scope (Typ))
6702 and then
6703 (Is_Immediately_Visible (Scope (Typ))
6704 or else
6705 (Is_Child_Unit (Scope (Typ))
6706 and then Is_Visible_Lib_Unit (Scope (Typ))))
6707 then
6708 return Available_View (Typ);
6709 else
6710 return Typ;
6711 end if;
6712 end Process_Implicit_Dereference_Prefix;
6714 --------------------------------
6715 -- Remove_Abstract_Operations --
6716 --------------------------------
6718 procedure Remove_Abstract_Operations (N : Node_Id) is
6719 Abstract_Op : Entity_Id := Empty;
6720 Address_Kludge : Boolean := False;
6721 I : Interp_Index;
6722 It : Interp;
6724 -- AI-310: If overloaded, remove abstract non-dispatching operations. We
6725 -- activate this if either extensions are enabled, or if the abstract
6726 -- operation in question comes from a predefined file. This latter test
6727 -- allows us to use abstract to make operations invisible to users. In
6728 -- particular, if type Address is non-private and abstract subprograms
6729 -- are used to hide its operators, they will be truly hidden.
6731 type Operand_Position is (First_Op, Second_Op);
6732 Univ_Type : constant Entity_Id := Universal_Interpretation (N);
6734 procedure Remove_Address_Interpretations (Op : Operand_Position);
6735 -- Ambiguities may arise when the operands are literal and the address
6736 -- operations in s-auxdec are visible. In that case, remove the
6737 -- interpretation of a literal as Address, to retain the semantics
6738 -- of Address as a private type.
6740 ------------------------------------
6741 -- Remove_Address_Interpretations --
6742 ------------------------------------
6744 procedure Remove_Address_Interpretations (Op : Operand_Position) is
6745 Formal : Entity_Id;
6747 begin
6748 if Is_Overloaded (N) then
6749 Get_First_Interp (N, I, It);
6750 while Present (It.Nam) loop
6751 Formal := First_Entity (It.Nam);
6753 if Op = Second_Op then
6754 Formal := Next_Entity (Formal);
6755 end if;
6757 if Is_Descendent_Of_Address (Etype (Formal)) then
6758 Address_Kludge := True;
6759 Remove_Interp (I);
6760 end if;
6762 Get_Next_Interp (I, It);
6763 end loop;
6764 end if;
6765 end Remove_Address_Interpretations;
6767 -- Start of processing for Remove_Abstract_Operations
6769 begin
6770 if Is_Overloaded (N) then
6771 if Debug_Flag_V then
6772 Write_Str ("Remove_Abstract_Operations: ");
6773 Write_Overloads (N);
6774 end if;
6776 Get_First_Interp (N, I, It);
6778 while Present (It.Nam) loop
6779 if Is_Overloadable (It.Nam)
6780 and then Is_Abstract_Subprogram (It.Nam)
6781 and then not Is_Dispatching_Operation (It.Nam)
6782 then
6783 Abstract_Op := It.Nam;
6785 if Is_Descendent_Of_Address (It.Typ) then
6786 Address_Kludge := True;
6787 Remove_Interp (I);
6788 exit;
6790 -- In Ada 2005, this operation does not participate in overload
6791 -- resolution. If the operation is defined in a predefined
6792 -- unit, it is one of the operations declared abstract in some
6793 -- variants of System, and it must be removed as well.
6795 elsif Ada_Version >= Ada_2005
6796 or else Is_Predefined_File_Name
6797 (Unit_File_Name (Get_Source_Unit (It.Nam)))
6798 then
6799 Remove_Interp (I);
6800 exit;
6801 end if;
6802 end if;
6804 Get_Next_Interp (I, It);
6805 end loop;
6807 if No (Abstract_Op) then
6809 -- If some interpretation yields an integer type, it is still
6810 -- possible that there are address interpretations. Remove them
6811 -- if one operand is a literal, to avoid spurious ambiguities
6812 -- on systems where Address is a visible integer type.
6814 if Is_Overloaded (N)
6815 and then Nkind (N) in N_Op
6816 and then Is_Integer_Type (Etype (N))
6817 then
6818 if Nkind (N) in N_Binary_Op then
6819 if Nkind (Right_Opnd (N)) = N_Integer_Literal then
6820 Remove_Address_Interpretations (Second_Op);
6822 elsif Nkind (Right_Opnd (N)) = N_Integer_Literal then
6823 Remove_Address_Interpretations (First_Op);
6824 end if;
6825 end if;
6826 end if;
6828 elsif Nkind (N) in N_Op then
6830 -- Remove interpretations that treat literals as addresses. This
6831 -- is never appropriate, even when Address is defined as a visible
6832 -- Integer type. The reason is that we would really prefer Address
6833 -- to behave as a private type, even in this case, which is there
6834 -- only to accommodate oddities of VMS address sizes. If Address
6835 -- is a visible integer type, we get lots of overload ambiguities.
6837 if Nkind (N) in N_Binary_Op then
6838 declare
6839 U1 : constant Boolean :=
6840 Present (Universal_Interpretation (Right_Opnd (N)));
6841 U2 : constant Boolean :=
6842 Present (Universal_Interpretation (Left_Opnd (N)));
6844 begin
6845 if U1 then
6846 Remove_Address_Interpretations (Second_Op);
6847 end if;
6849 if U2 then
6850 Remove_Address_Interpretations (First_Op);
6851 end if;
6853 if not (U1 and U2) then
6855 -- Remove corresponding predefined operator, which is
6856 -- always added to the overload set.
6858 Get_First_Interp (N, I, It);
6859 while Present (It.Nam) loop
6860 if Scope (It.Nam) = Standard_Standard
6861 and then Base_Type (It.Typ) =
6862 Base_Type (Etype (Abstract_Op))
6863 then
6864 Remove_Interp (I);
6865 end if;
6867 Get_Next_Interp (I, It);
6868 end loop;
6870 elsif Is_Overloaded (N)
6871 and then Present (Univ_Type)
6872 then
6873 -- If both operands have a universal interpretation,
6874 -- it is still necessary to remove interpretations that
6875 -- yield Address. Any remaining ambiguities will be
6876 -- removed in Disambiguate.
6878 Get_First_Interp (N, I, It);
6879 while Present (It.Nam) loop
6880 if Is_Descendent_Of_Address (It.Typ) then
6881 Remove_Interp (I);
6883 elsif not Is_Type (It.Nam) then
6884 Set_Entity (N, It.Nam);
6885 end if;
6887 Get_Next_Interp (I, It);
6888 end loop;
6889 end if;
6890 end;
6891 end if;
6893 elsif Nkind (N) = N_Function_Call
6894 and then
6895 (Nkind (Name (N)) = N_Operator_Symbol
6896 or else
6897 (Nkind (Name (N)) = N_Expanded_Name
6898 and then
6899 Nkind (Selector_Name (Name (N))) = N_Operator_Symbol))
6900 then
6902 declare
6903 Arg1 : constant Node_Id := First (Parameter_Associations (N));
6904 U1 : constant Boolean :=
6905 Present (Universal_Interpretation (Arg1));
6906 U2 : constant Boolean :=
6907 Present (Next (Arg1)) and then
6908 Present (Universal_Interpretation (Next (Arg1)));
6910 begin
6911 if U1 then
6912 Remove_Address_Interpretations (First_Op);
6913 end if;
6915 if U2 then
6916 Remove_Address_Interpretations (Second_Op);
6917 end if;
6919 if not (U1 and U2) then
6920 Get_First_Interp (N, I, It);
6921 while Present (It.Nam) loop
6922 if Scope (It.Nam) = Standard_Standard
6923 and then It.Typ = Base_Type (Etype (Abstract_Op))
6924 then
6925 Remove_Interp (I);
6926 end if;
6928 Get_Next_Interp (I, It);
6929 end loop;
6930 end if;
6931 end;
6932 end if;
6934 -- If the removal has left no valid interpretations, emit an error
6935 -- message now and label node as illegal.
6937 if Present (Abstract_Op) then
6938 Get_First_Interp (N, I, It);
6940 if No (It.Nam) then
6942 -- Removal of abstract operation left no viable candidate
6944 Set_Etype (N, Any_Type);
6945 Error_Msg_Sloc := Sloc (Abstract_Op);
6946 Error_Msg_NE
6947 ("cannot call abstract operation& declared#", N, Abstract_Op);
6949 -- In Ada 2005, an abstract operation may disable predefined
6950 -- operators. Since the context is not yet known, we mark the
6951 -- predefined operators as potentially hidden. Do not include
6952 -- predefined operators when addresses are involved since this
6953 -- case is handled separately.
6955 elsif Ada_Version >= Ada_2005
6956 and then not Address_Kludge
6957 then
6958 while Present (It.Nam) loop
6959 if Is_Numeric_Type (It.Typ)
6960 and then Scope (It.Typ) = Standard_Standard
6961 then
6962 Set_Abstract_Op (I, Abstract_Op);
6963 end if;
6965 Get_Next_Interp (I, It);
6966 end loop;
6967 end if;
6968 end if;
6970 if Debug_Flag_V then
6971 Write_Str ("Remove_Abstract_Operations done: ");
6972 Write_Overloads (N);
6973 end if;
6974 end if;
6975 end Remove_Abstract_Operations;
6977 ----------------------------
6978 -- Try_Container_Indexing --
6979 ----------------------------
6981 function Try_Container_Indexing
6982 (N : Node_Id;
6983 Prefix : Node_Id;
6984 Exprs : List_Id) return Boolean
6986 Loc : constant Source_Ptr := Sloc (N);
6987 Assoc : List_Id;
6988 Disc : Entity_Id;
6989 Func : Entity_Id;
6990 Func_Name : Node_Id;
6991 Indexing : Node_Id;
6993 begin
6995 -- Check whether type has a specified indexing aspect
6997 Func_Name := Empty;
6999 if Is_Variable (Prefix) then
7000 Func_Name :=
7001 Find_Value_Of_Aspect (Etype (Prefix), Aspect_Variable_Indexing);
7002 end if;
7004 if No (Func_Name) then
7005 Func_Name :=
7006 Find_Value_Of_Aspect (Etype (Prefix), Aspect_Constant_Indexing);
7007 end if;
7009 -- If aspect does not exist the expression is illegal. Error is
7010 -- diagnosed in caller.
7012 if No (Func_Name) then
7014 -- The prefix itself may be an indexing of a container: rewrite
7015 -- as such and re-analyze.
7017 if Has_Implicit_Dereference (Etype (Prefix)) then
7018 Build_Explicit_Dereference
7019 (Prefix, First_Discriminant (Etype (Prefix)));
7020 return Try_Container_Indexing (N, Prefix, Exprs);
7022 else
7023 return False;
7024 end if;
7025 end if;
7027 Assoc := New_List (Relocate_Node (Prefix));
7029 -- A generalized indexing may have nore than one index expression, so
7030 -- transfer all of them to the argument list to be used in the call.
7031 -- Note that there may be named associations, in which case the node
7032 -- was rewritten earlier as a call, and has been transformed back into
7033 -- an indexed expression to share the following processing.
7035 -- The generalized indexing node is the one on which analysis and
7036 -- resolution take place. Before expansion the original node is replaced
7037 -- with the generalized indexing node, which is a call, possibly with
7038 -- a dereference operation.
7040 if Comes_From_Source (N) then
7041 Check_Compiler_Unit (N);
7042 end if;
7044 declare
7045 Arg : Node_Id;
7046 begin
7047 Arg := First (Exprs);
7048 while Present (Arg) loop
7049 Append (Relocate_Node (Arg), Assoc);
7050 Next (Arg);
7051 end loop;
7052 end;
7054 if not Is_Overloaded (Func_Name) then
7055 Func := Entity (Func_Name);
7056 Indexing :=
7057 Make_Function_Call (Loc,
7058 Name => New_Occurrence_Of (Func, Loc),
7059 Parameter_Associations => Assoc);
7060 Set_Parent (Indexing, Parent (N));
7061 Set_Generalized_Indexing (N, Indexing);
7062 Analyze (Indexing);
7063 Set_Etype (N, Etype (Indexing));
7065 -- If the return type of the indexing function is a reference type,
7066 -- add the dereference as a possible interpretation. Note that the
7067 -- indexing aspect may be a function that returns the element type
7068 -- with no intervening implicit dereference, and that the reference
7069 -- discriminant is not the first discriminant.
7071 if Has_Discriminants (Etype (Func)) then
7072 Disc := First_Discriminant (Etype (Func));
7073 while Present (Disc) loop
7074 declare
7075 Elmt_Type : Entity_Id;
7076 begin
7077 if Has_Implicit_Dereference (Disc) then
7078 Elmt_Type := Designated_Type (Etype (Disc));
7079 Add_One_Interp (Indexing, Disc, Elmt_Type);
7080 Add_One_Interp (N, Disc, Elmt_Type);
7081 exit;
7082 end if;
7083 end;
7085 Next_Discriminant (Disc);
7086 end loop;
7087 end if;
7089 else
7090 Indexing :=
7091 Make_Function_Call (Loc,
7092 Name => Make_Identifier (Loc, Chars (Func_Name)),
7093 Parameter_Associations => Assoc);
7095 Set_Parent (Indexing, Parent (N));
7096 Set_Generalized_Indexing (N, Indexing);
7098 declare
7099 I : Interp_Index;
7100 It : Interp;
7101 Success : Boolean;
7103 begin
7104 Get_First_Interp (Func_Name, I, It);
7105 Set_Etype (Indexing, Any_Type);
7106 while Present (It.Nam) loop
7107 Analyze_One_Call (Indexing, It.Nam, False, Success);
7109 if Success then
7110 Set_Etype (Name (Indexing), It.Typ);
7111 Set_Entity (Name (Indexing), It.Nam);
7112 Set_Etype (N, Etype (Indexing));
7114 -- Add implicit dereference interpretation
7116 if Has_Discriminants (Etype (It.Nam)) then
7117 Disc := First_Discriminant (Etype (It.Nam));
7118 while Present (Disc) loop
7119 if Has_Implicit_Dereference (Disc) then
7120 Add_One_Interp
7121 (Indexing, Disc, Designated_Type (Etype (Disc)));
7122 Add_One_Interp
7123 (N, Disc, Designated_Type (Etype (Disc)));
7124 exit;
7125 end if;
7127 Next_Discriminant (Disc);
7128 end loop;
7129 end if;
7131 exit;
7132 end if;
7134 Get_Next_Interp (I, It);
7135 end loop;
7136 end;
7137 end if;
7139 if Etype (Indexing) = Any_Type then
7140 Error_Msg_NE
7141 ("container cannot be indexed with&", N, Etype (First (Exprs)));
7142 Rewrite (N, New_Occurrence_Of (Any_Id, Loc));
7143 end if;
7145 return True;
7146 end Try_Container_Indexing;
7148 -----------------------
7149 -- Try_Indirect_Call --
7150 -----------------------
7152 function Try_Indirect_Call
7153 (N : Node_Id;
7154 Nam : Entity_Id;
7155 Typ : Entity_Id) return Boolean
7157 Actual : Node_Id;
7158 Formal : Entity_Id;
7160 Call_OK : Boolean;
7161 pragma Warnings (Off, Call_OK);
7163 begin
7164 Normalize_Actuals (N, Designated_Type (Typ), False, Call_OK);
7166 Actual := First_Actual (N);
7167 Formal := First_Formal (Designated_Type (Typ));
7168 while Present (Actual) and then Present (Formal) loop
7169 if not Has_Compatible_Type (Actual, Etype (Formal)) then
7170 return False;
7171 end if;
7173 Next (Actual);
7174 Next_Formal (Formal);
7175 end loop;
7177 if No (Actual) and then No (Formal) then
7178 Add_One_Interp (N, Nam, Etype (Designated_Type (Typ)));
7180 -- Nam is a candidate interpretation for the name in the call,
7181 -- if it is not an indirect call.
7183 if not Is_Type (Nam)
7184 and then Is_Entity_Name (Name (N))
7185 then
7186 Set_Entity (Name (N), Nam);
7187 end if;
7189 return True;
7191 else
7192 return False;
7193 end if;
7194 end Try_Indirect_Call;
7196 ----------------------
7197 -- Try_Indexed_Call --
7198 ----------------------
7200 function Try_Indexed_Call
7201 (N : Node_Id;
7202 Nam : Entity_Id;
7203 Typ : Entity_Id;
7204 Skip_First : Boolean) return Boolean
7206 Loc : constant Source_Ptr := Sloc (N);
7207 Actuals : constant List_Id := Parameter_Associations (N);
7208 Actual : Node_Id;
7209 Index : Entity_Id;
7211 begin
7212 Actual := First (Actuals);
7214 -- If the call was originally written in prefix form, skip the first
7215 -- actual, which is obviously not defaulted.
7217 if Skip_First then
7218 Next (Actual);
7219 end if;
7221 Index := First_Index (Typ);
7222 while Present (Actual) and then Present (Index) loop
7224 -- If the parameter list has a named association, the expression
7225 -- is definitely a call and not an indexed component.
7227 if Nkind (Actual) = N_Parameter_Association then
7228 return False;
7229 end if;
7231 if Is_Entity_Name (Actual)
7232 and then Is_Type (Entity (Actual))
7233 and then No (Next (Actual))
7234 then
7235 -- A single actual that is a type name indicates a slice if the
7236 -- type is discrete, and an error otherwise.
7238 if Is_Discrete_Type (Entity (Actual)) then
7239 Rewrite (N,
7240 Make_Slice (Loc,
7241 Prefix =>
7242 Make_Function_Call (Loc,
7243 Name => Relocate_Node (Name (N))),
7244 Discrete_Range =>
7245 New_Occurrence_Of (Entity (Actual), Sloc (Actual))));
7247 Analyze (N);
7249 else
7250 Error_Msg_N ("invalid use of type in expression", Actual);
7251 Set_Etype (N, Any_Type);
7252 end if;
7254 return True;
7256 elsif not Has_Compatible_Type (Actual, Etype (Index)) then
7257 return False;
7258 end if;
7260 Next (Actual);
7261 Next_Index (Index);
7262 end loop;
7264 if No (Actual) and then No (Index) then
7265 Add_One_Interp (N, Nam, Component_Type (Typ));
7267 -- Nam is a candidate interpretation for the name in the call,
7268 -- if it is not an indirect call.
7270 if not Is_Type (Nam)
7271 and then Is_Entity_Name (Name (N))
7272 then
7273 Set_Entity (Name (N), Nam);
7274 end if;
7276 return True;
7277 else
7278 return False;
7279 end if;
7280 end Try_Indexed_Call;
7282 --------------------------
7283 -- Try_Object_Operation --
7284 --------------------------
7286 function Try_Object_Operation
7287 (N : Node_Id; CW_Test_Only : Boolean := False) return Boolean
7289 K : constant Node_Kind := Nkind (Parent (N));
7290 Is_Subprg_Call : constant Boolean := K in N_Subprogram_Call;
7291 Loc : constant Source_Ptr := Sloc (N);
7292 Obj : constant Node_Id := Prefix (N);
7294 Subprog : constant Node_Id :=
7295 Make_Identifier (Sloc (Selector_Name (N)),
7296 Chars => Chars (Selector_Name (N)));
7297 -- Identifier on which possible interpretations will be collected
7299 Report_Error : Boolean := False;
7300 -- If no candidate interpretation matches the context, redo analysis
7301 -- with Report_Error True to provide additional information.
7303 Actual : Node_Id;
7304 Candidate : Entity_Id := Empty;
7305 New_Call_Node : Node_Id := Empty;
7306 Node_To_Replace : Node_Id;
7307 Obj_Type : Entity_Id := Etype (Obj);
7308 Success : Boolean := False;
7310 function Valid_Candidate
7311 (Success : Boolean;
7312 Call : Node_Id;
7313 Subp : Entity_Id) return Entity_Id;
7314 -- If the subprogram is a valid interpretation, record it, and add
7315 -- to the list of interpretations of Subprog. Otherwise return Empty.
7317 procedure Complete_Object_Operation
7318 (Call_Node : Node_Id;
7319 Node_To_Replace : Node_Id);
7320 -- Make Subprog the name of Call_Node, replace Node_To_Replace with
7321 -- Call_Node, insert the object (or its dereference) as the first actual
7322 -- in the call, and complete the analysis of the call.
7324 procedure Report_Ambiguity (Op : Entity_Id);
7325 -- If a prefixed procedure call is ambiguous, indicate whether the
7326 -- call includes an implicit dereference or an implicit 'Access.
7328 procedure Transform_Object_Operation
7329 (Call_Node : out Node_Id;
7330 Node_To_Replace : out Node_Id);
7331 -- Transform Obj.Operation (X, Y,,) into Operation (Obj, X, Y ..)
7332 -- Call_Node is the resulting subprogram call, Node_To_Replace is
7333 -- either N or the parent of N, and Subprog is a reference to the
7334 -- subprogram we are trying to match.
7336 function Try_Class_Wide_Operation
7337 (Call_Node : Node_Id;
7338 Node_To_Replace : Node_Id) return Boolean;
7339 -- Traverse all ancestor types looking for a class-wide subprogram
7340 -- for which the current operation is a valid non-dispatching call.
7342 procedure Try_One_Prefix_Interpretation (T : Entity_Id);
7343 -- If prefix is overloaded, its interpretation may include different
7344 -- tagged types, and we must examine the primitive operations and
7345 -- the class-wide operations of each in order to find candidate
7346 -- interpretations for the call as a whole.
7348 function Try_Primitive_Operation
7349 (Call_Node : Node_Id;
7350 Node_To_Replace : Node_Id) return Boolean;
7351 -- Traverse the list of primitive subprograms looking for a dispatching
7352 -- operation for which the current node is a valid call .
7354 ---------------------
7355 -- Valid_Candidate --
7356 ---------------------
7358 function Valid_Candidate
7359 (Success : Boolean;
7360 Call : Node_Id;
7361 Subp : Entity_Id) return Entity_Id
7363 Arr_Type : Entity_Id;
7364 Comp_Type : Entity_Id;
7366 begin
7367 -- If the subprogram is a valid interpretation, record it in global
7368 -- variable Subprog, to collect all possible overloadings.
7370 if Success then
7371 if Subp /= Entity (Subprog) then
7372 Add_One_Interp (Subprog, Subp, Etype (Subp));
7373 end if;
7374 end if;
7376 -- If the call may be an indexed call, retrieve component type of
7377 -- resulting expression, and add possible interpretation.
7379 Arr_Type := Empty;
7380 Comp_Type := Empty;
7382 if Nkind (Call) = N_Function_Call
7383 and then Nkind (Parent (N)) = N_Indexed_Component
7384 and then Needs_One_Actual (Subp)
7385 then
7386 if Is_Array_Type (Etype (Subp)) then
7387 Arr_Type := Etype (Subp);
7389 elsif Is_Access_Type (Etype (Subp))
7390 and then Is_Array_Type (Designated_Type (Etype (Subp)))
7391 then
7392 Arr_Type := Designated_Type (Etype (Subp));
7393 end if;
7394 end if;
7396 if Present (Arr_Type) then
7398 -- Verify that the actuals (excluding the object) match the types
7399 -- of the indexes.
7401 declare
7402 Actual : Node_Id;
7403 Index : Node_Id;
7405 begin
7406 Actual := Next (First_Actual (Call));
7407 Index := First_Index (Arr_Type);
7408 while Present (Actual) and then Present (Index) loop
7409 if not Has_Compatible_Type (Actual, Etype (Index)) then
7410 Arr_Type := Empty;
7411 exit;
7412 end if;
7414 Next_Actual (Actual);
7415 Next_Index (Index);
7416 end loop;
7418 if No (Actual)
7419 and then No (Index)
7420 and then Present (Arr_Type)
7421 then
7422 Comp_Type := Component_Type (Arr_Type);
7423 end if;
7424 end;
7426 if Present (Comp_Type)
7427 and then Etype (Subprog) /= Comp_Type
7428 then
7429 Add_One_Interp (Subprog, Subp, Comp_Type);
7430 end if;
7431 end if;
7433 if Etype (Call) /= Any_Type then
7434 return Subp;
7435 else
7436 return Empty;
7437 end if;
7438 end Valid_Candidate;
7440 -------------------------------
7441 -- Complete_Object_Operation --
7442 -------------------------------
7444 procedure Complete_Object_Operation
7445 (Call_Node : Node_Id;
7446 Node_To_Replace : Node_Id)
7448 Control : constant Entity_Id := First_Formal (Entity (Subprog));
7449 Formal_Type : constant Entity_Id := Etype (Control);
7450 First_Actual : Node_Id;
7452 begin
7453 -- Place the name of the operation, with its interpretations,
7454 -- on the rewritten call.
7456 Set_Name (Call_Node, Subprog);
7458 First_Actual := First (Parameter_Associations (Call_Node));
7460 -- For cross-reference purposes, treat the new node as being in the
7461 -- source if the original one is. Set entity and type, even though
7462 -- they may be overwritten during resolution if overloaded.
7464 Set_Comes_From_Source (Subprog, Comes_From_Source (N));
7465 Set_Comes_From_Source (Call_Node, Comes_From_Source (N));
7467 if Nkind (N) = N_Selected_Component
7468 and then not Inside_A_Generic
7469 then
7470 Set_Entity (Selector_Name (N), Entity (Subprog));
7471 Set_Etype (Selector_Name (N), Etype (Entity (Subprog)));
7472 end if;
7474 -- If need be, rewrite first actual as an explicit dereference. If
7475 -- the call is overloaded, the rewriting can only be done once the
7476 -- primitive operation is identified.
7478 if Is_Overloaded (Subprog) then
7480 -- The prefix itself may be overloaded, and its interpretations
7481 -- must be propagated to the new actual in the call.
7483 if Is_Overloaded (Obj) then
7484 Save_Interps (Obj, First_Actual);
7485 end if;
7487 Rewrite (First_Actual, Obj);
7489 elsif not Is_Access_Type (Formal_Type)
7490 and then Is_Access_Type (Etype (Obj))
7491 then
7492 Rewrite (First_Actual,
7493 Make_Explicit_Dereference (Sloc (Obj), Obj));
7494 Analyze (First_Actual);
7496 -- If we need to introduce an explicit dereference, verify that
7497 -- the resulting actual is compatible with the mode of the formal.
7499 if Ekind (First_Formal (Entity (Subprog))) /= E_In_Parameter
7500 and then Is_Access_Constant (Etype (Obj))
7501 then
7502 Error_Msg_NE
7503 ("expect variable in call to&", Prefix (N), Entity (Subprog));
7504 end if;
7506 -- Conversely, if the formal is an access parameter and the object
7507 -- is not, replace the actual with a 'Access reference. Its analysis
7508 -- will check that the object is aliased.
7510 elsif Is_Access_Type (Formal_Type)
7511 and then not Is_Access_Type (Etype (Obj))
7512 then
7513 -- A special case: A.all'access is illegal if A is an access to a
7514 -- constant and the context requires an access to a variable.
7516 if not Is_Access_Constant (Formal_Type) then
7517 if (Nkind (Obj) = N_Explicit_Dereference
7518 and then Is_Access_Constant (Etype (Prefix (Obj))))
7519 or else not Is_Variable (Obj)
7520 then
7521 Error_Msg_NE
7522 ("actual for& must be a variable", Obj, Control);
7523 end if;
7524 end if;
7526 Rewrite (First_Actual,
7527 Make_Attribute_Reference (Loc,
7528 Attribute_Name => Name_Access,
7529 Prefix => Relocate_Node (Obj)));
7531 if not Is_Aliased_View (Obj) then
7532 Error_Msg_NE
7533 ("object in prefixed call to& must be aliased"
7534 & " (RM-2005 4.3.1 (13))",
7535 Prefix (First_Actual), Subprog);
7536 end if;
7538 Analyze (First_Actual);
7540 else
7541 if Is_Overloaded (Obj) then
7542 Save_Interps (Obj, First_Actual);
7543 end if;
7545 Rewrite (First_Actual, Obj);
7546 end if;
7548 Rewrite (Node_To_Replace, Call_Node);
7550 -- Propagate the interpretations collected in subprog to the new
7551 -- function call node, to be resolved from context.
7553 if Is_Overloaded (Subprog) then
7554 Save_Interps (Subprog, Node_To_Replace);
7556 else
7557 Analyze (Node_To_Replace);
7559 -- If the operation has been rewritten into a call, which may get
7560 -- subsequently an explicit dereference, preserve the type on the
7561 -- original node (selected component or indexed component) for
7562 -- subsequent legality tests, e.g. Is_Variable. which examines
7563 -- the original node.
7565 if Nkind (Node_To_Replace) = N_Function_Call then
7566 Set_Etype
7567 (Original_Node (Node_To_Replace), Etype (Node_To_Replace));
7568 end if;
7569 end if;
7570 end Complete_Object_Operation;
7572 ----------------------
7573 -- Report_Ambiguity --
7574 ----------------------
7576 procedure Report_Ambiguity (Op : Entity_Id) is
7577 Access_Actual : constant Boolean :=
7578 Is_Access_Type (Etype (Prefix (N)));
7579 Access_Formal : Boolean := False;
7581 begin
7582 Error_Msg_Sloc := Sloc (Op);
7584 if Present (First_Formal (Op)) then
7585 Access_Formal := Is_Access_Type (Etype (First_Formal (Op)));
7586 end if;
7588 if Access_Formal and then not Access_Actual then
7589 if Nkind (Parent (Op)) = N_Full_Type_Declaration then
7590 Error_Msg_N
7591 ("\possible interpretation "
7592 & "(inherited, with implicit 'Access) #", N);
7593 else
7594 Error_Msg_N
7595 ("\possible interpretation (with implicit 'Access) #", N);
7596 end if;
7598 elsif not Access_Formal and then Access_Actual then
7599 if Nkind (Parent (Op)) = N_Full_Type_Declaration then
7600 Error_Msg_N
7601 ("\possible interpretation "
7602 & "( inherited, with implicit dereference) #", N);
7603 else
7604 Error_Msg_N
7605 ("\possible interpretation (with implicit dereference) #", N);
7606 end if;
7608 else
7609 if Nkind (Parent (Op)) = N_Full_Type_Declaration then
7610 Error_Msg_N ("\possible interpretation (inherited)#", N);
7611 else
7612 Error_Msg_N -- CODEFIX
7613 ("\possible interpretation#", N);
7614 end if;
7615 end if;
7616 end Report_Ambiguity;
7618 --------------------------------
7619 -- Transform_Object_Operation --
7620 --------------------------------
7622 procedure Transform_Object_Operation
7623 (Call_Node : out Node_Id;
7624 Node_To_Replace : out Node_Id)
7626 Dummy : constant Node_Id := New_Copy (Obj);
7627 -- Placeholder used as a first parameter in the call, replaced
7628 -- eventually by the proper object.
7630 Parent_Node : constant Node_Id := Parent (N);
7632 Actual : Node_Id;
7633 Actuals : List_Id;
7635 begin
7636 -- Common case covering 1) Call to a procedure and 2) Call to a
7637 -- function that has some additional actuals.
7639 if Nkind (Parent_Node) in N_Subprogram_Call
7641 -- N is a selected component node containing the name of the
7642 -- subprogram. If N is not the name of the parent node we must
7643 -- not replace the parent node by the new construct. This case
7644 -- occurs when N is a parameterless call to a subprogram that
7645 -- is an actual parameter of a call to another subprogram. For
7646 -- example:
7647 -- Some_Subprogram (..., Obj.Operation, ...)
7649 and then Name (Parent_Node) = N
7650 then
7651 Node_To_Replace := Parent_Node;
7653 Actuals := Parameter_Associations (Parent_Node);
7655 if Present (Actuals) then
7656 Prepend (Dummy, Actuals);
7657 else
7658 Actuals := New_List (Dummy);
7659 end if;
7661 if Nkind (Parent_Node) = N_Procedure_Call_Statement then
7662 Call_Node :=
7663 Make_Procedure_Call_Statement (Loc,
7664 Name => New_Copy (Subprog),
7665 Parameter_Associations => Actuals);
7667 else
7668 Call_Node :=
7669 Make_Function_Call (Loc,
7670 Name => New_Copy (Subprog),
7671 Parameter_Associations => Actuals);
7672 end if;
7674 -- Before analysis, a function call appears as an indexed component
7675 -- if there are no named associations.
7677 elsif Nkind (Parent_Node) = N_Indexed_Component
7678 and then N = Prefix (Parent_Node)
7679 then
7680 Node_To_Replace := Parent_Node;
7681 Actuals := Expressions (Parent_Node);
7683 Actual := First (Actuals);
7684 while Present (Actual) loop
7685 Analyze (Actual);
7686 Next (Actual);
7687 end loop;
7689 Prepend (Dummy, Actuals);
7691 Call_Node :=
7692 Make_Function_Call (Loc,
7693 Name => New_Copy (Subprog),
7694 Parameter_Associations => Actuals);
7696 -- Parameterless call: Obj.F is rewritten as F (Obj)
7698 else
7699 Node_To_Replace := N;
7701 Call_Node :=
7702 Make_Function_Call (Loc,
7703 Name => New_Copy (Subprog),
7704 Parameter_Associations => New_List (Dummy));
7705 end if;
7706 end Transform_Object_Operation;
7708 ------------------------------
7709 -- Try_Class_Wide_Operation --
7710 ------------------------------
7712 function Try_Class_Wide_Operation
7713 (Call_Node : Node_Id;
7714 Node_To_Replace : Node_Id) return Boolean
7716 Anc_Type : Entity_Id;
7717 Matching_Op : Entity_Id := Empty;
7718 Error : Boolean;
7720 procedure Traverse_Homonyms
7721 (Anc_Type : Entity_Id;
7722 Error : out Boolean);
7723 -- Traverse the homonym chain of the subprogram searching for those
7724 -- homonyms whose first formal has the Anc_Type's class-wide type,
7725 -- or an anonymous access type designating the class-wide type. If
7726 -- an ambiguity is detected, then Error is set to True.
7728 procedure Traverse_Interfaces
7729 (Anc_Type : Entity_Id;
7730 Error : out Boolean);
7731 -- Traverse the list of interfaces, if any, associated with Anc_Type
7732 -- and search for acceptable class-wide homonyms associated with each
7733 -- interface. If an ambiguity is detected, then Error is set to True.
7735 -----------------------
7736 -- Traverse_Homonyms --
7737 -----------------------
7739 procedure Traverse_Homonyms
7740 (Anc_Type : Entity_Id;
7741 Error : out Boolean)
7743 Cls_Type : Entity_Id;
7744 Hom : Entity_Id;
7745 Hom_Ref : Node_Id;
7746 Success : Boolean;
7748 begin
7749 Error := False;
7751 Cls_Type := Class_Wide_Type (Anc_Type);
7753 Hom := Current_Entity (Subprog);
7755 -- Find a non-hidden operation whose first parameter is of the
7756 -- class-wide type, a subtype thereof, or an anonymous access
7757 -- to same. If in an instance, the operation can be considered
7758 -- even if hidden (it may be hidden because the instantiation
7759 -- is expanded after the containing package has been analyzed).
7761 while Present (Hom) loop
7762 if Ekind_In (Hom, E_Procedure, E_Function)
7763 and then (not Is_Hidden (Hom) or else In_Instance)
7764 and then Scope (Hom) = Scope (Anc_Type)
7765 and then Present (First_Formal (Hom))
7766 and then
7767 (Base_Type (Etype (First_Formal (Hom))) = Cls_Type
7768 or else
7769 (Is_Access_Type (Etype (First_Formal (Hom)))
7770 and then
7771 Ekind (Etype (First_Formal (Hom))) =
7772 E_Anonymous_Access_Type
7773 and then
7774 Base_Type
7775 (Designated_Type (Etype (First_Formal (Hom)))) =
7776 Cls_Type))
7777 then
7778 -- If the context is a procedure call, ignore functions
7779 -- in the name of the call.
7781 if Ekind (Hom) = E_Function
7782 and then Nkind (Parent (N)) = N_Procedure_Call_Statement
7783 and then N = Name (Parent (N))
7784 then
7785 goto Next_Hom;
7787 -- If the context is a function call, ignore procedures
7788 -- in the name of the call.
7790 elsif Ekind (Hom) = E_Procedure
7791 and then Nkind (Parent (N)) /= N_Procedure_Call_Statement
7792 then
7793 goto Next_Hom;
7794 end if;
7796 Set_Etype (Call_Node, Any_Type);
7797 Set_Is_Overloaded (Call_Node, False);
7798 Success := False;
7800 if No (Matching_Op) then
7801 Hom_Ref := New_Occurrence_Of (Hom, Sloc (Subprog));
7802 Set_Etype (Call_Node, Any_Type);
7803 Set_Parent (Call_Node, Parent (Node_To_Replace));
7805 Set_Name (Call_Node, Hom_Ref);
7807 Analyze_One_Call
7808 (N => Call_Node,
7809 Nam => Hom,
7810 Report => Report_Error,
7811 Success => Success,
7812 Skip_First => True);
7814 Matching_Op :=
7815 Valid_Candidate (Success, Call_Node, Hom);
7817 else
7818 Analyze_One_Call
7819 (N => Call_Node,
7820 Nam => Hom,
7821 Report => Report_Error,
7822 Success => Success,
7823 Skip_First => True);
7825 if Present (Valid_Candidate (Success, Call_Node, Hom))
7826 and then Nkind (Call_Node) /= N_Function_Call
7827 then
7828 Error_Msg_NE ("ambiguous call to&", N, Hom);
7829 Report_Ambiguity (Matching_Op);
7830 Report_Ambiguity (Hom);
7831 Error := True;
7832 return;
7833 end if;
7834 end if;
7835 end if;
7837 <<Next_Hom>>
7838 Hom := Homonym (Hom);
7839 end loop;
7840 end Traverse_Homonyms;
7842 -------------------------
7843 -- Traverse_Interfaces --
7844 -------------------------
7846 procedure Traverse_Interfaces
7847 (Anc_Type : Entity_Id;
7848 Error : out Boolean)
7850 Intface_List : constant List_Id :=
7851 Abstract_Interface_List (Anc_Type);
7852 Intface : Node_Id;
7854 begin
7855 Error := False;
7857 if Is_Non_Empty_List (Intface_List) then
7858 Intface := First (Intface_List);
7859 while Present (Intface) loop
7861 -- Look for acceptable class-wide homonyms associated with
7862 -- the interface.
7864 Traverse_Homonyms (Etype (Intface), Error);
7866 if Error then
7867 return;
7868 end if;
7870 -- Continue the search by looking at each of the interface's
7871 -- associated interface ancestors.
7873 Traverse_Interfaces (Etype (Intface), Error);
7875 if Error then
7876 return;
7877 end if;
7879 Next (Intface);
7880 end loop;
7881 end if;
7882 end Traverse_Interfaces;
7884 -- Start of processing for Try_Class_Wide_Operation
7886 begin
7887 -- If we are searching only for conflicting class-wide subprograms
7888 -- then initialize directly Matching_Op with the target entity.
7890 if CW_Test_Only then
7891 Matching_Op := Entity (Selector_Name (N));
7892 end if;
7894 -- Loop through ancestor types (including interfaces), traversing
7895 -- the homonym chain of the subprogram, trying out those homonyms
7896 -- whose first formal has the class-wide type of the ancestor, or
7897 -- an anonymous access type designating the class-wide type.
7899 Anc_Type := Obj_Type;
7900 loop
7901 -- Look for a match among homonyms associated with the ancestor
7903 Traverse_Homonyms (Anc_Type, Error);
7905 if Error then
7906 return True;
7907 end if;
7909 -- Continue the search for matches among homonyms associated with
7910 -- any interfaces implemented by the ancestor.
7912 Traverse_Interfaces (Anc_Type, Error);
7914 if Error then
7915 return True;
7916 end if;
7918 exit when Etype (Anc_Type) = Anc_Type;
7919 Anc_Type := Etype (Anc_Type);
7920 end loop;
7922 if Present (Matching_Op) then
7923 Set_Etype (Call_Node, Etype (Matching_Op));
7924 end if;
7926 return Present (Matching_Op);
7927 end Try_Class_Wide_Operation;
7929 -----------------------------------
7930 -- Try_One_Prefix_Interpretation --
7931 -----------------------------------
7933 procedure Try_One_Prefix_Interpretation (T : Entity_Id) is
7934 begin
7935 Obj_Type := T;
7937 if Is_Access_Type (Obj_Type) then
7938 Obj_Type := Designated_Type (Obj_Type);
7939 end if;
7941 if Ekind (Obj_Type) = E_Private_Subtype then
7942 Obj_Type := Base_Type (Obj_Type);
7943 end if;
7945 if Is_Class_Wide_Type (Obj_Type) then
7946 Obj_Type := Etype (Class_Wide_Type (Obj_Type));
7947 end if;
7949 -- The type may have be obtained through a limited_with clause,
7950 -- in which case the primitive operations are available on its
7951 -- non-limited view. If still incomplete, retrieve full view.
7953 if Ekind (Obj_Type) = E_Incomplete_Type
7954 and then From_Limited_With (Obj_Type)
7955 then
7956 Obj_Type := Get_Full_View (Non_Limited_View (Obj_Type));
7957 end if;
7959 -- If the object is not tagged, or the type is still an incomplete
7960 -- type, this is not a prefixed call.
7962 if not Is_Tagged_Type (Obj_Type)
7963 or else Is_Incomplete_Type (Obj_Type)
7964 then
7965 return;
7966 end if;
7968 declare
7969 Dup_Call_Node : constant Node_Id := New_Copy (New_Call_Node);
7970 CW_Result : Boolean;
7971 Prim_Result : Boolean;
7972 pragma Unreferenced (CW_Result);
7974 begin
7975 if not CW_Test_Only then
7976 Prim_Result :=
7977 Try_Primitive_Operation
7978 (Call_Node => New_Call_Node,
7979 Node_To_Replace => Node_To_Replace);
7980 end if;
7982 -- Check if there is a class-wide subprogram covering the
7983 -- primitive. This check must be done even if a candidate
7984 -- was found in order to report ambiguous calls.
7986 if not (Prim_Result) then
7987 CW_Result :=
7988 Try_Class_Wide_Operation
7989 (Call_Node => New_Call_Node,
7990 Node_To_Replace => Node_To_Replace);
7992 -- If we found a primitive we search for class-wide subprograms
7993 -- using a duplicate of the call node (done to avoid missing its
7994 -- decoration if there is no ambiguity).
7996 else
7997 CW_Result :=
7998 Try_Class_Wide_Operation
7999 (Call_Node => Dup_Call_Node,
8000 Node_To_Replace => Node_To_Replace);
8001 end if;
8002 end;
8003 end Try_One_Prefix_Interpretation;
8005 -----------------------------
8006 -- Try_Primitive_Operation --
8007 -----------------------------
8009 function Try_Primitive_Operation
8010 (Call_Node : Node_Id;
8011 Node_To_Replace : Node_Id) return Boolean
8013 Elmt : Elmt_Id;
8014 Prim_Op : Entity_Id;
8015 Matching_Op : Entity_Id := Empty;
8016 Prim_Op_Ref : Node_Id := Empty;
8018 Corr_Type : Entity_Id := Empty;
8019 -- If the prefix is a synchronized type, the controlling type of
8020 -- the primitive operation is the corresponding record type, else
8021 -- this is the object type itself.
8023 Success : Boolean := False;
8025 function Collect_Generic_Type_Ops (T : Entity_Id) return Elist_Id;
8026 -- For tagged types the candidate interpretations are found in
8027 -- the list of primitive operations of the type and its ancestors.
8028 -- For formal tagged types we have to find the operations declared
8029 -- in the same scope as the type (including in the generic formal
8030 -- part) because the type itself carries no primitive operations,
8031 -- except for formal derived types that inherit the operations of
8032 -- the parent and progenitors.
8034 -- If the context is a generic subprogram body, the generic formals
8035 -- are visible by name, but are not in the entity list of the
8036 -- subprogram because that list starts with the subprogram formals.
8037 -- We retrieve the candidate operations from the generic declaration.
8039 function Is_Private_Overriding (Op : Entity_Id) return Boolean;
8040 -- An operation that overrides an inherited operation in the private
8041 -- part of its package may be hidden, but if the inherited operation
8042 -- is visible a direct call to it will dispatch to the private one,
8043 -- which is therefore a valid candidate.
8045 function Valid_First_Argument_Of (Op : Entity_Id) return Boolean;
8046 -- Verify that the prefix, dereferenced if need be, is a valid
8047 -- controlling argument in a call to Op. The remaining actuals
8048 -- are checked in the subsequent call to Analyze_One_Call.
8050 ------------------------------
8051 -- Collect_Generic_Type_Ops --
8052 ------------------------------
8054 function Collect_Generic_Type_Ops (T : Entity_Id) return Elist_Id is
8055 Bas : constant Entity_Id := Base_Type (T);
8056 Candidates : constant Elist_Id := New_Elmt_List;
8057 Subp : Entity_Id;
8058 Formal : Entity_Id;
8060 procedure Check_Candidate;
8061 -- The operation is a candidate if its first parameter is a
8062 -- controlling operand of the desired type.
8064 -----------------------
8065 -- Check_Candidate; --
8066 -----------------------
8068 procedure Check_Candidate is
8069 begin
8070 Formal := First_Formal (Subp);
8072 if Present (Formal)
8073 and then Is_Controlling_Formal (Formal)
8074 and then
8075 (Base_Type (Etype (Formal)) = Bas
8076 or else
8077 (Is_Access_Type (Etype (Formal))
8078 and then Designated_Type (Etype (Formal)) = Bas))
8079 then
8080 Append_Elmt (Subp, Candidates);
8081 end if;
8082 end Check_Candidate;
8084 -- Start of processing for Collect_Generic_Type_Ops
8086 begin
8087 if Is_Derived_Type (T) then
8088 return Primitive_Operations (T);
8090 elsif Ekind_In (Scope (T), E_Procedure, E_Function) then
8092 -- Scan the list of generic formals to find subprograms
8093 -- that may have a first controlling formal of the type.
8095 if Nkind (Unit_Declaration_Node (Scope (T))) =
8096 N_Generic_Subprogram_Declaration
8097 then
8098 declare
8099 Decl : Node_Id;
8101 begin
8102 Decl :=
8103 First (Generic_Formal_Declarations
8104 (Unit_Declaration_Node (Scope (T))));
8105 while Present (Decl) loop
8106 if Nkind (Decl) in N_Formal_Subprogram_Declaration then
8107 Subp := Defining_Entity (Decl);
8108 Check_Candidate;
8109 end if;
8111 Next (Decl);
8112 end loop;
8113 end;
8114 end if;
8115 return Candidates;
8117 else
8118 -- Scan the list of entities declared in the same scope as
8119 -- the type. In general this will be an open scope, given that
8120 -- the call we are analyzing can only appear within a generic
8121 -- declaration or body (either the one that declares T, or a
8122 -- child unit).
8124 -- For a subtype representing a generic actual type, go to the
8125 -- base type.
8127 if Is_Generic_Actual_Type (T) then
8128 Subp := First_Entity (Scope (Base_Type (T)));
8129 else
8130 Subp := First_Entity (Scope (T));
8131 end if;
8133 while Present (Subp) loop
8134 if Is_Overloadable (Subp) then
8135 Check_Candidate;
8136 end if;
8138 Next_Entity (Subp);
8139 end loop;
8141 return Candidates;
8142 end if;
8143 end Collect_Generic_Type_Ops;
8145 ---------------------------
8146 -- Is_Private_Overriding --
8147 ---------------------------
8149 function Is_Private_Overriding (Op : Entity_Id) return Boolean is
8150 Visible_Op : constant Entity_Id := Homonym (Op);
8152 begin
8153 return Present (Visible_Op)
8154 and then Scope (Op) = Scope (Visible_Op)
8155 and then not Comes_From_Source (Visible_Op)
8156 and then Alias (Visible_Op) = Op
8157 and then not Is_Hidden (Visible_Op);
8158 end Is_Private_Overriding;
8160 -----------------------------
8161 -- Valid_First_Argument_Of --
8162 -----------------------------
8164 function Valid_First_Argument_Of (Op : Entity_Id) return Boolean is
8165 Typ : Entity_Id := Etype (First_Formal (Op));
8167 begin
8168 if Is_Concurrent_Type (Typ)
8169 and then Present (Corresponding_Record_Type (Typ))
8170 then
8171 Typ := Corresponding_Record_Type (Typ);
8172 end if;
8174 -- Simple case. Object may be a subtype of the tagged type or
8175 -- may be the corresponding record of a synchronized type.
8177 return Obj_Type = Typ
8178 or else Base_Type (Obj_Type) = Typ
8179 or else Corr_Type = Typ
8181 -- Prefix can be dereferenced
8183 or else
8184 (Is_Access_Type (Corr_Type)
8185 and then Designated_Type (Corr_Type) = Typ)
8187 -- Formal is an access parameter, for which the object
8188 -- can provide an access.
8190 or else
8191 (Ekind (Typ) = E_Anonymous_Access_Type
8192 and then
8193 Base_Type (Designated_Type (Typ)) = Base_Type (Corr_Type));
8194 end Valid_First_Argument_Of;
8196 -- Start of processing for Try_Primitive_Operation
8198 begin
8199 -- Look for subprograms in the list of primitive operations. The name
8200 -- must be identical, and the kind of call indicates the expected
8201 -- kind of operation (function or procedure). If the type is a
8202 -- (tagged) synchronized type, the primitive ops are attached to the
8203 -- corresponding record (base) type.
8205 if Is_Concurrent_Type (Obj_Type) then
8206 if Present (Corresponding_Record_Type (Obj_Type)) then
8207 Corr_Type := Base_Type (Corresponding_Record_Type (Obj_Type));
8208 Elmt := First_Elmt (Primitive_Operations (Corr_Type));
8209 else
8210 Corr_Type := Obj_Type;
8211 Elmt := First_Elmt (Collect_Generic_Type_Ops (Obj_Type));
8212 end if;
8214 elsif not Is_Generic_Type (Obj_Type) then
8215 Corr_Type := Obj_Type;
8216 Elmt := First_Elmt (Primitive_Operations (Obj_Type));
8218 else
8219 Corr_Type := Obj_Type;
8220 Elmt := First_Elmt (Collect_Generic_Type_Ops (Obj_Type));
8221 end if;
8223 while Present (Elmt) loop
8224 Prim_Op := Node (Elmt);
8226 if Chars (Prim_Op) = Chars (Subprog)
8227 and then Present (First_Formal (Prim_Op))
8228 and then Valid_First_Argument_Of (Prim_Op)
8229 and then
8230 (Nkind (Call_Node) = N_Function_Call)
8232 (Ekind (Prim_Op) = E_Function)
8233 then
8234 -- Ada 2005 (AI-251): If this primitive operation corresponds
8235 -- to an immediate ancestor interface there is no need to add
8236 -- it to the list of interpretations; the corresponding aliased
8237 -- primitive is also in this list of primitive operations and
8238 -- will be used instead.
8240 if (Present (Interface_Alias (Prim_Op))
8241 and then Is_Ancestor (Find_Dispatching_Type
8242 (Alias (Prim_Op)), Corr_Type))
8244 -- Do not consider hidden primitives unless the type is in an
8245 -- open scope or we are within an instance, where visibility
8246 -- is known to be correct, or else if this is an overriding
8247 -- operation in the private part for an inherited operation.
8249 or else (Is_Hidden (Prim_Op)
8250 and then not Is_Immediately_Visible (Obj_Type)
8251 and then not In_Instance
8252 and then not Is_Private_Overriding (Prim_Op))
8253 then
8254 goto Continue;
8255 end if;
8257 Set_Etype (Call_Node, Any_Type);
8258 Set_Is_Overloaded (Call_Node, False);
8260 if No (Matching_Op) then
8261 Prim_Op_Ref := New_Occurrence_Of (Prim_Op, Sloc (Subprog));
8262 Candidate := Prim_Op;
8264 Set_Parent (Call_Node, Parent (Node_To_Replace));
8266 Set_Name (Call_Node, Prim_Op_Ref);
8267 Success := False;
8269 Analyze_One_Call
8270 (N => Call_Node,
8271 Nam => Prim_Op,
8272 Report => Report_Error,
8273 Success => Success,
8274 Skip_First => True);
8276 Matching_Op := Valid_Candidate (Success, Call_Node, Prim_Op);
8278 -- More than one interpretation, collect for subsequent
8279 -- disambiguation. If this is a procedure call and there
8280 -- is another match, report ambiguity now.
8282 else
8283 Analyze_One_Call
8284 (N => Call_Node,
8285 Nam => Prim_Op,
8286 Report => Report_Error,
8287 Success => Success,
8288 Skip_First => True);
8290 if Present (Valid_Candidate (Success, Call_Node, Prim_Op))
8291 and then Nkind (Call_Node) /= N_Function_Call
8292 then
8293 Error_Msg_NE ("ambiguous call to&", N, Prim_Op);
8294 Report_Ambiguity (Matching_Op);
8295 Report_Ambiguity (Prim_Op);
8296 return True;
8297 end if;
8298 end if;
8299 end if;
8301 <<Continue>>
8302 Next_Elmt (Elmt);
8303 end loop;
8305 if Present (Matching_Op) then
8306 Set_Etype (Call_Node, Etype (Matching_Op));
8307 end if;
8309 return Present (Matching_Op);
8310 end Try_Primitive_Operation;
8312 -- Start of processing for Try_Object_Operation
8314 begin
8315 Analyze_Expression (Obj);
8317 -- Analyze the actuals if node is known to be a subprogram call
8319 if Is_Subprg_Call and then N = Name (Parent (N)) then
8320 Actual := First (Parameter_Associations (Parent (N)));
8321 while Present (Actual) loop
8322 Analyze_Expression (Actual);
8323 Next (Actual);
8324 end loop;
8325 end if;
8327 -- Build a subprogram call node, using a copy of Obj as its first
8328 -- actual. This is a placeholder, to be replaced by an explicit
8329 -- dereference when needed.
8331 Transform_Object_Operation
8332 (Call_Node => New_Call_Node,
8333 Node_To_Replace => Node_To_Replace);
8335 Set_Etype (New_Call_Node, Any_Type);
8336 Set_Etype (Subprog, Any_Type);
8337 Set_Parent (New_Call_Node, Parent (Node_To_Replace));
8339 if not Is_Overloaded (Obj) then
8340 Try_One_Prefix_Interpretation (Obj_Type);
8342 else
8343 declare
8344 I : Interp_Index;
8345 It : Interp;
8346 begin
8347 Get_First_Interp (Obj, I, It);
8348 while Present (It.Nam) loop
8349 Try_One_Prefix_Interpretation (It.Typ);
8350 Get_Next_Interp (I, It);
8351 end loop;
8352 end;
8353 end if;
8355 if Etype (New_Call_Node) /= Any_Type then
8357 -- No need to complete the tree transformations if we are only
8358 -- searching for conflicting class-wide subprograms
8360 if CW_Test_Only then
8361 return False;
8362 else
8363 Complete_Object_Operation
8364 (Call_Node => New_Call_Node,
8365 Node_To_Replace => Node_To_Replace);
8366 return True;
8367 end if;
8369 elsif Present (Candidate) then
8371 -- The argument list is not type correct. Re-analyze with error
8372 -- reporting enabled, and use one of the possible candidates.
8373 -- In All_Errors_Mode, re-analyze all failed interpretations.
8375 if All_Errors_Mode then
8376 Report_Error := True;
8377 if Try_Primitive_Operation
8378 (Call_Node => New_Call_Node,
8379 Node_To_Replace => Node_To_Replace)
8381 or else
8382 Try_Class_Wide_Operation
8383 (Call_Node => New_Call_Node,
8384 Node_To_Replace => Node_To_Replace)
8385 then
8386 null;
8387 end if;
8389 else
8390 Analyze_One_Call
8391 (N => New_Call_Node,
8392 Nam => Candidate,
8393 Report => True,
8394 Success => Success,
8395 Skip_First => True);
8396 end if;
8398 -- No need for further errors
8400 return True;
8402 else
8403 -- There was no candidate operation, so report it as an error
8404 -- in the caller: Analyze_Selected_Component.
8406 return False;
8407 end if;
8408 end Try_Object_Operation;
8410 ---------
8411 -- wpo --
8412 ---------
8414 procedure wpo (T : Entity_Id) is
8415 Op : Entity_Id;
8416 E : Elmt_Id;
8418 begin
8419 if not Is_Tagged_Type (T) then
8420 return;
8421 end if;
8423 E := First_Elmt (Primitive_Operations (Base_Type (T)));
8424 while Present (E) loop
8425 Op := Node (E);
8426 Write_Int (Int (Op));
8427 Write_Str (" === ");
8428 Write_Name (Chars (Op));
8429 Write_Str (" in ");
8430 Write_Name (Chars (Scope (Op)));
8431 Next_Elmt (E);
8432 Write_Eol;
8433 end loop;
8434 end wpo;
8436 end Sem_Ch4;