1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2011, Free Software Foundation, Inc. --
11 -- GNAT is free software; you can redistribute it and/or modify it under --
12 -- terms of the GNU General Public License as published by the Free Soft- --
13 -- ware Foundation; either version 3, or (at your option) any later ver- --
14 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
15 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
16 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
17 -- for more details. You should have received a copy of the GNU General --
18 -- Public License distributed with GNAT; see file COPYING3. If not, go to --
19 -- http://www.gnu.org/licenses for a complete copy of the license. --
21 -- GNAT was originally developed by the GNAT team at New York University. --
22 -- Extensive contributions were provided by Ada Core Technologies Inc. --
24 ------------------------------------------------------------------------------
26 with Atree; use Atree;
27 with Debug; use Debug;
28 with Einfo; use Einfo;
29 with Elists; use Elists;
30 with Errout; use Errout;
31 with Exp_Util; use Exp_Util;
32 with Fname; use Fname;
33 with Itypes; use Itypes;
35 with Lib.Xref; use Lib.Xref;
36 with Namet; use Namet;
37 with Namet.Sp; use Namet.Sp;
38 with Nlists; use Nlists;
39 with Nmake; use Nmake;
41 with Output; use Output;
42 with Restrict; use Restrict;
43 with Rident; use Rident;
45 with Sem_Aux; use Sem_Aux;
46 with Sem_Case; use Sem_Case;
47 with Sem_Cat; use Sem_Cat;
48 with Sem_Ch3; use Sem_Ch3;
49 with Sem_Ch5; use Sem_Ch5;
50 with Sem_Ch6; use Sem_Ch6;
51 with Sem_Ch8; use Sem_Ch8;
52 with Sem_Disp; use Sem_Disp;
53 with Sem_Dist; use Sem_Dist;
54 with Sem_Eval; use Sem_Eval;
55 with Sem_Res; use Sem_Res;
56 with Sem_Type; use Sem_Type;
57 with Sem_Util; use Sem_Util;
58 with Sem_Warn; use Sem_Warn;
59 with Stand; use Stand;
60 with Sinfo; use Sinfo;
61 with Snames; use Snames;
62 with Tbuild; use Tbuild;
64 package body Sem_Ch4 is
66 -----------------------
67 -- Local Subprograms --
68 -----------------------
70 procedure Analyze_Concatenation_Rest (N : Node_Id);
71 -- Does the "rest" of the work of Analyze_Concatenation, after the left
72 -- operand has been analyzed. See Analyze_Concatenation for details.
74 procedure Analyze_Expression (N : Node_Id);
75 -- For expressions that are not names, this is just a call to analyze.
76 -- If the expression is a name, it may be a call to a parameterless
77 -- function, and if so must be converted into an explicit call node
78 -- and analyzed as such. This deproceduring must be done during the first
79 -- pass of overload resolution, because otherwise a procedure call with
80 -- overloaded actuals may fail to resolve.
82 procedure Analyze_Operator_Call (N : Node_Id; Op_Id : Entity_Id);
83 -- Analyze a call of the form "+"(x, y), etc. The prefix of the call
84 -- is an operator name or an expanded name whose selector is an operator
85 -- name, and one possible interpretation is as a predefined operator.
87 procedure Analyze_Overloaded_Selected_Component (N : Node_Id);
88 -- If the prefix of a selected_component is overloaded, the proper
89 -- interpretation that yields a record type with the proper selector
90 -- name must be selected.
92 procedure Analyze_User_Defined_Binary_Op (N : Node_Id; Op_Id : Entity_Id);
93 -- Procedure to analyze a user defined binary operator, which is resolved
94 -- like a function, but instead of a list of actuals it is presented
95 -- with the left and right operands of an operator node.
97 procedure Analyze_User_Defined_Unary_Op (N : Node_Id; Op_Id : Entity_Id);
98 -- Procedure to analyze a user defined unary operator, which is resolved
99 -- like a function, but instead of a list of actuals, it is presented with
100 -- the operand of the operator node.
102 procedure Ambiguous_Operands (N : Node_Id);
103 -- For equality, membership, and comparison operators with overloaded
104 -- arguments, list possible interpretations.
106 procedure Analyze_One_Call
110 Success : out Boolean;
111 Skip_First : Boolean := False);
112 -- Check one interpretation of an overloaded subprogram name for
113 -- compatibility with the types of the actuals in a call. If there is a
114 -- single interpretation which does not match, post error if Report is
117 -- Nam is the entity that provides the formals against which the actuals
118 -- are checked. Nam is either the name of a subprogram, or the internal
119 -- subprogram type constructed for an access_to_subprogram. If the actuals
120 -- are compatible with Nam, then Nam is added to the list of candidate
121 -- interpretations for N, and Success is set to True.
123 -- The flag Skip_First is used when analyzing a call that was rewritten
124 -- from object notation. In this case the first actual may have to receive
125 -- an explicit dereference, depending on the first formal of the operation
126 -- being called. The caller will have verified that the object is legal
127 -- for the call. If the remaining parameters match, the first parameter
128 -- will rewritten as a dereference if needed, prior to completing analysis.
130 procedure Check_Misspelled_Selector
133 -- Give possible misspelling diagnostic if Sel is likely to be a mis-
134 -- spelling of one of the selectors of the Prefix. This is called by
135 -- Analyze_Selected_Component after producing an invalid selector error
138 function Defined_In_Scope (T : Entity_Id; S : Entity_Id) return Boolean;
139 -- Verify that type T is declared in scope S. Used to find interpretations
140 -- for operators given by expanded names. This is abstracted as a separate
141 -- function to handle extensions to System, where S is System, but T is
142 -- declared in the extension.
144 procedure Find_Arithmetic_Types
148 -- L and R are the operands of an arithmetic operator. Find
149 -- consistent pairs of interpretations for L and R that have a
150 -- numeric type consistent with the semantics of the operator.
152 procedure Find_Comparison_Types
156 -- L and R are operands of a comparison operator. Find consistent
157 -- pairs of interpretations for L and R.
159 procedure Find_Concatenation_Types
163 -- For the four varieties of concatenation
165 procedure Find_Equality_Types
169 -- Ditto for equality operators
171 procedure Find_Boolean_Types
175 -- Ditto for binary logical operations
177 procedure Find_Negation_Types
181 -- Find consistent interpretation for operand of negation operator
183 procedure Find_Non_Universal_Interpretations
188 -- For equality and comparison operators, the result is always boolean,
189 -- and the legality of the operation is determined from the visibility
190 -- of the operand types. If one of the operands has a universal interpre-
191 -- tation, the legality check uses some compatible non-universal
192 -- interpretation of the other operand. N can be an operator node, or
193 -- a function call whose name is an operator designator.
195 function Find_Primitive_Operation (N : Node_Id) return Boolean;
196 -- Find candidate interpretations for the name Obj.Proc when it appears
197 -- in a subprogram renaming declaration.
199 procedure Find_Unary_Types
203 -- Unary arithmetic types: plus, minus, abs
205 procedure Check_Arithmetic_Pair
209 -- Subsidiary procedure to Find_Arithmetic_Types. T1 and T2 are valid
210 -- types for left and right operand. Determine whether they constitute
211 -- a valid pair for the given operator, and record the corresponding
212 -- interpretation of the operator node. The node N may be an operator
213 -- node (the usual case) or a function call whose prefix is an operator
214 -- designator. In both cases Op_Id is the operator name itself.
216 procedure Diagnose_Call (N : Node_Id; Nam : Node_Id);
217 -- Give detailed information on overloaded call where none of the
218 -- interpretations match. N is the call node, Nam the designator for
219 -- the overloaded entity being called.
221 function Junk_Operand (N : Node_Id) return Boolean;
222 -- Test for an operand that is an inappropriate entity (e.g. a package
223 -- name or a label). If so, issue an error message and return True. If
224 -- the operand is not an inappropriate entity kind, return False.
226 procedure Operator_Check (N : Node_Id);
227 -- Verify that an operator has received some valid interpretation. If none
228 -- was found, determine whether a use clause would make the operation
229 -- legal. The variable Candidate_Type (defined in Sem_Type) is set for
230 -- every type compatible with the operator, even if the operator for the
231 -- type is not directly visible. The routine uses this type to emit a more
232 -- informative message.
234 function Process_Implicit_Dereference_Prefix
236 P : Node_Id) return Entity_Id;
237 -- Called when P is the prefix of an implicit dereference, denoting an
238 -- object E. The function returns the designated type of the prefix, taking
239 -- into account that the designated type of an anonymous access type may be
240 -- a limited view, when the non-limited view is visible.
241 -- If in semantics only mode (-gnatc or generic), the function also records
242 -- that the prefix is a reference to E, if any. Normally, such a reference
243 -- is generated only when the implicit dereference is expanded into an
244 -- explicit one, but for consistency we must generate the reference when
245 -- expansion is disabled as well.
247 procedure Remove_Abstract_Operations (N : Node_Id);
248 -- Ada 2005: implementation of AI-310. An abstract non-dispatching
249 -- operation is not a candidate interpretation.
251 function Try_Indexed_Call
255 Skip_First : Boolean) return Boolean;
256 -- If a function has defaults for all its actuals, a call to it may in fact
257 -- be an indexing on the result of the call. Try_Indexed_Call attempts the
258 -- interpretation as an indexing, prior to analysis as a call. If both are
259 -- possible, the node is overloaded with both interpretations (same symbol
260 -- but two different types). If the call is written in prefix form, the
261 -- prefix becomes the first parameter in the call, and only the remaining
262 -- actuals must be checked for the presence of defaults.
264 function Try_Indirect_Call
267 Typ : Entity_Id) return Boolean;
268 -- Similarly, a function F that needs no actuals can return an access to a
269 -- subprogram, and the call F (X) interpreted as F.all (X). In this case
270 -- the call may be overloaded with both interpretations.
272 function Try_Object_Operation (N : Node_Id) return Boolean;
273 -- Ada 2005 (AI-252): Support the object.operation notation. If node N
274 -- is a call in this notation, it is transformed into a normal subprogram
275 -- call where the prefix is a parameter, and True is returned. If node
276 -- N is not of this form, it is unchanged, and False is returned.
278 procedure wpo (T : Entity_Id);
279 pragma Warnings (Off, wpo);
280 -- Used for debugging: obtain list of primitive operations even if
281 -- type is not frozen and dispatch table is not built yet.
283 ------------------------
284 -- Ambiguous_Operands --
285 ------------------------
287 procedure Ambiguous_Operands (N : Node_Id) is
288 procedure List_Operand_Interps (Opnd : Node_Id);
290 --------------------------
291 -- List_Operand_Interps --
292 --------------------------
294 procedure List_Operand_Interps (Opnd : Node_Id) is
299 if Is_Overloaded (Opnd) then
300 if Nkind (Opnd) in N_Op then
302 elsif Nkind (Opnd) = N_Function_Call then
304 elsif Ada_Version >= Ada_2012 then
310 Get_First_Interp (Opnd, I, It);
311 while Present (It.Nam) loop
312 if Has_Implicit_Dereference (It.Typ) then
314 ("can be interpreted as implicit dereference", Opnd);
318 Get_Next_Interp (I, It);
329 if Opnd = Left_Opnd (N) then
330 Error_Msg_N ("\left operand has the following interpretations", N);
333 ("\right operand has the following interpretations", N);
337 List_Interps (Nam, Err);
338 end List_Operand_Interps;
340 -- Start of processing for Ambiguous_Operands
343 if Nkind (N) in N_Membership_Test then
344 Error_Msg_N ("ambiguous operands for membership", N);
346 elsif Nkind_In (N, N_Op_Eq, N_Op_Ne) then
347 Error_Msg_N ("ambiguous operands for equality", N);
350 Error_Msg_N ("ambiguous operands for comparison", N);
353 if All_Errors_Mode then
354 List_Operand_Interps (Left_Opnd (N));
355 List_Operand_Interps (Right_Opnd (N));
357 Error_Msg_N ("\use -gnatf switch for details", N);
359 end Ambiguous_Operands;
361 -----------------------
362 -- Analyze_Aggregate --
363 -----------------------
365 -- Most of the analysis of Aggregates requires that the type be known,
366 -- and is therefore put off until resolution.
368 procedure Analyze_Aggregate (N : Node_Id) is
370 if No (Etype (N)) then
371 Set_Etype (N, Any_Composite);
373 end Analyze_Aggregate;
375 -----------------------
376 -- Analyze_Allocator --
377 -----------------------
379 procedure Analyze_Allocator (N : Node_Id) is
380 Loc : constant Source_Ptr := Sloc (N);
381 Sav_Errs : constant Nat := Serious_Errors_Detected;
382 E : Node_Id := Expression (N);
383 Acc_Type : Entity_Id;
389 Check_SPARK_Restriction ("allocator is not allowed", N);
391 -- Deal with allocator restrictions
393 -- In accordance with H.4(7), the No_Allocators restriction only applies
394 -- to user-written allocators. The same consideration applies to the
395 -- No_Allocators_Before_Elaboration restriction.
397 if Comes_From_Source (N) then
398 Check_Restriction (No_Allocators, N);
400 -- Processing for No_Allocators_After_Elaboration, loop to look at
401 -- enclosing context, checking task case and main subprogram case.
405 while Present (P) loop
407 -- In both cases we need a handled sequence of statements, where
408 -- the occurrence of the allocator is within the statements.
410 if Nkind (P) = N_Handled_Sequence_Of_Statements
411 and then Is_List_Member (C)
412 and then List_Containing (C) = Statements (P)
414 -- Check for allocator within task body, this is a definite
415 -- violation of No_Allocators_After_Elaboration we can detect.
417 if Nkind (Original_Node (Parent (P))) = N_Task_Body then
418 Check_Restriction (No_Allocators_After_Elaboration, N);
422 -- The other case is appearance in a subprogram body. This may
423 -- be a violation if this is a library level subprogram, and it
424 -- turns out to be used as the main program, but only the
425 -- binder knows that, so just record the occurrence.
427 if Nkind (Original_Node (Parent (P))) = N_Subprogram_Body
428 and then Nkind (Parent (Parent (P))) = N_Compilation_Unit
430 Set_Has_Allocator (Current_Sem_Unit);
439 -- Analyze the allocator
441 if Nkind (E) = N_Qualified_Expression then
442 Acc_Type := Create_Itype (E_Allocator_Type, N);
443 Set_Etype (Acc_Type, Acc_Type);
444 Find_Type (Subtype_Mark (E));
446 -- Analyze the qualified expression, and apply the name resolution
447 -- rule given in 4.7 (3).
450 Type_Id := Etype (E);
451 Set_Directly_Designated_Type (Acc_Type, Type_Id);
453 Resolve (Expression (E), Type_Id);
455 if Is_Limited_Type (Type_Id)
456 and then Comes_From_Source (N)
457 and then not In_Instance_Body
459 if not OK_For_Limited_Init (Type_Id, Expression (E)) then
460 Error_Msg_N ("initialization not allowed for limited types", N);
461 Explain_Limited_Type (Type_Id, N);
465 -- A qualified expression requires an exact match of the type,
466 -- class-wide matching is not allowed.
468 -- if Is_Class_Wide_Type (Type_Id)
469 -- and then Base_Type
470 -- (Etype (Expression (E))) /= Base_Type (Type_Id)
472 -- Wrong_Type (Expression (E), Type_Id);
475 Check_Non_Static_Context (Expression (E));
477 -- We don't analyze the qualified expression itself because it's
478 -- part of the allocator
480 Set_Etype (E, Type_Id);
482 -- Case where allocator has a subtype indication
487 Base_Typ : Entity_Id;
490 -- If the allocator includes a N_Subtype_Indication then a
491 -- constraint is present, otherwise the node is a subtype mark.
492 -- Introduce an explicit subtype declaration into the tree
493 -- defining some anonymous subtype and rewrite the allocator to
494 -- use this subtype rather than the subtype indication.
496 -- It is important to introduce the explicit subtype declaration
497 -- so that the bounds of the subtype indication are attached to
498 -- the tree in case the allocator is inside a generic unit.
500 if Nkind (E) = N_Subtype_Indication then
502 -- A constraint is only allowed for a composite type in Ada
503 -- 95. In Ada 83, a constraint is also allowed for an
504 -- access-to-composite type, but the constraint is ignored.
506 Find_Type (Subtype_Mark (E));
507 Base_Typ := Entity (Subtype_Mark (E));
509 if Is_Elementary_Type (Base_Typ) then
510 if not (Ada_Version = Ada_83
511 and then Is_Access_Type (Base_Typ))
513 Error_Msg_N ("constraint not allowed here", E);
515 if Nkind (Constraint (E)) =
516 N_Index_Or_Discriminant_Constraint
518 Error_Msg_N -- CODEFIX
519 ("\if qualified expression was meant, " &
520 "use apostrophe", Constraint (E));
524 -- Get rid of the bogus constraint:
526 Rewrite (E, New_Copy_Tree (Subtype_Mark (E)));
527 Analyze_Allocator (N);
530 -- Ada 2005, AI-363: if the designated type has a constrained
531 -- partial view, it cannot receive a discriminant constraint,
532 -- and the allocated object is unconstrained.
534 elsif Ada_Version >= Ada_2005
535 and then Has_Constrained_Partial_View (Base_Typ)
538 ("constraint no allowed when type " &
539 "has a constrained partial view", Constraint (E));
542 if Expander_Active then
543 Def_Id := Make_Temporary (Loc, 'S');
546 Make_Subtype_Declaration (Loc,
547 Defining_Identifier => Def_Id,
548 Subtype_Indication => Relocate_Node (E)));
550 if Sav_Errs /= Serious_Errors_Detected
551 and then Nkind (Constraint (E)) =
552 N_Index_Or_Discriminant_Constraint
554 Error_Msg_N -- CODEFIX
555 ("if qualified expression was meant, " &
556 "use apostrophe!", Constraint (E));
559 E := New_Occurrence_Of (Def_Id, Loc);
560 Rewrite (Expression (N), E);
564 Type_Id := Process_Subtype (E, N);
565 Acc_Type := Create_Itype (E_Allocator_Type, N);
566 Set_Etype (Acc_Type, Acc_Type);
567 Set_Directly_Designated_Type (Acc_Type, Type_Id);
568 Check_Fully_Declared (Type_Id, N);
570 -- Ada 2005 (AI-231): If the designated type is itself an access
571 -- type that excludes null, its default initialization will
572 -- be a null object, and we can insert an unconditional raise
573 -- before the allocator.
575 -- Ada 2012 (AI-104): A not null indication here is altogether
578 if Can_Never_Be_Null (Type_Id) then
580 Not_Null_Check : constant Node_Id :=
581 Make_Raise_Constraint_Error (Sloc (E),
582 Reason => CE_Null_Not_Allowed);
585 if Ada_Version >= Ada_2012 then
587 ("an uninitialized allocator cannot have"
588 & " a null exclusion", N);
590 elsif Expander_Active then
591 Insert_Action (N, Not_Null_Check);
592 Analyze (Not_Null_Check);
595 Error_Msg_N ("null value not allowed here?", E);
600 -- Check restriction against dynamically allocated protected
601 -- objects. Note that when limited aggregates are supported,
602 -- a similar test should be applied to an allocator with a
603 -- qualified expression ???
605 if Is_Protected_Type (Type_Id) then
606 Check_Restriction (No_Protected_Type_Allocators, N);
609 -- Check for missing initialization. Skip this check if we already
610 -- had errors on analyzing the allocator, since in that case these
611 -- are probably cascaded errors.
613 if Is_Indefinite_Subtype (Type_Id)
614 and then Serious_Errors_Detected = Sav_Errs
616 if Is_Class_Wide_Type (Type_Id) then
618 ("initialization required in class-wide allocation", N);
620 if Ada_Version < Ada_2005
621 and then Is_Limited_Type (Type_Id)
623 Error_Msg_N ("unconstrained allocation not allowed", N);
625 if Is_Array_Type (Type_Id) then
627 ("\constraint with array bounds required", N);
629 elsif Has_Unknown_Discriminants (Type_Id) then
632 else pragma Assert (Has_Discriminants (Type_Id));
634 ("\constraint with discriminant values required", N);
637 -- Limited Ada 2005 and general non-limited case
641 ("uninitialized unconstrained allocation not allowed",
644 if Is_Array_Type (Type_Id) then
646 ("\qualified expression or constraint with " &
647 "array bounds required", N);
649 elsif Has_Unknown_Discriminants (Type_Id) then
650 Error_Msg_N ("\qualified expression required", N);
652 else pragma Assert (Has_Discriminants (Type_Id));
654 ("\qualified expression or constraint with " &
655 "discriminant values required", N);
663 if Is_Abstract_Type (Type_Id) then
664 Error_Msg_N ("cannot allocate abstract object", E);
667 if Has_Task (Designated_Type (Acc_Type)) then
668 Check_Restriction (No_Tasking, N);
669 Check_Restriction (Max_Tasks, N);
670 Check_Restriction (No_Task_Allocators, N);
673 -- Check that an allocator of a nested access type doesn't create a
674 -- protected object when restriction No_Local_Protected_Objects applies.
675 -- We don't have an equivalent to Has_Task for protected types, so only
676 -- cases where the designated type itself is a protected type are
677 -- currently checked. ???
679 if Is_Protected_Type (Designated_Type (Acc_Type))
680 and then not Is_Library_Level_Entity (Acc_Type)
682 Check_Restriction (No_Local_Protected_Objects, N);
685 -- If the No_Streams restriction is set, check that the type of the
686 -- object is not, and does not contain, any subtype derived from
687 -- Ada.Streams.Root_Stream_Type. Note that we guard the call to
688 -- Has_Stream just for efficiency reasons. There is no point in
689 -- spending time on a Has_Stream check if the restriction is not set.
691 if Restriction_Check_Required (No_Streams) then
692 if Has_Stream (Designated_Type (Acc_Type)) then
693 Check_Restriction (No_Streams, N);
697 Set_Etype (N, Acc_Type);
699 if not Is_Library_Level_Entity (Acc_Type) then
700 Check_Restriction (No_Local_Allocators, N);
703 if Serious_Errors_Detected > Sav_Errs then
704 Set_Error_Posted (N);
705 Set_Etype (N, Any_Type);
707 end Analyze_Allocator;
709 ---------------------------
710 -- Analyze_Arithmetic_Op --
711 ---------------------------
713 procedure Analyze_Arithmetic_Op (N : Node_Id) is
714 L : constant Node_Id := Left_Opnd (N);
715 R : constant Node_Id := Right_Opnd (N);
719 Candidate_Type := Empty;
720 Analyze_Expression (L);
721 Analyze_Expression (R);
723 -- If the entity is already set, the node is the instantiation of a
724 -- generic node with a non-local reference, or was manufactured by a
725 -- call to Make_Op_xxx. In either case the entity is known to be valid,
726 -- and we do not need to collect interpretations, instead we just get
727 -- the single possible interpretation.
731 if Present (Op_Id) then
732 if Ekind (Op_Id) = E_Operator then
734 if Nkind_In (N, N_Op_Divide, N_Op_Mod, N_Op_Multiply, N_Op_Rem)
735 and then Treat_Fixed_As_Integer (N)
739 Set_Etype (N, Any_Type);
740 Find_Arithmetic_Types (L, R, Op_Id, N);
744 Set_Etype (N, Any_Type);
745 Add_One_Interp (N, Op_Id, Etype (Op_Id));
748 -- Entity is not already set, so we do need to collect interpretations
751 Op_Id := Get_Name_Entity_Id (Chars (N));
752 Set_Etype (N, Any_Type);
754 while Present (Op_Id) loop
755 if Ekind (Op_Id) = E_Operator
756 and then Present (Next_Entity (First_Entity (Op_Id)))
758 Find_Arithmetic_Types (L, R, Op_Id, N);
760 -- The following may seem superfluous, because an operator cannot
761 -- be generic, but this ignores the cleverness of the author of
764 elsif Is_Overloadable (Op_Id) then
765 Analyze_User_Defined_Binary_Op (N, Op_Id);
768 Op_Id := Homonym (Op_Id);
773 end Analyze_Arithmetic_Op;
779 -- Function, procedure, and entry calls are checked here. The Name in
780 -- the call may be overloaded. The actuals have been analyzed and may
781 -- themselves be overloaded. On exit from this procedure, the node N
782 -- may have zero, one or more interpretations. In the first case an
783 -- error message is produced. In the last case, the node is flagged
784 -- as overloaded and the interpretations are collected in All_Interp.
786 -- If the name is an Access_To_Subprogram, it cannot be overloaded, but
787 -- the type-checking is similar to that of other calls.
789 procedure Analyze_Call (N : Node_Id) is
790 Actuals : constant List_Id := Parameter_Associations (N);
795 Success : Boolean := False;
797 Deref : Boolean := False;
798 -- Flag indicates whether an interpretation of the prefix is a
799 -- parameterless call that returns an access_to_subprogram.
801 procedure Check_Mixed_Parameter_And_Named_Associations;
802 -- Check that parameter and named associations are not mixed. This is
803 -- a restriction in SPARK mode.
805 function Name_Denotes_Function return Boolean;
806 -- If the type of the name is an access to subprogram, this may be the
807 -- type of a name, or the return type of the function being called. If
808 -- the name is not an entity then it can denote a protected function.
809 -- Until we distinguish Etype from Return_Type, we must use this routine
810 -- to resolve the meaning of the name in the call.
812 procedure No_Interpretation;
813 -- Output error message when no valid interpretation exists
815 --------------------------------------------------
816 -- Check_Mixed_Parameter_And_Named_Associations --
817 --------------------------------------------------
819 procedure Check_Mixed_Parameter_And_Named_Associations is
821 Named_Seen : Boolean;
826 Actual := First (Actuals);
827 while Present (Actual) loop
828 case Nkind (Actual) is
829 when N_Parameter_Association =>
831 Check_SPARK_Restriction
832 ("named association cannot follow positional one",
842 end Check_Mixed_Parameter_And_Named_Associations;
844 ---------------------------
845 -- Name_Denotes_Function --
846 ---------------------------
848 function Name_Denotes_Function return Boolean is
850 if Is_Entity_Name (Nam) then
851 return Ekind (Entity (Nam)) = E_Function;
853 elsif Nkind (Nam) = N_Selected_Component then
854 return Ekind (Entity (Selector_Name (Nam))) = E_Function;
859 end Name_Denotes_Function;
861 -----------------------
862 -- No_Interpretation --
863 -----------------------
865 procedure No_Interpretation is
866 L : constant Boolean := Is_List_Member (N);
867 K : constant Node_Kind := Nkind (Parent (N));
870 -- If the node is in a list whose parent is not an expression then it
871 -- must be an attempted procedure call.
873 if L and then K not in N_Subexpr then
874 if Ekind (Entity (Nam)) = E_Generic_Procedure then
876 ("must instantiate generic procedure& before call",
880 ("procedure or entry name expected", Nam);
883 -- Check for tasking cases where only an entry call will do
886 and then Nkind_In (K, N_Entry_Call_Alternative,
887 N_Triggering_Alternative)
889 Error_Msg_N ("entry name expected", Nam);
891 -- Otherwise give general error message
894 Error_Msg_N ("invalid prefix in call", Nam);
896 end No_Interpretation;
898 -- Start of processing for Analyze_Call
901 if Restriction_Check_Required (SPARK) then
902 Check_Mixed_Parameter_And_Named_Associations;
905 -- Initialize the type of the result of the call to the error type,
906 -- which will be reset if the type is successfully resolved.
908 Set_Etype (N, Any_Type);
912 if not Is_Overloaded (Nam) then
914 -- Only one interpretation to check
916 if Ekind (Etype (Nam)) = E_Subprogram_Type then
917 Nam_Ent := Etype (Nam);
919 -- If the prefix is an access_to_subprogram, this may be an indirect
920 -- call. This is the case if the name in the call is not an entity
921 -- name, or if it is a function name in the context of a procedure
922 -- call. In this latter case, we have a call to a parameterless
923 -- function that returns a pointer_to_procedure which is the entity
924 -- being called. Finally, F (X) may be a call to a parameterless
925 -- function that returns a pointer to a function with parameters.
927 elsif Is_Access_Type (Etype (Nam))
928 and then Ekind (Designated_Type (Etype (Nam))) = E_Subprogram_Type
930 (not Name_Denotes_Function
931 or else Nkind (N) = N_Procedure_Call_Statement
933 (Nkind (Parent (N)) /= N_Explicit_Dereference
934 and then Is_Entity_Name (Nam)
935 and then No (First_Formal (Entity (Nam)))
936 and then Present (Actuals)))
938 Nam_Ent := Designated_Type (Etype (Nam));
939 Insert_Explicit_Dereference (Nam);
941 -- Selected component case. Simple entry or protected operation,
942 -- where the entry name is given by the selector name.
944 elsif Nkind (Nam) = N_Selected_Component then
945 Nam_Ent := Entity (Selector_Name (Nam));
947 if not Ekind_In (Nam_Ent, E_Entry,
952 Error_Msg_N ("name in call is not a callable entity", Nam);
953 Set_Etype (N, Any_Type);
957 -- If the name is an Indexed component, it can be a call to a member
958 -- of an entry family. The prefix must be a selected component whose
959 -- selector is the entry. Analyze_Procedure_Call normalizes several
960 -- kinds of call into this form.
962 elsif Nkind (Nam) = N_Indexed_Component then
963 if Nkind (Prefix (Nam)) = N_Selected_Component then
964 Nam_Ent := Entity (Selector_Name (Prefix (Nam)));
966 Error_Msg_N ("name in call is not a callable entity", Nam);
967 Set_Etype (N, Any_Type);
971 elsif not Is_Entity_Name (Nam) then
972 Error_Msg_N ("name in call is not a callable entity", Nam);
973 Set_Etype (N, Any_Type);
977 Nam_Ent := Entity (Nam);
979 -- If no interpretations, give error message
981 if not Is_Overloadable (Nam_Ent) then
987 -- Operations generated for RACW stub types are called only through
988 -- dispatching, and can never be the static interpretation of a call.
990 if Is_RACW_Stub_Type_Operation (Nam_Ent) then
995 Analyze_One_Call (N, Nam_Ent, True, Success);
997 -- If this is an indirect call, the return type of the access_to
998 -- subprogram may be an incomplete type. At the point of the call,
999 -- use the full type if available, and at the same time update the
1000 -- return type of the access_to_subprogram.
1003 and then Nkind (Nam) = N_Explicit_Dereference
1004 and then Ekind (Etype (N)) = E_Incomplete_Type
1005 and then Present (Full_View (Etype (N)))
1007 Set_Etype (N, Full_View (Etype (N)));
1008 Set_Etype (Nam_Ent, Etype (N));
1012 -- An overloaded selected component must denote overloaded operations
1013 -- of a concurrent type. The interpretations are attached to the
1014 -- simple name of those operations.
1016 if Nkind (Nam) = N_Selected_Component then
1017 Nam := Selector_Name (Nam);
1020 Get_First_Interp (Nam, X, It);
1022 while Present (It.Nam) loop
1026 -- Name may be call that returns an access to subprogram, or more
1027 -- generally an overloaded expression one of whose interpretations
1028 -- yields an access to subprogram. If the name is an entity, we do
1029 -- not dereference, because the node is a call that returns the
1030 -- access type: note difference between f(x), where the call may
1031 -- return an access subprogram type, and f(x)(y), where the type
1032 -- returned by the call to f is implicitly dereferenced to analyze
1035 if Is_Access_Type (Nam_Ent) then
1036 Nam_Ent := Designated_Type (Nam_Ent);
1038 elsif Is_Access_Type (Etype (Nam_Ent))
1040 (not Is_Entity_Name (Nam)
1041 or else Nkind (N) = N_Procedure_Call_Statement)
1042 and then Ekind (Designated_Type (Etype (Nam_Ent)))
1045 Nam_Ent := Designated_Type (Etype (Nam_Ent));
1047 if Is_Entity_Name (Nam) then
1052 -- If the call has been rewritten from a prefixed call, the first
1053 -- parameter has been analyzed, but may need a subsequent
1054 -- dereference, so skip its analysis now.
1056 if N /= Original_Node (N)
1057 and then Nkind (Original_Node (N)) = Nkind (N)
1058 and then Nkind (Name (N)) /= Nkind (Name (Original_Node (N)))
1059 and then Present (Parameter_Associations (N))
1060 and then Present (Etype (First (Parameter_Associations (N))))
1063 (N, Nam_Ent, False, Success, Skip_First => True);
1065 Analyze_One_Call (N, Nam_Ent, False, Success);
1068 -- If the interpretation succeeds, mark the proper type of the
1069 -- prefix (any valid candidate will do). If not, remove the
1070 -- candidate interpretation. This only needs to be done for
1071 -- overloaded protected operations, for other entities disambi-
1072 -- guation is done directly in Resolve.
1076 and then Nkind (Parent (N)) /= N_Explicit_Dereference
1078 Set_Entity (Nam, It.Nam);
1079 Insert_Explicit_Dereference (Nam);
1080 Set_Etype (Nam, Nam_Ent);
1083 Set_Etype (Nam, It.Typ);
1086 elsif Nkind_In (Name (N), N_Selected_Component,
1092 Get_Next_Interp (X, It);
1095 -- If the name is the result of a function call, it can only
1096 -- be a call to a function returning an access to subprogram.
1097 -- Insert explicit dereference.
1099 if Nkind (Nam) = N_Function_Call then
1100 Insert_Explicit_Dereference (Nam);
1103 if Etype (N) = Any_Type then
1105 -- None of the interpretations is compatible with the actuals
1107 Diagnose_Call (N, Nam);
1109 -- Special checks for uninstantiated put routines
1111 if Nkind (N) = N_Procedure_Call_Statement
1112 and then Is_Entity_Name (Nam)
1113 and then Chars (Nam) = Name_Put
1114 and then List_Length (Actuals) = 1
1117 Arg : constant Node_Id := First (Actuals);
1121 if Nkind (Arg) = N_Parameter_Association then
1122 Typ := Etype (Explicit_Actual_Parameter (Arg));
1127 if Is_Signed_Integer_Type (Typ) then
1129 ("possible missing instantiation of " &
1130 "'Text_'I'O.'Integer_'I'O!", Nam);
1132 elsif Is_Modular_Integer_Type (Typ) then
1134 ("possible missing instantiation of " &
1135 "'Text_'I'O.'Modular_'I'O!", Nam);
1137 elsif Is_Floating_Point_Type (Typ) then
1139 ("possible missing instantiation of " &
1140 "'Text_'I'O.'Float_'I'O!", Nam);
1142 elsif Is_Ordinary_Fixed_Point_Type (Typ) then
1144 ("possible missing instantiation of " &
1145 "'Text_'I'O.'Fixed_'I'O!", Nam);
1147 elsif Is_Decimal_Fixed_Point_Type (Typ) then
1149 ("possible missing instantiation of " &
1150 "'Text_'I'O.'Decimal_'I'O!", Nam);
1152 elsif Is_Enumeration_Type (Typ) then
1154 ("possible missing instantiation of " &
1155 "'Text_'I'O.'Enumeration_'I'O!", Nam);
1160 elsif not Is_Overloaded (N)
1161 and then Is_Entity_Name (Nam)
1163 -- Resolution yields a single interpretation. Verify that the
1164 -- reference has capitalization consistent with the declaration.
1166 Set_Entity_With_Style_Check (Nam, Entity (Nam));
1167 Generate_Reference (Entity (Nam), Nam);
1169 Set_Etype (Nam, Etype (Entity (Nam)));
1171 Remove_Abstract_Operations (N);
1178 -----------------------------
1179 -- Analyze_Case_Expression --
1180 -----------------------------
1182 procedure Analyze_Case_Expression (N : Node_Id) is
1183 Expr : constant Node_Id := Expression (N);
1184 FirstX : constant Node_Id := Expression (First (Alternatives (N)));
1186 Exp_Type : Entity_Id;
1187 Exp_Btype : Entity_Id;
1189 Dont_Care : Boolean;
1190 Others_Present : Boolean;
1192 procedure Non_Static_Choice_Error (Choice : Node_Id);
1193 -- Error routine invoked by the generic instantiation below when
1194 -- the case expression has a non static choice.
1196 package Case_Choices_Processing is new
1197 Generic_Choices_Processing
1198 (Get_Alternatives => Alternatives,
1199 Get_Choices => Discrete_Choices,
1200 Process_Empty_Choice => No_OP,
1201 Process_Non_Static_Choice => Non_Static_Choice_Error,
1202 Process_Associated_Node => No_OP);
1203 use Case_Choices_Processing;
1205 -----------------------------
1206 -- Non_Static_Choice_Error --
1207 -----------------------------
1209 procedure Non_Static_Choice_Error (Choice : Node_Id) is
1211 Flag_Non_Static_Expr
1212 ("choice given in case expression is not static!", Choice);
1213 end Non_Static_Choice_Error;
1215 -- Start of processing for Analyze_Case_Expression
1218 if Comes_From_Source (N) then
1219 Check_Compiler_Unit (N);
1222 Analyze_And_Resolve (Expr, Any_Discrete);
1223 Check_Unset_Reference (Expr);
1224 Exp_Type := Etype (Expr);
1225 Exp_Btype := Base_Type (Exp_Type);
1227 Alt := First (Alternatives (N));
1228 while Present (Alt) loop
1229 Analyze (Expression (Alt));
1233 if not Is_Overloaded (FirstX) then
1234 Set_Etype (N, Etype (FirstX));
1242 Set_Etype (N, Any_Type);
1244 Get_First_Interp (FirstX, I, It);
1245 while Present (It.Nam) loop
1247 -- For each interpretation of the first expression, we only
1248 -- add the interpretation if every other expression in the
1249 -- case expression alternatives has a compatible type.
1251 Alt := Next (First (Alternatives (N)));
1252 while Present (Alt) loop
1253 exit when not Has_Compatible_Type (Expression (Alt), It.Typ);
1258 Add_One_Interp (N, It.Typ, It.Typ);
1261 Get_Next_Interp (I, It);
1266 Exp_Btype := Base_Type (Exp_Type);
1268 -- The expression must be of a discrete type which must be determinable
1269 -- independently of the context in which the expression occurs, but
1270 -- using the fact that the expression must be of a discrete type.
1271 -- Moreover, the type this expression must not be a character literal
1272 -- (which is always ambiguous).
1274 -- If error already reported by Resolve, nothing more to do
1276 if Exp_Btype = Any_Discrete
1277 or else Exp_Btype = Any_Type
1281 elsif Exp_Btype = Any_Character then
1283 ("character literal as case expression is ambiguous", Expr);
1287 -- If the case expression is a formal object of mode in out, then
1288 -- treat it as having a nonstatic subtype by forcing use of the base
1289 -- type (which has to get passed to Check_Case_Choices below). Also
1290 -- use base type when the case expression is parenthesized.
1292 if Paren_Count (Expr) > 0
1293 or else (Is_Entity_Name (Expr)
1294 and then Ekind (Entity (Expr)) = E_Generic_In_Out_Parameter)
1296 Exp_Type := Exp_Btype;
1299 -- Call instantiated Analyze_Choices which does the rest of the work
1301 Analyze_Choices (N, Exp_Type, Dont_Care, Others_Present);
1303 if Exp_Type = Universal_Integer and then not Others_Present then
1305 ("case on universal integer requires OTHERS choice", Expr);
1307 end Analyze_Case_Expression;
1309 ---------------------------
1310 -- Analyze_Comparison_Op --
1311 ---------------------------
1313 procedure Analyze_Comparison_Op (N : Node_Id) is
1314 L : constant Node_Id := Left_Opnd (N);
1315 R : constant Node_Id := Right_Opnd (N);
1316 Op_Id : Entity_Id := Entity (N);
1319 Set_Etype (N, Any_Type);
1320 Candidate_Type := Empty;
1322 Analyze_Expression (L);
1323 Analyze_Expression (R);
1325 if Present (Op_Id) then
1326 if Ekind (Op_Id) = E_Operator then
1327 Find_Comparison_Types (L, R, Op_Id, N);
1329 Add_One_Interp (N, Op_Id, Etype (Op_Id));
1332 if Is_Overloaded (L) then
1333 Set_Etype (L, Intersect_Types (L, R));
1337 Op_Id := Get_Name_Entity_Id (Chars (N));
1338 while Present (Op_Id) loop
1339 if Ekind (Op_Id) = E_Operator then
1340 Find_Comparison_Types (L, R, Op_Id, N);
1342 Analyze_User_Defined_Binary_Op (N, Op_Id);
1345 Op_Id := Homonym (Op_Id);
1350 end Analyze_Comparison_Op;
1352 ---------------------------
1353 -- Analyze_Concatenation --
1354 ---------------------------
1356 procedure Analyze_Concatenation (N : Node_Id) is
1358 -- We wish to avoid deep recursion, because concatenations are often
1359 -- deeply nested, as in A&B&...&Z. Therefore, we walk down the left
1360 -- operands nonrecursively until we find something that is not a
1361 -- concatenation (A in this case), or has already been analyzed. We
1362 -- analyze that, and then walk back up the tree following Parent
1363 -- pointers, calling Analyze_Concatenation_Rest to do the rest of the
1364 -- work at each level. The Parent pointers allow us to avoid recursion,
1365 -- and thus avoid running out of memory.
1371 Candidate_Type := Empty;
1373 -- The following code is equivalent to:
1375 -- Set_Etype (N, Any_Type);
1376 -- Analyze_Expression (Left_Opnd (N));
1377 -- Analyze_Concatenation_Rest (N);
1379 -- where the Analyze_Expression call recurses back here if the left
1380 -- operand is a concatenation.
1382 -- Walk down left operands
1385 Set_Etype (NN, Any_Type);
1386 L := Left_Opnd (NN);
1387 exit when Nkind (L) /= N_Op_Concat or else Analyzed (L);
1391 -- Now (given the above example) NN is A&B and L is A
1393 -- First analyze L ...
1395 Analyze_Expression (L);
1397 -- ... then walk NN back up until we reach N (where we started), calling
1398 -- Analyze_Concatenation_Rest along the way.
1401 Analyze_Concatenation_Rest (NN);
1405 end Analyze_Concatenation;
1407 --------------------------------
1408 -- Analyze_Concatenation_Rest --
1409 --------------------------------
1411 -- If the only one-dimensional array type in scope is String,
1412 -- this is the resulting type of the operation. Otherwise there
1413 -- will be a concatenation operation defined for each user-defined
1414 -- one-dimensional array.
1416 procedure Analyze_Concatenation_Rest (N : Node_Id) is
1417 L : constant Node_Id := Left_Opnd (N);
1418 R : constant Node_Id := Right_Opnd (N);
1419 Op_Id : Entity_Id := Entity (N);
1424 Analyze_Expression (R);
1426 -- If the entity is present, the node appears in an instance, and
1427 -- denotes a predefined concatenation operation. The resulting type is
1428 -- obtained from the arguments when possible. If the arguments are
1429 -- aggregates, the array type and the concatenation type must be
1432 if Present (Op_Id) then
1433 if Ekind (Op_Id) = E_Operator then
1434 LT := Base_Type (Etype (L));
1435 RT := Base_Type (Etype (R));
1437 if Is_Array_Type (LT)
1438 and then (RT = LT or else RT = Base_Type (Component_Type (LT)))
1440 Add_One_Interp (N, Op_Id, LT);
1442 elsif Is_Array_Type (RT)
1443 and then LT = Base_Type (Component_Type (RT))
1445 Add_One_Interp (N, Op_Id, RT);
1447 -- If one operand is a string type or a user-defined array type,
1448 -- and the other is a literal, result is of the specific type.
1451 (Root_Type (LT) = Standard_String
1452 or else Scope (LT) /= Standard_Standard)
1453 and then Etype (R) = Any_String
1455 Add_One_Interp (N, Op_Id, LT);
1458 (Root_Type (RT) = Standard_String
1459 or else Scope (RT) /= Standard_Standard)
1460 and then Etype (L) = Any_String
1462 Add_One_Interp (N, Op_Id, RT);
1464 elsif not Is_Generic_Type (Etype (Op_Id)) then
1465 Add_One_Interp (N, Op_Id, Etype (Op_Id));
1468 -- Type and its operations must be visible
1470 Set_Entity (N, Empty);
1471 Analyze_Concatenation (N);
1475 Add_One_Interp (N, Op_Id, Etype (Op_Id));
1479 Op_Id := Get_Name_Entity_Id (Name_Op_Concat);
1480 while Present (Op_Id) loop
1481 if Ekind (Op_Id) = E_Operator then
1483 -- Do not consider operators declared in dead code, they can
1484 -- not be part of the resolution.
1486 if Is_Eliminated (Op_Id) then
1489 Find_Concatenation_Types (L, R, Op_Id, N);
1493 Analyze_User_Defined_Binary_Op (N, Op_Id);
1496 Op_Id := Homonym (Op_Id);
1501 end Analyze_Concatenation_Rest;
1503 ------------------------------------
1504 -- Analyze_Conditional_Expression --
1505 ------------------------------------
1507 procedure Analyze_Conditional_Expression (N : Node_Id) is
1508 Condition : constant Node_Id := First (Expressions (N));
1509 Then_Expr : constant Node_Id := Next (Condition);
1510 Else_Expr : Node_Id;
1513 -- Defend against error of missing expressions from previous error
1515 if No (Then_Expr) then
1519 Check_SPARK_Restriction ("conditional expression is not allowed", N);
1521 Else_Expr := Next (Then_Expr);
1523 if Comes_From_Source (N) then
1524 Check_Compiler_Unit (N);
1527 Analyze_Expression (Condition);
1528 Analyze_Expression (Then_Expr);
1530 if Present (Else_Expr) then
1531 Analyze_Expression (Else_Expr);
1534 -- If then expression not overloaded, then that decides the type
1536 if not Is_Overloaded (Then_Expr) then
1537 Set_Etype (N, Etype (Then_Expr));
1539 -- Case where then expression is overloaded
1547 Set_Etype (N, Any_Type);
1549 -- Shouldn't the following statement be down in the ELSE of the
1550 -- following loop? ???
1552 Get_First_Interp (Then_Expr, I, It);
1554 -- if no Else_Expression the conditional must be boolean
1556 if No (Else_Expr) then
1557 Set_Etype (N, Standard_Boolean);
1559 -- Else_Expression Present. For each possible intepretation of
1560 -- the Then_Expression, add it only if the Else_Expression has
1561 -- a compatible type.
1564 while Present (It.Nam) loop
1565 if Has_Compatible_Type (Else_Expr, It.Typ) then
1566 Add_One_Interp (N, It.Typ, It.Typ);
1569 Get_Next_Interp (I, It);
1574 end Analyze_Conditional_Expression;
1576 -------------------------
1577 -- Analyze_Equality_Op --
1578 -------------------------
1580 procedure Analyze_Equality_Op (N : Node_Id) is
1581 Loc : constant Source_Ptr := Sloc (N);
1582 L : constant Node_Id := Left_Opnd (N);
1583 R : constant Node_Id := Right_Opnd (N);
1587 Set_Etype (N, Any_Type);
1588 Candidate_Type := Empty;
1590 Analyze_Expression (L);
1591 Analyze_Expression (R);
1593 -- If the entity is set, the node is a generic instance with a non-local
1594 -- reference to the predefined operator or to a user-defined function.
1595 -- It can also be an inequality that is expanded into the negation of a
1596 -- call to a user-defined equality operator.
1598 -- For the predefined case, the result is Boolean, regardless of the
1599 -- type of the operands. The operands may even be limited, if they are
1600 -- generic actuals. If they are overloaded, label the left argument with
1601 -- the common type that must be present, or with the type of the formal
1602 -- of the user-defined function.
1604 if Present (Entity (N)) then
1605 Op_Id := Entity (N);
1607 if Ekind (Op_Id) = E_Operator then
1608 Add_One_Interp (N, Op_Id, Standard_Boolean);
1610 Add_One_Interp (N, Op_Id, Etype (Op_Id));
1613 if Is_Overloaded (L) then
1614 if Ekind (Op_Id) = E_Operator then
1615 Set_Etype (L, Intersect_Types (L, R));
1617 Set_Etype (L, Etype (First_Formal (Op_Id)));
1622 Op_Id := Get_Name_Entity_Id (Chars (N));
1623 while Present (Op_Id) loop
1624 if Ekind (Op_Id) = E_Operator then
1625 Find_Equality_Types (L, R, Op_Id, N);
1627 Analyze_User_Defined_Binary_Op (N, Op_Id);
1630 Op_Id := Homonym (Op_Id);
1634 -- If there was no match, and the operator is inequality, this may
1635 -- be a case where inequality has not been made explicit, as for
1636 -- tagged types. Analyze the node as the negation of an equality
1637 -- operation. This cannot be done earlier, because before analysis
1638 -- we cannot rule out the presence of an explicit inequality.
1640 if Etype (N) = Any_Type
1641 and then Nkind (N) = N_Op_Ne
1643 Op_Id := Get_Name_Entity_Id (Name_Op_Eq);
1644 while Present (Op_Id) loop
1645 if Ekind (Op_Id) = E_Operator then
1646 Find_Equality_Types (L, R, Op_Id, N);
1648 Analyze_User_Defined_Binary_Op (N, Op_Id);
1651 Op_Id := Homonym (Op_Id);
1654 if Etype (N) /= Any_Type then
1655 Op_Id := Entity (N);
1661 Left_Opnd => Left_Opnd (N),
1662 Right_Opnd => Right_Opnd (N))));
1664 Set_Entity (Right_Opnd (N), Op_Id);
1670 end Analyze_Equality_Op;
1672 ----------------------------------
1673 -- Analyze_Explicit_Dereference --
1674 ----------------------------------
1676 procedure Analyze_Explicit_Dereference (N : Node_Id) is
1677 Loc : constant Source_Ptr := Sloc (N);
1678 P : constant Node_Id := Prefix (N);
1684 function Is_Function_Type return Boolean;
1685 -- Check whether node may be interpreted as an implicit function call
1687 ----------------------
1688 -- Is_Function_Type --
1689 ----------------------
1691 function Is_Function_Type return Boolean is
1696 if not Is_Overloaded (N) then
1697 return Ekind (Base_Type (Etype (N))) = E_Subprogram_Type
1698 and then Etype (Base_Type (Etype (N))) /= Standard_Void_Type;
1701 Get_First_Interp (N, I, It);
1702 while Present (It.Nam) loop
1703 if Ekind (Base_Type (It.Typ)) /= E_Subprogram_Type
1704 or else Etype (Base_Type (It.Typ)) = Standard_Void_Type
1709 Get_Next_Interp (I, It);
1714 end Is_Function_Type;
1716 -- Start of processing for Analyze_Explicit_Dereference
1719 Check_SPARK_Restriction ("explicit dereference is not allowed", N);
1722 Set_Etype (N, Any_Type);
1724 -- Test for remote access to subprogram type, and if so return
1725 -- after rewriting the original tree.
1727 if Remote_AST_E_Dereference (P) then
1731 -- Normal processing for other than remote access to subprogram type
1733 if not Is_Overloaded (P) then
1734 if Is_Access_Type (Etype (P)) then
1736 -- Set the Etype. We need to go through Is_For_Access_Subtypes to
1737 -- avoid other problems caused by the Private_Subtype and it is
1738 -- safe to go to the Base_Type because this is the same as
1739 -- converting the access value to its Base_Type.
1742 DT : Entity_Id := Designated_Type (Etype (P));
1745 if Ekind (DT) = E_Private_Subtype
1746 and then Is_For_Access_Subtype (DT)
1748 DT := Base_Type (DT);
1751 -- An explicit dereference is a legal occurrence of an
1752 -- incomplete type imported through a limited_with clause,
1753 -- if the full view is visible.
1755 if From_With_Type (DT)
1756 and then not From_With_Type (Scope (DT))
1758 (Is_Immediately_Visible (Scope (DT))
1760 (Is_Child_Unit (Scope (DT))
1761 and then Is_Visible_Child_Unit (Scope (DT))))
1763 Set_Etype (N, Available_View (DT));
1770 elsif Etype (P) /= Any_Type then
1771 Error_Msg_N ("prefix of dereference must be an access type", N);
1776 Get_First_Interp (P, I, It);
1777 while Present (It.Nam) loop
1780 if Is_Access_Type (T) then
1781 Add_One_Interp (N, Designated_Type (T), Designated_Type (T));
1784 Get_Next_Interp (I, It);
1787 -- Error if no interpretation of the prefix has an access type
1789 if Etype (N) = Any_Type then
1791 ("access type required in prefix of explicit dereference", P);
1792 Set_Etype (N, Any_Type);
1798 and then Nkind (Parent (N)) /= N_Indexed_Component
1800 and then (Nkind (Parent (N)) /= N_Function_Call
1801 or else N /= Name (Parent (N)))
1803 and then (Nkind (Parent (N)) /= N_Procedure_Call_Statement
1804 or else N /= Name (Parent (N)))
1806 and then Nkind (Parent (N)) /= N_Subprogram_Renaming_Declaration
1807 and then (Nkind (Parent (N)) /= N_Attribute_Reference
1809 (Attribute_Name (Parent (N)) /= Name_Address
1811 Attribute_Name (Parent (N)) /= Name_Access))
1813 -- Name is a function call with no actuals, in a context that
1814 -- requires deproceduring (including as an actual in an enclosing
1815 -- function or procedure call). There are some pathological cases
1816 -- where the prefix might include functions that return access to
1817 -- subprograms and others that return a regular type. Disambiguation
1818 -- of those has to take place in Resolve.
1821 Make_Function_Call (Loc,
1822 Name => Make_Explicit_Dereference (Loc, P),
1823 Parameter_Associations => New_List);
1825 -- If the prefix is overloaded, remove operations that have formals,
1826 -- we know that this is a parameterless call.
1828 if Is_Overloaded (P) then
1829 Get_First_Interp (P, I, It);
1830 while Present (It.Nam) loop
1833 if No (First_Formal (Base_Type (Designated_Type (T)))) then
1839 Get_Next_Interp (I, It);
1846 elsif not Is_Function_Type
1847 and then Is_Overloaded (N)
1849 -- The prefix may include access to subprograms and other access
1850 -- types. If the context selects the interpretation that is a
1851 -- function call (not a procedure call) we cannot rewrite the node
1852 -- yet, but we include the result of the call interpretation.
1854 Get_First_Interp (N, I, It);
1855 while Present (It.Nam) loop
1856 if Ekind (Base_Type (It.Typ)) = E_Subprogram_Type
1857 and then Etype (Base_Type (It.Typ)) /= Standard_Void_Type
1858 and then Nkind (Parent (N)) /= N_Procedure_Call_Statement
1860 Add_One_Interp (N, Etype (It.Typ), Etype (It.Typ));
1863 Get_Next_Interp (I, It);
1867 -- A value of remote access-to-class-wide must not be dereferenced
1870 Validate_Remote_Access_To_Class_Wide_Type (N);
1871 end Analyze_Explicit_Dereference;
1873 ------------------------
1874 -- Analyze_Expression --
1875 ------------------------
1877 procedure Analyze_Expression (N : Node_Id) is
1880 Check_Parameterless_Call (N);
1881 end Analyze_Expression;
1883 -------------------------------------
1884 -- Analyze_Expression_With_Actions --
1885 -------------------------------------
1887 procedure Analyze_Expression_With_Actions (N : Node_Id) is
1891 A := First (Actions (N));
1898 Analyze_Expression (Expression (N));
1899 Set_Etype (N, Etype (Expression (N)));
1900 end Analyze_Expression_With_Actions;
1902 ------------------------------------
1903 -- Analyze_Indexed_Component_Form --
1904 ------------------------------------
1906 procedure Analyze_Indexed_Component_Form (N : Node_Id) is
1907 P : constant Node_Id := Prefix (N);
1908 Exprs : constant List_Id := Expressions (N);
1914 procedure Process_Function_Call;
1915 -- Prefix in indexed component form is an overloadable entity,
1916 -- so the node is a function call. Reformat it as such.
1918 procedure Process_Indexed_Component;
1919 -- Prefix in indexed component form is actually an indexed component.
1920 -- This routine processes it, knowing that the prefix is already
1923 procedure Process_Indexed_Component_Or_Slice;
1924 -- An indexed component with a single index may designate a slice if
1925 -- the index is a subtype mark. This routine disambiguates these two
1926 -- cases by resolving the prefix to see if it is a subtype mark.
1928 procedure Process_Overloaded_Indexed_Component;
1929 -- If the prefix of an indexed component is overloaded, the proper
1930 -- interpretation is selected by the index types and the context.
1932 ---------------------------
1933 -- Process_Function_Call --
1934 ---------------------------
1936 procedure Process_Function_Call is
1940 Change_Node (N, N_Function_Call);
1942 Set_Parameter_Associations (N, Exprs);
1944 -- Analyze actuals prior to analyzing the call itself
1946 Actual := First (Parameter_Associations (N));
1947 while Present (Actual) loop
1949 Check_Parameterless_Call (Actual);
1951 -- Move to next actual. Note that we use Next, not Next_Actual
1952 -- here. The reason for this is a bit subtle. If a function call
1953 -- includes named associations, the parser recognizes the node as
1954 -- a call, and it is analyzed as such. If all associations are
1955 -- positional, the parser builds an indexed_component node, and
1956 -- it is only after analysis of the prefix that the construct
1957 -- is recognized as a call, in which case Process_Function_Call
1958 -- rewrites the node and analyzes the actuals. If the list of
1959 -- actuals is malformed, the parser may leave the node as an
1960 -- indexed component (despite the presence of named associations).
1961 -- The iterator Next_Actual is equivalent to Next if the list is
1962 -- positional, but follows the normalized chain of actuals when
1963 -- named associations are present. In this case normalization has
1964 -- not taken place, and actuals remain unanalyzed, which leads to
1965 -- subsequent crashes or loops if there is an attempt to continue
1966 -- analysis of the program.
1972 end Process_Function_Call;
1974 -------------------------------
1975 -- Process_Indexed_Component --
1976 -------------------------------
1978 procedure Process_Indexed_Component is
1980 Array_Type : Entity_Id;
1982 Pent : Entity_Id := Empty;
1985 Exp := First (Exprs);
1987 if Is_Overloaded (P) then
1988 Process_Overloaded_Indexed_Component;
1991 Array_Type := Etype (P);
1993 if Is_Entity_Name (P) then
1995 elsif Nkind (P) = N_Selected_Component
1996 and then Is_Entity_Name (Selector_Name (P))
1998 Pent := Entity (Selector_Name (P));
2001 -- Prefix must be appropriate for an array type, taking into
2002 -- account a possible implicit dereference.
2004 if Is_Access_Type (Array_Type) then
2005 Error_Msg_NW (Warn_On_Dereference, "?implicit dereference", N);
2006 Array_Type := Process_Implicit_Dereference_Prefix (Pent, P);
2009 if Is_Array_Type (Array_Type) then
2012 elsif Present (Pent) and then Ekind (Pent) = E_Entry_Family then
2014 Set_Etype (N, Any_Type);
2016 if not Has_Compatible_Type
2017 (Exp, Entry_Index_Type (Pent))
2019 Error_Msg_N ("invalid index type in entry name", N);
2021 elsif Present (Next (Exp)) then
2022 Error_Msg_N ("too many subscripts in entry reference", N);
2025 Set_Etype (N, Etype (P));
2030 elsif Is_Record_Type (Array_Type)
2031 and then Remote_AST_I_Dereference (P)
2035 elsif Array_Type = Any_Type then
2036 Set_Etype (N, Any_Type);
2038 -- In most cases the analysis of the prefix will have emitted
2039 -- an error already, but if the prefix may be interpreted as a
2040 -- call in prefixed notation, the report is left to the caller.
2041 -- To prevent cascaded errors, report only if no previous ones.
2043 if Serious_Errors_Detected = 0 then
2044 Error_Msg_N ("invalid prefix in indexed component", P);
2046 if Nkind (P) = N_Expanded_Name then
2047 Error_Msg_NE ("\& is not visible", P, Selector_Name (P));
2053 -- Here we definitely have a bad indexing
2056 if Nkind (Parent (N)) = N_Requeue_Statement
2057 and then Present (Pent) and then Ekind (Pent) = E_Entry
2060 ("REQUEUE does not permit parameters", First (Exprs));
2062 elsif Is_Entity_Name (P)
2063 and then Etype (P) = Standard_Void_Type
2065 Error_Msg_NE ("incorrect use of&", P, Entity (P));
2068 Error_Msg_N ("array type required in indexed component", P);
2071 Set_Etype (N, Any_Type);
2075 Index := First_Index (Array_Type);
2076 while Present (Index) and then Present (Exp) loop
2077 if not Has_Compatible_Type (Exp, Etype (Index)) then
2078 Wrong_Type (Exp, Etype (Index));
2079 Set_Etype (N, Any_Type);
2087 Set_Etype (N, Component_Type (Array_Type));
2088 Check_Implicit_Dereference (N, Etype (N));
2090 if Present (Index) then
2092 ("too few subscripts in array reference", First (Exprs));
2094 elsif Present (Exp) then
2095 Error_Msg_N ("too many subscripts in array reference", Exp);
2098 end Process_Indexed_Component;
2100 ----------------------------------------
2101 -- Process_Indexed_Component_Or_Slice --
2102 ----------------------------------------
2104 procedure Process_Indexed_Component_Or_Slice is
2106 Exp := First (Exprs);
2107 while Present (Exp) loop
2108 Analyze_Expression (Exp);
2112 Exp := First (Exprs);
2114 -- If one index is present, and it is a subtype name, then the
2115 -- node denotes a slice (note that the case of an explicit range
2116 -- for a slice was already built as an N_Slice node in the first
2117 -- place, so that case is not handled here).
2119 -- We use a replace rather than a rewrite here because this is one
2120 -- of the cases in which the tree built by the parser is plain wrong.
2123 and then Is_Entity_Name (Exp)
2124 and then Is_Type (Entity (Exp))
2127 Make_Slice (Sloc (N),
2129 Discrete_Range => New_Copy (Exp)));
2132 -- Otherwise (more than one index present, or single index is not
2133 -- a subtype name), then we have the indexed component case.
2136 Process_Indexed_Component;
2138 end Process_Indexed_Component_Or_Slice;
2140 ------------------------------------------
2141 -- Process_Overloaded_Indexed_Component --
2142 ------------------------------------------
2144 procedure Process_Overloaded_Indexed_Component is
2153 Set_Etype (N, Any_Type);
2155 Get_First_Interp (P, I, It);
2156 while Present (It.Nam) loop
2159 if Is_Access_Type (Typ) then
2160 Typ := Designated_Type (Typ);
2161 Error_Msg_NW (Warn_On_Dereference, "?implicit dereference", N);
2164 if Is_Array_Type (Typ) then
2166 -- Got a candidate: verify that index types are compatible
2168 Index := First_Index (Typ);
2170 Exp := First (Exprs);
2171 while Present (Index) and then Present (Exp) loop
2172 if Has_Compatible_Type (Exp, Etype (Index)) then
2184 if Found and then No (Index) and then No (Exp) then
2186 CT : constant Entity_Id :=
2187 Base_Type (Component_Type (Typ));
2189 Add_One_Interp (N, CT, CT);
2190 Check_Implicit_Dereference (N, CT);
2195 Get_Next_Interp (I, It);
2198 if Etype (N) = Any_Type then
2199 Error_Msg_N ("no legal interpretation for indexed component", N);
2200 Set_Is_Overloaded (N, False);
2204 end Process_Overloaded_Indexed_Component;
2206 -- Start of processing for Analyze_Indexed_Component_Form
2209 -- Get name of array, function or type
2213 if Nkind_In (N, N_Function_Call, N_Procedure_Call_Statement) then
2215 -- If P is an explicit dereference whose prefix is of a
2216 -- remote access-to-subprogram type, then N has already
2217 -- been rewritten as a subprogram call and analyzed.
2222 pragma Assert (Nkind (N) = N_Indexed_Component);
2224 P_T := Base_Type (Etype (P));
2226 if Is_Entity_Name (P) and then Present (Entity (P)) then
2229 if Is_Type (U_N) then
2231 -- Reformat node as a type conversion
2233 E := Remove_Head (Exprs);
2235 if Present (First (Exprs)) then
2237 ("argument of type conversion must be single expression", N);
2240 Change_Node (N, N_Type_Conversion);
2241 Set_Subtype_Mark (N, P);
2243 Set_Expression (N, E);
2245 -- After changing the node, call for the specific Analysis
2246 -- routine directly, to avoid a double call to the expander.
2248 Analyze_Type_Conversion (N);
2252 if Is_Overloadable (U_N) then
2253 Process_Function_Call;
2255 elsif Ekind (Etype (P)) = E_Subprogram_Type
2256 or else (Is_Access_Type (Etype (P))
2258 Ekind (Designated_Type (Etype (P))) =
2261 -- Call to access_to-subprogram with possible implicit dereference
2263 Process_Function_Call;
2265 elsif Is_Generic_Subprogram (U_N) then
2267 -- A common beginner's (or C++ templates fan) error
2269 Error_Msg_N ("generic subprogram cannot be called", N);
2270 Set_Etype (N, Any_Type);
2274 Process_Indexed_Component_Or_Slice;
2277 -- If not an entity name, prefix is an expression that may denote
2278 -- an array or an access-to-subprogram.
2281 if Ekind (P_T) = E_Subprogram_Type
2282 or else (Is_Access_Type (P_T)
2284 Ekind (Designated_Type (P_T)) = E_Subprogram_Type)
2286 Process_Function_Call;
2288 elsif Nkind (P) = N_Selected_Component
2289 and then Is_Overloadable (Entity (Selector_Name (P)))
2291 Process_Function_Call;
2294 -- Indexed component, slice, or a call to a member of a family
2295 -- entry, which will be converted to an entry call later.
2297 Process_Indexed_Component_Or_Slice;
2300 end Analyze_Indexed_Component_Form;
2302 ------------------------
2303 -- Analyze_Logical_Op --
2304 ------------------------
2306 procedure Analyze_Logical_Op (N : Node_Id) is
2307 L : constant Node_Id := Left_Opnd (N);
2308 R : constant Node_Id := Right_Opnd (N);
2309 Op_Id : Entity_Id := Entity (N);
2312 Set_Etype (N, Any_Type);
2313 Candidate_Type := Empty;
2315 Analyze_Expression (L);
2316 Analyze_Expression (R);
2318 if Present (Op_Id) then
2320 if Ekind (Op_Id) = E_Operator then
2321 Find_Boolean_Types (L, R, Op_Id, N);
2323 Add_One_Interp (N, Op_Id, Etype (Op_Id));
2327 Op_Id := Get_Name_Entity_Id (Chars (N));
2328 while Present (Op_Id) loop
2329 if Ekind (Op_Id) = E_Operator then
2330 Find_Boolean_Types (L, R, Op_Id, N);
2332 Analyze_User_Defined_Binary_Op (N, Op_Id);
2335 Op_Id := Homonym (Op_Id);
2340 end Analyze_Logical_Op;
2342 ---------------------------
2343 -- Analyze_Membership_Op --
2344 ---------------------------
2346 procedure Analyze_Membership_Op (N : Node_Id) is
2347 Loc : constant Source_Ptr := Sloc (N);
2348 L : constant Node_Id := Left_Opnd (N);
2349 R : constant Node_Id := Right_Opnd (N);
2351 Index : Interp_Index;
2353 Found : Boolean := False;
2357 procedure Try_One_Interp (T1 : Entity_Id);
2358 -- Routine to try one proposed interpretation. Note that the context
2359 -- of the operation plays no role in resolving the arguments, so that
2360 -- if there is more than one interpretation of the operands that is
2361 -- compatible with a membership test, the operation is ambiguous.
2363 --------------------
2364 -- Try_One_Interp --
2365 --------------------
2367 procedure Try_One_Interp (T1 : Entity_Id) is
2369 if Has_Compatible_Type (R, T1) then
2371 and then Base_Type (T1) /= Base_Type (T_F)
2373 It := Disambiguate (L, I_F, Index, Any_Type);
2375 if It = No_Interp then
2376 Ambiguous_Operands (N);
2377 Set_Etype (L, Any_Type);
2394 procedure Analyze_Set_Membership;
2395 -- If a set of alternatives is present, analyze each and find the
2396 -- common type to which they must all resolve.
2398 ----------------------------
2399 -- Analyze_Set_Membership --
2400 ----------------------------
2402 procedure Analyze_Set_Membership is
2404 Index : Interp_Index;
2406 Candidate_Interps : Node_Id;
2407 Common_Type : Entity_Id := Empty;
2411 Candidate_Interps := L;
2413 if not Is_Overloaded (L) then
2414 Common_Type := Etype (L);
2416 Alt := First (Alternatives (N));
2417 while Present (Alt) loop
2420 if not Has_Compatible_Type (Alt, Common_Type) then
2421 Wrong_Type (Alt, Common_Type);
2428 Alt := First (Alternatives (N));
2429 while Present (Alt) loop
2431 if not Is_Overloaded (Alt) then
2432 Common_Type := Etype (Alt);
2435 Get_First_Interp (Alt, Index, It);
2436 while Present (It.Typ) loop
2438 Has_Compatible_Type (Candidate_Interps, It.Typ)
2440 Remove_Interp (Index);
2443 Get_Next_Interp (Index, It);
2446 Get_First_Interp (Alt, Index, It);
2449 Error_Msg_N ("alternative has no legal type", Alt);
2453 -- If alternative is not overloaded, we have a unique type
2456 Set_Etype (Alt, It.Typ);
2457 Get_Next_Interp (Index, It);
2460 Set_Is_Overloaded (Alt, False);
2461 Common_Type := Etype (Alt);
2464 Candidate_Interps := Alt;
2471 Set_Etype (N, Standard_Boolean);
2473 if Present (Common_Type) then
2474 Set_Etype (L, Common_Type);
2475 Set_Is_Overloaded (L, False);
2478 Error_Msg_N ("cannot resolve membership operation", N);
2480 end Analyze_Set_Membership;
2482 -- Start of processing for Analyze_Membership_Op
2485 Analyze_Expression (L);
2488 and then Ada_Version >= Ada_2012
2490 Analyze_Set_Membership;
2494 if Nkind (R) = N_Range
2495 or else (Nkind (R) = N_Attribute_Reference
2496 and then Attribute_Name (R) = Name_Range)
2500 if not Is_Overloaded (L) then
2501 Try_One_Interp (Etype (L));
2504 Get_First_Interp (L, Index, It);
2505 while Present (It.Typ) loop
2506 Try_One_Interp (It.Typ);
2507 Get_Next_Interp (Index, It);
2511 -- If not a range, it can be a subtype mark, or else it is a degenerate
2512 -- membership test with a singleton value, i.e. a test for equality,
2513 -- if the types are compatible.
2518 if Is_Entity_Name (R)
2519 and then Is_Type (Entity (R))
2522 Check_Fully_Declared (Entity (R), R);
2524 elsif Ada_Version >= Ada_2012
2525 and then Has_Compatible_Type (R, Etype (L))
2527 if Nkind (N) = N_In then
2543 -- In all versions of the language, if we reach this point there
2544 -- is a previous error that will be diagnosed below.
2550 -- Compatibility between expression and subtype mark or range is
2551 -- checked during resolution. The result of the operation is Boolean
2554 Set_Etype (N, Standard_Boolean);
2556 if Comes_From_Source (N)
2557 and then Present (Right_Opnd (N))
2558 and then Is_CPP_Class (Etype (Etype (Right_Opnd (N))))
2560 Error_Msg_N ("membership test not applicable to cpp-class types", N);
2562 end Analyze_Membership_Op;
2564 ----------------------
2565 -- Analyze_Negation --
2566 ----------------------
2568 procedure Analyze_Negation (N : Node_Id) is
2569 R : constant Node_Id := Right_Opnd (N);
2570 Op_Id : Entity_Id := Entity (N);
2573 Set_Etype (N, Any_Type);
2574 Candidate_Type := Empty;
2576 Analyze_Expression (R);
2578 if Present (Op_Id) then
2579 if Ekind (Op_Id) = E_Operator then
2580 Find_Negation_Types (R, Op_Id, N);
2582 Add_One_Interp (N, Op_Id, Etype (Op_Id));
2586 Op_Id := Get_Name_Entity_Id (Chars (N));
2587 while Present (Op_Id) loop
2588 if Ekind (Op_Id) = E_Operator then
2589 Find_Negation_Types (R, Op_Id, N);
2591 Analyze_User_Defined_Unary_Op (N, Op_Id);
2594 Op_Id := Homonym (Op_Id);
2599 end Analyze_Negation;
2605 procedure Analyze_Null (N : Node_Id) is
2607 Check_SPARK_Restriction ("null is not allowed", N);
2609 Set_Etype (N, Any_Access);
2612 ----------------------
2613 -- Analyze_One_Call --
2614 ----------------------
2616 procedure Analyze_One_Call
2620 Success : out Boolean;
2621 Skip_First : Boolean := False)
2623 Actuals : constant List_Id := Parameter_Associations (N);
2624 Prev_T : constant Entity_Id := Etype (N);
2626 Must_Skip : constant Boolean := Skip_First
2627 or else Nkind (Original_Node (N)) = N_Selected_Component
2629 (Nkind (Original_Node (N)) = N_Indexed_Component
2630 and then Nkind (Prefix (Original_Node (N)))
2631 = N_Selected_Component);
2632 -- The first formal must be omitted from the match when trying to find
2633 -- a primitive operation that is a possible interpretation, and also
2634 -- after the call has been rewritten, because the corresponding actual
2635 -- is already known to be compatible, and because this may be an
2636 -- indexing of a call with default parameters.
2640 Is_Indexed : Boolean := False;
2641 Is_Indirect : Boolean := False;
2642 Subp_Type : constant Entity_Id := Etype (Nam);
2645 function Operator_Hidden_By (Fun : Entity_Id) return Boolean;
2646 -- There may be a user-defined operator that hides the current
2647 -- interpretation. We must check for this independently of the
2648 -- analysis of the call with the user-defined operation, because
2649 -- the parameter names may be wrong and yet the hiding takes place.
2650 -- This fixes a problem with ACATS test B34014O.
2652 -- When the type Address is a visible integer type, and the DEC
2653 -- system extension is visible, the predefined operator may be
2654 -- hidden as well, by one of the address operations in auxdec.
2655 -- Finally, The abstract operations on address do not hide the
2656 -- predefined operator (this is the purpose of making them abstract).
2658 procedure Indicate_Name_And_Type;
2659 -- If candidate interpretation matches, indicate name and type of
2660 -- result on call node.
2662 ----------------------------
2663 -- Indicate_Name_And_Type --
2664 ----------------------------
2666 procedure Indicate_Name_And_Type is
2668 Add_One_Interp (N, Nam, Etype (Nam));
2669 Check_Implicit_Dereference (N, Etype (Nam));
2672 -- If the prefix of the call is a name, indicate the entity
2673 -- being called. If it is not a name, it is an expression that
2674 -- denotes an access to subprogram or else an entry or family. In
2675 -- the latter case, the name is a selected component, and the entity
2676 -- being called is noted on the selector.
2678 if not Is_Type (Nam) then
2679 if Is_Entity_Name (Name (N)) then
2680 Set_Entity (Name (N), Nam);
2682 elsif Nkind (Name (N)) = N_Selected_Component then
2683 Set_Entity (Selector_Name (Name (N)), Nam);
2687 if Debug_Flag_E and not Report then
2688 Write_Str (" Overloaded call ");
2689 Write_Int (Int (N));
2690 Write_Str (" compatible with ");
2691 Write_Int (Int (Nam));
2694 end Indicate_Name_And_Type;
2696 ------------------------
2697 -- Operator_Hidden_By --
2698 ------------------------
2700 function Operator_Hidden_By (Fun : Entity_Id) return Boolean is
2701 Act1 : constant Node_Id := First_Actual (N);
2702 Act2 : constant Node_Id := Next_Actual (Act1);
2703 Form1 : constant Entity_Id := First_Formal (Fun);
2704 Form2 : constant Entity_Id := Next_Formal (Form1);
2707 if Ekind (Fun) /= E_Function
2708 or else Is_Abstract_Subprogram (Fun)
2712 elsif not Has_Compatible_Type (Act1, Etype (Form1)) then
2715 elsif Present (Form2) then
2717 No (Act2) or else not Has_Compatible_Type (Act2, Etype (Form2))
2722 elsif Present (Act2) then
2726 -- Now we know that the arity of the operator matches the function,
2727 -- and the function call is a valid interpretation. The function
2728 -- hides the operator if it has the right signature, or if one of
2729 -- its operands is a non-abstract operation on Address when this is
2730 -- a visible integer type.
2732 return Hides_Op (Fun, Nam)
2733 or else Is_Descendent_Of_Address (Etype (Form1))
2736 and then Is_Descendent_Of_Address (Etype (Form2)));
2737 end Operator_Hidden_By;
2739 -- Start of processing for Analyze_One_Call
2744 -- If the subprogram has no formals or if all the formals have defaults,
2745 -- and the return type is an array type, the node may denote an indexing
2746 -- of the result of a parameterless call. In Ada 2005, the subprogram
2747 -- may have one non-defaulted formal, and the call may have been written
2748 -- in prefix notation, so that the rebuilt parameter list has more than
2751 if not Is_Overloadable (Nam)
2752 and then Ekind (Nam) /= E_Subprogram_Type
2753 and then Ekind (Nam) /= E_Entry_Family
2758 -- An indexing requires at least one actual
2760 if not Is_Empty_List (Actuals)
2762 (Needs_No_Actuals (Nam)
2764 (Needs_One_Actual (Nam)
2765 and then Present (Next_Actual (First (Actuals)))))
2767 if Is_Array_Type (Subp_Type) then
2768 Is_Indexed := Try_Indexed_Call (N, Nam, Subp_Type, Must_Skip);
2770 elsif Is_Access_Type (Subp_Type)
2771 and then Is_Array_Type (Designated_Type (Subp_Type))
2775 (N, Nam, Designated_Type (Subp_Type), Must_Skip);
2777 -- The prefix can also be a parameterless function that returns an
2778 -- access to subprogram, in which case this is an indirect call.
2779 -- If this succeeds, an explicit dereference is added later on,
2780 -- in Analyze_Call or Resolve_Call.
2782 elsif Is_Access_Type (Subp_Type)
2783 and then Ekind (Designated_Type (Subp_Type)) = E_Subprogram_Type
2785 Is_Indirect := Try_Indirect_Call (N, Nam, Subp_Type);
2790 -- If the call has been transformed into a slice, it is of the form
2791 -- F (Subtype) where F is parameterless. The node has been rewritten in
2792 -- Try_Indexed_Call and there is nothing else to do.
2795 and then Nkind (N) = N_Slice
2801 (N, Nam, (Report and not Is_Indexed and not Is_Indirect), Norm_OK);
2805 -- If an indirect call is a possible interpretation, indicate
2806 -- success to the caller.
2812 -- Mismatch in number or names of parameters
2814 elsif Debug_Flag_E then
2815 Write_Str (" normalization fails in call ");
2816 Write_Int (Int (N));
2817 Write_Str (" with subprogram ");
2818 Write_Int (Int (Nam));
2822 -- If the context expects a function call, discard any interpretation
2823 -- that is a procedure. If the node is not overloaded, leave as is for
2824 -- better error reporting when type mismatch is found.
2826 elsif Nkind (N) = N_Function_Call
2827 and then Is_Overloaded (Name (N))
2828 and then Ekind (Nam) = E_Procedure
2832 -- Ditto for function calls in a procedure context
2834 elsif Nkind (N) = N_Procedure_Call_Statement
2835 and then Is_Overloaded (Name (N))
2836 and then Etype (Nam) /= Standard_Void_Type
2840 elsif No (Actuals) then
2842 -- If Normalize succeeds, then there are default parameters for
2845 Indicate_Name_And_Type;
2847 elsif Ekind (Nam) = E_Operator then
2848 if Nkind (N) = N_Procedure_Call_Statement then
2852 -- This can occur when the prefix of the call is an operator
2853 -- name or an expanded name whose selector is an operator name.
2855 Analyze_Operator_Call (N, Nam);
2857 if Etype (N) /= Prev_T then
2859 -- Check that operator is not hidden by a function interpretation
2861 if Is_Overloaded (Name (N)) then
2867 Get_First_Interp (Name (N), I, It);
2868 while Present (It.Nam) loop
2869 if Operator_Hidden_By (It.Nam) then
2870 Set_Etype (N, Prev_T);
2874 Get_Next_Interp (I, It);
2879 -- If operator matches formals, record its name on the call.
2880 -- If the operator is overloaded, Resolve will select the
2881 -- correct one from the list of interpretations. The call
2882 -- node itself carries the first candidate.
2884 Set_Entity (Name (N), Nam);
2887 elsif Report and then Etype (N) = Any_Type then
2888 Error_Msg_N ("incompatible arguments for operator", N);
2892 -- Normalize_Actuals has chained the named associations in the
2893 -- correct order of the formals.
2895 Actual := First_Actual (N);
2896 Formal := First_Formal (Nam);
2898 -- If we are analyzing a call rewritten from object notation, skip
2899 -- first actual, which may be rewritten later as an explicit
2903 Next_Actual (Actual);
2904 Next_Formal (Formal);
2907 while Present (Actual) and then Present (Formal) loop
2908 if Nkind (Parent (Actual)) /= N_Parameter_Association
2909 or else Chars (Selector_Name (Parent (Actual))) = Chars (Formal)
2911 -- The actual can be compatible with the formal, but we must
2912 -- also check that the context is not an address type that is
2913 -- visibly an integer type, as is the case in VMS_64. In this
2914 -- case the use of literals is illegal, except in the body of
2915 -- descendents of system, where arithmetic operations on
2916 -- address are of course used.
2918 if Has_Compatible_Type (Actual, Etype (Formal))
2920 (Etype (Actual) /= Universal_Integer
2921 or else not Is_Descendent_Of_Address (Etype (Formal))
2923 Is_Predefined_File_Name
2924 (Unit_File_Name (Get_Source_Unit (N))))
2926 Next_Actual (Actual);
2927 Next_Formal (Formal);
2930 if Debug_Flag_E then
2931 Write_Str (" type checking fails in call ");
2932 Write_Int (Int (N));
2933 Write_Str (" with formal ");
2934 Write_Int (Int (Formal));
2935 Write_Str (" in subprogram ");
2936 Write_Int (Int (Nam));
2940 if Report and not Is_Indexed and not Is_Indirect then
2942 -- Ada 2005 (AI-251): Complete the error notification
2943 -- to help new Ada 2005 users.
2945 if Is_Class_Wide_Type (Etype (Formal))
2946 and then Is_Interface (Etype (Etype (Formal)))
2947 and then not Interface_Present_In_Ancestor
2948 (Typ => Etype (Actual),
2949 Iface => Etype (Etype (Formal)))
2952 ("(Ada 2005) does not implement interface }",
2953 Actual, Etype (Etype (Formal)));
2956 Wrong_Type (Actual, Etype (Formal));
2958 if Nkind (Actual) = N_Op_Eq
2959 and then Nkind (Left_Opnd (Actual)) = N_Identifier
2961 Formal := First_Formal (Nam);
2962 while Present (Formal) loop
2963 if Chars (Left_Opnd (Actual)) = Chars (Formal) then
2964 Error_Msg_N -- CODEFIX
2965 ("possible misspelling of `='>`!", Actual);
2969 Next_Formal (Formal);
2973 if All_Errors_Mode then
2974 Error_Msg_Sloc := Sloc (Nam);
2976 if Etype (Formal) = Any_Type then
2978 ("there is no legal actual parameter", Actual);
2981 if Is_Overloadable (Nam)
2982 and then Present (Alias (Nam))
2983 and then not Comes_From_Source (Nam)
2986 ("\\ =='> in call to inherited operation & #!",
2989 elsif Ekind (Nam) = E_Subprogram_Type then
2991 Access_To_Subprogram_Typ :
2992 constant Entity_Id :=
2994 (Associated_Node_For_Itype (Nam));
2997 "\\ =='> in call to dereference of &#!",
2998 Actual, Access_To_Subprogram_Typ);
3003 ("\\ =='> in call to &#!", Actual, Nam);
3013 -- Normalize_Actuals has verified that a default value exists
3014 -- for this formal. Current actual names a subsequent formal.
3016 Next_Formal (Formal);
3020 -- On exit, all actuals match
3022 Indicate_Name_And_Type;
3024 end Analyze_One_Call;
3026 ---------------------------
3027 -- Analyze_Operator_Call --
3028 ---------------------------
3030 procedure Analyze_Operator_Call (N : Node_Id; Op_Id : Entity_Id) is
3031 Op_Name : constant Name_Id := Chars (Op_Id);
3032 Act1 : constant Node_Id := First_Actual (N);
3033 Act2 : constant Node_Id := Next_Actual (Act1);
3036 -- Binary operator case
3038 if Present (Act2) then
3040 -- If more than two operands, then not binary operator after all
3042 if Present (Next_Actual (Act2)) then
3045 elsif Op_Name = Name_Op_Add
3046 or else Op_Name = Name_Op_Subtract
3047 or else Op_Name = Name_Op_Multiply
3048 or else Op_Name = Name_Op_Divide
3049 or else Op_Name = Name_Op_Mod
3050 or else Op_Name = Name_Op_Rem
3051 or else Op_Name = Name_Op_Expon
3053 Find_Arithmetic_Types (Act1, Act2, Op_Id, N);
3055 elsif Op_Name = Name_Op_And
3056 or else Op_Name = Name_Op_Or
3057 or else Op_Name = Name_Op_Xor
3059 Find_Boolean_Types (Act1, Act2, Op_Id, N);
3061 elsif Op_Name = Name_Op_Lt
3062 or else Op_Name = Name_Op_Le
3063 or else Op_Name = Name_Op_Gt
3064 or else Op_Name = Name_Op_Ge
3066 Find_Comparison_Types (Act1, Act2, Op_Id, N);
3068 elsif Op_Name = Name_Op_Eq
3069 or else Op_Name = Name_Op_Ne
3071 Find_Equality_Types (Act1, Act2, Op_Id, N);
3073 elsif Op_Name = Name_Op_Concat then
3074 Find_Concatenation_Types (Act1, Act2, Op_Id, N);
3076 -- Is this else null correct, or should it be an abort???
3082 -- Unary operator case
3085 if Op_Name = Name_Op_Subtract or else
3086 Op_Name = Name_Op_Add or else
3087 Op_Name = Name_Op_Abs
3089 Find_Unary_Types (Act1, Op_Id, N);
3092 Op_Name = Name_Op_Not
3094 Find_Negation_Types (Act1, Op_Id, N);
3096 -- Is this else null correct, or should it be an abort???
3102 end Analyze_Operator_Call;
3104 -------------------------------------------
3105 -- Analyze_Overloaded_Selected_Component --
3106 -------------------------------------------
3108 procedure Analyze_Overloaded_Selected_Component (N : Node_Id) is
3109 Nam : constant Node_Id := Prefix (N);
3110 Sel : constant Node_Id := Selector_Name (N);
3117 Set_Etype (Sel, Any_Type);
3119 Get_First_Interp (Nam, I, It);
3120 while Present (It.Typ) loop
3121 if Is_Access_Type (It.Typ) then
3122 T := Designated_Type (It.Typ);
3123 Error_Msg_NW (Warn_On_Dereference, "?implicit dereference", N);
3128 -- Locate the component. For a private prefix the selector can denote
3131 if Is_Record_Type (T) or else Is_Private_Type (T) then
3133 -- If the prefix is a class-wide type, the visible components are
3134 -- those of the base type.
3136 if Is_Class_Wide_Type (T) then
3140 Comp := First_Entity (T);
3141 while Present (Comp) loop
3142 if Chars (Comp) = Chars (Sel)
3143 and then Is_Visible_Component (Comp)
3146 -- AI05-105: if the context is an object renaming with
3147 -- an anonymous access type, the expected type of the
3148 -- object must be anonymous. This is a name resolution rule.
3150 if Nkind (Parent (N)) /= N_Object_Renaming_Declaration
3151 or else No (Access_Definition (Parent (N)))
3152 or else Ekind (Etype (Comp)) = E_Anonymous_Access_Type
3154 Ekind (Etype (Comp)) = E_Anonymous_Access_Subprogram_Type
3156 Set_Entity (Sel, Comp);
3157 Set_Etype (Sel, Etype (Comp));
3158 Add_One_Interp (N, Etype (Comp), Etype (Comp));
3159 Check_Implicit_Dereference (N, Etype (Comp));
3161 -- This also specifies a candidate to resolve the name.
3162 -- Further overloading will be resolved from context.
3163 -- The selector name itself does not carry overloading
3166 Set_Etype (Nam, It.Typ);
3169 -- Named access type in the context of a renaming
3170 -- declaration with an access definition. Remove
3171 -- inapplicable candidate.
3180 elsif Is_Concurrent_Type (T) then
3181 Comp := First_Entity (T);
3182 while Present (Comp)
3183 and then Comp /= First_Private_Entity (T)
3185 if Chars (Comp) = Chars (Sel) then
3186 if Is_Overloadable (Comp) then
3187 Add_One_Interp (Sel, Comp, Etype (Comp));
3189 Set_Entity_With_Style_Check (Sel, Comp);
3190 Generate_Reference (Comp, Sel);
3193 Set_Etype (Sel, Etype (Comp));
3194 Set_Etype (N, Etype (Comp));
3195 Set_Etype (Nam, It.Typ);
3197 -- For access type case, introduce explicit dereference for
3198 -- more uniform treatment of entry calls. Do this only once
3199 -- if several interpretations yield an access type.
3201 if Is_Access_Type (Etype (Nam))
3202 and then Nkind (Nam) /= N_Explicit_Dereference
3204 Insert_Explicit_Dereference (Nam);
3206 (Warn_On_Dereference, "?implicit dereference", N);
3213 Set_Is_Overloaded (N, Is_Overloaded (Sel));
3216 Get_Next_Interp (I, It);
3219 if Etype (N) = Any_Type
3220 and then not Try_Object_Operation (N)
3222 Error_Msg_NE ("undefined selector& for overloaded prefix", N, Sel);
3223 Set_Entity (Sel, Any_Id);
3224 Set_Etype (Sel, Any_Type);
3226 end Analyze_Overloaded_Selected_Component;
3228 ----------------------------------
3229 -- Analyze_Qualified_Expression --
3230 ----------------------------------
3232 procedure Analyze_Qualified_Expression (N : Node_Id) is
3233 Mark : constant Entity_Id := Subtype_Mark (N);
3234 Expr : constant Node_Id := Expression (N);
3240 Analyze_Expression (Expr);
3242 Set_Etype (N, Any_Type);
3247 if T = Any_Type then
3251 Check_Fully_Declared (T, N);
3253 -- If expected type is class-wide, check for exact match before
3254 -- expansion, because if the expression is a dispatching call it
3255 -- may be rewritten as explicit dereference with class-wide result.
3256 -- If expression is overloaded, retain only interpretations that
3257 -- will yield exact matches.
3259 if Is_Class_Wide_Type (T) then
3260 if not Is_Overloaded (Expr) then
3261 if Base_Type (Etype (Expr)) /= Base_Type (T) then
3262 if Nkind (Expr) = N_Aggregate then
3263 Error_Msg_N ("type of aggregate cannot be class-wide", Expr);
3265 Wrong_Type (Expr, T);
3270 Get_First_Interp (Expr, I, It);
3272 while Present (It.Nam) loop
3273 if Base_Type (It.Typ) /= Base_Type (T) then
3277 Get_Next_Interp (I, It);
3283 end Analyze_Qualified_Expression;
3285 -----------------------------------
3286 -- Analyze_Quantified_Expression --
3287 -----------------------------------
3289 procedure Analyze_Quantified_Expression (N : Node_Id) is
3290 Loc : constant Source_Ptr := Sloc (N);
3291 Ent : constant Entity_Id :=
3293 (E_Loop, Current_Scope, Sloc (N), 'L');
3298 Check_SPARK_Restriction ("quantified expression is not allowed", N);
3300 Set_Etype (Ent, Standard_Void_Type);
3301 Set_Parent (Ent, N);
3303 if Present (Loop_Parameter_Specification (N)) then
3305 Make_Iteration_Scheme (Loc,
3306 Loop_Parameter_Specification =>
3307 Loop_Parameter_Specification (N));
3310 Make_Iteration_Scheme (Loc,
3311 Iterator_Specification =>
3312 Iterator_Specification (N));
3316 Set_Parent (Iterator, N);
3317 Analyze_Iteration_Scheme (Iterator);
3319 -- The loop specification may have been converted into an
3320 -- iterator specification during its analysis. Update the
3321 -- quantified node accordingly.
3323 if Present (Iterator_Specification (Iterator)) then
3324 Set_Iterator_Specification
3325 (N, Iterator_Specification (Iterator));
3326 Set_Loop_Parameter_Specification (N, Empty);
3329 Analyze (Condition (N));
3332 Set_Etype (N, Standard_Boolean);
3333 end Analyze_Quantified_Expression;
3339 procedure Analyze_Range (N : Node_Id) is
3340 L : constant Node_Id := Low_Bound (N);
3341 H : constant Node_Id := High_Bound (N);
3342 I1, I2 : Interp_Index;
3345 procedure Check_Common_Type (T1, T2 : Entity_Id);
3346 -- Verify the compatibility of two types, and choose the
3347 -- non universal one if the other is universal.
3349 procedure Check_High_Bound (T : Entity_Id);
3350 -- Test one interpretation of the low bound against all those
3351 -- of the high bound.
3353 procedure Check_Universal_Expression (N : Node_Id);
3354 -- In Ada83, reject bounds of a universal range that are not
3355 -- literals or entity names.
3357 -----------------------
3358 -- Check_Common_Type --
3359 -----------------------
3361 procedure Check_Common_Type (T1, T2 : Entity_Id) is
3363 if Covers (T1 => T1, T2 => T2)
3365 Covers (T1 => T2, T2 => T1)
3367 if T1 = Universal_Integer
3368 or else T1 = Universal_Real
3369 or else T1 = Any_Character
3371 Add_One_Interp (N, Base_Type (T2), Base_Type (T2));
3374 Add_One_Interp (N, T1, T1);
3377 Add_One_Interp (N, Base_Type (T1), Base_Type (T1));
3380 end Check_Common_Type;
3382 ----------------------
3383 -- Check_High_Bound --
3384 ----------------------
3386 procedure Check_High_Bound (T : Entity_Id) is
3388 if not Is_Overloaded (H) then
3389 Check_Common_Type (T, Etype (H));
3391 Get_First_Interp (H, I2, It2);
3392 while Present (It2.Typ) loop
3393 Check_Common_Type (T, It2.Typ);
3394 Get_Next_Interp (I2, It2);
3397 end Check_High_Bound;
3399 -----------------------------
3400 -- Is_Universal_Expression --
3401 -----------------------------
3403 procedure Check_Universal_Expression (N : Node_Id) is
3405 if Etype (N) = Universal_Integer
3406 and then Nkind (N) /= N_Integer_Literal
3407 and then not Is_Entity_Name (N)
3408 and then Nkind (N) /= N_Attribute_Reference
3410 Error_Msg_N ("illegal bound in discrete range", N);
3412 end Check_Universal_Expression;
3414 -- Start of processing for Analyze_Range
3417 Set_Etype (N, Any_Type);
3418 Analyze_Expression (L);
3419 Analyze_Expression (H);
3421 if Etype (L) = Any_Type or else Etype (H) = Any_Type then
3425 if not Is_Overloaded (L) then
3426 Check_High_Bound (Etype (L));
3428 Get_First_Interp (L, I1, It1);
3429 while Present (It1.Typ) loop
3430 Check_High_Bound (It1.Typ);
3431 Get_Next_Interp (I1, It1);
3435 -- If result is Any_Type, then we did not find a compatible pair
3437 if Etype (N) = Any_Type then
3438 Error_Msg_N ("incompatible types in range ", N);
3442 if Ada_Version = Ada_83
3444 (Nkind (Parent (N)) = N_Loop_Parameter_Specification
3445 or else Nkind (Parent (N)) = N_Constrained_Array_Definition)
3447 Check_Universal_Expression (L);
3448 Check_Universal_Expression (H);
3452 -----------------------
3453 -- Analyze_Reference --
3454 -----------------------
3456 procedure Analyze_Reference (N : Node_Id) is
3457 P : constant Node_Id := Prefix (N);
3460 Acc_Type : Entity_Id;
3465 -- An interesting error check, if we take the 'Reference of an object
3466 -- for which a pragma Atomic or Volatile has been given, and the type
3467 -- of the object is not Atomic or Volatile, then we are in trouble. The
3468 -- problem is that no trace of the atomic/volatile status will remain
3469 -- for the backend to respect when it deals with the resulting pointer,
3470 -- since the pointer type will not be marked atomic (it is a pointer to
3471 -- the base type of the object).
3473 -- It is not clear if that can ever occur, but in case it does, we will
3474 -- generate an error message. Not clear if this message can ever be
3475 -- generated, and pretty clear that it represents a bug if it is, still
3476 -- seems worth checking, except in CodePeer mode where we do not really
3477 -- care and don't want to bother the user.
3481 if Is_Entity_Name (P)
3482 and then Is_Object_Reference (P)
3483 and then not CodePeer_Mode
3488 if (Has_Atomic_Components (E)
3489 and then not Has_Atomic_Components (T))
3491 (Has_Volatile_Components (E)
3492 and then not Has_Volatile_Components (T))
3493 or else (Is_Atomic (E) and then not Is_Atomic (T))
3494 or else (Is_Volatile (E) and then not Is_Volatile (T))
3496 Error_Msg_N ("cannot take reference to Atomic/Volatile object", N);
3500 -- Carry on with normal processing
3502 Acc_Type := Create_Itype (E_Allocator_Type, N);
3503 Set_Etype (Acc_Type, Acc_Type);
3504 Set_Directly_Designated_Type (Acc_Type, Etype (P));
3505 Set_Etype (N, Acc_Type);
3506 end Analyze_Reference;
3508 --------------------------------
3509 -- Analyze_Selected_Component --
3510 --------------------------------
3512 -- Prefix is a record type or a task or protected type. In the latter case,
3513 -- the selector must denote a visible entry.
3515 procedure Analyze_Selected_Component (N : Node_Id) is
3516 Name : constant Node_Id := Prefix (N);
3517 Sel : constant Node_Id := Selector_Name (N);
3520 Has_Candidate : Boolean := False;
3523 Pent : Entity_Id := Empty;
3524 Prefix_Type : Entity_Id;
3526 Type_To_Use : Entity_Id;
3527 -- In most cases this is the Prefix_Type, but if the Prefix_Type is
3528 -- a class-wide type, we use its root type, whose components are
3529 -- present in the class-wide type.
3531 Is_Single_Concurrent_Object : Boolean;
3532 -- Set True if the prefix is a single task or a single protected object
3534 procedure Find_Component_In_Instance (Rec : Entity_Id);
3535 -- In an instance, a component of a private extension may not be visible
3536 -- while it was visible in the generic. Search candidate scope for a
3537 -- component with the proper identifier. This is only done if all other
3538 -- searches have failed. When the match is found (it always will be),
3539 -- the Etype of both N and Sel are set from this component, and the
3540 -- entity of Sel is set to reference this component.
3542 function Has_Mode_Conformant_Spec (Comp : Entity_Id) return Boolean;
3543 -- It is known that the parent of N denotes a subprogram call. Comp
3544 -- is an overloadable component of the concurrent type of the prefix.
3545 -- Determine whether all formals of the parent of N and Comp are mode
3546 -- conformant. If the parent node is not analyzed yet it may be an
3547 -- indexed component rather than a function call.
3549 --------------------------------
3550 -- Find_Component_In_Instance --
3551 --------------------------------
3553 procedure Find_Component_In_Instance (Rec : Entity_Id) is
3557 Comp := First_Component (Rec);
3558 while Present (Comp) loop
3559 if Chars (Comp) = Chars (Sel) then
3560 Set_Entity_With_Style_Check (Sel, Comp);
3561 Set_Etype (Sel, Etype (Comp));
3562 Set_Etype (N, Etype (Comp));
3566 Next_Component (Comp);
3569 -- This must succeed because code was legal in the generic
3571 raise Program_Error;
3572 end Find_Component_In_Instance;
3574 ------------------------------
3575 -- Has_Mode_Conformant_Spec --
3576 ------------------------------
3578 function Has_Mode_Conformant_Spec (Comp : Entity_Id) return Boolean is
3579 Comp_Param : Entity_Id;
3581 Param_Typ : Entity_Id;
3584 Comp_Param := First_Formal (Comp);
3586 if Nkind (Parent (N)) = N_Indexed_Component then
3587 Param := First (Expressions (Parent (N)));
3589 Param := First (Parameter_Associations (Parent (N)));
3592 while Present (Comp_Param)
3593 and then Present (Param)
3595 Param_Typ := Find_Parameter_Type (Param);
3597 if Present (Param_Typ)
3599 not Conforming_Types
3600 (Etype (Comp_Param), Param_Typ, Mode_Conformant)
3605 Next_Formal (Comp_Param);
3609 -- One of the specs has additional formals
3611 if Present (Comp_Param) or else Present (Param) then
3616 end Has_Mode_Conformant_Spec;
3618 -- Start of processing for Analyze_Selected_Component
3621 Set_Etype (N, Any_Type);
3623 if Is_Overloaded (Name) then
3624 Analyze_Overloaded_Selected_Component (N);
3627 elsif Etype (Name) = Any_Type then
3628 Set_Entity (Sel, Any_Id);
3629 Set_Etype (Sel, Any_Type);
3633 Prefix_Type := Etype (Name);
3636 if Is_Access_Type (Prefix_Type) then
3638 -- A RACW object can never be used as prefix of a selected component
3639 -- since that means it is dereferenced without being a controlling
3640 -- operand of a dispatching operation (RM E.2.2(16/1)). Before
3641 -- reporting an error, we must check whether this is actually a
3642 -- dispatching call in prefix form.
3644 if Is_Remote_Access_To_Class_Wide_Type (Prefix_Type)
3645 and then Comes_From_Source (N)
3647 if Try_Object_Operation (N) then
3651 ("invalid dereference of a remote access-to-class-wide value",
3655 -- Normal case of selected component applied to access type
3658 Error_Msg_NW (Warn_On_Dereference, "?implicit dereference", N);
3660 if Is_Entity_Name (Name) then
3661 Pent := Entity (Name);
3662 elsif Nkind (Name) = N_Selected_Component
3663 and then Is_Entity_Name (Selector_Name (Name))
3665 Pent := Entity (Selector_Name (Name));
3668 Prefix_Type := Process_Implicit_Dereference_Prefix (Pent, Name);
3671 -- If we have an explicit dereference of a remote access-to-class-wide
3672 -- value, then issue an error (see RM-E.2.2(16/1)). However we first
3673 -- have to check for the case of a prefix that is a controlling operand
3674 -- of a prefixed dispatching call, as the dereference is legal in that
3675 -- case. Normally this condition is checked in Validate_Remote_Access_
3676 -- To_Class_Wide_Type, but we have to defer the checking for selected
3677 -- component prefixes because of the prefixed dispatching call case.
3678 -- Note that implicit dereferences are checked for this just above.
3680 elsif Nkind (Name) = N_Explicit_Dereference
3681 and then Is_Remote_Access_To_Class_Wide_Type (Etype (Prefix (Name)))
3682 and then Comes_From_Source (N)
3684 if Try_Object_Operation (N) then
3688 ("invalid dereference of a remote access-to-class-wide value",
3693 -- (Ada 2005): if the prefix is the limited view of a type, and
3694 -- the context already includes the full view, use the full view
3695 -- in what follows, either to retrieve a component of to find
3696 -- a primitive operation. If the prefix is an explicit dereference,
3697 -- set the type of the prefix to reflect this transformation.
3698 -- If the non-limited view is itself an incomplete type, get the
3699 -- full view if available.
3701 if Is_Incomplete_Type (Prefix_Type)
3702 and then From_With_Type (Prefix_Type)
3703 and then Present (Non_Limited_View (Prefix_Type))
3705 Prefix_Type := Get_Full_View (Non_Limited_View (Prefix_Type));
3707 if Nkind (N) = N_Explicit_Dereference then
3708 Set_Etype (Prefix (N), Prefix_Type);
3711 elsif Ekind (Prefix_Type) = E_Class_Wide_Type
3712 and then From_With_Type (Prefix_Type)
3713 and then Present (Non_Limited_View (Etype (Prefix_Type)))
3716 Class_Wide_Type (Non_Limited_View (Etype (Prefix_Type)));
3718 if Nkind (N) = N_Explicit_Dereference then
3719 Set_Etype (Prefix (N), Prefix_Type);
3723 if Ekind (Prefix_Type) = E_Private_Subtype then
3724 Prefix_Type := Base_Type (Prefix_Type);
3727 Type_To_Use := Prefix_Type;
3729 -- For class-wide types, use the entity list of the root type. This
3730 -- indirection is specially important for private extensions because
3731 -- only the root type get switched (not the class-wide type).
3733 if Is_Class_Wide_Type (Prefix_Type) then
3734 Type_To_Use := Root_Type (Prefix_Type);
3737 -- If the prefix is a single concurrent object, use its name in error
3738 -- messages, rather than that of its anonymous type.
3740 Is_Single_Concurrent_Object :=
3741 Is_Concurrent_Type (Prefix_Type)
3742 and then Is_Internal_Name (Chars (Prefix_Type))
3743 and then not Is_Derived_Type (Prefix_Type)
3744 and then Is_Entity_Name (Name);
3746 Comp := First_Entity (Type_To_Use);
3748 -- If the selector has an original discriminant, the node appears in
3749 -- an instance. Replace the discriminant with the corresponding one
3750 -- in the current discriminated type. For nested generics, this must
3751 -- be done transitively, so note the new original discriminant.
3753 if Nkind (Sel) = N_Identifier
3754 and then In_Instance
3755 and then Present (Original_Discriminant (Sel))
3757 Comp := Find_Corresponding_Discriminant (Sel, Prefix_Type);
3759 -- Mark entity before rewriting, for completeness and because
3760 -- subsequent semantic checks might examine the original node.
3762 Set_Entity (Sel, Comp);
3763 Rewrite (Selector_Name (N),
3764 New_Occurrence_Of (Comp, Sloc (N)));
3765 Set_Original_Discriminant (Selector_Name (N), Comp);
3766 Set_Etype (N, Etype (Comp));
3767 Check_Implicit_Dereference (N, Etype (Comp));
3769 if Is_Access_Type (Etype (Name)) then
3770 Insert_Explicit_Dereference (Name);
3771 Error_Msg_NW (Warn_On_Dereference, "?implicit dereference", N);
3774 elsif Is_Record_Type (Prefix_Type) then
3776 -- Find component with given name
3778 while Present (Comp) loop
3779 if Chars (Comp) = Chars (Sel)
3780 and then Is_Visible_Component (Comp)
3782 Set_Entity_With_Style_Check (Sel, Comp);
3783 Set_Etype (Sel, Etype (Comp));
3785 if Ekind (Comp) = E_Discriminant then
3786 if Is_Unchecked_Union (Base_Type (Prefix_Type)) then
3788 ("cannot reference discriminant of Unchecked_Union",
3792 if Is_Generic_Type (Prefix_Type)
3794 Is_Generic_Type (Root_Type (Prefix_Type))
3796 Set_Original_Discriminant (Sel, Comp);
3800 -- Resolve the prefix early otherwise it is not possible to
3801 -- build the actual subtype of the component: it may need
3802 -- to duplicate this prefix and duplication is only allowed
3803 -- on fully resolved expressions.
3807 -- Ada 2005 (AI-50217): Check wrong use of incomplete types or
3808 -- subtypes in a package specification.
3811 -- limited with Pkg;
3813 -- type Acc_Inc is access Pkg.T;
3815 -- N : Natural := X.all.Comp; -- ERROR, limited view
3816 -- end Pkg; -- Comp is not visible
3818 if Nkind (Name) = N_Explicit_Dereference
3819 and then From_With_Type (Etype (Prefix (Name)))
3820 and then not Is_Potentially_Use_Visible (Etype (Name))
3821 and then Nkind (Parent (Cunit_Entity (Current_Sem_Unit))) =
3822 N_Package_Specification
3825 ("premature usage of incomplete}", Prefix (Name),
3826 Etype (Prefix (Name)));
3829 -- We never need an actual subtype for the case of a selection
3830 -- for a indexed component of a non-packed array, since in
3831 -- this case gigi generates all the checks and can find the
3832 -- necessary bounds information.
3834 -- We also do not need an actual subtype for the case of a
3835 -- first, last, length, or range attribute applied to a
3836 -- non-packed array, since gigi can again get the bounds in
3837 -- these cases (gigi cannot handle the packed case, since it
3838 -- has the bounds of the packed array type, not the original
3839 -- bounds of the type). However, if the prefix is itself a
3840 -- selected component, as in a.b.c (i), gigi may regard a.b.c
3841 -- as a dynamic-sized temporary, so we do generate an actual
3842 -- subtype for this case.
3844 Parent_N := Parent (N);
3846 if not Is_Packed (Etype (Comp))
3848 ((Nkind (Parent_N) = N_Indexed_Component
3849 and then Nkind (Name) /= N_Selected_Component)
3851 (Nkind (Parent_N) = N_Attribute_Reference
3852 and then (Attribute_Name (Parent_N) = Name_First
3854 Attribute_Name (Parent_N) = Name_Last
3856 Attribute_Name (Parent_N) = Name_Length
3858 Attribute_Name (Parent_N) = Name_Range)))
3860 Set_Etype (N, Etype (Comp));
3862 -- If full analysis is not enabled, we do not generate an
3863 -- actual subtype, because in the absence of expansion
3864 -- reference to a formal of a protected type, for example,
3865 -- will not be properly transformed, and will lead to
3866 -- out-of-scope references in gigi.
3868 -- In all other cases, we currently build an actual subtype.
3869 -- It seems likely that many of these cases can be avoided,
3870 -- but right now, the front end makes direct references to the
3871 -- bounds (e.g. in generating a length check), and if we do
3872 -- not make an actual subtype, we end up getting a direct
3873 -- reference to a discriminant, which will not do.
3875 elsif Full_Analysis then
3877 Build_Actual_Subtype_Of_Component (Etype (Comp), N);
3878 Insert_Action (N, Act_Decl);
3880 if No (Act_Decl) then
3881 Set_Etype (N, Etype (Comp));
3884 -- Component type depends on discriminants. Enter the
3885 -- main attributes of the subtype.
3888 Subt : constant Entity_Id :=
3889 Defining_Identifier (Act_Decl);
3892 Set_Etype (Subt, Base_Type (Etype (Comp)));
3893 Set_Ekind (Subt, Ekind (Etype (Comp)));
3894 Set_Etype (N, Subt);
3898 -- If Full_Analysis not enabled, just set the Etype
3901 Set_Etype (N, Etype (Comp));
3904 Check_Implicit_Dereference (N, Etype (N));
3908 -- If the prefix is a private extension, check only the visible
3909 -- components of the partial view. This must include the tag,
3910 -- which can appear in expanded code in a tag check.
3912 if Ekind (Type_To_Use) = E_Record_Type_With_Private
3913 and then Chars (Selector_Name (N)) /= Name_uTag
3915 exit when Comp = Last_Entity (Type_To_Use);
3921 -- Ada 2005 (AI-252): The selected component can be interpreted as
3922 -- a prefixed view of a subprogram. Depending on the context, this is
3923 -- either a name that can appear in a renaming declaration, or part
3924 -- of an enclosing call given in prefix form.
3926 -- Ada 2005 (AI05-0030): In the case of dispatching requeue, the
3927 -- selected component should resolve to a name.
3929 if Ada_Version >= Ada_2005
3930 and then Is_Tagged_Type (Prefix_Type)
3931 and then not Is_Concurrent_Type (Prefix_Type)
3933 if Nkind (Parent (N)) = N_Generic_Association
3934 or else Nkind (Parent (N)) = N_Requeue_Statement
3935 or else Nkind (Parent (N)) = N_Subprogram_Renaming_Declaration
3937 if Find_Primitive_Operation (N) then
3941 elsif Try_Object_Operation (N) then
3945 -- If the transformation fails, it will be necessary to redo the
3946 -- analysis with all errors enabled, to indicate candidate
3947 -- interpretations and reasons for each failure ???
3951 elsif Is_Private_Type (Prefix_Type) then
3953 -- Allow access only to discriminants of the type. If the type has
3954 -- no full view, gigi uses the parent type for the components, so we
3955 -- do the same here.
3957 if No (Full_View (Prefix_Type)) then
3958 Type_To_Use := Root_Type (Base_Type (Prefix_Type));
3959 Comp := First_Entity (Type_To_Use);
3962 while Present (Comp) loop
3963 if Chars (Comp) = Chars (Sel) then
3964 if Ekind (Comp) = E_Discriminant then
3965 Set_Entity_With_Style_Check (Sel, Comp);
3966 Generate_Reference (Comp, Sel);
3968 Set_Etype (Sel, Etype (Comp));
3969 Set_Etype (N, Etype (Comp));
3970 Check_Implicit_Dereference (N, Etype (N));
3972 if Is_Generic_Type (Prefix_Type)
3973 or else Is_Generic_Type (Root_Type (Prefix_Type))
3975 Set_Original_Discriminant (Sel, Comp);
3978 -- Before declaring an error, check whether this is tagged
3979 -- private type and a call to a primitive operation.
3981 elsif Ada_Version >= Ada_2005
3982 and then Is_Tagged_Type (Prefix_Type)
3983 and then Try_Object_Operation (N)
3988 Error_Msg_Node_2 := First_Subtype (Prefix_Type);
3989 Error_Msg_NE ("invisible selector& for }", N, Sel);
3990 Set_Entity (Sel, Any_Id);
3991 Set_Etype (N, Any_Type);
4000 elsif Is_Concurrent_Type (Prefix_Type) then
4002 -- Find visible operation with given name. For a protected type,
4003 -- the possible candidates are discriminants, entries or protected
4004 -- procedures. For a task type, the set can only include entries or
4005 -- discriminants if the task type is not an enclosing scope. If it
4006 -- is an enclosing scope (e.g. in an inner task) then all entities
4007 -- are visible, but the prefix must denote the enclosing scope, i.e.
4008 -- can only be a direct name or an expanded name.
4010 Set_Etype (Sel, Any_Type);
4011 In_Scope := In_Open_Scopes (Prefix_Type);
4013 while Present (Comp) loop
4014 if Chars (Comp) = Chars (Sel) then
4015 if Is_Overloadable (Comp) then
4016 Add_One_Interp (Sel, Comp, Etype (Comp));
4018 -- If the prefix is tagged, the correct interpretation may
4019 -- lie in the primitive or class-wide operations of the
4020 -- type. Perform a simple conformance check to determine
4021 -- whether Try_Object_Operation should be invoked even if
4022 -- a visible entity is found.
4024 if Is_Tagged_Type (Prefix_Type)
4026 Nkind_In (Parent (N), N_Procedure_Call_Statement,
4028 N_Indexed_Component)
4029 and then Has_Mode_Conformant_Spec (Comp)
4031 Has_Candidate := True;
4034 -- Note: a selected component may not denote a component of a
4035 -- protected type (4.1.3(7)).
4037 elsif Ekind_In (Comp, E_Discriminant, E_Entry_Family)
4039 and then not Is_Protected_Type (Prefix_Type)
4040 and then Is_Entity_Name (Name))
4042 Set_Entity_With_Style_Check (Sel, Comp);
4043 Generate_Reference (Comp, Sel);
4049 Set_Etype (Sel, Etype (Comp));
4050 Set_Etype (N, Etype (Comp));
4052 if Ekind (Comp) = E_Discriminant then
4053 Set_Original_Discriminant (Sel, Comp);
4056 -- For access type case, introduce explicit dereference for
4057 -- more uniform treatment of entry calls.
4059 if Is_Access_Type (Etype (Name)) then
4060 Insert_Explicit_Dereference (Name);
4062 (Warn_On_Dereference, "?implicit dereference", N);
4068 exit when not In_Scope
4070 Comp = First_Private_Entity (Base_Type (Prefix_Type));
4073 -- If there is no visible entity with the given name or none of the
4074 -- visible entities are plausible interpretations, check whether
4075 -- there is some other primitive operation with that name.
4077 if Ada_Version >= Ada_2005
4078 and then Is_Tagged_Type (Prefix_Type)
4080 if (Etype (N) = Any_Type
4081 or else not Has_Candidate)
4082 and then Try_Object_Operation (N)
4086 -- If the context is not syntactically a procedure call, it
4087 -- may be a call to a primitive function declared outside of
4088 -- the synchronized type.
4090 -- If the context is a procedure call, there might still be
4091 -- an overloading between an entry and a primitive procedure
4092 -- declared outside of the synchronized type, called in prefix
4093 -- notation. This is harder to disambiguate because in one case
4094 -- the controlling formal is implicit ???
4096 elsif Nkind (Parent (N)) /= N_Procedure_Call_Statement
4097 and then Nkind (Parent (N)) /= N_Indexed_Component
4098 and then Try_Object_Operation (N)
4104 if Etype (N) = Any_Type and then Is_Protected_Type (Prefix_Type) then
4105 -- Case of a prefix of a protected type: selector might denote
4106 -- an invisible private component.
4108 Comp := First_Private_Entity (Base_Type (Prefix_Type));
4109 while Present (Comp) and then Chars (Comp) /= Chars (Sel) loop
4113 if Present (Comp) then
4114 if Is_Single_Concurrent_Object then
4115 Error_Msg_Node_2 := Entity (Name);
4116 Error_Msg_NE ("invisible selector& for &", N, Sel);
4119 Error_Msg_Node_2 := First_Subtype (Prefix_Type);
4120 Error_Msg_NE ("invisible selector& for }", N, Sel);
4126 Set_Is_Overloaded (N, Is_Overloaded (Sel));
4131 Error_Msg_NE ("invalid prefix in selected component&", N, Sel);
4134 -- If N still has no type, the component is not defined in the prefix
4136 if Etype (N) = Any_Type then
4138 if Is_Single_Concurrent_Object then
4139 Error_Msg_Node_2 := Entity (Name);
4140 Error_Msg_NE ("no selector& for&", N, Sel);
4142 Check_Misspelled_Selector (Type_To_Use, Sel);
4144 elsif Is_Generic_Type (Prefix_Type)
4145 and then Ekind (Prefix_Type) = E_Record_Type_With_Private
4146 and then Prefix_Type /= Etype (Prefix_Type)
4147 and then Is_Record_Type (Etype (Prefix_Type))
4149 -- If this is a derived formal type, the parent may have
4150 -- different visibility at this point. Try for an inherited
4151 -- component before reporting an error.
4153 Set_Etype (Prefix (N), Etype (Prefix_Type));
4154 Analyze_Selected_Component (N);
4157 -- Similarly, if this is the actual for a formal derived type, the
4158 -- component inherited from the generic parent may not be visible
4159 -- in the actual, but the selected component is legal.
4161 elsif Ekind (Prefix_Type) = E_Record_Subtype_With_Private
4162 and then Is_Generic_Actual_Type (Prefix_Type)
4163 and then Present (Full_View (Prefix_Type))
4166 Find_Component_In_Instance
4167 (Generic_Parent_Type (Parent (Prefix_Type)));
4170 -- Finally, the formal and the actual may be private extensions,
4171 -- but the generic is declared in a child unit of the parent, and
4172 -- an additional step is needed to retrieve the proper scope.
4175 and then Present (Parent_Subtype (Etype (Base_Type (Prefix_Type))))
4177 Find_Component_In_Instance
4178 (Parent_Subtype (Etype (Base_Type (Prefix_Type))));
4181 -- Component not found, specialize error message when appropriate
4184 if Ekind (Prefix_Type) = E_Record_Subtype then
4186 -- Check whether this is a component of the base type which
4187 -- is absent from a statically constrained subtype. This will
4188 -- raise constraint error at run time, but is not a compile-
4189 -- time error. When the selector is illegal for base type as
4190 -- well fall through and generate a compilation error anyway.
4192 Comp := First_Component (Base_Type (Prefix_Type));
4193 while Present (Comp) loop
4194 if Chars (Comp) = Chars (Sel)
4195 and then Is_Visible_Component (Comp)
4197 Set_Entity_With_Style_Check (Sel, Comp);
4198 Generate_Reference (Comp, Sel);
4199 Set_Etype (Sel, Etype (Comp));
4200 Set_Etype (N, Etype (Comp));
4202 -- Emit appropriate message. Gigi will replace the
4203 -- node subsequently with the appropriate Raise.
4205 Apply_Compile_Time_Constraint_Error
4206 (N, "component not present in }?",
4207 CE_Discriminant_Check_Failed,
4208 Ent => Prefix_Type, Rep => False);
4209 Set_Raises_Constraint_Error (N);
4213 Next_Component (Comp);
4218 Error_Msg_Node_2 := First_Subtype (Prefix_Type);
4219 Error_Msg_NE ("no selector& for}", N, Sel);
4221 Check_Misspelled_Selector (Type_To_Use, Sel);
4224 Set_Entity (Sel, Any_Id);
4225 Set_Etype (Sel, Any_Type);
4227 end Analyze_Selected_Component;
4229 ---------------------------
4230 -- Analyze_Short_Circuit --
4231 ---------------------------
4233 procedure Analyze_Short_Circuit (N : Node_Id) is
4234 L : constant Node_Id := Left_Opnd (N);
4235 R : constant Node_Id := Right_Opnd (N);
4240 Analyze_Expression (L);
4241 Analyze_Expression (R);
4242 Set_Etype (N, Any_Type);
4244 if not Is_Overloaded (L) then
4245 if Root_Type (Etype (L)) = Standard_Boolean
4246 and then Has_Compatible_Type (R, Etype (L))
4248 Add_One_Interp (N, Etype (L), Etype (L));
4252 Get_First_Interp (L, Ind, It);
4253 while Present (It.Typ) loop
4254 if Root_Type (It.Typ) = Standard_Boolean
4255 and then Has_Compatible_Type (R, It.Typ)
4257 Add_One_Interp (N, It.Typ, It.Typ);
4260 Get_Next_Interp (Ind, It);
4264 -- Here we have failed to find an interpretation. Clearly we know that
4265 -- it is not the case that both operands can have an interpretation of
4266 -- Boolean, but this is by far the most likely intended interpretation.
4267 -- So we simply resolve both operands as Booleans, and at least one of
4268 -- these resolutions will generate an error message, and we do not need
4269 -- to give another error message on the short circuit operation itself.
4271 if Etype (N) = Any_Type then
4272 Resolve (L, Standard_Boolean);
4273 Resolve (R, Standard_Boolean);
4274 Set_Etype (N, Standard_Boolean);
4276 end Analyze_Short_Circuit;
4282 procedure Analyze_Slice (N : Node_Id) is
4283 P : constant Node_Id := Prefix (N);
4284 D : constant Node_Id := Discrete_Range (N);
4285 Array_Type : Entity_Id;
4287 procedure Analyze_Overloaded_Slice;
4288 -- If the prefix is overloaded, select those interpretations that
4289 -- yield a one-dimensional array type.
4291 ------------------------------
4292 -- Analyze_Overloaded_Slice --
4293 ------------------------------
4295 procedure Analyze_Overloaded_Slice is
4301 Set_Etype (N, Any_Type);
4303 Get_First_Interp (P, I, It);
4304 while Present (It.Nam) loop
4307 if Is_Access_Type (Typ) then
4308 Typ := Designated_Type (Typ);
4309 Error_Msg_NW (Warn_On_Dereference, "?implicit dereference", N);
4312 if Is_Array_Type (Typ)
4313 and then Number_Dimensions (Typ) = 1
4314 and then Has_Compatible_Type (D, Etype (First_Index (Typ)))
4316 Add_One_Interp (N, Typ, Typ);
4319 Get_Next_Interp (I, It);
4322 if Etype (N) = Any_Type then
4323 Error_Msg_N ("expect array type in prefix of slice", N);
4325 end Analyze_Overloaded_Slice;
4327 -- Start of processing for Analyze_Slice
4330 Check_SPARK_Restriction ("slice is not allowed", N);
4335 if Is_Overloaded (P) then
4336 Analyze_Overloaded_Slice;
4339 Array_Type := Etype (P);
4340 Set_Etype (N, Any_Type);
4342 if Is_Access_Type (Array_Type) then
4343 Array_Type := Designated_Type (Array_Type);
4344 Error_Msg_NW (Warn_On_Dereference, "?implicit dereference", N);
4347 if not Is_Array_Type (Array_Type) then
4348 Wrong_Type (P, Any_Array);
4350 elsif Number_Dimensions (Array_Type) > 1 then
4352 ("type is not one-dimensional array in slice prefix", N);
4355 Has_Compatible_Type (D, Etype (First_Index (Array_Type)))
4357 Wrong_Type (D, Etype (First_Index (Array_Type)));
4360 Set_Etype (N, Array_Type);
4365 -----------------------------
4366 -- Analyze_Type_Conversion --
4367 -----------------------------
4369 procedure Analyze_Type_Conversion (N : Node_Id) is
4370 Expr : constant Node_Id := Expression (N);
4374 -- If Conversion_OK is set, then the Etype is already set, and the
4375 -- only processing required is to analyze the expression. This is
4376 -- used to construct certain "illegal" conversions which are not
4377 -- allowed by Ada semantics, but can be handled OK by Gigi, see
4378 -- Sinfo for further details.
4380 if Conversion_OK (N) then
4385 -- Otherwise full type analysis is required, as well as some semantic
4386 -- checks to make sure the argument of the conversion is appropriate.
4388 Find_Type (Subtype_Mark (N));
4389 T := Entity (Subtype_Mark (N));
4391 Check_Fully_Declared (T, N);
4392 Analyze_Expression (Expr);
4393 Validate_Remote_Type_Type_Conversion (N);
4395 -- Only remaining step is validity checks on the argument. These
4396 -- are skipped if the conversion does not come from the source.
4398 if not Comes_From_Source (N) then
4401 -- If there was an error in a generic unit, no need to replicate the
4402 -- error message. Conversely, constant-folding in the generic may
4403 -- transform the argument of a conversion into a string literal, which
4404 -- is legal. Therefore the following tests are not performed in an
4407 elsif In_Instance then
4410 elsif Nkind (Expr) = N_Null then
4411 Error_Msg_N ("argument of conversion cannot be null", N);
4412 Error_Msg_N ("\use qualified expression instead", N);
4413 Set_Etype (N, Any_Type);
4415 elsif Nkind (Expr) = N_Aggregate then
4416 Error_Msg_N ("argument of conversion cannot be aggregate", N);
4417 Error_Msg_N ("\use qualified expression instead", N);
4419 elsif Nkind (Expr) = N_Allocator then
4420 Error_Msg_N ("argument of conversion cannot be an allocator", N);
4421 Error_Msg_N ("\use qualified expression instead", N);
4423 elsif Nkind (Expr) = N_String_Literal then
4424 Error_Msg_N ("argument of conversion cannot be string literal", N);
4425 Error_Msg_N ("\use qualified expression instead", N);
4427 elsif Nkind (Expr) = N_Character_Literal then
4428 if Ada_Version = Ada_83 then
4431 Error_Msg_N ("argument of conversion cannot be character literal",
4433 Error_Msg_N ("\use qualified expression instead", N);
4436 elsif Nkind (Expr) = N_Attribute_Reference
4438 (Attribute_Name (Expr) = Name_Access or else
4439 Attribute_Name (Expr) = Name_Unchecked_Access or else
4440 Attribute_Name (Expr) = Name_Unrestricted_Access)
4442 Error_Msg_N ("argument of conversion cannot be access", N);
4443 Error_Msg_N ("\use qualified expression instead", N);
4445 end Analyze_Type_Conversion;
4447 ----------------------
4448 -- Analyze_Unary_Op --
4449 ----------------------
4451 procedure Analyze_Unary_Op (N : Node_Id) is
4452 R : constant Node_Id := Right_Opnd (N);
4453 Op_Id : Entity_Id := Entity (N);
4456 Set_Etype (N, Any_Type);
4457 Candidate_Type := Empty;
4459 Analyze_Expression (R);
4461 if Present (Op_Id) then
4462 if Ekind (Op_Id) = E_Operator then
4463 Find_Unary_Types (R, Op_Id, N);
4465 Add_One_Interp (N, Op_Id, Etype (Op_Id));
4469 Op_Id := Get_Name_Entity_Id (Chars (N));
4470 while Present (Op_Id) loop
4471 if Ekind (Op_Id) = E_Operator then
4472 if No (Next_Entity (First_Entity (Op_Id))) then
4473 Find_Unary_Types (R, Op_Id, N);
4476 elsif Is_Overloadable (Op_Id) then
4477 Analyze_User_Defined_Unary_Op (N, Op_Id);
4480 Op_Id := Homonym (Op_Id);
4485 end Analyze_Unary_Op;
4487 ----------------------------------
4488 -- Analyze_Unchecked_Expression --
4489 ----------------------------------
4491 procedure Analyze_Unchecked_Expression (N : Node_Id) is
4493 Analyze (Expression (N), Suppress => All_Checks);
4494 Set_Etype (N, Etype (Expression (N)));
4495 Save_Interps (Expression (N), N);
4496 end Analyze_Unchecked_Expression;
4498 ---------------------------------------
4499 -- Analyze_Unchecked_Type_Conversion --
4500 ---------------------------------------
4502 procedure Analyze_Unchecked_Type_Conversion (N : Node_Id) is
4504 Find_Type (Subtype_Mark (N));
4505 Analyze_Expression (Expression (N));
4506 Set_Etype (N, Entity (Subtype_Mark (N)));
4507 end Analyze_Unchecked_Type_Conversion;
4509 ------------------------------------
4510 -- Analyze_User_Defined_Binary_Op --
4511 ------------------------------------
4513 procedure Analyze_User_Defined_Binary_Op
4518 -- Only do analysis if the operator Comes_From_Source, since otherwise
4519 -- the operator was generated by the expander, and all such operators
4520 -- always refer to the operators in package Standard.
4522 if Comes_From_Source (N) then
4524 F1 : constant Entity_Id := First_Formal (Op_Id);
4525 F2 : constant Entity_Id := Next_Formal (F1);
4528 -- Verify that Op_Id is a visible binary function. Note that since
4529 -- we know Op_Id is overloaded, potentially use visible means use
4530 -- visible for sure (RM 9.4(11)).
4532 if Ekind (Op_Id) = E_Function
4533 and then Present (F2)
4534 and then (Is_Immediately_Visible (Op_Id)
4535 or else Is_Potentially_Use_Visible (Op_Id))
4536 and then Has_Compatible_Type (Left_Opnd (N), Etype (F1))
4537 and then Has_Compatible_Type (Right_Opnd (N), Etype (F2))
4539 Add_One_Interp (N, Op_Id, Etype (Op_Id));
4541 -- If the left operand is overloaded, indicate that the
4542 -- current type is a viable candidate. This is redundant
4543 -- in most cases, but for equality and comparison operators
4544 -- where the context does not impose a type on the operands,
4545 -- setting the proper type is necessary to avoid subsequent
4546 -- ambiguities during resolution, when both user-defined and
4547 -- predefined operators may be candidates.
4549 if Is_Overloaded (Left_Opnd (N)) then
4550 Set_Etype (Left_Opnd (N), Etype (F1));
4553 if Debug_Flag_E then
4554 Write_Str ("user defined operator ");
4555 Write_Name (Chars (Op_Id));
4556 Write_Str (" on node ");
4557 Write_Int (Int (N));
4563 end Analyze_User_Defined_Binary_Op;
4565 -----------------------------------
4566 -- Analyze_User_Defined_Unary_Op --
4567 -----------------------------------
4569 procedure Analyze_User_Defined_Unary_Op
4574 -- Only do analysis if the operator Comes_From_Source, since otherwise
4575 -- the operator was generated by the expander, and all such operators
4576 -- always refer to the operators in package Standard.
4578 if Comes_From_Source (N) then
4580 F : constant Entity_Id := First_Formal (Op_Id);
4583 -- Verify that Op_Id is a visible unary function. Note that since
4584 -- we know Op_Id is overloaded, potentially use visible means use
4585 -- visible for sure (RM 9.4(11)).
4587 if Ekind (Op_Id) = E_Function
4588 and then No (Next_Formal (F))
4589 and then (Is_Immediately_Visible (Op_Id)
4590 or else Is_Potentially_Use_Visible (Op_Id))
4591 and then Has_Compatible_Type (Right_Opnd (N), Etype (F))
4593 Add_One_Interp (N, Op_Id, Etype (Op_Id));
4597 end Analyze_User_Defined_Unary_Op;
4599 ---------------------------
4600 -- Check_Arithmetic_Pair --
4601 ---------------------------
4603 procedure Check_Arithmetic_Pair
4604 (T1, T2 : Entity_Id;
4608 Op_Name : constant Name_Id := Chars (Op_Id);
4610 function Has_Fixed_Op (Typ : Entity_Id; Op : Entity_Id) return Boolean;
4611 -- Check whether the fixed-point type Typ has a user-defined operator
4612 -- (multiplication or division) that should hide the corresponding
4613 -- predefined operator. Used to implement Ada 2005 AI-264, to make
4614 -- such operators more visible and therefore useful.
4616 -- If the name of the operation is an expanded name with prefix
4617 -- Standard, the predefined universal fixed operator is available,
4618 -- as specified by AI-420 (RM 4.5.5 (19.1/2)).
4620 function Specific_Type (T1, T2 : Entity_Id) return Entity_Id;
4621 -- Get specific type (i.e. non-universal type if there is one)
4627 function Has_Fixed_Op (Typ : Entity_Id; Op : Entity_Id) return Boolean is
4628 Bas : constant Entity_Id := Base_Type (Typ);
4634 -- If the universal_fixed operation is given explicitly the rule
4635 -- concerning primitive operations of the type do not apply.
4637 if Nkind (N) = N_Function_Call
4638 and then Nkind (Name (N)) = N_Expanded_Name
4639 and then Entity (Prefix (Name (N))) = Standard_Standard
4644 -- The operation is treated as primitive if it is declared in the
4645 -- same scope as the type, and therefore on the same entity chain.
4647 Ent := Next_Entity (Typ);
4648 while Present (Ent) loop
4649 if Chars (Ent) = Chars (Op) then
4650 F1 := First_Formal (Ent);
4651 F2 := Next_Formal (F1);
4653 -- The operation counts as primitive if either operand or
4654 -- result are of the given base type, and both operands are
4655 -- fixed point types.
4657 if (Base_Type (Etype (F1)) = Bas
4658 and then Is_Fixed_Point_Type (Etype (F2)))
4661 (Base_Type (Etype (F2)) = Bas
4662 and then Is_Fixed_Point_Type (Etype (F1)))
4665 (Base_Type (Etype (Ent)) = Bas
4666 and then Is_Fixed_Point_Type (Etype (F1))
4667 and then Is_Fixed_Point_Type (Etype (F2)))
4683 function Specific_Type (T1, T2 : Entity_Id) return Entity_Id is
4685 if T1 = Universal_Integer or else T1 = Universal_Real then
4686 return Base_Type (T2);
4688 return Base_Type (T1);
4692 -- Start of processing for Check_Arithmetic_Pair
4695 if Op_Name = Name_Op_Add or else Op_Name = Name_Op_Subtract then
4697 if Is_Numeric_Type (T1)
4698 and then Is_Numeric_Type (T2)
4699 and then (Covers (T1 => T1, T2 => T2)
4701 Covers (T1 => T2, T2 => T1))
4703 Add_One_Interp (N, Op_Id, Specific_Type (T1, T2));
4706 elsif Op_Name = Name_Op_Multiply or else Op_Name = Name_Op_Divide then
4708 if Is_Fixed_Point_Type (T1)
4709 and then (Is_Fixed_Point_Type (T2)
4710 or else T2 = Universal_Real)
4712 -- If Treat_Fixed_As_Integer is set then the Etype is already set
4713 -- and no further processing is required (this is the case of an
4714 -- operator constructed by Exp_Fixd for a fixed point operation)
4715 -- Otherwise add one interpretation with universal fixed result
4716 -- If the operator is given in functional notation, it comes
4717 -- from source and Fixed_As_Integer cannot apply.
4719 if (Nkind (N) not in N_Op
4720 or else not Treat_Fixed_As_Integer (N))
4722 (not Has_Fixed_Op (T1, Op_Id)
4723 or else Nkind (Parent (N)) = N_Type_Conversion)
4725 Add_One_Interp (N, Op_Id, Universal_Fixed);
4728 elsif Is_Fixed_Point_Type (T2)
4729 and then (Nkind (N) not in N_Op
4730 or else not Treat_Fixed_As_Integer (N))
4731 and then T1 = Universal_Real
4733 (not Has_Fixed_Op (T1, Op_Id)
4734 or else Nkind (Parent (N)) = N_Type_Conversion)
4736 Add_One_Interp (N, Op_Id, Universal_Fixed);
4738 elsif Is_Numeric_Type (T1)
4739 and then Is_Numeric_Type (T2)
4740 and then (Covers (T1 => T1, T2 => T2)
4742 Covers (T1 => T2, T2 => T1))
4744 Add_One_Interp (N, Op_Id, Specific_Type (T1, T2));
4746 elsif Is_Fixed_Point_Type (T1)
4747 and then (Base_Type (T2) = Base_Type (Standard_Integer)
4748 or else T2 = Universal_Integer)
4750 Add_One_Interp (N, Op_Id, T1);
4752 elsif T2 = Universal_Real
4753 and then Base_Type (T1) = Base_Type (Standard_Integer)
4754 and then Op_Name = Name_Op_Multiply
4756 Add_One_Interp (N, Op_Id, Any_Fixed);
4758 elsif T1 = Universal_Real
4759 and then Base_Type (T2) = Base_Type (Standard_Integer)
4761 Add_One_Interp (N, Op_Id, Any_Fixed);
4763 elsif Is_Fixed_Point_Type (T2)
4764 and then (Base_Type (T1) = Base_Type (Standard_Integer)
4765 or else T1 = Universal_Integer)
4766 and then Op_Name = Name_Op_Multiply
4768 Add_One_Interp (N, Op_Id, T2);
4770 elsif T1 = Universal_Real and then T2 = Universal_Integer then
4771 Add_One_Interp (N, Op_Id, T1);
4773 elsif T2 = Universal_Real
4774 and then T1 = Universal_Integer
4775 and then Op_Name = Name_Op_Multiply
4777 Add_One_Interp (N, Op_Id, T2);
4780 elsif Op_Name = Name_Op_Mod or else Op_Name = Name_Op_Rem then
4782 -- Note: The fixed-point operands case with Treat_Fixed_As_Integer
4783 -- set does not require any special processing, since the Etype is
4784 -- already set (case of operation constructed by Exp_Fixed).
4786 if Is_Integer_Type (T1)
4787 and then (Covers (T1 => T1, T2 => T2)
4789 Covers (T1 => T2, T2 => T1))
4791 Add_One_Interp (N, Op_Id, Specific_Type (T1, T2));
4794 elsif Op_Name = Name_Op_Expon then
4795 if Is_Numeric_Type (T1)
4796 and then not Is_Fixed_Point_Type (T1)
4797 and then (Base_Type (T2) = Base_Type (Standard_Integer)
4798 or else T2 = Universal_Integer)
4800 Add_One_Interp (N, Op_Id, Base_Type (T1));
4803 else pragma Assert (Nkind (N) in N_Op_Shift);
4805 -- If not one of the predefined operators, the node may be one
4806 -- of the intrinsic functions. Its kind is always specific, and
4807 -- we can use it directly, rather than the name of the operation.
4809 if Is_Integer_Type (T1)
4810 and then (Base_Type (T2) = Base_Type (Standard_Integer)
4811 or else T2 = Universal_Integer)
4813 Add_One_Interp (N, Op_Id, Base_Type (T1));
4816 end Check_Arithmetic_Pair;
4818 -------------------------------
4819 -- Check_Misspelled_Selector --
4820 -------------------------------
4822 procedure Check_Misspelled_Selector
4823 (Prefix : Entity_Id;
4826 Max_Suggestions : constant := 2;
4827 Nr_Of_Suggestions : Natural := 0;
4829 Suggestion_1 : Entity_Id := Empty;
4830 Suggestion_2 : Entity_Id := Empty;
4835 -- All the components of the prefix of selector Sel are matched
4836 -- against Sel and a count is maintained of possible misspellings.
4837 -- When at the end of the analysis there are one or two (not more!)
4838 -- possible misspellings, these misspellings will be suggested as
4839 -- possible correction.
4841 if not (Is_Private_Type (Prefix) or else Is_Record_Type (Prefix)) then
4843 -- Concurrent types should be handled as well ???
4848 Comp := First_Entity (Prefix);
4849 while Nr_Of_Suggestions <= Max_Suggestions and then Present (Comp) loop
4850 if Is_Visible_Component (Comp) then
4851 if Is_Bad_Spelling_Of (Chars (Comp), Chars (Sel)) then
4852 Nr_Of_Suggestions := Nr_Of_Suggestions + 1;
4854 case Nr_Of_Suggestions is
4855 when 1 => Suggestion_1 := Comp;
4856 when 2 => Suggestion_2 := Comp;
4857 when others => exit;
4862 Comp := Next_Entity (Comp);
4865 -- Report at most two suggestions
4867 if Nr_Of_Suggestions = 1 then
4868 Error_Msg_NE -- CODEFIX
4869 ("\possible misspelling of&", Sel, Suggestion_1);
4871 elsif Nr_Of_Suggestions = 2 then
4872 Error_Msg_Node_2 := Suggestion_2;
4873 Error_Msg_NE -- CODEFIX
4874 ("\possible misspelling of& or&", Sel, Suggestion_1);
4876 end Check_Misspelled_Selector;
4878 ----------------------
4879 -- Defined_In_Scope --
4880 ----------------------
4882 function Defined_In_Scope (T : Entity_Id; S : Entity_Id) return Boolean
4884 S1 : constant Entity_Id := Scope (Base_Type (T));
4887 or else (S1 = System_Aux_Id and then S = Scope (S1));
4888 end Defined_In_Scope;
4894 procedure Diagnose_Call (N : Node_Id; Nam : Node_Id) is
4900 Void_Interp_Seen : Boolean := False;
4903 pragma Warnings (Off, Boolean);
4906 if Ada_Version >= Ada_2005 then
4907 Actual := First_Actual (N);
4908 while Present (Actual) loop
4910 -- Ada 2005 (AI-50217): Post an error in case of premature
4911 -- usage of an entity from the limited view.
4913 if not Analyzed (Etype (Actual))
4914 and then From_With_Type (Etype (Actual))
4916 Error_Msg_Qual_Level := 1;
4918 ("missing with_clause for scope of imported type&",
4919 Actual, Etype (Actual));
4920 Error_Msg_Qual_Level := 0;
4923 Next_Actual (Actual);
4927 -- Analyze each candidate call again, with full error reporting
4931 ("no candidate interpretations match the actuals:!", Nam);
4932 Err_Mode := All_Errors_Mode;
4933 All_Errors_Mode := True;
4935 -- If this is a call to an operation of a concurrent type,
4936 -- the failed interpretations have been removed from the
4937 -- name. Recover them to provide full diagnostics.
4939 if Nkind (Parent (Nam)) = N_Selected_Component then
4940 Set_Entity (Nam, Empty);
4941 New_Nam := New_Copy_Tree (Parent (Nam));
4942 Set_Is_Overloaded (New_Nam, False);
4943 Set_Is_Overloaded (Selector_Name (New_Nam), False);
4944 Set_Parent (New_Nam, Parent (Parent (Nam)));
4945 Analyze_Selected_Component (New_Nam);
4946 Get_First_Interp (Selector_Name (New_Nam), X, It);
4948 Get_First_Interp (Nam, X, It);
4951 while Present (It.Nam) loop
4952 if Etype (It.Nam) = Standard_Void_Type then
4953 Void_Interp_Seen := True;
4956 Analyze_One_Call (N, It.Nam, True, Success);
4957 Get_Next_Interp (X, It);
4960 if Nkind (N) = N_Function_Call then
4961 Get_First_Interp (Nam, X, It);
4962 while Present (It.Nam) loop
4963 if Ekind_In (It.Nam, E_Function, E_Operator) then
4966 Get_Next_Interp (X, It);
4970 -- If all interpretations are procedures, this deserves a
4971 -- more precise message. Ditto if this appears as the prefix
4972 -- of a selected component, which may be a lexical error.
4975 ("\context requires function call, found procedure name", Nam);
4977 if Nkind (Parent (N)) = N_Selected_Component
4978 and then N = Prefix (Parent (N))
4980 Error_Msg_N -- CODEFIX
4981 ("\period should probably be semicolon", Parent (N));
4984 elsif Nkind (N) = N_Procedure_Call_Statement
4985 and then not Void_Interp_Seen
4988 "\function name found in procedure call", Nam);
4991 All_Errors_Mode := Err_Mode;
4994 ---------------------------
4995 -- Find_Arithmetic_Types --
4996 ---------------------------
4998 procedure Find_Arithmetic_Types
5003 Index1 : Interp_Index;
5004 Index2 : Interp_Index;
5008 procedure Check_Right_Argument (T : Entity_Id);
5009 -- Check right operand of operator
5011 --------------------------
5012 -- Check_Right_Argument --
5013 --------------------------
5015 procedure Check_Right_Argument (T : Entity_Id) is
5017 if not Is_Overloaded (R) then
5018 Check_Arithmetic_Pair (T, Etype (R), Op_Id, N);
5020 Get_First_Interp (R, Index2, It2);
5021 while Present (It2.Typ) loop
5022 Check_Arithmetic_Pair (T, It2.Typ, Op_Id, N);
5023 Get_Next_Interp (Index2, It2);
5026 end Check_Right_Argument;
5028 -- Start of processing for Find_Arithmetic_Types
5031 if not Is_Overloaded (L) then
5032 Check_Right_Argument (Etype (L));
5035 Get_First_Interp (L, Index1, It1);
5036 while Present (It1.Typ) loop
5037 Check_Right_Argument (It1.Typ);
5038 Get_Next_Interp (Index1, It1);
5042 end Find_Arithmetic_Types;
5044 ------------------------
5045 -- Find_Boolean_Types --
5046 ------------------------
5048 procedure Find_Boolean_Types
5053 Index : Interp_Index;
5056 procedure Check_Numeric_Argument (T : Entity_Id);
5057 -- Special case for logical operations one of whose operands is an
5058 -- integer literal. If both are literal the result is any modular type.
5060 ----------------------------
5061 -- Check_Numeric_Argument --
5062 ----------------------------
5064 procedure Check_Numeric_Argument (T : Entity_Id) is
5066 if T = Universal_Integer then
5067 Add_One_Interp (N, Op_Id, Any_Modular);
5069 elsif Is_Modular_Integer_Type (T) then
5070 Add_One_Interp (N, Op_Id, T);
5072 end Check_Numeric_Argument;
5074 -- Start of processing for Find_Boolean_Types
5077 if not Is_Overloaded (L) then
5078 if Etype (L) = Universal_Integer
5079 or else Etype (L) = Any_Modular
5081 if not Is_Overloaded (R) then
5082 Check_Numeric_Argument (Etype (R));
5085 Get_First_Interp (R, Index, It);
5086 while Present (It.Typ) loop
5087 Check_Numeric_Argument (It.Typ);
5088 Get_Next_Interp (Index, It);
5092 -- If operands are aggregates, we must assume that they may be
5093 -- boolean arrays, and leave disambiguation for the second pass.
5094 -- If only one is an aggregate, verify that the other one has an
5095 -- interpretation as a boolean array
5097 elsif Nkind (L) = N_Aggregate then
5098 if Nkind (R) = N_Aggregate then
5099 Add_One_Interp (N, Op_Id, Etype (L));
5101 elsif not Is_Overloaded (R) then
5102 if Valid_Boolean_Arg (Etype (R)) then
5103 Add_One_Interp (N, Op_Id, Etype (R));
5107 Get_First_Interp (R, Index, It);
5108 while Present (It.Typ) loop
5109 if Valid_Boolean_Arg (It.Typ) then
5110 Add_One_Interp (N, Op_Id, It.Typ);
5113 Get_Next_Interp (Index, It);
5117 elsif Valid_Boolean_Arg (Etype (L))
5118 and then Has_Compatible_Type (R, Etype (L))
5120 Add_One_Interp (N, Op_Id, Etype (L));
5124 Get_First_Interp (L, Index, It);
5125 while Present (It.Typ) loop
5126 if Valid_Boolean_Arg (It.Typ)
5127 and then Has_Compatible_Type (R, It.Typ)
5129 Add_One_Interp (N, Op_Id, It.Typ);
5132 Get_Next_Interp (Index, It);
5135 end Find_Boolean_Types;
5137 ---------------------------
5138 -- Find_Comparison_Types --
5139 ---------------------------
5141 procedure Find_Comparison_Types
5146 Index : Interp_Index;
5148 Found : Boolean := False;
5151 Scop : Entity_Id := Empty;
5153 procedure Try_One_Interp (T1 : Entity_Id);
5154 -- Routine to try one proposed interpretation. Note that the context
5155 -- of the operator plays no role in resolving the arguments, so that
5156 -- if there is more than one interpretation of the operands that is
5157 -- compatible with comparison, the operation is ambiguous.
5159 --------------------
5160 -- Try_One_Interp --
5161 --------------------
5163 procedure Try_One_Interp (T1 : Entity_Id) is
5166 -- If the operator is an expanded name, then the type of the operand
5167 -- must be defined in the corresponding scope. If the type is
5168 -- universal, the context will impose the correct type.
5171 and then not Defined_In_Scope (T1, Scop)
5172 and then T1 /= Universal_Integer
5173 and then T1 /= Universal_Real
5174 and then T1 /= Any_String
5175 and then T1 /= Any_Composite
5180 if Valid_Comparison_Arg (T1)
5181 and then Has_Compatible_Type (R, T1)
5184 and then Base_Type (T1) /= Base_Type (T_F)
5186 It := Disambiguate (L, I_F, Index, Any_Type);
5188 if It = No_Interp then
5189 Ambiguous_Operands (N);
5190 Set_Etype (L, Any_Type);
5204 Find_Non_Universal_Interpretations (N, R, Op_Id, T1);
5209 -- Start of processing for Find_Comparison_Types
5212 -- If left operand is aggregate, the right operand has to
5213 -- provide a usable type for it.
5215 if Nkind (L) = N_Aggregate
5216 and then Nkind (R) /= N_Aggregate
5218 Find_Comparison_Types (L => R, R => L, Op_Id => Op_Id, N => N);
5222 if Nkind (N) = N_Function_Call
5223 and then Nkind (Name (N)) = N_Expanded_Name
5225 Scop := Entity (Prefix (Name (N)));
5227 -- The prefix may be a package renaming, and the subsequent test
5228 -- requires the original package.
5230 if Ekind (Scop) = E_Package
5231 and then Present (Renamed_Entity (Scop))
5233 Scop := Renamed_Entity (Scop);
5234 Set_Entity (Prefix (Name (N)), Scop);
5238 if not Is_Overloaded (L) then
5239 Try_One_Interp (Etype (L));
5242 Get_First_Interp (L, Index, It);
5243 while Present (It.Typ) loop
5244 Try_One_Interp (It.Typ);
5245 Get_Next_Interp (Index, It);
5248 end Find_Comparison_Types;
5250 ----------------------------------------
5251 -- Find_Non_Universal_Interpretations --
5252 ----------------------------------------
5254 procedure Find_Non_Universal_Interpretations
5260 Index : Interp_Index;
5264 if T1 = Universal_Integer
5265 or else T1 = Universal_Real
5267 if not Is_Overloaded (R) then
5269 (N, Op_Id, Standard_Boolean, Base_Type (Etype (R)));
5271 Get_First_Interp (R, Index, It);
5272 while Present (It.Typ) loop
5273 if Covers (It.Typ, T1) then
5275 (N, Op_Id, Standard_Boolean, Base_Type (It.Typ));
5278 Get_Next_Interp (Index, It);
5282 Add_One_Interp (N, Op_Id, Standard_Boolean, Base_Type (T1));
5284 end Find_Non_Universal_Interpretations;
5286 ------------------------------
5287 -- Find_Concatenation_Types --
5288 ------------------------------
5290 procedure Find_Concatenation_Types
5295 Op_Type : constant Entity_Id := Etype (Op_Id);
5298 if Is_Array_Type (Op_Type)
5299 and then not Is_Limited_Type (Op_Type)
5301 and then (Has_Compatible_Type (L, Op_Type)
5303 Has_Compatible_Type (L, Component_Type (Op_Type)))
5305 and then (Has_Compatible_Type (R, Op_Type)
5307 Has_Compatible_Type (R, Component_Type (Op_Type)))
5309 Add_One_Interp (N, Op_Id, Op_Type);
5311 end Find_Concatenation_Types;
5313 -------------------------
5314 -- Find_Equality_Types --
5315 -------------------------
5317 procedure Find_Equality_Types
5322 Index : Interp_Index;
5324 Found : Boolean := False;
5327 Scop : Entity_Id := Empty;
5329 procedure Try_One_Interp (T1 : Entity_Id);
5330 -- The context of the equality operator plays no role in resolving the
5331 -- arguments, so that if there is more than one interpretation of the
5332 -- operands that is compatible with equality, the construct is ambiguous
5333 -- and an error can be emitted now, after trying to disambiguate, i.e.
5334 -- applying preference rules.
5336 --------------------
5337 -- Try_One_Interp --
5338 --------------------
5340 procedure Try_One_Interp (T1 : Entity_Id) is
5341 Bas : constant Entity_Id := Base_Type (T1);
5344 -- If the operator is an expanded name, then the type of the operand
5345 -- must be defined in the corresponding scope. If the type is
5346 -- universal, the context will impose the correct type. An anonymous
5347 -- type for a 'Access reference is also universal in this sense, as
5348 -- the actual type is obtained from context.
5349 -- In Ada 2005, the equality operator for anonymous access types
5350 -- is declared in Standard, and preference rules apply to it.
5352 if Present (Scop) then
5353 if Defined_In_Scope (T1, Scop)
5354 or else T1 = Universal_Integer
5355 or else T1 = Universal_Real
5356 or else T1 = Any_Access
5357 or else T1 = Any_String
5358 or else T1 = Any_Composite
5359 or else (Ekind (T1) = E_Access_Subprogram_Type
5360 and then not Comes_From_Source (T1))
5364 elsif Ekind (T1) = E_Anonymous_Access_Type
5365 and then Scop = Standard_Standard
5370 -- The scope does not contain an operator for the type
5375 -- If we have infix notation, the operator must be usable.
5376 -- Within an instance, if the type is already established we
5377 -- know it is correct.
5378 -- In Ada 2005, the equality on anonymous access types is declared
5379 -- in Standard, and is always visible.
5381 elsif In_Open_Scopes (Scope (Bas))
5382 or else Is_Potentially_Use_Visible (Bas)
5383 or else In_Use (Bas)
5384 or else (In_Use (Scope (Bas))
5385 and then not Is_Hidden (Bas))
5386 or else (In_Instance
5387 and then First_Subtype (T1) = First_Subtype (Etype (R)))
5388 or else Ekind (T1) = E_Anonymous_Access_Type
5393 -- Save candidate type for subsequent error message, if any
5395 if not Is_Limited_Type (T1) then
5396 Candidate_Type := T1;
5402 -- Ada 2005 (AI-230): Keep restriction imposed by Ada 83 and 95:
5403 -- Do not allow anonymous access types in equality operators.
5405 if Ada_Version < Ada_2005
5406 and then Ekind (T1) = E_Anonymous_Access_Type
5411 if T1 /= Standard_Void_Type
5412 and then not Is_Limited_Type (T1)
5413 and then not Is_Limited_Composite (T1)
5414 and then Has_Compatible_Type (R, T1)
5417 and then Base_Type (T1) /= Base_Type (T_F)
5419 It := Disambiguate (L, I_F, Index, Any_Type);
5421 if It = No_Interp then
5422 Ambiguous_Operands (N);
5423 Set_Etype (L, Any_Type);
5436 if not Analyzed (L) then
5440 Find_Non_Universal_Interpretations (N, R, Op_Id, T1);
5442 -- Case of operator was not visible, Etype still set to Any_Type
5444 if Etype (N) = Any_Type then
5448 elsif Scop = Standard_Standard
5449 and then Ekind (T1) = E_Anonymous_Access_Type
5455 -- Start of processing for Find_Equality_Types
5458 -- If left operand is aggregate, the right operand has to
5459 -- provide a usable type for it.
5461 if Nkind (L) = N_Aggregate
5462 and then Nkind (R) /= N_Aggregate
5464 Find_Equality_Types (L => R, R => L, Op_Id => Op_Id, N => N);
5468 if Nkind (N) = N_Function_Call
5469 and then Nkind (Name (N)) = N_Expanded_Name
5471 Scop := Entity (Prefix (Name (N)));
5473 -- The prefix may be a package renaming, and the subsequent test
5474 -- requires the original package.
5476 if Ekind (Scop) = E_Package
5477 and then Present (Renamed_Entity (Scop))
5479 Scop := Renamed_Entity (Scop);
5480 Set_Entity (Prefix (Name (N)), Scop);
5484 if not Is_Overloaded (L) then
5485 Try_One_Interp (Etype (L));
5488 Get_First_Interp (L, Index, It);
5489 while Present (It.Typ) loop
5490 Try_One_Interp (It.Typ);
5491 Get_Next_Interp (Index, It);
5494 end Find_Equality_Types;
5496 -------------------------
5497 -- Find_Negation_Types --
5498 -------------------------
5500 procedure Find_Negation_Types
5505 Index : Interp_Index;
5509 if not Is_Overloaded (R) then
5510 if Etype (R) = Universal_Integer then
5511 Add_One_Interp (N, Op_Id, Any_Modular);
5512 elsif Valid_Boolean_Arg (Etype (R)) then
5513 Add_One_Interp (N, Op_Id, Etype (R));
5517 Get_First_Interp (R, Index, It);
5518 while Present (It.Typ) loop
5519 if Valid_Boolean_Arg (It.Typ) then
5520 Add_One_Interp (N, Op_Id, It.Typ);
5523 Get_Next_Interp (Index, It);
5526 end Find_Negation_Types;
5528 ------------------------------
5529 -- Find_Primitive_Operation --
5530 ------------------------------
5532 function Find_Primitive_Operation (N : Node_Id) return Boolean is
5533 Obj : constant Node_Id := Prefix (N);
5534 Op : constant Node_Id := Selector_Name (N);
5541 Set_Etype (Op, Any_Type);
5543 if Is_Access_Type (Etype (Obj)) then
5544 Typ := Designated_Type (Etype (Obj));
5549 if Is_Class_Wide_Type (Typ) then
5550 Typ := Root_Type (Typ);
5553 Prims := Primitive_Operations (Typ);
5555 Prim := First_Elmt (Prims);
5556 while Present (Prim) loop
5557 if Chars (Node (Prim)) = Chars (Op) then
5558 Add_One_Interp (Op, Node (Prim), Etype (Node (Prim)));
5559 Set_Etype (N, Etype (Node (Prim)));
5565 -- Now look for class-wide operations of the type or any of its
5566 -- ancestors by iterating over the homonyms of the selector.
5569 Cls_Type : constant Entity_Id := Class_Wide_Type (Typ);
5573 Hom := Current_Entity (Op);
5574 while Present (Hom) loop
5575 if (Ekind (Hom) = E_Procedure
5577 Ekind (Hom) = E_Function)
5578 and then Scope (Hom) = Scope (Typ)
5579 and then Present (First_Formal (Hom))
5581 (Base_Type (Etype (First_Formal (Hom))) = Cls_Type
5583 (Is_Access_Type (Etype (First_Formal (Hom)))
5585 Ekind (Etype (First_Formal (Hom))) =
5586 E_Anonymous_Access_Type
5589 (Designated_Type (Etype (First_Formal (Hom)))) =
5592 Add_One_Interp (Op, Hom, Etype (Hom));
5593 Set_Etype (N, Etype (Hom));
5596 Hom := Homonym (Hom);
5600 return Etype (Op) /= Any_Type;
5601 end Find_Primitive_Operation;
5603 ----------------------
5604 -- Find_Unary_Types --
5605 ----------------------
5607 procedure Find_Unary_Types
5612 Index : Interp_Index;
5616 if not Is_Overloaded (R) then
5617 if Is_Numeric_Type (Etype (R)) then
5618 Add_One_Interp (N, Op_Id, Base_Type (Etype (R)));
5622 Get_First_Interp (R, Index, It);
5623 while Present (It.Typ) loop
5624 if Is_Numeric_Type (It.Typ) then
5625 Add_One_Interp (N, Op_Id, Base_Type (It.Typ));
5628 Get_Next_Interp (Index, It);
5631 end Find_Unary_Types;
5637 function Junk_Operand (N : Node_Id) return Boolean is
5641 if Error_Posted (N) then
5645 -- Get entity to be tested
5647 if Is_Entity_Name (N)
5648 and then Present (Entity (N))
5652 -- An odd case, a procedure name gets converted to a very peculiar
5653 -- function call, and here is where we detect this happening.
5655 elsif Nkind (N) = N_Function_Call
5656 and then Is_Entity_Name (Name (N))
5657 and then Present (Entity (Name (N)))
5661 -- Another odd case, there are at least some cases of selected
5662 -- components where the selected component is not marked as having
5663 -- an entity, even though the selector does have an entity
5665 elsif Nkind (N) = N_Selected_Component
5666 and then Present (Entity (Selector_Name (N)))
5668 Enode := Selector_Name (N);
5674 -- Now test the entity we got to see if it is a bad case
5676 case Ekind (Entity (Enode)) is
5680 ("package name cannot be used as operand", Enode);
5682 when Generic_Unit_Kind =>
5684 ("generic unit name cannot be used as operand", Enode);
5688 ("subtype name cannot be used as operand", Enode);
5692 ("entry name cannot be used as operand", Enode);
5696 ("procedure name cannot be used as operand", Enode);
5700 ("exception name cannot be used as operand", Enode);
5702 when E_Block | E_Label | E_Loop =>
5704 ("label name cannot be used as operand", Enode);
5714 --------------------
5715 -- Operator_Check --
5716 --------------------
5718 procedure Operator_Check (N : Node_Id) is
5720 Remove_Abstract_Operations (N);
5722 -- Test for case of no interpretation found for operator
5724 if Etype (N) = Any_Type then
5728 Op_Id : Entity_Id := Empty;
5731 R := Right_Opnd (N);
5733 if Nkind (N) in N_Binary_Op then
5739 -- If either operand has no type, then don't complain further,
5740 -- since this simply means that we have a propagated error.
5743 or else Etype (R) = Any_Type
5744 or else (Nkind (N) in N_Binary_Op and then Etype (L) = Any_Type)
5748 -- We explicitly check for the case of concatenation of component
5749 -- with component to avoid reporting spurious matching array types
5750 -- that might happen to be lurking in distant packages (such as
5751 -- run-time packages). This also prevents inconsistencies in the
5752 -- messages for certain ACVC B tests, which can vary depending on
5753 -- types declared in run-time interfaces. Another improvement when
5754 -- aggregates are present is to look for a well-typed operand.
5756 elsif Present (Candidate_Type)
5757 and then (Nkind (N) /= N_Op_Concat
5758 or else Is_Array_Type (Etype (L))
5759 or else Is_Array_Type (Etype (R)))
5761 if Nkind (N) = N_Op_Concat then
5762 if Etype (L) /= Any_Composite
5763 and then Is_Array_Type (Etype (L))
5765 Candidate_Type := Etype (L);
5767 elsif Etype (R) /= Any_Composite
5768 and then Is_Array_Type (Etype (R))
5770 Candidate_Type := Etype (R);
5774 Error_Msg_NE -- CODEFIX
5775 ("operator for} is not directly visible!",
5776 N, First_Subtype (Candidate_Type));
5779 U : constant Node_Id :=
5780 Cunit (Get_Source_Unit (Candidate_Type));
5782 if Unit_Is_Visible (U) then
5783 Error_Msg_N -- CODEFIX
5784 ("use clause would make operation legal!", N);
5786 Error_Msg_NE -- CODEFIX
5787 ("add with_clause and use_clause for&!",
5788 N, Defining_Entity (Unit (U)));
5793 -- If either operand is a junk operand (e.g. package name), then
5794 -- post appropriate error messages, but do not complain further.
5796 -- Note that the use of OR in this test instead of OR ELSE is
5797 -- quite deliberate, we may as well check both operands in the
5798 -- binary operator case.
5800 elsif Junk_Operand (R)
5801 or (Nkind (N) in N_Binary_Op and then Junk_Operand (L))
5805 -- If we have a logical operator, one of whose operands is
5806 -- Boolean, then we know that the other operand cannot resolve to
5807 -- Boolean (since we got no interpretations), but in that case we
5808 -- pretty much know that the other operand should be Boolean, so
5809 -- resolve it that way (generating an error)
5811 elsif Nkind_In (N, N_Op_And, N_Op_Or, N_Op_Xor) then
5812 if Etype (L) = Standard_Boolean then
5813 Resolve (R, Standard_Boolean);
5815 elsif Etype (R) = Standard_Boolean then
5816 Resolve (L, Standard_Boolean);
5820 -- For an arithmetic operator or comparison operator, if one
5821 -- of the operands is numeric, then we know the other operand
5822 -- is not the same numeric type. If it is a non-numeric type,
5823 -- then probably it is intended to match the other operand.
5825 elsif Nkind_In (N, N_Op_Add,
5831 Nkind_In (N, N_Op_Lt,
5837 if Is_Numeric_Type (Etype (L))
5838 and then not Is_Numeric_Type (Etype (R))
5840 Resolve (R, Etype (L));
5843 elsif Is_Numeric_Type (Etype (R))
5844 and then not Is_Numeric_Type (Etype (L))
5846 Resolve (L, Etype (R));
5850 -- Comparisons on A'Access are common enough to deserve a
5853 elsif Nkind_In (N, N_Op_Eq, N_Op_Ne)
5854 and then Ekind (Etype (L)) = E_Access_Attribute_Type
5855 and then Ekind (Etype (R)) = E_Access_Attribute_Type
5858 ("two access attributes cannot be compared directly", N);
5860 ("\use qualified expression for one of the operands",
5864 -- Another one for C programmers
5866 elsif Nkind (N) = N_Op_Concat
5867 and then Valid_Boolean_Arg (Etype (L))
5868 and then Valid_Boolean_Arg (Etype (R))
5870 Error_Msg_N ("invalid operands for concatenation", N);
5871 Error_Msg_N -- CODEFIX
5872 ("\maybe AND was meant", N);
5875 -- A special case for comparison of access parameter with null
5877 elsif Nkind (N) = N_Op_Eq
5878 and then Is_Entity_Name (L)
5879 and then Nkind (Parent (Entity (L))) = N_Parameter_Specification
5880 and then Nkind (Parameter_Type (Parent (Entity (L)))) =
5882 and then Nkind (R) = N_Null
5884 Error_Msg_N ("access parameter is not allowed to be null", L);
5885 Error_Msg_N ("\(call would raise Constraint_Error)", L);
5888 -- Another special case for exponentiation, where the right
5889 -- operand must be Natural, independently of the base.
5891 elsif Nkind (N) = N_Op_Expon
5892 and then Is_Numeric_Type (Etype (L))
5893 and then not Is_Overloaded (R)
5895 First_Subtype (Base_Type (Etype (R))) /= Standard_Integer
5896 and then Base_Type (Etype (R)) /= Universal_Integer
5899 ("exponent must be of type Natural, found}", R, Etype (R));
5903 -- If we fall through then just give general message. Note that in
5904 -- the following messages, if the operand is overloaded we choose
5905 -- an arbitrary type to complain about, but that is probably more
5906 -- useful than not giving a type at all.
5908 if Nkind (N) in N_Unary_Op then
5909 Error_Msg_Node_2 := Etype (R);
5910 Error_Msg_N ("operator& not defined for}", N);
5914 if Nkind (N) in N_Binary_Op then
5915 if not Is_Overloaded (L)
5916 and then not Is_Overloaded (R)
5917 and then Base_Type (Etype (L)) = Base_Type (Etype (R))
5919 Error_Msg_Node_2 := First_Subtype (Etype (R));
5920 Error_Msg_N ("there is no applicable operator& for}", N);
5923 -- Another attempt to find a fix: one of the candidate
5924 -- interpretations may not be use-visible. This has
5925 -- already been checked for predefined operators, so
5926 -- we examine only user-defined functions.
5928 Op_Id := Get_Name_Entity_Id (Chars (N));
5930 while Present (Op_Id) loop
5931 if Ekind (Op_Id) /= E_Operator
5932 and then Is_Overloadable (Op_Id)
5934 if not Is_Immediately_Visible (Op_Id)
5935 and then not In_Use (Scope (Op_Id))
5936 and then not Is_Abstract_Subprogram (Op_Id)
5937 and then not Is_Hidden (Op_Id)
5938 and then Ekind (Scope (Op_Id)) = E_Package
5941 (L, Etype (First_Formal (Op_Id)))
5943 (Next_Formal (First_Formal (Op_Id)))
5947 Etype (Next_Formal (First_Formal (Op_Id))))
5950 ("No legal interpretation for operator&", N);
5952 ("\use clause on& would make operation legal",
5958 Op_Id := Homonym (Op_Id);
5962 Error_Msg_N ("invalid operand types for operator&", N);
5964 if Nkind (N) /= N_Op_Concat then
5965 Error_Msg_NE ("\left operand has}!", N, Etype (L));
5966 Error_Msg_NE ("\right operand has}!", N, Etype (R));
5976 -----------------------------------------
5977 -- Process_Implicit_Dereference_Prefix --
5978 -----------------------------------------
5980 function Process_Implicit_Dereference_Prefix
5982 P : Entity_Id) return Entity_Id
5985 Typ : constant Entity_Id := Designated_Type (Etype (P));
5989 and then (Operating_Mode = Check_Semantics or else not Expander_Active)
5991 -- We create a dummy reference to E to ensure that the reference
5992 -- is not considered as part of an assignment (an implicit
5993 -- dereference can never assign to its prefix). The Comes_From_Source
5994 -- attribute needs to be propagated for accurate warnings.
5996 Ref := New_Reference_To (E, Sloc (P));
5997 Set_Comes_From_Source (Ref, Comes_From_Source (P));
5998 Generate_Reference (E, Ref);
6001 -- An implicit dereference is a legal occurrence of an
6002 -- incomplete type imported through a limited_with clause,
6003 -- if the full view is visible.
6005 if From_With_Type (Typ)
6006 and then not From_With_Type (Scope (Typ))
6008 (Is_Immediately_Visible (Scope (Typ))
6010 (Is_Child_Unit (Scope (Typ))
6011 and then Is_Visible_Child_Unit (Scope (Typ))))
6013 return Available_View (Typ);
6018 end Process_Implicit_Dereference_Prefix;
6020 --------------------------------
6021 -- Remove_Abstract_Operations --
6022 --------------------------------
6024 procedure Remove_Abstract_Operations (N : Node_Id) is
6025 Abstract_Op : Entity_Id := Empty;
6026 Address_Kludge : Boolean := False;
6030 -- AI-310: If overloaded, remove abstract non-dispatching operations. We
6031 -- activate this if either extensions are enabled, or if the abstract
6032 -- operation in question comes from a predefined file. This latter test
6033 -- allows us to use abstract to make operations invisible to users. In
6034 -- particular, if type Address is non-private and abstract subprograms
6035 -- are used to hide its operators, they will be truly hidden.
6037 type Operand_Position is (First_Op, Second_Op);
6038 Univ_Type : constant Entity_Id := Universal_Interpretation (N);
6040 procedure Remove_Address_Interpretations (Op : Operand_Position);
6041 -- Ambiguities may arise when the operands are literal and the address
6042 -- operations in s-auxdec are visible. In that case, remove the
6043 -- interpretation of a literal as Address, to retain the semantics of
6044 -- Address as a private type.
6046 ------------------------------------
6047 -- Remove_Address_Interpretations --
6048 ------------------------------------
6050 procedure Remove_Address_Interpretations (Op : Operand_Position) is
6054 if Is_Overloaded (N) then
6055 Get_First_Interp (N, I, It);
6056 while Present (It.Nam) loop
6057 Formal := First_Entity (It.Nam);
6059 if Op = Second_Op then
6060 Formal := Next_Entity (Formal);
6063 if Is_Descendent_Of_Address (Etype (Formal)) then
6064 Address_Kludge := True;
6068 Get_Next_Interp (I, It);
6071 end Remove_Address_Interpretations;
6073 -- Start of processing for Remove_Abstract_Operations
6076 if Is_Overloaded (N) then
6077 Get_First_Interp (N, I, It);
6079 while Present (It.Nam) loop
6080 if Is_Overloadable (It.Nam)
6081 and then Is_Abstract_Subprogram (It.Nam)
6082 and then not Is_Dispatching_Operation (It.Nam)
6084 Abstract_Op := It.Nam;
6086 if Is_Descendent_Of_Address (It.Typ) then
6087 Address_Kludge := True;
6091 -- In Ada 2005, this operation does not participate in Overload
6092 -- resolution. If the operation is defined in a predefined
6093 -- unit, it is one of the operations declared abstract in some
6094 -- variants of System, and it must be removed as well.
6096 elsif Ada_Version >= Ada_2005
6097 or else Is_Predefined_File_Name
6098 (Unit_File_Name (Get_Source_Unit (It.Nam)))
6105 Get_Next_Interp (I, It);
6108 if No (Abstract_Op) then
6110 -- If some interpretation yields an integer type, it is still
6111 -- possible that there are address interpretations. Remove them
6112 -- if one operand is a literal, to avoid spurious ambiguities
6113 -- on systems where Address is a visible integer type.
6115 if Is_Overloaded (N)
6116 and then Nkind (N) in N_Op
6117 and then Is_Integer_Type (Etype (N))
6119 if Nkind (N) in N_Binary_Op then
6120 if Nkind (Right_Opnd (N)) = N_Integer_Literal then
6121 Remove_Address_Interpretations (Second_Op);
6123 elsif Nkind (Right_Opnd (N)) = N_Integer_Literal then
6124 Remove_Address_Interpretations (First_Op);
6129 elsif Nkind (N) in N_Op then
6131 -- Remove interpretations that treat literals as addresses. This
6132 -- is never appropriate, even when Address is defined as a visible
6133 -- Integer type. The reason is that we would really prefer Address
6134 -- to behave as a private type, even in this case, which is there
6135 -- only to accommodate oddities of VMS address sizes. If Address
6136 -- is a visible integer type, we get lots of overload ambiguities.
6138 if Nkind (N) in N_Binary_Op then
6140 U1 : constant Boolean :=
6141 Present (Universal_Interpretation (Right_Opnd (N)));
6142 U2 : constant Boolean :=
6143 Present (Universal_Interpretation (Left_Opnd (N)));
6147 Remove_Address_Interpretations (Second_Op);
6151 Remove_Address_Interpretations (First_Op);
6154 if not (U1 and U2) then
6156 -- Remove corresponding predefined operator, which is
6157 -- always added to the overload set.
6159 Get_First_Interp (N, I, It);
6160 while Present (It.Nam) loop
6161 if Scope (It.Nam) = Standard_Standard
6162 and then Base_Type (It.Typ) =
6163 Base_Type (Etype (Abstract_Op))
6168 Get_Next_Interp (I, It);
6171 elsif Is_Overloaded (N)
6172 and then Present (Univ_Type)
6174 -- If both operands have a universal interpretation,
6175 -- it is still necessary to remove interpretations that
6176 -- yield Address. Any remaining ambiguities will be
6177 -- removed in Disambiguate.
6179 Get_First_Interp (N, I, It);
6180 while Present (It.Nam) loop
6181 if Is_Descendent_Of_Address (It.Typ) then
6184 elsif not Is_Type (It.Nam) then
6185 Set_Entity (N, It.Nam);
6188 Get_Next_Interp (I, It);
6194 elsif Nkind (N) = N_Function_Call
6196 (Nkind (Name (N)) = N_Operator_Symbol
6198 (Nkind (Name (N)) = N_Expanded_Name
6200 Nkind (Selector_Name (Name (N))) = N_Operator_Symbol))
6204 Arg1 : constant Node_Id := First (Parameter_Associations (N));
6205 U1 : constant Boolean :=
6206 Present (Universal_Interpretation (Arg1));
6207 U2 : constant Boolean :=
6208 Present (Next (Arg1)) and then
6209 Present (Universal_Interpretation (Next (Arg1)));
6213 Remove_Address_Interpretations (First_Op);
6217 Remove_Address_Interpretations (Second_Op);
6220 if not (U1 and U2) then
6221 Get_First_Interp (N, I, It);
6222 while Present (It.Nam) loop
6223 if Scope (It.Nam) = Standard_Standard
6224 and then It.Typ = Base_Type (Etype (Abstract_Op))
6229 Get_Next_Interp (I, It);
6235 -- If the removal has left no valid interpretations, emit an error
6236 -- message now and label node as illegal.
6238 if Present (Abstract_Op) then
6239 Get_First_Interp (N, I, It);
6243 -- Removal of abstract operation left no viable candidate
6245 Set_Etype (N, Any_Type);
6246 Error_Msg_Sloc := Sloc (Abstract_Op);
6248 ("cannot call abstract operation& declared#", N, Abstract_Op);
6250 -- In Ada 2005, an abstract operation may disable predefined
6251 -- operators. Since the context is not yet known, we mark the
6252 -- predefined operators as potentially hidden. Do not include
6253 -- predefined operators when addresses are involved since this
6254 -- case is handled separately.
6256 elsif Ada_Version >= Ada_2005
6257 and then not Address_Kludge
6259 while Present (It.Nam) loop
6260 if Is_Numeric_Type (It.Typ)
6261 and then Scope (It.Typ) = Standard_Standard
6263 Set_Abstract_Op (I, Abstract_Op);
6266 Get_Next_Interp (I, It);
6271 end Remove_Abstract_Operations;
6273 -----------------------
6274 -- Try_Indirect_Call --
6275 -----------------------
6277 function Try_Indirect_Call
6280 Typ : Entity_Id) return Boolean
6286 pragma Warnings (Off, Call_OK);
6289 Normalize_Actuals (N, Designated_Type (Typ), False, Call_OK);
6291 Actual := First_Actual (N);
6292 Formal := First_Formal (Designated_Type (Typ));
6293 while Present (Actual) and then Present (Formal) loop
6294 if not Has_Compatible_Type (Actual, Etype (Formal)) then
6299 Next_Formal (Formal);
6302 if No (Actual) and then No (Formal) then
6303 Add_One_Interp (N, Nam, Etype (Designated_Type (Typ)));
6305 -- Nam is a candidate interpretation for the name in the call,
6306 -- if it is not an indirect call.
6308 if not Is_Type (Nam)
6309 and then Is_Entity_Name (Name (N))
6311 Set_Entity (Name (N), Nam);
6318 end Try_Indirect_Call;
6320 ----------------------
6321 -- Try_Indexed_Call --
6322 ----------------------
6324 function Try_Indexed_Call
6328 Skip_First : Boolean) return Boolean
6330 Loc : constant Source_Ptr := Sloc (N);
6331 Actuals : constant List_Id := Parameter_Associations (N);
6336 Actual := First (Actuals);
6338 -- If the call was originally written in prefix form, skip the first
6339 -- actual, which is obviously not defaulted.
6345 Index := First_Index (Typ);
6346 while Present (Actual) and then Present (Index) loop
6348 -- If the parameter list has a named association, the expression
6349 -- is definitely a call and not an indexed component.
6351 if Nkind (Actual) = N_Parameter_Association then
6355 if Is_Entity_Name (Actual)
6356 and then Is_Type (Entity (Actual))
6357 and then No (Next (Actual))
6359 -- A single actual that is a type name indicates a slice if the
6360 -- type is discrete, and an error otherwise.
6362 if Is_Discrete_Type (Entity (Actual)) then
6366 Make_Function_Call (Loc,
6367 Name => Relocate_Node (Name (N))),
6369 New_Occurrence_Of (Entity (Actual), Sloc (Actual))));
6374 Error_Msg_N ("invalid use of type in expression", Actual);
6375 Set_Etype (N, Any_Type);
6380 elsif not Has_Compatible_Type (Actual, Etype (Index)) then
6388 if No (Actual) and then No (Index) then
6389 Add_One_Interp (N, Nam, Component_Type (Typ));
6391 -- Nam is a candidate interpretation for the name in the call,
6392 -- if it is not an indirect call.
6394 if not Is_Type (Nam)
6395 and then Is_Entity_Name (Name (N))
6397 Set_Entity (Name (N), Nam);
6404 end Try_Indexed_Call;
6406 --------------------------
6407 -- Try_Object_Operation --
6408 --------------------------
6410 function Try_Object_Operation (N : Node_Id) return Boolean is
6411 K : constant Node_Kind := Nkind (Parent (N));
6412 Is_Subprg_Call : constant Boolean := Nkind_In
6413 (K, N_Procedure_Call_Statement,
6415 Loc : constant Source_Ptr := Sloc (N);
6416 Obj : constant Node_Id := Prefix (N);
6418 Subprog : constant Node_Id :=
6419 Make_Identifier (Sloc (Selector_Name (N)),
6420 Chars => Chars (Selector_Name (N)));
6421 -- Identifier on which possible interpretations will be collected
6423 Report_Error : Boolean := False;
6424 -- If no candidate interpretation matches the context, redo the
6425 -- analysis with error enabled to provide additional information.
6428 Candidate : Entity_Id := Empty;
6429 New_Call_Node : Node_Id := Empty;
6430 Node_To_Replace : Node_Id;
6431 Obj_Type : Entity_Id := Etype (Obj);
6432 Success : Boolean := False;
6434 function Valid_Candidate
6437 Subp : Entity_Id) return Entity_Id;
6438 -- If the subprogram is a valid interpretation, record it, and add
6439 -- to the list of interpretations of Subprog.
6441 procedure Complete_Object_Operation
6442 (Call_Node : Node_Id;
6443 Node_To_Replace : Node_Id);
6444 -- Make Subprog the name of Call_Node, replace Node_To_Replace with
6445 -- Call_Node, insert the object (or its dereference) as the first actual
6446 -- in the call, and complete the analysis of the call.
6448 procedure Report_Ambiguity (Op : Entity_Id);
6449 -- If a prefixed procedure call is ambiguous, indicate whether the
6450 -- call includes an implicit dereference or an implicit 'Access.
6452 procedure Transform_Object_Operation
6453 (Call_Node : out Node_Id;
6454 Node_To_Replace : out Node_Id);
6455 -- Transform Obj.Operation (X, Y,,) into Operation (Obj, X, Y ..)
6456 -- Call_Node is the resulting subprogram call, Node_To_Replace is
6457 -- either N or the parent of N, and Subprog is a reference to the
6458 -- subprogram we are trying to match.
6460 function Try_Class_Wide_Operation
6461 (Call_Node : Node_Id;
6462 Node_To_Replace : Node_Id) return Boolean;
6463 -- Traverse all ancestor types looking for a class-wide subprogram
6464 -- for which the current operation is a valid non-dispatching call.
6466 procedure Try_One_Prefix_Interpretation (T : Entity_Id);
6467 -- If prefix is overloaded, its interpretation may include different
6468 -- tagged types, and we must examine the primitive operations and
6469 -- the class-wide operations of each in order to find candidate
6470 -- interpretations for the call as a whole.
6472 function Try_Primitive_Operation
6473 (Call_Node : Node_Id;
6474 Node_To_Replace : Node_Id) return Boolean;
6475 -- Traverse the list of primitive subprograms looking for a dispatching
6476 -- operation for which the current node is a valid call .
6478 ---------------------
6479 -- Valid_Candidate --
6480 ---------------------
6482 function Valid_Candidate
6485 Subp : Entity_Id) return Entity_Id
6487 Arr_Type : Entity_Id;
6488 Comp_Type : Entity_Id;
6491 -- If the subprogram is a valid interpretation, record it in global
6492 -- variable Subprog, to collect all possible overloadings.
6495 if Subp /= Entity (Subprog) then
6496 Add_One_Interp (Subprog, Subp, Etype (Subp));
6500 -- If the call may be an indexed call, retrieve component type of
6501 -- resulting expression, and add possible interpretation.
6506 if Nkind (Call) = N_Function_Call
6507 and then Nkind (Parent (N)) = N_Indexed_Component
6508 and then Needs_One_Actual (Subp)
6510 if Is_Array_Type (Etype (Subp)) then
6511 Arr_Type := Etype (Subp);
6513 elsif Is_Access_Type (Etype (Subp))
6514 and then Is_Array_Type (Designated_Type (Etype (Subp)))
6516 Arr_Type := Designated_Type (Etype (Subp));
6520 if Present (Arr_Type) then
6522 -- Verify that the actuals (excluding the object) match the types
6530 Actual := Next (First_Actual (Call));
6531 Index := First_Index (Arr_Type);
6532 while Present (Actual) and then Present (Index) loop
6533 if not Has_Compatible_Type (Actual, Etype (Index)) then
6538 Next_Actual (Actual);
6544 and then Present (Arr_Type)
6546 Comp_Type := Component_Type (Arr_Type);
6550 if Present (Comp_Type)
6551 and then Etype (Subprog) /= Comp_Type
6553 Add_One_Interp (Subprog, Subp, Comp_Type);
6557 if Etype (Call) /= Any_Type then
6562 end Valid_Candidate;
6564 -------------------------------
6565 -- Complete_Object_Operation --
6566 -------------------------------
6568 procedure Complete_Object_Operation
6569 (Call_Node : Node_Id;
6570 Node_To_Replace : Node_Id)
6572 Control : constant Entity_Id := First_Formal (Entity (Subprog));
6573 Formal_Type : constant Entity_Id := Etype (Control);
6574 First_Actual : Node_Id;
6577 -- Place the name of the operation, with its interpretations,
6578 -- on the rewritten call.
6580 Set_Name (Call_Node, Subprog);
6582 First_Actual := First (Parameter_Associations (Call_Node));
6584 -- For cross-reference purposes, treat the new node as being in
6585 -- the source if the original one is.
6587 Set_Comes_From_Source (Subprog, Comes_From_Source (N));
6588 Set_Comes_From_Source (Call_Node, Comes_From_Source (N));
6590 if Nkind (N) = N_Selected_Component
6591 and then not Inside_A_Generic
6593 Set_Entity (Selector_Name (N), Entity (Subprog));
6596 -- If need be, rewrite first actual as an explicit dereference
6597 -- If the call is overloaded, the rewriting can only be done
6598 -- once the primitive operation is identified.
6600 if Is_Overloaded (Subprog) then
6602 -- The prefix itself may be overloaded, and its interpretations
6603 -- must be propagated to the new actual in the call.
6605 if Is_Overloaded (Obj) then
6606 Save_Interps (Obj, First_Actual);
6609 Rewrite (First_Actual, Obj);
6611 elsif not Is_Access_Type (Formal_Type)
6612 and then Is_Access_Type (Etype (Obj))
6614 Rewrite (First_Actual,
6615 Make_Explicit_Dereference (Sloc (Obj), Obj));
6616 Analyze (First_Actual);
6618 -- If we need to introduce an explicit dereference, verify that
6619 -- the resulting actual is compatible with the mode of the formal.
6621 if Ekind (First_Formal (Entity (Subprog))) /= E_In_Parameter
6622 and then Is_Access_Constant (Etype (Obj))
6625 ("expect variable in call to&", Prefix (N), Entity (Subprog));
6628 -- Conversely, if the formal is an access parameter and the object
6629 -- is not, replace the actual with a 'Access reference. Its analysis
6630 -- will check that the object is aliased.
6632 elsif Is_Access_Type (Formal_Type)
6633 and then not Is_Access_Type (Etype (Obj))
6635 -- A special case: A.all'access is illegal if A is an access to a
6636 -- constant and the context requires an access to a variable.
6638 if not Is_Access_Constant (Formal_Type) then
6639 if (Nkind (Obj) = N_Explicit_Dereference
6640 and then Is_Access_Constant (Etype (Prefix (Obj))))
6641 or else not Is_Variable (Obj)
6644 ("actual for& must be a variable", Obj, Control);
6648 Rewrite (First_Actual,
6649 Make_Attribute_Reference (Loc,
6650 Attribute_Name => Name_Access,
6651 Prefix => Relocate_Node (Obj)));
6653 if not Is_Aliased_View (Obj) then
6655 ("object in prefixed call to& must be aliased"
6656 & " (RM-2005 4.3.1 (13))",
6657 Prefix (First_Actual), Subprog);
6660 Analyze (First_Actual);
6663 if Is_Overloaded (Obj) then
6664 Save_Interps (Obj, First_Actual);
6667 Rewrite (First_Actual, Obj);
6670 Rewrite (Node_To_Replace, Call_Node);
6672 -- Propagate the interpretations collected in subprog to the new
6673 -- function call node, to be resolved from context.
6675 if Is_Overloaded (Subprog) then
6676 Save_Interps (Subprog, Node_To_Replace);
6679 Analyze (Node_To_Replace);
6681 -- If the operation has been rewritten into a call, which may get
6682 -- subsequently an explicit dereference, preserve the type on the
6683 -- original node (selected component or indexed component) for
6684 -- subsequent legality tests, e.g. Is_Variable. which examines
6685 -- the original node.
6687 if Nkind (Node_To_Replace) = N_Function_Call then
6689 (Original_Node (Node_To_Replace), Etype (Node_To_Replace));
6692 end Complete_Object_Operation;
6694 ----------------------
6695 -- Report_Ambiguity --
6696 ----------------------
6698 procedure Report_Ambiguity (Op : Entity_Id) is
6699 Access_Formal : constant Boolean :=
6700 Is_Access_Type (Etype (First_Formal (Op)));
6701 Access_Actual : constant Boolean :=
6702 Is_Access_Type (Etype (Prefix (N)));
6705 Error_Msg_Sloc := Sloc (Op);
6707 if Access_Formal and then not Access_Actual then
6708 if Nkind (Parent (Op)) = N_Full_Type_Declaration then
6710 ("\possible interpretation"
6711 & " (inherited, with implicit 'Access) #", N);
6714 ("\possible interpretation (with implicit 'Access) #", N);
6717 elsif not Access_Formal and then Access_Actual then
6718 if Nkind (Parent (Op)) = N_Full_Type_Declaration then
6720 ("\possible interpretation"
6721 & " ( inherited, with implicit dereference) #", N);
6724 ("\possible interpretation (with implicit dereference) #", N);
6728 if Nkind (Parent (Op)) = N_Full_Type_Declaration then
6729 Error_Msg_N ("\possible interpretation (inherited)#", N);
6731 Error_Msg_N -- CODEFIX
6732 ("\possible interpretation#", N);
6735 end Report_Ambiguity;
6737 --------------------------------
6738 -- Transform_Object_Operation --
6739 --------------------------------
6741 procedure Transform_Object_Operation
6742 (Call_Node : out Node_Id;
6743 Node_To_Replace : out Node_Id)
6745 Dummy : constant Node_Id := New_Copy (Obj);
6746 -- Placeholder used as a first parameter in the call, replaced
6747 -- eventually by the proper object.
6749 Parent_Node : constant Node_Id := Parent (N);
6755 -- Common case covering 1) Call to a procedure and 2) Call to a
6756 -- function that has some additional actuals.
6758 if Nkind_In (Parent_Node, N_Function_Call,
6759 N_Procedure_Call_Statement)
6761 -- N is a selected component node containing the name of the
6762 -- subprogram. If N is not the name of the parent node we must
6763 -- not replace the parent node by the new construct. This case
6764 -- occurs when N is a parameterless call to a subprogram that
6765 -- is an actual parameter of a call to another subprogram. For
6767 -- Some_Subprogram (..., Obj.Operation, ...)
6769 and then Name (Parent_Node) = N
6771 Node_To_Replace := Parent_Node;
6773 Actuals := Parameter_Associations (Parent_Node);
6775 if Present (Actuals) then
6776 Prepend (Dummy, Actuals);
6778 Actuals := New_List (Dummy);
6781 if Nkind (Parent_Node) = N_Procedure_Call_Statement then
6783 Make_Procedure_Call_Statement (Loc,
6784 Name => New_Copy (Subprog),
6785 Parameter_Associations => Actuals);
6789 Make_Function_Call (Loc,
6790 Name => New_Copy (Subprog),
6791 Parameter_Associations => Actuals);
6795 -- Before analysis, a function call appears as an indexed component
6796 -- if there are no named associations.
6798 elsif Nkind (Parent_Node) = N_Indexed_Component
6799 and then N = Prefix (Parent_Node)
6801 Node_To_Replace := Parent_Node;
6802 Actuals := Expressions (Parent_Node);
6804 Actual := First (Actuals);
6805 while Present (Actual) loop
6810 Prepend (Dummy, Actuals);
6813 Make_Function_Call (Loc,
6814 Name => New_Copy (Subprog),
6815 Parameter_Associations => Actuals);
6817 -- Parameterless call: Obj.F is rewritten as F (Obj)
6820 Node_To_Replace := N;
6823 Make_Function_Call (Loc,
6824 Name => New_Copy (Subprog),
6825 Parameter_Associations => New_List (Dummy));
6827 end Transform_Object_Operation;
6829 ------------------------------
6830 -- Try_Class_Wide_Operation --
6831 ------------------------------
6833 function Try_Class_Wide_Operation
6834 (Call_Node : Node_Id;
6835 Node_To_Replace : Node_Id) return Boolean
6837 Anc_Type : Entity_Id;
6838 Matching_Op : Entity_Id := Empty;
6841 procedure Traverse_Homonyms
6842 (Anc_Type : Entity_Id;
6843 Error : out Boolean);
6844 -- Traverse the homonym chain of the subprogram searching for those
6845 -- homonyms whose first formal has the Anc_Type's class-wide type,
6846 -- or an anonymous access type designating the class-wide type. If
6847 -- an ambiguity is detected, then Error is set to True.
6849 procedure Traverse_Interfaces
6850 (Anc_Type : Entity_Id;
6851 Error : out Boolean);
6852 -- Traverse the list of interfaces, if any, associated with Anc_Type
6853 -- and search for acceptable class-wide homonyms associated with each
6854 -- interface. If an ambiguity is detected, then Error is set to True.
6856 -----------------------
6857 -- Traverse_Homonyms --
6858 -----------------------
6860 procedure Traverse_Homonyms
6861 (Anc_Type : Entity_Id;
6862 Error : out Boolean)
6864 Cls_Type : Entity_Id;
6872 Cls_Type := Class_Wide_Type (Anc_Type);
6874 Hom := Current_Entity (Subprog);
6876 -- Find a non-hidden operation whose first parameter is of the
6877 -- class-wide type, a subtype thereof, or an anonymous access
6880 while Present (Hom) loop
6881 if Ekind_In (Hom, E_Procedure, E_Function)
6882 and then not Is_Hidden (Hom)
6883 and then Scope (Hom) = Scope (Anc_Type)
6884 and then Present (First_Formal (Hom))
6886 (Base_Type (Etype (First_Formal (Hom))) = Cls_Type
6888 (Is_Access_Type (Etype (First_Formal (Hom)))
6890 Ekind (Etype (First_Formal (Hom))) =
6891 E_Anonymous_Access_Type
6894 (Designated_Type (Etype (First_Formal (Hom)))) =
6897 -- If the context is a procedure call, ignore functions
6898 -- in the name of the call.
6900 if Ekind (Hom) = E_Function
6901 and then Nkind (Parent (N)) = N_Procedure_Call_Statement
6902 and then N = Name (Parent (N))
6907 Set_Etype (Call_Node, Any_Type);
6908 Set_Is_Overloaded (Call_Node, False);
6911 if No (Matching_Op) then
6912 Hom_Ref := New_Reference_To (Hom, Sloc (Subprog));
6913 Set_Etype (Call_Node, Any_Type);
6914 Set_Parent (Call_Node, Parent (Node_To_Replace));
6916 Set_Name (Call_Node, Hom_Ref);
6921 Report => Report_Error,
6923 Skip_First => True);
6926 Valid_Candidate (Success, Call_Node, Hom);
6932 Report => Report_Error,
6934 Skip_First => True);
6936 if Present (Valid_Candidate (Success, Call_Node, Hom))
6937 and then Nkind (Call_Node) /= N_Function_Call
6939 Error_Msg_NE ("ambiguous call to&", N, Hom);
6940 Report_Ambiguity (Matching_Op);
6941 Report_Ambiguity (Hom);
6949 Hom := Homonym (Hom);
6951 end Traverse_Homonyms;
6953 -------------------------
6954 -- Traverse_Interfaces --
6955 -------------------------
6957 procedure Traverse_Interfaces
6958 (Anc_Type : Entity_Id;
6959 Error : out Boolean)
6961 Intface_List : constant List_Id :=
6962 Abstract_Interface_List (Anc_Type);
6968 if Is_Non_Empty_List (Intface_List) then
6969 Intface := First (Intface_List);
6970 while Present (Intface) loop
6972 -- Look for acceptable class-wide homonyms associated with
6975 Traverse_Homonyms (Etype (Intface), Error);
6981 -- Continue the search by looking at each of the interface's
6982 -- associated interface ancestors.
6984 Traverse_Interfaces (Etype (Intface), Error);
6993 end Traverse_Interfaces;
6995 -- Start of processing for Try_Class_Wide_Operation
6998 -- Loop through ancestor types (including interfaces), traversing
6999 -- the homonym chain of the subprogram, trying out those homonyms
7000 -- whose first formal has the class-wide type of the ancestor, or
7001 -- an anonymous access type designating the class-wide type.
7003 Anc_Type := Obj_Type;
7005 -- Look for a match among homonyms associated with the ancestor
7007 Traverse_Homonyms (Anc_Type, Error);
7013 -- Continue the search for matches among homonyms associated with
7014 -- any interfaces implemented by the ancestor.
7016 Traverse_Interfaces (Anc_Type, Error);
7022 exit when Etype (Anc_Type) = Anc_Type;
7023 Anc_Type := Etype (Anc_Type);
7026 if Present (Matching_Op) then
7027 Set_Etype (Call_Node, Etype (Matching_Op));
7030 return Present (Matching_Op);
7031 end Try_Class_Wide_Operation;
7033 -----------------------------------
7034 -- Try_One_Prefix_Interpretation --
7035 -----------------------------------
7037 procedure Try_One_Prefix_Interpretation (T : Entity_Id) is
7041 if Is_Access_Type (Obj_Type) then
7042 Obj_Type := Designated_Type (Obj_Type);
7045 if Ekind (Obj_Type) = E_Private_Subtype then
7046 Obj_Type := Base_Type (Obj_Type);
7049 if Is_Class_Wide_Type (Obj_Type) then
7050 Obj_Type := Etype (Class_Wide_Type (Obj_Type));
7053 -- The type may have be obtained through a limited_with clause,
7054 -- in which case the primitive operations are available on its
7055 -- non-limited view. If still incomplete, retrieve full view.
7057 if Ekind (Obj_Type) = E_Incomplete_Type
7058 and then From_With_Type (Obj_Type)
7060 Obj_Type := Get_Full_View (Non_Limited_View (Obj_Type));
7063 -- If the object is not tagged, or the type is still an incomplete
7064 -- type, this is not a prefixed call.
7066 if not Is_Tagged_Type (Obj_Type)
7067 or else Is_Incomplete_Type (Obj_Type)
7072 if Try_Primitive_Operation
7073 (Call_Node => New_Call_Node,
7074 Node_To_Replace => Node_To_Replace)
7076 Try_Class_Wide_Operation
7077 (Call_Node => New_Call_Node,
7078 Node_To_Replace => Node_To_Replace)
7082 end Try_One_Prefix_Interpretation;
7084 -----------------------------
7085 -- Try_Primitive_Operation --
7086 -----------------------------
7088 function Try_Primitive_Operation
7089 (Call_Node : Node_Id;
7090 Node_To_Replace : Node_Id) return Boolean
7093 Prim_Op : Entity_Id;
7094 Matching_Op : Entity_Id := Empty;
7095 Prim_Op_Ref : Node_Id := Empty;
7097 Corr_Type : Entity_Id := Empty;
7098 -- If the prefix is a synchronized type, the controlling type of
7099 -- the primitive operation is the corresponding record type, else
7100 -- this is the object type itself.
7102 Success : Boolean := False;
7104 function Collect_Generic_Type_Ops (T : Entity_Id) return Elist_Id;
7105 -- For tagged types the candidate interpretations are found in
7106 -- the list of primitive operations of the type and its ancestors.
7107 -- For formal tagged types we have to find the operations declared
7108 -- in the same scope as the type (including in the generic formal
7109 -- part) because the type itself carries no primitive operations,
7110 -- except for formal derived types that inherit the operations of
7111 -- the parent and progenitors.
7112 -- If the context is a generic subprogram body, the generic formals
7113 -- are visible by name, but are not in the entity list of the
7114 -- subprogram because that list starts with the subprogram formals.
7115 -- We retrieve the candidate operations from the generic declaration.
7117 function Is_Private_Overriding (Op : Entity_Id) return Boolean;
7118 -- An operation that overrides an inherited operation in the private
7119 -- part of its package may be hidden, but if the inherited operation
7120 -- is visible a direct call to it will dispatch to the private one,
7121 -- which is therefore a valid candidate.
7123 function Valid_First_Argument_Of (Op : Entity_Id) return Boolean;
7124 -- Verify that the prefix, dereferenced if need be, is a valid
7125 -- controlling argument in a call to Op. The remaining actuals
7126 -- are checked in the subsequent call to Analyze_One_Call.
7128 ------------------------------
7129 -- Collect_Generic_Type_Ops --
7130 ------------------------------
7132 function Collect_Generic_Type_Ops (T : Entity_Id) return Elist_Id is
7133 Bas : constant Entity_Id := Base_Type (T);
7134 Candidates : constant Elist_Id := New_Elmt_List;
7138 procedure Check_Candidate;
7139 -- The operation is a candidate if its first parameter is a
7140 -- controlling operand of the desired type.
7142 -----------------------
7143 -- Check_Candidate; --
7144 -----------------------
7146 procedure Check_Candidate is
7148 Formal := First_Formal (Subp);
7151 and then Is_Controlling_Formal (Formal)
7153 (Base_Type (Etype (Formal)) = Bas
7155 (Is_Access_Type (Etype (Formal))
7156 and then Designated_Type (Etype (Formal)) = Bas))
7158 Append_Elmt (Subp, Candidates);
7160 end Check_Candidate;
7162 -- Start of processing for Collect_Generic_Type_Ops
7165 if Is_Derived_Type (T) then
7166 return Primitive_Operations (T);
7168 elsif Ekind_In (Scope (T), E_Procedure, E_Function) then
7170 -- Scan the list of generic formals to find subprograms
7171 -- that may have a first controlling formal of the type.
7173 if Nkind (Unit_Declaration_Node (Scope (T)))
7174 = N_Generic_Subprogram_Declaration
7181 First (Generic_Formal_Declarations
7182 (Unit_Declaration_Node (Scope (T))));
7183 while Present (Decl) loop
7184 if Nkind (Decl) in N_Formal_Subprogram_Declaration then
7185 Subp := Defining_Entity (Decl);
7196 -- Scan the list of entities declared in the same scope as
7197 -- the type. In general this will be an open scope, given that
7198 -- the call we are analyzing can only appear within a generic
7199 -- declaration or body (either the one that declares T, or a
7202 -- For a subtype representing a generic actual type, go to the
7205 if Is_Generic_Actual_Type (T) then
7206 Subp := First_Entity (Scope (Base_Type (T)));
7208 Subp := First_Entity (Scope (T));
7211 while Present (Subp) loop
7212 if Is_Overloadable (Subp) then
7221 end Collect_Generic_Type_Ops;
7223 ---------------------------
7224 -- Is_Private_Overriding --
7225 ---------------------------
7227 function Is_Private_Overriding (Op : Entity_Id) return Boolean is
7228 Visible_Op : constant Entity_Id := Homonym (Op);
7231 return Present (Visible_Op)
7232 and then Scope (Op) = Scope (Visible_Op)
7233 and then not Comes_From_Source (Visible_Op)
7234 and then Alias (Visible_Op) = Op
7235 and then not Is_Hidden (Visible_Op);
7236 end Is_Private_Overriding;
7238 -----------------------------
7239 -- Valid_First_Argument_Of --
7240 -----------------------------
7242 function Valid_First_Argument_Of (Op : Entity_Id) return Boolean is
7243 Typ : Entity_Id := Etype (First_Formal (Op));
7246 if Is_Concurrent_Type (Typ)
7247 and then Present (Corresponding_Record_Type (Typ))
7249 Typ := Corresponding_Record_Type (Typ);
7252 -- Simple case. Object may be a subtype of the tagged type or
7253 -- may be the corresponding record of a synchronized type.
7255 return Obj_Type = Typ
7256 or else Base_Type (Obj_Type) = Typ
7257 or else Corr_Type = Typ
7259 -- Prefix can be dereferenced
7262 (Is_Access_Type (Corr_Type)
7263 and then Designated_Type (Corr_Type) = Typ)
7265 -- Formal is an access parameter, for which the object
7266 -- can provide an access.
7269 (Ekind (Typ) = E_Anonymous_Access_Type
7271 Base_Type (Designated_Type (Typ)) = Base_Type (Corr_Type));
7272 end Valid_First_Argument_Of;
7274 -- Start of processing for Try_Primitive_Operation
7277 -- Look for subprograms in the list of primitive operations. The name
7278 -- must be identical, and the kind of call indicates the expected
7279 -- kind of operation (function or procedure). If the type is a
7280 -- (tagged) synchronized type, the primitive ops are attached to the
7281 -- corresponding record (base) type.
7283 if Is_Concurrent_Type (Obj_Type) then
7284 if Present (Corresponding_Record_Type (Obj_Type)) then
7285 Corr_Type := Base_Type (Corresponding_Record_Type (Obj_Type));
7286 Elmt := First_Elmt (Primitive_Operations (Corr_Type));
7288 Corr_Type := Obj_Type;
7289 Elmt := First_Elmt (Collect_Generic_Type_Ops (Obj_Type));
7292 elsif not Is_Generic_Type (Obj_Type) then
7293 Corr_Type := Obj_Type;
7294 Elmt := First_Elmt (Primitive_Operations (Obj_Type));
7297 Corr_Type := Obj_Type;
7298 Elmt := First_Elmt (Collect_Generic_Type_Ops (Obj_Type));
7301 while Present (Elmt) loop
7302 Prim_Op := Node (Elmt);
7304 if Chars (Prim_Op) = Chars (Subprog)
7305 and then Present (First_Formal (Prim_Op))
7306 and then Valid_First_Argument_Of (Prim_Op)
7308 (Nkind (Call_Node) = N_Function_Call)
7309 = (Ekind (Prim_Op) = E_Function)
7311 -- Ada 2005 (AI-251): If this primitive operation corresponds
7312 -- with an immediate ancestor interface there is no need to add
7313 -- it to the list of interpretations; the corresponding aliased
7314 -- primitive is also in this list of primitive operations and
7315 -- will be used instead.
7317 if (Present (Interface_Alias (Prim_Op))
7318 and then Is_Ancestor (Find_Dispatching_Type
7319 (Alias (Prim_Op)), Corr_Type))
7321 -- Do not consider hidden primitives unless the type is in an
7322 -- open scope or we are within an instance, where visibility
7323 -- is known to be correct, or else if this is an overriding
7324 -- operation in the private part for an inherited operation.
7326 or else (Is_Hidden (Prim_Op)
7327 and then not Is_Immediately_Visible (Obj_Type)
7328 and then not In_Instance
7329 and then not Is_Private_Overriding (Prim_Op))
7334 Set_Etype (Call_Node, Any_Type);
7335 Set_Is_Overloaded (Call_Node, False);
7337 if No (Matching_Op) then
7338 Prim_Op_Ref := New_Reference_To (Prim_Op, Sloc (Subprog));
7339 Candidate := Prim_Op;
7341 Set_Parent (Call_Node, Parent (Node_To_Replace));
7343 Set_Name (Call_Node, Prim_Op_Ref);
7349 Report => Report_Error,
7351 Skip_First => True);
7353 Matching_Op := Valid_Candidate (Success, Call_Node, Prim_Op);
7355 -- More than one interpretation, collect for subsequent
7356 -- disambiguation. If this is a procedure call and there
7357 -- is another match, report ambiguity now.
7363 Report => Report_Error,
7365 Skip_First => True);
7367 if Present (Valid_Candidate (Success, Call_Node, Prim_Op))
7368 and then Nkind (Call_Node) /= N_Function_Call
7370 Error_Msg_NE ("ambiguous call to&", N, Prim_Op);
7371 Report_Ambiguity (Matching_Op);
7372 Report_Ambiguity (Prim_Op);
7382 if Present (Matching_Op) then
7383 Set_Etype (Call_Node, Etype (Matching_Op));
7386 return Present (Matching_Op);
7387 end Try_Primitive_Operation;
7389 -- Start of processing for Try_Object_Operation
7392 Analyze_Expression (Obj);
7394 -- Analyze the actuals if node is known to be a subprogram call
7396 if Is_Subprg_Call and then N = Name (Parent (N)) then
7397 Actual := First (Parameter_Associations (Parent (N)));
7398 while Present (Actual) loop
7399 Analyze_Expression (Actual);
7404 -- Build a subprogram call node, using a copy of Obj as its first
7405 -- actual. This is a placeholder, to be replaced by an explicit
7406 -- dereference when needed.
7408 Transform_Object_Operation
7409 (Call_Node => New_Call_Node,
7410 Node_To_Replace => Node_To_Replace);
7412 Set_Etype (New_Call_Node, Any_Type);
7413 Set_Etype (Subprog, Any_Type);
7414 Set_Parent (New_Call_Node, Parent (Node_To_Replace));
7416 if not Is_Overloaded (Obj) then
7417 Try_One_Prefix_Interpretation (Obj_Type);
7424 Get_First_Interp (Obj, I, It);
7425 while Present (It.Nam) loop
7426 Try_One_Prefix_Interpretation (It.Typ);
7427 Get_Next_Interp (I, It);
7432 if Etype (New_Call_Node) /= Any_Type then
7433 Complete_Object_Operation
7434 (Call_Node => New_Call_Node,
7435 Node_To_Replace => Node_To_Replace);
7438 elsif Present (Candidate) then
7440 -- The argument list is not type correct. Re-analyze with error
7441 -- reporting enabled, and use one of the possible candidates.
7442 -- In All_Errors_Mode, re-analyze all failed interpretations.
7444 if All_Errors_Mode then
7445 Report_Error := True;
7446 if Try_Primitive_Operation
7447 (Call_Node => New_Call_Node,
7448 Node_To_Replace => Node_To_Replace)
7451 Try_Class_Wide_Operation
7452 (Call_Node => New_Call_Node,
7453 Node_To_Replace => Node_To_Replace)
7460 (N => New_Call_Node,
7464 Skip_First => True);
7467 -- No need for further errors
7472 -- There was no candidate operation, so report it as an error
7473 -- in the caller: Analyze_Selected_Component.
7477 end Try_Object_Operation;
7483 procedure wpo (T : Entity_Id) is
7488 if not Is_Tagged_Type (T) then
7492 E := First_Elmt (Primitive_Operations (Base_Type (T)));
7493 while Present (E) loop
7495 Write_Int (Int (Op));
7496 Write_Str (" === ");
7497 Write_Name (Chars (Op));
7499 Write_Name (Chars (Scope (Op)));