1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2008, 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_Cat; use Sem_Cat;
46 with Sem_Ch3; use Sem_Ch3;
47 with Sem_Ch6; use Sem_Ch6;
48 with Sem_Ch8; use Sem_Ch8;
49 with Sem_Disp; use Sem_Disp;
50 with Sem_Dist; use Sem_Dist;
51 with Sem_Eval; use Sem_Eval;
52 with Sem_Res; use Sem_Res;
53 with Sem_Util; use Sem_Util;
54 with Sem_Type; use Sem_Type;
55 with Stand; use Stand;
56 with Sinfo; use Sinfo;
57 with Snames; use Snames;
58 with Tbuild; use Tbuild;
60 package body Sem_Ch4 is
62 -----------------------
63 -- Local Subprograms --
64 -----------------------
66 procedure Analyze_Concatenation_Rest (N : Node_Id);
67 -- Does the "rest" of the work of Analyze_Concatenation, after the left
68 -- operand has been analyzed. See Analyze_Concatenation for details.
70 procedure Analyze_Expression (N : Node_Id);
71 -- For expressions that are not names, this is just a call to analyze.
72 -- If the expression is a name, it may be a call to a parameterless
73 -- function, and if so must be converted into an explicit call node
74 -- and analyzed as such. This deproceduring must be done during the first
75 -- pass of overload resolution, because otherwise a procedure call with
76 -- overloaded actuals may fail to resolve.
78 procedure Analyze_Operator_Call (N : Node_Id; Op_Id : Entity_Id);
79 -- Analyze a call of the form "+"(x, y), etc. The prefix of the call
80 -- is an operator name or an expanded name whose selector is an operator
81 -- name, and one possible interpretation is as a predefined operator.
83 procedure Analyze_Overloaded_Selected_Component (N : Node_Id);
84 -- If the prefix of a selected_component is overloaded, the proper
85 -- interpretation that yields a record type with the proper selector
86 -- name must be selected.
88 procedure Analyze_User_Defined_Binary_Op (N : Node_Id; Op_Id : Entity_Id);
89 -- Procedure to analyze a user defined binary operator, which is resolved
90 -- like a function, but instead of a list of actuals it is presented
91 -- with the left and right operands of an operator node.
93 procedure Analyze_User_Defined_Unary_Op (N : Node_Id; Op_Id : Entity_Id);
94 -- Procedure to analyze a user defined unary operator, which is resolved
95 -- like a function, but instead of a list of actuals, it is presented with
96 -- the operand of the operator node.
98 procedure Ambiguous_Operands (N : Node_Id);
99 -- for equality, membership, and comparison operators with overloaded
100 -- arguments, list possible interpretations.
102 procedure Analyze_One_Call
106 Success : out Boolean;
107 Skip_First : Boolean := False);
108 -- Check one interpretation of an overloaded subprogram name for
109 -- compatibility with the types of the actuals in a call. If there is a
110 -- single interpretation which does not match, post error if Report is
113 -- Nam is the entity that provides the formals against which the actuals
114 -- are checked. Nam is either the name of a subprogram, or the internal
115 -- subprogram type constructed for an access_to_subprogram. If the actuals
116 -- are compatible with Nam, then Nam is added to the list of candidate
117 -- interpretations for N, and Success is set to True.
119 -- The flag Skip_First is used when analyzing a call that was rewritten
120 -- from object notation. In this case the first actual may have to receive
121 -- an explicit dereference, depending on the first formal of the operation
122 -- being called. The caller will have verified that the object is legal
123 -- for the call. If the remaining parameters match, the first parameter
124 -- will rewritten as a dereference if needed, prior to completing analysis.
126 procedure Check_Misspelled_Selector
129 -- Give possible misspelling diagnostic if Sel is likely to be
130 -- a misspelling of one of the selectors of the Prefix.
131 -- This is called by Analyze_Selected_Component after producing
132 -- an invalid selector error message.
134 function Defined_In_Scope (T : Entity_Id; S : Entity_Id) return Boolean;
135 -- Verify that type T is declared in scope S. Used to find intepretations
136 -- for operators given by expanded names. This is abstracted as a separate
137 -- function to handle extensions to System, where S is System, but T is
138 -- declared in the extension.
140 procedure Find_Arithmetic_Types
144 -- L and R are the operands of an arithmetic operator. Find
145 -- consistent pairs of interpretations for L and R that have a
146 -- numeric type consistent with the semantics of the operator.
148 procedure Find_Comparison_Types
152 -- L and R are operands of a comparison operator. Find consistent
153 -- pairs of interpretations for L and R.
155 procedure Find_Concatenation_Types
159 -- For the four varieties of concatenation
161 procedure Find_Equality_Types
165 -- Ditto for equality operators
167 procedure Find_Boolean_Types
171 -- Ditto for binary logical operations
173 procedure Find_Negation_Types
177 -- Find consistent interpretation for operand of negation operator
179 procedure Find_Non_Universal_Interpretations
184 -- For equality and comparison operators, the result is always boolean,
185 -- and the legality of the operation is determined from the visibility
186 -- of the operand types. If one of the operands has a universal interpre-
187 -- tation, the legality check uses some compatible non-universal
188 -- interpretation of the other operand. N can be an operator node, or
189 -- a function call whose name is an operator designator.
191 function Find_Primitive_Operation (N : Node_Id) return Boolean;
192 -- Find candidate interpretations for the name Obj.Proc when it appears
193 -- in a subprogram renaming declaration.
195 procedure Find_Unary_Types
199 -- Unary arithmetic types: plus, minus, abs
201 procedure Check_Arithmetic_Pair
205 -- Subsidiary procedure to Find_Arithmetic_Types. T1 and T2 are valid
206 -- types for left and right operand. Determine whether they constitute
207 -- a valid pair for the given operator, and record the corresponding
208 -- interpretation of the operator node. The node N may be an operator
209 -- node (the usual case) or a function call whose prefix is an operator
210 -- designator. In both cases Op_Id is the operator name itself.
212 procedure Diagnose_Call (N : Node_Id; Nam : Node_Id);
213 -- Give detailed information on overloaded call where none of the
214 -- interpretations match. N is the call node, Nam the designator for
215 -- the overloaded entity being called.
217 function Junk_Operand (N : Node_Id) return Boolean;
218 -- Test for an operand that is an inappropriate entity (e.g. a package
219 -- name or a label). If so, issue an error message and return True. If
220 -- the operand is not an inappropriate entity kind, return False.
222 procedure Operator_Check (N : Node_Id);
223 -- Verify that an operator has received some valid interpretation. If none
224 -- was found, determine whether a use clause would make the operation
225 -- legal. The variable Candidate_Type (defined in Sem_Type) is set for
226 -- every type compatible with the operator, even if the operator for the
227 -- type is not directly visible. The routine uses this type to emit a more
228 -- informative message.
230 function Process_Implicit_Dereference_Prefix
232 P : Node_Id) return Entity_Id;
233 -- Called when P is the prefix of an implicit dereference, denoting an
234 -- object E. The function returns the designated type of the prefix, taking
235 -- into account that the designated type of an anonymous access type may be
236 -- a limited view, when the non-limited view is visible.
237 -- If in semantics only mode (-gnatc or generic), the function also records
238 -- that the prefix is a reference to E, if any. Normally, such a reference
239 -- is generated only when the implicit dereference is expanded into an
240 -- explicit one, but for consistency we must generate the reference when
241 -- expansion is disabled as well.
243 procedure Remove_Abstract_Operations (N : Node_Id);
244 -- Ada 2005: implementation of AI-310. An abstract non-dispatching
245 -- operation is not a candidate interpretation.
247 function Try_Indexed_Call
251 Skip_First : Boolean) return Boolean;
252 -- If a function has defaults for all its actuals, a call to it may in fact
253 -- be an indexing on the result of the call. Try_Indexed_Call attempts the
254 -- interpretation as an indexing, prior to analysis as a call. If both are
255 -- possible, the node is overloaded with both interpretations (same symbol
256 -- but two different types). If the call is written in prefix form, the
257 -- prefix becomes the first parameter in the call, and only the remaining
258 -- actuals must be checked for the presence of defaults.
260 function Try_Indirect_Call
263 Typ : Entity_Id) return Boolean;
264 -- Similarly, a function F that needs no actuals can return an access to a
265 -- subprogram, and the call F (X) interpreted as F.all (X). In this case
266 -- the call may be overloaded with both interpretations.
268 function Try_Object_Operation (N : Node_Id) return Boolean;
269 -- Ada 2005 (AI-252): Support the object.operation notation
271 procedure wpo (T : Entity_Id);
272 pragma Warnings (Off, wpo);
273 -- Used for debugging: obtain list of primitive operations even if
274 -- type is not frozen and dispatch table is not built yet.
276 ------------------------
277 -- Ambiguous_Operands --
278 ------------------------
280 procedure Ambiguous_Operands (N : Node_Id) is
281 procedure List_Operand_Interps (Opnd : Node_Id);
283 --------------------------
284 -- List_Operand_Interps --
285 --------------------------
287 procedure List_Operand_Interps (Opnd : Node_Id) is
292 if Is_Overloaded (Opnd) then
293 if Nkind (Opnd) in N_Op then
295 elsif Nkind (Opnd) = N_Function_Call then
305 if Opnd = Left_Opnd (N) then
307 ("\left operand has the following interpretations", N);
310 ("\right operand has the following interpretations", N);
314 List_Interps (Nam, Err);
315 end List_Operand_Interps;
317 -- Start of processing for Ambiguous_Operands
320 if Nkind (N) in N_Membership_Test then
321 Error_Msg_N ("ambiguous operands for membership", N);
323 elsif Nkind_In (N, N_Op_Eq, N_Op_Ne) then
324 Error_Msg_N ("ambiguous operands for equality", N);
327 Error_Msg_N ("ambiguous operands for comparison", N);
330 if All_Errors_Mode then
331 List_Operand_Interps (Left_Opnd (N));
332 List_Operand_Interps (Right_Opnd (N));
334 Error_Msg_N ("\use -gnatf switch for details", N);
336 end Ambiguous_Operands;
338 -----------------------
339 -- Analyze_Aggregate --
340 -----------------------
342 -- Most of the analysis of Aggregates requires that the type be known,
343 -- and is therefore put off until resolution.
345 procedure Analyze_Aggregate (N : Node_Id) is
347 if No (Etype (N)) then
348 Set_Etype (N, Any_Composite);
350 end Analyze_Aggregate;
352 -----------------------
353 -- Analyze_Allocator --
354 -----------------------
356 procedure Analyze_Allocator (N : Node_Id) is
357 Loc : constant Source_Ptr := Sloc (N);
358 Sav_Errs : constant Nat := Serious_Errors_Detected;
359 E : Node_Id := Expression (N);
360 Acc_Type : Entity_Id;
364 -- In accordance with H.4(7), the No_Allocators restriction only applies
365 -- to user-written allocators.
367 if Comes_From_Source (N) then
368 Check_Restriction (No_Allocators, N);
371 if Nkind (E) = N_Qualified_Expression then
372 Acc_Type := Create_Itype (E_Allocator_Type, N);
373 Set_Etype (Acc_Type, Acc_Type);
374 Find_Type (Subtype_Mark (E));
376 -- Analyze the qualified expression, and apply the name resolution
377 -- rule given in 4.7 (3).
380 Type_Id := Etype (E);
381 Set_Directly_Designated_Type (Acc_Type, Type_Id);
383 Resolve (Expression (E), Type_Id);
385 if Is_Limited_Type (Type_Id)
386 and then Comes_From_Source (N)
387 and then not In_Instance_Body
389 if not OK_For_Limited_Init (Expression (E)) then
390 Error_Msg_N ("initialization not allowed for limited types", N);
391 Explain_Limited_Type (Type_Id, N);
395 -- A qualified expression requires an exact match of the type,
396 -- class-wide matching is not allowed.
398 -- if Is_Class_Wide_Type (Type_Id)
399 -- and then Base_Type
400 -- (Etype (Expression (E))) /= Base_Type (Type_Id)
402 -- Wrong_Type (Expression (E), Type_Id);
405 Check_Non_Static_Context (Expression (E));
407 -- We don't analyze the qualified expression itself because it's
408 -- part of the allocator
410 Set_Etype (E, Type_Id);
412 -- Case where allocator has a subtype indication
417 Base_Typ : Entity_Id;
420 -- If the allocator includes a N_Subtype_Indication then a
421 -- constraint is present, otherwise the node is a subtype mark.
422 -- Introduce an explicit subtype declaration into the tree
423 -- defining some anonymous subtype and rewrite the allocator to
424 -- use this subtype rather than the subtype indication.
426 -- It is important to introduce the explicit subtype declaration
427 -- so that the bounds of the subtype indication are attached to
428 -- the tree in case the allocator is inside a generic unit.
430 if Nkind (E) = N_Subtype_Indication then
432 -- A constraint is only allowed for a composite type in Ada
433 -- 95. In Ada 83, a constraint is also allowed for an
434 -- access-to-composite type, but the constraint is ignored.
436 Find_Type (Subtype_Mark (E));
437 Base_Typ := Entity (Subtype_Mark (E));
439 if Is_Elementary_Type (Base_Typ) then
440 if not (Ada_Version = Ada_83
441 and then Is_Access_Type (Base_Typ))
443 Error_Msg_N ("constraint not allowed here", E);
445 if Nkind (Constraint (E)) =
446 N_Index_Or_Discriminant_Constraint
449 ("\if qualified expression was meant, " &
450 "use apostrophe", Constraint (E));
454 -- Get rid of the bogus constraint:
456 Rewrite (E, New_Copy_Tree (Subtype_Mark (E)));
457 Analyze_Allocator (N);
460 -- Ada 2005, AI-363: if the designated type has a constrained
461 -- partial view, it cannot receive a discriminant constraint,
462 -- and the allocated object is unconstrained.
464 elsif Ada_Version >= Ada_05
465 and then Has_Constrained_Partial_View (Base_Typ)
468 ("constraint no allowed when type " &
469 "has a constrained partial view", Constraint (E));
472 if Expander_Active then
474 Make_Defining_Identifier (Loc, New_Internal_Name ('S'));
477 Make_Subtype_Declaration (Loc,
478 Defining_Identifier => Def_Id,
479 Subtype_Indication => Relocate_Node (E)));
481 if Sav_Errs /= Serious_Errors_Detected
482 and then Nkind (Constraint (E)) =
483 N_Index_Or_Discriminant_Constraint
486 ("if qualified expression was meant, " &
487 "use apostrophe!", Constraint (E));
490 E := New_Occurrence_Of (Def_Id, Loc);
491 Rewrite (Expression (N), E);
495 Type_Id := Process_Subtype (E, N);
496 Acc_Type := Create_Itype (E_Allocator_Type, N);
497 Set_Etype (Acc_Type, Acc_Type);
498 Set_Directly_Designated_Type (Acc_Type, Type_Id);
499 Check_Fully_Declared (Type_Id, N);
503 if Can_Never_Be_Null (Type_Id) then
504 Error_Msg_N ("(Ada 2005) qualified expression required",
508 -- Check restriction against dynamically allocated protected
509 -- objects. Note that when limited aggregates are supported,
510 -- a similar test should be applied to an allocator with a
511 -- qualified expression ???
513 if Is_Protected_Type (Type_Id) then
514 Check_Restriction (No_Protected_Type_Allocators, N);
517 -- Check for missing initialization. Skip this check if we already
518 -- had errors on analyzing the allocator, since in that case these
519 -- are probably cascaded errors.
521 if Is_Indefinite_Subtype (Type_Id)
522 and then Serious_Errors_Detected = Sav_Errs
524 if Is_Class_Wide_Type (Type_Id) then
526 ("initialization required in class-wide allocation", N);
528 if Ada_Version < Ada_05
529 and then Is_Limited_Type (Type_Id)
531 Error_Msg_N ("unconstrained allocation not allowed", N);
533 if Is_Array_Type (Type_Id) then
535 ("\constraint with array bounds required", N);
537 elsif Has_Unknown_Discriminants (Type_Id) then
540 else pragma Assert (Has_Discriminants (Type_Id));
542 ("\constraint with discriminant values required", N);
545 -- Limited Ada 2005 and general non-limited case
549 ("uninitialized unconstrained allocation not allowed",
552 if Is_Array_Type (Type_Id) then
554 ("\qualified expression or constraint with " &
555 "array bounds required", N);
557 elsif Has_Unknown_Discriminants (Type_Id) then
558 Error_Msg_N ("\qualified expression required", N);
560 else pragma Assert (Has_Discriminants (Type_Id));
562 ("\qualified expression or constraint with " &
563 "discriminant values required", N);
571 if Is_Abstract_Type (Type_Id) then
572 Error_Msg_N ("cannot allocate abstract object", E);
575 if Has_Task (Designated_Type (Acc_Type)) then
576 Check_Restriction (No_Tasking, N);
577 Check_Restriction (Max_Tasks, N);
578 Check_Restriction (No_Task_Allocators, N);
581 -- If the No_Streams restriction is set, check that the type of the
582 -- object is not, and does not contain, any subtype derived from
583 -- Ada.Streams.Root_Stream_Type. Note that we guard the call to
584 -- Has_Stream just for efficiency reasons. There is no point in
585 -- spending time on a Has_Stream check if the restriction is not set.
587 if Restrictions.Set (No_Streams) then
588 if Has_Stream (Designated_Type (Acc_Type)) then
589 Check_Restriction (No_Streams, N);
593 Set_Etype (N, Acc_Type);
595 if not Is_Library_Level_Entity (Acc_Type) then
596 Check_Restriction (No_Local_Allocators, N);
599 if Serious_Errors_Detected > Sav_Errs then
600 Set_Error_Posted (N);
601 Set_Etype (N, Any_Type);
603 end Analyze_Allocator;
605 ---------------------------
606 -- Analyze_Arithmetic_Op --
607 ---------------------------
609 procedure Analyze_Arithmetic_Op (N : Node_Id) is
610 L : constant Node_Id := Left_Opnd (N);
611 R : constant Node_Id := Right_Opnd (N);
615 Candidate_Type := Empty;
616 Analyze_Expression (L);
617 Analyze_Expression (R);
619 -- If the entity is already set, the node is the instantiation of a
620 -- generic node with a non-local reference, or was manufactured by a
621 -- call to Make_Op_xxx. In either case the entity is known to be valid,
622 -- and we do not need to collect interpretations, instead we just get
623 -- the single possible interpretation.
627 if Present (Op_Id) then
628 if Ekind (Op_Id) = E_Operator then
630 if Nkind_In (N, N_Op_Divide, N_Op_Mod, N_Op_Multiply, N_Op_Rem)
631 and then Treat_Fixed_As_Integer (N)
635 Set_Etype (N, Any_Type);
636 Find_Arithmetic_Types (L, R, Op_Id, N);
640 Set_Etype (N, Any_Type);
641 Add_One_Interp (N, Op_Id, Etype (Op_Id));
644 -- Entity is not already set, so we do need to collect interpretations
647 Op_Id := Get_Name_Entity_Id (Chars (N));
648 Set_Etype (N, Any_Type);
650 while Present (Op_Id) loop
651 if Ekind (Op_Id) = E_Operator
652 and then Present (Next_Entity (First_Entity (Op_Id)))
654 Find_Arithmetic_Types (L, R, Op_Id, N);
656 -- The following may seem superfluous, because an operator cannot
657 -- be generic, but this ignores the cleverness of the author of
660 elsif Is_Overloadable (Op_Id) then
661 Analyze_User_Defined_Binary_Op (N, Op_Id);
664 Op_Id := Homonym (Op_Id);
669 end Analyze_Arithmetic_Op;
675 -- Function, procedure, and entry calls are checked here. The Name in
676 -- the call may be overloaded. The actuals have been analyzed and may
677 -- themselves be overloaded. On exit from this procedure, the node N
678 -- may have zero, one or more interpretations. In the first case an
679 -- error message is produced. In the last case, the node is flagged
680 -- as overloaded and the interpretations are collected in All_Interp.
682 -- If the name is an Access_To_Subprogram, it cannot be overloaded, but
683 -- the type-checking is similar to that of other calls.
685 procedure Analyze_Call (N : Node_Id) is
686 Actuals : constant List_Id := Parameter_Associations (N);
687 Nam : Node_Id := Name (N);
691 Success : Boolean := False;
693 function Name_Denotes_Function return Boolean;
694 -- If the type of the name is an access to subprogram, this may be
695 -- the type of a name, or the return type of the function being called.
696 -- If the name is not an entity then it can denote a protected function.
697 -- Until we distinguish Etype from Return_Type, we must use this
698 -- routine to resolve the meaning of the name in the call.
700 ---------------------------
701 -- Name_Denotes_Function --
702 ---------------------------
704 function Name_Denotes_Function return Boolean is
706 if Is_Entity_Name (Nam) then
707 return Ekind (Entity (Nam)) = E_Function;
709 elsif Nkind (Nam) = N_Selected_Component then
710 return Ekind (Entity (Selector_Name (Nam))) = E_Function;
715 end Name_Denotes_Function;
717 -- Start of processing for Analyze_Call
720 -- Initialize the type of the result of the call to the error type,
721 -- which will be reset if the type is successfully resolved.
723 Set_Etype (N, Any_Type);
725 if not Is_Overloaded (Nam) then
727 -- Only one interpretation to check
729 if Ekind (Etype (Nam)) = E_Subprogram_Type then
730 Nam_Ent := Etype (Nam);
732 -- If the prefix is an access_to_subprogram, this may be an indirect
733 -- call. This is the case if the name in the call is not an entity
734 -- name, or if it is a function name in the context of a procedure
735 -- call. In this latter case, we have a call to a parameterless
736 -- function that returns a pointer_to_procedure which is the entity
739 elsif Is_Access_Type (Etype (Nam))
740 and then Ekind (Designated_Type (Etype (Nam))) = E_Subprogram_Type
742 (not Name_Denotes_Function
743 or else Nkind (N) = N_Procedure_Call_Statement)
745 Nam_Ent := Designated_Type (Etype (Nam));
746 Insert_Explicit_Dereference (Nam);
748 -- Selected component case. Simple entry or protected operation,
749 -- where the entry name is given by the selector name.
751 elsif Nkind (Nam) = N_Selected_Component then
752 Nam_Ent := Entity (Selector_Name (Nam));
754 if Ekind (Nam_Ent) /= E_Entry
755 and then Ekind (Nam_Ent) /= E_Entry_Family
756 and then Ekind (Nam_Ent) /= E_Function
757 and then Ekind (Nam_Ent) /= E_Procedure
759 Error_Msg_N ("name in call is not a callable entity", Nam);
760 Set_Etype (N, Any_Type);
764 -- If the name is an Indexed component, it can be a call to a member
765 -- of an entry family. The prefix must be a selected component whose
766 -- selector is the entry. Analyze_Procedure_Call normalizes several
767 -- kinds of call into this form.
769 elsif Nkind (Nam) = N_Indexed_Component then
770 if Nkind (Prefix (Nam)) = N_Selected_Component then
771 Nam_Ent := Entity (Selector_Name (Prefix (Nam)));
773 Error_Msg_N ("name in call is not a callable entity", Nam);
774 Set_Etype (N, Any_Type);
778 elsif not Is_Entity_Name (Nam) then
779 Error_Msg_N ("name in call is not a callable entity", Nam);
780 Set_Etype (N, Any_Type);
784 Nam_Ent := Entity (Nam);
786 -- If no interpretations, give error message
788 if not Is_Overloadable (Nam_Ent) then
790 L : constant Boolean := Is_List_Member (N);
791 K : constant Node_Kind := Nkind (Parent (N));
794 -- If the node is in a list whose parent is not an
795 -- expression then it must be an attempted procedure call.
797 if L and then K not in N_Subexpr then
798 if Ekind (Entity (Nam)) = E_Generic_Procedure then
800 ("must instantiate generic procedure& before call",
804 ("procedure or entry name expected", Nam);
807 -- Check for tasking cases where only an entry call will do
810 and then Nkind_In (K, N_Entry_Call_Alternative,
811 N_Triggering_Alternative)
813 Error_Msg_N ("entry name expected", Nam);
815 -- Otherwise give general error message
818 Error_Msg_N ("invalid prefix in call", Nam);
826 Analyze_One_Call (N, Nam_Ent, True, Success);
828 -- If this is an indirect call, the return type of the access_to
829 -- subprogram may be an incomplete type. At the point of the call,
830 -- use the full type if available, and at the same time update
831 -- the return type of the access_to_subprogram.
834 and then Nkind (Nam) = N_Explicit_Dereference
835 and then Ekind (Etype (N)) = E_Incomplete_Type
836 and then Present (Full_View (Etype (N)))
838 Set_Etype (N, Full_View (Etype (N)));
839 Set_Etype (Nam_Ent, Etype (N));
843 -- An overloaded selected component must denote overloaded
844 -- operations of a concurrent type. The interpretations are
845 -- attached to the simple name of those operations.
847 if Nkind (Nam) = N_Selected_Component then
848 Nam := Selector_Name (Nam);
851 Get_First_Interp (Nam, X, It);
853 while Present (It.Nam) loop
856 -- Name may be call that returns an access to subprogram, or more
857 -- generally an overloaded expression one of whose interpretations
858 -- yields an access to subprogram. If the name is an entity, we
859 -- do not dereference, because the node is a call that returns
860 -- the access type: note difference between f(x), where the call
861 -- may return an access subprogram type, and f(x)(y), where the
862 -- type returned by the call to f is implicitly dereferenced to
863 -- analyze the outer call.
865 if Is_Access_Type (Nam_Ent) then
866 Nam_Ent := Designated_Type (Nam_Ent);
868 elsif Is_Access_Type (Etype (Nam_Ent))
869 and then not Is_Entity_Name (Nam)
870 and then Ekind (Designated_Type (Etype (Nam_Ent)))
873 Nam_Ent := Designated_Type (Etype (Nam_Ent));
876 Analyze_One_Call (N, Nam_Ent, False, Success);
878 -- If the interpretation succeeds, mark the proper type of the
879 -- prefix (any valid candidate will do). If not, remove the
880 -- candidate interpretation. This only needs to be done for
881 -- overloaded protected operations, for other entities disambi-
882 -- guation is done directly in Resolve.
885 Set_Etype (Nam, It.Typ);
887 elsif Nkind_In (Name (N), N_Selected_Component,
893 Get_Next_Interp (X, It);
896 -- If the name is the result of a function call, it can only
897 -- be a call to a function returning an access to subprogram.
898 -- Insert explicit dereference.
900 if Nkind (Nam) = N_Function_Call then
901 Insert_Explicit_Dereference (Nam);
904 if Etype (N) = Any_Type then
906 -- None of the interpretations is compatible with the actuals
908 Diagnose_Call (N, Nam);
910 -- Special checks for uninstantiated put routines
912 if Nkind (N) = N_Procedure_Call_Statement
913 and then Is_Entity_Name (Nam)
914 and then Chars (Nam) = Name_Put
915 and then List_Length (Actuals) = 1
918 Arg : constant Node_Id := First (Actuals);
922 if Nkind (Arg) = N_Parameter_Association then
923 Typ := Etype (Explicit_Actual_Parameter (Arg));
928 if Is_Signed_Integer_Type (Typ) then
930 ("possible missing instantiation of " &
931 "'Text_'I'O.'Integer_'I'O!", Nam);
933 elsif Is_Modular_Integer_Type (Typ) then
935 ("possible missing instantiation of " &
936 "'Text_'I'O.'Modular_'I'O!", Nam);
938 elsif Is_Floating_Point_Type (Typ) then
940 ("possible missing instantiation of " &
941 "'Text_'I'O.'Float_'I'O!", Nam);
943 elsif Is_Ordinary_Fixed_Point_Type (Typ) then
945 ("possible missing instantiation of " &
946 "'Text_'I'O.'Fixed_'I'O!", Nam);
948 elsif Is_Decimal_Fixed_Point_Type (Typ) then
950 ("possible missing instantiation of " &
951 "'Text_'I'O.'Decimal_'I'O!", Nam);
953 elsif Is_Enumeration_Type (Typ) then
955 ("possible missing instantiation of " &
956 "'Text_'I'O.'Enumeration_'I'O!", Nam);
961 elsif not Is_Overloaded (N)
962 and then Is_Entity_Name (Nam)
964 -- Resolution yields a single interpretation. Verify that the
965 -- reference has capitalization consistent with the declaration.
967 Set_Entity_With_Style_Check (Nam, Entity (Nam));
968 Generate_Reference (Entity (Nam), Nam);
970 Set_Etype (Nam, Etype (Entity (Nam)));
972 Remove_Abstract_Operations (N);
979 ---------------------------
980 -- Analyze_Comparison_Op --
981 ---------------------------
983 procedure Analyze_Comparison_Op (N : Node_Id) is
984 L : constant Node_Id := Left_Opnd (N);
985 R : constant Node_Id := Right_Opnd (N);
986 Op_Id : Entity_Id := Entity (N);
989 Set_Etype (N, Any_Type);
990 Candidate_Type := Empty;
992 Analyze_Expression (L);
993 Analyze_Expression (R);
995 if Present (Op_Id) then
996 if Ekind (Op_Id) = E_Operator then
997 Find_Comparison_Types (L, R, Op_Id, N);
999 Add_One_Interp (N, Op_Id, Etype (Op_Id));
1002 if Is_Overloaded (L) then
1003 Set_Etype (L, Intersect_Types (L, R));
1007 Op_Id := Get_Name_Entity_Id (Chars (N));
1008 while Present (Op_Id) loop
1009 if Ekind (Op_Id) = E_Operator then
1010 Find_Comparison_Types (L, R, Op_Id, N);
1012 Analyze_User_Defined_Binary_Op (N, Op_Id);
1015 Op_Id := Homonym (Op_Id);
1020 end Analyze_Comparison_Op;
1022 ---------------------------
1023 -- Analyze_Concatenation --
1024 ---------------------------
1026 procedure Analyze_Concatenation (N : Node_Id) is
1028 -- We wish to avoid deep recursion, because concatenations are often
1029 -- deeply nested, as in A&B&...&Z. Therefore, we walk down the left
1030 -- operands nonrecursively until we find something that is not a
1031 -- concatenation (A in this case), or has already been analyzed. We
1032 -- analyze that, and then walk back up the tree following Parent
1033 -- pointers, calling Analyze_Concatenation_Rest to do the rest of the
1034 -- work at each level. The Parent pointers allow us to avoid recursion,
1035 -- and thus avoid running out of memory.
1041 Candidate_Type := Empty;
1043 -- The following code is equivalent to:
1045 -- Set_Etype (N, Any_Type);
1046 -- Analyze_Expression (Left_Opnd (N));
1047 -- Analyze_Concatenation_Rest (N);
1049 -- where the Analyze_Expression call recurses back here if the left
1050 -- operand is a concatenation.
1052 -- Walk down left operands
1055 Set_Etype (NN, Any_Type);
1056 L := Left_Opnd (NN);
1057 exit when Nkind (L) /= N_Op_Concat or else Analyzed (L);
1061 -- Now (given the above example) NN is A&B and L is A
1063 -- First analyze L ...
1065 Analyze_Expression (L);
1067 -- ... then walk NN back up until we reach N (where we started), calling
1068 -- Analyze_Concatenation_Rest along the way.
1071 Analyze_Concatenation_Rest (NN);
1075 end Analyze_Concatenation;
1077 --------------------------------
1078 -- Analyze_Concatenation_Rest --
1079 --------------------------------
1081 -- If the only one-dimensional array type in scope is String,
1082 -- this is the resulting type of the operation. Otherwise there
1083 -- will be a concatenation operation defined for each user-defined
1084 -- one-dimensional array.
1086 procedure Analyze_Concatenation_Rest (N : Node_Id) is
1087 L : constant Node_Id := Left_Opnd (N);
1088 R : constant Node_Id := Right_Opnd (N);
1089 Op_Id : Entity_Id := Entity (N);
1094 Analyze_Expression (R);
1096 -- If the entity is present, the node appears in an instance, and
1097 -- denotes a predefined concatenation operation. The resulting type is
1098 -- obtained from the arguments when possible. If the arguments are
1099 -- aggregates, the array type and the concatenation type must be
1102 if Present (Op_Id) then
1103 if Ekind (Op_Id) = E_Operator then
1105 LT := Base_Type (Etype (L));
1106 RT := Base_Type (Etype (R));
1108 if Is_Array_Type (LT)
1109 and then (RT = LT or else RT = Base_Type (Component_Type (LT)))
1111 Add_One_Interp (N, Op_Id, LT);
1113 elsif Is_Array_Type (RT)
1114 and then LT = Base_Type (Component_Type (RT))
1116 Add_One_Interp (N, Op_Id, RT);
1118 -- If one operand is a string type or a user-defined array type,
1119 -- and the other is a literal, result is of the specific type.
1122 (Root_Type (LT) = Standard_String
1123 or else Scope (LT) /= Standard_Standard)
1124 and then Etype (R) = Any_String
1126 Add_One_Interp (N, Op_Id, LT);
1129 (Root_Type (RT) = Standard_String
1130 or else Scope (RT) /= Standard_Standard)
1131 and then Etype (L) = Any_String
1133 Add_One_Interp (N, Op_Id, RT);
1135 elsif not Is_Generic_Type (Etype (Op_Id)) then
1136 Add_One_Interp (N, Op_Id, Etype (Op_Id));
1139 -- Type and its operations must be visible
1141 Set_Entity (N, Empty);
1142 Analyze_Concatenation (N);
1146 Add_One_Interp (N, Op_Id, Etype (Op_Id));
1150 Op_Id := Get_Name_Entity_Id (Name_Op_Concat);
1151 while Present (Op_Id) loop
1152 if Ekind (Op_Id) = E_Operator then
1154 -- Do not consider operators declared in dead code, they can
1155 -- not be part of the resolution.
1157 if Is_Eliminated (Op_Id) then
1160 Find_Concatenation_Types (L, R, Op_Id, N);
1164 Analyze_User_Defined_Binary_Op (N, Op_Id);
1167 Op_Id := Homonym (Op_Id);
1172 end Analyze_Concatenation_Rest;
1174 ------------------------------------
1175 -- Analyze_Conditional_Expression --
1176 ------------------------------------
1178 procedure Analyze_Conditional_Expression (N : Node_Id) is
1179 Condition : constant Node_Id := First (Expressions (N));
1180 Then_Expr : constant Node_Id := Next (Condition);
1181 Else_Expr : constant Node_Id := Next (Then_Expr);
1183 Analyze_Expression (Condition);
1184 Analyze_Expression (Then_Expr);
1185 Analyze_Expression (Else_Expr);
1186 Set_Etype (N, Etype (Then_Expr));
1187 end Analyze_Conditional_Expression;
1189 -------------------------
1190 -- Analyze_Equality_Op --
1191 -------------------------
1193 procedure Analyze_Equality_Op (N : Node_Id) is
1194 Loc : constant Source_Ptr := Sloc (N);
1195 L : constant Node_Id := Left_Opnd (N);
1196 R : constant Node_Id := Right_Opnd (N);
1200 Set_Etype (N, Any_Type);
1201 Candidate_Type := Empty;
1203 Analyze_Expression (L);
1204 Analyze_Expression (R);
1206 -- If the entity is set, the node is a generic instance with a non-local
1207 -- reference to the predefined operator or to a user-defined function.
1208 -- It can also be an inequality that is expanded into the negation of a
1209 -- call to a user-defined equality operator.
1211 -- For the predefined case, the result is Boolean, regardless of the
1212 -- type of the operands. The operands may even be limited, if they are
1213 -- generic actuals. If they are overloaded, label the left argument with
1214 -- the common type that must be present, or with the type of the formal
1215 -- of the user-defined function.
1217 if Present (Entity (N)) then
1218 Op_Id := Entity (N);
1220 if Ekind (Op_Id) = E_Operator then
1221 Add_One_Interp (N, Op_Id, Standard_Boolean);
1223 Add_One_Interp (N, Op_Id, Etype (Op_Id));
1226 if Is_Overloaded (L) then
1227 if Ekind (Op_Id) = E_Operator then
1228 Set_Etype (L, Intersect_Types (L, R));
1230 Set_Etype (L, Etype (First_Formal (Op_Id)));
1235 Op_Id := Get_Name_Entity_Id (Chars (N));
1236 while Present (Op_Id) loop
1237 if Ekind (Op_Id) = E_Operator then
1238 Find_Equality_Types (L, R, Op_Id, N);
1240 Analyze_User_Defined_Binary_Op (N, Op_Id);
1243 Op_Id := Homonym (Op_Id);
1247 -- If there was no match, and the operator is inequality, this may
1248 -- be a case where inequality has not been made explicit, as for
1249 -- tagged types. Analyze the node as the negation of an equality
1250 -- operation. This cannot be done earlier, because before analysis
1251 -- we cannot rule out the presence of an explicit inequality.
1253 if Etype (N) = Any_Type
1254 and then Nkind (N) = N_Op_Ne
1256 Op_Id := Get_Name_Entity_Id (Name_Op_Eq);
1257 while Present (Op_Id) loop
1258 if Ekind (Op_Id) = E_Operator then
1259 Find_Equality_Types (L, R, Op_Id, N);
1261 Analyze_User_Defined_Binary_Op (N, Op_Id);
1264 Op_Id := Homonym (Op_Id);
1267 if Etype (N) /= Any_Type then
1268 Op_Id := Entity (N);
1274 Left_Opnd => Left_Opnd (N),
1275 Right_Opnd => Right_Opnd (N))));
1277 Set_Entity (Right_Opnd (N), Op_Id);
1283 end Analyze_Equality_Op;
1285 ----------------------------------
1286 -- Analyze_Explicit_Dereference --
1287 ----------------------------------
1289 procedure Analyze_Explicit_Dereference (N : Node_Id) is
1290 Loc : constant Source_Ptr := Sloc (N);
1291 P : constant Node_Id := Prefix (N);
1297 function Is_Function_Type return Boolean;
1298 -- Check whether node may be interpreted as an implicit function call
1300 ----------------------
1301 -- Is_Function_Type --
1302 ----------------------
1304 function Is_Function_Type return Boolean is
1309 if not Is_Overloaded (N) then
1310 return Ekind (Base_Type (Etype (N))) = E_Subprogram_Type
1311 and then Etype (Base_Type (Etype (N))) /= Standard_Void_Type;
1314 Get_First_Interp (N, I, It);
1315 while Present (It.Nam) loop
1316 if Ekind (Base_Type (It.Typ)) /= E_Subprogram_Type
1317 or else Etype (Base_Type (It.Typ)) = Standard_Void_Type
1322 Get_Next_Interp (I, It);
1327 end Is_Function_Type;
1329 -- Start of processing for Analyze_Explicit_Dereference
1333 Set_Etype (N, Any_Type);
1335 -- Test for remote access to subprogram type, and if so return
1336 -- after rewriting the original tree.
1338 if Remote_AST_E_Dereference (P) then
1342 -- Normal processing for other than remote access to subprogram type
1344 if not Is_Overloaded (P) then
1345 if Is_Access_Type (Etype (P)) then
1347 -- Set the Etype. We need to go thru Is_For_Access_Subtypes to
1348 -- avoid other problems caused by the Private_Subtype and it is
1349 -- safe to go to the Base_Type because this is the same as
1350 -- converting the access value to its Base_Type.
1353 DT : Entity_Id := Designated_Type (Etype (P));
1356 if Ekind (DT) = E_Private_Subtype
1357 and then Is_For_Access_Subtype (DT)
1359 DT := Base_Type (DT);
1362 -- An explicit dereference is a legal occurrence of an
1363 -- incomplete type imported through a limited_with clause,
1364 -- if the full view is visible.
1366 if From_With_Type (DT)
1367 and then not From_With_Type (Scope (DT))
1369 (Is_Immediately_Visible (Scope (DT))
1371 (Is_Child_Unit (Scope (DT))
1372 and then Is_Visible_Child_Unit (Scope (DT))))
1374 Set_Etype (N, Available_View (DT));
1381 elsif Etype (P) /= Any_Type then
1382 Error_Msg_N ("prefix of dereference must be an access type", N);
1387 Get_First_Interp (P, I, It);
1388 while Present (It.Nam) loop
1391 if Is_Access_Type (T) then
1392 Add_One_Interp (N, Designated_Type (T), Designated_Type (T));
1395 Get_Next_Interp (I, It);
1398 -- Error if no interpretation of the prefix has an access type
1400 if Etype (N) = Any_Type then
1402 ("access type required in prefix of explicit dereference", P);
1403 Set_Etype (N, Any_Type);
1409 and then Nkind (Parent (N)) /= N_Indexed_Component
1411 and then (Nkind (Parent (N)) /= N_Function_Call
1412 or else N /= Name (Parent (N)))
1414 and then (Nkind (Parent (N)) /= N_Procedure_Call_Statement
1415 or else N /= Name (Parent (N)))
1417 and then Nkind (Parent (N)) /= N_Subprogram_Renaming_Declaration
1418 and then (Nkind (Parent (N)) /= N_Attribute_Reference
1420 (Attribute_Name (Parent (N)) /= Name_Address
1422 Attribute_Name (Parent (N)) /= Name_Access))
1424 -- Name is a function call with no actuals, in a context that
1425 -- requires deproceduring (including as an actual in an enclosing
1426 -- function or procedure call). There are some pathological cases
1427 -- where the prefix might include functions that return access to
1428 -- subprograms and others that return a regular type. Disambiguation
1429 -- of those has to take place in Resolve.
1432 Make_Function_Call (Loc,
1433 Name => Make_Explicit_Dereference (Loc, P),
1434 Parameter_Associations => New_List);
1436 -- If the prefix is overloaded, remove operations that have formals,
1437 -- we know that this is a parameterless call.
1439 if Is_Overloaded (P) then
1440 Get_First_Interp (P, I, It);
1441 while Present (It.Nam) loop
1444 if No (First_Formal (Base_Type (Designated_Type (T)))) then
1450 Get_Next_Interp (I, It);
1457 elsif not Is_Function_Type
1458 and then Is_Overloaded (N)
1460 -- The prefix may include access to subprograms and other access
1461 -- types. If the context selects the interpretation that is a call,
1462 -- we cannot rewrite the node yet, but we include the result of
1463 -- the call interpretation.
1465 Get_First_Interp (N, I, It);
1466 while Present (It.Nam) loop
1467 if Ekind (Base_Type (It.Typ)) = E_Subprogram_Type
1468 and then Etype (Base_Type (It.Typ)) /= Standard_Void_Type
1470 Add_One_Interp (N, Etype (It.Typ), Etype (It.Typ));
1473 Get_Next_Interp (I, It);
1477 -- A value of remote access-to-class-wide must not be dereferenced
1480 Validate_Remote_Access_To_Class_Wide_Type (N);
1481 end Analyze_Explicit_Dereference;
1483 ------------------------
1484 -- Analyze_Expression --
1485 ------------------------
1487 procedure Analyze_Expression (N : Node_Id) is
1490 Check_Parameterless_Call (N);
1491 end Analyze_Expression;
1493 ------------------------------------
1494 -- Analyze_Indexed_Component_Form --
1495 ------------------------------------
1497 procedure Analyze_Indexed_Component_Form (N : Node_Id) is
1498 P : constant Node_Id := Prefix (N);
1499 Exprs : constant List_Id := Expressions (N);
1505 procedure Process_Function_Call;
1506 -- Prefix in indexed component form is an overloadable entity,
1507 -- so the node is a function call. Reformat it as such.
1509 procedure Process_Indexed_Component;
1510 -- Prefix in indexed component form is actually an indexed component.
1511 -- This routine processes it, knowing that the prefix is already
1514 procedure Process_Indexed_Component_Or_Slice;
1515 -- An indexed component with a single index may designate a slice if
1516 -- the index is a subtype mark. This routine disambiguates these two
1517 -- cases by resolving the prefix to see if it is a subtype mark.
1519 procedure Process_Overloaded_Indexed_Component;
1520 -- If the prefix of an indexed component is overloaded, the proper
1521 -- interpretation is selected by the index types and the context.
1523 ---------------------------
1524 -- Process_Function_Call --
1525 ---------------------------
1527 procedure Process_Function_Call is
1531 Change_Node (N, N_Function_Call);
1533 Set_Parameter_Associations (N, Exprs);
1535 -- Analyze actuals prior to analyzing the call itself
1537 Actual := First (Parameter_Associations (N));
1538 while Present (Actual) loop
1540 Check_Parameterless_Call (Actual);
1542 -- Move to next actual. Note that we use Next, not Next_Actual
1543 -- here. The reason for this is a bit subtle. If a function call
1544 -- includes named associations, the parser recognizes the node as
1545 -- a call, and it is analyzed as such. If all associations are
1546 -- positional, the parser builds an indexed_component node, and
1547 -- it is only after analysis of the prefix that the construct
1548 -- is recognized as a call, in which case Process_Function_Call
1549 -- rewrites the node and analyzes the actuals. If the list of
1550 -- actuals is malformed, the parser may leave the node as an
1551 -- indexed component (despite the presence of named associations).
1552 -- The iterator Next_Actual is equivalent to Next if the list is
1553 -- positional, but follows the normalized chain of actuals when
1554 -- named associations are present. In this case normalization has
1555 -- not taken place, and actuals remain unanalyzed, which leads to
1556 -- subsequent crashes or loops if there is an attempt to continue
1557 -- analysis of the program.
1563 end Process_Function_Call;
1565 -------------------------------
1566 -- Process_Indexed_Component --
1567 -------------------------------
1569 procedure Process_Indexed_Component is
1571 Array_Type : Entity_Id;
1573 Pent : Entity_Id := Empty;
1576 Exp := First (Exprs);
1578 if Is_Overloaded (P) then
1579 Process_Overloaded_Indexed_Component;
1582 Array_Type := Etype (P);
1584 if Is_Entity_Name (P) then
1586 elsif Nkind (P) = N_Selected_Component
1587 and then Is_Entity_Name (Selector_Name (P))
1589 Pent := Entity (Selector_Name (P));
1592 -- Prefix must be appropriate for an array type, taking into
1593 -- account a possible implicit dereference.
1595 if Is_Access_Type (Array_Type) then
1596 Error_Msg_NW (Warn_On_Dereference, "?implicit dereference", N);
1597 Array_Type := Process_Implicit_Dereference_Prefix (Pent, P);
1600 if Is_Array_Type (Array_Type) then
1603 elsif Present (Pent) and then Ekind (Pent) = E_Entry_Family then
1605 Set_Etype (N, Any_Type);
1607 if not Has_Compatible_Type
1608 (Exp, Entry_Index_Type (Pent))
1610 Error_Msg_N ("invalid index type in entry name", N);
1612 elsif Present (Next (Exp)) then
1613 Error_Msg_N ("too many subscripts in entry reference", N);
1616 Set_Etype (N, Etype (P));
1621 elsif Is_Record_Type (Array_Type)
1622 and then Remote_AST_I_Dereference (P)
1626 elsif Array_Type = Any_Type then
1627 Set_Etype (N, Any_Type);
1630 -- Here we definitely have a bad indexing
1633 if Nkind (Parent (N)) = N_Requeue_Statement
1634 and then Present (Pent) and then Ekind (Pent) = E_Entry
1637 ("REQUEUE does not permit parameters", First (Exprs));
1639 elsif Is_Entity_Name (P)
1640 and then Etype (P) = Standard_Void_Type
1642 Error_Msg_NE ("incorrect use of&", P, Entity (P));
1645 Error_Msg_N ("array type required in indexed component", P);
1648 Set_Etype (N, Any_Type);
1652 Index := First_Index (Array_Type);
1653 while Present (Index) and then Present (Exp) loop
1654 if not Has_Compatible_Type (Exp, Etype (Index)) then
1655 Wrong_Type (Exp, Etype (Index));
1656 Set_Etype (N, Any_Type);
1664 Set_Etype (N, Component_Type (Array_Type));
1666 if Present (Index) then
1668 ("too few subscripts in array reference", First (Exprs));
1670 elsif Present (Exp) then
1671 Error_Msg_N ("too many subscripts in array reference", Exp);
1674 end Process_Indexed_Component;
1676 ----------------------------------------
1677 -- Process_Indexed_Component_Or_Slice --
1678 ----------------------------------------
1680 procedure Process_Indexed_Component_Or_Slice is
1682 Exp := First (Exprs);
1683 while Present (Exp) loop
1684 Analyze_Expression (Exp);
1688 Exp := First (Exprs);
1690 -- If one index is present, and it is a subtype name, then the
1691 -- node denotes a slice (note that the case of an explicit range
1692 -- for a slice was already built as an N_Slice node in the first
1693 -- place, so that case is not handled here).
1695 -- We use a replace rather than a rewrite here because this is one
1696 -- of the cases in which the tree built by the parser is plain wrong.
1699 and then Is_Entity_Name (Exp)
1700 and then Is_Type (Entity (Exp))
1703 Make_Slice (Sloc (N),
1705 Discrete_Range => New_Copy (Exp)));
1708 -- Otherwise (more than one index present, or single index is not
1709 -- a subtype name), then we have the indexed component case.
1712 Process_Indexed_Component;
1714 end Process_Indexed_Component_Or_Slice;
1716 ------------------------------------------
1717 -- Process_Overloaded_Indexed_Component --
1718 ------------------------------------------
1720 procedure Process_Overloaded_Indexed_Component is
1729 Set_Etype (N, Any_Type);
1731 Get_First_Interp (P, I, It);
1732 while Present (It.Nam) loop
1735 if Is_Access_Type (Typ) then
1736 Typ := Designated_Type (Typ);
1737 Error_Msg_NW (Warn_On_Dereference, "?implicit dereference", N);
1740 if Is_Array_Type (Typ) then
1742 -- Got a candidate: verify that index types are compatible
1744 Index := First_Index (Typ);
1746 Exp := First (Exprs);
1747 while Present (Index) and then Present (Exp) loop
1748 if Has_Compatible_Type (Exp, Etype (Index)) then
1760 if Found and then No (Index) and then No (Exp) then
1762 Etype (Component_Type (Typ)),
1763 Etype (Component_Type (Typ)));
1767 Get_Next_Interp (I, It);
1770 if Etype (N) = Any_Type then
1771 Error_Msg_N ("no legal interpretation for indexed component", N);
1772 Set_Is_Overloaded (N, False);
1776 end Process_Overloaded_Indexed_Component;
1778 -- Start of processing for Analyze_Indexed_Component_Form
1781 -- Get name of array, function or type
1785 if Nkind_In (N, N_Function_Call, N_Procedure_Call_Statement) then
1787 -- If P is an explicit dereference whose prefix is of a
1788 -- remote access-to-subprogram type, then N has already
1789 -- been rewritten as a subprogram call and analyzed.
1794 pragma Assert (Nkind (N) = N_Indexed_Component);
1796 P_T := Base_Type (Etype (P));
1798 if Is_Entity_Name (P)
1799 or else Nkind (P) = N_Operator_Symbol
1803 if Is_Type (U_N) then
1805 -- Reformat node as a type conversion
1807 E := Remove_Head (Exprs);
1809 if Present (First (Exprs)) then
1811 ("argument of type conversion must be single expression", N);
1814 Change_Node (N, N_Type_Conversion);
1815 Set_Subtype_Mark (N, P);
1817 Set_Expression (N, E);
1819 -- After changing the node, call for the specific Analysis
1820 -- routine directly, to avoid a double call to the expander.
1822 Analyze_Type_Conversion (N);
1826 if Is_Overloadable (U_N) then
1827 Process_Function_Call;
1829 elsif Ekind (Etype (P)) = E_Subprogram_Type
1830 or else (Is_Access_Type (Etype (P))
1832 Ekind (Designated_Type (Etype (P))) = E_Subprogram_Type)
1834 -- Call to access_to-subprogram with possible implicit dereference
1836 Process_Function_Call;
1838 elsif Is_Generic_Subprogram (U_N) then
1840 -- A common beginner's (or C++ templates fan) error
1842 Error_Msg_N ("generic subprogram cannot be called", N);
1843 Set_Etype (N, Any_Type);
1847 Process_Indexed_Component_Or_Slice;
1850 -- If not an entity name, prefix is an expression that may denote
1851 -- an array or an access-to-subprogram.
1854 if Ekind (P_T) = E_Subprogram_Type
1855 or else (Is_Access_Type (P_T)
1857 Ekind (Designated_Type (P_T)) = E_Subprogram_Type)
1859 Process_Function_Call;
1861 elsif Nkind (P) = N_Selected_Component
1862 and then Is_Overloadable (Entity (Selector_Name (P)))
1864 Process_Function_Call;
1867 -- Indexed component, slice, or a call to a member of a family
1868 -- entry, which will be converted to an entry call later.
1870 Process_Indexed_Component_Or_Slice;
1873 end Analyze_Indexed_Component_Form;
1875 ------------------------
1876 -- Analyze_Logical_Op --
1877 ------------------------
1879 procedure Analyze_Logical_Op (N : Node_Id) is
1880 L : constant Node_Id := Left_Opnd (N);
1881 R : constant Node_Id := Right_Opnd (N);
1882 Op_Id : Entity_Id := Entity (N);
1885 Set_Etype (N, Any_Type);
1886 Candidate_Type := Empty;
1888 Analyze_Expression (L);
1889 Analyze_Expression (R);
1891 if Present (Op_Id) then
1893 if Ekind (Op_Id) = E_Operator then
1894 Find_Boolean_Types (L, R, Op_Id, N);
1896 Add_One_Interp (N, Op_Id, Etype (Op_Id));
1900 Op_Id := Get_Name_Entity_Id (Chars (N));
1901 while Present (Op_Id) loop
1902 if Ekind (Op_Id) = E_Operator then
1903 Find_Boolean_Types (L, R, Op_Id, N);
1905 Analyze_User_Defined_Binary_Op (N, Op_Id);
1908 Op_Id := Homonym (Op_Id);
1913 end Analyze_Logical_Op;
1915 ---------------------------
1916 -- Analyze_Membership_Op --
1917 ---------------------------
1919 procedure Analyze_Membership_Op (N : Node_Id) is
1920 L : constant Node_Id := Left_Opnd (N);
1921 R : constant Node_Id := Right_Opnd (N);
1923 Index : Interp_Index;
1925 Found : Boolean := False;
1929 procedure Try_One_Interp (T1 : Entity_Id);
1930 -- Routine to try one proposed interpretation. Note that the context
1931 -- of the operation plays no role in resolving the arguments, so that
1932 -- if there is more than one interpretation of the operands that is
1933 -- compatible with a membership test, the operation is ambiguous.
1935 --------------------
1936 -- Try_One_Interp --
1937 --------------------
1939 procedure Try_One_Interp (T1 : Entity_Id) is
1941 if Has_Compatible_Type (R, T1) then
1943 and then Base_Type (T1) /= Base_Type (T_F)
1945 It := Disambiguate (L, I_F, Index, Any_Type);
1947 if It = No_Interp then
1948 Ambiguous_Operands (N);
1949 Set_Etype (L, Any_Type);
1967 -- Start of processing for Analyze_Membership_Op
1970 Analyze_Expression (L);
1972 if Nkind (R) = N_Range
1973 or else (Nkind (R) = N_Attribute_Reference
1974 and then Attribute_Name (R) = Name_Range)
1978 if not Is_Overloaded (L) then
1979 Try_One_Interp (Etype (L));
1982 Get_First_Interp (L, Index, It);
1983 while Present (It.Typ) loop
1984 Try_One_Interp (It.Typ);
1985 Get_Next_Interp (Index, It);
1989 -- If not a range, it can only be a subtype mark, or else there
1990 -- is a more basic error, to be diagnosed in Find_Type.
1995 if Is_Entity_Name (R) then
1996 Check_Fully_Declared (Entity (R), R);
2000 -- Compatibility between expression and subtype mark or range is
2001 -- checked during resolution. The result of the operation is Boolean
2004 Set_Etype (N, Standard_Boolean);
2006 if Comes_From_Source (N)
2007 and then Is_CPP_Class (Etype (Etype (Right_Opnd (N))))
2009 Error_Msg_N ("membership test not applicable to cpp-class types", N);
2011 end Analyze_Membership_Op;
2013 ----------------------
2014 -- Analyze_Negation --
2015 ----------------------
2017 procedure Analyze_Negation (N : Node_Id) is
2018 R : constant Node_Id := Right_Opnd (N);
2019 Op_Id : Entity_Id := Entity (N);
2022 Set_Etype (N, Any_Type);
2023 Candidate_Type := Empty;
2025 Analyze_Expression (R);
2027 if Present (Op_Id) then
2028 if Ekind (Op_Id) = E_Operator then
2029 Find_Negation_Types (R, Op_Id, N);
2031 Add_One_Interp (N, Op_Id, Etype (Op_Id));
2035 Op_Id := Get_Name_Entity_Id (Chars (N));
2036 while Present (Op_Id) loop
2037 if Ekind (Op_Id) = E_Operator then
2038 Find_Negation_Types (R, Op_Id, N);
2040 Analyze_User_Defined_Unary_Op (N, Op_Id);
2043 Op_Id := Homonym (Op_Id);
2048 end Analyze_Negation;
2054 procedure Analyze_Null (N : Node_Id) is
2056 Set_Etype (N, Any_Access);
2059 ----------------------
2060 -- Analyze_One_Call --
2061 ----------------------
2063 procedure Analyze_One_Call
2067 Success : out Boolean;
2068 Skip_First : Boolean := False)
2070 Actuals : constant List_Id := Parameter_Associations (N);
2071 Prev_T : constant Entity_Id := Etype (N);
2073 Must_Skip : constant Boolean := Skip_First
2074 or else Nkind (Original_Node (N)) = N_Selected_Component
2076 (Nkind (Original_Node (N)) = N_Indexed_Component
2077 and then Nkind (Prefix (Original_Node (N)))
2078 = N_Selected_Component);
2079 -- The first formal must be omitted from the match when trying to find
2080 -- a primitive operation that is a possible interpretation, and also
2081 -- after the call has been rewritten, because the corresponding actual
2082 -- is already known to be compatible, and because this may be an
2083 -- indexing of a call with default parameters.
2087 Is_Indexed : Boolean := False;
2088 Subp_Type : constant Entity_Id := Etype (Nam);
2091 function Operator_Hidden_By (Fun : Entity_Id) return Boolean;
2092 -- There may be a user-defined operator that hides the current
2093 -- interpretation. We must check for this independently of the
2094 -- analysis of the call with the user-defined operation, because
2095 -- the parameter names may be wrong and yet the hiding takes place.
2096 -- This fixes a problem with ACATS test B34014O.
2098 -- When the type Address is a visible integer type, and the DEC
2099 -- system extension is visible, the predefined operator may be
2100 -- hidden as well, by one of the address operations in auxdec.
2101 -- Finally, The abstract operations on address do not hide the
2102 -- predefined operator (this is the purpose of making them abstract).
2104 procedure Indicate_Name_And_Type;
2105 -- If candidate interpretation matches, indicate name and type of
2106 -- result on call node.
2108 ----------------------------
2109 -- Indicate_Name_And_Type --
2110 ----------------------------
2112 procedure Indicate_Name_And_Type is
2114 Add_One_Interp (N, Nam, Etype (Nam));
2117 -- If the prefix of the call is a name, indicate the entity
2118 -- being called. If it is not a name, it is an expression that
2119 -- denotes an access to subprogram or else an entry or family. In
2120 -- the latter case, the name is a selected component, and the entity
2121 -- being called is noted on the selector.
2123 if not Is_Type (Nam) then
2124 if Is_Entity_Name (Name (N))
2125 or else Nkind (Name (N)) = N_Operator_Symbol
2127 Set_Entity (Name (N), Nam);
2129 elsif Nkind (Name (N)) = N_Selected_Component then
2130 Set_Entity (Selector_Name (Name (N)), Nam);
2134 if Debug_Flag_E and not Report then
2135 Write_Str (" Overloaded call ");
2136 Write_Int (Int (N));
2137 Write_Str (" compatible with ");
2138 Write_Int (Int (Nam));
2141 end Indicate_Name_And_Type;
2143 ------------------------
2144 -- Operator_Hidden_By --
2145 ------------------------
2147 function Operator_Hidden_By (Fun : Entity_Id) return Boolean is
2148 Act1 : constant Node_Id := First_Actual (N);
2149 Act2 : constant Node_Id := Next_Actual (Act1);
2150 Form1 : constant Entity_Id := First_Formal (Fun);
2151 Form2 : constant Entity_Id := Next_Formal (Form1);
2154 if Ekind (Fun) /= E_Function
2155 or else Is_Abstract_Subprogram (Fun)
2159 elsif not Has_Compatible_Type (Act1, Etype (Form1)) then
2162 elsif Present (Form2) then
2164 No (Act2) or else not Has_Compatible_Type (Act2, Etype (Form2))
2169 elsif Present (Act2) then
2173 -- Now we know that the arity of the operator matches the function,
2174 -- and the function call is a valid interpretation. The function
2175 -- hides the operator if it has the right signature, or if one of
2176 -- its operands is a non-abstract operation on Address when this is
2177 -- a visible integer type.
2179 return Hides_Op (Fun, Nam)
2180 or else Is_Descendent_Of_Address (Etype (Form1))
2183 and then Is_Descendent_Of_Address (Etype (Form2)));
2184 end Operator_Hidden_By;
2186 -- Start of processing for Analyze_One_Call
2191 -- If the subprogram has no formals or if all the formals have defaults,
2192 -- and the return type is an array type, the node may denote an indexing
2193 -- of the result of a parameterless call. In Ada 2005, the subprogram
2194 -- may have one non-defaulted formal, and the call may have been written
2195 -- in prefix notation, so that the rebuilt parameter list has more than
2198 if Present (Actuals)
2200 (Needs_No_Actuals (Nam)
2202 (Needs_One_Actual (Nam)
2203 and then Present (Next_Actual (First (Actuals)))))
2205 if Is_Array_Type (Subp_Type) then
2206 Is_Indexed := Try_Indexed_Call (N, Nam, Subp_Type, Must_Skip);
2208 elsif Is_Access_Type (Subp_Type)
2209 and then Is_Array_Type (Designated_Type (Subp_Type))
2213 (N, Nam, Designated_Type (Subp_Type), Must_Skip);
2215 -- The prefix can also be a parameterless function that returns an
2216 -- access to subprogram. in which case this is an indirect call.
2218 elsif Is_Access_Type (Subp_Type)
2219 and then Ekind (Designated_Type (Subp_Type)) = E_Subprogram_Type
2221 Is_Indexed := Try_Indirect_Call (N, Nam, Subp_Type);
2226 Normalize_Actuals (N, Nam, (Report and not Is_Indexed), Norm_OK);
2230 -- Mismatch in number or names of parameters
2232 if Debug_Flag_E then
2233 Write_Str (" normalization fails in call ");
2234 Write_Int (Int (N));
2235 Write_Str (" with subprogram ");
2236 Write_Int (Int (Nam));
2240 -- If the context expects a function call, discard any interpretation
2241 -- that is a procedure. If the node is not overloaded, leave as is for
2242 -- better error reporting when type mismatch is found.
2244 elsif Nkind (N) = N_Function_Call
2245 and then Is_Overloaded (Name (N))
2246 and then Ekind (Nam) = E_Procedure
2250 -- Ditto for function calls in a procedure context
2252 elsif Nkind (N) = N_Procedure_Call_Statement
2253 and then Is_Overloaded (Name (N))
2254 and then Etype (Nam) /= Standard_Void_Type
2258 elsif No (Actuals) then
2260 -- If Normalize succeeds, then there are default parameters for
2263 Indicate_Name_And_Type;
2265 elsif Ekind (Nam) = E_Operator then
2266 if Nkind (N) = N_Procedure_Call_Statement then
2270 -- This can occur when the prefix of the call is an operator
2271 -- name or an expanded name whose selector is an operator name.
2273 Analyze_Operator_Call (N, Nam);
2275 if Etype (N) /= Prev_T then
2277 -- Check that operator is not hidden by a function interpretation
2279 if Is_Overloaded (Name (N)) then
2285 Get_First_Interp (Name (N), I, It);
2286 while Present (It.Nam) loop
2287 if Operator_Hidden_By (It.Nam) then
2288 Set_Etype (N, Prev_T);
2292 Get_Next_Interp (I, It);
2297 -- If operator matches formals, record its name on the call.
2298 -- If the operator is overloaded, Resolve will select the
2299 -- correct one from the list of interpretations. The call
2300 -- node itself carries the first candidate.
2302 Set_Entity (Name (N), Nam);
2305 elsif Report and then Etype (N) = Any_Type then
2306 Error_Msg_N ("incompatible arguments for operator", N);
2310 -- Normalize_Actuals has chained the named associations in the
2311 -- correct order of the formals.
2313 Actual := First_Actual (N);
2314 Formal := First_Formal (Nam);
2316 -- If we are analyzing a call rewritten from object notation,
2317 -- skip first actual, which may be rewritten later as an
2318 -- explicit dereference.
2321 Next_Actual (Actual);
2322 Next_Formal (Formal);
2325 while Present (Actual) and then Present (Formal) loop
2326 if Nkind (Parent (Actual)) /= N_Parameter_Association
2327 or else Chars (Selector_Name (Parent (Actual))) = Chars (Formal)
2329 -- The actual can be compatible with the formal, but we must
2330 -- also check that the context is not an address type that is
2331 -- visibly an integer type, as is the case in VMS_64. In this
2332 -- case the use of literals is illegal, except in the body of
2333 -- descendents of system, where arithmetic operations on
2334 -- address are of course used.
2336 if Has_Compatible_Type (Actual, Etype (Formal))
2338 (Etype (Actual) /= Universal_Integer
2339 or else not Is_Descendent_Of_Address (Etype (Formal))
2341 Is_Predefined_File_Name
2342 (Unit_File_Name (Get_Source_Unit (N))))
2344 Next_Actual (Actual);
2345 Next_Formal (Formal);
2348 if Debug_Flag_E then
2349 Write_Str (" type checking fails in call ");
2350 Write_Int (Int (N));
2351 Write_Str (" with formal ");
2352 Write_Int (Int (Formal));
2353 Write_Str (" in subprogram ");
2354 Write_Int (Int (Nam));
2358 if Report and not Is_Indexed then
2360 -- Ada 2005 (AI-251): Complete the error notification
2361 -- to help new Ada 2005 users
2363 if Is_Class_Wide_Type (Etype (Formal))
2364 and then Is_Interface (Etype (Etype (Formal)))
2365 and then not Interface_Present_In_Ancestor
2366 (Typ => Etype (Actual),
2367 Iface => Etype (Etype (Formal)))
2370 ("(Ada 2005) does not implement interface }",
2371 Actual, Etype (Etype (Formal)));
2374 Wrong_Type (Actual, Etype (Formal));
2376 if Nkind (Actual) = N_Op_Eq
2377 and then Nkind (Left_Opnd (Actual)) = N_Identifier
2379 Formal := First_Formal (Nam);
2380 while Present (Formal) loop
2381 if Chars (Left_Opnd (Actual)) = Chars (Formal) then
2383 ("possible misspelling of `='>`!", Actual);
2387 Next_Formal (Formal);
2391 if All_Errors_Mode then
2392 Error_Msg_Sloc := Sloc (Nam);
2394 if Is_Overloadable (Nam)
2395 and then Present (Alias (Nam))
2396 and then not Comes_From_Source (Nam)
2399 ("\\ =='> in call to inherited operation & #!",
2402 elsif Ekind (Nam) = E_Subprogram_Type then
2404 Access_To_Subprogram_Typ :
2405 constant Entity_Id :=
2407 (Associated_Node_For_Itype (Nam));
2410 "\\ =='> in call to dereference of &#!",
2411 Actual, Access_To_Subprogram_Typ);
2416 ("\\ =='> in call to &#!", Actual, Nam);
2426 -- Normalize_Actuals has verified that a default value exists
2427 -- for this formal. Current actual names a subsequent formal.
2429 Next_Formal (Formal);
2433 -- On exit, all actuals match
2435 Indicate_Name_And_Type;
2437 end Analyze_One_Call;
2439 ---------------------------
2440 -- Analyze_Operator_Call --
2441 ---------------------------
2443 procedure Analyze_Operator_Call (N : Node_Id; Op_Id : Entity_Id) is
2444 Op_Name : constant Name_Id := Chars (Op_Id);
2445 Act1 : constant Node_Id := First_Actual (N);
2446 Act2 : constant Node_Id := Next_Actual (Act1);
2449 -- Binary operator case
2451 if Present (Act2) then
2453 -- If more than two operands, then not binary operator after all
2455 if Present (Next_Actual (Act2)) then
2458 elsif Op_Name = Name_Op_Add
2459 or else Op_Name = Name_Op_Subtract
2460 or else Op_Name = Name_Op_Multiply
2461 or else Op_Name = Name_Op_Divide
2462 or else Op_Name = Name_Op_Mod
2463 or else Op_Name = Name_Op_Rem
2464 or else Op_Name = Name_Op_Expon
2466 Find_Arithmetic_Types (Act1, Act2, Op_Id, N);
2468 elsif Op_Name = Name_Op_And
2469 or else Op_Name = Name_Op_Or
2470 or else Op_Name = Name_Op_Xor
2472 Find_Boolean_Types (Act1, Act2, Op_Id, N);
2474 elsif Op_Name = Name_Op_Lt
2475 or else Op_Name = Name_Op_Le
2476 or else Op_Name = Name_Op_Gt
2477 or else Op_Name = Name_Op_Ge
2479 Find_Comparison_Types (Act1, Act2, Op_Id, N);
2481 elsif Op_Name = Name_Op_Eq
2482 or else Op_Name = Name_Op_Ne
2484 Find_Equality_Types (Act1, Act2, Op_Id, N);
2486 elsif Op_Name = Name_Op_Concat then
2487 Find_Concatenation_Types (Act1, Act2, Op_Id, N);
2489 -- Is this else null correct, or should it be an abort???
2495 -- Unary operator case
2498 if Op_Name = Name_Op_Subtract or else
2499 Op_Name = Name_Op_Add or else
2500 Op_Name = Name_Op_Abs
2502 Find_Unary_Types (Act1, Op_Id, N);
2505 Op_Name = Name_Op_Not
2507 Find_Negation_Types (Act1, Op_Id, N);
2509 -- Is this else null correct, or should it be an abort???
2515 end Analyze_Operator_Call;
2517 -------------------------------------------
2518 -- Analyze_Overloaded_Selected_Component --
2519 -------------------------------------------
2521 procedure Analyze_Overloaded_Selected_Component (N : Node_Id) is
2522 Nam : constant Node_Id := Prefix (N);
2523 Sel : constant Node_Id := Selector_Name (N);
2530 Set_Etype (Sel, Any_Type);
2532 Get_First_Interp (Nam, I, It);
2533 while Present (It.Typ) loop
2534 if Is_Access_Type (It.Typ) then
2535 T := Designated_Type (It.Typ);
2536 Error_Msg_NW (Warn_On_Dereference, "?implicit dereference", N);
2541 if Is_Record_Type (T) then
2543 -- If the prefix is a class-wide type, the visible components are
2544 -- those of the base type.
2546 if Is_Class_Wide_Type (T) then
2550 Comp := First_Entity (T);
2551 while Present (Comp) loop
2552 if Chars (Comp) = Chars (Sel)
2553 and then Is_Visible_Component (Comp)
2555 Set_Entity (Sel, Comp);
2556 Set_Etype (Sel, Etype (Comp));
2557 Add_One_Interp (N, Etype (Comp), Etype (Comp));
2559 -- This also specifies a candidate to resolve the name.
2560 -- Further overloading will be resolved from context.
2562 Set_Etype (Nam, It.Typ);
2568 elsif Is_Concurrent_Type (T) then
2569 Comp := First_Entity (T);
2570 while Present (Comp)
2571 and then Comp /= First_Private_Entity (T)
2573 if Chars (Comp) = Chars (Sel) then
2574 if Is_Overloadable (Comp) then
2575 Add_One_Interp (Sel, Comp, Etype (Comp));
2577 Set_Entity_With_Style_Check (Sel, Comp);
2578 Generate_Reference (Comp, Sel);
2581 Set_Etype (Sel, Etype (Comp));
2582 Set_Etype (N, Etype (Comp));
2583 Set_Etype (Nam, It.Typ);
2585 -- For access type case, introduce explicit deference for
2586 -- more uniform treatment of entry calls. Do this only
2587 -- once if several interpretations yield an access type.
2589 if Is_Access_Type (Etype (Nam))
2590 and then Nkind (Nam) /= N_Explicit_Dereference
2592 Insert_Explicit_Dereference (Nam);
2594 (Warn_On_Dereference, "?implicit dereference", N);
2601 Set_Is_Overloaded (N, Is_Overloaded (Sel));
2604 Get_Next_Interp (I, It);
2607 if Etype (N) = Any_Type
2608 and then not Try_Object_Operation (N)
2610 Error_Msg_NE ("undefined selector& for overloaded prefix", N, Sel);
2611 Set_Entity (Sel, Any_Id);
2612 Set_Etype (Sel, Any_Type);
2614 end Analyze_Overloaded_Selected_Component;
2616 ----------------------------------
2617 -- Analyze_Qualified_Expression --
2618 ----------------------------------
2620 procedure Analyze_Qualified_Expression (N : Node_Id) is
2621 Mark : constant Entity_Id := Subtype_Mark (N);
2622 Expr : constant Node_Id := Expression (N);
2628 Analyze_Expression (Expr);
2630 Set_Etype (N, Any_Type);
2635 if T = Any_Type then
2639 Check_Fully_Declared (T, N);
2641 -- If expected type is class-wide, check for exact match before
2642 -- expansion, because if the expression is a dispatching call it
2643 -- may be rewritten as explicit dereference with class-wide result.
2644 -- If expression is overloaded, retain only interpretations that
2645 -- will yield exact matches.
2647 if Is_Class_Wide_Type (T) then
2648 if not Is_Overloaded (Expr) then
2649 if Base_Type (Etype (Expr)) /= Base_Type (T) then
2650 if Nkind (Expr) = N_Aggregate then
2651 Error_Msg_N ("type of aggregate cannot be class-wide", Expr);
2653 Wrong_Type (Expr, T);
2658 Get_First_Interp (Expr, I, It);
2660 while Present (It.Nam) loop
2661 if Base_Type (It.Typ) /= Base_Type (T) then
2665 Get_Next_Interp (I, It);
2671 end Analyze_Qualified_Expression;
2677 procedure Analyze_Range (N : Node_Id) is
2678 L : constant Node_Id := Low_Bound (N);
2679 H : constant Node_Id := High_Bound (N);
2680 I1, I2 : Interp_Index;
2683 procedure Check_Common_Type (T1, T2 : Entity_Id);
2684 -- Verify the compatibility of two types, and choose the
2685 -- non universal one if the other is universal.
2687 procedure Check_High_Bound (T : Entity_Id);
2688 -- Test one interpretation of the low bound against all those
2689 -- of the high bound.
2691 procedure Check_Universal_Expression (N : Node_Id);
2692 -- In Ada83, reject bounds of a universal range that are not
2693 -- literals or entity names.
2695 -----------------------
2696 -- Check_Common_Type --
2697 -----------------------
2699 procedure Check_Common_Type (T1, T2 : Entity_Id) is
2701 if Covers (T1 => T1, T2 => T2)
2703 Covers (T1 => T2, T2 => T1)
2705 if T1 = Universal_Integer
2706 or else T1 = Universal_Real
2707 or else T1 = Any_Character
2709 Add_One_Interp (N, Base_Type (T2), Base_Type (T2));
2712 Add_One_Interp (N, T1, T1);
2715 Add_One_Interp (N, Base_Type (T1), Base_Type (T1));
2718 end Check_Common_Type;
2720 ----------------------
2721 -- Check_High_Bound --
2722 ----------------------
2724 procedure Check_High_Bound (T : Entity_Id) is
2726 if not Is_Overloaded (H) then
2727 Check_Common_Type (T, Etype (H));
2729 Get_First_Interp (H, I2, It2);
2730 while Present (It2.Typ) loop
2731 Check_Common_Type (T, It2.Typ);
2732 Get_Next_Interp (I2, It2);
2735 end Check_High_Bound;
2737 -----------------------------
2738 -- Is_Universal_Expression --
2739 -----------------------------
2741 procedure Check_Universal_Expression (N : Node_Id) is
2743 if Etype (N) = Universal_Integer
2744 and then Nkind (N) /= N_Integer_Literal
2745 and then not Is_Entity_Name (N)
2746 and then Nkind (N) /= N_Attribute_Reference
2748 Error_Msg_N ("illegal bound in discrete range", N);
2750 end Check_Universal_Expression;
2752 -- Start of processing for Analyze_Range
2755 Set_Etype (N, Any_Type);
2756 Analyze_Expression (L);
2757 Analyze_Expression (H);
2759 if Etype (L) = Any_Type or else Etype (H) = Any_Type then
2763 if not Is_Overloaded (L) then
2764 Check_High_Bound (Etype (L));
2766 Get_First_Interp (L, I1, It1);
2767 while Present (It1.Typ) loop
2768 Check_High_Bound (It1.Typ);
2769 Get_Next_Interp (I1, It1);
2773 -- If result is Any_Type, then we did not find a compatible pair
2775 if Etype (N) = Any_Type then
2776 Error_Msg_N ("incompatible types in range ", N);
2780 if Ada_Version = Ada_83
2782 (Nkind (Parent (N)) = N_Loop_Parameter_Specification
2783 or else Nkind (Parent (N)) = N_Constrained_Array_Definition)
2785 Check_Universal_Expression (L);
2786 Check_Universal_Expression (H);
2790 -----------------------
2791 -- Analyze_Reference --
2792 -----------------------
2794 procedure Analyze_Reference (N : Node_Id) is
2795 P : constant Node_Id := Prefix (N);
2798 Acc_Type : Entity_Id;
2803 -- An interesting error check, if we take the 'Reference of an object
2804 -- for which a pragma Atomic or Volatile has been given, and the type
2805 -- of the object is not Atomic or Volatile, then we are in trouble. The
2806 -- problem is that no trace of the atomic/volatile status will remain
2807 -- for the backend to respect when it deals with the resulting pointer,
2808 -- since the pointer type will not be marked atomic (it is a pointer to
2809 -- the base type of the object).
2811 -- It is not clear if that can ever occur, but in case it does, we will
2812 -- generate an error message. Not clear if this message can ever be
2813 -- generated, and pretty clear that it represents a bug if it is, still
2814 -- seems worth checking!
2818 if Is_Entity_Name (P)
2819 and then Is_Object_Reference (P)
2824 if (Has_Atomic_Components (E)
2825 and then not Has_Atomic_Components (T))
2827 (Has_Volatile_Components (E)
2828 and then not Has_Volatile_Components (T))
2829 or else (Is_Atomic (E) and then not Is_Atomic (T))
2830 or else (Is_Volatile (E) and then not Is_Volatile (T))
2832 Error_Msg_N ("cannot take reference to Atomic/Volatile object", N);
2836 -- Carry on with normal processing
2838 Acc_Type := Create_Itype (E_Allocator_Type, N);
2839 Set_Etype (Acc_Type, Acc_Type);
2840 Set_Directly_Designated_Type (Acc_Type, Etype (P));
2841 Set_Etype (N, Acc_Type);
2842 end Analyze_Reference;
2844 --------------------------------
2845 -- Analyze_Selected_Component --
2846 --------------------------------
2848 -- Prefix is a record type or a task or protected type. In the
2849 -- later case, the selector must denote a visible entry.
2851 procedure Analyze_Selected_Component (N : Node_Id) is
2852 Name : constant Node_Id := Prefix (N);
2853 Sel : constant Node_Id := Selector_Name (N);
2856 Has_Candidate : Boolean := False;
2859 Pent : Entity_Id := Empty;
2860 Prefix_Type : Entity_Id;
2862 Type_To_Use : Entity_Id;
2863 -- In most cases this is the Prefix_Type, but if the Prefix_Type is
2864 -- a class-wide type, we use its root type, whose components are
2865 -- present in the class-wide type.
2867 function Has_Mode_Conformant_Spec (Comp : Entity_Id) return Boolean;
2868 -- It is known that the parent of N denotes a subprogram call. Comp
2869 -- is an overloadable component of the concurrent type of the prefix.
2870 -- Determine whether all formals of the parent of N and Comp are mode
2871 -- conformant. If the parent node is not analyzed yet it may be an
2872 -- indexed component rather than a function call.
2874 ------------------------------
2875 -- Has_Mode_Conformant_Spec --
2876 ------------------------------
2878 function Has_Mode_Conformant_Spec (Comp : Entity_Id) return Boolean is
2879 Comp_Param : Entity_Id;
2881 Param_Typ : Entity_Id;
2884 Comp_Param := First_Formal (Comp);
2886 if Nkind (Parent (N)) = N_Indexed_Component then
2887 Param := First (Expressions (Parent (N)));
2889 Param := First (Parameter_Associations (Parent (N)));
2892 while Present (Comp_Param)
2893 and then Present (Param)
2895 Param_Typ := Find_Parameter_Type (Param);
2897 if Present (Param_Typ)
2899 not Conforming_Types
2900 (Etype (Comp_Param), Param_Typ, Mode_Conformant)
2905 Next_Formal (Comp_Param);
2909 -- One of the specs has additional formals
2911 if Present (Comp_Param) or else Present (Param) then
2916 end Has_Mode_Conformant_Spec;
2918 -- Start of processing for Analyze_Selected_Component
2921 Set_Etype (N, Any_Type);
2923 if Is_Overloaded (Name) then
2924 Analyze_Overloaded_Selected_Component (N);
2927 elsif Etype (Name) = Any_Type then
2928 Set_Entity (Sel, Any_Id);
2929 Set_Etype (Sel, Any_Type);
2933 Prefix_Type := Etype (Name);
2936 if Is_Access_Type (Prefix_Type) then
2938 -- A RACW object can never be used as prefix of a selected
2939 -- component since that means it is dereferenced without
2940 -- being a controlling operand of a dispatching operation
2941 -- (RM E.2.2(16/1)). Before reporting an error, we must check
2942 -- whether this is actually a dispatching call in prefix form.
2944 if Is_Remote_Access_To_Class_Wide_Type (Prefix_Type)
2945 and then Comes_From_Source (N)
2947 if Try_Object_Operation (N) then
2951 ("invalid dereference of a remote access-to-class-wide value",
2955 -- Normal case of selected component applied to access type
2958 Error_Msg_NW (Warn_On_Dereference, "?implicit dereference", N);
2960 if Is_Entity_Name (Name) then
2961 Pent := Entity (Name);
2962 elsif Nkind (Name) = N_Selected_Component
2963 and then Is_Entity_Name (Selector_Name (Name))
2965 Pent := Entity (Selector_Name (Name));
2968 Prefix_Type := Process_Implicit_Dereference_Prefix (Pent, Name);
2971 -- If we have an explicit dereference of a remote access-to-class-wide
2972 -- value, then issue an error (see RM-E.2.2(16/1)). However we first
2973 -- have to check for the case of a prefix that is a controlling operand
2974 -- of a prefixed dispatching call, as the dereference is legal in that
2975 -- case. Normally this condition is checked in Validate_Remote_Access_
2976 -- To_Class_Wide_Type, but we have to defer the checking for selected
2977 -- component prefixes because of the prefixed dispatching call case.
2978 -- Note that implicit dereferences are checked for this just above.
2980 elsif Nkind (Name) = N_Explicit_Dereference
2981 and then Is_Remote_Access_To_Class_Wide_Type (Etype (Prefix (Name)))
2982 and then Comes_From_Source (N)
2984 if Try_Object_Operation (N) then
2988 ("invalid dereference of a remote access-to-class-wide value",
2993 -- (Ada 2005): if the prefix is the limited view of a type, and
2994 -- the context already includes the full view, use the full view
2995 -- in what follows, either to retrieve a component of to find
2996 -- a primitive operation. If the prefix is an explicit dereference,
2997 -- set the type of the prefix to reflect this transformation.
2998 -- If the non-limited view is itself an incomplete type, get the
2999 -- full view if available.
3001 if Is_Incomplete_Type (Prefix_Type)
3002 and then From_With_Type (Prefix_Type)
3003 and then Present (Non_Limited_View (Prefix_Type))
3005 Prefix_Type := Get_Full_View (Non_Limited_View (Prefix_Type));
3007 if Nkind (N) = N_Explicit_Dereference then
3008 Set_Etype (Prefix (N), Prefix_Type);
3011 elsif Ekind (Prefix_Type) = E_Class_Wide_Type
3012 and then From_With_Type (Prefix_Type)
3013 and then Present (Non_Limited_View (Etype (Prefix_Type)))
3016 Class_Wide_Type (Non_Limited_View (Etype (Prefix_Type)));
3018 if Nkind (N) = N_Explicit_Dereference then
3019 Set_Etype (Prefix (N), Prefix_Type);
3023 if Ekind (Prefix_Type) = E_Private_Subtype then
3024 Prefix_Type := Base_Type (Prefix_Type);
3027 Type_To_Use := Prefix_Type;
3029 -- For class-wide types, use the entity list of the root type. This
3030 -- indirection is specially important for private extensions because
3031 -- only the root type get switched (not the class-wide type).
3033 if Is_Class_Wide_Type (Prefix_Type) then
3034 Type_To_Use := Root_Type (Prefix_Type);
3037 Comp := First_Entity (Type_To_Use);
3039 -- If the selector has an original discriminant, the node appears in
3040 -- an instance. Replace the discriminant with the corresponding one
3041 -- in the current discriminated type. For nested generics, this must
3042 -- be done transitively, so note the new original discriminant.
3044 if Nkind (Sel) = N_Identifier
3045 and then Present (Original_Discriminant (Sel))
3047 Comp := Find_Corresponding_Discriminant (Sel, Prefix_Type);
3049 -- Mark entity before rewriting, for completeness and because
3050 -- subsequent semantic checks might examine the original node.
3052 Set_Entity (Sel, Comp);
3053 Rewrite (Selector_Name (N),
3054 New_Occurrence_Of (Comp, Sloc (N)));
3055 Set_Original_Discriminant (Selector_Name (N), Comp);
3056 Set_Etype (N, Etype (Comp));
3058 if Is_Access_Type (Etype (Name)) then
3059 Insert_Explicit_Dereference (Name);
3060 Error_Msg_NW (Warn_On_Dereference, "?implicit dereference", N);
3063 elsif Is_Record_Type (Prefix_Type) then
3065 -- Find component with given name
3067 while Present (Comp) loop
3068 if Chars (Comp) = Chars (Sel)
3069 and then Is_Visible_Component (Comp)
3071 Set_Entity_With_Style_Check (Sel, Comp);
3072 Set_Etype (Sel, Etype (Comp));
3074 if Ekind (Comp) = E_Discriminant then
3075 if Is_Unchecked_Union (Base_Type (Prefix_Type)) then
3077 ("cannot reference discriminant of Unchecked_Union",
3081 if Is_Generic_Type (Prefix_Type)
3083 Is_Generic_Type (Root_Type (Prefix_Type))
3085 Set_Original_Discriminant (Sel, Comp);
3089 -- Resolve the prefix early otherwise it is not possible to
3090 -- build the actual subtype of the component: it may need
3091 -- to duplicate this prefix and duplication is only allowed
3092 -- on fully resolved expressions.
3096 -- Ada 2005 (AI-50217): Check wrong use of incomplete types or
3097 -- subtypes in a package specification.
3100 -- limited with Pkg;
3102 -- type Acc_Inc is access Pkg.T;
3104 -- N : Natural := X.all.Comp; -- ERROR, limited view
3105 -- end Pkg; -- Comp is not visible
3107 if Nkind (Name) = N_Explicit_Dereference
3108 and then From_With_Type (Etype (Prefix (Name)))
3109 and then not Is_Potentially_Use_Visible (Etype (Name))
3110 and then Nkind (Parent (Cunit_Entity (Current_Sem_Unit))) =
3111 N_Package_Specification
3114 ("premature usage of incomplete}", Prefix (Name),
3115 Etype (Prefix (Name)));
3118 -- We never need an actual subtype for the case of a selection
3119 -- for a indexed component of a non-packed array, since in
3120 -- this case gigi generates all the checks and can find the
3121 -- necessary bounds information.
3123 -- We also do not need an actual subtype for the case of
3124 -- a first, last, length, or range attribute applied to a
3125 -- non-packed array, since gigi can again get the bounds in
3126 -- these cases (gigi cannot handle the packed case, since it
3127 -- has the bounds of the packed array type, not the original
3128 -- bounds of the type). However, if the prefix is itself a
3129 -- selected component, as in a.b.c (i), gigi may regard a.b.c
3130 -- as a dynamic-sized temporary, so we do generate an actual
3131 -- subtype for this case.
3133 Parent_N := Parent (N);
3135 if not Is_Packed (Etype (Comp))
3137 ((Nkind (Parent_N) = N_Indexed_Component
3138 and then Nkind (Name) /= N_Selected_Component)
3140 (Nkind (Parent_N) = N_Attribute_Reference
3141 and then (Attribute_Name (Parent_N) = Name_First
3143 Attribute_Name (Parent_N) = Name_Last
3145 Attribute_Name (Parent_N) = Name_Length
3147 Attribute_Name (Parent_N) = Name_Range)))
3149 Set_Etype (N, Etype (Comp));
3151 -- If full analysis is not enabled, we do not generate an
3152 -- actual subtype, because in the absence of expansion
3153 -- reference to a formal of a protected type, for example,
3154 -- will not be properly transformed, and will lead to
3155 -- out-of-scope references in gigi.
3157 -- In all other cases, we currently build an actual subtype.
3158 -- It seems likely that many of these cases can be avoided,
3159 -- but right now, the front end makes direct references to the
3160 -- bounds (e.g. in generating a length check), and if we do
3161 -- not make an actual subtype, we end up getting a direct
3162 -- reference to a discriminant, which will not do.
3164 elsif Full_Analysis then
3166 Build_Actual_Subtype_Of_Component (Etype (Comp), N);
3167 Insert_Action (N, Act_Decl);
3169 if No (Act_Decl) then
3170 Set_Etype (N, Etype (Comp));
3173 -- Component type depends on discriminants. Enter the
3174 -- main attributes of the subtype.
3177 Subt : constant Entity_Id :=
3178 Defining_Identifier (Act_Decl);
3181 Set_Etype (Subt, Base_Type (Etype (Comp)));
3182 Set_Ekind (Subt, Ekind (Etype (Comp)));
3183 Set_Etype (N, Subt);
3187 -- If Full_Analysis not enabled, just set the Etype
3190 Set_Etype (N, Etype (Comp));
3196 -- If the prefix is a private extension, check only the visible
3197 -- components of the partial view. This must include the tag,
3198 -- wich can appear in expanded code in a tag check.
3200 if Ekind (Type_To_Use) = E_Record_Type_With_Private
3201 and then Chars (Selector_Name (N)) /= Name_uTag
3203 exit when Comp = Last_Entity (Type_To_Use);
3209 -- Ada 2005 (AI-252): The selected component can be interpreted as
3210 -- a prefixed view of a subprogram. Depending on the context, this is
3211 -- either a name that can appear in a renaming declaration, or part
3212 -- of an enclosing call given in prefix form.
3214 -- Ada 2005 (AI05-0030): In the case of dispatching requeue, the
3215 -- selected component should resolve to a name.
3217 if Ada_Version >= Ada_05
3218 and then Is_Tagged_Type (Prefix_Type)
3219 and then not Is_Concurrent_Type (Prefix_Type)
3221 if Nkind (Parent (N)) = N_Generic_Association
3222 or else Nkind (Parent (N)) = N_Requeue_Statement
3223 or else Nkind (Parent (N)) = N_Subprogram_Renaming_Declaration
3225 if Find_Primitive_Operation (N) then
3229 elsif Try_Object_Operation (N) then
3233 -- If the transformation fails, it will be necessary to redo the
3234 -- analysis with all errors enabled, to indicate candidate
3235 -- interpretations and reasons for each failure ???
3239 elsif Is_Private_Type (Prefix_Type) then
3241 -- Allow access only to discriminants of the type. If the type has
3242 -- no full view, gigi uses the parent type for the components, so we
3243 -- do the same here.
3245 if No (Full_View (Prefix_Type)) then
3246 Type_To_Use := Root_Type (Base_Type (Prefix_Type));
3247 Comp := First_Entity (Type_To_Use);
3250 while Present (Comp) loop
3251 if Chars (Comp) = Chars (Sel) then
3252 if Ekind (Comp) = E_Discriminant then
3253 Set_Entity_With_Style_Check (Sel, Comp);
3254 Generate_Reference (Comp, Sel);
3256 Set_Etype (Sel, Etype (Comp));
3257 Set_Etype (N, Etype (Comp));
3259 if Is_Generic_Type (Prefix_Type)
3260 or else Is_Generic_Type (Root_Type (Prefix_Type))
3262 Set_Original_Discriminant (Sel, Comp);
3265 -- Before declararing an error, check whether this is tagged
3266 -- private type and a call to a primitive operation.
3268 elsif Ada_Version >= Ada_05
3269 and then Is_Tagged_Type (Prefix_Type)
3270 and then Try_Object_Operation (N)
3276 ("invisible selector for }",
3277 N, First_Subtype (Prefix_Type));
3278 Set_Entity (Sel, Any_Id);
3279 Set_Etype (N, Any_Type);
3288 elsif Is_Concurrent_Type (Prefix_Type) then
3290 -- Find visible operation with given name. For a protected type,
3291 -- the possible candidates are discriminants, entries or protected
3292 -- procedures. For a task type, the set can only include entries or
3293 -- discriminants if the task type is not an enclosing scope. If it
3294 -- is an enclosing scope (e.g. in an inner task) then all entities
3295 -- are visible, but the prefix must denote the enclosing scope, i.e.
3296 -- can only be a direct name or an expanded name.
3298 Set_Etype (Sel, Any_Type);
3299 In_Scope := In_Open_Scopes (Prefix_Type);
3301 while Present (Comp) loop
3302 if Chars (Comp) = Chars (Sel) then
3303 if Is_Overloadable (Comp) then
3304 Add_One_Interp (Sel, Comp, Etype (Comp));
3306 -- If the prefix is tagged, the correct interpretation may
3307 -- lie in the primitive or class-wide operations of the
3308 -- type. Perform a simple conformance check to determine
3309 -- whether Try_Object_Operation should be invoked even if
3310 -- a visible entity is found.
3312 if Is_Tagged_Type (Prefix_Type)
3314 Nkind_In (Parent (N), N_Procedure_Call_Statement,
3316 N_Indexed_Component)
3317 and then Has_Mode_Conformant_Spec (Comp)
3319 Has_Candidate := True;
3322 elsif Ekind (Comp) = E_Discriminant
3323 or else Ekind (Comp) = E_Entry_Family
3325 and then Is_Entity_Name (Name))
3327 Set_Entity_With_Style_Check (Sel, Comp);
3328 Generate_Reference (Comp, Sel);
3334 Set_Etype (Sel, Etype (Comp));
3335 Set_Etype (N, Etype (Comp));
3337 if Ekind (Comp) = E_Discriminant then
3338 Set_Original_Discriminant (Sel, Comp);
3341 -- For access type case, introduce explicit deference for more
3342 -- uniform treatment of entry calls.
3344 if Is_Access_Type (Etype (Name)) then
3345 Insert_Explicit_Dereference (Name);
3347 (Warn_On_Dereference, "?implicit dereference", N);
3353 exit when not In_Scope
3355 Comp = First_Private_Entity (Base_Type (Prefix_Type));
3358 -- If there is no visible entity with the given name or none of the
3359 -- visible entities are plausible interpretations, check whether
3360 -- there is some other primitive operation with that name.
3362 if Ada_Version >= Ada_05
3363 and then Is_Tagged_Type (Prefix_Type)
3365 if (Etype (N) = Any_Type
3366 or else not Has_Candidate)
3367 and then Try_Object_Operation (N)
3371 -- If the context is not syntactically a procedure call, it
3372 -- may be a call to a primitive function declared outside of
3373 -- the synchronized type.
3375 -- If the context is a procedure call, there might still be
3376 -- an overloading between an entry and a primitive procedure
3377 -- declared outside of the synchronized type, called in prefix
3378 -- notation. This is harder to disambiguate because in one case
3379 -- the controlling formal is implicit ???
3381 elsif Nkind (Parent (N)) /= N_Procedure_Call_Statement
3382 and then Nkind (Parent (N)) /= N_Indexed_Component
3383 and then Try_Object_Operation (N)
3389 Set_Is_Overloaded (N, Is_Overloaded (Sel));
3394 Error_Msg_NE ("invalid prefix in selected component&", N, Sel);
3397 -- If N still has no type, the component is not defined in the prefix
3399 if Etype (N) = Any_Type then
3401 -- If the prefix is a single concurrent object, use its name in the
3402 -- error message, rather than that of its anonymous type.
3404 if Is_Concurrent_Type (Prefix_Type)
3405 and then Is_Internal_Name (Chars (Prefix_Type))
3406 and then not Is_Derived_Type (Prefix_Type)
3407 and then Is_Entity_Name (Name)
3410 Error_Msg_Node_2 := Entity (Name);
3411 Error_Msg_NE ("no selector& for&", N, Sel);
3413 Check_Misspelled_Selector (Type_To_Use, Sel);
3415 elsif Is_Generic_Type (Prefix_Type)
3416 and then Ekind (Prefix_Type) = E_Record_Type_With_Private
3417 and then Prefix_Type /= Etype (Prefix_Type)
3418 and then Is_Record_Type (Etype (Prefix_Type))
3420 -- If this is a derived formal type, the parent may have
3421 -- different visibility at this point. Try for an inherited
3422 -- component before reporting an error.
3424 Set_Etype (Prefix (N), Etype (Prefix_Type));
3425 Analyze_Selected_Component (N);
3428 elsif Ekind (Prefix_Type) = E_Record_Subtype_With_Private
3429 and then Is_Generic_Actual_Type (Prefix_Type)
3430 and then Present (Full_View (Prefix_Type))
3432 -- Similarly, if this the actual for a formal derived type, the
3433 -- component inherited from the generic parent may not be visible
3434 -- in the actual, but the selected component is legal.
3441 First_Component (Generic_Parent_Type (Parent (Prefix_Type)));
3442 while Present (Comp) loop
3443 if Chars (Comp) = Chars (Sel) then
3444 Set_Entity_With_Style_Check (Sel, Comp);
3445 Set_Etype (Sel, Etype (Comp));
3446 Set_Etype (N, Etype (Comp));
3450 Next_Component (Comp);
3453 pragma Assert (Etype (N) /= Any_Type);
3457 if Ekind (Prefix_Type) = E_Record_Subtype then
3459 -- Check whether this is a component of the base type
3460 -- which is absent from a statically constrained subtype.
3461 -- This will raise constraint error at run-time, but is
3462 -- not a compile-time error. When the selector is illegal
3463 -- for base type as well fall through and generate a
3464 -- compilation error anyway.
3466 Comp := First_Component (Base_Type (Prefix_Type));
3467 while Present (Comp) loop
3468 if Chars (Comp) = Chars (Sel)
3469 and then Is_Visible_Component (Comp)
3471 Set_Entity_With_Style_Check (Sel, Comp);
3472 Generate_Reference (Comp, Sel);
3473 Set_Etype (Sel, Etype (Comp));
3474 Set_Etype (N, Etype (Comp));
3476 -- Emit appropriate message. Gigi will replace the
3477 -- node subsequently with the appropriate Raise.
3479 Apply_Compile_Time_Constraint_Error
3480 (N, "component not present in }?",
3481 CE_Discriminant_Check_Failed,
3482 Ent => Prefix_Type, Rep => False);
3483 Set_Raises_Constraint_Error (N);
3487 Next_Component (Comp);
3492 Error_Msg_Node_2 := First_Subtype (Prefix_Type);
3493 Error_Msg_NE ("no selector& for}", N, Sel);
3495 Check_Misspelled_Selector (Type_To_Use, Sel);
3499 Set_Entity (Sel, Any_Id);
3500 Set_Etype (Sel, Any_Type);
3502 end Analyze_Selected_Component;
3504 ---------------------------
3505 -- Analyze_Short_Circuit --
3506 ---------------------------
3508 procedure Analyze_Short_Circuit (N : Node_Id) is
3509 L : constant Node_Id := Left_Opnd (N);
3510 R : constant Node_Id := Right_Opnd (N);
3515 Analyze_Expression (L);
3516 Analyze_Expression (R);
3517 Set_Etype (N, Any_Type);
3519 if not Is_Overloaded (L) then
3520 if Root_Type (Etype (L)) = Standard_Boolean
3521 and then Has_Compatible_Type (R, Etype (L))
3523 Add_One_Interp (N, Etype (L), Etype (L));
3527 Get_First_Interp (L, Ind, It);
3528 while Present (It.Typ) loop
3529 if Root_Type (It.Typ) = Standard_Boolean
3530 and then Has_Compatible_Type (R, It.Typ)
3532 Add_One_Interp (N, It.Typ, It.Typ);
3535 Get_Next_Interp (Ind, It);
3539 -- Here we have failed to find an interpretation. Clearly we know that
3540 -- it is not the case that both operands can have an interpretation of
3541 -- Boolean, but this is by far the most likely intended interpretation.
3542 -- So we simply resolve both operands as Booleans, and at least one of
3543 -- these resolutions will generate an error message, and we do not need
3544 -- to give another error message on the short circuit operation itself.
3546 if Etype (N) = Any_Type then
3547 Resolve (L, Standard_Boolean);
3548 Resolve (R, Standard_Boolean);
3549 Set_Etype (N, Standard_Boolean);
3551 end Analyze_Short_Circuit;
3557 procedure Analyze_Slice (N : Node_Id) is
3558 P : constant Node_Id := Prefix (N);
3559 D : constant Node_Id := Discrete_Range (N);
3560 Array_Type : Entity_Id;
3562 procedure Analyze_Overloaded_Slice;
3563 -- If the prefix is overloaded, select those interpretations that
3564 -- yield a one-dimensional array type.
3566 ------------------------------
3567 -- Analyze_Overloaded_Slice --
3568 ------------------------------
3570 procedure Analyze_Overloaded_Slice is
3576 Set_Etype (N, Any_Type);
3578 Get_First_Interp (P, I, It);
3579 while Present (It.Nam) loop
3582 if Is_Access_Type (Typ) then
3583 Typ := Designated_Type (Typ);
3584 Error_Msg_NW (Warn_On_Dereference, "?implicit dereference", N);
3587 if Is_Array_Type (Typ)
3588 and then Number_Dimensions (Typ) = 1
3589 and then Has_Compatible_Type (D, Etype (First_Index (Typ)))
3591 Add_One_Interp (N, Typ, Typ);
3594 Get_Next_Interp (I, It);
3597 if Etype (N) = Any_Type then
3598 Error_Msg_N ("expect array type in prefix of slice", N);
3600 end Analyze_Overloaded_Slice;
3602 -- Start of processing for Analyze_Slice
3608 if Is_Overloaded (P) then
3609 Analyze_Overloaded_Slice;
3612 Array_Type := Etype (P);
3613 Set_Etype (N, Any_Type);
3615 if Is_Access_Type (Array_Type) then
3616 Array_Type := Designated_Type (Array_Type);
3617 Error_Msg_NW (Warn_On_Dereference, "?implicit dereference", N);
3620 if not Is_Array_Type (Array_Type) then
3621 Wrong_Type (P, Any_Array);
3623 elsif Number_Dimensions (Array_Type) > 1 then
3625 ("type is not one-dimensional array in slice prefix", N);
3628 Has_Compatible_Type (D, Etype (First_Index (Array_Type)))
3630 Wrong_Type (D, Etype (First_Index (Array_Type)));
3633 Set_Etype (N, Array_Type);
3638 -----------------------------
3639 -- Analyze_Type_Conversion --
3640 -----------------------------
3642 procedure Analyze_Type_Conversion (N : Node_Id) is
3643 Expr : constant Node_Id := Expression (N);
3647 -- If Conversion_OK is set, then the Etype is already set, and the
3648 -- only processing required is to analyze the expression. This is
3649 -- used to construct certain "illegal" conversions which are not
3650 -- allowed by Ada semantics, but can be handled OK by Gigi, see
3651 -- Sinfo for further details.
3653 if Conversion_OK (N) then
3658 -- Otherwise full type analysis is required, as well as some semantic
3659 -- checks to make sure the argument of the conversion is appropriate.
3661 Find_Type (Subtype_Mark (N));
3662 T := Entity (Subtype_Mark (N));
3664 Check_Fully_Declared (T, N);
3665 Analyze_Expression (Expr);
3666 Validate_Remote_Type_Type_Conversion (N);
3668 -- Only remaining step is validity checks on the argument. These
3669 -- are skipped if the conversion does not come from the source.
3671 if not Comes_From_Source (N) then
3674 -- If there was an error in a generic unit, no need to replicate the
3675 -- error message. Conversely, constant-folding in the generic may
3676 -- transform the argument of a conversion into a string literal, which
3677 -- is legal. Therefore the following tests are not performed in an
3680 elsif In_Instance then
3683 elsif Nkind (Expr) = N_Null then
3684 Error_Msg_N ("argument of conversion cannot be null", N);
3685 Error_Msg_N ("\use qualified expression instead", N);
3686 Set_Etype (N, Any_Type);
3688 elsif Nkind (Expr) = N_Aggregate then
3689 Error_Msg_N ("argument of conversion cannot be aggregate", N);
3690 Error_Msg_N ("\use qualified expression instead", N);
3692 elsif Nkind (Expr) = N_Allocator then
3693 Error_Msg_N ("argument of conversion cannot be an allocator", N);
3694 Error_Msg_N ("\use qualified expression instead", N);
3696 elsif Nkind (Expr) = N_String_Literal then
3697 Error_Msg_N ("argument of conversion cannot be string literal", N);
3698 Error_Msg_N ("\use qualified expression instead", N);
3700 elsif Nkind (Expr) = N_Character_Literal then
3701 if Ada_Version = Ada_83 then
3704 Error_Msg_N ("argument of conversion cannot be character literal",
3706 Error_Msg_N ("\use qualified expression instead", N);
3709 elsif Nkind (Expr) = N_Attribute_Reference
3711 (Attribute_Name (Expr) = Name_Access or else
3712 Attribute_Name (Expr) = Name_Unchecked_Access or else
3713 Attribute_Name (Expr) = Name_Unrestricted_Access)
3715 Error_Msg_N ("argument of conversion cannot be access", N);
3716 Error_Msg_N ("\use qualified expression instead", N);
3718 end Analyze_Type_Conversion;
3720 ----------------------
3721 -- Analyze_Unary_Op --
3722 ----------------------
3724 procedure Analyze_Unary_Op (N : Node_Id) is
3725 R : constant Node_Id := Right_Opnd (N);
3726 Op_Id : Entity_Id := Entity (N);
3729 Set_Etype (N, Any_Type);
3730 Candidate_Type := Empty;
3732 Analyze_Expression (R);
3734 if Present (Op_Id) then
3735 if Ekind (Op_Id) = E_Operator then
3736 Find_Unary_Types (R, Op_Id, N);
3738 Add_One_Interp (N, Op_Id, Etype (Op_Id));
3742 Op_Id := Get_Name_Entity_Id (Chars (N));
3743 while Present (Op_Id) loop
3744 if Ekind (Op_Id) = E_Operator then
3745 if No (Next_Entity (First_Entity (Op_Id))) then
3746 Find_Unary_Types (R, Op_Id, N);
3749 elsif Is_Overloadable (Op_Id) then
3750 Analyze_User_Defined_Unary_Op (N, Op_Id);
3753 Op_Id := Homonym (Op_Id);
3758 end Analyze_Unary_Op;
3760 ----------------------------------
3761 -- Analyze_Unchecked_Expression --
3762 ----------------------------------
3764 procedure Analyze_Unchecked_Expression (N : Node_Id) is
3766 Analyze (Expression (N), Suppress => All_Checks);
3767 Set_Etype (N, Etype (Expression (N)));
3768 Save_Interps (Expression (N), N);
3769 end Analyze_Unchecked_Expression;
3771 ---------------------------------------
3772 -- Analyze_Unchecked_Type_Conversion --
3773 ---------------------------------------
3775 procedure Analyze_Unchecked_Type_Conversion (N : Node_Id) is
3777 Find_Type (Subtype_Mark (N));
3778 Analyze_Expression (Expression (N));
3779 Set_Etype (N, Entity (Subtype_Mark (N)));
3780 end Analyze_Unchecked_Type_Conversion;
3782 ------------------------------------
3783 -- Analyze_User_Defined_Binary_Op --
3784 ------------------------------------
3786 procedure Analyze_User_Defined_Binary_Op
3791 -- Only do analysis if the operator Comes_From_Source, since otherwise
3792 -- the operator was generated by the expander, and all such operators
3793 -- always refer to the operators in package Standard.
3795 if Comes_From_Source (N) then
3797 F1 : constant Entity_Id := First_Formal (Op_Id);
3798 F2 : constant Entity_Id := Next_Formal (F1);
3801 -- Verify that Op_Id is a visible binary function. Note that since
3802 -- we know Op_Id is overloaded, potentially use visible means use
3803 -- visible for sure (RM 9.4(11)).
3805 if Ekind (Op_Id) = E_Function
3806 and then Present (F2)
3807 and then (Is_Immediately_Visible (Op_Id)
3808 or else Is_Potentially_Use_Visible (Op_Id))
3809 and then Has_Compatible_Type (Left_Opnd (N), Etype (F1))
3810 and then Has_Compatible_Type (Right_Opnd (N), Etype (F2))
3812 Add_One_Interp (N, Op_Id, Etype (Op_Id));
3814 if Debug_Flag_E then
3815 Write_Str ("user defined operator ");
3816 Write_Name (Chars (Op_Id));
3817 Write_Str (" on node ");
3818 Write_Int (Int (N));
3824 end Analyze_User_Defined_Binary_Op;
3826 -----------------------------------
3827 -- Analyze_User_Defined_Unary_Op --
3828 -----------------------------------
3830 procedure Analyze_User_Defined_Unary_Op
3835 -- Only do analysis if the operator Comes_From_Source, since otherwise
3836 -- the operator was generated by the expander, and all such operators
3837 -- always refer to the operators in package Standard.
3839 if Comes_From_Source (N) then
3841 F : constant Entity_Id := First_Formal (Op_Id);
3844 -- Verify that Op_Id is a visible unary function. Note that since
3845 -- we know Op_Id is overloaded, potentially use visible means use
3846 -- visible for sure (RM 9.4(11)).
3848 if Ekind (Op_Id) = E_Function
3849 and then No (Next_Formal (F))
3850 and then (Is_Immediately_Visible (Op_Id)
3851 or else Is_Potentially_Use_Visible (Op_Id))
3852 and then Has_Compatible_Type (Right_Opnd (N), Etype (F))
3854 Add_One_Interp (N, Op_Id, Etype (Op_Id));
3858 end Analyze_User_Defined_Unary_Op;
3860 ---------------------------
3861 -- Check_Arithmetic_Pair --
3862 ---------------------------
3864 procedure Check_Arithmetic_Pair
3865 (T1, T2 : Entity_Id;
3869 Op_Name : constant Name_Id := Chars (Op_Id);
3871 function Has_Fixed_Op (Typ : Entity_Id; Op : Entity_Id) return Boolean;
3872 -- Check whether the fixed-point type Typ has a user-defined operator
3873 -- (multiplication or division) that should hide the corresponding
3874 -- predefined operator. Used to implement Ada 2005 AI-264, to make
3875 -- such operators more visible and therefore useful.
3877 -- If the name of the operation is an expanded name with prefix
3878 -- Standard, the predefined universal fixed operator is available,
3879 -- as specified by AI-420 (RM 4.5.5 (19.1/2)).
3881 function Specific_Type (T1, T2 : Entity_Id) return Entity_Id;
3882 -- Get specific type (i.e. non-universal type if there is one)
3888 function Has_Fixed_Op (Typ : Entity_Id; Op : Entity_Id) return Boolean is
3889 Bas : constant Entity_Id := Base_Type (Typ);
3895 -- If the universal_fixed operation is given explicitly the rule
3896 -- concerning primitive operations of the type do not apply.
3898 if Nkind (N) = N_Function_Call
3899 and then Nkind (Name (N)) = N_Expanded_Name
3900 and then Entity (Prefix (Name (N))) = Standard_Standard
3905 -- The operation is treated as primitive if it is declared in the
3906 -- same scope as the type, and therefore on the same entity chain.
3908 Ent := Next_Entity (Typ);
3909 while Present (Ent) loop
3910 if Chars (Ent) = Chars (Op) then
3911 F1 := First_Formal (Ent);
3912 F2 := Next_Formal (F1);
3914 -- The operation counts as primitive if either operand or
3915 -- result are of the given base type, and both operands are
3916 -- fixed point types.
3918 if (Base_Type (Etype (F1)) = Bas
3919 and then Is_Fixed_Point_Type (Etype (F2)))
3922 (Base_Type (Etype (F2)) = Bas
3923 and then Is_Fixed_Point_Type (Etype (F1)))
3926 (Base_Type (Etype (Ent)) = Bas
3927 and then Is_Fixed_Point_Type (Etype (F1))
3928 and then Is_Fixed_Point_Type (Etype (F2)))
3944 function Specific_Type (T1, T2 : Entity_Id) return Entity_Id is
3946 if T1 = Universal_Integer or else T1 = Universal_Real then
3947 return Base_Type (T2);
3949 return Base_Type (T1);
3953 -- Start of processing for Check_Arithmetic_Pair
3956 if Op_Name = Name_Op_Add or else Op_Name = Name_Op_Subtract then
3958 if Is_Numeric_Type (T1)
3959 and then Is_Numeric_Type (T2)
3960 and then (Covers (T1 => T1, T2 => T2)
3962 Covers (T1 => T2, T2 => T1))
3964 Add_One_Interp (N, Op_Id, Specific_Type (T1, T2));
3967 elsif Op_Name = Name_Op_Multiply or else Op_Name = Name_Op_Divide then
3969 if Is_Fixed_Point_Type (T1)
3970 and then (Is_Fixed_Point_Type (T2)
3971 or else T2 = Universal_Real)
3973 -- If Treat_Fixed_As_Integer is set then the Etype is already set
3974 -- and no further processing is required (this is the case of an
3975 -- operator constructed by Exp_Fixd for a fixed point operation)
3976 -- Otherwise add one interpretation with universal fixed result
3977 -- If the operator is given in functional notation, it comes
3978 -- from source and Fixed_As_Integer cannot apply.
3980 if (Nkind (N) not in N_Op
3981 or else not Treat_Fixed_As_Integer (N))
3983 (not Has_Fixed_Op (T1, Op_Id)
3984 or else Nkind (Parent (N)) = N_Type_Conversion)
3986 Add_One_Interp (N, Op_Id, Universal_Fixed);
3989 elsif Is_Fixed_Point_Type (T2)
3990 and then (Nkind (N) not in N_Op
3991 or else not Treat_Fixed_As_Integer (N))
3992 and then T1 = Universal_Real
3994 (not Has_Fixed_Op (T1, Op_Id)
3995 or else Nkind (Parent (N)) = N_Type_Conversion)
3997 Add_One_Interp (N, Op_Id, Universal_Fixed);
3999 elsif Is_Numeric_Type (T1)
4000 and then Is_Numeric_Type (T2)
4001 and then (Covers (T1 => T1, T2 => T2)
4003 Covers (T1 => T2, T2 => T1))
4005 Add_One_Interp (N, Op_Id, Specific_Type (T1, T2));
4007 elsif Is_Fixed_Point_Type (T1)
4008 and then (Base_Type (T2) = Base_Type (Standard_Integer)
4009 or else T2 = Universal_Integer)
4011 Add_One_Interp (N, Op_Id, T1);
4013 elsif T2 = Universal_Real
4014 and then Base_Type (T1) = Base_Type (Standard_Integer)
4015 and then Op_Name = Name_Op_Multiply
4017 Add_One_Interp (N, Op_Id, Any_Fixed);
4019 elsif T1 = Universal_Real
4020 and then Base_Type (T2) = Base_Type (Standard_Integer)
4022 Add_One_Interp (N, Op_Id, Any_Fixed);
4024 elsif Is_Fixed_Point_Type (T2)
4025 and then (Base_Type (T1) = Base_Type (Standard_Integer)
4026 or else T1 = Universal_Integer)
4027 and then Op_Name = Name_Op_Multiply
4029 Add_One_Interp (N, Op_Id, T2);
4031 elsif T1 = Universal_Real and then T2 = Universal_Integer then
4032 Add_One_Interp (N, Op_Id, T1);
4034 elsif T2 = Universal_Real
4035 and then T1 = Universal_Integer
4036 and then Op_Name = Name_Op_Multiply
4038 Add_One_Interp (N, Op_Id, T2);
4041 elsif Op_Name = Name_Op_Mod or else Op_Name = Name_Op_Rem then
4043 -- Note: The fixed-point operands case with Treat_Fixed_As_Integer
4044 -- set does not require any special processing, since the Etype is
4045 -- already set (case of operation constructed by Exp_Fixed).
4047 if Is_Integer_Type (T1)
4048 and then (Covers (T1 => T1, T2 => T2)
4050 Covers (T1 => T2, T2 => T1))
4052 Add_One_Interp (N, Op_Id, Specific_Type (T1, T2));
4055 elsif Op_Name = Name_Op_Expon then
4056 if Is_Numeric_Type (T1)
4057 and then not Is_Fixed_Point_Type (T1)
4058 and then (Base_Type (T2) = Base_Type (Standard_Integer)
4059 or else T2 = Universal_Integer)
4061 Add_One_Interp (N, Op_Id, Base_Type (T1));
4064 else pragma Assert (Nkind (N) in N_Op_Shift);
4066 -- If not one of the predefined operators, the node may be one
4067 -- of the intrinsic functions. Its kind is always specific, and
4068 -- we can use it directly, rather than the name of the operation.
4070 if Is_Integer_Type (T1)
4071 and then (Base_Type (T2) = Base_Type (Standard_Integer)
4072 or else T2 = Universal_Integer)
4074 Add_One_Interp (N, Op_Id, Base_Type (T1));
4077 end Check_Arithmetic_Pair;
4079 -------------------------------
4080 -- Check_Misspelled_Selector --
4081 -------------------------------
4083 procedure Check_Misspelled_Selector
4084 (Prefix : Entity_Id;
4087 Max_Suggestions : constant := 2;
4088 Nr_Of_Suggestions : Natural := 0;
4090 Suggestion_1 : Entity_Id := Empty;
4091 Suggestion_2 : Entity_Id := Empty;
4096 -- All the components of the prefix of selector Sel are matched
4097 -- against Sel and a count is maintained of possible misspellings.
4098 -- When at the end of the analysis there are one or two (not more!)
4099 -- possible misspellings, these misspellings will be suggested as
4100 -- possible correction.
4102 if not (Is_Private_Type (Prefix) or else Is_Record_Type (Prefix)) then
4104 -- Concurrent types should be handled as well ???
4109 Comp := First_Entity (Prefix);
4110 while Nr_Of_Suggestions <= Max_Suggestions and then Present (Comp) loop
4111 if Is_Visible_Component (Comp) then
4112 if Is_Bad_Spelling_Of (Chars (Comp), Chars (Sel)) then
4113 Nr_Of_Suggestions := Nr_Of_Suggestions + 1;
4115 case Nr_Of_Suggestions is
4116 when 1 => Suggestion_1 := Comp;
4117 when 2 => Suggestion_2 := Comp;
4118 when others => exit;
4123 Comp := Next_Entity (Comp);
4126 -- Report at most two suggestions
4128 if Nr_Of_Suggestions = 1 then
4130 ("\possible misspelling of&", Sel, Suggestion_1);
4132 elsif Nr_Of_Suggestions = 2 then
4133 Error_Msg_Node_2 := Suggestion_2;
4135 ("\possible misspelling of& or&", Sel, Suggestion_1);
4137 end Check_Misspelled_Selector;
4139 ----------------------
4140 -- Defined_In_Scope --
4141 ----------------------
4143 function Defined_In_Scope (T : Entity_Id; S : Entity_Id) return Boolean
4145 S1 : constant Entity_Id := Scope (Base_Type (T));
4148 or else (S1 = System_Aux_Id and then S = Scope (S1));
4149 end Defined_In_Scope;
4155 procedure Diagnose_Call (N : Node_Id; Nam : Node_Id) is
4161 Void_Interp_Seen : Boolean := False;
4164 pragma Warnings (Off, Boolean);
4167 if Ada_Version >= Ada_05 then
4168 Actual := First_Actual (N);
4169 while Present (Actual) loop
4171 -- Ada 2005 (AI-50217): Post an error in case of premature
4172 -- usage of an entity from the limited view.
4174 if not Analyzed (Etype (Actual))
4175 and then From_With_Type (Etype (Actual))
4177 Error_Msg_Qual_Level := 1;
4179 ("missing with_clause for scope of imported type&",
4180 Actual, Etype (Actual));
4181 Error_Msg_Qual_Level := 0;
4184 Next_Actual (Actual);
4188 -- Analyze each candidate call again, with full error reporting
4192 ("no candidate interpretations match the actuals:!", Nam);
4193 Err_Mode := All_Errors_Mode;
4194 All_Errors_Mode := True;
4196 -- If this is a call to an operation of a concurrent type,
4197 -- the failed interpretations have been removed from the
4198 -- name. Recover them to provide full diagnostics.
4200 if Nkind (Parent (Nam)) = N_Selected_Component then
4201 Set_Entity (Nam, Empty);
4202 New_Nam := New_Copy_Tree (Parent (Nam));
4203 Set_Is_Overloaded (New_Nam, False);
4204 Set_Is_Overloaded (Selector_Name (New_Nam), False);
4205 Set_Parent (New_Nam, Parent (Parent (Nam)));
4206 Analyze_Selected_Component (New_Nam);
4207 Get_First_Interp (Selector_Name (New_Nam), X, It);
4209 Get_First_Interp (Nam, X, It);
4212 while Present (It.Nam) loop
4213 if Etype (It.Nam) = Standard_Void_Type then
4214 Void_Interp_Seen := True;
4217 Analyze_One_Call (N, It.Nam, True, Success);
4218 Get_Next_Interp (X, It);
4221 if Nkind (N) = N_Function_Call then
4222 Get_First_Interp (Nam, X, It);
4223 while Present (It.Nam) loop
4224 if Ekind (It.Nam) = E_Function
4225 or else Ekind (It.Nam) = E_Operator
4229 Get_Next_Interp (X, It);
4233 -- If all interpretations are procedures, this deserves a
4234 -- more precise message. Ditto if this appears as the prefix
4235 -- of a selected component, which may be a lexical error.
4238 ("\context requires function call, found procedure name", Nam);
4240 if Nkind (Parent (N)) = N_Selected_Component
4241 and then N = Prefix (Parent (N))
4244 "\period should probably be semicolon", Parent (N));
4247 elsif Nkind (N) = N_Procedure_Call_Statement
4248 and then not Void_Interp_Seen
4251 "\function name found in procedure call", Nam);
4254 All_Errors_Mode := Err_Mode;
4257 ---------------------------
4258 -- Find_Arithmetic_Types --
4259 ---------------------------
4261 procedure Find_Arithmetic_Types
4266 Index1 : Interp_Index;
4267 Index2 : Interp_Index;
4271 procedure Check_Right_Argument (T : Entity_Id);
4272 -- Check right operand of operator
4274 --------------------------
4275 -- Check_Right_Argument --
4276 --------------------------
4278 procedure Check_Right_Argument (T : Entity_Id) is
4280 if not Is_Overloaded (R) then
4281 Check_Arithmetic_Pair (T, Etype (R), Op_Id, N);
4283 Get_First_Interp (R, Index2, It2);
4284 while Present (It2.Typ) loop
4285 Check_Arithmetic_Pair (T, It2.Typ, Op_Id, N);
4286 Get_Next_Interp (Index2, It2);
4289 end Check_Right_Argument;
4291 -- Start processing for Find_Arithmetic_Types
4294 if not Is_Overloaded (L) then
4295 Check_Right_Argument (Etype (L));
4298 Get_First_Interp (L, Index1, It1);
4299 while Present (It1.Typ) loop
4300 Check_Right_Argument (It1.Typ);
4301 Get_Next_Interp (Index1, It1);
4305 end Find_Arithmetic_Types;
4307 ------------------------
4308 -- Find_Boolean_Types --
4309 ------------------------
4311 procedure Find_Boolean_Types
4316 Index : Interp_Index;
4319 procedure Check_Numeric_Argument (T : Entity_Id);
4320 -- Special case for logical operations one of whose operands is an
4321 -- integer literal. If both are literal the result is any modular type.
4323 ----------------------------
4324 -- Check_Numeric_Argument --
4325 ----------------------------
4327 procedure Check_Numeric_Argument (T : Entity_Id) is
4329 if T = Universal_Integer then
4330 Add_One_Interp (N, Op_Id, Any_Modular);
4332 elsif Is_Modular_Integer_Type (T) then
4333 Add_One_Interp (N, Op_Id, T);
4335 end Check_Numeric_Argument;
4337 -- Start of processing for Find_Boolean_Types
4340 if not Is_Overloaded (L) then
4341 if Etype (L) = Universal_Integer
4342 or else Etype (L) = Any_Modular
4344 if not Is_Overloaded (R) then
4345 Check_Numeric_Argument (Etype (R));
4348 Get_First_Interp (R, Index, It);
4349 while Present (It.Typ) loop
4350 Check_Numeric_Argument (It.Typ);
4351 Get_Next_Interp (Index, It);
4355 -- If operands are aggregates, we must assume that they may be
4356 -- boolean arrays, and leave disambiguation for the second pass.
4357 -- If only one is an aggregate, verify that the other one has an
4358 -- interpretation as a boolean array
4360 elsif Nkind (L) = N_Aggregate then
4361 if Nkind (R) = N_Aggregate then
4362 Add_One_Interp (N, Op_Id, Etype (L));
4364 elsif not Is_Overloaded (R) then
4365 if Valid_Boolean_Arg (Etype (R)) then
4366 Add_One_Interp (N, Op_Id, Etype (R));
4370 Get_First_Interp (R, Index, It);
4371 while Present (It.Typ) loop
4372 if Valid_Boolean_Arg (It.Typ) then
4373 Add_One_Interp (N, Op_Id, It.Typ);
4376 Get_Next_Interp (Index, It);
4380 elsif Valid_Boolean_Arg (Etype (L))
4381 and then Has_Compatible_Type (R, Etype (L))
4383 Add_One_Interp (N, Op_Id, Etype (L));
4387 Get_First_Interp (L, Index, It);
4388 while Present (It.Typ) loop
4389 if Valid_Boolean_Arg (It.Typ)
4390 and then Has_Compatible_Type (R, It.Typ)
4392 Add_One_Interp (N, Op_Id, It.Typ);
4395 Get_Next_Interp (Index, It);
4398 end Find_Boolean_Types;
4400 ---------------------------
4401 -- Find_Comparison_Types --
4402 ---------------------------
4404 procedure Find_Comparison_Types
4409 Index : Interp_Index;
4411 Found : Boolean := False;
4414 Scop : Entity_Id := Empty;
4416 procedure Try_One_Interp (T1 : Entity_Id);
4417 -- Routine to try one proposed interpretation. Note that the context
4418 -- of the operator plays no role in resolving the arguments, so that
4419 -- if there is more than one interpretation of the operands that is
4420 -- compatible with comparison, the operation is ambiguous.
4422 --------------------
4423 -- Try_One_Interp --
4424 --------------------
4426 procedure Try_One_Interp (T1 : Entity_Id) is
4429 -- If the operator is an expanded name, then the type of the operand
4430 -- must be defined in the corresponding scope. If the type is
4431 -- universal, the context will impose the correct type.
4434 and then not Defined_In_Scope (T1, Scop)
4435 and then T1 /= Universal_Integer
4436 and then T1 /= Universal_Real
4437 and then T1 /= Any_String
4438 and then T1 /= Any_Composite
4443 if Valid_Comparison_Arg (T1)
4444 and then Has_Compatible_Type (R, T1)
4447 and then Base_Type (T1) /= Base_Type (T_F)
4449 It := Disambiguate (L, I_F, Index, Any_Type);
4451 if It = No_Interp then
4452 Ambiguous_Operands (N);
4453 Set_Etype (L, Any_Type);
4467 Find_Non_Universal_Interpretations (N, R, Op_Id, T1);
4472 -- Start processing for Find_Comparison_Types
4475 -- If left operand is aggregate, the right operand has to
4476 -- provide a usable type for it.
4478 if Nkind (L) = N_Aggregate
4479 and then Nkind (R) /= N_Aggregate
4481 Find_Comparison_Types (L => R, R => L, Op_Id => Op_Id, N => N);
4485 if Nkind (N) = N_Function_Call
4486 and then Nkind (Name (N)) = N_Expanded_Name
4488 Scop := Entity (Prefix (Name (N)));
4490 -- The prefix may be a package renaming, and the subsequent test
4491 -- requires the original package.
4493 if Ekind (Scop) = E_Package
4494 and then Present (Renamed_Entity (Scop))
4496 Scop := Renamed_Entity (Scop);
4497 Set_Entity (Prefix (Name (N)), Scop);
4501 if not Is_Overloaded (L) then
4502 Try_One_Interp (Etype (L));
4505 Get_First_Interp (L, Index, It);
4506 while Present (It.Typ) loop
4507 Try_One_Interp (It.Typ);
4508 Get_Next_Interp (Index, It);
4511 end Find_Comparison_Types;
4513 ----------------------------------------
4514 -- Find_Non_Universal_Interpretations --
4515 ----------------------------------------
4517 procedure Find_Non_Universal_Interpretations
4523 Index : Interp_Index;
4527 if T1 = Universal_Integer
4528 or else T1 = Universal_Real
4530 if not Is_Overloaded (R) then
4532 (N, Op_Id, Standard_Boolean, Base_Type (Etype (R)));
4534 Get_First_Interp (R, Index, It);
4535 while Present (It.Typ) loop
4536 if Covers (It.Typ, T1) then
4538 (N, Op_Id, Standard_Boolean, Base_Type (It.Typ));
4541 Get_Next_Interp (Index, It);
4545 Add_One_Interp (N, Op_Id, Standard_Boolean, Base_Type (T1));
4547 end Find_Non_Universal_Interpretations;
4549 ------------------------------
4550 -- Find_Concatenation_Types --
4551 ------------------------------
4553 procedure Find_Concatenation_Types
4558 Op_Type : constant Entity_Id := Etype (Op_Id);
4561 if Is_Array_Type (Op_Type)
4562 and then not Is_Limited_Type (Op_Type)
4564 and then (Has_Compatible_Type (L, Op_Type)
4566 Has_Compatible_Type (L, Component_Type (Op_Type)))
4568 and then (Has_Compatible_Type (R, Op_Type)
4570 Has_Compatible_Type (R, Component_Type (Op_Type)))
4572 Add_One_Interp (N, Op_Id, Op_Type);
4574 end Find_Concatenation_Types;
4576 -------------------------
4577 -- Find_Equality_Types --
4578 -------------------------
4580 procedure Find_Equality_Types
4585 Index : Interp_Index;
4587 Found : Boolean := False;
4590 Scop : Entity_Id := Empty;
4592 procedure Try_One_Interp (T1 : Entity_Id);
4593 -- The context of the operator plays no role in resolving the
4594 -- arguments, so that if there is more than one interpretation
4595 -- of the operands that is compatible with equality, the construct
4596 -- is ambiguous and an error can be emitted now, after trying to
4597 -- disambiguate, i.e. applying preference rules.
4599 --------------------
4600 -- Try_One_Interp --
4601 --------------------
4603 procedure Try_One_Interp (T1 : Entity_Id) is
4605 -- If the operator is an expanded name, then the type of the operand
4606 -- must be defined in the corresponding scope. If the type is
4607 -- universal, the context will impose the correct type. An anonymous
4608 -- type for a 'Access reference is also universal in this sense, as
4609 -- the actual type is obtained from context.
4610 -- In Ada 2005, the equality operator for anonymous access types
4611 -- is declared in Standard, and preference rules apply to it.
4613 if Present (Scop) then
4614 if Defined_In_Scope (T1, Scop)
4615 or else T1 = Universal_Integer
4616 or else T1 = Universal_Real
4617 or else T1 = Any_Access
4618 or else T1 = Any_String
4619 or else T1 = Any_Composite
4620 or else (Ekind (T1) = E_Access_Subprogram_Type
4621 and then not Comes_From_Source (T1))
4625 elsif Ekind (T1) = E_Anonymous_Access_Type
4626 and then Scop = Standard_Standard
4631 -- The scope does not contain an operator for the type
4637 -- Ada 2005 (AI-230): Keep restriction imposed by Ada 83 and 95:
4638 -- Do not allow anonymous access types in equality operators.
4640 if Ada_Version < Ada_05
4641 and then Ekind (T1) = E_Anonymous_Access_Type
4646 if T1 /= Standard_Void_Type
4647 and then not Is_Limited_Type (T1)
4648 and then not Is_Limited_Composite (T1)
4649 and then Has_Compatible_Type (R, T1)
4652 and then Base_Type (T1) /= Base_Type (T_F)
4654 It := Disambiguate (L, I_F, Index, Any_Type);
4656 if It = No_Interp then
4657 Ambiguous_Operands (N);
4658 Set_Etype (L, Any_Type);
4671 if not Analyzed (L) then
4675 Find_Non_Universal_Interpretations (N, R, Op_Id, T1);
4677 -- Case of operator was not visible, Etype still set to Any_Type
4679 if Etype (N) = Any_Type then
4683 elsif Scop = Standard_Standard
4684 and then Ekind (T1) = E_Anonymous_Access_Type
4690 -- Start of processing for Find_Equality_Types
4693 -- If left operand is aggregate, the right operand has to
4694 -- provide a usable type for it.
4696 if Nkind (L) = N_Aggregate
4697 and then Nkind (R) /= N_Aggregate
4699 Find_Equality_Types (L => R, R => L, Op_Id => Op_Id, N => N);
4703 if Nkind (N) = N_Function_Call
4704 and then Nkind (Name (N)) = N_Expanded_Name
4706 Scop := Entity (Prefix (Name (N)));
4708 -- The prefix may be a package renaming, and the subsequent test
4709 -- requires the original package.
4711 if Ekind (Scop) = E_Package
4712 and then Present (Renamed_Entity (Scop))
4714 Scop := Renamed_Entity (Scop);
4715 Set_Entity (Prefix (Name (N)), Scop);
4719 if not Is_Overloaded (L) then
4720 Try_One_Interp (Etype (L));
4723 Get_First_Interp (L, Index, It);
4724 while Present (It.Typ) loop
4725 Try_One_Interp (It.Typ);
4726 Get_Next_Interp (Index, It);
4729 end Find_Equality_Types;
4731 -------------------------
4732 -- Find_Negation_Types --
4733 -------------------------
4735 procedure Find_Negation_Types
4740 Index : Interp_Index;
4744 if not Is_Overloaded (R) then
4745 if Etype (R) = Universal_Integer then
4746 Add_One_Interp (N, Op_Id, Any_Modular);
4747 elsif Valid_Boolean_Arg (Etype (R)) then
4748 Add_One_Interp (N, Op_Id, Etype (R));
4752 Get_First_Interp (R, Index, It);
4753 while Present (It.Typ) loop
4754 if Valid_Boolean_Arg (It.Typ) then
4755 Add_One_Interp (N, Op_Id, It.Typ);
4758 Get_Next_Interp (Index, It);
4761 end Find_Negation_Types;
4763 ------------------------------
4764 -- Find_Primitive_Operation --
4765 ------------------------------
4767 function Find_Primitive_Operation (N : Node_Id) return Boolean is
4768 Obj : constant Node_Id := Prefix (N);
4769 Op : constant Node_Id := Selector_Name (N);
4776 Set_Etype (Op, Any_Type);
4778 if Is_Access_Type (Etype (Obj)) then
4779 Typ := Designated_Type (Etype (Obj));
4784 if Is_Class_Wide_Type (Typ) then
4785 Typ := Root_Type (Typ);
4788 Prims := Primitive_Operations (Typ);
4790 Prim := First_Elmt (Prims);
4791 while Present (Prim) loop
4792 if Chars (Node (Prim)) = Chars (Op) then
4793 Add_One_Interp (Op, Node (Prim), Etype (Node (Prim)));
4794 Set_Etype (N, Etype (Node (Prim)));
4800 -- Now look for class-wide operations of the type or any of its
4801 -- ancestors by iterating over the homonyms of the selector.
4804 Cls_Type : constant Entity_Id := Class_Wide_Type (Typ);
4808 Hom := Current_Entity (Op);
4809 while Present (Hom) loop
4810 if (Ekind (Hom) = E_Procedure
4812 Ekind (Hom) = E_Function)
4813 and then Scope (Hom) = Scope (Typ)
4814 and then Present (First_Formal (Hom))
4816 (Base_Type (Etype (First_Formal (Hom))) = Cls_Type
4818 (Is_Access_Type (Etype (First_Formal (Hom)))
4820 Ekind (Etype (First_Formal (Hom))) =
4821 E_Anonymous_Access_Type
4824 (Designated_Type (Etype (First_Formal (Hom)))) =
4827 Add_One_Interp (Op, Hom, Etype (Hom));
4828 Set_Etype (N, Etype (Hom));
4831 Hom := Homonym (Hom);
4835 return Etype (Op) /= Any_Type;
4836 end Find_Primitive_Operation;
4838 ----------------------
4839 -- Find_Unary_Types --
4840 ----------------------
4842 procedure Find_Unary_Types
4847 Index : Interp_Index;
4851 if not Is_Overloaded (R) then
4852 if Is_Numeric_Type (Etype (R)) then
4853 Add_One_Interp (N, Op_Id, Base_Type (Etype (R)));
4857 Get_First_Interp (R, Index, It);
4858 while Present (It.Typ) loop
4859 if Is_Numeric_Type (It.Typ) then
4860 Add_One_Interp (N, Op_Id, Base_Type (It.Typ));
4863 Get_Next_Interp (Index, It);
4866 end Find_Unary_Types;
4872 function Junk_Operand (N : Node_Id) return Boolean is
4876 if Error_Posted (N) then
4880 -- Get entity to be tested
4882 if Is_Entity_Name (N)
4883 and then Present (Entity (N))
4887 -- An odd case, a procedure name gets converted to a very peculiar
4888 -- function call, and here is where we detect this happening.
4890 elsif Nkind (N) = N_Function_Call
4891 and then Is_Entity_Name (Name (N))
4892 and then Present (Entity (Name (N)))
4896 -- Another odd case, there are at least some cases of selected
4897 -- components where the selected component is not marked as having
4898 -- an entity, even though the selector does have an entity
4900 elsif Nkind (N) = N_Selected_Component
4901 and then Present (Entity (Selector_Name (N)))
4903 Enode := Selector_Name (N);
4909 -- Now test the entity we got to see if it is a bad case
4911 case Ekind (Entity (Enode)) is
4915 ("package name cannot be used as operand", Enode);
4917 when Generic_Unit_Kind =>
4919 ("generic unit name cannot be used as operand", Enode);
4923 ("subtype name cannot be used as operand", Enode);
4927 ("entry name cannot be used as operand", Enode);
4931 ("procedure name cannot be used as operand", Enode);
4935 ("exception name cannot be used as operand", Enode);
4937 when E_Block | E_Label | E_Loop =>
4939 ("label name cannot be used as operand", Enode);
4949 --------------------
4950 -- Operator_Check --
4951 --------------------
4953 procedure Operator_Check (N : Node_Id) is
4955 Remove_Abstract_Operations (N);
4957 -- Test for case of no interpretation found for operator
4959 if Etype (N) = Any_Type then
4963 Op_Id : Entity_Id := Empty;
4966 R := Right_Opnd (N);
4968 if Nkind (N) in N_Binary_Op then
4974 -- If either operand has no type, then don't complain further,
4975 -- since this simply means that we have a propagated error.
4978 or else Etype (R) = Any_Type
4979 or else (Nkind (N) in N_Binary_Op and then Etype (L) = Any_Type)
4983 -- We explicitly check for the case of concatenation of component
4984 -- with component to avoid reporting spurious matching array types
4985 -- that might happen to be lurking in distant packages (such as
4986 -- run-time packages). This also prevents inconsistencies in the
4987 -- messages for certain ACVC B tests, which can vary depending on
4988 -- types declared in run-time interfaces. Another improvement when
4989 -- aggregates are present is to look for a well-typed operand.
4991 elsif Present (Candidate_Type)
4992 and then (Nkind (N) /= N_Op_Concat
4993 or else Is_Array_Type (Etype (L))
4994 or else Is_Array_Type (Etype (R)))
4997 if Nkind (N) = N_Op_Concat then
4998 if Etype (L) /= Any_Composite
4999 and then Is_Array_Type (Etype (L))
5001 Candidate_Type := Etype (L);
5003 elsif Etype (R) /= Any_Composite
5004 and then Is_Array_Type (Etype (R))
5006 Candidate_Type := Etype (R);
5011 ("operator for} is not directly visible!",
5012 N, First_Subtype (Candidate_Type));
5013 Error_Msg_N ("use clause would make operation legal!", N);
5016 -- If either operand is a junk operand (e.g. package name), then
5017 -- post appropriate error messages, but do not complain further.
5019 -- Note that the use of OR in this test instead of OR ELSE is
5020 -- quite deliberate, we may as well check both operands in the
5021 -- binary operator case.
5023 elsif Junk_Operand (R)
5024 or (Nkind (N) in N_Binary_Op and then Junk_Operand (L))
5028 -- If we have a logical operator, one of whose operands is
5029 -- Boolean, then we know that the other operand cannot resolve to
5030 -- Boolean (since we got no interpretations), but in that case we
5031 -- pretty much know that the other operand should be Boolean, so
5032 -- resolve it that way (generating an error)
5034 elsif Nkind_In (N, N_Op_And, N_Op_Or, N_Op_Xor) then
5035 if Etype (L) = Standard_Boolean then
5036 Resolve (R, Standard_Boolean);
5038 elsif Etype (R) = Standard_Boolean then
5039 Resolve (L, Standard_Boolean);
5043 -- For an arithmetic operator or comparison operator, if one
5044 -- of the operands is numeric, then we know the other operand
5045 -- is not the same numeric type. If it is a non-numeric type,
5046 -- then probably it is intended to match the other operand.
5048 elsif Nkind_In (N, N_Op_Add,
5054 Nkind_In (N, N_Op_Lt,
5060 if Is_Numeric_Type (Etype (L))
5061 and then not Is_Numeric_Type (Etype (R))
5063 Resolve (R, Etype (L));
5066 elsif Is_Numeric_Type (Etype (R))
5067 and then not Is_Numeric_Type (Etype (L))
5069 Resolve (L, Etype (R));
5073 -- Comparisons on A'Access are common enough to deserve a
5076 elsif Nkind_In (N, N_Op_Eq, N_Op_Ne)
5077 and then Ekind (Etype (L)) = E_Access_Attribute_Type
5078 and then Ekind (Etype (R)) = E_Access_Attribute_Type
5081 ("two access attributes cannot be compared directly", N);
5083 ("\use qualified expression for one of the operands",
5087 -- Another one for C programmers
5089 elsif Nkind (N) = N_Op_Concat
5090 and then Valid_Boolean_Arg (Etype (L))
5091 and then Valid_Boolean_Arg (Etype (R))
5093 Error_Msg_N ("invalid operands for concatenation", N);
5094 Error_Msg_N ("\maybe AND was meant", N);
5097 -- A special case for comparison of access parameter with null
5099 elsif Nkind (N) = N_Op_Eq
5100 and then Is_Entity_Name (L)
5101 and then Nkind (Parent (Entity (L))) = N_Parameter_Specification
5102 and then Nkind (Parameter_Type (Parent (Entity (L)))) =
5104 and then Nkind (R) = N_Null
5106 Error_Msg_N ("access parameter is not allowed to be null", L);
5107 Error_Msg_N ("\(call would raise Constraint_Error)", L);
5111 -- If we fall through then just give general message. Note that in
5112 -- the following messages, if the operand is overloaded we choose
5113 -- an arbitrary type to complain about, but that is probably more
5114 -- useful than not giving a type at all.
5116 if Nkind (N) in N_Unary_Op then
5117 Error_Msg_Node_2 := Etype (R);
5118 Error_Msg_N ("operator& not defined for}", N);
5122 if Nkind (N) in N_Binary_Op then
5123 if not Is_Overloaded (L)
5124 and then not Is_Overloaded (R)
5125 and then Base_Type (Etype (L)) = Base_Type (Etype (R))
5127 Error_Msg_Node_2 := First_Subtype (Etype (R));
5128 Error_Msg_N ("there is no applicable operator& for}", N);
5131 -- Another attempt to find a fix: one of the candidate
5132 -- interpretations may not be use-visible. This has
5133 -- already been checked for predefined operators, so
5134 -- we examine only user-defined functions.
5136 Op_Id := Get_Name_Entity_Id (Chars (N));
5138 while Present (Op_Id) loop
5139 if Ekind (Op_Id) /= E_Operator
5140 and then Is_Overloadable (Op_Id)
5142 if not Is_Immediately_Visible (Op_Id)
5143 and then not In_Use (Scope (Op_Id))
5144 and then not Is_Abstract_Subprogram (Op_Id)
5145 and then not Is_Hidden (Op_Id)
5146 and then Ekind (Scope (Op_Id)) = E_Package
5149 (L, Etype (First_Formal (Op_Id)))
5151 (Next_Formal (First_Formal (Op_Id)))
5155 Etype (Next_Formal (First_Formal (Op_Id))))
5158 ("No legal interpretation for operator&", N);
5160 ("\use clause on& would make operation legal",
5166 Op_Id := Homonym (Op_Id);
5170 Error_Msg_N ("invalid operand types for operator&", N);
5172 if Nkind (N) /= N_Op_Concat then
5173 Error_Msg_NE ("\left operand has}!", N, Etype (L));
5174 Error_Msg_NE ("\right operand has}!", N, Etype (R));
5184 -----------------------------------------
5185 -- Process_Implicit_Dereference_Prefix --
5186 -----------------------------------------
5188 function Process_Implicit_Dereference_Prefix
5190 P : Entity_Id) return Entity_Id
5193 Typ : constant Entity_Id := Designated_Type (Etype (P));
5197 and then (Operating_Mode = Check_Semantics or else not Expander_Active)
5199 -- We create a dummy reference to E to ensure that the reference
5200 -- is not considered as part of an assignment (an implicit
5201 -- dereference can never assign to its prefix). The Comes_From_Source
5202 -- attribute needs to be propagated for accurate warnings.
5204 Ref := New_Reference_To (E, Sloc (P));
5205 Set_Comes_From_Source (Ref, Comes_From_Source (P));
5206 Generate_Reference (E, Ref);
5209 -- An implicit dereference is a legal occurrence of an
5210 -- incomplete type imported through a limited_with clause,
5211 -- if the full view is visible.
5213 if From_With_Type (Typ)
5214 and then not From_With_Type (Scope (Typ))
5216 (Is_Immediately_Visible (Scope (Typ))
5218 (Is_Child_Unit (Scope (Typ))
5219 and then Is_Visible_Child_Unit (Scope (Typ))))
5221 return Available_View (Typ);
5226 end Process_Implicit_Dereference_Prefix;
5228 --------------------------------
5229 -- Remove_Abstract_Operations --
5230 --------------------------------
5232 procedure Remove_Abstract_Operations (N : Node_Id) is
5233 Abstract_Op : Entity_Id := Empty;
5234 Address_Kludge : Boolean := False;
5238 -- AI-310: If overloaded, remove abstract non-dispatching operations. We
5239 -- activate this if either extensions are enabled, or if the abstract
5240 -- operation in question comes from a predefined file. This latter test
5241 -- allows us to use abstract to make operations invisible to users. In
5242 -- particular, if type Address is non-private and abstract subprograms
5243 -- are used to hide its operators, they will be truly hidden.
5245 type Operand_Position is (First_Op, Second_Op);
5246 Univ_Type : constant Entity_Id := Universal_Interpretation (N);
5248 procedure Remove_Address_Interpretations (Op : Operand_Position);
5249 -- Ambiguities may arise when the operands are literal and the address
5250 -- operations in s-auxdec are visible. In that case, remove the
5251 -- interpretation of a literal as Address, to retain the semantics of
5252 -- Address as a private type.
5254 ------------------------------------
5255 -- Remove_Address_Interpretations --
5256 ------------------------------------
5258 procedure Remove_Address_Interpretations (Op : Operand_Position) is
5262 if Is_Overloaded (N) then
5263 Get_First_Interp (N, I, It);
5264 while Present (It.Nam) loop
5265 Formal := First_Entity (It.Nam);
5267 if Op = Second_Op then
5268 Formal := Next_Entity (Formal);
5271 if Is_Descendent_Of_Address (Etype (Formal)) then
5272 Address_Kludge := True;
5276 Get_Next_Interp (I, It);
5279 end Remove_Address_Interpretations;
5281 -- Start of processing for Remove_Abstract_Operations
5284 if Is_Overloaded (N) then
5285 Get_First_Interp (N, I, It);
5287 while Present (It.Nam) loop
5288 if Is_Overloadable (It.Nam)
5289 and then Is_Abstract_Subprogram (It.Nam)
5290 and then not Is_Dispatching_Operation (It.Nam)
5292 Abstract_Op := It.Nam;
5294 if Is_Descendent_Of_Address (It.Typ) then
5295 Address_Kludge := True;
5299 -- In Ada 2005, this operation does not participate in Overload
5300 -- resolution. If the operation is defined in a predefined
5301 -- unit, it is one of the operations declared abstract in some
5302 -- variants of System, and it must be removed as well.
5304 elsif Ada_Version >= Ada_05
5305 or else Is_Predefined_File_Name
5306 (Unit_File_Name (Get_Source_Unit (It.Nam)))
5313 Get_Next_Interp (I, It);
5316 if No (Abstract_Op) then
5318 -- If some interpretation yields an integer type, it is still
5319 -- possible that there are address interpretations. Remove them
5320 -- if one operand is a literal, to avoid spurious ambiguities
5321 -- on systems where Address is a visible integer type.
5323 if Is_Overloaded (N)
5324 and then Nkind (N) in N_Op
5325 and then Is_Integer_Type (Etype (N))
5327 if Nkind (N) in N_Binary_Op then
5328 if Nkind (Right_Opnd (N)) = N_Integer_Literal then
5329 Remove_Address_Interpretations (Second_Op);
5331 elsif Nkind (Right_Opnd (N)) = N_Integer_Literal then
5332 Remove_Address_Interpretations (First_Op);
5337 elsif Nkind (N) in N_Op then
5339 -- Remove interpretations that treat literals as addresses. This
5340 -- is never appropriate, even when Address is defined as a visible
5341 -- Integer type. The reason is that we would really prefer Address
5342 -- to behave as a private type, even in this case, which is there
5343 -- only to accomodate oddities of VMS address sizes. If Address is
5344 -- a visible integer type, we get lots of overload ambiguities.
5346 if Nkind (N) in N_Binary_Op then
5348 U1 : constant Boolean :=
5349 Present (Universal_Interpretation (Right_Opnd (N)));
5350 U2 : constant Boolean :=
5351 Present (Universal_Interpretation (Left_Opnd (N)));
5355 Remove_Address_Interpretations (Second_Op);
5359 Remove_Address_Interpretations (First_Op);
5362 if not (U1 and U2) then
5364 -- Remove corresponding predefined operator, which is
5365 -- always added to the overload set.
5367 Get_First_Interp (N, I, It);
5368 while Present (It.Nam) loop
5369 if Scope (It.Nam) = Standard_Standard
5370 and then Base_Type (It.Typ) =
5371 Base_Type (Etype (Abstract_Op))
5376 Get_Next_Interp (I, It);
5379 elsif Is_Overloaded (N)
5380 and then Present (Univ_Type)
5382 -- If both operands have a universal interpretation,
5383 -- it is still necessary to remove interpretations that
5384 -- yield Address. Any remaining ambiguities will be
5385 -- removed in Disambiguate.
5387 Get_First_Interp (N, I, It);
5388 while Present (It.Nam) loop
5389 if Is_Descendent_Of_Address (It.Typ) then
5392 elsif not Is_Type (It.Nam) then
5393 Set_Entity (N, It.Nam);
5396 Get_Next_Interp (I, It);
5402 elsif Nkind (N) = N_Function_Call
5404 (Nkind (Name (N)) = N_Operator_Symbol
5406 (Nkind (Name (N)) = N_Expanded_Name
5408 Nkind (Selector_Name (Name (N))) = N_Operator_Symbol))
5412 Arg1 : constant Node_Id := First (Parameter_Associations (N));
5413 U1 : constant Boolean :=
5414 Present (Universal_Interpretation (Arg1));
5415 U2 : constant Boolean :=
5416 Present (Next (Arg1)) and then
5417 Present (Universal_Interpretation (Next (Arg1)));
5421 Remove_Address_Interpretations (First_Op);
5425 Remove_Address_Interpretations (Second_Op);
5428 if not (U1 and U2) then
5429 Get_First_Interp (N, I, It);
5430 while Present (It.Nam) loop
5431 if Scope (It.Nam) = Standard_Standard
5432 and then It.Typ = Base_Type (Etype (Abstract_Op))
5437 Get_Next_Interp (I, It);
5443 -- If the removal has left no valid interpretations, emit an error
5444 -- message now and label node as illegal.
5446 if Present (Abstract_Op) then
5447 Get_First_Interp (N, I, It);
5451 -- Removal of abstract operation left no viable candidate
5453 Set_Etype (N, Any_Type);
5454 Error_Msg_Sloc := Sloc (Abstract_Op);
5456 ("cannot call abstract operation& declared#", N, Abstract_Op);
5458 -- In Ada 2005, an abstract operation may disable predefined
5459 -- operators. Since the context is not yet known, we mark the
5460 -- predefined operators as potentially hidden. Do not include
5461 -- predefined operators when addresses are involved since this
5462 -- case is handled separately.
5464 elsif Ada_Version >= Ada_05
5465 and then not Address_Kludge
5467 while Present (It.Nam) loop
5468 if Is_Numeric_Type (It.Typ)
5469 and then Scope (It.Typ) = Standard_Standard
5471 Set_Abstract_Op (I, Abstract_Op);
5474 Get_Next_Interp (I, It);
5479 end Remove_Abstract_Operations;
5481 -----------------------
5482 -- Try_Indirect_Call --
5483 -----------------------
5485 function Try_Indirect_Call
5488 Typ : Entity_Id) return Boolean
5494 pragma Warnings (Off, Call_OK);
5497 Normalize_Actuals (N, Designated_Type (Typ), False, Call_OK);
5499 Actual := First_Actual (N);
5500 Formal := First_Formal (Designated_Type (Typ));
5501 while Present (Actual) and then Present (Formal) loop
5502 if not Has_Compatible_Type (Actual, Etype (Formal)) then
5507 Next_Formal (Formal);
5510 if No (Actual) and then No (Formal) then
5511 Add_One_Interp (N, Nam, Etype (Designated_Type (Typ)));
5513 -- Nam is a candidate interpretation for the name in the call,
5514 -- if it is not an indirect call.
5516 if not Is_Type (Nam)
5517 and then Is_Entity_Name (Name (N))
5519 Set_Entity (Name (N), Nam);
5526 end Try_Indirect_Call;
5528 ----------------------
5529 -- Try_Indexed_Call --
5530 ----------------------
5532 function Try_Indexed_Call
5536 Skip_First : Boolean) return Boolean
5538 Actuals : constant List_Id := Parameter_Associations (N);
5543 Actual := First (Actuals);
5545 -- If the call was originally written in prefix form, skip the first
5546 -- actual, which is obviously not defaulted.
5552 Index := First_Index (Typ);
5553 while Present (Actual) and then Present (Index) loop
5555 -- If the parameter list has a named association, the expression
5556 -- is definitely a call and not an indexed component.
5558 if Nkind (Actual) = N_Parameter_Association then
5562 if not Has_Compatible_Type (Actual, Etype (Index)) then
5570 if No (Actual) and then No (Index) then
5571 Add_One_Interp (N, Nam, Component_Type (Typ));
5573 -- Nam is a candidate interpretation for the name in the call,
5574 -- if it is not an indirect call.
5576 if not Is_Type (Nam)
5577 and then Is_Entity_Name (Name (N))
5579 Set_Entity (Name (N), Nam);
5586 end Try_Indexed_Call;
5588 --------------------------
5589 -- Try_Object_Operation --
5590 --------------------------
5592 function Try_Object_Operation (N : Node_Id) return Boolean is
5593 K : constant Node_Kind := Nkind (Parent (N));
5594 Is_Subprg_Call : constant Boolean := Nkind_In
5595 (K, N_Procedure_Call_Statement,
5597 Loc : constant Source_Ptr := Sloc (N);
5598 Obj : constant Node_Id := Prefix (N);
5599 Subprog : constant Node_Id :=
5600 Make_Identifier (Sloc (Selector_Name (N)),
5601 Chars => Chars (Selector_Name (N)));
5602 -- Identifier on which possible interpretations will be collected
5604 Report_Error : Boolean := False;
5605 -- If no candidate interpretation matches the context, redo the
5606 -- analysis with error enabled to provide additional information.
5609 Candidate : Entity_Id := Empty;
5610 New_Call_Node : Node_Id := Empty;
5611 Node_To_Replace : Node_Id;
5612 Obj_Type : Entity_Id := Etype (Obj);
5613 Success : Boolean := False;
5615 function Valid_Candidate
5618 Subp : Entity_Id) return Entity_Id;
5619 -- If the subprogram is a valid interpretation, record it, and add
5620 -- to the list of interpretations of Subprog.
5622 procedure Complete_Object_Operation
5623 (Call_Node : Node_Id;
5624 Node_To_Replace : Node_Id);
5625 -- Make Subprog the name of Call_Node, replace Node_To_Replace with
5626 -- Call_Node, insert the object (or its dereference) as the first actual
5627 -- in the call, and complete the analysis of the call.
5629 procedure Report_Ambiguity (Op : Entity_Id);
5630 -- If a prefixed procedure call is ambiguous, indicate whether the
5631 -- call includes an implicit dereference or an implicit 'Access.
5633 procedure Transform_Object_Operation
5634 (Call_Node : out Node_Id;
5635 Node_To_Replace : out Node_Id);
5636 -- Transform Obj.Operation (X, Y,,) into Operation (Obj, X, Y ..)
5637 -- Call_Node is the resulting subprogram call, Node_To_Replace is
5638 -- either N or the parent of N, and Subprog is a reference to the
5639 -- subprogram we are trying to match.
5641 function Try_Class_Wide_Operation
5642 (Call_Node : Node_Id;
5643 Node_To_Replace : Node_Id) return Boolean;
5644 -- Traverse all ancestor types looking for a class-wide subprogram
5645 -- for which the current operation is a valid non-dispatching call.
5647 procedure Try_One_Prefix_Interpretation (T : Entity_Id);
5648 -- If prefix is overloaded, its interpretation may include different
5649 -- tagged types, and we must examine the primitive operations and
5650 -- the class-wide operations of each in order to find candidate
5651 -- interpretations for the call as a whole.
5653 function Try_Primitive_Operation
5654 (Call_Node : Node_Id;
5655 Node_To_Replace : Node_Id) return Boolean;
5656 -- Traverse the list of primitive subprograms looking for a dispatching
5657 -- operation for which the current node is a valid call .
5659 ---------------------
5660 -- Valid_Candidate --
5661 ---------------------
5663 function Valid_Candidate
5666 Subp : Entity_Id) return Entity_Id
5668 Comp_Type : Entity_Id;
5671 -- If the subprogram is a valid interpretation, record it in global
5672 -- variable Subprog, to collect all possible overloadings.
5675 if Subp /= Entity (Subprog) then
5676 Add_One_Interp (Subprog, Subp, Etype (Subp));
5680 -- If the call may be an indexed call, retrieve component type of
5681 -- resulting expression, and add possible interpretation.
5685 if Nkind (Call) = N_Function_Call
5686 and then Nkind (Parent (N)) = N_Indexed_Component
5687 and then Needs_One_Actual (Subp)
5689 if Is_Array_Type (Etype (Subp)) then
5690 Comp_Type := Component_Type (Etype (Subp));
5692 elsif Is_Access_Type (Etype (Subp))
5693 and then Is_Array_Type (Designated_Type (Etype (Subp)))
5695 Comp_Type := Component_Type (Designated_Type (Etype (Subp)));
5699 if Present (Comp_Type)
5700 and then Etype (Subprog) /= Comp_Type
5702 Add_One_Interp (Subprog, Subp, Comp_Type);
5705 if Etype (Call) /= Any_Type then
5710 end Valid_Candidate;
5712 -------------------------------
5713 -- Complete_Object_Operation --
5714 -------------------------------
5716 procedure Complete_Object_Operation
5717 (Call_Node : Node_Id;
5718 Node_To_Replace : Node_Id)
5720 Control : constant Entity_Id := First_Formal (Entity (Subprog));
5721 Formal_Type : constant Entity_Id := Etype (Control);
5722 First_Actual : Node_Id;
5725 -- Place the name of the operation, with its interpretations,
5726 -- on the rewritten call.
5728 Set_Name (Call_Node, Subprog);
5730 First_Actual := First (Parameter_Associations (Call_Node));
5732 -- For cross-reference purposes, treat the new node as being in
5733 -- the source if the original one is.
5735 Set_Comes_From_Source (Subprog, Comes_From_Source (N));
5736 Set_Comes_From_Source (Call_Node, Comes_From_Source (N));
5738 if Nkind (N) = N_Selected_Component
5739 and then not Inside_A_Generic
5741 Set_Entity (Selector_Name (N), Entity (Subprog));
5744 -- If need be, rewrite first actual as an explicit dereference
5745 -- If the call is overloaded, the rewriting can only be done
5746 -- once the primitive operation is identified.
5748 if Is_Overloaded (Subprog) then
5750 -- The prefix itself may be overloaded, and its interpretations
5751 -- must be propagated to the new actual in the call.
5753 if Is_Overloaded (Obj) then
5754 Save_Interps (Obj, First_Actual);
5757 Rewrite (First_Actual, Obj);
5759 elsif not Is_Access_Type (Formal_Type)
5760 and then Is_Access_Type (Etype (Obj))
5762 Rewrite (First_Actual,
5763 Make_Explicit_Dereference (Sloc (Obj), Obj));
5764 Analyze (First_Actual);
5766 -- If we need to introduce an explicit dereference, verify that
5767 -- the resulting actual is compatible with the mode of the formal.
5769 if Ekind (First_Formal (Entity (Subprog))) /= E_In_Parameter
5770 and then Is_Access_Constant (Etype (Obj))
5773 ("expect variable in call to&", Prefix (N), Entity (Subprog));
5776 -- Conversely, if the formal is an access parameter and the object
5777 -- is not, replace the actual with a 'Access reference. Its analysis
5778 -- will check that the object is aliased.
5780 elsif Is_Access_Type (Formal_Type)
5781 and then not Is_Access_Type (Etype (Obj))
5783 -- A special case: A.all'access is illegal if A is an access to a
5784 -- constant and the context requires an access to a variable.
5786 if not Is_Access_Constant (Formal_Type) then
5787 if (Nkind (Obj) = N_Explicit_Dereference
5788 and then Is_Access_Constant (Etype (Prefix (Obj))))
5789 or else not Is_Variable (Obj)
5792 ("actual for& must be a variable", Obj, Control);
5796 Rewrite (First_Actual,
5797 Make_Attribute_Reference (Loc,
5798 Attribute_Name => Name_Access,
5799 Prefix => Relocate_Node (Obj)));
5801 if not Is_Aliased_View (Obj) then
5803 ("object in prefixed call to& must be aliased"
5804 & " (RM-2005 4.3.1 (13))",
5805 Prefix (First_Actual), Subprog);
5808 Analyze (First_Actual);
5811 if Is_Overloaded (Obj) then
5812 Save_Interps (Obj, First_Actual);
5815 Rewrite (First_Actual, Obj);
5818 Rewrite (Node_To_Replace, Call_Node);
5820 -- Propagate the interpretations collected in subprog to the new
5821 -- function call node, to be resolved from context.
5823 if Is_Overloaded (Subprog) then
5824 Save_Interps (Subprog, Node_To_Replace);
5826 Analyze (Node_To_Replace);
5828 end Complete_Object_Operation;
5830 ----------------------
5831 -- Report_Ambiguity --
5832 ----------------------
5834 procedure Report_Ambiguity (Op : Entity_Id) is
5835 Access_Formal : constant Boolean :=
5836 Is_Access_Type (Etype (First_Formal (Op)));
5837 Access_Actual : constant Boolean :=
5838 Is_Access_Type (Etype (Prefix (N)));
5841 Error_Msg_Sloc := Sloc (Op);
5843 if Access_Formal and then not Access_Actual then
5844 if Nkind (Parent (Op)) = N_Full_Type_Declaration then
5846 ("\possible interpretation"
5847 & " (inherited, with implicit 'Access) #", N);
5850 ("\possible interpretation (with implicit 'Access) #", N);
5853 elsif not Access_Formal and then Access_Actual then
5854 if Nkind (Parent (Op)) = N_Full_Type_Declaration then
5856 ("\possible interpretation"
5857 & " ( inherited, with implicit dereference) #", N);
5860 ("\possible interpretation (with implicit dereference) #", N);
5864 if Nkind (Parent (Op)) = N_Full_Type_Declaration then
5865 Error_Msg_N ("\possible interpretation (inherited)#", N);
5867 Error_Msg_N ("\possible interpretation#", N);
5870 end Report_Ambiguity;
5872 --------------------------------
5873 -- Transform_Object_Operation --
5874 --------------------------------
5876 procedure Transform_Object_Operation
5877 (Call_Node : out Node_Id;
5878 Node_To_Replace : out Node_Id)
5880 Dummy : constant Node_Id := New_Copy (Obj);
5881 -- Placeholder used as a first parameter in the call, replaced
5882 -- eventually by the proper object.
5884 Parent_Node : constant Node_Id := Parent (N);
5890 -- Common case covering 1) Call to a procedure and 2) Call to a
5891 -- function that has some additional actuals.
5893 if Nkind_In (Parent_Node, N_Function_Call,
5894 N_Procedure_Call_Statement)
5896 -- N is a selected component node containing the name of the
5897 -- subprogram. If N is not the name of the parent node we must
5898 -- not replace the parent node by the new construct. This case
5899 -- occurs when N is a parameterless call to a subprogram that
5900 -- is an actual parameter of a call to another subprogram. For
5902 -- Some_Subprogram (..., Obj.Operation, ...)
5904 and then Name (Parent_Node) = N
5906 Node_To_Replace := Parent_Node;
5908 Actuals := Parameter_Associations (Parent_Node);
5910 if Present (Actuals) then
5911 Prepend (Dummy, Actuals);
5913 Actuals := New_List (Dummy);
5916 if Nkind (Parent_Node) = N_Procedure_Call_Statement then
5918 Make_Procedure_Call_Statement (Loc,
5919 Name => New_Copy (Subprog),
5920 Parameter_Associations => Actuals);
5924 Make_Function_Call (Loc,
5925 Name => New_Copy (Subprog),
5926 Parameter_Associations => Actuals);
5930 -- Before analysis, a function call appears as an indexed component
5931 -- if there are no named associations.
5933 elsif Nkind (Parent_Node) = N_Indexed_Component
5934 and then N = Prefix (Parent_Node)
5936 Node_To_Replace := Parent_Node;
5938 Actuals := Expressions (Parent_Node);
5940 Actual := First (Actuals);
5941 while Present (Actual) loop
5946 Prepend (Dummy, Actuals);
5949 Make_Function_Call (Loc,
5950 Name => New_Copy (Subprog),
5951 Parameter_Associations => Actuals);
5953 -- Parameterless call: Obj.F is rewritten as F (Obj)
5956 Node_To_Replace := N;
5959 Make_Function_Call (Loc,
5960 Name => New_Copy (Subprog),
5961 Parameter_Associations => New_List (Dummy));
5963 end Transform_Object_Operation;
5965 ------------------------------
5966 -- Try_Class_Wide_Operation --
5967 ------------------------------
5969 function Try_Class_Wide_Operation
5970 (Call_Node : Node_Id;
5971 Node_To_Replace : Node_Id) return Boolean
5973 Anc_Type : Entity_Id;
5974 Matching_Op : Entity_Id := Empty;
5977 procedure Traverse_Homonyms
5978 (Anc_Type : Entity_Id;
5979 Error : out Boolean);
5980 -- Traverse the homonym chain of the subprogram searching for those
5981 -- homonyms whose first formal has the Anc_Type's class-wide type,
5982 -- or an anonymous access type designating the class-wide type. If
5983 -- an ambiguity is detected, then Error is set to True.
5985 procedure Traverse_Interfaces
5986 (Anc_Type : Entity_Id;
5987 Error : out Boolean);
5988 -- Traverse the list of interfaces, if any, associated with Anc_Type
5989 -- and search for acceptable class-wide homonyms associated with each
5990 -- interface. If an ambiguity is detected, then Error is set to True.
5992 -----------------------
5993 -- Traverse_Homonyms --
5994 -----------------------
5996 procedure Traverse_Homonyms
5997 (Anc_Type : Entity_Id;
5998 Error : out Boolean)
6000 Cls_Type : Entity_Id;
6008 Cls_Type := Class_Wide_Type (Anc_Type);
6010 Hom := Current_Entity (Subprog);
6012 -- Find operation whose first parameter is of the class-wide
6013 -- type, a subtype thereof, or an anonymous access to same.
6015 while Present (Hom) loop
6016 if (Ekind (Hom) = E_Procedure
6018 Ekind (Hom) = E_Function)
6019 and then Scope (Hom) = Scope (Anc_Type)
6020 and then Present (First_Formal (Hom))
6022 (Base_Type (Etype (First_Formal (Hom))) = Cls_Type
6024 (Is_Access_Type (Etype (First_Formal (Hom)))
6026 Ekind (Etype (First_Formal (Hom))) =
6027 E_Anonymous_Access_Type
6030 (Designated_Type (Etype (First_Formal (Hom)))) =
6033 Set_Etype (Call_Node, Any_Type);
6034 Set_Is_Overloaded (Call_Node, False);
6037 if No (Matching_Op) then
6038 Hom_Ref := New_Reference_To (Hom, Sloc (Subprog));
6039 Set_Etype (Call_Node, Any_Type);
6040 Set_Parent (Call_Node, Parent (Node_To_Replace));
6042 Set_Name (Call_Node, Hom_Ref);
6047 Report => Report_Error,
6049 Skip_First => True);
6052 Valid_Candidate (Success, Call_Node, Hom);
6058 Report => Report_Error,
6060 Skip_First => True);
6062 if Present (Valid_Candidate (Success, Call_Node, Hom))
6063 and then Nkind (Call_Node) /= N_Function_Call
6065 Error_Msg_NE ("ambiguous call to&", N, Hom);
6066 Report_Ambiguity (Matching_Op);
6067 Report_Ambiguity (Hom);
6074 Hom := Homonym (Hom);
6076 end Traverse_Homonyms;
6078 -------------------------
6079 -- Traverse_Interfaces --
6080 -------------------------
6082 procedure Traverse_Interfaces
6083 (Anc_Type : Entity_Id;
6084 Error : out Boolean)
6086 Intface_List : constant List_Id :=
6087 Abstract_Interface_List (Anc_Type);
6093 if Is_Non_Empty_List (Intface_List) then
6094 Intface := First (Intface_List);
6095 while Present (Intface) loop
6097 -- Look for acceptable class-wide homonyms associated with
6100 Traverse_Homonyms (Etype (Intface), Error);
6106 -- Continue the search by looking at each of the interface's
6107 -- associated interface ancestors.
6109 Traverse_Interfaces (Etype (Intface), Error);
6118 end Traverse_Interfaces;
6120 -- Start of processing for Try_Class_Wide_Operation
6123 -- Loop through ancestor types (including interfaces), traversing
6124 -- the homonym chain of the subprogram, trying out those homonyms
6125 -- whose first formal has the class-wide type of the ancestor, or
6126 -- an anonymous access type designating the class-wide type.
6128 Anc_Type := Obj_Type;
6130 -- Look for a match among homonyms associated with the ancestor
6132 Traverse_Homonyms (Anc_Type, Error);
6138 -- Continue the search for matches among homonyms associated with
6139 -- any interfaces implemented by the ancestor.
6141 Traverse_Interfaces (Anc_Type, Error);
6147 exit when Etype (Anc_Type) = Anc_Type;
6148 Anc_Type := Etype (Anc_Type);
6151 if Present (Matching_Op) then
6152 Set_Etype (Call_Node, Etype (Matching_Op));
6155 return Present (Matching_Op);
6156 end Try_Class_Wide_Operation;
6158 -----------------------------------
6159 -- Try_One_Prefix_Interpretation --
6160 -----------------------------------
6162 procedure Try_One_Prefix_Interpretation (T : Entity_Id) is
6166 if Is_Access_Type (Obj_Type) then
6167 Obj_Type := Designated_Type (Obj_Type);
6170 if Ekind (Obj_Type) = E_Private_Subtype then
6171 Obj_Type := Base_Type (Obj_Type);
6174 if Is_Class_Wide_Type (Obj_Type) then
6175 Obj_Type := Etype (Class_Wide_Type (Obj_Type));
6178 -- The type may have be obtained through a limited_with clause,
6179 -- in which case the primitive operations are available on its
6180 -- non-limited view. If still incomplete, retrieve full view.
6182 if Ekind (Obj_Type) = E_Incomplete_Type
6183 and then From_With_Type (Obj_Type)
6185 Obj_Type := Get_Full_View (Non_Limited_View (Obj_Type));
6188 -- If the object is not tagged, or the type is still an incomplete
6189 -- type, this is not a prefixed call.
6191 if not Is_Tagged_Type (Obj_Type)
6192 or else Is_Incomplete_Type (Obj_Type)
6197 if Try_Primitive_Operation
6198 (Call_Node => New_Call_Node,
6199 Node_To_Replace => Node_To_Replace)
6201 Try_Class_Wide_Operation
6202 (Call_Node => New_Call_Node,
6203 Node_To_Replace => Node_To_Replace)
6207 end Try_One_Prefix_Interpretation;
6209 -----------------------------
6210 -- Try_Primitive_Operation --
6211 -----------------------------
6213 function Try_Primitive_Operation
6214 (Call_Node : Node_Id;
6215 Node_To_Replace : Node_Id) return Boolean
6218 Prim_Op : Entity_Id;
6219 Matching_Op : Entity_Id := Empty;
6220 Prim_Op_Ref : Node_Id := Empty;
6222 Corr_Type : Entity_Id := Empty;
6223 -- If the prefix is a synchronized type, the controlling type of
6224 -- the primitive operation is the corresponding record type, else
6225 -- this is the object type itself.
6227 Success : Boolean := False;
6229 function Collect_Generic_Type_Ops (T : Entity_Id) return Elist_Id;
6230 -- For tagged types the candidate interpretations are found in
6231 -- the list of primitive operations of the type and its ancestors.
6232 -- For formal tagged types we have to find the operations declared
6233 -- in the same scope as the type (including in the generic formal
6234 -- part) because the type itself carries no primitive operations,
6235 -- except for formal derived types that inherit the operations of
6236 -- the parent and progenitors.
6237 -- If the context is a generic subprogram body, the generic formals
6238 -- are visible by name, but are not in the entity list of the
6239 -- subprogram because that list starts with the subprogram formals.
6240 -- We retrieve the candidate operations from the generic declaration.
6242 function Valid_First_Argument_Of (Op : Entity_Id) return Boolean;
6243 -- Verify that the prefix, dereferenced if need be, is a valid
6244 -- controlling argument in a call to Op. The remaining actuals
6245 -- are checked in the subsequent call to Analyze_One_Call.
6247 ------------------------------
6248 -- Collect_Generic_Type_Ops --
6249 ------------------------------
6251 function Collect_Generic_Type_Ops (T : Entity_Id) return Elist_Id is
6252 Bas : constant Entity_Id := Base_Type (T);
6253 Candidates : constant Elist_Id := New_Elmt_List;
6257 procedure Check_Candidate;
6258 -- The operation is a candidate if its first parameter is a
6259 -- controlling operand of the desired type.
6261 -----------------------
6262 -- Check_Candidate; --
6263 -----------------------
6265 procedure Check_Candidate is
6267 Formal := First_Formal (Subp);
6270 and then Is_Controlling_Formal (Formal)
6272 (Base_Type (Etype (Formal)) = Bas
6274 (Is_Access_Type (Etype (Formal))
6275 and then Designated_Type (Etype (Formal)) = Bas))
6277 Append_Elmt (Subp, Candidates);
6279 end Check_Candidate;
6281 -- Start of processing for Collect_Generic_Type_Ops
6284 if Is_Derived_Type (T) then
6285 return Primitive_Operations (T);
6287 elsif Ekind (Scope (T)) = E_Procedure
6288 or else Ekind (Scope (T)) = E_Function
6290 -- Scan the list of generic formals to find subprograms
6291 -- that may have a first controlling formal of the type.
6298 First (Generic_Formal_Declarations
6299 (Unit_Declaration_Node (Scope (T))));
6300 while Present (Decl) loop
6301 if Nkind (Decl) in N_Formal_Subprogram_Declaration then
6302 Subp := Defining_Entity (Decl);
6313 -- Scan the list of entities declared in the same scope as
6314 -- the type. In general this will be an open scope, given that
6315 -- the call we are analyzing can only appear within a generic
6316 -- declaration or body (either the one that declares T, or a
6319 Subp := First_Entity (Scope (T));
6320 while Present (Subp) loop
6321 if Is_Overloadable (Subp) then
6330 end Collect_Generic_Type_Ops;
6332 -----------------------------
6333 -- Valid_First_Argument_Of --
6334 -----------------------------
6336 function Valid_First_Argument_Of (Op : Entity_Id) return Boolean is
6337 Typ : constant Entity_Id := Etype (First_Formal (Op));
6340 -- Simple case. Object may be a subtype of the tagged type or
6341 -- may be the corresponding record of a synchronized type.
6343 return Obj_Type = Typ
6344 or else Base_Type (Obj_Type) = Typ
6345 or else Corr_Type = Typ
6347 -- Prefix can be dereferenced
6350 (Is_Access_Type (Corr_Type)
6351 and then Designated_Type (Corr_Type) = Typ)
6353 -- Formal is an access parameter, for which the object
6354 -- can provide an access.
6357 (Ekind (Typ) = E_Anonymous_Access_Type
6358 and then Designated_Type (Typ) = Base_Type (Corr_Type));
6359 end Valid_First_Argument_Of;
6361 -- Start of processing for Try_Primitive_Operation
6364 -- Look for subprograms in the list of primitive operations. The name
6365 -- must be identical, and the kind of call indicates the expected
6366 -- kind of operation (function or procedure). If the type is a
6367 -- (tagged) synchronized type, the primitive ops are attached to the
6368 -- corresponding record (base) type.
6370 if Is_Concurrent_Type (Obj_Type) then
6371 Corr_Type := Base_Type (Corresponding_Record_Type (Obj_Type));
6372 Elmt := First_Elmt (Primitive_Operations (Corr_Type));
6374 elsif not Is_Generic_Type (Obj_Type) then
6375 Corr_Type := Obj_Type;
6376 Elmt := First_Elmt (Primitive_Operations (Obj_Type));
6379 Corr_Type := Obj_Type;
6380 Elmt := First_Elmt (Collect_Generic_Type_Ops (Obj_Type));
6383 while Present (Elmt) loop
6384 Prim_Op := Node (Elmt);
6386 if Chars (Prim_Op) = Chars (Subprog)
6387 and then Present (First_Formal (Prim_Op))
6388 and then Valid_First_Argument_Of (Prim_Op)
6390 (Nkind (Call_Node) = N_Function_Call)
6391 = (Ekind (Prim_Op) = E_Function)
6393 -- Ada 2005 (AI-251): If this primitive operation corresponds
6394 -- with an immediate ancestor interface there is no need to add
6395 -- it to the list of interpretations; the corresponding aliased
6396 -- primitive is also in this list of primitive operations and
6397 -- will be used instead.
6399 if (Present (Abstract_Interface_Alias (Prim_Op))
6400 and then Is_Ancestor (Find_Dispatching_Type
6401 (Alias (Prim_Op)), Corr_Type))
6404 -- Do not consider hidden primitives unless the type is in an
6405 -- open scope or we are within an instance, where visibility
6406 -- is known to be correct.
6408 (Is_Hidden (Prim_Op)
6409 and then not Is_Immediately_Visible (Obj_Type)
6410 and then not In_Instance)
6415 Set_Etype (Call_Node, Any_Type);
6416 Set_Is_Overloaded (Call_Node, False);
6418 if No (Matching_Op) then
6419 Prim_Op_Ref := New_Reference_To (Prim_Op, Sloc (Subprog));
6420 Candidate := Prim_Op;
6422 Set_Parent (Call_Node, Parent (Node_To_Replace));
6424 Set_Name (Call_Node, Prim_Op_Ref);
6430 Report => Report_Error,
6432 Skip_First => True);
6434 Matching_Op := Valid_Candidate (Success, Call_Node, Prim_Op);
6436 -- More than one interpretation, collect for subsequent
6437 -- disambiguation. If this is a procedure call and there
6438 -- is another match, report ambiguity now.
6444 Report => Report_Error,
6446 Skip_First => True);
6448 if Present (Valid_Candidate (Success, Call_Node, Prim_Op))
6449 and then Nkind (Call_Node) /= N_Function_Call
6451 Error_Msg_NE ("ambiguous call to&", N, Prim_Op);
6452 Report_Ambiguity (Matching_Op);
6453 Report_Ambiguity (Prim_Op);
6463 if Present (Matching_Op) then
6464 Set_Etype (Call_Node, Etype (Matching_Op));
6467 return Present (Matching_Op);
6468 end Try_Primitive_Operation;
6470 -- Start of processing for Try_Object_Operation
6473 Analyze_Expression (Obj);
6475 -- Analyze the actuals if node is known to be a subprogram call
6477 if Is_Subprg_Call and then N = Name (Parent (N)) then
6478 Actual := First (Parameter_Associations (Parent (N)));
6479 while Present (Actual) loop
6480 Analyze_Expression (Actual);
6485 -- Build a subprogram call node, using a copy of Obj as its first
6486 -- actual. This is a placeholder, to be replaced by an explicit
6487 -- dereference when needed.
6489 Transform_Object_Operation
6490 (Call_Node => New_Call_Node,
6491 Node_To_Replace => Node_To_Replace);
6493 Set_Etype (New_Call_Node, Any_Type);
6494 Set_Etype (Subprog, Any_Type);
6495 Set_Parent (New_Call_Node, Parent (Node_To_Replace));
6497 if not Is_Overloaded (Obj) then
6498 Try_One_Prefix_Interpretation (Obj_Type);
6505 Get_First_Interp (Obj, I, It);
6506 while Present (It.Nam) loop
6507 Try_One_Prefix_Interpretation (It.Typ);
6508 Get_Next_Interp (I, It);
6513 if Etype (New_Call_Node) /= Any_Type then
6514 Complete_Object_Operation
6515 (Call_Node => New_Call_Node,
6516 Node_To_Replace => Node_To_Replace);
6519 elsif Present (Candidate) then
6521 -- The argument list is not type correct. Re-analyze with error
6522 -- reporting enabled, and use one of the possible candidates.
6523 -- In All_Errors_Mode, re-analyze all failed interpretations.
6525 if All_Errors_Mode then
6526 Report_Error := True;
6527 if Try_Primitive_Operation
6528 (Call_Node => New_Call_Node,
6529 Node_To_Replace => Node_To_Replace)
6532 Try_Class_Wide_Operation
6533 (Call_Node => New_Call_Node,
6534 Node_To_Replace => Node_To_Replace)
6541 (N => New_Call_Node,
6545 Skip_First => True);
6548 -- No need for further errors
6553 -- There was no candidate operation, so report it as an error
6554 -- in the caller: Analyze_Selected_Component.
6558 end Try_Object_Operation;
6564 procedure wpo (T : Entity_Id) is
6569 if not Is_Tagged_Type (T) then
6573 E := First_Elmt (Primitive_Operations (Base_Type (T)));
6574 while Present (E) loop
6576 Write_Int (Int (Op));
6577 Write_Str (" === ");
6578 Write_Name (Chars (Op));
6580 Write_Name (Chars (Scope (Op)));