1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2011, Free Software Foundation, Inc. --
11 -- GNAT is free software; you can redistribute it and/or modify it under --
12 -- terms of the GNU General Public License as published by the Free Soft- --
13 -- ware Foundation; either version 3, or (at your option) any later ver- --
14 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
15 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
16 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
17 -- for more details. You should have received a copy of the GNU General --
18 -- Public License distributed with GNAT; see file COPYING3. If not, go to --
19 -- http://www.gnu.org/licenses for a complete copy of the license. --
21 -- GNAT was originally developed by the GNAT team at New York University. --
22 -- Extensive contributions were provided by Ada Core Technologies Inc. --
24 ------------------------------------------------------------------------------
26 with Aspects; use Aspects;
27 with Atree; use Atree;
28 with Debug; use Debug;
29 with Einfo; use Einfo;
30 with Elists; use Elists;
31 with Errout; use Errout;
32 with Exp_Util; use Exp_Util;
33 with Fname; use Fname;
34 with Itypes; use Itypes;
36 with Lib.Xref; use Lib.Xref;
37 with Namet; use Namet;
38 with Namet.Sp; use Namet.Sp;
39 with Nlists; use Nlists;
40 with Nmake; use Nmake;
42 with Output; use Output;
43 with Restrict; use Restrict;
44 with Rident; use Rident;
46 with Sem_Aux; use Sem_Aux;
47 with Sem_Case; use Sem_Case;
48 with Sem_Cat; use Sem_Cat;
49 with Sem_Ch3; use Sem_Ch3;
50 with Sem_Ch5; use Sem_Ch5;
51 with Sem_Ch6; use Sem_Ch6;
52 with Sem_Ch8; use Sem_Ch8;
53 with Sem_Disp; use Sem_Disp;
54 with Sem_Dist; use Sem_Dist;
55 with Sem_Eval; use Sem_Eval;
56 with Sem_Res; use Sem_Res;
57 with Sem_Type; use Sem_Type;
58 with Sem_Util; use Sem_Util;
59 with Sem_Warn; use Sem_Warn;
60 with Stand; use Stand;
61 with Sinfo; use Sinfo;
62 with Snames; use Snames;
63 with Tbuild; use Tbuild;
65 package body Sem_Ch4 is
67 -----------------------
68 -- Local Subprograms --
69 -----------------------
71 procedure Analyze_Concatenation_Rest (N : Node_Id);
72 -- Does the "rest" of the work of Analyze_Concatenation, after the left
73 -- operand has been analyzed. See Analyze_Concatenation for details.
75 procedure Analyze_Expression (N : Node_Id);
76 -- For expressions that are not names, this is just a call to analyze.
77 -- If the expression is a name, it may be a call to a parameterless
78 -- function, and if so must be converted into an explicit call node
79 -- and analyzed as such. This deproceduring must be done during the first
80 -- pass of overload resolution, because otherwise a procedure call with
81 -- overloaded actuals may fail to resolve.
83 procedure Analyze_Operator_Call (N : Node_Id; Op_Id : Entity_Id);
84 -- Analyze a call of the form "+"(x, y), etc. The prefix of the call
85 -- is an operator name or an expanded name whose selector is an operator
86 -- name, and one possible interpretation is as a predefined operator.
88 procedure Analyze_Overloaded_Selected_Component (N : Node_Id);
89 -- If the prefix of a selected_component is overloaded, the proper
90 -- interpretation that yields a record type with the proper selector
91 -- name must be selected.
93 procedure Analyze_User_Defined_Binary_Op (N : Node_Id; Op_Id : Entity_Id);
94 -- Procedure to analyze a user defined binary operator, which is resolved
95 -- like a function, but instead of a list of actuals it is presented
96 -- with the left and right operands of an operator node.
98 procedure Analyze_User_Defined_Unary_Op (N : Node_Id; Op_Id : Entity_Id);
99 -- Procedure to analyze a user defined unary operator, which is resolved
100 -- like a function, but instead of a list of actuals, it is presented with
101 -- the operand of the operator node.
103 procedure Ambiguous_Operands (N : Node_Id);
104 -- For equality, membership, and comparison operators with overloaded
105 -- arguments, list possible interpretations.
107 procedure Analyze_One_Call
111 Success : out Boolean;
112 Skip_First : Boolean := False);
113 -- Check one interpretation of an overloaded subprogram name for
114 -- compatibility with the types of the actuals in a call. If there is a
115 -- single interpretation which does not match, post error if Report is
118 -- Nam is the entity that provides the formals against which the actuals
119 -- are checked. Nam is either the name of a subprogram, or the internal
120 -- subprogram type constructed for an access_to_subprogram. If the actuals
121 -- are compatible with Nam, then Nam is added to the list of candidate
122 -- interpretations for N, and Success is set to True.
124 -- The flag Skip_First is used when analyzing a call that was rewritten
125 -- from object notation. In this case the first actual may have to receive
126 -- an explicit dereference, depending on the first formal of the operation
127 -- being called. The caller will have verified that the object is legal
128 -- for the call. If the remaining parameters match, the first parameter
129 -- will rewritten as a dereference if needed, prior to completing analysis.
131 procedure Check_Misspelled_Selector
134 -- Give possible misspelling diagnostic if Sel is likely to be a mis-
135 -- spelling of one of the selectors of the Prefix. This is called by
136 -- Analyze_Selected_Component after producing an invalid selector error
139 function Defined_In_Scope (T : Entity_Id; S : Entity_Id) return Boolean;
140 -- Verify that type T is declared in scope S. Used to find interpretations
141 -- for operators given by expanded names. This is abstracted as a separate
142 -- function to handle extensions to System, where S is System, but T is
143 -- declared in the extension.
145 procedure Find_Arithmetic_Types
149 -- L and R are the operands of an arithmetic operator. Find
150 -- consistent pairs of interpretations for L and R that have a
151 -- numeric type consistent with the semantics of the operator.
153 procedure Find_Comparison_Types
157 -- L and R are operands of a comparison operator. Find consistent
158 -- pairs of interpretations for L and R.
160 procedure Find_Concatenation_Types
164 -- For the four varieties of concatenation
166 procedure Find_Equality_Types
170 -- Ditto for equality operators
172 procedure Find_Boolean_Types
176 -- Ditto for binary logical operations
178 procedure Find_Negation_Types
182 -- Find consistent interpretation for operand of negation operator
184 procedure Find_Non_Universal_Interpretations
189 -- For equality and comparison operators, the result is always boolean,
190 -- and the legality of the operation is determined from the visibility
191 -- of the operand types. If one of the operands has a universal interpre-
192 -- tation, the legality check uses some compatible non-universal
193 -- interpretation of the other operand. N can be an operator node, or
194 -- a function call whose name is an operator designator.
196 function Find_Primitive_Operation (N : Node_Id) return Boolean;
197 -- Find candidate interpretations for the name Obj.Proc when it appears
198 -- in a subprogram renaming declaration.
200 procedure Find_Unary_Types
204 -- Unary arithmetic types: plus, minus, abs
206 procedure Check_Arithmetic_Pair
210 -- Subsidiary procedure to Find_Arithmetic_Types. T1 and T2 are valid
211 -- types for left and right operand. Determine whether they constitute
212 -- a valid pair for the given operator, and record the corresponding
213 -- interpretation of the operator node. The node N may be an operator
214 -- node (the usual case) or a function call whose prefix is an operator
215 -- designator. In both cases Op_Id is the operator name itself.
217 procedure Diagnose_Call (N : Node_Id; Nam : Node_Id);
218 -- Give detailed information on overloaded call where none of the
219 -- interpretations match. N is the call node, Nam the designator for
220 -- the overloaded entity being called.
222 function Junk_Operand (N : Node_Id) return Boolean;
223 -- Test for an operand that is an inappropriate entity (e.g. a package
224 -- name or a label). If so, issue an error message and return True. If
225 -- the operand is not an inappropriate entity kind, return False.
227 procedure Operator_Check (N : Node_Id);
228 -- Verify that an operator has received some valid interpretation. If none
229 -- was found, determine whether a use clause would make the operation
230 -- legal. The variable Candidate_Type (defined in Sem_Type) is set for
231 -- every type compatible with the operator, even if the operator for the
232 -- type is not directly visible. The routine uses this type to emit a more
233 -- informative message.
235 function Process_Implicit_Dereference_Prefix
237 P : Node_Id) return Entity_Id;
238 -- Called when P is the prefix of an implicit dereference, denoting an
239 -- object E. The function returns the designated type of the prefix, taking
240 -- into account that the designated type of an anonymous access type may be
241 -- a limited view, when the non-limited view is visible.
242 -- If in semantics only mode (-gnatc or generic), the function also records
243 -- that the prefix is a reference to E, if any. Normally, such a reference
244 -- is generated only when the implicit dereference is expanded into an
245 -- explicit one, but for consistency we must generate the reference when
246 -- expansion is disabled as well.
248 procedure Remove_Abstract_Operations (N : Node_Id);
249 -- Ada 2005: implementation of AI-310. An abstract non-dispatching
250 -- operation is not a candidate interpretation.
252 function Try_Container_Indexing
255 Expr : Node_Id) return Boolean;
256 -- AI05-0139: Generalized indexing to support iterators over containers
258 function Try_Indexed_Call
262 Skip_First : Boolean) return Boolean;
263 -- If a function has defaults for all its actuals, a call to it may in fact
264 -- be an indexing on the result of the call. Try_Indexed_Call attempts the
265 -- interpretation as an indexing, prior to analysis as a call. If both are
266 -- possible, the node is overloaded with both interpretations (same symbol
267 -- but two different types). If the call is written in prefix form, the
268 -- prefix becomes the first parameter in the call, and only the remaining
269 -- actuals must be checked for the presence of defaults.
271 function Try_Indirect_Call
274 Typ : Entity_Id) return Boolean;
275 -- Similarly, a function F that needs no actuals can return an access to a
276 -- subprogram, and the call F (X) interpreted as F.all (X). In this case
277 -- the call may be overloaded with both interpretations.
279 function Try_Object_Operation
281 CW_Test_Only : Boolean := False) return Boolean;
282 -- Ada 2005 (AI-252): Support the object.operation notation. If node N
283 -- is a call in this notation, it is transformed into a normal subprogram
284 -- call where the prefix is a parameter, and True is returned. If node
285 -- N is not of this form, it is unchanged, and False is returned. if
286 -- CW_Test_Only is true then N is an N_Selected_Component node which
287 -- is part of a call to an entry or procedure of a tagged concurrent
288 -- type and this routine is invoked to search for class-wide subprograms
289 -- conflicting with the target entity.
291 procedure wpo (T : Entity_Id);
292 pragma Warnings (Off, wpo);
293 -- Used for debugging: obtain list of primitive operations even if
294 -- type is not frozen and dispatch table is not built yet.
296 ------------------------
297 -- Ambiguous_Operands --
298 ------------------------
300 procedure Ambiguous_Operands (N : Node_Id) is
301 procedure List_Operand_Interps (Opnd : Node_Id);
303 --------------------------
304 -- List_Operand_Interps --
305 --------------------------
307 procedure List_Operand_Interps (Opnd : Node_Id) is
312 if Is_Overloaded (Opnd) then
313 if Nkind (Opnd) in N_Op then
315 elsif Nkind (Opnd) = N_Function_Call then
317 elsif Ada_Version >= Ada_2012 then
323 Get_First_Interp (Opnd, I, It);
324 while Present (It.Nam) loop
325 if Has_Implicit_Dereference (It.Typ) then
327 ("can be interpreted as implicit dereference", Opnd);
331 Get_Next_Interp (I, It);
342 if Opnd = Left_Opnd (N) then
343 Error_Msg_N ("\left operand has the following interpretations", N);
346 ("\right operand has the following interpretations", N);
350 List_Interps (Nam, Err);
351 end List_Operand_Interps;
353 -- Start of processing for Ambiguous_Operands
356 if Nkind (N) in N_Membership_Test then
357 Error_Msg_N ("ambiguous operands for membership", N);
359 elsif Nkind_In (N, N_Op_Eq, N_Op_Ne) then
360 Error_Msg_N ("ambiguous operands for equality", N);
363 Error_Msg_N ("ambiguous operands for comparison", N);
366 if All_Errors_Mode then
367 List_Operand_Interps (Left_Opnd (N));
368 List_Operand_Interps (Right_Opnd (N));
370 Error_Msg_N ("\use -gnatf switch for details", N);
372 end Ambiguous_Operands;
374 -----------------------
375 -- Analyze_Aggregate --
376 -----------------------
378 -- Most of the analysis of Aggregates requires that the type be known,
379 -- and is therefore put off until resolution.
381 procedure Analyze_Aggregate (N : Node_Id) is
383 if No (Etype (N)) then
384 Set_Etype (N, Any_Composite);
386 end Analyze_Aggregate;
388 -----------------------
389 -- Analyze_Allocator --
390 -----------------------
392 procedure Analyze_Allocator (N : Node_Id) is
393 Loc : constant Source_Ptr := Sloc (N);
394 Sav_Errs : constant Nat := Serious_Errors_Detected;
395 E : Node_Id := Expression (N);
396 Acc_Type : Entity_Id;
402 Check_SPARK_Restriction ("allocator is not allowed", N);
404 -- Deal with allocator restrictions
406 -- In accordance with H.4(7), the No_Allocators restriction only applies
407 -- to user-written allocators. The same consideration applies to the
408 -- No_Allocators_Before_Elaboration restriction.
410 if Comes_From_Source (N) then
411 Check_Restriction (No_Allocators, N);
413 -- Processing for No_Allocators_After_Elaboration, loop to look at
414 -- enclosing context, checking task case and main subprogram case.
418 while Present (P) loop
420 -- In both cases we need a handled sequence of statements, where
421 -- the occurrence of the allocator is within the statements.
423 if Nkind (P) = N_Handled_Sequence_Of_Statements
424 and then Is_List_Member (C)
425 and then List_Containing (C) = Statements (P)
427 -- Check for allocator within task body, this is a definite
428 -- violation of No_Allocators_After_Elaboration we can detect.
430 if Nkind (Original_Node (Parent (P))) = N_Task_Body then
431 Check_Restriction (No_Allocators_After_Elaboration, N);
435 -- The other case is appearance in a subprogram body. This may
436 -- be a violation if this is a library level subprogram, and it
437 -- turns out to be used as the main program, but only the
438 -- binder knows that, so just record the occurrence.
440 if Nkind (Original_Node (Parent (P))) = N_Subprogram_Body
441 and then Nkind (Parent (Parent (P))) = N_Compilation_Unit
443 Set_Has_Allocator (Current_Sem_Unit);
452 -- Ada 2012 (AI05-0111-3): Analyze the subpool_specification, if
453 -- any. The expected type for the name is any type. A non-overloading
454 -- rule then requires it to be of a type descended from
455 -- System.Storage_Pools.Subpools.Subpool_Handle.
457 -- This isn't exactly what the AI says, but it seems to be the right
458 -- rule. The AI should be fixed.???
461 Subpool : constant Node_Id := Subpool_Handle_Name (N);
464 if Present (Subpool) then
467 if Is_Overloaded (Subpool) then
468 Error_Msg_N ("ambiguous subpool handle", Subpool);
471 -- Check that Etype (Subpool) is descended from Subpool_Handle
477 -- Analyze the qualified expression or subtype indication
479 if Nkind (E) = N_Qualified_Expression then
480 Acc_Type := Create_Itype (E_Allocator_Type, N);
481 Set_Etype (Acc_Type, Acc_Type);
482 Find_Type (Subtype_Mark (E));
484 -- Analyze the qualified expression, and apply the name resolution
485 -- rule given in 4.7(3).
488 Type_Id := Etype (E);
489 Set_Directly_Designated_Type (Acc_Type, Type_Id);
491 Resolve (Expression (E), Type_Id);
493 -- Allocators generated by the build-in-place expansion mechanism
494 -- are explicitly marked as coming from source but do not need to be
495 -- checked for limited initialization. To exclude this case, ensure
496 -- that the parent of the allocator is a source node.
498 if Is_Limited_Type (Type_Id)
499 and then Comes_From_Source (N)
500 and then Comes_From_Source (Parent (N))
501 and then not In_Instance_Body
503 if not OK_For_Limited_Init (Type_Id, Expression (E)) then
504 Error_Msg_N ("initialization not allowed for limited types", N);
505 Explain_Limited_Type (Type_Id, N);
509 -- A qualified expression requires an exact match of the type,
510 -- class-wide matching is not allowed.
512 -- if Is_Class_Wide_Type (Type_Id)
513 -- and then Base_Type
514 -- (Etype (Expression (E))) /= Base_Type (Type_Id)
516 -- Wrong_Type (Expression (E), Type_Id);
519 Check_Non_Static_Context (Expression (E));
521 -- We don't analyze the qualified expression itself because it's
522 -- part of the allocator
524 Set_Etype (E, Type_Id);
526 -- Case where allocator has a subtype indication
531 Base_Typ : Entity_Id;
534 -- If the allocator includes a N_Subtype_Indication then a
535 -- constraint is present, otherwise the node is a subtype mark.
536 -- Introduce an explicit subtype declaration into the tree
537 -- defining some anonymous subtype and rewrite the allocator to
538 -- use this subtype rather than the subtype indication.
540 -- It is important to introduce the explicit subtype declaration
541 -- so that the bounds of the subtype indication are attached to
542 -- the tree in case the allocator is inside a generic unit.
544 if Nkind (E) = N_Subtype_Indication then
546 -- A constraint is only allowed for a composite type in Ada
547 -- 95. In Ada 83, a constraint is also allowed for an
548 -- access-to-composite type, but the constraint is ignored.
550 Find_Type (Subtype_Mark (E));
551 Base_Typ := Entity (Subtype_Mark (E));
553 if Is_Elementary_Type (Base_Typ) then
554 if not (Ada_Version = Ada_83
555 and then Is_Access_Type (Base_Typ))
557 Error_Msg_N ("constraint not allowed here", E);
559 if Nkind (Constraint (E)) =
560 N_Index_Or_Discriminant_Constraint
562 Error_Msg_N -- CODEFIX
563 ("\if qualified expression was meant, " &
564 "use apostrophe", Constraint (E));
568 -- Get rid of the bogus constraint:
570 Rewrite (E, New_Copy_Tree (Subtype_Mark (E)));
571 Analyze_Allocator (N);
574 -- Ada 2005, AI-363: if the designated type has a constrained
575 -- partial view, it cannot receive a discriminant constraint,
576 -- and the allocated object is unconstrained.
578 elsif Ada_Version >= Ada_2005
579 and then Has_Constrained_Partial_View (Base_Typ)
582 ("constraint no allowed when type " &
583 "has a constrained partial view", Constraint (E));
586 if Expander_Active then
587 Def_Id := Make_Temporary (Loc, 'S');
590 Make_Subtype_Declaration (Loc,
591 Defining_Identifier => Def_Id,
592 Subtype_Indication => Relocate_Node (E)));
594 if Sav_Errs /= Serious_Errors_Detected
595 and then Nkind (Constraint (E)) =
596 N_Index_Or_Discriminant_Constraint
598 Error_Msg_N -- CODEFIX
599 ("if qualified expression was meant, " &
600 "use apostrophe!", Constraint (E));
603 E := New_Occurrence_Of (Def_Id, Loc);
604 Rewrite (Expression (N), E);
608 Type_Id := Process_Subtype (E, N);
609 Acc_Type := Create_Itype (E_Allocator_Type, N);
610 Set_Etype (Acc_Type, Acc_Type);
611 Set_Directly_Designated_Type (Acc_Type, Type_Id);
612 Check_Fully_Declared (Type_Id, N);
614 -- Ada 2005 (AI-231): If the designated type is itself an access
615 -- type that excludes null, its default initialization will
616 -- be a null object, and we can insert an unconditional raise
617 -- before the allocator.
619 -- Ada 2012 (AI-104): A not null indication here is altogether
622 if Can_Never_Be_Null (Type_Id) then
624 Not_Null_Check : constant Node_Id :=
625 Make_Raise_Constraint_Error (Sloc (E),
626 Reason => CE_Null_Not_Allowed);
629 if Ada_Version >= Ada_2012 then
631 ("an uninitialized allocator cannot have"
632 & " a null exclusion", N);
634 elsif Expander_Active then
635 Insert_Action (N, Not_Null_Check);
636 Analyze (Not_Null_Check);
639 Error_Msg_N ("null value not allowed here?", E);
644 -- Check restriction against dynamically allocated protected
645 -- objects. Note that when limited aggregates are supported,
646 -- a similar test should be applied to an allocator with a
647 -- qualified expression ???
649 if Is_Protected_Type (Type_Id) then
650 Check_Restriction (No_Protected_Type_Allocators, N);
653 -- Check for missing initialization. Skip this check if we already
654 -- had errors on analyzing the allocator, since in that case these
655 -- are probably cascaded errors.
657 if Is_Indefinite_Subtype (Type_Id)
658 and then Serious_Errors_Detected = Sav_Errs
660 if Is_Class_Wide_Type (Type_Id) then
662 ("initialization required in class-wide allocation", N);
664 if Ada_Version < Ada_2005
665 and then Is_Limited_Type (Type_Id)
667 Error_Msg_N ("unconstrained allocation not allowed", N);
669 if Is_Array_Type (Type_Id) then
671 ("\constraint with array bounds required", N);
673 elsif Has_Unknown_Discriminants (Type_Id) then
676 else pragma Assert (Has_Discriminants (Type_Id));
678 ("\constraint with discriminant values required", N);
681 -- Limited Ada 2005 and general non-limited case
685 ("uninitialized unconstrained allocation not allowed",
688 if Is_Array_Type (Type_Id) then
690 ("\qualified expression or constraint with " &
691 "array bounds required", N);
693 elsif Has_Unknown_Discriminants (Type_Id) then
694 Error_Msg_N ("\qualified expression required", N);
696 else pragma Assert (Has_Discriminants (Type_Id));
698 ("\qualified expression or constraint with " &
699 "discriminant values required", N);
707 if Is_Abstract_Type (Type_Id) then
708 Error_Msg_N ("cannot allocate abstract object", E);
711 if Has_Task (Designated_Type (Acc_Type)) then
712 Check_Restriction (No_Tasking, N);
713 Check_Restriction (Max_Tasks, N);
714 Check_Restriction (No_Task_Allocators, N);
717 -- AI05-0013-1: No_Nested_Finalization forbids allocators if the access
718 -- type is nested, and the designated type needs finalization. The rule
719 -- is conservative in that class-wide types need finalization.
721 if Needs_Finalization (Designated_Type (Acc_Type))
722 and then not Is_Library_Level_Entity (Acc_Type)
724 Check_Restriction (No_Nested_Finalization, N);
727 -- Check that an allocator of a nested access type doesn't create a
728 -- protected object when restriction No_Local_Protected_Objects applies.
729 -- We don't have an equivalent to Has_Task for protected types, so only
730 -- cases where the designated type itself is a protected type are
731 -- currently checked. ???
733 if Is_Protected_Type (Designated_Type (Acc_Type))
734 and then not Is_Library_Level_Entity (Acc_Type)
736 Check_Restriction (No_Local_Protected_Objects, N);
739 -- If the No_Streams restriction is set, check that the type of the
740 -- object is not, and does not contain, any subtype derived from
741 -- Ada.Streams.Root_Stream_Type. Note that we guard the call to
742 -- Has_Stream just for efficiency reasons. There is no point in
743 -- spending time on a Has_Stream check if the restriction is not set.
745 if Restriction_Check_Required (No_Streams) then
746 if Has_Stream (Designated_Type (Acc_Type)) then
747 Check_Restriction (No_Streams, N);
751 Set_Etype (N, Acc_Type);
753 if not Is_Library_Level_Entity (Acc_Type) then
754 Check_Restriction (No_Local_Allocators, N);
757 if Serious_Errors_Detected > Sav_Errs then
758 Set_Error_Posted (N);
759 Set_Etype (N, Any_Type);
761 end Analyze_Allocator;
763 ---------------------------
764 -- Analyze_Arithmetic_Op --
765 ---------------------------
767 procedure Analyze_Arithmetic_Op (N : Node_Id) is
768 L : constant Node_Id := Left_Opnd (N);
769 R : constant Node_Id := Right_Opnd (N);
773 Candidate_Type := Empty;
774 Analyze_Expression (L);
775 Analyze_Expression (R);
777 -- If the entity is already set, the node is the instantiation of a
778 -- generic node with a non-local reference, or was manufactured by a
779 -- call to Make_Op_xxx. In either case the entity is known to be valid,
780 -- and we do not need to collect interpretations, instead we just get
781 -- the single possible interpretation.
785 if Present (Op_Id) then
786 if Ekind (Op_Id) = E_Operator then
788 if Nkind_In (N, N_Op_Divide, N_Op_Mod, N_Op_Multiply, N_Op_Rem)
789 and then Treat_Fixed_As_Integer (N)
793 Set_Etype (N, Any_Type);
794 Find_Arithmetic_Types (L, R, Op_Id, N);
798 Set_Etype (N, Any_Type);
799 Add_One_Interp (N, Op_Id, Etype (Op_Id));
802 -- Entity is not already set, so we do need to collect interpretations
805 Op_Id := Get_Name_Entity_Id (Chars (N));
806 Set_Etype (N, Any_Type);
808 while Present (Op_Id) loop
809 if Ekind (Op_Id) = E_Operator
810 and then Present (Next_Entity (First_Entity (Op_Id)))
812 Find_Arithmetic_Types (L, R, Op_Id, N);
814 -- The following may seem superfluous, because an operator cannot
815 -- be generic, but this ignores the cleverness of the author of
818 elsif Is_Overloadable (Op_Id) then
819 Analyze_User_Defined_Binary_Op (N, Op_Id);
822 Op_Id := Homonym (Op_Id);
827 end Analyze_Arithmetic_Op;
833 -- Function, procedure, and entry calls are checked here. The Name in
834 -- the call may be overloaded. The actuals have been analyzed and may
835 -- themselves be overloaded. On exit from this procedure, the node N
836 -- may have zero, one or more interpretations. In the first case an
837 -- error message is produced. In the last case, the node is flagged
838 -- as overloaded and the interpretations are collected in All_Interp.
840 -- If the name is an Access_To_Subprogram, it cannot be overloaded, but
841 -- the type-checking is similar to that of other calls.
843 procedure Analyze_Call (N : Node_Id) is
844 Actuals : constant List_Id := Parameter_Associations (N);
849 Success : Boolean := False;
851 Deref : Boolean := False;
852 -- Flag indicates whether an interpretation of the prefix is a
853 -- parameterless call that returns an access_to_subprogram.
855 procedure Check_Mixed_Parameter_And_Named_Associations;
856 -- Check that parameter and named associations are not mixed. This is
857 -- a restriction in SPARK mode.
859 function Name_Denotes_Function return Boolean;
860 -- If the type of the name is an access to subprogram, this may be the
861 -- type of a name, or the return type of the function being called. If
862 -- the name is not an entity then it can denote a protected function.
863 -- Until we distinguish Etype from Return_Type, we must use this routine
864 -- to resolve the meaning of the name in the call.
866 procedure No_Interpretation;
867 -- Output error message when no valid interpretation exists
869 --------------------------------------------------
870 -- Check_Mixed_Parameter_And_Named_Associations --
871 --------------------------------------------------
873 procedure Check_Mixed_Parameter_And_Named_Associations is
875 Named_Seen : Boolean;
880 Actual := First (Actuals);
881 while Present (Actual) loop
882 case Nkind (Actual) is
883 when N_Parameter_Association =>
885 Check_SPARK_Restriction
886 ("named association cannot follow positional one",
896 end Check_Mixed_Parameter_And_Named_Associations;
898 ---------------------------
899 -- Name_Denotes_Function --
900 ---------------------------
902 function Name_Denotes_Function return Boolean is
904 if Is_Entity_Name (Nam) then
905 return Ekind (Entity (Nam)) = E_Function;
907 elsif Nkind (Nam) = N_Selected_Component then
908 return Ekind (Entity (Selector_Name (Nam))) = E_Function;
913 end Name_Denotes_Function;
915 -----------------------
916 -- No_Interpretation --
917 -----------------------
919 procedure No_Interpretation is
920 L : constant Boolean := Is_List_Member (N);
921 K : constant Node_Kind := Nkind (Parent (N));
924 -- If the node is in a list whose parent is not an expression then it
925 -- must be an attempted procedure call.
927 if L and then K not in N_Subexpr then
928 if Ekind (Entity (Nam)) = E_Generic_Procedure then
930 ("must instantiate generic procedure& before call",
934 ("procedure or entry name expected", Nam);
937 -- Check for tasking cases where only an entry call will do
940 and then Nkind_In (K, N_Entry_Call_Alternative,
941 N_Triggering_Alternative)
943 Error_Msg_N ("entry name expected", Nam);
945 -- Otherwise give general error message
948 Error_Msg_N ("invalid prefix in call", Nam);
950 end No_Interpretation;
952 -- Start of processing for Analyze_Call
955 if Restriction_Check_Required (SPARK) then
956 Check_Mixed_Parameter_And_Named_Associations;
959 -- Initialize the type of the result of the call to the error type,
960 -- which will be reset if the type is successfully resolved.
962 Set_Etype (N, Any_Type);
966 if not Is_Overloaded (Nam) then
968 -- Only one interpretation to check
970 if Ekind (Etype (Nam)) = E_Subprogram_Type then
971 Nam_Ent := Etype (Nam);
973 -- If the prefix is an access_to_subprogram, this may be an indirect
974 -- call. This is the case if the name in the call is not an entity
975 -- name, or if it is a function name in the context of a procedure
976 -- call. In this latter case, we have a call to a parameterless
977 -- function that returns a pointer_to_procedure which is the entity
978 -- being called. Finally, F (X) may be a call to a parameterless
979 -- function that returns a pointer to a function with parameters.
981 elsif Is_Access_Type (Etype (Nam))
982 and then Ekind (Designated_Type (Etype (Nam))) = E_Subprogram_Type
984 (not Name_Denotes_Function
985 or else Nkind (N) = N_Procedure_Call_Statement
987 (Nkind (Parent (N)) /= N_Explicit_Dereference
988 and then Is_Entity_Name (Nam)
989 and then No (First_Formal (Entity (Nam)))
990 and then Present (Actuals)))
992 Nam_Ent := Designated_Type (Etype (Nam));
993 Insert_Explicit_Dereference (Nam);
995 -- Selected component case. Simple entry or protected operation,
996 -- where the entry name is given by the selector name.
998 elsif Nkind (Nam) = N_Selected_Component then
999 Nam_Ent := Entity (Selector_Name (Nam));
1001 if not Ekind_In (Nam_Ent, E_Entry,
1006 Error_Msg_N ("name in call is not a callable entity", Nam);
1007 Set_Etype (N, Any_Type);
1011 -- If the name is an Indexed component, it can be a call to a member
1012 -- of an entry family. The prefix must be a selected component whose
1013 -- selector is the entry. Analyze_Procedure_Call normalizes several
1014 -- kinds of call into this form.
1016 elsif Nkind (Nam) = N_Indexed_Component then
1017 if Nkind (Prefix (Nam)) = N_Selected_Component then
1018 Nam_Ent := Entity (Selector_Name (Prefix (Nam)));
1020 Error_Msg_N ("name in call is not a callable entity", Nam);
1021 Set_Etype (N, Any_Type);
1025 elsif not Is_Entity_Name (Nam) then
1026 Error_Msg_N ("name in call is not a callable entity", Nam);
1027 Set_Etype (N, Any_Type);
1031 Nam_Ent := Entity (Nam);
1033 -- If no interpretations, give error message
1035 if not Is_Overloadable (Nam_Ent) then
1041 -- Operations generated for RACW stub types are called only through
1042 -- dispatching, and can never be the static interpretation of a call.
1044 if Is_RACW_Stub_Type_Operation (Nam_Ent) then
1049 Analyze_One_Call (N, Nam_Ent, True, Success);
1051 -- If this is an indirect call, the return type of the access_to
1052 -- subprogram may be an incomplete type. At the point of the call,
1053 -- use the full type if available, and at the same time update the
1054 -- return type of the access_to_subprogram.
1057 and then Nkind (Nam) = N_Explicit_Dereference
1058 and then Ekind (Etype (N)) = E_Incomplete_Type
1059 and then Present (Full_View (Etype (N)))
1061 Set_Etype (N, Full_View (Etype (N)));
1062 Set_Etype (Nam_Ent, Etype (N));
1066 -- An overloaded selected component must denote overloaded operations
1067 -- of a concurrent type. The interpretations are attached to the
1068 -- simple name of those operations.
1070 if Nkind (Nam) = N_Selected_Component then
1071 Nam := Selector_Name (Nam);
1074 Get_First_Interp (Nam, X, It);
1076 while Present (It.Nam) loop
1080 -- Name may be call that returns an access to subprogram, or more
1081 -- generally an overloaded expression one of whose interpretations
1082 -- yields an access to subprogram. If the name is an entity, we do
1083 -- not dereference, because the node is a call that returns the
1084 -- access type: note difference between f(x), where the call may
1085 -- return an access subprogram type, and f(x)(y), where the type
1086 -- returned by the call to f is implicitly dereferenced to analyze
1089 if Is_Access_Type (Nam_Ent) then
1090 Nam_Ent := Designated_Type (Nam_Ent);
1092 elsif Is_Access_Type (Etype (Nam_Ent))
1094 (not Is_Entity_Name (Nam)
1095 or else Nkind (N) = N_Procedure_Call_Statement)
1096 and then Ekind (Designated_Type (Etype (Nam_Ent)))
1099 Nam_Ent := Designated_Type (Etype (Nam_Ent));
1101 if Is_Entity_Name (Nam) then
1106 -- If the call has been rewritten from a prefixed call, the first
1107 -- parameter has been analyzed, but may need a subsequent
1108 -- dereference, so skip its analysis now.
1110 if N /= Original_Node (N)
1111 and then Nkind (Original_Node (N)) = Nkind (N)
1112 and then Nkind (Name (N)) /= Nkind (Name (Original_Node (N)))
1113 and then Present (Parameter_Associations (N))
1114 and then Present (Etype (First (Parameter_Associations (N))))
1117 (N, Nam_Ent, False, Success, Skip_First => True);
1119 Analyze_One_Call (N, Nam_Ent, False, Success);
1122 -- If the interpretation succeeds, mark the proper type of the
1123 -- prefix (any valid candidate will do). If not, remove the
1124 -- candidate interpretation. This only needs to be done for
1125 -- overloaded protected operations, for other entities disambi-
1126 -- guation is done directly in Resolve.
1130 and then Nkind (Parent (N)) /= N_Explicit_Dereference
1132 Set_Entity (Nam, It.Nam);
1133 Insert_Explicit_Dereference (Nam);
1134 Set_Etype (Nam, Nam_Ent);
1137 Set_Etype (Nam, It.Typ);
1140 elsif Nkind_In (Name (N), N_Selected_Component,
1146 Get_Next_Interp (X, It);
1149 -- If the name is the result of a function call, it can only
1150 -- be a call to a function returning an access to subprogram.
1151 -- Insert explicit dereference.
1153 if Nkind (Nam) = N_Function_Call then
1154 Insert_Explicit_Dereference (Nam);
1157 if Etype (N) = Any_Type then
1159 -- None of the interpretations is compatible with the actuals
1161 Diagnose_Call (N, Nam);
1163 -- Special checks for uninstantiated put routines
1165 if Nkind (N) = N_Procedure_Call_Statement
1166 and then Is_Entity_Name (Nam)
1167 and then Chars (Nam) = Name_Put
1168 and then List_Length (Actuals) = 1
1171 Arg : constant Node_Id := First (Actuals);
1175 if Nkind (Arg) = N_Parameter_Association then
1176 Typ := Etype (Explicit_Actual_Parameter (Arg));
1181 if Is_Signed_Integer_Type (Typ) then
1183 ("possible missing instantiation of " &
1184 "'Text_'I'O.'Integer_'I'O!", Nam);
1186 elsif Is_Modular_Integer_Type (Typ) then
1188 ("possible missing instantiation of " &
1189 "'Text_'I'O.'Modular_'I'O!", Nam);
1191 elsif Is_Floating_Point_Type (Typ) then
1193 ("possible missing instantiation of " &
1194 "'Text_'I'O.'Float_'I'O!", Nam);
1196 elsif Is_Ordinary_Fixed_Point_Type (Typ) then
1198 ("possible missing instantiation of " &
1199 "'Text_'I'O.'Fixed_'I'O!", Nam);
1201 elsif Is_Decimal_Fixed_Point_Type (Typ) then
1203 ("possible missing instantiation of " &
1204 "'Text_'I'O.'Decimal_'I'O!", Nam);
1206 elsif Is_Enumeration_Type (Typ) then
1208 ("possible missing instantiation of " &
1209 "'Text_'I'O.'Enumeration_'I'O!", Nam);
1214 elsif not Is_Overloaded (N)
1215 and then Is_Entity_Name (Nam)
1217 -- Resolution yields a single interpretation. Verify that the
1218 -- reference has capitalization consistent with the declaration.
1220 Set_Entity_With_Style_Check (Nam, Entity (Nam));
1221 Generate_Reference (Entity (Nam), Nam);
1223 Set_Etype (Nam, Etype (Entity (Nam)));
1225 Remove_Abstract_Operations (N);
1232 -----------------------------
1233 -- Analyze_Case_Expression --
1234 -----------------------------
1236 procedure Analyze_Case_Expression (N : Node_Id) is
1237 Expr : constant Node_Id := Expression (N);
1238 FirstX : constant Node_Id := Expression (First (Alternatives (N)));
1240 Exp_Type : Entity_Id;
1241 Exp_Btype : Entity_Id;
1243 Dont_Care : Boolean;
1244 Others_Present : Boolean;
1246 procedure Non_Static_Choice_Error (Choice : Node_Id);
1247 -- Error routine invoked by the generic instantiation below when
1248 -- the case expression has a non static choice.
1250 package Case_Choices_Processing is new
1251 Generic_Choices_Processing
1252 (Get_Alternatives => Alternatives,
1253 Get_Choices => Discrete_Choices,
1254 Process_Empty_Choice => No_OP,
1255 Process_Non_Static_Choice => Non_Static_Choice_Error,
1256 Process_Associated_Node => No_OP);
1257 use Case_Choices_Processing;
1259 -----------------------------
1260 -- Non_Static_Choice_Error --
1261 -----------------------------
1263 procedure Non_Static_Choice_Error (Choice : Node_Id) is
1265 Flag_Non_Static_Expr
1266 ("choice given in case expression is not static!", Choice);
1267 end Non_Static_Choice_Error;
1269 -- Start of processing for Analyze_Case_Expression
1272 if Comes_From_Source (N) then
1273 Check_Compiler_Unit (N);
1276 Analyze_And_Resolve (Expr, Any_Discrete);
1277 Check_Unset_Reference (Expr);
1278 Exp_Type := Etype (Expr);
1279 Exp_Btype := Base_Type (Exp_Type);
1281 Alt := First (Alternatives (N));
1282 while Present (Alt) loop
1283 Analyze (Expression (Alt));
1287 if not Is_Overloaded (FirstX) then
1288 Set_Etype (N, Etype (FirstX));
1296 Set_Etype (N, Any_Type);
1298 Get_First_Interp (FirstX, I, It);
1299 while Present (It.Nam) loop
1301 -- For each interpretation of the first expression, we only
1302 -- add the interpretation if every other expression in the
1303 -- case expression alternatives has a compatible type.
1305 Alt := Next (First (Alternatives (N)));
1306 while Present (Alt) loop
1307 exit when not Has_Compatible_Type (Expression (Alt), It.Typ);
1312 Add_One_Interp (N, It.Typ, It.Typ);
1315 Get_Next_Interp (I, It);
1320 Exp_Btype := Base_Type (Exp_Type);
1322 -- The expression must be of a discrete type which must be determinable
1323 -- independently of the context in which the expression occurs, but
1324 -- using the fact that the expression must be of a discrete type.
1325 -- Moreover, the type this expression must not be a character literal
1326 -- (which is always ambiguous).
1328 -- If error already reported by Resolve, nothing more to do
1330 if Exp_Btype = Any_Discrete
1331 or else Exp_Btype = Any_Type
1335 elsif Exp_Btype = Any_Character then
1337 ("character literal as case expression is ambiguous", Expr);
1341 -- If the case expression is a formal object of mode in out, then
1342 -- treat it as having a nonstatic subtype by forcing use of the base
1343 -- type (which has to get passed to Check_Case_Choices below). Also
1344 -- use base type when the case expression is parenthesized.
1346 if Paren_Count (Expr) > 0
1347 or else (Is_Entity_Name (Expr)
1348 and then Ekind (Entity (Expr)) = E_Generic_In_Out_Parameter)
1350 Exp_Type := Exp_Btype;
1353 -- Call instantiated Analyze_Choices which does the rest of the work
1355 Analyze_Choices (N, Exp_Type, Dont_Care, Others_Present);
1357 if Exp_Type = Universal_Integer and then not Others_Present then
1359 ("case on universal integer requires OTHERS choice", Expr);
1361 end Analyze_Case_Expression;
1363 ---------------------------
1364 -- Analyze_Comparison_Op --
1365 ---------------------------
1367 procedure Analyze_Comparison_Op (N : Node_Id) is
1368 L : constant Node_Id := Left_Opnd (N);
1369 R : constant Node_Id := Right_Opnd (N);
1370 Op_Id : Entity_Id := Entity (N);
1373 Set_Etype (N, Any_Type);
1374 Candidate_Type := Empty;
1376 Analyze_Expression (L);
1377 Analyze_Expression (R);
1379 if Present (Op_Id) then
1380 if Ekind (Op_Id) = E_Operator then
1381 Find_Comparison_Types (L, R, Op_Id, N);
1383 Add_One_Interp (N, Op_Id, Etype (Op_Id));
1386 if Is_Overloaded (L) then
1387 Set_Etype (L, Intersect_Types (L, R));
1391 Op_Id := Get_Name_Entity_Id (Chars (N));
1392 while Present (Op_Id) loop
1393 if Ekind (Op_Id) = E_Operator then
1394 Find_Comparison_Types (L, R, Op_Id, N);
1396 Analyze_User_Defined_Binary_Op (N, Op_Id);
1399 Op_Id := Homonym (Op_Id);
1404 end Analyze_Comparison_Op;
1406 ---------------------------
1407 -- Analyze_Concatenation --
1408 ---------------------------
1410 procedure Analyze_Concatenation (N : Node_Id) is
1412 -- We wish to avoid deep recursion, because concatenations are often
1413 -- deeply nested, as in A&B&...&Z. Therefore, we walk down the left
1414 -- operands nonrecursively until we find something that is not a
1415 -- concatenation (A in this case), or has already been analyzed. We
1416 -- analyze that, and then walk back up the tree following Parent
1417 -- pointers, calling Analyze_Concatenation_Rest to do the rest of the
1418 -- work at each level. The Parent pointers allow us to avoid recursion,
1419 -- and thus avoid running out of memory.
1425 Candidate_Type := Empty;
1427 -- The following code is equivalent to:
1429 -- Set_Etype (N, Any_Type);
1430 -- Analyze_Expression (Left_Opnd (N));
1431 -- Analyze_Concatenation_Rest (N);
1433 -- where the Analyze_Expression call recurses back here if the left
1434 -- operand is a concatenation.
1436 -- Walk down left operands
1439 Set_Etype (NN, Any_Type);
1440 L := Left_Opnd (NN);
1441 exit when Nkind (L) /= N_Op_Concat or else Analyzed (L);
1445 -- Now (given the above example) NN is A&B and L is A
1447 -- First analyze L ...
1449 Analyze_Expression (L);
1451 -- ... then walk NN back up until we reach N (where we started), calling
1452 -- Analyze_Concatenation_Rest along the way.
1455 Analyze_Concatenation_Rest (NN);
1459 end Analyze_Concatenation;
1461 --------------------------------
1462 -- Analyze_Concatenation_Rest --
1463 --------------------------------
1465 -- If the only one-dimensional array type in scope is String,
1466 -- this is the resulting type of the operation. Otherwise there
1467 -- will be a concatenation operation defined for each user-defined
1468 -- one-dimensional array.
1470 procedure Analyze_Concatenation_Rest (N : Node_Id) is
1471 L : constant Node_Id := Left_Opnd (N);
1472 R : constant Node_Id := Right_Opnd (N);
1473 Op_Id : Entity_Id := Entity (N);
1478 Analyze_Expression (R);
1480 -- If the entity is present, the node appears in an instance, and
1481 -- denotes a predefined concatenation operation. The resulting type is
1482 -- obtained from the arguments when possible. If the arguments are
1483 -- aggregates, the array type and the concatenation type must be
1486 if Present (Op_Id) then
1487 if Ekind (Op_Id) = E_Operator then
1488 LT := Base_Type (Etype (L));
1489 RT := Base_Type (Etype (R));
1491 if Is_Array_Type (LT)
1492 and then (RT = LT or else RT = Base_Type (Component_Type (LT)))
1494 Add_One_Interp (N, Op_Id, LT);
1496 elsif Is_Array_Type (RT)
1497 and then LT = Base_Type (Component_Type (RT))
1499 Add_One_Interp (N, Op_Id, RT);
1501 -- If one operand is a string type or a user-defined array type,
1502 -- and the other is a literal, result is of the specific type.
1505 (Root_Type (LT) = Standard_String
1506 or else Scope (LT) /= Standard_Standard)
1507 and then Etype (R) = Any_String
1509 Add_One_Interp (N, Op_Id, LT);
1512 (Root_Type (RT) = Standard_String
1513 or else Scope (RT) /= Standard_Standard)
1514 and then Etype (L) = Any_String
1516 Add_One_Interp (N, Op_Id, RT);
1518 elsif not Is_Generic_Type (Etype (Op_Id)) then
1519 Add_One_Interp (N, Op_Id, Etype (Op_Id));
1522 -- Type and its operations must be visible
1524 Set_Entity (N, Empty);
1525 Analyze_Concatenation (N);
1529 Add_One_Interp (N, Op_Id, Etype (Op_Id));
1533 Op_Id := Get_Name_Entity_Id (Name_Op_Concat);
1534 while Present (Op_Id) loop
1535 if Ekind (Op_Id) = E_Operator then
1537 -- Do not consider operators declared in dead code, they can
1538 -- not be part of the resolution.
1540 if Is_Eliminated (Op_Id) then
1543 Find_Concatenation_Types (L, R, Op_Id, N);
1547 Analyze_User_Defined_Binary_Op (N, Op_Id);
1550 Op_Id := Homonym (Op_Id);
1555 end Analyze_Concatenation_Rest;
1557 ------------------------------------
1558 -- Analyze_Conditional_Expression --
1559 ------------------------------------
1561 procedure Analyze_Conditional_Expression (N : Node_Id) is
1562 Condition : constant Node_Id := First (Expressions (N));
1563 Then_Expr : constant Node_Id := Next (Condition);
1564 Else_Expr : Node_Id;
1567 -- Defend against error of missing expressions from previous error
1569 if No (Then_Expr) then
1573 Check_SPARK_Restriction ("conditional expression is not allowed", N);
1575 Else_Expr := Next (Then_Expr);
1577 if Comes_From_Source (N) then
1578 Check_Compiler_Unit (N);
1581 Analyze_Expression (Condition);
1582 Analyze_Expression (Then_Expr);
1584 if Present (Else_Expr) then
1585 Analyze_Expression (Else_Expr);
1588 -- If then expression not overloaded, then that decides the type
1590 if not Is_Overloaded (Then_Expr) then
1591 Set_Etype (N, Etype (Then_Expr));
1593 -- Case where then expression is overloaded
1601 Set_Etype (N, Any_Type);
1603 -- Shouldn't the following statement be down in the ELSE of the
1604 -- following loop? ???
1606 Get_First_Interp (Then_Expr, I, It);
1608 -- if no Else_Expression the conditional must be boolean
1610 if No (Else_Expr) then
1611 Set_Etype (N, Standard_Boolean);
1613 -- Else_Expression Present. For each possible intepretation of
1614 -- the Then_Expression, add it only if the Else_Expression has
1615 -- a compatible type.
1618 while Present (It.Nam) loop
1619 if Has_Compatible_Type (Else_Expr, It.Typ) then
1620 Add_One_Interp (N, It.Typ, It.Typ);
1623 Get_Next_Interp (I, It);
1628 end Analyze_Conditional_Expression;
1630 -------------------------
1631 -- Analyze_Equality_Op --
1632 -------------------------
1634 procedure Analyze_Equality_Op (N : Node_Id) is
1635 Loc : constant Source_Ptr := Sloc (N);
1636 L : constant Node_Id := Left_Opnd (N);
1637 R : constant Node_Id := Right_Opnd (N);
1641 Set_Etype (N, Any_Type);
1642 Candidate_Type := Empty;
1644 Analyze_Expression (L);
1645 Analyze_Expression (R);
1647 -- If the entity is set, the node is a generic instance with a non-local
1648 -- reference to the predefined operator or to a user-defined function.
1649 -- It can also be an inequality that is expanded into the negation of a
1650 -- call to a user-defined equality operator.
1652 -- For the predefined case, the result is Boolean, regardless of the
1653 -- type of the operands. The operands may even be limited, if they are
1654 -- generic actuals. If they are overloaded, label the left argument with
1655 -- the common type that must be present, or with the type of the formal
1656 -- of the user-defined function.
1658 if Present (Entity (N)) then
1659 Op_Id := Entity (N);
1661 if Ekind (Op_Id) = E_Operator then
1662 Add_One_Interp (N, Op_Id, Standard_Boolean);
1664 Add_One_Interp (N, Op_Id, Etype (Op_Id));
1667 if Is_Overloaded (L) then
1668 if Ekind (Op_Id) = E_Operator then
1669 Set_Etype (L, Intersect_Types (L, R));
1671 Set_Etype (L, Etype (First_Formal (Op_Id)));
1676 Op_Id := Get_Name_Entity_Id (Chars (N));
1677 while Present (Op_Id) loop
1678 if Ekind (Op_Id) = E_Operator then
1679 Find_Equality_Types (L, R, Op_Id, N);
1681 Analyze_User_Defined_Binary_Op (N, Op_Id);
1684 Op_Id := Homonym (Op_Id);
1688 -- If there was no match, and the operator is inequality, this may
1689 -- be a case where inequality has not been made explicit, as for
1690 -- tagged types. Analyze the node as the negation of an equality
1691 -- operation. This cannot be done earlier, because before analysis
1692 -- we cannot rule out the presence of an explicit inequality.
1694 if Etype (N) = Any_Type
1695 and then Nkind (N) = N_Op_Ne
1697 Op_Id := Get_Name_Entity_Id (Name_Op_Eq);
1698 while Present (Op_Id) loop
1699 if Ekind (Op_Id) = E_Operator then
1700 Find_Equality_Types (L, R, Op_Id, N);
1702 Analyze_User_Defined_Binary_Op (N, Op_Id);
1705 Op_Id := Homonym (Op_Id);
1708 if Etype (N) /= Any_Type then
1709 Op_Id := Entity (N);
1715 Left_Opnd => Left_Opnd (N),
1716 Right_Opnd => Right_Opnd (N))));
1718 Set_Entity (Right_Opnd (N), Op_Id);
1724 end Analyze_Equality_Op;
1726 ----------------------------------
1727 -- Analyze_Explicit_Dereference --
1728 ----------------------------------
1730 procedure Analyze_Explicit_Dereference (N : Node_Id) is
1731 Loc : constant Source_Ptr := Sloc (N);
1732 P : constant Node_Id := Prefix (N);
1738 function Is_Function_Type return Boolean;
1739 -- Check whether node may be interpreted as an implicit function call
1741 ----------------------
1742 -- Is_Function_Type --
1743 ----------------------
1745 function Is_Function_Type return Boolean is
1750 if not Is_Overloaded (N) then
1751 return Ekind (Base_Type (Etype (N))) = E_Subprogram_Type
1752 and then Etype (Base_Type (Etype (N))) /= Standard_Void_Type;
1755 Get_First_Interp (N, I, It);
1756 while Present (It.Nam) loop
1757 if Ekind (Base_Type (It.Typ)) /= E_Subprogram_Type
1758 or else Etype (Base_Type (It.Typ)) = Standard_Void_Type
1763 Get_Next_Interp (I, It);
1768 end Is_Function_Type;
1770 -- Start of processing for Analyze_Explicit_Dereference
1773 -- If source node, check SPARK restriction. We guard this with the
1774 -- source node check, because ???
1776 if Comes_From_Source (N) then
1777 Check_SPARK_Restriction ("explicit dereference is not allowed", N);
1780 -- In formal verification mode, keep track of all reads and writes
1781 -- through explicit dereferences.
1784 Alfa.Generate_Dereference (N);
1788 Set_Etype (N, Any_Type);
1790 -- Test for remote access to subprogram type, and if so return
1791 -- after rewriting the original tree.
1793 if Remote_AST_E_Dereference (P) then
1797 -- Normal processing for other than remote access to subprogram type
1799 if not Is_Overloaded (P) then
1800 if Is_Access_Type (Etype (P)) then
1802 -- Set the Etype. We need to go through Is_For_Access_Subtypes to
1803 -- avoid other problems caused by the Private_Subtype and it is
1804 -- safe to go to the Base_Type because this is the same as
1805 -- converting the access value to its Base_Type.
1808 DT : Entity_Id := Designated_Type (Etype (P));
1811 if Ekind (DT) = E_Private_Subtype
1812 and then Is_For_Access_Subtype (DT)
1814 DT := Base_Type (DT);
1817 -- An explicit dereference is a legal occurrence of an
1818 -- incomplete type imported through a limited_with clause,
1819 -- if the full view is visible.
1821 if From_With_Type (DT)
1822 and then not From_With_Type (Scope (DT))
1824 (Is_Immediately_Visible (Scope (DT))
1826 (Is_Child_Unit (Scope (DT))
1827 and then Is_Visible_Child_Unit (Scope (DT))))
1829 Set_Etype (N, Available_View (DT));
1836 elsif Etype (P) /= Any_Type then
1837 Error_Msg_N ("prefix of dereference must be an access type", N);
1842 Get_First_Interp (P, I, It);
1843 while Present (It.Nam) loop
1846 if Is_Access_Type (T) then
1847 Add_One_Interp (N, Designated_Type (T), Designated_Type (T));
1850 Get_Next_Interp (I, It);
1853 -- Error if no interpretation of the prefix has an access type
1855 if Etype (N) = Any_Type then
1857 ("access type required in prefix of explicit dereference", P);
1858 Set_Etype (N, Any_Type);
1864 and then Nkind (Parent (N)) /= N_Indexed_Component
1866 and then (Nkind (Parent (N)) /= N_Function_Call
1867 or else N /= Name (Parent (N)))
1869 and then (Nkind (Parent (N)) /= N_Procedure_Call_Statement
1870 or else N /= Name (Parent (N)))
1872 and then Nkind (Parent (N)) /= N_Subprogram_Renaming_Declaration
1873 and then (Nkind (Parent (N)) /= N_Attribute_Reference
1875 (Attribute_Name (Parent (N)) /= Name_Address
1877 Attribute_Name (Parent (N)) /= Name_Access))
1879 -- Name is a function call with no actuals, in a context that
1880 -- requires deproceduring (including as an actual in an enclosing
1881 -- function or procedure call). There are some pathological cases
1882 -- where the prefix might include functions that return access to
1883 -- subprograms and others that return a regular type. Disambiguation
1884 -- of those has to take place in Resolve.
1887 Make_Function_Call (Loc,
1888 Name => Make_Explicit_Dereference (Loc, P),
1889 Parameter_Associations => New_List);
1891 -- If the prefix is overloaded, remove operations that have formals,
1892 -- we know that this is a parameterless call.
1894 if Is_Overloaded (P) then
1895 Get_First_Interp (P, I, It);
1896 while Present (It.Nam) loop
1899 if No (First_Formal (Base_Type (Designated_Type (T)))) then
1905 Get_Next_Interp (I, It);
1912 elsif not Is_Function_Type
1913 and then Is_Overloaded (N)
1915 -- The prefix may include access to subprograms and other access
1916 -- types. If the context selects the interpretation that is a
1917 -- function call (not a procedure call) we cannot rewrite the node
1918 -- yet, but we include the result of the call interpretation.
1920 Get_First_Interp (N, I, It);
1921 while Present (It.Nam) loop
1922 if Ekind (Base_Type (It.Typ)) = E_Subprogram_Type
1923 and then Etype (Base_Type (It.Typ)) /= Standard_Void_Type
1924 and then Nkind (Parent (N)) /= N_Procedure_Call_Statement
1926 Add_One_Interp (N, Etype (It.Typ), Etype (It.Typ));
1929 Get_Next_Interp (I, It);
1933 -- A value of remote access-to-class-wide must not be dereferenced
1936 Validate_Remote_Access_To_Class_Wide_Type (N);
1937 end Analyze_Explicit_Dereference;
1939 ------------------------
1940 -- Analyze_Expression --
1941 ------------------------
1943 procedure Analyze_Expression (N : Node_Id) is
1946 Check_Parameterless_Call (N);
1947 end Analyze_Expression;
1949 -------------------------------------
1950 -- Analyze_Expression_With_Actions --
1951 -------------------------------------
1953 procedure Analyze_Expression_With_Actions (N : Node_Id) is
1957 A := First (Actions (N));
1964 Analyze_Expression (Expression (N));
1965 Set_Etype (N, Etype (Expression (N)));
1966 end Analyze_Expression_With_Actions;
1968 ------------------------------------
1969 -- Analyze_Indexed_Component_Form --
1970 ------------------------------------
1972 procedure Analyze_Indexed_Component_Form (N : Node_Id) is
1973 P : constant Node_Id := Prefix (N);
1974 Exprs : constant List_Id := Expressions (N);
1980 procedure Process_Function_Call;
1981 -- Prefix in indexed component form is an overloadable entity,
1982 -- so the node is a function call. Reformat it as such.
1984 procedure Process_Indexed_Component;
1985 -- Prefix in indexed component form is actually an indexed component.
1986 -- This routine processes it, knowing that the prefix is already
1989 procedure Process_Indexed_Component_Or_Slice;
1990 -- An indexed component with a single index may designate a slice if
1991 -- the index is a subtype mark. This routine disambiguates these two
1992 -- cases by resolving the prefix to see if it is a subtype mark.
1994 procedure Process_Overloaded_Indexed_Component;
1995 -- If the prefix of an indexed component is overloaded, the proper
1996 -- interpretation is selected by the index types and the context.
1998 ---------------------------
1999 -- Process_Function_Call --
2000 ---------------------------
2002 procedure Process_Function_Call is
2006 Change_Node (N, N_Function_Call);
2008 Set_Parameter_Associations (N, Exprs);
2010 -- Analyze actuals prior to analyzing the call itself
2012 Actual := First (Parameter_Associations (N));
2013 while Present (Actual) loop
2015 Check_Parameterless_Call (Actual);
2017 -- Move to next actual. Note that we use Next, not Next_Actual
2018 -- here. The reason for this is a bit subtle. If a function call
2019 -- includes named associations, the parser recognizes the node as
2020 -- a call, and it is analyzed as such. If all associations are
2021 -- positional, the parser builds an indexed_component node, and
2022 -- it is only after analysis of the prefix that the construct
2023 -- is recognized as a call, in which case Process_Function_Call
2024 -- rewrites the node and analyzes the actuals. If the list of
2025 -- actuals is malformed, the parser may leave the node as an
2026 -- indexed component (despite the presence of named associations).
2027 -- The iterator Next_Actual is equivalent to Next if the list is
2028 -- positional, but follows the normalized chain of actuals when
2029 -- named associations are present. In this case normalization has
2030 -- not taken place, and actuals remain unanalyzed, which leads to
2031 -- subsequent crashes or loops if there is an attempt to continue
2032 -- analysis of the program.
2038 end Process_Function_Call;
2040 -------------------------------
2041 -- Process_Indexed_Component --
2042 -------------------------------
2044 procedure Process_Indexed_Component is
2046 Array_Type : Entity_Id;
2048 Pent : Entity_Id := Empty;
2051 Exp := First (Exprs);
2053 if Is_Overloaded (P) then
2054 Process_Overloaded_Indexed_Component;
2057 Array_Type := Etype (P);
2059 if Is_Entity_Name (P) then
2061 elsif Nkind (P) = N_Selected_Component
2062 and then Is_Entity_Name (Selector_Name (P))
2064 Pent := Entity (Selector_Name (P));
2067 -- Prefix must be appropriate for an array type, taking into
2068 -- account a possible implicit dereference.
2070 if Is_Access_Type (Array_Type) then
2071 Error_Msg_NW (Warn_On_Dereference, "?implicit dereference", N);
2072 Array_Type := Process_Implicit_Dereference_Prefix (Pent, P);
2075 if Is_Array_Type (Array_Type) then
2078 elsif Present (Pent) and then Ekind (Pent) = E_Entry_Family then
2080 Set_Etype (N, Any_Type);
2082 if not Has_Compatible_Type
2083 (Exp, Entry_Index_Type (Pent))
2085 Error_Msg_N ("invalid index type in entry name", N);
2087 elsif Present (Next (Exp)) then
2088 Error_Msg_N ("too many subscripts in entry reference", N);
2091 Set_Etype (N, Etype (P));
2096 elsif Is_Record_Type (Array_Type)
2097 and then Remote_AST_I_Dereference (P)
2101 elsif Try_Container_Indexing (N, P, Exp) then
2104 elsif Array_Type = Any_Type then
2105 Set_Etype (N, Any_Type);
2107 -- In most cases the analysis of the prefix will have emitted
2108 -- an error already, but if the prefix may be interpreted as a
2109 -- call in prefixed notation, the report is left to the caller.
2110 -- To prevent cascaded errors, report only if no previous ones.
2112 if Serious_Errors_Detected = 0 then
2113 Error_Msg_N ("invalid prefix in indexed component", P);
2115 if Nkind (P) = N_Expanded_Name then
2116 Error_Msg_NE ("\& is not visible", P, Selector_Name (P));
2122 -- Here we definitely have a bad indexing
2125 if Nkind (Parent (N)) = N_Requeue_Statement
2126 and then Present (Pent) and then Ekind (Pent) = E_Entry
2129 ("REQUEUE does not permit parameters", First (Exprs));
2131 elsif Is_Entity_Name (P)
2132 and then Etype (P) = Standard_Void_Type
2134 Error_Msg_NE ("incorrect use of&", P, Entity (P));
2137 Error_Msg_N ("array type required in indexed component", P);
2140 Set_Etype (N, Any_Type);
2144 Index := First_Index (Array_Type);
2145 while Present (Index) and then Present (Exp) loop
2146 if not Has_Compatible_Type (Exp, Etype (Index)) then
2147 Wrong_Type (Exp, Etype (Index));
2148 Set_Etype (N, Any_Type);
2156 Set_Etype (N, Component_Type (Array_Type));
2157 Check_Implicit_Dereference (N, Etype (N));
2159 if Present (Index) then
2161 ("too few subscripts in array reference", First (Exprs));
2163 elsif Present (Exp) then
2164 Error_Msg_N ("too many subscripts in array reference", Exp);
2167 end Process_Indexed_Component;
2169 ----------------------------------------
2170 -- Process_Indexed_Component_Or_Slice --
2171 ----------------------------------------
2173 procedure Process_Indexed_Component_Or_Slice is
2175 Exp := First (Exprs);
2176 while Present (Exp) loop
2177 Analyze_Expression (Exp);
2181 Exp := First (Exprs);
2183 -- If one index is present, and it is a subtype name, then the
2184 -- node denotes a slice (note that the case of an explicit range
2185 -- for a slice was already built as an N_Slice node in the first
2186 -- place, so that case is not handled here).
2188 -- We use a replace rather than a rewrite here because this is one
2189 -- of the cases in which the tree built by the parser is plain wrong.
2192 and then Is_Entity_Name (Exp)
2193 and then Is_Type (Entity (Exp))
2196 Make_Slice (Sloc (N),
2198 Discrete_Range => New_Copy (Exp)));
2201 -- Otherwise (more than one index present, or single index is not
2202 -- a subtype name), then we have the indexed component case.
2205 Process_Indexed_Component;
2207 end Process_Indexed_Component_Or_Slice;
2209 ------------------------------------------
2210 -- Process_Overloaded_Indexed_Component --
2211 ------------------------------------------
2213 procedure Process_Overloaded_Indexed_Component is
2222 Set_Etype (N, Any_Type);
2224 Get_First_Interp (P, I, It);
2225 while Present (It.Nam) loop
2228 if Is_Access_Type (Typ) then
2229 Typ := Designated_Type (Typ);
2230 Error_Msg_NW (Warn_On_Dereference, "?implicit dereference", N);
2233 if Is_Array_Type (Typ) then
2235 -- Got a candidate: verify that index types are compatible
2237 Index := First_Index (Typ);
2239 Exp := First (Exprs);
2240 while Present (Index) and then Present (Exp) loop
2241 if Has_Compatible_Type (Exp, Etype (Index)) then
2253 if Found and then No (Index) and then No (Exp) then
2255 CT : constant Entity_Id :=
2256 Base_Type (Component_Type (Typ));
2258 Add_One_Interp (N, CT, CT);
2259 Check_Implicit_Dereference (N, CT);
2263 elsif Try_Container_Indexing (N, P, First (Exprs)) then
2268 Get_Next_Interp (I, It);
2271 if Etype (N) = Any_Type then
2272 Error_Msg_N ("no legal interpretation for indexed component", N);
2273 Set_Is_Overloaded (N, False);
2277 end Process_Overloaded_Indexed_Component;
2279 -- Start of processing for Analyze_Indexed_Component_Form
2282 -- Get name of array, function or type
2286 if Nkind_In (N, N_Function_Call, N_Procedure_Call_Statement) then
2288 -- If P is an explicit dereference whose prefix is of a
2289 -- remote access-to-subprogram type, then N has already
2290 -- been rewritten as a subprogram call and analyzed.
2295 pragma Assert (Nkind (N) = N_Indexed_Component);
2297 P_T := Base_Type (Etype (P));
2299 if Is_Entity_Name (P) and then Present (Entity (P)) then
2302 if Is_Type (U_N) then
2304 -- Reformat node as a type conversion
2306 E := Remove_Head (Exprs);
2308 if Present (First (Exprs)) then
2310 ("argument of type conversion must be single expression", N);
2313 Change_Node (N, N_Type_Conversion);
2314 Set_Subtype_Mark (N, P);
2316 Set_Expression (N, E);
2318 -- After changing the node, call for the specific Analysis
2319 -- routine directly, to avoid a double call to the expander.
2321 Analyze_Type_Conversion (N);
2325 if Is_Overloadable (U_N) then
2326 Process_Function_Call;
2328 elsif Ekind (Etype (P)) = E_Subprogram_Type
2329 or else (Is_Access_Type (Etype (P))
2331 Ekind (Designated_Type (Etype (P))) =
2334 -- Call to access_to-subprogram with possible implicit dereference
2336 Process_Function_Call;
2338 elsif Is_Generic_Subprogram (U_N) then
2340 -- A common beginner's (or C++ templates fan) error
2342 Error_Msg_N ("generic subprogram cannot be called", N);
2343 Set_Etype (N, Any_Type);
2347 Process_Indexed_Component_Or_Slice;
2350 -- If not an entity name, prefix is an expression that may denote
2351 -- an array or an access-to-subprogram.
2354 if Ekind (P_T) = E_Subprogram_Type
2355 or else (Is_Access_Type (P_T)
2357 Ekind (Designated_Type (P_T)) = E_Subprogram_Type)
2359 Process_Function_Call;
2361 elsif Nkind (P) = N_Selected_Component
2362 and then Is_Overloadable (Entity (Selector_Name (P)))
2364 Process_Function_Call;
2367 -- Indexed component, slice, or a call to a member of a family
2368 -- entry, which will be converted to an entry call later.
2370 Process_Indexed_Component_Or_Slice;
2373 end Analyze_Indexed_Component_Form;
2375 ------------------------
2376 -- Analyze_Logical_Op --
2377 ------------------------
2379 procedure Analyze_Logical_Op (N : Node_Id) is
2380 L : constant Node_Id := Left_Opnd (N);
2381 R : constant Node_Id := Right_Opnd (N);
2382 Op_Id : Entity_Id := Entity (N);
2385 Set_Etype (N, Any_Type);
2386 Candidate_Type := Empty;
2388 Analyze_Expression (L);
2389 Analyze_Expression (R);
2391 if Present (Op_Id) then
2393 if Ekind (Op_Id) = E_Operator then
2394 Find_Boolean_Types (L, R, Op_Id, N);
2396 Add_One_Interp (N, Op_Id, Etype (Op_Id));
2400 Op_Id := Get_Name_Entity_Id (Chars (N));
2401 while Present (Op_Id) loop
2402 if Ekind (Op_Id) = E_Operator then
2403 Find_Boolean_Types (L, R, Op_Id, N);
2405 Analyze_User_Defined_Binary_Op (N, Op_Id);
2408 Op_Id := Homonym (Op_Id);
2413 end Analyze_Logical_Op;
2415 ---------------------------
2416 -- Analyze_Membership_Op --
2417 ---------------------------
2419 procedure Analyze_Membership_Op (N : Node_Id) is
2420 Loc : constant Source_Ptr := Sloc (N);
2421 L : constant Node_Id := Left_Opnd (N);
2422 R : constant Node_Id := Right_Opnd (N);
2424 Index : Interp_Index;
2426 Found : Boolean := False;
2430 procedure Try_One_Interp (T1 : Entity_Id);
2431 -- Routine to try one proposed interpretation. Note that the context
2432 -- of the operation plays no role in resolving the arguments, so that
2433 -- if there is more than one interpretation of the operands that is
2434 -- compatible with a membership test, the operation is ambiguous.
2436 --------------------
2437 -- Try_One_Interp --
2438 --------------------
2440 procedure Try_One_Interp (T1 : Entity_Id) is
2442 if Has_Compatible_Type (R, T1) then
2444 and then Base_Type (T1) /= Base_Type (T_F)
2446 It := Disambiguate (L, I_F, Index, Any_Type);
2448 if It = No_Interp then
2449 Ambiguous_Operands (N);
2450 Set_Etype (L, Any_Type);
2467 procedure Analyze_Set_Membership;
2468 -- If a set of alternatives is present, analyze each and find the
2469 -- common type to which they must all resolve.
2471 ----------------------------
2472 -- Analyze_Set_Membership --
2473 ----------------------------
2475 procedure Analyze_Set_Membership is
2477 Index : Interp_Index;
2479 Candidate_Interps : Node_Id;
2480 Common_Type : Entity_Id := Empty;
2484 Candidate_Interps := L;
2486 if not Is_Overloaded (L) then
2487 Common_Type := Etype (L);
2489 Alt := First (Alternatives (N));
2490 while Present (Alt) loop
2493 if not Has_Compatible_Type (Alt, Common_Type) then
2494 Wrong_Type (Alt, Common_Type);
2501 Alt := First (Alternatives (N));
2502 while Present (Alt) loop
2504 if not Is_Overloaded (Alt) then
2505 Common_Type := Etype (Alt);
2508 Get_First_Interp (Alt, Index, It);
2509 while Present (It.Typ) loop
2511 Has_Compatible_Type (Candidate_Interps, It.Typ)
2513 Remove_Interp (Index);
2516 Get_Next_Interp (Index, It);
2519 Get_First_Interp (Alt, Index, It);
2522 Error_Msg_N ("alternative has no legal type", Alt);
2526 -- If alternative is not overloaded, we have a unique type
2529 Set_Etype (Alt, It.Typ);
2530 Get_Next_Interp (Index, It);
2533 Set_Is_Overloaded (Alt, False);
2534 Common_Type := Etype (Alt);
2537 Candidate_Interps := Alt;
2544 Set_Etype (N, Standard_Boolean);
2546 if Present (Common_Type) then
2547 Set_Etype (L, Common_Type);
2548 Set_Is_Overloaded (L, False);
2551 Error_Msg_N ("cannot resolve membership operation", N);
2553 end Analyze_Set_Membership;
2555 -- Start of processing for Analyze_Membership_Op
2558 Analyze_Expression (L);
2561 and then Ada_Version >= Ada_2012
2563 Analyze_Set_Membership;
2567 if Nkind (R) = N_Range
2568 or else (Nkind (R) = N_Attribute_Reference
2569 and then Attribute_Name (R) = Name_Range)
2573 if not Is_Overloaded (L) then
2574 Try_One_Interp (Etype (L));
2577 Get_First_Interp (L, Index, It);
2578 while Present (It.Typ) loop
2579 Try_One_Interp (It.Typ);
2580 Get_Next_Interp (Index, It);
2584 -- If not a range, it can be a subtype mark, or else it is a degenerate
2585 -- membership test with a singleton value, i.e. a test for equality,
2586 -- if the types are compatible.
2591 if Is_Entity_Name (R)
2592 and then Is_Type (Entity (R))
2595 Check_Fully_Declared (Entity (R), R);
2597 elsif Ada_Version >= Ada_2012
2598 and then Has_Compatible_Type (R, Etype (L))
2600 if Nkind (N) = N_In then
2616 -- In all versions of the language, if we reach this point there
2617 -- is a previous error that will be diagnosed below.
2623 -- Compatibility between expression and subtype mark or range is
2624 -- checked during resolution. The result of the operation is Boolean
2627 Set_Etype (N, Standard_Boolean);
2629 if Comes_From_Source (N)
2630 and then Present (Right_Opnd (N))
2631 and then Is_CPP_Class (Etype (Etype (Right_Opnd (N))))
2633 Error_Msg_N ("membership test not applicable to cpp-class types", N);
2635 end Analyze_Membership_Op;
2637 ----------------------
2638 -- Analyze_Negation --
2639 ----------------------
2641 procedure Analyze_Negation (N : Node_Id) is
2642 R : constant Node_Id := Right_Opnd (N);
2643 Op_Id : Entity_Id := Entity (N);
2646 Set_Etype (N, Any_Type);
2647 Candidate_Type := Empty;
2649 Analyze_Expression (R);
2651 if Present (Op_Id) then
2652 if Ekind (Op_Id) = E_Operator then
2653 Find_Negation_Types (R, Op_Id, N);
2655 Add_One_Interp (N, Op_Id, Etype (Op_Id));
2659 Op_Id := Get_Name_Entity_Id (Chars (N));
2660 while Present (Op_Id) loop
2661 if Ekind (Op_Id) = E_Operator then
2662 Find_Negation_Types (R, Op_Id, N);
2664 Analyze_User_Defined_Unary_Op (N, Op_Id);
2667 Op_Id := Homonym (Op_Id);
2672 end Analyze_Negation;
2678 procedure Analyze_Null (N : Node_Id) is
2680 Check_SPARK_Restriction ("null is not allowed", N);
2682 Set_Etype (N, Any_Access);
2685 ----------------------
2686 -- Analyze_One_Call --
2687 ----------------------
2689 procedure Analyze_One_Call
2693 Success : out Boolean;
2694 Skip_First : Boolean := False)
2696 Actuals : constant List_Id := Parameter_Associations (N);
2697 Prev_T : constant Entity_Id := Etype (N);
2699 Must_Skip : constant Boolean := Skip_First
2700 or else Nkind (Original_Node (N)) = N_Selected_Component
2702 (Nkind (Original_Node (N)) = N_Indexed_Component
2703 and then Nkind (Prefix (Original_Node (N)))
2704 = N_Selected_Component);
2705 -- The first formal must be omitted from the match when trying to find
2706 -- a primitive operation that is a possible interpretation, and also
2707 -- after the call has been rewritten, because the corresponding actual
2708 -- is already known to be compatible, and because this may be an
2709 -- indexing of a call with default parameters.
2713 Is_Indexed : Boolean := False;
2714 Is_Indirect : Boolean := False;
2715 Subp_Type : constant Entity_Id := Etype (Nam);
2718 function Operator_Hidden_By (Fun : Entity_Id) return Boolean;
2719 -- There may be a user-defined operator that hides the current
2720 -- interpretation. We must check for this independently of the
2721 -- analysis of the call with the user-defined operation, because
2722 -- the parameter names may be wrong and yet the hiding takes place.
2723 -- This fixes a problem with ACATS test B34014O.
2725 -- When the type Address is a visible integer type, and the DEC
2726 -- system extension is visible, the predefined operator may be
2727 -- hidden as well, by one of the address operations in auxdec.
2728 -- Finally, The abstract operations on address do not hide the
2729 -- predefined operator (this is the purpose of making them abstract).
2731 procedure Indicate_Name_And_Type;
2732 -- If candidate interpretation matches, indicate name and type of
2733 -- result on call node.
2735 ----------------------------
2736 -- Indicate_Name_And_Type --
2737 ----------------------------
2739 procedure Indicate_Name_And_Type is
2741 Add_One_Interp (N, Nam, Etype (Nam));
2742 Check_Implicit_Dereference (N, Etype (Nam));
2745 -- If the prefix of the call is a name, indicate the entity
2746 -- being called. If it is not a name, it is an expression that
2747 -- denotes an access to subprogram or else an entry or family. In
2748 -- the latter case, the name is a selected component, and the entity
2749 -- being called is noted on the selector.
2751 if not Is_Type (Nam) then
2752 if Is_Entity_Name (Name (N)) then
2753 Set_Entity (Name (N), Nam);
2755 elsif Nkind (Name (N)) = N_Selected_Component then
2756 Set_Entity (Selector_Name (Name (N)), Nam);
2760 if Debug_Flag_E and not Report then
2761 Write_Str (" Overloaded call ");
2762 Write_Int (Int (N));
2763 Write_Str (" compatible with ");
2764 Write_Int (Int (Nam));
2767 end Indicate_Name_And_Type;
2769 ------------------------
2770 -- Operator_Hidden_By --
2771 ------------------------
2773 function Operator_Hidden_By (Fun : Entity_Id) return Boolean is
2774 Act1 : constant Node_Id := First_Actual (N);
2775 Act2 : constant Node_Id := Next_Actual (Act1);
2776 Form1 : constant Entity_Id := First_Formal (Fun);
2777 Form2 : constant Entity_Id := Next_Formal (Form1);
2780 if Ekind (Fun) /= E_Function
2781 or else Is_Abstract_Subprogram (Fun)
2785 elsif not Has_Compatible_Type (Act1, Etype (Form1)) then
2788 elsif Present (Form2) then
2790 No (Act2) or else not Has_Compatible_Type (Act2, Etype (Form2))
2795 elsif Present (Act2) then
2799 -- Now we know that the arity of the operator matches the function,
2800 -- and the function call is a valid interpretation. The function
2801 -- hides the operator if it has the right signature, or if one of
2802 -- its operands is a non-abstract operation on Address when this is
2803 -- a visible integer type.
2805 return Hides_Op (Fun, Nam)
2806 or else Is_Descendent_Of_Address (Etype (Form1))
2809 and then Is_Descendent_Of_Address (Etype (Form2)));
2810 end Operator_Hidden_By;
2812 -- Start of processing for Analyze_One_Call
2817 -- If the subprogram has no formals or if all the formals have defaults,
2818 -- and the return type is an array type, the node may denote an indexing
2819 -- of the result of a parameterless call. In Ada 2005, the subprogram
2820 -- may have one non-defaulted formal, and the call may have been written
2821 -- in prefix notation, so that the rebuilt parameter list has more than
2824 if not Is_Overloadable (Nam)
2825 and then Ekind (Nam) /= E_Subprogram_Type
2826 and then Ekind (Nam) /= E_Entry_Family
2831 -- An indexing requires at least one actual
2833 if not Is_Empty_List (Actuals)
2835 (Needs_No_Actuals (Nam)
2837 (Needs_One_Actual (Nam)
2838 and then Present (Next_Actual (First (Actuals)))))
2840 if Is_Array_Type (Subp_Type) then
2841 Is_Indexed := Try_Indexed_Call (N, Nam, Subp_Type, Must_Skip);
2843 elsif Is_Access_Type (Subp_Type)
2844 and then Is_Array_Type (Designated_Type (Subp_Type))
2848 (N, Nam, Designated_Type (Subp_Type), Must_Skip);
2850 -- The prefix can also be a parameterless function that returns an
2851 -- access to subprogram, in which case this is an indirect call.
2852 -- If this succeeds, an explicit dereference is added later on,
2853 -- in Analyze_Call or Resolve_Call.
2855 elsif Is_Access_Type (Subp_Type)
2856 and then Ekind (Designated_Type (Subp_Type)) = E_Subprogram_Type
2858 Is_Indirect := Try_Indirect_Call (N, Nam, Subp_Type);
2863 -- If the call has been transformed into a slice, it is of the form
2864 -- F (Subtype) where F is parameterless. The node has been rewritten in
2865 -- Try_Indexed_Call and there is nothing else to do.
2868 and then Nkind (N) = N_Slice
2874 (N, Nam, (Report and not Is_Indexed and not Is_Indirect), Norm_OK);
2878 -- If an indirect call is a possible interpretation, indicate
2879 -- success to the caller.
2885 -- Mismatch in number or names of parameters
2887 elsif Debug_Flag_E then
2888 Write_Str (" normalization fails in call ");
2889 Write_Int (Int (N));
2890 Write_Str (" with subprogram ");
2891 Write_Int (Int (Nam));
2895 -- If the context expects a function call, discard any interpretation
2896 -- that is a procedure. If the node is not overloaded, leave as is for
2897 -- better error reporting when type mismatch is found.
2899 elsif Nkind (N) = N_Function_Call
2900 and then Is_Overloaded (Name (N))
2901 and then Ekind (Nam) = E_Procedure
2905 -- Ditto for function calls in a procedure context
2907 elsif Nkind (N) = N_Procedure_Call_Statement
2908 and then Is_Overloaded (Name (N))
2909 and then Etype (Nam) /= Standard_Void_Type
2913 elsif No (Actuals) then
2915 -- If Normalize succeeds, then there are default parameters for
2918 Indicate_Name_And_Type;
2920 elsif Ekind (Nam) = E_Operator then
2921 if Nkind (N) = N_Procedure_Call_Statement then
2925 -- This can occur when the prefix of the call is an operator
2926 -- name or an expanded name whose selector is an operator name.
2928 Analyze_Operator_Call (N, Nam);
2930 if Etype (N) /= Prev_T then
2932 -- Check that operator is not hidden by a function interpretation
2934 if Is_Overloaded (Name (N)) then
2940 Get_First_Interp (Name (N), I, It);
2941 while Present (It.Nam) loop
2942 if Operator_Hidden_By (It.Nam) then
2943 Set_Etype (N, Prev_T);
2947 Get_Next_Interp (I, It);
2952 -- If operator matches formals, record its name on the call.
2953 -- If the operator is overloaded, Resolve will select the
2954 -- correct one from the list of interpretations. The call
2955 -- node itself carries the first candidate.
2957 Set_Entity (Name (N), Nam);
2960 elsif Report and then Etype (N) = Any_Type then
2961 Error_Msg_N ("incompatible arguments for operator", N);
2965 -- Normalize_Actuals has chained the named associations in the
2966 -- correct order of the formals.
2968 Actual := First_Actual (N);
2969 Formal := First_Formal (Nam);
2971 -- If we are analyzing a call rewritten from object notation, skip
2972 -- first actual, which may be rewritten later as an explicit
2976 Next_Actual (Actual);
2977 Next_Formal (Formal);
2980 while Present (Actual) and then Present (Formal) loop
2981 if Nkind (Parent (Actual)) /= N_Parameter_Association
2982 or else Chars (Selector_Name (Parent (Actual))) = Chars (Formal)
2984 -- The actual can be compatible with the formal, but we must
2985 -- also check that the context is not an address type that is
2986 -- visibly an integer type, as is the case in VMS_64. In this
2987 -- case the use of literals is illegal, except in the body of
2988 -- descendents of system, where arithmetic operations on
2989 -- address are of course used.
2991 if Has_Compatible_Type (Actual, Etype (Formal))
2993 (Etype (Actual) /= Universal_Integer
2994 or else not Is_Descendent_Of_Address (Etype (Formal))
2996 Is_Predefined_File_Name
2997 (Unit_File_Name (Get_Source_Unit (N))))
2999 Next_Actual (Actual);
3000 Next_Formal (Formal);
3003 if Debug_Flag_E then
3004 Write_Str (" type checking fails in call ");
3005 Write_Int (Int (N));
3006 Write_Str (" with formal ");
3007 Write_Int (Int (Formal));
3008 Write_Str (" in subprogram ");
3009 Write_Int (Int (Nam));
3013 if Report and not Is_Indexed and not Is_Indirect then
3015 -- Ada 2005 (AI-251): Complete the error notification
3016 -- to help new Ada 2005 users.
3018 if Is_Class_Wide_Type (Etype (Formal))
3019 and then Is_Interface (Etype (Etype (Formal)))
3020 and then not Interface_Present_In_Ancestor
3021 (Typ => Etype (Actual),
3022 Iface => Etype (Etype (Formal)))
3025 ("(Ada 2005) does not implement interface }",
3026 Actual, Etype (Etype (Formal)));
3029 Wrong_Type (Actual, Etype (Formal));
3031 if Nkind (Actual) = N_Op_Eq
3032 and then Nkind (Left_Opnd (Actual)) = N_Identifier
3034 Formal := First_Formal (Nam);
3035 while Present (Formal) loop
3036 if Chars (Left_Opnd (Actual)) = Chars (Formal) then
3037 Error_Msg_N -- CODEFIX
3038 ("possible misspelling of `='>`!", Actual);
3042 Next_Formal (Formal);
3046 if All_Errors_Mode then
3047 Error_Msg_Sloc := Sloc (Nam);
3049 if Etype (Formal) = Any_Type then
3051 ("there is no legal actual parameter", Actual);
3054 if Is_Overloadable (Nam)
3055 and then Present (Alias (Nam))
3056 and then not Comes_From_Source (Nam)
3059 ("\\ =='> in call to inherited operation & #!",
3062 elsif Ekind (Nam) = E_Subprogram_Type then
3064 Access_To_Subprogram_Typ :
3065 constant Entity_Id :=
3067 (Associated_Node_For_Itype (Nam));
3070 "\\ =='> in call to dereference of &#!",
3071 Actual, Access_To_Subprogram_Typ);
3076 ("\\ =='> in call to &#!", Actual, Nam);
3086 -- Normalize_Actuals has verified that a default value exists
3087 -- for this formal. Current actual names a subsequent formal.
3089 Next_Formal (Formal);
3093 -- On exit, all actuals match
3095 Indicate_Name_And_Type;
3097 end Analyze_One_Call;
3099 ---------------------------
3100 -- Analyze_Operator_Call --
3101 ---------------------------
3103 procedure Analyze_Operator_Call (N : Node_Id; Op_Id : Entity_Id) is
3104 Op_Name : constant Name_Id := Chars (Op_Id);
3105 Act1 : constant Node_Id := First_Actual (N);
3106 Act2 : constant Node_Id := Next_Actual (Act1);
3109 -- Binary operator case
3111 if Present (Act2) then
3113 -- If more than two operands, then not binary operator after all
3115 if Present (Next_Actual (Act2)) then
3118 elsif Op_Name = Name_Op_Add
3119 or else Op_Name = Name_Op_Subtract
3120 or else Op_Name = Name_Op_Multiply
3121 or else Op_Name = Name_Op_Divide
3122 or else Op_Name = Name_Op_Mod
3123 or else Op_Name = Name_Op_Rem
3124 or else Op_Name = Name_Op_Expon
3126 Find_Arithmetic_Types (Act1, Act2, Op_Id, N);
3128 elsif Op_Name = Name_Op_And
3129 or else Op_Name = Name_Op_Or
3130 or else Op_Name = Name_Op_Xor
3132 Find_Boolean_Types (Act1, Act2, Op_Id, N);
3134 elsif Op_Name = Name_Op_Lt
3135 or else Op_Name = Name_Op_Le
3136 or else Op_Name = Name_Op_Gt
3137 or else Op_Name = Name_Op_Ge
3139 Find_Comparison_Types (Act1, Act2, Op_Id, N);
3141 elsif Op_Name = Name_Op_Eq
3142 or else Op_Name = Name_Op_Ne
3144 Find_Equality_Types (Act1, Act2, Op_Id, N);
3146 elsif Op_Name = Name_Op_Concat then
3147 Find_Concatenation_Types (Act1, Act2, Op_Id, N);
3149 -- Is this else null correct, or should it be an abort???
3155 -- Unary operator case
3158 if Op_Name = Name_Op_Subtract or else
3159 Op_Name = Name_Op_Add or else
3160 Op_Name = Name_Op_Abs
3162 Find_Unary_Types (Act1, Op_Id, N);
3165 Op_Name = Name_Op_Not
3167 Find_Negation_Types (Act1, Op_Id, N);
3169 -- Is this else null correct, or should it be an abort???
3175 end Analyze_Operator_Call;
3177 -------------------------------------------
3178 -- Analyze_Overloaded_Selected_Component --
3179 -------------------------------------------
3181 procedure Analyze_Overloaded_Selected_Component (N : Node_Id) is
3182 Nam : constant Node_Id := Prefix (N);
3183 Sel : constant Node_Id := Selector_Name (N);
3190 Set_Etype (Sel, Any_Type);
3192 Get_First_Interp (Nam, I, It);
3193 while Present (It.Typ) loop
3194 if Is_Access_Type (It.Typ) then
3195 T := Designated_Type (It.Typ);
3196 Error_Msg_NW (Warn_On_Dereference, "?implicit dereference", N);
3201 -- Locate the component. For a private prefix the selector can denote
3204 if Is_Record_Type (T) or else Is_Private_Type (T) then
3206 -- If the prefix is a class-wide type, the visible components are
3207 -- those of the base type.
3209 if Is_Class_Wide_Type (T) then
3213 Comp := First_Entity (T);
3214 while Present (Comp) loop
3215 if Chars (Comp) = Chars (Sel)
3216 and then Is_Visible_Component (Comp)
3219 -- AI05-105: if the context is an object renaming with
3220 -- an anonymous access type, the expected type of the
3221 -- object must be anonymous. This is a name resolution rule.
3223 if Nkind (Parent (N)) /= N_Object_Renaming_Declaration
3224 or else No (Access_Definition (Parent (N)))
3225 or else Ekind (Etype (Comp)) = E_Anonymous_Access_Type
3227 Ekind (Etype (Comp)) = E_Anonymous_Access_Subprogram_Type
3229 Set_Entity (Sel, Comp);
3230 Set_Etype (Sel, Etype (Comp));
3231 Add_One_Interp (N, Etype (Comp), Etype (Comp));
3232 Check_Implicit_Dereference (N, Etype (Comp));
3234 -- This also specifies a candidate to resolve the name.
3235 -- Further overloading will be resolved from context.
3236 -- The selector name itself does not carry overloading
3239 Set_Etype (Nam, It.Typ);
3242 -- Named access type in the context of a renaming
3243 -- declaration with an access definition. Remove
3244 -- inapplicable candidate.
3253 elsif Is_Concurrent_Type (T) then
3254 Comp := First_Entity (T);
3255 while Present (Comp)
3256 and then Comp /= First_Private_Entity (T)
3258 if Chars (Comp) = Chars (Sel) then
3259 if Is_Overloadable (Comp) then
3260 Add_One_Interp (Sel, Comp, Etype (Comp));
3262 Set_Entity_With_Style_Check (Sel, Comp);
3263 Generate_Reference (Comp, Sel);
3266 Set_Etype (Sel, Etype (Comp));
3267 Set_Etype (N, Etype (Comp));
3268 Set_Etype (Nam, It.Typ);
3270 -- For access type case, introduce explicit dereference for
3271 -- more uniform treatment of entry calls. Do this only once
3272 -- if several interpretations yield an access type.
3274 if Is_Access_Type (Etype (Nam))
3275 and then Nkind (Nam) /= N_Explicit_Dereference
3277 Insert_Explicit_Dereference (Nam);
3279 (Warn_On_Dereference, "?implicit dereference", N);
3286 Set_Is_Overloaded (N, Is_Overloaded (Sel));
3289 Get_Next_Interp (I, It);
3292 if Etype (N) = Any_Type
3293 and then not Try_Object_Operation (N)
3295 Error_Msg_NE ("undefined selector& for overloaded prefix", N, Sel);
3296 Set_Entity (Sel, Any_Id);
3297 Set_Etype (Sel, Any_Type);
3299 end Analyze_Overloaded_Selected_Component;
3301 ----------------------------------
3302 -- Analyze_Qualified_Expression --
3303 ----------------------------------
3305 procedure Analyze_Qualified_Expression (N : Node_Id) is
3306 Mark : constant Entity_Id := Subtype_Mark (N);
3307 Expr : constant Node_Id := Expression (N);
3313 Analyze_Expression (Expr);
3315 Set_Etype (N, Any_Type);
3320 if T = Any_Type then
3324 Check_Fully_Declared (T, N);
3326 -- If expected type is class-wide, check for exact match before
3327 -- expansion, because if the expression is a dispatching call it
3328 -- may be rewritten as explicit dereference with class-wide result.
3329 -- If expression is overloaded, retain only interpretations that
3330 -- will yield exact matches.
3332 if Is_Class_Wide_Type (T) then
3333 if not Is_Overloaded (Expr) then
3334 if Base_Type (Etype (Expr)) /= Base_Type (T) then
3335 if Nkind (Expr) = N_Aggregate then
3336 Error_Msg_N ("type of aggregate cannot be class-wide", Expr);
3338 Wrong_Type (Expr, T);
3343 Get_First_Interp (Expr, I, It);
3345 while Present (It.Nam) loop
3346 if Base_Type (It.Typ) /= Base_Type (T) then
3350 Get_Next_Interp (I, It);
3356 end Analyze_Qualified_Expression;
3358 -----------------------------------
3359 -- Analyze_Quantified_Expression --
3360 -----------------------------------
3362 procedure Analyze_Quantified_Expression (N : Node_Id) is
3363 Loc : constant Source_Ptr := Sloc (N);
3364 Ent : constant Entity_Id :=
3366 (E_Loop, Current_Scope, Sloc (N), 'L');
3371 Set_Etype (Ent, Standard_Void_Type);
3372 Set_Scope (Ent, Current_Scope);
3373 Set_Parent (Ent, N);
3375 Check_SPARK_Restriction ("quantified expression is not allowed", N);
3377 -- If expansion is enabled (and not in Alfa mode), the condition is
3378 -- analyzed after rewritten as a loop. So we only need to set the type.
3380 if Operating_Mode /= Check_Semantics
3381 and then not Alfa_Mode
3383 Set_Etype (N, Standard_Boolean);
3387 if Present (Loop_Parameter_Specification (N)) then
3389 Make_Iteration_Scheme (Loc,
3390 Loop_Parameter_Specification =>
3391 Loop_Parameter_Specification (N));
3394 Make_Iteration_Scheme (Loc,
3395 Iterator_Specification =>
3396 Iterator_Specification (N));
3400 Set_Parent (Iterator, N);
3401 Analyze_Iteration_Scheme (Iterator);
3403 -- The loop specification may have been converted into an iterator
3404 -- specification during its analysis. Update the quantified node
3407 if Present (Iterator_Specification (Iterator)) then
3408 Set_Iterator_Specification
3409 (N, Iterator_Specification (Iterator));
3410 Set_Loop_Parameter_Specification (N, Empty);
3413 Analyze (Condition (N));
3415 Set_Etype (N, Standard_Boolean);
3416 end Analyze_Quantified_Expression;
3422 procedure Analyze_Range (N : Node_Id) is
3423 L : constant Node_Id := Low_Bound (N);
3424 H : constant Node_Id := High_Bound (N);
3425 I1, I2 : Interp_Index;
3428 procedure Check_Common_Type (T1, T2 : Entity_Id);
3429 -- Verify the compatibility of two types, and choose the
3430 -- non universal one if the other is universal.
3432 procedure Check_High_Bound (T : Entity_Id);
3433 -- Test one interpretation of the low bound against all those
3434 -- of the high bound.
3436 procedure Check_Universal_Expression (N : Node_Id);
3437 -- In Ada83, reject bounds of a universal range that are not literals or
3440 -----------------------
3441 -- Check_Common_Type --
3442 -----------------------
3444 procedure Check_Common_Type (T1, T2 : Entity_Id) is
3446 if Covers (T1 => T1, T2 => T2)
3448 Covers (T1 => T2, T2 => T1)
3450 if T1 = Universal_Integer
3451 or else T1 = Universal_Real
3452 or else T1 = Any_Character
3454 Add_One_Interp (N, Base_Type (T2), Base_Type (T2));
3457 Add_One_Interp (N, T1, T1);
3460 Add_One_Interp (N, Base_Type (T1), Base_Type (T1));
3463 end Check_Common_Type;
3465 ----------------------
3466 -- Check_High_Bound --
3467 ----------------------
3469 procedure Check_High_Bound (T : Entity_Id) is
3471 if not Is_Overloaded (H) then
3472 Check_Common_Type (T, Etype (H));
3474 Get_First_Interp (H, I2, It2);
3475 while Present (It2.Typ) loop
3476 Check_Common_Type (T, It2.Typ);
3477 Get_Next_Interp (I2, It2);
3480 end Check_High_Bound;
3482 -----------------------------
3483 -- Is_Universal_Expression --
3484 -----------------------------
3486 procedure Check_Universal_Expression (N : Node_Id) is
3488 if Etype (N) = Universal_Integer
3489 and then Nkind (N) /= N_Integer_Literal
3490 and then not Is_Entity_Name (N)
3491 and then Nkind (N) /= N_Attribute_Reference
3493 Error_Msg_N ("illegal bound in discrete range", N);
3495 end Check_Universal_Expression;
3497 -- Start of processing for Analyze_Range
3500 Set_Etype (N, Any_Type);
3501 Analyze_Expression (L);
3502 Analyze_Expression (H);
3504 if Etype (L) = Any_Type or else Etype (H) = Any_Type then
3508 if not Is_Overloaded (L) then
3509 Check_High_Bound (Etype (L));
3511 Get_First_Interp (L, I1, It1);
3512 while Present (It1.Typ) loop
3513 Check_High_Bound (It1.Typ);
3514 Get_Next_Interp (I1, It1);
3518 -- If result is Any_Type, then we did not find a compatible pair
3520 if Etype (N) = Any_Type then
3521 Error_Msg_N ("incompatible types in range ", N);
3525 if Ada_Version = Ada_83
3527 (Nkind (Parent (N)) = N_Loop_Parameter_Specification
3528 or else Nkind (Parent (N)) = N_Constrained_Array_Definition)
3530 Check_Universal_Expression (L);
3531 Check_Universal_Expression (H);
3535 -----------------------
3536 -- Analyze_Reference --
3537 -----------------------
3539 procedure Analyze_Reference (N : Node_Id) is
3540 P : constant Node_Id := Prefix (N);
3543 Acc_Type : Entity_Id;
3548 -- An interesting error check, if we take the 'Reference of an object
3549 -- for which a pragma Atomic or Volatile has been given, and the type
3550 -- of the object is not Atomic or Volatile, then we are in trouble. The
3551 -- problem is that no trace of the atomic/volatile status will remain
3552 -- for the backend to respect when it deals with the resulting pointer,
3553 -- since the pointer type will not be marked atomic (it is a pointer to
3554 -- the base type of the object).
3556 -- It is not clear if that can ever occur, but in case it does, we will
3557 -- generate an error message. Not clear if this message can ever be
3558 -- generated, and pretty clear that it represents a bug if it is, still
3559 -- seems worth checking, except in CodePeer mode where we do not really
3560 -- care and don't want to bother the user.
3564 if Is_Entity_Name (P)
3565 and then Is_Object_Reference (P)
3566 and then not CodePeer_Mode
3571 if (Has_Atomic_Components (E)
3572 and then not Has_Atomic_Components (T))
3574 (Has_Volatile_Components (E)
3575 and then not Has_Volatile_Components (T))
3576 or else (Is_Atomic (E) and then not Is_Atomic (T))
3577 or else (Is_Volatile (E) and then not Is_Volatile (T))
3579 Error_Msg_N ("cannot take reference to Atomic/Volatile object", N);
3583 -- Carry on with normal processing
3585 Acc_Type := Create_Itype (E_Allocator_Type, N);
3586 Set_Etype (Acc_Type, Acc_Type);
3587 Set_Directly_Designated_Type (Acc_Type, Etype (P));
3588 Set_Etype (N, Acc_Type);
3589 end Analyze_Reference;
3591 --------------------------------
3592 -- Analyze_Selected_Component --
3593 --------------------------------
3595 -- Prefix is a record type or a task or protected type. In the latter case,
3596 -- the selector must denote a visible entry.
3598 procedure Analyze_Selected_Component (N : Node_Id) is
3599 Name : constant Node_Id := Prefix (N);
3600 Sel : constant Node_Id := Selector_Name (N);
3603 Has_Candidate : Boolean := False;
3606 Pent : Entity_Id := Empty;
3607 Prefix_Type : Entity_Id;
3609 Type_To_Use : Entity_Id;
3610 -- In most cases this is the Prefix_Type, but if the Prefix_Type is
3611 -- a class-wide type, we use its root type, whose components are
3612 -- present in the class-wide type.
3614 Is_Single_Concurrent_Object : Boolean;
3615 -- Set True if the prefix is a single task or a single protected object
3617 procedure Find_Component_In_Instance (Rec : Entity_Id);
3618 -- In an instance, a component of a private extension may not be visible
3619 -- while it was visible in the generic. Search candidate scope for a
3620 -- component with the proper identifier. This is only done if all other
3621 -- searches have failed. When the match is found (it always will be),
3622 -- the Etype of both N and Sel are set from this component, and the
3623 -- entity of Sel is set to reference this component.
3625 function Has_Mode_Conformant_Spec (Comp : Entity_Id) return Boolean;
3626 -- It is known that the parent of N denotes a subprogram call. Comp
3627 -- is an overloadable component of the concurrent type of the prefix.
3628 -- Determine whether all formals of the parent of N and Comp are mode
3629 -- conformant. If the parent node is not analyzed yet it may be an
3630 -- indexed component rather than a function call.
3632 --------------------------------
3633 -- Find_Component_In_Instance --
3634 --------------------------------
3636 procedure Find_Component_In_Instance (Rec : Entity_Id) is
3640 Comp := First_Component (Rec);
3641 while Present (Comp) loop
3642 if Chars (Comp) = Chars (Sel) then
3643 Set_Entity_With_Style_Check (Sel, Comp);
3644 Set_Etype (Sel, Etype (Comp));
3645 Set_Etype (N, Etype (Comp));
3649 Next_Component (Comp);
3652 -- This must succeed because code was legal in the generic
3654 raise Program_Error;
3655 end Find_Component_In_Instance;
3657 ------------------------------
3658 -- Has_Mode_Conformant_Spec --
3659 ------------------------------
3661 function Has_Mode_Conformant_Spec (Comp : Entity_Id) return Boolean is
3662 Comp_Param : Entity_Id;
3664 Param_Typ : Entity_Id;
3667 Comp_Param := First_Formal (Comp);
3669 if Nkind (Parent (N)) = N_Indexed_Component then
3670 Param := First (Expressions (Parent (N)));
3672 Param := First (Parameter_Associations (Parent (N)));
3675 while Present (Comp_Param)
3676 and then Present (Param)
3678 Param_Typ := Find_Parameter_Type (Param);
3680 if Present (Param_Typ)
3682 not Conforming_Types
3683 (Etype (Comp_Param), Param_Typ, Mode_Conformant)
3688 Next_Formal (Comp_Param);
3692 -- One of the specs has additional formals
3694 if Present (Comp_Param) or else Present (Param) then
3699 end Has_Mode_Conformant_Spec;
3701 -- Start of processing for Analyze_Selected_Component
3704 Set_Etype (N, Any_Type);
3706 if Is_Overloaded (Name) then
3707 Analyze_Overloaded_Selected_Component (N);
3710 elsif Etype (Name) = Any_Type then
3711 Set_Entity (Sel, Any_Id);
3712 Set_Etype (Sel, Any_Type);
3716 Prefix_Type := Etype (Name);
3719 if Is_Access_Type (Prefix_Type) then
3721 -- A RACW object can never be used as prefix of a selected component
3722 -- since that means it is dereferenced without being a controlling
3723 -- operand of a dispatching operation (RM E.2.2(16/1)). Before
3724 -- reporting an error, we must check whether this is actually a
3725 -- dispatching call in prefix form.
3727 if Is_Remote_Access_To_Class_Wide_Type (Prefix_Type)
3728 and then Comes_From_Source (N)
3730 if Try_Object_Operation (N) then
3734 ("invalid dereference of a remote access-to-class-wide value",
3738 -- Normal case of selected component applied to access type
3741 Error_Msg_NW (Warn_On_Dereference, "?implicit dereference", N);
3743 if Is_Entity_Name (Name) then
3744 Pent := Entity (Name);
3745 elsif Nkind (Name) = N_Selected_Component
3746 and then Is_Entity_Name (Selector_Name (Name))
3748 Pent := Entity (Selector_Name (Name));
3751 Prefix_Type := Process_Implicit_Dereference_Prefix (Pent, Name);
3754 -- If we have an explicit dereference of a remote access-to-class-wide
3755 -- value, then issue an error (see RM-E.2.2(16/1)). However we first
3756 -- have to check for the case of a prefix that is a controlling operand
3757 -- of a prefixed dispatching call, as the dereference is legal in that
3758 -- case. Normally this condition is checked in Validate_Remote_Access_
3759 -- To_Class_Wide_Type, but we have to defer the checking for selected
3760 -- component prefixes because of the prefixed dispatching call case.
3761 -- Note that implicit dereferences are checked for this just above.
3763 elsif Nkind (Name) = N_Explicit_Dereference
3764 and then Is_Remote_Access_To_Class_Wide_Type (Etype (Prefix (Name)))
3765 and then Comes_From_Source (N)
3767 if Try_Object_Operation (N) then
3771 ("invalid dereference of a remote access-to-class-wide value",
3776 -- (Ada 2005): if the prefix is the limited view of a type, and
3777 -- the context already includes the full view, use the full view
3778 -- in what follows, either to retrieve a component of to find
3779 -- a primitive operation. If the prefix is an explicit dereference,
3780 -- set the type of the prefix to reflect this transformation.
3781 -- If the non-limited view is itself an incomplete type, get the
3782 -- full view if available.
3784 if Is_Incomplete_Type (Prefix_Type)
3785 and then From_With_Type (Prefix_Type)
3786 and then Present (Non_Limited_View (Prefix_Type))
3788 Prefix_Type := Get_Full_View (Non_Limited_View (Prefix_Type));
3790 if Nkind (N) = N_Explicit_Dereference then
3791 Set_Etype (Prefix (N), Prefix_Type);
3794 elsif Ekind (Prefix_Type) = E_Class_Wide_Type
3795 and then From_With_Type (Prefix_Type)
3796 and then Present (Non_Limited_View (Etype (Prefix_Type)))
3799 Class_Wide_Type (Non_Limited_View (Etype (Prefix_Type)));
3801 if Nkind (N) = N_Explicit_Dereference then
3802 Set_Etype (Prefix (N), Prefix_Type);
3806 if Ekind (Prefix_Type) = E_Private_Subtype then
3807 Prefix_Type := Base_Type (Prefix_Type);
3810 Type_To_Use := Prefix_Type;
3812 -- For class-wide types, use the entity list of the root type. This
3813 -- indirection is specially important for private extensions because
3814 -- only the root type get switched (not the class-wide type).
3816 if Is_Class_Wide_Type (Prefix_Type) then
3817 Type_To_Use := Root_Type (Prefix_Type);
3820 -- If the prefix is a single concurrent object, use its name in error
3821 -- messages, rather than that of its anonymous type.
3823 Is_Single_Concurrent_Object :=
3824 Is_Concurrent_Type (Prefix_Type)
3825 and then Is_Internal_Name (Chars (Prefix_Type))
3826 and then not Is_Derived_Type (Prefix_Type)
3827 and then Is_Entity_Name (Name);
3829 Comp := First_Entity (Type_To_Use);
3831 -- If the selector has an original discriminant, the node appears in
3832 -- an instance. Replace the discriminant with the corresponding one
3833 -- in the current discriminated type. For nested generics, this must
3834 -- be done transitively, so note the new original discriminant.
3836 if Nkind (Sel) = N_Identifier
3837 and then In_Instance
3838 and then Present (Original_Discriminant (Sel))
3840 Comp := Find_Corresponding_Discriminant (Sel, Prefix_Type);
3842 -- Mark entity before rewriting, for completeness and because
3843 -- subsequent semantic checks might examine the original node.
3845 Set_Entity (Sel, Comp);
3846 Rewrite (Selector_Name (N),
3847 New_Occurrence_Of (Comp, Sloc (N)));
3848 Set_Original_Discriminant (Selector_Name (N), Comp);
3849 Set_Etype (N, Etype (Comp));
3850 Check_Implicit_Dereference (N, Etype (Comp));
3852 if Is_Access_Type (Etype (Name)) then
3853 Insert_Explicit_Dereference (Name);
3854 Error_Msg_NW (Warn_On_Dereference, "?implicit dereference", N);
3857 elsif Is_Record_Type (Prefix_Type) then
3859 -- Find component with given name
3861 while Present (Comp) loop
3862 if Chars (Comp) = Chars (Sel)
3863 and then Is_Visible_Component (Comp)
3865 Set_Entity_With_Style_Check (Sel, Comp);
3866 Set_Etype (Sel, Etype (Comp));
3868 if Ekind (Comp) = E_Discriminant then
3869 if Is_Unchecked_Union (Base_Type (Prefix_Type)) then
3871 ("cannot reference discriminant of Unchecked_Union",
3875 if Is_Generic_Type (Prefix_Type)
3877 Is_Generic_Type (Root_Type (Prefix_Type))
3879 Set_Original_Discriminant (Sel, Comp);
3883 -- Resolve the prefix early otherwise it is not possible to
3884 -- build the actual subtype of the component: it may need
3885 -- to duplicate this prefix and duplication is only allowed
3886 -- on fully resolved expressions.
3890 -- Ada 2005 (AI-50217): Check wrong use of incomplete types or
3891 -- subtypes in a package specification.
3894 -- limited with Pkg;
3896 -- type Acc_Inc is access Pkg.T;
3898 -- N : Natural := X.all.Comp; -- ERROR, limited view
3899 -- end Pkg; -- Comp is not visible
3901 if Nkind (Name) = N_Explicit_Dereference
3902 and then From_With_Type (Etype (Prefix (Name)))
3903 and then not Is_Potentially_Use_Visible (Etype (Name))
3904 and then Nkind (Parent (Cunit_Entity (Current_Sem_Unit))) =
3905 N_Package_Specification
3908 ("premature usage of incomplete}", Prefix (Name),
3909 Etype (Prefix (Name)));
3912 -- We never need an actual subtype for the case of a selection
3913 -- for a indexed component of a non-packed array, since in
3914 -- this case gigi generates all the checks and can find the
3915 -- necessary bounds information.
3917 -- We also do not need an actual subtype for the case of a
3918 -- first, last, length, or range attribute applied to a
3919 -- non-packed array, since gigi can again get the bounds in
3920 -- these cases (gigi cannot handle the packed case, since it
3921 -- has the bounds of the packed array type, not the original
3922 -- bounds of the type). However, if the prefix is itself a
3923 -- selected component, as in a.b.c (i), gigi may regard a.b.c
3924 -- as a dynamic-sized temporary, so we do generate an actual
3925 -- subtype for this case.
3927 Parent_N := Parent (N);
3929 if not Is_Packed (Etype (Comp))
3931 ((Nkind (Parent_N) = N_Indexed_Component
3932 and then Nkind (Name) /= N_Selected_Component)
3934 (Nkind (Parent_N) = N_Attribute_Reference
3935 and then (Attribute_Name (Parent_N) = Name_First
3937 Attribute_Name (Parent_N) = Name_Last
3939 Attribute_Name (Parent_N) = Name_Length
3941 Attribute_Name (Parent_N) = Name_Range)))
3943 Set_Etype (N, Etype (Comp));
3945 -- If full analysis is not enabled, we do not generate an
3946 -- actual subtype, because in the absence of expansion
3947 -- reference to a formal of a protected type, for example,
3948 -- will not be properly transformed, and will lead to
3949 -- out-of-scope references in gigi.
3951 -- In all other cases, we currently build an actual subtype.
3952 -- It seems likely that many of these cases can be avoided,
3953 -- but right now, the front end makes direct references to the
3954 -- bounds (e.g. in generating a length check), and if we do
3955 -- not make an actual subtype, we end up getting a direct
3956 -- reference to a discriminant, which will not do.
3958 elsif Full_Analysis then
3960 Build_Actual_Subtype_Of_Component (Etype (Comp), N);
3961 Insert_Action (N, Act_Decl);
3963 if No (Act_Decl) then
3964 Set_Etype (N, Etype (Comp));
3967 -- Component type depends on discriminants. Enter the
3968 -- main attributes of the subtype.
3971 Subt : constant Entity_Id :=
3972 Defining_Identifier (Act_Decl);
3975 Set_Etype (Subt, Base_Type (Etype (Comp)));
3976 Set_Ekind (Subt, Ekind (Etype (Comp)));
3977 Set_Etype (N, Subt);
3981 -- If Full_Analysis not enabled, just set the Etype
3984 Set_Etype (N, Etype (Comp));
3987 Check_Implicit_Dereference (N, Etype (N));
3991 -- If the prefix is a private extension, check only the visible
3992 -- components of the partial view. This must include the tag,
3993 -- which can appear in expanded code in a tag check.
3995 if Ekind (Type_To_Use) = E_Record_Type_With_Private
3996 and then Chars (Selector_Name (N)) /= Name_uTag
3998 exit when Comp = Last_Entity (Type_To_Use);
4004 -- Ada 2005 (AI-252): The selected component can be interpreted as
4005 -- a prefixed view of a subprogram. Depending on the context, this is
4006 -- either a name that can appear in a renaming declaration, or part
4007 -- of an enclosing call given in prefix form.
4009 -- Ada 2005 (AI05-0030): In the case of dispatching requeue, the
4010 -- selected component should resolve to a name.
4012 if Ada_Version >= Ada_2005
4013 and then Is_Tagged_Type (Prefix_Type)
4014 and then not Is_Concurrent_Type (Prefix_Type)
4016 if Nkind (Parent (N)) = N_Generic_Association
4017 or else Nkind (Parent (N)) = N_Requeue_Statement
4018 or else Nkind (Parent (N)) = N_Subprogram_Renaming_Declaration
4020 if Find_Primitive_Operation (N) then
4024 elsif Try_Object_Operation (N) then
4028 -- If the transformation fails, it will be necessary to redo the
4029 -- analysis with all errors enabled, to indicate candidate
4030 -- interpretations and reasons for each failure ???
4034 elsif Is_Private_Type (Prefix_Type) then
4036 -- Allow access only to discriminants of the type. If the type has
4037 -- no full view, gigi uses the parent type for the components, so we
4038 -- do the same here.
4040 if No (Full_View (Prefix_Type)) then
4041 Type_To_Use := Root_Type (Base_Type (Prefix_Type));
4042 Comp := First_Entity (Type_To_Use);
4045 while Present (Comp) loop
4046 if Chars (Comp) = Chars (Sel) then
4047 if Ekind (Comp) = E_Discriminant then
4048 Set_Entity_With_Style_Check (Sel, Comp);
4049 Generate_Reference (Comp, Sel);
4051 Set_Etype (Sel, Etype (Comp));
4052 Set_Etype (N, Etype (Comp));
4053 Check_Implicit_Dereference (N, Etype (N));
4055 if Is_Generic_Type (Prefix_Type)
4056 or else Is_Generic_Type (Root_Type (Prefix_Type))
4058 Set_Original_Discriminant (Sel, Comp);
4061 -- Before declaring an error, check whether this is tagged
4062 -- private type and a call to a primitive operation.
4064 elsif Ada_Version >= Ada_2005
4065 and then Is_Tagged_Type (Prefix_Type)
4066 and then Try_Object_Operation (N)
4071 Error_Msg_Node_2 := First_Subtype (Prefix_Type);
4072 Error_Msg_NE ("invisible selector& for }", N, Sel);
4073 Set_Entity (Sel, Any_Id);
4074 Set_Etype (N, Any_Type);
4083 elsif Is_Concurrent_Type (Prefix_Type) then
4085 -- Find visible operation with given name. For a protected type,
4086 -- the possible candidates are discriminants, entries or protected
4087 -- procedures. For a task type, the set can only include entries or
4088 -- discriminants if the task type is not an enclosing scope. If it
4089 -- is an enclosing scope (e.g. in an inner task) then all entities
4090 -- are visible, but the prefix must denote the enclosing scope, i.e.
4091 -- can only be a direct name or an expanded name.
4093 Set_Etype (Sel, Any_Type);
4094 In_Scope := In_Open_Scopes (Prefix_Type);
4096 while Present (Comp) loop
4097 if Chars (Comp) = Chars (Sel) then
4098 if Is_Overloadable (Comp) then
4099 Add_One_Interp (Sel, Comp, Etype (Comp));
4101 -- If the prefix is tagged, the correct interpretation may
4102 -- lie in the primitive or class-wide operations of the
4103 -- type. Perform a simple conformance check to determine
4104 -- whether Try_Object_Operation should be invoked even if
4105 -- a visible entity is found.
4107 if Is_Tagged_Type (Prefix_Type)
4109 Nkind_In (Parent (N), N_Procedure_Call_Statement,
4111 N_Indexed_Component)
4112 and then Has_Mode_Conformant_Spec (Comp)
4114 Has_Candidate := True;
4117 -- Note: a selected component may not denote a component of a
4118 -- protected type (4.1.3(7)).
4120 elsif Ekind_In (Comp, E_Discriminant, E_Entry_Family)
4122 and then not Is_Protected_Type (Prefix_Type)
4123 and then Is_Entity_Name (Name))
4125 Set_Entity_With_Style_Check (Sel, Comp);
4126 Generate_Reference (Comp, Sel);
4128 -- The selector is not overloadable, so we have a candidate
4131 Has_Candidate := True;
4137 Set_Etype (Sel, Etype (Comp));
4138 Set_Etype (N, Etype (Comp));
4140 if Ekind (Comp) = E_Discriminant then
4141 Set_Original_Discriminant (Sel, Comp);
4144 -- For access type case, introduce explicit dereference for
4145 -- more uniform treatment of entry calls.
4147 if Is_Access_Type (Etype (Name)) then
4148 Insert_Explicit_Dereference (Name);
4150 (Warn_On_Dereference, "?implicit dereference", N);
4156 exit when not In_Scope
4158 Comp = First_Private_Entity (Base_Type (Prefix_Type));
4161 -- If there is no visible entity with the given name or none of the
4162 -- visible entities are plausible interpretations, check whether
4163 -- there is some other primitive operation with that name.
4165 if Ada_Version >= Ada_2005
4166 and then Is_Tagged_Type (Prefix_Type)
4168 if (Etype (N) = Any_Type
4169 or else not Has_Candidate)
4170 and then Try_Object_Operation (N)
4174 -- If the context is not syntactically a procedure call, it
4175 -- may be a call to a primitive function declared outside of
4176 -- the synchronized type.
4178 -- If the context is a procedure call, there might still be
4179 -- an overloading between an entry and a primitive procedure
4180 -- declared outside of the synchronized type, called in prefix
4181 -- notation. This is harder to disambiguate because in one case
4182 -- the controlling formal is implicit ???
4184 elsif Nkind (Parent (N)) /= N_Procedure_Call_Statement
4185 and then Nkind (Parent (N)) /= N_Indexed_Component
4186 and then Try_Object_Operation (N)
4191 -- Ada 2012 (AI05-0090-1): If we found a candidate of a call to an
4192 -- entry or procedure of a tagged concurrent type we must check
4193 -- if there are class-wide subprograms covering the primitive. If
4194 -- true then Try_Object_Operation reports the error.
4197 and then Is_Concurrent_Type (Prefix_Type)
4198 and then Nkind (Parent (N)) = N_Procedure_Call_Statement
4200 -- Duplicate the call. This is required to avoid problems with
4201 -- the tree transformations performed by Try_Object_Operation.
4204 Try_Object_Operation
4205 (N => Sinfo.Name (New_Copy_Tree (Parent (N))),
4206 CW_Test_Only => True)
4212 if Etype (N) = Any_Type and then Is_Protected_Type (Prefix_Type) then
4214 -- Case of a prefix of a protected type: selector might denote
4215 -- an invisible private component.
4217 Comp := First_Private_Entity (Base_Type (Prefix_Type));
4218 while Present (Comp) and then Chars (Comp) /= Chars (Sel) loop
4222 if Present (Comp) then
4223 if Is_Single_Concurrent_Object then
4224 Error_Msg_Node_2 := Entity (Name);
4225 Error_Msg_NE ("invisible selector& for &", N, Sel);
4228 Error_Msg_Node_2 := First_Subtype (Prefix_Type);
4229 Error_Msg_NE ("invisible selector& for }", N, Sel);
4235 Set_Is_Overloaded (N, Is_Overloaded (Sel));
4240 Error_Msg_NE ("invalid prefix in selected component&", N, Sel);
4243 -- If N still has no type, the component is not defined in the prefix
4245 if Etype (N) = Any_Type then
4247 if Is_Single_Concurrent_Object then
4248 Error_Msg_Node_2 := Entity (Name);
4249 Error_Msg_NE ("no selector& for&", N, Sel);
4251 Check_Misspelled_Selector (Type_To_Use, Sel);
4253 elsif Is_Generic_Type (Prefix_Type)
4254 and then Ekind (Prefix_Type) = E_Record_Type_With_Private
4255 and then Prefix_Type /= Etype (Prefix_Type)
4256 and then Is_Record_Type (Etype (Prefix_Type))
4258 -- If this is a derived formal type, the parent may have
4259 -- different visibility at this point. Try for an inherited
4260 -- component before reporting an error.
4262 Set_Etype (Prefix (N), Etype (Prefix_Type));
4263 Analyze_Selected_Component (N);
4266 -- Similarly, if this is the actual for a formal derived type, the
4267 -- component inherited from the generic parent may not be visible
4268 -- in the actual, but the selected component is legal.
4270 elsif Ekind (Prefix_Type) = E_Record_Subtype_With_Private
4271 and then Is_Generic_Actual_Type (Prefix_Type)
4272 and then Present (Full_View (Prefix_Type))
4275 Find_Component_In_Instance
4276 (Generic_Parent_Type (Parent (Prefix_Type)));
4279 -- Finally, the formal and the actual may be private extensions,
4280 -- but the generic is declared in a child unit of the parent, and
4281 -- an additional step is needed to retrieve the proper scope.
4284 and then Present (Parent_Subtype (Etype (Base_Type (Prefix_Type))))
4286 Find_Component_In_Instance
4287 (Parent_Subtype (Etype (Base_Type (Prefix_Type))));
4290 -- Component not found, specialize error message when appropriate
4293 if Ekind (Prefix_Type) = E_Record_Subtype then
4295 -- Check whether this is a component of the base type which
4296 -- is absent from a statically constrained subtype. This will
4297 -- raise constraint error at run time, but is not a compile-
4298 -- time error. When the selector is illegal for base type as
4299 -- well fall through and generate a compilation error anyway.
4301 Comp := First_Component (Base_Type (Prefix_Type));
4302 while Present (Comp) loop
4303 if Chars (Comp) = Chars (Sel)
4304 and then Is_Visible_Component (Comp)
4306 Set_Entity_With_Style_Check (Sel, Comp);
4307 Generate_Reference (Comp, Sel);
4308 Set_Etype (Sel, Etype (Comp));
4309 Set_Etype (N, Etype (Comp));
4311 -- Emit appropriate message. Gigi will replace the
4312 -- node subsequently with the appropriate Raise.
4314 Apply_Compile_Time_Constraint_Error
4315 (N, "component not present in }?",
4316 CE_Discriminant_Check_Failed,
4317 Ent => Prefix_Type, Rep => False);
4318 Set_Raises_Constraint_Error (N);
4322 Next_Component (Comp);
4327 Error_Msg_Node_2 := First_Subtype (Prefix_Type);
4328 Error_Msg_NE ("no selector& for}", N, Sel);
4330 -- Add information in the case of an incomplete prefix
4332 if Is_Incomplete_Type (Type_To_Use) then
4334 Inc : constant Entity_Id := First_Subtype (Type_To_Use);
4337 if From_With_Type (Scope (Type_To_Use)) then
4339 ("\limited view of& has no components", N, Inc);
4343 ("\premature usage of incomplete type&", N, Inc);
4345 if Nkind (Parent (Inc)) =
4346 N_Incomplete_Type_Declaration
4348 -- Record location of premature use in entity so that
4349 -- a continuation message is generated when the
4350 -- completion is seen.
4352 Set_Premature_Use (Parent (Inc), N);
4358 Check_Misspelled_Selector (Type_To_Use, Sel);
4361 Set_Entity (Sel, Any_Id);
4362 Set_Etype (Sel, Any_Type);
4364 end Analyze_Selected_Component;
4366 ---------------------------
4367 -- Analyze_Short_Circuit --
4368 ---------------------------
4370 procedure Analyze_Short_Circuit (N : Node_Id) is
4371 L : constant Node_Id := Left_Opnd (N);
4372 R : constant Node_Id := Right_Opnd (N);
4377 Analyze_Expression (L);
4378 Analyze_Expression (R);
4379 Set_Etype (N, Any_Type);
4381 if not Is_Overloaded (L) then
4382 if Root_Type (Etype (L)) = Standard_Boolean
4383 and then Has_Compatible_Type (R, Etype (L))
4385 Add_One_Interp (N, Etype (L), Etype (L));
4389 Get_First_Interp (L, Ind, It);
4390 while Present (It.Typ) loop
4391 if Root_Type (It.Typ) = Standard_Boolean
4392 and then Has_Compatible_Type (R, It.Typ)
4394 Add_One_Interp (N, It.Typ, It.Typ);
4397 Get_Next_Interp (Ind, It);
4401 -- Here we have failed to find an interpretation. Clearly we know that
4402 -- it is not the case that both operands can have an interpretation of
4403 -- Boolean, but this is by far the most likely intended interpretation.
4404 -- So we simply resolve both operands as Booleans, and at least one of
4405 -- these resolutions will generate an error message, and we do not need
4406 -- to give another error message on the short circuit operation itself.
4408 if Etype (N) = Any_Type then
4409 Resolve (L, Standard_Boolean);
4410 Resolve (R, Standard_Boolean);
4411 Set_Etype (N, Standard_Boolean);
4413 end Analyze_Short_Circuit;
4419 procedure Analyze_Slice (N : Node_Id) is
4420 P : constant Node_Id := Prefix (N);
4421 D : constant Node_Id := Discrete_Range (N);
4422 Array_Type : Entity_Id;
4424 procedure Analyze_Overloaded_Slice;
4425 -- If the prefix is overloaded, select those interpretations that
4426 -- yield a one-dimensional array type.
4428 ------------------------------
4429 -- Analyze_Overloaded_Slice --
4430 ------------------------------
4432 procedure Analyze_Overloaded_Slice is
4438 Set_Etype (N, Any_Type);
4440 Get_First_Interp (P, I, It);
4441 while Present (It.Nam) loop
4444 if Is_Access_Type (Typ) then
4445 Typ := Designated_Type (Typ);
4446 Error_Msg_NW (Warn_On_Dereference, "?implicit dereference", N);
4449 if Is_Array_Type (Typ)
4450 and then Number_Dimensions (Typ) = 1
4451 and then Has_Compatible_Type (D, Etype (First_Index (Typ)))
4453 Add_One_Interp (N, Typ, Typ);
4456 Get_Next_Interp (I, It);
4459 if Etype (N) = Any_Type then
4460 Error_Msg_N ("expect array type in prefix of slice", N);
4462 end Analyze_Overloaded_Slice;
4464 -- Start of processing for Analyze_Slice
4467 if Comes_From_Source (N) then
4468 Check_SPARK_Restriction ("slice is not allowed", N);
4474 if Is_Overloaded (P) then
4475 Analyze_Overloaded_Slice;
4478 Array_Type := Etype (P);
4479 Set_Etype (N, Any_Type);
4481 if Is_Access_Type (Array_Type) then
4482 Array_Type := Designated_Type (Array_Type);
4483 Error_Msg_NW (Warn_On_Dereference, "?implicit dereference", N);
4486 if not Is_Array_Type (Array_Type) then
4487 Wrong_Type (P, Any_Array);
4489 elsif Number_Dimensions (Array_Type) > 1 then
4491 ("type is not one-dimensional array in slice prefix", N);
4494 Has_Compatible_Type (D, Etype (First_Index (Array_Type)))
4496 Wrong_Type (D, Etype (First_Index (Array_Type)));
4499 Set_Etype (N, Array_Type);
4504 -----------------------------
4505 -- Analyze_Type_Conversion --
4506 -----------------------------
4508 procedure Analyze_Type_Conversion (N : Node_Id) is
4509 Expr : constant Node_Id := Expression (N);
4513 -- If Conversion_OK is set, then the Etype is already set, and the
4514 -- only processing required is to analyze the expression. This is
4515 -- used to construct certain "illegal" conversions which are not
4516 -- allowed by Ada semantics, but can be handled OK by Gigi, see
4517 -- Sinfo for further details.
4519 if Conversion_OK (N) then
4524 -- Otherwise full type analysis is required, as well as some semantic
4525 -- checks to make sure the argument of the conversion is appropriate.
4527 Find_Type (Subtype_Mark (N));
4528 T := Entity (Subtype_Mark (N));
4530 Check_Fully_Declared (T, N);
4531 Analyze_Expression (Expr);
4532 Validate_Remote_Type_Type_Conversion (N);
4534 -- Only remaining step is validity checks on the argument. These
4535 -- are skipped if the conversion does not come from the source.
4537 if not Comes_From_Source (N) then
4540 -- If there was an error in a generic unit, no need to replicate the
4541 -- error message. Conversely, constant-folding in the generic may
4542 -- transform the argument of a conversion into a string literal, which
4543 -- is legal. Therefore the following tests are not performed in an
4546 elsif In_Instance then
4549 elsif Nkind (Expr) = N_Null then
4550 Error_Msg_N ("argument of conversion cannot be null", N);
4551 Error_Msg_N ("\use qualified expression instead", N);
4552 Set_Etype (N, Any_Type);
4554 elsif Nkind (Expr) = N_Aggregate then
4555 Error_Msg_N ("argument of conversion cannot be aggregate", N);
4556 Error_Msg_N ("\use qualified expression instead", N);
4558 elsif Nkind (Expr) = N_Allocator then
4559 Error_Msg_N ("argument of conversion cannot be an allocator", N);
4560 Error_Msg_N ("\use qualified expression instead", N);
4562 elsif Nkind (Expr) = N_String_Literal then
4563 Error_Msg_N ("argument of conversion cannot be string literal", N);
4564 Error_Msg_N ("\use qualified expression instead", N);
4566 elsif Nkind (Expr) = N_Character_Literal then
4567 if Ada_Version = Ada_83 then
4570 Error_Msg_N ("argument of conversion cannot be character literal",
4572 Error_Msg_N ("\use qualified expression instead", N);
4575 elsif Nkind (Expr) = N_Attribute_Reference
4577 (Attribute_Name (Expr) = Name_Access or else
4578 Attribute_Name (Expr) = Name_Unchecked_Access or else
4579 Attribute_Name (Expr) = Name_Unrestricted_Access)
4581 Error_Msg_N ("argument of conversion cannot be access", N);
4582 Error_Msg_N ("\use qualified expression instead", N);
4584 end Analyze_Type_Conversion;
4586 ----------------------
4587 -- Analyze_Unary_Op --
4588 ----------------------
4590 procedure Analyze_Unary_Op (N : Node_Id) is
4591 R : constant Node_Id := Right_Opnd (N);
4592 Op_Id : Entity_Id := Entity (N);
4595 Set_Etype (N, Any_Type);
4596 Candidate_Type := Empty;
4598 Analyze_Expression (R);
4600 if Present (Op_Id) then
4601 if Ekind (Op_Id) = E_Operator then
4602 Find_Unary_Types (R, Op_Id, N);
4604 Add_One_Interp (N, Op_Id, Etype (Op_Id));
4608 Op_Id := Get_Name_Entity_Id (Chars (N));
4609 while Present (Op_Id) loop
4610 if Ekind (Op_Id) = E_Operator then
4611 if No (Next_Entity (First_Entity (Op_Id))) then
4612 Find_Unary_Types (R, Op_Id, N);
4615 elsif Is_Overloadable (Op_Id) then
4616 Analyze_User_Defined_Unary_Op (N, Op_Id);
4619 Op_Id := Homonym (Op_Id);
4624 end Analyze_Unary_Op;
4626 ----------------------------------
4627 -- Analyze_Unchecked_Expression --
4628 ----------------------------------
4630 procedure Analyze_Unchecked_Expression (N : Node_Id) is
4632 Analyze (Expression (N), Suppress => All_Checks);
4633 Set_Etype (N, Etype (Expression (N)));
4634 Save_Interps (Expression (N), N);
4635 end Analyze_Unchecked_Expression;
4637 ---------------------------------------
4638 -- Analyze_Unchecked_Type_Conversion --
4639 ---------------------------------------
4641 procedure Analyze_Unchecked_Type_Conversion (N : Node_Id) is
4643 Find_Type (Subtype_Mark (N));
4644 Analyze_Expression (Expression (N));
4645 Set_Etype (N, Entity (Subtype_Mark (N)));
4646 end Analyze_Unchecked_Type_Conversion;
4648 ------------------------------------
4649 -- Analyze_User_Defined_Binary_Op --
4650 ------------------------------------
4652 procedure Analyze_User_Defined_Binary_Op
4657 -- Only do analysis if the operator Comes_From_Source, since otherwise
4658 -- the operator was generated by the expander, and all such operators
4659 -- always refer to the operators in package Standard.
4661 if Comes_From_Source (N) then
4663 F1 : constant Entity_Id := First_Formal (Op_Id);
4664 F2 : constant Entity_Id := Next_Formal (F1);
4667 -- Verify that Op_Id is a visible binary function. Note that since
4668 -- we know Op_Id is overloaded, potentially use visible means use
4669 -- visible for sure (RM 9.4(11)).
4671 if Ekind (Op_Id) = E_Function
4672 and then Present (F2)
4673 and then (Is_Immediately_Visible (Op_Id)
4674 or else Is_Potentially_Use_Visible (Op_Id))
4675 and then Has_Compatible_Type (Left_Opnd (N), Etype (F1))
4676 and then Has_Compatible_Type (Right_Opnd (N), Etype (F2))
4678 Add_One_Interp (N, Op_Id, Etype (Op_Id));
4680 -- If the left operand is overloaded, indicate that the
4681 -- current type is a viable candidate. This is redundant
4682 -- in most cases, but for equality and comparison operators
4683 -- where the context does not impose a type on the operands,
4684 -- setting the proper type is necessary to avoid subsequent
4685 -- ambiguities during resolution, when both user-defined and
4686 -- predefined operators may be candidates.
4688 if Is_Overloaded (Left_Opnd (N)) then
4689 Set_Etype (Left_Opnd (N), Etype (F1));
4692 if Debug_Flag_E then
4693 Write_Str ("user defined operator ");
4694 Write_Name (Chars (Op_Id));
4695 Write_Str (" on node ");
4696 Write_Int (Int (N));
4702 end Analyze_User_Defined_Binary_Op;
4704 -----------------------------------
4705 -- Analyze_User_Defined_Unary_Op --
4706 -----------------------------------
4708 procedure Analyze_User_Defined_Unary_Op
4713 -- Only do analysis if the operator Comes_From_Source, since otherwise
4714 -- the operator was generated by the expander, and all such operators
4715 -- always refer to the operators in package Standard.
4717 if Comes_From_Source (N) then
4719 F : constant Entity_Id := First_Formal (Op_Id);
4722 -- Verify that Op_Id is a visible unary function. Note that since
4723 -- we know Op_Id is overloaded, potentially use visible means use
4724 -- visible for sure (RM 9.4(11)).
4726 if Ekind (Op_Id) = E_Function
4727 and then No (Next_Formal (F))
4728 and then (Is_Immediately_Visible (Op_Id)
4729 or else Is_Potentially_Use_Visible (Op_Id))
4730 and then Has_Compatible_Type (Right_Opnd (N), Etype (F))
4732 Add_One_Interp (N, Op_Id, Etype (Op_Id));
4736 end Analyze_User_Defined_Unary_Op;
4738 ---------------------------
4739 -- Check_Arithmetic_Pair --
4740 ---------------------------
4742 procedure Check_Arithmetic_Pair
4743 (T1, T2 : Entity_Id;
4747 Op_Name : constant Name_Id := Chars (Op_Id);
4749 function Has_Fixed_Op (Typ : Entity_Id; Op : Entity_Id) return Boolean;
4750 -- Check whether the fixed-point type Typ has a user-defined operator
4751 -- (multiplication or division) that should hide the corresponding
4752 -- predefined operator. Used to implement Ada 2005 AI-264, to make
4753 -- such operators more visible and therefore useful.
4755 -- If the name of the operation is an expanded name with prefix
4756 -- Standard, the predefined universal fixed operator is available,
4757 -- as specified by AI-420 (RM 4.5.5 (19.1/2)).
4759 function Specific_Type (T1, T2 : Entity_Id) return Entity_Id;
4760 -- Get specific type (i.e. non-universal type if there is one)
4766 function Has_Fixed_Op (Typ : Entity_Id; Op : Entity_Id) return Boolean is
4767 Bas : constant Entity_Id := Base_Type (Typ);
4773 -- If the universal_fixed operation is given explicitly the rule
4774 -- concerning primitive operations of the type do not apply.
4776 if Nkind (N) = N_Function_Call
4777 and then Nkind (Name (N)) = N_Expanded_Name
4778 and then Entity (Prefix (Name (N))) = Standard_Standard
4783 -- The operation is treated as primitive if it is declared in the
4784 -- same scope as the type, and therefore on the same entity chain.
4786 Ent := Next_Entity (Typ);
4787 while Present (Ent) loop
4788 if Chars (Ent) = Chars (Op) then
4789 F1 := First_Formal (Ent);
4790 F2 := Next_Formal (F1);
4792 -- The operation counts as primitive if either operand or
4793 -- result are of the given base type, and both operands are
4794 -- fixed point types.
4796 if (Base_Type (Etype (F1)) = Bas
4797 and then Is_Fixed_Point_Type (Etype (F2)))
4800 (Base_Type (Etype (F2)) = Bas
4801 and then Is_Fixed_Point_Type (Etype (F1)))
4804 (Base_Type (Etype (Ent)) = Bas
4805 and then Is_Fixed_Point_Type (Etype (F1))
4806 and then Is_Fixed_Point_Type (Etype (F2)))
4822 function Specific_Type (T1, T2 : Entity_Id) return Entity_Id is
4824 if T1 = Universal_Integer or else T1 = Universal_Real then
4825 return Base_Type (T2);
4827 return Base_Type (T1);
4831 -- Start of processing for Check_Arithmetic_Pair
4834 if Op_Name = Name_Op_Add or else Op_Name = Name_Op_Subtract then
4836 if Is_Numeric_Type (T1)
4837 and then Is_Numeric_Type (T2)
4838 and then (Covers (T1 => T1, T2 => T2)
4840 Covers (T1 => T2, T2 => T1))
4842 Add_One_Interp (N, Op_Id, Specific_Type (T1, T2));
4845 elsif Op_Name = Name_Op_Multiply or else Op_Name = Name_Op_Divide then
4847 if Is_Fixed_Point_Type (T1)
4848 and then (Is_Fixed_Point_Type (T2)
4849 or else T2 = Universal_Real)
4851 -- If Treat_Fixed_As_Integer is set then the Etype is already set
4852 -- and no further processing is required (this is the case of an
4853 -- operator constructed by Exp_Fixd for a fixed point operation)
4854 -- Otherwise add one interpretation with universal fixed result
4855 -- If the operator is given in functional notation, it comes
4856 -- from source and Fixed_As_Integer cannot apply.
4858 if (Nkind (N) not in N_Op
4859 or else not Treat_Fixed_As_Integer (N))
4861 (not Has_Fixed_Op (T1, Op_Id)
4862 or else Nkind (Parent (N)) = N_Type_Conversion)
4864 Add_One_Interp (N, Op_Id, Universal_Fixed);
4867 elsif Is_Fixed_Point_Type (T2)
4868 and then (Nkind (N) not in N_Op
4869 or else not Treat_Fixed_As_Integer (N))
4870 and then T1 = Universal_Real
4872 (not Has_Fixed_Op (T1, Op_Id)
4873 or else Nkind (Parent (N)) = N_Type_Conversion)
4875 Add_One_Interp (N, Op_Id, Universal_Fixed);
4877 elsif Is_Numeric_Type (T1)
4878 and then Is_Numeric_Type (T2)
4879 and then (Covers (T1 => T1, T2 => T2)
4881 Covers (T1 => T2, T2 => T1))
4883 Add_One_Interp (N, Op_Id, Specific_Type (T1, T2));
4885 elsif Is_Fixed_Point_Type (T1)
4886 and then (Base_Type (T2) = Base_Type (Standard_Integer)
4887 or else T2 = Universal_Integer)
4889 Add_One_Interp (N, Op_Id, T1);
4891 elsif T2 = Universal_Real
4892 and then Base_Type (T1) = Base_Type (Standard_Integer)
4893 and then Op_Name = Name_Op_Multiply
4895 Add_One_Interp (N, Op_Id, Any_Fixed);
4897 elsif T1 = Universal_Real
4898 and then Base_Type (T2) = Base_Type (Standard_Integer)
4900 Add_One_Interp (N, Op_Id, Any_Fixed);
4902 elsif Is_Fixed_Point_Type (T2)
4903 and then (Base_Type (T1) = Base_Type (Standard_Integer)
4904 or else T1 = Universal_Integer)
4905 and then Op_Name = Name_Op_Multiply
4907 Add_One_Interp (N, Op_Id, T2);
4909 elsif T1 = Universal_Real and then T2 = Universal_Integer then
4910 Add_One_Interp (N, Op_Id, T1);
4912 elsif T2 = Universal_Real
4913 and then T1 = Universal_Integer
4914 and then Op_Name = Name_Op_Multiply
4916 Add_One_Interp (N, Op_Id, T2);
4919 elsif Op_Name = Name_Op_Mod or else Op_Name = Name_Op_Rem then
4921 -- Note: The fixed-point operands case with Treat_Fixed_As_Integer
4922 -- set does not require any special processing, since the Etype is
4923 -- already set (case of operation constructed by Exp_Fixed).
4925 if Is_Integer_Type (T1)
4926 and then (Covers (T1 => T1, T2 => T2)
4928 Covers (T1 => T2, T2 => T1))
4930 Add_One_Interp (N, Op_Id, Specific_Type (T1, T2));
4933 elsif Op_Name = Name_Op_Expon then
4934 if Is_Numeric_Type (T1)
4935 and then not Is_Fixed_Point_Type (T1)
4936 and then (Base_Type (T2) = Base_Type (Standard_Integer)
4937 or else T2 = Universal_Integer)
4939 Add_One_Interp (N, Op_Id, Base_Type (T1));
4942 else pragma Assert (Nkind (N) in N_Op_Shift);
4944 -- If not one of the predefined operators, the node may be one
4945 -- of the intrinsic functions. Its kind is always specific, and
4946 -- we can use it directly, rather than the name of the operation.
4948 if Is_Integer_Type (T1)
4949 and then (Base_Type (T2) = Base_Type (Standard_Integer)
4950 or else T2 = Universal_Integer)
4952 Add_One_Interp (N, Op_Id, Base_Type (T1));
4955 end Check_Arithmetic_Pair;
4957 -------------------------------
4958 -- Check_Misspelled_Selector --
4959 -------------------------------
4961 procedure Check_Misspelled_Selector
4962 (Prefix : Entity_Id;
4965 Max_Suggestions : constant := 2;
4966 Nr_Of_Suggestions : Natural := 0;
4968 Suggestion_1 : Entity_Id := Empty;
4969 Suggestion_2 : Entity_Id := Empty;
4974 -- All the components of the prefix of selector Sel are matched
4975 -- against Sel and a count is maintained of possible misspellings.
4976 -- When at the end of the analysis there are one or two (not more!)
4977 -- possible misspellings, these misspellings will be suggested as
4978 -- possible correction.
4980 if not (Is_Private_Type (Prefix) or else Is_Record_Type (Prefix)) then
4982 -- Concurrent types should be handled as well ???
4987 Comp := First_Entity (Prefix);
4988 while Nr_Of_Suggestions <= Max_Suggestions and then Present (Comp) loop
4989 if Is_Visible_Component (Comp) then
4990 if Is_Bad_Spelling_Of (Chars (Comp), Chars (Sel)) then
4991 Nr_Of_Suggestions := Nr_Of_Suggestions + 1;
4993 case Nr_Of_Suggestions is
4994 when 1 => Suggestion_1 := Comp;
4995 when 2 => Suggestion_2 := Comp;
4996 when others => exit;
5001 Comp := Next_Entity (Comp);
5004 -- Report at most two suggestions
5006 if Nr_Of_Suggestions = 1 then
5007 Error_Msg_NE -- CODEFIX
5008 ("\possible misspelling of&", Sel, Suggestion_1);
5010 elsif Nr_Of_Suggestions = 2 then
5011 Error_Msg_Node_2 := Suggestion_2;
5012 Error_Msg_NE -- CODEFIX
5013 ("\possible misspelling of& or&", Sel, Suggestion_1);
5015 end Check_Misspelled_Selector;
5017 ----------------------
5018 -- Defined_In_Scope --
5019 ----------------------
5021 function Defined_In_Scope (T : Entity_Id; S : Entity_Id) return Boolean
5023 S1 : constant Entity_Id := Scope (Base_Type (T));
5026 or else (S1 = System_Aux_Id and then S = Scope (S1));
5027 end Defined_In_Scope;
5033 procedure Diagnose_Call (N : Node_Id; Nam : Node_Id) is
5039 Void_Interp_Seen : Boolean := False;
5042 pragma Warnings (Off, Boolean);
5045 if Ada_Version >= Ada_2005 then
5046 Actual := First_Actual (N);
5047 while Present (Actual) loop
5049 -- Ada 2005 (AI-50217): Post an error in case of premature
5050 -- usage of an entity from the limited view.
5052 if not Analyzed (Etype (Actual))
5053 and then From_With_Type (Etype (Actual))
5055 Error_Msg_Qual_Level := 1;
5057 ("missing with_clause for scope of imported type&",
5058 Actual, Etype (Actual));
5059 Error_Msg_Qual_Level := 0;
5062 Next_Actual (Actual);
5066 -- Analyze each candidate call again, with full error reporting
5070 ("no candidate interpretations match the actuals:!", Nam);
5071 Err_Mode := All_Errors_Mode;
5072 All_Errors_Mode := True;
5074 -- If this is a call to an operation of a concurrent type,
5075 -- the failed interpretations have been removed from the
5076 -- name. Recover them to provide full diagnostics.
5078 if Nkind (Parent (Nam)) = N_Selected_Component then
5079 Set_Entity (Nam, Empty);
5080 New_Nam := New_Copy_Tree (Parent (Nam));
5081 Set_Is_Overloaded (New_Nam, False);
5082 Set_Is_Overloaded (Selector_Name (New_Nam), False);
5083 Set_Parent (New_Nam, Parent (Parent (Nam)));
5084 Analyze_Selected_Component (New_Nam);
5085 Get_First_Interp (Selector_Name (New_Nam), X, It);
5087 Get_First_Interp (Nam, X, It);
5090 while Present (It.Nam) loop
5091 if Etype (It.Nam) = Standard_Void_Type then
5092 Void_Interp_Seen := True;
5095 Analyze_One_Call (N, It.Nam, True, Success);
5096 Get_Next_Interp (X, It);
5099 if Nkind (N) = N_Function_Call then
5100 Get_First_Interp (Nam, X, It);
5101 while Present (It.Nam) loop
5102 if Ekind_In (It.Nam, E_Function, E_Operator) then
5105 Get_Next_Interp (X, It);
5109 -- If all interpretations are procedures, this deserves a
5110 -- more precise message. Ditto if this appears as the prefix
5111 -- of a selected component, which may be a lexical error.
5114 ("\context requires function call, found procedure name", Nam);
5116 if Nkind (Parent (N)) = N_Selected_Component
5117 and then N = Prefix (Parent (N))
5119 Error_Msg_N -- CODEFIX
5120 ("\period should probably be semicolon", Parent (N));
5123 elsif Nkind (N) = N_Procedure_Call_Statement
5124 and then not Void_Interp_Seen
5127 "\function name found in procedure call", Nam);
5130 All_Errors_Mode := Err_Mode;
5133 ---------------------------
5134 -- Find_Arithmetic_Types --
5135 ---------------------------
5137 procedure Find_Arithmetic_Types
5142 Index1 : Interp_Index;
5143 Index2 : Interp_Index;
5147 procedure Check_Right_Argument (T : Entity_Id);
5148 -- Check right operand of operator
5150 --------------------------
5151 -- Check_Right_Argument --
5152 --------------------------
5154 procedure Check_Right_Argument (T : Entity_Id) is
5156 if not Is_Overloaded (R) then
5157 Check_Arithmetic_Pair (T, Etype (R), Op_Id, N);
5159 Get_First_Interp (R, Index2, It2);
5160 while Present (It2.Typ) loop
5161 Check_Arithmetic_Pair (T, It2.Typ, Op_Id, N);
5162 Get_Next_Interp (Index2, It2);
5165 end Check_Right_Argument;
5167 -- Start of processing for Find_Arithmetic_Types
5170 if not Is_Overloaded (L) then
5171 Check_Right_Argument (Etype (L));
5174 Get_First_Interp (L, Index1, It1);
5175 while Present (It1.Typ) loop
5176 Check_Right_Argument (It1.Typ);
5177 Get_Next_Interp (Index1, It1);
5181 end Find_Arithmetic_Types;
5183 ------------------------
5184 -- Find_Boolean_Types --
5185 ------------------------
5187 procedure Find_Boolean_Types
5192 Index : Interp_Index;
5195 procedure Check_Numeric_Argument (T : Entity_Id);
5196 -- Special case for logical operations one of whose operands is an
5197 -- integer literal. If both are literal the result is any modular type.
5199 ----------------------------
5200 -- Check_Numeric_Argument --
5201 ----------------------------
5203 procedure Check_Numeric_Argument (T : Entity_Id) is
5205 if T = Universal_Integer then
5206 Add_One_Interp (N, Op_Id, Any_Modular);
5208 elsif Is_Modular_Integer_Type (T) then
5209 Add_One_Interp (N, Op_Id, T);
5211 end Check_Numeric_Argument;
5213 -- Start of processing for Find_Boolean_Types
5216 if not Is_Overloaded (L) then
5217 if Etype (L) = Universal_Integer
5218 or else Etype (L) = Any_Modular
5220 if not Is_Overloaded (R) then
5221 Check_Numeric_Argument (Etype (R));
5224 Get_First_Interp (R, Index, It);
5225 while Present (It.Typ) loop
5226 Check_Numeric_Argument (It.Typ);
5227 Get_Next_Interp (Index, It);
5231 -- If operands are aggregates, we must assume that they may be
5232 -- boolean arrays, and leave disambiguation for the second pass.
5233 -- If only one is an aggregate, verify that the other one has an
5234 -- interpretation as a boolean array
5236 elsif Nkind (L) = N_Aggregate then
5237 if Nkind (R) = N_Aggregate then
5238 Add_One_Interp (N, Op_Id, Etype (L));
5240 elsif not Is_Overloaded (R) then
5241 if Valid_Boolean_Arg (Etype (R)) then
5242 Add_One_Interp (N, Op_Id, Etype (R));
5246 Get_First_Interp (R, Index, It);
5247 while Present (It.Typ) loop
5248 if Valid_Boolean_Arg (It.Typ) then
5249 Add_One_Interp (N, Op_Id, It.Typ);
5252 Get_Next_Interp (Index, It);
5256 elsif Valid_Boolean_Arg (Etype (L))
5257 and then Has_Compatible_Type (R, Etype (L))
5259 Add_One_Interp (N, Op_Id, Etype (L));
5263 Get_First_Interp (L, Index, It);
5264 while Present (It.Typ) loop
5265 if Valid_Boolean_Arg (It.Typ)
5266 and then Has_Compatible_Type (R, It.Typ)
5268 Add_One_Interp (N, Op_Id, It.Typ);
5271 Get_Next_Interp (Index, It);
5274 end Find_Boolean_Types;
5276 ---------------------------
5277 -- Find_Comparison_Types --
5278 ---------------------------
5280 procedure Find_Comparison_Types
5285 Index : Interp_Index;
5287 Found : Boolean := False;
5290 Scop : Entity_Id := Empty;
5292 procedure Try_One_Interp (T1 : Entity_Id);
5293 -- Routine to try one proposed interpretation. Note that the context
5294 -- of the operator plays no role in resolving the arguments, so that
5295 -- if there is more than one interpretation of the operands that is
5296 -- compatible with comparison, the operation is ambiguous.
5298 --------------------
5299 -- Try_One_Interp --
5300 --------------------
5302 procedure Try_One_Interp (T1 : Entity_Id) is
5305 -- If the operator is an expanded name, then the type of the operand
5306 -- must be defined in the corresponding scope. If the type is
5307 -- universal, the context will impose the correct type.
5310 and then not Defined_In_Scope (T1, Scop)
5311 and then T1 /= Universal_Integer
5312 and then T1 /= Universal_Real
5313 and then T1 /= Any_String
5314 and then T1 /= Any_Composite
5319 if Valid_Comparison_Arg (T1)
5320 and then Has_Compatible_Type (R, T1)
5323 and then Base_Type (T1) /= Base_Type (T_F)
5325 It := Disambiguate (L, I_F, Index, Any_Type);
5327 if It = No_Interp then
5328 Ambiguous_Operands (N);
5329 Set_Etype (L, Any_Type);
5343 Find_Non_Universal_Interpretations (N, R, Op_Id, T1);
5348 -- Start of processing for Find_Comparison_Types
5351 -- If left operand is aggregate, the right operand has to
5352 -- provide a usable type for it.
5354 if Nkind (L) = N_Aggregate
5355 and then Nkind (R) /= N_Aggregate
5357 Find_Comparison_Types (L => R, R => L, Op_Id => Op_Id, N => N);
5361 if Nkind (N) = N_Function_Call
5362 and then Nkind (Name (N)) = N_Expanded_Name
5364 Scop := Entity (Prefix (Name (N)));
5366 -- The prefix may be a package renaming, and the subsequent test
5367 -- requires the original package.
5369 if Ekind (Scop) = E_Package
5370 and then Present (Renamed_Entity (Scop))
5372 Scop := Renamed_Entity (Scop);
5373 Set_Entity (Prefix (Name (N)), Scop);
5377 if not Is_Overloaded (L) then
5378 Try_One_Interp (Etype (L));
5381 Get_First_Interp (L, Index, It);
5382 while Present (It.Typ) loop
5383 Try_One_Interp (It.Typ);
5384 Get_Next_Interp (Index, It);
5387 end Find_Comparison_Types;
5389 ----------------------------------------
5390 -- Find_Non_Universal_Interpretations --
5391 ----------------------------------------
5393 procedure Find_Non_Universal_Interpretations
5399 Index : Interp_Index;
5403 if T1 = Universal_Integer
5404 or else T1 = Universal_Real
5406 if not Is_Overloaded (R) then
5408 (N, Op_Id, Standard_Boolean, Base_Type (Etype (R)));
5410 Get_First_Interp (R, Index, It);
5411 while Present (It.Typ) loop
5412 if Covers (It.Typ, T1) then
5414 (N, Op_Id, Standard_Boolean, Base_Type (It.Typ));
5417 Get_Next_Interp (Index, It);
5421 Add_One_Interp (N, Op_Id, Standard_Boolean, Base_Type (T1));
5423 end Find_Non_Universal_Interpretations;
5425 ------------------------------
5426 -- Find_Concatenation_Types --
5427 ------------------------------
5429 procedure Find_Concatenation_Types
5434 Op_Type : constant Entity_Id := Etype (Op_Id);
5437 if Is_Array_Type (Op_Type)
5438 and then not Is_Limited_Type (Op_Type)
5440 and then (Has_Compatible_Type (L, Op_Type)
5442 Has_Compatible_Type (L, Component_Type (Op_Type)))
5444 and then (Has_Compatible_Type (R, Op_Type)
5446 Has_Compatible_Type (R, Component_Type (Op_Type)))
5448 Add_One_Interp (N, Op_Id, Op_Type);
5450 end Find_Concatenation_Types;
5452 -------------------------
5453 -- Find_Equality_Types --
5454 -------------------------
5456 procedure Find_Equality_Types
5461 Index : Interp_Index;
5463 Found : Boolean := False;
5466 Scop : Entity_Id := Empty;
5468 procedure Try_One_Interp (T1 : Entity_Id);
5469 -- The context of the equality operator plays no role in resolving the
5470 -- arguments, so that if there is more than one interpretation of the
5471 -- operands that is compatible with equality, the construct is ambiguous
5472 -- and an error can be emitted now, after trying to disambiguate, i.e.
5473 -- applying preference rules.
5475 --------------------
5476 -- Try_One_Interp --
5477 --------------------
5479 procedure Try_One_Interp (T1 : Entity_Id) is
5480 Bas : constant Entity_Id := Base_Type (T1);
5483 -- If the operator is an expanded name, then the type of the operand
5484 -- must be defined in the corresponding scope. If the type is
5485 -- universal, the context will impose the correct type. An anonymous
5486 -- type for a 'Access reference is also universal in this sense, as
5487 -- the actual type is obtained from context.
5488 -- In Ada 2005, the equality operator for anonymous access types
5489 -- is declared in Standard, and preference rules apply to it.
5491 if Present (Scop) then
5492 if Defined_In_Scope (T1, Scop)
5493 or else T1 = Universal_Integer
5494 or else T1 = Universal_Real
5495 or else T1 = Any_Access
5496 or else T1 = Any_String
5497 or else T1 = Any_Composite
5498 or else (Ekind (T1) = E_Access_Subprogram_Type
5499 and then not Comes_From_Source (T1))
5503 elsif Ekind (T1) = E_Anonymous_Access_Type
5504 and then Scop = Standard_Standard
5509 -- The scope does not contain an operator for the type
5514 -- If we have infix notation, the operator must be usable.
5515 -- Within an instance, if the type is already established we
5516 -- know it is correct.
5517 -- In Ada 2005, the equality on anonymous access types is declared
5518 -- in Standard, and is always visible.
5520 elsif In_Open_Scopes (Scope (Bas))
5521 or else Is_Potentially_Use_Visible (Bas)
5522 or else In_Use (Bas)
5523 or else (In_Use (Scope (Bas))
5524 and then not Is_Hidden (Bas))
5525 or else (In_Instance
5526 and then First_Subtype (T1) = First_Subtype (Etype (R)))
5527 or else Ekind (T1) = E_Anonymous_Access_Type
5532 -- Save candidate type for subsequent error message, if any
5534 if not Is_Limited_Type (T1) then
5535 Candidate_Type := T1;
5541 -- Ada 2005 (AI-230): Keep restriction imposed by Ada 83 and 95:
5542 -- Do not allow anonymous access types in equality operators.
5544 if Ada_Version < Ada_2005
5545 and then Ekind (T1) = E_Anonymous_Access_Type
5550 if T1 /= Standard_Void_Type
5551 and then Has_Compatible_Type (R, T1)
5553 ((not Is_Limited_Type (T1)
5554 and then not Is_Limited_Composite (T1))
5558 and then not Is_Limited_Type (Component_Type (T1))
5559 and then Available_Full_View_Of_Component (T1)))
5562 and then Base_Type (T1) /= Base_Type (T_F)
5564 It := Disambiguate (L, I_F, Index, Any_Type);
5566 if It = No_Interp then
5567 Ambiguous_Operands (N);
5568 Set_Etype (L, Any_Type);
5581 if not Analyzed (L) then
5585 Find_Non_Universal_Interpretations (N, R, Op_Id, T1);
5587 -- Case of operator was not visible, Etype still set to Any_Type
5589 if Etype (N) = Any_Type then
5593 elsif Scop = Standard_Standard
5594 and then Ekind (T1) = E_Anonymous_Access_Type
5600 -- Start of processing for Find_Equality_Types
5603 -- If left operand is aggregate, the right operand has to
5604 -- provide a usable type for it.
5606 if Nkind (L) = N_Aggregate
5607 and then Nkind (R) /= N_Aggregate
5609 Find_Equality_Types (L => R, R => L, Op_Id => Op_Id, N => N);
5613 if Nkind (N) = N_Function_Call
5614 and then Nkind (Name (N)) = N_Expanded_Name
5616 Scop := Entity (Prefix (Name (N)));
5618 -- The prefix may be a package renaming, and the subsequent test
5619 -- requires the original package.
5621 if Ekind (Scop) = E_Package
5622 and then Present (Renamed_Entity (Scop))
5624 Scop := Renamed_Entity (Scop);
5625 Set_Entity (Prefix (Name (N)), Scop);
5629 if not Is_Overloaded (L) then
5630 Try_One_Interp (Etype (L));
5633 Get_First_Interp (L, Index, It);
5634 while Present (It.Typ) loop
5635 Try_One_Interp (It.Typ);
5636 Get_Next_Interp (Index, It);
5639 end Find_Equality_Types;
5641 -------------------------
5642 -- Find_Negation_Types --
5643 -------------------------
5645 procedure Find_Negation_Types
5650 Index : Interp_Index;
5654 if not Is_Overloaded (R) then
5655 if Etype (R) = Universal_Integer then
5656 Add_One_Interp (N, Op_Id, Any_Modular);
5657 elsif Valid_Boolean_Arg (Etype (R)) then
5658 Add_One_Interp (N, Op_Id, Etype (R));
5662 Get_First_Interp (R, Index, It);
5663 while Present (It.Typ) loop
5664 if Valid_Boolean_Arg (It.Typ) then
5665 Add_One_Interp (N, Op_Id, It.Typ);
5668 Get_Next_Interp (Index, It);
5671 end Find_Negation_Types;
5673 ------------------------------
5674 -- Find_Primitive_Operation --
5675 ------------------------------
5677 function Find_Primitive_Operation (N : Node_Id) return Boolean is
5678 Obj : constant Node_Id := Prefix (N);
5679 Op : constant Node_Id := Selector_Name (N);
5686 Set_Etype (Op, Any_Type);
5688 if Is_Access_Type (Etype (Obj)) then
5689 Typ := Designated_Type (Etype (Obj));
5694 if Is_Class_Wide_Type (Typ) then
5695 Typ := Root_Type (Typ);
5698 Prims := Primitive_Operations (Typ);
5700 Prim := First_Elmt (Prims);
5701 while Present (Prim) loop
5702 if Chars (Node (Prim)) = Chars (Op) then
5703 Add_One_Interp (Op, Node (Prim), Etype (Node (Prim)));
5704 Set_Etype (N, Etype (Node (Prim)));
5710 -- Now look for class-wide operations of the type or any of its
5711 -- ancestors by iterating over the homonyms of the selector.
5714 Cls_Type : constant Entity_Id := Class_Wide_Type (Typ);
5718 Hom := Current_Entity (Op);
5719 while Present (Hom) loop
5720 if (Ekind (Hom) = E_Procedure
5722 Ekind (Hom) = E_Function)
5723 and then Scope (Hom) = Scope (Typ)
5724 and then Present (First_Formal (Hom))
5726 (Base_Type (Etype (First_Formal (Hom))) = Cls_Type
5728 (Is_Access_Type (Etype (First_Formal (Hom)))
5730 Ekind (Etype (First_Formal (Hom))) =
5731 E_Anonymous_Access_Type
5734 (Designated_Type (Etype (First_Formal (Hom)))) =
5737 Add_One_Interp (Op, Hom, Etype (Hom));
5738 Set_Etype (N, Etype (Hom));
5741 Hom := Homonym (Hom);
5745 return Etype (Op) /= Any_Type;
5746 end Find_Primitive_Operation;
5748 ----------------------
5749 -- Find_Unary_Types --
5750 ----------------------
5752 procedure Find_Unary_Types
5757 Index : Interp_Index;
5761 if not Is_Overloaded (R) then
5762 if Is_Numeric_Type (Etype (R)) then
5763 Add_One_Interp (N, Op_Id, Base_Type (Etype (R)));
5767 Get_First_Interp (R, Index, It);
5768 while Present (It.Typ) loop
5769 if Is_Numeric_Type (It.Typ) then
5770 Add_One_Interp (N, Op_Id, Base_Type (It.Typ));
5773 Get_Next_Interp (Index, It);
5776 end Find_Unary_Types;
5782 function Junk_Operand (N : Node_Id) return Boolean is
5786 if Error_Posted (N) then
5790 -- Get entity to be tested
5792 if Is_Entity_Name (N)
5793 and then Present (Entity (N))
5797 -- An odd case, a procedure name gets converted to a very peculiar
5798 -- function call, and here is where we detect this happening.
5800 elsif Nkind (N) = N_Function_Call
5801 and then Is_Entity_Name (Name (N))
5802 and then Present (Entity (Name (N)))
5806 -- Another odd case, there are at least some cases of selected
5807 -- components where the selected component is not marked as having
5808 -- an entity, even though the selector does have an entity
5810 elsif Nkind (N) = N_Selected_Component
5811 and then Present (Entity (Selector_Name (N)))
5813 Enode := Selector_Name (N);
5819 -- Now test the entity we got to see if it is a bad case
5821 case Ekind (Entity (Enode)) is
5825 ("package name cannot be used as operand", Enode);
5827 when Generic_Unit_Kind =>
5829 ("generic unit name cannot be used as operand", Enode);
5833 ("subtype name cannot be used as operand", Enode);
5837 ("entry name cannot be used as operand", Enode);
5841 ("procedure name cannot be used as operand", Enode);
5845 ("exception name cannot be used as operand", Enode);
5847 when E_Block | E_Label | E_Loop =>
5849 ("label name cannot be used as operand", Enode);
5859 --------------------
5860 -- Operator_Check --
5861 --------------------
5863 procedure Operator_Check (N : Node_Id) is
5865 Remove_Abstract_Operations (N);
5867 -- Test for case of no interpretation found for operator
5869 if Etype (N) = Any_Type then
5873 Op_Id : Entity_Id := Empty;
5876 R := Right_Opnd (N);
5878 if Nkind (N) in N_Binary_Op then
5884 -- If either operand has no type, then don't complain further,
5885 -- since this simply means that we have a propagated error.
5888 or else Etype (R) = Any_Type
5889 or else (Nkind (N) in N_Binary_Op and then Etype (L) = Any_Type)
5893 -- We explicitly check for the case of concatenation of component
5894 -- with component to avoid reporting spurious matching array types
5895 -- that might happen to be lurking in distant packages (such as
5896 -- run-time packages). This also prevents inconsistencies in the
5897 -- messages for certain ACVC B tests, which can vary depending on
5898 -- types declared in run-time interfaces. Another improvement when
5899 -- aggregates are present is to look for a well-typed operand.
5901 elsif Present (Candidate_Type)
5902 and then (Nkind (N) /= N_Op_Concat
5903 or else Is_Array_Type (Etype (L))
5904 or else Is_Array_Type (Etype (R)))
5906 if Nkind (N) = N_Op_Concat then
5907 if Etype (L) /= Any_Composite
5908 and then Is_Array_Type (Etype (L))
5910 Candidate_Type := Etype (L);
5912 elsif Etype (R) /= Any_Composite
5913 and then Is_Array_Type (Etype (R))
5915 Candidate_Type := Etype (R);
5919 Error_Msg_NE -- CODEFIX
5920 ("operator for} is not directly visible!",
5921 N, First_Subtype (Candidate_Type));
5924 U : constant Node_Id :=
5925 Cunit (Get_Source_Unit (Candidate_Type));
5927 if Unit_Is_Visible (U) then
5928 Error_Msg_N -- CODEFIX
5929 ("use clause would make operation legal!", N);
5931 Error_Msg_NE -- CODEFIX
5932 ("add with_clause and use_clause for&!",
5933 N, Defining_Entity (Unit (U)));
5938 -- If either operand is a junk operand (e.g. package name), then
5939 -- post appropriate error messages, but do not complain further.
5941 -- Note that the use of OR in this test instead of OR ELSE is
5942 -- quite deliberate, we may as well check both operands in the
5943 -- binary operator case.
5945 elsif Junk_Operand (R)
5946 or (Nkind (N) in N_Binary_Op and then Junk_Operand (L))
5950 -- If we have a logical operator, one of whose operands is
5951 -- Boolean, then we know that the other operand cannot resolve to
5952 -- Boolean (since we got no interpretations), but in that case we
5953 -- pretty much know that the other operand should be Boolean, so
5954 -- resolve it that way (generating an error)
5956 elsif Nkind_In (N, N_Op_And, N_Op_Or, N_Op_Xor) then
5957 if Etype (L) = Standard_Boolean then
5958 Resolve (R, Standard_Boolean);
5960 elsif Etype (R) = Standard_Boolean then
5961 Resolve (L, Standard_Boolean);
5965 -- For an arithmetic operator or comparison operator, if one
5966 -- of the operands is numeric, then we know the other operand
5967 -- is not the same numeric type. If it is a non-numeric type,
5968 -- then probably it is intended to match the other operand.
5970 elsif Nkind_In (N, N_Op_Add,
5976 Nkind_In (N, N_Op_Lt,
5982 if Is_Numeric_Type (Etype (L))
5983 and then not Is_Numeric_Type (Etype (R))
5985 Resolve (R, Etype (L));
5988 elsif Is_Numeric_Type (Etype (R))
5989 and then not Is_Numeric_Type (Etype (L))
5991 Resolve (L, Etype (R));
5995 -- Comparisons on A'Access are common enough to deserve a
5998 elsif Nkind_In (N, N_Op_Eq, N_Op_Ne)
5999 and then Ekind (Etype (L)) = E_Access_Attribute_Type
6000 and then Ekind (Etype (R)) = E_Access_Attribute_Type
6003 ("two access attributes cannot be compared directly", N);
6005 ("\use qualified expression for one of the operands",
6009 -- Another one for C programmers
6011 elsif Nkind (N) = N_Op_Concat
6012 and then Valid_Boolean_Arg (Etype (L))
6013 and then Valid_Boolean_Arg (Etype (R))
6015 Error_Msg_N ("invalid operands for concatenation", N);
6016 Error_Msg_N -- CODEFIX
6017 ("\maybe AND was meant", N);
6020 -- A special case for comparison of access parameter with null
6022 elsif Nkind (N) = N_Op_Eq
6023 and then Is_Entity_Name (L)
6024 and then Nkind (Parent (Entity (L))) = N_Parameter_Specification
6025 and then Nkind (Parameter_Type (Parent (Entity (L)))) =
6027 and then Nkind (R) = N_Null
6029 Error_Msg_N ("access parameter is not allowed to be null", L);
6030 Error_Msg_N ("\(call would raise Constraint_Error)", L);
6033 -- Another special case for exponentiation, where the right
6034 -- operand must be Natural, independently of the base.
6036 elsif Nkind (N) = N_Op_Expon
6037 and then Is_Numeric_Type (Etype (L))
6038 and then not Is_Overloaded (R)
6040 First_Subtype (Base_Type (Etype (R))) /= Standard_Integer
6041 and then Base_Type (Etype (R)) /= Universal_Integer
6044 ("exponent must be of type Natural, found}", R, Etype (R));
6048 -- If we fall through then just give general message. Note that in
6049 -- the following messages, if the operand is overloaded we choose
6050 -- an arbitrary type to complain about, but that is probably more
6051 -- useful than not giving a type at all.
6053 if Nkind (N) in N_Unary_Op then
6054 Error_Msg_Node_2 := Etype (R);
6055 Error_Msg_N ("operator& not defined for}", N);
6059 if Nkind (N) in N_Binary_Op then
6060 if not Is_Overloaded (L)
6061 and then not Is_Overloaded (R)
6062 and then Base_Type (Etype (L)) = Base_Type (Etype (R))
6064 Error_Msg_Node_2 := First_Subtype (Etype (R));
6065 Error_Msg_N ("there is no applicable operator& for}", N);
6068 -- Another attempt to find a fix: one of the candidate
6069 -- interpretations may not be use-visible. This has
6070 -- already been checked for predefined operators, so
6071 -- we examine only user-defined functions.
6073 Op_Id := Get_Name_Entity_Id (Chars (N));
6075 while Present (Op_Id) loop
6076 if Ekind (Op_Id) /= E_Operator
6077 and then Is_Overloadable (Op_Id)
6079 if not Is_Immediately_Visible (Op_Id)
6080 and then not In_Use (Scope (Op_Id))
6081 and then not Is_Abstract_Subprogram (Op_Id)
6082 and then not Is_Hidden (Op_Id)
6083 and then Ekind (Scope (Op_Id)) = E_Package
6086 (L, Etype (First_Formal (Op_Id)))
6088 (Next_Formal (First_Formal (Op_Id)))
6092 Etype (Next_Formal (First_Formal (Op_Id))))
6095 ("No legal interpretation for operator&", N);
6097 ("\use clause on& would make operation legal",
6103 Op_Id := Homonym (Op_Id);
6107 Error_Msg_N ("invalid operand types for operator&", N);
6109 if Nkind (N) /= N_Op_Concat then
6110 Error_Msg_NE ("\left operand has}!", N, Etype (L));
6111 Error_Msg_NE ("\right operand has}!", N, Etype (R));
6121 -----------------------------------------
6122 -- Process_Implicit_Dereference_Prefix --
6123 -----------------------------------------
6125 function Process_Implicit_Dereference_Prefix
6127 P : Entity_Id) return Entity_Id
6130 Typ : constant Entity_Id := Designated_Type (Etype (P));
6134 and then (Operating_Mode = Check_Semantics or else not Expander_Active)
6136 -- We create a dummy reference to E to ensure that the reference
6137 -- is not considered as part of an assignment (an implicit
6138 -- dereference can never assign to its prefix). The Comes_From_Source
6139 -- attribute needs to be propagated for accurate warnings.
6141 Ref := New_Reference_To (E, Sloc (P));
6142 Set_Comes_From_Source (Ref, Comes_From_Source (P));
6143 Generate_Reference (E, Ref);
6146 -- An implicit dereference is a legal occurrence of an
6147 -- incomplete type imported through a limited_with clause,
6148 -- if the full view is visible.
6150 if From_With_Type (Typ)
6151 and then not From_With_Type (Scope (Typ))
6153 (Is_Immediately_Visible (Scope (Typ))
6155 (Is_Child_Unit (Scope (Typ))
6156 and then Is_Visible_Child_Unit (Scope (Typ))))
6158 return Available_View (Typ);
6163 end Process_Implicit_Dereference_Prefix;
6165 --------------------------------
6166 -- Remove_Abstract_Operations --
6167 --------------------------------
6169 procedure Remove_Abstract_Operations (N : Node_Id) is
6170 Abstract_Op : Entity_Id := Empty;
6171 Address_Kludge : Boolean := False;
6175 -- AI-310: If overloaded, remove abstract non-dispatching operations. We
6176 -- activate this if either extensions are enabled, or if the abstract
6177 -- operation in question comes from a predefined file. This latter test
6178 -- allows us to use abstract to make operations invisible to users. In
6179 -- particular, if type Address is non-private and abstract subprograms
6180 -- are used to hide its operators, they will be truly hidden.
6182 type Operand_Position is (First_Op, Second_Op);
6183 Univ_Type : constant Entity_Id := Universal_Interpretation (N);
6185 procedure Remove_Address_Interpretations (Op : Operand_Position);
6186 -- Ambiguities may arise when the operands are literal and the address
6187 -- operations in s-auxdec are visible. In that case, remove the
6188 -- interpretation of a literal as Address, to retain the semantics of
6189 -- Address as a private type.
6191 ------------------------------------
6192 -- Remove_Address_Interpretations --
6193 ------------------------------------
6195 procedure Remove_Address_Interpretations (Op : Operand_Position) is
6199 if Is_Overloaded (N) then
6200 Get_First_Interp (N, I, It);
6201 while Present (It.Nam) loop
6202 Formal := First_Entity (It.Nam);
6204 if Op = Second_Op then
6205 Formal := Next_Entity (Formal);
6208 if Is_Descendent_Of_Address (Etype (Formal)) then
6209 Address_Kludge := True;
6213 Get_Next_Interp (I, It);
6216 end Remove_Address_Interpretations;
6218 -- Start of processing for Remove_Abstract_Operations
6221 if Is_Overloaded (N) then
6222 Get_First_Interp (N, I, It);
6224 while Present (It.Nam) loop
6225 if Is_Overloadable (It.Nam)
6226 and then Is_Abstract_Subprogram (It.Nam)
6227 and then not Is_Dispatching_Operation (It.Nam)
6229 Abstract_Op := It.Nam;
6231 if Is_Descendent_Of_Address (It.Typ) then
6232 Address_Kludge := True;
6236 -- In Ada 2005, this operation does not participate in Overload
6237 -- resolution. If the operation is defined in a predefined
6238 -- unit, it is one of the operations declared abstract in some
6239 -- variants of System, and it must be removed as well.
6241 elsif Ada_Version >= Ada_2005
6242 or else Is_Predefined_File_Name
6243 (Unit_File_Name (Get_Source_Unit (It.Nam)))
6250 Get_Next_Interp (I, It);
6253 if No (Abstract_Op) then
6255 -- If some interpretation yields an integer type, it is still
6256 -- possible that there are address interpretations. Remove them
6257 -- if one operand is a literal, to avoid spurious ambiguities
6258 -- on systems where Address is a visible integer type.
6260 if Is_Overloaded (N)
6261 and then Nkind (N) in N_Op
6262 and then Is_Integer_Type (Etype (N))
6264 if Nkind (N) in N_Binary_Op then
6265 if Nkind (Right_Opnd (N)) = N_Integer_Literal then
6266 Remove_Address_Interpretations (Second_Op);
6268 elsif Nkind (Right_Opnd (N)) = N_Integer_Literal then
6269 Remove_Address_Interpretations (First_Op);
6274 elsif Nkind (N) in N_Op then
6276 -- Remove interpretations that treat literals as addresses. This
6277 -- is never appropriate, even when Address is defined as a visible
6278 -- Integer type. The reason is that we would really prefer Address
6279 -- to behave as a private type, even in this case, which is there
6280 -- only to accommodate oddities of VMS address sizes. If Address
6281 -- is a visible integer type, we get lots of overload ambiguities.
6283 if Nkind (N) in N_Binary_Op then
6285 U1 : constant Boolean :=
6286 Present (Universal_Interpretation (Right_Opnd (N)));
6287 U2 : constant Boolean :=
6288 Present (Universal_Interpretation (Left_Opnd (N)));
6292 Remove_Address_Interpretations (Second_Op);
6296 Remove_Address_Interpretations (First_Op);
6299 if not (U1 and U2) then
6301 -- Remove corresponding predefined operator, which is
6302 -- always added to the overload set.
6304 Get_First_Interp (N, I, It);
6305 while Present (It.Nam) loop
6306 if Scope (It.Nam) = Standard_Standard
6307 and then Base_Type (It.Typ) =
6308 Base_Type (Etype (Abstract_Op))
6313 Get_Next_Interp (I, It);
6316 elsif Is_Overloaded (N)
6317 and then Present (Univ_Type)
6319 -- If both operands have a universal interpretation,
6320 -- it is still necessary to remove interpretations that
6321 -- yield Address. Any remaining ambiguities will be
6322 -- removed in Disambiguate.
6324 Get_First_Interp (N, I, It);
6325 while Present (It.Nam) loop
6326 if Is_Descendent_Of_Address (It.Typ) then
6329 elsif not Is_Type (It.Nam) then
6330 Set_Entity (N, It.Nam);
6333 Get_Next_Interp (I, It);
6339 elsif Nkind (N) = N_Function_Call
6341 (Nkind (Name (N)) = N_Operator_Symbol
6343 (Nkind (Name (N)) = N_Expanded_Name
6345 Nkind (Selector_Name (Name (N))) = N_Operator_Symbol))
6349 Arg1 : constant Node_Id := First (Parameter_Associations (N));
6350 U1 : constant Boolean :=
6351 Present (Universal_Interpretation (Arg1));
6352 U2 : constant Boolean :=
6353 Present (Next (Arg1)) and then
6354 Present (Universal_Interpretation (Next (Arg1)));
6358 Remove_Address_Interpretations (First_Op);
6362 Remove_Address_Interpretations (Second_Op);
6365 if not (U1 and U2) then
6366 Get_First_Interp (N, I, It);
6367 while Present (It.Nam) loop
6368 if Scope (It.Nam) = Standard_Standard
6369 and then It.Typ = Base_Type (Etype (Abstract_Op))
6374 Get_Next_Interp (I, It);
6380 -- If the removal has left no valid interpretations, emit an error
6381 -- message now and label node as illegal.
6383 if Present (Abstract_Op) then
6384 Get_First_Interp (N, I, It);
6388 -- Removal of abstract operation left no viable candidate
6390 Set_Etype (N, Any_Type);
6391 Error_Msg_Sloc := Sloc (Abstract_Op);
6393 ("cannot call abstract operation& declared#", N, Abstract_Op);
6395 -- In Ada 2005, an abstract operation may disable predefined
6396 -- operators. Since the context is not yet known, we mark the
6397 -- predefined operators as potentially hidden. Do not include
6398 -- predefined operators when addresses are involved since this
6399 -- case is handled separately.
6401 elsif Ada_Version >= Ada_2005
6402 and then not Address_Kludge
6404 while Present (It.Nam) loop
6405 if Is_Numeric_Type (It.Typ)
6406 and then Scope (It.Typ) = Standard_Standard
6408 Set_Abstract_Op (I, Abstract_Op);
6411 Get_Next_Interp (I, It);
6416 end Remove_Abstract_Operations;
6418 ----------------------------
6419 -- Try_Container_Indexing --
6420 ----------------------------
6422 function Try_Container_Indexing
6425 Expr : Node_Id) return Boolean
6427 Loc : constant Source_Ptr := Sloc (N);
6430 Func_Name : Node_Id;
6437 -- Check whether type has a specified indexing aspect.
6442 Ritem := First_Rep_Item (Etype (Prefix));
6443 while Present (Ritem) loop
6444 if Nkind (Ritem) = N_Aspect_Specification then
6446 -- Prefer Variable_Indexing, but will settle for Constant.
6448 if Get_Aspect_Id (Chars (Identifier (Ritem))) =
6449 Aspect_Constant_Indexing
6451 Func_Name := Expression (Ritem);
6453 elsif Get_Aspect_Id (Chars (Identifier (Ritem))) =
6454 Aspect_Variable_Indexing
6456 Func_Name := Expression (Ritem);
6462 Next_Rep_Item (Ritem);
6465 -- If aspect does not exist the expression is illegal. Error is
6466 -- diagnosed in caller.
6468 if No (Func_Name) then
6470 -- The prefix itself may be an indexing of a container
6471 -- rewrite as such and re-analyze.
6473 if Has_Implicit_Dereference (Etype (Prefix)) then
6474 Build_Explicit_Dereference
6475 (Prefix, First_Discriminant (Etype (Prefix)));
6476 return Try_Container_Indexing (N, Prefix, Expr);
6484 and then not Is_Variable (Prefix)
6486 Error_Msg_N ("Variable indexing cannot be applied to a constant", N);
6489 if not Is_Overloaded (Func_Name) then
6490 Func := Entity (Func_Name);
6491 Indexing := Make_Function_Call (Loc,
6492 Name => New_Occurrence_Of (Func, Loc),
6493 Parameter_Associations =>
6494 New_List (Relocate_Node (Prefix), Relocate_Node (Expr)));
6495 Rewrite (N, Indexing);
6498 -- The return type of the indexing function is a reference type, so
6499 -- add the dereference as a possible interpretation.
6501 Disc := First_Discriminant (Etype (Func));
6502 while Present (Disc) loop
6503 if Has_Implicit_Dereference (Disc) then
6504 Add_One_Interp (N, Disc, Designated_Type (Etype (Disc)));
6508 Next_Discriminant (Disc);
6512 Indexing := Make_Function_Call (Loc,
6513 Name => Make_Identifier (Loc, Chars (Func_Name)),
6514 Parameter_Associations =>
6515 New_List (Relocate_Node (Prefix), Relocate_Node (Expr)));
6517 Rewrite (N, Indexing);
6525 Get_First_Interp (Func_Name, I, It);
6526 Set_Etype (N, Any_Type);
6527 while Present (It.Nam) loop
6528 Analyze_One_Call (N, It.Nam, False, Success);
6530 Set_Etype (Name (N), It.Typ);
6532 -- Add implicit dereference interpretation.
6534 Disc := First_Discriminant (Etype (It.Nam));
6536 while Present (Disc) loop
6537 if Has_Implicit_Dereference (Disc) then
6539 (N, Disc, Designated_Type (Etype (Disc)));
6543 Next_Discriminant (Disc);
6546 Get_Next_Interp (I, It);
6552 end Try_Container_Indexing;
6554 -----------------------
6555 -- Try_Indirect_Call --
6556 -----------------------
6558 function Try_Indirect_Call
6561 Typ : Entity_Id) return Boolean
6567 pragma Warnings (Off, Call_OK);
6570 Normalize_Actuals (N, Designated_Type (Typ), False, Call_OK);
6572 Actual := First_Actual (N);
6573 Formal := First_Formal (Designated_Type (Typ));
6574 while Present (Actual) and then Present (Formal) loop
6575 if not Has_Compatible_Type (Actual, Etype (Formal)) then
6580 Next_Formal (Formal);
6583 if No (Actual) and then No (Formal) then
6584 Add_One_Interp (N, Nam, Etype (Designated_Type (Typ)));
6586 -- Nam is a candidate interpretation for the name in the call,
6587 -- if it is not an indirect call.
6589 if not Is_Type (Nam)
6590 and then Is_Entity_Name (Name (N))
6592 Set_Entity (Name (N), Nam);
6599 end Try_Indirect_Call;
6601 ----------------------
6602 -- Try_Indexed_Call --
6603 ----------------------
6605 function Try_Indexed_Call
6609 Skip_First : Boolean) return Boolean
6611 Loc : constant Source_Ptr := Sloc (N);
6612 Actuals : constant List_Id := Parameter_Associations (N);
6617 Actual := First (Actuals);
6619 -- If the call was originally written in prefix form, skip the first
6620 -- actual, which is obviously not defaulted.
6626 Index := First_Index (Typ);
6627 while Present (Actual) and then Present (Index) loop
6629 -- If the parameter list has a named association, the expression
6630 -- is definitely a call and not an indexed component.
6632 if Nkind (Actual) = N_Parameter_Association then
6636 if Is_Entity_Name (Actual)
6637 and then Is_Type (Entity (Actual))
6638 and then No (Next (Actual))
6640 -- A single actual that is a type name indicates a slice if the
6641 -- type is discrete, and an error otherwise.
6643 if Is_Discrete_Type (Entity (Actual)) then
6647 Make_Function_Call (Loc,
6648 Name => Relocate_Node (Name (N))),
6650 New_Occurrence_Of (Entity (Actual), Sloc (Actual))));
6655 Error_Msg_N ("invalid use of type in expression", Actual);
6656 Set_Etype (N, Any_Type);
6661 elsif not Has_Compatible_Type (Actual, Etype (Index)) then
6669 if No (Actual) and then No (Index) then
6670 Add_One_Interp (N, Nam, Component_Type (Typ));
6672 -- Nam is a candidate interpretation for the name in the call,
6673 -- if it is not an indirect call.
6675 if not Is_Type (Nam)
6676 and then Is_Entity_Name (Name (N))
6678 Set_Entity (Name (N), Nam);
6685 end Try_Indexed_Call;
6687 --------------------------
6688 -- Try_Object_Operation --
6689 --------------------------
6691 function Try_Object_Operation
6692 (N : Node_Id; CW_Test_Only : Boolean := False) return Boolean
6694 K : constant Node_Kind := Nkind (Parent (N));
6695 Is_Subprg_Call : constant Boolean := Nkind_In
6696 (K, N_Procedure_Call_Statement,
6698 Loc : constant Source_Ptr := Sloc (N);
6699 Obj : constant Node_Id := Prefix (N);
6701 Subprog : constant Node_Id :=
6702 Make_Identifier (Sloc (Selector_Name (N)),
6703 Chars => Chars (Selector_Name (N)));
6704 -- Identifier on which possible interpretations will be collected
6706 Report_Error : Boolean := False;
6707 -- If no candidate interpretation matches the context, redo the
6708 -- analysis with error enabled to provide additional information.
6711 Candidate : Entity_Id := Empty;
6712 New_Call_Node : Node_Id := Empty;
6713 Node_To_Replace : Node_Id;
6714 Obj_Type : Entity_Id := Etype (Obj);
6715 Success : Boolean := False;
6717 function Valid_Candidate
6720 Subp : Entity_Id) return Entity_Id;
6721 -- If the subprogram is a valid interpretation, record it, and add
6722 -- to the list of interpretations of Subprog. Otherwise return Empty.
6724 procedure Complete_Object_Operation
6725 (Call_Node : Node_Id;
6726 Node_To_Replace : Node_Id);
6727 -- Make Subprog the name of Call_Node, replace Node_To_Replace with
6728 -- Call_Node, insert the object (or its dereference) as the first actual
6729 -- in the call, and complete the analysis of the call.
6731 procedure Report_Ambiguity (Op : Entity_Id);
6732 -- If a prefixed procedure call is ambiguous, indicate whether the
6733 -- call includes an implicit dereference or an implicit 'Access.
6735 procedure Transform_Object_Operation
6736 (Call_Node : out Node_Id;
6737 Node_To_Replace : out Node_Id);
6738 -- Transform Obj.Operation (X, Y,,) into Operation (Obj, X, Y ..)
6739 -- Call_Node is the resulting subprogram call, Node_To_Replace is
6740 -- either N or the parent of N, and Subprog is a reference to the
6741 -- subprogram we are trying to match.
6743 function Try_Class_Wide_Operation
6744 (Call_Node : Node_Id;
6745 Node_To_Replace : Node_Id) return Boolean;
6746 -- Traverse all ancestor types looking for a class-wide subprogram
6747 -- for which the current operation is a valid non-dispatching call.
6749 procedure Try_One_Prefix_Interpretation (T : Entity_Id);
6750 -- If prefix is overloaded, its interpretation may include different
6751 -- tagged types, and we must examine the primitive operations and
6752 -- the class-wide operations of each in order to find candidate
6753 -- interpretations for the call as a whole.
6755 function Try_Primitive_Operation
6756 (Call_Node : Node_Id;
6757 Node_To_Replace : Node_Id) return Boolean;
6758 -- Traverse the list of primitive subprograms looking for a dispatching
6759 -- operation for which the current node is a valid call .
6761 ---------------------
6762 -- Valid_Candidate --
6763 ---------------------
6765 function Valid_Candidate
6768 Subp : Entity_Id) return Entity_Id
6770 Arr_Type : Entity_Id;
6771 Comp_Type : Entity_Id;
6774 -- If the subprogram is a valid interpretation, record it in global
6775 -- variable Subprog, to collect all possible overloadings.
6778 if Subp /= Entity (Subprog) then
6779 Add_One_Interp (Subprog, Subp, Etype (Subp));
6783 -- If the call may be an indexed call, retrieve component type of
6784 -- resulting expression, and add possible interpretation.
6789 if Nkind (Call) = N_Function_Call
6790 and then Nkind (Parent (N)) = N_Indexed_Component
6791 and then Needs_One_Actual (Subp)
6793 if Is_Array_Type (Etype (Subp)) then
6794 Arr_Type := Etype (Subp);
6796 elsif Is_Access_Type (Etype (Subp))
6797 and then Is_Array_Type (Designated_Type (Etype (Subp)))
6799 Arr_Type := Designated_Type (Etype (Subp));
6803 if Present (Arr_Type) then
6805 -- Verify that the actuals (excluding the object) match the types
6813 Actual := Next (First_Actual (Call));
6814 Index := First_Index (Arr_Type);
6815 while Present (Actual) and then Present (Index) loop
6816 if not Has_Compatible_Type (Actual, Etype (Index)) then
6821 Next_Actual (Actual);
6827 and then Present (Arr_Type)
6829 Comp_Type := Component_Type (Arr_Type);
6833 if Present (Comp_Type)
6834 and then Etype (Subprog) /= Comp_Type
6836 Add_One_Interp (Subprog, Subp, Comp_Type);
6840 if Etype (Call) /= Any_Type then
6845 end Valid_Candidate;
6847 -------------------------------
6848 -- Complete_Object_Operation --
6849 -------------------------------
6851 procedure Complete_Object_Operation
6852 (Call_Node : Node_Id;
6853 Node_To_Replace : Node_Id)
6855 Control : constant Entity_Id := First_Formal (Entity (Subprog));
6856 Formal_Type : constant Entity_Id := Etype (Control);
6857 First_Actual : Node_Id;
6860 -- Place the name of the operation, with its interpretations,
6861 -- on the rewritten call.
6863 Set_Name (Call_Node, Subprog);
6865 First_Actual := First (Parameter_Associations (Call_Node));
6867 -- For cross-reference purposes, treat the new node as being in
6868 -- the source if the original one is.
6870 Set_Comes_From_Source (Subprog, Comes_From_Source (N));
6871 Set_Comes_From_Source (Call_Node, Comes_From_Source (N));
6873 if Nkind (N) = N_Selected_Component
6874 and then not Inside_A_Generic
6876 Set_Entity (Selector_Name (N), Entity (Subprog));
6879 -- If need be, rewrite first actual as an explicit dereference
6880 -- If the call is overloaded, the rewriting can only be done
6881 -- once the primitive operation is identified.
6883 if Is_Overloaded (Subprog) then
6885 -- The prefix itself may be overloaded, and its interpretations
6886 -- must be propagated to the new actual in the call.
6888 if Is_Overloaded (Obj) then
6889 Save_Interps (Obj, First_Actual);
6892 Rewrite (First_Actual, Obj);
6894 elsif not Is_Access_Type (Formal_Type)
6895 and then Is_Access_Type (Etype (Obj))
6897 Rewrite (First_Actual,
6898 Make_Explicit_Dereference (Sloc (Obj), Obj));
6899 Analyze (First_Actual);
6901 -- If we need to introduce an explicit dereference, verify that
6902 -- the resulting actual is compatible with the mode of the formal.
6904 if Ekind (First_Formal (Entity (Subprog))) /= E_In_Parameter
6905 and then Is_Access_Constant (Etype (Obj))
6908 ("expect variable in call to&", Prefix (N), Entity (Subprog));
6911 -- Conversely, if the formal is an access parameter and the object
6912 -- is not, replace the actual with a 'Access reference. Its analysis
6913 -- will check that the object is aliased.
6915 elsif Is_Access_Type (Formal_Type)
6916 and then not Is_Access_Type (Etype (Obj))
6918 -- A special case: A.all'access is illegal if A is an access to a
6919 -- constant and the context requires an access to a variable.
6921 if not Is_Access_Constant (Formal_Type) then
6922 if (Nkind (Obj) = N_Explicit_Dereference
6923 and then Is_Access_Constant (Etype (Prefix (Obj))))
6924 or else not Is_Variable (Obj)
6927 ("actual for& must be a variable", Obj, Control);
6931 Rewrite (First_Actual,
6932 Make_Attribute_Reference (Loc,
6933 Attribute_Name => Name_Access,
6934 Prefix => Relocate_Node (Obj)));
6936 if not Is_Aliased_View (Obj) then
6938 ("object in prefixed call to& must be aliased"
6939 & " (RM-2005 4.3.1 (13))",
6940 Prefix (First_Actual), Subprog);
6943 Analyze (First_Actual);
6946 if Is_Overloaded (Obj) then
6947 Save_Interps (Obj, First_Actual);
6950 Rewrite (First_Actual, Obj);
6953 Rewrite (Node_To_Replace, Call_Node);
6955 -- Propagate the interpretations collected in subprog to the new
6956 -- function call node, to be resolved from context.
6958 if Is_Overloaded (Subprog) then
6959 Save_Interps (Subprog, Node_To_Replace);
6962 Analyze (Node_To_Replace);
6964 -- If the operation has been rewritten into a call, which may get
6965 -- subsequently an explicit dereference, preserve the type on the
6966 -- original node (selected component or indexed component) for
6967 -- subsequent legality tests, e.g. Is_Variable. which examines
6968 -- the original node.
6970 if Nkind (Node_To_Replace) = N_Function_Call then
6972 (Original_Node (Node_To_Replace), Etype (Node_To_Replace));
6975 end Complete_Object_Operation;
6977 ----------------------
6978 -- Report_Ambiguity --
6979 ----------------------
6981 procedure Report_Ambiguity (Op : Entity_Id) is
6982 Access_Actual : constant Boolean :=
6983 Is_Access_Type (Etype (Prefix (N)));
6984 Access_Formal : Boolean := False;
6987 Error_Msg_Sloc := Sloc (Op);
6989 if Present (First_Formal (Op)) then
6990 Access_Formal := Is_Access_Type (Etype (First_Formal (Op)));
6993 if Access_Formal and then not Access_Actual then
6994 if Nkind (Parent (Op)) = N_Full_Type_Declaration then
6996 ("\possible interpretation"
6997 & " (inherited, with implicit 'Access) #", N);
7000 ("\possible interpretation (with implicit 'Access) #", N);
7003 elsif not Access_Formal and then Access_Actual then
7004 if Nkind (Parent (Op)) = N_Full_Type_Declaration then
7006 ("\possible interpretation"
7007 & " ( inherited, with implicit dereference) #", N);
7010 ("\possible interpretation (with implicit dereference) #", N);
7014 if Nkind (Parent (Op)) = N_Full_Type_Declaration then
7015 Error_Msg_N ("\possible interpretation (inherited)#", N);
7017 Error_Msg_N -- CODEFIX
7018 ("\possible interpretation#", N);
7021 end Report_Ambiguity;
7023 --------------------------------
7024 -- Transform_Object_Operation --
7025 --------------------------------
7027 procedure Transform_Object_Operation
7028 (Call_Node : out Node_Id;
7029 Node_To_Replace : out Node_Id)
7031 Dummy : constant Node_Id := New_Copy (Obj);
7032 -- Placeholder used as a first parameter in the call, replaced
7033 -- eventually by the proper object.
7035 Parent_Node : constant Node_Id := Parent (N);
7041 -- Common case covering 1) Call to a procedure and 2) Call to a
7042 -- function that has some additional actuals.
7044 if Nkind_In (Parent_Node, N_Function_Call,
7045 N_Procedure_Call_Statement)
7047 -- N is a selected component node containing the name of the
7048 -- subprogram. If N is not the name of the parent node we must
7049 -- not replace the parent node by the new construct. This case
7050 -- occurs when N is a parameterless call to a subprogram that
7051 -- is an actual parameter of a call to another subprogram. For
7053 -- Some_Subprogram (..., Obj.Operation, ...)
7055 and then Name (Parent_Node) = N
7057 Node_To_Replace := Parent_Node;
7059 Actuals := Parameter_Associations (Parent_Node);
7061 if Present (Actuals) then
7062 Prepend (Dummy, Actuals);
7064 Actuals := New_List (Dummy);
7067 if Nkind (Parent_Node) = N_Procedure_Call_Statement then
7069 Make_Procedure_Call_Statement (Loc,
7070 Name => New_Copy (Subprog),
7071 Parameter_Associations => Actuals);
7075 Make_Function_Call (Loc,
7076 Name => New_Copy (Subprog),
7077 Parameter_Associations => Actuals);
7081 -- Before analysis, a function call appears as an indexed component
7082 -- if there are no named associations.
7084 elsif Nkind (Parent_Node) = N_Indexed_Component
7085 and then N = Prefix (Parent_Node)
7087 Node_To_Replace := Parent_Node;
7088 Actuals := Expressions (Parent_Node);
7090 Actual := First (Actuals);
7091 while Present (Actual) loop
7096 Prepend (Dummy, Actuals);
7099 Make_Function_Call (Loc,
7100 Name => New_Copy (Subprog),
7101 Parameter_Associations => Actuals);
7103 -- Parameterless call: Obj.F is rewritten as F (Obj)
7106 Node_To_Replace := N;
7109 Make_Function_Call (Loc,
7110 Name => New_Copy (Subprog),
7111 Parameter_Associations => New_List (Dummy));
7113 end Transform_Object_Operation;
7115 ------------------------------
7116 -- Try_Class_Wide_Operation --
7117 ------------------------------
7119 function Try_Class_Wide_Operation
7120 (Call_Node : Node_Id;
7121 Node_To_Replace : Node_Id) return Boolean
7123 Anc_Type : Entity_Id;
7124 Matching_Op : Entity_Id := Empty;
7127 procedure Traverse_Homonyms
7128 (Anc_Type : Entity_Id;
7129 Error : out Boolean);
7130 -- Traverse the homonym chain of the subprogram searching for those
7131 -- homonyms whose first formal has the Anc_Type's class-wide type,
7132 -- or an anonymous access type designating the class-wide type. If
7133 -- an ambiguity is detected, then Error is set to True.
7135 procedure Traverse_Interfaces
7136 (Anc_Type : Entity_Id;
7137 Error : out Boolean);
7138 -- Traverse the list of interfaces, if any, associated with Anc_Type
7139 -- and search for acceptable class-wide homonyms associated with each
7140 -- interface. If an ambiguity is detected, then Error is set to True.
7142 -----------------------
7143 -- Traverse_Homonyms --
7144 -----------------------
7146 procedure Traverse_Homonyms
7147 (Anc_Type : Entity_Id;
7148 Error : out Boolean)
7150 Cls_Type : Entity_Id;
7158 Cls_Type := Class_Wide_Type (Anc_Type);
7160 Hom := Current_Entity (Subprog);
7162 -- Find a non-hidden operation whose first parameter is of the
7163 -- class-wide type, a subtype thereof, or an anonymous access
7166 while Present (Hom) loop
7167 if Ekind_In (Hom, E_Procedure, E_Function)
7168 and then not Is_Hidden (Hom)
7169 and then Scope (Hom) = Scope (Anc_Type)
7170 and then Present (First_Formal (Hom))
7172 (Base_Type (Etype (First_Formal (Hom))) = Cls_Type
7174 (Is_Access_Type (Etype (First_Formal (Hom)))
7176 Ekind (Etype (First_Formal (Hom))) =
7177 E_Anonymous_Access_Type
7180 (Designated_Type (Etype (First_Formal (Hom)))) =
7183 -- If the context is a procedure call, ignore functions
7184 -- in the name of the call.
7186 if Ekind (Hom) = E_Function
7187 and then Nkind (Parent (N)) = N_Procedure_Call_Statement
7188 and then N = Name (Parent (N))
7192 -- If the context is a function call, ignore procedures
7193 -- in the name of the call.
7195 elsif Ekind (Hom) = E_Procedure
7196 and then Nkind (Parent (N)) /= N_Procedure_Call_Statement
7201 Set_Etype (Call_Node, Any_Type);
7202 Set_Is_Overloaded (Call_Node, False);
7205 if No (Matching_Op) then
7206 Hom_Ref := New_Reference_To (Hom, Sloc (Subprog));
7207 Set_Etype (Call_Node, Any_Type);
7208 Set_Parent (Call_Node, Parent (Node_To_Replace));
7210 Set_Name (Call_Node, Hom_Ref);
7215 Report => Report_Error,
7217 Skip_First => True);
7220 Valid_Candidate (Success, Call_Node, Hom);
7226 Report => Report_Error,
7228 Skip_First => True);
7230 if Present (Valid_Candidate (Success, Call_Node, Hom))
7231 and then Nkind (Call_Node) /= N_Function_Call
7233 Error_Msg_NE ("ambiguous call to&", N, Hom);
7234 Report_Ambiguity (Matching_Op);
7235 Report_Ambiguity (Hom);
7243 Hom := Homonym (Hom);
7245 end Traverse_Homonyms;
7247 -------------------------
7248 -- Traverse_Interfaces --
7249 -------------------------
7251 procedure Traverse_Interfaces
7252 (Anc_Type : Entity_Id;
7253 Error : out Boolean)
7255 Intface_List : constant List_Id :=
7256 Abstract_Interface_List (Anc_Type);
7262 if Is_Non_Empty_List (Intface_List) then
7263 Intface := First (Intface_List);
7264 while Present (Intface) loop
7266 -- Look for acceptable class-wide homonyms associated with
7269 Traverse_Homonyms (Etype (Intface), Error);
7275 -- Continue the search by looking at each of the interface's
7276 -- associated interface ancestors.
7278 Traverse_Interfaces (Etype (Intface), Error);
7287 end Traverse_Interfaces;
7289 -- Start of processing for Try_Class_Wide_Operation
7292 -- If we are searching only for conflicting class-wide subprograms
7293 -- then initialize directly Matching_Op with the target entity.
7295 if CW_Test_Only then
7296 Matching_Op := Entity (Selector_Name (N));
7299 -- Loop through ancestor types (including interfaces), traversing
7300 -- the homonym chain of the subprogram, trying out those homonyms
7301 -- whose first formal has the class-wide type of the ancestor, or
7302 -- an anonymous access type designating the class-wide type.
7304 Anc_Type := Obj_Type;
7306 -- Look for a match among homonyms associated with the ancestor
7308 Traverse_Homonyms (Anc_Type, Error);
7314 -- Continue the search for matches among homonyms associated with
7315 -- any interfaces implemented by the ancestor.
7317 Traverse_Interfaces (Anc_Type, Error);
7323 exit when Etype (Anc_Type) = Anc_Type;
7324 Anc_Type := Etype (Anc_Type);
7327 if Present (Matching_Op) then
7328 Set_Etype (Call_Node, Etype (Matching_Op));
7331 return Present (Matching_Op);
7332 end Try_Class_Wide_Operation;
7334 -----------------------------------
7335 -- Try_One_Prefix_Interpretation --
7336 -----------------------------------
7338 procedure Try_One_Prefix_Interpretation (T : Entity_Id) is
7342 if Is_Access_Type (Obj_Type) then
7343 Obj_Type := Designated_Type (Obj_Type);
7346 if Ekind (Obj_Type) = E_Private_Subtype then
7347 Obj_Type := Base_Type (Obj_Type);
7350 if Is_Class_Wide_Type (Obj_Type) then
7351 Obj_Type := Etype (Class_Wide_Type (Obj_Type));
7354 -- The type may have be obtained through a limited_with clause,
7355 -- in which case the primitive operations are available on its
7356 -- non-limited view. If still incomplete, retrieve full view.
7358 if Ekind (Obj_Type) = E_Incomplete_Type
7359 and then From_With_Type (Obj_Type)
7361 Obj_Type := Get_Full_View (Non_Limited_View (Obj_Type));
7364 -- If the object is not tagged, or the type is still an incomplete
7365 -- type, this is not a prefixed call.
7367 if not Is_Tagged_Type (Obj_Type)
7368 or else Is_Incomplete_Type (Obj_Type)
7374 Dup_Call_Node : constant Node_Id := New_Copy (New_Call_Node);
7375 CW_Result : Boolean;
7376 Prim_Result : Boolean;
7377 pragma Unreferenced (CW_Result);
7380 if not CW_Test_Only then
7382 Try_Primitive_Operation
7383 (Call_Node => New_Call_Node,
7384 Node_To_Replace => Node_To_Replace);
7387 -- Check if there is a class-wide subprogram covering the
7388 -- primitive. This check must be done even if a candidate
7389 -- was found in order to report ambiguous calls.
7391 if not (Prim_Result) then
7393 Try_Class_Wide_Operation
7394 (Call_Node => New_Call_Node,
7395 Node_To_Replace => Node_To_Replace);
7397 -- If we found a primitive we search for class-wide subprograms
7398 -- using a duplicate of the call node (done to avoid missing its
7399 -- decoration if there is no ambiguity).
7403 Try_Class_Wide_Operation
7404 (Call_Node => Dup_Call_Node,
7405 Node_To_Replace => Node_To_Replace);
7408 end Try_One_Prefix_Interpretation;
7410 -----------------------------
7411 -- Try_Primitive_Operation --
7412 -----------------------------
7414 function Try_Primitive_Operation
7415 (Call_Node : Node_Id;
7416 Node_To_Replace : Node_Id) return Boolean
7419 Prim_Op : Entity_Id;
7420 Matching_Op : Entity_Id := Empty;
7421 Prim_Op_Ref : Node_Id := Empty;
7423 Corr_Type : Entity_Id := Empty;
7424 -- If the prefix is a synchronized type, the controlling type of
7425 -- the primitive operation is the corresponding record type, else
7426 -- this is the object type itself.
7428 Success : Boolean := False;
7430 function Collect_Generic_Type_Ops (T : Entity_Id) return Elist_Id;
7431 -- For tagged types the candidate interpretations are found in
7432 -- the list of primitive operations of the type and its ancestors.
7433 -- For formal tagged types we have to find the operations declared
7434 -- in the same scope as the type (including in the generic formal
7435 -- part) because the type itself carries no primitive operations,
7436 -- except for formal derived types that inherit the operations of
7437 -- the parent and progenitors.
7438 -- If the context is a generic subprogram body, the generic formals
7439 -- are visible by name, but are not in the entity list of the
7440 -- subprogram because that list starts with the subprogram formals.
7441 -- We retrieve the candidate operations from the generic declaration.
7443 function Is_Private_Overriding (Op : Entity_Id) return Boolean;
7444 -- An operation that overrides an inherited operation in the private
7445 -- part of its package may be hidden, but if the inherited operation
7446 -- is visible a direct call to it will dispatch to the private one,
7447 -- which is therefore a valid candidate.
7449 function Valid_First_Argument_Of (Op : Entity_Id) return Boolean;
7450 -- Verify that the prefix, dereferenced if need be, is a valid
7451 -- controlling argument in a call to Op. The remaining actuals
7452 -- are checked in the subsequent call to Analyze_One_Call.
7454 ------------------------------
7455 -- Collect_Generic_Type_Ops --
7456 ------------------------------
7458 function Collect_Generic_Type_Ops (T : Entity_Id) return Elist_Id is
7459 Bas : constant Entity_Id := Base_Type (T);
7460 Candidates : constant Elist_Id := New_Elmt_List;
7464 procedure Check_Candidate;
7465 -- The operation is a candidate if its first parameter is a
7466 -- controlling operand of the desired type.
7468 -----------------------
7469 -- Check_Candidate; --
7470 -----------------------
7472 procedure Check_Candidate is
7474 Formal := First_Formal (Subp);
7477 and then Is_Controlling_Formal (Formal)
7479 (Base_Type (Etype (Formal)) = Bas
7481 (Is_Access_Type (Etype (Formal))
7482 and then Designated_Type (Etype (Formal)) = Bas))
7484 Append_Elmt (Subp, Candidates);
7486 end Check_Candidate;
7488 -- Start of processing for Collect_Generic_Type_Ops
7491 if Is_Derived_Type (T) then
7492 return Primitive_Operations (T);
7494 elsif Ekind_In (Scope (T), E_Procedure, E_Function) then
7496 -- Scan the list of generic formals to find subprograms
7497 -- that may have a first controlling formal of the type.
7499 if Nkind (Unit_Declaration_Node (Scope (T)))
7500 = N_Generic_Subprogram_Declaration
7507 First (Generic_Formal_Declarations
7508 (Unit_Declaration_Node (Scope (T))));
7509 while Present (Decl) loop
7510 if Nkind (Decl) in N_Formal_Subprogram_Declaration then
7511 Subp := Defining_Entity (Decl);
7522 -- Scan the list of entities declared in the same scope as
7523 -- the type. In general this will be an open scope, given that
7524 -- the call we are analyzing can only appear within a generic
7525 -- declaration or body (either the one that declares T, or a
7528 -- For a subtype representing a generic actual type, go to the
7531 if Is_Generic_Actual_Type (T) then
7532 Subp := First_Entity (Scope (Base_Type (T)));
7534 Subp := First_Entity (Scope (T));
7537 while Present (Subp) loop
7538 if Is_Overloadable (Subp) then
7547 end Collect_Generic_Type_Ops;
7549 ---------------------------
7550 -- Is_Private_Overriding --
7551 ---------------------------
7553 function Is_Private_Overriding (Op : Entity_Id) return Boolean is
7554 Visible_Op : constant Entity_Id := Homonym (Op);
7557 return Present (Visible_Op)
7558 and then Scope (Op) = Scope (Visible_Op)
7559 and then not Comes_From_Source (Visible_Op)
7560 and then Alias (Visible_Op) = Op
7561 and then not Is_Hidden (Visible_Op);
7562 end Is_Private_Overriding;
7564 -----------------------------
7565 -- Valid_First_Argument_Of --
7566 -----------------------------
7568 function Valid_First_Argument_Of (Op : Entity_Id) return Boolean is
7569 Typ : Entity_Id := Etype (First_Formal (Op));
7572 if Is_Concurrent_Type (Typ)
7573 and then Present (Corresponding_Record_Type (Typ))
7575 Typ := Corresponding_Record_Type (Typ);
7578 -- Simple case. Object may be a subtype of the tagged type or
7579 -- may be the corresponding record of a synchronized type.
7581 return Obj_Type = Typ
7582 or else Base_Type (Obj_Type) = Typ
7583 or else Corr_Type = Typ
7585 -- Prefix can be dereferenced
7588 (Is_Access_Type (Corr_Type)
7589 and then Designated_Type (Corr_Type) = Typ)
7591 -- Formal is an access parameter, for which the object
7592 -- can provide an access.
7595 (Ekind (Typ) = E_Anonymous_Access_Type
7597 Base_Type (Designated_Type (Typ)) = Base_Type (Corr_Type));
7598 end Valid_First_Argument_Of;
7600 -- Start of processing for Try_Primitive_Operation
7603 -- Look for subprograms in the list of primitive operations. The name
7604 -- must be identical, and the kind of call indicates the expected
7605 -- kind of operation (function or procedure). If the type is a
7606 -- (tagged) synchronized type, the primitive ops are attached to the
7607 -- corresponding record (base) type.
7609 if Is_Concurrent_Type (Obj_Type) then
7610 if Present (Corresponding_Record_Type (Obj_Type)) then
7611 Corr_Type := Base_Type (Corresponding_Record_Type (Obj_Type));
7612 Elmt := First_Elmt (Primitive_Operations (Corr_Type));
7614 Corr_Type := Obj_Type;
7615 Elmt := First_Elmt (Collect_Generic_Type_Ops (Obj_Type));
7618 elsif not Is_Generic_Type (Obj_Type) then
7619 Corr_Type := Obj_Type;
7620 Elmt := First_Elmt (Primitive_Operations (Obj_Type));
7623 Corr_Type := Obj_Type;
7624 Elmt := First_Elmt (Collect_Generic_Type_Ops (Obj_Type));
7627 while Present (Elmt) loop
7628 Prim_Op := Node (Elmt);
7630 if Chars (Prim_Op) = Chars (Subprog)
7631 and then Present (First_Formal (Prim_Op))
7632 and then Valid_First_Argument_Of (Prim_Op)
7634 (Nkind (Call_Node) = N_Function_Call)
7635 = (Ekind (Prim_Op) = E_Function)
7637 -- Ada 2005 (AI-251): If this primitive operation corresponds
7638 -- with an immediate ancestor interface there is no need to add
7639 -- it to the list of interpretations; the corresponding aliased
7640 -- primitive is also in this list of primitive operations and
7641 -- will be used instead.
7643 if (Present (Interface_Alias (Prim_Op))
7644 and then Is_Ancestor (Find_Dispatching_Type
7645 (Alias (Prim_Op)), Corr_Type))
7647 -- Do not consider hidden primitives unless the type is in an
7648 -- open scope or we are within an instance, where visibility
7649 -- is known to be correct, or else if this is an overriding
7650 -- operation in the private part for an inherited operation.
7652 or else (Is_Hidden (Prim_Op)
7653 and then not Is_Immediately_Visible (Obj_Type)
7654 and then not In_Instance
7655 and then not Is_Private_Overriding (Prim_Op))
7660 Set_Etype (Call_Node, Any_Type);
7661 Set_Is_Overloaded (Call_Node, False);
7663 if No (Matching_Op) then
7664 Prim_Op_Ref := New_Reference_To (Prim_Op, Sloc (Subprog));
7665 Candidate := Prim_Op;
7667 Set_Parent (Call_Node, Parent (Node_To_Replace));
7669 Set_Name (Call_Node, Prim_Op_Ref);
7675 Report => Report_Error,
7677 Skip_First => True);
7679 Matching_Op := Valid_Candidate (Success, Call_Node, Prim_Op);
7681 -- More than one interpretation, collect for subsequent
7682 -- disambiguation. If this is a procedure call and there
7683 -- is another match, report ambiguity now.
7689 Report => Report_Error,
7691 Skip_First => True);
7693 if Present (Valid_Candidate (Success, Call_Node, Prim_Op))
7694 and then Nkind (Call_Node) /= N_Function_Call
7696 Error_Msg_NE ("ambiguous call to&", N, Prim_Op);
7697 Report_Ambiguity (Matching_Op);
7698 Report_Ambiguity (Prim_Op);
7708 if Present (Matching_Op) then
7709 Set_Etype (Call_Node, Etype (Matching_Op));
7712 return Present (Matching_Op);
7713 end Try_Primitive_Operation;
7715 -- Start of processing for Try_Object_Operation
7718 Analyze_Expression (Obj);
7720 -- Analyze the actuals if node is known to be a subprogram call
7722 if Is_Subprg_Call and then N = Name (Parent (N)) then
7723 Actual := First (Parameter_Associations (Parent (N)));
7724 while Present (Actual) loop
7725 Analyze_Expression (Actual);
7730 -- Build a subprogram call node, using a copy of Obj as its first
7731 -- actual. This is a placeholder, to be replaced by an explicit
7732 -- dereference when needed.
7734 Transform_Object_Operation
7735 (Call_Node => New_Call_Node,
7736 Node_To_Replace => Node_To_Replace);
7738 Set_Etype (New_Call_Node, Any_Type);
7739 Set_Etype (Subprog, Any_Type);
7740 Set_Parent (New_Call_Node, Parent (Node_To_Replace));
7742 if not Is_Overloaded (Obj) then
7743 Try_One_Prefix_Interpretation (Obj_Type);
7750 Get_First_Interp (Obj, I, It);
7751 while Present (It.Nam) loop
7752 Try_One_Prefix_Interpretation (It.Typ);
7753 Get_Next_Interp (I, It);
7758 if Etype (New_Call_Node) /= Any_Type then
7760 -- No need to complete the tree transformations if we are only
7761 -- searching for conflicting class-wide subprograms
7763 if CW_Test_Only then
7766 Complete_Object_Operation
7767 (Call_Node => New_Call_Node,
7768 Node_To_Replace => Node_To_Replace);
7772 elsif Present (Candidate) then
7774 -- The argument list is not type correct. Re-analyze with error
7775 -- reporting enabled, and use one of the possible candidates.
7776 -- In All_Errors_Mode, re-analyze all failed interpretations.
7778 if All_Errors_Mode then
7779 Report_Error := True;
7780 if Try_Primitive_Operation
7781 (Call_Node => New_Call_Node,
7782 Node_To_Replace => Node_To_Replace)
7785 Try_Class_Wide_Operation
7786 (Call_Node => New_Call_Node,
7787 Node_To_Replace => Node_To_Replace)
7794 (N => New_Call_Node,
7798 Skip_First => True);
7801 -- No need for further errors
7806 -- There was no candidate operation, so report it as an error
7807 -- in the caller: Analyze_Selected_Component.
7811 end Try_Object_Operation;
7817 procedure wpo (T : Entity_Id) is
7822 if not Is_Tagged_Type (T) then
7826 E := First_Elmt (Primitive_Operations (Base_Type (T)));
7827 while Present (E) loop
7829 Write_Int (Int (Op));
7830 Write_Str (" === ");
7831 Write_Name (Chars (Op));
7833 Write_Name (Chars (Scope (Op)));