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 Effectively_Has_Constrained_Partial_View
581 Scop => Current_Scope)
584 ("constraint not allowed when type " &
585 "has a constrained partial view", Constraint (E));
588 if Expander_Active then
589 Def_Id := Make_Temporary (Loc, 'S');
592 Make_Subtype_Declaration (Loc,
593 Defining_Identifier => Def_Id,
594 Subtype_Indication => Relocate_Node (E)));
596 if Sav_Errs /= Serious_Errors_Detected
597 and then Nkind (Constraint (E)) =
598 N_Index_Or_Discriminant_Constraint
600 Error_Msg_N -- CODEFIX
601 ("if qualified expression was meant, " &
602 "use apostrophe!", Constraint (E));
605 E := New_Occurrence_Of (Def_Id, Loc);
606 Rewrite (Expression (N), E);
610 Type_Id := Process_Subtype (E, N);
611 Acc_Type := Create_Itype (E_Allocator_Type, N);
612 Set_Etype (Acc_Type, Acc_Type);
613 Set_Directly_Designated_Type (Acc_Type, Type_Id);
614 Check_Fully_Declared (Type_Id, N);
616 -- Ada 2005 (AI-231): If the designated type is itself an access
617 -- type that excludes null, its default initialization will
618 -- be a null object, and we can insert an unconditional raise
619 -- before the allocator.
621 -- Ada 2012 (AI-104): A not null indication here is altogether
624 if Can_Never_Be_Null (Type_Id) then
626 Not_Null_Check : constant Node_Id :=
627 Make_Raise_Constraint_Error (Sloc (E),
628 Reason => CE_Null_Not_Allowed);
631 if Ada_Version >= Ada_2012 then
633 ("an uninitialized allocator cannot have"
634 & " a null exclusion", N);
636 elsif Expander_Active then
637 Insert_Action (N, Not_Null_Check);
638 Analyze (Not_Null_Check);
641 Error_Msg_N ("null value not allowed here?", E);
646 -- Check restriction against dynamically allocated protected
647 -- objects. Note that when limited aggregates are supported,
648 -- a similar test should be applied to an allocator with a
649 -- qualified expression ???
651 if Is_Protected_Type (Type_Id) then
652 Check_Restriction (No_Protected_Type_Allocators, N);
655 -- Check for missing initialization. Skip this check if we already
656 -- had errors on analyzing the allocator, since in that case these
657 -- are probably cascaded errors.
659 if Is_Indefinite_Subtype (Type_Id)
660 and then Serious_Errors_Detected = Sav_Errs
662 if Is_Class_Wide_Type (Type_Id) then
664 ("initialization required in class-wide allocation", N);
666 if Ada_Version < Ada_2005
667 and then Is_Limited_Type (Type_Id)
669 Error_Msg_N ("unconstrained allocation not allowed", N);
671 if Is_Array_Type (Type_Id) then
673 ("\constraint with array bounds required", N);
675 elsif Has_Unknown_Discriminants (Type_Id) then
678 else pragma Assert (Has_Discriminants (Type_Id));
680 ("\constraint with discriminant values required", N);
683 -- Limited Ada 2005 and general non-limited case
687 ("uninitialized unconstrained allocation not allowed",
690 if Is_Array_Type (Type_Id) then
692 ("\qualified expression or constraint with " &
693 "array bounds required", N);
695 elsif Has_Unknown_Discriminants (Type_Id) then
696 Error_Msg_N ("\qualified expression required", N);
698 else pragma Assert (Has_Discriminants (Type_Id));
700 ("\qualified expression or constraint with " &
701 "discriminant values required", N);
709 if Is_Abstract_Type (Type_Id) then
710 Error_Msg_N ("cannot allocate abstract object", E);
713 if Has_Task (Designated_Type (Acc_Type)) then
714 Check_Restriction (No_Tasking, N);
715 Check_Restriction (Max_Tasks, N);
716 Check_Restriction (No_Task_Allocators, N);
719 -- AI05-0013-1: No_Nested_Finalization forbids allocators if the access
720 -- type is nested, and the designated type needs finalization. The rule
721 -- is conservative in that class-wide types need finalization.
723 if Needs_Finalization (Designated_Type (Acc_Type))
724 and then not Is_Library_Level_Entity (Acc_Type)
726 Check_Restriction (No_Nested_Finalization, N);
729 -- Check that an allocator of a nested access type doesn't create a
730 -- protected object when restriction No_Local_Protected_Objects applies.
731 -- We don't have an equivalent to Has_Task for protected types, so only
732 -- cases where the designated type itself is a protected type are
733 -- currently checked. ???
735 if Is_Protected_Type (Designated_Type (Acc_Type))
736 and then not Is_Library_Level_Entity (Acc_Type)
738 Check_Restriction (No_Local_Protected_Objects, N);
741 -- If the No_Streams restriction is set, check that the type of the
742 -- object is not, and does not contain, any subtype derived from
743 -- Ada.Streams.Root_Stream_Type. Note that we guard the call to
744 -- Has_Stream just for efficiency reasons. There is no point in
745 -- spending time on a Has_Stream check if the restriction is not set.
747 if Restriction_Check_Required (No_Streams) then
748 if Has_Stream (Designated_Type (Acc_Type)) then
749 Check_Restriction (No_Streams, N);
753 Set_Etype (N, Acc_Type);
755 if not Is_Library_Level_Entity (Acc_Type) then
756 Check_Restriction (No_Local_Allocators, N);
759 if Serious_Errors_Detected > Sav_Errs then
760 Set_Error_Posted (N);
761 Set_Etype (N, Any_Type);
763 end Analyze_Allocator;
765 ---------------------------
766 -- Analyze_Arithmetic_Op --
767 ---------------------------
769 procedure Analyze_Arithmetic_Op (N : Node_Id) is
770 L : constant Node_Id := Left_Opnd (N);
771 R : constant Node_Id := Right_Opnd (N);
775 Candidate_Type := Empty;
776 Analyze_Expression (L);
777 Analyze_Expression (R);
779 -- If the entity is already set, the node is the instantiation of a
780 -- generic node with a non-local reference, or was manufactured by a
781 -- call to Make_Op_xxx. In either case the entity is known to be valid,
782 -- and we do not need to collect interpretations, instead we just get
783 -- the single possible interpretation.
787 if Present (Op_Id) then
788 if Ekind (Op_Id) = E_Operator then
790 if Nkind_In (N, N_Op_Divide, N_Op_Mod, N_Op_Multiply, N_Op_Rem)
791 and then Treat_Fixed_As_Integer (N)
795 Set_Etype (N, Any_Type);
796 Find_Arithmetic_Types (L, R, Op_Id, N);
800 Set_Etype (N, Any_Type);
801 Add_One_Interp (N, Op_Id, Etype (Op_Id));
804 -- Entity is not already set, so we do need to collect interpretations
807 Op_Id := Get_Name_Entity_Id (Chars (N));
808 Set_Etype (N, Any_Type);
810 while Present (Op_Id) loop
811 if Ekind (Op_Id) = E_Operator
812 and then Present (Next_Entity (First_Entity (Op_Id)))
814 Find_Arithmetic_Types (L, R, Op_Id, N);
816 -- The following may seem superfluous, because an operator cannot
817 -- be generic, but this ignores the cleverness of the author of
820 elsif Is_Overloadable (Op_Id) then
821 Analyze_User_Defined_Binary_Op (N, Op_Id);
824 Op_Id := Homonym (Op_Id);
829 end Analyze_Arithmetic_Op;
835 -- Function, procedure, and entry calls are checked here. The Name in
836 -- the call may be overloaded. The actuals have been analyzed and may
837 -- themselves be overloaded. On exit from this procedure, the node N
838 -- may have zero, one or more interpretations. In the first case an
839 -- error message is produced. In the last case, the node is flagged
840 -- as overloaded and the interpretations are collected in All_Interp.
842 -- If the name is an Access_To_Subprogram, it cannot be overloaded, but
843 -- the type-checking is similar to that of other calls.
845 procedure Analyze_Call (N : Node_Id) is
846 Actuals : constant List_Id := Parameter_Associations (N);
851 Success : Boolean := False;
853 Deref : Boolean := False;
854 -- Flag indicates whether an interpretation of the prefix is a
855 -- parameterless call that returns an access_to_subprogram.
857 procedure Check_Mixed_Parameter_And_Named_Associations;
858 -- Check that parameter and named associations are not mixed. This is
859 -- a restriction in SPARK mode.
861 function Name_Denotes_Function return Boolean;
862 -- If the type of the name is an access to subprogram, this may be the
863 -- type of a name, or the return type of the function being called. If
864 -- the name is not an entity then it can denote a protected function.
865 -- Until we distinguish Etype from Return_Type, we must use this routine
866 -- to resolve the meaning of the name in the call.
868 procedure No_Interpretation;
869 -- Output error message when no valid interpretation exists
871 --------------------------------------------------
872 -- Check_Mixed_Parameter_And_Named_Associations --
873 --------------------------------------------------
875 procedure Check_Mixed_Parameter_And_Named_Associations is
877 Named_Seen : Boolean;
882 Actual := First (Actuals);
883 while Present (Actual) loop
884 case Nkind (Actual) is
885 when N_Parameter_Association =>
887 Check_SPARK_Restriction
888 ("named association cannot follow positional one",
898 end Check_Mixed_Parameter_And_Named_Associations;
900 ---------------------------
901 -- Name_Denotes_Function --
902 ---------------------------
904 function Name_Denotes_Function return Boolean is
906 if Is_Entity_Name (Nam) then
907 return Ekind (Entity (Nam)) = E_Function;
909 elsif Nkind (Nam) = N_Selected_Component then
910 return Ekind (Entity (Selector_Name (Nam))) = E_Function;
915 end Name_Denotes_Function;
917 -----------------------
918 -- No_Interpretation --
919 -----------------------
921 procedure No_Interpretation is
922 L : constant Boolean := Is_List_Member (N);
923 K : constant Node_Kind := Nkind (Parent (N));
926 -- If the node is in a list whose parent is not an expression then it
927 -- must be an attempted procedure call.
929 if L and then K not in N_Subexpr then
930 if Ekind (Entity (Nam)) = E_Generic_Procedure then
932 ("must instantiate generic procedure& before call",
936 ("procedure or entry name expected", Nam);
939 -- Check for tasking cases where only an entry call will do
942 and then Nkind_In (K, N_Entry_Call_Alternative,
943 N_Triggering_Alternative)
945 Error_Msg_N ("entry name expected", Nam);
947 -- Otherwise give general error message
950 Error_Msg_N ("invalid prefix in call", Nam);
952 end No_Interpretation;
954 -- Start of processing for Analyze_Call
957 if Restriction_Check_Required (SPARK) then
958 Check_Mixed_Parameter_And_Named_Associations;
961 -- Initialize the type of the result of the call to the error type,
962 -- which will be reset if the type is successfully resolved.
964 Set_Etype (N, Any_Type);
968 if not Is_Overloaded (Nam) then
970 -- Only one interpretation to check
972 if Ekind (Etype (Nam)) = E_Subprogram_Type then
973 Nam_Ent := Etype (Nam);
975 -- If the prefix is an access_to_subprogram, this may be an indirect
976 -- call. This is the case if the name in the call is not an entity
977 -- name, or if it is a function name in the context of a procedure
978 -- call. In this latter case, we have a call to a parameterless
979 -- function that returns a pointer_to_procedure which is the entity
980 -- being called. Finally, F (X) may be a call to a parameterless
981 -- function that returns a pointer to a function with parameters.
983 elsif Is_Access_Type (Etype (Nam))
984 and then Ekind (Designated_Type (Etype (Nam))) = E_Subprogram_Type
986 (not Name_Denotes_Function
987 or else Nkind (N) = N_Procedure_Call_Statement
989 (Nkind (Parent (N)) /= N_Explicit_Dereference
990 and then Is_Entity_Name (Nam)
991 and then No (First_Formal (Entity (Nam)))
992 and then Present (Actuals)))
994 Nam_Ent := Designated_Type (Etype (Nam));
995 Insert_Explicit_Dereference (Nam);
997 -- Selected component case. Simple entry or protected operation,
998 -- where the entry name is given by the selector name.
1000 elsif Nkind (Nam) = N_Selected_Component then
1001 Nam_Ent := Entity (Selector_Name (Nam));
1003 if not Ekind_In (Nam_Ent, E_Entry,
1008 Error_Msg_N ("name in call is not a callable entity", Nam);
1009 Set_Etype (N, Any_Type);
1013 -- If the name is an Indexed component, it can be a call to a member
1014 -- of an entry family. The prefix must be a selected component whose
1015 -- selector is the entry. Analyze_Procedure_Call normalizes several
1016 -- kinds of call into this form.
1018 elsif Nkind (Nam) = N_Indexed_Component then
1019 if Nkind (Prefix (Nam)) = N_Selected_Component then
1020 Nam_Ent := Entity (Selector_Name (Prefix (Nam)));
1022 Error_Msg_N ("name in call is not a callable entity", Nam);
1023 Set_Etype (N, Any_Type);
1027 elsif not Is_Entity_Name (Nam) then
1028 Error_Msg_N ("name in call is not a callable entity", Nam);
1029 Set_Etype (N, Any_Type);
1033 Nam_Ent := Entity (Nam);
1035 -- If no interpretations, give error message
1037 if not Is_Overloadable (Nam_Ent) then
1043 -- Operations generated for RACW stub types are called only through
1044 -- dispatching, and can never be the static interpretation of a call.
1046 if Is_RACW_Stub_Type_Operation (Nam_Ent) then
1051 Analyze_One_Call (N, Nam_Ent, True, Success);
1053 -- If this is an indirect call, the return type of the access_to
1054 -- subprogram may be an incomplete type. At the point of the call,
1055 -- use the full type if available, and at the same time update the
1056 -- return type of the access_to_subprogram.
1059 and then Nkind (Nam) = N_Explicit_Dereference
1060 and then Ekind (Etype (N)) = E_Incomplete_Type
1061 and then Present (Full_View (Etype (N)))
1063 Set_Etype (N, Full_View (Etype (N)));
1064 Set_Etype (Nam_Ent, Etype (N));
1068 -- An overloaded selected component must denote overloaded operations
1069 -- of a concurrent type. The interpretations are attached to the
1070 -- simple name of those operations.
1072 if Nkind (Nam) = N_Selected_Component then
1073 Nam := Selector_Name (Nam);
1076 Get_First_Interp (Nam, X, It);
1078 while Present (It.Nam) loop
1082 -- Name may be call that returns an access to subprogram, or more
1083 -- generally an overloaded expression one of whose interpretations
1084 -- yields an access to subprogram. If the name is an entity, we do
1085 -- not dereference, because the node is a call that returns the
1086 -- access type: note difference between f(x), where the call may
1087 -- return an access subprogram type, and f(x)(y), where the type
1088 -- returned by the call to f is implicitly dereferenced to analyze
1091 if Is_Access_Type (Nam_Ent) then
1092 Nam_Ent := Designated_Type (Nam_Ent);
1094 elsif Is_Access_Type (Etype (Nam_Ent))
1096 (not Is_Entity_Name (Nam)
1097 or else Nkind (N) = N_Procedure_Call_Statement)
1098 and then Ekind (Designated_Type (Etype (Nam_Ent)))
1101 Nam_Ent := Designated_Type (Etype (Nam_Ent));
1103 if Is_Entity_Name (Nam) then
1108 -- If the call has been rewritten from a prefixed call, the first
1109 -- parameter has been analyzed, but may need a subsequent
1110 -- dereference, so skip its analysis now.
1112 if N /= Original_Node (N)
1113 and then Nkind (Original_Node (N)) = Nkind (N)
1114 and then Nkind (Name (N)) /= Nkind (Name (Original_Node (N)))
1115 and then Present (Parameter_Associations (N))
1116 and then Present (Etype (First (Parameter_Associations (N))))
1119 (N, Nam_Ent, False, Success, Skip_First => True);
1121 Analyze_One_Call (N, Nam_Ent, False, Success);
1124 -- If the interpretation succeeds, mark the proper type of the
1125 -- prefix (any valid candidate will do). If not, remove the
1126 -- candidate interpretation. This only needs to be done for
1127 -- overloaded protected operations, for other entities disambi-
1128 -- guation is done directly in Resolve.
1132 and then Nkind (Parent (N)) /= N_Explicit_Dereference
1134 Set_Entity (Nam, It.Nam);
1135 Insert_Explicit_Dereference (Nam);
1136 Set_Etype (Nam, Nam_Ent);
1139 Set_Etype (Nam, It.Typ);
1142 elsif Nkind_In (Name (N), N_Selected_Component,
1148 Get_Next_Interp (X, It);
1151 -- If the name is the result of a function call, it can only
1152 -- be a call to a function returning an access to subprogram.
1153 -- Insert explicit dereference.
1155 if Nkind (Nam) = N_Function_Call then
1156 Insert_Explicit_Dereference (Nam);
1159 if Etype (N) = Any_Type then
1161 -- None of the interpretations is compatible with the actuals
1163 Diagnose_Call (N, Nam);
1165 -- Special checks for uninstantiated put routines
1167 if Nkind (N) = N_Procedure_Call_Statement
1168 and then Is_Entity_Name (Nam)
1169 and then Chars (Nam) = Name_Put
1170 and then List_Length (Actuals) = 1
1173 Arg : constant Node_Id := First (Actuals);
1177 if Nkind (Arg) = N_Parameter_Association then
1178 Typ := Etype (Explicit_Actual_Parameter (Arg));
1183 if Is_Signed_Integer_Type (Typ) then
1185 ("possible missing instantiation of " &
1186 "'Text_'I'O.'Integer_'I'O!", Nam);
1188 elsif Is_Modular_Integer_Type (Typ) then
1190 ("possible missing instantiation of " &
1191 "'Text_'I'O.'Modular_'I'O!", Nam);
1193 elsif Is_Floating_Point_Type (Typ) then
1195 ("possible missing instantiation of " &
1196 "'Text_'I'O.'Float_'I'O!", Nam);
1198 elsif Is_Ordinary_Fixed_Point_Type (Typ) then
1200 ("possible missing instantiation of " &
1201 "'Text_'I'O.'Fixed_'I'O!", Nam);
1203 elsif Is_Decimal_Fixed_Point_Type (Typ) then
1205 ("possible missing instantiation of " &
1206 "'Text_'I'O.'Decimal_'I'O!", Nam);
1208 elsif Is_Enumeration_Type (Typ) then
1210 ("possible missing instantiation of " &
1211 "'Text_'I'O.'Enumeration_'I'O!", Nam);
1216 elsif not Is_Overloaded (N)
1217 and then Is_Entity_Name (Nam)
1219 -- Resolution yields a single interpretation. Verify that the
1220 -- reference has capitalization consistent with the declaration.
1222 Set_Entity_With_Style_Check (Nam, Entity (Nam));
1223 Generate_Reference (Entity (Nam), Nam);
1225 Set_Etype (Nam, Etype (Entity (Nam)));
1227 Remove_Abstract_Operations (N);
1234 -----------------------------
1235 -- Analyze_Case_Expression --
1236 -----------------------------
1238 procedure Analyze_Case_Expression (N : Node_Id) is
1239 Expr : constant Node_Id := Expression (N);
1240 FirstX : constant Node_Id := Expression (First (Alternatives (N)));
1242 Exp_Type : Entity_Id;
1243 Exp_Btype : Entity_Id;
1245 Dont_Care : Boolean;
1246 Others_Present : Boolean;
1248 procedure Non_Static_Choice_Error (Choice : Node_Id);
1249 -- Error routine invoked by the generic instantiation below when
1250 -- the case expression has a non static choice.
1252 package Case_Choices_Processing is new
1253 Generic_Choices_Processing
1254 (Get_Alternatives => Alternatives,
1255 Get_Choices => Discrete_Choices,
1256 Process_Empty_Choice => No_OP,
1257 Process_Non_Static_Choice => Non_Static_Choice_Error,
1258 Process_Associated_Node => No_OP);
1259 use Case_Choices_Processing;
1261 -----------------------------
1262 -- Non_Static_Choice_Error --
1263 -----------------------------
1265 procedure Non_Static_Choice_Error (Choice : Node_Id) is
1267 Flag_Non_Static_Expr
1268 ("choice given in case expression is not static!", Choice);
1269 end Non_Static_Choice_Error;
1271 -- Start of processing for Analyze_Case_Expression
1274 if Comes_From_Source (N) then
1275 Check_Compiler_Unit (N);
1278 Analyze_And_Resolve (Expr, Any_Discrete);
1279 Check_Unset_Reference (Expr);
1280 Exp_Type := Etype (Expr);
1281 Exp_Btype := Base_Type (Exp_Type);
1283 Alt := First (Alternatives (N));
1284 while Present (Alt) loop
1285 Analyze (Expression (Alt));
1289 if not Is_Overloaded (FirstX) then
1290 Set_Etype (N, Etype (FirstX));
1298 Set_Etype (N, Any_Type);
1300 Get_First_Interp (FirstX, I, It);
1301 while Present (It.Nam) loop
1303 -- For each interpretation of the first expression, we only
1304 -- add the interpretation if every other expression in the
1305 -- case expression alternatives has a compatible type.
1307 Alt := Next (First (Alternatives (N)));
1308 while Present (Alt) loop
1309 exit when not Has_Compatible_Type (Expression (Alt), It.Typ);
1314 Add_One_Interp (N, It.Typ, It.Typ);
1317 Get_Next_Interp (I, It);
1322 Exp_Btype := Base_Type (Exp_Type);
1324 -- The expression must be of a discrete type which must be determinable
1325 -- independently of the context in which the expression occurs, but
1326 -- using the fact that the expression must be of a discrete type.
1327 -- Moreover, the type this expression must not be a character literal
1328 -- (which is always ambiguous).
1330 -- If error already reported by Resolve, nothing more to do
1332 if Exp_Btype = Any_Discrete
1333 or else Exp_Btype = Any_Type
1337 elsif Exp_Btype = Any_Character then
1339 ("character literal as case expression is ambiguous", Expr);
1343 -- If the case expression is a formal object of mode in out, then
1344 -- treat it as having a nonstatic subtype by forcing use of the base
1345 -- type (which has to get passed to Check_Case_Choices below). Also
1346 -- use base type when the case expression is parenthesized.
1348 if Paren_Count (Expr) > 0
1349 or else (Is_Entity_Name (Expr)
1350 and then Ekind (Entity (Expr)) = E_Generic_In_Out_Parameter)
1352 Exp_Type := Exp_Btype;
1355 -- Call instantiated Analyze_Choices which does the rest of the work
1357 Analyze_Choices (N, Exp_Type, Dont_Care, Others_Present);
1359 if Exp_Type = Universal_Integer and then not Others_Present then
1361 ("case on universal integer requires OTHERS choice", Expr);
1363 end Analyze_Case_Expression;
1365 ---------------------------
1366 -- Analyze_Comparison_Op --
1367 ---------------------------
1369 procedure Analyze_Comparison_Op (N : Node_Id) is
1370 L : constant Node_Id := Left_Opnd (N);
1371 R : constant Node_Id := Right_Opnd (N);
1372 Op_Id : Entity_Id := Entity (N);
1375 Set_Etype (N, Any_Type);
1376 Candidate_Type := Empty;
1378 Analyze_Expression (L);
1379 Analyze_Expression (R);
1381 if Present (Op_Id) then
1382 if Ekind (Op_Id) = E_Operator then
1383 Find_Comparison_Types (L, R, Op_Id, N);
1385 Add_One_Interp (N, Op_Id, Etype (Op_Id));
1388 if Is_Overloaded (L) then
1389 Set_Etype (L, Intersect_Types (L, R));
1393 Op_Id := Get_Name_Entity_Id (Chars (N));
1394 while Present (Op_Id) loop
1395 if Ekind (Op_Id) = E_Operator then
1396 Find_Comparison_Types (L, R, Op_Id, N);
1398 Analyze_User_Defined_Binary_Op (N, Op_Id);
1401 Op_Id := Homonym (Op_Id);
1406 end Analyze_Comparison_Op;
1408 ---------------------------
1409 -- Analyze_Concatenation --
1410 ---------------------------
1412 procedure Analyze_Concatenation (N : Node_Id) is
1414 -- We wish to avoid deep recursion, because concatenations are often
1415 -- deeply nested, as in A&B&...&Z. Therefore, we walk down the left
1416 -- operands nonrecursively until we find something that is not a
1417 -- concatenation (A in this case), or has already been analyzed. We
1418 -- analyze that, and then walk back up the tree following Parent
1419 -- pointers, calling Analyze_Concatenation_Rest to do the rest of the
1420 -- work at each level. The Parent pointers allow us to avoid recursion,
1421 -- and thus avoid running out of memory.
1427 Candidate_Type := Empty;
1429 -- The following code is equivalent to:
1431 -- Set_Etype (N, Any_Type);
1432 -- Analyze_Expression (Left_Opnd (N));
1433 -- Analyze_Concatenation_Rest (N);
1435 -- where the Analyze_Expression call recurses back here if the left
1436 -- operand is a concatenation.
1438 -- Walk down left operands
1441 Set_Etype (NN, Any_Type);
1442 L := Left_Opnd (NN);
1443 exit when Nkind (L) /= N_Op_Concat or else Analyzed (L);
1447 -- Now (given the above example) NN is A&B and L is A
1449 -- First analyze L ...
1451 Analyze_Expression (L);
1453 -- ... then walk NN back up until we reach N (where we started), calling
1454 -- Analyze_Concatenation_Rest along the way.
1457 Analyze_Concatenation_Rest (NN);
1461 end Analyze_Concatenation;
1463 --------------------------------
1464 -- Analyze_Concatenation_Rest --
1465 --------------------------------
1467 -- If the only one-dimensional array type in scope is String,
1468 -- this is the resulting type of the operation. Otherwise there
1469 -- will be a concatenation operation defined for each user-defined
1470 -- one-dimensional array.
1472 procedure Analyze_Concatenation_Rest (N : Node_Id) is
1473 L : constant Node_Id := Left_Opnd (N);
1474 R : constant Node_Id := Right_Opnd (N);
1475 Op_Id : Entity_Id := Entity (N);
1480 Analyze_Expression (R);
1482 -- If the entity is present, the node appears in an instance, and
1483 -- denotes a predefined concatenation operation. The resulting type is
1484 -- obtained from the arguments when possible. If the arguments are
1485 -- aggregates, the array type and the concatenation type must be
1488 if Present (Op_Id) then
1489 if Ekind (Op_Id) = E_Operator then
1490 LT := Base_Type (Etype (L));
1491 RT := Base_Type (Etype (R));
1493 if Is_Array_Type (LT)
1494 and then (RT = LT or else RT = Base_Type (Component_Type (LT)))
1496 Add_One_Interp (N, Op_Id, LT);
1498 elsif Is_Array_Type (RT)
1499 and then LT = Base_Type (Component_Type (RT))
1501 Add_One_Interp (N, Op_Id, RT);
1503 -- If one operand is a string type or a user-defined array type,
1504 -- and the other is a literal, result is of the specific type.
1507 (Root_Type (LT) = Standard_String
1508 or else Scope (LT) /= Standard_Standard)
1509 and then Etype (R) = Any_String
1511 Add_One_Interp (N, Op_Id, LT);
1514 (Root_Type (RT) = Standard_String
1515 or else Scope (RT) /= Standard_Standard)
1516 and then Etype (L) = Any_String
1518 Add_One_Interp (N, Op_Id, RT);
1520 elsif not Is_Generic_Type (Etype (Op_Id)) then
1521 Add_One_Interp (N, Op_Id, Etype (Op_Id));
1524 -- Type and its operations must be visible
1526 Set_Entity (N, Empty);
1527 Analyze_Concatenation (N);
1531 Add_One_Interp (N, Op_Id, Etype (Op_Id));
1535 Op_Id := Get_Name_Entity_Id (Name_Op_Concat);
1536 while Present (Op_Id) loop
1537 if Ekind (Op_Id) = E_Operator then
1539 -- Do not consider operators declared in dead code, they can
1540 -- not be part of the resolution.
1542 if Is_Eliminated (Op_Id) then
1545 Find_Concatenation_Types (L, R, Op_Id, N);
1549 Analyze_User_Defined_Binary_Op (N, Op_Id);
1552 Op_Id := Homonym (Op_Id);
1557 end Analyze_Concatenation_Rest;
1559 ------------------------------------
1560 -- Analyze_Conditional_Expression --
1561 ------------------------------------
1563 procedure Analyze_Conditional_Expression (N : Node_Id) is
1564 Condition : constant Node_Id := First (Expressions (N));
1565 Then_Expr : constant Node_Id := Next (Condition);
1566 Else_Expr : Node_Id;
1569 -- Defend against error of missing expressions from previous error
1571 if No (Then_Expr) then
1575 Check_SPARK_Restriction ("conditional expression is not allowed", N);
1577 Else_Expr := Next (Then_Expr);
1579 if Comes_From_Source (N) then
1580 Check_Compiler_Unit (N);
1583 Analyze_Expression (Condition);
1584 Analyze_Expression (Then_Expr);
1586 if Present (Else_Expr) then
1587 Analyze_Expression (Else_Expr);
1590 -- If then expression not overloaded, then that decides the type
1592 if not Is_Overloaded (Then_Expr) then
1593 Set_Etype (N, Etype (Then_Expr));
1595 -- Case where then expression is overloaded
1603 Set_Etype (N, Any_Type);
1605 -- Shouldn't the following statement be down in the ELSE of the
1606 -- following loop? ???
1608 Get_First_Interp (Then_Expr, I, It);
1610 -- if no Else_Expression the conditional must be boolean
1612 if No (Else_Expr) then
1613 Set_Etype (N, Standard_Boolean);
1615 -- Else_Expression Present. For each possible intepretation of
1616 -- the Then_Expression, add it only if the Else_Expression has
1617 -- a compatible type.
1620 while Present (It.Nam) loop
1621 if Has_Compatible_Type (Else_Expr, It.Typ) then
1622 Add_One_Interp (N, It.Typ, It.Typ);
1625 Get_Next_Interp (I, It);
1630 end Analyze_Conditional_Expression;
1632 -------------------------
1633 -- Analyze_Equality_Op --
1634 -------------------------
1636 procedure Analyze_Equality_Op (N : Node_Id) is
1637 Loc : constant Source_Ptr := Sloc (N);
1638 L : constant Node_Id := Left_Opnd (N);
1639 R : constant Node_Id := Right_Opnd (N);
1643 Set_Etype (N, Any_Type);
1644 Candidate_Type := Empty;
1646 Analyze_Expression (L);
1647 Analyze_Expression (R);
1649 -- If the entity is set, the node is a generic instance with a non-local
1650 -- reference to the predefined operator or to a user-defined function.
1651 -- It can also be an inequality that is expanded into the negation of a
1652 -- call to a user-defined equality operator.
1654 -- For the predefined case, the result is Boolean, regardless of the
1655 -- type of the operands. The operands may even be limited, if they are
1656 -- generic actuals. If they are overloaded, label the left argument with
1657 -- the common type that must be present, or with the type of the formal
1658 -- of the user-defined function.
1660 if Present (Entity (N)) then
1661 Op_Id := Entity (N);
1663 if Ekind (Op_Id) = E_Operator then
1664 Add_One_Interp (N, Op_Id, Standard_Boolean);
1666 Add_One_Interp (N, Op_Id, Etype (Op_Id));
1669 if Is_Overloaded (L) then
1670 if Ekind (Op_Id) = E_Operator then
1671 Set_Etype (L, Intersect_Types (L, R));
1673 Set_Etype (L, Etype (First_Formal (Op_Id)));
1678 Op_Id := Get_Name_Entity_Id (Chars (N));
1679 while Present (Op_Id) loop
1680 if Ekind (Op_Id) = E_Operator then
1681 Find_Equality_Types (L, R, Op_Id, N);
1683 Analyze_User_Defined_Binary_Op (N, Op_Id);
1686 Op_Id := Homonym (Op_Id);
1690 -- If there was no match, and the operator is inequality, this may
1691 -- be a case where inequality has not been made explicit, as for
1692 -- tagged types. Analyze the node as the negation of an equality
1693 -- operation. This cannot be done earlier, because before analysis
1694 -- we cannot rule out the presence of an explicit inequality.
1696 if Etype (N) = Any_Type
1697 and then Nkind (N) = N_Op_Ne
1699 Op_Id := Get_Name_Entity_Id (Name_Op_Eq);
1700 while Present (Op_Id) loop
1701 if Ekind (Op_Id) = E_Operator then
1702 Find_Equality_Types (L, R, Op_Id, N);
1704 Analyze_User_Defined_Binary_Op (N, Op_Id);
1707 Op_Id := Homonym (Op_Id);
1710 if Etype (N) /= Any_Type then
1711 Op_Id := Entity (N);
1717 Left_Opnd => Left_Opnd (N),
1718 Right_Opnd => Right_Opnd (N))));
1720 Set_Entity (Right_Opnd (N), Op_Id);
1726 end Analyze_Equality_Op;
1728 ----------------------------------
1729 -- Analyze_Explicit_Dereference --
1730 ----------------------------------
1732 procedure Analyze_Explicit_Dereference (N : Node_Id) is
1733 Loc : constant Source_Ptr := Sloc (N);
1734 P : constant Node_Id := Prefix (N);
1740 function Is_Function_Type return Boolean;
1741 -- Check whether node may be interpreted as an implicit function call
1743 ----------------------
1744 -- Is_Function_Type --
1745 ----------------------
1747 function Is_Function_Type return Boolean is
1752 if not Is_Overloaded (N) then
1753 return Ekind (Base_Type (Etype (N))) = E_Subprogram_Type
1754 and then Etype (Base_Type (Etype (N))) /= Standard_Void_Type;
1757 Get_First_Interp (N, I, It);
1758 while Present (It.Nam) loop
1759 if Ekind (Base_Type (It.Typ)) /= E_Subprogram_Type
1760 or else Etype (Base_Type (It.Typ)) = Standard_Void_Type
1765 Get_Next_Interp (I, It);
1770 end Is_Function_Type;
1772 -- Start of processing for Analyze_Explicit_Dereference
1775 -- If source node, check SPARK restriction. We guard this with the
1776 -- source node check, because ???
1778 if Comes_From_Source (N) then
1779 Check_SPARK_Restriction ("explicit dereference is not allowed", N);
1782 -- In formal verification mode, keep track of all reads and writes
1783 -- through explicit dereferences.
1786 Alfa.Generate_Dereference (N);
1790 Set_Etype (N, Any_Type);
1792 -- Test for remote access to subprogram type, and if so return
1793 -- after rewriting the original tree.
1795 if Remote_AST_E_Dereference (P) then
1799 -- Normal processing for other than remote access to subprogram type
1801 if not Is_Overloaded (P) then
1802 if Is_Access_Type (Etype (P)) then
1804 -- Set the Etype. We need to go through Is_For_Access_Subtypes to
1805 -- avoid other problems caused by the Private_Subtype and it is
1806 -- safe to go to the Base_Type because this is the same as
1807 -- converting the access value to its Base_Type.
1810 DT : Entity_Id := Designated_Type (Etype (P));
1813 if Ekind (DT) = E_Private_Subtype
1814 and then Is_For_Access_Subtype (DT)
1816 DT := Base_Type (DT);
1819 -- An explicit dereference is a legal occurrence of an
1820 -- incomplete type imported through a limited_with clause,
1821 -- if the full view is visible.
1823 if From_With_Type (DT)
1824 and then not From_With_Type (Scope (DT))
1826 (Is_Immediately_Visible (Scope (DT))
1828 (Is_Child_Unit (Scope (DT))
1829 and then Is_Visible_Child_Unit (Scope (DT))))
1831 Set_Etype (N, Available_View (DT));
1838 elsif Etype (P) /= Any_Type then
1839 Error_Msg_N ("prefix of dereference must be an access type", N);
1844 Get_First_Interp (P, I, It);
1845 while Present (It.Nam) loop
1848 if Is_Access_Type (T) then
1849 Add_One_Interp (N, Designated_Type (T), Designated_Type (T));
1852 Get_Next_Interp (I, It);
1855 -- Error if no interpretation of the prefix has an access type
1857 if Etype (N) = Any_Type then
1859 ("access type required in prefix of explicit dereference", P);
1860 Set_Etype (N, Any_Type);
1866 and then Nkind (Parent (N)) /= N_Indexed_Component
1868 and then (Nkind (Parent (N)) /= N_Function_Call
1869 or else N /= Name (Parent (N)))
1871 and then (Nkind (Parent (N)) /= N_Procedure_Call_Statement
1872 or else N /= Name (Parent (N)))
1874 and then Nkind (Parent (N)) /= N_Subprogram_Renaming_Declaration
1875 and then (Nkind (Parent (N)) /= N_Attribute_Reference
1877 (Attribute_Name (Parent (N)) /= Name_Address
1879 Attribute_Name (Parent (N)) /= Name_Access))
1881 -- Name is a function call with no actuals, in a context that
1882 -- requires deproceduring (including as an actual in an enclosing
1883 -- function or procedure call). There are some pathological cases
1884 -- where the prefix might include functions that return access to
1885 -- subprograms and others that return a regular type. Disambiguation
1886 -- of those has to take place in Resolve.
1889 Make_Function_Call (Loc,
1890 Name => Make_Explicit_Dereference (Loc, P),
1891 Parameter_Associations => New_List);
1893 -- If the prefix is overloaded, remove operations that have formals,
1894 -- we know that this is a parameterless call.
1896 if Is_Overloaded (P) then
1897 Get_First_Interp (P, I, It);
1898 while Present (It.Nam) loop
1901 if No (First_Formal (Base_Type (Designated_Type (T)))) then
1907 Get_Next_Interp (I, It);
1914 elsif not Is_Function_Type
1915 and then Is_Overloaded (N)
1917 -- The prefix may include access to subprograms and other access
1918 -- types. If the context selects the interpretation that is a
1919 -- function call (not a procedure call) we cannot rewrite the node
1920 -- yet, but we include the result of the call interpretation.
1922 Get_First_Interp (N, I, It);
1923 while Present (It.Nam) loop
1924 if Ekind (Base_Type (It.Typ)) = E_Subprogram_Type
1925 and then Etype (Base_Type (It.Typ)) /= Standard_Void_Type
1926 and then Nkind (Parent (N)) /= N_Procedure_Call_Statement
1928 Add_One_Interp (N, Etype (It.Typ), Etype (It.Typ));
1931 Get_Next_Interp (I, It);
1935 -- A value of remote access-to-class-wide must not be dereferenced
1938 Validate_Remote_Access_To_Class_Wide_Type (N);
1939 end Analyze_Explicit_Dereference;
1941 ------------------------
1942 -- Analyze_Expression --
1943 ------------------------
1945 procedure Analyze_Expression (N : Node_Id) is
1948 Check_Parameterless_Call (N);
1949 end Analyze_Expression;
1951 -------------------------------------
1952 -- Analyze_Expression_With_Actions --
1953 -------------------------------------
1955 procedure Analyze_Expression_With_Actions (N : Node_Id) is
1959 A := First (Actions (N));
1966 Analyze_Expression (Expression (N));
1967 Set_Etype (N, Etype (Expression (N)));
1968 end Analyze_Expression_With_Actions;
1970 ------------------------------------
1971 -- Analyze_Indexed_Component_Form --
1972 ------------------------------------
1974 procedure Analyze_Indexed_Component_Form (N : Node_Id) is
1975 P : constant Node_Id := Prefix (N);
1976 Exprs : constant List_Id := Expressions (N);
1982 procedure Process_Function_Call;
1983 -- Prefix in indexed component form is an overloadable entity,
1984 -- so the node is a function call. Reformat it as such.
1986 procedure Process_Indexed_Component;
1987 -- Prefix in indexed component form is actually an indexed component.
1988 -- This routine processes it, knowing that the prefix is already
1991 procedure Process_Indexed_Component_Or_Slice;
1992 -- An indexed component with a single index may designate a slice if
1993 -- the index is a subtype mark. This routine disambiguates these two
1994 -- cases by resolving the prefix to see if it is a subtype mark.
1996 procedure Process_Overloaded_Indexed_Component;
1997 -- If the prefix of an indexed component is overloaded, the proper
1998 -- interpretation is selected by the index types and the context.
2000 ---------------------------
2001 -- Process_Function_Call --
2002 ---------------------------
2004 procedure Process_Function_Call is
2008 Change_Node (N, N_Function_Call);
2010 Set_Parameter_Associations (N, Exprs);
2012 -- Analyze actuals prior to analyzing the call itself
2014 Actual := First (Parameter_Associations (N));
2015 while Present (Actual) loop
2017 Check_Parameterless_Call (Actual);
2019 -- Move to next actual. Note that we use Next, not Next_Actual
2020 -- here. The reason for this is a bit subtle. If a function call
2021 -- includes named associations, the parser recognizes the node as
2022 -- a call, and it is analyzed as such. If all associations are
2023 -- positional, the parser builds an indexed_component node, and
2024 -- it is only after analysis of the prefix that the construct
2025 -- is recognized as a call, in which case Process_Function_Call
2026 -- rewrites the node and analyzes the actuals. If the list of
2027 -- actuals is malformed, the parser may leave the node as an
2028 -- indexed component (despite the presence of named associations).
2029 -- The iterator Next_Actual is equivalent to Next if the list is
2030 -- positional, but follows the normalized chain of actuals when
2031 -- named associations are present. In this case normalization has
2032 -- not taken place, and actuals remain unanalyzed, which leads to
2033 -- subsequent crashes or loops if there is an attempt to continue
2034 -- analysis of the program.
2040 end Process_Function_Call;
2042 -------------------------------
2043 -- Process_Indexed_Component --
2044 -------------------------------
2046 procedure Process_Indexed_Component is
2048 Array_Type : Entity_Id;
2050 Pent : Entity_Id := Empty;
2053 Exp := First (Exprs);
2055 if Is_Overloaded (P) then
2056 Process_Overloaded_Indexed_Component;
2059 Array_Type := Etype (P);
2061 if Is_Entity_Name (P) then
2063 elsif Nkind (P) = N_Selected_Component
2064 and then Is_Entity_Name (Selector_Name (P))
2066 Pent := Entity (Selector_Name (P));
2069 -- Prefix must be appropriate for an array type, taking into
2070 -- account a possible implicit dereference.
2072 if Is_Access_Type (Array_Type) then
2073 Error_Msg_NW (Warn_On_Dereference, "?implicit dereference", N);
2074 Array_Type := Process_Implicit_Dereference_Prefix (Pent, P);
2077 if Is_Array_Type (Array_Type) then
2080 elsif Present (Pent) and then Ekind (Pent) = E_Entry_Family then
2082 Set_Etype (N, Any_Type);
2084 if not Has_Compatible_Type
2085 (Exp, Entry_Index_Type (Pent))
2087 Error_Msg_N ("invalid index type in entry name", N);
2089 elsif Present (Next (Exp)) then
2090 Error_Msg_N ("too many subscripts in entry reference", N);
2093 Set_Etype (N, Etype (P));
2098 elsif Is_Record_Type (Array_Type)
2099 and then Remote_AST_I_Dereference (P)
2103 elsif Try_Container_Indexing (N, P, Exp) then
2106 elsif Array_Type = Any_Type then
2107 Set_Etype (N, Any_Type);
2109 -- In most cases the analysis of the prefix will have emitted
2110 -- an error already, but if the prefix may be interpreted as a
2111 -- call in prefixed notation, the report is left to the caller.
2112 -- To prevent cascaded errors, report only if no previous ones.
2114 if Serious_Errors_Detected = 0 then
2115 Error_Msg_N ("invalid prefix in indexed component", P);
2117 if Nkind (P) = N_Expanded_Name then
2118 Error_Msg_NE ("\& is not visible", P, Selector_Name (P));
2124 -- Here we definitely have a bad indexing
2127 if Nkind (Parent (N)) = N_Requeue_Statement
2128 and then Present (Pent) and then Ekind (Pent) = E_Entry
2131 ("REQUEUE does not permit parameters", First (Exprs));
2133 elsif Is_Entity_Name (P)
2134 and then Etype (P) = Standard_Void_Type
2136 Error_Msg_NE ("incorrect use of&", P, Entity (P));
2139 Error_Msg_N ("array type required in indexed component", P);
2142 Set_Etype (N, Any_Type);
2146 Index := First_Index (Array_Type);
2147 while Present (Index) and then Present (Exp) loop
2148 if not Has_Compatible_Type (Exp, Etype (Index)) then
2149 Wrong_Type (Exp, Etype (Index));
2150 Set_Etype (N, Any_Type);
2158 Set_Etype (N, Component_Type (Array_Type));
2159 Check_Implicit_Dereference (N, Etype (N));
2161 if Present (Index) then
2163 ("too few subscripts in array reference", First (Exprs));
2165 elsif Present (Exp) then
2166 Error_Msg_N ("too many subscripts in array reference", Exp);
2169 end Process_Indexed_Component;
2171 ----------------------------------------
2172 -- Process_Indexed_Component_Or_Slice --
2173 ----------------------------------------
2175 procedure Process_Indexed_Component_Or_Slice is
2177 Exp := First (Exprs);
2178 while Present (Exp) loop
2179 Analyze_Expression (Exp);
2183 Exp := First (Exprs);
2185 -- If one index is present, and it is a subtype name, then the
2186 -- node denotes a slice (note that the case of an explicit range
2187 -- for a slice was already built as an N_Slice node in the first
2188 -- place, so that case is not handled here).
2190 -- We use a replace rather than a rewrite here because this is one
2191 -- of the cases in which the tree built by the parser is plain wrong.
2194 and then Is_Entity_Name (Exp)
2195 and then Is_Type (Entity (Exp))
2198 Make_Slice (Sloc (N),
2200 Discrete_Range => New_Copy (Exp)));
2203 -- Otherwise (more than one index present, or single index is not
2204 -- a subtype name), then we have the indexed component case.
2207 Process_Indexed_Component;
2209 end Process_Indexed_Component_Or_Slice;
2211 ------------------------------------------
2212 -- Process_Overloaded_Indexed_Component --
2213 ------------------------------------------
2215 procedure Process_Overloaded_Indexed_Component is
2224 Set_Etype (N, Any_Type);
2226 Get_First_Interp (P, I, It);
2227 while Present (It.Nam) loop
2230 if Is_Access_Type (Typ) then
2231 Typ := Designated_Type (Typ);
2232 Error_Msg_NW (Warn_On_Dereference, "?implicit dereference", N);
2235 if Is_Array_Type (Typ) then
2237 -- Got a candidate: verify that index types are compatible
2239 Index := First_Index (Typ);
2241 Exp := First (Exprs);
2242 while Present (Index) and then Present (Exp) loop
2243 if Has_Compatible_Type (Exp, Etype (Index)) then
2255 if Found and then No (Index) and then No (Exp) then
2257 CT : constant Entity_Id :=
2258 Base_Type (Component_Type (Typ));
2260 Add_One_Interp (N, CT, CT);
2261 Check_Implicit_Dereference (N, CT);
2265 elsif Try_Container_Indexing (N, P, First (Exprs)) then
2270 Get_Next_Interp (I, It);
2273 if Etype (N) = Any_Type then
2274 Error_Msg_N ("no legal interpretation for indexed component", N);
2275 Set_Is_Overloaded (N, False);
2279 end Process_Overloaded_Indexed_Component;
2281 -- Start of processing for Analyze_Indexed_Component_Form
2284 -- Get name of array, function or type
2288 if Nkind_In (N, N_Function_Call, N_Procedure_Call_Statement) then
2290 -- If P is an explicit dereference whose prefix is of a
2291 -- remote access-to-subprogram type, then N has already
2292 -- been rewritten as a subprogram call and analyzed.
2297 pragma Assert (Nkind (N) = N_Indexed_Component);
2299 P_T := Base_Type (Etype (P));
2301 if Is_Entity_Name (P) and then Present (Entity (P)) then
2304 if Is_Type (U_N) then
2306 -- Reformat node as a type conversion
2308 E := Remove_Head (Exprs);
2310 if Present (First (Exprs)) then
2312 ("argument of type conversion must be single expression", N);
2315 Change_Node (N, N_Type_Conversion);
2316 Set_Subtype_Mark (N, P);
2318 Set_Expression (N, E);
2320 -- After changing the node, call for the specific Analysis
2321 -- routine directly, to avoid a double call to the expander.
2323 Analyze_Type_Conversion (N);
2327 if Is_Overloadable (U_N) then
2328 Process_Function_Call;
2330 elsif Ekind (Etype (P)) = E_Subprogram_Type
2331 or else (Is_Access_Type (Etype (P))
2333 Ekind (Designated_Type (Etype (P))) =
2336 -- Call to access_to-subprogram with possible implicit dereference
2338 Process_Function_Call;
2340 elsif Is_Generic_Subprogram (U_N) then
2342 -- A common beginner's (or C++ templates fan) error
2344 Error_Msg_N ("generic subprogram cannot be called", N);
2345 Set_Etype (N, Any_Type);
2349 Process_Indexed_Component_Or_Slice;
2352 -- If not an entity name, prefix is an expression that may denote
2353 -- an array or an access-to-subprogram.
2356 if Ekind (P_T) = E_Subprogram_Type
2357 or else (Is_Access_Type (P_T)
2359 Ekind (Designated_Type (P_T)) = E_Subprogram_Type)
2361 Process_Function_Call;
2363 elsif Nkind (P) = N_Selected_Component
2364 and then Is_Overloadable (Entity (Selector_Name (P)))
2366 Process_Function_Call;
2369 -- Indexed component, slice, or a call to a member of a family
2370 -- entry, which will be converted to an entry call later.
2372 Process_Indexed_Component_Or_Slice;
2375 end Analyze_Indexed_Component_Form;
2377 ------------------------
2378 -- Analyze_Logical_Op --
2379 ------------------------
2381 procedure Analyze_Logical_Op (N : Node_Id) is
2382 L : constant Node_Id := Left_Opnd (N);
2383 R : constant Node_Id := Right_Opnd (N);
2384 Op_Id : Entity_Id := Entity (N);
2387 Set_Etype (N, Any_Type);
2388 Candidate_Type := Empty;
2390 Analyze_Expression (L);
2391 Analyze_Expression (R);
2393 if Present (Op_Id) then
2395 if Ekind (Op_Id) = E_Operator then
2396 Find_Boolean_Types (L, R, Op_Id, N);
2398 Add_One_Interp (N, Op_Id, Etype (Op_Id));
2402 Op_Id := Get_Name_Entity_Id (Chars (N));
2403 while Present (Op_Id) loop
2404 if Ekind (Op_Id) = E_Operator then
2405 Find_Boolean_Types (L, R, Op_Id, N);
2407 Analyze_User_Defined_Binary_Op (N, Op_Id);
2410 Op_Id := Homonym (Op_Id);
2415 end Analyze_Logical_Op;
2417 ---------------------------
2418 -- Analyze_Membership_Op --
2419 ---------------------------
2421 procedure Analyze_Membership_Op (N : Node_Id) is
2422 Loc : constant Source_Ptr := Sloc (N);
2423 L : constant Node_Id := Left_Opnd (N);
2424 R : constant Node_Id := Right_Opnd (N);
2426 Index : Interp_Index;
2428 Found : Boolean := False;
2432 procedure Try_One_Interp (T1 : Entity_Id);
2433 -- Routine to try one proposed interpretation. Note that the context
2434 -- of the operation plays no role in resolving the arguments, so that
2435 -- if there is more than one interpretation of the operands that is
2436 -- compatible with a membership test, the operation is ambiguous.
2438 --------------------
2439 -- Try_One_Interp --
2440 --------------------
2442 procedure Try_One_Interp (T1 : Entity_Id) is
2444 if Has_Compatible_Type (R, T1) then
2446 and then Base_Type (T1) /= Base_Type (T_F)
2448 It := Disambiguate (L, I_F, Index, Any_Type);
2450 if It = No_Interp then
2451 Ambiguous_Operands (N);
2452 Set_Etype (L, Any_Type);
2469 procedure Analyze_Set_Membership;
2470 -- If a set of alternatives is present, analyze each and find the
2471 -- common type to which they must all resolve.
2473 ----------------------------
2474 -- Analyze_Set_Membership --
2475 ----------------------------
2477 procedure Analyze_Set_Membership is
2479 Index : Interp_Index;
2481 Candidate_Interps : Node_Id;
2482 Common_Type : Entity_Id := Empty;
2486 Candidate_Interps := L;
2488 if not Is_Overloaded (L) then
2489 Common_Type := Etype (L);
2491 Alt := First (Alternatives (N));
2492 while Present (Alt) loop
2495 if not Has_Compatible_Type (Alt, Common_Type) then
2496 Wrong_Type (Alt, Common_Type);
2503 Alt := First (Alternatives (N));
2504 while Present (Alt) loop
2506 if not Is_Overloaded (Alt) then
2507 Common_Type := Etype (Alt);
2510 Get_First_Interp (Alt, Index, It);
2511 while Present (It.Typ) loop
2513 Has_Compatible_Type (Candidate_Interps, It.Typ)
2515 Remove_Interp (Index);
2518 Get_Next_Interp (Index, It);
2521 Get_First_Interp (Alt, Index, It);
2524 Error_Msg_N ("alternative has no legal type", Alt);
2528 -- If alternative is not overloaded, we have a unique type
2531 Set_Etype (Alt, It.Typ);
2532 Get_Next_Interp (Index, It);
2535 Set_Is_Overloaded (Alt, False);
2536 Common_Type := Etype (Alt);
2539 Candidate_Interps := Alt;
2546 Set_Etype (N, Standard_Boolean);
2548 if Present (Common_Type) then
2549 Set_Etype (L, Common_Type);
2550 Set_Is_Overloaded (L, False);
2553 Error_Msg_N ("cannot resolve membership operation", N);
2555 end Analyze_Set_Membership;
2557 -- Start of processing for Analyze_Membership_Op
2560 Analyze_Expression (L);
2563 and then Ada_Version >= Ada_2012
2565 Analyze_Set_Membership;
2569 if Nkind (R) = N_Range
2570 or else (Nkind (R) = N_Attribute_Reference
2571 and then Attribute_Name (R) = Name_Range)
2575 if not Is_Overloaded (L) then
2576 Try_One_Interp (Etype (L));
2579 Get_First_Interp (L, Index, It);
2580 while Present (It.Typ) loop
2581 Try_One_Interp (It.Typ);
2582 Get_Next_Interp (Index, It);
2586 -- If not a range, it can be a subtype mark, or else it is a degenerate
2587 -- membership test with a singleton value, i.e. a test for equality,
2588 -- if the types are compatible.
2593 if Is_Entity_Name (R)
2594 and then Is_Type (Entity (R))
2597 Check_Fully_Declared (Entity (R), R);
2599 elsif Ada_Version >= Ada_2012
2600 and then Has_Compatible_Type (R, Etype (L))
2602 if Nkind (N) = N_In then
2618 -- In all versions of the language, if we reach this point there
2619 -- is a previous error that will be diagnosed below.
2625 -- Compatibility between expression and subtype mark or range is
2626 -- checked during resolution. The result of the operation is Boolean
2629 Set_Etype (N, Standard_Boolean);
2631 if Comes_From_Source (N)
2632 and then Present (Right_Opnd (N))
2633 and then Is_CPP_Class (Etype (Etype (Right_Opnd (N))))
2635 Error_Msg_N ("membership test not applicable to cpp-class types", N);
2637 end Analyze_Membership_Op;
2639 ----------------------
2640 -- Analyze_Negation --
2641 ----------------------
2643 procedure Analyze_Negation (N : Node_Id) is
2644 R : constant Node_Id := Right_Opnd (N);
2645 Op_Id : Entity_Id := Entity (N);
2648 Set_Etype (N, Any_Type);
2649 Candidate_Type := Empty;
2651 Analyze_Expression (R);
2653 if Present (Op_Id) then
2654 if Ekind (Op_Id) = E_Operator then
2655 Find_Negation_Types (R, Op_Id, N);
2657 Add_One_Interp (N, Op_Id, Etype (Op_Id));
2661 Op_Id := Get_Name_Entity_Id (Chars (N));
2662 while Present (Op_Id) loop
2663 if Ekind (Op_Id) = E_Operator then
2664 Find_Negation_Types (R, Op_Id, N);
2666 Analyze_User_Defined_Unary_Op (N, Op_Id);
2669 Op_Id := Homonym (Op_Id);
2674 end Analyze_Negation;
2680 procedure Analyze_Null (N : Node_Id) is
2682 Check_SPARK_Restriction ("null is not allowed", N);
2684 Set_Etype (N, Any_Access);
2687 ----------------------
2688 -- Analyze_One_Call --
2689 ----------------------
2691 procedure Analyze_One_Call
2695 Success : out Boolean;
2696 Skip_First : Boolean := False)
2698 Actuals : constant List_Id := Parameter_Associations (N);
2699 Prev_T : constant Entity_Id := Etype (N);
2701 Must_Skip : constant Boolean := Skip_First
2702 or else Nkind (Original_Node (N)) = N_Selected_Component
2704 (Nkind (Original_Node (N)) = N_Indexed_Component
2705 and then Nkind (Prefix (Original_Node (N)))
2706 = N_Selected_Component);
2707 -- The first formal must be omitted from the match when trying to find
2708 -- a primitive operation that is a possible interpretation, and also
2709 -- after the call has been rewritten, because the corresponding actual
2710 -- is already known to be compatible, and because this may be an
2711 -- indexing of a call with default parameters.
2715 Is_Indexed : Boolean := False;
2716 Is_Indirect : Boolean := False;
2717 Subp_Type : constant Entity_Id := Etype (Nam);
2720 function Operator_Hidden_By (Fun : Entity_Id) return Boolean;
2721 -- There may be a user-defined operator that hides the current
2722 -- interpretation. We must check for this independently of the
2723 -- analysis of the call with the user-defined operation, because
2724 -- the parameter names may be wrong and yet the hiding takes place.
2725 -- This fixes a problem with ACATS test B34014O.
2727 -- When the type Address is a visible integer type, and the DEC
2728 -- system extension is visible, the predefined operator may be
2729 -- hidden as well, by one of the address operations in auxdec.
2730 -- Finally, The abstract operations on address do not hide the
2731 -- predefined operator (this is the purpose of making them abstract).
2733 procedure Indicate_Name_And_Type;
2734 -- If candidate interpretation matches, indicate name and type of
2735 -- result on call node.
2737 ----------------------------
2738 -- Indicate_Name_And_Type --
2739 ----------------------------
2741 procedure Indicate_Name_And_Type is
2743 Add_One_Interp (N, Nam, Etype (Nam));
2744 Check_Implicit_Dereference (N, Etype (Nam));
2747 -- If the prefix of the call is a name, indicate the entity
2748 -- being called. If it is not a name, it is an expression that
2749 -- denotes an access to subprogram or else an entry or family. In
2750 -- the latter case, the name is a selected component, and the entity
2751 -- being called is noted on the selector.
2753 if not Is_Type (Nam) then
2754 if Is_Entity_Name (Name (N)) then
2755 Set_Entity (Name (N), Nam);
2757 elsif Nkind (Name (N)) = N_Selected_Component then
2758 Set_Entity (Selector_Name (Name (N)), Nam);
2762 if Debug_Flag_E and not Report then
2763 Write_Str (" Overloaded call ");
2764 Write_Int (Int (N));
2765 Write_Str (" compatible with ");
2766 Write_Int (Int (Nam));
2769 end Indicate_Name_And_Type;
2771 ------------------------
2772 -- Operator_Hidden_By --
2773 ------------------------
2775 function Operator_Hidden_By (Fun : Entity_Id) return Boolean is
2776 Act1 : constant Node_Id := First_Actual (N);
2777 Act2 : constant Node_Id := Next_Actual (Act1);
2778 Form1 : constant Entity_Id := First_Formal (Fun);
2779 Form2 : constant Entity_Id := Next_Formal (Form1);
2782 if Ekind (Fun) /= E_Function
2783 or else Is_Abstract_Subprogram (Fun)
2787 elsif not Has_Compatible_Type (Act1, Etype (Form1)) then
2790 elsif Present (Form2) then
2792 No (Act2) or else not Has_Compatible_Type (Act2, Etype (Form2))
2797 elsif Present (Act2) then
2801 -- Now we know that the arity of the operator matches the function,
2802 -- and the function call is a valid interpretation. The function
2803 -- hides the operator if it has the right signature, or if one of
2804 -- its operands is a non-abstract operation on Address when this is
2805 -- a visible integer type.
2807 return Hides_Op (Fun, Nam)
2808 or else Is_Descendent_Of_Address (Etype (Form1))
2811 and then Is_Descendent_Of_Address (Etype (Form2)));
2812 end Operator_Hidden_By;
2814 -- Start of processing for Analyze_One_Call
2819 -- If the subprogram has no formals or if all the formals have defaults,
2820 -- and the return type is an array type, the node may denote an indexing
2821 -- of the result of a parameterless call. In Ada 2005, the subprogram
2822 -- may have one non-defaulted formal, and the call may have been written
2823 -- in prefix notation, so that the rebuilt parameter list has more than
2826 if not Is_Overloadable (Nam)
2827 and then Ekind (Nam) /= E_Subprogram_Type
2828 and then Ekind (Nam) /= E_Entry_Family
2833 -- An indexing requires at least one actual
2835 if not Is_Empty_List (Actuals)
2837 (Needs_No_Actuals (Nam)
2839 (Needs_One_Actual (Nam)
2840 and then Present (Next_Actual (First (Actuals)))))
2842 if Is_Array_Type (Subp_Type) then
2843 Is_Indexed := Try_Indexed_Call (N, Nam, Subp_Type, Must_Skip);
2845 elsif Is_Access_Type (Subp_Type)
2846 and then Is_Array_Type (Designated_Type (Subp_Type))
2850 (N, Nam, Designated_Type (Subp_Type), Must_Skip);
2852 -- The prefix can also be a parameterless function that returns an
2853 -- access to subprogram, in which case this is an indirect call.
2854 -- If this succeeds, an explicit dereference is added later on,
2855 -- in Analyze_Call or Resolve_Call.
2857 elsif Is_Access_Type (Subp_Type)
2858 and then Ekind (Designated_Type (Subp_Type)) = E_Subprogram_Type
2860 Is_Indirect := Try_Indirect_Call (N, Nam, Subp_Type);
2865 -- If the call has been transformed into a slice, it is of the form
2866 -- F (Subtype) where F is parameterless. The node has been rewritten in
2867 -- Try_Indexed_Call and there is nothing else to do.
2870 and then Nkind (N) = N_Slice
2876 (N, Nam, (Report and not Is_Indexed and not Is_Indirect), Norm_OK);
2880 -- If an indirect call is a possible interpretation, indicate
2881 -- success to the caller.
2887 -- Mismatch in number or names of parameters
2889 elsif Debug_Flag_E then
2890 Write_Str (" normalization fails in call ");
2891 Write_Int (Int (N));
2892 Write_Str (" with subprogram ");
2893 Write_Int (Int (Nam));
2897 -- If the context expects a function call, discard any interpretation
2898 -- that is a procedure. If the node is not overloaded, leave as is for
2899 -- better error reporting when type mismatch is found.
2901 elsif Nkind (N) = N_Function_Call
2902 and then Is_Overloaded (Name (N))
2903 and then Ekind (Nam) = E_Procedure
2907 -- Ditto for function calls in a procedure context
2909 elsif Nkind (N) = N_Procedure_Call_Statement
2910 and then Is_Overloaded (Name (N))
2911 and then Etype (Nam) /= Standard_Void_Type
2915 elsif No (Actuals) then
2917 -- If Normalize succeeds, then there are default parameters for
2920 Indicate_Name_And_Type;
2922 elsif Ekind (Nam) = E_Operator then
2923 if Nkind (N) = N_Procedure_Call_Statement then
2927 -- This can occur when the prefix of the call is an operator
2928 -- name or an expanded name whose selector is an operator name.
2930 Analyze_Operator_Call (N, Nam);
2932 if Etype (N) /= Prev_T then
2934 -- Check that operator is not hidden by a function interpretation
2936 if Is_Overloaded (Name (N)) then
2942 Get_First_Interp (Name (N), I, It);
2943 while Present (It.Nam) loop
2944 if Operator_Hidden_By (It.Nam) then
2945 Set_Etype (N, Prev_T);
2949 Get_Next_Interp (I, It);
2954 -- If operator matches formals, record its name on the call.
2955 -- If the operator is overloaded, Resolve will select the
2956 -- correct one from the list of interpretations. The call
2957 -- node itself carries the first candidate.
2959 Set_Entity (Name (N), Nam);
2962 elsif Report and then Etype (N) = Any_Type then
2963 Error_Msg_N ("incompatible arguments for operator", N);
2967 -- Normalize_Actuals has chained the named associations in the
2968 -- correct order of the formals.
2970 Actual := First_Actual (N);
2971 Formal := First_Formal (Nam);
2973 -- If we are analyzing a call rewritten from object notation, skip
2974 -- first actual, which may be rewritten later as an explicit
2978 Next_Actual (Actual);
2979 Next_Formal (Formal);
2982 while Present (Actual) and then Present (Formal) loop
2983 if Nkind (Parent (Actual)) /= N_Parameter_Association
2984 or else Chars (Selector_Name (Parent (Actual))) = Chars (Formal)
2986 -- The actual can be compatible with the formal, but we must
2987 -- also check that the context is not an address type that is
2988 -- visibly an integer type, as is the case in VMS_64. In this
2989 -- case the use of literals is illegal, except in the body of
2990 -- descendents of system, where arithmetic operations on
2991 -- address are of course used.
2993 if Has_Compatible_Type (Actual, Etype (Formal))
2995 (Etype (Actual) /= Universal_Integer
2996 or else not Is_Descendent_Of_Address (Etype (Formal))
2998 Is_Predefined_File_Name
2999 (Unit_File_Name (Get_Source_Unit (N))))
3001 Next_Actual (Actual);
3002 Next_Formal (Formal);
3005 if Debug_Flag_E then
3006 Write_Str (" type checking fails in call ");
3007 Write_Int (Int (N));
3008 Write_Str (" with formal ");
3009 Write_Int (Int (Formal));
3010 Write_Str (" in subprogram ");
3011 Write_Int (Int (Nam));
3015 if Report and not Is_Indexed and not Is_Indirect then
3017 -- Ada 2005 (AI-251): Complete the error notification
3018 -- to help new Ada 2005 users.
3020 if Is_Class_Wide_Type (Etype (Formal))
3021 and then Is_Interface (Etype (Etype (Formal)))
3022 and then not Interface_Present_In_Ancestor
3023 (Typ => Etype (Actual),
3024 Iface => Etype (Etype (Formal)))
3027 ("(Ada 2005) does not implement interface }",
3028 Actual, Etype (Etype (Formal)));
3031 Wrong_Type (Actual, Etype (Formal));
3033 if Nkind (Actual) = N_Op_Eq
3034 and then Nkind (Left_Opnd (Actual)) = N_Identifier
3036 Formal := First_Formal (Nam);
3037 while Present (Formal) loop
3038 if Chars (Left_Opnd (Actual)) = Chars (Formal) then
3039 Error_Msg_N -- CODEFIX
3040 ("possible misspelling of `='>`!", Actual);
3044 Next_Formal (Formal);
3048 if All_Errors_Mode then
3049 Error_Msg_Sloc := Sloc (Nam);
3051 if Etype (Formal) = Any_Type then
3053 ("there is no legal actual parameter", Actual);
3056 if Is_Overloadable (Nam)
3057 and then Present (Alias (Nam))
3058 and then not Comes_From_Source (Nam)
3061 ("\\ =='> in call to inherited operation & #!",
3064 elsif Ekind (Nam) = E_Subprogram_Type then
3066 Access_To_Subprogram_Typ :
3067 constant Entity_Id :=
3069 (Associated_Node_For_Itype (Nam));
3072 "\\ =='> in call to dereference of &#!",
3073 Actual, Access_To_Subprogram_Typ);
3078 ("\\ =='> in call to &#!", Actual, Nam);
3088 -- Normalize_Actuals has verified that a default value exists
3089 -- for this formal. Current actual names a subsequent formal.
3091 Next_Formal (Formal);
3095 -- On exit, all actuals match
3097 Indicate_Name_And_Type;
3099 end Analyze_One_Call;
3101 ---------------------------
3102 -- Analyze_Operator_Call --
3103 ---------------------------
3105 procedure Analyze_Operator_Call (N : Node_Id; Op_Id : Entity_Id) is
3106 Op_Name : constant Name_Id := Chars (Op_Id);
3107 Act1 : constant Node_Id := First_Actual (N);
3108 Act2 : constant Node_Id := Next_Actual (Act1);
3111 -- Binary operator case
3113 if Present (Act2) then
3115 -- If more than two operands, then not binary operator after all
3117 if Present (Next_Actual (Act2)) then
3121 -- Otherwise action depends on operator
3131 Find_Arithmetic_Types (Act1, Act2, Op_Id, N);
3136 Find_Boolean_Types (Act1, Act2, Op_Id, N);
3142 Find_Comparison_Types (Act1, Act2, Op_Id, N);
3146 Find_Equality_Types (Act1, Act2, Op_Id, N);
3148 when Name_Op_Concat =>
3149 Find_Concatenation_Types (Act1, Act2, Op_Id, N);
3151 -- Is this when others, or should it be an abort???
3157 -- Unary operator case
3161 when Name_Op_Subtract |
3164 Find_Unary_Types (Act1, Op_Id, N);
3167 Find_Negation_Types (Act1, Op_Id, N);
3169 -- Is this when others 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 Ada 83, reject bounds of a universal range that are not literals
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;
6435 -- Check whether type has a specified indexing aspect
6439 if Is_Variable (Prefix) then
6440 Func_Name := Find_Aspect (Etype (Prefix), Aspect_Variable_Indexing);
6443 if No (Func_Name) then
6444 Func_Name := Find_Aspect (Etype (Prefix), Aspect_Constant_Indexing);
6447 -- If aspect does not exist the expression is illegal. Error is
6448 -- diagnosed in caller.
6450 if No (Func_Name) then
6452 -- The prefix itself may be an indexing of a container
6453 -- rewrite as such and re-analyze.
6455 if Has_Implicit_Dereference (Etype (Prefix)) then
6456 Build_Explicit_Dereference
6457 (Prefix, First_Discriminant (Etype (Prefix)));
6458 return Try_Container_Indexing (N, Prefix, Expr);
6465 if not Is_Overloaded (Func_Name) then
6466 Func := Entity (Func_Name);
6467 Indexing := Make_Function_Call (Loc,
6468 Name => New_Occurrence_Of (Func, Loc),
6469 Parameter_Associations =>
6470 New_List (Relocate_Node (Prefix), Relocate_Node (Expr)));
6471 Rewrite (N, Indexing);
6474 -- The return type of the indexing function is a reference type, so
6475 -- add the dereference as a possible interpretation.
6477 Disc := First_Discriminant (Etype (Func));
6478 while Present (Disc) loop
6479 if Has_Implicit_Dereference (Disc) then
6480 Add_One_Interp (N, Disc, Designated_Type (Etype (Disc)));
6484 Next_Discriminant (Disc);
6488 Indexing := Make_Function_Call (Loc,
6489 Name => Make_Identifier (Loc, Chars (Func_Name)),
6490 Parameter_Associations =>
6491 New_List (Relocate_Node (Prefix), Relocate_Node (Expr)));
6493 Rewrite (N, Indexing);
6501 Get_First_Interp (Func_Name, I, It);
6502 Set_Etype (N, Any_Type);
6503 while Present (It.Nam) loop
6504 Analyze_One_Call (N, It.Nam, False, Success);
6506 Set_Etype (Name (N), It.Typ);
6507 Set_Entity (Name (N), It.Nam);
6509 -- Add implicit dereference interpretation
6511 Disc := First_Discriminant (Etype (It.Nam));
6512 while Present (Disc) loop
6513 if Has_Implicit_Dereference (Disc) then
6515 (N, Disc, Designated_Type (Etype (Disc)));
6519 Next_Discriminant (Disc);
6524 Get_Next_Interp (I, It);
6529 if Etype (N) = Any_Type then
6530 Error_Msg_NE ("container cannot be indexed with&", N, Etype (Expr));
6531 Rewrite (N, New_Occurrence_Of (Any_Id, Loc));
6537 end Try_Container_Indexing;
6539 -----------------------
6540 -- Try_Indirect_Call --
6541 -----------------------
6543 function Try_Indirect_Call
6546 Typ : Entity_Id) return Boolean
6552 pragma Warnings (Off, Call_OK);
6555 Normalize_Actuals (N, Designated_Type (Typ), False, Call_OK);
6557 Actual := First_Actual (N);
6558 Formal := First_Formal (Designated_Type (Typ));
6559 while Present (Actual) and then Present (Formal) loop
6560 if not Has_Compatible_Type (Actual, Etype (Formal)) then
6565 Next_Formal (Formal);
6568 if No (Actual) and then No (Formal) then
6569 Add_One_Interp (N, Nam, Etype (Designated_Type (Typ)));
6571 -- Nam is a candidate interpretation for the name in the call,
6572 -- if it is not an indirect call.
6574 if not Is_Type (Nam)
6575 and then Is_Entity_Name (Name (N))
6577 Set_Entity (Name (N), Nam);
6584 end Try_Indirect_Call;
6586 ----------------------
6587 -- Try_Indexed_Call --
6588 ----------------------
6590 function Try_Indexed_Call
6594 Skip_First : Boolean) return Boolean
6596 Loc : constant Source_Ptr := Sloc (N);
6597 Actuals : constant List_Id := Parameter_Associations (N);
6602 Actual := First (Actuals);
6604 -- If the call was originally written in prefix form, skip the first
6605 -- actual, which is obviously not defaulted.
6611 Index := First_Index (Typ);
6612 while Present (Actual) and then Present (Index) loop
6614 -- If the parameter list has a named association, the expression
6615 -- is definitely a call and not an indexed component.
6617 if Nkind (Actual) = N_Parameter_Association then
6621 if Is_Entity_Name (Actual)
6622 and then Is_Type (Entity (Actual))
6623 and then No (Next (Actual))
6625 -- A single actual that is a type name indicates a slice if the
6626 -- type is discrete, and an error otherwise.
6628 if Is_Discrete_Type (Entity (Actual)) then
6632 Make_Function_Call (Loc,
6633 Name => Relocate_Node (Name (N))),
6635 New_Occurrence_Of (Entity (Actual), Sloc (Actual))));
6640 Error_Msg_N ("invalid use of type in expression", Actual);
6641 Set_Etype (N, Any_Type);
6646 elsif not Has_Compatible_Type (Actual, Etype (Index)) then
6654 if No (Actual) and then No (Index) then
6655 Add_One_Interp (N, Nam, Component_Type (Typ));
6657 -- Nam is a candidate interpretation for the name in the call,
6658 -- if it is not an indirect call.
6660 if not Is_Type (Nam)
6661 and then Is_Entity_Name (Name (N))
6663 Set_Entity (Name (N), Nam);
6670 end Try_Indexed_Call;
6672 --------------------------
6673 -- Try_Object_Operation --
6674 --------------------------
6676 function Try_Object_Operation
6677 (N : Node_Id; CW_Test_Only : Boolean := False) return Boolean
6679 K : constant Node_Kind := Nkind (Parent (N));
6680 Is_Subprg_Call : constant Boolean := Nkind_In
6681 (K, N_Procedure_Call_Statement,
6683 Loc : constant Source_Ptr := Sloc (N);
6684 Obj : constant Node_Id := Prefix (N);
6686 Subprog : constant Node_Id :=
6687 Make_Identifier (Sloc (Selector_Name (N)),
6688 Chars => Chars (Selector_Name (N)));
6689 -- Identifier on which possible interpretations will be collected
6691 Report_Error : Boolean := False;
6692 -- If no candidate interpretation matches the context, redo the
6693 -- analysis with error enabled to provide additional information.
6696 Candidate : Entity_Id := Empty;
6697 New_Call_Node : Node_Id := Empty;
6698 Node_To_Replace : Node_Id;
6699 Obj_Type : Entity_Id := Etype (Obj);
6700 Success : Boolean := False;
6702 function Valid_Candidate
6705 Subp : Entity_Id) return Entity_Id;
6706 -- If the subprogram is a valid interpretation, record it, and add
6707 -- to the list of interpretations of Subprog. Otherwise return Empty.
6709 procedure Complete_Object_Operation
6710 (Call_Node : Node_Id;
6711 Node_To_Replace : Node_Id);
6712 -- Make Subprog the name of Call_Node, replace Node_To_Replace with
6713 -- Call_Node, insert the object (or its dereference) as the first actual
6714 -- in the call, and complete the analysis of the call.
6716 procedure Report_Ambiguity (Op : Entity_Id);
6717 -- If a prefixed procedure call is ambiguous, indicate whether the
6718 -- call includes an implicit dereference or an implicit 'Access.
6720 procedure Transform_Object_Operation
6721 (Call_Node : out Node_Id;
6722 Node_To_Replace : out Node_Id);
6723 -- Transform Obj.Operation (X, Y,,) into Operation (Obj, X, Y ..)
6724 -- Call_Node is the resulting subprogram call, Node_To_Replace is
6725 -- either N or the parent of N, and Subprog is a reference to the
6726 -- subprogram we are trying to match.
6728 function Try_Class_Wide_Operation
6729 (Call_Node : Node_Id;
6730 Node_To_Replace : Node_Id) return Boolean;
6731 -- Traverse all ancestor types looking for a class-wide subprogram
6732 -- for which the current operation is a valid non-dispatching call.
6734 procedure Try_One_Prefix_Interpretation (T : Entity_Id);
6735 -- If prefix is overloaded, its interpretation may include different
6736 -- tagged types, and we must examine the primitive operations and
6737 -- the class-wide operations of each in order to find candidate
6738 -- interpretations for the call as a whole.
6740 function Try_Primitive_Operation
6741 (Call_Node : Node_Id;
6742 Node_To_Replace : Node_Id) return Boolean;
6743 -- Traverse the list of primitive subprograms looking for a dispatching
6744 -- operation for which the current node is a valid call .
6746 ---------------------
6747 -- Valid_Candidate --
6748 ---------------------
6750 function Valid_Candidate
6753 Subp : Entity_Id) return Entity_Id
6755 Arr_Type : Entity_Id;
6756 Comp_Type : Entity_Id;
6759 -- If the subprogram is a valid interpretation, record it in global
6760 -- variable Subprog, to collect all possible overloadings.
6763 if Subp /= Entity (Subprog) then
6764 Add_One_Interp (Subprog, Subp, Etype (Subp));
6768 -- If the call may be an indexed call, retrieve component type of
6769 -- resulting expression, and add possible interpretation.
6774 if Nkind (Call) = N_Function_Call
6775 and then Nkind (Parent (N)) = N_Indexed_Component
6776 and then Needs_One_Actual (Subp)
6778 if Is_Array_Type (Etype (Subp)) then
6779 Arr_Type := Etype (Subp);
6781 elsif Is_Access_Type (Etype (Subp))
6782 and then Is_Array_Type (Designated_Type (Etype (Subp)))
6784 Arr_Type := Designated_Type (Etype (Subp));
6788 if Present (Arr_Type) then
6790 -- Verify that the actuals (excluding the object) match the types
6798 Actual := Next (First_Actual (Call));
6799 Index := First_Index (Arr_Type);
6800 while Present (Actual) and then Present (Index) loop
6801 if not Has_Compatible_Type (Actual, Etype (Index)) then
6806 Next_Actual (Actual);
6812 and then Present (Arr_Type)
6814 Comp_Type := Component_Type (Arr_Type);
6818 if Present (Comp_Type)
6819 and then Etype (Subprog) /= Comp_Type
6821 Add_One_Interp (Subprog, Subp, Comp_Type);
6825 if Etype (Call) /= Any_Type then
6830 end Valid_Candidate;
6832 -------------------------------
6833 -- Complete_Object_Operation --
6834 -------------------------------
6836 procedure Complete_Object_Operation
6837 (Call_Node : Node_Id;
6838 Node_To_Replace : Node_Id)
6840 Control : constant Entity_Id := First_Formal (Entity (Subprog));
6841 Formal_Type : constant Entity_Id := Etype (Control);
6842 First_Actual : Node_Id;
6845 -- Place the name of the operation, with its interpretations,
6846 -- on the rewritten call.
6848 Set_Name (Call_Node, Subprog);
6850 First_Actual := First (Parameter_Associations (Call_Node));
6852 -- For cross-reference purposes, treat the new node as being in
6853 -- the source if the original one is. Set entity and type, even
6854 -- though they may be overwritten during resolution if overloaded.
6856 Set_Comes_From_Source (Subprog, Comes_From_Source (N));
6857 Set_Comes_From_Source (Call_Node, Comes_From_Source (N));
6859 if Nkind (N) = N_Selected_Component
6860 and then not Inside_A_Generic
6862 Set_Entity (Selector_Name (N), Entity (Subprog));
6863 Set_Etype (Selector_Name (N), Etype (Entity (Subprog)));
6866 -- If need be, rewrite first actual as an explicit dereference
6867 -- If the call is overloaded, the rewriting can only be done
6868 -- once the primitive operation is identified.
6870 if Is_Overloaded (Subprog) then
6872 -- The prefix itself may be overloaded, and its interpretations
6873 -- must be propagated to the new actual in the call.
6875 if Is_Overloaded (Obj) then
6876 Save_Interps (Obj, First_Actual);
6879 Rewrite (First_Actual, Obj);
6881 elsif not Is_Access_Type (Formal_Type)
6882 and then Is_Access_Type (Etype (Obj))
6884 Rewrite (First_Actual,
6885 Make_Explicit_Dereference (Sloc (Obj), Obj));
6886 Analyze (First_Actual);
6888 -- If we need to introduce an explicit dereference, verify that
6889 -- the resulting actual is compatible with the mode of the formal.
6891 if Ekind (First_Formal (Entity (Subprog))) /= E_In_Parameter
6892 and then Is_Access_Constant (Etype (Obj))
6895 ("expect variable in call to&", Prefix (N), Entity (Subprog));
6898 -- Conversely, if the formal is an access parameter and the object
6899 -- is not, replace the actual with a 'Access reference. Its analysis
6900 -- will check that the object is aliased.
6902 elsif Is_Access_Type (Formal_Type)
6903 and then not Is_Access_Type (Etype (Obj))
6905 -- A special case: A.all'access is illegal if A is an access to a
6906 -- constant and the context requires an access to a variable.
6908 if not Is_Access_Constant (Formal_Type) then
6909 if (Nkind (Obj) = N_Explicit_Dereference
6910 and then Is_Access_Constant (Etype (Prefix (Obj))))
6911 or else not Is_Variable (Obj)
6914 ("actual for& must be a variable", Obj, Control);
6918 Rewrite (First_Actual,
6919 Make_Attribute_Reference (Loc,
6920 Attribute_Name => Name_Access,
6921 Prefix => Relocate_Node (Obj)));
6923 if not Is_Aliased_View (Obj) then
6925 ("object in prefixed call to& must be aliased"
6926 & " (RM-2005 4.3.1 (13))",
6927 Prefix (First_Actual), Subprog);
6930 Analyze (First_Actual);
6933 if Is_Overloaded (Obj) then
6934 Save_Interps (Obj, First_Actual);
6937 Rewrite (First_Actual, Obj);
6940 Rewrite (Node_To_Replace, Call_Node);
6942 -- Propagate the interpretations collected in subprog to the new
6943 -- function call node, to be resolved from context.
6945 if Is_Overloaded (Subprog) then
6946 Save_Interps (Subprog, Node_To_Replace);
6949 Analyze (Node_To_Replace);
6951 -- If the operation has been rewritten into a call, which may get
6952 -- subsequently an explicit dereference, preserve the type on the
6953 -- original node (selected component or indexed component) for
6954 -- subsequent legality tests, e.g. Is_Variable. which examines
6955 -- the original node.
6957 if Nkind (Node_To_Replace) = N_Function_Call then
6959 (Original_Node (Node_To_Replace), Etype (Node_To_Replace));
6962 end Complete_Object_Operation;
6964 ----------------------
6965 -- Report_Ambiguity --
6966 ----------------------
6968 procedure Report_Ambiguity (Op : Entity_Id) is
6969 Access_Actual : constant Boolean :=
6970 Is_Access_Type (Etype (Prefix (N)));
6971 Access_Formal : Boolean := False;
6974 Error_Msg_Sloc := Sloc (Op);
6976 if Present (First_Formal (Op)) then
6977 Access_Formal := Is_Access_Type (Etype (First_Formal (Op)));
6980 if Access_Formal and then not Access_Actual then
6981 if Nkind (Parent (Op)) = N_Full_Type_Declaration then
6983 ("\possible interpretation"
6984 & " (inherited, with implicit 'Access) #", N);
6987 ("\possible interpretation (with implicit 'Access) #", N);
6990 elsif not Access_Formal and then Access_Actual then
6991 if Nkind (Parent (Op)) = N_Full_Type_Declaration then
6993 ("\possible interpretation"
6994 & " ( inherited, with implicit dereference) #", N);
6997 ("\possible interpretation (with implicit dereference) #", N);
7001 if Nkind (Parent (Op)) = N_Full_Type_Declaration then
7002 Error_Msg_N ("\possible interpretation (inherited)#", N);
7004 Error_Msg_N -- CODEFIX
7005 ("\possible interpretation#", N);
7008 end Report_Ambiguity;
7010 --------------------------------
7011 -- Transform_Object_Operation --
7012 --------------------------------
7014 procedure Transform_Object_Operation
7015 (Call_Node : out Node_Id;
7016 Node_To_Replace : out Node_Id)
7018 Dummy : constant Node_Id := New_Copy (Obj);
7019 -- Placeholder used as a first parameter in the call, replaced
7020 -- eventually by the proper object.
7022 Parent_Node : constant Node_Id := Parent (N);
7028 -- Common case covering 1) Call to a procedure and 2) Call to a
7029 -- function that has some additional actuals.
7031 if Nkind_In (Parent_Node, N_Function_Call,
7032 N_Procedure_Call_Statement)
7034 -- N is a selected component node containing the name of the
7035 -- subprogram. If N is not the name of the parent node we must
7036 -- not replace the parent node by the new construct. This case
7037 -- occurs when N is a parameterless call to a subprogram that
7038 -- is an actual parameter of a call to another subprogram. For
7040 -- Some_Subprogram (..., Obj.Operation, ...)
7042 and then Name (Parent_Node) = N
7044 Node_To_Replace := Parent_Node;
7046 Actuals := Parameter_Associations (Parent_Node);
7048 if Present (Actuals) then
7049 Prepend (Dummy, Actuals);
7051 Actuals := New_List (Dummy);
7054 if Nkind (Parent_Node) = N_Procedure_Call_Statement then
7056 Make_Procedure_Call_Statement (Loc,
7057 Name => New_Copy (Subprog),
7058 Parameter_Associations => Actuals);
7062 Make_Function_Call (Loc,
7063 Name => New_Copy (Subprog),
7064 Parameter_Associations => Actuals);
7068 -- Before analysis, a function call appears as an indexed component
7069 -- if there are no named associations.
7071 elsif Nkind (Parent_Node) = N_Indexed_Component
7072 and then N = Prefix (Parent_Node)
7074 Node_To_Replace := Parent_Node;
7075 Actuals := Expressions (Parent_Node);
7077 Actual := First (Actuals);
7078 while Present (Actual) loop
7083 Prepend (Dummy, Actuals);
7086 Make_Function_Call (Loc,
7087 Name => New_Copy (Subprog),
7088 Parameter_Associations => Actuals);
7090 -- Parameterless call: Obj.F is rewritten as F (Obj)
7093 Node_To_Replace := N;
7096 Make_Function_Call (Loc,
7097 Name => New_Copy (Subprog),
7098 Parameter_Associations => New_List (Dummy));
7100 end Transform_Object_Operation;
7102 ------------------------------
7103 -- Try_Class_Wide_Operation --
7104 ------------------------------
7106 function Try_Class_Wide_Operation
7107 (Call_Node : Node_Id;
7108 Node_To_Replace : Node_Id) return Boolean
7110 Anc_Type : Entity_Id;
7111 Matching_Op : Entity_Id := Empty;
7114 procedure Traverse_Homonyms
7115 (Anc_Type : Entity_Id;
7116 Error : out Boolean);
7117 -- Traverse the homonym chain of the subprogram searching for those
7118 -- homonyms whose first formal has the Anc_Type's class-wide type,
7119 -- or an anonymous access type designating the class-wide type. If
7120 -- an ambiguity is detected, then Error is set to True.
7122 procedure Traverse_Interfaces
7123 (Anc_Type : Entity_Id;
7124 Error : out Boolean);
7125 -- Traverse the list of interfaces, if any, associated with Anc_Type
7126 -- and search for acceptable class-wide homonyms associated with each
7127 -- interface. If an ambiguity is detected, then Error is set to True.
7129 -----------------------
7130 -- Traverse_Homonyms --
7131 -----------------------
7133 procedure Traverse_Homonyms
7134 (Anc_Type : Entity_Id;
7135 Error : out Boolean)
7137 Cls_Type : Entity_Id;
7145 Cls_Type := Class_Wide_Type (Anc_Type);
7147 Hom := Current_Entity (Subprog);
7149 -- Find a non-hidden operation whose first parameter is of the
7150 -- class-wide type, a subtype thereof, or an anonymous access
7153 while Present (Hom) loop
7154 if Ekind_In (Hom, E_Procedure, E_Function)
7155 and then not Is_Hidden (Hom)
7156 and then Scope (Hom) = Scope (Anc_Type)
7157 and then Present (First_Formal (Hom))
7159 (Base_Type (Etype (First_Formal (Hom))) = Cls_Type
7161 (Is_Access_Type (Etype (First_Formal (Hom)))
7163 Ekind (Etype (First_Formal (Hom))) =
7164 E_Anonymous_Access_Type
7167 (Designated_Type (Etype (First_Formal (Hom)))) =
7170 -- If the context is a procedure call, ignore functions
7171 -- in the name of the call.
7173 if Ekind (Hom) = E_Function
7174 and then Nkind (Parent (N)) = N_Procedure_Call_Statement
7175 and then N = Name (Parent (N))
7179 -- If the context is a function call, ignore procedures
7180 -- in the name of the call.
7182 elsif Ekind (Hom) = E_Procedure
7183 and then Nkind (Parent (N)) /= N_Procedure_Call_Statement
7188 Set_Etype (Call_Node, Any_Type);
7189 Set_Is_Overloaded (Call_Node, False);
7192 if No (Matching_Op) then
7193 Hom_Ref := New_Reference_To (Hom, Sloc (Subprog));
7194 Set_Etype (Call_Node, Any_Type);
7195 Set_Parent (Call_Node, Parent (Node_To_Replace));
7197 Set_Name (Call_Node, Hom_Ref);
7202 Report => Report_Error,
7204 Skip_First => True);
7207 Valid_Candidate (Success, Call_Node, Hom);
7213 Report => Report_Error,
7215 Skip_First => True);
7217 if Present (Valid_Candidate (Success, Call_Node, Hom))
7218 and then Nkind (Call_Node) /= N_Function_Call
7220 Error_Msg_NE ("ambiguous call to&", N, Hom);
7221 Report_Ambiguity (Matching_Op);
7222 Report_Ambiguity (Hom);
7230 Hom := Homonym (Hom);
7232 end Traverse_Homonyms;
7234 -------------------------
7235 -- Traverse_Interfaces --
7236 -------------------------
7238 procedure Traverse_Interfaces
7239 (Anc_Type : Entity_Id;
7240 Error : out Boolean)
7242 Intface_List : constant List_Id :=
7243 Abstract_Interface_List (Anc_Type);
7249 if Is_Non_Empty_List (Intface_List) then
7250 Intface := First (Intface_List);
7251 while Present (Intface) loop
7253 -- Look for acceptable class-wide homonyms associated with
7256 Traverse_Homonyms (Etype (Intface), Error);
7262 -- Continue the search by looking at each of the interface's
7263 -- associated interface ancestors.
7265 Traverse_Interfaces (Etype (Intface), Error);
7274 end Traverse_Interfaces;
7276 -- Start of processing for Try_Class_Wide_Operation
7279 -- If we are searching only for conflicting class-wide subprograms
7280 -- then initialize directly Matching_Op with the target entity.
7282 if CW_Test_Only then
7283 Matching_Op := Entity (Selector_Name (N));
7286 -- Loop through ancestor types (including interfaces), traversing
7287 -- the homonym chain of the subprogram, trying out those homonyms
7288 -- whose first formal has the class-wide type of the ancestor, or
7289 -- an anonymous access type designating the class-wide type.
7291 Anc_Type := Obj_Type;
7293 -- Look for a match among homonyms associated with the ancestor
7295 Traverse_Homonyms (Anc_Type, Error);
7301 -- Continue the search for matches among homonyms associated with
7302 -- any interfaces implemented by the ancestor.
7304 Traverse_Interfaces (Anc_Type, Error);
7310 exit when Etype (Anc_Type) = Anc_Type;
7311 Anc_Type := Etype (Anc_Type);
7314 if Present (Matching_Op) then
7315 Set_Etype (Call_Node, Etype (Matching_Op));
7318 return Present (Matching_Op);
7319 end Try_Class_Wide_Operation;
7321 -----------------------------------
7322 -- Try_One_Prefix_Interpretation --
7323 -----------------------------------
7325 procedure Try_One_Prefix_Interpretation (T : Entity_Id) is
7329 if Is_Access_Type (Obj_Type) then
7330 Obj_Type := Designated_Type (Obj_Type);
7333 if Ekind (Obj_Type) = E_Private_Subtype then
7334 Obj_Type := Base_Type (Obj_Type);
7337 if Is_Class_Wide_Type (Obj_Type) then
7338 Obj_Type := Etype (Class_Wide_Type (Obj_Type));
7341 -- The type may have be obtained through a limited_with clause,
7342 -- in which case the primitive operations are available on its
7343 -- non-limited view. If still incomplete, retrieve full view.
7345 if Ekind (Obj_Type) = E_Incomplete_Type
7346 and then From_With_Type (Obj_Type)
7348 Obj_Type := Get_Full_View (Non_Limited_View (Obj_Type));
7351 -- If the object is not tagged, or the type is still an incomplete
7352 -- type, this is not a prefixed call.
7354 if not Is_Tagged_Type (Obj_Type)
7355 or else Is_Incomplete_Type (Obj_Type)
7361 Dup_Call_Node : constant Node_Id := New_Copy (New_Call_Node);
7362 CW_Result : Boolean;
7363 Prim_Result : Boolean;
7364 pragma Unreferenced (CW_Result);
7367 if not CW_Test_Only then
7369 Try_Primitive_Operation
7370 (Call_Node => New_Call_Node,
7371 Node_To_Replace => Node_To_Replace);
7374 -- Check if there is a class-wide subprogram covering the
7375 -- primitive. This check must be done even if a candidate
7376 -- was found in order to report ambiguous calls.
7378 if not (Prim_Result) then
7380 Try_Class_Wide_Operation
7381 (Call_Node => New_Call_Node,
7382 Node_To_Replace => Node_To_Replace);
7384 -- If we found a primitive we search for class-wide subprograms
7385 -- using a duplicate of the call node (done to avoid missing its
7386 -- decoration if there is no ambiguity).
7390 Try_Class_Wide_Operation
7391 (Call_Node => Dup_Call_Node,
7392 Node_To_Replace => Node_To_Replace);
7395 end Try_One_Prefix_Interpretation;
7397 -----------------------------
7398 -- Try_Primitive_Operation --
7399 -----------------------------
7401 function Try_Primitive_Operation
7402 (Call_Node : Node_Id;
7403 Node_To_Replace : Node_Id) return Boolean
7406 Prim_Op : Entity_Id;
7407 Matching_Op : Entity_Id := Empty;
7408 Prim_Op_Ref : Node_Id := Empty;
7410 Corr_Type : Entity_Id := Empty;
7411 -- If the prefix is a synchronized type, the controlling type of
7412 -- the primitive operation is the corresponding record type, else
7413 -- this is the object type itself.
7415 Success : Boolean := False;
7417 function Collect_Generic_Type_Ops (T : Entity_Id) return Elist_Id;
7418 -- For tagged types the candidate interpretations are found in
7419 -- the list of primitive operations of the type and its ancestors.
7420 -- For formal tagged types we have to find the operations declared
7421 -- in the same scope as the type (including in the generic formal
7422 -- part) because the type itself carries no primitive operations,
7423 -- except for formal derived types that inherit the operations of
7424 -- the parent and progenitors.
7425 -- If the context is a generic subprogram body, the generic formals
7426 -- are visible by name, but are not in the entity list of the
7427 -- subprogram because that list starts with the subprogram formals.
7428 -- We retrieve the candidate operations from the generic declaration.
7430 function Is_Private_Overriding (Op : Entity_Id) return Boolean;
7431 -- An operation that overrides an inherited operation in the private
7432 -- part of its package may be hidden, but if the inherited operation
7433 -- is visible a direct call to it will dispatch to the private one,
7434 -- which is therefore a valid candidate.
7436 function Valid_First_Argument_Of (Op : Entity_Id) return Boolean;
7437 -- Verify that the prefix, dereferenced if need be, is a valid
7438 -- controlling argument in a call to Op. The remaining actuals
7439 -- are checked in the subsequent call to Analyze_One_Call.
7441 ------------------------------
7442 -- Collect_Generic_Type_Ops --
7443 ------------------------------
7445 function Collect_Generic_Type_Ops (T : Entity_Id) return Elist_Id is
7446 Bas : constant Entity_Id := Base_Type (T);
7447 Candidates : constant Elist_Id := New_Elmt_List;
7451 procedure Check_Candidate;
7452 -- The operation is a candidate if its first parameter is a
7453 -- controlling operand of the desired type.
7455 -----------------------
7456 -- Check_Candidate; --
7457 -----------------------
7459 procedure Check_Candidate is
7461 Formal := First_Formal (Subp);
7464 and then Is_Controlling_Formal (Formal)
7466 (Base_Type (Etype (Formal)) = Bas
7468 (Is_Access_Type (Etype (Formal))
7469 and then Designated_Type (Etype (Formal)) = Bas))
7471 Append_Elmt (Subp, Candidates);
7473 end Check_Candidate;
7475 -- Start of processing for Collect_Generic_Type_Ops
7478 if Is_Derived_Type (T) then
7479 return Primitive_Operations (T);
7481 elsif Ekind_In (Scope (T), E_Procedure, E_Function) then
7483 -- Scan the list of generic formals to find subprograms
7484 -- that may have a first controlling formal of the type.
7486 if Nkind (Unit_Declaration_Node (Scope (T)))
7487 = N_Generic_Subprogram_Declaration
7494 First (Generic_Formal_Declarations
7495 (Unit_Declaration_Node (Scope (T))));
7496 while Present (Decl) loop
7497 if Nkind (Decl) in N_Formal_Subprogram_Declaration then
7498 Subp := Defining_Entity (Decl);
7509 -- Scan the list of entities declared in the same scope as
7510 -- the type. In general this will be an open scope, given that
7511 -- the call we are analyzing can only appear within a generic
7512 -- declaration or body (either the one that declares T, or a
7515 -- For a subtype representing a generic actual type, go to the
7518 if Is_Generic_Actual_Type (T) then
7519 Subp := First_Entity (Scope (Base_Type (T)));
7521 Subp := First_Entity (Scope (T));
7524 while Present (Subp) loop
7525 if Is_Overloadable (Subp) then
7534 end Collect_Generic_Type_Ops;
7536 ---------------------------
7537 -- Is_Private_Overriding --
7538 ---------------------------
7540 function Is_Private_Overriding (Op : Entity_Id) return Boolean is
7541 Visible_Op : constant Entity_Id := Homonym (Op);
7544 return Present (Visible_Op)
7545 and then Scope (Op) = Scope (Visible_Op)
7546 and then not Comes_From_Source (Visible_Op)
7547 and then Alias (Visible_Op) = Op
7548 and then not Is_Hidden (Visible_Op);
7549 end Is_Private_Overriding;
7551 -----------------------------
7552 -- Valid_First_Argument_Of --
7553 -----------------------------
7555 function Valid_First_Argument_Of (Op : Entity_Id) return Boolean is
7556 Typ : Entity_Id := Etype (First_Formal (Op));
7559 if Is_Concurrent_Type (Typ)
7560 and then Present (Corresponding_Record_Type (Typ))
7562 Typ := Corresponding_Record_Type (Typ);
7565 -- Simple case. Object may be a subtype of the tagged type or
7566 -- may be the corresponding record of a synchronized type.
7568 return Obj_Type = Typ
7569 or else Base_Type (Obj_Type) = Typ
7570 or else Corr_Type = Typ
7572 -- Prefix can be dereferenced
7575 (Is_Access_Type (Corr_Type)
7576 and then Designated_Type (Corr_Type) = Typ)
7578 -- Formal is an access parameter, for which the object
7579 -- can provide an access.
7582 (Ekind (Typ) = E_Anonymous_Access_Type
7584 Base_Type (Designated_Type (Typ)) = Base_Type (Corr_Type));
7585 end Valid_First_Argument_Of;
7587 -- Start of processing for Try_Primitive_Operation
7590 -- Look for subprograms in the list of primitive operations. The name
7591 -- must be identical, and the kind of call indicates the expected
7592 -- kind of operation (function or procedure). If the type is a
7593 -- (tagged) synchronized type, the primitive ops are attached to the
7594 -- corresponding record (base) type.
7596 if Is_Concurrent_Type (Obj_Type) then
7597 if Present (Corresponding_Record_Type (Obj_Type)) then
7598 Corr_Type := Base_Type (Corresponding_Record_Type (Obj_Type));
7599 Elmt := First_Elmt (Primitive_Operations (Corr_Type));
7601 Corr_Type := Obj_Type;
7602 Elmt := First_Elmt (Collect_Generic_Type_Ops (Obj_Type));
7605 elsif not Is_Generic_Type (Obj_Type) then
7606 Corr_Type := Obj_Type;
7607 Elmt := First_Elmt (Primitive_Operations (Obj_Type));
7610 Corr_Type := Obj_Type;
7611 Elmt := First_Elmt (Collect_Generic_Type_Ops (Obj_Type));
7614 while Present (Elmt) loop
7615 Prim_Op := Node (Elmt);
7617 if Chars (Prim_Op) = Chars (Subprog)
7618 and then Present (First_Formal (Prim_Op))
7619 and then Valid_First_Argument_Of (Prim_Op)
7621 (Nkind (Call_Node) = N_Function_Call)
7622 = (Ekind (Prim_Op) = E_Function)
7624 -- Ada 2005 (AI-251): If this primitive operation corresponds
7625 -- with an immediate ancestor interface there is no need to add
7626 -- it to the list of interpretations; the corresponding aliased
7627 -- primitive is also in this list of primitive operations and
7628 -- will be used instead.
7630 if (Present (Interface_Alias (Prim_Op))
7631 and then Is_Ancestor (Find_Dispatching_Type
7632 (Alias (Prim_Op)), Corr_Type))
7634 -- Do not consider hidden primitives unless the type is in an
7635 -- open scope or we are within an instance, where visibility
7636 -- is known to be correct, or else if this is an overriding
7637 -- operation in the private part for an inherited operation.
7639 or else (Is_Hidden (Prim_Op)
7640 and then not Is_Immediately_Visible (Obj_Type)
7641 and then not In_Instance
7642 and then not Is_Private_Overriding (Prim_Op))
7647 Set_Etype (Call_Node, Any_Type);
7648 Set_Is_Overloaded (Call_Node, False);
7650 if No (Matching_Op) then
7651 Prim_Op_Ref := New_Reference_To (Prim_Op, Sloc (Subprog));
7652 Candidate := Prim_Op;
7654 Set_Parent (Call_Node, Parent (Node_To_Replace));
7656 Set_Name (Call_Node, Prim_Op_Ref);
7662 Report => Report_Error,
7664 Skip_First => True);
7666 Matching_Op := Valid_Candidate (Success, Call_Node, Prim_Op);
7668 -- More than one interpretation, collect for subsequent
7669 -- disambiguation. If this is a procedure call and there
7670 -- is another match, report ambiguity now.
7676 Report => Report_Error,
7678 Skip_First => True);
7680 if Present (Valid_Candidate (Success, Call_Node, Prim_Op))
7681 and then Nkind (Call_Node) /= N_Function_Call
7683 Error_Msg_NE ("ambiguous call to&", N, Prim_Op);
7684 Report_Ambiguity (Matching_Op);
7685 Report_Ambiguity (Prim_Op);
7695 if Present (Matching_Op) then
7696 Set_Etype (Call_Node, Etype (Matching_Op));
7699 return Present (Matching_Op);
7700 end Try_Primitive_Operation;
7702 -- Start of processing for Try_Object_Operation
7705 Analyze_Expression (Obj);
7707 -- Analyze the actuals if node is known to be a subprogram call
7709 if Is_Subprg_Call and then N = Name (Parent (N)) then
7710 Actual := First (Parameter_Associations (Parent (N)));
7711 while Present (Actual) loop
7712 Analyze_Expression (Actual);
7717 -- Build a subprogram call node, using a copy of Obj as its first
7718 -- actual. This is a placeholder, to be replaced by an explicit
7719 -- dereference when needed.
7721 Transform_Object_Operation
7722 (Call_Node => New_Call_Node,
7723 Node_To_Replace => Node_To_Replace);
7725 Set_Etype (New_Call_Node, Any_Type);
7726 Set_Etype (Subprog, Any_Type);
7727 Set_Parent (New_Call_Node, Parent (Node_To_Replace));
7729 if not Is_Overloaded (Obj) then
7730 Try_One_Prefix_Interpretation (Obj_Type);
7737 Get_First_Interp (Obj, I, It);
7738 while Present (It.Nam) loop
7739 Try_One_Prefix_Interpretation (It.Typ);
7740 Get_Next_Interp (I, It);
7745 if Etype (New_Call_Node) /= Any_Type then
7747 -- No need to complete the tree transformations if we are only
7748 -- searching for conflicting class-wide subprograms
7750 if CW_Test_Only then
7753 Complete_Object_Operation
7754 (Call_Node => New_Call_Node,
7755 Node_To_Replace => Node_To_Replace);
7759 elsif Present (Candidate) then
7761 -- The argument list is not type correct. Re-analyze with error
7762 -- reporting enabled, and use one of the possible candidates.
7763 -- In All_Errors_Mode, re-analyze all failed interpretations.
7765 if All_Errors_Mode then
7766 Report_Error := True;
7767 if Try_Primitive_Operation
7768 (Call_Node => New_Call_Node,
7769 Node_To_Replace => Node_To_Replace)
7772 Try_Class_Wide_Operation
7773 (Call_Node => New_Call_Node,
7774 Node_To_Replace => Node_To_Replace)
7781 (N => New_Call_Node,
7785 Skip_First => True);
7788 -- No need for further errors
7793 -- There was no candidate operation, so report it as an error
7794 -- in the caller: Analyze_Selected_Component.
7798 end Try_Object_Operation;
7804 procedure wpo (T : Entity_Id) is
7809 if not Is_Tagged_Type (T) then
7813 E := First_Elmt (Primitive_Operations (Base_Type (T)));
7814 while Present (E) loop
7816 Write_Int (Int (Op));
7817 Write_Str (" === ");
7818 Write_Name (Chars (Op));
7820 Write_Name (Chars (Scope (Op)));