1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2011, Free Software Foundation, Inc. --
11 -- GNAT is free software; you can redistribute it and/or modify it under --
12 -- terms of the GNU General Public License as published by the Free Soft- --
13 -- ware Foundation; either version 3, or (at your option) any later ver- --
14 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
15 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
16 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
17 -- for more details. You should have received a copy of the GNU General --
18 -- Public License distributed with GNAT; see file COPYING3. If not, go to --
19 -- http://www.gnu.org/licenses for a complete copy of the license. --
21 -- GNAT was originally developed by the GNAT team at New York University. --
22 -- Extensive contributions were provided by Ada Core Technologies Inc. --
24 ------------------------------------------------------------------------------
26 with Atree; use Atree;
27 with Debug; use Debug;
28 with Einfo; use Einfo;
29 with Elists; use Elists;
30 with Errout; use Errout;
31 with Exp_Util; use Exp_Util;
32 with Fname; use Fname;
33 with Itypes; use Itypes;
35 with Lib.Xref; use Lib.Xref;
36 with Namet; use Namet;
37 with Namet.Sp; use Namet.Sp;
38 with Nlists; use Nlists;
39 with Nmake; use Nmake;
41 with Output; use Output;
42 with Restrict; use Restrict;
43 with Rident; use Rident;
45 with Sem_Aux; use Sem_Aux;
46 with Sem_Case; use Sem_Case;
47 with Sem_Cat; use Sem_Cat;
48 with Sem_Ch3; use Sem_Ch3;
49 with Sem_Ch5; use Sem_Ch5;
50 with Sem_Ch6; use Sem_Ch6;
51 with Sem_Ch8; use Sem_Ch8;
52 with Sem_Disp; use Sem_Disp;
53 with Sem_Dist; use Sem_Dist;
54 with Sem_Eval; use Sem_Eval;
55 with Sem_Res; use Sem_Res;
56 with Sem_Type; use Sem_Type;
57 with Sem_Util; use Sem_Util;
58 with Sem_Warn; use Sem_Warn;
59 with Stand; use Stand;
60 with Sinfo; use Sinfo;
61 with Snames; use Snames;
62 with Tbuild; use Tbuild;
64 package body Sem_Ch4 is
66 -----------------------
67 -- Local Subprograms --
68 -----------------------
70 procedure Analyze_Concatenation_Rest (N : Node_Id);
71 -- Does the "rest" of the work of Analyze_Concatenation, after the left
72 -- operand has been analyzed. See Analyze_Concatenation for details.
74 procedure Analyze_Expression (N : Node_Id);
75 -- For expressions that are not names, this is just a call to analyze.
76 -- If the expression is a name, it may be a call to a parameterless
77 -- function, and if so must be converted into an explicit call node
78 -- and analyzed as such. This deproceduring must be done during the first
79 -- pass of overload resolution, because otherwise a procedure call with
80 -- overloaded actuals may fail to resolve.
82 procedure Analyze_Operator_Call (N : Node_Id; Op_Id : Entity_Id);
83 -- Analyze a call of the form "+"(x, y), etc. The prefix of the call
84 -- is an operator name or an expanded name whose selector is an operator
85 -- name, and one possible interpretation is as a predefined operator.
87 procedure Analyze_Overloaded_Selected_Component (N : Node_Id);
88 -- If the prefix of a selected_component is overloaded, the proper
89 -- interpretation that yields a record type with the proper selector
90 -- name must be selected.
92 procedure Analyze_User_Defined_Binary_Op (N : Node_Id; Op_Id : Entity_Id);
93 -- Procedure to analyze a user defined binary operator, which is resolved
94 -- like a function, but instead of a list of actuals it is presented
95 -- with the left and right operands of an operator node.
97 procedure Analyze_User_Defined_Unary_Op (N : Node_Id; Op_Id : Entity_Id);
98 -- Procedure to analyze a user defined unary operator, which is resolved
99 -- like a function, but instead of a list of actuals, it is presented with
100 -- the operand of the operator node.
102 procedure Ambiguous_Operands (N : Node_Id);
103 -- For equality, membership, and comparison operators with overloaded
104 -- arguments, list possible interpretations.
106 procedure Analyze_One_Call
110 Success : out Boolean;
111 Skip_First : Boolean := False);
112 -- Check one interpretation of an overloaded subprogram name for
113 -- compatibility with the types of the actuals in a call. If there is a
114 -- single interpretation which does not match, post error if Report is
117 -- Nam is the entity that provides the formals against which the actuals
118 -- are checked. Nam is either the name of a subprogram, or the internal
119 -- subprogram type constructed for an access_to_subprogram. If the actuals
120 -- are compatible with Nam, then Nam is added to the list of candidate
121 -- interpretations for N, and Success is set to True.
123 -- The flag Skip_First is used when analyzing a call that was rewritten
124 -- from object notation. In this case the first actual may have to receive
125 -- an explicit dereference, depending on the first formal of the operation
126 -- being called. The caller will have verified that the object is legal
127 -- for the call. If the remaining parameters match, the first parameter
128 -- will rewritten as a dereference if needed, prior to completing analysis.
130 procedure Check_Misspelled_Selector
133 -- Give possible misspelling diagnostic if Sel is likely to be a mis-
134 -- spelling of one of the selectors of the Prefix. This is called by
135 -- Analyze_Selected_Component after producing an invalid selector error
138 function Defined_In_Scope (T : Entity_Id; S : Entity_Id) return Boolean;
139 -- Verify that type T is declared in scope S. Used to find interpretations
140 -- for operators given by expanded names. This is abstracted as a separate
141 -- function to handle extensions to System, where S is System, but T is
142 -- declared in the extension.
144 procedure Find_Arithmetic_Types
148 -- L and R are the operands of an arithmetic operator. Find
149 -- consistent pairs of interpretations for L and R that have a
150 -- numeric type consistent with the semantics of the operator.
152 procedure Find_Comparison_Types
156 -- L and R are operands of a comparison operator. Find consistent
157 -- pairs of interpretations for L and R.
159 procedure Find_Concatenation_Types
163 -- For the four varieties of concatenation
165 procedure Find_Equality_Types
169 -- Ditto for equality operators
171 procedure Find_Boolean_Types
175 -- Ditto for binary logical operations
177 procedure Find_Negation_Types
181 -- Find consistent interpretation for operand of negation operator
183 procedure Find_Non_Universal_Interpretations
188 -- For equality and comparison operators, the result is always boolean,
189 -- and the legality of the operation is determined from the visibility
190 -- of the operand types. If one of the operands has a universal interpre-
191 -- tation, the legality check uses some compatible non-universal
192 -- interpretation of the other operand. N can be an operator node, or
193 -- a function call whose name is an operator designator.
195 function Find_Primitive_Operation (N : Node_Id) return Boolean;
196 -- Find candidate interpretations for the name Obj.Proc when it appears
197 -- in a subprogram renaming declaration.
199 procedure Find_Unary_Types
203 -- Unary arithmetic types: plus, minus, abs
205 procedure Check_Arithmetic_Pair
209 -- Subsidiary procedure to Find_Arithmetic_Types. T1 and T2 are valid
210 -- types for left and right operand. Determine whether they constitute
211 -- a valid pair for the given operator, and record the corresponding
212 -- interpretation of the operator node. The node N may be an operator
213 -- node (the usual case) or a function call whose prefix is an operator
214 -- designator. In both cases Op_Id is the operator name itself.
216 procedure Diagnose_Call (N : Node_Id; Nam : Node_Id);
217 -- Give detailed information on overloaded call where none of the
218 -- interpretations match. N is the call node, Nam the designator for
219 -- the overloaded entity being called.
221 function Junk_Operand (N : Node_Id) return Boolean;
222 -- Test for an operand that is an inappropriate entity (e.g. a package
223 -- name or a label). If so, issue an error message and return True. If
224 -- the operand is not an inappropriate entity kind, return False.
226 procedure Operator_Check (N : Node_Id);
227 -- Verify that an operator has received some valid interpretation. If none
228 -- was found, determine whether a use clause would make the operation
229 -- legal. The variable Candidate_Type (defined in Sem_Type) is set for
230 -- every type compatible with the operator, even if the operator for the
231 -- type is not directly visible. The routine uses this type to emit a more
232 -- informative message.
234 function Process_Implicit_Dereference_Prefix
236 P : Node_Id) return Entity_Id;
237 -- Called when P is the prefix of an implicit dereference, denoting an
238 -- object E. The function returns the designated type of the prefix, taking
239 -- into account that the designated type of an anonymous access type may be
240 -- a limited view, when the non-limited view is visible.
241 -- If in semantics only mode (-gnatc or generic), the function also records
242 -- that the prefix is a reference to E, if any. Normally, such a reference
243 -- is generated only when the implicit dereference is expanded into an
244 -- explicit one, but for consistency we must generate the reference when
245 -- expansion is disabled as well.
247 procedure Remove_Abstract_Operations (N : Node_Id);
248 -- Ada 2005: implementation of AI-310. An abstract non-dispatching
249 -- operation is not a candidate interpretation.
251 function Try_Indexed_Call
255 Skip_First : Boolean) return Boolean;
256 -- If a function has defaults for all its actuals, a call to it may in fact
257 -- be an indexing on the result of the call. Try_Indexed_Call attempts the
258 -- interpretation as an indexing, prior to analysis as a call. If both are
259 -- possible, the node is overloaded with both interpretations (same symbol
260 -- but two different types). If the call is written in prefix form, the
261 -- prefix becomes the first parameter in the call, and only the remaining
262 -- actuals must be checked for the presence of defaults.
264 function Try_Indirect_Call
267 Typ : Entity_Id) return Boolean;
268 -- Similarly, a function F that needs no actuals can return an access to a
269 -- subprogram, and the call F (X) interpreted as F.all (X). In this case
270 -- the call may be overloaded with both interpretations.
272 function Try_Object_Operation (N : Node_Id) return Boolean;
273 -- Ada 2005 (AI-252): Support the object.operation notation. If node N
274 -- is a call in this notation, it is transformed into a normal subprogram
275 -- call where the prefix is a parameter, and True is returned. If node
276 -- N is not of this form, it is unchanged, and False is returned.
278 procedure wpo (T : Entity_Id);
279 pragma Warnings (Off, wpo);
280 -- Used for debugging: obtain list of primitive operations even if
281 -- type is not frozen and dispatch table is not built yet.
283 ------------------------
284 -- Ambiguous_Operands --
285 ------------------------
287 procedure Ambiguous_Operands (N : Node_Id) is
288 procedure List_Operand_Interps (Opnd : Node_Id);
290 --------------------------
291 -- List_Operand_Interps --
292 --------------------------
294 procedure List_Operand_Interps (Opnd : Node_Id) is
299 if Is_Overloaded (Opnd) then
300 if Nkind (Opnd) in N_Op then
302 elsif Nkind (Opnd) = N_Function_Call then
312 if Opnd = Left_Opnd (N) then
313 Error_Msg_N ("\left operand has the following interpretations", N);
316 ("\right operand has the following interpretations", N);
320 List_Interps (Nam, Err);
321 end List_Operand_Interps;
323 -- Start of processing for Ambiguous_Operands
326 if Nkind (N) in N_Membership_Test then
327 Error_Msg_N ("ambiguous operands for membership", N);
329 elsif Nkind_In (N, N_Op_Eq, N_Op_Ne) then
330 Error_Msg_N ("ambiguous operands for equality", N);
333 Error_Msg_N ("ambiguous operands for comparison", N);
336 if All_Errors_Mode then
337 List_Operand_Interps (Left_Opnd (N));
338 List_Operand_Interps (Right_Opnd (N));
340 Error_Msg_N ("\use -gnatf switch for details", N);
342 end Ambiguous_Operands;
344 -----------------------
345 -- Analyze_Aggregate --
346 -----------------------
348 -- Most of the analysis of Aggregates requires that the type be known,
349 -- and is therefore put off until resolution.
351 procedure Analyze_Aggregate (N : Node_Id) is
353 if No (Etype (N)) then
354 Set_Etype (N, Any_Composite);
356 end Analyze_Aggregate;
358 -----------------------
359 -- Analyze_Allocator --
360 -----------------------
362 procedure Analyze_Allocator (N : Node_Id) is
363 Loc : constant Source_Ptr := Sloc (N);
364 Sav_Errs : constant Nat := Serious_Errors_Detected;
365 E : Node_Id := Expression (N);
366 Acc_Type : Entity_Id;
372 Check_SPARK_Restriction ("allocator is not allowed", N);
374 -- Deal with allocator restrictions
376 -- In accordance with H.4(7), the No_Allocators restriction only applies
377 -- to user-written allocators. The same consideration applies to the
378 -- No_Allocators_Before_Elaboration restriction.
380 if Comes_From_Source (N) then
381 Check_Restriction (No_Allocators, N);
383 -- Processing for No_Allocators_After_Elaboration, loop to look at
384 -- enclosing context, checking task case and main subprogram case.
388 while Present (P) loop
390 -- In both cases we need a handled sequence of statements, where
391 -- the occurrence of the allocator is within the statements.
393 if Nkind (P) = N_Handled_Sequence_Of_Statements
394 and then Is_List_Member (C)
395 and then List_Containing (C) = Statements (P)
397 -- Check for allocator within task body, this is a definite
398 -- violation of No_Allocators_After_Elaboration we can detect.
400 if Nkind (Original_Node (Parent (P))) = N_Task_Body then
401 Check_Restriction (No_Allocators_After_Elaboration, N);
405 -- The other case is appearance in a subprogram body. This may
406 -- be a violation if this is a library level subprogram, and it
407 -- turns out to be used as the main program, but only the
408 -- binder knows that, so just record the occurrence.
410 if Nkind (Original_Node (Parent (P))) = N_Subprogram_Body
411 and then Nkind (Parent (Parent (P))) = N_Compilation_Unit
413 Set_Has_Allocator (Current_Sem_Unit);
422 -- Analyze the allocator
424 if Nkind (E) = N_Qualified_Expression then
425 Acc_Type := Create_Itype (E_Allocator_Type, N);
426 Set_Etype (Acc_Type, Acc_Type);
427 Find_Type (Subtype_Mark (E));
429 -- Analyze the qualified expression, and apply the name resolution
430 -- rule given in 4.7 (3).
433 Type_Id := Etype (E);
434 Set_Directly_Designated_Type (Acc_Type, Type_Id);
436 Resolve (Expression (E), Type_Id);
438 if Is_Limited_Type (Type_Id)
439 and then Comes_From_Source (N)
440 and then not In_Instance_Body
442 if not OK_For_Limited_Init (Type_Id, Expression (E)) then
443 Error_Msg_N ("initialization not allowed for limited types", N);
444 Explain_Limited_Type (Type_Id, N);
448 -- A qualified expression requires an exact match of the type,
449 -- class-wide matching is not allowed.
451 -- if Is_Class_Wide_Type (Type_Id)
452 -- and then Base_Type
453 -- (Etype (Expression (E))) /= Base_Type (Type_Id)
455 -- Wrong_Type (Expression (E), Type_Id);
458 Check_Non_Static_Context (Expression (E));
460 -- We don't analyze the qualified expression itself because it's
461 -- part of the allocator
463 Set_Etype (E, Type_Id);
465 -- Case where allocator has a subtype indication
470 Base_Typ : Entity_Id;
473 -- If the allocator includes a N_Subtype_Indication then a
474 -- constraint is present, otherwise the node is a subtype mark.
475 -- Introduce an explicit subtype declaration into the tree
476 -- defining some anonymous subtype and rewrite the allocator to
477 -- use this subtype rather than the subtype indication.
479 -- It is important to introduce the explicit subtype declaration
480 -- so that the bounds of the subtype indication are attached to
481 -- the tree in case the allocator is inside a generic unit.
483 if Nkind (E) = N_Subtype_Indication then
485 -- A constraint is only allowed for a composite type in Ada
486 -- 95. In Ada 83, a constraint is also allowed for an
487 -- access-to-composite type, but the constraint is ignored.
489 Find_Type (Subtype_Mark (E));
490 Base_Typ := Entity (Subtype_Mark (E));
492 if Is_Elementary_Type (Base_Typ) then
493 if not (Ada_Version = Ada_83
494 and then Is_Access_Type (Base_Typ))
496 Error_Msg_N ("constraint not allowed here", E);
498 if Nkind (Constraint (E)) =
499 N_Index_Or_Discriminant_Constraint
501 Error_Msg_N -- CODEFIX
502 ("\if qualified expression was meant, " &
503 "use apostrophe", Constraint (E));
507 -- Get rid of the bogus constraint:
509 Rewrite (E, New_Copy_Tree (Subtype_Mark (E)));
510 Analyze_Allocator (N);
513 -- Ada 2005, AI-363: if the designated type has a constrained
514 -- partial view, it cannot receive a discriminant constraint,
515 -- and the allocated object is unconstrained.
517 elsif Ada_Version >= Ada_2005
518 and then Has_Constrained_Partial_View (Base_Typ)
521 ("constraint no allowed when type " &
522 "has a constrained partial view", Constraint (E));
525 if Expander_Active then
526 Def_Id := Make_Temporary (Loc, 'S');
529 Make_Subtype_Declaration (Loc,
530 Defining_Identifier => Def_Id,
531 Subtype_Indication => Relocate_Node (E)));
533 if Sav_Errs /= Serious_Errors_Detected
534 and then Nkind (Constraint (E)) =
535 N_Index_Or_Discriminant_Constraint
537 Error_Msg_N -- CODEFIX
538 ("if qualified expression was meant, " &
539 "use apostrophe!", Constraint (E));
542 E := New_Occurrence_Of (Def_Id, Loc);
543 Rewrite (Expression (N), E);
547 Type_Id := Process_Subtype (E, N);
548 Acc_Type := Create_Itype (E_Allocator_Type, N);
549 Set_Etype (Acc_Type, Acc_Type);
550 Set_Directly_Designated_Type (Acc_Type, Type_Id);
551 Check_Fully_Declared (Type_Id, N);
553 -- Ada 2005 (AI-231): If the designated type is itself an access
554 -- type that excludes null, its default initialization will
555 -- be a null object, and we can insert an unconditional raise
556 -- before the allocator.
558 -- Ada 2012 (AI-104): A not null indication here is altogether
561 if Can_Never_Be_Null (Type_Id) then
563 Not_Null_Check : constant Node_Id :=
564 Make_Raise_Constraint_Error (Sloc (E),
565 Reason => CE_Null_Not_Allowed);
568 if Ada_Version >= Ada_2012 then
570 ("an uninitialized allocator cannot have"
571 & " a null exclusion", N);
573 elsif Expander_Active then
574 Insert_Action (N, Not_Null_Check);
575 Analyze (Not_Null_Check);
578 Error_Msg_N ("null value not allowed here?", E);
583 -- Check restriction against dynamically allocated protected
584 -- objects. Note that when limited aggregates are supported,
585 -- a similar test should be applied to an allocator with a
586 -- qualified expression ???
588 if Is_Protected_Type (Type_Id) then
589 Check_Restriction (No_Protected_Type_Allocators, N);
592 -- Check for missing initialization. Skip this check if we already
593 -- had errors on analyzing the allocator, since in that case these
594 -- are probably cascaded errors.
596 if Is_Indefinite_Subtype (Type_Id)
597 and then Serious_Errors_Detected = Sav_Errs
599 if Is_Class_Wide_Type (Type_Id) then
601 ("initialization required in class-wide allocation", N);
603 if Ada_Version < Ada_2005
604 and then Is_Limited_Type (Type_Id)
606 Error_Msg_N ("unconstrained allocation not allowed", N);
608 if Is_Array_Type (Type_Id) then
610 ("\constraint with array bounds required", N);
612 elsif Has_Unknown_Discriminants (Type_Id) then
615 else pragma Assert (Has_Discriminants (Type_Id));
617 ("\constraint with discriminant values required", N);
620 -- Limited Ada 2005 and general non-limited case
624 ("uninitialized unconstrained allocation not allowed",
627 if Is_Array_Type (Type_Id) then
629 ("\qualified expression or constraint with " &
630 "array bounds required", N);
632 elsif Has_Unknown_Discriminants (Type_Id) then
633 Error_Msg_N ("\qualified expression required", N);
635 else pragma Assert (Has_Discriminants (Type_Id));
637 ("\qualified expression or constraint with " &
638 "discriminant values required", N);
646 if Is_Abstract_Type (Type_Id) then
647 Error_Msg_N ("cannot allocate abstract object", E);
650 if Has_Task (Designated_Type (Acc_Type)) then
651 Check_Restriction (No_Tasking, N);
652 Check_Restriction (Max_Tasks, N);
653 Check_Restriction (No_Task_Allocators, N);
656 -- Check that an allocator of a nested access type doesn't create a
657 -- protected object when restriction No_Local_Protected_Objects applies.
658 -- We don't have an equivalent to Has_Task for protected types, so only
659 -- cases where the designated type itself is a protected type are
660 -- currently checked. ???
662 if Is_Protected_Type (Designated_Type (Acc_Type))
663 and then not Is_Library_Level_Entity (Acc_Type)
665 Check_Restriction (No_Local_Protected_Objects, N);
668 -- If the No_Streams restriction is set, check that the type of the
669 -- object is not, and does not contain, any subtype derived from
670 -- Ada.Streams.Root_Stream_Type. Note that we guard the call to
671 -- Has_Stream just for efficiency reasons. There is no point in
672 -- spending time on a Has_Stream check if the restriction is not set.
674 if Restriction_Check_Required (No_Streams) then
675 if Has_Stream (Designated_Type (Acc_Type)) then
676 Check_Restriction (No_Streams, N);
680 Set_Etype (N, Acc_Type);
682 if not Is_Library_Level_Entity (Acc_Type) then
683 Check_Restriction (No_Local_Allocators, N);
686 if Serious_Errors_Detected > Sav_Errs then
687 Set_Error_Posted (N);
688 Set_Etype (N, Any_Type);
690 end Analyze_Allocator;
692 ---------------------------
693 -- Analyze_Arithmetic_Op --
694 ---------------------------
696 procedure Analyze_Arithmetic_Op (N : Node_Id) is
697 L : constant Node_Id := Left_Opnd (N);
698 R : constant Node_Id := Right_Opnd (N);
702 Candidate_Type := Empty;
703 Analyze_Expression (L);
704 Analyze_Expression (R);
706 -- If the entity is already set, the node is the instantiation of a
707 -- generic node with a non-local reference, or was manufactured by a
708 -- call to Make_Op_xxx. In either case the entity is known to be valid,
709 -- and we do not need to collect interpretations, instead we just get
710 -- the single possible interpretation.
714 if Present (Op_Id) then
715 if Ekind (Op_Id) = E_Operator then
717 if Nkind_In (N, N_Op_Divide, N_Op_Mod, N_Op_Multiply, N_Op_Rem)
718 and then Treat_Fixed_As_Integer (N)
722 Set_Etype (N, Any_Type);
723 Find_Arithmetic_Types (L, R, Op_Id, N);
727 Set_Etype (N, Any_Type);
728 Add_One_Interp (N, Op_Id, Etype (Op_Id));
731 -- Entity is not already set, so we do need to collect interpretations
734 Op_Id := Get_Name_Entity_Id (Chars (N));
735 Set_Etype (N, Any_Type);
737 while Present (Op_Id) loop
738 if Ekind (Op_Id) = E_Operator
739 and then Present (Next_Entity (First_Entity (Op_Id)))
741 Find_Arithmetic_Types (L, R, Op_Id, N);
743 -- The following may seem superfluous, because an operator cannot
744 -- be generic, but this ignores the cleverness of the author of
747 elsif Is_Overloadable (Op_Id) then
748 Analyze_User_Defined_Binary_Op (N, Op_Id);
751 Op_Id := Homonym (Op_Id);
756 end Analyze_Arithmetic_Op;
762 -- Function, procedure, and entry calls are checked here. The Name in
763 -- the call may be overloaded. The actuals have been analyzed and may
764 -- themselves be overloaded. On exit from this procedure, the node N
765 -- may have zero, one or more interpretations. In the first case an
766 -- error message is produced. In the last case, the node is flagged
767 -- as overloaded and the interpretations are collected in All_Interp.
769 -- If the name is an Access_To_Subprogram, it cannot be overloaded, but
770 -- the type-checking is similar to that of other calls.
772 procedure Analyze_Call (N : Node_Id) is
773 Actuals : constant List_Id := Parameter_Associations (N);
778 Success : Boolean := False;
780 Deref : Boolean := False;
781 -- Flag indicates whether an interpretation of the prefix is a
782 -- parameterless call that returns an access_to_subprogram.
784 procedure Check_Mixed_Parameter_And_Named_Associations;
785 -- Check that parameter and named associations are not mixed. This is
786 -- a restriction in SPARK mode.
788 function Name_Denotes_Function return Boolean;
789 -- If the type of the name is an access to subprogram, this may be the
790 -- type of a name, or the return type of the function being called. If
791 -- the name is not an entity then it can denote a protected function.
792 -- Until we distinguish Etype from Return_Type, we must use this routine
793 -- to resolve the meaning of the name in the call.
795 procedure No_Interpretation;
796 -- Output error message when no valid interpretation exists
798 --------------------------------------------------
799 -- Check_Mixed_Parameter_And_Named_Associations --
800 --------------------------------------------------
802 procedure Check_Mixed_Parameter_And_Named_Associations is
804 Named_Seen : Boolean;
809 Actual := First (Actuals);
810 while Present (Actual) loop
811 case Nkind (Actual) is
812 when N_Parameter_Association =>
814 Check_SPARK_Restriction
815 ("named association cannot follow positional one",
825 end Check_Mixed_Parameter_And_Named_Associations;
827 ---------------------------
828 -- Name_Denotes_Function --
829 ---------------------------
831 function Name_Denotes_Function return Boolean is
833 if Is_Entity_Name (Nam) then
834 return Ekind (Entity (Nam)) = E_Function;
836 elsif Nkind (Nam) = N_Selected_Component then
837 return Ekind (Entity (Selector_Name (Nam))) = E_Function;
842 end Name_Denotes_Function;
844 -----------------------
845 -- No_Interpretation --
846 -----------------------
848 procedure No_Interpretation is
849 L : constant Boolean := Is_List_Member (N);
850 K : constant Node_Kind := Nkind (Parent (N));
853 -- If the node is in a list whose parent is not an expression then it
854 -- must be an attempted procedure call.
856 if L and then K not in N_Subexpr then
857 if Ekind (Entity (Nam)) = E_Generic_Procedure then
859 ("must instantiate generic procedure& before call",
863 ("procedure or entry name expected", Nam);
866 -- Check for tasking cases where only an entry call will do
869 and then Nkind_In (K, N_Entry_Call_Alternative,
870 N_Triggering_Alternative)
872 Error_Msg_N ("entry name expected", Nam);
874 -- Otherwise give general error message
877 Error_Msg_N ("invalid prefix in call", Nam);
879 end No_Interpretation;
881 -- Start of processing for Analyze_Call
884 if SPARK_Mode or else Restriction_Check_Required (SPARK) then
885 Check_Mixed_Parameter_And_Named_Associations;
888 -- Initialize the type of the result of the call to the error type,
889 -- which will be reset if the type is successfully resolved.
891 Set_Etype (N, Any_Type);
895 if not Is_Overloaded (Nam) then
897 -- Only one interpretation to check
899 if Ekind (Etype (Nam)) = E_Subprogram_Type then
900 Nam_Ent := Etype (Nam);
902 -- If the prefix is an access_to_subprogram, this may be an indirect
903 -- call. This is the case if the name in the call is not an entity
904 -- name, or if it is a function name in the context of a procedure
905 -- call. In this latter case, we have a call to a parameterless
906 -- function that returns a pointer_to_procedure which is the entity
907 -- being called. Finally, F (X) may be a call to a parameterless
908 -- function that returns a pointer to a function with parameters.
910 elsif Is_Access_Type (Etype (Nam))
911 and then Ekind (Designated_Type (Etype (Nam))) = E_Subprogram_Type
913 (not Name_Denotes_Function
914 or else Nkind (N) = N_Procedure_Call_Statement
916 (Nkind (Parent (N)) /= N_Explicit_Dereference
917 and then Is_Entity_Name (Nam)
918 and then No (First_Formal (Entity (Nam)))
919 and then Present (Actuals)))
921 Nam_Ent := Designated_Type (Etype (Nam));
922 Insert_Explicit_Dereference (Nam);
924 -- Selected component case. Simple entry or protected operation,
925 -- where the entry name is given by the selector name.
927 elsif Nkind (Nam) = N_Selected_Component then
928 Nam_Ent := Entity (Selector_Name (Nam));
930 if not Ekind_In (Nam_Ent, E_Entry,
935 Error_Msg_N ("name in call is not a callable entity", Nam);
936 Set_Etype (N, Any_Type);
940 -- If the name is an Indexed component, it can be a call to a member
941 -- of an entry family. The prefix must be a selected component whose
942 -- selector is the entry. Analyze_Procedure_Call normalizes several
943 -- kinds of call into this form.
945 elsif Nkind (Nam) = N_Indexed_Component then
946 if Nkind (Prefix (Nam)) = N_Selected_Component then
947 Nam_Ent := Entity (Selector_Name (Prefix (Nam)));
949 Error_Msg_N ("name in call is not a callable entity", Nam);
950 Set_Etype (N, Any_Type);
954 elsif not Is_Entity_Name (Nam) then
955 Error_Msg_N ("name in call is not a callable entity", Nam);
956 Set_Etype (N, Any_Type);
960 Nam_Ent := Entity (Nam);
962 -- If no interpretations, give error message
964 if not Is_Overloadable (Nam_Ent) then
970 -- Operations generated for RACW stub types are called only through
971 -- dispatching, and can never be the static interpretation of a call.
973 if Is_RACW_Stub_Type_Operation (Nam_Ent) then
978 Analyze_One_Call (N, Nam_Ent, True, Success);
980 -- If this is an indirect call, the return type of the access_to
981 -- subprogram may be an incomplete type. At the point of the call,
982 -- use the full type if available, and at the same time update the
983 -- return type of the access_to_subprogram.
986 and then Nkind (Nam) = N_Explicit_Dereference
987 and then Ekind (Etype (N)) = E_Incomplete_Type
988 and then Present (Full_View (Etype (N)))
990 Set_Etype (N, Full_View (Etype (N)));
991 Set_Etype (Nam_Ent, Etype (N));
995 -- An overloaded selected component must denote overloaded operations
996 -- of a concurrent type. The interpretations are attached to the
997 -- simple name of those operations.
999 if Nkind (Nam) = N_Selected_Component then
1000 Nam := Selector_Name (Nam);
1003 Get_First_Interp (Nam, X, It);
1005 while Present (It.Nam) loop
1009 -- Name may be call that returns an access to subprogram, or more
1010 -- generally an overloaded expression one of whose interpretations
1011 -- yields an access to subprogram. If the name is an entity, we do
1012 -- not dereference, because the node is a call that returns the
1013 -- access type: note difference between f(x), where the call may
1014 -- return an access subprogram type, and f(x)(y), where the type
1015 -- returned by the call to f is implicitly dereferenced to analyze
1018 if Is_Access_Type (Nam_Ent) then
1019 Nam_Ent := Designated_Type (Nam_Ent);
1021 elsif Is_Access_Type (Etype (Nam_Ent))
1023 (not Is_Entity_Name (Nam)
1024 or else Nkind (N) = N_Procedure_Call_Statement)
1025 and then Ekind (Designated_Type (Etype (Nam_Ent)))
1028 Nam_Ent := Designated_Type (Etype (Nam_Ent));
1030 if Is_Entity_Name (Nam) then
1035 -- If the call has been rewritten from a prefixed call, the first
1036 -- parameter has been analyzed, but may need a subsequent
1037 -- dereference, so skip its analysis now.
1039 if N /= Original_Node (N)
1040 and then Nkind (Original_Node (N)) = Nkind (N)
1041 and then Nkind (Name (N)) /= Nkind (Name (Original_Node (N)))
1042 and then Present (Parameter_Associations (N))
1043 and then Present (Etype (First (Parameter_Associations (N))))
1046 (N, Nam_Ent, False, Success, Skip_First => True);
1048 Analyze_One_Call (N, Nam_Ent, False, Success);
1051 -- If the interpretation succeeds, mark the proper type of the
1052 -- prefix (any valid candidate will do). If not, remove the
1053 -- candidate interpretation. This only needs to be done for
1054 -- overloaded protected operations, for other entities disambi-
1055 -- guation is done directly in Resolve.
1059 and then Nkind (Parent (N)) /= N_Explicit_Dereference
1061 Set_Entity (Nam, It.Nam);
1062 Insert_Explicit_Dereference (Nam);
1063 Set_Etype (Nam, Nam_Ent);
1066 Set_Etype (Nam, It.Typ);
1069 elsif Nkind_In (Name (N), N_Selected_Component,
1075 Get_Next_Interp (X, It);
1078 -- If the name is the result of a function call, it can only
1079 -- be a call to a function returning an access to subprogram.
1080 -- Insert explicit dereference.
1082 if Nkind (Nam) = N_Function_Call then
1083 Insert_Explicit_Dereference (Nam);
1086 if Etype (N) = Any_Type then
1088 -- None of the interpretations is compatible with the actuals
1090 Diagnose_Call (N, Nam);
1092 -- Special checks for uninstantiated put routines
1094 if Nkind (N) = N_Procedure_Call_Statement
1095 and then Is_Entity_Name (Nam)
1096 and then Chars (Nam) = Name_Put
1097 and then List_Length (Actuals) = 1
1100 Arg : constant Node_Id := First (Actuals);
1104 if Nkind (Arg) = N_Parameter_Association then
1105 Typ := Etype (Explicit_Actual_Parameter (Arg));
1110 if Is_Signed_Integer_Type (Typ) then
1112 ("possible missing instantiation of " &
1113 "'Text_'I'O.'Integer_'I'O!", Nam);
1115 elsif Is_Modular_Integer_Type (Typ) then
1117 ("possible missing instantiation of " &
1118 "'Text_'I'O.'Modular_'I'O!", Nam);
1120 elsif Is_Floating_Point_Type (Typ) then
1122 ("possible missing instantiation of " &
1123 "'Text_'I'O.'Float_'I'O!", Nam);
1125 elsif Is_Ordinary_Fixed_Point_Type (Typ) then
1127 ("possible missing instantiation of " &
1128 "'Text_'I'O.'Fixed_'I'O!", Nam);
1130 elsif Is_Decimal_Fixed_Point_Type (Typ) then
1132 ("possible missing instantiation of " &
1133 "'Text_'I'O.'Decimal_'I'O!", Nam);
1135 elsif Is_Enumeration_Type (Typ) then
1137 ("possible missing instantiation of " &
1138 "'Text_'I'O.'Enumeration_'I'O!", Nam);
1143 elsif not Is_Overloaded (N)
1144 and then Is_Entity_Name (Nam)
1146 -- Resolution yields a single interpretation. Verify that the
1147 -- reference has capitalization consistent with the declaration.
1149 Set_Entity_With_Style_Check (Nam, Entity (Nam));
1150 Generate_Reference (Entity (Nam), Nam);
1152 Set_Etype (Nam, Etype (Entity (Nam)));
1154 Remove_Abstract_Operations (N);
1161 -----------------------------
1162 -- Analyze_Case_Expression --
1163 -----------------------------
1165 procedure Analyze_Case_Expression (N : Node_Id) is
1166 Expr : constant Node_Id := Expression (N);
1167 FirstX : constant Node_Id := Expression (First (Alternatives (N)));
1169 Exp_Type : Entity_Id;
1170 Exp_Btype : Entity_Id;
1172 Dont_Care : Boolean;
1173 Others_Present : Boolean;
1175 procedure Non_Static_Choice_Error (Choice : Node_Id);
1176 -- Error routine invoked by the generic instantiation below when
1177 -- the case expression has a non static choice.
1179 package Case_Choices_Processing is new
1180 Generic_Choices_Processing
1181 (Get_Alternatives => Alternatives,
1182 Get_Choices => Discrete_Choices,
1183 Process_Empty_Choice => No_OP,
1184 Process_Non_Static_Choice => Non_Static_Choice_Error,
1185 Process_Associated_Node => No_OP);
1186 use Case_Choices_Processing;
1188 -----------------------------
1189 -- Non_Static_Choice_Error --
1190 -----------------------------
1192 procedure Non_Static_Choice_Error (Choice : Node_Id) is
1194 Flag_Non_Static_Expr
1195 ("choice given in case expression is not static!", Choice);
1196 end Non_Static_Choice_Error;
1198 -- Start of processing for Analyze_Case_Expression
1201 if Comes_From_Source (N) then
1202 Check_Compiler_Unit (N);
1205 Analyze_And_Resolve (Expr, Any_Discrete);
1206 Check_Unset_Reference (Expr);
1207 Exp_Type := Etype (Expr);
1208 Exp_Btype := Base_Type (Exp_Type);
1210 Alt := First (Alternatives (N));
1211 while Present (Alt) loop
1212 Analyze (Expression (Alt));
1216 if not Is_Overloaded (FirstX) then
1217 Set_Etype (N, Etype (FirstX));
1225 Set_Etype (N, Any_Type);
1227 Get_First_Interp (FirstX, I, It);
1228 while Present (It.Nam) loop
1230 -- For each interpretation of the first expression, we only
1231 -- add the interpretation if every other expression in the
1232 -- case expression alternatives has a compatible type.
1234 Alt := Next (First (Alternatives (N)));
1235 while Present (Alt) loop
1236 exit when not Has_Compatible_Type (Expression (Alt), It.Typ);
1241 Add_One_Interp (N, It.Typ, It.Typ);
1244 Get_Next_Interp (I, It);
1249 Exp_Btype := Base_Type (Exp_Type);
1251 -- The expression must be of a discrete type which must be determinable
1252 -- independently of the context in which the expression occurs, but
1253 -- using the fact that the expression must be of a discrete type.
1254 -- Moreover, the type this expression must not be a character literal
1255 -- (which is always ambiguous).
1257 -- If error already reported by Resolve, nothing more to do
1259 if Exp_Btype = Any_Discrete
1260 or else Exp_Btype = Any_Type
1264 elsif Exp_Btype = Any_Character then
1266 ("character literal as case expression is ambiguous", Expr);
1270 -- If the case expression is a formal object of mode in out, then
1271 -- treat it as having a nonstatic subtype by forcing use of the base
1272 -- type (which has to get passed to Check_Case_Choices below). Also
1273 -- use base type when the case expression is parenthesized.
1275 if Paren_Count (Expr) > 0
1276 or else (Is_Entity_Name (Expr)
1277 and then Ekind (Entity (Expr)) = E_Generic_In_Out_Parameter)
1279 Exp_Type := Exp_Btype;
1282 -- Call instantiated Analyze_Choices which does the rest of the work
1284 Analyze_Choices (N, Exp_Type, Dont_Care, Others_Present);
1286 if Exp_Type = Universal_Integer and then not Others_Present then
1288 ("case on universal integer requires OTHERS choice", Expr);
1290 end Analyze_Case_Expression;
1292 ---------------------------
1293 -- Analyze_Comparison_Op --
1294 ---------------------------
1296 procedure Analyze_Comparison_Op (N : Node_Id) is
1297 L : constant Node_Id := Left_Opnd (N);
1298 R : constant Node_Id := Right_Opnd (N);
1299 Op_Id : Entity_Id := Entity (N);
1302 Set_Etype (N, Any_Type);
1303 Candidate_Type := Empty;
1305 Analyze_Expression (L);
1306 Analyze_Expression (R);
1308 if Present (Op_Id) then
1309 if Ekind (Op_Id) = E_Operator then
1310 Find_Comparison_Types (L, R, Op_Id, N);
1312 Add_One_Interp (N, Op_Id, Etype (Op_Id));
1315 if Is_Overloaded (L) then
1316 Set_Etype (L, Intersect_Types (L, R));
1320 Op_Id := Get_Name_Entity_Id (Chars (N));
1321 while Present (Op_Id) loop
1322 if Ekind (Op_Id) = E_Operator then
1323 Find_Comparison_Types (L, R, Op_Id, N);
1325 Analyze_User_Defined_Binary_Op (N, Op_Id);
1328 Op_Id := Homonym (Op_Id);
1333 end Analyze_Comparison_Op;
1335 ---------------------------
1336 -- Analyze_Concatenation --
1337 ---------------------------
1339 procedure Analyze_Concatenation (N : Node_Id) is
1341 -- We wish to avoid deep recursion, because concatenations are often
1342 -- deeply nested, as in A&B&...&Z. Therefore, we walk down the left
1343 -- operands nonrecursively until we find something that is not a
1344 -- concatenation (A in this case), or has already been analyzed. We
1345 -- analyze that, and then walk back up the tree following Parent
1346 -- pointers, calling Analyze_Concatenation_Rest to do the rest of the
1347 -- work at each level. The Parent pointers allow us to avoid recursion,
1348 -- and thus avoid running out of memory.
1354 Candidate_Type := Empty;
1356 -- The following code is equivalent to:
1358 -- Set_Etype (N, Any_Type);
1359 -- Analyze_Expression (Left_Opnd (N));
1360 -- Analyze_Concatenation_Rest (N);
1362 -- where the Analyze_Expression call recurses back here if the left
1363 -- operand is a concatenation.
1365 -- Walk down left operands
1368 Set_Etype (NN, Any_Type);
1369 L := Left_Opnd (NN);
1370 exit when Nkind (L) /= N_Op_Concat or else Analyzed (L);
1374 -- Now (given the above example) NN is A&B and L is A
1376 -- First analyze L ...
1378 Analyze_Expression (L);
1380 -- ... then walk NN back up until we reach N (where we started), calling
1381 -- Analyze_Concatenation_Rest along the way.
1384 Analyze_Concatenation_Rest (NN);
1388 end Analyze_Concatenation;
1390 --------------------------------
1391 -- Analyze_Concatenation_Rest --
1392 --------------------------------
1394 -- If the only one-dimensional array type in scope is String,
1395 -- this is the resulting type of the operation. Otherwise there
1396 -- will be a concatenation operation defined for each user-defined
1397 -- one-dimensional array.
1399 procedure Analyze_Concatenation_Rest (N : Node_Id) is
1400 L : constant Node_Id := Left_Opnd (N);
1401 R : constant Node_Id := Right_Opnd (N);
1402 Op_Id : Entity_Id := Entity (N);
1407 Analyze_Expression (R);
1409 -- If the entity is present, the node appears in an instance, and
1410 -- denotes a predefined concatenation operation. The resulting type is
1411 -- obtained from the arguments when possible. If the arguments are
1412 -- aggregates, the array type and the concatenation type must be
1415 if Present (Op_Id) then
1416 if Ekind (Op_Id) = E_Operator then
1417 LT := Base_Type (Etype (L));
1418 RT := Base_Type (Etype (R));
1420 if Is_Array_Type (LT)
1421 and then (RT = LT or else RT = Base_Type (Component_Type (LT)))
1423 Add_One_Interp (N, Op_Id, LT);
1425 elsif Is_Array_Type (RT)
1426 and then LT = Base_Type (Component_Type (RT))
1428 Add_One_Interp (N, Op_Id, RT);
1430 -- If one operand is a string type or a user-defined array type,
1431 -- and the other is a literal, result is of the specific type.
1434 (Root_Type (LT) = Standard_String
1435 or else Scope (LT) /= Standard_Standard)
1436 and then Etype (R) = Any_String
1438 Add_One_Interp (N, Op_Id, LT);
1441 (Root_Type (RT) = Standard_String
1442 or else Scope (RT) /= Standard_Standard)
1443 and then Etype (L) = Any_String
1445 Add_One_Interp (N, Op_Id, RT);
1447 elsif not Is_Generic_Type (Etype (Op_Id)) then
1448 Add_One_Interp (N, Op_Id, Etype (Op_Id));
1451 -- Type and its operations must be visible
1453 Set_Entity (N, Empty);
1454 Analyze_Concatenation (N);
1458 Add_One_Interp (N, Op_Id, Etype (Op_Id));
1462 Op_Id := Get_Name_Entity_Id (Name_Op_Concat);
1463 while Present (Op_Id) loop
1464 if Ekind (Op_Id) = E_Operator then
1466 -- Do not consider operators declared in dead code, they can
1467 -- not be part of the resolution.
1469 if Is_Eliminated (Op_Id) then
1472 Find_Concatenation_Types (L, R, Op_Id, N);
1476 Analyze_User_Defined_Binary_Op (N, Op_Id);
1479 Op_Id := Homonym (Op_Id);
1484 end Analyze_Concatenation_Rest;
1486 ------------------------------------
1487 -- Analyze_Conditional_Expression --
1488 ------------------------------------
1490 procedure Analyze_Conditional_Expression (N : Node_Id) is
1491 Condition : constant Node_Id := First (Expressions (N));
1492 Then_Expr : constant Node_Id := Next (Condition);
1493 Else_Expr : Node_Id;
1496 -- Defend against error of missing expressions from previous error
1498 if No (Then_Expr) then
1502 Check_SPARK_Restriction ("conditional expression is not allowed", N);
1504 Else_Expr := Next (Then_Expr);
1506 if Comes_From_Source (N) then
1507 Check_Compiler_Unit (N);
1510 Analyze_Expression (Condition);
1511 Analyze_Expression (Then_Expr);
1513 if Present (Else_Expr) then
1514 Analyze_Expression (Else_Expr);
1517 -- If then expression not overloaded, then that decides the type
1519 if not Is_Overloaded (Then_Expr) then
1520 Set_Etype (N, Etype (Then_Expr));
1522 -- Case where then expression is overloaded
1530 Set_Etype (N, Any_Type);
1532 -- Shouldn't the following statement be down in the ELSE of the
1533 -- following loop? ???
1535 Get_First_Interp (Then_Expr, I, It);
1537 -- if no Else_Expression the conditional must be boolean
1539 if No (Else_Expr) then
1540 Set_Etype (N, Standard_Boolean);
1542 -- Else_Expression Present. For each possible intepretation of
1543 -- the Then_Expression, add it only if the Else_Expression has
1544 -- a compatible type.
1547 while Present (It.Nam) loop
1548 if Has_Compatible_Type (Else_Expr, It.Typ) then
1549 Add_One_Interp (N, It.Typ, It.Typ);
1552 Get_Next_Interp (I, It);
1557 end Analyze_Conditional_Expression;
1559 -------------------------
1560 -- Analyze_Equality_Op --
1561 -------------------------
1563 procedure Analyze_Equality_Op (N : Node_Id) is
1564 Loc : constant Source_Ptr := Sloc (N);
1565 L : constant Node_Id := Left_Opnd (N);
1566 R : constant Node_Id := Right_Opnd (N);
1570 Set_Etype (N, Any_Type);
1571 Candidate_Type := Empty;
1573 Analyze_Expression (L);
1574 Analyze_Expression (R);
1576 -- If the entity is set, the node is a generic instance with a non-local
1577 -- reference to the predefined operator or to a user-defined function.
1578 -- It can also be an inequality that is expanded into the negation of a
1579 -- call to a user-defined equality operator.
1581 -- For the predefined case, the result is Boolean, regardless of the
1582 -- type of the operands. The operands may even be limited, if they are
1583 -- generic actuals. If they are overloaded, label the left argument with
1584 -- the common type that must be present, or with the type of the formal
1585 -- of the user-defined function.
1587 if Present (Entity (N)) then
1588 Op_Id := Entity (N);
1590 if Ekind (Op_Id) = E_Operator then
1591 Add_One_Interp (N, Op_Id, Standard_Boolean);
1593 Add_One_Interp (N, Op_Id, Etype (Op_Id));
1596 if Is_Overloaded (L) then
1597 if Ekind (Op_Id) = E_Operator then
1598 Set_Etype (L, Intersect_Types (L, R));
1600 Set_Etype (L, Etype (First_Formal (Op_Id)));
1605 Op_Id := Get_Name_Entity_Id (Chars (N));
1606 while Present (Op_Id) loop
1607 if Ekind (Op_Id) = E_Operator then
1608 Find_Equality_Types (L, R, Op_Id, N);
1610 Analyze_User_Defined_Binary_Op (N, Op_Id);
1613 Op_Id := Homonym (Op_Id);
1617 -- If there was no match, and the operator is inequality, this may
1618 -- be a case where inequality has not been made explicit, as for
1619 -- tagged types. Analyze the node as the negation of an equality
1620 -- operation. This cannot be done earlier, because before analysis
1621 -- we cannot rule out the presence of an explicit inequality.
1623 if Etype (N) = Any_Type
1624 and then Nkind (N) = N_Op_Ne
1626 Op_Id := Get_Name_Entity_Id (Name_Op_Eq);
1627 while Present (Op_Id) loop
1628 if Ekind (Op_Id) = E_Operator then
1629 Find_Equality_Types (L, R, Op_Id, N);
1631 Analyze_User_Defined_Binary_Op (N, Op_Id);
1634 Op_Id := Homonym (Op_Id);
1637 if Etype (N) /= Any_Type then
1638 Op_Id := Entity (N);
1644 Left_Opnd => Left_Opnd (N),
1645 Right_Opnd => Right_Opnd (N))));
1647 Set_Entity (Right_Opnd (N), Op_Id);
1653 end Analyze_Equality_Op;
1655 ----------------------------------
1656 -- Analyze_Explicit_Dereference --
1657 ----------------------------------
1659 procedure Analyze_Explicit_Dereference (N : Node_Id) is
1660 Loc : constant Source_Ptr := Sloc (N);
1661 P : constant Node_Id := Prefix (N);
1667 function Is_Function_Type return Boolean;
1668 -- Check whether node may be interpreted as an implicit function call
1670 ----------------------
1671 -- Is_Function_Type --
1672 ----------------------
1674 function Is_Function_Type return Boolean is
1679 if not Is_Overloaded (N) then
1680 return Ekind (Base_Type (Etype (N))) = E_Subprogram_Type
1681 and then Etype (Base_Type (Etype (N))) /= Standard_Void_Type;
1684 Get_First_Interp (N, I, It);
1685 while Present (It.Nam) loop
1686 if Ekind (Base_Type (It.Typ)) /= E_Subprogram_Type
1687 or else Etype (Base_Type (It.Typ)) = Standard_Void_Type
1692 Get_Next_Interp (I, It);
1697 end Is_Function_Type;
1699 -- Start of processing for Analyze_Explicit_Dereference
1702 Check_SPARK_Restriction ("explicit dereference is not allowed", N);
1705 Set_Etype (N, Any_Type);
1707 -- Test for remote access to subprogram type, and if so return
1708 -- after rewriting the original tree.
1710 if Remote_AST_E_Dereference (P) then
1714 -- Normal processing for other than remote access to subprogram type
1716 if not Is_Overloaded (P) then
1717 if Is_Access_Type (Etype (P)) then
1719 -- Set the Etype. We need to go through Is_For_Access_Subtypes to
1720 -- avoid other problems caused by the Private_Subtype and it is
1721 -- safe to go to the Base_Type because this is the same as
1722 -- converting the access value to its Base_Type.
1725 DT : Entity_Id := Designated_Type (Etype (P));
1728 if Ekind (DT) = E_Private_Subtype
1729 and then Is_For_Access_Subtype (DT)
1731 DT := Base_Type (DT);
1734 -- An explicit dereference is a legal occurrence of an
1735 -- incomplete type imported through a limited_with clause,
1736 -- if the full view is visible.
1738 if From_With_Type (DT)
1739 and then not From_With_Type (Scope (DT))
1741 (Is_Immediately_Visible (Scope (DT))
1743 (Is_Child_Unit (Scope (DT))
1744 and then Is_Visible_Child_Unit (Scope (DT))))
1746 Set_Etype (N, Available_View (DT));
1753 elsif Etype (P) /= Any_Type then
1754 Error_Msg_N ("prefix of dereference must be an access type", N);
1759 Get_First_Interp (P, I, It);
1760 while Present (It.Nam) loop
1763 if Is_Access_Type (T) then
1764 Add_One_Interp (N, Designated_Type (T), Designated_Type (T));
1767 Get_Next_Interp (I, It);
1770 -- Error if no interpretation of the prefix has an access type
1772 if Etype (N) = Any_Type then
1774 ("access type required in prefix of explicit dereference", P);
1775 Set_Etype (N, Any_Type);
1781 and then Nkind (Parent (N)) /= N_Indexed_Component
1783 and then (Nkind (Parent (N)) /= N_Function_Call
1784 or else N /= Name (Parent (N)))
1786 and then (Nkind (Parent (N)) /= N_Procedure_Call_Statement
1787 or else N /= Name (Parent (N)))
1789 and then Nkind (Parent (N)) /= N_Subprogram_Renaming_Declaration
1790 and then (Nkind (Parent (N)) /= N_Attribute_Reference
1792 (Attribute_Name (Parent (N)) /= Name_Address
1794 Attribute_Name (Parent (N)) /= Name_Access))
1796 -- Name is a function call with no actuals, in a context that
1797 -- requires deproceduring (including as an actual in an enclosing
1798 -- function or procedure call). There are some pathological cases
1799 -- where the prefix might include functions that return access to
1800 -- subprograms and others that return a regular type. Disambiguation
1801 -- of those has to take place in Resolve.
1804 Make_Function_Call (Loc,
1805 Name => Make_Explicit_Dereference (Loc, P),
1806 Parameter_Associations => New_List);
1808 -- If the prefix is overloaded, remove operations that have formals,
1809 -- we know that this is a parameterless call.
1811 if Is_Overloaded (P) then
1812 Get_First_Interp (P, I, It);
1813 while Present (It.Nam) loop
1816 if No (First_Formal (Base_Type (Designated_Type (T)))) then
1822 Get_Next_Interp (I, It);
1829 elsif not Is_Function_Type
1830 and then Is_Overloaded (N)
1832 -- The prefix may include access to subprograms and other access
1833 -- types. If the context selects the interpretation that is a
1834 -- function call (not a procedure call) we cannot rewrite the node
1835 -- yet, but we include the result of the call interpretation.
1837 Get_First_Interp (N, I, It);
1838 while Present (It.Nam) loop
1839 if Ekind (Base_Type (It.Typ)) = E_Subprogram_Type
1840 and then Etype (Base_Type (It.Typ)) /= Standard_Void_Type
1841 and then Nkind (Parent (N)) /= N_Procedure_Call_Statement
1843 Add_One_Interp (N, Etype (It.Typ), Etype (It.Typ));
1846 Get_Next_Interp (I, It);
1850 -- A value of remote access-to-class-wide must not be dereferenced
1853 Validate_Remote_Access_To_Class_Wide_Type (N);
1854 end Analyze_Explicit_Dereference;
1856 ------------------------
1857 -- Analyze_Expression --
1858 ------------------------
1860 procedure Analyze_Expression (N : Node_Id) is
1863 Check_Parameterless_Call (N);
1864 end Analyze_Expression;
1866 -------------------------------------
1867 -- Analyze_Expression_With_Actions --
1868 -------------------------------------
1870 procedure Analyze_Expression_With_Actions (N : Node_Id) is
1874 A := First (Actions (N));
1881 Analyze_Expression (Expression (N));
1882 Set_Etype (N, Etype (Expression (N)));
1883 end Analyze_Expression_With_Actions;
1885 ------------------------------------
1886 -- Analyze_Indexed_Component_Form --
1887 ------------------------------------
1889 procedure Analyze_Indexed_Component_Form (N : Node_Id) is
1890 P : constant Node_Id := Prefix (N);
1891 Exprs : constant List_Id := Expressions (N);
1897 procedure Process_Function_Call;
1898 -- Prefix in indexed component form is an overloadable entity,
1899 -- so the node is a function call. Reformat it as such.
1901 procedure Process_Indexed_Component;
1902 -- Prefix in indexed component form is actually an indexed component.
1903 -- This routine processes it, knowing that the prefix is already
1906 procedure Process_Indexed_Component_Or_Slice;
1907 -- An indexed component with a single index may designate a slice if
1908 -- the index is a subtype mark. This routine disambiguates these two
1909 -- cases by resolving the prefix to see if it is a subtype mark.
1911 procedure Process_Overloaded_Indexed_Component;
1912 -- If the prefix of an indexed component is overloaded, the proper
1913 -- interpretation is selected by the index types and the context.
1915 ---------------------------
1916 -- Process_Function_Call --
1917 ---------------------------
1919 procedure Process_Function_Call is
1923 Change_Node (N, N_Function_Call);
1925 Set_Parameter_Associations (N, Exprs);
1927 -- Analyze actuals prior to analyzing the call itself
1929 Actual := First (Parameter_Associations (N));
1930 while Present (Actual) loop
1932 Check_Parameterless_Call (Actual);
1934 -- Move to next actual. Note that we use Next, not Next_Actual
1935 -- here. The reason for this is a bit subtle. If a function call
1936 -- includes named associations, the parser recognizes the node as
1937 -- a call, and it is analyzed as such. If all associations are
1938 -- positional, the parser builds an indexed_component node, and
1939 -- it is only after analysis of the prefix that the construct
1940 -- is recognized as a call, in which case Process_Function_Call
1941 -- rewrites the node and analyzes the actuals. If the list of
1942 -- actuals is malformed, the parser may leave the node as an
1943 -- indexed component (despite the presence of named associations).
1944 -- The iterator Next_Actual is equivalent to Next if the list is
1945 -- positional, but follows the normalized chain of actuals when
1946 -- named associations are present. In this case normalization has
1947 -- not taken place, and actuals remain unanalyzed, which leads to
1948 -- subsequent crashes or loops if there is an attempt to continue
1949 -- analysis of the program.
1955 end Process_Function_Call;
1957 -------------------------------
1958 -- Process_Indexed_Component --
1959 -------------------------------
1961 procedure Process_Indexed_Component is
1963 Array_Type : Entity_Id;
1965 Pent : Entity_Id := Empty;
1968 Exp := First (Exprs);
1970 if Is_Overloaded (P) then
1971 Process_Overloaded_Indexed_Component;
1974 Array_Type := Etype (P);
1976 if Is_Entity_Name (P) then
1978 elsif Nkind (P) = N_Selected_Component
1979 and then Is_Entity_Name (Selector_Name (P))
1981 Pent := Entity (Selector_Name (P));
1984 -- Prefix must be appropriate for an array type, taking into
1985 -- account a possible implicit dereference.
1987 if Is_Access_Type (Array_Type) then
1988 Error_Msg_NW (Warn_On_Dereference, "?implicit dereference", N);
1989 Array_Type := Process_Implicit_Dereference_Prefix (Pent, P);
1992 if Is_Array_Type (Array_Type) then
1995 elsif Present (Pent) and then Ekind (Pent) = E_Entry_Family then
1997 Set_Etype (N, Any_Type);
1999 if not Has_Compatible_Type
2000 (Exp, Entry_Index_Type (Pent))
2002 Error_Msg_N ("invalid index type in entry name", N);
2004 elsif Present (Next (Exp)) then
2005 Error_Msg_N ("too many subscripts in entry reference", N);
2008 Set_Etype (N, Etype (P));
2013 elsif Is_Record_Type (Array_Type)
2014 and then Remote_AST_I_Dereference (P)
2018 elsif Array_Type = Any_Type then
2019 Set_Etype (N, Any_Type);
2021 -- In most cases the analysis of the prefix will have emitted
2022 -- an error already, but if the prefix may be interpreted as a
2023 -- call in prefixed notation, the report is left to the caller.
2024 -- To prevent cascaded errors, report only if no previous ones.
2026 if Serious_Errors_Detected = 0 then
2027 Error_Msg_N ("invalid prefix in indexed component", P);
2029 if Nkind (P) = N_Expanded_Name then
2030 Error_Msg_NE ("\& is not visible", P, Selector_Name (P));
2036 -- Here we definitely have a bad indexing
2039 if Nkind (Parent (N)) = N_Requeue_Statement
2040 and then Present (Pent) and then Ekind (Pent) = E_Entry
2043 ("REQUEUE does not permit parameters", First (Exprs));
2045 elsif Is_Entity_Name (P)
2046 and then Etype (P) = Standard_Void_Type
2048 Error_Msg_NE ("incorrect use of&", P, Entity (P));
2051 Error_Msg_N ("array type required in indexed component", P);
2054 Set_Etype (N, Any_Type);
2058 Index := First_Index (Array_Type);
2059 while Present (Index) and then Present (Exp) loop
2060 if not Has_Compatible_Type (Exp, Etype (Index)) then
2061 Wrong_Type (Exp, Etype (Index));
2062 Set_Etype (N, Any_Type);
2070 Set_Etype (N, Component_Type (Array_Type));
2072 if Present (Index) then
2074 ("too few subscripts in array reference", First (Exprs));
2076 elsif Present (Exp) then
2077 Error_Msg_N ("too many subscripts in array reference", Exp);
2080 end Process_Indexed_Component;
2082 ----------------------------------------
2083 -- Process_Indexed_Component_Or_Slice --
2084 ----------------------------------------
2086 procedure Process_Indexed_Component_Or_Slice is
2088 Exp := First (Exprs);
2089 while Present (Exp) loop
2090 Analyze_Expression (Exp);
2094 Exp := First (Exprs);
2096 -- If one index is present, and it is a subtype name, then the
2097 -- node denotes a slice (note that the case of an explicit range
2098 -- for a slice was already built as an N_Slice node in the first
2099 -- place, so that case is not handled here).
2101 -- We use a replace rather than a rewrite here because this is one
2102 -- of the cases in which the tree built by the parser is plain wrong.
2105 and then Is_Entity_Name (Exp)
2106 and then Is_Type (Entity (Exp))
2109 Make_Slice (Sloc (N),
2111 Discrete_Range => New_Copy (Exp)));
2114 -- Otherwise (more than one index present, or single index is not
2115 -- a subtype name), then we have the indexed component case.
2118 Process_Indexed_Component;
2120 end Process_Indexed_Component_Or_Slice;
2122 ------------------------------------------
2123 -- Process_Overloaded_Indexed_Component --
2124 ------------------------------------------
2126 procedure Process_Overloaded_Indexed_Component is
2135 Set_Etype (N, Any_Type);
2137 Get_First_Interp (P, I, It);
2138 while Present (It.Nam) loop
2141 if Is_Access_Type (Typ) then
2142 Typ := Designated_Type (Typ);
2143 Error_Msg_NW (Warn_On_Dereference, "?implicit dereference", N);
2146 if Is_Array_Type (Typ) then
2148 -- Got a candidate: verify that index types are compatible
2150 Index := First_Index (Typ);
2152 Exp := First (Exprs);
2153 while Present (Index) and then Present (Exp) loop
2154 if Has_Compatible_Type (Exp, Etype (Index)) then
2166 if Found and then No (Index) and then No (Exp) then
2168 Etype (Component_Type (Typ)),
2169 Etype (Component_Type (Typ)));
2173 Get_Next_Interp (I, It);
2176 if Etype (N) = Any_Type then
2177 Error_Msg_N ("no legal interpretation for indexed component", N);
2178 Set_Is_Overloaded (N, False);
2182 end Process_Overloaded_Indexed_Component;
2184 -- Start of processing for Analyze_Indexed_Component_Form
2187 -- Get name of array, function or type
2191 if Nkind_In (N, N_Function_Call, N_Procedure_Call_Statement) then
2193 -- If P is an explicit dereference whose prefix is of a
2194 -- remote access-to-subprogram type, then N has already
2195 -- been rewritten as a subprogram call and analyzed.
2200 pragma Assert (Nkind (N) = N_Indexed_Component);
2202 P_T := Base_Type (Etype (P));
2204 if Is_Entity_Name (P) and then Present (Entity (P)) then
2207 if Is_Type (U_N) then
2209 -- Reformat node as a type conversion
2211 E := Remove_Head (Exprs);
2213 if Present (First (Exprs)) then
2215 ("argument of type conversion must be single expression", N);
2218 Change_Node (N, N_Type_Conversion);
2219 Set_Subtype_Mark (N, P);
2221 Set_Expression (N, E);
2223 -- After changing the node, call for the specific Analysis
2224 -- routine directly, to avoid a double call to the expander.
2226 Analyze_Type_Conversion (N);
2230 if Is_Overloadable (U_N) then
2231 Process_Function_Call;
2233 elsif Ekind (Etype (P)) = E_Subprogram_Type
2234 or else (Is_Access_Type (Etype (P))
2236 Ekind (Designated_Type (Etype (P))) =
2239 -- Call to access_to-subprogram with possible implicit dereference
2241 Process_Function_Call;
2243 elsif Is_Generic_Subprogram (U_N) then
2245 -- A common beginner's (or C++ templates fan) error
2247 Error_Msg_N ("generic subprogram cannot be called", N);
2248 Set_Etype (N, Any_Type);
2252 Process_Indexed_Component_Or_Slice;
2255 -- If not an entity name, prefix is an expression that may denote
2256 -- an array or an access-to-subprogram.
2259 if Ekind (P_T) = E_Subprogram_Type
2260 or else (Is_Access_Type (P_T)
2262 Ekind (Designated_Type (P_T)) = E_Subprogram_Type)
2264 Process_Function_Call;
2266 elsif Nkind (P) = N_Selected_Component
2267 and then Is_Overloadable (Entity (Selector_Name (P)))
2269 Process_Function_Call;
2272 -- Indexed component, slice, or a call to a member of a family
2273 -- entry, which will be converted to an entry call later.
2275 Process_Indexed_Component_Or_Slice;
2278 end Analyze_Indexed_Component_Form;
2280 ------------------------
2281 -- Analyze_Logical_Op --
2282 ------------------------
2284 procedure Analyze_Logical_Op (N : Node_Id) is
2285 L : constant Node_Id := Left_Opnd (N);
2286 R : constant Node_Id := Right_Opnd (N);
2287 Op_Id : Entity_Id := Entity (N);
2290 Set_Etype (N, Any_Type);
2291 Candidate_Type := Empty;
2293 Analyze_Expression (L);
2294 Analyze_Expression (R);
2296 if Present (Op_Id) then
2298 if Ekind (Op_Id) = E_Operator then
2299 Find_Boolean_Types (L, R, Op_Id, N);
2301 Add_One_Interp (N, Op_Id, Etype (Op_Id));
2305 Op_Id := Get_Name_Entity_Id (Chars (N));
2306 while Present (Op_Id) loop
2307 if Ekind (Op_Id) = E_Operator then
2308 Find_Boolean_Types (L, R, Op_Id, N);
2310 Analyze_User_Defined_Binary_Op (N, Op_Id);
2313 Op_Id := Homonym (Op_Id);
2318 end Analyze_Logical_Op;
2320 ---------------------------
2321 -- Analyze_Membership_Op --
2322 ---------------------------
2324 procedure Analyze_Membership_Op (N : Node_Id) is
2325 Loc : constant Source_Ptr := Sloc (N);
2326 L : constant Node_Id := Left_Opnd (N);
2327 R : constant Node_Id := Right_Opnd (N);
2329 Index : Interp_Index;
2331 Found : Boolean := False;
2335 procedure Try_One_Interp (T1 : Entity_Id);
2336 -- Routine to try one proposed interpretation. Note that the context
2337 -- of the operation plays no role in resolving the arguments, so that
2338 -- if there is more than one interpretation of the operands that is
2339 -- compatible with a membership test, the operation is ambiguous.
2341 --------------------
2342 -- Try_One_Interp --
2343 --------------------
2345 procedure Try_One_Interp (T1 : Entity_Id) is
2347 if Has_Compatible_Type (R, T1) then
2349 and then Base_Type (T1) /= Base_Type (T_F)
2351 It := Disambiguate (L, I_F, Index, Any_Type);
2353 if It = No_Interp then
2354 Ambiguous_Operands (N);
2355 Set_Etype (L, Any_Type);
2372 procedure Analyze_Set_Membership;
2373 -- If a set of alternatives is present, analyze each and find the
2374 -- common type to which they must all resolve.
2376 ----------------------------
2377 -- Analyze_Set_Membership --
2378 ----------------------------
2380 procedure Analyze_Set_Membership is
2382 Index : Interp_Index;
2384 Candidate_Interps : Node_Id;
2385 Common_Type : Entity_Id := Empty;
2389 Candidate_Interps := L;
2391 if not Is_Overloaded (L) then
2392 Common_Type := Etype (L);
2394 Alt := First (Alternatives (N));
2395 while Present (Alt) loop
2398 if not Has_Compatible_Type (Alt, Common_Type) then
2399 Wrong_Type (Alt, Common_Type);
2406 Alt := First (Alternatives (N));
2407 while Present (Alt) loop
2409 if not Is_Overloaded (Alt) then
2410 Common_Type := Etype (Alt);
2413 Get_First_Interp (Alt, Index, It);
2414 while Present (It.Typ) loop
2416 Has_Compatible_Type (Candidate_Interps, It.Typ)
2418 Remove_Interp (Index);
2421 Get_Next_Interp (Index, It);
2424 Get_First_Interp (Alt, Index, It);
2427 Error_Msg_N ("alternative has no legal type", Alt);
2431 -- If alternative is not overloaded, we have a unique type
2434 Set_Etype (Alt, It.Typ);
2435 Get_Next_Interp (Index, It);
2438 Set_Is_Overloaded (Alt, False);
2439 Common_Type := Etype (Alt);
2442 Candidate_Interps := Alt;
2449 Set_Etype (N, Standard_Boolean);
2451 if Present (Common_Type) then
2452 Set_Etype (L, Common_Type);
2453 Set_Is_Overloaded (L, False);
2456 Error_Msg_N ("cannot resolve membership operation", N);
2458 end Analyze_Set_Membership;
2460 -- Start of processing for Analyze_Membership_Op
2463 Analyze_Expression (L);
2466 and then Ada_Version >= Ada_2012
2468 Analyze_Set_Membership;
2472 if Nkind (R) = N_Range
2473 or else (Nkind (R) = N_Attribute_Reference
2474 and then Attribute_Name (R) = Name_Range)
2478 if not Is_Overloaded (L) then
2479 Try_One_Interp (Etype (L));
2482 Get_First_Interp (L, Index, It);
2483 while Present (It.Typ) loop
2484 Try_One_Interp (It.Typ);
2485 Get_Next_Interp (Index, It);
2489 -- If not a range, it can be a subtype mark, or else it is a degenerate
2490 -- membership test with a singleton value, i.e. a test for equality,
2491 -- if the types are compatible.
2495 if Is_Entity_Name (R)
2496 and then Is_Type (Entity (R))
2499 Check_Fully_Declared (Entity (R), R);
2501 elsif Ada_Version >= Ada_2012
2502 and then Has_Compatible_Type (R, Etype (L))
2504 if Nkind (N) = N_In then
2520 -- In all versions of the language, if we reach this point there
2521 -- is a previous error that will be diagnosed below.
2527 -- Compatibility between expression and subtype mark or range is
2528 -- checked during resolution. The result of the operation is Boolean
2531 Set_Etype (N, Standard_Boolean);
2533 if Comes_From_Source (N)
2534 and then Present (Right_Opnd (N))
2535 and then Is_CPP_Class (Etype (Etype (Right_Opnd (N))))
2537 Error_Msg_N ("membership test not applicable to cpp-class types", N);
2539 end Analyze_Membership_Op;
2541 ----------------------
2542 -- Analyze_Negation --
2543 ----------------------
2545 procedure Analyze_Negation (N : Node_Id) is
2546 R : constant Node_Id := Right_Opnd (N);
2547 Op_Id : Entity_Id := Entity (N);
2550 Set_Etype (N, Any_Type);
2551 Candidate_Type := Empty;
2553 Analyze_Expression (R);
2555 if Present (Op_Id) then
2556 if Ekind (Op_Id) = E_Operator then
2557 Find_Negation_Types (R, Op_Id, N);
2559 Add_One_Interp (N, Op_Id, Etype (Op_Id));
2563 Op_Id := Get_Name_Entity_Id (Chars (N));
2564 while Present (Op_Id) loop
2565 if Ekind (Op_Id) = E_Operator then
2566 Find_Negation_Types (R, Op_Id, N);
2568 Analyze_User_Defined_Unary_Op (N, Op_Id);
2571 Op_Id := Homonym (Op_Id);
2576 end Analyze_Negation;
2582 procedure Analyze_Null (N : Node_Id) is
2584 Check_SPARK_Restriction ("null is not allowed", N);
2586 Set_Etype (N, Any_Access);
2589 ----------------------
2590 -- Analyze_One_Call --
2591 ----------------------
2593 procedure Analyze_One_Call
2597 Success : out Boolean;
2598 Skip_First : Boolean := False)
2600 Actuals : constant List_Id := Parameter_Associations (N);
2601 Prev_T : constant Entity_Id := Etype (N);
2603 Must_Skip : constant Boolean := Skip_First
2604 or else Nkind (Original_Node (N)) = N_Selected_Component
2606 (Nkind (Original_Node (N)) = N_Indexed_Component
2607 and then Nkind (Prefix (Original_Node (N)))
2608 = N_Selected_Component);
2609 -- The first formal must be omitted from the match when trying to find
2610 -- a primitive operation that is a possible interpretation, and also
2611 -- after the call has been rewritten, because the corresponding actual
2612 -- is already known to be compatible, and because this may be an
2613 -- indexing of a call with default parameters.
2617 Is_Indexed : Boolean := False;
2618 Is_Indirect : Boolean := False;
2619 Subp_Type : constant Entity_Id := Etype (Nam);
2622 function Operator_Hidden_By (Fun : Entity_Id) return Boolean;
2623 -- There may be a user-defined operator that hides the current
2624 -- interpretation. We must check for this independently of the
2625 -- analysis of the call with the user-defined operation, because
2626 -- the parameter names may be wrong and yet the hiding takes place.
2627 -- This fixes a problem with ACATS test B34014O.
2629 -- When the type Address is a visible integer type, and the DEC
2630 -- system extension is visible, the predefined operator may be
2631 -- hidden as well, by one of the address operations in auxdec.
2632 -- Finally, The abstract operations on address do not hide the
2633 -- predefined operator (this is the purpose of making them abstract).
2635 procedure Indicate_Name_And_Type;
2636 -- If candidate interpretation matches, indicate name and type of
2637 -- result on call node.
2639 ----------------------------
2640 -- Indicate_Name_And_Type --
2641 ----------------------------
2643 procedure Indicate_Name_And_Type is
2645 Add_One_Interp (N, Nam, Etype (Nam));
2648 -- If the prefix of the call is a name, indicate the entity
2649 -- being called. If it is not a name, it is an expression that
2650 -- denotes an access to subprogram or else an entry or family. In
2651 -- the latter case, the name is a selected component, and the entity
2652 -- being called is noted on the selector.
2654 if not Is_Type (Nam) then
2655 if Is_Entity_Name (Name (N)) then
2656 Set_Entity (Name (N), Nam);
2658 elsif Nkind (Name (N)) = N_Selected_Component then
2659 Set_Entity (Selector_Name (Name (N)), Nam);
2663 if Debug_Flag_E and not Report then
2664 Write_Str (" Overloaded call ");
2665 Write_Int (Int (N));
2666 Write_Str (" compatible with ");
2667 Write_Int (Int (Nam));
2670 end Indicate_Name_And_Type;
2672 ------------------------
2673 -- Operator_Hidden_By --
2674 ------------------------
2676 function Operator_Hidden_By (Fun : Entity_Id) return Boolean is
2677 Act1 : constant Node_Id := First_Actual (N);
2678 Act2 : constant Node_Id := Next_Actual (Act1);
2679 Form1 : constant Entity_Id := First_Formal (Fun);
2680 Form2 : constant Entity_Id := Next_Formal (Form1);
2683 if Ekind (Fun) /= E_Function
2684 or else Is_Abstract_Subprogram (Fun)
2688 elsif not Has_Compatible_Type (Act1, Etype (Form1)) then
2691 elsif Present (Form2) then
2693 No (Act2) or else not Has_Compatible_Type (Act2, Etype (Form2))
2698 elsif Present (Act2) then
2702 -- Now we know that the arity of the operator matches the function,
2703 -- and the function call is a valid interpretation. The function
2704 -- hides the operator if it has the right signature, or if one of
2705 -- its operands is a non-abstract operation on Address when this is
2706 -- a visible integer type.
2708 return Hides_Op (Fun, Nam)
2709 or else Is_Descendent_Of_Address (Etype (Form1))
2712 and then Is_Descendent_Of_Address (Etype (Form2)));
2713 end Operator_Hidden_By;
2715 -- Start of processing for Analyze_One_Call
2720 -- If the subprogram has no formals or if all the formals have defaults,
2721 -- and the return type is an array type, the node may denote an indexing
2722 -- of the result of a parameterless call. In Ada 2005, the subprogram
2723 -- may have one non-defaulted formal, and the call may have been written
2724 -- in prefix notation, so that the rebuilt parameter list has more than
2727 if not Is_Overloadable (Nam)
2728 and then Ekind (Nam) /= E_Subprogram_Type
2729 and then Ekind (Nam) /= E_Entry_Family
2734 -- An indexing requires at least one actual
2736 if not Is_Empty_List (Actuals)
2738 (Needs_No_Actuals (Nam)
2740 (Needs_One_Actual (Nam)
2741 and then Present (Next_Actual (First (Actuals)))))
2743 if Is_Array_Type (Subp_Type) then
2744 Is_Indexed := Try_Indexed_Call (N, Nam, Subp_Type, Must_Skip);
2746 elsif Is_Access_Type (Subp_Type)
2747 and then Is_Array_Type (Designated_Type (Subp_Type))
2751 (N, Nam, Designated_Type (Subp_Type), Must_Skip);
2753 -- The prefix can also be a parameterless function that returns an
2754 -- access to subprogram, in which case this is an indirect call.
2755 -- If this succeeds, an explicit dereference is added later on,
2756 -- in Analyze_Call or Resolve_Call.
2758 elsif Is_Access_Type (Subp_Type)
2759 and then Ekind (Designated_Type (Subp_Type)) = E_Subprogram_Type
2761 Is_Indirect := Try_Indirect_Call (N, Nam, Subp_Type);
2766 -- If the call has been transformed into a slice, it is of the form
2767 -- F (Subtype) where F is parameterless. The node has been rewritten in
2768 -- Try_Indexed_Call and there is nothing else to do.
2771 and then Nkind (N) = N_Slice
2777 (N, Nam, (Report and not Is_Indexed and not Is_Indirect), Norm_OK);
2781 -- If an indirect call is a possible interpretation, indicate
2782 -- success to the caller.
2788 -- Mismatch in number or names of parameters
2790 elsif Debug_Flag_E then
2791 Write_Str (" normalization fails in call ");
2792 Write_Int (Int (N));
2793 Write_Str (" with subprogram ");
2794 Write_Int (Int (Nam));
2798 -- If the context expects a function call, discard any interpretation
2799 -- that is a procedure. If the node is not overloaded, leave as is for
2800 -- better error reporting when type mismatch is found.
2802 elsif Nkind (N) = N_Function_Call
2803 and then Is_Overloaded (Name (N))
2804 and then Ekind (Nam) = E_Procedure
2808 -- Ditto for function calls in a procedure context
2810 elsif Nkind (N) = N_Procedure_Call_Statement
2811 and then Is_Overloaded (Name (N))
2812 and then Etype (Nam) /= Standard_Void_Type
2816 elsif No (Actuals) then
2818 -- If Normalize succeeds, then there are default parameters for
2821 Indicate_Name_And_Type;
2823 elsif Ekind (Nam) = E_Operator then
2824 if Nkind (N) = N_Procedure_Call_Statement then
2828 -- This can occur when the prefix of the call is an operator
2829 -- name or an expanded name whose selector is an operator name.
2831 Analyze_Operator_Call (N, Nam);
2833 if Etype (N) /= Prev_T then
2835 -- Check that operator is not hidden by a function interpretation
2837 if Is_Overloaded (Name (N)) then
2843 Get_First_Interp (Name (N), I, It);
2844 while Present (It.Nam) loop
2845 if Operator_Hidden_By (It.Nam) then
2846 Set_Etype (N, Prev_T);
2850 Get_Next_Interp (I, It);
2855 -- If operator matches formals, record its name on the call.
2856 -- If the operator is overloaded, Resolve will select the
2857 -- correct one from the list of interpretations. The call
2858 -- node itself carries the first candidate.
2860 Set_Entity (Name (N), Nam);
2863 elsif Report and then Etype (N) = Any_Type then
2864 Error_Msg_N ("incompatible arguments for operator", N);
2868 -- Normalize_Actuals has chained the named associations in the
2869 -- correct order of the formals.
2871 Actual := First_Actual (N);
2872 Formal := First_Formal (Nam);
2874 -- If we are analyzing a call rewritten from object notation, skip
2875 -- first actual, which may be rewritten later as an explicit
2879 Next_Actual (Actual);
2880 Next_Formal (Formal);
2883 while Present (Actual) and then Present (Formal) loop
2884 if Nkind (Parent (Actual)) /= N_Parameter_Association
2885 or else Chars (Selector_Name (Parent (Actual))) = Chars (Formal)
2887 -- The actual can be compatible with the formal, but we must
2888 -- also check that the context is not an address type that is
2889 -- visibly an integer type, as is the case in VMS_64. In this
2890 -- case the use of literals is illegal, except in the body of
2891 -- descendents of system, where arithmetic operations on
2892 -- address are of course used.
2894 if Has_Compatible_Type (Actual, Etype (Formal))
2896 (Etype (Actual) /= Universal_Integer
2897 or else not Is_Descendent_Of_Address (Etype (Formal))
2899 Is_Predefined_File_Name
2900 (Unit_File_Name (Get_Source_Unit (N))))
2902 Next_Actual (Actual);
2903 Next_Formal (Formal);
2906 if Debug_Flag_E then
2907 Write_Str (" type checking fails in call ");
2908 Write_Int (Int (N));
2909 Write_Str (" with formal ");
2910 Write_Int (Int (Formal));
2911 Write_Str (" in subprogram ");
2912 Write_Int (Int (Nam));
2916 if Report and not Is_Indexed and not Is_Indirect then
2918 -- Ada 2005 (AI-251): Complete the error notification
2919 -- to help new Ada 2005 users.
2921 if Is_Class_Wide_Type (Etype (Formal))
2922 and then Is_Interface (Etype (Etype (Formal)))
2923 and then not Interface_Present_In_Ancestor
2924 (Typ => Etype (Actual),
2925 Iface => Etype (Etype (Formal)))
2928 ("(Ada 2005) does not implement interface }",
2929 Actual, Etype (Etype (Formal)));
2932 Wrong_Type (Actual, Etype (Formal));
2934 if Nkind (Actual) = N_Op_Eq
2935 and then Nkind (Left_Opnd (Actual)) = N_Identifier
2937 Formal := First_Formal (Nam);
2938 while Present (Formal) loop
2939 if Chars (Left_Opnd (Actual)) = Chars (Formal) then
2940 Error_Msg_N -- CODEFIX
2941 ("possible misspelling of `='>`!", Actual);
2945 Next_Formal (Formal);
2949 if All_Errors_Mode then
2950 Error_Msg_Sloc := Sloc (Nam);
2952 if Etype (Formal) = Any_Type then
2954 ("there is no legal actual parameter", Actual);
2957 if Is_Overloadable (Nam)
2958 and then Present (Alias (Nam))
2959 and then not Comes_From_Source (Nam)
2962 ("\\ =='> in call to inherited operation & #!",
2965 elsif Ekind (Nam) = E_Subprogram_Type then
2967 Access_To_Subprogram_Typ :
2968 constant Entity_Id :=
2970 (Associated_Node_For_Itype (Nam));
2973 "\\ =='> in call to dereference of &#!",
2974 Actual, Access_To_Subprogram_Typ);
2979 ("\\ =='> in call to &#!", Actual, Nam);
2989 -- Normalize_Actuals has verified that a default value exists
2990 -- for this formal. Current actual names a subsequent formal.
2992 Next_Formal (Formal);
2996 -- On exit, all actuals match
2998 Indicate_Name_And_Type;
3000 end Analyze_One_Call;
3002 ---------------------------
3003 -- Analyze_Operator_Call --
3004 ---------------------------
3006 procedure Analyze_Operator_Call (N : Node_Id; Op_Id : Entity_Id) is
3007 Op_Name : constant Name_Id := Chars (Op_Id);
3008 Act1 : constant Node_Id := First_Actual (N);
3009 Act2 : constant Node_Id := Next_Actual (Act1);
3012 -- Binary operator case
3014 if Present (Act2) then
3016 -- If more than two operands, then not binary operator after all
3018 if Present (Next_Actual (Act2)) then
3021 elsif Op_Name = Name_Op_Add
3022 or else Op_Name = Name_Op_Subtract
3023 or else Op_Name = Name_Op_Multiply
3024 or else Op_Name = Name_Op_Divide
3025 or else Op_Name = Name_Op_Mod
3026 or else Op_Name = Name_Op_Rem
3027 or else Op_Name = Name_Op_Expon
3029 Find_Arithmetic_Types (Act1, Act2, Op_Id, N);
3031 elsif Op_Name = Name_Op_And
3032 or else Op_Name = Name_Op_Or
3033 or else Op_Name = Name_Op_Xor
3035 Find_Boolean_Types (Act1, Act2, Op_Id, N);
3037 elsif Op_Name = Name_Op_Lt
3038 or else Op_Name = Name_Op_Le
3039 or else Op_Name = Name_Op_Gt
3040 or else Op_Name = Name_Op_Ge
3042 Find_Comparison_Types (Act1, Act2, Op_Id, N);
3044 elsif Op_Name = Name_Op_Eq
3045 or else Op_Name = Name_Op_Ne
3047 Find_Equality_Types (Act1, Act2, Op_Id, N);
3049 elsif Op_Name = Name_Op_Concat then
3050 Find_Concatenation_Types (Act1, Act2, Op_Id, N);
3052 -- Is this else null correct, or should it be an abort???
3058 -- Unary operator case
3061 if Op_Name = Name_Op_Subtract or else
3062 Op_Name = Name_Op_Add or else
3063 Op_Name = Name_Op_Abs
3065 Find_Unary_Types (Act1, Op_Id, N);
3068 Op_Name = Name_Op_Not
3070 Find_Negation_Types (Act1, Op_Id, N);
3072 -- Is this else null correct, or should it be an abort???
3078 end Analyze_Operator_Call;
3080 -------------------------------------------
3081 -- Analyze_Overloaded_Selected_Component --
3082 -------------------------------------------
3084 procedure Analyze_Overloaded_Selected_Component (N : Node_Id) is
3085 Nam : constant Node_Id := Prefix (N);
3086 Sel : constant Node_Id := Selector_Name (N);
3093 Set_Etype (Sel, Any_Type);
3095 Get_First_Interp (Nam, I, It);
3096 while Present (It.Typ) loop
3097 if Is_Access_Type (It.Typ) then
3098 T := Designated_Type (It.Typ);
3099 Error_Msg_NW (Warn_On_Dereference, "?implicit dereference", N);
3104 -- Locate the component. For a private prefix the selector can denote
3107 if Is_Record_Type (T) or else Is_Private_Type (T) then
3109 -- If the prefix is a class-wide type, the visible components are
3110 -- those of the base type.
3112 if Is_Class_Wide_Type (T) then
3116 Comp := First_Entity (T);
3117 while Present (Comp) loop
3118 if Chars (Comp) = Chars (Sel)
3119 and then Is_Visible_Component (Comp)
3122 -- AI05-105: if the context is an object renaming with
3123 -- an anonymous access type, the expected type of the
3124 -- object must be anonymous. This is a name resolution rule.
3126 if Nkind (Parent (N)) /= N_Object_Renaming_Declaration
3127 or else No (Access_Definition (Parent (N)))
3128 or else Ekind (Etype (Comp)) = E_Anonymous_Access_Type
3130 Ekind (Etype (Comp)) = E_Anonymous_Access_Subprogram_Type
3132 Set_Entity (Sel, Comp);
3133 Set_Etype (Sel, Etype (Comp));
3134 Add_One_Interp (N, Etype (Comp), Etype (Comp));
3136 -- This also specifies a candidate to resolve the name.
3137 -- Further overloading will be resolved from context.
3138 -- The selector name itself does not carry overloading
3141 Set_Etype (Nam, It.Typ);
3144 -- Named access type in the context of a renaming
3145 -- declaration with an access definition. Remove
3146 -- inapplicable candidate.
3155 elsif Is_Concurrent_Type (T) then
3156 Comp := First_Entity (T);
3157 while Present (Comp)
3158 and then Comp /= First_Private_Entity (T)
3160 if Chars (Comp) = Chars (Sel) then
3161 if Is_Overloadable (Comp) then
3162 Add_One_Interp (Sel, Comp, Etype (Comp));
3164 Set_Entity_With_Style_Check (Sel, Comp);
3165 Generate_Reference (Comp, Sel);
3168 Set_Etype (Sel, Etype (Comp));
3169 Set_Etype (N, Etype (Comp));
3170 Set_Etype (Nam, It.Typ);
3172 -- For access type case, introduce explicit dereference for
3173 -- more uniform treatment of entry calls. Do this only once
3174 -- if several interpretations yield an access type.
3176 if Is_Access_Type (Etype (Nam))
3177 and then Nkind (Nam) /= N_Explicit_Dereference
3179 Insert_Explicit_Dereference (Nam);
3181 (Warn_On_Dereference, "?implicit dereference", N);
3188 Set_Is_Overloaded (N, Is_Overloaded (Sel));
3191 Get_Next_Interp (I, It);
3194 if Etype (N) = Any_Type
3195 and then not Try_Object_Operation (N)
3197 Error_Msg_NE ("undefined selector& for overloaded prefix", N, Sel);
3198 Set_Entity (Sel, Any_Id);
3199 Set_Etype (Sel, Any_Type);
3201 end Analyze_Overloaded_Selected_Component;
3203 ----------------------------------
3204 -- Analyze_Qualified_Expression --
3205 ----------------------------------
3207 procedure Analyze_Qualified_Expression (N : Node_Id) is
3208 Mark : constant Entity_Id := Subtype_Mark (N);
3209 Expr : constant Node_Id := Expression (N);
3215 Analyze_Expression (Expr);
3217 Set_Etype (N, Any_Type);
3222 if T = Any_Type then
3226 Check_Fully_Declared (T, N);
3228 -- If expected type is class-wide, check for exact match before
3229 -- expansion, because if the expression is a dispatching call it
3230 -- may be rewritten as explicit dereference with class-wide result.
3231 -- If expression is overloaded, retain only interpretations that
3232 -- will yield exact matches.
3234 if Is_Class_Wide_Type (T) then
3235 if not Is_Overloaded (Expr) then
3236 if Base_Type (Etype (Expr)) /= Base_Type (T) then
3237 if Nkind (Expr) = N_Aggregate then
3238 Error_Msg_N ("type of aggregate cannot be class-wide", Expr);
3240 Wrong_Type (Expr, T);
3245 Get_First_Interp (Expr, I, It);
3247 while Present (It.Nam) loop
3248 if Base_Type (It.Typ) /= Base_Type (T) then
3252 Get_Next_Interp (I, It);
3258 end Analyze_Qualified_Expression;
3260 -----------------------------------
3261 -- Analyze_Quantified_Expression --
3262 -----------------------------------
3264 procedure Analyze_Quantified_Expression (N : Node_Id) is
3265 Loc : constant Source_Ptr := Sloc (N);
3266 Ent : constant Entity_Id :=
3268 (E_Loop, Current_Scope, Sloc (N), 'L');
3273 Check_SPARK_Restriction ("quantified expression is not allowed", N);
3275 Set_Etype (Ent, Standard_Void_Type);
3276 Set_Parent (Ent, N);
3278 if Present (Loop_Parameter_Specification (N)) then
3280 Make_Iteration_Scheme (Loc,
3281 Loop_Parameter_Specification =>
3282 Loop_Parameter_Specification (N));
3285 Make_Iteration_Scheme (Loc,
3286 Iterator_Specification =>
3287 Iterator_Specification (N));
3291 Set_Parent (Iterator, N);
3292 Analyze_Iteration_Scheme (Iterator);
3294 -- The loop specification may have been converted into an
3295 -- iterator specification during its analysis. Update the
3296 -- quantified node accordingly.
3298 if Present (Iterator_Specification (Iterator)) then
3299 Set_Iterator_Specification
3300 (N, Iterator_Specification (Iterator));
3301 Set_Loop_Parameter_Specification (N, Empty);
3304 Analyze (Condition (N));
3307 Set_Etype (N, Standard_Boolean);
3308 end Analyze_Quantified_Expression;
3314 procedure Analyze_Range (N : Node_Id) is
3315 L : constant Node_Id := Low_Bound (N);
3316 H : constant Node_Id := High_Bound (N);
3317 I1, I2 : Interp_Index;
3320 procedure Check_Common_Type (T1, T2 : Entity_Id);
3321 -- Verify the compatibility of two types, and choose the
3322 -- non universal one if the other is universal.
3324 procedure Check_High_Bound (T : Entity_Id);
3325 -- Test one interpretation of the low bound against all those
3326 -- of the high bound.
3328 procedure Check_Universal_Expression (N : Node_Id);
3329 -- In Ada83, reject bounds of a universal range that are not
3330 -- literals or entity names.
3332 -----------------------
3333 -- Check_Common_Type --
3334 -----------------------
3336 procedure Check_Common_Type (T1, T2 : Entity_Id) is
3338 if Covers (T1 => T1, T2 => T2)
3340 Covers (T1 => T2, T2 => T1)
3342 if T1 = Universal_Integer
3343 or else T1 = Universal_Real
3344 or else T1 = Any_Character
3346 Add_One_Interp (N, Base_Type (T2), Base_Type (T2));
3349 Add_One_Interp (N, T1, T1);
3352 Add_One_Interp (N, Base_Type (T1), Base_Type (T1));
3355 end Check_Common_Type;
3357 ----------------------
3358 -- Check_High_Bound --
3359 ----------------------
3361 procedure Check_High_Bound (T : Entity_Id) is
3363 if not Is_Overloaded (H) then
3364 Check_Common_Type (T, Etype (H));
3366 Get_First_Interp (H, I2, It2);
3367 while Present (It2.Typ) loop
3368 Check_Common_Type (T, It2.Typ);
3369 Get_Next_Interp (I2, It2);
3372 end Check_High_Bound;
3374 -----------------------------
3375 -- Is_Universal_Expression --
3376 -----------------------------
3378 procedure Check_Universal_Expression (N : Node_Id) is
3380 if Etype (N) = Universal_Integer
3381 and then Nkind (N) /= N_Integer_Literal
3382 and then not Is_Entity_Name (N)
3383 and then Nkind (N) /= N_Attribute_Reference
3385 Error_Msg_N ("illegal bound in discrete range", N);
3387 end Check_Universal_Expression;
3389 -- Start of processing for Analyze_Range
3392 Set_Etype (N, Any_Type);
3393 Analyze_Expression (L);
3394 Analyze_Expression (H);
3396 if Etype (L) = Any_Type or else Etype (H) = Any_Type then
3400 if not Is_Overloaded (L) then
3401 Check_High_Bound (Etype (L));
3403 Get_First_Interp (L, I1, It1);
3404 while Present (It1.Typ) loop
3405 Check_High_Bound (It1.Typ);
3406 Get_Next_Interp (I1, It1);
3410 -- If result is Any_Type, then we did not find a compatible pair
3412 if Etype (N) = Any_Type then
3413 Error_Msg_N ("incompatible types in range ", N);
3417 if Ada_Version = Ada_83
3419 (Nkind (Parent (N)) = N_Loop_Parameter_Specification
3420 or else Nkind (Parent (N)) = N_Constrained_Array_Definition)
3422 Check_Universal_Expression (L);
3423 Check_Universal_Expression (H);
3427 -----------------------
3428 -- Analyze_Reference --
3429 -----------------------
3431 procedure Analyze_Reference (N : Node_Id) is
3432 P : constant Node_Id := Prefix (N);
3435 Acc_Type : Entity_Id;
3440 -- An interesting error check, if we take the 'Reference of an object
3441 -- for which a pragma Atomic or Volatile has been given, and the type
3442 -- of the object is not Atomic or Volatile, then we are in trouble. The
3443 -- problem is that no trace of the atomic/volatile status will remain
3444 -- for the backend to respect when it deals with the resulting pointer,
3445 -- since the pointer type will not be marked atomic (it is a pointer to
3446 -- the base type of the object).
3448 -- It is not clear if that can ever occur, but in case it does, we will
3449 -- generate an error message. Not clear if this message can ever be
3450 -- generated, and pretty clear that it represents a bug if it is, still
3451 -- seems worth checking, except in CodePeer mode where we do not really
3452 -- care and don't want to bother the user.
3456 if Is_Entity_Name (P)
3457 and then Is_Object_Reference (P)
3458 and then not CodePeer_Mode
3463 if (Has_Atomic_Components (E)
3464 and then not Has_Atomic_Components (T))
3466 (Has_Volatile_Components (E)
3467 and then not Has_Volatile_Components (T))
3468 or else (Is_Atomic (E) and then not Is_Atomic (T))
3469 or else (Is_Volatile (E) and then not Is_Volatile (T))
3471 Error_Msg_N ("cannot take reference to Atomic/Volatile object", N);
3475 -- Carry on with normal processing
3477 Acc_Type := Create_Itype (E_Allocator_Type, N);
3478 Set_Etype (Acc_Type, Acc_Type);
3479 Set_Directly_Designated_Type (Acc_Type, Etype (P));
3480 Set_Etype (N, Acc_Type);
3481 end Analyze_Reference;
3483 --------------------------------
3484 -- Analyze_Selected_Component --
3485 --------------------------------
3487 -- Prefix is a record type or a task or protected type. In the latter case,
3488 -- the selector must denote a visible entry.
3490 procedure Analyze_Selected_Component (N : Node_Id) is
3491 Name : constant Node_Id := Prefix (N);
3492 Sel : constant Node_Id := Selector_Name (N);
3495 Has_Candidate : Boolean := False;
3498 Pent : Entity_Id := Empty;
3499 Prefix_Type : Entity_Id;
3501 Type_To_Use : Entity_Id;
3502 -- In most cases this is the Prefix_Type, but if the Prefix_Type is
3503 -- a class-wide type, we use its root type, whose components are
3504 -- present in the class-wide type.
3506 Is_Single_Concurrent_Object : Boolean;
3507 -- Set True if the prefix is a single task or a single protected object
3509 procedure Find_Component_In_Instance (Rec : Entity_Id);
3510 -- In an instance, a component of a private extension may not be visible
3511 -- while it was visible in the generic. Search candidate scope for a
3512 -- component with the proper identifier. This is only done if all other
3513 -- searches have failed. When the match is found (it always will be),
3514 -- the Etype of both N and Sel are set from this component, and the
3515 -- entity of Sel is set to reference this component.
3517 function Has_Mode_Conformant_Spec (Comp : Entity_Id) return Boolean;
3518 -- It is known that the parent of N denotes a subprogram call. Comp
3519 -- is an overloadable component of the concurrent type of the prefix.
3520 -- Determine whether all formals of the parent of N and Comp are mode
3521 -- conformant. If the parent node is not analyzed yet it may be an
3522 -- indexed component rather than a function call.
3524 --------------------------------
3525 -- Find_Component_In_Instance --
3526 --------------------------------
3528 procedure Find_Component_In_Instance (Rec : Entity_Id) is
3532 Comp := First_Component (Rec);
3533 while Present (Comp) loop
3534 if Chars (Comp) = Chars (Sel) then
3535 Set_Entity_With_Style_Check (Sel, Comp);
3536 Set_Etype (Sel, Etype (Comp));
3537 Set_Etype (N, Etype (Comp));
3541 Next_Component (Comp);
3544 -- This must succeed because code was legal in the generic
3546 raise Program_Error;
3547 end Find_Component_In_Instance;
3549 ------------------------------
3550 -- Has_Mode_Conformant_Spec --
3551 ------------------------------
3553 function Has_Mode_Conformant_Spec (Comp : Entity_Id) return Boolean is
3554 Comp_Param : Entity_Id;
3556 Param_Typ : Entity_Id;
3559 Comp_Param := First_Formal (Comp);
3561 if Nkind (Parent (N)) = N_Indexed_Component then
3562 Param := First (Expressions (Parent (N)));
3564 Param := First (Parameter_Associations (Parent (N)));
3567 while Present (Comp_Param)
3568 and then Present (Param)
3570 Param_Typ := Find_Parameter_Type (Param);
3572 if Present (Param_Typ)
3574 not Conforming_Types
3575 (Etype (Comp_Param), Param_Typ, Mode_Conformant)
3580 Next_Formal (Comp_Param);
3584 -- One of the specs has additional formals
3586 if Present (Comp_Param) or else Present (Param) then
3591 end Has_Mode_Conformant_Spec;
3593 -- Start of processing for Analyze_Selected_Component
3596 Set_Etype (N, Any_Type);
3598 if Is_Overloaded (Name) then
3599 Analyze_Overloaded_Selected_Component (N);
3602 elsif Etype (Name) = Any_Type then
3603 Set_Entity (Sel, Any_Id);
3604 Set_Etype (Sel, Any_Type);
3608 Prefix_Type := Etype (Name);
3611 if Is_Access_Type (Prefix_Type) then
3613 -- A RACW object can never be used as prefix of a selected component
3614 -- since that means it is dereferenced without being a controlling
3615 -- operand of a dispatching operation (RM E.2.2(16/1)). Before
3616 -- reporting an error, we must check whether this is actually a
3617 -- dispatching call in prefix form.
3619 if Is_Remote_Access_To_Class_Wide_Type (Prefix_Type)
3620 and then Comes_From_Source (N)
3622 if Try_Object_Operation (N) then
3626 ("invalid dereference of a remote access-to-class-wide value",
3630 -- Normal case of selected component applied to access type
3633 Error_Msg_NW (Warn_On_Dereference, "?implicit dereference", N);
3635 if Is_Entity_Name (Name) then
3636 Pent := Entity (Name);
3637 elsif Nkind (Name) = N_Selected_Component
3638 and then Is_Entity_Name (Selector_Name (Name))
3640 Pent := Entity (Selector_Name (Name));
3643 Prefix_Type := Process_Implicit_Dereference_Prefix (Pent, Name);
3646 -- If we have an explicit dereference of a remote access-to-class-wide
3647 -- value, then issue an error (see RM-E.2.2(16/1)). However we first
3648 -- have to check for the case of a prefix that is a controlling operand
3649 -- of a prefixed dispatching call, as the dereference is legal in that
3650 -- case. Normally this condition is checked in Validate_Remote_Access_
3651 -- To_Class_Wide_Type, but we have to defer the checking for selected
3652 -- component prefixes because of the prefixed dispatching call case.
3653 -- Note that implicit dereferences are checked for this just above.
3655 elsif Nkind (Name) = N_Explicit_Dereference
3656 and then Is_Remote_Access_To_Class_Wide_Type (Etype (Prefix (Name)))
3657 and then Comes_From_Source (N)
3659 if Try_Object_Operation (N) then
3663 ("invalid dereference of a remote access-to-class-wide value",
3668 -- (Ada 2005): if the prefix is the limited view of a type, and
3669 -- the context already includes the full view, use the full view
3670 -- in what follows, either to retrieve a component of to find
3671 -- a primitive operation. If the prefix is an explicit dereference,
3672 -- set the type of the prefix to reflect this transformation.
3673 -- If the non-limited view is itself an incomplete type, get the
3674 -- full view if available.
3676 if Is_Incomplete_Type (Prefix_Type)
3677 and then From_With_Type (Prefix_Type)
3678 and then Present (Non_Limited_View (Prefix_Type))
3680 Prefix_Type := Get_Full_View (Non_Limited_View (Prefix_Type));
3682 if Nkind (N) = N_Explicit_Dereference then
3683 Set_Etype (Prefix (N), Prefix_Type);
3686 elsif Ekind (Prefix_Type) = E_Class_Wide_Type
3687 and then From_With_Type (Prefix_Type)
3688 and then Present (Non_Limited_View (Etype (Prefix_Type)))
3691 Class_Wide_Type (Non_Limited_View (Etype (Prefix_Type)));
3693 if Nkind (N) = N_Explicit_Dereference then
3694 Set_Etype (Prefix (N), Prefix_Type);
3698 if Ekind (Prefix_Type) = E_Private_Subtype then
3699 Prefix_Type := Base_Type (Prefix_Type);
3702 Type_To_Use := Prefix_Type;
3704 -- For class-wide types, use the entity list of the root type. This
3705 -- indirection is specially important for private extensions because
3706 -- only the root type get switched (not the class-wide type).
3708 if Is_Class_Wide_Type (Prefix_Type) then
3709 Type_To_Use := Root_Type (Prefix_Type);
3712 -- If the prefix is a single concurrent object, use its name in error
3713 -- messages, rather than that of its anonymous type.
3715 Is_Single_Concurrent_Object :=
3716 Is_Concurrent_Type (Prefix_Type)
3717 and then Is_Internal_Name (Chars (Prefix_Type))
3718 and then not Is_Derived_Type (Prefix_Type)
3719 and then Is_Entity_Name (Name);
3721 Comp := First_Entity (Type_To_Use);
3723 -- If the selector has an original discriminant, the node appears in
3724 -- an instance. Replace the discriminant with the corresponding one
3725 -- in the current discriminated type. For nested generics, this must
3726 -- be done transitively, so note the new original discriminant.
3728 if Nkind (Sel) = N_Identifier
3729 and then In_Instance
3730 and then Present (Original_Discriminant (Sel))
3732 Comp := Find_Corresponding_Discriminant (Sel, Prefix_Type);
3734 -- Mark entity before rewriting, for completeness and because
3735 -- subsequent semantic checks might examine the original node.
3737 Set_Entity (Sel, Comp);
3738 Rewrite (Selector_Name (N),
3739 New_Occurrence_Of (Comp, Sloc (N)));
3740 Set_Original_Discriminant (Selector_Name (N), Comp);
3741 Set_Etype (N, Etype (Comp));
3743 if Is_Access_Type (Etype (Name)) then
3744 Insert_Explicit_Dereference (Name);
3745 Error_Msg_NW (Warn_On_Dereference, "?implicit dereference", N);
3748 elsif Is_Record_Type (Prefix_Type) then
3750 -- Find component with given name
3752 while Present (Comp) loop
3753 if Chars (Comp) = Chars (Sel)
3754 and then Is_Visible_Component (Comp)
3756 Set_Entity_With_Style_Check (Sel, Comp);
3757 Set_Etype (Sel, Etype (Comp));
3759 if Ekind (Comp) = E_Discriminant then
3760 if Is_Unchecked_Union (Base_Type (Prefix_Type)) then
3762 ("cannot reference discriminant of Unchecked_Union",
3766 if Is_Generic_Type (Prefix_Type)
3768 Is_Generic_Type (Root_Type (Prefix_Type))
3770 Set_Original_Discriminant (Sel, Comp);
3774 -- Resolve the prefix early otherwise it is not possible to
3775 -- build the actual subtype of the component: it may need
3776 -- to duplicate this prefix and duplication is only allowed
3777 -- on fully resolved expressions.
3781 -- Ada 2005 (AI-50217): Check wrong use of incomplete types or
3782 -- subtypes in a package specification.
3785 -- limited with Pkg;
3787 -- type Acc_Inc is access Pkg.T;
3789 -- N : Natural := X.all.Comp; -- ERROR, limited view
3790 -- end Pkg; -- Comp is not visible
3792 if Nkind (Name) = N_Explicit_Dereference
3793 and then From_With_Type (Etype (Prefix (Name)))
3794 and then not Is_Potentially_Use_Visible (Etype (Name))
3795 and then Nkind (Parent (Cunit_Entity (Current_Sem_Unit))) =
3796 N_Package_Specification
3799 ("premature usage of incomplete}", Prefix (Name),
3800 Etype (Prefix (Name)));
3803 -- We never need an actual subtype for the case of a selection
3804 -- for a indexed component of a non-packed array, since in
3805 -- this case gigi generates all the checks and can find the
3806 -- necessary bounds information.
3808 -- We also do not need an actual subtype for the case of a
3809 -- first, last, length, or range attribute applied to a
3810 -- non-packed array, since gigi can again get the bounds in
3811 -- these cases (gigi cannot handle the packed case, since it
3812 -- has the bounds of the packed array type, not the original
3813 -- bounds of the type). However, if the prefix is itself a
3814 -- selected component, as in a.b.c (i), gigi may regard a.b.c
3815 -- as a dynamic-sized temporary, so we do generate an actual
3816 -- subtype for this case.
3818 Parent_N := Parent (N);
3820 if not Is_Packed (Etype (Comp))
3822 ((Nkind (Parent_N) = N_Indexed_Component
3823 and then Nkind (Name) /= N_Selected_Component)
3825 (Nkind (Parent_N) = N_Attribute_Reference
3826 and then (Attribute_Name (Parent_N) = Name_First
3828 Attribute_Name (Parent_N) = Name_Last
3830 Attribute_Name (Parent_N) = Name_Length
3832 Attribute_Name (Parent_N) = Name_Range)))
3834 Set_Etype (N, Etype (Comp));
3836 -- If full analysis is not enabled, we do not generate an
3837 -- actual subtype, because in the absence of expansion
3838 -- reference to a formal of a protected type, for example,
3839 -- will not be properly transformed, and will lead to
3840 -- out-of-scope references in gigi.
3842 -- In all other cases, we currently build an actual subtype.
3843 -- It seems likely that many of these cases can be avoided,
3844 -- but right now, the front end makes direct references to the
3845 -- bounds (e.g. in generating a length check), and if we do
3846 -- not make an actual subtype, we end up getting a direct
3847 -- reference to a discriminant, which will not do.
3849 elsif Full_Analysis then
3851 Build_Actual_Subtype_Of_Component (Etype (Comp), N);
3852 Insert_Action (N, Act_Decl);
3854 if No (Act_Decl) then
3855 Set_Etype (N, Etype (Comp));
3858 -- Component type depends on discriminants. Enter the
3859 -- main attributes of the subtype.
3862 Subt : constant Entity_Id :=
3863 Defining_Identifier (Act_Decl);
3866 Set_Etype (Subt, Base_Type (Etype (Comp)));
3867 Set_Ekind (Subt, Ekind (Etype (Comp)));
3868 Set_Etype (N, Subt);
3872 -- If Full_Analysis not enabled, just set the Etype
3875 Set_Etype (N, Etype (Comp));
3881 -- If the prefix is a private extension, check only the visible
3882 -- components of the partial view. This must include the tag,
3883 -- which can appear in expanded code in a tag check.
3885 if Ekind (Type_To_Use) = E_Record_Type_With_Private
3886 and then Chars (Selector_Name (N)) /= Name_uTag
3888 exit when Comp = Last_Entity (Type_To_Use);
3894 -- Ada 2005 (AI-252): The selected component can be interpreted as
3895 -- a prefixed view of a subprogram. Depending on the context, this is
3896 -- either a name that can appear in a renaming declaration, or part
3897 -- of an enclosing call given in prefix form.
3899 -- Ada 2005 (AI05-0030): In the case of dispatching requeue, the
3900 -- selected component should resolve to a name.
3902 if Ada_Version >= Ada_2005
3903 and then Is_Tagged_Type (Prefix_Type)
3904 and then not Is_Concurrent_Type (Prefix_Type)
3906 if Nkind (Parent (N)) = N_Generic_Association
3907 or else Nkind (Parent (N)) = N_Requeue_Statement
3908 or else Nkind (Parent (N)) = N_Subprogram_Renaming_Declaration
3910 if Find_Primitive_Operation (N) then
3914 elsif Try_Object_Operation (N) then
3918 -- If the transformation fails, it will be necessary to redo the
3919 -- analysis with all errors enabled, to indicate candidate
3920 -- interpretations and reasons for each failure ???
3924 elsif Is_Private_Type (Prefix_Type) then
3926 -- Allow access only to discriminants of the type. If the type has
3927 -- no full view, gigi uses the parent type for the components, so we
3928 -- do the same here.
3930 if No (Full_View (Prefix_Type)) then
3931 Type_To_Use := Root_Type (Base_Type (Prefix_Type));
3932 Comp := First_Entity (Type_To_Use);
3935 while Present (Comp) loop
3936 if Chars (Comp) = Chars (Sel) then
3937 if Ekind (Comp) = E_Discriminant then
3938 Set_Entity_With_Style_Check (Sel, Comp);
3939 Generate_Reference (Comp, Sel);
3941 Set_Etype (Sel, Etype (Comp));
3942 Set_Etype (N, Etype (Comp));
3944 if Is_Generic_Type (Prefix_Type)
3945 or else Is_Generic_Type (Root_Type (Prefix_Type))
3947 Set_Original_Discriminant (Sel, Comp);
3950 -- Before declaring an error, check whether this is tagged
3951 -- private type and a call to a primitive operation.
3953 elsif Ada_Version >= Ada_2005
3954 and then Is_Tagged_Type (Prefix_Type)
3955 and then Try_Object_Operation (N)
3960 Error_Msg_Node_2 := First_Subtype (Prefix_Type);
3961 Error_Msg_NE ("invisible selector& for }", N, Sel);
3962 Set_Entity (Sel, Any_Id);
3963 Set_Etype (N, Any_Type);
3972 elsif Is_Concurrent_Type (Prefix_Type) then
3974 -- Find visible operation with given name. For a protected type,
3975 -- the possible candidates are discriminants, entries or protected
3976 -- procedures. For a task type, the set can only include entries or
3977 -- discriminants if the task type is not an enclosing scope. If it
3978 -- is an enclosing scope (e.g. in an inner task) then all entities
3979 -- are visible, but the prefix must denote the enclosing scope, i.e.
3980 -- can only be a direct name or an expanded name.
3982 Set_Etype (Sel, Any_Type);
3983 In_Scope := In_Open_Scopes (Prefix_Type);
3985 while Present (Comp) loop
3986 if Chars (Comp) = Chars (Sel) then
3987 if Is_Overloadable (Comp) then
3988 Add_One_Interp (Sel, Comp, Etype (Comp));
3990 -- If the prefix is tagged, the correct interpretation may
3991 -- lie in the primitive or class-wide operations of the
3992 -- type. Perform a simple conformance check to determine
3993 -- whether Try_Object_Operation should be invoked even if
3994 -- a visible entity is found.
3996 if Is_Tagged_Type (Prefix_Type)
3998 Nkind_In (Parent (N), N_Procedure_Call_Statement,
4000 N_Indexed_Component)
4001 and then Has_Mode_Conformant_Spec (Comp)
4003 Has_Candidate := True;
4006 -- Note: a selected component may not denote a component of a
4007 -- protected type (4.1.3(7)).
4009 elsif Ekind_In (Comp, E_Discriminant, E_Entry_Family)
4011 and then not Is_Protected_Type (Prefix_Type)
4012 and then Is_Entity_Name (Name))
4014 Set_Entity_With_Style_Check (Sel, Comp);
4015 Generate_Reference (Comp, Sel);
4021 Set_Etype (Sel, Etype (Comp));
4022 Set_Etype (N, Etype (Comp));
4024 if Ekind (Comp) = E_Discriminant then
4025 Set_Original_Discriminant (Sel, Comp);
4028 -- For access type case, introduce explicit dereference for
4029 -- more uniform treatment of entry calls.
4031 if Is_Access_Type (Etype (Name)) then
4032 Insert_Explicit_Dereference (Name);
4034 (Warn_On_Dereference, "?implicit dereference", N);
4040 exit when not In_Scope
4042 Comp = First_Private_Entity (Base_Type (Prefix_Type));
4045 -- If there is no visible entity with the given name or none of the
4046 -- visible entities are plausible interpretations, check whether
4047 -- there is some other primitive operation with that name.
4049 if Ada_Version >= Ada_2005
4050 and then Is_Tagged_Type (Prefix_Type)
4052 if (Etype (N) = Any_Type
4053 or else not Has_Candidate)
4054 and then Try_Object_Operation (N)
4058 -- If the context is not syntactically a procedure call, it
4059 -- may be a call to a primitive function declared outside of
4060 -- the synchronized type.
4062 -- If the context is a procedure call, there might still be
4063 -- an overloading between an entry and a primitive procedure
4064 -- declared outside of the synchronized type, called in prefix
4065 -- notation. This is harder to disambiguate because in one case
4066 -- the controlling formal is implicit ???
4068 elsif Nkind (Parent (N)) /= N_Procedure_Call_Statement
4069 and then Nkind (Parent (N)) /= N_Indexed_Component
4070 and then Try_Object_Operation (N)
4076 if Etype (N) = Any_Type and then Is_Protected_Type (Prefix_Type) then
4077 -- Case of a prefix of a protected type: selector might denote
4078 -- an invisible private component.
4080 Comp := First_Private_Entity (Base_Type (Prefix_Type));
4081 while Present (Comp) and then Chars (Comp) /= Chars (Sel) loop
4085 if Present (Comp) then
4086 if Is_Single_Concurrent_Object then
4087 Error_Msg_Node_2 := Entity (Name);
4088 Error_Msg_NE ("invisible selector& for &", N, Sel);
4091 Error_Msg_Node_2 := First_Subtype (Prefix_Type);
4092 Error_Msg_NE ("invisible selector& for }", N, Sel);
4098 Set_Is_Overloaded (N, Is_Overloaded (Sel));
4103 Error_Msg_NE ("invalid prefix in selected component&", N, Sel);
4106 -- If N still has no type, the component is not defined in the prefix
4108 if Etype (N) = Any_Type then
4110 if Is_Single_Concurrent_Object then
4111 Error_Msg_Node_2 := Entity (Name);
4112 Error_Msg_NE ("no selector& for&", N, Sel);
4114 Check_Misspelled_Selector (Type_To_Use, Sel);
4116 elsif Is_Generic_Type (Prefix_Type)
4117 and then Ekind (Prefix_Type) = E_Record_Type_With_Private
4118 and then Prefix_Type /= Etype (Prefix_Type)
4119 and then Is_Record_Type (Etype (Prefix_Type))
4121 -- If this is a derived formal type, the parent may have
4122 -- different visibility at this point. Try for an inherited
4123 -- component before reporting an error.
4125 Set_Etype (Prefix (N), Etype (Prefix_Type));
4126 Analyze_Selected_Component (N);
4129 -- Similarly, if this is the actual for a formal derived type, the
4130 -- component inherited from the generic parent may not be visible
4131 -- in the actual, but the selected component is legal.
4133 elsif Ekind (Prefix_Type) = E_Record_Subtype_With_Private
4134 and then Is_Generic_Actual_Type (Prefix_Type)
4135 and then Present (Full_View (Prefix_Type))
4138 Find_Component_In_Instance
4139 (Generic_Parent_Type (Parent (Prefix_Type)));
4142 -- Finally, the formal and the actual may be private extensions,
4143 -- but the generic is declared in a child unit of the parent, and
4144 -- an additional step is needed to retrieve the proper scope.
4147 and then Present (Parent_Subtype (Etype (Base_Type (Prefix_Type))))
4149 Find_Component_In_Instance
4150 (Parent_Subtype (Etype (Base_Type (Prefix_Type))));
4153 -- Component not found, specialize error message when appropriate
4156 if Ekind (Prefix_Type) = E_Record_Subtype then
4158 -- Check whether this is a component of the base type which
4159 -- is absent from a statically constrained subtype. This will
4160 -- raise constraint error at run time, but is not a compile-
4161 -- time error. When the selector is illegal for base type as
4162 -- well fall through and generate a compilation error anyway.
4164 Comp := First_Component (Base_Type (Prefix_Type));
4165 while Present (Comp) loop
4166 if Chars (Comp) = Chars (Sel)
4167 and then Is_Visible_Component (Comp)
4169 Set_Entity_With_Style_Check (Sel, Comp);
4170 Generate_Reference (Comp, Sel);
4171 Set_Etype (Sel, Etype (Comp));
4172 Set_Etype (N, Etype (Comp));
4174 -- Emit appropriate message. Gigi will replace the
4175 -- node subsequently with the appropriate Raise.
4177 Apply_Compile_Time_Constraint_Error
4178 (N, "component not present in }?",
4179 CE_Discriminant_Check_Failed,
4180 Ent => Prefix_Type, Rep => False);
4181 Set_Raises_Constraint_Error (N);
4185 Next_Component (Comp);
4190 Error_Msg_Node_2 := First_Subtype (Prefix_Type);
4191 Error_Msg_NE ("no selector& for}", N, Sel);
4193 Check_Misspelled_Selector (Type_To_Use, Sel);
4196 Set_Entity (Sel, Any_Id);
4197 Set_Etype (Sel, Any_Type);
4199 end Analyze_Selected_Component;
4201 ---------------------------
4202 -- Analyze_Short_Circuit --
4203 ---------------------------
4205 procedure Analyze_Short_Circuit (N : Node_Id) is
4206 L : constant Node_Id := Left_Opnd (N);
4207 R : constant Node_Id := Right_Opnd (N);
4212 Analyze_Expression (L);
4213 Analyze_Expression (R);
4214 Set_Etype (N, Any_Type);
4216 if not Is_Overloaded (L) then
4217 if Root_Type (Etype (L)) = Standard_Boolean
4218 and then Has_Compatible_Type (R, Etype (L))
4220 Add_One_Interp (N, Etype (L), Etype (L));
4224 Get_First_Interp (L, Ind, It);
4225 while Present (It.Typ) loop
4226 if Root_Type (It.Typ) = Standard_Boolean
4227 and then Has_Compatible_Type (R, It.Typ)
4229 Add_One_Interp (N, It.Typ, It.Typ);
4232 Get_Next_Interp (Ind, It);
4236 -- Here we have failed to find an interpretation. Clearly we know that
4237 -- it is not the case that both operands can have an interpretation of
4238 -- Boolean, but this is by far the most likely intended interpretation.
4239 -- So we simply resolve both operands as Booleans, and at least one of
4240 -- these resolutions will generate an error message, and we do not need
4241 -- to give another error message on the short circuit operation itself.
4243 if Etype (N) = Any_Type then
4244 Resolve (L, Standard_Boolean);
4245 Resolve (R, Standard_Boolean);
4246 Set_Etype (N, Standard_Boolean);
4248 end Analyze_Short_Circuit;
4254 procedure Analyze_Slice (N : Node_Id) is
4255 P : constant Node_Id := Prefix (N);
4256 D : constant Node_Id := Discrete_Range (N);
4257 Array_Type : Entity_Id;
4259 procedure Analyze_Overloaded_Slice;
4260 -- If the prefix is overloaded, select those interpretations that
4261 -- yield a one-dimensional array type.
4263 ------------------------------
4264 -- Analyze_Overloaded_Slice --
4265 ------------------------------
4267 procedure Analyze_Overloaded_Slice is
4273 Set_Etype (N, Any_Type);
4275 Get_First_Interp (P, I, It);
4276 while Present (It.Nam) loop
4279 if Is_Access_Type (Typ) then
4280 Typ := Designated_Type (Typ);
4281 Error_Msg_NW (Warn_On_Dereference, "?implicit dereference", N);
4284 if Is_Array_Type (Typ)
4285 and then Number_Dimensions (Typ) = 1
4286 and then Has_Compatible_Type (D, Etype (First_Index (Typ)))
4288 Add_One_Interp (N, Typ, Typ);
4291 Get_Next_Interp (I, It);
4294 if Etype (N) = Any_Type then
4295 Error_Msg_N ("expect array type in prefix of slice", N);
4297 end Analyze_Overloaded_Slice;
4299 -- Start of processing for Analyze_Slice
4302 Check_SPARK_Restriction ("slice is not allowed", N);
4307 if Is_Overloaded (P) then
4308 Analyze_Overloaded_Slice;
4311 Array_Type := Etype (P);
4312 Set_Etype (N, Any_Type);
4314 if Is_Access_Type (Array_Type) then
4315 Array_Type := Designated_Type (Array_Type);
4316 Error_Msg_NW (Warn_On_Dereference, "?implicit dereference", N);
4319 if not Is_Array_Type (Array_Type) then
4320 Wrong_Type (P, Any_Array);
4322 elsif Number_Dimensions (Array_Type) > 1 then
4324 ("type is not one-dimensional array in slice prefix", N);
4327 Has_Compatible_Type (D, Etype (First_Index (Array_Type)))
4329 Wrong_Type (D, Etype (First_Index (Array_Type)));
4332 Set_Etype (N, Array_Type);
4337 -----------------------------
4338 -- Analyze_Type_Conversion --
4339 -----------------------------
4341 procedure Analyze_Type_Conversion (N : Node_Id) is
4342 Expr : constant Node_Id := Expression (N);
4346 -- If Conversion_OK is set, then the Etype is already set, and the
4347 -- only processing required is to analyze the expression. This is
4348 -- used to construct certain "illegal" conversions which are not
4349 -- allowed by Ada semantics, but can be handled OK by Gigi, see
4350 -- Sinfo for further details.
4352 if Conversion_OK (N) then
4357 -- Otherwise full type analysis is required, as well as some semantic
4358 -- checks to make sure the argument of the conversion is appropriate.
4360 Find_Type (Subtype_Mark (N));
4361 T := Entity (Subtype_Mark (N));
4363 Check_Fully_Declared (T, N);
4364 Analyze_Expression (Expr);
4365 Validate_Remote_Type_Type_Conversion (N);
4367 -- Only remaining step is validity checks on the argument. These
4368 -- are skipped if the conversion does not come from the source.
4370 if not Comes_From_Source (N) then
4373 -- If there was an error in a generic unit, no need to replicate the
4374 -- error message. Conversely, constant-folding in the generic may
4375 -- transform the argument of a conversion into a string literal, which
4376 -- is legal. Therefore the following tests are not performed in an
4379 elsif In_Instance then
4382 elsif Nkind (Expr) = N_Null then
4383 Error_Msg_N ("argument of conversion cannot be null", N);
4384 Error_Msg_N ("\use qualified expression instead", N);
4385 Set_Etype (N, Any_Type);
4387 elsif Nkind (Expr) = N_Aggregate then
4388 Error_Msg_N ("argument of conversion cannot be aggregate", N);
4389 Error_Msg_N ("\use qualified expression instead", N);
4391 elsif Nkind (Expr) = N_Allocator then
4392 Error_Msg_N ("argument of conversion cannot be an allocator", N);
4393 Error_Msg_N ("\use qualified expression instead", N);
4395 elsif Nkind (Expr) = N_String_Literal then
4396 Error_Msg_N ("argument of conversion cannot be string literal", N);
4397 Error_Msg_N ("\use qualified expression instead", N);
4399 elsif Nkind (Expr) = N_Character_Literal then
4400 if Ada_Version = Ada_83 then
4403 Error_Msg_N ("argument of conversion cannot be character literal",
4405 Error_Msg_N ("\use qualified expression instead", N);
4408 elsif Nkind (Expr) = N_Attribute_Reference
4410 (Attribute_Name (Expr) = Name_Access or else
4411 Attribute_Name (Expr) = Name_Unchecked_Access or else
4412 Attribute_Name (Expr) = Name_Unrestricted_Access)
4414 Error_Msg_N ("argument of conversion cannot be access", N);
4415 Error_Msg_N ("\use qualified expression instead", N);
4417 end Analyze_Type_Conversion;
4419 ----------------------
4420 -- Analyze_Unary_Op --
4421 ----------------------
4423 procedure Analyze_Unary_Op (N : Node_Id) is
4424 R : constant Node_Id := Right_Opnd (N);
4425 Op_Id : Entity_Id := Entity (N);
4428 Set_Etype (N, Any_Type);
4429 Candidate_Type := Empty;
4431 Analyze_Expression (R);
4433 if Present (Op_Id) then
4434 if Ekind (Op_Id) = E_Operator then
4435 Find_Unary_Types (R, Op_Id, N);
4437 Add_One_Interp (N, Op_Id, Etype (Op_Id));
4441 Op_Id := Get_Name_Entity_Id (Chars (N));
4442 while Present (Op_Id) loop
4443 if Ekind (Op_Id) = E_Operator then
4444 if No (Next_Entity (First_Entity (Op_Id))) then
4445 Find_Unary_Types (R, Op_Id, N);
4448 elsif Is_Overloadable (Op_Id) then
4449 Analyze_User_Defined_Unary_Op (N, Op_Id);
4452 Op_Id := Homonym (Op_Id);
4457 end Analyze_Unary_Op;
4459 ----------------------------------
4460 -- Analyze_Unchecked_Expression --
4461 ----------------------------------
4463 procedure Analyze_Unchecked_Expression (N : Node_Id) is
4465 Analyze (Expression (N), Suppress => All_Checks);
4466 Set_Etype (N, Etype (Expression (N)));
4467 Save_Interps (Expression (N), N);
4468 end Analyze_Unchecked_Expression;
4470 ---------------------------------------
4471 -- Analyze_Unchecked_Type_Conversion --
4472 ---------------------------------------
4474 procedure Analyze_Unchecked_Type_Conversion (N : Node_Id) is
4476 Find_Type (Subtype_Mark (N));
4477 Analyze_Expression (Expression (N));
4478 Set_Etype (N, Entity (Subtype_Mark (N)));
4479 end Analyze_Unchecked_Type_Conversion;
4481 ------------------------------------
4482 -- Analyze_User_Defined_Binary_Op --
4483 ------------------------------------
4485 procedure Analyze_User_Defined_Binary_Op
4490 -- Only do analysis if the operator Comes_From_Source, since otherwise
4491 -- the operator was generated by the expander, and all such operators
4492 -- always refer to the operators in package Standard.
4494 if Comes_From_Source (N) then
4496 F1 : constant Entity_Id := First_Formal (Op_Id);
4497 F2 : constant Entity_Id := Next_Formal (F1);
4500 -- Verify that Op_Id is a visible binary function. Note that since
4501 -- we know Op_Id is overloaded, potentially use visible means use
4502 -- visible for sure (RM 9.4(11)).
4504 if Ekind (Op_Id) = E_Function
4505 and then Present (F2)
4506 and then (Is_Immediately_Visible (Op_Id)
4507 or else Is_Potentially_Use_Visible (Op_Id))
4508 and then Has_Compatible_Type (Left_Opnd (N), Etype (F1))
4509 and then Has_Compatible_Type (Right_Opnd (N), Etype (F2))
4511 Add_One_Interp (N, Op_Id, Etype (Op_Id));
4513 -- If the left operand is overloaded, indicate that the
4514 -- current type is a viable candidate. This is redundant
4515 -- in most cases, but for equality and comparison operators
4516 -- where the context does not impose a type on the operands,
4517 -- setting the proper type is necessary to avoid subsequent
4518 -- ambiguities during resolution, when both user-defined and
4519 -- predefined operators may be candidates.
4521 if Is_Overloaded (Left_Opnd (N)) then
4522 Set_Etype (Left_Opnd (N), Etype (F1));
4525 if Debug_Flag_E then
4526 Write_Str ("user defined operator ");
4527 Write_Name (Chars (Op_Id));
4528 Write_Str (" on node ");
4529 Write_Int (Int (N));
4535 end Analyze_User_Defined_Binary_Op;
4537 -----------------------------------
4538 -- Analyze_User_Defined_Unary_Op --
4539 -----------------------------------
4541 procedure Analyze_User_Defined_Unary_Op
4546 -- Only do analysis if the operator Comes_From_Source, since otherwise
4547 -- the operator was generated by the expander, and all such operators
4548 -- always refer to the operators in package Standard.
4550 if Comes_From_Source (N) then
4552 F : constant Entity_Id := First_Formal (Op_Id);
4555 -- Verify that Op_Id is a visible unary function. Note that since
4556 -- we know Op_Id is overloaded, potentially use visible means use
4557 -- visible for sure (RM 9.4(11)).
4559 if Ekind (Op_Id) = E_Function
4560 and then No (Next_Formal (F))
4561 and then (Is_Immediately_Visible (Op_Id)
4562 or else Is_Potentially_Use_Visible (Op_Id))
4563 and then Has_Compatible_Type (Right_Opnd (N), Etype (F))
4565 Add_One_Interp (N, Op_Id, Etype (Op_Id));
4569 end Analyze_User_Defined_Unary_Op;
4571 ---------------------------
4572 -- Check_Arithmetic_Pair --
4573 ---------------------------
4575 procedure Check_Arithmetic_Pair
4576 (T1, T2 : Entity_Id;
4580 Op_Name : constant Name_Id := Chars (Op_Id);
4582 function Has_Fixed_Op (Typ : Entity_Id; Op : Entity_Id) return Boolean;
4583 -- Check whether the fixed-point type Typ has a user-defined operator
4584 -- (multiplication or division) that should hide the corresponding
4585 -- predefined operator. Used to implement Ada 2005 AI-264, to make
4586 -- such operators more visible and therefore useful.
4588 -- If the name of the operation is an expanded name with prefix
4589 -- Standard, the predefined universal fixed operator is available,
4590 -- as specified by AI-420 (RM 4.5.5 (19.1/2)).
4592 function Specific_Type (T1, T2 : Entity_Id) return Entity_Id;
4593 -- Get specific type (i.e. non-universal type if there is one)
4599 function Has_Fixed_Op (Typ : Entity_Id; Op : Entity_Id) return Boolean is
4600 Bas : constant Entity_Id := Base_Type (Typ);
4606 -- If the universal_fixed operation is given explicitly the rule
4607 -- concerning primitive operations of the type do not apply.
4609 if Nkind (N) = N_Function_Call
4610 and then Nkind (Name (N)) = N_Expanded_Name
4611 and then Entity (Prefix (Name (N))) = Standard_Standard
4616 -- The operation is treated as primitive if it is declared in the
4617 -- same scope as the type, and therefore on the same entity chain.
4619 Ent := Next_Entity (Typ);
4620 while Present (Ent) loop
4621 if Chars (Ent) = Chars (Op) then
4622 F1 := First_Formal (Ent);
4623 F2 := Next_Formal (F1);
4625 -- The operation counts as primitive if either operand or
4626 -- result are of the given base type, and both operands are
4627 -- fixed point types.
4629 if (Base_Type (Etype (F1)) = Bas
4630 and then Is_Fixed_Point_Type (Etype (F2)))
4633 (Base_Type (Etype (F2)) = Bas
4634 and then Is_Fixed_Point_Type (Etype (F1)))
4637 (Base_Type (Etype (Ent)) = Bas
4638 and then Is_Fixed_Point_Type (Etype (F1))
4639 and then Is_Fixed_Point_Type (Etype (F2)))
4655 function Specific_Type (T1, T2 : Entity_Id) return Entity_Id is
4657 if T1 = Universal_Integer or else T1 = Universal_Real then
4658 return Base_Type (T2);
4660 return Base_Type (T1);
4664 -- Start of processing for Check_Arithmetic_Pair
4667 if Op_Name = Name_Op_Add or else Op_Name = Name_Op_Subtract then
4669 if Is_Numeric_Type (T1)
4670 and then Is_Numeric_Type (T2)
4671 and then (Covers (T1 => T1, T2 => T2)
4673 Covers (T1 => T2, T2 => T1))
4675 Add_One_Interp (N, Op_Id, Specific_Type (T1, T2));
4678 elsif Op_Name = Name_Op_Multiply or else Op_Name = Name_Op_Divide then
4680 if Is_Fixed_Point_Type (T1)
4681 and then (Is_Fixed_Point_Type (T2)
4682 or else T2 = Universal_Real)
4684 -- If Treat_Fixed_As_Integer is set then the Etype is already set
4685 -- and no further processing is required (this is the case of an
4686 -- operator constructed by Exp_Fixd for a fixed point operation)
4687 -- Otherwise add one interpretation with universal fixed result
4688 -- If the operator is given in functional notation, it comes
4689 -- from source and Fixed_As_Integer cannot apply.
4691 if (Nkind (N) not in N_Op
4692 or else not Treat_Fixed_As_Integer (N))
4694 (not Has_Fixed_Op (T1, Op_Id)
4695 or else Nkind (Parent (N)) = N_Type_Conversion)
4697 Add_One_Interp (N, Op_Id, Universal_Fixed);
4700 elsif Is_Fixed_Point_Type (T2)
4701 and then (Nkind (N) not in N_Op
4702 or else not Treat_Fixed_As_Integer (N))
4703 and then T1 = Universal_Real
4705 (not Has_Fixed_Op (T1, Op_Id)
4706 or else Nkind (Parent (N)) = N_Type_Conversion)
4708 Add_One_Interp (N, Op_Id, Universal_Fixed);
4710 elsif Is_Numeric_Type (T1)
4711 and then Is_Numeric_Type (T2)
4712 and then (Covers (T1 => T1, T2 => T2)
4714 Covers (T1 => T2, T2 => T1))
4716 Add_One_Interp (N, Op_Id, Specific_Type (T1, T2));
4718 elsif Is_Fixed_Point_Type (T1)
4719 and then (Base_Type (T2) = Base_Type (Standard_Integer)
4720 or else T2 = Universal_Integer)
4722 Add_One_Interp (N, Op_Id, T1);
4724 elsif T2 = Universal_Real
4725 and then Base_Type (T1) = Base_Type (Standard_Integer)
4726 and then Op_Name = Name_Op_Multiply
4728 Add_One_Interp (N, Op_Id, Any_Fixed);
4730 elsif T1 = Universal_Real
4731 and then Base_Type (T2) = Base_Type (Standard_Integer)
4733 Add_One_Interp (N, Op_Id, Any_Fixed);
4735 elsif Is_Fixed_Point_Type (T2)
4736 and then (Base_Type (T1) = Base_Type (Standard_Integer)
4737 or else T1 = Universal_Integer)
4738 and then Op_Name = Name_Op_Multiply
4740 Add_One_Interp (N, Op_Id, T2);
4742 elsif T1 = Universal_Real and then T2 = Universal_Integer then
4743 Add_One_Interp (N, Op_Id, T1);
4745 elsif T2 = Universal_Real
4746 and then T1 = Universal_Integer
4747 and then Op_Name = Name_Op_Multiply
4749 Add_One_Interp (N, Op_Id, T2);
4752 elsif Op_Name = Name_Op_Mod or else Op_Name = Name_Op_Rem then
4754 -- Note: The fixed-point operands case with Treat_Fixed_As_Integer
4755 -- set does not require any special processing, since the Etype is
4756 -- already set (case of operation constructed by Exp_Fixed).
4758 if Is_Integer_Type (T1)
4759 and then (Covers (T1 => T1, T2 => T2)
4761 Covers (T1 => T2, T2 => T1))
4763 Add_One_Interp (N, Op_Id, Specific_Type (T1, T2));
4766 elsif Op_Name = Name_Op_Expon then
4767 if Is_Numeric_Type (T1)
4768 and then not Is_Fixed_Point_Type (T1)
4769 and then (Base_Type (T2) = Base_Type (Standard_Integer)
4770 or else T2 = Universal_Integer)
4772 Add_One_Interp (N, Op_Id, Base_Type (T1));
4775 else pragma Assert (Nkind (N) in N_Op_Shift);
4777 -- If not one of the predefined operators, the node may be one
4778 -- of the intrinsic functions. Its kind is always specific, and
4779 -- we can use it directly, rather than the name of the operation.
4781 if Is_Integer_Type (T1)
4782 and then (Base_Type (T2) = Base_Type (Standard_Integer)
4783 or else T2 = Universal_Integer)
4785 Add_One_Interp (N, Op_Id, Base_Type (T1));
4788 end Check_Arithmetic_Pair;
4790 -------------------------------
4791 -- Check_Misspelled_Selector --
4792 -------------------------------
4794 procedure Check_Misspelled_Selector
4795 (Prefix : Entity_Id;
4798 Max_Suggestions : constant := 2;
4799 Nr_Of_Suggestions : Natural := 0;
4801 Suggestion_1 : Entity_Id := Empty;
4802 Suggestion_2 : Entity_Id := Empty;
4807 -- All the components of the prefix of selector Sel are matched
4808 -- against Sel and a count is maintained of possible misspellings.
4809 -- When at the end of the analysis there are one or two (not more!)
4810 -- possible misspellings, these misspellings will be suggested as
4811 -- possible correction.
4813 if not (Is_Private_Type (Prefix) or else Is_Record_Type (Prefix)) then
4815 -- Concurrent types should be handled as well ???
4820 Comp := First_Entity (Prefix);
4821 while Nr_Of_Suggestions <= Max_Suggestions and then Present (Comp) loop
4822 if Is_Visible_Component (Comp) then
4823 if Is_Bad_Spelling_Of (Chars (Comp), Chars (Sel)) then
4824 Nr_Of_Suggestions := Nr_Of_Suggestions + 1;
4826 case Nr_Of_Suggestions is
4827 when 1 => Suggestion_1 := Comp;
4828 when 2 => Suggestion_2 := Comp;
4829 when others => exit;
4834 Comp := Next_Entity (Comp);
4837 -- Report at most two suggestions
4839 if Nr_Of_Suggestions = 1 then
4840 Error_Msg_NE -- CODEFIX
4841 ("\possible misspelling of&", Sel, Suggestion_1);
4843 elsif Nr_Of_Suggestions = 2 then
4844 Error_Msg_Node_2 := Suggestion_2;
4845 Error_Msg_NE -- CODEFIX
4846 ("\possible misspelling of& or&", Sel, Suggestion_1);
4848 end Check_Misspelled_Selector;
4850 ----------------------
4851 -- Defined_In_Scope --
4852 ----------------------
4854 function Defined_In_Scope (T : Entity_Id; S : Entity_Id) return Boolean
4856 S1 : constant Entity_Id := Scope (Base_Type (T));
4859 or else (S1 = System_Aux_Id and then S = Scope (S1));
4860 end Defined_In_Scope;
4866 procedure Diagnose_Call (N : Node_Id; Nam : Node_Id) is
4872 Void_Interp_Seen : Boolean := False;
4875 pragma Warnings (Off, Boolean);
4878 if Ada_Version >= Ada_2005 then
4879 Actual := First_Actual (N);
4880 while Present (Actual) loop
4882 -- Ada 2005 (AI-50217): Post an error in case of premature
4883 -- usage of an entity from the limited view.
4885 if not Analyzed (Etype (Actual))
4886 and then From_With_Type (Etype (Actual))
4888 Error_Msg_Qual_Level := 1;
4890 ("missing with_clause for scope of imported type&",
4891 Actual, Etype (Actual));
4892 Error_Msg_Qual_Level := 0;
4895 Next_Actual (Actual);
4899 -- Analyze each candidate call again, with full error reporting
4903 ("no candidate interpretations match the actuals:!", Nam);
4904 Err_Mode := All_Errors_Mode;
4905 All_Errors_Mode := True;
4907 -- If this is a call to an operation of a concurrent type,
4908 -- the failed interpretations have been removed from the
4909 -- name. Recover them to provide full diagnostics.
4911 if Nkind (Parent (Nam)) = N_Selected_Component then
4912 Set_Entity (Nam, Empty);
4913 New_Nam := New_Copy_Tree (Parent (Nam));
4914 Set_Is_Overloaded (New_Nam, False);
4915 Set_Is_Overloaded (Selector_Name (New_Nam), False);
4916 Set_Parent (New_Nam, Parent (Parent (Nam)));
4917 Analyze_Selected_Component (New_Nam);
4918 Get_First_Interp (Selector_Name (New_Nam), X, It);
4920 Get_First_Interp (Nam, X, It);
4923 while Present (It.Nam) loop
4924 if Etype (It.Nam) = Standard_Void_Type then
4925 Void_Interp_Seen := True;
4928 Analyze_One_Call (N, It.Nam, True, Success);
4929 Get_Next_Interp (X, It);
4932 if Nkind (N) = N_Function_Call then
4933 Get_First_Interp (Nam, X, It);
4934 while Present (It.Nam) loop
4935 if Ekind_In (It.Nam, E_Function, E_Operator) then
4938 Get_Next_Interp (X, It);
4942 -- If all interpretations are procedures, this deserves a
4943 -- more precise message. Ditto if this appears as the prefix
4944 -- of a selected component, which may be a lexical error.
4947 ("\context requires function call, found procedure name", Nam);
4949 if Nkind (Parent (N)) = N_Selected_Component
4950 and then N = Prefix (Parent (N))
4952 Error_Msg_N -- CODEFIX
4953 ("\period should probably be semicolon", Parent (N));
4956 elsif Nkind (N) = N_Procedure_Call_Statement
4957 and then not Void_Interp_Seen
4960 "\function name found in procedure call", Nam);
4963 All_Errors_Mode := Err_Mode;
4966 ---------------------------
4967 -- Find_Arithmetic_Types --
4968 ---------------------------
4970 procedure Find_Arithmetic_Types
4975 Index1 : Interp_Index;
4976 Index2 : Interp_Index;
4980 procedure Check_Right_Argument (T : Entity_Id);
4981 -- Check right operand of operator
4983 --------------------------
4984 -- Check_Right_Argument --
4985 --------------------------
4987 procedure Check_Right_Argument (T : Entity_Id) is
4989 if not Is_Overloaded (R) then
4990 Check_Arithmetic_Pair (T, Etype (R), Op_Id, N);
4992 Get_First_Interp (R, Index2, It2);
4993 while Present (It2.Typ) loop
4994 Check_Arithmetic_Pair (T, It2.Typ, Op_Id, N);
4995 Get_Next_Interp (Index2, It2);
4998 end Check_Right_Argument;
5000 -- Start of processing for Find_Arithmetic_Types
5003 if not Is_Overloaded (L) then
5004 Check_Right_Argument (Etype (L));
5007 Get_First_Interp (L, Index1, It1);
5008 while Present (It1.Typ) loop
5009 Check_Right_Argument (It1.Typ);
5010 Get_Next_Interp (Index1, It1);
5014 end Find_Arithmetic_Types;
5016 ------------------------
5017 -- Find_Boolean_Types --
5018 ------------------------
5020 procedure Find_Boolean_Types
5025 Index : Interp_Index;
5028 procedure Check_Numeric_Argument (T : Entity_Id);
5029 -- Special case for logical operations one of whose operands is an
5030 -- integer literal. If both are literal the result is any modular type.
5032 ----------------------------
5033 -- Check_Numeric_Argument --
5034 ----------------------------
5036 procedure Check_Numeric_Argument (T : Entity_Id) is
5038 if T = Universal_Integer then
5039 Add_One_Interp (N, Op_Id, Any_Modular);
5041 elsif Is_Modular_Integer_Type (T) then
5042 Add_One_Interp (N, Op_Id, T);
5044 end Check_Numeric_Argument;
5046 -- Start of processing for Find_Boolean_Types
5049 if not Is_Overloaded (L) then
5050 if Etype (L) = Universal_Integer
5051 or else Etype (L) = Any_Modular
5053 if not Is_Overloaded (R) then
5054 Check_Numeric_Argument (Etype (R));
5057 Get_First_Interp (R, Index, It);
5058 while Present (It.Typ) loop
5059 Check_Numeric_Argument (It.Typ);
5060 Get_Next_Interp (Index, It);
5064 -- If operands are aggregates, we must assume that they may be
5065 -- boolean arrays, and leave disambiguation for the second pass.
5066 -- If only one is an aggregate, verify that the other one has an
5067 -- interpretation as a boolean array
5069 elsif Nkind (L) = N_Aggregate then
5070 if Nkind (R) = N_Aggregate then
5071 Add_One_Interp (N, Op_Id, Etype (L));
5073 elsif not Is_Overloaded (R) then
5074 if Valid_Boolean_Arg (Etype (R)) then
5075 Add_One_Interp (N, Op_Id, Etype (R));
5079 Get_First_Interp (R, Index, It);
5080 while Present (It.Typ) loop
5081 if Valid_Boolean_Arg (It.Typ) then
5082 Add_One_Interp (N, Op_Id, It.Typ);
5085 Get_Next_Interp (Index, It);
5089 elsif Valid_Boolean_Arg (Etype (L))
5090 and then Has_Compatible_Type (R, Etype (L))
5092 Add_One_Interp (N, Op_Id, Etype (L));
5096 Get_First_Interp (L, Index, It);
5097 while Present (It.Typ) loop
5098 if Valid_Boolean_Arg (It.Typ)
5099 and then Has_Compatible_Type (R, It.Typ)
5101 Add_One_Interp (N, Op_Id, It.Typ);
5104 Get_Next_Interp (Index, It);
5107 end Find_Boolean_Types;
5109 ---------------------------
5110 -- Find_Comparison_Types --
5111 ---------------------------
5113 procedure Find_Comparison_Types
5118 Index : Interp_Index;
5120 Found : Boolean := False;
5123 Scop : Entity_Id := Empty;
5125 procedure Try_One_Interp (T1 : Entity_Id);
5126 -- Routine to try one proposed interpretation. Note that the context
5127 -- of the operator plays no role in resolving the arguments, so that
5128 -- if there is more than one interpretation of the operands that is
5129 -- compatible with comparison, the operation is ambiguous.
5131 --------------------
5132 -- Try_One_Interp --
5133 --------------------
5135 procedure Try_One_Interp (T1 : Entity_Id) is
5138 -- If the operator is an expanded name, then the type of the operand
5139 -- must be defined in the corresponding scope. If the type is
5140 -- universal, the context will impose the correct type.
5143 and then not Defined_In_Scope (T1, Scop)
5144 and then T1 /= Universal_Integer
5145 and then T1 /= Universal_Real
5146 and then T1 /= Any_String
5147 and then T1 /= Any_Composite
5152 if Valid_Comparison_Arg (T1)
5153 and then Has_Compatible_Type (R, T1)
5156 and then Base_Type (T1) /= Base_Type (T_F)
5158 It := Disambiguate (L, I_F, Index, Any_Type);
5160 if It = No_Interp then
5161 Ambiguous_Operands (N);
5162 Set_Etype (L, Any_Type);
5176 Find_Non_Universal_Interpretations (N, R, Op_Id, T1);
5181 -- Start of processing for Find_Comparison_Types
5184 -- If left operand is aggregate, the right operand has to
5185 -- provide a usable type for it.
5187 if Nkind (L) = N_Aggregate
5188 and then Nkind (R) /= N_Aggregate
5190 Find_Comparison_Types (L => R, R => L, Op_Id => Op_Id, N => N);
5194 if Nkind (N) = N_Function_Call
5195 and then Nkind (Name (N)) = N_Expanded_Name
5197 Scop := Entity (Prefix (Name (N)));
5199 -- The prefix may be a package renaming, and the subsequent test
5200 -- requires the original package.
5202 if Ekind (Scop) = E_Package
5203 and then Present (Renamed_Entity (Scop))
5205 Scop := Renamed_Entity (Scop);
5206 Set_Entity (Prefix (Name (N)), Scop);
5210 if not Is_Overloaded (L) then
5211 Try_One_Interp (Etype (L));
5214 Get_First_Interp (L, Index, It);
5215 while Present (It.Typ) loop
5216 Try_One_Interp (It.Typ);
5217 Get_Next_Interp (Index, It);
5220 end Find_Comparison_Types;
5222 ----------------------------------------
5223 -- Find_Non_Universal_Interpretations --
5224 ----------------------------------------
5226 procedure Find_Non_Universal_Interpretations
5232 Index : Interp_Index;
5236 if T1 = Universal_Integer
5237 or else T1 = Universal_Real
5239 if not Is_Overloaded (R) then
5241 (N, Op_Id, Standard_Boolean, Base_Type (Etype (R)));
5243 Get_First_Interp (R, Index, It);
5244 while Present (It.Typ) loop
5245 if Covers (It.Typ, T1) then
5247 (N, Op_Id, Standard_Boolean, Base_Type (It.Typ));
5250 Get_Next_Interp (Index, It);
5254 Add_One_Interp (N, Op_Id, Standard_Boolean, Base_Type (T1));
5256 end Find_Non_Universal_Interpretations;
5258 ------------------------------
5259 -- Find_Concatenation_Types --
5260 ------------------------------
5262 procedure Find_Concatenation_Types
5267 Op_Type : constant Entity_Id := Etype (Op_Id);
5270 if Is_Array_Type (Op_Type)
5271 and then not Is_Limited_Type (Op_Type)
5273 and then (Has_Compatible_Type (L, Op_Type)
5275 Has_Compatible_Type (L, Component_Type (Op_Type)))
5277 and then (Has_Compatible_Type (R, Op_Type)
5279 Has_Compatible_Type (R, Component_Type (Op_Type)))
5281 Add_One_Interp (N, Op_Id, Op_Type);
5283 end Find_Concatenation_Types;
5285 -------------------------
5286 -- Find_Equality_Types --
5287 -------------------------
5289 procedure Find_Equality_Types
5294 Index : Interp_Index;
5296 Found : Boolean := False;
5299 Scop : Entity_Id := Empty;
5301 procedure Try_One_Interp (T1 : Entity_Id);
5302 -- The context of the equality operator plays no role in resolving the
5303 -- arguments, so that if there is more than one interpretation of the
5304 -- operands that is compatible with equality, the construct is ambiguous
5305 -- and an error can be emitted now, after trying to disambiguate, i.e.
5306 -- applying preference rules.
5308 --------------------
5309 -- Try_One_Interp --
5310 --------------------
5312 procedure Try_One_Interp (T1 : Entity_Id) is
5313 Bas : constant Entity_Id := Base_Type (T1);
5316 -- If the operator is an expanded name, then the type of the operand
5317 -- must be defined in the corresponding scope. If the type is
5318 -- universal, the context will impose the correct type. An anonymous
5319 -- type for a 'Access reference is also universal in this sense, as
5320 -- the actual type is obtained from context.
5321 -- In Ada 2005, the equality operator for anonymous access types
5322 -- is declared in Standard, and preference rules apply to it.
5324 if Present (Scop) then
5325 if Defined_In_Scope (T1, Scop)
5326 or else T1 = Universal_Integer
5327 or else T1 = Universal_Real
5328 or else T1 = Any_Access
5329 or else T1 = Any_String
5330 or else T1 = Any_Composite
5331 or else (Ekind (T1) = E_Access_Subprogram_Type
5332 and then not Comes_From_Source (T1))
5336 elsif Ekind (T1) = E_Anonymous_Access_Type
5337 and then Scop = Standard_Standard
5342 -- The scope does not contain an operator for the type
5347 -- If we have infix notation, the operator must be usable.
5348 -- Within an instance, if the type is already established we
5349 -- know it is correct.
5350 -- In Ada 2005, the equality on anonymous access types is declared
5351 -- in Standard, and is always visible.
5353 elsif In_Open_Scopes (Scope (Bas))
5354 or else Is_Potentially_Use_Visible (Bas)
5355 or else In_Use (Bas)
5356 or else (In_Use (Scope (Bas))
5357 and then not Is_Hidden (Bas))
5358 or else (In_Instance
5359 and then First_Subtype (T1) = First_Subtype (Etype (R)))
5360 or else Ekind (T1) = E_Anonymous_Access_Type
5365 -- Save candidate type for subsequent error message, if any
5367 if not Is_Limited_Type (T1) then
5368 Candidate_Type := T1;
5374 -- Ada 2005 (AI-230): Keep restriction imposed by Ada 83 and 95:
5375 -- Do not allow anonymous access types in equality operators.
5377 if Ada_Version < Ada_2005
5378 and then Ekind (T1) = E_Anonymous_Access_Type
5383 if T1 /= Standard_Void_Type
5384 and then not Is_Limited_Type (T1)
5385 and then not Is_Limited_Composite (T1)
5386 and then Has_Compatible_Type (R, T1)
5389 and then Base_Type (T1) /= Base_Type (T_F)
5391 It := Disambiguate (L, I_F, Index, Any_Type);
5393 if It = No_Interp then
5394 Ambiguous_Operands (N);
5395 Set_Etype (L, Any_Type);
5408 if not Analyzed (L) then
5412 Find_Non_Universal_Interpretations (N, R, Op_Id, T1);
5414 -- Case of operator was not visible, Etype still set to Any_Type
5416 if Etype (N) = Any_Type then
5420 elsif Scop = Standard_Standard
5421 and then Ekind (T1) = E_Anonymous_Access_Type
5427 -- Start of processing for Find_Equality_Types
5430 -- If left operand is aggregate, the right operand has to
5431 -- provide a usable type for it.
5433 if Nkind (L) = N_Aggregate
5434 and then Nkind (R) /= N_Aggregate
5436 Find_Equality_Types (L => R, R => L, Op_Id => Op_Id, N => N);
5440 if Nkind (N) = N_Function_Call
5441 and then Nkind (Name (N)) = N_Expanded_Name
5443 Scop := Entity (Prefix (Name (N)));
5445 -- The prefix may be a package renaming, and the subsequent test
5446 -- requires the original package.
5448 if Ekind (Scop) = E_Package
5449 and then Present (Renamed_Entity (Scop))
5451 Scop := Renamed_Entity (Scop);
5452 Set_Entity (Prefix (Name (N)), Scop);
5456 if not Is_Overloaded (L) then
5457 Try_One_Interp (Etype (L));
5460 Get_First_Interp (L, Index, It);
5461 while Present (It.Typ) loop
5462 Try_One_Interp (It.Typ);
5463 Get_Next_Interp (Index, It);
5466 end Find_Equality_Types;
5468 -------------------------
5469 -- Find_Negation_Types --
5470 -------------------------
5472 procedure Find_Negation_Types
5477 Index : Interp_Index;
5481 if not Is_Overloaded (R) then
5482 if Etype (R) = Universal_Integer then
5483 Add_One_Interp (N, Op_Id, Any_Modular);
5484 elsif Valid_Boolean_Arg (Etype (R)) then
5485 Add_One_Interp (N, Op_Id, Etype (R));
5489 Get_First_Interp (R, Index, It);
5490 while Present (It.Typ) loop
5491 if Valid_Boolean_Arg (It.Typ) then
5492 Add_One_Interp (N, Op_Id, It.Typ);
5495 Get_Next_Interp (Index, It);
5498 end Find_Negation_Types;
5500 ------------------------------
5501 -- Find_Primitive_Operation --
5502 ------------------------------
5504 function Find_Primitive_Operation (N : Node_Id) return Boolean is
5505 Obj : constant Node_Id := Prefix (N);
5506 Op : constant Node_Id := Selector_Name (N);
5513 Set_Etype (Op, Any_Type);
5515 if Is_Access_Type (Etype (Obj)) then
5516 Typ := Designated_Type (Etype (Obj));
5521 if Is_Class_Wide_Type (Typ) then
5522 Typ := Root_Type (Typ);
5525 Prims := Primitive_Operations (Typ);
5527 Prim := First_Elmt (Prims);
5528 while Present (Prim) loop
5529 if Chars (Node (Prim)) = Chars (Op) then
5530 Add_One_Interp (Op, Node (Prim), Etype (Node (Prim)));
5531 Set_Etype (N, Etype (Node (Prim)));
5537 -- Now look for class-wide operations of the type or any of its
5538 -- ancestors by iterating over the homonyms of the selector.
5541 Cls_Type : constant Entity_Id := Class_Wide_Type (Typ);
5545 Hom := Current_Entity (Op);
5546 while Present (Hom) loop
5547 if (Ekind (Hom) = E_Procedure
5549 Ekind (Hom) = E_Function)
5550 and then Scope (Hom) = Scope (Typ)
5551 and then Present (First_Formal (Hom))
5553 (Base_Type (Etype (First_Formal (Hom))) = Cls_Type
5555 (Is_Access_Type (Etype (First_Formal (Hom)))
5557 Ekind (Etype (First_Formal (Hom))) =
5558 E_Anonymous_Access_Type
5561 (Designated_Type (Etype (First_Formal (Hom)))) =
5564 Add_One_Interp (Op, Hom, Etype (Hom));
5565 Set_Etype (N, Etype (Hom));
5568 Hom := Homonym (Hom);
5572 return Etype (Op) /= Any_Type;
5573 end Find_Primitive_Operation;
5575 ----------------------
5576 -- Find_Unary_Types --
5577 ----------------------
5579 procedure Find_Unary_Types
5584 Index : Interp_Index;
5588 if not Is_Overloaded (R) then
5589 if Is_Numeric_Type (Etype (R)) then
5590 Add_One_Interp (N, Op_Id, Base_Type (Etype (R)));
5594 Get_First_Interp (R, Index, It);
5595 while Present (It.Typ) loop
5596 if Is_Numeric_Type (It.Typ) then
5597 Add_One_Interp (N, Op_Id, Base_Type (It.Typ));
5600 Get_Next_Interp (Index, It);
5603 end Find_Unary_Types;
5609 function Junk_Operand (N : Node_Id) return Boolean is
5613 if Error_Posted (N) then
5617 -- Get entity to be tested
5619 if Is_Entity_Name (N)
5620 and then Present (Entity (N))
5624 -- An odd case, a procedure name gets converted to a very peculiar
5625 -- function call, and here is where we detect this happening.
5627 elsif Nkind (N) = N_Function_Call
5628 and then Is_Entity_Name (Name (N))
5629 and then Present (Entity (Name (N)))
5633 -- Another odd case, there are at least some cases of selected
5634 -- components where the selected component is not marked as having
5635 -- an entity, even though the selector does have an entity
5637 elsif Nkind (N) = N_Selected_Component
5638 and then Present (Entity (Selector_Name (N)))
5640 Enode := Selector_Name (N);
5646 -- Now test the entity we got to see if it is a bad case
5648 case Ekind (Entity (Enode)) is
5652 ("package name cannot be used as operand", Enode);
5654 when Generic_Unit_Kind =>
5656 ("generic unit name cannot be used as operand", Enode);
5660 ("subtype name cannot be used as operand", Enode);
5664 ("entry name cannot be used as operand", Enode);
5668 ("procedure name cannot be used as operand", Enode);
5672 ("exception name cannot be used as operand", Enode);
5674 when E_Block | E_Label | E_Loop =>
5676 ("label name cannot be used as operand", Enode);
5686 --------------------
5687 -- Operator_Check --
5688 --------------------
5690 procedure Operator_Check (N : Node_Id) is
5692 Remove_Abstract_Operations (N);
5694 -- Test for case of no interpretation found for operator
5696 if Etype (N) = Any_Type then
5700 Op_Id : Entity_Id := Empty;
5703 R := Right_Opnd (N);
5705 if Nkind (N) in N_Binary_Op then
5711 -- If either operand has no type, then don't complain further,
5712 -- since this simply means that we have a propagated error.
5715 or else Etype (R) = Any_Type
5716 or else (Nkind (N) in N_Binary_Op and then Etype (L) = Any_Type)
5720 -- We explicitly check for the case of concatenation of component
5721 -- with component to avoid reporting spurious matching array types
5722 -- that might happen to be lurking in distant packages (such as
5723 -- run-time packages). This also prevents inconsistencies in the
5724 -- messages for certain ACVC B tests, which can vary depending on
5725 -- types declared in run-time interfaces. Another improvement when
5726 -- aggregates are present is to look for a well-typed operand.
5728 elsif Present (Candidate_Type)
5729 and then (Nkind (N) /= N_Op_Concat
5730 or else Is_Array_Type (Etype (L))
5731 or else Is_Array_Type (Etype (R)))
5733 if Nkind (N) = N_Op_Concat then
5734 if Etype (L) /= Any_Composite
5735 and then Is_Array_Type (Etype (L))
5737 Candidate_Type := Etype (L);
5739 elsif Etype (R) /= Any_Composite
5740 and then Is_Array_Type (Etype (R))
5742 Candidate_Type := Etype (R);
5746 Error_Msg_NE -- CODEFIX
5747 ("operator for} is not directly visible!",
5748 N, First_Subtype (Candidate_Type));
5751 U : constant Node_Id :=
5752 Cunit (Get_Source_Unit (Candidate_Type));
5754 if Unit_Is_Visible (U) then
5755 Error_Msg_N -- CODEFIX
5756 ("use clause would make operation legal!", N);
5758 Error_Msg_NE -- CODEFIX
5759 ("add with_clause and use_clause for&!",
5760 N, Defining_Entity (Unit (U)));
5765 -- If either operand is a junk operand (e.g. package name), then
5766 -- post appropriate error messages, but do not complain further.
5768 -- Note that the use of OR in this test instead of OR ELSE is
5769 -- quite deliberate, we may as well check both operands in the
5770 -- binary operator case.
5772 elsif Junk_Operand (R)
5773 or (Nkind (N) in N_Binary_Op and then Junk_Operand (L))
5777 -- If we have a logical operator, one of whose operands is
5778 -- Boolean, then we know that the other operand cannot resolve to
5779 -- Boolean (since we got no interpretations), but in that case we
5780 -- pretty much know that the other operand should be Boolean, so
5781 -- resolve it that way (generating an error)
5783 elsif Nkind_In (N, N_Op_And, N_Op_Or, N_Op_Xor) then
5784 if Etype (L) = Standard_Boolean then
5785 Resolve (R, Standard_Boolean);
5787 elsif Etype (R) = Standard_Boolean then
5788 Resolve (L, Standard_Boolean);
5792 -- For an arithmetic operator or comparison operator, if one
5793 -- of the operands is numeric, then we know the other operand
5794 -- is not the same numeric type. If it is a non-numeric type,
5795 -- then probably it is intended to match the other operand.
5797 elsif Nkind_In (N, N_Op_Add,
5803 Nkind_In (N, N_Op_Lt,
5809 if Is_Numeric_Type (Etype (L))
5810 and then not Is_Numeric_Type (Etype (R))
5812 Resolve (R, Etype (L));
5815 elsif Is_Numeric_Type (Etype (R))
5816 and then not Is_Numeric_Type (Etype (L))
5818 Resolve (L, Etype (R));
5822 -- Comparisons on A'Access are common enough to deserve a
5825 elsif Nkind_In (N, N_Op_Eq, N_Op_Ne)
5826 and then Ekind (Etype (L)) = E_Access_Attribute_Type
5827 and then Ekind (Etype (R)) = E_Access_Attribute_Type
5830 ("two access attributes cannot be compared directly", N);
5832 ("\use qualified expression for one of the operands",
5836 -- Another one for C programmers
5838 elsif Nkind (N) = N_Op_Concat
5839 and then Valid_Boolean_Arg (Etype (L))
5840 and then Valid_Boolean_Arg (Etype (R))
5842 Error_Msg_N ("invalid operands for concatenation", N);
5843 Error_Msg_N -- CODEFIX
5844 ("\maybe AND was meant", N);
5847 -- A special case for comparison of access parameter with null
5849 elsif Nkind (N) = N_Op_Eq
5850 and then Is_Entity_Name (L)
5851 and then Nkind (Parent (Entity (L))) = N_Parameter_Specification
5852 and then Nkind (Parameter_Type (Parent (Entity (L)))) =
5854 and then Nkind (R) = N_Null
5856 Error_Msg_N ("access parameter is not allowed to be null", L);
5857 Error_Msg_N ("\(call would raise Constraint_Error)", L);
5860 -- Another special case for exponentiation, where the right
5861 -- operand must be Natural, independently of the base.
5863 elsif Nkind (N) = N_Op_Expon
5864 and then Is_Numeric_Type (Etype (L))
5865 and then not Is_Overloaded (R)
5867 First_Subtype (Base_Type (Etype (R))) /= Standard_Integer
5868 and then Base_Type (Etype (R)) /= Universal_Integer
5871 ("exponent must be of type Natural, found}", R, Etype (R));
5875 -- If we fall through then just give general message. Note that in
5876 -- the following messages, if the operand is overloaded we choose
5877 -- an arbitrary type to complain about, but that is probably more
5878 -- useful than not giving a type at all.
5880 if Nkind (N) in N_Unary_Op then
5881 Error_Msg_Node_2 := Etype (R);
5882 Error_Msg_N ("operator& not defined for}", N);
5886 if Nkind (N) in N_Binary_Op then
5887 if not Is_Overloaded (L)
5888 and then not Is_Overloaded (R)
5889 and then Base_Type (Etype (L)) = Base_Type (Etype (R))
5891 Error_Msg_Node_2 := First_Subtype (Etype (R));
5892 Error_Msg_N ("there is no applicable operator& for}", N);
5895 -- Another attempt to find a fix: one of the candidate
5896 -- interpretations may not be use-visible. This has
5897 -- already been checked for predefined operators, so
5898 -- we examine only user-defined functions.
5900 Op_Id := Get_Name_Entity_Id (Chars (N));
5902 while Present (Op_Id) loop
5903 if Ekind (Op_Id) /= E_Operator
5904 and then Is_Overloadable (Op_Id)
5906 if not Is_Immediately_Visible (Op_Id)
5907 and then not In_Use (Scope (Op_Id))
5908 and then not Is_Abstract_Subprogram (Op_Id)
5909 and then not Is_Hidden (Op_Id)
5910 and then Ekind (Scope (Op_Id)) = E_Package
5913 (L, Etype (First_Formal (Op_Id)))
5915 (Next_Formal (First_Formal (Op_Id)))
5919 Etype (Next_Formal (First_Formal (Op_Id))))
5922 ("No legal interpretation for operator&", N);
5924 ("\use clause on& would make operation legal",
5930 Op_Id := Homonym (Op_Id);
5934 Error_Msg_N ("invalid operand types for operator&", N);
5936 if Nkind (N) /= N_Op_Concat then
5937 Error_Msg_NE ("\left operand has}!", N, Etype (L));
5938 Error_Msg_NE ("\right operand has}!", N, Etype (R));
5948 -----------------------------------------
5949 -- Process_Implicit_Dereference_Prefix --
5950 -----------------------------------------
5952 function Process_Implicit_Dereference_Prefix
5954 P : Entity_Id) return Entity_Id
5957 Typ : constant Entity_Id := Designated_Type (Etype (P));
5961 and then (Operating_Mode = Check_Semantics or else not Expander_Active)
5963 -- We create a dummy reference to E to ensure that the reference
5964 -- is not considered as part of an assignment (an implicit
5965 -- dereference can never assign to its prefix). The Comes_From_Source
5966 -- attribute needs to be propagated for accurate warnings.
5968 Ref := New_Reference_To (E, Sloc (P));
5969 Set_Comes_From_Source (Ref, Comes_From_Source (P));
5970 Generate_Reference (E, Ref);
5973 -- An implicit dereference is a legal occurrence of an
5974 -- incomplete type imported through a limited_with clause,
5975 -- if the full view is visible.
5977 if From_With_Type (Typ)
5978 and then not From_With_Type (Scope (Typ))
5980 (Is_Immediately_Visible (Scope (Typ))
5982 (Is_Child_Unit (Scope (Typ))
5983 and then Is_Visible_Child_Unit (Scope (Typ))))
5985 return Available_View (Typ);
5990 end Process_Implicit_Dereference_Prefix;
5992 --------------------------------
5993 -- Remove_Abstract_Operations --
5994 --------------------------------
5996 procedure Remove_Abstract_Operations (N : Node_Id) is
5997 Abstract_Op : Entity_Id := Empty;
5998 Address_Kludge : Boolean := False;
6002 -- AI-310: If overloaded, remove abstract non-dispatching operations. We
6003 -- activate this if either extensions are enabled, or if the abstract
6004 -- operation in question comes from a predefined file. This latter test
6005 -- allows us to use abstract to make operations invisible to users. In
6006 -- particular, if type Address is non-private and abstract subprograms
6007 -- are used to hide its operators, they will be truly hidden.
6009 type Operand_Position is (First_Op, Second_Op);
6010 Univ_Type : constant Entity_Id := Universal_Interpretation (N);
6012 procedure Remove_Address_Interpretations (Op : Operand_Position);
6013 -- Ambiguities may arise when the operands are literal and the address
6014 -- operations in s-auxdec are visible. In that case, remove the
6015 -- interpretation of a literal as Address, to retain the semantics of
6016 -- Address as a private type.
6018 ------------------------------------
6019 -- Remove_Address_Interpretations --
6020 ------------------------------------
6022 procedure Remove_Address_Interpretations (Op : Operand_Position) is
6026 if Is_Overloaded (N) then
6027 Get_First_Interp (N, I, It);
6028 while Present (It.Nam) loop
6029 Formal := First_Entity (It.Nam);
6031 if Op = Second_Op then
6032 Formal := Next_Entity (Formal);
6035 if Is_Descendent_Of_Address (Etype (Formal)) then
6036 Address_Kludge := True;
6040 Get_Next_Interp (I, It);
6043 end Remove_Address_Interpretations;
6045 -- Start of processing for Remove_Abstract_Operations
6048 if Is_Overloaded (N) then
6049 Get_First_Interp (N, I, It);
6051 while Present (It.Nam) loop
6052 if Is_Overloadable (It.Nam)
6053 and then Is_Abstract_Subprogram (It.Nam)
6054 and then not Is_Dispatching_Operation (It.Nam)
6056 Abstract_Op := It.Nam;
6058 if Is_Descendent_Of_Address (It.Typ) then
6059 Address_Kludge := True;
6063 -- In Ada 2005, this operation does not participate in Overload
6064 -- resolution. If the operation is defined in a predefined
6065 -- unit, it is one of the operations declared abstract in some
6066 -- variants of System, and it must be removed as well.
6068 elsif Ada_Version >= Ada_2005
6069 or else Is_Predefined_File_Name
6070 (Unit_File_Name (Get_Source_Unit (It.Nam)))
6077 Get_Next_Interp (I, It);
6080 if No (Abstract_Op) then
6082 -- If some interpretation yields an integer type, it is still
6083 -- possible that there are address interpretations. Remove them
6084 -- if one operand is a literal, to avoid spurious ambiguities
6085 -- on systems where Address is a visible integer type.
6087 if Is_Overloaded (N)
6088 and then Nkind (N) in N_Op
6089 and then Is_Integer_Type (Etype (N))
6091 if Nkind (N) in N_Binary_Op then
6092 if Nkind (Right_Opnd (N)) = N_Integer_Literal then
6093 Remove_Address_Interpretations (Second_Op);
6095 elsif Nkind (Right_Opnd (N)) = N_Integer_Literal then
6096 Remove_Address_Interpretations (First_Op);
6101 elsif Nkind (N) in N_Op then
6103 -- Remove interpretations that treat literals as addresses. This
6104 -- is never appropriate, even when Address is defined as a visible
6105 -- Integer type. The reason is that we would really prefer Address
6106 -- to behave as a private type, even in this case, which is there
6107 -- only to accommodate oddities of VMS address sizes. If Address
6108 -- is a visible integer type, we get lots of overload ambiguities.
6110 if Nkind (N) in N_Binary_Op then
6112 U1 : constant Boolean :=
6113 Present (Universal_Interpretation (Right_Opnd (N)));
6114 U2 : constant Boolean :=
6115 Present (Universal_Interpretation (Left_Opnd (N)));
6119 Remove_Address_Interpretations (Second_Op);
6123 Remove_Address_Interpretations (First_Op);
6126 if not (U1 and U2) then
6128 -- Remove corresponding predefined operator, which is
6129 -- always added to the overload set.
6131 Get_First_Interp (N, I, It);
6132 while Present (It.Nam) loop
6133 if Scope (It.Nam) = Standard_Standard
6134 and then Base_Type (It.Typ) =
6135 Base_Type (Etype (Abstract_Op))
6140 Get_Next_Interp (I, It);
6143 elsif Is_Overloaded (N)
6144 and then Present (Univ_Type)
6146 -- If both operands have a universal interpretation,
6147 -- it is still necessary to remove interpretations that
6148 -- yield Address. Any remaining ambiguities will be
6149 -- removed in Disambiguate.
6151 Get_First_Interp (N, I, It);
6152 while Present (It.Nam) loop
6153 if Is_Descendent_Of_Address (It.Typ) then
6156 elsif not Is_Type (It.Nam) then
6157 Set_Entity (N, It.Nam);
6160 Get_Next_Interp (I, It);
6166 elsif Nkind (N) = N_Function_Call
6168 (Nkind (Name (N)) = N_Operator_Symbol
6170 (Nkind (Name (N)) = N_Expanded_Name
6172 Nkind (Selector_Name (Name (N))) = N_Operator_Symbol))
6176 Arg1 : constant Node_Id := First (Parameter_Associations (N));
6177 U1 : constant Boolean :=
6178 Present (Universal_Interpretation (Arg1));
6179 U2 : constant Boolean :=
6180 Present (Next (Arg1)) and then
6181 Present (Universal_Interpretation (Next (Arg1)));
6185 Remove_Address_Interpretations (First_Op);
6189 Remove_Address_Interpretations (Second_Op);
6192 if not (U1 and U2) then
6193 Get_First_Interp (N, I, It);
6194 while Present (It.Nam) loop
6195 if Scope (It.Nam) = Standard_Standard
6196 and then It.Typ = Base_Type (Etype (Abstract_Op))
6201 Get_Next_Interp (I, It);
6207 -- If the removal has left no valid interpretations, emit an error
6208 -- message now and label node as illegal.
6210 if Present (Abstract_Op) then
6211 Get_First_Interp (N, I, It);
6215 -- Removal of abstract operation left no viable candidate
6217 Set_Etype (N, Any_Type);
6218 Error_Msg_Sloc := Sloc (Abstract_Op);
6220 ("cannot call abstract operation& declared#", N, Abstract_Op);
6222 -- In Ada 2005, an abstract operation may disable predefined
6223 -- operators. Since the context is not yet known, we mark the
6224 -- predefined operators as potentially hidden. Do not include
6225 -- predefined operators when addresses are involved since this
6226 -- case is handled separately.
6228 elsif Ada_Version >= Ada_2005
6229 and then not Address_Kludge
6231 while Present (It.Nam) loop
6232 if Is_Numeric_Type (It.Typ)
6233 and then Scope (It.Typ) = Standard_Standard
6235 Set_Abstract_Op (I, Abstract_Op);
6238 Get_Next_Interp (I, It);
6243 end Remove_Abstract_Operations;
6245 -----------------------
6246 -- Try_Indirect_Call --
6247 -----------------------
6249 function Try_Indirect_Call
6252 Typ : Entity_Id) return Boolean
6258 pragma Warnings (Off, Call_OK);
6261 Normalize_Actuals (N, Designated_Type (Typ), False, Call_OK);
6263 Actual := First_Actual (N);
6264 Formal := First_Formal (Designated_Type (Typ));
6265 while Present (Actual) and then Present (Formal) loop
6266 if not Has_Compatible_Type (Actual, Etype (Formal)) then
6271 Next_Formal (Formal);
6274 if No (Actual) and then No (Formal) then
6275 Add_One_Interp (N, Nam, Etype (Designated_Type (Typ)));
6277 -- Nam is a candidate interpretation for the name in the call,
6278 -- if it is not an indirect call.
6280 if not Is_Type (Nam)
6281 and then Is_Entity_Name (Name (N))
6283 Set_Entity (Name (N), Nam);
6290 end Try_Indirect_Call;
6292 ----------------------
6293 -- Try_Indexed_Call --
6294 ----------------------
6296 function Try_Indexed_Call
6300 Skip_First : Boolean) return Boolean
6302 Loc : constant Source_Ptr := Sloc (N);
6303 Actuals : constant List_Id := Parameter_Associations (N);
6308 Actual := First (Actuals);
6310 -- If the call was originally written in prefix form, skip the first
6311 -- actual, which is obviously not defaulted.
6317 Index := First_Index (Typ);
6318 while Present (Actual) and then Present (Index) loop
6320 -- If the parameter list has a named association, the expression
6321 -- is definitely a call and not an indexed component.
6323 if Nkind (Actual) = N_Parameter_Association then
6327 if Is_Entity_Name (Actual)
6328 and then Is_Type (Entity (Actual))
6329 and then No (Next (Actual))
6331 -- A single actual that is a type name indicates a slice if the
6332 -- type is discrete, and an error otherwise.
6334 if Is_Discrete_Type (Entity (Actual)) then
6338 Make_Function_Call (Loc,
6339 Name => Relocate_Node (Name (N))),
6341 New_Occurrence_Of (Entity (Actual), Sloc (Actual))));
6346 Error_Msg_N ("invalid use of type in expression", Actual);
6347 Set_Etype (N, Any_Type);
6352 elsif not Has_Compatible_Type (Actual, Etype (Index)) then
6360 if No (Actual) and then No (Index) then
6361 Add_One_Interp (N, Nam, Component_Type (Typ));
6363 -- Nam is a candidate interpretation for the name in the call,
6364 -- if it is not an indirect call.
6366 if not Is_Type (Nam)
6367 and then Is_Entity_Name (Name (N))
6369 Set_Entity (Name (N), Nam);
6376 end Try_Indexed_Call;
6378 --------------------------
6379 -- Try_Object_Operation --
6380 --------------------------
6382 function Try_Object_Operation (N : Node_Id) return Boolean is
6383 K : constant Node_Kind := Nkind (Parent (N));
6384 Is_Subprg_Call : constant Boolean := Nkind_In
6385 (K, N_Procedure_Call_Statement,
6387 Loc : constant Source_Ptr := Sloc (N);
6388 Obj : constant Node_Id := Prefix (N);
6390 Subprog : constant Node_Id :=
6391 Make_Identifier (Sloc (Selector_Name (N)),
6392 Chars => Chars (Selector_Name (N)));
6393 -- Identifier on which possible interpretations will be collected
6395 Report_Error : Boolean := False;
6396 -- If no candidate interpretation matches the context, redo the
6397 -- analysis with error enabled to provide additional information.
6400 Candidate : Entity_Id := Empty;
6401 New_Call_Node : Node_Id := Empty;
6402 Node_To_Replace : Node_Id;
6403 Obj_Type : Entity_Id := Etype (Obj);
6404 Success : Boolean := False;
6406 function Valid_Candidate
6409 Subp : Entity_Id) return Entity_Id;
6410 -- If the subprogram is a valid interpretation, record it, and add
6411 -- to the list of interpretations of Subprog.
6413 procedure Complete_Object_Operation
6414 (Call_Node : Node_Id;
6415 Node_To_Replace : Node_Id);
6416 -- Make Subprog the name of Call_Node, replace Node_To_Replace with
6417 -- Call_Node, insert the object (or its dereference) as the first actual
6418 -- in the call, and complete the analysis of the call.
6420 procedure Report_Ambiguity (Op : Entity_Id);
6421 -- If a prefixed procedure call is ambiguous, indicate whether the
6422 -- call includes an implicit dereference or an implicit 'Access.
6424 procedure Transform_Object_Operation
6425 (Call_Node : out Node_Id;
6426 Node_To_Replace : out Node_Id);
6427 -- Transform Obj.Operation (X, Y,,) into Operation (Obj, X, Y ..)
6428 -- Call_Node is the resulting subprogram call, Node_To_Replace is
6429 -- either N or the parent of N, and Subprog is a reference to the
6430 -- subprogram we are trying to match.
6432 function Try_Class_Wide_Operation
6433 (Call_Node : Node_Id;
6434 Node_To_Replace : Node_Id) return Boolean;
6435 -- Traverse all ancestor types looking for a class-wide subprogram
6436 -- for which the current operation is a valid non-dispatching call.
6438 procedure Try_One_Prefix_Interpretation (T : Entity_Id);
6439 -- If prefix is overloaded, its interpretation may include different
6440 -- tagged types, and we must examine the primitive operations and
6441 -- the class-wide operations of each in order to find candidate
6442 -- interpretations for the call as a whole.
6444 function Try_Primitive_Operation
6445 (Call_Node : Node_Id;
6446 Node_To_Replace : Node_Id) return Boolean;
6447 -- Traverse the list of primitive subprograms looking for a dispatching
6448 -- operation for which the current node is a valid call .
6450 ---------------------
6451 -- Valid_Candidate --
6452 ---------------------
6454 function Valid_Candidate
6457 Subp : Entity_Id) return Entity_Id
6459 Arr_Type : Entity_Id;
6460 Comp_Type : Entity_Id;
6463 -- If the subprogram is a valid interpretation, record it in global
6464 -- variable Subprog, to collect all possible overloadings.
6467 if Subp /= Entity (Subprog) then
6468 Add_One_Interp (Subprog, Subp, Etype (Subp));
6472 -- If the call may be an indexed call, retrieve component type of
6473 -- resulting expression, and add possible interpretation.
6478 if Nkind (Call) = N_Function_Call
6479 and then Nkind (Parent (N)) = N_Indexed_Component
6480 and then Needs_One_Actual (Subp)
6482 if Is_Array_Type (Etype (Subp)) then
6483 Arr_Type := Etype (Subp);
6485 elsif Is_Access_Type (Etype (Subp))
6486 and then Is_Array_Type (Designated_Type (Etype (Subp)))
6488 Arr_Type := Designated_Type (Etype (Subp));
6492 if Present (Arr_Type) then
6494 -- Verify that the actuals (excluding the object) match the types
6502 Actual := Next (First_Actual (Call));
6503 Index := First_Index (Arr_Type);
6504 while Present (Actual) and then Present (Index) loop
6505 if not Has_Compatible_Type (Actual, Etype (Index)) then
6510 Next_Actual (Actual);
6516 and then Present (Arr_Type)
6518 Comp_Type := Component_Type (Arr_Type);
6522 if Present (Comp_Type)
6523 and then Etype (Subprog) /= Comp_Type
6525 Add_One_Interp (Subprog, Subp, Comp_Type);
6529 if Etype (Call) /= Any_Type then
6534 end Valid_Candidate;
6536 -------------------------------
6537 -- Complete_Object_Operation --
6538 -------------------------------
6540 procedure Complete_Object_Operation
6541 (Call_Node : Node_Id;
6542 Node_To_Replace : Node_Id)
6544 Control : constant Entity_Id := First_Formal (Entity (Subprog));
6545 Formal_Type : constant Entity_Id := Etype (Control);
6546 First_Actual : Node_Id;
6549 -- Place the name of the operation, with its interpretations,
6550 -- on the rewritten call.
6552 Set_Name (Call_Node, Subprog);
6554 First_Actual := First (Parameter_Associations (Call_Node));
6556 -- For cross-reference purposes, treat the new node as being in
6557 -- the source if the original one is.
6559 Set_Comes_From_Source (Subprog, Comes_From_Source (N));
6560 Set_Comes_From_Source (Call_Node, Comes_From_Source (N));
6562 if Nkind (N) = N_Selected_Component
6563 and then not Inside_A_Generic
6565 Set_Entity (Selector_Name (N), Entity (Subprog));
6568 -- If need be, rewrite first actual as an explicit dereference
6569 -- If the call is overloaded, the rewriting can only be done
6570 -- once the primitive operation is identified.
6572 if Is_Overloaded (Subprog) then
6574 -- The prefix itself may be overloaded, and its interpretations
6575 -- must be propagated to the new actual in the call.
6577 if Is_Overloaded (Obj) then
6578 Save_Interps (Obj, First_Actual);
6581 Rewrite (First_Actual, Obj);
6583 elsif not Is_Access_Type (Formal_Type)
6584 and then Is_Access_Type (Etype (Obj))
6586 Rewrite (First_Actual,
6587 Make_Explicit_Dereference (Sloc (Obj), Obj));
6588 Analyze (First_Actual);
6590 -- If we need to introduce an explicit dereference, verify that
6591 -- the resulting actual is compatible with the mode of the formal.
6593 if Ekind (First_Formal (Entity (Subprog))) /= E_In_Parameter
6594 and then Is_Access_Constant (Etype (Obj))
6597 ("expect variable in call to&", Prefix (N), Entity (Subprog));
6600 -- Conversely, if the formal is an access parameter and the object
6601 -- is not, replace the actual with a 'Access reference. Its analysis
6602 -- will check that the object is aliased.
6604 elsif Is_Access_Type (Formal_Type)
6605 and then not Is_Access_Type (Etype (Obj))
6607 -- A special case: A.all'access is illegal if A is an access to a
6608 -- constant and the context requires an access to a variable.
6610 if not Is_Access_Constant (Formal_Type) then
6611 if (Nkind (Obj) = N_Explicit_Dereference
6612 and then Is_Access_Constant (Etype (Prefix (Obj))))
6613 or else not Is_Variable (Obj)
6616 ("actual for& must be a variable", Obj, Control);
6620 Rewrite (First_Actual,
6621 Make_Attribute_Reference (Loc,
6622 Attribute_Name => Name_Access,
6623 Prefix => Relocate_Node (Obj)));
6625 if not Is_Aliased_View (Obj) then
6627 ("object in prefixed call to& must be aliased"
6628 & " (RM-2005 4.3.1 (13))",
6629 Prefix (First_Actual), Subprog);
6632 Analyze (First_Actual);
6635 if Is_Overloaded (Obj) then
6636 Save_Interps (Obj, First_Actual);
6639 Rewrite (First_Actual, Obj);
6642 Rewrite (Node_To_Replace, Call_Node);
6644 -- Propagate the interpretations collected in subprog to the new
6645 -- function call node, to be resolved from context.
6647 if Is_Overloaded (Subprog) then
6648 Save_Interps (Subprog, Node_To_Replace);
6651 Analyze (Node_To_Replace);
6653 -- If the operation has been rewritten into a call, which may get
6654 -- subsequently an explicit dereference, preserve the type on the
6655 -- original node (selected component or indexed component) for
6656 -- subsequent legality tests, e.g. Is_Variable. which examines
6657 -- the original node.
6659 if Nkind (Node_To_Replace) = N_Function_Call then
6661 (Original_Node (Node_To_Replace), Etype (Node_To_Replace));
6664 end Complete_Object_Operation;
6666 ----------------------
6667 -- Report_Ambiguity --
6668 ----------------------
6670 procedure Report_Ambiguity (Op : Entity_Id) is
6671 Access_Formal : constant Boolean :=
6672 Is_Access_Type (Etype (First_Formal (Op)));
6673 Access_Actual : constant Boolean :=
6674 Is_Access_Type (Etype (Prefix (N)));
6677 Error_Msg_Sloc := Sloc (Op);
6679 if Access_Formal and then not Access_Actual then
6680 if Nkind (Parent (Op)) = N_Full_Type_Declaration then
6682 ("\possible interpretation"
6683 & " (inherited, with implicit 'Access) #", N);
6686 ("\possible interpretation (with implicit 'Access) #", N);
6689 elsif not Access_Formal and then Access_Actual then
6690 if Nkind (Parent (Op)) = N_Full_Type_Declaration then
6692 ("\possible interpretation"
6693 & " ( inherited, with implicit dereference) #", N);
6696 ("\possible interpretation (with implicit dereference) #", N);
6700 if Nkind (Parent (Op)) = N_Full_Type_Declaration then
6701 Error_Msg_N ("\possible interpretation (inherited)#", N);
6703 Error_Msg_N -- CODEFIX
6704 ("\possible interpretation#", N);
6707 end Report_Ambiguity;
6709 --------------------------------
6710 -- Transform_Object_Operation --
6711 --------------------------------
6713 procedure Transform_Object_Operation
6714 (Call_Node : out Node_Id;
6715 Node_To_Replace : out Node_Id)
6717 Dummy : constant Node_Id := New_Copy (Obj);
6718 -- Placeholder used as a first parameter in the call, replaced
6719 -- eventually by the proper object.
6721 Parent_Node : constant Node_Id := Parent (N);
6727 -- Common case covering 1) Call to a procedure and 2) Call to a
6728 -- function that has some additional actuals.
6730 if Nkind_In (Parent_Node, N_Function_Call,
6731 N_Procedure_Call_Statement)
6733 -- N is a selected component node containing the name of the
6734 -- subprogram. If N is not the name of the parent node we must
6735 -- not replace the parent node by the new construct. This case
6736 -- occurs when N is a parameterless call to a subprogram that
6737 -- is an actual parameter of a call to another subprogram. For
6739 -- Some_Subprogram (..., Obj.Operation, ...)
6741 and then Name (Parent_Node) = N
6743 Node_To_Replace := Parent_Node;
6745 Actuals := Parameter_Associations (Parent_Node);
6747 if Present (Actuals) then
6748 Prepend (Dummy, Actuals);
6750 Actuals := New_List (Dummy);
6753 if Nkind (Parent_Node) = N_Procedure_Call_Statement then
6755 Make_Procedure_Call_Statement (Loc,
6756 Name => New_Copy (Subprog),
6757 Parameter_Associations => Actuals);
6761 Make_Function_Call (Loc,
6762 Name => New_Copy (Subprog),
6763 Parameter_Associations => Actuals);
6767 -- Before analysis, a function call appears as an indexed component
6768 -- if there are no named associations.
6770 elsif Nkind (Parent_Node) = N_Indexed_Component
6771 and then N = Prefix (Parent_Node)
6773 Node_To_Replace := Parent_Node;
6774 Actuals := Expressions (Parent_Node);
6776 Actual := First (Actuals);
6777 while Present (Actual) loop
6782 Prepend (Dummy, Actuals);
6785 Make_Function_Call (Loc,
6786 Name => New_Copy (Subprog),
6787 Parameter_Associations => Actuals);
6789 -- Parameterless call: Obj.F is rewritten as F (Obj)
6792 Node_To_Replace := N;
6795 Make_Function_Call (Loc,
6796 Name => New_Copy (Subprog),
6797 Parameter_Associations => New_List (Dummy));
6799 end Transform_Object_Operation;
6801 ------------------------------
6802 -- Try_Class_Wide_Operation --
6803 ------------------------------
6805 function Try_Class_Wide_Operation
6806 (Call_Node : Node_Id;
6807 Node_To_Replace : Node_Id) return Boolean
6809 Anc_Type : Entity_Id;
6810 Matching_Op : Entity_Id := Empty;
6813 procedure Traverse_Homonyms
6814 (Anc_Type : Entity_Id;
6815 Error : out Boolean);
6816 -- Traverse the homonym chain of the subprogram searching for those
6817 -- homonyms whose first formal has the Anc_Type's class-wide type,
6818 -- or an anonymous access type designating the class-wide type. If
6819 -- an ambiguity is detected, then Error is set to True.
6821 procedure Traverse_Interfaces
6822 (Anc_Type : Entity_Id;
6823 Error : out Boolean);
6824 -- Traverse the list of interfaces, if any, associated with Anc_Type
6825 -- and search for acceptable class-wide homonyms associated with each
6826 -- interface. If an ambiguity is detected, then Error is set to True.
6828 -----------------------
6829 -- Traverse_Homonyms --
6830 -----------------------
6832 procedure Traverse_Homonyms
6833 (Anc_Type : Entity_Id;
6834 Error : out Boolean)
6836 Cls_Type : Entity_Id;
6844 Cls_Type := Class_Wide_Type (Anc_Type);
6846 Hom := Current_Entity (Subprog);
6848 -- Find a non-hidden operation whose first parameter is of the
6849 -- class-wide type, a subtype thereof, or an anonymous access
6852 while Present (Hom) loop
6853 if Ekind_In (Hom, E_Procedure, E_Function)
6854 and then not Is_Hidden (Hom)
6855 and then Scope (Hom) = Scope (Anc_Type)
6856 and then Present (First_Formal (Hom))
6858 (Base_Type (Etype (First_Formal (Hom))) = Cls_Type
6860 (Is_Access_Type (Etype (First_Formal (Hom)))
6862 Ekind (Etype (First_Formal (Hom))) =
6863 E_Anonymous_Access_Type
6866 (Designated_Type (Etype (First_Formal (Hom)))) =
6869 -- If the context is a procedure call, ignore functions
6870 -- in the name of the call.
6872 if Ekind (Hom) = E_Function
6873 and then Nkind (Parent (N)) = N_Procedure_Call_Statement
6874 and then N = Name (Parent (N))
6879 Set_Etype (Call_Node, Any_Type);
6880 Set_Is_Overloaded (Call_Node, False);
6883 if No (Matching_Op) then
6884 Hom_Ref := New_Reference_To (Hom, Sloc (Subprog));
6885 Set_Etype (Call_Node, Any_Type);
6886 Set_Parent (Call_Node, Parent (Node_To_Replace));
6888 Set_Name (Call_Node, Hom_Ref);
6893 Report => Report_Error,
6895 Skip_First => True);
6898 Valid_Candidate (Success, Call_Node, Hom);
6904 Report => Report_Error,
6906 Skip_First => True);
6908 if Present (Valid_Candidate (Success, Call_Node, Hom))
6909 and then Nkind (Call_Node) /= N_Function_Call
6911 Error_Msg_NE ("ambiguous call to&", N, Hom);
6912 Report_Ambiguity (Matching_Op);
6913 Report_Ambiguity (Hom);
6921 Hom := Homonym (Hom);
6923 end Traverse_Homonyms;
6925 -------------------------
6926 -- Traverse_Interfaces --
6927 -------------------------
6929 procedure Traverse_Interfaces
6930 (Anc_Type : Entity_Id;
6931 Error : out Boolean)
6933 Intface_List : constant List_Id :=
6934 Abstract_Interface_List (Anc_Type);
6940 if Is_Non_Empty_List (Intface_List) then
6941 Intface := First (Intface_List);
6942 while Present (Intface) loop
6944 -- Look for acceptable class-wide homonyms associated with
6947 Traverse_Homonyms (Etype (Intface), Error);
6953 -- Continue the search by looking at each of the interface's
6954 -- associated interface ancestors.
6956 Traverse_Interfaces (Etype (Intface), Error);
6965 end Traverse_Interfaces;
6967 -- Start of processing for Try_Class_Wide_Operation
6970 -- Loop through ancestor types (including interfaces), traversing
6971 -- the homonym chain of the subprogram, trying out those homonyms
6972 -- whose first formal has the class-wide type of the ancestor, or
6973 -- an anonymous access type designating the class-wide type.
6975 Anc_Type := Obj_Type;
6977 -- Look for a match among homonyms associated with the ancestor
6979 Traverse_Homonyms (Anc_Type, Error);
6985 -- Continue the search for matches among homonyms associated with
6986 -- any interfaces implemented by the ancestor.
6988 Traverse_Interfaces (Anc_Type, Error);
6994 exit when Etype (Anc_Type) = Anc_Type;
6995 Anc_Type := Etype (Anc_Type);
6998 if Present (Matching_Op) then
6999 Set_Etype (Call_Node, Etype (Matching_Op));
7002 return Present (Matching_Op);
7003 end Try_Class_Wide_Operation;
7005 -----------------------------------
7006 -- Try_One_Prefix_Interpretation --
7007 -----------------------------------
7009 procedure Try_One_Prefix_Interpretation (T : Entity_Id) is
7013 if Is_Access_Type (Obj_Type) then
7014 Obj_Type := Designated_Type (Obj_Type);
7017 if Ekind (Obj_Type) = E_Private_Subtype then
7018 Obj_Type := Base_Type (Obj_Type);
7021 if Is_Class_Wide_Type (Obj_Type) then
7022 Obj_Type := Etype (Class_Wide_Type (Obj_Type));
7025 -- The type may have be obtained through a limited_with clause,
7026 -- in which case the primitive operations are available on its
7027 -- non-limited view. If still incomplete, retrieve full view.
7029 if Ekind (Obj_Type) = E_Incomplete_Type
7030 and then From_With_Type (Obj_Type)
7032 Obj_Type := Get_Full_View (Non_Limited_View (Obj_Type));
7035 -- If the object is not tagged, or the type is still an incomplete
7036 -- type, this is not a prefixed call.
7038 if not Is_Tagged_Type (Obj_Type)
7039 or else Is_Incomplete_Type (Obj_Type)
7044 if Try_Primitive_Operation
7045 (Call_Node => New_Call_Node,
7046 Node_To_Replace => Node_To_Replace)
7048 Try_Class_Wide_Operation
7049 (Call_Node => New_Call_Node,
7050 Node_To_Replace => Node_To_Replace)
7054 end Try_One_Prefix_Interpretation;
7056 -----------------------------
7057 -- Try_Primitive_Operation --
7058 -----------------------------
7060 function Try_Primitive_Operation
7061 (Call_Node : Node_Id;
7062 Node_To_Replace : Node_Id) return Boolean
7065 Prim_Op : Entity_Id;
7066 Matching_Op : Entity_Id := Empty;
7067 Prim_Op_Ref : Node_Id := Empty;
7069 Corr_Type : Entity_Id := Empty;
7070 -- If the prefix is a synchronized type, the controlling type of
7071 -- the primitive operation is the corresponding record type, else
7072 -- this is the object type itself.
7074 Success : Boolean := False;
7076 function Collect_Generic_Type_Ops (T : Entity_Id) return Elist_Id;
7077 -- For tagged types the candidate interpretations are found in
7078 -- the list of primitive operations of the type and its ancestors.
7079 -- For formal tagged types we have to find the operations declared
7080 -- in the same scope as the type (including in the generic formal
7081 -- part) because the type itself carries no primitive operations,
7082 -- except for formal derived types that inherit the operations of
7083 -- the parent and progenitors.
7084 -- If the context is a generic subprogram body, the generic formals
7085 -- are visible by name, but are not in the entity list of the
7086 -- subprogram because that list starts with the subprogram formals.
7087 -- We retrieve the candidate operations from the generic declaration.
7089 function Is_Private_Overriding (Op : Entity_Id) return Boolean;
7090 -- An operation that overrides an inherited operation in the private
7091 -- part of its package may be hidden, but if the inherited operation
7092 -- is visible a direct call to it will dispatch to the private one,
7093 -- which is therefore a valid candidate.
7095 function Valid_First_Argument_Of (Op : Entity_Id) return Boolean;
7096 -- Verify that the prefix, dereferenced if need be, is a valid
7097 -- controlling argument in a call to Op. The remaining actuals
7098 -- are checked in the subsequent call to Analyze_One_Call.
7100 ------------------------------
7101 -- Collect_Generic_Type_Ops --
7102 ------------------------------
7104 function Collect_Generic_Type_Ops (T : Entity_Id) return Elist_Id is
7105 Bas : constant Entity_Id := Base_Type (T);
7106 Candidates : constant Elist_Id := New_Elmt_List;
7110 procedure Check_Candidate;
7111 -- The operation is a candidate if its first parameter is a
7112 -- controlling operand of the desired type.
7114 -----------------------
7115 -- Check_Candidate; --
7116 -----------------------
7118 procedure Check_Candidate is
7120 Formal := First_Formal (Subp);
7123 and then Is_Controlling_Formal (Formal)
7125 (Base_Type (Etype (Formal)) = Bas
7127 (Is_Access_Type (Etype (Formal))
7128 and then Designated_Type (Etype (Formal)) = Bas))
7130 Append_Elmt (Subp, Candidates);
7132 end Check_Candidate;
7134 -- Start of processing for Collect_Generic_Type_Ops
7137 if Is_Derived_Type (T) then
7138 return Primitive_Operations (T);
7140 elsif Ekind_In (Scope (T), E_Procedure, E_Function) then
7142 -- Scan the list of generic formals to find subprograms
7143 -- that may have a first controlling formal of the type.
7145 if Nkind (Unit_Declaration_Node (Scope (T)))
7146 = N_Generic_Subprogram_Declaration
7153 First (Generic_Formal_Declarations
7154 (Unit_Declaration_Node (Scope (T))));
7155 while Present (Decl) loop
7156 if Nkind (Decl) in N_Formal_Subprogram_Declaration then
7157 Subp := Defining_Entity (Decl);
7168 -- Scan the list of entities declared in the same scope as
7169 -- the type. In general this will be an open scope, given that
7170 -- the call we are analyzing can only appear within a generic
7171 -- declaration or body (either the one that declares T, or a
7174 -- For a subtype representing a generic actual type, go to the
7177 if Is_Generic_Actual_Type (T) then
7178 Subp := First_Entity (Scope (Base_Type (T)));
7180 Subp := First_Entity (Scope (T));
7183 while Present (Subp) loop
7184 if Is_Overloadable (Subp) then
7193 end Collect_Generic_Type_Ops;
7195 ---------------------------
7196 -- Is_Private_Overriding --
7197 ---------------------------
7199 function Is_Private_Overriding (Op : Entity_Id) return Boolean is
7200 Visible_Op : constant Entity_Id := Homonym (Op);
7203 return Present (Visible_Op)
7204 and then Scope (Op) = Scope (Visible_Op)
7205 and then not Comes_From_Source (Visible_Op)
7206 and then Alias (Visible_Op) = Op
7207 and then not Is_Hidden (Visible_Op);
7208 end Is_Private_Overriding;
7210 -----------------------------
7211 -- Valid_First_Argument_Of --
7212 -----------------------------
7214 function Valid_First_Argument_Of (Op : Entity_Id) return Boolean is
7215 Typ : Entity_Id := Etype (First_Formal (Op));
7218 if Is_Concurrent_Type (Typ)
7219 and then Present (Corresponding_Record_Type (Typ))
7221 Typ := Corresponding_Record_Type (Typ);
7224 -- Simple case. Object may be a subtype of the tagged type or
7225 -- may be the corresponding record of a synchronized type.
7227 return Obj_Type = Typ
7228 or else Base_Type (Obj_Type) = Typ
7229 or else Corr_Type = Typ
7231 -- Prefix can be dereferenced
7234 (Is_Access_Type (Corr_Type)
7235 and then Designated_Type (Corr_Type) = Typ)
7237 -- Formal is an access parameter, for which the object
7238 -- can provide an access.
7241 (Ekind (Typ) = E_Anonymous_Access_Type
7243 Base_Type (Designated_Type (Typ)) = Base_Type (Corr_Type));
7244 end Valid_First_Argument_Of;
7246 -- Start of processing for Try_Primitive_Operation
7249 -- Look for subprograms in the list of primitive operations. The name
7250 -- must be identical, and the kind of call indicates the expected
7251 -- kind of operation (function or procedure). If the type is a
7252 -- (tagged) synchronized type, the primitive ops are attached to the
7253 -- corresponding record (base) type.
7255 if Is_Concurrent_Type (Obj_Type) then
7256 if Present (Corresponding_Record_Type (Obj_Type)) then
7257 Corr_Type := Base_Type (Corresponding_Record_Type (Obj_Type));
7258 Elmt := First_Elmt (Primitive_Operations (Corr_Type));
7260 Corr_Type := Obj_Type;
7261 Elmt := First_Elmt (Collect_Generic_Type_Ops (Obj_Type));
7264 elsif not Is_Generic_Type (Obj_Type) then
7265 Corr_Type := Obj_Type;
7266 Elmt := First_Elmt (Primitive_Operations (Obj_Type));
7269 Corr_Type := Obj_Type;
7270 Elmt := First_Elmt (Collect_Generic_Type_Ops (Obj_Type));
7273 while Present (Elmt) loop
7274 Prim_Op := Node (Elmt);
7276 if Chars (Prim_Op) = Chars (Subprog)
7277 and then Present (First_Formal (Prim_Op))
7278 and then Valid_First_Argument_Of (Prim_Op)
7280 (Nkind (Call_Node) = N_Function_Call)
7281 = (Ekind (Prim_Op) = E_Function)
7283 -- Ada 2005 (AI-251): If this primitive operation corresponds
7284 -- with an immediate ancestor interface there is no need to add
7285 -- it to the list of interpretations; the corresponding aliased
7286 -- primitive is also in this list of primitive operations and
7287 -- will be used instead.
7289 if (Present (Interface_Alias (Prim_Op))
7290 and then Is_Ancestor (Find_Dispatching_Type
7291 (Alias (Prim_Op)), Corr_Type))
7293 -- Do not consider hidden primitives unless the type is in an
7294 -- open scope or we are within an instance, where visibility
7295 -- is known to be correct, or else if this is an overriding
7296 -- operation in the private part for an inherited operation.
7298 or else (Is_Hidden (Prim_Op)
7299 and then not Is_Immediately_Visible (Obj_Type)
7300 and then not In_Instance
7301 and then not Is_Private_Overriding (Prim_Op))
7306 Set_Etype (Call_Node, Any_Type);
7307 Set_Is_Overloaded (Call_Node, False);
7309 if No (Matching_Op) then
7310 Prim_Op_Ref := New_Reference_To (Prim_Op, Sloc (Subprog));
7311 Candidate := Prim_Op;
7313 Set_Parent (Call_Node, Parent (Node_To_Replace));
7315 Set_Name (Call_Node, Prim_Op_Ref);
7321 Report => Report_Error,
7323 Skip_First => True);
7325 Matching_Op := Valid_Candidate (Success, Call_Node, Prim_Op);
7327 -- More than one interpretation, collect for subsequent
7328 -- disambiguation. If this is a procedure call and there
7329 -- is another match, report ambiguity now.
7335 Report => Report_Error,
7337 Skip_First => True);
7339 if Present (Valid_Candidate (Success, Call_Node, Prim_Op))
7340 and then Nkind (Call_Node) /= N_Function_Call
7342 Error_Msg_NE ("ambiguous call to&", N, Prim_Op);
7343 Report_Ambiguity (Matching_Op);
7344 Report_Ambiguity (Prim_Op);
7354 if Present (Matching_Op) then
7355 Set_Etype (Call_Node, Etype (Matching_Op));
7358 return Present (Matching_Op);
7359 end Try_Primitive_Operation;
7361 -- Start of processing for Try_Object_Operation
7364 Analyze_Expression (Obj);
7366 -- Analyze the actuals if node is known to be a subprogram call
7368 if Is_Subprg_Call and then N = Name (Parent (N)) then
7369 Actual := First (Parameter_Associations (Parent (N)));
7370 while Present (Actual) loop
7371 Analyze_Expression (Actual);
7376 -- Build a subprogram call node, using a copy of Obj as its first
7377 -- actual. This is a placeholder, to be replaced by an explicit
7378 -- dereference when needed.
7380 Transform_Object_Operation
7381 (Call_Node => New_Call_Node,
7382 Node_To_Replace => Node_To_Replace);
7384 Set_Etype (New_Call_Node, Any_Type);
7385 Set_Etype (Subprog, Any_Type);
7386 Set_Parent (New_Call_Node, Parent (Node_To_Replace));
7388 if not Is_Overloaded (Obj) then
7389 Try_One_Prefix_Interpretation (Obj_Type);
7396 Get_First_Interp (Obj, I, It);
7397 while Present (It.Nam) loop
7398 Try_One_Prefix_Interpretation (It.Typ);
7399 Get_Next_Interp (I, It);
7404 if Etype (New_Call_Node) /= Any_Type then
7405 Complete_Object_Operation
7406 (Call_Node => New_Call_Node,
7407 Node_To_Replace => Node_To_Replace);
7410 elsif Present (Candidate) then
7412 -- The argument list is not type correct. Re-analyze with error
7413 -- reporting enabled, and use one of the possible candidates.
7414 -- In All_Errors_Mode, re-analyze all failed interpretations.
7416 if All_Errors_Mode then
7417 Report_Error := True;
7418 if Try_Primitive_Operation
7419 (Call_Node => New_Call_Node,
7420 Node_To_Replace => Node_To_Replace)
7423 Try_Class_Wide_Operation
7424 (Call_Node => New_Call_Node,
7425 Node_To_Replace => Node_To_Replace)
7432 (N => New_Call_Node,
7436 Skip_First => True);
7439 -- No need for further errors
7444 -- There was no candidate operation, so report it as an error
7445 -- in the caller: Analyze_Selected_Component.
7449 end Try_Object_Operation;
7455 procedure wpo (T : Entity_Id) is
7460 if not Is_Tagged_Type (T) then
7464 E := First_Elmt (Primitive_Operations (Base_Type (T)));
7465 while Present (E) loop
7467 Write_Int (Int (Op));
7468 Write_Str (" === ");
7469 Write_Name (Chars (Op));
7471 Write_Name (Chars (Scope (Op)));