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 Mark_Non_ALFA_Subprogram;
355 if No (Etype (N)) then
356 Set_Etype (N, Any_Composite);
358 end Analyze_Aggregate;
360 -----------------------
361 -- Analyze_Allocator --
362 -----------------------
364 procedure Analyze_Allocator (N : Node_Id) is
365 Loc : constant Source_Ptr := Sloc (N);
366 Sav_Errs : constant Nat := Serious_Errors_Detected;
367 E : Node_Id := Expression (N);
368 Acc_Type : Entity_Id;
374 Mark_Non_ALFA_Subprogram;
375 Check_SPARK_Restriction ("allocator is not allowed", N);
377 -- Deal with allocator restrictions
379 -- In accordance with H.4(7), the No_Allocators restriction only applies
380 -- to user-written allocators. The same consideration applies to the
381 -- No_Allocators_Before_Elaboration restriction.
383 if Comes_From_Source (N) then
384 Check_Restriction (No_Allocators, N);
386 -- Processing for No_Allocators_After_Elaboration, loop to look at
387 -- enclosing context, checking task case and main subprogram case.
391 while Present (P) loop
393 -- In both cases we need a handled sequence of statements, where
394 -- the occurrence of the allocator is within the statements.
396 if Nkind (P) = N_Handled_Sequence_Of_Statements
397 and then Is_List_Member (C)
398 and then List_Containing (C) = Statements (P)
400 -- Check for allocator within task body, this is a definite
401 -- violation of No_Allocators_After_Elaboration we can detect.
403 if Nkind (Original_Node (Parent (P))) = N_Task_Body then
404 Check_Restriction (No_Allocators_After_Elaboration, N);
408 -- The other case is appearance in a subprogram body. This may
409 -- be a violation if this is a library level subprogram, and it
410 -- turns out to be used as the main program, but only the
411 -- binder knows that, so just record the occurrence.
413 if Nkind (Original_Node (Parent (P))) = N_Subprogram_Body
414 and then Nkind (Parent (Parent (P))) = N_Compilation_Unit
416 Set_Has_Allocator (Current_Sem_Unit);
425 -- Analyze the allocator
427 if Nkind (E) = N_Qualified_Expression then
428 Acc_Type := Create_Itype (E_Allocator_Type, N);
429 Set_Etype (Acc_Type, Acc_Type);
430 Find_Type (Subtype_Mark (E));
432 -- Analyze the qualified expression, and apply the name resolution
433 -- rule given in 4.7 (3).
436 Type_Id := Etype (E);
437 Set_Directly_Designated_Type (Acc_Type, Type_Id);
439 Resolve (Expression (E), Type_Id);
441 if Is_Limited_Type (Type_Id)
442 and then Comes_From_Source (N)
443 and then not In_Instance_Body
445 if not OK_For_Limited_Init (Type_Id, Expression (E)) then
446 Error_Msg_N ("initialization not allowed for limited types", N);
447 Explain_Limited_Type (Type_Id, N);
451 -- A qualified expression requires an exact match of the type,
452 -- class-wide matching is not allowed.
454 -- if Is_Class_Wide_Type (Type_Id)
455 -- and then Base_Type
456 -- (Etype (Expression (E))) /= Base_Type (Type_Id)
458 -- Wrong_Type (Expression (E), Type_Id);
461 Check_Non_Static_Context (Expression (E));
463 -- We don't analyze the qualified expression itself because it's
464 -- part of the allocator
466 Set_Etype (E, Type_Id);
468 -- Case where allocator has a subtype indication
473 Base_Typ : Entity_Id;
476 -- If the allocator includes a N_Subtype_Indication then a
477 -- constraint is present, otherwise the node is a subtype mark.
478 -- Introduce an explicit subtype declaration into the tree
479 -- defining some anonymous subtype and rewrite the allocator to
480 -- use this subtype rather than the subtype indication.
482 -- It is important to introduce the explicit subtype declaration
483 -- so that the bounds of the subtype indication are attached to
484 -- the tree in case the allocator is inside a generic unit.
486 if Nkind (E) = N_Subtype_Indication then
488 -- A constraint is only allowed for a composite type in Ada
489 -- 95. In Ada 83, a constraint is also allowed for an
490 -- access-to-composite type, but the constraint is ignored.
492 Find_Type (Subtype_Mark (E));
493 Base_Typ := Entity (Subtype_Mark (E));
495 if Is_Elementary_Type (Base_Typ) then
496 if not (Ada_Version = Ada_83
497 and then Is_Access_Type (Base_Typ))
499 Error_Msg_N ("constraint not allowed here", E);
501 if Nkind (Constraint (E)) =
502 N_Index_Or_Discriminant_Constraint
504 Error_Msg_N -- CODEFIX
505 ("\if qualified expression was meant, " &
506 "use apostrophe", Constraint (E));
510 -- Get rid of the bogus constraint:
512 Rewrite (E, New_Copy_Tree (Subtype_Mark (E)));
513 Analyze_Allocator (N);
516 -- Ada 2005, AI-363: if the designated type has a constrained
517 -- partial view, it cannot receive a discriminant constraint,
518 -- and the allocated object is unconstrained.
520 elsif Ada_Version >= Ada_2005
521 and then Has_Constrained_Partial_View (Base_Typ)
524 ("constraint no allowed when type " &
525 "has a constrained partial view", Constraint (E));
528 if Expander_Active then
529 Def_Id := Make_Temporary (Loc, 'S');
532 Make_Subtype_Declaration (Loc,
533 Defining_Identifier => Def_Id,
534 Subtype_Indication => Relocate_Node (E)));
536 if Sav_Errs /= Serious_Errors_Detected
537 and then Nkind (Constraint (E)) =
538 N_Index_Or_Discriminant_Constraint
540 Error_Msg_N -- CODEFIX
541 ("if qualified expression was meant, " &
542 "use apostrophe!", Constraint (E));
545 E := New_Occurrence_Of (Def_Id, Loc);
546 Rewrite (Expression (N), E);
550 Type_Id := Process_Subtype (E, N);
551 Acc_Type := Create_Itype (E_Allocator_Type, N);
552 Set_Etype (Acc_Type, Acc_Type);
553 Set_Directly_Designated_Type (Acc_Type, Type_Id);
554 Check_Fully_Declared (Type_Id, N);
556 -- Ada 2005 (AI-231): If the designated type is itself an access
557 -- type that excludes null, its default initialization will
558 -- be a null object, and we can insert an unconditional raise
559 -- before the allocator.
561 -- Ada 2012 (AI-104): A not null indication here is altogether
564 if Can_Never_Be_Null (Type_Id) then
566 Not_Null_Check : constant Node_Id :=
567 Make_Raise_Constraint_Error (Sloc (E),
568 Reason => CE_Null_Not_Allowed);
571 if Ada_Version >= Ada_2012 then
573 ("an uninitialized allocator cannot have"
574 & " a null exclusion", N);
576 elsif Expander_Active then
577 Insert_Action (N, Not_Null_Check);
578 Analyze (Not_Null_Check);
581 Error_Msg_N ("null value not allowed here?", E);
586 -- Check restriction against dynamically allocated protected
587 -- objects. Note that when limited aggregates are supported,
588 -- a similar test should be applied to an allocator with a
589 -- qualified expression ???
591 if Is_Protected_Type (Type_Id) then
592 Check_Restriction (No_Protected_Type_Allocators, N);
595 -- Check for missing initialization. Skip this check if we already
596 -- had errors on analyzing the allocator, since in that case these
597 -- are probably cascaded errors.
599 if Is_Indefinite_Subtype (Type_Id)
600 and then Serious_Errors_Detected = Sav_Errs
602 if Is_Class_Wide_Type (Type_Id) then
604 ("initialization required in class-wide allocation", N);
606 if Ada_Version < Ada_2005
607 and then Is_Limited_Type (Type_Id)
609 Error_Msg_N ("unconstrained allocation not allowed", N);
611 if Is_Array_Type (Type_Id) then
613 ("\constraint with array bounds required", N);
615 elsif Has_Unknown_Discriminants (Type_Id) then
618 else pragma Assert (Has_Discriminants (Type_Id));
620 ("\constraint with discriminant values required", N);
623 -- Limited Ada 2005 and general non-limited case
627 ("uninitialized unconstrained allocation not allowed",
630 if Is_Array_Type (Type_Id) then
632 ("\qualified expression or constraint with " &
633 "array bounds required", N);
635 elsif Has_Unknown_Discriminants (Type_Id) then
636 Error_Msg_N ("\qualified expression required", N);
638 else pragma Assert (Has_Discriminants (Type_Id));
640 ("\qualified expression or constraint with " &
641 "discriminant values required", N);
649 if Is_Abstract_Type (Type_Id) then
650 Error_Msg_N ("cannot allocate abstract object", E);
653 if Has_Task (Designated_Type (Acc_Type)) then
654 Check_Restriction (No_Tasking, N);
655 Check_Restriction (Max_Tasks, N);
656 Check_Restriction (No_Task_Allocators, N);
658 -- Check that an allocator with task parts isn't for a nested access
659 -- type when restriction No_Task_Hierarchy applies.
661 if not Is_Library_Level_Entity (Acc_Type) then
662 Check_Restriction (No_Task_Hierarchy, N);
666 -- Check that an allocator of a nested access type doesn't create a
667 -- protected object when restriction No_Local_Protected_Objects applies.
668 -- We don't have an equivalent to Has_Task for protected types, so only
669 -- cases where the designated type itself is a protected type are
670 -- currently checked. ???
672 if Is_Protected_Type (Designated_Type (Acc_Type))
673 and then not Is_Library_Level_Entity (Acc_Type)
675 Check_Restriction (No_Local_Protected_Objects, N);
678 -- If the No_Streams restriction is set, check that the type of the
679 -- object is not, and does not contain, any subtype derived from
680 -- Ada.Streams.Root_Stream_Type. Note that we guard the call to
681 -- Has_Stream just for efficiency reasons. There is no point in
682 -- spending time on a Has_Stream check if the restriction is not set.
684 if Restriction_Check_Required (No_Streams) then
685 if Has_Stream (Designated_Type (Acc_Type)) then
686 Check_Restriction (No_Streams, N);
690 Set_Etype (N, Acc_Type);
692 if not Is_Library_Level_Entity (Acc_Type) then
693 Check_Restriction (No_Local_Allocators, N);
696 if Serious_Errors_Detected > Sav_Errs then
697 Set_Error_Posted (N);
698 Set_Etype (N, Any_Type);
700 end Analyze_Allocator;
702 ---------------------------
703 -- Analyze_Arithmetic_Op --
704 ---------------------------
706 procedure Analyze_Arithmetic_Op (N : Node_Id) is
707 L : constant Node_Id := Left_Opnd (N);
708 R : constant Node_Id := Right_Opnd (N);
712 Candidate_Type := Empty;
713 Analyze_Expression (L);
714 Analyze_Expression (R);
716 -- If the entity is already set, the node is the instantiation of a
717 -- generic node with a non-local reference, or was manufactured by a
718 -- call to Make_Op_xxx. In either case the entity is known to be valid,
719 -- and we do not need to collect interpretations, instead we just get
720 -- the single possible interpretation.
724 if Present (Op_Id) then
725 if Ekind (Op_Id) = E_Operator then
727 if Nkind_In (N, N_Op_Divide, N_Op_Mod, N_Op_Multiply, N_Op_Rem)
728 and then Treat_Fixed_As_Integer (N)
732 Set_Etype (N, Any_Type);
733 Find_Arithmetic_Types (L, R, Op_Id, N);
737 Set_Etype (N, Any_Type);
738 Add_One_Interp (N, Op_Id, Etype (Op_Id));
741 -- Entity is not already set, so we do need to collect interpretations
744 Op_Id := Get_Name_Entity_Id (Chars (N));
745 Set_Etype (N, Any_Type);
747 while Present (Op_Id) loop
748 if Ekind (Op_Id) = E_Operator
749 and then Present (Next_Entity (First_Entity (Op_Id)))
751 Find_Arithmetic_Types (L, R, Op_Id, N);
753 -- The following may seem superfluous, because an operator cannot
754 -- be generic, but this ignores the cleverness of the author of
757 elsif Is_Overloadable (Op_Id) then
758 Analyze_User_Defined_Binary_Op (N, Op_Id);
761 Op_Id := Homonym (Op_Id);
766 end Analyze_Arithmetic_Op;
772 -- Function, procedure, and entry calls are checked here. The Name in
773 -- the call may be overloaded. The actuals have been analyzed and may
774 -- themselves be overloaded. On exit from this procedure, the node N
775 -- may have zero, one or more interpretations. In the first case an
776 -- error message is produced. In the last case, the node is flagged
777 -- as overloaded and the interpretations are collected in All_Interp.
779 -- If the name is an Access_To_Subprogram, it cannot be overloaded, but
780 -- the type-checking is similar to that of other calls.
782 procedure Analyze_Call (N : Node_Id) is
783 Actuals : constant List_Id := Parameter_Associations (N);
788 Success : Boolean := False;
790 Deref : Boolean := False;
791 -- Flag indicates whether an interpretation of the prefix is a
792 -- parameterless call that returns an access_to_subprogram.
794 procedure Check_Mixed_Parameter_And_Named_Associations;
795 -- Check that parameter and named associations are not mixed. This is
796 -- a restriction in SPARK mode.
798 function Name_Denotes_Function return Boolean;
799 -- If the type of the name is an access to subprogram, this may be the
800 -- type of a name, or the return type of the function being called. If
801 -- the name is not an entity then it can denote a protected function.
802 -- Until we distinguish Etype from Return_Type, we must use this routine
803 -- to resolve the meaning of the name in the call.
805 procedure No_Interpretation;
806 -- Output error message when no valid interpretation exists
808 --------------------------------------------------
809 -- Check_Mixed_Parameter_And_Named_Associations --
810 --------------------------------------------------
812 procedure Check_Mixed_Parameter_And_Named_Associations is
814 Named_Seen : Boolean;
819 Actual := First (Actuals);
820 while Present (Actual) loop
821 case Nkind (Actual) is
822 when N_Parameter_Association =>
824 Check_SPARK_Restriction
825 ("named association cannot follow positional one",
835 end Check_Mixed_Parameter_And_Named_Associations;
837 ---------------------------
838 -- Name_Denotes_Function --
839 ---------------------------
841 function Name_Denotes_Function return Boolean is
843 if Is_Entity_Name (Nam) then
844 return Ekind (Entity (Nam)) = E_Function;
846 elsif Nkind (Nam) = N_Selected_Component then
847 return Ekind (Entity (Selector_Name (Nam))) = E_Function;
852 end Name_Denotes_Function;
854 -----------------------
855 -- No_Interpretation --
856 -----------------------
858 procedure No_Interpretation is
859 L : constant Boolean := Is_List_Member (N);
860 K : constant Node_Kind := Nkind (Parent (N));
863 -- If the node is in a list whose parent is not an expression then it
864 -- must be an attempted procedure call.
866 if L and then K not in N_Subexpr then
867 if Ekind (Entity (Nam)) = E_Generic_Procedure then
869 ("must instantiate generic procedure& before call",
873 ("procedure or entry name expected", Nam);
876 -- Check for tasking cases where only an entry call will do
879 and then Nkind_In (K, N_Entry_Call_Alternative,
880 N_Triggering_Alternative)
882 Error_Msg_N ("entry name expected", Nam);
884 -- Otherwise give general error message
887 Error_Msg_N ("invalid prefix in call", Nam);
889 end No_Interpretation;
891 -- Start of processing for Analyze_Call
894 if SPARK_Mode or else Restriction_Check_Required (SPARK) then
895 Check_Mixed_Parameter_And_Named_Associations;
898 -- Initialize the type of the result of the call to the error type,
899 -- which will be reset if the type is successfully resolved.
901 Set_Etype (N, Any_Type);
905 if not Is_Overloaded (Nam) then
907 -- Only one interpretation to check
909 if Ekind (Etype (Nam)) = E_Subprogram_Type then
910 Nam_Ent := Etype (Nam);
912 -- If the prefix is an access_to_subprogram, this may be an indirect
913 -- call. This is the case if the name in the call is not an entity
914 -- name, or if it is a function name in the context of a procedure
915 -- call. In this latter case, we have a call to a parameterless
916 -- function that returns a pointer_to_procedure which is the entity
917 -- being called. Finally, F (X) may be a call to a parameterless
918 -- function that returns a pointer to a function with parameters.
920 elsif Is_Access_Type (Etype (Nam))
921 and then Ekind (Designated_Type (Etype (Nam))) = E_Subprogram_Type
923 (not Name_Denotes_Function
924 or else Nkind (N) = N_Procedure_Call_Statement
926 (Nkind (Parent (N)) /= N_Explicit_Dereference
927 and then Is_Entity_Name (Nam)
928 and then No (First_Formal (Entity (Nam)))
929 and then Present (Actuals)))
931 Nam_Ent := Designated_Type (Etype (Nam));
932 Insert_Explicit_Dereference (Nam);
934 -- Selected component case. Simple entry or protected operation,
935 -- where the entry name is given by the selector name.
937 elsif Nkind (Nam) = N_Selected_Component then
938 Nam_Ent := Entity (Selector_Name (Nam));
940 if not Ekind_In (Nam_Ent, E_Entry,
945 Error_Msg_N ("name in call is not a callable entity", Nam);
946 Set_Etype (N, Any_Type);
950 -- If the name is an Indexed component, it can be a call to a member
951 -- of an entry family. The prefix must be a selected component whose
952 -- selector is the entry. Analyze_Procedure_Call normalizes several
953 -- kinds of call into this form.
955 elsif Nkind (Nam) = N_Indexed_Component then
956 if Nkind (Prefix (Nam)) = N_Selected_Component then
957 Nam_Ent := Entity (Selector_Name (Prefix (Nam)));
959 Error_Msg_N ("name in call is not a callable entity", Nam);
960 Set_Etype (N, Any_Type);
964 elsif not Is_Entity_Name (Nam) then
965 Error_Msg_N ("name in call is not a callable entity", Nam);
966 Set_Etype (N, Any_Type);
970 Nam_Ent := Entity (Nam);
972 -- If no interpretations, give error message
974 if not Is_Overloadable (Nam_Ent) then
980 -- Operations generated for RACW stub types are called only through
981 -- dispatching, and can never be the static interpretation of a call.
983 if Is_RACW_Stub_Type_Operation (Nam_Ent) then
988 -- If this is an indirect call, or the subprogram called is not in
989 -- ALFA, then the call is not in ALFA.
991 if not Is_Subprogram (Nam_Ent)
992 or else not Is_In_ALFA (Nam_Ent)
994 Mark_Non_ALFA_Subprogram;
997 Analyze_One_Call (N, Nam_Ent, True, Success);
999 -- If this is an indirect call, the return type of the access_to
1000 -- subprogram may be an incomplete type. At the point of the call,
1001 -- use the full type if available, and at the same time update the
1002 -- return type of the access_to_subprogram.
1005 and then Nkind (Nam) = N_Explicit_Dereference
1006 and then Ekind (Etype (N)) = E_Incomplete_Type
1007 and then Present (Full_View (Etype (N)))
1009 Set_Etype (N, Full_View (Etype (N)));
1010 Set_Etype (Nam_Ent, Etype (N));
1014 -- An overloaded selected component must denote overloaded operations
1015 -- of a concurrent type. The interpretations are attached to the
1016 -- simple name of those operations.
1018 if Nkind (Nam) = N_Selected_Component then
1019 Nam := Selector_Name (Nam);
1022 Get_First_Interp (Nam, X, It);
1024 while Present (It.Nam) loop
1028 -- Name may be call that returns an access to subprogram, or more
1029 -- generally an overloaded expression one of whose interpretations
1030 -- yields an access to subprogram. If the name is an entity, we do
1031 -- not dereference, because the node is a call that returns the
1032 -- access type: note difference between f(x), where the call may
1033 -- return an access subprogram type, and f(x)(y), where the type
1034 -- returned by the call to f is implicitly dereferenced to analyze
1037 if Is_Access_Type (Nam_Ent) then
1038 Nam_Ent := Designated_Type (Nam_Ent);
1040 elsif Is_Access_Type (Etype (Nam_Ent))
1042 (not Is_Entity_Name (Nam)
1043 or else Nkind (N) = N_Procedure_Call_Statement)
1044 and then Ekind (Designated_Type (Etype (Nam_Ent)))
1047 Nam_Ent := Designated_Type (Etype (Nam_Ent));
1049 if Is_Entity_Name (Nam) then
1054 -- If the call has been rewritten from a prefixed call, the first
1055 -- parameter has been analyzed, but may need a subsequent
1056 -- dereference, so skip its analysis now.
1058 if N /= Original_Node (N)
1059 and then Nkind (Original_Node (N)) = Nkind (N)
1060 and then Nkind (Name (N)) /= Nkind (Name (Original_Node (N)))
1061 and then Present (Parameter_Associations (N))
1062 and then Present (Etype (First (Parameter_Associations (N))))
1065 (N, Nam_Ent, False, Success, Skip_First => True);
1067 Analyze_One_Call (N, Nam_Ent, False, Success);
1070 -- If the interpretation succeeds, mark the proper type of the
1071 -- prefix (any valid candidate will do). If not, remove the
1072 -- candidate interpretation. This only needs to be done for
1073 -- overloaded protected operations, for other entities disambi-
1074 -- guation is done directly in Resolve.
1078 and then Nkind (Parent (N)) /= N_Explicit_Dereference
1080 Set_Entity (Nam, It.Nam);
1081 Insert_Explicit_Dereference (Nam);
1082 Set_Etype (Nam, Nam_Ent);
1085 Set_Etype (Nam, It.Typ);
1088 elsif Nkind_In (Name (N), N_Selected_Component,
1094 Get_Next_Interp (X, It);
1097 -- If the name is the result of a function call, it can only
1098 -- be a call to a function returning an access to subprogram.
1099 -- Insert explicit dereference.
1101 if Nkind (Nam) = N_Function_Call then
1102 Insert_Explicit_Dereference (Nam);
1105 if Etype (N) = Any_Type then
1107 -- None of the interpretations is compatible with the actuals
1109 Diagnose_Call (N, Nam);
1111 -- Special checks for uninstantiated put routines
1113 if Nkind (N) = N_Procedure_Call_Statement
1114 and then Is_Entity_Name (Nam)
1115 and then Chars (Nam) = Name_Put
1116 and then List_Length (Actuals) = 1
1119 Arg : constant Node_Id := First (Actuals);
1123 if Nkind (Arg) = N_Parameter_Association then
1124 Typ := Etype (Explicit_Actual_Parameter (Arg));
1129 if Is_Signed_Integer_Type (Typ) then
1131 ("possible missing instantiation of " &
1132 "'Text_'I'O.'Integer_'I'O!", Nam);
1134 elsif Is_Modular_Integer_Type (Typ) then
1136 ("possible missing instantiation of " &
1137 "'Text_'I'O.'Modular_'I'O!", Nam);
1139 elsif Is_Floating_Point_Type (Typ) then
1141 ("possible missing instantiation of " &
1142 "'Text_'I'O.'Float_'I'O!", Nam);
1144 elsif Is_Ordinary_Fixed_Point_Type (Typ) then
1146 ("possible missing instantiation of " &
1147 "'Text_'I'O.'Fixed_'I'O!", Nam);
1149 elsif Is_Decimal_Fixed_Point_Type (Typ) then
1151 ("possible missing instantiation of " &
1152 "'Text_'I'O.'Decimal_'I'O!", Nam);
1154 elsif Is_Enumeration_Type (Typ) then
1156 ("possible missing instantiation of " &
1157 "'Text_'I'O.'Enumeration_'I'O!", Nam);
1162 elsif not Is_Overloaded (N)
1163 and then Is_Entity_Name (Nam)
1165 -- Resolution yields a single interpretation. Verify that the
1166 -- reference has capitalization consistent with the declaration.
1168 Set_Entity_With_Style_Check (Nam, Entity (Nam));
1169 Generate_Reference (Entity (Nam), Nam);
1171 Set_Etype (Nam, Etype (Entity (Nam)));
1173 Remove_Abstract_Operations (N);
1180 -----------------------------
1181 -- Analyze_Case_Expression --
1182 -----------------------------
1184 procedure Analyze_Case_Expression (N : Node_Id) is
1185 Expr : constant Node_Id := Expression (N);
1186 FirstX : constant Node_Id := Expression (First (Alternatives (N)));
1188 Exp_Type : Entity_Id;
1189 Exp_Btype : Entity_Id;
1191 Dont_Care : Boolean;
1192 Others_Present : Boolean;
1194 procedure Non_Static_Choice_Error (Choice : Node_Id);
1195 -- Error routine invoked by the generic instantiation below when
1196 -- the case expression has a non static choice.
1198 package Case_Choices_Processing is new
1199 Generic_Choices_Processing
1200 (Get_Alternatives => Alternatives,
1201 Get_Choices => Discrete_Choices,
1202 Process_Empty_Choice => No_OP,
1203 Process_Non_Static_Choice => Non_Static_Choice_Error,
1204 Process_Associated_Node => No_OP);
1205 use Case_Choices_Processing;
1207 -----------------------------
1208 -- Non_Static_Choice_Error --
1209 -----------------------------
1211 procedure Non_Static_Choice_Error (Choice : Node_Id) is
1213 Flag_Non_Static_Expr
1214 ("choice given in case expression is not static!", Choice);
1215 end Non_Static_Choice_Error;
1217 -- Start of processing for Analyze_Case_Expression
1220 if Comes_From_Source (N) then
1221 Check_Compiler_Unit (N);
1224 Analyze_And_Resolve (Expr, Any_Discrete);
1225 Check_Unset_Reference (Expr);
1226 Exp_Type := Etype (Expr);
1227 Exp_Btype := Base_Type (Exp_Type);
1229 Alt := First (Alternatives (N));
1230 while Present (Alt) loop
1231 Analyze (Expression (Alt));
1235 if not Is_Overloaded (FirstX) then
1236 Set_Etype (N, Etype (FirstX));
1244 Set_Etype (N, Any_Type);
1246 Get_First_Interp (FirstX, I, It);
1247 while Present (It.Nam) loop
1249 -- For each interpretation of the first expression, we only
1250 -- add the interpretation if every other expression in the
1251 -- case expression alternatives has a compatible type.
1253 Alt := Next (First (Alternatives (N)));
1254 while Present (Alt) loop
1255 exit when not Has_Compatible_Type (Expression (Alt), It.Typ);
1260 Add_One_Interp (N, It.Typ, It.Typ);
1263 Get_Next_Interp (I, It);
1268 Exp_Btype := Base_Type (Exp_Type);
1270 -- The expression must be of a discrete type which must be determinable
1271 -- independently of the context in which the expression occurs, but
1272 -- using the fact that the expression must be of a discrete type.
1273 -- Moreover, the type this expression must not be a character literal
1274 -- (which is always ambiguous).
1276 -- If error already reported by Resolve, nothing more to do
1278 if Exp_Btype = Any_Discrete
1279 or else Exp_Btype = Any_Type
1283 elsif Exp_Btype = Any_Character then
1285 ("character literal as case expression is ambiguous", Expr);
1289 -- If the case expression is a formal object of mode in out, then
1290 -- treat it as having a nonstatic subtype by forcing use of the base
1291 -- type (which has to get passed to Check_Case_Choices below). Also
1292 -- use base type when the case expression is parenthesized.
1294 if Paren_Count (Expr) > 0
1295 or else (Is_Entity_Name (Expr)
1296 and then Ekind (Entity (Expr)) = E_Generic_In_Out_Parameter)
1298 Exp_Type := Exp_Btype;
1301 -- Call instantiated Analyze_Choices which does the rest of the work
1303 Analyze_Choices (N, Exp_Type, Dont_Care, Others_Present);
1305 if Exp_Type = Universal_Integer and then not Others_Present then
1307 ("case on universal integer requires OTHERS choice", Expr);
1309 end Analyze_Case_Expression;
1311 ---------------------------
1312 -- Analyze_Comparison_Op --
1313 ---------------------------
1315 procedure Analyze_Comparison_Op (N : Node_Id) is
1316 L : constant Node_Id := Left_Opnd (N);
1317 R : constant Node_Id := Right_Opnd (N);
1318 Op_Id : Entity_Id := Entity (N);
1321 Set_Etype (N, Any_Type);
1322 Candidate_Type := Empty;
1324 Analyze_Expression (L);
1325 Analyze_Expression (R);
1327 if Present (Op_Id) then
1328 if Ekind (Op_Id) = E_Operator then
1329 Find_Comparison_Types (L, R, Op_Id, N);
1331 Add_One_Interp (N, Op_Id, Etype (Op_Id));
1334 if Is_Overloaded (L) then
1335 Set_Etype (L, Intersect_Types (L, R));
1339 Op_Id := Get_Name_Entity_Id (Chars (N));
1340 while Present (Op_Id) loop
1341 if Ekind (Op_Id) = E_Operator then
1342 Find_Comparison_Types (L, R, Op_Id, N);
1344 Analyze_User_Defined_Binary_Op (N, Op_Id);
1347 Op_Id := Homonym (Op_Id);
1352 end Analyze_Comparison_Op;
1354 ---------------------------
1355 -- Analyze_Concatenation --
1356 ---------------------------
1358 procedure Analyze_Concatenation (N : Node_Id) is
1360 -- We wish to avoid deep recursion, because concatenations are often
1361 -- deeply nested, as in A&B&...&Z. Therefore, we walk down the left
1362 -- operands nonrecursively until we find something that is not a
1363 -- concatenation (A in this case), or has already been analyzed. We
1364 -- analyze that, and then walk back up the tree following Parent
1365 -- pointers, calling Analyze_Concatenation_Rest to do the rest of the
1366 -- work at each level. The Parent pointers allow us to avoid recursion,
1367 -- and thus avoid running out of memory.
1373 Mark_Non_ALFA_Subprogram;
1375 Candidate_Type := Empty;
1377 -- The following code is equivalent to:
1379 -- Set_Etype (N, Any_Type);
1380 -- Analyze_Expression (Left_Opnd (N));
1381 -- Analyze_Concatenation_Rest (N);
1383 -- where the Analyze_Expression call recurses back here if the left
1384 -- operand is a concatenation.
1386 -- Walk down left operands
1389 Set_Etype (NN, Any_Type);
1390 L := Left_Opnd (NN);
1391 exit when Nkind (L) /= N_Op_Concat or else Analyzed (L);
1395 -- Now (given the above example) NN is A&B and L is A
1397 -- First analyze L ...
1399 Analyze_Expression (L);
1401 -- ... then walk NN back up until we reach N (where we started), calling
1402 -- Analyze_Concatenation_Rest along the way.
1405 Analyze_Concatenation_Rest (NN);
1409 end Analyze_Concatenation;
1411 --------------------------------
1412 -- Analyze_Concatenation_Rest --
1413 --------------------------------
1415 -- If the only one-dimensional array type in scope is String,
1416 -- this is the resulting type of the operation. Otherwise there
1417 -- will be a concatenation operation defined for each user-defined
1418 -- one-dimensional array.
1420 procedure Analyze_Concatenation_Rest (N : Node_Id) is
1421 L : constant Node_Id := Left_Opnd (N);
1422 R : constant Node_Id := Right_Opnd (N);
1423 Op_Id : Entity_Id := Entity (N);
1428 Analyze_Expression (R);
1430 -- If the entity is present, the node appears in an instance, and
1431 -- denotes a predefined concatenation operation. The resulting type is
1432 -- obtained from the arguments when possible. If the arguments are
1433 -- aggregates, the array type and the concatenation type must be
1436 if Present (Op_Id) then
1437 if Ekind (Op_Id) = E_Operator then
1438 LT := Base_Type (Etype (L));
1439 RT := Base_Type (Etype (R));
1441 if Is_Array_Type (LT)
1442 and then (RT = LT or else RT = Base_Type (Component_Type (LT)))
1444 Add_One_Interp (N, Op_Id, LT);
1446 elsif Is_Array_Type (RT)
1447 and then LT = Base_Type (Component_Type (RT))
1449 Add_One_Interp (N, Op_Id, RT);
1451 -- If one operand is a string type or a user-defined array type,
1452 -- and the other is a literal, result is of the specific type.
1455 (Root_Type (LT) = Standard_String
1456 or else Scope (LT) /= Standard_Standard)
1457 and then Etype (R) = Any_String
1459 Add_One_Interp (N, Op_Id, LT);
1462 (Root_Type (RT) = Standard_String
1463 or else Scope (RT) /= Standard_Standard)
1464 and then Etype (L) = Any_String
1466 Add_One_Interp (N, Op_Id, RT);
1468 elsif not Is_Generic_Type (Etype (Op_Id)) then
1469 Add_One_Interp (N, Op_Id, Etype (Op_Id));
1472 -- Type and its operations must be visible
1474 Set_Entity (N, Empty);
1475 Analyze_Concatenation (N);
1479 Add_One_Interp (N, Op_Id, Etype (Op_Id));
1483 Op_Id := Get_Name_Entity_Id (Name_Op_Concat);
1484 while Present (Op_Id) loop
1485 if Ekind (Op_Id) = E_Operator then
1487 -- Do not consider operators declared in dead code, they can
1488 -- not be part of the resolution.
1490 if Is_Eliminated (Op_Id) then
1493 Find_Concatenation_Types (L, R, Op_Id, N);
1497 Analyze_User_Defined_Binary_Op (N, Op_Id);
1500 Op_Id := Homonym (Op_Id);
1505 end Analyze_Concatenation_Rest;
1507 ------------------------------------
1508 -- Analyze_Conditional_Expression --
1509 ------------------------------------
1511 procedure Analyze_Conditional_Expression (N : Node_Id) is
1512 Condition : constant Node_Id := First (Expressions (N));
1513 Then_Expr : constant Node_Id := Next (Condition);
1514 Else_Expr : Node_Id;
1517 -- Defend against error of missing expressions from previous error
1519 if No (Then_Expr) then
1523 Check_SPARK_Restriction ("conditional expression is not allowed", N);
1525 Else_Expr := Next (Then_Expr);
1527 -- In ALFA, boolean conditional expressions are allowed:
1528 -- * if they have no ELSE part, in which case the expression is
1531 -- NOT Condition OR ELSE Then_Expr
1533 -- * in pre- and postconditions, where the Condition cannot have side-
1534 -- effects (in ALFA) and thus the expression is equivalent to
1536 -- (Condition AND THEN Then_Expr)
1537 -- and (NOT Condition AND THEN Then_Expr)
1539 -- Non-boolean conditional expressions are marked as not in ALFA during
1542 if Present (Else_Expr) and then not In_Pre_Post_Expression then
1543 Mark_Non_ALFA_Subprogram;
1546 if Comes_From_Source (N) then
1547 Check_Compiler_Unit (N);
1550 Analyze_Expression (Condition);
1551 Analyze_Expression (Then_Expr);
1553 if Present (Else_Expr) then
1554 Analyze_Expression (Else_Expr);
1557 -- If then expression not overloaded, then that decides the type
1559 if not Is_Overloaded (Then_Expr) then
1560 Set_Etype (N, Etype (Then_Expr));
1562 -- Case where then expression is overloaded
1570 Set_Etype (N, Any_Type);
1572 -- Shouldn't the following statement be down in the ELSE of the
1573 -- following loop? ???
1575 Get_First_Interp (Then_Expr, I, It);
1577 -- if no Else_Expression the conditional must be boolean
1579 if No (Else_Expr) then
1580 Set_Etype (N, Standard_Boolean);
1582 -- Else_Expression Present. For each possible intepretation of
1583 -- the Then_Expression, add it only if the Else_Expression has
1584 -- a compatible type.
1587 while Present (It.Nam) loop
1588 if Has_Compatible_Type (Else_Expr, It.Typ) then
1589 Add_One_Interp (N, It.Typ, It.Typ);
1592 Get_Next_Interp (I, It);
1597 end Analyze_Conditional_Expression;
1599 -------------------------
1600 -- Analyze_Equality_Op --
1601 -------------------------
1603 procedure Analyze_Equality_Op (N : Node_Id) is
1604 Loc : constant Source_Ptr := Sloc (N);
1605 L : constant Node_Id := Left_Opnd (N);
1606 R : constant Node_Id := Right_Opnd (N);
1610 Set_Etype (N, Any_Type);
1611 Candidate_Type := Empty;
1613 Analyze_Expression (L);
1614 Analyze_Expression (R);
1616 -- If the entity is set, the node is a generic instance with a non-local
1617 -- reference to the predefined operator or to a user-defined function.
1618 -- It can also be an inequality that is expanded into the negation of a
1619 -- call to a user-defined equality operator.
1621 -- For the predefined case, the result is Boolean, regardless of the
1622 -- type of the operands. The operands may even be limited, if they are
1623 -- generic actuals. If they are overloaded, label the left argument with
1624 -- the common type that must be present, or with the type of the formal
1625 -- of the user-defined function.
1627 if Present (Entity (N)) then
1628 Op_Id := Entity (N);
1630 if Ekind (Op_Id) = E_Operator then
1631 Add_One_Interp (N, Op_Id, Standard_Boolean);
1633 Add_One_Interp (N, Op_Id, Etype (Op_Id));
1636 if Is_Overloaded (L) then
1637 if Ekind (Op_Id) = E_Operator then
1638 Set_Etype (L, Intersect_Types (L, R));
1640 Set_Etype (L, Etype (First_Formal (Op_Id)));
1645 Op_Id := Get_Name_Entity_Id (Chars (N));
1646 while Present (Op_Id) loop
1647 if Ekind (Op_Id) = E_Operator then
1648 Find_Equality_Types (L, R, Op_Id, N);
1650 Analyze_User_Defined_Binary_Op (N, Op_Id);
1653 Op_Id := Homonym (Op_Id);
1657 -- If there was no match, and the operator is inequality, this may
1658 -- be a case where inequality has not been made explicit, as for
1659 -- tagged types. Analyze the node as the negation of an equality
1660 -- operation. This cannot be done earlier, because before analysis
1661 -- we cannot rule out the presence of an explicit inequality.
1663 if Etype (N) = Any_Type
1664 and then Nkind (N) = N_Op_Ne
1666 Op_Id := Get_Name_Entity_Id (Name_Op_Eq);
1667 while Present (Op_Id) loop
1668 if Ekind (Op_Id) = E_Operator then
1669 Find_Equality_Types (L, R, Op_Id, N);
1671 Analyze_User_Defined_Binary_Op (N, Op_Id);
1674 Op_Id := Homonym (Op_Id);
1677 if Etype (N) /= Any_Type then
1678 Op_Id := Entity (N);
1684 Left_Opnd => Left_Opnd (N),
1685 Right_Opnd => Right_Opnd (N))));
1687 Set_Entity (Right_Opnd (N), Op_Id);
1693 end Analyze_Equality_Op;
1695 ----------------------------------
1696 -- Analyze_Explicit_Dereference --
1697 ----------------------------------
1699 procedure Analyze_Explicit_Dereference (N : Node_Id) is
1700 Loc : constant Source_Ptr := Sloc (N);
1701 P : constant Node_Id := Prefix (N);
1707 function Is_Function_Type return Boolean;
1708 -- Check whether node may be interpreted as an implicit function call
1710 ----------------------
1711 -- Is_Function_Type --
1712 ----------------------
1714 function Is_Function_Type return Boolean is
1719 if not Is_Overloaded (N) then
1720 return Ekind (Base_Type (Etype (N))) = E_Subprogram_Type
1721 and then Etype (Base_Type (Etype (N))) /= Standard_Void_Type;
1724 Get_First_Interp (N, I, It);
1725 while Present (It.Nam) loop
1726 if Ekind (Base_Type (It.Typ)) /= E_Subprogram_Type
1727 or else Etype (Base_Type (It.Typ)) = Standard_Void_Type
1732 Get_Next_Interp (I, It);
1737 end Is_Function_Type;
1739 -- Start of processing for Analyze_Explicit_Dereference
1742 Mark_Non_ALFA_Subprogram;
1743 Check_SPARK_Restriction ("explicit dereference is not allowed", N);
1746 Set_Etype (N, Any_Type);
1748 -- Test for remote access to subprogram type, and if so return
1749 -- after rewriting the original tree.
1751 if Remote_AST_E_Dereference (P) then
1755 -- Normal processing for other than remote access to subprogram type
1757 if not Is_Overloaded (P) then
1758 if Is_Access_Type (Etype (P)) then
1760 -- Set the Etype. We need to go through Is_For_Access_Subtypes to
1761 -- avoid other problems caused by the Private_Subtype and it is
1762 -- safe to go to the Base_Type because this is the same as
1763 -- converting the access value to its Base_Type.
1766 DT : Entity_Id := Designated_Type (Etype (P));
1769 if Ekind (DT) = E_Private_Subtype
1770 and then Is_For_Access_Subtype (DT)
1772 DT := Base_Type (DT);
1775 -- An explicit dereference is a legal occurrence of an
1776 -- incomplete type imported through a limited_with clause,
1777 -- if the full view is visible.
1779 if From_With_Type (DT)
1780 and then not From_With_Type (Scope (DT))
1782 (Is_Immediately_Visible (Scope (DT))
1784 (Is_Child_Unit (Scope (DT))
1785 and then Is_Visible_Child_Unit (Scope (DT))))
1787 Set_Etype (N, Available_View (DT));
1794 elsif Etype (P) /= Any_Type then
1795 Error_Msg_N ("prefix of dereference must be an access type", N);
1800 Get_First_Interp (P, I, It);
1801 while Present (It.Nam) loop
1804 if Is_Access_Type (T) then
1805 Add_One_Interp (N, Designated_Type (T), Designated_Type (T));
1808 Get_Next_Interp (I, It);
1811 -- Error if no interpretation of the prefix has an access type
1813 if Etype (N) = Any_Type then
1815 ("access type required in prefix of explicit dereference", P);
1816 Set_Etype (N, Any_Type);
1822 and then Nkind (Parent (N)) /= N_Indexed_Component
1824 and then (Nkind (Parent (N)) /= N_Function_Call
1825 or else N /= Name (Parent (N)))
1827 and then (Nkind (Parent (N)) /= N_Procedure_Call_Statement
1828 or else N /= Name (Parent (N)))
1830 and then Nkind (Parent (N)) /= N_Subprogram_Renaming_Declaration
1831 and then (Nkind (Parent (N)) /= N_Attribute_Reference
1833 (Attribute_Name (Parent (N)) /= Name_Address
1835 Attribute_Name (Parent (N)) /= Name_Access))
1837 -- Name is a function call with no actuals, in a context that
1838 -- requires deproceduring (including as an actual in an enclosing
1839 -- function or procedure call). There are some pathological cases
1840 -- where the prefix might include functions that return access to
1841 -- subprograms and others that return a regular type. Disambiguation
1842 -- of those has to take place in Resolve.
1845 Make_Function_Call (Loc,
1846 Name => Make_Explicit_Dereference (Loc, P),
1847 Parameter_Associations => New_List);
1849 -- If the prefix is overloaded, remove operations that have formals,
1850 -- we know that this is a parameterless call.
1852 if Is_Overloaded (P) then
1853 Get_First_Interp (P, I, It);
1854 while Present (It.Nam) loop
1857 if No (First_Formal (Base_Type (Designated_Type (T)))) then
1863 Get_Next_Interp (I, It);
1870 elsif not Is_Function_Type
1871 and then Is_Overloaded (N)
1873 -- The prefix may include access to subprograms and other access
1874 -- types. If the context selects the interpretation that is a
1875 -- function call (not a procedure call) we cannot rewrite the node
1876 -- yet, but we include the result of the call interpretation.
1878 Get_First_Interp (N, I, It);
1879 while Present (It.Nam) loop
1880 if Ekind (Base_Type (It.Typ)) = E_Subprogram_Type
1881 and then Etype (Base_Type (It.Typ)) /= Standard_Void_Type
1882 and then Nkind (Parent (N)) /= N_Procedure_Call_Statement
1884 Add_One_Interp (N, Etype (It.Typ), Etype (It.Typ));
1887 Get_Next_Interp (I, It);
1891 -- A value of remote access-to-class-wide must not be dereferenced
1894 Validate_Remote_Access_To_Class_Wide_Type (N);
1895 end Analyze_Explicit_Dereference;
1897 ------------------------
1898 -- Analyze_Expression --
1899 ------------------------
1901 procedure Analyze_Expression (N : Node_Id) is
1904 Check_Parameterless_Call (N);
1905 end Analyze_Expression;
1907 -------------------------------------
1908 -- Analyze_Expression_With_Actions --
1909 -------------------------------------
1911 procedure Analyze_Expression_With_Actions (N : Node_Id) is
1915 A := First (Actions (N));
1922 Analyze_Expression (Expression (N));
1923 Set_Etype (N, Etype (Expression (N)));
1924 end Analyze_Expression_With_Actions;
1926 ------------------------------------
1927 -- Analyze_Indexed_Component_Form --
1928 ------------------------------------
1930 procedure Analyze_Indexed_Component_Form (N : Node_Id) is
1931 P : constant Node_Id := Prefix (N);
1932 Exprs : constant List_Id := Expressions (N);
1938 procedure Process_Function_Call;
1939 -- Prefix in indexed component form is an overloadable entity,
1940 -- so the node is a function call. Reformat it as such.
1942 procedure Process_Indexed_Component;
1943 -- Prefix in indexed component form is actually an indexed component.
1944 -- This routine processes it, knowing that the prefix is already
1947 procedure Process_Indexed_Component_Or_Slice;
1948 -- An indexed component with a single index may designate a slice if
1949 -- the index is a subtype mark. This routine disambiguates these two
1950 -- cases by resolving the prefix to see if it is a subtype mark.
1952 procedure Process_Overloaded_Indexed_Component;
1953 -- If the prefix of an indexed component is overloaded, the proper
1954 -- interpretation is selected by the index types and the context.
1956 ---------------------------
1957 -- Process_Function_Call --
1958 ---------------------------
1960 procedure Process_Function_Call is
1964 Change_Node (N, N_Function_Call);
1966 Set_Parameter_Associations (N, Exprs);
1968 -- Analyze actuals prior to analyzing the call itself
1970 Actual := First (Parameter_Associations (N));
1971 while Present (Actual) loop
1973 Check_Parameterless_Call (Actual);
1975 -- Move to next actual. Note that we use Next, not Next_Actual
1976 -- here. The reason for this is a bit subtle. If a function call
1977 -- includes named associations, the parser recognizes the node as
1978 -- a call, and it is analyzed as such. If all associations are
1979 -- positional, the parser builds an indexed_component node, and
1980 -- it is only after analysis of the prefix that the construct
1981 -- is recognized as a call, in which case Process_Function_Call
1982 -- rewrites the node and analyzes the actuals. If the list of
1983 -- actuals is malformed, the parser may leave the node as an
1984 -- indexed component (despite the presence of named associations).
1985 -- The iterator Next_Actual is equivalent to Next if the list is
1986 -- positional, but follows the normalized chain of actuals when
1987 -- named associations are present. In this case normalization has
1988 -- not taken place, and actuals remain unanalyzed, which leads to
1989 -- subsequent crashes or loops if there is an attempt to continue
1990 -- analysis of the program.
1996 end Process_Function_Call;
1998 -------------------------------
1999 -- Process_Indexed_Component --
2000 -------------------------------
2002 procedure Process_Indexed_Component is
2004 Array_Type : Entity_Id;
2006 Pent : Entity_Id := Empty;
2009 Exp := First (Exprs);
2011 if Is_Overloaded (P) then
2012 Process_Overloaded_Indexed_Component;
2015 Array_Type := Etype (P);
2017 if Is_Entity_Name (P) then
2019 elsif Nkind (P) = N_Selected_Component
2020 and then Is_Entity_Name (Selector_Name (P))
2022 Pent := Entity (Selector_Name (P));
2025 -- Prefix must be appropriate for an array type, taking into
2026 -- account a possible implicit dereference.
2028 if Is_Access_Type (Array_Type) then
2029 Error_Msg_NW (Warn_On_Dereference, "?implicit dereference", N);
2030 Array_Type := Process_Implicit_Dereference_Prefix (Pent, P);
2033 if Is_Array_Type (Array_Type) then
2036 elsif Present (Pent) and then Ekind (Pent) = E_Entry_Family then
2038 Set_Etype (N, Any_Type);
2040 if not Has_Compatible_Type
2041 (Exp, Entry_Index_Type (Pent))
2043 Error_Msg_N ("invalid index type in entry name", N);
2045 elsif Present (Next (Exp)) then
2046 Error_Msg_N ("too many subscripts in entry reference", N);
2049 Set_Etype (N, Etype (P));
2054 elsif Is_Record_Type (Array_Type)
2055 and then Remote_AST_I_Dereference (P)
2059 elsif Array_Type = Any_Type then
2060 Set_Etype (N, Any_Type);
2062 -- In most cases the analysis of the prefix will have emitted
2063 -- an error already, but if the prefix may be interpreted as a
2064 -- call in prefixed notation, the report is left to the caller.
2065 -- To prevent cascaded errors, report only if no previous ones.
2067 if Serious_Errors_Detected = 0 then
2068 Error_Msg_N ("invalid prefix in indexed component", P);
2070 if Nkind (P) = N_Expanded_Name then
2071 Error_Msg_NE ("\& is not visible", P, Selector_Name (P));
2077 -- Here we definitely have a bad indexing
2080 if Nkind (Parent (N)) = N_Requeue_Statement
2081 and then Present (Pent) and then Ekind (Pent) = E_Entry
2084 ("REQUEUE does not permit parameters", First (Exprs));
2086 elsif Is_Entity_Name (P)
2087 and then Etype (P) = Standard_Void_Type
2089 Error_Msg_NE ("incorrect use of&", P, Entity (P));
2092 Error_Msg_N ("array type required in indexed component", P);
2095 Set_Etype (N, Any_Type);
2099 Index := First_Index (Array_Type);
2100 while Present (Index) and then Present (Exp) loop
2101 if not Has_Compatible_Type (Exp, Etype (Index)) then
2102 Wrong_Type (Exp, Etype (Index));
2103 Set_Etype (N, Any_Type);
2111 Set_Etype (N, Component_Type (Array_Type));
2113 if Present (Index) then
2115 ("too few subscripts in array reference", First (Exprs));
2117 elsif Present (Exp) then
2118 Error_Msg_N ("too many subscripts in array reference", Exp);
2121 end Process_Indexed_Component;
2123 ----------------------------------------
2124 -- Process_Indexed_Component_Or_Slice --
2125 ----------------------------------------
2127 procedure Process_Indexed_Component_Or_Slice is
2129 Exp := First (Exprs);
2130 while Present (Exp) loop
2131 Analyze_Expression (Exp);
2135 Exp := First (Exprs);
2137 -- If one index is present, and it is a subtype name, then the
2138 -- node denotes a slice (note that the case of an explicit range
2139 -- for a slice was already built as an N_Slice node in the first
2140 -- place, so that case is not handled here).
2142 -- We use a replace rather than a rewrite here because this is one
2143 -- of the cases in which the tree built by the parser is plain wrong.
2146 and then Is_Entity_Name (Exp)
2147 and then Is_Type (Entity (Exp))
2150 Make_Slice (Sloc (N),
2152 Discrete_Range => New_Copy (Exp)));
2155 -- Otherwise (more than one index present, or single index is not
2156 -- a subtype name), then we have the indexed component case.
2159 Process_Indexed_Component;
2161 end Process_Indexed_Component_Or_Slice;
2163 ------------------------------------------
2164 -- Process_Overloaded_Indexed_Component --
2165 ------------------------------------------
2167 procedure Process_Overloaded_Indexed_Component is
2176 Set_Etype (N, Any_Type);
2178 Get_First_Interp (P, I, It);
2179 while Present (It.Nam) loop
2182 if Is_Access_Type (Typ) then
2183 Typ := Designated_Type (Typ);
2184 Error_Msg_NW (Warn_On_Dereference, "?implicit dereference", N);
2187 if Is_Array_Type (Typ) then
2189 -- Got a candidate: verify that index types are compatible
2191 Index := First_Index (Typ);
2193 Exp := First (Exprs);
2194 while Present (Index) and then Present (Exp) loop
2195 if Has_Compatible_Type (Exp, Etype (Index)) then
2207 if Found and then No (Index) and then No (Exp) then
2209 Etype (Component_Type (Typ)),
2210 Etype (Component_Type (Typ)));
2214 Get_Next_Interp (I, It);
2217 if Etype (N) = Any_Type then
2218 Error_Msg_N ("no legal interpretation for indexed component", N);
2219 Set_Is_Overloaded (N, False);
2223 end Process_Overloaded_Indexed_Component;
2225 -- Start of processing for Analyze_Indexed_Component_Form
2228 -- Get name of array, function or type
2232 if Nkind_In (N, N_Function_Call, N_Procedure_Call_Statement) then
2234 -- If P is an explicit dereference whose prefix is of a
2235 -- remote access-to-subprogram type, then N has already
2236 -- been rewritten as a subprogram call and analyzed.
2241 pragma Assert (Nkind (N) = N_Indexed_Component);
2243 P_T := Base_Type (Etype (P));
2245 if Is_Entity_Name (P) and then Present (Entity (P)) then
2248 if Is_Type (U_N) then
2250 -- Reformat node as a type conversion
2252 E := Remove_Head (Exprs);
2254 if Present (First (Exprs)) then
2256 ("argument of type conversion must be single expression", N);
2259 Change_Node (N, N_Type_Conversion);
2260 Set_Subtype_Mark (N, P);
2262 Set_Expression (N, E);
2264 -- After changing the node, call for the specific Analysis
2265 -- routine directly, to avoid a double call to the expander.
2267 Analyze_Type_Conversion (N);
2271 if Is_Overloadable (U_N) then
2272 Process_Function_Call;
2274 elsif Ekind (Etype (P)) = E_Subprogram_Type
2275 or else (Is_Access_Type (Etype (P))
2277 Ekind (Designated_Type (Etype (P))) =
2280 -- Call to access_to-subprogram with possible implicit dereference
2282 Process_Function_Call;
2284 elsif Is_Generic_Subprogram (U_N) then
2286 -- A common beginner's (or C++ templates fan) error
2288 Error_Msg_N ("generic subprogram cannot be called", N);
2289 Set_Etype (N, Any_Type);
2293 Process_Indexed_Component_Or_Slice;
2296 -- If not an entity name, prefix is an expression that may denote
2297 -- an array or an access-to-subprogram.
2300 if Ekind (P_T) = E_Subprogram_Type
2301 or else (Is_Access_Type (P_T)
2303 Ekind (Designated_Type (P_T)) = E_Subprogram_Type)
2305 Process_Function_Call;
2307 elsif Nkind (P) = N_Selected_Component
2308 and then Is_Overloadable (Entity (Selector_Name (P)))
2310 Process_Function_Call;
2313 -- Indexed component, slice, or a call to a member of a family
2314 -- entry, which will be converted to an entry call later.
2316 Process_Indexed_Component_Or_Slice;
2319 end Analyze_Indexed_Component_Form;
2321 ------------------------
2322 -- Analyze_Logical_Op --
2323 ------------------------
2325 procedure Analyze_Logical_Op (N : Node_Id) is
2326 L : constant Node_Id := Left_Opnd (N);
2327 R : constant Node_Id := Right_Opnd (N);
2328 Op_Id : Entity_Id := Entity (N);
2331 Set_Etype (N, Any_Type);
2332 Candidate_Type := Empty;
2334 Analyze_Expression (L);
2335 Analyze_Expression (R);
2337 if Present (Op_Id) then
2339 if Ekind (Op_Id) = E_Operator then
2340 Find_Boolean_Types (L, R, Op_Id, N);
2342 Add_One_Interp (N, Op_Id, Etype (Op_Id));
2346 Op_Id := Get_Name_Entity_Id (Chars (N));
2347 while Present (Op_Id) loop
2348 if Ekind (Op_Id) = E_Operator then
2349 Find_Boolean_Types (L, R, Op_Id, N);
2351 Analyze_User_Defined_Binary_Op (N, Op_Id);
2354 Op_Id := Homonym (Op_Id);
2359 end Analyze_Logical_Op;
2361 ---------------------------
2362 -- Analyze_Membership_Op --
2363 ---------------------------
2365 procedure Analyze_Membership_Op (N : Node_Id) is
2366 Loc : constant Source_Ptr := Sloc (N);
2367 L : constant Node_Id := Left_Opnd (N);
2368 R : constant Node_Id := Right_Opnd (N);
2370 Index : Interp_Index;
2372 Found : Boolean := False;
2376 procedure Try_One_Interp (T1 : Entity_Id);
2377 -- Routine to try one proposed interpretation. Note that the context
2378 -- of the operation plays no role in resolving the arguments, so that
2379 -- if there is more than one interpretation of the operands that is
2380 -- compatible with a membership test, the operation is ambiguous.
2382 --------------------
2383 -- Try_One_Interp --
2384 --------------------
2386 procedure Try_One_Interp (T1 : Entity_Id) is
2388 if Has_Compatible_Type (R, T1) then
2390 and then Base_Type (T1) /= Base_Type (T_F)
2392 It := Disambiguate (L, I_F, Index, Any_Type);
2394 if It = No_Interp then
2395 Ambiguous_Operands (N);
2396 Set_Etype (L, Any_Type);
2413 procedure Analyze_Set_Membership;
2414 -- If a set of alternatives is present, analyze each and find the
2415 -- common type to which they must all resolve.
2417 ----------------------------
2418 -- Analyze_Set_Membership --
2419 ----------------------------
2421 procedure Analyze_Set_Membership is
2423 Index : Interp_Index;
2425 Candidate_Interps : Node_Id;
2426 Common_Type : Entity_Id := Empty;
2430 Candidate_Interps := L;
2432 if not Is_Overloaded (L) then
2433 Common_Type := Etype (L);
2435 Alt := First (Alternatives (N));
2436 while Present (Alt) loop
2439 if not Has_Compatible_Type (Alt, Common_Type) then
2440 Wrong_Type (Alt, Common_Type);
2447 Alt := First (Alternatives (N));
2448 while Present (Alt) loop
2450 if not Is_Overloaded (Alt) then
2451 Common_Type := Etype (Alt);
2454 Get_First_Interp (Alt, Index, It);
2455 while Present (It.Typ) loop
2457 Has_Compatible_Type (Candidate_Interps, It.Typ)
2459 Remove_Interp (Index);
2462 Get_Next_Interp (Index, It);
2465 Get_First_Interp (Alt, Index, It);
2468 Error_Msg_N ("alternative has no legal type", Alt);
2472 -- If alternative is not overloaded, we have a unique type
2475 Set_Etype (Alt, It.Typ);
2476 Get_Next_Interp (Index, It);
2479 Set_Is_Overloaded (Alt, False);
2480 Common_Type := Etype (Alt);
2483 Candidate_Interps := Alt;
2490 Set_Etype (N, Standard_Boolean);
2492 if Present (Common_Type) then
2493 Set_Etype (L, Common_Type);
2494 Set_Is_Overloaded (L, False);
2497 Error_Msg_N ("cannot resolve membership operation", N);
2499 end Analyze_Set_Membership;
2501 -- Start of processing for Analyze_Membership_Op
2504 Analyze_Expression (L);
2507 and then Ada_Version >= Ada_2012
2509 Analyze_Set_Membership;
2513 if Nkind (R) = N_Range
2514 or else (Nkind (R) = N_Attribute_Reference
2515 and then Attribute_Name (R) = Name_Range)
2519 if not Is_Overloaded (L) then
2520 Try_One_Interp (Etype (L));
2523 Get_First_Interp (L, Index, It);
2524 while Present (It.Typ) loop
2525 Try_One_Interp (It.Typ);
2526 Get_Next_Interp (Index, It);
2530 -- If not a range, it can be a subtype mark, or else it is a degenerate
2531 -- membership test with a singleton value, i.e. a test for equality,
2532 -- if the types are compatible.
2536 if Is_Entity_Name (R)
2537 and then Is_Type (Entity (R))
2540 Check_Fully_Declared (Entity (R), R);
2542 elsif Ada_Version >= Ada_2012
2543 and then Has_Compatible_Type (R, Etype (L))
2545 if Nkind (N) = N_In then
2561 -- In all versions of the language, if we reach this point there
2562 -- is a previous error that will be diagnosed below.
2568 -- Compatibility between expression and subtype mark or range is
2569 -- checked during resolution. The result of the operation is Boolean
2572 Set_Etype (N, Standard_Boolean);
2574 if Comes_From_Source (N)
2575 and then Present (Right_Opnd (N))
2576 and then Is_CPP_Class (Etype (Etype (Right_Opnd (N))))
2578 Error_Msg_N ("membership test not applicable to cpp-class types", N);
2580 end Analyze_Membership_Op;
2582 ----------------------
2583 -- Analyze_Negation --
2584 ----------------------
2586 procedure Analyze_Negation (N : Node_Id) is
2587 R : constant Node_Id := Right_Opnd (N);
2588 Op_Id : Entity_Id := Entity (N);
2591 Set_Etype (N, Any_Type);
2592 Candidate_Type := Empty;
2594 Analyze_Expression (R);
2596 if Present (Op_Id) then
2597 if Ekind (Op_Id) = E_Operator then
2598 Find_Negation_Types (R, Op_Id, N);
2600 Add_One_Interp (N, Op_Id, Etype (Op_Id));
2604 Op_Id := Get_Name_Entity_Id (Chars (N));
2605 while Present (Op_Id) loop
2606 if Ekind (Op_Id) = E_Operator then
2607 Find_Negation_Types (R, Op_Id, N);
2609 Analyze_User_Defined_Unary_Op (N, Op_Id);
2612 Op_Id := Homonym (Op_Id);
2617 end Analyze_Negation;
2623 procedure Analyze_Null (N : Node_Id) is
2625 Mark_Non_ALFA_Subprogram;
2626 Check_SPARK_Restriction ("null is not allowed", N);
2628 Set_Etype (N, Any_Access);
2631 ----------------------
2632 -- Analyze_One_Call --
2633 ----------------------
2635 procedure Analyze_One_Call
2639 Success : out Boolean;
2640 Skip_First : Boolean := False)
2642 Actuals : constant List_Id := Parameter_Associations (N);
2643 Prev_T : constant Entity_Id := Etype (N);
2645 Must_Skip : constant Boolean := Skip_First
2646 or else Nkind (Original_Node (N)) = N_Selected_Component
2648 (Nkind (Original_Node (N)) = N_Indexed_Component
2649 and then Nkind (Prefix (Original_Node (N)))
2650 = N_Selected_Component);
2651 -- The first formal must be omitted from the match when trying to find
2652 -- a primitive operation that is a possible interpretation, and also
2653 -- after the call has been rewritten, because the corresponding actual
2654 -- is already known to be compatible, and because this may be an
2655 -- indexing of a call with default parameters.
2659 Is_Indexed : Boolean := False;
2660 Is_Indirect : Boolean := False;
2661 Subp_Type : constant Entity_Id := Etype (Nam);
2664 function Operator_Hidden_By (Fun : Entity_Id) return Boolean;
2665 -- There may be a user-defined operator that hides the current
2666 -- interpretation. We must check for this independently of the
2667 -- analysis of the call with the user-defined operation, because
2668 -- the parameter names may be wrong and yet the hiding takes place.
2669 -- This fixes a problem with ACATS test B34014O.
2671 -- When the type Address is a visible integer type, and the DEC
2672 -- system extension is visible, the predefined operator may be
2673 -- hidden as well, by one of the address operations in auxdec.
2674 -- Finally, The abstract operations on address do not hide the
2675 -- predefined operator (this is the purpose of making them abstract).
2677 procedure Indicate_Name_And_Type;
2678 -- If candidate interpretation matches, indicate name and type of
2679 -- result on call node.
2681 ----------------------------
2682 -- Indicate_Name_And_Type --
2683 ----------------------------
2685 procedure Indicate_Name_And_Type is
2687 Add_One_Interp (N, Nam, Etype (Nam));
2690 -- If the prefix of the call is a name, indicate the entity
2691 -- being called. If it is not a name, it is an expression that
2692 -- denotes an access to subprogram or else an entry or family. In
2693 -- the latter case, the name is a selected component, and the entity
2694 -- being called is noted on the selector.
2696 if not Is_Type (Nam) then
2697 if Is_Entity_Name (Name (N)) then
2698 Set_Entity (Name (N), Nam);
2700 elsif Nkind (Name (N)) = N_Selected_Component then
2701 Set_Entity (Selector_Name (Name (N)), Nam);
2705 if Debug_Flag_E and not Report then
2706 Write_Str (" Overloaded call ");
2707 Write_Int (Int (N));
2708 Write_Str (" compatible with ");
2709 Write_Int (Int (Nam));
2712 end Indicate_Name_And_Type;
2714 ------------------------
2715 -- Operator_Hidden_By --
2716 ------------------------
2718 function Operator_Hidden_By (Fun : Entity_Id) return Boolean is
2719 Act1 : constant Node_Id := First_Actual (N);
2720 Act2 : constant Node_Id := Next_Actual (Act1);
2721 Form1 : constant Entity_Id := First_Formal (Fun);
2722 Form2 : constant Entity_Id := Next_Formal (Form1);
2725 if Ekind (Fun) /= E_Function
2726 or else Is_Abstract_Subprogram (Fun)
2730 elsif not Has_Compatible_Type (Act1, Etype (Form1)) then
2733 elsif Present (Form2) then
2735 No (Act2) or else not Has_Compatible_Type (Act2, Etype (Form2))
2740 elsif Present (Act2) then
2744 -- Now we know that the arity of the operator matches the function,
2745 -- and the function call is a valid interpretation. The function
2746 -- hides the operator if it has the right signature, or if one of
2747 -- its operands is a non-abstract operation on Address when this is
2748 -- a visible integer type.
2750 return Hides_Op (Fun, Nam)
2751 or else Is_Descendent_Of_Address (Etype (Form1))
2754 and then Is_Descendent_Of_Address (Etype (Form2)));
2755 end Operator_Hidden_By;
2757 -- Start of processing for Analyze_One_Call
2762 -- If the subprogram has no formals or if all the formals have defaults,
2763 -- and the return type is an array type, the node may denote an indexing
2764 -- of the result of a parameterless call. In Ada 2005, the subprogram
2765 -- may have one non-defaulted formal, and the call may have been written
2766 -- in prefix notation, so that the rebuilt parameter list has more than
2769 if not Is_Overloadable (Nam)
2770 and then Ekind (Nam) /= E_Subprogram_Type
2771 and then Ekind (Nam) /= E_Entry_Family
2776 -- An indexing requires at least one actual
2778 if not Is_Empty_List (Actuals)
2780 (Needs_No_Actuals (Nam)
2782 (Needs_One_Actual (Nam)
2783 and then Present (Next_Actual (First (Actuals)))))
2785 if Is_Array_Type (Subp_Type) then
2786 Is_Indexed := Try_Indexed_Call (N, Nam, Subp_Type, Must_Skip);
2788 elsif Is_Access_Type (Subp_Type)
2789 and then Is_Array_Type (Designated_Type (Subp_Type))
2793 (N, Nam, Designated_Type (Subp_Type), Must_Skip);
2795 -- The prefix can also be a parameterless function that returns an
2796 -- access to subprogram, in which case this is an indirect call.
2797 -- If this succeeds, an explicit dereference is added later on,
2798 -- in Analyze_Call or Resolve_Call.
2800 elsif Is_Access_Type (Subp_Type)
2801 and then Ekind (Designated_Type (Subp_Type)) = E_Subprogram_Type
2803 Is_Indirect := Try_Indirect_Call (N, Nam, Subp_Type);
2808 -- If the call has been transformed into a slice, it is of the form
2809 -- F (Subtype) where F is parameterless. The node has been rewritten in
2810 -- Try_Indexed_Call and there is nothing else to do.
2813 and then Nkind (N) = N_Slice
2819 (N, Nam, (Report and not Is_Indexed and not Is_Indirect), Norm_OK);
2823 -- If an indirect call is a possible interpretation, indicate
2824 -- success to the caller.
2830 -- Mismatch in number or names of parameters
2832 elsif Debug_Flag_E then
2833 Write_Str (" normalization fails in call ");
2834 Write_Int (Int (N));
2835 Write_Str (" with subprogram ");
2836 Write_Int (Int (Nam));
2840 -- If the context expects a function call, discard any interpretation
2841 -- that is a procedure. If the node is not overloaded, leave as is for
2842 -- better error reporting when type mismatch is found.
2844 elsif Nkind (N) = N_Function_Call
2845 and then Is_Overloaded (Name (N))
2846 and then Ekind (Nam) = E_Procedure
2850 -- Ditto for function calls in a procedure context
2852 elsif Nkind (N) = N_Procedure_Call_Statement
2853 and then Is_Overloaded (Name (N))
2854 and then Etype (Nam) /= Standard_Void_Type
2858 elsif No (Actuals) then
2860 -- If Normalize succeeds, then there are default parameters for
2863 Indicate_Name_And_Type;
2865 elsif Ekind (Nam) = E_Operator then
2866 if Nkind (N) = N_Procedure_Call_Statement then
2870 -- This can occur when the prefix of the call is an operator
2871 -- name or an expanded name whose selector is an operator name.
2873 Analyze_Operator_Call (N, Nam);
2875 if Etype (N) /= Prev_T then
2877 -- Check that operator is not hidden by a function interpretation
2879 if Is_Overloaded (Name (N)) then
2885 Get_First_Interp (Name (N), I, It);
2886 while Present (It.Nam) loop
2887 if Operator_Hidden_By (It.Nam) then
2888 Set_Etype (N, Prev_T);
2892 Get_Next_Interp (I, It);
2897 -- If operator matches formals, record its name on the call.
2898 -- If the operator is overloaded, Resolve will select the
2899 -- correct one from the list of interpretations. The call
2900 -- node itself carries the first candidate.
2902 Set_Entity (Name (N), Nam);
2905 elsif Report and then Etype (N) = Any_Type then
2906 Error_Msg_N ("incompatible arguments for operator", N);
2910 -- Normalize_Actuals has chained the named associations in the
2911 -- correct order of the formals.
2913 Actual := First_Actual (N);
2914 Formal := First_Formal (Nam);
2916 -- If we are analyzing a call rewritten from object notation, skip
2917 -- first actual, which may be rewritten later as an explicit
2921 Next_Actual (Actual);
2922 Next_Formal (Formal);
2925 while Present (Actual) and then Present (Formal) loop
2926 if Nkind (Parent (Actual)) /= N_Parameter_Association
2927 or else Chars (Selector_Name (Parent (Actual))) = Chars (Formal)
2929 -- The actual can be compatible with the formal, but we must
2930 -- also check that the context is not an address type that is
2931 -- visibly an integer type, as is the case in VMS_64. In this
2932 -- case the use of literals is illegal, except in the body of
2933 -- descendents of system, where arithmetic operations on
2934 -- address are of course used.
2936 if Has_Compatible_Type (Actual, Etype (Formal))
2938 (Etype (Actual) /= Universal_Integer
2939 or else not Is_Descendent_Of_Address (Etype (Formal))
2941 Is_Predefined_File_Name
2942 (Unit_File_Name (Get_Source_Unit (N))))
2944 Next_Actual (Actual);
2945 Next_Formal (Formal);
2948 if Debug_Flag_E then
2949 Write_Str (" type checking fails in call ");
2950 Write_Int (Int (N));
2951 Write_Str (" with formal ");
2952 Write_Int (Int (Formal));
2953 Write_Str (" in subprogram ");
2954 Write_Int (Int (Nam));
2958 if Report and not Is_Indexed and not Is_Indirect then
2960 -- Ada 2005 (AI-251): Complete the error notification
2961 -- to help new Ada 2005 users.
2963 if Is_Class_Wide_Type (Etype (Formal))
2964 and then Is_Interface (Etype (Etype (Formal)))
2965 and then not Interface_Present_In_Ancestor
2966 (Typ => Etype (Actual),
2967 Iface => Etype (Etype (Formal)))
2970 ("(Ada 2005) does not implement interface }",
2971 Actual, Etype (Etype (Formal)));
2974 Wrong_Type (Actual, Etype (Formal));
2976 if Nkind (Actual) = N_Op_Eq
2977 and then Nkind (Left_Opnd (Actual)) = N_Identifier
2979 Formal := First_Formal (Nam);
2980 while Present (Formal) loop
2981 if Chars (Left_Opnd (Actual)) = Chars (Formal) then
2982 Error_Msg_N -- CODEFIX
2983 ("possible misspelling of `='>`!", Actual);
2987 Next_Formal (Formal);
2991 if All_Errors_Mode then
2992 Error_Msg_Sloc := Sloc (Nam);
2994 if Etype (Formal) = Any_Type then
2996 ("there is no legal actual parameter", Actual);
2999 if Is_Overloadable (Nam)
3000 and then Present (Alias (Nam))
3001 and then not Comes_From_Source (Nam)
3004 ("\\ =='> in call to inherited operation & #!",
3007 elsif Ekind (Nam) = E_Subprogram_Type then
3009 Access_To_Subprogram_Typ :
3010 constant Entity_Id :=
3012 (Associated_Node_For_Itype (Nam));
3015 "\\ =='> in call to dereference of &#!",
3016 Actual, Access_To_Subprogram_Typ);
3021 ("\\ =='> in call to &#!", Actual, Nam);
3031 -- Normalize_Actuals has verified that a default value exists
3032 -- for this formal. Current actual names a subsequent formal.
3034 Next_Formal (Formal);
3038 -- On exit, all actuals match
3040 Indicate_Name_And_Type;
3042 end Analyze_One_Call;
3044 ---------------------------
3045 -- Analyze_Operator_Call --
3046 ---------------------------
3048 procedure Analyze_Operator_Call (N : Node_Id; Op_Id : Entity_Id) is
3049 Op_Name : constant Name_Id := Chars (Op_Id);
3050 Act1 : constant Node_Id := First_Actual (N);
3051 Act2 : constant Node_Id := Next_Actual (Act1);
3054 -- Binary operator case
3056 if Present (Act2) then
3058 -- If more than two operands, then not binary operator after all
3060 if Present (Next_Actual (Act2)) then
3063 elsif Op_Name = Name_Op_Add
3064 or else Op_Name = Name_Op_Subtract
3065 or else Op_Name = Name_Op_Multiply
3066 or else Op_Name = Name_Op_Divide
3067 or else Op_Name = Name_Op_Mod
3068 or else Op_Name = Name_Op_Rem
3069 or else Op_Name = Name_Op_Expon
3071 Find_Arithmetic_Types (Act1, Act2, Op_Id, N);
3073 elsif Op_Name = Name_Op_And
3074 or else Op_Name = Name_Op_Or
3075 or else Op_Name = Name_Op_Xor
3077 Find_Boolean_Types (Act1, Act2, Op_Id, N);
3079 elsif Op_Name = Name_Op_Lt
3080 or else Op_Name = Name_Op_Le
3081 or else Op_Name = Name_Op_Gt
3082 or else Op_Name = Name_Op_Ge
3084 Find_Comparison_Types (Act1, Act2, Op_Id, N);
3086 elsif Op_Name = Name_Op_Eq
3087 or else Op_Name = Name_Op_Ne
3089 Find_Equality_Types (Act1, Act2, Op_Id, N);
3091 elsif Op_Name = Name_Op_Concat then
3092 Find_Concatenation_Types (Act1, Act2, Op_Id, N);
3094 -- Is this else null correct, or should it be an abort???
3100 -- Unary operator case
3103 if Op_Name = Name_Op_Subtract or else
3104 Op_Name = Name_Op_Add or else
3105 Op_Name = Name_Op_Abs
3107 Find_Unary_Types (Act1, Op_Id, N);
3110 Op_Name = Name_Op_Not
3112 Find_Negation_Types (Act1, Op_Id, N);
3114 -- Is this else null correct, or should it be an abort???
3120 end Analyze_Operator_Call;
3122 -------------------------------------------
3123 -- Analyze_Overloaded_Selected_Component --
3124 -------------------------------------------
3126 procedure Analyze_Overloaded_Selected_Component (N : Node_Id) is
3127 Nam : constant Node_Id := Prefix (N);
3128 Sel : constant Node_Id := Selector_Name (N);
3135 Set_Etype (Sel, Any_Type);
3137 Get_First_Interp (Nam, I, It);
3138 while Present (It.Typ) loop
3139 if Is_Access_Type (It.Typ) then
3140 T := Designated_Type (It.Typ);
3141 Error_Msg_NW (Warn_On_Dereference, "?implicit dereference", N);
3146 -- Locate the component. For a private prefix the selector can denote
3149 if Is_Record_Type (T) or else Is_Private_Type (T) then
3151 -- If the prefix is a class-wide type, the visible components are
3152 -- those of the base type.
3154 if Is_Class_Wide_Type (T) then
3158 Comp := First_Entity (T);
3159 while Present (Comp) loop
3160 if Chars (Comp) = Chars (Sel)
3161 and then Is_Visible_Component (Comp)
3164 -- AI05-105: if the context is an object renaming with
3165 -- an anonymous access type, the expected type of the
3166 -- object must be anonymous. This is a name resolution rule.
3168 if Nkind (Parent (N)) /= N_Object_Renaming_Declaration
3169 or else No (Access_Definition (Parent (N)))
3170 or else Ekind (Etype (Comp)) = E_Anonymous_Access_Type
3172 Ekind (Etype (Comp)) = E_Anonymous_Access_Subprogram_Type
3174 Set_Entity (Sel, Comp);
3175 Set_Etype (Sel, Etype (Comp));
3176 Add_One_Interp (N, Etype (Comp), Etype (Comp));
3178 -- This also specifies a candidate to resolve the name.
3179 -- Further overloading will be resolved from context.
3180 -- The selector name itself does not carry overloading
3183 Set_Etype (Nam, It.Typ);
3186 -- Named access type in the context of a renaming
3187 -- declaration with an access definition. Remove
3188 -- inapplicable candidate.
3197 elsif Is_Concurrent_Type (T) then
3198 Comp := First_Entity (T);
3199 while Present (Comp)
3200 and then Comp /= First_Private_Entity (T)
3202 if Chars (Comp) = Chars (Sel) then
3203 if Is_Overloadable (Comp) then
3204 Add_One_Interp (Sel, Comp, Etype (Comp));
3206 Set_Entity_With_Style_Check (Sel, Comp);
3207 Generate_Reference (Comp, Sel);
3210 Set_Etype (Sel, Etype (Comp));
3211 Set_Etype (N, Etype (Comp));
3212 Set_Etype (Nam, It.Typ);
3214 -- For access type case, introduce explicit dereference for
3215 -- more uniform treatment of entry calls. Do this only once
3216 -- if several interpretations yield an access type.
3218 if Is_Access_Type (Etype (Nam))
3219 and then Nkind (Nam) /= N_Explicit_Dereference
3221 Insert_Explicit_Dereference (Nam);
3223 (Warn_On_Dereference, "?implicit dereference", N);
3230 Set_Is_Overloaded (N, Is_Overloaded (Sel));
3233 Get_Next_Interp (I, It);
3236 if Etype (N) = Any_Type
3237 and then not Try_Object_Operation (N)
3239 Error_Msg_NE ("undefined selector& for overloaded prefix", N, Sel);
3240 Set_Entity (Sel, Any_Id);
3241 Set_Etype (Sel, Any_Type);
3243 end Analyze_Overloaded_Selected_Component;
3245 ----------------------------------
3246 -- Analyze_Qualified_Expression --
3247 ----------------------------------
3249 procedure Analyze_Qualified_Expression (N : Node_Id) is
3250 Mark : constant Entity_Id := Subtype_Mark (N);
3251 Expr : constant Node_Id := Expression (N);
3257 Mark_Non_ALFA_Subprogram;
3259 Analyze_Expression (Expr);
3261 Set_Etype (N, Any_Type);
3266 if T = Any_Type then
3270 Check_Fully_Declared (T, N);
3272 -- If expected type is class-wide, check for exact match before
3273 -- expansion, because if the expression is a dispatching call it
3274 -- may be rewritten as explicit dereference with class-wide result.
3275 -- If expression is overloaded, retain only interpretations that
3276 -- will yield exact matches.
3278 if Is_Class_Wide_Type (T) then
3279 if not Is_Overloaded (Expr) then
3280 if Base_Type (Etype (Expr)) /= Base_Type (T) then
3281 if Nkind (Expr) = N_Aggregate then
3282 Error_Msg_N ("type of aggregate cannot be class-wide", Expr);
3284 Wrong_Type (Expr, T);
3289 Get_First_Interp (Expr, I, It);
3291 while Present (It.Nam) loop
3292 if Base_Type (It.Typ) /= Base_Type (T) then
3296 Get_Next_Interp (I, It);
3302 end Analyze_Qualified_Expression;
3304 -----------------------------------
3305 -- Analyze_Quantified_Expression --
3306 -----------------------------------
3308 procedure Analyze_Quantified_Expression (N : Node_Id) is
3309 Loc : constant Source_Ptr := Sloc (N);
3310 Ent : constant Entity_Id :=
3312 (E_Loop, Current_Scope, Sloc (N), 'L');
3317 Mark_Non_ALFA_Subprogram;
3318 Check_SPARK_Restriction ("quantified expression is not allowed", N);
3320 Set_Etype (Ent, Standard_Void_Type);
3321 Set_Parent (Ent, N);
3323 if Present (Loop_Parameter_Specification (N)) then
3325 Make_Iteration_Scheme (Loc,
3326 Loop_Parameter_Specification =>
3327 Loop_Parameter_Specification (N));
3330 Make_Iteration_Scheme (Loc,
3331 Iterator_Specification =>
3332 Iterator_Specification (N));
3336 Set_Parent (Iterator, N);
3337 Analyze_Iteration_Scheme (Iterator);
3339 -- The loop specification may have been converted into an
3340 -- iterator specification during its analysis. Update the
3341 -- quantified node accordingly.
3343 if Present (Iterator_Specification (Iterator)) then
3344 Set_Iterator_Specification
3345 (N, Iterator_Specification (Iterator));
3346 Set_Loop_Parameter_Specification (N, Empty);
3349 Analyze (Condition (N));
3352 Set_Etype (N, Standard_Boolean);
3353 end Analyze_Quantified_Expression;
3359 procedure Analyze_Range (N : Node_Id) is
3360 L : constant Node_Id := Low_Bound (N);
3361 H : constant Node_Id := High_Bound (N);
3362 I1, I2 : Interp_Index;
3365 procedure Check_Common_Type (T1, T2 : Entity_Id);
3366 -- Verify the compatibility of two types, and choose the
3367 -- non universal one if the other is universal.
3369 procedure Check_High_Bound (T : Entity_Id);
3370 -- Test one interpretation of the low bound against all those
3371 -- of the high bound.
3373 procedure Check_Universal_Expression (N : Node_Id);
3374 -- In Ada83, reject bounds of a universal range that are not
3375 -- literals or entity names.
3377 -----------------------
3378 -- Check_Common_Type --
3379 -----------------------
3381 procedure Check_Common_Type (T1, T2 : Entity_Id) is
3383 if Covers (T1 => T1, T2 => T2)
3385 Covers (T1 => T2, T2 => T1)
3387 if T1 = Universal_Integer
3388 or else T1 = Universal_Real
3389 or else T1 = Any_Character
3391 Add_One_Interp (N, Base_Type (T2), Base_Type (T2));
3394 Add_One_Interp (N, T1, T1);
3397 Add_One_Interp (N, Base_Type (T1), Base_Type (T1));
3400 end Check_Common_Type;
3402 ----------------------
3403 -- Check_High_Bound --
3404 ----------------------
3406 procedure Check_High_Bound (T : Entity_Id) is
3408 if not Is_Overloaded (H) then
3409 Check_Common_Type (T, Etype (H));
3411 Get_First_Interp (H, I2, It2);
3412 while Present (It2.Typ) loop
3413 Check_Common_Type (T, It2.Typ);
3414 Get_Next_Interp (I2, It2);
3417 end Check_High_Bound;
3419 -----------------------------
3420 -- Is_Universal_Expression --
3421 -----------------------------
3423 procedure Check_Universal_Expression (N : Node_Id) is
3425 if Etype (N) = Universal_Integer
3426 and then Nkind (N) /= N_Integer_Literal
3427 and then not Is_Entity_Name (N)
3428 and then Nkind (N) /= N_Attribute_Reference
3430 Error_Msg_N ("illegal bound in discrete range", N);
3432 end Check_Universal_Expression;
3434 -- Start of processing for Analyze_Range
3437 Set_Etype (N, Any_Type);
3438 Analyze_Expression (L);
3439 Analyze_Expression (H);
3441 if Etype (L) = Any_Type or else Etype (H) = Any_Type then
3445 if not Is_Overloaded (L) then
3446 Check_High_Bound (Etype (L));
3448 Get_First_Interp (L, I1, It1);
3449 while Present (It1.Typ) loop
3450 Check_High_Bound (It1.Typ);
3451 Get_Next_Interp (I1, It1);
3455 -- If result is Any_Type, then we did not find a compatible pair
3457 if Etype (N) = Any_Type then
3458 Error_Msg_N ("incompatible types in range ", N);
3462 if Ada_Version = Ada_83
3464 (Nkind (Parent (N)) = N_Loop_Parameter_Specification
3465 or else Nkind (Parent (N)) = N_Constrained_Array_Definition)
3467 Check_Universal_Expression (L);
3468 Check_Universal_Expression (H);
3472 -----------------------
3473 -- Analyze_Reference --
3474 -----------------------
3476 procedure Analyze_Reference (N : Node_Id) is
3477 P : constant Node_Id := Prefix (N);
3480 Acc_Type : Entity_Id;
3483 Mark_Non_ALFA_Subprogram;
3487 -- An interesting error check, if we take the 'Reference of an object
3488 -- for which a pragma Atomic or Volatile has been given, and the type
3489 -- of the object is not Atomic or Volatile, then we are in trouble. The
3490 -- problem is that no trace of the atomic/volatile status will remain
3491 -- for the backend to respect when it deals with the resulting pointer,
3492 -- since the pointer type will not be marked atomic (it is a pointer to
3493 -- the base type of the object).
3495 -- It is not clear if that can ever occur, but in case it does, we will
3496 -- generate an error message. Not clear if this message can ever be
3497 -- generated, and pretty clear that it represents a bug if it is, still
3498 -- seems worth checking, except in CodePeer mode where we do not really
3499 -- care and don't want to bother the user.
3503 if Is_Entity_Name (P)
3504 and then Is_Object_Reference (P)
3505 and then not CodePeer_Mode
3510 if (Has_Atomic_Components (E)
3511 and then not Has_Atomic_Components (T))
3513 (Has_Volatile_Components (E)
3514 and then not Has_Volatile_Components (T))
3515 or else (Is_Atomic (E) and then not Is_Atomic (T))
3516 or else (Is_Volatile (E) and then not Is_Volatile (T))
3518 Error_Msg_N ("cannot take reference to Atomic/Volatile object", N);
3522 -- Carry on with normal processing
3524 Acc_Type := Create_Itype (E_Allocator_Type, N);
3525 Set_Etype (Acc_Type, Acc_Type);
3526 Set_Directly_Designated_Type (Acc_Type, Etype (P));
3527 Set_Etype (N, Acc_Type);
3528 end Analyze_Reference;
3530 --------------------------------
3531 -- Analyze_Selected_Component --
3532 --------------------------------
3534 -- Prefix is a record type or a task or protected type. In the latter case,
3535 -- the selector must denote a visible entry.
3537 procedure Analyze_Selected_Component (N : Node_Id) is
3538 Name : constant Node_Id := Prefix (N);
3539 Sel : constant Node_Id := Selector_Name (N);
3542 Has_Candidate : Boolean := False;
3545 Pent : Entity_Id := Empty;
3546 Prefix_Type : Entity_Id;
3548 Type_To_Use : Entity_Id;
3549 -- In most cases this is the Prefix_Type, but if the Prefix_Type is
3550 -- a class-wide type, we use its root type, whose components are
3551 -- present in the class-wide type.
3553 Is_Single_Concurrent_Object : Boolean;
3554 -- Set True if the prefix is a single task or a single protected object
3556 procedure Find_Component_In_Instance (Rec : Entity_Id);
3557 -- In an instance, a component of a private extension may not be visible
3558 -- while it was visible in the generic. Search candidate scope for a
3559 -- component with the proper identifier. This is only done if all other
3560 -- searches have failed. When the match is found (it always will be),
3561 -- the Etype of both N and Sel are set from this component, and the
3562 -- entity of Sel is set to reference this component.
3564 function Has_Mode_Conformant_Spec (Comp : Entity_Id) return Boolean;
3565 -- It is known that the parent of N denotes a subprogram call. Comp
3566 -- is an overloadable component of the concurrent type of the prefix.
3567 -- Determine whether all formals of the parent of N and Comp are mode
3568 -- conformant. If the parent node is not analyzed yet it may be an
3569 -- indexed component rather than a function call.
3571 --------------------------------
3572 -- Find_Component_In_Instance --
3573 --------------------------------
3575 procedure Find_Component_In_Instance (Rec : Entity_Id) is
3579 Comp := First_Component (Rec);
3580 while Present (Comp) loop
3581 if Chars (Comp) = Chars (Sel) then
3582 Set_Entity_With_Style_Check (Sel, Comp);
3583 Set_Etype (Sel, Etype (Comp));
3584 Set_Etype (N, Etype (Comp));
3588 Next_Component (Comp);
3591 -- This must succeed because code was legal in the generic
3593 raise Program_Error;
3594 end Find_Component_In_Instance;
3596 ------------------------------
3597 -- Has_Mode_Conformant_Spec --
3598 ------------------------------
3600 function Has_Mode_Conformant_Spec (Comp : Entity_Id) return Boolean is
3601 Comp_Param : Entity_Id;
3603 Param_Typ : Entity_Id;
3606 Comp_Param := First_Formal (Comp);
3608 if Nkind (Parent (N)) = N_Indexed_Component then
3609 Param := First (Expressions (Parent (N)));
3611 Param := First (Parameter_Associations (Parent (N)));
3614 while Present (Comp_Param)
3615 and then Present (Param)
3617 Param_Typ := Find_Parameter_Type (Param);
3619 if Present (Param_Typ)
3621 not Conforming_Types
3622 (Etype (Comp_Param), Param_Typ, Mode_Conformant)
3627 Next_Formal (Comp_Param);
3631 -- One of the specs has additional formals
3633 if Present (Comp_Param) or else Present (Param) then
3638 end Has_Mode_Conformant_Spec;
3640 -- Start of processing for Analyze_Selected_Component
3643 Set_Etype (N, Any_Type);
3645 if Is_Overloaded (Name) then
3646 Analyze_Overloaded_Selected_Component (N);
3649 elsif Etype (Name) = Any_Type then
3650 Set_Entity (Sel, Any_Id);
3651 Set_Etype (Sel, Any_Type);
3655 Prefix_Type := Etype (Name);
3658 if Is_Access_Type (Prefix_Type) then
3660 -- A RACW object can never be used as prefix of a selected component
3661 -- since that means it is dereferenced without being a controlling
3662 -- operand of a dispatching operation (RM E.2.2(16/1)). Before
3663 -- reporting an error, we must check whether this is actually a
3664 -- dispatching call in prefix form.
3666 if Is_Remote_Access_To_Class_Wide_Type (Prefix_Type)
3667 and then Comes_From_Source (N)
3669 if Try_Object_Operation (N) then
3673 ("invalid dereference of a remote access-to-class-wide value",
3677 -- Normal case of selected component applied to access type
3680 Error_Msg_NW (Warn_On_Dereference, "?implicit dereference", N);
3682 if Is_Entity_Name (Name) then
3683 Pent := Entity (Name);
3684 elsif Nkind (Name) = N_Selected_Component
3685 and then Is_Entity_Name (Selector_Name (Name))
3687 Pent := Entity (Selector_Name (Name));
3690 Prefix_Type := Process_Implicit_Dereference_Prefix (Pent, Name);
3693 -- If we have an explicit dereference of a remote access-to-class-wide
3694 -- value, then issue an error (see RM-E.2.2(16/1)). However we first
3695 -- have to check for the case of a prefix that is a controlling operand
3696 -- of a prefixed dispatching call, as the dereference is legal in that
3697 -- case. Normally this condition is checked in Validate_Remote_Access_
3698 -- To_Class_Wide_Type, but we have to defer the checking for selected
3699 -- component prefixes because of the prefixed dispatching call case.
3700 -- Note that implicit dereferences are checked for this just above.
3702 elsif Nkind (Name) = N_Explicit_Dereference
3703 and then Is_Remote_Access_To_Class_Wide_Type (Etype (Prefix (Name)))
3704 and then Comes_From_Source (N)
3706 if Try_Object_Operation (N) then
3710 ("invalid dereference of a remote access-to-class-wide value",
3715 -- (Ada 2005): if the prefix is the limited view of a type, and
3716 -- the context already includes the full view, use the full view
3717 -- in what follows, either to retrieve a component of to find
3718 -- a primitive operation. If the prefix is an explicit dereference,
3719 -- set the type of the prefix to reflect this transformation.
3720 -- If the non-limited view is itself an incomplete type, get the
3721 -- full view if available.
3723 if Is_Incomplete_Type (Prefix_Type)
3724 and then From_With_Type (Prefix_Type)
3725 and then Present (Non_Limited_View (Prefix_Type))
3727 Prefix_Type := Get_Full_View (Non_Limited_View (Prefix_Type));
3729 if Nkind (N) = N_Explicit_Dereference then
3730 Set_Etype (Prefix (N), Prefix_Type);
3733 elsif Ekind (Prefix_Type) = E_Class_Wide_Type
3734 and then From_With_Type (Prefix_Type)
3735 and then Present (Non_Limited_View (Etype (Prefix_Type)))
3738 Class_Wide_Type (Non_Limited_View (Etype (Prefix_Type)));
3740 if Nkind (N) = N_Explicit_Dereference then
3741 Set_Etype (Prefix (N), Prefix_Type);
3745 if Ekind (Prefix_Type) = E_Private_Subtype then
3746 Prefix_Type := Base_Type (Prefix_Type);
3749 Type_To_Use := Prefix_Type;
3751 -- For class-wide types, use the entity list of the root type. This
3752 -- indirection is specially important for private extensions because
3753 -- only the root type get switched (not the class-wide type).
3755 if Is_Class_Wide_Type (Prefix_Type) then
3756 Type_To_Use := Root_Type (Prefix_Type);
3759 -- If the prefix is a single concurrent object, use its name in error
3760 -- messages, rather than that of its anonymous type.
3762 Is_Single_Concurrent_Object :=
3763 Is_Concurrent_Type (Prefix_Type)
3764 and then Is_Internal_Name (Chars (Prefix_Type))
3765 and then not Is_Derived_Type (Prefix_Type)
3766 and then Is_Entity_Name (Name);
3768 Comp := First_Entity (Type_To_Use);
3770 -- If the selector has an original discriminant, the node appears in
3771 -- an instance. Replace the discriminant with the corresponding one
3772 -- in the current discriminated type. For nested generics, this must
3773 -- be done transitively, so note the new original discriminant.
3775 if Nkind (Sel) = N_Identifier
3776 and then In_Instance
3777 and then Present (Original_Discriminant (Sel))
3779 Comp := Find_Corresponding_Discriminant (Sel, Prefix_Type);
3781 -- Mark entity before rewriting, for completeness and because
3782 -- subsequent semantic checks might examine the original node.
3784 Set_Entity (Sel, Comp);
3785 Rewrite (Selector_Name (N),
3786 New_Occurrence_Of (Comp, Sloc (N)));
3787 Set_Original_Discriminant (Selector_Name (N), Comp);
3788 Set_Etype (N, Etype (Comp));
3790 if Is_Access_Type (Etype (Name)) then
3791 Insert_Explicit_Dereference (Name);
3792 Error_Msg_NW (Warn_On_Dereference, "?implicit dereference", N);
3795 elsif Is_Record_Type (Prefix_Type) then
3797 -- Find component with given name
3799 while Present (Comp) loop
3800 if Chars (Comp) = Chars (Sel)
3801 and then Is_Visible_Component (Comp)
3803 Set_Entity_With_Style_Check (Sel, Comp);
3804 Set_Etype (Sel, Etype (Comp));
3806 if Ekind (Comp) = E_Discriminant then
3807 if Is_Unchecked_Union (Base_Type (Prefix_Type)) then
3809 ("cannot reference discriminant of Unchecked_Union",
3813 if Is_Generic_Type (Prefix_Type)
3815 Is_Generic_Type (Root_Type (Prefix_Type))
3817 Set_Original_Discriminant (Sel, Comp);
3821 -- Resolve the prefix early otherwise it is not possible to
3822 -- build the actual subtype of the component: it may need
3823 -- to duplicate this prefix and duplication is only allowed
3824 -- on fully resolved expressions.
3828 -- Ada 2005 (AI-50217): Check wrong use of incomplete types or
3829 -- subtypes in a package specification.
3832 -- limited with Pkg;
3834 -- type Acc_Inc is access Pkg.T;
3836 -- N : Natural := X.all.Comp; -- ERROR, limited view
3837 -- end Pkg; -- Comp is not visible
3839 if Nkind (Name) = N_Explicit_Dereference
3840 and then From_With_Type (Etype (Prefix (Name)))
3841 and then not Is_Potentially_Use_Visible (Etype (Name))
3842 and then Nkind (Parent (Cunit_Entity (Current_Sem_Unit))) =
3843 N_Package_Specification
3846 ("premature usage of incomplete}", Prefix (Name),
3847 Etype (Prefix (Name)));
3850 -- We never need an actual subtype for the case of a selection
3851 -- for a indexed component of a non-packed array, since in
3852 -- this case gigi generates all the checks and can find the
3853 -- necessary bounds information.
3855 -- We also do not need an actual subtype for the case of a
3856 -- first, last, length, or range attribute applied to a
3857 -- non-packed array, since gigi can again get the bounds in
3858 -- these cases (gigi cannot handle the packed case, since it
3859 -- has the bounds of the packed array type, not the original
3860 -- bounds of the type). However, if the prefix is itself a
3861 -- selected component, as in a.b.c (i), gigi may regard a.b.c
3862 -- as a dynamic-sized temporary, so we do generate an actual
3863 -- subtype for this case.
3865 Parent_N := Parent (N);
3867 if not Is_Packed (Etype (Comp))
3869 ((Nkind (Parent_N) = N_Indexed_Component
3870 and then Nkind (Name) /= N_Selected_Component)
3872 (Nkind (Parent_N) = N_Attribute_Reference
3873 and then (Attribute_Name (Parent_N) = Name_First
3875 Attribute_Name (Parent_N) = Name_Last
3877 Attribute_Name (Parent_N) = Name_Length
3879 Attribute_Name (Parent_N) = Name_Range)))
3881 Set_Etype (N, Etype (Comp));
3883 -- If full analysis is not enabled, we do not generate an
3884 -- actual subtype, because in the absence of expansion
3885 -- reference to a formal of a protected type, for example,
3886 -- will not be properly transformed, and will lead to
3887 -- out-of-scope references in gigi.
3889 -- In all other cases, we currently build an actual subtype.
3890 -- It seems likely that many of these cases can be avoided,
3891 -- but right now, the front end makes direct references to the
3892 -- bounds (e.g. in generating a length check), and if we do
3893 -- not make an actual subtype, we end up getting a direct
3894 -- reference to a discriminant, which will not do.
3896 elsif Full_Analysis then
3898 Build_Actual_Subtype_Of_Component (Etype (Comp), N);
3899 Insert_Action (N, Act_Decl);
3901 if No (Act_Decl) then
3902 Set_Etype (N, Etype (Comp));
3905 -- Component type depends on discriminants. Enter the
3906 -- main attributes of the subtype.
3909 Subt : constant Entity_Id :=
3910 Defining_Identifier (Act_Decl);
3913 Set_Etype (Subt, Base_Type (Etype (Comp)));
3914 Set_Ekind (Subt, Ekind (Etype (Comp)));
3915 Set_Etype (N, Subt);
3919 -- If Full_Analysis not enabled, just set the Etype
3922 Set_Etype (N, Etype (Comp));
3928 -- If the prefix is a private extension, check only the visible
3929 -- components of the partial view. This must include the tag,
3930 -- which can appear in expanded code in a tag check.
3932 if Ekind (Type_To_Use) = E_Record_Type_With_Private
3933 and then Chars (Selector_Name (N)) /= Name_uTag
3935 exit when Comp = Last_Entity (Type_To_Use);
3941 -- Ada 2005 (AI-252): The selected component can be interpreted as
3942 -- a prefixed view of a subprogram. Depending on the context, this is
3943 -- either a name that can appear in a renaming declaration, or part
3944 -- of an enclosing call given in prefix form.
3946 -- Ada 2005 (AI05-0030): In the case of dispatching requeue, the
3947 -- selected component should resolve to a name.
3949 if Ada_Version >= Ada_2005
3950 and then Is_Tagged_Type (Prefix_Type)
3951 and then not Is_Concurrent_Type (Prefix_Type)
3953 if Nkind (Parent (N)) = N_Generic_Association
3954 or else Nkind (Parent (N)) = N_Requeue_Statement
3955 or else Nkind (Parent (N)) = N_Subprogram_Renaming_Declaration
3957 if Find_Primitive_Operation (N) then
3961 elsif Try_Object_Operation (N) then
3965 -- If the transformation fails, it will be necessary to redo the
3966 -- analysis with all errors enabled, to indicate candidate
3967 -- interpretations and reasons for each failure ???
3971 elsif Is_Private_Type (Prefix_Type) then
3973 -- Allow access only to discriminants of the type. If the type has
3974 -- no full view, gigi uses the parent type for the components, so we
3975 -- do the same here.
3977 if No (Full_View (Prefix_Type)) then
3978 Type_To_Use := Root_Type (Base_Type (Prefix_Type));
3979 Comp := First_Entity (Type_To_Use);
3982 while Present (Comp) loop
3983 if Chars (Comp) = Chars (Sel) then
3984 if Ekind (Comp) = E_Discriminant then
3985 Set_Entity_With_Style_Check (Sel, Comp);
3986 Generate_Reference (Comp, Sel);
3988 Set_Etype (Sel, Etype (Comp));
3989 Set_Etype (N, Etype (Comp));
3991 if Is_Generic_Type (Prefix_Type)
3992 or else Is_Generic_Type (Root_Type (Prefix_Type))
3994 Set_Original_Discriminant (Sel, Comp);
3997 -- Before declaring an error, check whether this is tagged
3998 -- private type and a call to a primitive operation.
4000 elsif Ada_Version >= Ada_2005
4001 and then Is_Tagged_Type (Prefix_Type)
4002 and then Try_Object_Operation (N)
4007 Error_Msg_Node_2 := First_Subtype (Prefix_Type);
4008 Error_Msg_NE ("invisible selector& for }", N, Sel);
4009 Set_Entity (Sel, Any_Id);
4010 Set_Etype (N, Any_Type);
4019 elsif Is_Concurrent_Type (Prefix_Type) then
4021 -- Find visible operation with given name. For a protected type,
4022 -- the possible candidates are discriminants, entries or protected
4023 -- procedures. For a task type, the set can only include entries or
4024 -- discriminants if the task type is not an enclosing scope. If it
4025 -- is an enclosing scope (e.g. in an inner task) then all entities
4026 -- are visible, but the prefix must denote the enclosing scope, i.e.
4027 -- can only be a direct name or an expanded name.
4029 Set_Etype (Sel, Any_Type);
4030 In_Scope := In_Open_Scopes (Prefix_Type);
4032 while Present (Comp) loop
4033 if Chars (Comp) = Chars (Sel) then
4034 if Is_Overloadable (Comp) then
4035 Add_One_Interp (Sel, Comp, Etype (Comp));
4037 -- If the prefix is tagged, the correct interpretation may
4038 -- lie in the primitive or class-wide operations of the
4039 -- type. Perform a simple conformance check to determine
4040 -- whether Try_Object_Operation should be invoked even if
4041 -- a visible entity is found.
4043 if Is_Tagged_Type (Prefix_Type)
4045 Nkind_In (Parent (N), N_Procedure_Call_Statement,
4047 N_Indexed_Component)
4048 and then Has_Mode_Conformant_Spec (Comp)
4050 Has_Candidate := True;
4053 -- Note: a selected component may not denote a component of a
4054 -- protected type (4.1.3(7)).
4056 elsif Ekind_In (Comp, E_Discriminant, E_Entry_Family)
4058 and then not Is_Protected_Type (Prefix_Type)
4059 and then Is_Entity_Name (Name))
4061 Set_Entity_With_Style_Check (Sel, Comp);
4062 Generate_Reference (Comp, Sel);
4068 Set_Etype (Sel, Etype (Comp));
4069 Set_Etype (N, Etype (Comp));
4071 if Ekind (Comp) = E_Discriminant then
4072 Set_Original_Discriminant (Sel, Comp);
4075 -- For access type case, introduce explicit dereference for
4076 -- more uniform treatment of entry calls.
4078 if Is_Access_Type (Etype (Name)) then
4079 Insert_Explicit_Dereference (Name);
4081 (Warn_On_Dereference, "?implicit dereference", N);
4087 exit when not In_Scope
4089 Comp = First_Private_Entity (Base_Type (Prefix_Type));
4092 -- If there is no visible entity with the given name or none of the
4093 -- visible entities are plausible interpretations, check whether
4094 -- there is some other primitive operation with that name.
4096 if Ada_Version >= Ada_2005
4097 and then Is_Tagged_Type (Prefix_Type)
4099 if (Etype (N) = Any_Type
4100 or else not Has_Candidate)
4101 and then Try_Object_Operation (N)
4105 -- If the context is not syntactically a procedure call, it
4106 -- may be a call to a primitive function declared outside of
4107 -- the synchronized type.
4109 -- If the context is a procedure call, there might still be
4110 -- an overloading between an entry and a primitive procedure
4111 -- declared outside of the synchronized type, called in prefix
4112 -- notation. This is harder to disambiguate because in one case
4113 -- the controlling formal is implicit ???
4115 elsif Nkind (Parent (N)) /= N_Procedure_Call_Statement
4116 and then Nkind (Parent (N)) /= N_Indexed_Component
4117 and then Try_Object_Operation (N)
4123 if Etype (N) = Any_Type and then Is_Protected_Type (Prefix_Type) then
4124 -- Case of a prefix of a protected type: selector might denote
4125 -- an invisible private component.
4127 Comp := First_Private_Entity (Base_Type (Prefix_Type));
4128 while Present (Comp) and then Chars (Comp) /= Chars (Sel) loop
4132 if Present (Comp) then
4133 if Is_Single_Concurrent_Object then
4134 Error_Msg_Node_2 := Entity (Name);
4135 Error_Msg_NE ("invisible selector& for &", N, Sel);
4138 Error_Msg_Node_2 := First_Subtype (Prefix_Type);
4139 Error_Msg_NE ("invisible selector& for }", N, Sel);
4145 Set_Is_Overloaded (N, Is_Overloaded (Sel));
4150 Error_Msg_NE ("invalid prefix in selected component&", N, Sel);
4153 -- If N still has no type, the component is not defined in the prefix
4155 if Etype (N) = Any_Type then
4157 if Is_Single_Concurrent_Object then
4158 Error_Msg_Node_2 := Entity (Name);
4159 Error_Msg_NE ("no selector& for&", N, Sel);
4161 Check_Misspelled_Selector (Type_To_Use, Sel);
4163 elsif Is_Generic_Type (Prefix_Type)
4164 and then Ekind (Prefix_Type) = E_Record_Type_With_Private
4165 and then Prefix_Type /= Etype (Prefix_Type)
4166 and then Is_Record_Type (Etype (Prefix_Type))
4168 -- If this is a derived formal type, the parent may have
4169 -- different visibility at this point. Try for an inherited
4170 -- component before reporting an error.
4172 Set_Etype (Prefix (N), Etype (Prefix_Type));
4173 Analyze_Selected_Component (N);
4176 -- Similarly, if this is the actual for a formal derived type, the
4177 -- component inherited from the generic parent may not be visible
4178 -- in the actual, but the selected component is legal.
4180 elsif Ekind (Prefix_Type) = E_Record_Subtype_With_Private
4181 and then Is_Generic_Actual_Type (Prefix_Type)
4182 and then Present (Full_View (Prefix_Type))
4185 Find_Component_In_Instance
4186 (Generic_Parent_Type (Parent (Prefix_Type)));
4189 -- Finally, the formal and the actual may be private extensions,
4190 -- but the generic is declared in a child unit of the parent, and
4191 -- an additional step is needed to retrieve the proper scope.
4194 and then Present (Parent_Subtype (Etype (Base_Type (Prefix_Type))))
4196 Find_Component_In_Instance
4197 (Parent_Subtype (Etype (Base_Type (Prefix_Type))));
4200 -- Component not found, specialize error message when appropriate
4203 if Ekind (Prefix_Type) = E_Record_Subtype then
4205 -- Check whether this is a component of the base type which
4206 -- is absent from a statically constrained subtype. This will
4207 -- raise constraint error at run time, but is not a compile-
4208 -- time error. When the selector is illegal for base type as
4209 -- well fall through and generate a compilation error anyway.
4211 Comp := First_Component (Base_Type (Prefix_Type));
4212 while Present (Comp) loop
4213 if Chars (Comp) = Chars (Sel)
4214 and then Is_Visible_Component (Comp)
4216 Set_Entity_With_Style_Check (Sel, Comp);
4217 Generate_Reference (Comp, Sel);
4218 Set_Etype (Sel, Etype (Comp));
4219 Set_Etype (N, Etype (Comp));
4221 -- Emit appropriate message. Gigi will replace the
4222 -- node subsequently with the appropriate Raise.
4224 Apply_Compile_Time_Constraint_Error
4225 (N, "component not present in }?",
4226 CE_Discriminant_Check_Failed,
4227 Ent => Prefix_Type, Rep => False);
4228 Set_Raises_Constraint_Error (N);
4232 Next_Component (Comp);
4237 Error_Msg_Node_2 := First_Subtype (Prefix_Type);
4238 Error_Msg_NE ("no selector& for}", N, Sel);
4240 Check_Misspelled_Selector (Type_To_Use, Sel);
4243 Set_Entity (Sel, Any_Id);
4244 Set_Etype (Sel, Any_Type);
4246 end Analyze_Selected_Component;
4248 ---------------------------
4249 -- Analyze_Short_Circuit --
4250 ---------------------------
4252 procedure Analyze_Short_Circuit (N : Node_Id) is
4253 L : constant Node_Id := Left_Opnd (N);
4254 R : constant Node_Id := Right_Opnd (N);
4259 Analyze_Expression (L);
4260 Analyze_Expression (R);
4261 Set_Etype (N, Any_Type);
4263 if not Is_Overloaded (L) then
4264 if Root_Type (Etype (L)) = Standard_Boolean
4265 and then Has_Compatible_Type (R, Etype (L))
4267 Add_One_Interp (N, Etype (L), Etype (L));
4271 Get_First_Interp (L, Ind, It);
4272 while Present (It.Typ) loop
4273 if Root_Type (It.Typ) = Standard_Boolean
4274 and then Has_Compatible_Type (R, It.Typ)
4276 Add_One_Interp (N, It.Typ, It.Typ);
4279 Get_Next_Interp (Ind, It);
4283 -- Here we have failed to find an interpretation. Clearly we know that
4284 -- it is not the case that both operands can have an interpretation of
4285 -- Boolean, but this is by far the most likely intended interpretation.
4286 -- So we simply resolve both operands as Booleans, and at least one of
4287 -- these resolutions will generate an error message, and we do not need
4288 -- to give another error message on the short circuit operation itself.
4290 if Etype (N) = Any_Type then
4291 Resolve (L, Standard_Boolean);
4292 Resolve (R, Standard_Boolean);
4293 Set_Etype (N, Standard_Boolean);
4295 end Analyze_Short_Circuit;
4301 procedure Analyze_Slice (N : Node_Id) is
4302 P : constant Node_Id := Prefix (N);
4303 D : constant Node_Id := Discrete_Range (N);
4304 Array_Type : Entity_Id;
4306 procedure Analyze_Overloaded_Slice;
4307 -- If the prefix is overloaded, select those interpretations that
4308 -- yield a one-dimensional array type.
4310 ------------------------------
4311 -- Analyze_Overloaded_Slice --
4312 ------------------------------
4314 procedure Analyze_Overloaded_Slice is
4320 Set_Etype (N, Any_Type);
4322 Get_First_Interp (P, I, It);
4323 while Present (It.Nam) loop
4326 if Is_Access_Type (Typ) then
4327 Typ := Designated_Type (Typ);
4328 Error_Msg_NW (Warn_On_Dereference, "?implicit dereference", N);
4331 if Is_Array_Type (Typ)
4332 and then Number_Dimensions (Typ) = 1
4333 and then Has_Compatible_Type (D, Etype (First_Index (Typ)))
4335 Add_One_Interp (N, Typ, Typ);
4338 Get_Next_Interp (I, It);
4341 if Etype (N) = Any_Type then
4342 Error_Msg_N ("expect array type in prefix of slice", N);
4344 end Analyze_Overloaded_Slice;
4346 -- Start of processing for Analyze_Slice
4349 Mark_Non_ALFA_Subprogram;
4350 Check_SPARK_Restriction ("slice is not allowed", N);
4355 if Is_Overloaded (P) then
4356 Analyze_Overloaded_Slice;
4359 Array_Type := Etype (P);
4360 Set_Etype (N, Any_Type);
4362 if Is_Access_Type (Array_Type) then
4363 Array_Type := Designated_Type (Array_Type);
4364 Error_Msg_NW (Warn_On_Dereference, "?implicit dereference", N);
4367 if not Is_Array_Type (Array_Type) then
4368 Wrong_Type (P, Any_Array);
4370 elsif Number_Dimensions (Array_Type) > 1 then
4372 ("type is not one-dimensional array in slice prefix", N);
4375 Has_Compatible_Type (D, Etype (First_Index (Array_Type)))
4377 Wrong_Type (D, Etype (First_Index (Array_Type)));
4380 Set_Etype (N, Array_Type);
4385 -----------------------------
4386 -- Analyze_Type_Conversion --
4387 -----------------------------
4389 procedure Analyze_Type_Conversion (N : Node_Id) is
4390 Expr : constant Node_Id := Expression (N);
4394 -- If Conversion_OK is set, then the Etype is already set, and the
4395 -- only processing required is to analyze the expression. This is
4396 -- used to construct certain "illegal" conversions which are not
4397 -- allowed by Ada semantics, but can be handled OK by Gigi, see
4398 -- Sinfo for further details.
4400 if Conversion_OK (N) then
4405 -- Otherwise full type analysis is required, as well as some semantic
4406 -- checks to make sure the argument of the conversion is appropriate.
4408 Find_Type (Subtype_Mark (N));
4409 T := Entity (Subtype_Mark (N));
4411 Check_Fully_Declared (T, N);
4412 Analyze_Expression (Expr);
4413 Validate_Remote_Type_Type_Conversion (N);
4415 -- Type conversion between scalar types are allowed in ALFA. All other
4416 -- type conversions are not allowed.
4418 if not (Is_Scalar_Type (Etype (Expr)) and then Is_Scalar_Type (T)) then
4419 Mark_Non_ALFA_Subprogram;
4422 -- Only remaining step is validity checks on the argument. These
4423 -- are skipped if the conversion does not come from the source.
4425 if not Comes_From_Source (N) then
4428 -- If there was an error in a generic unit, no need to replicate the
4429 -- error message. Conversely, constant-folding in the generic may
4430 -- transform the argument of a conversion into a string literal, which
4431 -- is legal. Therefore the following tests are not performed in an
4434 elsif In_Instance then
4437 elsif Nkind (Expr) = N_Null then
4438 Error_Msg_N ("argument of conversion cannot be null", N);
4439 Error_Msg_N ("\use qualified expression instead", N);
4440 Set_Etype (N, Any_Type);
4442 elsif Nkind (Expr) = N_Aggregate then
4443 Error_Msg_N ("argument of conversion cannot be aggregate", N);
4444 Error_Msg_N ("\use qualified expression instead", N);
4446 elsif Nkind (Expr) = N_Allocator then
4447 Error_Msg_N ("argument of conversion cannot be an allocator", N);
4448 Error_Msg_N ("\use qualified expression instead", N);
4450 elsif Nkind (Expr) = N_String_Literal then
4451 Error_Msg_N ("argument of conversion cannot be string literal", N);
4452 Error_Msg_N ("\use qualified expression instead", N);
4454 elsif Nkind (Expr) = N_Character_Literal then
4455 if Ada_Version = Ada_83 then
4458 Error_Msg_N ("argument of conversion cannot be character literal",
4460 Error_Msg_N ("\use qualified expression instead", N);
4463 elsif Nkind (Expr) = N_Attribute_Reference
4465 (Attribute_Name (Expr) = Name_Access or else
4466 Attribute_Name (Expr) = Name_Unchecked_Access or else
4467 Attribute_Name (Expr) = Name_Unrestricted_Access)
4469 Error_Msg_N ("argument of conversion cannot be access", N);
4470 Error_Msg_N ("\use qualified expression instead", N);
4472 end Analyze_Type_Conversion;
4474 ----------------------
4475 -- Analyze_Unary_Op --
4476 ----------------------
4478 procedure Analyze_Unary_Op (N : Node_Id) is
4479 R : constant Node_Id := Right_Opnd (N);
4480 Op_Id : Entity_Id := Entity (N);
4483 Set_Etype (N, Any_Type);
4484 Candidate_Type := Empty;
4486 Analyze_Expression (R);
4488 if Present (Op_Id) then
4489 if Ekind (Op_Id) = E_Operator then
4490 Find_Unary_Types (R, Op_Id, N);
4492 Add_One_Interp (N, Op_Id, Etype (Op_Id));
4496 Op_Id := Get_Name_Entity_Id (Chars (N));
4497 while Present (Op_Id) loop
4498 if Ekind (Op_Id) = E_Operator then
4499 if No (Next_Entity (First_Entity (Op_Id))) then
4500 Find_Unary_Types (R, Op_Id, N);
4503 elsif Is_Overloadable (Op_Id) then
4504 Analyze_User_Defined_Unary_Op (N, Op_Id);
4507 Op_Id := Homonym (Op_Id);
4512 end Analyze_Unary_Op;
4514 ----------------------------------
4515 -- Analyze_Unchecked_Expression --
4516 ----------------------------------
4518 procedure Analyze_Unchecked_Expression (N : Node_Id) is
4520 Analyze (Expression (N), Suppress => All_Checks);
4521 Set_Etype (N, Etype (Expression (N)));
4522 Save_Interps (Expression (N), N);
4523 end Analyze_Unchecked_Expression;
4525 ---------------------------------------
4526 -- Analyze_Unchecked_Type_Conversion --
4527 ---------------------------------------
4529 procedure Analyze_Unchecked_Type_Conversion (N : Node_Id) is
4531 Mark_Non_ALFA_Subprogram;
4532 Find_Type (Subtype_Mark (N));
4533 Analyze_Expression (Expression (N));
4534 Set_Etype (N, Entity (Subtype_Mark (N)));
4535 end Analyze_Unchecked_Type_Conversion;
4537 ------------------------------------
4538 -- Analyze_User_Defined_Binary_Op --
4539 ------------------------------------
4541 procedure Analyze_User_Defined_Binary_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 F1 : constant Entity_Id := First_Formal (Op_Id);
4553 F2 : constant Entity_Id := Next_Formal (F1);
4556 -- Verify that Op_Id is a visible binary function. Note that since
4557 -- we know Op_Id is overloaded, potentially use visible means use
4558 -- visible for sure (RM 9.4(11)).
4560 if Ekind (Op_Id) = E_Function
4561 and then Present (F2)
4562 and then (Is_Immediately_Visible (Op_Id)
4563 or else Is_Potentially_Use_Visible (Op_Id))
4564 and then Has_Compatible_Type (Left_Opnd (N), Etype (F1))
4565 and then Has_Compatible_Type (Right_Opnd (N), Etype (F2))
4567 Add_One_Interp (N, Op_Id, Etype (Op_Id));
4569 -- If the left operand is overloaded, indicate that the
4570 -- current type is a viable candidate. This is redundant
4571 -- in most cases, but for equality and comparison operators
4572 -- where the context does not impose a type on the operands,
4573 -- setting the proper type is necessary to avoid subsequent
4574 -- ambiguities during resolution, when both user-defined and
4575 -- predefined operators may be candidates.
4577 if Is_Overloaded (Left_Opnd (N)) then
4578 Set_Etype (Left_Opnd (N), Etype (F1));
4581 if Debug_Flag_E then
4582 Write_Str ("user defined operator ");
4583 Write_Name (Chars (Op_Id));
4584 Write_Str (" on node ");
4585 Write_Int (Int (N));
4591 end Analyze_User_Defined_Binary_Op;
4593 -----------------------------------
4594 -- Analyze_User_Defined_Unary_Op --
4595 -----------------------------------
4597 procedure Analyze_User_Defined_Unary_Op
4602 -- Only do analysis if the operator Comes_From_Source, since otherwise
4603 -- the operator was generated by the expander, and all such operators
4604 -- always refer to the operators in package Standard.
4606 if Comes_From_Source (N) then
4608 F : constant Entity_Id := First_Formal (Op_Id);
4611 -- Verify that Op_Id is a visible unary function. Note that since
4612 -- we know Op_Id is overloaded, potentially use visible means use
4613 -- visible for sure (RM 9.4(11)).
4615 if Ekind (Op_Id) = E_Function
4616 and then No (Next_Formal (F))
4617 and then (Is_Immediately_Visible (Op_Id)
4618 or else Is_Potentially_Use_Visible (Op_Id))
4619 and then Has_Compatible_Type (Right_Opnd (N), Etype (F))
4621 Add_One_Interp (N, Op_Id, Etype (Op_Id));
4625 end Analyze_User_Defined_Unary_Op;
4627 ---------------------------
4628 -- Check_Arithmetic_Pair --
4629 ---------------------------
4631 procedure Check_Arithmetic_Pair
4632 (T1, T2 : Entity_Id;
4636 Op_Name : constant Name_Id := Chars (Op_Id);
4638 function Has_Fixed_Op (Typ : Entity_Id; Op : Entity_Id) return Boolean;
4639 -- Check whether the fixed-point type Typ has a user-defined operator
4640 -- (multiplication or division) that should hide the corresponding
4641 -- predefined operator. Used to implement Ada 2005 AI-264, to make
4642 -- such operators more visible and therefore useful.
4644 -- If the name of the operation is an expanded name with prefix
4645 -- Standard, the predefined universal fixed operator is available,
4646 -- as specified by AI-420 (RM 4.5.5 (19.1/2)).
4648 function Specific_Type (T1, T2 : Entity_Id) return Entity_Id;
4649 -- Get specific type (i.e. non-universal type if there is one)
4655 function Has_Fixed_Op (Typ : Entity_Id; Op : Entity_Id) return Boolean is
4656 Bas : constant Entity_Id := Base_Type (Typ);
4662 -- If the universal_fixed operation is given explicitly the rule
4663 -- concerning primitive operations of the type do not apply.
4665 if Nkind (N) = N_Function_Call
4666 and then Nkind (Name (N)) = N_Expanded_Name
4667 and then Entity (Prefix (Name (N))) = Standard_Standard
4672 -- The operation is treated as primitive if it is declared in the
4673 -- same scope as the type, and therefore on the same entity chain.
4675 Ent := Next_Entity (Typ);
4676 while Present (Ent) loop
4677 if Chars (Ent) = Chars (Op) then
4678 F1 := First_Formal (Ent);
4679 F2 := Next_Formal (F1);
4681 -- The operation counts as primitive if either operand or
4682 -- result are of the given base type, and both operands are
4683 -- fixed point types.
4685 if (Base_Type (Etype (F1)) = Bas
4686 and then Is_Fixed_Point_Type (Etype (F2)))
4689 (Base_Type (Etype (F2)) = Bas
4690 and then Is_Fixed_Point_Type (Etype (F1)))
4693 (Base_Type (Etype (Ent)) = Bas
4694 and then Is_Fixed_Point_Type (Etype (F1))
4695 and then Is_Fixed_Point_Type (Etype (F2)))
4711 function Specific_Type (T1, T2 : Entity_Id) return Entity_Id is
4713 if T1 = Universal_Integer or else T1 = Universal_Real then
4714 return Base_Type (T2);
4716 return Base_Type (T1);
4720 -- Start of processing for Check_Arithmetic_Pair
4723 if Op_Name = Name_Op_Add or else Op_Name = Name_Op_Subtract then
4725 if Is_Numeric_Type (T1)
4726 and then Is_Numeric_Type (T2)
4727 and then (Covers (T1 => T1, T2 => T2)
4729 Covers (T1 => T2, T2 => T1))
4731 Add_One_Interp (N, Op_Id, Specific_Type (T1, T2));
4734 elsif Op_Name = Name_Op_Multiply or else Op_Name = Name_Op_Divide then
4736 if Is_Fixed_Point_Type (T1)
4737 and then (Is_Fixed_Point_Type (T2)
4738 or else T2 = Universal_Real)
4740 -- If Treat_Fixed_As_Integer is set then the Etype is already set
4741 -- and no further processing is required (this is the case of an
4742 -- operator constructed by Exp_Fixd for a fixed point operation)
4743 -- Otherwise add one interpretation with universal fixed result
4744 -- If the operator is given in functional notation, it comes
4745 -- from source and Fixed_As_Integer cannot apply.
4747 if (Nkind (N) not in N_Op
4748 or else not Treat_Fixed_As_Integer (N))
4750 (not Has_Fixed_Op (T1, Op_Id)
4751 or else Nkind (Parent (N)) = N_Type_Conversion)
4753 Add_One_Interp (N, Op_Id, Universal_Fixed);
4756 elsif Is_Fixed_Point_Type (T2)
4757 and then (Nkind (N) not in N_Op
4758 or else not Treat_Fixed_As_Integer (N))
4759 and then T1 = Universal_Real
4761 (not Has_Fixed_Op (T1, Op_Id)
4762 or else Nkind (Parent (N)) = N_Type_Conversion)
4764 Add_One_Interp (N, Op_Id, Universal_Fixed);
4766 elsif Is_Numeric_Type (T1)
4767 and then Is_Numeric_Type (T2)
4768 and then (Covers (T1 => T1, T2 => T2)
4770 Covers (T1 => T2, T2 => T1))
4772 Add_One_Interp (N, Op_Id, Specific_Type (T1, T2));
4774 elsif Is_Fixed_Point_Type (T1)
4775 and then (Base_Type (T2) = Base_Type (Standard_Integer)
4776 or else T2 = Universal_Integer)
4778 Add_One_Interp (N, Op_Id, T1);
4780 elsif T2 = Universal_Real
4781 and then Base_Type (T1) = Base_Type (Standard_Integer)
4782 and then Op_Name = Name_Op_Multiply
4784 Add_One_Interp (N, Op_Id, Any_Fixed);
4786 elsif T1 = Universal_Real
4787 and then Base_Type (T2) = Base_Type (Standard_Integer)
4789 Add_One_Interp (N, Op_Id, Any_Fixed);
4791 elsif Is_Fixed_Point_Type (T2)
4792 and then (Base_Type (T1) = Base_Type (Standard_Integer)
4793 or else T1 = Universal_Integer)
4794 and then Op_Name = Name_Op_Multiply
4796 Add_One_Interp (N, Op_Id, T2);
4798 elsif T1 = Universal_Real and then T2 = Universal_Integer then
4799 Add_One_Interp (N, Op_Id, T1);
4801 elsif T2 = Universal_Real
4802 and then T1 = Universal_Integer
4803 and then Op_Name = Name_Op_Multiply
4805 Add_One_Interp (N, Op_Id, T2);
4808 elsif Op_Name = Name_Op_Mod or else Op_Name = Name_Op_Rem then
4810 -- Note: The fixed-point operands case with Treat_Fixed_As_Integer
4811 -- set does not require any special processing, since the Etype is
4812 -- already set (case of operation constructed by Exp_Fixed).
4814 if Is_Integer_Type (T1)
4815 and then (Covers (T1 => T1, T2 => T2)
4817 Covers (T1 => T2, T2 => T1))
4819 Add_One_Interp (N, Op_Id, Specific_Type (T1, T2));
4822 elsif Op_Name = Name_Op_Expon then
4823 if Is_Numeric_Type (T1)
4824 and then not Is_Fixed_Point_Type (T1)
4825 and then (Base_Type (T2) = Base_Type (Standard_Integer)
4826 or else T2 = Universal_Integer)
4828 Add_One_Interp (N, Op_Id, Base_Type (T1));
4831 else pragma Assert (Nkind (N) in N_Op_Shift);
4833 -- If not one of the predefined operators, the node may be one
4834 -- of the intrinsic functions. Its kind is always specific, and
4835 -- we can use it directly, rather than the name of the operation.
4837 if Is_Integer_Type (T1)
4838 and then (Base_Type (T2) = Base_Type (Standard_Integer)
4839 or else T2 = Universal_Integer)
4841 Add_One_Interp (N, Op_Id, Base_Type (T1));
4844 end Check_Arithmetic_Pair;
4846 -------------------------------
4847 -- Check_Misspelled_Selector --
4848 -------------------------------
4850 procedure Check_Misspelled_Selector
4851 (Prefix : Entity_Id;
4854 Max_Suggestions : constant := 2;
4855 Nr_Of_Suggestions : Natural := 0;
4857 Suggestion_1 : Entity_Id := Empty;
4858 Suggestion_2 : Entity_Id := Empty;
4863 -- All the components of the prefix of selector Sel are matched
4864 -- against Sel and a count is maintained of possible misspellings.
4865 -- When at the end of the analysis there are one or two (not more!)
4866 -- possible misspellings, these misspellings will be suggested as
4867 -- possible correction.
4869 if not (Is_Private_Type (Prefix) or else Is_Record_Type (Prefix)) then
4871 -- Concurrent types should be handled as well ???
4876 Comp := First_Entity (Prefix);
4877 while Nr_Of_Suggestions <= Max_Suggestions and then Present (Comp) loop
4878 if Is_Visible_Component (Comp) then
4879 if Is_Bad_Spelling_Of (Chars (Comp), Chars (Sel)) then
4880 Nr_Of_Suggestions := Nr_Of_Suggestions + 1;
4882 case Nr_Of_Suggestions is
4883 when 1 => Suggestion_1 := Comp;
4884 when 2 => Suggestion_2 := Comp;
4885 when others => exit;
4890 Comp := Next_Entity (Comp);
4893 -- Report at most two suggestions
4895 if Nr_Of_Suggestions = 1 then
4896 Error_Msg_NE -- CODEFIX
4897 ("\possible misspelling of&", Sel, Suggestion_1);
4899 elsif Nr_Of_Suggestions = 2 then
4900 Error_Msg_Node_2 := Suggestion_2;
4901 Error_Msg_NE -- CODEFIX
4902 ("\possible misspelling of& or&", Sel, Suggestion_1);
4904 end Check_Misspelled_Selector;
4906 ----------------------
4907 -- Defined_In_Scope --
4908 ----------------------
4910 function Defined_In_Scope (T : Entity_Id; S : Entity_Id) return Boolean
4912 S1 : constant Entity_Id := Scope (Base_Type (T));
4915 or else (S1 = System_Aux_Id and then S = Scope (S1));
4916 end Defined_In_Scope;
4922 procedure Diagnose_Call (N : Node_Id; Nam : Node_Id) is
4928 Void_Interp_Seen : Boolean := False;
4931 pragma Warnings (Off, Boolean);
4934 if Ada_Version >= Ada_2005 then
4935 Actual := First_Actual (N);
4936 while Present (Actual) loop
4938 -- Ada 2005 (AI-50217): Post an error in case of premature
4939 -- usage of an entity from the limited view.
4941 if not Analyzed (Etype (Actual))
4942 and then From_With_Type (Etype (Actual))
4944 Error_Msg_Qual_Level := 1;
4946 ("missing with_clause for scope of imported type&",
4947 Actual, Etype (Actual));
4948 Error_Msg_Qual_Level := 0;
4951 Next_Actual (Actual);
4955 -- Analyze each candidate call again, with full error reporting
4959 ("no candidate interpretations match the actuals:!", Nam);
4960 Err_Mode := All_Errors_Mode;
4961 All_Errors_Mode := True;
4963 -- If this is a call to an operation of a concurrent type,
4964 -- the failed interpretations have been removed from the
4965 -- name. Recover them to provide full diagnostics.
4967 if Nkind (Parent (Nam)) = N_Selected_Component then
4968 Set_Entity (Nam, Empty);
4969 New_Nam := New_Copy_Tree (Parent (Nam));
4970 Set_Is_Overloaded (New_Nam, False);
4971 Set_Is_Overloaded (Selector_Name (New_Nam), False);
4972 Set_Parent (New_Nam, Parent (Parent (Nam)));
4973 Analyze_Selected_Component (New_Nam);
4974 Get_First_Interp (Selector_Name (New_Nam), X, It);
4976 Get_First_Interp (Nam, X, It);
4979 while Present (It.Nam) loop
4980 if Etype (It.Nam) = Standard_Void_Type then
4981 Void_Interp_Seen := True;
4984 Analyze_One_Call (N, It.Nam, True, Success);
4985 Get_Next_Interp (X, It);
4988 if Nkind (N) = N_Function_Call then
4989 Get_First_Interp (Nam, X, It);
4990 while Present (It.Nam) loop
4991 if Ekind_In (It.Nam, E_Function, E_Operator) then
4994 Get_Next_Interp (X, It);
4998 -- If all interpretations are procedures, this deserves a
4999 -- more precise message. Ditto if this appears as the prefix
5000 -- of a selected component, which may be a lexical error.
5003 ("\context requires function call, found procedure name", Nam);
5005 if Nkind (Parent (N)) = N_Selected_Component
5006 and then N = Prefix (Parent (N))
5008 Error_Msg_N -- CODEFIX
5009 ("\period should probably be semicolon", Parent (N));
5012 elsif Nkind (N) = N_Procedure_Call_Statement
5013 and then not Void_Interp_Seen
5016 "\function name found in procedure call", Nam);
5019 All_Errors_Mode := Err_Mode;
5022 ---------------------------
5023 -- Find_Arithmetic_Types --
5024 ---------------------------
5026 procedure Find_Arithmetic_Types
5031 Index1 : Interp_Index;
5032 Index2 : Interp_Index;
5036 procedure Check_Right_Argument (T : Entity_Id);
5037 -- Check right operand of operator
5039 --------------------------
5040 -- Check_Right_Argument --
5041 --------------------------
5043 procedure Check_Right_Argument (T : Entity_Id) is
5045 if not Is_Overloaded (R) then
5046 Check_Arithmetic_Pair (T, Etype (R), Op_Id, N);
5048 Get_First_Interp (R, Index2, It2);
5049 while Present (It2.Typ) loop
5050 Check_Arithmetic_Pair (T, It2.Typ, Op_Id, N);
5051 Get_Next_Interp (Index2, It2);
5054 end Check_Right_Argument;
5056 -- Start of processing for Find_Arithmetic_Types
5059 if not Is_Overloaded (L) then
5060 Check_Right_Argument (Etype (L));
5063 Get_First_Interp (L, Index1, It1);
5064 while Present (It1.Typ) loop
5065 Check_Right_Argument (It1.Typ);
5066 Get_Next_Interp (Index1, It1);
5070 end Find_Arithmetic_Types;
5072 ------------------------
5073 -- Find_Boolean_Types --
5074 ------------------------
5076 procedure Find_Boolean_Types
5081 Index : Interp_Index;
5084 procedure Check_Numeric_Argument (T : Entity_Id);
5085 -- Special case for logical operations one of whose operands is an
5086 -- integer literal. If both are literal the result is any modular type.
5088 ----------------------------
5089 -- Check_Numeric_Argument --
5090 ----------------------------
5092 procedure Check_Numeric_Argument (T : Entity_Id) is
5094 if T = Universal_Integer then
5095 Add_One_Interp (N, Op_Id, Any_Modular);
5097 elsif Is_Modular_Integer_Type (T) then
5098 Add_One_Interp (N, Op_Id, T);
5100 end Check_Numeric_Argument;
5102 -- Start of processing for Find_Boolean_Types
5105 if not Is_Overloaded (L) then
5106 if Etype (L) = Universal_Integer
5107 or else Etype (L) = Any_Modular
5109 if not Is_Overloaded (R) then
5110 Check_Numeric_Argument (Etype (R));
5113 Get_First_Interp (R, Index, It);
5114 while Present (It.Typ) loop
5115 Check_Numeric_Argument (It.Typ);
5116 Get_Next_Interp (Index, It);
5120 -- If operands are aggregates, we must assume that they may be
5121 -- boolean arrays, and leave disambiguation for the second pass.
5122 -- If only one is an aggregate, verify that the other one has an
5123 -- interpretation as a boolean array
5125 elsif Nkind (L) = N_Aggregate then
5126 if Nkind (R) = N_Aggregate then
5127 Add_One_Interp (N, Op_Id, Etype (L));
5129 elsif not Is_Overloaded (R) then
5130 if Valid_Boolean_Arg (Etype (R)) then
5131 Add_One_Interp (N, Op_Id, Etype (R));
5135 Get_First_Interp (R, Index, It);
5136 while Present (It.Typ) loop
5137 if Valid_Boolean_Arg (It.Typ) then
5138 Add_One_Interp (N, Op_Id, It.Typ);
5141 Get_Next_Interp (Index, It);
5145 elsif Valid_Boolean_Arg (Etype (L))
5146 and then Has_Compatible_Type (R, Etype (L))
5148 Add_One_Interp (N, Op_Id, Etype (L));
5152 Get_First_Interp (L, Index, It);
5153 while Present (It.Typ) loop
5154 if Valid_Boolean_Arg (It.Typ)
5155 and then Has_Compatible_Type (R, It.Typ)
5157 Add_One_Interp (N, Op_Id, It.Typ);
5160 Get_Next_Interp (Index, It);
5163 end Find_Boolean_Types;
5165 ---------------------------
5166 -- Find_Comparison_Types --
5167 ---------------------------
5169 procedure Find_Comparison_Types
5174 Index : Interp_Index;
5176 Found : Boolean := False;
5179 Scop : Entity_Id := Empty;
5181 procedure Try_One_Interp (T1 : Entity_Id);
5182 -- Routine to try one proposed interpretation. Note that the context
5183 -- of the operator plays no role in resolving the arguments, so that
5184 -- if there is more than one interpretation of the operands that is
5185 -- compatible with comparison, the operation is ambiguous.
5187 --------------------
5188 -- Try_One_Interp --
5189 --------------------
5191 procedure Try_One_Interp (T1 : Entity_Id) is
5194 -- If the operator is an expanded name, then the type of the operand
5195 -- must be defined in the corresponding scope. If the type is
5196 -- universal, the context will impose the correct type.
5199 and then not Defined_In_Scope (T1, Scop)
5200 and then T1 /= Universal_Integer
5201 and then T1 /= Universal_Real
5202 and then T1 /= Any_String
5203 and then T1 /= Any_Composite
5208 if Valid_Comparison_Arg (T1)
5209 and then Has_Compatible_Type (R, T1)
5212 and then Base_Type (T1) /= Base_Type (T_F)
5214 It := Disambiguate (L, I_F, Index, Any_Type);
5216 if It = No_Interp then
5217 Ambiguous_Operands (N);
5218 Set_Etype (L, Any_Type);
5232 Find_Non_Universal_Interpretations (N, R, Op_Id, T1);
5237 -- Start of processing for Find_Comparison_Types
5240 -- If left operand is aggregate, the right operand has to
5241 -- provide a usable type for it.
5243 if Nkind (L) = N_Aggregate
5244 and then Nkind (R) /= N_Aggregate
5246 Find_Comparison_Types (L => R, R => L, Op_Id => Op_Id, N => N);
5250 if Nkind (N) = N_Function_Call
5251 and then Nkind (Name (N)) = N_Expanded_Name
5253 Scop := Entity (Prefix (Name (N)));
5255 -- The prefix may be a package renaming, and the subsequent test
5256 -- requires the original package.
5258 if Ekind (Scop) = E_Package
5259 and then Present (Renamed_Entity (Scop))
5261 Scop := Renamed_Entity (Scop);
5262 Set_Entity (Prefix (Name (N)), Scop);
5266 if not Is_Overloaded (L) then
5267 Try_One_Interp (Etype (L));
5270 Get_First_Interp (L, Index, It);
5271 while Present (It.Typ) loop
5272 Try_One_Interp (It.Typ);
5273 Get_Next_Interp (Index, It);
5276 end Find_Comparison_Types;
5278 ----------------------------------------
5279 -- Find_Non_Universal_Interpretations --
5280 ----------------------------------------
5282 procedure Find_Non_Universal_Interpretations
5288 Index : Interp_Index;
5292 if T1 = Universal_Integer
5293 or else T1 = Universal_Real
5295 if not Is_Overloaded (R) then
5297 (N, Op_Id, Standard_Boolean, Base_Type (Etype (R)));
5299 Get_First_Interp (R, Index, It);
5300 while Present (It.Typ) loop
5301 if Covers (It.Typ, T1) then
5303 (N, Op_Id, Standard_Boolean, Base_Type (It.Typ));
5306 Get_Next_Interp (Index, It);
5310 Add_One_Interp (N, Op_Id, Standard_Boolean, Base_Type (T1));
5312 end Find_Non_Universal_Interpretations;
5314 ------------------------------
5315 -- Find_Concatenation_Types --
5316 ------------------------------
5318 procedure Find_Concatenation_Types
5323 Op_Type : constant Entity_Id := Etype (Op_Id);
5326 if Is_Array_Type (Op_Type)
5327 and then not Is_Limited_Type (Op_Type)
5329 and then (Has_Compatible_Type (L, Op_Type)
5331 Has_Compatible_Type (L, Component_Type (Op_Type)))
5333 and then (Has_Compatible_Type (R, Op_Type)
5335 Has_Compatible_Type (R, Component_Type (Op_Type)))
5337 Add_One_Interp (N, Op_Id, Op_Type);
5339 end Find_Concatenation_Types;
5341 -------------------------
5342 -- Find_Equality_Types --
5343 -------------------------
5345 procedure Find_Equality_Types
5350 Index : Interp_Index;
5352 Found : Boolean := False;
5355 Scop : Entity_Id := Empty;
5357 procedure Try_One_Interp (T1 : Entity_Id);
5358 -- The context of the equality operator plays no role in resolving the
5359 -- arguments, so that if there is more than one interpretation of the
5360 -- operands that is compatible with equality, the construct is ambiguous
5361 -- and an error can be emitted now, after trying to disambiguate, i.e.
5362 -- applying preference rules.
5364 --------------------
5365 -- Try_One_Interp --
5366 --------------------
5368 procedure Try_One_Interp (T1 : Entity_Id) is
5369 Bas : constant Entity_Id := Base_Type (T1);
5372 -- If the operator is an expanded name, then the type of the operand
5373 -- must be defined in the corresponding scope. If the type is
5374 -- universal, the context will impose the correct type. An anonymous
5375 -- type for a 'Access reference is also universal in this sense, as
5376 -- the actual type is obtained from context.
5377 -- In Ada 2005, the equality operator for anonymous access types
5378 -- is declared in Standard, and preference rules apply to it.
5380 if Present (Scop) then
5381 if Defined_In_Scope (T1, Scop)
5382 or else T1 = Universal_Integer
5383 or else T1 = Universal_Real
5384 or else T1 = Any_Access
5385 or else T1 = Any_String
5386 or else T1 = Any_Composite
5387 or else (Ekind (T1) = E_Access_Subprogram_Type
5388 and then not Comes_From_Source (T1))
5392 elsif Ekind (T1) = E_Anonymous_Access_Type
5393 and then Scop = Standard_Standard
5398 -- The scope does not contain an operator for the type
5403 -- If we have infix notation, the operator must be usable.
5404 -- Within an instance, if the type is already established we
5405 -- know it is correct.
5406 -- In Ada 2005, the equality on anonymous access types is declared
5407 -- in Standard, and is always visible.
5409 elsif In_Open_Scopes (Scope (Bas))
5410 or else Is_Potentially_Use_Visible (Bas)
5411 or else In_Use (Bas)
5412 or else (In_Use (Scope (Bas))
5413 and then not Is_Hidden (Bas))
5414 or else (In_Instance
5415 and then First_Subtype (T1) = First_Subtype (Etype (R)))
5416 or else Ekind (T1) = E_Anonymous_Access_Type
5421 -- Save candidate type for subsequent error message, if any
5423 if not Is_Limited_Type (T1) then
5424 Candidate_Type := T1;
5430 -- Ada 2005 (AI-230): Keep restriction imposed by Ada 83 and 95:
5431 -- Do not allow anonymous access types in equality operators.
5433 if Ada_Version < Ada_2005
5434 and then Ekind (T1) = E_Anonymous_Access_Type
5439 if T1 /= Standard_Void_Type
5440 and then not Is_Limited_Type (T1)
5441 and then not Is_Limited_Composite (T1)
5442 and then Has_Compatible_Type (R, T1)
5445 and then Base_Type (T1) /= Base_Type (T_F)
5447 It := Disambiguate (L, I_F, Index, Any_Type);
5449 if It = No_Interp then
5450 Ambiguous_Operands (N);
5451 Set_Etype (L, Any_Type);
5464 if not Analyzed (L) then
5468 Find_Non_Universal_Interpretations (N, R, Op_Id, T1);
5470 -- Case of operator was not visible, Etype still set to Any_Type
5472 if Etype (N) = Any_Type then
5476 elsif Scop = Standard_Standard
5477 and then Ekind (T1) = E_Anonymous_Access_Type
5483 -- Start of processing for Find_Equality_Types
5486 -- If left operand is aggregate, the right operand has to
5487 -- provide a usable type for it.
5489 if Nkind (L) = N_Aggregate
5490 and then Nkind (R) /= N_Aggregate
5492 Find_Equality_Types (L => R, R => L, Op_Id => Op_Id, N => N);
5496 if Nkind (N) = N_Function_Call
5497 and then Nkind (Name (N)) = N_Expanded_Name
5499 Scop := Entity (Prefix (Name (N)));
5501 -- The prefix may be a package renaming, and the subsequent test
5502 -- requires the original package.
5504 if Ekind (Scop) = E_Package
5505 and then Present (Renamed_Entity (Scop))
5507 Scop := Renamed_Entity (Scop);
5508 Set_Entity (Prefix (Name (N)), Scop);
5512 if not Is_Overloaded (L) then
5513 Try_One_Interp (Etype (L));
5516 Get_First_Interp (L, Index, It);
5517 while Present (It.Typ) loop
5518 Try_One_Interp (It.Typ);
5519 Get_Next_Interp (Index, It);
5522 end Find_Equality_Types;
5524 -------------------------
5525 -- Find_Negation_Types --
5526 -------------------------
5528 procedure Find_Negation_Types
5533 Index : Interp_Index;
5537 if not Is_Overloaded (R) then
5538 if Etype (R) = Universal_Integer then
5539 Add_One_Interp (N, Op_Id, Any_Modular);
5540 elsif Valid_Boolean_Arg (Etype (R)) then
5541 Add_One_Interp (N, Op_Id, Etype (R));
5545 Get_First_Interp (R, Index, It);
5546 while Present (It.Typ) loop
5547 if Valid_Boolean_Arg (It.Typ) then
5548 Add_One_Interp (N, Op_Id, It.Typ);
5551 Get_Next_Interp (Index, It);
5554 end Find_Negation_Types;
5556 ------------------------------
5557 -- Find_Primitive_Operation --
5558 ------------------------------
5560 function Find_Primitive_Operation (N : Node_Id) return Boolean is
5561 Obj : constant Node_Id := Prefix (N);
5562 Op : constant Node_Id := Selector_Name (N);
5569 Set_Etype (Op, Any_Type);
5571 if Is_Access_Type (Etype (Obj)) then
5572 Typ := Designated_Type (Etype (Obj));
5577 if Is_Class_Wide_Type (Typ) then
5578 Typ := Root_Type (Typ);
5581 Prims := Primitive_Operations (Typ);
5583 Prim := First_Elmt (Prims);
5584 while Present (Prim) loop
5585 if Chars (Node (Prim)) = Chars (Op) then
5586 Add_One_Interp (Op, Node (Prim), Etype (Node (Prim)));
5587 Set_Etype (N, Etype (Node (Prim)));
5593 -- Now look for class-wide operations of the type or any of its
5594 -- ancestors by iterating over the homonyms of the selector.
5597 Cls_Type : constant Entity_Id := Class_Wide_Type (Typ);
5601 Hom := Current_Entity (Op);
5602 while Present (Hom) loop
5603 if (Ekind (Hom) = E_Procedure
5605 Ekind (Hom) = E_Function)
5606 and then Scope (Hom) = Scope (Typ)
5607 and then Present (First_Formal (Hom))
5609 (Base_Type (Etype (First_Formal (Hom))) = Cls_Type
5611 (Is_Access_Type (Etype (First_Formal (Hom)))
5613 Ekind (Etype (First_Formal (Hom))) =
5614 E_Anonymous_Access_Type
5617 (Designated_Type (Etype (First_Formal (Hom)))) =
5620 Add_One_Interp (Op, Hom, Etype (Hom));
5621 Set_Etype (N, Etype (Hom));
5624 Hom := Homonym (Hom);
5628 return Etype (Op) /= Any_Type;
5629 end Find_Primitive_Operation;
5631 ----------------------
5632 -- Find_Unary_Types --
5633 ----------------------
5635 procedure Find_Unary_Types
5640 Index : Interp_Index;
5644 if not Is_Overloaded (R) then
5645 if Is_Numeric_Type (Etype (R)) then
5646 Add_One_Interp (N, Op_Id, Base_Type (Etype (R)));
5650 Get_First_Interp (R, Index, It);
5651 while Present (It.Typ) loop
5652 if Is_Numeric_Type (It.Typ) then
5653 Add_One_Interp (N, Op_Id, Base_Type (It.Typ));
5656 Get_Next_Interp (Index, It);
5659 end Find_Unary_Types;
5665 function Junk_Operand (N : Node_Id) return Boolean is
5669 if Error_Posted (N) then
5673 -- Get entity to be tested
5675 if Is_Entity_Name (N)
5676 and then Present (Entity (N))
5680 -- An odd case, a procedure name gets converted to a very peculiar
5681 -- function call, and here is where we detect this happening.
5683 elsif Nkind (N) = N_Function_Call
5684 and then Is_Entity_Name (Name (N))
5685 and then Present (Entity (Name (N)))
5689 -- Another odd case, there are at least some cases of selected
5690 -- components where the selected component is not marked as having
5691 -- an entity, even though the selector does have an entity
5693 elsif Nkind (N) = N_Selected_Component
5694 and then Present (Entity (Selector_Name (N)))
5696 Enode := Selector_Name (N);
5702 -- Now test the entity we got to see if it is a bad case
5704 case Ekind (Entity (Enode)) is
5708 ("package name cannot be used as operand", Enode);
5710 when Generic_Unit_Kind =>
5712 ("generic unit name cannot be used as operand", Enode);
5716 ("subtype name cannot be used as operand", Enode);
5720 ("entry name cannot be used as operand", Enode);
5724 ("procedure name cannot be used as operand", Enode);
5728 ("exception name cannot be used as operand", Enode);
5730 when E_Block | E_Label | E_Loop =>
5732 ("label name cannot be used as operand", Enode);
5742 --------------------
5743 -- Operator_Check --
5744 --------------------
5746 procedure Operator_Check (N : Node_Id) is
5748 Remove_Abstract_Operations (N);
5750 -- Test for case of no interpretation found for operator
5752 if Etype (N) = Any_Type then
5756 Op_Id : Entity_Id := Empty;
5759 R := Right_Opnd (N);
5761 if Nkind (N) in N_Binary_Op then
5767 -- If either operand has no type, then don't complain further,
5768 -- since this simply means that we have a propagated error.
5771 or else Etype (R) = Any_Type
5772 or else (Nkind (N) in N_Binary_Op and then Etype (L) = Any_Type)
5776 -- We explicitly check for the case of concatenation of component
5777 -- with component to avoid reporting spurious matching array types
5778 -- that might happen to be lurking in distant packages (such as
5779 -- run-time packages). This also prevents inconsistencies in the
5780 -- messages for certain ACVC B tests, which can vary depending on
5781 -- types declared in run-time interfaces. Another improvement when
5782 -- aggregates are present is to look for a well-typed operand.
5784 elsif Present (Candidate_Type)
5785 and then (Nkind (N) /= N_Op_Concat
5786 or else Is_Array_Type (Etype (L))
5787 or else Is_Array_Type (Etype (R)))
5789 if Nkind (N) = N_Op_Concat then
5790 if Etype (L) /= Any_Composite
5791 and then Is_Array_Type (Etype (L))
5793 Candidate_Type := Etype (L);
5795 elsif Etype (R) /= Any_Composite
5796 and then Is_Array_Type (Etype (R))
5798 Candidate_Type := Etype (R);
5802 Error_Msg_NE -- CODEFIX
5803 ("operator for} is not directly visible!",
5804 N, First_Subtype (Candidate_Type));
5807 U : constant Node_Id :=
5808 Cunit (Get_Source_Unit (Candidate_Type));
5810 if Unit_Is_Visible (U) then
5811 Error_Msg_N -- CODEFIX
5812 ("use clause would make operation legal!", N);
5814 Error_Msg_NE -- CODEFIX
5815 ("add with_clause and use_clause for&!",
5816 N, Defining_Entity (Unit (U)));
5821 -- If either operand is a junk operand (e.g. package name), then
5822 -- post appropriate error messages, but do not complain further.
5824 -- Note that the use of OR in this test instead of OR ELSE is
5825 -- quite deliberate, we may as well check both operands in the
5826 -- binary operator case.
5828 elsif Junk_Operand (R)
5829 or (Nkind (N) in N_Binary_Op and then Junk_Operand (L))
5833 -- If we have a logical operator, one of whose operands is
5834 -- Boolean, then we know that the other operand cannot resolve to
5835 -- Boolean (since we got no interpretations), but in that case we
5836 -- pretty much know that the other operand should be Boolean, so
5837 -- resolve it that way (generating an error)
5839 elsif Nkind_In (N, N_Op_And, N_Op_Or, N_Op_Xor) then
5840 if Etype (L) = Standard_Boolean then
5841 Resolve (R, Standard_Boolean);
5843 elsif Etype (R) = Standard_Boolean then
5844 Resolve (L, Standard_Boolean);
5848 -- For an arithmetic operator or comparison operator, if one
5849 -- of the operands is numeric, then we know the other operand
5850 -- is not the same numeric type. If it is a non-numeric type,
5851 -- then probably it is intended to match the other operand.
5853 elsif Nkind_In (N, N_Op_Add,
5859 Nkind_In (N, N_Op_Lt,
5865 if Is_Numeric_Type (Etype (L))
5866 and then not Is_Numeric_Type (Etype (R))
5868 Resolve (R, Etype (L));
5871 elsif Is_Numeric_Type (Etype (R))
5872 and then not Is_Numeric_Type (Etype (L))
5874 Resolve (L, Etype (R));
5878 -- Comparisons on A'Access are common enough to deserve a
5881 elsif Nkind_In (N, N_Op_Eq, N_Op_Ne)
5882 and then Ekind (Etype (L)) = E_Access_Attribute_Type
5883 and then Ekind (Etype (R)) = E_Access_Attribute_Type
5886 ("two access attributes cannot be compared directly", N);
5888 ("\use qualified expression for one of the operands",
5892 -- Another one for C programmers
5894 elsif Nkind (N) = N_Op_Concat
5895 and then Valid_Boolean_Arg (Etype (L))
5896 and then Valid_Boolean_Arg (Etype (R))
5898 Error_Msg_N ("invalid operands for concatenation", N);
5899 Error_Msg_N -- CODEFIX
5900 ("\maybe AND was meant", N);
5903 -- A special case for comparison of access parameter with null
5905 elsif Nkind (N) = N_Op_Eq
5906 and then Is_Entity_Name (L)
5907 and then Nkind (Parent (Entity (L))) = N_Parameter_Specification
5908 and then Nkind (Parameter_Type (Parent (Entity (L)))) =
5910 and then Nkind (R) = N_Null
5912 Error_Msg_N ("access parameter is not allowed to be null", L);
5913 Error_Msg_N ("\(call would raise Constraint_Error)", L);
5916 -- Another special case for exponentiation, where the right
5917 -- operand must be Natural, independently of the base.
5919 elsif Nkind (N) = N_Op_Expon
5920 and then Is_Numeric_Type (Etype (L))
5921 and then not Is_Overloaded (R)
5923 First_Subtype (Base_Type (Etype (R))) /= Standard_Integer
5924 and then Base_Type (Etype (R)) /= Universal_Integer
5927 ("exponent must be of type Natural, found}", R, Etype (R));
5931 -- If we fall through then just give general message. Note that in
5932 -- the following messages, if the operand is overloaded we choose
5933 -- an arbitrary type to complain about, but that is probably more
5934 -- useful than not giving a type at all.
5936 if Nkind (N) in N_Unary_Op then
5937 Error_Msg_Node_2 := Etype (R);
5938 Error_Msg_N ("operator& not defined for}", N);
5942 if Nkind (N) in N_Binary_Op then
5943 if not Is_Overloaded (L)
5944 and then not Is_Overloaded (R)
5945 and then Base_Type (Etype (L)) = Base_Type (Etype (R))
5947 Error_Msg_Node_2 := First_Subtype (Etype (R));
5948 Error_Msg_N ("there is no applicable operator& for}", N);
5951 -- Another attempt to find a fix: one of the candidate
5952 -- interpretations may not be use-visible. This has
5953 -- already been checked for predefined operators, so
5954 -- we examine only user-defined functions.
5956 Op_Id := Get_Name_Entity_Id (Chars (N));
5958 while Present (Op_Id) loop
5959 if Ekind (Op_Id) /= E_Operator
5960 and then Is_Overloadable (Op_Id)
5962 if not Is_Immediately_Visible (Op_Id)
5963 and then not In_Use (Scope (Op_Id))
5964 and then not Is_Abstract_Subprogram (Op_Id)
5965 and then not Is_Hidden (Op_Id)
5966 and then Ekind (Scope (Op_Id)) = E_Package
5969 (L, Etype (First_Formal (Op_Id)))
5971 (Next_Formal (First_Formal (Op_Id)))
5975 Etype (Next_Formal (First_Formal (Op_Id))))
5978 ("No legal interpretation for operator&", N);
5980 ("\use clause on& would make operation legal",
5986 Op_Id := Homonym (Op_Id);
5990 Error_Msg_N ("invalid operand types for operator&", N);
5992 if Nkind (N) /= N_Op_Concat then
5993 Error_Msg_NE ("\left operand has}!", N, Etype (L));
5994 Error_Msg_NE ("\right operand has}!", N, Etype (R));
6004 -----------------------------------------
6005 -- Process_Implicit_Dereference_Prefix --
6006 -----------------------------------------
6008 function Process_Implicit_Dereference_Prefix
6010 P : Entity_Id) return Entity_Id
6013 Typ : constant Entity_Id := Designated_Type (Etype (P));
6017 and then (Operating_Mode = Check_Semantics or else not Expander_Active)
6019 -- We create a dummy reference to E to ensure that the reference
6020 -- is not considered as part of an assignment (an implicit
6021 -- dereference can never assign to its prefix). The Comes_From_Source
6022 -- attribute needs to be propagated for accurate warnings.
6024 Ref := New_Reference_To (E, Sloc (P));
6025 Set_Comes_From_Source (Ref, Comes_From_Source (P));
6026 Generate_Reference (E, Ref);
6029 -- An implicit dereference is a legal occurrence of an
6030 -- incomplete type imported through a limited_with clause,
6031 -- if the full view is visible.
6033 if From_With_Type (Typ)
6034 and then not From_With_Type (Scope (Typ))
6036 (Is_Immediately_Visible (Scope (Typ))
6038 (Is_Child_Unit (Scope (Typ))
6039 and then Is_Visible_Child_Unit (Scope (Typ))))
6041 return Available_View (Typ);
6046 end Process_Implicit_Dereference_Prefix;
6048 --------------------------------
6049 -- Remove_Abstract_Operations --
6050 --------------------------------
6052 procedure Remove_Abstract_Operations (N : Node_Id) is
6053 Abstract_Op : Entity_Id := Empty;
6054 Address_Kludge : Boolean := False;
6058 -- AI-310: If overloaded, remove abstract non-dispatching operations. We
6059 -- activate this if either extensions are enabled, or if the abstract
6060 -- operation in question comes from a predefined file. This latter test
6061 -- allows us to use abstract to make operations invisible to users. In
6062 -- particular, if type Address is non-private and abstract subprograms
6063 -- are used to hide its operators, they will be truly hidden.
6065 type Operand_Position is (First_Op, Second_Op);
6066 Univ_Type : constant Entity_Id := Universal_Interpretation (N);
6068 procedure Remove_Address_Interpretations (Op : Operand_Position);
6069 -- Ambiguities may arise when the operands are literal and the address
6070 -- operations in s-auxdec are visible. In that case, remove the
6071 -- interpretation of a literal as Address, to retain the semantics of
6072 -- Address as a private type.
6074 ------------------------------------
6075 -- Remove_Address_Interpretations --
6076 ------------------------------------
6078 procedure Remove_Address_Interpretations (Op : Operand_Position) is
6082 if Is_Overloaded (N) then
6083 Get_First_Interp (N, I, It);
6084 while Present (It.Nam) loop
6085 Formal := First_Entity (It.Nam);
6087 if Op = Second_Op then
6088 Formal := Next_Entity (Formal);
6091 if Is_Descendent_Of_Address (Etype (Formal)) then
6092 Address_Kludge := True;
6096 Get_Next_Interp (I, It);
6099 end Remove_Address_Interpretations;
6101 -- Start of processing for Remove_Abstract_Operations
6104 if Is_Overloaded (N) then
6105 Get_First_Interp (N, I, It);
6107 while Present (It.Nam) loop
6108 if Is_Overloadable (It.Nam)
6109 and then Is_Abstract_Subprogram (It.Nam)
6110 and then not Is_Dispatching_Operation (It.Nam)
6112 Abstract_Op := It.Nam;
6114 if Is_Descendent_Of_Address (It.Typ) then
6115 Address_Kludge := True;
6119 -- In Ada 2005, this operation does not participate in Overload
6120 -- resolution. If the operation is defined in a predefined
6121 -- unit, it is one of the operations declared abstract in some
6122 -- variants of System, and it must be removed as well.
6124 elsif Ada_Version >= Ada_2005
6125 or else Is_Predefined_File_Name
6126 (Unit_File_Name (Get_Source_Unit (It.Nam)))
6133 Get_Next_Interp (I, It);
6136 if No (Abstract_Op) then
6138 -- If some interpretation yields an integer type, it is still
6139 -- possible that there are address interpretations. Remove them
6140 -- if one operand is a literal, to avoid spurious ambiguities
6141 -- on systems where Address is a visible integer type.
6143 if Is_Overloaded (N)
6144 and then Nkind (N) in N_Op
6145 and then Is_Integer_Type (Etype (N))
6147 if Nkind (N) in N_Binary_Op then
6148 if Nkind (Right_Opnd (N)) = N_Integer_Literal then
6149 Remove_Address_Interpretations (Second_Op);
6151 elsif Nkind (Right_Opnd (N)) = N_Integer_Literal then
6152 Remove_Address_Interpretations (First_Op);
6157 elsif Nkind (N) in N_Op then
6159 -- Remove interpretations that treat literals as addresses. This
6160 -- is never appropriate, even when Address is defined as a visible
6161 -- Integer type. The reason is that we would really prefer Address
6162 -- to behave as a private type, even in this case, which is there
6163 -- only to accommodate oddities of VMS address sizes. If Address
6164 -- is a visible integer type, we get lots of overload ambiguities.
6166 if Nkind (N) in N_Binary_Op then
6168 U1 : constant Boolean :=
6169 Present (Universal_Interpretation (Right_Opnd (N)));
6170 U2 : constant Boolean :=
6171 Present (Universal_Interpretation (Left_Opnd (N)));
6175 Remove_Address_Interpretations (Second_Op);
6179 Remove_Address_Interpretations (First_Op);
6182 if not (U1 and U2) then
6184 -- Remove corresponding predefined operator, which is
6185 -- always added to the overload set.
6187 Get_First_Interp (N, I, It);
6188 while Present (It.Nam) loop
6189 if Scope (It.Nam) = Standard_Standard
6190 and then Base_Type (It.Typ) =
6191 Base_Type (Etype (Abstract_Op))
6196 Get_Next_Interp (I, It);
6199 elsif Is_Overloaded (N)
6200 and then Present (Univ_Type)
6202 -- If both operands have a universal interpretation,
6203 -- it is still necessary to remove interpretations that
6204 -- yield Address. Any remaining ambiguities will be
6205 -- removed in Disambiguate.
6207 Get_First_Interp (N, I, It);
6208 while Present (It.Nam) loop
6209 if Is_Descendent_Of_Address (It.Typ) then
6212 elsif not Is_Type (It.Nam) then
6213 Set_Entity (N, It.Nam);
6216 Get_Next_Interp (I, It);
6222 elsif Nkind (N) = N_Function_Call
6224 (Nkind (Name (N)) = N_Operator_Symbol
6226 (Nkind (Name (N)) = N_Expanded_Name
6228 Nkind (Selector_Name (Name (N))) = N_Operator_Symbol))
6232 Arg1 : constant Node_Id := First (Parameter_Associations (N));
6233 U1 : constant Boolean :=
6234 Present (Universal_Interpretation (Arg1));
6235 U2 : constant Boolean :=
6236 Present (Next (Arg1)) and then
6237 Present (Universal_Interpretation (Next (Arg1)));
6241 Remove_Address_Interpretations (First_Op);
6245 Remove_Address_Interpretations (Second_Op);
6248 if not (U1 and U2) then
6249 Get_First_Interp (N, I, It);
6250 while Present (It.Nam) loop
6251 if Scope (It.Nam) = Standard_Standard
6252 and then It.Typ = Base_Type (Etype (Abstract_Op))
6257 Get_Next_Interp (I, It);
6263 -- If the removal has left no valid interpretations, emit an error
6264 -- message now and label node as illegal.
6266 if Present (Abstract_Op) then
6267 Get_First_Interp (N, I, It);
6271 -- Removal of abstract operation left no viable candidate
6273 Set_Etype (N, Any_Type);
6274 Error_Msg_Sloc := Sloc (Abstract_Op);
6276 ("cannot call abstract operation& declared#", N, Abstract_Op);
6278 -- In Ada 2005, an abstract operation may disable predefined
6279 -- operators. Since the context is not yet known, we mark the
6280 -- predefined operators as potentially hidden. Do not include
6281 -- predefined operators when addresses are involved since this
6282 -- case is handled separately.
6284 elsif Ada_Version >= Ada_2005
6285 and then not Address_Kludge
6287 while Present (It.Nam) loop
6288 if Is_Numeric_Type (It.Typ)
6289 and then Scope (It.Typ) = Standard_Standard
6291 Set_Abstract_Op (I, Abstract_Op);
6294 Get_Next_Interp (I, It);
6299 end Remove_Abstract_Operations;
6301 -----------------------
6302 -- Try_Indirect_Call --
6303 -----------------------
6305 function Try_Indirect_Call
6308 Typ : Entity_Id) return Boolean
6314 pragma Warnings (Off, Call_OK);
6317 Normalize_Actuals (N, Designated_Type (Typ), False, Call_OK);
6319 Actual := First_Actual (N);
6320 Formal := First_Formal (Designated_Type (Typ));
6321 while Present (Actual) and then Present (Formal) loop
6322 if not Has_Compatible_Type (Actual, Etype (Formal)) then
6327 Next_Formal (Formal);
6330 if No (Actual) and then No (Formal) then
6331 Add_One_Interp (N, Nam, Etype (Designated_Type (Typ)));
6333 -- Nam is a candidate interpretation for the name in the call,
6334 -- if it is not an indirect call.
6336 if not Is_Type (Nam)
6337 and then Is_Entity_Name (Name (N))
6339 Set_Entity (Name (N), Nam);
6346 end Try_Indirect_Call;
6348 ----------------------
6349 -- Try_Indexed_Call --
6350 ----------------------
6352 function Try_Indexed_Call
6356 Skip_First : Boolean) return Boolean
6358 Loc : constant Source_Ptr := Sloc (N);
6359 Actuals : constant List_Id := Parameter_Associations (N);
6364 Actual := First (Actuals);
6366 -- If the call was originally written in prefix form, skip the first
6367 -- actual, which is obviously not defaulted.
6373 Index := First_Index (Typ);
6374 while Present (Actual) and then Present (Index) loop
6376 -- If the parameter list has a named association, the expression
6377 -- is definitely a call and not an indexed component.
6379 if Nkind (Actual) = N_Parameter_Association then
6383 if Is_Entity_Name (Actual)
6384 and then Is_Type (Entity (Actual))
6385 and then No (Next (Actual))
6387 -- A single actual that is a type name indicates a slice if the
6388 -- type is discrete, and an error otherwise.
6390 if Is_Discrete_Type (Entity (Actual)) then
6394 Make_Function_Call (Loc,
6395 Name => Relocate_Node (Name (N))),
6397 New_Occurrence_Of (Entity (Actual), Sloc (Actual))));
6402 Error_Msg_N ("invalid use of type in expression", Actual);
6403 Set_Etype (N, Any_Type);
6408 elsif not Has_Compatible_Type (Actual, Etype (Index)) then
6416 if No (Actual) and then No (Index) then
6417 Add_One_Interp (N, Nam, Component_Type (Typ));
6419 -- Nam is a candidate interpretation for the name in the call,
6420 -- if it is not an indirect call.
6422 if not Is_Type (Nam)
6423 and then Is_Entity_Name (Name (N))
6425 Set_Entity (Name (N), Nam);
6432 end Try_Indexed_Call;
6434 --------------------------
6435 -- Try_Object_Operation --
6436 --------------------------
6438 function Try_Object_Operation (N : Node_Id) return Boolean is
6439 K : constant Node_Kind := Nkind (Parent (N));
6440 Is_Subprg_Call : constant Boolean := Nkind_In
6441 (K, N_Procedure_Call_Statement,
6443 Loc : constant Source_Ptr := Sloc (N);
6444 Obj : constant Node_Id := Prefix (N);
6446 Subprog : constant Node_Id :=
6447 Make_Identifier (Sloc (Selector_Name (N)),
6448 Chars => Chars (Selector_Name (N)));
6449 -- Identifier on which possible interpretations will be collected
6451 Report_Error : Boolean := False;
6452 -- If no candidate interpretation matches the context, redo the
6453 -- analysis with error enabled to provide additional information.
6456 Candidate : Entity_Id := Empty;
6457 New_Call_Node : Node_Id := Empty;
6458 Node_To_Replace : Node_Id;
6459 Obj_Type : Entity_Id := Etype (Obj);
6460 Success : Boolean := False;
6462 function Valid_Candidate
6465 Subp : Entity_Id) return Entity_Id;
6466 -- If the subprogram is a valid interpretation, record it, and add
6467 -- to the list of interpretations of Subprog.
6469 procedure Complete_Object_Operation
6470 (Call_Node : Node_Id;
6471 Node_To_Replace : Node_Id);
6472 -- Make Subprog the name of Call_Node, replace Node_To_Replace with
6473 -- Call_Node, insert the object (or its dereference) as the first actual
6474 -- in the call, and complete the analysis of the call.
6476 procedure Report_Ambiguity (Op : Entity_Id);
6477 -- If a prefixed procedure call is ambiguous, indicate whether the
6478 -- call includes an implicit dereference or an implicit 'Access.
6480 procedure Transform_Object_Operation
6481 (Call_Node : out Node_Id;
6482 Node_To_Replace : out Node_Id);
6483 -- Transform Obj.Operation (X, Y,,) into Operation (Obj, X, Y ..)
6484 -- Call_Node is the resulting subprogram call, Node_To_Replace is
6485 -- either N or the parent of N, and Subprog is a reference to the
6486 -- subprogram we are trying to match.
6488 function Try_Class_Wide_Operation
6489 (Call_Node : Node_Id;
6490 Node_To_Replace : Node_Id) return Boolean;
6491 -- Traverse all ancestor types looking for a class-wide subprogram
6492 -- for which the current operation is a valid non-dispatching call.
6494 procedure Try_One_Prefix_Interpretation (T : Entity_Id);
6495 -- If prefix is overloaded, its interpretation may include different
6496 -- tagged types, and we must examine the primitive operations and
6497 -- the class-wide operations of each in order to find candidate
6498 -- interpretations for the call as a whole.
6500 function Try_Primitive_Operation
6501 (Call_Node : Node_Id;
6502 Node_To_Replace : Node_Id) return Boolean;
6503 -- Traverse the list of primitive subprograms looking for a dispatching
6504 -- operation for which the current node is a valid call .
6506 ---------------------
6507 -- Valid_Candidate --
6508 ---------------------
6510 function Valid_Candidate
6513 Subp : Entity_Id) return Entity_Id
6515 Arr_Type : Entity_Id;
6516 Comp_Type : Entity_Id;
6519 -- If the subprogram is a valid interpretation, record it in global
6520 -- variable Subprog, to collect all possible overloadings.
6523 if Subp /= Entity (Subprog) then
6524 Add_One_Interp (Subprog, Subp, Etype (Subp));
6528 -- If the call may be an indexed call, retrieve component type of
6529 -- resulting expression, and add possible interpretation.
6534 if Nkind (Call) = N_Function_Call
6535 and then Nkind (Parent (N)) = N_Indexed_Component
6536 and then Needs_One_Actual (Subp)
6538 if Is_Array_Type (Etype (Subp)) then
6539 Arr_Type := Etype (Subp);
6541 elsif Is_Access_Type (Etype (Subp))
6542 and then Is_Array_Type (Designated_Type (Etype (Subp)))
6544 Arr_Type := Designated_Type (Etype (Subp));
6548 if Present (Arr_Type) then
6550 -- Verify that the actuals (excluding the object) match the types
6558 Actual := Next (First_Actual (Call));
6559 Index := First_Index (Arr_Type);
6560 while Present (Actual) and then Present (Index) loop
6561 if not Has_Compatible_Type (Actual, Etype (Index)) then
6566 Next_Actual (Actual);
6572 and then Present (Arr_Type)
6574 Comp_Type := Component_Type (Arr_Type);
6578 if Present (Comp_Type)
6579 and then Etype (Subprog) /= Comp_Type
6581 Add_One_Interp (Subprog, Subp, Comp_Type);
6585 if Etype (Call) /= Any_Type then
6590 end Valid_Candidate;
6592 -------------------------------
6593 -- Complete_Object_Operation --
6594 -------------------------------
6596 procedure Complete_Object_Operation
6597 (Call_Node : Node_Id;
6598 Node_To_Replace : Node_Id)
6600 Control : constant Entity_Id := First_Formal (Entity (Subprog));
6601 Formal_Type : constant Entity_Id := Etype (Control);
6602 First_Actual : Node_Id;
6605 -- Place the name of the operation, with its interpretations,
6606 -- on the rewritten call.
6608 Set_Name (Call_Node, Subprog);
6610 First_Actual := First (Parameter_Associations (Call_Node));
6612 -- For cross-reference purposes, treat the new node as being in
6613 -- the source if the original one is.
6615 Set_Comes_From_Source (Subprog, Comes_From_Source (N));
6616 Set_Comes_From_Source (Call_Node, Comes_From_Source (N));
6618 if Nkind (N) = N_Selected_Component
6619 and then not Inside_A_Generic
6621 Set_Entity (Selector_Name (N), Entity (Subprog));
6624 -- If need be, rewrite first actual as an explicit dereference
6625 -- If the call is overloaded, the rewriting can only be done
6626 -- once the primitive operation is identified.
6628 if Is_Overloaded (Subprog) then
6630 -- The prefix itself may be overloaded, and its interpretations
6631 -- must be propagated to the new actual in the call.
6633 if Is_Overloaded (Obj) then
6634 Save_Interps (Obj, First_Actual);
6637 Rewrite (First_Actual, Obj);
6639 elsif not Is_Access_Type (Formal_Type)
6640 and then Is_Access_Type (Etype (Obj))
6642 Rewrite (First_Actual,
6643 Make_Explicit_Dereference (Sloc (Obj), Obj));
6644 Analyze (First_Actual);
6646 -- If we need to introduce an explicit dereference, verify that
6647 -- the resulting actual is compatible with the mode of the formal.
6649 if Ekind (First_Formal (Entity (Subprog))) /= E_In_Parameter
6650 and then Is_Access_Constant (Etype (Obj))
6653 ("expect variable in call to&", Prefix (N), Entity (Subprog));
6656 -- Conversely, if the formal is an access parameter and the object
6657 -- is not, replace the actual with a 'Access reference. Its analysis
6658 -- will check that the object is aliased.
6660 elsif Is_Access_Type (Formal_Type)
6661 and then not Is_Access_Type (Etype (Obj))
6663 -- A special case: A.all'access is illegal if A is an access to a
6664 -- constant and the context requires an access to a variable.
6666 if not Is_Access_Constant (Formal_Type) then
6667 if (Nkind (Obj) = N_Explicit_Dereference
6668 and then Is_Access_Constant (Etype (Prefix (Obj))))
6669 or else not Is_Variable (Obj)
6672 ("actual for& must be a variable", Obj, Control);
6676 Rewrite (First_Actual,
6677 Make_Attribute_Reference (Loc,
6678 Attribute_Name => Name_Access,
6679 Prefix => Relocate_Node (Obj)));
6681 if not Is_Aliased_View (Obj) then
6683 ("object in prefixed call to& must be aliased"
6684 & " (RM-2005 4.3.1 (13))",
6685 Prefix (First_Actual), Subprog);
6688 Analyze (First_Actual);
6691 if Is_Overloaded (Obj) then
6692 Save_Interps (Obj, First_Actual);
6695 Rewrite (First_Actual, Obj);
6698 Rewrite (Node_To_Replace, Call_Node);
6700 -- Propagate the interpretations collected in subprog to the new
6701 -- function call node, to be resolved from context.
6703 if Is_Overloaded (Subprog) then
6704 Save_Interps (Subprog, Node_To_Replace);
6707 Analyze (Node_To_Replace);
6709 -- If the operation has been rewritten into a call, which may get
6710 -- subsequently an explicit dereference, preserve the type on the
6711 -- original node (selected component or indexed component) for
6712 -- subsequent legality tests, e.g. Is_Variable. which examines
6713 -- the original node.
6715 if Nkind (Node_To_Replace) = N_Function_Call then
6717 (Original_Node (Node_To_Replace), Etype (Node_To_Replace));
6720 end Complete_Object_Operation;
6722 ----------------------
6723 -- Report_Ambiguity --
6724 ----------------------
6726 procedure Report_Ambiguity (Op : Entity_Id) is
6727 Access_Formal : constant Boolean :=
6728 Is_Access_Type (Etype (First_Formal (Op)));
6729 Access_Actual : constant Boolean :=
6730 Is_Access_Type (Etype (Prefix (N)));
6733 Error_Msg_Sloc := Sloc (Op);
6735 if Access_Formal and then not Access_Actual then
6736 if Nkind (Parent (Op)) = N_Full_Type_Declaration then
6738 ("\possible interpretation"
6739 & " (inherited, with implicit 'Access) #", N);
6742 ("\possible interpretation (with implicit 'Access) #", N);
6745 elsif not Access_Formal and then Access_Actual then
6746 if Nkind (Parent (Op)) = N_Full_Type_Declaration then
6748 ("\possible interpretation"
6749 & " ( inherited, with implicit dereference) #", N);
6752 ("\possible interpretation (with implicit dereference) #", N);
6756 if Nkind (Parent (Op)) = N_Full_Type_Declaration then
6757 Error_Msg_N ("\possible interpretation (inherited)#", N);
6759 Error_Msg_N -- CODEFIX
6760 ("\possible interpretation#", N);
6763 end Report_Ambiguity;
6765 --------------------------------
6766 -- Transform_Object_Operation --
6767 --------------------------------
6769 procedure Transform_Object_Operation
6770 (Call_Node : out Node_Id;
6771 Node_To_Replace : out Node_Id)
6773 Dummy : constant Node_Id := New_Copy (Obj);
6774 -- Placeholder used as a first parameter in the call, replaced
6775 -- eventually by the proper object.
6777 Parent_Node : constant Node_Id := Parent (N);
6783 -- Common case covering 1) Call to a procedure and 2) Call to a
6784 -- function that has some additional actuals.
6786 if Nkind_In (Parent_Node, N_Function_Call,
6787 N_Procedure_Call_Statement)
6789 -- N is a selected component node containing the name of the
6790 -- subprogram. If N is not the name of the parent node we must
6791 -- not replace the parent node by the new construct. This case
6792 -- occurs when N is a parameterless call to a subprogram that
6793 -- is an actual parameter of a call to another subprogram. For
6795 -- Some_Subprogram (..., Obj.Operation, ...)
6797 and then Name (Parent_Node) = N
6799 Node_To_Replace := Parent_Node;
6801 Actuals := Parameter_Associations (Parent_Node);
6803 if Present (Actuals) then
6804 Prepend (Dummy, Actuals);
6806 Actuals := New_List (Dummy);
6809 if Nkind (Parent_Node) = N_Procedure_Call_Statement then
6811 Make_Procedure_Call_Statement (Loc,
6812 Name => New_Copy (Subprog),
6813 Parameter_Associations => Actuals);
6817 Make_Function_Call (Loc,
6818 Name => New_Copy (Subprog),
6819 Parameter_Associations => Actuals);
6823 -- Before analysis, a function call appears as an indexed component
6824 -- if there are no named associations.
6826 elsif Nkind (Parent_Node) = N_Indexed_Component
6827 and then N = Prefix (Parent_Node)
6829 Node_To_Replace := Parent_Node;
6830 Actuals := Expressions (Parent_Node);
6832 Actual := First (Actuals);
6833 while Present (Actual) loop
6838 Prepend (Dummy, Actuals);
6841 Make_Function_Call (Loc,
6842 Name => New_Copy (Subprog),
6843 Parameter_Associations => Actuals);
6845 -- Parameterless call: Obj.F is rewritten as F (Obj)
6848 Node_To_Replace := N;
6851 Make_Function_Call (Loc,
6852 Name => New_Copy (Subprog),
6853 Parameter_Associations => New_List (Dummy));
6855 end Transform_Object_Operation;
6857 ------------------------------
6858 -- Try_Class_Wide_Operation --
6859 ------------------------------
6861 function Try_Class_Wide_Operation
6862 (Call_Node : Node_Id;
6863 Node_To_Replace : Node_Id) return Boolean
6865 Anc_Type : Entity_Id;
6866 Matching_Op : Entity_Id := Empty;
6869 procedure Traverse_Homonyms
6870 (Anc_Type : Entity_Id;
6871 Error : out Boolean);
6872 -- Traverse the homonym chain of the subprogram searching for those
6873 -- homonyms whose first formal has the Anc_Type's class-wide type,
6874 -- or an anonymous access type designating the class-wide type. If
6875 -- an ambiguity is detected, then Error is set to True.
6877 procedure Traverse_Interfaces
6878 (Anc_Type : Entity_Id;
6879 Error : out Boolean);
6880 -- Traverse the list of interfaces, if any, associated with Anc_Type
6881 -- and search for acceptable class-wide homonyms associated with each
6882 -- interface. If an ambiguity is detected, then Error is set to True.
6884 -----------------------
6885 -- Traverse_Homonyms --
6886 -----------------------
6888 procedure Traverse_Homonyms
6889 (Anc_Type : Entity_Id;
6890 Error : out Boolean)
6892 Cls_Type : Entity_Id;
6900 Cls_Type := Class_Wide_Type (Anc_Type);
6902 Hom := Current_Entity (Subprog);
6904 -- Find a non-hidden operation whose first parameter is of the
6905 -- class-wide type, a subtype thereof, or an anonymous access
6908 while Present (Hom) loop
6909 if Ekind_In (Hom, E_Procedure, E_Function)
6910 and then not Is_Hidden (Hom)
6911 and then Scope (Hom) = Scope (Anc_Type)
6912 and then Present (First_Formal (Hom))
6914 (Base_Type (Etype (First_Formal (Hom))) = Cls_Type
6916 (Is_Access_Type (Etype (First_Formal (Hom)))
6918 Ekind (Etype (First_Formal (Hom))) =
6919 E_Anonymous_Access_Type
6922 (Designated_Type (Etype (First_Formal (Hom)))) =
6925 Set_Etype (Call_Node, Any_Type);
6926 Set_Is_Overloaded (Call_Node, False);
6929 if No (Matching_Op) then
6930 Hom_Ref := New_Reference_To (Hom, Sloc (Subprog));
6931 Set_Etype (Call_Node, Any_Type);
6932 Set_Parent (Call_Node, Parent (Node_To_Replace));
6934 Set_Name (Call_Node, Hom_Ref);
6939 Report => Report_Error,
6941 Skip_First => True);
6944 Valid_Candidate (Success, Call_Node, Hom);
6950 Report => Report_Error,
6952 Skip_First => True);
6954 if Present (Valid_Candidate (Success, Call_Node, Hom))
6955 and then Nkind (Call_Node) /= N_Function_Call
6957 Error_Msg_NE ("ambiguous call to&", N, Hom);
6958 Report_Ambiguity (Matching_Op);
6959 Report_Ambiguity (Hom);
6966 Hom := Homonym (Hom);
6968 end Traverse_Homonyms;
6970 -------------------------
6971 -- Traverse_Interfaces --
6972 -------------------------
6974 procedure Traverse_Interfaces
6975 (Anc_Type : Entity_Id;
6976 Error : out Boolean)
6978 Intface_List : constant List_Id :=
6979 Abstract_Interface_List (Anc_Type);
6985 if Is_Non_Empty_List (Intface_List) then
6986 Intface := First (Intface_List);
6987 while Present (Intface) loop
6989 -- Look for acceptable class-wide homonyms associated with
6992 Traverse_Homonyms (Etype (Intface), Error);
6998 -- Continue the search by looking at each of the interface's
6999 -- associated interface ancestors.
7001 Traverse_Interfaces (Etype (Intface), Error);
7010 end Traverse_Interfaces;
7012 -- Start of processing for Try_Class_Wide_Operation
7015 -- Loop through ancestor types (including interfaces), traversing
7016 -- the homonym chain of the subprogram, trying out those homonyms
7017 -- whose first formal has the class-wide type of the ancestor, or
7018 -- an anonymous access type designating the class-wide type.
7020 Anc_Type := Obj_Type;
7022 -- Look for a match among homonyms associated with the ancestor
7024 Traverse_Homonyms (Anc_Type, Error);
7030 -- Continue the search for matches among homonyms associated with
7031 -- any interfaces implemented by the ancestor.
7033 Traverse_Interfaces (Anc_Type, Error);
7039 exit when Etype (Anc_Type) = Anc_Type;
7040 Anc_Type := Etype (Anc_Type);
7043 if Present (Matching_Op) then
7044 Set_Etype (Call_Node, Etype (Matching_Op));
7047 return Present (Matching_Op);
7048 end Try_Class_Wide_Operation;
7050 -----------------------------------
7051 -- Try_One_Prefix_Interpretation --
7052 -----------------------------------
7054 procedure Try_One_Prefix_Interpretation (T : Entity_Id) is
7058 if Is_Access_Type (Obj_Type) then
7059 Obj_Type := Designated_Type (Obj_Type);
7062 if Ekind (Obj_Type) = E_Private_Subtype then
7063 Obj_Type := Base_Type (Obj_Type);
7066 if Is_Class_Wide_Type (Obj_Type) then
7067 Obj_Type := Etype (Class_Wide_Type (Obj_Type));
7070 -- The type may have be obtained through a limited_with clause,
7071 -- in which case the primitive operations are available on its
7072 -- non-limited view. If still incomplete, retrieve full view.
7074 if Ekind (Obj_Type) = E_Incomplete_Type
7075 and then From_With_Type (Obj_Type)
7077 Obj_Type := Get_Full_View (Non_Limited_View (Obj_Type));
7080 -- If the object is not tagged, or the type is still an incomplete
7081 -- type, this is not a prefixed call.
7083 if not Is_Tagged_Type (Obj_Type)
7084 or else Is_Incomplete_Type (Obj_Type)
7089 if Try_Primitive_Operation
7090 (Call_Node => New_Call_Node,
7091 Node_To_Replace => Node_To_Replace)
7093 Try_Class_Wide_Operation
7094 (Call_Node => New_Call_Node,
7095 Node_To_Replace => Node_To_Replace)
7099 end Try_One_Prefix_Interpretation;
7101 -----------------------------
7102 -- Try_Primitive_Operation --
7103 -----------------------------
7105 function Try_Primitive_Operation
7106 (Call_Node : Node_Id;
7107 Node_To_Replace : Node_Id) return Boolean
7110 Prim_Op : Entity_Id;
7111 Matching_Op : Entity_Id := Empty;
7112 Prim_Op_Ref : Node_Id := Empty;
7114 Corr_Type : Entity_Id := Empty;
7115 -- If the prefix is a synchronized type, the controlling type of
7116 -- the primitive operation is the corresponding record type, else
7117 -- this is the object type itself.
7119 Success : Boolean := False;
7121 function Collect_Generic_Type_Ops (T : Entity_Id) return Elist_Id;
7122 -- For tagged types the candidate interpretations are found in
7123 -- the list of primitive operations of the type and its ancestors.
7124 -- For formal tagged types we have to find the operations declared
7125 -- in the same scope as the type (including in the generic formal
7126 -- part) because the type itself carries no primitive operations,
7127 -- except for formal derived types that inherit the operations of
7128 -- the parent and progenitors.
7129 -- If the context is a generic subprogram body, the generic formals
7130 -- are visible by name, but are not in the entity list of the
7131 -- subprogram because that list starts with the subprogram formals.
7132 -- We retrieve the candidate operations from the generic declaration.
7134 function Is_Private_Overriding (Op : Entity_Id) return Boolean;
7135 -- An operation that overrides an inherited operation in the private
7136 -- part of its package may be hidden, but if the inherited operation
7137 -- is visible a direct call to it will dispatch to the private one,
7138 -- which is therefore a valid candidate.
7140 function Valid_First_Argument_Of (Op : Entity_Id) return Boolean;
7141 -- Verify that the prefix, dereferenced if need be, is a valid
7142 -- controlling argument in a call to Op. The remaining actuals
7143 -- are checked in the subsequent call to Analyze_One_Call.
7145 ------------------------------
7146 -- Collect_Generic_Type_Ops --
7147 ------------------------------
7149 function Collect_Generic_Type_Ops (T : Entity_Id) return Elist_Id is
7150 Bas : constant Entity_Id := Base_Type (T);
7151 Candidates : constant Elist_Id := New_Elmt_List;
7155 procedure Check_Candidate;
7156 -- The operation is a candidate if its first parameter is a
7157 -- controlling operand of the desired type.
7159 -----------------------
7160 -- Check_Candidate; --
7161 -----------------------
7163 procedure Check_Candidate is
7165 Formal := First_Formal (Subp);
7168 and then Is_Controlling_Formal (Formal)
7170 (Base_Type (Etype (Formal)) = Bas
7172 (Is_Access_Type (Etype (Formal))
7173 and then Designated_Type (Etype (Formal)) = Bas))
7175 Append_Elmt (Subp, Candidates);
7177 end Check_Candidate;
7179 -- Start of processing for Collect_Generic_Type_Ops
7182 if Is_Derived_Type (T) then
7183 return Primitive_Operations (T);
7185 elsif Ekind_In (Scope (T), E_Procedure, E_Function) then
7187 -- Scan the list of generic formals to find subprograms
7188 -- that may have a first controlling formal of the type.
7190 if Nkind (Unit_Declaration_Node (Scope (T)))
7191 = N_Generic_Subprogram_Declaration
7198 First (Generic_Formal_Declarations
7199 (Unit_Declaration_Node (Scope (T))));
7200 while Present (Decl) loop
7201 if Nkind (Decl) in N_Formal_Subprogram_Declaration then
7202 Subp := Defining_Entity (Decl);
7213 -- Scan the list of entities declared in the same scope as
7214 -- the type. In general this will be an open scope, given that
7215 -- the call we are analyzing can only appear within a generic
7216 -- declaration or body (either the one that declares T, or a
7219 -- For a subtype representing a generic actual type, go to the
7222 if Is_Generic_Actual_Type (T) then
7223 Subp := First_Entity (Scope (Base_Type (T)));
7225 Subp := First_Entity (Scope (T));
7228 while Present (Subp) loop
7229 if Is_Overloadable (Subp) then
7238 end Collect_Generic_Type_Ops;
7240 ---------------------------
7241 -- Is_Private_Overriding --
7242 ---------------------------
7244 function Is_Private_Overriding (Op : Entity_Id) return Boolean is
7245 Visible_Op : constant Entity_Id := Homonym (Op);
7248 return Present (Visible_Op)
7249 and then Scope (Op) = Scope (Visible_Op)
7250 and then not Comes_From_Source (Visible_Op)
7251 and then Alias (Visible_Op) = Op
7252 and then not Is_Hidden (Visible_Op);
7253 end Is_Private_Overriding;
7255 -----------------------------
7256 -- Valid_First_Argument_Of --
7257 -----------------------------
7259 function Valid_First_Argument_Of (Op : Entity_Id) return Boolean is
7260 Typ : Entity_Id := Etype (First_Formal (Op));
7263 if Is_Concurrent_Type (Typ)
7264 and then Present (Corresponding_Record_Type (Typ))
7266 Typ := Corresponding_Record_Type (Typ);
7269 -- Simple case. Object may be a subtype of the tagged type or
7270 -- may be the corresponding record of a synchronized type.
7272 return Obj_Type = Typ
7273 or else Base_Type (Obj_Type) = Typ
7274 or else Corr_Type = Typ
7276 -- Prefix can be dereferenced
7279 (Is_Access_Type (Corr_Type)
7280 and then Designated_Type (Corr_Type) = Typ)
7282 -- Formal is an access parameter, for which the object
7283 -- can provide an access.
7286 (Ekind (Typ) = E_Anonymous_Access_Type
7288 Base_Type (Designated_Type (Typ)) = Base_Type (Corr_Type));
7289 end Valid_First_Argument_Of;
7291 -- Start of processing for Try_Primitive_Operation
7294 -- Look for subprograms in the list of primitive operations. The name
7295 -- must be identical, and the kind of call indicates the expected
7296 -- kind of operation (function or procedure). If the type is a
7297 -- (tagged) synchronized type, the primitive ops are attached to the
7298 -- corresponding record (base) type.
7300 if Is_Concurrent_Type (Obj_Type) then
7301 if Present (Corresponding_Record_Type (Obj_Type)) then
7302 Corr_Type := Base_Type (Corresponding_Record_Type (Obj_Type));
7303 Elmt := First_Elmt (Primitive_Operations (Corr_Type));
7305 Corr_Type := Obj_Type;
7306 Elmt := First_Elmt (Collect_Generic_Type_Ops (Obj_Type));
7309 elsif not Is_Generic_Type (Obj_Type) then
7310 Corr_Type := Obj_Type;
7311 Elmt := First_Elmt (Primitive_Operations (Obj_Type));
7314 Corr_Type := Obj_Type;
7315 Elmt := First_Elmt (Collect_Generic_Type_Ops (Obj_Type));
7318 while Present (Elmt) loop
7319 Prim_Op := Node (Elmt);
7321 if Chars (Prim_Op) = Chars (Subprog)
7322 and then Present (First_Formal (Prim_Op))
7323 and then Valid_First_Argument_Of (Prim_Op)
7325 (Nkind (Call_Node) = N_Function_Call)
7326 = (Ekind (Prim_Op) = E_Function)
7328 -- Ada 2005 (AI-251): If this primitive operation corresponds
7329 -- with an immediate ancestor interface there is no need to add
7330 -- it to the list of interpretations; the corresponding aliased
7331 -- primitive is also in this list of primitive operations and
7332 -- will be used instead.
7334 if (Present (Interface_Alias (Prim_Op))
7335 and then Is_Ancestor (Find_Dispatching_Type
7336 (Alias (Prim_Op)), Corr_Type))
7338 -- Do not consider hidden primitives unless the type is in an
7339 -- open scope or we are within an instance, where visibility
7340 -- is known to be correct, or else if this is an overriding
7341 -- operation in the private part for an inherited operation.
7343 or else (Is_Hidden (Prim_Op)
7344 and then not Is_Immediately_Visible (Obj_Type)
7345 and then not In_Instance
7346 and then not Is_Private_Overriding (Prim_Op))
7351 Set_Etype (Call_Node, Any_Type);
7352 Set_Is_Overloaded (Call_Node, False);
7354 if No (Matching_Op) then
7355 Prim_Op_Ref := New_Reference_To (Prim_Op, Sloc (Subprog));
7356 Candidate := Prim_Op;
7358 Set_Parent (Call_Node, Parent (Node_To_Replace));
7360 Set_Name (Call_Node, Prim_Op_Ref);
7366 Report => Report_Error,
7368 Skip_First => True);
7370 Matching_Op := Valid_Candidate (Success, Call_Node, Prim_Op);
7372 -- More than one interpretation, collect for subsequent
7373 -- disambiguation. If this is a procedure call and there
7374 -- is another match, report ambiguity now.
7380 Report => Report_Error,
7382 Skip_First => True);
7384 if Present (Valid_Candidate (Success, Call_Node, Prim_Op))
7385 and then Nkind (Call_Node) /= N_Function_Call
7387 Error_Msg_NE ("ambiguous call to&", N, Prim_Op);
7388 Report_Ambiguity (Matching_Op);
7389 Report_Ambiguity (Prim_Op);
7399 if Present (Matching_Op) then
7400 Set_Etype (Call_Node, Etype (Matching_Op));
7403 return Present (Matching_Op);
7404 end Try_Primitive_Operation;
7406 -- Start of processing for Try_Object_Operation
7409 Analyze_Expression (Obj);
7411 -- Analyze the actuals if node is known to be a subprogram call
7413 if Is_Subprg_Call and then N = Name (Parent (N)) then
7414 Actual := First (Parameter_Associations (Parent (N)));
7415 while Present (Actual) loop
7416 Analyze_Expression (Actual);
7421 -- Build a subprogram call node, using a copy of Obj as its first
7422 -- actual. This is a placeholder, to be replaced by an explicit
7423 -- dereference when needed.
7425 Transform_Object_Operation
7426 (Call_Node => New_Call_Node,
7427 Node_To_Replace => Node_To_Replace);
7429 Set_Etype (New_Call_Node, Any_Type);
7430 Set_Etype (Subprog, Any_Type);
7431 Set_Parent (New_Call_Node, Parent (Node_To_Replace));
7433 if not Is_Overloaded (Obj) then
7434 Try_One_Prefix_Interpretation (Obj_Type);
7441 Get_First_Interp (Obj, I, It);
7442 while Present (It.Nam) loop
7443 Try_One_Prefix_Interpretation (It.Typ);
7444 Get_Next_Interp (I, It);
7449 if Etype (New_Call_Node) /= Any_Type then
7450 Complete_Object_Operation
7451 (Call_Node => New_Call_Node,
7452 Node_To_Replace => Node_To_Replace);
7455 elsif Present (Candidate) then
7457 -- The argument list is not type correct. Re-analyze with error
7458 -- reporting enabled, and use one of the possible candidates.
7459 -- In All_Errors_Mode, re-analyze all failed interpretations.
7461 if All_Errors_Mode then
7462 Report_Error := True;
7463 if Try_Primitive_Operation
7464 (Call_Node => New_Call_Node,
7465 Node_To_Replace => Node_To_Replace)
7468 Try_Class_Wide_Operation
7469 (Call_Node => New_Call_Node,
7470 Node_To_Replace => Node_To_Replace)
7477 (N => New_Call_Node,
7481 Skip_First => True);
7484 -- No need for further errors
7489 -- There was no candidate operation, so report it as an error
7490 -- in the caller: Analyze_Selected_Component.
7494 end Try_Object_Operation;
7500 procedure wpo (T : Entity_Id) is
7505 if not Is_Tagged_Type (T) then
7509 E := First_Elmt (Primitive_Operations (Base_Type (T)));
7510 while Present (E) loop
7512 Write_Int (Int (Op));
7513 Write_Str (" === ");
7514 Write_Name (Chars (Op));
7516 Write_Name (Chars (Scope (Op)));