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, conditional expressions are allowed:
1528 -- * if they have no ELSE part, in which case the expression is
1530 -- NOT Condition OR ELSE Then_Expr
1531 -- * in pre- and postconditions, where the Condition cannot have side-
1532 -- effects (in ALFA) and thus the expression is equivalent to
1533 -- (Condition AND THEN Then_Expr)
1534 -- and (NOT Condition AND THEN Then_Expr)
1536 if Present (Else_Expr) and then not In_Pre_Post_Expression then
1537 Mark_Non_ALFA_Subprogram;
1540 if Comes_From_Source (N) then
1541 Check_Compiler_Unit (N);
1544 Analyze_Expression (Condition);
1545 Analyze_Expression (Then_Expr);
1547 if Present (Else_Expr) then
1548 Analyze_Expression (Else_Expr);
1551 -- If then expression not overloaded, then that decides the type
1553 if not Is_Overloaded (Then_Expr) then
1554 Set_Etype (N, Etype (Then_Expr));
1556 -- Case where then expression is overloaded
1564 Set_Etype (N, Any_Type);
1566 -- Shouldn't the following statement be down in the ELSE of the
1567 -- following loop? ???
1569 Get_First_Interp (Then_Expr, I, It);
1571 -- if no Else_Expression the conditional must be boolean
1573 if No (Else_Expr) then
1574 Set_Etype (N, Standard_Boolean);
1576 -- Else_Expression Present. For each possible intepretation of
1577 -- the Then_Expression, add it only if the Else_Expression has
1578 -- a compatible type.
1581 while Present (It.Nam) loop
1582 if Has_Compatible_Type (Else_Expr, It.Typ) then
1583 Add_One_Interp (N, It.Typ, It.Typ);
1586 Get_Next_Interp (I, It);
1591 end Analyze_Conditional_Expression;
1593 -------------------------
1594 -- Analyze_Equality_Op --
1595 -------------------------
1597 procedure Analyze_Equality_Op (N : Node_Id) is
1598 Loc : constant Source_Ptr := Sloc (N);
1599 L : constant Node_Id := Left_Opnd (N);
1600 R : constant Node_Id := Right_Opnd (N);
1604 Set_Etype (N, Any_Type);
1605 Candidate_Type := Empty;
1607 Analyze_Expression (L);
1608 Analyze_Expression (R);
1610 -- If the entity is set, the node is a generic instance with a non-local
1611 -- reference to the predefined operator or to a user-defined function.
1612 -- It can also be an inequality that is expanded into the negation of a
1613 -- call to a user-defined equality operator.
1615 -- For the predefined case, the result is Boolean, regardless of the
1616 -- type of the operands. The operands may even be limited, if they are
1617 -- generic actuals. If they are overloaded, label the left argument with
1618 -- the common type that must be present, or with the type of the formal
1619 -- of the user-defined function.
1621 if Present (Entity (N)) then
1622 Op_Id := Entity (N);
1624 if Ekind (Op_Id) = E_Operator then
1625 Add_One_Interp (N, Op_Id, Standard_Boolean);
1627 Add_One_Interp (N, Op_Id, Etype (Op_Id));
1630 if Is_Overloaded (L) then
1631 if Ekind (Op_Id) = E_Operator then
1632 Set_Etype (L, Intersect_Types (L, R));
1634 Set_Etype (L, Etype (First_Formal (Op_Id)));
1639 Op_Id := Get_Name_Entity_Id (Chars (N));
1640 while Present (Op_Id) loop
1641 if Ekind (Op_Id) = E_Operator then
1642 Find_Equality_Types (L, R, Op_Id, N);
1644 Analyze_User_Defined_Binary_Op (N, Op_Id);
1647 Op_Id := Homonym (Op_Id);
1651 -- If there was no match, and the operator is inequality, this may
1652 -- be a case where inequality has not been made explicit, as for
1653 -- tagged types. Analyze the node as the negation of an equality
1654 -- operation. This cannot be done earlier, because before analysis
1655 -- we cannot rule out the presence of an explicit inequality.
1657 if Etype (N) = Any_Type
1658 and then Nkind (N) = N_Op_Ne
1660 Op_Id := Get_Name_Entity_Id (Name_Op_Eq);
1661 while Present (Op_Id) loop
1662 if Ekind (Op_Id) = E_Operator then
1663 Find_Equality_Types (L, R, Op_Id, N);
1665 Analyze_User_Defined_Binary_Op (N, Op_Id);
1668 Op_Id := Homonym (Op_Id);
1671 if Etype (N) /= Any_Type then
1672 Op_Id := Entity (N);
1678 Left_Opnd => Left_Opnd (N),
1679 Right_Opnd => Right_Opnd (N))));
1681 Set_Entity (Right_Opnd (N), Op_Id);
1687 end Analyze_Equality_Op;
1689 ----------------------------------
1690 -- Analyze_Explicit_Dereference --
1691 ----------------------------------
1693 procedure Analyze_Explicit_Dereference (N : Node_Id) is
1694 Loc : constant Source_Ptr := Sloc (N);
1695 P : constant Node_Id := Prefix (N);
1701 function Is_Function_Type return Boolean;
1702 -- Check whether node may be interpreted as an implicit function call
1704 ----------------------
1705 -- Is_Function_Type --
1706 ----------------------
1708 function Is_Function_Type return Boolean is
1713 if not Is_Overloaded (N) then
1714 return Ekind (Base_Type (Etype (N))) = E_Subprogram_Type
1715 and then Etype (Base_Type (Etype (N))) /= Standard_Void_Type;
1718 Get_First_Interp (N, I, It);
1719 while Present (It.Nam) loop
1720 if Ekind (Base_Type (It.Typ)) /= E_Subprogram_Type
1721 or else Etype (Base_Type (It.Typ)) = Standard_Void_Type
1726 Get_Next_Interp (I, It);
1731 end Is_Function_Type;
1733 -- Start of processing for Analyze_Explicit_Dereference
1736 Mark_Non_ALFA_Subprogram;
1737 Check_SPARK_Restriction ("explicit dereference is not allowed", N);
1740 Set_Etype (N, Any_Type);
1742 -- Test for remote access to subprogram type, and if so return
1743 -- after rewriting the original tree.
1745 if Remote_AST_E_Dereference (P) then
1749 -- Normal processing for other than remote access to subprogram type
1751 if not Is_Overloaded (P) then
1752 if Is_Access_Type (Etype (P)) then
1754 -- Set the Etype. We need to go through Is_For_Access_Subtypes to
1755 -- avoid other problems caused by the Private_Subtype and it is
1756 -- safe to go to the Base_Type because this is the same as
1757 -- converting the access value to its Base_Type.
1760 DT : Entity_Id := Designated_Type (Etype (P));
1763 if Ekind (DT) = E_Private_Subtype
1764 and then Is_For_Access_Subtype (DT)
1766 DT := Base_Type (DT);
1769 -- An explicit dereference is a legal occurrence of an
1770 -- incomplete type imported through a limited_with clause,
1771 -- if the full view is visible.
1773 if From_With_Type (DT)
1774 and then not From_With_Type (Scope (DT))
1776 (Is_Immediately_Visible (Scope (DT))
1778 (Is_Child_Unit (Scope (DT))
1779 and then Is_Visible_Child_Unit (Scope (DT))))
1781 Set_Etype (N, Available_View (DT));
1788 elsif Etype (P) /= Any_Type then
1789 Error_Msg_N ("prefix of dereference must be an access type", N);
1794 Get_First_Interp (P, I, It);
1795 while Present (It.Nam) loop
1798 if Is_Access_Type (T) then
1799 Add_One_Interp (N, Designated_Type (T), Designated_Type (T));
1802 Get_Next_Interp (I, It);
1805 -- Error if no interpretation of the prefix has an access type
1807 if Etype (N) = Any_Type then
1809 ("access type required in prefix of explicit dereference", P);
1810 Set_Etype (N, Any_Type);
1816 and then Nkind (Parent (N)) /= N_Indexed_Component
1818 and then (Nkind (Parent (N)) /= N_Function_Call
1819 or else N /= Name (Parent (N)))
1821 and then (Nkind (Parent (N)) /= N_Procedure_Call_Statement
1822 or else N /= Name (Parent (N)))
1824 and then Nkind (Parent (N)) /= N_Subprogram_Renaming_Declaration
1825 and then (Nkind (Parent (N)) /= N_Attribute_Reference
1827 (Attribute_Name (Parent (N)) /= Name_Address
1829 Attribute_Name (Parent (N)) /= Name_Access))
1831 -- Name is a function call with no actuals, in a context that
1832 -- requires deproceduring (including as an actual in an enclosing
1833 -- function or procedure call). There are some pathological cases
1834 -- where the prefix might include functions that return access to
1835 -- subprograms and others that return a regular type. Disambiguation
1836 -- of those has to take place in Resolve.
1839 Make_Function_Call (Loc,
1840 Name => Make_Explicit_Dereference (Loc, P),
1841 Parameter_Associations => New_List);
1843 -- If the prefix is overloaded, remove operations that have formals,
1844 -- we know that this is a parameterless call.
1846 if Is_Overloaded (P) then
1847 Get_First_Interp (P, I, It);
1848 while Present (It.Nam) loop
1851 if No (First_Formal (Base_Type (Designated_Type (T)))) then
1857 Get_Next_Interp (I, It);
1864 elsif not Is_Function_Type
1865 and then Is_Overloaded (N)
1867 -- The prefix may include access to subprograms and other access
1868 -- types. If the context selects the interpretation that is a
1869 -- function call (not a procedure call) we cannot rewrite the node
1870 -- yet, but we include the result of the call interpretation.
1872 Get_First_Interp (N, I, It);
1873 while Present (It.Nam) loop
1874 if Ekind (Base_Type (It.Typ)) = E_Subprogram_Type
1875 and then Etype (Base_Type (It.Typ)) /= Standard_Void_Type
1876 and then Nkind (Parent (N)) /= N_Procedure_Call_Statement
1878 Add_One_Interp (N, Etype (It.Typ), Etype (It.Typ));
1881 Get_Next_Interp (I, It);
1885 -- A value of remote access-to-class-wide must not be dereferenced
1888 Validate_Remote_Access_To_Class_Wide_Type (N);
1889 end Analyze_Explicit_Dereference;
1891 ------------------------
1892 -- Analyze_Expression --
1893 ------------------------
1895 procedure Analyze_Expression (N : Node_Id) is
1898 Check_Parameterless_Call (N);
1899 end Analyze_Expression;
1901 -------------------------------------
1902 -- Analyze_Expression_With_Actions --
1903 -------------------------------------
1905 procedure Analyze_Expression_With_Actions (N : Node_Id) is
1909 A := First (Actions (N));
1916 Analyze_Expression (Expression (N));
1917 Set_Etype (N, Etype (Expression (N)));
1918 end Analyze_Expression_With_Actions;
1920 ------------------------------------
1921 -- Analyze_Indexed_Component_Form --
1922 ------------------------------------
1924 procedure Analyze_Indexed_Component_Form (N : Node_Id) is
1925 P : constant Node_Id := Prefix (N);
1926 Exprs : constant List_Id := Expressions (N);
1932 procedure Process_Function_Call;
1933 -- Prefix in indexed component form is an overloadable entity,
1934 -- so the node is a function call. Reformat it as such.
1936 procedure Process_Indexed_Component;
1937 -- Prefix in indexed component form is actually an indexed component.
1938 -- This routine processes it, knowing that the prefix is already
1941 procedure Process_Indexed_Component_Or_Slice;
1942 -- An indexed component with a single index may designate a slice if
1943 -- the index is a subtype mark. This routine disambiguates these two
1944 -- cases by resolving the prefix to see if it is a subtype mark.
1946 procedure Process_Overloaded_Indexed_Component;
1947 -- If the prefix of an indexed component is overloaded, the proper
1948 -- interpretation is selected by the index types and the context.
1950 ---------------------------
1951 -- Process_Function_Call --
1952 ---------------------------
1954 procedure Process_Function_Call is
1958 Change_Node (N, N_Function_Call);
1960 Set_Parameter_Associations (N, Exprs);
1962 -- Analyze actuals prior to analyzing the call itself
1964 Actual := First (Parameter_Associations (N));
1965 while Present (Actual) loop
1967 Check_Parameterless_Call (Actual);
1969 -- Move to next actual. Note that we use Next, not Next_Actual
1970 -- here. The reason for this is a bit subtle. If a function call
1971 -- includes named associations, the parser recognizes the node as
1972 -- a call, and it is analyzed as such. If all associations are
1973 -- positional, the parser builds an indexed_component node, and
1974 -- it is only after analysis of the prefix that the construct
1975 -- is recognized as a call, in which case Process_Function_Call
1976 -- rewrites the node and analyzes the actuals. If the list of
1977 -- actuals is malformed, the parser may leave the node as an
1978 -- indexed component (despite the presence of named associations).
1979 -- The iterator Next_Actual is equivalent to Next if the list is
1980 -- positional, but follows the normalized chain of actuals when
1981 -- named associations are present. In this case normalization has
1982 -- not taken place, and actuals remain unanalyzed, which leads to
1983 -- subsequent crashes or loops if there is an attempt to continue
1984 -- analysis of the program.
1990 end Process_Function_Call;
1992 -------------------------------
1993 -- Process_Indexed_Component --
1994 -------------------------------
1996 procedure Process_Indexed_Component is
1998 Array_Type : Entity_Id;
2000 Pent : Entity_Id := Empty;
2003 Exp := First (Exprs);
2005 if Is_Overloaded (P) then
2006 Process_Overloaded_Indexed_Component;
2009 Array_Type := Etype (P);
2011 if Is_Entity_Name (P) then
2013 elsif Nkind (P) = N_Selected_Component
2014 and then Is_Entity_Name (Selector_Name (P))
2016 Pent := Entity (Selector_Name (P));
2019 -- Prefix must be appropriate for an array type, taking into
2020 -- account a possible implicit dereference.
2022 if Is_Access_Type (Array_Type) then
2023 Error_Msg_NW (Warn_On_Dereference, "?implicit dereference", N);
2024 Array_Type := Process_Implicit_Dereference_Prefix (Pent, P);
2027 if Is_Array_Type (Array_Type) then
2030 elsif Present (Pent) and then Ekind (Pent) = E_Entry_Family then
2032 Set_Etype (N, Any_Type);
2034 if not Has_Compatible_Type
2035 (Exp, Entry_Index_Type (Pent))
2037 Error_Msg_N ("invalid index type in entry name", N);
2039 elsif Present (Next (Exp)) then
2040 Error_Msg_N ("too many subscripts in entry reference", N);
2043 Set_Etype (N, Etype (P));
2048 elsif Is_Record_Type (Array_Type)
2049 and then Remote_AST_I_Dereference (P)
2053 elsif Array_Type = Any_Type then
2054 Set_Etype (N, Any_Type);
2056 -- In most cases the analysis of the prefix will have emitted
2057 -- an error already, but if the prefix may be interpreted as a
2058 -- call in prefixed notation, the report is left to the caller.
2059 -- To prevent cascaded errors, report only if no previous ones.
2061 if Serious_Errors_Detected = 0 then
2062 Error_Msg_N ("invalid prefix in indexed component", P);
2064 if Nkind (P) = N_Expanded_Name then
2065 Error_Msg_NE ("\& is not visible", P, Selector_Name (P));
2071 -- Here we definitely have a bad indexing
2074 if Nkind (Parent (N)) = N_Requeue_Statement
2075 and then Present (Pent) and then Ekind (Pent) = E_Entry
2078 ("REQUEUE does not permit parameters", First (Exprs));
2080 elsif Is_Entity_Name (P)
2081 and then Etype (P) = Standard_Void_Type
2083 Error_Msg_NE ("incorrect use of&", P, Entity (P));
2086 Error_Msg_N ("array type required in indexed component", P);
2089 Set_Etype (N, Any_Type);
2093 Index := First_Index (Array_Type);
2094 while Present (Index) and then Present (Exp) loop
2095 if not Has_Compatible_Type (Exp, Etype (Index)) then
2096 Wrong_Type (Exp, Etype (Index));
2097 Set_Etype (N, Any_Type);
2105 Set_Etype (N, Component_Type (Array_Type));
2107 if Present (Index) then
2109 ("too few subscripts in array reference", First (Exprs));
2111 elsif Present (Exp) then
2112 Error_Msg_N ("too many subscripts in array reference", Exp);
2115 end Process_Indexed_Component;
2117 ----------------------------------------
2118 -- Process_Indexed_Component_Or_Slice --
2119 ----------------------------------------
2121 procedure Process_Indexed_Component_Or_Slice is
2123 Exp := First (Exprs);
2124 while Present (Exp) loop
2125 Analyze_Expression (Exp);
2129 Exp := First (Exprs);
2131 -- If one index is present, and it is a subtype name, then the
2132 -- node denotes a slice (note that the case of an explicit range
2133 -- for a slice was already built as an N_Slice node in the first
2134 -- place, so that case is not handled here).
2136 -- We use a replace rather than a rewrite here because this is one
2137 -- of the cases in which the tree built by the parser is plain wrong.
2140 and then Is_Entity_Name (Exp)
2141 and then Is_Type (Entity (Exp))
2144 Make_Slice (Sloc (N),
2146 Discrete_Range => New_Copy (Exp)));
2149 -- Otherwise (more than one index present, or single index is not
2150 -- a subtype name), then we have the indexed component case.
2153 Process_Indexed_Component;
2155 end Process_Indexed_Component_Or_Slice;
2157 ------------------------------------------
2158 -- Process_Overloaded_Indexed_Component --
2159 ------------------------------------------
2161 procedure Process_Overloaded_Indexed_Component is
2170 Set_Etype (N, Any_Type);
2172 Get_First_Interp (P, I, It);
2173 while Present (It.Nam) loop
2176 if Is_Access_Type (Typ) then
2177 Typ := Designated_Type (Typ);
2178 Error_Msg_NW (Warn_On_Dereference, "?implicit dereference", N);
2181 if Is_Array_Type (Typ) then
2183 -- Got a candidate: verify that index types are compatible
2185 Index := First_Index (Typ);
2187 Exp := First (Exprs);
2188 while Present (Index) and then Present (Exp) loop
2189 if Has_Compatible_Type (Exp, Etype (Index)) then
2201 if Found and then No (Index) and then No (Exp) then
2203 Etype (Component_Type (Typ)),
2204 Etype (Component_Type (Typ)));
2208 Get_Next_Interp (I, It);
2211 if Etype (N) = Any_Type then
2212 Error_Msg_N ("no legal interpretation for indexed component", N);
2213 Set_Is_Overloaded (N, False);
2217 end Process_Overloaded_Indexed_Component;
2219 -- Start of processing for Analyze_Indexed_Component_Form
2222 -- Get name of array, function or type
2226 if Nkind_In (N, N_Function_Call, N_Procedure_Call_Statement) then
2228 -- If P is an explicit dereference whose prefix is of a
2229 -- remote access-to-subprogram type, then N has already
2230 -- been rewritten as a subprogram call and analyzed.
2235 pragma Assert (Nkind (N) = N_Indexed_Component);
2237 P_T := Base_Type (Etype (P));
2239 if Is_Entity_Name (P) and then Present (Entity (P)) then
2242 if Is_Type (U_N) then
2244 -- Reformat node as a type conversion
2246 E := Remove_Head (Exprs);
2248 if Present (First (Exprs)) then
2250 ("argument of type conversion must be single expression", N);
2253 Change_Node (N, N_Type_Conversion);
2254 Set_Subtype_Mark (N, P);
2256 Set_Expression (N, E);
2258 -- After changing the node, call for the specific Analysis
2259 -- routine directly, to avoid a double call to the expander.
2261 Analyze_Type_Conversion (N);
2265 if Is_Overloadable (U_N) then
2266 Process_Function_Call;
2268 elsif Ekind (Etype (P)) = E_Subprogram_Type
2269 or else (Is_Access_Type (Etype (P))
2271 Ekind (Designated_Type (Etype (P))) =
2274 -- Call to access_to-subprogram with possible implicit dereference
2276 Process_Function_Call;
2278 elsif Is_Generic_Subprogram (U_N) then
2280 -- A common beginner's (or C++ templates fan) error
2282 Error_Msg_N ("generic subprogram cannot be called", N);
2283 Set_Etype (N, Any_Type);
2287 Process_Indexed_Component_Or_Slice;
2290 -- If not an entity name, prefix is an expression that may denote
2291 -- an array or an access-to-subprogram.
2294 if Ekind (P_T) = E_Subprogram_Type
2295 or else (Is_Access_Type (P_T)
2297 Ekind (Designated_Type (P_T)) = E_Subprogram_Type)
2299 Process_Function_Call;
2301 elsif Nkind (P) = N_Selected_Component
2302 and then Is_Overloadable (Entity (Selector_Name (P)))
2304 Process_Function_Call;
2307 -- Indexed component, slice, or a call to a member of a family
2308 -- entry, which will be converted to an entry call later.
2310 Process_Indexed_Component_Or_Slice;
2313 end Analyze_Indexed_Component_Form;
2315 ------------------------
2316 -- Analyze_Logical_Op --
2317 ------------------------
2319 procedure Analyze_Logical_Op (N : Node_Id) is
2320 L : constant Node_Id := Left_Opnd (N);
2321 R : constant Node_Id := Right_Opnd (N);
2322 Op_Id : Entity_Id := Entity (N);
2325 Set_Etype (N, Any_Type);
2326 Candidate_Type := Empty;
2328 Analyze_Expression (L);
2329 Analyze_Expression (R);
2331 if Present (Op_Id) then
2333 if Ekind (Op_Id) = E_Operator then
2334 Find_Boolean_Types (L, R, Op_Id, N);
2336 Add_One_Interp (N, Op_Id, Etype (Op_Id));
2340 Op_Id := Get_Name_Entity_Id (Chars (N));
2341 while Present (Op_Id) loop
2342 if Ekind (Op_Id) = E_Operator then
2343 Find_Boolean_Types (L, R, Op_Id, N);
2345 Analyze_User_Defined_Binary_Op (N, Op_Id);
2348 Op_Id := Homonym (Op_Id);
2353 end Analyze_Logical_Op;
2355 ---------------------------
2356 -- Analyze_Membership_Op --
2357 ---------------------------
2359 procedure Analyze_Membership_Op (N : Node_Id) is
2360 Loc : constant Source_Ptr := Sloc (N);
2361 L : constant Node_Id := Left_Opnd (N);
2362 R : constant Node_Id := Right_Opnd (N);
2364 Index : Interp_Index;
2366 Found : Boolean := False;
2370 procedure Try_One_Interp (T1 : Entity_Id);
2371 -- Routine to try one proposed interpretation. Note that the context
2372 -- of the operation plays no role in resolving the arguments, so that
2373 -- if there is more than one interpretation of the operands that is
2374 -- compatible with a membership test, the operation is ambiguous.
2376 --------------------
2377 -- Try_One_Interp --
2378 --------------------
2380 procedure Try_One_Interp (T1 : Entity_Id) is
2382 if Has_Compatible_Type (R, T1) then
2384 and then Base_Type (T1) /= Base_Type (T_F)
2386 It := Disambiguate (L, I_F, Index, Any_Type);
2388 if It = No_Interp then
2389 Ambiguous_Operands (N);
2390 Set_Etype (L, Any_Type);
2407 procedure Analyze_Set_Membership;
2408 -- If a set of alternatives is present, analyze each and find the
2409 -- common type to which they must all resolve.
2411 ----------------------------
2412 -- Analyze_Set_Membership --
2413 ----------------------------
2415 procedure Analyze_Set_Membership is
2417 Index : Interp_Index;
2419 Candidate_Interps : Node_Id;
2420 Common_Type : Entity_Id := Empty;
2424 Candidate_Interps := L;
2426 if not Is_Overloaded (L) then
2427 Common_Type := Etype (L);
2429 Alt := First (Alternatives (N));
2430 while Present (Alt) loop
2433 if not Has_Compatible_Type (Alt, Common_Type) then
2434 Wrong_Type (Alt, Common_Type);
2441 Alt := First (Alternatives (N));
2442 while Present (Alt) loop
2444 if not Is_Overloaded (Alt) then
2445 Common_Type := Etype (Alt);
2448 Get_First_Interp (Alt, Index, It);
2449 while Present (It.Typ) loop
2451 Has_Compatible_Type (Candidate_Interps, It.Typ)
2453 Remove_Interp (Index);
2456 Get_Next_Interp (Index, It);
2459 Get_First_Interp (Alt, Index, It);
2462 Error_Msg_N ("alternative has no legal type", Alt);
2466 -- If alternative is not overloaded, we have a unique type
2469 Set_Etype (Alt, It.Typ);
2470 Get_Next_Interp (Index, It);
2473 Set_Is_Overloaded (Alt, False);
2474 Common_Type := Etype (Alt);
2477 Candidate_Interps := Alt;
2484 Set_Etype (N, Standard_Boolean);
2486 if Present (Common_Type) then
2487 Set_Etype (L, Common_Type);
2488 Set_Is_Overloaded (L, False);
2491 Error_Msg_N ("cannot resolve membership operation", N);
2493 end Analyze_Set_Membership;
2495 -- Start of processing for Analyze_Membership_Op
2498 Analyze_Expression (L);
2501 and then Ada_Version >= Ada_2012
2503 Analyze_Set_Membership;
2507 if Nkind (R) = N_Range
2508 or else (Nkind (R) = N_Attribute_Reference
2509 and then Attribute_Name (R) = Name_Range)
2513 if not Is_Overloaded (L) then
2514 Try_One_Interp (Etype (L));
2517 Get_First_Interp (L, Index, It);
2518 while Present (It.Typ) loop
2519 Try_One_Interp (It.Typ);
2520 Get_Next_Interp (Index, It);
2524 -- If not a range, it can be a subtype mark, or else it is a degenerate
2525 -- membership test with a singleton value, i.e. a test for equality,
2526 -- if the types are compatible.
2530 if Is_Entity_Name (R)
2531 and then Is_Type (Entity (R))
2534 Check_Fully_Declared (Entity (R), R);
2536 elsif Ada_Version >= Ada_2012
2537 and then Has_Compatible_Type (R, Etype (L))
2539 if Nkind (N) = N_In then
2555 -- In all versions of the language, if we reach this point there
2556 -- is a previous error that will be diagnosed below.
2562 -- Compatibility between expression and subtype mark or range is
2563 -- checked during resolution. The result of the operation is Boolean
2566 Set_Etype (N, Standard_Boolean);
2568 if Comes_From_Source (N)
2569 and then Present (Right_Opnd (N))
2570 and then Is_CPP_Class (Etype (Etype (Right_Opnd (N))))
2572 Error_Msg_N ("membership test not applicable to cpp-class types", N);
2574 end Analyze_Membership_Op;
2576 ----------------------
2577 -- Analyze_Negation --
2578 ----------------------
2580 procedure Analyze_Negation (N : Node_Id) is
2581 R : constant Node_Id := Right_Opnd (N);
2582 Op_Id : Entity_Id := Entity (N);
2585 Set_Etype (N, Any_Type);
2586 Candidate_Type := Empty;
2588 Analyze_Expression (R);
2590 if Present (Op_Id) then
2591 if Ekind (Op_Id) = E_Operator then
2592 Find_Negation_Types (R, Op_Id, N);
2594 Add_One_Interp (N, Op_Id, Etype (Op_Id));
2598 Op_Id := Get_Name_Entity_Id (Chars (N));
2599 while Present (Op_Id) loop
2600 if Ekind (Op_Id) = E_Operator then
2601 Find_Negation_Types (R, Op_Id, N);
2603 Analyze_User_Defined_Unary_Op (N, Op_Id);
2606 Op_Id := Homonym (Op_Id);
2611 end Analyze_Negation;
2617 procedure Analyze_Null (N : Node_Id) is
2619 Mark_Non_ALFA_Subprogram;
2620 Check_SPARK_Restriction ("null is not allowed", N);
2622 Set_Etype (N, Any_Access);
2625 ----------------------
2626 -- Analyze_One_Call --
2627 ----------------------
2629 procedure Analyze_One_Call
2633 Success : out Boolean;
2634 Skip_First : Boolean := False)
2636 Actuals : constant List_Id := Parameter_Associations (N);
2637 Prev_T : constant Entity_Id := Etype (N);
2639 Must_Skip : constant Boolean := Skip_First
2640 or else Nkind (Original_Node (N)) = N_Selected_Component
2642 (Nkind (Original_Node (N)) = N_Indexed_Component
2643 and then Nkind (Prefix (Original_Node (N)))
2644 = N_Selected_Component);
2645 -- The first formal must be omitted from the match when trying to find
2646 -- a primitive operation that is a possible interpretation, and also
2647 -- after the call has been rewritten, because the corresponding actual
2648 -- is already known to be compatible, and because this may be an
2649 -- indexing of a call with default parameters.
2653 Is_Indexed : Boolean := False;
2654 Is_Indirect : Boolean := False;
2655 Subp_Type : constant Entity_Id := Etype (Nam);
2658 function Operator_Hidden_By (Fun : Entity_Id) return Boolean;
2659 -- There may be a user-defined operator that hides the current
2660 -- interpretation. We must check for this independently of the
2661 -- analysis of the call with the user-defined operation, because
2662 -- the parameter names may be wrong and yet the hiding takes place.
2663 -- This fixes a problem with ACATS test B34014O.
2665 -- When the type Address is a visible integer type, and the DEC
2666 -- system extension is visible, the predefined operator may be
2667 -- hidden as well, by one of the address operations in auxdec.
2668 -- Finally, The abstract operations on address do not hide the
2669 -- predefined operator (this is the purpose of making them abstract).
2671 procedure Indicate_Name_And_Type;
2672 -- If candidate interpretation matches, indicate name and type of
2673 -- result on call node.
2675 ----------------------------
2676 -- Indicate_Name_And_Type --
2677 ----------------------------
2679 procedure Indicate_Name_And_Type is
2681 Add_One_Interp (N, Nam, Etype (Nam));
2684 -- If the prefix of the call is a name, indicate the entity
2685 -- being called. If it is not a name, it is an expression that
2686 -- denotes an access to subprogram or else an entry or family. In
2687 -- the latter case, the name is a selected component, and the entity
2688 -- being called is noted on the selector.
2690 if not Is_Type (Nam) then
2691 if Is_Entity_Name (Name (N)) then
2692 Set_Entity (Name (N), Nam);
2694 elsif Nkind (Name (N)) = N_Selected_Component then
2695 Set_Entity (Selector_Name (Name (N)), Nam);
2699 if Debug_Flag_E and not Report then
2700 Write_Str (" Overloaded call ");
2701 Write_Int (Int (N));
2702 Write_Str (" compatible with ");
2703 Write_Int (Int (Nam));
2706 end Indicate_Name_And_Type;
2708 ------------------------
2709 -- Operator_Hidden_By --
2710 ------------------------
2712 function Operator_Hidden_By (Fun : Entity_Id) return Boolean is
2713 Act1 : constant Node_Id := First_Actual (N);
2714 Act2 : constant Node_Id := Next_Actual (Act1);
2715 Form1 : constant Entity_Id := First_Formal (Fun);
2716 Form2 : constant Entity_Id := Next_Formal (Form1);
2719 if Ekind (Fun) /= E_Function
2720 or else Is_Abstract_Subprogram (Fun)
2724 elsif not Has_Compatible_Type (Act1, Etype (Form1)) then
2727 elsif Present (Form2) then
2729 No (Act2) or else not Has_Compatible_Type (Act2, Etype (Form2))
2734 elsif Present (Act2) then
2738 -- Now we know that the arity of the operator matches the function,
2739 -- and the function call is a valid interpretation. The function
2740 -- hides the operator if it has the right signature, or if one of
2741 -- its operands is a non-abstract operation on Address when this is
2742 -- a visible integer type.
2744 return Hides_Op (Fun, Nam)
2745 or else Is_Descendent_Of_Address (Etype (Form1))
2748 and then Is_Descendent_Of_Address (Etype (Form2)));
2749 end Operator_Hidden_By;
2751 -- Start of processing for Analyze_One_Call
2756 -- If the subprogram has no formals or if all the formals have defaults,
2757 -- and the return type is an array type, the node may denote an indexing
2758 -- of the result of a parameterless call. In Ada 2005, the subprogram
2759 -- may have one non-defaulted formal, and the call may have been written
2760 -- in prefix notation, so that the rebuilt parameter list has more than
2763 if not Is_Overloadable (Nam)
2764 and then Ekind (Nam) /= E_Subprogram_Type
2765 and then Ekind (Nam) /= E_Entry_Family
2770 -- An indexing requires at least one actual
2772 if not Is_Empty_List (Actuals)
2774 (Needs_No_Actuals (Nam)
2776 (Needs_One_Actual (Nam)
2777 and then Present (Next_Actual (First (Actuals)))))
2779 if Is_Array_Type (Subp_Type) then
2780 Is_Indexed := Try_Indexed_Call (N, Nam, Subp_Type, Must_Skip);
2782 elsif Is_Access_Type (Subp_Type)
2783 and then Is_Array_Type (Designated_Type (Subp_Type))
2787 (N, Nam, Designated_Type (Subp_Type), Must_Skip);
2789 -- The prefix can also be a parameterless function that returns an
2790 -- access to subprogram, in which case this is an indirect call.
2791 -- If this succeeds, an explicit dereference is added later on,
2792 -- in Analyze_Call or Resolve_Call.
2794 elsif Is_Access_Type (Subp_Type)
2795 and then Ekind (Designated_Type (Subp_Type)) = E_Subprogram_Type
2797 Is_Indirect := Try_Indirect_Call (N, Nam, Subp_Type);
2802 -- If the call has been transformed into a slice, it is of the form
2803 -- F (Subtype) where F is parameterless. The node has been rewritten in
2804 -- Try_Indexed_Call and there is nothing else to do.
2807 and then Nkind (N) = N_Slice
2813 (N, Nam, (Report and not Is_Indexed and not Is_Indirect), Norm_OK);
2817 -- If an indirect call is a possible interpretation, indicate
2818 -- success to the caller.
2824 -- Mismatch in number or names of parameters
2826 elsif Debug_Flag_E then
2827 Write_Str (" normalization fails in call ");
2828 Write_Int (Int (N));
2829 Write_Str (" with subprogram ");
2830 Write_Int (Int (Nam));
2834 -- If the context expects a function call, discard any interpretation
2835 -- that is a procedure. If the node is not overloaded, leave as is for
2836 -- better error reporting when type mismatch is found.
2838 elsif Nkind (N) = N_Function_Call
2839 and then Is_Overloaded (Name (N))
2840 and then Ekind (Nam) = E_Procedure
2844 -- Ditto for function calls in a procedure context
2846 elsif Nkind (N) = N_Procedure_Call_Statement
2847 and then Is_Overloaded (Name (N))
2848 and then Etype (Nam) /= Standard_Void_Type
2852 elsif No (Actuals) then
2854 -- If Normalize succeeds, then there are default parameters for
2857 Indicate_Name_And_Type;
2859 elsif Ekind (Nam) = E_Operator then
2860 if Nkind (N) = N_Procedure_Call_Statement then
2864 -- This can occur when the prefix of the call is an operator
2865 -- name or an expanded name whose selector is an operator name.
2867 Analyze_Operator_Call (N, Nam);
2869 if Etype (N) /= Prev_T then
2871 -- Check that operator is not hidden by a function interpretation
2873 if Is_Overloaded (Name (N)) then
2879 Get_First_Interp (Name (N), I, It);
2880 while Present (It.Nam) loop
2881 if Operator_Hidden_By (It.Nam) then
2882 Set_Etype (N, Prev_T);
2886 Get_Next_Interp (I, It);
2891 -- If operator matches formals, record its name on the call.
2892 -- If the operator is overloaded, Resolve will select the
2893 -- correct one from the list of interpretations. The call
2894 -- node itself carries the first candidate.
2896 Set_Entity (Name (N), Nam);
2899 elsif Report and then Etype (N) = Any_Type then
2900 Error_Msg_N ("incompatible arguments for operator", N);
2904 -- Normalize_Actuals has chained the named associations in the
2905 -- correct order of the formals.
2907 Actual := First_Actual (N);
2908 Formal := First_Formal (Nam);
2910 -- If we are analyzing a call rewritten from object notation, skip
2911 -- first actual, which may be rewritten later as an explicit
2915 Next_Actual (Actual);
2916 Next_Formal (Formal);
2919 while Present (Actual) and then Present (Formal) loop
2920 if Nkind (Parent (Actual)) /= N_Parameter_Association
2921 or else Chars (Selector_Name (Parent (Actual))) = Chars (Formal)
2923 -- The actual can be compatible with the formal, but we must
2924 -- also check that the context is not an address type that is
2925 -- visibly an integer type, as is the case in VMS_64. In this
2926 -- case the use of literals is illegal, except in the body of
2927 -- descendents of system, where arithmetic operations on
2928 -- address are of course used.
2930 if Has_Compatible_Type (Actual, Etype (Formal))
2932 (Etype (Actual) /= Universal_Integer
2933 or else not Is_Descendent_Of_Address (Etype (Formal))
2935 Is_Predefined_File_Name
2936 (Unit_File_Name (Get_Source_Unit (N))))
2938 Next_Actual (Actual);
2939 Next_Formal (Formal);
2942 if Debug_Flag_E then
2943 Write_Str (" type checking fails in call ");
2944 Write_Int (Int (N));
2945 Write_Str (" with formal ");
2946 Write_Int (Int (Formal));
2947 Write_Str (" in subprogram ");
2948 Write_Int (Int (Nam));
2952 if Report and not Is_Indexed and not Is_Indirect then
2954 -- Ada 2005 (AI-251): Complete the error notification
2955 -- to help new Ada 2005 users.
2957 if Is_Class_Wide_Type (Etype (Formal))
2958 and then Is_Interface (Etype (Etype (Formal)))
2959 and then not Interface_Present_In_Ancestor
2960 (Typ => Etype (Actual),
2961 Iface => Etype (Etype (Formal)))
2964 ("(Ada 2005) does not implement interface }",
2965 Actual, Etype (Etype (Formal)));
2968 Wrong_Type (Actual, Etype (Formal));
2970 if Nkind (Actual) = N_Op_Eq
2971 and then Nkind (Left_Opnd (Actual)) = N_Identifier
2973 Formal := First_Formal (Nam);
2974 while Present (Formal) loop
2975 if Chars (Left_Opnd (Actual)) = Chars (Formal) then
2976 Error_Msg_N -- CODEFIX
2977 ("possible misspelling of `='>`!", Actual);
2981 Next_Formal (Formal);
2985 if All_Errors_Mode then
2986 Error_Msg_Sloc := Sloc (Nam);
2988 if Etype (Formal) = Any_Type then
2990 ("there is no legal actual parameter", Actual);
2993 if Is_Overloadable (Nam)
2994 and then Present (Alias (Nam))
2995 and then not Comes_From_Source (Nam)
2998 ("\\ =='> in call to inherited operation & #!",
3001 elsif Ekind (Nam) = E_Subprogram_Type then
3003 Access_To_Subprogram_Typ :
3004 constant Entity_Id :=
3006 (Associated_Node_For_Itype (Nam));
3009 "\\ =='> in call to dereference of &#!",
3010 Actual, Access_To_Subprogram_Typ);
3015 ("\\ =='> in call to &#!", Actual, Nam);
3025 -- Normalize_Actuals has verified that a default value exists
3026 -- for this formal. Current actual names a subsequent formal.
3028 Next_Formal (Formal);
3032 -- On exit, all actuals match
3034 Indicate_Name_And_Type;
3036 end Analyze_One_Call;
3038 ---------------------------
3039 -- Analyze_Operator_Call --
3040 ---------------------------
3042 procedure Analyze_Operator_Call (N : Node_Id; Op_Id : Entity_Id) is
3043 Op_Name : constant Name_Id := Chars (Op_Id);
3044 Act1 : constant Node_Id := First_Actual (N);
3045 Act2 : constant Node_Id := Next_Actual (Act1);
3048 -- Binary operator case
3050 if Present (Act2) then
3052 -- If more than two operands, then not binary operator after all
3054 if Present (Next_Actual (Act2)) then
3057 elsif Op_Name = Name_Op_Add
3058 or else Op_Name = Name_Op_Subtract
3059 or else Op_Name = Name_Op_Multiply
3060 or else Op_Name = Name_Op_Divide
3061 or else Op_Name = Name_Op_Mod
3062 or else Op_Name = Name_Op_Rem
3063 or else Op_Name = Name_Op_Expon
3065 Find_Arithmetic_Types (Act1, Act2, Op_Id, N);
3067 elsif Op_Name = Name_Op_And
3068 or else Op_Name = Name_Op_Or
3069 or else Op_Name = Name_Op_Xor
3071 Find_Boolean_Types (Act1, Act2, Op_Id, N);
3073 elsif Op_Name = Name_Op_Lt
3074 or else Op_Name = Name_Op_Le
3075 or else Op_Name = Name_Op_Gt
3076 or else Op_Name = Name_Op_Ge
3078 Find_Comparison_Types (Act1, Act2, Op_Id, N);
3080 elsif Op_Name = Name_Op_Eq
3081 or else Op_Name = Name_Op_Ne
3083 Find_Equality_Types (Act1, Act2, Op_Id, N);
3085 elsif Op_Name = Name_Op_Concat then
3086 Find_Concatenation_Types (Act1, Act2, Op_Id, N);
3088 -- Is this else null correct, or should it be an abort???
3094 -- Unary operator case
3097 if Op_Name = Name_Op_Subtract or else
3098 Op_Name = Name_Op_Add or else
3099 Op_Name = Name_Op_Abs
3101 Find_Unary_Types (Act1, Op_Id, N);
3104 Op_Name = Name_Op_Not
3106 Find_Negation_Types (Act1, Op_Id, N);
3108 -- Is this else null correct, or should it be an abort???
3114 end Analyze_Operator_Call;
3116 -------------------------------------------
3117 -- Analyze_Overloaded_Selected_Component --
3118 -------------------------------------------
3120 procedure Analyze_Overloaded_Selected_Component (N : Node_Id) is
3121 Nam : constant Node_Id := Prefix (N);
3122 Sel : constant Node_Id := Selector_Name (N);
3129 Set_Etype (Sel, Any_Type);
3131 Get_First_Interp (Nam, I, It);
3132 while Present (It.Typ) loop
3133 if Is_Access_Type (It.Typ) then
3134 T := Designated_Type (It.Typ);
3135 Error_Msg_NW (Warn_On_Dereference, "?implicit dereference", N);
3140 -- Locate the component. For a private prefix the selector can denote
3143 if Is_Record_Type (T) or else Is_Private_Type (T) then
3145 -- If the prefix is a class-wide type, the visible components are
3146 -- those of the base type.
3148 if Is_Class_Wide_Type (T) then
3152 Comp := First_Entity (T);
3153 while Present (Comp) loop
3154 if Chars (Comp) = Chars (Sel)
3155 and then Is_Visible_Component (Comp)
3158 -- AI05-105: if the context is an object renaming with
3159 -- an anonymous access type, the expected type of the
3160 -- object must be anonymous. This is a name resolution rule.
3162 if Nkind (Parent (N)) /= N_Object_Renaming_Declaration
3163 or else No (Access_Definition (Parent (N)))
3164 or else Ekind (Etype (Comp)) = E_Anonymous_Access_Type
3166 Ekind (Etype (Comp)) = E_Anonymous_Access_Subprogram_Type
3168 Set_Entity (Sel, Comp);
3169 Set_Etype (Sel, Etype (Comp));
3170 Add_One_Interp (N, Etype (Comp), Etype (Comp));
3172 -- This also specifies a candidate to resolve the name.
3173 -- Further overloading will be resolved from context.
3174 -- The selector name itself does not carry overloading
3177 Set_Etype (Nam, It.Typ);
3180 -- Named access type in the context of a renaming
3181 -- declaration with an access definition. Remove
3182 -- inapplicable candidate.
3191 elsif Is_Concurrent_Type (T) then
3192 Comp := First_Entity (T);
3193 while Present (Comp)
3194 and then Comp /= First_Private_Entity (T)
3196 if Chars (Comp) = Chars (Sel) then
3197 if Is_Overloadable (Comp) then
3198 Add_One_Interp (Sel, Comp, Etype (Comp));
3200 Set_Entity_With_Style_Check (Sel, Comp);
3201 Generate_Reference (Comp, Sel);
3204 Set_Etype (Sel, Etype (Comp));
3205 Set_Etype (N, Etype (Comp));
3206 Set_Etype (Nam, It.Typ);
3208 -- For access type case, introduce explicit dereference for
3209 -- more uniform treatment of entry calls. Do this only once
3210 -- if several interpretations yield an access type.
3212 if Is_Access_Type (Etype (Nam))
3213 and then Nkind (Nam) /= N_Explicit_Dereference
3215 Insert_Explicit_Dereference (Nam);
3217 (Warn_On_Dereference, "?implicit dereference", N);
3224 Set_Is_Overloaded (N, Is_Overloaded (Sel));
3227 Get_Next_Interp (I, It);
3230 if Etype (N) = Any_Type
3231 and then not Try_Object_Operation (N)
3233 Error_Msg_NE ("undefined selector& for overloaded prefix", N, Sel);
3234 Set_Entity (Sel, Any_Id);
3235 Set_Etype (Sel, Any_Type);
3237 end Analyze_Overloaded_Selected_Component;
3239 ----------------------------------
3240 -- Analyze_Qualified_Expression --
3241 ----------------------------------
3243 procedure Analyze_Qualified_Expression (N : Node_Id) is
3244 Mark : constant Entity_Id := Subtype_Mark (N);
3245 Expr : constant Node_Id := Expression (N);
3251 Mark_Non_ALFA_Subprogram;
3253 Analyze_Expression (Expr);
3255 Set_Etype (N, Any_Type);
3260 if T = Any_Type then
3264 Check_Fully_Declared (T, N);
3266 -- If expected type is class-wide, check for exact match before
3267 -- expansion, because if the expression is a dispatching call it
3268 -- may be rewritten as explicit dereference with class-wide result.
3269 -- If expression is overloaded, retain only interpretations that
3270 -- will yield exact matches.
3272 if Is_Class_Wide_Type (T) then
3273 if not Is_Overloaded (Expr) then
3274 if Base_Type (Etype (Expr)) /= Base_Type (T) then
3275 if Nkind (Expr) = N_Aggregate then
3276 Error_Msg_N ("type of aggregate cannot be class-wide", Expr);
3278 Wrong_Type (Expr, T);
3283 Get_First_Interp (Expr, I, It);
3285 while Present (It.Nam) loop
3286 if Base_Type (It.Typ) /= Base_Type (T) then
3290 Get_Next_Interp (I, It);
3296 end Analyze_Qualified_Expression;
3298 -----------------------------------
3299 -- Analyze_Quantified_Expression --
3300 -----------------------------------
3302 procedure Analyze_Quantified_Expression (N : Node_Id) is
3303 Loc : constant Source_Ptr := Sloc (N);
3304 Ent : constant Entity_Id :=
3306 (E_Loop, Current_Scope, Sloc (N), 'L');
3311 Mark_Non_ALFA_Subprogram;
3312 Check_SPARK_Restriction ("quantified expression is not allowed", N);
3314 Set_Etype (Ent, Standard_Void_Type);
3315 Set_Parent (Ent, N);
3317 if Present (Loop_Parameter_Specification (N)) then
3319 Make_Iteration_Scheme (Loc,
3320 Loop_Parameter_Specification =>
3321 Loop_Parameter_Specification (N));
3324 Make_Iteration_Scheme (Loc,
3325 Iterator_Specification =>
3326 Iterator_Specification (N));
3330 Set_Parent (Iterator, N);
3331 Analyze_Iteration_Scheme (Iterator);
3333 -- The loop specification may have been converted into an
3334 -- iterator specification during its analysis. Update the
3335 -- quantified node accordingly.
3337 if Present (Iterator_Specification (Iterator)) then
3338 Set_Iterator_Specification
3339 (N, Iterator_Specification (Iterator));
3340 Set_Loop_Parameter_Specification (N, Empty);
3343 Analyze (Condition (N));
3346 Set_Etype (N, Standard_Boolean);
3347 end Analyze_Quantified_Expression;
3353 procedure Analyze_Range (N : Node_Id) is
3354 L : constant Node_Id := Low_Bound (N);
3355 H : constant Node_Id := High_Bound (N);
3356 I1, I2 : Interp_Index;
3359 procedure Check_Common_Type (T1, T2 : Entity_Id);
3360 -- Verify the compatibility of two types, and choose the
3361 -- non universal one if the other is universal.
3363 procedure Check_High_Bound (T : Entity_Id);
3364 -- Test one interpretation of the low bound against all those
3365 -- of the high bound.
3367 procedure Check_Universal_Expression (N : Node_Id);
3368 -- In Ada83, reject bounds of a universal range that are not
3369 -- literals or entity names.
3371 -----------------------
3372 -- Check_Common_Type --
3373 -----------------------
3375 procedure Check_Common_Type (T1, T2 : Entity_Id) is
3377 if Covers (T1 => T1, T2 => T2)
3379 Covers (T1 => T2, T2 => T1)
3381 if T1 = Universal_Integer
3382 or else T1 = Universal_Real
3383 or else T1 = Any_Character
3385 Add_One_Interp (N, Base_Type (T2), Base_Type (T2));
3388 Add_One_Interp (N, T1, T1);
3391 Add_One_Interp (N, Base_Type (T1), Base_Type (T1));
3394 end Check_Common_Type;
3396 ----------------------
3397 -- Check_High_Bound --
3398 ----------------------
3400 procedure Check_High_Bound (T : Entity_Id) is
3402 if not Is_Overloaded (H) then
3403 Check_Common_Type (T, Etype (H));
3405 Get_First_Interp (H, I2, It2);
3406 while Present (It2.Typ) loop
3407 Check_Common_Type (T, It2.Typ);
3408 Get_Next_Interp (I2, It2);
3411 end Check_High_Bound;
3413 -----------------------------
3414 -- Is_Universal_Expression --
3415 -----------------------------
3417 procedure Check_Universal_Expression (N : Node_Id) is
3419 if Etype (N) = Universal_Integer
3420 and then Nkind (N) /= N_Integer_Literal
3421 and then not Is_Entity_Name (N)
3422 and then Nkind (N) /= N_Attribute_Reference
3424 Error_Msg_N ("illegal bound in discrete range", N);
3426 end Check_Universal_Expression;
3428 -- Start of processing for Analyze_Range
3431 Set_Etype (N, Any_Type);
3432 Analyze_Expression (L);
3433 Analyze_Expression (H);
3435 if Etype (L) = Any_Type or else Etype (H) = Any_Type then
3439 if not Is_Overloaded (L) then
3440 Check_High_Bound (Etype (L));
3442 Get_First_Interp (L, I1, It1);
3443 while Present (It1.Typ) loop
3444 Check_High_Bound (It1.Typ);
3445 Get_Next_Interp (I1, It1);
3449 -- If result is Any_Type, then we did not find a compatible pair
3451 if Etype (N) = Any_Type then
3452 Error_Msg_N ("incompatible types in range ", N);
3456 if Ada_Version = Ada_83
3458 (Nkind (Parent (N)) = N_Loop_Parameter_Specification
3459 or else Nkind (Parent (N)) = N_Constrained_Array_Definition)
3461 Check_Universal_Expression (L);
3462 Check_Universal_Expression (H);
3466 -----------------------
3467 -- Analyze_Reference --
3468 -----------------------
3470 procedure Analyze_Reference (N : Node_Id) is
3471 P : constant Node_Id := Prefix (N);
3474 Acc_Type : Entity_Id;
3477 Mark_Non_ALFA_Subprogram;
3481 -- An interesting error check, if we take the 'Reference of an object
3482 -- for which a pragma Atomic or Volatile has been given, and the type
3483 -- of the object is not Atomic or Volatile, then we are in trouble. The
3484 -- problem is that no trace of the atomic/volatile status will remain
3485 -- for the backend to respect when it deals with the resulting pointer,
3486 -- since the pointer type will not be marked atomic (it is a pointer to
3487 -- the base type of the object).
3489 -- It is not clear if that can ever occur, but in case it does, we will
3490 -- generate an error message. Not clear if this message can ever be
3491 -- generated, and pretty clear that it represents a bug if it is, still
3492 -- seems worth checking, except in CodePeer mode where we do not really
3493 -- care and don't want to bother the user.
3497 if Is_Entity_Name (P)
3498 and then Is_Object_Reference (P)
3499 and then not CodePeer_Mode
3504 if (Has_Atomic_Components (E)
3505 and then not Has_Atomic_Components (T))
3507 (Has_Volatile_Components (E)
3508 and then not Has_Volatile_Components (T))
3509 or else (Is_Atomic (E) and then not Is_Atomic (T))
3510 or else (Is_Volatile (E) and then not Is_Volatile (T))
3512 Error_Msg_N ("cannot take reference to Atomic/Volatile object", N);
3516 -- Carry on with normal processing
3518 Acc_Type := Create_Itype (E_Allocator_Type, N);
3519 Set_Etype (Acc_Type, Acc_Type);
3520 Set_Directly_Designated_Type (Acc_Type, Etype (P));
3521 Set_Etype (N, Acc_Type);
3522 end Analyze_Reference;
3524 --------------------------------
3525 -- Analyze_Selected_Component --
3526 --------------------------------
3528 -- Prefix is a record type or a task or protected type. In the latter case,
3529 -- the selector must denote a visible entry.
3531 procedure Analyze_Selected_Component (N : Node_Id) is
3532 Name : constant Node_Id := Prefix (N);
3533 Sel : constant Node_Id := Selector_Name (N);
3536 Has_Candidate : Boolean := False;
3539 Pent : Entity_Id := Empty;
3540 Prefix_Type : Entity_Id;
3542 Type_To_Use : Entity_Id;
3543 -- In most cases this is the Prefix_Type, but if the Prefix_Type is
3544 -- a class-wide type, we use its root type, whose components are
3545 -- present in the class-wide type.
3547 Is_Single_Concurrent_Object : Boolean;
3548 -- Set True if the prefix is a single task or a single protected object
3550 procedure Find_Component_In_Instance (Rec : Entity_Id);
3551 -- In an instance, a component of a private extension may not be visible
3552 -- while it was visible in the generic. Search candidate scope for a
3553 -- component with the proper identifier. This is only done if all other
3554 -- searches have failed. When the match is found (it always will be),
3555 -- the Etype of both N and Sel are set from this component, and the
3556 -- entity of Sel is set to reference this component.
3558 function Has_Mode_Conformant_Spec (Comp : Entity_Id) return Boolean;
3559 -- It is known that the parent of N denotes a subprogram call. Comp
3560 -- is an overloadable component of the concurrent type of the prefix.
3561 -- Determine whether all formals of the parent of N and Comp are mode
3562 -- conformant. If the parent node is not analyzed yet it may be an
3563 -- indexed component rather than a function call.
3565 --------------------------------
3566 -- Find_Component_In_Instance --
3567 --------------------------------
3569 procedure Find_Component_In_Instance (Rec : Entity_Id) is
3573 Comp := First_Component (Rec);
3574 while Present (Comp) loop
3575 if Chars (Comp) = Chars (Sel) then
3576 Set_Entity_With_Style_Check (Sel, Comp);
3577 Set_Etype (Sel, Etype (Comp));
3578 Set_Etype (N, Etype (Comp));
3582 Next_Component (Comp);
3585 -- This must succeed because code was legal in the generic
3587 raise Program_Error;
3588 end Find_Component_In_Instance;
3590 ------------------------------
3591 -- Has_Mode_Conformant_Spec --
3592 ------------------------------
3594 function Has_Mode_Conformant_Spec (Comp : Entity_Id) return Boolean is
3595 Comp_Param : Entity_Id;
3597 Param_Typ : Entity_Id;
3600 Comp_Param := First_Formal (Comp);
3602 if Nkind (Parent (N)) = N_Indexed_Component then
3603 Param := First (Expressions (Parent (N)));
3605 Param := First (Parameter_Associations (Parent (N)));
3608 while Present (Comp_Param)
3609 and then Present (Param)
3611 Param_Typ := Find_Parameter_Type (Param);
3613 if Present (Param_Typ)
3615 not Conforming_Types
3616 (Etype (Comp_Param), Param_Typ, Mode_Conformant)
3621 Next_Formal (Comp_Param);
3625 -- One of the specs has additional formals
3627 if Present (Comp_Param) or else Present (Param) then
3632 end Has_Mode_Conformant_Spec;
3634 -- Start of processing for Analyze_Selected_Component
3637 Set_Etype (N, Any_Type);
3639 if Is_Overloaded (Name) then
3640 Analyze_Overloaded_Selected_Component (N);
3643 elsif Etype (Name) = Any_Type then
3644 Set_Entity (Sel, Any_Id);
3645 Set_Etype (Sel, Any_Type);
3649 Prefix_Type := Etype (Name);
3652 if Is_Access_Type (Prefix_Type) then
3654 -- A RACW object can never be used as prefix of a selected component
3655 -- since that means it is dereferenced without being a controlling
3656 -- operand of a dispatching operation (RM E.2.2(16/1)). Before
3657 -- reporting an error, we must check whether this is actually a
3658 -- dispatching call in prefix form.
3660 if Is_Remote_Access_To_Class_Wide_Type (Prefix_Type)
3661 and then Comes_From_Source (N)
3663 if Try_Object_Operation (N) then
3667 ("invalid dereference of a remote access-to-class-wide value",
3671 -- Normal case of selected component applied to access type
3674 Error_Msg_NW (Warn_On_Dereference, "?implicit dereference", N);
3676 if Is_Entity_Name (Name) then
3677 Pent := Entity (Name);
3678 elsif Nkind (Name) = N_Selected_Component
3679 and then Is_Entity_Name (Selector_Name (Name))
3681 Pent := Entity (Selector_Name (Name));
3684 Prefix_Type := Process_Implicit_Dereference_Prefix (Pent, Name);
3687 -- If we have an explicit dereference of a remote access-to-class-wide
3688 -- value, then issue an error (see RM-E.2.2(16/1)). However we first
3689 -- have to check for the case of a prefix that is a controlling operand
3690 -- of a prefixed dispatching call, as the dereference is legal in that
3691 -- case. Normally this condition is checked in Validate_Remote_Access_
3692 -- To_Class_Wide_Type, but we have to defer the checking for selected
3693 -- component prefixes because of the prefixed dispatching call case.
3694 -- Note that implicit dereferences are checked for this just above.
3696 elsif Nkind (Name) = N_Explicit_Dereference
3697 and then Is_Remote_Access_To_Class_Wide_Type (Etype (Prefix (Name)))
3698 and then Comes_From_Source (N)
3700 if Try_Object_Operation (N) then
3704 ("invalid dereference of a remote access-to-class-wide value",
3709 -- (Ada 2005): if the prefix is the limited view of a type, and
3710 -- the context already includes the full view, use the full view
3711 -- in what follows, either to retrieve a component of to find
3712 -- a primitive operation. If the prefix is an explicit dereference,
3713 -- set the type of the prefix to reflect this transformation.
3714 -- If the non-limited view is itself an incomplete type, get the
3715 -- full view if available.
3717 if Is_Incomplete_Type (Prefix_Type)
3718 and then From_With_Type (Prefix_Type)
3719 and then Present (Non_Limited_View (Prefix_Type))
3721 Prefix_Type := Get_Full_View (Non_Limited_View (Prefix_Type));
3723 if Nkind (N) = N_Explicit_Dereference then
3724 Set_Etype (Prefix (N), Prefix_Type);
3727 elsif Ekind (Prefix_Type) = E_Class_Wide_Type
3728 and then From_With_Type (Prefix_Type)
3729 and then Present (Non_Limited_View (Etype (Prefix_Type)))
3732 Class_Wide_Type (Non_Limited_View (Etype (Prefix_Type)));
3734 if Nkind (N) = N_Explicit_Dereference then
3735 Set_Etype (Prefix (N), Prefix_Type);
3739 if Ekind (Prefix_Type) = E_Private_Subtype then
3740 Prefix_Type := Base_Type (Prefix_Type);
3743 Type_To_Use := Prefix_Type;
3745 -- For class-wide types, use the entity list of the root type. This
3746 -- indirection is specially important for private extensions because
3747 -- only the root type get switched (not the class-wide type).
3749 if Is_Class_Wide_Type (Prefix_Type) then
3750 Type_To_Use := Root_Type (Prefix_Type);
3753 -- If the prefix is a single concurrent object, use its name in error
3754 -- messages, rather than that of its anonymous type.
3756 Is_Single_Concurrent_Object :=
3757 Is_Concurrent_Type (Prefix_Type)
3758 and then Is_Internal_Name (Chars (Prefix_Type))
3759 and then not Is_Derived_Type (Prefix_Type)
3760 and then Is_Entity_Name (Name);
3762 Comp := First_Entity (Type_To_Use);
3764 -- If the selector has an original discriminant, the node appears in
3765 -- an instance. Replace the discriminant with the corresponding one
3766 -- in the current discriminated type. For nested generics, this must
3767 -- be done transitively, so note the new original discriminant.
3769 if Nkind (Sel) = N_Identifier
3770 and then In_Instance
3771 and then Present (Original_Discriminant (Sel))
3773 Comp := Find_Corresponding_Discriminant (Sel, Prefix_Type);
3775 -- Mark entity before rewriting, for completeness and because
3776 -- subsequent semantic checks might examine the original node.
3778 Set_Entity (Sel, Comp);
3779 Rewrite (Selector_Name (N),
3780 New_Occurrence_Of (Comp, Sloc (N)));
3781 Set_Original_Discriminant (Selector_Name (N), Comp);
3782 Set_Etype (N, Etype (Comp));
3784 if Is_Access_Type (Etype (Name)) then
3785 Insert_Explicit_Dereference (Name);
3786 Error_Msg_NW (Warn_On_Dereference, "?implicit dereference", N);
3789 elsif Is_Record_Type (Prefix_Type) then
3791 -- Find component with given name
3793 while Present (Comp) loop
3794 if Chars (Comp) = Chars (Sel)
3795 and then Is_Visible_Component (Comp)
3797 Set_Entity_With_Style_Check (Sel, Comp);
3798 Set_Etype (Sel, Etype (Comp));
3800 if Ekind (Comp) = E_Discriminant then
3801 if Is_Unchecked_Union (Base_Type (Prefix_Type)) then
3803 ("cannot reference discriminant of Unchecked_Union",
3807 if Is_Generic_Type (Prefix_Type)
3809 Is_Generic_Type (Root_Type (Prefix_Type))
3811 Set_Original_Discriminant (Sel, Comp);
3815 -- Resolve the prefix early otherwise it is not possible to
3816 -- build the actual subtype of the component: it may need
3817 -- to duplicate this prefix and duplication is only allowed
3818 -- on fully resolved expressions.
3822 -- Ada 2005 (AI-50217): Check wrong use of incomplete types or
3823 -- subtypes in a package specification.
3826 -- limited with Pkg;
3828 -- type Acc_Inc is access Pkg.T;
3830 -- N : Natural := X.all.Comp; -- ERROR, limited view
3831 -- end Pkg; -- Comp is not visible
3833 if Nkind (Name) = N_Explicit_Dereference
3834 and then From_With_Type (Etype (Prefix (Name)))
3835 and then not Is_Potentially_Use_Visible (Etype (Name))
3836 and then Nkind (Parent (Cunit_Entity (Current_Sem_Unit))) =
3837 N_Package_Specification
3840 ("premature usage of incomplete}", Prefix (Name),
3841 Etype (Prefix (Name)));
3844 -- We never need an actual subtype for the case of a selection
3845 -- for a indexed component of a non-packed array, since in
3846 -- this case gigi generates all the checks and can find the
3847 -- necessary bounds information.
3849 -- We also do not need an actual subtype for the case of a
3850 -- first, last, length, or range attribute applied to a
3851 -- non-packed array, since gigi can again get the bounds in
3852 -- these cases (gigi cannot handle the packed case, since it
3853 -- has the bounds of the packed array type, not the original
3854 -- bounds of the type). However, if the prefix is itself a
3855 -- selected component, as in a.b.c (i), gigi may regard a.b.c
3856 -- as a dynamic-sized temporary, so we do generate an actual
3857 -- subtype for this case.
3859 Parent_N := Parent (N);
3861 if not Is_Packed (Etype (Comp))
3863 ((Nkind (Parent_N) = N_Indexed_Component
3864 and then Nkind (Name) /= N_Selected_Component)
3866 (Nkind (Parent_N) = N_Attribute_Reference
3867 and then (Attribute_Name (Parent_N) = Name_First
3869 Attribute_Name (Parent_N) = Name_Last
3871 Attribute_Name (Parent_N) = Name_Length
3873 Attribute_Name (Parent_N) = Name_Range)))
3875 Set_Etype (N, Etype (Comp));
3877 -- If full analysis is not enabled, we do not generate an
3878 -- actual subtype, because in the absence of expansion
3879 -- reference to a formal of a protected type, for example,
3880 -- will not be properly transformed, and will lead to
3881 -- out-of-scope references in gigi.
3883 -- In all other cases, we currently build an actual subtype.
3884 -- It seems likely that many of these cases can be avoided,
3885 -- but right now, the front end makes direct references to the
3886 -- bounds (e.g. in generating a length check), and if we do
3887 -- not make an actual subtype, we end up getting a direct
3888 -- reference to a discriminant, which will not do.
3890 elsif Full_Analysis then
3892 Build_Actual_Subtype_Of_Component (Etype (Comp), N);
3893 Insert_Action (N, Act_Decl);
3895 if No (Act_Decl) then
3896 Set_Etype (N, Etype (Comp));
3899 -- Component type depends on discriminants. Enter the
3900 -- main attributes of the subtype.
3903 Subt : constant Entity_Id :=
3904 Defining_Identifier (Act_Decl);
3907 Set_Etype (Subt, Base_Type (Etype (Comp)));
3908 Set_Ekind (Subt, Ekind (Etype (Comp)));
3909 Set_Etype (N, Subt);
3913 -- If Full_Analysis not enabled, just set the Etype
3916 Set_Etype (N, Etype (Comp));
3922 -- If the prefix is a private extension, check only the visible
3923 -- components of the partial view. This must include the tag,
3924 -- which can appear in expanded code in a tag check.
3926 if Ekind (Type_To_Use) = E_Record_Type_With_Private
3927 and then Chars (Selector_Name (N)) /= Name_uTag
3929 exit when Comp = Last_Entity (Type_To_Use);
3935 -- Ada 2005 (AI-252): The selected component can be interpreted as
3936 -- a prefixed view of a subprogram. Depending on the context, this is
3937 -- either a name that can appear in a renaming declaration, or part
3938 -- of an enclosing call given in prefix form.
3940 -- Ada 2005 (AI05-0030): In the case of dispatching requeue, the
3941 -- selected component should resolve to a name.
3943 if Ada_Version >= Ada_2005
3944 and then Is_Tagged_Type (Prefix_Type)
3945 and then not Is_Concurrent_Type (Prefix_Type)
3947 if Nkind (Parent (N)) = N_Generic_Association
3948 or else Nkind (Parent (N)) = N_Requeue_Statement
3949 or else Nkind (Parent (N)) = N_Subprogram_Renaming_Declaration
3951 if Find_Primitive_Operation (N) then
3955 elsif Try_Object_Operation (N) then
3959 -- If the transformation fails, it will be necessary to redo the
3960 -- analysis with all errors enabled, to indicate candidate
3961 -- interpretations and reasons for each failure ???
3965 elsif Is_Private_Type (Prefix_Type) then
3967 -- Allow access only to discriminants of the type. If the type has
3968 -- no full view, gigi uses the parent type for the components, so we
3969 -- do the same here.
3971 if No (Full_View (Prefix_Type)) then
3972 Type_To_Use := Root_Type (Base_Type (Prefix_Type));
3973 Comp := First_Entity (Type_To_Use);
3976 while Present (Comp) loop
3977 if Chars (Comp) = Chars (Sel) then
3978 if Ekind (Comp) = E_Discriminant then
3979 Set_Entity_With_Style_Check (Sel, Comp);
3980 Generate_Reference (Comp, Sel);
3982 Set_Etype (Sel, Etype (Comp));
3983 Set_Etype (N, Etype (Comp));
3985 if Is_Generic_Type (Prefix_Type)
3986 or else Is_Generic_Type (Root_Type (Prefix_Type))
3988 Set_Original_Discriminant (Sel, Comp);
3991 -- Before declaring an error, check whether this is tagged
3992 -- private type and a call to a primitive operation.
3994 elsif Ada_Version >= Ada_2005
3995 and then Is_Tagged_Type (Prefix_Type)
3996 and then Try_Object_Operation (N)
4001 Error_Msg_Node_2 := First_Subtype (Prefix_Type);
4002 Error_Msg_NE ("invisible selector& for }", N, Sel);
4003 Set_Entity (Sel, Any_Id);
4004 Set_Etype (N, Any_Type);
4013 elsif Is_Concurrent_Type (Prefix_Type) then
4015 -- Find visible operation with given name. For a protected type,
4016 -- the possible candidates are discriminants, entries or protected
4017 -- procedures. For a task type, the set can only include entries or
4018 -- discriminants if the task type is not an enclosing scope. If it
4019 -- is an enclosing scope (e.g. in an inner task) then all entities
4020 -- are visible, but the prefix must denote the enclosing scope, i.e.
4021 -- can only be a direct name or an expanded name.
4023 Set_Etype (Sel, Any_Type);
4024 In_Scope := In_Open_Scopes (Prefix_Type);
4026 while Present (Comp) loop
4027 if Chars (Comp) = Chars (Sel) then
4028 if Is_Overloadable (Comp) then
4029 Add_One_Interp (Sel, Comp, Etype (Comp));
4031 -- If the prefix is tagged, the correct interpretation may
4032 -- lie in the primitive or class-wide operations of the
4033 -- type. Perform a simple conformance check to determine
4034 -- whether Try_Object_Operation should be invoked even if
4035 -- a visible entity is found.
4037 if Is_Tagged_Type (Prefix_Type)
4039 Nkind_In (Parent (N), N_Procedure_Call_Statement,
4041 N_Indexed_Component)
4042 and then Has_Mode_Conformant_Spec (Comp)
4044 Has_Candidate := True;
4047 -- Note: a selected component may not denote a component of a
4048 -- protected type (4.1.3(7)).
4050 elsif Ekind_In (Comp, E_Discriminant, E_Entry_Family)
4052 and then not Is_Protected_Type (Prefix_Type)
4053 and then Is_Entity_Name (Name))
4055 Set_Entity_With_Style_Check (Sel, Comp);
4056 Generate_Reference (Comp, Sel);
4062 Set_Etype (Sel, Etype (Comp));
4063 Set_Etype (N, Etype (Comp));
4065 if Ekind (Comp) = E_Discriminant then
4066 Set_Original_Discriminant (Sel, Comp);
4069 -- For access type case, introduce explicit dereference for
4070 -- more uniform treatment of entry calls.
4072 if Is_Access_Type (Etype (Name)) then
4073 Insert_Explicit_Dereference (Name);
4075 (Warn_On_Dereference, "?implicit dereference", N);
4081 exit when not In_Scope
4083 Comp = First_Private_Entity (Base_Type (Prefix_Type));
4086 -- If there is no visible entity with the given name or none of the
4087 -- visible entities are plausible interpretations, check whether
4088 -- there is some other primitive operation with that name.
4090 if Ada_Version >= Ada_2005
4091 and then Is_Tagged_Type (Prefix_Type)
4093 if (Etype (N) = Any_Type
4094 or else not Has_Candidate)
4095 and then Try_Object_Operation (N)
4099 -- If the context is not syntactically a procedure call, it
4100 -- may be a call to a primitive function declared outside of
4101 -- the synchronized type.
4103 -- If the context is a procedure call, there might still be
4104 -- an overloading between an entry and a primitive procedure
4105 -- declared outside of the synchronized type, called in prefix
4106 -- notation. This is harder to disambiguate because in one case
4107 -- the controlling formal is implicit ???
4109 elsif Nkind (Parent (N)) /= N_Procedure_Call_Statement
4110 and then Nkind (Parent (N)) /= N_Indexed_Component
4111 and then Try_Object_Operation (N)
4117 if Etype (N) = Any_Type and then Is_Protected_Type (Prefix_Type) then
4118 -- Case of a prefix of a protected type: selector might denote
4119 -- an invisible private component.
4121 Comp := First_Private_Entity (Base_Type (Prefix_Type));
4122 while Present (Comp) and then Chars (Comp) /= Chars (Sel) loop
4126 if Present (Comp) then
4127 if Is_Single_Concurrent_Object then
4128 Error_Msg_Node_2 := Entity (Name);
4129 Error_Msg_NE ("invisible selector& for &", N, Sel);
4132 Error_Msg_Node_2 := First_Subtype (Prefix_Type);
4133 Error_Msg_NE ("invisible selector& for }", N, Sel);
4139 Set_Is_Overloaded (N, Is_Overloaded (Sel));
4144 Error_Msg_NE ("invalid prefix in selected component&", N, Sel);
4147 -- If N still has no type, the component is not defined in the prefix
4149 if Etype (N) = Any_Type then
4151 if Is_Single_Concurrent_Object then
4152 Error_Msg_Node_2 := Entity (Name);
4153 Error_Msg_NE ("no selector& for&", N, Sel);
4155 Check_Misspelled_Selector (Type_To_Use, Sel);
4157 elsif Is_Generic_Type (Prefix_Type)
4158 and then Ekind (Prefix_Type) = E_Record_Type_With_Private
4159 and then Prefix_Type /= Etype (Prefix_Type)
4160 and then Is_Record_Type (Etype (Prefix_Type))
4162 -- If this is a derived formal type, the parent may have
4163 -- different visibility at this point. Try for an inherited
4164 -- component before reporting an error.
4166 Set_Etype (Prefix (N), Etype (Prefix_Type));
4167 Analyze_Selected_Component (N);
4170 -- Similarly, if this is the actual for a formal derived type, the
4171 -- component inherited from the generic parent may not be visible
4172 -- in the actual, but the selected component is legal.
4174 elsif Ekind (Prefix_Type) = E_Record_Subtype_With_Private
4175 and then Is_Generic_Actual_Type (Prefix_Type)
4176 and then Present (Full_View (Prefix_Type))
4179 Find_Component_In_Instance
4180 (Generic_Parent_Type (Parent (Prefix_Type)));
4183 -- Finally, the formal and the actual may be private extensions,
4184 -- but the generic is declared in a child unit of the parent, and
4185 -- an additional step is needed to retrieve the proper scope.
4188 and then Present (Parent_Subtype (Etype (Base_Type (Prefix_Type))))
4190 Find_Component_In_Instance
4191 (Parent_Subtype (Etype (Base_Type (Prefix_Type))));
4194 -- Component not found, specialize error message when appropriate
4197 if Ekind (Prefix_Type) = E_Record_Subtype then
4199 -- Check whether this is a component of the base type which
4200 -- is absent from a statically constrained subtype. This will
4201 -- raise constraint error at run time, but is not a compile-
4202 -- time error. When the selector is illegal for base type as
4203 -- well fall through and generate a compilation error anyway.
4205 Comp := First_Component (Base_Type (Prefix_Type));
4206 while Present (Comp) loop
4207 if Chars (Comp) = Chars (Sel)
4208 and then Is_Visible_Component (Comp)
4210 Set_Entity_With_Style_Check (Sel, Comp);
4211 Generate_Reference (Comp, Sel);
4212 Set_Etype (Sel, Etype (Comp));
4213 Set_Etype (N, Etype (Comp));
4215 -- Emit appropriate message. Gigi will replace the
4216 -- node subsequently with the appropriate Raise.
4218 Apply_Compile_Time_Constraint_Error
4219 (N, "component not present in }?",
4220 CE_Discriminant_Check_Failed,
4221 Ent => Prefix_Type, Rep => False);
4222 Set_Raises_Constraint_Error (N);
4226 Next_Component (Comp);
4231 Error_Msg_Node_2 := First_Subtype (Prefix_Type);
4232 Error_Msg_NE ("no selector& for}", N, Sel);
4234 Check_Misspelled_Selector (Type_To_Use, Sel);
4237 Set_Entity (Sel, Any_Id);
4238 Set_Etype (Sel, Any_Type);
4240 end Analyze_Selected_Component;
4242 ---------------------------
4243 -- Analyze_Short_Circuit --
4244 ---------------------------
4246 procedure Analyze_Short_Circuit (N : Node_Id) is
4247 L : constant Node_Id := Left_Opnd (N);
4248 R : constant Node_Id := Right_Opnd (N);
4253 Analyze_Expression (L);
4254 Analyze_Expression (R);
4255 Set_Etype (N, Any_Type);
4257 if not Is_Overloaded (L) then
4258 if Root_Type (Etype (L)) = Standard_Boolean
4259 and then Has_Compatible_Type (R, Etype (L))
4261 Add_One_Interp (N, Etype (L), Etype (L));
4265 Get_First_Interp (L, Ind, It);
4266 while Present (It.Typ) loop
4267 if Root_Type (It.Typ) = Standard_Boolean
4268 and then Has_Compatible_Type (R, It.Typ)
4270 Add_One_Interp (N, It.Typ, It.Typ);
4273 Get_Next_Interp (Ind, It);
4277 -- Here we have failed to find an interpretation. Clearly we know that
4278 -- it is not the case that both operands can have an interpretation of
4279 -- Boolean, but this is by far the most likely intended interpretation.
4280 -- So we simply resolve both operands as Booleans, and at least one of
4281 -- these resolutions will generate an error message, and we do not need
4282 -- to give another error message on the short circuit operation itself.
4284 if Etype (N) = Any_Type then
4285 Resolve (L, Standard_Boolean);
4286 Resolve (R, Standard_Boolean);
4287 Set_Etype (N, Standard_Boolean);
4289 end Analyze_Short_Circuit;
4295 procedure Analyze_Slice (N : Node_Id) is
4296 P : constant Node_Id := Prefix (N);
4297 D : constant Node_Id := Discrete_Range (N);
4298 Array_Type : Entity_Id;
4300 procedure Analyze_Overloaded_Slice;
4301 -- If the prefix is overloaded, select those interpretations that
4302 -- yield a one-dimensional array type.
4304 ------------------------------
4305 -- Analyze_Overloaded_Slice --
4306 ------------------------------
4308 procedure Analyze_Overloaded_Slice is
4314 Set_Etype (N, Any_Type);
4316 Get_First_Interp (P, I, It);
4317 while Present (It.Nam) loop
4320 if Is_Access_Type (Typ) then
4321 Typ := Designated_Type (Typ);
4322 Error_Msg_NW (Warn_On_Dereference, "?implicit dereference", N);
4325 if Is_Array_Type (Typ)
4326 and then Number_Dimensions (Typ) = 1
4327 and then Has_Compatible_Type (D, Etype (First_Index (Typ)))
4329 Add_One_Interp (N, Typ, Typ);
4332 Get_Next_Interp (I, It);
4335 if Etype (N) = Any_Type then
4336 Error_Msg_N ("expect array type in prefix of slice", N);
4338 end Analyze_Overloaded_Slice;
4340 -- Start of processing for Analyze_Slice
4343 Mark_Non_ALFA_Subprogram;
4344 Check_SPARK_Restriction ("slice is not allowed", N);
4349 if Is_Overloaded (P) then
4350 Analyze_Overloaded_Slice;
4353 Array_Type := Etype (P);
4354 Set_Etype (N, Any_Type);
4356 if Is_Access_Type (Array_Type) then
4357 Array_Type := Designated_Type (Array_Type);
4358 Error_Msg_NW (Warn_On_Dereference, "?implicit dereference", N);
4361 if not Is_Array_Type (Array_Type) then
4362 Wrong_Type (P, Any_Array);
4364 elsif Number_Dimensions (Array_Type) > 1 then
4366 ("type is not one-dimensional array in slice prefix", N);
4369 Has_Compatible_Type (D, Etype (First_Index (Array_Type)))
4371 Wrong_Type (D, Etype (First_Index (Array_Type)));
4374 Set_Etype (N, Array_Type);
4379 -----------------------------
4380 -- Analyze_Type_Conversion --
4381 -----------------------------
4383 procedure Analyze_Type_Conversion (N : Node_Id) is
4384 Expr : constant Node_Id := Expression (N);
4388 -- If Conversion_OK is set, then the Etype is already set, and the
4389 -- only processing required is to analyze the expression. This is
4390 -- used to construct certain "illegal" conversions which are not
4391 -- allowed by Ada semantics, but can be handled OK by Gigi, see
4392 -- Sinfo for further details.
4394 if Conversion_OK (N) then
4399 -- Otherwise full type analysis is required, as well as some semantic
4400 -- checks to make sure the argument of the conversion is appropriate.
4402 Find_Type (Subtype_Mark (N));
4403 T := Entity (Subtype_Mark (N));
4405 Check_Fully_Declared (T, N);
4406 Analyze_Expression (Expr);
4407 Validate_Remote_Type_Type_Conversion (N);
4409 -- Type conversion between scalar types are allowed in ALFA. All other
4410 -- type conversions are not allowed.
4412 if not (Is_Scalar_Type (Etype (Expr)) and then Is_Scalar_Type (T)) then
4413 Mark_Non_ALFA_Subprogram;
4416 -- Only remaining step is validity checks on the argument. These
4417 -- are skipped if the conversion does not come from the source.
4419 if not Comes_From_Source (N) then
4422 -- If there was an error in a generic unit, no need to replicate the
4423 -- error message. Conversely, constant-folding in the generic may
4424 -- transform the argument of a conversion into a string literal, which
4425 -- is legal. Therefore the following tests are not performed in an
4428 elsif In_Instance then
4431 elsif Nkind (Expr) = N_Null then
4432 Error_Msg_N ("argument of conversion cannot be null", N);
4433 Error_Msg_N ("\use qualified expression instead", N);
4434 Set_Etype (N, Any_Type);
4436 elsif Nkind (Expr) = N_Aggregate then
4437 Error_Msg_N ("argument of conversion cannot be aggregate", N);
4438 Error_Msg_N ("\use qualified expression instead", N);
4440 elsif Nkind (Expr) = N_Allocator then
4441 Error_Msg_N ("argument of conversion cannot be an allocator", N);
4442 Error_Msg_N ("\use qualified expression instead", N);
4444 elsif Nkind (Expr) = N_String_Literal then
4445 Error_Msg_N ("argument of conversion cannot be string literal", N);
4446 Error_Msg_N ("\use qualified expression instead", N);
4448 elsif Nkind (Expr) = N_Character_Literal then
4449 if Ada_Version = Ada_83 then
4452 Error_Msg_N ("argument of conversion cannot be character literal",
4454 Error_Msg_N ("\use qualified expression instead", N);
4457 elsif Nkind (Expr) = N_Attribute_Reference
4459 (Attribute_Name (Expr) = Name_Access or else
4460 Attribute_Name (Expr) = Name_Unchecked_Access or else
4461 Attribute_Name (Expr) = Name_Unrestricted_Access)
4463 Error_Msg_N ("argument of conversion cannot be access", N);
4464 Error_Msg_N ("\use qualified expression instead", N);
4466 end Analyze_Type_Conversion;
4468 ----------------------
4469 -- Analyze_Unary_Op --
4470 ----------------------
4472 procedure Analyze_Unary_Op (N : Node_Id) is
4473 R : constant Node_Id := Right_Opnd (N);
4474 Op_Id : Entity_Id := Entity (N);
4477 Set_Etype (N, Any_Type);
4478 Candidate_Type := Empty;
4480 Analyze_Expression (R);
4482 if Present (Op_Id) then
4483 if Ekind (Op_Id) = E_Operator then
4484 Find_Unary_Types (R, Op_Id, N);
4486 Add_One_Interp (N, Op_Id, Etype (Op_Id));
4490 Op_Id := Get_Name_Entity_Id (Chars (N));
4491 while Present (Op_Id) loop
4492 if Ekind (Op_Id) = E_Operator then
4493 if No (Next_Entity (First_Entity (Op_Id))) then
4494 Find_Unary_Types (R, Op_Id, N);
4497 elsif Is_Overloadable (Op_Id) then
4498 Analyze_User_Defined_Unary_Op (N, Op_Id);
4501 Op_Id := Homonym (Op_Id);
4506 end Analyze_Unary_Op;
4508 ----------------------------------
4509 -- Analyze_Unchecked_Expression --
4510 ----------------------------------
4512 procedure Analyze_Unchecked_Expression (N : Node_Id) is
4514 Analyze (Expression (N), Suppress => All_Checks);
4515 Set_Etype (N, Etype (Expression (N)));
4516 Save_Interps (Expression (N), N);
4517 end Analyze_Unchecked_Expression;
4519 ---------------------------------------
4520 -- Analyze_Unchecked_Type_Conversion --
4521 ---------------------------------------
4523 procedure Analyze_Unchecked_Type_Conversion (N : Node_Id) is
4525 Mark_Non_ALFA_Subprogram;
4526 Find_Type (Subtype_Mark (N));
4527 Analyze_Expression (Expression (N));
4528 Set_Etype (N, Entity (Subtype_Mark (N)));
4529 end Analyze_Unchecked_Type_Conversion;
4531 ------------------------------------
4532 -- Analyze_User_Defined_Binary_Op --
4533 ------------------------------------
4535 procedure Analyze_User_Defined_Binary_Op
4540 -- Only do analysis if the operator Comes_From_Source, since otherwise
4541 -- the operator was generated by the expander, and all such operators
4542 -- always refer to the operators in package Standard.
4544 if Comes_From_Source (N) then
4546 F1 : constant Entity_Id := First_Formal (Op_Id);
4547 F2 : constant Entity_Id := Next_Formal (F1);
4550 -- Verify that Op_Id is a visible binary function. Note that since
4551 -- we know Op_Id is overloaded, potentially use visible means use
4552 -- visible for sure (RM 9.4(11)).
4554 if Ekind (Op_Id) = E_Function
4555 and then Present (F2)
4556 and then (Is_Immediately_Visible (Op_Id)
4557 or else Is_Potentially_Use_Visible (Op_Id))
4558 and then Has_Compatible_Type (Left_Opnd (N), Etype (F1))
4559 and then Has_Compatible_Type (Right_Opnd (N), Etype (F2))
4561 Add_One_Interp (N, Op_Id, Etype (Op_Id));
4563 -- If the left operand is overloaded, indicate that the
4564 -- current type is a viable candidate. This is redundant
4565 -- in most cases, but for equality and comparison operators
4566 -- where the context does not impose a type on the operands,
4567 -- setting the proper type is necessary to avoid subsequent
4568 -- ambiguities during resolution, when both user-defined and
4569 -- predefined operators may be candidates.
4571 if Is_Overloaded (Left_Opnd (N)) then
4572 Set_Etype (Left_Opnd (N), Etype (F1));
4575 if Debug_Flag_E then
4576 Write_Str ("user defined operator ");
4577 Write_Name (Chars (Op_Id));
4578 Write_Str (" on node ");
4579 Write_Int (Int (N));
4585 end Analyze_User_Defined_Binary_Op;
4587 -----------------------------------
4588 -- Analyze_User_Defined_Unary_Op --
4589 -----------------------------------
4591 procedure Analyze_User_Defined_Unary_Op
4596 -- Only do analysis if the operator Comes_From_Source, since otherwise
4597 -- the operator was generated by the expander, and all such operators
4598 -- always refer to the operators in package Standard.
4600 if Comes_From_Source (N) then
4602 F : constant Entity_Id := First_Formal (Op_Id);
4605 -- Verify that Op_Id is a visible unary function. Note that since
4606 -- we know Op_Id is overloaded, potentially use visible means use
4607 -- visible for sure (RM 9.4(11)).
4609 if Ekind (Op_Id) = E_Function
4610 and then No (Next_Formal (F))
4611 and then (Is_Immediately_Visible (Op_Id)
4612 or else Is_Potentially_Use_Visible (Op_Id))
4613 and then Has_Compatible_Type (Right_Opnd (N), Etype (F))
4615 Add_One_Interp (N, Op_Id, Etype (Op_Id));
4619 end Analyze_User_Defined_Unary_Op;
4621 ---------------------------
4622 -- Check_Arithmetic_Pair --
4623 ---------------------------
4625 procedure Check_Arithmetic_Pair
4626 (T1, T2 : Entity_Id;
4630 Op_Name : constant Name_Id := Chars (Op_Id);
4632 function Has_Fixed_Op (Typ : Entity_Id; Op : Entity_Id) return Boolean;
4633 -- Check whether the fixed-point type Typ has a user-defined operator
4634 -- (multiplication or division) that should hide the corresponding
4635 -- predefined operator. Used to implement Ada 2005 AI-264, to make
4636 -- such operators more visible and therefore useful.
4638 -- If the name of the operation is an expanded name with prefix
4639 -- Standard, the predefined universal fixed operator is available,
4640 -- as specified by AI-420 (RM 4.5.5 (19.1/2)).
4642 function Specific_Type (T1, T2 : Entity_Id) return Entity_Id;
4643 -- Get specific type (i.e. non-universal type if there is one)
4649 function Has_Fixed_Op (Typ : Entity_Id; Op : Entity_Id) return Boolean is
4650 Bas : constant Entity_Id := Base_Type (Typ);
4656 -- If the universal_fixed operation is given explicitly the rule
4657 -- concerning primitive operations of the type do not apply.
4659 if Nkind (N) = N_Function_Call
4660 and then Nkind (Name (N)) = N_Expanded_Name
4661 and then Entity (Prefix (Name (N))) = Standard_Standard
4666 -- The operation is treated as primitive if it is declared in the
4667 -- same scope as the type, and therefore on the same entity chain.
4669 Ent := Next_Entity (Typ);
4670 while Present (Ent) loop
4671 if Chars (Ent) = Chars (Op) then
4672 F1 := First_Formal (Ent);
4673 F2 := Next_Formal (F1);
4675 -- The operation counts as primitive if either operand or
4676 -- result are of the given base type, and both operands are
4677 -- fixed point types.
4679 if (Base_Type (Etype (F1)) = Bas
4680 and then Is_Fixed_Point_Type (Etype (F2)))
4683 (Base_Type (Etype (F2)) = Bas
4684 and then Is_Fixed_Point_Type (Etype (F1)))
4687 (Base_Type (Etype (Ent)) = Bas
4688 and then Is_Fixed_Point_Type (Etype (F1))
4689 and then Is_Fixed_Point_Type (Etype (F2)))
4705 function Specific_Type (T1, T2 : Entity_Id) return Entity_Id is
4707 if T1 = Universal_Integer or else T1 = Universal_Real then
4708 return Base_Type (T2);
4710 return Base_Type (T1);
4714 -- Start of processing for Check_Arithmetic_Pair
4717 if Op_Name = Name_Op_Add or else Op_Name = Name_Op_Subtract then
4719 if Is_Numeric_Type (T1)
4720 and then Is_Numeric_Type (T2)
4721 and then (Covers (T1 => T1, T2 => T2)
4723 Covers (T1 => T2, T2 => T1))
4725 Add_One_Interp (N, Op_Id, Specific_Type (T1, T2));
4728 elsif Op_Name = Name_Op_Multiply or else Op_Name = Name_Op_Divide then
4730 if Is_Fixed_Point_Type (T1)
4731 and then (Is_Fixed_Point_Type (T2)
4732 or else T2 = Universal_Real)
4734 -- If Treat_Fixed_As_Integer is set then the Etype is already set
4735 -- and no further processing is required (this is the case of an
4736 -- operator constructed by Exp_Fixd for a fixed point operation)
4737 -- Otherwise add one interpretation with universal fixed result
4738 -- If the operator is given in functional notation, it comes
4739 -- from source and Fixed_As_Integer cannot apply.
4741 if (Nkind (N) not in N_Op
4742 or else not Treat_Fixed_As_Integer (N))
4744 (not Has_Fixed_Op (T1, Op_Id)
4745 or else Nkind (Parent (N)) = N_Type_Conversion)
4747 Add_One_Interp (N, Op_Id, Universal_Fixed);
4750 elsif Is_Fixed_Point_Type (T2)
4751 and then (Nkind (N) not in N_Op
4752 or else not Treat_Fixed_As_Integer (N))
4753 and then T1 = Universal_Real
4755 (not Has_Fixed_Op (T1, Op_Id)
4756 or else Nkind (Parent (N)) = N_Type_Conversion)
4758 Add_One_Interp (N, Op_Id, Universal_Fixed);
4760 elsif Is_Numeric_Type (T1)
4761 and then Is_Numeric_Type (T2)
4762 and then (Covers (T1 => T1, T2 => T2)
4764 Covers (T1 => T2, T2 => T1))
4766 Add_One_Interp (N, Op_Id, Specific_Type (T1, T2));
4768 elsif Is_Fixed_Point_Type (T1)
4769 and then (Base_Type (T2) = Base_Type (Standard_Integer)
4770 or else T2 = Universal_Integer)
4772 Add_One_Interp (N, Op_Id, T1);
4774 elsif T2 = Universal_Real
4775 and then Base_Type (T1) = Base_Type (Standard_Integer)
4776 and then Op_Name = Name_Op_Multiply
4778 Add_One_Interp (N, Op_Id, Any_Fixed);
4780 elsif T1 = Universal_Real
4781 and then Base_Type (T2) = Base_Type (Standard_Integer)
4783 Add_One_Interp (N, Op_Id, Any_Fixed);
4785 elsif Is_Fixed_Point_Type (T2)
4786 and then (Base_Type (T1) = Base_Type (Standard_Integer)
4787 or else T1 = Universal_Integer)
4788 and then Op_Name = Name_Op_Multiply
4790 Add_One_Interp (N, Op_Id, T2);
4792 elsif T1 = Universal_Real and then T2 = Universal_Integer then
4793 Add_One_Interp (N, Op_Id, T1);
4795 elsif T2 = Universal_Real
4796 and then T1 = Universal_Integer
4797 and then Op_Name = Name_Op_Multiply
4799 Add_One_Interp (N, Op_Id, T2);
4802 elsif Op_Name = Name_Op_Mod or else Op_Name = Name_Op_Rem then
4804 -- Note: The fixed-point operands case with Treat_Fixed_As_Integer
4805 -- set does not require any special processing, since the Etype is
4806 -- already set (case of operation constructed by Exp_Fixed).
4808 if Is_Integer_Type (T1)
4809 and then (Covers (T1 => T1, T2 => T2)
4811 Covers (T1 => T2, T2 => T1))
4813 Add_One_Interp (N, Op_Id, Specific_Type (T1, T2));
4816 elsif Op_Name = Name_Op_Expon then
4817 if Is_Numeric_Type (T1)
4818 and then not Is_Fixed_Point_Type (T1)
4819 and then (Base_Type (T2) = Base_Type (Standard_Integer)
4820 or else T2 = Universal_Integer)
4822 Add_One_Interp (N, Op_Id, Base_Type (T1));
4825 else pragma Assert (Nkind (N) in N_Op_Shift);
4827 -- If not one of the predefined operators, the node may be one
4828 -- of the intrinsic functions. Its kind is always specific, and
4829 -- we can use it directly, rather than the name of the operation.
4831 if Is_Integer_Type (T1)
4832 and then (Base_Type (T2) = Base_Type (Standard_Integer)
4833 or else T2 = Universal_Integer)
4835 Add_One_Interp (N, Op_Id, Base_Type (T1));
4838 end Check_Arithmetic_Pair;
4840 -------------------------------
4841 -- Check_Misspelled_Selector --
4842 -------------------------------
4844 procedure Check_Misspelled_Selector
4845 (Prefix : Entity_Id;
4848 Max_Suggestions : constant := 2;
4849 Nr_Of_Suggestions : Natural := 0;
4851 Suggestion_1 : Entity_Id := Empty;
4852 Suggestion_2 : Entity_Id := Empty;
4857 -- All the components of the prefix of selector Sel are matched
4858 -- against Sel and a count is maintained of possible misspellings.
4859 -- When at the end of the analysis there are one or two (not more!)
4860 -- possible misspellings, these misspellings will be suggested as
4861 -- possible correction.
4863 if not (Is_Private_Type (Prefix) or else Is_Record_Type (Prefix)) then
4865 -- Concurrent types should be handled as well ???
4870 Comp := First_Entity (Prefix);
4871 while Nr_Of_Suggestions <= Max_Suggestions and then Present (Comp) loop
4872 if Is_Visible_Component (Comp) then
4873 if Is_Bad_Spelling_Of (Chars (Comp), Chars (Sel)) then
4874 Nr_Of_Suggestions := Nr_Of_Suggestions + 1;
4876 case Nr_Of_Suggestions is
4877 when 1 => Suggestion_1 := Comp;
4878 when 2 => Suggestion_2 := Comp;
4879 when others => exit;
4884 Comp := Next_Entity (Comp);
4887 -- Report at most two suggestions
4889 if Nr_Of_Suggestions = 1 then
4890 Error_Msg_NE -- CODEFIX
4891 ("\possible misspelling of&", Sel, Suggestion_1);
4893 elsif Nr_Of_Suggestions = 2 then
4894 Error_Msg_Node_2 := Suggestion_2;
4895 Error_Msg_NE -- CODEFIX
4896 ("\possible misspelling of& or&", Sel, Suggestion_1);
4898 end Check_Misspelled_Selector;
4900 ----------------------
4901 -- Defined_In_Scope --
4902 ----------------------
4904 function Defined_In_Scope (T : Entity_Id; S : Entity_Id) return Boolean
4906 S1 : constant Entity_Id := Scope (Base_Type (T));
4909 or else (S1 = System_Aux_Id and then S = Scope (S1));
4910 end Defined_In_Scope;
4916 procedure Diagnose_Call (N : Node_Id; Nam : Node_Id) is
4922 Void_Interp_Seen : Boolean := False;
4925 pragma Warnings (Off, Boolean);
4928 if Ada_Version >= Ada_2005 then
4929 Actual := First_Actual (N);
4930 while Present (Actual) loop
4932 -- Ada 2005 (AI-50217): Post an error in case of premature
4933 -- usage of an entity from the limited view.
4935 if not Analyzed (Etype (Actual))
4936 and then From_With_Type (Etype (Actual))
4938 Error_Msg_Qual_Level := 1;
4940 ("missing with_clause for scope of imported type&",
4941 Actual, Etype (Actual));
4942 Error_Msg_Qual_Level := 0;
4945 Next_Actual (Actual);
4949 -- Analyze each candidate call again, with full error reporting
4953 ("no candidate interpretations match the actuals:!", Nam);
4954 Err_Mode := All_Errors_Mode;
4955 All_Errors_Mode := True;
4957 -- If this is a call to an operation of a concurrent type,
4958 -- the failed interpretations have been removed from the
4959 -- name. Recover them to provide full diagnostics.
4961 if Nkind (Parent (Nam)) = N_Selected_Component then
4962 Set_Entity (Nam, Empty);
4963 New_Nam := New_Copy_Tree (Parent (Nam));
4964 Set_Is_Overloaded (New_Nam, False);
4965 Set_Is_Overloaded (Selector_Name (New_Nam), False);
4966 Set_Parent (New_Nam, Parent (Parent (Nam)));
4967 Analyze_Selected_Component (New_Nam);
4968 Get_First_Interp (Selector_Name (New_Nam), X, It);
4970 Get_First_Interp (Nam, X, It);
4973 while Present (It.Nam) loop
4974 if Etype (It.Nam) = Standard_Void_Type then
4975 Void_Interp_Seen := True;
4978 Analyze_One_Call (N, It.Nam, True, Success);
4979 Get_Next_Interp (X, It);
4982 if Nkind (N) = N_Function_Call then
4983 Get_First_Interp (Nam, X, It);
4984 while Present (It.Nam) loop
4985 if Ekind_In (It.Nam, E_Function, E_Operator) then
4988 Get_Next_Interp (X, It);
4992 -- If all interpretations are procedures, this deserves a
4993 -- more precise message. Ditto if this appears as the prefix
4994 -- of a selected component, which may be a lexical error.
4997 ("\context requires function call, found procedure name", Nam);
4999 if Nkind (Parent (N)) = N_Selected_Component
5000 and then N = Prefix (Parent (N))
5002 Error_Msg_N -- CODEFIX
5003 ("\period should probably be semicolon", Parent (N));
5006 elsif Nkind (N) = N_Procedure_Call_Statement
5007 and then not Void_Interp_Seen
5010 "\function name found in procedure call", Nam);
5013 All_Errors_Mode := Err_Mode;
5016 ---------------------------
5017 -- Find_Arithmetic_Types --
5018 ---------------------------
5020 procedure Find_Arithmetic_Types
5025 Index1 : Interp_Index;
5026 Index2 : Interp_Index;
5030 procedure Check_Right_Argument (T : Entity_Id);
5031 -- Check right operand of operator
5033 --------------------------
5034 -- Check_Right_Argument --
5035 --------------------------
5037 procedure Check_Right_Argument (T : Entity_Id) is
5039 if not Is_Overloaded (R) then
5040 Check_Arithmetic_Pair (T, Etype (R), Op_Id, N);
5042 Get_First_Interp (R, Index2, It2);
5043 while Present (It2.Typ) loop
5044 Check_Arithmetic_Pair (T, It2.Typ, Op_Id, N);
5045 Get_Next_Interp (Index2, It2);
5048 end Check_Right_Argument;
5050 -- Start of processing for Find_Arithmetic_Types
5053 if not Is_Overloaded (L) then
5054 Check_Right_Argument (Etype (L));
5057 Get_First_Interp (L, Index1, It1);
5058 while Present (It1.Typ) loop
5059 Check_Right_Argument (It1.Typ);
5060 Get_Next_Interp (Index1, It1);
5064 end Find_Arithmetic_Types;
5066 ------------------------
5067 -- Find_Boolean_Types --
5068 ------------------------
5070 procedure Find_Boolean_Types
5075 Index : Interp_Index;
5078 procedure Check_Numeric_Argument (T : Entity_Id);
5079 -- Special case for logical operations one of whose operands is an
5080 -- integer literal. If both are literal the result is any modular type.
5082 ----------------------------
5083 -- Check_Numeric_Argument --
5084 ----------------------------
5086 procedure Check_Numeric_Argument (T : Entity_Id) is
5088 if T = Universal_Integer then
5089 Add_One_Interp (N, Op_Id, Any_Modular);
5091 elsif Is_Modular_Integer_Type (T) then
5092 Add_One_Interp (N, Op_Id, T);
5094 end Check_Numeric_Argument;
5096 -- Start of processing for Find_Boolean_Types
5099 if not Is_Overloaded (L) then
5100 if Etype (L) = Universal_Integer
5101 or else Etype (L) = Any_Modular
5103 if not Is_Overloaded (R) then
5104 Check_Numeric_Argument (Etype (R));
5107 Get_First_Interp (R, Index, It);
5108 while Present (It.Typ) loop
5109 Check_Numeric_Argument (It.Typ);
5110 Get_Next_Interp (Index, It);
5114 -- If operands are aggregates, we must assume that they may be
5115 -- boolean arrays, and leave disambiguation for the second pass.
5116 -- If only one is an aggregate, verify that the other one has an
5117 -- interpretation as a boolean array
5119 elsif Nkind (L) = N_Aggregate then
5120 if Nkind (R) = N_Aggregate then
5121 Add_One_Interp (N, Op_Id, Etype (L));
5123 elsif not Is_Overloaded (R) then
5124 if Valid_Boolean_Arg (Etype (R)) then
5125 Add_One_Interp (N, Op_Id, Etype (R));
5129 Get_First_Interp (R, Index, It);
5130 while Present (It.Typ) loop
5131 if Valid_Boolean_Arg (It.Typ) then
5132 Add_One_Interp (N, Op_Id, It.Typ);
5135 Get_Next_Interp (Index, It);
5139 elsif Valid_Boolean_Arg (Etype (L))
5140 and then Has_Compatible_Type (R, Etype (L))
5142 Add_One_Interp (N, Op_Id, Etype (L));
5146 Get_First_Interp (L, Index, It);
5147 while Present (It.Typ) loop
5148 if Valid_Boolean_Arg (It.Typ)
5149 and then Has_Compatible_Type (R, It.Typ)
5151 Add_One_Interp (N, Op_Id, It.Typ);
5154 Get_Next_Interp (Index, It);
5157 end Find_Boolean_Types;
5159 ---------------------------
5160 -- Find_Comparison_Types --
5161 ---------------------------
5163 procedure Find_Comparison_Types
5168 Index : Interp_Index;
5170 Found : Boolean := False;
5173 Scop : Entity_Id := Empty;
5175 procedure Try_One_Interp (T1 : Entity_Id);
5176 -- Routine to try one proposed interpretation. Note that the context
5177 -- of the operator plays no role in resolving the arguments, so that
5178 -- if there is more than one interpretation of the operands that is
5179 -- compatible with comparison, the operation is ambiguous.
5181 --------------------
5182 -- Try_One_Interp --
5183 --------------------
5185 procedure Try_One_Interp (T1 : Entity_Id) is
5188 -- If the operator is an expanded name, then the type of the operand
5189 -- must be defined in the corresponding scope. If the type is
5190 -- universal, the context will impose the correct type.
5193 and then not Defined_In_Scope (T1, Scop)
5194 and then T1 /= Universal_Integer
5195 and then T1 /= Universal_Real
5196 and then T1 /= Any_String
5197 and then T1 /= Any_Composite
5202 if Valid_Comparison_Arg (T1)
5203 and then Has_Compatible_Type (R, T1)
5206 and then Base_Type (T1) /= Base_Type (T_F)
5208 It := Disambiguate (L, I_F, Index, Any_Type);
5210 if It = No_Interp then
5211 Ambiguous_Operands (N);
5212 Set_Etype (L, Any_Type);
5226 Find_Non_Universal_Interpretations (N, R, Op_Id, T1);
5231 -- Start of processing for Find_Comparison_Types
5234 -- If left operand is aggregate, the right operand has to
5235 -- provide a usable type for it.
5237 if Nkind (L) = N_Aggregate
5238 and then Nkind (R) /= N_Aggregate
5240 Find_Comparison_Types (L => R, R => L, Op_Id => Op_Id, N => N);
5244 if Nkind (N) = N_Function_Call
5245 and then Nkind (Name (N)) = N_Expanded_Name
5247 Scop := Entity (Prefix (Name (N)));
5249 -- The prefix may be a package renaming, and the subsequent test
5250 -- requires the original package.
5252 if Ekind (Scop) = E_Package
5253 and then Present (Renamed_Entity (Scop))
5255 Scop := Renamed_Entity (Scop);
5256 Set_Entity (Prefix (Name (N)), Scop);
5260 if not Is_Overloaded (L) then
5261 Try_One_Interp (Etype (L));
5264 Get_First_Interp (L, Index, It);
5265 while Present (It.Typ) loop
5266 Try_One_Interp (It.Typ);
5267 Get_Next_Interp (Index, It);
5270 end Find_Comparison_Types;
5272 ----------------------------------------
5273 -- Find_Non_Universal_Interpretations --
5274 ----------------------------------------
5276 procedure Find_Non_Universal_Interpretations
5282 Index : Interp_Index;
5286 if T1 = Universal_Integer
5287 or else T1 = Universal_Real
5289 if not Is_Overloaded (R) then
5291 (N, Op_Id, Standard_Boolean, Base_Type (Etype (R)));
5293 Get_First_Interp (R, Index, It);
5294 while Present (It.Typ) loop
5295 if Covers (It.Typ, T1) then
5297 (N, Op_Id, Standard_Boolean, Base_Type (It.Typ));
5300 Get_Next_Interp (Index, It);
5304 Add_One_Interp (N, Op_Id, Standard_Boolean, Base_Type (T1));
5306 end Find_Non_Universal_Interpretations;
5308 ------------------------------
5309 -- Find_Concatenation_Types --
5310 ------------------------------
5312 procedure Find_Concatenation_Types
5317 Op_Type : constant Entity_Id := Etype (Op_Id);
5320 if Is_Array_Type (Op_Type)
5321 and then not Is_Limited_Type (Op_Type)
5323 and then (Has_Compatible_Type (L, Op_Type)
5325 Has_Compatible_Type (L, Component_Type (Op_Type)))
5327 and then (Has_Compatible_Type (R, Op_Type)
5329 Has_Compatible_Type (R, Component_Type (Op_Type)))
5331 Add_One_Interp (N, Op_Id, Op_Type);
5333 end Find_Concatenation_Types;
5335 -------------------------
5336 -- Find_Equality_Types --
5337 -------------------------
5339 procedure Find_Equality_Types
5344 Index : Interp_Index;
5346 Found : Boolean := False;
5349 Scop : Entity_Id := Empty;
5351 procedure Try_One_Interp (T1 : Entity_Id);
5352 -- The context of the equality operator plays no role in resolving the
5353 -- arguments, so that if there is more than one interpretation of the
5354 -- operands that is compatible with equality, the construct is ambiguous
5355 -- and an error can be emitted now, after trying to disambiguate, i.e.
5356 -- applying preference rules.
5358 --------------------
5359 -- Try_One_Interp --
5360 --------------------
5362 procedure Try_One_Interp (T1 : Entity_Id) is
5363 Bas : constant Entity_Id := Base_Type (T1);
5366 -- If the operator is an expanded name, then the type of the operand
5367 -- must be defined in the corresponding scope. If the type is
5368 -- universal, the context will impose the correct type. An anonymous
5369 -- type for a 'Access reference is also universal in this sense, as
5370 -- the actual type is obtained from context.
5371 -- In Ada 2005, the equality operator for anonymous access types
5372 -- is declared in Standard, and preference rules apply to it.
5374 if Present (Scop) then
5375 if Defined_In_Scope (T1, Scop)
5376 or else T1 = Universal_Integer
5377 or else T1 = Universal_Real
5378 or else T1 = Any_Access
5379 or else T1 = Any_String
5380 or else T1 = Any_Composite
5381 or else (Ekind (T1) = E_Access_Subprogram_Type
5382 and then not Comes_From_Source (T1))
5386 elsif Ekind (T1) = E_Anonymous_Access_Type
5387 and then Scop = Standard_Standard
5392 -- The scope does not contain an operator for the type
5397 -- If we have infix notation, the operator must be usable.
5398 -- Within an instance, if the type is already established we
5399 -- know it is correct.
5400 -- In Ada 2005, the equality on anonymous access types is declared
5401 -- in Standard, and is always visible.
5403 elsif In_Open_Scopes (Scope (Bas))
5404 or else Is_Potentially_Use_Visible (Bas)
5405 or else In_Use (Bas)
5406 or else (In_Use (Scope (Bas))
5407 and then not Is_Hidden (Bas))
5408 or else (In_Instance
5409 and then First_Subtype (T1) = First_Subtype (Etype (R)))
5410 or else Ekind (T1) = E_Anonymous_Access_Type
5415 -- Save candidate type for subsequent error message, if any
5417 if not Is_Limited_Type (T1) then
5418 Candidate_Type := T1;
5424 -- Ada 2005 (AI-230): Keep restriction imposed by Ada 83 and 95:
5425 -- Do not allow anonymous access types in equality operators.
5427 if Ada_Version < Ada_2005
5428 and then Ekind (T1) = E_Anonymous_Access_Type
5433 if T1 /= Standard_Void_Type
5434 and then not Is_Limited_Type (T1)
5435 and then not Is_Limited_Composite (T1)
5436 and then Has_Compatible_Type (R, T1)
5439 and then Base_Type (T1) /= Base_Type (T_F)
5441 It := Disambiguate (L, I_F, Index, Any_Type);
5443 if It = No_Interp then
5444 Ambiguous_Operands (N);
5445 Set_Etype (L, Any_Type);
5458 if not Analyzed (L) then
5462 Find_Non_Universal_Interpretations (N, R, Op_Id, T1);
5464 -- Case of operator was not visible, Etype still set to Any_Type
5466 if Etype (N) = Any_Type then
5470 elsif Scop = Standard_Standard
5471 and then Ekind (T1) = E_Anonymous_Access_Type
5477 -- Start of processing for Find_Equality_Types
5480 -- If left operand is aggregate, the right operand has to
5481 -- provide a usable type for it.
5483 if Nkind (L) = N_Aggregate
5484 and then Nkind (R) /= N_Aggregate
5486 Find_Equality_Types (L => R, R => L, Op_Id => Op_Id, N => N);
5490 if Nkind (N) = N_Function_Call
5491 and then Nkind (Name (N)) = N_Expanded_Name
5493 Scop := Entity (Prefix (Name (N)));
5495 -- The prefix may be a package renaming, and the subsequent test
5496 -- requires the original package.
5498 if Ekind (Scop) = E_Package
5499 and then Present (Renamed_Entity (Scop))
5501 Scop := Renamed_Entity (Scop);
5502 Set_Entity (Prefix (Name (N)), Scop);
5506 if not Is_Overloaded (L) then
5507 Try_One_Interp (Etype (L));
5510 Get_First_Interp (L, Index, It);
5511 while Present (It.Typ) loop
5512 Try_One_Interp (It.Typ);
5513 Get_Next_Interp (Index, It);
5516 end Find_Equality_Types;
5518 -------------------------
5519 -- Find_Negation_Types --
5520 -------------------------
5522 procedure Find_Negation_Types
5527 Index : Interp_Index;
5531 if not Is_Overloaded (R) then
5532 if Etype (R) = Universal_Integer then
5533 Add_One_Interp (N, Op_Id, Any_Modular);
5534 elsif Valid_Boolean_Arg (Etype (R)) then
5535 Add_One_Interp (N, Op_Id, Etype (R));
5539 Get_First_Interp (R, Index, It);
5540 while Present (It.Typ) loop
5541 if Valid_Boolean_Arg (It.Typ) then
5542 Add_One_Interp (N, Op_Id, It.Typ);
5545 Get_Next_Interp (Index, It);
5548 end Find_Negation_Types;
5550 ------------------------------
5551 -- Find_Primitive_Operation --
5552 ------------------------------
5554 function Find_Primitive_Operation (N : Node_Id) return Boolean is
5555 Obj : constant Node_Id := Prefix (N);
5556 Op : constant Node_Id := Selector_Name (N);
5563 Set_Etype (Op, Any_Type);
5565 if Is_Access_Type (Etype (Obj)) then
5566 Typ := Designated_Type (Etype (Obj));
5571 if Is_Class_Wide_Type (Typ) then
5572 Typ := Root_Type (Typ);
5575 Prims := Primitive_Operations (Typ);
5577 Prim := First_Elmt (Prims);
5578 while Present (Prim) loop
5579 if Chars (Node (Prim)) = Chars (Op) then
5580 Add_One_Interp (Op, Node (Prim), Etype (Node (Prim)));
5581 Set_Etype (N, Etype (Node (Prim)));
5587 -- Now look for class-wide operations of the type or any of its
5588 -- ancestors by iterating over the homonyms of the selector.
5591 Cls_Type : constant Entity_Id := Class_Wide_Type (Typ);
5595 Hom := Current_Entity (Op);
5596 while Present (Hom) loop
5597 if (Ekind (Hom) = E_Procedure
5599 Ekind (Hom) = E_Function)
5600 and then Scope (Hom) = Scope (Typ)
5601 and then Present (First_Formal (Hom))
5603 (Base_Type (Etype (First_Formal (Hom))) = Cls_Type
5605 (Is_Access_Type (Etype (First_Formal (Hom)))
5607 Ekind (Etype (First_Formal (Hom))) =
5608 E_Anonymous_Access_Type
5611 (Designated_Type (Etype (First_Formal (Hom)))) =
5614 Add_One_Interp (Op, Hom, Etype (Hom));
5615 Set_Etype (N, Etype (Hom));
5618 Hom := Homonym (Hom);
5622 return Etype (Op) /= Any_Type;
5623 end Find_Primitive_Operation;
5625 ----------------------
5626 -- Find_Unary_Types --
5627 ----------------------
5629 procedure Find_Unary_Types
5634 Index : Interp_Index;
5638 if not Is_Overloaded (R) then
5639 if Is_Numeric_Type (Etype (R)) then
5640 Add_One_Interp (N, Op_Id, Base_Type (Etype (R)));
5644 Get_First_Interp (R, Index, It);
5645 while Present (It.Typ) loop
5646 if Is_Numeric_Type (It.Typ) then
5647 Add_One_Interp (N, Op_Id, Base_Type (It.Typ));
5650 Get_Next_Interp (Index, It);
5653 end Find_Unary_Types;
5659 function Junk_Operand (N : Node_Id) return Boolean is
5663 if Error_Posted (N) then
5667 -- Get entity to be tested
5669 if Is_Entity_Name (N)
5670 and then Present (Entity (N))
5674 -- An odd case, a procedure name gets converted to a very peculiar
5675 -- function call, and here is where we detect this happening.
5677 elsif Nkind (N) = N_Function_Call
5678 and then Is_Entity_Name (Name (N))
5679 and then Present (Entity (Name (N)))
5683 -- Another odd case, there are at least some cases of selected
5684 -- components where the selected component is not marked as having
5685 -- an entity, even though the selector does have an entity
5687 elsif Nkind (N) = N_Selected_Component
5688 and then Present (Entity (Selector_Name (N)))
5690 Enode := Selector_Name (N);
5696 -- Now test the entity we got to see if it is a bad case
5698 case Ekind (Entity (Enode)) is
5702 ("package name cannot be used as operand", Enode);
5704 when Generic_Unit_Kind =>
5706 ("generic unit name cannot be used as operand", Enode);
5710 ("subtype name cannot be used as operand", Enode);
5714 ("entry name cannot be used as operand", Enode);
5718 ("procedure name cannot be used as operand", Enode);
5722 ("exception name cannot be used as operand", Enode);
5724 when E_Block | E_Label | E_Loop =>
5726 ("label name cannot be used as operand", Enode);
5736 --------------------
5737 -- Operator_Check --
5738 --------------------
5740 procedure Operator_Check (N : Node_Id) is
5742 Remove_Abstract_Operations (N);
5744 -- Test for case of no interpretation found for operator
5746 if Etype (N) = Any_Type then
5750 Op_Id : Entity_Id := Empty;
5753 R := Right_Opnd (N);
5755 if Nkind (N) in N_Binary_Op then
5761 -- If either operand has no type, then don't complain further,
5762 -- since this simply means that we have a propagated error.
5765 or else Etype (R) = Any_Type
5766 or else (Nkind (N) in N_Binary_Op and then Etype (L) = Any_Type)
5770 -- We explicitly check for the case of concatenation of component
5771 -- with component to avoid reporting spurious matching array types
5772 -- that might happen to be lurking in distant packages (such as
5773 -- run-time packages). This also prevents inconsistencies in the
5774 -- messages for certain ACVC B tests, which can vary depending on
5775 -- types declared in run-time interfaces. Another improvement when
5776 -- aggregates are present is to look for a well-typed operand.
5778 elsif Present (Candidate_Type)
5779 and then (Nkind (N) /= N_Op_Concat
5780 or else Is_Array_Type (Etype (L))
5781 or else Is_Array_Type (Etype (R)))
5783 if Nkind (N) = N_Op_Concat then
5784 if Etype (L) /= Any_Composite
5785 and then Is_Array_Type (Etype (L))
5787 Candidate_Type := Etype (L);
5789 elsif Etype (R) /= Any_Composite
5790 and then Is_Array_Type (Etype (R))
5792 Candidate_Type := Etype (R);
5796 Error_Msg_NE -- CODEFIX
5797 ("operator for} is not directly visible!",
5798 N, First_Subtype (Candidate_Type));
5801 U : constant Node_Id :=
5802 Cunit (Get_Source_Unit (Candidate_Type));
5804 if Unit_Is_Visible (U) then
5805 Error_Msg_N -- CODEFIX
5806 ("use clause would make operation legal!", N);
5808 Error_Msg_NE -- CODEFIX
5809 ("add with_clause and use_clause for&!",
5810 N, Defining_Entity (Unit (U)));
5815 -- If either operand is a junk operand (e.g. package name), then
5816 -- post appropriate error messages, but do not complain further.
5818 -- Note that the use of OR in this test instead of OR ELSE is
5819 -- quite deliberate, we may as well check both operands in the
5820 -- binary operator case.
5822 elsif Junk_Operand (R)
5823 or (Nkind (N) in N_Binary_Op and then Junk_Operand (L))
5827 -- If we have a logical operator, one of whose operands is
5828 -- Boolean, then we know that the other operand cannot resolve to
5829 -- Boolean (since we got no interpretations), but in that case we
5830 -- pretty much know that the other operand should be Boolean, so
5831 -- resolve it that way (generating an error)
5833 elsif Nkind_In (N, N_Op_And, N_Op_Or, N_Op_Xor) then
5834 if Etype (L) = Standard_Boolean then
5835 Resolve (R, Standard_Boolean);
5837 elsif Etype (R) = Standard_Boolean then
5838 Resolve (L, Standard_Boolean);
5842 -- For an arithmetic operator or comparison operator, if one
5843 -- of the operands is numeric, then we know the other operand
5844 -- is not the same numeric type. If it is a non-numeric type,
5845 -- then probably it is intended to match the other operand.
5847 elsif Nkind_In (N, N_Op_Add,
5853 Nkind_In (N, N_Op_Lt,
5859 if Is_Numeric_Type (Etype (L))
5860 and then not Is_Numeric_Type (Etype (R))
5862 Resolve (R, Etype (L));
5865 elsif Is_Numeric_Type (Etype (R))
5866 and then not Is_Numeric_Type (Etype (L))
5868 Resolve (L, Etype (R));
5872 -- Comparisons on A'Access are common enough to deserve a
5875 elsif Nkind_In (N, N_Op_Eq, N_Op_Ne)
5876 and then Ekind (Etype (L)) = E_Access_Attribute_Type
5877 and then Ekind (Etype (R)) = E_Access_Attribute_Type
5880 ("two access attributes cannot be compared directly", N);
5882 ("\use qualified expression for one of the operands",
5886 -- Another one for C programmers
5888 elsif Nkind (N) = N_Op_Concat
5889 and then Valid_Boolean_Arg (Etype (L))
5890 and then Valid_Boolean_Arg (Etype (R))
5892 Error_Msg_N ("invalid operands for concatenation", N);
5893 Error_Msg_N -- CODEFIX
5894 ("\maybe AND was meant", N);
5897 -- A special case for comparison of access parameter with null
5899 elsif Nkind (N) = N_Op_Eq
5900 and then Is_Entity_Name (L)
5901 and then Nkind (Parent (Entity (L))) = N_Parameter_Specification
5902 and then Nkind (Parameter_Type (Parent (Entity (L)))) =
5904 and then Nkind (R) = N_Null
5906 Error_Msg_N ("access parameter is not allowed to be null", L);
5907 Error_Msg_N ("\(call would raise Constraint_Error)", L);
5910 -- Another special case for exponentiation, where the right
5911 -- operand must be Natural, independently of the base.
5913 elsif Nkind (N) = N_Op_Expon
5914 and then Is_Numeric_Type (Etype (L))
5915 and then not Is_Overloaded (R)
5917 First_Subtype (Base_Type (Etype (R))) /= Standard_Integer
5918 and then Base_Type (Etype (R)) /= Universal_Integer
5921 ("exponent must be of type Natural, found}", R, Etype (R));
5925 -- If we fall through then just give general message. Note that in
5926 -- the following messages, if the operand is overloaded we choose
5927 -- an arbitrary type to complain about, but that is probably more
5928 -- useful than not giving a type at all.
5930 if Nkind (N) in N_Unary_Op then
5931 Error_Msg_Node_2 := Etype (R);
5932 Error_Msg_N ("operator& not defined for}", N);
5936 if Nkind (N) in N_Binary_Op then
5937 if not Is_Overloaded (L)
5938 and then not Is_Overloaded (R)
5939 and then Base_Type (Etype (L)) = Base_Type (Etype (R))
5941 Error_Msg_Node_2 := First_Subtype (Etype (R));
5942 Error_Msg_N ("there is no applicable operator& for}", N);
5945 -- Another attempt to find a fix: one of the candidate
5946 -- interpretations may not be use-visible. This has
5947 -- already been checked for predefined operators, so
5948 -- we examine only user-defined functions.
5950 Op_Id := Get_Name_Entity_Id (Chars (N));
5952 while Present (Op_Id) loop
5953 if Ekind (Op_Id) /= E_Operator
5954 and then Is_Overloadable (Op_Id)
5956 if not Is_Immediately_Visible (Op_Id)
5957 and then not In_Use (Scope (Op_Id))
5958 and then not Is_Abstract_Subprogram (Op_Id)
5959 and then not Is_Hidden (Op_Id)
5960 and then Ekind (Scope (Op_Id)) = E_Package
5963 (L, Etype (First_Formal (Op_Id)))
5965 (Next_Formal (First_Formal (Op_Id)))
5969 Etype (Next_Formal (First_Formal (Op_Id))))
5972 ("No legal interpretation for operator&", N);
5974 ("\use clause on& would make operation legal",
5980 Op_Id := Homonym (Op_Id);
5984 Error_Msg_N ("invalid operand types for operator&", N);
5986 if Nkind (N) /= N_Op_Concat then
5987 Error_Msg_NE ("\left operand has}!", N, Etype (L));
5988 Error_Msg_NE ("\right operand has}!", N, Etype (R));
5998 -----------------------------------------
5999 -- Process_Implicit_Dereference_Prefix --
6000 -----------------------------------------
6002 function Process_Implicit_Dereference_Prefix
6004 P : Entity_Id) return Entity_Id
6007 Typ : constant Entity_Id := Designated_Type (Etype (P));
6011 and then (Operating_Mode = Check_Semantics or else not Expander_Active)
6013 -- We create a dummy reference to E to ensure that the reference
6014 -- is not considered as part of an assignment (an implicit
6015 -- dereference can never assign to its prefix). The Comes_From_Source
6016 -- attribute needs to be propagated for accurate warnings.
6018 Ref := New_Reference_To (E, Sloc (P));
6019 Set_Comes_From_Source (Ref, Comes_From_Source (P));
6020 Generate_Reference (E, Ref);
6023 -- An implicit dereference is a legal occurrence of an
6024 -- incomplete type imported through a limited_with clause,
6025 -- if the full view is visible.
6027 if From_With_Type (Typ)
6028 and then not From_With_Type (Scope (Typ))
6030 (Is_Immediately_Visible (Scope (Typ))
6032 (Is_Child_Unit (Scope (Typ))
6033 and then Is_Visible_Child_Unit (Scope (Typ))))
6035 return Available_View (Typ);
6040 end Process_Implicit_Dereference_Prefix;
6042 --------------------------------
6043 -- Remove_Abstract_Operations --
6044 --------------------------------
6046 procedure Remove_Abstract_Operations (N : Node_Id) is
6047 Abstract_Op : Entity_Id := Empty;
6048 Address_Kludge : Boolean := False;
6052 -- AI-310: If overloaded, remove abstract non-dispatching operations. We
6053 -- activate this if either extensions are enabled, or if the abstract
6054 -- operation in question comes from a predefined file. This latter test
6055 -- allows us to use abstract to make operations invisible to users. In
6056 -- particular, if type Address is non-private and abstract subprograms
6057 -- are used to hide its operators, they will be truly hidden.
6059 type Operand_Position is (First_Op, Second_Op);
6060 Univ_Type : constant Entity_Id := Universal_Interpretation (N);
6062 procedure Remove_Address_Interpretations (Op : Operand_Position);
6063 -- Ambiguities may arise when the operands are literal and the address
6064 -- operations in s-auxdec are visible. In that case, remove the
6065 -- interpretation of a literal as Address, to retain the semantics of
6066 -- Address as a private type.
6068 ------------------------------------
6069 -- Remove_Address_Interpretations --
6070 ------------------------------------
6072 procedure Remove_Address_Interpretations (Op : Operand_Position) is
6076 if Is_Overloaded (N) then
6077 Get_First_Interp (N, I, It);
6078 while Present (It.Nam) loop
6079 Formal := First_Entity (It.Nam);
6081 if Op = Second_Op then
6082 Formal := Next_Entity (Formal);
6085 if Is_Descendent_Of_Address (Etype (Formal)) then
6086 Address_Kludge := True;
6090 Get_Next_Interp (I, It);
6093 end Remove_Address_Interpretations;
6095 -- Start of processing for Remove_Abstract_Operations
6098 if Is_Overloaded (N) then
6099 Get_First_Interp (N, I, It);
6101 while Present (It.Nam) loop
6102 if Is_Overloadable (It.Nam)
6103 and then Is_Abstract_Subprogram (It.Nam)
6104 and then not Is_Dispatching_Operation (It.Nam)
6106 Abstract_Op := It.Nam;
6108 if Is_Descendent_Of_Address (It.Typ) then
6109 Address_Kludge := True;
6113 -- In Ada 2005, this operation does not participate in Overload
6114 -- resolution. If the operation is defined in a predefined
6115 -- unit, it is one of the operations declared abstract in some
6116 -- variants of System, and it must be removed as well.
6118 elsif Ada_Version >= Ada_2005
6119 or else Is_Predefined_File_Name
6120 (Unit_File_Name (Get_Source_Unit (It.Nam)))
6127 Get_Next_Interp (I, It);
6130 if No (Abstract_Op) then
6132 -- If some interpretation yields an integer type, it is still
6133 -- possible that there are address interpretations. Remove them
6134 -- if one operand is a literal, to avoid spurious ambiguities
6135 -- on systems where Address is a visible integer type.
6137 if Is_Overloaded (N)
6138 and then Nkind (N) in N_Op
6139 and then Is_Integer_Type (Etype (N))
6141 if Nkind (N) in N_Binary_Op then
6142 if Nkind (Right_Opnd (N)) = N_Integer_Literal then
6143 Remove_Address_Interpretations (Second_Op);
6145 elsif Nkind (Right_Opnd (N)) = N_Integer_Literal then
6146 Remove_Address_Interpretations (First_Op);
6151 elsif Nkind (N) in N_Op then
6153 -- Remove interpretations that treat literals as addresses. This
6154 -- is never appropriate, even when Address is defined as a visible
6155 -- Integer type. The reason is that we would really prefer Address
6156 -- to behave as a private type, even in this case, which is there
6157 -- only to accommodate oddities of VMS address sizes. If Address
6158 -- is a visible integer type, we get lots of overload ambiguities.
6160 if Nkind (N) in N_Binary_Op then
6162 U1 : constant Boolean :=
6163 Present (Universal_Interpretation (Right_Opnd (N)));
6164 U2 : constant Boolean :=
6165 Present (Universal_Interpretation (Left_Opnd (N)));
6169 Remove_Address_Interpretations (Second_Op);
6173 Remove_Address_Interpretations (First_Op);
6176 if not (U1 and U2) then
6178 -- Remove corresponding predefined operator, which is
6179 -- always added to the overload set.
6181 Get_First_Interp (N, I, It);
6182 while Present (It.Nam) loop
6183 if Scope (It.Nam) = Standard_Standard
6184 and then Base_Type (It.Typ) =
6185 Base_Type (Etype (Abstract_Op))
6190 Get_Next_Interp (I, It);
6193 elsif Is_Overloaded (N)
6194 and then Present (Univ_Type)
6196 -- If both operands have a universal interpretation,
6197 -- it is still necessary to remove interpretations that
6198 -- yield Address. Any remaining ambiguities will be
6199 -- removed in Disambiguate.
6201 Get_First_Interp (N, I, It);
6202 while Present (It.Nam) loop
6203 if Is_Descendent_Of_Address (It.Typ) then
6206 elsif not Is_Type (It.Nam) then
6207 Set_Entity (N, It.Nam);
6210 Get_Next_Interp (I, It);
6216 elsif Nkind (N) = N_Function_Call
6218 (Nkind (Name (N)) = N_Operator_Symbol
6220 (Nkind (Name (N)) = N_Expanded_Name
6222 Nkind (Selector_Name (Name (N))) = N_Operator_Symbol))
6226 Arg1 : constant Node_Id := First (Parameter_Associations (N));
6227 U1 : constant Boolean :=
6228 Present (Universal_Interpretation (Arg1));
6229 U2 : constant Boolean :=
6230 Present (Next (Arg1)) and then
6231 Present (Universal_Interpretation (Next (Arg1)));
6235 Remove_Address_Interpretations (First_Op);
6239 Remove_Address_Interpretations (Second_Op);
6242 if not (U1 and U2) then
6243 Get_First_Interp (N, I, It);
6244 while Present (It.Nam) loop
6245 if Scope (It.Nam) = Standard_Standard
6246 and then It.Typ = Base_Type (Etype (Abstract_Op))
6251 Get_Next_Interp (I, It);
6257 -- If the removal has left no valid interpretations, emit an error
6258 -- message now and label node as illegal.
6260 if Present (Abstract_Op) then
6261 Get_First_Interp (N, I, It);
6265 -- Removal of abstract operation left no viable candidate
6267 Set_Etype (N, Any_Type);
6268 Error_Msg_Sloc := Sloc (Abstract_Op);
6270 ("cannot call abstract operation& declared#", N, Abstract_Op);
6272 -- In Ada 2005, an abstract operation may disable predefined
6273 -- operators. Since the context is not yet known, we mark the
6274 -- predefined operators as potentially hidden. Do not include
6275 -- predefined operators when addresses are involved since this
6276 -- case is handled separately.
6278 elsif Ada_Version >= Ada_2005
6279 and then not Address_Kludge
6281 while Present (It.Nam) loop
6282 if Is_Numeric_Type (It.Typ)
6283 and then Scope (It.Typ) = Standard_Standard
6285 Set_Abstract_Op (I, Abstract_Op);
6288 Get_Next_Interp (I, It);
6293 end Remove_Abstract_Operations;
6295 -----------------------
6296 -- Try_Indirect_Call --
6297 -----------------------
6299 function Try_Indirect_Call
6302 Typ : Entity_Id) return Boolean
6308 pragma Warnings (Off, Call_OK);
6311 Normalize_Actuals (N, Designated_Type (Typ), False, Call_OK);
6313 Actual := First_Actual (N);
6314 Formal := First_Formal (Designated_Type (Typ));
6315 while Present (Actual) and then Present (Formal) loop
6316 if not Has_Compatible_Type (Actual, Etype (Formal)) then
6321 Next_Formal (Formal);
6324 if No (Actual) and then No (Formal) then
6325 Add_One_Interp (N, Nam, Etype (Designated_Type (Typ)));
6327 -- Nam is a candidate interpretation for the name in the call,
6328 -- if it is not an indirect call.
6330 if not Is_Type (Nam)
6331 and then Is_Entity_Name (Name (N))
6333 Set_Entity (Name (N), Nam);
6340 end Try_Indirect_Call;
6342 ----------------------
6343 -- Try_Indexed_Call --
6344 ----------------------
6346 function Try_Indexed_Call
6350 Skip_First : Boolean) return Boolean
6352 Loc : constant Source_Ptr := Sloc (N);
6353 Actuals : constant List_Id := Parameter_Associations (N);
6358 Actual := First (Actuals);
6360 -- If the call was originally written in prefix form, skip the first
6361 -- actual, which is obviously not defaulted.
6367 Index := First_Index (Typ);
6368 while Present (Actual) and then Present (Index) loop
6370 -- If the parameter list has a named association, the expression
6371 -- is definitely a call and not an indexed component.
6373 if Nkind (Actual) = N_Parameter_Association then
6377 if Is_Entity_Name (Actual)
6378 and then Is_Type (Entity (Actual))
6379 and then No (Next (Actual))
6381 -- A single actual that is a type name indicates a slice if the
6382 -- type is discrete, and an error otherwise.
6384 if Is_Discrete_Type (Entity (Actual)) then
6388 Make_Function_Call (Loc,
6389 Name => Relocate_Node (Name (N))),
6391 New_Occurrence_Of (Entity (Actual), Sloc (Actual))));
6396 Error_Msg_N ("invalid use of type in expression", Actual);
6397 Set_Etype (N, Any_Type);
6402 elsif not Has_Compatible_Type (Actual, Etype (Index)) then
6410 if No (Actual) and then No (Index) then
6411 Add_One_Interp (N, Nam, Component_Type (Typ));
6413 -- Nam is a candidate interpretation for the name in the call,
6414 -- if it is not an indirect call.
6416 if not Is_Type (Nam)
6417 and then Is_Entity_Name (Name (N))
6419 Set_Entity (Name (N), Nam);
6426 end Try_Indexed_Call;
6428 --------------------------
6429 -- Try_Object_Operation --
6430 --------------------------
6432 function Try_Object_Operation (N : Node_Id) return Boolean is
6433 K : constant Node_Kind := Nkind (Parent (N));
6434 Is_Subprg_Call : constant Boolean := Nkind_In
6435 (K, N_Procedure_Call_Statement,
6437 Loc : constant Source_Ptr := Sloc (N);
6438 Obj : constant Node_Id := Prefix (N);
6440 Subprog : constant Node_Id :=
6441 Make_Identifier (Sloc (Selector_Name (N)),
6442 Chars => Chars (Selector_Name (N)));
6443 -- Identifier on which possible interpretations will be collected
6445 Report_Error : Boolean := False;
6446 -- If no candidate interpretation matches the context, redo the
6447 -- analysis with error enabled to provide additional information.
6450 Candidate : Entity_Id := Empty;
6451 New_Call_Node : Node_Id := Empty;
6452 Node_To_Replace : Node_Id;
6453 Obj_Type : Entity_Id := Etype (Obj);
6454 Success : Boolean := False;
6456 function Valid_Candidate
6459 Subp : Entity_Id) return Entity_Id;
6460 -- If the subprogram is a valid interpretation, record it, and add
6461 -- to the list of interpretations of Subprog.
6463 procedure Complete_Object_Operation
6464 (Call_Node : Node_Id;
6465 Node_To_Replace : Node_Id);
6466 -- Make Subprog the name of Call_Node, replace Node_To_Replace with
6467 -- Call_Node, insert the object (or its dereference) as the first actual
6468 -- in the call, and complete the analysis of the call.
6470 procedure Report_Ambiguity (Op : Entity_Id);
6471 -- If a prefixed procedure call is ambiguous, indicate whether the
6472 -- call includes an implicit dereference or an implicit 'Access.
6474 procedure Transform_Object_Operation
6475 (Call_Node : out Node_Id;
6476 Node_To_Replace : out Node_Id);
6477 -- Transform Obj.Operation (X, Y,,) into Operation (Obj, X, Y ..)
6478 -- Call_Node is the resulting subprogram call, Node_To_Replace is
6479 -- either N or the parent of N, and Subprog is a reference to the
6480 -- subprogram we are trying to match.
6482 function Try_Class_Wide_Operation
6483 (Call_Node : Node_Id;
6484 Node_To_Replace : Node_Id) return Boolean;
6485 -- Traverse all ancestor types looking for a class-wide subprogram
6486 -- for which the current operation is a valid non-dispatching call.
6488 procedure Try_One_Prefix_Interpretation (T : Entity_Id);
6489 -- If prefix is overloaded, its interpretation may include different
6490 -- tagged types, and we must examine the primitive operations and
6491 -- the class-wide operations of each in order to find candidate
6492 -- interpretations for the call as a whole.
6494 function Try_Primitive_Operation
6495 (Call_Node : Node_Id;
6496 Node_To_Replace : Node_Id) return Boolean;
6497 -- Traverse the list of primitive subprograms looking for a dispatching
6498 -- operation for which the current node is a valid call .
6500 ---------------------
6501 -- Valid_Candidate --
6502 ---------------------
6504 function Valid_Candidate
6507 Subp : Entity_Id) return Entity_Id
6509 Arr_Type : Entity_Id;
6510 Comp_Type : Entity_Id;
6513 -- If the subprogram is a valid interpretation, record it in global
6514 -- variable Subprog, to collect all possible overloadings.
6517 if Subp /= Entity (Subprog) then
6518 Add_One_Interp (Subprog, Subp, Etype (Subp));
6522 -- If the call may be an indexed call, retrieve component type of
6523 -- resulting expression, and add possible interpretation.
6528 if Nkind (Call) = N_Function_Call
6529 and then Nkind (Parent (N)) = N_Indexed_Component
6530 and then Needs_One_Actual (Subp)
6532 if Is_Array_Type (Etype (Subp)) then
6533 Arr_Type := Etype (Subp);
6535 elsif Is_Access_Type (Etype (Subp))
6536 and then Is_Array_Type (Designated_Type (Etype (Subp)))
6538 Arr_Type := Designated_Type (Etype (Subp));
6542 if Present (Arr_Type) then
6544 -- Verify that the actuals (excluding the object) match the types
6552 Actual := Next (First_Actual (Call));
6553 Index := First_Index (Arr_Type);
6554 while Present (Actual) and then Present (Index) loop
6555 if not Has_Compatible_Type (Actual, Etype (Index)) then
6560 Next_Actual (Actual);
6566 and then Present (Arr_Type)
6568 Comp_Type := Component_Type (Arr_Type);
6572 if Present (Comp_Type)
6573 and then Etype (Subprog) /= Comp_Type
6575 Add_One_Interp (Subprog, Subp, Comp_Type);
6579 if Etype (Call) /= Any_Type then
6584 end Valid_Candidate;
6586 -------------------------------
6587 -- Complete_Object_Operation --
6588 -------------------------------
6590 procedure Complete_Object_Operation
6591 (Call_Node : Node_Id;
6592 Node_To_Replace : Node_Id)
6594 Control : constant Entity_Id := First_Formal (Entity (Subprog));
6595 Formal_Type : constant Entity_Id := Etype (Control);
6596 First_Actual : Node_Id;
6599 -- Place the name of the operation, with its interpretations,
6600 -- on the rewritten call.
6602 Set_Name (Call_Node, Subprog);
6604 First_Actual := First (Parameter_Associations (Call_Node));
6606 -- For cross-reference purposes, treat the new node as being in
6607 -- the source if the original one is.
6609 Set_Comes_From_Source (Subprog, Comes_From_Source (N));
6610 Set_Comes_From_Source (Call_Node, Comes_From_Source (N));
6612 if Nkind (N) = N_Selected_Component
6613 and then not Inside_A_Generic
6615 Set_Entity (Selector_Name (N), Entity (Subprog));
6618 -- If need be, rewrite first actual as an explicit dereference
6619 -- If the call is overloaded, the rewriting can only be done
6620 -- once the primitive operation is identified.
6622 if Is_Overloaded (Subprog) then
6624 -- The prefix itself may be overloaded, and its interpretations
6625 -- must be propagated to the new actual in the call.
6627 if Is_Overloaded (Obj) then
6628 Save_Interps (Obj, First_Actual);
6631 Rewrite (First_Actual, Obj);
6633 elsif not Is_Access_Type (Formal_Type)
6634 and then Is_Access_Type (Etype (Obj))
6636 Rewrite (First_Actual,
6637 Make_Explicit_Dereference (Sloc (Obj), Obj));
6638 Analyze (First_Actual);
6640 -- If we need to introduce an explicit dereference, verify that
6641 -- the resulting actual is compatible with the mode of the formal.
6643 if Ekind (First_Formal (Entity (Subprog))) /= E_In_Parameter
6644 and then Is_Access_Constant (Etype (Obj))
6647 ("expect variable in call to&", Prefix (N), Entity (Subprog));
6650 -- Conversely, if the formal is an access parameter and the object
6651 -- is not, replace the actual with a 'Access reference. Its analysis
6652 -- will check that the object is aliased.
6654 elsif Is_Access_Type (Formal_Type)
6655 and then not Is_Access_Type (Etype (Obj))
6657 -- A special case: A.all'access is illegal if A is an access to a
6658 -- constant and the context requires an access to a variable.
6660 if not Is_Access_Constant (Formal_Type) then
6661 if (Nkind (Obj) = N_Explicit_Dereference
6662 and then Is_Access_Constant (Etype (Prefix (Obj))))
6663 or else not Is_Variable (Obj)
6666 ("actual for& must be a variable", Obj, Control);
6670 Rewrite (First_Actual,
6671 Make_Attribute_Reference (Loc,
6672 Attribute_Name => Name_Access,
6673 Prefix => Relocate_Node (Obj)));
6675 if not Is_Aliased_View (Obj) then
6677 ("object in prefixed call to& must be aliased"
6678 & " (RM-2005 4.3.1 (13))",
6679 Prefix (First_Actual), Subprog);
6682 Analyze (First_Actual);
6685 if Is_Overloaded (Obj) then
6686 Save_Interps (Obj, First_Actual);
6689 Rewrite (First_Actual, Obj);
6692 Rewrite (Node_To_Replace, Call_Node);
6694 -- Propagate the interpretations collected in subprog to the new
6695 -- function call node, to be resolved from context.
6697 if Is_Overloaded (Subprog) then
6698 Save_Interps (Subprog, Node_To_Replace);
6701 Analyze (Node_To_Replace);
6703 -- If the operation has been rewritten into a call, which may get
6704 -- subsequently an explicit dereference, preserve the type on the
6705 -- original node (selected component or indexed component) for
6706 -- subsequent legality tests, e.g. Is_Variable. which examines
6707 -- the original node.
6709 if Nkind (Node_To_Replace) = N_Function_Call then
6711 (Original_Node (Node_To_Replace), Etype (Node_To_Replace));
6714 end Complete_Object_Operation;
6716 ----------------------
6717 -- Report_Ambiguity --
6718 ----------------------
6720 procedure Report_Ambiguity (Op : Entity_Id) is
6721 Access_Formal : constant Boolean :=
6722 Is_Access_Type (Etype (First_Formal (Op)));
6723 Access_Actual : constant Boolean :=
6724 Is_Access_Type (Etype (Prefix (N)));
6727 Error_Msg_Sloc := Sloc (Op);
6729 if Access_Formal and then not Access_Actual then
6730 if Nkind (Parent (Op)) = N_Full_Type_Declaration then
6732 ("\possible interpretation"
6733 & " (inherited, with implicit 'Access) #", N);
6736 ("\possible interpretation (with implicit 'Access) #", N);
6739 elsif not Access_Formal and then Access_Actual then
6740 if Nkind (Parent (Op)) = N_Full_Type_Declaration then
6742 ("\possible interpretation"
6743 & " ( inherited, with implicit dereference) #", N);
6746 ("\possible interpretation (with implicit dereference) #", N);
6750 if Nkind (Parent (Op)) = N_Full_Type_Declaration then
6751 Error_Msg_N ("\possible interpretation (inherited)#", N);
6753 Error_Msg_N -- CODEFIX
6754 ("\possible interpretation#", N);
6757 end Report_Ambiguity;
6759 --------------------------------
6760 -- Transform_Object_Operation --
6761 --------------------------------
6763 procedure Transform_Object_Operation
6764 (Call_Node : out Node_Id;
6765 Node_To_Replace : out Node_Id)
6767 Dummy : constant Node_Id := New_Copy (Obj);
6768 -- Placeholder used as a first parameter in the call, replaced
6769 -- eventually by the proper object.
6771 Parent_Node : constant Node_Id := Parent (N);
6777 -- Common case covering 1) Call to a procedure and 2) Call to a
6778 -- function that has some additional actuals.
6780 if Nkind_In (Parent_Node, N_Function_Call,
6781 N_Procedure_Call_Statement)
6783 -- N is a selected component node containing the name of the
6784 -- subprogram. If N is not the name of the parent node we must
6785 -- not replace the parent node by the new construct. This case
6786 -- occurs when N is a parameterless call to a subprogram that
6787 -- is an actual parameter of a call to another subprogram. For
6789 -- Some_Subprogram (..., Obj.Operation, ...)
6791 and then Name (Parent_Node) = N
6793 Node_To_Replace := Parent_Node;
6795 Actuals := Parameter_Associations (Parent_Node);
6797 if Present (Actuals) then
6798 Prepend (Dummy, Actuals);
6800 Actuals := New_List (Dummy);
6803 if Nkind (Parent_Node) = N_Procedure_Call_Statement then
6805 Make_Procedure_Call_Statement (Loc,
6806 Name => New_Copy (Subprog),
6807 Parameter_Associations => Actuals);
6811 Make_Function_Call (Loc,
6812 Name => New_Copy (Subprog),
6813 Parameter_Associations => Actuals);
6817 -- Before analysis, a function call appears as an indexed component
6818 -- if there are no named associations.
6820 elsif Nkind (Parent_Node) = N_Indexed_Component
6821 and then N = Prefix (Parent_Node)
6823 Node_To_Replace := Parent_Node;
6824 Actuals := Expressions (Parent_Node);
6826 Actual := First (Actuals);
6827 while Present (Actual) loop
6832 Prepend (Dummy, Actuals);
6835 Make_Function_Call (Loc,
6836 Name => New_Copy (Subprog),
6837 Parameter_Associations => Actuals);
6839 -- Parameterless call: Obj.F is rewritten as F (Obj)
6842 Node_To_Replace := N;
6845 Make_Function_Call (Loc,
6846 Name => New_Copy (Subprog),
6847 Parameter_Associations => New_List (Dummy));
6849 end Transform_Object_Operation;
6851 ------------------------------
6852 -- Try_Class_Wide_Operation --
6853 ------------------------------
6855 function Try_Class_Wide_Operation
6856 (Call_Node : Node_Id;
6857 Node_To_Replace : Node_Id) return Boolean
6859 Anc_Type : Entity_Id;
6860 Matching_Op : Entity_Id := Empty;
6863 procedure Traverse_Homonyms
6864 (Anc_Type : Entity_Id;
6865 Error : out Boolean);
6866 -- Traverse the homonym chain of the subprogram searching for those
6867 -- homonyms whose first formal has the Anc_Type's class-wide type,
6868 -- or an anonymous access type designating the class-wide type. If
6869 -- an ambiguity is detected, then Error is set to True.
6871 procedure Traverse_Interfaces
6872 (Anc_Type : Entity_Id;
6873 Error : out Boolean);
6874 -- Traverse the list of interfaces, if any, associated with Anc_Type
6875 -- and search for acceptable class-wide homonyms associated with each
6876 -- interface. If an ambiguity is detected, then Error is set to True.
6878 -----------------------
6879 -- Traverse_Homonyms --
6880 -----------------------
6882 procedure Traverse_Homonyms
6883 (Anc_Type : Entity_Id;
6884 Error : out Boolean)
6886 Cls_Type : Entity_Id;
6894 Cls_Type := Class_Wide_Type (Anc_Type);
6896 Hom := Current_Entity (Subprog);
6898 -- Find a non-hidden operation whose first parameter is of the
6899 -- class-wide type, a subtype thereof, or an anonymous access
6902 while Present (Hom) loop
6903 if Ekind_In (Hom, E_Procedure, E_Function)
6904 and then not Is_Hidden (Hom)
6905 and then Scope (Hom) = Scope (Anc_Type)
6906 and then Present (First_Formal (Hom))
6908 (Base_Type (Etype (First_Formal (Hom))) = Cls_Type
6910 (Is_Access_Type (Etype (First_Formal (Hom)))
6912 Ekind (Etype (First_Formal (Hom))) =
6913 E_Anonymous_Access_Type
6916 (Designated_Type (Etype (First_Formal (Hom)))) =
6919 Set_Etype (Call_Node, Any_Type);
6920 Set_Is_Overloaded (Call_Node, False);
6923 if No (Matching_Op) then
6924 Hom_Ref := New_Reference_To (Hom, Sloc (Subprog));
6925 Set_Etype (Call_Node, Any_Type);
6926 Set_Parent (Call_Node, Parent (Node_To_Replace));
6928 Set_Name (Call_Node, Hom_Ref);
6933 Report => Report_Error,
6935 Skip_First => True);
6938 Valid_Candidate (Success, Call_Node, Hom);
6944 Report => Report_Error,
6946 Skip_First => True);
6948 if Present (Valid_Candidate (Success, Call_Node, Hom))
6949 and then Nkind (Call_Node) /= N_Function_Call
6951 Error_Msg_NE ("ambiguous call to&", N, Hom);
6952 Report_Ambiguity (Matching_Op);
6953 Report_Ambiguity (Hom);
6960 Hom := Homonym (Hom);
6962 end Traverse_Homonyms;
6964 -------------------------
6965 -- Traverse_Interfaces --
6966 -------------------------
6968 procedure Traverse_Interfaces
6969 (Anc_Type : Entity_Id;
6970 Error : out Boolean)
6972 Intface_List : constant List_Id :=
6973 Abstract_Interface_List (Anc_Type);
6979 if Is_Non_Empty_List (Intface_List) then
6980 Intface := First (Intface_List);
6981 while Present (Intface) loop
6983 -- Look for acceptable class-wide homonyms associated with
6986 Traverse_Homonyms (Etype (Intface), Error);
6992 -- Continue the search by looking at each of the interface's
6993 -- associated interface ancestors.
6995 Traverse_Interfaces (Etype (Intface), Error);
7004 end Traverse_Interfaces;
7006 -- Start of processing for Try_Class_Wide_Operation
7009 -- Loop through ancestor types (including interfaces), traversing
7010 -- the homonym chain of the subprogram, trying out those homonyms
7011 -- whose first formal has the class-wide type of the ancestor, or
7012 -- an anonymous access type designating the class-wide type.
7014 Anc_Type := Obj_Type;
7016 -- Look for a match among homonyms associated with the ancestor
7018 Traverse_Homonyms (Anc_Type, Error);
7024 -- Continue the search for matches among homonyms associated with
7025 -- any interfaces implemented by the ancestor.
7027 Traverse_Interfaces (Anc_Type, Error);
7033 exit when Etype (Anc_Type) = Anc_Type;
7034 Anc_Type := Etype (Anc_Type);
7037 if Present (Matching_Op) then
7038 Set_Etype (Call_Node, Etype (Matching_Op));
7041 return Present (Matching_Op);
7042 end Try_Class_Wide_Operation;
7044 -----------------------------------
7045 -- Try_One_Prefix_Interpretation --
7046 -----------------------------------
7048 procedure Try_One_Prefix_Interpretation (T : Entity_Id) is
7052 if Is_Access_Type (Obj_Type) then
7053 Obj_Type := Designated_Type (Obj_Type);
7056 if Ekind (Obj_Type) = E_Private_Subtype then
7057 Obj_Type := Base_Type (Obj_Type);
7060 if Is_Class_Wide_Type (Obj_Type) then
7061 Obj_Type := Etype (Class_Wide_Type (Obj_Type));
7064 -- The type may have be obtained through a limited_with clause,
7065 -- in which case the primitive operations are available on its
7066 -- non-limited view. If still incomplete, retrieve full view.
7068 if Ekind (Obj_Type) = E_Incomplete_Type
7069 and then From_With_Type (Obj_Type)
7071 Obj_Type := Get_Full_View (Non_Limited_View (Obj_Type));
7074 -- If the object is not tagged, or the type is still an incomplete
7075 -- type, this is not a prefixed call.
7077 if not Is_Tagged_Type (Obj_Type)
7078 or else Is_Incomplete_Type (Obj_Type)
7083 if Try_Primitive_Operation
7084 (Call_Node => New_Call_Node,
7085 Node_To_Replace => Node_To_Replace)
7087 Try_Class_Wide_Operation
7088 (Call_Node => New_Call_Node,
7089 Node_To_Replace => Node_To_Replace)
7093 end Try_One_Prefix_Interpretation;
7095 -----------------------------
7096 -- Try_Primitive_Operation --
7097 -----------------------------
7099 function Try_Primitive_Operation
7100 (Call_Node : Node_Id;
7101 Node_To_Replace : Node_Id) return Boolean
7104 Prim_Op : Entity_Id;
7105 Matching_Op : Entity_Id := Empty;
7106 Prim_Op_Ref : Node_Id := Empty;
7108 Corr_Type : Entity_Id := Empty;
7109 -- If the prefix is a synchronized type, the controlling type of
7110 -- the primitive operation is the corresponding record type, else
7111 -- this is the object type itself.
7113 Success : Boolean := False;
7115 function Collect_Generic_Type_Ops (T : Entity_Id) return Elist_Id;
7116 -- For tagged types the candidate interpretations are found in
7117 -- the list of primitive operations of the type and its ancestors.
7118 -- For formal tagged types we have to find the operations declared
7119 -- in the same scope as the type (including in the generic formal
7120 -- part) because the type itself carries no primitive operations,
7121 -- except for formal derived types that inherit the operations of
7122 -- the parent and progenitors.
7123 -- If the context is a generic subprogram body, the generic formals
7124 -- are visible by name, but are not in the entity list of the
7125 -- subprogram because that list starts with the subprogram formals.
7126 -- We retrieve the candidate operations from the generic declaration.
7128 function Is_Private_Overriding (Op : Entity_Id) return Boolean;
7129 -- An operation that overrides an inherited operation in the private
7130 -- part of its package may be hidden, but if the inherited operation
7131 -- is visible a direct call to it will dispatch to the private one,
7132 -- which is therefore a valid candidate.
7134 function Valid_First_Argument_Of (Op : Entity_Id) return Boolean;
7135 -- Verify that the prefix, dereferenced if need be, is a valid
7136 -- controlling argument in a call to Op. The remaining actuals
7137 -- are checked in the subsequent call to Analyze_One_Call.
7139 ------------------------------
7140 -- Collect_Generic_Type_Ops --
7141 ------------------------------
7143 function Collect_Generic_Type_Ops (T : Entity_Id) return Elist_Id is
7144 Bas : constant Entity_Id := Base_Type (T);
7145 Candidates : constant Elist_Id := New_Elmt_List;
7149 procedure Check_Candidate;
7150 -- The operation is a candidate if its first parameter is a
7151 -- controlling operand of the desired type.
7153 -----------------------
7154 -- Check_Candidate; --
7155 -----------------------
7157 procedure Check_Candidate is
7159 Formal := First_Formal (Subp);
7162 and then Is_Controlling_Formal (Formal)
7164 (Base_Type (Etype (Formal)) = Bas
7166 (Is_Access_Type (Etype (Formal))
7167 and then Designated_Type (Etype (Formal)) = Bas))
7169 Append_Elmt (Subp, Candidates);
7171 end Check_Candidate;
7173 -- Start of processing for Collect_Generic_Type_Ops
7176 if Is_Derived_Type (T) then
7177 return Primitive_Operations (T);
7179 elsif Ekind_In (Scope (T), E_Procedure, E_Function) then
7181 -- Scan the list of generic formals to find subprograms
7182 -- that may have a first controlling formal of the type.
7184 if Nkind (Unit_Declaration_Node (Scope (T)))
7185 = N_Generic_Subprogram_Declaration
7192 First (Generic_Formal_Declarations
7193 (Unit_Declaration_Node (Scope (T))));
7194 while Present (Decl) loop
7195 if Nkind (Decl) in N_Formal_Subprogram_Declaration then
7196 Subp := Defining_Entity (Decl);
7207 -- Scan the list of entities declared in the same scope as
7208 -- the type. In general this will be an open scope, given that
7209 -- the call we are analyzing can only appear within a generic
7210 -- declaration or body (either the one that declares T, or a
7213 -- For a subtype representing a generic actual type, go to the
7216 if Is_Generic_Actual_Type (T) then
7217 Subp := First_Entity (Scope (Base_Type (T)));
7219 Subp := First_Entity (Scope (T));
7222 while Present (Subp) loop
7223 if Is_Overloadable (Subp) then
7232 end Collect_Generic_Type_Ops;
7234 ---------------------------
7235 -- Is_Private_Overriding --
7236 ---------------------------
7238 function Is_Private_Overriding (Op : Entity_Id) return Boolean is
7239 Visible_Op : constant Entity_Id := Homonym (Op);
7242 return Present (Visible_Op)
7243 and then Scope (Op) = Scope (Visible_Op)
7244 and then not Comes_From_Source (Visible_Op)
7245 and then Alias (Visible_Op) = Op
7246 and then not Is_Hidden (Visible_Op);
7247 end Is_Private_Overriding;
7249 -----------------------------
7250 -- Valid_First_Argument_Of --
7251 -----------------------------
7253 function Valid_First_Argument_Of (Op : Entity_Id) return Boolean is
7254 Typ : Entity_Id := Etype (First_Formal (Op));
7257 if Is_Concurrent_Type (Typ)
7258 and then Present (Corresponding_Record_Type (Typ))
7260 Typ := Corresponding_Record_Type (Typ);
7263 -- Simple case. Object may be a subtype of the tagged type or
7264 -- may be the corresponding record of a synchronized type.
7266 return Obj_Type = Typ
7267 or else Base_Type (Obj_Type) = Typ
7268 or else Corr_Type = Typ
7270 -- Prefix can be dereferenced
7273 (Is_Access_Type (Corr_Type)
7274 and then Designated_Type (Corr_Type) = Typ)
7276 -- Formal is an access parameter, for which the object
7277 -- can provide an access.
7280 (Ekind (Typ) = E_Anonymous_Access_Type
7282 Base_Type (Designated_Type (Typ)) = Base_Type (Corr_Type));
7283 end Valid_First_Argument_Of;
7285 -- Start of processing for Try_Primitive_Operation
7288 -- Look for subprograms in the list of primitive operations. The name
7289 -- must be identical, and the kind of call indicates the expected
7290 -- kind of operation (function or procedure). If the type is a
7291 -- (tagged) synchronized type, the primitive ops are attached to the
7292 -- corresponding record (base) type.
7294 if Is_Concurrent_Type (Obj_Type) then
7295 if Present (Corresponding_Record_Type (Obj_Type)) then
7296 Corr_Type := Base_Type (Corresponding_Record_Type (Obj_Type));
7297 Elmt := First_Elmt (Primitive_Operations (Corr_Type));
7299 Corr_Type := Obj_Type;
7300 Elmt := First_Elmt (Collect_Generic_Type_Ops (Obj_Type));
7303 elsif not Is_Generic_Type (Obj_Type) then
7304 Corr_Type := Obj_Type;
7305 Elmt := First_Elmt (Primitive_Operations (Obj_Type));
7308 Corr_Type := Obj_Type;
7309 Elmt := First_Elmt (Collect_Generic_Type_Ops (Obj_Type));
7312 while Present (Elmt) loop
7313 Prim_Op := Node (Elmt);
7315 if Chars (Prim_Op) = Chars (Subprog)
7316 and then Present (First_Formal (Prim_Op))
7317 and then Valid_First_Argument_Of (Prim_Op)
7319 (Nkind (Call_Node) = N_Function_Call)
7320 = (Ekind (Prim_Op) = E_Function)
7322 -- Ada 2005 (AI-251): If this primitive operation corresponds
7323 -- with an immediate ancestor interface there is no need to add
7324 -- it to the list of interpretations; the corresponding aliased
7325 -- primitive is also in this list of primitive operations and
7326 -- will be used instead.
7328 if (Present (Interface_Alias (Prim_Op))
7329 and then Is_Ancestor (Find_Dispatching_Type
7330 (Alias (Prim_Op)), Corr_Type))
7332 -- Do not consider hidden primitives unless the type is in an
7333 -- open scope or we are within an instance, where visibility
7334 -- is known to be correct, or else if this is an overriding
7335 -- operation in the private part for an inherited operation.
7337 or else (Is_Hidden (Prim_Op)
7338 and then not Is_Immediately_Visible (Obj_Type)
7339 and then not In_Instance
7340 and then not Is_Private_Overriding (Prim_Op))
7345 Set_Etype (Call_Node, Any_Type);
7346 Set_Is_Overloaded (Call_Node, False);
7348 if No (Matching_Op) then
7349 Prim_Op_Ref := New_Reference_To (Prim_Op, Sloc (Subprog));
7350 Candidate := Prim_Op;
7352 Set_Parent (Call_Node, Parent (Node_To_Replace));
7354 Set_Name (Call_Node, Prim_Op_Ref);
7360 Report => Report_Error,
7362 Skip_First => True);
7364 Matching_Op := Valid_Candidate (Success, Call_Node, Prim_Op);
7366 -- More than one interpretation, collect for subsequent
7367 -- disambiguation. If this is a procedure call and there
7368 -- is another match, report ambiguity now.
7374 Report => Report_Error,
7376 Skip_First => True);
7378 if Present (Valid_Candidate (Success, Call_Node, Prim_Op))
7379 and then Nkind (Call_Node) /= N_Function_Call
7381 Error_Msg_NE ("ambiguous call to&", N, Prim_Op);
7382 Report_Ambiguity (Matching_Op);
7383 Report_Ambiguity (Prim_Op);
7393 if Present (Matching_Op) then
7394 Set_Etype (Call_Node, Etype (Matching_Op));
7397 return Present (Matching_Op);
7398 end Try_Primitive_Operation;
7400 -- Start of processing for Try_Object_Operation
7403 Analyze_Expression (Obj);
7405 -- Analyze the actuals if node is known to be a subprogram call
7407 if Is_Subprg_Call and then N = Name (Parent (N)) then
7408 Actual := First (Parameter_Associations (Parent (N)));
7409 while Present (Actual) loop
7410 Analyze_Expression (Actual);
7415 -- Build a subprogram call node, using a copy of Obj as its first
7416 -- actual. This is a placeholder, to be replaced by an explicit
7417 -- dereference when needed.
7419 Transform_Object_Operation
7420 (Call_Node => New_Call_Node,
7421 Node_To_Replace => Node_To_Replace);
7423 Set_Etype (New_Call_Node, Any_Type);
7424 Set_Etype (Subprog, Any_Type);
7425 Set_Parent (New_Call_Node, Parent (Node_To_Replace));
7427 if not Is_Overloaded (Obj) then
7428 Try_One_Prefix_Interpretation (Obj_Type);
7435 Get_First_Interp (Obj, I, It);
7436 while Present (It.Nam) loop
7437 Try_One_Prefix_Interpretation (It.Typ);
7438 Get_Next_Interp (I, It);
7443 if Etype (New_Call_Node) /= Any_Type then
7444 Complete_Object_Operation
7445 (Call_Node => New_Call_Node,
7446 Node_To_Replace => Node_To_Replace);
7449 elsif Present (Candidate) then
7451 -- The argument list is not type correct. Re-analyze with error
7452 -- reporting enabled, and use one of the possible candidates.
7453 -- In All_Errors_Mode, re-analyze all failed interpretations.
7455 if All_Errors_Mode then
7456 Report_Error := True;
7457 if Try_Primitive_Operation
7458 (Call_Node => New_Call_Node,
7459 Node_To_Replace => Node_To_Replace)
7462 Try_Class_Wide_Operation
7463 (Call_Node => New_Call_Node,
7464 Node_To_Replace => Node_To_Replace)
7471 (N => New_Call_Node,
7475 Skip_First => True);
7478 -- No need for further errors
7483 -- There was no candidate operation, so report it as an error
7484 -- in the caller: Analyze_Selected_Component.
7488 end Try_Object_Operation;
7494 procedure wpo (T : Entity_Id) is
7499 if not Is_Tagged_Type (T) then
7503 E := First_Elmt (Primitive_Operations (Base_Type (T)));
7504 while Present (E) loop
7506 Write_Int (Int (Op));
7507 Write_Str (" === ");
7508 Write_Name (Chars (Op));
7510 Write_Name (Chars (Scope (Op)));