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 Mark_Non_ALFA_Subprogram;
1524 Check_SPARK_Restriction ("conditional expression is not allowed", N);
1526 Else_Expr := Next (Then_Expr);
1528 if Comes_From_Source (N) then
1529 Check_Compiler_Unit (N);
1532 Analyze_Expression (Condition);
1533 Analyze_Expression (Then_Expr);
1535 if Present (Else_Expr) then
1536 Analyze_Expression (Else_Expr);
1539 -- If then expression not overloaded, then that decides the type
1541 if not Is_Overloaded (Then_Expr) then
1542 Set_Etype (N, Etype (Then_Expr));
1544 -- Case where then expression is overloaded
1552 Set_Etype (N, Any_Type);
1554 -- Shouldn't the following statement be down in the ELSE of the
1555 -- following loop? ???
1557 Get_First_Interp (Then_Expr, I, It);
1559 -- if no Else_Expression the conditional must be boolean
1561 if No (Else_Expr) then
1562 Set_Etype (N, Standard_Boolean);
1564 -- Else_Expression Present. For each possible intepretation of
1565 -- the Then_Expression, add it only if the Else_Expression has
1566 -- a compatible type.
1569 while Present (It.Nam) loop
1570 if Has_Compatible_Type (Else_Expr, It.Typ) then
1571 Add_One_Interp (N, It.Typ, It.Typ);
1574 Get_Next_Interp (I, It);
1579 end Analyze_Conditional_Expression;
1581 -------------------------
1582 -- Analyze_Equality_Op --
1583 -------------------------
1585 procedure Analyze_Equality_Op (N : Node_Id) is
1586 Loc : constant Source_Ptr := Sloc (N);
1587 L : constant Node_Id := Left_Opnd (N);
1588 R : constant Node_Id := Right_Opnd (N);
1592 Set_Etype (N, Any_Type);
1593 Candidate_Type := Empty;
1595 Analyze_Expression (L);
1596 Analyze_Expression (R);
1598 -- If the entity is set, the node is a generic instance with a non-local
1599 -- reference to the predefined operator or to a user-defined function.
1600 -- It can also be an inequality that is expanded into the negation of a
1601 -- call to a user-defined equality operator.
1603 -- For the predefined case, the result is Boolean, regardless of the
1604 -- type of the operands. The operands may even be limited, if they are
1605 -- generic actuals. If they are overloaded, label the left argument with
1606 -- the common type that must be present, or with the type of the formal
1607 -- of the user-defined function.
1609 if Present (Entity (N)) then
1610 Op_Id := Entity (N);
1612 if Ekind (Op_Id) = E_Operator then
1613 Add_One_Interp (N, Op_Id, Standard_Boolean);
1615 Add_One_Interp (N, Op_Id, Etype (Op_Id));
1618 if Is_Overloaded (L) then
1619 if Ekind (Op_Id) = E_Operator then
1620 Set_Etype (L, Intersect_Types (L, R));
1622 Set_Etype (L, Etype (First_Formal (Op_Id)));
1627 Op_Id := Get_Name_Entity_Id (Chars (N));
1628 while Present (Op_Id) loop
1629 if Ekind (Op_Id) = E_Operator then
1630 Find_Equality_Types (L, R, Op_Id, N);
1632 Analyze_User_Defined_Binary_Op (N, Op_Id);
1635 Op_Id := Homonym (Op_Id);
1639 -- If there was no match, and the operator is inequality, this may
1640 -- be a case where inequality has not been made explicit, as for
1641 -- tagged types. Analyze the node as the negation of an equality
1642 -- operation. This cannot be done earlier, because before analysis
1643 -- we cannot rule out the presence of an explicit inequality.
1645 if Etype (N) = Any_Type
1646 and then Nkind (N) = N_Op_Ne
1648 Op_Id := Get_Name_Entity_Id (Name_Op_Eq);
1649 while Present (Op_Id) loop
1650 if Ekind (Op_Id) = E_Operator then
1651 Find_Equality_Types (L, R, Op_Id, N);
1653 Analyze_User_Defined_Binary_Op (N, Op_Id);
1656 Op_Id := Homonym (Op_Id);
1659 if Etype (N) /= Any_Type then
1660 Op_Id := Entity (N);
1666 Left_Opnd => Left_Opnd (N),
1667 Right_Opnd => Right_Opnd (N))));
1669 Set_Entity (Right_Opnd (N), Op_Id);
1675 end Analyze_Equality_Op;
1677 ----------------------------------
1678 -- Analyze_Explicit_Dereference --
1679 ----------------------------------
1681 procedure Analyze_Explicit_Dereference (N : Node_Id) is
1682 Loc : constant Source_Ptr := Sloc (N);
1683 P : constant Node_Id := Prefix (N);
1689 function Is_Function_Type return Boolean;
1690 -- Check whether node may be interpreted as an implicit function call
1692 ----------------------
1693 -- Is_Function_Type --
1694 ----------------------
1696 function Is_Function_Type return Boolean is
1701 if not Is_Overloaded (N) then
1702 return Ekind (Base_Type (Etype (N))) = E_Subprogram_Type
1703 and then Etype (Base_Type (Etype (N))) /= Standard_Void_Type;
1706 Get_First_Interp (N, I, It);
1707 while Present (It.Nam) loop
1708 if Ekind (Base_Type (It.Typ)) /= E_Subprogram_Type
1709 or else Etype (Base_Type (It.Typ)) = Standard_Void_Type
1714 Get_Next_Interp (I, It);
1719 end Is_Function_Type;
1721 -- Start of processing for Analyze_Explicit_Dereference
1724 Mark_Non_ALFA_Subprogram;
1725 Check_SPARK_Restriction ("explicit dereference is not allowed", N);
1728 Set_Etype (N, Any_Type);
1730 -- Test for remote access to subprogram type, and if so return
1731 -- after rewriting the original tree.
1733 if Remote_AST_E_Dereference (P) then
1737 -- Normal processing for other than remote access to subprogram type
1739 if not Is_Overloaded (P) then
1740 if Is_Access_Type (Etype (P)) then
1742 -- Set the Etype. We need to go through Is_For_Access_Subtypes to
1743 -- avoid other problems caused by the Private_Subtype and it is
1744 -- safe to go to the Base_Type because this is the same as
1745 -- converting the access value to its Base_Type.
1748 DT : Entity_Id := Designated_Type (Etype (P));
1751 if Ekind (DT) = E_Private_Subtype
1752 and then Is_For_Access_Subtype (DT)
1754 DT := Base_Type (DT);
1757 -- An explicit dereference is a legal occurrence of an
1758 -- incomplete type imported through a limited_with clause,
1759 -- if the full view is visible.
1761 if From_With_Type (DT)
1762 and then not From_With_Type (Scope (DT))
1764 (Is_Immediately_Visible (Scope (DT))
1766 (Is_Child_Unit (Scope (DT))
1767 and then Is_Visible_Child_Unit (Scope (DT))))
1769 Set_Etype (N, Available_View (DT));
1776 elsif Etype (P) /= Any_Type then
1777 Error_Msg_N ("prefix of dereference must be an access type", N);
1782 Get_First_Interp (P, I, It);
1783 while Present (It.Nam) loop
1786 if Is_Access_Type (T) then
1787 Add_One_Interp (N, Designated_Type (T), Designated_Type (T));
1790 Get_Next_Interp (I, It);
1793 -- Error if no interpretation of the prefix has an access type
1795 if Etype (N) = Any_Type then
1797 ("access type required in prefix of explicit dereference", P);
1798 Set_Etype (N, Any_Type);
1804 and then Nkind (Parent (N)) /= N_Indexed_Component
1806 and then (Nkind (Parent (N)) /= N_Function_Call
1807 or else N /= Name (Parent (N)))
1809 and then (Nkind (Parent (N)) /= N_Procedure_Call_Statement
1810 or else N /= Name (Parent (N)))
1812 and then Nkind (Parent (N)) /= N_Subprogram_Renaming_Declaration
1813 and then (Nkind (Parent (N)) /= N_Attribute_Reference
1815 (Attribute_Name (Parent (N)) /= Name_Address
1817 Attribute_Name (Parent (N)) /= Name_Access))
1819 -- Name is a function call with no actuals, in a context that
1820 -- requires deproceduring (including as an actual in an enclosing
1821 -- function or procedure call). There are some pathological cases
1822 -- where the prefix might include functions that return access to
1823 -- subprograms and others that return a regular type. Disambiguation
1824 -- of those has to take place in Resolve.
1827 Make_Function_Call (Loc,
1828 Name => Make_Explicit_Dereference (Loc, P),
1829 Parameter_Associations => New_List);
1831 -- If the prefix is overloaded, remove operations that have formals,
1832 -- we know that this is a parameterless call.
1834 if Is_Overloaded (P) then
1835 Get_First_Interp (P, I, It);
1836 while Present (It.Nam) loop
1839 if No (First_Formal (Base_Type (Designated_Type (T)))) then
1845 Get_Next_Interp (I, It);
1852 elsif not Is_Function_Type
1853 and then Is_Overloaded (N)
1855 -- The prefix may include access to subprograms and other access
1856 -- types. If the context selects the interpretation that is a
1857 -- function call (not a procedure call) we cannot rewrite the node
1858 -- yet, but we include the result of the call interpretation.
1860 Get_First_Interp (N, I, It);
1861 while Present (It.Nam) loop
1862 if Ekind (Base_Type (It.Typ)) = E_Subprogram_Type
1863 and then Etype (Base_Type (It.Typ)) /= Standard_Void_Type
1864 and then Nkind (Parent (N)) /= N_Procedure_Call_Statement
1866 Add_One_Interp (N, Etype (It.Typ), Etype (It.Typ));
1869 Get_Next_Interp (I, It);
1873 -- A value of remote access-to-class-wide must not be dereferenced
1876 Validate_Remote_Access_To_Class_Wide_Type (N);
1877 end Analyze_Explicit_Dereference;
1879 ------------------------
1880 -- Analyze_Expression --
1881 ------------------------
1883 procedure Analyze_Expression (N : Node_Id) is
1886 Check_Parameterless_Call (N);
1887 end Analyze_Expression;
1889 -------------------------------------
1890 -- Analyze_Expression_With_Actions --
1891 -------------------------------------
1893 procedure Analyze_Expression_With_Actions (N : Node_Id) is
1897 A := First (Actions (N));
1904 Analyze_Expression (Expression (N));
1905 Set_Etype (N, Etype (Expression (N)));
1906 end Analyze_Expression_With_Actions;
1908 ------------------------------------
1909 -- Analyze_Indexed_Component_Form --
1910 ------------------------------------
1912 procedure Analyze_Indexed_Component_Form (N : Node_Id) is
1913 P : constant Node_Id := Prefix (N);
1914 Exprs : constant List_Id := Expressions (N);
1920 procedure Process_Function_Call;
1921 -- Prefix in indexed component form is an overloadable entity,
1922 -- so the node is a function call. Reformat it as such.
1924 procedure Process_Indexed_Component;
1925 -- Prefix in indexed component form is actually an indexed component.
1926 -- This routine processes it, knowing that the prefix is already
1929 procedure Process_Indexed_Component_Or_Slice;
1930 -- An indexed component with a single index may designate a slice if
1931 -- the index is a subtype mark. This routine disambiguates these two
1932 -- cases by resolving the prefix to see if it is a subtype mark.
1934 procedure Process_Overloaded_Indexed_Component;
1935 -- If the prefix of an indexed component is overloaded, the proper
1936 -- interpretation is selected by the index types and the context.
1938 ---------------------------
1939 -- Process_Function_Call --
1940 ---------------------------
1942 procedure Process_Function_Call is
1946 Change_Node (N, N_Function_Call);
1948 Set_Parameter_Associations (N, Exprs);
1950 -- Analyze actuals prior to analyzing the call itself
1952 Actual := First (Parameter_Associations (N));
1953 while Present (Actual) loop
1955 Check_Parameterless_Call (Actual);
1957 -- Move to next actual. Note that we use Next, not Next_Actual
1958 -- here. The reason for this is a bit subtle. If a function call
1959 -- includes named associations, the parser recognizes the node as
1960 -- a call, and it is analyzed as such. If all associations are
1961 -- positional, the parser builds an indexed_component node, and
1962 -- it is only after analysis of the prefix that the construct
1963 -- is recognized as a call, in which case Process_Function_Call
1964 -- rewrites the node and analyzes the actuals. If the list of
1965 -- actuals is malformed, the parser may leave the node as an
1966 -- indexed component (despite the presence of named associations).
1967 -- The iterator Next_Actual is equivalent to Next if the list is
1968 -- positional, but follows the normalized chain of actuals when
1969 -- named associations are present. In this case normalization has
1970 -- not taken place, and actuals remain unanalyzed, which leads to
1971 -- subsequent crashes or loops if there is an attempt to continue
1972 -- analysis of the program.
1978 end Process_Function_Call;
1980 -------------------------------
1981 -- Process_Indexed_Component --
1982 -------------------------------
1984 procedure Process_Indexed_Component is
1986 Array_Type : Entity_Id;
1988 Pent : Entity_Id := Empty;
1991 Exp := First (Exprs);
1993 if Is_Overloaded (P) then
1994 Process_Overloaded_Indexed_Component;
1997 Array_Type := Etype (P);
1999 if Is_Entity_Name (P) then
2001 elsif Nkind (P) = N_Selected_Component
2002 and then Is_Entity_Name (Selector_Name (P))
2004 Pent := Entity (Selector_Name (P));
2007 -- Prefix must be appropriate for an array type, taking into
2008 -- account a possible implicit dereference.
2010 if Is_Access_Type (Array_Type) then
2011 Error_Msg_NW (Warn_On_Dereference, "?implicit dereference", N);
2012 Array_Type := Process_Implicit_Dereference_Prefix (Pent, P);
2015 if Is_Array_Type (Array_Type) then
2018 elsif Present (Pent) and then Ekind (Pent) = E_Entry_Family then
2020 Set_Etype (N, Any_Type);
2022 if not Has_Compatible_Type
2023 (Exp, Entry_Index_Type (Pent))
2025 Error_Msg_N ("invalid index type in entry name", N);
2027 elsif Present (Next (Exp)) then
2028 Error_Msg_N ("too many subscripts in entry reference", N);
2031 Set_Etype (N, Etype (P));
2036 elsif Is_Record_Type (Array_Type)
2037 and then Remote_AST_I_Dereference (P)
2041 elsif Array_Type = Any_Type then
2042 Set_Etype (N, Any_Type);
2044 -- In most cases the analysis of the prefix will have emitted
2045 -- an error already, but if the prefix may be interpreted as a
2046 -- call in prefixed notation, the report is left to the caller.
2047 -- To prevent cascaded errors, report only if no previous ones.
2049 if Serious_Errors_Detected = 0 then
2050 Error_Msg_N ("invalid prefix in indexed component", P);
2052 if Nkind (P) = N_Expanded_Name then
2053 Error_Msg_NE ("\& is not visible", P, Selector_Name (P));
2059 -- Here we definitely have a bad indexing
2062 if Nkind (Parent (N)) = N_Requeue_Statement
2063 and then Present (Pent) and then Ekind (Pent) = E_Entry
2066 ("REQUEUE does not permit parameters", First (Exprs));
2068 elsif Is_Entity_Name (P)
2069 and then Etype (P) = Standard_Void_Type
2071 Error_Msg_NE ("incorrect use of&", P, Entity (P));
2074 Error_Msg_N ("array type required in indexed component", P);
2077 Set_Etype (N, Any_Type);
2081 Index := First_Index (Array_Type);
2082 while Present (Index) and then Present (Exp) loop
2083 if not Has_Compatible_Type (Exp, Etype (Index)) then
2084 Wrong_Type (Exp, Etype (Index));
2085 Set_Etype (N, Any_Type);
2093 Set_Etype (N, Component_Type (Array_Type));
2095 if Present (Index) then
2097 ("too few subscripts in array reference", First (Exprs));
2099 elsif Present (Exp) then
2100 Error_Msg_N ("too many subscripts in array reference", Exp);
2103 end Process_Indexed_Component;
2105 ----------------------------------------
2106 -- Process_Indexed_Component_Or_Slice --
2107 ----------------------------------------
2109 procedure Process_Indexed_Component_Or_Slice is
2111 Exp := First (Exprs);
2112 while Present (Exp) loop
2113 Analyze_Expression (Exp);
2117 Exp := First (Exprs);
2119 -- If one index is present, and it is a subtype name, then the
2120 -- node denotes a slice (note that the case of an explicit range
2121 -- for a slice was already built as an N_Slice node in the first
2122 -- place, so that case is not handled here).
2124 -- We use a replace rather than a rewrite here because this is one
2125 -- of the cases in which the tree built by the parser is plain wrong.
2128 and then Is_Entity_Name (Exp)
2129 and then Is_Type (Entity (Exp))
2132 Make_Slice (Sloc (N),
2134 Discrete_Range => New_Copy (Exp)));
2137 -- Otherwise (more than one index present, or single index is not
2138 -- a subtype name), then we have the indexed component case.
2141 Process_Indexed_Component;
2143 end Process_Indexed_Component_Or_Slice;
2145 ------------------------------------------
2146 -- Process_Overloaded_Indexed_Component --
2147 ------------------------------------------
2149 procedure Process_Overloaded_Indexed_Component is
2158 Set_Etype (N, Any_Type);
2160 Get_First_Interp (P, I, It);
2161 while Present (It.Nam) loop
2164 if Is_Access_Type (Typ) then
2165 Typ := Designated_Type (Typ);
2166 Error_Msg_NW (Warn_On_Dereference, "?implicit dereference", N);
2169 if Is_Array_Type (Typ) then
2171 -- Got a candidate: verify that index types are compatible
2173 Index := First_Index (Typ);
2175 Exp := First (Exprs);
2176 while Present (Index) and then Present (Exp) loop
2177 if Has_Compatible_Type (Exp, Etype (Index)) then
2189 if Found and then No (Index) and then No (Exp) then
2191 Etype (Component_Type (Typ)),
2192 Etype (Component_Type (Typ)));
2196 Get_Next_Interp (I, It);
2199 if Etype (N) = Any_Type then
2200 Error_Msg_N ("no legal interpretation for indexed component", N);
2201 Set_Is_Overloaded (N, False);
2205 end Process_Overloaded_Indexed_Component;
2207 -- Start of processing for Analyze_Indexed_Component_Form
2210 -- Get name of array, function or type
2214 if Nkind_In (N, N_Function_Call, N_Procedure_Call_Statement) then
2216 -- If P is an explicit dereference whose prefix is of a
2217 -- remote access-to-subprogram type, then N has already
2218 -- been rewritten as a subprogram call and analyzed.
2223 pragma Assert (Nkind (N) = N_Indexed_Component);
2225 P_T := Base_Type (Etype (P));
2227 if Is_Entity_Name (P) and then Present (Entity (P)) then
2230 if Is_Type (U_N) then
2232 -- Reformat node as a type conversion
2234 E := Remove_Head (Exprs);
2236 if Present (First (Exprs)) then
2238 ("argument of type conversion must be single expression", N);
2241 Change_Node (N, N_Type_Conversion);
2242 Set_Subtype_Mark (N, P);
2244 Set_Expression (N, E);
2246 -- After changing the node, call for the specific Analysis
2247 -- routine directly, to avoid a double call to the expander.
2249 Analyze_Type_Conversion (N);
2253 if Is_Overloadable (U_N) then
2254 Process_Function_Call;
2256 elsif Ekind (Etype (P)) = E_Subprogram_Type
2257 or else (Is_Access_Type (Etype (P))
2259 Ekind (Designated_Type (Etype (P))) =
2262 -- Call to access_to-subprogram with possible implicit dereference
2264 Process_Function_Call;
2266 elsif Is_Generic_Subprogram (U_N) then
2268 -- A common beginner's (or C++ templates fan) error
2270 Error_Msg_N ("generic subprogram cannot be called", N);
2271 Set_Etype (N, Any_Type);
2275 Process_Indexed_Component_Or_Slice;
2278 -- If not an entity name, prefix is an expression that may denote
2279 -- an array or an access-to-subprogram.
2282 if Ekind (P_T) = E_Subprogram_Type
2283 or else (Is_Access_Type (P_T)
2285 Ekind (Designated_Type (P_T)) = E_Subprogram_Type)
2287 Process_Function_Call;
2289 elsif Nkind (P) = N_Selected_Component
2290 and then Is_Overloadable (Entity (Selector_Name (P)))
2292 Process_Function_Call;
2295 -- Indexed component, slice, or a call to a member of a family
2296 -- entry, which will be converted to an entry call later.
2298 Process_Indexed_Component_Or_Slice;
2301 end Analyze_Indexed_Component_Form;
2303 ------------------------
2304 -- Analyze_Logical_Op --
2305 ------------------------
2307 procedure Analyze_Logical_Op (N : Node_Id) is
2308 L : constant Node_Id := Left_Opnd (N);
2309 R : constant Node_Id := Right_Opnd (N);
2310 Op_Id : Entity_Id := Entity (N);
2313 Set_Etype (N, Any_Type);
2314 Candidate_Type := Empty;
2316 Analyze_Expression (L);
2317 Analyze_Expression (R);
2319 if Present (Op_Id) then
2321 if Ekind (Op_Id) = E_Operator then
2322 Find_Boolean_Types (L, R, Op_Id, N);
2324 Add_One_Interp (N, Op_Id, Etype (Op_Id));
2328 Op_Id := Get_Name_Entity_Id (Chars (N));
2329 while Present (Op_Id) loop
2330 if Ekind (Op_Id) = E_Operator then
2331 Find_Boolean_Types (L, R, Op_Id, N);
2333 Analyze_User_Defined_Binary_Op (N, Op_Id);
2336 Op_Id := Homonym (Op_Id);
2341 end Analyze_Logical_Op;
2343 ---------------------------
2344 -- Analyze_Membership_Op --
2345 ---------------------------
2347 procedure Analyze_Membership_Op (N : Node_Id) is
2348 Loc : constant Source_Ptr := Sloc (N);
2349 L : constant Node_Id := Left_Opnd (N);
2350 R : constant Node_Id := Right_Opnd (N);
2352 Index : Interp_Index;
2354 Found : Boolean := False;
2358 procedure Try_One_Interp (T1 : Entity_Id);
2359 -- Routine to try one proposed interpretation. Note that the context
2360 -- of the operation plays no role in resolving the arguments, so that
2361 -- if there is more than one interpretation of the operands that is
2362 -- compatible with a membership test, the operation is ambiguous.
2364 --------------------
2365 -- Try_One_Interp --
2366 --------------------
2368 procedure Try_One_Interp (T1 : Entity_Id) is
2370 if Has_Compatible_Type (R, T1) then
2372 and then Base_Type (T1) /= Base_Type (T_F)
2374 It := Disambiguate (L, I_F, Index, Any_Type);
2376 if It = No_Interp then
2377 Ambiguous_Operands (N);
2378 Set_Etype (L, Any_Type);
2395 procedure Analyze_Set_Membership;
2396 -- If a set of alternatives is present, analyze each and find the
2397 -- common type to which they must all resolve.
2399 ----------------------------
2400 -- Analyze_Set_Membership --
2401 ----------------------------
2403 procedure Analyze_Set_Membership is
2405 Index : Interp_Index;
2407 Candidate_Interps : Node_Id;
2408 Common_Type : Entity_Id := Empty;
2412 Candidate_Interps := L;
2414 if not Is_Overloaded (L) then
2415 Common_Type := Etype (L);
2417 Alt := First (Alternatives (N));
2418 while Present (Alt) loop
2421 if not Has_Compatible_Type (Alt, Common_Type) then
2422 Wrong_Type (Alt, Common_Type);
2429 Alt := First (Alternatives (N));
2430 while Present (Alt) loop
2432 if not Is_Overloaded (Alt) then
2433 Common_Type := Etype (Alt);
2436 Get_First_Interp (Alt, Index, It);
2437 while Present (It.Typ) loop
2439 Has_Compatible_Type (Candidate_Interps, It.Typ)
2441 Remove_Interp (Index);
2444 Get_Next_Interp (Index, It);
2447 Get_First_Interp (Alt, Index, It);
2450 Error_Msg_N ("alternative has no legal type", Alt);
2454 -- If alternative is not overloaded, we have a unique type
2457 Set_Etype (Alt, It.Typ);
2458 Get_Next_Interp (Index, It);
2461 Set_Is_Overloaded (Alt, False);
2462 Common_Type := Etype (Alt);
2465 Candidate_Interps := Alt;
2472 Set_Etype (N, Standard_Boolean);
2474 if Present (Common_Type) then
2475 Set_Etype (L, Common_Type);
2476 Set_Is_Overloaded (L, False);
2479 Error_Msg_N ("cannot resolve membership operation", N);
2481 end Analyze_Set_Membership;
2483 -- Start of processing for Analyze_Membership_Op
2486 Mark_Non_ALFA_Subprogram;
2488 Analyze_Expression (L);
2491 and then Ada_Version >= Ada_2012
2493 Analyze_Set_Membership;
2497 if Nkind (R) = N_Range
2498 or else (Nkind (R) = N_Attribute_Reference
2499 and then Attribute_Name (R) = Name_Range)
2503 if not Is_Overloaded (L) then
2504 Try_One_Interp (Etype (L));
2507 Get_First_Interp (L, Index, It);
2508 while Present (It.Typ) loop
2509 Try_One_Interp (It.Typ);
2510 Get_Next_Interp (Index, It);
2514 -- If not a range, it can be a subtype mark, or else it is a degenerate
2515 -- membership test with a singleton value, i.e. a test for equality,
2516 -- if the types are compatible.
2520 if Is_Entity_Name (R)
2521 and then Is_Type (Entity (R))
2524 Check_Fully_Declared (Entity (R), R);
2526 elsif Ada_Version >= Ada_2012
2527 and then Has_Compatible_Type (R, Etype (L))
2529 if Nkind (N) = N_In then
2545 -- In all versions of the language, if we reach this point there
2546 -- is a previous error that will be diagnosed below.
2552 -- Compatibility between expression and subtype mark or range is
2553 -- checked during resolution. The result of the operation is Boolean
2556 Set_Etype (N, Standard_Boolean);
2558 if Comes_From_Source (N)
2559 and then Present (Right_Opnd (N))
2560 and then Is_CPP_Class (Etype (Etype (Right_Opnd (N))))
2562 Error_Msg_N ("membership test not applicable to cpp-class types", N);
2564 end Analyze_Membership_Op;
2566 ----------------------
2567 -- Analyze_Negation --
2568 ----------------------
2570 procedure Analyze_Negation (N : Node_Id) is
2571 R : constant Node_Id := Right_Opnd (N);
2572 Op_Id : Entity_Id := Entity (N);
2575 Set_Etype (N, Any_Type);
2576 Candidate_Type := Empty;
2578 Analyze_Expression (R);
2580 if Present (Op_Id) then
2581 if Ekind (Op_Id) = E_Operator then
2582 Find_Negation_Types (R, Op_Id, N);
2584 Add_One_Interp (N, Op_Id, Etype (Op_Id));
2588 Op_Id := Get_Name_Entity_Id (Chars (N));
2589 while Present (Op_Id) loop
2590 if Ekind (Op_Id) = E_Operator then
2591 Find_Negation_Types (R, Op_Id, N);
2593 Analyze_User_Defined_Unary_Op (N, Op_Id);
2596 Op_Id := Homonym (Op_Id);
2601 end Analyze_Negation;
2607 procedure Analyze_Null (N : Node_Id) is
2609 Mark_Non_ALFA_Subprogram;
2610 Check_SPARK_Restriction ("null is not allowed", N);
2612 Set_Etype (N, Any_Access);
2615 ----------------------
2616 -- Analyze_One_Call --
2617 ----------------------
2619 procedure Analyze_One_Call
2623 Success : out Boolean;
2624 Skip_First : Boolean := False)
2626 Actuals : constant List_Id := Parameter_Associations (N);
2627 Prev_T : constant Entity_Id := Etype (N);
2629 Must_Skip : constant Boolean := Skip_First
2630 or else Nkind (Original_Node (N)) = N_Selected_Component
2632 (Nkind (Original_Node (N)) = N_Indexed_Component
2633 and then Nkind (Prefix (Original_Node (N)))
2634 = N_Selected_Component);
2635 -- The first formal must be omitted from the match when trying to find
2636 -- a primitive operation that is a possible interpretation, and also
2637 -- after the call has been rewritten, because the corresponding actual
2638 -- is already known to be compatible, and because this may be an
2639 -- indexing of a call with default parameters.
2643 Is_Indexed : Boolean := False;
2644 Is_Indirect : Boolean := False;
2645 Subp_Type : constant Entity_Id := Etype (Nam);
2648 function Operator_Hidden_By (Fun : Entity_Id) return Boolean;
2649 -- There may be a user-defined operator that hides the current
2650 -- interpretation. We must check for this independently of the
2651 -- analysis of the call with the user-defined operation, because
2652 -- the parameter names may be wrong and yet the hiding takes place.
2653 -- This fixes a problem with ACATS test B34014O.
2655 -- When the type Address is a visible integer type, and the DEC
2656 -- system extension is visible, the predefined operator may be
2657 -- hidden as well, by one of the address operations in auxdec.
2658 -- Finally, The abstract operations on address do not hide the
2659 -- predefined operator (this is the purpose of making them abstract).
2661 procedure Indicate_Name_And_Type;
2662 -- If candidate interpretation matches, indicate name and type of
2663 -- result on call node.
2665 ----------------------------
2666 -- Indicate_Name_And_Type --
2667 ----------------------------
2669 procedure Indicate_Name_And_Type is
2671 Add_One_Interp (N, Nam, Etype (Nam));
2674 -- If the prefix of the call is a name, indicate the entity
2675 -- being called. If it is not a name, it is an expression that
2676 -- denotes an access to subprogram or else an entry or family. In
2677 -- the latter case, the name is a selected component, and the entity
2678 -- being called is noted on the selector.
2680 if not Is_Type (Nam) then
2681 if Is_Entity_Name (Name (N)) then
2682 Set_Entity (Name (N), Nam);
2684 elsif Nkind (Name (N)) = N_Selected_Component then
2685 Set_Entity (Selector_Name (Name (N)), Nam);
2689 if Debug_Flag_E and not Report then
2690 Write_Str (" Overloaded call ");
2691 Write_Int (Int (N));
2692 Write_Str (" compatible with ");
2693 Write_Int (Int (Nam));
2696 end Indicate_Name_And_Type;
2698 ------------------------
2699 -- Operator_Hidden_By --
2700 ------------------------
2702 function Operator_Hidden_By (Fun : Entity_Id) return Boolean is
2703 Act1 : constant Node_Id := First_Actual (N);
2704 Act2 : constant Node_Id := Next_Actual (Act1);
2705 Form1 : constant Entity_Id := First_Formal (Fun);
2706 Form2 : constant Entity_Id := Next_Formal (Form1);
2709 if Ekind (Fun) /= E_Function
2710 or else Is_Abstract_Subprogram (Fun)
2714 elsif not Has_Compatible_Type (Act1, Etype (Form1)) then
2717 elsif Present (Form2) then
2719 No (Act2) or else not Has_Compatible_Type (Act2, Etype (Form2))
2724 elsif Present (Act2) then
2728 -- Now we know that the arity of the operator matches the function,
2729 -- and the function call is a valid interpretation. The function
2730 -- hides the operator if it has the right signature, or if one of
2731 -- its operands is a non-abstract operation on Address when this is
2732 -- a visible integer type.
2734 return Hides_Op (Fun, Nam)
2735 or else Is_Descendent_Of_Address (Etype (Form1))
2738 and then Is_Descendent_Of_Address (Etype (Form2)));
2739 end Operator_Hidden_By;
2741 -- Start of processing for Analyze_One_Call
2746 -- If the subprogram has no formals or if all the formals have defaults,
2747 -- and the return type is an array type, the node may denote an indexing
2748 -- of the result of a parameterless call. In Ada 2005, the subprogram
2749 -- may have one non-defaulted formal, and the call may have been written
2750 -- in prefix notation, so that the rebuilt parameter list has more than
2753 if not Is_Overloadable (Nam)
2754 and then Ekind (Nam) /= E_Subprogram_Type
2755 and then Ekind (Nam) /= E_Entry_Family
2760 -- An indexing requires at least one actual
2762 if not Is_Empty_List (Actuals)
2764 (Needs_No_Actuals (Nam)
2766 (Needs_One_Actual (Nam)
2767 and then Present (Next_Actual (First (Actuals)))))
2769 if Is_Array_Type (Subp_Type) then
2770 Is_Indexed := Try_Indexed_Call (N, Nam, Subp_Type, Must_Skip);
2772 elsif Is_Access_Type (Subp_Type)
2773 and then Is_Array_Type (Designated_Type (Subp_Type))
2777 (N, Nam, Designated_Type (Subp_Type), Must_Skip);
2779 -- The prefix can also be a parameterless function that returns an
2780 -- access to subprogram, in which case this is an indirect call.
2781 -- If this succeeds, an explicit dereference is added later on,
2782 -- in Analyze_Call or Resolve_Call.
2784 elsif Is_Access_Type (Subp_Type)
2785 and then Ekind (Designated_Type (Subp_Type)) = E_Subprogram_Type
2787 Is_Indirect := Try_Indirect_Call (N, Nam, Subp_Type);
2792 -- If the call has been transformed into a slice, it is of the form
2793 -- F (Subtype) where F is parameterless. The node has been rewritten in
2794 -- Try_Indexed_Call and there is nothing else to do.
2797 and then Nkind (N) = N_Slice
2803 (N, Nam, (Report and not Is_Indexed and not Is_Indirect), Norm_OK);
2807 -- If an indirect call is a possible interpretation, indicate
2808 -- success to the caller.
2814 -- Mismatch in number or names of parameters
2816 elsif Debug_Flag_E then
2817 Write_Str (" normalization fails in call ");
2818 Write_Int (Int (N));
2819 Write_Str (" with subprogram ");
2820 Write_Int (Int (Nam));
2824 -- If the context expects a function call, discard any interpretation
2825 -- that is a procedure. If the node is not overloaded, leave as is for
2826 -- better error reporting when type mismatch is found.
2828 elsif Nkind (N) = N_Function_Call
2829 and then Is_Overloaded (Name (N))
2830 and then Ekind (Nam) = E_Procedure
2834 -- Ditto for function calls in a procedure context
2836 elsif Nkind (N) = N_Procedure_Call_Statement
2837 and then Is_Overloaded (Name (N))
2838 and then Etype (Nam) /= Standard_Void_Type
2842 elsif No (Actuals) then
2844 -- If Normalize succeeds, then there are default parameters for
2847 Indicate_Name_And_Type;
2849 elsif Ekind (Nam) = E_Operator then
2850 if Nkind (N) = N_Procedure_Call_Statement then
2854 -- This can occur when the prefix of the call is an operator
2855 -- name or an expanded name whose selector is an operator name.
2857 Analyze_Operator_Call (N, Nam);
2859 if Etype (N) /= Prev_T then
2861 -- Check that operator is not hidden by a function interpretation
2863 if Is_Overloaded (Name (N)) then
2869 Get_First_Interp (Name (N), I, It);
2870 while Present (It.Nam) loop
2871 if Operator_Hidden_By (It.Nam) then
2872 Set_Etype (N, Prev_T);
2876 Get_Next_Interp (I, It);
2881 -- If operator matches formals, record its name on the call.
2882 -- If the operator is overloaded, Resolve will select the
2883 -- correct one from the list of interpretations. The call
2884 -- node itself carries the first candidate.
2886 Set_Entity (Name (N), Nam);
2889 elsif Report and then Etype (N) = Any_Type then
2890 Error_Msg_N ("incompatible arguments for operator", N);
2894 -- Normalize_Actuals has chained the named associations in the
2895 -- correct order of the formals.
2897 Actual := First_Actual (N);
2898 Formal := First_Formal (Nam);
2900 -- If we are analyzing a call rewritten from object notation,
2901 -- skip first actual, which may be rewritten later as an
2902 -- explicit dereference.
2905 Next_Actual (Actual);
2906 Next_Formal (Formal);
2909 while Present (Actual) and then Present (Formal) loop
2910 if Nkind (Parent (Actual)) /= N_Parameter_Association
2911 or else Chars (Selector_Name (Parent (Actual))) = Chars (Formal)
2913 -- The actual can be compatible with the formal, but we must
2914 -- also check that the context is not an address type that is
2915 -- visibly an integer type, as is the case in VMS_64. In this
2916 -- case the use of literals is illegal, except in the body of
2917 -- descendents of system, where arithmetic operations on
2918 -- address are of course used.
2920 if Has_Compatible_Type (Actual, Etype (Formal))
2922 (Etype (Actual) /= Universal_Integer
2923 or else not Is_Descendent_Of_Address (Etype (Formal))
2925 Is_Predefined_File_Name
2926 (Unit_File_Name (Get_Source_Unit (N))))
2928 Next_Actual (Actual);
2929 Next_Formal (Formal);
2932 if Debug_Flag_E then
2933 Write_Str (" type checking fails in call ");
2934 Write_Int (Int (N));
2935 Write_Str (" with formal ");
2936 Write_Int (Int (Formal));
2937 Write_Str (" in subprogram ");
2938 Write_Int (Int (Nam));
2942 if Report and not Is_Indexed and not Is_Indirect then
2944 -- Ada 2005 (AI-251): Complete the error notification
2945 -- to help new Ada 2005 users.
2947 if Is_Class_Wide_Type (Etype (Formal))
2948 and then Is_Interface (Etype (Etype (Formal)))
2949 and then not Interface_Present_In_Ancestor
2950 (Typ => Etype (Actual),
2951 Iface => Etype (Etype (Formal)))
2954 ("(Ada 2005) does not implement interface }",
2955 Actual, Etype (Etype (Formal)));
2958 Wrong_Type (Actual, Etype (Formal));
2960 if Nkind (Actual) = N_Op_Eq
2961 and then Nkind (Left_Opnd (Actual)) = N_Identifier
2963 Formal := First_Formal (Nam);
2964 while Present (Formal) loop
2965 if Chars (Left_Opnd (Actual)) = Chars (Formal) then
2966 Error_Msg_N -- CODEFIX
2967 ("possible misspelling of `='>`!", Actual);
2971 Next_Formal (Formal);
2975 if All_Errors_Mode then
2976 Error_Msg_Sloc := Sloc (Nam);
2978 if Etype (Formal) = Any_Type then
2980 ("there is no legal actual parameter", Actual);
2983 if Is_Overloadable (Nam)
2984 and then Present (Alias (Nam))
2985 and then not Comes_From_Source (Nam)
2988 ("\\ =='> in call to inherited operation & #!",
2991 elsif Ekind (Nam) = E_Subprogram_Type then
2993 Access_To_Subprogram_Typ :
2994 constant Entity_Id :=
2996 (Associated_Node_For_Itype (Nam));
2999 "\\ =='> in call to dereference of &#!",
3000 Actual, Access_To_Subprogram_Typ);
3005 ("\\ =='> in call to &#!", Actual, Nam);
3015 -- Normalize_Actuals has verified that a default value exists
3016 -- for this formal. Current actual names a subsequent formal.
3018 Next_Formal (Formal);
3022 -- On exit, all actuals match
3024 Indicate_Name_And_Type;
3026 end Analyze_One_Call;
3028 ---------------------------
3029 -- Analyze_Operator_Call --
3030 ---------------------------
3032 procedure Analyze_Operator_Call (N : Node_Id; Op_Id : Entity_Id) is
3033 Op_Name : constant Name_Id := Chars (Op_Id);
3034 Act1 : constant Node_Id := First_Actual (N);
3035 Act2 : constant Node_Id := Next_Actual (Act1);
3038 -- Binary operator case
3040 if Present (Act2) then
3042 -- If more than two operands, then not binary operator after all
3044 if Present (Next_Actual (Act2)) then
3047 elsif Op_Name = Name_Op_Add
3048 or else Op_Name = Name_Op_Subtract
3049 or else Op_Name = Name_Op_Multiply
3050 or else Op_Name = Name_Op_Divide
3051 or else Op_Name = Name_Op_Mod
3052 or else Op_Name = Name_Op_Rem
3053 or else Op_Name = Name_Op_Expon
3055 Find_Arithmetic_Types (Act1, Act2, Op_Id, N);
3057 elsif Op_Name = Name_Op_And
3058 or else Op_Name = Name_Op_Or
3059 or else Op_Name = Name_Op_Xor
3061 Find_Boolean_Types (Act1, Act2, Op_Id, N);
3063 elsif Op_Name = Name_Op_Lt
3064 or else Op_Name = Name_Op_Le
3065 or else Op_Name = Name_Op_Gt
3066 or else Op_Name = Name_Op_Ge
3068 Find_Comparison_Types (Act1, Act2, Op_Id, N);
3070 elsif Op_Name = Name_Op_Eq
3071 or else Op_Name = Name_Op_Ne
3073 Find_Equality_Types (Act1, Act2, Op_Id, N);
3075 elsif Op_Name = Name_Op_Concat then
3076 Find_Concatenation_Types (Act1, Act2, Op_Id, N);
3078 -- Is this else null correct, or should it be an abort???
3084 -- Unary operator case
3087 if Op_Name = Name_Op_Subtract or else
3088 Op_Name = Name_Op_Add or else
3089 Op_Name = Name_Op_Abs
3091 Find_Unary_Types (Act1, Op_Id, N);
3094 Op_Name = Name_Op_Not
3096 Find_Negation_Types (Act1, Op_Id, N);
3098 -- Is this else null correct, or should it be an abort???
3104 end Analyze_Operator_Call;
3106 -------------------------------------------
3107 -- Analyze_Overloaded_Selected_Component --
3108 -------------------------------------------
3110 procedure Analyze_Overloaded_Selected_Component (N : Node_Id) is
3111 Nam : constant Node_Id := Prefix (N);
3112 Sel : constant Node_Id := Selector_Name (N);
3119 Set_Etype (Sel, Any_Type);
3121 Get_First_Interp (Nam, I, It);
3122 while Present (It.Typ) loop
3123 if Is_Access_Type (It.Typ) then
3124 T := Designated_Type (It.Typ);
3125 Error_Msg_NW (Warn_On_Dereference, "?implicit dereference", N);
3130 if Is_Record_Type (T) then
3132 -- If the prefix is a class-wide type, the visible components are
3133 -- those of the base type.
3135 if Is_Class_Wide_Type (T) then
3139 Comp := First_Entity (T);
3140 while Present (Comp) loop
3141 if Chars (Comp) = Chars (Sel)
3142 and then Is_Visible_Component (Comp)
3145 -- AI05-105: if the context is an object renaming with
3146 -- an anonymous access type, the expected type of the
3147 -- object must be anonymous. This is a name resolution rule.
3149 if Nkind (Parent (N)) /= N_Object_Renaming_Declaration
3150 or else No (Access_Definition (Parent (N)))
3151 or else Ekind (Etype (Comp)) = E_Anonymous_Access_Type
3153 Ekind (Etype (Comp)) = E_Anonymous_Access_Subprogram_Type
3155 Set_Entity (Sel, Comp);
3156 Set_Etype (Sel, Etype (Comp));
3157 Add_One_Interp (N, Etype (Comp), Etype (Comp));
3159 -- This also specifies a candidate to resolve the name.
3160 -- Further overloading will be resolved from context.
3161 -- The selector name itself does not carry overloading
3164 Set_Etype (Nam, It.Typ);
3167 -- Named access type in the context of a renaming
3168 -- declaration with an access definition. Remove
3169 -- inapplicable candidate.
3178 elsif Is_Concurrent_Type (T) then
3179 Comp := First_Entity (T);
3180 while Present (Comp)
3181 and then Comp /= First_Private_Entity (T)
3183 if Chars (Comp) = Chars (Sel) then
3184 if Is_Overloadable (Comp) then
3185 Add_One_Interp (Sel, Comp, Etype (Comp));
3187 Set_Entity_With_Style_Check (Sel, Comp);
3188 Generate_Reference (Comp, Sel);
3191 Set_Etype (Sel, Etype (Comp));
3192 Set_Etype (N, Etype (Comp));
3193 Set_Etype (Nam, It.Typ);
3195 -- For access type case, introduce explicit dereference for
3196 -- more uniform treatment of entry calls. Do this only once
3197 -- if several interpretations yield an access type.
3199 if Is_Access_Type (Etype (Nam))
3200 and then Nkind (Nam) /= N_Explicit_Dereference
3202 Insert_Explicit_Dereference (Nam);
3204 (Warn_On_Dereference, "?implicit dereference", N);
3211 Set_Is_Overloaded (N, Is_Overloaded (Sel));
3214 Get_Next_Interp (I, It);
3217 if Etype (N) = Any_Type
3218 and then not Try_Object_Operation (N)
3220 Error_Msg_NE ("undefined selector& for overloaded prefix", N, Sel);
3221 Set_Entity (Sel, Any_Id);
3222 Set_Etype (Sel, Any_Type);
3224 end Analyze_Overloaded_Selected_Component;
3226 ----------------------------------
3227 -- Analyze_Qualified_Expression --
3228 ----------------------------------
3230 procedure Analyze_Qualified_Expression (N : Node_Id) is
3231 Mark : constant Entity_Id := Subtype_Mark (N);
3232 Expr : constant Node_Id := Expression (N);
3238 Mark_Non_ALFA_Subprogram;
3240 Analyze_Expression (Expr);
3242 Set_Etype (N, Any_Type);
3247 if T = Any_Type then
3251 Check_Fully_Declared (T, N);
3253 -- If expected type is class-wide, check for exact match before
3254 -- expansion, because if the expression is a dispatching call it
3255 -- may be rewritten as explicit dereference with class-wide result.
3256 -- If expression is overloaded, retain only interpretations that
3257 -- will yield exact matches.
3259 if Is_Class_Wide_Type (T) then
3260 if not Is_Overloaded (Expr) then
3261 if Base_Type (Etype (Expr)) /= Base_Type (T) then
3262 if Nkind (Expr) = N_Aggregate then
3263 Error_Msg_N ("type of aggregate cannot be class-wide", Expr);
3265 Wrong_Type (Expr, T);
3270 Get_First_Interp (Expr, I, It);
3272 while Present (It.Nam) loop
3273 if Base_Type (It.Typ) /= Base_Type (T) then
3277 Get_Next_Interp (I, It);
3283 end Analyze_Qualified_Expression;
3285 -----------------------------------
3286 -- Analyze_Quantified_Expression --
3287 -----------------------------------
3289 procedure Analyze_Quantified_Expression (N : Node_Id) is
3290 Loc : constant Source_Ptr := Sloc (N);
3291 Ent : constant Entity_Id :=
3293 (E_Loop, Current_Scope, Sloc (N), 'L');
3298 Mark_Non_ALFA_Subprogram;
3299 Check_SPARK_Restriction ("quantified expression is not allowed", N);
3301 Set_Etype (Ent, Standard_Void_Type);
3302 Set_Parent (Ent, N);
3304 if Present (Loop_Parameter_Specification (N)) then
3306 Make_Iteration_Scheme (Loc,
3307 Loop_Parameter_Specification =>
3308 Loop_Parameter_Specification (N));
3311 Make_Iteration_Scheme (Loc,
3312 Iterator_Specification =>
3313 Iterator_Specification (N));
3317 Set_Parent (Iterator, N);
3318 Analyze_Iteration_Scheme (Iterator);
3320 -- The loop specification may have been converted into an
3321 -- iterator specification during its analysis. Update the
3322 -- quantified node accordingly.
3324 if Present (Iterator_Specification (Iterator)) then
3325 Set_Iterator_Specification
3326 (N, Iterator_Specification (Iterator));
3327 Set_Loop_Parameter_Specification (N, Empty);
3330 Analyze (Condition (N));
3333 Set_Etype (N, Standard_Boolean);
3334 end Analyze_Quantified_Expression;
3340 procedure Analyze_Range (N : Node_Id) is
3341 L : constant Node_Id := Low_Bound (N);
3342 H : constant Node_Id := High_Bound (N);
3343 I1, I2 : Interp_Index;
3346 procedure Check_Common_Type (T1, T2 : Entity_Id);
3347 -- Verify the compatibility of two types, and choose the
3348 -- non universal one if the other is universal.
3350 procedure Check_High_Bound (T : Entity_Id);
3351 -- Test one interpretation of the low bound against all those
3352 -- of the high bound.
3354 procedure Check_Universal_Expression (N : Node_Id);
3355 -- In Ada83, reject bounds of a universal range that are not
3356 -- literals or entity names.
3358 -----------------------
3359 -- Check_Common_Type --
3360 -----------------------
3362 procedure Check_Common_Type (T1, T2 : Entity_Id) is
3364 if Covers (T1 => T1, T2 => T2)
3366 Covers (T1 => T2, T2 => T1)
3368 if T1 = Universal_Integer
3369 or else T1 = Universal_Real
3370 or else T1 = Any_Character
3372 Add_One_Interp (N, Base_Type (T2), Base_Type (T2));
3375 Add_One_Interp (N, T1, T1);
3378 Add_One_Interp (N, Base_Type (T1), Base_Type (T1));
3381 end Check_Common_Type;
3383 ----------------------
3384 -- Check_High_Bound --
3385 ----------------------
3387 procedure Check_High_Bound (T : Entity_Id) is
3389 if not Is_Overloaded (H) then
3390 Check_Common_Type (T, Etype (H));
3392 Get_First_Interp (H, I2, It2);
3393 while Present (It2.Typ) loop
3394 Check_Common_Type (T, It2.Typ);
3395 Get_Next_Interp (I2, It2);
3398 end Check_High_Bound;
3400 -----------------------------
3401 -- Is_Universal_Expression --
3402 -----------------------------
3404 procedure Check_Universal_Expression (N : Node_Id) is
3406 if Etype (N) = Universal_Integer
3407 and then Nkind (N) /= N_Integer_Literal
3408 and then not Is_Entity_Name (N)
3409 and then Nkind (N) /= N_Attribute_Reference
3411 Error_Msg_N ("illegal bound in discrete range", N);
3413 end Check_Universal_Expression;
3415 -- Start of processing for Analyze_Range
3418 Set_Etype (N, Any_Type);
3419 Analyze_Expression (L);
3420 Analyze_Expression (H);
3422 if Etype (L) = Any_Type or else Etype (H) = Any_Type then
3426 if not Is_Overloaded (L) then
3427 Check_High_Bound (Etype (L));
3429 Get_First_Interp (L, I1, It1);
3430 while Present (It1.Typ) loop
3431 Check_High_Bound (It1.Typ);
3432 Get_Next_Interp (I1, It1);
3436 -- If result is Any_Type, then we did not find a compatible pair
3438 if Etype (N) = Any_Type then
3439 Error_Msg_N ("incompatible types in range ", N);
3443 if Ada_Version = Ada_83
3445 (Nkind (Parent (N)) = N_Loop_Parameter_Specification
3446 or else Nkind (Parent (N)) = N_Constrained_Array_Definition)
3448 Check_Universal_Expression (L);
3449 Check_Universal_Expression (H);
3453 -----------------------
3454 -- Analyze_Reference --
3455 -----------------------
3457 procedure Analyze_Reference (N : Node_Id) is
3458 P : constant Node_Id := Prefix (N);
3461 Acc_Type : Entity_Id;
3464 Mark_Non_ALFA_Subprogram;
3468 -- An interesting error check, if we take the 'Reference of an object
3469 -- for which a pragma Atomic or Volatile has been given, and the type
3470 -- of the object is not Atomic or Volatile, then we are in trouble. The
3471 -- problem is that no trace of the atomic/volatile status will remain
3472 -- for the backend to respect when it deals with the resulting pointer,
3473 -- since the pointer type will not be marked atomic (it is a pointer to
3474 -- the base type of the object).
3476 -- It is not clear if that can ever occur, but in case it does, we will
3477 -- generate an error message. Not clear if this message can ever be
3478 -- generated, and pretty clear that it represents a bug if it is, still
3479 -- seems worth checking, except in CodePeer mode where we do not really
3480 -- care and don't want to bother the user.
3484 if Is_Entity_Name (P)
3485 and then Is_Object_Reference (P)
3486 and then not CodePeer_Mode
3491 if (Has_Atomic_Components (E)
3492 and then not Has_Atomic_Components (T))
3494 (Has_Volatile_Components (E)
3495 and then not Has_Volatile_Components (T))
3496 or else (Is_Atomic (E) and then not Is_Atomic (T))
3497 or else (Is_Volatile (E) and then not Is_Volatile (T))
3499 Error_Msg_N ("cannot take reference to Atomic/Volatile object", N);
3503 -- Carry on with normal processing
3505 Acc_Type := Create_Itype (E_Allocator_Type, N);
3506 Set_Etype (Acc_Type, Acc_Type);
3507 Set_Directly_Designated_Type (Acc_Type, Etype (P));
3508 Set_Etype (N, Acc_Type);
3509 end Analyze_Reference;
3511 --------------------------------
3512 -- Analyze_Selected_Component --
3513 --------------------------------
3515 -- Prefix is a record type or a task or protected type. In the latter case,
3516 -- the selector must denote a visible entry.
3518 procedure Analyze_Selected_Component (N : Node_Id) is
3519 Name : constant Node_Id := Prefix (N);
3520 Sel : constant Node_Id := Selector_Name (N);
3523 Has_Candidate : Boolean := False;
3526 Pent : Entity_Id := Empty;
3527 Prefix_Type : Entity_Id;
3529 Type_To_Use : Entity_Id;
3530 -- In most cases this is the Prefix_Type, but if the Prefix_Type is
3531 -- a class-wide type, we use its root type, whose components are
3532 -- present in the class-wide type.
3534 Is_Single_Concurrent_Object : Boolean;
3535 -- Set True if the prefix is a single task or a single protected object
3537 procedure Find_Component_In_Instance (Rec : Entity_Id);
3538 -- In an instance, a component of a private extension may not be visible
3539 -- while it was visible in the generic. Search candidate scope for a
3540 -- component with the proper identifier. This is only done if all other
3541 -- searches have failed. When the match is found (it always will be),
3542 -- the Etype of both N and Sel are set from this component, and the
3543 -- entity of Sel is set to reference this component.
3545 function Has_Mode_Conformant_Spec (Comp : Entity_Id) return Boolean;
3546 -- It is known that the parent of N denotes a subprogram call. Comp
3547 -- is an overloadable component of the concurrent type of the prefix.
3548 -- Determine whether all formals of the parent of N and Comp are mode
3549 -- conformant. If the parent node is not analyzed yet it may be an
3550 -- indexed component rather than a function call.
3552 --------------------------------
3553 -- Find_Component_In_Instance --
3554 --------------------------------
3556 procedure Find_Component_In_Instance (Rec : Entity_Id) is
3560 Comp := First_Component (Rec);
3561 while Present (Comp) loop
3562 if Chars (Comp) = Chars (Sel) then
3563 Set_Entity_With_Style_Check (Sel, Comp);
3564 Set_Etype (Sel, Etype (Comp));
3565 Set_Etype (N, Etype (Comp));
3569 Next_Component (Comp);
3572 -- This must succeed because code was legal in the generic
3574 raise Program_Error;
3575 end Find_Component_In_Instance;
3577 ------------------------------
3578 -- Has_Mode_Conformant_Spec --
3579 ------------------------------
3581 function Has_Mode_Conformant_Spec (Comp : Entity_Id) return Boolean is
3582 Comp_Param : Entity_Id;
3584 Param_Typ : Entity_Id;
3587 Comp_Param := First_Formal (Comp);
3589 if Nkind (Parent (N)) = N_Indexed_Component then
3590 Param := First (Expressions (Parent (N)));
3592 Param := First (Parameter_Associations (Parent (N)));
3595 while Present (Comp_Param)
3596 and then Present (Param)
3598 Param_Typ := Find_Parameter_Type (Param);
3600 if Present (Param_Typ)
3602 not Conforming_Types
3603 (Etype (Comp_Param), Param_Typ, Mode_Conformant)
3608 Next_Formal (Comp_Param);
3612 -- One of the specs has additional formals
3614 if Present (Comp_Param) or else Present (Param) then
3619 end Has_Mode_Conformant_Spec;
3621 -- Start of processing for Analyze_Selected_Component
3624 Set_Etype (N, Any_Type);
3626 if Is_Overloaded (Name) then
3627 Analyze_Overloaded_Selected_Component (N);
3630 elsif Etype (Name) = Any_Type then
3631 Set_Entity (Sel, Any_Id);
3632 Set_Etype (Sel, Any_Type);
3636 Prefix_Type := Etype (Name);
3639 if Is_Access_Type (Prefix_Type) then
3641 -- A RACW object can never be used as prefix of a selected component
3642 -- since that means it is dereferenced without being a controlling
3643 -- operand of a dispatching operation (RM E.2.2(16/1)). Before
3644 -- reporting an error, we must check whether this is actually a
3645 -- dispatching call in prefix form.
3647 if Is_Remote_Access_To_Class_Wide_Type (Prefix_Type)
3648 and then Comes_From_Source (N)
3650 if Try_Object_Operation (N) then
3654 ("invalid dereference of a remote access-to-class-wide value",
3658 -- Normal case of selected component applied to access type
3661 Error_Msg_NW (Warn_On_Dereference, "?implicit dereference", N);
3663 if Is_Entity_Name (Name) then
3664 Pent := Entity (Name);
3665 elsif Nkind (Name) = N_Selected_Component
3666 and then Is_Entity_Name (Selector_Name (Name))
3668 Pent := Entity (Selector_Name (Name));
3671 Prefix_Type := Process_Implicit_Dereference_Prefix (Pent, Name);
3674 -- If we have an explicit dereference of a remote access-to-class-wide
3675 -- value, then issue an error (see RM-E.2.2(16/1)). However we first
3676 -- have to check for the case of a prefix that is a controlling operand
3677 -- of a prefixed dispatching call, as the dereference is legal in that
3678 -- case. Normally this condition is checked in Validate_Remote_Access_
3679 -- To_Class_Wide_Type, but we have to defer the checking for selected
3680 -- component prefixes because of the prefixed dispatching call case.
3681 -- Note that implicit dereferences are checked for this just above.
3683 elsif Nkind (Name) = N_Explicit_Dereference
3684 and then Is_Remote_Access_To_Class_Wide_Type (Etype (Prefix (Name)))
3685 and then Comes_From_Source (N)
3687 if Try_Object_Operation (N) then
3691 ("invalid dereference of a remote access-to-class-wide value",
3696 -- (Ada 2005): if the prefix is the limited view of a type, and
3697 -- the context already includes the full view, use the full view
3698 -- in what follows, either to retrieve a component of to find
3699 -- a primitive operation. If the prefix is an explicit dereference,
3700 -- set the type of the prefix to reflect this transformation.
3701 -- If the non-limited view is itself an incomplete type, get the
3702 -- full view if available.
3704 if Is_Incomplete_Type (Prefix_Type)
3705 and then From_With_Type (Prefix_Type)
3706 and then Present (Non_Limited_View (Prefix_Type))
3708 Prefix_Type := Get_Full_View (Non_Limited_View (Prefix_Type));
3710 if Nkind (N) = N_Explicit_Dereference then
3711 Set_Etype (Prefix (N), Prefix_Type);
3714 elsif Ekind (Prefix_Type) = E_Class_Wide_Type
3715 and then From_With_Type (Prefix_Type)
3716 and then Present (Non_Limited_View (Etype (Prefix_Type)))
3719 Class_Wide_Type (Non_Limited_View (Etype (Prefix_Type)));
3721 if Nkind (N) = N_Explicit_Dereference then
3722 Set_Etype (Prefix (N), Prefix_Type);
3726 if Ekind (Prefix_Type) = E_Private_Subtype then
3727 Prefix_Type := Base_Type (Prefix_Type);
3730 Type_To_Use := Prefix_Type;
3732 -- For class-wide types, use the entity list of the root type. This
3733 -- indirection is specially important for private extensions because
3734 -- only the root type get switched (not the class-wide type).
3736 if Is_Class_Wide_Type (Prefix_Type) then
3737 Type_To_Use := Root_Type (Prefix_Type);
3740 -- If the prefix is a single concurrent object, use its name in error
3741 -- messages, rather than that of its anonymous type.
3743 Is_Single_Concurrent_Object :=
3744 Is_Concurrent_Type (Prefix_Type)
3745 and then Is_Internal_Name (Chars (Prefix_Type))
3746 and then not Is_Derived_Type (Prefix_Type)
3747 and then Is_Entity_Name (Name);
3749 Comp := First_Entity (Type_To_Use);
3751 -- If the selector has an original discriminant, the node appears in
3752 -- an instance. Replace the discriminant with the corresponding one
3753 -- in the current discriminated type. For nested generics, this must
3754 -- be done transitively, so note the new original discriminant.
3756 if Nkind (Sel) = N_Identifier
3757 and then Present (Original_Discriminant (Sel))
3759 Comp := Find_Corresponding_Discriminant (Sel, Prefix_Type);
3761 -- Mark entity before rewriting, for completeness and because
3762 -- subsequent semantic checks might examine the original node.
3764 Set_Entity (Sel, Comp);
3765 Rewrite (Selector_Name (N),
3766 New_Occurrence_Of (Comp, Sloc (N)));
3767 Set_Original_Discriminant (Selector_Name (N), Comp);
3768 Set_Etype (N, Etype (Comp));
3770 if Is_Access_Type (Etype (Name)) then
3771 Insert_Explicit_Dereference (Name);
3772 Error_Msg_NW (Warn_On_Dereference, "?implicit dereference", N);
3775 elsif Is_Record_Type (Prefix_Type) then
3777 -- Find component with given name
3779 while Present (Comp) loop
3780 if Chars (Comp) = Chars (Sel)
3781 and then Is_Visible_Component (Comp)
3783 Set_Entity_With_Style_Check (Sel, Comp);
3784 Set_Etype (Sel, Etype (Comp));
3786 if Ekind (Comp) = E_Discriminant then
3787 if Is_Unchecked_Union (Base_Type (Prefix_Type)) then
3789 ("cannot reference discriminant of Unchecked_Union",
3793 if Is_Generic_Type (Prefix_Type)
3795 Is_Generic_Type (Root_Type (Prefix_Type))
3797 Set_Original_Discriminant (Sel, Comp);
3801 -- Resolve the prefix early otherwise it is not possible to
3802 -- build the actual subtype of the component: it may need
3803 -- to duplicate this prefix and duplication is only allowed
3804 -- on fully resolved expressions.
3808 -- Ada 2005 (AI-50217): Check wrong use of incomplete types or
3809 -- subtypes in a package specification.
3812 -- limited with Pkg;
3814 -- type Acc_Inc is access Pkg.T;
3816 -- N : Natural := X.all.Comp; -- ERROR, limited view
3817 -- end Pkg; -- Comp is not visible
3819 if Nkind (Name) = N_Explicit_Dereference
3820 and then From_With_Type (Etype (Prefix (Name)))
3821 and then not Is_Potentially_Use_Visible (Etype (Name))
3822 and then Nkind (Parent (Cunit_Entity (Current_Sem_Unit))) =
3823 N_Package_Specification
3826 ("premature usage of incomplete}", Prefix (Name),
3827 Etype (Prefix (Name)));
3830 -- We never need an actual subtype for the case of a selection
3831 -- for a indexed component of a non-packed array, since in
3832 -- this case gigi generates all the checks and can find the
3833 -- necessary bounds information.
3835 -- We also do not need an actual subtype for the case of a
3836 -- first, last, length, or range attribute applied to a
3837 -- non-packed array, since gigi can again get the bounds in
3838 -- these cases (gigi cannot handle the packed case, since it
3839 -- has the bounds of the packed array type, not the original
3840 -- bounds of the type). However, if the prefix is itself a
3841 -- selected component, as in a.b.c (i), gigi may regard a.b.c
3842 -- as a dynamic-sized temporary, so we do generate an actual
3843 -- subtype for this case.
3845 Parent_N := Parent (N);
3847 if not Is_Packed (Etype (Comp))
3849 ((Nkind (Parent_N) = N_Indexed_Component
3850 and then Nkind (Name) /= N_Selected_Component)
3852 (Nkind (Parent_N) = N_Attribute_Reference
3853 and then (Attribute_Name (Parent_N) = Name_First
3855 Attribute_Name (Parent_N) = Name_Last
3857 Attribute_Name (Parent_N) = Name_Length
3859 Attribute_Name (Parent_N) = Name_Range)))
3861 Set_Etype (N, Etype (Comp));
3863 -- If full analysis is not enabled, we do not generate an
3864 -- actual subtype, because in the absence of expansion
3865 -- reference to a formal of a protected type, for example,
3866 -- will not be properly transformed, and will lead to
3867 -- out-of-scope references in gigi.
3869 -- In all other cases, we currently build an actual subtype.
3870 -- It seems likely that many of these cases can be avoided,
3871 -- but right now, the front end makes direct references to the
3872 -- bounds (e.g. in generating a length check), and if we do
3873 -- not make an actual subtype, we end up getting a direct
3874 -- reference to a discriminant, which will not do.
3876 elsif Full_Analysis then
3878 Build_Actual_Subtype_Of_Component (Etype (Comp), N);
3879 Insert_Action (N, Act_Decl);
3881 if No (Act_Decl) then
3882 Set_Etype (N, Etype (Comp));
3885 -- Component type depends on discriminants. Enter the
3886 -- main attributes of the subtype.
3889 Subt : constant Entity_Id :=
3890 Defining_Identifier (Act_Decl);
3893 Set_Etype (Subt, Base_Type (Etype (Comp)));
3894 Set_Ekind (Subt, Ekind (Etype (Comp)));
3895 Set_Etype (N, Subt);
3899 -- If Full_Analysis not enabled, just set the Etype
3902 Set_Etype (N, Etype (Comp));
3908 -- If the prefix is a private extension, check only the visible
3909 -- components of the partial view. This must include the tag,
3910 -- which can appear in expanded code in a tag check.
3912 if Ekind (Type_To_Use) = E_Record_Type_With_Private
3913 and then Chars (Selector_Name (N)) /= Name_uTag
3915 exit when Comp = Last_Entity (Type_To_Use);
3921 -- Ada 2005 (AI-252): The selected component can be interpreted as
3922 -- a prefixed view of a subprogram. Depending on the context, this is
3923 -- either a name that can appear in a renaming declaration, or part
3924 -- of an enclosing call given in prefix form.
3926 -- Ada 2005 (AI05-0030): In the case of dispatching requeue, the
3927 -- selected component should resolve to a name.
3929 if Ada_Version >= Ada_2005
3930 and then Is_Tagged_Type (Prefix_Type)
3931 and then not Is_Concurrent_Type (Prefix_Type)
3933 if Nkind (Parent (N)) = N_Generic_Association
3934 or else Nkind (Parent (N)) = N_Requeue_Statement
3935 or else Nkind (Parent (N)) = N_Subprogram_Renaming_Declaration
3937 if Find_Primitive_Operation (N) then
3941 elsif Try_Object_Operation (N) then
3945 -- If the transformation fails, it will be necessary to redo the
3946 -- analysis with all errors enabled, to indicate candidate
3947 -- interpretations and reasons for each failure ???
3951 elsif Is_Private_Type (Prefix_Type) then
3953 -- Allow access only to discriminants of the type. If the type has
3954 -- no full view, gigi uses the parent type for the components, so we
3955 -- do the same here.
3957 if No (Full_View (Prefix_Type)) then
3958 Type_To_Use := Root_Type (Base_Type (Prefix_Type));
3959 Comp := First_Entity (Type_To_Use);
3962 while Present (Comp) loop
3963 if Chars (Comp) = Chars (Sel) then
3964 if Ekind (Comp) = E_Discriminant then
3965 Set_Entity_With_Style_Check (Sel, Comp);
3966 Generate_Reference (Comp, Sel);
3968 Set_Etype (Sel, Etype (Comp));
3969 Set_Etype (N, Etype (Comp));
3971 if Is_Generic_Type (Prefix_Type)
3972 or else Is_Generic_Type (Root_Type (Prefix_Type))
3974 Set_Original_Discriminant (Sel, Comp);
3977 -- Before declaring an error, check whether this is tagged
3978 -- private type and a call to a primitive operation.
3980 elsif Ada_Version >= Ada_2005
3981 and then Is_Tagged_Type (Prefix_Type)
3982 and then Try_Object_Operation (N)
3987 Error_Msg_Node_2 := First_Subtype (Prefix_Type);
3988 Error_Msg_NE ("invisible selector& for }", N, Sel);
3989 Set_Entity (Sel, Any_Id);
3990 Set_Etype (N, Any_Type);
3999 elsif Is_Concurrent_Type (Prefix_Type) then
4001 -- Find visible operation with given name. For a protected type,
4002 -- the possible candidates are discriminants, entries or protected
4003 -- procedures. For a task type, the set can only include entries or
4004 -- discriminants if the task type is not an enclosing scope. If it
4005 -- is an enclosing scope (e.g. in an inner task) then all entities
4006 -- are visible, but the prefix must denote the enclosing scope, i.e.
4007 -- can only be a direct name or an expanded name.
4009 Set_Etype (Sel, Any_Type);
4010 In_Scope := In_Open_Scopes (Prefix_Type);
4012 while Present (Comp) loop
4013 if Chars (Comp) = Chars (Sel) then
4014 if Is_Overloadable (Comp) then
4015 Add_One_Interp (Sel, Comp, Etype (Comp));
4017 -- If the prefix is tagged, the correct interpretation may
4018 -- lie in the primitive or class-wide operations of the
4019 -- type. Perform a simple conformance check to determine
4020 -- whether Try_Object_Operation should be invoked even if
4021 -- a visible entity is found.
4023 if Is_Tagged_Type (Prefix_Type)
4025 Nkind_In (Parent (N), N_Procedure_Call_Statement,
4027 N_Indexed_Component)
4028 and then Has_Mode_Conformant_Spec (Comp)
4030 Has_Candidate := True;
4033 -- Note: a selected component may not denote a component of a
4034 -- protected type (4.1.3(7)).
4036 elsif Ekind_In (Comp, E_Discriminant, E_Entry_Family)
4038 and then not Is_Protected_Type (Prefix_Type)
4039 and then Is_Entity_Name (Name))
4041 Set_Entity_With_Style_Check (Sel, Comp);
4042 Generate_Reference (Comp, Sel);
4048 Set_Etype (Sel, Etype (Comp));
4049 Set_Etype (N, Etype (Comp));
4051 if Ekind (Comp) = E_Discriminant then
4052 Set_Original_Discriminant (Sel, Comp);
4055 -- For access type case, introduce explicit dereference for
4056 -- more uniform treatment of entry calls.
4058 if Is_Access_Type (Etype (Name)) then
4059 Insert_Explicit_Dereference (Name);
4061 (Warn_On_Dereference, "?implicit dereference", N);
4067 exit when not In_Scope
4069 Comp = First_Private_Entity (Base_Type (Prefix_Type));
4072 -- If there is no visible entity with the given name or none of the
4073 -- visible entities are plausible interpretations, check whether
4074 -- there is some other primitive operation with that name.
4076 if Ada_Version >= Ada_2005
4077 and then Is_Tagged_Type (Prefix_Type)
4079 if (Etype (N) = Any_Type
4080 or else not Has_Candidate)
4081 and then Try_Object_Operation (N)
4085 -- If the context is not syntactically a procedure call, it
4086 -- may be a call to a primitive function declared outside of
4087 -- the synchronized type.
4089 -- If the context is a procedure call, there might still be
4090 -- an overloading between an entry and a primitive procedure
4091 -- declared outside of the synchronized type, called in prefix
4092 -- notation. This is harder to disambiguate because in one case
4093 -- the controlling formal is implicit ???
4095 elsif Nkind (Parent (N)) /= N_Procedure_Call_Statement
4096 and then Nkind (Parent (N)) /= N_Indexed_Component
4097 and then Try_Object_Operation (N)
4103 if Etype (N) = Any_Type and then Is_Protected_Type (Prefix_Type) then
4104 -- Case of a prefix of a protected type: selector might denote
4105 -- an invisible private component.
4107 Comp := First_Private_Entity (Base_Type (Prefix_Type));
4108 while Present (Comp) and then Chars (Comp) /= Chars (Sel) loop
4112 if Present (Comp) then
4113 if Is_Single_Concurrent_Object then
4114 Error_Msg_Node_2 := Entity (Name);
4115 Error_Msg_NE ("invisible selector& for &", N, Sel);
4118 Error_Msg_Node_2 := First_Subtype (Prefix_Type);
4119 Error_Msg_NE ("invisible selector& for }", N, Sel);
4125 Set_Is_Overloaded (N, Is_Overloaded (Sel));
4130 Error_Msg_NE ("invalid prefix in selected component&", N, Sel);
4133 -- If N still has no type, the component is not defined in the prefix
4135 if Etype (N) = Any_Type then
4137 if Is_Single_Concurrent_Object then
4138 Error_Msg_Node_2 := Entity (Name);
4139 Error_Msg_NE ("no selector& for&", N, Sel);
4141 Check_Misspelled_Selector (Type_To_Use, Sel);
4143 elsif Is_Generic_Type (Prefix_Type)
4144 and then Ekind (Prefix_Type) = E_Record_Type_With_Private
4145 and then Prefix_Type /= Etype (Prefix_Type)
4146 and then Is_Record_Type (Etype (Prefix_Type))
4148 -- If this is a derived formal type, the parent may have
4149 -- different visibility at this point. Try for an inherited
4150 -- component before reporting an error.
4152 Set_Etype (Prefix (N), Etype (Prefix_Type));
4153 Analyze_Selected_Component (N);
4156 -- Similarly, if this is the actual for a formal derived type, the
4157 -- component inherited from the generic parent may not be visible
4158 -- in the actual, but the selected component is legal.
4160 elsif Ekind (Prefix_Type) = E_Record_Subtype_With_Private
4161 and then Is_Generic_Actual_Type (Prefix_Type)
4162 and then Present (Full_View (Prefix_Type))
4165 Find_Component_In_Instance
4166 (Generic_Parent_Type (Parent (Prefix_Type)));
4169 -- Finally, the formal and the actual may be private extensions,
4170 -- but the generic is declared in a child unit of the parent, and
4171 -- an additional step is needed to retrieve the proper scope.
4174 and then Present (Parent_Subtype (Etype (Base_Type (Prefix_Type))))
4176 Find_Component_In_Instance
4177 (Parent_Subtype (Etype (Base_Type (Prefix_Type))));
4180 -- Component not found, specialize error message when appropriate
4183 if Ekind (Prefix_Type) = E_Record_Subtype then
4185 -- Check whether this is a component of the base type which
4186 -- is absent from a statically constrained subtype. This will
4187 -- raise constraint error at run time, but is not a compile-
4188 -- time error. When the selector is illegal for base type as
4189 -- well fall through and generate a compilation error anyway.
4191 Comp := First_Component (Base_Type (Prefix_Type));
4192 while Present (Comp) loop
4193 if Chars (Comp) = Chars (Sel)
4194 and then Is_Visible_Component (Comp)
4196 Set_Entity_With_Style_Check (Sel, Comp);
4197 Generate_Reference (Comp, Sel);
4198 Set_Etype (Sel, Etype (Comp));
4199 Set_Etype (N, Etype (Comp));
4201 -- Emit appropriate message. Gigi will replace the
4202 -- node subsequently with the appropriate Raise.
4204 Apply_Compile_Time_Constraint_Error
4205 (N, "component not present in }?",
4206 CE_Discriminant_Check_Failed,
4207 Ent => Prefix_Type, Rep => False);
4208 Set_Raises_Constraint_Error (N);
4212 Next_Component (Comp);
4217 Error_Msg_Node_2 := First_Subtype (Prefix_Type);
4218 Error_Msg_NE ("no selector& for}", N, Sel);
4220 Check_Misspelled_Selector (Type_To_Use, Sel);
4223 Set_Entity (Sel, Any_Id);
4224 Set_Etype (Sel, Any_Type);
4226 end Analyze_Selected_Component;
4228 ---------------------------
4229 -- Analyze_Short_Circuit --
4230 ---------------------------
4232 procedure Analyze_Short_Circuit (N : Node_Id) is
4233 L : constant Node_Id := Left_Opnd (N);
4234 R : constant Node_Id := Right_Opnd (N);
4239 Analyze_Expression (L);
4240 Analyze_Expression (R);
4241 Set_Etype (N, Any_Type);
4243 if not Is_Overloaded (L) then
4244 if Root_Type (Etype (L)) = Standard_Boolean
4245 and then Has_Compatible_Type (R, Etype (L))
4247 Add_One_Interp (N, Etype (L), Etype (L));
4251 Get_First_Interp (L, Ind, It);
4252 while Present (It.Typ) loop
4253 if Root_Type (It.Typ) = Standard_Boolean
4254 and then Has_Compatible_Type (R, It.Typ)
4256 Add_One_Interp (N, It.Typ, It.Typ);
4259 Get_Next_Interp (Ind, It);
4263 -- Here we have failed to find an interpretation. Clearly we know that
4264 -- it is not the case that both operands can have an interpretation of
4265 -- Boolean, but this is by far the most likely intended interpretation.
4266 -- So we simply resolve both operands as Booleans, and at least one of
4267 -- these resolutions will generate an error message, and we do not need
4268 -- to give another error message on the short circuit operation itself.
4270 if Etype (N) = Any_Type then
4271 Resolve (L, Standard_Boolean);
4272 Resolve (R, Standard_Boolean);
4273 Set_Etype (N, Standard_Boolean);
4275 end Analyze_Short_Circuit;
4281 procedure Analyze_Slice (N : Node_Id) is
4282 P : constant Node_Id := Prefix (N);
4283 D : constant Node_Id := Discrete_Range (N);
4284 Array_Type : Entity_Id;
4286 procedure Analyze_Overloaded_Slice;
4287 -- If the prefix is overloaded, select those interpretations that
4288 -- yield a one-dimensional array type.
4290 ------------------------------
4291 -- Analyze_Overloaded_Slice --
4292 ------------------------------
4294 procedure Analyze_Overloaded_Slice is
4300 Set_Etype (N, Any_Type);
4302 Get_First_Interp (P, I, It);
4303 while Present (It.Nam) loop
4306 if Is_Access_Type (Typ) then
4307 Typ := Designated_Type (Typ);
4308 Error_Msg_NW (Warn_On_Dereference, "?implicit dereference", N);
4311 if Is_Array_Type (Typ)
4312 and then Number_Dimensions (Typ) = 1
4313 and then Has_Compatible_Type (D, Etype (First_Index (Typ)))
4315 Add_One_Interp (N, Typ, Typ);
4318 Get_Next_Interp (I, It);
4321 if Etype (N) = Any_Type then
4322 Error_Msg_N ("expect array type in prefix of slice", N);
4324 end Analyze_Overloaded_Slice;
4326 -- Start of processing for Analyze_Slice
4329 Mark_Non_ALFA_Subprogram;
4330 Check_SPARK_Restriction ("slice is not allowed", N);
4335 if Is_Overloaded (P) then
4336 Analyze_Overloaded_Slice;
4339 Array_Type := Etype (P);
4340 Set_Etype (N, Any_Type);
4342 if Is_Access_Type (Array_Type) then
4343 Array_Type := Designated_Type (Array_Type);
4344 Error_Msg_NW (Warn_On_Dereference, "?implicit dereference", N);
4347 if not Is_Array_Type (Array_Type) then
4348 Wrong_Type (P, Any_Array);
4350 elsif Number_Dimensions (Array_Type) > 1 then
4352 ("type is not one-dimensional array in slice prefix", N);
4355 Has_Compatible_Type (D, Etype (First_Index (Array_Type)))
4357 Wrong_Type (D, Etype (First_Index (Array_Type)));
4360 Set_Etype (N, Array_Type);
4365 -----------------------------
4366 -- Analyze_Type_Conversion --
4367 -----------------------------
4369 procedure Analyze_Type_Conversion (N : Node_Id) is
4370 Expr : constant Node_Id := Expression (N);
4374 Mark_Non_ALFA_Subprogram;
4376 -- If Conversion_OK is set, then the Etype is already set, and the
4377 -- only processing required is to analyze the expression. This is
4378 -- used to construct certain "illegal" conversions which are not
4379 -- allowed by Ada semantics, but can be handled OK by Gigi, see
4380 -- Sinfo for further details.
4382 if Conversion_OK (N) then
4387 -- Otherwise full type analysis is required, as well as some semantic
4388 -- checks to make sure the argument of the conversion is appropriate.
4390 Find_Type (Subtype_Mark (N));
4391 T := Entity (Subtype_Mark (N));
4393 Check_Fully_Declared (T, N);
4394 Analyze_Expression (Expr);
4395 Validate_Remote_Type_Type_Conversion (N);
4397 -- Only remaining step is validity checks on the argument. These
4398 -- are skipped if the conversion does not come from the source.
4400 if not Comes_From_Source (N) then
4403 -- If there was an error in a generic unit, no need to replicate the
4404 -- error message. Conversely, constant-folding in the generic may
4405 -- transform the argument of a conversion into a string literal, which
4406 -- is legal. Therefore the following tests are not performed in an
4409 elsif In_Instance then
4412 elsif Nkind (Expr) = N_Null then
4413 Error_Msg_N ("argument of conversion cannot be null", N);
4414 Error_Msg_N ("\use qualified expression instead", N);
4415 Set_Etype (N, Any_Type);
4417 elsif Nkind (Expr) = N_Aggregate then
4418 Error_Msg_N ("argument of conversion cannot be aggregate", N);
4419 Error_Msg_N ("\use qualified expression instead", N);
4421 elsif Nkind (Expr) = N_Allocator then
4422 Error_Msg_N ("argument of conversion cannot be an allocator", N);
4423 Error_Msg_N ("\use qualified expression instead", N);
4425 elsif Nkind (Expr) = N_String_Literal then
4426 Error_Msg_N ("argument of conversion cannot be string literal", N);
4427 Error_Msg_N ("\use qualified expression instead", N);
4429 elsif Nkind (Expr) = N_Character_Literal then
4430 if Ada_Version = Ada_83 then
4433 Error_Msg_N ("argument of conversion cannot be character literal",
4435 Error_Msg_N ("\use qualified expression instead", N);
4438 elsif Nkind (Expr) = N_Attribute_Reference
4440 (Attribute_Name (Expr) = Name_Access or else
4441 Attribute_Name (Expr) = Name_Unchecked_Access or else
4442 Attribute_Name (Expr) = Name_Unrestricted_Access)
4444 Error_Msg_N ("argument of conversion cannot be access", N);
4445 Error_Msg_N ("\use qualified expression instead", N);
4447 end Analyze_Type_Conversion;
4449 ----------------------
4450 -- Analyze_Unary_Op --
4451 ----------------------
4453 procedure Analyze_Unary_Op (N : Node_Id) is
4454 R : constant Node_Id := Right_Opnd (N);
4455 Op_Id : Entity_Id := Entity (N);
4458 Set_Etype (N, Any_Type);
4459 Candidate_Type := Empty;
4461 Analyze_Expression (R);
4463 if Present (Op_Id) then
4464 if Ekind (Op_Id) = E_Operator then
4465 Find_Unary_Types (R, Op_Id, N);
4467 Add_One_Interp (N, Op_Id, Etype (Op_Id));
4471 Op_Id := Get_Name_Entity_Id (Chars (N));
4472 while Present (Op_Id) loop
4473 if Ekind (Op_Id) = E_Operator then
4474 if No (Next_Entity (First_Entity (Op_Id))) then
4475 Find_Unary_Types (R, Op_Id, N);
4478 elsif Is_Overloadable (Op_Id) then
4479 Analyze_User_Defined_Unary_Op (N, Op_Id);
4482 Op_Id := Homonym (Op_Id);
4487 end Analyze_Unary_Op;
4489 ----------------------------------
4490 -- Analyze_Unchecked_Expression --
4491 ----------------------------------
4493 procedure Analyze_Unchecked_Expression (N : Node_Id) is
4495 Analyze (Expression (N), Suppress => All_Checks);
4496 Set_Etype (N, Etype (Expression (N)));
4497 Save_Interps (Expression (N), N);
4498 end Analyze_Unchecked_Expression;
4500 ---------------------------------------
4501 -- Analyze_Unchecked_Type_Conversion --
4502 ---------------------------------------
4504 procedure Analyze_Unchecked_Type_Conversion (N : Node_Id) is
4506 Mark_Non_ALFA_Subprogram;
4507 Find_Type (Subtype_Mark (N));
4508 Analyze_Expression (Expression (N));
4509 Set_Etype (N, Entity (Subtype_Mark (N)));
4510 end Analyze_Unchecked_Type_Conversion;
4512 ------------------------------------
4513 -- Analyze_User_Defined_Binary_Op --
4514 ------------------------------------
4516 procedure Analyze_User_Defined_Binary_Op
4521 -- Only do analysis if the operator Comes_From_Source, since otherwise
4522 -- the operator was generated by the expander, and all such operators
4523 -- always refer to the operators in package Standard.
4525 if Comes_From_Source (N) then
4527 F1 : constant Entity_Id := First_Formal (Op_Id);
4528 F2 : constant Entity_Id := Next_Formal (F1);
4531 -- Verify that Op_Id is a visible binary function. Note that since
4532 -- we know Op_Id is overloaded, potentially use visible means use
4533 -- visible for sure (RM 9.4(11)).
4535 if Ekind (Op_Id) = E_Function
4536 and then Present (F2)
4537 and then (Is_Immediately_Visible (Op_Id)
4538 or else Is_Potentially_Use_Visible (Op_Id))
4539 and then Has_Compatible_Type (Left_Opnd (N), Etype (F1))
4540 and then Has_Compatible_Type (Right_Opnd (N), Etype (F2))
4542 Add_One_Interp (N, Op_Id, Etype (Op_Id));
4544 -- If the left operand is overloaded, indicate that the
4545 -- current type is a viable candidate. This is redundant
4546 -- in most cases, but for equality and comparison operators
4547 -- where the context does not impose a type on the operands,
4548 -- setting the proper type is necessary to avoid subsequent
4549 -- ambiguities during resolution, when both user-defined and
4550 -- predefined operators may be candidates.
4552 if Is_Overloaded (Left_Opnd (N)) then
4553 Set_Etype (Left_Opnd (N), Etype (F1));
4556 if Debug_Flag_E then
4557 Write_Str ("user defined operator ");
4558 Write_Name (Chars (Op_Id));
4559 Write_Str (" on node ");
4560 Write_Int (Int (N));
4566 end Analyze_User_Defined_Binary_Op;
4568 -----------------------------------
4569 -- Analyze_User_Defined_Unary_Op --
4570 -----------------------------------
4572 procedure Analyze_User_Defined_Unary_Op
4577 -- Only do analysis if the operator Comes_From_Source, since otherwise
4578 -- the operator was generated by the expander, and all such operators
4579 -- always refer to the operators in package Standard.
4581 if Comes_From_Source (N) then
4583 F : constant Entity_Id := First_Formal (Op_Id);
4586 -- Verify that Op_Id is a visible unary function. Note that since
4587 -- we know Op_Id is overloaded, potentially use visible means use
4588 -- visible for sure (RM 9.4(11)).
4590 if Ekind (Op_Id) = E_Function
4591 and then No (Next_Formal (F))
4592 and then (Is_Immediately_Visible (Op_Id)
4593 or else Is_Potentially_Use_Visible (Op_Id))
4594 and then Has_Compatible_Type (Right_Opnd (N), Etype (F))
4596 Add_One_Interp (N, Op_Id, Etype (Op_Id));
4600 end Analyze_User_Defined_Unary_Op;
4602 ---------------------------
4603 -- Check_Arithmetic_Pair --
4604 ---------------------------
4606 procedure Check_Arithmetic_Pair
4607 (T1, T2 : Entity_Id;
4611 Op_Name : constant Name_Id := Chars (Op_Id);
4613 function Has_Fixed_Op (Typ : Entity_Id; Op : Entity_Id) return Boolean;
4614 -- Check whether the fixed-point type Typ has a user-defined operator
4615 -- (multiplication or division) that should hide the corresponding
4616 -- predefined operator. Used to implement Ada 2005 AI-264, to make
4617 -- such operators more visible and therefore useful.
4619 -- If the name of the operation is an expanded name with prefix
4620 -- Standard, the predefined universal fixed operator is available,
4621 -- as specified by AI-420 (RM 4.5.5 (19.1/2)).
4623 function Specific_Type (T1, T2 : Entity_Id) return Entity_Id;
4624 -- Get specific type (i.e. non-universal type if there is one)
4630 function Has_Fixed_Op (Typ : Entity_Id; Op : Entity_Id) return Boolean is
4631 Bas : constant Entity_Id := Base_Type (Typ);
4637 -- If the universal_fixed operation is given explicitly the rule
4638 -- concerning primitive operations of the type do not apply.
4640 if Nkind (N) = N_Function_Call
4641 and then Nkind (Name (N)) = N_Expanded_Name
4642 and then Entity (Prefix (Name (N))) = Standard_Standard
4647 -- The operation is treated as primitive if it is declared in the
4648 -- same scope as the type, and therefore on the same entity chain.
4650 Ent := Next_Entity (Typ);
4651 while Present (Ent) loop
4652 if Chars (Ent) = Chars (Op) then
4653 F1 := First_Formal (Ent);
4654 F2 := Next_Formal (F1);
4656 -- The operation counts as primitive if either operand or
4657 -- result are of the given base type, and both operands are
4658 -- fixed point types.
4660 if (Base_Type (Etype (F1)) = Bas
4661 and then Is_Fixed_Point_Type (Etype (F2)))
4664 (Base_Type (Etype (F2)) = Bas
4665 and then Is_Fixed_Point_Type (Etype (F1)))
4668 (Base_Type (Etype (Ent)) = Bas
4669 and then Is_Fixed_Point_Type (Etype (F1))
4670 and then Is_Fixed_Point_Type (Etype (F2)))
4686 function Specific_Type (T1, T2 : Entity_Id) return Entity_Id is
4688 if T1 = Universal_Integer or else T1 = Universal_Real then
4689 return Base_Type (T2);
4691 return Base_Type (T1);
4695 -- Start of processing for Check_Arithmetic_Pair
4698 if Op_Name = Name_Op_Add or else Op_Name = Name_Op_Subtract then
4700 if Is_Numeric_Type (T1)
4701 and then Is_Numeric_Type (T2)
4702 and then (Covers (T1 => T1, T2 => T2)
4704 Covers (T1 => T2, T2 => T1))
4706 Add_One_Interp (N, Op_Id, Specific_Type (T1, T2));
4709 elsif Op_Name = Name_Op_Multiply or else Op_Name = Name_Op_Divide then
4711 if Is_Fixed_Point_Type (T1)
4712 and then (Is_Fixed_Point_Type (T2)
4713 or else T2 = Universal_Real)
4715 -- If Treat_Fixed_As_Integer is set then the Etype is already set
4716 -- and no further processing is required (this is the case of an
4717 -- operator constructed by Exp_Fixd for a fixed point operation)
4718 -- Otherwise add one interpretation with universal fixed result
4719 -- If the operator is given in functional notation, it comes
4720 -- from source and Fixed_As_Integer cannot apply.
4722 if (Nkind (N) not in N_Op
4723 or else not Treat_Fixed_As_Integer (N))
4725 (not Has_Fixed_Op (T1, Op_Id)
4726 or else Nkind (Parent (N)) = N_Type_Conversion)
4728 Add_One_Interp (N, Op_Id, Universal_Fixed);
4731 elsif Is_Fixed_Point_Type (T2)
4732 and then (Nkind (N) not in N_Op
4733 or else not Treat_Fixed_As_Integer (N))
4734 and then T1 = Universal_Real
4736 (not Has_Fixed_Op (T1, Op_Id)
4737 or else Nkind (Parent (N)) = N_Type_Conversion)
4739 Add_One_Interp (N, Op_Id, Universal_Fixed);
4741 elsif Is_Numeric_Type (T1)
4742 and then Is_Numeric_Type (T2)
4743 and then (Covers (T1 => T1, T2 => T2)
4745 Covers (T1 => T2, T2 => T1))
4747 Add_One_Interp (N, Op_Id, Specific_Type (T1, T2));
4749 elsif Is_Fixed_Point_Type (T1)
4750 and then (Base_Type (T2) = Base_Type (Standard_Integer)
4751 or else T2 = Universal_Integer)
4753 Add_One_Interp (N, Op_Id, T1);
4755 elsif T2 = Universal_Real
4756 and then Base_Type (T1) = Base_Type (Standard_Integer)
4757 and then Op_Name = Name_Op_Multiply
4759 Add_One_Interp (N, Op_Id, Any_Fixed);
4761 elsif T1 = Universal_Real
4762 and then Base_Type (T2) = Base_Type (Standard_Integer)
4764 Add_One_Interp (N, Op_Id, Any_Fixed);
4766 elsif Is_Fixed_Point_Type (T2)
4767 and then (Base_Type (T1) = Base_Type (Standard_Integer)
4768 or else T1 = Universal_Integer)
4769 and then Op_Name = Name_Op_Multiply
4771 Add_One_Interp (N, Op_Id, T2);
4773 elsif T1 = Universal_Real and then T2 = Universal_Integer then
4774 Add_One_Interp (N, Op_Id, T1);
4776 elsif T2 = Universal_Real
4777 and then T1 = Universal_Integer
4778 and then Op_Name = Name_Op_Multiply
4780 Add_One_Interp (N, Op_Id, T2);
4783 elsif Op_Name = Name_Op_Mod or else Op_Name = Name_Op_Rem then
4785 -- Note: The fixed-point operands case with Treat_Fixed_As_Integer
4786 -- set does not require any special processing, since the Etype is
4787 -- already set (case of operation constructed by Exp_Fixed).
4789 if Is_Integer_Type (T1)
4790 and then (Covers (T1 => T1, T2 => T2)
4792 Covers (T1 => T2, T2 => T1))
4794 Add_One_Interp (N, Op_Id, Specific_Type (T1, T2));
4797 elsif Op_Name = Name_Op_Expon then
4798 if Is_Numeric_Type (T1)
4799 and then not Is_Fixed_Point_Type (T1)
4800 and then (Base_Type (T2) = Base_Type (Standard_Integer)
4801 or else T2 = Universal_Integer)
4803 Add_One_Interp (N, Op_Id, Base_Type (T1));
4806 else pragma Assert (Nkind (N) in N_Op_Shift);
4808 -- If not one of the predefined operators, the node may be one
4809 -- of the intrinsic functions. Its kind is always specific, and
4810 -- we can use it directly, rather than the name of the operation.
4812 if Is_Integer_Type (T1)
4813 and then (Base_Type (T2) = Base_Type (Standard_Integer)
4814 or else T2 = Universal_Integer)
4816 Add_One_Interp (N, Op_Id, Base_Type (T1));
4819 end Check_Arithmetic_Pair;
4821 -------------------------------
4822 -- Check_Misspelled_Selector --
4823 -------------------------------
4825 procedure Check_Misspelled_Selector
4826 (Prefix : Entity_Id;
4829 Max_Suggestions : constant := 2;
4830 Nr_Of_Suggestions : Natural := 0;
4832 Suggestion_1 : Entity_Id := Empty;
4833 Suggestion_2 : Entity_Id := Empty;
4838 -- All the components of the prefix of selector Sel are matched
4839 -- against Sel and a count is maintained of possible misspellings.
4840 -- When at the end of the analysis there are one or two (not more!)
4841 -- possible misspellings, these misspellings will be suggested as
4842 -- possible correction.
4844 if not (Is_Private_Type (Prefix) or else Is_Record_Type (Prefix)) then
4846 -- Concurrent types should be handled as well ???
4851 Comp := First_Entity (Prefix);
4852 while Nr_Of_Suggestions <= Max_Suggestions and then Present (Comp) loop
4853 if Is_Visible_Component (Comp) then
4854 if Is_Bad_Spelling_Of (Chars (Comp), Chars (Sel)) then
4855 Nr_Of_Suggestions := Nr_Of_Suggestions + 1;
4857 case Nr_Of_Suggestions is
4858 when 1 => Suggestion_1 := Comp;
4859 when 2 => Suggestion_2 := Comp;
4860 when others => exit;
4865 Comp := Next_Entity (Comp);
4868 -- Report at most two suggestions
4870 if Nr_Of_Suggestions = 1 then
4871 Error_Msg_NE -- CODEFIX
4872 ("\possible misspelling of&", Sel, Suggestion_1);
4874 elsif Nr_Of_Suggestions = 2 then
4875 Error_Msg_Node_2 := Suggestion_2;
4876 Error_Msg_NE -- CODEFIX
4877 ("\possible misspelling of& or&", Sel, Suggestion_1);
4879 end Check_Misspelled_Selector;
4881 ----------------------
4882 -- Defined_In_Scope --
4883 ----------------------
4885 function Defined_In_Scope (T : Entity_Id; S : Entity_Id) return Boolean
4887 S1 : constant Entity_Id := Scope (Base_Type (T));
4890 or else (S1 = System_Aux_Id and then S = Scope (S1));
4891 end Defined_In_Scope;
4897 procedure Diagnose_Call (N : Node_Id; Nam : Node_Id) is
4903 Void_Interp_Seen : Boolean := False;
4906 pragma Warnings (Off, Boolean);
4909 if Ada_Version >= Ada_2005 then
4910 Actual := First_Actual (N);
4911 while Present (Actual) loop
4913 -- Ada 2005 (AI-50217): Post an error in case of premature
4914 -- usage of an entity from the limited view.
4916 if not Analyzed (Etype (Actual))
4917 and then From_With_Type (Etype (Actual))
4919 Error_Msg_Qual_Level := 1;
4921 ("missing with_clause for scope of imported type&",
4922 Actual, Etype (Actual));
4923 Error_Msg_Qual_Level := 0;
4926 Next_Actual (Actual);
4930 -- Analyze each candidate call again, with full error reporting
4934 ("no candidate interpretations match the actuals:!", Nam);
4935 Err_Mode := All_Errors_Mode;
4936 All_Errors_Mode := True;
4938 -- If this is a call to an operation of a concurrent type,
4939 -- the failed interpretations have been removed from the
4940 -- name. Recover them to provide full diagnostics.
4942 if Nkind (Parent (Nam)) = N_Selected_Component then
4943 Set_Entity (Nam, Empty);
4944 New_Nam := New_Copy_Tree (Parent (Nam));
4945 Set_Is_Overloaded (New_Nam, False);
4946 Set_Is_Overloaded (Selector_Name (New_Nam), False);
4947 Set_Parent (New_Nam, Parent (Parent (Nam)));
4948 Analyze_Selected_Component (New_Nam);
4949 Get_First_Interp (Selector_Name (New_Nam), X, It);
4951 Get_First_Interp (Nam, X, It);
4954 while Present (It.Nam) loop
4955 if Etype (It.Nam) = Standard_Void_Type then
4956 Void_Interp_Seen := True;
4959 Analyze_One_Call (N, It.Nam, True, Success);
4960 Get_Next_Interp (X, It);
4963 if Nkind (N) = N_Function_Call then
4964 Get_First_Interp (Nam, X, It);
4965 while Present (It.Nam) loop
4966 if Ekind_In (It.Nam, E_Function, E_Operator) then
4969 Get_Next_Interp (X, It);
4973 -- If all interpretations are procedures, this deserves a
4974 -- more precise message. Ditto if this appears as the prefix
4975 -- of a selected component, which may be a lexical error.
4978 ("\context requires function call, found procedure name", Nam);
4980 if Nkind (Parent (N)) = N_Selected_Component
4981 and then N = Prefix (Parent (N))
4983 Error_Msg_N -- CODEFIX
4984 ("\period should probably be semicolon", Parent (N));
4987 elsif Nkind (N) = N_Procedure_Call_Statement
4988 and then not Void_Interp_Seen
4991 "\function name found in procedure call", Nam);
4994 All_Errors_Mode := Err_Mode;
4997 ---------------------------
4998 -- Find_Arithmetic_Types --
4999 ---------------------------
5001 procedure Find_Arithmetic_Types
5006 Index1 : Interp_Index;
5007 Index2 : Interp_Index;
5011 procedure Check_Right_Argument (T : Entity_Id);
5012 -- Check right operand of operator
5014 --------------------------
5015 -- Check_Right_Argument --
5016 --------------------------
5018 procedure Check_Right_Argument (T : Entity_Id) is
5020 if not Is_Overloaded (R) then
5021 Check_Arithmetic_Pair (T, Etype (R), Op_Id, N);
5023 Get_First_Interp (R, Index2, It2);
5024 while Present (It2.Typ) loop
5025 Check_Arithmetic_Pair (T, It2.Typ, Op_Id, N);
5026 Get_Next_Interp (Index2, It2);
5029 end Check_Right_Argument;
5031 -- Start of processing for Find_Arithmetic_Types
5034 if not Is_Overloaded (L) then
5035 Check_Right_Argument (Etype (L));
5038 Get_First_Interp (L, Index1, It1);
5039 while Present (It1.Typ) loop
5040 Check_Right_Argument (It1.Typ);
5041 Get_Next_Interp (Index1, It1);
5045 end Find_Arithmetic_Types;
5047 ------------------------
5048 -- Find_Boolean_Types --
5049 ------------------------
5051 procedure Find_Boolean_Types
5056 Index : Interp_Index;
5059 procedure Check_Numeric_Argument (T : Entity_Id);
5060 -- Special case for logical operations one of whose operands is an
5061 -- integer literal. If both are literal the result is any modular type.
5063 ----------------------------
5064 -- Check_Numeric_Argument --
5065 ----------------------------
5067 procedure Check_Numeric_Argument (T : Entity_Id) is
5069 if T = Universal_Integer then
5070 Add_One_Interp (N, Op_Id, Any_Modular);
5072 elsif Is_Modular_Integer_Type (T) then
5073 Add_One_Interp (N, Op_Id, T);
5075 end Check_Numeric_Argument;
5077 -- Start of processing for Find_Boolean_Types
5080 if not Is_Overloaded (L) then
5081 if Etype (L) = Universal_Integer
5082 or else Etype (L) = Any_Modular
5084 if not Is_Overloaded (R) then
5085 Check_Numeric_Argument (Etype (R));
5088 Get_First_Interp (R, Index, It);
5089 while Present (It.Typ) loop
5090 Check_Numeric_Argument (It.Typ);
5091 Get_Next_Interp (Index, It);
5095 -- If operands are aggregates, we must assume that they may be
5096 -- boolean arrays, and leave disambiguation for the second pass.
5097 -- If only one is an aggregate, verify that the other one has an
5098 -- interpretation as a boolean array
5100 elsif Nkind (L) = N_Aggregate then
5101 if Nkind (R) = N_Aggregate then
5102 Add_One_Interp (N, Op_Id, Etype (L));
5104 elsif not Is_Overloaded (R) then
5105 if Valid_Boolean_Arg (Etype (R)) then
5106 Add_One_Interp (N, Op_Id, Etype (R));
5110 Get_First_Interp (R, Index, It);
5111 while Present (It.Typ) loop
5112 if Valid_Boolean_Arg (It.Typ) then
5113 Add_One_Interp (N, Op_Id, It.Typ);
5116 Get_Next_Interp (Index, It);
5120 elsif Valid_Boolean_Arg (Etype (L))
5121 and then Has_Compatible_Type (R, Etype (L))
5123 Add_One_Interp (N, Op_Id, Etype (L));
5127 Get_First_Interp (L, Index, It);
5128 while Present (It.Typ) loop
5129 if Valid_Boolean_Arg (It.Typ)
5130 and then Has_Compatible_Type (R, It.Typ)
5132 Add_One_Interp (N, Op_Id, It.Typ);
5135 Get_Next_Interp (Index, It);
5138 end Find_Boolean_Types;
5140 ---------------------------
5141 -- Find_Comparison_Types --
5142 ---------------------------
5144 procedure Find_Comparison_Types
5149 Index : Interp_Index;
5151 Found : Boolean := False;
5154 Scop : Entity_Id := Empty;
5156 procedure Try_One_Interp (T1 : Entity_Id);
5157 -- Routine to try one proposed interpretation. Note that the context
5158 -- of the operator plays no role in resolving the arguments, so that
5159 -- if there is more than one interpretation of the operands that is
5160 -- compatible with comparison, the operation is ambiguous.
5162 --------------------
5163 -- Try_One_Interp --
5164 --------------------
5166 procedure Try_One_Interp (T1 : Entity_Id) is
5169 -- If the operator is an expanded name, then the type of the operand
5170 -- must be defined in the corresponding scope. If the type is
5171 -- universal, the context will impose the correct type.
5174 and then not Defined_In_Scope (T1, Scop)
5175 and then T1 /= Universal_Integer
5176 and then T1 /= Universal_Real
5177 and then T1 /= Any_String
5178 and then T1 /= Any_Composite
5183 if Valid_Comparison_Arg (T1)
5184 and then Has_Compatible_Type (R, T1)
5187 and then Base_Type (T1) /= Base_Type (T_F)
5189 It := Disambiguate (L, I_F, Index, Any_Type);
5191 if It = No_Interp then
5192 Ambiguous_Operands (N);
5193 Set_Etype (L, Any_Type);
5207 Find_Non_Universal_Interpretations (N, R, Op_Id, T1);
5212 -- Start of processing for Find_Comparison_Types
5215 -- If left operand is aggregate, the right operand has to
5216 -- provide a usable type for it.
5218 if Nkind (L) = N_Aggregate
5219 and then Nkind (R) /= N_Aggregate
5221 Find_Comparison_Types (L => R, R => L, Op_Id => Op_Id, N => N);
5225 if Nkind (N) = N_Function_Call
5226 and then Nkind (Name (N)) = N_Expanded_Name
5228 Scop := Entity (Prefix (Name (N)));
5230 -- The prefix may be a package renaming, and the subsequent test
5231 -- requires the original package.
5233 if Ekind (Scop) = E_Package
5234 and then Present (Renamed_Entity (Scop))
5236 Scop := Renamed_Entity (Scop);
5237 Set_Entity (Prefix (Name (N)), Scop);
5241 if not Is_Overloaded (L) then
5242 Try_One_Interp (Etype (L));
5245 Get_First_Interp (L, Index, It);
5246 while Present (It.Typ) loop
5247 Try_One_Interp (It.Typ);
5248 Get_Next_Interp (Index, It);
5251 end Find_Comparison_Types;
5253 ----------------------------------------
5254 -- Find_Non_Universal_Interpretations --
5255 ----------------------------------------
5257 procedure Find_Non_Universal_Interpretations
5263 Index : Interp_Index;
5267 if T1 = Universal_Integer
5268 or else T1 = Universal_Real
5270 if not Is_Overloaded (R) then
5272 (N, Op_Id, Standard_Boolean, Base_Type (Etype (R)));
5274 Get_First_Interp (R, Index, It);
5275 while Present (It.Typ) loop
5276 if Covers (It.Typ, T1) then
5278 (N, Op_Id, Standard_Boolean, Base_Type (It.Typ));
5281 Get_Next_Interp (Index, It);
5285 Add_One_Interp (N, Op_Id, Standard_Boolean, Base_Type (T1));
5287 end Find_Non_Universal_Interpretations;
5289 ------------------------------
5290 -- Find_Concatenation_Types --
5291 ------------------------------
5293 procedure Find_Concatenation_Types
5298 Op_Type : constant Entity_Id := Etype (Op_Id);
5301 if Is_Array_Type (Op_Type)
5302 and then not Is_Limited_Type (Op_Type)
5304 and then (Has_Compatible_Type (L, Op_Type)
5306 Has_Compatible_Type (L, Component_Type (Op_Type)))
5308 and then (Has_Compatible_Type (R, Op_Type)
5310 Has_Compatible_Type (R, Component_Type (Op_Type)))
5312 Add_One_Interp (N, Op_Id, Op_Type);
5314 end Find_Concatenation_Types;
5316 -------------------------
5317 -- Find_Equality_Types --
5318 -------------------------
5320 procedure Find_Equality_Types
5325 Index : Interp_Index;
5327 Found : Boolean := False;
5330 Scop : Entity_Id := Empty;
5332 procedure Try_One_Interp (T1 : Entity_Id);
5333 -- The context of the equality operator plays no role in resolving the
5334 -- arguments, so that if there is more than one interpretation of the
5335 -- operands that is compatible with equality, the construct is ambiguous
5336 -- and an error can be emitted now, after trying to disambiguate, i.e.
5337 -- applying preference rules.
5339 --------------------
5340 -- Try_One_Interp --
5341 --------------------
5343 procedure Try_One_Interp (T1 : Entity_Id) is
5344 Bas : constant Entity_Id := Base_Type (T1);
5347 -- If the operator is an expanded name, then the type of the operand
5348 -- must be defined in the corresponding scope. If the type is
5349 -- universal, the context will impose the correct type. An anonymous
5350 -- type for a 'Access reference is also universal in this sense, as
5351 -- the actual type is obtained from context.
5352 -- In Ada 2005, the equality operator for anonymous access types
5353 -- is declared in Standard, and preference rules apply to it.
5355 if Present (Scop) then
5356 if Defined_In_Scope (T1, Scop)
5357 or else T1 = Universal_Integer
5358 or else T1 = Universal_Real
5359 or else T1 = Any_Access
5360 or else T1 = Any_String
5361 or else T1 = Any_Composite
5362 or else (Ekind (T1) = E_Access_Subprogram_Type
5363 and then not Comes_From_Source (T1))
5367 elsif Ekind (T1) = E_Anonymous_Access_Type
5368 and then Scop = Standard_Standard
5373 -- The scope does not contain an operator for the type
5378 -- If we have infix notation, the operator must be usable.
5379 -- Within an instance, if the type is already established we
5380 -- know it is correct.
5381 -- In Ada 2005, the equality on anonymous access types is declared
5382 -- in Standard, and is always visible.
5384 elsif In_Open_Scopes (Scope (Bas))
5385 or else Is_Potentially_Use_Visible (Bas)
5386 or else In_Use (Bas)
5387 or else (In_Use (Scope (Bas))
5388 and then not Is_Hidden (Bas))
5389 or else (In_Instance
5390 and then First_Subtype (T1) = First_Subtype (Etype (R)))
5391 or else Ekind (T1) = E_Anonymous_Access_Type
5396 -- Save candidate type for subsequent error message, if any
5398 if not Is_Limited_Type (T1) then
5399 Candidate_Type := T1;
5405 -- Ada 2005 (AI-230): Keep restriction imposed by Ada 83 and 95:
5406 -- Do not allow anonymous access types in equality operators.
5408 if Ada_Version < Ada_2005
5409 and then Ekind (T1) = E_Anonymous_Access_Type
5414 if T1 /= Standard_Void_Type
5415 and then not Is_Limited_Type (T1)
5416 and then not Is_Limited_Composite (T1)
5417 and then Has_Compatible_Type (R, T1)
5420 and then Base_Type (T1) /= Base_Type (T_F)
5422 It := Disambiguate (L, I_F, Index, Any_Type);
5424 if It = No_Interp then
5425 Ambiguous_Operands (N);
5426 Set_Etype (L, Any_Type);
5439 if not Analyzed (L) then
5443 Find_Non_Universal_Interpretations (N, R, Op_Id, T1);
5445 -- Case of operator was not visible, Etype still set to Any_Type
5447 if Etype (N) = Any_Type then
5451 elsif Scop = Standard_Standard
5452 and then Ekind (T1) = E_Anonymous_Access_Type
5458 -- Start of processing for Find_Equality_Types
5461 -- If left operand is aggregate, the right operand has to
5462 -- provide a usable type for it.
5464 if Nkind (L) = N_Aggregate
5465 and then Nkind (R) /= N_Aggregate
5467 Find_Equality_Types (L => R, R => L, Op_Id => Op_Id, N => N);
5471 if Nkind (N) = N_Function_Call
5472 and then Nkind (Name (N)) = N_Expanded_Name
5474 Scop := Entity (Prefix (Name (N)));
5476 -- The prefix may be a package renaming, and the subsequent test
5477 -- requires the original package.
5479 if Ekind (Scop) = E_Package
5480 and then Present (Renamed_Entity (Scop))
5482 Scop := Renamed_Entity (Scop);
5483 Set_Entity (Prefix (Name (N)), Scop);
5487 if not Is_Overloaded (L) then
5488 Try_One_Interp (Etype (L));
5491 Get_First_Interp (L, Index, It);
5492 while Present (It.Typ) loop
5493 Try_One_Interp (It.Typ);
5494 Get_Next_Interp (Index, It);
5497 end Find_Equality_Types;
5499 -------------------------
5500 -- Find_Negation_Types --
5501 -------------------------
5503 procedure Find_Negation_Types
5508 Index : Interp_Index;
5512 if not Is_Overloaded (R) then
5513 if Etype (R) = Universal_Integer then
5514 Add_One_Interp (N, Op_Id, Any_Modular);
5515 elsif Valid_Boolean_Arg (Etype (R)) then
5516 Add_One_Interp (N, Op_Id, Etype (R));
5520 Get_First_Interp (R, Index, It);
5521 while Present (It.Typ) loop
5522 if Valid_Boolean_Arg (It.Typ) then
5523 Add_One_Interp (N, Op_Id, It.Typ);
5526 Get_Next_Interp (Index, It);
5529 end Find_Negation_Types;
5531 ------------------------------
5532 -- Find_Primitive_Operation --
5533 ------------------------------
5535 function Find_Primitive_Operation (N : Node_Id) return Boolean is
5536 Obj : constant Node_Id := Prefix (N);
5537 Op : constant Node_Id := Selector_Name (N);
5544 Set_Etype (Op, Any_Type);
5546 if Is_Access_Type (Etype (Obj)) then
5547 Typ := Designated_Type (Etype (Obj));
5552 if Is_Class_Wide_Type (Typ) then
5553 Typ := Root_Type (Typ);
5556 Prims := Primitive_Operations (Typ);
5558 Prim := First_Elmt (Prims);
5559 while Present (Prim) loop
5560 if Chars (Node (Prim)) = Chars (Op) then
5561 Add_One_Interp (Op, Node (Prim), Etype (Node (Prim)));
5562 Set_Etype (N, Etype (Node (Prim)));
5568 -- Now look for class-wide operations of the type or any of its
5569 -- ancestors by iterating over the homonyms of the selector.
5572 Cls_Type : constant Entity_Id := Class_Wide_Type (Typ);
5576 Hom := Current_Entity (Op);
5577 while Present (Hom) loop
5578 if (Ekind (Hom) = E_Procedure
5580 Ekind (Hom) = E_Function)
5581 and then Scope (Hom) = Scope (Typ)
5582 and then Present (First_Formal (Hom))
5584 (Base_Type (Etype (First_Formal (Hom))) = Cls_Type
5586 (Is_Access_Type (Etype (First_Formal (Hom)))
5588 Ekind (Etype (First_Formal (Hom))) =
5589 E_Anonymous_Access_Type
5592 (Designated_Type (Etype (First_Formal (Hom)))) =
5595 Add_One_Interp (Op, Hom, Etype (Hom));
5596 Set_Etype (N, Etype (Hom));
5599 Hom := Homonym (Hom);
5603 return Etype (Op) /= Any_Type;
5604 end Find_Primitive_Operation;
5606 ----------------------
5607 -- Find_Unary_Types --
5608 ----------------------
5610 procedure Find_Unary_Types
5615 Index : Interp_Index;
5619 if not Is_Overloaded (R) then
5620 if Is_Numeric_Type (Etype (R)) then
5621 Add_One_Interp (N, Op_Id, Base_Type (Etype (R)));
5625 Get_First_Interp (R, Index, It);
5626 while Present (It.Typ) loop
5627 if Is_Numeric_Type (It.Typ) then
5628 Add_One_Interp (N, Op_Id, Base_Type (It.Typ));
5631 Get_Next_Interp (Index, It);
5634 end Find_Unary_Types;
5640 function Junk_Operand (N : Node_Id) return Boolean is
5644 if Error_Posted (N) then
5648 -- Get entity to be tested
5650 if Is_Entity_Name (N)
5651 and then Present (Entity (N))
5655 -- An odd case, a procedure name gets converted to a very peculiar
5656 -- function call, and here is where we detect this happening.
5658 elsif Nkind (N) = N_Function_Call
5659 and then Is_Entity_Name (Name (N))
5660 and then Present (Entity (Name (N)))
5664 -- Another odd case, there are at least some cases of selected
5665 -- components where the selected component is not marked as having
5666 -- an entity, even though the selector does have an entity
5668 elsif Nkind (N) = N_Selected_Component
5669 and then Present (Entity (Selector_Name (N)))
5671 Enode := Selector_Name (N);
5677 -- Now test the entity we got to see if it is a bad case
5679 case Ekind (Entity (Enode)) is
5683 ("package name cannot be used as operand", Enode);
5685 when Generic_Unit_Kind =>
5687 ("generic unit name cannot be used as operand", Enode);
5691 ("subtype name cannot be used as operand", Enode);
5695 ("entry name cannot be used as operand", Enode);
5699 ("procedure name cannot be used as operand", Enode);
5703 ("exception name cannot be used as operand", Enode);
5705 when E_Block | E_Label | E_Loop =>
5707 ("label name cannot be used as operand", Enode);
5717 --------------------
5718 -- Operator_Check --
5719 --------------------
5721 procedure Operator_Check (N : Node_Id) is
5723 Remove_Abstract_Operations (N);
5725 -- Test for case of no interpretation found for operator
5727 if Etype (N) = Any_Type then
5731 Op_Id : Entity_Id := Empty;
5734 R := Right_Opnd (N);
5736 if Nkind (N) in N_Binary_Op then
5742 -- If either operand has no type, then don't complain further,
5743 -- since this simply means that we have a propagated error.
5746 or else Etype (R) = Any_Type
5747 or else (Nkind (N) in N_Binary_Op and then Etype (L) = Any_Type)
5751 -- We explicitly check for the case of concatenation of component
5752 -- with component to avoid reporting spurious matching array types
5753 -- that might happen to be lurking in distant packages (such as
5754 -- run-time packages). This also prevents inconsistencies in the
5755 -- messages for certain ACVC B tests, which can vary depending on
5756 -- types declared in run-time interfaces. Another improvement when
5757 -- aggregates are present is to look for a well-typed operand.
5759 elsif Present (Candidate_Type)
5760 and then (Nkind (N) /= N_Op_Concat
5761 or else Is_Array_Type (Etype (L))
5762 or else Is_Array_Type (Etype (R)))
5764 if Nkind (N) = N_Op_Concat then
5765 if Etype (L) /= Any_Composite
5766 and then Is_Array_Type (Etype (L))
5768 Candidate_Type := Etype (L);
5770 elsif Etype (R) /= Any_Composite
5771 and then Is_Array_Type (Etype (R))
5773 Candidate_Type := Etype (R);
5777 Error_Msg_NE -- CODEFIX
5778 ("operator for} is not directly visible!",
5779 N, First_Subtype (Candidate_Type));
5782 U : constant Node_Id :=
5783 Cunit (Get_Source_Unit (Candidate_Type));
5785 if Unit_Is_Visible (U) then
5786 Error_Msg_N -- CODEFIX
5787 ("use clause would make operation legal!", N);
5789 Error_Msg_NE -- CODEFIX
5790 ("add with_clause and use_clause for&!",
5791 N, Defining_Entity (Unit (U)));
5796 -- If either operand is a junk operand (e.g. package name), then
5797 -- post appropriate error messages, but do not complain further.
5799 -- Note that the use of OR in this test instead of OR ELSE is
5800 -- quite deliberate, we may as well check both operands in the
5801 -- binary operator case.
5803 elsif Junk_Operand (R)
5804 or (Nkind (N) in N_Binary_Op and then Junk_Operand (L))
5808 -- If we have a logical operator, one of whose operands is
5809 -- Boolean, then we know that the other operand cannot resolve to
5810 -- Boolean (since we got no interpretations), but in that case we
5811 -- pretty much know that the other operand should be Boolean, so
5812 -- resolve it that way (generating an error)
5814 elsif Nkind_In (N, N_Op_And, N_Op_Or, N_Op_Xor) then
5815 if Etype (L) = Standard_Boolean then
5816 Resolve (R, Standard_Boolean);
5818 elsif Etype (R) = Standard_Boolean then
5819 Resolve (L, Standard_Boolean);
5823 -- For an arithmetic operator or comparison operator, if one
5824 -- of the operands is numeric, then we know the other operand
5825 -- is not the same numeric type. If it is a non-numeric type,
5826 -- then probably it is intended to match the other operand.
5828 elsif Nkind_In (N, N_Op_Add,
5834 Nkind_In (N, N_Op_Lt,
5840 if Is_Numeric_Type (Etype (L))
5841 and then not Is_Numeric_Type (Etype (R))
5843 Resolve (R, Etype (L));
5846 elsif Is_Numeric_Type (Etype (R))
5847 and then not Is_Numeric_Type (Etype (L))
5849 Resolve (L, Etype (R));
5853 -- Comparisons on A'Access are common enough to deserve a
5856 elsif Nkind_In (N, N_Op_Eq, N_Op_Ne)
5857 and then Ekind (Etype (L)) = E_Access_Attribute_Type
5858 and then Ekind (Etype (R)) = E_Access_Attribute_Type
5861 ("two access attributes cannot be compared directly", N);
5863 ("\use qualified expression for one of the operands",
5867 -- Another one for C programmers
5869 elsif Nkind (N) = N_Op_Concat
5870 and then Valid_Boolean_Arg (Etype (L))
5871 and then Valid_Boolean_Arg (Etype (R))
5873 Error_Msg_N ("invalid operands for concatenation", N);
5874 Error_Msg_N -- CODEFIX
5875 ("\maybe AND was meant", N);
5878 -- A special case for comparison of access parameter with null
5880 elsif Nkind (N) = N_Op_Eq
5881 and then Is_Entity_Name (L)
5882 and then Nkind (Parent (Entity (L))) = N_Parameter_Specification
5883 and then Nkind (Parameter_Type (Parent (Entity (L)))) =
5885 and then Nkind (R) = N_Null
5887 Error_Msg_N ("access parameter is not allowed to be null", L);
5888 Error_Msg_N ("\(call would raise Constraint_Error)", L);
5891 -- Another special case for exponentiation, where the right
5892 -- operand must be Natural, independently of the base.
5894 elsif Nkind (N) = N_Op_Expon
5895 and then Is_Numeric_Type (Etype (L))
5896 and then not Is_Overloaded (R)
5898 First_Subtype (Base_Type (Etype (R))) /= Standard_Integer
5899 and then Base_Type (Etype (R)) /= Universal_Integer
5902 ("exponent must be of type Natural, found}", R, Etype (R));
5906 -- If we fall through then just give general message. Note that in
5907 -- the following messages, if the operand is overloaded we choose
5908 -- an arbitrary type to complain about, but that is probably more
5909 -- useful than not giving a type at all.
5911 if Nkind (N) in N_Unary_Op then
5912 Error_Msg_Node_2 := Etype (R);
5913 Error_Msg_N ("operator& not defined for}", N);
5917 if Nkind (N) in N_Binary_Op then
5918 if not Is_Overloaded (L)
5919 and then not Is_Overloaded (R)
5920 and then Base_Type (Etype (L)) = Base_Type (Etype (R))
5922 Error_Msg_Node_2 := First_Subtype (Etype (R));
5923 Error_Msg_N ("there is no applicable operator& for}", N);
5926 -- Another attempt to find a fix: one of the candidate
5927 -- interpretations may not be use-visible. This has
5928 -- already been checked for predefined operators, so
5929 -- we examine only user-defined functions.
5931 Op_Id := Get_Name_Entity_Id (Chars (N));
5933 while Present (Op_Id) loop
5934 if Ekind (Op_Id) /= E_Operator
5935 and then Is_Overloadable (Op_Id)
5937 if not Is_Immediately_Visible (Op_Id)
5938 and then not In_Use (Scope (Op_Id))
5939 and then not Is_Abstract_Subprogram (Op_Id)
5940 and then not Is_Hidden (Op_Id)
5941 and then Ekind (Scope (Op_Id)) = E_Package
5944 (L, Etype (First_Formal (Op_Id)))
5946 (Next_Formal (First_Formal (Op_Id)))
5950 Etype (Next_Formal (First_Formal (Op_Id))))
5953 ("No legal interpretation for operator&", N);
5955 ("\use clause on& would make operation legal",
5961 Op_Id := Homonym (Op_Id);
5965 Error_Msg_N ("invalid operand types for operator&", N);
5967 if Nkind (N) /= N_Op_Concat then
5968 Error_Msg_NE ("\left operand has}!", N, Etype (L));
5969 Error_Msg_NE ("\right operand has}!", N, Etype (R));
5979 -----------------------------------------
5980 -- Process_Implicit_Dereference_Prefix --
5981 -----------------------------------------
5983 function Process_Implicit_Dereference_Prefix
5985 P : Entity_Id) return Entity_Id
5988 Typ : constant Entity_Id := Designated_Type (Etype (P));
5992 and then (Operating_Mode = Check_Semantics or else not Expander_Active)
5994 -- We create a dummy reference to E to ensure that the reference
5995 -- is not considered as part of an assignment (an implicit
5996 -- dereference can never assign to its prefix). The Comes_From_Source
5997 -- attribute needs to be propagated for accurate warnings.
5999 Ref := New_Reference_To (E, Sloc (P));
6000 Set_Comes_From_Source (Ref, Comes_From_Source (P));
6001 Generate_Reference (E, Ref);
6004 -- An implicit dereference is a legal occurrence of an
6005 -- incomplete type imported through a limited_with clause,
6006 -- if the full view is visible.
6008 if From_With_Type (Typ)
6009 and then not From_With_Type (Scope (Typ))
6011 (Is_Immediately_Visible (Scope (Typ))
6013 (Is_Child_Unit (Scope (Typ))
6014 and then Is_Visible_Child_Unit (Scope (Typ))))
6016 return Available_View (Typ);
6021 end Process_Implicit_Dereference_Prefix;
6023 --------------------------------
6024 -- Remove_Abstract_Operations --
6025 --------------------------------
6027 procedure Remove_Abstract_Operations (N : Node_Id) is
6028 Abstract_Op : Entity_Id := Empty;
6029 Address_Kludge : Boolean := False;
6033 -- AI-310: If overloaded, remove abstract non-dispatching operations. We
6034 -- activate this if either extensions are enabled, or if the abstract
6035 -- operation in question comes from a predefined file. This latter test
6036 -- allows us to use abstract to make operations invisible to users. In
6037 -- particular, if type Address is non-private and abstract subprograms
6038 -- are used to hide its operators, they will be truly hidden.
6040 type Operand_Position is (First_Op, Second_Op);
6041 Univ_Type : constant Entity_Id := Universal_Interpretation (N);
6043 procedure Remove_Address_Interpretations (Op : Operand_Position);
6044 -- Ambiguities may arise when the operands are literal and the address
6045 -- operations in s-auxdec are visible. In that case, remove the
6046 -- interpretation of a literal as Address, to retain the semantics of
6047 -- Address as a private type.
6049 ------------------------------------
6050 -- Remove_Address_Interpretations --
6051 ------------------------------------
6053 procedure Remove_Address_Interpretations (Op : Operand_Position) is
6057 if Is_Overloaded (N) then
6058 Get_First_Interp (N, I, It);
6059 while Present (It.Nam) loop
6060 Formal := First_Entity (It.Nam);
6062 if Op = Second_Op then
6063 Formal := Next_Entity (Formal);
6066 if Is_Descendent_Of_Address (Etype (Formal)) then
6067 Address_Kludge := True;
6071 Get_Next_Interp (I, It);
6074 end Remove_Address_Interpretations;
6076 -- Start of processing for Remove_Abstract_Operations
6079 if Is_Overloaded (N) then
6080 Get_First_Interp (N, I, It);
6082 while Present (It.Nam) loop
6083 if Is_Overloadable (It.Nam)
6084 and then Is_Abstract_Subprogram (It.Nam)
6085 and then not Is_Dispatching_Operation (It.Nam)
6087 Abstract_Op := It.Nam;
6089 if Is_Descendent_Of_Address (It.Typ) then
6090 Address_Kludge := True;
6094 -- In Ada 2005, this operation does not participate in Overload
6095 -- resolution. If the operation is defined in a predefined
6096 -- unit, it is one of the operations declared abstract in some
6097 -- variants of System, and it must be removed as well.
6099 elsif Ada_Version >= Ada_2005
6100 or else Is_Predefined_File_Name
6101 (Unit_File_Name (Get_Source_Unit (It.Nam)))
6108 Get_Next_Interp (I, It);
6111 if No (Abstract_Op) then
6113 -- If some interpretation yields an integer type, it is still
6114 -- possible that there are address interpretations. Remove them
6115 -- if one operand is a literal, to avoid spurious ambiguities
6116 -- on systems where Address is a visible integer type.
6118 if Is_Overloaded (N)
6119 and then Nkind (N) in N_Op
6120 and then Is_Integer_Type (Etype (N))
6122 if Nkind (N) in N_Binary_Op then
6123 if Nkind (Right_Opnd (N)) = N_Integer_Literal then
6124 Remove_Address_Interpretations (Second_Op);
6126 elsif Nkind (Right_Opnd (N)) = N_Integer_Literal then
6127 Remove_Address_Interpretations (First_Op);
6132 elsif Nkind (N) in N_Op then
6134 -- Remove interpretations that treat literals as addresses. This
6135 -- is never appropriate, even when Address is defined as a visible
6136 -- Integer type. The reason is that we would really prefer Address
6137 -- to behave as a private type, even in this case, which is there
6138 -- only to accommodate oddities of VMS address sizes. If Address
6139 -- is a visible integer type, we get lots of overload ambiguities.
6141 if Nkind (N) in N_Binary_Op then
6143 U1 : constant Boolean :=
6144 Present (Universal_Interpretation (Right_Opnd (N)));
6145 U2 : constant Boolean :=
6146 Present (Universal_Interpretation (Left_Opnd (N)));
6150 Remove_Address_Interpretations (Second_Op);
6154 Remove_Address_Interpretations (First_Op);
6157 if not (U1 and U2) then
6159 -- Remove corresponding predefined operator, which is
6160 -- always added to the overload set.
6162 Get_First_Interp (N, I, It);
6163 while Present (It.Nam) loop
6164 if Scope (It.Nam) = Standard_Standard
6165 and then Base_Type (It.Typ) =
6166 Base_Type (Etype (Abstract_Op))
6171 Get_Next_Interp (I, It);
6174 elsif Is_Overloaded (N)
6175 and then Present (Univ_Type)
6177 -- If both operands have a universal interpretation,
6178 -- it is still necessary to remove interpretations that
6179 -- yield Address. Any remaining ambiguities will be
6180 -- removed in Disambiguate.
6182 Get_First_Interp (N, I, It);
6183 while Present (It.Nam) loop
6184 if Is_Descendent_Of_Address (It.Typ) then
6187 elsif not Is_Type (It.Nam) then
6188 Set_Entity (N, It.Nam);
6191 Get_Next_Interp (I, It);
6197 elsif Nkind (N) = N_Function_Call
6199 (Nkind (Name (N)) = N_Operator_Symbol
6201 (Nkind (Name (N)) = N_Expanded_Name
6203 Nkind (Selector_Name (Name (N))) = N_Operator_Symbol))
6207 Arg1 : constant Node_Id := First (Parameter_Associations (N));
6208 U1 : constant Boolean :=
6209 Present (Universal_Interpretation (Arg1));
6210 U2 : constant Boolean :=
6211 Present (Next (Arg1)) and then
6212 Present (Universal_Interpretation (Next (Arg1)));
6216 Remove_Address_Interpretations (First_Op);
6220 Remove_Address_Interpretations (Second_Op);
6223 if not (U1 and U2) then
6224 Get_First_Interp (N, I, It);
6225 while Present (It.Nam) loop
6226 if Scope (It.Nam) = Standard_Standard
6227 and then It.Typ = Base_Type (Etype (Abstract_Op))
6232 Get_Next_Interp (I, It);
6238 -- If the removal has left no valid interpretations, emit an error
6239 -- message now and label node as illegal.
6241 if Present (Abstract_Op) then
6242 Get_First_Interp (N, I, It);
6246 -- Removal of abstract operation left no viable candidate
6248 Set_Etype (N, Any_Type);
6249 Error_Msg_Sloc := Sloc (Abstract_Op);
6251 ("cannot call abstract operation& declared#", N, Abstract_Op);
6253 -- In Ada 2005, an abstract operation may disable predefined
6254 -- operators. Since the context is not yet known, we mark the
6255 -- predefined operators as potentially hidden. Do not include
6256 -- predefined operators when addresses are involved since this
6257 -- case is handled separately.
6259 elsif Ada_Version >= Ada_2005
6260 and then not Address_Kludge
6262 while Present (It.Nam) loop
6263 if Is_Numeric_Type (It.Typ)
6264 and then Scope (It.Typ) = Standard_Standard
6266 Set_Abstract_Op (I, Abstract_Op);
6269 Get_Next_Interp (I, It);
6274 end Remove_Abstract_Operations;
6276 -----------------------
6277 -- Try_Indirect_Call --
6278 -----------------------
6280 function Try_Indirect_Call
6283 Typ : Entity_Id) return Boolean
6289 pragma Warnings (Off, Call_OK);
6292 Normalize_Actuals (N, Designated_Type (Typ), False, Call_OK);
6294 Actual := First_Actual (N);
6295 Formal := First_Formal (Designated_Type (Typ));
6296 while Present (Actual) and then Present (Formal) loop
6297 if not Has_Compatible_Type (Actual, Etype (Formal)) then
6302 Next_Formal (Formal);
6305 if No (Actual) and then No (Formal) then
6306 Add_One_Interp (N, Nam, Etype (Designated_Type (Typ)));
6308 -- Nam is a candidate interpretation for the name in the call,
6309 -- if it is not an indirect call.
6311 if not Is_Type (Nam)
6312 and then Is_Entity_Name (Name (N))
6314 Set_Entity (Name (N), Nam);
6321 end Try_Indirect_Call;
6323 ----------------------
6324 -- Try_Indexed_Call --
6325 ----------------------
6327 function Try_Indexed_Call
6331 Skip_First : Boolean) return Boolean
6333 Loc : constant Source_Ptr := Sloc (N);
6334 Actuals : constant List_Id := Parameter_Associations (N);
6339 Actual := First (Actuals);
6341 -- If the call was originally written in prefix form, skip the first
6342 -- actual, which is obviously not defaulted.
6348 Index := First_Index (Typ);
6349 while Present (Actual) and then Present (Index) loop
6351 -- If the parameter list has a named association, the expression
6352 -- is definitely a call and not an indexed component.
6354 if Nkind (Actual) = N_Parameter_Association then
6358 if Is_Entity_Name (Actual)
6359 and then Is_Type (Entity (Actual))
6360 and then No (Next (Actual))
6362 -- A single actual that is a type name indicates a slice if the
6363 -- type is discrete, and an error otherwise.
6365 if Is_Discrete_Type (Entity (Actual)) then
6369 Make_Function_Call (Loc,
6370 Name => Relocate_Node (Name (N))),
6372 New_Occurrence_Of (Entity (Actual), Sloc (Actual))));
6377 Error_Msg_N ("invalid use of type in expression", Actual);
6378 Set_Etype (N, Any_Type);
6383 elsif not Has_Compatible_Type (Actual, Etype (Index)) then
6391 if No (Actual) and then No (Index) then
6392 Add_One_Interp (N, Nam, Component_Type (Typ));
6394 -- Nam is a candidate interpretation for the name in the call,
6395 -- if it is not an indirect call.
6397 if not Is_Type (Nam)
6398 and then Is_Entity_Name (Name (N))
6400 Set_Entity (Name (N), Nam);
6407 end Try_Indexed_Call;
6409 --------------------------
6410 -- Try_Object_Operation --
6411 --------------------------
6413 function Try_Object_Operation (N : Node_Id) return Boolean is
6414 K : constant Node_Kind := Nkind (Parent (N));
6415 Is_Subprg_Call : constant Boolean := Nkind_In
6416 (K, N_Procedure_Call_Statement,
6418 Loc : constant Source_Ptr := Sloc (N);
6419 Obj : constant Node_Id := Prefix (N);
6421 Subprog : constant Node_Id :=
6422 Make_Identifier (Sloc (Selector_Name (N)),
6423 Chars => Chars (Selector_Name (N)));
6424 -- Identifier on which possible interpretations will be collected
6426 Report_Error : Boolean := False;
6427 -- If no candidate interpretation matches the context, redo the
6428 -- analysis with error enabled to provide additional information.
6431 Candidate : Entity_Id := Empty;
6432 New_Call_Node : Node_Id := Empty;
6433 Node_To_Replace : Node_Id;
6434 Obj_Type : Entity_Id := Etype (Obj);
6435 Success : Boolean := False;
6437 function Valid_Candidate
6440 Subp : Entity_Id) return Entity_Id;
6441 -- If the subprogram is a valid interpretation, record it, and add
6442 -- to the list of interpretations of Subprog.
6444 procedure Complete_Object_Operation
6445 (Call_Node : Node_Id;
6446 Node_To_Replace : Node_Id);
6447 -- Make Subprog the name of Call_Node, replace Node_To_Replace with
6448 -- Call_Node, insert the object (or its dereference) as the first actual
6449 -- in the call, and complete the analysis of the call.
6451 procedure Report_Ambiguity (Op : Entity_Id);
6452 -- If a prefixed procedure call is ambiguous, indicate whether the
6453 -- call includes an implicit dereference or an implicit 'Access.
6455 procedure Transform_Object_Operation
6456 (Call_Node : out Node_Id;
6457 Node_To_Replace : out Node_Id);
6458 -- Transform Obj.Operation (X, Y,,) into Operation (Obj, X, Y ..)
6459 -- Call_Node is the resulting subprogram call, Node_To_Replace is
6460 -- either N or the parent of N, and Subprog is a reference to the
6461 -- subprogram we are trying to match.
6463 function Try_Class_Wide_Operation
6464 (Call_Node : Node_Id;
6465 Node_To_Replace : Node_Id) return Boolean;
6466 -- Traverse all ancestor types looking for a class-wide subprogram
6467 -- for which the current operation is a valid non-dispatching call.
6469 procedure Try_One_Prefix_Interpretation (T : Entity_Id);
6470 -- If prefix is overloaded, its interpretation may include different
6471 -- tagged types, and we must examine the primitive operations and
6472 -- the class-wide operations of each in order to find candidate
6473 -- interpretations for the call as a whole.
6475 function Try_Primitive_Operation
6476 (Call_Node : Node_Id;
6477 Node_To_Replace : Node_Id) return Boolean;
6478 -- Traverse the list of primitive subprograms looking for a dispatching
6479 -- operation for which the current node is a valid call .
6481 ---------------------
6482 -- Valid_Candidate --
6483 ---------------------
6485 function Valid_Candidate
6488 Subp : Entity_Id) return Entity_Id
6490 Arr_Type : Entity_Id;
6491 Comp_Type : Entity_Id;
6494 -- If the subprogram is a valid interpretation, record it in global
6495 -- variable Subprog, to collect all possible overloadings.
6498 if Subp /= Entity (Subprog) then
6499 Add_One_Interp (Subprog, Subp, Etype (Subp));
6503 -- If the call may be an indexed call, retrieve component type of
6504 -- resulting expression, and add possible interpretation.
6509 if Nkind (Call) = N_Function_Call
6510 and then Nkind (Parent (N)) = N_Indexed_Component
6511 and then Needs_One_Actual (Subp)
6513 if Is_Array_Type (Etype (Subp)) then
6514 Arr_Type := Etype (Subp);
6516 elsif Is_Access_Type (Etype (Subp))
6517 and then Is_Array_Type (Designated_Type (Etype (Subp)))
6519 Arr_Type := Designated_Type (Etype (Subp));
6523 if Present (Arr_Type) then
6525 -- Verify that the actuals (excluding the object) match the types
6533 Actual := Next (First_Actual (Call));
6534 Index := First_Index (Arr_Type);
6535 while Present (Actual) and then Present (Index) loop
6536 if not Has_Compatible_Type (Actual, Etype (Index)) then
6541 Next_Actual (Actual);
6547 and then Present (Arr_Type)
6549 Comp_Type := Component_Type (Arr_Type);
6553 if Present (Comp_Type)
6554 and then Etype (Subprog) /= Comp_Type
6556 Add_One_Interp (Subprog, Subp, Comp_Type);
6560 if Etype (Call) /= Any_Type then
6565 end Valid_Candidate;
6567 -------------------------------
6568 -- Complete_Object_Operation --
6569 -------------------------------
6571 procedure Complete_Object_Operation
6572 (Call_Node : Node_Id;
6573 Node_To_Replace : Node_Id)
6575 Control : constant Entity_Id := First_Formal (Entity (Subprog));
6576 Formal_Type : constant Entity_Id := Etype (Control);
6577 First_Actual : Node_Id;
6580 -- Place the name of the operation, with its interpretations,
6581 -- on the rewritten call.
6583 Set_Name (Call_Node, Subprog);
6585 First_Actual := First (Parameter_Associations (Call_Node));
6587 -- For cross-reference purposes, treat the new node as being in
6588 -- the source if the original one is.
6590 Set_Comes_From_Source (Subprog, Comes_From_Source (N));
6591 Set_Comes_From_Source (Call_Node, Comes_From_Source (N));
6593 if Nkind (N) = N_Selected_Component
6594 and then not Inside_A_Generic
6596 Set_Entity (Selector_Name (N), Entity (Subprog));
6599 -- If need be, rewrite first actual as an explicit dereference
6600 -- If the call is overloaded, the rewriting can only be done
6601 -- once the primitive operation is identified.
6603 if Is_Overloaded (Subprog) then
6605 -- The prefix itself may be overloaded, and its interpretations
6606 -- must be propagated to the new actual in the call.
6608 if Is_Overloaded (Obj) then
6609 Save_Interps (Obj, First_Actual);
6612 Rewrite (First_Actual, Obj);
6614 elsif not Is_Access_Type (Formal_Type)
6615 and then Is_Access_Type (Etype (Obj))
6617 Rewrite (First_Actual,
6618 Make_Explicit_Dereference (Sloc (Obj), Obj));
6619 Analyze (First_Actual);
6621 -- If we need to introduce an explicit dereference, verify that
6622 -- the resulting actual is compatible with the mode of the formal.
6624 if Ekind (First_Formal (Entity (Subprog))) /= E_In_Parameter
6625 and then Is_Access_Constant (Etype (Obj))
6628 ("expect variable in call to&", Prefix (N), Entity (Subprog));
6631 -- Conversely, if the formal is an access parameter and the object
6632 -- is not, replace the actual with a 'Access reference. Its analysis
6633 -- will check that the object is aliased.
6635 elsif Is_Access_Type (Formal_Type)
6636 and then not Is_Access_Type (Etype (Obj))
6638 -- A special case: A.all'access is illegal if A is an access to a
6639 -- constant and the context requires an access to a variable.
6641 if not Is_Access_Constant (Formal_Type) then
6642 if (Nkind (Obj) = N_Explicit_Dereference
6643 and then Is_Access_Constant (Etype (Prefix (Obj))))
6644 or else not Is_Variable (Obj)
6647 ("actual for& must be a variable", Obj, Control);
6651 Rewrite (First_Actual,
6652 Make_Attribute_Reference (Loc,
6653 Attribute_Name => Name_Access,
6654 Prefix => Relocate_Node (Obj)));
6656 if not Is_Aliased_View (Obj) then
6658 ("object in prefixed call to& must be aliased"
6659 & " (RM-2005 4.3.1 (13))",
6660 Prefix (First_Actual), Subprog);
6663 Analyze (First_Actual);
6666 if Is_Overloaded (Obj) then
6667 Save_Interps (Obj, First_Actual);
6670 Rewrite (First_Actual, Obj);
6673 Rewrite (Node_To_Replace, Call_Node);
6675 -- Propagate the interpretations collected in subprog to the new
6676 -- function call node, to be resolved from context.
6678 if Is_Overloaded (Subprog) then
6679 Save_Interps (Subprog, Node_To_Replace);
6682 Analyze (Node_To_Replace);
6684 -- If the operation has been rewritten into a call, which may get
6685 -- subsequently an explicit dereference, preserve the type on the
6686 -- original node (selected component or indexed component) for
6687 -- subsequent legality tests, e.g. Is_Variable. which examines
6688 -- the original node.
6690 if Nkind (Node_To_Replace) = N_Function_Call then
6692 (Original_Node (Node_To_Replace), Etype (Node_To_Replace));
6695 end Complete_Object_Operation;
6697 ----------------------
6698 -- Report_Ambiguity --
6699 ----------------------
6701 procedure Report_Ambiguity (Op : Entity_Id) is
6702 Access_Formal : constant Boolean :=
6703 Is_Access_Type (Etype (First_Formal (Op)));
6704 Access_Actual : constant Boolean :=
6705 Is_Access_Type (Etype (Prefix (N)));
6708 Error_Msg_Sloc := Sloc (Op);
6710 if Access_Formal and then not Access_Actual then
6711 if Nkind (Parent (Op)) = N_Full_Type_Declaration then
6713 ("\possible interpretation"
6714 & " (inherited, with implicit 'Access) #", N);
6717 ("\possible interpretation (with implicit 'Access) #", N);
6720 elsif not Access_Formal and then Access_Actual then
6721 if Nkind (Parent (Op)) = N_Full_Type_Declaration then
6723 ("\possible interpretation"
6724 & " ( inherited, with implicit dereference) #", N);
6727 ("\possible interpretation (with implicit dereference) #", N);
6731 if Nkind (Parent (Op)) = N_Full_Type_Declaration then
6732 Error_Msg_N ("\possible interpretation (inherited)#", N);
6734 Error_Msg_N -- CODEFIX
6735 ("\possible interpretation#", N);
6738 end Report_Ambiguity;
6740 --------------------------------
6741 -- Transform_Object_Operation --
6742 --------------------------------
6744 procedure Transform_Object_Operation
6745 (Call_Node : out Node_Id;
6746 Node_To_Replace : out Node_Id)
6748 Dummy : constant Node_Id := New_Copy (Obj);
6749 -- Placeholder used as a first parameter in the call, replaced
6750 -- eventually by the proper object.
6752 Parent_Node : constant Node_Id := Parent (N);
6758 -- Common case covering 1) Call to a procedure and 2) Call to a
6759 -- function that has some additional actuals.
6761 if Nkind_In (Parent_Node, N_Function_Call,
6762 N_Procedure_Call_Statement)
6764 -- N is a selected component node containing the name of the
6765 -- subprogram. If N is not the name of the parent node we must
6766 -- not replace the parent node by the new construct. This case
6767 -- occurs when N is a parameterless call to a subprogram that
6768 -- is an actual parameter of a call to another subprogram. For
6770 -- Some_Subprogram (..., Obj.Operation, ...)
6772 and then Name (Parent_Node) = N
6774 Node_To_Replace := Parent_Node;
6776 Actuals := Parameter_Associations (Parent_Node);
6778 if Present (Actuals) then
6779 Prepend (Dummy, Actuals);
6781 Actuals := New_List (Dummy);
6784 if Nkind (Parent_Node) = N_Procedure_Call_Statement then
6786 Make_Procedure_Call_Statement (Loc,
6787 Name => New_Copy (Subprog),
6788 Parameter_Associations => Actuals);
6792 Make_Function_Call (Loc,
6793 Name => New_Copy (Subprog),
6794 Parameter_Associations => Actuals);
6798 -- Before analysis, a function call appears as an indexed component
6799 -- if there are no named associations.
6801 elsif Nkind (Parent_Node) = N_Indexed_Component
6802 and then N = Prefix (Parent_Node)
6804 Node_To_Replace := Parent_Node;
6805 Actuals := Expressions (Parent_Node);
6807 Actual := First (Actuals);
6808 while Present (Actual) loop
6813 Prepend (Dummy, Actuals);
6816 Make_Function_Call (Loc,
6817 Name => New_Copy (Subprog),
6818 Parameter_Associations => Actuals);
6820 -- Parameterless call: Obj.F is rewritten as F (Obj)
6823 Node_To_Replace := N;
6826 Make_Function_Call (Loc,
6827 Name => New_Copy (Subprog),
6828 Parameter_Associations => New_List (Dummy));
6830 end Transform_Object_Operation;
6832 ------------------------------
6833 -- Try_Class_Wide_Operation --
6834 ------------------------------
6836 function Try_Class_Wide_Operation
6837 (Call_Node : Node_Id;
6838 Node_To_Replace : Node_Id) return Boolean
6840 Anc_Type : Entity_Id;
6841 Matching_Op : Entity_Id := Empty;
6844 procedure Traverse_Homonyms
6845 (Anc_Type : Entity_Id;
6846 Error : out Boolean);
6847 -- Traverse the homonym chain of the subprogram searching for those
6848 -- homonyms whose first formal has the Anc_Type's class-wide type,
6849 -- or an anonymous access type designating the class-wide type. If
6850 -- an ambiguity is detected, then Error is set to True.
6852 procedure Traverse_Interfaces
6853 (Anc_Type : Entity_Id;
6854 Error : out Boolean);
6855 -- Traverse the list of interfaces, if any, associated with Anc_Type
6856 -- and search for acceptable class-wide homonyms associated with each
6857 -- interface. If an ambiguity is detected, then Error is set to True.
6859 -----------------------
6860 -- Traverse_Homonyms --
6861 -----------------------
6863 procedure Traverse_Homonyms
6864 (Anc_Type : Entity_Id;
6865 Error : out Boolean)
6867 Cls_Type : Entity_Id;
6875 Cls_Type := Class_Wide_Type (Anc_Type);
6877 Hom := Current_Entity (Subprog);
6879 -- Find a non-hidden operation whose first parameter is of the
6880 -- class-wide type, a subtype thereof, or an anonymous access
6883 while Present (Hom) loop
6884 if Ekind_In (Hom, E_Procedure, E_Function)
6885 and then not Is_Hidden (Hom)
6886 and then Scope (Hom) = Scope (Anc_Type)
6887 and then Present (First_Formal (Hom))
6889 (Base_Type (Etype (First_Formal (Hom))) = Cls_Type
6891 (Is_Access_Type (Etype (First_Formal (Hom)))
6893 Ekind (Etype (First_Formal (Hom))) =
6894 E_Anonymous_Access_Type
6897 (Designated_Type (Etype (First_Formal (Hom)))) =
6900 Set_Etype (Call_Node, Any_Type);
6901 Set_Is_Overloaded (Call_Node, False);
6904 if No (Matching_Op) then
6905 Hom_Ref := New_Reference_To (Hom, Sloc (Subprog));
6906 Set_Etype (Call_Node, Any_Type);
6907 Set_Parent (Call_Node, Parent (Node_To_Replace));
6909 Set_Name (Call_Node, Hom_Ref);
6914 Report => Report_Error,
6916 Skip_First => True);
6919 Valid_Candidate (Success, Call_Node, Hom);
6925 Report => Report_Error,
6927 Skip_First => True);
6929 if Present (Valid_Candidate (Success, Call_Node, Hom))
6930 and then Nkind (Call_Node) /= N_Function_Call
6932 Error_Msg_NE ("ambiguous call to&", N, Hom);
6933 Report_Ambiguity (Matching_Op);
6934 Report_Ambiguity (Hom);
6941 Hom := Homonym (Hom);
6943 end Traverse_Homonyms;
6945 -------------------------
6946 -- Traverse_Interfaces --
6947 -------------------------
6949 procedure Traverse_Interfaces
6950 (Anc_Type : Entity_Id;
6951 Error : out Boolean)
6953 Intface_List : constant List_Id :=
6954 Abstract_Interface_List (Anc_Type);
6960 if Is_Non_Empty_List (Intface_List) then
6961 Intface := First (Intface_List);
6962 while Present (Intface) loop
6964 -- Look for acceptable class-wide homonyms associated with
6967 Traverse_Homonyms (Etype (Intface), Error);
6973 -- Continue the search by looking at each of the interface's
6974 -- associated interface ancestors.
6976 Traverse_Interfaces (Etype (Intface), Error);
6985 end Traverse_Interfaces;
6987 -- Start of processing for Try_Class_Wide_Operation
6990 -- Loop through ancestor types (including interfaces), traversing
6991 -- the homonym chain of the subprogram, trying out those homonyms
6992 -- whose first formal has the class-wide type of the ancestor, or
6993 -- an anonymous access type designating the class-wide type.
6995 Anc_Type := Obj_Type;
6997 -- Look for a match among homonyms associated with the ancestor
6999 Traverse_Homonyms (Anc_Type, Error);
7005 -- Continue the search for matches among homonyms associated with
7006 -- any interfaces implemented by the ancestor.
7008 Traverse_Interfaces (Anc_Type, Error);
7014 exit when Etype (Anc_Type) = Anc_Type;
7015 Anc_Type := Etype (Anc_Type);
7018 if Present (Matching_Op) then
7019 Set_Etype (Call_Node, Etype (Matching_Op));
7022 return Present (Matching_Op);
7023 end Try_Class_Wide_Operation;
7025 -----------------------------------
7026 -- Try_One_Prefix_Interpretation --
7027 -----------------------------------
7029 procedure Try_One_Prefix_Interpretation (T : Entity_Id) is
7033 if Is_Access_Type (Obj_Type) then
7034 Obj_Type := Designated_Type (Obj_Type);
7037 if Ekind (Obj_Type) = E_Private_Subtype then
7038 Obj_Type := Base_Type (Obj_Type);
7041 if Is_Class_Wide_Type (Obj_Type) then
7042 Obj_Type := Etype (Class_Wide_Type (Obj_Type));
7045 -- The type may have be obtained through a limited_with clause,
7046 -- in which case the primitive operations are available on its
7047 -- non-limited view. If still incomplete, retrieve full view.
7049 if Ekind (Obj_Type) = E_Incomplete_Type
7050 and then From_With_Type (Obj_Type)
7052 Obj_Type := Get_Full_View (Non_Limited_View (Obj_Type));
7055 -- If the object is not tagged, or the type is still an incomplete
7056 -- type, this is not a prefixed call.
7058 if not Is_Tagged_Type (Obj_Type)
7059 or else Is_Incomplete_Type (Obj_Type)
7064 if Try_Primitive_Operation
7065 (Call_Node => New_Call_Node,
7066 Node_To_Replace => Node_To_Replace)
7068 Try_Class_Wide_Operation
7069 (Call_Node => New_Call_Node,
7070 Node_To_Replace => Node_To_Replace)
7074 end Try_One_Prefix_Interpretation;
7076 -----------------------------
7077 -- Try_Primitive_Operation --
7078 -----------------------------
7080 function Try_Primitive_Operation
7081 (Call_Node : Node_Id;
7082 Node_To_Replace : Node_Id) return Boolean
7085 Prim_Op : Entity_Id;
7086 Matching_Op : Entity_Id := Empty;
7087 Prim_Op_Ref : Node_Id := Empty;
7089 Corr_Type : Entity_Id := Empty;
7090 -- If the prefix is a synchronized type, the controlling type of
7091 -- the primitive operation is the corresponding record type, else
7092 -- this is the object type itself.
7094 Success : Boolean := False;
7096 function Collect_Generic_Type_Ops (T : Entity_Id) return Elist_Id;
7097 -- For tagged types the candidate interpretations are found in
7098 -- the list of primitive operations of the type and its ancestors.
7099 -- For formal tagged types we have to find the operations declared
7100 -- in the same scope as the type (including in the generic formal
7101 -- part) because the type itself carries no primitive operations,
7102 -- except for formal derived types that inherit the operations of
7103 -- the parent and progenitors.
7104 -- If the context is a generic subprogram body, the generic formals
7105 -- are visible by name, but are not in the entity list of the
7106 -- subprogram because that list starts with the subprogram formals.
7107 -- We retrieve the candidate operations from the generic declaration.
7109 function Is_Private_Overriding (Op : Entity_Id) return Boolean;
7110 -- An operation that overrides an inherited operation in the private
7111 -- part of its package may be hidden, but if the inherited operation
7112 -- is visible a direct call to it will dispatch to the private one,
7113 -- which is therefore a valid candidate.
7115 function Valid_First_Argument_Of (Op : Entity_Id) return Boolean;
7116 -- Verify that the prefix, dereferenced if need be, is a valid
7117 -- controlling argument in a call to Op. The remaining actuals
7118 -- are checked in the subsequent call to Analyze_One_Call.
7120 ------------------------------
7121 -- Collect_Generic_Type_Ops --
7122 ------------------------------
7124 function Collect_Generic_Type_Ops (T : Entity_Id) return Elist_Id is
7125 Bas : constant Entity_Id := Base_Type (T);
7126 Candidates : constant Elist_Id := New_Elmt_List;
7130 procedure Check_Candidate;
7131 -- The operation is a candidate if its first parameter is a
7132 -- controlling operand of the desired type.
7134 -----------------------
7135 -- Check_Candidate; --
7136 -----------------------
7138 procedure Check_Candidate is
7140 Formal := First_Formal (Subp);
7143 and then Is_Controlling_Formal (Formal)
7145 (Base_Type (Etype (Formal)) = Bas
7147 (Is_Access_Type (Etype (Formal))
7148 and then Designated_Type (Etype (Formal)) = Bas))
7150 Append_Elmt (Subp, Candidates);
7152 end Check_Candidate;
7154 -- Start of processing for Collect_Generic_Type_Ops
7157 if Is_Derived_Type (T) then
7158 return Primitive_Operations (T);
7160 elsif Ekind_In (Scope (T), E_Procedure, E_Function) then
7162 -- Scan the list of generic formals to find subprograms
7163 -- that may have a first controlling formal of the type.
7165 if Nkind (Unit_Declaration_Node (Scope (T)))
7166 = N_Generic_Subprogram_Declaration
7173 First (Generic_Formal_Declarations
7174 (Unit_Declaration_Node (Scope (T))));
7175 while Present (Decl) loop
7176 if Nkind (Decl) in N_Formal_Subprogram_Declaration then
7177 Subp := Defining_Entity (Decl);
7188 -- Scan the list of entities declared in the same scope as
7189 -- the type. In general this will be an open scope, given that
7190 -- the call we are analyzing can only appear within a generic
7191 -- declaration or body (either the one that declares T, or a
7194 -- For a subtype representing a generic actual type, go to the
7197 if Is_Generic_Actual_Type (T) then
7198 Subp := First_Entity (Scope (Base_Type (T)));
7200 Subp := First_Entity (Scope (T));
7203 while Present (Subp) loop
7204 if Is_Overloadable (Subp) then
7213 end Collect_Generic_Type_Ops;
7215 ---------------------------
7216 -- Is_Private_Overriding --
7217 ---------------------------
7219 function Is_Private_Overriding (Op : Entity_Id) return Boolean is
7220 Visible_Op : constant Entity_Id := Homonym (Op);
7223 return Present (Visible_Op)
7224 and then Scope (Op) = Scope (Visible_Op)
7225 and then not Comes_From_Source (Visible_Op)
7226 and then Alias (Visible_Op) = Op
7227 and then not Is_Hidden (Visible_Op);
7228 end Is_Private_Overriding;
7230 -----------------------------
7231 -- Valid_First_Argument_Of --
7232 -----------------------------
7234 function Valid_First_Argument_Of (Op : Entity_Id) return Boolean is
7235 Typ : Entity_Id := Etype (First_Formal (Op));
7238 if Is_Concurrent_Type (Typ)
7239 and then Present (Corresponding_Record_Type (Typ))
7241 Typ := Corresponding_Record_Type (Typ);
7244 -- Simple case. Object may be a subtype of the tagged type or
7245 -- may be the corresponding record of a synchronized type.
7247 return Obj_Type = Typ
7248 or else Base_Type (Obj_Type) = Typ
7249 or else Corr_Type = Typ
7251 -- Prefix can be dereferenced
7254 (Is_Access_Type (Corr_Type)
7255 and then Designated_Type (Corr_Type) = Typ)
7257 -- Formal is an access parameter, for which the object
7258 -- can provide an access.
7261 (Ekind (Typ) = E_Anonymous_Access_Type
7262 and then Designated_Type (Typ) = Base_Type (Corr_Type));
7263 end Valid_First_Argument_Of;
7265 -- Start of processing for Try_Primitive_Operation
7268 -- Look for subprograms in the list of primitive operations. The name
7269 -- must be identical, and the kind of call indicates the expected
7270 -- kind of operation (function or procedure). If the type is a
7271 -- (tagged) synchronized type, the primitive ops are attached to the
7272 -- corresponding record (base) type.
7274 if Is_Concurrent_Type (Obj_Type) then
7275 if Present (Corresponding_Record_Type (Obj_Type)) then
7276 Corr_Type := Base_Type (Corresponding_Record_Type (Obj_Type));
7277 Elmt := First_Elmt (Primitive_Operations (Corr_Type));
7279 Corr_Type := Obj_Type;
7280 Elmt := First_Elmt (Collect_Generic_Type_Ops (Obj_Type));
7283 elsif not Is_Generic_Type (Obj_Type) then
7284 Corr_Type := Obj_Type;
7285 Elmt := First_Elmt (Primitive_Operations (Obj_Type));
7288 Corr_Type := Obj_Type;
7289 Elmt := First_Elmt (Collect_Generic_Type_Ops (Obj_Type));
7292 while Present (Elmt) loop
7293 Prim_Op := Node (Elmt);
7295 if Chars (Prim_Op) = Chars (Subprog)
7296 and then Present (First_Formal (Prim_Op))
7297 and then Valid_First_Argument_Of (Prim_Op)
7299 (Nkind (Call_Node) = N_Function_Call)
7300 = (Ekind (Prim_Op) = E_Function)
7302 -- Ada 2005 (AI-251): If this primitive operation corresponds
7303 -- with an immediate ancestor interface there is no need to add
7304 -- it to the list of interpretations; the corresponding aliased
7305 -- primitive is also in this list of primitive operations and
7306 -- will be used instead.
7308 if (Present (Interface_Alias (Prim_Op))
7309 and then Is_Ancestor (Find_Dispatching_Type
7310 (Alias (Prim_Op)), Corr_Type))
7312 -- Do not consider hidden primitives unless the type is in an
7313 -- open scope or we are within an instance, where visibility
7314 -- is known to be correct, or else if this is an overriding
7315 -- operation in the private part for an inherited operation.
7317 or else (Is_Hidden (Prim_Op)
7318 and then not Is_Immediately_Visible (Obj_Type)
7319 and then not In_Instance
7320 and then not Is_Private_Overriding (Prim_Op))
7325 Set_Etype (Call_Node, Any_Type);
7326 Set_Is_Overloaded (Call_Node, False);
7328 if No (Matching_Op) then
7329 Prim_Op_Ref := New_Reference_To (Prim_Op, Sloc (Subprog));
7330 Candidate := Prim_Op;
7332 Set_Parent (Call_Node, Parent (Node_To_Replace));
7334 Set_Name (Call_Node, Prim_Op_Ref);
7340 Report => Report_Error,
7342 Skip_First => True);
7344 Matching_Op := Valid_Candidate (Success, Call_Node, Prim_Op);
7346 -- More than one interpretation, collect for subsequent
7347 -- disambiguation. If this is a procedure call and there
7348 -- is another match, report ambiguity now.
7354 Report => Report_Error,
7356 Skip_First => True);
7358 if Present (Valid_Candidate (Success, Call_Node, Prim_Op))
7359 and then Nkind (Call_Node) /= N_Function_Call
7361 Error_Msg_NE ("ambiguous call to&", N, Prim_Op);
7362 Report_Ambiguity (Matching_Op);
7363 Report_Ambiguity (Prim_Op);
7373 if Present (Matching_Op) then
7374 Set_Etype (Call_Node, Etype (Matching_Op));
7377 return Present (Matching_Op);
7378 end Try_Primitive_Operation;
7380 -- Start of processing for Try_Object_Operation
7383 Analyze_Expression (Obj);
7385 -- Analyze the actuals if node is known to be a subprogram call
7387 if Is_Subprg_Call and then N = Name (Parent (N)) then
7388 Actual := First (Parameter_Associations (Parent (N)));
7389 while Present (Actual) loop
7390 Analyze_Expression (Actual);
7395 -- Build a subprogram call node, using a copy of Obj as its first
7396 -- actual. This is a placeholder, to be replaced by an explicit
7397 -- dereference when needed.
7399 Transform_Object_Operation
7400 (Call_Node => New_Call_Node,
7401 Node_To_Replace => Node_To_Replace);
7403 Set_Etype (New_Call_Node, Any_Type);
7404 Set_Etype (Subprog, Any_Type);
7405 Set_Parent (New_Call_Node, Parent (Node_To_Replace));
7407 if not Is_Overloaded (Obj) then
7408 Try_One_Prefix_Interpretation (Obj_Type);
7415 Get_First_Interp (Obj, I, It);
7416 while Present (It.Nam) loop
7417 Try_One_Prefix_Interpretation (It.Typ);
7418 Get_Next_Interp (I, It);
7423 if Etype (New_Call_Node) /= Any_Type then
7424 Complete_Object_Operation
7425 (Call_Node => New_Call_Node,
7426 Node_To_Replace => Node_To_Replace);
7429 elsif Present (Candidate) then
7431 -- The argument list is not type correct. Re-analyze with error
7432 -- reporting enabled, and use one of the possible candidates.
7433 -- In All_Errors_Mode, re-analyze all failed interpretations.
7435 if All_Errors_Mode then
7436 Report_Error := True;
7437 if Try_Primitive_Operation
7438 (Call_Node => New_Call_Node,
7439 Node_To_Replace => Node_To_Replace)
7442 Try_Class_Wide_Operation
7443 (Call_Node => New_Call_Node,
7444 Node_To_Replace => Node_To_Replace)
7451 (N => New_Call_Node,
7455 Skip_First => True);
7458 -- No need for further errors
7463 -- There was no candidate operation, so report it as an error
7464 -- in the caller: Analyze_Selected_Component.
7468 end Try_Object_Operation;
7474 procedure wpo (T : Entity_Id) is
7479 if not Is_Tagged_Type (T) then
7483 E := First_Elmt (Primitive_Operations (Base_Type (T)));
7484 while Present (E) loop
7486 Write_Int (Int (Op));
7487 Write_Str (" === ");
7488 Write_Name (Chars (Op));
7490 Write_Name (Chars (Scope (Op)));