1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2010, Free Software Foundation, Inc. --
11 -- GNAT is free software; you can redistribute it and/or modify it under --
12 -- terms of the GNU General Public License as published by the Free Soft- --
13 -- ware Foundation; either version 3, or (at your option) any later ver- --
14 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
15 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
16 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
17 -- for more details. You should have received a copy of the GNU General --
18 -- Public License distributed with GNAT; see file COPYING3. If not, go to --
19 -- http://www.gnu.org/licenses for a complete copy of the license. --
21 -- GNAT was originally developed by the GNAT team at New York University. --
22 -- Extensive contributions were provided by Ada Core Technologies Inc. --
24 ------------------------------------------------------------------------------
26 with Atree; use Atree;
27 with Debug; use Debug;
28 with Einfo; use Einfo;
29 with Elists; use Elists;
30 with Errout; use Errout;
31 with Exp_Util; use Exp_Util;
32 with Fname; use Fname;
33 with Itypes; use Itypes;
35 with Lib.Xref; use Lib.Xref;
36 with Namet; use Namet;
37 with Namet.Sp; use Namet.Sp;
38 with Nlists; use Nlists;
39 with Nmake; use Nmake;
41 with Output; use Output;
42 with Restrict; use Restrict;
43 with Rident; use Rident;
45 with Sem_Aux; use Sem_Aux;
46 with Sem_Case; use Sem_Case;
47 with Sem_Cat; use Sem_Cat;
48 with Sem_Ch3; use Sem_Ch3;
49 with Sem_Ch5; use Sem_Ch5;
50 with Sem_Ch6; use Sem_Ch6;
51 with Sem_Ch8; use Sem_Ch8;
52 with Sem_Disp; use Sem_Disp;
53 with Sem_Dist; use Sem_Dist;
54 with Sem_Eval; use Sem_Eval;
55 with Sem_Res; use Sem_Res;
56 with Sem_Type; use Sem_Type;
57 with Sem_Util; use Sem_Util;
58 with Sem_Warn; use Sem_Warn;
59 with Stand; use Stand;
60 with Sinfo; use Sinfo;
61 with Snames; use Snames;
62 with Tbuild; use Tbuild;
64 package body Sem_Ch4 is
66 -----------------------
67 -- Local Subprograms --
68 -----------------------
70 procedure Analyze_Concatenation_Rest (N : Node_Id);
71 -- Does the "rest" of the work of Analyze_Concatenation, after the left
72 -- operand has been analyzed. See Analyze_Concatenation for details.
74 procedure Analyze_Expression (N : Node_Id);
75 -- For expressions that are not names, this is just a call to analyze.
76 -- If the expression is a name, it may be a call to a parameterless
77 -- function, and if so must be converted into an explicit call node
78 -- and analyzed as such. This deproceduring must be done during the first
79 -- pass of overload resolution, because otherwise a procedure call with
80 -- overloaded actuals may fail to resolve.
82 procedure Analyze_Operator_Call (N : Node_Id; Op_Id : Entity_Id);
83 -- Analyze a call of the form "+"(x, y), etc. The prefix of the call
84 -- is an operator name or an expanded name whose selector is an operator
85 -- name, and one possible interpretation is as a predefined operator.
87 procedure Analyze_Overloaded_Selected_Component (N : Node_Id);
88 -- If the prefix of a selected_component is overloaded, the proper
89 -- interpretation that yields a record type with the proper selector
90 -- name must be selected.
92 procedure Analyze_User_Defined_Binary_Op (N : Node_Id; Op_Id : Entity_Id);
93 -- Procedure to analyze a user defined binary operator, which is resolved
94 -- like a function, but instead of a list of actuals it is presented
95 -- with the left and right operands of an operator node.
97 procedure Analyze_User_Defined_Unary_Op (N : Node_Id; Op_Id : Entity_Id);
98 -- Procedure to analyze a user defined unary operator, which is resolved
99 -- like a function, but instead of a list of actuals, it is presented with
100 -- the operand of the operator node.
102 procedure Ambiguous_Operands (N : Node_Id);
103 -- For equality, membership, and comparison operators with overloaded
104 -- arguments, list possible interpretations.
106 procedure Analyze_One_Call
110 Success : out Boolean;
111 Skip_First : Boolean := False);
112 -- Check one interpretation of an overloaded subprogram name for
113 -- compatibility with the types of the actuals in a call. If there is a
114 -- single interpretation which does not match, post error if Report is
117 -- Nam is the entity that provides the formals against which the actuals
118 -- are checked. Nam is either the name of a subprogram, or the internal
119 -- subprogram type constructed for an access_to_subprogram. If the actuals
120 -- are compatible with Nam, then Nam is added to the list of candidate
121 -- interpretations for N, and Success is set to True.
123 -- The flag Skip_First is used when analyzing a call that was rewritten
124 -- from object notation. In this case the first actual may have to receive
125 -- an explicit dereference, depending on the first formal of the operation
126 -- being called. The caller will have verified that the object is legal
127 -- for the call. If the remaining parameters match, the first parameter
128 -- will rewritten as a dereference if needed, prior to completing analysis.
130 procedure Check_Misspelled_Selector
133 -- Give possible misspelling diagnostic if Sel is likely to be a mis-
134 -- spelling of one of the selectors of the Prefix. This is called by
135 -- Analyze_Selected_Component after producing an invalid selector error
138 function Defined_In_Scope (T : Entity_Id; S : Entity_Id) return Boolean;
139 -- Verify that type T is declared in scope S. Used to find interpretations
140 -- for operators given by expanded names. This is abstracted as a separate
141 -- function to handle extensions to System, where S is System, but T is
142 -- declared in the extension.
144 procedure Find_Arithmetic_Types
148 -- L and R are the operands of an arithmetic operator. Find
149 -- consistent pairs of interpretations for L and R that have a
150 -- numeric type consistent with the semantics of the operator.
152 procedure Find_Comparison_Types
156 -- L and R are operands of a comparison operator. Find consistent
157 -- pairs of interpretations for L and R.
159 procedure Find_Concatenation_Types
163 -- For the four varieties of concatenation
165 procedure Find_Equality_Types
169 -- Ditto for equality operators
171 procedure Find_Boolean_Types
175 -- Ditto for binary logical operations
177 procedure Find_Negation_Types
181 -- Find consistent interpretation for operand of negation operator
183 procedure Find_Non_Universal_Interpretations
188 -- For equality and comparison operators, the result is always boolean,
189 -- and the legality of the operation is determined from the visibility
190 -- of the operand types. If one of the operands has a universal interpre-
191 -- tation, the legality check uses some compatible non-universal
192 -- interpretation of the other operand. N can be an operator node, or
193 -- a function call whose name is an operator designator.
195 function Find_Primitive_Operation (N : Node_Id) return Boolean;
196 -- Find candidate interpretations for the name Obj.Proc when it appears
197 -- in a subprogram renaming declaration.
199 procedure Find_Unary_Types
203 -- Unary arithmetic types: plus, minus, abs
205 procedure Check_Arithmetic_Pair
209 -- Subsidiary procedure to Find_Arithmetic_Types. T1 and T2 are valid
210 -- types for left and right operand. Determine whether they constitute
211 -- a valid pair for the given operator, and record the corresponding
212 -- interpretation of the operator node. The node N may be an operator
213 -- node (the usual case) or a function call whose prefix is an operator
214 -- designator. In both cases Op_Id is the operator name itself.
216 procedure Diagnose_Call (N : Node_Id; Nam : Node_Id);
217 -- Give detailed information on overloaded call where none of the
218 -- interpretations match. N is the call node, Nam the designator for
219 -- the overloaded entity being called.
221 function Junk_Operand (N : Node_Id) return Boolean;
222 -- Test for an operand that is an inappropriate entity (e.g. a package
223 -- name or a label). If so, issue an error message and return True. If
224 -- the operand is not an inappropriate entity kind, return False.
226 procedure Operator_Check (N : Node_Id);
227 -- Verify that an operator has received some valid interpretation. If none
228 -- was found, determine whether a use clause would make the operation
229 -- legal. The variable Candidate_Type (defined in Sem_Type) is set for
230 -- every type compatible with the operator, even if the operator for the
231 -- type is not directly visible. The routine uses this type to emit a more
232 -- informative message.
234 function Process_Implicit_Dereference_Prefix
236 P : Node_Id) return Entity_Id;
237 -- Called when P is the prefix of an implicit dereference, denoting an
238 -- object E. The function returns the designated type of the prefix, taking
239 -- into account that the designated type of an anonymous access type may be
240 -- a limited view, when the non-limited view is visible.
241 -- If in semantics only mode (-gnatc or generic), the function also records
242 -- that the prefix is a reference to E, if any. Normally, such a reference
243 -- is generated only when the implicit dereference is expanded into an
244 -- explicit one, but for consistency we must generate the reference when
245 -- expansion is disabled as well.
247 procedure Remove_Abstract_Operations (N : Node_Id);
248 -- Ada 2005: implementation of AI-310. An abstract non-dispatching
249 -- operation is not a candidate interpretation.
251 function Try_Indexed_Call
255 Skip_First : Boolean) return Boolean;
256 -- If a function has defaults for all its actuals, a call to it may in fact
257 -- be an indexing on the result of the call. Try_Indexed_Call attempts the
258 -- interpretation as an indexing, prior to analysis as a call. If both are
259 -- possible, the node is overloaded with both interpretations (same symbol
260 -- but two different types). If the call is written in prefix form, the
261 -- prefix becomes the first parameter in the call, and only the remaining
262 -- actuals must be checked for the presence of defaults.
264 function Try_Indirect_Call
267 Typ : Entity_Id) return Boolean;
268 -- Similarly, a function F that needs no actuals can return an access to a
269 -- subprogram, and the call F (X) interpreted as F.all (X). In this case
270 -- the call may be overloaded with both interpretations.
272 function Try_Object_Operation (N : Node_Id) return Boolean;
273 -- Ada 2005 (AI-252): Support the object.operation notation. If node N
274 -- is a call in this notation, it is transformed into a normal subprogram
275 -- call where the prefix is a parameter, and True is returned. If node
276 -- N is not of this form, it is unchanged, and False is returned.
278 procedure wpo (T : Entity_Id);
279 pragma Warnings (Off, wpo);
280 -- Used for debugging: obtain list of primitive operations even if
281 -- type is not frozen and dispatch table is not built yet.
283 ------------------------
284 -- Ambiguous_Operands --
285 ------------------------
287 procedure Ambiguous_Operands (N : Node_Id) is
288 procedure List_Operand_Interps (Opnd : Node_Id);
290 --------------------------
291 -- List_Operand_Interps --
292 --------------------------
294 procedure List_Operand_Interps (Opnd : Node_Id) is
299 if Is_Overloaded (Opnd) then
300 if Nkind (Opnd) in N_Op then
302 elsif Nkind (Opnd) = N_Function_Call then
312 if Opnd = Left_Opnd (N) then
313 Error_Msg_N ("\left operand has the following interpretations", N);
316 ("\right operand has the following interpretations", N);
320 List_Interps (Nam, Err);
321 end List_Operand_Interps;
323 -- Start of processing for Ambiguous_Operands
326 if Nkind (N) in N_Membership_Test then
327 Error_Msg_N ("ambiguous operands for membership", N);
329 elsif Nkind_In (N, N_Op_Eq, N_Op_Ne) then
330 Error_Msg_N ("ambiguous operands for equality", N);
333 Error_Msg_N ("ambiguous operands for comparison", N);
336 if All_Errors_Mode then
337 List_Operand_Interps (Left_Opnd (N));
338 List_Operand_Interps (Right_Opnd (N));
340 Error_Msg_N ("\use -gnatf switch for details", N);
342 end Ambiguous_Operands;
344 -----------------------
345 -- Analyze_Aggregate --
346 -----------------------
348 -- Most of the analysis of Aggregates requires that the type be known,
349 -- and is therefore put off until resolution.
351 procedure Analyze_Aggregate (N : Node_Id) is
353 if No (Etype (N)) then
354 Set_Etype (N, Any_Composite);
356 end Analyze_Aggregate;
358 -----------------------
359 -- Analyze_Allocator --
360 -----------------------
362 procedure Analyze_Allocator (N : Node_Id) is
363 Loc : constant Source_Ptr := Sloc (N);
364 Sav_Errs : constant Nat := Serious_Errors_Detected;
365 E : Node_Id := Expression (N);
366 Acc_Type : Entity_Id;
372 -- Allocator is not allowed in SPARK or ALFA
374 if Formal_Verification_Mode then
375 Error_Msg_F ("|~~allocator is not allowed", N);
378 -- Proceed with analysis
380 -- Deal with allocator restrictions
382 -- In accordance with H.4(7), the No_Allocators restriction only applies
383 -- to user-written allocators. The same consideration applies to the
384 -- No_Allocators_Before_Elaboration restriction.
386 if Comes_From_Source (N) then
387 Check_Restriction (No_Allocators, N);
389 -- Processing for No_Allocators_After_Elaboration, loop to look at
390 -- enclosing context, checking task case and main subprogram case.
394 while Present (P) loop
396 -- In both cases we need a handled sequence of statements, where
397 -- the occurrence of the allocator is within the statements.
399 if Nkind (P) = N_Handled_Sequence_Of_Statements
400 and then Is_List_Member (C)
401 and then List_Containing (C) = Statements (P)
403 -- Check for allocator within task body, this is a definite
404 -- violation of No_Allocators_After_Elaboration we can detect.
406 if Nkind (Original_Node (Parent (P))) = N_Task_Body then
407 Check_Restriction (No_Allocators_After_Elaboration, N);
411 -- The other case is appearance in a subprogram body. This may
412 -- be a violation if this is a library level subprogram, and it
413 -- turns out to be used as the main program, but only the
414 -- binder knows that, so just record the occurrence.
416 if Nkind (Original_Node (Parent (P))) = N_Subprogram_Body
417 and then Nkind (Parent (Parent (P))) = N_Compilation_Unit
419 Set_Has_Allocator (Current_Sem_Unit);
428 -- Analyze the allocator
430 if Nkind (E) = N_Qualified_Expression then
431 Acc_Type := Create_Itype (E_Allocator_Type, N);
432 Set_Etype (Acc_Type, Acc_Type);
433 Find_Type (Subtype_Mark (E));
435 -- Analyze the qualified expression, and apply the name resolution
436 -- rule given in 4.7 (3).
439 Type_Id := Etype (E);
440 Set_Directly_Designated_Type (Acc_Type, Type_Id);
442 Resolve (Expression (E), Type_Id);
444 if Is_Limited_Type (Type_Id)
445 and then Comes_From_Source (N)
446 and then not In_Instance_Body
448 if not OK_For_Limited_Init (Type_Id, Expression (E)) then
449 Error_Msg_N ("initialization not allowed for limited types", N);
450 Explain_Limited_Type (Type_Id, N);
454 -- A qualified expression requires an exact match of the type,
455 -- class-wide matching is not allowed.
457 -- if Is_Class_Wide_Type (Type_Id)
458 -- and then Base_Type
459 -- (Etype (Expression (E))) /= Base_Type (Type_Id)
461 -- Wrong_Type (Expression (E), Type_Id);
464 Check_Non_Static_Context (Expression (E));
466 -- We don't analyze the qualified expression itself because it's
467 -- part of the allocator
469 Set_Etype (E, Type_Id);
471 -- Case where allocator has a subtype indication
476 Base_Typ : Entity_Id;
479 -- If the allocator includes a N_Subtype_Indication then a
480 -- constraint is present, otherwise the node is a subtype mark.
481 -- Introduce an explicit subtype declaration into the tree
482 -- defining some anonymous subtype and rewrite the allocator to
483 -- use this subtype rather than the subtype indication.
485 -- It is important to introduce the explicit subtype declaration
486 -- so that the bounds of the subtype indication are attached to
487 -- the tree in case the allocator is inside a generic unit.
489 if Nkind (E) = N_Subtype_Indication then
491 -- A constraint is only allowed for a composite type in Ada
492 -- 95. In Ada 83, a constraint is also allowed for an
493 -- access-to-composite type, but the constraint is ignored.
495 Find_Type (Subtype_Mark (E));
496 Base_Typ := Entity (Subtype_Mark (E));
498 if Is_Elementary_Type (Base_Typ) then
499 if not (Ada_Version = Ada_83
500 and then Is_Access_Type (Base_Typ))
502 Error_Msg_N ("constraint not allowed here", E);
504 if Nkind (Constraint (E)) =
505 N_Index_Or_Discriminant_Constraint
507 Error_Msg_N -- CODEFIX
508 ("\if qualified expression was meant, " &
509 "use apostrophe", Constraint (E));
513 -- Get rid of the bogus constraint:
515 Rewrite (E, New_Copy_Tree (Subtype_Mark (E)));
516 Analyze_Allocator (N);
519 -- Ada 2005, AI-363: if the designated type has a constrained
520 -- partial view, it cannot receive a discriminant constraint,
521 -- and the allocated object is unconstrained.
523 elsif Ada_Version >= Ada_2005
524 and then Has_Constrained_Partial_View (Base_Typ)
527 ("constraint no allowed when type " &
528 "has a constrained partial view", Constraint (E));
531 if Expander_Active then
532 Def_Id := Make_Temporary (Loc, 'S');
535 Make_Subtype_Declaration (Loc,
536 Defining_Identifier => Def_Id,
537 Subtype_Indication => Relocate_Node (E)));
539 if Sav_Errs /= Serious_Errors_Detected
540 and then Nkind (Constraint (E)) =
541 N_Index_Or_Discriminant_Constraint
543 Error_Msg_N -- CODEFIX
544 ("if qualified expression was meant, " &
545 "use apostrophe!", Constraint (E));
548 E := New_Occurrence_Of (Def_Id, Loc);
549 Rewrite (Expression (N), E);
553 Type_Id := Process_Subtype (E, N);
554 Acc_Type := Create_Itype (E_Allocator_Type, N);
555 Set_Etype (Acc_Type, Acc_Type);
556 Set_Directly_Designated_Type (Acc_Type, Type_Id);
557 Check_Fully_Declared (Type_Id, N);
559 -- Ada 2005 (AI-231): If the designated type is itself an access
560 -- type that excludes null, its default initialization will
561 -- be a null object, and we can insert an unconditional raise
562 -- before the allocator.
564 -- Ada 2012 (AI-104): A not null indication here is altogether
567 if Can_Never_Be_Null (Type_Id) then
569 Not_Null_Check : constant Node_Id :=
570 Make_Raise_Constraint_Error (Sloc (E),
571 Reason => CE_Null_Not_Allowed);
574 if Ada_Version >= Ada_2012 then
576 ("an uninitialized allocator cannot have"
577 & " a null exclusion", N);
579 elsif Expander_Active then
580 Insert_Action (N, Not_Null_Check);
581 Analyze (Not_Null_Check);
584 Error_Msg_N ("null value not allowed here?", E);
589 -- Check restriction against dynamically allocated protected
590 -- objects. Note that when limited aggregates are supported,
591 -- a similar test should be applied to an allocator with a
592 -- qualified expression ???
594 if Is_Protected_Type (Type_Id) then
595 Check_Restriction (No_Protected_Type_Allocators, N);
598 -- Check for missing initialization. Skip this check if we already
599 -- had errors on analyzing the allocator, since in that case these
600 -- are probably cascaded errors.
602 if Is_Indefinite_Subtype (Type_Id)
603 and then Serious_Errors_Detected = Sav_Errs
605 if Is_Class_Wide_Type (Type_Id) then
607 ("initialization required in class-wide allocation", N);
609 if Ada_Version < Ada_2005
610 and then Is_Limited_Type (Type_Id)
612 Error_Msg_N ("unconstrained allocation not allowed", N);
614 if Is_Array_Type (Type_Id) then
616 ("\constraint with array bounds required", N);
618 elsif Has_Unknown_Discriminants (Type_Id) then
621 else pragma Assert (Has_Discriminants (Type_Id));
623 ("\constraint with discriminant values required", N);
626 -- Limited Ada 2005 and general non-limited case
630 ("uninitialized unconstrained allocation not allowed",
633 if Is_Array_Type (Type_Id) then
635 ("\qualified expression or constraint with " &
636 "array bounds required", N);
638 elsif Has_Unknown_Discriminants (Type_Id) then
639 Error_Msg_N ("\qualified expression required", N);
641 else pragma Assert (Has_Discriminants (Type_Id));
643 ("\qualified expression or constraint with " &
644 "discriminant values required", N);
652 if Is_Abstract_Type (Type_Id) then
653 Error_Msg_N ("cannot allocate abstract object", E);
656 if Has_Task (Designated_Type (Acc_Type)) then
657 Check_Restriction (No_Tasking, N);
658 Check_Restriction (Max_Tasks, N);
659 Check_Restriction (No_Task_Allocators, N);
661 -- Check that an allocator with task parts isn't for a nested access
662 -- type when restriction No_Task_Hierarchy applies.
664 if not Is_Library_Level_Entity (Acc_Type) then
665 Check_Restriction (No_Task_Hierarchy, N);
669 -- Check that an allocator of a nested access type doesn't create a
670 -- protected object when restriction No_Local_Protected_Objects applies.
671 -- We don't have an equivalent to Has_Task for protected types, so only
672 -- cases where the designated type itself is a protected type are
673 -- currently checked. ???
675 if Is_Protected_Type (Designated_Type (Acc_Type))
676 and then not Is_Library_Level_Entity (Acc_Type)
678 Check_Restriction (No_Local_Protected_Objects, N);
681 -- If the No_Streams restriction is set, check that the type of the
682 -- object is not, and does not contain, any subtype derived from
683 -- Ada.Streams.Root_Stream_Type. Note that we guard the call to
684 -- Has_Stream just for efficiency reasons. There is no point in
685 -- spending time on a Has_Stream check if the restriction is not set.
687 if Restriction_Check_Required (No_Streams) then
688 if Has_Stream (Designated_Type (Acc_Type)) then
689 Check_Restriction (No_Streams, N);
693 Set_Etype (N, Acc_Type);
695 if not Is_Library_Level_Entity (Acc_Type) then
696 Check_Restriction (No_Local_Allocators, N);
699 if Serious_Errors_Detected > Sav_Errs then
700 Set_Error_Posted (N);
701 Set_Etype (N, Any_Type);
703 end Analyze_Allocator;
705 ---------------------------
706 -- Analyze_Arithmetic_Op --
707 ---------------------------
709 procedure Analyze_Arithmetic_Op (N : Node_Id) is
710 L : constant Node_Id := Left_Opnd (N);
711 R : constant Node_Id := Right_Opnd (N);
715 Candidate_Type := Empty;
716 Analyze_Expression (L);
717 Analyze_Expression (R);
719 -- If the entity is already set, the node is the instantiation of a
720 -- generic node with a non-local reference, or was manufactured by a
721 -- call to Make_Op_xxx. In either case the entity is known to be valid,
722 -- and we do not need to collect interpretations, instead we just get
723 -- the single possible interpretation.
727 if Present (Op_Id) then
728 if Ekind (Op_Id) = E_Operator then
730 if Nkind_In (N, N_Op_Divide, N_Op_Mod, N_Op_Multiply, N_Op_Rem)
731 and then Treat_Fixed_As_Integer (N)
735 Set_Etype (N, Any_Type);
736 Find_Arithmetic_Types (L, R, Op_Id, N);
740 Set_Etype (N, Any_Type);
741 Add_One_Interp (N, Op_Id, Etype (Op_Id));
744 -- Entity is not already set, so we do need to collect interpretations
747 Op_Id := Get_Name_Entity_Id (Chars (N));
748 Set_Etype (N, Any_Type);
750 while Present (Op_Id) loop
751 if Ekind (Op_Id) = E_Operator
752 and then Present (Next_Entity (First_Entity (Op_Id)))
754 Find_Arithmetic_Types (L, R, Op_Id, N);
756 -- The following may seem superfluous, because an operator cannot
757 -- be generic, but this ignores the cleverness of the author of
760 elsif Is_Overloadable (Op_Id) then
761 Analyze_User_Defined_Binary_Op (N, Op_Id);
764 Op_Id := Homonym (Op_Id);
769 end Analyze_Arithmetic_Op;
775 -- Function, procedure, and entry calls are checked here. The Name in
776 -- the call may be overloaded. The actuals have been analyzed and may
777 -- themselves be overloaded. On exit from this procedure, the node N
778 -- may have zero, one or more interpretations. In the first case an
779 -- error message is produced. In the last case, the node is flagged
780 -- as overloaded and the interpretations are collected in All_Interp.
782 -- If the name is an Access_To_Subprogram, it cannot be overloaded, but
783 -- the type-checking is similar to that of other calls.
785 procedure Analyze_Call (N : Node_Id) is
786 Actuals : constant List_Id := Parameter_Associations (N);
791 Success : Boolean := False;
793 Deref : Boolean := False;
794 -- Flag indicates whether an interpretation of the prefix is a
795 -- parameterless call that returns an access_to_subprogram.
797 function Name_Denotes_Function return Boolean;
798 -- If the type of the name is an access to subprogram, this may be the
799 -- type of a name, or the return type of the function being called. If
800 -- the name is not an entity then it can denote a protected function.
801 -- Until we distinguish Etype from Return_Type, we must use this routine
802 -- to resolve the meaning of the name in the call.
804 procedure No_Interpretation;
805 -- Output error message when no valid interpretation exists
807 ---------------------------
808 -- Name_Denotes_Function --
809 ---------------------------
811 function Name_Denotes_Function return Boolean is
813 if Is_Entity_Name (Nam) then
814 return Ekind (Entity (Nam)) = E_Function;
816 elsif Nkind (Nam) = N_Selected_Component then
817 return Ekind (Entity (Selector_Name (Nam))) = E_Function;
822 end Name_Denotes_Function;
824 -----------------------
825 -- No_Interpretation --
826 -----------------------
828 procedure No_Interpretation is
829 L : constant Boolean := Is_List_Member (N);
830 K : constant Node_Kind := Nkind (Parent (N));
833 -- If the node is in a list whose parent is not an expression then it
834 -- must be an attempted procedure call.
836 if L and then K not in N_Subexpr then
837 if Ekind (Entity (Nam)) = E_Generic_Procedure then
839 ("must instantiate generic procedure& before call",
843 ("procedure or entry name expected", Nam);
846 -- Check for tasking cases where only an entry call will do
849 and then Nkind_In (K, N_Entry_Call_Alternative,
850 N_Triggering_Alternative)
852 Error_Msg_N ("entry name expected", Nam);
854 -- Otherwise give general error message
857 Error_Msg_N ("invalid prefix in call", Nam);
859 end No_Interpretation;
861 -- Start of processing for Analyze_Call
864 -- Initialize the type of the result of the call to the error type,
865 -- which will be reset if the type is successfully resolved.
867 Set_Etype (N, Any_Type);
871 if not Is_Overloaded (Nam) then
873 -- Only one interpretation to check
875 if Ekind (Etype (Nam)) = E_Subprogram_Type then
876 Nam_Ent := Etype (Nam);
878 -- If the prefix is an access_to_subprogram, this may be an indirect
879 -- call. This is the case if the name in the call is not an entity
880 -- name, or if it is a function name in the context of a procedure
881 -- call. In this latter case, we have a call to a parameterless
882 -- function that returns a pointer_to_procedure which is the entity
883 -- being called. Finally, F (X) may be a call to a parameterless
884 -- function that returns a pointer to a function with parameters.
886 elsif Is_Access_Type (Etype (Nam))
887 and then Ekind (Designated_Type (Etype (Nam))) = E_Subprogram_Type
889 (not Name_Denotes_Function
890 or else Nkind (N) = N_Procedure_Call_Statement
892 (Nkind (Parent (N)) /= N_Explicit_Dereference
893 and then Is_Entity_Name (Nam)
894 and then No (First_Formal (Entity (Nam)))
895 and then Present (Actuals)))
897 Nam_Ent := Designated_Type (Etype (Nam));
898 Insert_Explicit_Dereference (Nam);
900 -- Selected component case. Simple entry or protected operation,
901 -- where the entry name is given by the selector name.
903 elsif Nkind (Nam) = N_Selected_Component then
904 Nam_Ent := Entity (Selector_Name (Nam));
906 if not Ekind_In (Nam_Ent, E_Entry,
911 Error_Msg_N ("name in call is not a callable entity", Nam);
912 Set_Etype (N, Any_Type);
916 -- If the name is an Indexed component, it can be a call to a member
917 -- of an entry family. The prefix must be a selected component whose
918 -- selector is the entry. Analyze_Procedure_Call normalizes several
919 -- kinds of call into this form.
921 elsif Nkind (Nam) = N_Indexed_Component then
922 if Nkind (Prefix (Nam)) = N_Selected_Component then
923 Nam_Ent := Entity (Selector_Name (Prefix (Nam)));
925 Error_Msg_N ("name in call is not a callable entity", Nam);
926 Set_Etype (N, Any_Type);
930 elsif not Is_Entity_Name (Nam) then
931 Error_Msg_N ("name in call is not a callable entity", Nam);
932 Set_Etype (N, Any_Type);
936 Nam_Ent := Entity (Nam);
938 -- If no interpretations, give error message
940 if not Is_Overloadable (Nam_Ent) then
946 -- Operations generated for RACW stub types are called only through
947 -- dispatching, and can never be the static interpretation of a call.
949 if Is_RACW_Stub_Type_Operation (Nam_Ent) then
954 Analyze_One_Call (N, Nam_Ent, True, Success);
956 -- If this is an indirect call, the return type of the access_to
957 -- subprogram may be an incomplete type. At the point of the call,
958 -- use the full type if available, and at the same time update the
959 -- return type of the access_to_subprogram.
962 and then Nkind (Nam) = N_Explicit_Dereference
963 and then Ekind (Etype (N)) = E_Incomplete_Type
964 and then Present (Full_View (Etype (N)))
966 Set_Etype (N, Full_View (Etype (N)));
967 Set_Etype (Nam_Ent, Etype (N));
971 -- An overloaded selected component must denote overloaded operations
972 -- of a concurrent type. The interpretations are attached to the
973 -- simple name of those operations.
975 if Nkind (Nam) = N_Selected_Component then
976 Nam := Selector_Name (Nam);
979 Get_First_Interp (Nam, X, It);
981 while Present (It.Nam) loop
985 -- Name may be call that returns an access to subprogram, or more
986 -- generally an overloaded expression one of whose interpretations
987 -- yields an access to subprogram. If the name is an entity, we do
988 -- not dereference, because the node is a call that returns the
989 -- access type: note difference between f(x), where the call may
990 -- return an access subprogram type, and f(x)(y), where the type
991 -- returned by the call to f is implicitly dereferenced to analyze
994 if Is_Access_Type (Nam_Ent) then
995 Nam_Ent := Designated_Type (Nam_Ent);
997 elsif Is_Access_Type (Etype (Nam_Ent))
999 (not Is_Entity_Name (Nam)
1000 or else Nkind (N) = N_Procedure_Call_Statement)
1001 and then Ekind (Designated_Type (Etype (Nam_Ent)))
1004 Nam_Ent := Designated_Type (Etype (Nam_Ent));
1006 if Is_Entity_Name (Nam) then
1011 -- If the call has been rewritten from a prefixed call, the first
1012 -- parameter has been analyzed, but may need a subsequent
1013 -- dereference, so skip its analysis now.
1015 if N /= Original_Node (N)
1016 and then Nkind (Original_Node (N)) = Nkind (N)
1017 and then Nkind (Name (N)) /= Nkind (Name (Original_Node (N)))
1018 and then Present (Parameter_Associations (N))
1019 and then Present (Etype (First (Parameter_Associations (N))))
1022 (N, Nam_Ent, False, Success, Skip_First => True);
1024 Analyze_One_Call (N, Nam_Ent, False, Success);
1027 -- If the interpretation succeeds, mark the proper type of the
1028 -- prefix (any valid candidate will do). If not, remove the
1029 -- candidate interpretation. This only needs to be done for
1030 -- overloaded protected operations, for other entities disambi-
1031 -- guation is done directly in Resolve.
1035 and then Nkind (Parent (N)) /= N_Explicit_Dereference
1037 Set_Entity (Nam, It.Nam);
1038 Insert_Explicit_Dereference (Nam);
1039 Set_Etype (Nam, Nam_Ent);
1042 Set_Etype (Nam, It.Typ);
1045 elsif Nkind_In (Name (N), N_Selected_Component,
1051 Get_Next_Interp (X, It);
1054 -- If the name is the result of a function call, it can only
1055 -- be a call to a function returning an access to subprogram.
1056 -- Insert explicit dereference.
1058 if Nkind (Nam) = N_Function_Call then
1059 Insert_Explicit_Dereference (Nam);
1062 if Etype (N) = Any_Type then
1064 -- None of the interpretations is compatible with the actuals
1066 Diagnose_Call (N, Nam);
1068 -- Special checks for uninstantiated put routines
1070 if Nkind (N) = N_Procedure_Call_Statement
1071 and then Is_Entity_Name (Nam)
1072 and then Chars (Nam) = Name_Put
1073 and then List_Length (Actuals) = 1
1076 Arg : constant Node_Id := First (Actuals);
1080 if Nkind (Arg) = N_Parameter_Association then
1081 Typ := Etype (Explicit_Actual_Parameter (Arg));
1086 if Is_Signed_Integer_Type (Typ) then
1088 ("possible missing instantiation of " &
1089 "'Text_'I'O.'Integer_'I'O!", Nam);
1091 elsif Is_Modular_Integer_Type (Typ) then
1093 ("possible missing instantiation of " &
1094 "'Text_'I'O.'Modular_'I'O!", Nam);
1096 elsif Is_Floating_Point_Type (Typ) then
1098 ("possible missing instantiation of " &
1099 "'Text_'I'O.'Float_'I'O!", Nam);
1101 elsif Is_Ordinary_Fixed_Point_Type (Typ) then
1103 ("possible missing instantiation of " &
1104 "'Text_'I'O.'Fixed_'I'O!", Nam);
1106 elsif Is_Decimal_Fixed_Point_Type (Typ) then
1108 ("possible missing instantiation of " &
1109 "'Text_'I'O.'Decimal_'I'O!", Nam);
1111 elsif Is_Enumeration_Type (Typ) then
1113 ("possible missing instantiation of " &
1114 "'Text_'I'O.'Enumeration_'I'O!", Nam);
1119 elsif not Is_Overloaded (N)
1120 and then Is_Entity_Name (Nam)
1122 -- Resolution yields a single interpretation. Verify that the
1123 -- reference has capitalization consistent with the declaration.
1125 Set_Entity_With_Style_Check (Nam, Entity (Nam));
1126 Generate_Reference (Entity (Nam), Nam);
1128 Set_Etype (Nam, Etype (Entity (Nam)));
1130 Remove_Abstract_Operations (N);
1137 -----------------------------
1138 -- Analyze_Case_Expression --
1139 -----------------------------
1141 procedure Analyze_Case_Expression (N : Node_Id) is
1142 Expr : constant Node_Id := Expression (N);
1143 FirstX : constant Node_Id := Expression (First (Alternatives (N)));
1145 Exp_Type : Entity_Id;
1146 Exp_Btype : Entity_Id;
1148 Dont_Care : Boolean;
1149 Others_Present : Boolean;
1151 procedure Non_Static_Choice_Error (Choice : Node_Id);
1152 -- Error routine invoked by the generic instantiation below when
1153 -- the case expression has a non static choice.
1155 package Case_Choices_Processing is new
1156 Generic_Choices_Processing
1157 (Get_Alternatives => Alternatives,
1158 Get_Choices => Discrete_Choices,
1159 Process_Empty_Choice => No_OP,
1160 Process_Non_Static_Choice => Non_Static_Choice_Error,
1161 Process_Associated_Node => No_OP);
1162 use Case_Choices_Processing;
1164 -----------------------------
1165 -- Non_Static_Choice_Error --
1166 -----------------------------
1168 procedure Non_Static_Choice_Error (Choice : Node_Id) is
1170 Flag_Non_Static_Expr
1171 ("choice given in case expression is not static!", Choice);
1172 end Non_Static_Choice_Error;
1174 -- Start of processing for Analyze_Case_Expression
1177 if Comes_From_Source (N) then
1178 Check_Compiler_Unit (N);
1181 Analyze_And_Resolve (Expr, Any_Discrete);
1182 Check_Unset_Reference (Expr);
1183 Exp_Type := Etype (Expr);
1184 Exp_Btype := Base_Type (Exp_Type);
1186 Alt := First (Alternatives (N));
1187 while Present (Alt) loop
1188 Analyze (Expression (Alt));
1192 if not Is_Overloaded (FirstX) then
1193 Set_Etype (N, Etype (FirstX));
1201 Set_Etype (N, Any_Type);
1203 Get_First_Interp (FirstX, I, It);
1204 while Present (It.Nam) loop
1206 -- For each interpretation of the first expression, we only
1207 -- add the interpretation if every other expression in the
1208 -- case expression alternatives has a compatible type.
1210 Alt := Next (First (Alternatives (N)));
1211 while Present (Alt) loop
1212 exit when not Has_Compatible_Type (Expression (Alt), It.Typ);
1217 Add_One_Interp (N, It.Typ, It.Typ);
1220 Get_Next_Interp (I, It);
1225 Exp_Btype := Base_Type (Exp_Type);
1227 -- The expression must be of a discrete type which must be determinable
1228 -- independently of the context in which the expression occurs, but
1229 -- using the fact that the expression must be of a discrete type.
1230 -- Moreover, the type this expression must not be a character literal
1231 -- (which is always ambiguous).
1233 -- If error already reported by Resolve, nothing more to do
1235 if Exp_Btype = Any_Discrete
1236 or else Exp_Btype = Any_Type
1240 elsif Exp_Btype = Any_Character then
1242 ("character literal as case expression is ambiguous", Expr);
1246 -- If the case expression is a formal object of mode in out, then
1247 -- treat it as having a nonstatic subtype by forcing use of the base
1248 -- type (which has to get passed to Check_Case_Choices below). Also
1249 -- use base type when the case expression is parenthesized.
1251 if Paren_Count (Expr) > 0
1252 or else (Is_Entity_Name (Expr)
1253 and then Ekind (Entity (Expr)) = E_Generic_In_Out_Parameter)
1255 Exp_Type := Exp_Btype;
1258 -- Call instantiated Analyze_Choices which does the rest of the work
1260 Analyze_Choices (N, Exp_Type, Dont_Care, Others_Present);
1262 if Exp_Type = Universal_Integer and then not Others_Present then
1264 ("case on universal integer requires OTHERS choice", Expr);
1266 end Analyze_Case_Expression;
1268 ---------------------------
1269 -- Analyze_Comparison_Op --
1270 ---------------------------
1272 procedure Analyze_Comparison_Op (N : Node_Id) is
1273 L : constant Node_Id := Left_Opnd (N);
1274 R : constant Node_Id := Right_Opnd (N);
1275 Op_Id : Entity_Id := Entity (N);
1278 Set_Etype (N, Any_Type);
1279 Candidate_Type := Empty;
1281 Analyze_Expression (L);
1282 Analyze_Expression (R);
1284 if Present (Op_Id) then
1285 if Ekind (Op_Id) = E_Operator then
1286 Find_Comparison_Types (L, R, Op_Id, N);
1288 Add_One_Interp (N, Op_Id, Etype (Op_Id));
1291 if Is_Overloaded (L) then
1292 Set_Etype (L, Intersect_Types (L, R));
1296 Op_Id := Get_Name_Entity_Id (Chars (N));
1297 while Present (Op_Id) loop
1298 if Ekind (Op_Id) = E_Operator then
1299 Find_Comparison_Types (L, R, Op_Id, N);
1301 Analyze_User_Defined_Binary_Op (N, Op_Id);
1304 Op_Id := Homonym (Op_Id);
1309 end Analyze_Comparison_Op;
1311 ---------------------------
1312 -- Analyze_Concatenation --
1313 ---------------------------
1315 procedure Analyze_Concatenation (N : Node_Id) is
1317 -- We wish to avoid deep recursion, because concatenations are often
1318 -- deeply nested, as in A&B&...&Z. Therefore, we walk down the left
1319 -- operands nonrecursively until we find something that is not a
1320 -- concatenation (A in this case), or has already been analyzed. We
1321 -- analyze that, and then walk back up the tree following Parent
1322 -- pointers, calling Analyze_Concatenation_Rest to do the rest of the
1323 -- work at each level. The Parent pointers allow us to avoid recursion,
1324 -- and thus avoid running out of memory.
1330 Candidate_Type := Empty;
1332 -- The following code is equivalent to:
1334 -- Set_Etype (N, Any_Type);
1335 -- Analyze_Expression (Left_Opnd (N));
1336 -- Analyze_Concatenation_Rest (N);
1338 -- where the Analyze_Expression call recurses back here if the left
1339 -- operand is a concatenation.
1341 -- Walk down left operands
1344 Set_Etype (NN, Any_Type);
1345 L := Left_Opnd (NN);
1346 exit when Nkind (L) /= N_Op_Concat or else Analyzed (L);
1350 -- Now (given the above example) NN is A&B and L is A
1352 -- First analyze L ...
1354 Analyze_Expression (L);
1356 -- ... then walk NN back up until we reach N (where we started), calling
1357 -- Analyze_Concatenation_Rest along the way.
1360 Analyze_Concatenation_Rest (NN);
1364 end Analyze_Concatenation;
1366 --------------------------------
1367 -- Analyze_Concatenation_Rest --
1368 --------------------------------
1370 -- If the only one-dimensional array type in scope is String,
1371 -- this is the resulting type of the operation. Otherwise there
1372 -- will be a concatenation operation defined for each user-defined
1373 -- one-dimensional array.
1375 procedure Analyze_Concatenation_Rest (N : Node_Id) is
1376 L : constant Node_Id := Left_Opnd (N);
1377 R : constant Node_Id := Right_Opnd (N);
1378 Op_Id : Entity_Id := Entity (N);
1383 Analyze_Expression (R);
1385 -- If the entity is present, the node appears in an instance, and
1386 -- denotes a predefined concatenation operation. The resulting type is
1387 -- obtained from the arguments when possible. If the arguments are
1388 -- aggregates, the array type and the concatenation type must be
1391 if Present (Op_Id) then
1392 if Ekind (Op_Id) = E_Operator then
1393 LT := Base_Type (Etype (L));
1394 RT := Base_Type (Etype (R));
1396 if Is_Array_Type (LT)
1397 and then (RT = LT or else RT = Base_Type (Component_Type (LT)))
1399 Add_One_Interp (N, Op_Id, LT);
1401 elsif Is_Array_Type (RT)
1402 and then LT = Base_Type (Component_Type (RT))
1404 Add_One_Interp (N, Op_Id, RT);
1406 -- If one operand is a string type or a user-defined array type,
1407 -- and the other is a literal, result is of the specific type.
1410 (Root_Type (LT) = Standard_String
1411 or else Scope (LT) /= Standard_Standard)
1412 and then Etype (R) = Any_String
1414 Add_One_Interp (N, Op_Id, LT);
1417 (Root_Type (RT) = Standard_String
1418 or else Scope (RT) /= Standard_Standard)
1419 and then Etype (L) = Any_String
1421 Add_One_Interp (N, Op_Id, RT);
1423 elsif not Is_Generic_Type (Etype (Op_Id)) then
1424 Add_One_Interp (N, Op_Id, Etype (Op_Id));
1427 -- Type and its operations must be visible
1429 Set_Entity (N, Empty);
1430 Analyze_Concatenation (N);
1434 Add_One_Interp (N, Op_Id, Etype (Op_Id));
1438 Op_Id := Get_Name_Entity_Id (Name_Op_Concat);
1439 while Present (Op_Id) loop
1440 if Ekind (Op_Id) = E_Operator then
1442 -- Do not consider operators declared in dead code, they can
1443 -- not be part of the resolution.
1445 if Is_Eliminated (Op_Id) then
1448 Find_Concatenation_Types (L, R, Op_Id, N);
1452 Analyze_User_Defined_Binary_Op (N, Op_Id);
1455 Op_Id := Homonym (Op_Id);
1460 end Analyze_Concatenation_Rest;
1462 ------------------------------------
1463 -- Analyze_Conditional_Expression --
1464 ------------------------------------
1466 procedure Analyze_Conditional_Expression (N : Node_Id) is
1467 Condition : constant Node_Id := First (Expressions (N));
1468 Then_Expr : constant Node_Id := Next (Condition);
1469 Else_Expr : Node_Id;
1472 -- Defend against error of missing expressions from previous error
1474 if No (Then_Expr) then
1478 -- Conditional expression is not allowed in SPARK or ALFA
1480 if Formal_Verification_Mode then
1481 Error_Msg_F ("|~~conditional expression is not allowed", N);
1484 -- Proceed with analysis
1486 Else_Expr := Next (Then_Expr);
1488 if Comes_From_Source (N) then
1489 Check_Compiler_Unit (N);
1492 Analyze_Expression (Condition);
1493 Analyze_Expression (Then_Expr);
1495 if Present (Else_Expr) then
1496 Analyze_Expression (Else_Expr);
1499 -- If then expression not overloaded, then that decides the type
1501 if not Is_Overloaded (Then_Expr) then
1502 Set_Etype (N, Etype (Then_Expr));
1504 -- Case where then expression is overloaded
1512 Set_Etype (N, Any_Type);
1514 -- Shouldn't the following statement be down in the ELSE of the
1515 -- following loop? ???
1517 Get_First_Interp (Then_Expr, I, It);
1519 -- if no Else_Expression the conditional must be boolean
1521 if No (Else_Expr) then
1522 Set_Etype (N, Standard_Boolean);
1524 -- Else_Expression Present. For each possible intepretation of
1525 -- the Then_Expression, add it only if the Else_Expression has
1526 -- a compatible type.
1529 while Present (It.Nam) loop
1530 if Has_Compatible_Type (Else_Expr, It.Typ) then
1531 Add_One_Interp (N, It.Typ, It.Typ);
1534 Get_Next_Interp (I, It);
1539 end Analyze_Conditional_Expression;
1541 -------------------------
1542 -- Analyze_Equality_Op --
1543 -------------------------
1545 procedure Analyze_Equality_Op (N : Node_Id) is
1546 Loc : constant Source_Ptr := Sloc (N);
1547 L : constant Node_Id := Left_Opnd (N);
1548 R : constant Node_Id := Right_Opnd (N);
1552 Set_Etype (N, Any_Type);
1553 Candidate_Type := Empty;
1555 Analyze_Expression (L);
1556 Analyze_Expression (R);
1558 -- If the entity is set, the node is a generic instance with a non-local
1559 -- reference to the predefined operator or to a user-defined function.
1560 -- It can also be an inequality that is expanded into the negation of a
1561 -- call to a user-defined equality operator.
1563 -- For the predefined case, the result is Boolean, regardless of the
1564 -- type of the operands. The operands may even be limited, if they are
1565 -- generic actuals. If they are overloaded, label the left argument with
1566 -- the common type that must be present, or with the type of the formal
1567 -- of the user-defined function.
1569 if Present (Entity (N)) then
1570 Op_Id := Entity (N);
1572 if Ekind (Op_Id) = E_Operator then
1573 Add_One_Interp (N, Op_Id, Standard_Boolean);
1575 Add_One_Interp (N, Op_Id, Etype (Op_Id));
1578 if Is_Overloaded (L) then
1579 if Ekind (Op_Id) = E_Operator then
1580 Set_Etype (L, Intersect_Types (L, R));
1582 Set_Etype (L, Etype (First_Formal (Op_Id)));
1587 Op_Id := Get_Name_Entity_Id (Chars (N));
1588 while Present (Op_Id) loop
1589 if Ekind (Op_Id) = E_Operator then
1590 Find_Equality_Types (L, R, Op_Id, N);
1592 Analyze_User_Defined_Binary_Op (N, Op_Id);
1595 Op_Id := Homonym (Op_Id);
1599 -- If there was no match, and the operator is inequality, this may
1600 -- be a case where inequality has not been made explicit, as for
1601 -- tagged types. Analyze the node as the negation of an equality
1602 -- operation. This cannot be done earlier, because before analysis
1603 -- we cannot rule out the presence of an explicit inequality.
1605 if Etype (N) = Any_Type
1606 and then Nkind (N) = N_Op_Ne
1608 Op_Id := Get_Name_Entity_Id (Name_Op_Eq);
1609 while Present (Op_Id) loop
1610 if Ekind (Op_Id) = E_Operator then
1611 Find_Equality_Types (L, R, Op_Id, N);
1613 Analyze_User_Defined_Binary_Op (N, Op_Id);
1616 Op_Id := Homonym (Op_Id);
1619 if Etype (N) /= Any_Type then
1620 Op_Id := Entity (N);
1626 Left_Opnd => Left_Opnd (N),
1627 Right_Opnd => Right_Opnd (N))));
1629 Set_Entity (Right_Opnd (N), Op_Id);
1635 end Analyze_Equality_Op;
1637 ----------------------------------
1638 -- Analyze_Explicit_Dereference --
1639 ----------------------------------
1641 procedure Analyze_Explicit_Dereference (N : Node_Id) is
1642 Loc : constant Source_Ptr := Sloc (N);
1643 P : constant Node_Id := Prefix (N);
1649 function Is_Function_Type return Boolean;
1650 -- Check whether node may be interpreted as an implicit function call
1652 ----------------------
1653 -- Is_Function_Type --
1654 ----------------------
1656 function Is_Function_Type return Boolean is
1661 if not Is_Overloaded (N) then
1662 return Ekind (Base_Type (Etype (N))) = E_Subprogram_Type
1663 and then Etype (Base_Type (Etype (N))) /= Standard_Void_Type;
1666 Get_First_Interp (N, I, It);
1667 while Present (It.Nam) loop
1668 if Ekind (Base_Type (It.Typ)) /= E_Subprogram_Type
1669 or else Etype (Base_Type (It.Typ)) = Standard_Void_Type
1674 Get_Next_Interp (I, It);
1679 end Is_Function_Type;
1681 -- Start of processing for Analyze_Explicit_Dereference
1684 -- Explicit dereference is not allowed in SPARK or ALFA
1686 if Formal_Verification_Mode then
1687 Error_Msg_F ("|~~explicit dereference is not allowed", N);
1690 -- Proceed with analysis
1693 Set_Etype (N, Any_Type);
1695 -- Test for remote access to subprogram type, and if so return
1696 -- after rewriting the original tree.
1698 if Remote_AST_E_Dereference (P) then
1702 -- Normal processing for other than remote access to subprogram type
1704 if not Is_Overloaded (P) then
1705 if Is_Access_Type (Etype (P)) then
1707 -- Set the Etype. We need to go through Is_For_Access_Subtypes to
1708 -- avoid other problems caused by the Private_Subtype and it is
1709 -- safe to go to the Base_Type because this is the same as
1710 -- converting the access value to its Base_Type.
1713 DT : Entity_Id := Designated_Type (Etype (P));
1716 if Ekind (DT) = E_Private_Subtype
1717 and then Is_For_Access_Subtype (DT)
1719 DT := Base_Type (DT);
1722 -- An explicit dereference is a legal occurrence of an
1723 -- incomplete type imported through a limited_with clause,
1724 -- if the full view is visible.
1726 if From_With_Type (DT)
1727 and then not From_With_Type (Scope (DT))
1729 (Is_Immediately_Visible (Scope (DT))
1731 (Is_Child_Unit (Scope (DT))
1732 and then Is_Visible_Child_Unit (Scope (DT))))
1734 Set_Etype (N, Available_View (DT));
1741 elsif Etype (P) /= Any_Type then
1742 Error_Msg_N ("prefix of dereference must be an access type", N);
1747 Get_First_Interp (P, I, It);
1748 while Present (It.Nam) loop
1751 if Is_Access_Type (T) then
1752 Add_One_Interp (N, Designated_Type (T), Designated_Type (T));
1755 Get_Next_Interp (I, It);
1758 -- Error if no interpretation of the prefix has an access type
1760 if Etype (N) = Any_Type then
1762 ("access type required in prefix of explicit dereference", P);
1763 Set_Etype (N, Any_Type);
1769 and then Nkind (Parent (N)) /= N_Indexed_Component
1771 and then (Nkind (Parent (N)) /= N_Function_Call
1772 or else N /= Name (Parent (N)))
1774 and then (Nkind (Parent (N)) /= N_Procedure_Call_Statement
1775 or else N /= Name (Parent (N)))
1777 and then Nkind (Parent (N)) /= N_Subprogram_Renaming_Declaration
1778 and then (Nkind (Parent (N)) /= N_Attribute_Reference
1780 (Attribute_Name (Parent (N)) /= Name_Address
1782 Attribute_Name (Parent (N)) /= Name_Access))
1784 -- Name is a function call with no actuals, in a context that
1785 -- requires deproceduring (including as an actual in an enclosing
1786 -- function or procedure call). There are some pathological cases
1787 -- where the prefix might include functions that return access to
1788 -- subprograms and others that return a regular type. Disambiguation
1789 -- of those has to take place in Resolve.
1792 Make_Function_Call (Loc,
1793 Name => Make_Explicit_Dereference (Loc, P),
1794 Parameter_Associations => New_List);
1796 -- If the prefix is overloaded, remove operations that have formals,
1797 -- we know that this is a parameterless call.
1799 if Is_Overloaded (P) then
1800 Get_First_Interp (P, I, It);
1801 while Present (It.Nam) loop
1804 if No (First_Formal (Base_Type (Designated_Type (T)))) then
1810 Get_Next_Interp (I, It);
1817 elsif not Is_Function_Type
1818 and then Is_Overloaded (N)
1820 -- The prefix may include access to subprograms and other access
1821 -- types. If the context selects the interpretation that is a
1822 -- function call (not a procedure call) we cannot rewrite the node
1823 -- yet, but we include the result of the call interpretation.
1825 Get_First_Interp (N, I, It);
1826 while Present (It.Nam) loop
1827 if Ekind (Base_Type (It.Typ)) = E_Subprogram_Type
1828 and then Etype (Base_Type (It.Typ)) /= Standard_Void_Type
1829 and then Nkind (Parent (N)) /= N_Procedure_Call_Statement
1831 Add_One_Interp (N, Etype (It.Typ), Etype (It.Typ));
1834 Get_Next_Interp (I, It);
1838 -- A value of remote access-to-class-wide must not be dereferenced
1841 Validate_Remote_Access_To_Class_Wide_Type (N);
1842 end Analyze_Explicit_Dereference;
1844 ------------------------
1845 -- Analyze_Expression --
1846 ------------------------
1848 procedure Analyze_Expression (N : Node_Id) is
1851 Check_Parameterless_Call (N);
1852 end Analyze_Expression;
1854 -------------------------------------
1855 -- Analyze_Expression_With_Actions --
1856 -------------------------------------
1858 procedure Analyze_Expression_With_Actions (N : Node_Id) is
1862 A := First (Actions (N));
1869 Analyze_Expression (Expression (N));
1870 Set_Etype (N, Etype (Expression (N)));
1871 end Analyze_Expression_With_Actions;
1873 ------------------------------------
1874 -- Analyze_Indexed_Component_Form --
1875 ------------------------------------
1877 procedure Analyze_Indexed_Component_Form (N : Node_Id) is
1878 P : constant Node_Id := Prefix (N);
1879 Exprs : constant List_Id := Expressions (N);
1885 procedure Process_Function_Call;
1886 -- Prefix in indexed component form is an overloadable entity,
1887 -- so the node is a function call. Reformat it as such.
1889 procedure Process_Indexed_Component;
1890 -- Prefix in indexed component form is actually an indexed component.
1891 -- This routine processes it, knowing that the prefix is already
1894 procedure Process_Indexed_Component_Or_Slice;
1895 -- An indexed component with a single index may designate a slice if
1896 -- the index is a subtype mark. This routine disambiguates these two
1897 -- cases by resolving the prefix to see if it is a subtype mark.
1899 procedure Process_Overloaded_Indexed_Component;
1900 -- If the prefix of an indexed component is overloaded, the proper
1901 -- interpretation is selected by the index types and the context.
1903 ---------------------------
1904 -- Process_Function_Call --
1905 ---------------------------
1907 procedure Process_Function_Call is
1911 Change_Node (N, N_Function_Call);
1913 Set_Parameter_Associations (N, Exprs);
1915 -- Analyze actuals prior to analyzing the call itself
1917 Actual := First (Parameter_Associations (N));
1918 while Present (Actual) loop
1920 Check_Parameterless_Call (Actual);
1922 -- Move to next actual. Note that we use Next, not Next_Actual
1923 -- here. The reason for this is a bit subtle. If a function call
1924 -- includes named associations, the parser recognizes the node as
1925 -- a call, and it is analyzed as such. If all associations are
1926 -- positional, the parser builds an indexed_component node, and
1927 -- it is only after analysis of the prefix that the construct
1928 -- is recognized as a call, in which case Process_Function_Call
1929 -- rewrites the node and analyzes the actuals. If the list of
1930 -- actuals is malformed, the parser may leave the node as an
1931 -- indexed component (despite the presence of named associations).
1932 -- The iterator Next_Actual is equivalent to Next if the list is
1933 -- positional, but follows the normalized chain of actuals when
1934 -- named associations are present. In this case normalization has
1935 -- not taken place, and actuals remain unanalyzed, which leads to
1936 -- subsequent crashes or loops if there is an attempt to continue
1937 -- analysis of the program.
1943 end Process_Function_Call;
1945 -------------------------------
1946 -- Process_Indexed_Component --
1947 -------------------------------
1949 procedure Process_Indexed_Component is
1951 Array_Type : Entity_Id;
1953 Pent : Entity_Id := Empty;
1956 Exp := First (Exprs);
1958 if Is_Overloaded (P) then
1959 Process_Overloaded_Indexed_Component;
1962 Array_Type := Etype (P);
1964 if Is_Entity_Name (P) then
1966 elsif Nkind (P) = N_Selected_Component
1967 and then Is_Entity_Name (Selector_Name (P))
1969 Pent := Entity (Selector_Name (P));
1972 -- Prefix must be appropriate for an array type, taking into
1973 -- account a possible implicit dereference.
1975 if Is_Access_Type (Array_Type) then
1976 Error_Msg_NW (Warn_On_Dereference, "?implicit dereference", N);
1977 Array_Type := Process_Implicit_Dereference_Prefix (Pent, P);
1980 if Is_Array_Type (Array_Type) then
1983 elsif Present (Pent) and then Ekind (Pent) = E_Entry_Family then
1985 Set_Etype (N, Any_Type);
1987 if not Has_Compatible_Type
1988 (Exp, Entry_Index_Type (Pent))
1990 Error_Msg_N ("invalid index type in entry name", N);
1992 elsif Present (Next (Exp)) then
1993 Error_Msg_N ("too many subscripts in entry reference", N);
1996 Set_Etype (N, Etype (P));
2001 elsif Is_Record_Type (Array_Type)
2002 and then Remote_AST_I_Dereference (P)
2006 elsif Array_Type = Any_Type then
2007 Set_Etype (N, Any_Type);
2009 -- In most cases the analysis of the prefix will have emitted
2010 -- an error already, but if the prefix may be interpreted as a
2011 -- call in prefixed notation, the report is left to the caller.
2012 -- To prevent cascaded errors, report only if no previous ones.
2014 if Serious_Errors_Detected = 0 then
2015 Error_Msg_N ("invalid prefix in indexed component", P);
2017 if Nkind (P) = N_Expanded_Name then
2018 Error_Msg_NE ("\& is not visible", P, Selector_Name (P));
2024 -- Here we definitely have a bad indexing
2027 if Nkind (Parent (N)) = N_Requeue_Statement
2028 and then Present (Pent) and then Ekind (Pent) = E_Entry
2031 ("REQUEUE does not permit parameters", First (Exprs));
2033 elsif Is_Entity_Name (P)
2034 and then Etype (P) = Standard_Void_Type
2036 Error_Msg_NE ("incorrect use of&", P, Entity (P));
2039 Error_Msg_N ("array type required in indexed component", P);
2042 Set_Etype (N, Any_Type);
2046 Index := First_Index (Array_Type);
2047 while Present (Index) and then Present (Exp) loop
2048 if not Has_Compatible_Type (Exp, Etype (Index)) then
2049 Wrong_Type (Exp, Etype (Index));
2050 Set_Etype (N, Any_Type);
2058 Set_Etype (N, Component_Type (Array_Type));
2060 if Present (Index) then
2062 ("too few subscripts in array reference", First (Exprs));
2064 elsif Present (Exp) then
2065 Error_Msg_N ("too many subscripts in array reference", Exp);
2068 end Process_Indexed_Component;
2070 ----------------------------------------
2071 -- Process_Indexed_Component_Or_Slice --
2072 ----------------------------------------
2074 procedure Process_Indexed_Component_Or_Slice is
2076 Exp := First (Exprs);
2077 while Present (Exp) loop
2078 Analyze_Expression (Exp);
2082 Exp := First (Exprs);
2084 -- If one index is present, and it is a subtype name, then the
2085 -- node denotes a slice (note that the case of an explicit range
2086 -- for a slice was already built as an N_Slice node in the first
2087 -- place, so that case is not handled here).
2089 -- We use a replace rather than a rewrite here because this is one
2090 -- of the cases in which the tree built by the parser is plain wrong.
2093 and then Is_Entity_Name (Exp)
2094 and then Is_Type (Entity (Exp))
2097 Make_Slice (Sloc (N),
2099 Discrete_Range => New_Copy (Exp)));
2102 -- Otherwise (more than one index present, or single index is not
2103 -- a subtype name), then we have the indexed component case.
2106 Process_Indexed_Component;
2108 end Process_Indexed_Component_Or_Slice;
2110 ------------------------------------------
2111 -- Process_Overloaded_Indexed_Component --
2112 ------------------------------------------
2114 procedure Process_Overloaded_Indexed_Component is
2123 Set_Etype (N, Any_Type);
2125 Get_First_Interp (P, I, It);
2126 while Present (It.Nam) loop
2129 if Is_Access_Type (Typ) then
2130 Typ := Designated_Type (Typ);
2131 Error_Msg_NW (Warn_On_Dereference, "?implicit dereference", N);
2134 if Is_Array_Type (Typ) then
2136 -- Got a candidate: verify that index types are compatible
2138 Index := First_Index (Typ);
2140 Exp := First (Exprs);
2141 while Present (Index) and then Present (Exp) loop
2142 if Has_Compatible_Type (Exp, Etype (Index)) then
2154 if Found and then No (Index) and then No (Exp) then
2156 Etype (Component_Type (Typ)),
2157 Etype (Component_Type (Typ)));
2161 Get_Next_Interp (I, It);
2164 if Etype (N) = Any_Type then
2165 Error_Msg_N ("no legal interpretation for indexed component", N);
2166 Set_Is_Overloaded (N, False);
2170 end Process_Overloaded_Indexed_Component;
2172 -- Start of processing for Analyze_Indexed_Component_Form
2175 -- Get name of array, function or type
2179 if Nkind_In (N, N_Function_Call, N_Procedure_Call_Statement) then
2181 -- If P is an explicit dereference whose prefix is of a
2182 -- remote access-to-subprogram type, then N has already
2183 -- been rewritten as a subprogram call and analyzed.
2188 pragma Assert (Nkind (N) = N_Indexed_Component);
2190 P_T := Base_Type (Etype (P));
2192 if Is_Entity_Name (P) and then Present (Entity (P)) then
2195 if Is_Type (U_N) then
2197 -- Reformat node as a type conversion
2199 E := Remove_Head (Exprs);
2201 if Present (First (Exprs)) then
2203 ("argument of type conversion must be single expression", N);
2206 Change_Node (N, N_Type_Conversion);
2207 Set_Subtype_Mark (N, P);
2209 Set_Expression (N, E);
2211 -- After changing the node, call for the specific Analysis
2212 -- routine directly, to avoid a double call to the expander.
2214 Analyze_Type_Conversion (N);
2218 if Is_Overloadable (U_N) then
2219 Process_Function_Call;
2221 elsif Ekind (Etype (P)) = E_Subprogram_Type
2222 or else (Is_Access_Type (Etype (P))
2224 Ekind (Designated_Type (Etype (P))) =
2227 -- Call to access_to-subprogram with possible implicit dereference
2229 Process_Function_Call;
2231 elsif Is_Generic_Subprogram (U_N) then
2233 -- A common beginner's (or C++ templates fan) error
2235 Error_Msg_N ("generic subprogram cannot be called", N);
2236 Set_Etype (N, Any_Type);
2240 Process_Indexed_Component_Or_Slice;
2243 -- If not an entity name, prefix is an expression that may denote
2244 -- an array or an access-to-subprogram.
2247 if Ekind (P_T) = E_Subprogram_Type
2248 or else (Is_Access_Type (P_T)
2250 Ekind (Designated_Type (P_T)) = E_Subprogram_Type)
2252 Process_Function_Call;
2254 elsif Nkind (P) = N_Selected_Component
2255 and then Is_Overloadable (Entity (Selector_Name (P)))
2257 Process_Function_Call;
2260 -- Indexed component, slice, or a call to a member of a family
2261 -- entry, which will be converted to an entry call later.
2263 Process_Indexed_Component_Or_Slice;
2266 end Analyze_Indexed_Component_Form;
2268 ------------------------
2269 -- Analyze_Logical_Op --
2270 ------------------------
2272 procedure Analyze_Logical_Op (N : Node_Id) is
2273 L : constant Node_Id := Left_Opnd (N);
2274 R : constant Node_Id := Right_Opnd (N);
2275 Op_Id : Entity_Id := Entity (N);
2278 Set_Etype (N, Any_Type);
2279 Candidate_Type := Empty;
2281 Analyze_Expression (L);
2282 Analyze_Expression (R);
2284 if Present (Op_Id) then
2286 if Ekind (Op_Id) = E_Operator then
2287 Find_Boolean_Types (L, R, Op_Id, N);
2289 Add_One_Interp (N, Op_Id, Etype (Op_Id));
2293 Op_Id := Get_Name_Entity_Id (Chars (N));
2294 while Present (Op_Id) loop
2295 if Ekind (Op_Id) = E_Operator then
2296 Find_Boolean_Types (L, R, Op_Id, N);
2298 Analyze_User_Defined_Binary_Op (N, Op_Id);
2301 Op_Id := Homonym (Op_Id);
2306 end Analyze_Logical_Op;
2308 ---------------------------
2309 -- Analyze_Membership_Op --
2310 ---------------------------
2312 procedure Analyze_Membership_Op (N : Node_Id) is
2313 Loc : constant Source_Ptr := Sloc (N);
2314 L : constant Node_Id := Left_Opnd (N);
2315 R : constant Node_Id := Right_Opnd (N);
2317 Index : Interp_Index;
2319 Found : Boolean := False;
2323 procedure Try_One_Interp (T1 : Entity_Id);
2324 -- Routine to try one proposed interpretation. Note that the context
2325 -- of the operation plays no role in resolving the arguments, so that
2326 -- if there is more than one interpretation of the operands that is
2327 -- compatible with a membership test, the operation is ambiguous.
2329 --------------------
2330 -- Try_One_Interp --
2331 --------------------
2333 procedure Try_One_Interp (T1 : Entity_Id) is
2335 if Has_Compatible_Type (R, T1) then
2337 and then Base_Type (T1) /= Base_Type (T_F)
2339 It := Disambiguate (L, I_F, Index, Any_Type);
2341 if It = No_Interp then
2342 Ambiguous_Operands (N);
2343 Set_Etype (L, Any_Type);
2360 procedure Analyze_Set_Membership;
2361 -- If a set of alternatives is present, analyze each and find the
2362 -- common type to which they must all resolve.
2364 ----------------------------
2365 -- Analyze_Set_Membership --
2366 ----------------------------
2368 procedure Analyze_Set_Membership is
2370 Index : Interp_Index;
2372 Candidate_Interps : Node_Id;
2373 Common_Type : Entity_Id := Empty;
2377 Candidate_Interps := L;
2379 if not Is_Overloaded (L) then
2380 Common_Type := Etype (L);
2382 Alt := First (Alternatives (N));
2383 while Present (Alt) loop
2386 if not Has_Compatible_Type (Alt, Common_Type) then
2387 Wrong_Type (Alt, Common_Type);
2394 Alt := First (Alternatives (N));
2395 while Present (Alt) loop
2397 if not Is_Overloaded (Alt) then
2398 Common_Type := Etype (Alt);
2401 Get_First_Interp (Alt, Index, It);
2402 while Present (It.Typ) loop
2404 Has_Compatible_Type (Candidate_Interps, It.Typ)
2406 Remove_Interp (Index);
2409 Get_Next_Interp (Index, It);
2412 Get_First_Interp (Alt, Index, It);
2415 Error_Msg_N ("alternative has no legal type", Alt);
2419 -- If alternative is not overloaded, we have a unique type
2422 Set_Etype (Alt, It.Typ);
2423 Get_Next_Interp (Index, It);
2426 Set_Is_Overloaded (Alt, False);
2427 Common_Type := Etype (Alt);
2430 Candidate_Interps := Alt;
2437 Set_Etype (N, Standard_Boolean);
2439 if Present (Common_Type) then
2440 Set_Etype (L, Common_Type);
2441 Set_Is_Overloaded (L, False);
2444 Error_Msg_N ("cannot resolve membership operation", N);
2446 end Analyze_Set_Membership;
2448 -- Start of processing for Analyze_Membership_Op
2451 Analyze_Expression (L);
2454 and then Ada_Version >= Ada_2012
2456 Analyze_Set_Membership;
2460 if Nkind (R) = N_Range
2461 or else (Nkind (R) = N_Attribute_Reference
2462 and then Attribute_Name (R) = Name_Range)
2466 if not Is_Overloaded (L) then
2467 Try_One_Interp (Etype (L));
2470 Get_First_Interp (L, Index, It);
2471 while Present (It.Typ) loop
2472 Try_One_Interp (It.Typ);
2473 Get_Next_Interp (Index, It);
2477 -- If not a range, it can be a subtype mark, or else it is a degenerate
2478 -- membership test with a singleton value, i.e. a test for equality.
2482 if Is_Entity_Name (R)
2483 and then Is_Type (Entity (R))
2486 Check_Fully_Declared (Entity (R), R);
2488 elsif Ada_Version >= Ada_2012 then
2489 if Nkind (N) = N_In then
2505 -- In previous version of the language this is an error that will
2506 -- be diagnosed below.
2512 -- Compatibility between expression and subtype mark or range is
2513 -- checked during resolution. The result of the operation is Boolean
2516 Set_Etype (N, Standard_Boolean);
2518 if Comes_From_Source (N)
2519 and then Present (Right_Opnd (N))
2520 and then Is_CPP_Class (Etype (Etype (Right_Opnd (N))))
2522 Error_Msg_N ("membership test not applicable to cpp-class types", N);
2524 end Analyze_Membership_Op;
2526 ----------------------
2527 -- Analyze_Negation --
2528 ----------------------
2530 procedure Analyze_Negation (N : Node_Id) is
2531 R : constant Node_Id := Right_Opnd (N);
2532 Op_Id : Entity_Id := Entity (N);
2535 Set_Etype (N, Any_Type);
2536 Candidate_Type := Empty;
2538 Analyze_Expression (R);
2540 if Present (Op_Id) then
2541 if Ekind (Op_Id) = E_Operator then
2542 Find_Negation_Types (R, Op_Id, N);
2544 Add_One_Interp (N, Op_Id, Etype (Op_Id));
2548 Op_Id := Get_Name_Entity_Id (Chars (N));
2549 while Present (Op_Id) loop
2550 if Ekind (Op_Id) = E_Operator then
2551 Find_Negation_Types (R, Op_Id, N);
2553 Analyze_User_Defined_Unary_Op (N, Op_Id);
2556 Op_Id := Homonym (Op_Id);
2561 end Analyze_Negation;
2567 procedure Analyze_Null (N : Node_Id) is
2569 -- Null is not allowed in SPARK or ALFA
2571 if Formal_Verification_Mode then
2572 Error_Msg_F ("|~~null is not allowed", N);
2575 -- Proceed with analysis
2577 Set_Etype (N, Any_Access);
2580 ----------------------
2581 -- Analyze_One_Call --
2582 ----------------------
2584 procedure Analyze_One_Call
2588 Success : out Boolean;
2589 Skip_First : Boolean := False)
2591 Actuals : constant List_Id := Parameter_Associations (N);
2592 Prev_T : constant Entity_Id := Etype (N);
2594 Must_Skip : constant Boolean := Skip_First
2595 or else Nkind (Original_Node (N)) = N_Selected_Component
2597 (Nkind (Original_Node (N)) = N_Indexed_Component
2598 and then Nkind (Prefix (Original_Node (N)))
2599 = N_Selected_Component);
2600 -- The first formal must be omitted from the match when trying to find
2601 -- a primitive operation that is a possible interpretation, and also
2602 -- after the call has been rewritten, because the corresponding actual
2603 -- is already known to be compatible, and because this may be an
2604 -- indexing of a call with default parameters.
2608 Is_Indexed : Boolean := False;
2609 Is_Indirect : Boolean := False;
2610 Subp_Type : constant Entity_Id := Etype (Nam);
2613 function Operator_Hidden_By (Fun : Entity_Id) return Boolean;
2614 -- There may be a user-defined operator that hides the current
2615 -- interpretation. We must check for this independently of the
2616 -- analysis of the call with the user-defined operation, because
2617 -- the parameter names may be wrong and yet the hiding takes place.
2618 -- This fixes a problem with ACATS test B34014O.
2620 -- When the type Address is a visible integer type, and the DEC
2621 -- system extension is visible, the predefined operator may be
2622 -- hidden as well, by one of the address operations in auxdec.
2623 -- Finally, The abstract operations on address do not hide the
2624 -- predefined operator (this is the purpose of making them abstract).
2626 procedure Indicate_Name_And_Type;
2627 -- If candidate interpretation matches, indicate name and type of
2628 -- result on call node.
2630 ----------------------------
2631 -- Indicate_Name_And_Type --
2632 ----------------------------
2634 procedure Indicate_Name_And_Type is
2636 Add_One_Interp (N, Nam, Etype (Nam));
2639 -- If the prefix of the call is a name, indicate the entity
2640 -- being called. If it is not a name, it is an expression that
2641 -- denotes an access to subprogram or else an entry or family. In
2642 -- the latter case, the name is a selected component, and the entity
2643 -- being called is noted on the selector.
2645 if not Is_Type (Nam) then
2646 if Is_Entity_Name (Name (N)) then
2647 Set_Entity (Name (N), Nam);
2649 elsif Nkind (Name (N)) = N_Selected_Component then
2650 Set_Entity (Selector_Name (Name (N)), Nam);
2654 if Debug_Flag_E and not Report then
2655 Write_Str (" Overloaded call ");
2656 Write_Int (Int (N));
2657 Write_Str (" compatible with ");
2658 Write_Int (Int (Nam));
2661 end Indicate_Name_And_Type;
2663 ------------------------
2664 -- Operator_Hidden_By --
2665 ------------------------
2667 function Operator_Hidden_By (Fun : Entity_Id) return Boolean is
2668 Act1 : constant Node_Id := First_Actual (N);
2669 Act2 : constant Node_Id := Next_Actual (Act1);
2670 Form1 : constant Entity_Id := First_Formal (Fun);
2671 Form2 : constant Entity_Id := Next_Formal (Form1);
2674 if Ekind (Fun) /= E_Function
2675 or else Is_Abstract_Subprogram (Fun)
2679 elsif not Has_Compatible_Type (Act1, Etype (Form1)) then
2682 elsif Present (Form2) then
2684 No (Act2) or else not Has_Compatible_Type (Act2, Etype (Form2))
2689 elsif Present (Act2) then
2693 -- Now we know that the arity of the operator matches the function,
2694 -- and the function call is a valid interpretation. The function
2695 -- hides the operator if it has the right signature, or if one of
2696 -- its operands is a non-abstract operation on Address when this is
2697 -- a visible integer type.
2699 return Hides_Op (Fun, Nam)
2700 or else Is_Descendent_Of_Address (Etype (Form1))
2703 and then Is_Descendent_Of_Address (Etype (Form2)));
2704 end Operator_Hidden_By;
2706 -- Start of processing for Analyze_One_Call
2711 -- If the subprogram has no formals or if all the formals have defaults,
2712 -- and the return type is an array type, the node may denote an indexing
2713 -- of the result of a parameterless call. In Ada 2005, the subprogram
2714 -- may have one non-defaulted formal, and the call may have been written
2715 -- in prefix notation, so that the rebuilt parameter list has more than
2718 if not Is_Overloadable (Nam)
2719 and then Ekind (Nam) /= E_Subprogram_Type
2720 and then Ekind (Nam) /= E_Entry_Family
2725 -- An indexing requires at least one actual
2727 if not Is_Empty_List (Actuals)
2729 (Needs_No_Actuals (Nam)
2731 (Needs_One_Actual (Nam)
2732 and then Present (Next_Actual (First (Actuals)))))
2734 if Is_Array_Type (Subp_Type) then
2735 Is_Indexed := Try_Indexed_Call (N, Nam, Subp_Type, Must_Skip);
2737 elsif Is_Access_Type (Subp_Type)
2738 and then Is_Array_Type (Designated_Type (Subp_Type))
2742 (N, Nam, Designated_Type (Subp_Type), Must_Skip);
2744 -- The prefix can also be a parameterless function that returns an
2745 -- access to subprogram, in which case this is an indirect call.
2746 -- If this succeeds, an explicit dereference is added later on,
2747 -- in Analyze_Call or Resolve_Call.
2749 elsif Is_Access_Type (Subp_Type)
2750 and then Ekind (Designated_Type (Subp_Type)) = E_Subprogram_Type
2752 Is_Indirect := Try_Indirect_Call (N, Nam, Subp_Type);
2757 -- If the call has been transformed into a slice, it is of the form
2758 -- F (Subtype) where F is parameterless. The node has been rewritten in
2759 -- Try_Indexed_Call and there is nothing else to do.
2762 and then Nkind (N) = N_Slice
2768 (N, Nam, (Report and not Is_Indexed and not Is_Indirect), Norm_OK);
2772 -- If an indirect call is a possible interpretation, indicate
2773 -- success to the caller.
2779 -- Mismatch in number or names of parameters
2781 elsif Debug_Flag_E then
2782 Write_Str (" normalization fails in call ");
2783 Write_Int (Int (N));
2784 Write_Str (" with subprogram ");
2785 Write_Int (Int (Nam));
2789 -- If the context expects a function call, discard any interpretation
2790 -- that is a procedure. If the node is not overloaded, leave as is for
2791 -- better error reporting when type mismatch is found.
2793 elsif Nkind (N) = N_Function_Call
2794 and then Is_Overloaded (Name (N))
2795 and then Ekind (Nam) = E_Procedure
2799 -- Ditto for function calls in a procedure context
2801 elsif Nkind (N) = N_Procedure_Call_Statement
2802 and then Is_Overloaded (Name (N))
2803 and then Etype (Nam) /= Standard_Void_Type
2807 elsif No (Actuals) then
2809 -- If Normalize succeeds, then there are default parameters for
2812 Indicate_Name_And_Type;
2814 elsif Ekind (Nam) = E_Operator then
2815 if Nkind (N) = N_Procedure_Call_Statement then
2819 -- This can occur when the prefix of the call is an operator
2820 -- name or an expanded name whose selector is an operator name.
2822 Analyze_Operator_Call (N, Nam);
2824 if Etype (N) /= Prev_T then
2826 -- Check that operator is not hidden by a function interpretation
2828 if Is_Overloaded (Name (N)) then
2834 Get_First_Interp (Name (N), I, It);
2835 while Present (It.Nam) loop
2836 if Operator_Hidden_By (It.Nam) then
2837 Set_Etype (N, Prev_T);
2841 Get_Next_Interp (I, It);
2846 -- If operator matches formals, record its name on the call.
2847 -- If the operator is overloaded, Resolve will select the
2848 -- correct one from the list of interpretations. The call
2849 -- node itself carries the first candidate.
2851 Set_Entity (Name (N), Nam);
2854 elsif Report and then Etype (N) = Any_Type then
2855 Error_Msg_N ("incompatible arguments for operator", N);
2859 -- Normalize_Actuals has chained the named associations in the
2860 -- correct order of the formals.
2862 Actual := First_Actual (N);
2863 Formal := First_Formal (Nam);
2865 -- If we are analyzing a call rewritten from object notation,
2866 -- skip first actual, which may be rewritten later as an
2867 -- explicit dereference.
2870 Next_Actual (Actual);
2871 Next_Formal (Formal);
2874 while Present (Actual) and then Present (Formal) loop
2875 if Nkind (Parent (Actual)) /= N_Parameter_Association
2876 or else Chars (Selector_Name (Parent (Actual))) = Chars (Formal)
2878 -- The actual can be compatible with the formal, but we must
2879 -- also check that the context is not an address type that is
2880 -- visibly an integer type, as is the case in VMS_64. In this
2881 -- case the use of literals is illegal, except in the body of
2882 -- descendents of system, where arithmetic operations on
2883 -- address are of course used.
2885 if Has_Compatible_Type (Actual, Etype (Formal))
2887 (Etype (Actual) /= Universal_Integer
2888 or else not Is_Descendent_Of_Address (Etype (Formal))
2890 Is_Predefined_File_Name
2891 (Unit_File_Name (Get_Source_Unit (N))))
2893 Next_Actual (Actual);
2894 Next_Formal (Formal);
2897 if Debug_Flag_E then
2898 Write_Str (" type checking fails in call ");
2899 Write_Int (Int (N));
2900 Write_Str (" with formal ");
2901 Write_Int (Int (Formal));
2902 Write_Str (" in subprogram ");
2903 Write_Int (Int (Nam));
2907 if Report and not Is_Indexed and not Is_Indirect then
2909 -- Ada 2005 (AI-251): Complete the error notification
2910 -- to help new Ada 2005 users.
2912 if Is_Class_Wide_Type (Etype (Formal))
2913 and then Is_Interface (Etype (Etype (Formal)))
2914 and then not Interface_Present_In_Ancestor
2915 (Typ => Etype (Actual),
2916 Iface => Etype (Etype (Formal)))
2919 ("(Ada 2005) does not implement interface }",
2920 Actual, Etype (Etype (Formal)));
2923 Wrong_Type (Actual, Etype (Formal));
2925 if Nkind (Actual) = N_Op_Eq
2926 and then Nkind (Left_Opnd (Actual)) = N_Identifier
2928 Formal := First_Formal (Nam);
2929 while Present (Formal) loop
2930 if Chars (Left_Opnd (Actual)) = Chars (Formal) then
2931 Error_Msg_N -- CODEFIX
2932 ("possible misspelling of `='>`!", Actual);
2936 Next_Formal (Formal);
2940 if All_Errors_Mode then
2941 Error_Msg_Sloc := Sloc (Nam);
2943 if Etype (Formal) = Any_Type then
2945 ("there is no legal actual parameter", Actual);
2948 if Is_Overloadable (Nam)
2949 and then Present (Alias (Nam))
2950 and then not Comes_From_Source (Nam)
2953 ("\\ =='> in call to inherited operation & #!",
2956 elsif Ekind (Nam) = E_Subprogram_Type then
2958 Access_To_Subprogram_Typ :
2959 constant Entity_Id :=
2961 (Associated_Node_For_Itype (Nam));
2964 "\\ =='> in call to dereference of &#!",
2965 Actual, Access_To_Subprogram_Typ);
2970 ("\\ =='> in call to &#!", Actual, Nam);
2980 -- Normalize_Actuals has verified that a default value exists
2981 -- for this formal. Current actual names a subsequent formal.
2983 Next_Formal (Formal);
2987 -- On exit, all actuals match
2989 Indicate_Name_And_Type;
2991 end Analyze_One_Call;
2993 ---------------------------
2994 -- Analyze_Operator_Call --
2995 ---------------------------
2997 procedure Analyze_Operator_Call (N : Node_Id; Op_Id : Entity_Id) is
2998 Op_Name : constant Name_Id := Chars (Op_Id);
2999 Act1 : constant Node_Id := First_Actual (N);
3000 Act2 : constant Node_Id := Next_Actual (Act1);
3003 -- Binary operator case
3005 if Present (Act2) then
3007 -- If more than two operands, then not binary operator after all
3009 if Present (Next_Actual (Act2)) then
3012 elsif Op_Name = Name_Op_Add
3013 or else Op_Name = Name_Op_Subtract
3014 or else Op_Name = Name_Op_Multiply
3015 or else Op_Name = Name_Op_Divide
3016 or else Op_Name = Name_Op_Mod
3017 or else Op_Name = Name_Op_Rem
3018 or else Op_Name = Name_Op_Expon
3020 Find_Arithmetic_Types (Act1, Act2, Op_Id, N);
3022 elsif Op_Name = Name_Op_And
3023 or else Op_Name = Name_Op_Or
3024 or else Op_Name = Name_Op_Xor
3026 Find_Boolean_Types (Act1, Act2, Op_Id, N);
3028 elsif Op_Name = Name_Op_Lt
3029 or else Op_Name = Name_Op_Le
3030 or else Op_Name = Name_Op_Gt
3031 or else Op_Name = Name_Op_Ge
3033 Find_Comparison_Types (Act1, Act2, Op_Id, N);
3035 elsif Op_Name = Name_Op_Eq
3036 or else Op_Name = Name_Op_Ne
3038 Find_Equality_Types (Act1, Act2, Op_Id, N);
3040 elsif Op_Name = Name_Op_Concat then
3041 Find_Concatenation_Types (Act1, Act2, Op_Id, N);
3043 -- Is this else null correct, or should it be an abort???
3049 -- Unary operator case
3052 if Op_Name = Name_Op_Subtract or else
3053 Op_Name = Name_Op_Add or else
3054 Op_Name = Name_Op_Abs
3056 Find_Unary_Types (Act1, Op_Id, N);
3059 Op_Name = Name_Op_Not
3061 Find_Negation_Types (Act1, Op_Id, N);
3063 -- Is this else null correct, or should it be an abort???
3069 end Analyze_Operator_Call;
3071 -------------------------------------------
3072 -- Analyze_Overloaded_Selected_Component --
3073 -------------------------------------------
3075 procedure Analyze_Overloaded_Selected_Component (N : Node_Id) is
3076 Nam : constant Node_Id := Prefix (N);
3077 Sel : constant Node_Id := Selector_Name (N);
3084 Set_Etype (Sel, Any_Type);
3086 Get_First_Interp (Nam, I, It);
3087 while Present (It.Typ) loop
3088 if Is_Access_Type (It.Typ) then
3089 T := Designated_Type (It.Typ);
3090 Error_Msg_NW (Warn_On_Dereference, "?implicit dereference", N);
3095 if Is_Record_Type (T) then
3097 -- If the prefix is a class-wide type, the visible components are
3098 -- those of the base type.
3100 if Is_Class_Wide_Type (T) then
3104 Comp := First_Entity (T);
3105 while Present (Comp) loop
3106 if Chars (Comp) = Chars (Sel)
3107 and then Is_Visible_Component (Comp)
3110 -- AI05-105: if the context is an object renaming with
3111 -- an anonymous access type, the expected type of the
3112 -- object must be anonymous. This is a name resolution rule.
3114 if Nkind (Parent (N)) /= N_Object_Renaming_Declaration
3115 or else No (Access_Definition (Parent (N)))
3116 or else Ekind (Etype (Comp)) = E_Anonymous_Access_Type
3118 Ekind (Etype (Comp)) = E_Anonymous_Access_Subprogram_Type
3120 Set_Entity (Sel, Comp);
3121 Set_Etype (Sel, Etype (Comp));
3122 Add_One_Interp (N, Etype (Comp), Etype (Comp));
3124 -- This also specifies a candidate to resolve the name.
3125 -- Further overloading will be resolved from context.
3126 -- The selector name itself does not carry overloading
3129 Set_Etype (Nam, It.Typ);
3132 -- Named access type in the context of a renaming
3133 -- declaration with an access definition. Remove
3134 -- inapplicable candidate.
3143 elsif Is_Concurrent_Type (T) then
3144 Comp := First_Entity (T);
3145 while Present (Comp)
3146 and then Comp /= First_Private_Entity (T)
3148 if Chars (Comp) = Chars (Sel) then
3149 if Is_Overloadable (Comp) then
3150 Add_One_Interp (Sel, Comp, Etype (Comp));
3152 Set_Entity_With_Style_Check (Sel, Comp);
3153 Generate_Reference (Comp, Sel);
3156 Set_Etype (Sel, Etype (Comp));
3157 Set_Etype (N, Etype (Comp));
3158 Set_Etype (Nam, It.Typ);
3160 -- For access type case, introduce explicit dereference for
3161 -- more uniform treatment of entry calls. Do this only once
3162 -- if several interpretations yield an access type.
3164 if Is_Access_Type (Etype (Nam))
3165 and then Nkind (Nam) /= N_Explicit_Dereference
3167 Insert_Explicit_Dereference (Nam);
3169 (Warn_On_Dereference, "?implicit dereference", N);
3176 Set_Is_Overloaded (N, Is_Overloaded (Sel));
3179 Get_Next_Interp (I, It);
3182 if Etype (N) = Any_Type
3183 and then not Try_Object_Operation (N)
3185 Error_Msg_NE ("undefined selector& for overloaded prefix", N, Sel);
3186 Set_Entity (Sel, Any_Id);
3187 Set_Etype (Sel, Any_Type);
3189 end Analyze_Overloaded_Selected_Component;
3191 ----------------------------------
3192 -- Analyze_Qualified_Expression --
3193 ----------------------------------
3195 procedure Analyze_Qualified_Expression (N : Node_Id) is
3196 Mark : constant Entity_Id := Subtype_Mark (N);
3197 Expr : constant Node_Id := Expression (N);
3203 Analyze_Expression (Expr);
3205 Set_Etype (N, Any_Type);
3210 if T = Any_Type then
3214 Check_Fully_Declared (T, N);
3216 -- If expected type is class-wide, check for exact match before
3217 -- expansion, because if the expression is a dispatching call it
3218 -- may be rewritten as explicit dereference with class-wide result.
3219 -- If expression is overloaded, retain only interpretations that
3220 -- will yield exact matches.
3222 if Is_Class_Wide_Type (T) then
3223 if not Is_Overloaded (Expr) then
3224 if Base_Type (Etype (Expr)) /= Base_Type (T) then
3225 if Nkind (Expr) = N_Aggregate then
3226 Error_Msg_N ("type of aggregate cannot be class-wide", Expr);
3228 Wrong_Type (Expr, T);
3233 Get_First_Interp (Expr, I, It);
3235 while Present (It.Nam) loop
3236 if Base_Type (It.Typ) /= Base_Type (T) then
3240 Get_Next_Interp (I, It);
3246 end Analyze_Qualified_Expression;
3248 -----------------------------------
3249 -- Analyze_Quantified_Expression --
3250 -----------------------------------
3252 procedure Analyze_Quantified_Expression (N : Node_Id) is
3253 Loc : constant Source_Ptr := Sloc (N);
3254 Ent : constant Entity_Id :=
3256 (E_Loop, Current_Scope, Sloc (N), 'L');
3261 -- Quantified expression is not allowed in SPARK or ALFA
3263 if Formal_Verification_Mode then
3264 Error_Msg_F ("|~~quantified expression is not allowed", N);
3267 -- Proceed with analysis
3269 Set_Etype (Ent, Standard_Void_Type);
3270 Set_Parent (Ent, N);
3272 if Present (Loop_Parameter_Specification (N)) then
3274 Make_Iteration_Scheme (Loc,
3275 Loop_Parameter_Specification =>
3276 Loop_Parameter_Specification (N));
3279 Make_Iteration_Scheme (Loc,
3280 Iterator_Specification =>
3281 Iterator_Specification (N));
3285 Set_Parent (Iterator, N);
3286 Analyze_Iteration_Scheme (Iterator);
3288 -- The loop specification may have been converted into an
3289 -- iterator specification during its analysis. Update the
3290 -- quantified node accordingly.
3292 if Present (Iterator_Specification (Iterator)) then
3293 Set_Iterator_Specification
3294 (N, Iterator_Specification (Iterator));
3295 Set_Loop_Parameter_Specification (N, Empty);
3298 Analyze (Condition (N));
3301 Set_Etype (N, Standard_Boolean);
3302 end Analyze_Quantified_Expression;
3308 procedure Analyze_Range (N : Node_Id) is
3309 L : constant Node_Id := Low_Bound (N);
3310 H : constant Node_Id := High_Bound (N);
3311 I1, I2 : Interp_Index;
3314 procedure Check_Common_Type (T1, T2 : Entity_Id);
3315 -- Verify the compatibility of two types, and choose the
3316 -- non universal one if the other is universal.
3318 procedure Check_High_Bound (T : Entity_Id);
3319 -- Test one interpretation of the low bound against all those
3320 -- of the high bound.
3322 procedure Check_Universal_Expression (N : Node_Id);
3323 -- In Ada83, reject bounds of a universal range that are not
3324 -- literals or entity names.
3326 -----------------------
3327 -- Check_Common_Type --
3328 -----------------------
3330 procedure Check_Common_Type (T1, T2 : Entity_Id) is
3332 if Covers (T1 => T1, T2 => T2)
3334 Covers (T1 => T2, T2 => T1)
3336 if T1 = Universal_Integer
3337 or else T1 = Universal_Real
3338 or else T1 = Any_Character
3340 Add_One_Interp (N, Base_Type (T2), Base_Type (T2));
3343 Add_One_Interp (N, T1, T1);
3346 Add_One_Interp (N, Base_Type (T1), Base_Type (T1));
3349 end Check_Common_Type;
3351 ----------------------
3352 -- Check_High_Bound --
3353 ----------------------
3355 procedure Check_High_Bound (T : Entity_Id) is
3357 if not Is_Overloaded (H) then
3358 Check_Common_Type (T, Etype (H));
3360 Get_First_Interp (H, I2, It2);
3361 while Present (It2.Typ) loop
3362 Check_Common_Type (T, It2.Typ);
3363 Get_Next_Interp (I2, It2);
3366 end Check_High_Bound;
3368 -----------------------------
3369 -- Is_Universal_Expression --
3370 -----------------------------
3372 procedure Check_Universal_Expression (N : Node_Id) is
3374 if Etype (N) = Universal_Integer
3375 and then Nkind (N) /= N_Integer_Literal
3376 and then not Is_Entity_Name (N)
3377 and then Nkind (N) /= N_Attribute_Reference
3379 Error_Msg_N ("illegal bound in discrete range", N);
3381 end Check_Universal_Expression;
3383 -- Start of processing for Analyze_Range
3386 Set_Etype (N, Any_Type);
3387 Analyze_Expression (L);
3388 Analyze_Expression (H);
3390 if Etype (L) = Any_Type or else Etype (H) = Any_Type then
3394 if not Is_Overloaded (L) then
3395 Check_High_Bound (Etype (L));
3397 Get_First_Interp (L, I1, It1);
3398 while Present (It1.Typ) loop
3399 Check_High_Bound (It1.Typ);
3400 Get_Next_Interp (I1, It1);
3404 -- If result is Any_Type, then we did not find a compatible pair
3406 if Etype (N) = Any_Type then
3407 Error_Msg_N ("incompatible types in range ", N);
3411 if Ada_Version = Ada_83
3413 (Nkind (Parent (N)) = N_Loop_Parameter_Specification
3414 or else Nkind (Parent (N)) = N_Constrained_Array_Definition)
3416 Check_Universal_Expression (L);
3417 Check_Universal_Expression (H);
3421 -----------------------
3422 -- Analyze_Reference --
3423 -----------------------
3425 procedure Analyze_Reference (N : Node_Id) is
3426 P : constant Node_Id := Prefix (N);
3429 Acc_Type : Entity_Id;
3434 -- An interesting error check, if we take the 'Reference of an object
3435 -- for which a pragma Atomic or Volatile has been given, and the type
3436 -- of the object is not Atomic or Volatile, then we are in trouble. The
3437 -- problem is that no trace of the atomic/volatile status will remain
3438 -- for the backend to respect when it deals with the resulting pointer,
3439 -- since the pointer type will not be marked atomic (it is a pointer to
3440 -- the base type of the object).
3442 -- It is not clear if that can ever occur, but in case it does, we will
3443 -- generate an error message. Not clear if this message can ever be
3444 -- generated, and pretty clear that it represents a bug if it is, still
3445 -- seems worth checking, except in CodePeer mode where we do not really
3446 -- care and don't want to bother the user.
3450 if Is_Entity_Name (P)
3451 and then Is_Object_Reference (P)
3452 and then not CodePeer_Mode
3457 if (Has_Atomic_Components (E)
3458 and then not Has_Atomic_Components (T))
3460 (Has_Volatile_Components (E)
3461 and then not Has_Volatile_Components (T))
3462 or else (Is_Atomic (E) and then not Is_Atomic (T))
3463 or else (Is_Volatile (E) and then not Is_Volatile (T))
3465 Error_Msg_N ("cannot take reference to Atomic/Volatile object", N);
3469 -- Carry on with normal processing
3471 Acc_Type := Create_Itype (E_Allocator_Type, N);
3472 Set_Etype (Acc_Type, Acc_Type);
3473 Set_Directly_Designated_Type (Acc_Type, Etype (P));
3474 Set_Etype (N, Acc_Type);
3475 end Analyze_Reference;
3477 --------------------------------
3478 -- Analyze_Selected_Component --
3479 --------------------------------
3481 -- Prefix is a record type or a task or protected type. In the latter case,
3482 -- the selector must denote a visible entry.
3484 procedure Analyze_Selected_Component (N : Node_Id) is
3485 Name : constant Node_Id := Prefix (N);
3486 Sel : constant Node_Id := Selector_Name (N);
3489 Has_Candidate : Boolean := False;
3492 Pent : Entity_Id := Empty;
3493 Prefix_Type : Entity_Id;
3495 Type_To_Use : Entity_Id;
3496 -- In most cases this is the Prefix_Type, but if the Prefix_Type is
3497 -- a class-wide type, we use its root type, whose components are
3498 -- present in the class-wide type.
3500 Is_Single_Concurrent_Object : Boolean;
3501 -- Set True if the prefix is a single task or a single protected object
3503 procedure Find_Component_In_Instance (Rec : Entity_Id);
3504 -- In an instance, a component of a private extension may not be visible
3505 -- while it was visible in the generic. Search candidate scope for a
3506 -- component with the proper identifier. This is only done if all other
3507 -- searches have failed. When the match is found (it always will be),
3508 -- the Etype of both N and Sel are set from this component, and the
3509 -- entity of Sel is set to reference this component.
3511 function Has_Mode_Conformant_Spec (Comp : Entity_Id) return Boolean;
3512 -- It is known that the parent of N denotes a subprogram call. Comp
3513 -- is an overloadable component of the concurrent type of the prefix.
3514 -- Determine whether all formals of the parent of N and Comp are mode
3515 -- conformant. If the parent node is not analyzed yet it may be an
3516 -- indexed component rather than a function call.
3518 --------------------------------
3519 -- Find_Component_In_Instance --
3520 --------------------------------
3522 procedure Find_Component_In_Instance (Rec : Entity_Id) is
3526 Comp := First_Component (Rec);
3527 while Present (Comp) loop
3528 if Chars (Comp) = Chars (Sel) then
3529 Set_Entity_With_Style_Check (Sel, Comp);
3530 Set_Etype (Sel, Etype (Comp));
3531 Set_Etype (N, Etype (Comp));
3535 Next_Component (Comp);
3538 -- This must succeed because code was legal in the generic
3540 raise Program_Error;
3541 end Find_Component_In_Instance;
3543 ------------------------------
3544 -- Has_Mode_Conformant_Spec --
3545 ------------------------------
3547 function Has_Mode_Conformant_Spec (Comp : Entity_Id) return Boolean is
3548 Comp_Param : Entity_Id;
3550 Param_Typ : Entity_Id;
3553 Comp_Param := First_Formal (Comp);
3555 if Nkind (Parent (N)) = N_Indexed_Component then
3556 Param := First (Expressions (Parent (N)));
3558 Param := First (Parameter_Associations (Parent (N)));
3561 while Present (Comp_Param)
3562 and then Present (Param)
3564 Param_Typ := Find_Parameter_Type (Param);
3566 if Present (Param_Typ)
3568 not Conforming_Types
3569 (Etype (Comp_Param), Param_Typ, Mode_Conformant)
3574 Next_Formal (Comp_Param);
3578 -- One of the specs has additional formals
3580 if Present (Comp_Param) or else Present (Param) then
3585 end Has_Mode_Conformant_Spec;
3587 -- Start of processing for Analyze_Selected_Component
3590 Set_Etype (N, Any_Type);
3592 if Is_Overloaded (Name) then
3593 Analyze_Overloaded_Selected_Component (N);
3596 elsif Etype (Name) = Any_Type then
3597 Set_Entity (Sel, Any_Id);
3598 Set_Etype (Sel, Any_Type);
3602 Prefix_Type := Etype (Name);
3605 if Is_Access_Type (Prefix_Type) then
3607 -- A RACW object can never be used as prefix of a selected component
3608 -- since that means it is dereferenced without being a controlling
3609 -- operand of a dispatching operation (RM E.2.2(16/1)). Before
3610 -- reporting an error, we must check whether this is actually a
3611 -- dispatching call in prefix form.
3613 if Is_Remote_Access_To_Class_Wide_Type (Prefix_Type)
3614 and then Comes_From_Source (N)
3616 if Try_Object_Operation (N) then
3620 ("invalid dereference of a remote access-to-class-wide value",
3624 -- Normal case of selected component applied to access type
3627 Error_Msg_NW (Warn_On_Dereference, "?implicit dereference", N);
3629 if Is_Entity_Name (Name) then
3630 Pent := Entity (Name);
3631 elsif Nkind (Name) = N_Selected_Component
3632 and then Is_Entity_Name (Selector_Name (Name))
3634 Pent := Entity (Selector_Name (Name));
3637 Prefix_Type := Process_Implicit_Dereference_Prefix (Pent, Name);
3640 -- If we have an explicit dereference of a remote access-to-class-wide
3641 -- value, then issue an error (see RM-E.2.2(16/1)). However we first
3642 -- have to check for the case of a prefix that is a controlling operand
3643 -- of a prefixed dispatching call, as the dereference is legal in that
3644 -- case. Normally this condition is checked in Validate_Remote_Access_
3645 -- To_Class_Wide_Type, but we have to defer the checking for selected
3646 -- component prefixes because of the prefixed dispatching call case.
3647 -- Note that implicit dereferences are checked for this just above.
3649 elsif Nkind (Name) = N_Explicit_Dereference
3650 and then Is_Remote_Access_To_Class_Wide_Type (Etype (Prefix (Name)))
3651 and then Comes_From_Source (N)
3653 if Try_Object_Operation (N) then
3657 ("invalid dereference of a remote access-to-class-wide value",
3662 -- (Ada 2005): if the prefix is the limited view of a type, and
3663 -- the context already includes the full view, use the full view
3664 -- in what follows, either to retrieve a component of to find
3665 -- a primitive operation. If the prefix is an explicit dereference,
3666 -- set the type of the prefix to reflect this transformation.
3667 -- If the non-limited view is itself an incomplete type, get the
3668 -- full view if available.
3670 if Is_Incomplete_Type (Prefix_Type)
3671 and then From_With_Type (Prefix_Type)
3672 and then Present (Non_Limited_View (Prefix_Type))
3674 Prefix_Type := Get_Full_View (Non_Limited_View (Prefix_Type));
3676 if Nkind (N) = N_Explicit_Dereference then
3677 Set_Etype (Prefix (N), Prefix_Type);
3680 elsif Ekind (Prefix_Type) = E_Class_Wide_Type
3681 and then From_With_Type (Prefix_Type)
3682 and then Present (Non_Limited_View (Etype (Prefix_Type)))
3685 Class_Wide_Type (Non_Limited_View (Etype (Prefix_Type)));
3687 if Nkind (N) = N_Explicit_Dereference then
3688 Set_Etype (Prefix (N), Prefix_Type);
3692 if Ekind (Prefix_Type) = E_Private_Subtype then
3693 Prefix_Type := Base_Type (Prefix_Type);
3696 Type_To_Use := Prefix_Type;
3698 -- For class-wide types, use the entity list of the root type. This
3699 -- indirection is specially important for private extensions because
3700 -- only the root type get switched (not the class-wide type).
3702 if Is_Class_Wide_Type (Prefix_Type) then
3703 Type_To_Use := Root_Type (Prefix_Type);
3706 -- If the prefix is a single concurrent object, use its name in error
3707 -- messages, rather than that of its anonymous type.
3709 Is_Single_Concurrent_Object :=
3710 Is_Concurrent_Type (Prefix_Type)
3711 and then Is_Internal_Name (Chars (Prefix_Type))
3712 and then not Is_Derived_Type (Prefix_Type)
3713 and then Is_Entity_Name (Name);
3715 Comp := First_Entity (Type_To_Use);
3717 -- If the selector has an original discriminant, the node appears in
3718 -- an instance. Replace the discriminant with the corresponding one
3719 -- in the current discriminated type. For nested generics, this must
3720 -- be done transitively, so note the new original discriminant.
3722 if Nkind (Sel) = N_Identifier
3723 and then Present (Original_Discriminant (Sel))
3725 Comp := Find_Corresponding_Discriminant (Sel, Prefix_Type);
3727 -- Mark entity before rewriting, for completeness and because
3728 -- subsequent semantic checks might examine the original node.
3730 Set_Entity (Sel, Comp);
3731 Rewrite (Selector_Name (N),
3732 New_Occurrence_Of (Comp, Sloc (N)));
3733 Set_Original_Discriminant (Selector_Name (N), Comp);
3734 Set_Etype (N, Etype (Comp));
3736 if Is_Access_Type (Etype (Name)) then
3737 Insert_Explicit_Dereference (Name);
3738 Error_Msg_NW (Warn_On_Dereference, "?implicit dereference", N);
3741 elsif Is_Record_Type (Prefix_Type) then
3743 -- Find component with given name
3745 while Present (Comp) loop
3746 if Chars (Comp) = Chars (Sel)
3747 and then Is_Visible_Component (Comp)
3749 Set_Entity_With_Style_Check (Sel, Comp);
3750 Set_Etype (Sel, Etype (Comp));
3752 if Ekind (Comp) = E_Discriminant then
3753 if Is_Unchecked_Union (Base_Type (Prefix_Type)) then
3755 ("cannot reference discriminant of Unchecked_Union",
3759 if Is_Generic_Type (Prefix_Type)
3761 Is_Generic_Type (Root_Type (Prefix_Type))
3763 Set_Original_Discriminant (Sel, Comp);
3767 -- Resolve the prefix early otherwise it is not possible to
3768 -- build the actual subtype of the component: it may need
3769 -- to duplicate this prefix and duplication is only allowed
3770 -- on fully resolved expressions.
3774 -- Ada 2005 (AI-50217): Check wrong use of incomplete types or
3775 -- subtypes in a package specification.
3778 -- limited with Pkg;
3780 -- type Acc_Inc is access Pkg.T;
3782 -- N : Natural := X.all.Comp; -- ERROR, limited view
3783 -- end Pkg; -- Comp is not visible
3785 if Nkind (Name) = N_Explicit_Dereference
3786 and then From_With_Type (Etype (Prefix (Name)))
3787 and then not Is_Potentially_Use_Visible (Etype (Name))
3788 and then Nkind (Parent (Cunit_Entity (Current_Sem_Unit))) =
3789 N_Package_Specification
3792 ("premature usage of incomplete}", Prefix (Name),
3793 Etype (Prefix (Name)));
3796 -- We never need an actual subtype for the case of a selection
3797 -- for a indexed component of a non-packed array, since in
3798 -- this case gigi generates all the checks and can find the
3799 -- necessary bounds information.
3801 -- We also do not need an actual subtype for the case of a
3802 -- first, last, length, or range attribute applied to a
3803 -- non-packed array, since gigi can again get the bounds in
3804 -- these cases (gigi cannot handle the packed case, since it
3805 -- has the bounds of the packed array type, not the original
3806 -- bounds of the type). However, if the prefix is itself a
3807 -- selected component, as in a.b.c (i), gigi may regard a.b.c
3808 -- as a dynamic-sized temporary, so we do generate an actual
3809 -- subtype for this case.
3811 Parent_N := Parent (N);
3813 if not Is_Packed (Etype (Comp))
3815 ((Nkind (Parent_N) = N_Indexed_Component
3816 and then Nkind (Name) /= N_Selected_Component)
3818 (Nkind (Parent_N) = N_Attribute_Reference
3819 and then (Attribute_Name (Parent_N) = Name_First
3821 Attribute_Name (Parent_N) = Name_Last
3823 Attribute_Name (Parent_N) = Name_Length
3825 Attribute_Name (Parent_N) = Name_Range)))
3827 Set_Etype (N, Etype (Comp));
3829 -- If full analysis is not enabled, we do not generate an
3830 -- actual subtype, because in the absence of expansion
3831 -- reference to a formal of a protected type, for example,
3832 -- will not be properly transformed, and will lead to
3833 -- out-of-scope references in gigi.
3835 -- In all other cases, we currently build an actual subtype.
3836 -- It seems likely that many of these cases can be avoided,
3837 -- but right now, the front end makes direct references to the
3838 -- bounds (e.g. in generating a length check), and if we do
3839 -- not make an actual subtype, we end up getting a direct
3840 -- reference to a discriminant, which will not do.
3842 elsif Full_Analysis then
3844 Build_Actual_Subtype_Of_Component (Etype (Comp), N);
3845 Insert_Action (N, Act_Decl);
3847 if No (Act_Decl) then
3848 Set_Etype (N, Etype (Comp));
3851 -- Component type depends on discriminants. Enter the
3852 -- main attributes of the subtype.
3855 Subt : constant Entity_Id :=
3856 Defining_Identifier (Act_Decl);
3859 Set_Etype (Subt, Base_Type (Etype (Comp)));
3860 Set_Ekind (Subt, Ekind (Etype (Comp)));
3861 Set_Etype (N, Subt);
3865 -- If Full_Analysis not enabled, just set the Etype
3868 Set_Etype (N, Etype (Comp));
3874 -- If the prefix is a private extension, check only the visible
3875 -- components of the partial view. This must include the tag,
3876 -- which can appear in expanded code in a tag check.
3878 if Ekind (Type_To_Use) = E_Record_Type_With_Private
3879 and then Chars (Selector_Name (N)) /= Name_uTag
3881 exit when Comp = Last_Entity (Type_To_Use);
3887 -- Ada 2005 (AI-252): The selected component can be interpreted as
3888 -- a prefixed view of a subprogram. Depending on the context, this is
3889 -- either a name that can appear in a renaming declaration, or part
3890 -- of an enclosing call given in prefix form.
3892 -- Ada 2005 (AI05-0030): In the case of dispatching requeue, the
3893 -- selected component should resolve to a name.
3895 if Ada_Version >= Ada_2005
3896 and then Is_Tagged_Type (Prefix_Type)
3897 and then not Is_Concurrent_Type (Prefix_Type)
3899 if Nkind (Parent (N)) = N_Generic_Association
3900 or else Nkind (Parent (N)) = N_Requeue_Statement
3901 or else Nkind (Parent (N)) = N_Subprogram_Renaming_Declaration
3903 if Find_Primitive_Operation (N) then
3907 elsif Try_Object_Operation (N) then
3911 -- If the transformation fails, it will be necessary to redo the
3912 -- analysis with all errors enabled, to indicate candidate
3913 -- interpretations and reasons for each failure ???
3917 elsif Is_Private_Type (Prefix_Type) then
3919 -- Allow access only to discriminants of the type. If the type has
3920 -- no full view, gigi uses the parent type for the components, so we
3921 -- do the same here.
3923 if No (Full_View (Prefix_Type)) then
3924 Type_To_Use := Root_Type (Base_Type (Prefix_Type));
3925 Comp := First_Entity (Type_To_Use);
3928 while Present (Comp) loop
3929 if Chars (Comp) = Chars (Sel) then
3930 if Ekind (Comp) = E_Discriminant then
3931 Set_Entity_With_Style_Check (Sel, Comp);
3932 Generate_Reference (Comp, Sel);
3934 Set_Etype (Sel, Etype (Comp));
3935 Set_Etype (N, Etype (Comp));
3937 if Is_Generic_Type (Prefix_Type)
3938 or else Is_Generic_Type (Root_Type (Prefix_Type))
3940 Set_Original_Discriminant (Sel, Comp);
3943 -- Before declaring an error, check whether this is tagged
3944 -- private type and a call to a primitive operation.
3946 elsif Ada_Version >= Ada_2005
3947 and then Is_Tagged_Type (Prefix_Type)
3948 and then Try_Object_Operation (N)
3953 Error_Msg_Node_2 := First_Subtype (Prefix_Type);
3954 Error_Msg_NE ("invisible selector& for }", N, Sel);
3955 Set_Entity (Sel, Any_Id);
3956 Set_Etype (N, Any_Type);
3965 elsif Is_Concurrent_Type (Prefix_Type) then
3967 -- Find visible operation with given name. For a protected type,
3968 -- the possible candidates are discriminants, entries or protected
3969 -- procedures. For a task type, the set can only include entries or
3970 -- discriminants if the task type is not an enclosing scope. If it
3971 -- is an enclosing scope (e.g. in an inner task) then all entities
3972 -- are visible, but the prefix must denote the enclosing scope, i.e.
3973 -- can only be a direct name or an expanded name.
3975 Set_Etype (Sel, Any_Type);
3976 In_Scope := In_Open_Scopes (Prefix_Type);
3978 while Present (Comp) loop
3979 if Chars (Comp) = Chars (Sel) then
3980 if Is_Overloadable (Comp) then
3981 Add_One_Interp (Sel, Comp, Etype (Comp));
3983 -- If the prefix is tagged, the correct interpretation may
3984 -- lie in the primitive or class-wide operations of the
3985 -- type. Perform a simple conformance check to determine
3986 -- whether Try_Object_Operation should be invoked even if
3987 -- a visible entity is found.
3989 if Is_Tagged_Type (Prefix_Type)
3991 Nkind_In (Parent (N), N_Procedure_Call_Statement,
3993 N_Indexed_Component)
3994 and then Has_Mode_Conformant_Spec (Comp)
3996 Has_Candidate := True;
3999 -- Note: a selected component may not denote a component of a
4000 -- protected type (4.1.3(7)).
4002 elsif Ekind_In (Comp, E_Discriminant, E_Entry_Family)
4004 and then not Is_Protected_Type (Prefix_Type)
4005 and then Is_Entity_Name (Name))
4007 Set_Entity_With_Style_Check (Sel, Comp);
4008 Generate_Reference (Comp, Sel);
4014 Set_Etype (Sel, Etype (Comp));
4015 Set_Etype (N, Etype (Comp));
4017 if Ekind (Comp) = E_Discriminant then
4018 Set_Original_Discriminant (Sel, Comp);
4021 -- For access type case, introduce explicit dereference for
4022 -- more uniform treatment of entry calls.
4024 if Is_Access_Type (Etype (Name)) then
4025 Insert_Explicit_Dereference (Name);
4027 (Warn_On_Dereference, "?implicit dereference", N);
4033 exit when not In_Scope
4035 Comp = First_Private_Entity (Base_Type (Prefix_Type));
4038 -- If there is no visible entity with the given name or none of the
4039 -- visible entities are plausible interpretations, check whether
4040 -- there is some other primitive operation with that name.
4042 if Ada_Version >= Ada_2005
4043 and then Is_Tagged_Type (Prefix_Type)
4045 if (Etype (N) = Any_Type
4046 or else not Has_Candidate)
4047 and then Try_Object_Operation (N)
4051 -- If the context is not syntactically a procedure call, it
4052 -- may be a call to a primitive function declared outside of
4053 -- the synchronized type.
4055 -- If the context is a procedure call, there might still be
4056 -- an overloading between an entry and a primitive procedure
4057 -- declared outside of the synchronized type, called in prefix
4058 -- notation. This is harder to disambiguate because in one case
4059 -- the controlling formal is implicit ???
4061 elsif Nkind (Parent (N)) /= N_Procedure_Call_Statement
4062 and then Nkind (Parent (N)) /= N_Indexed_Component
4063 and then Try_Object_Operation (N)
4069 if Etype (N) = Any_Type and then Is_Protected_Type (Prefix_Type) then
4070 -- Case of a prefix of a protected type: selector might denote
4071 -- an invisible private component.
4073 Comp := First_Private_Entity (Base_Type (Prefix_Type));
4074 while Present (Comp) and then Chars (Comp) /= Chars (Sel) loop
4078 if Present (Comp) then
4079 if Is_Single_Concurrent_Object then
4080 Error_Msg_Node_2 := Entity (Name);
4081 Error_Msg_NE ("invisible selector& for &", N, Sel);
4084 Error_Msg_Node_2 := First_Subtype (Prefix_Type);
4085 Error_Msg_NE ("invisible selector& for }", N, Sel);
4091 Set_Is_Overloaded (N, Is_Overloaded (Sel));
4096 Error_Msg_NE ("invalid prefix in selected component&", N, Sel);
4099 -- If N still has no type, the component is not defined in the prefix
4101 if Etype (N) = Any_Type then
4103 if Is_Single_Concurrent_Object then
4104 Error_Msg_Node_2 := Entity (Name);
4105 Error_Msg_NE ("no selector& for&", N, Sel);
4107 Check_Misspelled_Selector (Type_To_Use, Sel);
4109 elsif Is_Generic_Type (Prefix_Type)
4110 and then Ekind (Prefix_Type) = E_Record_Type_With_Private
4111 and then Prefix_Type /= Etype (Prefix_Type)
4112 and then Is_Record_Type (Etype (Prefix_Type))
4114 -- If this is a derived formal type, the parent may have
4115 -- different visibility at this point. Try for an inherited
4116 -- component before reporting an error.
4118 Set_Etype (Prefix (N), Etype (Prefix_Type));
4119 Analyze_Selected_Component (N);
4122 -- Similarly, if this is the actual for a formal derived type, the
4123 -- component inherited from the generic parent may not be visible
4124 -- in the actual, but the selected component is legal.
4126 elsif Ekind (Prefix_Type) = E_Record_Subtype_With_Private
4127 and then Is_Generic_Actual_Type (Prefix_Type)
4128 and then Present (Full_View (Prefix_Type))
4131 Find_Component_In_Instance
4132 (Generic_Parent_Type (Parent (Prefix_Type)));
4135 -- Finally, the formal and the actual may be private extensions,
4136 -- but the generic is declared in a child unit of the parent, and
4137 -- an additional step is needed to retrieve the proper scope.
4140 and then Present (Parent_Subtype (Etype (Base_Type (Prefix_Type))))
4142 Find_Component_In_Instance
4143 (Parent_Subtype (Etype (Base_Type (Prefix_Type))));
4146 -- Component not found, specialize error message when appropriate
4149 if Ekind (Prefix_Type) = E_Record_Subtype then
4151 -- Check whether this is a component of the base type which
4152 -- is absent from a statically constrained subtype. This will
4153 -- raise constraint error at run time, but is not a compile-
4154 -- time error. When the selector is illegal for base type as
4155 -- well fall through and generate a compilation error anyway.
4157 Comp := First_Component (Base_Type (Prefix_Type));
4158 while Present (Comp) loop
4159 if Chars (Comp) = Chars (Sel)
4160 and then Is_Visible_Component (Comp)
4162 Set_Entity_With_Style_Check (Sel, Comp);
4163 Generate_Reference (Comp, Sel);
4164 Set_Etype (Sel, Etype (Comp));
4165 Set_Etype (N, Etype (Comp));
4167 -- Emit appropriate message. Gigi will replace the
4168 -- node subsequently with the appropriate Raise.
4170 Apply_Compile_Time_Constraint_Error
4171 (N, "component not present in }?",
4172 CE_Discriminant_Check_Failed,
4173 Ent => Prefix_Type, Rep => False);
4174 Set_Raises_Constraint_Error (N);
4178 Next_Component (Comp);
4183 Error_Msg_Node_2 := First_Subtype (Prefix_Type);
4184 Error_Msg_NE ("no selector& for}", N, Sel);
4186 Check_Misspelled_Selector (Type_To_Use, Sel);
4189 Set_Entity (Sel, Any_Id);
4190 Set_Etype (Sel, Any_Type);
4192 end Analyze_Selected_Component;
4194 ---------------------------
4195 -- Analyze_Short_Circuit --
4196 ---------------------------
4198 procedure Analyze_Short_Circuit (N : Node_Id) is
4199 L : constant Node_Id := Left_Opnd (N);
4200 R : constant Node_Id := Right_Opnd (N);
4205 Analyze_Expression (L);
4206 Analyze_Expression (R);
4207 Set_Etype (N, Any_Type);
4209 if not Is_Overloaded (L) then
4210 if Root_Type (Etype (L)) = Standard_Boolean
4211 and then Has_Compatible_Type (R, Etype (L))
4213 Add_One_Interp (N, Etype (L), Etype (L));
4217 Get_First_Interp (L, Ind, It);
4218 while Present (It.Typ) loop
4219 if Root_Type (It.Typ) = Standard_Boolean
4220 and then Has_Compatible_Type (R, It.Typ)
4222 Add_One_Interp (N, It.Typ, It.Typ);
4225 Get_Next_Interp (Ind, It);
4229 -- Here we have failed to find an interpretation. Clearly we know that
4230 -- it is not the case that both operands can have an interpretation of
4231 -- Boolean, but this is by far the most likely intended interpretation.
4232 -- So we simply resolve both operands as Booleans, and at least one of
4233 -- these resolutions will generate an error message, and we do not need
4234 -- to give another error message on the short circuit operation itself.
4236 if Etype (N) = Any_Type then
4237 Resolve (L, Standard_Boolean);
4238 Resolve (R, Standard_Boolean);
4239 Set_Etype (N, Standard_Boolean);
4241 end Analyze_Short_Circuit;
4247 procedure Analyze_Slice (N : Node_Id) is
4248 P : constant Node_Id := Prefix (N);
4249 D : constant Node_Id := Discrete_Range (N);
4250 Array_Type : Entity_Id;
4252 procedure Analyze_Overloaded_Slice;
4253 -- If the prefix is overloaded, select those interpretations that
4254 -- yield a one-dimensional array type.
4256 ------------------------------
4257 -- Analyze_Overloaded_Slice --
4258 ------------------------------
4260 procedure Analyze_Overloaded_Slice is
4266 Set_Etype (N, Any_Type);
4268 Get_First_Interp (P, I, It);
4269 while Present (It.Nam) loop
4272 if Is_Access_Type (Typ) then
4273 Typ := Designated_Type (Typ);
4274 Error_Msg_NW (Warn_On_Dereference, "?implicit dereference", N);
4277 if Is_Array_Type (Typ)
4278 and then Number_Dimensions (Typ) = 1
4279 and then Has_Compatible_Type (D, Etype (First_Index (Typ)))
4281 Add_One_Interp (N, Typ, Typ);
4284 Get_Next_Interp (I, It);
4287 if Etype (N) = Any_Type then
4288 Error_Msg_N ("expect array type in prefix of slice", N);
4290 end Analyze_Overloaded_Slice;
4292 -- Start of processing for Analyze_Slice
4295 -- Slice is not allowed in SPARK or ALFA
4297 if Formal_Verification_Mode then
4298 Error_Msg_F ("|~~slice is not allowed", N);
4301 -- Proceed with analysis
4306 if Is_Overloaded (P) then
4307 Analyze_Overloaded_Slice;
4310 Array_Type := Etype (P);
4311 Set_Etype (N, Any_Type);
4313 if Is_Access_Type (Array_Type) then
4314 Array_Type := Designated_Type (Array_Type);
4315 Error_Msg_NW (Warn_On_Dereference, "?implicit dereference", N);
4318 if not Is_Array_Type (Array_Type) then
4319 Wrong_Type (P, Any_Array);
4321 elsif Number_Dimensions (Array_Type) > 1 then
4323 ("type is not one-dimensional array in slice prefix", N);
4326 Has_Compatible_Type (D, Etype (First_Index (Array_Type)))
4328 Wrong_Type (D, Etype (First_Index (Array_Type)));
4331 Set_Etype (N, Array_Type);
4336 -----------------------------
4337 -- Analyze_Type_Conversion --
4338 -----------------------------
4340 procedure Analyze_Type_Conversion (N : Node_Id) is
4341 Expr : constant Node_Id := Expression (N);
4345 -- If Conversion_OK is set, then the Etype is already set, and the
4346 -- only processing required is to analyze the expression. This is
4347 -- used to construct certain "illegal" conversions which are not
4348 -- allowed by Ada semantics, but can be handled OK by Gigi, see
4349 -- Sinfo for further details.
4351 if Conversion_OK (N) then
4356 -- Otherwise full type analysis is required, as well as some semantic
4357 -- checks to make sure the argument of the conversion is appropriate.
4359 Find_Type (Subtype_Mark (N));
4360 T := Entity (Subtype_Mark (N));
4362 Check_Fully_Declared (T, N);
4363 Analyze_Expression (Expr);
4364 Validate_Remote_Type_Type_Conversion (N);
4366 -- Only remaining step is validity checks on the argument. These
4367 -- are skipped if the conversion does not come from the source.
4369 if not Comes_From_Source (N) then
4372 -- If there was an error in a generic unit, no need to replicate the
4373 -- error message. Conversely, constant-folding in the generic may
4374 -- transform the argument of a conversion into a string literal, which
4375 -- is legal. Therefore the following tests are not performed in an
4378 elsif In_Instance then
4381 elsif Nkind (Expr) = N_Null then
4382 Error_Msg_N ("argument of conversion cannot be null", N);
4383 Error_Msg_N ("\use qualified expression instead", N);
4384 Set_Etype (N, Any_Type);
4386 elsif Nkind (Expr) = N_Aggregate then
4387 Error_Msg_N ("argument of conversion cannot be aggregate", N);
4388 Error_Msg_N ("\use qualified expression instead", N);
4390 elsif Nkind (Expr) = N_Allocator then
4391 Error_Msg_N ("argument of conversion cannot be an allocator", N);
4392 Error_Msg_N ("\use qualified expression instead", N);
4394 elsif Nkind (Expr) = N_String_Literal then
4395 Error_Msg_N ("argument of conversion cannot be string literal", N);
4396 Error_Msg_N ("\use qualified expression instead", N);
4398 elsif Nkind (Expr) = N_Character_Literal then
4399 if Ada_Version = Ada_83 then
4402 Error_Msg_N ("argument of conversion cannot be character literal",
4404 Error_Msg_N ("\use qualified expression instead", N);
4407 elsif Nkind (Expr) = N_Attribute_Reference
4409 (Attribute_Name (Expr) = Name_Access or else
4410 Attribute_Name (Expr) = Name_Unchecked_Access or else
4411 Attribute_Name (Expr) = Name_Unrestricted_Access)
4413 Error_Msg_N ("argument of conversion cannot be access", N);
4414 Error_Msg_N ("\use qualified expression instead", N);
4416 end Analyze_Type_Conversion;
4418 ----------------------
4419 -- Analyze_Unary_Op --
4420 ----------------------
4422 procedure Analyze_Unary_Op (N : Node_Id) is
4423 R : constant Node_Id := Right_Opnd (N);
4424 Op_Id : Entity_Id := Entity (N);
4427 Set_Etype (N, Any_Type);
4428 Candidate_Type := Empty;
4430 Analyze_Expression (R);
4432 if Present (Op_Id) then
4433 if Ekind (Op_Id) = E_Operator then
4434 Find_Unary_Types (R, Op_Id, N);
4436 Add_One_Interp (N, Op_Id, Etype (Op_Id));
4440 Op_Id := Get_Name_Entity_Id (Chars (N));
4441 while Present (Op_Id) loop
4442 if Ekind (Op_Id) = E_Operator then
4443 if No (Next_Entity (First_Entity (Op_Id))) then
4444 Find_Unary_Types (R, Op_Id, N);
4447 elsif Is_Overloadable (Op_Id) then
4448 Analyze_User_Defined_Unary_Op (N, Op_Id);
4451 Op_Id := Homonym (Op_Id);
4456 end Analyze_Unary_Op;
4458 ----------------------------------
4459 -- Analyze_Unchecked_Expression --
4460 ----------------------------------
4462 procedure Analyze_Unchecked_Expression (N : Node_Id) is
4464 Analyze (Expression (N), Suppress => All_Checks);
4465 Set_Etype (N, Etype (Expression (N)));
4466 Save_Interps (Expression (N), N);
4467 end Analyze_Unchecked_Expression;
4469 ---------------------------------------
4470 -- Analyze_Unchecked_Type_Conversion --
4471 ---------------------------------------
4473 procedure Analyze_Unchecked_Type_Conversion (N : Node_Id) is
4475 Find_Type (Subtype_Mark (N));
4476 Analyze_Expression (Expression (N));
4477 Set_Etype (N, Entity (Subtype_Mark (N)));
4478 end Analyze_Unchecked_Type_Conversion;
4480 ------------------------------------
4481 -- Analyze_User_Defined_Binary_Op --
4482 ------------------------------------
4484 procedure Analyze_User_Defined_Binary_Op
4489 -- Only do analysis if the operator Comes_From_Source, since otherwise
4490 -- the operator was generated by the expander, and all such operators
4491 -- always refer to the operators in package Standard.
4493 if Comes_From_Source (N) then
4495 F1 : constant Entity_Id := First_Formal (Op_Id);
4496 F2 : constant Entity_Id := Next_Formal (F1);
4499 -- Verify that Op_Id is a visible binary function. Note that since
4500 -- we know Op_Id is overloaded, potentially use visible means use
4501 -- visible for sure (RM 9.4(11)).
4503 if Ekind (Op_Id) = E_Function
4504 and then Present (F2)
4505 and then (Is_Immediately_Visible (Op_Id)
4506 or else Is_Potentially_Use_Visible (Op_Id))
4507 and then Has_Compatible_Type (Left_Opnd (N), Etype (F1))
4508 and then Has_Compatible_Type (Right_Opnd (N), Etype (F2))
4510 Add_One_Interp (N, Op_Id, Etype (Op_Id));
4512 -- If the left operand is overloaded, indicate that the
4513 -- current type is a viable candidate. This is redundant
4514 -- in most cases, but for equality and comparison operators
4515 -- where the context does not impose a type on the operands,
4516 -- setting the proper type is necessary to avoid subsequent
4517 -- ambiguities during resolution, when both user-defined and
4518 -- predefined operators may be candidates.
4520 if Is_Overloaded (Left_Opnd (N)) then
4521 Set_Etype (Left_Opnd (N), Etype (F1));
4524 if Debug_Flag_E then
4525 Write_Str ("user defined operator ");
4526 Write_Name (Chars (Op_Id));
4527 Write_Str (" on node ");
4528 Write_Int (Int (N));
4534 end Analyze_User_Defined_Binary_Op;
4536 -----------------------------------
4537 -- Analyze_User_Defined_Unary_Op --
4538 -----------------------------------
4540 procedure Analyze_User_Defined_Unary_Op
4545 -- Only do analysis if the operator Comes_From_Source, since otherwise
4546 -- the operator was generated by the expander, and all such operators
4547 -- always refer to the operators in package Standard.
4549 if Comes_From_Source (N) then
4551 F : constant Entity_Id := First_Formal (Op_Id);
4554 -- Verify that Op_Id is a visible unary function. Note that since
4555 -- we know Op_Id is overloaded, potentially use visible means use
4556 -- visible for sure (RM 9.4(11)).
4558 if Ekind (Op_Id) = E_Function
4559 and then No (Next_Formal (F))
4560 and then (Is_Immediately_Visible (Op_Id)
4561 or else Is_Potentially_Use_Visible (Op_Id))
4562 and then Has_Compatible_Type (Right_Opnd (N), Etype (F))
4564 Add_One_Interp (N, Op_Id, Etype (Op_Id));
4568 end Analyze_User_Defined_Unary_Op;
4570 ---------------------------
4571 -- Check_Arithmetic_Pair --
4572 ---------------------------
4574 procedure Check_Arithmetic_Pair
4575 (T1, T2 : Entity_Id;
4579 Op_Name : constant Name_Id := Chars (Op_Id);
4581 function Has_Fixed_Op (Typ : Entity_Id; Op : Entity_Id) return Boolean;
4582 -- Check whether the fixed-point type Typ has a user-defined operator
4583 -- (multiplication or division) that should hide the corresponding
4584 -- predefined operator. Used to implement Ada 2005 AI-264, to make
4585 -- such operators more visible and therefore useful.
4587 -- If the name of the operation is an expanded name with prefix
4588 -- Standard, the predefined universal fixed operator is available,
4589 -- as specified by AI-420 (RM 4.5.5 (19.1/2)).
4591 function Specific_Type (T1, T2 : Entity_Id) return Entity_Id;
4592 -- Get specific type (i.e. non-universal type if there is one)
4598 function Has_Fixed_Op (Typ : Entity_Id; Op : Entity_Id) return Boolean is
4599 Bas : constant Entity_Id := Base_Type (Typ);
4605 -- If the universal_fixed operation is given explicitly the rule
4606 -- concerning primitive operations of the type do not apply.
4608 if Nkind (N) = N_Function_Call
4609 and then Nkind (Name (N)) = N_Expanded_Name
4610 and then Entity (Prefix (Name (N))) = Standard_Standard
4615 -- The operation is treated as primitive if it is declared in the
4616 -- same scope as the type, and therefore on the same entity chain.
4618 Ent := Next_Entity (Typ);
4619 while Present (Ent) loop
4620 if Chars (Ent) = Chars (Op) then
4621 F1 := First_Formal (Ent);
4622 F2 := Next_Formal (F1);
4624 -- The operation counts as primitive if either operand or
4625 -- result are of the given base type, and both operands are
4626 -- fixed point types.
4628 if (Base_Type (Etype (F1)) = Bas
4629 and then Is_Fixed_Point_Type (Etype (F2)))
4632 (Base_Type (Etype (F2)) = Bas
4633 and then Is_Fixed_Point_Type (Etype (F1)))
4636 (Base_Type (Etype (Ent)) = Bas
4637 and then Is_Fixed_Point_Type (Etype (F1))
4638 and then Is_Fixed_Point_Type (Etype (F2)))
4654 function Specific_Type (T1, T2 : Entity_Id) return Entity_Id is
4656 if T1 = Universal_Integer or else T1 = Universal_Real then
4657 return Base_Type (T2);
4659 return Base_Type (T1);
4663 -- Start of processing for Check_Arithmetic_Pair
4666 if Op_Name = Name_Op_Add or else Op_Name = Name_Op_Subtract then
4668 if Is_Numeric_Type (T1)
4669 and then Is_Numeric_Type (T2)
4670 and then (Covers (T1 => T1, T2 => T2)
4672 Covers (T1 => T2, T2 => T1))
4674 Add_One_Interp (N, Op_Id, Specific_Type (T1, T2));
4677 elsif Op_Name = Name_Op_Multiply or else Op_Name = Name_Op_Divide then
4679 if Is_Fixed_Point_Type (T1)
4680 and then (Is_Fixed_Point_Type (T2)
4681 or else T2 = Universal_Real)
4683 -- If Treat_Fixed_As_Integer is set then the Etype is already set
4684 -- and no further processing is required (this is the case of an
4685 -- operator constructed by Exp_Fixd for a fixed point operation)
4686 -- Otherwise add one interpretation with universal fixed result
4687 -- If the operator is given in functional notation, it comes
4688 -- from source and Fixed_As_Integer cannot apply.
4690 if (Nkind (N) not in N_Op
4691 or else not Treat_Fixed_As_Integer (N))
4693 (not Has_Fixed_Op (T1, Op_Id)
4694 or else Nkind (Parent (N)) = N_Type_Conversion)
4696 Add_One_Interp (N, Op_Id, Universal_Fixed);
4699 elsif Is_Fixed_Point_Type (T2)
4700 and then (Nkind (N) not in N_Op
4701 or else not Treat_Fixed_As_Integer (N))
4702 and then T1 = Universal_Real
4704 (not Has_Fixed_Op (T1, Op_Id)
4705 or else Nkind (Parent (N)) = N_Type_Conversion)
4707 Add_One_Interp (N, Op_Id, Universal_Fixed);
4709 elsif Is_Numeric_Type (T1)
4710 and then Is_Numeric_Type (T2)
4711 and then (Covers (T1 => T1, T2 => T2)
4713 Covers (T1 => T2, T2 => T1))
4715 Add_One_Interp (N, Op_Id, Specific_Type (T1, T2));
4717 elsif Is_Fixed_Point_Type (T1)
4718 and then (Base_Type (T2) = Base_Type (Standard_Integer)
4719 or else T2 = Universal_Integer)
4721 Add_One_Interp (N, Op_Id, T1);
4723 elsif T2 = Universal_Real
4724 and then Base_Type (T1) = Base_Type (Standard_Integer)
4725 and then Op_Name = Name_Op_Multiply
4727 Add_One_Interp (N, Op_Id, Any_Fixed);
4729 elsif T1 = Universal_Real
4730 and then Base_Type (T2) = Base_Type (Standard_Integer)
4732 Add_One_Interp (N, Op_Id, Any_Fixed);
4734 elsif Is_Fixed_Point_Type (T2)
4735 and then (Base_Type (T1) = Base_Type (Standard_Integer)
4736 or else T1 = Universal_Integer)
4737 and then Op_Name = Name_Op_Multiply
4739 Add_One_Interp (N, Op_Id, T2);
4741 elsif T1 = Universal_Real and then T2 = Universal_Integer then
4742 Add_One_Interp (N, Op_Id, T1);
4744 elsif T2 = Universal_Real
4745 and then T1 = Universal_Integer
4746 and then Op_Name = Name_Op_Multiply
4748 Add_One_Interp (N, Op_Id, T2);
4751 elsif Op_Name = Name_Op_Mod or else Op_Name = Name_Op_Rem then
4753 -- Note: The fixed-point operands case with Treat_Fixed_As_Integer
4754 -- set does not require any special processing, since the Etype is
4755 -- already set (case of operation constructed by Exp_Fixed).
4757 if Is_Integer_Type (T1)
4758 and then (Covers (T1 => T1, T2 => T2)
4760 Covers (T1 => T2, T2 => T1))
4762 Add_One_Interp (N, Op_Id, Specific_Type (T1, T2));
4765 elsif Op_Name = Name_Op_Expon then
4766 if Is_Numeric_Type (T1)
4767 and then not Is_Fixed_Point_Type (T1)
4768 and then (Base_Type (T2) = Base_Type (Standard_Integer)
4769 or else T2 = Universal_Integer)
4771 Add_One_Interp (N, Op_Id, Base_Type (T1));
4774 else pragma Assert (Nkind (N) in N_Op_Shift);
4776 -- If not one of the predefined operators, the node may be one
4777 -- of the intrinsic functions. Its kind is always specific, and
4778 -- we can use it directly, rather than the name of the operation.
4780 if Is_Integer_Type (T1)
4781 and then (Base_Type (T2) = Base_Type (Standard_Integer)
4782 or else T2 = Universal_Integer)
4784 Add_One_Interp (N, Op_Id, Base_Type (T1));
4787 end Check_Arithmetic_Pair;
4789 -------------------------------
4790 -- Check_Misspelled_Selector --
4791 -------------------------------
4793 procedure Check_Misspelled_Selector
4794 (Prefix : Entity_Id;
4797 Max_Suggestions : constant := 2;
4798 Nr_Of_Suggestions : Natural := 0;
4800 Suggestion_1 : Entity_Id := Empty;
4801 Suggestion_2 : Entity_Id := Empty;
4806 -- All the components of the prefix of selector Sel are matched
4807 -- against Sel and a count is maintained of possible misspellings.
4808 -- When at the end of the analysis there are one or two (not more!)
4809 -- possible misspellings, these misspellings will be suggested as
4810 -- possible correction.
4812 if not (Is_Private_Type (Prefix) or else Is_Record_Type (Prefix)) then
4814 -- Concurrent types should be handled as well ???
4819 Comp := First_Entity (Prefix);
4820 while Nr_Of_Suggestions <= Max_Suggestions and then Present (Comp) loop
4821 if Is_Visible_Component (Comp) then
4822 if Is_Bad_Spelling_Of (Chars (Comp), Chars (Sel)) then
4823 Nr_Of_Suggestions := Nr_Of_Suggestions + 1;
4825 case Nr_Of_Suggestions is
4826 when 1 => Suggestion_1 := Comp;
4827 when 2 => Suggestion_2 := Comp;
4828 when others => exit;
4833 Comp := Next_Entity (Comp);
4836 -- Report at most two suggestions
4838 if Nr_Of_Suggestions = 1 then
4839 Error_Msg_NE -- CODEFIX
4840 ("\possible misspelling of&", Sel, Suggestion_1);
4842 elsif Nr_Of_Suggestions = 2 then
4843 Error_Msg_Node_2 := Suggestion_2;
4844 Error_Msg_NE -- CODEFIX
4845 ("\possible misspelling of& or&", Sel, Suggestion_1);
4847 end Check_Misspelled_Selector;
4849 ----------------------
4850 -- Defined_In_Scope --
4851 ----------------------
4853 function Defined_In_Scope (T : Entity_Id; S : Entity_Id) return Boolean
4855 S1 : constant Entity_Id := Scope (Base_Type (T));
4858 or else (S1 = System_Aux_Id and then S = Scope (S1));
4859 end Defined_In_Scope;
4865 procedure Diagnose_Call (N : Node_Id; Nam : Node_Id) is
4871 Void_Interp_Seen : Boolean := False;
4874 pragma Warnings (Off, Boolean);
4877 if Ada_Version >= Ada_2005 then
4878 Actual := First_Actual (N);
4879 while Present (Actual) loop
4881 -- Ada 2005 (AI-50217): Post an error in case of premature
4882 -- usage of an entity from the limited view.
4884 if not Analyzed (Etype (Actual))
4885 and then From_With_Type (Etype (Actual))
4887 Error_Msg_Qual_Level := 1;
4889 ("missing with_clause for scope of imported type&",
4890 Actual, Etype (Actual));
4891 Error_Msg_Qual_Level := 0;
4894 Next_Actual (Actual);
4898 -- Analyze each candidate call again, with full error reporting
4902 ("no candidate interpretations match the actuals:!", Nam);
4903 Err_Mode := All_Errors_Mode;
4904 All_Errors_Mode := True;
4906 -- If this is a call to an operation of a concurrent type,
4907 -- the failed interpretations have been removed from the
4908 -- name. Recover them to provide full diagnostics.
4910 if Nkind (Parent (Nam)) = N_Selected_Component then
4911 Set_Entity (Nam, Empty);
4912 New_Nam := New_Copy_Tree (Parent (Nam));
4913 Set_Is_Overloaded (New_Nam, False);
4914 Set_Is_Overloaded (Selector_Name (New_Nam), False);
4915 Set_Parent (New_Nam, Parent (Parent (Nam)));
4916 Analyze_Selected_Component (New_Nam);
4917 Get_First_Interp (Selector_Name (New_Nam), X, It);
4919 Get_First_Interp (Nam, X, It);
4922 while Present (It.Nam) loop
4923 if Etype (It.Nam) = Standard_Void_Type then
4924 Void_Interp_Seen := True;
4927 Analyze_One_Call (N, It.Nam, True, Success);
4928 Get_Next_Interp (X, It);
4931 if Nkind (N) = N_Function_Call then
4932 Get_First_Interp (Nam, X, It);
4933 while Present (It.Nam) loop
4934 if Ekind_In (It.Nam, E_Function, E_Operator) then
4937 Get_Next_Interp (X, It);
4941 -- If all interpretations are procedures, this deserves a
4942 -- more precise message. Ditto if this appears as the prefix
4943 -- of a selected component, which may be a lexical error.
4946 ("\context requires function call, found procedure name", Nam);
4948 if Nkind (Parent (N)) = N_Selected_Component
4949 and then N = Prefix (Parent (N))
4951 Error_Msg_N -- CODEFIX
4952 ("\period should probably be semicolon", Parent (N));
4955 elsif Nkind (N) = N_Procedure_Call_Statement
4956 and then not Void_Interp_Seen
4959 "\function name found in procedure call", Nam);
4962 All_Errors_Mode := Err_Mode;
4965 ---------------------------
4966 -- Find_Arithmetic_Types --
4967 ---------------------------
4969 procedure Find_Arithmetic_Types
4974 Index1 : Interp_Index;
4975 Index2 : Interp_Index;
4979 procedure Check_Right_Argument (T : Entity_Id);
4980 -- Check right operand of operator
4982 --------------------------
4983 -- Check_Right_Argument --
4984 --------------------------
4986 procedure Check_Right_Argument (T : Entity_Id) is
4988 if not Is_Overloaded (R) then
4989 Check_Arithmetic_Pair (T, Etype (R), Op_Id, N);
4991 Get_First_Interp (R, Index2, It2);
4992 while Present (It2.Typ) loop
4993 Check_Arithmetic_Pair (T, It2.Typ, Op_Id, N);
4994 Get_Next_Interp (Index2, It2);
4997 end Check_Right_Argument;
4999 -- Start of processing for Find_Arithmetic_Types
5002 if not Is_Overloaded (L) then
5003 Check_Right_Argument (Etype (L));
5006 Get_First_Interp (L, Index1, It1);
5007 while Present (It1.Typ) loop
5008 Check_Right_Argument (It1.Typ);
5009 Get_Next_Interp (Index1, It1);
5013 end Find_Arithmetic_Types;
5015 ------------------------
5016 -- Find_Boolean_Types --
5017 ------------------------
5019 procedure Find_Boolean_Types
5024 Index : Interp_Index;
5027 procedure Check_Numeric_Argument (T : Entity_Id);
5028 -- Special case for logical operations one of whose operands is an
5029 -- integer literal. If both are literal the result is any modular type.
5031 ----------------------------
5032 -- Check_Numeric_Argument --
5033 ----------------------------
5035 procedure Check_Numeric_Argument (T : Entity_Id) is
5037 if T = Universal_Integer then
5038 Add_One_Interp (N, Op_Id, Any_Modular);
5040 elsif Is_Modular_Integer_Type (T) then
5041 Add_One_Interp (N, Op_Id, T);
5043 end Check_Numeric_Argument;
5045 -- Start of processing for Find_Boolean_Types
5048 if not Is_Overloaded (L) then
5049 if Etype (L) = Universal_Integer
5050 or else Etype (L) = Any_Modular
5052 if not Is_Overloaded (R) then
5053 Check_Numeric_Argument (Etype (R));
5056 Get_First_Interp (R, Index, It);
5057 while Present (It.Typ) loop
5058 Check_Numeric_Argument (It.Typ);
5059 Get_Next_Interp (Index, It);
5063 -- If operands are aggregates, we must assume that they may be
5064 -- boolean arrays, and leave disambiguation for the second pass.
5065 -- If only one is an aggregate, verify that the other one has an
5066 -- interpretation as a boolean array
5068 elsif Nkind (L) = N_Aggregate then
5069 if Nkind (R) = N_Aggregate then
5070 Add_One_Interp (N, Op_Id, Etype (L));
5072 elsif not Is_Overloaded (R) then
5073 if Valid_Boolean_Arg (Etype (R)) then
5074 Add_One_Interp (N, Op_Id, Etype (R));
5078 Get_First_Interp (R, Index, It);
5079 while Present (It.Typ) loop
5080 if Valid_Boolean_Arg (It.Typ) then
5081 Add_One_Interp (N, Op_Id, It.Typ);
5084 Get_Next_Interp (Index, It);
5088 elsif Valid_Boolean_Arg (Etype (L))
5089 and then Has_Compatible_Type (R, Etype (L))
5091 Add_One_Interp (N, Op_Id, Etype (L));
5095 Get_First_Interp (L, Index, It);
5096 while Present (It.Typ) loop
5097 if Valid_Boolean_Arg (It.Typ)
5098 and then Has_Compatible_Type (R, It.Typ)
5100 Add_One_Interp (N, Op_Id, It.Typ);
5103 Get_Next_Interp (Index, It);
5106 end Find_Boolean_Types;
5108 ---------------------------
5109 -- Find_Comparison_Types --
5110 ---------------------------
5112 procedure Find_Comparison_Types
5117 Index : Interp_Index;
5119 Found : Boolean := False;
5122 Scop : Entity_Id := Empty;
5124 procedure Try_One_Interp (T1 : Entity_Id);
5125 -- Routine to try one proposed interpretation. Note that the context
5126 -- of the operator plays no role in resolving the arguments, so that
5127 -- if there is more than one interpretation of the operands that is
5128 -- compatible with comparison, the operation is ambiguous.
5130 --------------------
5131 -- Try_One_Interp --
5132 --------------------
5134 procedure Try_One_Interp (T1 : Entity_Id) is
5137 -- If the operator is an expanded name, then the type of the operand
5138 -- must be defined in the corresponding scope. If the type is
5139 -- universal, the context will impose the correct type.
5142 and then not Defined_In_Scope (T1, Scop)
5143 and then T1 /= Universal_Integer
5144 and then T1 /= Universal_Real
5145 and then T1 /= Any_String
5146 and then T1 /= Any_Composite
5151 if Valid_Comparison_Arg (T1)
5152 and then Has_Compatible_Type (R, T1)
5155 and then Base_Type (T1) /= Base_Type (T_F)
5157 It := Disambiguate (L, I_F, Index, Any_Type);
5159 if It = No_Interp then
5160 Ambiguous_Operands (N);
5161 Set_Etype (L, Any_Type);
5175 Find_Non_Universal_Interpretations (N, R, Op_Id, T1);
5180 -- Start of processing for Find_Comparison_Types
5183 -- If left operand is aggregate, the right operand has to
5184 -- provide a usable type for it.
5186 if Nkind (L) = N_Aggregate
5187 and then Nkind (R) /= N_Aggregate
5189 Find_Comparison_Types (L => R, R => L, Op_Id => Op_Id, N => N);
5193 if Nkind (N) = N_Function_Call
5194 and then Nkind (Name (N)) = N_Expanded_Name
5196 Scop := Entity (Prefix (Name (N)));
5198 -- The prefix may be a package renaming, and the subsequent test
5199 -- requires the original package.
5201 if Ekind (Scop) = E_Package
5202 and then Present (Renamed_Entity (Scop))
5204 Scop := Renamed_Entity (Scop);
5205 Set_Entity (Prefix (Name (N)), Scop);
5209 if not Is_Overloaded (L) then
5210 Try_One_Interp (Etype (L));
5213 Get_First_Interp (L, Index, It);
5214 while Present (It.Typ) loop
5215 Try_One_Interp (It.Typ);
5216 Get_Next_Interp (Index, It);
5219 end Find_Comparison_Types;
5221 ----------------------------------------
5222 -- Find_Non_Universal_Interpretations --
5223 ----------------------------------------
5225 procedure Find_Non_Universal_Interpretations
5231 Index : Interp_Index;
5235 if T1 = Universal_Integer
5236 or else T1 = Universal_Real
5238 if not Is_Overloaded (R) then
5240 (N, Op_Id, Standard_Boolean, Base_Type (Etype (R)));
5242 Get_First_Interp (R, Index, It);
5243 while Present (It.Typ) loop
5244 if Covers (It.Typ, T1) then
5246 (N, Op_Id, Standard_Boolean, Base_Type (It.Typ));
5249 Get_Next_Interp (Index, It);
5253 Add_One_Interp (N, Op_Id, Standard_Boolean, Base_Type (T1));
5255 end Find_Non_Universal_Interpretations;
5257 ------------------------------
5258 -- Find_Concatenation_Types --
5259 ------------------------------
5261 procedure Find_Concatenation_Types
5266 Op_Type : constant Entity_Id := Etype (Op_Id);
5269 if Is_Array_Type (Op_Type)
5270 and then not Is_Limited_Type (Op_Type)
5272 and then (Has_Compatible_Type (L, Op_Type)
5274 Has_Compatible_Type (L, Component_Type (Op_Type)))
5276 and then (Has_Compatible_Type (R, Op_Type)
5278 Has_Compatible_Type (R, Component_Type (Op_Type)))
5280 Add_One_Interp (N, Op_Id, Op_Type);
5282 end Find_Concatenation_Types;
5284 -------------------------
5285 -- Find_Equality_Types --
5286 -------------------------
5288 procedure Find_Equality_Types
5293 Index : Interp_Index;
5295 Found : Boolean := False;
5298 Scop : Entity_Id := Empty;
5300 procedure Try_One_Interp (T1 : Entity_Id);
5301 -- The context of the equality operator plays no role in resolving the
5302 -- arguments, so that if there is more than one interpretation of the
5303 -- operands that is compatible with equality, the construct is ambiguous
5304 -- and an error can be emitted now, after trying to disambiguate, i.e.
5305 -- applying preference rules.
5307 --------------------
5308 -- Try_One_Interp --
5309 --------------------
5311 procedure Try_One_Interp (T1 : Entity_Id) is
5312 Bas : constant Entity_Id := Base_Type (T1);
5315 -- If the operator is an expanded name, then the type of the operand
5316 -- must be defined in the corresponding scope. If the type is
5317 -- universal, the context will impose the correct type. An anonymous
5318 -- type for a 'Access reference is also universal in this sense, as
5319 -- the actual type is obtained from context.
5320 -- In Ada 2005, the equality operator for anonymous access types
5321 -- is declared in Standard, and preference rules apply to it.
5323 if Present (Scop) then
5324 if Defined_In_Scope (T1, Scop)
5325 or else T1 = Universal_Integer
5326 or else T1 = Universal_Real
5327 or else T1 = Any_Access
5328 or else T1 = Any_String
5329 or else T1 = Any_Composite
5330 or else (Ekind (T1) = E_Access_Subprogram_Type
5331 and then not Comes_From_Source (T1))
5335 elsif Ekind (T1) = E_Anonymous_Access_Type
5336 and then Scop = Standard_Standard
5341 -- The scope does not contain an operator for the type
5346 -- If we have infix notation, the operator must be usable.
5347 -- Within an instance, if the type is already established we
5348 -- know it is correct.
5349 -- In Ada 2005, the equality on anonymous access types is declared
5350 -- in Standard, and is always visible.
5352 elsif In_Open_Scopes (Scope (Bas))
5353 or else Is_Potentially_Use_Visible (Bas)
5354 or else In_Use (Bas)
5355 or else (In_Use (Scope (Bas))
5356 and then not Is_Hidden (Bas))
5357 or else (In_Instance
5358 and then First_Subtype (T1) = First_Subtype (Etype (R)))
5359 or else Ekind (T1) = E_Anonymous_Access_Type
5364 -- Save candidate type for subsequent error message, if any
5366 if not Is_Limited_Type (T1) then
5367 Candidate_Type := T1;
5373 -- Ada 2005 (AI-230): Keep restriction imposed by Ada 83 and 95:
5374 -- Do not allow anonymous access types in equality operators.
5376 if Ada_Version < Ada_2005
5377 and then Ekind (T1) = E_Anonymous_Access_Type
5382 if T1 /= Standard_Void_Type
5383 and then not Is_Limited_Type (T1)
5384 and then not Is_Limited_Composite (T1)
5385 and then Has_Compatible_Type (R, T1)
5388 and then Base_Type (T1) /= Base_Type (T_F)
5390 It := Disambiguate (L, I_F, Index, Any_Type);
5392 if It = No_Interp then
5393 Ambiguous_Operands (N);
5394 Set_Etype (L, Any_Type);
5407 if not Analyzed (L) then
5411 Find_Non_Universal_Interpretations (N, R, Op_Id, T1);
5413 -- Case of operator was not visible, Etype still set to Any_Type
5415 if Etype (N) = Any_Type then
5419 elsif Scop = Standard_Standard
5420 and then Ekind (T1) = E_Anonymous_Access_Type
5426 -- Start of processing for Find_Equality_Types
5429 -- If left operand is aggregate, the right operand has to
5430 -- provide a usable type for it.
5432 if Nkind (L) = N_Aggregate
5433 and then Nkind (R) /= N_Aggregate
5435 Find_Equality_Types (L => R, R => L, Op_Id => Op_Id, N => N);
5439 if Nkind (N) = N_Function_Call
5440 and then Nkind (Name (N)) = N_Expanded_Name
5442 Scop := Entity (Prefix (Name (N)));
5444 -- The prefix may be a package renaming, and the subsequent test
5445 -- requires the original package.
5447 if Ekind (Scop) = E_Package
5448 and then Present (Renamed_Entity (Scop))
5450 Scop := Renamed_Entity (Scop);
5451 Set_Entity (Prefix (Name (N)), Scop);
5455 if not Is_Overloaded (L) then
5456 Try_One_Interp (Etype (L));
5459 Get_First_Interp (L, Index, It);
5460 while Present (It.Typ) loop
5461 Try_One_Interp (It.Typ);
5462 Get_Next_Interp (Index, It);
5465 end Find_Equality_Types;
5467 -------------------------
5468 -- Find_Negation_Types --
5469 -------------------------
5471 procedure Find_Negation_Types
5476 Index : Interp_Index;
5480 if not Is_Overloaded (R) then
5481 if Etype (R) = Universal_Integer then
5482 Add_One_Interp (N, Op_Id, Any_Modular);
5483 elsif Valid_Boolean_Arg (Etype (R)) then
5484 Add_One_Interp (N, Op_Id, Etype (R));
5488 Get_First_Interp (R, Index, It);
5489 while Present (It.Typ) loop
5490 if Valid_Boolean_Arg (It.Typ) then
5491 Add_One_Interp (N, Op_Id, It.Typ);
5494 Get_Next_Interp (Index, It);
5497 end Find_Negation_Types;
5499 ------------------------------
5500 -- Find_Primitive_Operation --
5501 ------------------------------
5503 function Find_Primitive_Operation (N : Node_Id) return Boolean is
5504 Obj : constant Node_Id := Prefix (N);
5505 Op : constant Node_Id := Selector_Name (N);
5512 Set_Etype (Op, Any_Type);
5514 if Is_Access_Type (Etype (Obj)) then
5515 Typ := Designated_Type (Etype (Obj));
5520 if Is_Class_Wide_Type (Typ) then
5521 Typ := Root_Type (Typ);
5524 Prims := Primitive_Operations (Typ);
5526 Prim := First_Elmt (Prims);
5527 while Present (Prim) loop
5528 if Chars (Node (Prim)) = Chars (Op) then
5529 Add_One_Interp (Op, Node (Prim), Etype (Node (Prim)));
5530 Set_Etype (N, Etype (Node (Prim)));
5536 -- Now look for class-wide operations of the type or any of its
5537 -- ancestors by iterating over the homonyms of the selector.
5540 Cls_Type : constant Entity_Id := Class_Wide_Type (Typ);
5544 Hom := Current_Entity (Op);
5545 while Present (Hom) loop
5546 if (Ekind (Hom) = E_Procedure
5548 Ekind (Hom) = E_Function)
5549 and then Scope (Hom) = Scope (Typ)
5550 and then Present (First_Formal (Hom))
5552 (Base_Type (Etype (First_Formal (Hom))) = Cls_Type
5554 (Is_Access_Type (Etype (First_Formal (Hom)))
5556 Ekind (Etype (First_Formal (Hom))) =
5557 E_Anonymous_Access_Type
5560 (Designated_Type (Etype (First_Formal (Hom)))) =
5563 Add_One_Interp (Op, Hom, Etype (Hom));
5564 Set_Etype (N, Etype (Hom));
5567 Hom := Homonym (Hom);
5571 return Etype (Op) /= Any_Type;
5572 end Find_Primitive_Operation;
5574 ----------------------
5575 -- Find_Unary_Types --
5576 ----------------------
5578 procedure Find_Unary_Types
5583 Index : Interp_Index;
5587 if not Is_Overloaded (R) then
5588 if Is_Numeric_Type (Etype (R)) then
5589 Add_One_Interp (N, Op_Id, Base_Type (Etype (R)));
5593 Get_First_Interp (R, Index, It);
5594 while Present (It.Typ) loop
5595 if Is_Numeric_Type (It.Typ) then
5596 Add_One_Interp (N, Op_Id, Base_Type (It.Typ));
5599 Get_Next_Interp (Index, It);
5602 end Find_Unary_Types;
5608 function Junk_Operand (N : Node_Id) return Boolean is
5612 if Error_Posted (N) then
5616 -- Get entity to be tested
5618 if Is_Entity_Name (N)
5619 and then Present (Entity (N))
5623 -- An odd case, a procedure name gets converted to a very peculiar
5624 -- function call, and here is where we detect this happening.
5626 elsif Nkind (N) = N_Function_Call
5627 and then Is_Entity_Name (Name (N))
5628 and then Present (Entity (Name (N)))
5632 -- Another odd case, there are at least some cases of selected
5633 -- components where the selected component is not marked as having
5634 -- an entity, even though the selector does have an entity
5636 elsif Nkind (N) = N_Selected_Component
5637 and then Present (Entity (Selector_Name (N)))
5639 Enode := Selector_Name (N);
5645 -- Now test the entity we got to see if it is a bad case
5647 case Ekind (Entity (Enode)) is
5651 ("package name cannot be used as operand", Enode);
5653 when Generic_Unit_Kind =>
5655 ("generic unit name cannot be used as operand", Enode);
5659 ("subtype name cannot be used as operand", Enode);
5663 ("entry name cannot be used as operand", Enode);
5667 ("procedure name cannot be used as operand", Enode);
5671 ("exception name cannot be used as operand", Enode);
5673 when E_Block | E_Label | E_Loop =>
5675 ("label name cannot be used as operand", Enode);
5685 --------------------
5686 -- Operator_Check --
5687 --------------------
5689 procedure Operator_Check (N : Node_Id) is
5691 Remove_Abstract_Operations (N);
5693 -- Test for case of no interpretation found for operator
5695 if Etype (N) = Any_Type then
5699 Op_Id : Entity_Id := Empty;
5702 R := Right_Opnd (N);
5704 if Nkind (N) in N_Binary_Op then
5710 -- If either operand has no type, then don't complain further,
5711 -- since this simply means that we have a propagated error.
5714 or else Etype (R) = Any_Type
5715 or else (Nkind (N) in N_Binary_Op and then Etype (L) = Any_Type)
5719 -- We explicitly check for the case of concatenation of component
5720 -- with component to avoid reporting spurious matching array types
5721 -- that might happen to be lurking in distant packages (such as
5722 -- run-time packages). This also prevents inconsistencies in the
5723 -- messages for certain ACVC B tests, which can vary depending on
5724 -- types declared in run-time interfaces. Another improvement when
5725 -- aggregates are present is to look for a well-typed operand.
5727 elsif Present (Candidate_Type)
5728 and then (Nkind (N) /= N_Op_Concat
5729 or else Is_Array_Type (Etype (L))
5730 or else Is_Array_Type (Etype (R)))
5732 if Nkind (N) = N_Op_Concat then
5733 if Etype (L) /= Any_Composite
5734 and then Is_Array_Type (Etype (L))
5736 Candidate_Type := Etype (L);
5738 elsif Etype (R) /= Any_Composite
5739 and then Is_Array_Type (Etype (R))
5741 Candidate_Type := Etype (R);
5745 Error_Msg_NE -- CODEFIX
5746 ("operator for} is not directly visible!",
5747 N, First_Subtype (Candidate_Type));
5750 U : constant Node_Id :=
5751 Cunit (Get_Source_Unit (Candidate_Type));
5753 if Unit_Is_Visible (U) then
5754 Error_Msg_N -- CODEFIX
5755 ("use clause would make operation legal!", N);
5757 Error_Msg_NE -- CODEFIX
5758 ("add with_clause and use_clause for&!",
5759 N, Defining_Entity (Unit (U)));
5764 -- If either operand is a junk operand (e.g. package name), then
5765 -- post appropriate error messages, but do not complain further.
5767 -- Note that the use of OR in this test instead of OR ELSE is
5768 -- quite deliberate, we may as well check both operands in the
5769 -- binary operator case.
5771 elsif Junk_Operand (R)
5772 or (Nkind (N) in N_Binary_Op and then Junk_Operand (L))
5776 -- If we have a logical operator, one of whose operands is
5777 -- Boolean, then we know that the other operand cannot resolve to
5778 -- Boolean (since we got no interpretations), but in that case we
5779 -- pretty much know that the other operand should be Boolean, so
5780 -- resolve it that way (generating an error)
5782 elsif Nkind_In (N, N_Op_And, N_Op_Or, N_Op_Xor) then
5783 if Etype (L) = Standard_Boolean then
5784 Resolve (R, Standard_Boolean);
5786 elsif Etype (R) = Standard_Boolean then
5787 Resolve (L, Standard_Boolean);
5791 -- For an arithmetic operator or comparison operator, if one
5792 -- of the operands is numeric, then we know the other operand
5793 -- is not the same numeric type. If it is a non-numeric type,
5794 -- then probably it is intended to match the other operand.
5796 elsif Nkind_In (N, N_Op_Add,
5802 Nkind_In (N, N_Op_Lt,
5808 if Is_Numeric_Type (Etype (L))
5809 and then not Is_Numeric_Type (Etype (R))
5811 Resolve (R, Etype (L));
5814 elsif Is_Numeric_Type (Etype (R))
5815 and then not Is_Numeric_Type (Etype (L))
5817 Resolve (L, Etype (R));
5821 -- Comparisons on A'Access are common enough to deserve a
5824 elsif Nkind_In (N, N_Op_Eq, N_Op_Ne)
5825 and then Ekind (Etype (L)) = E_Access_Attribute_Type
5826 and then Ekind (Etype (R)) = E_Access_Attribute_Type
5829 ("two access attributes cannot be compared directly", N);
5831 ("\use qualified expression for one of the operands",
5835 -- Another one for C programmers
5837 elsif Nkind (N) = N_Op_Concat
5838 and then Valid_Boolean_Arg (Etype (L))
5839 and then Valid_Boolean_Arg (Etype (R))
5841 Error_Msg_N ("invalid operands for concatenation", N);
5842 Error_Msg_N -- CODEFIX
5843 ("\maybe AND was meant", N);
5846 -- A special case for comparison of access parameter with null
5848 elsif Nkind (N) = N_Op_Eq
5849 and then Is_Entity_Name (L)
5850 and then Nkind (Parent (Entity (L))) = N_Parameter_Specification
5851 and then Nkind (Parameter_Type (Parent (Entity (L)))) =
5853 and then Nkind (R) = N_Null
5855 Error_Msg_N ("access parameter is not allowed to be null", L);
5856 Error_Msg_N ("\(call would raise Constraint_Error)", L);
5859 -- Another special case for exponentiation, where the right
5860 -- operand must be Natural, independently of the base.
5862 elsif Nkind (N) = N_Op_Expon
5863 and then Is_Numeric_Type (Etype (L))
5864 and then not Is_Overloaded (R)
5866 First_Subtype (Base_Type (Etype (R))) /= Standard_Integer
5867 and then Base_Type (Etype (R)) /= Universal_Integer
5870 ("exponent must be of type Natural, found}", R, Etype (R));
5874 -- If we fall through then just give general message. Note that in
5875 -- the following messages, if the operand is overloaded we choose
5876 -- an arbitrary type to complain about, but that is probably more
5877 -- useful than not giving a type at all.
5879 if Nkind (N) in N_Unary_Op then
5880 Error_Msg_Node_2 := Etype (R);
5881 Error_Msg_N ("operator& not defined for}", N);
5885 if Nkind (N) in N_Binary_Op then
5886 if not Is_Overloaded (L)
5887 and then not Is_Overloaded (R)
5888 and then Base_Type (Etype (L)) = Base_Type (Etype (R))
5890 Error_Msg_Node_2 := First_Subtype (Etype (R));
5891 Error_Msg_N ("there is no applicable operator& for}", N);
5894 -- Another attempt to find a fix: one of the candidate
5895 -- interpretations may not be use-visible. This has
5896 -- already been checked for predefined operators, so
5897 -- we examine only user-defined functions.
5899 Op_Id := Get_Name_Entity_Id (Chars (N));
5901 while Present (Op_Id) loop
5902 if Ekind (Op_Id) /= E_Operator
5903 and then Is_Overloadable (Op_Id)
5905 if not Is_Immediately_Visible (Op_Id)
5906 and then not In_Use (Scope (Op_Id))
5907 and then not Is_Abstract_Subprogram (Op_Id)
5908 and then not Is_Hidden (Op_Id)
5909 and then Ekind (Scope (Op_Id)) = E_Package
5912 (L, Etype (First_Formal (Op_Id)))
5914 (Next_Formal (First_Formal (Op_Id)))
5918 Etype (Next_Formal (First_Formal (Op_Id))))
5921 ("No legal interpretation for operator&", N);
5923 ("\use clause on& would make operation legal",
5929 Op_Id := Homonym (Op_Id);
5933 Error_Msg_N ("invalid operand types for operator&", N);
5935 if Nkind (N) /= N_Op_Concat then
5936 Error_Msg_NE ("\left operand has}!", N, Etype (L));
5937 Error_Msg_NE ("\right operand has}!", N, Etype (R));
5947 -----------------------------------------
5948 -- Process_Implicit_Dereference_Prefix --
5949 -----------------------------------------
5951 function Process_Implicit_Dereference_Prefix
5953 P : Entity_Id) return Entity_Id
5956 Typ : constant Entity_Id := Designated_Type (Etype (P));
5960 and then (Operating_Mode = Check_Semantics or else not Expander_Active)
5962 -- We create a dummy reference to E to ensure that the reference
5963 -- is not considered as part of an assignment (an implicit
5964 -- dereference can never assign to its prefix). The Comes_From_Source
5965 -- attribute needs to be propagated for accurate warnings.
5967 Ref := New_Reference_To (E, Sloc (P));
5968 Set_Comes_From_Source (Ref, Comes_From_Source (P));
5969 Generate_Reference (E, Ref);
5972 -- An implicit dereference is a legal occurrence of an
5973 -- incomplete type imported through a limited_with clause,
5974 -- if the full view is visible.
5976 if From_With_Type (Typ)
5977 and then not From_With_Type (Scope (Typ))
5979 (Is_Immediately_Visible (Scope (Typ))
5981 (Is_Child_Unit (Scope (Typ))
5982 and then Is_Visible_Child_Unit (Scope (Typ))))
5984 return Available_View (Typ);
5989 end Process_Implicit_Dereference_Prefix;
5991 --------------------------------
5992 -- Remove_Abstract_Operations --
5993 --------------------------------
5995 procedure Remove_Abstract_Operations (N : Node_Id) is
5996 Abstract_Op : Entity_Id := Empty;
5997 Address_Kludge : Boolean := False;
6001 -- AI-310: If overloaded, remove abstract non-dispatching operations. We
6002 -- activate this if either extensions are enabled, or if the abstract
6003 -- operation in question comes from a predefined file. This latter test
6004 -- allows us to use abstract to make operations invisible to users. In
6005 -- particular, if type Address is non-private and abstract subprograms
6006 -- are used to hide its operators, they will be truly hidden.
6008 type Operand_Position is (First_Op, Second_Op);
6009 Univ_Type : constant Entity_Id := Universal_Interpretation (N);
6011 procedure Remove_Address_Interpretations (Op : Operand_Position);
6012 -- Ambiguities may arise when the operands are literal and the address
6013 -- operations in s-auxdec are visible. In that case, remove the
6014 -- interpretation of a literal as Address, to retain the semantics of
6015 -- Address as a private type.
6017 ------------------------------------
6018 -- Remove_Address_Interpretations --
6019 ------------------------------------
6021 procedure Remove_Address_Interpretations (Op : Operand_Position) is
6025 if Is_Overloaded (N) then
6026 Get_First_Interp (N, I, It);
6027 while Present (It.Nam) loop
6028 Formal := First_Entity (It.Nam);
6030 if Op = Second_Op then
6031 Formal := Next_Entity (Formal);
6034 if Is_Descendent_Of_Address (Etype (Formal)) then
6035 Address_Kludge := True;
6039 Get_Next_Interp (I, It);
6042 end Remove_Address_Interpretations;
6044 -- Start of processing for Remove_Abstract_Operations
6047 if Is_Overloaded (N) then
6048 Get_First_Interp (N, I, It);
6050 while Present (It.Nam) loop
6051 if Is_Overloadable (It.Nam)
6052 and then Is_Abstract_Subprogram (It.Nam)
6053 and then not Is_Dispatching_Operation (It.Nam)
6055 Abstract_Op := It.Nam;
6057 if Is_Descendent_Of_Address (It.Typ) then
6058 Address_Kludge := True;
6062 -- In Ada 2005, this operation does not participate in Overload
6063 -- resolution. If the operation is defined in a predefined
6064 -- unit, it is one of the operations declared abstract in some
6065 -- variants of System, and it must be removed as well.
6067 elsif Ada_Version >= Ada_2005
6068 or else Is_Predefined_File_Name
6069 (Unit_File_Name (Get_Source_Unit (It.Nam)))
6076 Get_Next_Interp (I, It);
6079 if No (Abstract_Op) then
6081 -- If some interpretation yields an integer type, it is still
6082 -- possible that there are address interpretations. Remove them
6083 -- if one operand is a literal, to avoid spurious ambiguities
6084 -- on systems where Address is a visible integer type.
6086 if Is_Overloaded (N)
6087 and then Nkind (N) in N_Op
6088 and then Is_Integer_Type (Etype (N))
6090 if Nkind (N) in N_Binary_Op then
6091 if Nkind (Right_Opnd (N)) = N_Integer_Literal then
6092 Remove_Address_Interpretations (Second_Op);
6094 elsif Nkind (Right_Opnd (N)) = N_Integer_Literal then
6095 Remove_Address_Interpretations (First_Op);
6100 elsif Nkind (N) in N_Op then
6102 -- Remove interpretations that treat literals as addresses. This
6103 -- is never appropriate, even when Address is defined as a visible
6104 -- Integer type. The reason is that we would really prefer Address
6105 -- to behave as a private type, even in this case, which is there
6106 -- only to accommodate oddities of VMS address sizes. If Address
6107 -- is a visible integer type, we get lots of overload ambiguities.
6109 if Nkind (N) in N_Binary_Op then
6111 U1 : constant Boolean :=
6112 Present (Universal_Interpretation (Right_Opnd (N)));
6113 U2 : constant Boolean :=
6114 Present (Universal_Interpretation (Left_Opnd (N)));
6118 Remove_Address_Interpretations (Second_Op);
6122 Remove_Address_Interpretations (First_Op);
6125 if not (U1 and U2) then
6127 -- Remove corresponding predefined operator, which is
6128 -- always added to the overload set.
6130 Get_First_Interp (N, I, It);
6131 while Present (It.Nam) loop
6132 if Scope (It.Nam) = Standard_Standard
6133 and then Base_Type (It.Typ) =
6134 Base_Type (Etype (Abstract_Op))
6139 Get_Next_Interp (I, It);
6142 elsif Is_Overloaded (N)
6143 and then Present (Univ_Type)
6145 -- If both operands have a universal interpretation,
6146 -- it is still necessary to remove interpretations that
6147 -- yield Address. Any remaining ambiguities will be
6148 -- removed in Disambiguate.
6150 Get_First_Interp (N, I, It);
6151 while Present (It.Nam) loop
6152 if Is_Descendent_Of_Address (It.Typ) then
6155 elsif not Is_Type (It.Nam) then
6156 Set_Entity (N, It.Nam);
6159 Get_Next_Interp (I, It);
6165 elsif Nkind (N) = N_Function_Call
6167 (Nkind (Name (N)) = N_Operator_Symbol
6169 (Nkind (Name (N)) = N_Expanded_Name
6171 Nkind (Selector_Name (Name (N))) = N_Operator_Symbol))
6175 Arg1 : constant Node_Id := First (Parameter_Associations (N));
6176 U1 : constant Boolean :=
6177 Present (Universal_Interpretation (Arg1));
6178 U2 : constant Boolean :=
6179 Present (Next (Arg1)) and then
6180 Present (Universal_Interpretation (Next (Arg1)));
6184 Remove_Address_Interpretations (First_Op);
6188 Remove_Address_Interpretations (Second_Op);
6191 if not (U1 and U2) then
6192 Get_First_Interp (N, I, It);
6193 while Present (It.Nam) loop
6194 if Scope (It.Nam) = Standard_Standard
6195 and then It.Typ = Base_Type (Etype (Abstract_Op))
6200 Get_Next_Interp (I, It);
6206 -- If the removal has left no valid interpretations, emit an error
6207 -- message now and label node as illegal.
6209 if Present (Abstract_Op) then
6210 Get_First_Interp (N, I, It);
6214 -- Removal of abstract operation left no viable candidate
6216 Set_Etype (N, Any_Type);
6217 Error_Msg_Sloc := Sloc (Abstract_Op);
6219 ("cannot call abstract operation& declared#", N, Abstract_Op);
6221 -- In Ada 2005, an abstract operation may disable predefined
6222 -- operators. Since the context is not yet known, we mark the
6223 -- predefined operators as potentially hidden. Do not include
6224 -- predefined operators when addresses are involved since this
6225 -- case is handled separately.
6227 elsif Ada_Version >= Ada_2005
6228 and then not Address_Kludge
6230 while Present (It.Nam) loop
6231 if Is_Numeric_Type (It.Typ)
6232 and then Scope (It.Typ) = Standard_Standard
6234 Set_Abstract_Op (I, Abstract_Op);
6237 Get_Next_Interp (I, It);
6242 end Remove_Abstract_Operations;
6244 -----------------------
6245 -- Try_Indirect_Call --
6246 -----------------------
6248 function Try_Indirect_Call
6251 Typ : Entity_Id) return Boolean
6257 pragma Warnings (Off, Call_OK);
6260 Normalize_Actuals (N, Designated_Type (Typ), False, Call_OK);
6262 Actual := First_Actual (N);
6263 Formal := First_Formal (Designated_Type (Typ));
6264 while Present (Actual) and then Present (Formal) loop
6265 if not Has_Compatible_Type (Actual, Etype (Formal)) then
6270 Next_Formal (Formal);
6273 if No (Actual) and then No (Formal) then
6274 Add_One_Interp (N, Nam, Etype (Designated_Type (Typ)));
6276 -- Nam is a candidate interpretation for the name in the call,
6277 -- if it is not an indirect call.
6279 if not Is_Type (Nam)
6280 and then Is_Entity_Name (Name (N))
6282 Set_Entity (Name (N), Nam);
6289 end Try_Indirect_Call;
6291 ----------------------
6292 -- Try_Indexed_Call --
6293 ----------------------
6295 function Try_Indexed_Call
6299 Skip_First : Boolean) return Boolean
6301 Loc : constant Source_Ptr := Sloc (N);
6302 Actuals : constant List_Id := Parameter_Associations (N);
6307 Actual := First (Actuals);
6309 -- If the call was originally written in prefix form, skip the first
6310 -- actual, which is obviously not defaulted.
6316 Index := First_Index (Typ);
6317 while Present (Actual) and then Present (Index) loop
6319 -- If the parameter list has a named association, the expression
6320 -- is definitely a call and not an indexed component.
6322 if Nkind (Actual) = N_Parameter_Association then
6326 if Is_Entity_Name (Actual)
6327 and then Is_Type (Entity (Actual))
6328 and then No (Next (Actual))
6330 -- A single actual that is a type name indicates a slice if the
6331 -- type is discrete, and an error otherwise.
6333 if Is_Discrete_Type (Entity (Actual)) then
6337 Make_Function_Call (Loc,
6338 Name => Relocate_Node (Name (N))),
6340 New_Occurrence_Of (Entity (Actual), Sloc (Actual))));
6345 Error_Msg_N ("invalid use of type in expression", Actual);
6346 Set_Etype (N, Any_Type);
6351 elsif not Has_Compatible_Type (Actual, Etype (Index)) then
6359 if No (Actual) and then No (Index) then
6360 Add_One_Interp (N, Nam, Component_Type (Typ));
6362 -- Nam is a candidate interpretation for the name in the call,
6363 -- if it is not an indirect call.
6365 if not Is_Type (Nam)
6366 and then Is_Entity_Name (Name (N))
6368 Set_Entity (Name (N), Nam);
6375 end Try_Indexed_Call;
6377 --------------------------
6378 -- Try_Object_Operation --
6379 --------------------------
6381 function Try_Object_Operation (N : Node_Id) return Boolean is
6382 K : constant Node_Kind := Nkind (Parent (N));
6383 Is_Subprg_Call : constant Boolean := Nkind_In
6384 (K, N_Procedure_Call_Statement,
6386 Loc : constant Source_Ptr := Sloc (N);
6387 Obj : constant Node_Id := Prefix (N);
6389 Subprog : constant Node_Id :=
6390 Make_Identifier (Sloc (Selector_Name (N)),
6391 Chars => Chars (Selector_Name (N)));
6392 -- Identifier on which possible interpretations will be collected
6394 Report_Error : Boolean := False;
6395 -- If no candidate interpretation matches the context, redo the
6396 -- analysis with error enabled to provide additional information.
6399 Candidate : Entity_Id := Empty;
6400 New_Call_Node : Node_Id := Empty;
6401 Node_To_Replace : Node_Id;
6402 Obj_Type : Entity_Id := Etype (Obj);
6403 Success : Boolean := False;
6405 function Valid_Candidate
6408 Subp : Entity_Id) return Entity_Id;
6409 -- If the subprogram is a valid interpretation, record it, and add
6410 -- to the list of interpretations of Subprog.
6412 procedure Complete_Object_Operation
6413 (Call_Node : Node_Id;
6414 Node_To_Replace : Node_Id);
6415 -- Make Subprog the name of Call_Node, replace Node_To_Replace with
6416 -- Call_Node, insert the object (or its dereference) as the first actual
6417 -- in the call, and complete the analysis of the call.
6419 procedure Report_Ambiguity (Op : Entity_Id);
6420 -- If a prefixed procedure call is ambiguous, indicate whether the
6421 -- call includes an implicit dereference or an implicit 'Access.
6423 procedure Transform_Object_Operation
6424 (Call_Node : out Node_Id;
6425 Node_To_Replace : out Node_Id);
6426 -- Transform Obj.Operation (X, Y,,) into Operation (Obj, X, Y ..)
6427 -- Call_Node is the resulting subprogram call, Node_To_Replace is
6428 -- either N or the parent of N, and Subprog is a reference to the
6429 -- subprogram we are trying to match.
6431 function Try_Class_Wide_Operation
6432 (Call_Node : Node_Id;
6433 Node_To_Replace : Node_Id) return Boolean;
6434 -- Traverse all ancestor types looking for a class-wide subprogram
6435 -- for which the current operation is a valid non-dispatching call.
6437 procedure Try_One_Prefix_Interpretation (T : Entity_Id);
6438 -- If prefix is overloaded, its interpretation may include different
6439 -- tagged types, and we must examine the primitive operations and
6440 -- the class-wide operations of each in order to find candidate
6441 -- interpretations for the call as a whole.
6443 function Try_Primitive_Operation
6444 (Call_Node : Node_Id;
6445 Node_To_Replace : Node_Id) return Boolean;
6446 -- Traverse the list of primitive subprograms looking for a dispatching
6447 -- operation for which the current node is a valid call .
6449 ---------------------
6450 -- Valid_Candidate --
6451 ---------------------
6453 function Valid_Candidate
6456 Subp : Entity_Id) return Entity_Id
6458 Arr_Type : Entity_Id;
6459 Comp_Type : Entity_Id;
6462 -- If the subprogram is a valid interpretation, record it in global
6463 -- variable Subprog, to collect all possible overloadings.
6466 if Subp /= Entity (Subprog) then
6467 Add_One_Interp (Subprog, Subp, Etype (Subp));
6471 -- If the call may be an indexed call, retrieve component type of
6472 -- resulting expression, and add possible interpretation.
6477 if Nkind (Call) = N_Function_Call
6478 and then Nkind (Parent (N)) = N_Indexed_Component
6479 and then Needs_One_Actual (Subp)
6481 if Is_Array_Type (Etype (Subp)) then
6482 Arr_Type := Etype (Subp);
6484 elsif Is_Access_Type (Etype (Subp))
6485 and then Is_Array_Type (Designated_Type (Etype (Subp)))
6487 Arr_Type := Designated_Type (Etype (Subp));
6491 if Present (Arr_Type) then
6493 -- Verify that the actuals (excluding the object) match the types
6501 Actual := Next (First_Actual (Call));
6502 Index := First_Index (Arr_Type);
6503 while Present (Actual) and then Present (Index) loop
6504 if not Has_Compatible_Type (Actual, Etype (Index)) then
6509 Next_Actual (Actual);
6515 and then Present (Arr_Type)
6517 Comp_Type := Component_Type (Arr_Type);
6521 if Present (Comp_Type)
6522 and then Etype (Subprog) /= Comp_Type
6524 Add_One_Interp (Subprog, Subp, Comp_Type);
6528 if Etype (Call) /= Any_Type then
6533 end Valid_Candidate;
6535 -------------------------------
6536 -- Complete_Object_Operation --
6537 -------------------------------
6539 procedure Complete_Object_Operation
6540 (Call_Node : Node_Id;
6541 Node_To_Replace : Node_Id)
6543 Control : constant Entity_Id := First_Formal (Entity (Subprog));
6544 Formal_Type : constant Entity_Id := Etype (Control);
6545 First_Actual : Node_Id;
6548 -- Place the name of the operation, with its interpretations,
6549 -- on the rewritten call.
6551 Set_Name (Call_Node, Subprog);
6553 First_Actual := First (Parameter_Associations (Call_Node));
6555 -- For cross-reference purposes, treat the new node as being in
6556 -- the source if the original one is.
6558 Set_Comes_From_Source (Subprog, Comes_From_Source (N));
6559 Set_Comes_From_Source (Call_Node, Comes_From_Source (N));
6561 if Nkind (N) = N_Selected_Component
6562 and then not Inside_A_Generic
6564 Set_Entity (Selector_Name (N), Entity (Subprog));
6567 -- If need be, rewrite first actual as an explicit dereference
6568 -- If the call is overloaded, the rewriting can only be done
6569 -- once the primitive operation is identified.
6571 if Is_Overloaded (Subprog) then
6573 -- The prefix itself may be overloaded, and its interpretations
6574 -- must be propagated to the new actual in the call.
6576 if Is_Overloaded (Obj) then
6577 Save_Interps (Obj, First_Actual);
6580 Rewrite (First_Actual, Obj);
6582 elsif not Is_Access_Type (Formal_Type)
6583 and then Is_Access_Type (Etype (Obj))
6585 Rewrite (First_Actual,
6586 Make_Explicit_Dereference (Sloc (Obj), Obj));
6587 Analyze (First_Actual);
6589 -- If we need to introduce an explicit dereference, verify that
6590 -- the resulting actual is compatible with the mode of the formal.
6592 if Ekind (First_Formal (Entity (Subprog))) /= E_In_Parameter
6593 and then Is_Access_Constant (Etype (Obj))
6596 ("expect variable in call to&", Prefix (N), Entity (Subprog));
6599 -- Conversely, if the formal is an access parameter and the object
6600 -- is not, replace the actual with a 'Access reference. Its analysis
6601 -- will check that the object is aliased.
6603 elsif Is_Access_Type (Formal_Type)
6604 and then not Is_Access_Type (Etype (Obj))
6606 -- A special case: A.all'access is illegal if A is an access to a
6607 -- constant and the context requires an access to a variable.
6609 if not Is_Access_Constant (Formal_Type) then
6610 if (Nkind (Obj) = N_Explicit_Dereference
6611 and then Is_Access_Constant (Etype (Prefix (Obj))))
6612 or else not Is_Variable (Obj)
6615 ("actual for& must be a variable", Obj, Control);
6619 Rewrite (First_Actual,
6620 Make_Attribute_Reference (Loc,
6621 Attribute_Name => Name_Access,
6622 Prefix => Relocate_Node (Obj)));
6624 if not Is_Aliased_View (Obj) then
6626 ("object in prefixed call to& must be aliased"
6627 & " (RM-2005 4.3.1 (13))",
6628 Prefix (First_Actual), Subprog);
6631 Analyze (First_Actual);
6634 if Is_Overloaded (Obj) then
6635 Save_Interps (Obj, First_Actual);
6638 Rewrite (First_Actual, Obj);
6641 Rewrite (Node_To_Replace, Call_Node);
6643 -- Propagate the interpretations collected in subprog to the new
6644 -- function call node, to be resolved from context.
6646 if Is_Overloaded (Subprog) then
6647 Save_Interps (Subprog, Node_To_Replace);
6650 Analyze (Node_To_Replace);
6652 -- If the operation has been rewritten into a call, which may get
6653 -- subsequently an explicit dereference, preserve the type on the
6654 -- original node (selected component or indexed component) for
6655 -- subsequent legality tests, e.g. Is_Variable. which examines
6656 -- the original node.
6658 if Nkind (Node_To_Replace) = N_Function_Call then
6660 (Original_Node (Node_To_Replace), Etype (Node_To_Replace));
6663 end Complete_Object_Operation;
6665 ----------------------
6666 -- Report_Ambiguity --
6667 ----------------------
6669 procedure Report_Ambiguity (Op : Entity_Id) is
6670 Access_Formal : constant Boolean :=
6671 Is_Access_Type (Etype (First_Formal (Op)));
6672 Access_Actual : constant Boolean :=
6673 Is_Access_Type (Etype (Prefix (N)));
6676 Error_Msg_Sloc := Sloc (Op);
6678 if Access_Formal and then not Access_Actual then
6679 if Nkind (Parent (Op)) = N_Full_Type_Declaration then
6681 ("\possible interpretation"
6682 & " (inherited, with implicit 'Access) #", N);
6685 ("\possible interpretation (with implicit 'Access) #", N);
6688 elsif not Access_Formal and then Access_Actual then
6689 if Nkind (Parent (Op)) = N_Full_Type_Declaration then
6691 ("\possible interpretation"
6692 & " ( inherited, with implicit dereference) #", N);
6695 ("\possible interpretation (with implicit dereference) #", N);
6699 if Nkind (Parent (Op)) = N_Full_Type_Declaration then
6700 Error_Msg_N ("\possible interpretation (inherited)#", N);
6702 Error_Msg_N -- CODEFIX
6703 ("\possible interpretation#", N);
6706 end Report_Ambiguity;
6708 --------------------------------
6709 -- Transform_Object_Operation --
6710 --------------------------------
6712 procedure Transform_Object_Operation
6713 (Call_Node : out Node_Id;
6714 Node_To_Replace : out Node_Id)
6716 Dummy : constant Node_Id := New_Copy (Obj);
6717 -- Placeholder used as a first parameter in the call, replaced
6718 -- eventually by the proper object.
6720 Parent_Node : constant Node_Id := Parent (N);
6726 -- Common case covering 1) Call to a procedure and 2) Call to a
6727 -- function that has some additional actuals.
6729 if Nkind_In (Parent_Node, N_Function_Call,
6730 N_Procedure_Call_Statement)
6732 -- N is a selected component node containing the name of the
6733 -- subprogram. If N is not the name of the parent node we must
6734 -- not replace the parent node by the new construct. This case
6735 -- occurs when N is a parameterless call to a subprogram that
6736 -- is an actual parameter of a call to another subprogram. For
6738 -- Some_Subprogram (..., Obj.Operation, ...)
6740 and then Name (Parent_Node) = N
6742 Node_To_Replace := Parent_Node;
6744 Actuals := Parameter_Associations (Parent_Node);
6746 if Present (Actuals) then
6747 Prepend (Dummy, Actuals);
6749 Actuals := New_List (Dummy);
6752 if Nkind (Parent_Node) = N_Procedure_Call_Statement then
6754 Make_Procedure_Call_Statement (Loc,
6755 Name => New_Copy (Subprog),
6756 Parameter_Associations => Actuals);
6760 Make_Function_Call (Loc,
6761 Name => New_Copy (Subprog),
6762 Parameter_Associations => Actuals);
6766 -- Before analysis, a function call appears as an indexed component
6767 -- if there are no named associations.
6769 elsif Nkind (Parent_Node) = N_Indexed_Component
6770 and then N = Prefix (Parent_Node)
6772 Node_To_Replace := Parent_Node;
6773 Actuals := Expressions (Parent_Node);
6775 Actual := First (Actuals);
6776 while Present (Actual) loop
6781 Prepend (Dummy, Actuals);
6784 Make_Function_Call (Loc,
6785 Name => New_Copy (Subprog),
6786 Parameter_Associations => Actuals);
6788 -- Parameterless call: Obj.F is rewritten as F (Obj)
6791 Node_To_Replace := N;
6794 Make_Function_Call (Loc,
6795 Name => New_Copy (Subprog),
6796 Parameter_Associations => New_List (Dummy));
6798 end Transform_Object_Operation;
6800 ------------------------------
6801 -- Try_Class_Wide_Operation --
6802 ------------------------------
6804 function Try_Class_Wide_Operation
6805 (Call_Node : Node_Id;
6806 Node_To_Replace : Node_Id) return Boolean
6808 Anc_Type : Entity_Id;
6809 Matching_Op : Entity_Id := Empty;
6812 procedure Traverse_Homonyms
6813 (Anc_Type : Entity_Id;
6814 Error : out Boolean);
6815 -- Traverse the homonym chain of the subprogram searching for those
6816 -- homonyms whose first formal has the Anc_Type's class-wide type,
6817 -- or an anonymous access type designating the class-wide type. If
6818 -- an ambiguity is detected, then Error is set to True.
6820 procedure Traverse_Interfaces
6821 (Anc_Type : Entity_Id;
6822 Error : out Boolean);
6823 -- Traverse the list of interfaces, if any, associated with Anc_Type
6824 -- and search for acceptable class-wide homonyms associated with each
6825 -- interface. If an ambiguity is detected, then Error is set to True.
6827 -----------------------
6828 -- Traverse_Homonyms --
6829 -----------------------
6831 procedure Traverse_Homonyms
6832 (Anc_Type : Entity_Id;
6833 Error : out Boolean)
6835 Cls_Type : Entity_Id;
6843 Cls_Type := Class_Wide_Type (Anc_Type);
6845 Hom := Current_Entity (Subprog);
6847 -- Find a non-hidden operation whose first parameter is of the
6848 -- class-wide type, a subtype thereof, or an anonymous access
6851 while Present (Hom) loop
6852 if Ekind_In (Hom, E_Procedure, E_Function)
6853 and then not Is_Hidden (Hom)
6854 and then Scope (Hom) = Scope (Anc_Type)
6855 and then Present (First_Formal (Hom))
6857 (Base_Type (Etype (First_Formal (Hom))) = Cls_Type
6859 (Is_Access_Type (Etype (First_Formal (Hom)))
6861 Ekind (Etype (First_Formal (Hom))) =
6862 E_Anonymous_Access_Type
6865 (Designated_Type (Etype (First_Formal (Hom)))) =
6868 Set_Etype (Call_Node, Any_Type);
6869 Set_Is_Overloaded (Call_Node, False);
6872 if No (Matching_Op) then
6873 Hom_Ref := New_Reference_To (Hom, Sloc (Subprog));
6874 Set_Etype (Call_Node, Any_Type);
6875 Set_Parent (Call_Node, Parent (Node_To_Replace));
6877 Set_Name (Call_Node, Hom_Ref);
6882 Report => Report_Error,
6884 Skip_First => True);
6887 Valid_Candidate (Success, Call_Node, Hom);
6893 Report => Report_Error,
6895 Skip_First => True);
6897 if Present (Valid_Candidate (Success, Call_Node, Hom))
6898 and then Nkind (Call_Node) /= N_Function_Call
6900 Error_Msg_NE ("ambiguous call to&", N, Hom);
6901 Report_Ambiguity (Matching_Op);
6902 Report_Ambiguity (Hom);
6909 Hom := Homonym (Hom);
6911 end Traverse_Homonyms;
6913 -------------------------
6914 -- Traverse_Interfaces --
6915 -------------------------
6917 procedure Traverse_Interfaces
6918 (Anc_Type : Entity_Id;
6919 Error : out Boolean)
6921 Intface_List : constant List_Id :=
6922 Abstract_Interface_List (Anc_Type);
6928 if Is_Non_Empty_List (Intface_List) then
6929 Intface := First (Intface_List);
6930 while Present (Intface) loop
6932 -- Look for acceptable class-wide homonyms associated with
6935 Traverse_Homonyms (Etype (Intface), Error);
6941 -- Continue the search by looking at each of the interface's
6942 -- associated interface ancestors.
6944 Traverse_Interfaces (Etype (Intface), Error);
6953 end Traverse_Interfaces;
6955 -- Start of processing for Try_Class_Wide_Operation
6958 -- Loop through ancestor types (including interfaces), traversing
6959 -- the homonym chain of the subprogram, trying out those homonyms
6960 -- whose first formal has the class-wide type of the ancestor, or
6961 -- an anonymous access type designating the class-wide type.
6963 Anc_Type := Obj_Type;
6965 -- Look for a match among homonyms associated with the ancestor
6967 Traverse_Homonyms (Anc_Type, Error);
6973 -- Continue the search for matches among homonyms associated with
6974 -- any interfaces implemented by the ancestor.
6976 Traverse_Interfaces (Anc_Type, Error);
6982 exit when Etype (Anc_Type) = Anc_Type;
6983 Anc_Type := Etype (Anc_Type);
6986 if Present (Matching_Op) then
6987 Set_Etype (Call_Node, Etype (Matching_Op));
6990 return Present (Matching_Op);
6991 end Try_Class_Wide_Operation;
6993 -----------------------------------
6994 -- Try_One_Prefix_Interpretation --
6995 -----------------------------------
6997 procedure Try_One_Prefix_Interpretation (T : Entity_Id) is
7001 if Is_Access_Type (Obj_Type) then
7002 Obj_Type := Designated_Type (Obj_Type);
7005 if Ekind (Obj_Type) = E_Private_Subtype then
7006 Obj_Type := Base_Type (Obj_Type);
7009 if Is_Class_Wide_Type (Obj_Type) then
7010 Obj_Type := Etype (Class_Wide_Type (Obj_Type));
7013 -- The type may have be obtained through a limited_with clause,
7014 -- in which case the primitive operations are available on its
7015 -- non-limited view. If still incomplete, retrieve full view.
7017 if Ekind (Obj_Type) = E_Incomplete_Type
7018 and then From_With_Type (Obj_Type)
7020 Obj_Type := Get_Full_View (Non_Limited_View (Obj_Type));
7023 -- If the object is not tagged, or the type is still an incomplete
7024 -- type, this is not a prefixed call.
7026 if not Is_Tagged_Type (Obj_Type)
7027 or else Is_Incomplete_Type (Obj_Type)
7032 if Try_Primitive_Operation
7033 (Call_Node => New_Call_Node,
7034 Node_To_Replace => Node_To_Replace)
7036 Try_Class_Wide_Operation
7037 (Call_Node => New_Call_Node,
7038 Node_To_Replace => Node_To_Replace)
7042 end Try_One_Prefix_Interpretation;
7044 -----------------------------
7045 -- Try_Primitive_Operation --
7046 -----------------------------
7048 function Try_Primitive_Operation
7049 (Call_Node : Node_Id;
7050 Node_To_Replace : Node_Id) return Boolean
7053 Prim_Op : Entity_Id;
7054 Matching_Op : Entity_Id := Empty;
7055 Prim_Op_Ref : Node_Id := Empty;
7057 Corr_Type : Entity_Id := Empty;
7058 -- If the prefix is a synchronized type, the controlling type of
7059 -- the primitive operation is the corresponding record type, else
7060 -- this is the object type itself.
7062 Success : Boolean := False;
7064 function Collect_Generic_Type_Ops (T : Entity_Id) return Elist_Id;
7065 -- For tagged types the candidate interpretations are found in
7066 -- the list of primitive operations of the type and its ancestors.
7067 -- For formal tagged types we have to find the operations declared
7068 -- in the same scope as the type (including in the generic formal
7069 -- part) because the type itself carries no primitive operations,
7070 -- except for formal derived types that inherit the operations of
7071 -- the parent and progenitors.
7072 -- If the context is a generic subprogram body, the generic formals
7073 -- are visible by name, but are not in the entity list of the
7074 -- subprogram because that list starts with the subprogram formals.
7075 -- We retrieve the candidate operations from the generic declaration.
7077 function Is_Private_Overriding (Op : Entity_Id) return Boolean;
7078 -- An operation that overrides an inherited operation in the private
7079 -- part of its package may be hidden, but if the inherited operation
7080 -- is visible a direct call to it will dispatch to the private one,
7081 -- which is therefore a valid candidate.
7083 function Valid_First_Argument_Of (Op : Entity_Id) return Boolean;
7084 -- Verify that the prefix, dereferenced if need be, is a valid
7085 -- controlling argument in a call to Op. The remaining actuals
7086 -- are checked in the subsequent call to Analyze_One_Call.
7088 ------------------------------
7089 -- Collect_Generic_Type_Ops --
7090 ------------------------------
7092 function Collect_Generic_Type_Ops (T : Entity_Id) return Elist_Id is
7093 Bas : constant Entity_Id := Base_Type (T);
7094 Candidates : constant Elist_Id := New_Elmt_List;
7098 procedure Check_Candidate;
7099 -- The operation is a candidate if its first parameter is a
7100 -- controlling operand of the desired type.
7102 -----------------------
7103 -- Check_Candidate; --
7104 -----------------------
7106 procedure Check_Candidate is
7108 Formal := First_Formal (Subp);
7111 and then Is_Controlling_Formal (Formal)
7113 (Base_Type (Etype (Formal)) = Bas
7115 (Is_Access_Type (Etype (Formal))
7116 and then Designated_Type (Etype (Formal)) = Bas))
7118 Append_Elmt (Subp, Candidates);
7120 end Check_Candidate;
7122 -- Start of processing for Collect_Generic_Type_Ops
7125 if Is_Derived_Type (T) then
7126 return Primitive_Operations (T);
7128 elsif Ekind_In (Scope (T), E_Procedure, E_Function) then
7130 -- Scan the list of generic formals to find subprograms
7131 -- that may have a first controlling formal of the type.
7133 if Nkind (Unit_Declaration_Node (Scope (T)))
7134 = N_Generic_Subprogram_Declaration
7141 First (Generic_Formal_Declarations
7142 (Unit_Declaration_Node (Scope (T))));
7143 while Present (Decl) loop
7144 if Nkind (Decl) in N_Formal_Subprogram_Declaration then
7145 Subp := Defining_Entity (Decl);
7156 -- Scan the list of entities declared in the same scope as
7157 -- the type. In general this will be an open scope, given that
7158 -- the call we are analyzing can only appear within a generic
7159 -- declaration or body (either the one that declares T, or a
7162 -- For a subtype representing a generic actual type, go to the
7165 if Is_Generic_Actual_Type (T) then
7166 Subp := First_Entity (Scope (Base_Type (T)));
7168 Subp := First_Entity (Scope (T));
7171 while Present (Subp) loop
7172 if Is_Overloadable (Subp) then
7181 end Collect_Generic_Type_Ops;
7183 ---------------------------
7184 -- Is_Private_Overriding --
7185 ---------------------------
7187 function Is_Private_Overriding (Op : Entity_Id) return Boolean is
7188 Visible_Op : constant Entity_Id := Homonym (Op);
7191 return Present (Visible_Op)
7192 and then Scope (Op) = Scope (Visible_Op)
7193 and then not Comes_From_Source (Visible_Op)
7194 and then Alias (Visible_Op) = Op
7195 and then not Is_Hidden (Visible_Op);
7196 end Is_Private_Overriding;
7198 -----------------------------
7199 -- Valid_First_Argument_Of --
7200 -----------------------------
7202 function Valid_First_Argument_Of (Op : Entity_Id) return Boolean is
7203 Typ : Entity_Id := Etype (First_Formal (Op));
7206 if Is_Concurrent_Type (Typ)
7207 and then Present (Corresponding_Record_Type (Typ))
7209 Typ := Corresponding_Record_Type (Typ);
7212 -- Simple case. Object may be a subtype of the tagged type or
7213 -- may be the corresponding record of a synchronized type.
7215 return Obj_Type = Typ
7216 or else Base_Type (Obj_Type) = Typ
7217 or else Corr_Type = Typ
7219 -- Prefix can be dereferenced
7222 (Is_Access_Type (Corr_Type)
7223 and then Designated_Type (Corr_Type) = Typ)
7225 -- Formal is an access parameter, for which the object
7226 -- can provide an access.
7229 (Ekind (Typ) = E_Anonymous_Access_Type
7230 and then Designated_Type (Typ) = Base_Type (Corr_Type));
7231 end Valid_First_Argument_Of;
7233 -- Start of processing for Try_Primitive_Operation
7236 -- Look for subprograms in the list of primitive operations. The name
7237 -- must be identical, and the kind of call indicates the expected
7238 -- kind of operation (function or procedure). If the type is a
7239 -- (tagged) synchronized type, the primitive ops are attached to the
7240 -- corresponding record (base) type.
7242 if Is_Concurrent_Type (Obj_Type) then
7243 if Present (Corresponding_Record_Type (Obj_Type)) then
7244 Corr_Type := Base_Type (Corresponding_Record_Type (Obj_Type));
7245 Elmt := First_Elmt (Primitive_Operations (Corr_Type));
7247 Corr_Type := Obj_Type;
7248 Elmt := First_Elmt (Collect_Generic_Type_Ops (Obj_Type));
7251 elsif not Is_Generic_Type (Obj_Type) then
7252 Corr_Type := Obj_Type;
7253 Elmt := First_Elmt (Primitive_Operations (Obj_Type));
7256 Corr_Type := Obj_Type;
7257 Elmt := First_Elmt (Collect_Generic_Type_Ops (Obj_Type));
7260 while Present (Elmt) loop
7261 Prim_Op := Node (Elmt);
7263 if Chars (Prim_Op) = Chars (Subprog)
7264 and then Present (First_Formal (Prim_Op))
7265 and then Valid_First_Argument_Of (Prim_Op)
7267 (Nkind (Call_Node) = N_Function_Call)
7268 = (Ekind (Prim_Op) = E_Function)
7270 -- Ada 2005 (AI-251): If this primitive operation corresponds
7271 -- with an immediate ancestor interface there is no need to add
7272 -- it to the list of interpretations; the corresponding aliased
7273 -- primitive is also in this list of primitive operations and
7274 -- will be used instead.
7276 if (Present (Interface_Alias (Prim_Op))
7277 and then Is_Ancestor (Find_Dispatching_Type
7278 (Alias (Prim_Op)), Corr_Type))
7280 -- Do not consider hidden primitives unless the type is in an
7281 -- open scope or we are within an instance, where visibility
7282 -- is known to be correct, or else if this is an overriding
7283 -- operation in the private part for an inherited operation.
7285 or else (Is_Hidden (Prim_Op)
7286 and then not Is_Immediately_Visible (Obj_Type)
7287 and then not In_Instance
7288 and then not Is_Private_Overriding (Prim_Op))
7293 Set_Etype (Call_Node, Any_Type);
7294 Set_Is_Overloaded (Call_Node, False);
7296 if No (Matching_Op) then
7297 Prim_Op_Ref := New_Reference_To (Prim_Op, Sloc (Subprog));
7298 Candidate := Prim_Op;
7300 Set_Parent (Call_Node, Parent (Node_To_Replace));
7302 Set_Name (Call_Node, Prim_Op_Ref);
7308 Report => Report_Error,
7310 Skip_First => True);
7312 Matching_Op := Valid_Candidate (Success, Call_Node, Prim_Op);
7314 -- More than one interpretation, collect for subsequent
7315 -- disambiguation. If this is a procedure call and there
7316 -- is another match, report ambiguity now.
7322 Report => Report_Error,
7324 Skip_First => True);
7326 if Present (Valid_Candidate (Success, Call_Node, Prim_Op))
7327 and then Nkind (Call_Node) /= N_Function_Call
7329 Error_Msg_NE ("ambiguous call to&", N, Prim_Op);
7330 Report_Ambiguity (Matching_Op);
7331 Report_Ambiguity (Prim_Op);
7341 if Present (Matching_Op) then
7342 Set_Etype (Call_Node, Etype (Matching_Op));
7345 return Present (Matching_Op);
7346 end Try_Primitive_Operation;
7348 -- Start of processing for Try_Object_Operation
7351 Analyze_Expression (Obj);
7353 -- Analyze the actuals if node is known to be a subprogram call
7355 if Is_Subprg_Call and then N = Name (Parent (N)) then
7356 Actual := First (Parameter_Associations (Parent (N)));
7357 while Present (Actual) loop
7358 Analyze_Expression (Actual);
7363 -- Build a subprogram call node, using a copy of Obj as its first
7364 -- actual. This is a placeholder, to be replaced by an explicit
7365 -- dereference when needed.
7367 Transform_Object_Operation
7368 (Call_Node => New_Call_Node,
7369 Node_To_Replace => Node_To_Replace);
7371 Set_Etype (New_Call_Node, Any_Type);
7372 Set_Etype (Subprog, Any_Type);
7373 Set_Parent (New_Call_Node, Parent (Node_To_Replace));
7375 if not Is_Overloaded (Obj) then
7376 Try_One_Prefix_Interpretation (Obj_Type);
7383 Get_First_Interp (Obj, I, It);
7384 while Present (It.Nam) loop
7385 Try_One_Prefix_Interpretation (It.Typ);
7386 Get_Next_Interp (I, It);
7391 if Etype (New_Call_Node) /= Any_Type then
7392 Complete_Object_Operation
7393 (Call_Node => New_Call_Node,
7394 Node_To_Replace => Node_To_Replace);
7397 elsif Present (Candidate) then
7399 -- The argument list is not type correct. Re-analyze with error
7400 -- reporting enabled, and use one of the possible candidates.
7401 -- In All_Errors_Mode, re-analyze all failed interpretations.
7403 if All_Errors_Mode then
7404 Report_Error := True;
7405 if Try_Primitive_Operation
7406 (Call_Node => New_Call_Node,
7407 Node_To_Replace => Node_To_Replace)
7410 Try_Class_Wide_Operation
7411 (Call_Node => New_Call_Node,
7412 Node_To_Replace => Node_To_Replace)
7419 (N => New_Call_Node,
7423 Skip_First => True);
7426 -- No need for further errors
7431 -- There was no candidate operation, so report it as an error
7432 -- in the caller: Analyze_Selected_Component.
7436 end Try_Object_Operation;
7442 procedure wpo (T : Entity_Id) is
7447 if not Is_Tagged_Type (T) then
7451 E := First_Elmt (Primitive_Operations (Base_Type (T)));
7452 while Present (E) loop
7454 Write_Int (Int (Op));
7455 Write_Str (" === ");
7456 Write_Name (Chars (Op));
7458 Write_Name (Chars (Scope (Op)));