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 -- Deal with allocator restrictions
374 -- In accordance with H.4(7), the No_Allocators restriction only applies
375 -- to user-written allocators. The same consideration applies to the
376 -- No_Allocators_Before_Elaboration restriction.
378 if Comes_From_Source (N) then
379 Check_Restriction (No_Allocators, N);
381 -- Processing for No_Allocators_After_Elaboration, loop to look at
382 -- enclosing context, checking task case and main subprogram case.
386 while Present (P) loop
388 -- In both cases we need a handled sequence of statements, where
389 -- the occurrence of the allocator is within the statements.
391 if Nkind (P) = N_Handled_Sequence_Of_Statements
392 and then Is_List_Member (C)
393 and then List_Containing (C) = Statements (P)
395 -- Check for allocator within task body, this is a definite
396 -- violation of No_Allocators_After_Elaboration we can detect.
398 if Nkind (Original_Node (Parent (P))) = N_Task_Body then
399 Check_Restriction (No_Allocators_After_Elaboration, N);
403 -- The other case is appearance in a subprogram body. This may
404 -- be a violation if this is a library level subprogram, and it
405 -- turns out to be used as the main program, but only the
406 -- binder knows that, so just record the occurrence.
408 if Nkind (Original_Node (Parent (P))) = N_Subprogram_Body
409 and then Nkind (Parent (Parent (P))) = N_Compilation_Unit
411 Set_Has_Allocator (Current_Sem_Unit);
420 -- Analyze the allocator
422 if Nkind (E) = N_Qualified_Expression then
423 Acc_Type := Create_Itype (E_Allocator_Type, N);
424 Set_Etype (Acc_Type, Acc_Type);
425 Find_Type (Subtype_Mark (E));
427 -- Analyze the qualified expression, and apply the name resolution
428 -- rule given in 4.7 (3).
431 Type_Id := Etype (E);
432 Set_Directly_Designated_Type (Acc_Type, Type_Id);
434 Resolve (Expression (E), Type_Id);
436 if Is_Limited_Type (Type_Id)
437 and then Comes_From_Source (N)
438 and then not In_Instance_Body
440 if not OK_For_Limited_Init (Type_Id, Expression (E)) then
441 Error_Msg_N ("initialization not allowed for limited types", N);
442 Explain_Limited_Type (Type_Id, N);
446 -- A qualified expression requires an exact match of the type,
447 -- class-wide matching is not allowed.
449 -- if Is_Class_Wide_Type (Type_Id)
450 -- and then Base_Type
451 -- (Etype (Expression (E))) /= Base_Type (Type_Id)
453 -- Wrong_Type (Expression (E), Type_Id);
456 Check_Non_Static_Context (Expression (E));
458 -- We don't analyze the qualified expression itself because it's
459 -- part of the allocator
461 Set_Etype (E, Type_Id);
463 -- Case where allocator has a subtype indication
468 Base_Typ : Entity_Id;
471 -- If the allocator includes a N_Subtype_Indication then a
472 -- constraint is present, otherwise the node is a subtype mark.
473 -- Introduce an explicit subtype declaration into the tree
474 -- defining some anonymous subtype and rewrite the allocator to
475 -- use this subtype rather than the subtype indication.
477 -- It is important to introduce the explicit subtype declaration
478 -- so that the bounds of the subtype indication are attached to
479 -- the tree in case the allocator is inside a generic unit.
481 if Nkind (E) = N_Subtype_Indication then
483 -- A constraint is only allowed for a composite type in Ada
484 -- 95. In Ada 83, a constraint is also allowed for an
485 -- access-to-composite type, but the constraint is ignored.
487 Find_Type (Subtype_Mark (E));
488 Base_Typ := Entity (Subtype_Mark (E));
490 if Is_Elementary_Type (Base_Typ) then
491 if not (Ada_Version = Ada_83
492 and then Is_Access_Type (Base_Typ))
494 Error_Msg_N ("constraint not allowed here", E);
496 if Nkind (Constraint (E)) =
497 N_Index_Or_Discriminant_Constraint
499 Error_Msg_N -- CODEFIX
500 ("\if qualified expression was meant, " &
501 "use apostrophe", Constraint (E));
505 -- Get rid of the bogus constraint:
507 Rewrite (E, New_Copy_Tree (Subtype_Mark (E)));
508 Analyze_Allocator (N);
511 -- Ada 2005, AI-363: if the designated type has a constrained
512 -- partial view, it cannot receive a discriminant constraint,
513 -- and the allocated object is unconstrained.
515 elsif Ada_Version >= Ada_2005
516 and then Has_Constrained_Partial_View (Base_Typ)
519 ("constraint no allowed when type " &
520 "has a constrained partial view", Constraint (E));
523 if Expander_Active then
524 Def_Id := Make_Temporary (Loc, 'S');
527 Make_Subtype_Declaration (Loc,
528 Defining_Identifier => Def_Id,
529 Subtype_Indication => Relocate_Node (E)));
531 if Sav_Errs /= Serious_Errors_Detected
532 and then Nkind (Constraint (E)) =
533 N_Index_Or_Discriminant_Constraint
535 Error_Msg_N -- CODEFIX
536 ("if qualified expression was meant, " &
537 "use apostrophe!", Constraint (E));
540 E := New_Occurrence_Of (Def_Id, Loc);
541 Rewrite (Expression (N), E);
545 Type_Id := Process_Subtype (E, N);
546 Acc_Type := Create_Itype (E_Allocator_Type, N);
547 Set_Etype (Acc_Type, Acc_Type);
548 Set_Directly_Designated_Type (Acc_Type, Type_Id);
549 Check_Fully_Declared (Type_Id, N);
551 -- Ada 2005 (AI-231): If the designated type is itself an access
552 -- type that excludes null, its default initialization will
553 -- be a null object, and we can insert an unconditional raise
554 -- before the allocator.
556 -- Ada 2012 (AI-104): A not null indication here is altogether
559 if Can_Never_Be_Null (Type_Id) then
561 Not_Null_Check : constant Node_Id :=
562 Make_Raise_Constraint_Error (Sloc (E),
563 Reason => CE_Null_Not_Allowed);
566 if Ada_Version >= Ada_2012 then
568 ("an uninitialized allocator cannot have"
569 & " a null exclusion", N);
571 elsif Expander_Active then
572 Insert_Action (N, Not_Null_Check);
573 Analyze (Not_Null_Check);
576 Error_Msg_N ("null value not allowed here?", E);
581 -- Check restriction against dynamically allocated protected
582 -- objects. Note that when limited aggregates are supported,
583 -- a similar test should be applied to an allocator with a
584 -- qualified expression ???
586 if Is_Protected_Type (Type_Id) then
587 Check_Restriction (No_Protected_Type_Allocators, N);
590 -- Check for missing initialization. Skip this check if we already
591 -- had errors on analyzing the allocator, since in that case these
592 -- are probably cascaded errors.
594 if Is_Indefinite_Subtype (Type_Id)
595 and then Serious_Errors_Detected = Sav_Errs
597 if Is_Class_Wide_Type (Type_Id) then
599 ("initialization required in class-wide allocation", N);
601 if Ada_Version < Ada_2005
602 and then Is_Limited_Type (Type_Id)
604 Error_Msg_N ("unconstrained allocation not allowed", N);
606 if Is_Array_Type (Type_Id) then
608 ("\constraint with array bounds required", N);
610 elsif Has_Unknown_Discriminants (Type_Id) then
613 else pragma Assert (Has_Discriminants (Type_Id));
615 ("\constraint with discriminant values required", N);
618 -- Limited Ada 2005 and general non-limited case
622 ("uninitialized unconstrained allocation not allowed",
625 if Is_Array_Type (Type_Id) then
627 ("\qualified expression or constraint with " &
628 "array bounds required", N);
630 elsif Has_Unknown_Discriminants (Type_Id) then
631 Error_Msg_N ("\qualified expression required", N);
633 else pragma Assert (Has_Discriminants (Type_Id));
635 ("\qualified expression or constraint with " &
636 "discriminant values required", N);
644 if Is_Abstract_Type (Type_Id) then
645 Error_Msg_N ("cannot allocate abstract object", E);
648 if Has_Task (Designated_Type (Acc_Type)) then
649 Check_Restriction (No_Tasking, N);
650 Check_Restriction (Max_Tasks, N);
651 Check_Restriction (No_Task_Allocators, N);
653 -- Check that an allocator with task parts isn't for a nested access
654 -- type when restriction No_Task_Hierarchy applies.
656 if not Is_Library_Level_Entity (Acc_Type) then
657 Check_Restriction (No_Task_Hierarchy, N);
661 -- Check that an allocator of a nested access type doesn't create a
662 -- protected object when restriction No_Local_Protected_Objects applies.
663 -- We don't have an equivalent to Has_Task for protected types, so only
664 -- cases where the designated type itself is a protected type are
665 -- currently checked. ???
667 if Is_Protected_Type (Designated_Type (Acc_Type))
668 and then not Is_Library_Level_Entity (Acc_Type)
670 Check_Restriction (No_Local_Protected_Objects, N);
673 -- If the No_Streams restriction is set, check that the type of the
674 -- object is not, and does not contain, any subtype derived from
675 -- Ada.Streams.Root_Stream_Type. Note that we guard the call to
676 -- Has_Stream just for efficiency reasons. There is no point in
677 -- spending time on a Has_Stream check if the restriction is not set.
679 if Restriction_Check_Required (No_Streams) then
680 if Has_Stream (Designated_Type (Acc_Type)) then
681 Check_Restriction (No_Streams, N);
685 Set_Etype (N, Acc_Type);
687 if not Is_Library_Level_Entity (Acc_Type) then
688 Check_Restriction (No_Local_Allocators, N);
691 if Serious_Errors_Detected > Sav_Errs then
692 Set_Error_Posted (N);
693 Set_Etype (N, Any_Type);
695 end Analyze_Allocator;
697 ---------------------------
698 -- Analyze_Arithmetic_Op --
699 ---------------------------
701 procedure Analyze_Arithmetic_Op (N : Node_Id) is
702 L : constant Node_Id := Left_Opnd (N);
703 R : constant Node_Id := Right_Opnd (N);
707 Candidate_Type := Empty;
708 Analyze_Expression (L);
709 Analyze_Expression (R);
711 -- If the entity is already set, the node is the instantiation of a
712 -- generic node with a non-local reference, or was manufactured by a
713 -- call to Make_Op_xxx. In either case the entity is known to be valid,
714 -- and we do not need to collect interpretations, instead we just get
715 -- the single possible interpretation.
719 if Present (Op_Id) then
720 if Ekind (Op_Id) = E_Operator then
722 if Nkind_In (N, N_Op_Divide, N_Op_Mod, N_Op_Multiply, N_Op_Rem)
723 and then Treat_Fixed_As_Integer (N)
727 Set_Etype (N, Any_Type);
728 Find_Arithmetic_Types (L, R, Op_Id, N);
732 Set_Etype (N, Any_Type);
733 Add_One_Interp (N, Op_Id, Etype (Op_Id));
736 -- Entity is not already set, so we do need to collect interpretations
739 Op_Id := Get_Name_Entity_Id (Chars (N));
740 Set_Etype (N, Any_Type);
742 while Present (Op_Id) loop
743 if Ekind (Op_Id) = E_Operator
744 and then Present (Next_Entity (First_Entity (Op_Id)))
746 Find_Arithmetic_Types (L, R, Op_Id, N);
748 -- The following may seem superfluous, because an operator cannot
749 -- be generic, but this ignores the cleverness of the author of
752 elsif Is_Overloadable (Op_Id) then
753 Analyze_User_Defined_Binary_Op (N, Op_Id);
756 Op_Id := Homonym (Op_Id);
761 end Analyze_Arithmetic_Op;
767 -- Function, procedure, and entry calls are checked here. The Name in
768 -- the call may be overloaded. The actuals have been analyzed and may
769 -- themselves be overloaded. On exit from this procedure, the node N
770 -- may have zero, one or more interpretations. In the first case an
771 -- error message is produced. In the last case, the node is flagged
772 -- as overloaded and the interpretations are collected in All_Interp.
774 -- If the name is an Access_To_Subprogram, it cannot be overloaded, but
775 -- the type-checking is similar to that of other calls.
777 procedure Analyze_Call (N : Node_Id) is
778 Actuals : constant List_Id := Parameter_Associations (N);
783 Success : Boolean := False;
785 Deref : Boolean := False;
786 -- Flag indicates whether an interpretation of the prefix is a
787 -- parameterless call that returns an access_to_subprogram.
789 function Name_Denotes_Function return Boolean;
790 -- If the type of the name is an access to subprogram, this may be the
791 -- type of a name, or the return type of the function being called. If
792 -- the name is not an entity then it can denote a protected function.
793 -- Until we distinguish Etype from Return_Type, we must use this routine
794 -- to resolve the meaning of the name in the call.
796 procedure No_Interpretation;
797 -- Output error message when no valid interpretation exists
799 ---------------------------
800 -- Name_Denotes_Function --
801 ---------------------------
803 function Name_Denotes_Function return Boolean is
805 if Is_Entity_Name (Nam) then
806 return Ekind (Entity (Nam)) = E_Function;
808 elsif Nkind (Nam) = N_Selected_Component then
809 return Ekind (Entity (Selector_Name (Nam))) = E_Function;
814 end Name_Denotes_Function;
816 -----------------------
817 -- No_Interpretation --
818 -----------------------
820 procedure No_Interpretation is
821 L : constant Boolean := Is_List_Member (N);
822 K : constant Node_Kind := Nkind (Parent (N));
825 -- If the node is in a list whose parent is not an expression then it
826 -- must be an attempted procedure call.
828 if L and then K not in N_Subexpr then
829 if Ekind (Entity (Nam)) = E_Generic_Procedure then
831 ("must instantiate generic procedure& before call",
835 ("procedure or entry name expected", Nam);
838 -- Check for tasking cases where only an entry call will do
841 and then Nkind_In (K, N_Entry_Call_Alternative,
842 N_Triggering_Alternative)
844 Error_Msg_N ("entry name expected", Nam);
846 -- Otherwise give general error message
849 Error_Msg_N ("invalid prefix in call", Nam);
851 end No_Interpretation;
853 -- Start of processing for Analyze_Call
856 -- Initialize the type of the result of the call to the error type,
857 -- which will be reset if the type is successfully resolved.
859 Set_Etype (N, Any_Type);
863 if not Is_Overloaded (Nam) then
865 -- Only one interpretation to check
867 if Ekind (Etype (Nam)) = E_Subprogram_Type then
868 Nam_Ent := Etype (Nam);
870 -- If the prefix is an access_to_subprogram, this may be an indirect
871 -- call. This is the case if the name in the call is not an entity
872 -- name, or if it is a function name in the context of a procedure
873 -- call. In this latter case, we have a call to a parameterless
874 -- function that returns a pointer_to_procedure which is the entity
875 -- being called. Finally, F (X) may be a call to a parameterless
876 -- function that returns a pointer to a function with parameters.
878 elsif Is_Access_Type (Etype (Nam))
879 and then Ekind (Designated_Type (Etype (Nam))) = E_Subprogram_Type
881 (not Name_Denotes_Function
882 or else Nkind (N) = N_Procedure_Call_Statement
884 (Nkind (Parent (N)) /= N_Explicit_Dereference
885 and then Is_Entity_Name (Nam)
886 and then No (First_Formal (Entity (Nam)))
887 and then Present (Actuals)))
889 Nam_Ent := Designated_Type (Etype (Nam));
890 Insert_Explicit_Dereference (Nam);
892 -- Selected component case. Simple entry or protected operation,
893 -- where the entry name is given by the selector name.
895 elsif Nkind (Nam) = N_Selected_Component then
896 Nam_Ent := Entity (Selector_Name (Nam));
898 if not Ekind_In (Nam_Ent, E_Entry,
903 Error_Msg_N ("name in call is not a callable entity", Nam);
904 Set_Etype (N, Any_Type);
908 -- If the name is an Indexed component, it can be a call to a member
909 -- of an entry family. The prefix must be a selected component whose
910 -- selector is the entry. Analyze_Procedure_Call normalizes several
911 -- kinds of call into this form.
913 elsif Nkind (Nam) = N_Indexed_Component then
914 if Nkind (Prefix (Nam)) = N_Selected_Component then
915 Nam_Ent := Entity (Selector_Name (Prefix (Nam)));
917 Error_Msg_N ("name in call is not a callable entity", Nam);
918 Set_Etype (N, Any_Type);
922 elsif not Is_Entity_Name (Nam) then
923 Error_Msg_N ("name in call is not a callable entity", Nam);
924 Set_Etype (N, Any_Type);
928 Nam_Ent := Entity (Nam);
930 -- If no interpretations, give error message
932 if not Is_Overloadable (Nam_Ent) then
938 -- Operations generated for RACW stub types are called only through
939 -- dispatching, and can never be the static interpretation of a call.
941 if Is_RACW_Stub_Type_Operation (Nam_Ent) then
946 Analyze_One_Call (N, Nam_Ent, True, Success);
948 -- If this is an indirect call, the return type of the access_to
949 -- subprogram may be an incomplete type. At the point of the call,
950 -- use the full type if available, and at the same time update the
951 -- return type of the access_to_subprogram.
954 and then Nkind (Nam) = N_Explicit_Dereference
955 and then Ekind (Etype (N)) = E_Incomplete_Type
956 and then Present (Full_View (Etype (N)))
958 Set_Etype (N, Full_View (Etype (N)));
959 Set_Etype (Nam_Ent, Etype (N));
963 -- An overloaded selected component must denote overloaded operations
964 -- of a concurrent type. The interpretations are attached to the
965 -- simple name of those operations.
967 if Nkind (Nam) = N_Selected_Component then
968 Nam := Selector_Name (Nam);
971 Get_First_Interp (Nam, X, It);
973 while Present (It.Nam) loop
977 -- Name may be call that returns an access to subprogram, or more
978 -- generally an overloaded expression one of whose interpretations
979 -- yields an access to subprogram. If the name is an entity, we do
980 -- not dereference, because the node is a call that returns the
981 -- access type: note difference between f(x), where the call may
982 -- return an access subprogram type, and f(x)(y), where the type
983 -- returned by the call to f is implicitly dereferenced to analyze
986 if Is_Access_Type (Nam_Ent) then
987 Nam_Ent := Designated_Type (Nam_Ent);
989 elsif Is_Access_Type (Etype (Nam_Ent))
991 (not Is_Entity_Name (Nam)
992 or else Nkind (N) = N_Procedure_Call_Statement)
993 and then Ekind (Designated_Type (Etype (Nam_Ent)))
996 Nam_Ent := Designated_Type (Etype (Nam_Ent));
998 if Is_Entity_Name (Nam) then
1003 -- If the call has been rewritten from a prefixed call, the first
1004 -- parameter has been analyzed, but may need a subsequent
1005 -- dereference, so skip its analysis now.
1007 if N /= Original_Node (N)
1008 and then Nkind (Original_Node (N)) = Nkind (N)
1009 and then Nkind (Name (N)) /= Nkind (Name (Original_Node (N)))
1010 and then Present (Parameter_Associations (N))
1011 and then Present (Etype (First (Parameter_Associations (N))))
1014 (N, Nam_Ent, False, Success, Skip_First => True);
1016 Analyze_One_Call (N, Nam_Ent, False, Success);
1019 -- If the interpretation succeeds, mark the proper type of the
1020 -- prefix (any valid candidate will do). If not, remove the
1021 -- candidate interpretation. This only needs to be done for
1022 -- overloaded protected operations, for other entities disambi-
1023 -- guation is done directly in Resolve.
1027 and then Nkind (Parent (N)) /= N_Explicit_Dereference
1029 Set_Entity (Nam, It.Nam);
1030 Insert_Explicit_Dereference (Nam);
1031 Set_Etype (Nam, Nam_Ent);
1034 Set_Etype (Nam, It.Typ);
1037 elsif Nkind_In (Name (N), N_Selected_Component,
1043 Get_Next_Interp (X, It);
1046 -- If the name is the result of a function call, it can only
1047 -- be a call to a function returning an access to subprogram.
1048 -- Insert explicit dereference.
1050 if Nkind (Nam) = N_Function_Call then
1051 Insert_Explicit_Dereference (Nam);
1054 if Etype (N) = Any_Type then
1056 -- None of the interpretations is compatible with the actuals
1058 Diagnose_Call (N, Nam);
1060 -- Special checks for uninstantiated put routines
1062 if Nkind (N) = N_Procedure_Call_Statement
1063 and then Is_Entity_Name (Nam)
1064 and then Chars (Nam) = Name_Put
1065 and then List_Length (Actuals) = 1
1068 Arg : constant Node_Id := First (Actuals);
1072 if Nkind (Arg) = N_Parameter_Association then
1073 Typ := Etype (Explicit_Actual_Parameter (Arg));
1078 if Is_Signed_Integer_Type (Typ) then
1080 ("possible missing instantiation of " &
1081 "'Text_'I'O.'Integer_'I'O!", Nam);
1083 elsif Is_Modular_Integer_Type (Typ) then
1085 ("possible missing instantiation of " &
1086 "'Text_'I'O.'Modular_'I'O!", Nam);
1088 elsif Is_Floating_Point_Type (Typ) then
1090 ("possible missing instantiation of " &
1091 "'Text_'I'O.'Float_'I'O!", Nam);
1093 elsif Is_Ordinary_Fixed_Point_Type (Typ) then
1095 ("possible missing instantiation of " &
1096 "'Text_'I'O.'Fixed_'I'O!", Nam);
1098 elsif Is_Decimal_Fixed_Point_Type (Typ) then
1100 ("possible missing instantiation of " &
1101 "'Text_'I'O.'Decimal_'I'O!", Nam);
1103 elsif Is_Enumeration_Type (Typ) then
1105 ("possible missing instantiation of " &
1106 "'Text_'I'O.'Enumeration_'I'O!", Nam);
1111 elsif not Is_Overloaded (N)
1112 and then Is_Entity_Name (Nam)
1114 -- Resolution yields a single interpretation. Verify that the
1115 -- reference has capitalization consistent with the declaration.
1117 Set_Entity_With_Style_Check (Nam, Entity (Nam));
1118 Generate_Reference (Entity (Nam), Nam);
1120 Set_Etype (Nam, Etype (Entity (Nam)));
1122 Remove_Abstract_Operations (N);
1129 -----------------------------
1130 -- Analyze_Case_Expression --
1131 -----------------------------
1133 procedure Analyze_Case_Expression (N : Node_Id) is
1134 Expr : constant Node_Id := Expression (N);
1135 FirstX : constant Node_Id := Expression (First (Alternatives (N)));
1137 Exp_Type : Entity_Id;
1138 Exp_Btype : Entity_Id;
1140 Dont_Care : Boolean;
1141 Others_Present : Boolean;
1143 procedure Non_Static_Choice_Error (Choice : Node_Id);
1144 -- Error routine invoked by the generic instantiation below when
1145 -- the case expression has a non static choice.
1147 package Case_Choices_Processing is new
1148 Generic_Choices_Processing
1149 (Get_Alternatives => Alternatives,
1150 Get_Choices => Discrete_Choices,
1151 Process_Empty_Choice => No_OP,
1152 Process_Non_Static_Choice => Non_Static_Choice_Error,
1153 Process_Associated_Node => No_OP);
1154 use Case_Choices_Processing;
1156 -----------------------------
1157 -- Non_Static_Choice_Error --
1158 -----------------------------
1160 procedure Non_Static_Choice_Error (Choice : Node_Id) is
1162 Flag_Non_Static_Expr
1163 ("choice given in case expression is not static!", Choice);
1164 end Non_Static_Choice_Error;
1166 -- Start of processing for Analyze_Case_Expression
1169 if Comes_From_Source (N) then
1170 Check_Compiler_Unit (N);
1173 Analyze_And_Resolve (Expr, Any_Discrete);
1174 Check_Unset_Reference (Expr);
1175 Exp_Type := Etype (Expr);
1176 Exp_Btype := Base_Type (Exp_Type);
1178 Alt := First (Alternatives (N));
1179 while Present (Alt) loop
1180 Analyze (Expression (Alt));
1184 if not Is_Overloaded (FirstX) then
1185 Set_Etype (N, Etype (FirstX));
1193 Set_Etype (N, Any_Type);
1195 Get_First_Interp (FirstX, I, It);
1196 while Present (It.Nam) loop
1198 -- For each interpretation of the first expression, we only
1199 -- add the interpretation if every other expression in the
1200 -- case expression alternatives has a compatible type.
1202 Alt := Next (First (Alternatives (N)));
1203 while Present (Alt) loop
1204 exit when not Has_Compatible_Type (Expression (Alt), It.Typ);
1209 Add_One_Interp (N, It.Typ, It.Typ);
1212 Get_Next_Interp (I, It);
1217 Exp_Btype := Base_Type (Exp_Type);
1219 -- The expression must be of a discrete type which must be determinable
1220 -- independently of the context in which the expression occurs, but
1221 -- using the fact that the expression must be of a discrete type.
1222 -- Moreover, the type this expression must not be a character literal
1223 -- (which is always ambiguous).
1225 -- If error already reported by Resolve, nothing more to do
1227 if Exp_Btype = Any_Discrete
1228 or else Exp_Btype = Any_Type
1232 elsif Exp_Btype = Any_Character then
1234 ("character literal as case expression is ambiguous", Expr);
1238 -- If the case expression is a formal object of mode in out, then
1239 -- treat it as having a nonstatic subtype by forcing use of the base
1240 -- type (which has to get passed to Check_Case_Choices below). Also
1241 -- use base type when the case expression is parenthesized.
1243 if Paren_Count (Expr) > 0
1244 or else (Is_Entity_Name (Expr)
1245 and then Ekind (Entity (Expr)) = E_Generic_In_Out_Parameter)
1247 Exp_Type := Exp_Btype;
1250 -- Call instantiated Analyze_Choices which does the rest of the work
1252 Analyze_Choices (N, Exp_Type, Dont_Care, Others_Present);
1254 if Exp_Type = Universal_Integer and then not Others_Present then
1256 ("case on universal integer requires OTHERS choice", Expr);
1258 end Analyze_Case_Expression;
1260 ---------------------------
1261 -- Analyze_Comparison_Op --
1262 ---------------------------
1264 procedure Analyze_Comparison_Op (N : Node_Id) is
1265 L : constant Node_Id := Left_Opnd (N);
1266 R : constant Node_Id := Right_Opnd (N);
1267 Op_Id : Entity_Id := Entity (N);
1270 Set_Etype (N, Any_Type);
1271 Candidate_Type := Empty;
1273 Analyze_Expression (L);
1274 Analyze_Expression (R);
1276 if Present (Op_Id) then
1277 if Ekind (Op_Id) = E_Operator then
1278 Find_Comparison_Types (L, R, Op_Id, N);
1280 Add_One_Interp (N, Op_Id, Etype (Op_Id));
1283 if Is_Overloaded (L) then
1284 Set_Etype (L, Intersect_Types (L, R));
1288 Op_Id := Get_Name_Entity_Id (Chars (N));
1289 while Present (Op_Id) loop
1290 if Ekind (Op_Id) = E_Operator then
1291 Find_Comparison_Types (L, R, Op_Id, N);
1293 Analyze_User_Defined_Binary_Op (N, Op_Id);
1296 Op_Id := Homonym (Op_Id);
1301 end Analyze_Comparison_Op;
1303 ---------------------------
1304 -- Analyze_Concatenation --
1305 ---------------------------
1307 procedure Analyze_Concatenation (N : Node_Id) is
1309 -- We wish to avoid deep recursion, because concatenations are often
1310 -- deeply nested, as in A&B&...&Z. Therefore, we walk down the left
1311 -- operands nonrecursively until we find something that is not a
1312 -- concatenation (A in this case), or has already been analyzed. We
1313 -- analyze that, and then walk back up the tree following Parent
1314 -- pointers, calling Analyze_Concatenation_Rest to do the rest of the
1315 -- work at each level. The Parent pointers allow us to avoid recursion,
1316 -- and thus avoid running out of memory.
1322 Candidate_Type := Empty;
1324 -- The following code is equivalent to:
1326 -- Set_Etype (N, Any_Type);
1327 -- Analyze_Expression (Left_Opnd (N));
1328 -- Analyze_Concatenation_Rest (N);
1330 -- where the Analyze_Expression call recurses back here if the left
1331 -- operand is a concatenation.
1333 -- Walk down left operands
1336 Set_Etype (NN, Any_Type);
1337 L := Left_Opnd (NN);
1338 exit when Nkind (L) /= N_Op_Concat or else Analyzed (L);
1342 -- Now (given the above example) NN is A&B and L is A
1344 -- First analyze L ...
1346 Analyze_Expression (L);
1348 -- ... then walk NN back up until we reach N (where we started), calling
1349 -- Analyze_Concatenation_Rest along the way.
1352 Analyze_Concatenation_Rest (NN);
1356 end Analyze_Concatenation;
1358 --------------------------------
1359 -- Analyze_Concatenation_Rest --
1360 --------------------------------
1362 -- If the only one-dimensional array type in scope is String,
1363 -- this is the resulting type of the operation. Otherwise there
1364 -- will be a concatenation operation defined for each user-defined
1365 -- one-dimensional array.
1367 procedure Analyze_Concatenation_Rest (N : Node_Id) is
1368 L : constant Node_Id := Left_Opnd (N);
1369 R : constant Node_Id := Right_Opnd (N);
1370 Op_Id : Entity_Id := Entity (N);
1375 Analyze_Expression (R);
1377 -- If the entity is present, the node appears in an instance, and
1378 -- denotes a predefined concatenation operation. The resulting type is
1379 -- obtained from the arguments when possible. If the arguments are
1380 -- aggregates, the array type and the concatenation type must be
1383 if Present (Op_Id) then
1384 if Ekind (Op_Id) = E_Operator then
1385 LT := Base_Type (Etype (L));
1386 RT := Base_Type (Etype (R));
1388 if Is_Array_Type (LT)
1389 and then (RT = LT or else RT = Base_Type (Component_Type (LT)))
1391 Add_One_Interp (N, Op_Id, LT);
1393 elsif Is_Array_Type (RT)
1394 and then LT = Base_Type (Component_Type (RT))
1396 Add_One_Interp (N, Op_Id, RT);
1398 -- If one operand is a string type or a user-defined array type,
1399 -- and the other is a literal, result is of the specific type.
1402 (Root_Type (LT) = Standard_String
1403 or else Scope (LT) /= Standard_Standard)
1404 and then Etype (R) = Any_String
1406 Add_One_Interp (N, Op_Id, LT);
1409 (Root_Type (RT) = Standard_String
1410 or else Scope (RT) /= Standard_Standard)
1411 and then Etype (L) = Any_String
1413 Add_One_Interp (N, Op_Id, RT);
1415 elsif not Is_Generic_Type (Etype (Op_Id)) then
1416 Add_One_Interp (N, Op_Id, Etype (Op_Id));
1419 -- Type and its operations must be visible
1421 Set_Entity (N, Empty);
1422 Analyze_Concatenation (N);
1426 Add_One_Interp (N, Op_Id, Etype (Op_Id));
1430 Op_Id := Get_Name_Entity_Id (Name_Op_Concat);
1431 while Present (Op_Id) loop
1432 if Ekind (Op_Id) = E_Operator then
1434 -- Do not consider operators declared in dead code, they can
1435 -- not be part of the resolution.
1437 if Is_Eliminated (Op_Id) then
1440 Find_Concatenation_Types (L, R, Op_Id, N);
1444 Analyze_User_Defined_Binary_Op (N, Op_Id);
1447 Op_Id := Homonym (Op_Id);
1452 end Analyze_Concatenation_Rest;
1454 ------------------------------------
1455 -- Analyze_Conditional_Expression --
1456 ------------------------------------
1458 procedure Analyze_Conditional_Expression (N : Node_Id) is
1459 Condition : constant Node_Id := First (Expressions (N));
1460 Then_Expr : constant Node_Id := Next (Condition);
1461 Else_Expr : Node_Id;
1464 -- Defend against error of missing expressions from previous error
1466 if No (Then_Expr) then
1470 Else_Expr := Next (Then_Expr);
1472 if Comes_From_Source (N) then
1473 Check_Compiler_Unit (N);
1476 Analyze_Expression (Condition);
1477 Analyze_Expression (Then_Expr);
1479 if Present (Else_Expr) then
1480 Analyze_Expression (Else_Expr);
1483 -- If then expression not overloaded, then that decides the type
1485 if not Is_Overloaded (Then_Expr) then
1486 Set_Etype (N, Etype (Then_Expr));
1488 -- Case where then expression is overloaded
1496 Set_Etype (N, Any_Type);
1497 Get_First_Interp (Then_Expr, I, It);
1498 if No (Else_Expr) then
1499 -- if no else_expression the conditional must be boolean.
1501 Set_Etype (N, Standard_Boolean);
1503 while Present (It.Nam) loop
1505 -- For each possible intepretation of the Then Expression,
1506 -- add it only if the else expression has a compatible type.
1508 if Has_Compatible_Type (Else_Expr, It.Typ) then
1509 Add_One_Interp (N, It.Typ, It.Typ);
1512 Get_Next_Interp (I, It);
1517 end Analyze_Conditional_Expression;
1519 -------------------------
1520 -- Analyze_Equality_Op --
1521 -------------------------
1523 procedure Analyze_Equality_Op (N : Node_Id) is
1524 Loc : constant Source_Ptr := Sloc (N);
1525 L : constant Node_Id := Left_Opnd (N);
1526 R : constant Node_Id := Right_Opnd (N);
1530 Set_Etype (N, Any_Type);
1531 Candidate_Type := Empty;
1533 Analyze_Expression (L);
1534 Analyze_Expression (R);
1536 -- If the entity is set, the node is a generic instance with a non-local
1537 -- reference to the predefined operator or to a user-defined function.
1538 -- It can also be an inequality that is expanded into the negation of a
1539 -- call to a user-defined equality operator.
1541 -- For the predefined case, the result is Boolean, regardless of the
1542 -- type of the operands. The operands may even be limited, if they are
1543 -- generic actuals. If they are overloaded, label the left argument with
1544 -- the common type that must be present, or with the type of the formal
1545 -- of the user-defined function.
1547 if Present (Entity (N)) then
1548 Op_Id := Entity (N);
1550 if Ekind (Op_Id) = E_Operator then
1551 Add_One_Interp (N, Op_Id, Standard_Boolean);
1553 Add_One_Interp (N, Op_Id, Etype (Op_Id));
1556 if Is_Overloaded (L) then
1557 if Ekind (Op_Id) = E_Operator then
1558 Set_Etype (L, Intersect_Types (L, R));
1560 Set_Etype (L, Etype (First_Formal (Op_Id)));
1565 Op_Id := Get_Name_Entity_Id (Chars (N));
1566 while Present (Op_Id) loop
1567 if Ekind (Op_Id) = E_Operator then
1568 Find_Equality_Types (L, R, Op_Id, N);
1570 Analyze_User_Defined_Binary_Op (N, Op_Id);
1573 Op_Id := Homonym (Op_Id);
1577 -- If there was no match, and the operator is inequality, this may
1578 -- be a case where inequality has not been made explicit, as for
1579 -- tagged types. Analyze the node as the negation of an equality
1580 -- operation. This cannot be done earlier, because before analysis
1581 -- we cannot rule out the presence of an explicit inequality.
1583 if Etype (N) = Any_Type
1584 and then Nkind (N) = N_Op_Ne
1586 Op_Id := Get_Name_Entity_Id (Name_Op_Eq);
1587 while Present (Op_Id) loop
1588 if Ekind (Op_Id) = E_Operator then
1589 Find_Equality_Types (L, R, Op_Id, N);
1591 Analyze_User_Defined_Binary_Op (N, Op_Id);
1594 Op_Id := Homonym (Op_Id);
1597 if Etype (N) /= Any_Type then
1598 Op_Id := Entity (N);
1604 Left_Opnd => Left_Opnd (N),
1605 Right_Opnd => Right_Opnd (N))));
1607 Set_Entity (Right_Opnd (N), Op_Id);
1613 end Analyze_Equality_Op;
1615 ----------------------------------
1616 -- Analyze_Explicit_Dereference --
1617 ----------------------------------
1619 procedure Analyze_Explicit_Dereference (N : Node_Id) is
1620 Loc : constant Source_Ptr := Sloc (N);
1621 P : constant Node_Id := Prefix (N);
1627 function Is_Function_Type return Boolean;
1628 -- Check whether node may be interpreted as an implicit function call
1630 ----------------------
1631 -- Is_Function_Type --
1632 ----------------------
1634 function Is_Function_Type return Boolean is
1639 if not Is_Overloaded (N) then
1640 return Ekind (Base_Type (Etype (N))) = E_Subprogram_Type
1641 and then Etype (Base_Type (Etype (N))) /= Standard_Void_Type;
1644 Get_First_Interp (N, I, It);
1645 while Present (It.Nam) loop
1646 if Ekind (Base_Type (It.Typ)) /= E_Subprogram_Type
1647 or else Etype (Base_Type (It.Typ)) = Standard_Void_Type
1652 Get_Next_Interp (I, It);
1657 end Is_Function_Type;
1659 -- Start of processing for Analyze_Explicit_Dereference
1663 Set_Etype (N, Any_Type);
1665 -- Test for remote access to subprogram type, and if so return
1666 -- after rewriting the original tree.
1668 if Remote_AST_E_Dereference (P) then
1672 -- Normal processing for other than remote access to subprogram type
1674 if not Is_Overloaded (P) then
1675 if Is_Access_Type (Etype (P)) then
1677 -- Set the Etype. We need to go through Is_For_Access_Subtypes to
1678 -- avoid other problems caused by the Private_Subtype and it is
1679 -- safe to go to the Base_Type because this is the same as
1680 -- converting the access value to its Base_Type.
1683 DT : Entity_Id := Designated_Type (Etype (P));
1686 if Ekind (DT) = E_Private_Subtype
1687 and then Is_For_Access_Subtype (DT)
1689 DT := Base_Type (DT);
1692 -- An explicit dereference is a legal occurrence of an
1693 -- incomplete type imported through a limited_with clause,
1694 -- if the full view is visible.
1696 if From_With_Type (DT)
1697 and then not From_With_Type (Scope (DT))
1699 (Is_Immediately_Visible (Scope (DT))
1701 (Is_Child_Unit (Scope (DT))
1702 and then Is_Visible_Child_Unit (Scope (DT))))
1704 Set_Etype (N, Available_View (DT));
1711 elsif Etype (P) /= Any_Type then
1712 Error_Msg_N ("prefix of dereference must be an access type", N);
1717 Get_First_Interp (P, I, It);
1718 while Present (It.Nam) loop
1721 if Is_Access_Type (T) then
1722 Add_One_Interp (N, Designated_Type (T), Designated_Type (T));
1725 Get_Next_Interp (I, It);
1728 -- Error if no interpretation of the prefix has an access type
1730 if Etype (N) = Any_Type then
1732 ("access type required in prefix of explicit dereference", P);
1733 Set_Etype (N, Any_Type);
1739 and then Nkind (Parent (N)) /= N_Indexed_Component
1741 and then (Nkind (Parent (N)) /= N_Function_Call
1742 or else N /= Name (Parent (N)))
1744 and then (Nkind (Parent (N)) /= N_Procedure_Call_Statement
1745 or else N /= Name (Parent (N)))
1747 and then Nkind (Parent (N)) /= N_Subprogram_Renaming_Declaration
1748 and then (Nkind (Parent (N)) /= N_Attribute_Reference
1750 (Attribute_Name (Parent (N)) /= Name_Address
1752 Attribute_Name (Parent (N)) /= Name_Access))
1754 -- Name is a function call with no actuals, in a context that
1755 -- requires deproceduring (including as an actual in an enclosing
1756 -- function or procedure call). There are some pathological cases
1757 -- where the prefix might include functions that return access to
1758 -- subprograms and others that return a regular type. Disambiguation
1759 -- of those has to take place in Resolve.
1762 Make_Function_Call (Loc,
1763 Name => Make_Explicit_Dereference (Loc, P),
1764 Parameter_Associations => New_List);
1766 -- If the prefix is overloaded, remove operations that have formals,
1767 -- we know that this is a parameterless call.
1769 if Is_Overloaded (P) then
1770 Get_First_Interp (P, I, It);
1771 while Present (It.Nam) loop
1774 if No (First_Formal (Base_Type (Designated_Type (T)))) then
1780 Get_Next_Interp (I, It);
1787 elsif not Is_Function_Type
1788 and then Is_Overloaded (N)
1790 -- The prefix may include access to subprograms and other access
1791 -- types. If the context selects the interpretation that is a
1792 -- function call (not a procedure call) we cannot rewrite the node
1793 -- yet, but we include the result of the call interpretation.
1795 Get_First_Interp (N, I, It);
1796 while Present (It.Nam) loop
1797 if Ekind (Base_Type (It.Typ)) = E_Subprogram_Type
1798 and then Etype (Base_Type (It.Typ)) /= Standard_Void_Type
1799 and then Nkind (Parent (N)) /= N_Procedure_Call_Statement
1801 Add_One_Interp (N, Etype (It.Typ), Etype (It.Typ));
1804 Get_Next_Interp (I, It);
1808 -- A value of remote access-to-class-wide must not be dereferenced
1811 Validate_Remote_Access_To_Class_Wide_Type (N);
1812 end Analyze_Explicit_Dereference;
1814 ------------------------
1815 -- Analyze_Expression --
1816 ------------------------
1818 procedure Analyze_Expression (N : Node_Id) is
1821 Check_Parameterless_Call (N);
1822 end Analyze_Expression;
1824 -------------------------------------
1825 -- Analyze_Expression_With_Actions --
1826 -------------------------------------
1828 procedure Analyze_Expression_With_Actions (N : Node_Id) is
1832 A := First (Actions (N));
1839 Analyze_Expression (Expression (N));
1840 Set_Etype (N, Etype (Expression (N)));
1841 end Analyze_Expression_With_Actions;
1843 ------------------------------------
1844 -- Analyze_Indexed_Component_Form --
1845 ------------------------------------
1847 procedure Analyze_Indexed_Component_Form (N : Node_Id) is
1848 P : constant Node_Id := Prefix (N);
1849 Exprs : constant List_Id := Expressions (N);
1855 procedure Process_Function_Call;
1856 -- Prefix in indexed component form is an overloadable entity,
1857 -- so the node is a function call. Reformat it as such.
1859 procedure Process_Indexed_Component;
1860 -- Prefix in indexed component form is actually an indexed component.
1861 -- This routine processes it, knowing that the prefix is already
1864 procedure Process_Indexed_Component_Or_Slice;
1865 -- An indexed component with a single index may designate a slice if
1866 -- the index is a subtype mark. This routine disambiguates these two
1867 -- cases by resolving the prefix to see if it is a subtype mark.
1869 procedure Process_Overloaded_Indexed_Component;
1870 -- If the prefix of an indexed component is overloaded, the proper
1871 -- interpretation is selected by the index types and the context.
1873 ---------------------------
1874 -- Process_Function_Call --
1875 ---------------------------
1877 procedure Process_Function_Call is
1881 Change_Node (N, N_Function_Call);
1883 Set_Parameter_Associations (N, Exprs);
1885 -- Analyze actuals prior to analyzing the call itself
1887 Actual := First (Parameter_Associations (N));
1888 while Present (Actual) loop
1890 Check_Parameterless_Call (Actual);
1892 -- Move to next actual. Note that we use Next, not Next_Actual
1893 -- here. The reason for this is a bit subtle. If a function call
1894 -- includes named associations, the parser recognizes the node as
1895 -- a call, and it is analyzed as such. If all associations are
1896 -- positional, the parser builds an indexed_component node, and
1897 -- it is only after analysis of the prefix that the construct
1898 -- is recognized as a call, in which case Process_Function_Call
1899 -- rewrites the node and analyzes the actuals. If the list of
1900 -- actuals is malformed, the parser may leave the node as an
1901 -- indexed component (despite the presence of named associations).
1902 -- The iterator Next_Actual is equivalent to Next if the list is
1903 -- positional, but follows the normalized chain of actuals when
1904 -- named associations are present. In this case normalization has
1905 -- not taken place, and actuals remain unanalyzed, which leads to
1906 -- subsequent crashes or loops if there is an attempt to continue
1907 -- analysis of the program.
1913 end Process_Function_Call;
1915 -------------------------------
1916 -- Process_Indexed_Component --
1917 -------------------------------
1919 procedure Process_Indexed_Component is
1921 Array_Type : Entity_Id;
1923 Pent : Entity_Id := Empty;
1926 Exp := First (Exprs);
1928 if Is_Overloaded (P) then
1929 Process_Overloaded_Indexed_Component;
1932 Array_Type := Etype (P);
1934 if Is_Entity_Name (P) then
1936 elsif Nkind (P) = N_Selected_Component
1937 and then Is_Entity_Name (Selector_Name (P))
1939 Pent := Entity (Selector_Name (P));
1942 -- Prefix must be appropriate for an array type, taking into
1943 -- account a possible implicit dereference.
1945 if Is_Access_Type (Array_Type) then
1946 Error_Msg_NW (Warn_On_Dereference, "?implicit dereference", N);
1947 Array_Type := Process_Implicit_Dereference_Prefix (Pent, P);
1950 if Is_Array_Type (Array_Type) then
1953 elsif Present (Pent) and then Ekind (Pent) = E_Entry_Family then
1955 Set_Etype (N, Any_Type);
1957 if not Has_Compatible_Type
1958 (Exp, Entry_Index_Type (Pent))
1960 Error_Msg_N ("invalid index type in entry name", N);
1962 elsif Present (Next (Exp)) then
1963 Error_Msg_N ("too many subscripts in entry reference", N);
1966 Set_Etype (N, Etype (P));
1971 elsif Is_Record_Type (Array_Type)
1972 and then Remote_AST_I_Dereference (P)
1976 elsif Array_Type = Any_Type then
1977 Set_Etype (N, Any_Type);
1979 -- In most cases the analysis of the prefix will have emitted
1980 -- an error already, but if the prefix may be interpreted as a
1981 -- call in prefixed notation, the report is left to the caller.
1982 -- To prevent cascaded errors, report only if no previous ones.
1984 if Serious_Errors_Detected = 0 then
1985 Error_Msg_N ("invalid prefix in indexed component", P);
1987 if Nkind (P) = N_Expanded_Name then
1988 Error_Msg_NE ("\& is not visible", P, Selector_Name (P));
1994 -- Here we definitely have a bad indexing
1997 if Nkind (Parent (N)) = N_Requeue_Statement
1998 and then Present (Pent) and then Ekind (Pent) = E_Entry
2001 ("REQUEUE does not permit parameters", First (Exprs));
2003 elsif Is_Entity_Name (P)
2004 and then Etype (P) = Standard_Void_Type
2006 Error_Msg_NE ("incorrect use of&", P, Entity (P));
2009 Error_Msg_N ("array type required in indexed component", P);
2012 Set_Etype (N, Any_Type);
2016 Index := First_Index (Array_Type);
2017 while Present (Index) and then Present (Exp) loop
2018 if not Has_Compatible_Type (Exp, Etype (Index)) then
2019 Wrong_Type (Exp, Etype (Index));
2020 Set_Etype (N, Any_Type);
2028 Set_Etype (N, Component_Type (Array_Type));
2030 if Present (Index) then
2032 ("too few subscripts in array reference", First (Exprs));
2034 elsif Present (Exp) then
2035 Error_Msg_N ("too many subscripts in array reference", Exp);
2038 end Process_Indexed_Component;
2040 ----------------------------------------
2041 -- Process_Indexed_Component_Or_Slice --
2042 ----------------------------------------
2044 procedure Process_Indexed_Component_Or_Slice is
2046 Exp := First (Exprs);
2047 while Present (Exp) loop
2048 Analyze_Expression (Exp);
2052 Exp := First (Exprs);
2054 -- If one index is present, and it is a subtype name, then the
2055 -- node denotes a slice (note that the case of an explicit range
2056 -- for a slice was already built as an N_Slice node in the first
2057 -- place, so that case is not handled here).
2059 -- We use a replace rather than a rewrite here because this is one
2060 -- of the cases in which the tree built by the parser is plain wrong.
2063 and then Is_Entity_Name (Exp)
2064 and then Is_Type (Entity (Exp))
2067 Make_Slice (Sloc (N),
2069 Discrete_Range => New_Copy (Exp)));
2072 -- Otherwise (more than one index present, or single index is not
2073 -- a subtype name), then we have the indexed component case.
2076 Process_Indexed_Component;
2078 end Process_Indexed_Component_Or_Slice;
2080 ------------------------------------------
2081 -- Process_Overloaded_Indexed_Component --
2082 ------------------------------------------
2084 procedure Process_Overloaded_Indexed_Component is
2093 Set_Etype (N, Any_Type);
2095 Get_First_Interp (P, I, It);
2096 while Present (It.Nam) loop
2099 if Is_Access_Type (Typ) then
2100 Typ := Designated_Type (Typ);
2101 Error_Msg_NW (Warn_On_Dereference, "?implicit dereference", N);
2104 if Is_Array_Type (Typ) then
2106 -- Got a candidate: verify that index types are compatible
2108 Index := First_Index (Typ);
2110 Exp := First (Exprs);
2111 while Present (Index) and then Present (Exp) loop
2112 if Has_Compatible_Type (Exp, Etype (Index)) then
2124 if Found and then No (Index) and then No (Exp) then
2126 Etype (Component_Type (Typ)),
2127 Etype (Component_Type (Typ)));
2131 Get_Next_Interp (I, It);
2134 if Etype (N) = Any_Type then
2135 Error_Msg_N ("no legal interpretation for indexed component", N);
2136 Set_Is_Overloaded (N, False);
2140 end Process_Overloaded_Indexed_Component;
2142 -- Start of processing for Analyze_Indexed_Component_Form
2145 -- Get name of array, function or type
2149 if Nkind_In (N, N_Function_Call, N_Procedure_Call_Statement) then
2151 -- If P is an explicit dereference whose prefix is of a
2152 -- remote access-to-subprogram type, then N has already
2153 -- been rewritten as a subprogram call and analyzed.
2158 pragma Assert (Nkind (N) = N_Indexed_Component);
2160 P_T := Base_Type (Etype (P));
2162 if Is_Entity_Name (P) and then Present (Entity (P)) then
2165 if Is_Type (U_N) then
2167 -- Reformat node as a type conversion
2169 E := Remove_Head (Exprs);
2171 if Present (First (Exprs)) then
2173 ("argument of type conversion must be single expression", N);
2176 Change_Node (N, N_Type_Conversion);
2177 Set_Subtype_Mark (N, P);
2179 Set_Expression (N, E);
2181 -- After changing the node, call for the specific Analysis
2182 -- routine directly, to avoid a double call to the expander.
2184 Analyze_Type_Conversion (N);
2188 if Is_Overloadable (U_N) then
2189 Process_Function_Call;
2191 elsif Ekind (Etype (P)) = E_Subprogram_Type
2192 or else (Is_Access_Type (Etype (P))
2194 Ekind (Designated_Type (Etype (P))) =
2197 -- Call to access_to-subprogram with possible implicit dereference
2199 Process_Function_Call;
2201 elsif Is_Generic_Subprogram (U_N) then
2203 -- A common beginner's (or C++ templates fan) error
2205 Error_Msg_N ("generic subprogram cannot be called", N);
2206 Set_Etype (N, Any_Type);
2210 Process_Indexed_Component_Or_Slice;
2213 -- If not an entity name, prefix is an expression that may denote
2214 -- an array or an access-to-subprogram.
2217 if Ekind (P_T) = E_Subprogram_Type
2218 or else (Is_Access_Type (P_T)
2220 Ekind (Designated_Type (P_T)) = E_Subprogram_Type)
2222 Process_Function_Call;
2224 elsif Nkind (P) = N_Selected_Component
2225 and then Is_Overloadable (Entity (Selector_Name (P)))
2227 Process_Function_Call;
2230 -- Indexed component, slice, or a call to a member of a family
2231 -- entry, which will be converted to an entry call later.
2233 Process_Indexed_Component_Or_Slice;
2236 end Analyze_Indexed_Component_Form;
2238 ------------------------
2239 -- Analyze_Logical_Op --
2240 ------------------------
2242 procedure Analyze_Logical_Op (N : Node_Id) is
2243 L : constant Node_Id := Left_Opnd (N);
2244 R : constant Node_Id := Right_Opnd (N);
2245 Op_Id : Entity_Id := Entity (N);
2248 Set_Etype (N, Any_Type);
2249 Candidate_Type := Empty;
2251 Analyze_Expression (L);
2252 Analyze_Expression (R);
2254 if Present (Op_Id) then
2256 if Ekind (Op_Id) = E_Operator then
2257 Find_Boolean_Types (L, R, Op_Id, N);
2259 Add_One_Interp (N, Op_Id, Etype (Op_Id));
2263 Op_Id := Get_Name_Entity_Id (Chars (N));
2264 while Present (Op_Id) loop
2265 if Ekind (Op_Id) = E_Operator then
2266 Find_Boolean_Types (L, R, Op_Id, N);
2268 Analyze_User_Defined_Binary_Op (N, Op_Id);
2271 Op_Id := Homonym (Op_Id);
2276 end Analyze_Logical_Op;
2278 ---------------------------
2279 -- Analyze_Membership_Op --
2280 ---------------------------
2282 procedure Analyze_Membership_Op (N : Node_Id) is
2283 Loc : constant Source_Ptr := Sloc (N);
2284 L : constant Node_Id := Left_Opnd (N);
2285 R : constant Node_Id := Right_Opnd (N);
2287 Index : Interp_Index;
2289 Found : Boolean := False;
2293 procedure Try_One_Interp (T1 : Entity_Id);
2294 -- Routine to try one proposed interpretation. Note that the context
2295 -- of the operation plays no role in resolving the arguments, so that
2296 -- if there is more than one interpretation of the operands that is
2297 -- compatible with a membership test, the operation is ambiguous.
2299 --------------------
2300 -- Try_One_Interp --
2301 --------------------
2303 procedure Try_One_Interp (T1 : Entity_Id) is
2305 if Has_Compatible_Type (R, T1) then
2307 and then Base_Type (T1) /= Base_Type (T_F)
2309 It := Disambiguate (L, I_F, Index, Any_Type);
2311 if It = No_Interp then
2312 Ambiguous_Operands (N);
2313 Set_Etype (L, Any_Type);
2330 procedure Analyze_Set_Membership;
2331 -- If a set of alternatives is present, analyze each and find the
2332 -- common type to which they must all resolve.
2334 ----------------------------
2335 -- Analyze_Set_Membership --
2336 ----------------------------
2338 procedure Analyze_Set_Membership is
2340 Index : Interp_Index;
2342 Candidate_Interps : Node_Id;
2343 Common_Type : Entity_Id := Empty;
2347 Candidate_Interps := L;
2349 if not Is_Overloaded (L) then
2350 Common_Type := Etype (L);
2352 Alt := First (Alternatives (N));
2353 while Present (Alt) loop
2356 if not Has_Compatible_Type (Alt, Common_Type) then
2357 Wrong_Type (Alt, Common_Type);
2364 Alt := First (Alternatives (N));
2365 while Present (Alt) loop
2367 if not Is_Overloaded (Alt) then
2368 Common_Type := Etype (Alt);
2371 Get_First_Interp (Alt, Index, It);
2372 while Present (It.Typ) loop
2374 Has_Compatible_Type (Candidate_Interps, It.Typ)
2376 Remove_Interp (Index);
2379 Get_Next_Interp (Index, It);
2382 Get_First_Interp (Alt, Index, It);
2385 Error_Msg_N ("alternative has no legal type", Alt);
2389 -- If alternative is not overloaded, we have a unique type
2392 Set_Etype (Alt, It.Typ);
2393 Get_Next_Interp (Index, It);
2396 Set_Is_Overloaded (Alt, False);
2397 Common_Type := Etype (Alt);
2400 Candidate_Interps := Alt;
2407 Set_Etype (N, Standard_Boolean);
2409 if Present (Common_Type) then
2410 Set_Etype (L, Common_Type);
2411 Set_Is_Overloaded (L, False);
2414 Error_Msg_N ("cannot resolve membership operation", N);
2416 end Analyze_Set_Membership;
2418 -- Start of processing for Analyze_Membership_Op
2421 Analyze_Expression (L);
2424 and then Ada_Version >= Ada_2012
2426 Analyze_Set_Membership;
2430 if Nkind (R) = N_Range
2431 or else (Nkind (R) = N_Attribute_Reference
2432 and then Attribute_Name (R) = Name_Range)
2436 if not Is_Overloaded (L) then
2437 Try_One_Interp (Etype (L));
2440 Get_First_Interp (L, Index, It);
2441 while Present (It.Typ) loop
2442 Try_One_Interp (It.Typ);
2443 Get_Next_Interp (Index, It);
2447 -- If not a range, it can be a subtype mark, or else it is a degenerate
2448 -- membership test with a singleton value, i.e. a test for equality.
2452 if Is_Entity_Name (R)
2453 and then Is_Type (Entity (R))
2456 Check_Fully_Declared (Entity (R), R);
2458 elsif Ada_Version >= Ada_2012 then
2459 if Nkind (N) = N_In then
2475 -- In previous version of the language this is an error that will
2476 -- be diagnosed below.
2482 -- Compatibility between expression and subtype mark or range is
2483 -- checked during resolution. The result of the operation is Boolean
2486 Set_Etype (N, Standard_Boolean);
2488 if Comes_From_Source (N)
2489 and then Present (Right_Opnd (N))
2490 and then Is_CPP_Class (Etype (Etype (Right_Opnd (N))))
2492 Error_Msg_N ("membership test not applicable to cpp-class types", N);
2494 end Analyze_Membership_Op;
2496 ----------------------
2497 -- Analyze_Negation --
2498 ----------------------
2500 procedure Analyze_Negation (N : Node_Id) is
2501 R : constant Node_Id := Right_Opnd (N);
2502 Op_Id : Entity_Id := Entity (N);
2505 Set_Etype (N, Any_Type);
2506 Candidate_Type := Empty;
2508 Analyze_Expression (R);
2510 if Present (Op_Id) then
2511 if Ekind (Op_Id) = E_Operator then
2512 Find_Negation_Types (R, Op_Id, N);
2514 Add_One_Interp (N, Op_Id, Etype (Op_Id));
2518 Op_Id := Get_Name_Entity_Id (Chars (N));
2519 while Present (Op_Id) loop
2520 if Ekind (Op_Id) = E_Operator then
2521 Find_Negation_Types (R, Op_Id, N);
2523 Analyze_User_Defined_Unary_Op (N, Op_Id);
2526 Op_Id := Homonym (Op_Id);
2531 end Analyze_Negation;
2537 procedure Analyze_Null (N : Node_Id) is
2539 Set_Etype (N, Any_Access);
2542 ----------------------
2543 -- Analyze_One_Call --
2544 ----------------------
2546 procedure Analyze_One_Call
2550 Success : out Boolean;
2551 Skip_First : Boolean := False)
2553 Actuals : constant List_Id := Parameter_Associations (N);
2554 Prev_T : constant Entity_Id := Etype (N);
2556 Must_Skip : constant Boolean := Skip_First
2557 or else Nkind (Original_Node (N)) = N_Selected_Component
2559 (Nkind (Original_Node (N)) = N_Indexed_Component
2560 and then Nkind (Prefix (Original_Node (N)))
2561 = N_Selected_Component);
2562 -- The first formal must be omitted from the match when trying to find
2563 -- a primitive operation that is a possible interpretation, and also
2564 -- after the call has been rewritten, because the corresponding actual
2565 -- is already known to be compatible, and because this may be an
2566 -- indexing of a call with default parameters.
2570 Is_Indexed : Boolean := False;
2571 Is_Indirect : Boolean := False;
2572 Subp_Type : constant Entity_Id := Etype (Nam);
2575 function Operator_Hidden_By (Fun : Entity_Id) return Boolean;
2576 -- There may be a user-defined operator that hides the current
2577 -- interpretation. We must check for this independently of the
2578 -- analysis of the call with the user-defined operation, because
2579 -- the parameter names may be wrong and yet the hiding takes place.
2580 -- This fixes a problem with ACATS test B34014O.
2582 -- When the type Address is a visible integer type, and the DEC
2583 -- system extension is visible, the predefined operator may be
2584 -- hidden as well, by one of the address operations in auxdec.
2585 -- Finally, The abstract operations on address do not hide the
2586 -- predefined operator (this is the purpose of making them abstract).
2588 procedure Indicate_Name_And_Type;
2589 -- If candidate interpretation matches, indicate name and type of
2590 -- result on call node.
2592 ----------------------------
2593 -- Indicate_Name_And_Type --
2594 ----------------------------
2596 procedure Indicate_Name_And_Type is
2598 Add_One_Interp (N, Nam, Etype (Nam));
2601 -- If the prefix of the call is a name, indicate the entity
2602 -- being called. If it is not a name, it is an expression that
2603 -- denotes an access to subprogram or else an entry or family. In
2604 -- the latter case, the name is a selected component, and the entity
2605 -- being called is noted on the selector.
2607 if not Is_Type (Nam) then
2608 if Is_Entity_Name (Name (N)) then
2609 Set_Entity (Name (N), Nam);
2611 elsif Nkind (Name (N)) = N_Selected_Component then
2612 Set_Entity (Selector_Name (Name (N)), Nam);
2616 if Debug_Flag_E and not Report then
2617 Write_Str (" Overloaded call ");
2618 Write_Int (Int (N));
2619 Write_Str (" compatible with ");
2620 Write_Int (Int (Nam));
2623 end Indicate_Name_And_Type;
2625 ------------------------
2626 -- Operator_Hidden_By --
2627 ------------------------
2629 function Operator_Hidden_By (Fun : Entity_Id) return Boolean is
2630 Act1 : constant Node_Id := First_Actual (N);
2631 Act2 : constant Node_Id := Next_Actual (Act1);
2632 Form1 : constant Entity_Id := First_Formal (Fun);
2633 Form2 : constant Entity_Id := Next_Formal (Form1);
2636 if Ekind (Fun) /= E_Function
2637 or else Is_Abstract_Subprogram (Fun)
2641 elsif not Has_Compatible_Type (Act1, Etype (Form1)) then
2644 elsif Present (Form2) then
2646 No (Act2) or else not Has_Compatible_Type (Act2, Etype (Form2))
2651 elsif Present (Act2) then
2655 -- Now we know that the arity of the operator matches the function,
2656 -- and the function call is a valid interpretation. The function
2657 -- hides the operator if it has the right signature, or if one of
2658 -- its operands is a non-abstract operation on Address when this is
2659 -- a visible integer type.
2661 return Hides_Op (Fun, Nam)
2662 or else Is_Descendent_Of_Address (Etype (Form1))
2665 and then Is_Descendent_Of_Address (Etype (Form2)));
2666 end Operator_Hidden_By;
2668 -- Start of processing for Analyze_One_Call
2673 -- If the subprogram has no formals or if all the formals have defaults,
2674 -- and the return type is an array type, the node may denote an indexing
2675 -- of the result of a parameterless call. In Ada 2005, the subprogram
2676 -- may have one non-defaulted formal, and the call may have been written
2677 -- in prefix notation, so that the rebuilt parameter list has more than
2680 if not Is_Overloadable (Nam)
2681 and then Ekind (Nam) /= E_Subprogram_Type
2682 and then Ekind (Nam) /= E_Entry_Family
2687 -- An indexing requires at least one actual
2689 if not Is_Empty_List (Actuals)
2691 (Needs_No_Actuals (Nam)
2693 (Needs_One_Actual (Nam)
2694 and then Present (Next_Actual (First (Actuals)))))
2696 if Is_Array_Type (Subp_Type) then
2697 Is_Indexed := Try_Indexed_Call (N, Nam, Subp_Type, Must_Skip);
2699 elsif Is_Access_Type (Subp_Type)
2700 and then Is_Array_Type (Designated_Type (Subp_Type))
2704 (N, Nam, Designated_Type (Subp_Type), Must_Skip);
2706 -- The prefix can also be a parameterless function that returns an
2707 -- access to subprogram, in which case this is an indirect call.
2708 -- If this succeeds, an explicit dereference is added later on,
2709 -- in Analyze_Call or Resolve_Call.
2711 elsif Is_Access_Type (Subp_Type)
2712 and then Ekind (Designated_Type (Subp_Type)) = E_Subprogram_Type
2714 Is_Indirect := Try_Indirect_Call (N, Nam, Subp_Type);
2719 -- If the call has been transformed into a slice, it is of the form
2720 -- F (Subtype) where F is parameterless. The node has been rewritten in
2721 -- Try_Indexed_Call and there is nothing else to do.
2724 and then Nkind (N) = N_Slice
2730 (N, Nam, (Report and not Is_Indexed and not Is_Indirect), Norm_OK);
2734 -- If an indirect call is a possible interpretation, indicate
2735 -- success to the caller.
2741 -- Mismatch in number or names of parameters
2743 elsif Debug_Flag_E then
2744 Write_Str (" normalization fails in call ");
2745 Write_Int (Int (N));
2746 Write_Str (" with subprogram ");
2747 Write_Int (Int (Nam));
2751 -- If the context expects a function call, discard any interpretation
2752 -- that is a procedure. If the node is not overloaded, leave as is for
2753 -- better error reporting when type mismatch is found.
2755 elsif Nkind (N) = N_Function_Call
2756 and then Is_Overloaded (Name (N))
2757 and then Ekind (Nam) = E_Procedure
2761 -- Ditto for function calls in a procedure context
2763 elsif Nkind (N) = N_Procedure_Call_Statement
2764 and then Is_Overloaded (Name (N))
2765 and then Etype (Nam) /= Standard_Void_Type
2769 elsif No (Actuals) then
2771 -- If Normalize succeeds, then there are default parameters for
2774 Indicate_Name_And_Type;
2776 elsif Ekind (Nam) = E_Operator then
2777 if Nkind (N) = N_Procedure_Call_Statement then
2781 -- This can occur when the prefix of the call is an operator
2782 -- name or an expanded name whose selector is an operator name.
2784 Analyze_Operator_Call (N, Nam);
2786 if Etype (N) /= Prev_T then
2788 -- Check that operator is not hidden by a function interpretation
2790 if Is_Overloaded (Name (N)) then
2796 Get_First_Interp (Name (N), I, It);
2797 while Present (It.Nam) loop
2798 if Operator_Hidden_By (It.Nam) then
2799 Set_Etype (N, Prev_T);
2803 Get_Next_Interp (I, It);
2808 -- If operator matches formals, record its name on the call.
2809 -- If the operator is overloaded, Resolve will select the
2810 -- correct one from the list of interpretations. The call
2811 -- node itself carries the first candidate.
2813 Set_Entity (Name (N), Nam);
2816 elsif Report and then Etype (N) = Any_Type then
2817 Error_Msg_N ("incompatible arguments for operator", N);
2821 -- Normalize_Actuals has chained the named associations in the
2822 -- correct order of the formals.
2824 Actual := First_Actual (N);
2825 Formal := First_Formal (Nam);
2827 -- If we are analyzing a call rewritten from object notation,
2828 -- skip first actual, which may be rewritten later as an
2829 -- explicit dereference.
2832 Next_Actual (Actual);
2833 Next_Formal (Formal);
2836 while Present (Actual) and then Present (Formal) loop
2837 if Nkind (Parent (Actual)) /= N_Parameter_Association
2838 or else Chars (Selector_Name (Parent (Actual))) = Chars (Formal)
2840 -- The actual can be compatible with the formal, but we must
2841 -- also check that the context is not an address type that is
2842 -- visibly an integer type, as is the case in VMS_64. In this
2843 -- case the use of literals is illegal, except in the body of
2844 -- descendents of system, where arithmetic operations on
2845 -- address are of course used.
2847 if Has_Compatible_Type (Actual, Etype (Formal))
2849 (Etype (Actual) /= Universal_Integer
2850 or else not Is_Descendent_Of_Address (Etype (Formal))
2852 Is_Predefined_File_Name
2853 (Unit_File_Name (Get_Source_Unit (N))))
2855 Next_Actual (Actual);
2856 Next_Formal (Formal);
2859 if Debug_Flag_E then
2860 Write_Str (" type checking fails in call ");
2861 Write_Int (Int (N));
2862 Write_Str (" with formal ");
2863 Write_Int (Int (Formal));
2864 Write_Str (" in subprogram ");
2865 Write_Int (Int (Nam));
2869 if Report and not Is_Indexed and not Is_Indirect then
2871 -- Ada 2005 (AI-251): Complete the error notification
2872 -- to help new Ada 2005 users.
2874 if Is_Class_Wide_Type (Etype (Formal))
2875 and then Is_Interface (Etype (Etype (Formal)))
2876 and then not Interface_Present_In_Ancestor
2877 (Typ => Etype (Actual),
2878 Iface => Etype (Etype (Formal)))
2881 ("(Ada 2005) does not implement interface }",
2882 Actual, Etype (Etype (Formal)));
2885 Wrong_Type (Actual, Etype (Formal));
2887 if Nkind (Actual) = N_Op_Eq
2888 and then Nkind (Left_Opnd (Actual)) = N_Identifier
2890 Formal := First_Formal (Nam);
2891 while Present (Formal) loop
2892 if Chars (Left_Opnd (Actual)) = Chars (Formal) then
2893 Error_Msg_N -- CODEFIX
2894 ("possible misspelling of `='>`!", Actual);
2898 Next_Formal (Formal);
2902 if All_Errors_Mode then
2903 Error_Msg_Sloc := Sloc (Nam);
2905 if Etype (Formal) = Any_Type then
2907 ("there is no legal actual parameter", Actual);
2910 if Is_Overloadable (Nam)
2911 and then Present (Alias (Nam))
2912 and then not Comes_From_Source (Nam)
2915 ("\\ =='> in call to inherited operation & #!",
2918 elsif Ekind (Nam) = E_Subprogram_Type then
2920 Access_To_Subprogram_Typ :
2921 constant Entity_Id :=
2923 (Associated_Node_For_Itype (Nam));
2926 "\\ =='> in call to dereference of &#!",
2927 Actual, Access_To_Subprogram_Typ);
2932 ("\\ =='> in call to &#!", Actual, Nam);
2942 -- Normalize_Actuals has verified that a default value exists
2943 -- for this formal. Current actual names a subsequent formal.
2945 Next_Formal (Formal);
2949 -- On exit, all actuals match
2951 Indicate_Name_And_Type;
2953 end Analyze_One_Call;
2955 ---------------------------
2956 -- Analyze_Operator_Call --
2957 ---------------------------
2959 procedure Analyze_Operator_Call (N : Node_Id; Op_Id : Entity_Id) is
2960 Op_Name : constant Name_Id := Chars (Op_Id);
2961 Act1 : constant Node_Id := First_Actual (N);
2962 Act2 : constant Node_Id := Next_Actual (Act1);
2965 -- Binary operator case
2967 if Present (Act2) then
2969 -- If more than two operands, then not binary operator after all
2971 if Present (Next_Actual (Act2)) then
2974 elsif Op_Name = Name_Op_Add
2975 or else Op_Name = Name_Op_Subtract
2976 or else Op_Name = Name_Op_Multiply
2977 or else Op_Name = Name_Op_Divide
2978 or else Op_Name = Name_Op_Mod
2979 or else Op_Name = Name_Op_Rem
2980 or else Op_Name = Name_Op_Expon
2982 Find_Arithmetic_Types (Act1, Act2, Op_Id, N);
2984 elsif Op_Name = Name_Op_And
2985 or else Op_Name = Name_Op_Or
2986 or else Op_Name = Name_Op_Xor
2988 Find_Boolean_Types (Act1, Act2, Op_Id, N);
2990 elsif Op_Name = Name_Op_Lt
2991 or else Op_Name = Name_Op_Le
2992 or else Op_Name = Name_Op_Gt
2993 or else Op_Name = Name_Op_Ge
2995 Find_Comparison_Types (Act1, Act2, Op_Id, N);
2997 elsif Op_Name = Name_Op_Eq
2998 or else Op_Name = Name_Op_Ne
3000 Find_Equality_Types (Act1, Act2, Op_Id, N);
3002 elsif Op_Name = Name_Op_Concat then
3003 Find_Concatenation_Types (Act1, Act2, Op_Id, N);
3005 -- Is this else null correct, or should it be an abort???
3011 -- Unary operator case
3014 if Op_Name = Name_Op_Subtract or else
3015 Op_Name = Name_Op_Add or else
3016 Op_Name = Name_Op_Abs
3018 Find_Unary_Types (Act1, Op_Id, N);
3021 Op_Name = Name_Op_Not
3023 Find_Negation_Types (Act1, Op_Id, N);
3025 -- Is this else null correct, or should it be an abort???
3031 end Analyze_Operator_Call;
3033 -------------------------------------------
3034 -- Analyze_Overloaded_Selected_Component --
3035 -------------------------------------------
3037 procedure Analyze_Overloaded_Selected_Component (N : Node_Id) is
3038 Nam : constant Node_Id := Prefix (N);
3039 Sel : constant Node_Id := Selector_Name (N);
3046 Set_Etype (Sel, Any_Type);
3048 Get_First_Interp (Nam, I, It);
3049 while Present (It.Typ) loop
3050 if Is_Access_Type (It.Typ) then
3051 T := Designated_Type (It.Typ);
3052 Error_Msg_NW (Warn_On_Dereference, "?implicit dereference", N);
3057 if Is_Record_Type (T) then
3059 -- If the prefix is a class-wide type, the visible components are
3060 -- those of the base type.
3062 if Is_Class_Wide_Type (T) then
3066 Comp := First_Entity (T);
3067 while Present (Comp) loop
3068 if Chars (Comp) = Chars (Sel)
3069 and then Is_Visible_Component (Comp)
3072 -- AI05-105: if the context is an object renaming with
3073 -- an anonymous access type, the expected type of the
3074 -- object must be anonymous. This is a name resolution rule.
3076 if Nkind (Parent (N)) /= N_Object_Renaming_Declaration
3077 or else No (Access_Definition (Parent (N)))
3078 or else Ekind (Etype (Comp)) = E_Anonymous_Access_Type
3080 Ekind (Etype (Comp)) = E_Anonymous_Access_Subprogram_Type
3082 Set_Entity (Sel, Comp);
3083 Set_Etype (Sel, Etype (Comp));
3084 Add_One_Interp (N, Etype (Comp), Etype (Comp));
3086 -- This also specifies a candidate to resolve the name.
3087 -- Further overloading will be resolved from context.
3088 -- The selector name itself does not carry overloading
3091 Set_Etype (Nam, It.Typ);
3094 -- Named access type in the context of a renaming
3095 -- declaration with an access definition. Remove
3096 -- inapplicable candidate.
3105 elsif Is_Concurrent_Type (T) then
3106 Comp := First_Entity (T);
3107 while Present (Comp)
3108 and then Comp /= First_Private_Entity (T)
3110 if Chars (Comp) = Chars (Sel) then
3111 if Is_Overloadable (Comp) then
3112 Add_One_Interp (Sel, Comp, Etype (Comp));
3114 Set_Entity_With_Style_Check (Sel, Comp);
3115 Generate_Reference (Comp, Sel);
3118 Set_Etype (Sel, Etype (Comp));
3119 Set_Etype (N, Etype (Comp));
3120 Set_Etype (Nam, It.Typ);
3122 -- For access type case, introduce explicit dereference for
3123 -- more uniform treatment of entry calls. Do this only once
3124 -- if several interpretations yield an access type.
3126 if Is_Access_Type (Etype (Nam))
3127 and then Nkind (Nam) /= N_Explicit_Dereference
3129 Insert_Explicit_Dereference (Nam);
3131 (Warn_On_Dereference, "?implicit dereference", N);
3138 Set_Is_Overloaded (N, Is_Overloaded (Sel));
3141 Get_Next_Interp (I, It);
3144 if Etype (N) = Any_Type
3145 and then not Try_Object_Operation (N)
3147 Error_Msg_NE ("undefined selector& for overloaded prefix", N, Sel);
3148 Set_Entity (Sel, Any_Id);
3149 Set_Etype (Sel, Any_Type);
3151 end Analyze_Overloaded_Selected_Component;
3153 ----------------------------------
3154 -- Analyze_Qualified_Expression --
3155 ----------------------------------
3157 procedure Analyze_Qualified_Expression (N : Node_Id) is
3158 Mark : constant Entity_Id := Subtype_Mark (N);
3159 Expr : constant Node_Id := Expression (N);
3165 Analyze_Expression (Expr);
3167 Set_Etype (N, Any_Type);
3172 if T = Any_Type then
3176 Check_Fully_Declared (T, N);
3178 -- If expected type is class-wide, check for exact match before
3179 -- expansion, because if the expression is a dispatching call it
3180 -- may be rewritten as explicit dereference with class-wide result.
3181 -- If expression is overloaded, retain only interpretations that
3182 -- will yield exact matches.
3184 if Is_Class_Wide_Type (T) then
3185 if not Is_Overloaded (Expr) then
3186 if Base_Type (Etype (Expr)) /= Base_Type (T) then
3187 if Nkind (Expr) = N_Aggregate then
3188 Error_Msg_N ("type of aggregate cannot be class-wide", Expr);
3190 Wrong_Type (Expr, T);
3195 Get_First_Interp (Expr, I, It);
3197 while Present (It.Nam) loop
3198 if Base_Type (It.Typ) /= Base_Type (T) then
3202 Get_Next_Interp (I, It);
3208 end Analyze_Qualified_Expression;
3210 -----------------------------------
3211 -- Analyze_Quantified_Expression --
3212 -----------------------------------
3214 procedure Analyze_Quantified_Expression (N : Node_Id) is
3215 Loc : constant Source_Ptr := Sloc (N);
3216 Ent : constant Entity_Id :=
3218 (E_Loop, Current_Scope, Sloc (N), 'L');
3223 Set_Etype (Ent, Standard_Void_Type);
3224 Set_Parent (Ent, N);
3226 if Present (Loop_Parameter_Specification (N)) then
3228 Make_Iteration_Scheme (Loc,
3229 Loop_Parameter_Specification =>
3230 Loop_Parameter_Specification (N));
3233 Make_Iteration_Scheme (Loc,
3234 Iterator_Specification =>
3235 Iterator_Specification (N));
3239 Set_Parent (Iterator, N);
3240 Analyze_Iteration_Scheme (Iterator);
3242 -- The loop specification may have been converted into an
3243 -- iterator specification during its analysis. Update the
3244 -- quantified node accordingly.
3246 if Present (Iterator_Specification (Iterator)) then
3247 Set_Iterator_Specification
3248 (N, Iterator_Specification (Iterator));
3249 Set_Loop_Parameter_Specification (N, Empty);
3252 Analyze (Condition (N));
3255 Set_Etype (N, Standard_Boolean);
3256 end Analyze_Quantified_Expression;
3262 procedure Analyze_Range (N : Node_Id) is
3263 L : constant Node_Id := Low_Bound (N);
3264 H : constant Node_Id := High_Bound (N);
3265 I1, I2 : Interp_Index;
3268 procedure Check_Common_Type (T1, T2 : Entity_Id);
3269 -- Verify the compatibility of two types, and choose the
3270 -- non universal one if the other is universal.
3272 procedure Check_High_Bound (T : Entity_Id);
3273 -- Test one interpretation of the low bound against all those
3274 -- of the high bound.
3276 procedure Check_Universal_Expression (N : Node_Id);
3277 -- In Ada83, reject bounds of a universal range that are not
3278 -- literals or entity names.
3280 -----------------------
3281 -- Check_Common_Type --
3282 -----------------------
3284 procedure Check_Common_Type (T1, T2 : Entity_Id) is
3286 if Covers (T1 => T1, T2 => T2)
3288 Covers (T1 => T2, T2 => T1)
3290 if T1 = Universal_Integer
3291 or else T1 = Universal_Real
3292 or else T1 = Any_Character
3294 Add_One_Interp (N, Base_Type (T2), Base_Type (T2));
3297 Add_One_Interp (N, T1, T1);
3300 Add_One_Interp (N, Base_Type (T1), Base_Type (T1));
3303 end Check_Common_Type;
3305 ----------------------
3306 -- Check_High_Bound --
3307 ----------------------
3309 procedure Check_High_Bound (T : Entity_Id) is
3311 if not Is_Overloaded (H) then
3312 Check_Common_Type (T, Etype (H));
3314 Get_First_Interp (H, I2, It2);
3315 while Present (It2.Typ) loop
3316 Check_Common_Type (T, It2.Typ);
3317 Get_Next_Interp (I2, It2);
3320 end Check_High_Bound;
3322 -----------------------------
3323 -- Is_Universal_Expression --
3324 -----------------------------
3326 procedure Check_Universal_Expression (N : Node_Id) is
3328 if Etype (N) = Universal_Integer
3329 and then Nkind (N) /= N_Integer_Literal
3330 and then not Is_Entity_Name (N)
3331 and then Nkind (N) /= N_Attribute_Reference
3333 Error_Msg_N ("illegal bound in discrete range", N);
3335 end Check_Universal_Expression;
3337 -- Start of processing for Analyze_Range
3340 Set_Etype (N, Any_Type);
3341 Analyze_Expression (L);
3342 Analyze_Expression (H);
3344 if Etype (L) = Any_Type or else Etype (H) = Any_Type then
3348 if not Is_Overloaded (L) then
3349 Check_High_Bound (Etype (L));
3351 Get_First_Interp (L, I1, It1);
3352 while Present (It1.Typ) loop
3353 Check_High_Bound (It1.Typ);
3354 Get_Next_Interp (I1, It1);
3358 -- If result is Any_Type, then we did not find a compatible pair
3360 if Etype (N) = Any_Type then
3361 Error_Msg_N ("incompatible types in range ", N);
3365 if Ada_Version = Ada_83
3367 (Nkind (Parent (N)) = N_Loop_Parameter_Specification
3368 or else Nkind (Parent (N)) = N_Constrained_Array_Definition)
3370 Check_Universal_Expression (L);
3371 Check_Universal_Expression (H);
3375 -----------------------
3376 -- Analyze_Reference --
3377 -----------------------
3379 procedure Analyze_Reference (N : Node_Id) is
3380 P : constant Node_Id := Prefix (N);
3383 Acc_Type : Entity_Id;
3388 -- An interesting error check, if we take the 'Reference of an object
3389 -- for which a pragma Atomic or Volatile has been given, and the type
3390 -- of the object is not Atomic or Volatile, then we are in trouble. The
3391 -- problem is that no trace of the atomic/volatile status will remain
3392 -- for the backend to respect when it deals with the resulting pointer,
3393 -- since the pointer type will not be marked atomic (it is a pointer to
3394 -- the base type of the object).
3396 -- It is not clear if that can ever occur, but in case it does, we will
3397 -- generate an error message. Not clear if this message can ever be
3398 -- generated, and pretty clear that it represents a bug if it is, still
3399 -- seems worth checking, except in CodePeer mode where we do not really
3400 -- care and don't want to bother the user.
3404 if Is_Entity_Name (P)
3405 and then Is_Object_Reference (P)
3406 and then not CodePeer_Mode
3411 if (Has_Atomic_Components (E)
3412 and then not Has_Atomic_Components (T))
3414 (Has_Volatile_Components (E)
3415 and then not Has_Volatile_Components (T))
3416 or else (Is_Atomic (E) and then not Is_Atomic (T))
3417 or else (Is_Volatile (E) and then not Is_Volatile (T))
3419 Error_Msg_N ("cannot take reference to Atomic/Volatile object", N);
3423 -- Carry on with normal processing
3425 Acc_Type := Create_Itype (E_Allocator_Type, N);
3426 Set_Etype (Acc_Type, Acc_Type);
3427 Set_Directly_Designated_Type (Acc_Type, Etype (P));
3428 Set_Etype (N, Acc_Type);
3429 end Analyze_Reference;
3431 --------------------------------
3432 -- Analyze_Selected_Component --
3433 --------------------------------
3435 -- Prefix is a record type or a task or protected type. In the latter case,
3436 -- the selector must denote a visible entry.
3438 procedure Analyze_Selected_Component (N : Node_Id) is
3439 Name : constant Node_Id := Prefix (N);
3440 Sel : constant Node_Id := Selector_Name (N);
3443 Has_Candidate : Boolean := False;
3446 Pent : Entity_Id := Empty;
3447 Prefix_Type : Entity_Id;
3449 Type_To_Use : Entity_Id;
3450 -- In most cases this is the Prefix_Type, but if the Prefix_Type is
3451 -- a class-wide type, we use its root type, whose components are
3452 -- present in the class-wide type.
3454 Is_Single_Concurrent_Object : Boolean;
3455 -- Set True if the prefix is a single task or a single protected object
3457 procedure Find_Component_In_Instance (Rec : Entity_Id);
3458 -- In an instance, a component of a private extension may not be visible
3459 -- while it was visible in the generic. Search candidate scope for a
3460 -- component with the proper identifier. This is only done if all other
3461 -- searches have failed. When the match is found (it always will be),
3462 -- the Etype of both N and Sel are set from this component, and the
3463 -- entity of Sel is set to reference this component.
3465 function Has_Mode_Conformant_Spec (Comp : Entity_Id) return Boolean;
3466 -- It is known that the parent of N denotes a subprogram call. Comp
3467 -- is an overloadable component of the concurrent type of the prefix.
3468 -- Determine whether all formals of the parent of N and Comp are mode
3469 -- conformant. If the parent node is not analyzed yet it may be an
3470 -- indexed component rather than a function call.
3472 --------------------------------
3473 -- Find_Component_In_Instance --
3474 --------------------------------
3476 procedure Find_Component_In_Instance (Rec : Entity_Id) is
3480 Comp := First_Component (Rec);
3481 while Present (Comp) loop
3482 if Chars (Comp) = Chars (Sel) then
3483 Set_Entity_With_Style_Check (Sel, Comp);
3484 Set_Etype (Sel, Etype (Comp));
3485 Set_Etype (N, Etype (Comp));
3489 Next_Component (Comp);
3492 -- This must succeed because code was legal in the generic
3494 raise Program_Error;
3495 end Find_Component_In_Instance;
3497 ------------------------------
3498 -- Has_Mode_Conformant_Spec --
3499 ------------------------------
3501 function Has_Mode_Conformant_Spec (Comp : Entity_Id) return Boolean is
3502 Comp_Param : Entity_Id;
3504 Param_Typ : Entity_Id;
3507 Comp_Param := First_Formal (Comp);
3509 if Nkind (Parent (N)) = N_Indexed_Component then
3510 Param := First (Expressions (Parent (N)));
3512 Param := First (Parameter_Associations (Parent (N)));
3515 while Present (Comp_Param)
3516 and then Present (Param)
3518 Param_Typ := Find_Parameter_Type (Param);
3520 if Present (Param_Typ)
3522 not Conforming_Types
3523 (Etype (Comp_Param), Param_Typ, Mode_Conformant)
3528 Next_Formal (Comp_Param);
3532 -- One of the specs has additional formals
3534 if Present (Comp_Param) or else Present (Param) then
3539 end Has_Mode_Conformant_Spec;
3541 -- Start of processing for Analyze_Selected_Component
3544 Set_Etype (N, Any_Type);
3546 if Is_Overloaded (Name) then
3547 Analyze_Overloaded_Selected_Component (N);
3550 elsif Etype (Name) = Any_Type then
3551 Set_Entity (Sel, Any_Id);
3552 Set_Etype (Sel, Any_Type);
3556 Prefix_Type := Etype (Name);
3559 if Is_Access_Type (Prefix_Type) then
3561 -- A RACW object can never be used as prefix of a selected component
3562 -- since that means it is dereferenced without being a controlling
3563 -- operand of a dispatching operation (RM E.2.2(16/1)). Before
3564 -- reporting an error, we must check whether this is actually a
3565 -- dispatching call in prefix form.
3567 if Is_Remote_Access_To_Class_Wide_Type (Prefix_Type)
3568 and then Comes_From_Source (N)
3570 if Try_Object_Operation (N) then
3574 ("invalid dereference of a remote access-to-class-wide value",
3578 -- Normal case of selected component applied to access type
3581 Error_Msg_NW (Warn_On_Dereference, "?implicit dereference", N);
3583 if Is_Entity_Name (Name) then
3584 Pent := Entity (Name);
3585 elsif Nkind (Name) = N_Selected_Component
3586 and then Is_Entity_Name (Selector_Name (Name))
3588 Pent := Entity (Selector_Name (Name));
3591 Prefix_Type := Process_Implicit_Dereference_Prefix (Pent, Name);
3594 -- If we have an explicit dereference of a remote access-to-class-wide
3595 -- value, then issue an error (see RM-E.2.2(16/1)). However we first
3596 -- have to check for the case of a prefix that is a controlling operand
3597 -- of a prefixed dispatching call, as the dereference is legal in that
3598 -- case. Normally this condition is checked in Validate_Remote_Access_
3599 -- To_Class_Wide_Type, but we have to defer the checking for selected
3600 -- component prefixes because of the prefixed dispatching call case.
3601 -- Note that implicit dereferences are checked for this just above.
3603 elsif Nkind (Name) = N_Explicit_Dereference
3604 and then Is_Remote_Access_To_Class_Wide_Type (Etype (Prefix (Name)))
3605 and then Comes_From_Source (N)
3607 if Try_Object_Operation (N) then
3611 ("invalid dereference of a remote access-to-class-wide value",
3616 -- (Ada 2005): if the prefix is the limited view of a type, and
3617 -- the context already includes the full view, use the full view
3618 -- in what follows, either to retrieve a component of to find
3619 -- a primitive operation. If the prefix is an explicit dereference,
3620 -- set the type of the prefix to reflect this transformation.
3621 -- If the non-limited view is itself an incomplete type, get the
3622 -- full view if available.
3624 if Is_Incomplete_Type (Prefix_Type)
3625 and then From_With_Type (Prefix_Type)
3626 and then Present (Non_Limited_View (Prefix_Type))
3628 Prefix_Type := Get_Full_View (Non_Limited_View (Prefix_Type));
3630 if Nkind (N) = N_Explicit_Dereference then
3631 Set_Etype (Prefix (N), Prefix_Type);
3634 elsif Ekind (Prefix_Type) = E_Class_Wide_Type
3635 and then From_With_Type (Prefix_Type)
3636 and then Present (Non_Limited_View (Etype (Prefix_Type)))
3639 Class_Wide_Type (Non_Limited_View (Etype (Prefix_Type)));
3641 if Nkind (N) = N_Explicit_Dereference then
3642 Set_Etype (Prefix (N), Prefix_Type);
3646 if Ekind (Prefix_Type) = E_Private_Subtype then
3647 Prefix_Type := Base_Type (Prefix_Type);
3650 Type_To_Use := Prefix_Type;
3652 -- For class-wide types, use the entity list of the root type. This
3653 -- indirection is specially important for private extensions because
3654 -- only the root type get switched (not the class-wide type).
3656 if Is_Class_Wide_Type (Prefix_Type) then
3657 Type_To_Use := Root_Type (Prefix_Type);
3660 -- If the prefix is a single concurrent object, use its name in error
3661 -- messages, rather than that of its anonymous type.
3663 Is_Single_Concurrent_Object :=
3664 Is_Concurrent_Type (Prefix_Type)
3665 and then Is_Internal_Name (Chars (Prefix_Type))
3666 and then not Is_Derived_Type (Prefix_Type)
3667 and then Is_Entity_Name (Name);
3669 Comp := First_Entity (Type_To_Use);
3671 -- If the selector has an original discriminant, the node appears in
3672 -- an instance. Replace the discriminant with the corresponding one
3673 -- in the current discriminated type. For nested generics, this must
3674 -- be done transitively, so note the new original discriminant.
3676 if Nkind (Sel) = N_Identifier
3677 and then Present (Original_Discriminant (Sel))
3679 Comp := Find_Corresponding_Discriminant (Sel, Prefix_Type);
3681 -- Mark entity before rewriting, for completeness and because
3682 -- subsequent semantic checks might examine the original node.
3684 Set_Entity (Sel, Comp);
3685 Rewrite (Selector_Name (N),
3686 New_Occurrence_Of (Comp, Sloc (N)));
3687 Set_Original_Discriminant (Selector_Name (N), Comp);
3688 Set_Etype (N, Etype (Comp));
3690 if Is_Access_Type (Etype (Name)) then
3691 Insert_Explicit_Dereference (Name);
3692 Error_Msg_NW (Warn_On_Dereference, "?implicit dereference", N);
3695 elsif Is_Record_Type (Prefix_Type) then
3697 -- Find component with given name
3699 while Present (Comp) loop
3700 if Chars (Comp) = Chars (Sel)
3701 and then Is_Visible_Component (Comp)
3703 Set_Entity_With_Style_Check (Sel, Comp);
3704 Set_Etype (Sel, Etype (Comp));
3706 if Ekind (Comp) = E_Discriminant then
3707 if Is_Unchecked_Union (Base_Type (Prefix_Type)) then
3709 ("cannot reference discriminant of Unchecked_Union",
3713 if Is_Generic_Type (Prefix_Type)
3715 Is_Generic_Type (Root_Type (Prefix_Type))
3717 Set_Original_Discriminant (Sel, Comp);
3721 -- Resolve the prefix early otherwise it is not possible to
3722 -- build the actual subtype of the component: it may need
3723 -- to duplicate this prefix and duplication is only allowed
3724 -- on fully resolved expressions.
3728 -- Ada 2005 (AI-50217): Check wrong use of incomplete types or
3729 -- subtypes in a package specification.
3732 -- limited with Pkg;
3734 -- type Acc_Inc is access Pkg.T;
3736 -- N : Natural := X.all.Comp; -- ERROR, limited view
3737 -- end Pkg; -- Comp is not visible
3739 if Nkind (Name) = N_Explicit_Dereference
3740 and then From_With_Type (Etype (Prefix (Name)))
3741 and then not Is_Potentially_Use_Visible (Etype (Name))
3742 and then Nkind (Parent (Cunit_Entity (Current_Sem_Unit))) =
3743 N_Package_Specification
3746 ("premature usage of incomplete}", Prefix (Name),
3747 Etype (Prefix (Name)));
3750 -- We never need an actual subtype for the case of a selection
3751 -- for a indexed component of a non-packed array, since in
3752 -- this case gigi generates all the checks and can find the
3753 -- necessary bounds information.
3755 -- We also do not need an actual subtype for the case of a
3756 -- first, last, length, or range attribute applied to a
3757 -- non-packed array, since gigi can again get the bounds in
3758 -- these cases (gigi cannot handle the packed case, since it
3759 -- has the bounds of the packed array type, not the original
3760 -- bounds of the type). However, if the prefix is itself a
3761 -- selected component, as in a.b.c (i), gigi may regard a.b.c
3762 -- as a dynamic-sized temporary, so we do generate an actual
3763 -- subtype for this case.
3765 Parent_N := Parent (N);
3767 if not Is_Packed (Etype (Comp))
3769 ((Nkind (Parent_N) = N_Indexed_Component
3770 and then Nkind (Name) /= N_Selected_Component)
3772 (Nkind (Parent_N) = N_Attribute_Reference
3773 and then (Attribute_Name (Parent_N) = Name_First
3775 Attribute_Name (Parent_N) = Name_Last
3777 Attribute_Name (Parent_N) = Name_Length
3779 Attribute_Name (Parent_N) = Name_Range)))
3781 Set_Etype (N, Etype (Comp));
3783 -- If full analysis is not enabled, we do not generate an
3784 -- actual subtype, because in the absence of expansion
3785 -- reference to a formal of a protected type, for example,
3786 -- will not be properly transformed, and will lead to
3787 -- out-of-scope references in gigi.
3789 -- In all other cases, we currently build an actual subtype.
3790 -- It seems likely that many of these cases can be avoided,
3791 -- but right now, the front end makes direct references to the
3792 -- bounds (e.g. in generating a length check), and if we do
3793 -- not make an actual subtype, we end up getting a direct
3794 -- reference to a discriminant, which will not do.
3796 elsif Full_Analysis then
3798 Build_Actual_Subtype_Of_Component (Etype (Comp), N);
3799 Insert_Action (N, Act_Decl);
3801 if No (Act_Decl) then
3802 Set_Etype (N, Etype (Comp));
3805 -- Component type depends on discriminants. Enter the
3806 -- main attributes of the subtype.
3809 Subt : constant Entity_Id :=
3810 Defining_Identifier (Act_Decl);
3813 Set_Etype (Subt, Base_Type (Etype (Comp)));
3814 Set_Ekind (Subt, Ekind (Etype (Comp)));
3815 Set_Etype (N, Subt);
3819 -- If Full_Analysis not enabled, just set the Etype
3822 Set_Etype (N, Etype (Comp));
3828 -- If the prefix is a private extension, check only the visible
3829 -- components of the partial view. This must include the tag,
3830 -- which can appear in expanded code in a tag check.
3832 if Ekind (Type_To_Use) = E_Record_Type_With_Private
3833 and then Chars (Selector_Name (N)) /= Name_uTag
3835 exit when Comp = Last_Entity (Type_To_Use);
3841 -- Ada 2005 (AI-252): The selected component can be interpreted as
3842 -- a prefixed view of a subprogram. Depending on the context, this is
3843 -- either a name that can appear in a renaming declaration, or part
3844 -- of an enclosing call given in prefix form.
3846 -- Ada 2005 (AI05-0030): In the case of dispatching requeue, the
3847 -- selected component should resolve to a name.
3849 if Ada_Version >= Ada_2005
3850 and then Is_Tagged_Type (Prefix_Type)
3851 and then not Is_Concurrent_Type (Prefix_Type)
3853 if Nkind (Parent (N)) = N_Generic_Association
3854 or else Nkind (Parent (N)) = N_Requeue_Statement
3855 or else Nkind (Parent (N)) = N_Subprogram_Renaming_Declaration
3857 if Find_Primitive_Operation (N) then
3861 elsif Try_Object_Operation (N) then
3865 -- If the transformation fails, it will be necessary to redo the
3866 -- analysis with all errors enabled, to indicate candidate
3867 -- interpretations and reasons for each failure ???
3871 elsif Is_Private_Type (Prefix_Type) then
3873 -- Allow access only to discriminants of the type. If the type has
3874 -- no full view, gigi uses the parent type for the components, so we
3875 -- do the same here.
3877 if No (Full_View (Prefix_Type)) then
3878 Type_To_Use := Root_Type (Base_Type (Prefix_Type));
3879 Comp := First_Entity (Type_To_Use);
3882 while Present (Comp) loop
3883 if Chars (Comp) = Chars (Sel) then
3884 if Ekind (Comp) = E_Discriminant then
3885 Set_Entity_With_Style_Check (Sel, Comp);
3886 Generate_Reference (Comp, Sel);
3888 Set_Etype (Sel, Etype (Comp));
3889 Set_Etype (N, Etype (Comp));
3891 if Is_Generic_Type (Prefix_Type)
3892 or else Is_Generic_Type (Root_Type (Prefix_Type))
3894 Set_Original_Discriminant (Sel, Comp);
3897 -- Before declaring an error, check whether this is tagged
3898 -- private type and a call to a primitive operation.
3900 elsif Ada_Version >= Ada_2005
3901 and then Is_Tagged_Type (Prefix_Type)
3902 and then Try_Object_Operation (N)
3907 Error_Msg_Node_2 := First_Subtype (Prefix_Type);
3908 Error_Msg_NE ("invisible selector& for }", N, Sel);
3909 Set_Entity (Sel, Any_Id);
3910 Set_Etype (N, Any_Type);
3919 elsif Is_Concurrent_Type (Prefix_Type) then
3921 -- Find visible operation with given name. For a protected type,
3922 -- the possible candidates are discriminants, entries or protected
3923 -- procedures. For a task type, the set can only include entries or
3924 -- discriminants if the task type is not an enclosing scope. If it
3925 -- is an enclosing scope (e.g. in an inner task) then all entities
3926 -- are visible, but the prefix must denote the enclosing scope, i.e.
3927 -- can only be a direct name or an expanded name.
3929 Set_Etype (Sel, Any_Type);
3930 In_Scope := In_Open_Scopes (Prefix_Type);
3932 while Present (Comp) loop
3933 if Chars (Comp) = Chars (Sel) then
3934 if Is_Overloadable (Comp) then
3935 Add_One_Interp (Sel, Comp, Etype (Comp));
3937 -- If the prefix is tagged, the correct interpretation may
3938 -- lie in the primitive or class-wide operations of the
3939 -- type. Perform a simple conformance check to determine
3940 -- whether Try_Object_Operation should be invoked even if
3941 -- a visible entity is found.
3943 if Is_Tagged_Type (Prefix_Type)
3945 Nkind_In (Parent (N), N_Procedure_Call_Statement,
3947 N_Indexed_Component)
3948 and then Has_Mode_Conformant_Spec (Comp)
3950 Has_Candidate := True;
3953 -- Note: a selected component may not denote a component of a
3954 -- protected type (4.1.3(7)).
3956 elsif Ekind_In (Comp, E_Discriminant, E_Entry_Family)
3958 and then not Is_Protected_Type (Prefix_Type)
3959 and then Is_Entity_Name (Name))
3961 Set_Entity_With_Style_Check (Sel, Comp);
3962 Generate_Reference (Comp, Sel);
3968 Set_Etype (Sel, Etype (Comp));
3969 Set_Etype (N, Etype (Comp));
3971 if Ekind (Comp) = E_Discriminant then
3972 Set_Original_Discriminant (Sel, Comp);
3975 -- For access type case, introduce explicit dereference for
3976 -- more uniform treatment of entry calls.
3978 if Is_Access_Type (Etype (Name)) then
3979 Insert_Explicit_Dereference (Name);
3981 (Warn_On_Dereference, "?implicit dereference", N);
3987 exit when not In_Scope
3989 Comp = First_Private_Entity (Base_Type (Prefix_Type));
3992 -- If there is no visible entity with the given name or none of the
3993 -- visible entities are plausible interpretations, check whether
3994 -- there is some other primitive operation with that name.
3996 if Ada_Version >= Ada_2005
3997 and then Is_Tagged_Type (Prefix_Type)
3999 if (Etype (N) = Any_Type
4000 or else not Has_Candidate)
4001 and then Try_Object_Operation (N)
4005 -- If the context is not syntactically a procedure call, it
4006 -- may be a call to a primitive function declared outside of
4007 -- the synchronized type.
4009 -- If the context is a procedure call, there might still be
4010 -- an overloading between an entry and a primitive procedure
4011 -- declared outside of the synchronized type, called in prefix
4012 -- notation. This is harder to disambiguate because in one case
4013 -- the controlling formal is implicit ???
4015 elsif Nkind (Parent (N)) /= N_Procedure_Call_Statement
4016 and then Nkind (Parent (N)) /= N_Indexed_Component
4017 and then Try_Object_Operation (N)
4023 if Etype (N) = Any_Type and then Is_Protected_Type (Prefix_Type) then
4024 -- Case of a prefix of a protected type: selector might denote
4025 -- an invisible private component.
4027 Comp := First_Private_Entity (Base_Type (Prefix_Type));
4028 while Present (Comp) and then Chars (Comp) /= Chars (Sel) loop
4032 if Present (Comp) then
4033 if Is_Single_Concurrent_Object then
4034 Error_Msg_Node_2 := Entity (Name);
4035 Error_Msg_NE ("invisible selector& for &", N, Sel);
4038 Error_Msg_Node_2 := First_Subtype (Prefix_Type);
4039 Error_Msg_NE ("invisible selector& for }", N, Sel);
4045 Set_Is_Overloaded (N, Is_Overloaded (Sel));
4050 Error_Msg_NE ("invalid prefix in selected component&", N, Sel);
4053 -- If N still has no type, the component is not defined in the prefix
4055 if Etype (N) = Any_Type then
4057 if Is_Single_Concurrent_Object then
4058 Error_Msg_Node_2 := Entity (Name);
4059 Error_Msg_NE ("no selector& for&", N, Sel);
4061 Check_Misspelled_Selector (Type_To_Use, Sel);
4063 elsif Is_Generic_Type (Prefix_Type)
4064 and then Ekind (Prefix_Type) = E_Record_Type_With_Private
4065 and then Prefix_Type /= Etype (Prefix_Type)
4066 and then Is_Record_Type (Etype (Prefix_Type))
4068 -- If this is a derived formal type, the parent may have
4069 -- different visibility at this point. Try for an inherited
4070 -- component before reporting an error.
4072 Set_Etype (Prefix (N), Etype (Prefix_Type));
4073 Analyze_Selected_Component (N);
4076 -- Similarly, if this is the actual for a formal derived type, the
4077 -- component inherited from the generic parent may not be visible
4078 -- in the actual, but the selected component is legal.
4080 elsif Ekind (Prefix_Type) = E_Record_Subtype_With_Private
4081 and then Is_Generic_Actual_Type (Prefix_Type)
4082 and then Present (Full_View (Prefix_Type))
4085 Find_Component_In_Instance
4086 (Generic_Parent_Type (Parent (Prefix_Type)));
4089 -- Finally, the formal and the actual may be private extensions,
4090 -- but the generic is declared in a child unit of the parent, and
4091 -- an additional step is needed to retrieve the proper scope.
4094 and then Present (Parent_Subtype (Etype (Base_Type (Prefix_Type))))
4096 Find_Component_In_Instance
4097 (Parent_Subtype (Etype (Base_Type (Prefix_Type))));
4100 -- Component not found, specialize error message when appropriate
4103 if Ekind (Prefix_Type) = E_Record_Subtype then
4105 -- Check whether this is a component of the base type which
4106 -- is absent from a statically constrained subtype. This will
4107 -- raise constraint error at run time, but is not a compile-
4108 -- time error. When the selector is illegal for base type as
4109 -- well fall through and generate a compilation error anyway.
4111 Comp := First_Component (Base_Type (Prefix_Type));
4112 while Present (Comp) loop
4113 if Chars (Comp) = Chars (Sel)
4114 and then Is_Visible_Component (Comp)
4116 Set_Entity_With_Style_Check (Sel, Comp);
4117 Generate_Reference (Comp, Sel);
4118 Set_Etype (Sel, Etype (Comp));
4119 Set_Etype (N, Etype (Comp));
4121 -- Emit appropriate message. Gigi will replace the
4122 -- node subsequently with the appropriate Raise.
4124 Apply_Compile_Time_Constraint_Error
4125 (N, "component not present in }?",
4126 CE_Discriminant_Check_Failed,
4127 Ent => Prefix_Type, Rep => False);
4128 Set_Raises_Constraint_Error (N);
4132 Next_Component (Comp);
4137 Error_Msg_Node_2 := First_Subtype (Prefix_Type);
4138 Error_Msg_NE ("no selector& for}", N, Sel);
4140 Check_Misspelled_Selector (Type_To_Use, Sel);
4143 Set_Entity (Sel, Any_Id);
4144 Set_Etype (Sel, Any_Type);
4146 end Analyze_Selected_Component;
4148 ---------------------------
4149 -- Analyze_Short_Circuit --
4150 ---------------------------
4152 procedure Analyze_Short_Circuit (N : Node_Id) is
4153 L : constant Node_Id := Left_Opnd (N);
4154 R : constant Node_Id := Right_Opnd (N);
4159 Analyze_Expression (L);
4160 Analyze_Expression (R);
4161 Set_Etype (N, Any_Type);
4163 if not Is_Overloaded (L) then
4164 if Root_Type (Etype (L)) = Standard_Boolean
4165 and then Has_Compatible_Type (R, Etype (L))
4167 Add_One_Interp (N, Etype (L), Etype (L));
4171 Get_First_Interp (L, Ind, It);
4172 while Present (It.Typ) loop
4173 if Root_Type (It.Typ) = Standard_Boolean
4174 and then Has_Compatible_Type (R, It.Typ)
4176 Add_One_Interp (N, It.Typ, It.Typ);
4179 Get_Next_Interp (Ind, It);
4183 -- Here we have failed to find an interpretation. Clearly we know that
4184 -- it is not the case that both operands can have an interpretation of
4185 -- Boolean, but this is by far the most likely intended interpretation.
4186 -- So we simply resolve both operands as Booleans, and at least one of
4187 -- these resolutions will generate an error message, and we do not need
4188 -- to give another error message on the short circuit operation itself.
4190 if Etype (N) = Any_Type then
4191 Resolve (L, Standard_Boolean);
4192 Resolve (R, Standard_Boolean);
4193 Set_Etype (N, Standard_Boolean);
4195 end Analyze_Short_Circuit;
4201 procedure Analyze_Slice (N : Node_Id) is
4202 P : constant Node_Id := Prefix (N);
4203 D : constant Node_Id := Discrete_Range (N);
4204 Array_Type : Entity_Id;
4206 procedure Analyze_Overloaded_Slice;
4207 -- If the prefix is overloaded, select those interpretations that
4208 -- yield a one-dimensional array type.
4210 ------------------------------
4211 -- Analyze_Overloaded_Slice --
4212 ------------------------------
4214 procedure Analyze_Overloaded_Slice is
4220 Set_Etype (N, Any_Type);
4222 Get_First_Interp (P, I, It);
4223 while Present (It.Nam) loop
4226 if Is_Access_Type (Typ) then
4227 Typ := Designated_Type (Typ);
4228 Error_Msg_NW (Warn_On_Dereference, "?implicit dereference", N);
4231 if Is_Array_Type (Typ)
4232 and then Number_Dimensions (Typ) = 1
4233 and then Has_Compatible_Type (D, Etype (First_Index (Typ)))
4235 Add_One_Interp (N, Typ, Typ);
4238 Get_Next_Interp (I, It);
4241 if Etype (N) = Any_Type then
4242 Error_Msg_N ("expect array type in prefix of slice", N);
4244 end Analyze_Overloaded_Slice;
4246 -- Start of processing for Analyze_Slice
4252 if Is_Overloaded (P) then
4253 Analyze_Overloaded_Slice;
4256 Array_Type := Etype (P);
4257 Set_Etype (N, Any_Type);
4259 if Is_Access_Type (Array_Type) then
4260 Array_Type := Designated_Type (Array_Type);
4261 Error_Msg_NW (Warn_On_Dereference, "?implicit dereference", N);
4264 if not Is_Array_Type (Array_Type) then
4265 Wrong_Type (P, Any_Array);
4267 elsif Number_Dimensions (Array_Type) > 1 then
4269 ("type is not one-dimensional array in slice prefix", N);
4272 Has_Compatible_Type (D, Etype (First_Index (Array_Type)))
4274 Wrong_Type (D, Etype (First_Index (Array_Type)));
4277 Set_Etype (N, Array_Type);
4282 -----------------------------
4283 -- Analyze_Type_Conversion --
4284 -----------------------------
4286 procedure Analyze_Type_Conversion (N : Node_Id) is
4287 Expr : constant Node_Id := Expression (N);
4291 -- If Conversion_OK is set, then the Etype is already set, and the
4292 -- only processing required is to analyze the expression. This is
4293 -- used to construct certain "illegal" conversions which are not
4294 -- allowed by Ada semantics, but can be handled OK by Gigi, see
4295 -- Sinfo for further details.
4297 if Conversion_OK (N) then
4302 -- Otherwise full type analysis is required, as well as some semantic
4303 -- checks to make sure the argument of the conversion is appropriate.
4305 Find_Type (Subtype_Mark (N));
4306 T := Entity (Subtype_Mark (N));
4308 Check_Fully_Declared (T, N);
4309 Analyze_Expression (Expr);
4310 Validate_Remote_Type_Type_Conversion (N);
4312 -- Only remaining step is validity checks on the argument. These
4313 -- are skipped if the conversion does not come from the source.
4315 if not Comes_From_Source (N) then
4318 -- If there was an error in a generic unit, no need to replicate the
4319 -- error message. Conversely, constant-folding in the generic may
4320 -- transform the argument of a conversion into a string literal, which
4321 -- is legal. Therefore the following tests are not performed in an
4324 elsif In_Instance then
4327 elsif Nkind (Expr) = N_Null then
4328 Error_Msg_N ("argument of conversion cannot be null", N);
4329 Error_Msg_N ("\use qualified expression instead", N);
4330 Set_Etype (N, Any_Type);
4332 elsif Nkind (Expr) = N_Aggregate then
4333 Error_Msg_N ("argument of conversion cannot be aggregate", N);
4334 Error_Msg_N ("\use qualified expression instead", N);
4336 elsif Nkind (Expr) = N_Allocator then
4337 Error_Msg_N ("argument of conversion cannot be an allocator", N);
4338 Error_Msg_N ("\use qualified expression instead", N);
4340 elsif Nkind (Expr) = N_String_Literal then
4341 Error_Msg_N ("argument of conversion cannot be string literal", N);
4342 Error_Msg_N ("\use qualified expression instead", N);
4344 elsif Nkind (Expr) = N_Character_Literal then
4345 if Ada_Version = Ada_83 then
4348 Error_Msg_N ("argument of conversion cannot be character literal",
4350 Error_Msg_N ("\use qualified expression instead", N);
4353 elsif Nkind (Expr) = N_Attribute_Reference
4355 (Attribute_Name (Expr) = Name_Access or else
4356 Attribute_Name (Expr) = Name_Unchecked_Access or else
4357 Attribute_Name (Expr) = Name_Unrestricted_Access)
4359 Error_Msg_N ("argument of conversion cannot be access", N);
4360 Error_Msg_N ("\use qualified expression instead", N);
4362 end Analyze_Type_Conversion;
4364 ----------------------
4365 -- Analyze_Unary_Op --
4366 ----------------------
4368 procedure Analyze_Unary_Op (N : Node_Id) is
4369 R : constant Node_Id := Right_Opnd (N);
4370 Op_Id : Entity_Id := Entity (N);
4373 Set_Etype (N, Any_Type);
4374 Candidate_Type := Empty;
4376 Analyze_Expression (R);
4378 if Present (Op_Id) then
4379 if Ekind (Op_Id) = E_Operator then
4380 Find_Unary_Types (R, Op_Id, N);
4382 Add_One_Interp (N, Op_Id, Etype (Op_Id));
4386 Op_Id := Get_Name_Entity_Id (Chars (N));
4387 while Present (Op_Id) loop
4388 if Ekind (Op_Id) = E_Operator then
4389 if No (Next_Entity (First_Entity (Op_Id))) then
4390 Find_Unary_Types (R, Op_Id, N);
4393 elsif Is_Overloadable (Op_Id) then
4394 Analyze_User_Defined_Unary_Op (N, Op_Id);
4397 Op_Id := Homonym (Op_Id);
4402 end Analyze_Unary_Op;
4404 ----------------------------------
4405 -- Analyze_Unchecked_Expression --
4406 ----------------------------------
4408 procedure Analyze_Unchecked_Expression (N : Node_Id) is
4410 Analyze (Expression (N), Suppress => All_Checks);
4411 Set_Etype (N, Etype (Expression (N)));
4412 Save_Interps (Expression (N), N);
4413 end Analyze_Unchecked_Expression;
4415 ---------------------------------------
4416 -- Analyze_Unchecked_Type_Conversion --
4417 ---------------------------------------
4419 procedure Analyze_Unchecked_Type_Conversion (N : Node_Id) is
4421 Find_Type (Subtype_Mark (N));
4422 Analyze_Expression (Expression (N));
4423 Set_Etype (N, Entity (Subtype_Mark (N)));
4424 end Analyze_Unchecked_Type_Conversion;
4426 ------------------------------------
4427 -- Analyze_User_Defined_Binary_Op --
4428 ------------------------------------
4430 procedure Analyze_User_Defined_Binary_Op
4435 -- Only do analysis if the operator Comes_From_Source, since otherwise
4436 -- the operator was generated by the expander, and all such operators
4437 -- always refer to the operators in package Standard.
4439 if Comes_From_Source (N) then
4441 F1 : constant Entity_Id := First_Formal (Op_Id);
4442 F2 : constant Entity_Id := Next_Formal (F1);
4445 -- Verify that Op_Id is a visible binary function. Note that since
4446 -- we know Op_Id is overloaded, potentially use visible means use
4447 -- visible for sure (RM 9.4(11)).
4449 if Ekind (Op_Id) = E_Function
4450 and then Present (F2)
4451 and then (Is_Immediately_Visible (Op_Id)
4452 or else Is_Potentially_Use_Visible (Op_Id))
4453 and then Has_Compatible_Type (Left_Opnd (N), Etype (F1))
4454 and then Has_Compatible_Type (Right_Opnd (N), Etype (F2))
4456 Add_One_Interp (N, Op_Id, Etype (Op_Id));
4458 -- If the left operand is overloaded, indicate that the
4459 -- current type is a viable candidate. This is redundant
4460 -- in most cases, but for equality and comparison operators
4461 -- where the context does not impose a type on the operands,
4462 -- setting the proper type is necessary to avoid subsequent
4463 -- ambiguities during resolution, when both user-defined and
4464 -- predefined operators may be candidates.
4466 if Is_Overloaded (Left_Opnd (N)) then
4467 Set_Etype (Left_Opnd (N), Etype (F1));
4470 if Debug_Flag_E then
4471 Write_Str ("user defined operator ");
4472 Write_Name (Chars (Op_Id));
4473 Write_Str (" on node ");
4474 Write_Int (Int (N));
4480 end Analyze_User_Defined_Binary_Op;
4482 -----------------------------------
4483 -- Analyze_User_Defined_Unary_Op --
4484 -----------------------------------
4486 procedure Analyze_User_Defined_Unary_Op
4491 -- Only do analysis if the operator Comes_From_Source, since otherwise
4492 -- the operator was generated by the expander, and all such operators
4493 -- always refer to the operators in package Standard.
4495 if Comes_From_Source (N) then
4497 F : constant Entity_Id := First_Formal (Op_Id);
4500 -- Verify that Op_Id is a visible unary function. Note that since
4501 -- we know Op_Id is overloaded, potentially use visible means use
4502 -- visible for sure (RM 9.4(11)).
4504 if Ekind (Op_Id) = E_Function
4505 and then No (Next_Formal (F))
4506 and then (Is_Immediately_Visible (Op_Id)
4507 or else Is_Potentially_Use_Visible (Op_Id))
4508 and then Has_Compatible_Type (Right_Opnd (N), Etype (F))
4510 Add_One_Interp (N, Op_Id, Etype (Op_Id));
4514 end Analyze_User_Defined_Unary_Op;
4516 ---------------------------
4517 -- Check_Arithmetic_Pair --
4518 ---------------------------
4520 procedure Check_Arithmetic_Pair
4521 (T1, T2 : Entity_Id;
4525 Op_Name : constant Name_Id := Chars (Op_Id);
4527 function Has_Fixed_Op (Typ : Entity_Id; Op : Entity_Id) return Boolean;
4528 -- Check whether the fixed-point type Typ has a user-defined operator
4529 -- (multiplication or division) that should hide the corresponding
4530 -- predefined operator. Used to implement Ada 2005 AI-264, to make
4531 -- such operators more visible and therefore useful.
4533 -- If the name of the operation is an expanded name with prefix
4534 -- Standard, the predefined universal fixed operator is available,
4535 -- as specified by AI-420 (RM 4.5.5 (19.1/2)).
4537 function Specific_Type (T1, T2 : Entity_Id) return Entity_Id;
4538 -- Get specific type (i.e. non-universal type if there is one)
4544 function Has_Fixed_Op (Typ : Entity_Id; Op : Entity_Id) return Boolean is
4545 Bas : constant Entity_Id := Base_Type (Typ);
4551 -- If the universal_fixed operation is given explicitly the rule
4552 -- concerning primitive operations of the type do not apply.
4554 if Nkind (N) = N_Function_Call
4555 and then Nkind (Name (N)) = N_Expanded_Name
4556 and then Entity (Prefix (Name (N))) = Standard_Standard
4561 -- The operation is treated as primitive if it is declared in the
4562 -- same scope as the type, and therefore on the same entity chain.
4564 Ent := Next_Entity (Typ);
4565 while Present (Ent) loop
4566 if Chars (Ent) = Chars (Op) then
4567 F1 := First_Formal (Ent);
4568 F2 := Next_Formal (F1);
4570 -- The operation counts as primitive if either operand or
4571 -- result are of the given base type, and both operands are
4572 -- fixed point types.
4574 if (Base_Type (Etype (F1)) = Bas
4575 and then Is_Fixed_Point_Type (Etype (F2)))
4578 (Base_Type (Etype (F2)) = Bas
4579 and then Is_Fixed_Point_Type (Etype (F1)))
4582 (Base_Type (Etype (Ent)) = Bas
4583 and then Is_Fixed_Point_Type (Etype (F1))
4584 and then Is_Fixed_Point_Type (Etype (F2)))
4600 function Specific_Type (T1, T2 : Entity_Id) return Entity_Id is
4602 if T1 = Universal_Integer or else T1 = Universal_Real then
4603 return Base_Type (T2);
4605 return Base_Type (T1);
4609 -- Start of processing for Check_Arithmetic_Pair
4612 if Op_Name = Name_Op_Add or else Op_Name = Name_Op_Subtract then
4614 if Is_Numeric_Type (T1)
4615 and then Is_Numeric_Type (T2)
4616 and then (Covers (T1 => T1, T2 => T2)
4618 Covers (T1 => T2, T2 => T1))
4620 Add_One_Interp (N, Op_Id, Specific_Type (T1, T2));
4623 elsif Op_Name = Name_Op_Multiply or else Op_Name = Name_Op_Divide then
4625 if Is_Fixed_Point_Type (T1)
4626 and then (Is_Fixed_Point_Type (T2)
4627 or else T2 = Universal_Real)
4629 -- If Treat_Fixed_As_Integer is set then the Etype is already set
4630 -- and no further processing is required (this is the case of an
4631 -- operator constructed by Exp_Fixd for a fixed point operation)
4632 -- Otherwise add one interpretation with universal fixed result
4633 -- If the operator is given in functional notation, it comes
4634 -- from source and Fixed_As_Integer cannot apply.
4636 if (Nkind (N) not in N_Op
4637 or else not Treat_Fixed_As_Integer (N))
4639 (not Has_Fixed_Op (T1, Op_Id)
4640 or else Nkind (Parent (N)) = N_Type_Conversion)
4642 Add_One_Interp (N, Op_Id, Universal_Fixed);
4645 elsif Is_Fixed_Point_Type (T2)
4646 and then (Nkind (N) not in N_Op
4647 or else not Treat_Fixed_As_Integer (N))
4648 and then T1 = Universal_Real
4650 (not Has_Fixed_Op (T1, Op_Id)
4651 or else Nkind (Parent (N)) = N_Type_Conversion)
4653 Add_One_Interp (N, Op_Id, Universal_Fixed);
4655 elsif Is_Numeric_Type (T1)
4656 and then Is_Numeric_Type (T2)
4657 and then (Covers (T1 => T1, T2 => T2)
4659 Covers (T1 => T2, T2 => T1))
4661 Add_One_Interp (N, Op_Id, Specific_Type (T1, T2));
4663 elsif Is_Fixed_Point_Type (T1)
4664 and then (Base_Type (T2) = Base_Type (Standard_Integer)
4665 or else T2 = Universal_Integer)
4667 Add_One_Interp (N, Op_Id, T1);
4669 elsif T2 = Universal_Real
4670 and then Base_Type (T1) = Base_Type (Standard_Integer)
4671 and then Op_Name = Name_Op_Multiply
4673 Add_One_Interp (N, Op_Id, Any_Fixed);
4675 elsif T1 = Universal_Real
4676 and then Base_Type (T2) = Base_Type (Standard_Integer)
4678 Add_One_Interp (N, Op_Id, Any_Fixed);
4680 elsif Is_Fixed_Point_Type (T2)
4681 and then (Base_Type (T1) = Base_Type (Standard_Integer)
4682 or else T1 = Universal_Integer)
4683 and then Op_Name = Name_Op_Multiply
4685 Add_One_Interp (N, Op_Id, T2);
4687 elsif T1 = Universal_Real and then T2 = Universal_Integer then
4688 Add_One_Interp (N, Op_Id, T1);
4690 elsif T2 = Universal_Real
4691 and then T1 = Universal_Integer
4692 and then Op_Name = Name_Op_Multiply
4694 Add_One_Interp (N, Op_Id, T2);
4697 elsif Op_Name = Name_Op_Mod or else Op_Name = Name_Op_Rem then
4699 -- Note: The fixed-point operands case with Treat_Fixed_As_Integer
4700 -- set does not require any special processing, since the Etype is
4701 -- already set (case of operation constructed by Exp_Fixed).
4703 if Is_Integer_Type (T1)
4704 and then (Covers (T1 => T1, T2 => T2)
4706 Covers (T1 => T2, T2 => T1))
4708 Add_One_Interp (N, Op_Id, Specific_Type (T1, T2));
4711 elsif Op_Name = Name_Op_Expon then
4712 if Is_Numeric_Type (T1)
4713 and then not Is_Fixed_Point_Type (T1)
4714 and then (Base_Type (T2) = Base_Type (Standard_Integer)
4715 or else T2 = Universal_Integer)
4717 Add_One_Interp (N, Op_Id, Base_Type (T1));
4720 else pragma Assert (Nkind (N) in N_Op_Shift);
4722 -- If not one of the predefined operators, the node may be one
4723 -- of the intrinsic functions. Its kind is always specific, and
4724 -- we can use it directly, rather than the name of the operation.
4726 if Is_Integer_Type (T1)
4727 and then (Base_Type (T2) = Base_Type (Standard_Integer)
4728 or else T2 = Universal_Integer)
4730 Add_One_Interp (N, Op_Id, Base_Type (T1));
4733 end Check_Arithmetic_Pair;
4735 -------------------------------
4736 -- Check_Misspelled_Selector --
4737 -------------------------------
4739 procedure Check_Misspelled_Selector
4740 (Prefix : Entity_Id;
4743 Max_Suggestions : constant := 2;
4744 Nr_Of_Suggestions : Natural := 0;
4746 Suggestion_1 : Entity_Id := Empty;
4747 Suggestion_2 : Entity_Id := Empty;
4752 -- All the components of the prefix of selector Sel are matched
4753 -- against Sel and a count is maintained of possible misspellings.
4754 -- When at the end of the analysis there are one or two (not more!)
4755 -- possible misspellings, these misspellings will be suggested as
4756 -- possible correction.
4758 if not (Is_Private_Type (Prefix) or else Is_Record_Type (Prefix)) then
4760 -- Concurrent types should be handled as well ???
4765 Comp := First_Entity (Prefix);
4766 while Nr_Of_Suggestions <= Max_Suggestions and then Present (Comp) loop
4767 if Is_Visible_Component (Comp) then
4768 if Is_Bad_Spelling_Of (Chars (Comp), Chars (Sel)) then
4769 Nr_Of_Suggestions := Nr_Of_Suggestions + 1;
4771 case Nr_Of_Suggestions is
4772 when 1 => Suggestion_1 := Comp;
4773 when 2 => Suggestion_2 := Comp;
4774 when others => exit;
4779 Comp := Next_Entity (Comp);
4782 -- Report at most two suggestions
4784 if Nr_Of_Suggestions = 1 then
4785 Error_Msg_NE -- CODEFIX
4786 ("\possible misspelling of&", Sel, Suggestion_1);
4788 elsif Nr_Of_Suggestions = 2 then
4789 Error_Msg_Node_2 := Suggestion_2;
4790 Error_Msg_NE -- CODEFIX
4791 ("\possible misspelling of& or&", Sel, Suggestion_1);
4793 end Check_Misspelled_Selector;
4795 ----------------------
4796 -- Defined_In_Scope --
4797 ----------------------
4799 function Defined_In_Scope (T : Entity_Id; S : Entity_Id) return Boolean
4801 S1 : constant Entity_Id := Scope (Base_Type (T));
4804 or else (S1 = System_Aux_Id and then S = Scope (S1));
4805 end Defined_In_Scope;
4811 procedure Diagnose_Call (N : Node_Id; Nam : Node_Id) is
4817 Void_Interp_Seen : Boolean := False;
4820 pragma Warnings (Off, Boolean);
4823 if Ada_Version >= Ada_2005 then
4824 Actual := First_Actual (N);
4825 while Present (Actual) loop
4827 -- Ada 2005 (AI-50217): Post an error in case of premature
4828 -- usage of an entity from the limited view.
4830 if not Analyzed (Etype (Actual))
4831 and then From_With_Type (Etype (Actual))
4833 Error_Msg_Qual_Level := 1;
4835 ("missing with_clause for scope of imported type&",
4836 Actual, Etype (Actual));
4837 Error_Msg_Qual_Level := 0;
4840 Next_Actual (Actual);
4844 -- Analyze each candidate call again, with full error reporting
4848 ("no candidate interpretations match the actuals:!", Nam);
4849 Err_Mode := All_Errors_Mode;
4850 All_Errors_Mode := True;
4852 -- If this is a call to an operation of a concurrent type,
4853 -- the failed interpretations have been removed from the
4854 -- name. Recover them to provide full diagnostics.
4856 if Nkind (Parent (Nam)) = N_Selected_Component then
4857 Set_Entity (Nam, Empty);
4858 New_Nam := New_Copy_Tree (Parent (Nam));
4859 Set_Is_Overloaded (New_Nam, False);
4860 Set_Is_Overloaded (Selector_Name (New_Nam), False);
4861 Set_Parent (New_Nam, Parent (Parent (Nam)));
4862 Analyze_Selected_Component (New_Nam);
4863 Get_First_Interp (Selector_Name (New_Nam), X, It);
4865 Get_First_Interp (Nam, X, It);
4868 while Present (It.Nam) loop
4869 if Etype (It.Nam) = Standard_Void_Type then
4870 Void_Interp_Seen := True;
4873 Analyze_One_Call (N, It.Nam, True, Success);
4874 Get_Next_Interp (X, It);
4877 if Nkind (N) = N_Function_Call then
4878 Get_First_Interp (Nam, X, It);
4879 while Present (It.Nam) loop
4880 if Ekind_In (It.Nam, E_Function, E_Operator) then
4883 Get_Next_Interp (X, It);
4887 -- If all interpretations are procedures, this deserves a
4888 -- more precise message. Ditto if this appears as the prefix
4889 -- of a selected component, which may be a lexical error.
4892 ("\context requires function call, found procedure name", Nam);
4894 if Nkind (Parent (N)) = N_Selected_Component
4895 and then N = Prefix (Parent (N))
4897 Error_Msg_N -- CODEFIX
4898 ("\period should probably be semicolon", Parent (N));
4901 elsif Nkind (N) = N_Procedure_Call_Statement
4902 and then not Void_Interp_Seen
4905 "\function name found in procedure call", Nam);
4908 All_Errors_Mode := Err_Mode;
4911 ---------------------------
4912 -- Find_Arithmetic_Types --
4913 ---------------------------
4915 procedure Find_Arithmetic_Types
4920 Index1 : Interp_Index;
4921 Index2 : Interp_Index;
4925 procedure Check_Right_Argument (T : Entity_Id);
4926 -- Check right operand of operator
4928 --------------------------
4929 -- Check_Right_Argument --
4930 --------------------------
4932 procedure Check_Right_Argument (T : Entity_Id) is
4934 if not Is_Overloaded (R) then
4935 Check_Arithmetic_Pair (T, Etype (R), Op_Id, N);
4937 Get_First_Interp (R, Index2, It2);
4938 while Present (It2.Typ) loop
4939 Check_Arithmetic_Pair (T, It2.Typ, Op_Id, N);
4940 Get_Next_Interp (Index2, It2);
4943 end Check_Right_Argument;
4945 -- Start of processing for Find_Arithmetic_Types
4948 if not Is_Overloaded (L) then
4949 Check_Right_Argument (Etype (L));
4952 Get_First_Interp (L, Index1, It1);
4953 while Present (It1.Typ) loop
4954 Check_Right_Argument (It1.Typ);
4955 Get_Next_Interp (Index1, It1);
4959 end Find_Arithmetic_Types;
4961 ------------------------
4962 -- Find_Boolean_Types --
4963 ------------------------
4965 procedure Find_Boolean_Types
4970 Index : Interp_Index;
4973 procedure Check_Numeric_Argument (T : Entity_Id);
4974 -- Special case for logical operations one of whose operands is an
4975 -- integer literal. If both are literal the result is any modular type.
4977 ----------------------------
4978 -- Check_Numeric_Argument --
4979 ----------------------------
4981 procedure Check_Numeric_Argument (T : Entity_Id) is
4983 if T = Universal_Integer then
4984 Add_One_Interp (N, Op_Id, Any_Modular);
4986 elsif Is_Modular_Integer_Type (T) then
4987 Add_One_Interp (N, Op_Id, T);
4989 end Check_Numeric_Argument;
4991 -- Start of processing for Find_Boolean_Types
4994 if not Is_Overloaded (L) then
4995 if Etype (L) = Universal_Integer
4996 or else Etype (L) = Any_Modular
4998 if not Is_Overloaded (R) then
4999 Check_Numeric_Argument (Etype (R));
5002 Get_First_Interp (R, Index, It);
5003 while Present (It.Typ) loop
5004 Check_Numeric_Argument (It.Typ);
5005 Get_Next_Interp (Index, It);
5009 -- If operands are aggregates, we must assume that they may be
5010 -- boolean arrays, and leave disambiguation for the second pass.
5011 -- If only one is an aggregate, verify that the other one has an
5012 -- interpretation as a boolean array
5014 elsif Nkind (L) = N_Aggregate then
5015 if Nkind (R) = N_Aggregate then
5016 Add_One_Interp (N, Op_Id, Etype (L));
5018 elsif not Is_Overloaded (R) then
5019 if Valid_Boolean_Arg (Etype (R)) then
5020 Add_One_Interp (N, Op_Id, Etype (R));
5024 Get_First_Interp (R, Index, It);
5025 while Present (It.Typ) loop
5026 if Valid_Boolean_Arg (It.Typ) then
5027 Add_One_Interp (N, Op_Id, It.Typ);
5030 Get_Next_Interp (Index, It);
5034 elsif Valid_Boolean_Arg (Etype (L))
5035 and then Has_Compatible_Type (R, Etype (L))
5037 Add_One_Interp (N, Op_Id, Etype (L));
5041 Get_First_Interp (L, Index, It);
5042 while Present (It.Typ) loop
5043 if Valid_Boolean_Arg (It.Typ)
5044 and then Has_Compatible_Type (R, It.Typ)
5046 Add_One_Interp (N, Op_Id, It.Typ);
5049 Get_Next_Interp (Index, It);
5052 end Find_Boolean_Types;
5054 ---------------------------
5055 -- Find_Comparison_Types --
5056 ---------------------------
5058 procedure Find_Comparison_Types
5063 Index : Interp_Index;
5065 Found : Boolean := False;
5068 Scop : Entity_Id := Empty;
5070 procedure Try_One_Interp (T1 : Entity_Id);
5071 -- Routine to try one proposed interpretation. Note that the context
5072 -- of the operator plays no role in resolving the arguments, so that
5073 -- if there is more than one interpretation of the operands that is
5074 -- compatible with comparison, the operation is ambiguous.
5076 --------------------
5077 -- Try_One_Interp --
5078 --------------------
5080 procedure Try_One_Interp (T1 : Entity_Id) is
5083 -- If the operator is an expanded name, then the type of the operand
5084 -- must be defined in the corresponding scope. If the type is
5085 -- universal, the context will impose the correct type.
5088 and then not Defined_In_Scope (T1, Scop)
5089 and then T1 /= Universal_Integer
5090 and then T1 /= Universal_Real
5091 and then T1 /= Any_String
5092 and then T1 /= Any_Composite
5097 if Valid_Comparison_Arg (T1)
5098 and then Has_Compatible_Type (R, T1)
5101 and then Base_Type (T1) /= Base_Type (T_F)
5103 It := Disambiguate (L, I_F, Index, Any_Type);
5105 if It = No_Interp then
5106 Ambiguous_Operands (N);
5107 Set_Etype (L, Any_Type);
5121 Find_Non_Universal_Interpretations (N, R, Op_Id, T1);
5126 -- Start of processing for Find_Comparison_Types
5129 -- If left operand is aggregate, the right operand has to
5130 -- provide a usable type for it.
5132 if Nkind (L) = N_Aggregate
5133 and then Nkind (R) /= N_Aggregate
5135 Find_Comparison_Types (L => R, R => L, Op_Id => Op_Id, N => N);
5139 if Nkind (N) = N_Function_Call
5140 and then Nkind (Name (N)) = N_Expanded_Name
5142 Scop := Entity (Prefix (Name (N)));
5144 -- The prefix may be a package renaming, and the subsequent test
5145 -- requires the original package.
5147 if Ekind (Scop) = E_Package
5148 and then Present (Renamed_Entity (Scop))
5150 Scop := Renamed_Entity (Scop);
5151 Set_Entity (Prefix (Name (N)), Scop);
5155 if not Is_Overloaded (L) then
5156 Try_One_Interp (Etype (L));
5159 Get_First_Interp (L, Index, It);
5160 while Present (It.Typ) loop
5161 Try_One_Interp (It.Typ);
5162 Get_Next_Interp (Index, It);
5165 end Find_Comparison_Types;
5167 ----------------------------------------
5168 -- Find_Non_Universal_Interpretations --
5169 ----------------------------------------
5171 procedure Find_Non_Universal_Interpretations
5177 Index : Interp_Index;
5181 if T1 = Universal_Integer
5182 or else T1 = Universal_Real
5184 if not Is_Overloaded (R) then
5186 (N, Op_Id, Standard_Boolean, Base_Type (Etype (R)));
5188 Get_First_Interp (R, Index, It);
5189 while Present (It.Typ) loop
5190 if Covers (It.Typ, T1) then
5192 (N, Op_Id, Standard_Boolean, Base_Type (It.Typ));
5195 Get_Next_Interp (Index, It);
5199 Add_One_Interp (N, Op_Id, Standard_Boolean, Base_Type (T1));
5201 end Find_Non_Universal_Interpretations;
5203 ------------------------------
5204 -- Find_Concatenation_Types --
5205 ------------------------------
5207 procedure Find_Concatenation_Types
5212 Op_Type : constant Entity_Id := Etype (Op_Id);
5215 if Is_Array_Type (Op_Type)
5216 and then not Is_Limited_Type (Op_Type)
5218 and then (Has_Compatible_Type (L, Op_Type)
5220 Has_Compatible_Type (L, Component_Type (Op_Type)))
5222 and then (Has_Compatible_Type (R, Op_Type)
5224 Has_Compatible_Type (R, Component_Type (Op_Type)))
5226 Add_One_Interp (N, Op_Id, Op_Type);
5228 end Find_Concatenation_Types;
5230 -------------------------
5231 -- Find_Equality_Types --
5232 -------------------------
5234 procedure Find_Equality_Types
5239 Index : Interp_Index;
5241 Found : Boolean := False;
5244 Scop : Entity_Id := Empty;
5246 procedure Try_One_Interp (T1 : Entity_Id);
5247 -- The context of the equality operator plays no role in resolving the
5248 -- arguments, so that if there is more than one interpretation of the
5249 -- operands that is compatible with equality, the construct is ambiguous
5250 -- and an error can be emitted now, after trying to disambiguate, i.e.
5251 -- applying preference rules.
5253 --------------------
5254 -- Try_One_Interp --
5255 --------------------
5257 procedure Try_One_Interp (T1 : Entity_Id) is
5258 Bas : constant Entity_Id := Base_Type (T1);
5261 -- If the operator is an expanded name, then the type of the operand
5262 -- must be defined in the corresponding scope. If the type is
5263 -- universal, the context will impose the correct type. An anonymous
5264 -- type for a 'Access reference is also universal in this sense, as
5265 -- the actual type is obtained from context.
5266 -- In Ada 2005, the equality operator for anonymous access types
5267 -- is declared in Standard, and preference rules apply to it.
5269 if Present (Scop) then
5270 if Defined_In_Scope (T1, Scop)
5271 or else T1 = Universal_Integer
5272 or else T1 = Universal_Real
5273 or else T1 = Any_Access
5274 or else T1 = Any_String
5275 or else T1 = Any_Composite
5276 or else (Ekind (T1) = E_Access_Subprogram_Type
5277 and then not Comes_From_Source (T1))
5281 elsif Ekind (T1) = E_Anonymous_Access_Type
5282 and then Scop = Standard_Standard
5287 -- The scope does not contain an operator for the type
5292 -- If we have infix notation, the operator must be usable.
5293 -- Within an instance, if the type is already established we
5294 -- know it is correct.
5295 -- In Ada 2005, the equality on anonymous access types is declared
5296 -- in Standard, and is always visible.
5298 elsif In_Open_Scopes (Scope (Bas))
5299 or else Is_Potentially_Use_Visible (Bas)
5300 or else In_Use (Bas)
5301 or else (In_Use (Scope (Bas))
5302 and then not Is_Hidden (Bas))
5303 or else (In_Instance
5304 and then First_Subtype (T1) = First_Subtype (Etype (R)))
5305 or else Ekind (T1) = E_Anonymous_Access_Type
5310 -- Save candidate type for subsequent error message, if any
5312 if not Is_Limited_Type (T1) then
5313 Candidate_Type := T1;
5319 -- Ada 2005 (AI-230): Keep restriction imposed by Ada 83 and 95:
5320 -- Do not allow anonymous access types in equality operators.
5322 if Ada_Version < Ada_2005
5323 and then Ekind (T1) = E_Anonymous_Access_Type
5328 if T1 /= Standard_Void_Type
5329 and then not Is_Limited_Type (T1)
5330 and then not Is_Limited_Composite (T1)
5331 and then Has_Compatible_Type (R, T1)
5334 and then Base_Type (T1) /= Base_Type (T_F)
5336 It := Disambiguate (L, I_F, Index, Any_Type);
5338 if It = No_Interp then
5339 Ambiguous_Operands (N);
5340 Set_Etype (L, Any_Type);
5353 if not Analyzed (L) then
5357 Find_Non_Universal_Interpretations (N, R, Op_Id, T1);
5359 -- Case of operator was not visible, Etype still set to Any_Type
5361 if Etype (N) = Any_Type then
5365 elsif Scop = Standard_Standard
5366 and then Ekind (T1) = E_Anonymous_Access_Type
5372 -- Start of processing for Find_Equality_Types
5375 -- If left operand is aggregate, the right operand has to
5376 -- provide a usable type for it.
5378 if Nkind (L) = N_Aggregate
5379 and then Nkind (R) /= N_Aggregate
5381 Find_Equality_Types (L => R, R => L, Op_Id => Op_Id, N => N);
5385 if Nkind (N) = N_Function_Call
5386 and then Nkind (Name (N)) = N_Expanded_Name
5388 Scop := Entity (Prefix (Name (N)));
5390 -- The prefix may be a package renaming, and the subsequent test
5391 -- requires the original package.
5393 if Ekind (Scop) = E_Package
5394 and then Present (Renamed_Entity (Scop))
5396 Scop := Renamed_Entity (Scop);
5397 Set_Entity (Prefix (Name (N)), Scop);
5401 if not Is_Overloaded (L) then
5402 Try_One_Interp (Etype (L));
5405 Get_First_Interp (L, Index, It);
5406 while Present (It.Typ) loop
5407 Try_One_Interp (It.Typ);
5408 Get_Next_Interp (Index, It);
5411 end Find_Equality_Types;
5413 -------------------------
5414 -- Find_Negation_Types --
5415 -------------------------
5417 procedure Find_Negation_Types
5422 Index : Interp_Index;
5426 if not Is_Overloaded (R) then
5427 if Etype (R) = Universal_Integer then
5428 Add_One_Interp (N, Op_Id, Any_Modular);
5429 elsif Valid_Boolean_Arg (Etype (R)) then
5430 Add_One_Interp (N, Op_Id, Etype (R));
5434 Get_First_Interp (R, Index, It);
5435 while Present (It.Typ) loop
5436 if Valid_Boolean_Arg (It.Typ) then
5437 Add_One_Interp (N, Op_Id, It.Typ);
5440 Get_Next_Interp (Index, It);
5443 end Find_Negation_Types;
5445 ------------------------------
5446 -- Find_Primitive_Operation --
5447 ------------------------------
5449 function Find_Primitive_Operation (N : Node_Id) return Boolean is
5450 Obj : constant Node_Id := Prefix (N);
5451 Op : constant Node_Id := Selector_Name (N);
5458 Set_Etype (Op, Any_Type);
5460 if Is_Access_Type (Etype (Obj)) then
5461 Typ := Designated_Type (Etype (Obj));
5466 if Is_Class_Wide_Type (Typ) then
5467 Typ := Root_Type (Typ);
5470 Prims := Primitive_Operations (Typ);
5472 Prim := First_Elmt (Prims);
5473 while Present (Prim) loop
5474 if Chars (Node (Prim)) = Chars (Op) then
5475 Add_One_Interp (Op, Node (Prim), Etype (Node (Prim)));
5476 Set_Etype (N, Etype (Node (Prim)));
5482 -- Now look for class-wide operations of the type or any of its
5483 -- ancestors by iterating over the homonyms of the selector.
5486 Cls_Type : constant Entity_Id := Class_Wide_Type (Typ);
5490 Hom := Current_Entity (Op);
5491 while Present (Hom) loop
5492 if (Ekind (Hom) = E_Procedure
5494 Ekind (Hom) = E_Function)
5495 and then Scope (Hom) = Scope (Typ)
5496 and then Present (First_Formal (Hom))
5498 (Base_Type (Etype (First_Formal (Hom))) = Cls_Type
5500 (Is_Access_Type (Etype (First_Formal (Hom)))
5502 Ekind (Etype (First_Formal (Hom))) =
5503 E_Anonymous_Access_Type
5506 (Designated_Type (Etype (First_Formal (Hom)))) =
5509 Add_One_Interp (Op, Hom, Etype (Hom));
5510 Set_Etype (N, Etype (Hom));
5513 Hom := Homonym (Hom);
5517 return Etype (Op) /= Any_Type;
5518 end Find_Primitive_Operation;
5520 ----------------------
5521 -- Find_Unary_Types --
5522 ----------------------
5524 procedure Find_Unary_Types
5529 Index : Interp_Index;
5533 if not Is_Overloaded (R) then
5534 if Is_Numeric_Type (Etype (R)) then
5535 Add_One_Interp (N, Op_Id, Base_Type (Etype (R)));
5539 Get_First_Interp (R, Index, It);
5540 while Present (It.Typ) loop
5541 if Is_Numeric_Type (It.Typ) then
5542 Add_One_Interp (N, Op_Id, Base_Type (It.Typ));
5545 Get_Next_Interp (Index, It);
5548 end Find_Unary_Types;
5554 function Junk_Operand (N : Node_Id) return Boolean is
5558 if Error_Posted (N) then
5562 -- Get entity to be tested
5564 if Is_Entity_Name (N)
5565 and then Present (Entity (N))
5569 -- An odd case, a procedure name gets converted to a very peculiar
5570 -- function call, and here is where we detect this happening.
5572 elsif Nkind (N) = N_Function_Call
5573 and then Is_Entity_Name (Name (N))
5574 and then Present (Entity (Name (N)))
5578 -- Another odd case, there are at least some cases of selected
5579 -- components where the selected component is not marked as having
5580 -- an entity, even though the selector does have an entity
5582 elsif Nkind (N) = N_Selected_Component
5583 and then Present (Entity (Selector_Name (N)))
5585 Enode := Selector_Name (N);
5591 -- Now test the entity we got to see if it is a bad case
5593 case Ekind (Entity (Enode)) is
5597 ("package name cannot be used as operand", Enode);
5599 when Generic_Unit_Kind =>
5601 ("generic unit name cannot be used as operand", Enode);
5605 ("subtype name cannot be used as operand", Enode);
5609 ("entry name cannot be used as operand", Enode);
5613 ("procedure name cannot be used as operand", Enode);
5617 ("exception name cannot be used as operand", Enode);
5619 when E_Block | E_Label | E_Loop =>
5621 ("label name cannot be used as operand", Enode);
5631 --------------------
5632 -- Operator_Check --
5633 --------------------
5635 procedure Operator_Check (N : Node_Id) is
5637 Remove_Abstract_Operations (N);
5639 -- Test for case of no interpretation found for operator
5641 if Etype (N) = Any_Type then
5645 Op_Id : Entity_Id := Empty;
5648 R := Right_Opnd (N);
5650 if Nkind (N) in N_Binary_Op then
5656 -- If either operand has no type, then don't complain further,
5657 -- since this simply means that we have a propagated error.
5660 or else Etype (R) = Any_Type
5661 or else (Nkind (N) in N_Binary_Op and then Etype (L) = Any_Type)
5665 -- We explicitly check for the case of concatenation of component
5666 -- with component to avoid reporting spurious matching array types
5667 -- that might happen to be lurking in distant packages (such as
5668 -- run-time packages). This also prevents inconsistencies in the
5669 -- messages for certain ACVC B tests, which can vary depending on
5670 -- types declared in run-time interfaces. Another improvement when
5671 -- aggregates are present is to look for a well-typed operand.
5673 elsif Present (Candidate_Type)
5674 and then (Nkind (N) /= N_Op_Concat
5675 or else Is_Array_Type (Etype (L))
5676 or else Is_Array_Type (Etype (R)))
5678 if Nkind (N) = N_Op_Concat then
5679 if Etype (L) /= Any_Composite
5680 and then Is_Array_Type (Etype (L))
5682 Candidate_Type := Etype (L);
5684 elsif Etype (R) /= Any_Composite
5685 and then Is_Array_Type (Etype (R))
5687 Candidate_Type := Etype (R);
5691 Error_Msg_NE -- CODEFIX
5692 ("operator for} is not directly visible!",
5693 N, First_Subtype (Candidate_Type));
5696 U : constant Node_Id :=
5697 Cunit (Get_Source_Unit (Candidate_Type));
5699 if Unit_Is_Visible (U) then
5700 Error_Msg_N -- CODEFIX
5701 ("use clause would make operation legal!", N);
5703 Error_Msg_NE -- CODEFIX
5704 ("add with_clause and use_clause for&!",
5705 N, Defining_Entity (Unit (U)));
5710 -- If either operand is a junk operand (e.g. package name), then
5711 -- post appropriate error messages, but do not complain further.
5713 -- Note that the use of OR in this test instead of OR ELSE is
5714 -- quite deliberate, we may as well check both operands in the
5715 -- binary operator case.
5717 elsif Junk_Operand (R)
5718 or (Nkind (N) in N_Binary_Op and then Junk_Operand (L))
5722 -- If we have a logical operator, one of whose operands is
5723 -- Boolean, then we know that the other operand cannot resolve to
5724 -- Boolean (since we got no interpretations), but in that case we
5725 -- pretty much know that the other operand should be Boolean, so
5726 -- resolve it that way (generating an error)
5728 elsif Nkind_In (N, N_Op_And, N_Op_Or, N_Op_Xor) then
5729 if Etype (L) = Standard_Boolean then
5730 Resolve (R, Standard_Boolean);
5732 elsif Etype (R) = Standard_Boolean then
5733 Resolve (L, Standard_Boolean);
5737 -- For an arithmetic operator or comparison operator, if one
5738 -- of the operands is numeric, then we know the other operand
5739 -- is not the same numeric type. If it is a non-numeric type,
5740 -- then probably it is intended to match the other operand.
5742 elsif Nkind_In (N, N_Op_Add,
5748 Nkind_In (N, N_Op_Lt,
5754 if Is_Numeric_Type (Etype (L))
5755 and then not Is_Numeric_Type (Etype (R))
5757 Resolve (R, Etype (L));
5760 elsif Is_Numeric_Type (Etype (R))
5761 and then not Is_Numeric_Type (Etype (L))
5763 Resolve (L, Etype (R));
5767 -- Comparisons on A'Access are common enough to deserve a
5770 elsif Nkind_In (N, N_Op_Eq, N_Op_Ne)
5771 and then Ekind (Etype (L)) = E_Access_Attribute_Type
5772 and then Ekind (Etype (R)) = E_Access_Attribute_Type
5775 ("two access attributes cannot be compared directly", N);
5777 ("\use qualified expression for one of the operands",
5781 -- Another one for C programmers
5783 elsif Nkind (N) = N_Op_Concat
5784 and then Valid_Boolean_Arg (Etype (L))
5785 and then Valid_Boolean_Arg (Etype (R))
5787 Error_Msg_N ("invalid operands for concatenation", N);
5788 Error_Msg_N -- CODEFIX
5789 ("\maybe AND was meant", N);
5792 -- A special case for comparison of access parameter with null
5794 elsif Nkind (N) = N_Op_Eq
5795 and then Is_Entity_Name (L)
5796 and then Nkind (Parent (Entity (L))) = N_Parameter_Specification
5797 and then Nkind (Parameter_Type (Parent (Entity (L)))) =
5799 and then Nkind (R) = N_Null
5801 Error_Msg_N ("access parameter is not allowed to be null", L);
5802 Error_Msg_N ("\(call would raise Constraint_Error)", L);
5805 -- Another special case for exponentiation, where the right
5806 -- operand must be Natural, independently of the base.
5808 elsif Nkind (N) = N_Op_Expon
5809 and then Is_Numeric_Type (Etype (L))
5810 and then not Is_Overloaded (R)
5812 First_Subtype (Base_Type (Etype (R))) /= Standard_Integer
5813 and then Base_Type (Etype (R)) /= Universal_Integer
5816 ("exponent must be of type Natural, found}", R, Etype (R));
5820 -- If we fall through then just give general message. Note that in
5821 -- the following messages, if the operand is overloaded we choose
5822 -- an arbitrary type to complain about, but that is probably more
5823 -- useful than not giving a type at all.
5825 if Nkind (N) in N_Unary_Op then
5826 Error_Msg_Node_2 := Etype (R);
5827 Error_Msg_N ("operator& not defined for}", N);
5831 if Nkind (N) in N_Binary_Op then
5832 if not Is_Overloaded (L)
5833 and then not Is_Overloaded (R)
5834 and then Base_Type (Etype (L)) = Base_Type (Etype (R))
5836 Error_Msg_Node_2 := First_Subtype (Etype (R));
5837 Error_Msg_N ("there is no applicable operator& for}", N);
5840 -- Another attempt to find a fix: one of the candidate
5841 -- interpretations may not be use-visible. This has
5842 -- already been checked for predefined operators, so
5843 -- we examine only user-defined functions.
5845 Op_Id := Get_Name_Entity_Id (Chars (N));
5847 while Present (Op_Id) loop
5848 if Ekind (Op_Id) /= E_Operator
5849 and then Is_Overloadable (Op_Id)
5851 if not Is_Immediately_Visible (Op_Id)
5852 and then not In_Use (Scope (Op_Id))
5853 and then not Is_Abstract_Subprogram (Op_Id)
5854 and then not Is_Hidden (Op_Id)
5855 and then Ekind (Scope (Op_Id)) = E_Package
5858 (L, Etype (First_Formal (Op_Id)))
5860 (Next_Formal (First_Formal (Op_Id)))
5864 Etype (Next_Formal (First_Formal (Op_Id))))
5867 ("No legal interpretation for operator&", N);
5869 ("\use clause on& would make operation legal",
5875 Op_Id := Homonym (Op_Id);
5879 Error_Msg_N ("invalid operand types for operator&", N);
5881 if Nkind (N) /= N_Op_Concat then
5882 Error_Msg_NE ("\left operand has}!", N, Etype (L));
5883 Error_Msg_NE ("\right operand has}!", N, Etype (R));
5893 -----------------------------------------
5894 -- Process_Implicit_Dereference_Prefix --
5895 -----------------------------------------
5897 function Process_Implicit_Dereference_Prefix
5899 P : Entity_Id) return Entity_Id
5902 Typ : constant Entity_Id := Designated_Type (Etype (P));
5906 and then (Operating_Mode = Check_Semantics or else not Expander_Active)
5908 -- We create a dummy reference to E to ensure that the reference
5909 -- is not considered as part of an assignment (an implicit
5910 -- dereference can never assign to its prefix). The Comes_From_Source
5911 -- attribute needs to be propagated for accurate warnings.
5913 Ref := New_Reference_To (E, Sloc (P));
5914 Set_Comes_From_Source (Ref, Comes_From_Source (P));
5915 Generate_Reference (E, Ref);
5918 -- An implicit dereference is a legal occurrence of an
5919 -- incomplete type imported through a limited_with clause,
5920 -- if the full view is visible.
5922 if From_With_Type (Typ)
5923 and then not From_With_Type (Scope (Typ))
5925 (Is_Immediately_Visible (Scope (Typ))
5927 (Is_Child_Unit (Scope (Typ))
5928 and then Is_Visible_Child_Unit (Scope (Typ))))
5930 return Available_View (Typ);
5935 end Process_Implicit_Dereference_Prefix;
5937 --------------------------------
5938 -- Remove_Abstract_Operations --
5939 --------------------------------
5941 procedure Remove_Abstract_Operations (N : Node_Id) is
5942 Abstract_Op : Entity_Id := Empty;
5943 Address_Kludge : Boolean := False;
5947 -- AI-310: If overloaded, remove abstract non-dispatching operations. We
5948 -- activate this if either extensions are enabled, or if the abstract
5949 -- operation in question comes from a predefined file. This latter test
5950 -- allows us to use abstract to make operations invisible to users. In
5951 -- particular, if type Address is non-private and abstract subprograms
5952 -- are used to hide its operators, they will be truly hidden.
5954 type Operand_Position is (First_Op, Second_Op);
5955 Univ_Type : constant Entity_Id := Universal_Interpretation (N);
5957 procedure Remove_Address_Interpretations (Op : Operand_Position);
5958 -- Ambiguities may arise when the operands are literal and the address
5959 -- operations in s-auxdec are visible. In that case, remove the
5960 -- interpretation of a literal as Address, to retain the semantics of
5961 -- Address as a private type.
5963 ------------------------------------
5964 -- Remove_Address_Interpretations --
5965 ------------------------------------
5967 procedure Remove_Address_Interpretations (Op : Operand_Position) is
5971 if Is_Overloaded (N) then
5972 Get_First_Interp (N, I, It);
5973 while Present (It.Nam) loop
5974 Formal := First_Entity (It.Nam);
5976 if Op = Second_Op then
5977 Formal := Next_Entity (Formal);
5980 if Is_Descendent_Of_Address (Etype (Formal)) then
5981 Address_Kludge := True;
5985 Get_Next_Interp (I, It);
5988 end Remove_Address_Interpretations;
5990 -- Start of processing for Remove_Abstract_Operations
5993 if Is_Overloaded (N) then
5994 Get_First_Interp (N, I, It);
5996 while Present (It.Nam) loop
5997 if Is_Overloadable (It.Nam)
5998 and then Is_Abstract_Subprogram (It.Nam)
5999 and then not Is_Dispatching_Operation (It.Nam)
6001 Abstract_Op := It.Nam;
6003 if Is_Descendent_Of_Address (It.Typ) then
6004 Address_Kludge := True;
6008 -- In Ada 2005, this operation does not participate in Overload
6009 -- resolution. If the operation is defined in a predefined
6010 -- unit, it is one of the operations declared abstract in some
6011 -- variants of System, and it must be removed as well.
6013 elsif Ada_Version >= Ada_2005
6014 or else Is_Predefined_File_Name
6015 (Unit_File_Name (Get_Source_Unit (It.Nam)))
6022 Get_Next_Interp (I, It);
6025 if No (Abstract_Op) then
6027 -- If some interpretation yields an integer type, it is still
6028 -- possible that there are address interpretations. Remove them
6029 -- if one operand is a literal, to avoid spurious ambiguities
6030 -- on systems where Address is a visible integer type.
6032 if Is_Overloaded (N)
6033 and then Nkind (N) in N_Op
6034 and then Is_Integer_Type (Etype (N))
6036 if Nkind (N) in N_Binary_Op then
6037 if Nkind (Right_Opnd (N)) = N_Integer_Literal then
6038 Remove_Address_Interpretations (Second_Op);
6040 elsif Nkind (Right_Opnd (N)) = N_Integer_Literal then
6041 Remove_Address_Interpretations (First_Op);
6046 elsif Nkind (N) in N_Op then
6048 -- Remove interpretations that treat literals as addresses. This
6049 -- is never appropriate, even when Address is defined as a visible
6050 -- Integer type. The reason is that we would really prefer Address
6051 -- to behave as a private type, even in this case, which is there
6052 -- only to accommodate oddities of VMS address sizes. If Address
6053 -- is a visible integer type, we get lots of overload ambiguities.
6055 if Nkind (N) in N_Binary_Op then
6057 U1 : constant Boolean :=
6058 Present (Universal_Interpretation (Right_Opnd (N)));
6059 U2 : constant Boolean :=
6060 Present (Universal_Interpretation (Left_Opnd (N)));
6064 Remove_Address_Interpretations (Second_Op);
6068 Remove_Address_Interpretations (First_Op);
6071 if not (U1 and U2) then
6073 -- Remove corresponding predefined operator, which is
6074 -- always added to the overload set.
6076 Get_First_Interp (N, I, It);
6077 while Present (It.Nam) loop
6078 if Scope (It.Nam) = Standard_Standard
6079 and then Base_Type (It.Typ) =
6080 Base_Type (Etype (Abstract_Op))
6085 Get_Next_Interp (I, It);
6088 elsif Is_Overloaded (N)
6089 and then Present (Univ_Type)
6091 -- If both operands have a universal interpretation,
6092 -- it is still necessary to remove interpretations that
6093 -- yield Address. Any remaining ambiguities will be
6094 -- removed in Disambiguate.
6096 Get_First_Interp (N, I, It);
6097 while Present (It.Nam) loop
6098 if Is_Descendent_Of_Address (It.Typ) then
6101 elsif not Is_Type (It.Nam) then
6102 Set_Entity (N, It.Nam);
6105 Get_Next_Interp (I, It);
6111 elsif Nkind (N) = N_Function_Call
6113 (Nkind (Name (N)) = N_Operator_Symbol
6115 (Nkind (Name (N)) = N_Expanded_Name
6117 Nkind (Selector_Name (Name (N))) = N_Operator_Symbol))
6121 Arg1 : constant Node_Id := First (Parameter_Associations (N));
6122 U1 : constant Boolean :=
6123 Present (Universal_Interpretation (Arg1));
6124 U2 : constant Boolean :=
6125 Present (Next (Arg1)) and then
6126 Present (Universal_Interpretation (Next (Arg1)));
6130 Remove_Address_Interpretations (First_Op);
6134 Remove_Address_Interpretations (Second_Op);
6137 if not (U1 and U2) then
6138 Get_First_Interp (N, I, It);
6139 while Present (It.Nam) loop
6140 if Scope (It.Nam) = Standard_Standard
6141 and then It.Typ = Base_Type (Etype (Abstract_Op))
6146 Get_Next_Interp (I, It);
6152 -- If the removal has left no valid interpretations, emit an error
6153 -- message now and label node as illegal.
6155 if Present (Abstract_Op) then
6156 Get_First_Interp (N, I, It);
6160 -- Removal of abstract operation left no viable candidate
6162 Set_Etype (N, Any_Type);
6163 Error_Msg_Sloc := Sloc (Abstract_Op);
6165 ("cannot call abstract operation& declared#", N, Abstract_Op);
6167 -- In Ada 2005, an abstract operation may disable predefined
6168 -- operators. Since the context is not yet known, we mark the
6169 -- predefined operators as potentially hidden. Do not include
6170 -- predefined operators when addresses are involved since this
6171 -- case is handled separately.
6173 elsif Ada_Version >= Ada_2005
6174 and then not Address_Kludge
6176 while Present (It.Nam) loop
6177 if Is_Numeric_Type (It.Typ)
6178 and then Scope (It.Typ) = Standard_Standard
6180 Set_Abstract_Op (I, Abstract_Op);
6183 Get_Next_Interp (I, It);
6188 end Remove_Abstract_Operations;
6190 -----------------------
6191 -- Try_Indirect_Call --
6192 -----------------------
6194 function Try_Indirect_Call
6197 Typ : Entity_Id) return Boolean
6203 pragma Warnings (Off, Call_OK);
6206 Normalize_Actuals (N, Designated_Type (Typ), False, Call_OK);
6208 Actual := First_Actual (N);
6209 Formal := First_Formal (Designated_Type (Typ));
6210 while Present (Actual) and then Present (Formal) loop
6211 if not Has_Compatible_Type (Actual, Etype (Formal)) then
6216 Next_Formal (Formal);
6219 if No (Actual) and then No (Formal) then
6220 Add_One_Interp (N, Nam, Etype (Designated_Type (Typ)));
6222 -- Nam is a candidate interpretation for the name in the call,
6223 -- if it is not an indirect call.
6225 if not Is_Type (Nam)
6226 and then Is_Entity_Name (Name (N))
6228 Set_Entity (Name (N), Nam);
6235 end Try_Indirect_Call;
6237 ----------------------
6238 -- Try_Indexed_Call --
6239 ----------------------
6241 function Try_Indexed_Call
6245 Skip_First : Boolean) return Boolean
6247 Loc : constant Source_Ptr := Sloc (N);
6248 Actuals : constant List_Id := Parameter_Associations (N);
6253 Actual := First (Actuals);
6255 -- If the call was originally written in prefix form, skip the first
6256 -- actual, which is obviously not defaulted.
6262 Index := First_Index (Typ);
6263 while Present (Actual) and then Present (Index) loop
6265 -- If the parameter list has a named association, the expression
6266 -- is definitely a call and not an indexed component.
6268 if Nkind (Actual) = N_Parameter_Association then
6272 if Is_Entity_Name (Actual)
6273 and then Is_Type (Entity (Actual))
6274 and then No (Next (Actual))
6276 -- A single actual that is a type name indicates a slice if the
6277 -- type is discrete, and an error otherwise.
6279 if Is_Discrete_Type (Entity (Actual)) then
6283 Make_Function_Call (Loc,
6284 Name => Relocate_Node (Name (N))),
6286 New_Occurrence_Of (Entity (Actual), Sloc (Actual))));
6291 Error_Msg_N ("invalid use of type in expression", Actual);
6292 Set_Etype (N, Any_Type);
6297 elsif not Has_Compatible_Type (Actual, Etype (Index)) then
6305 if No (Actual) and then No (Index) then
6306 Add_One_Interp (N, Nam, Component_Type (Typ));
6308 -- Nam is a candidate interpretation for the name in the call,
6309 -- if it is not an indirect call.
6311 if not Is_Type (Nam)
6312 and then Is_Entity_Name (Name (N))
6314 Set_Entity (Name (N), Nam);
6321 end Try_Indexed_Call;
6323 --------------------------
6324 -- Try_Object_Operation --
6325 --------------------------
6327 function Try_Object_Operation (N : Node_Id) return Boolean is
6328 K : constant Node_Kind := Nkind (Parent (N));
6329 Is_Subprg_Call : constant Boolean := Nkind_In
6330 (K, N_Procedure_Call_Statement,
6332 Loc : constant Source_Ptr := Sloc (N);
6333 Obj : constant Node_Id := Prefix (N);
6335 Subprog : constant Node_Id :=
6336 Make_Identifier (Sloc (Selector_Name (N)),
6337 Chars => Chars (Selector_Name (N)));
6338 -- Identifier on which possible interpretations will be collected
6340 Report_Error : Boolean := False;
6341 -- If no candidate interpretation matches the context, redo the
6342 -- analysis with error enabled to provide additional information.
6345 Candidate : Entity_Id := Empty;
6346 New_Call_Node : Node_Id := Empty;
6347 Node_To_Replace : Node_Id;
6348 Obj_Type : Entity_Id := Etype (Obj);
6349 Success : Boolean := False;
6351 function Valid_Candidate
6354 Subp : Entity_Id) return Entity_Id;
6355 -- If the subprogram is a valid interpretation, record it, and add
6356 -- to the list of interpretations of Subprog.
6358 procedure Complete_Object_Operation
6359 (Call_Node : Node_Id;
6360 Node_To_Replace : Node_Id);
6361 -- Make Subprog the name of Call_Node, replace Node_To_Replace with
6362 -- Call_Node, insert the object (or its dereference) as the first actual
6363 -- in the call, and complete the analysis of the call.
6365 procedure Report_Ambiguity (Op : Entity_Id);
6366 -- If a prefixed procedure call is ambiguous, indicate whether the
6367 -- call includes an implicit dereference or an implicit 'Access.
6369 procedure Transform_Object_Operation
6370 (Call_Node : out Node_Id;
6371 Node_To_Replace : out Node_Id);
6372 -- Transform Obj.Operation (X, Y,,) into Operation (Obj, X, Y ..)
6373 -- Call_Node is the resulting subprogram call, Node_To_Replace is
6374 -- either N or the parent of N, and Subprog is a reference to the
6375 -- subprogram we are trying to match.
6377 function Try_Class_Wide_Operation
6378 (Call_Node : Node_Id;
6379 Node_To_Replace : Node_Id) return Boolean;
6380 -- Traverse all ancestor types looking for a class-wide subprogram
6381 -- for which the current operation is a valid non-dispatching call.
6383 procedure Try_One_Prefix_Interpretation (T : Entity_Id);
6384 -- If prefix is overloaded, its interpretation may include different
6385 -- tagged types, and we must examine the primitive operations and
6386 -- the class-wide operations of each in order to find candidate
6387 -- interpretations for the call as a whole.
6389 function Try_Primitive_Operation
6390 (Call_Node : Node_Id;
6391 Node_To_Replace : Node_Id) return Boolean;
6392 -- Traverse the list of primitive subprograms looking for a dispatching
6393 -- operation for which the current node is a valid call .
6395 ---------------------
6396 -- Valid_Candidate --
6397 ---------------------
6399 function Valid_Candidate
6402 Subp : Entity_Id) return Entity_Id
6404 Arr_Type : Entity_Id;
6405 Comp_Type : Entity_Id;
6408 -- If the subprogram is a valid interpretation, record it in global
6409 -- variable Subprog, to collect all possible overloadings.
6412 if Subp /= Entity (Subprog) then
6413 Add_One_Interp (Subprog, Subp, Etype (Subp));
6417 -- If the call may be an indexed call, retrieve component type of
6418 -- resulting expression, and add possible interpretation.
6423 if Nkind (Call) = N_Function_Call
6424 and then Nkind (Parent (N)) = N_Indexed_Component
6425 and then Needs_One_Actual (Subp)
6427 if Is_Array_Type (Etype (Subp)) then
6428 Arr_Type := Etype (Subp);
6430 elsif Is_Access_Type (Etype (Subp))
6431 and then Is_Array_Type (Designated_Type (Etype (Subp)))
6433 Arr_Type := Designated_Type (Etype (Subp));
6437 if Present (Arr_Type) then
6439 -- Verify that the actuals (excluding the object) match the types
6447 Actual := Next (First_Actual (Call));
6448 Index := First_Index (Arr_Type);
6449 while Present (Actual) and then Present (Index) loop
6450 if not Has_Compatible_Type (Actual, Etype (Index)) then
6455 Next_Actual (Actual);
6461 and then Present (Arr_Type)
6463 Comp_Type := Component_Type (Arr_Type);
6467 if Present (Comp_Type)
6468 and then Etype (Subprog) /= Comp_Type
6470 Add_One_Interp (Subprog, Subp, Comp_Type);
6474 if Etype (Call) /= Any_Type then
6479 end Valid_Candidate;
6481 -------------------------------
6482 -- Complete_Object_Operation --
6483 -------------------------------
6485 procedure Complete_Object_Operation
6486 (Call_Node : Node_Id;
6487 Node_To_Replace : Node_Id)
6489 Control : constant Entity_Id := First_Formal (Entity (Subprog));
6490 Formal_Type : constant Entity_Id := Etype (Control);
6491 First_Actual : Node_Id;
6494 -- Place the name of the operation, with its interpretations,
6495 -- on the rewritten call.
6497 Set_Name (Call_Node, Subprog);
6499 First_Actual := First (Parameter_Associations (Call_Node));
6501 -- For cross-reference purposes, treat the new node as being in
6502 -- the source if the original one is.
6504 Set_Comes_From_Source (Subprog, Comes_From_Source (N));
6505 Set_Comes_From_Source (Call_Node, Comes_From_Source (N));
6507 if Nkind (N) = N_Selected_Component
6508 and then not Inside_A_Generic
6510 Set_Entity (Selector_Name (N), Entity (Subprog));
6513 -- If need be, rewrite first actual as an explicit dereference
6514 -- If the call is overloaded, the rewriting can only be done
6515 -- once the primitive operation is identified.
6517 if Is_Overloaded (Subprog) then
6519 -- The prefix itself may be overloaded, and its interpretations
6520 -- must be propagated to the new actual in the call.
6522 if Is_Overloaded (Obj) then
6523 Save_Interps (Obj, First_Actual);
6526 Rewrite (First_Actual, Obj);
6528 elsif not Is_Access_Type (Formal_Type)
6529 and then Is_Access_Type (Etype (Obj))
6531 Rewrite (First_Actual,
6532 Make_Explicit_Dereference (Sloc (Obj), Obj));
6533 Analyze (First_Actual);
6535 -- If we need to introduce an explicit dereference, verify that
6536 -- the resulting actual is compatible with the mode of the formal.
6538 if Ekind (First_Formal (Entity (Subprog))) /= E_In_Parameter
6539 and then Is_Access_Constant (Etype (Obj))
6542 ("expect variable in call to&", Prefix (N), Entity (Subprog));
6545 -- Conversely, if the formal is an access parameter and the object
6546 -- is not, replace the actual with a 'Access reference. Its analysis
6547 -- will check that the object is aliased.
6549 elsif Is_Access_Type (Formal_Type)
6550 and then not Is_Access_Type (Etype (Obj))
6552 -- A special case: A.all'access is illegal if A is an access to a
6553 -- constant and the context requires an access to a variable.
6555 if not Is_Access_Constant (Formal_Type) then
6556 if (Nkind (Obj) = N_Explicit_Dereference
6557 and then Is_Access_Constant (Etype (Prefix (Obj))))
6558 or else not Is_Variable (Obj)
6561 ("actual for& must be a variable", Obj, Control);
6565 Rewrite (First_Actual,
6566 Make_Attribute_Reference (Loc,
6567 Attribute_Name => Name_Access,
6568 Prefix => Relocate_Node (Obj)));
6570 if not Is_Aliased_View (Obj) then
6572 ("object in prefixed call to& must be aliased"
6573 & " (RM-2005 4.3.1 (13))",
6574 Prefix (First_Actual), Subprog);
6577 Analyze (First_Actual);
6580 if Is_Overloaded (Obj) then
6581 Save_Interps (Obj, First_Actual);
6584 Rewrite (First_Actual, Obj);
6587 Rewrite (Node_To_Replace, Call_Node);
6589 -- Propagate the interpretations collected in subprog to the new
6590 -- function call node, to be resolved from context.
6592 if Is_Overloaded (Subprog) then
6593 Save_Interps (Subprog, Node_To_Replace);
6596 Analyze (Node_To_Replace);
6598 -- If the operation has been rewritten into a call, which may get
6599 -- subsequently an explicit dereference, preserve the type on the
6600 -- original node (selected component or indexed component) for
6601 -- subsequent legality tests, e.g. Is_Variable. which examines
6602 -- the original node.
6604 if Nkind (Node_To_Replace) = N_Function_Call then
6606 (Original_Node (Node_To_Replace), Etype (Node_To_Replace));
6609 end Complete_Object_Operation;
6611 ----------------------
6612 -- Report_Ambiguity --
6613 ----------------------
6615 procedure Report_Ambiguity (Op : Entity_Id) is
6616 Access_Formal : constant Boolean :=
6617 Is_Access_Type (Etype (First_Formal (Op)));
6618 Access_Actual : constant Boolean :=
6619 Is_Access_Type (Etype (Prefix (N)));
6622 Error_Msg_Sloc := Sloc (Op);
6624 if Access_Formal and then not Access_Actual then
6625 if Nkind (Parent (Op)) = N_Full_Type_Declaration then
6627 ("\possible interpretation"
6628 & " (inherited, with implicit 'Access) #", N);
6631 ("\possible interpretation (with implicit 'Access) #", N);
6634 elsif not Access_Formal and then Access_Actual then
6635 if Nkind (Parent (Op)) = N_Full_Type_Declaration then
6637 ("\possible interpretation"
6638 & " ( inherited, with implicit dereference) #", N);
6641 ("\possible interpretation (with implicit dereference) #", N);
6645 if Nkind (Parent (Op)) = N_Full_Type_Declaration then
6646 Error_Msg_N ("\possible interpretation (inherited)#", N);
6648 Error_Msg_N -- CODEFIX
6649 ("\possible interpretation#", N);
6652 end Report_Ambiguity;
6654 --------------------------------
6655 -- Transform_Object_Operation --
6656 --------------------------------
6658 procedure Transform_Object_Operation
6659 (Call_Node : out Node_Id;
6660 Node_To_Replace : out Node_Id)
6662 Dummy : constant Node_Id := New_Copy (Obj);
6663 -- Placeholder used as a first parameter in the call, replaced
6664 -- eventually by the proper object.
6666 Parent_Node : constant Node_Id := Parent (N);
6672 -- Common case covering 1) Call to a procedure and 2) Call to a
6673 -- function that has some additional actuals.
6675 if Nkind_In (Parent_Node, N_Function_Call,
6676 N_Procedure_Call_Statement)
6678 -- N is a selected component node containing the name of the
6679 -- subprogram. If N is not the name of the parent node we must
6680 -- not replace the parent node by the new construct. This case
6681 -- occurs when N is a parameterless call to a subprogram that
6682 -- is an actual parameter of a call to another subprogram. For
6684 -- Some_Subprogram (..., Obj.Operation, ...)
6686 and then Name (Parent_Node) = N
6688 Node_To_Replace := Parent_Node;
6690 Actuals := Parameter_Associations (Parent_Node);
6692 if Present (Actuals) then
6693 Prepend (Dummy, Actuals);
6695 Actuals := New_List (Dummy);
6698 if Nkind (Parent_Node) = N_Procedure_Call_Statement then
6700 Make_Procedure_Call_Statement (Loc,
6701 Name => New_Copy (Subprog),
6702 Parameter_Associations => Actuals);
6706 Make_Function_Call (Loc,
6707 Name => New_Copy (Subprog),
6708 Parameter_Associations => Actuals);
6712 -- Before analysis, a function call appears as an indexed component
6713 -- if there are no named associations.
6715 elsif Nkind (Parent_Node) = N_Indexed_Component
6716 and then N = Prefix (Parent_Node)
6718 Node_To_Replace := Parent_Node;
6719 Actuals := Expressions (Parent_Node);
6721 Actual := First (Actuals);
6722 while Present (Actual) loop
6727 Prepend (Dummy, Actuals);
6730 Make_Function_Call (Loc,
6731 Name => New_Copy (Subprog),
6732 Parameter_Associations => Actuals);
6734 -- Parameterless call: Obj.F is rewritten as F (Obj)
6737 Node_To_Replace := N;
6740 Make_Function_Call (Loc,
6741 Name => New_Copy (Subprog),
6742 Parameter_Associations => New_List (Dummy));
6744 end Transform_Object_Operation;
6746 ------------------------------
6747 -- Try_Class_Wide_Operation --
6748 ------------------------------
6750 function Try_Class_Wide_Operation
6751 (Call_Node : Node_Id;
6752 Node_To_Replace : Node_Id) return Boolean
6754 Anc_Type : Entity_Id;
6755 Matching_Op : Entity_Id := Empty;
6758 procedure Traverse_Homonyms
6759 (Anc_Type : Entity_Id;
6760 Error : out Boolean);
6761 -- Traverse the homonym chain of the subprogram searching for those
6762 -- homonyms whose first formal has the Anc_Type's class-wide type,
6763 -- or an anonymous access type designating the class-wide type. If
6764 -- an ambiguity is detected, then Error is set to True.
6766 procedure Traverse_Interfaces
6767 (Anc_Type : Entity_Id;
6768 Error : out Boolean);
6769 -- Traverse the list of interfaces, if any, associated with Anc_Type
6770 -- and search for acceptable class-wide homonyms associated with each
6771 -- interface. If an ambiguity is detected, then Error is set to True.
6773 -----------------------
6774 -- Traverse_Homonyms --
6775 -----------------------
6777 procedure Traverse_Homonyms
6778 (Anc_Type : Entity_Id;
6779 Error : out Boolean)
6781 Cls_Type : Entity_Id;
6789 Cls_Type := Class_Wide_Type (Anc_Type);
6791 Hom := Current_Entity (Subprog);
6793 -- Find a non-hidden operation whose first parameter is of the
6794 -- class-wide type, a subtype thereof, or an anonymous access
6797 while Present (Hom) loop
6798 if Ekind_In (Hom, E_Procedure, E_Function)
6799 and then not Is_Hidden (Hom)
6800 and then Scope (Hom) = Scope (Anc_Type)
6801 and then Present (First_Formal (Hom))
6803 (Base_Type (Etype (First_Formal (Hom))) = Cls_Type
6805 (Is_Access_Type (Etype (First_Formal (Hom)))
6807 Ekind (Etype (First_Formal (Hom))) =
6808 E_Anonymous_Access_Type
6811 (Designated_Type (Etype (First_Formal (Hom)))) =
6814 Set_Etype (Call_Node, Any_Type);
6815 Set_Is_Overloaded (Call_Node, False);
6818 if No (Matching_Op) then
6819 Hom_Ref := New_Reference_To (Hom, Sloc (Subprog));
6820 Set_Etype (Call_Node, Any_Type);
6821 Set_Parent (Call_Node, Parent (Node_To_Replace));
6823 Set_Name (Call_Node, Hom_Ref);
6828 Report => Report_Error,
6830 Skip_First => True);
6833 Valid_Candidate (Success, Call_Node, Hom);
6839 Report => Report_Error,
6841 Skip_First => True);
6843 if Present (Valid_Candidate (Success, Call_Node, Hom))
6844 and then Nkind (Call_Node) /= N_Function_Call
6846 Error_Msg_NE ("ambiguous call to&", N, Hom);
6847 Report_Ambiguity (Matching_Op);
6848 Report_Ambiguity (Hom);
6855 Hom := Homonym (Hom);
6857 end Traverse_Homonyms;
6859 -------------------------
6860 -- Traverse_Interfaces --
6861 -------------------------
6863 procedure Traverse_Interfaces
6864 (Anc_Type : Entity_Id;
6865 Error : out Boolean)
6867 Intface_List : constant List_Id :=
6868 Abstract_Interface_List (Anc_Type);
6874 if Is_Non_Empty_List (Intface_List) then
6875 Intface := First (Intface_List);
6876 while Present (Intface) loop
6878 -- Look for acceptable class-wide homonyms associated with
6881 Traverse_Homonyms (Etype (Intface), Error);
6887 -- Continue the search by looking at each of the interface's
6888 -- associated interface ancestors.
6890 Traverse_Interfaces (Etype (Intface), Error);
6899 end Traverse_Interfaces;
6901 -- Start of processing for Try_Class_Wide_Operation
6904 -- Loop through ancestor types (including interfaces), traversing
6905 -- the homonym chain of the subprogram, trying out those homonyms
6906 -- whose first formal has the class-wide type of the ancestor, or
6907 -- an anonymous access type designating the class-wide type.
6909 Anc_Type := Obj_Type;
6911 -- Look for a match among homonyms associated with the ancestor
6913 Traverse_Homonyms (Anc_Type, Error);
6919 -- Continue the search for matches among homonyms associated with
6920 -- any interfaces implemented by the ancestor.
6922 Traverse_Interfaces (Anc_Type, Error);
6928 exit when Etype (Anc_Type) = Anc_Type;
6929 Anc_Type := Etype (Anc_Type);
6932 if Present (Matching_Op) then
6933 Set_Etype (Call_Node, Etype (Matching_Op));
6936 return Present (Matching_Op);
6937 end Try_Class_Wide_Operation;
6939 -----------------------------------
6940 -- Try_One_Prefix_Interpretation --
6941 -----------------------------------
6943 procedure Try_One_Prefix_Interpretation (T : Entity_Id) is
6947 if Is_Access_Type (Obj_Type) then
6948 Obj_Type := Designated_Type (Obj_Type);
6951 if Ekind (Obj_Type) = E_Private_Subtype then
6952 Obj_Type := Base_Type (Obj_Type);
6955 if Is_Class_Wide_Type (Obj_Type) then
6956 Obj_Type := Etype (Class_Wide_Type (Obj_Type));
6959 -- The type may have be obtained through a limited_with clause,
6960 -- in which case the primitive operations are available on its
6961 -- non-limited view. If still incomplete, retrieve full view.
6963 if Ekind (Obj_Type) = E_Incomplete_Type
6964 and then From_With_Type (Obj_Type)
6966 Obj_Type := Get_Full_View (Non_Limited_View (Obj_Type));
6969 -- If the object is not tagged, or the type is still an incomplete
6970 -- type, this is not a prefixed call.
6972 if not Is_Tagged_Type (Obj_Type)
6973 or else Is_Incomplete_Type (Obj_Type)
6978 if Try_Primitive_Operation
6979 (Call_Node => New_Call_Node,
6980 Node_To_Replace => Node_To_Replace)
6982 Try_Class_Wide_Operation
6983 (Call_Node => New_Call_Node,
6984 Node_To_Replace => Node_To_Replace)
6988 end Try_One_Prefix_Interpretation;
6990 -----------------------------
6991 -- Try_Primitive_Operation --
6992 -----------------------------
6994 function Try_Primitive_Operation
6995 (Call_Node : Node_Id;
6996 Node_To_Replace : Node_Id) return Boolean
6999 Prim_Op : Entity_Id;
7000 Matching_Op : Entity_Id := Empty;
7001 Prim_Op_Ref : Node_Id := Empty;
7003 Corr_Type : Entity_Id := Empty;
7004 -- If the prefix is a synchronized type, the controlling type of
7005 -- the primitive operation is the corresponding record type, else
7006 -- this is the object type itself.
7008 Success : Boolean := False;
7010 function Collect_Generic_Type_Ops (T : Entity_Id) return Elist_Id;
7011 -- For tagged types the candidate interpretations are found in
7012 -- the list of primitive operations of the type and its ancestors.
7013 -- For formal tagged types we have to find the operations declared
7014 -- in the same scope as the type (including in the generic formal
7015 -- part) because the type itself carries no primitive operations,
7016 -- except for formal derived types that inherit the operations of
7017 -- the parent and progenitors.
7018 -- If the context is a generic subprogram body, the generic formals
7019 -- are visible by name, but are not in the entity list of the
7020 -- subprogram because that list starts with the subprogram formals.
7021 -- We retrieve the candidate operations from the generic declaration.
7023 function Is_Private_Overriding (Op : Entity_Id) return Boolean;
7024 -- An operation that overrides an inherited operation in the private
7025 -- part of its package may be hidden, but if the inherited operation
7026 -- is visible a direct call to it will dispatch to the private one,
7027 -- which is therefore a valid candidate.
7029 function Valid_First_Argument_Of (Op : Entity_Id) return Boolean;
7030 -- Verify that the prefix, dereferenced if need be, is a valid
7031 -- controlling argument in a call to Op. The remaining actuals
7032 -- are checked in the subsequent call to Analyze_One_Call.
7034 ------------------------------
7035 -- Collect_Generic_Type_Ops --
7036 ------------------------------
7038 function Collect_Generic_Type_Ops (T : Entity_Id) return Elist_Id is
7039 Bas : constant Entity_Id := Base_Type (T);
7040 Candidates : constant Elist_Id := New_Elmt_List;
7044 procedure Check_Candidate;
7045 -- The operation is a candidate if its first parameter is a
7046 -- controlling operand of the desired type.
7048 -----------------------
7049 -- Check_Candidate; --
7050 -----------------------
7052 procedure Check_Candidate is
7054 Formal := First_Formal (Subp);
7057 and then Is_Controlling_Formal (Formal)
7059 (Base_Type (Etype (Formal)) = Bas
7061 (Is_Access_Type (Etype (Formal))
7062 and then Designated_Type (Etype (Formal)) = Bas))
7064 Append_Elmt (Subp, Candidates);
7066 end Check_Candidate;
7068 -- Start of processing for Collect_Generic_Type_Ops
7071 if Is_Derived_Type (T) then
7072 return Primitive_Operations (T);
7074 elsif Ekind_In (Scope (T), E_Procedure, E_Function) then
7076 -- Scan the list of generic formals to find subprograms
7077 -- that may have a first controlling formal of the type.
7079 if Nkind (Unit_Declaration_Node (Scope (T)))
7080 = N_Generic_Subprogram_Declaration
7087 First (Generic_Formal_Declarations
7088 (Unit_Declaration_Node (Scope (T))));
7089 while Present (Decl) loop
7090 if Nkind (Decl) in N_Formal_Subprogram_Declaration then
7091 Subp := Defining_Entity (Decl);
7102 -- Scan the list of entities declared in the same scope as
7103 -- the type. In general this will be an open scope, given that
7104 -- the call we are analyzing can only appear within a generic
7105 -- declaration or body (either the one that declares T, or a
7108 -- For a subtype representing a generic actual type, go to the
7111 if Is_Generic_Actual_Type (T) then
7112 Subp := First_Entity (Scope (Base_Type (T)));
7114 Subp := First_Entity (Scope (T));
7117 while Present (Subp) loop
7118 if Is_Overloadable (Subp) then
7127 end Collect_Generic_Type_Ops;
7129 ---------------------------
7130 -- Is_Private_Overriding --
7131 ---------------------------
7133 function Is_Private_Overriding (Op : Entity_Id) return Boolean is
7134 Visible_Op : constant Entity_Id := Homonym (Op);
7137 return Present (Visible_Op)
7138 and then Scope (Op) = Scope (Visible_Op)
7139 and then not Comes_From_Source (Visible_Op)
7140 and then Alias (Visible_Op) = Op
7141 and then not Is_Hidden (Visible_Op);
7142 end Is_Private_Overriding;
7144 -----------------------------
7145 -- Valid_First_Argument_Of --
7146 -----------------------------
7148 function Valid_First_Argument_Of (Op : Entity_Id) return Boolean is
7149 Typ : Entity_Id := Etype (First_Formal (Op));
7152 if Is_Concurrent_Type (Typ)
7153 and then Present (Corresponding_Record_Type (Typ))
7155 Typ := Corresponding_Record_Type (Typ);
7158 -- Simple case. Object may be a subtype of the tagged type or
7159 -- may be the corresponding record of a synchronized type.
7161 return Obj_Type = Typ
7162 or else Base_Type (Obj_Type) = Typ
7163 or else Corr_Type = Typ
7165 -- Prefix can be dereferenced
7168 (Is_Access_Type (Corr_Type)
7169 and then Designated_Type (Corr_Type) = Typ)
7171 -- Formal is an access parameter, for which the object
7172 -- can provide an access.
7175 (Ekind (Typ) = E_Anonymous_Access_Type
7176 and then Designated_Type (Typ) = Base_Type (Corr_Type));
7177 end Valid_First_Argument_Of;
7179 -- Start of processing for Try_Primitive_Operation
7182 -- Look for subprograms in the list of primitive operations. The name
7183 -- must be identical, and the kind of call indicates the expected
7184 -- kind of operation (function or procedure). If the type is a
7185 -- (tagged) synchronized type, the primitive ops are attached to the
7186 -- corresponding record (base) type.
7188 if Is_Concurrent_Type (Obj_Type) then
7189 if Present (Corresponding_Record_Type (Obj_Type)) then
7190 Corr_Type := Base_Type (Corresponding_Record_Type (Obj_Type));
7191 Elmt := First_Elmt (Primitive_Operations (Corr_Type));
7193 Corr_Type := Obj_Type;
7194 Elmt := First_Elmt (Collect_Generic_Type_Ops (Obj_Type));
7197 elsif not Is_Generic_Type (Obj_Type) then
7198 Corr_Type := Obj_Type;
7199 Elmt := First_Elmt (Primitive_Operations (Obj_Type));
7202 Corr_Type := Obj_Type;
7203 Elmt := First_Elmt (Collect_Generic_Type_Ops (Obj_Type));
7206 while Present (Elmt) loop
7207 Prim_Op := Node (Elmt);
7209 if Chars (Prim_Op) = Chars (Subprog)
7210 and then Present (First_Formal (Prim_Op))
7211 and then Valid_First_Argument_Of (Prim_Op)
7213 (Nkind (Call_Node) = N_Function_Call)
7214 = (Ekind (Prim_Op) = E_Function)
7216 -- Ada 2005 (AI-251): If this primitive operation corresponds
7217 -- with an immediate ancestor interface there is no need to add
7218 -- it to the list of interpretations; the corresponding aliased
7219 -- primitive is also in this list of primitive operations and
7220 -- will be used instead.
7222 if (Present (Interface_Alias (Prim_Op))
7223 and then Is_Ancestor (Find_Dispatching_Type
7224 (Alias (Prim_Op)), Corr_Type))
7226 -- Do not consider hidden primitives unless the type is in an
7227 -- open scope or we are within an instance, where visibility
7228 -- is known to be correct, or else if this is an overriding
7229 -- operation in the private part for an inherited operation.
7231 or else (Is_Hidden (Prim_Op)
7232 and then not Is_Immediately_Visible (Obj_Type)
7233 and then not In_Instance
7234 and then not Is_Private_Overriding (Prim_Op))
7239 Set_Etype (Call_Node, Any_Type);
7240 Set_Is_Overloaded (Call_Node, False);
7242 if No (Matching_Op) then
7243 Prim_Op_Ref := New_Reference_To (Prim_Op, Sloc (Subprog));
7244 Candidate := Prim_Op;
7246 Set_Parent (Call_Node, Parent (Node_To_Replace));
7248 Set_Name (Call_Node, Prim_Op_Ref);
7254 Report => Report_Error,
7256 Skip_First => True);
7258 Matching_Op := Valid_Candidate (Success, Call_Node, Prim_Op);
7260 -- More than one interpretation, collect for subsequent
7261 -- disambiguation. If this is a procedure call and there
7262 -- is another match, report ambiguity now.
7268 Report => Report_Error,
7270 Skip_First => True);
7272 if Present (Valid_Candidate (Success, Call_Node, Prim_Op))
7273 and then Nkind (Call_Node) /= N_Function_Call
7275 Error_Msg_NE ("ambiguous call to&", N, Prim_Op);
7276 Report_Ambiguity (Matching_Op);
7277 Report_Ambiguity (Prim_Op);
7287 if Present (Matching_Op) then
7288 Set_Etype (Call_Node, Etype (Matching_Op));
7291 return Present (Matching_Op);
7292 end Try_Primitive_Operation;
7294 -- Start of processing for Try_Object_Operation
7297 Analyze_Expression (Obj);
7299 -- Analyze the actuals if node is known to be a subprogram call
7301 if Is_Subprg_Call and then N = Name (Parent (N)) then
7302 Actual := First (Parameter_Associations (Parent (N)));
7303 while Present (Actual) loop
7304 Analyze_Expression (Actual);
7309 -- Build a subprogram call node, using a copy of Obj as its first
7310 -- actual. This is a placeholder, to be replaced by an explicit
7311 -- dereference when needed.
7313 Transform_Object_Operation
7314 (Call_Node => New_Call_Node,
7315 Node_To_Replace => Node_To_Replace);
7317 Set_Etype (New_Call_Node, Any_Type);
7318 Set_Etype (Subprog, Any_Type);
7319 Set_Parent (New_Call_Node, Parent (Node_To_Replace));
7321 if not Is_Overloaded (Obj) then
7322 Try_One_Prefix_Interpretation (Obj_Type);
7329 Get_First_Interp (Obj, I, It);
7330 while Present (It.Nam) loop
7331 Try_One_Prefix_Interpretation (It.Typ);
7332 Get_Next_Interp (I, It);
7337 if Etype (New_Call_Node) /= Any_Type then
7338 Complete_Object_Operation
7339 (Call_Node => New_Call_Node,
7340 Node_To_Replace => Node_To_Replace);
7343 elsif Present (Candidate) then
7345 -- The argument list is not type correct. Re-analyze with error
7346 -- reporting enabled, and use one of the possible candidates.
7347 -- In All_Errors_Mode, re-analyze all failed interpretations.
7349 if All_Errors_Mode then
7350 Report_Error := True;
7351 if Try_Primitive_Operation
7352 (Call_Node => New_Call_Node,
7353 Node_To_Replace => Node_To_Replace)
7356 Try_Class_Wide_Operation
7357 (Call_Node => New_Call_Node,
7358 Node_To_Replace => Node_To_Replace)
7365 (N => New_Call_Node,
7369 Skip_First => True);
7372 -- No need for further errors
7377 -- There was no candidate operation, so report it as an error
7378 -- in the caller: Analyze_Selected_Component.
7382 end Try_Object_Operation;
7388 procedure wpo (T : Entity_Id) is
7393 if not Is_Tagged_Type (T) then
7397 E := First_Elmt (Primitive_Operations (Base_Type (T)));
7398 while Present (E) loop
7400 Write_Int (Int (Op));
7401 Write_Str (" === ");
7402 Write_Name (Chars (Op));
7404 Write_Name (Chars (Scope (Op)));