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 Check_Formal_Restriction ("allocator is not allowed", N);
374 -- Deal with allocator restrictions
376 -- In accordance with H.4(7), the No_Allocators restriction only applies
377 -- to user-written allocators. The same consideration applies to the
378 -- No_Allocators_Before_Elaboration restriction.
380 if Comes_From_Source (N) then
381 Check_Restriction (No_Allocators, N);
383 -- Processing for No_Allocators_After_Elaboration, loop to look at
384 -- enclosing context, checking task case and main subprogram case.
388 while Present (P) loop
390 -- In both cases we need a handled sequence of statements, where
391 -- the occurrence of the allocator is within the statements.
393 if Nkind (P) = N_Handled_Sequence_Of_Statements
394 and then Is_List_Member (C)
395 and then List_Containing (C) = Statements (P)
397 -- Check for allocator within task body, this is a definite
398 -- violation of No_Allocators_After_Elaboration we can detect.
400 if Nkind (Original_Node (Parent (P))) = N_Task_Body then
401 Check_Restriction (No_Allocators_After_Elaboration, N);
405 -- The other case is appearance in a subprogram body. This may
406 -- be a violation if this is a library level subprogram, and it
407 -- turns out to be used as the main program, but only the
408 -- binder knows that, so just record the occurrence.
410 if Nkind (Original_Node (Parent (P))) = N_Subprogram_Body
411 and then Nkind (Parent (Parent (P))) = N_Compilation_Unit
413 Set_Has_Allocator (Current_Sem_Unit);
422 -- Analyze the allocator
424 if Nkind (E) = N_Qualified_Expression then
425 Acc_Type := Create_Itype (E_Allocator_Type, N);
426 Set_Etype (Acc_Type, Acc_Type);
427 Find_Type (Subtype_Mark (E));
429 -- Analyze the qualified expression, and apply the name resolution
430 -- rule given in 4.7 (3).
433 Type_Id := Etype (E);
434 Set_Directly_Designated_Type (Acc_Type, Type_Id);
436 Resolve (Expression (E), Type_Id);
438 if Is_Limited_Type (Type_Id)
439 and then Comes_From_Source (N)
440 and then not In_Instance_Body
442 if not OK_For_Limited_Init (Type_Id, Expression (E)) then
443 Error_Msg_N ("initialization not allowed for limited types", N);
444 Explain_Limited_Type (Type_Id, N);
448 -- A qualified expression requires an exact match of the type,
449 -- class-wide matching is not allowed.
451 -- if Is_Class_Wide_Type (Type_Id)
452 -- and then Base_Type
453 -- (Etype (Expression (E))) /= Base_Type (Type_Id)
455 -- Wrong_Type (Expression (E), Type_Id);
458 Check_Non_Static_Context (Expression (E));
460 -- We don't analyze the qualified expression itself because it's
461 -- part of the allocator
463 Set_Etype (E, Type_Id);
465 -- Case where allocator has a subtype indication
470 Base_Typ : Entity_Id;
473 -- If the allocator includes a N_Subtype_Indication then a
474 -- constraint is present, otherwise the node is a subtype mark.
475 -- Introduce an explicit subtype declaration into the tree
476 -- defining some anonymous subtype and rewrite the allocator to
477 -- use this subtype rather than the subtype indication.
479 -- It is important to introduce the explicit subtype declaration
480 -- so that the bounds of the subtype indication are attached to
481 -- the tree in case the allocator is inside a generic unit.
483 if Nkind (E) = N_Subtype_Indication then
485 -- A constraint is only allowed for a composite type in Ada
486 -- 95. In Ada 83, a constraint is also allowed for an
487 -- access-to-composite type, but the constraint is ignored.
489 Find_Type (Subtype_Mark (E));
490 Base_Typ := Entity (Subtype_Mark (E));
492 if Is_Elementary_Type (Base_Typ) then
493 if not (Ada_Version = Ada_83
494 and then Is_Access_Type (Base_Typ))
496 Error_Msg_N ("constraint not allowed here", E);
498 if Nkind (Constraint (E)) =
499 N_Index_Or_Discriminant_Constraint
501 Error_Msg_N -- CODEFIX
502 ("\if qualified expression was meant, " &
503 "use apostrophe", Constraint (E));
507 -- Get rid of the bogus constraint:
509 Rewrite (E, New_Copy_Tree (Subtype_Mark (E)));
510 Analyze_Allocator (N);
513 -- Ada 2005, AI-363: if the designated type has a constrained
514 -- partial view, it cannot receive a discriminant constraint,
515 -- and the allocated object is unconstrained.
517 elsif Ada_Version >= Ada_2005
518 and then Has_Constrained_Partial_View (Base_Typ)
521 ("constraint no allowed when type " &
522 "has a constrained partial view", Constraint (E));
525 if Expander_Active then
526 Def_Id := Make_Temporary (Loc, 'S');
529 Make_Subtype_Declaration (Loc,
530 Defining_Identifier => Def_Id,
531 Subtype_Indication => Relocate_Node (E)));
533 if Sav_Errs /= Serious_Errors_Detected
534 and then Nkind (Constraint (E)) =
535 N_Index_Or_Discriminant_Constraint
537 Error_Msg_N -- CODEFIX
538 ("if qualified expression was meant, " &
539 "use apostrophe!", Constraint (E));
542 E := New_Occurrence_Of (Def_Id, Loc);
543 Rewrite (Expression (N), E);
547 Type_Id := Process_Subtype (E, N);
548 Acc_Type := Create_Itype (E_Allocator_Type, N);
549 Set_Etype (Acc_Type, Acc_Type);
550 Set_Directly_Designated_Type (Acc_Type, Type_Id);
551 Check_Fully_Declared (Type_Id, N);
553 -- Ada 2005 (AI-231): If the designated type is itself an access
554 -- type that excludes null, its default initialization will
555 -- be a null object, and we can insert an unconditional raise
556 -- before the allocator.
558 -- Ada 2012 (AI-104): A not null indication here is altogether
561 if Can_Never_Be_Null (Type_Id) then
563 Not_Null_Check : constant Node_Id :=
564 Make_Raise_Constraint_Error (Sloc (E),
565 Reason => CE_Null_Not_Allowed);
568 if Ada_Version >= Ada_2012 then
570 ("an uninitialized allocator cannot have"
571 & " a null exclusion", N);
573 elsif Expander_Active then
574 Insert_Action (N, Not_Null_Check);
575 Analyze (Not_Null_Check);
578 Error_Msg_N ("null value not allowed here?", E);
583 -- Check restriction against dynamically allocated protected
584 -- objects. Note that when limited aggregates are supported,
585 -- a similar test should be applied to an allocator with a
586 -- qualified expression ???
588 if Is_Protected_Type (Type_Id) then
589 Check_Restriction (No_Protected_Type_Allocators, N);
592 -- Check for missing initialization. Skip this check if we already
593 -- had errors on analyzing the allocator, since in that case these
594 -- are probably cascaded errors.
596 if Is_Indefinite_Subtype (Type_Id)
597 and then Serious_Errors_Detected = Sav_Errs
599 if Is_Class_Wide_Type (Type_Id) then
601 ("initialization required in class-wide allocation", N);
603 if Ada_Version < Ada_2005
604 and then Is_Limited_Type (Type_Id)
606 Error_Msg_N ("unconstrained allocation not allowed", N);
608 if Is_Array_Type (Type_Id) then
610 ("\constraint with array bounds required", N);
612 elsif Has_Unknown_Discriminants (Type_Id) then
615 else pragma Assert (Has_Discriminants (Type_Id));
617 ("\constraint with discriminant values required", N);
620 -- Limited Ada 2005 and general non-limited case
624 ("uninitialized unconstrained allocation not allowed",
627 if Is_Array_Type (Type_Id) then
629 ("\qualified expression or constraint with " &
630 "array bounds required", N);
632 elsif Has_Unknown_Discriminants (Type_Id) then
633 Error_Msg_N ("\qualified expression required", N);
635 else pragma Assert (Has_Discriminants (Type_Id));
637 ("\qualified expression or constraint with " &
638 "discriminant values required", N);
646 if Is_Abstract_Type (Type_Id) then
647 Error_Msg_N ("cannot allocate abstract object", E);
650 if Has_Task (Designated_Type (Acc_Type)) then
651 Check_Restriction (No_Tasking, N);
652 Check_Restriction (Max_Tasks, N);
653 Check_Restriction (No_Task_Allocators, N);
655 -- Check that an allocator with task parts isn't for a nested access
656 -- type when restriction No_Task_Hierarchy applies.
658 if not Is_Library_Level_Entity (Acc_Type) then
659 Check_Restriction (No_Task_Hierarchy, N);
663 -- Check that an allocator of a nested access type doesn't create a
664 -- protected object when restriction No_Local_Protected_Objects applies.
665 -- We don't have an equivalent to Has_Task for protected types, so only
666 -- cases where the designated type itself is a protected type are
667 -- currently checked. ???
669 if Is_Protected_Type (Designated_Type (Acc_Type))
670 and then not Is_Library_Level_Entity (Acc_Type)
672 Check_Restriction (No_Local_Protected_Objects, N);
675 -- If the No_Streams restriction is set, check that the type of the
676 -- object is not, and does not contain, any subtype derived from
677 -- Ada.Streams.Root_Stream_Type. Note that we guard the call to
678 -- Has_Stream just for efficiency reasons. There is no point in
679 -- spending time on a Has_Stream check if the restriction is not set.
681 if Restriction_Check_Required (No_Streams) then
682 if Has_Stream (Designated_Type (Acc_Type)) then
683 Check_Restriction (No_Streams, N);
687 Set_Etype (N, Acc_Type);
689 if not Is_Library_Level_Entity (Acc_Type) then
690 Check_Restriction (No_Local_Allocators, N);
693 if Serious_Errors_Detected > Sav_Errs then
694 Set_Error_Posted (N);
695 Set_Etype (N, Any_Type);
697 end Analyze_Allocator;
699 ---------------------------
700 -- Analyze_Arithmetic_Op --
701 ---------------------------
703 procedure Analyze_Arithmetic_Op (N : Node_Id) is
704 L : constant Node_Id := Left_Opnd (N);
705 R : constant Node_Id := Right_Opnd (N);
709 Candidate_Type := Empty;
710 Analyze_Expression (L);
711 Analyze_Expression (R);
713 -- If the entity is already set, the node is the instantiation of a
714 -- generic node with a non-local reference, or was manufactured by a
715 -- call to Make_Op_xxx. In either case the entity is known to be valid,
716 -- and we do not need to collect interpretations, instead we just get
717 -- the single possible interpretation.
721 if Present (Op_Id) then
722 if Ekind (Op_Id) = E_Operator then
724 if Nkind_In (N, N_Op_Divide, N_Op_Mod, N_Op_Multiply, N_Op_Rem)
725 and then Treat_Fixed_As_Integer (N)
729 Set_Etype (N, Any_Type);
730 Find_Arithmetic_Types (L, R, Op_Id, N);
734 Set_Etype (N, Any_Type);
735 Add_One_Interp (N, Op_Id, Etype (Op_Id));
738 -- Entity is not already set, so we do need to collect interpretations
741 Op_Id := Get_Name_Entity_Id (Chars (N));
742 Set_Etype (N, Any_Type);
744 while Present (Op_Id) loop
745 if Ekind (Op_Id) = E_Operator
746 and then Present (Next_Entity (First_Entity (Op_Id)))
748 Find_Arithmetic_Types (L, R, Op_Id, N);
750 -- The following may seem superfluous, because an operator cannot
751 -- be generic, but this ignores the cleverness of the author of
754 elsif Is_Overloadable (Op_Id) then
755 Analyze_User_Defined_Binary_Op (N, Op_Id);
758 Op_Id := Homonym (Op_Id);
763 end Analyze_Arithmetic_Op;
769 -- Function, procedure, and entry calls are checked here. The Name in
770 -- the call may be overloaded. The actuals have been analyzed and may
771 -- themselves be overloaded. On exit from this procedure, the node N
772 -- may have zero, one or more interpretations. In the first case an
773 -- error message is produced. In the last case, the node is flagged
774 -- as overloaded and the interpretations are collected in All_Interp.
776 -- If the name is an Access_To_Subprogram, it cannot be overloaded, but
777 -- the type-checking is similar to that of other calls.
779 procedure Analyze_Call (N : Node_Id) is
780 Actuals : constant List_Id := Parameter_Associations (N);
785 Success : Boolean := False;
787 Deref : Boolean := False;
788 -- Flag indicates whether an interpretation of the prefix is a
789 -- parameterless call that returns an access_to_subprogram.
791 procedure Check_Mixed_Parameter_And_Named_Associations;
792 -- Check that parameter and named associations are not mixed. This is
793 -- a restriction in SPARK mode.
795 function Name_Denotes_Function return Boolean;
796 -- If the type of the name is an access to subprogram, this may be the
797 -- type of a name, or the return type of the function being called. If
798 -- the name is not an entity then it can denote a protected function.
799 -- Until we distinguish Etype from Return_Type, we must use this routine
800 -- to resolve the meaning of the name in the call.
802 procedure No_Interpretation;
803 -- Output error message when no valid interpretation exists
805 --------------------------------------------------
806 -- Check_Mixed_Parameter_And_Named_Associations --
807 --------------------------------------------------
809 procedure Check_Mixed_Parameter_And_Named_Associations is
811 Named_Seen : Boolean;
816 Actual := First (Actuals);
817 while Present (Actual) loop
818 case Nkind (Actual) is
819 when N_Parameter_Association =>
821 Check_Formal_Restriction
822 ("named association cannot follow positional one",
832 end Check_Mixed_Parameter_And_Named_Associations;
834 ---------------------------
835 -- Name_Denotes_Function --
836 ---------------------------
838 function Name_Denotes_Function return Boolean is
840 if Is_Entity_Name (Nam) then
841 return Ekind (Entity (Nam)) = E_Function;
843 elsif Nkind (Nam) = N_Selected_Component then
844 return Ekind (Entity (Selector_Name (Nam))) = E_Function;
849 end Name_Denotes_Function;
851 -----------------------
852 -- No_Interpretation --
853 -----------------------
855 procedure No_Interpretation is
856 L : constant Boolean := Is_List_Member (N);
857 K : constant Node_Kind := Nkind (Parent (N));
860 -- If the node is in a list whose parent is not an expression then it
861 -- must be an attempted procedure call.
863 if L and then K not in N_Subexpr then
864 if Ekind (Entity (Nam)) = E_Generic_Procedure then
866 ("must instantiate generic procedure& before call",
870 ("procedure or entry name expected", Nam);
873 -- Check for tasking cases where only an entry call will do
876 and then Nkind_In (K, N_Entry_Call_Alternative,
877 N_Triggering_Alternative)
879 Error_Msg_N ("entry name expected", Nam);
881 -- Otherwise give general error message
884 Error_Msg_N ("invalid prefix in call", Nam);
886 end No_Interpretation;
888 -- Start of processing for Analyze_Call
891 if SPARK_Mode or else Restriction_Check_Required (SPARK) then
892 Check_Mixed_Parameter_And_Named_Associations;
895 -- Initialize the type of the result of the call to the error type,
896 -- which will be reset if the type is successfully resolved.
898 Set_Etype (N, Any_Type);
902 if not Is_Overloaded (Nam) then
904 -- Only one interpretation to check
906 if Ekind (Etype (Nam)) = E_Subprogram_Type then
907 Nam_Ent := Etype (Nam);
909 -- If the prefix is an access_to_subprogram, this may be an indirect
910 -- call. This is the case if the name in the call is not an entity
911 -- name, or if it is a function name in the context of a procedure
912 -- call. In this latter case, we have a call to a parameterless
913 -- function that returns a pointer_to_procedure which is the entity
914 -- being called. Finally, F (X) may be a call to a parameterless
915 -- function that returns a pointer to a function with parameters.
917 elsif Is_Access_Type (Etype (Nam))
918 and then Ekind (Designated_Type (Etype (Nam))) = E_Subprogram_Type
920 (not Name_Denotes_Function
921 or else Nkind (N) = N_Procedure_Call_Statement
923 (Nkind (Parent (N)) /= N_Explicit_Dereference
924 and then Is_Entity_Name (Nam)
925 and then No (First_Formal (Entity (Nam)))
926 and then Present (Actuals)))
928 Nam_Ent := Designated_Type (Etype (Nam));
929 Insert_Explicit_Dereference (Nam);
931 -- Selected component case. Simple entry or protected operation,
932 -- where the entry name is given by the selector name.
934 elsif Nkind (Nam) = N_Selected_Component then
935 Nam_Ent := Entity (Selector_Name (Nam));
937 if not Ekind_In (Nam_Ent, E_Entry,
942 Error_Msg_N ("name in call is not a callable entity", Nam);
943 Set_Etype (N, Any_Type);
947 -- If the name is an Indexed component, it can be a call to a member
948 -- of an entry family. The prefix must be a selected component whose
949 -- selector is the entry. Analyze_Procedure_Call normalizes several
950 -- kinds of call into this form.
952 elsif Nkind (Nam) = N_Indexed_Component then
953 if Nkind (Prefix (Nam)) = N_Selected_Component then
954 Nam_Ent := Entity (Selector_Name (Prefix (Nam)));
956 Error_Msg_N ("name in call is not a callable entity", Nam);
957 Set_Etype (N, Any_Type);
961 elsif not Is_Entity_Name (Nam) then
962 Error_Msg_N ("name in call is not a callable entity", Nam);
963 Set_Etype (N, Any_Type);
967 Nam_Ent := Entity (Nam);
969 -- If no interpretations, give error message
971 if not Is_Overloadable (Nam_Ent) then
977 -- Operations generated for RACW stub types are called only through
978 -- dispatching, and can never be the static interpretation of a call.
980 if Is_RACW_Stub_Type_Operation (Nam_Ent) then
985 Analyze_One_Call (N, Nam_Ent, True, Success);
987 -- If this is an indirect call, the return type of the access_to
988 -- subprogram may be an incomplete type. At the point of the call,
989 -- use the full type if available, and at the same time update the
990 -- return type of the access_to_subprogram.
993 and then Nkind (Nam) = N_Explicit_Dereference
994 and then Ekind (Etype (N)) = E_Incomplete_Type
995 and then Present (Full_View (Etype (N)))
997 Set_Etype (N, Full_View (Etype (N)));
998 Set_Etype (Nam_Ent, Etype (N));
1002 -- An overloaded selected component must denote overloaded operations
1003 -- of a concurrent type. The interpretations are attached to the
1004 -- simple name of those operations.
1006 if Nkind (Nam) = N_Selected_Component then
1007 Nam := Selector_Name (Nam);
1010 Get_First_Interp (Nam, X, It);
1012 while Present (It.Nam) loop
1016 -- Name may be call that returns an access to subprogram, or more
1017 -- generally an overloaded expression one of whose interpretations
1018 -- yields an access to subprogram. If the name is an entity, we do
1019 -- not dereference, because the node is a call that returns the
1020 -- access type: note difference between f(x), where the call may
1021 -- return an access subprogram type, and f(x)(y), where the type
1022 -- returned by the call to f is implicitly dereferenced to analyze
1025 if Is_Access_Type (Nam_Ent) then
1026 Nam_Ent := Designated_Type (Nam_Ent);
1028 elsif Is_Access_Type (Etype (Nam_Ent))
1030 (not Is_Entity_Name (Nam)
1031 or else Nkind (N) = N_Procedure_Call_Statement)
1032 and then Ekind (Designated_Type (Etype (Nam_Ent)))
1035 Nam_Ent := Designated_Type (Etype (Nam_Ent));
1037 if Is_Entity_Name (Nam) then
1042 -- If the call has been rewritten from a prefixed call, the first
1043 -- parameter has been analyzed, but may need a subsequent
1044 -- dereference, so skip its analysis now.
1046 if N /= Original_Node (N)
1047 and then Nkind (Original_Node (N)) = Nkind (N)
1048 and then Nkind (Name (N)) /= Nkind (Name (Original_Node (N)))
1049 and then Present (Parameter_Associations (N))
1050 and then Present (Etype (First (Parameter_Associations (N))))
1053 (N, Nam_Ent, False, Success, Skip_First => True);
1055 Analyze_One_Call (N, Nam_Ent, False, Success);
1058 -- If the interpretation succeeds, mark the proper type of the
1059 -- prefix (any valid candidate will do). If not, remove the
1060 -- candidate interpretation. This only needs to be done for
1061 -- overloaded protected operations, for other entities disambi-
1062 -- guation is done directly in Resolve.
1066 and then Nkind (Parent (N)) /= N_Explicit_Dereference
1068 Set_Entity (Nam, It.Nam);
1069 Insert_Explicit_Dereference (Nam);
1070 Set_Etype (Nam, Nam_Ent);
1073 Set_Etype (Nam, It.Typ);
1076 elsif Nkind_In (Name (N), N_Selected_Component,
1082 Get_Next_Interp (X, It);
1085 -- If the name is the result of a function call, it can only
1086 -- be a call to a function returning an access to subprogram.
1087 -- Insert explicit dereference.
1089 if Nkind (Nam) = N_Function_Call then
1090 Insert_Explicit_Dereference (Nam);
1093 if Etype (N) = Any_Type then
1095 -- None of the interpretations is compatible with the actuals
1097 Diagnose_Call (N, Nam);
1099 -- Special checks for uninstantiated put routines
1101 if Nkind (N) = N_Procedure_Call_Statement
1102 and then Is_Entity_Name (Nam)
1103 and then Chars (Nam) = Name_Put
1104 and then List_Length (Actuals) = 1
1107 Arg : constant Node_Id := First (Actuals);
1111 if Nkind (Arg) = N_Parameter_Association then
1112 Typ := Etype (Explicit_Actual_Parameter (Arg));
1117 if Is_Signed_Integer_Type (Typ) then
1119 ("possible missing instantiation of " &
1120 "'Text_'I'O.'Integer_'I'O!", Nam);
1122 elsif Is_Modular_Integer_Type (Typ) then
1124 ("possible missing instantiation of " &
1125 "'Text_'I'O.'Modular_'I'O!", Nam);
1127 elsif Is_Floating_Point_Type (Typ) then
1129 ("possible missing instantiation of " &
1130 "'Text_'I'O.'Float_'I'O!", Nam);
1132 elsif Is_Ordinary_Fixed_Point_Type (Typ) then
1134 ("possible missing instantiation of " &
1135 "'Text_'I'O.'Fixed_'I'O!", Nam);
1137 elsif Is_Decimal_Fixed_Point_Type (Typ) then
1139 ("possible missing instantiation of " &
1140 "'Text_'I'O.'Decimal_'I'O!", Nam);
1142 elsif Is_Enumeration_Type (Typ) then
1144 ("possible missing instantiation of " &
1145 "'Text_'I'O.'Enumeration_'I'O!", Nam);
1150 elsif not Is_Overloaded (N)
1151 and then Is_Entity_Name (Nam)
1153 -- Resolution yields a single interpretation. Verify that the
1154 -- reference has capitalization consistent with the declaration.
1156 Set_Entity_With_Style_Check (Nam, Entity (Nam));
1157 Generate_Reference (Entity (Nam), Nam);
1159 Set_Etype (Nam, Etype (Entity (Nam)));
1161 Remove_Abstract_Operations (N);
1168 -----------------------------
1169 -- Analyze_Case_Expression --
1170 -----------------------------
1172 procedure Analyze_Case_Expression (N : Node_Id) is
1173 Expr : constant Node_Id := Expression (N);
1174 FirstX : constant Node_Id := Expression (First (Alternatives (N)));
1176 Exp_Type : Entity_Id;
1177 Exp_Btype : Entity_Id;
1179 Dont_Care : Boolean;
1180 Others_Present : Boolean;
1182 procedure Non_Static_Choice_Error (Choice : Node_Id);
1183 -- Error routine invoked by the generic instantiation below when
1184 -- the case expression has a non static choice.
1186 package Case_Choices_Processing is new
1187 Generic_Choices_Processing
1188 (Get_Alternatives => Alternatives,
1189 Get_Choices => Discrete_Choices,
1190 Process_Empty_Choice => No_OP,
1191 Process_Non_Static_Choice => Non_Static_Choice_Error,
1192 Process_Associated_Node => No_OP);
1193 use Case_Choices_Processing;
1195 -----------------------------
1196 -- Non_Static_Choice_Error --
1197 -----------------------------
1199 procedure Non_Static_Choice_Error (Choice : Node_Id) is
1201 Flag_Non_Static_Expr
1202 ("choice given in case expression is not static!", Choice);
1203 end Non_Static_Choice_Error;
1205 -- Start of processing for Analyze_Case_Expression
1208 if Comes_From_Source (N) then
1209 Check_Compiler_Unit (N);
1212 Analyze_And_Resolve (Expr, Any_Discrete);
1213 Check_Unset_Reference (Expr);
1214 Exp_Type := Etype (Expr);
1215 Exp_Btype := Base_Type (Exp_Type);
1217 Alt := First (Alternatives (N));
1218 while Present (Alt) loop
1219 Analyze (Expression (Alt));
1223 if not Is_Overloaded (FirstX) then
1224 Set_Etype (N, Etype (FirstX));
1232 Set_Etype (N, Any_Type);
1234 Get_First_Interp (FirstX, I, It);
1235 while Present (It.Nam) loop
1237 -- For each interpretation of the first expression, we only
1238 -- add the interpretation if every other expression in the
1239 -- case expression alternatives has a compatible type.
1241 Alt := Next (First (Alternatives (N)));
1242 while Present (Alt) loop
1243 exit when not Has_Compatible_Type (Expression (Alt), It.Typ);
1248 Add_One_Interp (N, It.Typ, It.Typ);
1251 Get_Next_Interp (I, It);
1256 Exp_Btype := Base_Type (Exp_Type);
1258 -- The expression must be of a discrete type which must be determinable
1259 -- independently of the context in which the expression occurs, but
1260 -- using the fact that the expression must be of a discrete type.
1261 -- Moreover, the type this expression must not be a character literal
1262 -- (which is always ambiguous).
1264 -- If error already reported by Resolve, nothing more to do
1266 if Exp_Btype = Any_Discrete
1267 or else Exp_Btype = Any_Type
1271 elsif Exp_Btype = Any_Character then
1273 ("character literal as case expression is ambiguous", Expr);
1277 -- If the case expression is a formal object of mode in out, then
1278 -- treat it as having a nonstatic subtype by forcing use of the base
1279 -- type (which has to get passed to Check_Case_Choices below). Also
1280 -- use base type when the case expression is parenthesized.
1282 if Paren_Count (Expr) > 0
1283 or else (Is_Entity_Name (Expr)
1284 and then Ekind (Entity (Expr)) = E_Generic_In_Out_Parameter)
1286 Exp_Type := Exp_Btype;
1289 -- Call instantiated Analyze_Choices which does the rest of the work
1291 Analyze_Choices (N, Exp_Type, Dont_Care, Others_Present);
1293 if Exp_Type = Universal_Integer and then not Others_Present then
1295 ("case on universal integer requires OTHERS choice", Expr);
1297 end Analyze_Case_Expression;
1299 ---------------------------
1300 -- Analyze_Comparison_Op --
1301 ---------------------------
1303 procedure Analyze_Comparison_Op (N : Node_Id) is
1304 L : constant Node_Id := Left_Opnd (N);
1305 R : constant Node_Id := Right_Opnd (N);
1306 Op_Id : Entity_Id := Entity (N);
1309 Set_Etype (N, Any_Type);
1310 Candidate_Type := Empty;
1312 Analyze_Expression (L);
1313 Analyze_Expression (R);
1315 if Present (Op_Id) then
1316 if Ekind (Op_Id) = E_Operator then
1317 Find_Comparison_Types (L, R, Op_Id, N);
1319 Add_One_Interp (N, Op_Id, Etype (Op_Id));
1322 if Is_Overloaded (L) then
1323 Set_Etype (L, Intersect_Types (L, R));
1327 Op_Id := Get_Name_Entity_Id (Chars (N));
1328 while Present (Op_Id) loop
1329 if Ekind (Op_Id) = E_Operator then
1330 Find_Comparison_Types (L, R, Op_Id, N);
1332 Analyze_User_Defined_Binary_Op (N, Op_Id);
1335 Op_Id := Homonym (Op_Id);
1340 end Analyze_Comparison_Op;
1342 ---------------------------
1343 -- Analyze_Concatenation --
1344 ---------------------------
1346 procedure Analyze_Concatenation (N : Node_Id) is
1348 -- We wish to avoid deep recursion, because concatenations are often
1349 -- deeply nested, as in A&B&...&Z. Therefore, we walk down the left
1350 -- operands nonrecursively until we find something that is not a
1351 -- concatenation (A in this case), or has already been analyzed. We
1352 -- analyze that, and then walk back up the tree following Parent
1353 -- pointers, calling Analyze_Concatenation_Rest to do the rest of the
1354 -- work at each level. The Parent pointers allow us to avoid recursion,
1355 -- and thus avoid running out of memory.
1361 Candidate_Type := Empty;
1363 -- The following code is equivalent to:
1365 -- Set_Etype (N, Any_Type);
1366 -- Analyze_Expression (Left_Opnd (N));
1367 -- Analyze_Concatenation_Rest (N);
1369 -- where the Analyze_Expression call recurses back here if the left
1370 -- operand is a concatenation.
1372 -- Walk down left operands
1375 Set_Etype (NN, Any_Type);
1376 L := Left_Opnd (NN);
1377 exit when Nkind (L) /= N_Op_Concat or else Analyzed (L);
1381 -- Now (given the above example) NN is A&B and L is A
1383 -- First analyze L ...
1385 Analyze_Expression (L);
1387 -- ... then walk NN back up until we reach N (where we started), calling
1388 -- Analyze_Concatenation_Rest along the way.
1391 Analyze_Concatenation_Rest (NN);
1395 end Analyze_Concatenation;
1397 --------------------------------
1398 -- Analyze_Concatenation_Rest --
1399 --------------------------------
1401 -- If the only one-dimensional array type in scope is String,
1402 -- this is the resulting type of the operation. Otherwise there
1403 -- will be a concatenation operation defined for each user-defined
1404 -- one-dimensional array.
1406 procedure Analyze_Concatenation_Rest (N : Node_Id) is
1407 L : constant Node_Id := Left_Opnd (N);
1408 R : constant Node_Id := Right_Opnd (N);
1409 Op_Id : Entity_Id := Entity (N);
1414 Analyze_Expression (R);
1416 -- If the entity is present, the node appears in an instance, and
1417 -- denotes a predefined concatenation operation. The resulting type is
1418 -- obtained from the arguments when possible. If the arguments are
1419 -- aggregates, the array type and the concatenation type must be
1422 if Present (Op_Id) then
1423 if Ekind (Op_Id) = E_Operator then
1424 LT := Base_Type (Etype (L));
1425 RT := Base_Type (Etype (R));
1427 if Is_Array_Type (LT)
1428 and then (RT = LT or else RT = Base_Type (Component_Type (LT)))
1430 Add_One_Interp (N, Op_Id, LT);
1432 elsif Is_Array_Type (RT)
1433 and then LT = Base_Type (Component_Type (RT))
1435 Add_One_Interp (N, Op_Id, RT);
1437 -- If one operand is a string type or a user-defined array type,
1438 -- and the other is a literal, result is of the specific type.
1441 (Root_Type (LT) = Standard_String
1442 or else Scope (LT) /= Standard_Standard)
1443 and then Etype (R) = Any_String
1445 Add_One_Interp (N, Op_Id, LT);
1448 (Root_Type (RT) = Standard_String
1449 or else Scope (RT) /= Standard_Standard)
1450 and then Etype (L) = Any_String
1452 Add_One_Interp (N, Op_Id, RT);
1454 elsif not Is_Generic_Type (Etype (Op_Id)) then
1455 Add_One_Interp (N, Op_Id, Etype (Op_Id));
1458 -- Type and its operations must be visible
1460 Set_Entity (N, Empty);
1461 Analyze_Concatenation (N);
1465 Add_One_Interp (N, Op_Id, Etype (Op_Id));
1469 Op_Id := Get_Name_Entity_Id (Name_Op_Concat);
1470 while Present (Op_Id) loop
1471 if Ekind (Op_Id) = E_Operator then
1473 -- Do not consider operators declared in dead code, they can
1474 -- not be part of the resolution.
1476 if Is_Eliminated (Op_Id) then
1479 Find_Concatenation_Types (L, R, Op_Id, N);
1483 Analyze_User_Defined_Binary_Op (N, Op_Id);
1486 Op_Id := Homonym (Op_Id);
1491 end Analyze_Concatenation_Rest;
1493 ------------------------------------
1494 -- Analyze_Conditional_Expression --
1495 ------------------------------------
1497 procedure Analyze_Conditional_Expression (N : Node_Id) is
1498 Condition : constant Node_Id := First (Expressions (N));
1499 Then_Expr : constant Node_Id := Next (Condition);
1500 Else_Expr : Node_Id;
1503 -- Defend against error of missing expressions from previous error
1505 if No (Then_Expr) then
1509 Check_Formal_Restriction ("conditional expression is not allowed", N);
1511 Else_Expr := Next (Then_Expr);
1513 if Comes_From_Source (N) then
1514 Check_Compiler_Unit (N);
1517 Analyze_Expression (Condition);
1518 Analyze_Expression (Then_Expr);
1520 if Present (Else_Expr) then
1521 Analyze_Expression (Else_Expr);
1524 -- If then expression not overloaded, then that decides the type
1526 if not Is_Overloaded (Then_Expr) then
1527 Set_Etype (N, Etype (Then_Expr));
1529 -- Case where then expression is overloaded
1537 Set_Etype (N, Any_Type);
1539 -- Shouldn't the following statement be down in the ELSE of the
1540 -- following loop? ???
1542 Get_First_Interp (Then_Expr, I, It);
1544 -- if no Else_Expression the conditional must be boolean
1546 if No (Else_Expr) then
1547 Set_Etype (N, Standard_Boolean);
1549 -- Else_Expression Present. For each possible intepretation of
1550 -- the Then_Expression, add it only if the Else_Expression has
1551 -- a compatible type.
1554 while Present (It.Nam) loop
1555 if Has_Compatible_Type (Else_Expr, It.Typ) then
1556 Add_One_Interp (N, It.Typ, It.Typ);
1559 Get_Next_Interp (I, It);
1564 end Analyze_Conditional_Expression;
1566 -------------------------
1567 -- Analyze_Equality_Op --
1568 -------------------------
1570 procedure Analyze_Equality_Op (N : Node_Id) is
1571 Loc : constant Source_Ptr := Sloc (N);
1572 L : constant Node_Id := Left_Opnd (N);
1573 R : constant Node_Id := Right_Opnd (N);
1577 Set_Etype (N, Any_Type);
1578 Candidate_Type := Empty;
1580 Analyze_Expression (L);
1581 Analyze_Expression (R);
1583 -- If the entity is set, the node is a generic instance with a non-local
1584 -- reference to the predefined operator or to a user-defined function.
1585 -- It can also be an inequality that is expanded into the negation of a
1586 -- call to a user-defined equality operator.
1588 -- For the predefined case, the result is Boolean, regardless of the
1589 -- type of the operands. The operands may even be limited, if they are
1590 -- generic actuals. If they are overloaded, label the left argument with
1591 -- the common type that must be present, or with the type of the formal
1592 -- of the user-defined function.
1594 if Present (Entity (N)) then
1595 Op_Id := Entity (N);
1597 if Ekind (Op_Id) = E_Operator then
1598 Add_One_Interp (N, Op_Id, Standard_Boolean);
1600 Add_One_Interp (N, Op_Id, Etype (Op_Id));
1603 if Is_Overloaded (L) then
1604 if Ekind (Op_Id) = E_Operator then
1605 Set_Etype (L, Intersect_Types (L, R));
1607 Set_Etype (L, Etype (First_Formal (Op_Id)));
1612 Op_Id := Get_Name_Entity_Id (Chars (N));
1613 while Present (Op_Id) loop
1614 if Ekind (Op_Id) = E_Operator then
1615 Find_Equality_Types (L, R, Op_Id, N);
1617 Analyze_User_Defined_Binary_Op (N, Op_Id);
1620 Op_Id := Homonym (Op_Id);
1624 -- If there was no match, and the operator is inequality, this may
1625 -- be a case where inequality has not been made explicit, as for
1626 -- tagged types. Analyze the node as the negation of an equality
1627 -- operation. This cannot be done earlier, because before analysis
1628 -- we cannot rule out the presence of an explicit inequality.
1630 if Etype (N) = Any_Type
1631 and then Nkind (N) = N_Op_Ne
1633 Op_Id := Get_Name_Entity_Id (Name_Op_Eq);
1634 while Present (Op_Id) loop
1635 if Ekind (Op_Id) = E_Operator then
1636 Find_Equality_Types (L, R, Op_Id, N);
1638 Analyze_User_Defined_Binary_Op (N, Op_Id);
1641 Op_Id := Homonym (Op_Id);
1644 if Etype (N) /= Any_Type then
1645 Op_Id := Entity (N);
1651 Left_Opnd => Left_Opnd (N),
1652 Right_Opnd => Right_Opnd (N))));
1654 Set_Entity (Right_Opnd (N), Op_Id);
1660 end Analyze_Equality_Op;
1662 ----------------------------------
1663 -- Analyze_Explicit_Dereference --
1664 ----------------------------------
1666 procedure Analyze_Explicit_Dereference (N : Node_Id) is
1667 Loc : constant Source_Ptr := Sloc (N);
1668 P : constant Node_Id := Prefix (N);
1674 function Is_Function_Type return Boolean;
1675 -- Check whether node may be interpreted as an implicit function call
1677 ----------------------
1678 -- Is_Function_Type --
1679 ----------------------
1681 function Is_Function_Type return Boolean is
1686 if not Is_Overloaded (N) then
1687 return Ekind (Base_Type (Etype (N))) = E_Subprogram_Type
1688 and then Etype (Base_Type (Etype (N))) /= Standard_Void_Type;
1691 Get_First_Interp (N, I, It);
1692 while Present (It.Nam) loop
1693 if Ekind (Base_Type (It.Typ)) /= E_Subprogram_Type
1694 or else Etype (Base_Type (It.Typ)) = Standard_Void_Type
1699 Get_Next_Interp (I, It);
1704 end Is_Function_Type;
1706 -- Start of processing for Analyze_Explicit_Dereference
1709 Check_Formal_Restriction ("explicit dereference is not allowed", N);
1712 Set_Etype (N, Any_Type);
1714 -- Test for remote access to subprogram type, and if so return
1715 -- after rewriting the original tree.
1717 if Remote_AST_E_Dereference (P) then
1721 -- Normal processing for other than remote access to subprogram type
1723 if not Is_Overloaded (P) then
1724 if Is_Access_Type (Etype (P)) then
1726 -- Set the Etype. We need to go through Is_For_Access_Subtypes to
1727 -- avoid other problems caused by the Private_Subtype and it is
1728 -- safe to go to the Base_Type because this is the same as
1729 -- converting the access value to its Base_Type.
1732 DT : Entity_Id := Designated_Type (Etype (P));
1735 if Ekind (DT) = E_Private_Subtype
1736 and then Is_For_Access_Subtype (DT)
1738 DT := Base_Type (DT);
1741 -- An explicit dereference is a legal occurrence of an
1742 -- incomplete type imported through a limited_with clause,
1743 -- if the full view is visible.
1745 if From_With_Type (DT)
1746 and then not From_With_Type (Scope (DT))
1748 (Is_Immediately_Visible (Scope (DT))
1750 (Is_Child_Unit (Scope (DT))
1751 and then Is_Visible_Child_Unit (Scope (DT))))
1753 Set_Etype (N, Available_View (DT));
1760 elsif Etype (P) /= Any_Type then
1761 Error_Msg_N ("prefix of dereference must be an access type", N);
1766 Get_First_Interp (P, I, It);
1767 while Present (It.Nam) loop
1770 if Is_Access_Type (T) then
1771 Add_One_Interp (N, Designated_Type (T), Designated_Type (T));
1774 Get_Next_Interp (I, It);
1777 -- Error if no interpretation of the prefix has an access type
1779 if Etype (N) = Any_Type then
1781 ("access type required in prefix of explicit dereference", P);
1782 Set_Etype (N, Any_Type);
1788 and then Nkind (Parent (N)) /= N_Indexed_Component
1790 and then (Nkind (Parent (N)) /= N_Function_Call
1791 or else N /= Name (Parent (N)))
1793 and then (Nkind (Parent (N)) /= N_Procedure_Call_Statement
1794 or else N /= Name (Parent (N)))
1796 and then Nkind (Parent (N)) /= N_Subprogram_Renaming_Declaration
1797 and then (Nkind (Parent (N)) /= N_Attribute_Reference
1799 (Attribute_Name (Parent (N)) /= Name_Address
1801 Attribute_Name (Parent (N)) /= Name_Access))
1803 -- Name is a function call with no actuals, in a context that
1804 -- requires deproceduring (including as an actual in an enclosing
1805 -- function or procedure call). There are some pathological cases
1806 -- where the prefix might include functions that return access to
1807 -- subprograms and others that return a regular type. Disambiguation
1808 -- of those has to take place in Resolve.
1811 Make_Function_Call (Loc,
1812 Name => Make_Explicit_Dereference (Loc, P),
1813 Parameter_Associations => New_List);
1815 -- If the prefix is overloaded, remove operations that have formals,
1816 -- we know that this is a parameterless call.
1818 if Is_Overloaded (P) then
1819 Get_First_Interp (P, I, It);
1820 while Present (It.Nam) loop
1823 if No (First_Formal (Base_Type (Designated_Type (T)))) then
1829 Get_Next_Interp (I, It);
1836 elsif not Is_Function_Type
1837 and then Is_Overloaded (N)
1839 -- The prefix may include access to subprograms and other access
1840 -- types. If the context selects the interpretation that is a
1841 -- function call (not a procedure call) we cannot rewrite the node
1842 -- yet, but we include the result of the call interpretation.
1844 Get_First_Interp (N, I, It);
1845 while Present (It.Nam) loop
1846 if Ekind (Base_Type (It.Typ)) = E_Subprogram_Type
1847 and then Etype (Base_Type (It.Typ)) /= Standard_Void_Type
1848 and then Nkind (Parent (N)) /= N_Procedure_Call_Statement
1850 Add_One_Interp (N, Etype (It.Typ), Etype (It.Typ));
1853 Get_Next_Interp (I, It);
1857 -- A value of remote access-to-class-wide must not be dereferenced
1860 Validate_Remote_Access_To_Class_Wide_Type (N);
1861 end Analyze_Explicit_Dereference;
1863 ------------------------
1864 -- Analyze_Expression --
1865 ------------------------
1867 procedure Analyze_Expression (N : Node_Id) is
1870 Check_Parameterless_Call (N);
1871 end Analyze_Expression;
1873 -------------------------------------
1874 -- Analyze_Expression_With_Actions --
1875 -------------------------------------
1877 procedure Analyze_Expression_With_Actions (N : Node_Id) is
1881 A := First (Actions (N));
1888 Analyze_Expression (Expression (N));
1889 Set_Etype (N, Etype (Expression (N)));
1890 end Analyze_Expression_With_Actions;
1892 ------------------------------------
1893 -- Analyze_Indexed_Component_Form --
1894 ------------------------------------
1896 procedure Analyze_Indexed_Component_Form (N : Node_Id) is
1897 P : constant Node_Id := Prefix (N);
1898 Exprs : constant List_Id := Expressions (N);
1904 procedure Process_Function_Call;
1905 -- Prefix in indexed component form is an overloadable entity,
1906 -- so the node is a function call. Reformat it as such.
1908 procedure Process_Indexed_Component;
1909 -- Prefix in indexed component form is actually an indexed component.
1910 -- This routine processes it, knowing that the prefix is already
1913 procedure Process_Indexed_Component_Or_Slice;
1914 -- An indexed component with a single index may designate a slice if
1915 -- the index is a subtype mark. This routine disambiguates these two
1916 -- cases by resolving the prefix to see if it is a subtype mark.
1918 procedure Process_Overloaded_Indexed_Component;
1919 -- If the prefix of an indexed component is overloaded, the proper
1920 -- interpretation is selected by the index types and the context.
1922 ---------------------------
1923 -- Process_Function_Call --
1924 ---------------------------
1926 procedure Process_Function_Call is
1930 Change_Node (N, N_Function_Call);
1932 Set_Parameter_Associations (N, Exprs);
1934 -- Analyze actuals prior to analyzing the call itself
1936 Actual := First (Parameter_Associations (N));
1937 while Present (Actual) loop
1939 Check_Parameterless_Call (Actual);
1941 -- Move to next actual. Note that we use Next, not Next_Actual
1942 -- here. The reason for this is a bit subtle. If a function call
1943 -- includes named associations, the parser recognizes the node as
1944 -- a call, and it is analyzed as such. If all associations are
1945 -- positional, the parser builds an indexed_component node, and
1946 -- it is only after analysis of the prefix that the construct
1947 -- is recognized as a call, in which case Process_Function_Call
1948 -- rewrites the node and analyzes the actuals. If the list of
1949 -- actuals is malformed, the parser may leave the node as an
1950 -- indexed component (despite the presence of named associations).
1951 -- The iterator Next_Actual is equivalent to Next if the list is
1952 -- positional, but follows the normalized chain of actuals when
1953 -- named associations are present. In this case normalization has
1954 -- not taken place, and actuals remain unanalyzed, which leads to
1955 -- subsequent crashes or loops if there is an attempt to continue
1956 -- analysis of the program.
1962 end Process_Function_Call;
1964 -------------------------------
1965 -- Process_Indexed_Component --
1966 -------------------------------
1968 procedure Process_Indexed_Component is
1970 Array_Type : Entity_Id;
1972 Pent : Entity_Id := Empty;
1975 Exp := First (Exprs);
1977 if Is_Overloaded (P) then
1978 Process_Overloaded_Indexed_Component;
1981 Array_Type := Etype (P);
1983 if Is_Entity_Name (P) then
1985 elsif Nkind (P) = N_Selected_Component
1986 and then Is_Entity_Name (Selector_Name (P))
1988 Pent := Entity (Selector_Name (P));
1991 -- Prefix must be appropriate for an array type, taking into
1992 -- account a possible implicit dereference.
1994 if Is_Access_Type (Array_Type) then
1995 Error_Msg_NW (Warn_On_Dereference, "?implicit dereference", N);
1996 Array_Type := Process_Implicit_Dereference_Prefix (Pent, P);
1999 if Is_Array_Type (Array_Type) then
2002 elsif Present (Pent) and then Ekind (Pent) = E_Entry_Family then
2004 Set_Etype (N, Any_Type);
2006 if not Has_Compatible_Type
2007 (Exp, Entry_Index_Type (Pent))
2009 Error_Msg_N ("invalid index type in entry name", N);
2011 elsif Present (Next (Exp)) then
2012 Error_Msg_N ("too many subscripts in entry reference", N);
2015 Set_Etype (N, Etype (P));
2020 elsif Is_Record_Type (Array_Type)
2021 and then Remote_AST_I_Dereference (P)
2025 elsif Array_Type = Any_Type then
2026 Set_Etype (N, Any_Type);
2028 -- In most cases the analysis of the prefix will have emitted
2029 -- an error already, but if the prefix may be interpreted as a
2030 -- call in prefixed notation, the report is left to the caller.
2031 -- To prevent cascaded errors, report only if no previous ones.
2033 if Serious_Errors_Detected = 0 then
2034 Error_Msg_N ("invalid prefix in indexed component", P);
2036 if Nkind (P) = N_Expanded_Name then
2037 Error_Msg_NE ("\& is not visible", P, Selector_Name (P));
2043 -- Here we definitely have a bad indexing
2046 if Nkind (Parent (N)) = N_Requeue_Statement
2047 and then Present (Pent) and then Ekind (Pent) = E_Entry
2050 ("REQUEUE does not permit parameters", First (Exprs));
2052 elsif Is_Entity_Name (P)
2053 and then Etype (P) = Standard_Void_Type
2055 Error_Msg_NE ("incorrect use of&", P, Entity (P));
2058 Error_Msg_N ("array type required in indexed component", P);
2061 Set_Etype (N, Any_Type);
2065 Index := First_Index (Array_Type);
2066 while Present (Index) and then Present (Exp) loop
2067 if not Has_Compatible_Type (Exp, Etype (Index)) then
2068 Wrong_Type (Exp, Etype (Index));
2069 Set_Etype (N, Any_Type);
2077 Set_Etype (N, Component_Type (Array_Type));
2079 if Present (Index) then
2081 ("too few subscripts in array reference", First (Exprs));
2083 elsif Present (Exp) then
2084 Error_Msg_N ("too many subscripts in array reference", Exp);
2087 end Process_Indexed_Component;
2089 ----------------------------------------
2090 -- Process_Indexed_Component_Or_Slice --
2091 ----------------------------------------
2093 procedure Process_Indexed_Component_Or_Slice is
2095 Exp := First (Exprs);
2096 while Present (Exp) loop
2097 Analyze_Expression (Exp);
2101 Exp := First (Exprs);
2103 -- If one index is present, and it is a subtype name, then the
2104 -- node denotes a slice (note that the case of an explicit range
2105 -- for a slice was already built as an N_Slice node in the first
2106 -- place, so that case is not handled here).
2108 -- We use a replace rather than a rewrite here because this is one
2109 -- of the cases in which the tree built by the parser is plain wrong.
2112 and then Is_Entity_Name (Exp)
2113 and then Is_Type (Entity (Exp))
2116 Make_Slice (Sloc (N),
2118 Discrete_Range => New_Copy (Exp)));
2121 -- Otherwise (more than one index present, or single index is not
2122 -- a subtype name), then we have the indexed component case.
2125 Process_Indexed_Component;
2127 end Process_Indexed_Component_Or_Slice;
2129 ------------------------------------------
2130 -- Process_Overloaded_Indexed_Component --
2131 ------------------------------------------
2133 procedure Process_Overloaded_Indexed_Component is
2142 Set_Etype (N, Any_Type);
2144 Get_First_Interp (P, I, It);
2145 while Present (It.Nam) loop
2148 if Is_Access_Type (Typ) then
2149 Typ := Designated_Type (Typ);
2150 Error_Msg_NW (Warn_On_Dereference, "?implicit dereference", N);
2153 if Is_Array_Type (Typ) then
2155 -- Got a candidate: verify that index types are compatible
2157 Index := First_Index (Typ);
2159 Exp := First (Exprs);
2160 while Present (Index) and then Present (Exp) loop
2161 if Has_Compatible_Type (Exp, Etype (Index)) then
2173 if Found and then No (Index) and then No (Exp) then
2175 Etype (Component_Type (Typ)),
2176 Etype (Component_Type (Typ)));
2180 Get_Next_Interp (I, It);
2183 if Etype (N) = Any_Type then
2184 Error_Msg_N ("no legal interpretation for indexed component", N);
2185 Set_Is_Overloaded (N, False);
2189 end Process_Overloaded_Indexed_Component;
2191 -- Start of processing for Analyze_Indexed_Component_Form
2194 -- Get name of array, function or type
2198 if Nkind_In (N, N_Function_Call, N_Procedure_Call_Statement) then
2200 -- If P is an explicit dereference whose prefix is of a
2201 -- remote access-to-subprogram type, then N has already
2202 -- been rewritten as a subprogram call and analyzed.
2207 pragma Assert (Nkind (N) = N_Indexed_Component);
2209 P_T := Base_Type (Etype (P));
2211 if Is_Entity_Name (P) and then Present (Entity (P)) then
2214 if Is_Type (U_N) then
2216 -- Reformat node as a type conversion
2218 E := Remove_Head (Exprs);
2220 if Present (First (Exprs)) then
2222 ("argument of type conversion must be single expression", N);
2225 Change_Node (N, N_Type_Conversion);
2226 Set_Subtype_Mark (N, P);
2228 Set_Expression (N, E);
2230 -- After changing the node, call for the specific Analysis
2231 -- routine directly, to avoid a double call to the expander.
2233 Analyze_Type_Conversion (N);
2237 if Is_Overloadable (U_N) then
2238 Process_Function_Call;
2240 elsif Ekind (Etype (P)) = E_Subprogram_Type
2241 or else (Is_Access_Type (Etype (P))
2243 Ekind (Designated_Type (Etype (P))) =
2246 -- Call to access_to-subprogram with possible implicit dereference
2248 Process_Function_Call;
2250 elsif Is_Generic_Subprogram (U_N) then
2252 -- A common beginner's (or C++ templates fan) error
2254 Error_Msg_N ("generic subprogram cannot be called", N);
2255 Set_Etype (N, Any_Type);
2259 Process_Indexed_Component_Or_Slice;
2262 -- If not an entity name, prefix is an expression that may denote
2263 -- an array or an access-to-subprogram.
2266 if Ekind (P_T) = E_Subprogram_Type
2267 or else (Is_Access_Type (P_T)
2269 Ekind (Designated_Type (P_T)) = E_Subprogram_Type)
2271 Process_Function_Call;
2273 elsif Nkind (P) = N_Selected_Component
2274 and then Is_Overloadable (Entity (Selector_Name (P)))
2276 Process_Function_Call;
2279 -- Indexed component, slice, or a call to a member of a family
2280 -- entry, which will be converted to an entry call later.
2282 Process_Indexed_Component_Or_Slice;
2285 end Analyze_Indexed_Component_Form;
2287 ------------------------
2288 -- Analyze_Logical_Op --
2289 ------------------------
2291 procedure Analyze_Logical_Op (N : Node_Id) is
2292 L : constant Node_Id := Left_Opnd (N);
2293 R : constant Node_Id := Right_Opnd (N);
2294 Op_Id : Entity_Id := Entity (N);
2297 Set_Etype (N, Any_Type);
2298 Candidate_Type := Empty;
2300 Analyze_Expression (L);
2301 Analyze_Expression (R);
2303 if Present (Op_Id) then
2305 if Ekind (Op_Id) = E_Operator then
2306 Find_Boolean_Types (L, R, Op_Id, N);
2308 Add_One_Interp (N, Op_Id, Etype (Op_Id));
2312 Op_Id := Get_Name_Entity_Id (Chars (N));
2313 while Present (Op_Id) loop
2314 if Ekind (Op_Id) = E_Operator then
2315 Find_Boolean_Types (L, R, Op_Id, N);
2317 Analyze_User_Defined_Binary_Op (N, Op_Id);
2320 Op_Id := Homonym (Op_Id);
2325 end Analyze_Logical_Op;
2327 ---------------------------
2328 -- Analyze_Membership_Op --
2329 ---------------------------
2331 procedure Analyze_Membership_Op (N : Node_Id) is
2332 Loc : constant Source_Ptr := Sloc (N);
2333 L : constant Node_Id := Left_Opnd (N);
2334 R : constant Node_Id := Right_Opnd (N);
2336 Index : Interp_Index;
2338 Found : Boolean := False;
2342 procedure Try_One_Interp (T1 : Entity_Id);
2343 -- Routine to try one proposed interpretation. Note that the context
2344 -- of the operation plays no role in resolving the arguments, so that
2345 -- if there is more than one interpretation of the operands that is
2346 -- compatible with a membership test, the operation is ambiguous.
2348 --------------------
2349 -- Try_One_Interp --
2350 --------------------
2352 procedure Try_One_Interp (T1 : Entity_Id) is
2354 if Has_Compatible_Type (R, T1) then
2356 and then Base_Type (T1) /= Base_Type (T_F)
2358 It := Disambiguate (L, I_F, Index, Any_Type);
2360 if It = No_Interp then
2361 Ambiguous_Operands (N);
2362 Set_Etype (L, Any_Type);
2379 procedure Analyze_Set_Membership;
2380 -- If a set of alternatives is present, analyze each and find the
2381 -- common type to which they must all resolve.
2383 ----------------------------
2384 -- Analyze_Set_Membership --
2385 ----------------------------
2387 procedure Analyze_Set_Membership is
2389 Index : Interp_Index;
2391 Candidate_Interps : Node_Id;
2392 Common_Type : Entity_Id := Empty;
2396 Candidate_Interps := L;
2398 if not Is_Overloaded (L) then
2399 Common_Type := Etype (L);
2401 Alt := First (Alternatives (N));
2402 while Present (Alt) loop
2405 if not Has_Compatible_Type (Alt, Common_Type) then
2406 Wrong_Type (Alt, Common_Type);
2413 Alt := First (Alternatives (N));
2414 while Present (Alt) loop
2416 if not Is_Overloaded (Alt) then
2417 Common_Type := Etype (Alt);
2420 Get_First_Interp (Alt, Index, It);
2421 while Present (It.Typ) loop
2423 Has_Compatible_Type (Candidate_Interps, It.Typ)
2425 Remove_Interp (Index);
2428 Get_Next_Interp (Index, It);
2431 Get_First_Interp (Alt, Index, It);
2434 Error_Msg_N ("alternative has no legal type", Alt);
2438 -- If alternative is not overloaded, we have a unique type
2441 Set_Etype (Alt, It.Typ);
2442 Get_Next_Interp (Index, It);
2445 Set_Is_Overloaded (Alt, False);
2446 Common_Type := Etype (Alt);
2449 Candidate_Interps := Alt;
2456 Set_Etype (N, Standard_Boolean);
2458 if Present (Common_Type) then
2459 Set_Etype (L, Common_Type);
2460 Set_Is_Overloaded (L, False);
2463 Error_Msg_N ("cannot resolve membership operation", N);
2465 end Analyze_Set_Membership;
2467 -- Start of processing for Analyze_Membership_Op
2470 Analyze_Expression (L);
2473 and then Ada_Version >= Ada_2012
2475 Analyze_Set_Membership;
2479 if Nkind (R) = N_Range
2480 or else (Nkind (R) = N_Attribute_Reference
2481 and then Attribute_Name (R) = Name_Range)
2485 if not Is_Overloaded (L) then
2486 Try_One_Interp (Etype (L));
2489 Get_First_Interp (L, Index, It);
2490 while Present (It.Typ) loop
2491 Try_One_Interp (It.Typ);
2492 Get_Next_Interp (Index, It);
2496 -- If not a range, it can be a subtype mark, or else it is a degenerate
2497 -- membership test with a singleton value, i.e. a test for equality,
2498 -- if the types are compatible.
2502 if Is_Entity_Name (R)
2503 and then Is_Type (Entity (R))
2506 Check_Fully_Declared (Entity (R), R);
2508 elsif Ada_Version >= Ada_2012
2509 and then Has_Compatible_Type (R, Etype (L))
2511 if Nkind (N) = N_In then
2527 -- In all versions of the language, if we reach this point there
2528 -- is a previous error that will be diagnosed below.
2534 -- Compatibility between expression and subtype mark or range is
2535 -- checked during resolution. The result of the operation is Boolean
2538 Set_Etype (N, Standard_Boolean);
2540 if Comes_From_Source (N)
2541 and then Present (Right_Opnd (N))
2542 and then Is_CPP_Class (Etype (Etype (Right_Opnd (N))))
2544 Error_Msg_N ("membership test not applicable to cpp-class types", N);
2546 end Analyze_Membership_Op;
2548 ----------------------
2549 -- Analyze_Negation --
2550 ----------------------
2552 procedure Analyze_Negation (N : Node_Id) is
2553 R : constant Node_Id := Right_Opnd (N);
2554 Op_Id : Entity_Id := Entity (N);
2557 Set_Etype (N, Any_Type);
2558 Candidate_Type := Empty;
2560 Analyze_Expression (R);
2562 if Present (Op_Id) then
2563 if Ekind (Op_Id) = E_Operator then
2564 Find_Negation_Types (R, Op_Id, N);
2566 Add_One_Interp (N, Op_Id, Etype (Op_Id));
2570 Op_Id := Get_Name_Entity_Id (Chars (N));
2571 while Present (Op_Id) loop
2572 if Ekind (Op_Id) = E_Operator then
2573 Find_Negation_Types (R, Op_Id, N);
2575 Analyze_User_Defined_Unary_Op (N, Op_Id);
2578 Op_Id := Homonym (Op_Id);
2583 end Analyze_Negation;
2589 procedure Analyze_Null (N : Node_Id) is
2591 Check_Formal_Restriction ("null is not allowed", N);
2593 Set_Etype (N, Any_Access);
2596 ----------------------
2597 -- Analyze_One_Call --
2598 ----------------------
2600 procedure Analyze_One_Call
2604 Success : out Boolean;
2605 Skip_First : Boolean := False)
2607 Actuals : constant List_Id := Parameter_Associations (N);
2608 Prev_T : constant Entity_Id := Etype (N);
2610 Must_Skip : constant Boolean := Skip_First
2611 or else Nkind (Original_Node (N)) = N_Selected_Component
2613 (Nkind (Original_Node (N)) = N_Indexed_Component
2614 and then Nkind (Prefix (Original_Node (N)))
2615 = N_Selected_Component);
2616 -- The first formal must be omitted from the match when trying to find
2617 -- a primitive operation that is a possible interpretation, and also
2618 -- after the call has been rewritten, because the corresponding actual
2619 -- is already known to be compatible, and because this may be an
2620 -- indexing of a call with default parameters.
2624 Is_Indexed : Boolean := False;
2625 Is_Indirect : Boolean := False;
2626 Subp_Type : constant Entity_Id := Etype (Nam);
2629 function Operator_Hidden_By (Fun : Entity_Id) return Boolean;
2630 -- There may be a user-defined operator that hides the current
2631 -- interpretation. We must check for this independently of the
2632 -- analysis of the call with the user-defined operation, because
2633 -- the parameter names may be wrong and yet the hiding takes place.
2634 -- This fixes a problem with ACATS test B34014O.
2636 -- When the type Address is a visible integer type, and the DEC
2637 -- system extension is visible, the predefined operator may be
2638 -- hidden as well, by one of the address operations in auxdec.
2639 -- Finally, The abstract operations on address do not hide the
2640 -- predefined operator (this is the purpose of making them abstract).
2642 procedure Indicate_Name_And_Type;
2643 -- If candidate interpretation matches, indicate name and type of
2644 -- result on call node.
2646 ----------------------------
2647 -- Indicate_Name_And_Type --
2648 ----------------------------
2650 procedure Indicate_Name_And_Type is
2652 Add_One_Interp (N, Nam, Etype (Nam));
2655 -- If the prefix of the call is a name, indicate the entity
2656 -- being called. If it is not a name, it is an expression that
2657 -- denotes an access to subprogram or else an entry or family. In
2658 -- the latter case, the name is a selected component, and the entity
2659 -- being called is noted on the selector.
2661 if not Is_Type (Nam) then
2662 if Is_Entity_Name (Name (N)) then
2663 Set_Entity (Name (N), Nam);
2665 elsif Nkind (Name (N)) = N_Selected_Component then
2666 Set_Entity (Selector_Name (Name (N)), Nam);
2670 if Debug_Flag_E and not Report then
2671 Write_Str (" Overloaded call ");
2672 Write_Int (Int (N));
2673 Write_Str (" compatible with ");
2674 Write_Int (Int (Nam));
2677 end Indicate_Name_And_Type;
2679 ------------------------
2680 -- Operator_Hidden_By --
2681 ------------------------
2683 function Operator_Hidden_By (Fun : Entity_Id) return Boolean is
2684 Act1 : constant Node_Id := First_Actual (N);
2685 Act2 : constant Node_Id := Next_Actual (Act1);
2686 Form1 : constant Entity_Id := First_Formal (Fun);
2687 Form2 : constant Entity_Id := Next_Formal (Form1);
2690 if Ekind (Fun) /= E_Function
2691 or else Is_Abstract_Subprogram (Fun)
2695 elsif not Has_Compatible_Type (Act1, Etype (Form1)) then
2698 elsif Present (Form2) then
2700 No (Act2) or else not Has_Compatible_Type (Act2, Etype (Form2))
2705 elsif Present (Act2) then
2709 -- Now we know that the arity of the operator matches the function,
2710 -- and the function call is a valid interpretation. The function
2711 -- hides the operator if it has the right signature, or if one of
2712 -- its operands is a non-abstract operation on Address when this is
2713 -- a visible integer type.
2715 return Hides_Op (Fun, Nam)
2716 or else Is_Descendent_Of_Address (Etype (Form1))
2719 and then Is_Descendent_Of_Address (Etype (Form2)));
2720 end Operator_Hidden_By;
2722 -- Start of processing for Analyze_One_Call
2727 -- If the subprogram has no formals or if all the formals have defaults,
2728 -- and the return type is an array type, the node may denote an indexing
2729 -- of the result of a parameterless call. In Ada 2005, the subprogram
2730 -- may have one non-defaulted formal, and the call may have been written
2731 -- in prefix notation, so that the rebuilt parameter list has more than
2734 if not Is_Overloadable (Nam)
2735 and then Ekind (Nam) /= E_Subprogram_Type
2736 and then Ekind (Nam) /= E_Entry_Family
2741 -- An indexing requires at least one actual
2743 if not Is_Empty_List (Actuals)
2745 (Needs_No_Actuals (Nam)
2747 (Needs_One_Actual (Nam)
2748 and then Present (Next_Actual (First (Actuals)))))
2750 if Is_Array_Type (Subp_Type) then
2751 Is_Indexed := Try_Indexed_Call (N, Nam, Subp_Type, Must_Skip);
2753 elsif Is_Access_Type (Subp_Type)
2754 and then Is_Array_Type (Designated_Type (Subp_Type))
2758 (N, Nam, Designated_Type (Subp_Type), Must_Skip);
2760 -- The prefix can also be a parameterless function that returns an
2761 -- access to subprogram, in which case this is an indirect call.
2762 -- If this succeeds, an explicit dereference is added later on,
2763 -- in Analyze_Call or Resolve_Call.
2765 elsif Is_Access_Type (Subp_Type)
2766 and then Ekind (Designated_Type (Subp_Type)) = E_Subprogram_Type
2768 Is_Indirect := Try_Indirect_Call (N, Nam, Subp_Type);
2773 -- If the call has been transformed into a slice, it is of the form
2774 -- F (Subtype) where F is parameterless. The node has been rewritten in
2775 -- Try_Indexed_Call and there is nothing else to do.
2778 and then Nkind (N) = N_Slice
2784 (N, Nam, (Report and not Is_Indexed and not Is_Indirect), Norm_OK);
2788 -- If an indirect call is a possible interpretation, indicate
2789 -- success to the caller.
2795 -- Mismatch in number or names of parameters
2797 elsif Debug_Flag_E then
2798 Write_Str (" normalization fails in call ");
2799 Write_Int (Int (N));
2800 Write_Str (" with subprogram ");
2801 Write_Int (Int (Nam));
2805 -- If the context expects a function call, discard any interpretation
2806 -- that is a procedure. If the node is not overloaded, leave as is for
2807 -- better error reporting when type mismatch is found.
2809 elsif Nkind (N) = N_Function_Call
2810 and then Is_Overloaded (Name (N))
2811 and then Ekind (Nam) = E_Procedure
2815 -- Ditto for function calls in a procedure context
2817 elsif Nkind (N) = N_Procedure_Call_Statement
2818 and then Is_Overloaded (Name (N))
2819 and then Etype (Nam) /= Standard_Void_Type
2823 elsif No (Actuals) then
2825 -- If Normalize succeeds, then there are default parameters for
2828 Indicate_Name_And_Type;
2830 elsif Ekind (Nam) = E_Operator then
2831 if Nkind (N) = N_Procedure_Call_Statement then
2835 -- This can occur when the prefix of the call is an operator
2836 -- name or an expanded name whose selector is an operator name.
2838 Analyze_Operator_Call (N, Nam);
2840 if Etype (N) /= Prev_T then
2842 -- Check that operator is not hidden by a function interpretation
2844 if Is_Overloaded (Name (N)) then
2850 Get_First_Interp (Name (N), I, It);
2851 while Present (It.Nam) loop
2852 if Operator_Hidden_By (It.Nam) then
2853 Set_Etype (N, Prev_T);
2857 Get_Next_Interp (I, It);
2862 -- If operator matches formals, record its name on the call.
2863 -- If the operator is overloaded, Resolve will select the
2864 -- correct one from the list of interpretations. The call
2865 -- node itself carries the first candidate.
2867 Set_Entity (Name (N), Nam);
2870 elsif Report and then Etype (N) = Any_Type then
2871 Error_Msg_N ("incompatible arguments for operator", N);
2875 -- Normalize_Actuals has chained the named associations in the
2876 -- correct order of the formals.
2878 Actual := First_Actual (N);
2879 Formal := First_Formal (Nam);
2881 -- If we are analyzing a call rewritten from object notation,
2882 -- skip first actual, which may be rewritten later as an
2883 -- explicit dereference.
2886 Next_Actual (Actual);
2887 Next_Formal (Formal);
2890 while Present (Actual) and then Present (Formal) loop
2891 if Nkind (Parent (Actual)) /= N_Parameter_Association
2892 or else Chars (Selector_Name (Parent (Actual))) = Chars (Formal)
2894 -- The actual can be compatible with the formal, but we must
2895 -- also check that the context is not an address type that is
2896 -- visibly an integer type, as is the case in VMS_64. In this
2897 -- case the use of literals is illegal, except in the body of
2898 -- descendents of system, where arithmetic operations on
2899 -- address are of course used.
2901 if Has_Compatible_Type (Actual, Etype (Formal))
2903 (Etype (Actual) /= Universal_Integer
2904 or else not Is_Descendent_Of_Address (Etype (Formal))
2906 Is_Predefined_File_Name
2907 (Unit_File_Name (Get_Source_Unit (N))))
2909 Next_Actual (Actual);
2910 Next_Formal (Formal);
2913 if Debug_Flag_E then
2914 Write_Str (" type checking fails in call ");
2915 Write_Int (Int (N));
2916 Write_Str (" with formal ");
2917 Write_Int (Int (Formal));
2918 Write_Str (" in subprogram ");
2919 Write_Int (Int (Nam));
2923 if Report and not Is_Indexed and not Is_Indirect then
2925 -- Ada 2005 (AI-251): Complete the error notification
2926 -- to help new Ada 2005 users.
2928 if Is_Class_Wide_Type (Etype (Formal))
2929 and then Is_Interface (Etype (Etype (Formal)))
2930 and then not Interface_Present_In_Ancestor
2931 (Typ => Etype (Actual),
2932 Iface => Etype (Etype (Formal)))
2935 ("(Ada 2005) does not implement interface }",
2936 Actual, Etype (Etype (Formal)));
2939 Wrong_Type (Actual, Etype (Formal));
2941 if Nkind (Actual) = N_Op_Eq
2942 and then Nkind (Left_Opnd (Actual)) = N_Identifier
2944 Formal := First_Formal (Nam);
2945 while Present (Formal) loop
2946 if Chars (Left_Opnd (Actual)) = Chars (Formal) then
2947 Error_Msg_N -- CODEFIX
2948 ("possible misspelling of `='>`!", Actual);
2952 Next_Formal (Formal);
2956 if All_Errors_Mode then
2957 Error_Msg_Sloc := Sloc (Nam);
2959 if Etype (Formal) = Any_Type then
2961 ("there is no legal actual parameter", Actual);
2964 if Is_Overloadable (Nam)
2965 and then Present (Alias (Nam))
2966 and then not Comes_From_Source (Nam)
2969 ("\\ =='> in call to inherited operation & #!",
2972 elsif Ekind (Nam) = E_Subprogram_Type then
2974 Access_To_Subprogram_Typ :
2975 constant Entity_Id :=
2977 (Associated_Node_For_Itype (Nam));
2980 "\\ =='> in call to dereference of &#!",
2981 Actual, Access_To_Subprogram_Typ);
2986 ("\\ =='> in call to &#!", Actual, Nam);
2996 -- Normalize_Actuals has verified that a default value exists
2997 -- for this formal. Current actual names a subsequent formal.
2999 Next_Formal (Formal);
3003 -- On exit, all actuals match
3005 Indicate_Name_And_Type;
3007 end Analyze_One_Call;
3009 ---------------------------
3010 -- Analyze_Operator_Call --
3011 ---------------------------
3013 procedure Analyze_Operator_Call (N : Node_Id; Op_Id : Entity_Id) is
3014 Op_Name : constant Name_Id := Chars (Op_Id);
3015 Act1 : constant Node_Id := First_Actual (N);
3016 Act2 : constant Node_Id := Next_Actual (Act1);
3019 -- Binary operator case
3021 if Present (Act2) then
3023 -- If more than two operands, then not binary operator after all
3025 if Present (Next_Actual (Act2)) then
3028 elsif Op_Name = Name_Op_Add
3029 or else Op_Name = Name_Op_Subtract
3030 or else Op_Name = Name_Op_Multiply
3031 or else Op_Name = Name_Op_Divide
3032 or else Op_Name = Name_Op_Mod
3033 or else Op_Name = Name_Op_Rem
3034 or else Op_Name = Name_Op_Expon
3036 Find_Arithmetic_Types (Act1, Act2, Op_Id, N);
3038 elsif Op_Name = Name_Op_And
3039 or else Op_Name = Name_Op_Or
3040 or else Op_Name = Name_Op_Xor
3042 Find_Boolean_Types (Act1, Act2, Op_Id, N);
3044 elsif Op_Name = Name_Op_Lt
3045 or else Op_Name = Name_Op_Le
3046 or else Op_Name = Name_Op_Gt
3047 or else Op_Name = Name_Op_Ge
3049 Find_Comparison_Types (Act1, Act2, Op_Id, N);
3051 elsif Op_Name = Name_Op_Eq
3052 or else Op_Name = Name_Op_Ne
3054 Find_Equality_Types (Act1, Act2, Op_Id, N);
3056 elsif Op_Name = Name_Op_Concat then
3057 Find_Concatenation_Types (Act1, Act2, Op_Id, N);
3059 -- Is this else null correct, or should it be an abort???
3065 -- Unary operator case
3068 if Op_Name = Name_Op_Subtract or else
3069 Op_Name = Name_Op_Add or else
3070 Op_Name = Name_Op_Abs
3072 Find_Unary_Types (Act1, Op_Id, N);
3075 Op_Name = Name_Op_Not
3077 Find_Negation_Types (Act1, Op_Id, N);
3079 -- Is this else null correct, or should it be an abort???
3085 end Analyze_Operator_Call;
3087 -------------------------------------------
3088 -- Analyze_Overloaded_Selected_Component --
3089 -------------------------------------------
3091 procedure Analyze_Overloaded_Selected_Component (N : Node_Id) is
3092 Nam : constant Node_Id := Prefix (N);
3093 Sel : constant Node_Id := Selector_Name (N);
3100 Set_Etype (Sel, Any_Type);
3102 Get_First_Interp (Nam, I, It);
3103 while Present (It.Typ) loop
3104 if Is_Access_Type (It.Typ) then
3105 T := Designated_Type (It.Typ);
3106 Error_Msg_NW (Warn_On_Dereference, "?implicit dereference", N);
3111 if Is_Record_Type (T) then
3113 -- If the prefix is a class-wide type, the visible components are
3114 -- those of the base type.
3116 if Is_Class_Wide_Type (T) then
3120 Comp := First_Entity (T);
3121 while Present (Comp) loop
3122 if Chars (Comp) = Chars (Sel)
3123 and then Is_Visible_Component (Comp)
3126 -- AI05-105: if the context is an object renaming with
3127 -- an anonymous access type, the expected type of the
3128 -- object must be anonymous. This is a name resolution rule.
3130 if Nkind (Parent (N)) /= N_Object_Renaming_Declaration
3131 or else No (Access_Definition (Parent (N)))
3132 or else Ekind (Etype (Comp)) = E_Anonymous_Access_Type
3134 Ekind (Etype (Comp)) = E_Anonymous_Access_Subprogram_Type
3136 Set_Entity (Sel, Comp);
3137 Set_Etype (Sel, Etype (Comp));
3138 Add_One_Interp (N, Etype (Comp), Etype (Comp));
3140 -- This also specifies a candidate to resolve the name.
3141 -- Further overloading will be resolved from context.
3142 -- The selector name itself does not carry overloading
3145 Set_Etype (Nam, It.Typ);
3148 -- Named access type in the context of a renaming
3149 -- declaration with an access definition. Remove
3150 -- inapplicable candidate.
3159 elsif Is_Concurrent_Type (T) then
3160 Comp := First_Entity (T);
3161 while Present (Comp)
3162 and then Comp /= First_Private_Entity (T)
3164 if Chars (Comp) = Chars (Sel) then
3165 if Is_Overloadable (Comp) then
3166 Add_One_Interp (Sel, Comp, Etype (Comp));
3168 Set_Entity_With_Style_Check (Sel, Comp);
3169 Generate_Reference (Comp, Sel);
3172 Set_Etype (Sel, Etype (Comp));
3173 Set_Etype (N, Etype (Comp));
3174 Set_Etype (Nam, It.Typ);
3176 -- For access type case, introduce explicit dereference for
3177 -- more uniform treatment of entry calls. Do this only once
3178 -- if several interpretations yield an access type.
3180 if Is_Access_Type (Etype (Nam))
3181 and then Nkind (Nam) /= N_Explicit_Dereference
3183 Insert_Explicit_Dereference (Nam);
3185 (Warn_On_Dereference, "?implicit dereference", N);
3192 Set_Is_Overloaded (N, Is_Overloaded (Sel));
3195 Get_Next_Interp (I, It);
3198 if Etype (N) = Any_Type
3199 and then not Try_Object_Operation (N)
3201 Error_Msg_NE ("undefined selector& for overloaded prefix", N, Sel);
3202 Set_Entity (Sel, Any_Id);
3203 Set_Etype (Sel, Any_Type);
3205 end Analyze_Overloaded_Selected_Component;
3207 ----------------------------------
3208 -- Analyze_Qualified_Expression --
3209 ----------------------------------
3211 procedure Analyze_Qualified_Expression (N : Node_Id) is
3212 Mark : constant Entity_Id := Subtype_Mark (N);
3213 Expr : constant Node_Id := Expression (N);
3219 Analyze_Expression (Expr);
3221 Set_Etype (N, Any_Type);
3226 if T = Any_Type then
3230 Check_Fully_Declared (T, N);
3232 -- If expected type is class-wide, check for exact match before
3233 -- expansion, because if the expression is a dispatching call it
3234 -- may be rewritten as explicit dereference with class-wide result.
3235 -- If expression is overloaded, retain only interpretations that
3236 -- will yield exact matches.
3238 if Is_Class_Wide_Type (T) then
3239 if not Is_Overloaded (Expr) then
3240 if Base_Type (Etype (Expr)) /= Base_Type (T) then
3241 if Nkind (Expr) = N_Aggregate then
3242 Error_Msg_N ("type of aggregate cannot be class-wide", Expr);
3244 Wrong_Type (Expr, T);
3249 Get_First_Interp (Expr, I, It);
3251 while Present (It.Nam) loop
3252 if Base_Type (It.Typ) /= Base_Type (T) then
3256 Get_Next_Interp (I, It);
3262 end Analyze_Qualified_Expression;
3264 -----------------------------------
3265 -- Analyze_Quantified_Expression --
3266 -----------------------------------
3268 procedure Analyze_Quantified_Expression (N : Node_Id) is
3269 Loc : constant Source_Ptr := Sloc (N);
3270 Ent : constant Entity_Id :=
3272 (E_Loop, Current_Scope, Sloc (N), 'L');
3277 Check_Formal_Restriction ("quantified expression is not allowed", N);
3279 Set_Etype (Ent, Standard_Void_Type);
3280 Set_Parent (Ent, N);
3282 if Present (Loop_Parameter_Specification (N)) then
3284 Make_Iteration_Scheme (Loc,
3285 Loop_Parameter_Specification =>
3286 Loop_Parameter_Specification (N));
3289 Make_Iteration_Scheme (Loc,
3290 Iterator_Specification =>
3291 Iterator_Specification (N));
3295 Set_Parent (Iterator, N);
3296 Analyze_Iteration_Scheme (Iterator);
3298 -- The loop specification may have been converted into an
3299 -- iterator specification during its analysis. Update the
3300 -- quantified node accordingly.
3302 if Present (Iterator_Specification (Iterator)) then
3303 Set_Iterator_Specification
3304 (N, Iterator_Specification (Iterator));
3305 Set_Loop_Parameter_Specification (N, Empty);
3308 Analyze (Condition (N));
3311 Set_Etype (N, Standard_Boolean);
3312 end Analyze_Quantified_Expression;
3318 procedure Analyze_Range (N : Node_Id) is
3319 L : constant Node_Id := Low_Bound (N);
3320 H : constant Node_Id := High_Bound (N);
3321 I1, I2 : Interp_Index;
3324 procedure Check_Common_Type (T1, T2 : Entity_Id);
3325 -- Verify the compatibility of two types, and choose the
3326 -- non universal one if the other is universal.
3328 procedure Check_High_Bound (T : Entity_Id);
3329 -- Test one interpretation of the low bound against all those
3330 -- of the high bound.
3332 procedure Check_Universal_Expression (N : Node_Id);
3333 -- In Ada83, reject bounds of a universal range that are not
3334 -- literals or entity names.
3336 -----------------------
3337 -- Check_Common_Type --
3338 -----------------------
3340 procedure Check_Common_Type (T1, T2 : Entity_Id) is
3342 if Covers (T1 => T1, T2 => T2)
3344 Covers (T1 => T2, T2 => T1)
3346 if T1 = Universal_Integer
3347 or else T1 = Universal_Real
3348 or else T1 = Any_Character
3350 Add_One_Interp (N, Base_Type (T2), Base_Type (T2));
3353 Add_One_Interp (N, T1, T1);
3356 Add_One_Interp (N, Base_Type (T1), Base_Type (T1));
3359 end Check_Common_Type;
3361 ----------------------
3362 -- Check_High_Bound --
3363 ----------------------
3365 procedure Check_High_Bound (T : Entity_Id) is
3367 if not Is_Overloaded (H) then
3368 Check_Common_Type (T, Etype (H));
3370 Get_First_Interp (H, I2, It2);
3371 while Present (It2.Typ) loop
3372 Check_Common_Type (T, It2.Typ);
3373 Get_Next_Interp (I2, It2);
3376 end Check_High_Bound;
3378 -----------------------------
3379 -- Is_Universal_Expression --
3380 -----------------------------
3382 procedure Check_Universal_Expression (N : Node_Id) is
3384 if Etype (N) = Universal_Integer
3385 and then Nkind (N) /= N_Integer_Literal
3386 and then not Is_Entity_Name (N)
3387 and then Nkind (N) /= N_Attribute_Reference
3389 Error_Msg_N ("illegal bound in discrete range", N);
3391 end Check_Universal_Expression;
3393 -- Start of processing for Analyze_Range
3396 Set_Etype (N, Any_Type);
3397 Analyze_Expression (L);
3398 Analyze_Expression (H);
3400 if Etype (L) = Any_Type or else Etype (H) = Any_Type then
3404 if not Is_Overloaded (L) then
3405 Check_High_Bound (Etype (L));
3407 Get_First_Interp (L, I1, It1);
3408 while Present (It1.Typ) loop
3409 Check_High_Bound (It1.Typ);
3410 Get_Next_Interp (I1, It1);
3414 -- If result is Any_Type, then we did not find a compatible pair
3416 if Etype (N) = Any_Type then
3417 Error_Msg_N ("incompatible types in range ", N);
3421 if Ada_Version = Ada_83
3423 (Nkind (Parent (N)) = N_Loop_Parameter_Specification
3424 or else Nkind (Parent (N)) = N_Constrained_Array_Definition)
3426 Check_Universal_Expression (L);
3427 Check_Universal_Expression (H);
3431 -----------------------
3432 -- Analyze_Reference --
3433 -----------------------
3435 procedure Analyze_Reference (N : Node_Id) is
3436 P : constant Node_Id := Prefix (N);
3439 Acc_Type : Entity_Id;
3444 -- An interesting error check, if we take the 'Reference of an object
3445 -- for which a pragma Atomic or Volatile has been given, and the type
3446 -- of the object is not Atomic or Volatile, then we are in trouble. The
3447 -- problem is that no trace of the atomic/volatile status will remain
3448 -- for the backend to respect when it deals with the resulting pointer,
3449 -- since the pointer type will not be marked atomic (it is a pointer to
3450 -- the base type of the object).
3452 -- It is not clear if that can ever occur, but in case it does, we will
3453 -- generate an error message. Not clear if this message can ever be
3454 -- generated, and pretty clear that it represents a bug if it is, still
3455 -- seems worth checking, except in CodePeer mode where we do not really
3456 -- care and don't want to bother the user.
3460 if Is_Entity_Name (P)
3461 and then Is_Object_Reference (P)
3462 and then not CodePeer_Mode
3467 if (Has_Atomic_Components (E)
3468 and then not Has_Atomic_Components (T))
3470 (Has_Volatile_Components (E)
3471 and then not Has_Volatile_Components (T))
3472 or else (Is_Atomic (E) and then not Is_Atomic (T))
3473 or else (Is_Volatile (E) and then not Is_Volatile (T))
3475 Error_Msg_N ("cannot take reference to Atomic/Volatile object", N);
3479 -- Carry on with normal processing
3481 Acc_Type := Create_Itype (E_Allocator_Type, N);
3482 Set_Etype (Acc_Type, Acc_Type);
3483 Set_Directly_Designated_Type (Acc_Type, Etype (P));
3484 Set_Etype (N, Acc_Type);
3485 end Analyze_Reference;
3487 --------------------------------
3488 -- Analyze_Selected_Component --
3489 --------------------------------
3491 -- Prefix is a record type or a task or protected type. In the latter case,
3492 -- the selector must denote a visible entry.
3494 procedure Analyze_Selected_Component (N : Node_Id) is
3495 Name : constant Node_Id := Prefix (N);
3496 Sel : constant Node_Id := Selector_Name (N);
3499 Has_Candidate : Boolean := False;
3502 Pent : Entity_Id := Empty;
3503 Prefix_Type : Entity_Id;
3505 Type_To_Use : Entity_Id;
3506 -- In most cases this is the Prefix_Type, but if the Prefix_Type is
3507 -- a class-wide type, we use its root type, whose components are
3508 -- present in the class-wide type.
3510 Is_Single_Concurrent_Object : Boolean;
3511 -- Set True if the prefix is a single task or a single protected object
3513 procedure Find_Component_In_Instance (Rec : Entity_Id);
3514 -- In an instance, a component of a private extension may not be visible
3515 -- while it was visible in the generic. Search candidate scope for a
3516 -- component with the proper identifier. This is only done if all other
3517 -- searches have failed. When the match is found (it always will be),
3518 -- the Etype of both N and Sel are set from this component, and the
3519 -- entity of Sel is set to reference this component.
3521 function Has_Mode_Conformant_Spec (Comp : Entity_Id) return Boolean;
3522 -- It is known that the parent of N denotes a subprogram call. Comp
3523 -- is an overloadable component of the concurrent type of the prefix.
3524 -- Determine whether all formals of the parent of N and Comp are mode
3525 -- conformant. If the parent node is not analyzed yet it may be an
3526 -- indexed component rather than a function call.
3528 --------------------------------
3529 -- Find_Component_In_Instance --
3530 --------------------------------
3532 procedure Find_Component_In_Instance (Rec : Entity_Id) is
3536 Comp := First_Component (Rec);
3537 while Present (Comp) loop
3538 if Chars (Comp) = Chars (Sel) then
3539 Set_Entity_With_Style_Check (Sel, Comp);
3540 Set_Etype (Sel, Etype (Comp));
3541 Set_Etype (N, Etype (Comp));
3545 Next_Component (Comp);
3548 -- This must succeed because code was legal in the generic
3550 raise Program_Error;
3551 end Find_Component_In_Instance;
3553 ------------------------------
3554 -- Has_Mode_Conformant_Spec --
3555 ------------------------------
3557 function Has_Mode_Conformant_Spec (Comp : Entity_Id) return Boolean is
3558 Comp_Param : Entity_Id;
3560 Param_Typ : Entity_Id;
3563 Comp_Param := First_Formal (Comp);
3565 if Nkind (Parent (N)) = N_Indexed_Component then
3566 Param := First (Expressions (Parent (N)));
3568 Param := First (Parameter_Associations (Parent (N)));
3571 while Present (Comp_Param)
3572 and then Present (Param)
3574 Param_Typ := Find_Parameter_Type (Param);
3576 if Present (Param_Typ)
3578 not Conforming_Types
3579 (Etype (Comp_Param), Param_Typ, Mode_Conformant)
3584 Next_Formal (Comp_Param);
3588 -- One of the specs has additional formals
3590 if Present (Comp_Param) or else Present (Param) then
3595 end Has_Mode_Conformant_Spec;
3597 -- Start of processing for Analyze_Selected_Component
3600 Set_Etype (N, Any_Type);
3602 if Is_Overloaded (Name) then
3603 Analyze_Overloaded_Selected_Component (N);
3606 elsif Etype (Name) = Any_Type then
3607 Set_Entity (Sel, Any_Id);
3608 Set_Etype (Sel, Any_Type);
3612 Prefix_Type := Etype (Name);
3615 if Is_Access_Type (Prefix_Type) then
3617 -- A RACW object can never be used as prefix of a selected component
3618 -- since that means it is dereferenced without being a controlling
3619 -- operand of a dispatching operation (RM E.2.2(16/1)). Before
3620 -- reporting an error, we must check whether this is actually a
3621 -- dispatching call in prefix form.
3623 if Is_Remote_Access_To_Class_Wide_Type (Prefix_Type)
3624 and then Comes_From_Source (N)
3626 if Try_Object_Operation (N) then
3630 ("invalid dereference of a remote access-to-class-wide value",
3634 -- Normal case of selected component applied to access type
3637 Error_Msg_NW (Warn_On_Dereference, "?implicit dereference", N);
3639 if Is_Entity_Name (Name) then
3640 Pent := Entity (Name);
3641 elsif Nkind (Name) = N_Selected_Component
3642 and then Is_Entity_Name (Selector_Name (Name))
3644 Pent := Entity (Selector_Name (Name));
3647 Prefix_Type := Process_Implicit_Dereference_Prefix (Pent, Name);
3650 -- If we have an explicit dereference of a remote access-to-class-wide
3651 -- value, then issue an error (see RM-E.2.2(16/1)). However we first
3652 -- have to check for the case of a prefix that is a controlling operand
3653 -- of a prefixed dispatching call, as the dereference is legal in that
3654 -- case. Normally this condition is checked in Validate_Remote_Access_
3655 -- To_Class_Wide_Type, but we have to defer the checking for selected
3656 -- component prefixes because of the prefixed dispatching call case.
3657 -- Note that implicit dereferences are checked for this just above.
3659 elsif Nkind (Name) = N_Explicit_Dereference
3660 and then Is_Remote_Access_To_Class_Wide_Type (Etype (Prefix (Name)))
3661 and then Comes_From_Source (N)
3663 if Try_Object_Operation (N) then
3667 ("invalid dereference of a remote access-to-class-wide value",
3672 -- (Ada 2005): if the prefix is the limited view of a type, and
3673 -- the context already includes the full view, use the full view
3674 -- in what follows, either to retrieve a component of to find
3675 -- a primitive operation. If the prefix is an explicit dereference,
3676 -- set the type of the prefix to reflect this transformation.
3677 -- If the non-limited view is itself an incomplete type, get the
3678 -- full view if available.
3680 if Is_Incomplete_Type (Prefix_Type)
3681 and then From_With_Type (Prefix_Type)
3682 and then Present (Non_Limited_View (Prefix_Type))
3684 Prefix_Type := Get_Full_View (Non_Limited_View (Prefix_Type));
3686 if Nkind (N) = N_Explicit_Dereference then
3687 Set_Etype (Prefix (N), Prefix_Type);
3690 elsif Ekind (Prefix_Type) = E_Class_Wide_Type
3691 and then From_With_Type (Prefix_Type)
3692 and then Present (Non_Limited_View (Etype (Prefix_Type)))
3695 Class_Wide_Type (Non_Limited_View (Etype (Prefix_Type)));
3697 if Nkind (N) = N_Explicit_Dereference then
3698 Set_Etype (Prefix (N), Prefix_Type);
3702 if Ekind (Prefix_Type) = E_Private_Subtype then
3703 Prefix_Type := Base_Type (Prefix_Type);
3706 Type_To_Use := Prefix_Type;
3708 -- For class-wide types, use the entity list of the root type. This
3709 -- indirection is specially important for private extensions because
3710 -- only the root type get switched (not the class-wide type).
3712 if Is_Class_Wide_Type (Prefix_Type) then
3713 Type_To_Use := Root_Type (Prefix_Type);
3716 -- If the prefix is a single concurrent object, use its name in error
3717 -- messages, rather than that of its anonymous type.
3719 Is_Single_Concurrent_Object :=
3720 Is_Concurrent_Type (Prefix_Type)
3721 and then Is_Internal_Name (Chars (Prefix_Type))
3722 and then not Is_Derived_Type (Prefix_Type)
3723 and then Is_Entity_Name (Name);
3725 Comp := First_Entity (Type_To_Use);
3727 -- If the selector has an original discriminant, the node appears in
3728 -- an instance. Replace the discriminant with the corresponding one
3729 -- in the current discriminated type. For nested generics, this must
3730 -- be done transitively, so note the new original discriminant.
3732 if Nkind (Sel) = N_Identifier
3733 and then Present (Original_Discriminant (Sel))
3735 Comp := Find_Corresponding_Discriminant (Sel, Prefix_Type);
3737 -- Mark entity before rewriting, for completeness and because
3738 -- subsequent semantic checks might examine the original node.
3740 Set_Entity (Sel, Comp);
3741 Rewrite (Selector_Name (N),
3742 New_Occurrence_Of (Comp, Sloc (N)));
3743 Set_Original_Discriminant (Selector_Name (N), Comp);
3744 Set_Etype (N, Etype (Comp));
3746 if Is_Access_Type (Etype (Name)) then
3747 Insert_Explicit_Dereference (Name);
3748 Error_Msg_NW (Warn_On_Dereference, "?implicit dereference", N);
3751 elsif Is_Record_Type (Prefix_Type) then
3753 -- Find component with given name
3755 while Present (Comp) loop
3756 if Chars (Comp) = Chars (Sel)
3757 and then Is_Visible_Component (Comp)
3759 Set_Entity_With_Style_Check (Sel, Comp);
3760 Set_Etype (Sel, Etype (Comp));
3762 if Ekind (Comp) = E_Discriminant then
3763 if Is_Unchecked_Union (Base_Type (Prefix_Type)) then
3765 ("cannot reference discriminant of Unchecked_Union",
3769 if Is_Generic_Type (Prefix_Type)
3771 Is_Generic_Type (Root_Type (Prefix_Type))
3773 Set_Original_Discriminant (Sel, Comp);
3777 -- Resolve the prefix early otherwise it is not possible to
3778 -- build the actual subtype of the component: it may need
3779 -- to duplicate this prefix and duplication is only allowed
3780 -- on fully resolved expressions.
3784 -- Ada 2005 (AI-50217): Check wrong use of incomplete types or
3785 -- subtypes in a package specification.
3788 -- limited with Pkg;
3790 -- type Acc_Inc is access Pkg.T;
3792 -- N : Natural := X.all.Comp; -- ERROR, limited view
3793 -- end Pkg; -- Comp is not visible
3795 if Nkind (Name) = N_Explicit_Dereference
3796 and then From_With_Type (Etype (Prefix (Name)))
3797 and then not Is_Potentially_Use_Visible (Etype (Name))
3798 and then Nkind (Parent (Cunit_Entity (Current_Sem_Unit))) =
3799 N_Package_Specification
3802 ("premature usage of incomplete}", Prefix (Name),
3803 Etype (Prefix (Name)));
3806 -- We never need an actual subtype for the case of a selection
3807 -- for a indexed component of a non-packed array, since in
3808 -- this case gigi generates all the checks and can find the
3809 -- necessary bounds information.
3811 -- We also do not need an actual subtype for the case of a
3812 -- first, last, length, or range attribute applied to a
3813 -- non-packed array, since gigi can again get the bounds in
3814 -- these cases (gigi cannot handle the packed case, since it
3815 -- has the bounds of the packed array type, not the original
3816 -- bounds of the type). However, if the prefix is itself a
3817 -- selected component, as in a.b.c (i), gigi may regard a.b.c
3818 -- as a dynamic-sized temporary, so we do generate an actual
3819 -- subtype for this case.
3821 Parent_N := Parent (N);
3823 if not Is_Packed (Etype (Comp))
3825 ((Nkind (Parent_N) = N_Indexed_Component
3826 and then Nkind (Name) /= N_Selected_Component)
3828 (Nkind (Parent_N) = N_Attribute_Reference
3829 and then (Attribute_Name (Parent_N) = Name_First
3831 Attribute_Name (Parent_N) = Name_Last
3833 Attribute_Name (Parent_N) = Name_Length
3835 Attribute_Name (Parent_N) = Name_Range)))
3837 Set_Etype (N, Etype (Comp));
3839 -- If full analysis is not enabled, we do not generate an
3840 -- actual subtype, because in the absence of expansion
3841 -- reference to a formal of a protected type, for example,
3842 -- will not be properly transformed, and will lead to
3843 -- out-of-scope references in gigi.
3845 -- In all other cases, we currently build an actual subtype.
3846 -- It seems likely that many of these cases can be avoided,
3847 -- but right now, the front end makes direct references to the
3848 -- bounds (e.g. in generating a length check), and if we do
3849 -- not make an actual subtype, we end up getting a direct
3850 -- reference to a discriminant, which will not do.
3852 elsif Full_Analysis then
3854 Build_Actual_Subtype_Of_Component (Etype (Comp), N);
3855 Insert_Action (N, Act_Decl);
3857 if No (Act_Decl) then
3858 Set_Etype (N, Etype (Comp));
3861 -- Component type depends on discriminants. Enter the
3862 -- main attributes of the subtype.
3865 Subt : constant Entity_Id :=
3866 Defining_Identifier (Act_Decl);
3869 Set_Etype (Subt, Base_Type (Etype (Comp)));
3870 Set_Ekind (Subt, Ekind (Etype (Comp)));
3871 Set_Etype (N, Subt);
3875 -- If Full_Analysis not enabled, just set the Etype
3878 Set_Etype (N, Etype (Comp));
3884 -- If the prefix is a private extension, check only the visible
3885 -- components of the partial view. This must include the tag,
3886 -- which can appear in expanded code in a tag check.
3888 if Ekind (Type_To_Use) = E_Record_Type_With_Private
3889 and then Chars (Selector_Name (N)) /= Name_uTag
3891 exit when Comp = Last_Entity (Type_To_Use);
3897 -- Ada 2005 (AI-252): The selected component can be interpreted as
3898 -- a prefixed view of a subprogram. Depending on the context, this is
3899 -- either a name that can appear in a renaming declaration, or part
3900 -- of an enclosing call given in prefix form.
3902 -- Ada 2005 (AI05-0030): In the case of dispatching requeue, the
3903 -- selected component should resolve to a name.
3905 if Ada_Version >= Ada_2005
3906 and then Is_Tagged_Type (Prefix_Type)
3907 and then not Is_Concurrent_Type (Prefix_Type)
3909 if Nkind (Parent (N)) = N_Generic_Association
3910 or else Nkind (Parent (N)) = N_Requeue_Statement
3911 or else Nkind (Parent (N)) = N_Subprogram_Renaming_Declaration
3913 if Find_Primitive_Operation (N) then
3917 elsif Try_Object_Operation (N) then
3921 -- If the transformation fails, it will be necessary to redo the
3922 -- analysis with all errors enabled, to indicate candidate
3923 -- interpretations and reasons for each failure ???
3927 elsif Is_Private_Type (Prefix_Type) then
3929 -- Allow access only to discriminants of the type. If the type has
3930 -- no full view, gigi uses the parent type for the components, so we
3931 -- do the same here.
3933 if No (Full_View (Prefix_Type)) then
3934 Type_To_Use := Root_Type (Base_Type (Prefix_Type));
3935 Comp := First_Entity (Type_To_Use);
3938 while Present (Comp) loop
3939 if Chars (Comp) = Chars (Sel) then
3940 if Ekind (Comp) = E_Discriminant then
3941 Set_Entity_With_Style_Check (Sel, Comp);
3942 Generate_Reference (Comp, Sel);
3944 Set_Etype (Sel, Etype (Comp));
3945 Set_Etype (N, Etype (Comp));
3947 if Is_Generic_Type (Prefix_Type)
3948 or else Is_Generic_Type (Root_Type (Prefix_Type))
3950 Set_Original_Discriminant (Sel, Comp);
3953 -- Before declaring an error, check whether this is tagged
3954 -- private type and a call to a primitive operation.
3956 elsif Ada_Version >= Ada_2005
3957 and then Is_Tagged_Type (Prefix_Type)
3958 and then Try_Object_Operation (N)
3963 Error_Msg_Node_2 := First_Subtype (Prefix_Type);
3964 Error_Msg_NE ("invisible selector& for }", N, Sel);
3965 Set_Entity (Sel, Any_Id);
3966 Set_Etype (N, Any_Type);
3975 elsif Is_Concurrent_Type (Prefix_Type) then
3977 -- Find visible operation with given name. For a protected type,
3978 -- the possible candidates are discriminants, entries or protected
3979 -- procedures. For a task type, the set can only include entries or
3980 -- discriminants if the task type is not an enclosing scope. If it
3981 -- is an enclosing scope (e.g. in an inner task) then all entities
3982 -- are visible, but the prefix must denote the enclosing scope, i.e.
3983 -- can only be a direct name or an expanded name.
3985 Set_Etype (Sel, Any_Type);
3986 In_Scope := In_Open_Scopes (Prefix_Type);
3988 while Present (Comp) loop
3989 if Chars (Comp) = Chars (Sel) then
3990 if Is_Overloadable (Comp) then
3991 Add_One_Interp (Sel, Comp, Etype (Comp));
3993 -- If the prefix is tagged, the correct interpretation may
3994 -- lie in the primitive or class-wide operations of the
3995 -- type. Perform a simple conformance check to determine
3996 -- whether Try_Object_Operation should be invoked even if
3997 -- a visible entity is found.
3999 if Is_Tagged_Type (Prefix_Type)
4001 Nkind_In (Parent (N), N_Procedure_Call_Statement,
4003 N_Indexed_Component)
4004 and then Has_Mode_Conformant_Spec (Comp)
4006 Has_Candidate := True;
4009 -- Note: a selected component may not denote a component of a
4010 -- protected type (4.1.3(7)).
4012 elsif Ekind_In (Comp, E_Discriminant, E_Entry_Family)
4014 and then not Is_Protected_Type (Prefix_Type)
4015 and then Is_Entity_Name (Name))
4017 Set_Entity_With_Style_Check (Sel, Comp);
4018 Generate_Reference (Comp, Sel);
4024 Set_Etype (Sel, Etype (Comp));
4025 Set_Etype (N, Etype (Comp));
4027 if Ekind (Comp) = E_Discriminant then
4028 Set_Original_Discriminant (Sel, Comp);
4031 -- For access type case, introduce explicit dereference for
4032 -- more uniform treatment of entry calls.
4034 if Is_Access_Type (Etype (Name)) then
4035 Insert_Explicit_Dereference (Name);
4037 (Warn_On_Dereference, "?implicit dereference", N);
4043 exit when not In_Scope
4045 Comp = First_Private_Entity (Base_Type (Prefix_Type));
4048 -- If there is no visible entity with the given name or none of the
4049 -- visible entities are plausible interpretations, check whether
4050 -- there is some other primitive operation with that name.
4052 if Ada_Version >= Ada_2005
4053 and then Is_Tagged_Type (Prefix_Type)
4055 if (Etype (N) = Any_Type
4056 or else not Has_Candidate)
4057 and then Try_Object_Operation (N)
4061 -- If the context is not syntactically a procedure call, it
4062 -- may be a call to a primitive function declared outside of
4063 -- the synchronized type.
4065 -- If the context is a procedure call, there might still be
4066 -- an overloading between an entry and a primitive procedure
4067 -- declared outside of the synchronized type, called in prefix
4068 -- notation. This is harder to disambiguate because in one case
4069 -- the controlling formal is implicit ???
4071 elsif Nkind (Parent (N)) /= N_Procedure_Call_Statement
4072 and then Nkind (Parent (N)) /= N_Indexed_Component
4073 and then Try_Object_Operation (N)
4079 if Etype (N) = Any_Type and then Is_Protected_Type (Prefix_Type) then
4080 -- Case of a prefix of a protected type: selector might denote
4081 -- an invisible private component.
4083 Comp := First_Private_Entity (Base_Type (Prefix_Type));
4084 while Present (Comp) and then Chars (Comp) /= Chars (Sel) loop
4088 if Present (Comp) then
4089 if Is_Single_Concurrent_Object then
4090 Error_Msg_Node_2 := Entity (Name);
4091 Error_Msg_NE ("invisible selector& for &", N, Sel);
4094 Error_Msg_Node_2 := First_Subtype (Prefix_Type);
4095 Error_Msg_NE ("invisible selector& for }", N, Sel);
4101 Set_Is_Overloaded (N, Is_Overloaded (Sel));
4106 Error_Msg_NE ("invalid prefix in selected component&", N, Sel);
4109 -- If N still has no type, the component is not defined in the prefix
4111 if Etype (N) = Any_Type then
4113 if Is_Single_Concurrent_Object then
4114 Error_Msg_Node_2 := Entity (Name);
4115 Error_Msg_NE ("no selector& for&", N, Sel);
4117 Check_Misspelled_Selector (Type_To_Use, Sel);
4119 elsif Is_Generic_Type (Prefix_Type)
4120 and then Ekind (Prefix_Type) = E_Record_Type_With_Private
4121 and then Prefix_Type /= Etype (Prefix_Type)
4122 and then Is_Record_Type (Etype (Prefix_Type))
4124 -- If this is a derived formal type, the parent may have
4125 -- different visibility at this point. Try for an inherited
4126 -- component before reporting an error.
4128 Set_Etype (Prefix (N), Etype (Prefix_Type));
4129 Analyze_Selected_Component (N);
4132 -- Similarly, if this is the actual for a formal derived type, the
4133 -- component inherited from the generic parent may not be visible
4134 -- in the actual, but the selected component is legal.
4136 elsif Ekind (Prefix_Type) = E_Record_Subtype_With_Private
4137 and then Is_Generic_Actual_Type (Prefix_Type)
4138 and then Present (Full_View (Prefix_Type))
4141 Find_Component_In_Instance
4142 (Generic_Parent_Type (Parent (Prefix_Type)));
4145 -- Finally, the formal and the actual may be private extensions,
4146 -- but the generic is declared in a child unit of the parent, and
4147 -- an additional step is needed to retrieve the proper scope.
4150 and then Present (Parent_Subtype (Etype (Base_Type (Prefix_Type))))
4152 Find_Component_In_Instance
4153 (Parent_Subtype (Etype (Base_Type (Prefix_Type))));
4156 -- Component not found, specialize error message when appropriate
4159 if Ekind (Prefix_Type) = E_Record_Subtype then
4161 -- Check whether this is a component of the base type which
4162 -- is absent from a statically constrained subtype. This will
4163 -- raise constraint error at run time, but is not a compile-
4164 -- time error. When the selector is illegal for base type as
4165 -- well fall through and generate a compilation error anyway.
4167 Comp := First_Component (Base_Type (Prefix_Type));
4168 while Present (Comp) loop
4169 if Chars (Comp) = Chars (Sel)
4170 and then Is_Visible_Component (Comp)
4172 Set_Entity_With_Style_Check (Sel, Comp);
4173 Generate_Reference (Comp, Sel);
4174 Set_Etype (Sel, Etype (Comp));
4175 Set_Etype (N, Etype (Comp));
4177 -- Emit appropriate message. Gigi will replace the
4178 -- node subsequently with the appropriate Raise.
4180 Apply_Compile_Time_Constraint_Error
4181 (N, "component not present in }?",
4182 CE_Discriminant_Check_Failed,
4183 Ent => Prefix_Type, Rep => False);
4184 Set_Raises_Constraint_Error (N);
4188 Next_Component (Comp);
4193 Error_Msg_Node_2 := First_Subtype (Prefix_Type);
4194 Error_Msg_NE ("no selector& for}", N, Sel);
4196 Check_Misspelled_Selector (Type_To_Use, Sel);
4199 Set_Entity (Sel, Any_Id);
4200 Set_Etype (Sel, Any_Type);
4202 end Analyze_Selected_Component;
4204 ---------------------------
4205 -- Analyze_Short_Circuit --
4206 ---------------------------
4208 procedure Analyze_Short_Circuit (N : Node_Id) is
4209 L : constant Node_Id := Left_Opnd (N);
4210 R : constant Node_Id := Right_Opnd (N);
4215 Analyze_Expression (L);
4216 Analyze_Expression (R);
4217 Set_Etype (N, Any_Type);
4219 if not Is_Overloaded (L) then
4220 if Root_Type (Etype (L)) = Standard_Boolean
4221 and then Has_Compatible_Type (R, Etype (L))
4223 Add_One_Interp (N, Etype (L), Etype (L));
4227 Get_First_Interp (L, Ind, It);
4228 while Present (It.Typ) loop
4229 if Root_Type (It.Typ) = Standard_Boolean
4230 and then Has_Compatible_Type (R, It.Typ)
4232 Add_One_Interp (N, It.Typ, It.Typ);
4235 Get_Next_Interp (Ind, It);
4239 -- Here we have failed to find an interpretation. Clearly we know that
4240 -- it is not the case that both operands can have an interpretation of
4241 -- Boolean, but this is by far the most likely intended interpretation.
4242 -- So we simply resolve both operands as Booleans, and at least one of
4243 -- these resolutions will generate an error message, and we do not need
4244 -- to give another error message on the short circuit operation itself.
4246 if Etype (N) = Any_Type then
4247 Resolve (L, Standard_Boolean);
4248 Resolve (R, Standard_Boolean);
4249 Set_Etype (N, Standard_Boolean);
4251 end Analyze_Short_Circuit;
4257 procedure Analyze_Slice (N : Node_Id) is
4258 P : constant Node_Id := Prefix (N);
4259 D : constant Node_Id := Discrete_Range (N);
4260 Array_Type : Entity_Id;
4262 procedure Analyze_Overloaded_Slice;
4263 -- If the prefix is overloaded, select those interpretations that
4264 -- yield a one-dimensional array type.
4266 ------------------------------
4267 -- Analyze_Overloaded_Slice --
4268 ------------------------------
4270 procedure Analyze_Overloaded_Slice is
4276 Set_Etype (N, Any_Type);
4278 Get_First_Interp (P, I, It);
4279 while Present (It.Nam) loop
4282 if Is_Access_Type (Typ) then
4283 Typ := Designated_Type (Typ);
4284 Error_Msg_NW (Warn_On_Dereference, "?implicit dereference", N);
4287 if Is_Array_Type (Typ)
4288 and then Number_Dimensions (Typ) = 1
4289 and then Has_Compatible_Type (D, Etype (First_Index (Typ)))
4291 Add_One_Interp (N, Typ, Typ);
4294 Get_Next_Interp (I, It);
4297 if Etype (N) = Any_Type then
4298 Error_Msg_N ("expect array type in prefix of slice", N);
4300 end Analyze_Overloaded_Slice;
4302 -- Start of processing for Analyze_Slice
4305 Check_Formal_Restriction ("slice is not allowed", N);
4310 if Is_Overloaded (P) then
4311 Analyze_Overloaded_Slice;
4314 Array_Type := Etype (P);
4315 Set_Etype (N, Any_Type);
4317 if Is_Access_Type (Array_Type) then
4318 Array_Type := Designated_Type (Array_Type);
4319 Error_Msg_NW (Warn_On_Dereference, "?implicit dereference", N);
4322 if not Is_Array_Type (Array_Type) then
4323 Wrong_Type (P, Any_Array);
4325 elsif Number_Dimensions (Array_Type) > 1 then
4327 ("type is not one-dimensional array in slice prefix", N);
4330 Has_Compatible_Type (D, Etype (First_Index (Array_Type)))
4332 Wrong_Type (D, Etype (First_Index (Array_Type)));
4335 Set_Etype (N, Array_Type);
4340 -----------------------------
4341 -- Analyze_Type_Conversion --
4342 -----------------------------
4344 procedure Analyze_Type_Conversion (N : Node_Id) is
4345 Expr : constant Node_Id := Expression (N);
4349 -- If Conversion_OK is set, then the Etype is already set, and the
4350 -- only processing required is to analyze the expression. This is
4351 -- used to construct certain "illegal" conversions which are not
4352 -- allowed by Ada semantics, but can be handled OK by Gigi, see
4353 -- Sinfo for further details.
4355 if Conversion_OK (N) then
4360 -- Otherwise full type analysis is required, as well as some semantic
4361 -- checks to make sure the argument of the conversion is appropriate.
4363 Find_Type (Subtype_Mark (N));
4364 T := Entity (Subtype_Mark (N));
4366 Check_Fully_Declared (T, N);
4367 Analyze_Expression (Expr);
4368 Validate_Remote_Type_Type_Conversion (N);
4370 -- Only remaining step is validity checks on the argument. These
4371 -- are skipped if the conversion does not come from the source.
4373 if not Comes_From_Source (N) then
4376 -- If there was an error in a generic unit, no need to replicate the
4377 -- error message. Conversely, constant-folding in the generic may
4378 -- transform the argument of a conversion into a string literal, which
4379 -- is legal. Therefore the following tests are not performed in an
4382 elsif In_Instance then
4385 elsif Nkind (Expr) = N_Null then
4386 Error_Msg_N ("argument of conversion cannot be null", N);
4387 Error_Msg_N ("\use qualified expression instead", N);
4388 Set_Etype (N, Any_Type);
4390 elsif Nkind (Expr) = N_Aggregate then
4391 Error_Msg_N ("argument of conversion cannot be aggregate", N);
4392 Error_Msg_N ("\use qualified expression instead", N);
4394 elsif Nkind (Expr) = N_Allocator then
4395 Error_Msg_N ("argument of conversion cannot be an allocator", N);
4396 Error_Msg_N ("\use qualified expression instead", N);
4398 elsif Nkind (Expr) = N_String_Literal then
4399 Error_Msg_N ("argument of conversion cannot be string literal", N);
4400 Error_Msg_N ("\use qualified expression instead", N);
4402 elsif Nkind (Expr) = N_Character_Literal then
4403 if Ada_Version = Ada_83 then
4406 Error_Msg_N ("argument of conversion cannot be character literal",
4408 Error_Msg_N ("\use qualified expression instead", N);
4411 elsif Nkind (Expr) = N_Attribute_Reference
4413 (Attribute_Name (Expr) = Name_Access or else
4414 Attribute_Name (Expr) = Name_Unchecked_Access or else
4415 Attribute_Name (Expr) = Name_Unrestricted_Access)
4417 Error_Msg_N ("argument of conversion cannot be access", N);
4418 Error_Msg_N ("\use qualified expression instead", N);
4420 end Analyze_Type_Conversion;
4422 ----------------------
4423 -- Analyze_Unary_Op --
4424 ----------------------
4426 procedure Analyze_Unary_Op (N : Node_Id) is
4427 R : constant Node_Id := Right_Opnd (N);
4428 Op_Id : Entity_Id := Entity (N);
4431 Set_Etype (N, Any_Type);
4432 Candidate_Type := Empty;
4434 Analyze_Expression (R);
4436 if Present (Op_Id) then
4437 if Ekind (Op_Id) = E_Operator then
4438 Find_Unary_Types (R, Op_Id, N);
4440 Add_One_Interp (N, Op_Id, Etype (Op_Id));
4444 Op_Id := Get_Name_Entity_Id (Chars (N));
4445 while Present (Op_Id) loop
4446 if Ekind (Op_Id) = E_Operator then
4447 if No (Next_Entity (First_Entity (Op_Id))) then
4448 Find_Unary_Types (R, Op_Id, N);
4451 elsif Is_Overloadable (Op_Id) then
4452 Analyze_User_Defined_Unary_Op (N, Op_Id);
4455 Op_Id := Homonym (Op_Id);
4460 end Analyze_Unary_Op;
4462 ----------------------------------
4463 -- Analyze_Unchecked_Expression --
4464 ----------------------------------
4466 procedure Analyze_Unchecked_Expression (N : Node_Id) is
4468 Analyze (Expression (N), Suppress => All_Checks);
4469 Set_Etype (N, Etype (Expression (N)));
4470 Save_Interps (Expression (N), N);
4471 end Analyze_Unchecked_Expression;
4473 ---------------------------------------
4474 -- Analyze_Unchecked_Type_Conversion --
4475 ---------------------------------------
4477 procedure Analyze_Unchecked_Type_Conversion (N : Node_Id) is
4479 Find_Type (Subtype_Mark (N));
4480 Analyze_Expression (Expression (N));
4481 Set_Etype (N, Entity (Subtype_Mark (N)));
4482 end Analyze_Unchecked_Type_Conversion;
4484 ------------------------------------
4485 -- Analyze_User_Defined_Binary_Op --
4486 ------------------------------------
4488 procedure Analyze_User_Defined_Binary_Op
4493 -- Only do analysis if the operator Comes_From_Source, since otherwise
4494 -- the operator was generated by the expander, and all such operators
4495 -- always refer to the operators in package Standard.
4497 if Comes_From_Source (N) then
4499 F1 : constant Entity_Id := First_Formal (Op_Id);
4500 F2 : constant Entity_Id := Next_Formal (F1);
4503 -- Verify that Op_Id is a visible binary function. Note that since
4504 -- we know Op_Id is overloaded, potentially use visible means use
4505 -- visible for sure (RM 9.4(11)).
4507 if Ekind (Op_Id) = E_Function
4508 and then Present (F2)
4509 and then (Is_Immediately_Visible (Op_Id)
4510 or else Is_Potentially_Use_Visible (Op_Id))
4511 and then Has_Compatible_Type (Left_Opnd (N), Etype (F1))
4512 and then Has_Compatible_Type (Right_Opnd (N), Etype (F2))
4514 Add_One_Interp (N, Op_Id, Etype (Op_Id));
4516 -- If the left operand is overloaded, indicate that the
4517 -- current type is a viable candidate. This is redundant
4518 -- in most cases, but for equality and comparison operators
4519 -- where the context does not impose a type on the operands,
4520 -- setting the proper type is necessary to avoid subsequent
4521 -- ambiguities during resolution, when both user-defined and
4522 -- predefined operators may be candidates.
4524 if Is_Overloaded (Left_Opnd (N)) then
4525 Set_Etype (Left_Opnd (N), Etype (F1));
4528 if Debug_Flag_E then
4529 Write_Str ("user defined operator ");
4530 Write_Name (Chars (Op_Id));
4531 Write_Str (" on node ");
4532 Write_Int (Int (N));
4538 end Analyze_User_Defined_Binary_Op;
4540 -----------------------------------
4541 -- Analyze_User_Defined_Unary_Op --
4542 -----------------------------------
4544 procedure Analyze_User_Defined_Unary_Op
4549 -- Only do analysis if the operator Comes_From_Source, since otherwise
4550 -- the operator was generated by the expander, and all such operators
4551 -- always refer to the operators in package Standard.
4553 if Comes_From_Source (N) then
4555 F : constant Entity_Id := First_Formal (Op_Id);
4558 -- Verify that Op_Id is a visible unary function. Note that since
4559 -- we know Op_Id is overloaded, potentially use visible means use
4560 -- visible for sure (RM 9.4(11)).
4562 if Ekind (Op_Id) = E_Function
4563 and then No (Next_Formal (F))
4564 and then (Is_Immediately_Visible (Op_Id)
4565 or else Is_Potentially_Use_Visible (Op_Id))
4566 and then Has_Compatible_Type (Right_Opnd (N), Etype (F))
4568 Add_One_Interp (N, Op_Id, Etype (Op_Id));
4572 end Analyze_User_Defined_Unary_Op;
4574 ---------------------------
4575 -- Check_Arithmetic_Pair --
4576 ---------------------------
4578 procedure Check_Arithmetic_Pair
4579 (T1, T2 : Entity_Id;
4583 Op_Name : constant Name_Id := Chars (Op_Id);
4585 function Has_Fixed_Op (Typ : Entity_Id; Op : Entity_Id) return Boolean;
4586 -- Check whether the fixed-point type Typ has a user-defined operator
4587 -- (multiplication or division) that should hide the corresponding
4588 -- predefined operator. Used to implement Ada 2005 AI-264, to make
4589 -- such operators more visible and therefore useful.
4591 -- If the name of the operation is an expanded name with prefix
4592 -- Standard, the predefined universal fixed operator is available,
4593 -- as specified by AI-420 (RM 4.5.5 (19.1/2)).
4595 function Specific_Type (T1, T2 : Entity_Id) return Entity_Id;
4596 -- Get specific type (i.e. non-universal type if there is one)
4602 function Has_Fixed_Op (Typ : Entity_Id; Op : Entity_Id) return Boolean is
4603 Bas : constant Entity_Id := Base_Type (Typ);
4609 -- If the universal_fixed operation is given explicitly the rule
4610 -- concerning primitive operations of the type do not apply.
4612 if Nkind (N) = N_Function_Call
4613 and then Nkind (Name (N)) = N_Expanded_Name
4614 and then Entity (Prefix (Name (N))) = Standard_Standard
4619 -- The operation is treated as primitive if it is declared in the
4620 -- same scope as the type, and therefore on the same entity chain.
4622 Ent := Next_Entity (Typ);
4623 while Present (Ent) loop
4624 if Chars (Ent) = Chars (Op) then
4625 F1 := First_Formal (Ent);
4626 F2 := Next_Formal (F1);
4628 -- The operation counts as primitive if either operand or
4629 -- result are of the given base type, and both operands are
4630 -- fixed point types.
4632 if (Base_Type (Etype (F1)) = Bas
4633 and then Is_Fixed_Point_Type (Etype (F2)))
4636 (Base_Type (Etype (F2)) = Bas
4637 and then Is_Fixed_Point_Type (Etype (F1)))
4640 (Base_Type (Etype (Ent)) = Bas
4641 and then Is_Fixed_Point_Type (Etype (F1))
4642 and then Is_Fixed_Point_Type (Etype (F2)))
4658 function Specific_Type (T1, T2 : Entity_Id) return Entity_Id is
4660 if T1 = Universal_Integer or else T1 = Universal_Real then
4661 return Base_Type (T2);
4663 return Base_Type (T1);
4667 -- Start of processing for Check_Arithmetic_Pair
4670 if Op_Name = Name_Op_Add or else Op_Name = Name_Op_Subtract then
4672 if Is_Numeric_Type (T1)
4673 and then Is_Numeric_Type (T2)
4674 and then (Covers (T1 => T1, T2 => T2)
4676 Covers (T1 => T2, T2 => T1))
4678 Add_One_Interp (N, Op_Id, Specific_Type (T1, T2));
4681 elsif Op_Name = Name_Op_Multiply or else Op_Name = Name_Op_Divide then
4683 if Is_Fixed_Point_Type (T1)
4684 and then (Is_Fixed_Point_Type (T2)
4685 or else T2 = Universal_Real)
4687 -- If Treat_Fixed_As_Integer is set then the Etype is already set
4688 -- and no further processing is required (this is the case of an
4689 -- operator constructed by Exp_Fixd for a fixed point operation)
4690 -- Otherwise add one interpretation with universal fixed result
4691 -- If the operator is given in functional notation, it comes
4692 -- from source and Fixed_As_Integer cannot apply.
4694 if (Nkind (N) not in N_Op
4695 or else not Treat_Fixed_As_Integer (N))
4697 (not Has_Fixed_Op (T1, Op_Id)
4698 or else Nkind (Parent (N)) = N_Type_Conversion)
4700 Add_One_Interp (N, Op_Id, Universal_Fixed);
4703 elsif Is_Fixed_Point_Type (T2)
4704 and then (Nkind (N) not in N_Op
4705 or else not Treat_Fixed_As_Integer (N))
4706 and then T1 = Universal_Real
4708 (not Has_Fixed_Op (T1, Op_Id)
4709 or else Nkind (Parent (N)) = N_Type_Conversion)
4711 Add_One_Interp (N, Op_Id, Universal_Fixed);
4713 elsif Is_Numeric_Type (T1)
4714 and then Is_Numeric_Type (T2)
4715 and then (Covers (T1 => T1, T2 => T2)
4717 Covers (T1 => T2, T2 => T1))
4719 Add_One_Interp (N, Op_Id, Specific_Type (T1, T2));
4721 elsif Is_Fixed_Point_Type (T1)
4722 and then (Base_Type (T2) = Base_Type (Standard_Integer)
4723 or else T2 = Universal_Integer)
4725 Add_One_Interp (N, Op_Id, T1);
4727 elsif T2 = Universal_Real
4728 and then Base_Type (T1) = Base_Type (Standard_Integer)
4729 and then Op_Name = Name_Op_Multiply
4731 Add_One_Interp (N, Op_Id, Any_Fixed);
4733 elsif T1 = Universal_Real
4734 and then Base_Type (T2) = Base_Type (Standard_Integer)
4736 Add_One_Interp (N, Op_Id, Any_Fixed);
4738 elsif Is_Fixed_Point_Type (T2)
4739 and then (Base_Type (T1) = Base_Type (Standard_Integer)
4740 or else T1 = Universal_Integer)
4741 and then Op_Name = Name_Op_Multiply
4743 Add_One_Interp (N, Op_Id, T2);
4745 elsif T1 = Universal_Real and then T2 = Universal_Integer then
4746 Add_One_Interp (N, Op_Id, T1);
4748 elsif T2 = Universal_Real
4749 and then T1 = Universal_Integer
4750 and then Op_Name = Name_Op_Multiply
4752 Add_One_Interp (N, Op_Id, T2);
4755 elsif Op_Name = Name_Op_Mod or else Op_Name = Name_Op_Rem then
4757 -- Note: The fixed-point operands case with Treat_Fixed_As_Integer
4758 -- set does not require any special processing, since the Etype is
4759 -- already set (case of operation constructed by Exp_Fixed).
4761 if Is_Integer_Type (T1)
4762 and then (Covers (T1 => T1, T2 => T2)
4764 Covers (T1 => T2, T2 => T1))
4766 Add_One_Interp (N, Op_Id, Specific_Type (T1, T2));
4769 elsif Op_Name = Name_Op_Expon then
4770 if Is_Numeric_Type (T1)
4771 and then not Is_Fixed_Point_Type (T1)
4772 and then (Base_Type (T2) = Base_Type (Standard_Integer)
4773 or else T2 = Universal_Integer)
4775 Add_One_Interp (N, Op_Id, Base_Type (T1));
4778 else pragma Assert (Nkind (N) in N_Op_Shift);
4780 -- If not one of the predefined operators, the node may be one
4781 -- of the intrinsic functions. Its kind is always specific, and
4782 -- we can use it directly, rather than the name of the operation.
4784 if Is_Integer_Type (T1)
4785 and then (Base_Type (T2) = Base_Type (Standard_Integer)
4786 or else T2 = Universal_Integer)
4788 Add_One_Interp (N, Op_Id, Base_Type (T1));
4791 end Check_Arithmetic_Pair;
4793 -------------------------------
4794 -- Check_Misspelled_Selector --
4795 -------------------------------
4797 procedure Check_Misspelled_Selector
4798 (Prefix : Entity_Id;
4801 Max_Suggestions : constant := 2;
4802 Nr_Of_Suggestions : Natural := 0;
4804 Suggestion_1 : Entity_Id := Empty;
4805 Suggestion_2 : Entity_Id := Empty;
4810 -- All the components of the prefix of selector Sel are matched
4811 -- against Sel and a count is maintained of possible misspellings.
4812 -- When at the end of the analysis there are one or two (not more!)
4813 -- possible misspellings, these misspellings will be suggested as
4814 -- possible correction.
4816 if not (Is_Private_Type (Prefix) or else Is_Record_Type (Prefix)) then
4818 -- Concurrent types should be handled as well ???
4823 Comp := First_Entity (Prefix);
4824 while Nr_Of_Suggestions <= Max_Suggestions and then Present (Comp) loop
4825 if Is_Visible_Component (Comp) then
4826 if Is_Bad_Spelling_Of (Chars (Comp), Chars (Sel)) then
4827 Nr_Of_Suggestions := Nr_Of_Suggestions + 1;
4829 case Nr_Of_Suggestions is
4830 when 1 => Suggestion_1 := Comp;
4831 when 2 => Suggestion_2 := Comp;
4832 when others => exit;
4837 Comp := Next_Entity (Comp);
4840 -- Report at most two suggestions
4842 if Nr_Of_Suggestions = 1 then
4843 Error_Msg_NE -- CODEFIX
4844 ("\possible misspelling of&", Sel, Suggestion_1);
4846 elsif Nr_Of_Suggestions = 2 then
4847 Error_Msg_Node_2 := Suggestion_2;
4848 Error_Msg_NE -- CODEFIX
4849 ("\possible misspelling of& or&", Sel, Suggestion_1);
4851 end Check_Misspelled_Selector;
4853 ----------------------
4854 -- Defined_In_Scope --
4855 ----------------------
4857 function Defined_In_Scope (T : Entity_Id; S : Entity_Id) return Boolean
4859 S1 : constant Entity_Id := Scope (Base_Type (T));
4862 or else (S1 = System_Aux_Id and then S = Scope (S1));
4863 end Defined_In_Scope;
4869 procedure Diagnose_Call (N : Node_Id; Nam : Node_Id) is
4875 Void_Interp_Seen : Boolean := False;
4878 pragma Warnings (Off, Boolean);
4881 if Ada_Version >= Ada_2005 then
4882 Actual := First_Actual (N);
4883 while Present (Actual) loop
4885 -- Ada 2005 (AI-50217): Post an error in case of premature
4886 -- usage of an entity from the limited view.
4888 if not Analyzed (Etype (Actual))
4889 and then From_With_Type (Etype (Actual))
4891 Error_Msg_Qual_Level := 1;
4893 ("missing with_clause for scope of imported type&",
4894 Actual, Etype (Actual));
4895 Error_Msg_Qual_Level := 0;
4898 Next_Actual (Actual);
4902 -- Analyze each candidate call again, with full error reporting
4906 ("no candidate interpretations match the actuals:!", Nam);
4907 Err_Mode := All_Errors_Mode;
4908 All_Errors_Mode := True;
4910 -- If this is a call to an operation of a concurrent type,
4911 -- the failed interpretations have been removed from the
4912 -- name. Recover them to provide full diagnostics.
4914 if Nkind (Parent (Nam)) = N_Selected_Component then
4915 Set_Entity (Nam, Empty);
4916 New_Nam := New_Copy_Tree (Parent (Nam));
4917 Set_Is_Overloaded (New_Nam, False);
4918 Set_Is_Overloaded (Selector_Name (New_Nam), False);
4919 Set_Parent (New_Nam, Parent (Parent (Nam)));
4920 Analyze_Selected_Component (New_Nam);
4921 Get_First_Interp (Selector_Name (New_Nam), X, It);
4923 Get_First_Interp (Nam, X, It);
4926 while Present (It.Nam) loop
4927 if Etype (It.Nam) = Standard_Void_Type then
4928 Void_Interp_Seen := True;
4931 Analyze_One_Call (N, It.Nam, True, Success);
4932 Get_Next_Interp (X, It);
4935 if Nkind (N) = N_Function_Call then
4936 Get_First_Interp (Nam, X, It);
4937 while Present (It.Nam) loop
4938 if Ekind_In (It.Nam, E_Function, E_Operator) then
4941 Get_Next_Interp (X, It);
4945 -- If all interpretations are procedures, this deserves a
4946 -- more precise message. Ditto if this appears as the prefix
4947 -- of a selected component, which may be a lexical error.
4950 ("\context requires function call, found procedure name", Nam);
4952 if Nkind (Parent (N)) = N_Selected_Component
4953 and then N = Prefix (Parent (N))
4955 Error_Msg_N -- CODEFIX
4956 ("\period should probably be semicolon", Parent (N));
4959 elsif Nkind (N) = N_Procedure_Call_Statement
4960 and then not Void_Interp_Seen
4963 "\function name found in procedure call", Nam);
4966 All_Errors_Mode := Err_Mode;
4969 ---------------------------
4970 -- Find_Arithmetic_Types --
4971 ---------------------------
4973 procedure Find_Arithmetic_Types
4978 Index1 : Interp_Index;
4979 Index2 : Interp_Index;
4983 procedure Check_Right_Argument (T : Entity_Id);
4984 -- Check right operand of operator
4986 --------------------------
4987 -- Check_Right_Argument --
4988 --------------------------
4990 procedure Check_Right_Argument (T : Entity_Id) is
4992 if not Is_Overloaded (R) then
4993 Check_Arithmetic_Pair (T, Etype (R), Op_Id, N);
4995 Get_First_Interp (R, Index2, It2);
4996 while Present (It2.Typ) loop
4997 Check_Arithmetic_Pair (T, It2.Typ, Op_Id, N);
4998 Get_Next_Interp (Index2, It2);
5001 end Check_Right_Argument;
5003 -- Start of processing for Find_Arithmetic_Types
5006 if not Is_Overloaded (L) then
5007 Check_Right_Argument (Etype (L));
5010 Get_First_Interp (L, Index1, It1);
5011 while Present (It1.Typ) loop
5012 Check_Right_Argument (It1.Typ);
5013 Get_Next_Interp (Index1, It1);
5017 end Find_Arithmetic_Types;
5019 ------------------------
5020 -- Find_Boolean_Types --
5021 ------------------------
5023 procedure Find_Boolean_Types
5028 Index : Interp_Index;
5031 procedure Check_Numeric_Argument (T : Entity_Id);
5032 -- Special case for logical operations one of whose operands is an
5033 -- integer literal. If both are literal the result is any modular type.
5035 ----------------------------
5036 -- Check_Numeric_Argument --
5037 ----------------------------
5039 procedure Check_Numeric_Argument (T : Entity_Id) is
5041 if T = Universal_Integer then
5042 Add_One_Interp (N, Op_Id, Any_Modular);
5044 elsif Is_Modular_Integer_Type (T) then
5045 Add_One_Interp (N, Op_Id, T);
5047 end Check_Numeric_Argument;
5049 -- Start of processing for Find_Boolean_Types
5052 if not Is_Overloaded (L) then
5053 if Etype (L) = Universal_Integer
5054 or else Etype (L) = Any_Modular
5056 if not Is_Overloaded (R) then
5057 Check_Numeric_Argument (Etype (R));
5060 Get_First_Interp (R, Index, It);
5061 while Present (It.Typ) loop
5062 Check_Numeric_Argument (It.Typ);
5063 Get_Next_Interp (Index, It);
5067 -- If operands are aggregates, we must assume that they may be
5068 -- boolean arrays, and leave disambiguation for the second pass.
5069 -- If only one is an aggregate, verify that the other one has an
5070 -- interpretation as a boolean array
5072 elsif Nkind (L) = N_Aggregate then
5073 if Nkind (R) = N_Aggregate then
5074 Add_One_Interp (N, Op_Id, Etype (L));
5076 elsif not Is_Overloaded (R) then
5077 if Valid_Boolean_Arg (Etype (R)) then
5078 Add_One_Interp (N, Op_Id, Etype (R));
5082 Get_First_Interp (R, Index, It);
5083 while Present (It.Typ) loop
5084 if Valid_Boolean_Arg (It.Typ) then
5085 Add_One_Interp (N, Op_Id, It.Typ);
5088 Get_Next_Interp (Index, It);
5092 elsif Valid_Boolean_Arg (Etype (L))
5093 and then Has_Compatible_Type (R, Etype (L))
5095 Add_One_Interp (N, Op_Id, Etype (L));
5099 Get_First_Interp (L, Index, It);
5100 while Present (It.Typ) loop
5101 if Valid_Boolean_Arg (It.Typ)
5102 and then Has_Compatible_Type (R, It.Typ)
5104 Add_One_Interp (N, Op_Id, It.Typ);
5107 Get_Next_Interp (Index, It);
5110 end Find_Boolean_Types;
5112 ---------------------------
5113 -- Find_Comparison_Types --
5114 ---------------------------
5116 procedure Find_Comparison_Types
5121 Index : Interp_Index;
5123 Found : Boolean := False;
5126 Scop : Entity_Id := Empty;
5128 procedure Try_One_Interp (T1 : Entity_Id);
5129 -- Routine to try one proposed interpretation. Note that the context
5130 -- of the operator plays no role in resolving the arguments, so that
5131 -- if there is more than one interpretation of the operands that is
5132 -- compatible with comparison, the operation is ambiguous.
5134 --------------------
5135 -- Try_One_Interp --
5136 --------------------
5138 procedure Try_One_Interp (T1 : Entity_Id) is
5141 -- If the operator is an expanded name, then the type of the operand
5142 -- must be defined in the corresponding scope. If the type is
5143 -- universal, the context will impose the correct type.
5146 and then not Defined_In_Scope (T1, Scop)
5147 and then T1 /= Universal_Integer
5148 and then T1 /= Universal_Real
5149 and then T1 /= Any_String
5150 and then T1 /= Any_Composite
5155 if Valid_Comparison_Arg (T1)
5156 and then Has_Compatible_Type (R, T1)
5159 and then Base_Type (T1) /= Base_Type (T_F)
5161 It := Disambiguate (L, I_F, Index, Any_Type);
5163 if It = No_Interp then
5164 Ambiguous_Operands (N);
5165 Set_Etype (L, Any_Type);
5179 Find_Non_Universal_Interpretations (N, R, Op_Id, T1);
5184 -- Start of processing for Find_Comparison_Types
5187 -- If left operand is aggregate, the right operand has to
5188 -- provide a usable type for it.
5190 if Nkind (L) = N_Aggregate
5191 and then Nkind (R) /= N_Aggregate
5193 Find_Comparison_Types (L => R, R => L, Op_Id => Op_Id, N => N);
5197 if Nkind (N) = N_Function_Call
5198 and then Nkind (Name (N)) = N_Expanded_Name
5200 Scop := Entity (Prefix (Name (N)));
5202 -- The prefix may be a package renaming, and the subsequent test
5203 -- requires the original package.
5205 if Ekind (Scop) = E_Package
5206 and then Present (Renamed_Entity (Scop))
5208 Scop := Renamed_Entity (Scop);
5209 Set_Entity (Prefix (Name (N)), Scop);
5213 if not Is_Overloaded (L) then
5214 Try_One_Interp (Etype (L));
5217 Get_First_Interp (L, Index, It);
5218 while Present (It.Typ) loop
5219 Try_One_Interp (It.Typ);
5220 Get_Next_Interp (Index, It);
5223 end Find_Comparison_Types;
5225 ----------------------------------------
5226 -- Find_Non_Universal_Interpretations --
5227 ----------------------------------------
5229 procedure Find_Non_Universal_Interpretations
5235 Index : Interp_Index;
5239 if T1 = Universal_Integer
5240 or else T1 = Universal_Real
5242 if not Is_Overloaded (R) then
5244 (N, Op_Id, Standard_Boolean, Base_Type (Etype (R)));
5246 Get_First_Interp (R, Index, It);
5247 while Present (It.Typ) loop
5248 if Covers (It.Typ, T1) then
5250 (N, Op_Id, Standard_Boolean, Base_Type (It.Typ));
5253 Get_Next_Interp (Index, It);
5257 Add_One_Interp (N, Op_Id, Standard_Boolean, Base_Type (T1));
5259 end Find_Non_Universal_Interpretations;
5261 ------------------------------
5262 -- Find_Concatenation_Types --
5263 ------------------------------
5265 procedure Find_Concatenation_Types
5270 Op_Type : constant Entity_Id := Etype (Op_Id);
5273 if Is_Array_Type (Op_Type)
5274 and then not Is_Limited_Type (Op_Type)
5276 and then (Has_Compatible_Type (L, Op_Type)
5278 Has_Compatible_Type (L, Component_Type (Op_Type)))
5280 and then (Has_Compatible_Type (R, Op_Type)
5282 Has_Compatible_Type (R, Component_Type (Op_Type)))
5284 Add_One_Interp (N, Op_Id, Op_Type);
5286 end Find_Concatenation_Types;
5288 -------------------------
5289 -- Find_Equality_Types --
5290 -------------------------
5292 procedure Find_Equality_Types
5297 Index : Interp_Index;
5299 Found : Boolean := False;
5302 Scop : Entity_Id := Empty;
5304 procedure Try_One_Interp (T1 : Entity_Id);
5305 -- The context of the equality operator plays no role in resolving the
5306 -- arguments, so that if there is more than one interpretation of the
5307 -- operands that is compatible with equality, the construct is ambiguous
5308 -- and an error can be emitted now, after trying to disambiguate, i.e.
5309 -- applying preference rules.
5311 --------------------
5312 -- Try_One_Interp --
5313 --------------------
5315 procedure Try_One_Interp (T1 : Entity_Id) is
5316 Bas : constant Entity_Id := Base_Type (T1);
5319 -- If the operator is an expanded name, then the type of the operand
5320 -- must be defined in the corresponding scope. If the type is
5321 -- universal, the context will impose the correct type. An anonymous
5322 -- type for a 'Access reference is also universal in this sense, as
5323 -- the actual type is obtained from context.
5324 -- In Ada 2005, the equality operator for anonymous access types
5325 -- is declared in Standard, and preference rules apply to it.
5327 if Present (Scop) then
5328 if Defined_In_Scope (T1, Scop)
5329 or else T1 = Universal_Integer
5330 or else T1 = Universal_Real
5331 or else T1 = Any_Access
5332 or else T1 = Any_String
5333 or else T1 = Any_Composite
5334 or else (Ekind (T1) = E_Access_Subprogram_Type
5335 and then not Comes_From_Source (T1))
5339 elsif Ekind (T1) = E_Anonymous_Access_Type
5340 and then Scop = Standard_Standard
5345 -- The scope does not contain an operator for the type
5350 -- If we have infix notation, the operator must be usable.
5351 -- Within an instance, if the type is already established we
5352 -- know it is correct.
5353 -- In Ada 2005, the equality on anonymous access types is declared
5354 -- in Standard, and is always visible.
5356 elsif In_Open_Scopes (Scope (Bas))
5357 or else Is_Potentially_Use_Visible (Bas)
5358 or else In_Use (Bas)
5359 or else (In_Use (Scope (Bas))
5360 and then not Is_Hidden (Bas))
5361 or else (In_Instance
5362 and then First_Subtype (T1) = First_Subtype (Etype (R)))
5363 or else Ekind (T1) = E_Anonymous_Access_Type
5368 -- Save candidate type for subsequent error message, if any
5370 if not Is_Limited_Type (T1) then
5371 Candidate_Type := T1;
5377 -- Ada 2005 (AI-230): Keep restriction imposed by Ada 83 and 95:
5378 -- Do not allow anonymous access types in equality operators.
5380 if Ada_Version < Ada_2005
5381 and then Ekind (T1) = E_Anonymous_Access_Type
5386 if T1 /= Standard_Void_Type
5387 and then not Is_Limited_Type (T1)
5388 and then not Is_Limited_Composite (T1)
5389 and then Has_Compatible_Type (R, T1)
5392 and then Base_Type (T1) /= Base_Type (T_F)
5394 It := Disambiguate (L, I_F, Index, Any_Type);
5396 if It = No_Interp then
5397 Ambiguous_Operands (N);
5398 Set_Etype (L, Any_Type);
5411 if not Analyzed (L) then
5415 Find_Non_Universal_Interpretations (N, R, Op_Id, T1);
5417 -- Case of operator was not visible, Etype still set to Any_Type
5419 if Etype (N) = Any_Type then
5423 elsif Scop = Standard_Standard
5424 and then Ekind (T1) = E_Anonymous_Access_Type
5430 -- Start of processing for Find_Equality_Types
5433 -- If left operand is aggregate, the right operand has to
5434 -- provide a usable type for it.
5436 if Nkind (L) = N_Aggregate
5437 and then Nkind (R) /= N_Aggregate
5439 Find_Equality_Types (L => R, R => L, Op_Id => Op_Id, N => N);
5443 if Nkind (N) = N_Function_Call
5444 and then Nkind (Name (N)) = N_Expanded_Name
5446 Scop := Entity (Prefix (Name (N)));
5448 -- The prefix may be a package renaming, and the subsequent test
5449 -- requires the original package.
5451 if Ekind (Scop) = E_Package
5452 and then Present (Renamed_Entity (Scop))
5454 Scop := Renamed_Entity (Scop);
5455 Set_Entity (Prefix (Name (N)), Scop);
5459 if not Is_Overloaded (L) then
5460 Try_One_Interp (Etype (L));
5463 Get_First_Interp (L, Index, It);
5464 while Present (It.Typ) loop
5465 Try_One_Interp (It.Typ);
5466 Get_Next_Interp (Index, It);
5469 end Find_Equality_Types;
5471 -------------------------
5472 -- Find_Negation_Types --
5473 -------------------------
5475 procedure Find_Negation_Types
5480 Index : Interp_Index;
5484 if not Is_Overloaded (R) then
5485 if Etype (R) = Universal_Integer then
5486 Add_One_Interp (N, Op_Id, Any_Modular);
5487 elsif Valid_Boolean_Arg (Etype (R)) then
5488 Add_One_Interp (N, Op_Id, Etype (R));
5492 Get_First_Interp (R, Index, It);
5493 while Present (It.Typ) loop
5494 if Valid_Boolean_Arg (It.Typ) then
5495 Add_One_Interp (N, Op_Id, It.Typ);
5498 Get_Next_Interp (Index, It);
5501 end Find_Negation_Types;
5503 ------------------------------
5504 -- Find_Primitive_Operation --
5505 ------------------------------
5507 function Find_Primitive_Operation (N : Node_Id) return Boolean is
5508 Obj : constant Node_Id := Prefix (N);
5509 Op : constant Node_Id := Selector_Name (N);
5516 Set_Etype (Op, Any_Type);
5518 if Is_Access_Type (Etype (Obj)) then
5519 Typ := Designated_Type (Etype (Obj));
5524 if Is_Class_Wide_Type (Typ) then
5525 Typ := Root_Type (Typ);
5528 Prims := Primitive_Operations (Typ);
5530 Prim := First_Elmt (Prims);
5531 while Present (Prim) loop
5532 if Chars (Node (Prim)) = Chars (Op) then
5533 Add_One_Interp (Op, Node (Prim), Etype (Node (Prim)));
5534 Set_Etype (N, Etype (Node (Prim)));
5540 -- Now look for class-wide operations of the type or any of its
5541 -- ancestors by iterating over the homonyms of the selector.
5544 Cls_Type : constant Entity_Id := Class_Wide_Type (Typ);
5548 Hom := Current_Entity (Op);
5549 while Present (Hom) loop
5550 if (Ekind (Hom) = E_Procedure
5552 Ekind (Hom) = E_Function)
5553 and then Scope (Hom) = Scope (Typ)
5554 and then Present (First_Formal (Hom))
5556 (Base_Type (Etype (First_Formal (Hom))) = Cls_Type
5558 (Is_Access_Type (Etype (First_Formal (Hom)))
5560 Ekind (Etype (First_Formal (Hom))) =
5561 E_Anonymous_Access_Type
5564 (Designated_Type (Etype (First_Formal (Hom)))) =
5567 Add_One_Interp (Op, Hom, Etype (Hom));
5568 Set_Etype (N, Etype (Hom));
5571 Hom := Homonym (Hom);
5575 return Etype (Op) /= Any_Type;
5576 end Find_Primitive_Operation;
5578 ----------------------
5579 -- Find_Unary_Types --
5580 ----------------------
5582 procedure Find_Unary_Types
5587 Index : Interp_Index;
5591 if not Is_Overloaded (R) then
5592 if Is_Numeric_Type (Etype (R)) then
5593 Add_One_Interp (N, Op_Id, Base_Type (Etype (R)));
5597 Get_First_Interp (R, Index, It);
5598 while Present (It.Typ) loop
5599 if Is_Numeric_Type (It.Typ) then
5600 Add_One_Interp (N, Op_Id, Base_Type (It.Typ));
5603 Get_Next_Interp (Index, It);
5606 end Find_Unary_Types;
5612 function Junk_Operand (N : Node_Id) return Boolean is
5616 if Error_Posted (N) then
5620 -- Get entity to be tested
5622 if Is_Entity_Name (N)
5623 and then Present (Entity (N))
5627 -- An odd case, a procedure name gets converted to a very peculiar
5628 -- function call, and here is where we detect this happening.
5630 elsif Nkind (N) = N_Function_Call
5631 and then Is_Entity_Name (Name (N))
5632 and then Present (Entity (Name (N)))
5636 -- Another odd case, there are at least some cases of selected
5637 -- components where the selected component is not marked as having
5638 -- an entity, even though the selector does have an entity
5640 elsif Nkind (N) = N_Selected_Component
5641 and then Present (Entity (Selector_Name (N)))
5643 Enode := Selector_Name (N);
5649 -- Now test the entity we got to see if it is a bad case
5651 case Ekind (Entity (Enode)) is
5655 ("package name cannot be used as operand", Enode);
5657 when Generic_Unit_Kind =>
5659 ("generic unit name cannot be used as operand", Enode);
5663 ("subtype name cannot be used as operand", Enode);
5667 ("entry name cannot be used as operand", Enode);
5671 ("procedure name cannot be used as operand", Enode);
5675 ("exception name cannot be used as operand", Enode);
5677 when E_Block | E_Label | E_Loop =>
5679 ("label name cannot be used as operand", Enode);
5689 --------------------
5690 -- Operator_Check --
5691 --------------------
5693 procedure Operator_Check (N : Node_Id) is
5695 Remove_Abstract_Operations (N);
5697 -- Test for case of no interpretation found for operator
5699 if Etype (N) = Any_Type then
5703 Op_Id : Entity_Id := Empty;
5706 R := Right_Opnd (N);
5708 if Nkind (N) in N_Binary_Op then
5714 -- If either operand has no type, then don't complain further,
5715 -- since this simply means that we have a propagated error.
5718 or else Etype (R) = Any_Type
5719 or else (Nkind (N) in N_Binary_Op and then Etype (L) = Any_Type)
5723 -- We explicitly check for the case of concatenation of component
5724 -- with component to avoid reporting spurious matching array types
5725 -- that might happen to be lurking in distant packages (such as
5726 -- run-time packages). This also prevents inconsistencies in the
5727 -- messages for certain ACVC B tests, which can vary depending on
5728 -- types declared in run-time interfaces. Another improvement when
5729 -- aggregates are present is to look for a well-typed operand.
5731 elsif Present (Candidate_Type)
5732 and then (Nkind (N) /= N_Op_Concat
5733 or else Is_Array_Type (Etype (L))
5734 or else Is_Array_Type (Etype (R)))
5736 if Nkind (N) = N_Op_Concat then
5737 if Etype (L) /= Any_Composite
5738 and then Is_Array_Type (Etype (L))
5740 Candidate_Type := Etype (L);
5742 elsif Etype (R) /= Any_Composite
5743 and then Is_Array_Type (Etype (R))
5745 Candidate_Type := Etype (R);
5749 Error_Msg_NE -- CODEFIX
5750 ("operator for} is not directly visible!",
5751 N, First_Subtype (Candidate_Type));
5754 U : constant Node_Id :=
5755 Cunit (Get_Source_Unit (Candidate_Type));
5757 if Unit_Is_Visible (U) then
5758 Error_Msg_N -- CODEFIX
5759 ("use clause would make operation legal!", N);
5761 Error_Msg_NE -- CODEFIX
5762 ("add with_clause and use_clause for&!",
5763 N, Defining_Entity (Unit (U)));
5768 -- If either operand is a junk operand (e.g. package name), then
5769 -- post appropriate error messages, but do not complain further.
5771 -- Note that the use of OR in this test instead of OR ELSE is
5772 -- quite deliberate, we may as well check both operands in the
5773 -- binary operator case.
5775 elsif Junk_Operand (R)
5776 or (Nkind (N) in N_Binary_Op and then Junk_Operand (L))
5780 -- If we have a logical operator, one of whose operands is
5781 -- Boolean, then we know that the other operand cannot resolve to
5782 -- Boolean (since we got no interpretations), but in that case we
5783 -- pretty much know that the other operand should be Boolean, so
5784 -- resolve it that way (generating an error)
5786 elsif Nkind_In (N, N_Op_And, N_Op_Or, N_Op_Xor) then
5787 if Etype (L) = Standard_Boolean then
5788 Resolve (R, Standard_Boolean);
5790 elsif Etype (R) = Standard_Boolean then
5791 Resolve (L, Standard_Boolean);
5795 -- For an arithmetic operator or comparison operator, if one
5796 -- of the operands is numeric, then we know the other operand
5797 -- is not the same numeric type. If it is a non-numeric type,
5798 -- then probably it is intended to match the other operand.
5800 elsif Nkind_In (N, N_Op_Add,
5806 Nkind_In (N, N_Op_Lt,
5812 if Is_Numeric_Type (Etype (L))
5813 and then not Is_Numeric_Type (Etype (R))
5815 Resolve (R, Etype (L));
5818 elsif Is_Numeric_Type (Etype (R))
5819 and then not Is_Numeric_Type (Etype (L))
5821 Resolve (L, Etype (R));
5825 -- Comparisons on A'Access are common enough to deserve a
5828 elsif Nkind_In (N, N_Op_Eq, N_Op_Ne)
5829 and then Ekind (Etype (L)) = E_Access_Attribute_Type
5830 and then Ekind (Etype (R)) = E_Access_Attribute_Type
5833 ("two access attributes cannot be compared directly", N);
5835 ("\use qualified expression for one of the operands",
5839 -- Another one for C programmers
5841 elsif Nkind (N) = N_Op_Concat
5842 and then Valid_Boolean_Arg (Etype (L))
5843 and then Valid_Boolean_Arg (Etype (R))
5845 Error_Msg_N ("invalid operands for concatenation", N);
5846 Error_Msg_N -- CODEFIX
5847 ("\maybe AND was meant", N);
5850 -- A special case for comparison of access parameter with null
5852 elsif Nkind (N) = N_Op_Eq
5853 and then Is_Entity_Name (L)
5854 and then Nkind (Parent (Entity (L))) = N_Parameter_Specification
5855 and then Nkind (Parameter_Type (Parent (Entity (L)))) =
5857 and then Nkind (R) = N_Null
5859 Error_Msg_N ("access parameter is not allowed to be null", L);
5860 Error_Msg_N ("\(call would raise Constraint_Error)", L);
5863 -- Another special case for exponentiation, where the right
5864 -- operand must be Natural, independently of the base.
5866 elsif Nkind (N) = N_Op_Expon
5867 and then Is_Numeric_Type (Etype (L))
5868 and then not Is_Overloaded (R)
5870 First_Subtype (Base_Type (Etype (R))) /= Standard_Integer
5871 and then Base_Type (Etype (R)) /= Universal_Integer
5874 ("exponent must be of type Natural, found}", R, Etype (R));
5878 -- If we fall through then just give general message. Note that in
5879 -- the following messages, if the operand is overloaded we choose
5880 -- an arbitrary type to complain about, but that is probably more
5881 -- useful than not giving a type at all.
5883 if Nkind (N) in N_Unary_Op then
5884 Error_Msg_Node_2 := Etype (R);
5885 Error_Msg_N ("operator& not defined for}", N);
5889 if Nkind (N) in N_Binary_Op then
5890 if not Is_Overloaded (L)
5891 and then not Is_Overloaded (R)
5892 and then Base_Type (Etype (L)) = Base_Type (Etype (R))
5894 Error_Msg_Node_2 := First_Subtype (Etype (R));
5895 Error_Msg_N ("there is no applicable operator& for}", N);
5898 -- Another attempt to find a fix: one of the candidate
5899 -- interpretations may not be use-visible. This has
5900 -- already been checked for predefined operators, so
5901 -- we examine only user-defined functions.
5903 Op_Id := Get_Name_Entity_Id (Chars (N));
5905 while Present (Op_Id) loop
5906 if Ekind (Op_Id) /= E_Operator
5907 and then Is_Overloadable (Op_Id)
5909 if not Is_Immediately_Visible (Op_Id)
5910 and then not In_Use (Scope (Op_Id))
5911 and then not Is_Abstract_Subprogram (Op_Id)
5912 and then not Is_Hidden (Op_Id)
5913 and then Ekind (Scope (Op_Id)) = E_Package
5916 (L, Etype (First_Formal (Op_Id)))
5918 (Next_Formal (First_Formal (Op_Id)))
5922 Etype (Next_Formal (First_Formal (Op_Id))))
5925 ("No legal interpretation for operator&", N);
5927 ("\use clause on& would make operation legal",
5933 Op_Id := Homonym (Op_Id);
5937 Error_Msg_N ("invalid operand types for operator&", N);
5939 if Nkind (N) /= N_Op_Concat then
5940 Error_Msg_NE ("\left operand has}!", N, Etype (L));
5941 Error_Msg_NE ("\right operand has}!", N, Etype (R));
5951 -----------------------------------------
5952 -- Process_Implicit_Dereference_Prefix --
5953 -----------------------------------------
5955 function Process_Implicit_Dereference_Prefix
5957 P : Entity_Id) return Entity_Id
5960 Typ : constant Entity_Id := Designated_Type (Etype (P));
5964 and then (Operating_Mode = Check_Semantics or else not Expander_Active)
5966 -- We create a dummy reference to E to ensure that the reference
5967 -- is not considered as part of an assignment (an implicit
5968 -- dereference can never assign to its prefix). The Comes_From_Source
5969 -- attribute needs to be propagated for accurate warnings.
5971 Ref := New_Reference_To (E, Sloc (P));
5972 Set_Comes_From_Source (Ref, Comes_From_Source (P));
5973 Generate_Reference (E, Ref);
5976 -- An implicit dereference is a legal occurrence of an
5977 -- incomplete type imported through a limited_with clause,
5978 -- if the full view is visible.
5980 if From_With_Type (Typ)
5981 and then not From_With_Type (Scope (Typ))
5983 (Is_Immediately_Visible (Scope (Typ))
5985 (Is_Child_Unit (Scope (Typ))
5986 and then Is_Visible_Child_Unit (Scope (Typ))))
5988 return Available_View (Typ);
5993 end Process_Implicit_Dereference_Prefix;
5995 --------------------------------
5996 -- Remove_Abstract_Operations --
5997 --------------------------------
5999 procedure Remove_Abstract_Operations (N : Node_Id) is
6000 Abstract_Op : Entity_Id := Empty;
6001 Address_Kludge : Boolean := False;
6005 -- AI-310: If overloaded, remove abstract non-dispatching operations. We
6006 -- activate this if either extensions are enabled, or if the abstract
6007 -- operation in question comes from a predefined file. This latter test
6008 -- allows us to use abstract to make operations invisible to users. In
6009 -- particular, if type Address is non-private and abstract subprograms
6010 -- are used to hide its operators, they will be truly hidden.
6012 type Operand_Position is (First_Op, Second_Op);
6013 Univ_Type : constant Entity_Id := Universal_Interpretation (N);
6015 procedure Remove_Address_Interpretations (Op : Operand_Position);
6016 -- Ambiguities may arise when the operands are literal and the address
6017 -- operations in s-auxdec are visible. In that case, remove the
6018 -- interpretation of a literal as Address, to retain the semantics of
6019 -- Address as a private type.
6021 ------------------------------------
6022 -- Remove_Address_Interpretations --
6023 ------------------------------------
6025 procedure Remove_Address_Interpretations (Op : Operand_Position) is
6029 if Is_Overloaded (N) then
6030 Get_First_Interp (N, I, It);
6031 while Present (It.Nam) loop
6032 Formal := First_Entity (It.Nam);
6034 if Op = Second_Op then
6035 Formal := Next_Entity (Formal);
6038 if Is_Descendent_Of_Address (Etype (Formal)) then
6039 Address_Kludge := True;
6043 Get_Next_Interp (I, It);
6046 end Remove_Address_Interpretations;
6048 -- Start of processing for Remove_Abstract_Operations
6051 if Is_Overloaded (N) then
6052 Get_First_Interp (N, I, It);
6054 while Present (It.Nam) loop
6055 if Is_Overloadable (It.Nam)
6056 and then Is_Abstract_Subprogram (It.Nam)
6057 and then not Is_Dispatching_Operation (It.Nam)
6059 Abstract_Op := It.Nam;
6061 if Is_Descendent_Of_Address (It.Typ) then
6062 Address_Kludge := True;
6066 -- In Ada 2005, this operation does not participate in Overload
6067 -- resolution. If the operation is defined in a predefined
6068 -- unit, it is one of the operations declared abstract in some
6069 -- variants of System, and it must be removed as well.
6071 elsif Ada_Version >= Ada_2005
6072 or else Is_Predefined_File_Name
6073 (Unit_File_Name (Get_Source_Unit (It.Nam)))
6080 Get_Next_Interp (I, It);
6083 if No (Abstract_Op) then
6085 -- If some interpretation yields an integer type, it is still
6086 -- possible that there are address interpretations. Remove them
6087 -- if one operand is a literal, to avoid spurious ambiguities
6088 -- on systems where Address is a visible integer type.
6090 if Is_Overloaded (N)
6091 and then Nkind (N) in N_Op
6092 and then Is_Integer_Type (Etype (N))
6094 if Nkind (N) in N_Binary_Op then
6095 if Nkind (Right_Opnd (N)) = N_Integer_Literal then
6096 Remove_Address_Interpretations (Second_Op);
6098 elsif Nkind (Right_Opnd (N)) = N_Integer_Literal then
6099 Remove_Address_Interpretations (First_Op);
6104 elsif Nkind (N) in N_Op then
6106 -- Remove interpretations that treat literals as addresses. This
6107 -- is never appropriate, even when Address is defined as a visible
6108 -- Integer type. The reason is that we would really prefer Address
6109 -- to behave as a private type, even in this case, which is there
6110 -- only to accommodate oddities of VMS address sizes. If Address
6111 -- is a visible integer type, we get lots of overload ambiguities.
6113 if Nkind (N) in N_Binary_Op then
6115 U1 : constant Boolean :=
6116 Present (Universal_Interpretation (Right_Opnd (N)));
6117 U2 : constant Boolean :=
6118 Present (Universal_Interpretation (Left_Opnd (N)));
6122 Remove_Address_Interpretations (Second_Op);
6126 Remove_Address_Interpretations (First_Op);
6129 if not (U1 and U2) then
6131 -- Remove corresponding predefined operator, which is
6132 -- always added to the overload set.
6134 Get_First_Interp (N, I, It);
6135 while Present (It.Nam) loop
6136 if Scope (It.Nam) = Standard_Standard
6137 and then Base_Type (It.Typ) =
6138 Base_Type (Etype (Abstract_Op))
6143 Get_Next_Interp (I, It);
6146 elsif Is_Overloaded (N)
6147 and then Present (Univ_Type)
6149 -- If both operands have a universal interpretation,
6150 -- it is still necessary to remove interpretations that
6151 -- yield Address. Any remaining ambiguities will be
6152 -- removed in Disambiguate.
6154 Get_First_Interp (N, I, It);
6155 while Present (It.Nam) loop
6156 if Is_Descendent_Of_Address (It.Typ) then
6159 elsif not Is_Type (It.Nam) then
6160 Set_Entity (N, It.Nam);
6163 Get_Next_Interp (I, It);
6169 elsif Nkind (N) = N_Function_Call
6171 (Nkind (Name (N)) = N_Operator_Symbol
6173 (Nkind (Name (N)) = N_Expanded_Name
6175 Nkind (Selector_Name (Name (N))) = N_Operator_Symbol))
6179 Arg1 : constant Node_Id := First (Parameter_Associations (N));
6180 U1 : constant Boolean :=
6181 Present (Universal_Interpretation (Arg1));
6182 U2 : constant Boolean :=
6183 Present (Next (Arg1)) and then
6184 Present (Universal_Interpretation (Next (Arg1)));
6188 Remove_Address_Interpretations (First_Op);
6192 Remove_Address_Interpretations (Second_Op);
6195 if not (U1 and U2) then
6196 Get_First_Interp (N, I, It);
6197 while Present (It.Nam) loop
6198 if Scope (It.Nam) = Standard_Standard
6199 and then It.Typ = Base_Type (Etype (Abstract_Op))
6204 Get_Next_Interp (I, It);
6210 -- If the removal has left no valid interpretations, emit an error
6211 -- message now and label node as illegal.
6213 if Present (Abstract_Op) then
6214 Get_First_Interp (N, I, It);
6218 -- Removal of abstract operation left no viable candidate
6220 Set_Etype (N, Any_Type);
6221 Error_Msg_Sloc := Sloc (Abstract_Op);
6223 ("cannot call abstract operation& declared#", N, Abstract_Op);
6225 -- In Ada 2005, an abstract operation may disable predefined
6226 -- operators. Since the context is not yet known, we mark the
6227 -- predefined operators as potentially hidden. Do not include
6228 -- predefined operators when addresses are involved since this
6229 -- case is handled separately.
6231 elsif Ada_Version >= Ada_2005
6232 and then not Address_Kludge
6234 while Present (It.Nam) loop
6235 if Is_Numeric_Type (It.Typ)
6236 and then Scope (It.Typ) = Standard_Standard
6238 Set_Abstract_Op (I, Abstract_Op);
6241 Get_Next_Interp (I, It);
6246 end Remove_Abstract_Operations;
6248 -----------------------
6249 -- Try_Indirect_Call --
6250 -----------------------
6252 function Try_Indirect_Call
6255 Typ : Entity_Id) return Boolean
6261 pragma Warnings (Off, Call_OK);
6264 Normalize_Actuals (N, Designated_Type (Typ), False, Call_OK);
6266 Actual := First_Actual (N);
6267 Formal := First_Formal (Designated_Type (Typ));
6268 while Present (Actual) and then Present (Formal) loop
6269 if not Has_Compatible_Type (Actual, Etype (Formal)) then
6274 Next_Formal (Formal);
6277 if No (Actual) and then No (Formal) then
6278 Add_One_Interp (N, Nam, Etype (Designated_Type (Typ)));
6280 -- Nam is a candidate interpretation for the name in the call,
6281 -- if it is not an indirect call.
6283 if not Is_Type (Nam)
6284 and then Is_Entity_Name (Name (N))
6286 Set_Entity (Name (N), Nam);
6293 end Try_Indirect_Call;
6295 ----------------------
6296 -- Try_Indexed_Call --
6297 ----------------------
6299 function Try_Indexed_Call
6303 Skip_First : Boolean) return Boolean
6305 Loc : constant Source_Ptr := Sloc (N);
6306 Actuals : constant List_Id := Parameter_Associations (N);
6311 Actual := First (Actuals);
6313 -- If the call was originally written in prefix form, skip the first
6314 -- actual, which is obviously not defaulted.
6320 Index := First_Index (Typ);
6321 while Present (Actual) and then Present (Index) loop
6323 -- If the parameter list has a named association, the expression
6324 -- is definitely a call and not an indexed component.
6326 if Nkind (Actual) = N_Parameter_Association then
6330 if Is_Entity_Name (Actual)
6331 and then Is_Type (Entity (Actual))
6332 and then No (Next (Actual))
6334 -- A single actual that is a type name indicates a slice if the
6335 -- type is discrete, and an error otherwise.
6337 if Is_Discrete_Type (Entity (Actual)) then
6341 Make_Function_Call (Loc,
6342 Name => Relocate_Node (Name (N))),
6344 New_Occurrence_Of (Entity (Actual), Sloc (Actual))));
6349 Error_Msg_N ("invalid use of type in expression", Actual);
6350 Set_Etype (N, Any_Type);
6355 elsif not Has_Compatible_Type (Actual, Etype (Index)) then
6363 if No (Actual) and then No (Index) then
6364 Add_One_Interp (N, Nam, Component_Type (Typ));
6366 -- Nam is a candidate interpretation for the name in the call,
6367 -- if it is not an indirect call.
6369 if not Is_Type (Nam)
6370 and then Is_Entity_Name (Name (N))
6372 Set_Entity (Name (N), Nam);
6379 end Try_Indexed_Call;
6381 --------------------------
6382 -- Try_Object_Operation --
6383 --------------------------
6385 function Try_Object_Operation (N : Node_Id) return Boolean is
6386 K : constant Node_Kind := Nkind (Parent (N));
6387 Is_Subprg_Call : constant Boolean := Nkind_In
6388 (K, N_Procedure_Call_Statement,
6390 Loc : constant Source_Ptr := Sloc (N);
6391 Obj : constant Node_Id := Prefix (N);
6393 Subprog : constant Node_Id :=
6394 Make_Identifier (Sloc (Selector_Name (N)),
6395 Chars => Chars (Selector_Name (N)));
6396 -- Identifier on which possible interpretations will be collected
6398 Report_Error : Boolean := False;
6399 -- If no candidate interpretation matches the context, redo the
6400 -- analysis with error enabled to provide additional information.
6403 Candidate : Entity_Id := Empty;
6404 New_Call_Node : Node_Id := Empty;
6405 Node_To_Replace : Node_Id;
6406 Obj_Type : Entity_Id := Etype (Obj);
6407 Success : Boolean := False;
6409 function Valid_Candidate
6412 Subp : Entity_Id) return Entity_Id;
6413 -- If the subprogram is a valid interpretation, record it, and add
6414 -- to the list of interpretations of Subprog.
6416 procedure Complete_Object_Operation
6417 (Call_Node : Node_Id;
6418 Node_To_Replace : Node_Id);
6419 -- Make Subprog the name of Call_Node, replace Node_To_Replace with
6420 -- Call_Node, insert the object (or its dereference) as the first actual
6421 -- in the call, and complete the analysis of the call.
6423 procedure Report_Ambiguity (Op : Entity_Id);
6424 -- If a prefixed procedure call is ambiguous, indicate whether the
6425 -- call includes an implicit dereference or an implicit 'Access.
6427 procedure Transform_Object_Operation
6428 (Call_Node : out Node_Id;
6429 Node_To_Replace : out Node_Id);
6430 -- Transform Obj.Operation (X, Y,,) into Operation (Obj, X, Y ..)
6431 -- Call_Node is the resulting subprogram call, Node_To_Replace is
6432 -- either N or the parent of N, and Subprog is a reference to the
6433 -- subprogram we are trying to match.
6435 function Try_Class_Wide_Operation
6436 (Call_Node : Node_Id;
6437 Node_To_Replace : Node_Id) return Boolean;
6438 -- Traverse all ancestor types looking for a class-wide subprogram
6439 -- for which the current operation is a valid non-dispatching call.
6441 procedure Try_One_Prefix_Interpretation (T : Entity_Id);
6442 -- If prefix is overloaded, its interpretation may include different
6443 -- tagged types, and we must examine the primitive operations and
6444 -- the class-wide operations of each in order to find candidate
6445 -- interpretations for the call as a whole.
6447 function Try_Primitive_Operation
6448 (Call_Node : Node_Id;
6449 Node_To_Replace : Node_Id) return Boolean;
6450 -- Traverse the list of primitive subprograms looking for a dispatching
6451 -- operation for which the current node is a valid call .
6453 ---------------------
6454 -- Valid_Candidate --
6455 ---------------------
6457 function Valid_Candidate
6460 Subp : Entity_Id) return Entity_Id
6462 Arr_Type : Entity_Id;
6463 Comp_Type : Entity_Id;
6466 -- If the subprogram is a valid interpretation, record it in global
6467 -- variable Subprog, to collect all possible overloadings.
6470 if Subp /= Entity (Subprog) then
6471 Add_One_Interp (Subprog, Subp, Etype (Subp));
6475 -- If the call may be an indexed call, retrieve component type of
6476 -- resulting expression, and add possible interpretation.
6481 if Nkind (Call) = N_Function_Call
6482 and then Nkind (Parent (N)) = N_Indexed_Component
6483 and then Needs_One_Actual (Subp)
6485 if Is_Array_Type (Etype (Subp)) then
6486 Arr_Type := Etype (Subp);
6488 elsif Is_Access_Type (Etype (Subp))
6489 and then Is_Array_Type (Designated_Type (Etype (Subp)))
6491 Arr_Type := Designated_Type (Etype (Subp));
6495 if Present (Arr_Type) then
6497 -- Verify that the actuals (excluding the object) match the types
6505 Actual := Next (First_Actual (Call));
6506 Index := First_Index (Arr_Type);
6507 while Present (Actual) and then Present (Index) loop
6508 if not Has_Compatible_Type (Actual, Etype (Index)) then
6513 Next_Actual (Actual);
6519 and then Present (Arr_Type)
6521 Comp_Type := Component_Type (Arr_Type);
6525 if Present (Comp_Type)
6526 and then Etype (Subprog) /= Comp_Type
6528 Add_One_Interp (Subprog, Subp, Comp_Type);
6532 if Etype (Call) /= Any_Type then
6537 end Valid_Candidate;
6539 -------------------------------
6540 -- Complete_Object_Operation --
6541 -------------------------------
6543 procedure Complete_Object_Operation
6544 (Call_Node : Node_Id;
6545 Node_To_Replace : Node_Id)
6547 Control : constant Entity_Id := First_Formal (Entity (Subprog));
6548 Formal_Type : constant Entity_Id := Etype (Control);
6549 First_Actual : Node_Id;
6552 -- Place the name of the operation, with its interpretations,
6553 -- on the rewritten call.
6555 Set_Name (Call_Node, Subprog);
6557 First_Actual := First (Parameter_Associations (Call_Node));
6559 -- For cross-reference purposes, treat the new node as being in
6560 -- the source if the original one is.
6562 Set_Comes_From_Source (Subprog, Comes_From_Source (N));
6563 Set_Comes_From_Source (Call_Node, Comes_From_Source (N));
6565 if Nkind (N) = N_Selected_Component
6566 and then not Inside_A_Generic
6568 Set_Entity (Selector_Name (N), Entity (Subprog));
6571 -- If need be, rewrite first actual as an explicit dereference
6572 -- If the call is overloaded, the rewriting can only be done
6573 -- once the primitive operation is identified.
6575 if Is_Overloaded (Subprog) then
6577 -- The prefix itself may be overloaded, and its interpretations
6578 -- must be propagated to the new actual in the call.
6580 if Is_Overloaded (Obj) then
6581 Save_Interps (Obj, First_Actual);
6584 Rewrite (First_Actual, Obj);
6586 elsif not Is_Access_Type (Formal_Type)
6587 and then Is_Access_Type (Etype (Obj))
6589 Rewrite (First_Actual,
6590 Make_Explicit_Dereference (Sloc (Obj), Obj));
6591 Analyze (First_Actual);
6593 -- If we need to introduce an explicit dereference, verify that
6594 -- the resulting actual is compatible with the mode of the formal.
6596 if Ekind (First_Formal (Entity (Subprog))) /= E_In_Parameter
6597 and then Is_Access_Constant (Etype (Obj))
6600 ("expect variable in call to&", Prefix (N), Entity (Subprog));
6603 -- Conversely, if the formal is an access parameter and the object
6604 -- is not, replace the actual with a 'Access reference. Its analysis
6605 -- will check that the object is aliased.
6607 elsif Is_Access_Type (Formal_Type)
6608 and then not Is_Access_Type (Etype (Obj))
6610 -- A special case: A.all'access is illegal if A is an access to a
6611 -- constant and the context requires an access to a variable.
6613 if not Is_Access_Constant (Formal_Type) then
6614 if (Nkind (Obj) = N_Explicit_Dereference
6615 and then Is_Access_Constant (Etype (Prefix (Obj))))
6616 or else not Is_Variable (Obj)
6619 ("actual for& must be a variable", Obj, Control);
6623 Rewrite (First_Actual,
6624 Make_Attribute_Reference (Loc,
6625 Attribute_Name => Name_Access,
6626 Prefix => Relocate_Node (Obj)));
6628 if not Is_Aliased_View (Obj) then
6630 ("object in prefixed call to& must be aliased"
6631 & " (RM-2005 4.3.1 (13))",
6632 Prefix (First_Actual), Subprog);
6635 Analyze (First_Actual);
6638 if Is_Overloaded (Obj) then
6639 Save_Interps (Obj, First_Actual);
6642 Rewrite (First_Actual, Obj);
6645 Rewrite (Node_To_Replace, Call_Node);
6647 -- Propagate the interpretations collected in subprog to the new
6648 -- function call node, to be resolved from context.
6650 if Is_Overloaded (Subprog) then
6651 Save_Interps (Subprog, Node_To_Replace);
6654 Analyze (Node_To_Replace);
6656 -- If the operation has been rewritten into a call, which may get
6657 -- subsequently an explicit dereference, preserve the type on the
6658 -- original node (selected component or indexed component) for
6659 -- subsequent legality tests, e.g. Is_Variable. which examines
6660 -- the original node.
6662 if Nkind (Node_To_Replace) = N_Function_Call then
6664 (Original_Node (Node_To_Replace), Etype (Node_To_Replace));
6667 end Complete_Object_Operation;
6669 ----------------------
6670 -- Report_Ambiguity --
6671 ----------------------
6673 procedure Report_Ambiguity (Op : Entity_Id) is
6674 Access_Formal : constant Boolean :=
6675 Is_Access_Type (Etype (First_Formal (Op)));
6676 Access_Actual : constant Boolean :=
6677 Is_Access_Type (Etype (Prefix (N)));
6680 Error_Msg_Sloc := Sloc (Op);
6682 if Access_Formal and then not Access_Actual then
6683 if Nkind (Parent (Op)) = N_Full_Type_Declaration then
6685 ("\possible interpretation"
6686 & " (inherited, with implicit 'Access) #", N);
6689 ("\possible interpretation (with implicit 'Access) #", N);
6692 elsif not Access_Formal and then Access_Actual then
6693 if Nkind (Parent (Op)) = N_Full_Type_Declaration then
6695 ("\possible interpretation"
6696 & " ( inherited, with implicit dereference) #", N);
6699 ("\possible interpretation (with implicit dereference) #", N);
6703 if Nkind (Parent (Op)) = N_Full_Type_Declaration then
6704 Error_Msg_N ("\possible interpretation (inherited)#", N);
6706 Error_Msg_N -- CODEFIX
6707 ("\possible interpretation#", N);
6710 end Report_Ambiguity;
6712 --------------------------------
6713 -- Transform_Object_Operation --
6714 --------------------------------
6716 procedure Transform_Object_Operation
6717 (Call_Node : out Node_Id;
6718 Node_To_Replace : out Node_Id)
6720 Dummy : constant Node_Id := New_Copy (Obj);
6721 -- Placeholder used as a first parameter in the call, replaced
6722 -- eventually by the proper object.
6724 Parent_Node : constant Node_Id := Parent (N);
6730 -- Common case covering 1) Call to a procedure and 2) Call to a
6731 -- function that has some additional actuals.
6733 if Nkind_In (Parent_Node, N_Function_Call,
6734 N_Procedure_Call_Statement)
6736 -- N is a selected component node containing the name of the
6737 -- subprogram. If N is not the name of the parent node we must
6738 -- not replace the parent node by the new construct. This case
6739 -- occurs when N is a parameterless call to a subprogram that
6740 -- is an actual parameter of a call to another subprogram. For
6742 -- Some_Subprogram (..., Obj.Operation, ...)
6744 and then Name (Parent_Node) = N
6746 Node_To_Replace := Parent_Node;
6748 Actuals := Parameter_Associations (Parent_Node);
6750 if Present (Actuals) then
6751 Prepend (Dummy, Actuals);
6753 Actuals := New_List (Dummy);
6756 if Nkind (Parent_Node) = N_Procedure_Call_Statement then
6758 Make_Procedure_Call_Statement (Loc,
6759 Name => New_Copy (Subprog),
6760 Parameter_Associations => Actuals);
6764 Make_Function_Call (Loc,
6765 Name => New_Copy (Subprog),
6766 Parameter_Associations => Actuals);
6770 -- Before analysis, a function call appears as an indexed component
6771 -- if there are no named associations.
6773 elsif Nkind (Parent_Node) = N_Indexed_Component
6774 and then N = Prefix (Parent_Node)
6776 Node_To_Replace := Parent_Node;
6777 Actuals := Expressions (Parent_Node);
6779 Actual := First (Actuals);
6780 while Present (Actual) loop
6785 Prepend (Dummy, Actuals);
6788 Make_Function_Call (Loc,
6789 Name => New_Copy (Subprog),
6790 Parameter_Associations => Actuals);
6792 -- Parameterless call: Obj.F is rewritten as F (Obj)
6795 Node_To_Replace := N;
6798 Make_Function_Call (Loc,
6799 Name => New_Copy (Subprog),
6800 Parameter_Associations => New_List (Dummy));
6802 end Transform_Object_Operation;
6804 ------------------------------
6805 -- Try_Class_Wide_Operation --
6806 ------------------------------
6808 function Try_Class_Wide_Operation
6809 (Call_Node : Node_Id;
6810 Node_To_Replace : Node_Id) return Boolean
6812 Anc_Type : Entity_Id;
6813 Matching_Op : Entity_Id := Empty;
6816 procedure Traverse_Homonyms
6817 (Anc_Type : Entity_Id;
6818 Error : out Boolean);
6819 -- Traverse the homonym chain of the subprogram searching for those
6820 -- homonyms whose first formal has the Anc_Type's class-wide type,
6821 -- or an anonymous access type designating the class-wide type. If
6822 -- an ambiguity is detected, then Error is set to True.
6824 procedure Traverse_Interfaces
6825 (Anc_Type : Entity_Id;
6826 Error : out Boolean);
6827 -- Traverse the list of interfaces, if any, associated with Anc_Type
6828 -- and search for acceptable class-wide homonyms associated with each
6829 -- interface. If an ambiguity is detected, then Error is set to True.
6831 -----------------------
6832 -- Traverse_Homonyms --
6833 -----------------------
6835 procedure Traverse_Homonyms
6836 (Anc_Type : Entity_Id;
6837 Error : out Boolean)
6839 Cls_Type : Entity_Id;
6847 Cls_Type := Class_Wide_Type (Anc_Type);
6849 Hom := Current_Entity (Subprog);
6851 -- Find a non-hidden operation whose first parameter is of the
6852 -- class-wide type, a subtype thereof, or an anonymous access
6855 while Present (Hom) loop
6856 if Ekind_In (Hom, E_Procedure, E_Function)
6857 and then not Is_Hidden (Hom)
6858 and then Scope (Hom) = Scope (Anc_Type)
6859 and then Present (First_Formal (Hom))
6861 (Base_Type (Etype (First_Formal (Hom))) = Cls_Type
6863 (Is_Access_Type (Etype (First_Formal (Hom)))
6865 Ekind (Etype (First_Formal (Hom))) =
6866 E_Anonymous_Access_Type
6869 (Designated_Type (Etype (First_Formal (Hom)))) =
6872 Set_Etype (Call_Node, Any_Type);
6873 Set_Is_Overloaded (Call_Node, False);
6876 if No (Matching_Op) then
6877 Hom_Ref := New_Reference_To (Hom, Sloc (Subprog));
6878 Set_Etype (Call_Node, Any_Type);
6879 Set_Parent (Call_Node, Parent (Node_To_Replace));
6881 Set_Name (Call_Node, Hom_Ref);
6886 Report => Report_Error,
6888 Skip_First => True);
6891 Valid_Candidate (Success, Call_Node, Hom);
6897 Report => Report_Error,
6899 Skip_First => True);
6901 if Present (Valid_Candidate (Success, Call_Node, Hom))
6902 and then Nkind (Call_Node) /= N_Function_Call
6904 Error_Msg_NE ("ambiguous call to&", N, Hom);
6905 Report_Ambiguity (Matching_Op);
6906 Report_Ambiguity (Hom);
6913 Hom := Homonym (Hom);
6915 end Traverse_Homonyms;
6917 -------------------------
6918 -- Traverse_Interfaces --
6919 -------------------------
6921 procedure Traverse_Interfaces
6922 (Anc_Type : Entity_Id;
6923 Error : out Boolean)
6925 Intface_List : constant List_Id :=
6926 Abstract_Interface_List (Anc_Type);
6932 if Is_Non_Empty_List (Intface_List) then
6933 Intface := First (Intface_List);
6934 while Present (Intface) loop
6936 -- Look for acceptable class-wide homonyms associated with
6939 Traverse_Homonyms (Etype (Intface), Error);
6945 -- Continue the search by looking at each of the interface's
6946 -- associated interface ancestors.
6948 Traverse_Interfaces (Etype (Intface), Error);
6957 end Traverse_Interfaces;
6959 -- Start of processing for Try_Class_Wide_Operation
6962 -- Loop through ancestor types (including interfaces), traversing
6963 -- the homonym chain of the subprogram, trying out those homonyms
6964 -- whose first formal has the class-wide type of the ancestor, or
6965 -- an anonymous access type designating the class-wide type.
6967 Anc_Type := Obj_Type;
6969 -- Look for a match among homonyms associated with the ancestor
6971 Traverse_Homonyms (Anc_Type, Error);
6977 -- Continue the search for matches among homonyms associated with
6978 -- any interfaces implemented by the ancestor.
6980 Traverse_Interfaces (Anc_Type, Error);
6986 exit when Etype (Anc_Type) = Anc_Type;
6987 Anc_Type := Etype (Anc_Type);
6990 if Present (Matching_Op) then
6991 Set_Etype (Call_Node, Etype (Matching_Op));
6994 return Present (Matching_Op);
6995 end Try_Class_Wide_Operation;
6997 -----------------------------------
6998 -- Try_One_Prefix_Interpretation --
6999 -----------------------------------
7001 procedure Try_One_Prefix_Interpretation (T : Entity_Id) is
7005 if Is_Access_Type (Obj_Type) then
7006 Obj_Type := Designated_Type (Obj_Type);
7009 if Ekind (Obj_Type) = E_Private_Subtype then
7010 Obj_Type := Base_Type (Obj_Type);
7013 if Is_Class_Wide_Type (Obj_Type) then
7014 Obj_Type := Etype (Class_Wide_Type (Obj_Type));
7017 -- The type may have be obtained through a limited_with clause,
7018 -- in which case the primitive operations are available on its
7019 -- non-limited view. If still incomplete, retrieve full view.
7021 if Ekind (Obj_Type) = E_Incomplete_Type
7022 and then From_With_Type (Obj_Type)
7024 Obj_Type := Get_Full_View (Non_Limited_View (Obj_Type));
7027 -- If the object is not tagged, or the type is still an incomplete
7028 -- type, this is not a prefixed call.
7030 if not Is_Tagged_Type (Obj_Type)
7031 or else Is_Incomplete_Type (Obj_Type)
7036 if Try_Primitive_Operation
7037 (Call_Node => New_Call_Node,
7038 Node_To_Replace => Node_To_Replace)
7040 Try_Class_Wide_Operation
7041 (Call_Node => New_Call_Node,
7042 Node_To_Replace => Node_To_Replace)
7046 end Try_One_Prefix_Interpretation;
7048 -----------------------------
7049 -- Try_Primitive_Operation --
7050 -----------------------------
7052 function Try_Primitive_Operation
7053 (Call_Node : Node_Id;
7054 Node_To_Replace : Node_Id) return Boolean
7057 Prim_Op : Entity_Id;
7058 Matching_Op : Entity_Id := Empty;
7059 Prim_Op_Ref : Node_Id := Empty;
7061 Corr_Type : Entity_Id := Empty;
7062 -- If the prefix is a synchronized type, the controlling type of
7063 -- the primitive operation is the corresponding record type, else
7064 -- this is the object type itself.
7066 Success : Boolean := False;
7068 function Collect_Generic_Type_Ops (T : Entity_Id) return Elist_Id;
7069 -- For tagged types the candidate interpretations are found in
7070 -- the list of primitive operations of the type and its ancestors.
7071 -- For formal tagged types we have to find the operations declared
7072 -- in the same scope as the type (including in the generic formal
7073 -- part) because the type itself carries no primitive operations,
7074 -- except for formal derived types that inherit the operations of
7075 -- the parent and progenitors.
7076 -- If the context is a generic subprogram body, the generic formals
7077 -- are visible by name, but are not in the entity list of the
7078 -- subprogram because that list starts with the subprogram formals.
7079 -- We retrieve the candidate operations from the generic declaration.
7081 function Is_Private_Overriding (Op : Entity_Id) return Boolean;
7082 -- An operation that overrides an inherited operation in the private
7083 -- part of its package may be hidden, but if the inherited operation
7084 -- is visible a direct call to it will dispatch to the private one,
7085 -- which is therefore a valid candidate.
7087 function Valid_First_Argument_Of (Op : Entity_Id) return Boolean;
7088 -- Verify that the prefix, dereferenced if need be, is a valid
7089 -- controlling argument in a call to Op. The remaining actuals
7090 -- are checked in the subsequent call to Analyze_One_Call.
7092 ------------------------------
7093 -- Collect_Generic_Type_Ops --
7094 ------------------------------
7096 function Collect_Generic_Type_Ops (T : Entity_Id) return Elist_Id is
7097 Bas : constant Entity_Id := Base_Type (T);
7098 Candidates : constant Elist_Id := New_Elmt_List;
7102 procedure Check_Candidate;
7103 -- The operation is a candidate if its first parameter is a
7104 -- controlling operand of the desired type.
7106 -----------------------
7107 -- Check_Candidate; --
7108 -----------------------
7110 procedure Check_Candidate is
7112 Formal := First_Formal (Subp);
7115 and then Is_Controlling_Formal (Formal)
7117 (Base_Type (Etype (Formal)) = Bas
7119 (Is_Access_Type (Etype (Formal))
7120 and then Designated_Type (Etype (Formal)) = Bas))
7122 Append_Elmt (Subp, Candidates);
7124 end Check_Candidate;
7126 -- Start of processing for Collect_Generic_Type_Ops
7129 if Is_Derived_Type (T) then
7130 return Primitive_Operations (T);
7132 elsif Ekind_In (Scope (T), E_Procedure, E_Function) then
7134 -- Scan the list of generic formals to find subprograms
7135 -- that may have a first controlling formal of the type.
7137 if Nkind (Unit_Declaration_Node (Scope (T)))
7138 = N_Generic_Subprogram_Declaration
7145 First (Generic_Formal_Declarations
7146 (Unit_Declaration_Node (Scope (T))));
7147 while Present (Decl) loop
7148 if Nkind (Decl) in N_Formal_Subprogram_Declaration then
7149 Subp := Defining_Entity (Decl);
7160 -- Scan the list of entities declared in the same scope as
7161 -- the type. In general this will be an open scope, given that
7162 -- the call we are analyzing can only appear within a generic
7163 -- declaration or body (either the one that declares T, or a
7166 -- For a subtype representing a generic actual type, go to the
7169 if Is_Generic_Actual_Type (T) then
7170 Subp := First_Entity (Scope (Base_Type (T)));
7172 Subp := First_Entity (Scope (T));
7175 while Present (Subp) loop
7176 if Is_Overloadable (Subp) then
7185 end Collect_Generic_Type_Ops;
7187 ---------------------------
7188 -- Is_Private_Overriding --
7189 ---------------------------
7191 function Is_Private_Overriding (Op : Entity_Id) return Boolean is
7192 Visible_Op : constant Entity_Id := Homonym (Op);
7195 return Present (Visible_Op)
7196 and then Scope (Op) = Scope (Visible_Op)
7197 and then not Comes_From_Source (Visible_Op)
7198 and then Alias (Visible_Op) = Op
7199 and then not Is_Hidden (Visible_Op);
7200 end Is_Private_Overriding;
7202 -----------------------------
7203 -- Valid_First_Argument_Of --
7204 -----------------------------
7206 function Valid_First_Argument_Of (Op : Entity_Id) return Boolean is
7207 Typ : Entity_Id := Etype (First_Formal (Op));
7210 if Is_Concurrent_Type (Typ)
7211 and then Present (Corresponding_Record_Type (Typ))
7213 Typ := Corresponding_Record_Type (Typ);
7216 -- Simple case. Object may be a subtype of the tagged type or
7217 -- may be the corresponding record of a synchronized type.
7219 return Obj_Type = Typ
7220 or else Base_Type (Obj_Type) = Typ
7221 or else Corr_Type = Typ
7223 -- Prefix can be dereferenced
7226 (Is_Access_Type (Corr_Type)
7227 and then Designated_Type (Corr_Type) = Typ)
7229 -- Formal is an access parameter, for which the object
7230 -- can provide an access.
7233 (Ekind (Typ) = E_Anonymous_Access_Type
7234 and then Designated_Type (Typ) = Base_Type (Corr_Type));
7235 end Valid_First_Argument_Of;
7237 -- Start of processing for Try_Primitive_Operation
7240 -- Look for subprograms in the list of primitive operations. The name
7241 -- must be identical, and the kind of call indicates the expected
7242 -- kind of operation (function or procedure). If the type is a
7243 -- (tagged) synchronized type, the primitive ops are attached to the
7244 -- corresponding record (base) type.
7246 if Is_Concurrent_Type (Obj_Type) then
7247 if Present (Corresponding_Record_Type (Obj_Type)) then
7248 Corr_Type := Base_Type (Corresponding_Record_Type (Obj_Type));
7249 Elmt := First_Elmt (Primitive_Operations (Corr_Type));
7251 Corr_Type := Obj_Type;
7252 Elmt := First_Elmt (Collect_Generic_Type_Ops (Obj_Type));
7255 elsif not Is_Generic_Type (Obj_Type) then
7256 Corr_Type := Obj_Type;
7257 Elmt := First_Elmt (Primitive_Operations (Obj_Type));
7260 Corr_Type := Obj_Type;
7261 Elmt := First_Elmt (Collect_Generic_Type_Ops (Obj_Type));
7264 while Present (Elmt) loop
7265 Prim_Op := Node (Elmt);
7267 if Chars (Prim_Op) = Chars (Subprog)
7268 and then Present (First_Formal (Prim_Op))
7269 and then Valid_First_Argument_Of (Prim_Op)
7271 (Nkind (Call_Node) = N_Function_Call)
7272 = (Ekind (Prim_Op) = E_Function)
7274 -- Ada 2005 (AI-251): If this primitive operation corresponds
7275 -- with an immediate ancestor interface there is no need to add
7276 -- it to the list of interpretations; the corresponding aliased
7277 -- primitive is also in this list of primitive operations and
7278 -- will be used instead.
7280 if (Present (Interface_Alias (Prim_Op))
7281 and then Is_Ancestor (Find_Dispatching_Type
7282 (Alias (Prim_Op)), Corr_Type))
7284 -- Do not consider hidden primitives unless the type is in an
7285 -- open scope or we are within an instance, where visibility
7286 -- is known to be correct, or else if this is an overriding
7287 -- operation in the private part for an inherited operation.
7289 or else (Is_Hidden (Prim_Op)
7290 and then not Is_Immediately_Visible (Obj_Type)
7291 and then not In_Instance
7292 and then not Is_Private_Overriding (Prim_Op))
7297 Set_Etype (Call_Node, Any_Type);
7298 Set_Is_Overloaded (Call_Node, False);
7300 if No (Matching_Op) then
7301 Prim_Op_Ref := New_Reference_To (Prim_Op, Sloc (Subprog));
7302 Candidate := Prim_Op;
7304 Set_Parent (Call_Node, Parent (Node_To_Replace));
7306 Set_Name (Call_Node, Prim_Op_Ref);
7312 Report => Report_Error,
7314 Skip_First => True);
7316 Matching_Op := Valid_Candidate (Success, Call_Node, Prim_Op);
7318 -- More than one interpretation, collect for subsequent
7319 -- disambiguation. If this is a procedure call and there
7320 -- is another match, report ambiguity now.
7326 Report => Report_Error,
7328 Skip_First => True);
7330 if Present (Valid_Candidate (Success, Call_Node, Prim_Op))
7331 and then Nkind (Call_Node) /= N_Function_Call
7333 Error_Msg_NE ("ambiguous call to&", N, Prim_Op);
7334 Report_Ambiguity (Matching_Op);
7335 Report_Ambiguity (Prim_Op);
7345 if Present (Matching_Op) then
7346 Set_Etype (Call_Node, Etype (Matching_Op));
7349 return Present (Matching_Op);
7350 end Try_Primitive_Operation;
7352 -- Start of processing for Try_Object_Operation
7355 Analyze_Expression (Obj);
7357 -- Analyze the actuals if node is known to be a subprogram call
7359 if Is_Subprg_Call and then N = Name (Parent (N)) then
7360 Actual := First (Parameter_Associations (Parent (N)));
7361 while Present (Actual) loop
7362 Analyze_Expression (Actual);
7367 -- Build a subprogram call node, using a copy of Obj as its first
7368 -- actual. This is a placeholder, to be replaced by an explicit
7369 -- dereference when needed.
7371 Transform_Object_Operation
7372 (Call_Node => New_Call_Node,
7373 Node_To_Replace => Node_To_Replace);
7375 Set_Etype (New_Call_Node, Any_Type);
7376 Set_Etype (Subprog, Any_Type);
7377 Set_Parent (New_Call_Node, Parent (Node_To_Replace));
7379 if not Is_Overloaded (Obj) then
7380 Try_One_Prefix_Interpretation (Obj_Type);
7387 Get_First_Interp (Obj, I, It);
7388 while Present (It.Nam) loop
7389 Try_One_Prefix_Interpretation (It.Typ);
7390 Get_Next_Interp (I, It);
7395 if Etype (New_Call_Node) /= Any_Type then
7396 Complete_Object_Operation
7397 (Call_Node => New_Call_Node,
7398 Node_To_Replace => Node_To_Replace);
7401 elsif Present (Candidate) then
7403 -- The argument list is not type correct. Re-analyze with error
7404 -- reporting enabled, and use one of the possible candidates.
7405 -- In All_Errors_Mode, re-analyze all failed interpretations.
7407 if All_Errors_Mode then
7408 Report_Error := True;
7409 if Try_Primitive_Operation
7410 (Call_Node => New_Call_Node,
7411 Node_To_Replace => Node_To_Replace)
7414 Try_Class_Wide_Operation
7415 (Call_Node => New_Call_Node,
7416 Node_To_Replace => Node_To_Replace)
7423 (N => New_Call_Node,
7427 Skip_First => True);
7430 -- No need for further errors
7435 -- There was no candidate operation, so report it as an error
7436 -- in the caller: Analyze_Selected_Component.
7440 end Try_Object_Operation;
7446 procedure wpo (T : Entity_Id) is
7451 if not Is_Tagged_Type (T) then
7455 E := First_Elmt (Primitive_Operations (Base_Type (T)));
7456 while Present (E) loop
7458 Write_Int (Int (Op));
7459 Write_Str (" === ");
7460 Write_Name (Chars (Op));
7462 Write_Name (Chars (Scope (Op)));