1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2012, 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 Aspects; use Aspects;
27 with Atree; use Atree;
28 with Debug; use Debug;
29 with Einfo; use Einfo;
30 with Elists; use Elists;
31 with Errout; use Errout;
32 with Exp_Util; use Exp_Util;
33 with Fname; use Fname;
34 with Itypes; use Itypes;
36 with Lib.Xref; use Lib.Xref;
37 with Namet; use Namet;
38 with Namet.Sp; use Namet.Sp;
39 with Nlists; use Nlists;
40 with Nmake; use Nmake;
42 with Output; use Output;
43 with Restrict; use Restrict;
44 with Rident; use Rident;
46 with Sem_Aux; use Sem_Aux;
47 with Sem_Case; use Sem_Case;
48 with Sem_Cat; use Sem_Cat;
49 with Sem_Ch3; use Sem_Ch3;
50 with Sem_Ch5; use Sem_Ch5;
51 with Sem_Ch6; use Sem_Ch6;
52 with Sem_Ch8; use Sem_Ch8;
53 with Sem_Dim; use Sem_Dim;
54 with Sem_Disp; use Sem_Disp;
55 with Sem_Dist; use Sem_Dist;
56 with Sem_Eval; use Sem_Eval;
57 with Sem_Res; use Sem_Res;
58 with Sem_Type; use Sem_Type;
59 with Sem_Util; use Sem_Util;
60 with Sem_Warn; use Sem_Warn;
61 with Stand; use Stand;
62 with Sinfo; use Sinfo;
63 with Snames; use Snames;
64 with Tbuild; use Tbuild;
65 with Uintp; use Uintp;
67 package body Sem_Ch4 is
69 -----------------------
70 -- Local Subprograms --
71 -----------------------
73 procedure Analyze_Concatenation_Rest (N : Node_Id);
74 -- Does the "rest" of the work of Analyze_Concatenation, after the left
75 -- operand has been analyzed. See Analyze_Concatenation for details.
77 procedure Analyze_Expression (N : Node_Id);
78 -- For expressions that are not names, this is just a call to analyze.
79 -- If the expression is a name, it may be a call to a parameterless
80 -- function, and if so must be converted into an explicit call node
81 -- and analyzed as such. This deproceduring must be done during the first
82 -- pass of overload resolution, because otherwise a procedure call with
83 -- overloaded actuals may fail to resolve.
85 procedure Analyze_Operator_Call (N : Node_Id; Op_Id : Entity_Id);
86 -- Analyze a call of the form "+"(x, y), etc. The prefix of the call
87 -- is an operator name or an expanded name whose selector is an operator
88 -- name, and one possible interpretation is as a predefined operator.
90 procedure Analyze_Overloaded_Selected_Component (N : Node_Id);
91 -- If the prefix of a selected_component is overloaded, the proper
92 -- interpretation that yields a record type with the proper selector
93 -- name must be selected.
95 procedure Analyze_User_Defined_Binary_Op (N : Node_Id; Op_Id : Entity_Id);
96 -- Procedure to analyze a user defined binary operator, which is resolved
97 -- like a function, but instead of a list of actuals it is presented
98 -- with the left and right operands of an operator node.
100 procedure Analyze_User_Defined_Unary_Op (N : Node_Id; Op_Id : Entity_Id);
101 -- Procedure to analyze a user defined unary operator, which is resolved
102 -- like a function, but instead of a list of actuals, it is presented with
103 -- the operand of the operator node.
105 procedure Ambiguous_Operands (N : Node_Id);
106 -- For equality, membership, and comparison operators with overloaded
107 -- arguments, list possible interpretations.
109 procedure Analyze_One_Call
113 Success : out Boolean;
114 Skip_First : Boolean := False);
115 -- Check one interpretation of an overloaded subprogram name for
116 -- compatibility with the types of the actuals in a call. If there is a
117 -- single interpretation which does not match, post error if Report is
120 -- Nam is the entity that provides the formals against which the actuals
121 -- are checked. Nam is either the name of a subprogram, or the internal
122 -- subprogram type constructed for an access_to_subprogram. If the actuals
123 -- are compatible with Nam, then Nam is added to the list of candidate
124 -- interpretations for N, and Success is set to True.
126 -- The flag Skip_First is used when analyzing a call that was rewritten
127 -- from object notation. In this case the first actual may have to receive
128 -- an explicit dereference, depending on the first formal of the operation
129 -- being called. The caller will have verified that the object is legal
130 -- for the call. If the remaining parameters match, the first parameter
131 -- will rewritten as a dereference if needed, prior to completing analysis.
133 procedure Check_Misspelled_Selector
136 -- Give possible misspelling diagnostic if Sel is likely to be a mis-
137 -- spelling of one of the selectors of the Prefix. This is called by
138 -- Analyze_Selected_Component after producing an invalid selector error
141 function Defined_In_Scope (T : Entity_Id; S : Entity_Id) return Boolean;
142 -- Verify that type T is declared in scope S. Used to find interpretations
143 -- for operators given by expanded names. This is abstracted as a separate
144 -- function to handle extensions to System, where S is System, but T is
145 -- declared in the extension.
147 procedure Find_Arithmetic_Types
151 -- L and R are the operands of an arithmetic operator. Find
152 -- consistent pairs of interpretations for L and R that have a
153 -- numeric type consistent with the semantics of the operator.
155 procedure Find_Comparison_Types
159 -- L and R are operands of a comparison operator. Find consistent
160 -- pairs of interpretations for L and R.
162 procedure Find_Concatenation_Types
166 -- For the four varieties of concatenation
168 procedure Find_Equality_Types
172 -- Ditto for equality operators
174 procedure Find_Boolean_Types
178 -- Ditto for binary logical operations
180 procedure Find_Negation_Types
184 -- Find consistent interpretation for operand of negation operator
186 procedure Find_Non_Universal_Interpretations
191 -- For equality and comparison operators, the result is always boolean,
192 -- and the legality of the operation is determined from the visibility
193 -- of the operand types. If one of the operands has a universal interpre-
194 -- tation, the legality check uses some compatible non-universal
195 -- interpretation of the other operand. N can be an operator node, or
196 -- a function call whose name is an operator designator.
198 function Find_Primitive_Operation (N : Node_Id) return Boolean;
199 -- Find candidate interpretations for the name Obj.Proc when it appears
200 -- in a subprogram renaming declaration.
202 procedure Find_Unary_Types
206 -- Unary arithmetic types: plus, minus, abs
208 procedure Check_Arithmetic_Pair
212 -- Subsidiary procedure to Find_Arithmetic_Types. T1 and T2 are valid
213 -- types for left and right operand. Determine whether they constitute
214 -- a valid pair for the given operator, and record the corresponding
215 -- interpretation of the operator node. The node N may be an operator
216 -- node (the usual case) or a function call whose prefix is an operator
217 -- designator. In both cases Op_Id is the operator name itself.
219 procedure Diagnose_Call (N : Node_Id; Nam : Node_Id);
220 -- Give detailed information on overloaded call where none of the
221 -- interpretations match. N is the call node, Nam the designator for
222 -- the overloaded entity being called.
224 function Junk_Operand (N : Node_Id) return Boolean;
225 -- Test for an operand that is an inappropriate entity (e.g. a package
226 -- name or a label). If so, issue an error message and return True. If
227 -- the operand is not an inappropriate entity kind, return False.
229 procedure Operator_Check (N : Node_Id);
230 -- Verify that an operator has received some valid interpretation. If none
231 -- was found, determine whether a use clause would make the operation
232 -- legal. The variable Candidate_Type (defined in Sem_Type) is set for
233 -- every type compatible with the operator, even if the operator for the
234 -- type is not directly visible. The routine uses this type to emit a more
235 -- informative message.
237 function Process_Implicit_Dereference_Prefix
239 P : Node_Id) return Entity_Id;
240 -- Called when P is the prefix of an implicit dereference, denoting an
241 -- object E. The function returns the designated type of the prefix, taking
242 -- into account that the designated type of an anonymous access type may be
243 -- a limited view, when the non-limited view is visible.
244 -- If in semantics only mode (-gnatc or generic), the function also records
245 -- that the prefix is a reference to E, if any. Normally, such a reference
246 -- is generated only when the implicit dereference is expanded into an
247 -- explicit one, but for consistency we must generate the reference when
248 -- expansion is disabled as well.
250 procedure Remove_Abstract_Operations (N : Node_Id);
251 -- Ada 2005: implementation of AI-310. An abstract non-dispatching
252 -- operation is not a candidate interpretation.
254 function Try_Container_Indexing
257 Expr : Node_Id) return Boolean;
258 -- AI05-0139: Generalized indexing to support iterators over containers
260 function Try_Indexed_Call
264 Skip_First : Boolean) return Boolean;
265 -- If a function has defaults for all its actuals, a call to it may in fact
266 -- be an indexing on the result of the call. Try_Indexed_Call attempts the
267 -- interpretation as an indexing, prior to analysis as a call. If both are
268 -- possible, the node is overloaded with both interpretations (same symbol
269 -- but two different types). If the call is written in prefix form, the
270 -- prefix becomes the first parameter in the call, and only the remaining
271 -- actuals must be checked for the presence of defaults.
273 function Try_Indirect_Call
276 Typ : Entity_Id) return Boolean;
277 -- Similarly, a function F that needs no actuals can return an access to a
278 -- subprogram, and the call F (X) interpreted as F.all (X). In this case
279 -- the call may be overloaded with both interpretations.
281 function Try_Object_Operation
283 CW_Test_Only : Boolean := False) return Boolean;
284 -- Ada 2005 (AI-252): Support the object.operation notation. If node N
285 -- is a call in this notation, it is transformed into a normal subprogram
286 -- call where the prefix is a parameter, and True is returned. If node
287 -- N is not of this form, it is unchanged, and False is returned. if
288 -- CW_Test_Only is true then N is an N_Selected_Component node which
289 -- is part of a call to an entry or procedure of a tagged concurrent
290 -- type and this routine is invoked to search for class-wide subprograms
291 -- conflicting with the target entity.
293 procedure wpo (T : Entity_Id);
294 pragma Warnings (Off, wpo);
295 -- Used for debugging: obtain list of primitive operations even if
296 -- type is not frozen and dispatch table is not built yet.
298 ------------------------
299 -- Ambiguous_Operands --
300 ------------------------
302 procedure Ambiguous_Operands (N : Node_Id) is
303 procedure List_Operand_Interps (Opnd : Node_Id);
305 --------------------------
306 -- List_Operand_Interps --
307 --------------------------
309 procedure List_Operand_Interps (Opnd : Node_Id) is
314 if Is_Overloaded (Opnd) then
315 if Nkind (Opnd) in N_Op then
317 elsif Nkind (Opnd) = N_Function_Call then
319 elsif Ada_Version >= Ada_2012 then
325 Get_First_Interp (Opnd, I, It);
326 while Present (It.Nam) loop
327 if Has_Implicit_Dereference (It.Typ) then
329 ("can be interpreted as implicit dereference", Opnd);
333 Get_Next_Interp (I, It);
344 if Opnd = Left_Opnd (N) then
345 Error_Msg_N ("\left operand has the following interpretations", N);
348 ("\right operand has the following interpretations", N);
352 List_Interps (Nam, Err);
353 end List_Operand_Interps;
355 -- Start of processing for Ambiguous_Operands
358 if Nkind (N) in N_Membership_Test then
359 Error_Msg_N ("ambiguous operands for membership", N);
361 elsif Nkind_In (N, N_Op_Eq, N_Op_Ne) then
362 Error_Msg_N ("ambiguous operands for equality", N);
365 Error_Msg_N ("ambiguous operands for comparison", N);
368 if All_Errors_Mode then
369 List_Operand_Interps (Left_Opnd (N));
370 List_Operand_Interps (Right_Opnd (N));
372 Error_Msg_N ("\use -gnatf switch for details", N);
374 end Ambiguous_Operands;
376 -----------------------
377 -- Analyze_Aggregate --
378 -----------------------
380 -- Most of the analysis of Aggregates requires that the type be known,
381 -- and is therefore put off until resolution.
383 procedure Analyze_Aggregate (N : Node_Id) is
385 if No (Etype (N)) then
386 Set_Etype (N, Any_Composite);
388 end Analyze_Aggregate;
390 -----------------------
391 -- Analyze_Allocator --
392 -----------------------
394 procedure Analyze_Allocator (N : Node_Id) is
395 Loc : constant Source_Ptr := Sloc (N);
396 Sav_Errs : constant Nat := Serious_Errors_Detected;
397 E : Node_Id := Expression (N);
398 Acc_Type : Entity_Id;
404 Check_SPARK_Restriction ("allocator is not allowed", N);
406 -- Deal with allocator restrictions
408 -- In accordance with H.4(7), the No_Allocators restriction only applies
409 -- to user-written allocators. The same consideration applies to the
410 -- No_Allocators_Before_Elaboration restriction.
412 if Comes_From_Source (N) then
413 Check_Restriction (No_Allocators, N);
415 -- Processing for No_Allocators_After_Elaboration, loop to look at
416 -- enclosing context, checking task case and main subprogram case.
420 while Present (P) loop
422 -- In both cases we need a handled sequence of statements, where
423 -- the occurrence of the allocator is within the statements.
425 if Nkind (P) = N_Handled_Sequence_Of_Statements
426 and then Is_List_Member (C)
427 and then List_Containing (C) = Statements (P)
429 -- Check for allocator within task body, this is a definite
430 -- violation of No_Allocators_After_Elaboration we can detect.
432 if Nkind (Original_Node (Parent (P))) = N_Task_Body then
433 Check_Restriction (No_Allocators_After_Elaboration, N);
437 -- The other case is appearance in a subprogram body. This may
438 -- be a violation if this is a library level subprogram, and it
439 -- turns out to be used as the main program, but only the
440 -- binder knows that, so just record the occurrence.
442 if Nkind (Original_Node (Parent (P))) = N_Subprogram_Body
443 and then Nkind (Parent (Parent (P))) = N_Compilation_Unit
445 Set_Has_Allocator (Current_Sem_Unit);
454 -- Ada 2012 (AI05-0111-3): Analyze the subpool_specification, if
455 -- any. The expected type for the name is any type. A non-overloading
456 -- rule then requires it to be of a type descended from
457 -- System.Storage_Pools.Subpools.Subpool_Handle.
459 -- This isn't exactly what the AI says, but it seems to be the right
460 -- rule. The AI should be fixed.???
463 Subpool : constant Node_Id := Subpool_Handle_Name (N);
466 if Present (Subpool) then
469 if Is_Overloaded (Subpool) then
470 Error_Msg_N ("ambiguous subpool handle", Subpool);
473 -- Check that Etype (Subpool) is descended from Subpool_Handle
479 -- Analyze the qualified expression or subtype indication
481 if Nkind (E) = N_Qualified_Expression then
482 Acc_Type := Create_Itype (E_Allocator_Type, N);
483 Set_Etype (Acc_Type, Acc_Type);
484 Find_Type (Subtype_Mark (E));
486 -- Analyze the qualified expression, and apply the name resolution
487 -- rule given in 4.7(3).
490 Type_Id := Etype (E);
491 Set_Directly_Designated_Type (Acc_Type, Type_Id);
493 Resolve (Expression (E), Type_Id);
495 -- Allocators generated by the build-in-place expansion mechanism
496 -- are explicitly marked as coming from source but do not need to be
497 -- checked for limited initialization. To exclude this case, ensure
498 -- that the parent of the allocator is a source node.
500 if Is_Limited_Type (Type_Id)
501 and then Comes_From_Source (N)
502 and then Comes_From_Source (Parent (N))
503 and then not In_Instance_Body
505 if not OK_For_Limited_Init (Type_Id, Expression (E)) then
506 Error_Msg_N ("initialization not allowed for limited types", N);
507 Explain_Limited_Type (Type_Id, N);
511 -- A qualified expression requires an exact match of the type,
512 -- class-wide matching is not allowed.
514 -- if Is_Class_Wide_Type (Type_Id)
515 -- and then Base_Type
516 -- (Etype (Expression (E))) /= Base_Type (Type_Id)
518 -- Wrong_Type (Expression (E), Type_Id);
521 Check_Non_Static_Context (Expression (E));
523 -- We don't analyze the qualified expression itself because it's
524 -- part of the allocator
526 Set_Etype (E, Type_Id);
528 -- Case where allocator has a subtype indication
533 Base_Typ : Entity_Id;
536 -- If the allocator includes a N_Subtype_Indication then a
537 -- constraint is present, otherwise the node is a subtype mark.
538 -- Introduce an explicit subtype declaration into the tree
539 -- defining some anonymous subtype and rewrite the allocator to
540 -- use this subtype rather than the subtype indication.
542 -- It is important to introduce the explicit subtype declaration
543 -- so that the bounds of the subtype indication are attached to
544 -- the tree in case the allocator is inside a generic unit.
546 if Nkind (E) = N_Subtype_Indication then
548 -- A constraint is only allowed for a composite type in Ada
549 -- 95. In Ada 83, a constraint is also allowed for an
550 -- access-to-composite type, but the constraint is ignored.
552 Find_Type (Subtype_Mark (E));
553 Base_Typ := Entity (Subtype_Mark (E));
555 if Is_Elementary_Type (Base_Typ) then
556 if not (Ada_Version = Ada_83
557 and then Is_Access_Type (Base_Typ))
559 Error_Msg_N ("constraint not allowed here", E);
561 if Nkind (Constraint (E)) =
562 N_Index_Or_Discriminant_Constraint
564 Error_Msg_N -- CODEFIX
565 ("\if qualified expression was meant, " &
566 "use apostrophe", Constraint (E));
570 -- Get rid of the bogus constraint:
572 Rewrite (E, New_Copy_Tree (Subtype_Mark (E)));
573 Analyze_Allocator (N);
576 -- Ada 2005, AI-363: if the designated type has a constrained
577 -- partial view, it cannot receive a discriminant constraint,
578 -- and the allocated object is unconstrained.
580 elsif Ada_Version >= Ada_2005
581 and then Effectively_Has_Constrained_Partial_View
583 Scop => Current_Scope)
586 ("constraint not allowed when type " &
587 "has a constrained partial view", Constraint (E));
590 if Expander_Active then
591 Def_Id := Make_Temporary (Loc, 'S');
594 Make_Subtype_Declaration (Loc,
595 Defining_Identifier => Def_Id,
596 Subtype_Indication => Relocate_Node (E)));
598 if Sav_Errs /= Serious_Errors_Detected
599 and then Nkind (Constraint (E)) =
600 N_Index_Or_Discriminant_Constraint
602 Error_Msg_N -- CODEFIX
603 ("if qualified expression was meant, " &
604 "use apostrophe!", Constraint (E));
607 E := New_Occurrence_Of (Def_Id, Loc);
608 Rewrite (Expression (N), E);
612 Type_Id := Process_Subtype (E, N);
613 Acc_Type := Create_Itype (E_Allocator_Type, N);
614 Set_Etype (Acc_Type, Acc_Type);
615 Set_Directly_Designated_Type (Acc_Type, Type_Id);
616 Check_Fully_Declared (Type_Id, N);
618 -- Ada 2005 (AI-231): If the designated type is itself an access
619 -- type that excludes null, its default initialization will
620 -- be a null object, and we can insert an unconditional raise
621 -- before the allocator.
623 -- Ada 2012 (AI-104): A not null indication here is altogether
626 if Can_Never_Be_Null (Type_Id) then
628 Not_Null_Check : constant Node_Id :=
629 Make_Raise_Constraint_Error (Sloc (E),
630 Reason => CE_Null_Not_Allowed);
633 if Ada_Version >= Ada_2012 then
635 ("an uninitialized allocator cannot have"
636 & " a null exclusion", N);
638 elsif Expander_Active then
639 Insert_Action (N, Not_Null_Check);
640 Analyze (Not_Null_Check);
643 Error_Msg_N ("null value not allowed here?", E);
648 -- Check restriction against dynamically allocated protected
649 -- objects. Note that when limited aggregates are supported,
650 -- a similar test should be applied to an allocator with a
651 -- qualified expression ???
653 if Is_Protected_Type (Type_Id) then
654 Check_Restriction (No_Protected_Type_Allocators, N);
657 -- Check for missing initialization. Skip this check if we already
658 -- had errors on analyzing the allocator, since in that case these
659 -- are probably cascaded errors.
661 if Is_Indefinite_Subtype (Type_Id)
662 and then Serious_Errors_Detected = Sav_Errs
664 if Is_Class_Wide_Type (Type_Id) then
666 ("initialization required in class-wide allocation", N);
668 if Ada_Version < Ada_2005
669 and then Is_Limited_Type (Type_Id)
671 Error_Msg_N ("unconstrained allocation not allowed", N);
673 if Is_Array_Type (Type_Id) then
675 ("\constraint with array bounds required", N);
677 elsif Has_Unknown_Discriminants (Type_Id) then
680 else pragma Assert (Has_Discriminants (Type_Id));
682 ("\constraint with discriminant values required", N);
685 -- Limited Ada 2005 and general non-limited case
689 ("uninitialized unconstrained allocation not allowed",
692 if Is_Array_Type (Type_Id) then
694 ("\qualified expression or constraint with " &
695 "array bounds required", N);
697 elsif Has_Unknown_Discriminants (Type_Id) then
698 Error_Msg_N ("\qualified expression required", N);
700 else pragma Assert (Has_Discriminants (Type_Id));
702 ("\qualified expression or constraint with " &
703 "discriminant values required", N);
711 if Is_Abstract_Type (Type_Id) then
712 Error_Msg_N ("cannot allocate abstract object", E);
715 if Has_Task (Designated_Type (Acc_Type)) then
716 Check_Restriction (No_Tasking, N);
717 Check_Restriction (Max_Tasks, N);
718 Check_Restriction (No_Task_Allocators, N);
721 -- AI05-0013-1: No_Nested_Finalization forbids allocators if the access
722 -- type is nested, and the designated type needs finalization. The rule
723 -- is conservative in that class-wide types need finalization.
725 if Needs_Finalization (Designated_Type (Acc_Type))
726 and then not Is_Library_Level_Entity (Acc_Type)
728 Check_Restriction (No_Nested_Finalization, N);
731 -- Check that an allocator of a nested access type doesn't create a
732 -- protected object when restriction No_Local_Protected_Objects applies.
733 -- We don't have an equivalent to Has_Task for protected types, so only
734 -- cases where the designated type itself is a protected type are
735 -- currently checked. ???
737 if Is_Protected_Type (Designated_Type (Acc_Type))
738 and then not Is_Library_Level_Entity (Acc_Type)
740 Check_Restriction (No_Local_Protected_Objects, N);
743 -- If the No_Streams restriction is set, check that the type of the
744 -- object is not, and does not contain, any subtype derived from
745 -- Ada.Streams.Root_Stream_Type. Note that we guard the call to
746 -- Has_Stream just for efficiency reasons. There is no point in
747 -- spending time on a Has_Stream check if the restriction is not set.
749 if Restriction_Check_Required (No_Streams) then
750 if Has_Stream (Designated_Type (Acc_Type)) then
751 Check_Restriction (No_Streams, N);
755 Set_Etype (N, Acc_Type);
757 if not Is_Library_Level_Entity (Acc_Type) then
758 Check_Restriction (No_Local_Allocators, N);
761 if Serious_Errors_Detected > Sav_Errs then
762 Set_Error_Posted (N);
763 Set_Etype (N, Any_Type);
765 end Analyze_Allocator;
767 ---------------------------
768 -- Analyze_Arithmetic_Op --
769 ---------------------------
771 procedure Analyze_Arithmetic_Op (N : Node_Id) is
772 L : constant Node_Id := Left_Opnd (N);
773 R : constant Node_Id := Right_Opnd (N);
777 Candidate_Type := Empty;
778 Analyze_Expression (L);
779 Analyze_Expression (R);
781 -- If the entity is already set, the node is the instantiation of a
782 -- generic node with a non-local reference, or was manufactured by a
783 -- call to Make_Op_xxx. In either case the entity is known to be valid,
784 -- and we do not need to collect interpretations, instead we just get
785 -- the single possible interpretation.
789 if Present (Op_Id) then
790 if Ekind (Op_Id) = E_Operator then
792 if Nkind_In (N, N_Op_Divide, N_Op_Mod, N_Op_Multiply, N_Op_Rem)
793 and then Treat_Fixed_As_Integer (N)
797 Set_Etype (N, Any_Type);
798 Find_Arithmetic_Types (L, R, Op_Id, N);
802 Set_Etype (N, Any_Type);
803 Add_One_Interp (N, Op_Id, Etype (Op_Id));
806 -- Entity is not already set, so we do need to collect interpretations
809 Op_Id := Get_Name_Entity_Id (Chars (N));
810 Set_Etype (N, Any_Type);
812 while Present (Op_Id) loop
813 if Ekind (Op_Id) = E_Operator
814 and then Present (Next_Entity (First_Entity (Op_Id)))
816 Find_Arithmetic_Types (L, R, Op_Id, N);
818 -- The following may seem superfluous, because an operator cannot
819 -- be generic, but this ignores the cleverness of the author of
822 elsif Is_Overloadable (Op_Id) then
823 Analyze_User_Defined_Binary_Op (N, Op_Id);
826 Op_Id := Homonym (Op_Id);
831 end Analyze_Arithmetic_Op;
837 -- Function, procedure, and entry calls are checked here. The Name in
838 -- the call may be overloaded. The actuals have been analyzed and may
839 -- themselves be overloaded. On exit from this procedure, the node N
840 -- may have zero, one or more interpretations. In the first case an
841 -- error message is produced. In the last case, the node is flagged
842 -- as overloaded and the interpretations are collected in All_Interp.
844 -- If the name is an Access_To_Subprogram, it cannot be overloaded, but
845 -- the type-checking is similar to that of other calls.
847 procedure Analyze_Call (N : Node_Id) is
848 Actuals : constant List_Id := Parameter_Associations (N);
853 Success : Boolean := False;
855 Deref : Boolean := False;
856 -- Flag indicates whether an interpretation of the prefix is a
857 -- parameterless call that returns an access_to_subprogram.
859 procedure Check_Mixed_Parameter_And_Named_Associations;
860 -- Check that parameter and named associations are not mixed. This is
861 -- a restriction in SPARK mode.
863 function Name_Denotes_Function return Boolean;
864 -- If the type of the name is an access to subprogram, this may be the
865 -- type of a name, or the return type of the function being called. If
866 -- the name is not an entity then it can denote a protected function.
867 -- Until we distinguish Etype from Return_Type, we must use this routine
868 -- to resolve the meaning of the name in the call.
870 procedure No_Interpretation;
871 -- Output error message when no valid interpretation exists
873 --------------------------------------------------
874 -- Check_Mixed_Parameter_And_Named_Associations --
875 --------------------------------------------------
877 procedure Check_Mixed_Parameter_And_Named_Associations is
879 Named_Seen : Boolean;
884 Actual := First (Actuals);
885 while Present (Actual) loop
886 case Nkind (Actual) is
887 when N_Parameter_Association =>
889 Check_SPARK_Restriction
890 ("named association cannot follow positional one",
900 end Check_Mixed_Parameter_And_Named_Associations;
902 ---------------------------
903 -- Name_Denotes_Function --
904 ---------------------------
906 function Name_Denotes_Function return Boolean is
908 if Is_Entity_Name (Nam) then
909 return Ekind (Entity (Nam)) = E_Function;
911 elsif Nkind (Nam) = N_Selected_Component then
912 return Ekind (Entity (Selector_Name (Nam))) = E_Function;
917 end Name_Denotes_Function;
919 -----------------------
920 -- No_Interpretation --
921 -----------------------
923 procedure No_Interpretation is
924 L : constant Boolean := Is_List_Member (N);
925 K : constant Node_Kind := Nkind (Parent (N));
928 -- If the node is in a list whose parent is not an expression then it
929 -- must be an attempted procedure call.
931 if L and then K not in N_Subexpr then
932 if Ekind (Entity (Nam)) = E_Generic_Procedure then
934 ("must instantiate generic procedure& before call",
938 ("procedure or entry name expected", Nam);
941 -- Check for tasking cases where only an entry call will do
944 and then Nkind_In (K, N_Entry_Call_Alternative,
945 N_Triggering_Alternative)
947 Error_Msg_N ("entry name expected", Nam);
949 -- Otherwise give general error message
952 Error_Msg_N ("invalid prefix in call", Nam);
954 end No_Interpretation;
956 -- Start of processing for Analyze_Call
959 if Restriction_Check_Required (SPARK) then
960 Check_Mixed_Parameter_And_Named_Associations;
963 -- Initialize the type of the result of the call to the error type,
964 -- which will be reset if the type is successfully resolved.
966 Set_Etype (N, Any_Type);
970 if not Is_Overloaded (Nam) then
972 -- Only one interpretation to check
974 if Ekind (Etype (Nam)) = E_Subprogram_Type then
975 Nam_Ent := Etype (Nam);
977 -- If the prefix is an access_to_subprogram, this may be an indirect
978 -- call. This is the case if the name in the call is not an entity
979 -- name, or if it is a function name in the context of a procedure
980 -- call. In this latter case, we have a call to a parameterless
981 -- function that returns a pointer_to_procedure which is the entity
982 -- being called. Finally, F (X) may be a call to a parameterless
983 -- function that returns a pointer to a function with parameters.
985 elsif Is_Access_Type (Etype (Nam))
986 and then Ekind (Designated_Type (Etype (Nam))) = E_Subprogram_Type
988 (not Name_Denotes_Function
989 or else Nkind (N) = N_Procedure_Call_Statement
991 (Nkind (Parent (N)) /= N_Explicit_Dereference
992 and then Is_Entity_Name (Nam)
993 and then No (First_Formal (Entity (Nam)))
994 and then Present (Actuals)))
996 Nam_Ent := Designated_Type (Etype (Nam));
997 Insert_Explicit_Dereference (Nam);
999 -- Selected component case. Simple entry or protected operation,
1000 -- where the entry name is given by the selector name.
1002 elsif Nkind (Nam) = N_Selected_Component then
1003 Nam_Ent := Entity (Selector_Name (Nam));
1005 if not Ekind_In (Nam_Ent, E_Entry,
1010 Error_Msg_N ("name in call is not a callable entity", Nam);
1011 Set_Etype (N, Any_Type);
1015 -- If the name is an Indexed component, it can be a call to a member
1016 -- of an entry family. The prefix must be a selected component whose
1017 -- selector is the entry. Analyze_Procedure_Call normalizes several
1018 -- kinds of call into this form.
1020 elsif Nkind (Nam) = N_Indexed_Component then
1021 if Nkind (Prefix (Nam)) = N_Selected_Component then
1022 Nam_Ent := Entity (Selector_Name (Prefix (Nam)));
1024 Error_Msg_N ("name in call is not a callable entity", Nam);
1025 Set_Etype (N, Any_Type);
1029 elsif not Is_Entity_Name (Nam) then
1030 Error_Msg_N ("name in call is not a callable entity", Nam);
1031 Set_Etype (N, Any_Type);
1035 Nam_Ent := Entity (Nam);
1037 -- If no interpretations, give error message
1039 if not Is_Overloadable (Nam_Ent) then
1045 -- Operations generated for RACW stub types are called only through
1046 -- dispatching, and can never be the static interpretation of a call.
1048 if Is_RACW_Stub_Type_Operation (Nam_Ent) then
1053 Analyze_One_Call (N, Nam_Ent, True, Success);
1055 -- If this is an indirect call, the return type of the access_to
1056 -- subprogram may be an incomplete type. At the point of the call,
1057 -- use the full type if available, and at the same time update the
1058 -- return type of the access_to_subprogram.
1061 and then Nkind (Nam) = N_Explicit_Dereference
1062 and then Ekind (Etype (N)) = E_Incomplete_Type
1063 and then Present (Full_View (Etype (N)))
1065 Set_Etype (N, Full_View (Etype (N)));
1066 Set_Etype (Nam_Ent, Etype (N));
1070 -- An overloaded selected component must denote overloaded operations
1071 -- of a concurrent type. The interpretations are attached to the
1072 -- simple name of those operations.
1074 if Nkind (Nam) = N_Selected_Component then
1075 Nam := Selector_Name (Nam);
1078 Get_First_Interp (Nam, X, It);
1080 while Present (It.Nam) loop
1084 -- Name may be call that returns an access to subprogram, or more
1085 -- generally an overloaded expression one of whose interpretations
1086 -- yields an access to subprogram. If the name is an entity, we do
1087 -- not dereference, because the node is a call that returns the
1088 -- access type: note difference between f(x), where the call may
1089 -- return an access subprogram type, and f(x)(y), where the type
1090 -- returned by the call to f is implicitly dereferenced to analyze
1093 if Is_Access_Type (Nam_Ent) then
1094 Nam_Ent := Designated_Type (Nam_Ent);
1096 elsif Is_Access_Type (Etype (Nam_Ent))
1098 (not Is_Entity_Name (Nam)
1099 or else Nkind (N) = N_Procedure_Call_Statement)
1100 and then Ekind (Designated_Type (Etype (Nam_Ent)))
1103 Nam_Ent := Designated_Type (Etype (Nam_Ent));
1105 if Is_Entity_Name (Nam) then
1110 -- If the call has been rewritten from a prefixed call, the first
1111 -- parameter has been analyzed, but may need a subsequent
1112 -- dereference, so skip its analysis now.
1114 if N /= Original_Node (N)
1115 and then Nkind (Original_Node (N)) = Nkind (N)
1116 and then Nkind (Name (N)) /= Nkind (Name (Original_Node (N)))
1117 and then Present (Parameter_Associations (N))
1118 and then Present (Etype (First (Parameter_Associations (N))))
1121 (N, Nam_Ent, False, Success, Skip_First => True);
1123 Analyze_One_Call (N, Nam_Ent, False, Success);
1126 -- If the interpretation succeeds, mark the proper type of the
1127 -- prefix (any valid candidate will do). If not, remove the
1128 -- candidate interpretation. This only needs to be done for
1129 -- overloaded protected operations, for other entities disambi-
1130 -- guation is done directly in Resolve.
1134 and then Nkind (Parent (N)) /= N_Explicit_Dereference
1136 Set_Entity (Nam, It.Nam);
1137 Insert_Explicit_Dereference (Nam);
1138 Set_Etype (Nam, Nam_Ent);
1141 Set_Etype (Nam, It.Typ);
1144 elsif Nkind_In (Name (N), N_Selected_Component,
1150 Get_Next_Interp (X, It);
1153 -- If the name is the result of a function call, it can only
1154 -- be a call to a function returning an access to subprogram.
1155 -- Insert explicit dereference.
1157 if Nkind (Nam) = N_Function_Call then
1158 Insert_Explicit_Dereference (Nam);
1161 if Etype (N) = Any_Type then
1163 -- None of the interpretations is compatible with the actuals
1165 Diagnose_Call (N, Nam);
1167 -- Special checks for uninstantiated put routines
1169 if Nkind (N) = N_Procedure_Call_Statement
1170 and then Is_Entity_Name (Nam)
1171 and then Chars (Nam) = Name_Put
1172 and then List_Length (Actuals) = 1
1175 Arg : constant Node_Id := First (Actuals);
1179 if Nkind (Arg) = N_Parameter_Association then
1180 Typ := Etype (Explicit_Actual_Parameter (Arg));
1185 if Is_Signed_Integer_Type (Typ) then
1187 ("possible missing instantiation of " &
1188 "'Text_'I'O.'Integer_'I'O!", Nam);
1190 elsif Is_Modular_Integer_Type (Typ) then
1192 ("possible missing instantiation of " &
1193 "'Text_'I'O.'Modular_'I'O!", Nam);
1195 elsif Is_Floating_Point_Type (Typ) then
1197 ("possible missing instantiation of " &
1198 "'Text_'I'O.'Float_'I'O!", Nam);
1200 elsif Is_Ordinary_Fixed_Point_Type (Typ) then
1202 ("possible missing instantiation of " &
1203 "'Text_'I'O.'Fixed_'I'O!", Nam);
1205 elsif Is_Decimal_Fixed_Point_Type (Typ) then
1207 ("possible missing instantiation of " &
1208 "'Text_'I'O.'Decimal_'I'O!", Nam);
1210 elsif Is_Enumeration_Type (Typ) then
1212 ("possible missing instantiation of " &
1213 "'Text_'I'O.'Enumeration_'I'O!", Nam);
1218 elsif not Is_Overloaded (N)
1219 and then Is_Entity_Name (Nam)
1221 -- Resolution yields a single interpretation. Verify that the
1222 -- reference has capitalization consistent with the declaration.
1224 Set_Entity_With_Style_Check (Nam, Entity (Nam));
1225 Generate_Reference (Entity (Nam), Nam);
1227 Set_Etype (Nam, Etype (Entity (Nam)));
1229 Remove_Abstract_Operations (N);
1236 -----------------------------
1237 -- Analyze_Case_Expression --
1238 -----------------------------
1240 procedure Analyze_Case_Expression (N : Node_Id) is
1241 Expr : constant Node_Id := Expression (N);
1242 FirstX : constant Node_Id := Expression (First (Alternatives (N)));
1244 Exp_Type : Entity_Id;
1245 Exp_Btype : Entity_Id;
1247 Dont_Care : Boolean;
1248 Others_Present : Boolean;
1250 procedure Non_Static_Choice_Error (Choice : Node_Id);
1251 -- Error routine invoked by the generic instantiation below when
1252 -- the case expression has a non static choice.
1254 package Case_Choices_Processing is new
1255 Generic_Choices_Processing
1256 (Get_Alternatives => Alternatives,
1257 Get_Choices => Discrete_Choices,
1258 Process_Empty_Choice => No_OP,
1259 Process_Non_Static_Choice => Non_Static_Choice_Error,
1260 Process_Associated_Node => No_OP);
1261 use Case_Choices_Processing;
1263 -----------------------------
1264 -- Non_Static_Choice_Error --
1265 -----------------------------
1267 procedure Non_Static_Choice_Error (Choice : Node_Id) is
1269 Flag_Non_Static_Expr
1270 ("choice given in case expression is not static!", Choice);
1271 end Non_Static_Choice_Error;
1273 -- Start of processing for Analyze_Case_Expression
1276 if Comes_From_Source (N) then
1277 Check_Compiler_Unit (N);
1280 Analyze_And_Resolve (Expr, Any_Discrete);
1281 Check_Unset_Reference (Expr);
1282 Exp_Type := Etype (Expr);
1283 Exp_Btype := Base_Type (Exp_Type);
1285 Alt := First (Alternatives (N));
1286 while Present (Alt) loop
1287 Analyze (Expression (Alt));
1291 if not Is_Overloaded (FirstX) then
1292 Set_Etype (N, Etype (FirstX));
1300 Set_Etype (N, Any_Type);
1302 Get_First_Interp (FirstX, I, It);
1303 while Present (It.Nam) loop
1305 -- For each interpretation of the first expression, we only
1306 -- add the interpretation if every other expression in the
1307 -- case expression alternatives has a compatible type.
1309 Alt := Next (First (Alternatives (N)));
1310 while Present (Alt) loop
1311 exit when not Has_Compatible_Type (Expression (Alt), It.Typ);
1316 Add_One_Interp (N, It.Typ, It.Typ);
1319 Get_Next_Interp (I, It);
1324 Exp_Btype := Base_Type (Exp_Type);
1326 -- The expression must be of a discrete type which must be determinable
1327 -- independently of the context in which the expression occurs, but
1328 -- using the fact that the expression must be of a discrete type.
1329 -- Moreover, the type this expression must not be a character literal
1330 -- (which is always ambiguous).
1332 -- If error already reported by Resolve, nothing more to do
1334 if Exp_Btype = Any_Discrete
1335 or else Exp_Btype = Any_Type
1339 elsif Exp_Btype = Any_Character then
1341 ("character literal as case expression is ambiguous", Expr);
1345 -- If the case expression is a formal object of mode in out, then
1346 -- treat it as having a nonstatic subtype by forcing use of the base
1347 -- type (which has to get passed to Check_Case_Choices below). Also
1348 -- use base type when the case expression is parenthesized.
1350 if Paren_Count (Expr) > 0
1351 or else (Is_Entity_Name (Expr)
1352 and then Ekind (Entity (Expr)) = E_Generic_In_Out_Parameter)
1354 Exp_Type := Exp_Btype;
1357 -- Call instantiated Analyze_Choices which does the rest of the work
1359 Analyze_Choices (N, Exp_Type, Dont_Care, Others_Present);
1361 if Exp_Type = Universal_Integer and then not Others_Present then
1363 ("case on universal integer requires OTHERS choice", Expr);
1365 end Analyze_Case_Expression;
1367 ---------------------------
1368 -- Analyze_Comparison_Op --
1369 ---------------------------
1371 procedure Analyze_Comparison_Op (N : Node_Id) is
1372 L : constant Node_Id := Left_Opnd (N);
1373 R : constant Node_Id := Right_Opnd (N);
1374 Op_Id : Entity_Id := Entity (N);
1377 Set_Etype (N, Any_Type);
1378 Candidate_Type := Empty;
1380 Analyze_Expression (L);
1381 Analyze_Expression (R);
1383 if Present (Op_Id) then
1384 if Ekind (Op_Id) = E_Operator then
1385 Find_Comparison_Types (L, R, Op_Id, N);
1387 Add_One_Interp (N, Op_Id, Etype (Op_Id));
1390 if Is_Overloaded (L) then
1391 Set_Etype (L, Intersect_Types (L, R));
1395 Op_Id := Get_Name_Entity_Id (Chars (N));
1396 while Present (Op_Id) loop
1397 if Ekind (Op_Id) = E_Operator then
1398 Find_Comparison_Types (L, R, Op_Id, N);
1400 Analyze_User_Defined_Binary_Op (N, Op_Id);
1403 Op_Id := Homonym (Op_Id);
1408 end Analyze_Comparison_Op;
1410 ---------------------------
1411 -- Analyze_Concatenation --
1412 ---------------------------
1414 procedure Analyze_Concatenation (N : Node_Id) is
1416 -- We wish to avoid deep recursion, because concatenations are often
1417 -- deeply nested, as in A&B&...&Z. Therefore, we walk down the left
1418 -- operands nonrecursively until we find something that is not a
1419 -- concatenation (A in this case), or has already been analyzed. We
1420 -- analyze that, and then walk back up the tree following Parent
1421 -- pointers, calling Analyze_Concatenation_Rest to do the rest of the
1422 -- work at each level. The Parent pointers allow us to avoid recursion,
1423 -- and thus avoid running out of memory.
1429 Candidate_Type := Empty;
1431 -- The following code is equivalent to:
1433 -- Set_Etype (N, Any_Type);
1434 -- Analyze_Expression (Left_Opnd (N));
1435 -- Analyze_Concatenation_Rest (N);
1437 -- where the Analyze_Expression call recurses back here if the left
1438 -- operand is a concatenation.
1440 -- Walk down left operands
1443 Set_Etype (NN, Any_Type);
1444 L := Left_Opnd (NN);
1445 exit when Nkind (L) /= N_Op_Concat or else Analyzed (L);
1449 -- Now (given the above example) NN is A&B and L is A
1451 -- First analyze L ...
1453 Analyze_Expression (L);
1455 -- ... then walk NN back up until we reach N (where we started), calling
1456 -- Analyze_Concatenation_Rest along the way.
1459 Analyze_Concatenation_Rest (NN);
1463 end Analyze_Concatenation;
1465 --------------------------------
1466 -- Analyze_Concatenation_Rest --
1467 --------------------------------
1469 -- If the only one-dimensional array type in scope is String,
1470 -- this is the resulting type of the operation. Otherwise there
1471 -- will be a concatenation operation defined for each user-defined
1472 -- one-dimensional array.
1474 procedure Analyze_Concatenation_Rest (N : Node_Id) is
1475 L : constant Node_Id := Left_Opnd (N);
1476 R : constant Node_Id := Right_Opnd (N);
1477 Op_Id : Entity_Id := Entity (N);
1482 Analyze_Expression (R);
1484 -- If the entity is present, the node appears in an instance, and
1485 -- denotes a predefined concatenation operation. The resulting type is
1486 -- obtained from the arguments when possible. If the arguments are
1487 -- aggregates, the array type and the concatenation type must be
1490 if Present (Op_Id) then
1491 if Ekind (Op_Id) = E_Operator then
1492 LT := Base_Type (Etype (L));
1493 RT := Base_Type (Etype (R));
1495 if Is_Array_Type (LT)
1496 and then (RT = LT or else RT = Base_Type (Component_Type (LT)))
1498 Add_One_Interp (N, Op_Id, LT);
1500 elsif Is_Array_Type (RT)
1501 and then LT = Base_Type (Component_Type (RT))
1503 Add_One_Interp (N, Op_Id, RT);
1505 -- If one operand is a string type or a user-defined array type,
1506 -- and the other is a literal, result is of the specific type.
1509 (Root_Type (LT) = Standard_String
1510 or else Scope (LT) /= Standard_Standard)
1511 and then Etype (R) = Any_String
1513 Add_One_Interp (N, Op_Id, LT);
1516 (Root_Type (RT) = Standard_String
1517 or else Scope (RT) /= Standard_Standard)
1518 and then Etype (L) = Any_String
1520 Add_One_Interp (N, Op_Id, RT);
1522 elsif not Is_Generic_Type (Etype (Op_Id)) then
1523 Add_One_Interp (N, Op_Id, Etype (Op_Id));
1526 -- Type and its operations must be visible
1528 Set_Entity (N, Empty);
1529 Analyze_Concatenation (N);
1533 Add_One_Interp (N, Op_Id, Etype (Op_Id));
1537 Op_Id := Get_Name_Entity_Id (Name_Op_Concat);
1538 while Present (Op_Id) loop
1539 if Ekind (Op_Id) = E_Operator then
1541 -- Do not consider operators declared in dead code, they can
1542 -- not be part of the resolution.
1544 if Is_Eliminated (Op_Id) then
1547 Find_Concatenation_Types (L, R, Op_Id, N);
1551 Analyze_User_Defined_Binary_Op (N, Op_Id);
1554 Op_Id := Homonym (Op_Id);
1559 end Analyze_Concatenation_Rest;
1561 ------------------------------------
1562 -- Analyze_Conditional_Expression --
1563 ------------------------------------
1565 procedure Analyze_Conditional_Expression (N : Node_Id) is
1566 Condition : constant Node_Id := First (Expressions (N));
1567 Then_Expr : constant Node_Id := Next (Condition);
1568 Else_Expr : Node_Id;
1571 -- Defend against error of missing expressions from previous error
1573 if No (Then_Expr) then
1577 Check_SPARK_Restriction ("conditional expression is not allowed", N);
1579 Else_Expr := Next (Then_Expr);
1581 if Comes_From_Source (N) then
1582 Check_Compiler_Unit (N);
1585 Analyze_Expression (Condition);
1586 Analyze_Expression (Then_Expr);
1588 if Present (Else_Expr) then
1589 Analyze_Expression (Else_Expr);
1592 -- If then expression not overloaded, then that decides the type
1594 if not Is_Overloaded (Then_Expr) then
1595 Set_Etype (N, Etype (Then_Expr));
1597 -- Case where then expression is overloaded
1605 Set_Etype (N, Any_Type);
1607 -- Shouldn't the following statement be down in the ELSE of the
1608 -- following loop? ???
1610 Get_First_Interp (Then_Expr, I, It);
1612 -- if no Else_Expression the conditional must be boolean
1614 if No (Else_Expr) then
1615 Set_Etype (N, Standard_Boolean);
1617 -- Else_Expression Present. For each possible intepretation of
1618 -- the Then_Expression, add it only if the Else_Expression has
1619 -- a compatible type.
1622 while Present (It.Nam) loop
1623 if Has_Compatible_Type (Else_Expr, It.Typ) then
1624 Add_One_Interp (N, It.Typ, It.Typ);
1627 Get_Next_Interp (I, It);
1632 end Analyze_Conditional_Expression;
1634 -------------------------
1635 -- Analyze_Equality_Op --
1636 -------------------------
1638 procedure Analyze_Equality_Op (N : Node_Id) is
1639 Loc : constant Source_Ptr := Sloc (N);
1640 L : constant Node_Id := Left_Opnd (N);
1641 R : constant Node_Id := Right_Opnd (N);
1645 Set_Etype (N, Any_Type);
1646 Candidate_Type := Empty;
1648 Analyze_Expression (L);
1649 Analyze_Expression (R);
1651 -- If the entity is set, the node is a generic instance with a non-local
1652 -- reference to the predefined operator or to a user-defined function.
1653 -- It can also be an inequality that is expanded into the negation of a
1654 -- call to a user-defined equality operator.
1656 -- For the predefined case, the result is Boolean, regardless of the
1657 -- type of the operands. The operands may even be limited, if they are
1658 -- generic actuals. If they are overloaded, label the left argument with
1659 -- the common type that must be present, or with the type of the formal
1660 -- of the user-defined function.
1662 if Present (Entity (N)) then
1663 Op_Id := Entity (N);
1665 if Ekind (Op_Id) = E_Operator then
1666 Add_One_Interp (N, Op_Id, Standard_Boolean);
1668 Add_One_Interp (N, Op_Id, Etype (Op_Id));
1671 if Is_Overloaded (L) then
1672 if Ekind (Op_Id) = E_Operator then
1673 Set_Etype (L, Intersect_Types (L, R));
1675 Set_Etype (L, Etype (First_Formal (Op_Id)));
1680 Op_Id := Get_Name_Entity_Id (Chars (N));
1681 while Present (Op_Id) loop
1682 if Ekind (Op_Id) = E_Operator then
1683 Find_Equality_Types (L, R, Op_Id, N);
1685 Analyze_User_Defined_Binary_Op (N, Op_Id);
1688 Op_Id := Homonym (Op_Id);
1692 -- If there was no match, and the operator is inequality, this may
1693 -- be a case where inequality has not been made explicit, as for
1694 -- tagged types. Analyze the node as the negation of an equality
1695 -- operation. This cannot be done earlier, because before analysis
1696 -- we cannot rule out the presence of an explicit inequality.
1698 if Etype (N) = Any_Type
1699 and then Nkind (N) = N_Op_Ne
1701 Op_Id := Get_Name_Entity_Id (Name_Op_Eq);
1702 while Present (Op_Id) loop
1703 if Ekind (Op_Id) = E_Operator then
1704 Find_Equality_Types (L, R, Op_Id, N);
1706 Analyze_User_Defined_Binary_Op (N, Op_Id);
1709 Op_Id := Homonym (Op_Id);
1712 if Etype (N) /= Any_Type then
1713 Op_Id := Entity (N);
1719 Left_Opnd => Left_Opnd (N),
1720 Right_Opnd => Right_Opnd (N))));
1722 Set_Entity (Right_Opnd (N), Op_Id);
1728 end Analyze_Equality_Op;
1730 ----------------------------------
1731 -- Analyze_Explicit_Dereference --
1732 ----------------------------------
1734 procedure Analyze_Explicit_Dereference (N : Node_Id) is
1735 Loc : constant Source_Ptr := Sloc (N);
1736 P : constant Node_Id := Prefix (N);
1742 function Is_Function_Type return Boolean;
1743 -- Check whether node may be interpreted as an implicit function call
1745 ----------------------
1746 -- Is_Function_Type --
1747 ----------------------
1749 function Is_Function_Type return Boolean is
1754 if not Is_Overloaded (N) then
1755 return Ekind (Base_Type (Etype (N))) = E_Subprogram_Type
1756 and then Etype (Base_Type (Etype (N))) /= Standard_Void_Type;
1759 Get_First_Interp (N, I, It);
1760 while Present (It.Nam) loop
1761 if Ekind (Base_Type (It.Typ)) /= E_Subprogram_Type
1762 or else Etype (Base_Type (It.Typ)) = Standard_Void_Type
1767 Get_Next_Interp (I, It);
1772 end Is_Function_Type;
1774 -- Start of processing for Analyze_Explicit_Dereference
1777 -- If source node, check SPARK restriction. We guard this with the
1778 -- source node check, because ???
1780 if Comes_From_Source (N) then
1781 Check_SPARK_Restriction ("explicit dereference is not allowed", N);
1784 -- In formal verification mode, keep track of all reads and writes
1785 -- through explicit dereferences.
1788 Alfa.Generate_Dereference (N);
1792 Set_Etype (N, Any_Type);
1794 -- Test for remote access to subprogram type, and if so return
1795 -- after rewriting the original tree.
1797 if Remote_AST_E_Dereference (P) then
1801 -- Normal processing for other than remote access to subprogram type
1803 if not Is_Overloaded (P) then
1804 if Is_Access_Type (Etype (P)) then
1806 -- Set the Etype. We need to go through Is_For_Access_Subtypes to
1807 -- avoid other problems caused by the Private_Subtype and it is
1808 -- safe to go to the Base_Type because this is the same as
1809 -- converting the access value to its Base_Type.
1812 DT : Entity_Id := Designated_Type (Etype (P));
1815 if Ekind (DT) = E_Private_Subtype
1816 and then Is_For_Access_Subtype (DT)
1818 DT := Base_Type (DT);
1821 -- An explicit dereference is a legal occurrence of an
1822 -- incomplete type imported through a limited_with clause,
1823 -- if the full view is visible.
1825 if From_With_Type (DT)
1826 and then not From_With_Type (Scope (DT))
1828 (Is_Immediately_Visible (Scope (DT))
1830 (Is_Child_Unit (Scope (DT))
1831 and then Is_Visible_Child_Unit (Scope (DT))))
1833 Set_Etype (N, Available_View (DT));
1840 elsif Etype (P) /= Any_Type then
1841 Error_Msg_N ("prefix of dereference must be an access type", N);
1846 Get_First_Interp (P, I, It);
1847 while Present (It.Nam) loop
1850 if Is_Access_Type (T) then
1851 Add_One_Interp (N, Designated_Type (T), Designated_Type (T));
1854 Get_Next_Interp (I, It);
1857 -- Error if no interpretation of the prefix has an access type
1859 if Etype (N) = Any_Type then
1861 ("access type required in prefix of explicit dereference", P);
1862 Set_Etype (N, Any_Type);
1868 and then Nkind (Parent (N)) /= N_Indexed_Component
1870 and then (Nkind (Parent (N)) /= N_Function_Call
1871 or else N /= Name (Parent (N)))
1873 and then (Nkind (Parent (N)) /= N_Procedure_Call_Statement
1874 or else N /= Name (Parent (N)))
1876 and then Nkind (Parent (N)) /= N_Subprogram_Renaming_Declaration
1877 and then (Nkind (Parent (N)) /= N_Attribute_Reference
1879 (Attribute_Name (Parent (N)) /= Name_Address
1881 Attribute_Name (Parent (N)) /= Name_Access))
1883 -- Name is a function call with no actuals, in a context that
1884 -- requires deproceduring (including as an actual in an enclosing
1885 -- function or procedure call). There are some pathological cases
1886 -- where the prefix might include functions that return access to
1887 -- subprograms and others that return a regular type. Disambiguation
1888 -- of those has to take place in Resolve.
1891 Make_Function_Call (Loc,
1892 Name => Make_Explicit_Dereference (Loc, P),
1893 Parameter_Associations => New_List);
1895 -- If the prefix is overloaded, remove operations that have formals,
1896 -- we know that this is a parameterless call.
1898 if Is_Overloaded (P) then
1899 Get_First_Interp (P, I, It);
1900 while Present (It.Nam) loop
1903 if No (First_Formal (Base_Type (Designated_Type (T)))) then
1909 Get_Next_Interp (I, It);
1916 elsif not Is_Function_Type
1917 and then Is_Overloaded (N)
1919 -- The prefix may include access to subprograms and other access
1920 -- types. If the context selects the interpretation that is a
1921 -- function call (not a procedure call) we cannot rewrite the node
1922 -- yet, but we include the result of the call interpretation.
1924 Get_First_Interp (N, I, It);
1925 while Present (It.Nam) loop
1926 if Ekind (Base_Type (It.Typ)) = E_Subprogram_Type
1927 and then Etype (Base_Type (It.Typ)) /= Standard_Void_Type
1928 and then Nkind (Parent (N)) /= N_Procedure_Call_Statement
1930 Add_One_Interp (N, Etype (It.Typ), Etype (It.Typ));
1933 Get_Next_Interp (I, It);
1937 -- A value of remote access-to-class-wide must not be dereferenced
1940 Validate_Remote_Access_To_Class_Wide_Type (N);
1941 end Analyze_Explicit_Dereference;
1943 ------------------------
1944 -- Analyze_Expression --
1945 ------------------------
1947 procedure Analyze_Expression (N : Node_Id) is
1950 Check_Parameterless_Call (N);
1951 end Analyze_Expression;
1953 -------------------------------------
1954 -- Analyze_Expression_With_Actions --
1955 -------------------------------------
1957 procedure Analyze_Expression_With_Actions (N : Node_Id) is
1961 A := First (Actions (N));
1968 Analyze_Expression (Expression (N));
1969 Set_Etype (N, Etype (Expression (N)));
1970 end Analyze_Expression_With_Actions;
1972 ------------------------------------
1973 -- Analyze_Indexed_Component_Form --
1974 ------------------------------------
1976 procedure Analyze_Indexed_Component_Form (N : Node_Id) is
1977 P : constant Node_Id := Prefix (N);
1978 Exprs : constant List_Id := Expressions (N);
1984 procedure Process_Function_Call;
1985 -- Prefix in indexed component form is an overloadable entity,
1986 -- so the node is a function call. Reformat it as such.
1988 procedure Process_Indexed_Component;
1989 -- Prefix in indexed component form is actually an indexed component.
1990 -- This routine processes it, knowing that the prefix is already
1993 procedure Process_Indexed_Component_Or_Slice;
1994 -- An indexed component with a single index may designate a slice if
1995 -- the index is a subtype mark. This routine disambiguates these two
1996 -- cases by resolving the prefix to see if it is a subtype mark.
1998 procedure Process_Overloaded_Indexed_Component;
1999 -- If the prefix of an indexed component is overloaded, the proper
2000 -- interpretation is selected by the index types and the context.
2002 ---------------------------
2003 -- Process_Function_Call --
2004 ---------------------------
2006 procedure Process_Function_Call is
2010 Change_Node (N, N_Function_Call);
2012 Set_Parameter_Associations (N, Exprs);
2014 -- Analyze actuals prior to analyzing the call itself
2016 Actual := First (Parameter_Associations (N));
2017 while Present (Actual) loop
2019 Check_Parameterless_Call (Actual);
2021 -- Move to next actual. Note that we use Next, not Next_Actual
2022 -- here. The reason for this is a bit subtle. If a function call
2023 -- includes named associations, the parser recognizes the node as
2024 -- a call, and it is analyzed as such. If all associations are
2025 -- positional, the parser builds an indexed_component node, and
2026 -- it is only after analysis of the prefix that the construct
2027 -- is recognized as a call, in which case Process_Function_Call
2028 -- rewrites the node and analyzes the actuals. If the list of
2029 -- actuals is malformed, the parser may leave the node as an
2030 -- indexed component (despite the presence of named associations).
2031 -- The iterator Next_Actual is equivalent to Next if the list is
2032 -- positional, but follows the normalized chain of actuals when
2033 -- named associations are present. In this case normalization has
2034 -- not taken place, and actuals remain unanalyzed, which leads to
2035 -- subsequent crashes or loops if there is an attempt to continue
2036 -- analysis of the program.
2042 end Process_Function_Call;
2044 -------------------------------
2045 -- Process_Indexed_Component --
2046 -------------------------------
2048 procedure Process_Indexed_Component is
2050 Array_Type : Entity_Id;
2052 Pent : Entity_Id := Empty;
2055 Exp := First (Exprs);
2057 if Is_Overloaded (P) then
2058 Process_Overloaded_Indexed_Component;
2061 Array_Type := Etype (P);
2063 if Is_Entity_Name (P) then
2065 elsif Nkind (P) = N_Selected_Component
2066 and then Is_Entity_Name (Selector_Name (P))
2068 Pent := Entity (Selector_Name (P));
2071 -- Prefix must be appropriate for an array type, taking into
2072 -- account a possible implicit dereference.
2074 if Is_Access_Type (Array_Type) then
2075 Error_Msg_NW (Warn_On_Dereference, "?implicit dereference", N);
2076 Array_Type := Process_Implicit_Dereference_Prefix (Pent, P);
2079 if Is_Array_Type (Array_Type) then
2082 elsif Present (Pent) and then Ekind (Pent) = E_Entry_Family then
2084 Set_Etype (N, Any_Type);
2086 if not Has_Compatible_Type
2087 (Exp, Entry_Index_Type (Pent))
2089 Error_Msg_N ("invalid index type in entry name", N);
2091 elsif Present (Next (Exp)) then
2092 Error_Msg_N ("too many subscripts in entry reference", N);
2095 Set_Etype (N, Etype (P));
2100 elsif Is_Record_Type (Array_Type)
2101 and then Remote_AST_I_Dereference (P)
2105 elsif Try_Container_Indexing (N, P, Exp) then
2108 elsif Array_Type = Any_Type then
2109 Set_Etype (N, Any_Type);
2111 -- In most cases the analysis of the prefix will have emitted
2112 -- an error already, but if the prefix may be interpreted as a
2113 -- call in prefixed notation, the report is left to the caller.
2114 -- To prevent cascaded errors, report only if no previous ones.
2116 if Serious_Errors_Detected = 0 then
2117 Error_Msg_N ("invalid prefix in indexed component", P);
2119 if Nkind (P) = N_Expanded_Name then
2120 Error_Msg_NE ("\& is not visible", P, Selector_Name (P));
2126 -- Here we definitely have a bad indexing
2129 if Nkind (Parent (N)) = N_Requeue_Statement
2130 and then Present (Pent) and then Ekind (Pent) = E_Entry
2133 ("REQUEUE does not permit parameters", First (Exprs));
2135 elsif Is_Entity_Name (P)
2136 and then Etype (P) = Standard_Void_Type
2138 Error_Msg_NE ("incorrect use of&", P, Entity (P));
2141 Error_Msg_N ("array type required in indexed component", P);
2144 Set_Etype (N, Any_Type);
2148 Index := First_Index (Array_Type);
2149 while Present (Index) and then Present (Exp) loop
2150 if not Has_Compatible_Type (Exp, Etype (Index)) then
2151 Wrong_Type (Exp, Etype (Index));
2152 Set_Etype (N, Any_Type);
2160 Set_Etype (N, Component_Type (Array_Type));
2161 Check_Implicit_Dereference (N, Etype (N));
2163 if Present (Index) then
2165 ("too few subscripts in array reference", First (Exprs));
2167 elsif Present (Exp) then
2168 Error_Msg_N ("too many subscripts in array reference", Exp);
2171 end Process_Indexed_Component;
2173 ----------------------------------------
2174 -- Process_Indexed_Component_Or_Slice --
2175 ----------------------------------------
2177 procedure Process_Indexed_Component_Or_Slice is
2179 Exp := First (Exprs);
2180 while Present (Exp) loop
2181 Analyze_Expression (Exp);
2185 Exp := First (Exprs);
2187 -- If one index is present, and it is a subtype name, then the
2188 -- node denotes a slice (note that the case of an explicit range
2189 -- for a slice was already built as an N_Slice node in the first
2190 -- place, so that case is not handled here).
2192 -- We use a replace rather than a rewrite here because this is one
2193 -- of the cases in which the tree built by the parser is plain wrong.
2196 and then Is_Entity_Name (Exp)
2197 and then Is_Type (Entity (Exp))
2200 Make_Slice (Sloc (N),
2202 Discrete_Range => New_Copy (Exp)));
2205 -- Otherwise (more than one index present, or single index is not
2206 -- a subtype name), then we have the indexed component case.
2209 Process_Indexed_Component;
2211 end Process_Indexed_Component_Or_Slice;
2213 ------------------------------------------
2214 -- Process_Overloaded_Indexed_Component --
2215 ------------------------------------------
2217 procedure Process_Overloaded_Indexed_Component is
2226 Set_Etype (N, Any_Type);
2228 Get_First_Interp (P, I, It);
2229 while Present (It.Nam) loop
2232 if Is_Access_Type (Typ) then
2233 Typ := Designated_Type (Typ);
2234 Error_Msg_NW (Warn_On_Dereference, "?implicit dereference", N);
2237 if Is_Array_Type (Typ) then
2239 -- Got a candidate: verify that index types are compatible
2241 Index := First_Index (Typ);
2243 Exp := First (Exprs);
2244 while Present (Index) and then Present (Exp) loop
2245 if Has_Compatible_Type (Exp, Etype (Index)) then
2257 if Found and then No (Index) and then No (Exp) then
2259 CT : constant Entity_Id :=
2260 Base_Type (Component_Type (Typ));
2262 Add_One_Interp (N, CT, CT);
2263 Check_Implicit_Dereference (N, CT);
2267 elsif Try_Container_Indexing (N, P, First (Exprs)) then
2272 Get_Next_Interp (I, It);
2275 if Etype (N) = Any_Type then
2276 Error_Msg_N ("no legal interpretation for indexed component", N);
2277 Set_Is_Overloaded (N, False);
2281 end Process_Overloaded_Indexed_Component;
2283 -- Start of processing for Analyze_Indexed_Component_Form
2286 -- Get name of array, function or type
2290 if Nkind_In (N, N_Function_Call, N_Procedure_Call_Statement) then
2292 -- If P is an explicit dereference whose prefix is of a
2293 -- remote access-to-subprogram type, then N has already
2294 -- been rewritten as a subprogram call and analyzed.
2299 pragma Assert (Nkind (N) = N_Indexed_Component);
2301 P_T := Base_Type (Etype (P));
2303 if Is_Entity_Name (P) and then Present (Entity (P)) then
2306 if Is_Type (U_N) then
2308 -- Reformat node as a type conversion
2310 E := Remove_Head (Exprs);
2312 if Present (First (Exprs)) then
2314 ("argument of type conversion must be single expression", N);
2317 Change_Node (N, N_Type_Conversion);
2318 Set_Subtype_Mark (N, P);
2320 Set_Expression (N, E);
2322 -- After changing the node, call for the specific Analysis
2323 -- routine directly, to avoid a double call to the expander.
2325 Analyze_Type_Conversion (N);
2329 if Is_Overloadable (U_N) then
2330 Process_Function_Call;
2332 elsif Ekind (Etype (P)) = E_Subprogram_Type
2333 or else (Is_Access_Type (Etype (P))
2335 Ekind (Designated_Type (Etype (P))) =
2338 -- Call to access_to-subprogram with possible implicit dereference
2340 Process_Function_Call;
2342 elsif Is_Generic_Subprogram (U_N) then
2344 -- A common beginner's (or C++ templates fan) error
2346 Error_Msg_N ("generic subprogram cannot be called", N);
2347 Set_Etype (N, Any_Type);
2351 Process_Indexed_Component_Or_Slice;
2354 -- If not an entity name, prefix is an expression that may denote
2355 -- an array or an access-to-subprogram.
2358 if Ekind (P_T) = E_Subprogram_Type
2359 or else (Is_Access_Type (P_T)
2361 Ekind (Designated_Type (P_T)) = E_Subprogram_Type)
2363 Process_Function_Call;
2365 elsif Nkind (P) = N_Selected_Component
2366 and then Is_Overloadable (Entity (Selector_Name (P)))
2368 Process_Function_Call;
2371 -- Indexed component, slice, or a call to a member of a family
2372 -- entry, which will be converted to an entry call later.
2374 Process_Indexed_Component_Or_Slice;
2377 end Analyze_Indexed_Component_Form;
2379 ------------------------
2380 -- Analyze_Logical_Op --
2381 ------------------------
2383 procedure Analyze_Logical_Op (N : Node_Id) is
2384 L : constant Node_Id := Left_Opnd (N);
2385 R : constant Node_Id := Right_Opnd (N);
2386 Op_Id : Entity_Id := Entity (N);
2389 Set_Etype (N, Any_Type);
2390 Candidate_Type := Empty;
2392 Analyze_Expression (L);
2393 Analyze_Expression (R);
2395 if Present (Op_Id) then
2397 if Ekind (Op_Id) = E_Operator then
2398 Find_Boolean_Types (L, R, Op_Id, N);
2400 Add_One_Interp (N, Op_Id, Etype (Op_Id));
2404 Op_Id := Get_Name_Entity_Id (Chars (N));
2405 while Present (Op_Id) loop
2406 if Ekind (Op_Id) = E_Operator then
2407 Find_Boolean_Types (L, R, Op_Id, N);
2409 Analyze_User_Defined_Binary_Op (N, Op_Id);
2412 Op_Id := Homonym (Op_Id);
2417 end Analyze_Logical_Op;
2419 ---------------------------
2420 -- Analyze_Membership_Op --
2421 ---------------------------
2423 procedure Analyze_Membership_Op (N : Node_Id) is
2424 Loc : constant Source_Ptr := Sloc (N);
2425 L : constant Node_Id := Left_Opnd (N);
2426 R : constant Node_Id := Right_Opnd (N);
2428 Index : Interp_Index;
2430 Found : Boolean := False;
2434 procedure Try_One_Interp (T1 : Entity_Id);
2435 -- Routine to try one proposed interpretation. Note that the context
2436 -- of the operation plays no role in resolving the arguments, so that
2437 -- if there is more than one interpretation of the operands that is
2438 -- compatible with a membership test, the operation is ambiguous.
2440 --------------------
2441 -- Try_One_Interp --
2442 --------------------
2444 procedure Try_One_Interp (T1 : Entity_Id) is
2446 if Has_Compatible_Type (R, T1) then
2448 and then Base_Type (T1) /= Base_Type (T_F)
2450 It := Disambiguate (L, I_F, Index, Any_Type);
2452 if It = No_Interp then
2453 Ambiguous_Operands (N);
2454 Set_Etype (L, Any_Type);
2471 procedure Analyze_Set_Membership;
2472 -- If a set of alternatives is present, analyze each and find the
2473 -- common type to which they must all resolve.
2475 ----------------------------
2476 -- Analyze_Set_Membership --
2477 ----------------------------
2479 procedure Analyze_Set_Membership is
2481 Index : Interp_Index;
2483 Candidate_Interps : Node_Id;
2484 Common_Type : Entity_Id := Empty;
2488 Candidate_Interps := L;
2490 if not Is_Overloaded (L) then
2491 Common_Type := Etype (L);
2493 Alt := First (Alternatives (N));
2494 while Present (Alt) loop
2497 if not Has_Compatible_Type (Alt, Common_Type) then
2498 Wrong_Type (Alt, Common_Type);
2505 Alt := First (Alternatives (N));
2506 while Present (Alt) loop
2508 if not Is_Overloaded (Alt) then
2509 Common_Type := Etype (Alt);
2512 Get_First_Interp (Alt, Index, It);
2513 while Present (It.Typ) loop
2515 Has_Compatible_Type (Candidate_Interps, It.Typ)
2517 Remove_Interp (Index);
2520 Get_Next_Interp (Index, It);
2523 Get_First_Interp (Alt, Index, It);
2526 Error_Msg_N ("alternative has no legal type", Alt);
2530 -- If alternative is not overloaded, we have a unique type
2533 Set_Etype (Alt, It.Typ);
2534 Get_Next_Interp (Index, It);
2537 Set_Is_Overloaded (Alt, False);
2538 Common_Type := Etype (Alt);
2541 Candidate_Interps := Alt;
2548 Set_Etype (N, Standard_Boolean);
2550 if Present (Common_Type) then
2551 Set_Etype (L, Common_Type);
2552 Set_Is_Overloaded (L, False);
2555 Error_Msg_N ("cannot resolve membership operation", N);
2557 end Analyze_Set_Membership;
2559 -- Start of processing for Analyze_Membership_Op
2562 Analyze_Expression (L);
2565 and then Ada_Version >= Ada_2012
2567 Analyze_Set_Membership;
2571 if Nkind (R) = N_Range
2572 or else (Nkind (R) = N_Attribute_Reference
2573 and then Attribute_Name (R) = Name_Range)
2577 if not Is_Overloaded (L) then
2578 Try_One_Interp (Etype (L));
2581 Get_First_Interp (L, Index, It);
2582 while Present (It.Typ) loop
2583 Try_One_Interp (It.Typ);
2584 Get_Next_Interp (Index, It);
2588 -- If not a range, it can be a subtype mark, or else it is a degenerate
2589 -- membership test with a singleton value, i.e. a test for equality,
2590 -- if the types are compatible.
2595 if Is_Entity_Name (R)
2596 and then Is_Type (Entity (R))
2599 Check_Fully_Declared (Entity (R), R);
2601 elsif Ada_Version >= Ada_2012
2602 and then Has_Compatible_Type (R, Etype (L))
2604 if Nkind (N) = N_In then
2620 -- In all versions of the language, if we reach this point there
2621 -- is a previous error that will be diagnosed below.
2627 -- Compatibility between expression and subtype mark or range is
2628 -- checked during resolution. The result of the operation is Boolean
2631 Set_Etype (N, Standard_Boolean);
2633 if Comes_From_Source (N)
2634 and then Present (Right_Opnd (N))
2635 and then Is_CPP_Class (Etype (Etype (Right_Opnd (N))))
2637 Error_Msg_N ("membership test not applicable to cpp-class types", N);
2639 end Analyze_Membership_Op;
2645 procedure Analyze_Mod (N : Node_Id) is
2647 -- A special warning check, if we have an expression of the form:
2648 -- expr mod 2 * literal
2649 -- where literal is 64 or less, then probably what was meant was
2650 -- expr mod 2 ** literal
2651 -- so issue an appropriate warning.
2653 if Warn_On_Suspicious_Modulus_Value
2654 and then Nkind (Right_Opnd (N)) = N_Integer_Literal
2655 and then Intval (Right_Opnd (N)) = Uint_2
2656 and then Nkind (Parent (N)) = N_Op_Multiply
2657 and then Nkind (Right_Opnd (Parent (N))) = N_Integer_Literal
2658 and then Intval (Right_Opnd (Parent (N))) <= Uint_64
2661 ("suspicious MOD value, was '*'* intended'??", Parent (N));
2664 -- Remaining processing is same as for other arithmetic operators
2666 Analyze_Arithmetic_Op (N);
2669 ----------------------
2670 -- Analyze_Negation --
2671 ----------------------
2673 procedure Analyze_Negation (N : Node_Id) is
2674 R : constant Node_Id := Right_Opnd (N);
2675 Op_Id : Entity_Id := Entity (N);
2678 Set_Etype (N, Any_Type);
2679 Candidate_Type := Empty;
2681 Analyze_Expression (R);
2683 if Present (Op_Id) then
2684 if Ekind (Op_Id) = E_Operator then
2685 Find_Negation_Types (R, Op_Id, N);
2687 Add_One_Interp (N, Op_Id, Etype (Op_Id));
2691 Op_Id := Get_Name_Entity_Id (Chars (N));
2692 while Present (Op_Id) loop
2693 if Ekind (Op_Id) = E_Operator then
2694 Find_Negation_Types (R, Op_Id, N);
2696 Analyze_User_Defined_Unary_Op (N, Op_Id);
2699 Op_Id := Homonym (Op_Id);
2704 end Analyze_Negation;
2710 procedure Analyze_Null (N : Node_Id) is
2712 Check_SPARK_Restriction ("null is not allowed", N);
2714 Set_Etype (N, Any_Access);
2717 ----------------------
2718 -- Analyze_One_Call --
2719 ----------------------
2721 procedure Analyze_One_Call
2725 Success : out Boolean;
2726 Skip_First : Boolean := False)
2728 Actuals : constant List_Id := Parameter_Associations (N);
2729 Prev_T : constant Entity_Id := Etype (N);
2731 Must_Skip : constant Boolean := Skip_First
2732 or else Nkind (Original_Node (N)) = N_Selected_Component
2734 (Nkind (Original_Node (N)) = N_Indexed_Component
2735 and then Nkind (Prefix (Original_Node (N)))
2736 = N_Selected_Component);
2737 -- The first formal must be omitted from the match when trying to find
2738 -- a primitive operation that is a possible interpretation, and also
2739 -- after the call has been rewritten, because the corresponding actual
2740 -- is already known to be compatible, and because this may be an
2741 -- indexing of a call with default parameters.
2745 Is_Indexed : Boolean := False;
2746 Is_Indirect : Boolean := False;
2747 Subp_Type : constant Entity_Id := Etype (Nam);
2750 function Operator_Hidden_By (Fun : Entity_Id) return Boolean;
2751 -- There may be a user-defined operator that hides the current
2752 -- interpretation. We must check for this independently of the
2753 -- analysis of the call with the user-defined operation, because
2754 -- the parameter names may be wrong and yet the hiding takes place.
2755 -- This fixes a problem with ACATS test B34014O.
2757 -- When the type Address is a visible integer type, and the DEC
2758 -- system extension is visible, the predefined operator may be
2759 -- hidden as well, by one of the address operations in auxdec.
2760 -- Finally, The abstract operations on address do not hide the
2761 -- predefined operator (this is the purpose of making them abstract).
2763 procedure Indicate_Name_And_Type;
2764 -- If candidate interpretation matches, indicate name and type of
2765 -- result on call node.
2767 ----------------------------
2768 -- Indicate_Name_And_Type --
2769 ----------------------------
2771 procedure Indicate_Name_And_Type is
2773 Add_One_Interp (N, Nam, Etype (Nam));
2774 Check_Implicit_Dereference (N, Etype (Nam));
2777 -- If the prefix of the call is a name, indicate the entity
2778 -- being called. If it is not a name, it is an expression that
2779 -- denotes an access to subprogram or else an entry or family. In
2780 -- the latter case, the name is a selected component, and the entity
2781 -- being called is noted on the selector.
2783 if not Is_Type (Nam) then
2784 if Is_Entity_Name (Name (N)) then
2785 Set_Entity (Name (N), Nam);
2787 elsif Nkind (Name (N)) = N_Selected_Component then
2788 Set_Entity (Selector_Name (Name (N)), Nam);
2792 if Debug_Flag_E and not Report then
2793 Write_Str (" Overloaded call ");
2794 Write_Int (Int (N));
2795 Write_Str (" compatible with ");
2796 Write_Int (Int (Nam));
2799 end Indicate_Name_And_Type;
2801 ------------------------
2802 -- Operator_Hidden_By --
2803 ------------------------
2805 function Operator_Hidden_By (Fun : Entity_Id) return Boolean is
2806 Act1 : constant Node_Id := First_Actual (N);
2807 Act2 : constant Node_Id := Next_Actual (Act1);
2808 Form1 : constant Entity_Id := First_Formal (Fun);
2809 Form2 : constant Entity_Id := Next_Formal (Form1);
2812 if Ekind (Fun) /= E_Function
2813 or else Is_Abstract_Subprogram (Fun)
2817 elsif not Has_Compatible_Type (Act1, Etype (Form1)) then
2820 elsif Present (Form2) then
2822 No (Act2) or else not Has_Compatible_Type (Act2, Etype (Form2))
2827 elsif Present (Act2) then
2831 -- Now we know that the arity of the operator matches the function,
2832 -- and the function call is a valid interpretation. The function
2833 -- hides the operator if it has the right signature, or if one of
2834 -- its operands is a non-abstract operation on Address when this is
2835 -- a visible integer type.
2837 return Hides_Op (Fun, Nam)
2838 or else Is_Descendent_Of_Address (Etype (Form1))
2841 and then Is_Descendent_Of_Address (Etype (Form2)));
2842 end Operator_Hidden_By;
2844 -- Start of processing for Analyze_One_Call
2849 -- If the subprogram has no formals or if all the formals have defaults,
2850 -- and the return type is an array type, the node may denote an indexing
2851 -- of the result of a parameterless call. In Ada 2005, the subprogram
2852 -- may have one non-defaulted formal, and the call may have been written
2853 -- in prefix notation, so that the rebuilt parameter list has more than
2856 if not Is_Overloadable (Nam)
2857 and then Ekind (Nam) /= E_Subprogram_Type
2858 and then Ekind (Nam) /= E_Entry_Family
2863 -- An indexing requires at least one actual
2865 if not Is_Empty_List (Actuals)
2867 (Needs_No_Actuals (Nam)
2869 (Needs_One_Actual (Nam)
2870 and then Present (Next_Actual (First (Actuals)))))
2872 if Is_Array_Type (Subp_Type) then
2873 Is_Indexed := Try_Indexed_Call (N, Nam, Subp_Type, Must_Skip);
2875 elsif Is_Access_Type (Subp_Type)
2876 and then Is_Array_Type (Designated_Type (Subp_Type))
2880 (N, Nam, Designated_Type (Subp_Type), Must_Skip);
2882 -- The prefix can also be a parameterless function that returns an
2883 -- access to subprogram, in which case this is an indirect call.
2884 -- If this succeeds, an explicit dereference is added later on,
2885 -- in Analyze_Call or Resolve_Call.
2887 elsif Is_Access_Type (Subp_Type)
2888 and then Ekind (Designated_Type (Subp_Type)) = E_Subprogram_Type
2890 Is_Indirect := Try_Indirect_Call (N, Nam, Subp_Type);
2895 -- If the call has been transformed into a slice, it is of the form
2896 -- F (Subtype) where F is parameterless. The node has been rewritten in
2897 -- Try_Indexed_Call and there is nothing else to do.
2900 and then Nkind (N) = N_Slice
2906 (N, Nam, (Report and not Is_Indexed and not Is_Indirect), Norm_OK);
2910 -- If an indirect call is a possible interpretation, indicate
2911 -- success to the caller.
2917 -- Mismatch in number or names of parameters
2919 elsif Debug_Flag_E then
2920 Write_Str (" normalization fails in call ");
2921 Write_Int (Int (N));
2922 Write_Str (" with subprogram ");
2923 Write_Int (Int (Nam));
2927 -- If the context expects a function call, discard any interpretation
2928 -- that is a procedure. If the node is not overloaded, leave as is for
2929 -- better error reporting when type mismatch is found.
2931 elsif Nkind (N) = N_Function_Call
2932 and then Is_Overloaded (Name (N))
2933 and then Ekind (Nam) = E_Procedure
2937 -- Ditto for function calls in a procedure context
2939 elsif Nkind (N) = N_Procedure_Call_Statement
2940 and then Is_Overloaded (Name (N))
2941 and then Etype (Nam) /= Standard_Void_Type
2945 elsif No (Actuals) then
2947 -- If Normalize succeeds, then there are default parameters for
2950 Indicate_Name_And_Type;
2952 elsif Ekind (Nam) = E_Operator then
2953 if Nkind (N) = N_Procedure_Call_Statement then
2957 -- This can occur when the prefix of the call is an operator
2958 -- name or an expanded name whose selector is an operator name.
2960 Analyze_Operator_Call (N, Nam);
2962 if Etype (N) /= Prev_T then
2964 -- Check that operator is not hidden by a function interpretation
2966 if Is_Overloaded (Name (N)) then
2972 Get_First_Interp (Name (N), I, It);
2973 while Present (It.Nam) loop
2974 if Operator_Hidden_By (It.Nam) then
2975 Set_Etype (N, Prev_T);
2979 Get_Next_Interp (I, It);
2984 -- If operator matches formals, record its name on the call.
2985 -- If the operator is overloaded, Resolve will select the
2986 -- correct one from the list of interpretations. The call
2987 -- node itself carries the first candidate.
2989 Set_Entity (Name (N), Nam);
2992 elsif Report and then Etype (N) = Any_Type then
2993 Error_Msg_N ("incompatible arguments for operator", N);
2997 -- Normalize_Actuals has chained the named associations in the
2998 -- correct order of the formals.
3000 Actual := First_Actual (N);
3001 Formal := First_Formal (Nam);
3003 -- If we are analyzing a call rewritten from object notation, skip
3004 -- first actual, which may be rewritten later as an explicit
3008 Next_Actual (Actual);
3009 Next_Formal (Formal);
3012 while Present (Actual) and then Present (Formal) loop
3013 if Nkind (Parent (Actual)) /= N_Parameter_Association
3014 or else Chars (Selector_Name (Parent (Actual))) = Chars (Formal)
3016 -- The actual can be compatible with the formal, but we must
3017 -- also check that the context is not an address type that is
3018 -- visibly an integer type, as is the case in VMS_64. In this
3019 -- case the use of literals is illegal, except in the body of
3020 -- descendents of system, where arithmetic operations on
3021 -- address are of course used.
3023 if Has_Compatible_Type (Actual, Etype (Formal))
3025 (Etype (Actual) /= Universal_Integer
3026 or else not Is_Descendent_Of_Address (Etype (Formal))
3028 Is_Predefined_File_Name
3029 (Unit_File_Name (Get_Source_Unit (N))))
3031 Next_Actual (Actual);
3032 Next_Formal (Formal);
3035 if Debug_Flag_E then
3036 Write_Str (" type checking fails in call ");
3037 Write_Int (Int (N));
3038 Write_Str (" with formal ");
3039 Write_Int (Int (Formal));
3040 Write_Str (" in subprogram ");
3041 Write_Int (Int (Nam));
3045 if Report and not Is_Indexed and not Is_Indirect then
3047 -- Ada 2005 (AI-251): Complete the error notification
3048 -- to help new Ada 2005 users.
3050 if Is_Class_Wide_Type (Etype (Formal))
3051 and then Is_Interface (Etype (Etype (Formal)))
3052 and then not Interface_Present_In_Ancestor
3053 (Typ => Etype (Actual),
3054 Iface => Etype (Etype (Formal)))
3057 ("(Ada 2005) does not implement interface }",
3058 Actual, Etype (Etype (Formal)));
3061 Wrong_Type (Actual, Etype (Formal));
3063 if Nkind (Actual) = N_Op_Eq
3064 and then Nkind (Left_Opnd (Actual)) = N_Identifier
3066 Formal := First_Formal (Nam);
3067 while Present (Formal) loop
3068 if Chars (Left_Opnd (Actual)) = Chars (Formal) then
3069 Error_Msg_N -- CODEFIX
3070 ("possible misspelling of `='>`!", Actual);
3074 Next_Formal (Formal);
3078 if All_Errors_Mode then
3079 Error_Msg_Sloc := Sloc (Nam);
3081 if Etype (Formal) = Any_Type then
3083 ("there is no legal actual parameter", Actual);
3086 if Is_Overloadable (Nam)
3087 and then Present (Alias (Nam))
3088 and then not Comes_From_Source (Nam)
3091 ("\\ =='> in call to inherited operation & #!",
3094 elsif Ekind (Nam) = E_Subprogram_Type then
3096 Access_To_Subprogram_Typ :
3097 constant Entity_Id :=
3099 (Associated_Node_For_Itype (Nam));
3102 "\\ =='> in call to dereference of &#!",
3103 Actual, Access_To_Subprogram_Typ);
3108 ("\\ =='> in call to &#!", Actual, Nam);
3118 -- Normalize_Actuals has verified that a default value exists
3119 -- for this formal. Current actual names a subsequent formal.
3121 Next_Formal (Formal);
3125 -- On exit, all actuals match
3127 Indicate_Name_And_Type;
3129 end Analyze_One_Call;
3131 ---------------------------
3132 -- Analyze_Operator_Call --
3133 ---------------------------
3135 procedure Analyze_Operator_Call (N : Node_Id; Op_Id : Entity_Id) is
3136 Op_Name : constant Name_Id := Chars (Op_Id);
3137 Act1 : constant Node_Id := First_Actual (N);
3138 Act2 : constant Node_Id := Next_Actual (Act1);
3141 -- Binary operator case
3143 if Present (Act2) then
3145 -- If more than two operands, then not binary operator after all
3147 if Present (Next_Actual (Act2)) then
3151 -- Otherwise action depends on operator
3161 Find_Arithmetic_Types (Act1, Act2, Op_Id, N);
3166 Find_Boolean_Types (Act1, Act2, Op_Id, N);
3172 Find_Comparison_Types (Act1, Act2, Op_Id, N);
3176 Find_Equality_Types (Act1, Act2, Op_Id, N);
3178 when Name_Op_Concat =>
3179 Find_Concatenation_Types (Act1, Act2, Op_Id, N);
3181 -- Is this when others, or should it be an abort???
3187 -- Unary operator case
3191 when Name_Op_Subtract |
3194 Find_Unary_Types (Act1, Op_Id, N);
3197 Find_Negation_Types (Act1, Op_Id, N);
3199 -- Is this when others correct, or should it be an abort???
3205 end Analyze_Operator_Call;
3207 -------------------------------------------
3208 -- Analyze_Overloaded_Selected_Component --
3209 -------------------------------------------
3211 procedure Analyze_Overloaded_Selected_Component (N : Node_Id) is
3212 Nam : constant Node_Id := Prefix (N);
3213 Sel : constant Node_Id := Selector_Name (N);
3220 Set_Etype (Sel, Any_Type);
3222 Get_First_Interp (Nam, I, It);
3223 while Present (It.Typ) loop
3224 if Is_Access_Type (It.Typ) then
3225 T := Designated_Type (It.Typ);
3226 Error_Msg_NW (Warn_On_Dereference, "?implicit dereference", N);
3231 -- Locate the component. For a private prefix the selector can denote
3234 if Is_Record_Type (T) or else Is_Private_Type (T) then
3236 -- If the prefix is a class-wide type, the visible components are
3237 -- those of the base type.
3239 if Is_Class_Wide_Type (T) then
3243 Comp := First_Entity (T);
3244 while Present (Comp) loop
3245 if Chars (Comp) = Chars (Sel)
3246 and then Is_Visible_Component (Comp)
3249 -- AI05-105: if the context is an object renaming with
3250 -- an anonymous access type, the expected type of the
3251 -- object must be anonymous. This is a name resolution rule.
3253 if Nkind (Parent (N)) /= N_Object_Renaming_Declaration
3254 or else No (Access_Definition (Parent (N)))
3255 or else Ekind (Etype (Comp)) = E_Anonymous_Access_Type
3257 Ekind (Etype (Comp)) = E_Anonymous_Access_Subprogram_Type
3259 Set_Entity (Sel, Comp);
3260 Set_Etype (Sel, Etype (Comp));
3261 Add_One_Interp (N, Etype (Comp), Etype (Comp));
3262 Check_Implicit_Dereference (N, Etype (Comp));
3264 -- This also specifies a candidate to resolve the name.
3265 -- Further overloading will be resolved from context.
3266 -- The selector name itself does not carry overloading
3269 Set_Etype (Nam, It.Typ);
3272 -- Named access type in the context of a renaming
3273 -- declaration with an access definition. Remove
3274 -- inapplicable candidate.
3283 elsif Is_Concurrent_Type (T) then
3284 Comp := First_Entity (T);
3285 while Present (Comp)
3286 and then Comp /= First_Private_Entity (T)
3288 if Chars (Comp) = Chars (Sel) then
3289 if Is_Overloadable (Comp) then
3290 Add_One_Interp (Sel, Comp, Etype (Comp));
3292 Set_Entity_With_Style_Check (Sel, Comp);
3293 Generate_Reference (Comp, Sel);
3296 Set_Etype (Sel, Etype (Comp));
3297 Set_Etype (N, Etype (Comp));
3298 Set_Etype (Nam, It.Typ);
3300 -- For access type case, introduce explicit dereference for
3301 -- more uniform treatment of entry calls. Do this only once
3302 -- if several interpretations yield an access type.
3304 if Is_Access_Type (Etype (Nam))
3305 and then Nkind (Nam) /= N_Explicit_Dereference
3307 Insert_Explicit_Dereference (Nam);
3309 (Warn_On_Dereference, "?implicit dereference", N);
3316 Set_Is_Overloaded (N, Is_Overloaded (Sel));
3319 Get_Next_Interp (I, It);
3322 if Etype (N) = Any_Type
3323 and then not Try_Object_Operation (N)
3325 Error_Msg_NE ("undefined selector& for overloaded prefix", N, Sel);
3326 Set_Entity (Sel, Any_Id);
3327 Set_Etype (Sel, Any_Type);
3329 end Analyze_Overloaded_Selected_Component;
3331 ----------------------------------
3332 -- Analyze_Qualified_Expression --
3333 ----------------------------------
3335 procedure Analyze_Qualified_Expression (N : Node_Id) is
3336 Mark : constant Entity_Id := Subtype_Mark (N);
3337 Expr : constant Node_Id := Expression (N);
3343 Analyze_Expression (Expr);
3345 Set_Etype (N, Any_Type);
3350 if T = Any_Type then
3354 Check_Fully_Declared (T, N);
3356 -- If expected type is class-wide, check for exact match before
3357 -- expansion, because if the expression is a dispatching call it
3358 -- may be rewritten as explicit dereference with class-wide result.
3359 -- If expression is overloaded, retain only interpretations that
3360 -- will yield exact matches.
3362 if Is_Class_Wide_Type (T) then
3363 if not Is_Overloaded (Expr) then
3364 if Base_Type (Etype (Expr)) /= Base_Type (T) then
3365 if Nkind (Expr) = N_Aggregate then
3366 Error_Msg_N ("type of aggregate cannot be class-wide", Expr);
3368 Wrong_Type (Expr, T);
3373 Get_First_Interp (Expr, I, It);
3375 while Present (It.Nam) loop
3376 if Base_Type (It.Typ) /= Base_Type (T) then
3380 Get_Next_Interp (I, It);
3386 end Analyze_Qualified_Expression;
3388 -----------------------------------
3389 -- Analyze_Quantified_Expression --
3390 -----------------------------------
3392 procedure Analyze_Quantified_Expression (N : Node_Id) is
3393 Loc : constant Source_Ptr := Sloc (N);
3394 Ent : constant Entity_Id :=
3396 (E_Loop, Current_Scope, Sloc (N), 'L');
3401 Set_Etype (Ent, Standard_Void_Type);
3402 Set_Scope (Ent, Current_Scope);
3403 Set_Parent (Ent, N);
3405 Check_SPARK_Restriction ("quantified expression is not allowed", N);
3407 -- If expansion is enabled (and not in Alfa mode), the condition is
3408 -- analyzed after rewritten as a loop. So we only need to set the type.
3410 if Operating_Mode /= Check_Semantics
3411 and then not Alfa_Mode
3413 Set_Etype (N, Standard_Boolean);
3417 if Present (Loop_Parameter_Specification (N)) then
3419 Make_Iteration_Scheme (Loc,
3420 Loop_Parameter_Specification =>
3421 Loop_Parameter_Specification (N));
3424 Make_Iteration_Scheme (Loc,
3425 Iterator_Specification =>
3426 Iterator_Specification (N));
3430 Set_Parent (Iterator, N);
3431 Analyze_Iteration_Scheme (Iterator);
3433 -- The loop specification may have been converted into an iterator
3434 -- specification during its analysis. Update the quantified node
3437 if Present (Iterator_Specification (Iterator)) then
3438 Set_Iterator_Specification
3439 (N, Iterator_Specification (Iterator));
3440 Set_Loop_Parameter_Specification (N, Empty);
3443 Analyze (Condition (N));
3445 Set_Etype (N, Standard_Boolean);
3446 end Analyze_Quantified_Expression;
3452 procedure Analyze_Range (N : Node_Id) is
3453 L : constant Node_Id := Low_Bound (N);
3454 H : constant Node_Id := High_Bound (N);
3455 I1, I2 : Interp_Index;
3458 procedure Check_Common_Type (T1, T2 : Entity_Id);
3459 -- Verify the compatibility of two types, and choose the
3460 -- non universal one if the other is universal.
3462 procedure Check_High_Bound (T : Entity_Id);
3463 -- Test one interpretation of the low bound against all those
3464 -- of the high bound.
3466 procedure Check_Universal_Expression (N : Node_Id);
3467 -- In Ada 83, reject bounds of a universal range that are not literals
3470 -----------------------
3471 -- Check_Common_Type --
3472 -----------------------
3474 procedure Check_Common_Type (T1, T2 : Entity_Id) is
3476 if Covers (T1 => T1, T2 => T2)
3478 Covers (T1 => T2, T2 => T1)
3480 if T1 = Universal_Integer
3481 or else T1 = Universal_Real
3482 or else T1 = Any_Character
3484 Add_One_Interp (N, Base_Type (T2), Base_Type (T2));
3487 Add_One_Interp (N, T1, T1);
3490 Add_One_Interp (N, Base_Type (T1), Base_Type (T1));
3493 end Check_Common_Type;
3495 ----------------------
3496 -- Check_High_Bound --
3497 ----------------------
3499 procedure Check_High_Bound (T : Entity_Id) is
3501 if not Is_Overloaded (H) then
3502 Check_Common_Type (T, Etype (H));
3504 Get_First_Interp (H, I2, It2);
3505 while Present (It2.Typ) loop
3506 Check_Common_Type (T, It2.Typ);
3507 Get_Next_Interp (I2, It2);
3510 end Check_High_Bound;
3512 -----------------------------
3513 -- Is_Universal_Expression --
3514 -----------------------------
3516 procedure Check_Universal_Expression (N : Node_Id) is
3518 if Etype (N) = Universal_Integer
3519 and then Nkind (N) /= N_Integer_Literal
3520 and then not Is_Entity_Name (N)
3521 and then Nkind (N) /= N_Attribute_Reference
3523 Error_Msg_N ("illegal bound in discrete range", N);
3525 end Check_Universal_Expression;
3527 -- Start of processing for Analyze_Range
3530 Set_Etype (N, Any_Type);
3531 Analyze_Expression (L);
3532 Analyze_Expression (H);
3534 if Etype (L) = Any_Type or else Etype (H) = Any_Type then
3538 if not Is_Overloaded (L) then
3539 Check_High_Bound (Etype (L));
3541 Get_First_Interp (L, I1, It1);
3542 while Present (It1.Typ) loop
3543 Check_High_Bound (It1.Typ);
3544 Get_Next_Interp (I1, It1);
3548 -- If result is Any_Type, then we did not find a compatible pair
3550 if Etype (N) = Any_Type then
3551 Error_Msg_N ("incompatible types in range ", N);
3555 if Ada_Version = Ada_83
3557 (Nkind (Parent (N)) = N_Loop_Parameter_Specification
3558 or else Nkind (Parent (N)) = N_Constrained_Array_Definition)
3560 Check_Universal_Expression (L);
3561 Check_Universal_Expression (H);
3565 -----------------------
3566 -- Analyze_Reference --
3567 -----------------------
3569 procedure Analyze_Reference (N : Node_Id) is
3570 P : constant Node_Id := Prefix (N);
3573 Acc_Type : Entity_Id;
3578 -- An interesting error check, if we take the 'Reference of an object
3579 -- for which a pragma Atomic or Volatile has been given, and the type
3580 -- of the object is not Atomic or Volatile, then we are in trouble. The
3581 -- problem is that no trace of the atomic/volatile status will remain
3582 -- for the backend to respect when it deals with the resulting pointer,
3583 -- since the pointer type will not be marked atomic (it is a pointer to
3584 -- the base type of the object).
3586 -- It is not clear if that can ever occur, but in case it does, we will
3587 -- generate an error message. Not clear if this message can ever be
3588 -- generated, and pretty clear that it represents a bug if it is, still
3589 -- seems worth checking, except in CodePeer mode where we do not really
3590 -- care and don't want to bother the user.
3594 if Is_Entity_Name (P)
3595 and then Is_Object_Reference (P)
3596 and then not CodePeer_Mode
3601 if (Has_Atomic_Components (E)
3602 and then not Has_Atomic_Components (T))
3604 (Has_Volatile_Components (E)
3605 and then not Has_Volatile_Components (T))
3606 or else (Is_Atomic (E) and then not Is_Atomic (T))
3607 or else (Is_Volatile (E) and then not Is_Volatile (T))
3609 Error_Msg_N ("cannot take reference to Atomic/Volatile object", N);
3613 -- Carry on with normal processing
3615 Acc_Type := Create_Itype (E_Allocator_Type, N);
3616 Set_Etype (Acc_Type, Acc_Type);
3617 Set_Directly_Designated_Type (Acc_Type, Etype (P));
3618 Set_Etype (N, Acc_Type);
3619 end Analyze_Reference;
3621 --------------------------------
3622 -- Analyze_Selected_Component --
3623 --------------------------------
3625 -- Prefix is a record type or a task or protected type. In the latter case,
3626 -- the selector must denote a visible entry.
3628 procedure Analyze_Selected_Component (N : Node_Id) is
3629 Name : constant Node_Id := Prefix (N);
3630 Sel : constant Node_Id := Selector_Name (N);
3633 Has_Candidate : Boolean := False;
3636 Pent : Entity_Id := Empty;
3637 Prefix_Type : Entity_Id;
3639 Type_To_Use : Entity_Id;
3640 -- In most cases this is the Prefix_Type, but if the Prefix_Type is
3641 -- a class-wide type, we use its root type, whose components are
3642 -- present in the class-wide type.
3644 Is_Single_Concurrent_Object : Boolean;
3645 -- Set True if the prefix is a single task or a single protected object
3647 procedure Find_Component_In_Instance (Rec : Entity_Id);
3648 -- In an instance, a component of a private extension may not be visible
3649 -- while it was visible in the generic. Search candidate scope for a
3650 -- component with the proper identifier. This is only done if all other
3651 -- searches have failed. When the match is found (it always will be),
3652 -- the Etype of both N and Sel are set from this component, and the
3653 -- entity of Sel is set to reference this component.
3655 function Has_Mode_Conformant_Spec (Comp : Entity_Id) return Boolean;
3656 -- It is known that the parent of N denotes a subprogram call. Comp
3657 -- is an overloadable component of the concurrent type of the prefix.
3658 -- Determine whether all formals of the parent of N and Comp are mode
3659 -- conformant. If the parent node is not analyzed yet it may be an
3660 -- indexed component rather than a function call.
3662 --------------------------------
3663 -- Find_Component_In_Instance --
3664 --------------------------------
3666 procedure Find_Component_In_Instance (Rec : Entity_Id) is
3670 Comp := First_Component (Rec);
3671 while Present (Comp) loop
3672 if Chars (Comp) = Chars (Sel) then
3673 Set_Entity_With_Style_Check (Sel, Comp);
3674 Set_Etype (Sel, Etype (Comp));
3675 Set_Etype (N, Etype (Comp));
3679 Next_Component (Comp);
3682 -- This must succeed because code was legal in the generic
3684 raise Program_Error;
3685 end Find_Component_In_Instance;
3687 ------------------------------
3688 -- Has_Mode_Conformant_Spec --
3689 ------------------------------
3691 function Has_Mode_Conformant_Spec (Comp : Entity_Id) return Boolean is
3692 Comp_Param : Entity_Id;
3694 Param_Typ : Entity_Id;
3697 Comp_Param := First_Formal (Comp);
3699 if Nkind (Parent (N)) = N_Indexed_Component then
3700 Param := First (Expressions (Parent (N)));
3702 Param := First (Parameter_Associations (Parent (N)));
3705 while Present (Comp_Param)
3706 and then Present (Param)
3708 Param_Typ := Find_Parameter_Type (Param);
3710 if Present (Param_Typ)
3712 not Conforming_Types
3713 (Etype (Comp_Param), Param_Typ, Mode_Conformant)
3718 Next_Formal (Comp_Param);
3722 -- One of the specs has additional formals
3724 if Present (Comp_Param) or else Present (Param) then
3729 end Has_Mode_Conformant_Spec;
3731 -- Start of processing for Analyze_Selected_Component
3734 Set_Etype (N, Any_Type);
3736 if Is_Overloaded (Name) then
3737 Analyze_Overloaded_Selected_Component (N);
3740 elsif Etype (Name) = Any_Type then
3741 Set_Entity (Sel, Any_Id);
3742 Set_Etype (Sel, Any_Type);
3746 Prefix_Type := Etype (Name);
3749 if Is_Access_Type (Prefix_Type) then
3751 -- A RACW object can never be used as prefix of a selected component
3752 -- since that means it is dereferenced without being a controlling
3753 -- operand of a dispatching operation (RM E.2.2(16/1)). Before
3754 -- reporting an error, we must check whether this is actually a
3755 -- dispatching call in prefix form.
3757 if Is_Remote_Access_To_Class_Wide_Type (Prefix_Type)
3758 and then Comes_From_Source (N)
3760 if Try_Object_Operation (N) then
3764 ("invalid dereference of a remote access-to-class-wide value",
3768 -- Normal case of selected component applied to access type
3771 Error_Msg_NW (Warn_On_Dereference, "?implicit dereference", N);
3773 if Is_Entity_Name (Name) then
3774 Pent := Entity (Name);
3775 elsif Nkind (Name) = N_Selected_Component
3776 and then Is_Entity_Name (Selector_Name (Name))
3778 Pent := Entity (Selector_Name (Name));
3781 Prefix_Type := Process_Implicit_Dereference_Prefix (Pent, Name);
3784 -- If we have an explicit dereference of a remote access-to-class-wide
3785 -- value, then issue an error (see RM-E.2.2(16/1)). However we first
3786 -- have to check for the case of a prefix that is a controlling operand
3787 -- of a prefixed dispatching call, as the dereference is legal in that
3788 -- case. Normally this condition is checked in Validate_Remote_Access_
3789 -- To_Class_Wide_Type, but we have to defer the checking for selected
3790 -- component prefixes because of the prefixed dispatching call case.
3791 -- Note that implicit dereferences are checked for this just above.
3793 elsif Nkind (Name) = N_Explicit_Dereference
3794 and then Is_Remote_Access_To_Class_Wide_Type (Etype (Prefix (Name)))
3795 and then Comes_From_Source (N)
3797 if Try_Object_Operation (N) then
3801 ("invalid dereference of a remote access-to-class-wide value",
3806 -- (Ada 2005): if the prefix is the limited view of a type, and
3807 -- the context already includes the full view, use the full view
3808 -- in what follows, either to retrieve a component of to find
3809 -- a primitive operation. If the prefix is an explicit dereference,
3810 -- set the type of the prefix to reflect this transformation.
3811 -- If the non-limited view is itself an incomplete type, get the
3812 -- full view if available.
3814 if Is_Incomplete_Type (Prefix_Type)
3815 and then From_With_Type (Prefix_Type)
3816 and then Present (Non_Limited_View (Prefix_Type))
3818 Prefix_Type := Get_Full_View (Non_Limited_View (Prefix_Type));
3820 if Nkind (N) = N_Explicit_Dereference then
3821 Set_Etype (Prefix (N), Prefix_Type);
3824 elsif Ekind (Prefix_Type) = E_Class_Wide_Type
3825 and then From_With_Type (Prefix_Type)
3826 and then Present (Non_Limited_View (Etype (Prefix_Type)))
3829 Class_Wide_Type (Non_Limited_View (Etype (Prefix_Type)));
3831 if Nkind (N) = N_Explicit_Dereference then
3832 Set_Etype (Prefix (N), Prefix_Type);
3836 if Ekind (Prefix_Type) = E_Private_Subtype then
3837 Prefix_Type := Base_Type (Prefix_Type);
3840 Type_To_Use := Prefix_Type;
3842 -- For class-wide types, use the entity list of the root type. This
3843 -- indirection is specially important for private extensions because
3844 -- only the root type get switched (not the class-wide type).
3846 if Is_Class_Wide_Type (Prefix_Type) then
3847 Type_To_Use := Root_Type (Prefix_Type);
3850 -- If the prefix is a single concurrent object, use its name in error
3851 -- messages, rather than that of its anonymous type.
3853 Is_Single_Concurrent_Object :=
3854 Is_Concurrent_Type (Prefix_Type)
3855 and then Is_Internal_Name (Chars (Prefix_Type))
3856 and then not Is_Derived_Type (Prefix_Type)
3857 and then Is_Entity_Name (Name);
3859 Comp := First_Entity (Type_To_Use);
3861 -- If the selector has an original discriminant, the node appears in
3862 -- an instance. Replace the discriminant with the corresponding one
3863 -- in the current discriminated type. For nested generics, this must
3864 -- be done transitively, so note the new original discriminant.
3866 if Nkind (Sel) = N_Identifier
3867 and then In_Instance
3868 and then Present (Original_Discriminant (Sel))
3870 Comp := Find_Corresponding_Discriminant (Sel, Prefix_Type);
3872 -- Mark entity before rewriting, for completeness and because
3873 -- subsequent semantic checks might examine the original node.
3875 Set_Entity (Sel, Comp);
3876 Rewrite (Selector_Name (N),
3877 New_Occurrence_Of (Comp, Sloc (N)));
3878 Set_Original_Discriminant (Selector_Name (N), Comp);
3879 Set_Etype (N, Etype (Comp));
3880 Check_Implicit_Dereference (N, Etype (Comp));
3882 if Is_Access_Type (Etype (Name)) then
3883 Insert_Explicit_Dereference (Name);
3884 Error_Msg_NW (Warn_On_Dereference, "?implicit dereference", N);
3887 elsif Is_Record_Type (Prefix_Type) then
3889 -- Find component with given name
3890 -- In an instance, if the node is known as a prefixed call, do
3891 -- not examine components whose visibility may be accidental.
3893 while Present (Comp) and then not Is_Prefixed_Call (N) loop
3894 if Chars (Comp) = Chars (Sel)
3895 and then Is_Visible_Component (Comp)
3897 Set_Entity_With_Style_Check (Sel, Comp);
3898 Set_Etype (Sel, Etype (Comp));
3900 if Ekind (Comp) = E_Discriminant then
3901 if Is_Unchecked_Union (Base_Type (Prefix_Type)) then
3903 ("cannot reference discriminant of Unchecked_Union",
3907 if Is_Generic_Type (Prefix_Type)
3909 Is_Generic_Type (Root_Type (Prefix_Type))
3911 Set_Original_Discriminant (Sel, Comp);
3915 -- Resolve the prefix early otherwise it is not possible to
3916 -- build the actual subtype of the component: it may need
3917 -- to duplicate this prefix and duplication is only allowed
3918 -- on fully resolved expressions.
3922 -- Ada 2005 (AI-50217): Check wrong use of incomplete types or
3923 -- subtypes in a package specification.
3926 -- limited with Pkg;
3928 -- type Acc_Inc is access Pkg.T;
3930 -- N : Natural := X.all.Comp; -- ERROR, limited view
3931 -- end Pkg; -- Comp is not visible
3933 if Nkind (Name) = N_Explicit_Dereference
3934 and then From_With_Type (Etype (Prefix (Name)))
3935 and then not Is_Potentially_Use_Visible (Etype (Name))
3936 and then Nkind (Parent (Cunit_Entity (Current_Sem_Unit))) =
3937 N_Package_Specification
3940 ("premature usage of incomplete}", Prefix (Name),
3941 Etype (Prefix (Name)));
3944 -- We never need an actual subtype for the case of a selection
3945 -- for a indexed component of a non-packed array, since in
3946 -- this case gigi generates all the checks and can find the
3947 -- necessary bounds information.
3949 -- We also do not need an actual subtype for the case of a
3950 -- first, last, length, or range attribute applied to a
3951 -- non-packed array, since gigi can again get the bounds in
3952 -- these cases (gigi cannot handle the packed case, since it
3953 -- has the bounds of the packed array type, not the original
3954 -- bounds of the type). However, if the prefix is itself a
3955 -- selected component, as in a.b.c (i), gigi may regard a.b.c
3956 -- as a dynamic-sized temporary, so we do generate an actual
3957 -- subtype for this case.
3959 Parent_N := Parent (N);
3961 if not Is_Packed (Etype (Comp))
3963 ((Nkind (Parent_N) = N_Indexed_Component
3964 and then Nkind (Name) /= N_Selected_Component)
3966 (Nkind (Parent_N) = N_Attribute_Reference
3967 and then (Attribute_Name (Parent_N) = Name_First
3969 Attribute_Name (Parent_N) = Name_Last
3971 Attribute_Name (Parent_N) = Name_Length
3973 Attribute_Name (Parent_N) = Name_Range)))
3975 Set_Etype (N, Etype (Comp));
3977 -- If full analysis is not enabled, we do not generate an
3978 -- actual subtype, because in the absence of expansion
3979 -- reference to a formal of a protected type, for example,
3980 -- will not be properly transformed, and will lead to
3981 -- out-of-scope references in gigi.
3983 -- In all other cases, we currently build an actual subtype.
3984 -- It seems likely that many of these cases can be avoided,
3985 -- but right now, the front end makes direct references to the
3986 -- bounds (e.g. in generating a length check), and if we do
3987 -- not make an actual subtype, we end up getting a direct
3988 -- reference to a discriminant, which will not do.
3990 elsif Full_Analysis then
3992 Build_Actual_Subtype_Of_Component (Etype (Comp), N);
3993 Insert_Action (N, Act_Decl);
3995 if No (Act_Decl) then
3996 Set_Etype (N, Etype (Comp));
3999 -- Component type depends on discriminants. Enter the
4000 -- main attributes of the subtype.
4003 Subt : constant Entity_Id :=
4004 Defining_Identifier (Act_Decl);
4007 Set_Etype (Subt, Base_Type (Etype (Comp)));
4008 Set_Ekind (Subt, Ekind (Etype (Comp)));
4009 Set_Etype (N, Subt);
4013 -- If Full_Analysis not enabled, just set the Etype
4016 Set_Etype (N, Etype (Comp));
4019 Check_Implicit_Dereference (N, Etype (N));
4023 -- If the prefix is a private extension, check only the visible
4024 -- components of the partial view. This must include the tag,
4025 -- which can appear in expanded code in a tag check.
4027 if Ekind (Type_To_Use) = E_Record_Type_With_Private
4028 and then Chars (Selector_Name (N)) /= Name_uTag
4030 exit when Comp = Last_Entity (Type_To_Use);
4036 -- Ada 2005 (AI-252): The selected component can be interpreted as
4037 -- a prefixed view of a subprogram. Depending on the context, this is
4038 -- either a name that can appear in a renaming declaration, or part
4039 -- of an enclosing call given in prefix form.
4041 -- Ada 2005 (AI05-0030): In the case of dispatching requeue, the
4042 -- selected component should resolve to a name.
4044 if Ada_Version >= Ada_2005
4045 and then Is_Tagged_Type (Prefix_Type)
4046 and then not Is_Concurrent_Type (Prefix_Type)
4048 if Nkind (Parent (N)) = N_Generic_Association
4049 or else Nkind (Parent (N)) = N_Requeue_Statement
4050 or else Nkind (Parent (N)) = N_Subprogram_Renaming_Declaration
4052 if Find_Primitive_Operation (N) then
4056 elsif Try_Object_Operation (N) then
4060 -- If the transformation fails, it will be necessary to redo the
4061 -- analysis with all errors enabled, to indicate candidate
4062 -- interpretations and reasons for each failure ???
4066 elsif Is_Private_Type (Prefix_Type) then
4068 -- Allow access only to discriminants of the type. If the type has
4069 -- no full view, gigi uses the parent type for the components, so we
4070 -- do the same here.
4072 if No (Full_View (Prefix_Type)) then
4073 Type_To_Use := Root_Type (Base_Type (Prefix_Type));
4074 Comp := First_Entity (Type_To_Use);
4077 while Present (Comp) loop
4078 if Chars (Comp) = Chars (Sel) then
4079 if Ekind (Comp) = E_Discriminant then
4080 Set_Entity_With_Style_Check (Sel, Comp);
4081 Generate_Reference (Comp, Sel);
4083 Set_Etype (Sel, Etype (Comp));
4084 Set_Etype (N, Etype (Comp));
4085 Check_Implicit_Dereference (N, Etype (N));
4087 if Is_Generic_Type (Prefix_Type)
4088 or else Is_Generic_Type (Root_Type (Prefix_Type))
4090 Set_Original_Discriminant (Sel, Comp);
4093 -- Before declaring an error, check whether this is tagged
4094 -- private type and a call to a primitive operation.
4096 elsif Ada_Version >= Ada_2005
4097 and then Is_Tagged_Type (Prefix_Type)
4098 and then Try_Object_Operation (N)
4103 Error_Msg_Node_2 := First_Subtype (Prefix_Type);
4104 Error_Msg_NE ("invisible selector& for }", N, Sel);
4105 Set_Entity (Sel, Any_Id);
4106 Set_Etype (N, Any_Type);
4115 elsif Is_Concurrent_Type (Prefix_Type) then
4117 -- Find visible operation with given name. For a protected type,
4118 -- the possible candidates are discriminants, entries or protected
4119 -- procedures. For a task type, the set can only include entries or
4120 -- discriminants if the task type is not an enclosing scope. If it
4121 -- is an enclosing scope (e.g. in an inner task) then all entities
4122 -- are visible, but the prefix must denote the enclosing scope, i.e.
4123 -- can only be a direct name or an expanded name.
4125 Set_Etype (Sel, Any_Type);
4126 In_Scope := In_Open_Scopes (Prefix_Type);
4128 while Present (Comp) loop
4129 if Chars (Comp) = Chars (Sel) then
4130 if Is_Overloadable (Comp) then
4131 Add_One_Interp (Sel, Comp, Etype (Comp));
4133 -- If the prefix is tagged, the correct interpretation may
4134 -- lie in the primitive or class-wide operations of the
4135 -- type. Perform a simple conformance check to determine
4136 -- whether Try_Object_Operation should be invoked even if
4137 -- a visible entity is found.
4139 if Is_Tagged_Type (Prefix_Type)
4141 Nkind_In (Parent (N), N_Procedure_Call_Statement,
4143 N_Indexed_Component)
4144 and then Has_Mode_Conformant_Spec (Comp)
4146 Has_Candidate := True;
4149 -- Note: a selected component may not denote a component of a
4150 -- protected type (4.1.3(7)).
4152 elsif Ekind_In (Comp, E_Discriminant, E_Entry_Family)
4154 and then not Is_Protected_Type (Prefix_Type)
4155 and then Is_Entity_Name (Name))
4157 Set_Entity_With_Style_Check (Sel, Comp);
4158 Generate_Reference (Comp, Sel);
4160 -- The selector is not overloadable, so we have a candidate
4163 Has_Candidate := True;
4169 Set_Etype (Sel, Etype (Comp));
4170 Set_Etype (N, Etype (Comp));
4172 if Ekind (Comp) = E_Discriminant then
4173 Set_Original_Discriminant (Sel, Comp);
4176 -- For access type case, introduce explicit dereference for
4177 -- more uniform treatment of entry calls.
4179 if Is_Access_Type (Etype (Name)) then
4180 Insert_Explicit_Dereference (Name);
4182 (Warn_On_Dereference, "?implicit dereference", N);
4188 exit when not In_Scope
4190 Comp = First_Private_Entity (Base_Type (Prefix_Type));
4193 -- If there is no visible entity with the given name or none of the
4194 -- visible entities are plausible interpretations, check whether
4195 -- there is some other primitive operation with that name.
4197 if Ada_Version >= Ada_2005
4198 and then Is_Tagged_Type (Prefix_Type)
4200 if (Etype (N) = Any_Type
4201 or else not Has_Candidate)
4202 and then Try_Object_Operation (N)
4206 -- If the context is not syntactically a procedure call, it
4207 -- may be a call to a primitive function declared outside of
4208 -- the synchronized type.
4210 -- If the context is a procedure call, there might still be
4211 -- an overloading between an entry and a primitive procedure
4212 -- declared outside of the synchronized type, called in prefix
4213 -- notation. This is harder to disambiguate because in one case
4214 -- the controlling formal is implicit ???
4216 elsif Nkind (Parent (N)) /= N_Procedure_Call_Statement
4217 and then Nkind (Parent (N)) /= N_Indexed_Component
4218 and then Try_Object_Operation (N)
4223 -- Ada 2012 (AI05-0090-1): If we found a candidate of a call to an
4224 -- entry or procedure of a tagged concurrent type we must check
4225 -- if there are class-wide subprograms covering the primitive. If
4226 -- true then Try_Object_Operation reports the error.
4229 and then Is_Concurrent_Type (Prefix_Type)
4230 and then Nkind (Parent (N)) = N_Procedure_Call_Statement
4232 -- Duplicate the call. This is required to avoid problems with
4233 -- the tree transformations performed by Try_Object_Operation.
4236 Try_Object_Operation
4237 (N => Sinfo.Name (New_Copy_Tree (Parent (N))),
4238 CW_Test_Only => True)
4244 if Etype (N) = Any_Type and then Is_Protected_Type (Prefix_Type) then
4246 -- Case of a prefix of a protected type: selector might denote
4247 -- an invisible private component.
4249 Comp := First_Private_Entity (Base_Type (Prefix_Type));
4250 while Present (Comp) and then Chars (Comp) /= Chars (Sel) loop
4254 if Present (Comp) then
4255 if Is_Single_Concurrent_Object then
4256 Error_Msg_Node_2 := Entity (Name);
4257 Error_Msg_NE ("invisible selector& for &", N, Sel);
4260 Error_Msg_Node_2 := First_Subtype (Prefix_Type);
4261 Error_Msg_NE ("invisible selector& for }", N, Sel);
4267 Set_Is_Overloaded (N, Is_Overloaded (Sel));
4272 Error_Msg_NE ("invalid prefix in selected component&", N, Sel);
4275 -- If N still has no type, the component is not defined in the prefix
4277 if Etype (N) = Any_Type then
4279 if Is_Single_Concurrent_Object then
4280 Error_Msg_Node_2 := Entity (Name);
4281 Error_Msg_NE ("no selector& for&", N, Sel);
4283 Check_Misspelled_Selector (Type_To_Use, Sel);
4285 elsif Is_Generic_Type (Prefix_Type)
4286 and then Ekind (Prefix_Type) = E_Record_Type_With_Private
4287 and then Prefix_Type /= Etype (Prefix_Type)
4288 and then Is_Record_Type (Etype (Prefix_Type))
4290 -- If this is a derived formal type, the parent may have
4291 -- different visibility at this point. Try for an inherited
4292 -- component before reporting an error.
4294 Set_Etype (Prefix (N), Etype (Prefix_Type));
4295 Analyze_Selected_Component (N);
4298 -- Similarly, if this is the actual for a formal derived type, the
4299 -- component inherited from the generic parent may not be visible
4300 -- in the actual, but the selected component is legal.
4302 elsif Ekind (Prefix_Type) = E_Record_Subtype_With_Private
4303 and then Is_Generic_Actual_Type (Prefix_Type)
4304 and then Present (Full_View (Prefix_Type))
4307 Find_Component_In_Instance
4308 (Generic_Parent_Type (Parent (Prefix_Type)));
4311 -- Finally, the formal and the actual may be private extensions,
4312 -- but the generic is declared in a child unit of the parent, and
4313 -- an additional step is needed to retrieve the proper scope.
4316 and then Present (Parent_Subtype (Etype (Base_Type (Prefix_Type))))
4318 Find_Component_In_Instance
4319 (Parent_Subtype (Etype (Base_Type (Prefix_Type))));
4322 -- Component not found, specialize error message when appropriate
4325 if Ekind (Prefix_Type) = E_Record_Subtype then
4327 -- Check whether this is a component of the base type which
4328 -- is absent from a statically constrained subtype. This will
4329 -- raise constraint error at run time, but is not a compile-
4330 -- time error. When the selector is illegal for base type as
4331 -- well fall through and generate a compilation error anyway.
4333 Comp := First_Component (Base_Type (Prefix_Type));
4334 while Present (Comp) loop
4335 if Chars (Comp) = Chars (Sel)
4336 and then Is_Visible_Component (Comp)
4338 Set_Entity_With_Style_Check (Sel, Comp);
4339 Generate_Reference (Comp, Sel);
4340 Set_Etype (Sel, Etype (Comp));
4341 Set_Etype (N, Etype (Comp));
4343 -- Emit appropriate message. Gigi will replace the
4344 -- node subsequently with the appropriate Raise.
4346 Apply_Compile_Time_Constraint_Error
4347 (N, "component not present in }?",
4348 CE_Discriminant_Check_Failed,
4349 Ent => Prefix_Type, Rep => False);
4350 Set_Raises_Constraint_Error (N);
4354 Next_Component (Comp);
4359 Error_Msg_Node_2 := First_Subtype (Prefix_Type);
4360 Error_Msg_NE ("no selector& for}", N, Sel);
4362 -- Add information in the case of an incomplete prefix
4364 if Is_Incomplete_Type (Type_To_Use) then
4366 Inc : constant Entity_Id := First_Subtype (Type_To_Use);
4369 if From_With_Type (Scope (Type_To_Use)) then
4371 ("\limited view of& has no components", N, Inc);
4375 ("\premature usage of incomplete type&", N, Inc);
4377 if Nkind (Parent (Inc)) =
4378 N_Incomplete_Type_Declaration
4380 -- Record location of premature use in entity so that
4381 -- a continuation message is generated when the
4382 -- completion is seen.
4384 Set_Premature_Use (Parent (Inc), N);
4390 Check_Misspelled_Selector (Type_To_Use, Sel);
4393 Set_Entity (Sel, Any_Id);
4394 Set_Etype (Sel, Any_Type);
4396 end Analyze_Selected_Component;
4398 ---------------------------
4399 -- Analyze_Short_Circuit --
4400 ---------------------------
4402 procedure Analyze_Short_Circuit (N : Node_Id) is
4403 L : constant Node_Id := Left_Opnd (N);
4404 R : constant Node_Id := Right_Opnd (N);
4409 Analyze_Expression (L);
4410 Analyze_Expression (R);
4411 Set_Etype (N, Any_Type);
4413 if not Is_Overloaded (L) then
4414 if Root_Type (Etype (L)) = Standard_Boolean
4415 and then Has_Compatible_Type (R, Etype (L))
4417 Add_One_Interp (N, Etype (L), Etype (L));
4421 Get_First_Interp (L, Ind, It);
4422 while Present (It.Typ) loop
4423 if Root_Type (It.Typ) = Standard_Boolean
4424 and then Has_Compatible_Type (R, It.Typ)
4426 Add_One_Interp (N, It.Typ, It.Typ);
4429 Get_Next_Interp (Ind, It);
4433 -- Here we have failed to find an interpretation. Clearly we know that
4434 -- it is not the case that both operands can have an interpretation of
4435 -- Boolean, but this is by far the most likely intended interpretation.
4436 -- So we simply resolve both operands as Booleans, and at least one of
4437 -- these resolutions will generate an error message, and we do not need
4438 -- to give another error message on the short circuit operation itself.
4440 if Etype (N) = Any_Type then
4441 Resolve (L, Standard_Boolean);
4442 Resolve (R, Standard_Boolean);
4443 Set_Etype (N, Standard_Boolean);
4445 end Analyze_Short_Circuit;
4451 procedure Analyze_Slice (N : Node_Id) is
4452 P : constant Node_Id := Prefix (N);
4453 D : constant Node_Id := Discrete_Range (N);
4454 Array_Type : Entity_Id;
4456 procedure Analyze_Overloaded_Slice;
4457 -- If the prefix is overloaded, select those interpretations that
4458 -- yield a one-dimensional array type.
4460 ------------------------------
4461 -- Analyze_Overloaded_Slice --
4462 ------------------------------
4464 procedure Analyze_Overloaded_Slice is
4470 Set_Etype (N, Any_Type);
4472 Get_First_Interp (P, I, It);
4473 while Present (It.Nam) loop
4476 if Is_Access_Type (Typ) then
4477 Typ := Designated_Type (Typ);
4478 Error_Msg_NW (Warn_On_Dereference, "?implicit dereference", N);
4481 if Is_Array_Type (Typ)
4482 and then Number_Dimensions (Typ) = 1
4483 and then Has_Compatible_Type (D, Etype (First_Index (Typ)))
4485 Add_One_Interp (N, Typ, Typ);
4488 Get_Next_Interp (I, It);
4491 if Etype (N) = Any_Type then
4492 Error_Msg_N ("expect array type in prefix of slice", N);
4494 end Analyze_Overloaded_Slice;
4496 -- Start of processing for Analyze_Slice
4499 if Comes_From_Source (N) then
4500 Check_SPARK_Restriction ("slice is not allowed", N);
4506 if Is_Overloaded (P) then
4507 Analyze_Overloaded_Slice;
4510 Array_Type := Etype (P);
4511 Set_Etype (N, Any_Type);
4513 if Is_Access_Type (Array_Type) then
4514 Array_Type := Designated_Type (Array_Type);
4515 Error_Msg_NW (Warn_On_Dereference, "?implicit dereference", N);
4518 if not Is_Array_Type (Array_Type) then
4519 Wrong_Type (P, Any_Array);
4521 elsif Number_Dimensions (Array_Type) > 1 then
4523 ("type is not one-dimensional array in slice prefix", N);
4526 Has_Compatible_Type (D, Etype (First_Index (Array_Type)))
4528 Wrong_Type (D, Etype (First_Index (Array_Type)));
4531 Set_Etype (N, Array_Type);
4536 -----------------------------
4537 -- Analyze_Type_Conversion --
4538 -----------------------------
4540 procedure Analyze_Type_Conversion (N : Node_Id) is
4541 Expr : constant Node_Id := Expression (N);
4545 -- If Conversion_OK is set, then the Etype is already set, and the
4546 -- only processing required is to analyze the expression. This is
4547 -- used to construct certain "illegal" conversions which are not
4548 -- allowed by Ada semantics, but can be handled OK by Gigi, see
4549 -- Sinfo for further details.
4551 if Conversion_OK (N) then
4556 -- Otherwise full type analysis is required, as well as some semantic
4557 -- checks to make sure the argument of the conversion is appropriate.
4559 Find_Type (Subtype_Mark (N));
4560 T := Entity (Subtype_Mark (N));
4562 Check_Fully_Declared (T, N);
4563 Analyze_Expression (Expr);
4564 Validate_Remote_Type_Type_Conversion (N);
4566 -- Only remaining step is validity checks on the argument. These
4567 -- are skipped if the conversion does not come from the source.
4569 if not Comes_From_Source (N) then
4572 -- If there was an error in a generic unit, no need to replicate the
4573 -- error message. Conversely, constant-folding in the generic may
4574 -- transform the argument of a conversion into a string literal, which
4575 -- is legal. Therefore the following tests are not performed in an
4578 elsif In_Instance then
4581 elsif Nkind (Expr) = N_Null then
4582 Error_Msg_N ("argument of conversion cannot be null", N);
4583 Error_Msg_N ("\use qualified expression instead", N);
4584 Set_Etype (N, Any_Type);
4586 elsif Nkind (Expr) = N_Aggregate then
4587 Error_Msg_N ("argument of conversion cannot be aggregate", N);
4588 Error_Msg_N ("\use qualified expression instead", N);
4590 elsif Nkind (Expr) = N_Allocator then
4591 Error_Msg_N ("argument of conversion cannot be an allocator", N);
4592 Error_Msg_N ("\use qualified expression instead", N);
4594 elsif Nkind (Expr) = N_String_Literal then
4595 Error_Msg_N ("argument of conversion cannot be string literal", N);
4596 Error_Msg_N ("\use qualified expression instead", N);
4598 elsif Nkind (Expr) = N_Character_Literal then
4599 if Ada_Version = Ada_83 then
4602 Error_Msg_N ("argument of conversion cannot be character literal",
4604 Error_Msg_N ("\use qualified expression instead", N);
4607 elsif Nkind (Expr) = N_Attribute_Reference
4609 (Attribute_Name (Expr) = Name_Access or else
4610 Attribute_Name (Expr) = Name_Unchecked_Access or else
4611 Attribute_Name (Expr) = Name_Unrestricted_Access)
4613 Error_Msg_N ("argument of conversion cannot be access", N);
4614 Error_Msg_N ("\use qualified expression instead", N);
4616 end Analyze_Type_Conversion;
4618 ----------------------
4619 -- Analyze_Unary_Op --
4620 ----------------------
4622 procedure Analyze_Unary_Op (N : Node_Id) is
4623 R : constant Node_Id := Right_Opnd (N);
4624 Op_Id : Entity_Id := Entity (N);
4627 Set_Etype (N, Any_Type);
4628 Candidate_Type := Empty;
4630 Analyze_Expression (R);
4632 if Present (Op_Id) then
4633 if Ekind (Op_Id) = E_Operator then
4634 Find_Unary_Types (R, Op_Id, N);
4636 Add_One_Interp (N, Op_Id, Etype (Op_Id));
4640 Op_Id := Get_Name_Entity_Id (Chars (N));
4641 while Present (Op_Id) loop
4642 if Ekind (Op_Id) = E_Operator then
4643 if No (Next_Entity (First_Entity (Op_Id))) then
4644 Find_Unary_Types (R, Op_Id, N);
4647 elsif Is_Overloadable (Op_Id) then
4648 Analyze_User_Defined_Unary_Op (N, Op_Id);
4651 Op_Id := Homonym (Op_Id);
4656 end Analyze_Unary_Op;
4658 ----------------------------------
4659 -- Analyze_Unchecked_Expression --
4660 ----------------------------------
4662 procedure Analyze_Unchecked_Expression (N : Node_Id) is
4664 Analyze (Expression (N), Suppress => All_Checks);
4665 Set_Etype (N, Etype (Expression (N)));
4666 Save_Interps (Expression (N), N);
4667 end Analyze_Unchecked_Expression;
4669 ---------------------------------------
4670 -- Analyze_Unchecked_Type_Conversion --
4671 ---------------------------------------
4673 procedure Analyze_Unchecked_Type_Conversion (N : Node_Id) is
4675 Find_Type (Subtype_Mark (N));
4676 Analyze_Expression (Expression (N));
4677 Set_Etype (N, Entity (Subtype_Mark (N)));
4678 end Analyze_Unchecked_Type_Conversion;
4680 ------------------------------------
4681 -- Analyze_User_Defined_Binary_Op --
4682 ------------------------------------
4684 procedure Analyze_User_Defined_Binary_Op
4689 -- Only do analysis if the operator Comes_From_Source, since otherwise
4690 -- the operator was generated by the expander, and all such operators
4691 -- always refer to the operators in package Standard.
4693 if Comes_From_Source (N) then
4695 F1 : constant Entity_Id := First_Formal (Op_Id);
4696 F2 : constant Entity_Id := Next_Formal (F1);
4699 -- Verify that Op_Id is a visible binary function. Note that since
4700 -- we know Op_Id is overloaded, potentially use visible means use
4701 -- visible for sure (RM 9.4(11)).
4703 if Ekind (Op_Id) = E_Function
4704 and then Present (F2)
4705 and then (Is_Immediately_Visible (Op_Id)
4706 or else Is_Potentially_Use_Visible (Op_Id))
4707 and then Has_Compatible_Type (Left_Opnd (N), Etype (F1))
4708 and then Has_Compatible_Type (Right_Opnd (N), Etype (F2))
4710 Add_One_Interp (N, Op_Id, Etype (Op_Id));
4712 -- If the left operand is overloaded, indicate that the
4713 -- current type is a viable candidate. This is redundant
4714 -- in most cases, but for equality and comparison operators
4715 -- where the context does not impose a type on the operands,
4716 -- setting the proper type is necessary to avoid subsequent
4717 -- ambiguities during resolution, when both user-defined and
4718 -- predefined operators may be candidates.
4720 if Is_Overloaded (Left_Opnd (N)) then
4721 Set_Etype (Left_Opnd (N), Etype (F1));
4724 if Debug_Flag_E then
4725 Write_Str ("user defined operator ");
4726 Write_Name (Chars (Op_Id));
4727 Write_Str (" on node ");
4728 Write_Int (Int (N));
4734 end Analyze_User_Defined_Binary_Op;
4736 -----------------------------------
4737 -- Analyze_User_Defined_Unary_Op --
4738 -----------------------------------
4740 procedure Analyze_User_Defined_Unary_Op
4745 -- Only do analysis if the operator Comes_From_Source, since otherwise
4746 -- the operator was generated by the expander, and all such operators
4747 -- always refer to the operators in package Standard.
4749 if Comes_From_Source (N) then
4751 F : constant Entity_Id := First_Formal (Op_Id);
4754 -- Verify that Op_Id is a visible unary function. Note that since
4755 -- we know Op_Id is overloaded, potentially use visible means use
4756 -- visible for sure (RM 9.4(11)).
4758 if Ekind (Op_Id) = E_Function
4759 and then No (Next_Formal (F))
4760 and then (Is_Immediately_Visible (Op_Id)
4761 or else Is_Potentially_Use_Visible (Op_Id))
4762 and then Has_Compatible_Type (Right_Opnd (N), Etype (F))
4764 Add_One_Interp (N, Op_Id, Etype (Op_Id));
4768 end Analyze_User_Defined_Unary_Op;
4770 ---------------------------
4771 -- Check_Arithmetic_Pair --
4772 ---------------------------
4774 procedure Check_Arithmetic_Pair
4775 (T1, T2 : Entity_Id;
4779 Op_Name : constant Name_Id := Chars (Op_Id);
4781 function Has_Fixed_Op (Typ : Entity_Id; Op : Entity_Id) return Boolean;
4782 -- Check whether the fixed-point type Typ has a user-defined operator
4783 -- (multiplication or division) that should hide the corresponding
4784 -- predefined operator. Used to implement Ada 2005 AI-264, to make
4785 -- such operators more visible and therefore useful.
4787 -- If the name of the operation is an expanded name with prefix
4788 -- Standard, the predefined universal fixed operator is available,
4789 -- as specified by AI-420 (RM 4.5.5 (19.1/2)).
4791 function Specific_Type (T1, T2 : Entity_Id) return Entity_Id;
4792 -- Get specific type (i.e. non-universal type if there is one)
4798 function Has_Fixed_Op (Typ : Entity_Id; Op : Entity_Id) return Boolean is
4799 Bas : constant Entity_Id := Base_Type (Typ);
4805 -- If the universal_fixed operation is given explicitly the rule
4806 -- concerning primitive operations of the type do not apply.
4808 if Nkind (N) = N_Function_Call
4809 and then Nkind (Name (N)) = N_Expanded_Name
4810 and then Entity (Prefix (Name (N))) = Standard_Standard
4815 -- The operation is treated as primitive if it is declared in the
4816 -- same scope as the type, and therefore on the same entity chain.
4818 Ent := Next_Entity (Typ);
4819 while Present (Ent) loop
4820 if Chars (Ent) = Chars (Op) then
4821 F1 := First_Formal (Ent);
4822 F2 := Next_Formal (F1);
4824 -- The operation counts as primitive if either operand or
4825 -- result are of the given base type, and both operands are
4826 -- fixed point types.
4828 if (Base_Type (Etype (F1)) = Bas
4829 and then Is_Fixed_Point_Type (Etype (F2)))
4832 (Base_Type (Etype (F2)) = Bas
4833 and then Is_Fixed_Point_Type (Etype (F1)))
4836 (Base_Type (Etype (Ent)) = Bas
4837 and then Is_Fixed_Point_Type (Etype (F1))
4838 and then Is_Fixed_Point_Type (Etype (F2)))
4854 function Specific_Type (T1, T2 : Entity_Id) return Entity_Id is
4856 if T1 = Universal_Integer or else T1 = Universal_Real then
4857 return Base_Type (T2);
4859 return Base_Type (T1);
4863 -- Start of processing for Check_Arithmetic_Pair
4866 if Op_Name = Name_Op_Add or else Op_Name = Name_Op_Subtract then
4868 if Is_Numeric_Type (T1)
4869 and then Is_Numeric_Type (T2)
4870 and then (Covers (T1 => T1, T2 => T2)
4872 Covers (T1 => T2, T2 => T1))
4874 Add_One_Interp (N, Op_Id, Specific_Type (T1, T2));
4877 elsif Op_Name = Name_Op_Multiply or else Op_Name = Name_Op_Divide then
4879 if Is_Fixed_Point_Type (T1)
4880 and then (Is_Fixed_Point_Type (T2)
4881 or else T2 = Universal_Real)
4883 -- If Treat_Fixed_As_Integer is set then the Etype is already set
4884 -- and no further processing is required (this is the case of an
4885 -- operator constructed by Exp_Fixd for a fixed point operation)
4886 -- Otherwise add one interpretation with universal fixed result
4887 -- If the operator is given in functional notation, it comes
4888 -- from source and Fixed_As_Integer cannot apply.
4890 if (Nkind (N) not in N_Op
4891 or else not Treat_Fixed_As_Integer (N))
4893 (not Has_Fixed_Op (T1, Op_Id)
4894 or else Nkind (Parent (N)) = N_Type_Conversion)
4896 Add_One_Interp (N, Op_Id, Universal_Fixed);
4899 elsif Is_Fixed_Point_Type (T2)
4900 and then (Nkind (N) not in N_Op
4901 or else not Treat_Fixed_As_Integer (N))
4902 and then T1 = Universal_Real
4904 (not Has_Fixed_Op (T1, Op_Id)
4905 or else Nkind (Parent (N)) = N_Type_Conversion)
4907 Add_One_Interp (N, Op_Id, Universal_Fixed);
4909 elsif Is_Numeric_Type (T1)
4910 and then Is_Numeric_Type (T2)
4911 and then (Covers (T1 => T1, T2 => T2)
4913 Covers (T1 => T2, T2 => T1))
4915 Add_One_Interp (N, Op_Id, Specific_Type (T1, T2));
4917 elsif Is_Fixed_Point_Type (T1)
4918 and then (Base_Type (T2) = Base_Type (Standard_Integer)
4919 or else T2 = Universal_Integer)
4921 Add_One_Interp (N, Op_Id, T1);
4923 elsif T2 = Universal_Real
4924 and then Base_Type (T1) = Base_Type (Standard_Integer)
4925 and then Op_Name = Name_Op_Multiply
4927 Add_One_Interp (N, Op_Id, Any_Fixed);
4929 elsif T1 = Universal_Real
4930 and then Base_Type (T2) = Base_Type (Standard_Integer)
4932 Add_One_Interp (N, Op_Id, Any_Fixed);
4934 elsif Is_Fixed_Point_Type (T2)
4935 and then (Base_Type (T1) = Base_Type (Standard_Integer)
4936 or else T1 = Universal_Integer)
4937 and then Op_Name = Name_Op_Multiply
4939 Add_One_Interp (N, Op_Id, T2);
4941 elsif T1 = Universal_Real and then T2 = Universal_Integer then
4942 Add_One_Interp (N, Op_Id, T1);
4944 elsif T2 = Universal_Real
4945 and then T1 = Universal_Integer
4946 and then Op_Name = Name_Op_Multiply
4948 Add_One_Interp (N, Op_Id, T2);
4951 elsif Op_Name = Name_Op_Mod or else Op_Name = Name_Op_Rem then
4953 -- Note: The fixed-point operands case with Treat_Fixed_As_Integer
4954 -- set does not require any special processing, since the Etype is
4955 -- already set (case of operation constructed by Exp_Fixed).
4957 if Is_Integer_Type (T1)
4958 and then (Covers (T1 => T1, T2 => T2)
4960 Covers (T1 => T2, T2 => T1))
4962 Add_One_Interp (N, Op_Id, Specific_Type (T1, T2));
4965 elsif Op_Name = Name_Op_Expon then
4966 if Is_Numeric_Type (T1)
4967 and then not Is_Fixed_Point_Type (T1)
4968 and then (Base_Type (T2) = Base_Type (Standard_Integer)
4969 or else T2 = Universal_Integer)
4971 Add_One_Interp (N, Op_Id, Base_Type (T1));
4974 else pragma Assert (Nkind (N) in N_Op_Shift);
4976 -- If not one of the predefined operators, the node may be one
4977 -- of the intrinsic functions. Its kind is always specific, and
4978 -- we can use it directly, rather than the name of the operation.
4980 if Is_Integer_Type (T1)
4981 and then (Base_Type (T2) = Base_Type (Standard_Integer)
4982 or else T2 = Universal_Integer)
4984 Add_One_Interp (N, Op_Id, Base_Type (T1));
4987 end Check_Arithmetic_Pair;
4989 -------------------------------
4990 -- Check_Misspelled_Selector --
4991 -------------------------------
4993 procedure Check_Misspelled_Selector
4994 (Prefix : Entity_Id;
4997 Max_Suggestions : constant := 2;
4998 Nr_Of_Suggestions : Natural := 0;
5000 Suggestion_1 : Entity_Id := Empty;
5001 Suggestion_2 : Entity_Id := Empty;
5006 -- All the components of the prefix of selector Sel are matched
5007 -- against Sel and a count is maintained of possible misspellings.
5008 -- When at the end of the analysis there are one or two (not more!)
5009 -- possible misspellings, these misspellings will be suggested as
5010 -- possible correction.
5012 if not (Is_Private_Type (Prefix) or else Is_Record_Type (Prefix)) then
5014 -- Concurrent types should be handled as well ???
5019 Comp := First_Entity (Prefix);
5020 while Nr_Of_Suggestions <= Max_Suggestions and then Present (Comp) loop
5021 if Is_Visible_Component (Comp) then
5022 if Is_Bad_Spelling_Of (Chars (Comp), Chars (Sel)) then
5023 Nr_Of_Suggestions := Nr_Of_Suggestions + 1;
5025 case Nr_Of_Suggestions is
5026 when 1 => Suggestion_1 := Comp;
5027 when 2 => Suggestion_2 := Comp;
5028 when others => exit;
5033 Comp := Next_Entity (Comp);
5036 -- Report at most two suggestions
5038 if Nr_Of_Suggestions = 1 then
5039 Error_Msg_NE -- CODEFIX
5040 ("\possible misspelling of&", Sel, Suggestion_1);
5042 elsif Nr_Of_Suggestions = 2 then
5043 Error_Msg_Node_2 := Suggestion_2;
5044 Error_Msg_NE -- CODEFIX
5045 ("\possible misspelling of& or&", Sel, Suggestion_1);
5047 end Check_Misspelled_Selector;
5049 ----------------------
5050 -- Defined_In_Scope --
5051 ----------------------
5053 function Defined_In_Scope (T : Entity_Id; S : Entity_Id) return Boolean
5055 S1 : constant Entity_Id := Scope (Base_Type (T));
5058 or else (S1 = System_Aux_Id and then S = Scope (S1));
5059 end Defined_In_Scope;
5065 procedure Diagnose_Call (N : Node_Id; Nam : Node_Id) is
5071 Void_Interp_Seen : Boolean := False;
5074 pragma Warnings (Off, Boolean);
5077 if Ada_Version >= Ada_2005 then
5078 Actual := First_Actual (N);
5079 while Present (Actual) loop
5081 -- Ada 2005 (AI-50217): Post an error in case of premature
5082 -- usage of an entity from the limited view.
5084 if not Analyzed (Etype (Actual))
5085 and then From_With_Type (Etype (Actual))
5087 Error_Msg_Qual_Level := 1;
5089 ("missing with_clause for scope of imported type&",
5090 Actual, Etype (Actual));
5091 Error_Msg_Qual_Level := 0;
5094 Next_Actual (Actual);
5098 -- Analyze each candidate call again, with full error reporting
5102 ("no candidate interpretations match the actuals:!", Nam);
5103 Err_Mode := All_Errors_Mode;
5104 All_Errors_Mode := True;
5106 -- If this is a call to an operation of a concurrent type,
5107 -- the failed interpretations have been removed from the
5108 -- name. Recover them to provide full diagnostics.
5110 if Nkind (Parent (Nam)) = N_Selected_Component then
5111 Set_Entity (Nam, Empty);
5112 New_Nam := New_Copy_Tree (Parent (Nam));
5113 Set_Is_Overloaded (New_Nam, False);
5114 Set_Is_Overloaded (Selector_Name (New_Nam), False);
5115 Set_Parent (New_Nam, Parent (Parent (Nam)));
5116 Analyze_Selected_Component (New_Nam);
5117 Get_First_Interp (Selector_Name (New_Nam), X, It);
5119 Get_First_Interp (Nam, X, It);
5122 while Present (It.Nam) loop
5123 if Etype (It.Nam) = Standard_Void_Type then
5124 Void_Interp_Seen := True;
5127 Analyze_One_Call (N, It.Nam, True, Success);
5128 Get_Next_Interp (X, It);
5131 if Nkind (N) = N_Function_Call then
5132 Get_First_Interp (Nam, X, It);
5133 while Present (It.Nam) loop
5134 if Ekind_In (It.Nam, E_Function, E_Operator) then
5137 Get_Next_Interp (X, It);
5141 -- If all interpretations are procedures, this deserves a
5142 -- more precise message. Ditto if this appears as the prefix
5143 -- of a selected component, which may be a lexical error.
5146 ("\context requires function call, found procedure name", Nam);
5148 if Nkind (Parent (N)) = N_Selected_Component
5149 and then N = Prefix (Parent (N))
5151 Error_Msg_N -- CODEFIX
5152 ("\period should probably be semicolon", Parent (N));
5155 elsif Nkind (N) = N_Procedure_Call_Statement
5156 and then not Void_Interp_Seen
5159 "\function name found in procedure call", Nam);
5162 All_Errors_Mode := Err_Mode;
5165 ---------------------------
5166 -- Find_Arithmetic_Types --
5167 ---------------------------
5169 procedure Find_Arithmetic_Types
5174 Index1 : Interp_Index;
5175 Index2 : Interp_Index;
5179 procedure Check_Right_Argument (T : Entity_Id);
5180 -- Check right operand of operator
5182 --------------------------
5183 -- Check_Right_Argument --
5184 --------------------------
5186 procedure Check_Right_Argument (T : Entity_Id) is
5188 if not Is_Overloaded (R) then
5189 Check_Arithmetic_Pair (T, Etype (R), Op_Id, N);
5191 Get_First_Interp (R, Index2, It2);
5192 while Present (It2.Typ) loop
5193 Check_Arithmetic_Pair (T, It2.Typ, Op_Id, N);
5194 Get_Next_Interp (Index2, It2);
5197 end Check_Right_Argument;
5199 -- Start of processing for Find_Arithmetic_Types
5202 if not Is_Overloaded (L) then
5203 Check_Right_Argument (Etype (L));
5206 Get_First_Interp (L, Index1, It1);
5207 while Present (It1.Typ) loop
5208 Check_Right_Argument (It1.Typ);
5209 Get_Next_Interp (Index1, It1);
5213 end Find_Arithmetic_Types;
5215 ------------------------
5216 -- Find_Boolean_Types --
5217 ------------------------
5219 procedure Find_Boolean_Types
5224 Index : Interp_Index;
5227 procedure Check_Numeric_Argument (T : Entity_Id);
5228 -- Special case for logical operations one of whose operands is an
5229 -- integer literal. If both are literal the result is any modular type.
5231 ----------------------------
5232 -- Check_Numeric_Argument --
5233 ----------------------------
5235 procedure Check_Numeric_Argument (T : Entity_Id) is
5237 if T = Universal_Integer then
5238 Add_One_Interp (N, Op_Id, Any_Modular);
5240 elsif Is_Modular_Integer_Type (T) then
5241 Add_One_Interp (N, Op_Id, T);
5243 end Check_Numeric_Argument;
5245 -- Start of processing for Find_Boolean_Types
5248 if not Is_Overloaded (L) then
5249 if Etype (L) = Universal_Integer
5250 or else Etype (L) = Any_Modular
5252 if not Is_Overloaded (R) then
5253 Check_Numeric_Argument (Etype (R));
5256 Get_First_Interp (R, Index, It);
5257 while Present (It.Typ) loop
5258 Check_Numeric_Argument (It.Typ);
5259 Get_Next_Interp (Index, It);
5263 -- If operands are aggregates, we must assume that they may be
5264 -- boolean arrays, and leave disambiguation for the second pass.
5265 -- If only one is an aggregate, verify that the other one has an
5266 -- interpretation as a boolean array
5268 elsif Nkind (L) = N_Aggregate then
5269 if Nkind (R) = N_Aggregate then
5270 Add_One_Interp (N, Op_Id, Etype (L));
5272 elsif not Is_Overloaded (R) then
5273 if Valid_Boolean_Arg (Etype (R)) then
5274 Add_One_Interp (N, Op_Id, Etype (R));
5278 Get_First_Interp (R, Index, It);
5279 while Present (It.Typ) loop
5280 if Valid_Boolean_Arg (It.Typ) then
5281 Add_One_Interp (N, Op_Id, It.Typ);
5284 Get_Next_Interp (Index, It);
5288 elsif Valid_Boolean_Arg (Etype (L))
5289 and then Has_Compatible_Type (R, Etype (L))
5291 Add_One_Interp (N, Op_Id, Etype (L));
5295 Get_First_Interp (L, Index, It);
5296 while Present (It.Typ) loop
5297 if Valid_Boolean_Arg (It.Typ)
5298 and then Has_Compatible_Type (R, It.Typ)
5300 Add_One_Interp (N, Op_Id, It.Typ);
5303 Get_Next_Interp (Index, It);
5306 end Find_Boolean_Types;
5308 ---------------------------
5309 -- Find_Comparison_Types --
5310 ---------------------------
5312 procedure Find_Comparison_Types
5317 Index : Interp_Index;
5319 Found : Boolean := False;
5322 Scop : Entity_Id := Empty;
5324 procedure Try_One_Interp (T1 : Entity_Id);
5325 -- Routine to try one proposed interpretation. Note that the context
5326 -- of the operator plays no role in resolving the arguments, so that
5327 -- if there is more than one interpretation of the operands that is
5328 -- compatible with comparison, the operation is ambiguous.
5330 --------------------
5331 -- Try_One_Interp --
5332 --------------------
5334 procedure Try_One_Interp (T1 : Entity_Id) is
5337 -- If the operator is an expanded name, then the type of the operand
5338 -- must be defined in the corresponding scope. If the type is
5339 -- universal, the context will impose the correct type.
5342 and then not Defined_In_Scope (T1, Scop)
5343 and then T1 /= Universal_Integer
5344 and then T1 /= Universal_Real
5345 and then T1 /= Any_String
5346 and then T1 /= Any_Composite
5351 if Valid_Comparison_Arg (T1)
5352 and then Has_Compatible_Type (R, T1)
5355 and then Base_Type (T1) /= Base_Type (T_F)
5357 It := Disambiguate (L, I_F, Index, Any_Type);
5359 if It = No_Interp then
5360 Ambiguous_Operands (N);
5361 Set_Etype (L, Any_Type);
5375 Find_Non_Universal_Interpretations (N, R, Op_Id, T1);
5380 -- Start of processing for Find_Comparison_Types
5383 -- If left operand is aggregate, the right operand has to
5384 -- provide a usable type for it.
5386 if Nkind (L) = N_Aggregate
5387 and then Nkind (R) /= N_Aggregate
5389 Find_Comparison_Types (L => R, R => L, Op_Id => Op_Id, N => N);
5393 if Nkind (N) = N_Function_Call
5394 and then Nkind (Name (N)) = N_Expanded_Name
5396 Scop := Entity (Prefix (Name (N)));
5398 -- The prefix may be a package renaming, and the subsequent test
5399 -- requires the original package.
5401 if Ekind (Scop) = E_Package
5402 and then Present (Renamed_Entity (Scop))
5404 Scop := Renamed_Entity (Scop);
5405 Set_Entity (Prefix (Name (N)), Scop);
5409 if not Is_Overloaded (L) then
5410 Try_One_Interp (Etype (L));
5413 Get_First_Interp (L, Index, It);
5414 while Present (It.Typ) loop
5415 Try_One_Interp (It.Typ);
5416 Get_Next_Interp (Index, It);
5419 end Find_Comparison_Types;
5421 ----------------------------------------
5422 -- Find_Non_Universal_Interpretations --
5423 ----------------------------------------
5425 procedure Find_Non_Universal_Interpretations
5431 Index : Interp_Index;
5435 if T1 = Universal_Integer
5436 or else T1 = Universal_Real
5438 if not Is_Overloaded (R) then
5440 (N, Op_Id, Standard_Boolean, Base_Type (Etype (R)));
5442 Get_First_Interp (R, Index, It);
5443 while Present (It.Typ) loop
5444 if Covers (It.Typ, T1) then
5446 (N, Op_Id, Standard_Boolean, Base_Type (It.Typ));
5449 Get_Next_Interp (Index, It);
5453 Add_One_Interp (N, Op_Id, Standard_Boolean, Base_Type (T1));
5455 end Find_Non_Universal_Interpretations;
5457 ------------------------------
5458 -- Find_Concatenation_Types --
5459 ------------------------------
5461 procedure Find_Concatenation_Types
5466 Op_Type : constant Entity_Id := Etype (Op_Id);
5469 if Is_Array_Type (Op_Type)
5470 and then not Is_Limited_Type (Op_Type)
5472 and then (Has_Compatible_Type (L, Op_Type)
5474 Has_Compatible_Type (L, Component_Type (Op_Type)))
5476 and then (Has_Compatible_Type (R, Op_Type)
5478 Has_Compatible_Type (R, Component_Type (Op_Type)))
5480 Add_One_Interp (N, Op_Id, Op_Type);
5482 end Find_Concatenation_Types;
5484 -------------------------
5485 -- Find_Equality_Types --
5486 -------------------------
5488 procedure Find_Equality_Types
5493 Index : Interp_Index;
5495 Found : Boolean := False;
5498 Scop : Entity_Id := Empty;
5500 procedure Try_One_Interp (T1 : Entity_Id);
5501 -- The context of the equality operator plays no role in resolving the
5502 -- arguments, so that if there is more than one interpretation of the
5503 -- operands that is compatible with equality, the construct is ambiguous
5504 -- and an error can be emitted now, after trying to disambiguate, i.e.
5505 -- applying preference rules.
5507 --------------------
5508 -- Try_One_Interp --
5509 --------------------
5511 procedure Try_One_Interp (T1 : Entity_Id) is
5512 Bas : constant Entity_Id := Base_Type (T1);
5515 -- If the operator is an expanded name, then the type of the operand
5516 -- must be defined in the corresponding scope. If the type is
5517 -- universal, the context will impose the correct type. An anonymous
5518 -- type for a 'Access reference is also universal in this sense, as
5519 -- the actual type is obtained from context.
5520 -- In Ada 2005, the equality operator for anonymous access types
5521 -- is declared in Standard, and preference rules apply to it.
5523 if Present (Scop) then
5524 if Defined_In_Scope (T1, Scop)
5525 or else T1 = Universal_Integer
5526 or else T1 = Universal_Real
5527 or else T1 = Any_Access
5528 or else T1 = Any_String
5529 or else T1 = Any_Composite
5530 or else (Ekind (T1) = E_Access_Subprogram_Type
5531 and then not Comes_From_Source (T1))
5535 elsif Ekind (T1) = E_Anonymous_Access_Type
5536 and then Scop = Standard_Standard
5541 -- The scope does not contain an operator for the type
5546 -- If we have infix notation, the operator must be usable.
5547 -- Within an instance, if the type is already established we
5548 -- know it is correct. If an operand is universal it is compatible
5549 -- with any numeric type.
5551 -- In Ada 2005, the equality on anonymous access types is declared
5552 -- in Standard, and is always visible.
5554 elsif In_Open_Scopes (Scope (Bas))
5555 or else Is_Potentially_Use_Visible (Bas)
5556 or else In_Use (Bas)
5557 or else (In_Use (Scope (Bas))
5558 and then not Is_Hidden (Bas))
5560 or else (In_Instance
5562 (First_Subtype (T1) = First_Subtype (Etype (R))
5563 or else (Is_Numeric_Type (T1)
5564 and then Is_Universal_Numeric_Type (Etype (R)))))
5566 or else Ekind (T1) = E_Anonymous_Access_Type
5571 -- Save candidate type for subsequent error message, if any
5573 if not Is_Limited_Type (T1) then
5574 Candidate_Type := T1;
5580 -- Ada 2005 (AI-230): Keep restriction imposed by Ada 83 and 95:
5581 -- Do not allow anonymous access types in equality operators.
5583 if Ada_Version < Ada_2005
5584 and then Ekind (T1) = E_Anonymous_Access_Type
5589 if T1 /= Standard_Void_Type
5590 and then Has_Compatible_Type (R, T1)
5592 ((not Is_Limited_Type (T1)
5593 and then not Is_Limited_Composite (T1))
5597 and then not Is_Limited_Type (Component_Type (T1))
5598 and then Available_Full_View_Of_Component (T1)))
5601 and then Base_Type (T1) /= Base_Type (T_F)
5603 It := Disambiguate (L, I_F, Index, Any_Type);
5605 if It = No_Interp then
5606 Ambiguous_Operands (N);
5607 Set_Etype (L, Any_Type);
5620 if not Analyzed (L) then
5624 Find_Non_Universal_Interpretations (N, R, Op_Id, T1);
5626 -- Case of operator was not visible, Etype still set to Any_Type
5628 if Etype (N) = Any_Type then
5632 elsif Scop = Standard_Standard
5633 and then Ekind (T1) = E_Anonymous_Access_Type
5639 -- Start of processing for Find_Equality_Types
5642 -- If left operand is aggregate, the right operand has to
5643 -- provide a usable type for it.
5645 if Nkind (L) = N_Aggregate
5646 and then Nkind (R) /= N_Aggregate
5648 Find_Equality_Types (L => R, R => L, Op_Id => Op_Id, N => N);
5652 if Nkind (N) = N_Function_Call
5653 and then Nkind (Name (N)) = N_Expanded_Name
5655 Scop := Entity (Prefix (Name (N)));
5657 -- The prefix may be a package renaming, and the subsequent test
5658 -- requires the original package.
5660 if Ekind (Scop) = E_Package
5661 and then Present (Renamed_Entity (Scop))
5663 Scop := Renamed_Entity (Scop);
5664 Set_Entity (Prefix (Name (N)), Scop);
5668 if not Is_Overloaded (L) then
5669 Try_One_Interp (Etype (L));
5672 Get_First_Interp (L, Index, It);
5673 while Present (It.Typ) loop
5674 Try_One_Interp (It.Typ);
5675 Get_Next_Interp (Index, It);
5678 end Find_Equality_Types;
5680 -------------------------
5681 -- Find_Negation_Types --
5682 -------------------------
5684 procedure Find_Negation_Types
5689 Index : Interp_Index;
5693 if not Is_Overloaded (R) then
5694 if Etype (R) = Universal_Integer then
5695 Add_One_Interp (N, Op_Id, Any_Modular);
5696 elsif Valid_Boolean_Arg (Etype (R)) then
5697 Add_One_Interp (N, Op_Id, Etype (R));
5701 Get_First_Interp (R, Index, It);
5702 while Present (It.Typ) loop
5703 if Valid_Boolean_Arg (It.Typ) then
5704 Add_One_Interp (N, Op_Id, It.Typ);
5707 Get_Next_Interp (Index, It);
5710 end Find_Negation_Types;
5712 ------------------------------
5713 -- Find_Primitive_Operation --
5714 ------------------------------
5716 function Find_Primitive_Operation (N : Node_Id) return Boolean is
5717 Obj : constant Node_Id := Prefix (N);
5718 Op : constant Node_Id := Selector_Name (N);
5725 Set_Etype (Op, Any_Type);
5727 if Is_Access_Type (Etype (Obj)) then
5728 Typ := Designated_Type (Etype (Obj));
5733 if Is_Class_Wide_Type (Typ) then
5734 Typ := Root_Type (Typ);
5737 Prims := Primitive_Operations (Typ);
5739 Prim := First_Elmt (Prims);
5740 while Present (Prim) loop
5741 if Chars (Node (Prim)) = Chars (Op) then
5742 Add_One_Interp (Op, Node (Prim), Etype (Node (Prim)));
5743 Set_Etype (N, Etype (Node (Prim)));
5749 -- Now look for class-wide operations of the type or any of its
5750 -- ancestors by iterating over the homonyms of the selector.
5753 Cls_Type : constant Entity_Id := Class_Wide_Type (Typ);
5757 Hom := Current_Entity (Op);
5758 while Present (Hom) loop
5759 if (Ekind (Hom) = E_Procedure
5761 Ekind (Hom) = E_Function)
5762 and then Scope (Hom) = Scope (Typ)
5763 and then Present (First_Formal (Hom))
5765 (Base_Type (Etype (First_Formal (Hom))) = Cls_Type
5767 (Is_Access_Type (Etype (First_Formal (Hom)))
5769 Ekind (Etype (First_Formal (Hom))) =
5770 E_Anonymous_Access_Type
5773 (Designated_Type (Etype (First_Formal (Hom)))) =
5776 Add_One_Interp (Op, Hom, Etype (Hom));
5777 Set_Etype (N, Etype (Hom));
5780 Hom := Homonym (Hom);
5784 return Etype (Op) /= Any_Type;
5785 end Find_Primitive_Operation;
5787 ----------------------
5788 -- Find_Unary_Types --
5789 ----------------------
5791 procedure Find_Unary_Types
5796 Index : Interp_Index;
5800 if not Is_Overloaded (R) then
5801 if Is_Numeric_Type (Etype (R)) then
5802 Add_One_Interp (N, Op_Id, Base_Type (Etype (R)));
5806 Get_First_Interp (R, Index, It);
5807 while Present (It.Typ) loop
5808 if Is_Numeric_Type (It.Typ) then
5809 Add_One_Interp (N, Op_Id, Base_Type (It.Typ));
5812 Get_Next_Interp (Index, It);
5815 end Find_Unary_Types;
5821 function Junk_Operand (N : Node_Id) return Boolean is
5825 if Error_Posted (N) then
5829 -- Get entity to be tested
5831 if Is_Entity_Name (N)
5832 and then Present (Entity (N))
5836 -- An odd case, a procedure name gets converted to a very peculiar
5837 -- function call, and here is where we detect this happening.
5839 elsif Nkind (N) = N_Function_Call
5840 and then Is_Entity_Name (Name (N))
5841 and then Present (Entity (Name (N)))
5845 -- Another odd case, there are at least some cases of selected
5846 -- components where the selected component is not marked as having
5847 -- an entity, even though the selector does have an entity
5849 elsif Nkind (N) = N_Selected_Component
5850 and then Present (Entity (Selector_Name (N)))
5852 Enode := Selector_Name (N);
5858 -- Now test the entity we got to see if it is a bad case
5860 case Ekind (Entity (Enode)) is
5864 ("package name cannot be used as operand", Enode);
5866 when Generic_Unit_Kind =>
5868 ("generic unit name cannot be used as operand", Enode);
5872 ("subtype name cannot be used as operand", Enode);
5876 ("entry name cannot be used as operand", Enode);
5880 ("procedure name cannot be used as operand", Enode);
5884 ("exception name cannot be used as operand", Enode);
5886 when E_Block | E_Label | E_Loop =>
5888 ("label name cannot be used as operand", Enode);
5898 --------------------
5899 -- Operator_Check --
5900 --------------------
5902 procedure Operator_Check (N : Node_Id) is
5904 Remove_Abstract_Operations (N);
5906 -- Test for case of no interpretation found for operator
5908 if Etype (N) = Any_Type then
5912 Op_Id : Entity_Id := Empty;
5915 R := Right_Opnd (N);
5917 if Nkind (N) in N_Binary_Op then
5923 -- If either operand has no type, then don't complain further,
5924 -- since this simply means that we have a propagated error.
5927 or else Etype (R) = Any_Type
5928 or else (Nkind (N) in N_Binary_Op and then Etype (L) = Any_Type)
5932 -- We explicitly check for the case of concatenation of component
5933 -- with component to avoid reporting spurious matching array types
5934 -- that might happen to be lurking in distant packages (such as
5935 -- run-time packages). This also prevents inconsistencies in the
5936 -- messages for certain ACVC B tests, which can vary depending on
5937 -- types declared in run-time interfaces. Another improvement when
5938 -- aggregates are present is to look for a well-typed operand.
5940 elsif Present (Candidate_Type)
5941 and then (Nkind (N) /= N_Op_Concat
5942 or else Is_Array_Type (Etype (L))
5943 or else Is_Array_Type (Etype (R)))
5945 if Nkind (N) = N_Op_Concat then
5946 if Etype (L) /= Any_Composite
5947 and then Is_Array_Type (Etype (L))
5949 Candidate_Type := Etype (L);
5951 elsif Etype (R) /= Any_Composite
5952 and then Is_Array_Type (Etype (R))
5954 Candidate_Type := Etype (R);
5958 Error_Msg_NE -- CODEFIX
5959 ("operator for} is not directly visible!",
5960 N, First_Subtype (Candidate_Type));
5963 U : constant Node_Id :=
5964 Cunit (Get_Source_Unit (Candidate_Type));
5966 if Unit_Is_Visible (U) then
5967 Error_Msg_N -- CODEFIX
5968 ("use clause would make operation legal!", N);
5970 Error_Msg_NE -- CODEFIX
5971 ("add with_clause and use_clause for&!",
5972 N, Defining_Entity (Unit (U)));
5977 -- If either operand is a junk operand (e.g. package name), then
5978 -- post appropriate error messages, but do not complain further.
5980 -- Note that the use of OR in this test instead of OR ELSE is
5981 -- quite deliberate, we may as well check both operands in the
5982 -- binary operator case.
5984 elsif Junk_Operand (R)
5985 or (Nkind (N) in N_Binary_Op and then Junk_Operand (L))
5989 -- If we have a logical operator, one of whose operands is
5990 -- Boolean, then we know that the other operand cannot resolve to
5991 -- Boolean (since we got no interpretations), but in that case we
5992 -- pretty much know that the other operand should be Boolean, so
5993 -- resolve it that way (generating an error)
5995 elsif Nkind_In (N, N_Op_And, N_Op_Or, N_Op_Xor) then
5996 if Etype (L) = Standard_Boolean then
5997 Resolve (R, Standard_Boolean);
5999 elsif Etype (R) = Standard_Boolean then
6000 Resolve (L, Standard_Boolean);
6004 -- For an arithmetic operator or comparison operator, if one
6005 -- of the operands is numeric, then we know the other operand
6006 -- is not the same numeric type. If it is a non-numeric type,
6007 -- then probably it is intended to match the other operand.
6009 elsif Nkind_In (N, N_Op_Add,
6015 Nkind_In (N, N_Op_Lt,
6021 if Is_Numeric_Type (Etype (L))
6022 and then not Is_Numeric_Type (Etype (R))
6024 Resolve (R, Etype (L));
6027 elsif Is_Numeric_Type (Etype (R))
6028 and then not Is_Numeric_Type (Etype (L))
6030 Resolve (L, Etype (R));
6034 -- Comparisons on A'Access are common enough to deserve a
6037 elsif Nkind_In (N, N_Op_Eq, N_Op_Ne)
6038 and then Ekind (Etype (L)) = E_Access_Attribute_Type
6039 and then Ekind (Etype (R)) = E_Access_Attribute_Type
6042 ("two access attributes cannot be compared directly", N);
6044 ("\use qualified expression for one of the operands",
6048 -- Another one for C programmers
6050 elsif Nkind (N) = N_Op_Concat
6051 and then Valid_Boolean_Arg (Etype (L))
6052 and then Valid_Boolean_Arg (Etype (R))
6054 Error_Msg_N ("invalid operands for concatenation", N);
6055 Error_Msg_N -- CODEFIX
6056 ("\maybe AND was meant", N);
6059 -- A special case for comparison of access parameter with null
6061 elsif Nkind (N) = N_Op_Eq
6062 and then Is_Entity_Name (L)
6063 and then Nkind (Parent (Entity (L))) = N_Parameter_Specification
6064 and then Nkind (Parameter_Type (Parent (Entity (L)))) =
6066 and then Nkind (R) = N_Null
6068 Error_Msg_N ("access parameter is not allowed to be null", L);
6069 Error_Msg_N ("\(call would raise Constraint_Error)", L);
6072 -- Another special case for exponentiation, where the right
6073 -- operand must be Natural, independently of the base.
6075 elsif Nkind (N) = N_Op_Expon
6076 and then Is_Numeric_Type (Etype (L))
6077 and then not Is_Overloaded (R)
6079 First_Subtype (Base_Type (Etype (R))) /= Standard_Integer
6080 and then Base_Type (Etype (R)) /= Universal_Integer
6082 if Ada_Version >= Ada_2012
6083 and then Has_Dimension_System (Etype (L))
6086 ("exponent for dimensioned type must be a rational" &
6087 ", found}", R, Etype (R));
6090 ("exponent must be of type Natural, found}", R, Etype (R));
6096 -- If we fall through then just give general message. Note that in
6097 -- the following messages, if the operand is overloaded we choose
6098 -- an arbitrary type to complain about, but that is probably more
6099 -- useful than not giving a type at all.
6101 if Nkind (N) in N_Unary_Op then
6102 Error_Msg_Node_2 := Etype (R);
6103 Error_Msg_N ("operator& not defined for}", N);
6107 if Nkind (N) in N_Binary_Op then
6108 if not Is_Overloaded (L)
6109 and then not Is_Overloaded (R)
6110 and then Base_Type (Etype (L)) = Base_Type (Etype (R))
6112 Error_Msg_Node_2 := First_Subtype (Etype (R));
6113 Error_Msg_N ("there is no applicable operator& for}", N);
6116 -- Another attempt to find a fix: one of the candidate
6117 -- interpretations may not be use-visible. This has
6118 -- already been checked for predefined operators, so
6119 -- we examine only user-defined functions.
6121 Op_Id := Get_Name_Entity_Id (Chars (N));
6123 while Present (Op_Id) loop
6124 if Ekind (Op_Id) /= E_Operator
6125 and then Is_Overloadable (Op_Id)
6127 if not Is_Immediately_Visible (Op_Id)
6128 and then not In_Use (Scope (Op_Id))
6129 and then not Is_Abstract_Subprogram (Op_Id)
6130 and then not Is_Hidden (Op_Id)
6131 and then Ekind (Scope (Op_Id)) = E_Package
6134 (L, Etype (First_Formal (Op_Id)))
6136 (Next_Formal (First_Formal (Op_Id)))
6140 Etype (Next_Formal (First_Formal (Op_Id))))
6143 ("No legal interpretation for operator&", N);
6145 ("\use clause on& would make operation legal",
6151 Op_Id := Homonym (Op_Id);
6155 Error_Msg_N ("invalid operand types for operator&", N);
6157 if Nkind (N) /= N_Op_Concat then
6158 Error_Msg_NE ("\left operand has}!", N, Etype (L));
6159 Error_Msg_NE ("\right operand has}!", N, Etype (R));
6169 -----------------------------------------
6170 -- Process_Implicit_Dereference_Prefix --
6171 -----------------------------------------
6173 function Process_Implicit_Dereference_Prefix
6175 P : Entity_Id) return Entity_Id
6178 Typ : constant Entity_Id := Designated_Type (Etype (P));
6182 and then (Operating_Mode = Check_Semantics or else not Expander_Active)
6184 -- We create a dummy reference to E to ensure that the reference
6185 -- is not considered as part of an assignment (an implicit
6186 -- dereference can never assign to its prefix). The Comes_From_Source
6187 -- attribute needs to be propagated for accurate warnings.
6189 Ref := New_Reference_To (E, Sloc (P));
6190 Set_Comes_From_Source (Ref, Comes_From_Source (P));
6191 Generate_Reference (E, Ref);
6194 -- An implicit dereference is a legal occurrence of an
6195 -- incomplete type imported through a limited_with clause,
6196 -- if the full view is visible.
6198 if From_With_Type (Typ)
6199 and then not From_With_Type (Scope (Typ))
6201 (Is_Immediately_Visible (Scope (Typ))
6203 (Is_Child_Unit (Scope (Typ))
6204 and then Is_Visible_Child_Unit (Scope (Typ))))
6206 return Available_View (Typ);
6211 end Process_Implicit_Dereference_Prefix;
6213 --------------------------------
6214 -- Remove_Abstract_Operations --
6215 --------------------------------
6217 procedure Remove_Abstract_Operations (N : Node_Id) is
6218 Abstract_Op : Entity_Id := Empty;
6219 Address_Kludge : Boolean := False;
6223 -- AI-310: If overloaded, remove abstract non-dispatching operations. We
6224 -- activate this if either extensions are enabled, or if the abstract
6225 -- operation in question comes from a predefined file. This latter test
6226 -- allows us to use abstract to make operations invisible to users. In
6227 -- particular, if type Address is non-private and abstract subprograms
6228 -- are used to hide its operators, they will be truly hidden.
6230 type Operand_Position is (First_Op, Second_Op);
6231 Univ_Type : constant Entity_Id := Universal_Interpretation (N);
6233 procedure Remove_Address_Interpretations (Op : Operand_Position);
6234 -- Ambiguities may arise when the operands are literal and the address
6235 -- operations in s-auxdec are visible. In that case, remove the
6236 -- interpretation of a literal as Address, to retain the semantics of
6237 -- Address as a private type.
6239 ------------------------------------
6240 -- Remove_Address_Interpretations --
6241 ------------------------------------
6243 procedure Remove_Address_Interpretations (Op : Operand_Position) is
6247 if Is_Overloaded (N) then
6248 Get_First_Interp (N, I, It);
6249 while Present (It.Nam) loop
6250 Formal := First_Entity (It.Nam);
6252 if Op = Second_Op then
6253 Formal := Next_Entity (Formal);
6256 if Is_Descendent_Of_Address (Etype (Formal)) then
6257 Address_Kludge := True;
6261 Get_Next_Interp (I, It);
6264 end Remove_Address_Interpretations;
6266 -- Start of processing for Remove_Abstract_Operations
6269 if Is_Overloaded (N) then
6270 if Debug_Flag_V then
6271 Write_Str ("Remove_Abstract_Operations: ");
6272 Write_Overloads (N);
6275 Get_First_Interp (N, I, It);
6277 while Present (It.Nam) loop
6278 if Is_Overloadable (It.Nam)
6279 and then Is_Abstract_Subprogram (It.Nam)
6280 and then not Is_Dispatching_Operation (It.Nam)
6282 Abstract_Op := It.Nam;
6284 if Is_Descendent_Of_Address (It.Typ) then
6285 Address_Kludge := True;
6289 -- In Ada 2005, this operation does not participate in overload
6290 -- resolution. If the operation is defined in a predefined
6291 -- unit, it is one of the operations declared abstract in some
6292 -- variants of System, and it must be removed as well.
6294 elsif Ada_Version >= Ada_2005
6295 or else Is_Predefined_File_Name
6296 (Unit_File_Name (Get_Source_Unit (It.Nam)))
6303 Get_Next_Interp (I, It);
6306 if No (Abstract_Op) then
6308 -- If some interpretation yields an integer type, it is still
6309 -- possible that there are address interpretations. Remove them
6310 -- if one operand is a literal, to avoid spurious ambiguities
6311 -- on systems where Address is a visible integer type.
6313 if Is_Overloaded (N)
6314 and then Nkind (N) in N_Op
6315 and then Is_Integer_Type (Etype (N))
6317 if Nkind (N) in N_Binary_Op then
6318 if Nkind (Right_Opnd (N)) = N_Integer_Literal then
6319 Remove_Address_Interpretations (Second_Op);
6321 elsif Nkind (Right_Opnd (N)) = N_Integer_Literal then
6322 Remove_Address_Interpretations (First_Op);
6327 elsif Nkind (N) in N_Op then
6329 -- Remove interpretations that treat literals as addresses. This
6330 -- is never appropriate, even when Address is defined as a visible
6331 -- Integer type. The reason is that we would really prefer Address
6332 -- to behave as a private type, even in this case, which is there
6333 -- only to accommodate oddities of VMS address sizes. If Address
6334 -- is a visible integer type, we get lots of overload ambiguities.
6336 if Nkind (N) in N_Binary_Op then
6338 U1 : constant Boolean :=
6339 Present (Universal_Interpretation (Right_Opnd (N)));
6340 U2 : constant Boolean :=
6341 Present (Universal_Interpretation (Left_Opnd (N)));
6345 Remove_Address_Interpretations (Second_Op);
6349 Remove_Address_Interpretations (First_Op);
6352 if not (U1 and U2) then
6354 -- Remove corresponding predefined operator, which is
6355 -- always added to the overload set.
6357 Get_First_Interp (N, I, It);
6358 while Present (It.Nam) loop
6359 if Scope (It.Nam) = Standard_Standard
6360 and then Base_Type (It.Typ) =
6361 Base_Type (Etype (Abstract_Op))
6366 Get_Next_Interp (I, It);
6369 elsif Is_Overloaded (N)
6370 and then Present (Univ_Type)
6372 -- If both operands have a universal interpretation,
6373 -- it is still necessary to remove interpretations that
6374 -- yield Address. Any remaining ambiguities will be
6375 -- removed in Disambiguate.
6377 Get_First_Interp (N, I, It);
6378 while Present (It.Nam) loop
6379 if Is_Descendent_Of_Address (It.Typ) then
6382 elsif not Is_Type (It.Nam) then
6383 Set_Entity (N, It.Nam);
6386 Get_Next_Interp (I, It);
6392 elsif Nkind (N) = N_Function_Call
6394 (Nkind (Name (N)) = N_Operator_Symbol
6396 (Nkind (Name (N)) = N_Expanded_Name
6398 Nkind (Selector_Name (Name (N))) = N_Operator_Symbol))
6402 Arg1 : constant Node_Id := First (Parameter_Associations (N));
6403 U1 : constant Boolean :=
6404 Present (Universal_Interpretation (Arg1));
6405 U2 : constant Boolean :=
6406 Present (Next (Arg1)) and then
6407 Present (Universal_Interpretation (Next (Arg1)));
6411 Remove_Address_Interpretations (First_Op);
6415 Remove_Address_Interpretations (Second_Op);
6418 if not (U1 and U2) then
6419 Get_First_Interp (N, I, It);
6420 while Present (It.Nam) loop
6421 if Scope (It.Nam) = Standard_Standard
6422 and then It.Typ = Base_Type (Etype (Abstract_Op))
6427 Get_Next_Interp (I, It);
6433 -- If the removal has left no valid interpretations, emit an error
6434 -- message now and label node as illegal.
6436 if Present (Abstract_Op) then
6437 Get_First_Interp (N, I, It);
6441 -- Removal of abstract operation left no viable candidate
6443 Set_Etype (N, Any_Type);
6444 Error_Msg_Sloc := Sloc (Abstract_Op);
6446 ("cannot call abstract operation& declared#", N, Abstract_Op);
6448 -- In Ada 2005, an abstract operation may disable predefined
6449 -- operators. Since the context is not yet known, we mark the
6450 -- predefined operators as potentially hidden. Do not include
6451 -- predefined operators when addresses are involved since this
6452 -- case is handled separately.
6454 elsif Ada_Version >= Ada_2005
6455 and then not Address_Kludge
6457 while Present (It.Nam) loop
6458 if Is_Numeric_Type (It.Typ)
6459 and then Scope (It.Typ) = Standard_Standard
6461 Set_Abstract_Op (I, Abstract_Op);
6464 Get_Next_Interp (I, It);
6469 if Debug_Flag_V then
6470 Write_Str ("Remove_Abstract_Operations done: ");
6471 Write_Overloads (N);
6474 end Remove_Abstract_Operations;
6476 ----------------------------
6477 -- Try_Container_Indexing --
6478 ----------------------------
6480 function Try_Container_Indexing
6483 Expr : Node_Id) return Boolean
6485 Loc : constant Source_Ptr := Sloc (N);
6488 Func_Name : Node_Id;
6493 -- Check whether type has a specified indexing aspect
6497 if Is_Variable (Prefix) then
6498 Func_Name := Find_Aspect (Etype (Prefix), Aspect_Variable_Indexing);
6501 if No (Func_Name) then
6502 Func_Name := Find_Aspect (Etype (Prefix), Aspect_Constant_Indexing);
6505 -- If aspect does not exist the expression is illegal. Error is
6506 -- diagnosed in caller.
6508 if No (Func_Name) then
6510 -- The prefix itself may be an indexing of a container
6511 -- rewrite as such and re-analyze.
6513 if Has_Implicit_Dereference (Etype (Prefix)) then
6514 Build_Explicit_Dereference
6515 (Prefix, First_Discriminant (Etype (Prefix)));
6516 return Try_Container_Indexing (N, Prefix, Expr);
6523 if not Is_Overloaded (Func_Name) then
6524 Func := Entity (Func_Name);
6525 Indexing := Make_Function_Call (Loc,
6526 Name => New_Occurrence_Of (Func, Loc),
6527 Parameter_Associations =>
6528 New_List (Relocate_Node (Prefix), Relocate_Node (Expr)));
6529 Rewrite (N, Indexing);
6532 -- If the return type of the indexing function is a reference type,
6533 -- add the dereference as a possible interpretation. Note that the
6534 -- indexing aspect may be a function that returns the element type
6535 -- with no intervening implicit dereference.
6537 if Has_Discriminants (Etype (Func)) then
6538 Disc := First_Discriminant (Etype (Func));
6539 while Present (Disc) loop
6540 if Has_Implicit_Dereference (Disc) then
6541 Add_One_Interp (N, Disc, Designated_Type (Etype (Disc)));
6545 Next_Discriminant (Disc);
6550 Indexing := Make_Function_Call (Loc,
6551 Name => Make_Identifier (Loc, Chars (Func_Name)),
6552 Parameter_Associations =>
6553 New_List (Relocate_Node (Prefix), Relocate_Node (Expr)));
6555 Rewrite (N, Indexing);
6563 Get_First_Interp (Func_Name, I, It);
6564 Set_Etype (N, Any_Type);
6565 while Present (It.Nam) loop
6566 Analyze_One_Call (N, It.Nam, False, Success);
6568 Set_Etype (Name (N), It.Typ);
6569 Set_Entity (Name (N), It.Nam);
6571 -- Add implicit dereference interpretation
6573 if Has_Discriminants (Etype (It.Nam)) then
6574 Disc := First_Discriminant (Etype (It.Nam));
6575 while Present (Disc) loop
6576 if Has_Implicit_Dereference (Disc) then
6578 (N, Disc, Designated_Type (Etype (Disc)));
6582 Next_Discriminant (Disc);
6588 Get_Next_Interp (I, It);
6593 if Etype (N) = Any_Type then
6594 Error_Msg_NE ("container cannot be indexed with&", N, Etype (Expr));
6595 Rewrite (N, New_Occurrence_Of (Any_Id, Loc));
6601 end Try_Container_Indexing;
6603 -----------------------
6604 -- Try_Indirect_Call --
6605 -----------------------
6607 function Try_Indirect_Call
6610 Typ : Entity_Id) return Boolean
6616 pragma Warnings (Off, Call_OK);
6619 Normalize_Actuals (N, Designated_Type (Typ), False, Call_OK);
6621 Actual := First_Actual (N);
6622 Formal := First_Formal (Designated_Type (Typ));
6623 while Present (Actual) and then Present (Formal) loop
6624 if not Has_Compatible_Type (Actual, Etype (Formal)) then
6629 Next_Formal (Formal);
6632 if No (Actual) and then No (Formal) then
6633 Add_One_Interp (N, Nam, Etype (Designated_Type (Typ)));
6635 -- Nam is a candidate interpretation for the name in the call,
6636 -- if it is not an indirect call.
6638 if not Is_Type (Nam)
6639 and then Is_Entity_Name (Name (N))
6641 Set_Entity (Name (N), Nam);
6648 end Try_Indirect_Call;
6650 ----------------------
6651 -- Try_Indexed_Call --
6652 ----------------------
6654 function Try_Indexed_Call
6658 Skip_First : Boolean) return Boolean
6660 Loc : constant Source_Ptr := Sloc (N);
6661 Actuals : constant List_Id := Parameter_Associations (N);
6666 Actual := First (Actuals);
6668 -- If the call was originally written in prefix form, skip the first
6669 -- actual, which is obviously not defaulted.
6675 Index := First_Index (Typ);
6676 while Present (Actual) and then Present (Index) loop
6678 -- If the parameter list has a named association, the expression
6679 -- is definitely a call and not an indexed component.
6681 if Nkind (Actual) = N_Parameter_Association then
6685 if Is_Entity_Name (Actual)
6686 and then Is_Type (Entity (Actual))
6687 and then No (Next (Actual))
6689 -- A single actual that is a type name indicates a slice if the
6690 -- type is discrete, and an error otherwise.
6692 if Is_Discrete_Type (Entity (Actual)) then
6696 Make_Function_Call (Loc,
6697 Name => Relocate_Node (Name (N))),
6699 New_Occurrence_Of (Entity (Actual), Sloc (Actual))));
6704 Error_Msg_N ("invalid use of type in expression", Actual);
6705 Set_Etype (N, Any_Type);
6710 elsif not Has_Compatible_Type (Actual, Etype (Index)) then
6718 if No (Actual) and then No (Index) then
6719 Add_One_Interp (N, Nam, Component_Type (Typ));
6721 -- Nam is a candidate interpretation for the name in the call,
6722 -- if it is not an indirect call.
6724 if not Is_Type (Nam)
6725 and then Is_Entity_Name (Name (N))
6727 Set_Entity (Name (N), Nam);
6734 end Try_Indexed_Call;
6736 --------------------------
6737 -- Try_Object_Operation --
6738 --------------------------
6740 function Try_Object_Operation
6741 (N : Node_Id; CW_Test_Only : Boolean := False) return Boolean
6743 K : constant Node_Kind := Nkind (Parent (N));
6744 Is_Subprg_Call : constant Boolean := Nkind_In
6745 (K, N_Procedure_Call_Statement,
6747 Loc : constant Source_Ptr := Sloc (N);
6748 Obj : constant Node_Id := Prefix (N);
6750 Subprog : constant Node_Id :=
6751 Make_Identifier (Sloc (Selector_Name (N)),
6752 Chars => Chars (Selector_Name (N)));
6753 -- Identifier on which possible interpretations will be collected
6755 Report_Error : Boolean := False;
6756 -- If no candidate interpretation matches the context, redo the
6757 -- analysis with error enabled to provide additional information.
6760 Candidate : Entity_Id := Empty;
6761 New_Call_Node : Node_Id := Empty;
6762 Node_To_Replace : Node_Id;
6763 Obj_Type : Entity_Id := Etype (Obj);
6764 Success : Boolean := False;
6766 function Valid_Candidate
6769 Subp : Entity_Id) return Entity_Id;
6770 -- If the subprogram is a valid interpretation, record it, and add
6771 -- to the list of interpretations of Subprog. Otherwise return Empty.
6773 procedure Complete_Object_Operation
6774 (Call_Node : Node_Id;
6775 Node_To_Replace : Node_Id);
6776 -- Make Subprog the name of Call_Node, replace Node_To_Replace with
6777 -- Call_Node, insert the object (or its dereference) as the first actual
6778 -- in the call, and complete the analysis of the call.
6780 procedure Report_Ambiguity (Op : Entity_Id);
6781 -- If a prefixed procedure call is ambiguous, indicate whether the
6782 -- call includes an implicit dereference or an implicit 'Access.
6784 procedure Transform_Object_Operation
6785 (Call_Node : out Node_Id;
6786 Node_To_Replace : out Node_Id);
6787 -- Transform Obj.Operation (X, Y,,) into Operation (Obj, X, Y ..)
6788 -- Call_Node is the resulting subprogram call, Node_To_Replace is
6789 -- either N or the parent of N, and Subprog is a reference to the
6790 -- subprogram we are trying to match.
6792 function Try_Class_Wide_Operation
6793 (Call_Node : Node_Id;
6794 Node_To_Replace : Node_Id) return Boolean;
6795 -- Traverse all ancestor types looking for a class-wide subprogram
6796 -- for which the current operation is a valid non-dispatching call.
6798 procedure Try_One_Prefix_Interpretation (T : Entity_Id);
6799 -- If prefix is overloaded, its interpretation may include different
6800 -- tagged types, and we must examine the primitive operations and
6801 -- the class-wide operations of each in order to find candidate
6802 -- interpretations for the call as a whole.
6804 function Try_Primitive_Operation
6805 (Call_Node : Node_Id;
6806 Node_To_Replace : Node_Id) return Boolean;
6807 -- Traverse the list of primitive subprograms looking for a dispatching
6808 -- operation for which the current node is a valid call .
6810 ---------------------
6811 -- Valid_Candidate --
6812 ---------------------
6814 function Valid_Candidate
6817 Subp : Entity_Id) return Entity_Id
6819 Arr_Type : Entity_Id;
6820 Comp_Type : Entity_Id;
6823 -- If the subprogram is a valid interpretation, record it in global
6824 -- variable Subprog, to collect all possible overloadings.
6827 if Subp /= Entity (Subprog) then
6828 Add_One_Interp (Subprog, Subp, Etype (Subp));
6832 -- If the call may be an indexed call, retrieve component type of
6833 -- resulting expression, and add possible interpretation.
6838 if Nkind (Call) = N_Function_Call
6839 and then Nkind (Parent (N)) = N_Indexed_Component
6840 and then Needs_One_Actual (Subp)
6842 if Is_Array_Type (Etype (Subp)) then
6843 Arr_Type := Etype (Subp);
6845 elsif Is_Access_Type (Etype (Subp))
6846 and then Is_Array_Type (Designated_Type (Etype (Subp)))
6848 Arr_Type := Designated_Type (Etype (Subp));
6852 if Present (Arr_Type) then
6854 -- Verify that the actuals (excluding the object) match the types
6862 Actual := Next (First_Actual (Call));
6863 Index := First_Index (Arr_Type);
6864 while Present (Actual) and then Present (Index) loop
6865 if not Has_Compatible_Type (Actual, Etype (Index)) then
6870 Next_Actual (Actual);
6876 and then Present (Arr_Type)
6878 Comp_Type := Component_Type (Arr_Type);
6882 if Present (Comp_Type)
6883 and then Etype (Subprog) /= Comp_Type
6885 Add_One_Interp (Subprog, Subp, Comp_Type);
6889 if Etype (Call) /= Any_Type then
6894 end Valid_Candidate;
6896 -------------------------------
6897 -- Complete_Object_Operation --
6898 -------------------------------
6900 procedure Complete_Object_Operation
6901 (Call_Node : Node_Id;
6902 Node_To_Replace : Node_Id)
6904 Control : constant Entity_Id := First_Formal (Entity (Subprog));
6905 Formal_Type : constant Entity_Id := Etype (Control);
6906 First_Actual : Node_Id;
6909 -- Place the name of the operation, with its interpretations,
6910 -- on the rewritten call.
6912 Set_Name (Call_Node, Subprog);
6914 First_Actual := First (Parameter_Associations (Call_Node));
6916 -- For cross-reference purposes, treat the new node as being in
6917 -- the source if the original one is. Set entity and type, even
6918 -- though they may be overwritten during resolution if overloaded.
6920 Set_Comes_From_Source (Subprog, Comes_From_Source (N));
6921 Set_Comes_From_Source (Call_Node, Comes_From_Source (N));
6923 if Nkind (N) = N_Selected_Component
6924 and then not Inside_A_Generic
6926 Set_Entity (Selector_Name (N), Entity (Subprog));
6927 Set_Etype (Selector_Name (N), Etype (Entity (Subprog)));
6930 -- If need be, rewrite first actual as an explicit dereference
6931 -- If the call is overloaded, the rewriting can only be done
6932 -- once the primitive operation is identified.
6934 if Is_Overloaded (Subprog) then
6936 -- The prefix itself may be overloaded, and its interpretations
6937 -- must be propagated to the new actual in the call.
6939 if Is_Overloaded (Obj) then
6940 Save_Interps (Obj, First_Actual);
6943 Rewrite (First_Actual, Obj);
6945 elsif not Is_Access_Type (Formal_Type)
6946 and then Is_Access_Type (Etype (Obj))
6948 Rewrite (First_Actual,
6949 Make_Explicit_Dereference (Sloc (Obj), Obj));
6950 Analyze (First_Actual);
6952 -- If we need to introduce an explicit dereference, verify that
6953 -- the resulting actual is compatible with the mode of the formal.
6955 if Ekind (First_Formal (Entity (Subprog))) /= E_In_Parameter
6956 and then Is_Access_Constant (Etype (Obj))
6959 ("expect variable in call to&", Prefix (N), Entity (Subprog));
6962 -- Conversely, if the formal is an access parameter and the object
6963 -- is not, replace the actual with a 'Access reference. Its analysis
6964 -- will check that the object is aliased.
6966 elsif Is_Access_Type (Formal_Type)
6967 and then not Is_Access_Type (Etype (Obj))
6969 -- A special case: A.all'access is illegal if A is an access to a
6970 -- constant and the context requires an access to a variable.
6972 if not Is_Access_Constant (Formal_Type) then
6973 if (Nkind (Obj) = N_Explicit_Dereference
6974 and then Is_Access_Constant (Etype (Prefix (Obj))))
6975 or else not Is_Variable (Obj)
6978 ("actual for& must be a variable", Obj, Control);
6982 Rewrite (First_Actual,
6983 Make_Attribute_Reference (Loc,
6984 Attribute_Name => Name_Access,
6985 Prefix => Relocate_Node (Obj)));
6987 if not Is_Aliased_View (Obj) then
6989 ("object in prefixed call to& must be aliased"
6990 & " (RM-2005 4.3.1 (13))",
6991 Prefix (First_Actual), Subprog);
6994 Analyze (First_Actual);
6997 if Is_Overloaded (Obj) then
6998 Save_Interps (Obj, First_Actual);
7001 Rewrite (First_Actual, Obj);
7004 Rewrite (Node_To_Replace, Call_Node);
7006 -- Propagate the interpretations collected in subprog to the new
7007 -- function call node, to be resolved from context.
7009 if Is_Overloaded (Subprog) then
7010 Save_Interps (Subprog, Node_To_Replace);
7013 Analyze (Node_To_Replace);
7015 -- If the operation has been rewritten into a call, which may get
7016 -- subsequently an explicit dereference, preserve the type on the
7017 -- original node (selected component or indexed component) for
7018 -- subsequent legality tests, e.g. Is_Variable. which examines
7019 -- the original node.
7021 if Nkind (Node_To_Replace) = N_Function_Call then
7023 (Original_Node (Node_To_Replace), Etype (Node_To_Replace));
7026 end Complete_Object_Operation;
7028 ----------------------
7029 -- Report_Ambiguity --
7030 ----------------------
7032 procedure Report_Ambiguity (Op : Entity_Id) is
7033 Access_Actual : constant Boolean :=
7034 Is_Access_Type (Etype (Prefix (N)));
7035 Access_Formal : Boolean := False;
7038 Error_Msg_Sloc := Sloc (Op);
7040 if Present (First_Formal (Op)) then
7041 Access_Formal := Is_Access_Type (Etype (First_Formal (Op)));
7044 if Access_Formal and then not Access_Actual then
7045 if Nkind (Parent (Op)) = N_Full_Type_Declaration then
7047 ("\possible interpretation"
7048 & " (inherited, with implicit 'Access) #", N);
7051 ("\possible interpretation (with implicit 'Access) #", N);
7054 elsif not Access_Formal and then Access_Actual then
7055 if Nkind (Parent (Op)) = N_Full_Type_Declaration then
7057 ("\possible interpretation"
7058 & " ( inherited, with implicit dereference) #", N);
7061 ("\possible interpretation (with implicit dereference) #", N);
7065 if Nkind (Parent (Op)) = N_Full_Type_Declaration then
7066 Error_Msg_N ("\possible interpretation (inherited)#", N);
7068 Error_Msg_N -- CODEFIX
7069 ("\possible interpretation#", N);
7072 end Report_Ambiguity;
7074 --------------------------------
7075 -- Transform_Object_Operation --
7076 --------------------------------
7078 procedure Transform_Object_Operation
7079 (Call_Node : out Node_Id;
7080 Node_To_Replace : out Node_Id)
7082 Dummy : constant Node_Id := New_Copy (Obj);
7083 -- Placeholder used as a first parameter in the call, replaced
7084 -- eventually by the proper object.
7086 Parent_Node : constant Node_Id := Parent (N);
7092 -- Common case covering 1) Call to a procedure and 2) Call to a
7093 -- function that has some additional actuals.
7095 if Nkind_In (Parent_Node, N_Function_Call,
7096 N_Procedure_Call_Statement)
7098 -- N is a selected component node containing the name of the
7099 -- subprogram. If N is not the name of the parent node we must
7100 -- not replace the parent node by the new construct. This case
7101 -- occurs when N is a parameterless call to a subprogram that
7102 -- is an actual parameter of a call to another subprogram. For
7104 -- Some_Subprogram (..., Obj.Operation, ...)
7106 and then Name (Parent_Node) = N
7108 Node_To_Replace := Parent_Node;
7110 Actuals := Parameter_Associations (Parent_Node);
7112 if Present (Actuals) then
7113 Prepend (Dummy, Actuals);
7115 Actuals := New_List (Dummy);
7118 if Nkind (Parent_Node) = N_Procedure_Call_Statement then
7120 Make_Procedure_Call_Statement (Loc,
7121 Name => New_Copy (Subprog),
7122 Parameter_Associations => Actuals);
7126 Make_Function_Call (Loc,
7127 Name => New_Copy (Subprog),
7128 Parameter_Associations => Actuals);
7132 -- Before analysis, a function call appears as an indexed component
7133 -- if there are no named associations.
7135 elsif Nkind (Parent_Node) = N_Indexed_Component
7136 and then N = Prefix (Parent_Node)
7138 Node_To_Replace := Parent_Node;
7139 Actuals := Expressions (Parent_Node);
7141 Actual := First (Actuals);
7142 while Present (Actual) loop
7147 Prepend (Dummy, Actuals);
7150 Make_Function_Call (Loc,
7151 Name => New_Copy (Subprog),
7152 Parameter_Associations => Actuals);
7154 -- Parameterless call: Obj.F is rewritten as F (Obj)
7157 Node_To_Replace := N;
7160 Make_Function_Call (Loc,
7161 Name => New_Copy (Subprog),
7162 Parameter_Associations => New_List (Dummy));
7164 end Transform_Object_Operation;
7166 ------------------------------
7167 -- Try_Class_Wide_Operation --
7168 ------------------------------
7170 function Try_Class_Wide_Operation
7171 (Call_Node : Node_Id;
7172 Node_To_Replace : Node_Id) return Boolean
7174 Anc_Type : Entity_Id;
7175 Matching_Op : Entity_Id := Empty;
7178 procedure Traverse_Homonyms
7179 (Anc_Type : Entity_Id;
7180 Error : out Boolean);
7181 -- Traverse the homonym chain of the subprogram searching for those
7182 -- homonyms whose first formal has the Anc_Type's class-wide type,
7183 -- or an anonymous access type designating the class-wide type. If
7184 -- an ambiguity is detected, then Error is set to True.
7186 procedure Traverse_Interfaces
7187 (Anc_Type : Entity_Id;
7188 Error : out Boolean);
7189 -- Traverse the list of interfaces, if any, associated with Anc_Type
7190 -- and search for acceptable class-wide homonyms associated with each
7191 -- interface. If an ambiguity is detected, then Error is set to True.
7193 -----------------------
7194 -- Traverse_Homonyms --
7195 -----------------------
7197 procedure Traverse_Homonyms
7198 (Anc_Type : Entity_Id;
7199 Error : out Boolean)
7201 Cls_Type : Entity_Id;
7209 Cls_Type := Class_Wide_Type (Anc_Type);
7211 Hom := Current_Entity (Subprog);
7213 -- Find a non-hidden operation whose first parameter is of the
7214 -- class-wide type, a subtype thereof, or an anonymous access
7215 -- to same. If in an instance, the operation can be considered
7216 -- even if hidden (it may be hidden because the instantiation is
7217 -- expanded after the containing package has been analyzed).
7219 while Present (Hom) loop
7220 if Ekind_In (Hom, E_Procedure, E_Function)
7221 and then (not Is_Hidden (Hom) or else In_Instance)
7222 and then Scope (Hom) = Scope (Anc_Type)
7223 and then Present (First_Formal (Hom))
7225 (Base_Type (Etype (First_Formal (Hom))) = Cls_Type
7227 (Is_Access_Type (Etype (First_Formal (Hom)))
7229 Ekind (Etype (First_Formal (Hom))) =
7230 E_Anonymous_Access_Type
7233 (Designated_Type (Etype (First_Formal (Hom)))) =
7236 -- If the context is a procedure call, ignore functions
7237 -- in the name of the call.
7239 if Ekind (Hom) = E_Function
7240 and then Nkind (Parent (N)) = N_Procedure_Call_Statement
7241 and then N = Name (Parent (N))
7245 -- If the context is a function call, ignore procedures
7246 -- in the name of the call.
7248 elsif Ekind (Hom) = E_Procedure
7249 and then Nkind (Parent (N)) /= N_Procedure_Call_Statement
7254 Set_Etype (Call_Node, Any_Type);
7255 Set_Is_Overloaded (Call_Node, False);
7258 if No (Matching_Op) then
7259 Hom_Ref := New_Reference_To (Hom, Sloc (Subprog));
7260 Set_Etype (Call_Node, Any_Type);
7261 Set_Parent (Call_Node, Parent (Node_To_Replace));
7263 Set_Name (Call_Node, Hom_Ref);
7268 Report => Report_Error,
7270 Skip_First => True);
7273 Valid_Candidate (Success, Call_Node, Hom);
7279 Report => Report_Error,
7281 Skip_First => True);
7283 if Present (Valid_Candidate (Success, Call_Node, Hom))
7284 and then Nkind (Call_Node) /= N_Function_Call
7286 Error_Msg_NE ("ambiguous call to&", N, Hom);
7287 Report_Ambiguity (Matching_Op);
7288 Report_Ambiguity (Hom);
7296 Hom := Homonym (Hom);
7298 end Traverse_Homonyms;
7300 -------------------------
7301 -- Traverse_Interfaces --
7302 -------------------------
7304 procedure Traverse_Interfaces
7305 (Anc_Type : Entity_Id;
7306 Error : out Boolean)
7308 Intface_List : constant List_Id :=
7309 Abstract_Interface_List (Anc_Type);
7315 if Is_Non_Empty_List (Intface_List) then
7316 Intface := First (Intface_List);
7317 while Present (Intface) loop
7319 -- Look for acceptable class-wide homonyms associated with
7322 Traverse_Homonyms (Etype (Intface), Error);
7328 -- Continue the search by looking at each of the interface's
7329 -- associated interface ancestors.
7331 Traverse_Interfaces (Etype (Intface), Error);
7340 end Traverse_Interfaces;
7342 -- Start of processing for Try_Class_Wide_Operation
7345 -- If we are searching only for conflicting class-wide subprograms
7346 -- then initialize directly Matching_Op with the target entity.
7348 if CW_Test_Only then
7349 Matching_Op := Entity (Selector_Name (N));
7352 -- Loop through ancestor types (including interfaces), traversing
7353 -- the homonym chain of the subprogram, trying out those homonyms
7354 -- whose first formal has the class-wide type of the ancestor, or
7355 -- an anonymous access type designating the class-wide type.
7357 Anc_Type := Obj_Type;
7359 -- Look for a match among homonyms associated with the ancestor
7361 Traverse_Homonyms (Anc_Type, Error);
7367 -- Continue the search for matches among homonyms associated with
7368 -- any interfaces implemented by the ancestor.
7370 Traverse_Interfaces (Anc_Type, Error);
7376 exit when Etype (Anc_Type) = Anc_Type;
7377 Anc_Type := Etype (Anc_Type);
7380 if Present (Matching_Op) then
7381 Set_Etype (Call_Node, Etype (Matching_Op));
7384 return Present (Matching_Op);
7385 end Try_Class_Wide_Operation;
7387 -----------------------------------
7388 -- Try_One_Prefix_Interpretation --
7389 -----------------------------------
7391 procedure Try_One_Prefix_Interpretation (T : Entity_Id) is
7395 if Is_Access_Type (Obj_Type) then
7396 Obj_Type := Designated_Type (Obj_Type);
7399 if Ekind (Obj_Type) = E_Private_Subtype then
7400 Obj_Type := Base_Type (Obj_Type);
7403 if Is_Class_Wide_Type (Obj_Type) then
7404 Obj_Type := Etype (Class_Wide_Type (Obj_Type));
7407 -- The type may have be obtained through a limited_with clause,
7408 -- in which case the primitive operations are available on its
7409 -- non-limited view. If still incomplete, retrieve full view.
7411 if Ekind (Obj_Type) = E_Incomplete_Type
7412 and then From_With_Type (Obj_Type)
7414 Obj_Type := Get_Full_View (Non_Limited_View (Obj_Type));
7417 -- If the object is not tagged, or the type is still an incomplete
7418 -- type, this is not a prefixed call.
7420 if not Is_Tagged_Type (Obj_Type)
7421 or else Is_Incomplete_Type (Obj_Type)
7427 Dup_Call_Node : constant Node_Id := New_Copy (New_Call_Node);
7428 CW_Result : Boolean;
7429 Prim_Result : Boolean;
7430 pragma Unreferenced (CW_Result);
7433 if not CW_Test_Only then
7435 Try_Primitive_Operation
7436 (Call_Node => New_Call_Node,
7437 Node_To_Replace => Node_To_Replace);
7440 -- Check if there is a class-wide subprogram covering the
7441 -- primitive. This check must be done even if a candidate
7442 -- was found in order to report ambiguous calls.
7444 if not (Prim_Result) then
7446 Try_Class_Wide_Operation
7447 (Call_Node => New_Call_Node,
7448 Node_To_Replace => Node_To_Replace);
7450 -- If we found a primitive we search for class-wide subprograms
7451 -- using a duplicate of the call node (done to avoid missing its
7452 -- decoration if there is no ambiguity).
7456 Try_Class_Wide_Operation
7457 (Call_Node => Dup_Call_Node,
7458 Node_To_Replace => Node_To_Replace);
7461 end Try_One_Prefix_Interpretation;
7463 -----------------------------
7464 -- Try_Primitive_Operation --
7465 -----------------------------
7467 function Try_Primitive_Operation
7468 (Call_Node : Node_Id;
7469 Node_To_Replace : Node_Id) return Boolean
7472 Prim_Op : Entity_Id;
7473 Matching_Op : Entity_Id := Empty;
7474 Prim_Op_Ref : Node_Id := Empty;
7476 Corr_Type : Entity_Id := Empty;
7477 -- If the prefix is a synchronized type, the controlling type of
7478 -- the primitive operation is the corresponding record type, else
7479 -- this is the object type itself.
7481 Success : Boolean := False;
7483 function Collect_Generic_Type_Ops (T : Entity_Id) return Elist_Id;
7484 -- For tagged types the candidate interpretations are found in
7485 -- the list of primitive operations of the type and its ancestors.
7486 -- For formal tagged types we have to find the operations declared
7487 -- in the same scope as the type (including in the generic formal
7488 -- part) because the type itself carries no primitive operations,
7489 -- except for formal derived types that inherit the operations of
7490 -- the parent and progenitors.
7491 -- If the context is a generic subprogram body, the generic formals
7492 -- are visible by name, but are not in the entity list of the
7493 -- subprogram because that list starts with the subprogram formals.
7494 -- We retrieve the candidate operations from the generic declaration.
7496 function Is_Private_Overriding (Op : Entity_Id) return Boolean;
7497 -- An operation that overrides an inherited operation in the private
7498 -- part of its package may be hidden, but if the inherited operation
7499 -- is visible a direct call to it will dispatch to the private one,
7500 -- which is therefore a valid candidate.
7502 function Valid_First_Argument_Of (Op : Entity_Id) return Boolean;
7503 -- Verify that the prefix, dereferenced if need be, is a valid
7504 -- controlling argument in a call to Op. The remaining actuals
7505 -- are checked in the subsequent call to Analyze_One_Call.
7507 ------------------------------
7508 -- Collect_Generic_Type_Ops --
7509 ------------------------------
7511 function Collect_Generic_Type_Ops (T : Entity_Id) return Elist_Id is
7512 Bas : constant Entity_Id := Base_Type (T);
7513 Candidates : constant Elist_Id := New_Elmt_List;
7517 procedure Check_Candidate;
7518 -- The operation is a candidate if its first parameter is a
7519 -- controlling operand of the desired type.
7521 -----------------------
7522 -- Check_Candidate; --
7523 -----------------------
7525 procedure Check_Candidate is
7527 Formal := First_Formal (Subp);
7530 and then Is_Controlling_Formal (Formal)
7532 (Base_Type (Etype (Formal)) = Bas
7534 (Is_Access_Type (Etype (Formal))
7535 and then Designated_Type (Etype (Formal)) = Bas))
7537 Append_Elmt (Subp, Candidates);
7539 end Check_Candidate;
7541 -- Start of processing for Collect_Generic_Type_Ops
7544 if Is_Derived_Type (T) then
7545 return Primitive_Operations (T);
7547 elsif Ekind_In (Scope (T), E_Procedure, E_Function) then
7549 -- Scan the list of generic formals to find subprograms
7550 -- that may have a first controlling formal of the type.
7552 if Nkind (Unit_Declaration_Node (Scope (T)))
7553 = N_Generic_Subprogram_Declaration
7560 First (Generic_Formal_Declarations
7561 (Unit_Declaration_Node (Scope (T))));
7562 while Present (Decl) loop
7563 if Nkind (Decl) in N_Formal_Subprogram_Declaration then
7564 Subp := Defining_Entity (Decl);
7575 -- Scan the list of entities declared in the same scope as
7576 -- the type. In general this will be an open scope, given that
7577 -- the call we are analyzing can only appear within a generic
7578 -- declaration or body (either the one that declares T, or a
7581 -- For a subtype representing a generic actual type, go to the
7584 if Is_Generic_Actual_Type (T) then
7585 Subp := First_Entity (Scope (Base_Type (T)));
7587 Subp := First_Entity (Scope (T));
7590 while Present (Subp) loop
7591 if Is_Overloadable (Subp) then
7600 end Collect_Generic_Type_Ops;
7602 ---------------------------
7603 -- Is_Private_Overriding --
7604 ---------------------------
7606 function Is_Private_Overriding (Op : Entity_Id) return Boolean is
7607 Visible_Op : constant Entity_Id := Homonym (Op);
7610 return Present (Visible_Op)
7611 and then Scope (Op) = Scope (Visible_Op)
7612 and then not Comes_From_Source (Visible_Op)
7613 and then Alias (Visible_Op) = Op
7614 and then not Is_Hidden (Visible_Op);
7615 end Is_Private_Overriding;
7617 -----------------------------
7618 -- Valid_First_Argument_Of --
7619 -----------------------------
7621 function Valid_First_Argument_Of (Op : Entity_Id) return Boolean is
7622 Typ : Entity_Id := Etype (First_Formal (Op));
7625 if Is_Concurrent_Type (Typ)
7626 and then Present (Corresponding_Record_Type (Typ))
7628 Typ := Corresponding_Record_Type (Typ);
7631 -- Simple case. Object may be a subtype of the tagged type or
7632 -- may be the corresponding record of a synchronized type.
7634 return Obj_Type = Typ
7635 or else Base_Type (Obj_Type) = Typ
7636 or else Corr_Type = Typ
7638 -- Prefix can be dereferenced
7641 (Is_Access_Type (Corr_Type)
7642 and then Designated_Type (Corr_Type) = Typ)
7644 -- Formal is an access parameter, for which the object
7645 -- can provide an access.
7648 (Ekind (Typ) = E_Anonymous_Access_Type
7650 Base_Type (Designated_Type (Typ)) = Base_Type (Corr_Type));
7651 end Valid_First_Argument_Of;
7653 -- Start of processing for Try_Primitive_Operation
7656 -- Look for subprograms in the list of primitive operations. The name
7657 -- must be identical, and the kind of call indicates the expected
7658 -- kind of operation (function or procedure). If the type is a
7659 -- (tagged) synchronized type, the primitive ops are attached to the
7660 -- corresponding record (base) type.
7662 if Is_Concurrent_Type (Obj_Type) then
7663 if Present (Corresponding_Record_Type (Obj_Type)) then
7664 Corr_Type := Base_Type (Corresponding_Record_Type (Obj_Type));
7665 Elmt := First_Elmt (Primitive_Operations (Corr_Type));
7667 Corr_Type := Obj_Type;
7668 Elmt := First_Elmt (Collect_Generic_Type_Ops (Obj_Type));
7671 elsif not Is_Generic_Type (Obj_Type) then
7672 Corr_Type := Obj_Type;
7673 Elmt := First_Elmt (Primitive_Operations (Obj_Type));
7676 Corr_Type := Obj_Type;
7677 Elmt := First_Elmt (Collect_Generic_Type_Ops (Obj_Type));
7680 while Present (Elmt) loop
7681 Prim_Op := Node (Elmt);
7683 if Chars (Prim_Op) = Chars (Subprog)
7684 and then Present (First_Formal (Prim_Op))
7685 and then Valid_First_Argument_Of (Prim_Op)
7687 (Nkind (Call_Node) = N_Function_Call)
7688 = (Ekind (Prim_Op) = E_Function)
7690 -- Ada 2005 (AI-251): If this primitive operation corresponds
7691 -- with an immediate ancestor interface there is no need to add
7692 -- it to the list of interpretations; the corresponding aliased
7693 -- primitive is also in this list of primitive operations and
7694 -- will be used instead.
7696 if (Present (Interface_Alias (Prim_Op))
7697 and then Is_Ancestor (Find_Dispatching_Type
7698 (Alias (Prim_Op)), Corr_Type))
7700 -- Do not consider hidden primitives unless the type is in an
7701 -- open scope or we are within an instance, where visibility
7702 -- is known to be correct, or else if this is an overriding
7703 -- operation in the private part for an inherited operation.
7705 or else (Is_Hidden (Prim_Op)
7706 and then not Is_Immediately_Visible (Obj_Type)
7707 and then not In_Instance
7708 and then not Is_Private_Overriding (Prim_Op))
7713 Set_Etype (Call_Node, Any_Type);
7714 Set_Is_Overloaded (Call_Node, False);
7716 if No (Matching_Op) then
7717 Prim_Op_Ref := New_Reference_To (Prim_Op, Sloc (Subprog));
7718 Candidate := Prim_Op;
7720 Set_Parent (Call_Node, Parent (Node_To_Replace));
7722 Set_Name (Call_Node, Prim_Op_Ref);
7728 Report => Report_Error,
7730 Skip_First => True);
7732 Matching_Op := Valid_Candidate (Success, Call_Node, Prim_Op);
7734 -- More than one interpretation, collect for subsequent
7735 -- disambiguation. If this is a procedure call and there
7736 -- is another match, report ambiguity now.
7742 Report => Report_Error,
7744 Skip_First => True);
7746 if Present (Valid_Candidate (Success, Call_Node, Prim_Op))
7747 and then Nkind (Call_Node) /= N_Function_Call
7749 Error_Msg_NE ("ambiguous call to&", N, Prim_Op);
7750 Report_Ambiguity (Matching_Op);
7751 Report_Ambiguity (Prim_Op);
7761 if Present (Matching_Op) then
7762 Set_Etype (Call_Node, Etype (Matching_Op));
7765 return Present (Matching_Op);
7766 end Try_Primitive_Operation;
7768 -- Start of processing for Try_Object_Operation
7771 Analyze_Expression (Obj);
7773 -- Analyze the actuals if node is known to be a subprogram call
7775 if Is_Subprg_Call and then N = Name (Parent (N)) then
7776 Actual := First (Parameter_Associations (Parent (N)));
7777 while Present (Actual) loop
7778 Analyze_Expression (Actual);
7783 -- Build a subprogram call node, using a copy of Obj as its first
7784 -- actual. This is a placeholder, to be replaced by an explicit
7785 -- dereference when needed.
7787 Transform_Object_Operation
7788 (Call_Node => New_Call_Node,
7789 Node_To_Replace => Node_To_Replace);
7791 Set_Etype (New_Call_Node, Any_Type);
7792 Set_Etype (Subprog, Any_Type);
7793 Set_Parent (New_Call_Node, Parent (Node_To_Replace));
7795 if not Is_Overloaded (Obj) then
7796 Try_One_Prefix_Interpretation (Obj_Type);
7803 Get_First_Interp (Obj, I, It);
7804 while Present (It.Nam) loop
7805 Try_One_Prefix_Interpretation (It.Typ);
7806 Get_Next_Interp (I, It);
7811 if Etype (New_Call_Node) /= Any_Type then
7813 -- No need to complete the tree transformations if we are only
7814 -- searching for conflicting class-wide subprograms
7816 if CW_Test_Only then
7819 Complete_Object_Operation
7820 (Call_Node => New_Call_Node,
7821 Node_To_Replace => Node_To_Replace);
7825 elsif Present (Candidate) then
7827 -- The argument list is not type correct. Re-analyze with error
7828 -- reporting enabled, and use one of the possible candidates.
7829 -- In All_Errors_Mode, re-analyze all failed interpretations.
7831 if All_Errors_Mode then
7832 Report_Error := True;
7833 if Try_Primitive_Operation
7834 (Call_Node => New_Call_Node,
7835 Node_To_Replace => Node_To_Replace)
7838 Try_Class_Wide_Operation
7839 (Call_Node => New_Call_Node,
7840 Node_To_Replace => Node_To_Replace)
7847 (N => New_Call_Node,
7851 Skip_First => True);
7854 -- No need for further errors
7859 -- There was no candidate operation, so report it as an error
7860 -- in the caller: Analyze_Selected_Component.
7864 end Try_Object_Operation;
7870 procedure wpo (T : Entity_Id) is
7875 if not Is_Tagged_Type (T) then
7879 E := First_Elmt (Primitive_Operations (Base_Type (T)));
7880 while Present (E) loop
7882 Write_Int (Int (Op));
7883 Write_Str (" === ");
7884 Write_Name (Chars (Op));
7886 Write_Name (Chars (Scope (Op)));